agar and Neoplasms

Cytotoxic chemotherapy plays a key role in the treatment of carcinoma for thousands of patients annually who either present with metastatic disease or relapse after surgical excision of apparently localised disease. Unfortunately, there is such a wide range of responsiveness to drug therapy within individual tumour types that response of an individual patient's tumour to cytotoxic therapy cannot be accurately predicted. Intensive efforts to increase the accuracy of selection of effective chemotherapy have recently culminated in an in vitro system which employs soft agar and standard laboratory tissue culture techniques to predict drug sensitivity and resistance for an individual patient's tumour with reasonable accuracy. Research in this system is being actively pursued at several centres and further modifications and refinements may well make cancer chemotherapy more precise than previously possible. This review surveys methods of studying in vitro drug sensitivity which have been tested and for which clinical correlations are available. The technique and results of the more recently developed human tumour stem cell assay and the potential applications of this system are also discussed.

Topics: Agar; Antineoplastic Agents; Cells, Cultured; Colony-Forming Units Assay; Humans; Neoplasms; Nucleosides; Tumor Stem Cell Assay

Topics: Agar; Animals; Child; Culture Media; Culture Techniques; Hodgkin Disease; Humans; Inclusion Bodies, Viral; Leukemia; Lymphoma; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Non-Hodgkin; Male; Mice; Microscopy, Electron; Mycoplasma; Neoplasms; Neoplasms, Experimental; Rabbits; Rats

Maize (Zea mays) is an important staple food crop for the majority of Ghanaians. Maize is mostly contaminated by fungal species and particularly mycotoxins. This work aimed to identify and quantify the incidence of fungal infection and exposure to Ochratoxin A (OTA) as well as the health risk characterization in different age populations due to maize consumption in the Volta region. Maize samples were plated on Dichloran Rose Bengal Chloramphenicol (DRBC) agar, and Oxytetracycline Glucose Yeast Extract (OGYE) agar. All media were prepared in accordance with the manufacturers' instructions. The plates were incubated at 28 ± 2 °C for 5-7 days. High-Performance Liquid Chromatography connected to a fluorescence detector (HPLC-FLD) was used to analyze the ochratoxin A (OTA) levels in maize. Cancer risk assessments were also conducted using models prescribed by the Joint FAO/WHO Expert Committee on Additives (JECFA). The maize samples collected from the Volta region contained fungal population between the range of 3.08-4.58 log10 CFU/g. Eight (8) genera were recorded belonging to Aspergillus, Trichoderma, Penicillium, Fusarium, Saccharomyces, Mucor, Rhodotorula and Rhizopus. The species diversity includes A. flavus, A. niger, T. harzianum, P. verrucosum, F. oxysporum, Yeast, F. verticillioides, Rhodotorulla sp, A. fumigatus, R. stolonifer, M. racemosus species. Additionally, the ochratoxins level contained in the samples were very noteworthy and ranged from 1.22 to 28.17 μg/kg. Cancer risk assessments of OTA produced outcomes also ranged between 2.15 and 524.54 ng/kg bw/day, 0.03-8.31, 0.0323, and 0.07-16.94 for cases/100,000 person/yr for Estimated Daily Intake (EDI), Margin of Exposure (MOE), Average Potency, and Cancer Risks respectively for all age categories investigated. There was very high mycoflora load on the maize sampled from the Volta region, likewise the range of mycotoxins present in the maize grains, suggesting the potential to pose some adverse health effects with the populace of the Volta region.

Topics: Agar; Food Contamination; Ghana; Humans; Mycotoxins; Neoplasms; Ochratoxins; Zea mays

Scaffold-based culture is one of the effective methods to resemble three-dimensional (3D) cells model in vitro. An agar@lens paper hybrid scaffold was prepared by one-pot dip-coating. The lens paper's cellulose fiber networks are the scaffold's backbone. The agar gel seized the gaps between the fibrous structures that can improve the paper scaffold's optical transparency and prevent cells from spreading on the scaffold. The SEM and light microscope images showed that the agar gel on the bottom of the paper and the cellulose fiber of the paper formed micro-well structures. Without staining, the cells growing on the agar@paper scaffold can be directly observed under a light microscope. Cells aggregated between the cellulose fibers and formed spheroids within 24 h. The cell spheroids can be non-enzymatically retrieved from the agar@paper scaffold because of the cell-repelling property of agar. The agar@paper scaffold was applied for co-culturing tumor cells (MDA-MB-231, DU 145) and natural killer cells (NKs, NK-92). Using the agar@paper scaffolds, the tumor-infiltrating NKs can be separated from floating NKs that did not attack the tumor spheroids. The effect of NKs infiltrating on tumor spheroids size was characterized. The results showed that NKs attacking the spheroids grown on agar@paper scaffold can be readily tracked because of the improved optical transparency. Higher NKs: tumor cells ratio resulted in a high percentage of tumor infiltrating NKs. The separated NKs can be further tested to reveal their biological characteristics. Both agar and lens paper is accessible for most biological labs, highlighting the potential of agar@paper scaffold in 3D culture.

Topics: Agar; Cell Line; Humans; Killer Cells, Natural; Neoplasms; Spheroids, Cellular

Bloodstream infections have been the leading complications in cancer patients because they are at high risk for antibiotic-resistant bacterial infections. There is increasing evidence from different parts of the world of the high prevalence of antimicrobial-resistant bacterial strains in cancer patients. The burden of the infection is high in developing countries, especially in Ethiopia. Data on bacterial profile and antimicrobial susceptibility patterns among cancer patients in Ethiopia is limited. Thus, this study aimed to determine the predominant bacterial species causing bacteremia and their antibiotic resistance pattern among cancer patients at University of Gondar comprehensive specialized hospital.. A hospital-based, cross-sectional study was conducted on 200 study participants from March to July 2021. All cancer patients who developed a fever at the time of hospital visit were included in this study, and their socio-demographic and clinical data were collected using a structured questionnaire. Blood samples (10 mL for adults and 4 mL for children) were collected from each patient, and the collected blood samples were transferred into sterile tryptic soy broth, then incubated at 37°C for 7 days. Tryptic soy broth which showed signs of growth were Gram-stained and sub-cultured on blood agar, chocolate agar, MacConkey agar, and mannitol salt agar. The inoculated plates were then aerobically incubated at 37°C for 18-24 hours and the isolates obtained were identified using standard microbiological methods. Antimicrobial susceptibility tests were done using a modified Kirby-Bauer disk diffusion technique following CLSI 2021 guidelines. Data were entered using EPI data version 4.6 and analyzed with SPSS version 20.. In this study, out of 200 cancer patients included and 67.5% (135/200) of them were males. The majorities of study participants, 56% (113/200) of cancer patients were pediatrics and 26.5% (53/200) of them belong under five years of age. Out of 200 patient samples that had undergone culture, 27% (54/200) samples had bacterial growth. Gram-positive bacterial isolates were predominant, 61.1%, and S. aureus was the predominant Gram-positive isolate, (51.5.6%), followed by coagulase-negative staphylococci (48.5%). Moreover, K. pneumoniae (47%) and P. aeruginosa (29.5%) were the most common Gram-negative bacterial isolates. Among patients who had BSIs, the highest prevalence of BSIs was observed among males (66.7%), and in pediatrics cancer patients (44.2%). Pediatric study participants were more venerable to bloodstream infection (P = 0.000) compared to adult participants. Meropenem (100%), amikacin (100%), piperacillin/tazobactam (72.3%), and ceftazidime (73.5%) were effective against for Gram-negative isolates while cefoxitin (81.2%) and penicillin (70.5%) were effective for Gram-positive isolates. Additionally, most Gram-negative and Gram-positive bacterial isolates were sensitive for gentamycin (75.9%). Multidrug resistance was seen among 17.1% bacterial isolates, and MDR in Gram-negative and Gram-positive bacteria were 83.3% and 16.7%, respectively. Gram-negative bacterial isolates showed a high prevalence of MDR than Gram-positive isolates.. BSI's remains an important health problem in cancer patients, and Gram-positive bacteria were more common as etiologic agents of BSIs in cancer patients. S. aureus was the dominant bacteria followed by CoNS, K. pneumoniae, and P. aeruginosa. Multidrug-resistant isolates found in cancer patients and routine bacterial surveillance and study of their resistance patterns may guide successful antimicrobial therapy and improve the quality of care. Therefore, strict regulation of antibiotic stewardship and infection control programs should be considered in the study area.

Topics: Adult; Agar; Anti-Bacterial Agents; Bacteria; Child; Cross-Sectional Studies; Drug Resistance, Multiple, Bacterial; Ethiopia; Female; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Male; Microbial Sensitivity Tests; Neoplasms; Sepsis; Staphylococcus aureus

Tumor-treating Fields (TTFields) is a promising cancer therapy technique in clinical application. Computational simulation of TTFields has been used to predict the electric field (EF) distribution in the human body and to optimize the treatment parameters. However, there are only a few studies to validate the accuracy of the simulation model. Here we propose a measurement platform with technical details for validating the simulation model of TTFields. We further constructed homogeneous agar phantoms with different conductivity for voltage measurement. With the measured voltages from six equidistance recording points in the cylinder phantom, we calculated the EF intensity in the phantoms at different frequencies. Comparing the measured values with the simulated values obtained from two types of source simulation, we found that the current source simulation model of TTFields is a reliable method for evaluating the EF intensity distribution.

Topics: Agar; Computer Simulation; Electricity; Humans; Neoplasms; Phantoms, Imaging

Serine palmitoyltransferase (SPT) predominantly incorporates serine and fatty acyl-CoAs into diverse sphingolipids (SLs) that serve as structural components of membranes and signaling molecules within or amongst cells. However, SPT also uses alanine as a substrate in the contexts of low serine availability, alanine accumulation, or disease-causing mutations in hereditary sensory neuropathy type I, resulting in the synthesis and accumulation of 1-deoxysphingolipids (deoxySLs). These species promote cytotoxicity in neurons and impact diverse cellular phenotypes, including suppression of anchorage-independent cancer cell growth. While altered serine and alanine levels can promote 1-deoxySL synthesis, they impact numerous other metabolic pathways important for cancer cells. Here, we combined isotope tracing, quantitative metabolomics, and functional studies to better understand the mechanistic drivers of 1-deoxySL toxicity in cancer cells. We determined that both alanine treatment and SPTLC1

Topics: Agar; Alanine; Cell Membrane; Ceramides; Endocytosis; Metabolic Networks and Pathways; Neoplasms; Serine; Serine C-Palmitoyltransferase; Sphingolipids

Small molecule inhibitors of aurora kinases are currently being investigated in oncology clinical trials. The long-term effects of these inhibitors on proliferating euploid cells have not been adequately studied. We examined the effect of the reversible pan-aurora kinase inhibitor VX-680 on p53-competent human euploid cells. Circumscribed treatment with VX-680 blocked cytokinesis and arrested cells in G1 or a G1-like status. Approximately 70% of proliferatively arrested cells had 4N DNA content and abnormal nuclei. The remaining 30% of cells possessed 2N DNA content and normal nuclei. The proliferative arrest was not due to the activation of the tumor suppressor Rb and was instead associated with rapid induction of the p53-p21 pathway and p16. The induction was particularly evident in cells with nuclear abnormalities but was independent of activation of the DNA damage response. All of these effects were correlated with the potent inhibition of aurora kinase B. After release from VX-680, the cells with normal nuclei robustly resumed proliferation whereas the cells with abnormal nuclei underwent senescence. Irrespective of their nuclear morphology or DNA content, cells pre-treated with VX-680 failed to grow in soft agar or form tumors in mice. Our findings indicate that an intermittent treatment strategy might minimize the on-target side effects of Aurora Kinase B (AURKB) inhibitory therapies. The strategy allows a significant fraction of dividing normal cells to resume proliferation.

Topics: Agar; Animals; Apoptosis; Aurora Kinase B; Cell Line, Tumor; DNA; Humans; Mice; Neoplasms; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Tumor Suppressor Protein p53

In the present study, we have demonstrated synthesis of agar aldehyde (A

Topics: Agar; Aldehydes; Animals; Anti-Bacterial Agents; Antineoplastic Agents; Biopolymers; Cell Line, Tumor; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Metal Nanoparticles; Mice, Inbred BALB C; Nanocomposites; Neoplasms; Seaweed; Silver

Recent advances in biological imaging techniques and the enormous amount of data they generate call for the development of computational tools for efficient and reliable high-throughput analysis. Several software applications with this functionality are available, and one of the most commonly used is ImageJ. Here, we present two independent macros (WH_NJ and SA_NJ) for automating and facilitating the analysis of images acquired from two in vitro assays frequently used in cancer studies and drug screening: the wound-healing and soft-agar assays. These two algorithms combine, in a single command, the steps required for the individual analysis of each image using ImageJ. WH_NJ and SA_NJ allow fast, reproducible data analysis without the experimental bias inherent in manual analyses, thus guaranteeing the robustness and reliability of the results.

Topics: Agar; Algorithms; Cell Line, Tumor; High-Throughput Screening Assays; Humans; Image Processing, Computer-Assisted; Neoplasms; Software; Wound Healing

For the last five decades, measuring the ability of cells to grow in soft agar has served as the gold standard assay for in vitro cellular transformation. Nevertheless, the soft agar colony formation assay is time consuming and ill-suited for high-throughput screens. This unit describes an equally qualitative and quantitative assay known as growth in low attachment or GILA. The GILA assay is suitable for high-throughput pharmacological or genetic screens and allows the simultaneous examination of multiple cell lines and experimental perturbations. GILA conditions are specific and relevant to the transformed state because they depend on a property of cancer cells that is not shared by non-transformed cells. The GILA assay enables ex vivo drug sensitivity testing of patient-derived tumor cells to define precise treatments for individual patients. © 2016 by John Wiley & Sons, Inc.

Topics: Agar; Cell Adhesion; Cell Culture Techniques; Cell Separation; Cell Transformation, Neoplastic; Drug Screening Assays, Antitumor; Genetic Testing; High-Throughput Screening Assays; Humans; Neoplasms; Tumor Cells, Cultured

Absorption coefficient of biological tissue is an important factor for photothermal therapy and photoacoustic imaging. However, its determination remains a challenge. In this paper, we propose a method using focusing photoacoustic imaging technique to quantify the target optical absorption coefficient. It utilizes the ratio of the amplitude of the peak signal from the top boundary of the target to that from the bottom boundary based on wavelet transform. This method is self-calibrating. Factors, such as absolute optical fluence, ultrasound parameters, and Grüneisen parameter, can be canceled by dividing the amplitudes of the two peaks. To demonstrate this method, we quantified the optical absorption coefficient of a target with various concentrations of an absorbing dye. This method is particularly useful to provide accurate absorption coefficient for predicting the outcomes of photothermal interaction for cancer treatment with absorption enhancement.

Topics: Absorption; Acoustics; Agar; Algorithms; Calibration; Coloring Agents; Diagnostic Imaging; Equipment Design; Fourier Analysis; Humans; Lasers; Models, Statistical; Neoplasms; Optics and Photonics; Photoacoustic Techniques; Ultrasonics

In cryosurgery it is crucial that the performance of cryoprobes is predictable and constant. In this study we tested the intra- and interneedle variation between 17-gauge cryoprobes in two homogeneous mediums. Also, a multiprobe setup was tested. Cryoprobe performance was defined as the time it takes one cryoprobe to lower the temperature from 0 to -20 degrees C as measured by four thermosensors each at 3 mm distance from the cryoprobe. In agar eight cryoprobes were tested during six freeze cycles, and in gel four cryoprobes during four freeze cycles; each freeze cycle in a different cup of agar or gel. Using more accurate 'bare' thermosensors three cryoprobes were tested in gel during two freeze cycles. A multiprobe configuration with four cryoprobes was tested during two freeze cycles in both agar and gel. Statistical analyses were done using ANOVA for repeated measures. There was no significant intraneedle variation, whereas both in agar and gel there was a significant interneedle variation (p<0.05). Mean performance in gel was better than in agar (p<0.001). Also, there was a significant variation between the four thermosensors (p<0.001). Using bare thermosensors mean performance was 2.7 times faster compared to measurements by regular thermosensors (p<0.001). In a multiprobe configuration, overall performance seems less variable and more reproducible compared to a single cryoprobe. In conclusion, the performance of cryoprobes differs depending on the medium and measuring device used. Cryoprobes deliver reproducible freeze cycles, although there is variation between different cryoprobes. In a multiprobe configuration performance seems less variable.

Topics: Agar; Cryosurgery; Equipment Design; Gels; Hot Temperature; Humans; Models, Statistical; Neoplasms; Temperature; Time Factors

Ferrimagnetic materials can be expected to be useful as thermo seeds for hyperthermic treatment of cancer, especially where the cancer is located in deep parts of body, as they can generate heat by magnetic hysteretic loss when they are placed in an alternating magnetic field. Recently, it was reported that ferrimagnetic maghemite (gamma-Fe2O3) microspheres 20-30 microm in diameter prepared in aqueous solution can show excellent heat generating ability. However, these microspheres have many cracks on their surfaces. In this study, the preparation conditions for the microspheres was further optimized in order to obtain crack-free ferrimagnetic microspheres, and the in vitro heat generation of the obtained microspheres was measured in an agar phantom under an alternating magnetic field. Crack-free gamma-Fe2O3 microspheres 20-30 microm in diameter were obtained successfully. Their saturation magnetization and coercive force were 68 emu g(-1) and 198 Oe, respectively. Their heat generation under an alternating magnetic field of 300 Oe at 100 kHz was estimated to be 42 W g(-1). The microspheres showed in vitro heat generation when they were dispersed in an agar phantom and placed under an alternating magnetic field. It is believed that these microspheres may be useful for the in situ hyperthermic treatment of cancer.

Topics: Agar; Electromagnetic Fields; Equipment Design; Ferric Compounds; Hot Temperature; Humans; Hyperthermia, Induced; Magnetics; Materials Testing; Microspheres; Models, Statistical; Neoplasms; Phantoms, Imaging; Time Factors; Water

Bis-[(p-methoxybenzyl)cyclopentadienyl] titanium dichloride, better known as Titanocene Y, is a newly synthesized titanium-based anticancer drug. We studied the antitumor activity of Titanocene Y with concentrations of 2.1, 21 and 210 micromol/l against a range of freshly explanted human tumors, using an in-vitro soft agar cloning system. The sensitivity against Titanocene Y was highly remarkable in the case of renal cell, ovarian, nonsmall cell lung and colon cancer. In particular the surprisingly good response of nonsmall cell lung cancer and colon cancer against Titanocene Y at its lowest concentration of 2.1 micromol/l was well comparable or better with respect to cisplatin, given at a concentration of 1.0 micromol/l. Further clinical development of Titanocene Y appears to be warranted because of the broad cytotoxic activity shown and the specific activity of Titanocene Y against renal cell cancer.

Topics: Agar; Antineoplastic Agents; Cell Proliferation; Cell Survival; Culture Media; Humans; Neoplasms; Organometallic Compounds; Tumor Stem Cell Assay

Enzastaurin (LY317615.HCl) is an antiproliferative agent targeted specifically against PKC-beta. We have investigated the antitumoral effects of Enzastaurin against human cancer cell lines and freshly explanted human tumor tissue. Ten human cancer cell lines (NSCLC, colon, and thyroid) and human tumor specimens from 72 patients were used for in vitro studies in a cloning assay (HTCA). Cell lines and primary tumor cells were exposed to Enzastaurin for either 1 h or 7 days, or for 1 h or 21 days. At clinically achievable concentrations of Enzastaurin, inhibition of cell growth was observed for lung, colorectal, and thyroid cancer cell lines in a concentration dependent manner. Patient specimens exposed 1 h or 21 days to 1,400 nM Enzastaurin demonstrated inhibition rates of 24 and 32%, respectively. Marked inhibitory effects were observed in breast, thyroid, head/neck, non-small cell lung cancer, pancreatic cancer, and melanoma. In addition to its established antiangiogenic effects, Enzastaurin has direct antitumor activity against established human cancer cell lines and primary tumor specimens. This warrants further clinical development in tumors which have been identified to be potentially sensitive to Enzastaurin.

Topics: Agar; Antineoplastic Agents; Cell Line, Tumor; Cell Proliferation; Culture Media; Dose-Response Relationship, Drug; Humans; Indoles; Neoplasms; Neoplastic Stem Cells; Protein Kinase C; Protein Kinase C beta; Protein Kinase Inhibitors; Time Factors; Tumor Cells, Cultured; Tumor Stem Cell Assay

Recent evidence indicates that growth hormone-releasing hormone (GHRH) functions as an autocrine/paracrine growth factor for various human cancers. A splice variant (SV) of the full-length receptor for GHRH (GHRHR) is widely expressed in various primary human cancers and established cancer cell lines and appears to mediate the proliferative effects of GHRH. To investigate in greater detail the role of SV1 in tumorigenesis, we have expressed the full-length GHRHR and its SV1 in MCF-7 human breast cancer cells that do not possess either GHRHR or SV1. In accordance with previous findings, the expression of both GHRHR and SV1 restored the sensitivity to GHRH-induced stimulation of cell proliferation, with SV1 being more potent than the GHRHR. Furthermore, MCF-7 cells transfected with SV1 proliferated more quickly than the controls, even in the absence of exogenously added GHRH, suggesting the existence of intrinsic, ligand-independent activity of SV1 after its transfection. In agreement with the stimulation of cell proliferation, the levels of proliferation markers cyclin D1, cyclin E, and proliferating cell nuclear antigen were elevated in MCF-7 cells treated with GHRH, cultured in both serum-free and serum-containing media. In addition, SV1 caused a considerable stimulation of the ability of MCF-7 cells to grow in semisolid medium, an assay considered diagnostic for cell transformation. Collectively, our findings show that the expression of SV1 confers oncogenic activity and provide further evidence that GHRH operates as a growth factor in breast cancer and probably other cancers as well.

Topics: Agar; Alternative Splicing; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Neoplasms; Receptors, Neuropeptide; Receptors, Pituitary Hormone-Regulating Hormone; Transfection

Thioredoxin reductase 1 (TR1) is a major redox regulator in mammalian cells. As an important antioxidant selenoprotein, TR1 is thought to participate in cancer prevention, but is also known to be over-expressed in many cancer cells. Numerous cancer drugs inhibit TR1, and this protein has been proposed as a target for cancer therapy. We previously reported that reduction of TR1 levels in cancer cells reversed many malignant characteristics suggesting that deficiency in TR1 function is antitumorigenic. The molecular basis for TR1's role in cancer development, however, is not understood. Herein, we found that, among selenoproteins, TR1 is uniquely overexpressed in cancer cells and its knockdown in a mouse cancer cell line driven by oncogenic k-ras resulted in morphological changes characteristic of parental (normal) cells, without significant effect on cell growth under normal growth conditions. When grown in serum-deficient medium, TR1 deficient cancer cells lose self-sufficiency of growth, manifest a defective progression in their S phase and a decreased expression of DNA polymerase alpha, an enzyme important in DNA replication. These observations provide evidence that TR1 is critical for self-sufficiency in growth signals of malignant cells, that TR1 acts largely as a pro-cancer protein and it is indeed a primary target in cancer therapy.

Topics: Agar; Animals; Antioxidants; Cell Cycle; Cell Line, Tumor; DNA Replication; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Mice; Models, Biological; Neoplasms; NIH 3T3 Cells; Phenotype; Selenoproteins; Thioredoxin Reductase 1

More than 80 years ago Otto Warburg suggested that cancer might be caused by a decrease in mitochondrial energy metabolism paralleled by an increase in glycolytic flux. In later years, it was shown that cancer cells exhibit multiple alterations in mitochondrial content, structure, function, and activity. We have stably overexpressed the Friedreich ataxia-associated protein frataxin in several colon cancer cell lines. These cells have increased oxidative metabolism, as shown by concurrent increases in aconitase activity, mitochondrial membrane potential, cellular respiration, and ATP content. Consistent with Warburg's hypothesis, we found that frataxin-overexpressing cells also have decreased growth rates and increased population doubling times, show inhibited colony formation capacity in soft agar assays, and exhibit a reduced capacity for tumor formation when injected into nude mice. Furthermore, overexpression of frataxin leads to an increased phosphorylation of the tumor suppressor p38 mitogen-activated protein kinase, as well as decreased phosphorylation of extracellular signal-regulated kinase. Taken together, these results support the view that an increase in oxidative metabolism induced by mitochondrial frataxin may inhibit cancer growth in mammals.

Topics: Aconitate Hydratase; Adenosine Triphosphate; Agar; Animals; Cell Line, Tumor; Cell Proliferation; Cell Respiration; Colonic Neoplasms; Energy Metabolism; Frataxin; Gene Expression Regulation, Neoplastic; Humans; Intracellular Membranes; Iron-Binding Proteins; Mitochondria; Neoplasm Transplantation; Neoplasms; Oxygen; Oxygen Consumption; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Time Factors; Transfection

Hyperthermia has been used in multimodal cancer treatments, and in randomized, controlled studies, hyperthermia is an effective cancer therapy. For clinical accuracy and safety, however, temperature monitoring during treatment is essential. We aimed to develop a convenient microwave hyperthermia system combined with spatially resolved real-time temperature monitoring to improve its efficacy and safety.. Using an MR-compatible irradiation-type microwave applicator, agar phantoms, thigh muscles of rabbit, and subcutaneous VX2 tumors of rabbit were heated in combination with noninvasive MR temperature maps. For MR temperature calculation, a proton resonance frequency method was used. After determination of temperature coefficients and evaluation of the precision in MR thermometry, distribution of microwave heating over time was examined for each substance.. The temperature coefficients of phantoms, rabbit muscles, and VX2 tumors were -0.00977, -0.00976, and -0.01027 ppm/ degrees C, respectively. The 95% limits of agreement of MR and fluoroptic thermometry in the three subjects were +0.318/-0.339 degrees C, +0.693/-0.661 degrees C, and +0.564/-0.526 degrees C, respectively. Concerning VX2 tumor, the average tumor temperature was 42.60 +/- 0.14 degrees C and the surface of skin was 43.27 +/- 0.45 degrees C in the 60-min experimental period.. With this easy-to-use microwave hyperthermia system, effective hyperthermia was accomplished in phantoms and living animals in combination with MR temperature maps.

Topics: Agar; Animals; Disease Models, Animal; Hyperthermia, Induced; Magnetic Resonance Imaging; Male; Microwaves; Muscle, Skeletal; Neoplasm Transplantation; Neoplasms; Rabbits; Subcutaneous Tissue; Temperature; Thermography

To determine the effect of background tissue thermal conductivity on RF ablation heating using ex vivo agar phantoms and computer modelling.. Two-compartment cylindrical agar phantom models (5% agar, 5% NaCl, 3% sucrose) were constructed. These included a standardized inner compartment (2 cm diameter, 4 cm length, 0.25% agar) representing a tumour, surrounded by an outer compartment representing background tissue. The thermal conductivity of the outer compartment was varied from 0.48 W m-1 degrees Celsius (normal liver) to 0.23 W m-1 degrees Celsius (fat) by adding a fat-saturated oil-based solute (10-90%) to the agar. RF ablation was applied at 2000 mA current for 2 min. Temperatures were recorded up to 4 cm from the electrode tip at 1 cm intervals. Subsequently, a 2-D finite element computer model was used to simulate RF ablation of 2-24 min duration for tumours measuring 2-4 cm in diameter surrounded by tissues of different thermal conductivity with the presence or absence of perfusion (0-5 kg m-3 s-1) (n = 44). A comparison of results was performed.. In agar phantoms, the amount of fat in the background tissue correlated with thermal conductivity as a negative exponential function (r2 = 0.98). Significantly increased temperatures were observed at the edge of the inner compartment (1 cm from the electrode tip) as the fat content of the outer compartment increased (p < 0.01). Thus, temperatures at 2 min measured 31.5 +/- 2.2 degrees Celsius vs 45.1 +/- 3.1 degrees Celsius for thermal conductivities of 0.46 W m-1 degrees Celsius (10% fat) and 0.23 W m-1 degrees Celsius (90% fat), respectively. On the other hand, higher levels of fat led to lower temperature increases in the background compartment (0.2 +/- 0.3 degrees Celsius for 90% fat vs. 1.1 +/- 0.05 degrees Celsius for 10% fat, p < 0.05). Phantom thermal heating patterns correlated extremely well with computer modelling (r2 = 0.93), demonstrating that background tissues with low thermal conductivity increase heating within the central tumour, particularly for longer durations of RF ablation and in smaller tumours. Furthermore, computer modelling demonstrated that increases in temperature at the tumour margin for background tissues of lower thermal conductivity persisted in the presence of perfusion, with a clinically relevant 4.5 degrees Celsius difference between background thermal conductivities of fat and soft tissue for a 3 cm tumour with perfusion of 2 kg m-3 s-1, treated for 12 min.. Lower thermal conductivity of background tissues significantly increases temperatures within a defined ablation target. These findings provide insight into the 'oven effect' (i.e. increased heating efficacy for tumours surrounded by cirrhotic liver or fat) and highlight the importance of both the tumour and the surrounding tissue characteristics when contemplating RF ablation efficacy.

Topics: Agar; Catheter Ablation; Computer Simulation; Fever; Hot Temperature; Models, Theoretical; Neoplasms; Phantoms, Imaging; Temperature; Thermal Conductivity; Time Factors

Previous studies have established constitutive activation of Stat3 protein as one of the molecular changes required for tumorigenesis. To develop novel therapeutics for tumors harboring constitutively active Stat3, compounds from the NCI 2000 diversity set were evaluated for inhibition of Stat3 DNA-binding activity in vitro. Of these, a novel platinum (IV) compound, IS3 295, interacted with Stat3 and inhibited its binding to specific DNA-response elements. Further analysis suggested noncompetitive-type kinetics for the inhibition of Stat3 binding to DNA. In human and mouse tumor cell lines with constitutively active Stat3, IS3 295 selectively attenuated Stat3 signaling, thereby inducing cell growth arrest at G0/G1 phase and apoptosis. Moreover, in transformed cells, IS3 295 repressed expression of cyclin D1 and bcl-xL, two of the known Stat3-regulated genes that are overexpressed in malignant cells, suggesting that IS3 295 mediates anti-tumor cell activity in part by blocking Stat3-mediated sub-version of cell growth and apoptotic signals. Together, our findings provide evidence for the inhibition of Stat3 activity and biological functions by IS3 295 through interaction with Stat3 protein. This study represents a significant advance in small molecule-based approaches to target Stat3 and suggests potential new applications for platinum (IV) complexes as modulators of the Stat3 pathway for cancer therapy.

Topics: Agar; Animals; Apoptosis; Blotting, Western; Bromodeoxyuridine; Cell Cycle; Cell Line, Tumor; Cell Nucleus; Cell Proliferation; Cyclin D1; Cytosol; DNA; Fibroblasts; Flow Cytometry; G1 Phase; Gene Expression Regulation; Humans; Immunohistochemistry; In Situ Nick-End Labeling; Ki-67 Antigen; Kinetics; Luciferases; Mice; Neoplasms; NIH 3T3 Cells; Oligonucleotides; Oncogene Protein pp60(v-src); Piperazines; Plasmids; Platinum; Platinum Compounds; Protein Binding; Resting Phase, Cell Cycle; Signal Transduction; Time Factors

Factors influencing volumetric tumor measurement using 3-D ultrasound (US) were investigated. A 3-D US unit equipped with 4- to 8-MHz curved-array and 5- to 10-MHz linear-array mechanical volume transducers, and a US phantom made of 20 ham pieces (8.6 approximately 10.5 mL) embedded in agar gel that simulated hyperechoic tumors, were used. Volumetric tumor measurement was significantly affected by the position of US focus and tumor depth. When focus was at 2 cm and 8 cm below the transducer, 5-cm-deep tumors were measured 5.6% +/- 2.8% (mean +/- SD) and 8.3% +/- 2.2% bigger, respectively, than when focus was at 5 cm below the transducer, the same position as tumors (p < 0.01). Tumors were measured 11.8% +/- 2.9% bigger when they were 8-cm deep below the transducer than when they were 5-cm deep below the transducer (p < 0.001). Setting focus at the same position as tumors and keeping tumor depth consistent during serial 3-D US examinations may be necessary for reliable volumetric assessment of tumors.

Topics: Agar; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Neoplasms; Phantoms, Imaging; Reproducibility of Results; Ultrasonography

Hepatocellular carcinoma (HCC) is one of the most common malignancies in Southeast Asia. Although inactivation of pRb2/p130 has been reported in a variety of human cancers, its function in HCC has not been established. In this study we report that loss of expression of pRb2/p130 was detected by immunohistochemistry and western blotting in 15.2% (7 of 46) HCCs examined. High levels of pRb2/p130 expression were found in 84.8% (39 of 46) HCCs studied. Western blot analysis revealed that HCC had 3.5-fold higher pRb2/p130 than adjacent benign liver (ABL) tissues. 71.7% (33 of 46) of HCCs examined exhibited both nuclear and cytoplasmic staining for pRb2/p130. Cytoplasmic staining was found in 93.5% (43 of 46) of ABL tissues. Overproduction of pRb2/p130 in HepG2 cells led to growth suppression, cell cycle arrest in G0/G1, altered cell morphology, inhibition of in vitro colony formation and reduction in tumourigenicity in SCID mice. This demonstration suggests a role of pRb2/p130 as a tumour suppressor protein in HCC and the loss of this protein may lead to the development or progression of HCC. Overexpression of pRb2/p130 in HCC was, therefore, suggested to be a programmed protective response of the organism to uncontrolled proliferation.

Topics: Agar; Animals; Blotting, Western; Carcinoma, Hepatocellular; Cell Cycle; Cell Division; Cell Line; Cytoplasm; Disease Progression; DNA, Complementary; Electrophoresis, Agar Gel; Flow Cytometry; G1 Phase; Humans; Immunohistochemistry; Liver Neoplasms; Mice; Mice, SCID; Neoplasm Transplantation; Neoplasms; Precipitin Tests; Protein Biosynthesis; Proteins; Resting Phase, Cell Cycle; Retinoblastoma-Like Protein p130; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Transfection; Tumor Cells, Cultured

Conventional elastography involves quasistatic mechanical compression (external or internal) of the tissue under ultrasonic insonification to obtain radiofrequency (RF) A-lines before and after compression. Cross-correlation of the pre- and postcompression A-lines results in displacement images with axial gradients that produce the strain images (strain elastograms). Though the strain elastograms show structural similarities to the modulus images, they are not related in a simple way to the modulus images because the strains depend on both modulus and geometry of the materials being deformed. Therefore, a quantification of the similarities between the strain and modulus images may enhance the interpretation confidence of strain elastograms in depicting tissue structure. To demonstrate similarities between modulus images and strain elastograms, a feasibility study of using nanoindentation to obtain modulus images of thin slices of tissue and tissue-mimicking phantoms (agar-gelatin mixtures) was performed first, with encouraging results. This was followed by a comparison of modulus images and strain elastograms obtained from the same sample slices. The experimental results indicated that, under certain experimental conditions, it is feasible to perform quantitative comparisons between strain images (using elastography) and modulus images. A good visual, as well as quantitative, correspondence between structures in the modulus and strain images could be obtained at a 3-mm scale.

Topics: Agar; Connective Tissue; Elasticity; Feasibility Studies; Gelatin; Humans; Nanotechnology; Neoplasms; Phantoms, Imaging; Stress, Mechanical; Ultrasonography

Soft agar growth, used to measure cell anchorage-independent proliferation potential, is one of the most important and most commonly used assays to detect cell transformation. However, the traditional soft agar assay is time-consuming, labor-intensive, and plagued with inconsistencies due to individual subjectivity. It does not, therefore, meet the increasing demands of today's oncology drug target screening or validation processes. This report describes an alternative 96-well soft agar growth assay that can function as a replacement for the traditional method and overcomes the aforementioned limitations. It offers the following advantages: a shortened assay duration (1 week instead of 4 weeks) that makes transient transfection or treatment possible; plate reader quantification of soft agar growth (measuring cloning efficiency and colony size); and a significant reduction in required labor. Higher throughput also makes it possible to process large numbers of samples and treatments simultaneously and in a much more efficient manner, while saving precious workspace and overall cost.

Topics: Agar; Cell Count; Cell Culture Techniques; Cell Differentiation; Cell Division; Drug Delivery Systems; HeLa Cells; Humans; Neoplasms; Robotics

The tumor suppressor gene DICE1 is located within a previously reported critical region of loss of heterozygosity on chromosome 13q14.3. Expression of the remaining DICE1 allele is down-regulated in non-small cell lung carcinomas. Ectopic expression of DICE1 cDNA by DICE1-green fluorescent protein fusion constructs resulted in inhibition of colony formation of human non-small cell lung carcinoma cell line SK-MES-1 and NCI-H520 and prostate carcinoma cell line DU145. In IGF-IR transformed Balb/c 3T3, DICE1 substantially sup-pressed growth in soft agar. These results demonstrate that DICE1 has a growth-suppressing activity and interferes with anchorage-independent growth of IGF-IR transformed tumor cells dependent upon IGF-I signaling.

Topics: Agar; Amino Acid Motifs; Animals; Blotting, Northern; Cell Line, Tumor; Cell Proliferation; DNA, Complementary; Exons; Genes, Tumor Suppressor; Green Fluorescent Proteins; Humans; Insulin-Like Growth Factor I; Mice; Mice, Inbred BALB C; Neoplasms; Plasmids; Recombinant Fusion Proteins; Ribosomal Proteins; RNA; RNA Helicases; RNA-Binding Proteins; RNA, Messenger; Signal Transduction; Tumor Suppressor Proteins

Vascular endothelial growth factor (VEGF) is a major mitogen for endothelial cells and enhances vascular permeability. Enhanced VEGF secretion is found in human cancers and correlates with increased tumor neovascularization. ZD6474 is a p.o. bioavailable, VEGF flk-1/KDR receptor (VEGFR-2) tyrosine kinase inhibitor with antitumor activity in many human cancer xenografts and is currently in Phase I clinical development.. We tested the effects of ZD6474 on EGFR phosphorylation in cell expressing functional epidermal growth factor receptor (EGFR) and the antiproliferative and the proapoptotic activity of ZD6474 alone or in combination taxanes in human cancer cell lines with functional EGFR but lacking VEGFR-2. The antitumor activity of this drug was also tested in nude mice bearing established GEO colon cancer xenografts.. ZD6474 causes a dose-dependent inhibition of EGFR phosphorylation in mouse NIH-EGFR fibroblasts and human MCF-10A ras breast cancer cells, two cell lines that overexpress the human EGFR. ZD6474 treatment resulted in a dose-dependent inhibition of soft agar growth in seven human cell lines (breast, colon, gastric, and ovarian) with functional EGFR but lacking VEGFR-2. A dose-dependent supra-additive effect in growth inhibition and in apoptosis in vitro was observed by the combined treatment with ZD6474 and paclitaxel or docetaxel. ZD6474 treatment of nude mice bearing palpable GEO colon cancer xenografts (which are sensitive to inhibition of EGFR signaling) induced dose-dependent tumor growth inhibition. Immunohistochemical analysis revealed a significant dose-dependent reduction of neoangiogenesis. The antitumor activity of ZD6474 in GEO tumor xenografts was also found to be enhanced when combined with paclitaxel. Tumor regression was observed in all mice after treatment with ZD6474 plus paclitaxel, and it was accompanied by a significant potentiation in inhibition of angiogenesis. Six of 20 mice had no histological evidence of tumors after treatment with ZD6474 plus paclitaxel.. This study suggests that in addition to inhibiting endothelial cell proliferation by blocking VEGF-induced signaling, ZD6474 may also be able to inhibit cancer cell growth by blocking EGFR autocrine signaling. These results provide also a rationale for the clinical evaluation of ZD6474 combined with taxanes in cancer patients.

Topics: Agar; Animals; Antibodies, Monoclonal; Apoptosis; Blotting, Western; Cell Division; Cell Line, Tumor; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Enzyme Inhibitors; ErbB Receptors; Flow Cytometry; Humans; Immunohistochemistry; Mice; Mice, Inbred BALB C; Neoplasm Transplantation; Neoplasms; NIH 3T3 Cells; Paclitaxel; Phosphorylation; Piperidines; Protein-Tyrosine Kinases; Quinazolines; Receptors, Vascular Endothelial Growth Factor; Time Factors; Vascular Endothelial Growth Factor Receptor-2

Serum- and glucocorticoid-regulated kinase (SGK) is a serine kinase that has a catalytic domain homologous to that of Akt, but lacks the pleckstrin homology domain present in Akt. Akt reportedly plays a key role in various cellular actions, including glucose transport, glycogen synthesis, DNA synthesis, anti-apoptotic activity, and cell proliferation. In this study, we attempted to reveal the different roles of SGK and Akt by overexpressing active mutants of Akt and SGK. We found that adenovirus-mediated overexpression of myristoylated (myr-) forms of Akt resulted in high glucose transport activity in 3T3-L1 adipocytes, phosphorylated glycogen synthase kinase-3 (GSK3) and enhanced glycogen synthase activity in hepatocytes, and the promotion of DNA synthesis in interleukin-3-dependent 32D cells. In addition, stable transfection of myr-Akt in NIH3T3 cells induced an oncogenic transformation in soft agar assays. The active mutant of SGK (D-SGK, substitution of Ser422 with Asp) and myr-SGK were shown to phosphorylate GSK3 and to enhance glycogen synthase activity in hepatocytes in a manner very similar to that observed for myr-Akt. However, despite the comparable degree of GSK3 phosphorylation between myr-Akt and d-SGK or myr-SGK, d-SGK and myr-SGK failed to enhance glucose transport activity in 3T3-L1 cells, DNA synthesis in 32D cells, and oncogenic transformation in NIH3T3 cells. Therefore, the different roles of SGK and Akt cannot be attributed to ability or inability to translocate to the membrane thorough the pleckstrin homology domain, but rather must be attributable to differences in the relatively narrow substrate specificities of these kinases. In addition, our observations strongly suggest that phosphorylation of GSK3 is either not involved in or not sufficient for GLUT4 translocation, DNA synthesis, or oncogenic transformation. Thus, the identification of substrates selectively phosphorylated by Akt, but by not SGK, may provide clues to clarifying the pathway leading from Akt activation to these cellular activities.

Topics: 3T3 Cells; Adenoviridae; Adipocytes; Agar; Animals; Biological Transport; Blotting, Western; Catalytic Domain; Cell Division; Cell Line; Cell Transformation, Neoplastic; DNA; Fibroblasts; Gene Transfer Techniques; Glucose; Glucose Transporter Type 4; Glycogen Synthase; Hepatocytes; Immediate-Early Proteins; Immunoblotting; Interleukin-3; Mice; Monosaccharide Transport Proteins; Muscle Proteins; Mutation; Neoplasms; Nuclear Proteins; Phosphorylation; Precipitin Tests; Protein Serine-Threonine Kinases; Protein Structure, Tertiary; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Rats; Time Factors; Transfection

The effects of pretreatment growth conditions on the sensitivity of tumor cells to various cytotoxic agents were investigated using murine Ehrlich ascites tumor cells grown in two different environments. The tumor cells adapted to grow in the peritoneal cavity of mice were found to be more sensitive to ionizing radiation, oxygen toxicity, doxorubicin, and bleomycin than tumor cells adapted to grow in vitro. However, there was no difference in their sensitivity to 5-fluorouracil. One obvious difference between these two growth environments is oxygen tension; it is between 2.6 and 5.2% (20-40 mmHg) for the peritoneal cavity and 21% (159 mmHg) for the regular tissue culture. To investigate the role of oxygen tension, tumor cells from the peritoneal cavity were grown in tissue culture having either 21% O2 or 4% O2 in the gas phase. Within 4 d, tumor cells that were exposed to 21% O2, but not to 4% O2, in vitro gradually became as resistant to cytotoxic agents as the tumor cells continuously cultured in vitro under 21% O2. It appears that the adaptation of tumor cells to different environments having different partial pressure of oxygen alters their sensitivity not only to oxygen toxicity but also to other cytotoxic agents that damage or kill cells by generating free radicals.

Topics: Agar; Animals; Antibiotics, Antineoplastic; Antineoplastic Agents; Antioxidants; Bleomycin; Carcinoma, Ehrlich Tumor; Cell Division; Cell Survival; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Doxorubicin; Female; Fluorouracil; Free Radicals; Glutathione; Mice; Neoplasms; Oxygen; Radiation, Ionizing; Sensitivity and Specificity; Superoxide Dismutase; Time Factors

The susceptibility to levofloxacin of 194 consecutive staphylococcal (45 Staphylococcus aureus and 149 coagulase-negative staphylococci) isolates from neutropenic patients was determined by Etest and the results compared with those obtained using NCCLS-methods (broth microdilution, agar dilution and disk diffusion). Overall agreement at +/- 1log(2) dilution for Etest compared with broth microdilution and agar dilution was 99.0 and 83.5%, respectively. The Etest category agreement with broth microdilution and disk diffusion was 95.9 and 89.7%, respectively. Comparison of categories with Etest and agar dilution method gave only 67.0% absolute categorical agreement, with 29.9% minor errors and 10.7% major errors. No very major errors occurred by the four methods tested. Our results show that Etest is a valid alternative to the reference NCCLS-methods for monitoring the clinical usefulness of levofloxacin against staphylococci isolates from neutropenic patients.

Topics: Agar; Anti-Infective Agents; Culture Media; Diffusion; Drug Resistance, Microbial; Humans; Levofloxacin; Microbial Sensitivity Tests; Neoplasms; Neutropenia; Ofloxacin; Staphylococcus

An in vitro transformation system of carcinogen-treated Syrian hamster embryo (SHE) cell cultures represents multistep genetic and nongenetic changes that develop during the neoplastic progression of normal cells to tumor cells in vivo. During this neoplastic progression, SHE cells demonstrate an altered response to epidermal growth factor (EGF). In the present report, we examined the role of the adapter protein Gab1 (Grb2-associated binder-1) in the neoplastic progression of SHE cells. We used two asbestos-transformed SHE cell clones in different neoplastic stages: a 10W+8 clone, which is immortal and retains the ability to suppress the tumorigenicity of tumor cells in cell-cell hybrid experiments, and a 10W-1 clone, which has lost this tumor suppressor ability. 10W+8 cells expressed full-length 100-kDa Gab1 and associated 5.2-kb mRNA. Upon repeated cell passaging, 10W-1 cells showed increasing expression of a novel 87-kDa form of Gab1 as well as 4.6-kb mRNA with diminishing expression of the original 100-kDa Gab1. cDNA encoding the 87-kDa Gab1 predicts a form of Gab1 lacking the amino-terminal 103 amino acids (Gab1(Delta1-103)), which corresponds to loss of most of the pleckstrin homology (PH) domain. Gab1(Delta1-103) retains the ability to be phosphorylated in an EGF-dependent manner and to associate with the EGF receptor and SHP-2 upon EGF stimulation. The endogenous expression of Gab1(Delta1-103) in 10W-1 cells appeared closely related to EGF-dependent colony formation in soft agar. Moreover, transfection and expression of Gab1(Delta1-103), but not Gab1, in 10W+8 cells enhanced their EGF-dependent colony formation in soft agar. These results demonstrate that Gab1 is a target of carcinogen-induced transformation of SHE cells and that the expression of a Gab1 variant lacking most of the PH domain plays a specific role in the neoplastic progression of SHE cells.

Topics: Agar; Amino Acid Sequence; Animals; Asbestos; Base Sequence; Blood Proteins; Blotting, Northern; Blotting, Western; Carcinogens; Cell Division; Cell Line; Cells, Cultured; Cloning, Molecular; Cricetinae; Disease Progression; DNA, Complementary; Epidermal Growth Factor; Fluorescent Antibody Technique, Indirect; MAP Kinase Signaling System; Mesocricetus; Molecular Sequence Data; Neoplasms; Phenotype; Phosphoproteins; Phosphorylation; Plasmids; Precipitin Tests; Protein Structure, Tertiary; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Time Factors; Transfection; Transformation, Genetic

Differences of elasticity in tissue phantoms with inclusions of different elasticity were mapped by means of MR elastography (MRE). This new magnetic resonance imaging technique is based on the phase shift of the MR signal by switching a motion sensitizing magnetic field gradient simultaneously with the coupling of a shear wave. Wave patterns showing snapshots of the shear wave that propagates through the investigated substance were depicted in tomographic phase images. It was investigated wether a visualization of differences in elasticity of soft tissues was possible on the basis of differences in the wavelength. For this purpose, tissue phantoms with cylindrical inclusions were produced from agar gels, with agar concentrations between 1.0 and 1.5%. The diameters of the inclusions were of the order of a few centimetres. For diameters as small as 4 cm, there were still distinct differences in the wavelength between the matrix and the inclusion. The results of our study suggest that this technique has the potential for future application as an additional imaging method for tumor detection.

Topics: Agar; Elasticity; Gels; Humans; Magnetic Resonance Imaging; Neoplasms; Phantoms, Imaging; Stress, Mechanical

The specimen employed for the culture should be possibly rich of target cells in order to obtain the successful primary culture. When the target cells are located along the inner side of a duct forming tissue, they can be relatively easily isolated as major cell population in their whole dissegregated cells by means digesting the inner wall of ductive tissues. When the specimen supplied for the culture is so small and limited, the explant outgrowth culture method can be better applied for the culture. For the primary cultures of malignant cells, soft agar cell suspension method can be better available for the successful culture.

Topics: Agar; Cell Differentiation; Cell Separation; Cells, Cultured; Culture Media; Humans; Neoplasms; Specimen Handling

Radiation survival curves have been generated for 3 human tumor cell lines as a means of comparing and evaluating the validity of human tumor soft-agar clonogenic assays. The assays investigated were the Hamburger-Salmon, Courtenay-Mills, Courtenay-Mills plus additions, soft agar (no additions), and soft agar plus additions. The additions were formulated to supplement the media used in soft agar assays of primary ovarian and cervical carcinoma specimens. Supplementing the media with additions led to a 2- to 3-fold increase in PE of CaSki cells but had no effect on the PEs of ME180 and OWI cells. Radiation survival curves were similar in all assays for CaSki and OWI but differed for ME180 cells. For ME180 cells, the Courtenay-Mills and soft agar assays plus additions produced the most radioresistant curves (Do = 2.2 Gy); the cells were more responsive when assayed by the Hamburger-Salmon method (Do = 1.5 Gy), and the soft agar and Courtenay-Mills assays gave the most radiosensitive curves (Do = 1.2 Gy). These results demonstrate that the PE of human tumor cell lines may be increased with no effect on radiation survival; radiation survival may be altered without changes in PE and neither may be altered by applying modifications and supplements to existing clonogenic assays.

Topics: Adenocarcinoma; Agar; Carcinoma, Squamous Cell; Cell Line; Cell Survival; Colony-Forming Units Assay; Female; Humans; Neoplasms; Ovarian Neoplasms; Tumor Stem Cell Assay; Uterine Cervical Neoplasms

Cells from a cloned line of spontaneously transformed 3T3 cells had a colony-forming efficiency in agar (CFEag) of about 10-15% and induced poorly differentiated sarcomas when injected into nude mice. These tumor cells were recultured in vitro and tested for their ability to grow in suspension. Initially, the tumor cells had a CFEag which was a hundredfold to a thousandfold lower than the cells that had been grown only in vitro. After 5-8 further weekly passages, however, the tumor lines recovered their original ability to grow in agar. For determination as to whether this increased CFEag was due to selection of cells with a higher CFEag from the tumor cell population or to adaptation of many of the tumor cells to agar growth, clones were isolated directly from a primary tumor, and each was tested weekly for agar colony formation. All of the tumor clones, as well as the uncloned tumor line, were able to recover their original ability to grow in agar. However, one tumor clone had a relatively high CFEag in the first assay, so the selection hypothesis could not be totally excluded. The initial low CFEag of the recultured cells was not due to the presence of normal nude mouse cells in the population. Before in vivo growth no clones could be isolated from the sublines that had as low a CFEag as the tumor cells isolated after in vivo growth. Tumor cells that had been repeatedly passaged in vivo still had a much lower CFEag than the input cells upon explantation into culture. The results suggest that phenotypic alterations observed during tumor growth and subsequent cultivation have an epigenetic basis.

Topics: Agar; Animals; Animals, Suckling; Cell Division; Cell Survival; Cell Transformation, Neoplastic; Clone Cells; DNA; Histological Techniques; Mice; Mice, Nude; Neoplasm Transplantation; Neoplasms; Tumor Stem Cell Assay

Four families of human tumour cell lines--one of uterine, and three of ovarian origin--were established at early passage level from primary biopsy specimens of terminal patients by the propagation of anchorage-independent agar clones in liquid culture. All cell lines exhibited unique and stable characteristics and retained their ability to clone in agar. However, considerable heterogeneity was evident in clonogenic capacity, karyotype, and responsiveness to growth-promoting substances even among progeny of single agar clones isolated from the one biopsy specimen. These cell lines will be made available for further study upon request.

Topics: Agar; Aged; Biopsy; Carcinoma; Cell Line; Culture Media; Cystadenocarcinoma; Cytological Techniques; Female; Humans; Middle Aged; Neoplasms; Neoplasms, Experimental; Ovarian Neoplasms; Uterine Neoplasms

To investigate the influence of culture conditions on the in vitro responses of tumour cells to anticancer drugs, the sensitivities observed with the soft agar methods of Hamburger & Salmon (1977) (H-S) and of Courtenay & Mills (1978) (C-M) were compared. In all cases the ID50 values were determined from dose-response curves. Six human tumour cell lines exposed to 10 different agents, and 9 patients' melanomas exposed to 5 different agents, were examined. In the studies of cell lines the H-S method gave higher sensitivity values than the C-M method in 38 out of 52 cases, whereas in 14 cases the results were the same. In the patients' tumours the H-S method gave higher sensitivity in 21 of 35 cases, equal sensitivity in 11, and lower sensitivity in 3 cases. In many instances the ID50 values obtained with the two test systems differed by factors of 10 or more, both in the case of cell lines and tumour specimens. Systematic alterations in the culture conditions indicated that the presence or absence of rat erythrocytes is the most important factor responsible for the differences observed. Also, other factors, such as supplements (in the H-S method) and the use of different serum types, appeared to influence both colony growth and chemosensitivity.

Topics: Agar; Animals; Antineoplastic Agents; Breast Neoplasms; Cell Count; Cell Line; Cell Survival; Culture Media; Dose-Response Relationship, Drug; Erythrocytes; Humans; Melanoma; Neoplasms; Oxygen; Rats; Temperature

Topics: Agar; Cell Count; Cells, Cultured; Clone Cells; Humans; Kinetics; Leukocyte Count; Lymphocytes; Macrophages; Mitosis; Neoplasms

The in vitro clonogenicity of 25 human tumours was compared in two simple two layer culture systems, agar/agar and liquid medium/agar. There was a strong correlation between the values for clonogenicity obtained in each system. A linear relationship between cells plated and colonies formed was found in both systems. Radiation survival in the liquid culture system was essentially log linear with a small initial shoulder confirming that we were not simply counting clumps. We present a simple method of assessing the self-renewal capability of the clonogenic cells of human solid tumours, based on the liquid/agar two-layer system, which we have used to compare secondary plating efficiency and colony size analysis as measures of self renewal in human transitional cell carcinoma of the bladder.

Topics: Agar; Carcinoma, Transitional Cell; Cell Count; Cell Survival; Clone Cells; Colony-Forming Units Assay; Culture Media; Dose-Response Relationship, Radiation; Humans; Neoplasms; Tumor Stem Cell Assay; Urinary Bladder Neoplasms

Growth in soft-agar bilayer cultures of human tumour cells derived from 4 in vitro continuous cell lines, from 21 xenografts carried in athymic mice, and from 197 samples of fresh human solid tumours of various histologic types was analyzed by computer-assisted image analysis. Replicate cultures for each specimen were assessed on successive days of incubation for the number and volume of growth units within multiple size categories. Our results confirm the recent finding of others that there is an upper limit of approximately 10(9) microns 3 to the cumulative growth unit volume obtainable in a 2 ml bilayer soft agar culture system. Since this upper limit to the carrying capacity of the closed culture system exists, the extent of growth within the cultures is determined in a fundamental way by the cumulative volume of growth units initially inoculated into cultures. A growth index of greater than or equal to 16-fold was only seen when initial cumulative growth unit volume was less than 10(7) microns 3 per culture dish. Computer-assisted volume analysis (CAVA) appears to be a useful quantitative method to study the growth of human tumour cells in soft agar cultures.

Topics: Agar; Animals; Cell Count; Cell Line; Cell Survival; Cells, Cultured; Clone Cells; Computers; Culture Media; Humans; Methods; Mice; Neoplasm Transplantation; Neoplasms; Time Factors; Transplantation, Heterologous

Topics: Agar; Antineoplastic Agents; Cell Division; Cells, Cultured; Humans; Neoplasm Metastasis; Neoplasms; Prognosis

Two technological problems limit the usefulness of chemosensitivity assays: low success rates (generally 30-60%); and the requirement for large numbers of tumor cells (5 X 10(5)/dish). To solve these problems, we developed a miniaturized, improved, nucleic acid precursor incorporation assay (MINI-assay). In this new assay, 0.3-1.5 X 10(5) tumor cells were plated in double-layer agarose in 16-mm wells of a Costar (No. 3524) 24-well cluster dish. After 72 h of incubation, 5 microCi [3H]thymidine were added to each well. After an additional 24 h of incubation, the trichloroacetic acid-precipitable material was collected and counted by liquid scintillation. We found that 280 of 351 (80%) human solid tumors gave evaluable chemosensitivity results. Labeling efficiency was optimum when the plating density was between 1.5 and 3 X 10(4) cells/well. Radioisotope uptake was less efficient in 35-mm Petri dishes and in the 7-mm wells. The MINI-assay was particularly suitable for small specimens (less than 1 g) and for tumor types that usually yield small numbers of viable tumor cells (19 of 30 breast cancers and 56 of 71 sarcomas were evaluable). The artifacts of colony counting (cell clumps, debris, clots) were also eliminated with this assay. With high evaluability rates, the requirement of fewer cells, a short duration (5 days), and ease of quantitation, the MINI-assay is widely applicable to chemosensitivity testing in human tumors.

Topics: Agar; Cell Count; Colony-Forming Units Assay; Culture Media; Humans; Neoplasms; Sepharose; Thymidine; Tumor Stem Cell Assay

To examine whether selection of tumour cell subpopulations occurs during cultivation in soft agar, we compared in 23 human tumours of different histological types the DNA content of cells from colonies formed in soft agar (method of Courtenay and Mills, 1978) with that of the original tumour cells. The ploidy as well as the fraction of cells in S phase were determined from DNA histograms after staining of the nuclei with a propidium-iodide procedure and flow cytometric recordings. In 8 of 17 aneuploid tumours analysed, specific aneuploid subpopulations disappeared during cultivation or new aneuploid populations, not demonstrable in the original cell suspensions, appeared in the colonies. In 9 cases identical aneuploid populations were found in the colonies and the tumours. In one of 6 diploid tumours examined, aneuploid cell populations not revealed in the original cell suspension, were found in addition to diploid cells, whereas 5 tumours gave rise to colonies containing a purely diploid population. The results show that in a variety of human malignant tumours cultivation in soft agar may select specific aneuploid tumour cell populations.

Topics: Agar; Cell Division; Cells, Cultured; DNA, Neoplasm; Female; Flow Cytometry; Humans; Interphase; Neoplasms; Ploidies

Topics: Agar; Animals; Biopsy; Breast Neoplasms; Cell Survival; Colonic Neoplasms; Colony-Forming Units Assay; Culture Techniques; Female; Humans; Male; Melanoma; Melphalan; Mice; Neoplasms; Ovarian Neoplasms; Rectal Neoplasms; Tumor Stem Cell Assay

Topics: Agar; Antineoplastic Agents; Cell Survival; Clone Cells; Colony-Forming Units Assay; Culture Techniques; Drug Evaluation, Preclinical; Evaluation Studies as Topic; Female; Humans; Neoplasms; Tumor Stem Cell Assay

If soft agar colony formation assays for primary human tumor cells are going to be performed and the results assessed by optical analysis of colony formation, then we believe it is mandatory in such assay techniques to objectively count control plates on the day of culture initiation using stained plates, use universal cytotoxic control compounds which should uniformly eliminate all viable cell proliferation, and use a vital stain such as the tetrazolium dye INT to document the presence or absence of viable cell colonies when cultures are assessed. There is no question, however, after careful observation of thousands of soft agar cultures of primary human tumor cells in my laboratory, that significant proliferation of small tumor cell aggregates often takes place in vitro and can in fact be used to assess cytotoxic drug effects in vitro. We do not believe that this is demonstrably stem cell or clonal growth. Nevertheless, it almost certainly is in vitro tumor cell proliferation. With very careful controls, we believe that optical methods can be used reliably to evaluate drug effects on this soft agar proliferative capacity of primary human tumor cells. However, it may eventually prove more useful to study human tumor cell proliferation in vitro (even soft agar colony growth) by other methods, such as incorporation of radiolabeled bases into newly synthesized DNA or other macromolecules, or by the simple use of vital dyes, as discussed elsewhere in this volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Agar; Antineoplastic Agents; Colony-Forming Units Assay; Drug Evaluation, Preclinical; Evaluation Studies as Topic; Humans; Neoplasms; Tumor Stem Cell Assay

Topics: Agar; Biopsy; Breast Neoplasms; Cell Survival; Clone Cells; Culture Techniques; Female; Humans; Lung Neoplasms; Male; Melanoma; Methylcellulose; Microscopy, Electron; Neoplasms; Pleural Effusion

To improve clinical interpretation and use of in vitro clonogenic assay results, the authors reviewed their experience to date with chemosensitivity testing of over 1500 solid tumors. All clonogenic assays were performed using a double-layer-soft-agar system with continuous exposure of cells to one concentration of standard anticancer drugs. Significant growth was defined as greater than or equal to 30 colonies/control plate. Clinical responses were determined according to standard criteria. Data were analyzed using two different criteria of in vitro sensitivity (greater than or equal to 50% and greater than or equal to 75% inhibition of colony formation) and independently for each histologic type of tumor. Overall, 68% of specimens plated produced significant growth in vitro. Cloning ability varied from 57% to 82% depending on tumor histology. The assay was 57% reliable for predicting in vivo sensitivity, and 92% reliable for in vivo resistance. Predictive accuracy for sensitivity varied from 30% to 86%, depending on the tumor histology. Use of greater than or equal to 50% ICF (inhibition of colony formation) as criteria for differentiating sensitivity from resistance proved most reliable, although criteria should be individualized for each tumor type to maximize predictive accuracy.

Topics: Agar; Antineoplastic Agents; Clone Cells; Drug Evaluation; Drug Resistance; Humans; In Vitro Techniques; Neoplasms; Prospective Studies

We have compared plating efficiencies (PE) of 20 fresh and cryopreserved samples of human solid tumors, disaggregated and cloned simultaneously in a two-layer agar culture system (2LACS) and in agar diffusion chambers (ADC). A significant correlation (0.001 less than P less than 0.01, paired t test) was found between PE, confirming that the two methods reflect the same property of tumor cells: their clonogenic potential. The median PE in ADC was 1.4 and 3.3 times higher than that in the 2LACS for cryopreserved and fresh specimens, respectively. One- and two-drug doses, approximately clinically achievable concentrations, were assayed simultaneously in the ADC and in the 2LACS, respectively, on 15 tumor specimens. In this way we evaluated the effects of eight drugs, two to five for each tumor, in a static (2LACS) versus a dynamic (ADC) system. The comparison of percent survival in ADC versus that in the 2LACS at both concentrations tested showed no statistically significant rank correlation. If the data regarding cyclophosphamide and mitomycin, which produced significant cell kill in the ADC and almost none in the 2LACS, were excluded, the rank correlation was still not significant. We conclude that the widely used 2LACS is unsuitable to study cyclophosphamide and mitomycin, for which the ADC technique may be a valid alternative.

Topics: Agar; Animals; Antineoplastic Agents; Cell Division; Cell Survival; Clone Cells; Colony-Forming Units Assay; Drug Evaluation, Preclinical; Humans; Mice; Neoplasms; Tissue Preservation; Tumor Stem Cell Assay

Somatic cell hybrids were generated between Chinese hamster cell lines (Cl-4 and TK 17-O) with a near-diploid number of partially abnormal chromosomes and embryonic mouse fibroblasts (BALB/c). Hybrids harboring a near-diploid, near-triploid, and near-tetraploid set of hamster chromosomes plus 22 to 30 mouse chromosomes were analyzed for the expression of the transformed or tumorigenic phenotype, respectively, indicated by their capacity to form colonies in soft agar and by tumor formation after s.c. injection into nude mice. The hybrids showed (partial) suppression of tumorigenicity and of anchorage independence. The minimum number of hybrid cells required to initiate tumor growth in nude mice was 100- to 50,000-fold higher, and the latency period was 3- to 6-fold longer in comparison with the highly tumorigenic parental hamster cells. Suppression of tumorigenicity was also found in intraspecific Chinese hamster hybrids involving tumorigenic cells (E 36-O and TK 17-O) and embryonic hamster fibroblasts. To identify those mouse chromosomes associated with suppression of tumorigenicity, we investigated the expression of mouse isozyme genes and the presence of mouse chromosomes in interspecific suppressed hybrids and their tumorigenic hybrids described previously. No single mouse chromosome, even if present in two copies, and no combination of two different mouse chromosomes was sufficient to suppress tumorigenicity in these hybrids. This conclusion is based on either the presence of these chromosomes in hybrids isolated from tumors or their absence in suppressed hybrids.

Topics: Agar; Animals; Cell Division; Cell Line; Chromosome Aberrations; Chromosomes; Cricetinae; Cricetulus; Embryo, Mammalian; Fibroblasts; Genotype; Hybrid Cells; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasms

Purified human leukocyte interferon produced by recombinant techniques (IFN-alpha A) was tested in vitro with chemotherapeutic drugs, vinblastine (VLB), vincristine (VCR), vindesine (VDS), vinzolidine (VZL), cis-platinum (PLAT), doxorubicin (DOXO), etoposide (VP-16), and melphalan (MEL). The activity of these agents alone or in combination was tested against various human tumor cell lines, using a modified soft agar clonogenic assay. Three human tumor cell lines (myeloma, RPMI 8226; breast, MCF-7; and colon, WiDR) showed sensitivity to these agents at clinically achievable drug concentrations. Statistically significant synergistic activity against in vitro colony formation was observed with the combination of VLB and IFN-alpha A. An additive or sub-additive effect was usually observed with the other agents tested. Continuous exposure of the 8226 myeloma cell line to both IFN-alpha A and PLAT showed evidence of a more significant potentiation. It is hypothesized that the synergistic effect observed between VLB and IFN-alpha A is due to some of their common mechanisms of action.

Topics: Agar; Antineoplastic Agents; Cell Line; Clone Cells; Dose-Response Relationship, Drug; Drug Synergism; Humans; Interferon Type I; Neoplasms; Vinca Alkaloids

Treatment of a variety of human tumor cells in monolayer cultures with low levels (40 to 80 microM) of adenosine 5'-diphosphate (ADP) or adenosine 5'-triphosphate (ATP) was recently shown to produce arrest of cellular growth in the S phase of the cell cycle (E. Rapaport, J. Cell. Physiol., 114: 279-283, 1983). We now demonstrate that exposure of two well-characterized colonic adenocarcinoma (HT-29 and SW-620) and two pancreatic adenocarcinoma (CAPAN-1 and PANC-1) cell lines in soft-agar cultures to exogenously supplied 5 to 20 microM ATP results in substantial inhibition of cellular growth. Exposure of the cells to 5 to 20 microM ADP produces slightly smaller growth-inhibitory effects, while 20 microM adenosine 5'-monophosphate or adenosine have marginal effects on cellular proliferation in these systems. Successful demonstration of these effects requires the use of heat-inactivated fetal bovine serum, since normal fetal bovine serum possesses enzymatic activities which catalyze the rapid degradation of adenine nucleotides. Tumor cell growth was assayed by the well-established colony formation assay as well as by [3H]thymidine incorporation into acid-insoluble material. [3H]Thymidine incorporation is performed 4 to 14 days after plating and correlates well with results obtained by colony formation assays. Due to the ectoenzymatic activities of the cells which include adenosinetriphosphatase and adenosinediphosphatase catalyzing the dephosphorylation of ATP and ADP, the effective levels of ATP that inhibit the growth of human tumor cells in this system, which is widely claimed to predict the in vivo response of a tumor, are lower than the 5 to 20 microM which are exogenously supplied. The two previously characterized, well-differentiated pancreatic and colonic tumor cell lines (CAPAN-1 and HT-29) were shown to exhibit higher chemosensitivity towards treatment with ATP and ADP than did the lesser-differentiated pancreatic and colonic tumor cell lines (PANC-1 and SW-620).

Topics: Adenosine; Adenosine Diphosphate; Adenosine Monophosphate; Adenosine Triphosphate; Agar; Cell Division; Cell Line; Cell Survival; Culture Media; DNA Replication; Humans; Neoplasms

Human tumor cell lines, derived from cancers of the colon, ovary, and cervix, were grown in liquid tissue culture media and media made semisolid with agar (Bacto + deoxycholate lactose agar), agarose [LE, ME, Sea Plaque and Sea Prep (15/45)], and methyl cellulose. The effects of each agent on overall cell proliferation and rate of overall cell proliferation were examined. The agents, used to make media semisolid, were observed to inhibit or, in some cases, enhance cell growth in a fashion that was characteristic of individual cell lines. These phenomena may be of consequence to the optimization of nutrient media for primary tumor cell preparations.

Topics: Agar; Cell Division; Cells, Cultured; Culture Media; Humans; Methylcellulose; Neoplasms; Sepharose

Cloning efficiencies of 67 fresh human tumor specimens, consisting of 29 ovarian, 10 lung, and 7 each of colon, breast, mesenchymal, and miscellaneous tumors, from 58 patients were studied using the technique of Hamburger and Salmon to evaluate the effect of incubation in a 5% rather than 20% oxygen environment. Under the low-oxygen tension, carcinomas exhibited an average of 170% increase in cloning efficiency (p less than 0.01). The number of carcinomas forming at least 30 colonies/dish increased from 22 to 27. Mesenchymal tumors, however, exhibited a 20% decrease in cloning efficiency (not significant). A mixture of 5% oxygen, 5% carbon dioxide, and 90% nitrogen gives a higher cloning efficiency than 20% oxygen, 5% carbon dioxide, and 75% nitrogen for certain human carcinomas in semisolid agar.

Topics: Agar; Cell Division; Cells, Cultured; Culture Media; Humans; Neoplasms; Oxygen; Partial Pressure

Over the past year, we have attempted to grow both primary and metastatic urologic malignancies using a recently developed human tumor cloning system. Formation of colonies in vitro occurred in 125 of 164 primary tumors (76%), including 34 of 47 uroepithelial cancer specimens, 45 of 50 renal cell cancer specimens, 24 of 33 prostatic cancer specimens, and 22 of 34 testicular cancer specimens. A large percentage of metastatic cancers have also been successfully cultured. Growth sufficient for chemosensitivity testing ranged from 43% of the uroepithelial cancers cultured to 64% of the renal cell cancer specimens cultured. When in vitro chemosensitivity testing was performed, the in vitro chemosensitivity results show a striking similarity to clinical response rates for the same agents used for these tumors. Overall the human tumor cloning system appears to be a reasonable model for the study of human urologic malignancies.

Topics: Acid Phosphatase; Agar; alpha-Fetoproteins; Antineoplastic Agents; Cell Count; Chorionic Gonadotropin; Chorionic Gonadotropin, beta Subunit, Human; Clone Cells; Cytological Techniques; Drug Resistance; Genital Neoplasms, Male; Humans; Male; Microscopy, Electron; Neoplasm Metastasis; Neoplasms; Peptide Fragments; Urologic Neoplasms

Cell suspensions were prepared by either mechanical or enzymatic disaggregation methods from biopsy specimens from 54 patients with various tumors. The biologic activities of cells derived from the two suspensions were then examined. Biopsy specimens of solid tumors were minced, and one-half of each specimen was further processed by being teased with needles, whereas the other half was exposed to a combination of collagenase, hyaluronidase, and DNase. The enzymatic disaggregation method yielded fewer cells per gram of tissue than the mechanical method. However, the percentage of dye-excluding cells was increased by the enzymatic procedure in 93% of the cases. Cells obtained by enzymatic means also had higher cloning efficiencies than those obtained by mincing. The histologic types of cells present in the initial cell suspensions were the same for cells obtained by the enzymatic or mechanical disaggregation methods. The number of colonies obtained was linearly related to the number of cells plated in both cases. The tritiated thymidine suicide indices (estimates of the percentage of cells in the S-phase of the cell cycle) were the same for the two cell populations obtained by the two methods. The results indicate that cells obtained from solid tumors by enzymatic dissociation methods did not differ significantly from cells obtained by the more conventional mechanical techniques. However, cell viabilities and cloning efficiencies were significantly improved by the enzymatic technique.

Topics: Agar; Cell Division; Cell Separation; Cell Survival; Cells, Cultured; Clone Cells; Deoxyribonucleases; Humans; Hyaluronoglucosaminidase; Microbial Collagenase; Neoplasms

We evaluated colony formation in soft agar by cells obtained after mechanical and/or enzymatic disaggregation of 455 malignant human tumours. Counting and assessment of cell colonies in the agar plates were done by inverted microscopy, computerized image analysis, and inspection of serial photomicrographs of the agar plates. Our results indicate that standard methods of tumour disaggregation did not usually produce single-cell suspensions and that aggregates of tumour cells varying greatly in size were placed in the agar. Most groupings of cells identified as colonies 1-3 weeks after plating arose from enlargement of preexisting aggregates of cells.

Topics: Agar; Cell Aggregation; Cell Count; Cells, Cultured; Deoxyribonucleases; Humans; Microbial Collagenase; Neoplasms; Time Factors

Topics: Agar; Cells, Cultured; Cytological Techniques; False Positive Reactions; Humans; Neoplasms

Topics: Agar; Antineoplastic Agents; Cell Division; Cell Line; Cells, Cultured; Colonic Neoplasms; DNA Replication; Drug Evaluation, Preclinical; Female; Humans; Kinetics; Melanoma; Neoplasm Metastasis; Neoplasms

Topics: Agar; Antineoplastic Agents; Culture Techniques; Drug Evaluation, Preclinical; Drug Resistance; Humans; Neoplasms

Two simple techniques are described for preparing sections from soft agar colony cultures of tumor cells. Tumor cells grown in soft agar can be frozen, sectioned, and stained and/or fixed in formalin, embedded in paraffin, sectioned, mounted on glass slides, and stained. The methods are simple and reproducible. These cells can be stained with various stains and the staining quality is excellent. The paraffin blocks and microscope slides can be stored for permanent record. The use of these techniques should provide better understanding of the histomorphologic characteristics of neoplastic cells which grow in soft agar and should expand and refine prognosis and diagnosis of malignant tumors.

Topics: Agar; Frozen Sections; Histological Techniques; Humans; Neoplasms; Staining and Labeling

Tumor-bearing lymph nodes from SJL mice were characterized by histologic, ultrastructural, and immunologic methods. These approaches consistently revealed a predominance of macrophage-like cells in the primary neoplasm. When the tumor-bearing lymph nodes were placed in cell culture, colonies of adherent cells grew slowly to confluence and demonstrated morphologic and functional properties of macrophages. The tumor cells were also grown in soft agar where clusters and colonies of large, often binucleate, cells predominated. These cells were uniformly nonspecific esterase-positive, again, suggesting a macrophage origin. In addition, supernatants derived from SJL tumor cells were shown to have mitogen-augmenting activity as tested on murine thymocytes. These findings are discussed in the context of the SJL tumor as a proliferative condition primarily involving macrophages, which may be useful as a model of human diseases such as Hodgkin's disease.

Topics: Agar; Animals; Culture Techniques; Female; Interleukin-1; Interleukin-2; Lymph Nodes; Lymphatic Diseases; Lymphoma, Large B-Cell, Diffuse; Macrophages; Mice; Mitogens; Neoplasms; Proteins

The effect of epidermal growth factor (EGF) and fibroblast feeder layers on the proliferation of human tumor cells in soft agar was examined. The addition of EGF to medium supporting growth of tumor cells significantly increased (P less than or equal to 0.02) the number of colonies grown from the cells of 36 to 58 patients (62%) with a variety of neoplasms. The increase in the number of colonies was dependent on the concentration of EGF and was maximal at a concentration of 50 ng EGF/ml. The addition of glucocorticoids did not potentiate the effect of EGF. Lethally irradiated fibroblast feeder layers alone only slightly increased the number of colonies. However, the addition of fibroblasts to cultures significantly increased the mitogenic effect of EGF. The results suggest that a proportion of epithelial-derived tumors retain responsiveness in vitro to physiologic growth regulators such as EGF.

Topics: Agar; Cell Division; Cells, Cultured; Culture Media; Epidermal Growth Factor; Epithelium; Fibroblasts; Glucocorticoids; Humans; Neoplasms

Amethopterin synchronization of bone marrow and lymph node cells makes it possible to obtain well banded and elongated metaphases and prometaphases in the majority of patients with leukemia and lymphoma. Chromosomal analysis of most neoplasias is also possible through the use of mild tumor cell disaggregation methods, short term culture on feeder layers, and special media that help in the preferential proliferation of cancer cells. In the past, only about half of all patients with acute leukemia and lymphoma could be shown to have a chromosomal defect, and only a small proportion of solid tumors could be analyzed. With the new technology, abnormal tissue from the majority of cancer patients can be successfully studied and chromosomal abnormalities detected.

Topics: Adolescent; Adult; Agar; Bone Marrow; Bone Marrow Cells; Cell Line; Chromosome Aberrations; Chromosome Banding; Female; Humans; Leukemia; Lymph Nodes; Lymphocytes; Male; Metaphase; Methotrexate; Neoplasms; Tissue Extracts

Hamburger and Salmon have recently developed an in vitro assay for human tumor stem cells which permits formation of colonies of human solid tumors and lymphomas in soft agar. In 50 patients with solid tumors or lymphomas studied by us, tumor colonies grew from effusions and biopsies in 75% of patients (17 of 21) with histologically or cytologically involved specimens. Lymphoid colony growth was obtained in about 25% of specimens (5 of 19) including malignant lymphomas. Conversely, no colony growth was observed in 10 cases where the biopsies or effusions were histologically or cytologically negative. The effect of various conditioned media on tumor growth in agar was investigated. Colony formation of solid tumors was promoted to an especially marked extent by cell-free malignant effusions. This assay yields satisfactory results in solid tumors and appears useful for investigation of different cytotoxic effects of anticancer drugs on the survival of human tumor colony-forming cells.

Topics: Agar; Antineoplastic Agents; Cells, Cultured; Culture Media; Drug Resistance; Humans; Methods; Neoplasms

Tumor cells from five human neoplastic effusions were successfully cloned in soft agar and their sensitivity to anticancer drugs was tested. Three patients were resistant in vitro and were found to be resistant in vivo to the same drugs. Two patients were sensitive in vitro and were found to be sensitive in vivo to the same drugs.

Topics: Agar; Antineoplastic Agents; Cell Survival; Cells, Cultured; Clone Cells; Drug Evaluation, Preclinical; Female; Humans; Male; Neoplasms

Topics: Agar; Cells, Cultured; Clone Cells; Humans; Karyotyping; Neoplasms; Nucleolus Organizer Region; Staining and Labeling

Three in vivo assays of excised tumours are compared, the endpoint dilution assay, the tumour latency assay and the lung colony assay. The assay procedures are discussed in 2 phases; the preparation of the required cell suspension and the injection and growth of the tumour cells in recipients. Factors reviewed include those affecting recovery of cells during the suspension procedure, the variability of tumour response, the importance of the site of injection, the effect of heavily irradiated cells and non-lethal effects of radiation. Specific aspects of the lung colony assays are also described. Results of an experiment to compare the 3 assay procedures with that of an in vitro agar colony assay are presented and indicate reasonable agreement for the KHT sarcoma except perhaps for the latency assay at low levels of survival. A list of recommendations of ways to minimize some of the potential problems and a comparison of assay procedures is presented.

Topics: Agar; Animals; Cell Survival; Clone Cells; Dose-Response Relationship, Radiation; Injections; Lung; Methods; Mice; Neoplasm Transplantation; Neoplasms; Sarcoma, Experimental; Time Factors; Transplantation, Homologous

Cytogenetic analysis of human tumors is rapidly coming of age as a useful tool in the diagnosis and prognosis of cancer. With the use of chromosome-banding analysis, an increasing display of tumors containing cytologically recognizable nonrandom chromosome change is accumulating. Additionally, with avenues of assessing drug resistance and sensitivity, current cytogenetic analyses are yielding clinically relevant information. Finally, the blending of cytogenetics with biochemistry and cell biology is yielding an impressive array of research tools for the subcellular study of cancer. DNA hybridization, gene cloning, autoradiography of various drug and hormonal chromosomal binding sites, gene mapping, and numerous other related techniques are providing fresh insights into the genetic basis of cancer. It seems clear that during the next decade substantial progress in understanding chromosome structure and function in normal cells as well as tumor cells will occur. Technical advances in the methodology for growing and harvesting tumor cells for detailed cytogenetic analysis will undoubtedly be important in this effort. Application of the described soft agar colony technique may provide a useful tool for study of the genetics of human solid tumors.

Topics: Agar; Chromosome Aberrations; Chromosome Disorders; Chromosomes, Human, 1-3; Clone Cells; Culture Media; Female; Humans; Karyotyping; Mitosis; Neoplasms; Ovarian Neoplasms; Urinary Bladder Neoplasms

The application of the tumor stem cell assay to the study of human tumor cell kinetics has the potential for major advances in our knowledge of proliferative characteristics of clonogenic human tumor cells. From simultaneous evaluation of in vitro drug sensitivity, in vitro doubling time, and the thymidine suicide index, plus flow cytometry, cytogenetic analysis, and assessment of differentiation markers, substantial insights into the basic biology of tumor cell growth may be attained. As discussed in other chapters, using modifications of the two-layer system, one can assess both local cell-mediated and humoral factors that might influence in vitro kinetics and drug sensitivity. The next few years should see the acquisition and integration of valuable new information that should allow more rational approaches to the treatment of tumors by taking full advantage of information on both kinetics and drug sensitivity of clonogenic human tumor cells.

Topics: Agar; Antineoplastic Agents; Bone Marrow; Cell Cycle; Cell Division; Cell Survival; Clone Cells; Culture Media; Drug Evaluation, Preclinical; Humans; Neoplasms; Plasmacytoma

Topics: Agar; Cells, Cultured; Clone Cells; Culture Media; Drug Evaluation; Freezing; Humans; Neoplasms; Tissue Preservation

A simple method has been developed which facilitates the detailed cytogenetic analysis of proliferating tumour cells within clusters and colonies arising from clonogenic tumour stem cells in biopsy samples of human cancers. The method uses a simple agar cloning technique for human tumours, which provides marked enhancement in the number of cases with observable mitotic activity and the number of mitotic figures available for detailed karyotypic assessment. The frequency of mitotic figures in cluster and colony samples is much greater than is attainable with standard chromosomal techniques. This novel approach should prove to be a powerful tool for the study of human tumour karyology.

Topics: Agar; Cells, Cultured; Chromosomes, Human; Clone Cells; Female; Humans; Karyotyping; Methods; Middle Aged; Mitosis; Neoplasms

Topics: Absorption; Agar; Hot Temperature; Humans; Models, Structural; Neoplasms; Radiometry; Temperature

Topics: Agar; Animals; Cell Aggregation; Cell Division; Clone Cells; Cold Temperature; Culture Media; Humans; Mice; Mice, Nude; Neoplasm Transplantation; Neoplasms; Transplantation, Heterologous

A simple technique is described for fixing colony-containing layers of soft agar and drying them onto microscopic slides. The method is extrapolated from techniques used in immunology for permanent preservation of immunodiffusion or immunoelectrophoresis plates. Slides prepared in this fashion are eminently suitable for subsequent analysis with a variety of techniques including conventional Papanicolaou or other staining methods as well as histochemistry, immunofluorescence, and autoradiography. In addition to research applications, the technique may have diagnostic applications and should greatly enhance both qualitative and quantitative analysis of the biology of hematopoietic and tumor colony formation.

Topics: Agar; Clone Cells; Colony-Forming Units Assay; Hematopoietic Stem Cells; Histological Techniques; Humans; Neoplasms; Staining and Labeling

Two techniques for growing colonies of human tumour cells in soft agar have been applied to cell suspensions derived from fresh tumour tissue from 48 patients. Colonies were obtained in 31 cases, with plating efficiencies between 0.01 and 15%. In 11 cases the plating efficiencies were 1% or above. There was evidence that some categories of tumour grew more readily than others under these conditions. The potential applications of the methods to clinical and experimental oncology are discussed.

Topics: Agar; Animals; Clone Cells; Humans; Methods; Mice; Neoplasm Transplantation; Neoplasms; Transplantation, Heterologous

Colonies of human lymphocytes with T cell characteristics will grow in agar from repeated mitotic divisions with phytohaemagglutinin (PHA) stimulation. The colonies comprise spheres of tightly-packed cells with up to 500-1,000 blast-like cells in each colony. 65% of cells from pooled colonies bound AET-treated sheep red cells. 1,100-2,500 colonies/10(6) peripheral blood lymphocytes developed when cell donors were healthy but lower numbers (350-1,000 colonies/10(6) lymphocytes) were detected in blood from cancer patients. Comparison with other non-specific assays of cell-mediated immunity showed that while 66% of cancer patients were anergic (to five recall antigens) and 78% exhibited depressed mitotic activity in standard cultures with low dose PHA, 100% of these patients revealed T cell colony formation below normal. It is suggested that further studies of T lymphocyte colony-forming cells in healthy people and in a number of disease states may significantly advance our understanding of mechanisms of cell-mediated immunity.

Topics: Agar; Animals; Clone Cells; Humans; Immune Adherence Reaction; Lectins; Mitosis; Neoplasms; Sheep; Skin Tests; T-Lymphocytes

Topics: Agar; Androgens; Biological Assay; Electrophoresis; Estrogens; Humans; Neoplasms; Receptors, Cell Surface; Temperature

The frequency of M-components was studied by agar gel electrophoresis in sera from 807 patients, 467 (57%) females and 340 (43%) males with histologically proven solid malignant neoplasms.M-components were found in the sera of 40 male and 20 female patients. Apart from two known cases of multiple myeloma and one case of Waldenström's macroglobulinaemia, none of the patients were found to be suffering from these diseases. The frequency of M-components increased with age, and this was more evident in males. Twenty-two of 60 patients with M-components did not exhibit abnormalities on immunoelectrophoresis. Of the 35 remaining patients, 27 had an abnormal component of the IgG class, 6 of the IgA and 2 of the IgM class. M-components were found in the sera of patients with a wide variety of neoplasms. There appeared to be no evidence of an increased frequency of M-components in the sera of patients with solid malignant neoplasms compared with normal adult population.

Topics: Adolescent; Adult; Agar; Aged; Child; Electrophoresis; Female; Gastrointestinal Neoplasms; Genital Neoplasms, Female; Humans; Immunoelectrophoresis; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Immunoglobulins; Lung Neoplasms; Male; Middle Aged; Multiple Myeloma; Neoplasms; Urinary Bladder Neoplasms; Waldenstrom Macroglobulinemia

Topics: Abdominal Neoplasms; Agar; Aged; Antigens, Neoplasm; Breast Neoplasms; Cell Division; Cells, Cultured; Clone Cells; Colonic Neoplasms; Female; Humans; Immune Sera; Immunity, Cellular; Kidney Neoplasms; Liposarcoma; Lymphocytes; Male; Melanoma; Methods; Middle Aged; Neoplasms; Prostatic Neoplasms; Rectal Neoplasms; Thyroid Neoplasms

Topics: Agar; Animals; Antineoplastic Agents; Arsenicals; Breast Neoplasms; Cell Survival; Depression, Chemical; DNA Nucleotidyltransferases; DNA, Neoplasm; Dogs; Drug Evaluation, Preclinical; Humans; In Vitro Techniques; Iodoacetates; Leukocytes; Mice; Neoplasms; Succinate Dehydrogenase; Thymidine; Tritium

Topics: Agar; Antineoplastic Agents; Drug Resistance; Female; Humans; In Vitro Techniques; Methods; Methylene Blue; Neoplasms; Oxidoreductases; Prognosis; Tissue Extracts

Topics: Agar; Animals; Antineoplastic Agents; Carbon Isotopes; Drug Resistance; Humans; In Vitro Techniques; Leukemia; Methods; Methylene Blue; Motion Pictures; Neoplasms; Neoplasms, Experimental; Neoplastic Cells, Circulating; Prognosis; Sulfhydryl Reagents; Tritium

Topics: Agar; Carcinoma; Electrophoresis; Gels; Half-Life; Hodgkin Disease; Humans; Isoenzymes; L-Lactate Dehydrogenase; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Leukocytes; Lymphatic Diseases; Lymphoma; Neoplasms; Osteosclerosis; Plasmacytoma; Sarcoma; Tissue Extracts

Topics: Agar; Alkylating Agents; Antineoplastic Agents; Culture Techniques; DNA, Neoplasm; Fluorouracil; Humans; Mechlorethamine; Methods; Methotrexate; Neoplasms; Neoplastic Cells, Circulating; Radioisotopes; Sulfhydryl Compounds

Topics: Adenocarcinoma; Adult; Agar; Animals; Antineoplastic Agents; Anus Neoplasms; Breast Neoplasms; Carcinoma, Squamous Cell; DNA; Dogs; Humans; Leucine; Leukocytes; Liver; Mice; Middle Aged; Neoplasms; Neoplasms, Experimental; Parotid Neoplasms; Proteins; Radioisotopes; Rectal Neoplasms; RNA; Sulfhydryl Compounds; Thoracic Neoplasms; Thymidine; Uridine

Topics: Agar; Chemistry Techniques, Analytical; Chromatography, DEAE-Cellulose; Filtration; gamma-Globulins; Gels; Humans; Immunodiffusion; Immunoelectrophoresis; Immunoglobulins; Neoplasms

Topics: Adolescent; Adult; Agar; Aged; Anti-Bacterial Agents; Antineoplastic Agents; Autopsy; Belgium; Candida; Child; Cortisone; Digestive System; Female; Fungi; Humans; Male; Middle Aged; Mycoses; Neoplasms; Respiratory System; Sucrose

Topics: Agar; Aged; Blood Protein Electrophoresis; Breast Neoplasms; Carcinoma, Bronchogenic; Colonic Neoplasms; Esophageal Neoplasms; Female; gamma-Globulins; Humans; Kidney Neoplasms; Lung Neoplasms; Middle Aged; Neoplasm Metastasis; Neoplasms; Stomach Neoplasms

Topics: Agar; Electrophoresis; Gels; Humans; Methods; Neoplasms; Phospholipids; Pneumonia; Rheumatic Diseases

Topics: Agar; Albumins; Atrophy; Central Nervous System Diseases; Cerebrospinal Fluid Proteins; Electrophoresis; gamma-Globulins; Humans; Immunochemistry; Immunodiffusion; Immunoelectrophoresis; Immunoglobulin G; Infections; Methods; Multiple Sclerosis; Neoplasms; Peripheral Nervous System Diseases; Syphilis

Topics: Agar; Agglutination Tests; Antibodies; Benzopyrenes; Complement Fixation Tests; Hemagglutination Tests; Humans; Latex Fixation Tests; Neoplasms; Precipitin Tests; Serum Albumin

Topics: Agar; Antineoplastic Agents; Female; Heparinoids; Humans; Leukemia; Male; Neoplasm Metastasis; Neoplasms; Radiation Effects

Topics: Agar; Anemia, Hypochromic; Anemia, Pernicious; Clinical Enzyme Tests; Electrophoresis; Female; Hodgkin Disease; Humans; Isoenzymes; L-Lactate Dehydrogenase; Lymphoma, Large B-Cell, Diffuse; Male; Neoplasms

Topics: Agar; Animals; Child; Cricetinae; Culture Techniques; Fetus; Humans; Methods; Mitosis; Neoplasms

Topics: Agar; Anemia, Hemolytic; Diagnosis, Differential; Electrophoresis; Gels; Humans; Isoenzymes; Kidney Diseases; L-Lactate Dehydrogenase; Liver Diseases; Myocardial Infarction; Neoplasms; Prognosis

Topics: Agar; Biliary Tract Diseases; Blood Protein Electrophoresis; Electrophoresis; gamma-Globulins; Heart Diseases; Humans; Immunodiffusion; Immunoelectrophoresis; Liver Diseases; Lung Diseases; Methods; Neoplasms; Paper

Topics: Agar; Electrophoresis; Gels; Gonadal Steroid Hormones; Humans; L-Lactate Dehydrogenase; Neoplasms

Topics: Adult; Agar; Aged; Anemia; Blood Proteins; Breast Neoplasms; Bronchitis; Colitis; Electrophoresis; Female; Gels; Humans; Infections; Inflammation; Male; Middle Aged; Neoplasms; Orchitis; Pneumonia; Testicular Neoplasms

Topics: Agar; Anemia, Hemolytic; Blood; Clinical Enzyme Tests; Electrophoresis; Histocytochemistry; Humans; In Vitro Techniques; Kidney Diseases; L-Lactate Dehydrogenase; Liver Diseases; Myocardial Infarction; Neoplasms; Pleural Effusion

Topics: Adenoviridae; Agar; Animals; Arboviruses; Ascites; Avian Sarcoma Viruses; Cricetinae; Encephalitis Viruses; Encephalomyocarditis virus; Enterovirus; Enterovirus B, Human; Forests; Herpesviridae; In Vitro Techniques; Influenza A virus; Neoplasms; Neoplasms, Experimental; Orthomyxoviridae; Paramyxoviridae Infections; Poliovirus; Polyomavirus; Rabies virus; Reoviridae; Research; Rous sarcoma virus; Semliki forest virus; Sendai virus; Simplexvirus; Tissue Culture Techniques; Vaccinia virus; Vertebrates; Virus Cultivation; Viruses

Topics: Agar; Immunoelectrophoresis; Lipids; Lipoproteins; Neoplasms; Precipitin Tests; Tuberculosis

Topics: Agar; Animals; Antigens; Immunodiffusion; Leukemia; Leukemia, Experimental; Mice; Neoplasms; Oncogenic Viruses; Research

Topics: Agar; Animals; Neoplasms; Neoplasms, Experimental; Sarcoma; Sarcoma, Avian; Sarcoma, Experimental

Topics: Agar; Biophysical Phenomena; Neoplasms; Research

Topics: Agar; Biophysical Phenomena; Carcinoma; Humans; Neoplasms

Topics: Agar; Antiemetics; Hemoglobins; Humans; Neoplasms; Serum Albumin; Tissue Extracts

Topics: Agar; Animals; Chickens; Humans; Neoplasms; Sarcoma

Topics: Agar; Antigens; Climate; Humans; Immune System Phenomena; Neoplasms

Topics: Agar; Humans; Neoplasms; Research

Topics: Agar; Animals; Antigens; Chickens; Neoplasms; Sarcoma; Sarcoma, Avian

Topics: Agar; Animals; Antigens; Climate; Communication; Immune System Phenomena; Neoplasms; Sarcoma, Avian

Topics: Agar; HeLa Cells; Humans; Neoplasms

Topics: Agar; Humans; Neoplasms

Topics: Agar; Humans; Neoplasms

Topics: Agar; Animals; Antigens; Chickens; Humans; Neoplasms; Sarcoma; Software

Topics: Adenoma; Agar; Neoplasms; Parathyroid Glands; Parathyroid Neoplasms; Tissue Culture Techniques

Topics: Agar; Genitalia; Genitalia, Female; Gynecology; Neoplasms

Topics: Agar; Anxiety; Neoplasms; Neoplasms, Nerve Tissue; Rheumatic Diseases

Topics: Agar; Humans; Neoplasms

Topics: Agar; Biophysical Phenomena; Neoplasms

Topics: Agar; Antineoplastic Agents; Ascites; Humans; Neoplasms

Topics: Agar; Neoplasms

Topics: Agar; Anti-Bacterial Agents; Antibiotics, Antitubercular; Dermatologic Agents; Humans; Neoplasms

Topics: Agar; Humans; Indicator Dilution Techniques; Neoplasms

Topics: Agar; Animals; Antineoplastic Agents; Humans; Neoplasms; Neoplasms, Experimental