carbocyanines and Lymphoma

Recent innovations in the treatment of multiple myeloma have enriched our therapeutic repertoire regarding the treatment of multiple myeloma during the last decades. However, despite today's therapies many multiple myeloma (MM) patients experience relapse of disease and eventually remain incurable. Wnt/β-catenin signaling has been demonstrated in lymphoma and MM, rendering related signaling molecules promising therapeutic targets. Fenofibrate, an extensively scrutinized and widely used drug for primary hypercholesterolemia or mixed dyslipidemia, has proven anticarcinogenic properties mediated by peroxisome proliferator-activated receptor-alpha (PPARα) agonism, thereby also influencing WNT-associated signaling molecules.. The antitumor apoptotic effect of fenofibrate at doses ranging from 0.1-200 μM was investigated on a total of seven human, two murine myeloma/lymphoma cell lines and two healthy control cell lines, as determined by 3'3-Dihexyloxacarbocyanine iodide (DiOC6) and propidium iodide (PI) staining in flow cytometry.. Fenofibrate significantly reduced viability due to apoptosis induction in all investigated myeloma and lymphoma cell lines in a dose-dependent manner, whereas healthy control cells were less sensitive.. Our results provide a rationale for future in vitro and in vivo studies with fenofibrate as a safe and well-tolerated agent in MM and lymphoma treatment.

Topics: Anticarcinogenic Agents; Apoptosis; beta Catenin; Carbocyanines; Cell Line, Tumor; Fenofibrate; Humans; Lymphoma; Multiple Myeloma; Staining and Labeling; Wnt Signaling Pathway

Quantification of tumor necrosis in cancer patients is of diagnostic value as the amount of necrosis is correlated with disease prognosis and it could also be used to predict early efficacy of anti-cancer treatments. In the present study, we identified two near infrared fluorescent (NIRF) carboxylated cyanines, HQ5 and IRDye 800CW (800CW), which possess strong necrosis avidity. In vitro studies showed that both dyes selectively bind to cytoplasmic proteins of dead cells that have lost membrane integrity. Affinity for cytoplasmic proteins was confirmed using quantitative structure activity relations modeling. In vivo results, using NIRF and optoacoustic imaging, confirmed the necrosis avid properties of HQ5 and 800CW in a mouse 4T1 breast cancer tumor model of spontaneous necrosis. Finally, in a mouse EL4 lymphoma tumor model, already 24 h post chemotherapy, a significant increase in 800CW fluorescence intensity was observed in treated compared to untreated tumors. In conclusion, we show, for the first time, that the NIRF carboxylated cyanines HQ5 and 800CW possess strong necrosis avid properties in vitro and in vivo. When translated to the clinic, these dyes may be used for diagnostic or prognostic purposes and for monitoring in vivo tumor response early after the start of treatment.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Carbocyanines; Cell Death; Cell Line, Tumor; Disease Models, Animal; Female; Fluorescent Dyes; Humans; Lymphoma; Mammary Neoplasms, Experimental; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Confocal; Necrosis; Quantitative Structure-Activity Relationship; Random Allocation

Increasing literature suggests that cell adhesion molecule alpha4beta1 integrin plays a pivotal role in autoimmune diseases and cancer development. Noninvasive visualization of alpha4beta1 integrin in vivo will facilitate the understanding of its involvement in disease progression and development of targeted therapies. Due to the lack of high-affinity targeting ligands, molecular imaging of alpha4beta1 integrin is much less explored than that of alphavbeta3 and alphavbeta5 integrins. We have recently reported using the one bead-one compound combinatorial library method to identify a peptidomimetic, LLP2A, that preferentially binds to activated alpha4beta1 integrin. Here, we described the use of LLP2A-Cy5.5 conjugate as an in vivo optical imaging probe in a human lymphoma xenograft model. This univalent LLP2A-Cy5.5 conjugate retained the binding activity and specificity to alpha4beta1 integrin as shown by cell binding assays using alpha4beta1-positive Molt-4 T-leukemia cells. The subcutaneous Molt-4 tumor was clearly visualized from 1 to 24 h after tail vein injection of the conjugate. Direct imaging and confocal microscopic examination of excised tumors and organs confirmed the accumulation of LLP2A in tumors and revealed very little or no uptake in normal organs except for lymph nodes. Kidney uptake was high when the whole organ was scanned but it was negative when examined microscopically, suggesting that LLP2A bound to the renal tubules loosely. Tumor uptake of LLP2A-Cy5.5 conjugate was blocked by excess unlabeled LLP2A. This study showed that the combinatorial chemical library-derived peptidomimetic LLP2A can be easily developed into an optical imaging probe for noninvasively monitoring of activated alpha4beta1 integrin in vivo.

Topics: Animals; Biomimetics; Carbocyanines; Female; Fluorescent Dyes; Humans; Integrin alpha4beta1; Lymphoma; Mice; Mice, Nude; Models, Biological; Neoplasm Transplantation; Peptide Library; Substrate Specificity; Tomography, Optical; Transplantation, Heterologous; Tumor Cells, Cultured; Whole Body Imaging

Much attention has been focused on the manner in which tumour cells die after treatment with cytotoxic agents. The basic question is whether cells die via apoptosis or via direct damage from the toxic agent. Various assays have been used to make this distinction. However, we show herein that some of the widely used assays for apoptosis do not in fact distinguish between apoptosis and other forms of cell death. More specifically: (1) A sub-G1 DNA content, identified by propidium iodide staining, does not distinguish between apoptotic and necrotic cells; (2) loss of mitochondrial membrane potential does not distinguish between apoptotic and necrotic cells, unless combined with an assay for an intact cell membrane; (3) subcellular fragments that arise from dead cells or from apoptotic bodies can interfere with some assays for apoptosis such as annexin V staining, as they may be close to the size of intact cells, making it difficult to decide where to set the size threshold; (4) irradiated cells display a large increase in nonspecific Ab binding. This may be partly due to an increase in cell size, but, regardless of the cause, it can lead to a mistaken conclusion that there is an increase in a particular antigen if appropriate control reagents are not tested; and (5) experiments utilising Ab crosslinking have neglected the role of cell aggregation, which can cause multiple problems including death from mechanical stress when cells are handled. Consideration of these factors will improve our ability to determine the mode of cell death.

Topics: Annexin A5; Apoptosis; Benzimidazoles; Carbocyanines; Cell Aggregation; Cell Line, Tumor; Collagen Type XI; DNA, Neoplasm; Humans; Jurkat Cells; Lymphoma; Membrane Potential, Mitochondrial; Poly(ADP-ribose) Polymerases; Propidium

Growth hormone (GH) is produced by immunocompetent cells and has been implicated in the regulation of a multiplicity of functions in the immune system involved in growth and activation. However, the actions of endogenous or lymphocyte GH and its contribution to immune reactivity when compared with those of serum or exogenous GH are still unclear. In the present study, we overexpressed lymphocyte GH in EL4 lymphoma cells, which lack the GH receptor (GHR), to determine the role of endogenous GH in nitric oxide (NO) production and response to genotoxic stress. Western blot analysis demonstrated that the levels of GH increased approximately 40% in cells overexpressing GH (GHo) when compared with cells with vector alone. The results also show a substantial increase in NO production in cells overexpressing GH that could be blocked by N(G)-monomethyl-L-arginine (L-NMMA), an L-arginine analogue that competitively inhibits all three isoforms of nitric oxide synthase (NOS). No evidence was obtained to support an increase in peroxynitrite in cells overexpressing GH. Overexpression of GH increased NOS activity, inducible nitric oxide synthase (iNOS) promoter activity, and iNOS protein expression, whereas endothelial nitric oxide synthase and neuronal nitric oxide synthase protein levels were essentially unchanged. In addition, cells overexpressing GH showed increased arginine transport ability and intracellular arginase activity when compared with control cells. GH overexpression appeared to protect cells from the toxic effects of the DNA alkylating agent methyl methanesulfonate. This possibility was suggested by maintenance of the mitochondrial transmembrane potential in cells overexpressing GH when compared with control cells that could be blocked by L-NMMA. Taken together, the data support the notion that lymphocyte GH, independently of the GH receptor, may play a key role in the survival of lymphocytes exposed to stressful stimuli via the production of NO.

Topics: Animals; Arginine; Carbocyanines; Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; Cells, Cultured; Dose-Response Relationship, Drug; Drug Resistance; Growth Hormone; Immune System; Lymphocytes; Lymphoma; Membrane Potentials; Methyl Methanesulfonate; Mice; Mitochondria; Nitric Oxide; Nitric Oxide Synthase; omega-N-Methylarginine; Protein Transport; Receptors, Somatotropin; Stress, Physiological

Simultaneous analysis of DNA and immunophenotype of lymphoma cells by flow cytometry allows the calculation of the proliferative activity and aneuploidy in even a small lymphoma population. Unfavorable DNA binding characteristics or spectral features of DNA dyes impair the accuracy of multiparameter DNA analysis and limit their clinical application. We describe here a reliable and reproducible application of both three- and four-color multiparameter DNA analysis.. After immunostaining of fresh samples of peripheral blood, bone marrow and single cell suspensions of lymph nodes from healthy and lymphoma patients, a methanol fixation for TO-PRO-3 and DRAQ5 staining was tested.. The red-excitable TO-PRO-3 on a FACSCalibur is limited to two-color antigen staining including fluorescein-isothiocyanate and phycoerythrin-labeled monoclonal antibodies due to its broad excitation spectrum. Although DRAQ5 is only applicable to flow cytometers equipped with a single argon laser emitting 488-nm light, its emission spectrum can be easily separated from the FITC, PE, and PE/Texas-Red emissions. DRAQ5 showed almost identical stoichiometric DNA binding characteristics as propidium iodide. Coefficient of variation produced by DRAQ5 staining is in the range of 3.5 and is adequate for detecting aneuploid amd near-diploid cells.. These advantageous features of DRAQ5 make it a reliable candidate for multiparameter clinical studies.

Topics: Anthraquinones; Biomarkers, Tumor; Carbocyanines; Cell Line, Tumor; DNA, Neoplasm; Flow Cytometry; Fluorescent Antibody Technique; Humans; Immunophenotyping; Lymphocytes; Lymphoma; Nitrogen Oxides; Reproducibility of Results; Staining and Labeling