sincalide and Carcinoma--Squamous-Cell

The purpose of the present study was to investigate the potentials of circ_0000311 in oral squamous cell carcinoma (OSCC). Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for calculating the mRNA and miRNA level. Western blot was performed to determine protein expression. The binding sites between miR-876-5p and circ_0000311/Enhancer of zeste homolog-2 (EZH2) were predicted using bioinformatics tools and confirmed by luciferase and RNA pull-down assays. Cell proliferation was detected using CCK-8 and colony formation assay. Cell migration and invasion were detected using transwelll assay. Cellular functions were determined using CCK-8, colony, and transwell assay. The results showed that circ_0000311 was overexpressed in OSCC tissues and cells. However, circ_0000311 knockdown impeded the proliferation and epithelial-mesenchymal transition (EMT) of OSCC cells. Circ_0000311 targeted miR-876-5p, down-regulation of which promoted the aggressiveness of OSCC. Additionally, circ_0000311 sponged miR-876-5p to up-regulate a key regulator of EMT EZH2, which promoted the proliferation and aggressiveness of OSCC. Taken together, circ_0000311 aggravated the OSCC progression via regulating miR-876-5p/EZH2 axis.

Topics: Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Proliferation; Enhancer of Zeste Homolog 2 Protein; Head and Neck Neoplasms; Humans; MicroRNAs; Mouth Neoplasms; RNA, Circular; Sincalide; Squamous Cell Carcinoma of Head and Neck

The ubiquitin ligase family member triplex motif protein 21 (TRIM21), which is involved in the proliferation, metastasis, and selective death of tumor cells, is crucial in the ubiquitination of a number of tumor marker proteins. As research progresses, more studies demonstrate that TRIM21 expression levels can be used to predict cancer prognosis. However, it is unclear how exactly TRIM21 contributes to cervical squamous carcinoma.. Immunohistochemistry, Western Blot, and q-PCR were utilized to determine the expression level of TRIM21 in 113 patients with CESC removed by stage I surgery at Xijing Hospital from 2018 to 2023 using paraffin-embedded tumor tissues and 12 pairs of fresh tumor tissues and their paracancerous tissues. Log-rank analysis using SPSS 23.0 was performed for prognosis and survival analysis using univariate/multifactorial analysis. CCK-8, wound-healing and Scratch assay verified that TRIM21 promoted cell proliferation, migration and invasion. The effect of overexpression and knockdown of TRIM21 on tumor stemness was examined using sphere-forming assay and Western Blot. Finally, we constructed a xenograft model to observe the effect of TRIM21 on tumorigenesis in Si Ha cell lines in vivo.. TRIM21 expression is greater in CESC tissues than in paracancerous tissues, according to immunohistochemical data. Similarly, at the protein and mRNA levels, we verified this conclusion using Western-Blotting and q-PCR. Prognostic and OS analysis showed that TRIM21 expression levels are associated with individual prognostic factors. CCK-8, Wound healing, Transwell, and Sphere-forming tests all demonstrated that TRIM21 overexpression enhances Ca Ski cell proliferation, migration, invasion, and stemness. TRIM21 knockdown in Si Ha inhibited tumor cell proliferation, migration, invasion, and stemness. The experimental results of xenograft models demonstrated that TRIM21 knockdown in Si Ha cells inhibited tumor development.. TRIM21 is a poor predictor of prognosis for cervical squamous cell carcinoma and might open up new avenues for investigation into therapeutic targets.

Topics: Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Proliferation; Female; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Proteins; Neoplastic Processes; Prognosis; Sincalide; Uterine Cervical Neoplasms

The study was performed to ascertain the mechanism of sodium butyrate (NaB) mediating the proliferative and invasive properties of oral squamous cell carcinoma (OSCC) cells. The cell proliferative, migrating, and invasive potentials were detected by CCK-8, colony formation, EdU, and Transwell assays. The expression of proliferation- and invasion-related proteins, HDAC1, and HSPB7 in OSCC cells were evaluated by western blot. Immunofluorescence was also performed to evaluate the HDAC1 expression. The enrichment of histone deacetylase HDAC1 in the promoter region of HSPB7 was assessed by the ChIP assay. In vivo growth of OSCC cells was measured by tumorigenesis in nude mice (n=18). The t-test was employed for comparisons of data between the two groups. One-way ANOVA was utilized for comparisons of data among multiple groups, and repeated-measures ANOVA for comparisons of data at different time points among groups, followed by Bonferroni post-hoc test. The data showed that HDAC1 expression was highly upregulated in OSCC cells compared to human normal oral keratinocytes (HNOKs) (p<0.0001), and NaB diminished the HDAC1 expression in OSCC cells. NaB restricted OSCC cell proliferative, migrating, and invasive capabilities by downregulating HDAC1. HSPB7 expression was downregulated in OSCC cells versus HNOKs (p<0.0001). HDAC1 inversely orchestrated the HSPB7 expression in OSCC cells through histone deacetylation modification, and NaB augmented the HSPB7 expression by inhibiting HDAC1. Moreover, NaB inhibited OSCC cell growth in vivo by elevating HSPB7 levels through the HDAC1 repression. In conclusion, NaB restrained cell proliferation and invasion in OSCC cells via HSPB7 upregulation by decreasing the HDAC1 expression.

Topics: Animals; Butyric Acid; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Proliferation; Gene Expression Regulation, Neoplastic; Head and Neck Neoplasms; Histone Deacetylase 1; Histone Deacetylases; Histones; HSP27 Heat-Shock Proteins; Humans; Mice; Mice, Nude; MicroRNAs; Mouth Neoplasms; Sincalide; Squamous Cell Carcinoma of Head and Neck

The N. The cellular phenotypes of OSCC cells were determined by CCK-8 and transwell migration assays. The energy metabolism was detected using glucose uptake/lactate production assay and extracellular acidification rate analysis. The molecular interaction was tested by  RNA immunoprecipitation  assay.. Here, results indicated that IGF2BP2 was up-regulated in OSCC and that it acted as a predictor of poor prognosis. IGF2BP2 promoted the proliferation, migration and Warburg effect of OSCC cells in vitro. Mechanistical assays illustrated that IGF2BP2 directly interacted with HK2 mRNA by binding the 3'-UTR m

Topics: 3' Untranslated Regions; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Gene Expression Regulation, Neoplastic; Glucose; Head and Neck Neoplasms; Humans; Lactates; MicroRNAs; Mouth Neoplasms; RNA-Binding Proteins; Sincalide; Squamous Cell Carcinoma of Head and Neck

Lung squamous cell carcinoma (LSCC) is a prevalent and progressive subtype of lung cancer. This study aimed to substantiate the regulatory effect of the PAK2/SOX2/DEK axis on the LSCC development. LSCC tissues (n = 83) and adjacent normal tissues were collected and SOX2 expression was determined by qRT-PCR and Western blotting. Correlation between SOX2 expression and the prognosis of LSCC patients was then explored utilizing Kaplan-Meier analysis. Co-immunoprecipitation and glutathione-S-transferase pull-down assays were conducted to validate the binding of SOX2 to DEK. Gain- and loss- of function assays were then performed on LSCC cells, with CCK-8 and Transwell assays applied to detect the malignant behaviors of cells. A mouse xenograft model of LSCC was further established for in vivo validation. The expression levels of SOX2, PAK2 and DEK were up-regulated in LSCC tissues and cells. SOX2 overexpression was correlated with poor prognosis of LSCC patients. Knockdown of SOX2 weakened the viability and the migratory and invasive potential of LSCC cells. Further, PAK2 directly interacted with SOX2. PAK2 overexpression accelerated the malignant phenotypes of LSCC cells through interplay with SOX2. Moreover, SOX2 activated the expression of DEK, and silencing DEK attenuated the malignant behaviors of LSCC cells. In conclusion, PAK2 could bind to the transcription factor SOX2 and thus activate the expression of DEK, thereby driving the malignant phenotypes of LSCC cells both in vivo and in vitro.

Topics: Animals; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Chromosomal Proteins, Non-Histone; Gene Expression Regulation, Neoplastic; Glutathione; Humans; Laryngeal Neoplasms; Lung; Lung Neoplasms; Mice; MicroRNAs; Oncogene Proteins; p21-Activated Kinases; Poly-ADP-Ribose Binding Proteins; Sincalide; SOXB1 Transcription Factors

Oral squamous cell carcinoma (OSCC) is characterized by high recurrence and metastasis and places a heavy burden on societies worldwide. Cancer cells thrive in a changing microenvironment by reprogramming lipidomic metabolic processes to provide nutrients and energy, activate oncogenic signaling pathways, and manage redox homeostasis to avoid lipotoxicity. The mechanism by which OSCC cells maintain lipid homeostasis during malignant progression is unclear.. The altered expression of fatty acid (FA) metabolism genes in OSCC, compared with that in normal tissues, and in OSCC patients with or without recurrence or metastasis were determined using public data from the TCGA and GEO databases. Immunohistochemistry was performed to examine the carboxylesterase 2 (CES2) protein level in our own cohort. CCK-8 and Transwell assays and an in vivo xenograft model were used to evaluate the biological functions of CES2. Mass spectrometry and RNA sequencing were performed to determine the lipidome and transcriptome alterations induced by CES2. Mitochondrial mass, mtDNA content, mitochondrial membrane potential, ROS levels, and oxygen consumption and apoptosis rates were evaluated to determine the effects of CES2 on mitochondrial function in OSCC.. We demonstrated that CES2 downregulation plays an important role in OSCC by maintaining lipid homeostasis and reducing lipotoxicity during tumor progression and may provide a potential therapeutic target for OSCC.

Topics: Carboxylesterase; Carboxylic Ester Hydrolases; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Diglycerides; DNA, Mitochondrial; Fatty Acids, Nonesterified; Head and Neck Neoplasms; Homeostasis; Humans; Mitochondria; Mouth Neoplasms; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; Reactive Oxygen Species; Signal Transduction; Sincalide; Squamous Cell Carcinoma of Head and Neck

Topics: Animals; Cadherins; Carbon Monoxide; Carcinoma, Squamous Cell; Humans; Kelch-Like ECH-Associated Protein 1; Mice; Mice, Nude; NF-E2-Related Factor 2; Organometallic Compounds; Signal Transduction; Sincalide; Tongue; Tongue Neoplasms; Water

Cancer-associated fibroblasts (CAFs) within the tumor microenvironment are key players in tumorigenesis and tumor development. Nevertheless, the regulatory mechanisms of CAFs on lung squamous cell carcinoma- (LUSC-) associated remain poorly elucidated.. The microarray dataset GSE22874, containing 30 specimens of primary culture of normal fibroblasts (NFs) and 8 specimens of cancer-associated fibroblasts (CAFs) samples derived from LUSC, was retrieved from the Gene Expression Omnibus (GEO) database and then calculated by using the R language (limma package) to identify differentially expressed genes (DEGs). CAF-conditioned medium (CAF-CM) was collected and used to culture LUSC cells, followed by assessment of cell proliferation, apoptosis, and oxidative stress levels by using CCK-8, annexin V-FITC/PI double staining and ELISA assays. Subsequently, COL10A1 was knocked down in CAFs to assess the role of COL10A1 in CAF regulation of LUSC behavior. Bioinformatics online analysis and MeRIP were applied to predict and test the m. Elevated expression of COL10A1 was found in LUSC-derived CAFs by GSE22874 dataset analysis. We discovered that COL10A1 and METTL3 was expressed in both LUSC cells and matched CAFs, while COL10A1 expression was prominently higher in CAFs than in LUSC cells. CAF-CM memorably encouraged LUSC cell proliferation and suppressed apoptosis-induced oxidative stress, which was reversed by interfering with COL10A1 expression in CAFs, suggesting that COL10A1 might be secreted by CAFs into the culture medium to exert its effects inside LUSC cells. Global m. COL10A1 secreted by CAFs could facilitate LUSC cell proliferation and repress apoptosis-induced oxidative stress, and the mechanism was due to elevated expression mediated by METTL3 promoting its mRNA m

Topics: Animals; Apoptosis; Cancer-Associated Fibroblasts; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Collagen Type X; Culture Media, Conditioned; Fibroblasts; Lung; Lung Neoplasms; Methylation; Methyltransferases; Mice; Mice, Nude; Oxidative Stress; RNA, Messenger; Sincalide

Laryngeal squamous cell carcinoma (LSCC) is one of the most common malignant tumors, and the main cause of death is metastasis. Overexpression of aurora kinase A (AURKA) plays an important role in the metastasis of LSCC. However, the mechanism by which AURKA promotes the metastasis of LSCC is poorly understood. Recent accumulating evidence indicates that epithelial-mesenchymal transition (EMT) may be one of the mechanisms of tumor metastasis. In the present study, we studied whether AURKA may induce EMT to promote the metastasis of LSCC. CCK-8 and plate colony-formation assays were carried out to show that AURKA significantly promoted the proliferation of Hep2 cells. Immunofluorescence staining and western blotting showed that EMT-related proteins changed in a time-dependent manner along with the alteration of AURKA, with decreased expression of N-cadherin, vimentin and slug and increased expression of E-cadherin. Additionally, downregulation of the expression of AURKA inhibited FAK/PI3K pathway activity. Inhibition of the FAK/PI3K pathway caused less mesenchymal-like characteristics and reduced the mobility, migration and invasion of Hep2 cells. In conclusion, AURKA may induce EMT to promote metastasis via activation of the FAK/PI3K pathway in LSCC. Those regulatory factors may present new diagnostic biomarkers and potential therapeutic targets for LSCC.

Topics: Aurora Kinase A; Cadherins; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Proliferation; Down-Regulation; Epithelial-Mesenchymal Transition; Focal Adhesion Kinase 1; Gene Expression Regulation, Neoplastic; Head and Neck Neoplasms; Humans; Laryngeal Neoplasms; Lymphatic Metastasis; Neoplasm Invasiveness; Phosphatidylinositol 3-Kinases; Signal Transduction; Sincalide; Snail Family Transcription Factors; Squamous Cell Carcinoma of Head and Neck; Vimentin

Kallmann syndrome 1 sequence gene (KAL1) protein is an extracellular matrix associated protein which plays vital roles in neurons development and cell migration. However, its biological functions and clinical implications have yet not been revealed in oral carcinogenesis. The objective of the study was to evaluate the role of KAL1 in oral cancer and determine clinical significance of KAL1 in oral squamous cell carcinomas (OSCCs).. The expression pattern of KAL1 was examined in a testing cohort including OSCCs (n = 42) and paired adjacent tissues (PATs) (n = 14) by real-time PCR. The result was further validated in a validating cohort of OSCCs (n = 32). Correlation between clinicopathological parameters and KAL1 mRNA levels was analyzed by Kruskal-Wallis test. In vitro, the effects of KAL1 ablation through siRNA-mediated knockdown on the proliferation of OSCC cells were determined by CCK-8, BrdU, and colonies formation assays, respectively. In addition, cell cycle distribution was further evaluated by cytometry.. We observed that remarkably decreased expression of KAL1 mRNA in two independent cohorts (P = 0.0002 and P = 0.033, respectively). Furthermore, downregulated KAL1 mRNA was significantly associated with worse pathological grade (P = 0.013 and P = 0.035, respectively). Upon KAL1 silencing, the proliferation and colonies formation potentials of OSCC cells were notably promoted by accelerating G1 to M phase transition.. These data indicated that KAL1 plays a potential suppressive role on OSCC initiation and progression, and KAL1 gene may serve as an adjuvant biomarker for the identification of pathological grade.

Topics: Bromodeoxyuridine; Carcinogenesis; Carcinoma, Squamous Cell; Cell Culture Techniques; Cell Cycle Checkpoints; Cell Differentiation; Cell Division; Cell Line, Tumor; Cell Proliferation; Cohort Studies; Disease Progression; Extracellular Matrix Proteins; Female; G1 Phase; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Gene Silencing; Humans; Male; Middle Aged; Mouth Mucosa; Mouth Neoplasms; Neoplasm Grading; Nerve Tissue Proteins; RNA, Small Interfering; Sincalide; Tumor Suppressor Proteins

Runt-related transcription factor 3 (RUNX3) is a tumor suppressor gene whose reduced expression may play an important role in the development and progression of esophageal squamous cell cancer (ESCC). The aim of this study was to investigate the clinical relevance of RUNX3 in ESCC patients and effects of overexpression on biological behaviour of Eca109 cells in vitro and in vivo. Immunohistochemistry was performed to detect the clinical relevance of RUNX3 and lymph node metastasis in 80 ESCC tissues and 40 non-cancerous tissues using the SP method. RT-PCR and Western blotting were applied to assess the RUNX3 level and verify the Eca109 cell line with stable overexpression. Localization of RUNX3 proteins was performed by cell immunofluorescence. CCK-8 and Scrape motility assays were used to determine proliferation and migration and the TUNEL assay to analyze cell apoptosis. Invasive potential was assessed in cell transwell invasion experiments. In nude mice, tumorigenesis in vivo was determined. Results showed decreased expression of RUNX3 in esophageal tissue to be significantly related to lymph node metastasis (LNM) (P<0.01). In addition, construction of a recombinant lentiviral vector and transfection into the human ESCC cell line Eca109 demonstrated that overexpression could inhibit cell proliferation, migration and invasion, and induce apoptosis. The in vivo experiments in mice showed tumorigenicity and invasiveness to be significantly reduced. Taken together, our studies indicate that underexpression of RUNX3 in human ESCC tissue is significantly correlated with progression. Restoration of RUNX3 expression significantly inhibits ESCC cells proliferation, migration, invasion and tumorigenesis.

Topics: Animals; Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Transformation, Neoplastic; Core Binding Factor Alpha 3 Subunit; Disease Progression; Esophageal Neoplasms; Esophageal Squamous Cell Carcinoma; Humans; Lymphatic Metastasis; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Invasiveness; RNA, Messenger; Sincalide; Tumor Suppressor Proteins

Forkhead box C2 (FOXC2) is a member of the winged helix/forkhead box (Fox) family of transcription factors. It has been suggested to regulate tumor vasculature, growth, invasion and metastasis, although it has not been studied in cervical cancer. Here, we analyzed FOXC2 expression in cervical tissues corresponding to different stages of cervical cancer development and examined its correlation with clinicopathological characteristics. In addition, we examined the effects of targeting FOXC2 on the biological behavior of human cervical cancer cells.. The expression of FOXC2 in normal human cervix, CIN I-III and cervical cancer was examined by immunohistochemistry and compared among the three groups and between cervical cancers with different pathological subtypes. Endogenous expression of FOXC2 was transiently knocked down in human Hela and SiHa cervical cells by siRNA, and cell viability and migration were examined by scratch and CCK8 assays, respectively.. In normal cervical tissue the frequency of positive staining was 25% (10/40 cases), with a staining intensity (PI) of 0.297 ± 0.520, in CIN was 65% (26/40 cases), with a PI of 3.00 ± 3.29, and in cancer was 91.8% (68/74 cases), with a PI of 5.568 ± 3.449. The frequency was 100% in adenocarcinoma (5/5 cases) and 91.3% in SCCs (63/69 cases). The FOXC2 positive expression rate was 88.5% in patients with cervical SCC stage I and 100% in stage II, showing significant differences compared with normal cervix and CIN. With age, pathologic differentiation degree and tumor size, FOXC2 expression showed no significant variation. On transient transfection of Hela and SiHa cells, FOXC2-siRNA inhibition rates were 76.2% and 75.7%; CCK8 results showed reduced proliferation and relative migration (in Hela cells from 64.5 ± 3.16 to 49.5 ± 9.24 and in SiHa cells from 60.1 ± 3.05 to 44.3 ± 3.98) (P < 0.05).. FOXC2 gene expression increases with malignancy, especially with blood vessel hyperplasia and invasion degree. Targeted silencing was associated with reduced cell proliferation as well as invasion potential.

Topics: Adenocarcinoma; Antigens, CD34; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Movement; Cell Proliferation; Female; Forkhead Transcription Factors; Gene Expression Regulation, Neoplastic; HeLa Cells; Humans; Lymphatic Metastasis; Middle Aged; Neoplasm Invasiveness; Neovascularization, Pathologic; RNA Interference; RNA, Small Interfering; Sincalide; Uterine Cervical Neoplasms

Centromere protein H (CENP-H) and Ki67 are overexpressed in some malignancies, but whether they are predictors of survival after primary resection for hypopharyngeal squamous cell carcinoma (HSCC) remains unknown.. We assessed immunohistochemical expression of CENP-H and Ki67 in 112 HSCC specimens collected between March 2003 and March 2005 for analysis by clinical characteristics. The Kaplan-Meier method was used to analyze relapse-free survival and logistic multivariate regression to determine risk factors of relapse-free survival. Cholecystokinin octapeptide assays and flow cytometry were used to examine cell proliferation and apoptosis after siRNA inhibition of CENP-H in HSCC cells.. Overall, 50 (44.6%) HSCC specimens showed upregulated CENP-H expression and 69 (61.6%) upregulated Ki67. An increased CENP-H protein level was associated with advanced cancer stage and alcohol history (P=0.012 and P=0.048, respectively) but an increased Ki67 protein level only with advanced cancer stage (P=0.021). Increased CENP-H or Ki67 were associated with short relapse-free survival (P<0.001 or P=0.009, respectively) and were independent predictors of relapse-free survival (P=0.001 and P=0.018, respectively). siRNA knockdown of CENP-H mRNA inhibited cell proliferation and promoted cancer cell apoptosis in vitro.. Upregulated CENP-H and Ki67 levels are significantly associated with short relapse-free survival in HSCC. These factors may be predictors of a relapsing phenotype in HSSC cases.

Topics: Adult; Aged; Aged, 80 and over; Apoptosis; Carcinoma, Squamous Cell; Cell Line, Tumor; Cell Proliferation; Chromosomal Proteins, Non-Histone; Disease-Free Survival; Female; Flow Cytometry; Humans; Hypopharyngeal Neoplasms; Ki-67 Antigen; Male; Middle Aged; Neoplasm Recurrence, Local; RNA Interference; RNA, Small Interfering; Sincalide

Regulatory peptides and their analogs are being extensively investigated as radiopharmaceuticals for cancer imaging and therapy. Receptors of the cholecystokinin family have been shown to be overexpressed in different types of neuroendocrine tumors. The purposes of this study were to evaluate the cholecystokinin octapeptide amide (CCK8) peptide tagged with a diethylenetriaminepentaacetic acid derivative (DTPAGlu) and to test whether a (111)In-labeled conjugate ((111)In-DTPAGlu-G-CCK8, a derivative containing the chelating agent DTPAGlu bound through a glycine linker at the N-terminal end of the bioactive peptide CCK8) is suitable for cholecystokinin-B receptor (CCKBR) imaging.. CCK8 was synthesized by solid-phase techniques and covalently coupled to DTPAGlu through a glycine linker at its amino terminus. The compound was labeled with (111)In. The radiochemical purity and stability of the compound were assessed by chromatographic methods. NIH-3T3 and A431 cells overexpressing CCKBR were used to characterize the in vitro properties of the compound. Nude mice bearing control and CCKBR-overexpressing A431 xenografts were used as an in vivo model.. DTPAGlu-G-CCK8 showed rapid and efficient labeling with (111)In. The radiolabeled conjugate showed specific binding to both cell lines overexpressing CCKBR. Binding was saturable, with a dissociation constant of approximately 20 nmol/L in both cell systems. Both cell lines showed internalization of the ligand after interaction with the receptor. Biodistribution studies showed rapid localization of (111)In-DTPAGlu-G-CCK8 on CCKBR-overexpressing A431 xenografts that was severalfold higher than that on control tumors at all time points tested. Unbound activity showed rapid clearance of over 80% through the kidneys by 30 min after injection. The labeled peptide conjugate was very stable in serum but showed a rapid breakdown after injection. Incubation with kidney homogenates suggested that most breakdown occurred in the kidneys, favoring the clearance of unbound activity.. Our findings indicate that the in vitro and in vivo characteristics of (111)In-DTPAGlu-G-CCK8 are favorable for CCKBR imaging, as the peptide shows high-affinity binding to the receptor, is internalized in CCKBR-expressing cells, and shows avid uptake in CCKBR-overexpressing xenografts, with rapid clearance of unbound radioactivity through the kidneys. Furthermore, the ease of synthesis, high labeling efficiency, and chemical stability of DTPAGlu make this chelating moiety an ideal candidate for widespread use in peptide radiolabeling for nuclear medicine applications.

Topics: 3T3 Cells; Animals; Carcinoma, Squamous Cell; Cell Line, Tumor; Humans; Metabolic Clearance Rate; Mice; Mice, Nude; Pentetic Acid; Radiopharmaceuticals; Receptor, Cholecystokinin B; Sincalide; Tissue Distribution; Tomography, Emission-Computed

The effects of cholecystokinin-octapeptide (CCK8), the biologically active C-terminal moiety of cholecystokinin (CCK), on the binding of epidermal growth factor (EGF) were studied in isolated rat pancreatic acini. CCK8 inhibited 125I-EGF binding in a dose-dependent manner. One-half maximal inhibition occurred at 5 X 10(-10)M, and maximal inhibition at 10(-8)M CCK8. This inhibitory effect was detectable within 5 minutes of addition of CCK8, and was not associated with enhanced degradation of 125I-EGF in incubation media. Unlabeled EGF exerted only a slightly greater inhibitory effect than CCK8 on 125I-EGF binding at equivalent molar concentrations. In contrast to CCK8, the gastrointestinal hormone vasoactive intestinal polypeptide (VIP) did not significantly alter EGF binding. CCK8 also inhibited EGF binding in mouse pancreatic acini, but did not alter binding in A-431 human carcinoma cells. These findings suggest that physiological levels of CCK may regulate EGF binding in the pancreas and other tissues with receptors for both hormones. They thus point to a previously unrecognized mechanism for hormonal interaction.

Topics: Animals; Appetite Depressants; Carcinoma, Squamous Cell; Cell Line; Cholecystokinin; Epidermal Growth Factor; ErbB Receptors; Female; Humans; Kinetics; Male; Pancreas; Peptide Fragments; Rats; Rats, Inbred Strains; Receptors, Cell Surface; Sincalide; Vulvar Neoplasms