tachyplesin-peptide--tachypleus-tridentatus and Liver-Neoplasms

To investigate the effects of tachyplesin on the cell cycle regulation in human hepatcarcinoma cells.. Effects of tachyplesin on the cell cycle in human hepatocarcinoma SMMC-7721 cells were assayed with flow cytometry. The protein levels of p53, p16, cyclin D1 and CDK4 were assayed by immunocytochemistry. The mRNA levels of p21(WAF1/CIP1) and c-myc genes were examined with in situ hybridization assay.. After tachyplesin treatment, the cell cycle arrested at G0/G1 phase, the protein levels of mutant p53, cyclin D1 and CDK4 and the mRNA level of c-myc gene were decreased, whereas the levels of p16 protein and p21(WAF1/CIP1) mRNA increased.. Tachyplesin might arrest the cell at G0/G1 phase by upregulating the levels of p16 protein and p21(WAF1/CIP1) mRNA and downregulating the levels of mutant p53, cyclin D1 and CDK4 proteins and c-myc mRNA, and induce the differentiation of human hepatocacinoma cells.

Topics: Antimicrobial Cationic Peptides; Carcinoma, Hepatocellular; Cell Cycle; DNA-Binding Proteins; Humans; Immunohistochemistry; Liver Neoplasms; Peptides, Cyclic; Tumor Cells, Cultured

To investigate the antitumor activities of tachyplesin on human hepatocellular carcinoma (HCC) cells.. Tachyplesin, isolated from acid extracts of Chinese horseshoe crab (Tachypleus tridentatus) hemocytes, was used to treat the human HCC cell line SMMC-7721. Effects of tachyplesin on the proliferation of SMMC-7721 cells were measured with trypan blue dye exclusion test and HE staining. The morphology and ultrastructure of the cells were examined by light microscopy and transmission electron microscopy, respectively. The activities of gamma-glutamyltransferase (gamma-GT) and tyrosine aminotransferase (TAT) were assayed with biochemical methods. The levels of alpha fetoprotein (alpha-FP), proliferating cell nuclear antigen (PCNA), p21( WAF1/CIP1) and c-myc were examined by immunocytochemistry.. After treatment with tachyplesin 3.0 mg/L, the proliferation of SMMC-7721 cells was inhibited significantly, with the cell growth inhibitory rate amounted to 55.57 % and the maximum cell mitotic index declined by 43.68 %. The morphology and ultrastructure underwent restorational alteration. The activity of gamma-GT declined while TAT activity increased obviously, and the levels of alpha-FP and PCNA decreased. Moreover, the expression of p21(WAF1/CIP1) protein was up-regulated and that of c-myc protein was down-regulated.. Tachyplesin could effectively inhibit the proliferation of hepatocarcinoma cells, reverse the malignant morphological and ultrastructural characteristics, alter the levels of enzymes and antigens, regulate the expression of differentiation-associated oncogene and tumor suppressor gene, and induce hepatocarcinama cell differentiation.

Topics: alpha-Fetoproteins; Animals; Antimicrobial Cationic Peptides; Antineoplastic Agents; Carcinoma, Hepatocellular; Cell Differentiation; Cell Division; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; DNA-Binding Proteins; gamma-Glutamyltransferase; Horseshoe Crabs; Humans; Liver Neoplasms; Microscopy, Electron; Peptides, Cyclic; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins c-myc; Tumor Cells, Cultured; Tyrosine Transaminase

The study on antitumor activities of marine bioactive substances is an important field in exploiting marine bioactive substances and antitumor drugs. And the induction of tumor cell differentiation is a new strategy for drug therapy of tumors. So the authors used tachyplesin, a marine bioactive substance, to investigate its effects on the differentiation of human hepatocarcinoma SMMC-7721 cells for further studying its antitumor activities and mechanisms.. Tachyplesin, which was isolated from hemocytes of horseshoe crab (Tachypleus tridentatus), was used to treat human hepatocarcinoma SMMC-7721 cells. Light microscopy and transmission electron microscopy were applied to examine the changes in morphology and ultrastructure of SMMC-7721 cells, respectively. The activities of alkaline phosphatase or the expression of AFP and PCNA were assessed by cytochemistry or immunocytochemistry.. In the cells treated with 3.0 micrograms/ml tachyplesin, the morphology and ultrastructure returned to be normal, the activity of alkaline phosphatase was decreased and the levels of AFP and PCNA were downregulated.. Tachyplesin might effectively reverse the malignant morphology and ultrastructure, change the activity of enzyme and the levels of antigens associated with hepatocarcinoma cell, and induce the differentiation of the human hepatocarcinoma SMMC-7721 cells.

Topics: Alkaline Phosphatase; alpha-Fetoproteins; Animals; Antimicrobial Cationic Peptides; Antineoplastic Agents; Carcinoma, Hepatocellular; Cell Differentiation; DNA-Binding Proteins; Horseshoe Crabs; Humans; Liver Neoplasms; Peptides, Cyclic; Proliferating Cell Nuclear Antigen; Tumor Cells, Cultured