Effects of tachyplesin on proliferation and differentiation of human hepatocellular carcinoma SMMC-7721 cells.
OBJECTIVE
To investigate the antitumor activities of tachyplesin on human hepatocellular carcinoma (HCC) cells.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Ouyang
Gao-Liang
GL
Laboratory of Cell Biology, School of Life Sciences, Xiamen University, Fuijan Province, China.
Li
Qi-Fu
QF
Peng
Xuan-Xian
XX
Liu
Qing-Rong
QR
Hong
Shui-Gen
SG
D000818:Animals; D023181:Antimicrobial Cationic Peptides; D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D006737:Horseshoe Crabs; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008854:Microscopy, Electron; D010456:Peptides, Cyclic / Q000302:isolation & purification / Q000494:pharmacology*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014444:Tyrosine Transaminase / Q000378:metabolism; D000509:alpha-Fetoproteins / Q000378:metabolism; D005723:gamma-Glutamyltransferase / Q000378:metabolism
D023181:Antimicrobial Cationic Peptides; D000970:Antineoplastic Agents; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004268:DNA-Binding Proteins; D010456:Peptides, Cyclic; D018809:Proliferating Cell Nuclear Antigen; D016271:Proto-Oncogene Proteins c-myc; D000509:alpha-Fetoproteins; C057636:tachyplesin peptide, Tachypleus tridentatus; D005723:gamma-Glutamyltransferase; D014444:Tyrosine Transaminase