Over expression of integrin alpha 5 beta 1 in human hepatocellular carcinoma cell line suppresses cell proliferation in vitro and tumorigenicity in nude mice.
Integrin alpha 5 beta 1 and alpha 2 beta 1 are the major integrin receptors in human hepatocytes. However, in human hepatocellular carcinoma cells it was found that the expression of integrin alpha 5 beta 1 was decreased and another integrin alpha 6 beta 1 increased. In this study, the SMMC7721 human hepatocellular carcinoma cells cotransfected or singly transfected with integrin alpha 5 and/or beta 1 cDNAs were established, and designated alpha 5 beta 1.6-7721, alpha 5.3-7721, and beta 1.6-7721 cell lines, respectively. Transfection with cDNAs of integrin alpha 5 and beta 1 subunits resulted in the over expression of each integrin and modified biological properties, including a slowed growth rate, changes in the cell cycle from 15.5% of control cells in the G2/M phase to 12.1%, 9.6% and 9.4% in alpha 5.3-7721, beta 1.6-7721, alpha 5 beta 1.6-7721, respectively, and a decrease in the Cell Mitosis Index from 1.6 in controls to 0.96, 0.95, and 0.72, and 34%, 28% and 52% derived from colony forming ability, respectively. Tumorigenicity was also tested in nude mice with inoculation of cells subcutaneously. Tumor masses growing in nude mice following inoculation with beta 1.6-7721, and alpha 5 beta 1.6-7721 cells weighed only 52% or 31% those of control cells. These results indicated that deletion or low expression of integrin alpha 5 beta 1 may play an important role in the development of hepatocellular carcinoma. Therefore, induction of expression of the integrin alpha 5 beta 1 in malignant cells could be a potential means of treating hepatocellular carcinoma.
Zhou
G F
GF
Key Laboratory of Glycoconjugate Research, Ministry of Health, Department of Biochemistry, Shanghai Medical University, China.
Ye
F
F
Cao
L H
LH
Zha
X L
XL
D000818:Animals; D015197:Carcinogenicity Tests; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle; D002455:Cell Division; D003114:Colony-Forming Units Assay / Q000379:methods; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007279:Injections, Subcutaneous; D008113:Liver Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D017469:Receptors, Fibronectin / Q000096:biosynthesis / Q000235:genetics*; D014162:Transfection
D017469:Receptors, Fibronectin