Quantitative RT-PCR analysis demonstrates that synthesis of the recombinant fibrinogen is dependent on the transcription and synthesis of gamma-chain

Proapoptotic function of integrin beta(3) in human hepatocellular carcinoma cells

PURPOSE

This study evaluates the proapoptotic function of integrin beta(3) in human hepatocellular carcinoma (HCC).

EXPERIMENTAL DESIGN

The expression of integrin beta(3) in 67 HCC specimens paired with corresponding neighboring nontumorous tissue was studied by quantitative real-time PCR and Western blot. The proapoptotic function of integrin beta(3) in SMMC-7721 human hepatoma cells overexpressing ITGB3 (gene coding integrin beta(3)) was determined through colony formation, serum starvation, and anoikis assay.

RESULTS

Compared with neighboring pathologically normal liver tissue, approximately 60% of the HCC specimens showed a significant down-regulated level of integrin beta(3) expression. Transient expression of integrin beta(3) in SMMC-7721 resulted in an enhanced level of apoptosis and suppression of colony formation. Cell growth inhibition on serum/ligand deprivation and incidences of anoikis were remarkably increased in SMMC-7721 with stable expression of integrin beta(3) in comparison with vector control transfectants. In addition, expression of fibrinogen and vitronectin, two native ligands for integrin alpha(v)beta(3) in liver, was inhibited, which was correlated with the decreased integrin beta(3) expression. Replenishing these ligands to the starved SMMC-7721 stable transfectants effectively restored the proapoptotic function of integrin beta(3).

CONCLUSIONS

Down-regulation of integrin beta(3) and its ligands in liver is related to the aggressive growth of HCC. Thus, reconstitution of integrin beta(3) in HCC may be a potential therapeutic approach to inhibit aggressive growth of liver cancer.

Increase in hepatic mRNA expression of coagulant factors in type 2 diabetic model mice

AIM

The purpose of the study is to investigate whether hypercoagulation in diabetes is observed not only in increased plasma levels of the coagulative factors but also in increased hepatic mRNA levels.

MATERIALS AND METHODS

The age-related changes of coagulation factors were determined using KK and KK-A(y) mice as a model for human type 2 diabetes mellitus. Expression of the alpha-, beta- and gamma-chains of fibrinogen-mRNA and prothrombin-mRNA from the mouse liver was examined by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Hemoglobin A(1c) (HbA(1C)), plasma fibrinogen, triglyceride and insulin levels increased apparently, especially in KK-A(y) mouse at 4 months old. The mRNA levels of gamma-chain of fibrinogen significantly increased at 3 and 4 months of age in both mice. The mRNA levels of alpha- and beta-chains of fibrinogen and prothrombin were significantly increased in 4-month-old KK-A(y) mouse.

CONCLUSIONS

These results suggest that the increase in hepatic mRNA expression of coagulant factors contributes to the hypercoagulable state in type 2 diabetic mice.