Expression of the G1-S Modulators in Hepatitis B Virus-Related Hepatocellular Carcinoma and Dysplastic Nodule: Association of Cyclin D1 and p53 Proteins with the Progression of Hepatocellular Carcinoma

Deranged expression of cell cycle modulators has been reported to contribute to the development and progression of hepatocellular carcinoma (HCC). However, their expression patterns remain poorly understood in hepatitis B virus (HBV)-related HCC, which constitutes about 65-70% of HCC in Korea. The aims of this study were to evaluate the expressions of G1-S modulators in HBV-related HCCs and dysplastic nodules (DNs), and to correlate with the histopathologic features of HCCs. Immunohistochemical expressions of cyclin D1, cyclin E, p53, p27, p21, p16, Rb, and PCNA proteins were investigated in 80 HCCs and 22 DNs. Cyclin D1 overexpression showed positive relationships with advanced tumor stage, poor differentiation, larger tumor size, microvascular invasion, intrahepatic meta-stasis, no tumor capsule formation, infiltrative growth, aberrant p53 expression, and high PCNA labeling index (LI) of HCC (p<0.05). Aberrant p53 expression showed positive relationship with poor differentiation of HCC (p<0.01). Expression of cyclin D1 or p53 was not observed in DNs. The p27 LI and p16 LI were lower in HCCs with intrahepatic metastasis (p<0.05). Cyclin D1 overexpression and aberrant p53 expression could be associated with the progression of HBV-related HCC, and might have a less crucial role in the DN-HCC sequence. In addition, elevated expression of p27 and p16 proteins might have inhibitory action to the intrahepatic metastasis of HBV-related HCC.

Chronic metabolic acidosis markedly induces proliferation of mesangial cells in rats / 中国病理生理杂志

AIM: To study the effects of chronic metabolic acidosis on glomerulus, mesangial cells and the production of extracellular matrix. METHODS: Chronic metabolic acidosis was induced by addition of 0.28 mol/L NH_4Cl to drinking water for 3, 7, or 14 days in male Wistar rats (n=10). Light microscope combined with computer software (Motic Images Advanced 3.2) was used to determine the effect of chronic acid loading on renal morphologic changes. The expressions of proliferation cell nuclear antigen (PCNA) and p27 in glomeruli were detected by Western blotting or immunohistochemistry. Fibronectin (FN) mRNA was detected by real-time PCR. The proliferation of mesangial cells in vitro was determined by ~3H:-TdR incorporation. The concentration of FN in cultured supernatant was detected by ELISA. RESULTS: On day 1, 3, 7 and 14, the arterial pH and plasma HCO_3~-: in experimental rats were significantly decreased. There was a significantly increased in the kidney weight and the ratio of kidney to body weigh in experimental rats on day 3, 7 and 14. The glomerular area and cell numbers also increased significantly. Immunoblotting demonstrated decreased p27 expression and increased PCNA expression in isolated glomeruli, and the expression of PCNA increased in a time-dependent manner following the time of chronic metabolic acidosis. Immunohistochemistry showed increased positive PCNA expression mainly localized to mesangial cells. The expression of FN mRNA was significantly elevated in experimental rats on day 7 and 14. In vitro, acid loading induced mesangial cell proliferation and synthesis of FN. CONCLUSION: These results suggest that chronic metabolic acidosis induces mesangial cell proliferation, and its mechanism may be associated with the downregulation of cell cycle kinase inhibitor p27.

Research of enalaprilat on neonatal rat cardiac fibroblasts proliferation and its mechanism / 中国药理学通报

Aim To investigate the effects of angiotensin-converting enzyme inhibitor Ena on proliferation and cell cycle protein of cardiac fibroblasts and to explore the mechanism of Ena on cardiac fibrosis.Methods CFb was isolated by trypsin digestion method.MTT colorimetric assay was adopted to evaluate cell proliferation,collagen synthesis was observed by hydroxyproline concentration method,flow cytometry,immunofluorescenic and Western blot was used to measure cell cycle and CKI p27kip1 with Ena.Results Ena decreased MTT value and collagen synthesis dramatically;Ena increased phase G0/G1 and decreased phase S percentage ratio in cell cycle;Ena enhanced p27kip1 protein expression in a dose-dependent manner.Conclusion The antiproliferative effects of Ena on CFb can be attributed to upregulating CKI p27kip1 protein expression.

Caspase-8 dependent osteosarcoma cell apoptosis induced by proteasome inhibitor MG132 / 中国病理生理杂志

AIM: To investigate the effects of proteasome inhibitor Z-LLL-CHO(MG132) on human osteosarcoma cell line MG-63 and its possibly mechanism.METHODS: After treated with different concentration of MG132,the morphological change,ultrastructral morphology,cell viability,cell apoptosis,gene transcription and protein expression in MG-63 cells were accessed by fluorescence microscope,electron microscope,MTT assay,agrose gel electrophoresis,FCM,RT-PCR and Western blotting.RESULTS: Proteasome inhibitor MG132 was an effective inducer of apoptosis in human osteosarcoma MG-63 cells.Not only apoptotic changes,but also cell arrest at G2-M-phase,the accumulation of p27kip1,the accumulation of activated caspase-8 and increased ratio of Bax∶Bcl-2 were observed.However,to normal human diploid fibroblast cells,MG132 did not show apoptosis-inducing effect.CONCLUSION: Apoptosis induced by MG132 may be caspase-8,p27kip1and bcl-2-related.