The effects of p38MAPK and HBxAg on cell proliferation and apoptosis in human hepatocarcinogenesis / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effects of host-derived p38 mitogen-activated protein kinase subunit 38 (p38MAPK) and the hepatitis B virus X antigen (HbxAg) on cell proliferation and apoptosis in human hepatocellular carcinoma (HCC), and to study the mechanism underlying hepatocarcinogenesis.</p><p><b>METHODS</b>Liver tissues were biopsied from healthy individuals and patients with chronic hepatitis B (CHB), liver cirrhosis, paratumor cirrhosis, and HCC. Immunohistochemical staining was used to detect expressions of HBxAg, p38MAPK, cell cycle G2/M phase-related factors (cdc25B, p34cdc2, cyclin B1), and cell proliferation factor ki-67.The terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling method (known as TUNEL) was used to detect apoptosis.</p><p><b>RESULTS</b>The highest rates of HBxAg were detected in CHB (65.0%) and HCC (44.4%) liver samples, and the antigen was mainly expressed in nuclei. Increasingly higher rates of p38MAPK, cdc25B, cyclin B1, and p34cdc2 expression were detected with increases in disease severity: normal liver (40.0%, 20.0%, 20.0%, and 30.0%, respectively), chronic hepatitis B (60.0%, 65.0%, 40.0%, and 50.0%, respectively), liver cirrhosis (65.0%, 75.0%, 70.0%, and 55.0%, respectively), paratumor cirrhosis (66.7%, 75.0%, 75.0%, and 63.9%, respectively), and HCC (77.8%, 80.6%, 80.6%, and 72.2%, respectively). In addition, the intracellular location of p38MAPK expression was different under different disease conditions, showing nuclear expression in CHB and liver cirrhosis samples and cytoplasmic expression in paratumor cirrhosis and HCC samples (x2 = 1.11, P more than 0.05). The proliferation index (PI) and the apoptosis index (AI) were both increased along with disease severity (normal more than CHB more than paratumor cirrhosis more than HCC) (PI: 0.0000+/-0.000, 0.0502+/-0.011, 0.0411+/-0.009, 0.0762+/-0.017; AI: 0.0351+/-0.024, 0.0607+/-0.022, 0.0562+/-0.013, 0.0716+/-0.011), with the notable exception for liver cirrhosis (PI: 0.1810+/-0.036 and AI: 0.1200+/-0.018). PI in poorly-differentiated HCC (0.2285+/-0.062) was significantly higher than in well-differentiated HCC (0.1216+/-0.032, t = 2.082, P = 0.044). AI in well-differentiated HCC (0.152+/-0.026) was significantly higher than in poorly-differentiated HCC (0.081+/-0.022, t = 2.129, P = 0.041).</p><p><b>CONCLUSIONS</b>In the process of hepatocarcinogenesis, HBxAg may cause a series of abnormal changes in cell cycle, proliferation and apoptosis by affecting the expression of p38MAPK.</p>

Role of p38MAPK in apoptosis of human paratumor cirrhosis hepatocellular cell line QSG-7701 induced by cisplatin / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the roles of p38 MAPK in apoptosis of the normal liver cell, the paratumor cirrhosis hepatocellular cell and the hepatocellular carcinoma cell.</p><p><b>METHODS</b>Three cell lines were adopted (the normal liver cell line HL-7702, the paratumor cirrhosis hepatocellular cell line QSG-7701 and the hepatocellular carcinoma cell line QGY-7703) and treated with Diamminedichloroplatin (DDP, cisplatin) and p38MAPK inhibitor SB203580. The apoptosis and cell cycles were detected by flow cytometry and electromicroscopy. The expressions of p38MAPK, CDC25B, p34cdc2 and cyclinB1 were detected by immunocytochemical staining , confocal microscopy and western blot.</p><p><b>RESULTS</b>The apoptotic rates in all three cell lines pretreated with DDP increased obviously and the rates in normal liver cells and HCC cells increased continuously even after SB203580 treatment, whereas in paratumor cirrhosis cells the rate decreased and the cell cycle stopped at S phase.</p><p><b>CONCLUSION</b>Cisplatin induces apoptosis in the paratumor cirrhosis hepatocellular cell line QSG-7701 via activation of p38MAPK pathway and it differs in the normal liver cells from the hepatocellular carcinoma cells.</p>