The expression of B-cell translocation gene 2 in diethylnitrosamine-induced primary hepatocellular carcinoma rat model / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the expression and role of B-cell translocation gene 2(BTG2) in the carcinogenesis of hepatocellular carcinoma (HCC).</p><p><b>METHODS</b>Modified Diethylnitrosamine (DEN)-induced primary hepatocellular carcinoma rat model was established. The expression of BTG2, p53 and cyclinD1 was detected by RT-PCR, western blot and immunohistochemistry.</p><p><b>RESULTS</b>The BTG2 protein was predominantly localized in the nucleus, with faint cytoplasmic staining in normal liver cells; however, it is mainly a cytoplasmic protein in HCC cells. BTG2 was over-expressed during the early stage after DEN treatment, the expression level peaked at 5 weeks and then it gradually decreased to the normal level after 16 weeks. The expression of cyclin D1 and cyclin E was increased gradually after DEN treatment, and peaked at 16 weeks and 5 weeks respectively. A significant increase in p53 was not observed until 5 weeks after DEN treatment, and it gradually decreased after 16 weeks.</p><p><b>CONCLUSIONS</b>Decreased expression of BTG2 may be an important step in carcinogenesis of HCC. BTG2 may positively regulate p53 expression and negatively regulate cyclin D1 expression in the carcinogenesis of HCC.</p>

The expression of Tec and the level of its phosphorylation in primary hepatic carcinomas / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To detect the expressions of Tec tyrosine kinase in hepatocellular carcinoma and the levels of phosphorylation of tyrosine kinase in liver cancer tissues, paracancerous tissues and normal liver tissues and to find the significance of their differences.</p><p><b>METHODS</b>200 specimens of tissues, including liver cancer tissues, surrounding liver tissues not more than 1.5 cm from the cancers, and normal liver tissues were investigated for Tec protein expression and Tec phosphorylation by tissue microarrays and immunohistochemistry (SP method).</p><p><b>RESULTS</b>The positive immunohistochemical stainings of Tec in cancerous tissues and non-cancerous tissues showed no obvious differences, nevertheless, the immunostaining levels in liver cancer tissues were much higher than in non-cancerous tissues and they correlated with the grading of tumors (P < 0.05). The phosphorylation of Tec was significantly expressed in liver cancer tissues (73%) in comparison with other tissues (42%, 10% both P < 0.05), but it did not correlate with any clinicopathological characteristics.</p><p><b>CONCLUSION</b>Overexpression of Tec is associated with the tumorigenesis and development of liver cancer; inhibiting Tec or degrading Tec phosphorylation directly might affect the progression of liver cancer.</p>

The expression of platelet-derived growth factor-A and its receptor in acute radiation-induced skin ulcer in rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the dynamic expression of platelet-derived growth factor-A (PDGF-A) and its receptor alpha (PDGFR-alpha) in different acute radiation-induced skin ulcers, and to explore the underlying mechanism involved in retarded healing of the ulcer.</p><p><b>METHODS</b>The model of acute radiation-induced skin ulcers in rats was replicated with 50 Gy 60Co gamma rays to the skin (radiation group, R, n = 55), rats with full - thickness skin excision wounds as control group (T, n = 55), and 5 normal rats to serve as normal control (NC) group. The expression of PDGF-A and PDGFR-alpha protein and PDGF-A mRNA was respectively assessed by means of histochemistry and in situ RT-PCR.</p><p><b>RESULTS</b>No PDGF-A expression was identified in the rat skin in NC group. The expression of PDGF-A and PDGFR were reduced in R group during inflammatory responsive and granulation formation periods (14 - 28 days after radiation, the IA value of PDGF-A varied from 14.0 +/- 1.2 to 20.3 +/- 1.2 compared with that in T group in which the IA value of PDGF-A at the same period (3 - 9 days after injury) varied from 20.0 +/- 1.6 to 28.3 +/- 1.0, and reduced gradually during scar formation period (55 days after radiation).</p><p><b>CONCLUSION</b>The reduction of PDGF-A and PDGFR-expression may be partially involved in the mechanism of retarded healing of acute radiation-induced skin ulcers.</p>

Effect of lovastatin on the expression of IkappaBalpha and cell-cycle regulating protein in MCF-7 cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the effect of lovastatin on the expression of IkappaBalpha and cell-cycle regulating proteins in MCF-7 cells.</p><p><b>METHODS</b>MCF-7 cells were treated with 4, 8 and 16 micro mol/L lovastatin for 48 - 72 h. The distribution of cell cycles was assayed by flow cytometry (FCM). The protein expression of IkappaBalpha, CDK4, p16, pRb in cytoplasm and IkappaBalpha in the nucleus were detected by Western blot.</p><p><b>RESULTS</b>Lovastatin could arrest cellcycle in the G(0)/G(1) phase in a dose- and time-dependent manner, obviously lowering the expression of IkappaBalpha, CDK4 and pRb protein level in the cytoplasm and increasing IkappaBalpha in the nucleus, but not on p16 protein level.</p><p><b>CONCLUSION</b>Lovastatin can induce the arrest of cell cycle in G(0)/G(1) phase by affecting the expression of IkappaBalpha and cell-cycle regulating protein in MCF-7 cells.</p>