Objective To review the relationship between the expression levels of bcl-2, bax and bad gene and other biological factors of breast cancer in the growth and development of breast cancer. Methods Related literatures were summarized and reviewed. Results The expression level change of antiapoptosis gene bcl-2 was still under research and the expression levels of apoptosis gene bax and bad were down-regulated progressively in the evolution from benign breast tissue to breast cancer tissue. The expression level of bcl-2 had positive correlation with some positive factors in breast cancer such as estrogen receptor （ER） and progesterone receptor (PR), while it had negative correlation with some negative factors such as p53, EGFR, c-erbB-2 and lymph node metastasis. The levels of ER, PR and the expression level of p53 of breast cancer had no relationship with the expression level of bax. Up to now there was no report about the relationship between the expression level of bad and other biological factors of breast cancer. Conclusion The role of altered expression level of bcl-2, in the treatment and prognosis of breast cancer is still controversial, and the relationship between the expression of bad and the prognosis of breast cancer is still unknown, but expression level of bax is correlated positively with the prognosis of breast cancer. Research on these genes can provide us some new index to evaluate the prognosis of breast cancer and new ideas on treatment of breast cancer including gene therapy.
Objective To study the inhibitory effect of RNA interference (RNAi) on bcl-2 expression of vascular smooth muscle cells （VSMCs) in rabbit. Methods The expression vector of bcl-2 gene-targeting small interference RNA (pshRNA-bcl-2) was constructed and was transfected into VSMCs by lipofectamine, and the unloaded vector was used as control. The expression of bcl-2 mRNA was identified by RT-PCR and Western blot, respectively. The growth of the transfected VSMCs was examined by MTT. Results The pshRNA-bcl-2 may inhibit the expression of bcl-2 gene at the levels of transcription and translation. There were significant differences (P＜0.01) of the expressions of bcl-2 mRNA between the VSMCs that were transfected with pshRNA-bcl-2 and the ones in plasmid transfected group and control group, respectively. There was a significant difference (P＜0.01) in the growth of VSMCs between the plasmid transfected and the control groups. Conclusion The plasmid containing the small interference RNA of bcl-2 may have an inhibitory effect on the cell growth and endogenous expression of bcl-2 gene at the levels of transcription and translation in VSMCs.
To elucidate bcl-2 protein expression in hepatic carcinogenetic process and its relationship with apoptotic changes. bcl-2 protein was evaluated immunohistochemically while apoptosis was approached with terminal deoxynucleotidyl transferase (TdT)mediated dUTP nick end labeling (TUNEL) technique in 8 normal livers (NL), 17 liver cirrhosises (LC) and 77 hepatocellular carcinomas (HCC). The results showed that bcl-2 protein was expressed in 3 of 8 NLs(37.5%), 5 of 17 LCs(29.4%) and 7 of 77 HCCs(9.1%) with significant differences between group NL and HCC and between LC and HCC (Ｐ＜0.05). Apoptosis rates of 1.18±0.42%, 4.85±2.78%, 12.89±2.33% in NL, LC, HCC group respectively were demonstrated with significant differences among them (Ｐ＜0.01). Compared the bcl-2 expression with the apoptosis rate in this hepatocarcinogenetic process, reversed trends were presented. Conclusion: bcl-2 expression could be detected in NL, LC and HCC, and its decreasing expression was related to the inhibition attenuation of hepatocellular apoptosis in the process of hepatocarcinogenesis.
Objective To probe into the roles of inositol 1, 4, 5-trisphosphate (IP3) and bcl-2 gene expression in inhabiting hepatocellular carcinoma of nude mice by quercetin. Methods Animals with hepatocellular carcinoma in quercetin group were treated with injection peritoneum of quercetin 50 mg/（kg·d ） for 3 weeks, while which in control group were treated with 0.4% DMSO of RPMI 1640 0.05 ml/（g·d）. Then the volume and the weight of tumors were measured, IP3, bcl-2 mRNA and bcl-2 protein were assayed by IP3-［3H］ Birtrak Assay, RT-PCR and Western blot respectively. Results The volume and weight of tumors in quercetin group were lower than those in control group 〔（15.8±10.1） mm3 vs. （52.3±26.5） mm3 in volume, （44.8±10.4） mg vs.（91.3±31.4） mg in weight， P＜0.01〕. Content of IP3 in quercetin group was lower than that in control group 〔（13.4±1.4） pmol/mg prot vs. （35.3±6.6） pmol/mg prot， P＜0.01〕. There was no significant difference in bcl-2 mRNA expression between quercetin group and control group 〔RI （the gray degree multiply area of bcl-2 /the gray degree multiply area of β-actin）： 0.55±0.05 vs. 0.79±0.19， P＞0.05〕， but the expression of bcl-2 protein in quercetin group was lower than that in control group (RI: 1.07±0.12 vs. 6.69±1.80, P＜0.01). Conclusion Quercetin can inhabit the growth of hepatocellular carcinoma tansplanted into liver of nude mice by reducing IP3 production and down-regulating bcl-2 gene expression.
【Abstract】ObjectiveTo investigate the proliferation rate of HepG2 cell after multiple thermotherapy and the possible reasons related to it. MethodsAfter HepG2 cell were treaded by ten repeated cycles of heat exposure at 43 ℃ for 80 minutes twice a day, the doubling time of cell was analyzed， and the cell cycle, bcl2 mRNA and bax mRNA were detected. ResultsThe proliferation rate of HepG2 cell which treated with heat speeded up, the percentage of G2 and S in cell cycle increased, the expression of bcl2 mRNA strengthened and the rate of bcl2/bax increased. ConclusionThe speeded proliferation of HepG2 cell after multiple thermotherapy is related to its high percentage of DNA duplicated and dividing cell, strengthened expression of bcl2 mRNA and increased rate of bcl2/bax.