ABSTRACT
Objective To detect the expression of HER2 in clinical colon carcinoma tissue ,to investigate its correlation with the clinicopathological characteristics and to analyze its influence on the proliferation and cell cycle in colon carcinoma cell lines .Methods 108 specimens of colon carcinoma and corresponding paracancerous tissues were collected .The hybridization in situ and real-time quantitative polymerase chain reaction were used to detect the HER 2 expression in those specimens .The relationship between HER2 expression and the clinicopathologic features was analyzed .The expression of HER2 in colon carcinoma cells(SW480 and Lo-Vo) was reduced by using the antisense technology .The MTT assay and the flow cytometry were used to investigate the HER2 in-fluences on the cell proliferation and cell cycles .Results The hybridization in situ results showed that the HER2 positive expres-sion rate was 66 .67% in colon carcinoma and 10 .19% in the paracancerous tissues ,the difference between them was statistically significant(P<0 .05) .The real-time fluorescent quantitative PCR results further showed that HER2 was found to be overexpressed in 61 .11% of the colon carcinoma tissue(P<0 .05);the expression of HER2 was gradually increased with the progress of colon cancer .(P<0 .05);the expression of HER2 in the colon tissue with lymph node metastasis was also significantly higher than that without lymph node metastasis in colon carcinoma (P<0 .05);siRNA-HER2 could significantly reduce the expression of HER2 in colon cancer cell lines(SW480 and LoVo) ,the growth of colon carcinoma cell lines was also significantly inhibited and the propor-tion of cells in G0/G1 phase was increased ,while the proportion of cells in S phase and G2/M phase was decreased .Conclusion HER2 is closely related with the occurrence and development of colon carcinoma ,its mechanism could regulate the grow th of colon carcinoma cells via mediating the transition of G1/S phase ,which may provide a new target for the treatment of colon carcinoma .
ABSTRACT
Background and purpose: The miR-224 in a variety of malignant tumors is overexpression, however, its expression and function in colon cancer are not clear. The aim of this study was to investigate the expression of miR-301 in colon cancer tissues and demonstrate the regulative effects of miR-301 ASO on the proliferation and apoptosis of colon cancer cell in vitro and in vitro. Methods:The expression of miR-301 in 120 colon cancer tissues and their adjacent tissues was detected by real-time quantitative PCR method. After transfection with miR-301ASO, the biological effects of miR-301 in SW620 cells were measured by MTT assay, the colony formation experiment, flow cytometry and the in vivo experiment. Results: The expression level of miR-301 was found to be overexpressed in 63.33% (76/120) of the colon cancer cases (P<0.05). miR-301 expression in SW620 cells (transfection with miR-301 ASO, 0.09±0.01) was significantly less than control group (0.50±0.07, P=0.00). MTT assay results showed that SW620 cells survived rate at 24, 48 and 96 h decreased greatly after transfection with miR-301ASO (P=0.00). Clone formation assay revealed that miR-301 ASO group colony formation rate (5.33%±0.74%) was significantly lower than the control group (33.33%±8.38%, P=0.00). In vivo study further confirmed that miR-301ASO could inhibit the proliferation of SW620 cells (P<0.05), and miR-301ASO group grew substantially slow compared with the negative control group (P=0.00). Flow cytometry indicated that the apoptotic index in miR-301 ASO group (15.68±1.46) was significantly higher than the control group (3.36±0.88, P=0.02). In addition, the Bcl2 mRNA and protein were significantly decreased after reduce the expression of miR-301 (P=0.00, P=0.00). Conclusion:MiR-301 was overexpressed in human colon cancer. Reduce the expression of miR-301 can effectively inhibit the growth of colon cancer cells and promote apoptosis. MiR-301 may become a new target for the regulation of gene expression in colon cancer.