| Objectives To establish the transplanted tumor models of human lung squamous cell carcinoma in nude mice, and to investigate the differential micro RNA expression profiles between human lung squamous tumors that were subcutaneously implanted into nude mice could form xenograft tumors and couldn’t form xenograft tumors by the method of mi RNA microarray chip and the effect of mi R-223-3p on the function of human lung squamous cancer cells.Methods Lung squamous cancer tissues were collected from 21 patients who underwent surgical resections at the department of thoracic surgery of Anhui Provincal hospital from August 2013 to January 2014. Lung carcinoma tissues were subcutaneously implanted into nude mice within 1 hour after surgical resections. The tumorigenicity of transplanted tumors was observed, and the characteristics for tumors that could form xenograft tumor(XG) and could not form xenograft(no-XG) were compared retrospectively. Expression of p63, cytokeratin5/6(CK5/6), thyoid transcription factor-1(TTF-1) and Ki67 were detected by immunohistochemistry, and the expression level of Ki67 was further semi-quantitatively analyzed by H-score. To establish the significant differential micro RNA expression profile between XG and no-XG by microarray chip method.The result of microarray chip was verified by quantitative real-time PCR analysis. The expression level of mi R-223-3p between lung squamous cancer and adjacent normal lung tissue was detected by q RT-PCR. The biological effects of the mi R-223-3p on the cell cycle distribution, apoptosis and proliferation of SK-MES-1 cells were detected by flow cytometric assay and MTT assay, respectively.Results 12 xenografts(57.1%) were established from total 21 implanted lung squamous carcinomas. The tumorigenicity of lung squamous cell carcinoma was correlated with differentiation(Z=-2.821, P=0.005)and tumor size(Z=-2.809, P=0.005). High homogeneity was found between xenograft tumors and human lung cancers in expressions of p63, CK5/6, TTF-1and Ki-67. The average H-score of the expression level of Ki67 in XG group was 2.76±0.54, which significantly higher than that in no-XG group(1.37±0.77)(t=4.855, P=0.001). Compared with no-XG group, 11 mi RNAs were significantly up-regulated and 27 mi RNAs were down-regulated in XG group. Both mi RNA microarray and q RT-PCR showed that the expression of mi R-451 a and mi R-223-3p was down-regulated in XG group. Moreover, compared with the corresponding adjacent normal lung tissues, mi R-223-3p expression was down-regulated in lung cancer tissues, and was significantly lower in XG group. Mi R-223-3p mimics inhibited the proliferation of lung cancer SK-MES-1 cells, and the ratio of early apoptotic cells and S Phase cells were increased.Conclusions The xenotransplantation model for patient-derived lung squamous cell carcinoma in nude mice were successfully established. The tumorigenesis maybe correlated with the expression level of Ki67 in lung squamous carcinoma. This xenotransplantation model retained the basic biological characteristics of human lung squamous cell cancer, suggesting that it may provide a perfect platform for the research on human lung squamous cell carcinoma. Moreover, Significantly differentially expressed micro RNAs between XG group and no-XG group were obtained using microarray. The expression level of mi R-223-3p was down-regulated in human lung squamous cancer tissues, and was significantly lower in XG group than no-XG group. Over expression of mi R-223-3p in SK-MES-1 could suppress the abilities of proliferation and induce apoptosis and S Phase arrest. |
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