RNA干扰下调不同肿瘤细胞表皮生长因子受体表达及其意义

背景与目的：表皮生长因子受体在多种上皮源性肿瘤中过表达，与肿瘤的发生、发展密切相关，是肿瘤治疗的重要靶点。本研究采用针对EGFR的小干扰RNA（siRNA），探讨其在不同类型肿瘤细胞A431、HeLa、SPC-A-1中的RNA干扰效应。方法：化学合成针对EGFR的siRNA，转染A431、HeLa、SPC—A-1细胞，通过定量RT-PCR、免疫荧光染色和流式细胞仪检测EGFR表达；通过集落形成实验观察细胞集落形成能力，分析不同类型肿瘤细胞的RNA干扰效应。结果：转染siRNA-EGFR后，3种肿瘤细胞的EGFR表达均明显下调。在A431细胞，其mRNA水平下调73．9％，蛋白水平下调77．0％。在HeLa和SPC-A-1细胞，mRNA水平的下调分别为44．6％和57．7％。蛋白水平下调61．3％和65．2％。EGFR下调后细胞集落形成能力均出现抑制，A431、HeLa和SPC-A-1的集落形成抑制率分别为27．2％、53．9％和59．1％。结论：siRNA-EGFR可在不同类型肿瘤细胞中产生RNA干扰效应。抑制细胞集落形成能力。RNA干扰技术在开发广谱抗肿瘤靶向治疗药物中具有应用价值。

RNA interference mediated inhibition of epidermal growth factor receptor expression and its significance in different human cancer cell lines

Background and purpose:The epidermal growth factor receptor (EGFR) is commonly overexpressed in a variety of solid tumors, and has important roles in cancer pathogenesis and progression. EGFR thus provides a rational target for cancer therapy. We studied siRNA-mediated inhibition of epidermal growth factor receptor expression and its biologic effects in different human cancer cell lines (A431, HeLa and SPC-A-1). Methods:Cells were transfected with chemically synthesized siRNA-EGFR. EGFR mRNA was quantified by real-time PCR and was detected by immunofluorescence staining and flow cytometry. The biologic effects on cell growth were assessed by colony-formation assay.Results:siRNA-EGFR significantly decreased mRNA level of EGFR by 73.9 %, 44.6 % and 57.7 %, protein expression of EGFR by 77.0 %, 61.3 % and 65.2 %, and reduced colony number by 27.2 %, 53.9 % and 59.1 % in A431, HeLa and SPC-A-1, respectively.Conclusions:Our data suggested that RNA interference could downregulate EGFR and inhibit colony forming ability and EGFR expression at mRNA/protein levels in human cancer cell lines with different pathological types. siRNA could be one of the promising strategies in future targeted cancer therapy.