胰岛素样生长因子1受体高表达提示直肠癌放射治疗耐受

Insulin-Like Growth Factor-1 Receptor Overexpression in Pretreatment Biopsies Predicts Response of Rectal Cancer to Preoperative Radiotherapy

目的研究胰岛素样生长因子1受体(IGF-1R)表达水平与直肠癌放射治疗(简称放疗)敏感性的关系。方法选择江苏省中医院消化肿瘤外科2009年1月至2010年12月期间的87例直肠癌患者,应用免疫组织化学和逆转录聚合酶链反应(RT-PCR)方法检测直肠癌放疗前活检标本及相应的术后标本中IGF-1R蛋白和mRNA的表达;放疗敏感性评分参照直肠癌消退分级(RCRG)。结果与放疗前活检标本相比,配对的放疗后标本中残留的直肠癌肿瘤细胞中IGF-1R表达水平明显升高(P<0.001)。放疗前直肠癌活检标本中IGF-1R蛋白强表达与放疗耐受有显著相关性(rs=0.401,P<0.001);RT-PCR结果同样显示,IGF-1RmRNA阴性表达者具有更高的放疗敏感性(rs=0.497,P<0.001)。结论直肠癌IGF-1R高表达提示患者术前放疗耐受。

Objective To evaluate the possible role of the expression of insulin-like growth factor-1 receptor（IGF-1R） in determining rectal cancer radiosensitivity. Methods The paired preradiation biopsy specimens and postoperative specimens were obtained from 87 patients with rectal cancer in the department of digestive tumor surgery,Jiangsu Province Hospital of Traditional Chinese Medicine,Affiliated Hospital of Nanjing University of Traditional Chinese Medicine from January 2009 to December 2010.The IGF-1R expression was examined by immunohistochemistry（IHC） and reverse transcription-polymerase chain reaction（RT-PCR）.The tumor radiosensitivity was defined according to Rectal Cancer Regression Grade,then the relation between the IGF-1R expression and tumor radiosensitivity was evaluated. Results Compared with the preradiation biopsy specimens,IGF-1R expression significantly increased in the paired postoperative specimens of the residual cancer cells（P0.001）.The IHC result demonstrated IGF-1R overexpression was significantly associated with a poor response to radiotherapy（rs=0.401,P0.001）;RT-PCR detection of IGF-1R expression on preradiation biopsy specimens also showed that IGF-1R mRNA negative patients had a higher radiation sensitivity（rs=0.497,P0.001）. Conclusion Detection of IGF-1R expression may predict radiosensitivity of preoperative irradiation for rectal cancer.