Wu Xiao-Yu, Xu Zhe, Chen Che, Liu Fu-Kun, Li Jie-Shou
Department of General Surgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu, 210002, P. R. China.
Ai Zheng. 2006 Sep;25(9):1162-7.
BACKGROUND & OBJECTIVE: Growth hormone (GH) could activate pathways involved in DNA repair process by binding to growth hormone receptor (GHR), which is thought as one of the mechanisms of radioprotection. This study was to evaluate the correlation of GHR expression to radiosensitivity of rectal cancer.
The expression of GHR in biopsy specimens from 98 rectal cancer patients before preoperative irradiation and postoperative specimens was detected by immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR). Radiosensitivity was evaluated according to Rectal Cancer Regression Grading.
IHC revealed that GHR overexpression was positively correlated to poor response to radiotherapy (P<0.001, rs=0.399); RT-PCR also showed that radiosensitivity was significantly higher in GHR mRNA-negative group than in GHR mRNA-positive group (P<0.001, rs=0.398). Compared with the biopsy specimens before preoperative irradiation, the paired postoperative specimens showed significantly increased GHR expression in residual cancer cells (P<0.001).
Detection of GHR expression before preoperative irradiation may predict radiosensitivity of rectal cancer.
生长激素（GH）可通过与生长激素受体（GHR）结合激活参与DNA修复过程的信号通路，这被认为是放射防护机制之一。本研究旨在评估GHR表达与直肠癌放射敏感性的相关性。
采用免疫组织化学（IHC）和逆转录聚合酶链反应（RT-PCR）检测98例直肠癌患者术前放疗前活检标本及术后标本中GHR的表达。根据直肠癌退缩分级评估放射敏感性。
免疫组织化学显示GHR过表达与放疗反应差呈正相关（P<0.001，rs=0.399）；RT-PCR也显示GHR mRNA阴性组的放射敏感性显著高于GHR mRNA阳性组（P<0.001，rs=0.398）。与术前放疗前的活检标本相比，配对的术后标本显示残留癌细胞中GHR表达显著增加（P<0.001）。
术前放疗前检测GHR表达可预测直肠癌的放射敏感性。
