[Correlation of growth hormone receptor expression to preoperative radiosensitivity of rectal cancer patients].
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.


METHODS
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.


RESULTS
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).


CONCLUSIONS
Detection of GHR expression before preoperative irradiation may predict radiosensitivity of rectal cancer.
Wu
Xiao-Yu
XY
Department of General Surgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu, 210002, P. R. China. wuxiaoyu@medmail.com.cn
Xu
Zhe
Z
Chen
Che
C
Liu
Fu-Kun
FK
Li
Jie-Shou
JS
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010315:Particle Accelerators; D011300:Preoperative Care; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011836:Radiation Tolerance; D011882:Radiotherapy, High-Energy; D011986:Receptors, Somatotropin / Q000096:biosynthesis* / Q000235:genetics; D012004:Rectal Neoplasms / Q000378:metabolism* / Q000532:radiotherapy*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012333:RNA, Messenger; D011986:Receptors, Somatotropin