[Expression of IGF-I and IGF-IR in bladder cancer].
OBJECTIVE
Insulin-like growth factors (IGF) is one of polypeptide growth factors that stimulate proliferation, survival, and differentiation in many cell types; their signal pathways implicate development and progression of many kinds of malignant tumor, while less study were undergone on the roles of IGF-I and IGF-IR in bladder cancer genesis. This study was designed to investigate the expression of IGF-I and IGF-IR and proliferation cell nuclear antigen (PCNA) in human normal and carcinomatous bladder cancer, and to explore the mechanism of IGF-I and IGF-IR in cellular proliferation and tumorigenesis of bladder cancer.


METHODS
Immunohistochemical methods were adopted to examine expression of IGF-I, IGF-IR, and PCNA in 88 cases with bladder cancer and 12 cases with normal bladder tissues. The relationship of expression of IGF-I and IGF-IR with various clinicopathological parameters and PCNA were analyzed.


RESULTS
The protein expression rates of IGF-I and IGF-IR in bladder cancer were 73.9% and 59.1%, significantly higher than 33.3% and 16.7% in normal tissues, respectively(P< 0.05). Both two protein expression were association with PCNA indexes in bladder cancer (P< 0.05). There were close relationship among IGF-I expression and tumor recurrence (P< 0.05), IGF-IR and tumor grade, stage and recurrence (P< 0.05).


CONCLUSIONS
Abnormality of IGF-I-IGF-IR autocrine loop play an important role in development and progression of bladder cancer by promoting abnormal cellular proliferation. IGF-IR may be a marker for evaluating tumor biological behaviors.
Xie
Qing-Xiang
QX
Department of Urology, The 175th Hospital of PLA, Zhangzhou, Fujian, PR China. xieqx@sohu.com
Lin
Xia-Cong
XC
Zhang
Min-Feng
MF
Han
Cong-Xiang
CX
Guo
Yi-He
YH
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000378:metabolism*; D001749:Urinary Bladder Neoplasms / Q000378:metabolism* / Q000473:pathology
D018809:Proliferating Cell Nuclear Antigen; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1