Objective:To explore the expression of heat shock protein 90β(HSP90β) in colon carcinoma tissues and HCT-8 cell line, and to investigate the relationship of HCT-8 cells to chemoresistance.
Methods:The expression of HSP90 β in colon carcinoma tissues was detected by immunohistochemistry and the relationship of HSP90β expression with the Dukes stage and pathological grade was analyzed, The medium effective concentration (IC50) of vincristine (VCR) to colon cancer parent cells HCT-8 and drug resistance cells HCT-8/VCR was detected by MTT method. The expression difference of HSP90βmRNA in of HCT-8 cells and HCT-8/VCR cells was detected by RT-PCR to investigate its relationship to the chemoresistance.
Results:The positive expression rate of HSP90 β was higher in colon carcinoma tissues (41.67%) than non-cancerous colon tissues (16.67%) (P<0.05). The expression level of HSP90β was related to tumor differentiation grade (r=-0.8825, P<0.05), and was not related to Dukes stage (P>0.05). The drug resistance of HCT-8/VCR cell line to VCR was significantly higher than that of HCT-8 cell line (P<0.05). The content of HSP90βmRNA in drug resistance cells（0.955±0.03）was obviously higher than that in parent cells（0.835±0.029）（P<0.01）.
Conclusions:The expression level of HSP90 β in colon carcinoma is enhanced, which may be related to malignant transformation and chemoresistance,and might serve as a new therapeutic target for improving chemotherapy sensitivity of colon carcinoma.