摘要
Aim： To investigate the expression of cyclooxygenase-2 （COX-2） and epidermal growth factor receptor （EGFR） and the possible mechanism in the development in androgen independent prostate cancer （AIPC）. Methods： Immunohistochemistry was performed on paraffin-embedded sections with goat polyclonal against COX-2 and mouse monoclonal antibody against EGFR in 30 AIPC and 18 androgen dependent prostate cancer （ADPC） specimens. The effect of epidermal growth factor （EGF） treatments on the expression of COX-2 and signal pathway in PC-3 and DU-145 cells was studied using reverse transcription-polymerase chain reaction （RT-PCR） and Western blot analysis. ELISA was used to measure prostaglandin E2 （PGE2） levels in the media of PC-3 and DU-145 incubated with EGF for 24 h. Results： COX-2 was positively expressed in AIPC and ADPC, which were predominantly in endochylema of prostate cancer （PCa） cells. Intense staining was seen in AIPC （80%） and in ADPC （55.5%）, but there was no significant association between the two groups. EGFR expression was also positive in the two groups （61.8% in ADPC and 90% in AIPC, P 〈 0.01）. A significant association was found between EGFR expression and a higher Gleason score （P 〈 0.05） or tumor stage （P 〈 0.05）. The expression of PGE2 was increased in PC-3 and DU-145 cells after being incubated with EGF. Both p38MAPK and PI-3K pathway were involved in the PC-3 cell COX-2 upregulation course. In DU- 145, only p38MAPK pathway was associated with COX-2 upregulation. Conclusion： EGFR activation induces COX-2 expression through PI-3K and/or p38MAPK pathways. COX-2 and EGFR inhibitors might have a cooperative anti-tumor effect in PCa.
Aim： To investigate the expression of cyclooxygenase-2 （COX-2） and epidermal growth factor receptor （EGFR） and the possible mechanism in the development in androgen independent prostate cancer （AIPC）. Methods： Immunohistochemistry was performed on paraffin-embedded sections with goat polyclonal against COX-2 and mouse monoclonal antibody against EGFR in 30 AIPC and 18 androgen dependent prostate cancer （ADPC） specimens. The effect of epidermal growth factor （EGF） treatments on the expression of COX-2 and signal pathway in PC-3 and DU-145 cells was studied using reverse transcription-polymerase chain reaction （RT-PCR） and Western blot analysis. ELISA was used to measure prostaglandin E2 （PGE2） levels in the media of PC-3 and DU-145 incubated with EGF for 24 h. Results： COX-2 was positively expressed in AIPC and ADPC, which were predominantly in endochylema of prostate cancer （PCa） cells. Intense staining was seen in AIPC （80%） and in ADPC （55.5%）, but there was no significant association between the two groups. EGFR expression was also positive in the two groups （61.8% in ADPC and 90% in AIPC, P 〈 0.01）. A significant association was found between EGFR expression and a higher Gleason score （P 〈 0.05） or tumor stage （P 〈 0.05）. The expression of PGE2 was increased in PC-3 and DU-145 cells after being incubated with EGF. Both p38MAPK and PI-3K pathway were involved in the PC-3 cell COX-2 upregulation course. In DU- 145, only p38MAPK pathway was associated with COX-2 upregulation. Conclusion： EGFR activation induces COX-2 expression through PI-3K and/or p38MAPK pathways. COX-2 and EGFR inhibitors might have a cooperative anti-tumor effect in PCa.
