A comparison of the effects of Angiotensin IV on androgen-dependent and androgen-independent prostate cancer cell lines

Abstract

Angiotensin IV is one of the biologically active peptides of the renin-angiotensin system. Limited data suggests that this hexapeptide could contribute to cancer development and/or progression. Using the MTT reduction assay as an indicator of cell viability, and the bromodeoxyuridine incorporation assay as an indicator of cell proliferation, the influence of Angiotensin IV was evaluated on two human prostate cancer lines: androgen-dependent (LNCaP) and androgen-independent (DU-145). The potential effect of Angiotensin IV classic angiotensin receptors was examined by using the selective antagonists losartan and PD123319. Finally, the changes in expression levels of AT1 and AT2 receptors were compared, before and after angiotensin treatment. Angiotensin IV caused significant changes in cell viability and proliferation in LNCaP cells but not in DU-145. It was found that AT2 receptor blocker (PD123319) was able to diminish the suppressor effect of Angiotensin IV on bromodeoxyuridine incorporation into the DNA of androgen-dependent prostate cancer cells. Simultaneously, it was reported that Angiotensin IV is the factor that modulates the density of AT1 and AT2 receptors in prostate cancer cells. These findings suggested that Angiotensin IV can modulate tumour cell proliferation in the early stage of androgen-dependent prostate cancer. The effect might be promoted by the change of the angiotensin receptor level.