AMBRA1 and SQSTM1 expression pattern in prostate cancer

Prostate cancer is among the most commonly diagnosed male diseases and a leading cause of cancer mortality in men. There is emerging evidence that autophagy plays an important role in malignant cell survival and offers protection from the anti-cancer drugs in prostate cancer cells. AMBRA1 and the autophagic protein sequestosome-1 (SQSTM1; p62) expression were evaluated by immunohistochemistry and western blot on tissue samples from both benign and malignant prostatic lesions. The data reported in this pilot study demonstrated an increased expression of AMBRA1 and SQSTM1, which were also associated with an accumulation of LC3II in prostate cancer but not in benign lesion. In the present study we found that: (i) at variance with benign lesion, prostate cancer cells underwent SQSTM1 accumulation, i.e., clearly displayed a defective autophagic process but, also, (ii) prostate cancer accumulated AMBRA1 and (iii) this increase positively correlated with the Gleason score. These results underscore a possible implication of autophagy in prostate cancer phenotype and of AMBRA1 as possible cancer progression biomarker in this malignancy.