Hydrogen Sulfide: Emerging Role in Bladder, Kidney, and Prostate Malignancies.

Hydrogen sulfide (HS) is the latest member of the gasotransmitter family and known to play essential roles in cancer pathophysiology. HS is produced endogenously and can be administered exogenously. Recent studies showed that HS in cancers has both pro- and antitumor roles. Understanding the difference in the expression and localization of tissue-specific HS-producing enzymes in healthy and cancer tissues allows us to develop tools for cancer diagnosis and treatment. Urological malignancies are some of the most common cancers in both men and women, and their early detection is vital since advanced cancers are recurrent, metastatic, and often resistant to treatment. This review summarizes the roles of HS in cancer and looks at current studies investigating HS activity and expression of HS-producing enzymes in urinary cancers. We specifically focused on urothelial carcinoma, renal cell carcinoma, and prostate cancer, as they form the majority of newly diagnosed urinary cancers. Recent studies show that besides the physiological activity of HS in cancer cells, there are patterns between the development and prognosis of urinary cancers and the expression of HS-producing enzymes and indirectly the HS levels. Though controversial and not completely understood, studying the expression of HS-producing enzymes in cancer tissue may represent an avenue for novel diagnostic and therapeutic strategies for addressing urological malignancies.