Sildenafil potentiates the therapeutic efficacy of docetaxel in advanced prostate cancer by stimulating NO-cGMP signaling

Sakthivel Muniyan, Satyanarayana Rachagani, Seema Parte, Sushanta Halder, Parthasarathy Seshacharyulu, Prakash Kshirsagar, Jawed A. Siddiqui, Raghupathy Vengoji, Sanchita Rauth, Ridwan Islam, Kavita Mallya, Kaustubh Datta, Lei Xi, Anindita Das, Benjamin A. Teply, Rakesh C. Kukreja, Surinder K. Batra

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


Purpose: Docetaxel plays an indispensable role in the management of advanced prostate cancer. However, more than half of patients do not respond to docetaxel, and those good responders frequently experience significant cumulative toxicity, which limits its dose duration and intensity. Hence, a second agent that could increase the initial efficacy of docetaxel and maintain tolerability at biologically effective doses may improve outcomes for patients. Experimental Design: We determined phosphodiesterase 5 (PDE5) expression levels in human and genetically engineered mouse (GEM) prostate tissues and tumor-derived cell lines. Furthermore, we investigated the therapeutic benefits and underlying mechanism of PDE5 inhibitor sildenafil in combination with docetaxel using in vitro, Pten conditional knockout (cKO), derived tumoroid and xenograft prostate cancer models. Results: PDE5 expression was higher in both human and mouse prostate tumors and cancer cell lines compared with normal tissues/cells. In GEM prostate-derived cell lines, PDE5 expression increased from normal prostate (wild-type) epithelial cells to androgen-dependent and castrated prostate-derived cell lines. The addition of physiologically achievable concentrations of sildenafil enhanced docetaxel-induced prostate cancer cell growth inhibition and apoptosis in vitro, reduced murine 3D tumoroid growth, and in vivo tumorigenicity as compared with docetaxel alone. Furthermore, sildenafil enhanced docetaxel-induced NO and cGMP levels thereby augmenting antitumor activity. Conclusions: Our results demonstrate that sildenafil's addition could sensitize docetaxel chemotherapy in prostate cancer cells at much lesser concentration than needed for inducing cell death. Thus, the combinatorial treatment of sildenafil and docetaxel may improve anticancer efficacy and reduce chemotherapy-induced side-effects among patients with advanced prostate cancer.

Original languageEnglish (US)
Pages (from-to)5720-5734
Number of pages15
JournalClinical Cancer Research
Issue number21
StatePublished - Nov 1 2021

ASJC Scopus subject areas

  • Oncology
  • Cancer Research


Dive into the research topics of 'Sildenafil potentiates the therapeutic efficacy of docetaxel in advanced prostate cancer by stimulating NO-cGMP signaling'. Together they form a unique fingerprint.

Cite this