Abstract
Sivalokanathan Sarveswaran1, Nadimpalli R.S. Varma1, Shravan Morisetty1 and Jagadananda Ghosh1
1Vattikuti Urology Institute and Josephine Ford Cancer Center, Henry Ford Health System, Detroit, MI 48202, USA
Correspondence to:
Jagadananda Ghosh, email: jghosh1@hfhs.org
Keywords: 5-lipoxygenase, c-Myc, prostate cancer stem cells, MK591, apoptosis
Received: August 16, 2016 Accepted: November 07, 2016 Epub: November 17, 2016 Published: January 11, 2019
ABSTRACT
The cancer stem cell (CSC) concept suggests that neoplastic clones are maintained exclusively by a rare group of cells possessed with stem cell properties. CSCs are characterized by features that include self-renewal, pluripotency and tumorigenicity, and are thought to be solely responsible for tumor recurrence and metastasis. A hierarchically organized CSC model is becoming increasingly evident for various types of cancer, including prostate cancer. The CD44 (+), CD133 (+) cell subpopulations were isolated from human prostate tumors which exhibit stem-like properties showing therapeutic-resistance, capacity of self-renewal, and exact recapitulation of the original tumor in vivo. Thus, an important challenge is to find measures to eliminate these cancer stem cells, which will stop tumor growth and prevent disease-recurrence. However, knowledge about molecular features critical for the survival of prostate cancer stem cells (PCSC) is meager. Here we report that inhibition of 5-lipoxygenase (5-Lox) by shRNA or MK591 dramatically kills PCSC by inducing apoptosis, suggesting that 5-Lox plays an essential role in the survival of PCSC. Interestingly, MK591 treatment decreases protein levels and inhibits transcriptional activities of Nanog and c-Myc. Since Nanog and c-Myc play important roles as stemness factors, our findings indicate that the 5-Lox activity plays a causal role in maintaining prostate cancer stemness via regulation of Nanog and c-Myc, and suggest that further exploration of 5-Lox-mediated signaling in PCSC may lead to development of novel, target-based, durable strategies to effectively block development and growth of prostate tumors, and prevent prostate cancer recurrence.