Isothiocyanate analogs targeting CD44 receptor as an effective strategy against colon cancer

Misra S, Ghatak S, Vyas A, O’Brien P, Markwald RR, Khetmalas M, Hascall VC, McCarthy JB, Karamanos NK, Tammi MI, Tammi RH, Prestwitch GD, Padhye S. Isothiocyanate analogs targeting CD44 receptor as an effective strategy against colon cancer. Med Chem Res. 2014 Aug 1;23(8):3836-3851. PMID: 25013352 PMCID: PMC4084864

Inflammatory pathway plays an important role in tumor cell progression of colorectal cancers. Although colon cancer is considered as one of the leading causes of death worldwide, very few drugs are available for its effective treatment. Many studies have examined the effects of specific COX-2 and 5-LOX inhibitors on human colorectal cancer, but the role of isothiocyanates (ITSCs) as COX-LOX dual inhibitors engaged in hyaluronan-CD44 interaction has not been studied. In the present work, we report series of ITSC analogs incorporating bioisosteric thiosemicarbazone moiety. These inhibitors are effective against panel of human colon cancer cell lines including COX-2 positive HCA-7, HT-29 cells lines, and hyaluronan synthase-2 (Has2) enzyme over-expressing transformed intestinal epithelial Apc10.1Has2 cells. Specifically, our findings indicate that HA-CD44v6-mediated COX-2/5-LOX signaling mediate survivin production, which in turn, supports anti-apoptosis and chemo-resistance leading to colon cancer cell survival. The over-expression of CD44v6shRNA as well as ITSC treatment significantly decreases the survival of colon cancer cells. The present results thus offer an opportunity to evolve potent inhibitors of HA synthesis and CD44v6 pathway and thus underscoring the importance of the ITSC analogs as chemopreventive agents for targeting HA/CD44v6 pathway.

KEYWORDS: Anti-cancer; CD44/hyaluronan; COX–LOX dual inhibition; Colon cancer; Isothiocyanate analogs; Molecular modeling