Isothiocyanates attenuate heparin-induced proliferation of colon cancer cells in vitro

Isothiocyanates (ITCs), prevalent in cruciferous vegetables, are known for their anticarcinogenic properties. Prior research has indicated that heparin can stimulate the growth of colon cancer cells. However, the implications of ITCs in the diet of cancer patients receiving heparin-based therapies have yet to be fully understood. This exploratory in vitro study examines the proliferative effects of low-molecular-weight heparin (LMWH) on human colon cancer cells and assesses the antiproliferative potential of four ITC compounds, exploring possible epidermal growth factor family of receptor tyrosine kinases (Erb-B) related mechanisms. We evaluated cell viability in HCT-116 and HT-29 cell lines following treatment with ITCs alone or combined with LMWH (20 μg/mL) at various concentrations (1-100 μM). Clonogenic and wound-healing assays were performed after 24 h of treatment with 5 μM ITCs. Additionally, messenger RNA (mRNA) and protein expression of Erb-B family genes was measured using quantitative polymerase chain reaction (qPCR) and Western blotting. Statistical analysis was conducted using analysis of variance (ANOVA) with Dunnett's post hoc test. Results indicated that the half-maximal inhibitory concentration (IC₅₀) values for Phenylethyl isothiocyanate (PEITC), Benzyl isothiocyanate (BITC), and Sulforaphane (SFN) were lower than those of Allyl isothiocyanate (AITC) in LMWH-stimulated HCT-116 (20.77, 19.10, and 44.05 μM, respectively) and HT-29 (74.94, 26.77, and 43.49 μM, respectively). PEITC and SFN significantly reduced ErbB1 (epidermal growth factor receptor (EGFR)) and ErbB4 (receptor tyrosine-protein kinase erbB-4) expression, while BITC decreased ErbB2 (receptor tyrosine-protein kinase erbB-2) and transforming growth factor beta (TGF-β) expression in HCT-116 cells (all, p < .05). PEITC, BITC, and SFN also increased proapoptotic Bax expression and decreased the antiapoptotic B-cell lymphoma 2 (Bcl-2) expression (all, p < .05). These findings suggest that specific ITCs may mitigate cancer cell proliferation induced by LMWH in cancer therapies, highlighting their potential therapeutic efficacy.