Growth inhibition and apoptosis in colorectal cancer cells induced by Vitamin D-Nanoemulsion (NVD): involvement of Wnt/β-catenin and other signal transduction pathways

Cell Biosci. 2019 Feb 1;9:15. doi: 10.1186/s13578-019-0277-z. eCollection 2019.


Background: More than the two decades, the question of whether vitamin D has a role in cancer frequency, development, and death has been premeditated in detail. Colorectal, breast, and prostate cancers have been a scrupulous spot of center, altogether, these three malignancies report for approximately 35% of cancer cases and 20% of cancer demises in the United States, and as such are a chief public health apprehension. The aim was to evaluate antitumor activity of Vitamin D-Nanoemulsion (NVD) in colorectal cancer cell lines and HCT116 xenograft model in a comprehensive approach.

Methods: Two human colorectal cancer cell lines HCT116 and HT29 (gained from College of Pharmacy, King Saud University, KSA were grown. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazoliumbromide protocol were performed to show the impact of NVD and β-catenin inhibitor (FH535) on the viability of HCT116 and HT29 cell lines. Apoptosis/cell cycle assay was performed. Analysis was done with a FACScan (Becton-Dickinson, NJ). About 10,000 cells per sample were harvested and Histograms of DNA were analyzed with ModiFitLT software (verity Software House, ME, USA). Western blotting and RT-PCR were performed for protein and gene expression respectively in in vitro and in vivo.

Results: We found that NVD induced cytotoxicity in colorectal cells in a dose-dependent manner and time dependent approach. Further, our data validated that NVD administration of human colorectal cancer HCT116 and HT29 cells resulted in cell growth arrest, alteration in molecules regulating cell cycle operative in the G2 phase of the cell cycle and apoptosis in a dose dependent approach. Further our results concluded that NVD administration decreases expression of β-catenin gene, AKT gene and Survivin gene and protein expression in in vitro and in vivo.

Conclusion: Our findings suggest that targeting β-catenin gene may encourage the alterations of cell cycle and cell cycle regulators. Wnt/β-catenin signaling pathway possibly takes part in the genesis and progression of colorectal cancer cells through regulating cell cycle and the expression of cell cycle regulators.

Keywords: CRC; Cell cycle; NVD; Vitamin D; Wnt/β-catenin.