1alpha, 25(OH)2-vitamin D3 effects in cellular cycle of rhabdomyosarcoma cells

Abstract

Our research group has recently opened a new investigation line about 1,25(OH)2-vitamin D3 (1,25D) hormone actions in rhabdomyosarcoma cells. Rhabdomyosarcoma is one of soft tissue cancers that affects skeletal muscle and bone, predominantly in kids and older people. Treatments employed to fight this pathology did not advance in the last 30 years. In this work we use the cellular line of human rhabdomyosarcoma, RD, and we evidence that the hormone promotes interesting changes in the cellular cycle. Our data indicate that 1 nM of 1,25D significantly diminishes the amount of live cells at 72 h of treatment (respect its control). When we analyzed the phases of cellular cycle by flow cytometry, we observed that the hormone reduces the number of cells into S phase (at 48 and 72 h of treatment) with a concomitant augment of cells into G0/G1 phase. These results reveal that 1,25D controls rhabdomyosarcoma cells proliferation. To go in deep with these results, we studied the behavior of cellular cycle key proteins by Western blot assays. We determinate that cells treated for 72 h with 1,25D showed an increase in the cyclin D1 and cyclin D3 expression. Of relevance, we evidenced that the hormone augments the protein levels of cyclin dependent kinase inhibitors. Our results indicate that the hormone regulates the cellular cycle of rhabdomyosarcoma cells. Altogether these outcomes open doors to investigate in deep the modulation of different signaling cascades involved in the inhibition of proliferation of these cancer cells exerted by 1,25D.