Apoptosis induction in HeLa cervical cancer cell line by steroidal 16,17-seco-16,17a-dinitriles Scientific paper

Abstract

Steroids are good candidates for drug development, thanks to their low general toxicity and possibility for structure modifications connected with change of their activity. Several 16,17-secoandrost-4-ene-16,17a-dinitrile com­pounds were syn­thesized and screened for anticancer effect previously, inc­luding 6-oxo and 6-hy­droxyimino compounds. This research is continued with the attempts for dif­fer­ent synthetic strategy and evaluation of anticancer effect mechanism. Syn­thesis of 3-hydroxyimino compounds was successful, but inseparable mix of isomers was excluded from biological tests. Tested seco­di­nitriles expressed cyto­toxic effect on HeLa cervix cancer cells as a model sys­tem, with submicromolar to molar IC₅₀ values, where 6-substituted derivatives were more effective. After 72 h treatment with equitoxic concentrations equal IC₅₀ values of test com­pounds the mechanism of this effect was studied using flow cytometry and specific fluorescent dyes. Mod­est change in both G0/G1 and G2/M resting phases and change in mito­chondrial membrane potential were noticed, while the most prono­unced effect was apoptosis induction. Total apoptosis was in range 50.72–58.31 % in all cell samples treated with secodi­nit­riles, compared to 7.44 % in control samples. Total percent of dead cells, including both apoptotic and necrotic, ranged from 55.24 to 65.34 %, com­pared to 10.68 % in control. Selectivity towards cancer cells is very important feat­ure of these compounds indicating their potential use as lead compounds in the drug development for the treatment of cancers of steroid hormone-dependent tissues.