Evaluation of molecular effects associated with apoptosis, tumour progression, angiogenesis and metastasis by a novel combination of drugs with ormeloxifene in triple negative breast cancer cells.

Aim: To investigate the molecular effects of a novel combination [sertraline and plumbagin (comb) with ormeloxifene (Orm)] for anticancer activity in triple negative breast cancer cell line "MDA-MB-231". Methods: The cytotoxic effect of the drugs was analyzed by the MTT assay and nuclear morphological changes by acridine orange/ethidium bromide (AO/EB) staining. Induction of apoptosis by annexin V-FITC staining, active caspase-3 detection and cell cycle analysis were studied in vitro on "MDA-MB-231" cells. The qRT-PCR was done to explore the upregulation and down regulation of targeted genes for angiogenesis, metastasis, tumor suppression and protein folding on the triple negative breast cancer cells. The preliminary anti-angiogenic effect of the drugs was assessed by chorioallantoic membrane (CAM) assay. Results: Orm showed inhibitory effects in "MDA-MB-231" cells in a dose and time dependent manner whereas; the drugs in combination gave better cytotoxic effects in the screening MTT assay. Orm + comb was more effective than Orm alone in eliciting apoptosis as well as inhibited the single cell to grow into a colony. CAM assay using Orm and Orm + comb suggested the anti-angiogenic potential which was further confirmed by the downregulation of VEGF in "MDA-MB-231" cells by qRT-PCR studies. The combination was found to effectively upregulate the expression of P53 and P21 and downregulate the gene expression of zinc finger E-box binding homeobox 1 (ZEB1) and heat shock protein 70 (HSP70) in "MDA-MB-231" cancer cells. Conclusions: Collectively this study reveals the efficacy of Orm + comb as more significant than the clinically used tamoxifen (Tam). The study elucidates the promising novelty of the combination as a potential chemotherapeutic intervention for mitigating the aggressiveness of triple negative breast cancer and it addresses the intrinsic resistance caused by single drug treatments.

Nonhormonal selective estrogen receptor modulator 1-(2-[4-{(3R,4S)-7-Methoxy-2, 2-dimethyl-3-phenyl-chroman-4yl}phenoxy]ethyl)pyrrolidine hydrochloride (ormeloxifene hydrochloride) for the treatment of breast cancer.

Breast cancer is the most common type of diagnosed cancers in women, difficult to treat, and has received international attention because of its aggressive nature and inherent drug resistance mechanisms. Development of a better selective estrogen receptor modulator with good therapeutic profile and less toxicity is very crucial in this scenario. This study was undertaken to evaluate and compare the in vitro and in vivo antitumor activities of ormeloxifene with other clinically used breast cancer drugs. Cytotoxic activity of ormeloxifene was compared with standard drugs, 4-hydroxytamoxifene and Adriamycin. Ormeloxifene (50 µM) concentration showed cytotoxicity of 75% and 82% in MDAMB-231 and 24% and 80% in MCF-7 cells, respectively, after 72 and 144 hr of incubation as displayed by cell viability assay. The same concentration of ormeloxifene was shown to exert 74% caspase-7 activation in MCF-7 cells after 24 hr of incubation by fluorescence resonance energy transfer assay. Cell cycle analysis proved that there was an increase in sub-G1 peak to 64.4% and 33.9% in MDAMB-231 and MCF-7 cells, respectively, after treatment using ormeloxifene (50 µM) for 48 hr. The nonobese diabetic-severe combined immunodeficiency mice bearing tumor xenografts of triple negative MDAMB-231 cells treated with ormeloxifene (3 mg/kg bw) showed significant regression in relative tumor volume compared to control. From the results obtained and as evidenced from prior literature, ormeloxifene in addition to contraceptive use, can be repositioned for the development of an efficacious anticancer drug. These data present the preclinical part of a well concerted effort to place ormeloxifene into further clinical trials.

Effect of lyophilization on HRP-antibody conjugation: an enhanced antibody labeling technology.

OBJECTIVE: Immunoassay usually deal with the antibody labeling with various reporter molecules, one such useful reporter molecule is horseradish peroxidase (HRPO). Conjugating enzyme with antibody without losing its enzymatic activity is a challenging task. Our aim is to modify existing classical method of conjugating antibodies with HRP to enhance immunoassay techniques with better sensitivity. We used chemicals such as sodium meta periodate to generate aldehyde group by oxidation of carbohydrate moieties on HRPO. The activated form of HRPO is lyophilized and then mixed with 1 mg/ml concentration of antibodies to be conjugate. RESULTS: After confirming chemical modification of conjugates via UV-Spec and SDS-PAGE independent molecules were used for conjugation and HRP-antibody conjugate. Finally, enzymatic activity of HRP-antibody conjugate was confirmed by performing direct ELISA. Functional properties were analyzed using ELISA with dilution of 1:5000, whereas the conjugate prepared by existing method of conjugation worked with as low dilution of 1:25 with a p value highly significant (< 0.001) for classical verses modified method of conjugation preparation. Collectively, this study showed the enhanced ability of antibody to bind more number of HRPO with an additional step of lyophilization in the regular conjugation protocol. Future exploration are necessary on wide range of IgG antibodies.