Effectiveness of Rhenium(I)-diselenoether Low Doses in a Triple-negative Breast Cancer Chicken Embryo Model.

BACKGROUND/AIM: Rhenium(I)-diselenoether (Re-diSe) is a promising anticancer agent composed of one rhenium and two selenium atoms. Its effectiveness was established in inhibiting cancer cells while maintaining low toxicity toward normal cells at a 5 µM dose for 120 hours in MDA-MB-231 cells. In MDA-MB-231 breast tumor-bearing mice, anti-tumor and anti-metastatic effects were observed at a 10 mg/kg dose. However, contradictory results were observed in the 4T1 breast cancer model, where a dose of 60 mg/kg had a pro-tumor effect. To address these discrepancies, the efficacy of Re-diSe at the effective 10 mg/kg dose was validated in a transplanted MDA-MB-231 breast tumor model using the chicken chorioallantoic membrane assay. MATERIALS AND METHODS: MDA-MB-231 cancer cells were xenografted onto the chicken chorioallantoic membrane (CAM), and daily drug administration was carried out for nine days at doses of 0.1, 1, and 10 mg/kg. At the study's conclusion, a standard histological analysis was conducted. RESULTS: The low dose of 0.1 mg/kg showed a significant reduction in tumor weights compared to controls. The 1 mg/kg dose resulted in an increased inflammation score but did not induce a significant difference in tumor weights compared to the 0.1 mg/kg dose. Notably, at the 10 mg/kg dose, six out of 11 treated embryos displayed no visible signs of tumors. These tumors exhibited extensive tumor necrosis and significant infiltration by inflammatory cells. CONCLUSION: In this particular model, the anticancer efficacy of Re-diSe was achieved at the low dose of 0.1 mg/kg. The higher dose of 10 mg/kg, while eliminating visible tumors, might have immune-mediated effects, as indicated by substantial tumor necrosis and infiltration by inflammatory cells. Overall, this study successfully demonstrated the effectiveness of Re-diSe as an anticancer agent.

Remarkable Effects of a Rhenium(I)-diselenoether Drug on the Production of Cathepsins B and S by Macrophages and their Polarizations.

BACKGROUND/OBJECTIVE: Tumor-associated macrophages (TAMs) produce an excessive amount of cysteine proteases, and we aimed to study the effects of anticancer rhenium(I)-diselenoether (Re-diSe) on the production of cathepsins B and S by macrophages. We investigated the effect of Re-diSe on lipopolysaccharides (LPS) induced M1 macrophages, or by interleukin 6 (IL-6) induced M2 macrophages. METHODS: Non-stimulated or prestimulated murine Raw 264 or human THP-1 macrophages were exposed to increasing concentrations of the drug (5, 10, 20, 50 and 100 µM) and viability was assayed by the MTT assay. The amount of cysteine proteases was evaluated by ELISA tests, the number of M1 and M2 macrophages by the expression of CD80 or CD206 biomarkers. The binding of Re-diSe with GSH as a model thiol-containing protein was studied by mass spectrometry. RESULTS: A dose-dependent decrease in cathepsins B and S was observed in M1 macrophages. There was no effect in non-stimulated cells. The drug induced a dramatic dose-dependent increase in M1 expression in both cells, significantly decreased the M2 expression in Raw 264 and had no effect in non-stimulated macrophages. The binding of the Re atom with the thiols was clearly demonstrated. CONCLUSION: The increase in the number of M1 and a decrease in M2 macrophages treated by Re-diSe could be related to the decrease in cysteine proteases upon binding of their thiol residues with the Re atom.

In vitro and in silico anti-leukemic activity of 2-amino-6-nitro-4-(4-oxo-2-thioxothiazolidin-5-yl)-4H-chromene-3-carbonitrile (ANC) through inhibition of anti-apoptotic Bcl-2 proteins.

An array of 4H-chromene derivatives have been reported for anticancer properties but their selectivity and mode of anticancer activity are unexplored. In this context, we have investigated a biologically active synthetically designed 4H-Chromene carbonitrile derivative, 2-amino-6-nitro-4-(4-oxo-2-thioxothiazolidin-5-yl)-4H-chromene-3-carbonitrile (ANC) that is strongly and selectively inhibited Bcl-2 over expressing human leukemic (HL-60 and K562) cells for its interaction and elucidated the mode of action. The interaction of ANC was investigated against the antiapoptotic proteins such as Bcl-2, Bax, Bcl-xL and Bcl-w that were overexpressed in leukemic cells using in silico and fluorescent spectroscopic studies. Fluorescent spectroscopic based interaction studies showed that the derivative had strong interaction with Bcl-xL followed by Bcl-2/Bax and least interaction with Bcl-w. Based on the results, the ANC had strong interactions with antiapoptotic Bcl-2 and Bax proteins than the Bcl-xL and Bcl-w proteins. The in vitro biological validation of ANC treated leukemic cells showed downregulation of Bcl-xL than Bcl-2 but least effect on Bcl-w proteins. Furthermore, the ANC had possible four isomers as RR, RS, SR and SS isomers. Among them, RS isomer of ANC had shown more active that correlated with biological interactions and gene expression studies of ACN with oncoproteins. These results confirmed the induction of apoptosis by RS-ACN isomer through inhibition of antiapoptotic machineries of leukemic cells confirming the antiapoptotic Bcl-2 inhibitory activities.Communicated by Ramaswamy H. Sarma.

A New Model Applied for Evaluating a Rhenium-diselenium Drug: Breast Cancer Cells Stimulated by Cytokines Induced from Polynuclear Cells by LPS.

BACKGROUND/AIM: New anticancer drugs are usually tested on cancer cells in culture in a standard medium. We stimulated immune polynuclear cells by lipopolysaccharides to obtain an enriched medium (EM) containing inflammatory cytokines more closely reflecting the tumor microenvironment and tested a rhenium-diselenium (Re-diSe) drug in this new model. Concentrations of cytokines were compared with a control medium (CM). MATERIALS AND METHODS: Human-derived breast cancer cells were grown in culture either in CM or EM with or without Re-diSe. Assays of tumor necrosis factor alpha (TNFα), interleukin 6 (IL6), intereukin 1 beta (IL1ß), transforming growth factor-beta (TGFß), insulin growth factor 1 (IGF1) and vascular epidermal growth factor A (VEGFA) were performed by enzyme-linked immunosorbent assays. The production of reactive oxygen species (ROS) was determined by 2,7-dichlorofluorescein test. The cell growth was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tests. RESULTS: Concentrations of TNFα, IL6 and Il1ß were observed to be significantly higher in EM than in CM. There was no difference for TGFß, IGF1 and VEGFA. The cells were sensitive to Re-diSe, with reduced concentrations of TGFß, IGF1, VEGFA and ROS, but the half-maximal inhibitory concentration was significantly higher in EM than in CM. CONCLUSION: The efficacy of the Re-diSe drug was confirmed in this model of aggressive cancer.

The rhenium(I)-diselenoether anticancer drug targets ROS, TGF-ß1, VEGF-A, and IGF-1 in an in vitro experimental model of triple-negative breast cancers.

The rhenium(I)-diselenoether complex (Re-diSe) is a rhenium tricarbonyl-based drug chelated by a diselenoether ligand. In this work, we compared its inhibitory effects on the hormone-independent MDA-MB231cancer line and other different cancer cell lines after an exposure time of 72 h by MTT assays. The sensitivity of MDA-MB231 was in the same range than the hormone-dependent MCF-7 breast cancer, the PC-3 prostate and HT-29 colon cancer cells, while the A549 lung and the HeLa uterine cancer cells were less sensitive. We compared the inhibitory effects of Re-diSe and of its diselenide ligand (di-Se) on MDA-MB231 and a normal HEK-293 human embryonic cell line, after 72 h and 120 h of exposure. The cytotoxicity was also studied by flow cytometry using ethidium bromide assays, as well as the effects on the ROS production by DFCA-test, while the levels of TGF-ß1, VEGF-A, IGF-1 were addressed by ELISA tests. The dose required to inhibit 50% of the proliferation (IC50) of MDA-MB231 breast cancer cells decreased with the time of exposure to 120 h, while the free ligand (di-Se) was found poorly active, demonstrating the important role of Re in this Re-diSe combination. The cytotoxic effects of Re-diSe were highly selective for cancer cells, with a significant increase of the number of dead cancer cells at 5 µM for an exposure time of 120 h, while normal cells were not affected. A remarkable and significant decrease of the production of ROS together with a decrease of VEGF-A, TGF-ß1, and IGF-1 by the cancer cells were also observed when cancer cells were exposed to Re-diSe.

Anti-leukemic, anti-lung, and anti-breast cancer potential of the microbial polyketide 2, 4-diacetylphloroglucinol (DAPG) and its interaction with the metastatic proteins than the antiapoptotic Bcl-2 proteins.

The microbial polyketide, 2, 4-diacetylphloroglucinol (DAPG), exhibited a broad-spectrum of anti-leukemic, anti-lung, and anti-breast cancer properties. The aim of the present investigation was to study the interactive potentials of DAPG with the metastatic proteins such as MMP-2, MMP-9, and NF-κB and antiapoptotic Bcl-2 family proteins such as Bcl-2, Bcl-w, and Bcl-xL through in silico interaction and in vitro studies. The in silico modeling predicted high interactions of DAPG with the metastatic proteins, especially MMP-2, MMP-9, and NF-κB with the glide score of -7.028, -6.304, and -5.231, respectively. Similarly, the DAPG had weak interactions with the antiapoptotic Bcl-2, Bcl-w, and Bcl-xL with the glide score of -4.505, -3.839, and -4.003, respectively. The interaction studies further revealed the inhibition of MMP-2, MMP-9, and NF-κB activities with the low IC50 concentration of 5.82 ± 1.6, 6.74 ± 1.2, and 10.7 ± 1.5 µM respectively, in the presence of DAPG. Similarly, DAPG inhibited the Bcl-2, Bcl-xL and Bcl-w activities with the high IC50 concentration of 29.8 ± 1.9, 85.9 ± 2.7, and 97.4 ± 1.5 µM, respectively. These results correlate with the relatively high IC50 concentration of 16.3 ± 1.76, 7.67 ± 0.78, and 10.7 ± 0.96 µM in the Bcl-2-overexpressing HL-60, K562 and Raji leukemic cells than the metastatic A549 and MDA MB-231 cancer cells with the low IC50 concentration of 0.06 ± 0.02 and 0.08 ± 0.01 µM, respectively, compared to the healthy, human embryonic kidney (HEK-293) cells with the high IC50 concentration of 54.7 ± 1.43 µM. In summary, the affinity of DAPG with proteins are in the order of MMP-2 > MMP-9 > NF-κB > Bcl-2 > Bcl-xL > Bcl-w. Results presented in this study confirmed the high interaction of DAPG with the metastatic proteins than the antiapoptotic Bcl-2 family proteins.

In vitro antiproliferative, pro-apoptotic, antimetastatic and anti-inflammatory potential of 2,4-diacetylphloroglucinol (DAPG) by Pseudomonas aeruginosa strain FP10.

The 2,4-diacetylphloroglucinol (DAPG), a polyketide metabolite extracted from Pseudomonas aeruginosa strain FP10, exhibited selective cytoxicity against lung (A549), breast (MDA MB-231), cervical (HeLa) and colon (HCT-15) cancer cells in differential and dose-dependent manner. The anticancer and antimetastatic activities of DAPG were mediated by the inhibition of ROS, NF-κB, Bcl-2, MMP-2, VEGF and primary inflammatory mediators such as TNF-α, IL-6, IL-1ß and NO. The DAPG induced apoptosis in cancer cells by intrinsic and extrinsic pathways via the release of cytochrome-C, upregulation of Bax and the activation of caspases and also, exhibited anti-inflammatory activity by the inhibition of LPS-inflammed cell proliferation of macrophage (Raw 264.7), monocytic cells (THP-1) and peripheral blood mononuclear cells (PBMCs). Results further confirmed that the DAPG inhibited the primary inflammatory mediators in cancer cells and inflammed immune cells through the down regulation of NF-κB. In the present study, for the first time, antiproliferative, proapoptotic, antimetastatic and anti-inflammatory activities of DAPG in various cancer cells and inflammation-induced immune cells have been reported.