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.

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.