La-Or Somsakeesit

Background/Objectives: Drug resistance and severe side effects caused by gemcitabine (Gem) and cisplatin (CDDP) are common. This study aimed to investigate the combined effects of CU4c and Gem or CDDP on lung cancer cells in vitro and in nude mouse xenograft models. Methods: Antiproliferative activity and drug interaction were evaluated using MTT and Chou–Talalay methods, respectively. Apoptosis induction and cell cycle arrest were analyzed by flow cytometry. The expression levels of proteins were evaluated by Western blot analysis. The HDAC-inhibitory activity of CU4c was confirmed in vitro, in silico, and in A549 cells. Results: CU4c inhibited the proliferation of A549 cells in a dose- and time-dependent manner but had little effect on the growth of noncancerous Vero cells. CU4c synergistically enhanced the antiproliferative activities of CDDP (at 24 h) and Gem (at 48 and 72 h) against A549 cells. Combined CU4c and CDDP notably inhibited A549 proliferation by triggering cell cycle arrest at S and G2/M phases at 24 h with elevated levels of p21 and p53 proteins. Combined CU4c and Gem induced cell cycle arrest at both the S and G2/M phases at 48 h via upregulating the expression of the p21 protein. CU4c enhanced the apoptotic effects of CDDP and Gem by increasing the Bax/Bcl-2 ratio, pERK1/2, and Ac-H3 levels. Combined CU4c and Gem significantly reduced tumor growth while minimizing visceral organ damage in animal study. Conclusions: These results suggest that CU4c enhances the anticancer activity of CDDP and Gem and reduces the toxicity of Gem in animal studies.

Recently, the curcumin derivative CU17 possessing HDAC inhibitory activity has been shown to synergistically enhance the anti-proliferative activity of Gem against lung cancer cells. Nevertheless, the mechanism(s) underlying the synergistic anti-cancer effect remains to be investigated. This study aimed to investigate the mechanisms that underpin the anti-cancer activity of the combined Gem and CU17 against NSCLC A549 cells both in vitro and in mouse xenograft models. CU17 was successfully synthesized and subsequently investigated for its combination effects with Gem on inductions of cell cycle arrest and apoptosis in A549 cells. The combination treatment substantially decreased cell survival through S phase prolongation and G2/M phase cell cycle arrest via up-regulating the expressions of p21 and p53 proteins. Additionally, CU17 potentiated the apoptotic effect of Gem in A549 cells by increasing the Bax/Bcl-2 ratio. The co-treatment resulted in an up-regulation of pERK1/2 and Ac-H3 expression. An in vivo study demonstrated that CU17 significantly improved the anti-cancer effect of Gem in nude mice utilizing A549 cell xenografts. The hematoxylin and eosin (H&E) staining results indicated that CU17 decreased the toxicity of Gem to the liver, kidneys, and spleen. Overall, CU17 enhanced the effectiveness of Gem while decreasing its toxicity. This compound shows promise as a chemosensitizer for NSCLC treatment with Gem.

This study presented the expression of the outer membrane protein N in E. coli BL21 (DE3) Omp8 Rosetta under its growth condition and by osmoregulation. The effects of osmotic stress caused by salts, sugars, or pH values on the survival of the target Gram-negative bacterial strain of E. coli BL21 (DE3) Omp8 Rosetta and OmpN expression remain unknown. Here, tryptone yeast extract with varied salts and concentrations was initially used to generate an LB broth medium. To show how salts and concentration affect bacterial growth, the optical density at 600 nm was measured. The findings supported the hypothesis that salts and concentrations control bacterial growth. Moreover, a Western blotting study revealed that OmpN overexpression was present in all tested salts after stimulation with both glucose and fructose after being treated individually with anti-OmpN and anti-histidine tag polyclonal antibodies on transferred nitrocellulose membrane containing crude OmpN. Following the presence of the plasmid pET21b(+)/ompN-BOR into E. coli BL21 (DE3) Omp8 Rosetta, which was expressed in the recombinant OmpN protein (BOR), OmpN expression was demonstrated for all monovalent cations as well as MgCl₂. All of the tested salts, except for BaCl₂, NaH₂PO₄, and KH₂PO₄, showed overexpression of recombinant BOR after Isopropyl β-D-1-thiogalactopyranoside (IPTG) induction. Using CH₃COONa, both with and without IPTG induction, there was very little bacterial growth and no OmpN expression. With NaCl, a pH value of 7 was suitable for bacterial development, whereas KCl required a pH value of 8. According to this research, bacterial growth in addition to salts, sugars, and pH values influences how the OmpN protein is produced.

Previous research reported that the curcumin derivative (CU17) inhibited several cancer cell growths in vitro. However, its anticancer potential against human lung cancer cells (A549 cell lines) has not yet been evaluated. The purpose of this research was to examine the HDAC inhibitory and anti-cancer activities of CU17 compared to curcumin (CU) in A549 cells. An in vitro study showed that CU17 had greater HDAC inhibitory activity than CU. CU17 inhibited HDAC activity in a dose dependent manner with the half-maximal inhibitory concentration (IC₅₀) value of 0.30 ± 0.086 µg/mL against HDAC enzymes from HeLa nuclear extract. In addition, CU17 could bind at the active pockets of both human class I HDACs (HDAC1, 2, 3, and 8) and class II HDACs (HDAC4, 6, and 7) demonstrated by molecular docking studies, and caused hyperacetylation of histone H3 (Ac-H3) in A549 cells shown by Western blot analysis. MTT assay indicated that both CU and CU17 suppressed A549 cell growth in a dose- and time-dependent manner. Besides, CU and CU17 induced G2/M phase cell cycle arrest and p53-independent apoptosis in A549 cells. Both CU and CU17 down-regulated the expression of p53, p21, Bcl-2, and pERK1/2, but up-regulated Bax expression in this cell line. Although CU17 inhibited the growth of lung cancer cells less effectively than CU, it showed less toxicity than CU for non-cancer cells. Accordingly, CU17 is a promising agent for lung cancer treatment. Additionally, CU17 synergized the antiproliferative activity of Gem in A549 cells, indicating the possibility of employing CU17 as an adjuvant treatment to enhance the chemotherapeutic effect of Gem in lung cancer.

Twenty newly synthesized derivatives of [6]-shogaol (4) were tested for inhibitory activity against histone deacetylases. All derivatives showed moderate to good histone deacetylase inhibition at 100 µM with a slightly lower potency than the lead compound. Most potent inhibitors among the derivatives were the pyrazole products, 5j and 5k, and the Michael adduct with pyridine 4c and benzothiazole 4d, with IC₅₀ values of 51, 65, 61 and 60 µM, respectively. They were further evaluated for isoform selectivity via a molecular docking study. Compound 4d showed the best selectivity towards HDAC3, whereas compound 5k showed the best selectivity towards HDAC2. The potential derivatives were tested on five cancer cell lines, including human cervical cancer (HeLa), human colon cancer (HCT116), human breast adenocarcinoma cancer (MCF-7), and cholangiocarcinoma (KKU100 and KKU-M213B) cells with MTT-based assay. The most active histone deacetylase inhibitor 5j exhibited the best antiproliferative activity against HeLa, HCT116, and MCF-7, with IC₅₀ values of 8.09, 9.65 and 11.57 µM, respectively, and a selective binding to HDAC1 based on molecular docking experiments. The results suggest that these compounds can be putative candidates for the development of anticancer drugs via inhibiting HDACs.