Novel dihydrobenzofuro[4,5-b][1,8]naphthyridin-6-one derivative, MHY-449, induces apoptosis and cell cycle arrest in HCT116 human colon cancer cells

Design, Synthesis, Anticancer Evaluation, and Molecular Docking Studies of Oxazole-Incorporated Naphthyridine Derivatives

A novel series of oxazole incorporated naphthyridine (21 a-j) derivatives were designed and, synthesized followed by screening of their anticancer activity profiles against human breast cancer (MCF-7), human lung cancer (A549) and human prostate (PC3 & DU-145) cancer cell lines by employing MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay using etoposide as the positive control. Of these compounds, N-(6-chloro-3-(4-(3,4,5-trimethoxyphenyl)oxazol-2-yl)-1,5-naphthyridin-4-yl)oxazol-2-amine with 3,4,5-trimethoxy substituent on the aryl moiety attached to oxazole ring showed potent anticancer activity against PC3, A549, MCF-7, and DU-145 cell lines with IC50 values of 0.13±0.095 μM; 0.10±0.084 μM; 0.18±0.087 μM and 0.15±0.076 μM respectively. Apart from this, compounds N-(6-chloro-3-(4-(3,5-dimethoxyphenyl)oxazol-2-yl)-1,5-naphthyridin-4-yl)oxazol-2-amine, N-(6-chloro-3-(4-(4-methoxyphenyl)oxazol-2-yl)-1,5-naphthyridin-4-yl)oxazol-2-amine, and N-(6-chloro-3-(4-(3,5-dimethylphenyl)oxazol-2-yl)-1,5-naphthyridin-4-yl)oxazol-2-amine also showed better anticancer activities against four cancer cell lines screened for. These activities were also validated through the molecular docking simulations, which further indicated demonstration of better interaction energy and profile by these compounds.

Cisplatin Activates the Growth Inhibitory Signaling Pathways by Enhancing the Production of Reactive Oxygen Species in Non-small Cell Lung Cancer Carrying an EGFR Exon 19 Deletion

BACKGROUND/AIM

Cisplatin is a potent anticancer drug for treating several types of cancer, including non-small-cell lung cancer (NSCLC). In this study, we investigated the cytotoxicity and mechanism of action of cisplatin in the human NSCLC cell line PC9.

MATERIALS AND METHODS

PC9 cells were treated with cisplatin for 72 h and then evaluated by a cell viability assay, DAPI staining, Giemsa staining, apoptosis assay, membrane permeability assay, cell cycle assay, ROS assay, SA-β-gal staining, TUNEL assay and Western blotting.

RESULTS

Our findings revealed that the cytotoxic activity was associated with an apoptotic signaling pathway in response to DNA damage. Cisplatin exerted a significant concentration-dependent antiproliferative effect on PC9 cells. Cells subjected to cisplatin treatment showed morphological indications of apoptosis. Cell cycle arrest was related to the restriction of E2F-1 action by the cyclin-dependent protein kinase inhibitor p21^WAF1/CIP1 Cisplatin induced apoptosis of PC9 cells by upregulating Fas, FasL, Bak, and tBID expression and PARP proteolytic cleavage. Cisplatin also reduced the mitochondrial membrane potential (MMP) and initiated a caspase cascade. Furthermore, the apoptotic impact of cisplatin depended on reactive oxygen species (ROS), as confirmed by ROS generation.

CONCLUSION

Cisplatin induced anticancer effects through cell cycle arrest, ROS generation and caspase activation, resulting in cell apoptosis. Overall, the results show the mechanism by which cisplatin works as an anticancer drug in the treatment of NSCLC.

Novel 1,8-Naphthyridine Derivatives: Design, Synthesis and in vitro screening of their cytotoxic activity against MCF7 cell line

A series of new 2-phenyl-7-methyl-1,8-naphthyridine derivatives with variable substituents at C3 were synthesized for an in vitro evaluation of their anticancer activity against human breast cancer cell line (MCF7). On one hand, compounds 3f, 6f, 8c, and 10b showed IC50 values (6.53, 7.88, 7.89, 7.79 μM, respectively) compared to that of the mentioned drug staurosparine (IC50 = 4.51 μM). On the other hand, derivatives 10c, 8d, 4d, 10f and 8b displayed better activity than staurosporin with IC50 values (1.47, 1.62, 1.68, 2.30, 3.19 μM, respectively).

Pro-apoptotic effect of the novel benzylidene derivative MHY695 in human colon cancer cells

The induction of apoptosis is a useful strategy in anti-cancer research. Various Moon Hyung Yang (MHY) compounds have been developed as novel anti-cancer drug candidates; in the present study, the pro-apoptotic effects of (Z)-5-(3-ethoxy-4- hydroxybenzylidene)-2-thioxothiazolidin-4-one (MHY695) on HCT116 human colon cancer cells were assessed. MTT assays were performed to investigate the dose-dependent cytotoxic effects of MHY695 on HCT116 cells. Immunofluorescence staining and flow cytometry analyses were performed to identify apoptotic cell death, and western blot analysis was used to investigate the apoptotic-signaling pathways. A mouse xenograft model was also used to determine the effects of MHY695 in vivo. MHY695 decreased the viability of HCT116 cells and induced apoptotic cytotoxicity. The apoptotic mechanisms induced by MHY695 involved the dephosphorylation of Bcl-2-associated agonist of cell death protein following protein kinase B inactivation, induced myeloid leukaemia cell differentiation protein and BH3-interacting domain death agonist truncation, caspase-3 and -9 activation and poly (ADP-ribose) polymerase cleavage. In addition, MHY695 significantly suppressed tumor growth in the mouse xenograft model, compared with the vehicle control. Notably, MHY695 exhibited potent anti-cancer effects in four different types of human colon cancer cell line, including Caco-2, DLD-1, HT-29 and HCT116. Additionally, MHY695 showed reduced cytotoxicity in NCM460, normal colonic epithelial cells. Furthermore, MHY-induced cytotoxicity in colon cancer cells was independent of the tumor suppressor protein p53. Collectively, these observations suggested that MHY695 may be a novel drug for the treatment of colon cancer.

Synthesis of pyrrolo[1,2-a]naphthyridines by Lewis acid mediated cycloisomerization

Functionalized pyrrolo[1,2-a]naphthyridines were synthesized by application of PtCl₂ and Bi(OTf)₃ as simple Lewis acids in a cycloisomerization reaction.

Carvacrol inhibits proliferation and induces apoptosis in human colon cancer cells

Colon cancer is one of the most common malignancies worldwide and has a high mortality rate. Carvacrol is a major component of oregano and thyme essential oils and shows antitumor properties. Here, we investigated the effects of carvacrol on the proliferation and apoptosis of two human colon cancer cell lines, HCT116 and LoVo, and studied the molecular mechanisms of its antitumor properties. We found that carvacrol inhibited the proliferation and migration of the two colon cancer cell lines in a concentration-dependent manner. Cell invasion was suppressed after carvacrol treatment by decreasing the expression of matrix metalloprotease-2 (MMP-2) and MMP-9. Carvacrol treatment also caused cell cycle arrest in the G2/M phase and decreased cyclin B1 expression. Finally, carvacrol induced cell apoptosis in a dose-dependent manner. At the molecular level, carvacrol downregulated the expression of Bcl-2 and induced the phosphorylation of the extracellular-regulated protein kinase and protein kinase B (p-Akt). In parallel, carvacrol upregulated the expression of Bax and c-Jun N-terminal kinase. These results indicate that carvacrol might induce apoptosis in colon cancer cells through the mitochondrial apoptotic pathway and the MAPK and PI3K/Akt signaling pathways. Together, our results suggest that carvacrol may have therapeutic potential for the prevention and treatment of colon cancer.

MHY-449, a novel dihydrobenzofuro[4,5-b][1,8]naphthyridin-6-one derivative, mediates oxidative stress-induced apoptosis in AGS human gastric cancer cells

MHY-449 is a novel dihydrobenzofuro[4,5-b][1,8]naphthyridin-6-one derivative designed and synthesized as a potential anticancer agent. The present study aimed to examine the anticancer activity and underlying mechanism of MHY-449. The cell viability assay performed in AGS human gastric carcinoma cells demonstrated that MHY-449 inhibited cell proliferation in a concentration-dependent manner. MHY-449 induced AGS cell death via apoptosis. The underlying molecular mechanism of MHY-449-mediated apoptosis was also investigated. MHY-449 promoted the upregulation of Fas and Fas-ligand, and activation of caspase-8, suggesting the involvement of a Fas-mediated extrinsic pathway in MHY-449-induced apoptosis. In addition, it was found that MHY-449-induced apoptosis was accompanied by the upregulation of Bax, p21(WAF1/CIP1), p27(KIP1), and p53 and suppression of Bcl-2. MHY-449 exposure activated the caspase cascade and subsequent poly(ADP-ribose) polymerase (PARP) cleavage. Furthermore, the pan-caspase inhibitor, Z-VAD-FMK, significantly attenuated MHY-449-induced apoptosis, indicating that the apoptosis was caspase-dependent. Moreover, the apoptogenic effect of MHY-449 was reactive oxygen species (ROS)-dependent. This result was confirmed by the induction of ROS by MHY-449 and by evidence that the scavenging of ROS by N-acetyl-L-cysteine inhibited MHY-449-induced cell death. Taken together, these results demonstrated that MHY-449 triggers apoptosis via caspase activation and ROS production. This result provides a novel mechanistic explanation and a basis for developing this compound as a novel candidate for human cancer therapy.

Resveratrol induces cell cycle arrest via a p53-independent pathway in A549 cells

Resveratrol, a non-flavone polyphenol compound, has a chemopreventive and chemotherapeutic effect against the progression of multiple types of cancer, including lung cancer. However, the molecular mechanism underlying the effects of resveratrol on cancer remain to be elucidated. In the present study, using an MTT assay, it was demonstrated that resveratrol inhibited cell proliferation in a concentration- and time-dependent manner. In addition, morphological features were observed in the A549, human lung cancer cell line, which included cell shrinkage, cells became distorted, certain cells became rounded and there was a concentration-dependent increase in the number of sloughed cells. Cell cycle analysis revealed that resveratrol may induce cell cycle arrest in the G₀/G₁ phase by downregulating the expression levels of cyclin D1, cyclin-dependent kinase (CDK)4 and CDK6, and upregulating the expression levels of the CDK inhibitors, p21 and p27. The immunofluorescence and western blot analysis results revealed that resveratrol upregulated the nuclear expression of p53 in A549 cells. Further studies have demonstrated that p53 downregulation did not contribute to the G₀/G₁ cell cycle arrest induced by resveratrol. In addition, resveratrol had no effect on the expression of p21, through use of the p53 inhibitor, pifithrin-α. The present study may offer a scientific basis for the further in-depth evaluation of resveratrol in the association of p53 and cell cycle arrest.

A novel hydroxamic acid derivative, MHY218, induces apoptosis and cell cycle arrest through downregulation of NF-κB in HCT116 human colon cancer cells

Colorectal cancer (CRC) is one of the most common malignant diseases and frequent cause of cancer deaths in the world. In spite of the significant advances in conventional therapeutic approaches to CRC, most patients ultimately die of their disease. There is a need to develop novel preventive approaches for this malignancy. This study was carried out to investigate the anticancer effect of MHY218, a hydroxamic acid derivative, in HCT116 human colon cancer cells. Treatment of cells with MHY218 resulted in growth inhibition and induction of apoptosis in a concentration-dependent manner. MHY218 induced G2/M phase arrest in the cell cycle progression which was observed by flow cytometry analysis, and a decrease in the protein expression of cyclin B1 and its activating partners Cdc25C and Cdc2. MHY218 also caused an increase in the expression levels of p21(WAF1/CIP1), a G2/M phase inhibitor, in a p53-independent pathway. The induction of apoptosis was observed by decreased viability, DNA fragmentation, cleavage of poly(ADP-ribose) polymerase, alteration in the ratio of Bax/Bcl-2 protein expression, and activation of caspase-3, -8 and -9. In addition, MHY218 treatment showed downregulation of the expression levels of the transcription factor nuclear factor-kappa B (NF-κB) in the nucleus, which has been reported to be implicated in the apoptotic cell death of several types of cancer cells, suppression of TNF-α-induced NF-κB activation, inhibition of cyclooxygenase-2 expression, repression of matrix metalloproteinase-9 activation and decrease of 5-lipoxygenase in a concentration-dependent manner. These results suggest that MHY218 may be a useful candidate to be used in the chemoprevention and/or treatment of colon cancer.