Identification of TBK1 inhibitors using a combination of pharmacophore- and machine learning-based approaches

The CHEMBL File containing RAW data of TBK-1 inhibition has been added to the github repository in asset folder. The code for making binary predictions has been deployed in the github link below: https://github.com/tanush84/TBK1-Binary_classification_Model.git The Link for the KCB database is https://chembank.org

Sinensetin Induces Autophagic Cell Death through p53-Related AMPK/mTOR Signaling in Hepatocellular Carcinoma HepG2 Cells

Sinensetin (SIN) has been reported to exhibit anti-inflammatory and anti-cancer activity. However, the cellular and molecular mechanism by which SIN promotes hepatocellular carcinoma (HCC) cell death remains unclear. In the present study, we investigated the induction of cell death by SIN and its underlying mechanism in HepG2 cells, an HCC cell line. We found that SIN significantly induced cell death in HepG2 cells, whereas the proliferation rate of Thle2, human liver epithelial cells, was unaffected by SIN. SIN-treated HepG2 cells were not affected by apoptotic cell death; instead, autophagic cell death was induced through the p53-mediated AMPK/mTOR signaling pathway. Inhibition of p53 degradation led to both autophagy and apoptosis in HepG2 cells. p53 translocation led to SIN-induced autophagy, whereas p53 translocation inhibited SIN-induced apoptosis. However, SIN showed apoptosis in the p53-mutant Hep3B cell line. Molecular docking simulation of the p53 core domain showed effective binding with SIN, which was found significant compared with the known p53 activator, RITA. Collectively, these data suggest that SIN may be a potential anti-cancer agent targeting autophagic cell death in human liver cancer

Scutellarein Induces Fas-Mediated Extrinsic Apoptosis and G2/M Cell Cycle Arrest in Hep3B Hepatocellular Carcinoma Cells

Scutellarein (SCU), a flavone found in the perennial herb Scutellaria baicalensis, is known for a wide range of biological activities. In the present study, we investigated the effects of treatment with SCU flavonoids on inducing apoptosis via the extrinsic pathway in Hep3B cells. SCU treatment significantly inhibited Hep3B cell proliferation and induced G2/M phase cell cycle arrest by inhibiting the expression level of the proteins Cdc25C, cdk1 and Cyclin B1. Allophycocyanin (APC)/Annexin V and propidium iodide (PI) double-staining showed upregulation of apoptotic cell death fraction. We further confirmed apoptosis by 4′-6-diamidino-2-phenylindole (DAPI) fluorescent staining and observed DNA fragmentation with agarose gel electrophoresis. Further, immunoblotting results showed that treatment with SCU showed no changes in Bax and Bcl-xL protein levels. In addition, SCU treatment did not affect the mitochondrial membrane potential (MMP) in Hep3B cells. On the contrary, treatment with SCU increased the expression of Fas and Fas ligand (FasL), which activated cleaved caspase-8, caspase-3, and polymeric adenosine diphosphate ribose (PARP), whereas the expression level of death receptor 4 (DR4) decreased. We confirmed that the proteins expressed upon treatment with SCU were involved in the Fas-mediated pathway of apoptosis in Hep3B cells. Thus, our findings in the current study strongly imply that SCU can be a basic natural source for developing potent anti-cancer agents for hepatocellular carcinoma (HCC) treatment

Poncirin Induces Apoptosis in AGS Human Gastric Cancer Cells through Extrinsic Apoptotic Pathway by up-Regulation of Fas Ligand

Poncirin, a natural bitter flavanone glycoside abundantly present in many species of citrus fruits, has various biological benefits such as anti-oxidant, anti-microbial, anti-inflammatory and anti-cancer activities. The anti-cancer mechanism of Poncirin remains elusive to date. In this study, we investigated the anti-cancer effects of Poncirin in AGS human gastric cancer cells (gastric adenocarcinoma). The results revealed that Poncirin could inhibit the proliferation of AGS cells in a dose-dependent manner. It was observed Poncirin induced accumulation of sub-G1 DNA content, apoptotic cell population, apoptotic bodies, chromatin condensation, and DNA fragmentation in a dose-dependent manner in AGS cells. The expression of Fas Ligand (FasL) protein was up-regulated dose dependently in Poncirin-treated AGS cells Moreover, Poncirin in AGS cells induced activation of Caspase-8 and -3, and subsequent cleavage of poly(ADP-ribose) polymerase (PARP). Inhibitor studies’ results confirm that the induction of caspase-dependent apoptotic cell death in Poncirin-treated AGS cells was led by the Fas death receptor. Interestingly, Poncirin did not show any effect on mitochondrial membrane potential (ΔΨm), pro-apoptotic proteins (Bax and Bak) and anti-apoptotic protein (Bcl-xL) in AGS-treated cells followed by no activation in the mitochondrial apoptotic protein caspase-9. This result suggests that the mitochondrial-mediated pathway is not involved in Poncirin-induced cell death in gastric cancer. These findings suggest that Poncirin has a potential anti-cancer effect via extrinsic pathway-mediated apoptosis, possibly making it a strong therapeutic agent for human gastric cancer

Pectolinarigenin Induced Cell Cycle Arrest, Autophagy, and Apoptosis in Gastric Cancer Cell via PI3K/AKT/mTOR Signaling Pathway

Pectolinarigenin (PEC), a natural flavonoid present in Cirsium chanroenicum and in some species of Citrus fruits, has various pharmacological benefits such as anti-inflammatory and anti-cancer activities. In the present study, we investigated the anti-cancer mechanism of PEC induced cell death caused by autophagy and apoptosis in AGS and MKN28 human gastric cancer cells. The PEC treatment significantly inhibited the AGS and MKN28 cell growth in a dose-dependent manner. Further, PEC significantly elevated sub-G1 phase in AGS cells and G2/M phase cell cycle arrest in both AGS and MKN28 cells. Apoptosis was confirmed by Annexin V and Hoechst 33342 fluorescent staining. Moreover, Immunoblotting results revealed that PEC treatment down-regulated the inhibitor of apoptosis protein (IAP) family protein XIAP that leads to the activation of caspase-3 thereby cleavage of PARP (poly-ADP-ribose polymerase) in both AGS and MKN28 cells in a dose-dependent manner. The autophagy-inducing effect was indicated by the increased formation of acidic vesicular organelles (AVOs) and increased protein levels of LC3-II conversion in both AGS and MKN28 cells. PEC shows the down regulation of PI3K/AKT/mTOR pathway which is a major regulator of autophagic and apoptotic cell death in cancer cells that leads to the down-regulation of p-4EBP1, p-p70S6K, and p-eIF4E in PEC treated cells when compared with the untreated cells. In conclusion, PEC treatment might have anti-cancer effect by down-regulation of PI3K/AKT/mTOR pathway leading to G2/M phase cell cycle arrest, autophagic and apoptotic cell death in human gastric cancer cells. Further studies of PEC treatment can support to develop as a potential alternative therapeutic agent for human gastric carcinoma

Comparative Proteomic Profiling of Tumor-Associated Proteins in Human Gastric Cancer Cells Treated with Pectolinarigenin

Pectolinarigenin (PEC), a natural flavonoid that is present in citrus fruits, has been reported to exhibit antitumor effects in several cancers. Though the mechanism of PEC-induced cytotoxicity effects has been documented, the proteomic changes that are associated with the cellular response to this flavonoid are poorly understood in gastric cancer cells. In this study, a comparative proteomic analysis was performed to identify proteins associated with PEC-induced cell death in two human gastric cancer cell lines: AGS and MKN-28. Two-dimensional gel electrophoresis (2-DE) revealed a total of 29 and 56 protein spots with significant alteration were screened in AGS and MKN-28 cells respectively. In total, 13 (AGS) and 39 (MKN28) proteins were successfully identified by mass spectrometry from the differential spots and they are known to be involved in signal transduction, apoptosis, transcription and translation, cell structural organization, and metabolism, as is consistent with multiple effects of PEC on tumor cells. Notably, novel target proteins like Probable ATP-dependent RNA helicase DDX4 (DDX4) and E3 ubiquitin-protein ligase LRSAM1 (LRSAM1) along with the commonly differential expressed proteins on both the cell lines that are treated with PEC were confirmed by immunoblotting. The DDX4 accelerates cell cycle progression by abrogating the G2 checkpoint when overexpressed in cancer cells, while the aberrant expression of LRSAM1 may be involved in the cancer pathology. Thus, proteomic analysis provides vital information about target proteins that are important for PEC-induced cell death in gastric cancer cells