Advanced tumors produce an excessive amount of transforming growth factor b (TGFb), which promotes tumor progression at late stages of malignancy. The purpose of this study was to develop anti-TGFb therapeutics for cancer. We synthesized a novel small-molecule TGFb receptor I kinase (activin receptorlike kinase 5) inhibitor termed N- [[4-([1,2,4], and we investigated its potential antimetastatic efficacy in mouse mammary tumor virus (MMTV)/c-Neu mice and 4T1 orthotopic-grafted mice. EW-7197 inhibited Smad/ TGFb signaling, cell migration, invasion, and lung metastasis in MMTV/c-Neu mice and 4T1 orthotopicgrafted mice. EW-7197 also inhibited the epithelial-to-mesenchymal transition (EMT) in both TGFb-treated breast cancer cells and 4T1 orthotopic-grafted mice. Furthermore, EW-7197 enhanced cytotoxic T lymphocyte activity in 4T1 orthotopic-grafted mice and increased the survival time of 4T1-Luc and 4T1 breast tumorbearing mice. In summary, EW-7197 showed potent in vivo antimetastatic activity, indicating its potential for use as an anticancer therapy.

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These results suggest that HAL-FLU or HAL-SID sensitization in KBV20C cells involves both cytotoxic and P-gp inhibitory effects, whereas HAL-DON sensitization may involve only P-gp inhibitory activity of DON.

We previously discovered a novel sirtuin (SIRT) inhibitor, MHY2256, that exerts anticancer activity through p53 acetylation in MCF-7 human breast cancer cells. We investigated the anticancer activity of MHY2256 against hormone-related cancer, an endometrial cancer with a poor prognosis. The IC50 values of MHY2256 were shown to be much lower than those of salermide, a well-known SIRT inhibitor. Furthermore, MHY2256 significantly reduced the protein expression and activities of SIRT1, 2, and 3, with similar effects to salermide. Particularly, MHY2256 markedly inhibited tumor growth in a tumor xenograft mouse model of Ishikawa cancer cells. During the experimental period, there was no significant change in the body weight of mice treated with MHY2256. A detailed analysis of the sensitization mechanisms of Ishikawa cells revealed that late apoptosis was largely increased by MHY2256. Additionally, MHY2256 increased G1 arrest and reduced the number of cell cyclic-related proteins, suggesting that apoptosis by MHY2256 was achieved by cellular arrest. Particularly, p21 was greatly increased by MHY225656, suggesting that cell cycle arrest by p21 is a major factor in MHY2256 sensitization in Ishikawa cells. We also detected a significant increase in acetylated p53, a target protein of SIRT1, in Ishikawa cells after MHY2256 treatment. In a mouse xenograft model, MHY2256 significantly reduced tumor growth and weight without apparent side effects. These results suggest that MHY2256 exerts its anticancer activity through p53 acetylation in endometrial cancer and can be used for targeting hormone-related cancers.

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Clinically relevant sirtuin (SIRT) inhibitors may possess antitumor activities. A previous study indicated that 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) exhibited potent anticancer activity by SIRT1 inhibition. Therefore, the aim of the present study was to investigate whether its derivatives (J11-C1 and J19) exhibited anticancer activity against ovarian cancer SKOV3 cells. Cell viability was determined using an MTT assay. Cell cycle arrest, apoptosis and autophagy were determined using flow cytometry or western blot analysis. J11-Cl and J19 were less cytotoxic to SKOV3 cells compared with 15d-PGJ2. Molecular docking studies supported the interactions of 15d-PGJ2, J11-Cl and J19 with various amino acids in SIRT1 proteins. Similar to 15d-PGJ2, J11-C1 and J19 inhibited SIRT1 enzymatic activity and decreased SIRT1 expression levels in a concentration-dependent manner. J11-C1 induced apoptotic cell death more effectively compared with J19, which was associated with markedly decreased expression of the anti-apoptotic molecule B-cell lymphoma 2 (Bcl-2). Furthermore, the levels of light chain 3-II (LC3-II) and beclin-1 were clearly induced in SKOV3 cells treated with J11-Cl. Thus, 15d-PGJ2 and its derivatives exhibited anticancer activity possibly by inducing apoptotic or autophagic cell death pathways. Collectively, the results of the present study suggest that 15d-PGJ2 and its derivatives exerted antitumor activity by selectively modulating the expression of genes associated with cell cycle arrest, apoptosis and autophagy. Notably, J11-C1 is a novel candidate SIRT1 inhibitor with anticancer activity.

Emerging evidence indicates that the activity of pyruvate kinase M2 (PKM2) isoform is crucial for the survival of tumor cells. However, the molecular mechanism underlying the function of PKM2 in renal cancer is undetermined. Here, we reveal the overexpression of PKM2 in the proximal tubule of renal tumor tissues from 70 cases of patients with renal carcinoma. The functional role of PKM2 in human renal cancer cells following small-interfering RNA-mediated PKM2 knockdown, which retarded 786-O cell growth was examined. Targeting PKM2 affected the protein kinase B (AKT)/mechanistic target of the rapamycin 1 (mTOR) pathway, and downregulated the expression of glycolytic enzymes, including lactate dehydrogenase A and glucose transporter-1, and other downstream signaling key proteins. PKM2 knockdown changed glycolytic metabolism, mitochondrial function, adenosine triphosphate (ATP) level, and intracellular metabolite formation and significantly reduced 786-O cell migration and invasion. Acridine orange and monodansylcadaverine staining, immunocytochemistry, and immunoblotting analyses revealed the induction of autophagy in renal cancer cells following PKM2 knockdown. This is the first study to indicate PKM2/AKT/mTOR as an important regulatory axis mediating the changes in the metabolism of renal cancer cells.