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The STE20 kinase family is a complex signalling cascade that regulates cytoskeletal organisation and modulates the stress response. This signalling cascade includes various kinase mediators, such as TAOK1 and MAP4K5. The dysregulation of the STE20 kinase pathway is linked with cancer malignancy. A small-molecule inhibitor targeting the STE20 kinase pathway has therapeutic potential. In this study, a structure-based virtual screening (SBVS) approach was used to identify potential dual TAOK1 and MAP4K5 inhibitors. Enzymatic assays confirmed three potential dual inhibitors (>50% inhibition) from our virtual screening, and analysis of the TAOK1 and MAP4K5 binding sites indicated common interactions for dual inhibition. Compound 1 revealed potent inhibition of colorectal and lung cancer cell lines. Furthermore, compound 1 arrested cancer cells in the G0/G1 phase, which suggests the induction of apoptosis. Altogether, we show that the STE20 signalling mediators TAOK1 and MAP4K5 are promising targets for drug research.

Tamoxifen is a widely known estrogen receptor (ER) modulator which has been employed in adjuvant treatment of ER+ breast cancer for over 30 years. Interestingly, clinical observations reveal that tamoxifen is capable of inducing regression of some tumors lacking ER expression whereas tamoxifen is also capable of increasing host resistance against cancer in an ER-independent mechanism. These findings suggest the immunomodulatory effects of tamoxifen may be ER-independent, but little is known about the underlying mechanism and the potential clinical implication. Recently, we identified a novel mechanism by which tamoxifen exerts its DNA-damaging potential by re-shaping the unfavorable tumor microenvironment in breast cancer. A long-term tamoxifen administration induces downregulation of the chromatin ‘‘reader’’ RACK7/ZMYND8, which acts as a suppressor of interferon-stimulated genes (ISGs, including cytokines and chemokines) and CEACAM1 in both ER+ and triple negative breast cancer (TNBC) cells. To investigate the immunomodulatory effects of tamoxifen in conjunction with RACK7-knockdown, the orthotopic murine TNBC 4T1 model was employed to investigate tamoxifen-mediated cellular modulation in TNBC. The control and RACK7-knockdown 4T1 cells are orthotopically implanted into the mammary fat pad of female BALB/c mice. Peripheral cytokines/chemokines and high-content biomarker studies (multiplex immunoassays, flow cytometry, and single-cell RNA sequencing) are deployed to obtain insights into the mechanistic rationale behind the immunomodulatory effects of tamoxifen and/or RACK7-knockdown. The tamoxifen-mediated cellular modulation evokes cytokine/chemokine secretion and further induces T-cell infiltration into tumor area. However, tumor reduction was limited due to extensive T-cell exhaustion from interaction of CEACAM1 and TIM-3, a “checkpoint” receptor expressed in CD4+ and CD8+ T cells. The expression patterns of CEACAM1 and PD-L1 in 4T1 tumor cells and that of TIM-3 and PD-1 in CD4+ and CD8+ T-cells correlate with intra-tumor infiltration of T-cells and tumor cell growth. Therefore, targeting the interaction between CEACAM1 and TIM-3 to overcome T-cell exhaustion is crucial for the new therapeutic role of tamoxifen treatment in TNBC breast cancer in conjugation with RACK7-knockdown. Altogether, our findings provide direct evidence to support a new therapeutic opportunity by targeting CEACAM1-TIM-3 interaction in the tamoxifen-mediated tumor immune microenvironment for improving immune checkpoint blockade therapy in breast cancer. Citation Format: Pony Yu-Ling Lee, Marvin A. Aberin, Chien-Chang Shen, Kun-Yuan Lin, Chao Di Chang, Chih-Chieh Yang, Shan-Yun Cheng, Ya Wen Hung, Xin-Guo Hsu, Shu-Ping Wang. Reshaping the tumor microenvironment: new application of tamoxifen in triple negative breast cancer immunomodulation. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5953.

The Astragalus membranaceus polysaccharides (APS) can improve immunity and enhance treatment reactions. This study analyzed the effects of effective antivascular endothelial growth factor (anti-VEGF) antibody production in mice treated with APS. After APS treatment, the serum of mice produced the antibody reactions that can cross-validate VEGF. The isolated single-chain fragment variable (scFv) antibodies could neutralize VEGF and inhibit in vivo tumor growth. Of the scFvs, scFv 4E can significantly compete the interaction of bevacizumab with VEGF. In cell experiments, scFv 4E effectively inhibited human umbilical vein endothelial cells induced by VEGF in vitro. In a matrix gel-assisted angiogenesis model, scFv 4E significantly inhibited angiogenesis reactions. In addition, in a xenograft model established in the colorectal cancer cell strain HCT116, scFv 4E treatment inhibited tumor growth by up to 52.7%. Finally, molecule docking was performed to simulate the complex interactions of scFv 4E and VEGF, the main driving forces of which involve the hydrophobic interactions and hydrogen bonds of Tyr108 and Tyr 109 of the complementarity-determining region H3 loop with VEGF. The results help in establishing antibody library with high diversity for selecting antibodies with specificity. In addition, this study indirectly expounded the correlations of APS enhancing immunity regulation in vivo.

This study reports the synthesis of a series of 2-aroylisoindoline hydroxamic acids employing N-benzyl, long alkyl chain and acrylamide units as diverse linkers. In-vitro studies led to the identification of N-benzyl linker-bearing compound (10) and long chain linker-containing compound (17) as dual selective HDAC6/HSP90 inhibitors. Compound 17 displays potent inhibition of HDAC6 isoform (IC50 = 4.3 nM) and HSP90a inhibition (IC50 = 46.8 nM) along with substantial cell growth inhibitory effects with GI50 = 0.76 μM (lung A549) and GI50 = 0.52 μM (lung EGFR resistant H1975). Compound 10 displays potent antiproliferative activity against lung A549 (GI50 = 0.37 μM) and lung H1975 cell lines (GI50 = 0.13 μM) mediated through selective HDAC6 inhibition (IC50 = 33.3 nM) and HSP90 inhibition (IC50 = 66 nM). In addition, compound 17 also modulated the expression of signatory biomarkers associated with HDAC6 and HSP90 inhibition. In the in vivo efficacy evaluation in human H1975 xenografts, 17 induced slightly remarkable suppression of tumor growth both in monotherapy as well as the combination therapy with afatinib (20 mg/kg). Moreover, compound 17 could effectively reduce programmed death-ligand 1 (PD-L1) expression in IFN-γ treated lung H1975 cells in a dose dependent manner suggesting that dual inhibition of HDAC6 and HSP90 can modulate immunosuppressive ability of tumor area.

Background Oncogenic K-Ras signaling highly relies on the canonical Ras/MEK/ERK pathway to contribute to pancreatic cancer progression. However, numerous efforts of MEK inhibitors have failed to provide an optimal antitumor effect for pancreatic cancer in practice. The aim of the present work was to develop a more efficacious therapeutic intervention for MEK inhibitors through combination with histone deacetylase (HDAC) inhibitor MPT0E028. Methods The effects of combined therapy on cell viability, apoptosis, protein, and RNA expressions were determined by MTT assay, flow cytometry, western blotting, and quantitative PCR analysis. The AsPC-1 xenograft was used to assess antitumor effects in vivo. Results The co-administration of MPT0E028 and MEK inhibitor yielded synergistic effects on cell viability suppression both in K-Ras mutated and wild-type pancreatic cancer cells and also markedly triggered cell apoptosis. Surprisingly, ERK and epidermal growth factor receptor (EGFR) were activated by the long-term and low-concentration treatment of MPT0E028 or another HDAC inhibitor alone. Whereas, the pharmacological attenuation of ERK signaling dramatically abolished the MPTE028-induced p-ERK and EGFR expression. Overexpression of HDAC4, HDAC6, and MEK, respectively, reversed the cell death induced by the combined treatment. Finally, the combined treatment decreased the tumor volume in an AsPC-1 xenograft model compared to each individual treatment alone. Conclusions The synergistic anti-survival effect of the combination was suggested to occur via compensation of the MEK inhibitor for activated ERK. Our results indicate that this combination strategy could benefit patients with pancreatic cancer beyond K-Ras status. Electronic supplementary material The online version of this article (10.1186/s13148-019-0681-6) contains supplementary material, which is available to authorized users.

Table S1. IC50 of MPT0E028 and SAHA in pancreatic cell lines. AsPC-1, PANC-1, and BxPC-3 cells were treated with different concentrations of MPT0E028 or SAHA for 72â h. IC50 (the half maximal inhibitory concentration) was determined by MTT assay. (DOCX 12 kb)

Lipid-binding proteinsjoin many important biological processes. Lipid-binding proteins are highly related to diseases, such as metabolic diseases, cancer and autoimmune diseases. The existed studies of predictinglipid-binding functions or predictinglipid-binding sites, but notidentify the lipid-binding proteins ornot lipid-binding proteins.This study purpose a systematic approach to identify a small set of physicochemical and biochemical properties in AAindex database to design support vector machine (SVM) based classifier for predicting and analyzing lipid-binding proteins. The merits of this study are three-fold: First, we establish a data set of lipid-binding proteins collected from SwissProt utilizing the gene ontology (GO) annotation terms. Secondly, utilize an efficient genetic algorithm based optimization method IBCGA to select an informative set of feature vectors of representing sequences from the viewpoint of machine learning. Thirdly, analyze the selected feature vectors to identify the related physicochemical properties which may affect the binding mechanism oflipid-binding proteins. In this study, to overcome the unbalanced dataset problem caused from the number of putative negative dataset (537,346) being almost 530 times to that of positive dataset (1,053), a dataset determining technique is proposed.Then the dataset is applied to make a high performance classifier. The prediction accuracy of independent test is 77.75% using 18 properties. The selected 18 properties may divide into 6 groupings:alpha and turn propensities, beta propensity, Composition, Hydrophobicity, Physicochemical properties and other properties.Hydrophobicity and alpha-helix are most relative to lipid-binding protein.