mTOR-independent 4E-BP1 phosphorylation is associated with cancer resistance to mTOR kinase inhibitors

ATP -competitive mTO R kinase inhibitors (mTorKIs) are a new generation of mTO R-targeted agents with more potent anticancer activity than rapamycin in several tumor models. However, the sensitivity and resistance of cancer cells to mTorKIs remain poorly understood. In this study, we tested mTorKIs against a large panel of colorectal cancer (CRC) cell lines, and found that mTorKIs displayed broader anti-CRC activity than rapamycin, including CRC cells with K-Ras or B-Raf mutations, suggesting that these mTorKIs are particularly useful for CRCs resistant to EGFR inhibitors. Unexpectedly, we found that 40% CRC cell lines were intrinsically drug resistant. Moreover, we discovered an mTO R-independent 4E? BP1 phosphorylation that was correlated with mTorKI resistance. Altogether, our findings provide compelling preclinical support for testing mTorKIs in human CRC clinical trials. They further reveal the existence of significant intrinsic mTorKI drug resistance in cancer cells and suggest that 4E-BP1 phosphorylation is a predictive biomarker for mTorKI sensitivity and resistance.     

Novel cinnamaldehyde-based aspirin derivatives for the treatment of colorectal cancer

Colorectal cancer (CRC) is a leading cause of mortality worldwide. Current treatments of CRC involve anti-cancer agents with relatively good efficacy but unselectively target both cancer and non-cancer cells. Thus, there is a need to discover and develop novel CRC therapeutics that have potent anti-cancer effects, but show reduced off-target cell effects. Here, a novel series of cinnamaldehyde-based aspirin derivatives were designed and synthesized. Biological evaluation indicated that the most active compound 1f exhibited more than 10-fold increase in the anti-proliferation efficacy in HCT-8 cells compared to the parent compounds. Its effects were similarly reproduced in another CRC cell line, DLD-1, but with 7- to 11-fold less inhibitory activity in non-tumorigenic colon cells. Flow cytometry analysis showed that 1f induced cell cycle arrest and apoptosis, which was further validated with immunoblot analysis of the relative protein levels of cleaved caspase 3 and PARP as well as the ROS production in CRC cells. More so, 1f significantly inhibited the growth of implanted CRC in vivo in mouse xenograft model. Taken together, our results show that cinnamaldehyde-based aspirin derivatives such as 1f show promise as novel anti-CRC agent for further pharmaceutical development.     

mTOR-independent 4E-BP1 phosphorylation is associated with cancer resistance to mTOR kinase inhibitors

ATP-competitive mTOR kinase inhibitors (mTorKIs) are a new generation of mTOR-targeted agents with more potent anticancer activity than rapamycin in several tumor models. However, the sensitivity and resistance of cancer cells to mTorKIs remain poorly understood. In this study, we tested mTorKIs against a large panel of colorectal cancer (CRC) cell lines, and found that mTorKIs displayed broader anti-CRC activity than rapamycin, including CRC cells with K-Ras or B-Raf mutations, suggesting that these mTorKIs are particularly useful for CRCs resistant to EGFR inhibitors. Unexpectedly, we found that 40% CRC cell lines were intrinsically drug resistant. Moreover, we discovered an mTOR-independent 4E-BP1 phosphorylation that was correlated with mTorKI resistance. Altogether, our findings provide compelling preclinical support for testing mTorKIs in human CRC clinical trials. They further reveal the existence of significant intrinsic mTorKI drug resistance in cancer cells and suggest that 4E-BP1 phosphorylation is a predictive biomarker for mTorKI sensitivity and resistance.Key words: mTOR, kinase, colorectal cancer, drug resistance, 4E-BP1, phosphorylation     

Anti-colorectal cancer targets of resveratrol and biological molecular mechanism: Analyses of network pharmacology,human and experimental data

In this study, colorectal cancer (CRC)-diseased targets and resveratrol (Res)-associated targets were combined and constructed by the use of grouped databases for identification of the predicted targets. After production of target-functional protein interaction network of Res anti-CRC, the topological analysis was used to create the core targets of Res anti-CRC. All core targets performed the analyses of biological function and pathway enrichment to optimize the biological processes and key signaling pathways of Res anti-CRC. The resultant five core therapeutic targets of Res anti-CRC were identified as protein kinase B1 (AKT1), interleukin 6 (IL6), Tumor protein p53 (TP53), vascular endothelial growth factor, and mitogen-activated protein kinase 1, respectively. Biological processes of Res anti-CRC were predominantly associated with regulating apoptosis, immune response, cellular communication, signal transduction, and metabolism of the nuclide. In addition, the top 10 key signaling pathways were identified, respectively. In human CRC sample assays, CRC histologic sections showed elevated expression of AKT1 and IL6 proteins, accompanied with abnormal changes in blood molecules. In pharmacological experiments of Res anti-CRC in vitro, Res-treated HCT116 cells showed inhibited cell growth, induced cell death. In addition, downregulation of intracellular AKT1 and IL6 expression were checked in Res-treated HCT116 cells. Taken together, these bioinformatic findings and preliminary validated data uncovered pharmacological molecular mechanisms associated with Res anti-CRC, and further identified top five core therapeutic targets. Beneficially, these five predicted targets might serve as potential biomolecules for anti-CRC treatment.     

Grouped-seq for integrated phenotypic and transcriptomic screening of patient-derived tumor organoids

Patient-derived tumor organoids (PDOs) have emerged as a reliable in vitro model for drug discovery. However, RNA sequencing-based analysis of PDOs treated with drugs has not been realized in a high-throughput format due to the limited quantity of organoids. Here, we translated a newly developed pooled RNA-seq methodology onto a superhydrophobic microwell array chip to realize an assay of genome-wide RNA output unified with phenotypic data (Grouped-seq). Over 10-fold reduction of sample and reagent consumption together with a new ligation-based barcode synthesis method lowers the cost to ∼$2 per RNA-seq sample. Patient-derived colorectal cancer (CRC) organoids with a number of 10 organoids per microwell were treated with four anti-CRC drugs across eight doses and analyzed by the Grouped-seq. Using a phenotype-assisted pathway enrichment analysis (PAPEA) method, the mechanism of actions of the drugs were correctly derived, illustrating the great potential of Grouped-seq for pharmacological screening with tumor organoids.     

Potent anti-prostate cancer agents derived from a novel androgen receptor down-regulating agent

The search for novel androgen receptor (AR) down-regulating agents by catalyst HipHop pharmacophore modeling led to the discovery of some lead molecules. Unexpectedly, the effect of these leads on human prostate cancer LNCaP cell viability did not correlate with the ability of the compounds to cause down-regulation of AR protein expression. Through rational synthetic optimization of the lead compound (BTB01434), we have discovered a series of novel substituted diaryl molecules as potent anti-prostate cancer agents. Some compounds (1-6) were shown to be extremely potent inhibitors of LNCaP cell viability with GI(50) values in the nanomolar range (1.45-83 nM). The most potent compound (4-methylphenyl)[(4-methylphenyl)sulfonyl]amine (5) with a GI(50) value of 1.45 nM is 27,000 times more potent than our lead compound BTB01434 (GI(50)=39.8 microM). In addition, some of the compounds exhibited modest anti-androgenic activities and one was also a potent inhibitor (GI(50)=850 nM) of PC-3 (AR-null) cell growth. A clear structure-activity relationship (SAR) has been established for activity against LNCaP cells, where potent molecules possess two substituted/unsubstituted aromatic rings connected through a sulfonamide linker. These novel compounds are strong candidates for development for the treatment of hormone-sensitive and importantly hormone-refractory prostate cancers in humans.     

Design,synthesis, and evaluation of novel coumarin-dithiocarbamate derivatives (IDs) as anti-colorectal cancer agents

Colorectal cancer (CRC) is a common malignant tumour of human digestive tract. The high mortality rate of CRC is closely related to the limitations of existing treatments. Thus, there is an urgent need to search for new anti-CRC agents. In this work, twenty novel coumarin-dithiocarbamate derivatives (IDs) were designed, synthesized and evaluated in vitro. The results suggest that the most active compound ID-11 effectively inhibited the proliferation of CRC cell lines while shown little impact on normal colon epithelial cells. Mechanism studies revealed that ID-11 displayed bromodomain-containing protein 4 inhibitory activity, and induced G2/M phase arrest, apoptosis as well as decreased the expression levels of the key genes such as c-Myc and Bcl-2 in CRC cell lines. Moreover, the ADMET properties prediction results shown that ID-11 possess well metabolic characteristics without obvious toxicities. Our data demonstrated that compound ID-11 may be a promising anti-CRC agent and deserved for further development.