Expression data from mouse colon tissue in activated T cell transfer colitis model treated with MEK inhibitor or anti-TNFa antibody
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ABSTRACT: We analyzed publicly available mucosal gene expression data from Crohn's disease (CD) patients pre- and post-infliximab therapy and found that a series of gene expression signature that remains abnormal even if patients achieve clinical remission. Using CMap approach to discover novel therapeutic target for untreatable mechanism of anti-TNFa mAb therapy, we have identified MEK inhibitor exhibiting negatively-correlated effects on reference signature match infliximab therapy untreatable signature. Our findings provide the rationale for testing MEK inhibitor to identify a novel mechanism of action for CD. Using an activated T cell trasnfer colitis model, a highly selective MEK inhibitor showed therapeutic efficacy and improved the histological changes. To dissect molecular mechanisms, we performed global gene expression profile by RNA-sequencing on the Ion Torrent platform to identify broad scale changes in gene expression treated with MEK inhibitor compared to anti-TNFa mAb.
Project description:We analyzed publicly available mucosal gene expression data from Crohn's disease (CD) patients pre- and post-infliximab therapy and found that a series of gene expression signature that remains abnormal even if patients achieve clinical remission. Using CMap approach to discover novel therapeutic target for untreatable mechanism of anti-TNFa mAb therapy, we have identified MEK inhibitor exhibiting negatively-correlated effects on reference signature match infliximab therapy untreatable signature. Our findings provide the rationale for testing MEK inhibitor to identify a novel mechanism of action for CD. Gene expression profile was performed to analyze the gene modulation induced by a highly selective MEK inhibitor, and to evaluate whether it normalized reference residual CD signature in vitro.
Project description:Infliximab, an anti-TNFa monoclonal antibody, is an effective treatment for ulcerative colitis (UC) inducing over 60% of patients to respond to treatment. Consequently, about 40% of patients do not respond. This study analyzed mucosal gene expression from patients enrolled in ACT1 to provide a predictive response signature for infliximab treatment. Keywords: predictive response signature
Project description:Infliximab, an anti-TNFa monoclonal antibody, is an effective treatment for ulcerative colitis (UC) inducing over 60% of patients to respond to treatment. Consequently, about 40% of patients do not respond. This study analyzed mucosal gene expression from patients enrolled in ACT1 to provide a predictive response signature for infliximab treatment. Experiment Overall Design: Twenty-two patients underwent colonoscopy with biopsy before infliximab treatment. Response to infliximab was defined as endoscopic and histologic healing at week 8 (P2, 5, 9, 10, 14, 15, 16, 17, 24, 27, 36, and 45 as responders; P3, 12, 13, 19, 28, 29, 32, 33, 34, and 47 as non-responders). Messenger RNA was isolated from pre-infliximab biopsies, labeled and hybridized to Affymetrix HGU133Plus_2.0 Array. The predictive response signature was verified by an independent data set.
Project description:Objective: A subset of Crohns disease (CD) patients experiences long-term remission after infliximab withdrawal. Biomarkers are needed to identify those patients.Design: New biomarkers of relapse were searched in the baseline serum of CD patients stopping infliximab when they were under combined therapy (antimetabolite and infliximab) and stable clinical remission (STORI cohort, n=102). From shotgun proteomics experiment (discovery step), biomarker candidates were identified and further targeted by selected reaction monitoring (verification step). The dataset was stratified to search for markers of short- (<6 months) or long-term relapse (>6 months). The risk of relapse and the predicting capacity associated with biomarker candidates were evaluated using univariate Cox model and log-rank statistic, respectively. To test their complementary predicting capacity, biomarker candidates were systematically combined in pairs. Results: Distinct biomarker candidates were associated with the risk (hazard ratio: HR) of short- (15 proteins, 2.9<HR<16.1, p<0.05) and long-term (17 proteins, 2<HR<4.4, p<0.05) relapse, they reflect different pathophysiological processes. In stratified and non-stratified datasets, novel marker combinations exhibited a high predicting capacity as shown by their higher Z-scores (FDR<0.001) than CRP and faecal calprotectin (current references in predicting relapse). Conclusion: We identified for the first time circulating biomarker candidates associated with the risk of long-term relapse in CD patients stopping infliximab. We also highlight a sequence of pathophysiological processes leading to relapse, this could help to better understand the disease progression. Our findings may pave the way for a better non-invasive evaluation of the risk of relapse when contemplating anti-TNFα withdrawal in CD patients.
Project description:Mitogen-activated protein kinases (MEK 1/2) are central components of the RAS signaling pathway and attractive targets for cancer therapy. However, PIK3CA mutation, which commonly co-occurs with KRAS mutation, offered resistance to MEK inhibitor through activation of PI3K-AKT signaling. We identified a gene that cooperates with MEK inhibitors to forcefully treat PIK3CA mutant colon cancer cells. -catenin, a key molecule of the WNT pathway, emerged as a candidate by protein/Ab Chip array. MEK inhibitor treatment led to a decrease in -catenin in PIK3CA wild-type colon cancer cells but not in PIK3CA mutant colon cancer cells. Tumor regression was promoted by a combination of MEK inhibitor and NVP-TNS656, which targets the WNT pathway. Furthermore, combined inhibition of MEK and -catenin by NVP-TNS656 promoted tumor regression in colon cancer patient-derived xenograft (PDX) models expressing mutant PIK3CA. Taken together, we propose that inhibition of the WNT pathway, particularly -catenin, may bypass resistance to MEK inhibitor in human PIK3CA mutant colon cancer. Additionally, -catenin is a potential PD marker of MEK inhibitor resistance. In the study, we identified and evaluated biomarker for response to MEK inhibitor on colon cancer cells.
Project description:The expression of Triggering Receptor Expressed on Myeloid cells (TREM)-1 has been described as a predictive marker for anti-Tumor Necrosis Factor (TNF)-α monoclonal antibody (mAb) therapy responsiveness in patients with inflammatory bowel disease (IBD). Here we investigated expression of TREM-1 specifically in CD14+ monocytes in relation to anti-TNF response. The pretreatment TREM-1 expression levels of CD14+ monocytes of Crohn’s disease (CD) patients were predictive of outcome to anti-TNF mAb therapy, with low TREM-1 expression associated with response to anti-TNF. FACSorting of CD14+ monocytes with different TREM-1 levels showed that differentiation towards regulatory CD206+ M2 type macrophages by anti-TNF was suppressed in CD14+ monocytes with high TREM-1 expression. Activity of the Fcγ-Receptor and autophagy pathway, both necessary for M2 type differentiation and the response to anti-TNF, were decreased in CD14+ monocytes with high expression of TREM-1. We confirmed that the activity of the Fcγ-Receptor pathway was decreased in the CD patients that did not respond to anti-TNF therapy and that it was negatively correlated with TREM-1 expression levels in the CD patient cohort. In conclusion, our results indicate that TREM-1 expression levels in CD14+ monocytes associate with decreased autophagy and FcγR activity resulting in decreased differentiation to M2 type regulatory macrophages upon anti-TNF mAb treatment, which may explain anti-TNF non-response in IBD patients with high expression levels of TREM-1.
Project description:Through a genetic screen in BRAF mutant tumor cells, we show that the Hippo pathway effector YAP acts as a parallel survival input to promote resistance to RAF-MEK inhibitor therapy. Our data uncover YAP as a novel mechanism of resistance to RAF-MEK targeted therapy. The findings unveil the synthetic lethality of YAP and RAF-MEK co-suppression as a promising strategy to enhance response and patient survival.
Project description:Mycobacterium abscessus (Mab) causes serious infections that often require over 18 months of antibiotic combination therapy. With β lactam antibiotics being safe, double β-lactam and β-lactam/β-lactamase inhibitor combinations are of interest for improving treatment of Mab infections and minimizing toxicity. However, a mechanistic approach for building these combinations is lacking since little is known about which penicillin-binding protein (PBP) target receptors are inactivated by different β-lactams in Mab. This project aimed to identify PBPs in Mab and study the binding affinities of each of these PBPs with β-lactam antibiotics. These first PBP occupancy patterns in Mab provide a mechanistic foundation for selecting and optimizing safe and effective combination therapies with β-lactams.
Project description:Mitogen-activated protein kinases (MEK 1/2) are central components of the RAS signaling pathway and attractive targets for cancer therapy. However, PIK3CA mutation, which commonly co-occurs with KRAS mutation, offered resistance to MEK inhibitor through activation of PI3K-AKT signaling. We identified a gene that cooperates with MEK inhibitors to forcefully treat PIK3CA mutant colon cancer cells. -catenin, a key molecule of the WNT pathway, emerged as a candidate by protein/Ab Chip array. MEK inhibitor treatment led to a decrease in -catenin in PIK3CA wild-type colon cancer cells but not in PIK3CA mutant colon cancer cells. Tumor regression was promoted by a combination of MEK inhibitor and NVP-TNS656, which targets the WNT pathway. Furthermore, combined inhibition of MEK and -catenin by NVP-TNS656 promoted tumor regression in colon cancer patient-derived xenograft (PDX) models expressing mutant PIK3CA. Taken together, we propose that inhibition of the WNT pathway, particularly -catenin, may bypass resistance to MEK inhibitor in human PIK3CA mutant colon cancer. Additionally, -catenin is a potential PD marker of MEK inhibitor resistance.