Project description:Metastatic colorectal carcinoma is one of the most common cancers in the world, second most commonly diagnosed cancer in Europe. Approximately 25% of patients initially diagnosed with colorectal carcinoma have metastases at the time of the first diagnosis and almost 50% of the diagnosed patients develop metastases, which explains the high mortality rate of these tumors. The carcinogenic process can be inhibited by the inactivation of EGFR receptors, making them important therapeutic targets. However, around 90-80% of patients do not respond to the EGFR targeted therapy. Resistance is mainly due to KRAS gene mutations. In this study, we built a 171 mutations panel (OncoAlvo®) that screens all mutations recommended by the ESMO, ASCO & NICE Medical Guidelines with 99% accuracy. The samples were simultaneously genotyped by other techniques to validate our panel and accuracy.
Project description:Monoclonal antibodies targeting the Epidermal Growth Factor Receptor (EGFR), such as cetuximab and panitumumab, have evolved to important therapeutic options in metastatic colorectal cancer (CRC). However, almost all patients with clinical response to anti-EGFR therapies show disease progression within a few months and little is known about mechanism and timing of resistance evolution. Here we performed whole genome sequencing of plasma DNA (plasma-Seq) from patients treated with anti-EGFR therapy. We demonstrate that development of resistance to anti-EGFR therapies is frequently associated with focal amplifications of KRAS, MET, and ERBB2. However, we also show that focal KRAS amplifications can be acquired in tumor genomes of patients under cytotoxic chemotherapy. Furthermore, we provide evidence that specific chromosomal polysomies, such as overrepresentations of 12p and 7p, harboring KRAS and EGFR, respectively, determine responsiveness to anti-EGFR therapy. In contrast, employing ultra-sensitive deep sequencing of genes associated with anti-EGFR resistance, such as KRAS, BRAF, PIK3CA, and EGFR, we did not observe the occurrence of novel, acquired mutations. Overall, whole-genome plasma DNA sequencing represents a non-invasive blood-based surrogate measure of changes in tumors. As such, plasma-Seq enables the identification of novel mutant clones and may therefore facilitate early adjustments of therapies that may delay or prevent disease progression.
Project description:Purpose: Accumulating analyses of pro-oncogenic molecular mechanisms triggered a rapid development of targeted cancer therapies. Although many of these treatments produce impressive initial responses, eventual resistance onset is practically unavoidable. One of the main approaches for preventing this refractory condition relies on the implementation of combination therapies. This includes dual-specificity reagents that affect both of their targets with a high level of selectivity. Unfortunately, selection of target combinations for these treatments is often confounded by limitations in our understanding of tumor biology. Here, we describe and validate a multipronged unbiased strategy for predicting optimal co-targets for bispecific therapeutics. Experimental design: Our strategy integrates ex-vivo genome-wide loss of function screening, BioID interactome profiling and gene expression analysis of patient data to identify the best fit co-targets. Final validation of selected target combinations is done in tumorsphere cultures and xenograft models. Results: Integration of our experimental approaches unambiguously pointed towards EGFR and EPHA2 tyrosine kinase receptors as molecules of choice for co-targeting in multiple tumor types. Following this lead, we generated a human bispecific anti-EGFR/EPHA2 antibody that, as predicted, very effectively suppresses tumor growth, compared to its prototype anti-EGFR therapeutic antibody, cetuximab. Conclusion: Our work not only presents a new bispecific antibody with a high potential for being developed into clinically-relevant biologics, but more importantly, successfully validates a novel unbiased strategy for selecting biologically optimal target combinations. This is of a significant translational relevance, as such multifaceted unbiased approaches are likely to augment the development of effective combination therapies for cancer treatment.
Project description:Heatmap, pathway scores and significant modulation of genes induced by heteronemin, tetrac, and their combination versus the control in HCT 116 cells were performed. (abstract) Overexpression of EGFR accounts for 60-80% of colorectal cancer patients. Anti-EGFR monoclonal antibodies are ineffective in colorectal cancer patients due to KRAS mutation. To discover new therapeutic strategies urgently need for colorectal cancer patients. Sponge extract, heteronemin, has been shown to induce anti-proliferation in different types of cancer. Tetrac shows to inhibit Ras-mutant cancer cell proliferation. Cell viability was evaluated in the HT-29 and HCT-116 cell lines to determine the antitumor effects of heteronemin and its combination with tetrac. Gene expressions were determined by NanoString technology and a quantitative RT-PCR. Protein expressions and cell cycle distributions were respectively assessed by Western blotting and flow cytometry. Heteronemin or its combination with tetrac inhibited cancer cell growth in both mutant and KRAS wild-type CRC. Combined treatment altered the cell cycle in both cell lines at the sub-G1 and S phases. Moreover, their combination induced inactivation of EGFR signaling via downregulating the phosphorylated and total extracellular signal-regulated kinase 1/2 (ERK1/2) protein in both cell lines. The programmed death ligand 1 (PD-L1) protein was reduced in HCT-116 cells, while HT-29 cells showed downregulation of the phosphorylated and total phosphatidylinositol 3-kinase (PI3K) protein. In KRAS mutant cells, heteronemin or its combination with tetrac showed significant modulation of genes associated with cancer progression by NanoString technology. Therefore, tetrac improved the anticancer effect of heteronemin and may be an alternative strategy to effective overcome KRAS mutation-acquired resistance to anti-EGFR therapy. 1. To investigate whether heteronemin combined tetrac induce the antitumor effect in different KRAS statuses of CRC via blocking of EGFR signaling cascades. 2. To assess gene expression profiling in KRAS-mutant CRC cells by nanostring technology.
Project description:Mass spectrometry-based quantitative proteomics profiling of in vivo signaling changes in 41 therapy resistant (osimertinib or EGFR/Met bispecific antibody treament) tumors from four xenograft NSCLC models.
Project description:Despite the implementation of personalized medicine, patients with metastatic CRC (mCRC) still have a dismal overall survival due to the frequent occurrence of acquired resistance mechanisms thereby leading to clinical relapse. Understanding molecular mechanisms that support acquired resistance to anti-EGFR targeted therapy in mCRC is therefore clinically relevant and key to improving patient outcomes. Here, we observe distinct metabolic changes between cetuximab-resistant CRC cell populations, with in particular an increased glycolytic activity in KRAS-mutant cetuximab-resistant LIM1215 but not in KRAS-amplified resistant DiFi cells. We show that cetuximab-resistant LIM1215 cells have the capacity to recycle glycolysis-derived lactate to sustain their growth capacity. This is associated with an upregulation of the lactate importer MCT1 at both transcript and protein levels. Pharmacological inhibition of MCT1, with AR-C155858, reduces the uptake and oxidation of lactate and impairs growth capacity in cetuximab-resistant LIM1215 cells. This study identifies MCT1-dependent lactate utilization as a clinically actionable, metabolic vulnerability to overcome KRAS-mutant-mediated acquired resistance to anti-EGFR therapy in CRC.