is responsible for the direct repair of O6-methylguanine lesions induced by alkylating agents, including temozolomide. promoter hypermethylation is a well-established biomarker for temozolomide response in glioblastoma patients, also correlated with therapeutic response in colorectal cancer. The ARETHUSA clinical trial aims to stratify colorectal cancer patients based on their mismatch repair status.
View Article and Find Full Text PDFBackground: We studied the poorly-known dynamics of circulating DNA (cir-nDNA), as monitored prospectively over an extended post-surgery period, in patients with cancer.
Methods: On patients with stage III colon cancer (N = 120), using personalised molecular tags we carried out the prospective, multicenter, blinded cohort study of the post-surgery serial analysis of cir-nDNA concentration. 74 patients were included and 357 plasma samples tested.
Multiple strategies are continuously being explored to expand the drug target repertoire in solid tumors. We devised a novel computational workflow for transcriptome-wide gene expression outlier analysis that allows the systematic identification of both overexpression and underexpression events in cancer cells. Here, it was applied to expression values obtained through RNA sequencing in 226 colorectal cancer (CRC) cell lines that were also characterized by whole-exome sequencing and microarray-based DNA methylation profiling.
View Article and Find Full Text PDFSerine/threonine-protein kinase B-raf (BRAF) mutations are found in 8-15% of colorectal cancer patients and identify a subset of tumors with poor outcome in the metastatic setting. We have previously reported that BRAF-mutant human cells display a high rate of protein production, causing proteotoxic stress, and are selectively sensitive to the proteasome inhibitors bortezomib and carfilzomib. In this work, we tested whether carfilzomib could restrain the growth of BRAF-mutant colorectal tumors not only by targeting cancer cells directly, but also by promoting an immune-mediated antitumor response.
View Article and Find Full Text PDFBackground: Immunotherapy based on checkpoint inhibitors is highly effective in mismatch repair deficient (MMRd) colorectal cancer (CRC). These tumors carry a high number of mutations, which are predicted to translate into a wide array of neoepitopes; however, a systematic classification of the neoantigen repertoire in MMRd CRC is lacking. Mass spectrometry peptidomics has demonstrated the existence of MHC class I associated peptides (MAPs) originating from non-coding DNA regions.
View Article and Find Full Text PDFThe bacterial genotoxin colibactin promotes colorectal cancer (CRC) tumorigenesis, but systematic assessment of its impact on DNA repair is lacking, and its effect on response to DNA-damaging chemotherapeutics is unknown. We find that CRC cell lines display differential response to colibactin on the basis of homologous recombination (HR) proficiency. Sensitivity to colibactin is induced by inhibition of ATM, which regulates DNA double-strand break repair, and blunted by HR reconstitution.
View Article and Find Full Text PDFIn the evolving molecular treatment landscape of metastatic colorectal cancer (mCRC), the identification of druggable alterations is pivotal to achieve the best therapeutic opportunity for each patient. Because the number of actionable targets is expanding, there is the need to timely detect their presence or emergence to guide the choice of different available treatment options. Liquid biopsy, through the analysis of circulating tumor DNA (ctDNA), has proven safe and effective as a complementary method to address cancer evolution while overcoming the limitations of tissue biopsy.
View Article and Find Full Text PDFThe introduction of targeted therapies represented one of the most significant advances in the treatment of BRAFV600E melanoma. However, the onset of acquired resistance remains a challenge. Previously, we showed in mouse xenografts that vascular endothelial growth factor (VEGFA) removal enhanced the antitumor effect of BRAF inhibition through the recruitment of M1 macrophages.
View Article and Find Full Text PDFBackground: MET-driven acquired resistance is emerging with unanticipated frequency in patients relapsing upon molecular therapy treatments. However, the determination of MET amplification remains challenging using both standard and next-generation sequencing-based methodologies. Liquid biopsy is an effective, non-invasive approach to define cancer genomic profiles, track tumor evolution over time, monitor treatment response and detect molecular resistance in advance.
View Article and Find Full Text PDFBackground: The term "neo- wild-type" refers to the switch to wild-type disease in plasma circulating tumor DNA (ctDNA) from originally mutant colorectal cancers. Consistently, the hypothesis to re-determine mutational status in ctDNA at disease progression in RAS mutant mCRC opened to a new perspective for clinically-based selection of patients to be treated with EGFR inhibitors. Currently, the genomic landscape of "neo- wild-type" is unknown.
View Article and Find Full Text PDFBRAF is a serine/threonine kinase frequently mutated in human cancers. BRAF mutated protein is targeted through the use of kinase inhibitors which are approved for the treatment of melanoma; however, their long-term efficacy is hampered by resistance mechanisms. The PROTAC-induced degradation of BRAF has been proposed as an alternative strategy to avoid the onset of resistance.
View Article and Find Full Text PDFCancer research is a crucial pillar for countries to deliver more affordable, higher quality, and more equitable cancer care. Patients treated in research-active hospitals have better outcomes than patients who are not treated in these settings. However, cancer in Europe is at a crossroads.
View Article and Find Full Text PDFNovel covalent inhibitors of KRASG12C have shown limited response rates in patients with KRASG12C-mutant (MT) colorectal cancer. Thus, novel KRASG12C inhibitor combination strategies that can achieve deep and durable responses are needed. Small-molecule KRASG12C inhibitors AZ'1569 and AZ'8037 were used.
View Article and Find Full Text PDFBackground: Colorectal cancer (CRC) remains largely incurable when diagnosed at the metastatic stage. Despite some advances in precision medicine for this disease in recent years, new molecular targets, as well as prognostic/predictive markers, are highly needed. Neuroligin 1 (NLGN1) is a transmembrane protein that interacts at the synapse with the tumor suppressor adenomatous polyposis Coli (APC), which is heavily involved in the pathogenesis of CRC and is a key player in the WNT/β-catenin pathway.
View Article and Find Full Text PDFCompelling evidence shows that cancer persister cells represent a major limit to the long-term efficacy of targeted therapies. However, the phenotype and population dynamics of cancer persister cells remain unclear. We developed a quantitative framework to study persisters by combining experimental characterization and mathematical modeling.
View Article and Find Full Text PDFUnlabelled: The majority of metastatic colorectal cancers (mCRC) are mismatch repair (MMR) proficient and unresponsive to immunotherapy, whereas MMR-deficient (MMRd) tumors often respond to immune-checkpoint blockade. We previously reported that the treatment of colorectal cancer preclinical models with temozolomide (TMZ) leads to MMR deficiency, increased tumor mutational burden (TMB), and sensitization to immunotherapy. To clinically translate these findings, we designed the ARETHUSA clinical trial whereby O6-methylguanine-DNA-methyltransferase (MGMT)-deficient, MMR-proficient, RAS-mutant mCRC patients received priming therapy with TMZ.
View Article and Find Full Text PDFLiquid biopsies have shown that, in mutant colorectal cancer, the conversion to wild-type * status during the course of the disease is a frequent event, supporting the concept that the evolutionary landscape of colorectal cancer can lead to an unexpected negative selection of RAS mutant clones. The aim of the present study was to clarify whether the negative selection of mutation in plasma might be drug-dependent. For this purpose, we used liquid biopsy to compare the rate of conversion from mutant to wild-type * in two groups of originally mutant mCRC patients: the first treated with chemotherapy alone, while the second was treated with chemotherapy combined with bevacizumab.
View Article and Find Full Text PDFBackground: Malignant pleural mesothelioma (MPM) is a highly aggressive cancer generally diagnosed at an advanced stage and characterized by a poor prognosis. The absence of alterations in druggable kinases, together with an immune-suppressive tumor microenvironment, limits the use of molecular targeted therapies, making the treatment of MPM particularly challenging. Here we investigated the in vitro susceptibility of MPM to lurbinectedin (PM01183), a marine-derived drug that recently received accelerated approval by the FDA for the treatment of patients with metastatic small cell lung cancer with disease progression on or after platinum-based chemotherapy.
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