Project description:Genome-wide analysis of cell-free DNA (cfDNA) methylation profile has been recognized as a promising approach for sensitive and specific detection of many cancers. However, scaling such genome-wide assays for clinical translation is impractical due to the high cost of whole genome bisulfite sequencing. We have shown that the small fraction of GC-rich genome is highly enriched in CpG sites and disproportionately harbors the majority of cancer-specific methylation signature. Here, we report on the simple but effective Heat enrichment of CpG-rich regions for Bisulfite Sequencing (Heatrich-BS) platform that allows for focused methylation profiling in these highly informative regions. Our novel method and bioinformatics algorithm enable accurate tumor burden estimation with high sensitivity and quantitative tracking of colorectal cancer patient’s response to treatment, at much reduced sequencing cost suitable for frequent monitoring. We also show, for the first time, tumor epigenetic subtyping from cfDNA using Heatrich-BS, which could enable patient stratification from non-invasive liquid biopsy. As such, Heatrich-BS holds great potential for highly scalable screening and regular monitoring of cancer using liquid biopsy.
Project description:Genome-wide analysis of cell-free DNA (cfDNA) methylation profile has been recognized as a promising approach for sensitive and specific detection of many cancers. However, scaling such genome-wide assays for clinical translation is impractical due to the high cost of whole genome bisulfite sequencing. We have shown that the small fraction of GC-rich genome is highly enriched in CpG sites and disproportionately harbors the majority of cancer-specific methylation signature. Here, we report on the simple but effective Heat enrichment of CpG-rich regions for Bisulfite Sequencing (Heatrich-BS) platform that allows for focused methylation profiling in these highly informative regions. Our novel method and bioinformatics algorithm enable accurate tumor burden estimation with high sensitivity and quantitative tracking of colorectal cancer patient’s response to treatment, at much reduced sequencing cost suitable for frequent monitoring. We also show, for the first time, tumor epigenetic subtyping from cfDNA using Heatrich-BS, which could enable patient stratification from non-invasive liquid biopsy. As such, Heatrich-BS holds great potential for highly scalable screening and regular monitoring of cancer using liquid biopsy.
Project description:The potential of eccrine sweat as a bio-fluid of interest for diagnosis and personalized therapy has not yet been fully evaluated, due to the lack of in-depth sweat characterization studies. Thanks to recent developments in the field of omics together with the availability of accredited eccrine sweat collection methods, the analysis of human sweat may now be envisioned as a standardized, non-invasive test for individualized monitoring and personalized medicine. Here, we characterized individual sweat samples, collected from 28 healthy adult volunteers under the most standardized sampling methodology, by applying an optimized Shotgun proteomic analysis. This deep characterization of the sweat proteome allowed the identification of about 1000 unique proteins from which 347 were identified across all samples. Annotation-wise, the study of the sweat proteome unveiled the over-representation of newly addressed Actin dynamics, oxidative stress and proteasome-related functions, in addition to well-described proteolysis and anti-microbial immunity. The sweat proteome composition appeared to be correlated to the inter-individual variability of sweat secretion parameters (water and solute losses). Besides, both gender-exclusive proteins and gender-specific protein abundances were highlighted in spite of the high similarity between human female and male sweat proteomes. In conclusion, standardized sample collection coupled to optimized shotgun proteomics significantly improved the depth of sweat proteome coverage, far beyond previous similar studies. The identified proteins were involved in many diverse biological processes and molecular functions indicating the potential of this bio-fluid as a valuable biological matrix for further studies. Addressing sweat variability, our results prove the proteomic profiling of sweat to be a promising bio-fluid for individualized, non-invasive monitoring and personalized medicine.
Project description:Targeted therapy drug monitoring in digestive oncology: Dosage of plasma levels of various multikinase inhibitors (MKI) in patients treated for advanced digestive cancer (gastrointestinal stromal tumor (GIST), metastatic colorectal cancer (mCRC), hepatocellular carcinoma (HCC), gastroenteropancreatic neuroendocrine tumor (gepNET), or pancreatic neuroendocrine tumor (pNET)), with the aim of determine the optimal dose adapted for each patient, in the future.
Project description:Resistant tumours are thought to arise from the action of Darwinian selection on intratumoral genetic heterogeneity. However, clonal selection is incompatible with the late recurrence often characterising luminal breast cancers treated with endocrine therapy (ET), suggesting a more complex interplay between genetic and non-genetic factors. In the present study, we dissect the contributions of clonal genetic diversity and transcriptional plasticity during the early and late phases of ET at single-cell resolution. Using single-cell RNA-sequencing and imaging we disentangle the transcriptional variability of plastic cells and define a rare sub-population of pre-adapted (PA) cells which undergoes further transcriptomic reprogramming and copy number changes to acquire full resistance. PA cells show reduced oestrogen receptor α activity but increased features of quiescence and migration. We find evidence for sub-clonal expression of this PA signature in primary tumours and for dominant expression in clustered circulating tumour cells. We propose a multi-step model for ET resistance development and advocate the use of stage-specific biomarkers.
2019-07-17 | GSE122743 | GEO
Project description:Tumour mutation burden of FFPE tumour
Project description:PurposectDNA offers a promising, noninvasive approach to monitor therapeutic efficacy in real-time. We explored whether the quantitative percent change in ctDNA early after therapy initiation can predict treatment response and progression-free survival (PFS) in patients with metastatic gastrointestinal cancer.Experimental designA total of 138 patients with metastatic gastrointestinal cancers and tumor profiling by next-generation sequencing had serial blood draws pretreatment and at scheduled intervals during therapy. ctDNA was assessed using individualized droplet digital PCR measuring the mutant allele fraction in plasma of mutations identified in tumor biopsies. ctDNA changes were correlated with tumor markers and radiographic response.ResultsA total of 138 patients enrolled. A total of 101 patients were evaluable for ctDNA and 68 for tumor markers at 4 weeks. Percent change of ctDNA by 4 weeks predicted partial response (PR, P < 0.0001) and clinical benefit [CB: PR and stable disease (SD), P < 0.0001]. ctDNA decreased by 98% (median) and >30% for all PR patients. ctDNA change at 8 weeks, but not 2 weeks, also predicted CB (P < 0.0001). Four-week change in tumor markers also predicted response (P = 0.0026) and CB (P = 0.022). However, at a clinically relevant specificity threshold of 90%, 4-week ctDNA change more effectively predicted CB versus tumor markers, with a sensitivity of 60% versus 24%, respectively (P = 0.0109). Patients whose 4-week ctDNA decreased beyond this threshold (≥30% decrease) had a median PFS of 175 days versus 59.5 days (HR, 3.29; 95% CI, 1.55-7.00; P < 0.0001).ConclusionsSerial ctDNA monitoring may provide early indication of response to systemic therapy in patients with metastatic gastrointestinal cancer prior to radiographic assessments and may outperform standard tumor markers, warranting further evaluation.
Project description:Background: Development of target specific therapeutics greatly benefits from simultaneous identification of biomarkers to determine aspects of bioactivity, drug safety and efficacy or even treatment outcome. This is particularly important when targeting pleiotropic factors such as the TGFbeta system. TGFbeta has become a prime target for cancer therapeutics since inhibition of TGFbeta signaling simultaneously attacks the tumor and its microenvironment. Methods: Here we introduce blood transcriptomics followed by a defined set of validation assays as a promising approach to identify novel biomarkers for monitoring TGFbeta therapy. Findings: Our initial genome-wide analysis of transcription in peripheral blood revealed 12 candidate genes specifically regulated in peripheral blood by the TGFbeta receptor I kinase inhibitor LY2109761. In subsequent in vitro and in vivo molecular and immunological analyses, the combined monitoring of gene regulation of three genes, namely TMEPAI, OCIAD2, and SMAD7 was established as novel biomarkers for anti-TGFbeta based therapies. Interpretation: Overall, the proposed algorithm of biomarker identification is easily adapted towards other drug candidates for which gene regulation can be established in peripheral blood. CD4+ T cells were serum-deprived for 12 hours followed by 8 hours incubation with the indicated compounds, total of 22 samples.
Project description:Whole genome sequencing (WGS) of circulating tumour DNA (ctDNA) is now a clinically important biomarker for predicting therapy response, disease burden and disease progression. However, the translation of ctDNA monitoring into vital pre-clinical PDX models has not been possible owing to low circulating blood volumes in small rodents. Here, we describe the longitudinal detection and monitoring of ctDNA from minute volumes of blood in PDX mice. We developed a xenograft Tumour Fraction (xTF) metric using shallow WGS of dried blood spots (DBS), and demonstrate its application to quantify disease burden, monitor treatment response and predict disease outcome in a pre-clinical study of PDX mice. Further, we show how our DBS-based ctDNA assay can be used to detect gene-specific copy number changes and examine the copy number landscape over time. Use of sequential DBS ctDNA assays could transform future trial designs in both mice and patients.
Project description:Large-scale genomic profiling efforts have facilitated the characterization of molecular alterations in cancers and aided the development of targeted kinase inhibitors for a wide array of cancer types. However, resistance to these targeted therapies invariably develops and limits their clinical efficacy. Targeting tumours with kinase inhibitors induces complex adaptive survival programs that promote the persistence of a fraction of the original cancer cell population, facilitating the eventual outgrowth of inhibitor-resistant tumour clones following clonal evolution. Here we show that the addition of a newly identified transcriptional repressor, THZ1, to targeted cancer therapy enhances cell killing and impedes the emergence of drug-resistant cell populations in cellular and in vivo cancer models with diverse genetic dependencies. We propose that targeted therapy induces a state of transcriptional dependency in a subpopulation of cells poised to become drug tolerant. THZ1 can exploit this dependency by blocking dynamic transcriptional responses, remodelling of enhancers and key signalling outputs required for tumour cell survival in the setting of targeted cancer therapies. These findings suggest that the addition of THZ1 to targeted cancer therapies is a promising broad-based strategy to hinder the emergence of drug-resistant cancer cell populations.