Abstract Endogenous and exogenous exposures are associated with distinctive molecular marks in somatic tissues, including human tumours. Integrative multi-omic approaches could help improving the resolution to detect the molecular marks associated with disease aetiology. Here, we leveraged the overlapping molecular information of clear cell renal cell carcinomas (ccRCC) tumours from Mutographs cohort by integrating DNA methylation, transcriptome, and whole-genome sequencing-based somatic mutation data to explore and gain new insights into exposures linked to ccRCC aetiology. Our novel framework identified important sources of biological variance across ccRCC tumours that were summarized as molecular components. We inferred these molecular ccRCC components into independent datasets to further explore their relationship with molecular and epidemiological features of ccRCC, normal adjacent kidney tissues, and other cancer types. Our results revealed a major ccRCC molecular component correlating with cellular mitotic age-related features, particularly the mitotic epigenetic clock (age-adjusted epiTOC2), clock-like DNA mutational signatures (SBS1/ID1), and telomere attrition. This molecular component was overrepresented in ccRCC tumours in comparison with normal paired kidney tissues, associating with PBRM1 and SETD2 somatic cancer driver mutations, genome stability, tumor stage, grade and ccRCC patient survival, independently to chronological age. Pan-cancer analysis supported the mitotic-age effect, represented by this molecular component, in other cancer types. Another ccRCC component was associated with tobacco usage, the presence of tobacco related DNA mutational and methylation signatures, increased total mutation burden, and sex. This component was also related to the epigenetic regulation of xenobiotic metabolism-related genes (e.g., GSTP1), further suggesting a relationship with genotoxic compounds. We further identified molecular components related to the ccRCC tumour microenvironment and cell proliferation, including one component related to BAP1 cancer driver mutations, pro-inflammatory immune cells, and ccRCC patient survival. In conclusion, our study reports a novel framework to molecular characterize ccRCC tumours using an integrative multi-omic approach, providing additional insights into the molecular footprints of endogenous and exogenous exposures in ccRCC tumours, including molecular components with prognostic value for patients. Citation Format: Ricardo Cortez Cardoso Penha, Alexandra Sexton Oates, Sergey Senkin, Han La Park, Nicolas Alcala, Matthieu Foll, Karl Smith-Byrne, Paul Brennan, James Mckay. Multi-omic characterisation of clear cell renal carcinoma reveals endogenous and exogenous processes related to its aetiology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6231.
Detecting genes involved in local adaptation is challenging and of fundamental importance in evolutionary, quantitative, and medical genetics. To this aim, a standard strategy is to perform genome scans in populations of different origins and environments, looking for genomic regions of high differentiation. Because shared population history or population sub-structure may lead to an excess of false positives, analyses are often done on multiple pairs of populations, which leads to i) a global loss of power as compared to a global analysis, and ii) the need for multiple tests corrections. In order to alleviate these problems, we introduce a new hierarchical Bayesian method to detect markers under selection that can deal with complex demographic histories, where sampled populations share part of their history. Simulations show that our approach is both more powerful and less prone to false positive loci than approaches based on separate analyses of pairs of populations or those ignoring existing complex structures. In addition, our method can identify selection occurring at different levels (i.e. population or region-specific adaptation), as well as convergent selection in different regions. We apply our approach to the analysis of a large SNP dataset from low- and high-altitude human populations from America and Asia. The simultaneous analysis of these two geographic areas allows us to identify several new candidate genome regions for altitudinal selection, and we show that convergent evolution among continents has been quite common. In addition to identifying several genes and biological processes involved in high altitude adaptation, we identify two specific biological pathways that could have evolved in both continents to counter toxic effects induced by hypoxia.
Abstract Background Lung neuroendocrine neoplasms (LungNENs) comprise a heterogeneous group of tumors ranging from indolent lesions with good prognosis to highly aggressive cancers. Carcinoids are the rarest LungNENs, display low to intermediate malignancy and may be surgically managed, but show resistance to radiotherapy/chemotherapy in case of metastasis. Molecular profiling is providing new information to understand lung carcinoids, but its clinical value is still limited. Altered alternative splicing is emerging as a novel cancer hallmark unveiling a highly informative layer. Methods We primarily examined the status of the splicing machinery in lung carcinoids, by assessing the expression profile of the core spliceosome components and selected splicing factors in a cohort of 25 carcinoids using a microfluidic array. Results were validated in an external set of 51 samples. Dysregulation of splicing variants was further explored in silico in a separate set of 18 atypical carcinoids. Selected altered factors were tested by immunohistochemistry, their associations with clinical features were assessed and their putative functional roles were evaluated in vitro in two lung carcinoid-derived cell lines. Results The expression profile of the splicing machinery was profoundly dysregulated. Clustering and classification analyses highlighted five splicing factors: NOVA1 , SRSF1 , SRSF10 , SRSF9 and PRPF8 . Anatomopathological analysis showed protein differences in the presence of NOVA1, PRPF8 and SRSF10 in tumor versus non-tumor tissue. Expression levels of each of these factors were differentially related to distinct number and profiles of splicing events, and were associated to both common and disparate functional pathways. Accordingly, modulating the expression of NOVA1, PRPF8 and SRSF10 in vitro predictably influenced cell proliferation and colony formation, supporting their functional relevance and potential as actionable targets. Conclusions These results provide primary evidence for dysregulation of the splicing machinery in lung carcinoids and suggest a plausible functional role and therapeutic targetability of NOVA1, PRPF8 and SRSF10.
Abstract Motivation: Genetic studies focus on increasingly larger genomic regions of both extant and ancient DNA, and there is a need for simulation software to match these technological advances. We present here a new coalescent-based simulation program fastsimcoal, which is able to quickly simulate a variety of genetic markers scattered over very long genomic regions with arbitrary recombination patterns under complex evolutionary scenarios. Availability and Implementation: fastsimcoal is a C++ program compiled for Windows, MacOsX and Linux platforms. It is freely available at cmpg.unibe.ch/software/fastsimcoal/, together with its detailed user manual and example input files. Contact: laurent.excoffier@iee.unibe.ch Supplementary Information: Supplementary data are available at Bioinformatics online.
Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is characterized by hotspot mutations in the KRAS gene (codons 12, 13 or 61) in 85-90% of cases. Codon 12 KRAS mutations have been detected in pancreatic juice, blood and stool samples from pancreatic cancer cases and represent promising biomarkers for early detection. However, the proportion of tumor-derived KRAS mutations in cell-free DNA fragments (cfDNA) has shown large variations, probably because of the heterogeneity in biosamples and assays tested. Deep sequencing technologies (NGS) allow the identification of low-abundance somatic variants, but have not previously been applied to the detection of KRAS hotspot mutations in cfDNA of PDAC cases. Moreover, variant calling methods have rarely been tested against cancer-free individuals so the proportion of false positives is unknown. We investigated whether deep sequencing of KRAS mutations at codons 12, 13 and 61 in plasma samples could represent a robust assay to distinguish pancreatic cancer from chronic pancreatitis and healthy controls. Methods: We developed an Ion Torrent-based NGS KRAS assay (partial exons 2 and 3, totalling 208bp) to screen cfDNA from plasma samples of 461 PDAC cases, 154 individuals with chronic pancreatitis and 421 healthy controls. cfDNA extraction (>4ng) and sequencing (>1000x coverage on average, and absence of systematic high sequencing error rates on the 208bp) performed well on 431 (93%) PDAC cases, 138 (90%) chronic pancreatitis, and 388 (95%) controls. We fit a robust negative-binomial regression to estimate the distribution of the sequencing errors at each DNA bp position and identified outlying samples, which were considered as KRAS positive when q-value<10-3. We also estimated the detection threshold of our assay using serial dilutions of DNA from SW480 KRAS mutated cell-line (p.G12V) in wild-type DNA. Results: Sequencing of the serial dilutions of KRAS p.G12V mutated DNA indicated a detection threshold at a minor allele frequency of 0.2%. KRAS mutations in cfDNA were detected in 83 (19.3%) PDAC cases (73 on codon 12; 8 on codon 61; 1 on codon 13; and 1 multiple codons, i.e., similar in proportions as reported in tumor tissue from the International Cancer Genomic Consortium); 3 (2.2%) chronic pancreatitis (all on codon 12); and 8 (2.1%) healthy controls (4 on codon 12 and 4 on codon 61). Stage was significantly associated with the proportion of detected mutations in cancer cases (chi-squared p = 0.0005): the proportions of cases with detectable KRAS mutations in plasma were 7.9%, 14.9%, and 31.1% for local, regional, and advanced stages, respectively. Conclusions: The NGS-based KRAS mutation screening is a sensitive approach to detect low allelic fraction in plasma cfDNA, although its utility for early detection is still limited. However, it has the capacity to identify specific KRAS mutations, which could be useful in a panel of other non-invasive biomarkers. Citation Format: Florence Le Calvez-Kelm, Matthieu Foll, Magdalena B. Wozniak, Geoffroy Durand, Priscilia Chopard, Maroulio Pertesi, Tiffany Delhomme, Ivana Holcatova, Lenka Foretova, Vladimir Janout, Eleonora Fabianova, Maxime P. Vallée, Paul Brennan, James D. McKay, Graham Byrnes, Ghislaine Scélo. NGS-based detection of KRAS hotspot mutations in plasma cell-free DNA of pancreatic cancer cases. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3137.
During September 2008 through June 2011, we compiled a biological inventory of Meacham Cave in Independence County, AR. Compared to other caves in the region, Meacham Cave houses few vertebrates, but non-aquatic invertebrates were relatively common. A transiently-increased bacterial load in the cave’s only pool of water indicated recent fecal contamination. The combination of vandalism, low vertebrate populations, and high coliform bacterial load reveals that human abuse of the cave has significantly disrupted its ecosystem. Gating the cave in such a way as to allow the movement of bats, salamanders and other animals, while excluding humans, may allow the cave ecosystem to recover. The close proximity of the cave to Lyon College makes it ideal for long-term investigation.
SUMMARY Neuroendocrine neoplasms (NENs) comprise well-differentiated neuroendocrine tumors and poorly-differentiated carcinomas. Treatment options for patients with NENs are limited, in part due to lack of accurate models. To address this need we established the first patient-derived tumor organoids (PDTOs) from pulmonary neuroendocrine tumors and derived PDTOs from an understudied NEN subtype, large cell neuroendocrine carcinoma (LCNEC). PDTOs maintain the gene expression patterns, intra-tumoral heterogeneity, and evolutionary processes of parental tumors. Through drug sensitivity analyses, we uncover therapeutic sensitivities to an inhibitor of NAD salvage biosynthesis and to an inhibitor of BCL-2. Finally, we identify a dependency on EGF in pulmonary neuroendocrine tumor PDTOs. Consistent with these findings, analysis of an independent cohort showed that approximately 50% of pulmonary neuroendocrine tumors expressed EGFR. This study identifies a potentially actionable vulnerability for a subset of NENs, and further highlights the utility of these novel PDTO models for the study of NENs. Graphical abstract Highlights PDTOs of pulmonary NETs and LCNEC were established PDTOs recapitulate intra-tumoral heterogeneity and evolution of parental tumors Drug assays reveal therapeutic vulnerabilities and biomarkers Pulmonary NET PDTOs are dependent on EGF
Abstract Background Organoids are three-dimensional experimental models that summarize the anatomical and functional structure of an organ. Although a promising experimental model for precision medicine, patient-derived tumor organoids (PDTOs) have currently been developed only for a fraction of tumor types. Results We have generated the first multi-omic dataset (whole-genome sequencing, WGS, and RNA-sequencing, RNA-seq) of PDTOs from the rare and understudied pulmonary neuroendocrine tumors ( n = 12; 6 grade 1, 6 grade 2), and provide data from other rare neuroendocrine neoplasms: small intestine (ileal) neuroendocrine tumors ( n = 6; 2 grade 1 and 4 grade 2) and large-cell neuroendocrine carcinoma ( n = 5; 1 pancreatic and 4 pulmonary). This dataset includes a matched sample from the parental sample (primary tumor or metastasis) for a majority of samples (21/23) and longitudinal sampling of the PDTOs (1 to 2 time-points), for a total of n = 47 RNA-seq and n = 33 WGS. We here provide quality control for each technique, and provide the raw and processed data as well as all scripts for genomic analyses to ensure an optimal re-use of the data. In addition, we report somatic small variant calls and describe how they were generated, in particular how we used WGS somatic calls to train a random-forest classifier to detect variants in tumor-only RNA-seq. Conclusions This dataset will be critical to future studies relying on this PDTO biobank, such as drug screens for novel therapies and experiments investigating the mechanisms of carcinogenesis in these understudied diseases.
The MYD88 L265P is a recurrent somatic mutation in neoplastic cells from patients with Waldenström Macroglobulinemia (WM). We identified the MYD88 L265P mutation in three individuals from unrelated families, but its presence did not explain the disease segregation within these WM pedigrees. We observed the mutation in these three individuals at high allele fractions in DNA extracted from EBV-immortalized Lymphoblastoid cell lines established from peripheral blood (LCL), but at much lower allele fractions in DNA extracted directly from peripheral blood, suggesting that this mutation is present in a clonal cell subpopulation rather than of germ-line origin. Furthermore, we observed that the MYD88 L265P mutation is enriched in WM families, detected in 40.5% of patients with familial WM or MGUS (10/22 WM, 5/15 MGUS), compared to 3.5% of patients with familial MM or MGUS (0/72 MM, 4/41 MGUS) (p = 10−7). The mutant allele frequency increased with passages in vitro after immortalization with Epstein-Barr virus (EBV) consistent with the MYD88 L265P described gain-of-function proposed for this mutation. The MYD88 L265P mutation appears to be frequently present in circulating cells in patients with WM, and MGUS, and these cells are amenable to immortalization by EBV.
