Project description:<p>Mosaic chromosomal aneuploidy occurs when only a subset of cells carries an abnormal number of chromosomes. Mosaic aneuploidy has been reported in multiple types of diseases. Here we have developed a new sequencing-based approach to identify, characterize and quantify mosaic aneuploidy events in human tissue samples. This ongoing study has begun with results from sequencing data from two clinical patients, one with autism spectrum disorder (ASD) and the other with hemihyperplasia (<a href="https://www.omim.org/entry/235000" target="_blank">OMIM 235000</a>). We captured ~100,000 common SNPs from the samples to identify the nature of the mosaic aneuploidy events in each of the samples.</p>
Project description:Aneuploidy, while detrimental to untransformed cells, is notably prevalent in cancer. Aneuploidy is found as an early event during tumorigenesis which indicates that cancer cells have the ability to surmount the initial stress responses associated with aneuploidy, enabling rapid proliferation despite aberrant karyotypes. To generate more insight into key cellular processes and requirements underlying adaptation to aneuploidy, we generated a panel of aneuploid clones in p53-deficient RPE-1 cells and studied their behavior over time. As expected, de novo generated aneuploid clones initially displayed reduced fitness, enhanced levels of chromosomal instability and an upregulated inflammatory response. Intriguingly, after a prolonged period of culturing, aneuploid clones exhibited increased proliferation rates while maintaining aberrant karyotypes, indicative of an adaptive response to the aneuploid state. Interestingly, all adapted clones displayed reduced chromosomal instability (CIN) and reduced inflammatory signaling, suggesting that these are common aspects of adaptation to aneuploidy. Collectively, our data suggests that CIN and concomitant inflammation are key processes that require correction to allow for fast proliferation in vitro. Finally, we provide evidence that amplification of oncogenic KRAS can promote adaptation.
Project description:Aneuploidy is a frequent feature of human tumors. Germline mutations leading to aneuploidy are very rare in humans, and their tumor-promoting properties are mostly unknown at the molecular level. We report here novel germline biallelic mutations in MAD1L1, the gene encoding the Spindle Assembly Checkpoint (SAC) protein MAD1, in a 36-year-old female with a dozen of neoplasias, including five malignant tumors. Functional studies in peripheral blood cells demonstrated lack of full-length protein and deficient SAC response, resulting in ~30-40% of aneuploid cells as detected by cytogenetic and single-cell (sc) DNA analysis. scRNA-seq analysis of proband blood cells identified mitochondrial stress accompanied by systemic inflammation with enhanced interferon and NFkB signaling. The inference of chromosomal aberrations from scRNA-seq analysis detected inflammatory signals both in aneuploid and euploid cells, suggesting a non-cell autonomous response to aneuploidy. In addition to random aneuploidies, MAD1L1 mutations resulted in specific clonal expansions of T-cells with chromosome 18 gains and enhanced cytotoxic profile, as well as intermediate B-cells with chromosome 12 gains and transcriptomic signatures characteristic of chronic lymphocytic leukemia cells. These data point to MAD1L1 mutations as the cause of a new variant of mosaic variegated aneuploidy syndrome (MVA) with systemic inflammation and unprecedented tumor susceptibility.
Project description:Aneuploidy is the leading cause of miscarriage and congenital birth defects, and a hallmark of cancer. Despite this strong association with human disease, the genetic causes of aneuploidy remain largely unknown. Through exome sequencing of patients with constitutional mosaic aneuploidy, we identified biallelic truncating mutations in CENATAC (CCDC84). We show that CENATAC is a novel component of the minor (U12-dependent) spliceosome that promotes splicing of a specific, rare minor intron subtype. This subtype is characterized by AT-AN splice sites and relatively high basal levels of intron retention. CENATAC depletion or expression of disease mutants resulted in excessive retention of AT-AN minor introns in ~100 genes enriched for nucleocytoplasmic transport and cell cycle regulators, and caused chromosome segregation errors. Our findings reveal selectivity in minor intron splicing and suggest a link between minor spliceosome defects and constitutional aneuploidy in humans.
Project description:The mucosae of the oral cavity are different at the histological level but are all exposed to common genotoxic agents. As a result of this exposure, changes in the mucosal epithelia develop giving rise to Oral Potentially Malignant Lesions (OPMLs), which with time may in turn progress to Oral Squamous Cell Carcinomas (OSCCs). Therefore, much effort should be devoted to identify features able to predict the likeliness of progression associated with an OPML. Such features may be helpful in assisting the clinician to establish both appropriate therapies and follow-up schedules. Here, we report a pilot study that compared the anatomical subsites of OPMLs development with occurrence of DNA aneuploidy and chromosomal copy number aberrations (CNAs). Multiple samples from histologically diagnosed OPMLs were processed for high resolution DNA flow cytometry (hr DNA-FCM) in order to determine the relative DNA content expressed by the DNA index (DI). Additionally, array-Comparative Genomic Hybridization (a-CGH) analysis was performed on FCM-sorted nuclei subpopulations based on DI values. Tongue OPMLs were more frequently associated with DNA aneuploidy and CNAs than OPMLs arising from all the other mucosal subsites. We suggest that the follow-up and the management of the patients with tongue OPMLs should receive a distinctive special attention. Clearly, this conclusion should be validated in a prospective clinical study. exposed to common genotoxic agents. As a result of this exposure, changes in the mucosal epithelia develop giving rise to Oral Potentially Malignant Lesions (OPMLs), which with time may in turn progress to Oral Squamous Cell Carcinomas (OSCCs). Therefore, much effort should be devoted to identify features able to predict the likeliness of progression associated with an OPML. Such features may be helpful in assisting the clinician to establish both appropriate therapies and follow-up schedules. Here, we report a pilot study that compared the anatomical subsites of OPMLs development with occurrence of DNA aneuploidy and chromosomal copy number aberrations (CNAs). Multiple samples from histologically diagnosed OPMLs were processed for high resolution DNA flow cytometry (hr DNA-FCM) in order to determine the relative DNA content expressed by the DNA index (DI). Additionally, array-Comparative Genomic Hybridization (a-CGH) analysis was performed on FCM-sorted nuclei subpopulations based on DI values. Tongue OPMLs were more frequently associated with DNA aneuploidy and CNAs than OPMLs arising from all the other mucosal subsites. We suggest that the follow-up and the management of the patients with tongue OPMLs should receive a distinctive special attention. Clearly, this conclusion should be validated in a prospective clinical study.
Project description:Oral potentially malignant disorders (OPMDs) may precede oral squamous cell carcinoma (OSCC). Early detection of OPMDs has a crucial role in OSCC prevention. DNA aneuploidy and chromosomal aberrations are markers of genomic DNA damage and chromosomal instability (CIN), which is involved in cancer development. We explored the relationship among genomic DNA copy number aberrations (CNAs), histological diagnosis and DNA aneuploidy in OPMDs/OSCCs. Samples from OPMDs and OSCCs were processed for high resolution DNA flow cytometry (hr DNA-FCM) to determine the relative DNA content expressed with the DNA index (DI). Additionally, on a subset of these samples, array-Comparative Genomic Hybridization (aCGH) analysis was performed on DNA obtained from diploid nuclei suspension or from aneuploid-enriched nuclei suspensions.
Project description:Oral potentially malignant disorders (OPMDs) may precede oral squamous cell carcinoma (OSCC). Early detection of OPMDs has a crucial role in OSCC prevention. DNA aneuploidy and chromosomal aberrations are markers of genomic DNA damage and chromosomal instability (CIN), which is involved in cancer development. We explored the relationship among genomic DNA copy number aberrations (CNAs), histological diagnosis and DNA aneuploidy in OPMDs/OSCCs. Samples from OPMDs and OSCCs were processed for high resolution DNA flow cytometry (hr DNA-FCM) to determine the relative DNA content expressed with the DNA index (DI). Additionally, on a subset of these samples, array-Comparative Genomic Hybridization (aCGH) analysis was performed on DNA obtained from diploid nuclei suspension or from aneuploid-enriched nuclei suspensions. DNA copy number aberrations were determined using high resolution arrays on 151 samples (2x105K, n=82 samples, and 4x180K, n=69 samples) (Agilent Technologies, Palo Alto, CA, USA). Labeling, hybridization, scanning and feature extraction were performed as previously described using the cross hybridization method previously described [Castagnola P, Malacarne D, Scaruffi P, Maffei M, Donadini A, et al. (2011) Chromosomal aberrations and aneuploidy in oral potentially malignant lesions: distinctive features for tongue. BMC Cancer 11: 445.].
Project description:The mucosae of the oral cavity are different at the histological level but are all exposed to common genotoxic agents. As a result of this exposure, changes in the mucosal epithelia develop giving rise to Oral Potentially Malignant Lesions (OPMLs), which with time may in turn progress to Oral Squamous Cell Carcinomas (OSCCs). Therefore, much effort should be devoted to identify features able to predict the likeliness of progression associated with an OPML. Such features may be helpful in assisting the clinician to establish both appropriate therapies and follow-up schedules. Here, we report a pilot study that compared the anatomical subsites of OPMLs development with occurrence of DNA aneuploidy and chromosomal copy number aberrations (CNAs). Multiple samples from histologically diagnosed OPMLs were processed for high resolution DNA flow cytometry (hr DNA-FCM) in order to determine the relative DNA content expressed by the DNA index (DI). Additionally, array-Comparative Genomic Hybridization (a-CGH) analysis was performed on FCM-sorted nuclei subpopulations based on DI values. Tongue OPMLs were more frequently associated with DNA aneuploidy and CNAs than OPMLs arising from all the other mucosal subsites. We suggest that the follow-up and the management of the patients with tongue OPMLs should receive a distinctive special attention. Clearly, this conclusion should be validated in a prospective clinical study. exposed to common genotoxic agents. As a result of this exposure, changes in the mucosal epithelia develop giving rise to Oral Potentially Malignant Lesions (OPMLs), which with time may in turn progress to Oral Squamous Cell Carcinomas (OSCCs). Therefore, much effort should be devoted to identify features able to predict the likeliness of progression associated with an OPML. Such features may be helpful in assisting the clinician to establish both appropriate therapies and follow-up schedules. Here, we report a pilot study that compared the anatomical subsites of OPMLs development with occurrence of DNA aneuploidy and chromosomal copy number aberrations (CNAs). Multiple samples from histologically diagnosed OPMLs were processed for high resolution DNA flow cytometry (hr DNA-FCM) in order to determine the relative DNA content expressed by the DNA index (DI). Additionally, array-Comparative Genomic Hybridization (a-CGH) analysis was performed on FCM-sorted nuclei subpopulations based on DI values. Tongue OPMLs were more frequently associated with DNA aneuploidy and CNAs than OPMLs arising from all the other mucosal subsites. We suggest that the follow-up and the management of the patients with tongue OPMLs should receive a distinctive special attention. Clearly, this conclusion should be validated in a prospective clinical study. We analyzed: 19 samples (4 aneuploid and 15 diploid components) deriving from oral potentially malignant lesions without dysplasia obtained of 16 patients; 14 samples (2 aneuploid and 12 diploid components) deriving from oral potentially malignant lesions with dysplasia obtained from 11 patients (two patients had multiple dysplastic lesions); 2 samples from visually normal mucosa in the near field obtained from two patients with dysplastic lesions. All the aneuploid samples had a purity of at least 90%.