Project description:Despite relevant clinical and/or familial presentations suggesting a hereditary predisposition (early-onset, multiple primary tumors, familial aggregation), targeted genomic analysis based on the phenotype are often non contributive. As somatic cancer genes are limited, the hypothesis is that the targeted next-generation sequencing of 200 genes, selected for their implications in cancers may contribute to the understanding of many selected patients’ presentation by the identification of germline deleterious mutations, and may identified phenotype overlapping and/or mosaicisms. The focus will be put on early-onset breast, ovarian, colorectal cancer or pediatric cancers and multiple primary tumors.
Project description:Approximately 25% of all head and neck cancers (HNC), and up to 60% of oropharyngeal cancers (OPC) are associated with human papillomavirus (HPV), predominantly HPV16. HPV-associated OPC have better prognosis and a more favorable response to therapy as compared to HPV-negative tumors. Viral oncoproteins are capable of transforming primary human keratinocytes from either genital or oral epithelia in vitro and most likely play the same role in vivo, by disrupting cell-cycle regulatory pathways leading to a genetic progression to ano-genital cancer and OPC. However, the precise mechanisms by which HPV mediates malignant transformation of keratinocytes in the upper digestive tract epithelia are not entirely clear. HPV E7-mediated inactivation of pRb results in overexpression of p16INK4A, which is commonly used as a clinical surrogate marker for HPV positivity/activity. However, high p16INK4A alone has insufficient sensitivity and specificity as a biomarker of HPV positivity in different mucosal sub-sites of HNC. Therefore, increasing emphasis is being placed on the assessment of viral load and E7 oncogene expression, resulting in further classification of HPV positive OPC as HPV-active and HPV-inactive. Differences in risk factors, age of presentation, clinical behavior and gene expression profiles indicate that HPV-positive and HPV-negative tumors develop via different molecular mechanisms and are biologically distinct. According to some reports, the rate of HPV-associated tumors is much lower in AA patients as compared to EA patients in United States. This study aimed to compare the gene expression profiles of HPV-active, -inactive and -negative OPCs from european american patients, and determine their biological differences. ANALYSIS 3: Three-condition, one-color experiment: HPV-active, HPV-inactive and HPV-negative oropharyngeal tumor samples from european american patients. Biological replicates: 8 HPV Negative Tumors. 4 HPV Inactive Tumors. 11 HPV Active Tumors.
Project description:Oropharyngeal cancers have 2 main etiologies : High risk HPV (human papilloma virus) and tobacco/alcohol. The aim of this work is to find a miRNA signature specific to HPV induced oropharyngeal cancers
Project description:The objective of the study is the provide proof of high correlation between somatic and germline mismatch repair instability. This correlation is specifically researched in an area where patients have less access to cancer education and genetic testing for various reasons such as lack of insurance and general accessibility.
The study concentrates on early diagnosis of Lynch syndrome. Lynch syndrome is usually diagnosed from a blood test resulting in a mutation of one of the mismatch repair genes. Those are MLH1, MSH2, MSH 6, PMS2. A mutation in one of these genes creates a mismatch repair instability,hence higher incidence of cancers in specific organ groups. Amongst these organs are the Uterus, Ovaries, Upper genitourinary system, Pancreas and GI system.
The most common endometrial carcinoma which is found in Lynch syndrome is of endometrioid histology. Most patients with known germline mismatch repair instability, have the same somatic mutation. Our study is looking into correlating somatic mutation to germline mutation.
By doing so, patients diagnosed with somatic mismatch repair instability will be also diagnosed with lynch syndrome without germline genetic testing.
Screening programs will be utilized earlier and preventive procedures offered.
Due to less access to educational programs, genetic counseling and testing in underserved areas, patients are sometimes lost to follow up. Our study seeks to prove high correlation between somatic and germline mutations and by doing so, patient will be diagnosed with Lynch syndrome straight after endometrial cancer staging. As a result, increased compliance will be expected and patients will be offered the recommended preventative surgeries and screening protocols.
Project description:The choice between somatic and germline fates is essential for species survival. This choice occurs in embryonic epiblast cells, as these cells are competent for both somatic and germline differentiation. Transcription factors (TFs) play a central role in this process by binding to specific chromatin loci to modulate gene expression and determine cell identity. The TF OTX2 regulates the choice between somatic and germline fates, as Otx2-null epiblast-like cells (EpiLCs) form primordial germ cell-like cells (PGCLCs) with enhanced efficiency. However, the mechanisms by which OTX2 achieves this function are not fully characterized. Here we show that OTX2 controls chromatin accessibility to enable somatic differentiation. By performing CUT&RUN for OTX2 and ATAC-seq in wild-type and Otx2-null embryonic stem cells and EpiLCs, we identified regions where OTX2 binding opens chromatin. Enforced OTX2 expression maintains accessibility at these regions and induces opening of 4,000 additional somatic-associated regions in the presence of PGC-inducing cytokines. Once cells have acquired germline identity, the 4,000 additional somatic associated regions do not respond to OTX2 and remain closed. Our results indicate that OTX2 works in cells with dual competence for both somatic and germline differentiation to increase accessibility of somatic regulatory regions and induce the somatic fate at the expense of the germline.
Project description:The choice between somatic and germline fates is essential for species survival. This choice occurs in embryonic epiblast cells, as these cells are competent for both somatic and germline differentiation. Transcription factors (TFs) play a central role in this process by binding to specific chromatin loci to modulate gene expression and determine cell identity. The TF OTX2 regulates the choice between somatic and germline fates, as Otx2-null epiblast-like cells (EpiLCs) form primordial germ cell-like cells (PGCLCs) with enhanced efficiency. However, the mechanisms by which OTX2 achieves this function are not fully characterized. Here we show that OTX2 controls chromatin accessibility to enable somatic differentiation. By performing CUT&RUN for OTX2 and ATAC-seq in wild-type and Otx2-null embryonic stem cells and EpiLCs, we identified regions where OTX2 binding opens chromatin. Enforced OTX2 expression maintains accessibility at these regions and induces opening of 4,000 additional somatic-associated regions in the presence of PGC-inducing cytokines. Once cells have acquired germline identity, the 4,000 additional somatic associated regions do not respond to OTX2 and remain closed. Our results indicate that OTX2 works in cells with dual competence for both somatic and germline differentiation to increase accessibility of somatic regulatory regions and induce the somatic fate at the expense of the germline.
Project description:Approximately 25% of all head and neck cancers (HNC), and up to 60% of oropharyngeal cancers (OPC) are associated with human papillomavirus (HPV), predominantly HPV16. HPV-associated OPC have better prognosis and a more favorable response to therapy as compared to HPV-negative tumors. Viral oncoproteins are capable of transforming primary human keratinocytes from either genital or oral epithelia in vitro and most likely play the same role in vivo, by disrupting cell-cycle regulatory pathways leading to a genetic progression to ano-genital cancer and OPC. However, the precise mechanisms by which HPV mediates malignant transformation of keratinocytes in the upper digestive tract epithelia are not entirely clear. HPV E7-mediated inactivation of pRb results in overexpression of p16INK4A, which is commonly used as a clinical surrogate marker for HPV positivity/activity. However, high p16INK4A alone has insufficient sensitivity and specificity as a biomarker of HPV positivity in different mucosal sub-sites of HNC. Therefore, increasing emphasis is being placed on the assessment of viral load and E7 oncogene expression, resulting in further classification of HPV positive OPC as HPV-active and HPV-inactive. Differences in risk factors, age of presentation, clinical behavior and gene expression profiles indicate that HPV-positive and HPV-negative tumors develop via different molecular mechanisms and are biologically distinct. According to some reports, the rate of HPV-associated tumors is much lower in AA patients as compared to EA patients in United States. This study aimed to compare the gene expression profiles of HPV-active, -inactive and -negative OPCs from european american patients, and determine their biological differences.