28 research outputs found
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Integrated Genomic, Epigenomic, and Expression Analyses of Ovarian Cancer Cell Lines.
To improve our understanding of ovarian cancer, we performed genome-wide analyses of 45 ovarian cancer cell lines. Given the challenges of genomic analyses of tumors without matched normal samples, we developed approaches for detection of somatic sequence and structural changes and integrated these with epigenetic and expression alterations. Alterations not previously implicated in ovarian cancer included amplification or overexpression of ASXL1 and H3F3B, deletion or underexpression of CDC73 and TGF-beta receptor pathway members, and rearrangements of YAP1-MAML2 and IKZF2-ERBB4. Dose-response analyses to targeted therapies revealed unique molecular dependencies, including increased sensitivity of tumors with PIK3CA and PPP2R1A alterations to PI3K inhibitor GNE-493, MYC amplifications to PARP inhibitor BMN673, and SMAD3/4 alterations to MEK inhibitor MEK162. Genome-wide rearrangements provided an improved measure of sensitivity to PARP inhibition. This study provides a comprehensive and broadly accessible resource of molecular information for the development of therapeutic avenues in ovarian cancer
Metastatic Colorectal Cancer Treatment Response Evaluation by Ultra-Deep Sequencing of Cell-Free DNA and Matched White Blood Cells
Purpose: Circulating tumor DNA (ctDNA) has the potential to guide therapy selection and monitor treatment response in patients with metastatic cancer. However, germline and clonal hematopoiesis- associated alterations can confound identification of tumorspecific mutations in cell-free DNA (cfDNA), often requiring additional sequencing of tumor tissue. The current study assessed whether ctDNA-based treatment response monitoring could be performed in a tumor tissue-independent manner by combining ultra-deep targeted sequencing analyses of cfDNA with patientmatched white blood cell (WBC)-derived DNA. Experimental Design: In total, 183 cfDNA and 49WBCsamples, along with 28 tissue samples, from 52 patients with metastatic colorectal cancer participating in the prospective phase III CAIRO5 clinical trial were analyzed using an ultra-deep targeted sequencing liquid biopsy assay. Results: The combined cfDNA and WBC analysis prevented false-positives due to germline or hematopoietic variants in 40% of patients. Patient-matched tumor tissue sequencing did not provide additional information. Longitudinal analyses of ctDNA were more predictive of overall survival than standard-of-care radiological response evaluation. ctDNA mutations related to primary or acquired resistance to panitumumab were identified in 42% of patients. Conclusions: Accurate calling of ctDNA mutations for treatment response monitoring is feasible in a tumor tissue-independent manner by combined cfDNA and patient-matched WBC genomic DNA analysis. This tissue biopsy-independent approach simplifies sample logistics and facilitates the application of liquid biopsy ctDNA testing for evaluation of emerging therapy resistance, opening new avenues for early adaptation of treatment regimens
Genomic characterization of malignant progression in neoplastic pancreatic cysts
Intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs) are non-invasive neoplasms that are often observed in association with invasive pancreatic cancers, but their origins and evolutionary relationships are poorly understood. In this study, we analyze 148 samples from IPMNs, MCNs, and small associated invasive carcinomas from 18 patients using whole exome or targeted sequencing. Using evolutionary analyses, we establish that both IPMNs and MCNs are direct precursors to pancreatic cancer. Mutations in SMAD4 and TGFBR2 are frequently restricted to invasive carcinoma, while RNF43 alterations are largely in non-invasive lesions. Genomic analyses suggest an average window of over three years between the development of high-grade dysplasia and pancreatic cancer. Taken together, these data establish non-invasive IPMNs and MCNs as origins of invasive pancreatic cancer, identifying potential drivers of invasion, highlighting the complex clonal dynamics prior to malignant transformation, and providing opportunities for early detection and intervention
SHMT1 1420 and MTHFR 677 variants are associated with rectal but not colon cancer
<p>Abstract</p> <p>Background</p> <p>Association between rectal or colon cancer risk and serine hydroxymethyltransferase 1 (<it>SHMT1</it>) C1420T or methylenetetrahydrofolate reductase (<it>MTHFR</it>) C677T polymorphisms was assessed. The serum total homocysteine (HCY), marker of folate metabolism was also investigated.</p> <p>Methods</p> <p>The <it>SHMT1 </it>and <it>MTHFR </it>genotypes were determined by real-time PCR and PCR-RFLP, respectively in 476 patients with rectal, 479 patients with colon cancer and in 461 and 478, respective controls matched for age and sex. Homocysteine levels were determined by HPLC kit. The association between polymorphisms and cancer risk was evaluated by logistic regression analysis adjusted for age, sex and body mass index. The population stratification bias was also estimated.</p> <p>Results</p> <p>There was no association of genotypes or diplotypes with colon cancer. The rectal cancer risk was significantly lower for <it>SHMT1 </it>TT (OR = 0.57, 95% confidence interval (CI) 0.36-0.89) and higher for <it>MTHFR </it>CT genotypes (OR = 1.4, 95%CI 1.06-1.84). A gene-dosage effect was observed for <it>SHMT1 </it>with progressively decreasing risk with increasing number of T allele (p = 0.014). The stratified analysis according to age and sex revealed that the association is mainly present in the younger (< 60 years) or male subgroup. As expected from genotype analysis, the <it>SHMT1 </it>T allele/<it>MTHFR </it>CC diplotype was associated with reduced rectal cancer risk (OR 0.56, 95%CI 0.42-0.77 vs all other diplotypes together). The above results are unlikely to suffer from population stratification bias. In controls HCY was influenced by <it>SHMT1 </it>polymorphism, while in patients it was affected only by Dukes' stage. In patients with Dukes' stage C or D HCY can be considered as a tumor marker only in case of <it>SHMT1 </it>1420CC genotypes.</p> <p>Conclusions</p> <p>A protective effect of <it>SHMT1 </it>1420T allele or <it>SHMT1 </it>1420 T allele/<it>MTHFR </it>677 CC diplotype against rectal but not colon cancer risk was demonstrated. The presence of <it>SHMT1 </it>1420 T allele significantly increases the HCY levels in controls but not in patients. Homocysteine could be considered as a tumor marker in <it>SHMT1 </it>1420 wild-type (CC) CRC patients in Dukes' stage C and D. Further studies need to clarify why <it>SHMT1 </it>and <it>MTHFR </it>polymorphisms are associated only with rectal and not colon cancer risk.</p
The frequency of dihydropyrimidine dehydro-genase (dpd) deficiency in a hungarian colo-rectal cancer (crc) population; lack of corre-lation between very low dpd values and the dpd ivs14+1g -> a mutation
Their fast formation and microscopic scale of heavy flavor (HF) probes are ideal for a Quark-Gluon Plasma (QGP) tomography. Besides, the large fraction of energy carried by the measured heavy flavor hadron from the hard process fragmentation also favors a precise study of the partonic density and initial state effects in nucleus. LHC experiments are exploring heavy flavor probes in different manners such as the study of partonic energy loss in cold and QGP medium, diffusion properties, hadron coalescence and local free energy quantification using bound state quarkonia. This manuscript summarizes the most recent experimental developments in the field coming from all LHC experiments using data taken in Pb and PbPb collisions in collision energies ranging from 86.6 GeV to 8.16 TeV