Genes, Chromosomes & Cancer最新文献

Burkitt lymphoma (BL) is an aggressive germinal center B-cell-derived malignancy. Historically, sporadic, endemic, and immunodeficiency-associated variants were distinguished, which differ in the frequency of Epstein–Barr virus (EBV) positivity. Aiming to identify subgroups based on DNA methylation patterns, we here profiled 96 BL cases, 17 BL cell lines, and six EBV-transformed lymphoblastoid cell lines using Illumina BeadChip arrays. DNA methylation analyses clustered the cases into four subgroups: two containing mostly EBV-positive cases (BL-mC1, BL-mC2) and two containing mostly EBV-negative cases (BL-mC3, BL-mC4). The subgroups BL-mC1/2, enriched for EBV-positive cases, showed increased DNA methylation, epigenetic age, and, in part, proliferation history compared to BL-mC3/4. CpGs hypermethylated in EBV-positive BLs were enriched for polycomb repressive complex 2 marks, while the CpGs hypomethylated in EBV-negative BLs were linked to, for example, B-cell receptor signaling. EBV-associated hypermethylation affected regulatory regions of genes frequently mutated in BL (e.g., CCND3, TP53) and impacted superenhancers. This finding suggests that hypermethylation may compensate for the lower mutational burden of pathogenic drivers in EBV-positive BLs. Though minor, significant differences were also observed between EBV-positive endemic and sporadic cases (e.g., at the SOX11 and RUNX1 loci). Our findings suggest that EBV status, rather than epidemiological variants, drives the DNA methylation-based subgrouping of BL.

EGFR-kinase-domain duplication (KDD) has been reported in Infantile fibrosarcoma-like myofibroblastic tumors and cellular mesoblastic nephroma. We report a pulmonary neoplasm with EGFR-(KDD) and infantile fibrosarcoma-like histologic features in a female infant with an unusual clinical and histologic evolution, characterized by persistent disease with morphologic features of Congenital Peribronchial Myofibroblastic Tumor (CPMT) after chemotherapy and targeted therapy. The CPMT morphology with EGFR-KDD in the post-therapy specimen might be an evolution induced by the treatment, which suggests the hypothesis that CPMT is part of the morphologic spectrum of infantile fibrosarcoma/cellular mesoblastic nephroma.

The non-coding genome, constituting 98% of human DNA, remains largely unexplored, yet holds potential for identifying new biomarkers and therapeutic targets in acute lymphoblastic leukemia (ALL). In this study, we conducted a systematic analysis of recurrent somatic non-coding single nucleotide variants (SNVs) in pediatric B-cell precursor (BCP) ALL. We leveraged whole genome sequencing (WGS) data from 345 pediatric BCP ALL cases, representing all major genetic subtypes and identified 346 mutational hotspots that harbored somatic SNVs in at least three cases. Through the integration of paired RNA sequencing along with published ChIP-seq and ATAC-seq data, we found 128 non-coding hotspots associated with differentially expressed genes nearby, which were enriched for cis-regulatory elements, demonstrating the effectiveness of multi-omics integration in distinguishing pathogenic mutations from passengers. We identified one mutational hotspot that was associated with increased expression of the leukemia-associated gene NRAS in three primary ALLs. Micro-C analysis in the leukemia cell line demonstrated interactions between the hotspot region and NRAS regulatory elements. Dual luciferase assays indicated that the mutations disrupted regulatory interactions and CRISPR-mediated deletion of the region significantly upregulated NRAS, confirming the hypothesized regulatory link. Altogether, we provide new insights into the functional roles of non-coding mutations in leukemia.

Gastrointestinal stromal tumors (GISTs) span a broad clinical spectrum, from indolent neoplasms to life-threatening metastatic tumors. A persistent limitation of current risk stratification systems is that a subset of GISTs is graded as low-risk but nevertheless metastasizes. Therefore, new predictive factors that improve risk stratification are needed. In this exploratory study, we investigated the potential of genome-wide DNA methylation profiling and copy number variation (CNV) analysis as additional prognostic tools for GISTs. We collected a cohort of 28 patients with GIST diagnosed between 2001 and 2022, with available follow-up and molecular data. This included 15 patients without progressive disease (seven low-risk and eight moderate- to high-risk GISTs) and 13 with progressive disease. Among those with progression, eight experienced recurrence or metastasis post-surgery (one low-risk, seven high-risk GISTs), while five had metastatic disease at initial diagnosis. Risk stratification was determined according to Miettinen's criteria. Genome-wide DNA methylation data and CNV plots were generated from imatinib-naïve primary GISTs using the Illumina Infinium MethylationEPIC BeadChip array. Unsupervised cluster analysis revealed distinct DNA methylation patterns predominantly associated with anatomical location and genotype. Differential DNA methylation analysis comparing primary gastric GISTs associated with and without progressive disease showed 8 differentially methylated regions spanning the coding and promoter areas of 6 genes. CNV analysis demonstrated that GISTs associated with progressive disease had the most CNVs, whereas low-risk, non-progressive GISTs had the fewest. Despite the limited sample size, this exploratory study indicates that genome-wide DNA methylation profiling and CNV analysis could enhance GIST risk stratification.

Approximately 10%–15% of all lung cancers arise in non-smokers. Although there are no established aetiological factors, non-smokers with a family history of cancer have an increased risk of lung cancer, implying host genetic factors in lung cancer susceptibility. We sought to identify, in a cohort of 75 patients recruited before lung lobectomy, germline alterations with a strong association with lung cancer. Whole-exome sequencing was performed on genomic DNA from peripheral blood. Six resources were used to select pathogenic germline variants with strong clinical significance. In total, 33 pathogenic or likely pathogenic variants in 31 genes were identified. Of these, 13 were located in cancer-predisposing genes (nine were lung cancer drivers), most of which were involved in DNA repair mechanisms and diseases of metabolism. Among DNA repair-related genes, BRCA1 and BRCA2, and ATM have also been identified in other studies on non-smokers. Our results strongly support the hypothesis that a number of non-smoker lung cancer patients carry germline variants in cancer-predisposing genes, suggesting that lung cancer patients, particularly non-smokers, should be considered for germline molecular testing.

Approximately 10% of Ph-Like patients have ABL class gene fusions, which include the FIP1L1::PDGFRA rearrangement. We report a case of a pediatric patient with Ph-like B-lymphoblastic leukemia (B-LL) with a FIP1L1::PDGFRA fusion and their treatment course using a combination of chemotherapy and targeted therapy with imatinib. A 10-year-old female presented with lethargy, palpitations, and fevers. She had pancytopenia, no eosinophilia, and flow cytometry consistent with B-LL. FISH identified a CHIC2 deletion, suggestive of FIP1L1::PDGFRA fusion, confirmed on next-generation RNA sequencing. The patient commenced targeted therapy with imatinib, which she continued until completion of standard chemotherapy per COG AALL1732. She remains in remission 6 months post-completion of therapy. B-ALL with a FIP1L1::PDGFRA fusion is extremely rare, particularly in pediatrics. FIP1L1::PDGFRA rearrangements can be difficult to detect on routine testing and may not always be seen in association with eosinophilia. Identification of FIP1L1::PDGFRA rearrangements is important as they enable treatment with a tyrosine kinase inhibitor, which has significantly improved the overall prognosis for PDGFRA-rearranged neoplasms. Prospective studies assessing imatinib dosage, duration, and long-term safety are warranted in this cohort.