ABSTRACT: Genomic and transcriptomic data from a cohort of 35 RAS wild-type colorectal cancers. All 35 cases were DNA sequenced at baseline (BL) before treatment with single agent cetuximab. Progressive disease (PD)-biopsies were taken shortly after radiological progression and successfully exome sequenced from 24/35 cases. mRNA sequencing is available for 25 Baseline and 15 PD samples. ctDNA from 9 cases that progressed after prolonged cetuximab benefit were also deep sequenced.
Project description:We performed genomic and transcriptomic analysis of seven cases of molecular Burkitt lymphoma (mBL) developed in immunosuppressed patients who underwent solid organ transplantation. Interestingly, three cases (43%) were MYC-translocation-negative and revealed the 11q-gain/loss aberration recently identified in 3% of mBL developed in immunocompetent hosts.1 Based on array CGH data, minimal gain and loss regions of 11q (MGR/~4Mb and MLR/~13.5Mb, respectively) were defined and integrative genomic and transcriptomic analysis identified 35 differentially expressed genes, when compared with classic BL. All 16 MGR-dysregulated genes were upregulated, including cancer related USP2, CBL and PAFAH1B2. As expected, all 19 MGL-dysregulated genes were downregulated and two of them, TBRG1 and EI24, are potential tumor suppressor genes. Interestingly, the vast majority of dysregulated 11q23-q25 genes are involved in the MYC and TP53 networks. We hypothesize that the 11q-gain/loss aberration represents a “molecular variant” of t(8q24/MYC) and affects the same pathological pathways as the MYC oncogene. Seven cases of PTLD with BL features were selected from a cohort of 174 posttransplant patients diagnosed with PTLD between 1989 and 2012 at the University Hospitals of KU Leuven (Leuven, Belgium). In addition, five classic BL cases were selected as immunocompetent controls (IC-BL). Morphologic, immunophenotypic, clinical and cytogenetic characteristics of the selected cases were reviewed.
Project description:We performed genomic and transcriptomic analysis of seven cases of molecular Burkitt lymphoma (mBL) developed in immunosuppressed patients who underwent solid organ transplantation. Interestingly, three cases (43%) were MYC-translocation-negative and revealed the 11q-gain/loss aberration recently identified in 3% of mBL developed in immunocompetent hosts.1 Based on array CGH data, minimal gain and loss regions of 11q (MGR/~4Mb and MLR/~13.5Mb, respectively) were defined and integrative genomic and transcriptomic analysis identified 35 differentially expressed genes, when compared with classic BL. All 16 MGR-dysregulated genes were upregulated, including cancer related USP2, CBL and PAFAH1B2. As expected, all 19 MGL-dysregulated genes were downregulated and two of them, TBRG1 and EI24, are potential tumor suppressor genes. Interestingly, the vast majority of dysregulated 11q23-q25 genes are involved in the MYC and TP53 networks. We hypothesize that the 11q-gain/loss aberration represents a M-bM-^@M-^\molecular variantM-bM-^@M-^] of t(8q24/MYC) and affects the same pathological pathways as the MYC oncogene. Seven cases of PTLD with BL features were selected from a cohort of 174 posttransplant patients diagnosed with PTLD between 1989 and 2012 at the University Hospitals of KU Leuven (Leuven, Belgium). In addition, five classic BL cases were selected as immunocompetent controls (IC-BL). Morphologic, immunophenotypic, clinical and cytogenetic characteristics of the selected cases were reviewed.
Project description:Most head and neck cancer (HNC) patients are resistant to cetuximab, an antibody against the epithelial growth factor receptor. Such therapy resistance is known to be mediated, in part, by stromal cells surrounding the tumor cells; however, the mechanisms underlying such a resistance phenotype remain unclear. To identify the mechanisms underlying cetuximab resistance in an unbiased manner, RNA-sequencing (RNA-seq) of HNC patient-derived xenografts (PDXs) was performed. Comparing the gene expression of HNC-PDXs before and after treatment with cetuximab indicated that the TGF-beta signaling pathway was upregulated in the stromal cells of PDXs that progressed to cetuximab (CetuximabProg-PDX). However, in PDXs that were extremely sensitive to cetuximab, and when tumors shrunk following cetuximab treatment (CetuximabSen-PDX), the TGF-beta pathway was downregulated in the stromal compartment. Histopathological analysis of PDXs showed that in CetuximabProg-PDX, TGF-beta-activation was detected in cancer-associated fibroblasts (CAFs). These TGF-beta-activated CAFs were sufficient to limit cetuximab efficacy in vitro and in vivo. Moreover, blocking the TGF-beta pathway using the SMAD3 inhibitor, SIS3, enhanced cetuximab efficacy and prevented the progression of CetuximabProg-PDX. Altogether, our findings indicate, for the first time, that TGF-beta-activated CAFs play a role in limiting cetuximab efficacy in HNC.
Project description:This study is multi-omics study of a Asian longitudinal metastatic breast cancer (MBC) cohort treated with palbociclib plus endocrine therapy. It contains NGS of baseline (BL) and progressive disease (PD) from 70 patients, consisting of 79 tumor/normal matched whole exome sequencing (WES) from 62 patients and 90 tumor whole transcriptome sequecing samples (WTS) from 70 patients. There were 56 BL biopsies profiled by WES and 64 by WTS; 23 PD biopsies were profiled by WES and 26 by WTS. Twenty and 23 patients had paired BL and PD biopsies profiled by WES and WTS, respectively.
Project description:Sporadic Burkitt lymphoma (sBL) can be delineated from diffuse large B-cell lymphoma (DLBCL) by a very homogeneous mRNA expression signature. However, it remained unclear whether all three BL variants – sBL, endemic BL (eBL) and immunodeficiency-associated BL (HIV-BL) – represent a uniform biological entity despite their differences in geographical occurrence, association with immunodeficiency and/or incidence of EBV infection. To address this issue, we generated micro RNA (miRNA) profiles from 18 eBL, 31 sBL and 15 HIV-BL cases. In addition, we analyzed the miRNA expression of 86 DLBCL to determine whether miRNA profiles recapitulate the molecular differences between BL and DLBCL evidenced by mRNA profiling. A signature of 38 miRNAs enriched in MYC regulated and NF-kB pathway associated miRNAs was obtained that differentiated BL from DLBCL. The miRNA profiles of sBL and eBL displayed only 6 differentially expressed miRNAs, whereas HIV and EBV infection had no impact on the miRNA profile of BL. In conclusion, miRNA profiling confirms that BL and DLBCL represent distinct lymphoma categories and demonstrates that the three BL variants are representatives of the same biological entity with only marginal miRNA expression differences between eBL and sBL. Archival tumor specimens of 86 diffuse large B-cell lymphoma (DLBCL) and 64 Burkitt lymphoma (BL) patients were obtained. The DLBCL samples have previously been reviewed by a panel of expert hematopathologists and their clinical data were published as part of the RiCOVER-60 trial. The diagnosis of all BL cases was confirmed by histopathology review according to the criteria of the WHO classification. Based on their geographical origin, 31 BL samples were designated as sporadic BL (sBL) and 18 samples as endemic BL (eBL). Fifteen BL cases were diagnosed as immunodeficiency-associated BL (HIV-BL). Of the 18 eBL 14 cases were EBV+ (87.5%), 2 samples were EBV- (12.5%) and for 2 eBL cases the EBV status was unknown. Of the sBL samples 26 were EBV- (86.7%), 4 cases were EBV+ (13.3%) and for 1 case the EBV status was not evaluable. Among the HIV-BL 5 (33.3%) were EBV+, whereas 10 (66.7%) were EBV-.
Project description:Anti-EGFR antibodies are effective in therapies for late-stage colorectal cancer (CRC); however, many tumours are unresponsive or develop resistance. We performed genomic analysis of intrinsic and acquired resistance to anti-EGFR therapy in prospectively collected tumour samples from 25 CRC patients receiving cetuximab (an EGFR inhibitor). Of 25 CRC patients, 13 displayed intrinsic resistance to cetuximab; 12 were intrinsically sensitive. We obtained six re-biopsy samples at acquired resistance from the intrinsically sensitive patients. NCOA4–RET and LMNA–NTRK1 fusions and NRG1 and GNAS amplifications were found in intrinsic-resistant patients. In cetuximab-sensitive patients, we found KRAS K117N and A146T mutations in addition to BRAF V600E, AKT1 E17K, PIK3CA E542K, and FGFR1 or ERBB2 amplifications. The comparison between baseline and acquired-resistant tumours revealed an extreme shift in variant allele frequency of somatic variants, suggesting that cetuximab exposure dramatically selected for rare resistant subclones that were initially undetectable. There was also an increase in epithelial-to-mesenchymal transition at acquired resistance, with a reduction in the immune infiltrate. Furthermore, characterization of an acquired-resistant, patient-derived cell line showed that PI3K/mTOR inhibition could rescue cetuximab resistance. Thus, we uncovered novel genomic alterations that elucidate the mechanisms of sensitivity and resistance to anti-EGFR therapy in metastatic CRC patients.
Project description:MicroRNAs (miRNAs) are small non-coding RNAs involved in the posttranscriptional regulation of gene expression. Deregulated miRNA levels have been reported in Burkitt lymphoma (BL) compared to normal B cells and a number of miRNA target genes have been identified in BL cell lines. Here, we determined for the first time the miRNA targetomes of primary BL tumors in comparison with normal B cells. AGO2-RNA immunoprecipitation (AGO2-RIP) in two frozen diagnostic BL tissue samples and three CD19+ B-cell samples isolated from routinely removed tonsils revealed distinct miRNA targetomes of BL and normal B cells. Targets of the miR-17~92 cluster were significantly more frequently AGO2-IP enriched in BL while targets of miR-29 and miR-150 were more frequently AGO2-IP enriched in normal B cells. Furthermore, we showed that miRNA target genes in BL are mainly involved in cell cycle and cell death. Immunohistochemistry on BL tumor samples and tonsil tissues confirmed altered protein levels for two out of six selected miRNA targets, in line with the differential AGO2-IP enrichment between BL and normal B cells. A comparison of AGO2-IP enriched genes in primary BL cases with BL cell lines indicated that approximately half of the miRNA targets may be missed in studies using BL cell lines, while almost 60% of miRNA target genes identified in cell lines were not AGO2-IP enriched in primary BL cases. Our results demonstrate both the necessity and feasibility of studying miRNA-target interactions in primary tumors.
Project description:We conducted Ribo-Zero RNA-Seq studies on rat hippocampus to elucidate changes in RNA expression in the hippocampus under physiological conditions such as acute stress and circadian variation. Rats were subjected to 15-min forced swim (FS) session and hippocampus tissue was collected at 30, 60, 120, 180 or 360 minutes after the onset of swimming. Tissues were also collected under early morning baseline (BL AM) or late afternoon baseline (BL PM) conditions. Based on this analysis, we have identified many genes that are differentially expressed as a result of acute stress exposure and circadian variation.
Project description:Overall, the genetic profile of aggressive B-cell NHL in CAYA in the spectrum of BL and DLBCL is heterogeneous. MYC-R cases mostly displayed a molecular profile close to BL regardless of their morphology, whereas MYC-non-R had a more heterogeneous genetic landscape resembling DLBCL.