Project description:Glioblastoma multiforme (GBM) is the most frequent and aggressive primary brain tumor in adults. Despite extensive therapy the prognosis for GBM patients remains poor and the extraordinary therapy resistance has been attributed to intertumoral heterogeneity of glioblastoma. Different prognostic relevant GBM tumor subtypes have been identified based on their molecular profile. This approach, however, neglects the heterogeneity within individual tumors, that is, the intratumoral heterogeneity. Here, we detected the regional immunoreactivity by immunohistochemistry and immunofluorescence using nine different markers on resected GBM specimens (IDH wildtype, WHO grade IV). We found repetitive expression profiles, that could be classified into clusters. These clusters could then be assigned to five pathophysiologically relevant groups that reflect the previously described subclasses of GBM, including mesenchymal, classical, and proneural subtype. Our data indicate the presence of tumor differentiations and tumor subclasses that occur within individual tumors, and might therefore contribute to develop adapted, individual-based therapies.
Project description:BackgroundNext-generation sequencing is revealing genomic heterogeneity in localized prostate cancer (CaP). Incomplete sampling of CaP multiclonality has limited the implications for molecular subtyping, stratification, and systemic treatment.ObjectiveTo determine the impact of genomic and transcriptomic diversity within and among intraprostatic CaP foci on CaP molecular taxonomy, predictors of progression, and actionable therapeutic targets.Design, setting, and participantsFour consecutive patients with clinically localized National Comprehensive Cancer Network intermediate- or high-risk CaP who did not receive neoadjuvant therapy underwent radical prostatectomy at Roswell Park Cancer Institute in June-July 2014. Presurgical information on CaP content and a customized tissue procurement procedure were used to isolate nonmicroscopic and noncontiguous CaP foci in radical prostatectomy specimens. Three cores were obtained from the index lesion and one core from smaller lesions. RNA and DNA were extracted simultaneously from 26 cores with ≥90% CaP content and analyzed using whole-exome sequencing, single-nucleotide polymorphism arrays, and RNA sequencing.Outcome measurements and statistical analysisSomatic mutations, copy number alternations, gene expression, gene fusions, and phylogeny were defined. The impact of genomic alterations on CaP molecular classification, gene sets measured in Oncotype DX, Prolaris, and Decipher assays, and androgen receptor activity among CaP cores was determined.Results and limitationsThere was considerable variability in genomic alterations among CaP cores, and between RNA- and DNA-based platforms. Heterogeneity was found in molecular grouping of individual CaP foci and the activity of gene sets underlying the assays for risk stratification and androgen receptor activity, and was validated in independent genomic data sets. Determination of the implications for clinical decision-making requires follow-up studies.ConclusionsGenomic make-up varies widely among CaP foci, so care should be taken when making treatment decisions based on a single biopsy or index lesions.Patient summaryWe examined the molecular composition of individual cancers in a patient's prostate. We found a lot of genetic diversity among these cancers, and concluded that information from a single cancer biopsy is not sufficient to guide treatment decisions.
Project description:Malignant pleural mesothelioma (MPM) is a deadly pleural malignancy with over 90% mortality within five years and a median survival of approximately 7 months without treatment. The current first-line chemotherapy, a combination of pemetrexed and cisplatin, modestly extends survival, with the addition of bevacizumab offering a further 2-month benefit. Radiation therapy, while not effective as a primary treatment due to the extensive field required, plays a role in multimodal approaches or as localized therapy. The diversity in patient outcomes and responses to treatments indicates significant tumor heterogeneity in MPM, underscoring the need for therapies that consider this variability and target the molecular specifics of individual MPM cases. Tumor heterogeneity is observed at both intertumor and intratumor levels, encompassing tumor cells and their microenvironments. Molecular profiling studies have further highlighted this heterogeneity, complicating the identification of a unique biomarker for MPM.
Project description:While molecular subgrouping has revolutionized medulloblastoma classification, the extent of heterogeneity within subgroups is unknown. Similarity network fusion (SNF) applied to genome-wide DNA methylation and gene expression data across 763 primary samples identifies very homogeneous clusters of patients, supporting the presence of medulloblastoma subtypes. After integration of somatic copy-number alterations, and clinical features specific to each cluster, we identify 12 different subtypes of medulloblastoma. Integrative analysis using SNF further delineates group 3 from group 4 medulloblastoma, which is not as readily apparent through analyses of individual data types. Two clear subtypes of infants with Sonic Hedgehog medulloblastoma with disparate outcomes and biology are identified. Medulloblastoma subtypes identified through integrative clustering have important implications for stratification of future clinical trials.
Project description:BackgroundA major barrier to effective treatment of glioblastoma (GBM) is the large intertumoral heterogeneity at the genetic and cellular level. In early phase clinical trials, patient heterogeneity in response to therapy is commonly observed; however, how tumor heterogeneity is reflected in individual drug sensitivities in the treatment-naïve glioblastoma stem cells (GSC) is unclear.MethodsWe cultured 12 patient-derived primary GBMs as tumorspheres and validated tumor stem cell properties by functional assays. Using automated high-throughput screening (HTS), we evaluated sensitivity to 461 anticancer drugs in a collection covering most FDA-approved anticancer drugs and investigational compounds with a broad range of molecular targets. Statistical analyses were performed using one-way ANOVA and Spearman correlation.ResultsAlthough tumor stem cell properties were confirmed in GSC cultures, their in vitro and in vivo morphology and behavior displayed considerable tumor-to-tumor variability. Drug screening revealed significant differences in the sensitivity to anticancer drugs (p < 0.0001). The patient-specific vulnerabilities to anticancer drugs displayed a heterogeneous pattern. They represented a variety of mechanistic drug classes, including apoptotic modulators, conventional chemotherapies, and inhibitors of histone deacetylases, heat shock proteins, proteasomes and different kinases. However, the individual GSC cultures displayed high biological consistency in drug sensitivity patterns within a class of drugs. An independent laboratory confirmed individual drug responses.ConclusionsThis study demonstrates that patient-derived and treatment-naïve GSC cultures maintain patient-specific traits and display intertumoral heterogeneity in drug sensitivity to anticancer drugs. The heterogeneity in patient-specific drug responses highlights the difficulty in applying targeted treatment strategies at the population level to GBM patients. However, HTS can be applied to uncover patient-specific drug sensitivities for functional precision medicine.
Project description:PURPOSE:Genetic intratumoral heterogeneity has a profound influence on the selection of clinical treatment strategies and on addressing resistance to targeted therapy. The purpose of this study was to explore the potential effect of intratumoral heterogeneity on both genetic and pathologic characteristics of ALK-rearranged lung adenocarcinoma (LADC). METHODS:We tested ALK fusions and EGFR mutations in 629 patients with LADC by using laser-capture microdissection to capture spatially separated tumor cell subpopulations in various adenocarcinoma subtypes and to test for ALK fusions and EGFR mutations in ALK-rearranged, EGFR-mutated, and ALK/EGFR coaltered LADCs to compare the oncogenic driver status between different tumor cell subpopulations in the same primary tumor. RESULTS:Among the 629 patients, 30 (4.8%) had ALK fusions, 364 (57.9%) had EGFR mutations, and two had ALK fusions that coexisted with EGFR mutations. Intratumoral heterogeneity of ALK fusions were identified in nine patients by reverse-transcriptase polymerase chain reaction. In the two patients with an ALK/EGFR coaltered status, genetic intratumoral heterogeneity was observed both between different growth patterns and within the same growth pattern. The relative abundance of ALK and EGFR alterations was different in the same captured area. ALK fusions were positively associated with a micropapillary pattern (P = .002) and were negatively associated with a lepidic pattern (P = .008) in an expanded statistical analysis of 900 individual adenocarcinoma components, although they appeared to be more common in acinar-predominant LADCs in the analysis of 629 patients. CONCLUSION:Intratumoral genetic heterogeneity was demonstrated to coexist with histologic heterogeneity in both single-driver and ALK/EGFR coaltered LADCs. Altered oncogenic drivers in spatially separated subclones of the same tumor may be different.
Project description:Combining whole exome sequencing, transcriptome profiling, and T cell repertoire analysis, we investigate the spatial features of surgically-removed biopsies from multiple loci in tumor masses of 15 patients with non-small cell lung cancer (NSCLC). This revealed that the immune microenvironment has high spatial heterogeneity such that intratumoral regional variation is as large as inter-personal variation. While the local total mutational burden (TMB) is associated with local T-cell clonal expansion, local anti-tumor cytotoxicity does not directly correlate with neoantigen abundance. Together, these findings caution against that immunological signatures can be predicted solely from TMB or microenvironmental analysis from a single locus biopsy.
Project description:The aim of this study was to investigate the effect of VEGF targeted therapy (sunitinib) on intratumoral heterogeneity (ITH) in metastatic clear cell renal cancer (mRCC). 138 samples from patients with clear cell renal cell carcinoma, including biological replicates of nephrectomy samples. RNA extracted fresh frozen tissue samples.
Project description:Non-small cell lung cancers (NSCLC) that have developed resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI), including gefitinib and erlotinib, are clinically linked to an epithelial-to-mesenchymal transition (EMT) phenotype. Here, we examined whether modulating EMT maintains the responsiveness of EGFR-mutated NSCLCs to EGFR TKI therapy. Using human NSCLC cell lines harboring mutated EGFR and a transgenic mouse model of lung cancer driven by mutant EGFR (EGFR-Del19-T790M), we demonstrate that EGFR inhibition induces TGFβ secretion followed by SMAD pathway activation, an event that promotes EMT. Chronic exposure of EGFR-mutated NSCLC cells to TGFβ was sufficient to induce EMT and resistance to EGFR TKI treatment. Furthermore, NSCLC HCC4006 cells with acquired resistance to gefitinib were characterized by a mesenchymal phenotype and displayed a higher prevalence of the EGFR T790M mutated allele. Notably, combined inhibition of EGFR and the TGFβ receptor in HCC4006 cells prevented EMT but was not sufficient to prevent acquired gefitinib resistance because of an increased emergence of the EGFR T790M allele compared with cells treated with gefitinib alone. Conversely, another independent NSCLC cell line, PC9, reproducibly developed EGFR T790M mutations as the primary mechanism underlying EGFR TKI resistance, even though the prevalence of the mutant allele was lower than that in HCC4006 cells. Thus, our findings underscore heterogeneity within NSCLC cells lines harboring EGFR kinase domain mutations that give rise to divergent resistance mechanisms in response to treatment and anticipate the complexity of EMT suppression as a therapeutic strategy.
Project description:The aim of this study was to investigate the effect of VEGF targeted therapy (sunitinib) on intratumoral heterogeneity (ITH) in metastatic clear cell renal cancer (mRCC). To explore ITH in detail, multiple tumor samples were taken from the primary renal tumors of mRCC patients who were sunitinib treated (n=23) or untreated (n=23). ITH of pathological grade, DNA (using array-based comparative genomic hybridisation), RNA (Illumina Beadarray) and protein (reverse phase protein array) were evaluated. Tumor grade heterogeneity was greater in treated compared to untreated tumors (P=0.002). Unsupervised and supervised analysis, for renal cancer driver, hypoxia and stromal gene signatures, was then performed. In untreated patient tumor samples, significant ITH occurred in chromosomal aberrations, RNA and protein expression, with clustering of DNA and RNA correlating for individual patients. In unsupervised analysis sunitinib therapy was not associated with increased ITH in DNA or RNA. However there was an increase in ITH for the driver mutation and hypoxia gene signatures (DNA and RNA) as well as increasing variability of protein expression with treatment (p<0.05). Despite this variability, significant chromosomal and RNA changes to targets of sunitinib, such as VHL, PBRM1 and CAIX, occurred in the treated samples. Together these findings suggest that sunitinib treatment has significant effects on the expression and ITH of key tumor and treatment specific genes. The results do not support the hypothesis that resistant clones are selected and predominate after initiation of targeted therapy; instead it appears that an initial clonal diversification occurs, supporting the hypothesis of polyclonal drug resistance. 128 samples from patients with clear cell renal cell carcinoma, including biological replicates of nephrectomy samples. Source of samples includes both biopsy and nephrectomy. DNA extracted from FFPE and fresh frozen tissue samples.