Recent genomic analyses of pathologically-defined tumor types identify “within-a-tissue” disease subtypes. However, the extent to which genomic signatures are shared across tissues is still unclear. We performed an integrative analysis using five genome-wide platforms and one proteomic platform on 3,527 specimens from 12 cancer types, revealing a unified classification into 11 major subtypes. Five subtypes were nearly identical to their tissue-of-origin counterparts, but several distinct cancer types were found to converge into common subtypes. Lung squamous, head & neck, and a subset of bladder cancers coalesced into one subtype typified by TP53 alterations, TP63 amplifications, and high expression of immune and proliferation pathway genes. Of note, bladder cancers split into three pan-cancer subtypes. The multi-platform classification, while correlated with tissue-of-origin, provides independent information for predicting clinical outcomes. All datasets are available for data-mining from a unified resource to support further biological discoveries and insights into novel therapeutic strategies.
Previous studies have established that a subset of head and neck tumors contains human papillomavirus (HPV) sequences and that HPV-driven head and neck cancers display distinct biological and clinical features. HPV is known to drive cancer by the actions of the E6 and E7 oncoproteins, but the molecular architecture of HPV infection and its interaction with the host genome in head and neck cancers have not been comprehensively described. We profiled a cohort of 279 head and neck cancers with next generation RNA and DNA sequencing and show that 35 (12.5%) tumors displayed evidence of high-risk HPV types 16, 33, or 35. Twentyfive cases had integration of the viral genome into one or more locations in the human genome with statistical enrichment for genic regions. Integrations had a marked impact on the human genome and were associated with alterations in DNA copy number, mRNA transcript abundance and splicing, and both inter-and intrachromosomal rearrangements. Many of these events involved genes with documented roles in cancer. Cancers with integrated vs. nonintegrated HPV displayed different patterns of DNA methylation and both human and viral gene expressions. Together, these data provide insight into the mechanisms by which HPV interacts with the human genome beyond expression of viral oncoproteins and suggest that specific integration events are an integral component of viral oncogenesis.cancer | head and neck | papilloma virus | genome rearrangement | integration sites H ead and neck cancer (HNC) is a heterogeneous group of tumors characterized by a common anatomic origin, and most such tumors develop from within the mucosa and are classified as head and neck squamous cell carcinomas (HNSCCs) (1). HNSCC, the sixth most common cancer diagnosed worldwide and the eighth most common cause of cancer death (2), is frequently associated with human papillomavirus (HPV) infection (3, 4). Depending on the anatomic site of the tumor, HPV prevalence is estimated at 23-36% (5). HPV-positive HNSCCs form a distinct subset of HNCs that differs from HPV-negative HNSCCs in tumor biology and clinical characteristics, including superior clinical outcomes (6-9).The molecular pathogenesis of HPV-driven HNSCC also seems distinct from HPV-negative tumors, with previous studies showing a divergent spectrum of alterations in gene expression, mutations, amplifications, and deletions as well as distinct epigenome alterations (10-15). HPV is known to drive tumorigenesis through the actions of its major oncoproteins E6 and E7, which target numerous cellular pathways, including inactivation of p53 and the retinoblastoma (Rb) protein (16-18). Together with E5, they also play an important role in immune evasion, being involved in both innate and adaptive immunity (19,20).Initially after infection, HPV is identified in circular extrachromosomal particles or episomes. A critical step in progression to cancer is the integration of viral DNA into the host cell Significance A significant proportion of head and neck cancer is driven by human papil...
Reservoirs of infectious HIV-1 persist despite years of combination antiretroviral therapy and make curing HIV-1 infections a major challenge. Most of the proviral DNA resides in CD4+T cells. Some of these CD4+T cells are clonally expanded; most of the proviruses are defective. It is not known if any of the clonally expanded cells carry replication-competent proviruses. We report that a highly expanded CD4+ T-cell clone contains an intact provirus. The highly expanded clone produced infectious virus that was detected as persistent plasma viremia during cART in an HIV-1–infected patient who had squamous cell cancer. Cells containing the intact provirus were widely distributed and significantly enriched in cancer metastases. These results show that clonally expanded CD4+T cells can be a reservoir of infectious HIV-1.
Summary Molecular alterations involving PI3K/AKT/mTOR pathway (including mutation, copy number, protein, or RNA) were examined across 11219 human cancers representing 32 major types. Within specific mutated genes, frequency, mutation hotspot residues, in silico predictions, and functional assays were all informative in distinguishing the subset of genetic variants more likely to have functional relevance. Multiple oncogenic pathways including PI3K/AKT/mTOR converged on similar sets of downstream transcriptional targets. In addition to mutation, structural variations and partial copy losses involving PTEN and STK11 showed evidence for having functional relevance. A substantial fraction of cancers showed high mTOR pathway activity without an associated canonical genetic or genomic alteration, including cancers harboring IDH1 or VHL mutations, suggesting multiple mechanisms for pathway activation.
SUMMARY This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smoking and/or human papillomavirus (HPV). SCCs harbor 3q, 5p, and other recurrent chromosomal copy-number alterations (CNAs), DNA mutations, and/or aberrant methylation of genes and microRNAs, which are correlated with the expression of multi-gene programs linked to squamous cell stemness, epithelial-to-mesenchymal differentiation, growth, genomic integrity, oxidative damage, death, and inflammation. Low-CNA SCCs tended to be HPV(+) and display hypermethylation with repression of TET1 demethylase and FANCF, previously linked to predisposition to SCC, or harbor mutations affecting CASP8, RAS-MAPK pathways, chromatin modifiers, and immunoregulatory molecules. We uncovered hypomethylation of the alternative promoter that drives expression of the ΔNp63 oncogene and embedded miR944. Co-expression of immune checkpoint, T-regulatory, and Myeloid suppressor cells signatures may explain reduced efficacy of immune therapy. These findings support possibilities for molecular classification and therapeutic approaches.
We previously reported that human head and neck squamous cell carcinomas (HNSCCs) express the pro-inflammatory and pro-angiogenic cytokines interleukin (IL)-1alpha, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor in vitro and in vivo. The promoter region of the genes encoding these cytokines include binding sites for the transcription factors nuclear factor (NF) kappaB/Rel A, activator protein-1 (AP-1), and CCAAT enhancer-binding protein beta (C/EBPbeta, or NF-IL6), which have been reported to contribute to activation of these cytokine genes. In the study presented here, we examined the activation, composition, and function of these transcription factors in HNSCC cell lines that express pro-inflammatory cytokines, by using electrophoretic mobility shift and reporter-gene assays. Constitutive activation of NF-kappaB, AP-1, and NF-IL6 DNA-binding proteins was detected. Supershift analysis with antibodies specific for NF-kappaB, AP-1, and NF-IL6 binding proteins showed that the NF-kappaB-binding protein included p65/Rel A and p50; AP-1 activity included c-jun, junB, junD, and Fra-1; and NF-IL6 included C/EBPbeta. Mutational analysis of the NF-kappaB, AP-1, and NF-IL6 sites in the IL-8 promoter region showed that NF-kappaB and AP-1 sites contributed to constitutive IL-8 reporter activity in HNSCC. HNSCC lines that exhibited increased IL-8 secretion relative to simian virus 40-immortalized and primary keratinocyte cell lines also demonstrated a concordant increase in NF-kappaB reporter activity relative to nonmalignant keratinocytes. We concluded that the early transcription factors NF-kappaB, AP-1, and NF-IL6 are constitutively activated in human HNSCC cell lines and that NF-kappaB and AP-1 promote expression of the pro-inflammatory and pro-angiogenic cytokine IL-8 in HNSCC. The demonstration of the activation of these transcription factors will be helpful in defining the identity and role of these and other early gene products that contribute to pathogenesis of the malignant phenotype in HNSCC and in defining potential targets for pharmacologic and molecular therapy of HNSCC. Mol. Carcinog. 26:119-129, 1999. Published 1999 Wiley-Liss, Inc.
Nuclear factor-nB (NF-nB) is a signal transcription factor that has emerged as an important modulator of altered gene programs and malignant phenotype in development of cancer. Major carcinogens and oncogenic viruses induce NF-nB activation, and a variety of subsequent oncogenic events contribute to a progressive increase in constitutive NF-nB activation as an important common pathway in most forms of cancer. NF-nB target genes promote tumor cell proliferation, survival, migration, inflammation, and angiogenesis. Inhibition of NF-nB has been found to be an important mechanism of action of steroids, nonsteroidal anti-inflammatory drugs, and natural and synthetic compounds that show therapeutic and preventive activity. Newer agents targeting the proteasome, inhibitor-nB kinase, and other upstream kinases involved in NF-nB activation have shown anticancer activity in clinical or preclinical studies.
Key words: EGFR; NF-B; AP-1; IL-8; VEGF; PI3K; MEK; HNSCCIncreased angiogenesis is critical to tumor progression and metastasis, and we and others have shown that expression of members of the C-X-C cytokine and vascular endothelial growth factor families such as IL-8, growth regulated oncogene-1 (Gro 1) and VEGF can promote angiogenesis, tumorigenesis and metastatic tumor progression. 1-3 The expression of multiple factors with proangiogenic activity by cancer cells poses a significant obstacle to effective therapy with agents targeted toward individual factors and receptors. Identification of common mechanism(s) underlying expression of such a diversity of factors could guide the development of therapy using fewer selective agents. We previously observed that IL-8, VEGF and other cytokines are coexpressed and often vary concurrently in serum and supernatants from cell lines from different patients with head and neck squamous cell carcinoma (HNSCC), 4,5 suggesting that these factors could be regulated by common signal pathways or transcription factors.Examination of the regulatory region of many proinflammatory cytokines and proangiogenic factors reveals that they share common promoter sites for transcription factors such as nuclear factor-B (NF-B) and/or activator protein-1 (AP-1), which can be activated by injury, cytokines and growth factors. 6 We found that differences in expression of these cytokines in different cancers was often related to differences in constitutive activation of both NF-B and AP-1. 6 Inhibition of NF-B activation by expression of a dominant negative inhibitor-B or pharmacologic agents was found to inhibit expression of IL-8 and other proinflammatory and proangiogenic cytokines, 7-10 as well as tumorigenesis and angiogenesis in vivo. 7,9 Inhibition of activation of extracellular signalregulated kinase (ERK) and AP-1 with antagonists of mitogenactivated/extracellular signal-regulated kinase (MEK) partially inhibited expression of both IL-8 and VEGF. 10 These results provided evidence that at least 2 signal pathways upstream of NF-B and AP-1 make important contributions to expression of these angiogenesis factors.We have recently examined the contribution of several factors that may contribute to upstream signal activation of NF-B and AP-1 and expression of IL-8 and VEGF. We found that IL-1␣ expressed by HNSCC promotes autocrine activation of NF-B and AP-1, expression of IL-8 and cell survival. 11 Expression of IL-1 receptor antagonist inhibited NF-B reporter activity and IL-8 expression by 60 -80%, indicating that IL-1␣ is a major contributor to constitutive activation of NF-B and IL-8. HNSCC were also found to express c-MET, a receptor tyrosine kinase for hepatocyte growth factor/scatter factor (HGF/SF). 12 Increased expression of HGF/SF was detected together with IL-8 and VEGF in serum of patients with HNSCC, and recombinant HGF and HGF from stromal fibroblasts was found to further induce IL-8 and VEGF expression by human HNSCC lines. Inhibitors of MEK and Abbreviations: AP-1, activator...
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