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Knowledge about the morphologic and molecular characteristics of cervical squamous cell carcinomas (CSCCs) associated with uterine prolapse is very limited. Detailed histopathological and immunohistochemical (p16, p53, and cytokeratin 17), as well as molecular evaluation for human papillomavirus (HPV)-DNA and p53-mutational analyses in 4 consecutive CSCCs associated with uterine prolapse with definition of a hitherto not well-described HPV-independent/p53abnormal precursor lesion (HPV-independent cervical intraepithelial neoplasia [CIN; differentiated CIN]) and molecular tumorigenetic pathway. Cases diagnosed within 7 years with a mean age of 75 (range: 69-83) years and a mean tumor size of 7.3 cm (range: 5.2-9.4 cm). All patients presented with locally advanced disease, and 1 woman died of the disease within 4, and another within 14 months of follow-up. All CSCCs and their adjacent precursor lesions were negative for p16, with aberrant p53-expression and diffuse and strong staining for cytokeratin 17. Both the CSCCs and their precursors were negative for HPV-DNA but harbored a TP53 mutation. The precursor lesions were characterized by epithelial thickening with superficial keratinization, and the presence of basal and parabasal keratinocytes with mitotic figures beyond the basal layer, thus showing features similar to those seen in differentiated types of vulvar intraepithelial lesions (vulvar intraepithelial neoplasia [VIN] syn. HPV-independent/p53abn VIN), suggesting the terminology of differentiated CIN or HPV-independent/p53abn CIN. An HPV-independent pathogenetic pathway with a p53-alteration was identified for these cases. CSCC associated with uterine prolapse represents HPV-independent tumors harboring a TP53 mutation. For the first time, a precursor lesion of HPV-independent CSCC of the uterine cervix is described with a differentiated VIN-like morphology, and a separate tumorigenic pathway defined.
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OBJECTIVES: Mutations in STK11 (STK11MUT) and KEAP1 (KEAP1MUT) occur frequently in non-small cell lung cancer (NSCLC) and are often co-mutated with KRAS. Several studies linked the co-occurrence of KRASMUT + STK11MUT, as well as KRASMUT + KEAP1MUT to reduced response to immune checkpoint inhibitors (ICI) and even a negative impact on survival. Data focusing STK11 + KEAP1 co-mutations or the triple mutation (KRAS + STK11 + KEAP1) are scarce. The recent availability of KRAS-G12C inhibitors increases the clinical relevance of those co-mutations in KRAS-mutated NSCLC. MATERIALS AND METHODS: We present a comprehensive bioinformatic analysis encompassing six datasets retrieved from cBioPortal. RESULTS: Independent of the treatment, triple mutations and STK11MUT + KEAP1MUT were significantly associated with a reduced overall survival (OS). Across treatments, OS of patients with a KRAS G12C triple mutation was significantly reduced compared to patients with KRAS G12C-only. Under ICI-therapy, there was no significant difference in OS between patients harboring the KRAS G12C-only and patients with the KRAS G12C triple mutation, but a significant difference between patients harboring KRAS non-G12C and KRAS non-G12C triple mutations. Triple mutated primary tumors showed a significantly increased frequency of distant metastases to bone and adrenal glands compared to KRAS-only mutated tumors. Additionally, our drug response analysis in cancer cell lines harboring the triple mutations revealed the WNT pathway inhibitor XAV-939 as a potential future drug candidate for this mutational situation. CONCLUSION: The triple mutation status may serve as a negative prognostic and predictive factor across treatments compared to KRASMUT-only. KRAS G12C generally seems to be a negative predictive marker for ICI-therapy.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Fator 2 Relacionado a NF-E2/genética , Mutação/genética , Biologia Computacional , Proteínas Serina-Treonina Quinases/genética , Quinases Proteína-Quinases Ativadas por AMPRESUMO
Telomerase reverse transcriptase (TERT) promoter mutations occur frequently in cancer, have been associated with increased TERT expression and cell proliferation, and could potentially influence therapeutic regimens for melanoma. As the role of TERT expression in malignant melanoma and the non-canonical functions of TERT remain understudied, we aimed to extend the current knowledge on the impact of TERT promoter mutations and expression alterations in tumor progression by analyzing several highly annotated melanoma cohorts. Using multivariate models, we found no consistent association for TERT promoter mutations or TERT expression with the survival rate in melanoma cohorts under immune checkpoint inhibition. However, the presence of CD4+ T cells increased with TERT expression and correlated with the expression of exhaustion markers. While the frequency of promoter mutations did not change with Breslow thickness, TERT expression was increased in metastases arising from thinner primaries. As single-cell RNA-sequencing (RNA-seq) showed that TERT expression was associated with genes involved in cell migration and dynamics of the extracellular matrix, this suggests a role of TERT during invasion and metastasis. Co-regulated genes found in several bulk tumors and single-cell RNA-seq cohorts also indicated non-canonical functions of TERT related to mitochondrial DNA stability and nuclear DNA repair. This pattern was also evident in glioblastoma and across other entities. Hence, our study adds to the role of TERT expression in cancer metastasis and potentially also immune resistance.
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Melanoma , Neoplasias Cutâneas , Telomerase , Humanos , Linfócitos T CD4-Positivos/patologia , Melanoma/genética , Melanoma/patologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Regiões Promotoras Genéticas , Mutação , Reparo do DNA/genética , Telomerase/genéticaRESUMO
Large genome-scale studies are deposited in various public sequence repositories. However, their access and analysis can be non-trivial to infrequent users. Here, we present a new database connecting whole transcriptomes with clinical data for straight-forward access and analysis of patient-specific samples. Users can perform association tests of survival and gene expression across different cohorts, identify cell-type expressions, or correlate the presence of immune cells. In summary, we present a new data hub for bench scientists to perform replication and discovery studies.
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Melanoma , Humanos , TranscriptomaRESUMO
PURPOSE: A wide therapeutic repertoire has become available to oncologists including radio- and chemotherapy, small molecules and monoclonal antibodies. However, drug efficacy can be limited by genetic heterogeneity. Here, we designed a webtool that facilitates the data analysis of the in vitro drug sensitivity data on 265 approved compounds from the GDSC database in association with a plethora of genetic changes documented for 1001 cell lines in the CCLE data. METHODS: The webtool computes odds ratios of drug resistance for a queried set of genetic alterations. It provides results on the efficacy of single compounds or groups of compounds assigned to cellular signaling pathways. Webtool availability: https://tools.hornlab.org/GDSC/ . RESULTS: We first replicated established associations of genetic driver mutations in BRAF, RAS genes and EGFR with drug response. We then tested the 'BRCAness' hypothesis and did not find increased sensitivity to the assayed PARP inhibitors. Analyzing specific PIK3CA mutations related to cancer and mendelian overgrowth, we found support for the described sensitivity of H1047 mutants to GSK690693 targeting the AKT pathway. Testing a co-mutated gene pair, GATA3 activation abolished PTEN-related sensitivity to PI3K/mTOR inhibition. Finally, the pharmacogenomic modifier ABCB1 was associated with olaparib resistance. CONCLUSIONS: This tool could identify potential drug candidates in the presence of custom sets of genetic changes and moreover, improve the understanding of signaling pathways. The underlying computer code can be adapted to larger drug response datasets to help structure and accommodate the increasingly large biomedical knowledge base.
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Neoplasias , Fosfatidilinositol 3-Quinases , Humanos , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/genética , Transdução de Sinais , Mutação , Linhagem Celular , Resistência a Medicamentos , Resistencia a Medicamentos Antineoplásicos/genética , Linhagem Celular TumoralRESUMO
The Bering Land Bridge (BLB) last connected Eurasia and North America during the Late Pleistocene. Although the BLB would have enabled transfers of terrestrial biota in both directions, it also acted as an ecological filter whose permeability varied considerably over time. Here we explore the possible impacts of this ecological corridor on genetic diversity within, and connectivity among, populations of a once wide-ranging group, the caballine horses (Equus spp.). Using a panel of 187 mitochondrial and eight nuclear genomes recovered from present-day and extinct caballine horses sampled across the Holarctic, we found that Eurasian horse populations initially diverged from those in North America, their ancestral continent, around 1.0-0.8 million years ago. Subsequent to this split our mitochondrial DNA analysis identified two bidirectional long-range dispersals across the BLB ~875-625 and ~200-50 thousand years ago, during the Middle and Late Pleistocene. Whole genome analysis indicated low levels of gene flow between North American and Eurasian horse populations, which probably occurred as a result of these inferred dispersals. Nonetheless, mitochondrial and nuclear diversity of caballine horse populations retained strong phylogeographical structuring. Our results suggest that barriers to gene flow, currently unidentified but possibly related to habitat distribution across Beringia or ongoing evolutionary divergence, played an important role in shaping the early genetic history of caballine horses, including the ancestors of living horses within Equus ferus.
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DNA Mitocondrial , Genoma , Animais , Evolução Biológica , DNA Mitocondrial/genética , Cavalos/genética , Filogenia , FilogeografiaRESUMO
PURPOSE: Genetic diagnostics of neurodevelopmental disorders with epilepsy (NDDE) are predominantly applied in children, thus limited information is available regarding adults or elderly. METHODS: We investigated 150 adult/elderly individuals with NDDE by conventional karyotyping, FMR1 testing, chromosomal microarray, panel sequencing, and for unresolved cases, also by exome sequencing (nsingle = 71, ntrios = 24). RESULTS: We identified (likely) pathogenic variants in 71 cases (47.3%) comprising fragile X syndrome (n = 1), disease-causing copy number (n = 23), and single-nucleotide variants (n = 49). Seven individuals displayed multiple independent genetic diagnoses. The diagnostic yield correlated with the severity of intellectual disability. Individuals with anecdotal evidence of exogenic early-life events (e.g., nuchal cord, complications at delivery) with alleged/unproven association to the disorder had a particularly high yield of 58.3%. Screening for disease-specific comorbidities was indicated in 45.1% and direct treatment consequences arose in 11.8% of diagnosed individuals. CONCLUSION: Panel/exome sequencing displayed the highest yield and should be considered as first-tier diagnostics in NDDE. This high yield and the numerous indications for additional screening or treatment modifications arising from genetic diagnoses indicate a current medical undersupply of genetically undiagnosed adult/elderly individuals with NDDE. Moreover, knowledge of the course of elderly individuals will ultimately help in counseling newly diagnosed individuals with NDDE.
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Epilepsia , Deficiência Intelectual , Transtornos do Neurodesenvolvimento , Adulto , Idoso , Epilepsia/diagnóstico , Epilepsia/genética , Proteína do X Frágil da Deficiência Intelectual/genética , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Cariotipagem , Sequenciamento do ExomaRESUMO
Pathogenic variants in TP53 have been classically thought to cause Li-Fraumeni syndrome (LFS), a cancer predisposition with high risks for various childhood- and adult-onset malignancies. However, increased genetic testing has lately revealed, that pathogenic variant carriers exhibit a broader range of phenotypes and that penetrance may be dependent both on variant type and modifiers. Using next generation sequencing and short tandem repeat analysis, we identified germline pathogenic variants in TP53 and RAD51C located in cis on chromosome 17 in a 43-year-old male, who has developed a rare sebaceous gland carcinoma (SGC) but so far no tumors of the LFS spectrum. This course mirrors a Trp53-Rad51c-double-mutant cis mouse-model, which similarly develops SGC, while the characteristic Trp53-associated tumor spectrum occurs with significantly lower frequency. Therefore, we propose that co-occurent pathogenic variants in RAD51C and TP53 may predispose to SGC, reminiscent of Muir-Torre syndrome. Further, this report supports the diversity of clinical presentations associated with germline TP53 alterations, and thus, the proposed expansion of LFS to heritable TP53-related cancer syndrome.
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Carcinoma/genética , Proteínas de Ligação a DNA/genética , Neoplasias das Glândulas Sebáceas/genética , Proteína Supressora de Tumor p53/genética , Adulto , Carcinoma/patologia , Predisposição Genética para Doença , Humanos , Masculino , Mutação , Fenótipo , Neoplasias das Glândulas Sebáceas/patologiaRESUMO
PURPOSE: Endometrial mesonephric-like adenocarcinoma (ML-AC) represents a recently recognized subtype of endometrial adenocarcinoma (AC) associated with a subtle immunophenotype with a characteristic KRAS-mutation. Detailed clinico-pathologic analyses and prognostic data on ML-AC are limited. METHODS: We report a series of four cases with histopathological, immunohistochemical, and molecular analyses. These cases as well as the data of previously published cases were reviewed for clinico-pathologic variables and clinical follow-up information. RESULTS: Forty cases of ML-AC were identified. ML-AC represents about 1% of all endometrial carcinomas. Similar to other types of endometrial AC, vaginal bleeding was the leading presenting symptom, and the mean age was 60.0 years (range 31-91). More than a half of the patients presented with locally advanced disease (≥ FIGO stage II) at time of diagnosis, developed a recurrence or died of the disease within a mean follow-up period of 24.7 months (range 3-144.5 months). The most common site of distant disease was pulmonary involvement. Microscopically, ML-ACs present with mixed morphology and show a co-expression of so-called mesonephric and Müllerian markers, suggesting a Müllerian origin of the tumors. Immunostaining for PD-L1 was negative in all tested cases, using different antibodies against PD-L1. Retained staining for mismatch repair proteins on immunohistochemistry and a POLE-mutation suggest a copy number low phenotype within the molecular classification of endometrial carcinomas. Almost all cases showed a KRAS-mutation at codon 12 (mostly G12V). CONCLUSION: Uterine ML-AC represents a distinct subtype of invasive endometrial AC, associated with KRAS-mutations and characteristic immunohistochemical findings. Clinically, ML-AC may show an aggressive behavior with a high rate of recurrent disease and a substantial risk for distant metastatic disease, especially to the lungs.
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Adenocarcinoma/diagnóstico , Neoplasias do Endométrio/diagnóstico , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Idoso , Carcinoma Endometrioide/diagnóstico , Carcinoma Endometrioide/genética , Carcinoma Endometrioide/metabolismo , Carcinoma Endometrioide/patologia , Diagnóstico Diferencial , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/patologia , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , PrognósticoRESUMO
Severe early onset epilepsies are often caused by de novo pathogenic variants. Few studies have reported the frequency of somatic mosaicism in parents of children with severe epileptic encephalopathies. Here we aim to investigate the frequency of mosaicism in the parents of children with epilepsy caused by alleged de novo variants. We tested parental genomic DNA derived from different tissues for 75 cases using targeted next-generation sequencing. Five parents (6.6%) showed mosaicism at minor allele frequencies of 0.8%-29% for the pathogenic variant detected in their offspring. Parental mosaicism was observed in the following genes: SCN1A, SCN2A, SCN8A, and STXBP1. One of the identified parents had epilepsy himself. Our results show that de novo events can occur already in parental tissue and in some cases can be detected in peripheral blood. Consequently, parents affected by low-grade mosaicism are faced with an increased recurrence risk for transmitting the pathogenic variant, compared to the overall recurrence risk for a second affected child estimated at approximately 1%. However, testing for parental somatic mosaicism will help identifying those parents who truly are at higher risk and will significantly improve genetic counseling in the respective families.
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Epilepsia/complicações , Epilepsia/genética , Mosaicismo , Adulto , Alelos , Criança , Pré-Escolar , DNA/genética , Feminino , Frequência do Gene , Variação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pais , Linhagem , Recidiva , Fatores de RiscoRESUMO
The extinct 'New World stilt-legged', or NWSL, equids constitute a perplexing group of Pleistocene horses endemic to North America. Their slender distal limb bones resemble those of Asiatic asses, such as the Persian onager. Previous palaeogenetic studies, however, have suggested a closer relationship to caballine horses than to Asiatic asses. Here, we report complete mitochondrial and partial nuclear genomes from NWSL equids from across their geographic range. Although multiple NWSL equid species have been named, our palaeogenomic and morphometric analyses support the idea that there was only a single species of middle to late Pleistocene NWSL equid, and demonstrate that it falls outside of crown group Equus. We therefore propose a new genus, Haringtonhippus, for the sole species H. francisci. Our combined genomic and phenomic approach to resolving the systematics of extinct megafauna will allow for an improved understanding of the full extent of the terminal Pleistocene extinction event.
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Fósseis , Cavalos/classificação , Animais , Biometria , DNA/química , DNA/genética , Genótipo , Cavalos/anatomia & histologia , Cavalos/genética , América do Norte , Fenótipo , Análise de Sequência de DNARESUMO
There is the tendency to assume that endangered species have been both genetically and demographically healthier in the past, so that any genetic erosion observed today was caused by their recent decline. The Iberian lynx (Lynx pardinus) suffered a dramatic and continuous decline during the 20th century, and now shows extremely low genome- and species-wide genetic diversity among other signs of genomic erosion. We analyze ancient (N = 10), historical (N = 245), and contemporary (N = 172) samples with microsatellite and mitogenome data to reconstruct the species' demography and investigate patterns of genetic variation across space and time. Iberian lynx populations transitioned from low but significantly higher genetic diversity than today and shallow geographical differentiation millennia ago, through a structured metapopulation with varying levels of diversity during the last centuries, to two extremely genetically depauperate and differentiated remnant populations by 2002. The historical subpopulations show varying extents of genetic drift in relation to their recent size and time in isolation, but these do not predict whether the populations persisted or went finally extinct. In conclusion, current genetic patterns were mainly shaped by genetic drift, supporting the current admixture of the two genetic pools and calling for a comprehensive genetic management of the ongoing conservation program. This study illustrates how a retrospective analysis of demographic and genetic patterns of endangered species can shed light onto their evolutionary history and this, in turn, can inform conservation actions.
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Lynx/genética , Análise de Sequência de DNA/métodos , Animais , Conservação dos Recursos Naturais , DNA Antigo/análise , Espécies em Perigo de Extinção , Extinção Biológica , Deriva Genética , Variação Genética/genética , Genoma , Genoma Mitocondrial/genética , Repetições de Microssatélites/genéticaRESUMO
The straight-tusked elephants Palaeoloxodon spp. were widespread across Eurasia during the Pleistocene. Phylogenetic reconstructions using morphological traits have grouped them with Asian elephants (Elephas maximus), and many paleontologists place Palaeoloxodon within Elephas. Here, we report the recovery of full mitochondrial genomes from four and partial nuclear genomes from two P. antiquus fossils. These fossils were collected at two sites in Germany, Neumark-Nord and Weimar-Ehringsdorf, and likely date to interglacial periods ~120 and ~244 thousand years ago, respectively. Unexpectedly, nuclear and mitochondrial DNA analyses suggest that P. antiquus was a close relative of extant African forest elephants (Loxodonta cyclotis). Species previously referred to Palaeoloxodon are thus most parsimoniously explained as having diverged from the lineage of Loxodonta, indicating that Loxodonta has not been constrained to Africa. Our results demonstrate that the current picture of elephant evolution is in need of substantial revision.
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Elefantes/genética , Evolução Molecular , Fósseis , Genômica , Animais , DNA Mitocondrial/genética , Genoma Mitocondrial , Filogenia , Análise de Sequência de DNARESUMO
The arrival of bison in North America marks one of the most successful large-mammal dispersals from Asia within the last million years, yet the timing and nature of this event remain poorly determined. Here, we used a combined paleontological and paleogenomic approach to provide a robust timeline for the entry and subsequent evolution of bison within North America. We characterized two fossil-rich localities in Canada's Yukon and identified the oldest well-constrained bison fossil in North America, a 130,000-y-old steppe bison, Bison cf. priscus We extracted and sequenced mitochondrial genomes from both this bison and from the remains of a recently discovered, â¼120,000-y-old giant long-horned bison, Bison latifrons, from Snowmass, Colorado. We analyzed these and 44 other bison mitogenomes with ages that span the Late Pleistocene, and identified two waves of bison dispersal into North America from Asia, the earliest of which occurred â¼195-135 thousand y ago and preceded the morphological diversification of North American bison, and the second of which occurred during the Late Pleistocene, â¼45-21 thousand y ago. This chronological arc establishes that bison first entered North America during the sea level lowstand accompanying marine isotope stage 6, rejecting earlier records of bison in North America. After their invasion, bison rapidly colonized North America during the last interglaciation, spreading from Alaska through continental North America; they have been continuously resident since then.
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Bison/genética , Animais , Bison/classificação , Bison/fisiologia , DNA Mitocondrial/genética , Fósseis/história , Genoma Mitocondrial , Genômica , História Antiga , América do Norte , FilogeniaRESUMO
BACKGROUND: Recent advances in sequencing technologies supported the development of molecularly targeted therapy in cancer patients. Thus, genomic analyses are becoming a routine part in clinical practice and accurate detection of actionable mutations is essential to assist diagnosis and therapy choice. However, this is often challenging due to major problems associated with DNA from formalin-fixed paraffin-embedded tissue which is usually the primary source for genetic testing. OBJECTIVES: Here we want to share our experience regarding major problems associated with FFPE DNA used for PCR-based sequencing as illustrated by the mutational analysis of ERBB4 in melanoma. We want to focus on two major problems including extensive DNA fragmentation and hydrolytic deamination as source of non-reproducible sequence artifacts. Further, we provide potential explanations and possible strategies to minimize these difficulties and improve the detection of targetable mutations. METHODS: Genomic DNA from formalin-fixed paraffin-embedded tumor samples was isolated followed by PCR amplification, Sanger sequencing and statistical analysis. RESULTS: Analysis of Sanger sequencing data revealed a total of 46 ERBB4 mutations in 27 of 96 samples including the identification of 11 mutations at three previously unknown mutational hotspots. Unfortunately, we were not able to confirm any assumed hotspot mutation within repeated sequencing of relevant amplicons suggesting the detection of sequence artifacts most likely caused by DNA lesions associated with FFPE tissues. CONCLUSION: Since DNA from FFPE tissue is usually the primary source for mutational analyses, appropriate measures must be implemented in the workflow to assess DNA damage in formalin-fixed tissue to ensure accurate detection of actionable mutations and minimize the occurrence of sequence artifacts.
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Artefatos , Análise Mutacional de DNA/métodos , Inclusão em Parafina , Receptor ErbB-4/genética , Fixação de Tecidos , Sequência de Bases , DNA/análise , Formaldeído , Humanos , Melanoma/genética , Reação em Cadeia da Polimerase/métodos , Receptor ErbB-4/análiseRESUMO
DNA derived from formalin-fixed and paraffin-embedded (FFPE) tissue has been a challenge to large-scale genomic sequencing, due to its low quality and quantities. Improved techniques enabling the genome-wide analysis of FFPE material would be of great value, both from a research and clinical perspective.Comparing a single-strand DNA library preparation method originally developed for ancient DNA to conventional protocols using double-stranded DNA derived from FFPE material we obtain on average 900-fold more library molecules and improved sequence complexity from as little as 5 ng input DNA. FFPE DNA is highly fragmented, usually below 100bp, and up to 60% of reads start after or end prior to adenine residues, suggesting that crosslinks predominate at adenine residues. Similar to ancient DNA, C > T substitutions are slightly increased with maximum rates up to 3% at the ends of molecules. In whole exome sequencing of single-strand libraries from lung, breast, colorectal, prostate and skin cancers we identify known cancer mutations. In summary, we show that single-strand library preparation enables genomic sequencing, even from low amounts of degraded FFPE DNA. This method provides a clear advantage both in research and clinical settings, where FFPE material (e.g. from biopsies) often is the only source of DNA available. Improving the genetic characterization that can be performed on conventional archived FFPE tissue, the single-strand library preparation allows scarce samples to be used in personalized medicine and enables larger sample sizes in future sequencing studies.
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DNA de Cadeia Simples/análise , Biblioteca Gênica , Neoplasias/diagnóstico , Animais , Formaldeído/química , Genoma , Humanos , Neoplasias/genética , Inclusão em Parafina , Análise de Sequência de DNA , Fixação de TecidosRESUMO
Melanoma often recurs after a latency period of several years, presenting a T cell-edited phenotype that reflects a role for CD8(+) T cells in maintaining metastatic latency. Here, we report an investigation of a patient with multiple recurrent lesions, where poorly immunogenic melanoma phenotypes were found to evolve in the presence of autologous tumor antigen-specific CD8(+) T cells. Melanoma cells from two of three late recurrent metastases, developing within a 6-year latency period, lacked HLA class I expression. CD8(+) T cell-resistant, HLA class I-negative tumor cells became clinically apparent 1.5 and 6 years into stage IV disease. Genome profiling by SNP arrays revealed that HLA class I loss in both metastases originated from a shared chromosome 15q alteration and independently acquired focal B2M gene deletions. A third HLA class I haplotype-deficient lesion developed in year 3 of stage IV disease that acquired resistance toward dominant CD8(+) T-cell clonotypes targeting stage III tumor cells. At an early stage, melanoma cells showed a dedifferentiated c-Jun(high)/MITF(low) phenotype, possibly associated with immunosuppression, which contrasted with a c-Jun(low)/MITF(high) phenotype of T cell-edited tumor cells derived from late metastases. In summary, our work shows how tumor recurrences after long-term latency evolve toward T-cell resistance by independent genetic events, as a means for immune escape and immunotherapeutic resistance. Cancer Res; 76(15); 4347-58. ©2016 AACR.
Assuntos
Antígenos de Neoplasias/imunologia , Linfócitos T CD8-Positivos/imunologia , Melanoma/genética , Proteínas de Neoplasias/imunologia , Humanos , Melanoma/patologia , Metástase NeoplásicaRESUMO
The Ice Free Corridor has been invoked as a route for Pleistocene human and animal dispersals between eastern Beringia and more southerly areas of North America. Despite the significance of the corridor, there are limited data for when and how this corridor was used. Hypothetical uses of the corridor include: the first expansion of humans from Beringia into the Americas, northward postglacial expansions of fluted point technologies into Beringia, and continued use of the corridor as a contact route between the north and south. Here, we use radiocarbon dates and ancient mitochondrial DNA from late Pleistocene bison fossils to determine the chronology for when the corridor was open and viable for biotic dispersals. The corridor was closed after â¼23,000 until 13,400 calendar years ago (cal y BP), after which we find the first evidence, to our knowledge, that bison used this route to disperse from the south, and by 13,000 y from the north. Our chronology supports a habitable and traversable corridor by at least 13,000 cal y BP, just before the first appearance of Clovis technology in interior North America, and indicates that the corridor would not have been available for significantly earlier southward human dispersal. Following the opening of the corridor, multiple dispersals of human groups between Beringia and interior North America may have continued throughout the latest Pleistocene and early Holocene. Our results highlight the utility of phylogeographic analyses to test hypotheses about paleoecological history and the viability of dispersal routes over time.
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Bison/genética , Animais , Canadá , DNA Mitocondrial/genética , Fósseis , FilogeografiaAssuntos
Melanoma/diagnóstico , Neoplasias Meníngeas/diagnóstico , Mutação , Idoso , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Humanos , Masculino , Melanoma/genética , Melanoma/patologia , Neoplasias Meníngeas/genética , Neoplasias Meníngeas/patologia , Proteínas Supressoras de Tumor/genética , Ubiquitina Tiolesterase/genéticaRESUMO
Melanocytic tumors originating in the central nervous system (MT-CNS) are rare tumors that generally have a favorable prognosis, however malignant tumors do occur. Pathogenetically MT-CNS are not well characterized. Similar to uveal melanoma and blue nevi, they frequently harbor activating GNAQ or GNA11 mutations. Rare NRAS mutations have also been reported. Other mutations have not yet been described. We analyzed 19 MT-CNS, 7 uveal melanomas and 19 cutaneous melanomas using a targeted next generation sequencing approach analyzing 29 genes known to be frequently mutated in other melanocytic tumors (in particular uveal and cutaneous melanomas). In concordance with previous studies, cutaneous melanoma samples showed frequent NRAS or BRAF mutations, as well as mutations in other genes (e.g. NF1, RAC1, PIK3CA, ARID1A). Metastasized uveal melanomas exhibited mutations in GNAQ, GNA11 and BAP1. In contrast, MT-CNS almost exclusively demonstrated mutations in GNAQ (71 %) or GNA11 (12 %). Interestingly both GNA11 mutations identified were detected in MT-CNS diagnosed as intermediate grade melanocytomas which also recurred. One of these recurrent cases also harbored an inactivating BAP1 mutation and was found to have lost one copy of chromosome 3. Our findings show that while MT-CNS do have GNAQ or GNA11 mutations, they rarely harbor other recurrent mutations found in uveal or cutaneous melanomas. Considering chromosome 3 and BAP1 loss are robust markers of poor prognosis in uveal melanoma, it will prove interesting to determine whether these genomic alterations are also of prognostic significance in MT-CNS.