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1.
Oncogene ; 39(39): 6172-6189, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32820253

RESUMO

Androgen receptor (AR), is a transcription factor and a member of a hormone receptor superfamily. AR plays a vital role in the progression of prostate cancer and is a crucial target for therapeutic interventions. While the majority of advanced-stage prostate cancer patients will initially respond to the androgen deprivation, the disease often progresses to castrate-resistant prostate cancer (CRPC). Interestingly, CRPC tumors continue to depend on hyperactive AR signaling and will respond to potent second-line antiandrogen therapies, including bicalutamide (CASODEX®) and enzalutamide (XTANDI®). However, the progression-free survival rate for the CRPC patients on antiandrogen therapies is only 8-19 months. Hence, there is a need to understand the mechanisms underlying CRPC progression and eventual treatment resistance. Here, we have leveraged next-generation sequencing and newly developed analytical methodologies to evaluate the role of AR signaling in regulating the transcriptome of prostate cancer cells. The genomic and pharmacologic stimulation and inhibition of AR activity demonstrates that AR regulates alternative splicing within cancer-relevant genes. Furthermore, by integrating transcriptomic data from in vitro experiments and in prostate cancer patients, we found that a significant number of AR-regulated splicing events are associated with tumor progression. For example, we found evidence for an inadvertent AR-antagonist-mediated switch in IDH1 and PL2G2A isoform expression, which is associated with a decrease in overall survival of patients. Mechanistically, we discovered that the epithelial-specific splicing regulators (ESRP1 and ESRP2), flank many AR-regulated alternatively spliced exons. And, using 2D invasion assays, we show that the inhibition of ESRPs can suppress AR-antagonist-driven tumor invasion. Our work provides evidence for a new mechanism by which AR alters the transcriptome of prostate cancer cells by modulating alternative splicing. As such, our work has important implications for CRPC progression and development of resistance to treatment with bicalutamide and enzalutamide.

2.
Cancer Res ; 80(18): 3803-3809, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32631904

RESUMO

Human papillomavirus (HPV) 16 displays substantial sequence variation; four HPV16 lineages (A, B, C, and D) have been described as well as multiple sublineages. To identify molecular events associated with HPV16 carcinogenesis, we evaluated viral variation, the integration of HPV16, and somatic mutation in 96 cervical cancer samples from Guatemala. A total of 65% (62/96) of the samples had integrated HPV16 sequences and integration was associated with an earlier age of diagnosis and premenopausal disease. HPV16 integration sites were broadly distributed in the genome, but in one tumor, HPV16 integrated into the promoter of the IFN regulatory factor 4 (IRF4) gene, which plays an important role in the regulation of the IFN response to viral infection. The HPV16 D2 and D3 sublineages were found in 23% and 30% of the tumors, respectively, and were significantly associated with adenocarcinoma. D2-positive tumors had a higher rate of integration, earlier age of diagnosis, and a lower rate of somatic mutation, whereas D3-positive tumors were less likely to integrate, had later age of diagnosis, and exhibited a higher rate of somatic mutation. In conclusion, Guatemalan cervical tumors have a high frequency of very high-risk HPV16 D2 and D3 sublineages harboring distinct histology, which may help guide future therapeutic strategies to target the tumor and reduce recurrence. SIGNIFICANCE: This study details the biological and molecular properties of the most pathogenic forms of HPV16, the cause of the majority of cervical cancers.

4.
Prostate Cancer Prostatic Dis ; 22(3): 406-410, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30542053

RESUMO

BACKGROUND: Germline mutations in BRCA2 have been linked to a higher risk of prostate cancer (PCa), and high frequency of BRCA1 and BRCA2 (BRCA1/2) gene alterations was recently reported in metastatic castration-resistant PCa specimens. Mutations in BRCA2 vary in racial and ethnic groups including African-American (AA) and Caucasian-American (CA) populations. METHODS: BRCA1 and BRCA2 genes were sequenced (Ion AmpliSeq targeted sequencing) in archived blood DNA specimens in 1240 PCa patients, including 30% AA patients, in three different cohorts: localized early stage (T2) PCa (N = 935); advanced PCa (50% T3-4) (N = 189); and metastatic PCa (N = 116). The sequences were analyzed for known and novel mutations in BRCA1/2. Statistical analyses were performed to determine associations of the mutations with clinico-pathological parameters. RESULTS: BRCA2 mutations with known pathogenic annotation were significantly more prevalent in men with advanced and metastatic PCa (3.1%) compared to patients with an organ-confined disease (0.7%). AA patients carried more frequently BRCA1/2 variants of unknown significance (VUS) when compared to Caucasian Americans (4.6 vs. 1.6%, respectively). Significantly, pathogenic BRCA2 mutations in men with localized early stage PCa increased the risk of distant metastasis. CONCLUSIONS: Germline variants of unknown significance in BRCA1/2 are more frequent in AA than CA PCa patients; however, the prevalence of pathogenic mutations were similar across the races. Patients carrying BRCA2 pathogenic mutations are more likely to progress to metastasis.


Assuntos
Proteína BRCA2/genética , Recidiva Local de Neoplasia/genética , Prostatectomia , Neoplasias da Próstata/genética , Adulto , Afro-Americanos/genética , Proteína BRCA1/genética , Estudos de Casos e Controles , Análise Mutacional de DNA , Progressão da Doença , Grupo com Ancestrais do Continente Europeu/genética , Seguimentos , Mutação em Linhagem Germinativa , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Próstata/patologia , Próstata/cirurgia , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , Fatores de Tempo
5.
Cancers (Basel) ; 10(11)2018 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-30400234

RESUMO

Breast cancer is the most common cause of cancer diagnosis in women and is responsible for considerable mortality among the women of Puerto Rico. However, there are few studies in Puerto Rico on the genetic factors influencing risk. To determine the contribution of pathogenic mutations in BRCA1 and BRCA2, we sequenced these genes in 302 cases from two separate medical centers, who were not selected for age of onset or family history. We identified nine cases that are carriers of pathogenic germline mutation. This represents 2.9% of unselected cases and 5.6% of women meeting National Comprehensive Cancer Network (NCCN) criteria for BRCA testing. All of the identified pathogenic mutations were in the BRCA2 gene and the most common mutation is the p.Glu1308Ter (E1308X) mutation in BRCA2 found in eight out of nine cases, representing 89% of the pathogenic carriers. The E1308X mutation has been identified in breast and ovarian cancer families in Spain, and analysis of flanking DNA polymorphisms shows that all E1308X carriers occur on the same haplotype. This is consistent with BRCA2 E1308X being a founder mutation for the Puerto Rican population. These results will contribute to better inform genetic screening and counseling of breast and ovarian cancer cases in Puerto Rico and Puerto Rican populations in mainland United States.

6.
BMC Cancer ; 18(1): 562, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29764400

RESUMO

BACKGROUND: A low cost and accurate method for detecting high-risk (HR) human papillomavirus (HPV) is important to permit HPV testing for cervical cancer prevention. We used a commercially available HPV method (H13, Hybribio) which was documented to function accurately in a reduced volume of cervical specimen to determine the most prevalent HPV types and the distribution of HPV infections in over 1795 cancer-free women in Guatemala undergoing primary screening for cervical cancer by cytology. METHODS: HR-HPV detection was attempted in cervical samples from 1795 cancer-free women receiving Pap smears using the Hybribio™ real-time PCR assay of 13 HR types. The test includes a globin gene internal control. HPV positive samples were sequenced to determine viral type. Age-specific prevalence of HPV was also assessed in the study population. RESULTS: A total of 13% (226/1717) of women tested HPV+, with 78 samples (4.3%) failing to amplify the internal control. The highest prevalence was found in younger women (< 30 years, 22%) and older ones (≥60 years, 15%). The six most common HR-HPV types among the 148 HPV+ typed were HPV16 (22%), HPV18 (11%), HPV39 (11%), HPV58 (10%), HPV52 (8%), and HPV45 (8%). CONCLUSIONS: In this sample of cancer free women in Guatemala, HPV16 was the most prevalent HR type in Guatemala and the age-specific prevalence curve peaked in younger ages. Women in the 30-59-year age groups had a prevalence of HR-HPV of 8%, however, larger studies to better describe the epidemiology of HPV in Guatemala are needed.


Assuntos
Infecções Assintomáticas/epidemiologia , Detecção Precoce de Câncer/economia , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/diagnóstico , Neoplasias do Colo do Útero/prevenção & controle , Adolescente , Adulto , Fatores Etários , Idoso , Neoplasia Intraepitelial Cervical , Colo do Útero/virologia , Detecção Precoce de Câncer/métodos , Feminino , Genótipo , Guatemala/epidemiologia , Humanos , Programas de Rastreamento , Pessoa de Meia-Idade , Papillomaviridae/genética , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/virologia , Prevalência , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal , Adulto Jovem
7.
Breast Cancer Res Treat ; 165(3): 687-697, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28664506

RESUMO

PURPOSE: To characterize the spectrum of germline mutations in BRCA1, BRCA2, and PALB2 in population-based unselected breast cancer cases in an Asian population. METHODS: Germline DNA from 467 breast cancer patients in Sarawak General Hospital, Malaysia, where 93% of the breast cancer patients in Sarawak are treated, was sequenced for the entire coding region of BRCA1; BRCA2; PALB2; Exons 6, 7, and 8 of TP53; and Exons 7 and 8 of PTEN. Pathogenic variants included known pathogenic variants in ClinVar, loss of function variants, and variants that disrupt splice site. RESULTS: We found 27 pathogenic variants (11 BRCA1, 10 BRCA2, 4 PALB2, and 2 TP53) in 34 patients, which gave a prevalence of germline mutations of 2.8, 3.23, and 0.86% for BRCA1, BRCA2, and PALB2, respectively. Compared to mutation non-carriers, BRCA1 mutation carriers were more likely to have an earlier age at onset, triple-negative subtype, and lower body mass index, whereas BRCA2 mutation carriers were more likely to have a positive family history. Mutation carrier cases had worse survival compared to non-carriers; however, the association was mostly driven by stage and tumor subtype. We also identified 19 variants of unknown significance, and some of them were predicted to alter splicing or transcription factor binding sites. CONCLUSION: Our data provide insight into the genetics of breast cancer in this understudied group and suggest the need for modifying genetic testing guidelines for this population with a much younger age at diagnosis and more limited resources compared with Caucasian populations.


Assuntos
Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Genes BRCA1 , Genes BRCA2 , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Biomarcadores Tumorais , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/terapia , Análise Mutacional de DNA , Feminino , Humanos , Malásia/epidemiologia , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Vigilância da População , Gravidez , Prevalência , Fatores de Risco , Adulto Jovem
8.
Gigascience ; 4: 50, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26543556

RESUMO

BACKGROUND: Germline mutations in the BRCA1 and BRCA2 genes account for 20-25 % of inherited breast cancers and about 10 % of all breast cancer cases. Detection of BRCA mutation carriers can lead to therapeutic interventions such as mastectomy, oophorectomy, hormonal prevention therapy, improved screening, and targeted therapies such as PARP-inhibition. We estimate that African Americans and Hispanics are 4-5 times less likely to receive BRCA screening, despite having similar mutation frequencies as non-Jewish Caucasians, who have higher breast cancer mortality. To begin addressing this health disparity, we initiated a nationwide trial of BRCA testing of Latin American women with breast cancer. Patients were recruited through community organizations, clinics, public events, and by mail and Internet. Subjects completed the consent process and questionnaire, and provided a saliva sample by mail or in person. DNA from 120 subjects was used to sequence the entirety of BRCA1 and BRCA2 coding regions and splice sites, and validate pathogenic mutations, with a total material cost of $85/subject. Subjects ranged in age from 23 to 81 years (mean age, 51 years), 6 % had bilateral disease, 57 % were ER/PR+, 23 % HER2+, and 17 % had triple-negative disease. RESULTS: A total of seven different predicted deleterious mutations were identified, one newly described and the rest rare. In addition, four variants of unknown effect were found. CONCLUSIONS: Application of this strategy on a larger scale could lead to improved cancer care of minority and underserved populations.


Assuntos
Neoplasias da Mama/genética , Genes BRCA1 , Genes BRCA2 , Hispano-Americanos/genética , Feminino , Humanos
9.
Clin Cancer Res ; 21(23): 5360-70, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26080840

RESUMO

PURPOSE: Cervical cancer is one of the most common causes of cancer mortality for women living in poverty, causing more than 28,000 deaths annually in Latin America and 266,000 worldwide. To better understand the molecular basis of the disease, we ascertained blood and tumor samples from Guatemala and Venezuela and performed genomic characterization. EXPERIMENTAL DESIGN: We performed human papillomavirus (HPV) typing and identified somatically mutated genes using exome and ultra-deep targeted sequencing with confirmation in samples from Mexico. Copy number changes were also assessed in the exome sequence. RESULTS: Cervical cancer cases in Guatemala and Venezuela have an average age of diagnosis of 50 years and 5.6 children. Analysis of 675 tumors revealed activation of PIK3CA and other PI3K/AKT pathway genes in 31% of squamous carcinomas and 24% of adeno- and adenosquamous tumors, predominantly at two sites (E542K, E545K) in the helical domain of the PIK3CA gene. This distribution of PIK3CA mutations is distinct from most other cancer types and does not result in the in vitro phosphorylation of AKT. Somatic mutations were more frequent in squamous carcinomas diagnosed after the age of 50 years. Frequent gain of chromosome 3q was found, and low PIK3CA mutation fractions in many tumors suggest that PI3K mutation can be a late event in tumor progression. CONCLUSIONS: PI3K pathway mutation is important to cervical carcinogenesis in Latin America. Therapeutic agents that directly target PI3K could play a role in the therapy of this common malignancy.


Assuntos
Genoma Humano , Genômica , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/etiologia , Adulto , Idoso , Alphapapillomavirus/classificação , Alphapapillomavirus/genética , Biomarcadores Tumorais , Mapeamento Cromossômico , Classe I de Fosfatidilinositol 3-Quinases , Variações do Número de Cópias de DNA , Exoma , Feminino , Expressão Gênica , Guatemala/epidemiologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , México/epidemiologia , Pessoa de Meia-Idade , Mutação , Gradação de Tumores , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/virologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fatores de Risco , Transdução de Sinais , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , Venezuela/epidemiologia
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