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1.
Cancer Res ; 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33051252

RESUMO

DNA methylation contributes to malignant transformation, but little is known about how the methylation drives colorectal cancer evolution at the early stages. Here we identify aberrant INA (α-internexin) gene methylation in colon adenoma and adenocarcinoma by filtering data obtained from a genome-wide screen of methylated genes. The gene encoding INA, a type IV intermediate filament, was frequently hypermethylated in CpG islands located in the promoter region. This hypermethylation preferentially occurred in large tumors and was a prognostic marker for poor overall survival in colorectal cancer patients. This type of epigenetic alteration silenced INA expression in both adenoma and adenocarcinoma tissues. Gene silencing of INA in colorectal cancer cells increased cell proliferation, migration, and invasion. Restored INA expression blocked migration and invasion in vitro and reduced lung metastasis in vivo. Mechanistically, INA directly inhibited microtubule polymerization in vitro and decreased intracellular microtubule plus-end assembly rates. A peptide array screen surveying the tubulin-binding sites in INA identified a tubulin-binding motif located in the N-terminal head domain that plays a tumor-suppressive role by binding to unpolymerized tubulins and impeding microtubule polymerization. Thus, epigenetic inactivation of INA is an intermediate filament reorganization event that is essential to accelerate microtubule polymerization in the early stages of colorectal cancer.

2.
N Engl J Med ; 383(11): 1028-1039, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32905675

RESUMO

BACKGROUND: The efficacy and safety of combination therapy with eflornithine and sulindac, as compared with either drug alone, in delaying disease progression in patients with familial adenomatous polyposis are unknown. METHODS: We evaluated the efficacy and safety of the combination of eflornithine and sulindac, as compared with either drug alone, in adults with familial adenomatous polyposis. The patients were stratified on the basis of anatomical site with the highest polyp burden and surgical status; the strata were precolectomy (shortest projected time to disease progression), rectal or ileal pouch polyposis after colectomy (longest projected time), and duodenal polyposis (intermediate projected time). The patients were then randomly assigned in a 1:1:1 ratio to receive 750 mg of eflornithine, 150 mg of sulindac, or both once daily for up to 48 months. The primary end point, assessed in a time-to-event analysis, was disease progression, defined as a composite of major surgery, endoscopic excision of advanced adenomas, diagnosis of high-grade dysplasia in the rectum or pouch, or progression of duodenal disease. RESULTS: A total of 171 patients underwent randomization. Disease progression occurred in 18 of 56 patients (32%) in the eflornithine-sulindac group, 22 of 58 (38%) in the sulindac group, and 23 of 57 (40%) in the eflornithine group, with a hazard ratio of 0.71 (95% confidence interval [CI], 0.39 to 1.32) for eflornithine-sulindac as compared with sulindac (P = 0.29) and 0.66 (95% CI, 0.36 to 1.24) for eflornithine-sulindac as compared with eflornithine. Among 37 precolectomy patients, the corresponding values in the treatment groups were 2 of 12 patients (17%), 6 of 13 (46%), and 5 of 12 (42%) (hazard ratios, 0.30 [95% CI, 0.07 to 1.32] and 0.20 [95% CI, 0.03 to 1.32]); among 34 patients with rectal or ileal pouch polyposis, the values were 4 of 11 patients (36%), 2 of 11 (18%), and 5 of 12 (42%) (hazard ratios, 2.03 [95% CI, 0.43 to 9.62] and 0.84 [95% CI, 0.24 to 2.90]); and among 100 patients with duodenal polyposis, the values were 12 of 33 patients (36%), 14 of 34 (41%), and 13 of 33 (39%) (hazard ratios, 0.73 [95% CI, 0.34 to 1.52] and 0.76 [95% CI, 0.35 to 1.64]). Adverse and serious adverse events were similar across the treatment groups. CONCLUSIONS: In this trial involving patients with familial adenomatous polyposis, the incidence of disease progression was not significantly lower with the combination of eflornithine and sulindac than with either drug alone. (Funded by Cancer Prevention Pharmaceuticals; ClinicalTrials.gov number, NCT01483144; EudraCT number, 2012-000427-41.).


Assuntos
Polipose Adenomatosa do Colo/tratamento farmacológico , Progressão da Doença , Eflornitina/uso terapêutico , Sulindaco/uso terapêutico , Adulto , Quimioterapia Combinada , Eflornitina/efeitos adversos , Feminino , Humanos , Análise de Intenção de Tratamento , Estimativa de Kaplan-Meier , Masculino , Sulindaco/efeitos adversos , Resultado do Tratamento
4.
Nutrients ; 12(5)2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32353960

RESUMO

BACKGROUND: Obesity, defined by body mass index (BMI), measured at colorectal cancer (CRC) diagnosis has been associated with postoperative complications and survival outcomes. However, BMI does not allow for a differentiation between fat and muscle mass. Computed tomography (CT)-defined body composition more accurately reflects different types of tissue and their associations with health-related quality of life (HRQoL) during the first year of disease, but this has not been investigated yet. We studied the role of visceral and subcutaneous fat area (VFA and SFA) and skeletal muscle mass (SMM) on longitudinally assessed HRQoL in CRC patients. METHODS: A total of 138 newly diagnosed CRC patients underwent CT scans at diagnosis and completed questionnaires prior to and six and twelve months post-surgery. We investigated the associations of VFA, SFA, and SMM with HRQoL at multiple time points. RESULTS: A higher VFA was associated with increased pain six and twelve months post-surgery (ß = 0.06, p = 0.04 and ß = 0.07, p = 0.01) and with worse social functioning six months post-surgery (ß = -0.08, p = 0.01). Higher SMM was associated with increased pain twelve months post-surgery (ß = 1.03, p < 0.01). CONCLUSIONS: CT-quantified body composition is associated with HRQoL scales post-surgery. Intervention strategies targeting a reduction in VFA and maintaining SMM might improve HRQoL in CRC patients during the first year post-surgery.

5.
Artigo em Inglês | MEDLINE | ID: mdl-32299850

RESUMO

Early detection by screening significantly reduces mortality from colorectal cancer, but 40% of guideline-eligible patients are not screened as recommended in the US. Novel strategies to improve screening uptake overall, and efforts to deploy best-practices to underserved populations is a high priority for healthcare. This review focuses on existing biomarkers in practice and those in development with clinical relevance to early detection of colorectal neoplasia, with an emphasis on those developed by investigators of the National Cancer Institute's Early Detection Research Network (EDRN). Aberrantly methylated DNA markers (blood and stool), stool-based markers (including FIT-DNA), and a variety of blood-based markers assays in development (protein markers, glycoproteins including mucins, cell-free DNA tests) are reviewed. Individual markers and biomarker panels, sample resources, and barriers to translating biomarkers to clinical practice are discussed.

6.
J Cancer Surviv ; 14(3): 305-315, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32166576

RESUMO

PURPOSES: Cancer-related distress is known to persist long after completion of treatment. Factors related to distress are largely unexplored in colorectal cancer (CRC) survivors. We examined changes over time and risk factors for distress in CRC patients over the first year after surgery. METHODS: We included 212 CRC patients with data at 6 and 12 months post-surgery from the ColoCare Study in Heidelberg, Germany. Sociodemographic and lifestyle factors, social support, and health-related quality of life (HrQOL) prior to surgery were evaluated as predictors of cancer-related distress. Distress was measured with the Cancer and Treatment Distress instrument (CTXD). Linear regression analyses examined associations between risk factors and distress. RESULTS: Distress subscale scores varied significantly over time: health burden subscale score increased (P < .001), while finances (P = .004), medical demands (P < .001), and identity (P < .001) subscale scores decreased over time. Uncertainty and family strain subscale scores did not change. Younger age, lower income, advanced tumor stage, poorer social support, and poorer baseline HrQOL predicted higher level distress at 6 and 12 months. CONCLUSION: Cancer-related distress continues unresolved after surgery. Although some risk factors are difficult to alter, those at highest risk can be identified earlier for possible preventive strategies. IMPLICATIONS FOR CANCER SURVIVORS: Screening for risk factors pre-surgery would allow for targeted interventions including strategies to improve resources for those with low support, thereby reducing long-term distress in CRC survivors.

7.
Comp Med ; 70(2): 120-130, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32014085

RESUMO

Both human epidemiologic data and animal studies suggest that low serum vitamin D increases the risk of inflammatory bowel disease (IBD) and consequently IBD-associated colorectal cancer. We tested the hypothesis that vitamin D deficiency increases the risk for colitis-associated colon cancer (CAC) by using an established CAC mouse model, 129-Smad3tm1Par/J (Smad3-/-) mice, which have defective transforming growth factor ß-signaling and develop colitis and CAC after the administration of dextran sodium sulfate (DSS). After determining a dietary regimen that induced chronic vitamin D deficiency in Smad3-/- mice, we assessed the effects of vitamin D deficiency on CAC. Decreasing dietary vitamin D from 1 IU/g diet (control diet) to 0.2 IU /g diet did not decrease serum 25-hydroxyvitamin D (25(OH)D) levels in Smad3-/- mice. A diet devoid of vitamin D (< 0.02 IU/g diet [no added vitamin D]; vitamin D-null) significantly decreased serum 25(OH)D levels in mice after 2 wk (null compared with control diet: 8.4 mg/mL compared with 12.2 ng/mL) and further decreased serum levels to below the detection limit after 9 wk but did not affect weight gain, serum calcium levels, bone histology, or bone mineral density. In light of these results, Smad3-/- mice were fed a vitamin D-null diet and given DSS to induce colitis. Unexpectedly, DSS-treated Smad3-/- mice fed a vitamin D-null diet had improved survival, decreased colon tumor incidence (8% compared with 36%), and reduced the incidence and severity of colonic dysplasia compared with mice fed the control diet. These effects correlated with increased epithelial cell proliferation and repair early in the disease, perhaps reducing the likelihood of developing chronic colitis and progression to cancer. Our results indicate that vitamin D deficiency is beneficial in some cases of CAC, possibly by promoting intestinal healing.

8.
Clin Epigenetics ; 12(1): 5, 2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900199

RESUMO

BACKGROUND: Chronological age is a prominent risk factor for many types of cancers including colorectal cancer (CRC). Yet, the risk of CRC varies substantially between individuals, even within the same age group, which may reflect heterogeneity in biological tissue aging between people. Epigenetic clocks based on DNA methylation are a useful measure of the biological aging process with the potential to serve as a biomarker of an individual's susceptibility to age-related diseases such as CRC. METHODS: We conducted a genome-wide DNA methylation study on samples of normal colon mucosa (N = 334). Subjects were assigned to three cancer risk groups (low, medium, and high) based on their personal adenoma or cancer history. Using previously established epigenetic clocks (Hannum, Horvath, PhenoAge, and EpiTOC), we estimated the biological age of each sample and assessed for epigenetic age acceleration in the samples by regressing the estimated biological age on the individual's chronological age. We compared the epigenetic age acceleration between different risk groups using a multivariate linear regression model with the adjustment for gender and cell-type fractions for each epigenetic clock. An epigenome-wide association study (EWAS) was performed to identify differential methylation changes associated with CRC risk. RESULTS: Each epigenetic clock was significantly correlated with the chronological age of the subjects, and the Horvath clock exhibited the strongest correlation in all risk groups (r > 0.8, p < 1 × 10-30). The PhenoAge clock (p = 0.0012) revealed epigenetic age deceleration in the high-risk group compared to the low-risk group. CONCLUSIONS: Among the four DNA methylation-based measures of biological age, the Horvath clock is the most accurate for estimating the chronological age of individuals. Individuals with a high risk for CRC have epigenetic age deceleration in their normal colons measured by the PhenoAge clock, which may reflect a dysfunctional epigenetic aging process.

9.
Cancer Res ; 80(3): 367-374, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31694907

RESUMO

The incidence of cancer, adjusted for secular trends, is directly related to age, and advanced chronologic age is one of the most significant risk factors for cancer. Organismal aging is associated with changes at the molecular, cellular, and tissue levels and is affected by both genetic and environmental factors. The specific mechanisms through which these age-associated molecular changes contribute to the increased risk of aging-related disease, such as cancer, are incompletely understood. DNA methylation, a prominent epigenetic mark, also changes over a lifetime as part of an "epigenetic aging" process. Here, we give an update and review of epigenetic aging, in particular, the phenomena of epigenetic drift and epigenetic clock, with regard to its implication in cancer etiology. We discuss the discovery of the DNA methylation-based biomarkers for biological tissue age and the construction of various epigenetic age estimators for human clinical outcomes and health/life span. Recent studies in various types of cancer point to the significance of epigenetic aging in tumorigenesis and its potential use for cancer risk prediction. Future studies are needed to assess the potential clinical impact of strategies focused on lowering cancer risk by preventing premature aging or promoting healthy aging.

10.
Aging Cell ; 18(6): e13013, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31389184

RESUMO

The risk of colorectal cancer (CRC) varies between people, and the cellular mechanisms mediating the differences in risk are largely unknown. Senescence has been implicated as a causative cellular mechanism for many diseases, including cancer, and may affect the risk for CRC. Senescent fibroblasts that accumulate in tissues secondary to aging and oxidative stress have been shown to promote cancer formation via a senescence-associated secretory phenotype (SASP). In this study, we assessed the role of senescence and the SASP in CRC formation. Using primary human colon tissue, we found an accumulation of senescent fibroblasts in normal tissues from individuals with advanced adenomas or carcinomas in comparison with individuals with no polyps or CRC. In in vitro and ex vivo model systems, we induced senescence using oxidative stress in colon fibroblasts and demonstrated that the senescent fibroblasts secrete GDF15 as an essential SASP factor that promotes cell proliferation, migration, and invasion in colon adenoma and CRC cell lines as well as primary colon organoids via the MAPK and PI3K signaling pathways. In addition, we observed increased mRNA expression of GDF15 in primary normal colon tissue from people at increased risk for CRC in comparison with average risk individuals. These findings implicate the importance of a senescence-associated tissue microenvironment and the secretory factor GDF15 in promoting CRC formation.

11.
Contemp Clin Trials ; 84: 105820, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31400517

RESUMO

BACKGROUND: Clinical exome sequencing (CES) provides the advantage of assessing genetic variation across the human exome compared to a traditional stepwise diagnostic approach or multi-gene panels. Comparative effectiveness research methods offer an approach to better understand the patient-centered and economic outcomes of CES. PURPOSE: To evaluate CES compared to usual care (UC) in the diagnostic work-up of inherited colorectal cancer/polyposis (CRCP) in a randomized controlled trial (RCT). METHODS: The primary outcome was clinical sensitivity for the diagnosis of inherited CRCP; secondary outcomes included psychosocial outcomes, family communication, and healthcare resource utilization. Participants were surveyed 2 and 4 weeks after results return and at 3-month intervals up to 1 year. RESULTS: Evolving outcome measures and standard of care presented critical challenges. The majority of participants in the UC arm received multi-gene panels [94.73%]. Rates of genetic findings supporting the diagnosis of hereditary CRCP were 7.5% [7/93] vs. 5.4% [5/93] in the CES and UC arms, respectively (P = 0.28). Differences in privacy concerns after receiving CRCP results were identified (0.88 in UC vs 0.38 in CES, P = 0.05); however, healthcare resource utilization, family communication and psychosocial outcomes were similar between the two arms. More participants with positive results (17.7%) intended to change their life insurance 1  month after the first return visit compared to participants returned a variant of uncertain significance (9.1%) or negative result (4.8%) (P = 0.09). CONCLUSION: Our results suggest that CES provides similar clinical benefits to multi-gene panels in the diagnosis of hereditary CRCP.

13.
Gut ; 68(3): 389-399, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29884612

RESUMO

OBJECTIVE: To identify and characterise DNA methylation subtypes in oesophageal adenocarcinoma (EAC) and its precursor Barrett's oesophagus (BE). DESIGN: We performed genome-wide DNA methylation profiling on samples of non-dysplastic BE from cancer-free patients (n=59), EAC (n=23), normal squamous oesophagus (n=33) and normal fundus (n=9), and identified methylation subtypes using a recursively partitioned mixture model. We assessed genomic alterations for 9 BE and 22 EAC samples with massively parallel sequencing of 243 EAC-associated genes, and we conducted integrative analyses with transcriptome data to identify epigenetically repressed genes. We also carried out in vitro experiments treating EAC cell lines with 5-Aza-2'-Deoxycytidine (5-Aza-dC), short hairpin RNA knockdown and anticancer therapies. RESULTS: We identified and validated four methylation subtypes of EAC and BE. The high methylator subtype (HM) of EAC had the greatest number of activating events in ERBB2 (p<0.05, Student's t-test) and the highest global mutation load (p<0.05, Fisher's exact test). PTPN13 was silenced by aberrant methylation in the HM subtype preferentially and in 57% of EACs overall. In EAC cell lines, 5-Aza-dC treatment restored PTPN13 expression and significantly decreased its promoter methylation in HM cell lines (p<0.05, Welch's t-test). Inhibition of PTPN13 expression in the SK-GT-4 EAC cell line promoted proliferation, colony formation and migration, and increased phosphorylation in ERBB2/EGFR/Src kinase pathways. Finally, EAC cell lines showed subtype-specific responses to topotecan, SN-38 and palbociclib treatment. CONCLUSIONS: We identified and characterised methylator subtypes in BE and EAC. We further demonstrated the biological and clinical relevance of EAC methylator subtypes, which may ultimately help guide clinical management of patients with EAC.

14.
Cancer Res ; 79(3): 495-504, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30291105

RESUMO

Many normal tissues undergo age-related drift in DNA methylation, providing a quantitative measure of tissue age. Here, we identify and validate 781 CpG islands (CGI) that undergo significant methylomic drift in 232 normal colorectal tissues and show that these CGI continue to drift in neoplasia while retaining significant correlations across samples. However, compared with normal colon, this drift advanced (∼3-4-fold) faster in neoplasia, consistent with increased cell proliferation during neoplastic progression. The observed drift patterns were broadly consistent with modeled adenoma-to-carcinoma sojourn time distributions from colorectal cancer incidence data. These results support the hypothesis that, beginning with the founder premalignant cell, cancer precursors frequently sojourn for decades before turning into cancer, implying that the founder cell typically arises early in life. At least 77% to 89% of the observed drift variance in distal and rectal tumors was explained by stochastic variability associated with neoplastic progression, whereas only 55% of the variance was explained for proximal tumors. However, gene-CGI pairs in the proximal colon that underwent drift were significantly and primarily negatively correlated with cancer gene expression, suggesting that methylomic drift participates in the clonal evolution of colorectal cancer. Methylomic drift advanced in colorectal neoplasia, consistent with extended sojourn time distributions, which accounts for a significant fraction of epigenetic heterogeneity in colorectal cancer. Importantly, these estimated long-duration premalignant sojourn times suggest that early dietary and lifestyle interventions may be more effective than later changes in reducing colorectal cancer incidence. SIGNIFICANCE: These findings present age-related methylomic drift in colorectal neoplasia as evidence that premalignant cells can persist for decades before becoming cancerous.See related commentary by Sapienza, p. 437.


Assuntos
Neoplasias Colorretais/genética , Metilação de DNA , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/metabolismo , Ilhas de CpG , Epigênese Genética , Expressão Gênica , Humanos , Pessoa de Meia-Idade , Modelos Genéticos , Processos Estocásticos , Adulto Jovem
15.
Cancer Epidemiol Biomarkers Prev ; 28(3): 591-601, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30523039

RESUMO

BACKGROUND: Colorectal cancer is a leading cause of cancer death. Biomarkers to predict treatment outcomes are needed, as is evidence whether postdiagnosis diet and lifestyle can affect well-being and clinical outcomes. The international ColoCare Consortium aims to identify new biologic markers (e.g., metabolomic, transcriptomic, metagenomic, genetic, epigenetic, proteomic markers) that predict clinical outcomes, and to characterize associations between modifiable risk factors (e.g., diet, supplement use, physical activity) with short-term and long-term patient-reported and clinical outcomes among patients with colorectal cancer.Methods/Results: ColoCare is recruiting newly diagnosed patients with colorectal cancer across six sites in the United States and one site in Germany. As of April 2018, we have recruited >2,000 patients across all sites. Our projected enrollment is >4,000 multiethnic patients with colorectal cancer. The study includes uniformly collected, comprehensive sets of data and biospecimens at multiple time points up to 5 years after diagnosis. Treatment and clinical data are abstracted from medical records and centrally harmonized. Biospecimens are archived according to standardized procedures. Our initial studies demonstrated metabolic differences in adipose tissue types. We further reported on associations of biological factors (e.g., inflammation, DNA methylation, metabolomics) with lifestyle factors (e.g., adiposity, smoking, physical activity, dietary supplement use) or joint associations with clinical outcomes. CONCLUSIONS: ColoCare is a consortium for the investigation of multilevel factors relevant to colorectal cancer survivorship. IMPACT: The combination of a comprehensive set of biospecimens collected at multiple time points, jointly with detailed assessments of health behaviors and other prognostic factors, results in a unique resource that facilitates wide-ranging, innovative, and impactful research on colorectal cancer.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias Colorretais/mortalidade , Recidiva Local de Neoplasia/mortalidade , Qualidade de Vida , Idoso , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Terapia Combinada , Feminino , Seguimentos , Genômica , Humanos , Masculino , Metabolômica , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/terapia , Ensaios Clínicos Controlados não Aleatórios como Assunto , Medidas de Resultados Relatados pelo Paciente , Prognóstico , Estudos Prospectivos , Proteômica , Taxa de Sobrevida
16.
Int J Epidemiol ; 48(3): 767-780, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30476131

RESUMO

BACKGROUND: Chronic inflammation is a risk factor for colorectal cancer (CRC). Circulating C-reactive protein (CRP) is also moderately associated with CRC risk. However, observational studies are susceptible to unmeasured confounding or reverse causality. Using genetic risk variants as instrumental variables, we investigated the causal relationship between genetically elevated CRP concentration and CRC risk, using a Mendelian randomization approach. METHODS: Individual-level data from 30 480 CRC cases and 22 844 controls from 33 participating studies in three international consortia were used: the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), the Colorectal Transdisciplinary Study (CORECT) and the Colon Cancer Family Registry (CCFR). As instrumental variables, we included 19 single nucleotide polymorphisms (SNPs) previously associated with CRP concentration. The SNP-CRC associations were estimated using a logistic regression model adjusted for age, sex, principal components and genotyping phases. An inverse-variance weighted method was applied to estimate the causal effect of CRP on CRC risk. RESULTS: Among the 19 CRP-associated SNPs, rs1260326 and rs6734238 were significantly associated with CRC risk (P = 7.5 × 10-4, and P = 0.003, respectively). A genetically predicted one-unit increase in the log-transformed CRP concentrations (mg/l) was not associated with increased risk of CRC [odds ratio (OR) = 1.04; 95% confidence interval (CI): 0.97, 1.12; P = 0.256). No evidence of association was observed in subgroup analyses stratified by other risk factors. CONCLUSIONS: In spite of adequate statistical power to detect moderate association, we found genetically elevated CRP concentration was not associated with increased risk of CRC among individuals of European ancestry. Our findings suggested that circulating CRP is unlikely to be a causal factor in CRC development.


Assuntos
Proteína C-Reativa/metabolismo , Neoplasias Colorretais/epidemiologia , Idoso , Proteína C-Reativa/genética , Causalidade , Neoplasias Colorretais/genética , Feminino , Predisposição Genética para Doença , Humanos , Modelos Logísticos , Masculino , Análise da Randomização Mendeliana , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único
17.
Hum Genet ; 137(10): 795-806, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30267214

RESUMO

Although ~ 25% of colorectal cancer or polyp (CRC/P) cases show familial aggregation, current germline genetic testing identifies a causal genotype in the 16 major genes associated with high penetrance CRC/P in only 20% of these cases. As there are likely other genes underlying heritable CRC/P, we evaluated the association of variation at novel loci with CRC/P. We evaluated 158 a priori selected candidate genes by comparing the number of rare potentially disruptive variants (PDVs) found in 84 CRC/P cases without an identified CRC/P risk-associated variant and 2440 controls. We repeated this analysis using an additional 73 CRC/P cases. We also compared the frequency of PDVs in select genes among CRC/P cases with two publicly available data sets. We found a significant enrichment of PDVs in cases vs. controls: 20% of cases vs. 11.5% of controls with ≥ 1 PDV (OR = 1.9, p = 0.01) in the original set of cases. Among the second cohort of CRC/P cases, 18% had a PDV, significantly different from 11.5% (p = 0.02). Logistic regression, adjusting for ancestry and multiple testing, indicated association between CRC/P and PDVs in NTHL1 (p = 0.0001), BRCA2 (p = 0.01) and BRIP1 (p = 0.04). However, there was no significant difference in the frequency of PDVs at each of these genes between all 157 CRC/P cases and two publicly available data sets. These results suggest an increased presence of PDVs in CRC/P cases and support further investigation of the association of NTHL1, BRCA2 and BRIP1 variation with CRC/P.


Assuntos
Proteína BRCA2/genética , Neoplasias Colorretais/genética , Desoxirribonuclease (Dímero de Pirimidina)/genética , Proteínas de Grupos de Complementação da Anemia de Fanconi/genética , Loci Gênicos , Variação Genética , RNA Helicases/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
18.
Dev Cell ; 45(6): 738-752.e6, 2018 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-29920278

RESUMO

Normal cells acquire aggressive behavior by modifying signaling pathways. For instance, alteration of endocytosis profoundly impacts both proliferation and migration during tumorigenesis. Here we investigate the mechanisms that enable the endocytic machinery to coordinate these processes. We show that a membrane curvature-sensing protein, endophilin A3, promotes growth and migration of colon cancer cells through two competing mechanisms: an endocytosis pathway that is required for proliferation and a GTPase regulatory pathway that controls cell motility. EndoA3 stimulates cell migration by binding the Rac GEF TIAM1 leading to activation of small GTPases. Competing interactions of EndoA3 with membrane versus TIAM1 modulate hyperproliferative and metastatic phenotypes. Disruption of EndoA3-membrane interactions stimulates TIAM1 and small GTPases in vitro, and further promotes pro-metastatic phenotypes in vivo. Together, these results uncover a coupling mechanism, by which EndoA3 promotes growth and migration of colon cancers, by linking membrane dynamics to GTPase regulation.


Assuntos
Aciltransferases/metabolismo , Neoplasias do Colo/metabolismo , Proteína 1 Indutora de Invasão e Metástase de Linfoma de Células T/metabolismo , Animais , Carcinogênese/patologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Transformação Celular Neoplásica , Neoplasias do Colo/patologia , Endocitose/fisiologia , GTP Fosfo-Hidrolases/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Camundongos , Metástase Neoplásica , Transdução de Sinais , Peixe-Zebra , Proteínas rac1 de Ligação ao GTP/metabolismo
19.
Dig Dis Sci ; 63(8): 2059-2069, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29766388

RESUMO

Esophageal adenocarcinoma (EAC) develops from Barrett's esophagus (BE), a condition where the normal squamous epithelia is replaced by specialized intestinal metaplasia in response to chronic gastroesophageal acid reflux. In a minority of individuals, BE can progress to low- and high-grade dysplasia and eventually to intra-mucosal and then invasive carcinoma. BE provides researchers with a unique model to characterize the process by which a carcinoma arises from its precursor lesion. Molecular studies of BE have demonstrated that it is not simply a metaplastic tissue, but rather it harbors frequent alterations that are also present in dysplastic BE and in EAC. Both BE and EAC are characterized by loss of heterozygosity, aneuploidy, specific genetic mutations, and clonal diversity. Epigenetic abnormalities, primary alterations in DNA methylation, are also frequently seen in BE and EAC. Candidate gene and array-based approaches have demonstrated that numerous tumor suppressor genes exhibit aberrant promoter methylation, and some of these altered genes are associated with the neoplastic progression of BE. It has also been shown that the BE and EAC epigenomes are characterized by hypomethylation of intragenic and non-coding regions Recent studies have also provided new insight into the evolutionary forces underlying the molecular alterations seen in BE and EAC and into the molecular pathogenesis of EAC.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Evolução Molecular , Adenocarcinoma/patologia , Esôfago de Barrett/genética , Esôfago de Barrett/metabolismo , Esôfago de Barrett/patologia , Epigênese Genética/genética , Neoplasias Esofágicas/patologia , Esôfago/metabolismo , Esôfago/patologia , Humanos , Metaplasia/genética , Metaplasia/metabolismo , Metaplasia/patologia
20.
Br J Cancer ; 118(12): 1639-1647, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29795306

RESUMO

BACKGROUND: Substantial evidence supports an association between use of menopausal hormone therapy and decreased colorectal cancer (CRC) risk, indicating a role of exogenous sex hormones in CRC development. However, findings on endogenous oestrogen exposure and CRC are inconsistent. METHODS: We used a Mendelian randomisation approach to test for a causal effect of age at menarche and age at menopause as surrogates for endogenous oestrogen exposure on CRC risk. Weighted genetic risk scores based on 358 single-nucleotide polymorphisms associated with age at menarche and 51 single-nucleotide polymorphisms associated with age at menopause were used to estimate the association with CRC risk using logistic regression in 12,944 women diagnosed with CRC and 10,741 women without CRC from three consortia. Sensitivity analyses were conducted to address pleiotropy and possible confounding by body mass index. RESULTS: Genetic risk scores for age at menarche (odds ratio per year 0.98, 95% confidence interval: 0.95-1.02) and age at menopause (odds ratio 0.98, 95% confidence interval: 0.94-1.01) were not significantly associated with CRC risk. The sensitivity analyses yielded similar results. CONCLUSIONS: Our study does not support a causal relationship between genetic risk scores for age at menarche and age at menopause and CRC risk.


Assuntos
Neoplasias Colorretais/genética , Menarca/genética , Menopausa/genética , Fatores Etários , Estudos de Casos e Controles , Neoplasias Colorretais/epidemiologia , Feminino , Predisposição Genética para Doença , Humanos , Modelos Logísticos , Análise da Randomização Mendeliana , Polimorfismo de Nucleotídeo Único , Sistema de Registros
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