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1.
Nature ; 629(8013): 919-926, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38589574

RESUMO

RAS oncogenes (collectively NRAS, HRAS and especially KRAS) are among the most frequently mutated genes in cancer, with common driver mutations occurring at codons 12, 13 and 611. Small molecule inhibitors of the KRAS(G12C) oncoprotein have demonstrated clinical efficacy in patients with multiple cancer types and have led to regulatory approvals for the treatment of non-small cell lung cancer2,3. Nevertheless, KRASG12C mutations account for only around 15% of KRAS-mutated cancers4,5, and there are no approved KRAS inhibitors for the majority of patients with tumours containing other common KRAS mutations. Here we describe RMC-7977, a reversible, tri-complex RAS inhibitor with broad-spectrum activity for the active state of both mutant and wild-type KRAS, NRAS and HRAS variants (a RAS(ON) multi-selective inhibitor). Preclinically, RMC-7977 demonstrated potent activity against RAS-addicted tumours carrying various RAS genotypes, particularly against cancer models with KRAS codon 12 mutations (KRASG12X). Treatment with RMC-7977 led to tumour regression and was well tolerated in diverse RAS-addicted preclinical cancer models. Additionally, RMC-7977 inhibited the growth of KRASG12C cancer models that are resistant to KRAS(G12C) inhibitors owing to restoration of RAS pathway signalling. Thus, RAS(ON) multi-selective inhibitors can target multiple oncogenic and wild-type RAS isoforms and have the potential to treat a wide range of RAS-addicted cancers with high unmet clinical need. A related RAS(ON) multi-selective inhibitor, RMC-6236, is currently under clinical evaluation in patients with KRAS-mutant solid tumours (ClinicalTrials.gov identifier: NCT05379985).


Assuntos
Antineoplásicos , Mutação , Neoplasias , Proteína Oncogênica p21(ras) , Proteínas Proto-Oncogênicas p21(ras) , Animais , Humanos , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Guanosina Trifosfato/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Proteína Oncogênica p21(ras)/antagonistas & inibidores , Proteína Oncogênica p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Nature ; 629(8013): 927-936, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38588697

RESUMO

Broad-spectrum RAS inhibition has the potential to benefit roughly a quarter of human patients with cancer whose tumours are driven by RAS mutations1,2. RMC-7977 is a highly selective inhibitor of the active GTP-bound forms of KRAS, HRAS and NRAS, with affinity for both mutant and wild-type variants3. More than 90% of cases of human pancreatic ductal adenocarcinoma (PDAC) are driven by activating mutations in KRAS4. Here we assessed the therapeutic potential of RMC-7977 in a comprehensive range of PDAC models. We observed broad and pronounced anti-tumour activity across models following direct RAS inhibition at exposures that were well-tolerated in vivo. Pharmacological analyses revealed divergent responses to RMC-7977 in tumour versus normal tissues. Treated tumours exhibited waves of apoptosis along with sustained proliferative arrest, whereas normal tissues underwent only transient decreases in proliferation, with no evidence of apoptosis. In the autochthonous KPC mouse model, RMC-7977 treatment resulted in a profound extension of survival followed by on-treatment relapse. Analysis of relapsed tumours identified Myc copy number gain as a prevalent candidate resistance mechanism, which could be overcome by combinatorial TEAD inhibition in vitro. Together, these data establish a strong preclinical rationale for the use of broad-spectrum RAS-GTP inhibition in the setting of PDAC and identify a promising candidate combination therapeutic regimen to overcome monotherapy resistance.


Assuntos
Antineoplásicos , Carcinoma Ductal Pancreático , Guanosina Trifosfato , Neoplasias Pancreáticas , Proteínas Proto-Oncogênicas p21(ras) , Animais , Feminino , Humanos , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/patologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Variações do Número de Cópias de DNA , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Genes myc , Guanosina Trifosfato/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto , Mutação
3.
Cancer Discov ; 14(6): 994-1017, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38593348

RESUMO

RAS-driven cancers comprise up to 30% of human cancers. RMC-6236 is a RAS(ON) multi-selective noncovalent inhibitor of the active, GTP-bound state of both mutant and wild-type variants of canonical RAS isoforms with broad therapeutic potential for the aforementioned unmet medical need. RMC-6236 exhibited potent anticancer activity across RAS-addicted cell lines, particularly those harboring mutations at codon 12 of KRAS. Notably, oral administration of RMC-6236 was tolerated in vivo and drove profound tumor regressions across multiple tumor types in a mouse clinical trial with KRASG12X xenograft models. Translational PK/efficacy and PK/PD modeling predicted that daily doses of 100 mg and 300 mg would achieve tumor control and objective responses, respectively, in patients with RAS-driven tumors. Consistent with this, we describe here objective responses in two patients (at 300 mg daily) with advanced KRASG12X lung and pancreatic adenocarcinoma, respectively, demonstrating the initial activity of RMC-6236 in an ongoing phase I/Ib clinical trial (NCT05379985). SIGNIFICANCE: The discovery of RMC-6236 enables the first-ever therapeutic evaluation of targeted and concurrent inhibition of canonical mutant and wild-type RAS-GTP in RAS-driven cancers. We demonstrate that broad-spectrum RAS-GTP inhibition is tolerable at exposures that induce profound tumor regressions in preclinical models of, and in patients with, such tumors. This article is featured in Selected Articles from This Issue, p. 897.


Assuntos
Ensaios Antitumorais Modelo de Xenoenxerto , Humanos , Animais , Camundongos , Linhagem Celular Tumoral , Proteínas Proto-Oncogênicas p21(ras)/genética , Feminino , Antineoplásicos/uso terapêutico , Antineoplásicos/farmacologia , Guanosina Trifosfato/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Mutação , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Masculino
4.
bioRxiv ; 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38105998

RESUMO

Broad-spectrum RAS inhibition holds the potential to benefit roughly a quarter of human cancer patients whose tumors are driven by RAS mutations. However, the impact of inhibiting RAS functions in normal tissues is not known. RMC-7977 is a highly selective inhibitor of the active (GTP-bound) forms of KRAS, HRAS, and NRAS, with affinity for both mutant and wild type (WT) variants. As >90% of human pancreatic ductal adenocarcinoma (PDAC) cases are driven by activating mutations in KRAS, we assessed the therapeutic potential of RMC-7977 in a comprehensive range of PDAC models, including human and murine cell lines, human patient-derived organoids, human PDAC explants, subcutaneous and orthotopic cell-line or patient derived xenografts, syngeneic allografts, and genetically engineered mouse models. We observed broad and pronounced anti-tumor activity across these models following direct RAS inhibition at doses and concentrations that were well-tolerated in vivo. Pharmacological analyses revealed divergent responses to RMC-7977 in tumor versus normal tissues. Treated tumors exhibited waves of apoptosis along with sustained proliferative arrest whereas normal tissues underwent only transient decreases in proliferation, with no evidence of apoptosis. Together, these data establish a strong preclinical rationale for the use of broad-spectrum RAS inhibition in the setting of PDAC.

5.
Cell Rep Med ; 4(4): 101016, 2023 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-37075704

RESUMO

Nonalcoholic steatohepatitis (NASH) is the most common chronic liver disease globally and a leading cause for liver transplantation in the US. Its pathogenesis remains imprecisely defined. We combined two high-resolution modalities to tissue samples from NASH clinical trials, machine learning (ML)-based quantification of histological features and transcriptomics, to identify genes that are associated with disease progression and clinical events. A histopathology-driven 5-gene expression signature predicted disease progression and clinical events in patients with NASH with F3 (pre-cirrhotic) and F4 (cirrhotic) fibrosis. Notably, the Notch signaling pathway and genes implicated in liver-related diseases were enriched in this expression signature. In a validation cohort where pharmacologic intervention improved disease histology, multiple Notch signaling components were suppressed.


Assuntos
Aprendizado Profundo , Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/complicações , Transcriptoma/genética , Progressão da Doença , Cirrose Hepática/genética , Cirrose Hepática/tratamento farmacológico
6.
Cell ; 185(22): 4216-4232.e16, 2022 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-36240780

RESUMO

Genotype-phenotype associations for common diseases are often compounded by pleiotropy and metabolic state. Here, we devised a pooled human organoid-panel of steatohepatitis to investigate the impact of metabolic status on genotype-phenotype association. En masse population-based phenotypic analysis under insulin insensitive conditions predicted key non-alcoholic steatohepatitis (NASH)-genetic factors including the glucokinase regulatory protein (GCKR)-rs1260326:C>T. Analysis of NASH clinical cohorts revealed that GCKR-rs1260326-T allele elevates disease severity only under diabetic state but protects from fibrosis under non-diabetic states. Transcriptomic, metabolomic, and pharmacological analyses indicate significant mitochondrial dysfunction incurred by GCKR-rs1260326, which was not reversed with metformin. Uncoupling oxidative mechanisms mitigated mitochondrial dysfunction and permitted adaptation to increased fatty acid supply while protecting against oxidant stress, forming a basis for future therapeutic approaches for diabetic NASH. Thus, "in-a-dish" genotype-phenotype association strategies disentangle the opposing roles of metabolic-associated gene variant functions and offer a rich mechanistic, diagnostic, and therapeutic inference toolbox toward precision hepatology. VIDEO ABSTRACT.


Assuntos
Predisposição Genética para Doença , Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/genética , Organoides , Estudos de Associação Genética , Alelos , Fígado
7.
J Lipid Res ; 63(11): 100289, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36162519

RESUMO

FXR regulates bile acid metabolism, and FXR null (Fxr-/-) mice have elevated bile acid levels and progressive liver injury. The inositol-requiring enzyme 1α/X-box binding protein 1 (XBP1) pathway is a protective unfolded protein response pathway activated in response to endoplasmic reticulum stress. Here, we sought to determine the role of the inositol-requiring enzyme 1α/XBP1 pathway in hepatic bile acid toxicity using the Fxr-/- mouse model. Western blotting and quantitative PCR analysis demonstrated that hepatic XBP1 and other unfolded protein response pathways were activated in 24-week-old Fxr-/- compared with 10-week-old Fxr-/- mice but not in WT mice. To further determine the role of the liver XBP1 activation in older Fxr-/- mice, we generated mice with whole-body FXR and liver-specific XBP1 double KO (DKO, Fxr-/-Xbp1LKO) and Fxr-/-Xbp1fl/fl single KO (SKO) mice and characterized the role of hepatic XBP1 in cholestatic liver injury. Histologic staining demonstrated increased liver injury and fibrosis in DKO compared with SKO mice. RNA sequencing revealed increased gene expression in apoptosis, inflammation, and cell proliferation pathways in DKO mice. The proapoptotic C/EBP-homologous protein pathway and cell cycle marker cyclin D1 were also activated in DKO mice. Furthermore, we found that total hepatic bile acid levels were similar between the two genotypes. At age 60 weeks, all DKO mice and no SKO mice spontaneously developed liver tumors. In conclusion, the hepatic XBP1 pathway is activated in older Fxr-/- mice and has a protective role. The potential interaction between XBP1 and FXR signaling may be important in modulating the hepatocellular cholestatic stress responses.


Assuntos
Colestase , Fígado , Proteína 1 de Ligação a X-Box , Animais , Camundongos , Ácidos e Sais Biliares/metabolismo , Colestase/genética , Inositol/metabolismo , Fígado/metabolismo , Fígado/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 1 de Ligação a X-Box/genética
8.
Nat Genet ; 54(6): 761-771, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35654975

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is a growing cause of chronic liver disease. Using a proxy NAFLD definition of chronic elevation of alanine aminotransferase (cALT) levels without other liver diseases, we performed a multiancestry genome-wide association study (GWAS) in the Million Veteran Program (MVP) including 90,408 cALT cases and 128,187 controls. Seventy-seven loci exceeded genome-wide significance, including 25 without prior NAFLD or alanine aminotransferase associations, with one additional locus identified in European American-only and two in African American-only analyses (P < 5 × 10-8). External replication in histology-defined NAFLD cohorts (7,397 cases and 56,785 controls) or radiologic imaging cohorts (n = 44,289) replicated 17 single-nucleotide polymorphisms (SNPs) (P < 6.5 × 10-4), of which 9 were new (TRIB1, PPARG, MTTP, SERPINA1, FTO, IL1RN, COBLL1, APOH and IFI30). Pleiotropy analysis showed that 61 of 77 multiancestry and all 17 replicated SNPs were jointly associated with metabolic and/or inflammatory traits, revealing a complex model of genetic architecture. Our approach integrating cALT, histology and imaging reveals new insights into genetic liability to NAFLD.


Assuntos
Estudo de Associação Genômica Ampla , Hepatopatia Gordurosa não Alcoólica , Alanina Transaminase , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Lipase/genética , Proteínas de Membrana/genética , Hepatopatia Gordurosa não Alcoólica/genética , Polimorfismo de Nucleotídeo Único/genética , Proteínas Serina-Treonina Quinases/antagonistas & inibidores
9.
Therap Adv Gastroenterol ; 15: 17562848221098243, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35601801

RESUMO

Background: Longitudinal studies are needed to decipher mechanistic links between the gut microbiome and nonalcoholic steatohepatitis (NASH). We examined shifts in the gut microbiome in persons with NASH with improvement in liver stiffness measurement (LSM) by magnetic resonance (MR) elastography. Methods: Gut microbial profiling was performed at baseline and study completion (24 weeks) using 16 S rRNA gene sequencing in 69 adults with biopsy-confirmed NASH and significant fibrosis (stages 2-3) enrolled in a multi-center randomized controlled trial evaluating selonsertib alone or in combination with simtuzumab. Differential abundance of bacterial taxa at baseline and end of study were examined in participants with and without longitudinal improvement in LSM. Gut microbial shifts that correlated with secondary outcomes, including reduction in MR imaging-derived proton density fat faction (MRI-PDFF) and histologic fibrosis regression were evaluated. Fecal samples from 32 healthy adults were profiled and genus-level multidimensional scaling was used to determine if microbial shifts in persons with NASH improvement represented a shift toward a healthy gut microbiome. Results: Shifts in abundance of 36 bacterial taxa including Lactobacillus (log2FC = -4.51, FDR < 0.001), Enterococcus (log2FC = -6.72, FDR < 0.001), and Megasphaera (log2FC = 7.74, FDR < 0.001) were associated with improvement in LSM. Improvement in LSM was associated with microbial shifts toward healthy reference (p = 0.05). Significant shifts in 10 and 12 bacterial taxa were associated with improvement in LSM in addition to MRI-PDFF and fibrosis regression, respectively, indicating consistent taxonomic changes across multiple clinical endpoints. Conclusion: Longitudinal changes in the gut microbiota are observed in adults with NASH and clinical improvement and represent a shift toward a healthy microbiome.

10.
Clin Infect Dis ; 73(1): e184-e190, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32915202

RESUMO

BACKGROUND: Several chronic diseases accelerate biological aging. We investigated age acceleration and the association between peripheral blood DNA methylation (DNAm) and immune cell markers in patients chronically infected with the hepatitis B virus (HBV) or the hepatitis C virus (HCV) with and without human immunodeficiency virus (HIV) co-infection. METHODS: Age acceleration was measured as the difference between epigenetic age (Horvath clock) and chronological age. The immune marker model of age acceleration was developed using Elastic Net regression to select both the immune markers and their associated weights in the final linear model. RESULTS: Patients with chronic HBV (n = 51) had a significantly higher median epigenetic age compared to chronological age (age accelerated) (P < .001). In patients with chronic HCV infection (n = 63), age acceleration was associated with liver fibrosis as assessed by histology (P < .05), or presence of HIV co-infection (P < .05), but not HCV mono-infection. Age acceleration defined by immune markers was concordant with age acceleration by DNA methylation (correlation coefficient = .59 in HBV; P = .0025). One-year treatment of HBV patients with nucleoside therapy was associated with a modest reduction in age acceleration, as measured using the immune marker model (-.65 years, P = .018). CONCLUSION: Our findings suggest that patients with chronic viral hepatitis have accelerated epigenetic aging, that immune markers define biological age, and have the potential to assess the effects of therapeutic intervention on age acceleration.


Assuntos
Coinfecção , Infecções por HIV , Hepatite B Crônica , Hepatite B , Hepatite C , Envelhecimento , Biomarcadores , Metilação de DNA , Infecções por HIV/complicações , Hepacivirus , Vírus da Hepatite B/genética , Hepatite B Crônica/complicações , Humanos
11.
Hepatology ; 73(3): 1105-1116, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32745270

RESUMO

BACKGROUND AND AIMS: Primary sclerosing cholangitis (PSC) is a heterogeneous cholangiopathy characterized by progressive biliary fibrosis. RNA sequencing of liver tissue from patients with PSC (n = 74) enrolled in a 96-week clinical trial was performed to identify associations between biological pathways that were independent of fibrosis and clinical events. APPROACH AND RESULTS: The effect of fibrosis was subtracted from gene expression using a computational approach. The fibrosis-adjusted gene expression patterns were associated with time to first PSC-related clinical event (e.g., cholangitis, hepatic decompensation), and differential expression based on risk groups and Ingenuity Pathway Analysis were performed. Baseline demographic data were representative of PSC: median age 48 years, 71% male, 49% with inflammatory bowel disease, and 44% with bridging fibrosis or cirrhosis. The first principle component (PC1) of RNA-sequencing data accounted for 18% of variance and correlated with fibrosis stage (ρ = -0.80; P < 0.001). After removing the effect of fibrosis-related genes, the first principle component was not associated with fibrosis (ρ = -0.19; P = 0.11), and a semisupervised clustering approach identified two distinct patient clusters with differential risk of time to first PSC-related event (P < 0.0001). The two groups had similar fibrosis stage, hepatic collagen content, and α-smooth muscle actin expression by morphometry, Enhanced Liver Fibrosis score, and serum liver biochemistry, bile acids, and IL-8 (all P > 0.05). The top pathways identified by Ingenuity Pathway Analysis were eukaryotic translation inhibition factor 2 (eIF2) signaling and regulation of eIF4/p70S6K signaling. Genes involved in the unfolded protein response, activating transcription factor 6 (ATF6) and eIF2, were differentially expressed between the PSC clusters (down-regulated in the high-risk group by log-fold changes of -0.18 [P = 0.02] and -0.16 [P = 0.02], respectively). Clinical events were enriched in the high-risk versus low-risk group (38% [12/32] vs. 2.4% [1/42], P < 0.0001). CONCLUSIONS: Removing the contribution of fibrosis-related pathways uncovered alterations in the unfolded protein response, which were associated with liver-related complications in PSC.


Assuntos
Colangite Esclerosante/patologia , Cirrose Hepática/metabolismo , Transcriptoma , Ácidos e Sais Biliares/química , Biomarcadores/análise , Biópsia , Colangite Esclerosante/metabolismo , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Humanos , Interleucina-8/análise , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal
12.
JHEP Rep ; 2(1): 100060, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32039401

RESUMO

BACKGROUND & AIMS: A DNA methylation (DNAm) signature derived from 353 CpG sites (the Horvath clock) has been proposed as an epigenetic measure of chronological and biological age. This epigenetic signature is accelerated in diverse tissue types in various disorders, including non-alcoholic steatohepatitis, and is associated with mortality. Here, we assayed whole blood DNAm to explore age acceleration in patients with primary sclerosing cholangitis (PSC). METHODS: Using the MethylationEPIC BeadChip (850K) array, DNAm signatures in whole blood were analyzed in 36 patients with PSC enrolled in a 96-week trial of simtuzumab (Ishak F0-1, n = 13; F5-6, n = 23). Age acceleration was calculated as the difference between DNAm age and chronological age. Comparisons between patients with high and low age acceleration (≥ vs. < the median) were made and Cox regression evaluated the association between age acceleration and PSC-related clinical events (e.g. decompensation, cholangitis, transplantation). RESULTS: Age acceleration was significantly higher in patients with PSC compared to a healthy reference cohort (median, 11.1 years, p <2.2 × 10-16). In PSC, demographics, presence of inflammatory bowel disease, and ursodeoxycholic acid use were similar between patients with low and high age acceleration. However, patients with high age acceleration had increased serum alkaline phosphatase, gamma glutamyltransferase, alanine aminotransferase, enhanced liver fibrosis test scores, and greater hepatic collagen and α-smooth muscle actin expression on liver biopsy (all p <0.05). Moreover, patients with high age acceleration had an increased prevalence of cirrhosis (89% vs. 39%; p = 0.006) and greater likelihood of PSC-related events (hazard ratio 4.19; 95% CI 1.15-15.24). CONCLUSION: This analysis of blood DNAm profiles suggests that compared with healthy controls, patients with PSC - particularly those with cirrhosis - exhibit significant acceleration of epigenetic age. Future studies are required to evaluate the prognostic implications and effect of therapies on global methylation patterns and age acceleration in PSC. LAY SUMMARY: An epigenetic clock based on DNA methylation has been proposed as a marker of age. In liver diseases such as non-alcoholic steatohepatitis, age acceleration based on this epigenetic clock has been observed. Herein, we show that patients with primary sclerosing cholangitis have marked age acceleration, which is further accentuated by worsening fibrosis. This measure of age acceleration could be a useful marker for prognostication or risk stratification in primary sclerosing cholangitis.

13.
JCI Insight ; 3(2)2018 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-29367468

RESUMO

A DNA methylation (DNAm) signature (the "Horvath clock") has been proposed as a measure of human chronological and biological age. We determined peripheral blood DNAm in patients with nonalcoholic steatohepatitis (NASH) and assessed whether accelerated aging occurs in these patients. DNAm signatures were obtained in patients with biopsy-proven NASH and stage 2-3 fibrosis. The DNAm profile from one test and two validation cohorts served as controls. Age acceleration was calculated as the difference between DNAm age and the predicted age based on the linear model derived from controls. Hepatic collagen content was assessed by quantitative morphometry. The Horvath clock accurately predicts the chronological age of the entire cohort. Age acceleration was observed among NASH subjects compared with control data sets and our test controls. Age acceleration in NASH subjects did not differ by fibrosis stage but correlated with hepatic collagen content. A set of 152 differentially methylated CpG islands between NASH subjects and controls identified gene set enrichment for transcription factors and developmental pathways. Patients with NASH exhibit epigenetic age acceleration that correlates with hepatic collagen content.


Assuntos
Senilidade Prematura/diagnóstico , Metilação de DNA , Epigênese Genética , Fígado/patologia , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Adulto , Idoso , Senilidade Prematura/sangue , Senilidade Prematura/patologia , Biomarcadores/sangue , Biópsia , Estudos de Casos e Controles , Ensaios Clínicos Fase II como Assunto , Colágeno/análise , Ilhas de CpG/genética , Conjuntos de Dados como Assunto , Feminino , Fibrose , Humanos , Fígado/química , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/patologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Índice de Gravidade de Doença
14.
Nat Commun ; 7: 12498, 2016 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-27502118

RESUMO

Resistance to oestrogen-deprivation therapy is common in oestrogen-receptor-positive (ER+) breast cancer. To better understand the contributions of tumour heterogeneity and evolution to resistance, here we perform comprehensive genomic characterization of 22 primary tumours sampled before and after 4 months of neoadjuvant aromatase inhibitor (NAI) treatment. Comparing whole-genome sequencing of tumour/normal pairs from the two time points, with coincident tumour RNA sequencing, reveals widespread spatial and temporal heterogeneity, with marked remodelling of the clonal landscape in response to NAI. Two cases have genomic evidence of two independent tumours, most obviously an ER- 'collision tumour', which was only detected after NAI treatment of baseline ER+ disease. Many mutations are newly detected or enriched post treatment, including two ligand-binding domain mutations in ESR1. The observed clonal complexity of the ER+ breast cancer genome suggests that precision medicine approaches based on genomic analysis of a single specimen are likely insufficient to capture all clinically significant information.


Assuntos
Inibidores da Aromatase/farmacologia , Aromatase/metabolismo , Neoplasias da Mama/metabolismo , Receptores de Estrogênio/metabolismo , Alelos , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Células Clonais , Feminino , Genoma Humano , Humanos , Mutação/genética
15.
Front Genet ; 6: 233, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26191074

RESUMO

Osteosarcoma is the most common type of bone cancer in children and adolescents. Impaired differentiation of osteoblast cells is a distinguishing feature of this aggressive disease. As improvements in survival outcomes have largely plateaued, better understanding of the bone differentiation program may provide new treatment approaches. The miRNA cluster miR-23a~27a~24-2, particularly miR-23a, has been shown to interact with genes important for bone development. However, global changes in gene expression associated with functional gain of this cluster have not been fully explored. To better understand the relationship between miR-23a expression and bone cell differentiation, we carried out a large-scale gene expression analysis in HOS cells. Experimental results demonstrate that over-expression of miR-23a delays differentiation in this system. Downstream bioinformatic analysis identified miR-23a target gene connexin-43 (Cx43/GJA1), a mediator of intercellular signaling critical to osteoblast development, as acutely affected by miR-23a levels. Connexin-43 is up-regulated in the course of HOS cell differentiation and is down-regulated in cells transfected with miR-23a. Analysis of gene expression data, housed at Gene Expression Omnibus, reveals that Cx43 is consistently up-regulated during osteoblast differentiation. Suppression of Cx43 mRNA by miR-23a was confirmed in vitro using a luciferase reporter assay. This work demonstrates novel interactions between microRNA expression, intercellular signaling and bone differentiation in osteosarcoma.

16.
Front Genet ; 5: 378, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25404939

RESUMO

Eukaryotic DNA replication follows a strict temporal program where genomic loci are replicated at precise times during the S phase of the cell cycle. Yet, the mechanism in control of the timing program in metazoan cells is poorly understood. In a recent publication, the authors proposed an intuitive stochastic model of DNA replication and showed that it predicts replication timing with an accuracy approaching the level of experimental biological repeats. Here, we discuss an extended software implementation of the mechanistic model: Replicon. This package allows interested researchers to predict the global replication timing program in human cells from chromatin data.

17.
Mol Syst Biol ; 10: 722, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24682507

RESUMO

The metazoan genome is replicated in precise cell lineage-specific temporal order. However, the mechanism controlling this orchestrated process is poorly understood as no molecular mechanisms have been identified that actively regulate the firing sequence of genome replication. Here, we develop a mechanistic model of genome replication capable of predicting, with accuracy rivaling experimental repeats, observed empirical replication timing program in humans. In our model, replication is initiated in an uncoordinated (time-stochastic) manner at well-defined sites. The model contains, in addition to the choice of the genomic landmark that localizes initiation, only a single adjustable parameter of direct biological relevance: the number of replication forks. We find that DNase-hypersensitive sites are optimal and independent determinants of DNA replication initiation. We demonstrate that the DNA replication timing program in human cells is a robust emergent phenomenon that, by its very nature, does not require a regulatory mechanism determining a proper replication initiation firing sequence.


Assuntos
Cromatina/ultraestrutura , Período de Replicação do DNA/genética , Replicação do DNA/genética , Cromatina/genética , Genoma Humano , Humanos , Modelos Genéticos , Origem de Replicação/genética
19.
Cancer Res ; 73(14): 4372-82, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23856246

RESUMO

The NCI-60 cell lines are the most frequently studied human tumor cell lines in cancer research. This panel has generated the most extensive cancer pharmacology database worldwide. In addition, these cell lines have been intensely investigated, providing a unique platform for hypothesis-driven research focused on enhancing our understanding of tumor biology. Here, we report a comprehensive analysis of coding variants in the NCI-60 panel of cell lines identified by whole exome sequencing, providing a list of possible cancer specific variants for the community. Furthermore, we identify pharmacogenomic correlations between specific variants in genes such as TP53, BRAF, ERBBs, and ATAD5 and anticancer agents such as nutlin, vemurafenib, erlotinib, and bleomycin showing one of many ways the data could be used to validate and generate novel hypotheses for further investigation. As new cancer genes are identified through large-scale sequencing studies, the data presented here for the NCI-60 will be an invaluable resource for identifying cell lines with mutations in such genes for hypothesis-driven research. To enhance the utility of the data for the greater research community, the genomic variants are freely available in different formats and from multiple sources including the CellMiner and Ingenuity websites.


Assuntos
Ensaios de Seleção de Medicamentos Antitumorais/métodos , Exoma , Neoplasias/tratamento farmacológico , Neoplasias/genética , Antineoplásicos , Linhagem Celular Tumoral , Variação Genética , Humanos , Mutação , Farmacogenética/métodos
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