RESUMO
OBJECTIVE: The RHO family of GTPases, particularly RAC1, has been linked with hepatocarcinogenesis, suggesting that their inhibition might be a rational therapeutic approach. We aimed to identify and target deregulated RHO family members in human hepatocellular carcinoma (HCC). DESIGN: We studied expression deregulation, clinical prognosis and transcription programmes relevant to HCC using public datasets. The therapeutic potential of RAC1 inhibitors in HCC was study in vitro and in vivo. RNA-Seq analysis and their correlation with the three different HCC datasets were used to characterise the underlying mechanism on RAC1 inhibition. The therapeutic effect of RAC1 inhibition on liver fibrosis was evaluated. RESULTS: Among the RHO family of GTPases we observed that RAC1 is upregulated, correlates with poor patient survival, and is strongly linked with a prooncogenic transcriptional programme. From a panel of novel RAC1 inhibitors studied, 1D-142 was able to induce apoptosis and cell cycle arrest in HCC cells, displaying a stronger effect in highly proliferative cells. Partial rescue of the RAC1-related oncogenic transcriptional programme was obtained on RAC1 inhibition by 1D-142 in HCC. Most importantly, the RAC1 inhibitor 1D-142 strongly reduce tumour growth and intrahepatic metastasis in HCC mice models. Additionally, 1D-142 decreases hepatic stellate cell activation and exerts an anti-fibrotic effect in vivo. CONCLUSIONS: The bioinformatics analysis of the HCC datasets, allows identifying RAC1 as a new therapeutic target for HCC. The targeted inhibition of RAC1 by 1D-142 resulted in a potent antitumoural effect in highly proliferative HCC established in fibrotic livers.
Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Inibidores Enzimáticos/farmacologia , Guanidinas/uso terapêutico , Cirrose Hepática/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Proteínas rac1 de Ligação ao GTP/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Carcinogênese/genética , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/secundário , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Biologia Computacional , Bases de Dados Genéticas , Inibidores Enzimáticos/uso terapêutico , Guanidinas/farmacologia , Células Estreladas do Fígado/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Camundongos , Terapia de Alvo Molecular , Transplante de Neoplasias , Transcriptoma/efeitos dos fármacos , Proteínas rac1 de Ligação ao GTP/genética , Proteínas rho de Ligação ao GTP/antagonistas & inibidores , Proteínas rho de Ligação ao GTP/genéticaRESUMO
BACKGROUND & AIMS: A causal link has recently been established between epigenetic alterations and hepatocarcinogenesis, indicating that epigenetic inhibition may have therapeutic potential. We aimed to identify and target epigenetic modifiers that show molecular alterations in hepatocellular carcinoma (HCC). METHODS: We studied the molecular-clinical correlations of epigenetic modifiers including bromodomains, histone acetyltransferases, lysine methyltransferases and lysine demethylases in HCC using The Cancer Genome Atlas (TCGA) data of 365 patients with HCC. The therapeutic potential of epigenetic inhibitors was evaluated in vitro and in vivo. RNA sequencing analysis and its correlation with expression and clinical data in the TCGA dataset were used to identify expression programs normalized by Jumonji lysine demethylase (JmjC) inhibitors. RESULTS: Genetic alterations, aberrant expression, and correlation between tumor expression and poor patient prognosis of epigenetic enzymes are common events in HCC. Epigenetic inhibitors that target bromodomain (JQ-1), lysine methyltransferases (BIX-1294 and LLY-507) and JmjC lysine demethylases (JIB-04, GSK-J4 and SD-70) reduce HCC aggressiveness. The pan-JmjC inhibitor JIB-04 had a potent antitumor effect in tumor bearing mice. HCC cells treated with JmjC inhibitors showed overlapping changes in expression programs related with inhibition of cell proliferation and induction of cell death. JmjC inhibition reverses an aggressive HCC gene expression program that is also altered in patients with HCC. Several genes downregulated by JmjC inhibitors are highly expressed in tumor vs. non-tumor parenchyma, and their high expression correlates with a poor prognosis. We identified and validated a 4-gene expression prognostic signature consisting of CENPA, KIF20A, PLK1, and NCAPG. CONCLUSIONS: The epigenetic alterations identified in HCC can be used to predict prognosis and to define a subgroup of high-risk patients that would potentially benefit from JmjC inhibitor therapy. LAY SUMMARY: In this study, we found that mutations and changes in expression of epigenetic modifiers are common events in human hepatocellular carcinoma, leading to an aggressive gene expression program and poor clinical prognosis. The transcriptional program can be reversed by pharmacological inhibition of Jumonji enzymes. This inhibition blocks hepatocellular carcinoma progression, providing a novel potential therapeutic strategy.
Assuntos
Antineoplásicos/farmacologia , Carcinogênese , Carcinoma Hepatocelular , Epigênese Genética/efeitos dos fármacos , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Neoplasias Hepáticas , Animais , Carcinogênese/efeitos dos fármacos , Carcinogênese/genética , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/enzimologia , Carcinoma Hepatocelular/genética , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Proteína Centromérica A/genética , Descoberta de Drogas , Humanos , Cinesinas/genética , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/enzimologia , Neoplasias Hepáticas/genética , Camundongos , Mutação , Prognóstico , Proteínas Serina-Treonina Quinases/genética , Proteínas Proto-Oncogênicas/genética , Transcriptoma , Quinase 1 Polo-LikeRESUMO
We have uncovered a role for Jumonji inhibitors in overcoming radioresistance through KDM5B inhibition. Pharmacological blockade of Jumonji demethylases with JIB-04 leads to specific accumulation of H3K4me3 at sites marked by γH2AX and impaired recruitment of DNA repair factors, preventing resolution of damage and resulting in robust sensitization to radiation therapy. In DNA-repair-proficient cancer cells, knockdown of the H3K4me3 demethylase KDM5B, but not other Jumonji enzymes, mimics pharmacological inhibition, and KDM5B overexpression rescues this phenotype and increases radioresistance. The H3K4me3 demethylase inhibitor PBIT also sensitizes cancer cells to radiation, while an H3K27me3 demethylase inhibitor does not. In vivo co-administration of radiation with JIB-04 significantly prolongs the survival of mice with tumors even long after cessation of treatment. In human patients, lung squamous cell carcinomas highly expressing KDM5B respond poorly to radiation. Thus, we propose the use of Jumonji KDM inhibitors as potent radiosensitizers.
Assuntos
Quebras de DNA de Cadeia Dupla , Histonas/metabolismo , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Tolerância a Radiação , Aminopiridinas/farmacologia , Animais , Benzazepinas/farmacologia , Linhagem Celular Tumoral , Quebras de DNA de Cadeia Dupla/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Proteína Quinase Ativada por DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Desmetilação , Feminino , Humanos , Hidrazonas/farmacologia , Histona Desmetilases com o Domínio Jumonji/metabolismo , Metilação/efeitos dos fármacos , Camundongos Nus , Proteínas Nucleares/metabolismo , Pirimidinas/farmacologia , Rad51 Recombinase/metabolismo , Tolerância a Radiação/efeitos dos fármacos , Análise de Sobrevida , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismoRESUMO
Using methods of community-based participatory research, a prospective randomized controlled trial of a violence prevention program based on Latino cultural values was implemented with elementary school children in a Mexican American community. Community members participated in intervention program selection, implementation, and data collection. High-risk students who participated in the program had greater nonviolent self-efficacy and demonstrated greater endorsement of program values than did high-risk students in the control group. This collaborative partnership was able to combine community-based participatory research with a rigorous study design and provide sustained benefit to community partners.