RESUMO
The carcinogenicity of chemicals in the environment is a major concern. Recently, numerous studies have attempted to develop methods for predicting carcinogenicity, including rodent and cell-based approaches. However, rodent carcinogenicity tests for evaluating the carcinogenic potential of a chemical to humans are time-consuming and costly. This study focused on the development of an alternative method for predicting carcinogenicity using quantitative PCR (qPCR) and colon cancer stem cells. A toxicogenomic method, mRNA profiling, is useful for predicting carcinogenicity. Using microarray analysis, we optimized 16 predictive gene sets from five carcinogens (azoxymethane, 3,2'-dimethyl-4-aminobiphenyl, N-ethyl-n-nitrosourea, metronidazole, 4-(n-methyl-n-nitrosamino)-1-(3-pyridyl)-1-butanone) used to treat colon cancer stem cell samples. The 16 genes were evaluated by qPCR using 23 positive and negative carcinogens in colon cancer stem cells. Among them, six genes could differentiate between positive and negative carcinogens with a p-value of < or =0.05. Our qPCR-based prediction system for colon carcinogenesis using colon cancer stem cells is cost- and time-efficient. Thus, this qPCR-based prediction system is an alternative to in vivo carcinogenicity screening assays.
Assuntos
Carcinogênese/genética , Testes de Carcinogenicidade/métodos , Carcinógenos/toxicidade , Neoplasias do Colo/induzido quimicamente , Neoplasias do Colo/genética , Células-Tronco Neoplásicas , Reação em Cadeia da Polimerase em Tempo Real/métodos , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Testes de Carcinogenicidade/economia , Sobrevivência Celular/efeitos dos fármacos , Colo , Primers do DNA , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica/genética , Redes Reguladoras de Genes , Células HCT116 , Humanos , Técnicas In Vitro , RNA Mensageiro/análise , Reação em Cadeia da Polimerase em Tempo Real/economia , Fatores de TempoRESUMO
Benzo[a]pyrene (B[a]P), a polycyclic aromatic hydrocarbon, is a principal component of cigarette smoke. B[a]P can cause lung carcinogenesis and plays a key role in lung cancer progression. The role of B[a]P has been reported in lung cancer, but its effects on lung cancer stem cells (CSCs) have not been investigated. Emerging evidence indicates that CSCs are associated with carcinogenesis, tumor initiation, relapse, and metastasis. Therefore, targeting CSCs to defeat cancer is a challenging issue in the clinic. This study explored whether B[a]P alters gene expression in lung cancer cells and CSCs. The lung adenocarcinoma A549 cell line was used to investigate the role of B[a]P on lung cancer cells and lung CSCs using microarray and quantitative PCR. B[a]P (1 µM) provoked gene expression changes in A549 cancer cells and CSCs by deregulating numerous genes. Gene pathway analysis was performed using GeneMANIA and GIANT. We identified genes that were coexpressed and showed physical interactions. These findings improve our understanding of the mechanism of B[a]P in lung cancer and cancer stem cells and can be an attractive therapeutic target.