RESUMO
Hepatocellular carcinoma (HCC), the most common primary malignant tumor of the liver, often associated with the dysregulation of transcriptional pathways involved in cell growth and differentiation. The hematopoietically expressed homeobox protein (Hhex) is an important transcription factor throughout liver development and is essential to liver bud formation and hepatoblast differentiation. Here, we report a relationship between Hhex expression and HCC. First, adenovirus-mediated Hhex delivery into the hepatoma cell line, Hepa1-6, resulted in decreased expression of several proto-oncogenes (c-Jun and Bcl2), increased expression of some tumor suppressor genes (P53 and Rb), and enhanced expression of a cluster of hepatocytic and bile ductular markers. Second, Hhex expression significantly attenuated Hepa1-6 tumorigenicity in nude mice. Third, we report a correlation between Hhex expression and the differentiation state of human HCC. In 24 cases of clinical specimens, there was a significant difference in Hhex expression between poorly differentiated HCC and well-differentiated HCC (P < 0.001). Taken together, these results indicate that Hhex is a potential candidate molecular marker for HCC pathological evaluation, suggesting a need to evaluate Hhex as a potential target for therapeutic intervention.
Assuntos
Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Diferenciação Celular , Proteínas de Homeodomínio/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Fatores de Transcrição/metabolismo , Animais , Apoptose , Western Blotting , Carcinoma Hepatocelular/genética , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , Humanos , Técnicas Imunoenzimáticas , Neoplasias Hepáticas/genética , Masculino , Camundongos , Camundongos Nus , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética , Ensaio Tumoral de Célula-TroncoRESUMO
BMI-1 (B-cell-specific Moloney murine leukemia virus integration site 1), a novel oncogene, has attracted much attention in recent years for its involvement in the initiation of a variety of tumors. Recent evidence showed that BMI-1 was highly expressed in neoplastic skin lesions. However, whether dysregulated BMI-1 expression is causal for the transformation of skin cells remains unknown. In this study, we stably expressed BMI-1 in a human keratinocyte cell line, HaCaT. The expression of wild-type BMI-1 induced the malignant transformation of HaCaT cells in vitro. More importantly, we found that expression of BMI-1 promoted formation of squamous cell carcinomas in vivo. Furthermore, we showed that BMI-1 expression led to the downregulation of tumor suppressors, such as p16INK4a and p14ARF, cell adhesion molecules, such as E-Cadherin, and differentiation related factor, such as KRT6. Therefore, our findings demonstrated that dysregulated BMI-1 could indeed lead to keratinocytes transformation and tumorigenesis, potentially through promoting cell cycle progression and increasing cell mobility.
