Let-7a microRNA functions as a potential tumor suppressor in human laryngeal cancer.
Oncol Rep
; 22(5): 1189-95, 2009 Nov.
Article
em En
| MEDLINE
| ID: mdl-19787239
ABSTRACT
MicroRNAs (miRNAs) are endogenously expressed non-coding RNAs, which are involved in the gene expression regulation. Lethal-7a (let-7a) is a founding member of miRNA family and recently it was found to be associated with several cancers, such as lung and colon cancers. In the present study, we found that let-7a miRNA expression was significantly downregulated both in human laryngeal squamous cancer tissues and in Hep-2 cells, a laryngeal cancer cell line, as compared with adjacent normal tissues and BEAS-2B cells, respectively. Moreover, we found that let-7a expression levels were significantly further decreased in non-differentiated (G3) cancer tissues as compared with moderately and well differentiated cancer tissues (G2 and G1), although no significant difference in let-7a expression levels between the cancer specimens with different T stages or specimens from patients with different lymph node metastasis status was revealed. In Hep-2 cells, let-7a mimics transfection markedly suppressed proliferation and induced apoptosis of Hep-2 cells under the treatment of diamminedichloroplatinum or not and downregulated RAS and c-MYC protein expression without affecting the mRNA levels. In parallel, RAS and c-MYC protein levels were found significantly upregulated only in cancer tissues with downregulated let-7a expression. Thus, we propose that let-7a may be a tumor suppressor in laryngeal cancer by inhibiting cell growth, inducing cell apoptosis and downregulating the oncogenes expression.
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Bases de dados:
MEDLINE
Assunto principal:
Carcinoma de Células Escamosas
/
Regulação Neoplásica da Expressão Gênica
/
Neoplasias Laríngeas
/
Genes Supressores de Tumor
/
MicroRNAs
Tipo de estudo:
Prognostic_studies
Limite:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Oncol Rep
Assunto da revista:
NEOPLASIAS
Ano de publicação:
2009
Tipo de documento:
Article