RESUMEN
OBJECTIVE: To investigate the expression of LTF mRNA in several nasopharyngeal cancer (NPC) cell lines, and analyze the relationship between the genetic and epigenetic changes and expression of LTF gene. METHODS: The expression level of LTF was detected in NPC cell lines HNE1, HNE2, HNE3, CNE1, CNE2, 5-8F, 6-10B cells and tissues of 15 cases of chronic nasopharyngitis by RT-PCR. The LTF protein level was analyzed by Western blotting in 6-10B cells. Then LOH, mutation and methylation status of LTF was examined by microsatellites analysis, PCR-SSCP, MSP and bisulfite genomic sequencing, respectively. RESULTS: 15 chronic nasopharyngitis tissues showed stable LTF expression, while there were weak expression in 6-10B cells and absent expression in remaining detected NPC cell lines. There was a significantly lower LTF expression in chronic nasopharyngitis tissues (Z = -3.738, P = 0.000). No LTF protein expression was observed in 6-10B cells. LOH analysis demonstrated that allele loss of LTF wasn't found in NPC cell lines. LTF mutation was noted in 14.3% (1/7) of NPC cell lines. DNA sequencing confirmed the mutation point in the promoter region (-305 bp to -50 bp) was at -218 bp (del T) of LTF gene in the HNE1 cell line. Methylation of LTF gene was not found in chronic nasopharyngitis. However, methylation of LTF promoter was detected in all NPC cell lines. LTF mRNA expression was increased in 5-8F and 6-10B cell lines after treatment with 5-aza-2-deoxycytidine. CONCLUSION: There is an inactivation of expression of LTF gene in the NPC cell lines. Its molecular mechanism may be related with methylation of promoter region and deletion mutation.
Asunto(s)
Epigénesis Genética , Lactoferrina/genética , Lactoferrina/metabolismo , Neoplasias Nasofaríngeas/genética , Antimetabolitos Antineoplásicos/farmacología , Azacitidina/análogos & derivados , Azacitidina/farmacología , Línea Celular Tumoral , Metilación de ADN , Decitabina , Eliminación de Gen , Humanos , Pérdida de Heterocigocidad , Neoplasias Nasofaríngeas/metabolismo , Neoplasias Nasofaríngeas/patología , Nasofaringitis/genética , Nasofaringitis/metabolismo , Regiones Promotoras Genéticas/genética , ARN Mensajero/metabolismoRESUMEN
OBJECTIVE: To investigate the best combination of monoclonal antibodies for the diagnosis of hepatobiliary intraepithelial neoplasia and/or cancer. METHODS: CK7, CK20, Villin, CEA, P53 and Ki-67 antigens were detected in the tissues of high-level hepatobiliary intraepithelial neoplasia and cancer by immunohistochemistry and the results were analyzed statistically. RESULTS: Villin was 100% positive in hepatobiliary intraepithelial neoplasia and/or cancer, while 100% negative in the adjacent normal bile duct epithelium. The expression rate of CEA was significantly lower in high-level hepatobiliary intraepithelial neoplasia tissues than in the cancer tissues (P<0.05). Ki-67 indexes were significantly lower in most of the high-level hepatobiliary intraepithelial neoplasia than in the cancer tissue (P<0.01). P53 indexes were also lower in high-level hepatobiliary intraepithelial neoplasia (P<0.01). CONCLUSION: Detection of multiple antigens (CEA, Villin, Ki-67 and P53) provides specific clues to the diagnosis of high-grade hepatobiliary intraepithelial neoplasia and/or cancer.