RESUMEN
BACKGROUND: Hepatocellular carcinoma, a lethal malignant neoplasm with poor prognosis, has dismal results of surgical resection and chemoradiotherapy. Norcantharidin (NCTD), the demethylated analog of cantharidin derived from a traditional Chinese medicine, Mylabris, has been used in the treatment of cancer. However, the detailed mechanisms underlying this process are generally unclear. PURPOSE: The aim of this study was to investigate the mechanism of NCTD-induced apoptosis in HepG2 cells. MATERIALS AND METHODS: Human HepG2 cell lines were treated with NCTD at different concentrations (2.50, 5.00, 10.00, 20.00, 40.00 µg/mL) for 24 hours. Cell proliferation was evaluated by measurement of cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). The methylation levels of RASSF1A (Ras-association domain family 1 A) in HepG2 cells were detected by methylation-specific PCR (MSP). The mRNA levels of RASSF1A in HepG2 cells were detected by real-time fluorescent quantitative PCR (RT-PCR). The levels of RASSF1A protein expression of HepG2 cells were detected by Western blotting assay. RESULTS: The inhibition of cell proliferation was observed when treated with NCTD at concentrations (2.5 µg/mL), and as concentration increased, the proliferation of HepG2 cells was markedly inhibited by NCTD in dose-dependent manners. The levels of methylation of RASSF1A decreased at the increasing concentration of 10, 20 and 40 µg/mL. The levels of RASSF1A mRNA and protein were decreased when treated with NCTD at the concentrations of 10, 20 and 40 µg/mL, which were also in a dose-dependent manner. CONCLUSION: NCTD can reverse the methylation state of RASSF1A gene and induce its re-expression, which will provide the theoretical basis for the clinical practice.
Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/genética , Metilación de ADN/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/genética , Proteínas Supresoras de Tumor/metabolismo , Western Blotting , Carcinoma Hepatocelular/patología , Humanos , Técnicas In Vitro , Neoplasias Hepáticas/patología , Células Tumorales Cultivadas , Proteínas Supresoras de Tumor/genéticaRESUMEN
PURPOSE: To evaluate the therapeutic efficacy and complications of fluoroscopically guided double balloon dilation for treatment of colorectal anastomotic strictures. MATERIALS AND METHODS: Under fluoroscopic guidance, 17 patients with colorectal anastomotic strictures underwent transanal double balloon dilation. Thirteen of 17 strictures were the consequence of surgery for malignant disease and the other four were secondary to surgery for benign disease. Sixteen of 17 patients had difficult or frequent defecation caused by partial obstruction. In the remaining one asymptomatic patient, the stricture was detected by endoscopy and barium enema after total proctocolectomy and a temporary ileostomy for ulcerative colitis. The therapeutic efficacy and complications were evaluated during the follow-up. RESULTS: Seventeen patients underwent double balloon dilation in a single session. The diameter of the first balloon was 20 mm and the second balloon's diameter was 10, 15, or 20 mm. Technical success was achieved in all 17 patients. After balloon dilation, complete (n = 12, 71%) or incomplete (n = 5, 29%) improvement of symptoms was achieved in all patients. Major complications such as perforation or severe hemorrhage did not occur. During the mean follow-up period of 23 months (range, 1-62 months), one patient (6%) developed a recurrent stricture and required a second session of double balloon dilation 6 months after initial balloon dilation. CONCLUSION: Fluoroscopically guided double balloon dilation is an effective and safe method for the treatment of colorectal anastomotic strictures.