Unconjugated
Human Dachshund homologue 1 (DACH1) is a major component of the Retinal Determination Gene Network. Loss of DACH1 expression was found in breast, prostate, lung, endometrial, colorectal and hepatocellular carcinoma. To explore the expression, regulation and function of DACH1 in human esophageal cancer, 11 esophageal cancer cell lines, 10 cases of normal esophageal mucosa, 51 cases of different grades of dysplasia and 104 cases of primary esophageal squamous cancer were employed. Methylation specific PCR, immunohistochemistry, western blot, flow cytometry, small interfering RNAs, colony formation techniques and xenograft mice model were used. We found that DACH1 expression was regulated by promoter region hypermethylation in esophageal cancer cell lines. 18.8% (6 of 32) of grade 1, 42.1% (8 of 19) of grade 2 and grade 3 dysplasia (ED2,3), and 61.5% (64 of 104) of esophageal cancer were methylated, but no methylation was found in 10 cases of normal esophageal mucosa. The methylation was increased in progression tendency during esophageal carcinogenesis (P<0.01). DACH1 methylation was associated with poor differentiation (P<0.05) and late tumor stage (P<0.05). Restoration of DACH1 expression inhibited cell growth and activated TGF-β signaling in KYSE150 and KYSE510 cells. DACH1 suppressed human esophageal cancer cell tumor growth in xenograft mice. In conclusion, DACH1 is frequently methylated in human esophageal cancer and methylation of DACH1 is involved in the early stage of esophageal carcinogenesis. DACH1 expression is regulated by promoter region hypermethylation. DACH1 suppresses esophageal cancer growth by activating TGF-β signaling.
This study was designed to investigate the effect of recombinant sTGFβ1RII and sIL13Rα2 receptor proteins on schistosomiasis japonica, hepatic fibrosis and the expression of SMAD3 and STAT6. The proteins sTGFβ1RII and sIL13Rα2 were expressed in Escherichiacoli, purified using affinity chromatography and characterized by Western blotting. Female BALB/C mice (48) were randomly divided into eight groups and infected with Schistosoma japonicum. Five weeks after infection, test groups were injected with the recombinant proteins at different doses. Eight weeks after infection, lung and hepatic tissue samples were obtained and stained with hematoxylin and eosin (HE) and Masson's trichrome. Immunohistochemical staining was used to detect the expression of SMAD3 and STAT6. The recombinant proteins sTGFβ1RII and sIL13Rα2 were successfully expressed, purified, and characterized. The granuloma area, hepatic hydroxyproline (HYP) level and hepatic fibrosis of the protein therapeutic groups were significantly smaller than those of the positive control group (P<0.01). Treatment with sTGFβ1RII was more effective when the protein was administered for 4weeks rather than 2 (P<0.01). Hepatic fibrosis in the groups using a low dose of protein sTGFβ1 was lower that of the combination group (P<0.05). The expression level of STAT6 was significantly lower in groups treated with sIL13Rα2 than in groups not treated with the protein (P<0.01). The recombinant proteins TGFβ1RII and sIL13Rα2 were able to decrease granuloma area and hepatic fibrosis in schistosomiasis japonica, and also reduced the expression of the signal transduction proteins SMAD3 and STAT6. The proteins were more effective when used in combination than when applied singly.