This paper deals with the development of Paragonimus westermani (Kerbert, 1878) in mice inoculated with metacercariae or stunted adolescariae. In metacercaria-inoculated mice, all worms were stunted all the time, but when the stunted worms were orally transferred Into mice, some (8.4%) grew so fast that their rudimentory reproductive organs appeared and their length was over 3 times that of stunted worms 3 weeks post inoculation; while 91.6% of the recovered adolescariae were still stunted and morphologically similar to excysted metacercaiae. When the stunted worms were repeatedly transferred through mice by oral route 8.2-10.1% of the recovered worms developed quickly, while the remainder was still stunted (Table 1).After 3 transfers in mice, the stunted worms were still able to infect dogs orally and reach maturity (Table 2).On the basis of the study, it is postulated that cannibalism and preying among wild rats would enable P. westermani to be transferred among rodent paratenic hosts.

OBJECTIVE: To explore the role of DNMT3B in regulating the proliferation and invasion of hepatocellular carcinoma (HCC) cells. METHODS: We collected the tumor tissues and adjacent tissues from a total of 175 patients with HCC diagnosed in the Second Affiliated Hospital of Chongqing Medical University between May, 2008 and May, 2013 to prepare the tissue microarrays. The association of the expression of DNMT3B with the prognosis and the tumor-free survival and tumor-specific survival rates of the patients was analyzed. Univariate and multivariate Cox regression analyses were used to analyze the effect of DNMT3B expression on the prognosis of HCC. We used RNA interference technique to knock down the expression of DNMT3B in Huh-7 hepatoma cells and observed the changes in cell proliferation using CCK-8 assay and EDU staining and in cell migration and invasion ability using Transwell assay. RESULTS: The positive rates of DNMT3B was significantly higher in HCC tissues than in paired adjacent tissues (67.4% 41.1%, =0.015). A high DNMT3B expression in HCC was significantly associated with the tumor size (=0.001), vascular invasion (=0.004), and intrahepatic metastasis (=0.018). The patients with high DNMT3B expressions had significantly lower tumor-free and tumor-specific survival rates than those with low DNMT3B expressions ( < 0.005). In Huh-7 cells, silencing DNMT3B significantly inhibited the cell proliferation and inhibited cell migration and invasion. Western blotting showed that silencing DNMT3B obviously increased LATS1 expression, decreased the expression of YAP1, and activated Hippo signaling pathway. Methylation-specific PCR showed that the methylation level of LATS1 was decreased in the cells with DNMT3B silencing. CONCLUSIONS The expression level of DNMT3B is significantly higher HCC tissues than in the adjacent tissues, and the high expression of DNMT3B is closely related to the low survival rate of the patients. Silencing DNMT3B inhibits the proliferation, migration and invasion of HCC cells. DNMT3B promotes the progression of HCC primarily by enhancing the expression of YAP1 through methylation of LATS1 and inhibition of its expression, which inhibits the anti-cancer effect of Hippo signaling pathway.
Carcinoma, Hepatocellular ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Liver Neoplasms ; Protein-Serine-Threonine Kinases ; Signal Transduction