Establishment of a low-tumorigenic MDCK cell line and study of differential molecular networks.

Influenza is an acute respiratory infection caused by the influenza virus, and vaccination against influenza is considered the best way to prevent the onset and spread. MDCK (Madin-Darby canine kidney) cells are typically used to isolate the influenza virus, however, their high tumorigenicity is the main controversy in the production of influenza vaccines. Here, MDCK-C09 and MDCK-C35 monoclonal cell lines were established, which were proven to be low in tumorigenicity. RNA-seq of MDCK-C09, MDCK-C35, and MDCK-W73 cells was performed to investigate the putative tumorigenicity mechanisms. Tumor-related molecular interaction analysis of the differentially expressed genes indicates that hub genes, such as CUL3 and EGFR, may play essential roles in tumorigenicity differences between MDCK-C (MDCK-C09 and MDCK-C35) and MDCK-W (MDCK-W73) cells. Moreover, the analysis of cell proliferation regulation-associated molecular interaction shows that downregulated JUN and MYC, for instance, mediate increased proliferation of these cells. The present study provides a new low-tumorigenic MDCK cell line and describes the potential molecular mechanism for the low tumorigenicity and high proliferation rate.

[Cooperative Protection of American Ginseng Seedlings by Applying Imidacloprid, Fludioxonil and Phoxim].

OBJECTIVE: To screen out an effective method of controlling pests on American ginseng(Panax quinquefolium). METHODS: The germinating seeds of the plant from two growers in Liuba County,Shaanxi Province,were collected and potted in pest-residing sandy soils indoors. Four pesticides (imidacloprid wettable powders, fludioxonil flowable concentrate for seed coating, chlorpyrifos granules and Pyrifos ∙ phoxim granules) in different modes and doses were applied, and their effects were assayed. RESULTS: Pests were largely enchytraeid(Enchytraeus bulbosus), root mite (Rhizoglyphus robini) and two root rot fungi(Cylindrocarpon destructans and Phytophthora cactorum), which could be transmitted by both seed and soil. The treatment of dressing or soaking seeds in mixed solution of imidacloprid 25WP and fludioxonil 2.5SD plus blending the pest-residing sandy soil with chlorpyrifos ∙ phoxim 5G displayed significant effects of both controlling pests and keeping stand of seedlings(P <0. 05); whereas each of the three pesticides exhibited a middle-class effect when applied alone, and chlorpyrifos l0G showed little effect when applied singly. CONCLUSION: The combined approach of seed- and soil-tteatments is able to efficiently reduce damages caused by seed- and soil-born pests, and become one optimal measure protecting seedlings,and is thus suggested to demonstrate and extend in the pests' infestation areas.