[Effects of Dnmt1 and Dnmt3b in mucoepidermoid carcinoma of salivary glands].

PURPOSE: To investigate the effects of DNA methyltransferase in mucoepidermoid carcinoma of human salivary glands tissues. METHODS: Forty-three samples from mucoepidermoid carcinoma of salivary glands and 17 normal salivary gland tissues were collected from January 2010 to September 2013. Immunohistochemistry and Western blot were used to detect the expression of Dnmt1 and Dnmt3b in normal tissues and specimen of mucoepidermoid carcinoma of salivary glands. The data were analysed with SPSS 22.0 software package. RESULTS: The positive expression rate of Dnmt1 in mucoepidermoid carcinoma tissue was 37.21%, and that in normal salivary gland tissues was 17.65%, there was no significant difference between them; the positive expression rate of Dnmt3b in mucoepidermoid carcinoma tissue was 83.72%, which was significantly higher than that in normal salivary gland tissue (11.76%, P<0.01). However, there was no significant correlation between high expression of Dnmt1 and Dnmt3b and clinicopathological parameters. CONCLUSIONS: Dnmt3b may play a role in the tumorigenesis of mucoepidermoid carcinoma in salivary glands.

[Molecular cloning of the DNA sequence of activin beta A subunit gene mature peptides from panda and related species and its application in the research of phylogeny and taxonomy].

Activin, which is included in the transforming growth factor-beta (TGF beta) superfamily of proteins and receptors, is known to have broad-ranging effects in the creatures. The mature peptide of beta A subunit of this gene, one of the most highly conserved sequence, can elevate the basal secretion of follicle-stimulating hormone (FSH) in the pituitary and FSH is pivotal to organism's reproduction. Reproduction block is one of the main reasons which cause giant panda to extinct. The sequence of Activin beta A subunit gene mature peptides has been successfully amplified from giant panda, red panda and malayan sun bear's genomic DNA by using polymerase chain reaction (PCR) with a pair of degenerate primers. The PCR products were cloned into the vector pBlueScript+ of Esherichia coli. Sequence analysis of Activin beta A subunit gene mature peptides shows that the length of this gene segment is the same (359 bp) and there is no intron in all three species. The sequence encodes a peptide of 119 amino acid residues. The homology comparison demonstrates 93.9% DNA homology and 99% homology in amino acid among these three species. Both GenBank blast search result and restriction enzyme map reveal that the sequences of Activin beta A subunit gene mature peptides of different species are highly conserved during the evolution process. Phylogeny analysis is performed with PHYLIP software package. A consistent phylogeny tree has been drawn with three different methods. The software analysis outcome accords with the academic view that giant panda has a closer relationship to the malayan sun bear than the red panda. Giant panda should be grouped into the bear family (Uersidae) with the malayan sun bear. As to the red panda, it would be better that this animal be grouped into the unique family (red panda family) because of great difference between the red panda and the bears (Uersidae).