cDNA cloning of a novel lectin that induce cell apoptosis from Artocarpus hypargyreus / 中国天然药物

We isolated a novel lectin (AHL) from Artocarpus hypargyreusHance and showed its immunomodulatory activities. In this study, the amino acid sequence of AHL was determined by cDNA sequencing. AHL cDNA (875bp) contains a 456-bp open reading frame (ORF), which encodes a protein with 151 amino acids. AHL is a new member of jacalin-related lectin family (JRLs), which share high sequence similarities to KM+ and Morniga M, and contain the conserved carbohydrate binding domains. The antitumor activity of AHL was also explored using Jurkat T cell lines. AHL exhibits a strong binding affinity to cell membrane, which can be effectively inhibited by methyl-α-D-galactose. AHL inhibits cell proliferation in a time- and dose-dependent manner through apoptosis, evidenced by morphological changes, phosphatidylserine externalization, poly ADP-ribose polymerase (PARP) cleavage, Bad and Bax up-regulation, and caspase-3 activation. We further showed that the activation of ERK and p38 signaling pathways is involved for the pro-apoptotic effect of AHL.

Expression and mutations of PIK3CA gene in hepatocellular carcinomas / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the expression and mutation of PIK3CA gene in hepatocellular carcinomas (HCC).</p><p><b>METHODS</b>HCC samples and the corresponding adjacent tissues were collected from the surgical patients with pathologically verified diagnosis. The exons 1, 9 and 20 of PIK3CA gene were detected by PCR-SSCP and DNA sequencing. Immnohistochemistry was employed to test the expression of PIK3CA gene in these samples.</p><p><b>RESULTS</b>No mutation was found in exons 1, 9 or 20 of PIK3CA gene in the HCC tissue and the adjacent tissues by PCR-SSCP and DNA sequencing, while abnormal superimposed peaks were found on the sequence map of exon 9 in 25 cases of HCC tissue. Immunohistochemistry showed that expression of PIK3CA was higher in the HCC tissue than in the corresponding adjacent tissue (50.81% vs 14.75%).</p><p><b>CONCLUSION</b>PIK3CA gene mutation may exist in HCC in Guangxi, which can be associated with the development of HCC, but the ratio of hotspot mutations is low.</p>