• PIK3CA and AKT2 mutations of gastric cancer in China

    分类: 生物学 >> 遗传学 提交时间: 2018-03-16

    摘要:Mutations in PI3K and/or AKT have been reported in a variety of cancers. This indicates that the two pathways interact to cause cancer. We have therefore investigated their roles in gastric cancer (GC) in China. In our study, exons 9, 18 and 20 of PIK3CA gene and exons 6~14 of AKT2 gene were screened in 10 GC cell lines and 100 advanced primary GC together with matched normal tissues. Denaturing high performance liquid chromatography (DHPLC) and DNA sequencing were used to analyze the mutations in the two genes. Two point mutations in the PIK3CA gene were identified in 4 of 10 GC cell lines and in 4 of 100 GC primary tumors. Two polymorphisms in AKT2 were detected in 19 of 100 GC primary tumors. One point mutation in AKT2 was detected in 1 of 10 GC cell lines and 3 of 100 GC primary tumors, and no hot spot variation was detected. Our results indicate that PIK3CA and AKT2 mutations are found in GC, although not a common event, therefore they might still play an important role in mediating kinase activities towards gastric carcinogenesis.

  • Effects of tetracyclines on bone: an ambiguous question needs to be clarified

    分类: 生物学 >> 生物化学 提交时间: 2018-03-15

    摘要:Tetracyclines have been widely used in bone histomorphometry to label new bone formation and apposition rate. However, most studies of tetracyclines have also shown their strong inhibitory action on osteoclasts and their effects on osteoblast activities as well. To even obtain the in-depth understanding on this issue, we have reviewed related studies in “Pubmed” by searching the keywords “tetracyclines and osteoclast”, “tetracyclines and osteoblast”, which retrieved 115 and 159 related documents, respectively. Among these papers, some described the application of tetracyclines as fluorescent marker in bone histomorphometry, while others discussed their role in protection of bone metabolism partly through inhibiting osteoclastogenesis or bone resorption and through enhancing osteogenesis. Based on the above mentioned, it seems that tetracyclines used as bone labeling markers may affect the results of bone histomorphometry to some extent. To even confirm the effect of tetracyclines on bone cells (osteoblast, osteoclast) and in vivo bone remodeling, related research work has been performed in our research team which indicated quite different results in vivo and in vitro. Therefore, the influence of tetracyclines on bone may differ in terms of different conditions which need to be further elucidated as well.