Identification and Genetic Analysis of a Factor IX Gene Intron 3 Mutation in a Hemophilia B Pedigree in China.

OBJECTIVE: Hemophilia B is caused by coagulation defects in the factor IX gene located in Xq27.1 on the X chromosome. A wide range of mutations, showing extensive molecular heterogeneity, have been described in hemophilia B patients. Our study was aimed at genetic analysis and prenatal diagnosis of hemophilia B in order to further elucidate the pathogenesis of the hemophilia B pedigree in China. MATERIALS AND METHODS: Polymerase chain reaction amplification and direct sequencing of all the coding regions was conducted in hemophilia B patients and carriers. Prenatal diagnosis of the proband was conducted at 20 weeks. RESULTS: We identified the novel point mutation 10.389 A>G, located upstream of the intron 3 acceptor site in hemophilia B patients. The fetus of the proband's cousin was identified as a carrier. CONCLUSION: Our identification of a novel mutation in the F9 gene associated with hemophilia B provides novel insight into the pathogenesis of this genetically inherited disorder and also represents the basis of prenatal diagnosis.

LncRNA-ATB promotes trastuzumab resistance and invasion-metastasis cascade in breast cancer.

Trastuzumab resistance is leading cause of mortality in HER2-positive breast cancers, and the role of TGF-ß-induced epithelial-mesenchymal transition (EMT) in trastuzumab resistance is well established, but the involvement of lncRNAs in trastuzumab resistance is still unknown. Here, we generated trastuzumab-resistant breast cancer cells with increased invasiveness compared with parental cells, and observed robust epithelial-mesenchymal transition (EMT) and consistently elevated TGF-ß signaling in these cells. We identified long noncoding RNA activated by TGF-ß (lnc-ATB) was the most remarkably upregulated lncRNA in TR SKBR-3 cells and the tissues of TR breast cancer patients. We found that lnc-ATB could promote trastuzumab resistance and invasion-metastasis cascade in breast cancer by competitively biding miR-200c, up-regulating ZEB1 and ZNF-217, and then inducing EMT. In addition, we also found that the high level of lnc-ATB was correlated with trastuzumab resistance of breast cancer patients. Thus, these findings suggest that lncRNA-ATB, a mediator of TGF-ß signaling, could predispose breast cancer patients to EMT and trastuzumab resistance.