High Expression of ABL2 Suppresses Apoptosis in Gastric Cancer
DIGESTIVE DISEASES AND SCIENCES
Authors: Liu, Yun; Shao, Chen; Zhu, Linqi; Jiang, Sihong; Li, Guanlin; Zhang, Wei; Lin, Yajing; Ni, Ying; Cao, Hui; Shao, Shihe
Abstract
Background Diseases associated with Abelson-related gene (also called ABL2) include leukemia; furthermore, previous researches have studied the expressions and functions of ABL2 in different types of malignancies and found that it plays an important role in almost all kinds of cancers. Aims Nevertheless, the mechanism of ABL2 in gastric cancer (GC) remains vague. Methods In the present study, the level of ABL2 in human GC tissues was detected by immunohistochemistry. Also, the GC cell lines MGC-803 and BGC-823 were selected to stably knock down and overexpress the level of ABL2 by corresponding lentiviral vectors. Puromycin was used to maintain the stable low expression of ABL2 MGC-803 cells compared with control cells; what is more, the high expression of ABL2 BGC-823 cells was also obtained. Based on it, we detected the proteins associated with apoptosis, such as Bcl-2 family and caspase family by western blotting. Results The most appropriate concentration of puromycin to kill GC cells is 1 mu g/mL; then, we obtained the corresponding stable cell lines. Furthermore, we found that high level of ABL2 in BGC-823 cells increased the expression of Bcl-XL, total PARP, and caspase3, while decreased the level of cleaved caspase3 and cleaved caspase9. Consistent results are received in MGC-803 cells. In addition, ABL2 overexpression led to the protein related with Ras/Erk and PI3K/AKT signaling pathway increased; also, we found that the major proteins play a significant role in it. Conclusion All the data showed that high expression of ABL2 suppresses apoptosis through Ras/Erk and PI3K/AKT signaling pathway in GC cell lines.
Abl2/Arg Controls Dendritic Spine and Dendrite Arbor Stability via Distinct Cytoskeletal Control Pathways
JOURNAL OF NEUROSCIENCE
Authors: Lin, Yu-Chih; Yeckel, Mark F.; Koleske, Anthony J.
Abstract
Rho family GTPases coordinate cytoskeletal rearrangements in neurons, and mutations in their regulators are associated with mental retardation and other neurodevelopmental disorders (Billuart et al., 1998; Kutsche et al., 2000; Newey et al., 2005; Benarroch, 2007). Chromosomal microdeletions encompassing p190RhoGAP or its upstream regulator, the Abl2/Arg tyrosine kinase, have been observed in cases of mental retardation associated with developmental defects (Scarbrough et al., 1988; James et al., 1996; Takano et al., 1997; Chaabouni et al., 2006; Leal et al., 2009). Genetic knock-out of Arg in mice leads to synapse, dendritic spine, and dendrite arbor loss accompanied by behavioral deficits (Moresco et al., 2005; Sfakianos et al., 2007). To elucidate the cell-autonomous mechanisms by which Arg regulates neuronal stability, we knocked down Arg in mouse hippocampal neuronal cultures. We find that Arg knockdown significantly destabilizes dendrite arbors and reduces dendritic spine density by compromising dendritic spine stability. Inhibiting RhoA prevents dendrite arbor loss following Arg knockdown in neurons, but does not block spine loss. Interestingly, Arg-deficient neurons exhibit increased miniature EPSC amplitudes, and their remaining spines exhibit larger heads deficient in the actin stabilizing protein cortactin. Spine destabilization in Arg knockdown neurons is prevented by blocking NMDA receptor-dependent relocalization of cortactin from spines, or by forcing cortactin into spines via fusion to an actin-binding region of Arg. Thus, Arg employs distinct mechanisms to selectively regulate spine and dendrite stability: Arg dampens activity-dependent disruption of cortactin localization to stabilize spines and attenuates Rho activity to stabilize dendrite arbors.