The effect of downregulation of Stathmin gene on biological behaviors of U373 and U87-MG glioblastoma cells

BACKGROUND: Stathmin as a critical protein involved in microtubule polymerization, is necessary for survival of cancer cells. However, extremely little is known about Stathmin in glioblastoma. So, this study was designed to elucidate the function of Stathmin gene in the tumorigenesis and progression of glioblastoma cells. METHOD: The lentiviral interference vector pLV3-si-Stathmin targeting Stathmin gene and the control vector pLV3-NC were established for the co-transfection of 293T cells together with the helper plasmids. Viral titer was determined via limiting dilution assay. Then pLV3-si-Stathmin and pLV3-NC were stably co-transfected into U373 and U87-MG glioblastoma cells. Expression levels of Stathmin protein in each group were determined by using Western Blot, and the proliferation and migration ability of the cells with downregulated Stathmin were evaluated through CCK8 assay and transwell invasion assay, respectively. Cell cycles and cell apoptosis were detected with flow cytometry. Finally, the effect of Stathmin in tumor formation was determined in nude mice. RESULT: DNA sequencing and viral titer assay indicated that the lentiviral interference vector was successfully established with a viral titer of 4 × 108 TU/ml. According to the results from Western Blotting, Stathmin protein expression level decreased significantly in the U373 and U87-MG cells after transfected with pLV3-si-Stathmin, respectively, compared with those transfected with pLV3-NC. In glioblastoma cells, the cell proliferation and migration were greatly inhibited after the downregulation of Stathmin protein. Flow cytometry showed that much more cells were arrested in G2/M phasein Stathmin downregulated group, compared with the non-transfection group and NC group. But Stathmin downregulation did not induce significant cell apoptosis. Tumor formation assay in nude mice showed that tumor formation was delayed after Stathmin downregulation, with a reduction in both tumor formation rate and tumor growth velocity. CONCLUSION: Stathmin downregulation affected the biological behaviors of U373 and U87-MG glioblastoma cells, inhibiting the proliferation and migration of tumor cells. Stathmin gene may serve as a potential target in gene therapy for glioblastoma.

Molecular cloning and expression analysis of evolutionarily conserved stathmin from Gekko japonicus spinal cord.

The cDNA encoding stathmin is identified from the brain and spinal cord cDNA library of Gekko japonicus. It contains a 450 bp open-reading-frame, corresponding to a deduced protein of 149 amino acids. At amino acid level, gecko stathmin shares more than 76.4% identities with vertebrate stathmins, and especially, it shares 100% identity with human stathmin, suggesting that the selective pressure must have been extremely high for the conservation of stathmin during the vertebrates including reptile evolution. Reverse transcriptase polymerase chain reaction (RT-PCR) shows that gecko stathmin is ubiquitously expressed in all tissues examined. In situ hybridization reveals that stathmin transcript mainly appear in the gray matter of spinal cord. The change of stathmin expression in spinal cord after tail amputation is examined by semi-quantitative RT-PCR. Stathmin expression increases at 1 day and 3 day after amputation and decreases to the control level at 1 week. However, the expression level increases again at 2 weeks. These suggest that stathmin may be associated with the immune protection of the injury, as well as in the regeneration of spinal cord.

Effect of Stathmin decoy-oligodeoxynucleotides on the proliferation and differentiation of precartilainous stem cells / 华中科技大学学报（医学）（英德文版）

By using decoy-oligodeoxynucleotides (decoy-ODNS) technique, the effects of Stathmin gene on the proliferation and differentiation of in vitro cultured precartilainous stem cells (PSCs) were investigated. The Stathmin decoy-ODNs were transfected into PSCs in rats by using gene transfection technique. Under the induction of cortisol (1 micromol/L), electrophoretic mobility shift assay was used the inhibitory effects of decoy-ODNS on Stathmin gene. MTT and cytometry were used to test the cell proliferation. The expression of collagen II and V and Stathmin protein was detected by using Western blot. The results showed that Stathmin decoy-ODNs inhibited the Stathmin activity in a dose-dependent manner. When the concentration of decoy-ODNs was 10 times of standard concentration, the proliferation of PSCs was obviously suppressed and the differentiation happened. Compared to the control group, the difference was significant (P<0.05). It was concluded that decoy-ODNs could inhibit the proliferation and promote the differentiation of PSCs by antagonizing Stathmin activity.