Objective Stathmin, a microtubule-destabilizing protein , has high expression in esophageal squamous cell carci-noma(ESCC), while taxol is a common chemotherapy microtubule-targeted drug for esophageal cancer .This study aimed to investigate the impact of stathmin expression and its influence on taxol sensitivity in ESCC . Methods We established 2 cell models with ST-MN1 gene overexpression in KYSE 510 and KYSE 170 cell lines, including KYSE 510-Stathmin, KYSE 170-Stathmin, KYSE 510-Control and KYSE 170-Control.MTT assay and colony formation were applied to compare the taxol sensitivity between experimental group and control group .Flow cytometry was used to measure the apoptosis of KYSE 510-Stathmin and KYSE 510-Control after taxol treatment.Western blot was used to test the changes of related factors to apoptosis and autophagy . Results ①Stathmin protein ex-pressions in KYSE 510-Stathmin and KYSE 170-Stathmin cells were higher than those of control cells (P<0.01).② The percentages of inhibition were significantly decreased in KYSE 510-Stathmin and KYSE 170-Stathmin cells 24 h after 50, 100,250 nmol/L taxol treat-ment compared with KYSE 510-Stathmin cells(P <0.01).③The percentages of inhibition were significantly reduced in KYSE 510-Stathmin and KYSE 170-Stathmin cells after 250 nM taxol treatment for 24, 48, 60 h (P<0.01).④After taxol treatment,the number of colony formation in KYSE 510-Stathmin cells was higher com-pared with KYSE 510-Control cells (P<0.01).⑤The percentage of cell apoptosis in KYSE 510-Stathmin was significantly lower than that of KYSE 510-Control cells by flow cytometry (11.90%±0.78%vs 29.63%±3.26%, P<0.05).Western blot showed the ap-optosis of associated proteins such as the activation of Caspase 8 and Caspas9. Conclusion The result indicates that overexpression of stathmin inhibits taxol sensitivity in ESCC cell lines .

Objective: To evaluate the effect of overexpression of the autophagy marker gene Beclin1 on biological behaviors of SK-MEL-2 human malignant melanoma cells. Methods: Western blot analysis was performed to determine the protein expression of Beclin1 in melanoma cell lines A375 and SK-MEL-2. SK-MEL-2 cells with low Beclin1 protein expression were selected as research objects, and divided into 3 groups: blank group receiving no treatment, negative control group transfected with pcDNA.3.1/myc-His (-) A, and experimental group transfected with pcDNA3.1-Beclin1 plasmid. After 2-week culture, cell counting kit-8 (CCK-8) assay was conducted to evaluate the effect of Beclin1 on cell proliferation at 24, 48 and 72 hours, and Transwell assay and wound-healing assay were performed to assess the effect of Beclin1 overexpression on the invasion and migration abilities of SK-MEL-2 cells. Repeated measures analysis of variance and completely randomized analysis of variance were used to analyze differences in indices among groups, and least significant difference (LSD) -t test was used for multiple comparisons. Results: The protein expression of Beclin1 was significantly lower in the SK-MEL-2 cells (0.037 ± 0.010) than in the A375 cells (0.670 ± 0.150, F = 46.62, P<0.05) . The experimental group showed significantly increased protein expression of Beclin1 (0.32 ± 0.04) compared with the negative control group (0.06 ± 0.02, P < 0.05) and blank group (0.07 ± 0.02, P < 0.05) . CCK-8 assay revealed a significant difference in the cell proliferation rate among different groups and different time points (F = 1 077.36, 4 903.04 respectively, both P<0.05) , and there was a significant interaction between the transfection treatment and time (F= 205.20, P<0.05) . Transwell assay showed that the number of SK-MEL-2 cells crossing the chamber per high-power field (× 200) after 24-hour treatment was significantly lower in the experimental group (18.67 ± 1.19) than in the negative control group (87.89 ± 6.05, P<0.05) and blank group (86.78 ± 5.93, P<0.05) . In the wound-healing assay, the cell migration distance was significantly shorter in the experimental group than in the blank group and negative control group at 24 and 48 hours (all P < 0.05) . Conclusion Beclin1 overexpression can markedly inhibit the proliferation, invasion and migration of SK-MEL-2 cells.