ABSTRACT
Objective:To study the effect of extract of livistona chinensis on the proliferation and apoptosis of bladder cancer cells and the related mechanism.Methods:T24 cells were cultured in medium with the final concentration of 0, 25, 50 and 100 mg/L livistona chinensis extract, respectively. And then they were divided into control group and low, medium and high dose groups. The cell survival rate was detected by cell counting kit 8 (CCK-8). Colony formation assay was used to detect the number of cell clones. Apoptosis was detected by flow cytometry. Western blot was used to detect the expression of related proteins. The Syk overexpression vector plasmid and its negative control were transfected into T24 cells. After transfection, the cells were treated with 100 mg/L livistona chinensis. The cell survival rate, colony formation number and apoptosis rate were detected by the above method. The bladder cancer model nude mice were treated with different concentrations of livistona chinensis extract. Under the microscope, the expression of protein was detected by immunohistochemical staining of bladder tissue.Results:Compared with the control group, the survival rate of T24 cells in the low, medium and high dose livistona chinensis extract groups were significantly decreased [(88.50±3.65)%, (70.58±2.47)%, (48.90±2.37)% vs. (98. 25±4.26)%], and the number of clone formation decreased significantly [(101. 33±3.40), (84.00±2.94), (60.00±2.16) vs. (121.33±4.64) ], and the apoptosis rate was significantly increased [(11.45± 0.59)%, (17.71±0.64)%, (21.33±0.83)% vs. (7. 86±0.43)%]. The expression level of Ki-67 protein was significantly decreased, while the expression levels of Caspase3 and Syk protein were significantly increased in a concentration dependent manner ( P < 0.05). The cell survival rate of pcDNA3.1-Syk group was significantly lower than that of pcDNA3.1 group [(63.87±2.53)% vs. (98. 45±3.54)%], the number of clone formation decreased significantly [(74. 33±2.87) vs. (121.33±3.68)], and the apoptosis rate was significantly increased [(18.39±0.63)% vs. (7.89± 0.45)%] (all P<0.05). The cell survival rate in the high-dose group of livistona chinensis+ pcDNA3.1-Syk was significantly lower than that in the high-dose group of livistona chinenisi+ pcDNA3.1 group [ (29.80±1.63)% vs.(49.33±2.76)% ], the number of clone formation decreased significantly [(33.00±2.94) vs. (59.67±3.30) ], and the apoptosis rate was significantly increased [(26.93±0.68)% vs. (21.25±0.78)% ]( P<0.05). The experimental results of nude mice of bladder cancer model showed that the tumor volume of transplanted bladder cancer nude mice in the control group and the low, medium, and high dose livistona chinensis extract groups were (1 209.75±64.37), (1 006.31±40.49), (530.58±42.87), (267.58±16.73)mm 3, respectively, the weight of the transplanted tumor were (0.36±0.08), (0.30±0.04), (0.26±0.03), (0.18±0.06)g, and the differences between the two groups were statistically significant ( P <0.05). Immunohistochemical staining results showed that the expression of Sky and Caspase3 was increased and the expression of Ki-67 was decreased in the middle and high dose groups compared with that in the control group. Conclusion:Extract of livistona chinensis can inhibit the proliferation and promote apoptosis of bladder cancer cells by up regulating Syk expression.
ABSTRACT
BACKGROUND:Silk fibroin, as a kind of high-performance biomaterial, has been widely used to construct scaffolds in bone tissue engineering. However, whether silk fibroin itself holds osteoinductive ability has not been reported yet. OBJECTIVE:To investigate the impact of different concentrations of silk fibroin solution on the proliferation and differentiation of rat bone marrow mesenchymal stem cel s (BMSCs) in vitro. METHODS:Silk fibroin and BMSCs were respectively isolated from silkworm cocoon and rat tibia, and were identified. Then, BMSCs were cultured in different concentrations of silk fibroin solution (0.01%, 0.05%and 0.1%), and the cell proliferation and the alkaline phosphatase activity were detected at different time points. RESULTS AND CONCLUSION:FTIR spectra of the sample extracted from silkworm cocoon showed distinct absorption peaks at 1 653 (amide I), 1 530.5 (amide II) and 1 212.3 cm-1 (amide III), which could be confirmed to be silk fibroin. Thus generated BMSCs showed long fusiform or astral morphology, positive for representative markers (CD29, CD44 and CD90) relating to mesenchymal stem cells, and could differentiate into osteocytes, chondrocytes and adipocytes under specific induction conditions, which further confirmed the extracted cells were BMSCs. Compared with the control group (without silk fibroin), 0.05% silk fibroin not only significantly promoted the cell adhesion, migration and proliferation, but also enhanced the alkaline phosphatase activity (P<0.01). With the increasing of the silk fibroin concentrations, the osteodifferentiation capacity of the BMSCs was progressively improved within the range of 0-0.05%and then declined at 0.01%of silk fibroin solutions. These results suggest that silk fibroin can promote osteogenesis, thus providing scientific evidence for developing silk fibroin-based tissue-engineered scaffolds.