[Effects of Paclitaxel and Quizartinib Alone and in Combination on AML Cell Line MV4-11 and Its STAT5 Signal Pathway].

OBJECTIVE: To investigate the effects of paclitaxel, quizartinib and their combination on proliferation, apoptosis and FLT3/STAT5 pathway of human leukemia cell line MV4-11 (FLT3-ITD+). METHODS: MV4-11 cells were treated with paclitaxel and quizartinib at different concentrations for 24 h, 48 h and 72 h, respectively, and then the two drugs were combined at 48 h to compare the inhibition of proliferation, the apoptosis rate was detected by flow cytometry, the expression of FLT3 and STAT5 mRNA was determined by fluorescence quantitative PCR, and the protein expression of FLT3, p-FLT3, STAT5 and p-STAT5 was determined by Western blot. RESULTS: Different combination groups of paclitaxel and quizartinib had synergistic inhibitory effect. The cell survival rate in the combination group was significantly lower than that in the single drug group (P<0.05). The cell apoptosis rate in the combination group was significantly higher than that in the single drug group (P<0.001). The expression of FLT3 mRNA in combination group was significantly higher than that in two single drugs (P<0.01). The expression of STAT5 mRNA in combination group was significantly higher than that in quizartinib group (P<0.001); increased compared with paclitaxel group, but there was no statistical significance. The expression level of p-FLT3、p-STAT5 protein in the combination group was significantly lower than that in the single drug group (P<0.05, P<0.05). CONCLUSION: Paclitaxel combined with quizartinib can synergistically inhibit the proliferation of MV4-11 cell line and promote the apoptosis of MV4-11 cell line by inhibiting the activity of FLT3/STAT5 pathway.

[Exploring the Mechanism of Paclitaxel Inhibiting T-cell Lymphoma based on High-throughput Sequencing and Public Databases].

OBJECTIVE: To analyze gene expression profile of T cell lymphoma Jurkat cell line treated with paclitaxel by computational biology based on next generation sequencing and to explore the possible molecular mechanism of paclitaxel resistance to T cell lymphoma at gene level. METHODS: IC50 of paclitaxel on Jurkat cell line was determined by CCK-8 assay. Gene expression profile of Jurkat cells treated with paclitaxel was acquired by next generation sequencing technology. Gene microarray data related to human T cell lymphoma were screened from Gene Expression Omnibus (GEO) database (including 720 cases of T cell lymphoma and 153 cases of normal tissues). Combined with the sequencing data, differential expression genes (DEGs) were intersected and screened. DAVID database was used for enrichment analysis of GO function and KEGG pathway to determine and visualize functional entries of DEGs, and protein-protein interactions network of DEGs was drawn. The levels of gene expression were detected and verified by RT-qPCR. RESULTS: CCK-8 results showed that the proliferation of Jurkat cells was inhibited by paclitaxel depended on the concentration apparently. Treated by paclitaxel for 48 h, P<0.05 and |log2(FC)|≥1 were used as filter criteria on the results of RNA Sequencing (RNA-Seq) and GeoChip, 351 DEGs were found from Jurkat cells, including 323 up-regulated genes and 28 down-regulated genes. The GO functional annotation and KEGG pathway enrichment analysis showed that the role of paclitaxel was mainly concentrated in protein heterodimerization activity, nucleosome assembly and transcriptional dysregulation in cancer, etc. The results of RT-qPCR were consistent with those of the sequencing analysis, which verified the reliability of this sequencing. CONCLUSION: Paclitaxel can affect the proliferation and apoptosis of T-cell lymphoma by up-regulating JUN gene, orphan nuclear receptor NR4A family genes and histone family genes.

[Effect of Mangiferin on Proliferation of FLT3-ITD Mutation Positive Acute Myeloid Leukemia Cell MV4-11 and Its Mechanism].

OBJECTIVE: To investigate the effects of mangiferin on proliferation, apoptosis and cycle of FLT3-ITD mutation-positive acute myeloid leukemia cells and its mechanism. METHODS: The effects of different concentration of mangiferin on proliferation of MV4-11 cells were detected by CCK8 method. Apoptosis, cell cycle and FLT3 transmembrane protein expression were detected by flow cytometry. FLT3 mRNA expression was detected by real-time fluorescent quantitative polymerase chain reaction (PCR) . RESULTS: Mangiferin obviously inhibited MV4-11 proliferation in a concentration and time dependent manner (48 h，r=0.922；72 h，r=0.959；96 h，r=0.973). The ratio of G0/G1 phase in cell cycle increased with the enhancement of concentration of mangiferin in MV4-11 cells for 48 h, and the ratio of S phase decreased with enhasment of concentration. The increase of apoptosis was more obvious. The expression of FLT3 transmembrane protein significantly decreased after the actior of IC50 concentration of mangiferin in MV4-11 cells for 48 h. The results of qRT-PCR showed that the expression of FLT3 mRNA significantly decreased after treatment of MN4-11 cells with mangiferin (P＜0.05). CONCLUSION: Mangiferin inhibits MV4-11 cell proliferation, arrests cell cycle progression and promotes apoptosis, which may be related with the inhibition of FLT3 activity by mangiferin and the subsequent signaling pathways involved in apoptosis and proliferation of cells.

Complete mitochondrial genome of the Xiangjiang barbel chub Squaliobarbus curriculus: comparative analysis of the genetic variation associated with geographical population.

The barbel chub (Squaliobarbus curriculus), a kind of small commercial fish, is widespread in China. In this study, we sequenced the mitochondrial genome of the barbel chub from the Xiangjiang River. The total length of the mitochondrial genome is 16,619 bp, with the base composition of 31.19% A, 25.01% T, 27.68% C, and 16.12% G. The organization and arrangement of these genes are the same as that found in the teleosts, including 2 ribosomal RNA genes, 13 protein-coding genes, 22 transfer RNA genes, and a major noncoding control region (D-loop region). Compared with the S. curriculus collected from Jiangsu province, there were 29 mutation sites in the mitogenome sequence of Xiangjiang S. curriculus. All the mutation sites were transitions and mainly occurred in protein-coding genes (21/29), two mutation sites occurred in transfer RNA, two occurred in ribosomal RNA, and four occurred in D-loop region. Among the 21 mutation sites in protein-coding genes, 6 mutation sites resulted in amino acid mutation in ND2, ATPase6, COX3, ND4, and Cytb genes, while the others were synonymous substitutions. These results indicated that there was genetic variation in different geographical populations of S. curriculus.

[Effects of mangiferin on cell cycle status and CDC2/Cyclin B1 expression of HL-60 cells].

OBJECTIVE: To study the effects of mangiferin on cell cycle status and CDC2/Cyclin B1 expression in HL-60 cells, and its molecular mechanism for treating leukemia. METHODS: The effect of Mangiferin on HL-60 cells proliferation was determined by MTT assay; The change of cell cycle status in HL-60 cells treated with mangiferin was performed by the flow cytometry; The expressions of CDC2 mRNA and Cyclin B1 mRNA were detected by semiquantitative RT-PCR. RESULTS: The growth inhibition effects of mangiferin in HL-60 cells were enhanced as the mangiferin concentration increased and exposure time prolonged; HL-60 cells in G2/M phase increased in a dose-dependent way 24 hours after mangiferin administration, indicating G2/M phase blockage; the expressions of CDC2 mRNA and Cyclin B1 mRNA enhanced in a dose-dependent way and came to the peak at 80 micromol/L mangiferin. CONCLUSION: Mangiferin can inhibit the proliferation of HL-60, block the cell cycle progression in G2/M phase, and it can significantly increase the expressions of CDC2 mRNA and Cyclin B1 mRNA of HL-60 cells. G2/M phase blockage may be one of its molecular mechanism for treating leukemia.