[Study on the inhibitory and pro-apoptotic effects of different concentrations of total tanshinone alone and in combination with tyrosine kinase inhibitors on human myeloid leukemia cell lines].

Objective: To explore the effect and investigate the molecular mechanism of different concentrations of total tanshinones alone and in combination with tyrosine kinase inhibitors (TKIs) on the proliferation inhibition and apoptosis of human myeloid leukemia cell lines. Methods: K562 and Kasumi-1 cell lines were purchased from the Shanghai Cell Bank of the Chinese Academy of Sciences, and the TKIs-resistant strain K562/T315I cell line was constructed in Molecular Medicine Research Center, Beijing Lu Daopei Institute of Hematology. Logarithmic growth phase cells were taken and divided into intervention groups with total tanshinone of 0, 2.19, 4.38, 8.75, 17.50 and 35.00 µg/ml intervention groups, which were inoculated in 96-well plates at a density of 1×104 cells/well and exposed to the drug for 24 h, and a control group treated with dimethyl sulfoxide was also set up simultaneously. All experiments were repeated independently 3-5 times. The proliferative activity of the cells was assessed using the CCK-8 assay, the apoptotic rates were measured by flow cytometry, and the expression levels of apoptosis-regulating proteins Bcl-2 and Bax were analyzed by Western blotting. The cell lines treated and untreated with total tanshinone were subjected to transcriptome sequencing and gene set enrichment analysis to identify differentially expressed genes. Results: The half-inhibitory concentration (IC50) values of 8.75 µg/ml total tanshinone at 24 h for K562, K562/T315I and Kasumi-1 cells were (4.11±0.02), (4.95±0.04) and (3.98±0.01) µg/ml, respectively. When combined with 0.25 µmol/L imatinib, 8.75 µg/ml total tanshinone could enhance the induction of apoptosis effects on K562 and K562/T315I cell lines. After being treated with 4.38, 8.75, and 17.50 µg/ml of total tanshinone for 24 h, compared with the control group, total tanshinone upregulated the expression level of Bax protein, downregulated the expression level of Bcl-2 protein, and decreased the Bcl-2/Bax ratio (all P<0.05). Total tanshinone inhibited the proliferation-related signaling pathway and DNA damage repair pathway of myeloid leukemia cell lines, and activated the signaling pathway that induces apoptosis in leukemia cells. Conclusion: Different concentrations of total tanshinoneinhibites proliferation and promote apoptosis in K562, Kasumi-1 and TKIs-resistant K562/T315I cell lines, and further enhance the anti-leukemic effect when combined with TKIs.

[Transcriptome sequencing-based classification and quantification of IKZF1 transcript isoforms in B-cell acute lymphoblastic leukemia].

Objective: To classify and quantify IKZF1 mutant transcripts in B-cell acute lymphoblastic leukemia (B-ALL) by RNA sequencing (RNA-seq) and bioinformatics analysis. Methods: A cohort of 263 B-ALL cases was enrolled at Hebei Yanda Ludaopei Hospital from September 2018 to September 2020. An integrated bioinformatics pipeline was developed to adapt the classification and quantification of IKZF1 transcripts from RNA-seq and was applied to sequencing data of these cases. The IKZF1 mutant transcripts classified by RNA-seq analysis were compared with the qualitative reverse transcription PCR (RT-PCR). Results: IKZF1 mutant transcripts were identified in 53 B-ALL patients by RT-PCR and Sanger sequencing, among which IK6 and IK10 transcripts accounted for 67.9% (36/53) and 28.3% (15/53) respectively. Additionally, 2 patients were double positive for IK6 and IK10. RNA-seq analysis identified 51 patients with IKZF1 mutant transcripts. Compared with the RT-PCR result, the detection sensitivity and specificity of RNA-seq analysis reached 94.3% (50/53) and 99.5% (209/210), respectively. Among the 50 patients with IKZF1 mutant transcripts both in RNA-seq and RT-PCR analysis, the ratio of mutant transcripts to total IKZF1 transcripts in 6 patients was 0.14 (0.11, 0.35), which was significantly lower than that of the other 44 patients [0.88 (0.35, 0.97), Z=-3.945,P<0.001]. IKZF1 mutations mostly occurred in Ph+and Ph-like B-ALL, characterized by abnormal JAK-STAT pathway, and B-ALL with PAX5 translocation. Conclusions: Through the optimized bioinformatics analysis process, RNA-seq data can be used to classify and quantitatively analyze IKZF1 transcripts in B-ALL. Furthermore, the relative expression of mutant IKZF1 transcripts was found to cluster into two groups, and IKZF1 mutation was found often accompanied with PAX5 translocations.

ipt Gene transformation in petunia by an Agrobacterium mediated method.

To prevent leaf senescence of petunia, the cytokinin biosynthetic gene isopentenyl transferase (ipt) was placed under the control of 35S promoter and introduced into petunia. PCR analysis showed an expected 0.5 Kb fragment of ipt gene in transgenic petunia. RT-PCR analysis indicated the expression of ipt gene in the transgenic lines. Leaves from transgenic plants remained green and healthy in normal culture condition, while the non-transformed plants turned to yellow. Transgenic plants showed a reduction in height and smaller leaf sizes. In transgenic lines, the internodes were shorter, and the roots grew slower than the non-transformed plants.

Purification and structure analysis of antifreeze proteins from Ammopiptanthus mongolicus.

We purified many kinds of antifreeze proteins with high activity from the leaves of Ammopiptanthus mongolicus by several biochemical techniques. The antifreeze activities of these AFPs were measured by both osmometry and differential scanning calorimetry, and the inhibition of growth of ice crystals by the AFPs was obvious. Additionally, the antifreeze proteins were analyzed by sequencing, glycosylation reaction, mass spectroscopy, and circular dichroism spectroscopy. Both samples have some other unique structures different from those of fishes and of insects. It was suggested that plant AFPs might have a particular antifreeze mechanism in comparison with that of fish and insects.