Effect of matrine and cisplatin in combination on PDCD4 expression in SK-NEP-1 cells / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Matrine, a major ingredient of sophora, has an anti-tumor activity, capable of suppressing the proliferation and metastasis and promoting apoptosis or differentiation of tumor cells. This study was designed to investigate the effects of matrine on survival and apoptosis of nephroblastoma cell line SK-NEP-1, reduction of drug-resistance of cisplatin and the mechanism(s) underlying these effects.</p><p><b>METHODS</b>SK-NEP-1 cells were treated with matrine and cisplatin at various doses (0.5, 1.0 and 1.5 mg/mL), either each alone or in combination. The viability in treated SK-NEP-1 cells was assessed by MTT colorimetric assay, apoptosis by flow cytometry, and PDCD4 mRNA abundance by RT-PCR.</p><p><b>RESULTS</b>As compared with the non-treatment control, matrine and cisplation, regardless of combination and dosage, significantly reduced the viability (P<0.01), induced apoptosis (P<0.01), and increased PDCD4 mRNA abundance (P<0.01), in SK-NEP-1 cells. The above effects of matrine and cisplation were dose-dependent when they were used alone, and were more pronounced when they were used in combination (P<0.05).</p><p><b>CONCLUSIONS</b>Matrine can significantly induce apoptosis and inhibit growth of SK-NEP-1 cells in a dose-dependent manner, thus increasing the chemotherapeutic sensibility of cisplatin. The observed effects of matrine may be a result of increased PDCD4 expression.</p>

Effects of matrine on the proliferation and apoptosis of human rhabdomyosarcoma RD cells / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the effects of matrine on the proliferation and apoptosis of human rhabdomyosarcoma RD cells in vitro, and to explore the mechanism of matrine inducing apoptosis of RD cells.</p><p><b>METHODS</b>MTT assay was used to measure the proliferation inhibition rates of RD cells that were treated with matrine (final concentrations= 0.5, 1.0, 1.5, and 2.0 mg/mL). Flow cytometry was used to evaluate the apoptosis of RD cells treated with the four concentrations of matrine. RT-PCR was used to measure the mRNA expression of cyclin D1 and survivin in RD cells treated with 0.5, 1.0, and 1.5 mg/mL of matrine.</p><p><b>RESULTS</b>The RD cells treated with various concentrations of matrine showed significantly higher proliferation inhibition rates and apoptotic rates than those that were not treated with matrine (P<0.01), and with increased matrine concentration, the proliferation inhibition rate of RD cells increased gradually, thus exhibiting a dose dependence. The mRNA expression of cyclin D1 and survivin was seen in all RD cells, but was significantly lower in RD cells treated with matrine than in those that were not treated with matrine (P<0.01). There were significant differences in cyclin D1 mRNA level among the RD cells treated with 0.5, 1.0, and 1.5 mg/mL of matrine (P<0.05), while there was significant difference in survivin mRNA level between the RD cells treated with 0.5 and 1.5 mg/mL of matrine (P<0.05).</p><p><b>CONCLUSIONS</b>Matrine can significantly inhibit proliferation and induce apoptosis of RD cells, which may be related to downregulating the mRNA expression of cyclin D1 and survivin.</p>

Effect of proteasome inhibitor MG-132 on L1210 cell apoptosis and its mechanism / 中国实验血液学杂志

This study was aimed to investigate the effect of proteasome inhibitor MG-132 on apoptosis of L1210 cells and its mechanism. L1210 cells were treated with MG-132 of different concentrations (0, 2.5, 5, 10, 10 micromol/L). Cell viability was tested by MTT assay, apoptosis rate was detected by using flow cytometry, activity of caspase 3 was detected by colorimetry, the expression of NF-kappaB nuclear protein was detected by Western blot. The results showed that the growth inhibition of L1210 cells treated for a same time (24 hours) was enhanced along with increasing of MG-132 concentrations (0, 2.5, 5, 10, 20 micromol/L); the inhibitory rate, apoptosis rate and activity of caspase 3 increased also along with raising of MG-132 concentrations; while the expression of NF-kappaB nuclear protein decreased along with raising of GM-132 concentrations. It is concluded that MG-132 can induce the apoptosis of L1210. The mechanism of apoptosis may be related to the down-regulation of the expression of NF-kappaB and the activation of caspase 3.

Reversal effect of nuclear factor-κB protease inhibitor PDTC on multidrug resistance of K562/AO₂ cells and its mechanism / 中国实验血液学杂志

This study was purposed to investigate the relationship between activation of nuclear factor-κB (NF-κB) and multidrug resistance in K562/AO₂ cells and its mechanism. Human erythroleukemic cell line K562 and its adriamycin-resistant counterpart K562/AO₂ cells were used in the study. After inhibiting the activation of NF-κB with noncytotoxic concentration of antioxidant pyrrolidine dithiocarbamate (PDTC) in vitro, the multiple of drug resistance of K562/AO₂ cells was assessed by MTT assay. RT-PCR and flow cytometry method were used to detect the relative expression of mdr-1 mRNA and P-gp, respectively. The results showed that (1) multidrug resistance of K562/AO₂ cells to ADM was 59 times higher than that of K562 cells. When being pretreated with 0.2 μmol/L PDTC which is noncytotoxic to cells, the IC₅₀ of ADM in K562/AO₂ cells was sharply decreased with relative reverse efficiency of 93.03%, which was more higher than that of classic modifying agents Verapamil (Ver); (2) NF-κB activity of K562/AO₂ cells was significantly higher than that of K562 cells (p < 0.01). When being treated with PDTC, the activation of NF-κB was sharply decreased in K562/AO₂ cells; with 0.2 μmol/L PDTC for 24 hours it decreased to the lowest, nearly to the K562 cell level (p > 0.05); (3) the relative expression of both mdr-1 mRNA and P-gp in K562/AO₂ cells was more higher; the expressions of mdr-1 mRNA and P-gp both were inhibited in K562/AO₂ cell group treated with PDTC for 48 hours. It is concluded that the PDTC used as an inhibitor of NF-κB activity can partially reverse the multidrug resistance of K562/AO₂ cells, which mechanism can be associated with the down-regulation of mdr-1 mRNA and P-gp.

Effect of proteasome inhibitors MG-132 at different doses on cultured K562 cell apoptosis / 中国实验血液学杂志

This study was aimed to investigate the effect of proteasome inhibitor MG-132 at different doses on cultured K562 cell apoptosis. MTT assay was used to observe the activity of K562 cell proliferation inhibition rate after treating for 48 hours at different doses (0, 2, 4, 8, 16, 32 micromol/L). Immunocytochemistry was used to detect the NF-kappaB activity and glucocorticoid receptor (GR) expression. Flow cytometry was used to determine the K562 cell apoptosis. The results indicated that proliferation inhibition rate of K562 cells after treated for 48 hours showed dose-dependent, the inhibitory rates of cell proliferation in test groups were significant higher than that in control group, and the effect in 32 micromol/L test group was the most obvious (45.24 +/- 4.12)% (p < 0.05). The NF-kappaB activity and GR expression after treating for 48 hours showed dose-dependent. Compared with control group, the NF-kappaB activities in test groups were lower (p < 0.05), and the NF-kappaB activity in 32 micromol/L test group was the lowest (63.60 +/- 2.95); the GR expression in test groups was higher (p < 0.05), and the GR expression in 16 micromol/L test group was the highest (75.62 +/- 2.70). The K562 cell apoptosis rate after treating for 48 hours also showed dose-dependent. Compared with control group, the K562 cell apoptosis rates in test groups were higher (p < 0.05), the K562 cell apoptosis rate in 32 micromol/L test group was the highest (21.37 +/- 2.02)%. It is concluded that the MG-132 may induce K562 cell apoptosis and proliferation inhibition through up-regulation of NF-kappaB activity and down-regulation of GR expression both in dose-dependent manner.

Effect of N-tosyl-L-phenylalnylchloromethyl ketone and dexamethasone on expression of nuclear transcription factor-kappaB in childhood acute lymphoblastic leukemia and its significance / 中国实验血液学杂志

In order to investigate the effect of N-tosyl-L-phenylalnylchloromethyl ketone (TPCK) and dexamethasone (Dex) on expression of nuclear transcription factor-kappaB (NF-kappaB) in childhood acute lymphoblastic leukemia (ALL) and its significance, so as to provide the experimental basis for corresponding clinical treatment of ALL, in which NF-kappaB is taken as a target. The biotin-streptavidin method was used to detect the expression of NF-kappaB P65 protein and the effects of TPCK and Dex at clinically relevant dosage on activity of NF-kappaB P65 protein in 20 childhood ALL patients. The results indicated that the expression of NF-kappaB P65 protein was strongly diminished and reached to negative level at 2 hours by treatment with 40 micromol/L TPCK, the positive expression of NF-kappaB P65 protein was (2.5 +/- 1.6)%. TPCK had a time-dependent inhibitory effect on ALL cells cultured in vitro. The expression of NF-kappaB P65 protein in ALL cells was strongly inhibited by clinically relevant concentration of dexamethasone 5.0 microg/ml for 24 hours in vitro. The positive expression was (25.0 +/- 3.0)%, there was significant difference, as compared with untreated ALL cells (T=55, P<0.01). It is concluded that TPCK and Dex can inhibit NF-kappaB activity. Inhibition of NF-kappaB activity may be one of the effect mechanism of dexamethasone on ALL cells. Inhibition of NF-kappaB conduction pathway may have a significant value in childhood ALL treatment.

Expression of nuclear transcription factor kappaB in childhood acute lymphoblastic leukemia and its significance / 中国实验血液学杂志

To investigate the expression of nuclear transcription factor kappaB (NF-kappaB) in childhood acute lymphoblastic leukemia (ALL) and its significance, the biotin-streptavidin method and microscopy were used to detect NF-kappaB P65 protein in cells from 32 childhood ALL patients and 40 children without hematologic malignancies as control. The results showed that the positive expression rate of NF-kappaB P65 protein in cells from 32 childhood ALL patients was 87.50%, obviously higher than that in control group (12.50%) (chi(2) = 40.56, p < 0.01). In 28 childhood ALL patients with positive expression, the ratio of weakly positive (+) cases to all positive cases was 10.71% (3/28); the ratio of generally positive (++) case was 42.86% (12/28), and the ratio of strongly positive (+++) cases was 46.43% (13/28). While in the control group the of NF-kappaB P65 protein showed low expression with 100% (5/5). There was significant difference in the level of NF-kappaB P65 protein between ALL patients and control group. While the level of NF-kappaB P65 protein had no significent difference in morphology, immunophenotype (T-lineage ALL and B-lineage ALL) and the courses in the de novo and the relaspsed cases. It is concluded that NF-kappaB P65 protein expresses in cells of childhood ALL, the inhibition of NF-kappaB transduction pathway may have significant value in childhood ALL treatment. This study provides experimental basis concerning clinical treatment for ALL, when NF-kappaB is taken as a target.

Different Doses of Calcium 5-Formyltetrahydrofolate for Protecting Enteral Mucosa after Chemotherapy of High-Dose Methotrexate in Rats / 实用儿科临床杂志

Objective To explore different doses of calcium 5-formyltetrahydrofolate(CF)for protecting enteral mucosa after chemotherapy of high-dose methotrexate(HD-MTX) in rats.Methods Sixty of 6 weeks old Wistar rats were divided into 5 groups in random,12 rats every group.Group A:control group,normal sodium(NS) intraperitoneal injection only;Group B to E:after HD-MTX intraperitoneal injection(120 mg/kg),1% CF(CF dose amounts to 1% of total MTX dose) for group B,2% CF for group C,8% CF for Group D and empty for group E.For group B、C and D,CF were intramuscular injected after 12 hours of MTX used,q6h?7 times.Rats were killed after 18 hours of the last time of CF.Morphous of jejunum dissection were observed and length of intestinal villus and depth of crypt were mea-sured.Results For group A,jejunum walls were thick and elastic and intestinal villus were close and orderly.Jejunum walls were congestive,swollen and thin,length of intestinal villus and depth of crypt reduced both in group B to E.These were most obvious in group E,and were secondary in group B.Statistical analysis showed that significant difference in effect existed between group B,C,D,E and group A(Pa0.05).Conclusion MTX can damage in intestinal mucosa of rats,CF can reduce this damage,excessive low doses of CF can't play this role.

Effect and Significance of Dexamethasone on Expression of Nuclear Transcription Factor-?B in Childhood Acute Lymphoblastic Leukemia / 实用儿科临床杂志

Objective To investigate the expression and significance of nuclear transcription factor-?B(NF-?B) in childhood acute lymphoblastic leukemia(ALL) and the effect of dexamethasone(DEX) on its expression,to provide the experimental base for corresponding clinical treatment of the ALL,in which NF-?B is taken as a target.Methods 1.The biotin-streptavidin method was used to detect NF-?B P65 protein on 20 childhood ALL patients and 20 healthy children.2.The effect of DEX at clinically relevant dosage on NF-?B P65 protein were also detected by the biotin-streptavidin method.Results 1.The positive expression rate of NF-?B P65 protein in childhood ALL patients was 85.50%,obviously higher than that in normal group(10.0%)(?~2=22.56 P