Effects of sorafenib on proliferation and apoptosis of human multiple myeloma cell RPMI 8226 / 中国实验血液学杂志

This study was aimed to investigate the effects of sorafenib on proliferation and apoptosis of MM cell line RPMI-8226, and to explore the its potential anti-tumor mechanism. The inhibitory rate of multiple myeloma cell proliferation was tested by MTT. Transmission electron microscopy was used to observe morphological and ultrastructural changes of RPMI-8226 cells treated with sorafenib. The effects of sorafenib on the apoptosis and cell cycle of RPMI-8226 cells was detected by flow cytometry. The effects of sorafenib on the expression of caspase-3, BCL-2 and MCL-1 mRNA and protein were assayed by RT-PCR and Western blot respectively. The results showed that sorafenib (0-10.0 µmol/L) could obviously inhibit the proliferation of RPMI-8226 cells in time and dose-dependent manner. Flow cytometry results showed that sorafenib could induce apoptosis of RPMI-8226 cells, the difference was statistical significance (P < 0.05). Sorafenib mainly arrested RPMI-8226 cells in the G1 phase (P < 0.05). Typical apoptotic morphological and ultrastructural changes of MM cells could be observed under transmission electron microscope, Examination of cellular signaling pathways showed that sorafenib induced upregulation of cleaved-caspase-3 expression, and simultaneous downregulation of BCL-2 and MCL-1 expression. It is concluded that sorafenib displays anti-myeloma activity. Activating the death receptor pathway and arresting cell cycle may be two of the relatated mechanisms.

Effect of mitoxantrone on proliferation and apoptosis of human multiple myeloma cell RPMI8226 / 中国实验血液学杂志

This study was aimed to investigate the effects of mitoxantrone on proliferation and apoptosis of human multiple myeloma cell line RPMI-8226 and its mechanism. The inhibitory rate of RPMI8226 cells proliferation was assayed by MTT, the morphological changes of RPMI-8226 cells were observed by inverted flurescent microscopy and transmission electron microscopy, the apoptosis rate and the cell cycle distribution of RPMI-8226 cells were detected by flow cytometry. The effects of mitoxantrone on the expression of BCL-2, BAX, caspase-3 mRNA were detected by RT-PCR, the BCL-2, BAX, caspase-3 protein expression of RPMI-8226 cells was analyzed by Western blot. The results showed that mitoxantrone could inhibit the proliferation of RPMI-8226 cells in time- and dose-dependent manners. Light microscopy showed that the cell number in mitoxantrone group was significantly less than that in control group and the cell growth arrangement was irregular, apoptotic cells could be seen. Under electron microscope, typical apoptotic morphological and ultrastructural changes could be observed, these results confirmed that the mitoxantrone could induce apoptosis of RPMI-8226 cells, the difference have statistical significance (P < 0.05). The 1.0 µg/ml low concentration of mitoxantrone mainly arrested RPMI-8226 cells in the G2/M phase(P < 0.05), and the 2.0 µg/ml high concentration of mitoxantrone mainly arrested RPMI-8226 cells in the S phase (P < 0.05). The expression of BCL-2 mRNA decreased (P < 0.05),while the expression of BAX, caspase-3 mRNA increased (P < 0.05). Western blot indicated that BCL-2 protein expression also decreased (P < 0.05) and BAX, caspase-3 protein expression increased. It is concluded that the mitoxantrone can inhibit the proliferation of RPMI-8226 cells by inducing cell apoptosis. Activation of the mitochondrial and death receptor pathways of apoptosis may be involved in the mitoxantrone-induced apoptosis, the cell cycle arrest may also play an important role in the apoptosis mechanism.

Mechanisms of cladribine-inducing apoptosis of multiple myeloma RPMI 8226 cells in vitro / 中国实验血液学杂志

This study was purposed to explore the mechanisms of cladribine (2-CdA)-inducing apoptosis of multiple mycloma RPMI 8226 cells. The MTT method was used to determine cell proliferation after being treated with 2-CdA. Apoptosis and cell cycle progression were examined by flow cytometry. Transmission electron microscopy was used to observe ultrastructural changes of RPMI 8226 cells. RT-PCR and Western blot were used to analyze the mRNA and protein expression levels of BCL-2, MCL-2 and caspase-3 respectively. The results showed that the 2-CdA inhibited proliferation of RPMI 8226 cells in time and dose-dependent manner. Typical apoptotic morphological and ultrastructure changes could be observed by electron microscopy. Flow cytometry showed that 2-CdA induced myeloma cell apoptosis and arrested myeloma cells in the G2/M phase. The mRNA expression of BCL-2 and MCL-1 decreased but that of caspase-3 not apparently changed. Western blot results suggested that the change trend of BCL-2 MCL-1 and caspase-3 was the same as result of RT-PCR. It is concluded that 2-CdA exhibits inhibitory effects on RPMI 8226 cells in vitro. Activating the mitochondrial and death receptor pathways of apoptosia may be the potential mechanism, meanwhile, the cell cycle arrest may also play a critical role in apoptosis.

Mechanisms of oxaliplatin-induced apoptosis of human multiple myeloma cell RPMI8226 / 中国实验血液学杂志

This study was aimed to investigate the effects of oxaliplatin on human multiple myeloma cell line RPMI-8226 and its mechanism. The proliferation inhibitory rate of RPMI8226 cells was assayed by MTT, the morphological changes of RPMI-8226 cells were observed by inverted fluorescent microscopy and transmission electron microscopy, the apoptosis rate and the cell cycle distribution of RPMI-8226 cells were detected by flow cytometry, The effects of oxaliplatin on the expression of Bcl-2, caspase-8, caspase-3 mRNA were tested by RT-PCR, Bcl-2 protein expression of RPMI-8226 cells was analyzed by Western blot. The results showed that oxaliplatin could inhibit the proliferation of RPMI-8226 cells in time and dose-dependent manners. Cell number in oxaliplatin group was significantly less than that in control group under light microscope, and the growth arrangement was irregular, apoptotic cells could be seen. Under electron microscope, typical apoptotic morphological and ultrastructural changes could be observed. Flow cytometry results showed that oxaliplatin could induce apoptosis of RPMI-8226 cells, the difference have statistical significance (P < 0.05). Oxaliplatin mainly arrested RPMI-8226 cells in the S phase (P < 0.05). The expression of Bcl-2 mRNA did not have apparent change, while the expression of caspase-8, caspase-3 mRNA increased (P < 0.05). Western blot results suggested that the expression of Bcl-2 protein had no obvious change. It is concluded that the oxaliplatin can induce apoptosis of RPMI-8226 cells, activating the death receptor pathway and arresting cell cycle may be two of the related mechanisms, Bcl-2 gene has unobservable effects in the process of oxaliplatin-induced cell apoptosis.

The pathogenic ecology research on plague in Qinghai plateau / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the pathogenic ecology characteristics of plague in Qinghai plateau.</p><p><b>METHODS</b>Applied molecular biology techniques, conventional technologies and geographic information system (GIS) to study phenotypic traits, plasmid spectrum, genotype, infected host and media spectrum etc.of 952 Yersinia pestis strains in Qinghai plateau plague foci, which were separated from different host and media in different regions during 1954 to 2012.</p><p><b>RESULTS</b>The ecotypes of these strains were Qingzang plateau (91.49%, 871/952),Qilian mountain (6.41%, 61/952) and Microtus fuscus (1.26%, 12/952).83.6% (796/952) of these strains contained all the 4 virulence factors (Fr1, Pesticin1,Virulence antigen, and Pigmentation), 93.26% (367/392) were velogenic strains confirmed by virulence test.725 Yersinia pestis strains were separated from Qinghai plateau plague foci carried 9 kinds of plasmid, among which 713 strains from Marmot himalayan plague foci carried 9 kinds of plasmid, the Mr were 6×10(6), 7×10(6), 23×10(6), 27×10(6), 30×10(6), 45×10(6), 52×10(6), 65×10(6) and 92×10(6) respectively. 12 Yersinia pestis strains were separated from Microtus fuscus plague foci carried only 3 kinds of plasmid, the Mr were 6×10(6), 45×10(6), 65×10(6). Meanwhile, the strains carrying large plasmid (52×10(6), 65×10(6) and 92×10(6)) were only distributed in particular geographical location, which had the category property. The research also confirmed that 841 Yersinia pestis strains from two kinds of plague foci in Qinghai plateau had 11 genomovars. The strains of Marmot himalayan plague foci were given priority to genomovar 5 and 8, amounted to 611 strains, genomovar 8 accounted for 56.00% (471/841), genomovar 5 accounted for 23.07% (194/841). Besides, 3 new genomovars, including new 1(62 strains), new 2(52 strains), new 3(48 strains) were newly founded, and 12 strains of Microtus fuscus plague foci were genomovar 14.</p><p><b>CONCLUSION</b>The main host and media of Qinghai plateau plague foci directly affected the spatial distribution regularities of plague epidemic and the pathogens characteristics, meanwhile the polymorphism of plague ecological geographic landscape leds to the complexity of Yersinia pestis' genotype.</p>

Effects of docetaxel on proliferation and apoptosis of human multiple myeloma cell RPMI8226 / 中国实验血液学杂志

This study was aimed to investigate the effects of docetaxel on proliferation and apoptosis of multiple myeloma cell line RPMI8226 and its mechanism. The inhibitory rate of multiple myeloma cells was detected by MTT, the morphological and ultrastructural changes of RPMI8226 cells were observed by using inverted fluorescent microscope and transmission electron microscope, the apoptosis-inducing effect of docetaxel on RPMI-8226 cells was determined by flow cytometry with Annexin-V FITC/PI staining, the cell distribution in cell cycle of RPMI-8226 cells was assayed using flow cytometry with PI staining; the effect of docetaxel on expression of BCL-2, caspase-8, caspase-3 mRNA was detected by semiquantitative RT-PCR, the expression changes of BCL-2 protein in RPMI-8226 cells before and after treatment with docetaxel were measured by using Western blot. The results indicated that 0.25 - 8.0 µg/ml docetaxel obviously inhibited the proliferation of RPMI-8226 cells in both time- and dose-dependent manners. Cell number of docetaxel-treated group was significantly less than control group under inverted fluorescent microscope, and the cell arrangement was irregular, necrotic cells could be seen occasionally. By transmission electron microscope, the morphological and ultrastructural changes of cell typical apoptosis could be observed, a few necrotic cells could be captured, too. Compared with control group, docetaxel induced the apoptosis of RPMI-8226 cell line (P < 0.01). Docetaxel mainly arrested RPMI-8226 cells in the G(2)/M phase (P < 0.01). The expression of BCL-2 mRNA decreased (P < 0.05), while the mRNA expression of caspase-8 and caspase-3 increased (P < 0.05). Western blot indicated that BCL-2 protein expression also decreased (P < 0.05). It is concluded that docetaxel can inhibit the proliferation of RPMI-8226 cells by inducing cell apoptosis. Activation of the mitochondrial and death receptor pathways of apoptosis may be involved in the docetaxel-induced apoptosis, cell cycle arrest may also play an important role in the apoptosis mechanism.

Study on the genotyping and microevolution of Yersinia pestis in the Qinghai-Tibet Plateau / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the distribution of genomovars and microevolution of Yersinia pestis in the Qinghai-Tibet Plateau.</p><p><b>METHODS</b>Primer pairs targeting the twenty-two different regions(DFRs) were designed for detecting the presence or deletion of each DFR in 297 strains isolated from the Qinghai-Tibet Plateau.</p><p><b>RESULTS</b>9 genomovars, i. e. Genomovar 1, 5, 6, 7, 8, 10, 11, new type and Ype-ancestor were identified in the Marmota himalayana plague focus of the Qinghai-Tibet Plateau. Among these genomovars, genomovar 5,8 and 10 were dominant types. The total rate of the three genomovars was 80.6% (204/253) and the genomovars in different regions were different. All of 44 strains of Y. pestis in the Microtus fuscus plague focus of the Qinghai-Tibet Plateau belonged to genomovar 14.</p><p><b>CONCLUSION</b>The distribution of genomovars of Y. pestis in the Qinghai-Tibet plateau had remarkable characteristics geographically. Based on the distribution of genomovars of Y. pestis, the routes of transmission and microevolution of Y. pestis were proposed.</p>