Sorting of side population cells from multiple myeloma cell lines and analysis of their biological characteristics / 中国实验血液学杂志

This study was aimed to sort the side population (SP) cells from human multiple myeloma cell lines, then detect the biological characteristics of those SP cells. After Hoechst33342 staining, intracellular Hoechst33342 fluorescence staining differences of myeloma cell lines observed by the fluorescence microscopy. The fluorescence-activated cell sorting (FACS) technology was used to isolate SP cells and main population (MP) cells; proliferative capacity in vitro was determined by cell growth curve; the cell colony forming ability was compared by colony forming test. The CD138 expression was detected by flow cytometry. The expression of ABCG2 mRNA was detected by reverse transcription PCR; CCK-8 assay and colony forming test were used to evaluate the effect of bortezomib on the cell proliferation, vitality and colony forming ability of the two populations. The results showed that the myeloma cell lines had a small proportion of SP cells, especially, RPMI 8226 cells accounted for the highest proportion of SP cells (7.10 ± 2.69)%, which have also been confirmed under the fluorescence microscope; the proliferative activity and cell colony forming ability of SP cells were significantly higher than those of MP cells (P < 0.05). The expression levels of CD138 in SP and MP cells were not significantly different (P > 0.05). RT-PCR results showed that SP cells expressed the drug-resistance gene ABCG2, but MP cells hardly express these genes. The inhibition rate of bortezomib on SP cells was significantly lower than that on MP cells (P < 0.05), however, the difference was not significant (P > 0.05) at bortezomib 40 nmol/L. Bortezomib could reduce colony formation in the both two cell populations, but more severe reduction appeared in the MP cells. It is concluded that the myeloma cell line contain a small amount of SP cells with the cancer stem cell characteristics.

Effects of down-regulated TRAF6 gene expression on the proliferation and apoptosis in multiple myeloma cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the down-regulated TRAF6 gene expression and its effects on proliferation and apoptosis in multiple myeloma (MM) cells.</p><p><b>METHODS</b>Detection of TRAF6 expression were conducted by RT-PCR and Western blot in MM cell lines of KM3, U266, RPMI8226 and primary cells from patients. RPMI8226 cell lines were transfected with siRNA of TRAF6. The efficiency of transfection was identified by using of fluorescence microscope, RT-PCR, and Western blot. The levels of proliferation were analyzed by CCK-8 method under the different concentrations of siRNA. Apoptosis rate were detected with Hoechst33258/PI double staining by flow cytometry. Apoptosis related proteins Bcl-2, BAX, and NF-κB signal pathway were observed before and after siRNA transfection by Western blot.</p><p><b>RESULTS</b>The levels of TRAF6 mRNA and protein in MM cell lines, especially in primary myeloma cells, were significantly higher than those in controls. After transfected with 50 nmol/L siRNA in RPMI8226 cells, the relative level of TRAF6 mRNA (0.49±0.24) was significantly lower than that in non-transfected group (1.87±0.23) and idling group (1.74±0.35). The proliferation rate of siRNA transfected cells decreased with dose dependence (P<0.01). The apoptosis rates increased from 11.20% (before transfection) to 51.82% (after transfection), accompanied by down-regulated Bcl-2 protein, NF-κB signal pathway (p-p65 and p52), and up-regulated BAX protein.</p><p><b>CONCLUSION</b>TRAF6 expression was high in myeloma cells. TRAF6 siRNA could inhibit proliferation of myeloma cells and induce apoptosis mediated by NF-κB classical and alternative pathway in myeloma cells.</p>

The Effects of IFN-γ on AKT activated 32D Cells and its Mechanisms / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of activated AKT on murine myeloid precursor cells (32D cells), and the effects of IFN-γ on 32D cells and its mechanisms.</p><p><b>METHODS</b>Plasmid transduction was used to enhance the expression of AKT on 32D cells. After the transfected cells treated with IFN-γ for 24 hours, proliferation rate was tested by WST-1, apoptosis by flow cytometry, expression of phosphorylated Erk1/2, Stat3 and phosphorylated Stat3 was determined by Western blot.</p><p><b>RESULTS</b>(1) IFN-γ at low concentration (100 U/ml) enhanced the growth and proliferation of 32D cells, while at high concentration (1000 U/ml) suppressed them. (2) Compared with control groups, low concentration IFN-γ increased (1124 ± 13) Stat3 phosphorylation in 32D-cell, while it high concentration IFN-γ decreased (601 ± 13). 32D cells transfected with activated Akt grew rapidly (0.287 ± 0.010) and had a low apoptotic rate [(9.57 ± 0.17)% (P < 0.05)]. (3) The expression of p-Erk1/2 in transfected 32D-cell was significantly reduced (P < 0.05). (4) Apoptosis rate of IFN-γ treated group was significantly decreased in transfected 32D cells (P < 0.05).</p><p><b>CONCLUSIONS</b>IFN-γ has dual effects on 32D cells, namely, at low concentration enhanced the growth and proliferation of 32D cells, while at high concentration suppressed them. Its mechanisims is possibly through Stat3 pathway. Activated Akt can significantly promote the growth and proliferation of 32D cell and significantly inhibit apoptosis and IFN-γ can regulate cell proliferation and apoptosis through AKT. AKT activation can inhibit the Erk signal pathway, which may be affected by inhibition the modificaton of Raf1.</p>

Effect of decitabine combined with Trichostatin A on MDS cell line SKM-1 in vitro / 中国实验血液学杂志

The study was purposed to explore the effect and mechanisms of decitabine and/or Trichostatin A (TSA) on SKM-1 cells in vitro. The effect of decitabine and/or TSA on proliferation of SKM-1cells was analyzed with trypan blue exclusion; the differentiation of SKM-1 cells was detected by nitro-blue tetrazolium (NBT) reduction and flow cytometry; the apoptosis of cells was measured by Annexin V-FITC; the mRNA expression of Fas, survivin and P15(INK4B) in cells treated with decitabine and/or TSA was evaluated by RT-PCR. The results showed that decitabine and/or TSA were capable of inhibiting SKM-1 cell growth and promoting cell differentiation; they stimulated the expression of CD14 and CD11b and inhibited HLA-DR expression; meanwhile and decitabine or/and TSA could induce cell apoptosis, up-regulate mRNA expression of Fas and P15(INK4B), and down-regulate survivin mRNA expression. It is concluded that decitabine can induce apoptosis/differentiation of SKM-1 cells, whose mechanisms may related to the expression of Fas, survivin and P15(INK4B). Decitabine has the synergistic effect with TSA.

Apoptosis induction and phosphorylated protein kinase C epsilon expression in 32D cells by sera from patients with aplastic anemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of phosphorylated protein kinase C epsilon (pPKC epsilon) on apoptosis of 32D cells induced by sera from patients with aplastic anemia (AA).</p><p><b>METHODS</b>The expression of pPKC epsilon and apoptosis in 32D cells were measured by Western blotting and flow cytometry after incubation with sera from healthy individuals (controls, n = 8), patients with severe AA ( SAA, n = 8)and non severe AA (NSAA, n = 6).</p><p><b>RESULTS</b>After incubation for 0, 12, 24, 36 and 48 hours in the presence of serum and for another 4 hours in medium deprived of serum, the levels of pPKC epsilon in cells in SAA and NSAA group increased gradually, peaked at 24 hours, and then declined (P < 0.05). Compared with that in control group (0.54 +/- 0.08), pPKC epsilon was overexpressed in both SAA group (0.90 +/- 0.10) and NSAA group (0.64 +/- 0.08) (P < 0.05) after 24 hours incubation with serum and subsequent 4 hours without serum. pPKC epsilon level was higher in SAA group than in NSAA group (P < 0.05). A greater proportion of 32D cells showed apoptosis after 24 hours incubation with sera from SAA patients [(4.05 +/- 1.05)%] and subsequent 4 hours incubation without serum than that in controls [(2.45 +/- 0.51)%, P < 0.05], which was correlated with the same serum-induced expression of pPKC epsilon (r = 0.869, P < 0.05). Although the mean level of pPKC epsilon expression was higher in NSAA group than in control group, no significant difference of apoptosis was found between the two groups [(2.45 +/- 0.51)% vs (3.24 +/- 0.56)%, P > 0.05].</p><p><b>CONCLUSION</b>Sera from both SAA and NSAA patients could upregulate the expression of pPKC epsilon in 32D cells. The SAA sera induce apoptosis in 32D cells significantly, but the latter do not.</p>

Cytogenetic and clinical study of myeloid leukemia / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the clinical cytogenetic features and prognosis of myeloid leukemia patients.</p><p><b>METHODS</b>Bone marrow direct method and/or 24h culture without phytohaemagglutimin(PHA) were used to prepare the chromosomes and karyotype analysis was performed with R-banding and G-banding techniques.</p><p><b>RESULTS</b>Among 420 patients with acute myeloid leukemia (AML), 223 cases were found to exhibit clonal chromosome abnormalities, accounted for 53.1%. t(8; 21), t(15; 17), inv(16)and del(11) were specifically associated with M2b, M3, M4Eo and M5 respectively. Out of 158 patients with chronic myeloid leukemia (CML), 96.8% (153/158) were found to exhibit clonal chromosome abnormalities. T(9;22) was specifically associated with CML and some cases of M0, M1 and M2. In these myeloid leukemia cases, there were 18 cases (AML 13 cases, CML 15 cases) without clonal chromosome abnormalities, accounted for 3.1% (18/578) and this phenomenon agreed with the diagnose of clinical signs, marrow morphology and immunology incompletely.</p><p><b>CONCLUSION</b>Karyotype analysis was not only helpful to the diagnose and differential diagnose of myeloid leukemia, but also an important standard of the remission, relapse and therapeutic effect of myeloid leukemia. Chromosome analysis can be made exactly with the probe and FISH technique on the basic of chromosome karyotype analysis.</p>

Apoptosis of in vitro cultured BMMNC from MDS patients induced by arsenic sulfide / 中国实验血液学杂志

The aim of this study was to investigate the inhibition effect of arsenic sulfide (As2S2) on the growth of in vitro cultured BMMNC from MDS patients and to explore its possible cellular and molecular mechanisms. The apoptosis of MDS cells induced by As2S2 solution of different concentrations were studied with MTT, flow cytometry, and RT-PCR. The results showed that (1) low concentration of As2S2 (0-0.6 mg/L) had no marked inhibition effect on proliferation of MDS cells; (2) after treatment with 1.5-50 mg/L of As2S2, both low risk MDS cells and high risk MDS cells presented typical features of apoptosis with a dose-dependent manner, the expression of bcl-2 mRNA and the ratio of bcl-2/bax obviously decreased after As2S2 treatment (P < 0.05); (3) BMMNC from MDS patients had higher apoptosis ratio than that of BMMNC from control. It is concluded that BMMNC excessive apoptosis exists in MDS patients; low concentration of As2S2 (0-0.6 mg/L) shows no inhibition effect on proliferation of MDS cells; high concentration of As2S2 (1.5-50 mg/L) induces apoptosis of MDS cells.

Expression of vascular endothelial growth factor in patients with aplastic anemia and its significance / 中国实验血液学杂志

This study was aimed to investigate the expression of vascular endothelial growth factor (VEGF) in patients with aplastic anemia. The gene expressions of VEGF in mononuclear cells of bone marrow from 7 cases of aplastic anemia and 12 normal controls were detected by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The expressions of VEGF in bone marrow from 20 cases of aplastic anemia and 20 normal controls were also determined by immunohistochemistry assay. The results showed that expression of VEGF mRNA was found in 2 out of 7 (28.57%) bone marrow of patients and in 10 out of 12 (83.33%) bone marrow of normal controls. The VEGF mRNA in patients with aplastic anemia was significantly lower than that in normal controls (P < 0.05). No patients with aplastic anemia showed immunohistochemical staining of VEGF in bone marrow, while 5 out of 20 (25%) normal controls exhibited VEGF positive cells. Bone marrow of aplastic anemia patients contained less VEGF than that of normal persons (P < 0.05). In conclusion, when compared with normal controls, VEGF expression decreased significantly in patients with aplastic anemia at gene transcription level and protein translation level, it may be related to the defect of angiogenesis and thus hematopoiesis in bone marrow of patients with aplastic anemia.