BDNF和TrkB在食管癌组织中表达及BDNF对食管癌细胞生物学行为的影响

目的 探讨脑源性神经营养因子(BDNF)和酪氨酸蛋白激酶受体(Trk)B在食管癌组织中的表达,并观察外源性BDNF对食管癌细胞生物学行为的影响.方法 采用免疫组织化学方法检测食管癌和癌旁组织中BDNF、TrkB的表达;以两种食管癌细胞株ECA109、TE-1和正常食管永生化上皮细胞株HET-1A作为实验对象,用RT-PCR和Western印迹法分别检测3种细胞中BDNF、TrkB mRNA和蛋白的表达;CCK8、Transwell实验观察外源性BDNF对食管细胞增殖和侵袭能力的影响.结果 在食管癌组织中BDNF和TrkB的阳性表达率明显高于癌旁组织(P<0.05),并且两者的表达与组织学分级、浸润深度、淋巴结转移和TNM分期有关(P<0.05);外源性BDNF能够促进TE-1细胞的增殖,具有剂量时间依赖性;Transwell实验结果显示80 ng/ml BDNF能够促进TE-1细胞侵袭.结论 BDNF和TrkB与食管癌的发生发展密切相关,BDNF能够提高食管癌细胞的增殖活力,促进细胞的侵袭.     

脑胶质瘤组织中BDNF和TrkB表达及临床意义

目的探讨脑源性神经营养因子（BDNF）及其受体酪氨酸激酶B（TrkB）在人脑胶质瘤发生、发展中的作用。方法选择脑胶质瘤组织标本48份（胶质瘤组）,正常脑组织48份（正常组）,采用免疫组化法检测两组BD-NF和TrkB蛋白表达,RT-PCR法检测BDNF和TrkBmRNA相对表达量,并分析BDNF和TrkB蛋白、mRNA与脑胶质瘤临床病理参数的关系,采用Spearman等级相关分析法分析BDNF、TrkB蛋白和BDNF、TrkBmRNA的相关性。结果胶质瘤组及正常组BDNF蛋白阳性率分别为77．1％．41．7％,TrkB蛋白的阳性率分别为81．2％、54．2％,两组比较P均〈0．05;胶质瘤组及正常组BDNFmRNA的相对表达量分别为0．76±0．15、0．48±0．07,TrkBmRNA的相对表达量分别为0．82±0．09、0．53±0．10,两组比较P均〈0．05。BDNF和TrkB蛋白、mRNA与脑胶质瘤病理分级相关,而与性别、年龄无关。BDNF、TrkB蛋白和BDNF、TrkBmRNA呈正相关。结论BDNF和TrkB在胶质瘤的发生、发展过程中可能起重要作用。     

局灶脑缺血大鼠脑源性神经营养因子及其受体的表达

目的：探讨脑缺血损伤与脑源性神经营养因子（BDNF）及其受体TrkB之间的关系。方法：用线栓法制备大鼠脑缺血模型，采用免疫组织化学方法及图像分析测定不同缺血时间额叶和顶叶BDNF及TrkB阳性神经元数目。结果：与假手术组相比，在额叶BDNF及TrkB阳性神经元数目于缺血开始增加（P＜0．05），缺血3d达到高峰（P＜0．001），缺血7d降至正常水平（P＞0．05）；在顶叶BDNF及TrkB阳性神经元数目于整个缺血过程均明显增加（P＜0．001）。结论：脑缺血损伤后，BDNF和TrkB表达同时增强，可能对脑缺血损伤有保护作用。     

脑源性神经营养因子在乳鼠结肠扩张刺激诱导的慢性内脏高敏感和肠道动力异常中的作用

背景：慢性内脏高敏感和肠道动力异常是肠易激综合征（IBS）的主要病理生理特征，但两者的形成机制至今尚未明确。目的：研究乳鼠结肠扩张刺激动物模型成年后内脏感觉和肠道动力的变化以及脑源性神经营养因子（BDNF）在其中所起的作用，从而探讨BDNF在IBS发病机制中的作用。方法：建立乳鼠结肠扩张动物模型，通过检测成年大鼠对结直肠扩张的行为学反应评估内脏感觉．通过检测全胃肠和小肠传输功能评估肠道动力。比较腹腔注射BDNF抗体后内脏感觉和肠道动力的变化情况。以逆转录聚合酶链反应（RT-PCR）、蛋白质印迹法、酶联免疫吸附测定（EUSA）检测各组回肠、结肠BDNF及其受体TrkB的表达。结果：模型组成年后内脏敏感性增高，肠道动力增强。应用BDNF抗体后模型组内脏敏感性降低，肠道动力减弱。除成年期模型组结肠TrkB mRNA表达外，其余各组BDNF和TrkB mRNA表达均显著高于对照组（P〈0．05）。乳鼠期和成年期模型组回肠、结肠BDNF和TrkB蛋白表达均显著高于对照组（P〈0．05）。结论：BDNF在慢性内脏高敏感和肠道动力的变化中起一定作用，参与了IBS的发生。     

溃疡性结肠炎患者结肠黏膜肝细胞生长因子的表达意义

目的探讨肝细胞生长因子（HGF）及其受体c-Met在活动性和非活动性溃疡性结肠炎（UC）患者结肠黏膜组织的表达意义。方法采用免疫组化SABC法检测活动性和非活动性UC患者以及对照组肠镜活检组织中HGF、c-Met表达；SP法检测增殖细胞核抗原（PCNA）表达。结果对照组、活动性UC组、非活动性UC组HGF阳性表达率分别为25％、88％、100％；c-Met阳性表达率分别为25％、92％、100％；组间比较有显著性差异，P均〈0．05；HGF、c-Met在UC结肠黏膜表达与PCNA过表达正相关（r分别为0．648、0．645，P均〈0．05）。结论HGF及其受体c-Met可能在UC结肠炎症黏膜修复中起作用。     

慢性粒细胞白血病血管新生的体外研究

目的：探讨K562细胞上清液对人脐静脉内皮细胞（HuVEc）增殖、迁移、体外小管形成的作用。方法：运用MTT法、Transwell室及体外小管形成实验观察K562细胞上清液对HUVEC增殖、迁移及体外分化的影响。Westernblot、ELISA法检测K562细胞血管内皮生长因子（VEGF）、碱性成纤维细胞生长因子（bFGF）的表达。结果：K562细胞系表达和分泌VEGF和bFGF。细胞培养上清液能明显促进HUVEC的增殖、迁移、体外小管形成,其作用随着细胞培养上清液浓度的增加而增强。结论：体外实验表明慢性粒细胞白血病患者存在血管新生,通过分泌血管新生正调控因子VEGF和bFGF,促进HUVEC的增殖、迁移、分化。     

血管内皮生长因子调节内皮祖细胞生物学功能

目的研究血管内皮生长因子（VEGF）对体外培养骨髓源性内皮祖细胞（EPCs）数量及增殖、迁移、黏附功能的影响及机制初探。方法密度梯度离心法获取骨髓单个核细胞,FITC-荆豆凝集素I、DiI-乙酰化低密度脂蛋白荧光双染鉴定。单个核细胞培养7d后分为对照组和VEGF干预组。VEGF干预组加入不同浓度VEGF（25,50,75,100μg／L）培养48h,分别采用四氮唑溴盐比色法、改良的Boyden小室和黏附能力测定观察EPCs的增殖、迁移和黏附能力。RT—PCR法半定量检测VEGF对EPCs内皮型一氧化氮合酶（eNOS）mRNA表达的影响。硝酸还原酶法比色测定VEGF对EPCs分泌一氧化氮的影响。结果VEGF可浓度依赖性地增加EPCs数量并明显促进EPCs的黏附、迁移和增殖能力,与对照组比较差异显著。VEGF可上调EPCseNOSmRNA的表达,促进EPCs分泌一氧化氮。结论VEGF可能通过上调EPCseNOSmRNA的表达影响EPCs部分生物学功能。     

高迁移率族蛋白1及其受体促进人主动脉血管平滑肌细胞增殖及迁移的作用研究

目的研究高迁移率族蛋白1(HMGB1)及其受体对体外人主动脉血管平滑肌细胞(VSMC)增殖及迁移的影响。方法体外培养人VSMC株,50、100、200μg/L HMGB1作用细胞24 h后,CCK法检测VSMC的增殖情况;细胞划痕修复及Transwell小室实验检测VSMC迁移情况;Real-time PCR及Western blot检测细胞晚期糖基化终产物受体(RAGE)干扰效率;CCK法及Transwell小室实验检测沉默RAGE后HMGB1对细胞增殖及迁移的影响;Western blot检测核因子(NF-κB)蛋白表达水平。结果 HMGB1作用VSMC后可明显促进细胞增殖及迁移(P0.05);转染si RNA-RAGE后,RAGE的m RNA及蛋白表达水平明显下降(P0.05);与HMGB1组相比,si RNA-RAGE可抑制HMGB1诱导的细胞增殖、迁移及NF-κB蛋白表达(P0.05)。结论 HMGB1可促进VSMC增殖及迁移,机制可能与HMGB1和RAGE结合后激活NF-κB表达有关。     

血府逐瘀汤动员大鼠骨髓内皮祖细胞的实验研究

目的观察血府逐瘀汤动员大鼠骨髓内皮祖细胞迁移,参与血管新生的作用。方法SD大鼠随机分为生理盐水组（对照组）及血府逐瘀汤高、中、低剂量组,灌胃给药8d后,腹主动脉采血,分离含内皮祖细胞的单核细胞,进行细胞计数;血清中一氧化氮（NO）和血管内皮生长因子（VEGF）含量检测以及流式细胞仪分析细胞表型和细胞周期。结果虽然各组大鼠骨髓单核细胞数量、增殖能力以及VEGF受体（VEGFR）的表达无统计学意义（P〉0.05）;但药物促进NO的合成和分泌,对VEGF的影响作用正好相反,尤其中、高剂量组影响显著（P〈0.05）;且中剂量组能明显增加CD31的表达为25.20%±0.94%（P〈0.05）。结论血府逐瘀汤通过NO途径动员骨髓中内皮祖细胞释放,参与血管新生,说明药物能动员骨髓中内皮祖细胞迁移至外周血中,提高循环血中内皮祖细胞的数量。     

骨髓涂片与骨髓活检的临床应用价值评价

目的进一步提高血液病临床诊断水平。方法回顾性分析262例同时行骨髓涂片和活检切片检查患者的临床资料。按临床拟诊分为三组,1组为临床拟诊再生障碍性贫血（从）、慢性骨髓增殖性疾病（CMPD）的152例患者,2组为临床拟诊多发性骨髓瘤（MM）、淋巴瘤、骨髓转移癌的23例患者,3组为临床拟诊骨髓增生异常综合征（MDS）、巨幼细胞性贫血（MA）及其他的87例患者。分别计算骨髓涂片与骨髓活检诊断的灵敏度、特异度、漏诊率、误诊率、符合率、阳性预测值、阴性预测值。结果整体病例骨髓活检较骨髓涂片有较高的诊断符合率;1组和2组活检的灵敏度和特异度均高于涂片;3组活检的灵敏度略低于涂片,但特异度明显高于涂片。结论涂片和活检与最终诊断符合率大致相同,涂片具有形态学观察优势,但对结构和定位的观察欠缺;活检能准确观察到造血细胞的结构与定位,但部分细胞的形态较难把握。骨髓涂片检查与骨髓活检联合应用可提高诊断的符合率,减少误诊。     

Overexpression of Annexin II affects the proliferation, apoptosis, invasion and production of proangiogenic factors in multiple myeloma

The abnormal expression of Annexin II (AnxA2, A2) has been associated with the development of tumors; however, its expression and function in multiple myeloma (MM) is less known. We compared the expression of AnxA2 in primary myeloma cells from MM patients with that in normal plasma cells from normal subjects and found that myeloma cells from patients had higher expression of AnxA2. Expression of AnxA2 was also significantly higher in MM cell lines U266 and RPMI8226, compared with other hematologic tumor cell lines. Transfecting U266 and RPMI8226 cells with the small interfering RNA (siRNA) that targets human AnxA2 led to significant downregulation of AnxA2 expression, which resulted in the decreased proliferation, invasive potential and increased apoptosis of U266 and RPMI8226 cell lines. Silencing AnxA2 gene by siRNA also inhibited the expression of pro-angiogenic molecules including VEGF-C, VEGF-R2, MMP-2, MMP-9, MT1-MMP and TIMP-2 in the two cell lines. Our data suggested that the AnxA2 is overexpressed in MM patients and myeloma cell lines U266 and RPMI8226, and that AnxA2 overexpression appeared to affect the proliferation, apoptosis, invasive potential and production of pro-angiogenic factors in MM cell lines U266 and RPMI8226.     

A neurotrophin axis in myeloma: TrkB and BDNF promote tumor-cell survival

Multiple myeloma (MM) is a B-cell neoplasm that is characterized by the clonal expansion of malignant plasma cells and is frequently associated with chromosomal translocations placing an oncogene under the control of the immunoglobulin heavy chain enhancer. Despite these pathogenic translocations, MM cells remain dependent on external cues for survival. We present evidence that brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family of growth factors, and its high-affinity receptor, tropomyosin receptor kinase B (TrkB), contribute to these survival cues. MM cells express TrkB, and respond to BDNF by activating mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3 kinase-a PI3K target (PI3K/Akt) signaling cascades. Addition of BDNF protects human MM cell lines (HMCLs) from apoptosis induced by dexamethasone or bortezomib and prolongs the survival of primary MM cells cultured alone or with human bone marrow (BM) stroma. As BDNF and TrkB are expressed by osteoblasts, stromal cells, and endothelial cells within the BM microenvironment, a BDNF-TrkB axis may be critical to the interactions of MM with bone and stroma that contribute to MM tumor progression. Finally, BDNF is expressed by malignant plasma cells isolated from a subset of patients with MM, as well as by most HMCLs, suggesting a potential role for this neurotrophin axis in autocrine as well as paracrine support of MM.     

Effect of wild type PTEN gene on proliferation and invasion of multiple myeloma

We explored the effect of the wild type PTEN gene on the proliferation, apoptosis and invasive ability of multiple myeloma (MM) cells from MM patients and RPMI 8226 cells (a human myeloma cell line), and the effect of the PTEN/focal adhesion kinase (FAK)/MMP signaling pathway on the invasion activity of RPMI 8226 cells. The proliferation of RPMI 8226 cells and purified myeloma cells from MM patients were markedly inhibited after these cells were transfected with recombinant adenovirus-PTEN vectors containing green fluorescent protein (Ad-PTEN-GFP). Maximum growth inhibition of RPMI 8226 cells and purified myeloma cells from MM patients by AD-PTEN-GFP was 42.01 and 24.75%, respectively. After transfection with PTEN-siRNA, the proliferation of RPMI 8226 cells was increased significantly compared with NS-siRNA transfected controls. The maximal survival rate was 141.55 ± 8.34% in PTEN-siRNA transfected RPMI 8226 cells. Apoptosis of RPMI 8226 cells or purified myeloma cells from MM patients in the Ad-PTEN-GFP group was increased significantly when compared with that in the Ad-GFP (adenovirus vectors only expressing green fluorescent protein) group (p < 0.01). The cell cycle of RPMI 8226 cells was arrested at the G2/M phase. Furthermore, the number of cells that migrated through the matrigel and filter from the upper chamber to the lower chamber in the transwell assay in the Ad-GFP group was significantly larger than that in the Ad-PTEN-GFP group (52.65 ± 7.39 vs. 23.50 ± 6.12, p < 0.01). In the PTEN-siRNA group, the cell number (79.50 ± 11.89) was significantly larger than that in the NS-siRNA group (47.17 ± 7.76, p < 0.01). When RPMI 8226 cells were transfected with Ad-PTEN-GFP or NS-siRNA, the expression level of PTEN mRNA was up-regulated, and the expression levels of FAK, MMP-2 and MMP-9 mRNA were down-regulated significantly compared with that of the Ad-GFP group and the PTEN-siRNA group (p < 0.01, p < 0.05). The protein levels of FAK and p-FAK, MMP-2 and MMP-9 in RPMI 8226 cells which were transfected with Ad-PTEN-GFP decreased significantly, but increased significantly in PTEN-siRNA transfected RPMI 8226 cells (p < 0.01, p<0.05). These results indicated that wild type PTEN, which inhibited FAK, MMP-2, and MMP-9, could suppress the proliferation and invasion ability of multiple myeloma cells. Modulating the expression of PTEN may be a potential strategy for the treatment of multiple myeloma.     

Antitumor activity of fludarabine against human multiple myeloma in vitro and in vivo

Fludarabine, a nucleoside analogue, plays a major role in the treatment of B-cell lymphocytic leukemia, hairy cell leukemia, and indolent lymphomas. There is a controversy about antitumor activity of fludarabine in multiple myeloma (MM). The aim of this study was to evaluate the activity of fludarabine against human myeloma cells both in vivo and in vitro. We demonstrated that myeloma cell line RPMI8226 was efficiently inhibited by fludarabine, concomitantly with decreased phosphorylation of Akt, down-regulation of the inhibitor of apoptosis proteins (IAP) family, including XIAP and survivin, and induction of apoptosis related to activation of caspase cascade. Contrary to dexamethasone, the effect of fludarabine on RPMI8226 cells was independent of interleukin-6. Fludarabine also induced cytotoxicity in dexamethasone-sensitive (MM.1S) and -resistant (MM.1R) cells at 48 h with IC50 of 13.48 microg/mL and 33.79 microg/mL, respectively. In contrast, U266 cells were resistant to fludarabine. Moreover, RPMI8226 myeloma xenograft model was established using severe combined immunodeficient mice. The tumors treated with fludarabine at 40 mg/kg increased less than 5-fold in 25 d comparing with approximately 10-fold in the control tumors, demonstrating the antitumor activity of fludarabine in vivo. These results suggest that fludarabine may be an important therapeutic option for MM patients who are resistant to dexamethasone.     

Blockade of interleukin-6 signalling with siltuximab enhances melphalan cytotoxicity in preclinical models of multiple myeloma

Signalling through the interleukin (IL)-6 pathway induces proliferation and drug resistance of multiple myeloma cells. We therefore sought to determine whether the IL-6-neutralizing monoclonal antibody siltuximab, formerly CNTO 328, could enhance the activity of melphalan, and to examine some of the mechanisms underlying this interaction. Siltuximab increased the cytotoxicity of melphalan in KAS-6/1, INA-6, ANBL-6, and RPMI 8226 human myeloma cell lines (HMCLs) in an additive-to-synergistic manner, and sensitized resistant RPMI 8226.LR5 cells to melphalan. These anti-proliferative effects were accompanied by enhanced activation of drug-specific apoptosis in HMCLs grown in suspension, and in HMCLs co-cultured with a human-derived stromal cell line. Siltuximab with melphalan enhanced activation of caspase-8, caspase-9, and the downstream effector caspase-3 compared with either of the single agents. This increased induction of cell death occurred in association with enhanced Bak activation. Neutralization of IL-6 also suppressed signalling through the phosphoinositide 3-kinase/Akt pathway, as evidenced by decreased phosphorylation of Akt, p70 S6 kinase and 4E-BP1. Importantly, the siltuximab/melphalan regimen demonstrated enhanced anti-proliferative effects against primary plasma cells derived from patients with myeloma, monoclonal gammopathy of undetermined significance, and amyloidosis. These studies provide a rationale for translation of siltuximab into the clinic in combination with melphalan-based therapies.     

beta-lapachone,a novel plant product,overcomes drug resistance in human multiple myeloma cells

OBJECTIVE: To evaluate the anti-tumor potential of beta-lapachone in multiple myeloma (MM) cell lines (U266, RPMI8226, and MM.1S); MM cell lines resistant to dexamethasone (MM.1R), melphalan (RPMI8226/LR5), doxorubicin (RPMI8226/DOX40), and mitoxantrone (RPMI8226/ MR20); and MM cells from patients (MM1-MM4). MATERIALS AND METHODS: Cytotoxicity of beta-lapachone was assessed by MTT and [3H]-thymidine uptake assays. Apoptosis was analyzed using propidium iodide staining, DNA fragmentation, TUNEL assay, caspase-9 colorimetric assay, and immunoblotting for caspase-3, poly (ADP-ribose) polymerase (PARP), and caspase-8 cleavage products. Paracrine growth of MM cells was assessed by [3H]-thymidine uptake in cultures of bone marrow stromal cells (BMSCs) and MM cells. Interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) secretion in the culture supernatants was measured by specific enzyme-linked immunosorbent assays (ELISAs). RESULTS: beta-lapachone showed significant cytotoxicity in MM cells (IC(50): 4-8 microM). In contrast, normal peripheral blood mononuclear cells (PBMCs) and BMSCs from MM patients were relatively resistant (IC(50): 8-16 microM). IL-6 did not protect against beta-lapachone-induced apoptosis in MM.1S cells, and dexamethasone showed additive cytotoxicity. beta-lapachone also decreased binding of MM.1S cells to BMSCs; abrogated IL-6 and VEGF secretion triggered by adhesion of BMSCs to MM.1S cells; reduced proliferation of MM.1S cells adherent to BMSCs; and decreased intracellular adhesion molecule-1 (ICAM-1) expression on MM.1S cells. Furthermore, beta-lapachone induced typical PARP cleavage, increased caspase-9 proteolytic activity, and activation of caspase-3, without activation of caspase-8 in U266 cells. CONCLUSION: These studies provide a framework for clinical evaluation of beta-lapachone to improve the outcome for patients with MM.     

Artesunate inhibiting angiogenesis induced by human myeloma RPMI8226 cells

Multiple myeloma (MM) remains an incurable plasma cell disorder to date; therefore, new biologically target-based therapies are in urgent demand. Our previous studies showed that the antimalarial artesunate (ART) possessed anti-myeloma effect by inhibiting proliferation and inducing apoptosis of myeloma cells. The present study evaluated the effect of ART on human myeloma cell-induced angiogenesis and elucidated its mechanism. The human umbilical vein endothelial cells (HUVECs) migration test, aortic sprouting in fibrin gel in vitro and chicken chorioallantoic membrane (CAM) neovascularization in vivo model were used to examine the effect of ART on angiogenesis induced by human myeloma cells. The results showed that ART could inhibit HUVECs migration, even at a lower concentration (3 μmol/l, P < 0.01, compared with the result of control group), and suppress efficiently the angiogenic ability of myeloma RPMI8226 cells in a dose-dependent pattern (3–12 μmol/l, P < 0.05). The levels of VEGF and Ang-1 in the conditioned medium (CM) were quantified by enzyme-linked immunosorbent assay (ELISA). The results confirmed that 3 μmol/l ART could significantly decrease VEGF and Ang-1 secretion by RPMI8226 cells (P < 0.05), which correlated well with the reduction of angiogenesis induced by myeloma RPMI8226 cells. The present study also showed that ART downregulated the expression of VEGF and Ang-1 in RPMI8226 cells and reduced the activation of extracellular signal-regulated kinase 1 (ERK1) as well. Therefore, ART can block ERK1/2 activation, downregulate VEGF and Ang-1 expression and inhibit angiogenesis induced by human multiple myeloma RPMI8226 cells. Combined with our previous published data, results from the present study indicate that ART possesses potential anti-myeloma effect.     

Human myeloma cells stimulate the receptor activator of nuclear factor-kappa B ligand (RANKL) in T lymphocytes: a potential role in multiple myeloma bone disease

The biologic mechanisms involved in the pathogenesis of multiple myeloma (MM) bone disease are not completely understood. Recent evidence suggests that T cells may regulate bone resorption through the cross-talk between the critical osteoclastogenetic factor, receptor activator of nuclear factor-kappaB ligand (RANKL), and interferon gamma (IFN-gamma) that strongly suppresses osteoclastogenesis. Using a coculture transwell system we found that human myeloma cell lines (HMCLs) increased the expression and secretion of RANKL in activated T lymphocytes and similarly purified MM cells stimulated RANKL production in autologous T lymphocytes. In addition, either anti-interleukin 6 (anti-IL-6) or anti-IL-7 antibody inhibited HMCL-induced RANKL overexpression. Consistently, we demonstrated that HMCLs and fresh MM cells express IL-7 mRNA and secrete IL-7 in the presence of IL-6 and that bone marrow (BM) IL-7 levels were significantly higher in patients with MM. Moreover, we found that the release of IFN-gamma by T lymphocytes was reduced in presence of both HMCLs and purified MM cells. Furthermore, in a stromal cell-free system, osteoclastogenesis was stimulated by conditioned medium of T cells cocultured with HMCLs and inhibited by recombinant human osteoprotegerin (OPG; 100 ng/mL to 1 microg/mL). Finally, RANKL mRNA was up-regulated in BM T lymphocytes of MM patients with severe osteolytic lesions, suggesting that T cells could be involved at least in part in MM-induced osteolysis through the RANKL overexpression.     

ADP-ribosylation factor 1 (ARF1) takes part in cell proliferation and cell adhesion-mediated drug resistance (CAM-DR)

Cell adhesion-mediated drug resistance (CAM-DR) remains the primary obstacle in human multiple myeloma (MM) therapy. In this study, we aimed at investigating the expression and biologic function of ARF1 in MM. We determined that ARF1 expression was positively correlated with cell proliferation and knockdown of ARF1 contributed to CAM-DR. The enhancement in the adhesion of MM cells to fibronectin (FN) or the bone marrow stroma cell line HS-5 cells translated to an increased CAM-DR phenotype. Importantly, we showed that this CAM-DR phenotype was correlated with the phosphorylation of Akt and ERK in MM cells. Moreover, we sought to determine whether ARF1 could interact with p27 in RPMI8226 cells. Knockdown of ARF1 also significantly decreased pT157-p27 protein expression in RPMI8226 cells. Our research shows ARF1 may reverse CAM-DR by regulating phosphorylation of p27 at T157 in MM. Taken together, our data shed new light on the molecular mechanism of CAM-DR in MM, and targeting ARF1 may be a novel therapeutic approach for improving the effectiveness of chemotherapy in MM.     

丙戊酸钠对多发性骨髓瘤细胞株KM3细胞增殖及其VEGF受体表达的影响

目的：研究丙戊酸钠（VPA）对多发性骨髓瘤细胞株KM3细胞增殖和凋亡的影响,探讨其抗多发性骨髓瘤细胞的分子生物学机制。方法：采用MTT法检测细胞增殖,流式细胞仪检测凋亡率,RT—PCR检测KM3细胞VEGFRmRNA的表达;采用免疫细胞化学法观察KM3细胞VEGFR、ac—H4蛋白的表达。结果：VPA可明显抑制KM3细胞增殖,且具有时间剂量依赖性（P〈0．05）;不同浓度VPA处理48h可以明显诱导细胞凋亡,具有剂量依赖性（P〈0．05）,VPA（0．5、1．0、2．0、4．0mmol／L）诱导总凋亡率分别为（11．77&#177;4．64）％、（22．13&#177;1．20）％、（23．95&#177;2．57）％和（42．72&#177;4．61）％;RT—PCR结果显示,KM3细胞仅表达VEGFR-1（flt—1）,且VPA能在mRNA水平抑制VEGFR-1的表达;免疫细胞化学结果显示,VPA（4mmol／L）作用48h后,KM3细胞中acH4吸光度值明显增加而VEGFR-1的吸光度明显降低（P〈0．05）。结论：VPA通过增加组蛋白乙酰化程度,下调骨髓瘤细胞表面VEGFR的表达,对KM3细胞的增殖起抑制作用。