Cytotoxic antimelanoma drugs suppress the activation of M2 macrophages

Together with regulatory T cells (Tregs), tumor‐associated macrophages (TAMs) play roles in maintaining the tumor microenvironment. Although cytotoxic antimelanoma drugs such as dacarbazine (DTIC), nimustine hydrochloride (ACNU) and vincristine (VCR) have been used for the treatment of malignant melanoma as adjuvant therapy in Japan, the detailed mechanisms of their immunomodulatory effects are not fully understood. As the majority of TAMs are alternatively activated M2 macrophages that favour tumor development, the aim of this study was to elucidate the immunomodulatory effects of these reagents on human monocyte‐derived M2 macrophages. First, mRNA expressions and protein production of immune checkpoint molecules, PD‐L1 and chemokines by CD163⁺ CD206⁺ M2 macrophages derived from peripheral blood mononuclear cells were investigated to determine the immunomodulatory effects of DTIC, ACNU, and VCR. DTIC and VCR significantly decreased PD‐L1 mRNA expression, which was confirmed by flow cytometry. Moreover, the mRNA expression and production of CCL22 were significantly decreased by DTIC, which suggested that DTIC might suppress the recruitment of Tregs in the tumor site. Furthermore, the decreased expression of PD‐L1 and production of CCL22 were validated in vivo, using the B16F10 mouse melanoma model, leading to abrogation of the suppressive function of T‐cell proliferation. The present report suggests one of the possible antimelanoma mechanisms of DAV combination chemotherapy for melanoma patients.     

A small-molecule antagonist of human and murine CCR1 receptors

Chemokine receptors have been recognised as attractive targets for drug development. Although the notion that chemokine receptor antagonism can significantly reduce inflammation has been supported by evidence obtained with modified chemokines and antibodies to chemokines or their receptors, the focus of most pharmaceutical organisations have been small molecular weight antagonists. A small molecule antagonist with high affinities to both human and mouse CCR1 receptors has been prepared by modifications of a lead compound, xanthene-9-carboxamide. This molecule also functions as a human CCR3 antagonist. This molecule should be an important tool in establishing the role of CCR1 and CCR3 receptors in established murine models of disease.     

Adipocyte-derived players in hematologic tumors: useful novel targets?

Introduction: Adipocytes and their products play essential roles in tumor establishment and progression. As the main cellular component of the bone marrow, adipocytes may contribute to the development of hematologic tumors.

Areas covered: This review summarizes experimental data on adipocytes and their interaction with various cancer cells. Special focus is set on the interactions of bone marrow adipocytes and normal and transformed cells of the hematopoietic system such as myeloma and leukemia cells. Current in vitro and in vivo data are summarized and the potential of novel therapeutic targets is critically discussed.

Expert opinion: Targeting lipid metabolism of cancer cells and adipocytes in combination with standard therapeutics might open novel therapeutic avenues in these cancer entities. Adipocyte-derived products such as free fatty acids and specific adipokines such as adiponectin may be vital anti-cancer targets in hematologic malignancies. However, available data on lipid metabolism is currently mostly referring to peripheral fat cell/cancer cell interactions and results need to be evaluated specifically for the bone marrow niche.     

A proinflammatory chemokine, CCL3, sensitizes the heat- and capsaicin-gated ion channel TRPV1

Pain, a critical component of host defense, is one hallmark of the inflammatory response. We therefore hypothesized that pain might be exacerbated by proinflammatory chemokines. To test this hypothesis, CCR1 was cotransfected into human embryonic kidney (HEK)293 cells together with transient receptor potential vanilloid 1 (TRPV1), a cation channel required for certain types of thermal hyperalgesia. In these cells, capsaicin and anandamide induced Ca(2+) influx mediated by TRPV1. When CCR1:TRPV1/HEK293 cells were pretreated with CCL3, the sensitivity of TRPV1, as indicated by the Ca(2+) influx, was increased approximately 3-fold. RT-PCR analysis showed that a spectrum of chemokine and cytokine receptors is expressed in rat dorsal root ganglia (DRG). Immunohistochemical staining of DRG showed that CCR1 is coexpressed with TRPV1 in >85% of small-diameter neurons. CCR1 on DRG neurons was functional, as demonstrated by CCL3-induced Ca(2+) ion influx and PKC activation. Pretreatment with CCL3 enhanced the response of DRG neurons to capsaicin or anandamide. This sensitization was inhibited by pertussis toxin, U73122, or chelerythrine chloride, inhibitors of Gi-protein, phospholipase C, and protein kinase C, respectively. Intraplantar injection of mice with CCL3 decreased their hot-plate response latency. That a proinflammatory chemokine, by interacting with its receptor on small-diameter neurons, sensitizes TRPV1 reveals a previously undescribed mechanism of receptor cross-sensitization that may contribute to hyperalgesia during inflammation.     

CXCL10对βTC6细胞TLR4表达及细胞凋亡的影响

目的探讨CXC趋化因子配体10(CXCL10)对βTC6细胞Toll样受体4(TLR4)表达及细胞凋亡的影响。方法体外培养βTC6细胞,0.1~10.0ng/mL CXCL10分别干预βTC6细胞12,24,48h后,应用Westernblot检测TLR4表达情况,流式细胞术和DNA Ladder检测细胞凋亡情况。结果与对照组比较,CXCL10干预12h,10.0ng/mL干预组开始出现TLR4蛋白的表达水平上调(0.840±0.049,P<0.05);干预24h,1.0和10.0ng/mL干预组TLR4的表达水平上调[分别为(0.851±0.052)和(0.893±0.030),P<0.05];干预48h,1.0和10.0ng/mL干预组TLR4的表达进一步上调[分别为(0.876±0.046)和(0.923±0.027),P<0.05],且各干预浓度两两比较,差别均有统计学意义(P<0.05)。CXCL10干预βTC6细胞24h,仅10.0ng/mL干预组细胞出现DNA梯状条带;干预时间延长至48h,1.0和10.0ng/mL干预组均出现DNA梯状条带。流式细胞术显示,CXCL10诱导细胞凋亡呈浓度依赖性。结论长时间高浓度的CXCL10作用将导致TLR4表达显著上调,并诱导β细胞凋亡。     

119例非小细胞肺癌中CCR9的表达及其预后分析

目的：探讨 CC 族趋化因子受体9( C-C chemokine receptor 9, CCR9)在非小细胞肺癌( non-small cell lung cancer, NSCLC)中的表达及其预后判断的价值。方法应用免疫组化PV-9000两步法检测119例NSCLC及相应癌旁正常肺组织中CCR9蛋白的表达,并分析CCR9表达与临床病理特征及患者总生存率的关系。结果 CCR9在NSCLC中的阳性率(54.6%)明显高于癌旁正常肺组织(10．1%)( P <0．05);CCR9表达与 NSCLC 病理组织类型、淋巴结转移、p-TNM 分期有关( P <0．05)。 Kaplan-Meier生存分析显示肺癌中CCR9蛋白表达与患者术后总生存率呈负相关(Log-rank=9．917,P=0．002)。单因素生存分析显示,淋巴结转移、p-TNM分期、CCR9蛋白表达与NSCLC患者术后总生存率有关( P<0．05)。多因素生存分析显示,CCR9是NSCLC患者术后总生存率的独立预测因素(RR=0．447,95%CI：0．201~0．993,P<0．05)。结论 CCR9阳性患者预后较差,其可作为NSCLC患者预后判断的新生物学标志物。     

Association of highly active antiretroviral therapy failure with chemokine receptor 5 wild type

OBJECTIVES: Approximately 10% of HIV-infected patients fail to respond properly to highly active antiretroviral therapy (HAART). Among other factors, genetic variants of chemokine receptors have been shown to modify the course and outcome of HIV infection. Our objective was to investigate whether a failure of virological response is associated with polymorphisms of the chemokine receptors or cofactors. METHODS: A total of 256 HIV-infected patients receiving HAART and 221 healthy controls were analysed for the chemokine receptor 5 (CCR5)-Delta32-bp, stromal derived factor 1 (SDF1)-3'A and chemokine receptor 2 (CCR2)-64I polymorphisms. Treatment failure was defined as failure to lower the viral load below 50 HIV-1 RNA copies/mL within the first year of treatment despite good adherence. Genomic DNA was extracted from peripheral blood lymphocytes (PBL) and amplified by polymerase chain reaction (PCR). RESULTS: Successful treatment was associated with heterozygosity for the CCR5-Delta32-bp variant found in 24 of 184 responders (13%) vs. one of 72 nonresponders (1.4%; P=0.004). Eighty-four of 184 responders (45.7%) vs. 25 of 72 nonresponders (34.7%) were heterozygous for the SDF1-3'A allele (P=0.073). The CCR2-64I polymorphism was rare in both groups: 4.9% in responders vs. 1.4% in nonresponders (P=0.175). The odds ratio for successful treatment was 4.7 for individuals who tested positive for at least one variant allele of the three polymorphisms. Comparison of genotype frequencies between HIV-infected and healthy individuals showed highly significant differences (P<0.001). CONCLUSIONS: Chemokine receptor polymorphisms have a modifying effect on the virological response to HAART. Multivariate analysis demonstrated that heterozygosity for the CCR5-Delta32-bp variant is an independent prognostic factor for treatment outcome.     

趋化因子诱饵受体D6在心肌梗死后心肌重塑中的作用及机制研究

目的:研究急性心肌梗死(AMI)后患者体内趋化因子诱饵受体D6的水平变化过程以及D6在心肌梗死后影响心肌重塑的可能机制。方法:将35例AMI患者根据心肌梗死后72 h血清趋化因子CCL2的检测水平分为h CCL2high组(n=18)和h CCL2low组(n=17),流式细胞术分析外周血中CD14++CD16-炎症单核细胞比例,Q-PCR测定外周血单核细胞趋化因子诱饵受体D6 mRNA的表达,3周后超声心动图测定心脏功能。将30只AMI雄性BLAB/C小白鼠根据血清CCL2的检测水平分为m CCL2high组(n=17)和m CCL2low组(n=13),流式细胞术分析小鼠外周血中CD11b+单核细胞比例;梗死心肌冰冻切片后免疫荧光染色D6阳性细胞,Q-PCR测定心肌梗死后3 d时间梗死区D6 mRNA的表达。3周后通过小动物超声检测小鼠心脏功能。结果:h CCL2high组患者外周血中CD14++CD16-炎症单核细胞比例显著高于h CCL2low组(P<0.001),其单核细胞D6受体的表达明显低于h CCL2low组(P<0.001),但单核细胞D6的表达与患者LVEF%未见明显相关性(P=0.16)。急性心肌梗死小鼠m CCL2high组外周血中CD11b+单核细胞细胞比例显著高于m CCL2low组(P<0.001),梗死心肌组织D6 mRNA表达显著低于m CCL2low组(P<0.001),小鼠梗死心肌免疫荧光可见D6表达于CD11b阳性单核细胞和CD31阳性内皮细胞。3周后小鼠心脏超声示LVEF%与梗死区D6的表达呈正相关(P=0.01)。结论:急性心肌梗死后梗死区组织可表达趋化因子诱饵受体D6,梗死区D6的高表达可抑制心肌梗死后的炎症浸润。梗死区趋化因子诱饵受体D6通过特异性结合CCL2减少心肌梗死后心肌局部的炎症浸润进而减轻心肌梗死后的心肌重塑。