Nasal NK/T-cell lymphoma causing diagnostic difficulties

We present history, clinical presentation and anatomo-pathologic findings of a 24-year-old female patient with a nasal NK/T-cell lymphoma. This rare tumor is characterized by its angiocentric and angiodestructive growth, which results in extensive tumor necrosis. At the first encounter this tumor necrosis made it difficult to identify the nature of the tumor cells. However, this necrosis is a key feature: it is the result of the capacity of neoplastic NK/T-cells to invade vessels. The T-cell character of the neoplastic lymphoid has been shown by immunohistochemitry.     

p33ING1在结外鼻型NK／T细胞淋巴瘤中的表达

目的探讨抑癌基因p33ING1任结外鼻型NK／T细胞淋巴瘤（下称ENKL）中的表达情况,研究ENKL的发病机制,寻找有助于判断预后的分子标志物。方法用免疫组化方法检测p33ING1蛋白在37例ENKL和37例良性淋巴组织增生中的表达,统计各蛋白表达与临床特点及生存期的关系。结果37例良性淋巴组织增生p33ING1呈强阳性表达,在ENKL中的表达率约分别为67．57％（25／37）,显著低于良性淋巴组织增生组（P〈0．01）,p33ING1表达与LDH水平有关（P〈0．05）。结论p33ING1蛋白表达低下可促进ENKL的发生和发展。     

吉西他滨联合卡铂诱导NK/T细胞淋巴瘤细胞株凋亡的研究

目的:研究吉西他滨联合卡铂对NK/T细胞淋巴瘤细胞株(SNK 6)细胞增殖及凋亡的影响。方法:采用细胞增殖-毒性检测法(CCK-8)检测吉西他滨、卡铂、顺铂对SNK 6细胞增殖的影响,算出各自半数抑制浓度(IC 50)值;再用吉西他滨与卡铂或顺铂做联合实验,用金氏公式计算Q值,评价联合用药效应。应用流式细胞仪检测不同药物组对细胞凋亡的影响。蛋白免疫印迹法(Western Blotting)检测各药物组Cleaved-caspase-3、B淋巴细胞瘤-2蛋白(Bcl-2)、Bcl-2相关X蛋白(Bax)等凋亡蛋白的表达水平。结果:吉西他滨、卡铂、顺铂对SNK 6细胞均有较好的抑制作用;联合用药中,吉西他滨+卡铂组与吉西他滨+顺铂组对SNK 6细胞抑制作用相当,两药联合为相加作用。吉西他滨+卡铂组凋亡率稍低于吉西他滨+顺铂组,但差异无统计学意义(P>0.05)。吉西他滨可上调Cleaved-caspase-3蛋白、Bax蛋白的表达水平,下调Bcl-2蛋白的表达水平(P<0.05),吉西他滨与卡铂或顺铂联合时效果更加显著。结论:在体外环境下,吉西他滨联合卡铂可抑制SNK 6细胞增殖并诱导其凋亡,且一定浓度的吉西他滨联合卡铂对SNK 6细胞株的凋亡率与吉西他滨联合顺铂相似。     

Multidrug resistance protein 1 (MRP1, ABCC1) mediates resistance to mitoxantrone via glutathione-dependent drug efflux

Based upon several previous reports, no consistent relationship between multidrug resistance protein 1 (MRP1, ABCC1) expression and cellular sensitivity to mitoxantrone (MX) toxicity can be ascertained; thus, the role of MRP1 in MX resistance remains controversial. The present study, using paired parental, MRP1-poor, and transduced MRP1-overexpressing MCF7 cells, unequivocally demonstrates that MRP1 confers resistance to MX cytotoxicity and that resistance is associated with reduced cellular accumulation of MX. This MRP1-associated reduced accumulation of MX was partially reversed by treatment of cells with 50 microM MK571 [3-[[3-[2-(7-chloroquinolin-2-yl)vinyl]phenyl]-(2-dimethylcarbamoylethylsulfanyl)methylsulfanyl] propionic acid]-an MRP inhibitor that increased MX accumulation in MRP1-expressing MCF7 cells but had no effect on MRP-poor MCF7 cells. Moreover, in vitro experiments using inside-out membrane vesicles show that MRP1 supports ATP-dependent, osmotically sensitive uptake of MX. Unlike ABCG2 (breast cancer resistance protein, mitoxantrone-resistant protein), MRP1-mediated MX transport is dependent upon the presence of glutathione or its S-methyl analog. In addition, MX stimulates transport of [3H]glutathione. Together, these data are consistent with the interpretation that MX efflux by MRP1 involves cotransport of MX and glutathione. The results suggest that MRP1-like the alternative MX transporters ABCG2 and ABCB1 (MDR1, P-glycoprotein)-can significantly influence tumor cell sensitivity to and pharmacological disposition of MX.     

Functional role of arginine 375 in transmembrane helix 6 of multidrug resistance protein 4 (MRP4/ABCC4)

Multidrug resistance protein (MRP) 4 transports a variety of endogenous and xenobiotic organic anions. MRP4 is widely expressed in the body and specifically localized to the renal apical proximal tubule cell membrane, where it mediates the excretion of these compounds into urine. To characterize the MRP4 substrate-binding site, the amino acids Phe368, Phe369, Glu374, Arg375, and Glu378 of transmembrane helix 6, and Arg998 of helix 12, localized in the intracellular half of the central pore, were mutated into the corresponding amino acids of MRP1 and MRP2. Membrane vesicles isolated from human embryonic kidney 293 cells overexpressing these mutants showed significantly reduced methotrexate (MTX) and cGMP transport activity compared with vesicles that expressed wild-type MRP4. The only exception was substitution of Arg375 with serine, which had no effect on cGMP transport but significantly decreased the affinity of MTX. Substitution of the same amino acid with a positively charged lysine returned the MTX affinity to that of the wild type. Furthermore, MTX inhibition of MRP4-mediated cGMP transport was noncompetitive, and the inhibition constant was increased by introduction of the R375S mutation. A homology model of MRP4 showed that Arg375 and Arg998 face right into the central aqueous pore of MRP4. We conclude that positively charged amino acids in transmembrane helices 6 and 12 contribute to the MRP4 substrate-binding pocket.     

白细胞介素-10和天花粉蛋白抑制抗原提呈细胞表面分子表达及T-细胞增殖(英文)

目的:探明IL-10和天花粉蛋白的免疫抑制作用,为其临床应用提供理论依据,方法:APC表面分子经荧光染色用FACS分析结果,用~3H-TdR掺入法测定T-细胞增殖,巢式RT-PCR检测B7-1mRNA的表达,结果:IL-10和天花粉蛋白均能显著抑制B7-1分子的表达,两者对ICAM-1的表达未显示抑制作用,IL-10和天花粉蛋白对CD40的表达未见影响,但皆抑制LFA-1的表达,IL-10和天花粉蛋白处理过的APC未检测到B7-1 mRNA的表达,IL-10和天花粉蛋白都能抑制T-细胞的增殖(P<0.01)和IL-2的产生(P<0.01),结论:IL-10和天花粉蛋白抑制APC多种表面分子表达并抑制T-细胞增殖。     

SET protein overexpression contributes to paclitaxel resistance in MCF-7/S cells through PI3K/Akt pathway

Patient SE translation (SET) is a carcinogen in facilitating cellular growth and proliferation, and promoting tumorigenesis and metastasis. The present study was to investigate the resistance mechanisms associated with SET in paclitaxel-induced human breast cancer cells. The different expressions of SET, ATP-binding cassette (ABC) transporters and PI3K/Akt pathway between paclitaxel sensitive MCF-7/S and paclitaxel resistant MCF-7/PTX cells were identified using western blotting. We adopted plasmid transfection to upregulate SET in MCF-7/S cells and a novel SET antagonist COG112 to decrease SET in MCF-7/PTX cells. Subsequently, cell viability to paclitaxel was assessed by MTT assay and cell apoptosis was analyzed by flow cytometry. We found that levels of SET, ABC transporters and PI3K/Akt pathway were elevated in MCF-7/PTX. Upregulation of SET in MCF-7/S cells expressed resistant to paclitaxel and decreased cell apoptosis. Moreover, overexpression of SET promoted the mRNA and protein level of ABC transporters and PI3K/Akt signal pathway in MCF-7/S cells. Conversely, decreased level of SET by COG112 not only significantly sensitized MCF-7/PTX cells to paclitaxel, but also enhanced paclitaxel-induced cell apoptosis. Additionally, the levels of the ABC transporters and PI3K/Akt signal pathway were also reduced in the COG112-treated MCF-7/PTX cells. The above results demonstrated that SET was associated with paclitaxel resistance in MCF-7/PTX cells.     

Multidrug resistance protein 4 (MRP4/ABCC4): a versatile efflux transporter for drugs and signalling molecules

Multidrug resistance protein (MRP) 4 is a member of the MRP/ABCC subfamily of ATP-binding cassette transporters, which are capable of pumping a wide variety of endogenous and xenobiotic organic anionic compounds out of the cell. In addition to its role in the body distribution and renal excretion of a wide variety of antiviral, cytostatic, antibiotic and cardiovascular drugs, MRP4/ABCC4 has the remarkable ability to transport molecules involved in cellular signalling. These molecules include cyclic nucleotides, eicosanoids, urate and conjugated steroids. The unique structure, regulation and dual localisation of MRP4 in polarised cells could be connected with a key function in cellular protection and extracellular signalling pathways. This review focuses on recent insights into the versatile transport function of MRP4 and its potential as a new therapeutic target to modulate various pathophysiological signalling processes.     

白细胞介素—10和天花粉蛋白抑制抗原提呈细胞表面分子表达及T—细？…

AIM: To study immunoinhibitory effects and preliminary mechanism of IL-10 and trichosanthin. METHODS: Surface molecule expression on antigen processing cells (APC) was stained with fluorescence and analyzed by FACScan. B7-1 mRNA expression was detected with nested RT-PCR. RESULTS: IL-10 2 mg.L-1 and trichosanthin 10 mg.L-1 inhibited B7-1 molecule expression. By contrast, they had not the same effects on ICAM-1. IL-10 and trichosanthin down-regulated LFA-1 expression, but had no regulatory effect on CD40. IL-10 and trichosanthin dramatically inhibited T-cell proliferation and IL-2 production. B7-1 mRNA expression was undetectable in APC treated with IL-10 and trichosanthin. CONCLUSION: IL-10 and trichosanthin inhibit surface molecule expression on APC. They exert multiple immunoinhibitory effects.     

Multidrug resistance protein 1 (ABCC1) confers resistance to arsenic compounds in human myeloid leukemic HL-60 cells

Arsenic trioxide (As₂O₃) is established as one of the most effective drugs for treatment of patients with acute promyelocytic leukemia, as well as other types of malignant tumors. However, HL-60 cells are resistant to As₂O₃, and little is known about the underlying resistance mechanism for As₂O₃ and its biomethylation products, namely, monomethylarsonous acid (MMA^III) on the treatment of tumors. In the present study, we investigated the molecular mechanisms underlying iAs^III and its intermediate metabolite MMA^III-induced anticancer effects in the HL-60 cells. Here, we show that the HL-60 cells exhibit resistance to inorganic iAs^III (IC₅₀ = 10 μM), but are relatively sensitive to its intermediate MMA^III (IC₅₀ = 3.5 μM). Moreover, we found that the multidrug resistance protein 1 (MRP1), but not MRP2, is expressed in HL-60 cells, which reduced the intracellular arsenic accumulation, and conferred resistance to inorganic iAs^III and MMA^III. Pretreatment of HL-60 with MK571, an inhibitor of MRP1, significantly increased iAs^III and MMA^III-induced cytotoxicity and arsenic accumulations, suggesting that the expression of MRP1/4 may lead to HL-60 cells resistance to trivalent arsenic compounds.     

Newer developments in adult T-cell leukemia/lymphoma therapeutics

INTRODUCTION: Adult T-cell leukemia/lymphoma (ATL) is a rare disease with a unique geographic distribution. Conducting controlled randomized trials to assess the effective therapeutic strategies has therefore been a significant challenge to date. AREAS COVERED: This review explores the natural history and diagnostic evaluation of ATL, followed by a focused review of existing studies on the most potent individual pharmaceutical agents and combinations used in the therapy of this malignancy. Readers will acquire considerable insights about the clinical subsets, diagnosis and the most effective therapies used in various ATL types. EXPERT OPINION: International, multicenter, randomized clinical trials are essential to design optimal therapeutic strategies for various ATL subsets. It appears that patients with acute ATL type benefit considerably from the first-line combined antiviral therapy with zidovudine and interferon alpha, whereas patients with ATL of the lymphoma type may experience a better outcome with intensive chemotherapy. The role of therapy in smoldering and chronic disease types remains to be clarified. In addition, the results of allogeneic stem-cell transplantation in ATL appear promising, as up to 40% of patients who achieve remission and have suitable donors can now become long-term survivors. Prospective evaluation of novel effective agents and their incorporation into various therapeutic algorithms is stringently needed.     

Newer developments in adult T-cell leukemia/lymphoma therapeutics

Introduction: Adult T-cell leukemia/lymphoma (ATL) is a rare disease with a unique geographic distribution. Conducting controlled randomized trials to assess the effective therapeutic strategies has therefore been a significant challenge to date.

Areas covered: This review explores the natural history and diagnostic evaluation of ATL, followed by a focused review of existing studies on the most potent individual pharmaceutical agents and combinations used in the therapy of this malignancy. Readers will acquire considerable insights about the clinical subsets, diagnosis and the most effective therapies used in various ATL types.

Expert opinion: International, multicenter, randomized clinical trials are essential to design optimal therapeutic strategies for various ATL subsets. It appears that patients with acute ATL type benefit considerably from the first-line combined antiviral therapy with zidovudine and interferon alpha, whereas patients with ATL of the lymphoma type may experience a better outcome with intensive chemotherapy. The role of therapy in smoldering and chronic disease types remains to be clarified. In addition, the results of allogeneic stem-cell transplantation in ATL appear promising, as up to 40% of patients who achieve remission and have suitable donors can now become long-term survivors. Prospective evaluation of novel effective agents and their incorporation into various therapeutic algorithms is stringently needed.     

IL-10抑制脂多糖诱导的Hela细胞IL-15和IL-6转录

目的研究IL-10对脂多糖(LPS)诱导的Hela细胞IL-15mRNA和IL-6 mRNA表达的影响,分析其激活的信号转导通路。方法培养的Hela细胞,经不同浓度的LPS及IL-10单独或联合处理后,提取细胞总RNA和总蛋白,RT-PCR分析IL-15和IL-6转录水平的变化,Westernblot分析信号转导通路蛋白变化。结果RT-PCR分析得知①1ng～10μgLPS刺激Hela细胞12h后,IL-15 mRNA和IL-6 mRNA水平均明显上调(与对照组比较:P<0.01),且存在剂量依赖关系,100ng/mL时达峰值;100ng/mLLPS刺激Hela细胞0～24h,IL-15 mRNA和IL-6 mRNA水平亦明显上调(与对照组比较:P<0.01),24h内存在时间依赖关系,12h时达峰值。②单独IL-10(10ng/mL)作用于Hela细胞12h后,IL-15 mRNA和IL-6 mRNA没有明显变化(与对照组比较:P>0.05)。不同浓度的IL-10(1,10,100ng/mL)均下调100ng/mLLPS诱导的Hela细胞IL-15 mRNA和IL-6 mRNA的表达,且浓度越高IL-10抑制作用越明显。Western blot分析显示LPS主要通过磷酸化信号蛋白PI3K/AKT和ERK1/2上调IL-15和IL-6转录,IL-10能阻断AKT的磷酸化而对ERK1/2的磷酸化没有影响。结论IL-10可抑制LPS诱导的炎症细胞因子IL-15和IL-6的转录,这可能与其阻断AKT的磷酸化有关,因而,IL-10可能应用于某些临床感染性疾病的预防和治疗。     

Par-4 downregulation confers cisplatin resistance in pancreatic cancer cells via PI3K/Akt pathway-dependent EMT

Cisplatin (CDDP) efficiency in pancreatic cancer therapy is limited due to development of drug resistance. However, the comprehensive mechanisms remain largely unclear. In this study, we first established a CDDP-resistant pancreatic cancer cell line-BXPC-3/CDDP from its parental cell line-BXPC-3. The results showed that CDDP resistance in BXPC-3/CDDP cells correlates with changes in cellular EMT phenotypes. Prostate apoptosis response-4 (Par-4) expression at both mRNA and protein levels were reduced in CDDP-resistant BXPC-3/CDDP cells compared with that in BXPC-3 cells. Ectopic expression of Par-4 reversed EMT and CDDP resistance in BXPC-3/CDDP cells. In BXPC-3 cells, knockdown of Par-4 expression induces EMT and CDDP insensitivity, however, these effects were blocked by inhibition of PI3K/Akt pathway using LY294002. Furthermore, Par-4 knockdown could significantly stimulate PI3K/Akt signaling in BXPC-3 cells. In vivo studies, xenograft BXPC-3 tumors were sensitive to CDDP treatment. Treatment with CDDP alone had little effect on the growth of Par-4 siRNA-transfected BXPC-3 tumors in nude mice and the survival rate compared with control. Inhibition of PI3K/Akt pathway using LY294002 reversed CDDP resistance in Par-4 siRNA-transfected BXPC-3 tumors. In conclusion, these results indicate that Par-4 downregulation confers CDDP resistance via PI3K/Akt pathway-dependent EMT in BXPC-3 cells. Therefore, Par-4 may be a potential target for overcoming CDDP resistance in pancreatic cancer.     

Toll-like receptor 4 contributes to vascular remodelling and endothelial dysfunction in angiotensin II-induced hypertension

Background and Purpose

Toll-like receptor 4 (TLR4) signalling contributes to inflammatory cardiovascular diseases, but its role in hypertension and the associated vascular damage is not known. We investigated whether TLR4 activation contributed to angiotensin II (AngII)-induced hypertension and the associated vascular structural, mechanical and functional alterations.

Experimental Approach

AngII was infused (1.44 mg·kg⁻¹·day⁻¹, s.c.) for 2 weeks in C57BL6 mice, treated with a neutralizing anti-TLR4 antibody or IgG (1 μg·day⁻¹); systolic BP (SBP) and aortic cytokine levels were measured. Structural, mechanical and contractile properties of aortic and mesenteric arterial segments were measured with myography and histology. RT-PCR and Western blotting were used to analyse these tissues and cultured vascular smooth muscle cells (VSMC) from hypertensive rats (SHR).

Key Results

Aortic TLR4 mRNA levels were raised by AngII infusion. Anti-TLR4 antibody treatment of AngII-treated mice normalised: (i) increased SBP and TNF-α, IL-6 and CCL2 levels; (ii) vascular structural and mechanical changes; (iii) altered aortic phenylephrine- and ACh-induced responses; (iv) increased NOX-1 mRNA levels, superoxide anion production and NAD(P)H oxidase activity and effects of catalase, apocynin, ML-171 and Mito-TEMPO on vascular responses; and (v) reduced NO release and effects of L-NAME on phenylephrine-induced contraction. In VSMC, the MyD88 inhibitor ST-2825 reduced AngII-induced NAD(P)H oxidase activity. The TLR4 inhibitor CLI-095 reduced AngII-induced increased phospho-JNK1/2 and p65 NF-κB subunit nuclear protein expression.

Conclusions and Implications

TLR4 up-regulation by AngII contributed to the inflammation, endothelial dysfunction, vascular remodelling and stiffness associated with hypertension by mechanisms involving oxidative stress. MyD88-dependent activation and JNK/NF-κB signalling pathways participated in these alterations.