The down-regulation of alpha-interferon receptors in human lymphoblastoid cells: relation to cellular responsiveness to the antiproliferative action of alpha-interferon

Human lymphoblastoid cell lines (Daudi, Daudi subclones, Raji and MOLT-4) were compared for sensitivity to the antiproliferative action of alpha-interferon (IFN-alpha) and down-regulation of IFN-alpha receptors. IFN-sensitive and IFN-resistant cell lines have similar numbers (2-4000/cell) of high affinity (20-75 pM) IFN-alpha receptors. Treatment of IFN-sensitive cells with low concentrations (3-10 pM) of IFN-alpha results in low receptor occupancy and nearly complete (greater than 95%) down-regulation of cell surface IFN-alpha receptors within 5 h. Treatment of resistant cells with higher IFN concentrations (30 pM) only results in partial (approximately 60%) receptor down-regulation that is directly related to receptor occupancy. Receptor-receptor interactions, induced by IFN-alpha binding, may account for the enhanced down-regulation of IFN-alpha receptors in IFN-sensitive cells. Such interactions apparently do not occur in IFN-resistant lymphoblastoid cell lines.     

Effects of bacillus Calmette-Guérin and interferon-α-2B on human bladder cancer in vitro

The cytolytic and anti-proliferative effects of bacillus Calmette-Guérin (BCG) and/or interferon-α-2b (IFN-α-2b) on 5 human bladder carcinoma cell lines, RT4, RT112, MGH, SD and J82, were determined. The cell lines showed different sensitivities to BCG and IFN-α-2b. BCG had direct dose-dependent cytolytic and anti-proliferative effects on MGH, J82 and SD (grade 3 cell lines), whereas RT4 and RT112 (grades 1 and 2, respectively) were less sensitive. Surprisingly, higher concentrations of BCG enhanced cell growth of RT4. IFN-α-2b also had cytolytic and anti-proliferative effects on all 5 cell lines. Thus, the RT4 and RT112 cell lines that were not sensitive to BCG were highly sensitive to IFN-α-2b. A combination of BCG and IFN-α-2b had additive anti-proliferative effects on MGH, J82 and RT112. Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) production by these 5 cell lines was measured after stimulation with BCG and/or IFN-α-2b, by ELISA immunoassays. Production of IL-6 and TNF-α was significantly increased in MGH and J82 cell lines by the combination of BCG and IFNα-2b. The enhanced cytolytic and anti-proliferative effects of the combination of BCG and IFN-α-2b may be related to the induction of cytokines.Int. J. Cancer 71: 851-857, 1997. © 1997 Wiley-Liss Inc.     

干扰素α对恶性造血细胞系主要组织相容性复合体Ⅰ类链相关蛋白A表达的上调作用

目的观察干扰素a（IFN-a）对恶性造血细胞系主要组织相容性复合体（MHC）I类链相关蛋白A（MICA）表达的影响。方法反转录-聚合酶链反应（RT-PCR）法检测人类慢性髓系白血病细胞K562及人类伯基特淋巴瘤细胞Raji细胞MICAmRNA的表达,免疫组织化学法检测MICA蛋白的表达,四甲基偶氮唑蓝（MTF）比色法检测人类外周血自然杀伤（NK）细胞对肿瘤细胞的杀伤。结果K562细胞MICA表达阳性,Raji细胞MICA表达阴性。Raji和K562细胞分别在1000U／ml IFN-a诱导24h和48h时MICAmRNA开始表达上调（t=17．016,P〈0．05;t=5．616,P〈0．05）。72hRaji细胞和K562细胞分别在500U／ml和1000U／ml诱导条件下MICAmRNA表达开始上调（t=6．622,P〈0．05;t=9．071,P〈0．05）。IFN—Ot对MICAmRNA表达的上调作用呈一定时间和剂量依赖关系,且蛋白与mRNA表达水平一致。1000U／ml IFN—a诱导72h后,Raji细胞和K562细胞对NK细胞杀伤的敏感性明显上调（t=20．016,P〈0．05;t=7．969,P〈0．05）,抗MICA抗体封闭MICA后,NK细胞对Raji细胞杀伤率恢复至诱导前水平（t=0．393,P〉0．05）,而K562细胞则低于诱导前水平（t=9．841,P〈0．05）。结论IFN—a上调了恶性造血细胞中MICA基因的转录表达,继而增强了NK细胞对其识别与杀伤。     

Effects of interferon-α on human b cells: Repression of apoptosis and prevention of cell growth are independent responses of burkitt lymphoma lines

We have previously shown that interferon-α (IFN-α) can repress apoptosis in Burkitt lymphoma (BL) cells. In this study, we have compared this protective response with a further, well-established effect of IFN-α on BL cells, that of growth arrest. Of a panel of BL lines comprising (i) EBV-positive and -negative lines that retain the phenotype of the parental tumour cells and (ii) the prototype IFN-α-growth-inhibited line, Daudi, only Daudi cells were found to undergo substantial growth inhibition in response to the cytokine. By contrast, all lines, with the notable exception of Daudi, were protected by IFN-α from high-rate apoptosis initiated by the Ca²⁺ ionophore ionomycin. lonomycin failed to elicit an IFN-α-repressible apoptotic response in either wild-type Daudi cells or IFN-resistant sublines that were refractory to the growth-arresting effects of the cytokine. Analysis of c-myc protein levels confirmed previous observations that repression of apoptosis in IFN-α-rescuable BL cells was associated with an early inhibition of myc that was followed by a return to high-level expression. Significantly, ionomycin alone induced a comparable transient inhibition of myc protein in Daudi cells. In Daudi cells, but not in IFN-α-rescuable BL cells, renewed expression of myc observed after the early, transient down-regulation was followed by sustained down-regulation of the protein, which paralleled growth arrest. Our results indicate that long-term growth arrest and repression of apoptosis in BL are distinct cellular responses to IFN-α. © 1995 Wiley-Liss, Inc.     

HIF-1α对电离辐射诱导入非霍奇金淋巴瘤细胞凋亡作用及其机制的探讨

目的：探讨HIF-1α对电离辐射诱导入非霍奇金淋巴瘤（NHL）细胞凋亡的作用及其调控机制。方法：以HIF-1α抑制剂Echinomycin（EC）预处理人NHL细胞后给予5Gy X线照射,采用Annexin V染色方法检测肿瘤细胞凋亡水平的变化,采用蛋白质印迹法检测各细胞系中凋亡相关蛋白Bax、Bel-2和Caspase-3的表达水平。将HIF-1asiR—NA反义转染至NHL细胞中,检测转染后细胞凋亡分数及Caspase-3蛋白表达水平。结果：流式细胞仪检测结果显示,Namalwa细胞空白对照组、单纯照射组（RI）、RI＋EC 2nmol／L组的凋亡率分别为5．27±1．13、13．81±3．12和39．96±6．81,Ramos细胞分别为6．02±1．26、12．98±3．07和40．76±11．58,Raji细胞则为7．16±0．46、17．62±4．94和47．85±10．22,P〈0．01。电离辐射后,转染vector和HIF-1α siRNA的Namalwa细胞凋亡率分别为15．32±3．64和20．20±1．87,Ramos细胞分别为15．05±2．46和21．02±3．12,t值分别为3．99和3．19,P〈0．05;而Raji细胞则为10．90±1．65和17．26±0．69,t=5．98,P〈0．01。蛋白质印迹法结果显示,通过EC预处理抑制HIF-1α的表达能够明显上调射线诱导的各NHL细胞系中Caspase-3蛋白表达水平,同时凋亡相关蛋白Bcb2表达减低而Bax蛋白表达增加,Bcl-2／Bax比值明显降低,与单纯照射组相比差异均有统计学意义,P〈0．05。结论：抑制HIF-1α能够增加射线诱导的NHL细胞凋亡,其机制可能与增加Bax蛋白表达而下调Bcl-2蛋白表达有关。     

Synergistic antitumor effect of interferon-ß with gemcitabine in interferon-α-non-responsive pancreatic cancer cells

Interferon (IFN)-? is reported to have more potent antitumor effects than IFN-α. The aim of this study was to compare the synergistic antitumor activity of both IFNs when combined with gemcitabine on cultured pancreatic cancer cells expressing various levels of IFN receptor. The growth-inhibitory effects of IFN-α and IFN-? in combination with gemcitabine on three human pancreatic cancer cell lines (BxPC-3, MIAPaCa-2, Panc-1) were evaluated by MTT assay and isobolographic analysis. We also correlated their growth-inhibitory effects with the expression status of type I IFN receptor type 2 (IFNAR2). Western blot analysis indicated strong expression of IFNAR2 in BxPC-3 and MIAPaCa-2, but weak expression in Panc-1. The growth-inhibitory effect of gemcitabine was enhanced synergistically by IFN-α in BxPC-3 and MIAPaCa-2, but not in Panc-1. IFN-? exhibited more potent synergistic growth-inhibitory effects with gemcitabine in BxPC-3 and MIAPaCa-2 compared to IFN-α, and also synergistic enhancement in Panc-1. In conclusion, our results indicated that the growth-inhibitory effect of IFN-? with gemcitabine was synergistic not only in pancreatic cancer cells with strong expression of IFNAR2, but also in those with weak expression of IFNAR2.     

Somatic cell hybrids between human lymphoma lines. IV. Establishment and characterization of a P3HR-1/Daudi hybrid.

A new human B-lymphoma hybrid line designated DIP-1 was derived from the fusion of the Burkitt lines Daudi and P3HR-1. Cytogenetic analyses proved hybridity and showed that the hybrid was nearly complete from the chromosomal point of view. Hybridity was also confirmed by isozyme marker tests. The Daudi-derived IgM-kappa ring was fully exposed on DIP-1, together with the P3HR-1-derived human beta-2-microglobulin. Expression of C3 receptors was intermediate between the two parents and EBV receptors were some what reduced in comparison with both. The spontaneous low-level EBV antigen (EA and VCA) production of the parents was maintained and amplified in the hybrid. The hybrid, like its Daudi parent, was highly inducible with IdUrd. In P3HR-1 virus super-infection experiments, the Daudi parent was more permissive than the BU-P3HR-1 parent. The hybrid was intermediate, resembling the previously studied Raji/Daudi hybrid and contrasting with Raji/Namalwa and Raji/BJAB hybrids. Virus DNA replication patterns after P3HR-1 virus superinfection resembled the antigen pattern. The implication of these findings for the understanding of virus-host cell relationships and the regulation of the viral cycle is discussed The findings are meant to imply that genetically determined isozyme markers are autonomously expressed, as in other systems. Differentiation-related markers and EBV-cycle-related characteristics are autonomously expressed in some cases (surface immunoglobulin, beta-2-microglobulin, spontaneous EBV-production, IdUrd inducibility) and appear to be under a restrictive control in others (EA inducibility by P3HR-1 virus superinfection, C3 and EBV receptors, viral DNA replication).     

Somatic cell hybrids between human lymphoma lines. II. Spontaneous and induced patterns of the Epstein-Barr virus (EBV) cycle.

The regulation of spontaneous, IUDR-induced and P3HR-1 virus-induced EA and VCA production patterns was studied in two new somatic hybrids between human lymphoma lines. The hybrid 8A was derived from the crossing of the non-producer Raji with the spontaneous producer Daudi line. The second hybrid, 83, was produced by the fusion of Raji with the EBV-genome-negative B-lymphoma line, BJAB. The studies suggest the following EBV regulation patterns: (1) the spontaneous production of EA and VCA appears to be regulated by controls that differ from the regulators of P3HR-1 virus-induced or IUDR-induced EA synthesis. While spontaneous producer status was dominant over non-producer status, the level of EA inducibility was set by one of the parental cells, Raji ATG, and could either raise (in the previously studied Raji/Namalwa hybrid, cf Nyormoi et al. 1973) or depress (in Raji/Daudi) the level of relative EA inducibility found in the partner cell. (2) Although EA production is a prerequisite for VCA synthesis, the latter is under its own restriction mechanisms, quite independent of those that regulate the level of EA synthesis. (3) Inducibility of EA synthesis by P3HR-1 virus and by IUDR appear to be under the influence of at least partially identical controls. (4) EBV-negative lymphoma cells, exemplified by BJAB, may exert a "complementation" effect on the EA inducibility of their EBV-positive fusion partner, in spite of their own restrictivity against virus-induced EA synthesis. In more general terms, it is obvious that the EBV cycle is under the influence of multiple regulatory mechanisms in the human lymphoid cell. Depending on the parental cell and viral genomes that are allowed to interact, somatic cell hybrids may display a variety of patterns. At this time, cell hybridization is one of the few pathways that permit an approach to this complex and completely unknown world.     

NF-κBp65对人非霍奇金淋巴瘤细胞HIF-1α-VEGF途径调节及其机制的探讨

目的:研究NF-κB对人非霍奇金淋巴瘤(NHL)HIF-1α-VEGF途径的调控及其机制。方法:应用Echinomycin(EC)处理人NHL细胞,将HIF-1α反义质粒转染至肿瘤细胞中,采用蛋白质印迹法检测经两种方法处理后各细胞系中VEGF表达水平。以NF-κB特异性抑制剂quinazoline(QNZ)及Bay11-7082预处理人NHL细胞,检测各细胞系中HIF-1α蛋白的表达水平,同时采用实时定量PCR方法检测HIF-1αmRNA变化。应用QNZ处理NHL细胞后检测HIF-1α下游调控靶点VEGF的蛋白表达水平。结果:通过应用HIF-1α特异性抑制剂和转染反义质粒两种方法均能够抑制HIF-1α,明显下调了VEGF蛋白表达水平,与对照组相比差异均有统计学意义,P<0.05。NF-κB抑制剂QNZ及Bay11-7082能够降低NHL细胞HIF-1α蛋白及基因水平的表达,同时下调其下游调控靶点VEGF蛋白的表达,P<0.05。结论:抑制NF-κB可阻断人NHL细胞HIF-1α-VEGF通路,其机制可能与NF-κB调控HIF-1α的基因与蛋白表达有关。     

The effect of malignant epithelial tumors,surgical therapy,and bacterial sepsis upon various parameters of interferon system

The influence of tumor load, surgical trauma, and bacterial sepsis upon the ability of patient's peripheral leukocytes to produce interferon-α (IFN-α), the detectable serum IFN levels and circulating serum IFN inactivators were studied. Peripheral blood leukocytes of patients with solid tumors had significantly reduced ability to produce IFN-α. Complete resectional surgery resulted in restoration of their ability to produce normal IFN-α levels. Circulating IFN levels were detectable in 70% of patients with localized disease while only in 20% of patients with metastatic disease. Interferon-α activators were detected in 45% of all patients. Both circulating interferon and IFN-α inactivators became undetectable upon tumor resection. Surgical trauma is accompanied by a transient but definite decrease in IFN-α production capability. Bacterial sepsis during postoperative days, in patients who successfully recovered, was definitely accompanied by increase in IFN-α production capability. Our findings suggest that advanced malignant epithelial tumors have an adverse effect upon the patient's ability to produce interferon and are often accompanied by the presence of circulating serum interferon inactivators. These effects can be reversed by surgical resection of the malignant neoplasm.     

Stimulation of natural killer cell activity and inhibition of proliferation of various leukemic cells by purified human leukocyte interferon subtypes

One of several human leukocyte interferon subtypes A (LeIF-A), obtained in purified form from a gene cloned in Escherichia coli, stimulated human peripheral blood natural killer cell activity, whereas another human leukocyte interferon subtype D (LeIF-D) had no effect with the use of K562 as target cells. With Daudi as target cells, both LeIF-A and LeIF-D stimulated natural killer cell activity. A hybrid human leukocyte interferon, NH2-terminal 61 amino acids and COOH-terminal 104 residues of LeIF-A and LeIF-D, respectively (LeIF-AD) showed greater stimulation than did LeIF-A, but the stimulation did not exceed that of natural buffy coat interferon. A mixture of equal antiviral units of LeIF-A and LeIF-D was no more effective than was LeIF-A alone. The cloned interferon subtypes showed differential effects on the proliferation of three human leukemic cell lines: Daudi (B-cell lymphoblastoid leukemia); BALL 1 (B-cell acute lymphoblastic leukemia); CCRF-HSB-2 (T-cell acute lymphoblastoid leukemia). Growth of Daudi cells was generally most sensitive to all the interferons tested, LeIF-A, -D, -AD, and a buffy coat preparation; no viable cells remained after 120-hr exposure to 1000-unit/ml doses of the interferons. BALL 1 was relatively resistant to the interferon subtypes tested including LeIF-AD, but this cell lines was very sensitive to a preparation of natural buffy coat interferon. CCRF-HSB-2 showed some sensitivity to all the interferons with greatest sensitivity to LeIF-A (10% of the viable cells were detected after 1000 units/ml exposure for 120 hr). In contrast to the leukemic cell lines tested, human amnion cells (WISH) and the human erythroid leukemia, K562, were resistant to the antiproliferative activity of the interferons.     

Development of a novel interferon-α2b gene construct with a repetitive hypoxia-inducible factor binding site and its suppressive effects on human renal cell carcinoma cell lines in vitro

Background

Despite the advent of targeted therapies, interferon-alpha (IFN-α) remains a therapeutic option for advanced renal cell carcinoma (RCC), especially in Japan, with a treatment response rate of 15–20 %. To improve the efficacy of IFN-α-based therapies, we evaluated a novel treatment strategy for RCC using an IFN-α2b gene construct with a repetitive hypoxia-inducible factor binding site.

Methods

We constructed an expression plasmid designated 5HREp-IFN-α2b containing the coding region of the IFN-α2b gene. Five copies of the hypoxia-response element (HRE) sequences were inserted upstream of the IFN-α2b gene, and the construct was transfected into human RCC cell lines ACHN, 786-O and KU19-20. The concentrations of IFN-α2b in the conditioned media were measured by enzyme-linked immunosorbent assay. Cell viabilities were determined by MTS assays.

Results

Construct-induced IFN-α secretion was confirmed in all three cell lines. IFN-α production was significantly enhanced by the hypoxia-mimicking agent deferoxamine mesylate in cell lines expressing the wild-type von Hippel–Lindau (VHL) gene (KU19-20 and ACHN) compared with cells expressing the mutant VHL gene (786-O). The construct exerted significant suppressive effects on the viabilities of all RCC cell lines.

Conclusion

This is the first study to report on the construction of a cytokine gene with a repetitive hypoxia-inducible factor binding site and its application in the suppression of human cancer cells. Gene therapy using this IFN-α2b gene construct with HREs may represent a novel treatment modality for advanced RCC.     

Sensitivity to EBV superinfection and IUdR inducibility of hybrid cells formed between a sensitive and a relatively resistant Burkitt lymphoma cell line

The sensitivity of Burkitt lymphoma-derived cell lines to Epstein-Barr virus (EBV) superinfection and the inducibility of the latent EBV genome in these lines were studied by somatic cell hybridization. Two non-EBV producer lines; AG R3, an adherent, 8-azaguanine-resistant variant of the Rajiline; and Namalwa, a non-adherent, 8-azaguanine-sensitive line, were fused with the aid of β-propiolactone-inactivated Sendai virus. The resident EBV genome in Raji is inducible with 5-iododeoxyuridine and the line is also sensitive to EBV superinfection. Namalwa is relatively resistant to both super-infection and induction, and synthetizes surface-associated IgM-lambda. Cytological studies showed that hybrid cells appear to be much larger than either parent and attach to culture plates less firmly than the adherent Raji variant parent. Karyological analyses showed that hybrids contain the expected sum of the parental chromosome markers. Membrane immunofluorescence tests also showed that hybrids synthetize IgM. All the hybrid cells appear to be non-EBV producers, but they are sensitive to both EBV super-infection and induction of latent EBV. These findings suggest the following explanations: (1) there is no evidence of any complementation between the two non-EBV producer lines (Raji and Namalwa) to elicit spontaneous EBV production in hybrid cells; (2) Namalwa is deficient in some factors required for the synthesis of EBV-specified early antigens after EBV superinfection and after induction of latent EBV by IUdR; these factors are supplied by the Raji parent in the hybrids; or (3) Raji, Namalwa and hybrid cells or EBV all produce a substance which inhibits activation of a productive viral cycle, but whose action is antagonized in Raji and hybrid cells to allow the synthesis of EBV-specific early antigens.     

Induction of apoptotic cell death in non-melanoma skin cancer by interferon-α

Interferon-α (IFN-α) is a cytokine that is effective in the treatment of a variety of cancers, including non-melanoma skin cancers. The biologic responses of cells to IFN-α are pleiotropic and include growth suppression and immunomodulation. The potential direct effects of IFN-α on tumor cell populations are incompletely characterized. Our findings indicate that IFN-α can directly induce apoptosis (programmed cell death) in sensitive squamous cell skin cancer cell lines. Cell lines resistant to the cytotoxic effects of IFN-α showed no evidence of apoptosis induction. Transfection of IFN-α-sensitive cell lines with a bcl-2 expression vector conferred partial resistance to cell death induction by IFN-α Our results indicate that the clinical efficacy of IFN-α may, in part, be related to the ability of this cytokine to induce apoptosis. © 1995 Wiley-Liss, Inc.     

干扰素α调控维甲酸诱导基因G表达分子机制的新发现

目的 探讨干扰素α(IFN-α)调控维甲酸诱导基因G(RIG-G)表达调控的分子机制.方法 采用Western blot方法检测急性早幼粒白血病细胞系NB4经IFN-α处理后信号传导和转录活化因子1(STAT1)、p-STAT1和RIG-G蛋白的表达变化.采用细胞转染、报告基因实验、免疫共沉淀实验和染色质免疫沉淀实验等技术,研究STAT1缺失的U3A细胞中,STAT1、STAT2和IFN调节因子9(IRF-9)在IFN-α调控RIG-G基因表达中的作用及其机制.结果 在 U3A 细胞中,只有当STAT2和IRF-9共同转染时,RIG-G启动子荧光素酶报告基因的表达活性才明显升高,约为空载对照组的8倍.在无IFN-α作用时,野生型或突变型STAT2与IRF-9共同转染U3A细胞可产生相似的效应;但IFN-α能进一步增强野生型STAT2与IRF-9的转录激活作用,约为未加IFN-α时的6倍,而对突变型STAT2无效.STAT2能与IRF-9相互作用,并能与RIG-G基因的启动子结合.结论 STAT2和IRF-9能以不依赖于STAT1的形式发生相互作用,所形成的复合物是介导IFN-α调控RIG-G基因表达的关键性转录因子,这是一种有别于经典JAK-STAT途径的新的干扰素信号转导方式.     

Mutations of the von Hippel-Lindau gene confer increased susceptibility to natural killer cells of clear-cell renal cell carcinoma

The tumor suppressor gene von Hippel-Lindau (VHL) is involved in the development of sporadic clear-cell renal cell carcinoma (RCC). VHL interferes with angiogenesis and also controls cell adhesion and invasion. Therapies that target VHL-controlled genes are currently being evaluated in RCC patients. RCC is a immunogenic tumor and treatment with interleukin-2 (IL2) or interferon (IFN)-α results in regression in some patients. We used two renal tumor cell lines (RCC6 and RCC4) carrying VHL loss-of-function mutations to investigate the role of mutant VHL in susceptibility to natural killer (NK) cell-mediated lysis. The RCC6 and RCC4 cell lines were transfected with the wild-type gene to restore the function of VHL. The presence of the gene in RCC cells downregulated hypoxia-inducible factor (HIF)-1α and subsequently decreased vascular endothelial growth factor (VEGF) production. Relative to control transfectants and parental cells, pVHL-transfected cell lines activated resting and IL2-activated NK cells less strongly, as assessed by IFNγ secretion, NK degranulation and cell lysis. NKG2A, a human leukocyte antigen (HLA)-I-specific inhibitory NK receptor, controls the lysis of tumor targets. We show that HLA-I expression in RCC-pVHL cells is stronger than that in parental and controls cells, although the expression of activating receptor NK ligands remains unchanged. Blocking NKG2A/HLA-I interactions substantially increased lysis of RCC-pVHL, but had little effect on the lysis of VHL-mutated RCC cell lines. In addition, in response to IFNα, the exponential growth of RCC-pVHL was inhibited more than that of RCC-pE cells, indicating that VHL mutations may be involved in IFNα resistance. These results indicate that a decreased expression of HLA-I molecules in mutated VHL renal tumor cells sensitizes them to NK-mediated lysis. These results suggest that combined immunotherapy with anti-angiogenic drugs may be beneficial for patients with mutated VHL.     

Lack of interleukin-2 (IL-2) expression and selective expression of IL-10 mRNA in human renal cell carcinoma

Freshly isolated tumor-infiltrating lymphocytes (TIL) are often functionally deficient. Since one of the key functional parameters of an immune response is the local production of cytokines, we studied the expression of cytokine genes in freshly isolated renal cancer tissue. Using a PCR-assisted mRNA amplification assay, the constitutive expression of mRNA for 10 different cytokines was assessed in renal cancer tissue. We compared the cytokine mRNA expression in freshly isolated samples of renal carcinomas, renal cancer cell lines established from the tumor samples, peripheral blood mononuclear cells (PBMC) and non-tumor kidney tissue isolated from the same patients. IL-10 mRNA expression was detected only in tumor samples, while renal cancer lines, PBMC and non-tumorous kidney tissues were devoid of this cytokine. One-third of the tumor samples but none of the normal kidney samples also expressed G-CSF mRNA. IL-6, TNF-α and IFN-γ mRNA were expressed non-selectively in tumors, PBMC and normal renal tissue. Expression of IL-2, IL-3 and IL-4 mRNA was not detected in any of the tissues analyzed. Established renal cancer lines exhibited expression of IL-lα, IL-6, TNF-α and GM-CSF. Culture of tumor-derived T cells with anti-CD3 monoclonal antibody (MAb) resulted in expression of IL-2, IL-3 and IL-4 mRNA. In contrast, none of these cytokines was detected in culture with recombinant human IL-2 alone. Since IL-10 is known to suppress antigen presentation, these findings have important implications for the possible in vivo role of IL-10 as a suppressor of local anti-tumor response.     

EB病毒microRNA Bart6-5p表达对鼻咽癌上皮间质转化的影响

 目的 探讨EB病毒microRNA Bart6-5p表达对鼻咽癌细胞上皮间质转化（epithelial mesenchymal transition,EMT）的影响。方法 采用实时荧光定量PCR检测EB病毒阳性的鼻咽癌细胞株C666-1和淋巴瘤细胞株Akata、Daudi、Raji及Namalwa中microRNA Bart6-5p和Dicer mRNA的表达,在恒定携带EB病毒且microRNA Bart6-5p表达最高的鼻咽癌细胞株C666-1中抑制microRNA Bart6-5p表达后检测Dicer和与鼻咽癌EMT相关分子标志物E-cadherin、Vimentin、ZEB1和ZEB2 mRNA的表达。结果 EB病毒阳性细胞株中microRNA Bart6-5p mRNA表达水平按C666-1、Akata、Daudi、Raji及Namalwa顺序依次递减（P＜0.05）,而Dicer mRNA表达水平则依次递增（P＜0.05）。在恒定携带EB病毒且microRNA Bart6-5p表达最高鼻咽癌细胞株C666-1中抑制microRNA Bart6-5p表达后,Dicer mRNA表达呈升高趋势（P＜0.05）,与鼻咽癌EMT相关分子标志物E-cadherin mRNA表达呈升高趋势（P＜0.05）, Vimentin、ZEB1及ZEB2 mRNA表达则呈下降趋势（P＜0.05）。结论 EB病毒microRNA Bart6-5p可能通过调控Dicer基因表达而进一步影响鼻咽癌的上皮间质转化过程。