Epigenetic regulation of PAX5 expression in acute T-cell lymphoblastic leukemia

The analysis of genomic alterations in acute lymphoblastic leukemia (ALL) has provided new insights for prognosis and possible targets of novel therapies. In T-ALL the role of molecular abnormalities has still to be determined. Deregulated promoter hypermethylation of critical genes like PAX5 may have a significant impact on the course of ALL. Samples derived from 75 patients with ALL (B-ALL = 24, T-ALL = 51) and from healthy volunteers were analyzed. PAX5 expression was assessed by micro-array analysis (HG-U133plus 2.0) and correlated with promoter CpG island methylation of PAX5 using a pyrosequencing approach. The analyzed CpG marks in the promoter region of PAX5 were completely and uniformly unmethylated in the control group of healthy individuals. The T-ALL cases featured even higher methylation levels (median: 20%) with a strong variation of values of up to 85% methylation. Analysis of the association of altered methylation levels with gene expression data indicated a differential epigenetic regulation of PAX5 through promoter methylation which may contribute to the pathogenesis of this disease.     

Single agent BMS-911543 Jak2 inhibitor has distinct inhibitory effects on STAT5 signaling in genetically engineered mice with pancreatic cancer

The Jak/STAT pathway is activated in human pancreatic ductal adenocarcinoma (PDAC) and cooperates with mutant Kras to drive initiation and progression of PDAC in murine models. We hypothesized that the small-molecule Jak2 inhibitor (BMS-911543) would elicit anti-tumor activity against PDAC and decrease immune suppressive features of the disease. We used an aggressive genetically engineered PDAC model with mutant KrasG12D, tp53R270H, and Brca1 alleles (KPC-Brca1 mice). Mice with confirmed tumor burden were treated orally with vehicle or 30 mg/kg BMS-911543 daily for 14 days. Histologic analysis of pancreata from treated mice revealed fewer foci of adenocarcinoma and significantly decreased Ki67⁺ cells versus controls. In vivo administration of BMS-911543 significantly reduced pSTAT5 and FoxP3 positive cells within the pancreas, but did not alter STAT3 phosphorylation. Continuous dosing of KPC-Brca1 mice with BMS-911543 resulted in a median survival of 108 days, as compared to a median survival of 87 days in vehicle treated animals, a 23% increase (p = 0.055). In vitro experiments demonstrated that PDAC cell lines were poorly sensitive to BMS-911543, requiring high micromolar concentrations to achieve targeted inhibition of Jak/STAT signaling. Similarly, BMS-911543 had little in vitro effect on the viability of both murine and human PDAC-derived stellate cell lines. However, BMS-911543 potently inhibited phosphorylation of pSTAT3 and pSTAT5 at low micromolar doses in human PBMC and reduced in vitro differentiation of Foxp3⁺ T regulatory cells. These results indicate that single agent Jak2i deserves further study in preclinical models of PDAC and has distinct inhibitory effects on STAT5 mediated signaling.     

IL-6/STAT3信号传导通路及其在肿瘤靶向治疗中的作用

白细胞介素-6(IL-6)与肿瘤患者的分期、预后、转归以及对化疗药物的敏感性有关,且在患者的肿瘤组织及血清中常呈过表达.IL-6主要通过介导信号转换和转录激活因子3(STAT3)信号传导通路(IL-6/STAT3信号传导通路)来调节肿瘤细胞的增殖和分化.因此,IL-6/STAT3信号传导通路的阻断,对肿瘤具有潜在治疗意...     

ｓｉＲＮＡ沉默ＳＴＡＴ５对ＨｅＬａ细胞增殖和凋亡的影响及分子机制

目的：研究ＳＴＡＴ５对宫颈癌ＨｅＬａ细胞生物学特性的影响及其分子机制。方法：用ＭＴＴ法测定ＳＴＡＴ５ｓｉＲＮＡ对ＨｅＬａ细胞增殖的影响,流式细胞仪检测ＳＴＡＴ５ｓｉＲＮＡ对ＨｅＬａ细胞周期和细胞凋亡的影响,用Ｗｅｓｔｅｒｎｂｌｏｔ和ＲＴ- ＰＣＲ分析ＳＴＡＴ５、Ｂｃｌ-２和ｐ５３的变化。结果：ＳＴＡＴ５ｓｉＲＮＡ能够抑制ＨｅＬａ细胞的增殖,Ｓ和Ｇ２／Ｍ期肿瘤细胞比例减少,Ｇ０／Ｇ１期肿瘤细胞比例显著增加（Ｐ＜０.０１）,并诱导肿瘤细胞凋亡（Ｐ＜０.０１）。ＳＴＡＴ５ｓｉＲＮＡ下调ＳＴＡＴ５、Ｂｃｌ-２表达且上调ｐ５３表达。结论：ＳＴＡＴ５ｓｉＲＮＡ可以有效地诱导肿瘤细胞的凋亡,并抑制肿瘤细胞的增殖。     

STAT5、VEGF 和 EGFR 在非小细胞肺癌中表达的相关研究

目的：检测信号转导与转录激活因子5（STATS）、血管内皮生长因子（VEGF）和表皮生长因子受体（EGFR）在非小细胞肺癌（NSCLC）中的表达情况,探讨三者与NSCLC临床病理特征之间的关系。方法：采用免疫组化（sP）法检测62例NSCLC及30例癌旁正常对照组织中STAT5、VEGF和EGFR的表达情况。结果：STAT5、VEGF及EGFR在NSCLC组织中的阳性表达明显高于肺正常组织（P〈0．05）;STAT5阳性表达与NSCLC分化程度、有／无淋巴结转移及TNM分期无关（P〉0．05）,而与组织学类型有关（P〈0．05）;EGFR阳性表达与NSCLC组织学类型、分化程度无关（P〉0．05）,而与有／无淋巴结转移及TNM分期有关（P〈0．05）;VEGF阳性表达与NSCLC组织学类型无关（P〉0．05）,而与分化程度、有／无淋巴结转移及TNM分期有关（P〈0．05）。结论：STATS、VEGF及EGFR可能在肺癌的发生、侵袭和转移中起重要的作用,抑制其过度表达可望成为阻止肿瘤细胞的生长和转移的新靶点。     

Aberrant phosphorylation of STAT5 by granulocyte-macrophage colony-stimulating factor in infant cytomegalovirus infection mimicking juvenile myelomonocytic leukemia

Juvenile myelomonocytic leukemia (JMML) progenitor cells exhibit in vitro hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF). Phospho-specific flow cytometry using anti-phosphorylated STAT5 antibody is a new method recently reported to detect GM-CSF hypersensitivity of cells. However, colony assays using methylcellulose medium to measure GM-CSF-hypersensitivity remain as the current gold standard. Interestingly, cytomegalovirus (CMV) infection in infancy often presents with a variety of clinical symptoms that mimic JMML, with CMV giving a positive result by colony assay. We wanted to determine whether aberrant STAT5 activation occurs in CMV infection by using phospho-specific flow cytometry, and to ascertain whether this method is effective at discriminating CMV infection from JMML. Peripheral blood mononuclear cells from patients with JMML and CMV infection displayed an elevated proportion of p-STAT5 cells after low-dose GM-CSF stimulation when compared with cells from normal individuals. However, we found no significant differences in the percentage of p-STAT5 positive cells from patients with CMV infection and JMML at any doses of the GM-CSF doses used. We conclude that patients with CMV infection cannot be discriminated from patients with JMML by this new diagnostic method.     

STAT5和c-myc在大肠癌中的表达及意义

目的探讨大肠癌中STAT5和c-myc蛋白表达与肿瘤病理特征的关系及两者的相关性。方法采用免疫组织化学SP法检测56例大肠癌组织STAT5和c-myc蛋白的表达,同时选取16例大肠腺瘤组织作对照。结果STAT5在结肠癌组织中的阳性表达率（34/56,60.7%）明显高于大肠腺瘤组织（3/16,18.8%）,P<0.01。STAT5表达与肿瘤Dukes临床分期及淋巴结转移均呈正相关（P<0.05）。c-myc在结肠癌组织中的阳性表达率（35/56,62.5%）明显高于大肠腺瘤组织（4/16,25.0%）,P<0.01。c-myc表达与肿瘤分化程度、Dukes临床分期及淋巴结转移等均无明显相关（P>0.05）。STAT5和c-myc在大肠癌中表达呈正相关(r=0.359,P<0.01)。结论STAT5和c-myc在大肠癌的发生发展中起重要作用;STAT5检测可作为判断大肠癌恶性程度的指标;大肠癌中c-myc表达可能受STAT5调控。     

PAX5 alterations in an infant case of KMT2A‐rearranged leukemia with lineage switch

Lineage switch is a rare event at leukemic relapse. While mostly known to occur in KMT2A‐rearranged infant leukemia, the underlying mechanism is yet to be depicted. This case report describes a female infant who achieved remission of KMT2A‐MLLT3‐rearranged acute monocytic leukemia, but 6 months thereafter, relapsed as KMT2A‐MLLT3‐rearranged acute lymphocytic leukemia. Whole exome sequencing of the bone marrow obtained pre‐post lineage switch revealed two somatic mutations of PAX5 in the relapse sample. These two PAX5 alterations were suggested to be loss of function, thus to have played the driver role in the lineage switch from acute monocytic leukemia to acute lymphocytic leukemia.     

DNA damage induces the IL-6/STAT3 signaling pathway, which has anti-senescence and growth-promoting functions in human tumors

IL-6 is a multifunctional cytokine that is important for immune responses, cell survival, apoptosis, and proliferation. However, little is known about the correlation between the IL-6 signaling pathway and DNA damage in human tumors. The present study demonstrates the role of the IL-6/STAT3 signaling pathway in human tumor cells exposed to DNA damage. Tumor cells exposed to DNA damage increase the expression and secretion of IL-6 and the phosphorylation of JAK1 and STAT3. The activation of the JAK1-STAT3 signaling pathway is inhibited by knockdown of gp130 or neutralization of soluble IL-6, implying that DNA damage induces the phosphorylation of JAK1 and STAT3 by autocrine IL-6. Interestingly, inhibition of the IL-6/STAT3 signaling pathway impairs the growth of tumor cells exposed to DNA damage and results in the induction of senescence. Therefore, the present study suggests that IL-6 inhibits senescence but promotes the survival and proliferation of tumor cells exposed to DNA damage through the activation of the JAK1-STAT3 signaling pathway.     

白细胞介素-6/信号转导和转录激活因子3信号通路在大细胞肺癌NL9980细胞系增殖中的作用及机制

背景与目的：白细胞介素-6/信号转导和转录激活因子3(IL-6/STAT3)信号通路在很多恶性肿瘤中存在过度激活及表达,包括白血病、头颈部鳞状细胞癌多发性黑色素瘤、乳腺癌以及前列腺癌等,但其在大细胞肺癌中的研究少见。该研究旨在探索大细胞肺癌NL9980细胞系中IL-6/STAT3信号通路在细胞增殖中的作用及其机制。方法：将外源性IL-6设立5个浓度梯度(终浓度分别为0、1.0、5.0、10.0和20.0 ng/mL),分别对NL9980细胞系进行干预。运用噻唑蓝(MTT)法观察细胞增殖活力改变,并确立IL-6干预的最佳浓度。采用RT-PCR技术检测IL-6/STAT3相关基因及其下游调控基因Bcl-2、VEGF和CYCD1的mRNA表达量,并将IL-6/STAT3相关基因与下游基因做相关性分析。结果：外源性IL-6可促进NL9980细胞系的增殖,其最佳干预浓度为5 ng/mL(F=8.11,P<0.05)。信号通路相关基因IL-6及STAT3的mRNA表达量均以5 ng/mL组最高,分别为4.78±0.09和5.17±0.05(P<0.05);下游调控基因中,Bcl-2、VEGF及CYCD1的mRNA表达量均在5 ng/mL组最高,分别为4.52±0.14、4.12±0.12和3.98±0.17,其余浓度组与对照组相比,差异无统计学意义(P>0.05)。相关性分析表明,下游基因中Bcl-2、VEGF、CYCD1与IL-6(r=0.952,r=0.836,r=0.880)和STAT3(r=0.995,r=0.746,r=0.800)呈正相关性。结论：IL-6可促进大细胞肺癌NL9980细胞系的增殖,其机制可能是通过活化IL-6/STAT3信号通路并上调相关基因Bcl-2、VEGF和CYCD1的表达来实现的。