MKW, a novel hematopoietic antigen.

A novel hematopoietic antigen was identified using a murine monoclonal antibody raised against KG-1 cells. This antigen, termed MKW, was also detected on the surface of the monocytic cell line U937, but not on the K562, ML1, or HL-60 cell lines. On normal hematopoietic cells, the antigen is expressed on the surface of monocytic and myelocytic cells and on a subpopulation of B-cells. During normal hematopoiesis, the surface expression of MKW is greatest and occurs very early on monocytic cells. Alternatively, in myeloid cells, surface expression occurs later and cell maturation is correlated with increased surface expression. When U937 cells are induced to differentiate, surface expression is transiently up-regulated. Surface expression of MKW, however, does not appear to be an activation antigen since activation of purified T- or B-cells failed to increase MKW on the cell surface. Leukemic blasts from 22 of 80 children (27%) with acute myeloblastic leukemia and from 29 of 225 children (13%) with acute lymphoblastic leukemia expressed MKW on the cell surface. Although surface expression of MKW was absent on T-cell lines, peripheral T-cells, and most B-cells, the antigen was identified in the cytoplasm of some B-cells, T-cells, and cell lines. Immunoprecipitation studies showed that MKW is a 52-kDa protein whether expressed on the cell surface or in the cytoplasm, and it appears to be nonglycosylated. Furthermore, studies with phosphatidylinositol-phospholipase C suggested that MKW is not attached to a glycolipid anchor. The biochemical characterization of MKW and its pattern of expression are distinct from any of the previously identified CD groups or published antigens. Since this unique antigen has prognostic significance in leukemia and appears to be associated with cell differentiation, its exact role in hematopoiesis should be investigated.     

Immunological subtypes of childhood T-cell acute lymphoblastic leukemia and their prognostic significance

The data on examination and treatment of 39 children with T-cell acute lymphoblastic leukemia (T-ALL) were assessed; all patients received ALL BFM-90-M treatment. The fraction of children with T-ALL among ALL patients in Belarus was 12.2% (pre-T-ALL--15, cortical T-ALL--46 and mature T-ALL--23%). Also, a subtype of T-ALL with atypical expression of markers was identified (13%). Overall 7-year survival in T-ALL patients was 47(20%). The worst prognosis was recorded in the T-ALL subgroup with atypical expression of markers (p < 0.001 as compared with the other subgroups). As for outcome--from best to worst, T-ALL subtypes ranged as follows: cortical T-ALL, mature T-ALL, pre-T-ALL and T-ALL with atypical expression of markers.     

抗原处理相关转运因子在小儿急性白血病患者中的表达及其临床意义

背景与目的:抗原处理相关转运因子(transporterassociatedwithantigenprocessing,TAP)参与免疫监视,因而可能与肿瘤发生有关。本文旨在探讨急性白血病TAP分子表达及其临床意义,探讨急性白血病的治疗策略。方法:采用RT-PCR检测34例初治急性淋巴细胞白血病(acutelymphoblasticleukemia,ALL)(初治组)、15例复发ALL(复发组)及20例急性髓系白血病(acutemyeloidleukemia,AML)患者骨髓中TAP亚单位TAP1和TAP2的表达。20例无全身性疾病外科住院患儿作为对照组。使用数码成像分析仪测定并计算扩增条带的相对于阳性内对照GAPDH的吸光度(A)值。结果:ALL初治组和ALL复发组的TAP1A值(分别为0.448±0.167和0.169±0.021)及TAP2的A值(分别为0.196±0.180和0.112±0.020)均低于对照组,P均<0.01;AML组TAP2的A值低于对照组(P<0.01);ALL复发组TAP1的A值低于ALL初治组,P<0.05;ALL初治组复发者(6/34)TAP1的A值(0.215±0.159)较持续完全缓解(constantcompleteremission,CCR)者低(24/34,0.462±0.189,P<0.05)。结论:小儿ALL和AML均存在TAP分子低表达,这可能促使白血病细胞逃避免疫监视;TAP1亚单位低表达可能与ALL的复发有关。     

AC133 antigen as a prognostic factor in acute leukemia

AC133 is a novel 5-transmembrane antigen present on a CD34((bright)) subset of human hematopoietic stem cells (HSCs) and it is also expressed on the subset of CD34 positive (CD34(+)) leukemias. But the clinical significance of AC133 expression on leukemic blasts is not yet known. We investigated the expression of AC133 antigen on blast cells of acute leukemia. Forty-one cases of acute leukemia were examined for expression of AC133, CD34, and other antigens using multicolor flow-cytometry. Samples were considered positive if at least 20% of the cells specifically stained with monoclonal antibodies (MoAbs) revealed a higher fluorescence intensity compared to cells of corresponding negative control samples (=20% cut-off level). 14/36 (38.9%) acute myelogenous leukemia (AML) samples and 6/20 (30%) acute lymphoblastic leukemia (ALL) samples were positive for AC133, the difference was not significant. All AC133 positive (AC133(+)) leukemias expressed CD34, whereas 13 of 33 CD34(+) leukemias were negative for AC133, and AC133(+)/CD34(-) leukemia was not found. Expression rates of CD31, CD62L, CD62E, CD105 and CD144 were significantly higher in AC133(+) leukemia compared to those of AC133(-) leukemia (P=0.045, P<0.001, P<0.001, P<0.001, P=0.003, respectively), but bcl-2, CXCR-1, CXCR4, VLA-4, CD106 expression rates were not significantly different between AC133(+) and AC133(-) leukemias. None of the clinical prognostic markers such as age, hemogram, lactate dehydrogenase, and chromosomal aberration were significantly different between AC133(+) and AC133(-) leukemias. CR rates of AC133(+) AML and AC133(-) AML were not significantly different, although there was a trend toward higher CR rates in AC133(-) AML (18/22[81.8%] AC133(-) AML versus 9/14[64.3%] AC133(+) AML), but the 1-year relapse rate of AC133(+) AML was significantly higher than that of AC133(-) AML (8/9 (88.9%) versus 7/19 (36.8%), P=0.016). Median disease-free survival (DFS) times of AC133(+) and AC133(-) AML were significantly different (11 and 18 months, respectively, P=0.006), although overall survival (OS) times were not significantly different (AC133(+) 15 months versus AC133(-) 20 months, respectively, P=0.06). Similar results regarding clinical outcomes were found when AC133(+)/CD34(+) and AC133(-)/CD34(+) were analyzed separately, but the difference did not attain statistical significance. In ALL, 9/11 (81.8%) AC133(-) and 2/4 (50%) AC133(+) cases achieved CR, but the difference was not significant. Four of 11 AC133(-) ALL (36.4%) and 2 of 3 AC133(+) ALL (66.7%) relapsed within 1 year. In survival analysis, median DFS time and OS time of the AC133(+) group were 7 and 18 months, respectively, and these were not significantly different from those of the AC133(-) group (median DFS 15, OS 22 months, respectively). Our results demonstrate that AC133 expression in AML blasts is associated with poor clinical outcomes in terms of higher early relapse and shorter disease-free survival, suggesting that the AC133 antigen might provide the prognostic stratification of acute leukemia. However, to verify the effect of AC133 expression on the therapeutic outcomes of adult acute leukemia, further study including more cases is needed.     

miR-141在儿童急性B淋巴细胞白血病中的表达及意义

背景与目的：微小RNA(microRNA,miRNA)是一类长度为21~25 nt的内源性单链非编码RNA小分子。本研究旨在探讨miR-141在儿童急性B淋巴细胞白血病(acute lymphoblastic leukemia,ALL)中的表达及临床意义。方法：收集B细胞ALL患儿35例为B细胞ALL组,以非血液病患儿15例为对照组,采集骨髓标本,提取总RNA,采用real-time PCR检测miR-141的表达,比较各组miR-141表达差异。结果：miR-141在B细胞ALL组中的表达低于对照组(P<0.05);miR-141在治疗前的表达明显低于治疗第30天及第12周(P<0.05),治疗第30天的表达低于治疗第12周(P<0.05);≥10岁组miR-141的表达低于＜10岁组(P<0.05);低危组治疗前miR-141表达高于中、高危组(P<0.05),而中危组高于高危组(P<0.05)。结论：miR-141在儿童B细胞ALL中很可能存在抑癌作用,并是预后预测的潜在靶点。     

抗凋亡基因Aven在儿童急性淋巴细胞白血病中的表达及其临床意义

 目的　探讨抗凋亡基因Aven在儿童急性淋巴细胞白血病（ALL）中的表达及其与临床分型的关系。方法　应用RT-PCR检测55例儿童ALL患者Aven基因mRNA的表达水平,11例非恶性血液病患儿为对照组。结果　年龄≥10岁的ALL患者,Aven的表达明显高于年龄＜10岁者,复发患者Aven的表达亦明显高于未复发者。单变量和多变量分析结果均显示Aven的高表达为儿童ALL不利的预后因素。结论　Aven在儿童ALL中异常表达,且为不良的独立预后因素。     

WT1基因在儿童急性B淋巴细胞白血病中的表达及临床意义

目的:探讨WT1(Wilms tumor gene 1)基因在儿童急性B淋巴细胞白血病（B-ALL）中的表达及临床意义。方法:应用实时荧光定量PCR方法检测77例初诊B-ALL患儿WT1基因的相对表达水平,比较患者年龄、性别、流式亚型、染色体核型、临床危险分级等因素的基因表达差异,并随访分析初诊WT1基因表达水平对患儿预后的影响。结果:77例初诊B-ALL患者中,WT1基因阳性率96.10%（74/77）,0~2岁患儿初诊WT1水平高于3~13岁组（P=0.02）,WT1基因表达在性别上无统计学差异（P=0.229）。在对B-ALL流式亚型间WT1的分析中显示,Pro-B-ALL患者表达量最高,Pre-B-ALL次之,Com-B-ALL最低（两两比较差异,P值分别为0.002,0.008,0.040）。临床高危（P=0.041）、t(4;11）（P=0.034）、初诊白细胞大于50×109/L（P=0.009）的患者有更高的WT1表达。首次诱导化疗后细胞形态学缓解与否,其初诊时WT1表达无明显差异（P=0.84）,但长期随访得到持续缓解的患者初诊WT1表达低于复发或不缓解的患者。结论:WT1基因在儿童B-ALL中表达的高低可能提示患者白血病细胞的分化水平,并与长期预后相关。     

Incidence and prognostic significance of MDM2 oncoprotein overexpression in relapsed childhood acute lymphoblastic leukemia.

MDM2 overexpression by pediatric ALL cells at initial diagnosis has been linked to poor response to therapy. In the present study, we evaluated the incidence of MDM2 overexpression by ALL cells from pediatric patients at first relapse and compared MDM2 protein levels with in vitro response to adriamycin and with duration of initial complete remission (CR1). Since an important role of MDM2 in enhancing cell proliferation and survival appears to be inhibition of p53 activity, we also evaluated the status of p53 in these patients' leukemic cells. MDM2 protein levels were determined by Western blot analysis of leukemic bone marrow cells obtained from 42 patients with B cell precursor (BCP) ALL who relapsed during or following therapy on standard POG ALL protocols. Twelve of 42 (29%) cases have MDM2 levels >/=10-fold higher than those detected in normal bone marrow mononuclear (NMMC) cells, which express relatively low levels of protein. Thirty cases (71%) expressed MDM2 at levels <10-fold those in NMMC, including 24 MDM2-negative cases (57%). P53 mutations were detected by single-strand conformation polymorphism analysis in two cases. Overexpression of MDM2 (>/=10-fold) was significantly correlated with adriamycin resistance and decreased duration of CR1. Eight of 12 (75%) overexpressers showed high levels of in vitro resistance to adriamycin, compared to four of 30 (13%) non-overexpressers (P < 0.005). The median CR1 for MDM2 overexpressers was 20.5 months (range: 3-75 months) compared to 41 months (range: 8-98 months) for non-overexpressers (P < 0.01). Four of 42 patients failed to achieve CR following re-induction: leukemic cells from three of these patients either overexpressed MDM2 or contained a mutant p53. These results indicate that overexpression of MDM2 plays a significant role in refractory pediatric ALL and is associated with early relapse, adriamycin resistance, and failure to respond to re-induction therapy. Leukemia (2000) 14, 61-67.     

CD133在急性白血病中的表达

目的研究CD133与急性白血病FAB分型、免疫分型及细胞遗传学改变间的关系.方法对60例急性白血病患者骨髓标本进行细胞形态学及细胞化学检查,确定其FAB亚型;运用直接免疫荧光标记法检测CD133及系列相关免疫标记进行免疫分型;采用RHG法进行核型分析.结果CD133在急性髓性白血病(AML)及急性淋巴细胞性白血病(ALL)细胞膜上均可表达,且往往与CD34或CD34、CD33共表达,CD133急性白血病患者细胞遗传学改变无特异性.结论CD133与CD34一样为早期造血干和(或)祖细胞膜上标记.     

初治急性髓系白血病患者Bcl11a基因表达水平及其与预后的关系

目的 探讨急性髓系白血病（AML）患者Bcl11a基因表达水平及其临床意义.方法 通过实时荧光定量PCR方法检测80例初治AML患者及16例对照组Bcl11a基因的表达水平,分析其表达水平与疾病特征及临床疗效之间的关系.结果 初治AML患者Bcl11a表达水平高于对照组[0.039（0～ 0.504）比0.014（0.002 ～ 0.086）,P=0.004].以80例初治AML患者Bcl11a基因表达量的中位数作为分界点,将患者分为Bcl11a高表达组和低表达组各40例.Bcl11a低表达组AML患者中位年龄低于高表达组患者（29.5岁比41.0岁）,而初治AML患者在不同分层的性别、FAB分型、外周血象、骨髓原始细胞比例、遗传学危险度分层、免疫分型CD34表达间Bcl11a基因表达水平差异均无统计学意义（均P＞0.05）.Bcl11a基因低表达组患者完全缓解率高于高表达组[90％（36/40）比53％（21/40）,P=0.000],中位生存时间延长（268.0d比101.5 d,P=0.042）.结论 Bcl11a基因表达水平和AML患者年龄、疗效和预后存在一定的关系,Bcl11a基因高表达的AML患者预后较差.     

Expression of heparanase in hepatocellular carcinoma has prognostic significance: a tissue microarray study

Heparanase plays an important role in invasion and metastasis of tumor cells. In this study, we explored the expression and clinicopathological significance of heparanase protein in hepatocellular carcinogenesis to investigate their roles in invasion and the relationship between biological behavior and prognosis of hepatocellular carcinoma (HCC) in tissue microarrays (TMAs). Heparanase expression was examined by immunohistochemistry in TMAs comprising 120 cases of HCC, 48 cases of adjacent tumor liver, 62 cases of cirrhosis, and 23 cases of normal liver tissues. Statistical analyses were determined to access the correlation between heparanase expression and the clinicopathological features of HCC. The results showed a positive level of heparanase in HCC tissues that was significantly higher than that in adjacent tumor liver, cirrhosis, and normal liver tissue. Heparanase was expressed lower in clinical TNM stages I and II than in III and IV. Moreover, the expression of heparanase in cases without metastasis within 20 months was statistically lower than in those with metastasis. Furthermore, heparanase expression in groups of alpha-fetoprotein (AFP) > or = 400 microg/L, portal vein tumor emboli, multiple tumor nodes, and tumor diameter > or = 5 cm were significantly higher than those of corresponding groups, while it was not associated with patients' age, sex, histological classification, cirrhosis, or tumor capsular infiltration. In conclusion, TMA is a powerful tool for the rapid identification of molecular alterations in HCC. The overexpression of heparanase may play an important role in hepatocarcinogenesis, progression, and metastases of HCC. It could serve as a determining factor for clinical prognosis and curative effect.     

The prognostic significance of myelonecrosis after induction therapy in acute leukemia

Myelonecrosis is a rare antemortem finding in acute leukemia and its clinical significance is uncertain. The clinical events in nine patients with acute leukemia whose bone marrow biopsies after induction therapy revealed myelonecrosis were reviewed. No patient gained a complete remission and four patients achieved a partial remission. The median duration of survival was 2 months (range, less than 1 month to 8.5 months) from the start of therapy. Myelonerosis after induction therapy in acute leukemia indicates a very poor prognosis.     

Clinical significance of aberrant DNA methylation in childhood acute lymphoblastic leukemia

Methylation profile was analyzed in ninety-five patients with childhood acute lymphoblastic leukemia (ALL). Methylation of both MGMT and p16 genes were associated with higher age (p = 0.01 and p = 0.03, respectively). Methylation of both p15 and SHP1 genes occurred more frequently in T-ALL than in precursor B-ALL (p = 0.02 and p = 0.01, respectively). In contrast, methylation of the DAPK gene was more frequent in precursor B-ALL (p = 0.01). Patients with methylation of multiple genes more likely had T cell phenotype, and are classified as medium/high risk (p = 0.004 and p = 0.03, respectively). These results suggest that methylation status is associated with clinicopathological features in childhood ALL.     

Expression and characteristics of a novel human osteosarcoma-associated cell surface antigen

The characteristics of a new osteosarcoma-associated cell surface antigen were studied by means of two murine monoclonal antibodies, TP-1 and TP-3, which were found to bind to two different epitopes on the same antigen, a monomeric polypeptide with a molecular weight of approximately 80,000. Immunohistochemical studies showed that the antigen was present in all osteogenic sarcomas tested, in most cases of malignant fibrous histiocytoma, in two malignant hemangiopericytomas and in a few synovial sarcomas, but not in other main groups of sarcomas and nonsarcomatous malignancies. In normal tissues it was detected only in clusters of cells in the adrenal medulla and in proximal kidney tubules. Also endothelial cells in proliferating capillaries in placenta and in most tumors were stained. The antigen was absent in resting but present in actively proliferating osteoblastic cells. The epitopes were resistant to proteolytic and sugar-cleaving enzymes but sensitive to high temperatures and could not be detected in paraffin-embedded specimens. The tissue distribution and properties of the antigen show that it is different from the sarcoma-associated antigens previously studied. In contrast to previous findings with three other anti-sarcoma monoclonal antibodies, no correlation was found between serum alkaline phosphatase activity and the amount of TP-binding substances in the same sera. Nevertheless, an apparently complex association between alkaline phosphatase and the TP-binding antigen seems to exist. Thus, the Mr 80,000 antigen extracted from an osteosarcoma cell line showed enzyme activity, whereas TP-binding molecules precipitated from patient sera contained alkaline phosphatase activity only in a few of the cases studied. Altogether our data suggest that the antigen defined by the TP antibodies may be a marker of osteoblastic differentiation. The pattern of antigen expression in malignant tumors is unique, inasmuch as the antigen is found selectively in sarcomas and in all 31 osteosarcomas tested.