小肠腺癌组织的细胞凋亡及相关蛋白Bid和Bcl-xL的表达及意义

目的:探讨细胞凋亡及相关蛋白的表达与小肠腺癌发生发展的关系.方法:研究包括35例正常小肠(空肠)组织和7例手术切除的小肠腺癌组织,临床资料查阅病历;用TUNEL法检测细胞凋亡;用免疫组织化学检测相关蛋Bid和Bcl-xL的表达.结果:小肠腺癌的凋亡指数(apoptotic index,AI)明显低于正常小肠组织(0.29% vs 15.78%,t=6.51,P<0.01):蛋白Bid在小肠腺癌的表达低于正常小肠组织(28.57% vs 77.14%,P<0.05);蛋白Bcl-xL在小肠腺癌的表达高于正常组织(86.7 1% vs 34.29%,P<0.05):Bid/Bcl-xL≥1的样本数在小肠腺癌低于正常小肠(14.29% vs 80.00%,P<0.01).相关性分析显示AI和蛋白Bid的免疫组织化学得分呈正相关(r=0.368,P<0.05),但与蛋白Bcl-xL的免疫组织化学得分之间缺乏相关性(r=0.017,P>0.05).结论:细胞凋亡水平的降低;蛋白Bid的低表达和Bid/Bcl-xL比值的降低可能在小肠肿瘤的发生和发展过程中发挥重要的作用.     

Significance of Bcl-xL in human colon carcinoma

AIM：To investigate the clinical significance of Bcl-xL gene in the pathogenesis of human colon carcinoma. METHODS：Fifty-six pair tissue samples from patients with colon cancer were collected, and protein level of the Bcl-xL gene was measured by immunohistochemistry method. The correlation of Bcl-xL expression with clinical index was evaluated. After human colon cancer cell line HT29 was transfected with Bcl-xL small interfering RNA （siRNA）, the anchorage-independent growth of cancer cells was detected by colony formation in soft agar and invasion ability of cancer cells was determined by a transwell model.
RESULTS：The Bcl-xL expression was higher in cancerous tissue samples than in normal tissue samples （38.78 ± 11.36 vs 0.89 ± 0.35, P 〈 0.001）, and was associated with the pathological grade, lymphnode metastasis and Duke＇s stage of colorectal carcinoma. Transfection with Bcl-xL siRNA inhibited the colony formation and invasion ability of human colon cancer cell line HT29 in vitro.
CONCLUSION：Bcl-xL gene plays an important role in carcinogenesis of human colorectal carcinoma and is associated with malignant biological behaviors of human colorectal carcinoma.     

细胞凋亡在结肠腺癌组织中的变化及其相关蛋白的表达

目的:观察结肠腺癌组织细胞凋亡的变化,探讨抑制凋亡蛋白Bcl-2、Bcl-xL及Bcl-w在结肠腺癌中的作用.方法:收集14例我院手术切除结肠腺癌标本,肠镜取正常结肠黏膜组织27例,所有标本均经病理明确诊断.用TUNEL法检测其组织细胞凋亡水平,并用免疫组织化学PV法检测蛋白Bcl-2、Bcl-xL及Bcl-w的表达水平.结果:正常结肠黏膜组织的细胞凋亡指数明显高于结肠腺癌,有统计学显著性差异(t=3.35,P=0.002);结肠腺癌中Bcl-xL与Bcl-w的表达均高于正常结肠黏膜组织,有统计学差异(92.86% vs 11.11%;85.71% vs 0%,P<0.01或P<0.05);Bcl-2的表达与正常结肠黏膜组织没有统计学差异(P>0.05).结论:结肠腺癌的组织细胞凋亡明显低于正常结肠组织:结肠腺癌中抑制凋亡蛋白Bcl-xL与Bcl-w的高表达可能发挥了重要的作用.     

嘧啶亚硝脲对胶质母细胞瘤A-172细胞中Bcl-xL mRNA和蛋白表达的影响

目的 探讨嘧啶亚硝脲(ACNU)对人胶质母细胞瘤A-172细胞Bcl-xL mRNA及其蛋白表达和A-172细胞增殖活性的影响.方法用免疫组化SP法、RT-PCR和MTT法分别检测不同浓度ACNU作用于A-172细胞后Bcl-xL mRNA、蛋白的表达.结果不同浓度ACNU作用A-172细胞后Bcl-xL mRNA相对水平均高于未加ACNU作用的A-172细胞(P<0.01),随着ACNU浓度的增加,Bcl-xL蛋白表达逐渐下降,对细胞增殖活性的抑制率逐渐增高;ACNU为25μg/ml时,细胞增殖抑制率增幅最大为54.48%.结论 A-172细胞中Bcl-xL mRNA、蛋白呈高表达.ACNU可以诱导降低胶质母细胞瘤A-172细胞中Bcl-xL的表达,促进其细胞凋亡.对A-172细胞增殖活性具有明显抑制作用.     

T-2毒素对软骨细胞P53、Bcl—xL和Caspase-3表达的影响

目的 观察T-2毒素对软骨细胞P53、Bcl-xL和caspase-3表达的影响.方法 采用胎儿软骨细胞体外培养,培养基中加入不同浓度的T-2毒素(1～20μ/L)连续培养5 d.采用Western blot检测软骨细胞P53、Bcl-xL和Caspase-3蛋白表达水平;用RT-PCR法检测软骨细胞P53、Bcl-xL和Caspase-3 mRNA的表达.结果 与对照组比较,不同浓度(1～20μL)的T-2毒素均能引起Caspase-3蛋白表达水平升高而Bcl-xL蛋白表达水平下降(P＜0.05);当T-2毒素浓度达到10～20μg/L时,P53蛋白和Caspase-3 mRNA表达水平明显升高(P＜0.05)而Bcl-xLmRNA的表达水平无显著性下调(P＞0.05);T-2毒素浓度达到20μ/L可以引起P53 mRNA表达水平明显升高(P＜0.05).结论 T-2毒素诱导软骨细胞发生的凋亡可能与T-2毒素上调软骨细胞P53、caspase-3表达,同时下调Bcl-xL表达有关.     

Connexin 26 correlates with Bcl-xL and Bax proteins expression in colorectal cancer

AIM: To evaluate of Cx26 in correlation with Bcl-xL and Bax proteins in colorectal cancer. METHODS: Immunohistochemical staining using specific antibodies was performed to evaluate the protein expression of Cx26, Bax and Bcl-xL in 152 colorectal cancer samples and the correlations among studied proteins as well as the relationships between the expression of Cx26, Bax, Bcl-xL and clinicopathological features were analyzed. RESULTS: Both normal epithelial cells and carcinoma cells expressed Cx26, Bax and Bcl-xL, but Cx26 in cancer cells showed aberrant, mainly cytoplasmic staining. Expression of Cx26, Bax and Bcl-xL was observed in 55.9%, 55.5% and 72.4% of evaluated colorectal cancers respectively. We found the positive correlation between Cx26 and Bax expression (r= 0.561, P<0.0001), Cx26 and Bcl-xL (P=0.409, P<0.0001) as well as between Bax and Bcl-xL (P=0.486, P<0.0001). Association of Cx26, Bax and Bcl-xL expression with histological G2 grade of tumors was noted (P<0.005, P<0.001 and P<0.002 respectively). CONCLUSION: Cytoplasmic presence of Cx26 and its association with apoptotic markers could indicate a distinct role from physiological functions of Cx26 in cancer cells and it could suggest that connexins might be a target point for modulations of apoptosis with therapeutic implications.     

Mcl-1 and Bcl-xL are co-regulated by IL-6 in human myeloma cells

Multiple myeloma (MM) is a slowly proliferative malignancy in which malignant plasma cells accumulate within the bone marrow. The expression of several anti-apoptotic proteins was evaluated by immunoblotting in human myeloma cell lines and in highly purified native myeloma cells. Expression of Bcl-xL, Mcl-1 and Bcl-2 was found in most of the samples; expression of Bcl-xL and Mcl-1 seemed to be related on myeloma cells. In a system of apoptosis by growth factor deprivation on myeloma cells, we showed that the effect of Bcl-2 seemed minimal whereas Mcl-1 and Bcl-xL were tightly regulated by interleukin (IL)-6. These findings underline the important role of Mcl-1 and Bcl-xL instead of Bcl-2 in IL-6-induced survival of myeloma cells.     

长链非编码RNA-lncRNA2在食管癌中高表达

目的探讨lncRNA2在食管癌中的表达情况,及lncRNA2异常表达作为食管癌的潜在诊断标志物和治疗靶标的可能。方法应用lncRNA表达芯片技术对14对配对的食管癌和癌旁组织进行分析,获得在癌组织和癌旁组织中差异表达>10倍的lncRNA 134个。应用RT-PCR技术在食管癌细胞系进行验证,并分析43对配对的癌及癌旁组织中的表达情况。结果在14个食管癌细胞系中,lncRNA2在10个食管癌细胞系中高表达,而在4个食管癌细胞系中缺失表达。在43对配对的食管癌及癌旁组织中,lncRNA2在26例癌组织中高表达,在癌旁组织中缺失表达或低表达;11例在癌组织中缺失表达或低表达,而在癌旁组织中高表达;另外6例在癌组织和癌旁组织中均缺失表达。lncRNA2在60.47%(26/43)的食管癌组织中高表达,而在25.58%(11/43)的癌旁组织中高表达,差异有统计学意义(P<0.01)。lncRNA2高表达与患者年龄、性别、TNM分期、肿瘤大小、吸烟史、饮酒史、家族史等临床因素无相关性(P均>0.05)。结论lncRNA2在食管癌中表达明显升高,是食管癌潜在的诊断标志物和治疗靶标。     

Bone marrow histopathology in peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCL) account for 10-15% of all lymphoproliferative disorders in the western hemisphere. In PTCL, bone marrow biopsy is performed to establish the diagnosis, rule out other pathology, assess the extent of disease and monitor treatment response. The frequency and histology of bone marrow involvement varies greatly between different clinicopathological entities recognized by the World Health Organisation (WHO) classification, reflecting the differences in the underlying biology. Some lymphomas, such as angioimmunoblastic T-cell lymphoma, show nodular and/or interstitial pattern of infiltration with accompanying reactive changes. Others, including hepatosplenic T-cell lymphoma and large granular lymphocyte leukaemia, are characterized by intrasinusoidal infiltration. In many instances the pathological features are subtle and immunohistochemical and molecular studies are required for the diagnosis. Histological appearances may overlap with a variety of reactive T-cell proliferations and other malignancies. Furthermore PTCL frequently induce secondary changes in the marrow that may obscure the neoplastic infiltrate. The diagnosis often requires critical integration of the information obtained from clinical features, peripheral blood, bone marrow aspirate and biopsy findings. In this article we review the histopathology of bone marrow biopsy in PTCL within the context of the new WHO classification.     

Syndecan-1 (CD138) expression in human non-Hodgkin lymphomas

Syndecan-1, an important transmembrane heparan sulphate proteoglycan is expressed in distinct stages of differentiation of normal lymphoid cells: in pre-B cells and Ig-producing plasma cells; however, its normal function, or presence in lymphoid malignancies, is still largely unknown. The expression of syndecan-1 (CD138) was studied in 57 human non-Hodgkin lymphomas using immunocytochemistry and immunohistochemistry. Positive expression of syndecan-1 was found in the plasma cells in chronic lymphoblastic leukaemia (B-CLL) cases, in different plasmocytoid lymphomas as well as in myeloma. All normal and malignant Tcells, or CD5+ cells other than B-CLL proved to be negative. These results strongly suggest that syndecan-1 expression is a characteristic phenotypic marker for B-CLL and lymphoplasmocytoid lymphomas and could be used for diagnostic purposes.     

Immunophenotypic identification of possible therapeutic targets in paediatric non-Hodgkin lymphomas: a children's oncology group report

Immunophenotypic analysis can identify protein epitopes in non-Hodgkin lymphomas (NHL) that may respond to targeted immunotherapies, such as anti-CD20 and anti-CD52. Recent studies suggest additional targets may provide therapeutic benefits in NHL. This study evaluated protein expression of CD25, CD52, CD74 and CD80 in paediatric NHL to determine possible targets for immune-based therapeutic approaches. Patient samples were derived from paediatric NHL clinical trials sponsored by the Children's Cancer Group (CCG, now the Children's Oncology Group, COG) and included Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), disseminated T- and B-cell lymphoblastic lymphoma (T-LBL and B-LBL) and anaplastic large cell (ALCL). Immunophenotypic studies were performed on formalin-fixed, paraffin-embedded diagnostic tissues. CD25 was expressed in 8% of T-LBL and 75% of ALCL cases, but not in BL, DLBCL, or B-LBL. CD52 was expressed in 99% of cases of paediatric NHL of all subtypes. CD74 was expressed in 100% of B-LBL, BL and DLBCL, but was absent in ALCL and T-LBL. CD80 was expressed in 12% of B-LBL, 6% of BL and 10% of DLBCL cases studied, but was not detected in T-cell NHL. These expression patterns suggest that CD25, CD52 and CD74 may represent potential new therapeutic targets in paediatric NHL.     

High frequency of t(11;18) in gastric mucosa-associated lymphoid tissue lymphomas in Taiwan,including one patient with high-grade transformation

t(11;18)(q21;q21), the most frequent chromosomal aberration of mucosa-associated lymphoid tissue (MALT) lymphoma, occurs in 30% of gastric patients.Although the translocation is often associated with an 'aggressive' course, it has not been described in transformed MALT lymphomas. We screened 15 gastric MALT lymphomas [three with concurrent or subsequent high-grade transformation and 11 diffuse large B-cell lymphomas (DLBCLs)] in Chinese patients for t(11;18). t(11;18) was found in 9/15 (60%) MALT lymphomas, but not in any DLBCLs. One patient, with subsequent high-grade transformation, showed the translocation in low- and high-grade lesions. t(11;18) was frequent in Chinese gastric MALT lymphomas and unusually one transformed lymphoma carried the translocation.     

Bcl-x(L) and Myeloid cell leukaemia-1 contribute to apoptosis resistance of colorectal cancer cells

AIM： TO explore the role of Bcl-XL and Myeloid cell leukaemia （Mcl）-I for the apoptosis resistance of colorectal carcinoma （CRC） cells towards current treatment modalities. METHODS： Bcl-XL and Mcl-1 mRNA and protein expression were analyzed in CRC cell lines as well as human CRC tissue by Western blot, quantitative PCRand immunohistochemistry. Bcl-XL and Mcl-1 protein expression was knocked down or increased in CRC cell lines by applying specific siRNAs or expression plasmids, respectively. After modulation of protein expression, CRC cells were treated with chemotherapeutic agents, an antagonistic epidermal growth factor receptor （EGFR1） antibody, an EGFR1 tyrosine kinase inhibitor, or with the death receptor ligand TRAIL. Apoptosis induction and cell viability were analyzed. RESULTS： Here we show that in human CRC tissue and various CRC cell lines both Bcl-xL and Mcl-1 are expressed. Bcl-xL expression was higher in CRC tissue than in surrounding non-malignant tissue, both on protein and mRNA level. Mcl-1 mRNA expression was significantly lower in malignant tissues. However, protein expression was slightly higher. Viability rates of CRC cells were significantly decreased after knock down of Bcl-xL expression, and, to a lower extent, after knock down of Mcl-1 expression. Furthermore, cells with reduced Bcl-xL or Mcl-1 expression was more sensitive towards oxaliplatinand irinotecan-induced apoptosis, and in the case of Bcl-xL also towards 5-FU-induced apoptosis. On the other hand, upregulation of Bcl-xL by transfection of an expression plasmid decreased chemotherapeutic drug-induced apoptosis. EGF treatment clearly induced Bcl-xL and Mcl-1 expression in CRC cells. Apoptosis induction upon EGFR1 blockage by cetuximab or PD168393 was increased by inhibiting Mcl-1 and Bcl-xL expression. More strikingly, CD95- and TRAIL-induced apoptosis was increased by Bcl-xL knock down. CONCLUSION： Our data suggest that Bcl-xL and, to a lower extent, Mcl-1, are important anti-apoptotic factors in CRC. Specific do     

BCL2 protein expression in follicular lymphomas with t(14;18) chromosomal translocations

The t(14;18)(q32;q21) chromosomal translocation induces BCL2 protein overexpression in most follicular lymphomas. However the expression of BCL2 is not always homogeneous and may demonstrate a variable degree of heterogeneity. This study analysed BCL2 protein expression pattern in 33 cases of t(14;18)-positive follicular lymphomas using antibodies against two different epitopes (i.e. the widely used antibody BCL2/124 and an alternative antibody E17). 16/33 (49%) cases demonstrated strong BCL2 expression. In 10/33 (30%) cases, BCL2 expression was heterogeneous and in some of these, its loss appeared to be correlated with cell proliferation, as indicated by Ki67 expression. Double immunofluorescence labelling confirmed an inverse BCL2/Ki67 relationship, where in 24/28 (86%) cases cellular expression of BCL2 and Ki67 was mutually exclusive. In addition, seven BCL2 'pseudo-negative' cases were identified in which immunostaining was negative with antibody BCL2/124, but positive with antibody E17. Genomic DNA sequencing of these 'pseudo-negative' cases demonstrated eleven mutations in four cases and nine of these were missense mutations. It can be concluded that in follicular lymphomas, despite carrying the t(14;18) translocations, BCL2 protein expression may be heterogeneous and loss of BCL2 could be related to cell proliferation. Secondly, mutations in translocated BCL2 genes appear to be common and may cause BCL2 pseudo-negative immunostaining.