Unexpectedly late expression of intracellular CD3epsilon and TCR gammadelta proteins during adult thymus development.

During adult thymus development immature CD4(-)CD8(-) [double-negative (DN)] precursor cells pass through four phenotypically distinct stages defined by expression of CD44 and CD25: CD44(hi)CD25(-) (DN1), CD44(hi)CD25(+) (DN2), CD44(lo)CD25(+) (DN3) and CD44(lo)CD25(-) (DN4). Although it is well established that the TCR beta, gamma and delta genes are rearranged and expressed in association with the CD3 components in DN thymocytes, the precise timing of expression of the TCR and CD3 proteins has not been determined. In this report we have utilized a sensitive intracellular (ic) staining technique to analyze the expression of ic CD3epsilon, TCR beta and TCR gammadelta proteins in immature DN subsets. As expected from previous studies of TCR beta rearrangement and mRNA expression, icTCR beta(+) cells were first detected in the DN3 subset and their proportion increased thereafter. Surprisingly, however, both icCD3epsilon(+) and icTCR gammadelta(+) cells were detected at later stages of development than was predicted by molecular studies. In particular icCD3epsilon protein expression coincided with the transition from the DN2 to DN3 stage of development, whereas icTCR gammadelta protein expression was only detected in a minor subset of DN4 cells. The implications of these findings for alphabeta lineage divergence will be discussed.     

Preferential usage of JH2 in D-J joinings with DQ52 in murine lymphocytes

Southern blot analysis of genomic DNA of normal mouse thymocytes with a JH4 probe, a probe for JH4 of Igh genes, consistently showed a second band in addition to a germline band. The same band was also observed in analysis with a 5' DQ probe, a 5'-flanking sequence of DQ52, thus suggesting the use of DQ52. By analyzing EcoRI- and PvuII-digested genomic DNA, the above-observed band was demonstrated to be the result of DQ52-JH2 joining. This was further confirmed utilizing a T cell leukemia line with known DQ52-JH joinings. We then quantitatively estimated the frequencies of JH segment usages in joining with DQ52, through plaque hybridization assays. Three hundred and fifty JH4-positive clones were obtained from 7 x 10(5) plaques by plaque hybridization. Forty-eight randomly selected non-germline clones were purified and the use of JH segments was determined through Southern blot analysis. Nine clones used JH1, 29 used JH2, 9 used JH3, and 1 used JH4, thus indicating an apparent preferential usage of JH2 segment. Southern blot analysis of genomic DNA of progenitor B cells in culture showed a dominant band of DQ52-JH2 joining 1 week after initiation of culture. This may indicate that the dominant DQ52-JH2 joining in thymocytes is representative of early D-J joinings in progenitor B cells.     

Clinicopathological study of gene rearrangement and microRNA expression of primary central nervous system diffuse large B-cell lymphomas

We studied the clinicopathological and imaging characteristics of primary central nervous system diffuse large B-cell lymphomas (PCNS-DLBCL). Imaging, pathologic histology, and immunohistochemical staining characteristics were analyzed, and the immunoglobulin heavy and light chain gene rearrangement of 25 PCNS-DLBCL cases was examined. MicroRNA was extracted from 10 cases each of PCNS-DLBCL, extracerebral germinal center DLBCL (GC-DLBCL), and extracerebral non-GC-DLBCL (NGC-DLBCL); we conducted chip hybridization and comparatively analyzed the difference among the three. PCNS-DLBCLs typically involved no less than two cerebral lobes (10/25); the frontal lobe was affected most often (6/25). Target-shaped structures were observed in all PCNS-DLBCLs due to the proliferation of centroblast-like large lymphocytes surrounding the vessels. There was strong and diffuse immunostaining for CD20 and CD79a, and negative immunostaining for CD3, CD5, CD23, and cyclin D1 for all PCNS-DLBCLs. The percentage of cells with nuclear positivity for anti-Ki67 antibody ranged 50-90% (mean, 80%). Three, 19, and 22 PCNS-DLBCLs were CD10-, Bcl-6-, and melanoma ubiquitous mutated 1-positive, respectively. Twenty-four PCNS-DLBCLs were B-cell monoclonal. MicroRNA hybridization showed that 788 PCNS-DLBCL microRNAs/segments increased to at least twice that of NGC-DLBCLs, and 401 PCNS-DLBCL microRNAs/segments declined to less than half of that of NGC-DLBCLs. Six hundred and eleven PCNS-DLBCL microRNAs/segments increased to at least twice that of GC-DLBCLs, and 229 PCNS-DLBCL microRNAs/segments declined to less than half of that in GC-DLBCLs. PCNS-DLBCL typically affected multiple sites, tended to occur in older men, arose from activated B cells, had high B-cell monoclonality; its microRNA expression differed from that of NGC-DLBCL and GC-DLBCL.     

Monocytoid/marginal zone B-cell differentiation in follicle centre cell lymphoma

We report on two cases of low grade follicle centre cell lymphoma with a pronounced parafollicular monocytoid/marginal zone B-cell component. One patient had a history of preceeding follicular high grade B-cell lymphoma of centroblastic type showing the same light chain restriction and identical immunoglobulin heavy chain gene rearrangement as the low grade lymphoma diagnosed 15 months later. Morphologically, in both cases the two constituents of the low grade tumours were clearly distinguishable. Immunohistochemically, the follicular component strongly expressed bcl-2 protein in contrast to a weak staining of the marginal zone B-cell component. Performing PCR, a rearrangement of the major breakpoint region of bcl-2 was not found. Identical light chain restriction of the follicular and the monocytoid B-cell/marginal zone components strongly indicates a clonal relationship between them. A monocytoid/marginal zone B-cell component in follicular lymphoma probably results from differentiation of the follicle centre cells and does not indicate a composite lymphoma.     

A B220(-), CD19(-) population of B cells in the peripheral blood of quasimonoclonal mice

We describe a new population of non-naive B cells in the peripheral blood of quasimonoclonal (QM) mice. Surface Ig of switched isotypes is expressed, but not B220 nor CD19. These cells are larger and denser than naive B cells but smaller than blasts or plasma cells; they do not stain with syndecan, a marker for plasma cells. Telomerase, which is usually expressed in B cell blasts, was not present in this population. We sorted the switched, idiotype-positive, B220(-) B cells from the peripheral blood of QM mice and sequenced Ig H chain and lambda L chain cDNA. There were many point mutations but no V gene replacements, gene conversions or other type of diversifications. As they express switched isotypes and have mutated their Ig genes, cells in the B220(-), CD19(-) population must have been in an immune response and we suggest that it includes the memory B cell subset.     

椎间盘退变过程中MMP/Timp基因表达变化的研究

目的:采用新西兰大白兔的纤维环损伤制作腰椎间盘退变模型,以证实和比较在人椎间盘退变中的基因变化情况.方法:损伤L4.5、L5.6纤维环,行核磁共振及计算机扫描摄影拍片证实椎间盘退变情况,同时取椎间盘行精确定量逆转录聚合酶链式反应观测MMP/Timp系列基因的变化.结果:证实了兔腰椎纤维环损伤后腰椎逐渐退变,且与人类退变结果相似,基因表达情况MMP-1、MMP-2、MMP-3、Timp-1、Timp-2早期均上调,MMP-3、Timp-1在退变的晚期出现下调.结论:人类腰椎间盘退变中明显上调的基因在此退变模型椎间盘中被发现同样上调,从而在分子水平证实了此动物退变模型与人类的相似性.     

Modulation of T cell development and activation by novel members of the Schlafen (slfn) gene family harbouring an RNA helicase-like motif

The regulatory networks governing development and differentiation of hematopoietic cells are incompletely understood. Members of the Schlafen (Slfn) protein family have been implicated in the regulation of cell growth and T cell development. We have identified and chromosomally mapped four new members, slfn5, slfn8, slfn9 and slfn10, which belong to a distinct subgroup within this gene family. The characteristic feature of these proteins is the presence of sequence motifs identifying them as distinct members of the superfamily I of DNA/RNA helicases. A significant role of these newly identified members in hematopoietic cell differentiation is suggested based on their differential regulation (i) in developing and activated T cells, (ii) in LPS or IFNgamma activated macrophages, (iii) upon IL6 or LIF driven terminal differentiation of myeloblastic M1 cells into macrophage-like cells, and (iv) in splenocytes of mice infected with Listeria monocytogenes. In contrast to wild-type cells, IRF-1 and IFNalpha/betaR deficient macrophages, although undergoing growth arrest, fail to upregulate slfn gene expression upon IFNgamma or LPS stimulation, respectively. Therefore, an essential participation in IFNgamma or LPS induced growth arrest appears unlikely. Likewise, ectopic expression of the newly identified slfn family members in fibroblasts did not reveal a general impact on growth control. In contrast, transgenic T-cell specific expression of a representative member of this new subfamily, slfn8, resulted in profoundly impaired T cell development and peripheral T cells showed a reduced proliferative potential. Thus, functional participation of slfn8 in the regulatory networks governing T cell development and growth appears to be cell type specific.     

Sequential development of diffuse large B-cell lymphoma in a patient with angioimmunoblastic T-cell lymphoma

Lymphoma of different histologic type can occur in the same patient. Here, we describe a 64-year-old male patient with angioimmunoblastic T-cell lymphoma (AITL) who subsequently developed diffuse large B-cell lymphoma (DLBCL). At the time of initial diagnosis, histologic examination of a left inguinal lymph node of the patient and a monoclonal pattern of TCRβ gene rearrangement showed typical features of AITL, and there was no evidence of a monoclonal B-cell population. Twenty-six months later, he had generalized lymphadenopathy and organs involvement by DLBCL. A monoclonal IgH gene rearrangement proved de novo development of secondary B-cell lymphoma and excluded relapse of a primary composite lymphoma. The in situ hybridization analysis showed Epstein-Barr-encoded RNA (EBER) sporadic positivity in sample collected from AITL but extensive positivity in the immunoblasts collected from DLBCL. Our observation supports the hypothesis that Epstein-Barr virus (EBV) is etiologically related to AITL in this case. Clonal expansion of EBV-associated DLBCL is a secondary event in AITL via EBV infection or reactivation.     

Common and HIV-related diffuse large B-cell lymphomas differ in their immunoglobulin gene mutation pattern

HIV-infected patients are at high risk of developing diffuse large B-cell lymphomas (DLBCL). It is currently unclear whether these lymphomas represent Epstein-Barr virus (EBV)-driven lymphoproliferations that develop in the setting of immunodeficiency, or whether these tumours are more closely related to the DLBCL seen in the general population. To clarify this issue, 12 HIV-related DLBCL from 11 patients were analysed for the presence of clonally rearranged and somatically mutated immunoglobulin heavy chain (IgH) genes and their association with EBV was determined. Eleven of the 12 tumour samples displayed monoclonal rearrangements of the IgH genes, with or without a moderate number of somatic mutations in the CDRII and in the FWIII regions (average four mutations). One patient presented two successive lesions; whereas the initial tumour showed an oligoclonal IgH rearrangement, the lymphoma at relapse proved to harbour a monoclonal B-cell population. Ten of 12 tumour samples expressed the EBV encoded small RNAs (EBERs), and six of these EBV-positive cases displayed, in addition, an expression of the EBV encoded nuclear antigen 2 (EBNA-2). The results obtained from HIV-related DLBCL are at variance to those described for DLBCL occurring in the general population, since the latter contain significantly more somatic IgH mutations in the CDRII and in the FWIII regions and are only rarely associated with EBV. It is concluded from these findings that HIV-related DLBCL represent a distinct group of B-cell lymphomas, a significant fraction of which most likely originates from EBV-driven lymphoproliferations, and that half of the cases derive from pre-germinal centre B-cells. Copyright © 1999 John Wiley & Sons, Ltd.     

Variable expression of Epstein-Barr virus-induced gene 3 during normal B-cell differentiation and among B-cell lymphomas

Epstein-Barr virus (EBV)-induced gene 3 (EBI3) is expressed by tumour cells in several EBV-associated malignancies. EBI3 was recently found to associate with a novel peptide, p28, to form a new heterodimeric cytokine, called interleukin-27. In this study, we investigated EBI3 and p28 expression in normal human B lymphocytes and in non-EBV-associated B-cell lymphomas. Low levels of EBI3 were detected in purified tonsillar B cells and expression was upregulated upon anti-CD40 or anti-micro stimulation via NF-kappaB activation. In non-neoplastic tissues, EBI3 expression by lymphocytes was largely restricted to a subset of germinal centre (GC) B cells located at the margin of the light zone, in close contact with CD3+ T lymphocytes. Over 50% of EBI3+ GC B cells were engaged in cell proliferation as assessed by Ki67 expression, and 10-30% expressed MUM1, an early marker of plasma cell differentiation expressed by late centrocytes. Many EBI3+ GC B cells had downregulated bcl-6 expression, which further suggests that these cells correspond to late CD40-activated centrocytes. Immunohistochemical analysis of 64 B-cell lymphomas showed that the highest EBI3 levels were detected in follicular lymphomas and in diffuse large B-cell lymphomas of both GC B-cell-like or non-GC B-cell-like types. No or rare p28 expression was detected in normal or tumour B cells. This constitutive expression of EBI3 by neoplastic B cells may be involved in lymphomagenesis, and may be a useful marker for lymphoma diagnosis.     

弥漫大B细胞淋巴瘤组织bcl-6蛋白表达及基因重排

目的探讨弥漫大B细胞淋巴瘤(DLBCL)中bcl-6和CD10蛋白表达以及基因重排的特点及其临床病理意义。方法应用免疫组织化学EnVision法分析51例DLBCL(22例为淋巴结内,29例为淋巴结外)和10例淋巴结反应性增生石蜡组织中bcl-6蛋白表达,并与CD10的表达作比较分析;应用断裂分离探针及间期核荧光原位杂交(FISH)技术检测32例淋巴结内DLBCL(22例为石蜡组织,10例为新鲜组织)和5例淋巴结反应性增生石蜡组织中bcl-6基因的重排。结果(1)淋巴结内、外DLBCL和淋巴结反应性增生中bcl-6蛋白均呈细胞核表达,阳性率分别为72.7%(16/22)、75.9%(22/29)、100.0%(10/10);CD10的阳性率分别为40.9%(9/22)、41.4%(12/29)、100.0%(10/10),所有CD10阳性肿瘤均共同表达bcl-6蛋白。(2)40.9%(9/22)的淋巴结内DLBCL和41.4%(12/29)的淋巴结外DLBCL为两蛋白共同阳性表达;将之与两蛋白均不表达的DLBCL(27.3%,6/22和24.1%,7/29)相比,前者(Ⅰ或Ⅱ期)的临床分期低于后者(Ⅲ或Ⅳ期,P<0.05)。(3)淋巴结内DLBCL样本中bcl6基因重排阳性率为28.1%(9/32),其中石蜡组织样本阳性率为27.3%(6/22),新鲜组织样本阳性率为30.0%(3/10),P>0.05。5例淋巴结反应性增生样本中均未检测到bcl-6基因重排,与DLBCL相比P<0.05。结论(1)在DLBCL中bcl6有较高的阳性表达率,bcl-6和CD10蛋白的联合检测可以协助DLBCL的诊断和鉴别诊断;bcl6和CD10共同阳性的DLBCL可能具有更好的预后。(2)bcl-6基因重排可能参与了部分DLBCL的发生,并可作为DLBCL诊断的参考指标。     

人Gax基因真核表达载体的构建及在血管平滑肌细胞中的表达

目的:构建人Gax基因真核表达载体,并观察在兔血管平滑肌细胞中的表达。方法:通过PCR从pCMV-SPORT6-Gax质粒中扩增出人Gax cDNA片段,经双酶切后装入到有绿色荧光蛋白报告基因的真核表达载体pEGFP-N1中,经限制性内切酶酶切分析和DNA测序鉴定后通过梭华-Sofast转染试剂介导重组质粒转染至兔血管平滑肌细胞中进行表达,通过荧光显微镜观察转染细胞的绿色荧光蛋白表达和RT-PCR扩增转染细胞的cDNA来鉴定Gax在兔血管平滑肌细胞中的表达。结果:琼脂糖凝胶电泳检测PCR扩增产物人Gax基因片段约915bp,与预期分子量相符;酶切分析和测序鉴定证明人Gax真核表达载体pEGFP-N1-Gax连接正确;荧光显微镜观察到重组质粒转染细胞中有绿色荧光蛋白表达,及RT-PCR证明转染细胞有人GaxmRNA表达。结论:成功构建人Gax基因的重组真核表达载体pEGFP-N1-Gax,并证实在兔血管平滑肌细胞中表达,为进一步研究Gax基因在心血管病中的作用提供了实验基础。     

弥漫性大B细胞淋巴瘤各分子亚型中的bcl-6基因重排与蛋白表达的临床意义

目的 探讨弥漫性大B细胞淋巴瘤(DLBCL)各分子亚型中的bel-6基因重排、蛋白表达情况及其临床病理意义.方法 运用组织芯片技术,通过荧光原位杂交(FISH)技术对149例DLBCL组织中bcl-6基因重排进行检测,应用免疫组织化学技术(EnVision法)检测bcl-6以及细胞增殖指标Ki-67、细胞周期蛋白(cyclin)D3、p27Kill及Geminin等蛋白表达水平;结合临床病理资料,分析它们之间的相关性.结果 149例DLBCL可被分成3个分子亚型,其中4J0例为生发中心B细胞样(GCB样)亚型,75例为活化的非生发中心B细胞样(ABC样)亚型,34例为Type 3亚型.有118例成功进行了FISH检测,33例可检测到bcl-6基因重排,阳性率为28.0%.其中35.5%(22/62)的ABC样亚型DLBCL呈现bcl-6基因重排;较GCB样亚型(6/31,19.4%)和Type 3亚型(5/25,20.0%)的bcl-6基因重排高(P=0.160).在绝大部分(26/33,78.8%)有bcl-6基因重排的DLBCL中,伴随有bcl-6蛋白的过度表达,明显高于无bcl-6基因重排的病例(53/84,62.4%,P=0.088).有bcl-6基因重排的DLBCL中,24例(24/33,72.7%)cyclin D3呈现高水平表达,明显高于bcl-6基因无易位DLBCL组中的cyclin D3表达(37/81,45.7%,P=0.009).在33例bcl-6基因易位的DLBCL中,29例(87.9%)为Ann Arbor Ⅲ-Ⅳ期,较bcl-6基因无易位高者(65/85,76.5%,P=0.167).单变量Cox风险比模型分析发现,bcl-6基因重排与患者的生存率呈负相关,是一个危险因子,相对危险度(RR)为1.842.结论 bcl-6基因重排导致的bcl-6蛋白表达上调参与了部分DLBCL的发病过程,并可能成为DLBCL的ABC样亚型的一个分子标志.     

IgH基因单克隆重排检测及其在B细胞性非霍奇金淋巴瘤诊断中的应用

 目的：建立准确可靠、操作性强、适用于临床实际工作的免疫球蛋白重链（immunoglobulin heavy chain,IgH）基因单克隆重排检测方法,用于B细胞性非霍奇金淋巴瘤（B-cell non-Hodgkin lymphoma,B-NHL）的辅助诊断。方法：采用骨架区(framework region,FR）引物FR2、FR3和重链连接区 （joining region of heavy chain,J_H）引物LJH、VLJH组合、A管+B管模式、半巢式聚合酶链式反应(polymerase chain reaction,PCR)法对121例B-NHL、58例T细胞性非霍奇金淋巴瘤（T-cell non-Hodgkin lymphoma,T-NHL）和19例淋巴结反应性增生的石蜡组织进行IgH基因单克隆重排检测,分析IgH基因单克隆重排检出率在B-NHL组、T-NHL组和淋巴结反应性增生组中的差异,以及B-NHL中联合应用FR2和FR3与单独应用FR2、FR3之间IgH基因单克隆重排检出率的差异。结果：118例成功检测的B-NHL中,IgH基因单克隆重排检出率为81%（96/118）;54例成功检测的T-NHL中,IgH基因单克隆重排检出率为4%（2/54）;19例成功检测的淋巴结反应性增生中未检出IgH基因单克隆重排。B-NHL组与T-NHL组、淋巴结反应性增生组相比,IgH基因单克隆重排检出率差异具有显著性（P<0.05）。B-NHL中, FR2基因单克隆重排检出率为58%（68/118）,FR3基因单克隆重排检出率为55%（65/118）,联合应用FR2和FR3,IgH基因单克隆重排检出率为81%（96/118）,联合应用FR2和FR3与单独应用FR2、FR3的检出率有显著差异（P<0.05）。结论：采用FR2、FR3、LJH及VLJH引物组合、A管+B管模式和半巢式PCR法进行石蜡组织IgH基因单克隆重排检测,简单易行,结果准确可靠,阳性率较高,可用于临床B-NHL的辅助诊断。     

分化早期小儿急性白血病细胞免疫球蛋白和T细胞受体基因结构的变化

从29例免疫分型的小儿急性白血病中选出髓过氧化物酶染色阴性和不与细胞系相关或成熟细胞系相关的单克隆抗体反应的6例白血病细胞,进一步作免疫球蛋白(包括重链和κ轻链)和T细胞受体(包括δ、γ、β)基因结构的分析。所有6例均有IgH基因的重排,提示这些白血病细胞是β细胞来源。两例CD_(10)阴性和白病细胞.κ链基因没有重排,其中一例的TCRδ、γ、β基因也都处于胚系,另一例的TCRβ处于胚系。在CD_(10)阳性白血病细胞中,其中两例κ链基因丢失,TCR基因结构都有不同程度的变化(重排或丢失)。这些结果可能提示在CD_(10)阳性白血病细胞中能产生功能性IgH的重排,并可导致IgL和TCR基因结构的变化。     

黄体生成素对小鼠子宫生长发育及其相关基因表达的影响

目的：通过分析黄体生成素(LH)受体基因敲除小鼠子宫生长发育相关基因表达的改变,探讨LH对子宫生长发育的影响。方法：应用基因芯片和RT-PCR方法分析LH受体基因敲除鼠子宫基因表达。结果：155个基因表达改变超过3倍;与生长发育相关的基因中,10个基因表达上调、5个基因表达下调;细胞周期蛋白cyclin D基因上调、cyclin B基因下调,半定量RT-PCR分析证实了细胞周期蛋白基因表达的变化,表明LH受体基因敲除鼠子宫细胞生长发生阻滞,21 d雌二醇和孕酮替代疗法不能够使这些基因表达的改变完全恢复正常。结论：LH除促进卵巢类固醇激素合成调控子宫生长发育外,还对子宫生长发育直接起作用。     

GDF-5基因活化基质体内转染修复兔退变椎间盘的实验研究

目的通过GDF5基因活化基质体内转染兔退变椎间盘,观察其修复效果。方法脂质体介导的pcDNA3.1(+)/GDF-5重组质粒混入Ⅰ型胶原支架,置入兔退变椎间盘;实验分为GAM组,普通支架组,脂质体对照组,2个月后RT-PCR和Western blot观察椎间盘髓核细胞GDF-5基因和蛋白表达的稳定性,间苯三酚法检测髓核蛋白多糖含量,流式细胞仪检测细胞凋亡率来观察修复效果。结果 RT-PCR结果显示术后2个月GDF-5基因稳定表达。GAM组蛋白多糖含量高于另外两组(0.05),空白支架组和对照组之间没有差异(=0.601)。GAM组髓核细胞凋亡率明显低于另外两组(0.01),空白支架组和对照组之间没有差异(=0.902)。结论利用GAM可以有效的进行GDF-5基因体内转染并表达,从而修复退变椎间盘。     

Activation and differentiation antigen expression in B-cell non-Hodgkin's lymphoma

In an attempt to establish whether extended immuno-phenotyping allows more accurate definition of subgroups of B-cell non-Hodgkin's lymphoma (NHL) we have stained a series of 145 cases with a large panel of monoclonal antibodies that recognize B-cell differentiation and activation antigens. No antigen was expressed by all cases. The B-cell histogenesis in many cases could be confirmed only by using a panel of immunoglobulin and pan B-cell markers. There was marked phenotypic heterogeneity within and between major groups of B-cell NHL as delineated by the Kiel classification although the differentiation antigens CD5 (lymphocytic and centrocytic NHL) and OKT10 (plasma cell tumours) were more often expressed by certain morphological groups. The activation antigens 4F2 and transferrin receptor were expressed more strongly and more often by high grade NHL but other activation antigens (CD23 and CD25) were not more frequently associated with these tumours. Extended phenotyping may be of value in improving the understanding of biological abnormalities and processes involved in B-cell NHL, but we conclude that a limited panel of markers (CD3, CD5, CD22, CD45, IgM, kappa, and lambda) should be sufficient for routine diagnosis and classification of most cases.     

p53 tumour suppressor gene protein expression in early and advanced gallbladder carcinoma

 

Aims:

Gallbladder carcinoma is one of the most frequent malignant tumours occurring in Chile and the mortality rate in both sexes ranks among one of the highest in the world. Mutation of p53 tumour suppressor gene has been demonstrated in many tumours. Our aim was to determine protein expression of p53 gene in early and advanced gallbladder carcinoma.  

Methods and results:

Protein expression of gene p53 was studied by immunohistochemical means in 191 gallbladder carcinomas (157 primary tumours, 34 metastases) and 25 controls. In 86 out of 191 cases (45%), protein expression of gene p53 was observed. Differences related to sex, age, or race were not observed. All gallbladder controls were negative. Twenty-five per cent of well-differentiated tumours were p53 positive, while moderate or poorly differentiated carcinomas reached 50% ( P  = 0.04). p53 expression was observed in 23.5% of early carcinomas and in 48.2% of advanced carcinomas ( P  = 0.01). No differences between primary tumours and metastasis were demonstrated.  

Conclusions:

Protein expression of p53 tumour suppressor gene is observed in 45% of gallbladder carcinomas. The absence of expression in controls and in normal mucosa adjacent to tumours suggests its utility in differentiating atypical gallbladder epithelia from neoplastic lesions.