Expression of the ret proto-oncogene product in human normal and neoplastic tissues of neural crest origin

The histological localization of the ret proto-oncogene (proto-ret) product was examined in neural crest-derived and neuronal tissues together with their neoplastic counterparts by immunohistochemistry using a polyclonal antibody. Schwann cells, neurons, sympathetic ganglia, and cells of the adrenal medulla were positive for the proto-ret product, whereas melanocytes were negative. Positive results were obtained from neural crest-derived tumours such as schwannoma (69 per cent, 11/16), neurofibroma (59 per cent, 13/22), neuroblastoma (80 per cent, 4/5), phaeochromocytoma (100 per cent, 3/3) and medullary thyroid carcinoma (100 per cent, 3/3). The antibody reacted with all of the 22 astrocytomas examined. With negative proto-ret expression in melanocytic tumours, proto-ret expression was considered to correlate with the differentiation of some lineages of neural crest-derived cells.     

乳腺及乳腺外Paget病的HER2基因扩增比较及其生物学意义

HER2基因是乳腺癌进行靶向治疗的靶点[1-3].乳腺Paget病(特殊类型的乳腺癌)是一种较少见的乳头、乳晕区恶性上皮性肿瘤[4].乳腺外Paget病是一种较少见的特殊类型的癌性疾病,它以表皮内具有透明胞质的Paget细胞为特征.我们采用荧光原位杂交(FISH)技术及免疫组织化学EnVision法检测40例乳腺Paget病及30例乳腺外Paget病的HER2基因状态,探讨HER2基因的扩增情况及其生物学意义.     

Expression of the RET proto-oncogene in human Embryos

The patterns of RET proto-oncogene expression in mouse, rat, and chicken and the anomalies observed in targeted RET mutants suggest that RET plays a major role in development of mouse enteric nervous system and in kidney organogenesis. Here, we report on in situ hybridization studies describing the pattern of RET proto-oncogene expression during early development of human embryos between 23 and 42 days. We show that the RET gene is expressed in the developing kidney (nephric duct, mesonephric tubules, and ureteric bud), the presumptive enteric neuroblasts of the developing enteric nervous system, cranial ganglia (VII+VIII, IX, and X) and in the presumptive motor neurons of the spinal cord. Yet, despite the high level of RET gene expression in the kidney and in the motor neurons of the developing central nervous system in human embryos, only rare cases with renal agenesis have been reported in Hirschsprung disease patients, and no clinical evidence of spinal cord involvement has been shown in patients carrying RET germline mutations (i.e., multiple endocrine neoplasia syndromes and Hirschsprung disease). Am. J. Med. Genet. 80:481–486, 1998. © 1998 Wiley-Liss, Inc.     

Expression of the chemokine receptor CXCR2 in normal and neoplastic neuroendocrine cells

BACKGROUND: Chemokines effect their proinflammatory and growth regulatory roles through interaction with serpentine receptors. One such receptor, CXCR2, binds multiple CXC chemokines, including interleukin 8, GRO-alpha, GRO-beta, GRO-gamma, and NAP-2. We have previously identified CXCR2 expression on myeloid cells, notably mature granulocytes, and projection neurons. OBJECTIVE: To determine the expression of CXCR2 by cells of the neuroendocrine system. DESIGN: Archival specimens from normal neuroendocrine tissues and their malignant counterparts were analyzed by immunohistochemistry with monoclonal antibodies specific for CXCR1 and CXCR2. RESULTS: Immunohistochemical analysis revealed high-level expression of CXCR2 by cells in the pituitary, adrenal medulla, pancreatic islets, thyroid C cells, scattered Kulchitsky cells in the bronchi, and counterpart neuroendocrine cells in the stomach, small bowel, colon, and appendix. Neuroendocrine neoplasms that demonstrated high-level CXCR2 expression included (1) primary carcinoids localized to the stomach, small bowel, colon, appendix, fallopian tube, ovary, and lung; (2) atypical carcinoids of the lung; (3) metastatic carcinoids; (4) pituitary adenomas; (5) pheochromocytomas; and (6) medullary carcinomas of the thyroid. Small cell lung carcinomas, large cell neuroendocrine carcinomas of the lung, small cell carcinoma of the cervix, Merkel cell carcinomas, neuroblastomas, and malignant melanomas lacked evidence of CXCR2 expression. CONCLUSIONS: The expression of CXCR2 by normal neuroendocrine cells and neoplastic counterparts that have retained phenotypic features of this differentiation program suggests that chemokines may play an important role in functions that are characteristic of this cell type. In addition, this raises the possibility that chemokines may modulate secretion of biologically active products of these cells and their neoplastic counterparts.     

The proto-oncogene Vav product is constitutively tyrosine-phosphorylated in normal human immature T cells

The proto-oncogene Vav product is markedly tyrosine-phosphorylated after the recruitment of various receptors of cells of hematopoietic origin, including mature T cells. Recent studies on Vav-deficient mice have clearly implicated the product of the proto-oncogene Vav in intrathymic T cell development. Vav tyrosine phosphorylation is probably crucial to connect early tyrosine kinase(s) to downstream molecular events leading to cell division and maturation that occur in the thymus. We investigated the tyrosine phosphorylation of Vav in human thymocytes. Immunoblotting experiments demonstrate that, as in mature T cells, tyrosine phosphorylation of Vav is induced following thymocyte stimulation through the T cell receptor. The main observation, however, is that an important fraction of cellular Vav is constitutively tyrosine-phosphorylated in freshly isolated cells. This phenomenon takes place apparently both in the CD4⁺CD8⁺ and the more mature CD4⁺CD8^? and CD4^?CD8⁺ thymocyte cell subsets. Co-immunoprecipitation experiments showed, moreover, that a small amount of Vav is engaged in the multimolecular complex that includes elements of the T cell receptor and the T cell specific ZAP-70 tyrosine kinase. Altogether, these data suggest that a critical pathway for T cell development in the human thymus likely involves the permanent activation of Vav in vivo.     

Plasminogen activation in human leukemia and in normal hematopoietic cells

The active process of pericellular proteolysis is central in tumor invasion, and in particular the essential role of the urokinase-type plasminogen activator (uPA) is well established. uPA-mediated plasminogen activation facilitates cell migration and invasion through extracellular matrices by dissolving connective tissue components. uPA, its receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1) are enriched in several types of tumors. The importance of proteolysis and especially plasminogen activation is less clear in hematopoietic malignancies than in solid tumors. However, patients with leukemia have an increased tendency to bleeding, not always attributable to thrombocytopenia, and tissue infiltration by leukemic cells, processes in which plasminogen activation may be involved. Several studies have indicated that plasminogen activators (PAs) are highly expressed by cultured leukemia cells. Furthermore, differing from adherent tumor cells, leukemic cells have an enhanced capacity to activate pro-uPA and mainly the active form of uPA is released to culture medium. Ex vivo studies have shown that uPAR, uPA and its inhibitors can be found on the surface of normal blood cells and on the blast cell surfaces from patients with acute leukemia as well as from plasma samples. Elevated levels of PAs and their inhibitors have been detected in leukemic cell lysates. Few studies have tried to demonstrate a correlation between prognosis of leukemia and levels of plasminogen activators. More in vivo studies are needed to show, if any of the factors of the plasminogen activation process can be used as tools in subclassification or as markers for prognosis in leukemia. This review article will focus on the in vivo studies of plasminogen activation in leukemia and will present several in vitro findings on PAs in normal leukocytes and leukemic cell lines.     

Fluctuation of HER2 Expression in Breast Carcinomas during the Menstrual Cycle

The hormonal milieu at time of tumor surgery seems to have a significant impact on survival in premenopausal breast cancer patients. Indeed, surgery performed during the follicular phase of the menstrual cycle was suggested to correlate with a poor prognosis. To investigate the relationship between prognosis and menstrual cycle at time of surgery, we analyzed the expression of some markers associated with tumor aggressiveness, such as the hormone receptors, HER2, p53, Bcl2, and cathepsin D in breast carcinomas obtained from 198 premenopausal women who underwent surgery during different phases of the menstrual cycle. HER2 overexpression was found to fluctuate in hormone receptor-positive tumors. In actual fact, 20% of the tumors removed during the follicular phase scored HER2-positive, versus 8% of those removed during the luteal phase. Similarly, a number of hormone receptor-positive tumor specimens, obtained from the same patients during follicular and luteal phases, were scored HER2-positive when the sample was removed during the follicular phase and HER2-negative when removed in the luteal phase. Southern blot analysis of the HER2 gene indicated that, in hormone receptor-positive cases, the overexpression of HER2 is often not associated with gene amplification. The finding that overexpression of the HER2 gene, associated with tumor aggressiveness, can fluctuate according to the hormonal milieu may explain the increased survival of patients operated during the luteal phase. It is also relevant to the selection and treatment of patients most likely to benefit from anti-HER2 antibody therapy.     

Expression of ras proto-oncogene related protein p21 in normal human skin and cutaneous tumours.

The cellular proto-oncogene, ras, is known to play an important role in the regulation of cell growth and proliferation in normal and malignant conditions. The present study was undertaken to immunohistochemically examine the expression of ras protooncogene product p21 in normal human skin and some cutaneous tumours. In normal skin, the expression of p21 was found in sweat glands, sebaceous glands, capillary endothelium, and smooth muscles, while epidermis was devoid of reaction product. Keratoacanthoma and the granular cells of verruca vulgaris were immunoreactive to the antibody for p21. Bowen's disease and squamous cell carcinoma were positive for p21, but basal cell carcinoma and seborrheic keratosis were negative. In mammary and extramammary Paget's diseases, the immunoreactivity was inconsistent. The expression of p21 in malignant melanoma cells was intense, whereas normal melanocytes and nevus cells were devoid of the expression. These results suggest that the expression of p21 does not correlate with nuclear anaplasia and malignant behaviour of cutaneous tumours.     

Functional characterization of podia formation in normal and malignant hematopoietic cells

Hematopoietic cells extend multiple podia of yet unknown function. Our morphological studies using scanning electron microscopy and functional studies using time-lapse video microscopy suggest that podia formed by CD34+ hematopoietic stem cells (HSC) on the bone marrow stroma component fibronectin are characteristic of lamellipodia at the leading edge and uropodia at the trailing edge, cytoskeletal structures that have previously been shown to be responsible for cell locomotion of lymphocytes. In the leukemic cells studied here, stroma-derived factor-1alpha (SDF-1alpha) led to a significant eightfold increase in transmigration (BCR-ABL-positive BV173 leukemia cell line; P<0.05) and podia formation in all BCR-ABL-positive leukemic cell lines studied (BV173, K562, 32Dp210) and in two of three BCR-ABL-negative lines (HL60, 32D, not KG1a). We could show that SDF-1alpha exposure led to a down-regulation of the gene expression of the chemokine receptors CCR4, CXCR4, and CXCR5, which are associated with cell motility and podia formation, indicating a negative feedback control. In BCR-ABL-positive leukemic cells, the effects of SDF-1alpha on podia formation and cell migration were independent of BCR-ABL-tyrosine kinase activity. Our data are compatible with the hypothesis that formation of specific podia by hematopoietic cells is associated with egression of these cells from the bone marrow.     

Expression of human argininosuccinate synthetase in murine hematopoietic cells in vivo

As part of an effort to develop a model system for somatic gene therapy, a human argininosuccinate synthetase (AS) cDNA has been introduced into two gag⁺ retroviral vectors, and high titer clones were obtained for both constructs. The presence of proviral DNA sequences was detected in individual spleen colonies after infection of primary murine marrow cells with each virus. Mice were reconstituted for long-term survival with marrow infected with one virus, and they demonstrated elevated levels of AS expression in peripheral blood for up to eight weeks posttransplantation.     

HER2状态与脑膜瘤分级及复发的相关性

目的 探讨HER2、细胞增殖指标Ki-67、胸苷激酶1(TK1)与脑膜瘤分级和良性脑膜瘤复发的相关性.方法 按2007年WHO神经系统肿瘤分类分级标准选取良性未复发的脑膜瘤、不典型脑膜瘤及恶性脑膜瘤石蜡标本各20例,并选取间期良性复发的脑膜瘤石蜡标本20例,将实验对象分为4组:良性非复发组、良性复发组、不典型组及恶性组.采用免疫组织化学MaxVision法对4组石蜡切片进行HER2、Ki-67、TK1蛋白的检测;并运用双色荧光原位杂交(FISH)法检测HER2蛋白表达阳性样本的HER2基因扩增情况.结果 免疫组织化学:(1)良性非复发组、良性复发组、不典型组和恶性组脑膜瘤的HER2阳性的例数分别为3例(15%)、6例(30%)、7例(35%)和10例(50%),随恶性程度增加,HER2蛋白阳性率升高(P<0.05);良性复发组HER2阳性率高于良性非复发组(P<0.05);(2)良性非复发组Ki-67和TK1的标记指数(U)均分别低于不典型组和恶性组(P<0.05);不典型组低于恶性组(P<0.05),随着恶性程度增高,Ki-67、TK1 LI升高;且良性复发组高于良性非复发组(P<0.05);(3)HER2与Ki-67、TK1均呈正相关(均P<0.01),Ki-67与TK1呈正相关(P<0.05).FISH法:(1)在26例HER2蛋白阳性表达的脑膜瘤组织中HER2/neu基因的扩增率为26.9%(7/26);HER2蛋白表达3+、2+者HER2/neu基因扩增比例分别为3,/4和4/6,均多于1+者(均P<0.01),3+者与2+者比较差异无统计学意义(P>0.05).(2)26例HER2蛋白阳性表达的脑膜瘤组织中9例存在17号染色体的非整倍性(34.6%),但HER2蛋白表达1+、2+、3+者间17号染色体的非整倍性出现率差异均无统计学意义(均P>0.05).结论 HER2阳性且Ki-67或TK1 LI高提示脑膜瘤恶性程度较高或复发可能性较大.脑膜瘤组织中存在HER2/neu基因的扩增.HER2、Ki-67和TK1蛋白可能可以作为临床判断脑膜瘤生物学行为的参考指标.     

In vivo anti-tumor activity of murine hematopoietic stem cells expressing a p185HER2-specific chimeric T-cell receptor gene

We have confirmed efficient anti-tumor activities of the peripheral lymphocytes transduced with a p185HER2-specific chimeric T-cell receptor gene both in murine and in human in our previous studies. To further test the feasibility of chimeric T-cell receptor in a bone marrow transplantation model, we first, made two murine tumor cell lines: MT901 and MCA-205, to express human p185HER2 by retroviral gene transduction. Murine bone marrow cells were retrovirally transduced to express the chimeric T-cell receptor and gene-modified bone marrow cells were transplanted into lethally irradiated mouse. Six months post transplantation, p185HER2-positive tumor cells:MT-901/HER2 or MCA-205/ HER2 was subcutaneously or intravenously injected to make mouse models simulating primary breast cancer or pulmonary metastasis. The in vivo anti-tumor effects were monitored by the size of the subcutaneous tumor or counting the tumor nodules in the lungs after India ink staining. The size of the subcutaneous tumor was significantly inhibited and the number of pulmonary nodules were significantly decreased in mouse recipients transplanted with chimeric T-cell receptor modified bone marrow cells compared with the control group. Our results suggest the efficient in vivo anti-tumor activities of chimeric T-cell receptor gene modified bone marrow cells.     

Immunohistochemical detection of the c-erbB-2 proto-oncogene product in normal, benign and malignant cartilage tissues

Benign and malignant cartilage tumours as well as normal cartilage were stained immunohistochemically with antibodies raised to a synthetic peptide from the sequence of the c-erbB-2 protein. Positive staining was present in 18/23 of the chondrosarcomas and in one case of osteochondroma. Normal and benign neoplastic cartilage tissues revealed negative results. It is concluded that expression of the c-erbB-2 protein may contribute to cell transformation in chondrosarcomas; it is not apparent whether the expression of c-erbB-2 protein in chondrosarcomas characterizes a subpopulation of different prognostic significance.     

HER2高表达胃癌细胞中miR-4728-3p表达及生物信息学分析

目的 探讨HER2高表达的胃癌细胞中miR-4728-3p表达状况及其调控靶基因所涉及的信号通路,旨在初步分析miR-4728-3p在胃癌中的作用机制及其与HER2的相关性.方法 首先采用Real-time PCR技术检测胃癌细胞株NCI-N87中miR-4728-3p及HER2 mRNA,然后通过miRanda、DIANA-microT、Targetscan和Targetmine软件预测miR-4728可能的靶基因,并通过DAVID数据库进行靶基因功能富集分析及信号转导通路富集分析.结果 miR-4728-3p及HER2 mRNA在胃癌细胞中均高表达,二者呈正相关(r=0.990,P=0.000).miR-4728-3p预测靶基因共有54个,靶基因功能主要富集于转录活性调节(P=0.014)、DNA结合(P=0.019)及蛋白质磷酸化氨基酸结合(P=0.036)等分子功能,RNA聚合酶Ⅱ启动子的转录调控(P=0.001)、转录调控(P=0.003)及细胞内信号级联(P=0.021)等生物学过程以及轴突部分(P=0.008)等细胞组分上;信号转导通路则主要富集于肿瘤通路(P=0.013)和卵母细胞减数分裂通路(P=0.041).结论 miR-4728-3p在HER2高表达的胃癌细胞中表达上调,二者表达呈正相关;生物信息学分析提示miR-4728-3p通过调控其靶基因参与胃癌的发生发展.