Wild-type p53-mediated down-modulation of interleukin 15 and interleukin 15 receptors in human rhabdomyosarcoma cells.

We recently reported that rhabdomyosarcoma cell lines express and secrete interleukin 15 (IL-15), a tightly regulated cytokine with IL-2-like activity. To test whether the p53-impaired function that is frequently found in this tumour type could play a role in the IL-15 production, wild-type p53 gene was transduced in the human rhabdomyosarcoma cell line RD (which harbours a mutated p53 gene), and its effect on proliferation and expression of IL-15 was studied. Arrest of proliferation was induced by wild-type p53; increased proportions of G1-arrested cells and of apoptotic cells were observed. A marked down-modulation of IL-15 expression, at both the mRNA and protein level, was found in p53-transduced cells. Because a direct effect of IL-15 on normal muscle cells has been reported, the presence of IL-15 membrane receptors was studied by cytofluorometric analysis. Rhabdomyosarcoma cells showed IL-15 membrane receptors, which are down-modulated by wild-type p53 transfected gene. In conclusion, wild-type p53 transduction in human rhabdomyosarcoma cells induces the down-modulation of both IL-15 production and IL-15 receptor expression.     

Genetic modeling of human rhabdomyosarcoma

Rhabdomyosarcoma, a malignancy showing features of skeletal muscle differentiation, is the most common soft tissue sarcoma of childhood. The identification of distinct clinical presentation patterns, histologic tumor types, and risk groups suggests that rhabdomyosarcoma is a collection of highly related sarcomas rather than a single entity. In an effort to understand this seemingly heterogeneous malignancy, we constructed a genetically defined but malleable model of rhabdomyosarcoma by converting less differentiated human skeletal muscle cell precursors (SkMC) and committed human skeletal muscle myoblasts (HSMM) into their malignant counterparts by targeting pathways altered in rhabdomyosarcoma. Whereas the two cell types were both tumorigenic, SkMCs gave rise to highly heterogeneous tumors occasionally displaying features of rhabdomyosarcoma, whereas HSMMs formed rhabdomyosarcoma-like tumors with an embryonal morphology, capable of invasion and metastasis. Thus, despite introducing the same panel of genetic changes, altering the skeletal muscle cell of origin led to different tumor morphologies, suggesting that cell of origin may dictate rhabdomyosarcoma tumor histology. The ability to now genetically induce human rhabdomyosarcoma-like tumors provides a representative model to dissect the molecular mechanisms underlying this cancer.     

Mcl-1 is an anti-apoptotic factor for human hepatocellular carcinoma

Defects in apoptosis signaling in hepatocytes contribute to tumorigenesis in hepatocellular carcinoma (HCC). In addition, treatment with chemotherapeutic drugs is often ineffective in HCC patients due to the apoptosis resistance of cancer cells. Anti-apoptotic members of the Bcl-2 family, including myeloid cell leukemia-1 (Mcl-1), which regulate intrinsic apoptosis induction at the mito-chondrial level, are often overexpressed in human cancer, and are implicated with disease grade and prognosis. Yet, little is known about the role of Mcl-1 in HCC. In this study, we analyzed the relevance of Mcl-1 expression for the apop-tosis resistance of human HCC. Mcl-1 protein expression was considerably enhanced in human HCC tissue compared to adjacent non-tumor tissue. In addition, Mcl-1 was prominently expressed in various HCC cell lines. Mcl-1 basal expression is dependent on a functional phosphatidylinositol-3 kinase (PI3K)/Akt signaling pathway; treatment of the cells with a specific PI3 kinase inhibitor led to both decreased Mcl-1 expression and a sensitization towards chemotherapeutic drug-induced apoptosis. Furthermore, the hepatocyte growth factor and epidermal growth factor induced Mcl-1 expression in an Akt- and ERK-dependent manner. Finally, specific upregulation of Mcl-1 in HCC cells inhibited chemotherapeutic drug-induced apoptosis. Our data suggest that Mcl-1 is an important factor for the apoptosis resistance of human HCC, and constitutes an interesting target for HCC therapy.     

激活NGF/trkA信号传导通路引起NB细胞良性分化的研究

目的 :观察神经生长因子 (nervegrowthfactor ,NGF)与其高亲和性受体 (trkA)信号传导通路的激活 ,对神经母细胞瘤 (neu roblastoma ,NB)良性分化的影响。方法 :利用脂质体转染法将trkAcDNA重组质粒转染入人神经母细胞瘤SH SY5Y细胞系中 ,应用RT PCR技术鉴定转染后基因的表达 ,比较转染前后SH SY5Y细胞的分化程度及表达trkA的SH SY5Y细胞用NGF处理前后的分化程度。结果 :成功转染trkA基因并在SH SY5Y细胞中稳定表达 ,对照组及空载体组trkAPCR率分别为 0 43± 0 0 73 8和 0 44± 0 0 9,实验组为 2 69± 0 2 2 ,实验组与前两组比较差异有统计学意义 ,P <0 0 1;转染后SH SY5Y细胞的分化程度明显增加 ,用NGF处理后 ,其分化程度进一步增加。分化细胞的百分率实验组 1为 3 7 69± 1 75 ,实验组 2为 2 6 2 8± 1 3 4,对照组 18 43 5± 1 2 5 ,空载体组 17 61± 1 69。实验组 1与对照组及空载体组相比差异有统计学意义 ,P <0 0 1;实验组 2与对照组及空载体组相比差异有统计意义 ,P <0 0 5 ;实验组 2和实验组 1相比差异有统计学意义 ,P <0 0 1。结论 :NGF/trkA信号传导通路的激活能够引起NB细胞的良性分化 ,这一传导通路的激活可能是NB细胞良性逆转的重要因素。     

神经生长因子及其两种受体与子宫颈原位癌的相关性研究

目的　探讨神经生长因子 (NGF)及两种受体 (p75和 Trk A)与子宫颈原位癌的关系。方法　采用免疫组化 S- P法和原位杂交法检测石蜡包埋子宫颈组织中 NGF、p75和 Trk A的蛋白和 m RNA的表达 ,包括研究组子宫颈鳞状上皮原位癌 (SCIS) 30例 ,对照组正常上皮组织 (NSE) 13例 ,中、重度不典型增生 (DSEH) 13例和浸润癌(ISEC) 14例。结果　 NGF及其两种受体蛋白随着子宫颈病变进展其共表达逐渐减少 ,在 ISEC组其共同阳性表达率下降为 14 .3% ,与 NSE、DSEH、SCIS各组相比差异均有显著性 (P<0 .0 5 ) ;NGF与 p75蛋白以及 Trk A与 p75蛋白的共同阳性表达率在 ISEC组中分别下降为 4 2 .9%和 14 .3% ,SCIS组与 ISEC组相比差异有显著性 (P<0 .0 5 )。NGF、p75和 Trk A的 m RNA在各组组织中的表达率差异均无显著性。结论　子宫颈原位癌是癌变过程中一个相对特殊阶段的癌。 NGF及其受体的表达缺失程度、NGF- p75和 p75 - Trk A间相互作用的减少在原位癌是维持现状还是进展为浸润癌过程中起着重要作用     

A nude mice model of human rhabdomyosarcoma lung metastases for evaluating the role of polysialic acids in the metastatic process

PSA is an oncodevelopmental antigen usually expressed in human tumors with high metastatic potential. Here we set up a metastatic model in nude mice by using TE671 cells, which strongly express PSA-NCAM. We observed the formation of lung metastases when TE671 cells were injected intravenously, intramuscularly, and intraperitoneally, but not subcutaneously. Intraperitoneal injections also induced peritoneal carcinosis, ascites, and liver metastases. To evaluate the putative role of PSA in the metastatic process we used a specific cleavage of PSA on NCAM by endoneuraminidase-N on intraperitoneal primary tumors. Mice with primary intramuscular tumors were taken as control. Repeated injections of endoneuraminidase-N led to a decrease in PSA expression in primary intraperitoneal nodules and ascites but not in intramuscular primary tumors. Endoneuraminidase-N also increased the delay in ascitic formation and decreased the number of lung or liver metastases in the case of intraperitoneal tumors but not in the case of intramuscular tumors. When metastases occurred in endoneuraminidase-N injected animals, they strongly expressed PSA-NCAM. Therefore, we established a relationship between PSA expression on the surface of primary tumor cells and the metastatic process.     

Endothelin-3 production by human rhabdomyosarcoma: a possible new marker with a paracrine role

Several autocrine and paracrine growth factor circuits have been found in human rhabdomyosarcoma cells. In this study we show that endothelin-3 (ET-3), a vasoactive peptide, is produced by human rhabdomyosarcoma cell lines, whereas it is not expressed by human sarcoma cell lines of non-muscle origin. We did not find evidence of a significant autocrine loop; nevertheless ET-3 produced by rhabdomyosarcoma cells can act as a paracrine factor, since it promotes migration of endothelial cells. Moreover ET-3 is present in plasma of mice bearing xenografts of human rhabdomyosarcoma cells, and may be potential new marker of the human rhabdomyosarcoma to be studied further.     

An adolescent with rhabdomyosarcoma during pregnancy

We report the case of a 15-year-old girl with a large gluteal and perineal rhabdomyosarcoma diagnosed at 24 weeks of pregnancy, whose management posed a great clinical dilemma for us. The patient refused to consider a therapeutic abortion, so we opted for a customized treatment with mild doses of chemotherapy administered weekly to control tumor growth while minimizing fetal and perinatal complications. After the delivery of a healthy female, we adopted a more intensive chemotherapy regimen plus irradiation. Despite an initially good response, the disease unfortunately progressed and the patient died of her disease.     

The challenging role of radiation therapy for very young children with rhabdomyosarcoma

PURPOSE: To evaluate local control and toxicity for very young children treated with multimodality therapy for rhabdomyosarcoma (RMS). METHODS AND MATERIALS: From 1990 to 2004, 20 patientsor=1 year after diagnosis (15) in terms of mild, moderate, or severe deficits. RESULTS: Median follow-up was 33 months for survivors and 23 months for all patients. Two-year actuarial local control, event-free survival, disease-specific survival, and overall survival were 84%, 52%, 74%, and 62%, respectively. All patients who began EBRT相似文献   

Expression of NGF in hepatocellular carcinoma cells with its receptors in non-tumor cell components

Nerve growth factor (NGF) is suggested to have a role in tumor progression in addition to its role in differentiation and survival of neuronal cells. We investigated expression of NGF and its receptors, TrkA and p75NTR, in hepatocellular carcinomas (HCCs). Although hepatocytes and hepatic stellate cells (HSCs) showed respectively weak and intense NGF immunostaining in the background livers of patients suffering from liver cirrhosis (LC) or chronic hepatitis (CH), intense staining was demonstrated in HCC cells of 33 of 54 (61.1%) tumors. RT-PCR detected NGF mRNA in 7 freshly-isolated HCC samples, and in 2 of 4 cases, in which both background livers and tumors could be analyzed, NGF mRNA was more abundant in the tumors than the background livers. TrkA was detected in the smooth muscle cells of hepatic arteries, but it was negative in tumor cells as well as non-neoplastic hepatocytes. p75NTR and alpha-smooth muscle actin (alphaSMA) was expressed in HSCs in the background liver and fibroblast-like cells in stromal septa, whereas HSCs within the HCC tissues were mostly negative for p75NTR but positive for alphaSMA. This suggests that HSCs in HCC have a different property from those in background livers. Furthermore, the stromal septa contained abundant nerve fibers, which may be related to the increased NGF expression in HCC cells. NGF and its receptors are then thought to have a role in cellular interactions involving HCC cells, HSCs, arterial cells and nerve cells in HCC tissues.     

The role of oestrogen and progesterone receptors in human mammary development and tumorigenesis

A relatively small number of cells in the normal human mammary gland express receptors for oestrogen and progesterone (ER and PR), and there is almost complete dissociation between steroid receptor expression and proliferation. Increased expression of the ER alpha (ERalpha) and loss of the inverse relationship between receptor expression and proliferation occur at the very earliest stages of tumorigenesis, implying that dysregulation of ERalpha expression contributes to breast tumour formation. There is evidence also for alterations in the ratio between the two PR isoforms in premalignant breast lesions. Elucidation of the factors mediating the effects of oestradiol and progesterone on development of the normal breast and of the mechanisms by which expression of the ERalpha and the PR isoforms is controlled could identify new targets for breast cancer prevention and improved prediction of breast cancer risk.     

Migration-promoting role of VEGF-C and VEGF-C binding receptors in human breast cancer cells

Vascular endothelial growth factor C (VEGF-C) is a lymphangiogenic factor over-expressed in highly metastatic, cyclooxygenase (COX)-2 expressing breast cancer cells. We tested the hypothesis that tumour-derived VEGF-C may play an autocrine role in metastasis by promoting cellular motility through one or more VEGF-C-binding receptors VEGFR-2, VEGFR-3, neuropilin (NRP)-1, NRP-2, and integrin alpha9beta1. We investigated the expression of these receptors in several breast cancer cell lines (MDA-MB-231, Hs578T, SK-BR-3, T-47D, and MCF7) and their possible requirement in migration of two VEGF-C-secreting, highly metastatic lines MDA-MB-231 and Hs578T. While cell lines varied significantly in their expression of above VEGF-C receptors, migratory activity of MDA-MB-231 and Hs578T cells was linked to one or more of these receptors. Depletion of endogenous VEGF-C by treatments with a neutralising antibody, VEGF-C siRNA or inhibitors of Src, EGFR/Her2/neu and p38 MAP kinases which inhibited VEGF-C production, inhibited cellular migration, indicating the requirement of VEGF-C for migratory function. Migration was differentially attenuated by blocking or downregulation of different VEGF-C receptors, for example treatment with a VEGFR-2 tyrosine kinase inhibitor, NRP-1 and NRP-2 siRNA or alpha9beta1 integrin antibody, indicating the participation of one or more of the receptors in cell motility. This novel role of tumour-derived VEGF-C indicates that breast cancer metastasis can be promoted by coordinated stimulation of lymphangiogenesis and enhanced migratory activity of breast cancer cells.