肾透明细胞癌Caki-1细胞系差异表达基因的生物信息学分析

目的比较肾透明细胞癌Caki-1细胞系与正常肾上皮细胞系ASE-5063中的差异表达基因（DEGs）,寻找潜在的肾透明细胞癌特异性分子标志物。 方法利用GEO数据库自带的GEO2R在线分析工具分析基因芯片GSE78179,将筛选出的DEGs分别导入Metascape、STRING以及Cytoscape进行综合分析并筛选出核心基因。最后使用FunRich等软件对筛选出的核心基因进行GO和KEGG富集分析。 结果共筛选出562个DEGs,其中上调基因345个,下调基因217个。进一步使用MCODE筛选出36个关键基因,GO功能分析发现这些基因与细胞粘附分子活性、趋化因子活性、细胞通讯和信号转导等密切相关;KEGG通路富集结果则表明差异基因主要集中在趋化因子信号通路、TNF信号通路以及NF-κB信号通路等多种与肿瘤相关的通路上。 结论运用生物信息学方法筛选出肾透明细胞癌Caki-1细胞系中DEGs,其中数个核心基因广泛参与多种肿瘤的病理进程,但尚未在肾透明细胞癌有相关研究报道,提示其可能是治疗肾透明细胞癌的潜在靶点。     

Chilean propolis: antioxidant activity and antiproliferative action in human tumor cell lines

Propolis, a natural product derived from plant resins collected by honeybees, has been used for thousands of years in traditional medicine all over the world. The composition of the propolis depends upon the vegetation of the area from where it was collected and on the bee species. In this study, we investigated the antioxidant activity of a propolis sample, provided by NATURANDES-CHILE, collected in a temperate region of central Chile. In addition, this natural compound was tested for its antiproliferative capacity on KB (human mouth epidermoid carcinoma cells), Caco-2 (colon adenocarcinoma cells) and DU-145 (androgen-insensitive prostate cancer cells) human tumor cell lines. Results showed that this Chilean propolis sample exhibits interesting biological properties, correlated with its chemical composition and expressed by its capacity to scavenge free radicals and to inhibit tumor cell growth.     

Influence of retinoic acid on adhesion complexes in human hepatoma cells: a clue to its antiproliferative effects

Retinoic acid exerts antiproliferative and differentiative effects in normal and transformed in vitro hepatocytes. In order to verify whether these effects are related to a modulation of adhesion molecules, we used Western blot analysis and immunofluorescence microscopy to investigate the E-cadherin/β-catenin complex, the main system of adherens junctions, and the occludin/ZO-1 complex present in the tight junctions in HepG2 cells cultured in the presence or absence of retinoic acid. Results showed that retinoic acid treatment increases the amount of β-catenin bound to E-cadherin by decreasing its tyrosine-phosphorylation level. Similar results were obtained with the tight junction system, in which the amount of occludin/ZO-1 complex is increased by a similar mechanism that reduced the level of ZO-1 phosphorylation on tyrosine. Immunofluorescence images also confirm these results, showing the localization on the cell surface of both adhesion complexes. Their insertion into the plasma membrane could be suggestive of an optimal reassembly and function of adherens and tight junctions in hepatoma cells, indicating that retinoic acid, besides inhibiting cell proliferation, improves cell-cell adhesion, sustaining or inducing the expression of a more differentiated phenotype.     

Resveratrol exerts its antiproliferative effect on HepG2 hepatocellular carcinoma cells, by inducing cell cycle arrest, and NOS activation

The stilbene resveratrol exerts antiproliferative and proapoptotic actions on a number of different cancer cell lines, through diverse mechanisms, including antioxidant effects, enzyme, growth factor and hormone receptor binding, and nucleic acid direct or indirect interactions. Although resveratrol accumulates in the liver, its effect on hepatocellular carcinoma has not been extensively studied. We have used the human hepatocyte-derived cancer cell line HepG2 to address the possible action of resveratrol on cell growth and to examine some possible mechanisms of action. Our results indicate that the stilbene inhibits potently cell proliferation, reduces the production of reactive oxygen species and induces apoptosis, through cell cycle arrest in G1 and G2/M phases. Furthermore it modulates the NO/NOS system, by increasing iNOS and eNOS expression, NOS activity and NO production. Inhibition of NOS enzymes attenuates its antiproliferative effect. These data could be of value in possible prevention or adjuvant treatment of hepatocellular carcinoma, through an increased consumption of resveratrol-rich foods and beverages.     

The human chromophobe cell renal carcinoma: its probable relation to intercalated cells of the collecting duct

In the present study we have examined ten cases of the chromophobe type renal cell carcinoma. This type of tumor is distinguished from the other carcinomas of the kidney with light cytoplasm (formerly called "hypernephroid") by (a) a positive Hale's iron colloid stain of the cytoplasm, (b) the occurrence of numerous invaginated vesicles within the cytoplasm that resemble the invaginated vesicles of intercalated cells of the collecting duct system, and (c) a positive immunoreaction of both the plasma membrane and the cytoplasm with antibodies to the epithelial membrane antigen (EMA) and carbonic anhydrase C (CAC), respectively. Unlike oncocytomas, which also express CAC and EMA, the chromophobe renal cell carcinoma does not express the erythrocyte anion exchanger band 3. These findings strongly indicate that chromophobe renal cell carcinomas as well as oncocytomas of the kidney are histogenetically related to the two populations of intercalated cells of the collecting duct system. Thus, both tumors represent examples of renal tumors which disprove the broadly accepted hypothesis that all epithelial tumors of the kidney are histogenetically related to the proximal tubule.     

Glutathione-S-transferase in human renal cell carcinoma

Homogenates of human renal cell carcinomas were tested for glutathione-S-transferase, an enzyme of normal proximal tubule cells. All tumors were positive; mean tumor fraction enzyme activity was 0.040 +/- 0.02 mumol/min/microgram protein. Glutathione-S-transferase activity in homogenates from normal kidney was 0.022 and 0.054 mumol/min/microgram protein. Finding similar levels of a major cytosolic enzyme in tumor and renal cortex confirms the origin of renal cell carcinoma in the proximal nephron. Glutathione-S-transferase, which binds carcinogens and steroids, may play a role in carcinogenesis and serve as a marker for this tumor.     

Protective role of retinoic acid from antiproliferative action of TNF-alpha on lung epithelial cells

Tumor necrosis factor (TNF)-alpha is a key molecule in lung inflammation. We have established the insulin-like growth factor binding protein 2 (IGFBP-2) as a marker associated with the growth arrest of lung alveolar epithelial cells (AEC). Here, we studied the effects of TNF-alpha on AEC proliferation and the putative protective role of retinoic acid (RA). We documented an antiproliferative action of TNF-alpha that was reversible only at 24 h and then became irreversible with induction of apoptosis. TNF-alpha treatment was associated with a dramatic induction of IGFBP-2. To discover the mechanism of action of IGFBP-2, we further tested the mitogenic potential of IGF-I to counteract TNF-alpha inhibition. Addition of IGF-I to the TNF-alpha containing medium did not stimulate proliferation, whereas des(1-3)IGF-I, an analog of IGF-I that bears low affinity for IGFBPs, was able to restore cell growth. Interestingly, we observed that RA abrogated TNF-alpha-induced growth arrest and that this effect was associated with a dramatic decrease in IGFBP-2 expression. These results suggest a protective role of RA from TNF-alpha antiproliferative action, through mechanisms involving modulation of IGFBP-2 production.     

Zebularine exerts its antiproliferative activity through S phase delay and cell death in human malignant mesothelioma cells

Malignant mesothelioma is an asbestos-related aggressive tumor and current therapy remains ineffective. Zebularine as a DNA methyltransferase (DNMT) inhibitor has an anti-tumor effect in several human cancer cells. The aim of the present study was to investigate whether zebularine could induce antiproliferative effect in human malignant mesothelioma cells. Zebularine induced cell growth inhibition in a dose-dependent manner. In addition, zebularine dose-dependently decreased expression of DNMT1 in all malignant mesothelioma cells tested. Cell cycle analysis indicated that zebularine induced S phase delay. Zebularine also induced cell death in malignant mesothelioma cells. In contrast, zebularine did not induce cell growth inhibition and cell death in human normal fibroblast cells. These results suggest that zebularine has a potential for the treatment of malignant mesothelioma by inhibiting cell growth and inducing cell death.     

Expression of cholinesterases in human kidney and its variation in renal cell carcinoma types

Despite the aberrant expression of cholinesterases in tumours, the question of their possible contribution to tumorigenesis remains unsolved. The identification in kidney of a cholinergic system has paved the way to functional studies, but details on renal cholinesterases are still lacking. To fill the gap and to determine whether cholinesterases are abnormally expressed in renal tumours, paired pieces of normal kidney and renal cell carcinomas (RCCs) were compared for cholinesterase activity and mRNA levels. In studies with papillary RCC (pRCC), conventional RCC, chromophobe RCC, and renal oncocytoma, acetylcholinesterase activity increased in pRCC (3.92 ± 3.01 mU·mg(-1), P = 0.031) and conventional RCC (2.64 ± 1.49 mU·mg(-1), P = 0.047) with respect to their controls (1.52 ± 0.92 and 1.57 ± 0.44 mU·mg(-1)). Butyrylcholinesterase activity increased in pRCC (5.12 ± 2.61 versus 2.73 ± 1.15 mU·mg(-1), P = 0.031). Glycosylphosphatidylinositol-linked acetylcholinesterase dimers and hydrophilic butyrylcholinesterase tetramers predominated in control and cancerous kidney. Acetylcholinesterase mRNAs with exons E1c and E1e, 3'-alternative T, H and R acetylcholinesterase mRNAs and butyrylcholinesterase mRNA were identified in kidney. The levels of acetylcholinesterase and butyrylcholinesterase mRNAs were nearly 1000-fold lower in human kidney than in colon. Whereas kidney and renal tumours showed comparable levels of acetylcholinesterase mRNA, the content of butyrylcholinesterase mRNA was increased 10-fold in pRCC. The presence of acetylcholinesterase and butyrylcholinesterase mRNAs in kidney supports their synthesis in the organ itself, and the prevalence of glycosylphosphatidylinositol-anchored acetylcholinesterase explains the splicing to acetylcholinesterase-H mRNA. The consequences of butyrylcholinesterase upregulation for pRCC growth are discussed.     

The enhancement of radiosensitivity in human esophageal squamous cell carcinoma cells by zoledronic acid and its potential mechanism

Esophageal squamous cell carcinoma (ESCC) has a low 5-year patient survival rate. Radiotherapy, as a preoperative or postoperative treatment of surgery, has a crucial role in improving local control and survival of ESCC. Various chemotherapeutic and biologic agents have been used as radio-sensitizers in combination with radiotherapy. Here, we demonstrate that zoledronic acid (ZOL) has a radio-sensitizing effect on ESCC cells. Exposure of ESCC cancer cells to ZOL plus radiation resulted in increased cell death through arresting the cell cycle between S and G2/M phases. ZOL appeared to inhibit proliferation, tube formation and invasion of endothelial cells. These anti-angiogenetic effects were more marked concurrently with irradiation. In addition, synergistic suppressive effects on VEGF expression were observed after combined treatment. Our data suggest that the combination of ZOL and radiation is a promising therapeutic strategy to enhance radiation therapy for ESCC patients.     

二氯乙酸对人肾癌细胞株A498侵袭及迁移的抑制作用研究

目的探讨二氯乙酸(DCA)对人肾癌细胞株A498侵袭及迁移的影响,并分析其机制。方法取人肾癌细胞株A498培养,分为阴性对照(等容积无菌生理盐水)组、DCA低、中、高(5、10、20 mmol/L)剂量组,培养48 h。Transwell小室实验检测侵袭能力,细胞划痕实验检测迁移能力,实时荧光定量聚合酶链反应(qRT-PCR)检测c-Jun氨基末端激酶(JNK)、钙粘附蛋白E(E-cadherin)、N-钙粘蛋白(N-cadherin)基因表达,Western blot检测蛋白表达及磷酸化JNK(p-JNK)。多组间比较采用单因素方差分析,组间两两比较采用SNK-q检验。结果与DCA高剂量组相比,DCA中、低剂量组、阴性对照组侵袭活性[(75.33±10.09)比(167.89±47.12)、(372.74±50.06)、(530.26±81.22)个/视野]、E-cadherin mRNA相对表达量(1.52±0.12比1.35±0.11、1.02±0.11、0.85±0.12)、E-cadherin蛋白相对表达量(1.32±0.19比0.89±0.14、0.37±0.08、0.13±0.03)均降低(P均<0.001);而迁移率[(10.05±2.31)﹪比(23.95±4.20)﹪、(36.26±5.01)﹪、(53.59±6.71)﹪]、N-cadherin mRNA蛋白相对表达量(0.42±0.06比0.58±0.07、0.80±0.10、0.95±0.11),N-cadherin蛋白相对表达量(0.15±0.03比0.25±0.04、0.74±0.07、0.95±0.11)、p-JNK水平(0.14±0.03比0.29±0.05、0.68±0.07、0.95±0.10)均升高(P均<0.001)。不同剂量和阴性对照组的JNK mRNA与蛋白表达差异均无统计学意义(P>0.05)。结论DCA可抑制人肾癌细胞株A498侵袭及迁移,且一定范围内呈剂量依赖性,推测与调控侵袭及迁移相关基因与蛋白表达有关。     

人肾细胞癌细胞阳离子脂质体的转染效率

以ＭＴＳ染色法测定实验剂量的Ｌｉｐｏｆｅｃｔｉｎ对细胞的毒性作用,以β－半乳糖苷酶基因为报告基因,通过Ｌｉｐｏｆｅｃｔｉｎ而转染,用Ｘ－ｇａｌ染色法,测定转染效率,结果表明实验剂量（１０μｇ／ｍｌ）的Ｌｉｐｏｆｅｃｔｉｎ对细胞生长无明显毒性。Ｌｉｐｏｆｅｃｔｉｎ对多数肾细胞癌细胞的转染是有效的,且转染效率随Ｌｉｐｏｆｅｃｔｉｎ 度的增高（２．５－１０μｇ／ｍｌ）而增高,说明Ｌｉｐｏｆｅｃｔｉｎ可安     

Erythropoietin production in long-term cultures of human renal carcinoma cells : The role of cell population density

The present studies report the maintenance of erythropoietin (Ep) production in long-term cultures of a human renal carcinoma from a patient with erythrocytosis. The renal carcinoma cells were grown and maintained in monolayer cultures for 7 months. They were serially passaged every 2-3 weeks when the cultured cells reached confluency. Ep levels measured with a sensitive radioimmunoassay in the spent culture media of the cells in the stage of semiconfluent or confluent density were less than 20 and 30 mU/ml, respectively, throughout the period of 15 successive passages. However, when the renal carcinoma cells were maintained in culture without passage after reaching confluency, Ep levels in the spent media of these cells reproducibly showed an exponential increase to more than 300 mU/ml at the time of saturation density. The importance of cell population density in Ep production by the renal carcinoma cell cultures was further confirmed by the observation that the cultures with higher seeding density reached confluency earlier and began an exponential increase in Ep production sooner than those cultures with lower seeding density.     

The role of calmodulin in human renal cell carcinoma

Calmodulin is a ubiquitous intracellular calcium binding protein which has been shown to be associated with cell cycling. Previous studies using animal tumor models have suggested a positive correlation between tumor calmodulin content and rate of tumor growth. We studied the role of calmodulin in renal cell carcinoma (RCC) cell lines and compared this with short term normal fetal kidney cell lines. The effects of calmodulin inhibition was determined using the calmodulin inhibitor W13 (Naphthalene-sulfonamide) and its less active partner W12. Cell size, calmodulin content and inhibition studies using W13 did not reveal any simple correlations for the RCC cell lines, although the RCC lines did have a higher content than the fetal kidney cell lines. Calmodulin content determination of RCC and normal adult kidney tissue failed to show any difference. We conclude that, contrary to previous reports using animal models, there is no simple relationship between tumor growth rates and calmodulin content for human RCC.     

Elevated cyclin E level in human clear cell renal cell carcinoma: possible causes and consequences

The expression of cyclin E gene (CCNE) in relation to the expression of its major regulatory protein, E2F1, was examined in clear cell renal cell carcinomas (ccRCC). We show that the overexpression of E2F1 is accompanied by the significant increase of the mean amounts of cyclin E mRNA, as well as of total cyclin E protein and its low molecular weight forms in cancer tissues as compared to peritumoral controls. A significant increase of the mean amount of total cyclin E was found in peritumoral tissues compared to cancer-free kidneys, suggesting that cancer cells might secrete factors having a profound influence on the metabolism of neighbouring tissues. A significant, positive correlations between E2F1 protein and total cyclin E mRNA, as well as between E2F1 protein and full length cyclin E protein were found in cancer-free kidneys and in peritumoral tissues, but not in ccRCCs. The overexpression of cyclin E positively correlated with the decreasing degree of tumor differentiation, implicating a role for cyclin E in the promotion of tumorigenesis.