Up-regulation of MKK4, MKK6 and MKK7 during prostate cancer progression: an important role for SAPK signalling in prostatic neoplasia

Identification of the signalling cascades that are differentially activated during prostatic tumourigenesis is a crucial step in the search for future molecular targets in this disease. The stress-activated protein kinase (SAPK) signalling cascade culminates in the phosphorylation of the JNK and p38 mitogen-activated protein kinases (MAPKs). Recently, the upstream activators of these proteins, the MAPK kinases (MKKs), have been implicated as inhibitors of tumour progression in a variety of clinical and experimental tumour models. This study evaluates MKK4, MKK6 and MKK7 expression during prostate cancer progression in humans and in the transgenic adenocarcinoma of a mouse prostate (TRAMP) model of prostate tumourigenesis. Benign prostate, prostatic intraepithelial neoplasia (PIN) lesions and tumour tissues were collected from 37 TRAMP mice. Additionally, six tissue microarrays were constructed with tumours from a matched group of 102 men who underwent radical prostatectomy. Tissues from 20 patients with extensive high-grade prostatic intraepithelial neoplasia (HGPIN) were also analysed. For all samples, immunohistochemical staining for MKK4, MKK6 and MKK7 was scored in normal and neoplastic glands. Staining intensities of MKK4, MKK6 and MKK7 were significantly increased in HGPIN and prostate cancer compared to surrounding normal glands in both the TRAMP and human samples (p < 0.0001 for all markers). Increased levels of MKK4 or MKK7 correlated with higher pathological stage at prostatectomy (p = 0.01 and p = 0.04). Using multivariate analysis, there was no association between protein levels and time to biochemical recurrence in the human samples. The up-regulation of MKK4, MKK6 and MKK7 during prostate cancer progression in both TRAMP and human tissues highlights an important role for the SAPK signalling cascade in prostatic neoplasia. The finding that higher MKK4 and MKK7 expression is associated with higher-stage prostatic tumours underscores the dynamic regulation of these proteins during prostatic tumourigenesis.     

Ack1 tyrosine kinase activation correlates with pancreatic cancer progression

Pancreatic cancer is a significant cause of cancer mortality worldwide as the disease has advanced significantly in patients before symptoms are evident. The signal transduction pathways that promote this rapid progression are not well understood. Ack1 or TNK2, an ubiquitously expressed oncogenic non-receptor tyrosine kinase, integrates signals from ligand-activated receptor tyrosine kinases to modulate intracellular signaling cascades. In the present study, we investigated the Ack1 activation profile in a pancreatic cancer tumor microarray, and observed that expression levels of activated Ack1 and pTyr284-Ack1 positively correlated with the severity of disease progression and inversely correlated with the survival of patients with pancreatic cancer. To explore the mechanisms by which Ack1 promotes tumor progression, we investigated the role of AKT/PKB, an oncogene and Ack1-interacting protein. Ack1 activates AKT directly in pancreatic and other cancer cell lines by phosphorylating AKT at Tyr176 to promote cell survival. In addition, the Ack1 inhibitor AIM-100 not only inhibited Ack1 activation but also suppressed AKT tyrosine phosphorylation, leading to cell cycle arrest in the G1 phase. This effect resulted in a significant decrease in the proliferation of pancreatic cancer cells and induction of apoptosis. Collectively, our data indicate that activated Ack1 could be a prognostic marker for ascertaining early or advanced pancreatic cancer. Thus, Ack1 inhibitors hold promise for therapeutic intervention to inhibit pancreatic tumor growth.     

Mechanism of p38 MAP kinase activation in vivo

The p38 mitogen-activated protein kinase (MAPK) is activated in vitro by three different protein kinases: MKK3, MKK4, and MKK6. To examine the relative roles of these protein kinases in the mechanism of p38 MAP kinase activation in vivo, we examined the effect of disruption of the murine Mkk3, Mkk4, and Mkk6 genes on the p38 MAPK signaling pathway. We show that MKK3 and MKK6are essential for tumor necrosis factor-stimulated p38 MAPK activation. In contrast, ultraviolet radiation-stimulated p38 MAPK activation was mediated by MKK3, MKK4, and MKK6. Loss of p38 MAPK activation in the mutant cells was associated with defects in growth arrest and increased tumorigenesis. These data indicate that p38 MAPK is regulated by the coordinated and selective actions of three different protein kinases in response to cytokines and exposure to environmental stress.     

High expression of integrin-linked kinase predicts aggressiveness and poor prognosis in patients with gastric cancer

Integrin-linked kinase (ILK), an intracellular serine/threonine protein kinase, has been reported to be highly expressed in many human malignancies, including gastric cancer. However, the prognostic significance of ILK expression in gastric cancer remains to be elucidated. In the present study, ILK expression in 95 gastric tumor tissues and 30 adjacent non-cancerous gastric mucosa was evaluated by immunohistochemistry and correlated with clinicopathological characteristics and patients’ outcome. The results showed that high ILK expression was observed in 47.4% (45/95) of gastric cancer tissues, but only in 20.0% (6/30) of adjacent gastric mucosa. Clinicopathological analysis indicated that high ILK expression was significantly associated with poor tumor differentiation (P = 0.024), advanced TNM stage (P = 0.006), tumor invasion (P = 0.001), and lymph node metastasis (P = 0.014). Kaplan–Meier survival curves demonstrated that patients with high ILK expression had substantially shorter overall survival that those with low ILK expression (P = 0.043, log-rank test). Furthermore, Cox multivariate regression analysis identified ILK expression as an independent prognostic factor for overall survival of gastric cancer patients (hazard ratio, 1.95; 95% confidence interval, 1.02–3.13; P = 0.026). In conclusion, our data suggest that ILK may contribute to the malignant progression of gastric cancer and serve as a novel prognostic indicator for gastric cancer patients.     

丝裂原活化蛋白激酶激酶1在胃癌中的表达及其临床意义

目的 探讨丝裂原活化蛋白激酶激酶1（MAP2K1）在胃癌中的表达及其临床意义。 方法 免疫组织化学及Western blotting检测MAP2K1在胃癌组织和细胞中蛋白水平的表达;免疫荧光染色观察细胞形态及MAP2K1的表达位置;StarBase及Oncomine 数据库对MAP2K1进行数据挖掘,分析MAP2K1 mRNA在胃癌组织中的表达情况;UALCAN数据库分析MAP2K1 mRNA的表达与临床病理特征的相关性;Kaplan Meier-Plotter 在线分析工具进行生存分析; GEPIA2数据库挖掘MAP2K1与胃癌干细胞相关因子和耐药相关因子的关系。 结果 免疫组织化学、免疫荧光和Western blotting结果表明,在胃癌组织和细胞中MAP2K1蛋白为高表达,且MAP2K1表达在胃癌细胞质中。由多种数据库分析得出,MAP2K1 mRNA在胃癌组织的表达量高于正常胃组织,其表达量与胃癌分期、分级、淋巴结转移和患者性别密切相关,MAP2K1高表达组的胃癌患者总体生存率明显低于低表达组,其原因可能与胃癌干细胞特性和耐药性相关。 结论 MAP2K1在胃癌中高表达,其表达水平可能通过调控干细胞相关因子与耐药相关因子影响患者不良预后。MAP2K1或可成为判断胃癌患者预后的新型诊断标志物。     

A novel isoform of the B cell tyrosine kinase BTK protects breast cancer cells from apoptosis

Tyrosine kinases orchestrate key cellular signaling pathways and their dysregulation is often associated with cellular transformation. Several recent cases in which inhibitors of tyrosine kinases have been successfully used as anticancer agents have underscored the importance of this class of proteins in the development of targeted cancer therapies. We have carried out a large‐scale loss‐of‐function analysis of the human tyrosine kinases using RNA interference to identify novel survival factors for breast cancer cells. In addition to kinases with known roles in breast and other cancers, we identified several kinases that were previously unknown to be required for breast cancer cell survival. The most surprising of these was the cytosolic, nonreceptor tyrosine kinase, Bruton's tyrosine kinase (BTK), which has been extensively studied in B cell development. Down regulation of this protein with RNAi or inhibition with pharmacological inhibitors causes apoptosis; overexpression inhibits apoptosis induced by Doxorubicin in breast cancer cells. Our results surprisingly show that BTK is expressed in several breast cancer cell lines and tumors. The predominant form of BTK found in tumor cells is transcribed from an alternative promoter and results in a protein with an amino‐terminal extension. This alternate form of BTK is expressed at significantly higher levels in tumorigenic breast cells than in normal breast cells. Since this protein is a survival factor for these cells, it represents both a potential marker and novel therapeutic target for breast cancer. © 2013 Wiley Periodicals, Inc.     

Phosphorylation profiles of protein kinases in alveolar and embryonal rhabdomyosarcoma.

Rhabdomyosarcoma is the most common pediatric soft-tissue sarcoma, which includes two major subtypes, alveolar and embryonal rhabdomyosarcoma. The mechanism of its oncogenesis is largely unknown. However, the oncogenic process of rhabdomyosarcoma involves multi-stages of signaling protein dysregulation characterized by prolonged activation of tyrosine and serine/threonine kinases. To better understand this protein dysregulation, we evaluated the phosphorylation profiles of multiple tyrosine and serine/threonine kinases to identify whether these protein kinases are activated in rhabdomyosarcoma. We applied immunohistochemistry with phospho-specific antibodies to examine phosphorylation levels of selected receptor and non-receptor tyrosine kinases, mammalian target of rapamycin (mTOR), p70S6K, and protein kinase C (PKC) isozymes on alveolar and embryonal rhabdomyosarcoma tissue microarray slides. Our results showed that the phosphorylation levels of these kinases are elevated in some rhabdomyosarcoma tissues compared to normal tissues. Phosphorylation levels of receptor and non-receptor tyrosine kinases are elevated between 26 and 68% in alveolar rhabdomyosarcoma and between 24 and 71% in embryonal rhabdomyosarcoma, respectively, compared to normal tissues. In addition, phosphorylation levels of mTOR and its downstream targets, p70S6K, S6, and 4EBP1, are increased between 50 and 72% in both subtypes of rhabdomyosarcoma. Further, phosphorylation levels of PKCalpha, PKCdelta, PKCtheta, and PKCzeta/lambda are upregulated between 57 and 69% in alveolar rhabdomyosarcoma and between 43 and 72% in embryonal rhabdomyosarcoma. This is the first report to create a phosphorylation profile of tyrosine and serine/threonine kinases involved in the mTOR and PKC pathways of alveolar and embryonal rhabdomyosarcoma. These protein kinases may play roles in the development or tumor progression of rhabdomyosarcomas and thus may serve as novel targets for therapeutic intervention.     

Guanine nucleotide binding protein-like 3 is a potential prognosis indicator of gastric cancer

Guanine nucleotide binding protein-like 3 (GNL3) is a GIP-binding nuclear protein that has been reported to be involved in various biological processes, including cell proliferation, cellular senescence and tumorigenesis. This study aimed to investigate the expression level of GNL3 in gastric cancer and to evaluate the relationship between its expression and clinical variables and overall survival of gastric cancer patients. The expression level of GNL3 was examined in 89 human gastric cancer samples using immunohistochemistry (IHC) staining. GNL3 in gastric cancer tissues was significantly upregulated compared with paracancerous tissues. GNL3 expression in adjacent non-cancerous tissues was associated with sex and tumor size. Survival analyses showed that GNL3 expression in both gastric cancer and adjacent non-cancerous tissues were not related to overall survival. However, in the subgroup of patients with larger tumor size (≥ 6 cm), a close association was found between GNL3 expression in gastric cancer tissues and overall survival. GNL3-positive patients had a shorter survival than GNL3-negative patients. Our study suggests that GNL3 might play an important role in the progression of gastric cancer and serve as a biomarker for poor prognosis in gastric cancer patients.     

Expression of Tie-1 and 2 receptors, and angiopoietin-1, 2 and 4 in gastric carcinoma; immunohistochemical analyses and correlation with clinicopathological factors

AIMS: There is strong evidence that tyrosine kinases are involved in the regulation of tumour progression, cellular growth and differentiation. Recently, many kinds of tyrosine kinase receptors have been reported, and among them Tie-1 and 2 constitute a major class. Angiopoietin (Ang)-1 is known as a ligand of the Tie-2 tyrosine kinase receptor. The aim of this study was to determine the expression profile of Tie-1 and 2 and Ang-1, 2 and 4 in gastric adenocarcinoma. METHODS AND RESULTS: Eighty-nine cases of surgically resected human gastric adenocarcinoma were studied by immunohistochemistry. Of these, 60 (67.4%), 61 (68.5%), 69 (77.5%), 75 (84.3%), and 47 cases (52.8%) showed positive staining in the cytoplasm of carcinoma cells for the Tie-1 and 2 and Ang-1, 2 and 4 proteins, respectively. The expression of Ties and Angs was significantly correlated with several type of histological differentiation and several clinicopathological factors. CONCLUSIONS: Ties and Angs were highly expressed in human gastric adenocarcinoma cells. These findings suggest that the Tie-Ang receptor-ligand complex is one of the factors involved in the cellular differentiation and progression of human gastric adenocarcinoma.     

Biological role of anaplastic lymphoma kinase in neuroblastoma

Anaplastic lymphoma kinase (ALK) is a tyrosine kinase receptor originally identified as part of the chimeric nucleophosmin-ALK protein in the t(2;5) chromosomal rearrangement associated with anaplastic large cell lymphoma. We recently demonstrated that the ALK kinase is constitutively activated by gene amplification at the ALK locus in several neuroblastoma cell lines. Forming a stable complex with hyperphosphorylated ShcC, activated ALK modifies the responsiveness of the mitogen-activated protein kinase pathway to growth factors. In the present study, the biological role of activated ALK was examined by suppressing the expression of ALK kinase in neuroblastoma cell lines using an RNA interference technique. The suppression of activated ALK in neuroblastoma cells by RNA interference significantly reduced the phosphorylation of ShcC, mitogen-activated protein kinases, and Akt, inducing rapid apoptosis in the cells. By immunohistochemical analysis, the cytoplasmic expression of ALK was detected in most of the samples of neuroblastoma tissues regardless of the stage of the tumor, whereas significant amplification of ALK was observed in only 1 of 85 cases of human neuroblastoma samples. These data demonstrate the limited frequency of ALK activation in the real progression of neuroblastoma.     

Elevated epiregulin expression predicts poor prognosis in gastric cancer

Epiregulin (EREG) is a novel family member of EGF-like ligands and have elevated expression in a variety of human cancers. EREG expression promotes tumor progression and metastasis and reduces patient survival. However, the expression of EREG and its prognostic value are not clear in gastric cancer (GC). We assessed EREG mRNA and protein expression in GC tissues from Chinese patients using quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical staining of tissue microarray, and analyzed the correlation between the level of EREG expression and patient clinical characteristics and prognosis. We found that EREG expression was significantly higher in GC tissues than in matched adjacent noncancerous tissues. High EREG protein expression in GC was significantly associated with TNM stage including tumor size, lymph node metastases and distant metastases as well as poor overall survival. These finding demonstrate that EREG is an independent prognostic biomarker for GC.     

Analysis of a cytoskeleton-associated kinase PEAK1 and E-cadherin in gastric cancer

The expression of pseudopodium-enriched atypical kinase 1(PEAK1) has been studied in human cancers. However, their roles in gastric cancer are still unknown. In this study, gastric cancer tissue microarrays were constructed with 159 gastric cancer tissue samples, 150 non-neoplastic gastric epithelium specimens and 152 lymph node samples. Immunohistochemical staining for PEAK1 and E-cadherin was performed. Our study found negative expression of PEAK1 in 113 of 159 (71.1%) gastric cancers, in 46 of 150 (30.7%) non-neoplastic gastric epithelium tissues and in 69 of 94 (73.4%) metastatic lymph nodes. Negative expression of PEAK1 and E-cadherin associated with tumor grading, depth of invasion, lymph node metastases, pTNM stage and macroscopic type. Patients with either positive PEAK1 or E-cadherin expression had a significantly higher survival than those with negative expression. When combined, PEAK1⁻/E-cadherin⁻ had a significantly poor prognosis than the rest of the patients. The expression of PEAK1 protein was positively correlated with E-cadherin in cancer tissues. Cox regression analyses showed that PEAK1, E-cadherin and PEAK1⁻/E-cadherin⁻ were independent predictors of overall survival. In conclusion, our findings suggest that loss of PEAK1 may play an important role in carcinogenesis and development of gastric cancer through activating epithelial to mesenchymal transition.     

鸢尾素抑制JAK/STAT3通路促进炎症状态下的血管生成

目的　研究急性炎症状态下鸢尾素对人脐静脉内皮细胞（human umbilical vein endothelial cell,HUVEC）血管生成的影响及其机制。 方法　通过CCK-8检测不同浓度（0.1、1.0、5.0、10.0、20.0 ng/mL）的鸢尾素对HUVEC增殖的影响;用脂多糖诱导HUVEC急性炎症状态,通过划痕和成管实验,研究鸢尾素对细胞迁移及管样形成的影响,通过RT-PCR研究相关细胞因子IL-1β、IL-6、TNF-α、PDGF-BB的基因表达;Western blot检测JAK／STAT3信号通路中关键蛋白Erk1／2、Jak、Stat3的表达。 结果　各浓度的重组鸢尾素均不影响HUVEC的增殖;在急性炎症状态下,鸢尾素可以促进HUVEC细胞迁移和管样形成,并且抑制HUVEC炎症因子IL-1β、IL-6、TNF-α基因的表达,增加组织修复相关因子PDGF-BB的基因表达;鸢尾素抑制LPS诱导的JAK／STAT3通路激活。 结论　鸢尾素可以抑制JAK／STAT3信号通路,缓解LPS诱导的HUVEC急性炎症状态,促进血管新生。     

蛋白激酶WEE1在胃癌组织中的表达及其临床意义

目的　探讨蛋白激酶WEE1在胃癌组织中的表达及其与胃癌临床指标的相关性,并阐述其在胃癌发生发展中的作用。 方法　使用Oncomine数据库分析WEE1在胃腺癌和胃黏膜组织中的表达差异。选取100例胃腺癌和80例癌旁组织标本,通过免疫组织化学法和组织芯片技术检测WEE1蛋白在胃癌和癌旁组织中的表达水平。对免疫组织化学结果中染色的比例以及染色程度进行半定量分析,对半定量分析结果与胃癌临床指标进行相关性分析。使用RT-PCR和Western blotting检测WEE1在胃癌和癌旁组织中的mRNA和蛋白表达水平。 结果　WEE1在100例胃癌患者中的阳性率为86%,高表达86例,低表达14例。通过Oncomine数据库分析,蛋白激酶WEE1在胃腺癌中的表达明显高于胃黏膜组织中的表达（P<0.01）。免疫组化、RT-PCR和Western blotting均显示,WEE1在胃癌组织中的表达明显高于癌旁组织（P<0.01）;免疫组化还显示WEE1的表达量随着胃癌组织分期的增加而增加（P<0.01）。 结论　蛋白激酶WEE1在胃癌组织中高表达,提示其可作为胃癌治疗靶点之一。     

Protein signatures for classification and prognosis of gastric cancer a signaling pathway-based approach

Current methods have limited accuracy in predicting survival and stratifying patients with gastric cancer for appropriate treatment. We sought to identify protein signatures of gastric cancer for classification and prognostication. The Protein Pathway Array (initial study) and Western blot (confirmation) were used to assess the protein expression in a total of 199 fresh frozen gastric samples. There were 56 paired samples divided into a training set (n = 37) and a validation set (n = 19) for the identification of differentially expressed proteins between tumor and normal tissues. There were 56 tumor samples used to identify proteins correlating with tumor and nodal staging. All 93 tumor samples were used to identify candidate proteins for predicting survival. We confirmed the survival prediction of the candidate proteins by using an additional cohort of gastric cancer samples (n = 50). There were 22 proteins differentially expressed between normal and tumor tissues. Nine proteins were selected to build the predictor to classify normal and tumor samples. Ten proteins were differentially expressed among different T stages and four of these were associated with invasive behavior. An additional four proteins were associated with lymph node metastasis. Two proteins were identified as independent risk factors for overall survival. This study indicated that some dysregulated signaling proteins could be selected as useful biomarkers for tumor classification and predicting outcome in gastric cancer patients.