Overexpressed targeting protein for Xklp2 (TPX2) serves as a promising prognostic marker and therapeutic target for gastric cancer

The targeting protein for Xenopus kinesin-like protein 2 (TPX2) is a putative oncogene in different human cancers. This study assessed TPX2 expression in gastric cancer tissue samples and then determined the effects of TPX2 knockdown on the regulation of gastric cancer cell malignant behaviors in vitro. Tissue samples from 115 gastric cancer patients were analyzed for TPX2 expression. The effects of TPX2 siRNA on gastric cancer cells were assessed in vitro, including cell viability, cell cycle distribution, apoptosis, migration, and invasion. The data showed that TPX2 was overexpressed in gastric cancer tissues compared to that in the adjacent normal epithelia. Moreover, TPX2 overexpression was associated with a poor overall survival and was an independent prognostic predictor of gastric cancer. In addition, the in vitro study further confirmed the ex vivo data, i.e., knockdown of TPX2 expression reduced gastric cancer cell viability but induced apoptosis and arrested cells at the G2/M phase of the cell cycle. Knockdown of TPX2 expression also inhibited the tumor cell migration and invasion capacity in vitro. At the gene level, knockdown of TPX2 expression upregulated the levels of cyclin B1, cdk4, p53, Bax, caspase-3, and E-cadherin, but downregulated the levels of cyclin D1, cdk2, N-cadherin, slug, matrix metalloprotease (MMP)-2, and MMP-9, suggesting that knockdown of TPX2 expression suppressed tumor cell epithelial–mesenchymal transition (EMT). This study demonstrated that detection of TPX2 overexpression could serve as a prognostic marker and therapeutic target for gastric cancer.     

TPX2基因表达对膀胱癌患者预后的影响

目的 通过基因表达汇编公共数据库,探讨 Xklp2 靶蛋白在膀胱癌中的表达情况,并进一步探索其与膀胱癌临床 病理特征的关系,评价TPX2 对膀胱癌术后患者预后评价的意义,预测TPX2 推动膀胱癌发生和发展机制。方法 从 NCBI 的基因表达汇编数据库收集膀胱肿瘤相关的公共数据集,对其中的表达谱资料及相关临床资料进行分析;基于GSEA3.0, 使用基因富集分析方法,分析TPX2 调控的基因通路。结果 TPX2 在膀胱癌组织中为高表达（P ＜ 0.0001）。不同年龄 （P=0.027）、性别（P=0.040）、T 分期（P=0.001）、N 分期（P=0.013）、进程（progression,P=0.002）和分级水 平（grade）中,TPX2 的表达存在明显差异。TPX2 的表达水平与膀胱癌患者预后总生存率和是否复发相关（P ＜ 0.05）; TPX2 表达水平高的样本富集了与精子发生、未折叠蛋白反应、PI3K/AKT/mTOR 通路、mtorc1 信号通路、胆固醇平衡、有丝分裂、糖酵解、G2M 检查点、E2F 转录因子、癌基因 myc 有关的基因集。结论 TPX2 在膀胱癌中为高表达,与膀胱癌多 个病理性指标相关,且可以作为潜在的判断膀胱癌患者预后的标志物和治疗肿瘤的靶标。     

Secreted frizzled-related protein 1 loss contributes to tumor phenotype of clear cell renal cell carcinoma.

PURPOSE: Incidence and mortality rates for renal cell carcinoma (RCC) have been rising for decades. Unfortunately, the molecular events that support RCC carcinogenesis remain poorly understood. In an effort to gain a better understanding of signaling events in clear cell RCC (cRCC), we investigated the antitumor activity of secreted frizzled-related protein 1 (sFRP1), a negative regulator of Wnt signaling. EXPERIMENTAL DESIGN: Genomic profiling of cRCC tumors and patient-matched normal tissues was done and confirmed using quantitative PCR and immunohistochemistry. Methylation-specific PCR was done on patient samples to evaluate the mechanism responsible for sFRP1 loss. sFRP1 expression was restored in cRCC cells and the effects on tumor phenotype were characterized. RESULTS: Genomic profiling, quantitative PCR, and immunohistochemistry indicated that loss of sFRP1 occurred in cRCC and papillary RCC patient tissues. Twelve Wnt-regulated genes were up-regulated in cRCC tissues, including c-myc and cyclin D1, potentiators of cell proliferation and survival. Methylation of the sFRP1 gene was one mechanism identified for attenuation of sFRP1 mRNA. Stable reexpression of sFRP1 in cRCC cells resulted in decreased expression of Wnt target genes, decreased growth in cell culture, inhibition of anchorage-independent growth, and decreased tumor growth in athymic nude mice. CONCLUSIONS: To our knowledge, this is the first report to show that stable restoration of sFRP1 expression in cRCC cells attenuates the cRCC tumor phenotype. Our data support a role for sFRP1 as a tumor suppressor in cRCC and that perhaps loss of sFRP1 is an early, aberrant molecular event in renal cell carcinogenesis.     

SOX10 is over-expressed in bladder cancer and contributes to the malignant bladder cancer cell behaviors

Purpose

To detect the expression level and significance of SOX10 in human bladder cancer.

Methods

Immunohistochemical analyses were performed to assess SOX10 protein level using a bladder cancer tissue microarray (including 59 spots of cancer tissues and 46 spots of paired normal tissues) and 31 specimens and to define the relationship between SOX10 and clinicopathological bladder cancer characteristics in patients. SOX10 protein and mRNA levels in bladder cancer cell lines (T24, 5637, BIU87, EJ) and transitional cell papilloma cell line (RT4) were tested by western blotting and quantitative real-time PCR (q-PCR), respectively. Cell Counting Kit-8 (CCK-8) and colony formation assays were performed to investigate bladder cancer cell proliferation after SOX10 knockdown. The effect of SOX10 on cell migration and invasion was analyzed by Transwell and Matrigel assays. Kaplan–Meier survival curves and Cox regression analyses were used to evaluate SOX10 prognostic significance for bladder cancer patients. The mechanisms by which SOX10 promote bladder cancer progression were examined by western blotting.

Results

SOX10 protein was upregulated in 74.4% of bladder cancer tissues compared with adjacent normal tissues (32.6%). SOX10 protein was also upregulated in malignant cell lines. In addition, high SOX10 expression was related with clinical stage (P = 0.008), T stage (P = 0.004), histological grade (P = 0.002) and lymph node metastasis (P = 0.006). Kaplan–Meier survival curves and Cox regression analyses showed that SOX10 functioned as an independent prognostic factor for overall survival. SOX10 knockdown in bladder cancer cells significantly impacted proliferation, migration and invasion, and SOX10 might promote bladder cancer progression by altering β-catenin and Met expression.

Conclusion

SOX10 was over-expressed in bladder cancer and promoted malignant bladder cancer cell behaviors. SOX10 has potential as a molecular target for bladder cancer treatment.

     

Overexpression of TRIM44 contributes to malignant outcome in gastric carcinoma

Recent studies have shown that some members of the tripartite motif‐containing protein (TRIM) family, which is characterized by a conserved RING finger, B‐box, and coiled‐coil domains, function as important regulators for carcinogenesis. In this study, we tested whether TRIM44 (11p13) acts as a cancer‐promoting gene through overexpression in gastric cancer. We analyzed seven gastric cancer cell lines and 112 primary tumors, which were curatively resected in our hospital between 2001 and 2003. Expression of the TRIM44 protein was detected in gastric cancer cell lines (2/7 cell lines; 29%) and primary tumor samples of gastric cancer (29/112 cases; 25%). Knockdown of TRIM44 expression using several specific siRNAs inhibited the proliferation, migration, and invasion of TRIM44‐overexpressing cells. Overexpression of the TRIM44 protein was significantly correlated with an advanced type of macroscopic appearance, lymphatic invasion, and higher recurrence rate. TRIM44‐overexpressing tumors had a worse overall rate of survival than those with non‐expressing tumors (P = 0.0038, log–rank test) in both intensity and proportion expression‐dependent manner. TRIM44 positivity was independently associated with worse outcome in multivariate analysis (P = 0.0233, hazard ratio 3.37 [1.18–9.64]). These findings suggest that TRIM44 plays a crucial role in tumor cell proliferation through its overexpression, and highlight its usefulness as a predictor and potential therapeutic target in gastric cancer.     

TPX2 as a Novel Prognostic Indicator and Promising Therapeutic Target in Triple-negative Breast Cancer

IntroductionTriple-negative breast cancer (TNBC), which lacks endocrine therapies and targeted therapies, has the worst prognosis of all breast cancers which remain the most common malignancy in women worldwide. Targeting protein for xenopus kinesin-like protein 2 (TPX2) is a microtubule-associated protein that is strongly correlated with chromosomal instability, resulting in the development of different human tumors. Herein, we investigated the relationship between the clinical outcome of TNBC and the expression level of the TPX2 protein.Materials and MethodsPatients initially treated at Tongji Hospital for confirmed TNBC were evaluated by immunohistochemical staining and retrospectively recruited into our study. The immunohistochemical staining evaluation of TPX2 was based on the staining intensity and extent. STATA was used to analyze all the data.ResultsIn total, 97 patients with TNBC were recruited into our study. The TPX2 protein was overexpressed in almost all patients with TNBC. Our study demonstrated that an elevated TPX2 protein level was significantly associated with worse outcomes in the patients with TNBC, including worse progression-free survival (PFS) and overall survival (OS) (log-rank test, P < .001). Our model also indicated that TPX2 expression was an independent predictor of OS (hazard ratio, 2.20; 95% confidence interval, 1.13-4.28; P = .020) but not of PFS (P = .639).ConclusionIn conclusion, we demonstrated that TPX2 could be a novel prognostic marker of PFS and OS after the initial treatment of TNBC. We also revealed that TPX2 expression could serve as an independent predictor of OS but not of PFS and a promising therapeutic target in patients with TNBC.     

CD44+/CD24- phenotype contributes to malignant relapse following surgical resection and chemotherapy in patients with invasive ductal carcinoma

Background

Invasive ductal carcinoma is the most common type of breast malignancy, with varying molecular features and resistance to treatment. Although CD44+/CD24- cells are believed to act as breast cancer stem cells and to be linked to poor prognosis in some patients, the association between these cells and tumor recurrence or metastasis in all or some types of invasive ductal carcinoma is unclear.

Methods

A total of 147 randomly selected primary and secondary invasive ductal carcinoma samples were assayed for expression of CD44, CD24, ER, PR, and Her2. The association between the proportions of CD44+/CD24- tumor cells and the clinico-pathological features of these patients was evaluated.

Results

CD44+/CD24- tumor cells were detected in 70.1% of the tumors, with a median proportion of 5.8%. The proportion of CD44+/CD24- tumor cells was significantly associated with lymph node involvement (P = 0.026) and PR status (P = 0.038), and was correlated with strong PR status in patients with recurrent or metastatic tumors (P = 0.046) and with basal-like features (p = 0.05). The median disease-free survival (DFS) of patients with and without CD44⁺/CD24^-/low tumor cells were 22.9 ± 2.2 months and 35.9 ± 3.8 months, and the median overall survival (OS) of patients with and without CD44⁺/CD24^-/low tumor cells were 39.3 ± 2.6 months and 54.0 ± 3.5 months, respectively, and with both univariate and multivariate analyses showing that the proportion of CD44⁺/CD24^-/low tumor cells was strongly correlated with DFS and OS.

Conclusion

The prevalence of CD44+/CD24- tumor cells varied greatly in invasive ductal carcinomas, with the occurrence of this phenotype high in primary tumors with high PR status and in secondary tumors. Moreover, this phenotype was significantly associated with shorter cumulative DFS and OS. Thus, the CD44⁺/CD24^- phenotype may be an important factor for malignant relapse following surgical resection and chemotherapy in patients with invasive ductal carcinoma.     

Overexpression of SMYD2 contributes to malignant outcome in gastric cancer

Background:

SET and MYND domain-containing protein 2 (SMYD2) is a lysine methyltransferase for histone H3, p53 and Rb and inhibits their transactivation activities. In this study, we tested whether SMYD2 (1q42) acts as a cancer-promoting factor by being overexpressed in gastric cancer.

Methods:

We analysed 7 gastric cancer cell lines and 147 primary tumor samples of gastric cancer, which were curatively resected in our hospital.

Results:

SET and MYND domain-containing protein 2 was detected in these cell lines (five out of seven cell lines; 71.4%) and primary tumor samples (fifty-six out of one hundred and forty-seven cases; 38.1%). Knockdown of SMYD2 using specific small interfering RNA inhibited proliferation, migration and invasion of SMYD2-overexpressing cells in a TP53 mutation-independent manner. Overexpression of SMYD2 protein correlated with larger tumor size, more aggressive lymphatic invasion, deeper tumor invasion and higher rates of lymph node metastasis and recurrence. Patients with SMYD2-overexpressing tumours had a worse overall rate of survival than those with non-expressing tumours (P=0.0073, log-rank test) in an intensity and proportion score-dependent manner. Moreover, multivariate analysis demonstrated that SMYD2 was independently associated with worse outcome (P=0.0021, hazard ratio 4.25 (1.69–10.7)).

Conclusions:

These findings suggest that SMYD2 has a crucial role in tumor cell proliferation by its overexpression and highlight its usefulness as a prognostic factor and potential therapeutic target in gastric cancer.     

BCL-2, TP53 and BAX protein expression in superficial urothelial bladder carcinoma

Whether TP53, BCL-2 and BAX expressions add independent prognostic information in patients with Ta/T1bladder urothelial carcinoma remains unclear. TP53 overexpression correlated with high tumor grade (p = 0.004), WHO grading categories (0.045), BAX expression (p = 0.043) and pathologic stage (p = 0.05). BCL-2 immunostaining was inverse associated with tumor grade (p = 0.008). Lack of BAX expression was related to reduced patient’s survival (p = 0.028). Mortality was higher in patients with BCL-2+/TP53+ (p = 0.023) or TP53+/BAX− (p = 0.027) phenotype. BAX and pathologic stage were independent predictors of progression-free and overall survival, respectively. Therefore, BAX expression might be relevant in patient’s prognosis.     

ALKBH2, a novel AlkB homologue,contributes to human bladder cancer progression by regulating MUC1 expression

The ALKBH family of proteins are highly expressed in various types of human cancer where they are involved in tumor growth and progression. However, multiple isoforms of ALKBH exist and the effect of individual isoforms on the development of urinary bladder cancer is unknown, particularly the molecular mechanisms involved in the progression from a noninvasive to invasive phenotype. We examined the role and function of ALKBH2 in human bladder cancer development in vitro and provide the first report that suppression of ALKBH2 in a human urothelial carcinoma cell line, KU7, reduces the expression of the transmembrane mucin protein, MUC1, and induces G1 cell cycle arrest. Moreover, reduction of ALKBH2 suppressed epithelial to mesenchymal transition (EMT) via increasing E‐cadherin and decreasing vimentin expression. Transfection of MUC1 siRNA inhibited cell proliferation and EMT to the same extent as ALKBH2 gene silencing in vitro. ALKBH2 knockdown significantly suppressed MUC1 expression and tumor volume of bladder cancers in vivo as assessed in an orthotopic mouse model using ALKBH2 shRNA transfected KU7 cells. Immunohistochemical examination showed high expression levels of ALKBH2 in human urothelial carcinoma samples, especially in high‐grade, superficially and deeply invasive carcinomas (pT(1) and >pT(2)), and in carcinoma in situ but not in normal urothelium. This study demonstrates that ALKBH2 is an upstream molecule of the oncoprotein, MUC1, and regulates cell cycle and EMT, resulting in progression of urothelial carcinomas.     

RasGRP3, a Ras activator, contributes to signaling and the tumorigenic phenotype in human melanoma

RasGRP3, an activator for H-Ras, R-Ras and Ras-associated protein-1/2, has emerged as an important mediator of signaling downstream from receptor coupled phosphoinositide turnover in B and T cells. Here, we report that RasGRP3 showed a high level of expression in multiple human melanoma cell lines as well as in a subset of human melanoma tissue samples. Suppression of endogenous RasGRP3 expression in these melanoma cell lines reduced Ras-GTP formation as well as c-Met expression and Akt phosphorylation downstream from hepatocyte growth factor (HGF) or epidermal growth factor (EGF) stimulation. RasGRP3 suppression also inhibited cell proliferation and reduced both colony formation in soft agar and xenograft tumor growth in immunodeficient mice, demonstrating the importance of RasGRP3 for the transformed phenotype of the melanoma cells. Reciprocally, overexpression of RasGRP3 in human primary melanocytes altered cellular morphology, markedly enhanced cell proliferation and rendered the cells tumorigenic in a mouse xenograft model. Suppression of RasGRP3 expression in these cells inhibited downstream RasGRP3 responses and suppressed cell growth, confirming the functional role of RasGRP3 in the altered behavior of these cells. The identification of the role of RasGRP3 in melanoma highlights its importance, as a Ras activator, in the phosphoinositide signaling pathway in human melanoma and provides a new potential therapeutic target.     

Clinical and biological significance of S-phase kinase-associated protein 2 (Skp2) gene expression in gastric carcinoma: modulation of malignant phenotype by Skp2 overexpression,possibly via p27 proteolysis

Reduced expression level of p27, a cyclin-dependent kinase inhibitor, is associated with high aggressiveness and poor prognosis of various malignant tumors, including gastric carcinoma. S-phase kinase-associated protein 2 (Skp2), a member of the F-box family of substrate-recognition subunits of Skp1-Cullin-F-box ubiquitin-protein ligase complexes, is necessary for p27 ubiquitination and degradation. In the present study, we examined the clinical and biological significance of Skp2 expression in human gastric carcinoma and the relationship between the expression of Skp2 and p27. Northern blot analysis showed that Skp2 mRNA was overexpressed in carcinoma tissues (P < 0.05), and the high Skp2 expression group showed significantly poorer prognosis in 98 patients with gastric carcinoma (P < 0.05). Immunohistochemical analysis showed that Skp2 protein was expressed predominantly in carcinoma cells. We also found an inverse correlation between the expression of Skp2 mRNA and p27 protein in vivo (P < 0.01). To analyze the biological behavior of Skp2, we established stably Skp2-transfected gastric carcinoma cell lines. Western blot analysis showed that Skp2-transfected cells expressed lower levels of p27 protein than the control cells. Skp2-transfected cells showed significantly higher levels of growth rate (P < 0.05), percentage of bromodeoxyuridine-positive cells after serum starvation (P < 0.01), resistance to apoptosis induction by actinomycin D treatment (P < 0.05), and invasion potential (P < 0.01) than the control cells. These findings indicate that Skp2 expression can modulate the malignant phenotype of gastric carcinoma, possibly via p27 proteolysis. Skp2 can play an important role in gastric carcinoma progression and would be a novel target for the treatment of gastric carcinoma as well as a strong prognostic marker.