Overexpression of GLUT1 in colorectal cancer is independently associated with poor prognosis

Background: To investigate the expression of glucose transporter 1 (GLUT1) in colorectal cancer (CRC) and its relationship to clinicopathological variables. Methods: The expression of GLUT1 in 163 primary tumors together with the corresponding normal mucosa, and 36 liver metastases was examined using real-time PCR. Results: The mean value of GLUT1 was higher in primary tumors (50.390 ± 68.648) than in the corresponding normal mucosa (20.437 ± 28.703, p<0.0001), while there was no significant difference in GLUT1 expression between CRC and liver metastasis (50.390 ± 68.648 vs 52.277 ± 52.482, p=0.190). In CRCs, GLUT1 expression was higher in poorly differentiated than in well and moderately differentiated tumors (p=0.022), and higher in stage III + IV than in stage I + II tumors (p=0.035). The patients with high-expressed GLUT1 had a worse prognosis than those with low-expressed GLUT1 independently of gender, age, tumor site, stage and differentiation (p=0.026, RR 2.737, 95% CI 1.126-6.651) in stage I-III CRCs. In liver metastasis, GLUT1 expression was higher in larger tumors than in smaller ones (p=0.025). Conclusions: Overexpression of GLUT1 in stage I-III CRCs was independently associated with poor prognosis.     

Overexpression of integrin-linked kinase (ILK) is associated with tumor progression and an unfavorable prognosis in patients with colorectal cancer

Integrin-linked kinase (ILK), an intracellular serine-threonine kinase, has been reported to be overexpressed in multiple types of human malignancies, including colorectal cancer (CRC). The prognostic value of ILK in CRC, however, remains unknown. In the present study, expression of ILK in 25 paired primary CRC samples and adjacent noncancerous tissues were quantified using real-time PCR and Western blotting. ILK protein expression was analyzed in 102 archived, paraffin-embedded CRC samples using immunohistochemistry. The correlation between ILK expression and clinicopathological factors was evaluated by the χ² test. Patients’ overall survival was analyzed by Kaplan–Meier method. We found that both ILK mRNA and protein expression levels were significantly up-regulated in primary CRC samples compared with their corresponding normal tissues. Immunohistochemical analysis revealed relative high expression of ILK in 43 of 102 (42.2 %) primary CRC samples. Statistical analysis showed a significant correlation of ILK expression with tumor differentiation, lymph node metastasis, tumor invasion, and tumor-node-metastasis stage. Patients with tumors displaying high-level ILK expression showed significantly shorter overall survival (P = 0.028, log-rank test). More importantly, multivariate analysis indicated that high ILK protein expression was an independent prognostic factor for CRC patients (P = 0.026). Taken together, our data suggest that ILK overexpression is associated with tumor progression and a poor prognosis in CRC patients and may represent a novel potential prognostic marker for patients with CRC.     

A Rho GDP-dissociation inhibitor is involved in cytokinesis of Dictyostelium

Myotubularin-related genes define a novel highly conserved family of eukaryotic proteins of at least 11 human members. The hMTM1 gene that codes for myotubularin is mutated in X-linked myotubular myopathy, a severe congenital disease. Recently, we and others have characterized myotubularin as a potent and specific phosphatidylinositol 3-phosphate 3-phosphatase. In the present study we investigated the lipid phosphatase activity and the subcellular localization of two other members of the family, hMTMR2 protein that is mutated in the demyelinating neuropathy Charcot-Marie-Tooth type 4B and the FYVE-finger containing hMTMR3 protein. Our results show that both proteins are potent phosphatidylinositol 3-phosphate 3-phosphatases either in vitro or in yeast where they interfered with vesicular trafficking. Their localization is mainly cytoplasmic, with however strong labeling of Rac-inducible plasma membrane ruffles. The fact that the ubiquitously expressed hMTM1 and hMTMR2 genes are involved in different pathologies indicates that despite their shared enzymatic activity, they are not functionally redundant, at least in certain cell types. This might be explained by subtle differences in expression and/or in recruitment and regulation at their specific site of action.     

Overexpression of PTP1B in human colorectal cancer and its association with tumor progression and prognosis

Protein tyrosine phosphatase 1B (PTP1B) is a non-transmembrane protein tyrosine phosphatase that has been implicated in cancer pathogenesis. However, the expression level and the role of PTP1B in the development and prognosis of colorectal cancer (CRC) remain unclear. In this study, the expression of PTP1B in CRC tissues and matched noncancerous tissues were detected by using immunohistochemistry, real-time PCR and Western blotting. The correlations between PTP1B expression level and clinicopathologic characteristics and patient survival were analyzed. We found that PTP1B expression was significantly higher in CRC tissues compared with matched non-tumour tissues. Statistical analysis showed that the PTP1B expression was correlated with tumor differentiation, tumor invasion, lymph node metastasis, and TNM stage. Patients with higher expressions of PTP1B had the lower survival (P = 0.012). Taken together, our results suggest that PTP1B expression might play a critical role in the progression of CRC and may serve as a valuable prognostic biomarker for CRC.     

High expression of Rab3D predicts poor prognosis and associates with tumor progression in colorectal cancer

Rab3D belongs to Rab protein family. Previous reports showed that the expression of Rab3D was dysregulated in various types of cancer. Rab3D belongsRab3D belongs. However, little is known about the role of Rab3D in carcinogenesis and progression of colorectal cancer (CRC). Here, we first evaluated the expression of Rab3D in 32 fresh CRC and matched normal tissues and found Rab3D was dramatically increased in CRC tissues compared to normal tissues (p < 0.001). Furthermore, immunochemistry was used to investigate Rab3D expression in 300CRC tissue specimens. The expression of Rab3D significantly positively correlated with the tumor size (p = 0.041), CEA level (p = 0.007), tumor classification (p = 0.030), lymphatic metastasis (p < 0.001), distant metastasis (p = 0.013) and clinical stage (p = 0.003). We also demonstrated that overall survival is poor in CRC patients with high expression of Rab3D (p < 0.001). Finally, we showed that Rab3D activated Akt/GSK3β/Snail pathway and induced EMT process in colorectal cancer cells. In conclusion, this study establishes increased Rab3D expression is associated with invasiveness of CRC cells, and Rab3D expression status may serve as a reliable prognostic biomarker in CRC patients.     

Downregulation of exosome-encapsulated miR-548c-5p is associated with poor prognosis in colorectal cancer

The role of circulating exosomal microRNAs (miRNAs) in colorectal cancer (CRC) has drawn more and more attention during the past few years. Previously, we have identified several specific miRNAs in serum exosomes as potential CRC biomarkers. However, little is known about the association between exosome-encapsulated miR-548c-5p and outcomes of patients with CRC. In the current study, the expression of serum exosomal miR-548c-5p was investigated by quantitative real-time polymerase chain reaction. Its correlation with CRC prognosis was estimated by Kaplan-Meier survival and log-rank tests. Cox regression analysis based on uni- and multivariate analyses was performed to estimate the relationship of exosome-encapsulated miR-548c-5p with the clinicopathological factors of patients with CRC. Reduced levels of serum exosomal miR-548c-5p were more significant in CRC patients with liver metastasis and at later TNM stage (III/IV tumor stages). Serum exosomal miR-548c-5p could inhibit the proliferation of CRC cells, while the precise molecular mechanisms warranted further elucidation. In addition, decreased levels of serum exosomal miR-548c-5p were independently associated with shorter overall survival in CRC adjusted by age, sex, tumor grade vascular infiltration, TNM stage (III/IV tumor stages) and metastasis (hazard ratio = 3.40, 95% confidence interval 1.02-11.27; P = 0.046). The downregulation of exosomal miR-548c-5p in serum predicts poor prognosis in patients with CRC. Exosomal miR-548c-5p may be a critical biomarker for CRC diagnosis and prognosis.     

Overexpression of CDKN2B is involved in poor gastric cancer prognosis

The objective of this investigation is to elucidate the clinical significance of cyclin-dependent kinase inhibitor 2B (CDKN2B) expression regarding gastric cancer (GC), as well as to detect the involvement of CDKN2B expression in the clinicopathological indexes and prognosis of GC. Immunohistochemical analysis was used for identification of CDKN2B expression in GC specimens. Chi-square (χ²) test was applied to detect the association of CDKN2B expression and clinicopathological parameters of GC. The involvement of CDKN2B expression in the prognosis was analyzed via univariate and multivariate analysis. It was indicated that relative to the corresponding para-carcinoma tissues, CDKN2B expression was notably upregulated in GC specimens. Moreover, the expression of CDKN2B was strongly correlated with the differentiation (r = −0.182; P = .015), invasion (r = −0.157; P = .038), distant metastases (r = −0.196; P = .004), and TNM stage (r = −0.204; P = .005). Nevertheless, no remarkable variance was related to age, tumor loci, or sex. Kaplan-Meier survival curve and univariate analysis showed that CDKN2B overexpression predicted poorer disease-free survival (P = .007) and overall survival (P = .005) in those with GC. In addition, Cox proportional hazards regression model revealed that CDKN2B was an isolated biomarker of disease-free survival and overall survival in patients with GC. Taken together, our data demonstrated that the overexpression of CDKN2B could be an isolated factor for GC prognostic in patients. CDKN2B gene may be a useful target and new treatment for improving the prognosis of GC.     

Syndecan-1 expression in human glioma is correlated with advanced tumor progression and poor prognosis

Syndecan-1 has been implicated in tumorigenesis and progression of various human malignancies. Recent studies have demonstrated that syndecan-1 may have a different function and biological activity depending on the specific tumor type. Therefore, the aim of this study was to investigate the clinical significance of syndecan-1 in human gliomas. One hundred and sixteen glioma patients (26 World Health Organization (WHO) grade I, 30 WHO grade II, 30 WHO grade III, and 30 WHO grade IV) and 15 normal brain specimens acquired from 15 patients undergoing surgery for epilepsy as control were collected. Immunohistochemistry assay, quantitative real-time PCR and Western blot analysis were carried out to detect the expression of syndecan-1 at gene and protein levels in glioma samples with different WHO grades. Syndecan-1 gene and protein levels were both higher in glioma tissues compared to controls (both P < 0.001). In addition, its expression levels increased with ascending tumor WHO grades according to the results of immunohistochemistry assay, quantitative real-time PCR and Western blot analysis. Moreover, the survival rate of syndecan-1-positive patients was significantly lower than that of syndecan-1-negative patients (P = 0.006). We further confirmed that the increased expression of syndecan-1 was an independent prognostic indicator in glioma by multivariate analysis (P = 0.01). Our data suggest for the first time that the increased expression of syndecan-1 at gene and protein levels is correlated with advanced tumor progression and poor outcome in patients with glioma. Syndecan-1 might serve as a potential prognosis predictor of this dismal tumor.     

Molecular characterization of the Caenorhabditis elegans Rho GDP-dissociation inhibitor.

GDP-dissociation inhibitors (GDIs) form one of the classes of regulatory proteins that modulate the cycling of the Ras superfamily of GTPases between active GTP-bound and inactive GDP-bound states. We report here the characterization of the Caenorhabditis elegans RhoGDI (CeRhoGDI) as part of our investigations into Rho-GTPase signalling pathways that are involved in nematode development. CeRhoGDI is a 23-kDa protein that is localized predominantly in the cytosol. CeRhoGDI interacts only with the lipid-modified forms of C. elegans Rho-GTPases, CeRhoA, CeRac1 and Cdc42Ce, in vitro and is able to solubilize the membrane-bound forms of these GTPases. CeRhoGDI recognizes the GTPases in both GTP- and GDP-bound forms; hence it inhibits both the guanine-nucleotide dissociation and GTP-hydrolysis activities. The inhibitory activity towards the GTP-bound GTPases is weak compared with that towards GDP-bound GTPases. CeRhoGDI is expressed throughout development and is highly expressed in marginal and vulval epithelial cells, in sperm cells and spicules. Taken together, our results suggest that CeRhoGDI may be involved in specific morphogenetic events mediated by the C. elegans Rho-GTPases.     

Characteristics of fatty acid distribution is associated with colorectal cancer prognosis

To investigate tissue fatty acid distribution in relation to the incidence of colorectal cancer prognosis, adjacent normal tissue and cancerous tissue from 35 samples of clinically incident colorectal cancer were obtained. Fatty acids were measured in the colorectal mucosa phospholipid fraction by gas chromatography mass spectrometry. Palmitoleic acid and oleic acid were significantly lower in colorectal cancerous tissue, ranging from 20% to 50% less than the adjacent normal tissue. The omega-6 (n-6) fatty acid family members (20:2, 20:3, 20:4 and 22:4) were higher by 1–3 fold in cancerous colorectal tissue. Contrary with the high level of n-6 fatty acids, about a 37% to 87% reduction in EPA and DHA was observed in colorectal cancerous tissue. A higher level of linoleic acid and arachidonic acid was detected in the C cancer stage than in the B cancer stage (p<0.05), but a lower level of oleic acid and docosahexenoic acid was detected in the C cancer stage (p<0.05). The fatty acid distribution of colorectal tissue is strongly linked to the incidence of colorectal cancer. This study also provides scientific basis for identifying novel biomarkers for the diagnosis and treatment of cancer.     

Glyoxalase-I is a novel prognosis factor associated with gastric cancer progression

Glyoxalase I (GLO1), a methylglyoxal detoxification enzyme, is implicated in the progression of human malignancies. The role of GLO1 in gastric cancer development or progression is currently unclear. The expression of GLO1 was determined in primary gastric cancer specimens using quantitative polymerase chain reaction, immunohistochemistry (IHC), and western blotting analyses. GLO1 expression was higher in gastric cancer tissues, compared with that in adjacent noncancerous tissues. Elevated expression of GLO1 was significantly associated with gastric wall invasion, lymph node metastasis, and pathological stage, suggesting a novel role of GLO1 in gastric cancer development and progression. The 5-year survival rate of the lower GLO1 expression groups was significantly greater than that of the higher expression groups (log rank P = 0.0373) in IHC experiments. Over-expression of GLO1 in gastric cancer cell lines increases cell proliferation, migration and invasiveness. Conversely, down-regulation of GLO1 with shRNA led to a marked reduction in the migration and invasion abilities. Our data strongly suggest that high expression of GLO1 in gastric cancer enhances the metastasis ability of tumor cells in vitro and in vivo, and support its efficacy as a potential marker for the detection and prognosis of gastric cancer.     

KIF14 promotes tumor progression and metastasis and is an independent predictor of poor prognosis in human gastric cancer

The kinesin family member 14 (KIF14) is a potential oncogene and is involved in the metastasis of various cancers. Nevertheless, its function in gastric cancer (GC) remains poorly defined. The expression of KIF14 was examined in GC cell lines and a clinical cohort of GC specimens by qPCR, western blotting and immunohistochemistry (IHC) staining. The relationship between KIF14 expression and the clinicopathological features was analyzed. The effect of KIF14 on cell proliferation, colony formation, invasion and migration were investigated in vitro and in vivo. The expression of KIF14 was significantly increased in the GC tissues and cell lines. High KIF14 expression was associated with tumor stage, tumor-node-metastasis (TNM) stage and metastasis. KIF14 was an independent prognostic factor for the overall survival of GC, and a higher expression of KIF14 predicted a poorer survival. KIF14 silencing resulted in attenuated proliferation, invasion and migration in human gastric cancer cells, whereas KIF14 ectopic expression facilitated these biological abilities. Notably, the depressed expression of KIF14 inhibited Akt phosphorylation, while overexpressed KIF14 augmented Akt phosphorylation. Additionally, there was a significant correlation between the expression of KIF14 and p?Akt in GC tissues. Importantly, the proliferation, invasion and migration of the GC cells, which was promoted by KIF14 overexpression, was abolished by the Akt inhibitor MK-2206, while Akt overexpression greatly rescued the effects induced by KIF14 knockdown. Our findings are the first to demonstrate that KIF14 is overexpressed in GC, is correlated with poor prognosis and plays a crucial role in the progression and metastasis of GC.     

IL-17 is associated with poor prognosis and promotes angiogenesis via stimulating VEGF production of cancer cells in colorectal carcinoma

IL-17, which exerts strong pro-inflammatory effects, has emerged as an important mediator in inflammation-associated cancer. However, the characteristics of IL-17-producing cells, the relevance of IL-17 to clinical parameters and its function in the development and progression of colorectal carcinoma still remain to be explored. In the present study, we first found the levels of IL-17 producing cells were significantly increased in the tumor regions of samples from colorectal carcinoma patients compared with non-tumor regions. Confocal microscopic analysis showed co-staining of IL-17 with CD4 and CD68, indicating IL-17 in colorectal carcinoma was expressed by macrophage and Th17. High expression of IL-17 was associated with high microvessel density. Univariate and multivariate analysis revealed that IL-17 was an independent prognostic factor for overall survival. To explore the underlying mechanisms of IL-17 in angiogenesis, we used PCR-array to find pro-angiogenic factor in cancer cells specifically induced by IL-17, then validated VEGF as one of factors in IL-17-mediated angiogenesis with the use of quantitative RT-PCR, ELISA and VEGF immunohistochemistry. Our results propose IL-17 as a novel indicator of prognosis in the patients with colorectal carcinoma and could serve as a novel therapeutic target for colorectal carcinoma, furthermore our results indicate that IL-17 producing cells may facilitate development of colorectal carcinoma by fostering angiogenesis via promote VEGF production from cancer cells.     

Interaction with AEG-1 and MDM2 is associated with glioma development and progression and correlates with poor prognosis

Glioma is the most common central nervous system tumor with poor prognosis. The AEG-1 (Astrocyte Elevated Gene 1) gene displays oncogenic characteristics, including proliferation, metastasis, chemoresistance, invasion, and evasion of apoptosis, and is strongly linked to the occurrence of glioma. Here, we elucidated the potential contribution of AEG-1 in human glioma pathogenesis. In glioma cells, AEG-1 could directly interact with Murine Double Minute-2 (MDM2) protein resulting in MDM2-p53-mediated cell proliferation and apoptosis. MDM2 is being revealed as an oncoprotein, which is involved in many human cancers progression. By immunohistochemical and a multivariate analysis, expressions of AEG-1 and MDM2 were elevated in glioma and high AEG-1 and MDM2 expressions were showed to be correlated with poor prognosis. AEG-1-MDM2 interaction prolonged stabilization of MDM2 where AEG-1 inhibited ubiquitination and subsequent proteasome-mediated degradation of MDM2 protein. Moreover, slicing AEG-1 blocked MDM2 expression and then impacted MDM2-p53 pathway that influenced cell proliferation and apoptosis. These findings uncover a novel AEG-1-MDM2 interplay by which AEG-1 augments glioma progression and reveal a viable potential therapy for the treatment of glioma patients.     

Overexpression of CARMA3 in non-small-cell lung cancer is linked for tumor progression

We aimed to investigate the clinical significance of the expression of novel scaffold protein CARMA3 in non-small-cell lung cancer (NSCLC) and the biological function of CARMA3 in NSCLC cell lines. We observed moderate to high CARMA3 staining in 68.8% of 141 NSCLC specimens compared to corresponding normal tissues. The overexpression of CARMA3 was significantly correlated with TNM stage (P = 0.022) and tumor status (P = 0.013). CARMA3 upregulation also correlated with a shorter survival rate of patients of nodal status N0 (P = 0.042)as well as the expression of epidermal growth factor receptor (EGFR) (P = 0.009). In EGFR mutation positive cases, CARMA3 expression was much higher (87.5%) compared to non-mutation cases (66.1%). In addition, we observed that knockdown of CARMA3 inhibits tumor cell proliferation and invasion, and induces cell cycle arrest at the boundary between the G1 and S phase. We further demonstrated a direct link between CARMA3 and NF-κB activation. The change of biological behavior in CARMA3 knockdown cells may be NF-κB-related. Our findings demonstrated, for the first time, that CARMA3 was overexpressed in NSCLC and correlated with lung cancer progression, EGFR expression, and EGFR mutation. CARMA3 could serve as a potential companion drug target, along with NF-kB and EGFR in EGFR-mutant lung cancers.