Effect on the expression of MMP-2, MT-MMP in laryngeal carcinoma Hep-2 cell line by antisense glucose transporter-1

Quantitative proteomics identified a novel invasion biomarker associated with EMT in pituitary adenomas

BACKGROUND

Complete resection of invasive pituitary adenoma is usually difficult, resulting in a high recurrence rate. Therefore, it is needed to find potential diagnostic markers and therapeutic targets for invasive pituitary adenoma.

METHODS

We collected samples from patients with invasive and non-invasive pituitary adenomas from Beijing Tiantan Hospital for protein extraction and quantitative analysis. We identified differential proteins (DEPs) by differential analysis of the two groups. The intersection of differential proteins related to invasion and epithelial-mesenchymal transition (EMT) in the GeneCards database was identified as EMT-DEPs. The protein network of EMT-DEPs was analyzed using the STRING database and Cytoscape software, and the hub EMT-DEPs were obtained by the MCC algorithm of the cytoHubba plugin. Correlation analysis was used to obtain the interpairing proteins among EMT-DEPs, and core EMT-DEPs were identified based on the number of paired proteins. The Venn program was used to identify the intersection of hub EMT-DEPs and core EMT-DEPs as key EMT-DEPs. Finally, a series of analyses plus experiments were used to verify the correlation of the target protein with invasion and EMT in pituitary adenoma.

RESULTS

Quantitative comparison of proteins between invasive and non-invasive pituitary adenomas indicated 833 differential proteins. The overlaps of EMT-related proteins and differential proteins consisted of 46 EMT-DEPs. There were 6 intersections between the hub EMT-DEPs and core EMT-DEPs. Using quantitative protein data and GSE169498 chip, we found that solute carrier family 2 member 1 (SLC2A1) was our target protein. SLC2A1 was significantly correlated with the invasiveness of pituitary adenoma, and the ROC curve was satisfactory. The functions and pathways of SLC2A1 and paired protein enrichment were closely linked to the EMT. Consistently, SLC2A1 expression was significantly and positively correlated with the expression of classical markers of EMT. The final experiment revealed that SLC2A1 was significantly upregulated in invasive pituitary adenoma.

CONCLUSION

SLC2A1 is significantly upregulated in invasive pituitary adenoma with satisfactory predictive value. It may regulate EMT. It may be a potential diagnostic marker for invasive pituitary adenoma.

The Effect of GLUT1 on Survival Rate and the Immune Cell Infiltration of Lung Adenocarcinoma and Squamous Cell Carcinoma: A Meta and Bioinformatics Analysis

BACKGROUND

Lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) are two major subtypes of non-small cell lung cancer (NSCLC). Studies have shown that abnormal expression of glucose transport type 1 (GLUT1) in NSCLC patients has been associated with progression, aggressiveness, and poor clinical outcome. However, the clinical effect of GLUT1 expression on LUAD and LUSC is unclear.

OBJECTIVE

This study aims to learn more about the character of GLUT1 in LUAD and LUSC.

METHODS

A meta-analysis was performed to evaluate the GLUT1 protein level, and bioinformatics analysis was used to detect the GLUT1 mRNA expression level, survival differences, and the infiltration abundance of immune cells in samples from TCGA. Meanwhile, functional and network analysis was conducted to detect important signaling pathways and key genes with the Gene Expression Omnibus (GEO) dataset.

RESULTS

Our results showed that GLUT1 was over-expressed both in LUAD and LUSC. LUAD patients with high GLUT1 expression had a poor prognosis. Additionally, GLUT1 was related to B cell and neutrophil infiltration of LUAD. In LUSC, GLUT1 was correlated with tumor purity, B cell, CD8⁺ T cell, CD4⁺ T cell, macrophage, neutrophil, and dendritic cell infiltration. The GEO dataset analysis results suggested GLUT1 potentially participated in the p53 signaling pathway and metabolism of xenobiotics by cytochrome P450 and was associated with KDR, TOX3, AGR2, FOXA1, ERBB3, ANGPT1, and COL4A3 gene in LUAD and LUSC.

CONCLUSION

GLUT1 might be a potential biomarker for aggressive progression and poor prognosis in LUAD, and a therapeutic biomarker in LUSC.

Solute carriers as potential oncodrivers or suppressors: their key functions in malignant tumor formation

Solute carrier (SLC) transporters are primarily known for their function in the transportation of various exogenous/endogenous substances via influx/efflux mechanisms. In addition to their diverse role in several tumor-modulating functions, such as proliferation, migration, angiogenesis, epithelial-mesenchymal transition (EMT), epigenetic modification, chemoresistance, immunoregulation, and oncometabolism, influx/efflux-independent contributions of SLCs in the activation of various signaling network cascades that might drive metastatic tumor formation have also been uncovered. Disappointingly, even after two decades and the discovery of >450 SLCs, many of their members remain orphans in terms of cancer pathogenesis. In this review, we summarize the current understanding of the tumor-modulating functions, mechanisms, and complexity of SLCs, as well as their potential as targets for cancer therapy.

The clinicopathologic impacts and prognostic significance of GLUT1 expression in patients with lung cancer: A meta-analysis

BACKGROUND

Accumulating studies have reported that GLUT1 is aberrantly expressed in lung cancer; nevertheless, the clinicopathologic significance and the prognostic role of GLUT1 still remain controversial. The aim of this meta-analysis was to identify the clinicopathologic and prognostic implications of the GLUT1 expression in lung cancer patients.

MATERIALS AND METHODS

Databases with literature published in English, including Cochrane Library, Embase, Web of Science, and PubMed, and the China National Knowledge Infrastructure (CNKI) and WanFang database in Chinese were searched comprehensively for relevant studies in August 2017. The pooled odds ratio (OR) or hazard ratio (HR) with 95% confidence intervals (CIs) were calculated to evaluate the clinicopathologic significance and prognostic value of GLUT1 in lung cancer.

RESULTS

A total of 26 studies (2653 cases) were included in the current study. Totally, 1423 patients from nineteen studies were included to assess the relationships between GLUT1 and clinicopathological parameters, the pooled OR indicated that positive GLUT1 expression was significantly related with classification (adenocarcinomas vs. squamous carcinomas, OR = 0.276, 95% CIs: 0.117-0.651, P = 0.003), tumor differentiation (G3-4 vs. G2~1, OR = 1.944, 95% CIs: 1.384-2.730; P < 0.001), lymph node metastasis (positive vs. negative, OR = 3.65, 95% CIs: 1.82-7.32, P < 0.001),tumor size (large tumor size vs. small tumor size, OR = 2.03, 95% CI: 1.42-2.91, P < 0.001), and advanced tumor stages (OR = 2.527, 95% CIs: 1.325-4.820). Regarding the significance of GLUT1 in the overall survival (OS) of lung cancer, the pooled HRs with 1731 lung cancer patients was 1.41 (P = 0.002; 95% CIs: 1.13-1.76). Additionally, the overexpression of GLUT1 could significantly predict the shorter disease-free survival (HR = 1.68, 95% CIs: 1.01-2.79) and disease-specific survival (HR = 1.59, 95% CIs: 1.11-2.29).

CONCLUSIONS

A positive expression of GLUT1 significantly predicts a poor prognosis in lung cancer patients. GLUT1 may server as a helpful biomarker and a potential target for the treatment strategies of lung cancer.

High-concentration glucose enhances invasion in invasive ductal breast carcinoma by promoting Glut1/MMP2/MMP9 axis expression

Type 2 diabetes mellitus (T2DM) has been considered to be a risk factor for numerous human cancers. Hyperglycemia is one of the most direct internal environmental changes for patients with T2DM. Increasing evidence reveals that a high concentration of glucose can promote tumor progression, while its role for migration and invasion of invasive ductal breast carcinoma (IDBC) cells remains unclear. In the present study, it was demonstrated that IDBC patients with T2DM suffered an increased tumor size and more frequent lymphatic and distant metastasis compared with those without T2DM (P<0.05). MCF-7 breast carcinoma cells, which were cultured in a high glucose concentration medium (25.00 mM), exhibited increased invasion (P<0.05). In addition, the expression of glucose transporters (Gluts), matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) in IDBC tissues with T2DM was significantly higher compared to those without T2DM. Downregulation of glucose transporter 1 (Glut1) by small interfering RNA may markedly suppress MCF-7 cell invasion as well as the expression of MMP2 and MMP9. These results suggest that T2DM can affect the malignant features of tumors in IDBC. The high glucose concentration in the tumor microenvironment may enhance IDBC invasion via upregulating Glut1/MMP2/MMP9 axis expression.

Apigenin inhibits the proliferation of adenoid cystic carcinoma via suppression of glucose transporter-1

Apigenin is a natural phyto-oestrogen flavonoid, which exerts various biological effects, including anti-oxidative, anti-inflammatory and anticancer activities. In addition, apigenin has recently been reported to target hypoxic markers; however, there are currently no studies regarding the association between apigenin and glucose transporter-1 (GLUT-1) in adenoid cystic carcinoma (ACC). The present study investigated whether apigenin inhibits the proliferation of ACC cells or suppresses the expression of GLUT-1 in ACC cells. The results of the present study demonstrated that apigenin inhibits ACC-2 cell growth in a dose- and time-dependent manner. Treatment with apigenin also induced apoptosis and G₂/M-phase arrest in a dose- and time-dependent manner. Corresponding with the above results, the expression levels of GLUT-1 were significantly decreased following treatment in a dose- and time-dependent manner. These results suggest that the inhibition of ACC-2 cell growth by apigenin may be due to the decreased expression of GLUT-1.

Expression and significance of glucose transporter-1, P-glycoprotein, multidrug resistance-associated protein and glutathione S-transferase-π in laryngeal carcinoma

Increasing glucose transporter-1 (GLUT-1) activity is one of the most important ways to increase the cellular influx of glucose. We previously demonstrated that increased GLUT-1 expression was an independent predictor of survival in patients with laryngeal carcinoma. Thus, GLUT-1 may present a novel therapeutic target in laryngeal carcinoma. In this study, the expression of GLUT-1, P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1) and glutathione S-transferase-π (GST-π) in laryngeal carcinomas was investigated by immunohistochemistry. Additionally, possible correlations between GLUT-1 and P-gp, MRP1 and GST-π and various clinicopathological parameters were analyzed. In this study, 52.9% (18/34), 58.8% (20/34), 20.6% (7/34) and 58.8% (20/34) of the laryngeal carcinomas were positive for GLUT-1, P-gp, MRP1 and GST-π, respectively. The expression of GLUT-1, P-gp, MRP1 and GST-π was higher in laryngeal carcinoma specimens when compared with laryngeal precancerous lesions (P<0.05). Pearson’s correlation analysis showed correlations between GLUT-1 and P-gp (r=0.364; P=0.034), GLUT-1 and MRP1 (r=0.359; P=0.037) and P-gp and GST-π (r=0.426; P=0.012). GLUT-1 expression was found to significantly correlate with tumor-node-metastasis classification (P=0.02) and clinical stage (P=0.037). Furthermore, P-gp was found to significantly correlate with clinical stage (P=0.026). Univariate analysis showed that MRP1 expression was significantly associated with poor survival (c²=5.16; P=0.023). Multivariate analysis revealed that lymph node metastasis (P=0.009) and MRP1 overexpression (P=0.023) were significant predictors of poor survival. In the present study, the expression of GLUT-1, P-gp, MRP1 and GST-π in laryngeal carcinomas was investigated, as well as the correlations between these proteins. P-gp was found to significantly correlate with clinical stage, while MRP1 overexpression was significantly associated with poor survival.

Gene and protein expression of glucose transporter 1 and glucose transporter 3 in human laryngeal cancer-the relationship with regulatory hypoxia-inducible factor-1α expression, tumor invasiveness, and patient prognosis

Increased glucose uptake mediated by glucose transporters and reliance on glycolysis are common features of malignant cells. Hypoxia-inducible factor-1α supports the adaptation of hypoxic cells by inducing genes related to glucose metabolism. The contribution of glucose transporter (GLUT) and hypoxia-inducible factor-1α (HIF-1α) activity to tumor behavior and their prognostic value in head and neck cancers remains unclear. The aim of this study was to examine the predictive value of GLUT1, GLUT3, and HIF-1α messenger RNA (mRNA)/protein expression as markers of tumor aggressiveness and prognosis in laryngeal cancer. The level of hypoxia/metabolic marker genes was determined in 106 squamous cell laryngeal cancer (SCC) and 73 noncancerous matched mucosa (NCM) controls using quantitative real-time PCR. The related protein levels were analyzed by Western blot. Positive expression of SLC2A1, SLC2A3, and HIF-1α genes was noted in 83.9, 82.1, and 71.7 % of SCC specimens and in 34.4, 59.4, and 62.5 % of laryngeal cancer samples. Higher levels of mRNA/protein for GLUT1 and HIF-1α were noted in SCC compared to NCM (p < 0.05). SLC2A1 was found to have a positive relationship with grade, tumor front grading (TFG) score, and depth and mode of invasion (p < 0.05). SLC2A3 was related to grade and invasion type (p < 0.05). There were also relationships of HIF-1α with pTNM, TFG scale, invasion depth and mode, tumor recurrences, and overall survival (p < 0.05). In addition, more advanced tumors were found to be more likely to demonstrate positive expression of these proteins. In conclusion, the hypoxia/metabolic markers studied could be used as molecular markers of tumor invasiveness in laryngeal cancer.

Glucose transporter-1 expression in CD133+ laryngeal carcinoma Hep-2 cells

CD133 is a useful putative marker of cancer stem cells (CSCs) in human laryngeal tumors. Numerous studies have demonstrated that CD133+ CSCs possess higher clonogenicity, invasiveness and tumorigenesis compared with CD133- cells. Recently, interest in the Warburg effect in the microenvironment of CSCs has escalated. The Warburg effect dictates that cancer cells rely on glycolysis rather than oxidative phosphorylation under aerobic conditions. In numerous cancer cells, glucose is used mainly for the glycolytic pathway. Stem cells express high levels of glycolytic enzymes and rely mostly on glycolysis to meet their energy demands. Glucose is transported through cell membranes by glucose transporters (Glut). Studies of Glut-1 expression in CSCs are limited. In the present study, we investigated the proliferation of CD133+ Hep-2 cells and whether Glut-1 is expressed in laryngeal carcinoma CD133+ Hep-2 cells. Real-time reverse transcription-polymerase chain reaction (RT-PCR) demonstrated that the size of the CD133 product was 213 bp. Dissociation curve analysis demonstrated only the expected peaks at 82.1˚C for CD133. The mean ΔCt of CD133 expression was 10.98. Prior to isolation, the CD133+ fraction was 1.2% by fluorescence-activated cell sorting (FACS) analysis. Following isolation, the CD133+ fraction was increased to 76.1%. Successive tests also demonstrated that cells grew well following isolation. The proliferation of CD133+ and CD133- cells was not different during the first 3 days (P>0.05). From day 4, the proliferation capacity of CD133+ cells in vitro was higher than that of CD133- cells (P<0.05). The mean ΔCt of Glut-1 mRNA expression was 1.78 for CD133+ cells and 1.00 for CD133- cells (P<0.05). The mean Glut-1 protein values in CD133+ and CD133- Hep-2 cells relative to β-tubulin were 0.48 ± 0.02 and 0.21 ± 0.03 (µg/µl), respectively (P<0.05). In conclusion, CD133+ cells demonstrated higher proliferation. Glut-1 mRNA and protein levels were higher in CD133+ than in CD133- cells. Our results suggest that Glut-1 is important in the energy supply of laryngeal CD133+ Hep-2 cells and Glut-1 may represent a potential therapeutic target for the inhibition of the proliferation of laryngeal CSCs.

Transfected early growth response gene-1 DNA enzyme prevents stenosis and occlusion of autogenous vein graft in vivo

The aim of this study was to detect the inhibitory action of the early growth response gene-1 DNA enzyme (EDRz) as a carrying agent by liposomes on vascular smooth muscle cell proliferation and intimal hyperplasia. An autogenous vein graft model was established. EDRz was transfected to the graft vein. The vein graft samples were obtained on each time point after surgery. The expression of the EDRz transfected in the vein graft was detected using a fluorescent microscope. Early growth response gene-1 (Egr-1) mRNA was measured using reverse transcription-PCR and in situ hybridization. And the protein expression of Egr-1 was detected by using western blot and immunohistochemistry analyses. EDRz was located at the media of the vein graft from 2 to 24 h, 7 h after grafting. The Egr-1 protein was mainly located in the medial VSMCs, monocytes, and endothelium cells during the early phase of the vein graft. The degree of VSMC proliferation and thickness of intima were obviously relieved compared with the no-gene therapy group. EDRz can reduce Egr-1 expression in autogenous vein grafts, effectively restrain VSMC proliferation and intimal hyperplasia, and prevent vascular stenosis and occlusion after vein graft.

Effect of antisense oligodeoxynucleotides glucose transporter-1 on enhancement of radiosensitivity of laryngeal carcinoma

PURPOSE

Laryngeal carcinomas always resist to radiotherapy. Hypoxia is an important factor in radioresistance of laryngeal carcinoma. Glucose transporter-1 (GLUT-1) is considered to be a possible intrinsic marker of hypoxia in malignant tumors. We speculated that the inhibition of GLUT-1 expression might improve the radiosensitivity of laryngeal carcinoma.

METHODS

We assessed the effect of GLUT-1 expression on radioresistance of laryngeal carcinoma and the effect of GLUT-1 expressions by antisense oligodeoxynucleotides (AS-ODNs) on the radiosensitivity of laryngeal carcinoma in vitro and in vivo.

RESULTS

After transfection of GLUT-1 AS-ODNs: MTS assay showed the survival rates of radiation groups were reduced with the prolongation of culture time (p<0.05); Cell survival rates were significantly reduced along with the increasing of radiation dose (p<0.05). There was significant difference in the expression of GLUT-1mRNA and protein in the same X-ray dose between before and after X-ray radiation (p<0.05). In vivo, the expressions of GLUT-1 mRNA and protein after 8Gy radiation plus transfection of GLUT-1 AS-ODNs were significant decreased compared to 8Gy radiation alone (p<0.001).

CONCLUSION

Radioresistance of laryngeal carcinoma may be associated with increased expression of GLUT-1 mRNA and protein. GLUT-1 AS-ODNs may enhance the radiosensitivity of laryngeal carcinoma mainly by inhibiting the expression of GLUT-1.