Potential Role of Sugar Transporters in Cancer and Their Relationship with Anticancer Therapy

Sugars, primarily glucose and fructose, are the main energy source of cells. Because of their hydrophilic nature, cells use a number of transporter proteins to introduce sugars through their plasma membrane. Cancer cells are well known to display an enhanced sugar uptake and consumption. In fact, sugar transporters are deregulated in cancer cells so they incorporate higher amounts of sugar than normal cells. In this paper, we compile the most significant data available about biochemical and biological properties of sugar transporters in normal tissues and we review the available information about sugar carrier expression in different types of cancer. Moreover, we describe the possible pharmacological interactions between drugs currently used in anticancer therapy and the expression or function of facilitative sugar transporters. Finally, we also go into the insights about the future design of drugs targeted against sugar utilization in cancer cells

Colorectal Cancer Classification and Cell Heterogeneity: A Systems Oncology Approach

Colorectal cancer is a heterogeneous disease that manifests through diverse clinical scenarios. During many years, our knowledge about the variability of colorectal tumors was limited to the histopathological analysis from which generic classifications associated with different clinical expectations are derived. However, currently we are beginning to understand that under the intense pathological and clinical variability of these tumors there underlies strong genetic and biological heterogeneity. Thus, with the increasing available information of inter-tumor and intra-tumor heterogeneity, the classical pathological approach is being displaced in favor of novel molecular classifications. In the present article, we summarize the most relevant proposals of molecular classifications obtained from the analysis of colorectal tumors using powerful high throughput techniques and devices. We also discuss the role that cancer systems biology may play in the integration and interpretation of the high amount of data generated and the challenges to be addressed in the future development of precision oncology. In addition, we review the current state of implementation of these novel tools in the pathological laboratory and in clinical practice.This work was supported by the “Galician Network for Colorectal Cancer Research (REGICC)”, funded by “Xunta de Galicia” (Ref. R2014/039), Spain. Federico Garrido would like to thank the financial support from the following institutions: “Instituto de Salud Carlos III” (CP03/0111, PI12/02031, PI08/1265, PI11/01022, PI11/01386, RETIC RD06/020, RD09/0076/00165, and PT13/0010/0039 projects; all actions co-funded with the European Regional Development Fund, FEDER), Spain; “Junta de Andalucía, Consejería de Salud e Innovación” (PI09/0382 project and CTS143 Research group), Spain; and European Commission (ENACT project: European Network for identification and validation of antigens and biomarkers in cancer and their application in clinical tumour immunology, LSHC-CT-2004-503306)

Clinical implications of epithelial cell plasticity in cancer progression

Mini-review[Abstract] In the last few years, the role of epithelial cell plasticity in cancer biology research has gained increasing attention. This concept refers to the ability of the epithelial cells to dynamically switch between different phenotypic cellular states. This programme is particularly relevant during the epithelial-to-mesenchymal transition (EMT) in cancer progression. During colonization, epithelial cells first activate the EMT programme to disseminate from a primary tumour to reach a distant tissue site. During this process, cells are transported into the circulation and are able to escape the immune system of the host. Then, a reverse process called mesenchymal-to-epithelial transition (MET) occurs on cells that settle in the distant organs. Although epithelial cell plasticity has an important impact on tumour biology, the clinical relevance of this concept remains to be recapitulated. In this review, we will update the current state of epithelial cell plasticity in cancer progression and its clinical implications for the design of therapeutic strategies, the acquisition of multidrug resistance, and future perspectives for the management of cancer patients.Instituto de Salud Carlos III; PI13/00250Xunta de Galicia; 10CSA916023PRXunta de Galicia; PS09/2

Role of the microtubule-targeting drug vinflunine on cell-cell adhesions in bladder epithelial tumour cells

Background: Vinflunine (VFL) is a microtubule-targeting drug that suppresses microtubule dynamics, showing anti-metastatic properties both in vitro and in living cancer cells. An increasing body of evidence underlines the influence of the microtubules dynamics on the cadherin-dependent cell-cell adhesions. E-cadherin is a marker of epithelial-to-mesenchymal transition (EMT) and a tumour suppressor; its reduced levels in carcinoma are associated with poor prognosis. In this report, we investigate the role of VFL on cell-cell adhesions in bladder epithelial tumour cells. Methods: Human bladder epithelial tumour cell lines HT1376, 5637, SW780, T24 and UMUC3 were used to analyse cadherin-dependent cell-cell adhesions under VFL treatment. VFL effect on growth inhibition was measured by using a MTT colorimetric cell viability assay. Western blot, immunofluorescence and transmission electron microscopy analyses were performed to assess the roles of VFL effect on cell-cell adhesions, epithelial-to-mesenchymal markers and apoptosis. The role of the proteasome in controlling cell-cell adhesion was studied using the proteasome inhibitor MG132. Results: We show that VFL induces cell death in bladder cancer cells and activates epithelial differentiation of the remaining living cells, leading to an increase of E-cadherin-dependent cell-cell adhesion and a reduction of mesenchymal markers, such as N-cadherin or vimentin. Moreover, while E-cadherin is increased, the levels of Hakai, an E3 ubiquitin-ligase for E-cadherin, were significantly reduced in presence of VFL. In 5637, this reduction on Hakai expression was blocked by MG132 proteasome inhibitor, indicating that the proteasome pathway could be one of the molecular mechanisms involved in its degradation. Conclusions: Our findings underscore a critical function for VFL in cell-cell adhesions of epithelial bladder tumour cells, suggesting a novel molecular mechanism by which VFL may impact upon EMT and metastasis

Circulating miR-200c and miR-141 and outcomes in patients with breast cancer

Research article[Abstract] Background. The deregulation of microRNAs in both tumours and blood has led to the search for microRNAs to indicate the presence of cancer and predict prognosis. We hypothesize the deregulation of miR-200c/miR-141 in the whole blood can identify breast cancer (BC), and could be developed into a prognostic signature. Methods. The expression of miR-200c and miR-141 were examined in bloods (57 stage I-IV BC patients and 20 age-matched controls) by quantitative reverse-transcription PCR. The associations of circulating microRNAs with clinic and pathological characteristics were analysed. Their effects on survival were analysed by the Kaplan-Meier method and Cox regressions. Results. MiR-200c was down regulated (P < 0.0001) in the blood of BC patients, yielded an area under the ROC curve of 0.79 (90% sensitivity, 70.2% specificity) in discriminating BC from controls. Circulating miR-141 was not discriminating. MiR-200c and miR-141 in the blood of BC patients were inversely correlated (P = 0.019). The miR-200c levels were numerically higher in stage IV and tumours with lower MIB-1. MiR-141 was significantly higher in the blood of patients with stage I-III, lymph node metastasis, and HER2 negative tumours. High blood expression of miR-200c and/or low expression of miR-141 was associated with unfavourable overall survival (hazard ratio, 3.89; [95% CI: 1.28-11.85]) and progression-free survival (3.79 [1.41–10.16]) independent of age, stage and hormonal receptors. Conclusions. Circulating miR-200c and miR-141 were deregulated in BC comparing with controls. Furthermore, miR-200c and miR-141 were independent prognostic factors and associated with distinct outcomes of BC patients.Instituto de Salud Carlos III (España); PI06-154

Prognostic impact of disseminated tumor cells and microRNA-17-92 cluster deregulation in gastrointestinal cancer

[Abstract] The presence of tumor cells in the bone marrow (BM) could be relevant to identifying high risk of disease progression and death in gastrointestinal cancer. However, the molecular profile associated with disseminated tumor cells (DTCs) homing to the BM has yet to be defined. MicroRNAs (miRNA) play key roles in cellular processes implicated in cancer. Thus, we investigated in 38 patients with colorectal, gastric or pancreatic cancer whether the presence of BM-DTCs is associated with a specific miRNA tumor profile and analyzed their potential prognostic impact. DTCs were detected by immunocytochemistry and anti-cytokeratin antibodies in 42.1% of the patients. miRNAs were isolated from formalin-fixed, paraffin-embedded tumors. qRT-PCR was used for miRNA profiling. No significant associations were found among DTC detection and miRNA deregulation. Kaplan-Meier curves demonstrated significantly reduced progression-free survival (PFS) and overall survival (OS) in the DTC-positive patients. Although miR-21 was upregulated in 90.6% of the tumors, no associations with outcomes were found. miR-17 and miR-20a (miRNA-17-92 cluster) were upregulated in 33.3 and 42.4%, respectively. Upregulation of both was correlated and found in 30.3%. Univariate analysis shows that increasing values for miR-20a were significantly associated with reduced PFS (HR 1.022; p=0.016) and OS (HR 1.027; p=0.003). In multivariate Cox models, DTC positivity (HR 4.07; p=0.005) and miR-17 overexpression (HR 2.11; p=0.003) were significantly associated with a higher risk of disease progression. The presence of DTCs in the BM (HR 3.98; p=0.010) and a miR-17 overexpression (HR 2.62; p<0.001) were also associated with a risk of death. Our study suggests that the presence of BM-DTCs and the upregulation of the miR-17-92 cluster in tumors are both significant but independent prognostic markers in gastrointestinal cancer patients.Instituto de Salud Carlos III; PI061541Galicia. Conselleria de Innovación, Industria e Comercio; PGIDT01PXI90001PRXunta de Galicia; PS 08/7

A novel procedure for protein extraction from formalin-fixed paraffin-embedded tissues

Most of the archived pathological specimens in hospitals are kept as formalin-fixed paraffin-embedded tissues (FFPE) for long-term preservation. Up to now, these samples are only used for immunohistochemistry in a clinical routine as it is difficult to recover intact protein from these FFPE tissues. Here, we report a novel, short time-consuming and cost-effective method to extract full-length, non-degraded proteins from FFPE tissues. This procedure is combined with an effective and non-toxic deparaffinisation process and an extraction method based on antigen-retrieval, high concentration of SDS and high temperature. We have obtained enough intact protein to be detected by Western blotting analysis. This technique will allow utilising these stored FFPE tissues in several applications for protein analysis helping to advance the translational studies in cancer and other diseases

Circulating miR-200c as a diagnostic and prognostic biomarker for gastric cancer

[Abstract] Background. MicroRNAs are aberrantly expressed and correlate with tumourigenesis and the progression of solid tumours. The miR-200 family determines the epithelial phenotype of cancer cells and regulates invasiveness and migration. Thus, we hypothesised that the quantitative detection of the miR-200 family as epithelial-specific microRNAs in the blood could be a useful clinical biomarker for gastric cancer (GC). Methods. We initially validated the expression levels of miR-200a, 200b, 200c and 141 in GC cell lines (n = 2) and blood from healthy controls (n = 19) using real-time quantitative reverse transcription PCR (qRT-PCR). The microarray expression profiles of the miR-200 family in 160 paired samples of non-tumour gastric mucosae and GC were downloaded through ArrayExpress and analysed. MiR-200c was selected for clinical validation. The qRT-PCR prospective assessment of miR-200c was performed using 67 blood samples (52 stage I-IV GC patients and 15 controls); the area under the receiver operating characteristic curve (AUC-ROC) was estimated. The Kaplan-Meier and Breslow-Wilcoxon tests were used to assess the correlation of miR-200c with overall and progression-free survival (OS and PFS). Multivariate analyses were performed using the Cox model. Results. The miR-200c blood expression levels in GC patients were significantly higher than in normal controls (p = 0.018). The AUC-ROC was 0.715 (p = 0.012). The sensitivity, specificity and accuracy rates of 65.4%, 100% and 73.1%, respectively, were observed. The levels of miR-200c in the blood above the cutoff defined by the ROC curve was found in 17.6% of stage I-II GC patients, 20.6% of stage III patients and 67.7% of stage IV patients (p < 0.001). The miR-200c expression levels were not associated with clinical or pathological characteristics or recent surgical procedures. There was a correlation (p = 0.016) with the number of lymph node metastases and the increased expression levels of miR-200c in blood were significantly associated with a poor OS (median OS, 9 vs 24 months; p = 0.016) and PFS (median PFS, 4 vs 11 months; p = 0.044). Multivariate analyses confirmed that the upregulation of miR-200c in the blood was associated with OS (HR = 2.24; p = 0.028) and PFS (HR = 2.27; p = 0.028), independent of clinical covariates. Conclusions. These data suggest that increased miR-200c levels are detected in the blood of gastric cancer patients. MiR-200c has the potential to be a predictor of progression and survival.Instituto de Salud Carlos III; PI061541Xunta de Galicia; PS08/7

A new scenario in metastatic renal cell carcinoma: a SOG‑GU consensus

[Abstract] Background This article describes and compares approved targeted therapies and the newer immunotherapy agents. Materials and methods This article especially performs an in-depth review of currently available data for tivozanib, explaining its mechanism of action, its safety profle and its role as an efcacy drug in the management of renal cancer. Results Despite the fact that the treatment of advanced RCC has been dramatically modifed in recent years, durable remissions are scarce and it remains a lethal disease. For frst- and second-line therapy, there is now growing evidence to guide the selection of the appropriate treatment. Conclusions Several TKIs are standard of care at diferent settings. Among those approved TKIs, tivozanib has similar efcacy than others with a better safety profle. The use of prognostic factors is critical to the selection of optimal therapy

Evaluation of the Adenocarcinoma-Associated Gene AGR2 and the Intestinal Stem Cell Marker LGR5 as Biomarkers in Colorectal Cancer

We aim to estimate the diagnostic performances of anterior gradient homolog-2 (AGR2) and Leucine-rich repeat-containing-G-protein-coupled receptor 5 (LGR5) in peripheral blood (PB) as mRNA biomarkers in colorectal cancer (CRC) and to explore their prognostic significance. Real-time PCR was used to analyze AGR2 and LGR5 in 54 stages I-IV CRC patients and 19 controls. Both mRNAs were significantly increased in PB from CRC patients compared to controls. The area under the receiver-operating characteristic curves were 0.722 (p = 0.006), 0.376 (p = 0.123) and 0.767 (p = 0.001) for AGR2, LGR5 and combined AGR2/LGR5, respectively. The AGR2/LGR5 assay resulted in 67.4% sensitivity and 94.7% specificity. AGR2 correlated with pT3–pT4 and high-grade tumors. LGR5 correlated with metastasis, R2 resections and high-grade. The progression-free survival (PFS) of patients with high AGR2 was reduced (p = 0.037; HR, 2.32), also in the stage I-III subgroup (p = 0.046). LGR5 indicated a poor prognosis regarding both PFS (p = 0.007; HR, 1.013) and overall survival (p = 0.045; HR, 1.01). High AGR2/LGR5 was associated with poor PFS (p = 0.014; HR, 2.8) by multivariate analysis. Our findings indicate that the assessment of AGR2 and LGR5 in PB might reflect the presence of circulating tumor cells (CTC) and stem cell like CTC in CRC. Increased AGR2 and LGR5 are associated with poor outcomes