Glucose transporter Glut-1 is detectable in pen-necrotic regions in many human tumor types but not normal tissues: Study using tissue microarrays

The hypoxic tumor microenvironment is associated with malignant progression and poor treatment response. The glucose transporter Glut-1 is a prognostic factor and putative hypoxia marker. So far, studies of Glut-1 in cancer have utilised conventional immunohistochemical analysis in a series of individual biopsy or surgical specimens. Tissue microarrays, however, provide a rapid, inexpensive means of profiling biomarker expression. To evaluate hypoxia markers, tissue cores must show architectural features of hypoxia, i.e. viable tissue surrounding necrotic regions. Glut-1 may be a useful biomarker to validate tissue microarrays for use in studies of hypoxia-regulated genes in cancer. In this study, we carried out immunohistochemical detection of Glut-1 protein in many tumor and normal tissue types in a range of tissue microarrays. Glut-1 was frequently found in peri-necrotic regions, occurring in 9/34 lymphomas, 6/12 melanomas, and 5/16 glioblastomas; and in 43/54 lung, 22/84 colon, and 23/60 ovarian tumors. Expression was rare in breast (6/40) and prostate (1/57) tumors, and in normal tissue, was restricted to spleen, tongue and CNS endothelium. In conclusion, tissue microarrays enable the observation of Glut-1 expression in peri-necrotic regions, which may be linked to hypoxia, and reflect previous studies showing differential Glut-1 expression across tumor types and non malignant tissue

Could GLUT12 be a Potential Therapeutic Target in Cancer Treatment? A Preliminary Report

Background: Recent studies proposed GLUT12 to be a major glucose transporter involved in the glycolytic metabolism of cancer cells. Methods: GLUT12 expression was determined by immunohistochemistry in a selection of cancer cell lines and a tumour spheroid model. Results: GLUT12 expression was high in A549 and RH-36; low in HT29; and absent in NB-EB cancer cell lines. GLUT12 expression was located in the necrotic centre of HT29 spheroids, which is characterised by anaerobic metabolism. Conclusion: The data supports the involvement of GLUT12 in the glycolytic metabolism of cancer cells and therefore, its potential as a novel therapeutic target for cancer treatment

A phenomenological approach to the simulation of metabolism and proliferation dynamics of large tumour cell populations

A major goal of modern computational biology is to simulate the collective behaviour of large cell populations starting from the intricate web of molecular interactions occurring at the microscopic level. In this paper we describe a simplified model of cell metabolism, growth and proliferation, suitable for inclusion in a multicell simulator, now under development (Chignola R and Milotti E 2004 Physica A 338 261-6). Nutrients regulate the proliferation dynamics of tumor cells which adapt their behaviour to respond to changes in the biochemical composition of the environment. This modeling of nutrient metabolism and cell cycle at a mesoscopic scale level leads to a continuous flow of information between the two disparate spatiotemporal scales of molecular and cellular dynamics that can be simulated with modern computers and tested experimentally.Comment: 58 pages, 7 figures, 3 tables, pdf onl

The prognostic value of the hypoxia markers CA IX and GLUT 1 and the cytokines VEGF and IL 6 in head and neck squamous cell carcinoma treated by radiotherapy ± chemotherapy

BACKGROUND: Several parameters of the tumor microenvironment, such as hypoxia, inflammation and angiogenesis, play a critical role in tumor aggressiveness and treatment response. A major question remains if these markers can be used to stratify patients to certain treatment protocols. The purpose of this study was to investigate the inter-relationship and the prognostic significance of several biological and clinicopathological parameters in patients with head and neck squamous cell carcinoma (HNSCC) treated by radiotherapy ± chemotherapy. METHODS: We used two subgroups of a retrospective series for which CT-determined tumoral perfusion correlated with local control. In the first subgroup (n = 67), immunohistochemistry for carbonic anhydrase IX (CA IX) and glucose transporter-1 (GLUT-1) was performed on the pretreatment tumor biopsy. In the second subgroup (n = 34), enzyme linked immunosorbent assay (ELISA) was used to determine pretreatment levels of the cytokines vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) in serum. Correlation was investigated between tumoral perfusion and each of these biological markers, as well as between the markers mutually. The prognostic value of these microenvironmental parameters was also evaluated. RESULTS: For CA IX and GLUT-1, the combined assessment of patients with both markers expressed above the median showed an independent correlation with local control (p = 0.02) and disease-free survival (p = 0.04) with a trend for regional control (p = 0.06). In the second subgroup, IL-6 pretreatment serum level above the median was the only independent predictor of local control (p = 0.009), disease-free survival (p = 0.02) and overall survival (p = 0.005). CONCLUSION: To our knowledge, we are the first to report a link in HNSCC between IL-6 pretreatment serum levels and radioresistance in vivo. This link is supported by the strong prognostic association of pretreatment IL-6 with local control, known to be the most important parameter to judge radiotherapy responses. Furthermore, the combined assessment of CA IX and GLUT-1 correlated independently with prognosis. This is a valuable indication that a combined approach is important in the investigation of prognostic markers

The hypoxia marker CAIX is prognostic in the UK phase III VorteX-Biobank cohort: an important resource for translational research in soft tissue sarcoma

BACKGROUND: Despite high metastasis rates, adjuvant/neoadjuvant systemic therapy for localised soft tissue sarcoma (STS) is not used routinely. Progress requires tailoring therapy to features of tumour biology, which need exploration in well-documented cohorts. Hypoxia has been linked to metastasis in STS and is targetable. This study evaluated hypoxia prognostic markers in the phase III adjuvant radiotherapy VorteX trial. METHODS: Formalin-fixed paraffin-embedded tumour biopsies, fresh tumour/normal tissue and blood were collected before radiotherapy. Immunohistochemistry for HIF-1α, CAIX and GLUT1 was performed on tissue microarrays and assessed by two scorers (one pathologist). Prognostic analysis of disease-free survival (DFS) used Kaplan-Meier and Cox regression. RESULTS: Biobank and outcome data were available for 203 out of 216 randomised patients. High CAIX expression was associated with worse DFS (hazard ratio 2.28, 95% confidence interval: 1.44-3.59, P<0.001). Hypoxia-inducible factor-1α and GLUT1 were not prognostic. Carbonic anhydrase IX remained prognostic in multivariable analysis. CONCLUSIONS: The VorteX-Biobank contains tissue with linked outcome data and is an important resource for research. This study confirms hypoxia is linked to poor prognosis in STS and suggests that CAIX may be the best known marker. However, overlap between single marker positivity was poor and future work will develop an STS hypoxia gene signature to account for tumour heterogeneity

Comparison of hypoxia transcriptome in vitro with in vivo gene expression in human bladder cancer

Hypoxia-inducible genes have been linked to the aggressive phenotype of cancer. However, nearly all work on hypoxia-regulated genes has been conducted in vitro on cell lines. We investigated the hypoxia transcriptome in primary human bladder cancer using cDNA microarrays to compare genes induced by hypoxia in vitro in bladder cancer cell line EJ28 with genes upregulated in 39 bladder tumour specimens (27 superficial and 12 invasive). We correlated array mRNA fold changes with carbonic anhydrase 9 (CA IX) staining of tumours as a surrogate marker of hypoxia. Of 6000 genes, 32 were hypoxia inducible in vitro more than two-fold, five of which were novel, including lactate transporter SLC16A3 and RNAse 4. Eight of 32 hypoxia-inducible genes in vitro were also upregulated on the vivo array. Vascular endothelial growth factor mRNA was upregulated two-fold by hypoxia and 2–18-fold in 31 out of 39 tumours. Glucose transporter 1 was also upregulated on both arrays mRNA, and fold changes on the in vivo array significantly correlated with CA IX staining of tumours (P=0.008). However, insulin-like growth factor binding protein 3 mRNA was the most strongly differentially expressed gene in both arrays and this confirmed its upregulation in urine of bladder cancer patients (n=157, P<0.01). This study defines genes suitable for an in vivo hypoxia ‘profile', shows the heterogeneity of the hypoxia response and describes new hypoxia-regulated genes

Could GLUT12 be a potential therapeutic target in cancer treatment? A preliminary report

Background: Recent studies proposed GLUT12 to be a major glucose transporter involved in the glycolytic metabolism of cancer cells. Methods: GLUT12 expression was determined by immunohistochemistry in a selection of cancer cell lines and a tumour spheroid model. Results: GLUT12 expression was high in A549 and RH-36; low in HT29; and absent in NB-EB cancer cell lines. GLUT12 expression was located in the necrotic centre of HT29 spheroids, which is characterised by anaerobic metabolism. Conclusion: The data supports the involvement of GLUT12 in the glycolytic metabolism of cancer cells and therefore, its potential as a novel therapeutic target for cancer treatment

Hypoxia and oxidative stress in breast cancer: Tumour hypoxia – therapeutic considerations

Conclusive research has shown that regions of acute/chronic hypoxia, which exist within the majority of solid tumours, have a profound influence on the therapeutic outcome of cancer chemotherapy and radiotherapy and are a strong prognostic factor of disease progression and survival. A strong argument therefore exists for assessing the hypoxic fraction of tumours, prior to patient treatment, and to tailor this treatment accordingly. Tumour hypoxia also provides a powerful physiological stimulus that can be exploited as a tumour-specific condition, allowing for the rationale design of hypoxia-activated anticancer drugs or novel hypoxia-regulated gene therapy strategies