Oxygenation of head and neck tumors

Lartigau, Éric; Ridant, Anne-Marie Le; Lambin, Philippe; Weeger, Pascal; Martin, Laurent; Sigal, R.; Lusinchi, A.; Luboinski, B.; Eschwège, F.; Guichard, M.

doi:10.1002/1097-0142(19930401)71:7<2319::aid-cncr2820710724>3.0.co;2-c

Cited by 155 publications

(55 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Tissue oxygen tension levels similar or even lower than those recorded in the transplanted islets have also been shown repeatedly in living tissue (37)(38)(39)(40). However, pancreatic ␤-cells normally have very high metabolic activity to meet the various demands for insulin secretion (41).…”

Section: Discussionmentioning

confidence: 53%

Markedly Decreased Oxygen Tension in Transplanted Rat Pancreatic Islets Irrespective of the Implantation Site

Carlsson¹,

Palm²,

Andersson³

et al. 2001

Diabetes

373

303

View full text Add to dashboard Cite

In this study, we syngeneically transplanted islets to three different implantation sites of diabetic and nondiabetic rats, then 9 -12 weeks later we measured the blood perfusion and compared the tissue partial pressure of oxygen (PO 2 ) levels of these transplanted islets to endogenous islets. Modified Clark microelectrodes (outer tip diameter 2-6 m) were used for the oxygen tension measurements, and islet transplant blood perfusion was recorded by laser-Doppler flowmetry (probe diameter 0.45 mm). The islet graft blood perfusion was similar in all islet grafts, irrespective of the implantation site. In comparison, the three implantation organs (the kidney cortex, liver, and spleen) differed markedly in their blood perfusion. There were no differences in islet graft blood perfusion between diabetic and nondiabetic recipients. Within native pancreatic islets, the mean PO 2 was ϳ40 mmHg; however, all transplanted islets had a mean PO 2 of ϳ5 mmHg. The oxygen tension of the grafts did not differ among the implantation sites. In diabetic recipients, an even lower PO 2 level was recorded in the islet transplants. We conclude that the choice of implantation site seems less important than intrinsic properties of the transplanted islets with regard to the degree of revascularization and concomitant blood perfusion. Furthermore, the mean PO 2 level in islets implanted to the kidney, liver, and spleen was markedly decreased at all three implantation sites when compared with native islets, especially in diabetic recipients. These results are suggestive of an insufficient oxygenization of revascularized transplanted islets, irrespective of the implantation site. Diabetes 50: -495, 2001A factor of potential importance in the failure of islet grafts is poor or inadequate engraftment of the islets in the implantation organ. Normally, pancreatic islets have a dense glomerular-like capillary network in which the capillaries course through the islet in a tortuous fashion that is ideal for the delivery of oxygen and nutrients to the islet cells and for the dispersal of the secreted hormones to the target organs (1,2). This pancreatic islet angioarchitecture entails a blood perfusion of the pancreatic islets that is 10 times higher than that in the exocrine pancreas and similar to that seen in the renal cortex (ϳ5-7 ml ⅐ min Ϫ1 ⅐ g -1 ) (3-6). However, during the process of isolation and in vitro culture of pancreatic islets preceding transplantation, the islet vasculature dedifferentiates or degenerates (7,8). Therefore, immediately after transplantation, the pancreatic islets are supplied with oxygen and nutrients solely by diffusion from the surrounding tissues. The revascularization process is initiated within a few days, and the islets are generally thought to be fully revascularized by 1 month posttransplantation (9,10). We had previously observed markedly decreased oxygen tension in islets transplanted beneath the renal capsule at 1 month posttransplantation, a decrease that was even more pronounced in diabetic animals (11)....

show abstract

Section: Discussionmentioning

confidence: 53%

Markedly Decreased Oxygen Tension in Transplanted Rat Pancreatic Islets Irrespective of the Implantation Site

Carlsson¹,

Palm²,

Andersson³

et al. 2001

Diabetes

373

303

View full text Add to dashboard Cite

show abstract

“…5A) (158). In order to facilitate the assignment of hypoxic versus normoxic tumors across patient populations, several descriptive parameters of the histogram have been reported, including the frequency of measurements below a given mmHg value, referred to as the hypoxic fraction.…”

Section: Diagnosis Of Tumor Hypoxiamentioning

confidence: 99%

The Clinical Importance of Assessing Tumor Hypoxia: Relationship of Tumor Hypoxia to Prognosis and Therapeutic Opportunities

Walsh

Lebedev

Aten³

et al. 2014

Antioxidants & Redox Signaling

360

317

View full text Add to dashboard Cite

Tumor hypoxia is a well-established biological phenomenon that affects the curability of solid tumors, regardless of treatment modality. Especially for head and neck cancer patients, tumor hypoxia is linked to poor patient outcomes. Given the biological problems associated with tumor hypoxia, the goal for clinicians has been to identify moderately to severely hypoxic tumors for differential treatment strategies. The ''gold standard'' for detecting and characterizing of tumor hypoxia are the invasive polarographic electrodes. Several less invasive hypoxia assessment techniques have also shown promise for hypoxia assessment. The widespread incorporation of hypoxia information in clinical tumor assessment is severely impeded by several factors, including regulatory hurdles and unclear correlation with potential treatment decisions. There is now an acute need for approved diagnostic technologies for determining the hypoxia status of cancer lesions, as it would enable clinical development of personalized, hypoxia-based therapies, which will ultimately improve outcomes. A number of different techniques for assessing tumor hypoxia have evolved to replace polarographic pO 2 measurements for assessing tumor hypoxia. Several of these modalities, either individually or in combination with other imaging techniques, provide functional and physiological information of tumor hypoxia that can significantly improve the course of treatment. The assessment of tumor hypoxia will be valuable to radiation oncologists, surgeons, and biotechnology and pharmaceutical companies who are engaged in developing hypoxia-based therapies or treatment strategies. Antioxid. Redox Signal. 21, 1516-1554.

show abstract

“…Tumor cells maintain a high proliferation rate and consumption of nutrients and oxygen that often overcomes the support capacity of existing local blood vessels. 24 As a result, areas with low oxygen develop in most solid tumors, 25,26 and cells have diverse mechanisms to adjust to hypoxia. Although adaptation to an acute decrease in oxygen levels is mainly mediated by reversible posttranscriptional modifications such as phosphorylation, under chronic deprivation, cells induce the expression of new genes that allow the tumor to adapt to these stressful conditions.…”

Section: Mechanisms Of Gapdh Regulationmentioning

confidence: 99%

Novel roles for GAPDH in cell death and carcinogenesis

2009

View full text Add to dashboard Cite

Growing evidence points to the fact that glucose metabolism has a central role in carcinogenesis. Among the enzymes controlling this energy production pathway, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is of particular interest. Initially identified as a glycolytic enzyme and considered as a housekeeping gene, this enzyme is actually tightly regulated and is involved in numerous cellular functions. Particularly intriguing are recent reports describing GAPDH as a regulator of cell death. However, its role in cell death is unclear; whereas some studies point toward a proapoptotic function, others describe a protective role and suggest its participation in tumor progression. In this study, we highlight recent findings and discuss potential mechanisms through which cells regulate GAPDH to fulfill its diverse functions to influence cell fate.

show abstract

Oxygenation of head and neck tumors

Cited by 155 publications

References 24 publications

Markedly Decreased Oxygen Tension in Transplanted Rat Pancreatic Islets Irrespective of the Implantation Site

Markedly Decreased Oxygen Tension in Transplanted Rat Pancreatic Islets Irrespective of the Implantation Site

The Clinical Importance of Assessing Tumor Hypoxia: Relationship of Tumor Hypoxia to Prognosis and Therapeutic Opportunities

Novel roles for GAPDH in cell death and carcinogenesis

Contact Info

Product

Resources

About