Leonard Che Fru

Understanding the dynamic nature of tumor hypoxia is vital for cancer therapy. The presence of oxygen within a tumor during radiation therapy increases the likelihood of local control. We used a novel interstitial diffuse optical probe to make real-time measurements of blood volume fraction and hemoglobin oxygen saturation within a tumor at a high temporal resolution. This device was initially characterized and benchmarked using a customized vessel designed to control hemoglobin oxygen saturation and blood volume in a solution of blood with different concentrations of an oxygen scavenger, tetrakis (hydroxymethyl) phosphonium chloride. The optical device was found to consistently monitor the changes in oxygen saturation and these changes correlated to the concentration of the oxygen scavenger added. In near-simultaneous measurements of blood volume and oxygen saturation in tumor-bearing mice, the changes in blood volume fraction and oxygen saturation measured with the interstitial diffuse optical probe were benchmarked against photoacoustic imaging system to track and compare temporal dynamics of oxygen saturation and blood volume in a patient-derived xenograft model of hypopharyngeal carcinoma. Positive correlations between our device and photoacoustic imaging in measuring blood volume and oxygen saturation were observed.

PMID:32095273 | PMC:PMC7039661 | DOI:10.1088/2057-1976/ab6e16

At the time of publication, our group had performed short tandem repeat (STR) testing on the SCC22B cell line and believed that had been correctly identified. As part of a recent comprehensive process to confirm the identity of cell lines in use in our lab, we repeated STR testing on all cell lines. These results were compared to the ExPASy Cellosaurus database (http://web.expasy.org/cellosaurus/). One cell line used in this manuscript was a near perfect match for T24 (CVCL_0554), a bladder carcinoma cell line commonly found as a cellular contaminant. Although we are unable to test the exact cells used in this manuscript, we believe that the cells labeled as SCC22B are most likely to actually be T24. The authors believe that neither the results nor the conclusions have been significantly changed on the basis of the specific cell line utilized.

PMID:29873307 | DOI:10.1088/1361-6560/aacaba

Tumor acute hypoxia has a dynamic component that is also, at least partially, coherent. Using blood oxygen level dependent magnetic resonance imaging, we observed coherent oscillations in hemoglobin saturation dynamics in cell line xenograft models of head and neck squamous cell carcinoma. We posit a well-established biochemical nonlinear oscillatory mechanism called the glycolytic oscillator as a potential cause of the coherent oscillations in tumors. These data suggest that metabolic changes within individual tumor cells may affect the local tumor microenvironment including oxygen availability and therefore radiosensitivity. These individual cells can synchronize the oscillations in patches of similar intermediate glucose levels. These alterations have potentially important implications for radiation therapy and are a potential target for optimizing the cancer response to radiation.

PMID:26576743 | PMC:PMC4833657 | DOI:10.1088/0031-9155/60/24/9215