Study On Evaluation The Correlation Between The Expression Level Of HIF In Clear Cell Renal Cell Carcinoma And R2*Values In BOLD-MRI

Purpose:To evaluate the correlation between R2*values of various pathological grade in clearcell renal cell carcinoma (CRCC) and the expression levels of intratumoral hypoxiainducible factors (HIF-1α、HIF-2α).Materials and Methods:Blood oxygen-level dependent MRI images and the expression levels of HIF-1αandHIF-2α of26patients with CRCC, who all underwent sugical operations and wereconfirmed by pathological examinations. All tumors were classified according to Furhmancriterion and then were devided into low-grade and high-grade group. R2*values of thetumor parechyma and bilateral renal cortex and medulla were measured. The differences ofR2*values among CRCC grade and between low-and high-grade CRCCs were evaluated.Receiver operating characteristic curves were drawn to establish the cut-off point forR2*values. The differences of the expression levels of HIF-1αand HIF-2αbetween low-and high-grade CRCCs were compared. Pearson correlation coefficient was used toevaluate the correlations between R2*values of CRCCs and R2*values of bilateral renalcortex and medulla, serum creatinine and the positive expression level of HIF-α.Results:Low-grade group (Grade Ⅰ+Ⅱ) contains17cases and high-grade group (GradeⅢ+Ⅳ) contains9cases. Significant different among tumor grades （P＜0.005）. R2*values of high-grade tumors were significantly higher than those of low-grade tumors. Thepositive expression levels in high-grade tumors were higher than those in low-grade tumors (P＜0.05). R2*values of CRCCs positively correlated with tumor grade （P＜0.005）andthe expression levels of HIF-2α, not with R2*values of bilateral renal cortex and medulla,serum creatinine.Conclusion:R2*value can be used as a non-invasive index to evalute CRCC grades and predictthe expression level of HIF-2α in CRCC.