Abstract

Dynamic contrast-enhanced MRI to predict intratumoral molecular heterogeneity in clear cell renal cell carcinoma.

Author
person Durga Udayakumar University of Texas Southwestern, Dallas, TX info_outline Durga Udayakumar, Ze Zhang, Durgesh Dwivedi, Yin Xi, Tao Wang, Payal Kapur, Qurratulain Yousuf, Allison Joyce, Asghar Hajibeiji, Michael Fulkerson, Alberto Diaz de Leon, Matthew Lewis, Ananth J Madhuranthakam, Jeffrey A Cadeddu, Aditya Bagrodia, Vitaly Margulis, James Brugarolas, Ivan Pedrosa
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Authors person Durga Udayakumar University of Texas Southwestern, Dallas, TX info_outline Durga Udayakumar, Ze Zhang, Durgesh Dwivedi, Yin Xi, Tao Wang, Payal Kapur, Qurratulain Yousuf, Allison Joyce, Asghar Hajibeiji, Michael Fulkerson, Alberto Diaz de Leon, Matthew Lewis, Ananth J Madhuranthakam, Jeffrey A Cadeddu, Aditya Bagrodia, Vitaly Margulis, James Brugarolas, Ivan Pedrosa Organizations University of Texas Southwestern, Dallas, TX, UT Southwestern Medical Center, Dallas, TX, University of Texas Southwestern Medical Center, Dallas, TX, The University of Texas Southwestern Medical Center, Dallas, TX Abstract Disclosures Research Funding U.S. National Institutes of Health Background: Mutation/inactivation of VHL in clear cell renal cell carcinoma (ccRCC) leads to upregulation of hypoxia inducible factors ( HIFs ) and angiogenesis. However, ccRCC is characterized by high intra-tumor heterogeneity (ITH). Random small samples such as those in percutaneous biopsies are likely limited for characterization of molecular alterations in heterogeneous ccRCCs. We hypothesize that whole-tumor dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) is useful to noninvasively identify ITH in ccRCC. Methods: This IRB-approved, prospective, HIPAA-compliant study, included 62 ccRCCs. 3T DCE MRI was obtained prior to nephrectomy. Surgical specimens were sectioned to match MRI acquisition plane. 182 snap frozen samples (49 tumors) and adjacent uninvolved renal parenchyma (URP) were collected. RNA isolations, cDNA library preparation and mRNA sequencing were performed using standard protocols. RNA expression in 81 tumor samples were correlated (Spearman ranked) with % enhancement in a region of interest (ROI) drawn in the same location of the tumor on pre- and 3 different post-contrast DCE MRI phases. Gene function overrepresentation (OR) analyses were done on top positively and negatively correlated genes. False discovery rate (FDR) < 0.1 was considered statistically significant. Results: Principal component analysis of > 20,000 genes indicated distinct gene expression in tumors from URP. Unsupervised clustering showed enrichment of ccA samples (better prognosis) compared to ccB samples (worse prognosis). Importantly, ccA and ccB samples coexisted in 25% of tumors. DCE-MRI % enhancement correlated with expression of > 300 genes (p < 0.003, FDR < 0.1). OR analyses placed angiogenic pathway gene processes and the immune/inflammatory response processes within the top 5 positively- and negatively-correlated gene functions, respectively. HIF2 target genes correlated positively with % enhancement. Conclusions: DCE MRI detects specific molecular signatures and may help overcome the challenges of ITH in ccRCC. Further research is needed to explore the potential role of DCE MRI to assess response to antiangiogenic and immune-based therapies.