Abstract 3112: Metabolic hallmarks of rare renal cell carcinoma patient-derived xenograft models
Authors: Ozambela Manuel , Pieretti Alberto , Gonzalez Graciela M. Nogueras , Maity Tapati , Wang Lei , De La Cerda Carolyn , Alonzo Breanna , Segarra Luis , Alaniz Angelita , Rao Priya , Tannir Nizar , Karam Jose A. , Wood Christopher G. , Msaouel Pavlos , Zacharias Niki M. 
Published: June 2022

Abstract
Renal medullary carcinoma (RMC) and fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) are rare but highly aggressive malignancies that are often refractory to the therapies used for the more common RCCs. FH-deficient RCC most often occurs in individuals with hereditary leiomyomatosis and renal cell carcinoma syndrome (HLRCC) and is characterized by loss of FH activity, a key metabolic enzyme. Bevacizumab plus erlotinib (B+E) is a preferred first-line therapy for FH-deficient RCC. RMC is characterized by loss of SMARCB1, which is involved in ATP-dependent chromatin remodeling. Platinum-based chemotherapy consisting of either cisplatin or carboplatin plus paclitaxel is the preferred first-line therapy for RMC. We developed patient-derived xenograft (PDX) models of tumors exposed to the commonly used first-line therapies to allow functional characterization of the metabolic hallmarks of treatment-experienced RMC and FH-deficient RCC. Methods: Resected tumor tissue was immediately implanted into NSG male and female mice. After tumor engraftment, animals were euthanized, and the tumor tissue implanted into another set of NSG mice. PDX tissues were confirmed to be genetically identical to the original patient tissue by short tandem repeat analysis. Histology was confirmed to be identical between original patient tumor and PDX by a trained clinical pathologist. Four tumors from each PDX model and four normal human kidney tissue samples were analyzed using reverse phase protein array (RPPA). Expression of proteins shown to be highly expressed by RPPA were further validated by Western blots. Results: We successfully generated one PDX model for RMC and one for FH-deficient RCC, respectively. The RMC model was generated from a 28-year old male with sickle cell trait, who had previously received cisplatin plus paclitaxel followed carboplatin plus paclitaxel. His lesion was characterized as ypT3apN1pMx and histology was consistent with RMC. The FH-deficient RCC model was generated from a 24-year-old female with HLRCC, who had been previously treated with B+E. Her lesion was characterized as pT3apN1pM1 and histology consistent with FH-deficient RCC. Germline testing revealed a R233H pathogenic mutation in the FH gene. RPPA revealed higher expression of hexokinase II (10x HLRCC, 16x RMC), lactate dehydrogenase A (27x HLRCC, 17x RMC), and glutaminase (4x HLRCC) in PDX tissue compared to normal kidney tissue. Western blots confirmed higher expression of glutaminase 1 in both HLRCC and RMC compared to normal kidney. Furthermore, we observed substantially higher hypoxia inducible factor 2α (HIF2α) protein expression in PDX tissue from FH-deficient RCC compared to RMC PDX tumors and normal kidney. Conclusions: Our study revealed distinct metabolic features in PDX models of FH-deficient RCC following treatment with B+E, and of platinum-experienced RMC, these differences may confer targetable vulnerabilities.
Citation Format: Manuel Ozambela, Alberto Pieretti, Graciela M. Nogueras Gonzalez, Tapati Maity, Lei Wang, Carolyn De La Cerda, Breanna Alonzo, Luis Segarra, Angelita Alaniz, Priya Rao, Nizar Tannir, Jose A. Karam, Christopher G. Wood, Pavlos Msaouel, Niki M. Zacharias. Metabolic hallmarks of rare renal cell carcinoma patient-derived xenograft models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3112.