Thesis presented February 20, 2023

Abstract:
Clear cell Renal Cell Carcinoma (ccRCC) is the most common kidney cancer, often asymptomatic and therefore discovered at the metastatic state (mRCC) in over 30% of patients. Current treatments for mRCC consist of kinase-targeted therapies (TKIs) and immunotherapies, alone or in combination, but their effectiveness remains limited. This is particularly true due to treatment resistance and because TKIs mostly target the same proteins, limiting the options in case of relapse. Furthermore, these treatments have been developed using cell-based models that are not representative of the tumor heterogeneity and clonal evolution characteristic of metastatic tumors.
To address this problem, several recent works have described the generation and characterization of patient-derived ccRCC tumoroids and it is established that these models more accurately recapitulate tumor characteristics, making them an excellent avatar for screening and as predictive model for personalized medicine. We further decided to generate a new CRCC tumoroid model from mouse and patient tumors, with a scaffold-free method that was never used for this cancer. We demonstrated that our tumoroids were representative of inter- and intra-tumor heterogeneity, and that they reproduced the major characteristics of the tumors from which they were derived. In parallel, we developed a novel combinational kinase targeted therapy based on synthetic lethality, targeting novel proteins never studied in ccRCC. A high-throughput screen allowed us to identify the kinases CK2 and ATM as therapeutic targets. We found that their combined inhibition induced synthetic lethality in spheroids of ccRCC cell lines, in tumoroids, in patient tumor tissue slices and in vivo in mouse renal cancer xenografts. Furthermore, mechanistic studies revealed that the combination induced apoptosis in a HIF-2α (Hypoxia Inducible Factor-2α) and ROS (Reactive Oxygen Species) dependent manner, giving a new therapeutic option for patients with mRCC.
To go further, we decided to design a medical device with the aim of predicting the treatment response and metastatic potential of patients' tumors. A tumor niche was designed containing a hydrogel in which we place our tumor models of varying complexity (spheroids, tumoroids, tissue slices). We have shown that this hydrogel seems to be adapted to discriminate tumors according to their invasive potential. On the other hand, we have developed different metastatic niches in order to evaluate the tropism of cancer cells for a particular organ, and we are now focusing on the design of a bone niche. Ultimately, these two niches will be combined in a microfluidic chip to study the ability of tumor cells to invade their environment and colonize a new organ. Furthermore, our goal is to use this device to evaluate the anti-metastatic capacity of our inhibitors as well as other clinical and experimental treatments.

Keywords:
CRCC, kidney cancer, tumoroid, CK2, ATM, apoptosis, ROS

On-line thesis. ​