PhD Scientific Days 2022

Pathology and Oncology III. (Poster discussion will take place in the Aula during the Coffee Break)

Significance of Changes in the Activity of Metabolic Targets in the Development and Resistance of Renal Tumors

Text of the abstract

Introduction
Nowadays, surgical resection (radical or partial nephrectomy) remains the only effective therapy for clinically localized renal cell carcinoma (RCC). Currently, RCC, including clear cell renal cell carcinoma (ccRCC), is generally considered a metabolic disease. Obvious features of renal cell carcinoma are the mutations in signalling pathways involved in metabolic alterations. At present, these metabolic changes are believed to be related to treatment-resistance and therapy-failure.

Aims
Our former studies showed differences in mTOR activity and existing metabolic heterogeneity of ccRCC-s in situ in immunhistochemical staining. Based on these studies, we assume that the metabolic heterogeneity of tissues may be an important components of individual therapy response and various disease progression. In our in vitro and in vivo work we are studying these therapy resistance mechanisms.

Methods
Using in vitro human ccRCC models and various drugs and compounds (chemotherapeutics - cisplatin, vindesine, targeted therapeutics - pazopanib, sorafenib, mTOR and metabolic inhibitors – rapamycin, NVP-BEZ235, BPTES, CB839, ACSS2i, chloroquin etc.). The altered proliferation, viability and multidrug resistance were tested by Alamar Blue, Sulphorhodamine B and calcein assays. Additionally, the metabolic protein expression pattern diffences were analysed by Western Blot, Wes Simple and LC-MS.

Results
We detected significant differences in drug-sensitivity (ED50) in majority of studied treatments. The most interesting result was the extremely high ED50 (>100x) in the A498 (vs. 786-O) cell line for the currently first-line-used multi-tyrosine kinase inhibitor (pazopanib). This difference was not related to increased Pgp expression. The metabolic alterations and metabolic protein expression patterns were also detected - increased mTORC1 activity and individual alterations in mTORC2 and glycolytic activity were shown.

Conclusion
Growing difficulties in clinical management of renal cancers need special efforts to understand the mechanisms of therapy resistance. Studying these mechanisms in cancer models can lead us to find new targets and more effective treatments. We need to confirm our in vitro experiments and further study the molecular mechanisms, potential new targets of developing resistance.

Funding: NKFI-FK-128404, 41966-3/DIDIT/2022