PhD Scientific Days 2021

PO_I_P: Pathology and Oncology I. Posters

Studies Finding Additional Therapeutic Options in Clear Cell Renal Cell Carcinomas

Text of the abstract

Today, surgery is the only curative approach of localised clear cell renal cell carcinoma (ccRCC). The recently applied promising targeted therapies have few succes; medical treatment of the disease remains palliative in advanced or recurrent cases. This may be due to changes in intracellular signal transmission or different metabolic adaptation mechanisms.

In previous studies we characterised the mTOR activity and metabolic enzyme expression of ccRCC-s in situ in immunohistochemical analyses. Tissue heterogeneity highlighted that differences in therapeutic responses could be a consequence of individual metabolic changes. In our work we aim to model these changes in vitro and elucidate the resistance mechanisms associated with metabolic adaptation.

In our in vitro studies two RCC cell lines (A498, 786-O) were treated with conventional chemotherapeutic agents (cisplatin, vindesine), targeted therapeutic agents (pazopanib, sorafenib), different metabolic (BPTES, CB839, chloroquin, etc.) and mTOR (PP242) inhibitors. The differences in sensitivity were characterized with cell proliferation assays (AB, SRB). The function of Pgp known in the background of multidrug resistance was analysed by FACS. The basic metabolic characteristics (expression of metabolic enzymes and metabolite concentration) of the cell lines were also examined with using WES Simple, WB and LC-MS techniques.

Significant differences in drug-sensitivity were detected; the calculated ED50 in the A498 cell line for the currently first-line-used multi-tyrosine kinase inhibitor (pazopanib) was 100-fold higher than in 786-O without detectable Pgp function. Further differences were confirmed by LC-MS and WES Simple analytical methods: the two carcinoma cell lines showed increased mTOR activity; additionally mTORC1 preference in A498 and high glycolitic activity in 786-O cells were also observed.

The measured differences in drug-sensitivity, metabolite concentration and protein expression in the two cell lines can help us to understand the mechanisms of resistance, which is a growing problem of recent therapies. Characterizing the effects of combining metabolic inhibitors with current treatments, as well as understanding the mechanisms of resistance in vitro and in vivo in further studies can lead us to develop new targets and more effective treatments.

NKFI-FK-128404, STIA-KFI2020, ÚNKP_19_I-SE-80

University and Doctoral School

Semmelweis University, Doctoral School of Pathological Sciences