Hypoxia alters the response of ovarian cancer cells to the mitomycin C-drug

Aleksandra Gawrylak^1,2*Klaudia Brodaczewska¹Roksana Iwanicka-Nowicka^3,4Marta Koblowska^3,4Agnieszka Synowiec¹Lubomir Bodnar^5,6Cezary Adam Szczylik⁷Bogdan Lesyng⁸Rafał Stec⁹Claudine Kieda^1,10

• ¹Laboratory of Molecular Oncology and Innovative Therapies, Military Institute of Medicine (Poland), Warsaw, Poland
• ²Department of Immunology, Institute of Functional Biology and Ecology, Faculty of Biology, University of Warsaw, Warsaw, Poland
• ³Laboratory of Systems Biology, Faculty of Biology, University of Warsaw, Warsaw, Poland
• ⁴Laboratory of Microarray Analysis, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
• ⁵Faculty of Medical Sciences and Health Sciences, University of Natural Sciences and Humanities, Siedlce, Poland
• ⁶Department of Clinical Oncology and Radiotherapy, St. John Paul II Mazovia Regional Hospital in Siedlce, Siedlce, Poland
• ⁷Department of Oncology, Centre of Postgraduate Medical Education, European Health Centre, Warsaw, Poland
• ⁸Division of Biophysics and Center for Machine Learning, Faculty of Physics, University of Warsaw, Warsaw, Poland
• ⁹Oncology Department, Medical University of Warsaw, Warsaw, Poland
• ¹⁰Center for Molecular Biophysics UPR 4301 CNRS, Orleans, France

Introduction: Discrepancies between preclinical tests and clinical results raise serious concern about the appropriateness of the methods. Namely, the cell biology approaches neglect fundamental physical parameters that although they reflect the in vivo conditions. Oxygen availability is critical for the cell reactions and thus the lack of consideration of hypoxia as main regulator of tumor microenvironment (TME), leads to misinterpreted data in with consequences forview of translational applications. Here, we show mitomycin C (MMC), an antineoplastic antibiotic, yet rarely used in ovarian cancer (OC) treatment despite its potential efficacy, as an example of treatment that should be revisited in the light of microenvironmental biological conditions when in vitro testing is undertaken.To evaluate the effects of MMC and oxygen tension (pO2) on OC cells (SKOV3), HTA 2.0 microarrays were used and demonstrated that hypoxia, as well as MMC, induced transcriptomic changes in OC cells. Their combination particularly emphasized the effect of pO2modification on MMC activity. The most significant data were verified in three other OC cell lines: TOV112D, ES-2, A2780.In normoxia, MMC mostly affected several pathways associated with ribosome-related processes, while extracellular matrix (ECM) modifications occurred when used in hypoxia. The most significantly upregulated gene upon hypoxia-MMC treatment was MMP1, regulated by both MMC and hypoxia. Low pO2 during MMC treatment allowed the identification of important regulators, such as SPP1 and the corresponding processes, including cholesterol biosynthesis.Hypoxia modulated the effects of MMC on OC cells and identified genes that should be further targeted to enhance the effectiveness of MMC treatment.