title: Oxidative Stress Resistance in Metastatic Prostate Cancer: Renewal by Self-Eating.
abstract: Resistant cancer phenotype is a key obstacle in the successful therapy of prostate cancer. The primary aim of our study was to explore resistance mechanisms in the advanced type of prostate cancer cells (PC-3) and to clarify the role of autophagy in these processes. We performed time-lapse experiment (48 hours) with ROS generating plumbagin by using multimodal holographic microscope. Furthermore, we also performed the flow-cytometric analysis and the qRT-PCR gene expression analysis at 12 selected time points. TEM and confocal microscopy were used to verify the results. We found out that autophagy (namely mitophagy) is an important resistance mechanism. The major ROS producing mitochondria were coated by an autophagic membrane derived from endoplasmic reticulum and degraded. According to our results, increasing ROS resistance may be also accompanied by increased average cell size and polyploidization, which seems to be key resistance mechanism when connected with an escape from senescence. Many different types of cell-cell interactions were recorded including entosis, vesicular transfer, eating of dead or dying cells, and engulfment and cannibalism of living cells. Entosis was disclosed as a possible mechanism of polyploidization and enabled the long-term survival of cancer cells. Significantly reduced cell motility was found after the plumbagin treatment. We also found an extensive induction of pluripotency genes expression (NANOG, SOX2, and POU5F1) at the time-point of 20 hours. We suppose, that overexpression of pluripotency genes in the portion of prostate tumour cell population exposed to ROS leads to higher developmental plasticity and capability to faster respond to changes in the extracellular environment that could ultimately lead to an alteration of cell fate.
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University / Kamenice 5, CZ-625 00, Brno, Czech Republic.|Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00, Brno, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Balvan
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University / Kamenice 5, CZ-625 00, Brno, Czech Republic.|Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00, Brno, Czech Republic.
authors.forename: Jaromir
authors.initials: J
authors.lastname: Gumulec
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University / Kamenice 5, CZ-625 00, Brno, Czech Republic.|Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00, Brno, Czech Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Raudenska
authors.affiliation: Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00, Brno, Czech Republic.|TESCAN Brno, s.r.o., Brno, Czech Republic.
authors.forename: Aneta
authors.initials: A
authors.lastname: Krizova
authors.affiliation: Department of Physiology, Faculty of Medicine, Masaryk University / Kamenice 5, CZ-625 00, Brno, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Stepka
authors.affiliation: Department of Physiology, Faculty of Medicine, Masaryk University / Kamenice 5, CZ-625 00, Brno, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Babula
authors.affiliation: Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00, Brno, Czech Republic.|Department of Chemistry and Biochemistry, Mendel University in Brno / Zemedelska 1, CZ-613 00, Brno, Czech Republic.
authors.forename: Rene
authors.initials: R
authors.lastname: Kizek
authors.affiliation: Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00, Brno, Czech Republic.|Department of Chemistry and Biochemistry, Mendel University in Brno / Zemedelska 1, CZ-613 00, Brno, Czech Republic.
authors.forename: Vojtech
authors.initials: V
authors.lastname: Adam
authors.affiliation: Department of Pathological Physiology, Faculty of Medicine, Masaryk University / Kamenice 5, CZ-625 00, Brno, Czech Republic.
authors.forename: Michal
authors.initials: M
authors.lastname: Masarik
mesh_terms: D001343:Autophagy / Q000187:drug effects; D002450:Cell Communication / Q000187:drug effects; D045744:Cell Line, Tumor; D000066673:Cell Self Renewal / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D057691:Entosis / Q000187:drug effects; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D008297:Male; D063306:Mitophagy / Q000187:drug effects; D009285:Naphthoquinones / Q000494:pharmacology; D009362:Neoplasm Metastasis; D018384:Oxidative Stress / Q000187:drug effects; D025341:Principal Component Analysis; D011471:Prostatic Neoplasms / Q000235:genetics / Q000473:pathology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D059008:Time-Lapse Imaging
chemical_list: D009285:Naphthoquinones; D017382:Reactive Oxygen Species; C014758:plumbagin