Bisphenol A (BPA) is commonly present in plastics used for food storage and preservation. The release of BPA from these products results in a permanent human exposition to BPA; however, the quality an Show more
Bisphenol A (BPA) is commonly present in plastics used for food storage and preservation. The release of BPA from these products results in a permanent human exposition to BPA; however, the quality and quantity of BPA adverse effects remain a matter of controversy. The common presence of BPA in the human environment and the controversies concerning the relations of human exposition to BPA and cancer incidence justify the research on the interactions between BPA and pro-metastatic signaling in cancer cells. Here, we describe a novel BPA-reactive signaling axis that induces the epithelial-mesenchymal transition (EMT) in lung adenocarcinoma A549 cells. BPA exerted negligible effects on their properties in a wide range of concentrations (10 nM - 100 nM), whereas it considerably induced A549 invasiveness at high concentrations (10 μM). The BPA-induced EMT was illustrated by morphologic changes, E/N-cadherin switch and vimentin/Snail-1/connexin(Cx)43 up-regulation in A549 populations. It was followed by enhancement of A549 drug-resistance. Corresponding effects of BPA were observed in prostate cancer cell populations. Concomitantly, we observed increased levels and perinuclear accumulation of estrogen-related receptor gamma (ERRγ) in BPA-treated cells, its interactions with Cx43/Snail-1, and the corresponding effects of phenol red on A549 cells. Collectively, these data identify a novel, pro-metastatic Snail-1/Cx43/ERRγ signaling pathway. Its reactivity to BPA underlies the induction of cancer cells' invasiveness in the presence of high BPA concentrations in vitro. Thus, the chronic exposition of cancer cells to extrinsic and intrinsic BPA should be considered as a potential obstacle in a cancer therapy. Show less
Chronic lymphocytic leukemia (CLL) remains incurable; therefore searching for new therapeutic strategies in this disease is necessary. An important mechanism of tumor development is neoangiogenesis. A Show more
Chronic lymphocytic leukemia (CLL) remains incurable; therefore searching for new therapeutic strategies in this disease is necessary. An important mechanism of tumor development is neoangiogenesis. A potent antiangiogenic factor, bevacizumab (Avastin, AVA), has been poorly explored in CLL so far. In the current study we assessed cytotoxic activity of AVA alone or in combinations with drugs routinely used in this disease. Cells isolated from 60 CLL patients were treated with AVA alone or in combination with anti-CD20 monoclonal antibody (MoAb), rituximab (RIT), anti-CD52 MoAb, alemtuzumab (ALT), 2-CdA (2-chlorodeoxyadenosine), FA (fludarabine), MAF (mafosfamide) or RAPA (rapamycin). Cytotoxicity was assessed by propidium iodide staining. Apoptosis was evaluated using annexin-V and TUNEL assays. Additionally, a drop of mitochondrial potential (DYm) as well as expression of apoptosis-regulating proteins Bax, Bak, Bid, Bad, Bcl-2, Mcl-2, XIAP, FLIP, Akt and Bcl-2-A1 were determined by flow cytometry. At the dose of 40 μg/ml, after 48 hours of incubation, AVA induced significant cytotoxicity against CLL cells. The drug triggered apoptosis, with activation of caspase-3 and -9, but not caspase-8, along with a drop of DYm. Incubation with AVA induced significant overexpression of proapoptotic Bak and Bad as well as downregulation of antiapoptotic Mcl-2 and Akt proteins. Combination of AVA with RIT, ALT or RAPA significantly increased cytotoxicity when compared with the effects of single drugs. In conclusion, this is the first report showing proapoptotic activity of AVA against CLL cells. Combination of AVA with RIT, ALT or RAPA may be a promising therapeutic strategy, which requires confirmation in further studies. Show less