ALDH1A1 confers resistance to RAF/MEK inhibitors in melanoma cells by maintaining stemness phenotype and activating PI3K/AKT signaling

The mitogen-activated protein kinase (MAPK/ERK) pathway is pivotal in controlling the proliferation and survival of melanoma cells. Several mutations, including those in BRAF, exhibit an oncogenic effect leading to increased cellular proliferation. As a result, the combination therapy of a MEK inhibitor with a BRAF inhibitor demonstrated higher efficacy and lower toxicity than BRAF inhibitor alone. This combination has become the preferred standard of care for tumors driven by BRAF mutations. Aldehyde dehydrogenase 1A1 (ALDH1A1) is a known marker of stemness involved in drug resistance in several type of tumors, including melanoma. This study demonstrates that melanoma cells overexpressing ALDH1A1 displayed resistance to vemurafenib and trametinib through the activation of PI3K/AKT signaling instead of MAPK axis. Inhibition of PI3K/AKT signaling partially rescued sensitivity to the drugs. Consistently, pharmacological inhibition of ALDH1A1 activity downregulated the activation of AKT and partially recovered responsiveness to vemurafenib and trametinib. We propose ALDH1A1 as a new potential target for treating melanoma resistant to MAPK/ERK inhibitors.

Scoping Review on Platelets and Tumor Angiogenesis: Do We Need More Evidence or Better Analysis?

Platelets are an active component of the tumor microenvironment (TME), involved in the regulation of multiple tumor processes, including angiogenesis. They are generated rich in angiogenic factors in their granules to actively participate in the hemostatic process by megakaryocytes and further enriched in angiogenic factors by all components of the tumor microenvironment to control the angiogenic process because of their preferential relationship with the endothelial component of vessels. In recent decades, the literature has reported a great deal of evidence on the role of platelets in tumor angiogenesis; however, it is unclear whether the number or mean volume of platelets and/or their content and localization in TME may have clinical relevance in the choice and management of therapy for the cancer patient. In this scoping review, we collected and critically reviewed the scientific evidence supporting a close relationship between platelets, cancer, and angiogenesis. The aim of this work was to define the landscape of platelet-activated angiogenesis in cancer progression and analyze what and how much evidence is present in the last 20 years in the literature at both the preclinical and clinical levels, to answer whether platelets could be a useful determinant for analyzing tumor angiogenesis. In conclusion, this scoping review indicates that there is much evidence, both preclinical and clinical, but in the preclinical context, studies demonstrate the direct involvement of platelets in tumor angiogenesis; in the clinical context the evidence is indirect, though strong, and the indication of how and to what extent platelet content contributes to tumor angiogenesis is lacking. So, do we need more evidence or better analysis? More molecular and quali-quantitative data is needed to translate the results obtained in preclinical studies into the clinical setting. This information about platelets, if correlated with tumor type and its biology, including tumor vasculature, type of angiogenesis, and patient characteristics (age, sex, comorbidities, drug treatments for chronic diseases) could be an important pa- rameter for correlating platelet biology to angiogenesis, for personalizing cancer therapy, and for clinical prognosis.

Fire hazard analysis at Ignalina Nuclear Power Plant

The fire hazard analysis methodology and main results of Ignalina Nuclear Power Plant RBMK-1500 type reactor's systems and rooms with safety elements and also rooms adjacent to main rooms and other fire hazardous rooms are presented. In total this concerns about 2100 rooms in the control area of one Unit, where the fire could influence nuclear safety of the power plant. For this purpose the decision-making computerized system FIRE-INPP was developed. It includes modules for recording necessary information, data processing, analysis and assessment on compliance of rooms at Ignalina NPP with national fire safety requirements and international recommendations regarding fire hazard. Screening algorithms and decision-making module are the basis for the decision-making computerized system, that allows to perform unambiguous, reliable and fast fire hazard analysis and give recommendations to ensure fire safety adequacy.

Environmental safety aspects of the new solid radioactive waste management and storage facility at the Ignalina Nuclear Power Plant

New solid radioactive waste management and interim storage facilities will be constructed for the Ignalina Nuclear Power Plant to support ongoing decommissioning activities, including removal and treatment of operational waste from the existing storage buildings. The paper presents approach and methods that have been used to assess radiological impacts to the general public potentially arising under normal operation and accident conditions and to demonstrate compliance with regulations in force. The assessment of impacts from normal operation includes evaluation of exposure arising from release of airborne radioactive material and from facilities and packages containing radioactive material. In addition, radiological impacts from other nearby operating and planned nuclear facilities are taken into consideration. The assessment of impacts under accident conditions includes evaluation of exposure arising from the selected design and beyond design basis accidents.

Strategy, main stages and progress of the Ignalina Nuclear Power Plant decommissioning

Unit 1 and Unit 2 reactors of the Ignalina Nuclear Power Plant were shutdown in December 31, 2004 and December 31, 2009, respectively. Preliminary and Final Decommissioning Plans for the Ignalina Nuclear Power Plant Units 1 and 2 were prepared, the latter of which was approved by Ministry of Economy in 2005. The main points of Final Decommissioning Plan and the main Decommissioning Projects for the Ignalina Nuclear Power Plant are summarized in this paper. Particular attention is drawn to the spent nuclear fuel and radioactive waste management projects. Preliminary analysis showed that the main mass of equipment to be dismantled is concentrated in reactor buildings (∼39%) and turbine halls (∼37%) and consists from metals of different types (∼83%). From radiological point of view, a major part (∼61%) of contaminated equipment can be classified as very low level radioactive waste.

Radiological and thermal characteristics of CASTOR RBMK-1500 and CONSTOR RBMK-1500 casks for spent nuclear fuel storage at Ignalina Nuclear Power Plant

The main characteristics, such as temperatures of the fuel rod cladding and cask surface, dose rates at the surface and at the some distance for CASTOR RBMK-1500 and CONSTOR RBMK-1500 casks loaded with spent nuclear fuel are presented. These casks are used for an interim dry storage of spent nuclear fuel at Ignalina Nuclear Power Plant. Numerical modeling (calculation of the equivalent dose rates, activities of nuclides, etc.) and experimental measurements of the equivalent dose and gamma spectrum on the cask surface at the dry storage facility were performed for assessment of radiation characteristics. Temperatures were evaluated using only numerical modeling. Rather good agreement between experimentally determined and calculated dose rates for CASTOR RBMK-1500 and CONSTOR RBMK-1500 casks was obtained. Also it was revealed that maximum fuel rod cladding temperature is higher for CONSTOR RBMK-1500 cask, but never exceeds the maximum allowable value. The cask surface temperatures are similar for both cask types.