Introduction Despite the high efficacy of Radiation therapy (RT) to treat breast carcinoma (BC), the problem of radioresistance and tumour recurrence is still not solved. It is believed that radioresistance can be associated with the presence of a subpopulation of cells, called ‘cancer stem cells’ (CSCs). However, it is still unclear which molecular profiling of BC cells should be used as a predictor of poor clinical outcome after RT. Therefore, the main aim of this study was to determine the molecular phenotype of BC cells with acquired radiation resistance and stemness properties. Material and methods Two carcinoma cell lines, MDA-MB-231 and T47D, representing the most common molecular subtypes of breast cancer (triple negative and luminal A) were repetitively irradiated at a total dose of 100 Gy, and finally, radioresistant (RR) BC cell lines were obtained. To confirm the radioresistant phenotype of the newly received RR cells, their radiation sensitivities were compared with those in their parental counterparts using a clonogenic survival assay. FACS analysis was performed to detect the content of BC stem cell markers CD44 + /CD24 - . Additionally, a sphere forming assay was performed to detect the stemness abilities of the investigated breast carcinoma cells. Parental and RR cells were examined for their protein patterns using nano-LC mass spectrometry followed by PathwayStudio-based computational analysis. Western Blot, FACS, and metabolic patterns of parental and RR cells were performed to prove the proteomic results. Results and discussions Newly obtained RR breast carcinoma cell lines possess a prominent radiation resistance accompanied by enhanced sphere forming abilities and increased number of CD44 + /CD24 - cells in comparison with parental cells. Proteome analysis has shown an up-regulation of proteins involved in different molecular pathways protecting carcinoma cells from ionising radiation. Molecular pathways regulating DNA repair processes, cell cycle distribution and cell death development, metabolic activities, cell differentiation/dedifferentiation, have demonstrated the most pronounced connectivities with radiation resistance. Conclusion Radioresistant BC cells demonstrate their aggressive behaviour through changed metabolic properties and activation of pro-survival mechanisms associated with affected therapy response.
Abstract Background Metastatic progression of breast cancer is still a challenge in clinical oncology. Therefore, an elucidation how carcinoma cells belonging to different breast cancer subtypes realize their metastatic capacities is needed. The aim of this study was to elucidate a similarity of activated molecular pathways underlying an enhancement of invasiveness of carcinoma cells belonging to different breast carcinoma subtypes. Materials and methods In order to reach this aim, parental and invasive (INV) MDA-MB-231 (triple-negative), T47D (hormone receptor-positive), and Au565 (Her2-positive) breast carcinoma cells were used and their molecular phenotypes were compared using a proteomic approach. Results Independently from breast cancer subtypes, INV cells have demonstrated fibroblast-like morphology accompanied by enhancement of invasive and migratory capacities, increased expression of cancer stem cell markers, and delayed tumor growth in in vivo animal models. However, the global proteomic analysis has highlighted that INV cells were different in protein expressions from the parental cells, and Her2-positive Au565-INV cells showed the most pronounced molecular differences compared to the triple-negative MDA-MB-231-INV and hormone receptor-positive T47D-INV cells. Although Au565-INV breast carcinoma cells possessed the highest number of deregulated proteins, they had the lowest overlapping in proteins commonly expressed in MDA-MB-231-INV and T47D-INV cells. Conclusions We can conclude that hormone receptor-positive cells with increased invasiveness acquire the molecular characteristics of triple-negative breast cancer cells, whereas Her2-positive INV cells specifically changed their own molecular phenotype with very limited partaking in the involved pathways found in the MDA-MB-231-INV and T47D-INV cells. Since hormone receptor-positive invasive cells share their molecular properties with triple-negative breast cancer cells, we assume that these types of metastatic disease can be treated rather equally with an option to add anti-hormonal agents. In contrast, Her2-positive metastasis should be carefully evaluated for more effective therapeutic approaches which are distinct from the triple-negative and hormone-positive metastatic breast cancers.
Purpose/Objective:Reproducible patient positioning remains one of the major challenges in modern radiation therapy. Recently, optical surface scanners have been introduced into clinical practice in addition to well-established positioning systems, such as room laser and skin marks. The aim of this prospective study was to evaluate setup errors of the optical surface scanner Catalyst HD (C-RAD AB) in different anatomic regions. Material/Methods:Between October 2016 and June 2017 a total of 1902 treatment sessions in 110 patients were evaluated. The workflow of this study included conventional setup procedures using laser-based positioning with skin marks and an additional registration of the 3-dimensional (3D) deviations detected by the Catalyst system. The deviations of the surface-based method were then compared to the corrections of cone beam computed tomography alignment which was considered as gold standard. A practical Catalyst setup error was calculated between the translational deviations of the surface scanner and the laser positioning. Two one-sided t tests for equivalence were used for statistical analysis. Results:Data analysis revealed total deviations of 0.09 mm ± 2.03 mm for the lateral axis, 0.07 mm ± 3.21 mm for the longitudinal axis, and 0.44 mm ± 3.08 mm vertical axis for the Catalyst system, compared to −0.06 ± 3.54 mm lateral, 0.53 ± 3.47 mm longitudinal, and 0.19 ± 3.49 mm vertical for the laser positioning compared to cone beam computed tomography. The lowest positional deviations were found in the cranial region, and larger deviations occurred in the thoracic and abdominal sites. A statistical comparison using 2 one-sided t tests showed a general concordance of the 2 methods (P ≤ 0.036), excluding the vertical direction of the abdominal region (P = 0.198). Conclusion:The optical surface scanner Catalyst HD is a reliable and feasible patient positioning system without any additional radiation exposure. From the head to the thoracic and abdominal region, a decrease in accuracy was observed within a comparable range for Catalyst and laser-assisted positioning.
