Evaluation of the Effects of Prostate Radiation Therapy on Occludin Expression and Ultrasonography Characteristics of the Bladder

Dose- and Segment-Dependent Disturbance of Rat Gut by Ionizing Radiation: Impact of Tight Junction Proteins

The damaging effect of ionizing radiation (IR) exposure results in the disturbance of the gut natural barrier, followed by the development of severe gastrointestinal injury. However, the dose and application segment are known to determine the effects of IR. In this study, we demonstrated the dose- and segment-specificity of tight junction (TJ) alteration in IR-induced gastrointestinal injury in rats. Male Wistar rats were subjected to a total-body X-ray irradiation at doses of 2 or 10 Gy. Isolated jejunum and colon segments were tested in an Ussing chamber 72 h after exposure. In the jejunum, 10-Gy IR dramatically altered transepithelial resistance, short-circuit current and permeability for sodium fluorescein. These changes were accompanied by severe disturbance of histological structure and total rearrangement of TJ content (increased content of claudin-1, -2, -3 and -4; multidirectional changes in tricellulin and occludin). In the colon of 10-Gy irradiated rats, lesions of barrier and transport functions were less pronounced, with only claudin-2 and -4 altered among TJ proteins. The 2-Gy IR did not change electrophysiological characteristics or permeability in the colon or jejunum, although slight alterations in jejunum histology were noted, emphasized with claudin-3 increase. Considering that TJ proteins are critical for maintaining epithelial barrier integrity, these findings may have implications for countermeasures in gastrointestinal acute radiation injury.

Dosimetric Comparison and TCP-NTCP Modeling for Lung, Heart, Left Anterior Descending, and Right Coronary Artery in Left-sided Breast Cancer Conventional and Hypofractionated Radiotherapy

Background: The aim of this study was to evaluate the dose distribution, as well as tumor control probability (TCP) and normal tissue complications probability (NTCP) models for females with left-sided breast cancer for 3D-CRT, 6, and 9 fields intensity modulated radiotherapy (IMRT) and hypofractionated tangential plans. Methods: Eighty females with left-sided breast cancer (N1T1 – N3T3) were included in this study. The patients were divided into breast conserving surgery (BCS) (n= 50) and mastectomy (n=30) patients. CT simulation images of the patients were imported on the treatment planning software (TiGRT, LinaTech, China) and the tangential treatment plans of the mentioned methods were done, using TPS. Dose assessments were performed, employing the TPS, and TCP-NTCP models of stated modalities were done, using Poisson linear-quadatric (PLQ) and Lyman-Kutcher-Burman (LKB) models on MATLAB and R software. Results: For the BCS and post-mastectomy patients, 6FIMRT imposed lower doses to ipsilateral lung, heart, LAD, RCA, and contralateral breast compared to 9FIMRT, hypofractionated RT, and 3D-CRT (P < 0.005). Also, the NTCPs of the mentioned normal tissues for 6FIMRT were lower than other methods for both BCS and post-mastectomy groups. Moreover, it was found that the V20Gy for Ipsilateral lung and the V25Gy for heart, LAD, and RCA of 6FIMRT, 9FIMRT, and hypofractionated RT was significantly lower compared to 3D-CRT (P < 0.005) for both BCS and mastectomy groups, while there were no significant differences among them for the 6FIMRT and 9FIMRT with hypofractionated RT (P > 0.005). The TCP values of 9FIMRT, 6FIMRT, and hypofractionated RT were not considerably different; however, the TCP values of 3D-CRT were lower compared to other stated methods. Conclusions: 6FIMRT is a suitable choice for RT of patients with left-sided breast cancer compared to other mentioned modalities, as a result of providing adequate PTV dose coverage and TCPs. Also, it may impose lower doses and NTCPs for OARs. Hypofractionated RT is a good alternative to reduce treatment time for patients with breast cancer.

Inhibition of Cathepsin S Restores TGF-β-induced Epithelial-to-mesenchymal Transition and Tight Junction Turnover in Glioblastoma Cells

Background: Invasive growth is one of the most typical features of aggressive types of malignant cancer, including glioblastoma. Lysosomal cysteine protease-cathepsin S (CTSS), has been reported to be involved in invasive growth and distant metastasis of cancer cells. However, the underlying mechanisms remained elusive. Methods: U87 and U251 human glioblastoma cell lines were applied in this study. Cell migration and invasion ability were measured by wound healing assay and transwell assay. Western blot was employed to detect the expression levels of proteins. Immunofluorescence assays of cells and tissues were used to visualize the localization and expression of proteins. The SPSS software was used for statistical analysis. Results: Our results showed that the high expression of CTSS was link with the grades of glioma tissues. The CTSS inhibitor-Z-FL-COCHO (ZFL), could attenuate TGF-β-induced invasive growth as proven by wound healing and transwell assays. Furthermore, inhibition of CTSS could reverse TGF-β-induced epithelial-to-mesenchymal transition (EMT) and restore TGF-β-triggered tight junction proteins turnover, thus decreasing glioblastoma cell mobility. We also observed that TGF-β could change the morphology of glioblastoma cells, redistribute intermediate-filament, vimentin, which was highly relevant to mesenchymal type cells and enhanced mobility. However, inhibition of CTSS could significantly restore this transformation. Our results proved that PI3K/AKT/mTOR pathway was significantly suppressed in the TGF-β+ZFL (CTSS inhibitor) groups, and AKT activator-SC79, could reverse the anti-invasion effect of CTSS, indicating an important role of PI3K/AKT/mTOR pathway in this process. Conclusion: Z-FL-COCHO (ZFL), a CTSS inhibitor, could reverse TGF-β-induced EMT and change of tight junction proteins via PI3K/AKT/mTOR pathway.