Ferroptosis Inducers as Promising Radiosensitizer Agents in Cancer Radiotherapy.

Radiotherapy (RT) failure has historically been mostly attributed to radioresistance. Ferroptosis is a type of controlled cell death that depends on iron and is caused by polyunsaturated fatty acid peroxidative damage. Utilizing a ferroptosis inducer may be a successful tactic for preventing tumor growth and radiotherapy-induced cell death. A regulated form of cell death known as ferroptosis is caused by the peroxidation of phospholipids containing polyunsaturated fatty acids in an iron-dependent manner (PUFA-PLs). The ferroptosis pathway has a number of important regulators. By regulating the formation of PUFA-PLs, the important lipid metabolism enzyme ACSL4 promotes ferroptosis, whereas SLC7A11 and (glutathione peroxidase 4) GPX4 prevent ferroptosis. In addition to introducing the ferroptosis inducer chemicals that have recently been demonstrated to have a radiosensitizer effect, this review highlights the function and methods by which ferroptosis contributes to RT-induced cell death and tumor suppression in vitro and in vivo.

Etodolac Enhances the Radiosensitivity of Irradiated HT-29 Human Colorectal Cancer Cells.

BACKGROUND: Radioresistance is found to be the main therapeutic restriction in colorectal radiation therapy. The aim of this study was to investigate the synergistic effect of Etodolac (ET) and ionizing radiation on human colorectal cancer cells. METHODS: Pretreated HT-29 cells with ET were exposed to ionizing radiation. The radiosensitizing effect of ET was evaluated using MTT, flow cytometry, and clonogenic assay. The amount of nitrite oxide (NO) in irradiated cells was also measured with the Griess reagent. RESULTS: The present study found that pretreatment of HT-29 cells with ET decreases their survival and colony formation. Higher concentrations of ET cause total apoptosis and an increase in NO levels in irradiated cells. CONCLUSION: Applying ET in a concentration-dependent manner had an incremental effect on the amount of apoptosis and cell death induced by radiation.

Lung Segmentation using Active Shape Model to Detect the Disease from Chest Radiography.

BACKGROUND: Some parametric models are used to diagnose problems of lung segmentation more easily and effectively. OBJECTIVE: The present study aims to detect lung diseases (nodules and tuberculosis) better using an active shape model (ASM) from chest radiographs. MATERIAL AND METHODS: In this analytical study, six grouping methods, including three primary methods such as physicians, Dice similarity, and correlation coefficients) and also three secondary methods using SVM (Support Vector Machine) were used to classify the chest radiographs regarding diaphragm congestion and heart reshaping. The most effective method, based on the evaluation of the results by a radiologist, was found and used as input data for segmenting the images by active shape model (ASM). Several segmentation parameters were evaluated to calculate the accuracy of segmentation. This work was conducted on JSRT (Japanese Society of Radiological Technology) database images and tuberculosis database images were used for validation. RESULTS: The results indicated that the ASM can detect 94.12 ± 2.34 % and 94.38 ± 3.74 % (mean± standard deviation) of pulmonary nodules in left and right lungs, respectively, from the JRST radiology datasets. Furthermore, the ASM model detected 88.33 ± 6.72 % and 90.37 ± 5.48 % of tuberculosis in left and right lungs, respectively. CONCLUSION: The ASM segmentation method combined with pre-segmentation grouping can be used as a preliminary step to identify areas with tuberculosis or pulmonary nodules. In addition, this presented approach can be used to measure the size and dimensions of the heart in future studies.

Evaluating the radioprotective effect of single dose and daily oral consumption of green tea, grape seed, and coffee bean extracts against gamma irradiation.

INTRODUCTION: The aim of this study was to investigate and compare the radio-protective effect of green tea, grape seed, and coffee bean extracts in different oral consumption methods in mice. MATERIALS AND METHODS: In this experimental-quantitative study 150 mice in 15 equally sized groups were used. For each extract, two groups received 200 mg/kg of herbal extracts' combination for 7 and 30 consecutive days before irradiation, and one group received 800 mg/kg of the extract 2 h before irradiation (3 Gy gamma-rays of Co-60). The similar groups were classified to receive a combination of the plant extracts (green tea, grape seed, and coffee bean). Irradiation without consuming plant extract (irradiated group), and a control group were also devised. Alkaline comet and micronucleus assays were used to investigate the radioprotective effect on mice blood and bone marrow cells, respectively. RESULTS: Consumption of all plant extracts significantly decreased the radiation damage to blood and bone marrow cells, compared to the irradiated group (p < 0.01), with grape seed extract showing higher protective effect. Continuous daily oral consumption (one week/month) showed a significant higher radioprotective effect compared to single consumption (p < 0.05). Continuous consumption of the combination of the extracts showed a higher radio-protection in comparison to each of the plant extracts (p < 0.03). CONCLUSIONS: The radioprotective effect of continuous consumption (for one week/month) of the plant extracts was greater than single dose. In continuous consumption protocols, we found the synergetic property and higher radioprotective effect of the plant extract combination compared to each one.

The radioprotective effects of alpha-lipoic acid on radiotherapy-induced toxicities: A systematic review.

PURPOSE: Radiation therapy is one of the main cancer treatment modalities applied in 50-70% of cancer patients. Despite the many advantages of this treatment, such as non-invasiveness, organ-preservation, and spatiotemporal flexibility in tumor targeting, it can lead to complications in irradiated healthy cells/tissues. In this regard, the use of radio-protective agents can alleviate radiation-induced complications. This study aimed to review the potential role of alpha-lipoic acid in the prevention/reduction of radiation-induced toxicities on healthy cells/tissues. METHODS: A systematic search was performed following PRISMA guidelines to identify relevant literature on the "role of alpha-lipoic acid in the treatment of radiotherapy-induced toxicity" in the electronic databases of Web of Science, Embase, PubMed, and Scopus up to January 2021. Based on the inclusion and exclusion criteria of the present study, 278 articles were screened. Finally, 29 articles were included in this systematic review. RESULTS: The obtained results showed that in experimental in vivo models, the radiation-treated groups had decreased survival rate and body weight compared to the control groups. It was also found that radiation can induce mild to severe toxicities on gastrointestinal, circulatory, reproductive, central nervous, respiratory, endocrine, exocrine systems, etc. However, the use of alpha-lipoic acid could alleviate the radiation-induced toxicities in most cases. This radio-protective agent exerts its effects through mechanisms of anti-oxidant, anti-apoptosis, anti-inflammatory, and so on. CONCLUSION: According to the obtained results, it can be mentioned that co-treatment of alpha-lipoic acid with radiotherapy ameliorates the radiation-induced toxicities in healthy cells/tissues.