Bismuth selenide nanoparticles enhance radiation sensitivity in colon cancer cells in-vitro.

Background: Radiotherapy is one of the primary treatments for cancer, but it can cause damage to normal tissues and lead to side effects. The use of radiosensitizers can enhance the sensitivity of cancer cells to radiation, thereby reducing the amount of radiation required and minimizing damage to healthy tissues. Bismuth selenide nanoparticles (Bi2Se3 NPs) have been shown to have potential as radiosensitizers. Materials and methods: In this study, we investigated the potential of Bi2Se3 NPs as a radiosensitizer in colon cancer cells (HCT-116) in vitro. The cells were treated with various concentrations of Bi2Se3 NPs and then exposed to ionizing radiation. The viability of the cells was assessed using the MTT assay, and the survival rate was evaluated. Results: Our results showed that Bi2Se3 NPs significantly enhanced the sensitivity of colon cancer cells to ionizing radiation in a dose-dependent manner. The combination of Bi2Se3 NPs and radiation resulted in a significant decrease in cell viability and survival rate compared to radiation alone. Conclusion: Bi2Se3 NPs have the potential to be used as a radiosensitizer in the treatment of colon cancer. The findings of this study suggest that combining Bi2Se3 NPs with radiation may enhance the effectiveness of radiotherapy and reduce the mortality rate associated with colon cancer. Further studies are needed to investigate the safety and efficacy of this approach in vivo.

Evaluating the Mitigation Effect of Spirulina Against Radiation-Induced Heart Injury.

BACKGROUND: During a radiological or nuclear disaster, exposure to a high dose of ionizing radiation usually results in cardiovascular diseases such as heart failure, attack, and ischemia. OBJECTIVE: The purpose of this study was to examine the mitigation effects of Spirulina in comparison to Metformin's. METHODS: 25 male Wistar rats were randomly assigned to five groups (5 rats in each): for the control group, rats did not receive any intervention. In group 2, spirulina was administered orally to rats. In group 3, rats were irradiated to the chest region with 15 Gray(Gy) x-radiation. In groups 4 and 5, rats were irradiated in the same way as group 3. Forty-eight hours after irradiation, treatment with Spirulina and Metformin began. All rats were sacrificed after ten weeks, and their heart tissues were removed for histopathological and biochemical assays. RESULTS: Results showed an elevation in Malondialdehyde (MDA) and decreasing superoxide dismutase (SOD) activity. Moreover, pathological changes of radiation were irregularities in the arrangement of myofibrils, proliferation, migration of mononuclear cells, vacuolation of the cytoplasm, and congestion. Administration of spirulina enhanced the SOD activity while did not affect MDA level and pathological change in heart tissue. Despite spirulina, metformin had a considerable effect on pathological lesions and decreased the level of MDA. CONCLUSION: Reactive oxygen species (ROS) may be involved in the late effects of radiationinduced heart injury, and scavenging these particles may contribute to reduced radiation side effects. Based on these results, Spirulina had no effect on radiation-induced cardiac damage, while metformin did. Higher Spirulina doses given over a longer period of time will likely have a greater heart-mitigate effect.

MiR-185 enhances radiosensitivity of colorectal cancer cells by targeting IGF1R and IGF2.

OBJECTIVE: Radioresistance is a significant obstacle for effective treatment of colorectal cancer (CRC). Recent studies have indicated that miR-185 inhibits proliferation, survival, and invasion of CRC; however, the role of this miRNA in radioresistance of CRC has not been identified yet. The aim of this study is to investigate the role of miR-185 in radiosensitivity of CRC. METHODS: After transfecting the cells with mimic miR-185, expressions of IGF1R and IGF2 were evaluated by real-time PCR and western blot. The radiation response of transfected cells was also examined by colony forming assay. Sub-G1 fraction analysis through flow cytometry and caspase 3 activity was used to evaluate apoptosis. RESULTS: The results of real-time PCR and western blot indicated that IGF1R and IGF2 are downregulated in the transfected cells. Colony forming assay revealed that transfected cells were more radiosensitive than other cells. On the other hand,following irradiation the rate of apoptosis was significantly higher in the transfected cells than in the other cells. CONCLUSION: In summary, our study is the first to show that upregulation of miR-185 enhances the sensitivity of CRC cells to ionizing radiation. miR-185 may act as a novel biomarker of radioresistance and may clinically enhance the radiation response of CRC.

Involvement of miR-155/FOXO3a and miR-222/PTEN in acquired radioresistance of colorectal cancer cell line.

PURPOSE: Finding a novel biomarker for determining the radiosensitivity of colorectal cancer (CRC) is critical. The aim of this study is to evaluate the role of two main miRNAs including miR-222 and miR-155 in radiation response of CRC. MATERIALS AND METHODS: The radioresistant CRC cell lines were established by exposing the HCT 116 cell line to fractional X-ray radiation. SubG1 fraction analysis, MTT and clonogenic assays were applied to evaluate acquired radioresistant cell line radiosensitivity. miR-222/PTEN and miR-155/FOXO3a expressions were detected by RT PCR. RESULTS: The clonogenic assay and sub-G1fraction analysis indicated that the RR2 sub-line was significantly more resistant than the parental cell line. MiR-222 and miR-155 were significantly upregulated in the radioresistant cell lines compared with the parental cell lines. The PTEN and FOXO3a expressions in the radioresistant cell lines were significantly higher than in the parental line. CONCLUSION: These observations indicate that miR-222 and miR-155 could induce radiation resistance in colorectal cancer by targeting PTEN and FOXO3a genes, respectively. Therefore, miR-222 and miR-155 can be suggested as good biomarkers of CRC radiation response.