Objective:To explore the effects of combining APR-246 with irradiation for enhancing anti-tumor immune response against 4T1 breast cancer cells, and to develop multiple tumor treatment strategies.Methods:The control group, APR-246 group, irradiation group and irradiation combined APR-246 group were used both in the cell experiment and tumor-bearing mice experiment. The inhibitory effect of APR-246 on the proliferation of 4T1 cells was assessed by using Cell Counting Kit-8. The effect of APR-246 with irradiation on the survival rate of 4T1 cells using clone formation assay was measured. The levels of reactive oxygen species (ROS) and lipid peroxidation (LPO) in tumor cells using a 2’, 7’-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe and a lipid peroxidation sensor, the tumor inhibition rates of different groups of tumor bearing mice were compared, and the proportions of CD4+ and CD8+ T cells and the ratio of M1/M2 macrophages were determined in the tumor microenvironment by flow cytometry.Results:Compared with irradiation group, 2, 4, 6 Gy irradiation combined APR-246 group significantly reduced the survival rates of 4T1 cells ( t = 2.89, 4.15, 2.62, P < 0.05), the 6 Gy irradiation combined APR-246 group significantly increased the levels of ROS ( t = 16.95, P < 0.05) and LPO ( t = 6.09, P < 0.05) in 4T1 cells, and significantly increased the apoptosis rate of 4T1 cells ( t = 10.99, P < 0.05). Meanwhile, from the 16 th day of tumor inoculation, the 10 Gy irradiation combined APR-246 group showed significantly inhibited tumor growth ( t = 2.38-2.91, P < 0.05) and significantly increased proportions of CD4+ and CD8+ T cells ( t = 9.96, 6.28, P < 0.05) and M1/M2 ratio ( t = 15.30, P < 0.05) in tumor tissues. Conclusions:APR-246 combined with irradiation can effectively increase ROS and LPO levels in 4T1 cells, promote tumor cell apoptosis, and induce anti-tumor immune response, thus potentially inhibiting the growth of 4T1 cells.

Objective:To explore the protective effects and mechanisms of an indole-3-acetaldehyde (I3A)-loaded inulin-based hydrogel against radiation-induced intestinal injury.Methods:The gelation properties and injectability of the I3A-loaded inulin-based hydrogel were detected using a rheometer, and its biocompatibility was assessed via a CCK-8 assay. Eighteen C57BL/6 mice (aged: 6-8 weeks) were stratified by body weight and randomly assigned into three groups with 6 mice in each group: blank control, irradiation-only, and irradiation+ hydrogel protection. Abdominal irradiation was administered using 137Cs γ-rays at 17 Gy. The irradiation+ hydrogel protection group received 200 μl/day of I3A-loaded inulin-based hydrogel for two days before and 2-3 days after irradiation. Meanwhile, the irradiation-only group was treated with an equivalent volume of sterile water via gavage. The mice were euthanized four days post-irradiation, and their intestinal tissues were harvested. Hematoxylin-eosin (HE) staining, Ki67 immunohistochemistry, and TUNEL immunofluorescence were performed to assess histopathological damage, epithelial cell proliferation, and apoptosis, respectively. Quantitative real-time PCR (qRT-PCR) was employed to measure mRNA levels of inflammatory and antioxidant factors. Gut microbiota composition was analyzed via 16S rRNA sequencing. Results:The test results of the rheometer confirmed successful hydrogel formation. CCK-8 assays demonstrated excellent biocompatibility. Compared with the irradiation-only group, the irradiation+ hydrogel protection group exhibited preserved intestinal histoarchitecture, a 1.5-fold increase in intestinal cell proliferation ( t = 8.35, P < 0.05), and a 2-fold reduction in radiation-induced apoptosis ( t = 7.94, P < 0.05). Moreover, the hydrogel group showed significantly elevated expression of the anti-inflammatory cytokine IL-10 and antioxidant factors NRF-2 and HO-1 ( t = 3.16, 24.83, 5.92, P < 0.05), alongside reduced levels of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α ( t = 5.15, 3.82, 3.83, P < 0.05). Gut microbiota analysis revealed significant modulation in microbial composition and abundance in the hydrogel group. Conclusions:The I3A-loaded inulin-based hydrogel can significantly promote intestinal cell proliferation, reduce radiation-induced apoptosis, and enhance both anti-inflammatory and antioxidant responses. In addition, it regulates gut microbiota composition and abundance, protecting against radiation-induced intestinal injury.

Objective:To explore the effects of combining APR-246 with irradiation for enhancing anti-tumor immune response against 4T1 breast cancer cells, and to develop multiple tumor treatment strategies.Methods:The control group, APR-246 group, irradiation group and irradiation combined APR-246 group were used both in the cell experiment and tumor-bearing mice experiment. The inhibitory effect of APR-246 on the proliferation of 4T1 cells was assessed by using Cell Counting Kit-8. The effect of APR-246 with irradiation on the survival rate of 4T1 cells using clone formation assay was measured. The levels of reactive oxygen species (ROS) and lipid peroxidation (LPO) in tumor cells using a 2’, 7’-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe and a lipid peroxidation sensor, the tumor inhibition rates of different groups of tumor bearing mice were compared, and the proportions of CD4+ and CD8+ T cells and the ratio of M1/M2 macrophages were determined in the tumor microenvironment by flow cytometry.Results:Compared with irradiation group, 2, 4, 6 Gy irradiation combined APR-246 group significantly reduced the survival rates of 4T1 cells ( t = 2.89, 4.15, 2.62, P < 0.05), the 6 Gy irradiation combined APR-246 group significantly increased the levels of ROS ( t = 16.95, P < 0.05) and LPO ( t = 6.09, P < 0.05) in 4T1 cells, and significantly increased the apoptosis rate of 4T1 cells ( t = 10.99, P < 0.05). Meanwhile, from the 16 th day of tumor inoculation, the 10 Gy irradiation combined APR-246 group showed significantly inhibited tumor growth ( t = 2.38-2.91, P < 0.05) and significantly increased proportions of CD4+ and CD8+ T cells ( t = 9.96, 6.28, P < 0.05) and M1/M2 ratio ( t = 15.30, P < 0.05) in tumor tissues. Conclusions:APR-246 combined with irradiation can effectively increase ROS and LPO levels in 4T1 cells, promote tumor cell apoptosis, and induce anti-tumor immune response, thus potentially inhibiting the growth of 4T1 cells.

Objective:To explore the protective effects and mechanisms of an indole-3-acetaldehyde (I3A)-loaded inulin-based hydrogel against radiation-induced intestinal injury.Methods:The gelation properties and injectability of the I3A-loaded inulin-based hydrogel were detected using a rheometer, and its biocompatibility was assessed via a CCK-8 assay. Eighteen C57BL/6 mice (aged: 6-8 weeks) were stratified by body weight and randomly assigned into three groups with 6 mice in each group: blank control, irradiation-only, and irradiation+ hydrogel protection. Abdominal irradiation was administered using 137Cs γ-rays at 17 Gy. The irradiation+ hydrogel protection group received 200 μl/day of I3A-loaded inulin-based hydrogel for two days before and 2-3 days after irradiation. Meanwhile, the irradiation-only group was treated with an equivalent volume of sterile water via gavage. The mice were euthanized four days post-irradiation, and their intestinal tissues were harvested. Hematoxylin-eosin (HE) staining, Ki67 immunohistochemistry, and TUNEL immunofluorescence were performed to assess histopathological damage, epithelial cell proliferation, and apoptosis, respectively. Quantitative real-time PCR (qRT-PCR) was employed to measure mRNA levels of inflammatory and antioxidant factors. Gut microbiota composition was analyzed via 16S rRNA sequencing. Results:The test results of the rheometer confirmed successful hydrogel formation. CCK-8 assays demonstrated excellent biocompatibility. Compared with the irradiation-only group, the irradiation+ hydrogel protection group exhibited preserved intestinal histoarchitecture, a 1.5-fold increase in intestinal cell proliferation ( t = 8.35, P < 0.05), and a 2-fold reduction in radiation-induced apoptosis ( t = 7.94, P < 0.05). Moreover, the hydrogel group showed significantly elevated expression of the anti-inflammatory cytokine IL-10 and antioxidant factors NRF-2 and HO-1 ( t = 3.16, 24.83, 5.92, P < 0.05), alongside reduced levels of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α ( t = 5.15, 3.82, 3.83, P < 0.05). Gut microbiota analysis revealed significant modulation in microbial composition and abundance in the hydrogel group. Conclusions:The I3A-loaded inulin-based hydrogel can significantly promote intestinal cell proliferation, reduce radiation-induced apoptosis, and enhance both anti-inflammatory and antioxidant responses. In addition, it regulates gut microbiota composition and abundance, protecting against radiation-induced intestinal injury.