Regulator of G-protein signaling 5 (RGS5) belongs to RGS family,which can negatively regulate the conduction of this signaling pathway.RGS5 mainly expresses in vascular pericyte,and is closely related to the occurrence,development and maturation of the blood vessels.Loss of RGS5 results in pericyte maturation,tumor vascular normalization,and these changes can improve the curative effect combined with chemotherapy and immunotherapy,indicating that RGS5 may become a new target of anti-tumor treatment.In addition,RGS5 involves in tumor metastasis and apoptosis,which can improve antineoplastic effect by inducing tumor cells apoptosis.

Objective:To explore the potential mechanism of PD-1 inhibitor P on RIMI from the perspective of immune microenvironment.Methods:To establish a mouse model of radiation-induced myocardial injury (RIMI), twenty C57BL/6 mice were randomly divided into 4 groups, 5 in each group. Group A was the healthy control group; Group B was the PD-1 inhibitor group; Group C was the simple irradiation group, with a heart irradiation of 15 Gy; Group D was the irradiation+ PD-1 inhibitor group. One month after irradiation, the mice were anesthetized and sacrificed. The morphological changes of myocardial tissues were observed by HE staining. The myocardial fibrosis was assessed by Masson staining. CD 3+ , CD 3+ CD 4+ , CD 3+ CD 8 lymphocyte subsets and cytokines (IL-4, IL-6, IL-17A, TNF-α, TGF-β 1 and INF-γ) levels were determined by flow cytometry. The apoptosis rate of myocardial cells was detected by TUNE. Results:One month after irradiation, there was no obvious myocardial fibrosis in group B, and collagen fibers were distributed in the interstitium of myocardial cells in groups C and D. Semi-quantitative analysis results showed that the myocardial collagen volume fraction (CVF) of groups A, B, C and D were (1.97±0.36)%, (2.83±1.03)%, (5.39±0.77)% and (7.72±1.43)%, respectively. The CVF between group A and group B was similar ( P=0.314), and the differences in CVF between the other groups were statistically significant (all P<0.05). Compared with group A, the absolute value and percentage of CD 3+ T lymphocytes were significantly increased in groups B, C and D (all P<0.01). The values in group D were significantly higher than those in group B and group C (all P<0.01); The absolute value and percentage of CD 3+ CD4 T lymphocytes were similar among four groups (all P>0.05); The absolute value and percentage of CD 3+ CD 8 T lymphocytes in group D were significantly higher than those in groups A, B and C (all P<0.001). The expression levels of IL-6, IL-17A, and TGF-β 1 in group D were significantly higher compared with those in groups A, B and C (all P<0.001). The apoptotic index was gradually increased in four groups, and the differences in apoptotic index among four groups were statistically significant (all P<0.001). Conclusion:PD-1 inhibitors can aggravate RIMI by promoting myocardial immune inflammatory response.

Objective:To investigate the effect of BMAL1 gene on the proliferation, migration and invasion ability of radiation-resistant nasopharyngeal carcinoma cell line (5-8FR) and the molecular mechanism. Methods:A multi-target click model was constructed for radiation-resistant nasopharyngeal carcinoma cell line 5-8FR by low-dose fractionated irradiation, and the results of clone formation assay were used to fit the multi-target click model and calculate the sensitization ratio of radiotherapy. The expression levels of PI3K/Akt/MMP-2/9 signaling pathway-related proteins in 5-8FR and control 5-8F cell lines were detected by Western blot. The overexpression and knockdown vectors of BMAL1 gene were constructed and transfected with 5-8F and 5-8F cell lines, respectively. The BMAL1 gene overexpression (pcDNA-BMAL1) and its control (pcDNA) and interference (BMAL1-shRNA) and control (con-shRNA) cell lines were stably transfected with nasopharyngeal carcinoma cell line 5-8F and radiation-resistant cell line 5-8FR, respectively. Western blot was performed to verify the infection efficiency and detect the changes of PI3K/Akt/MMP-2/9 signaling pathway-related proteins after overexpression or interference of BMAL1 gene in both groups of cells. CCK-8 assay, cell scratch test and Transwell chamber test were conducted to investigate the proliferation, migration and invasion capabilities of 5-8FR cell line after overexpression or interference of BMAL1 gene. Results:BMAL1 gene expression was down-regulated, and those of PI3K/Akt pathway proteins and downstream related molecules of MMP-2 and MMP-9 were up-regulated, and TIMP-2 and TIMP-1 expression was down-regulated in nasopharyngeal carcinoma radiation-resistant cell lines. Overexpression of BMAL1 gene inhibited the expression of PI3K/Akt pathway proteins and downstream related molecules of MMP-2 and MMP-9, promoted the expression of TIMP-2 and TIMP-1, and inhibited the proliferation, migration and invasion capabilities of radiation-resistant nasopharyngeal carcinoma cells, while interference with BMAL1 gene yielded the opposite results. Conclusions:BMAL1 gene can reverse the expression of PI3K/Akt/MMP-2/9 signaling pathway-related proteins in radiation-resistant nasopharyngeal carcinoma cell lines and inhibit the proliferation, migration and invasion capabilities of radiation-resistant nasopharyngeal carcinoma cell lines.

Objective:To assess the effects of recombinant human endostatin (rh-ES) on radiation-induced myocardial fibrosis.Methods:Totally 40 SD rats were randomly divided into 4 groups, including A group as normal control, B group receiving rh-ES with a dosage of 6 mg·kg -1·d -1, in traperitoneal injection, for 14 consecutive days, C group with local heart irradiation delivered to the precordial region of rats in five fractions with a dose of 25 Gy, D group receiving rh-ES as the same as B group and local heart irradiation as C group. At 1 and 3 months after irradiation, five rats were killed under anesthesia. Mason staining was used to observe myocardial injury and fibrosis. Western blotting was used to detect the expression of TGF-β1, CTGF and COL-I in myocardium. Results:Masson staining showed that no obvious myocardial fibrosis was found in group B at 1 month and 3 months after irradiation, while collagen fibers were distributed in myocardium in groups C and D. One month after irradiation, the result of semi-quantitative analysis showed that the CVF in group A was (5.20 ±0.75)%, which was significantly lower than that in group C (10.12 ±2.17)% ( t=4.74、4.93, P<0.01) and the CVF in group D (10.32 ±1.36), and the CVF of group C was similar to that of group D ( P<0.01). Three months after irradiation, CVF in group C (13.17±2.67)% was still higher than that in group A (5.23 ±1.32)% ( t=4.49, P<0.01), but lower than that in group D (16.92 ±3.58)% ( t=3.19, P<0.05). One month after irradiation, the expression of TGF-β1 in group A was 0.441 ±0.063, lower than that in group C (0.817 ±0.079, t=5.81, P<0.01). Three months after irradiation, the expression of TGF-β1 in group A was 0.501 ±0.110, lower than that in group C (0.832 ±0.150, t=4.19, P<0.01), and the expression of TGF-β1 in group D was 1.403 ±0.133, which was significantly higher than that in group C ( t=7.24, P<0.01). Conclusions:Radiation can cause the formation of myocardial fibrosis, and recombinant human endostatin may aggravate the formation of late radiation fibrosis.