Suchergebnisse

Minhui Zhu,* Caiyun Zhang,* Donghui Chen, Shicai Chen, Hongliang Zheng Department of Otorhinolaryngology-Head and Neck Surgery, Changhai Hospital, Second Military Medical University, Shanghai 200433, China *These authors contributed equally to this work Background: Tongue squamous cell carcinoma (TSCC) is the second most common malignancy in oral carcinoma. lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was regarded as an oncogenic factor in various carcinomas. However, its underlying molecular mechanisms in the development and progression of TSCC have not been well featured till now. Methods: The expressions of MALAT1, miR-140-5p and p21 (RAC1)-activated kinase 1 (PAK1) mRNA were measured by RT-qPCR assay. The protein level of PAK1 was determined by western blot analysis. Cell viability was detected by Cell Counting Kit-8 assay. Transwell chamber was used to detect cell migratory and invasive capability. Luciferase reporter assay, RNA-binding protein immunoprecipitation (RIP) assay and biotin pull-down assay were applied to evaluate the relationship between MALAT1, miR-140-5p and PAK1. Xenograft experiments were performed to assess the effect and mechanism of MALAT1 in TSCC tumor growth. Results: The expression of MALAT1 and p21 (RAC1)-activated kinase 1 (PAK1) was upregulated and microRNA-140-5p (miR-140-5p) expression was downregulated in TSCC tissues and cells. MALAT1 knockdown induced miR-140-5p expression by direct interaction. Moreover, MALAT1 knockdown inhibited proliferation, migration, and invasion by upregulating miR-140-5p expression in TSCC cells. Additionally, PAK1 was identified as a direct target of miR-140-5p. Also, MALAT1 knockdown inhibited PAK1 expression by upregulating miR-140-5p in TSCC cells. Furthermore, miR-140-5p overexpression curbed the proliferation, migration, and invasion of TSCC cells by targeting PAK1. Finally, MALAT1 knockdown inhibited tumor growth by upregulating miR-140-5p and downregulating PAK1 in mouse xenograft models of TSCC. Conclusion: MALAT1 contributed to TSCC progression via miR-140-5p-PAK1 regulatory axis, highlighting a potential target for TSCC management. Keywords: tongue squamous cell carcinoma, lncRNA, MALAT1, miRNA-140-5p, PAK1

To investigate the seismic performance and isolation effect of a high-temperature gas-cooled reactor, a 1/20 scale model including a reactor, a spent-fuel plant, and a nuclear auxiliary plant was fabricated. In addition, 220 mm lead-rubber bearings were designed and produced for use in the shaking table test, which included both isolated and nonisolated conditions. Two historical earthquake records and three artificial earthquake motions were used to input the ground motion in the tests. The results demonstrated that the seismic performance of the plant was better and that the structure was in an elastic state, under a safe shutdown earthquake event. Isolation bearings were found to effectively reduce the dominate frequency of the structure. The acceleration amplification factor of the superstructure was found to be less than 1. The isolation test results showed that the peak of the floor response spectrum at the pressure vessel support was less than 0.1 g. In the nonisolation test, the peak of the floor response spectrum was greater than 1 g. In the isolation test, the relative displacement of the structure was less than 1.1 mm, which was relatively small. The structure maintained a good isolation performance and exhibited improved safety under extreme ground motion.