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BackgroundLung cancer is the leading cause of cancer-related morbidity and mortality all over the world. Surgery resection, radiotherapy, chemotherapy, immunotherapy and combined treatments have been discovered and well established for treatments. However, low survival rate of five years after clinical treatments mainly due to recurrence of stress-resistant cancer cells calls for better understanding and new ideas. Our project aimed to understand the forming process of stress resistant lung cancer cells after radiotherapy.MethodsTwo classic non-small cell lung cancer (NSCLC) cell lines A549 and H1299 initially were radiated with a 137Cs gamma-ray source with doses ranging from 0 to 12 Gy to generate radiation-resistant cancer cells. 8 Gy of radiation was regard as a standard dosage since it provides effective killing as well as good amount of survivals. The expression levels of autophagy-related proteins including Beclin-1, LC3-II and p62 were studied and measured by both western blot and quantitative real-time polymerase chain reaction (real-time RT-PCR).ResultsIncreased Beclin-1, LC3-II and decreased p62 have been observed in radiation-resistant cells indicating elevated autophagy level. Decreased miR-191 in radiation-resistant cells performed by Taqman qRT-PCR also has been seen. Two binding sites between Beclin-1 and miR-191 suggest potential association between.ConclusionsIt is reasonable to speculate that inhibition of miR-191 expression in lung cancer cells would contribute to the establishment of radiation-resistant cells via mediating cellular autophagy. Therefore, miR-191 is a potential target for therapy in treating radiation-resistant lung cancer.

For aluminum alloys, grain refinement is one of the effective methods for improving both strength and ductility. However, the refining effect of Al-Ti-B master alloy refiners deteriorates due to the agglomeration and sinking of the second phase particles. In this paper, the effects of rare earth type, rare earth content, and holding time on the microstructure and properties of Al-5Ti-B + RE/6111 were investigated by orthogonal experiment. It was shown that the addition of rare earth promoted the transformation of the β-Al5FeSi phase to anα-Al15(Mn,Fe)3Si2 phase, while the segregation of rare earth made it difficult for TiB2 to aggregate and inhibited the growth of TiAl3, resulting in more particles becoming effective nucleation substrates. The Al-5Ti-B + Ce master alloy developed based on orthogonal experiment improved the refinement recession problem well and improved the comprehensive mechanical properties of 6111 aluminum alloy. It was found that the addition of Al-5Ti-B + 0.1Ce, which had an ultimate tensile strength of 240.4 ± 2.2 MPa, successfully reduced the grain size by 73.8% and improved elongation by 37.8% compared to the base alloy. There search is of great significance for the preparation and application of high-performance rare earth 6111 aluminum alloy.

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