Objective To investigate the relationship of PTEN,Ki-67,type of credits of thymoma in WHO organization and Masaoka staging,and the significance of the biology's expression in thymoma.Methods The expression of PTEN and Ki-67 in 52 pieces of thymoma specimens was detected by the method of immunohistochemical SP.Results Positive expression rate of the 52 patients with thymoma was decreased gradually after WHO classification (8/10,10/14,6/12,4/11,0,0 and 10/13,12/20,6/16,0),Masaoka staging and PTEN.The difference were significant in statistics (λ2 =11.751,P =0.038 ; x2 =8.311,P =0.040).Positive expression rate of Ki-67 was gradually increased (1/10,6/14,6/12,8/11,2/3,2/2 and 3/13,9/20,10/16,3/3),the difference was also significant in statistics (x2 =11.231,P =0.047; x2 =7.904,P =0.048).Conclusions The positive expression rate of PTEN,Ki-67 are both related to clinical classification and staging closely.The detection to the positive expression rate of PTEN and Ki-67 can contribute to judging thymoma biological characteristics,thus,it will be helpful in diagnosing the thymoma,analyzing the degree of malignancy,invading and transferring ability.And then provide objective indicators for clinical diagnosis and treatment.

Radiation-induced brain injury (RBI) is the most serious complication of head and neck tumor after radiotherapy. The pathogenesis of RBI is complicated, and the clinical course is irreversible, while no effective treatment available. The activation of glial cells is one of the main theories of RBI, and the prevention and treatment of RBI by targeting glial cells is the focus of current research. As a post-transcriptional regulatory factor, microRNA (miRNA) has been confirmed to be involved in regulatingglial cell radiosensitivity, inflammation type transformation, autophagy, exosomatic, long non-coding RNA (lncRNA), circular RNA (circRNA) and other related pathways, thereby mediating the occurrence and development of cascade reaction of inflammatory injury and neurological function repair of central nervous system (CNS) disease. Therefore, the establishment of miRNA - glial regulatory network may provide a new strategy for the prevention and treatment of RBI.

Extrachromosomal DNA (ecDNA) is a small segment of circular DNA located outside the chromosome, which has the function of self-replication. Recently, amplification of oncogenes on ecDNA has been proved to be a common phenomenon in tumor cells, and has some characteristics worth studying, such as correlation with patients' poor prognosis. Multiple chromosomal events are involved in the formation of ecDNA, and its amplification can directly increase the number of DNA copies of extra-chromosomal oncogenes and accelerate the generation and development of tumors. Moreover, the segregation pattern of unequal transmission of parental ecDNA cells to offspring not only increases tumor heterogeneity, but also enhances tumor adaptation to environment and response to therapy. This article reviews the current status and potential significance of ecDNA in tumor cells.
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