RESUMEN
As a limiting factor in telomerase activity,telomerase reverse transcriptase(TERT)controls cellular senescence and apoptosis by maintaining telomere length.TERT is not expressed or little expressed in most normal cells.However,the abnormal overexpression of TERT promotes the ability of tumor cells to replicate indefinitely.This review summarizes the regulatory mechanisms of TERT expression,including the main transcription factor families,single nucleotide polymorphism sites,and epigenetic modification changes such as DNA methylation,histone modification,and non-coding RNA.The role of these molecular mechanisms as well as significant TERT single-base variants and virus integration variants in the occurrence and development of cancer are reviewed.On this basis,its application in tumor diagnosis and prognosis is discussed.
RESUMEN
Upper respiratory tract is directly connected with the external environment， and its natural immune system is the first line of defense against pathogens. In antiviral infection， interferon （IFN） is the main component of the antiviral natural immune system and IFN-λ is a newly discovered immune effector molecule that is mainly produced in the mucosal barrier. IFN-λ exerts a biological role through Janus kinase （JAK） and signal transducer and activator of transcription （STAT） signaling pathway， and plays an important part in regulating innate and acquired immunity of respiratory mucosa. IFN-λ principally expresses on the mucosal barrier with a long-lasting antiviral impact and controls immune-inflammatory damage， which is becoming a new focus of antiviral immunity research in the upper respiratory tract， especially in fighting against 2019 novel coronavirus diseases （COVID-19）. Thus， we summarize the research progress of IFN-λ antiviral immunity in the upper respiratory tract to provide new insight in the prevention and treatment of viral infection in the upper respiratory tract.
RESUMEN
Malignant tumors can be classified into three categories， rapidly progressing tumors， slowly progressing tumors， and "indolent" tumors. Rapidly progressing tumors （such as liver cancer， pancreatic cancer， and cholangiocarcinoma） have acute onset， shorter time duration from onset to death， and poorer treatment effects， which warrants primary prevention. Slowly progressing tumors （such as lung cancer， colorectal cancer， breast cancer， and gastric cancer） have slow onset， clear precancerous lesions， longer time duration from onset to death， and better therapeutic effects， which is accordingly suitable for secondary prevention. “Indolent” tumors （such as prostate and thyroid cancer） do not affect the life expectancy and are suitable for tertiary prevention. Early screening of “indolent” tumors may lead to overtreatment. Furthermore， early screening of rapidly progressing tumors is difficult to identify early cancers， which results in low cost-effectiveness. In contrast， for slowly progressing tumors suitable for secondary prevention， early screening may have cost-effectiveness， though there might be over-diagnosis. It is crucial to adopt appropriate prevention and treatment strategies for diverse types of tumors. Currently， large-scale cohort studies and randomized controlled clinical trials with complete follow-up may accurately evaluate the effect of cancer prevention strategies. This review discusses the significance of screening in precision prevention of tumors based on the characteristics of tumor progression and patients’ prognosis.
