The landscape of aging

Aging is characterized by a progressive deterioration of physiological integrity,leading to impaired functional ability and ultimately increased susceptibility to death.It is a major risk factor for chronic human diseases,including cardiovascular disease,diabetes,neurological degeneration,and cancer.Therefore,the growing emphasis on “healthy aging” raises a series of important questions in life and social sciences.In recent years,there has been unprecedented progress in aging research,particularly the discovery that the rate of aging is at least partly controlled by evolutionarily conserved genetic pathways and biological processes.In an attempt to bring full-fledged understanding to both the aging process and age-associated diseases,we review the descriptive,conceptual,and interventive aspects of the landscape of aging composed of a number of layers at the cellular,tissue,organ,organ system,and organismal levels.

SOX2 in cancer stemness: tumor malignancy and therapeutic potentials

Cancer stem cells(CSCs),a minor subpopulation of tumor bulks with self-renewal and seeding capacity to generate new tumors,posit a significant challenge to develop effective and long-lasting anti-cancer therapies.The emergence of drug resistance appears upon failure of chemo-/radiation therapy to eradicate the CSCs,thereby leading to CSC-mediated clinical relapse.Accumulating evidence suggests that transcription factor SOX2,a master regulator of embryonic and induced pluripotent stem cells,drives cancer stemness,fuels tumor initiation,and contributes to tumor aggressiveness through major drug resistance mechanisms like epithelial-to-mesenchymal transition,ATP-binding cassette drug transporters,anti-apoptotic and/or pro-survival signaling,lineage plasticity,and evasion of immune surveillance.Gaining a better insight and comprehensive interrogation into the mechanistic basis of SOX2-mediated generation of CSCs and treatment failure might therefore lead to new therapeutic targets involving CSC-specific anti-cancer strategies.

The key role of CYC2 during meiosis in Tetrahymena thermophila

Meiotic recombination is carried out through a special- ized pathway for the formation and repair of DNA dou- ble-strand breaks （DSBs） made by the Spo11 protein. The present study shed light on the functional role of cyclin, CYC2, in Tetrahymena thermophila which has transcriptionally high expression level during meiosis process. Knocking out the CYC2 gene results in arrest of meiotic conjugation process at 2.5-3.5 h after conjugation initiation, before the meiosis division starts, and in company with the absence of DSBs. To investigate the underlying mechanism of this phenomenon, a complete transcriptome profile was performed between wild-type strain and CYC2 knock-out strain. Functional analysis of RNA-Seq results identifies related differentially expressed genes （DEGs） including SP011 and these DEGs are enriched in DNA repair/mismatch repair （MMR） terms in homologous recombination （HR）, which indicates that CYC2 could play a crucial role in meiosis by regulating SP011 and participating in HR.

Epigenomic profiling identifies the role of Nr5a2 and CYP1B1 in hepatocellular carcinoma stemness maintenance

Cancer stem cells (CSCs) are largely responsible for the formation of tumor heterogeneity and tumor’s resistance to traditional treatments such as chemotherapy due to its self-renew capability and multi-lineage differentiation potential (1)However, it remains elusive how the CSCs maintain their stemness, thus restricting the development of therapeutic treatments specifically targeting the CSCs.