p15(INK4b) regulates cell cycle signaling in hippocampal astrocytes of aged rats

NUP153 promotes HCC cells proliferation via c-Myc-mediated downregulation of P15INK4b

BACKGROUND AND AIM

Nucleoporin NUP153 (NUP153) is involved in the regulation of nuclear transportation, mitosis, and tumor progression in various cancer cells. we aimed to investigate the roles of NUP153 in hepatocellular carcinoma (HCC).

METHODS

NUP153 expression level and its relationship with clinical prognosis were analyzed based on The Cancer Genome Atlas (TCGA). Quantitative real-time PCR (qRT-PCR), Western Blot (WB), and Immunohistochemistry (IHC) were used to assess NUP153 expression in tissues and cell lines. Loss-of-function experiments were implemented for exploring the roles of NUP153 in HCC cells. Ultimately, how NUP153 exerted biological functions was plumbed by performing rescue assays in HCC.

RESULTS

NUP153 expressed highly in HCC tissues and cell lines. Silencing NUP153 inhibited cellular multiplication, G1/S transition, migration, and triggered cytoskeletal rearrangement of Huh7 and HepG2 cells. Knockdown NUP153 caused up-regulation of mRNA and protein levels of P15, and siRNA deprivation of P15 partially reversed the function of low-level NUP153 in HCC. Meanwhile, silencing NUP153 caused down-regulation of mRNA and protein levels of c-Myc. Furthermore, the up-regulation of P15 and cell G1/S phase arrest induced by silencing NUP153 were partially reversed by overexpression of c-Myc.

CONCLUSIONS

NUP153 increases the proliferation ability of cells via the c-Myc/P15 axis in HCC.

N6-methyladenosine-induced SVIL antisense RNA 1 restrains lung adenocarcinoma cell proliferation by destabilizing E2F1

Accumulating evidence indicates that N6-methyladenosine (m6A) and long noncoding RNAs (lncRNAs) play crucial roles in cancer development. However, the biological roles of m6A and lncRNAs in lung cancer tumorigenesis are largely unknown. In this study, SVIL antisense RNA 1 (SVIL-AS1) was downregulated in lung adenocarcinoma (LUAD) tissues and was associated with a favorable prognosis in patients with LUAD. SVIL-AS1 overexpression suppressed LUAD cell proliferation and blocked cell cycle arrest. Mechanistically, METTL3 increased the m6A modification and transcript stability of SVIL-AS1. The enhanced SVIL-AS1 expression mediated by METTL3 suppressed E2F1 and E2F1-target genes. Moreover, SVIL-AS1 accelerated E2F1 degradation. The reduction in cell proliferation induced by SVIL-AS1 overexpression could be rescued by E2F1 overexpression or METTL3 knockdown. In conclusion, our work demonstrated the role and mechanism of METTL3-induced SVIL-AS1 in LUAD, which connects m6A and lncRNA in lung cancer carcinogenesis.

A genome-wide CRISPR-based screen identifies KAT7 as a driver of cellular senescence

Understanding the genetic and epigenetic bases of cellular senescence is instrumental in developing interventions to slow aging. We performed genome-wide CRISPR-Cas9-based screens using two types of human mesenchymal precursor cells (hMPCs) exhibiting accelerated senescence. The hMPCs were derived from human embryonic stem cells carrying the pathogenic mutations that cause the accelerated aging diseases Werner syndrome and Hutchinson-Gilford progeria syndrome. Genes whose deficiency alleviated cellular senescence were identified, including KAT7, a histone acetyltransferase, which ranked as a top hit in both progeroid hMPC models. Inactivation of KAT7 decreased histone H3 lysine 14 acetylation, repressed p15^INK4b transcription, and alleviated hMPC senescence. Moreover, lentiviral vectors encoding Cas9/sg-Kat7, given intravenously, alleviated hepatocyte senescence and liver aging and extended life span in physiologically aged mice as well as progeroid Zmpste24^-/- mice that exhibit a premature aging phenotype. CRISPR-Cas9-based genetic screening is a robust method for systematically uncovering senescence genes such as KAT7, which may represent a therapeutic target for developing aging interventions.

CDKN2A/B T2D Genome-Wide Association Study Risk SNPs Impact Locus Gene Expression and Proliferation in Human Islets

Genome-wide association studies link the CDKN2A/B locus with type 2 diabetes (T2D) risk, but mechanisms increasing risk remain unknown. The CDKN2A/B locus encodes cell cycle inhibitors p14, p15, and p16; MTAP; and ANRIL, a long noncoding RNA. The goal of this study was to determine whether CDKN2A/B T2D risk SNPs impact locus gene expression, insulin secretion, or β-cell proliferation in human islets. Islets from donors without diabetes (n = 95) were tested for SNP genotype (rs10811661, rs2383208, rs564398, and rs10757283), gene expression (p14, p15, p16, MTAP, ANRIL, PCNA, KI67, and CCND2), insulin secretion (n = 61), and β-cell proliferation (n = 47). Intriguingly, locus genes were coregulated in islets in two physically overlapping cassettes: p14-p16-ANRIL, which increased with age, and MTAP-p15, which did not. Risk alleles at rs10811661 and rs2383208 were differentially associated with expression of ANRIL, but not p14, p15, p16, or MTAP, in age-dependent fashion, such that younger homozygous risk donors had higher ANRIL expression, equivalent to older donor levels. We identified several risk SNP combinations that may impact locus gene expression, suggesting possible mechanisms by which SNPs impact locus biology. Risk allele carriers at ANRIL coding SNP rs564398 had reduced β-cell proliferation index. In conclusion, CDKN2A/B locus SNPs may impact T2D risk by modulating islet gene expression and β-cell proliferation.