SHP2 promotes proliferation of breast cancer cells through regulating Cyclin D1 stabilityviathe PI3K/AKT/GSK3β signaling pathway

Objective:The tyrosine phosphatase SHP2 has a dual role in cancer initiation and progression in a tissue type-dependent manner.Several studies have linked SHP2 to the aggressive behavior of breast cancer cells and poorer outcomes in people with cancer.Nevertheless,the mechanistic details of how SHP2 promotes breast cancer progression remain largely undefined.Methods:The relationship between SHP2 expression and the prognosis of patients with breast cancer was investigated by using the TCGA and GEO databases.The expression of SHP2 in breast cancer tissues was analyzed by immunohistochemistry.CRISPR/Cas9 technology was used to generate SHP2-knockout breast cancer cells.Cell-counting kit-8,colony formation,cell cycle,and EdU incorporation assays,as well as a tumor xenograft model were used to examine the function of SHP2 in breast cancer proliferation.Quantitative RT-PCR,western blotting,immunofluorescence staining,and ubiquitination assays were used to explore the molecular mechanism through which SHP2 regulates breast cancer proliferation.Results:High SHP2 expression is correlated with poor prognosis in patients with breast cancer.SHP2 is required for the proliferation of breast cancer cellsin vitro and tumor growthin vivo through regulation of Cyclin D1 abundance,thereby accelerating cell cycle progression.Notably,SHP2 modulates the ubiquitin–proteasome-dependent degradation of Cyclin D1viathe PI3K/AKT/GSK3βsignaling pathway.SHP2 knockout attenuates the activation of PI3K/AKT signaling and causes the dephosphorylation and resultant activation of GSK3β.GSK3βthen mediates phosphorylation of Cyclin D1 at threonine 286,thereby promoting the translocation of Cyclin D1 from the nucleus to the cytoplasm and facilitating Cyclin D1 degradation through the ubiquitin–proteasome system.Conclusions:Our study uncovered the mechanism through which SHP2 regulates breast cancer proliferation.SHP2 may therefore potentially serve as a therapeutic target for breast cancer.

DNA methylation clocks for estimating biological age in Chinese cohorts

Epigenetic clocks are accurate predictors of human chronological age based on the analysis of DNA methylation(DNAm)at specific CpG sites.However,a systematic comparison between DNA methylation data and other omics datasets has not yet been performed.Moreover,available DNAm age predictors are based on datasets with limited ethnic representation.To address these knowledge gaps,we generated and analyzed DNA methylation datasets from two independent Chinese cohorts,revealing age-related DNAm changes.Additionally,a DNA methylation aging clock(iCAS-DNAmAge)and a group of DNAm-based multi-modal clocks for Chinese individuals were developed,with most of them demonstrating strong predictive capabilities for chronological age.The clocks were further employed to predict factors influencing aging rates.The DNAm aging clock,derived from multi-modal aging features(compositeAge-DNAmAge),exhibited a close association with multi-omics changes,lifestyles,and disease status,underscoring its robust potential for precise biological age assessment.Our findings offer novel insights into the regulatory mechanism of age-related DNAm changes and extend the application of the DNAm clock for measuring biological age and aging pace,providing the basis for evaluating aging intervention strategies.

Generation of a Hutchinson-Gilford progeria syndrome monkey model by base editing

Many human genetic diseases,including Hutchinson-Gilford progeria syndrome(HGPS),are caused by single point mutations.HGPS is a rare disorder that causes premature aging and is usually caused by a de novo point mutation in the LMNA gene.Base editors(BEs)composed of a cytidine deaminase fused to CRISPR/Cas9 nickase are highly efficient at inducing C to T base conversions in a programmable manner and can be used to generate animal disease models with single amino-acid substitutions.Here,we generated the first HGPS monkey model by delivering a BE mRNA and guide RNA(gRNA)targeting the LMNA gene via microinjection into monkey zygotes.Five out of six newborn monkeys carried the mutation specifically at the target site.HGPS monkeys expressed the toxic form of lamin A,progerin,and recapitulated the typical HGPS phenotypes including growth retardation,bone alterations,and vascular abnormalities.Thus,this monkey model genetically and clinically mimics HGPS in humans,demonstrating that the BE system can efficiently and accurately generate patient-specific disease models in non-human primates.

Single-nucleus transcriptomics reveals a gatekeeper role for FoxP1 in primate cardiac aging

Aging poses a major risk factor for cardiovascular diseases,the leading cause of death in the aged population.However,the cell type-specific changes underlying cardiac aging are far from being clear.Here,we performed single-nucleus RNA-sequencing analysis of left ventricles from young and aged cynomolgus monkeys to define cell composition changes and transcriptomic alterations across different cell types associated with age.We found that aged cardiomyocytes underwent a dramatic loss in cell numbers and profound fluctuations in transcriptional profles.Via transcription regulatory network analysis,we identified FOxP1,a core transcription factor in organ development,as a key downregulated factor in aged cardiomyocytes,concomitant with the dysregulation of FoxP1 target genes associated with heart function and cardiac diseases.Consistently,the deficiency of FOxP1 led to hypertrophic and senescent phenotypes in human embryonic stem cell-derived cardiomyocytes.Altogether,our findings depict the celiular and molecular landscape of ventricular aging at the single-cell resolution,and identify drivers for primate cardiac aging and potential targets for intervention against cardiac aging and associated diseases.

CRISPR-based screening identifies XPO7 as a positive regulatorof senescence

Dear Editor,Cells enter senescence,or irreversible growth arrest,when exposed to stressors such as DNA damage,epigenetic alterations and chronic inflammation(Zhao and Chen,2022).In aging and aging-related diseases,senescent cells are known to accumulate across tissues and organs(Sun et al.,2022;Lopez-Otin et al.,2023).