BACKGROUND: P16 inactivation is frequently accompanied by telomerase reverse transcriptase ( TERT ) amplification in human cancer genomes. P16 inactivation by DNA methylation often occurs automatically during immortalization of normal cells by TERT . However, direct evidence remains to be obtained to support the causal effect of epigenetic changes, such as P16 methylation, on cancer development. This study aimed to provide experimental evidence that P16 methylation directly drives cancer development. METHODS: A zinc finger protein-based P16 -specific DNA methyltransferase (P16-Dnmt) vector containing a "Tet-On" switch was used to induce extensive methylation of P16 CpG islands in normal human fibroblast CCD-18Co cells. Battery assays were used to evaluate cell immortalization and transformation throughout their lifespan. Cell subcloning and DNA barcoding were used to track the diversity of cell evolution. RESULTS: Leaking P16-Dnmt expression (without doxycycline-induction) could specifically inactivate P16 expression by DNA methylation. P16 methylation only promoted proliferation and prolonged lifespan but did not induce immortalization of CCD-18Co cells. Notably, cell immortalization, loss of contact inhibition, and anchorage-independent growth were always prevalent in P16-Dnmt&TERT cells, indicating cell transformation. In contrast, almost all TERT cells died in the replicative crisis. Only a few TERT cells recovered from the crisis, in which spontaneous P16 inactivation by DNA methylation occurred. Furthermore, the subclone formation capacity of P16-Dnmt&TERT cells was two-fold that of TERT cells. DNA barcoding analysis showed that the diversity of the P16-Dnmt&TERT cell population was much greater than that of the TERT cell population. CONCLUSION P16 methylation drives TERT -mediated immortalization and transformation of normal human cells that may contribute to cancer development.
Humans ; Telomerase/genetics* ; DNA Methylation/physiology* ; Fibroblasts/cytology* ; Cyclin-Dependent Kinase Inhibitor p16/metabolism* ; Cell Line ; Cell Transformation, Neoplastic/genetics*

Copy number alteration (CNA) is a significant genetic change in pediatric B-cell acute lymphoblastic leukemia (B-ALL), with CDKN2A/B deletions, PAX5 deletions, and IKZF1 deletions being the most common. Recent studies have increasingly highlighted the potential prognostic significance of these gene deletions and multiple co-deletions in pediatric B-ALL. This paper reviews the main detection methods for CNA, as well as the prognostic characteristics and treatment approaches for common CNA in pediatric B-ALL.
Humans ; DNA Copy Number Variations ; Child ; PAX5 Transcription Factor/genetics* ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; Cyclin-Dependent Kinase Inhibitor p15/genetics* ; Ikaros Transcription Factor/genetics* ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; Gene Deletion ; Cyclin-Dependent Kinase Inhibitor p16/genetics* ; Prognosis

OBJECTIVE: To investigate the relationship between CDKN2A copy number deletion and clinical features of patients with diffuse large B-cell lymphoma (DLBCL) and its prognostic value. METHODS: 155 newly diagnosed DLBCL patients with complete clinical data in the Department of Hematology of People's Hospital of Xinjiang Uygur Autonomous Region from March 2009 to March 2022 were included, formalin-fixed paraffin-embedded tumor tissues were obtained and DNA was extracted from them, and next-generation sequencing technology was applied to target sequencing including 475 lymphoma-related genes, the relationship between CDKN2A copy number deletion and clinical features, high-frequency mutated genes and overall survival (OS) of DLBCL patients were analyzed. RESULTS: CDKN2A copy number deletion was present in 12.9% (20/155) of 155 DLBCL patients, grouped according to the presence or absence of copy number deletion of CDKN2A, and a higher proportion of patients with IPI≥3 were found in the CDKN2A copy number deletion group compared to the group with no CDKN2A copy number deletion (80% vs 51.5%, P =0.015) and were more likely to have bulky disease (20% vs 5.2%, P =0.037). Survival analysis showed that the 5-year OS of patients in the CDKN2A copy number deletion group was significantly lower than that of the non-deletion group (51.3% vs 69.2%, P =0.047). Multivariate Cox analysis showed that IPI score≥3 (P =0.007), TP53 mutation (P =0.009), and CDKN2A copy number deletion (P =0.04) were independent risk factors affecting the OS of DLBCL patients. CONCLUSION CDKN2A copy number deletion is an independent risk factor for OS in DLBCL, and accurate identification of CDKN2A copy number deletion can predict the prognosis of DLBCL patients.
Humans ; Lymphoma, Large B-Cell, Diffuse/genetics* ; Prognosis ; Cyclin-Dependent Kinase Inhibitor p16/genetics* ; DNA Copy Number Variations ; Female ; Male ; Middle Aged ; Gene Deletion ; Adult ; Aged

OBJECTIVE: To investigate the effects and mechanisms of hydroxysafflor yellow A (HSYA) on replicative senescence in human umbilical cord mesenchymal stem cells (hUC-MSCs). METHODS: hUC-MSCs were cultured to construct a replicative senescence model through continuous amplification in vitro. Cells at passage 2 served as the control group, while cells at passage 10 were designated as the senescence group. The senescent cells were cultured in a culture medium containing HSYA. Cell viability was detected by the CCK-8 assay, and cell confluence was analyzed using the Incucyte S3 live-cell analysis system. The optimal concentration and time point were determined and utilized for subsequent experiments. Senescent cells were pretreated with 0.01 mg/ml HSYA, and the proportion of senescence-associated β-galactosidase (SA-β-gal) positive cells was detected to assess the senescence state. The relative telomere length was detected by qPCR. Reactive oxygen species (ROS) levels were measured using the fluorescent probe DCFH-DA. Mitochondrial membrane potential was assessed by JC-1 staining. The expression of p53, p16, p21, OCT4, and SOX2 genes was detected by qPCR. The expression of p16, p53, OCT4, and SOX2 proteins was analyzed by Western blot. RESULTS: HSYA significantly decreased the SA-β-gal positive staining rate, inhibited telomere attrition, reduced the ROS accumulation, increased mitochondrial membrane potential in senescent cells. Additionally, HSYA downregulated the expression of p53 and p16, and upregulated the expression of OCT4. HSYA decreased p16 protein level and increased OCT4 and SOX2 protein levels. CONCLUSION HSYA may ameliorate replicative senescence in hUC-MSCs by modulating the p53 and p16 signaling pathways and suppressing oxidative stress.
Humans ; Mesenchymal Stem Cells/drug effects* ; Cellular Senescence/drug effects* ; Chalcone/pharmacology* ; Oxidative Stress/drug effects* ; Quinones/pharmacology* ; Umbilical Cord/cytology* ; Reactive Oxygen Species/metabolism* ; Cells, Cultured ; Cyclin-Dependent Kinase Inhibitor p16/metabolism* ; Tumor Suppressor Protein p53/metabolism* ; Membrane Potential, Mitochondrial ; Cell Proliferation

OBJECTIVE: To observe the therapeutic effects and underlying mechanism of baicalin against colon cancer. METHODS: The effects of baicalin on the proliferation and growth of colon cancer cells MC38 and CT26. WT were observed and predicted potential molecular targets of baicalin for colon cancer therapy were studied by network pharmacology. Furthermore, molecular docking and drug affinity responsive target stability (DARTS) analysis were performed to confirm the interaction between potential targets and baicalin. Finally, the mechanisms predicted by in silico analyses were experimentally verified in-vitro and in-vivo. RESULTS: Baicalin significantly inhibited proliferation, invasion, migration, and induced apoptosis in MC38 and CT26 cells (all P<0.01). Additionally, baicalin caused cell cycle arrest at the S phase, while the G₀/G₁ phase was detected in the tiny portion of the cells. Subsequent network pharmacology analysis identified 6 therapeutic targets associated with baicalin, which potentially affect various pathways including 39 biological processes and 99 signaling pathways. In addition, molecular docking and DARTS predicted the potential binding of baicalin with cyclin dependent kinase inhibitor 2A (CDKN2A), protein kinase B (AKT), caspase 3, and mitogen-activated protein kinase (MAPK). In vitro, the expressions of CDKN2A, MAPK, and p-AKT were suppressed by baicalin in MC38 and CT26 cells. In vivo, baicalin significantly reduced the tumor size and weight (all P<0.01) in the colon cancer mouse model via inactivating p-AKT, CDKN2A, cyclin dependent kinase 4, cyclin dependent kinase 2, interleukin-1, tumor necrosis factor α, and activating caspase 3 and mouse double minute 2 homolog signaling (all P<0.05). CONCLUSION Baicalin suppressed the CDKN2A protein level to prevent colon cancer and could be used as a therapeutic target for colon cancer.
Flavonoids/pharmacology* ; Colonic Neoplasms/prevention & control* ; Animals ; Cell Line, Tumor ; Molecular Docking Simulation ; Cell Proliferation/drug effects* ; Apoptosis/drug effects* ; Cyclin-Dependent Kinase Inhibitor p16/metabolism* ; Mice ; Mice, Inbred BALB C ; Cell Movement/drug effects* ; Humans ; Gene Expression Regulation, Neoplastic/drug effects* ; Cell Cycle Checkpoints/drug effects*

Humans ; Squamous Cell Carcinoma of Head and Neck ; RNA, Messenger ; Immunohistochemistry ; Papillomavirus Infections/diagnosis* ; Oncogene Proteins, Viral/genetics* ; Head and Neck Neoplasms ; Cyclin-Dependent Kinase Inhibitor p16 ; Papillomaviridae ; Papillomavirus E7 Proteins/genetics* ; DNA, Viral

Aging is an independent risk factor for chronic diseases in the elderly, and understanding aging mechanisms is one of the keys to achieve early prevention and effective intervention for the diseases. Aging process is dynamic and systemic, making it difficult for mechanistic study. With recent advances in aging biomarkers and development of live-imaging technologies, more and more reporter mouse models have been generated, which can live monitor the aging process, and help investigate aging mechanisms at systemic level and develop intervention strategies. This review summarizes recent advances in live-imaging aging reporter mouse models based on widely used aging biomarkers (p16^Ink4a, p21^Waf1/Cip1, p53 and Glb1), and discusses their applications in aging research.
Humans ; Animals ; Mice ; Aged ; Aging ; Cyclin-Dependent Kinase Inhibitor p16/metabolism* ; Cyclin-Dependent Kinase Inhibitor p21/metabolism* ; Biomarkers ; Tumor Suppressor Protein p53

Objective: To assess the clinical features and treatment outcomes in patients with primary ovarian squamous cell carcinoma (POSCC). Methods: Fifteen patients with primary ovarian squamous cell carcinoma diagnosed from January 2009 to December 2018 in Cancer Hospital of the University of Chinese Academy of Sciences were collected. The expression of p16, hMLH1, hMSH2, hMSH6 and PMS2 in POSCC was detected by immunohistochemistry, and the status of high-risk human papillomavirus (HPV) by RNAscope test. Results: Squamous cell carcinoma with different degrees of differentiation was found in 15 cases, including three cases with high differentiation and 12 cases with medium to low differentiation. There were four cases with in situ squamous cell carcinoma, four cases with teratoma, one case with endometrial carcinoma/atypical hyperplasia, and one case with endometriosis. p16 was expressed in five cases (5/15), indicating coexisting high-risk HPV infection. There was no high-risk HPV infection in the remaining 10 cases, and p16 staining was negative. There was no deficient mismatch repair protein in all cases. The overall survival time (P=0.038) and progression free survival (P=0.045) of patients with high-risk HPV infection were longer than those without HPV infection. Conclusions: POSCC is more commonly noted in postmenopausal women and often occurs unilaterally. Elevated serological indexes CA125 and SCC are the most common finding. Morphologically, the tumors show variable degrees of differentiation, but the current data suggest that the degree of differentiation cannot be used as an independent prognostic index. High-risk HPV infection may be associated with the occurrence of POSCC, and that the prognosis of POSCC patients with HPV infection is better than that of patients without infection.
Carcinoma, Squamous Cell/pathology* ; Cyclin-Dependent Kinase Inhibitor p16/analysis* ; Female ; Humans ; Immunohistochemistry ; Papillomavirus Infections/diagnosis* ; Prognosis

OBJECTIVE: To investigate the methylation status of CHD5 gene promoter in bone marrow from acute myeloid leukemia (AML) patients, and the underlying mechanism for initiating the pathogenesis of AML via p19/p53/p21 pathway. METHODS: Methylation status of the CHD5 gene promoter was detected by using methylation-specific polymerase chain reaction (MSPCR) in bone marrow from AML patients, and the iron-deficiency anemia (IDA) samples were served as control. The expression of CHD5, p19, p53 and p21 was determined by real-time quantitative reverse transcriptase PCR and Western blot. RESULTS: The methylation of CHD5 gene in bone marrow from AML patients increased significantly (39.06%) as compared with control group (6.67%). The methylation of CHD5 gene significantly correlated with chromosome karyotype differentiation (P＜0.01), but did not correlate with the patient's sex, age and clinical classification (P＞0.05). The mRNA expression of CHD5 gene in AML decreased, compared with control group, the mRNA and protein expression of p19, p53 and p21 in AML with CHD5 methylation promoter decreased. CONCLUSION The hypermeltylation of CHD5 gene promoter in AML patients can lead to decrease of CHD5, p19, p53 and p21 expression levels which may reduce the inhibitory effect on proliferation of leukemia cells through the regulation of p19, p53 and p21 pathway, thus promotes the occurence of AML.
Cyclin-Dependent Kinase Inhibitor p16 ; Cyclin-Dependent Kinase Inhibitor p21 ; DNA Helicases ; DNA Methylation ; Humans ; Leukemia, Myeloid, Acute ; Nerve Tissue Proteins ; Promoter Regions, Genetic ; Tumor Suppressor Protein p53

Shenkang injection (SKI) is a classic prescription composed of Radix Astragali, rhubarb, Astragalus, Safflower, and Salvia. This treatment was approved by the State Food and Drug Administration of China in 1999 for treatment of chronic kidney diseases based on good efficacy and safety. This study aimed to investigate the protective effect of SKI against high glucose (HG)-induced renal tubular cell senescence and its underlying mechanism. Primary renal proximal tubule epithelial cells were cultured in (1) control medium (control group), medium containing 5 mmol/L glucose; (2) mannitol medium (mannitol group), medium containing 5 mmol/L glucose, and 25 mmol/L mannitol; (3) HG medium (HG group) containing 30 mmol/L glucose; (4) SKI treatment at high (200 mg/L), medium (100 mg/L), or low (50 mg/L) concentration in HG medium (HG + SKI group); or (5) 200 mg/L SKI treatment in control medium (control + SKI group) for 72 h. HG-induced senescent cells showed the emergence of senescence associated heterochromatin foci, up-regulation of P16 and cyclin D1, increased senescence-associated β-galactosidase activity, and elevated expression of membrane decoy receptor 2. SKI treatment potently prevented these changes in a dose-independent manner. SKI treatment prevented HG-induced up-regulation of pro-senescence molecule mammalian target of rapamycin and p66Shc and down-regulation of anti-senescence molecules klotho, sirt1, and peroxisome proliferator-activated receptor-g in renal tubular epithelial cells. SKI may be a novel strategy for protecting against HG-induced renal tubular cell senescence in treatment of diabetic nephropathy.
Animals ; Cells, Cultured ; Cellular Senescence ; drug effects ; Cyclin D1 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p16 ; metabolism ; Diabetic Nephropathies ; drug therapy ; Drugs, Chinese Herbal ; pharmacology ; Epithelial Cells ; drug effects ; metabolism ; Glucose ; Kidney Tubules, Proximal ; physiopathology ; Male ; Mice ; Mice, Inbred C57BL