ATF3 is a stress-inducible gene that encodes a member of the ATF/CREB family of transcription factors. Current literature indicates that ATF3 affects cell death and cell cycle progression. However, controversies exist, because it has been demonstrated to be a negative or positive regulator of these processes. We sought to study the roles of ATF3 in both cell death and cell cycle regulation in the same cell type using mouse fibroblasts. We show that ATF3 promotes apoptosis and cell cycle arrest. Fibroblasts deficient in ATF3 (ATF3(-/-)) were partially protected from UV-induced apoptosis, and fibroblasts ectopically expressing ATF3(-/-) under the tet-off system exhibited features characteristic of apoptosis upon ATF3 induction. Furthermore, ATF3(-/-) fibroblasts transitioned from G(2) to S phase more efficiently than the ATF3(+/+) fibroblasts, suggesting a growth arrest role of ATF3. Consistent with the growth arrest and pro-apoptotic roles of ATF3, ATF3(-) fibroblasts upon Ras transformation exhibited higher growth rate, produced more colonies in soft agar, and formed larger tumor upon xenograft injection than the ATF3(+/+) counterparts. ATF3(-/-) cells, either with or without Ras transformation, had increased Rb phosphorylation and higher levels of various cyclins. Significantly, ATF3 bound to the cyclin D1 promoter as shown by chromatin immunoprecipitation (ChIP) assay and repressed its transcription by a transcription assay. Taken together, our results indicate that ATF3 promotes cell death and cell arrest, and suppresses Ras-mediated tumorigenesis. Potential explanations for the controversy about the roles of ATF3 in cell cycle and cell death are discussed.
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http://dx.doi.org/10.1074/jbc.M509278200 | DOI Listing |
Oncol Rep
March 2025
Graduate Institute of Nanomedicine and Medical Engineering, College of Medical Engineering, Taipei Medical University, Taipei 11031, Taiwan, R.O.C.
Epidermal growth factor (EGF) binds with its surface receptor to stimulate gene expression and cancer cell proliferation. EGF stimulates cancer cell growth via phosphoinositide 3‑kinase (PI3K) and programmed cell death ligand 1 (PD‑L1) pathways. As an integrin αvβ3 antagonist, heteronemin exhibits potent cytotoxic effects against cancer cells.
View Article and Find Full Text PDFInt J Oncol
February 2025
Department of Pathology, GROW Research Institute for Oncology and Reproduction, Maastricht University Medical Center, 6229HX Maastricht, The Netherlands.
Human papillomavirus (HPV)‑positive and -negative head and neck squamous cell carcinoma (HNSCC) are often associated with activation of the phosphatidylinositol 3‑kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway due to mutations or amplifications in , loss of or activation of receptor tyrosine kinases. In HPV‑negative tumors, (encoding p16 protein) inactivation or (encoding Cyclin D1 protein) amplification frequently results in sustained cyclin‑dependent kinase (CDK) 4/6 activation. The present study aimed to investigate the efficacy of the CDK4/6 inhibitors (CDKi) palbociclib and ribociclib, and the PI3K/Akt/mTOR pathway inhibitors (PI3Ki) gedatolisib, buparlisib and alpelisib, in suppressing cell viability of HPV‑positive and ‑negative HNSCC cell lines.
View Article and Find Full Text PDFMol Med Rep
March 2025
State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Macau, SAR 999078, P.R. China.
Subarachnoid hemorrhage (SAH), a prevalent cerebrovascular condition associated with a high mortality rate, frequently results in neuronal apoptosis and an unfavorable prognosis. The adjunctive use of traditional Chinese medicine (TCM) with surgical interventions exerts a therapeutic impact on SAH, potentially by facilitating apoptosis. However, the mechanism by which TCM mediates apoptosis following SAH remains unclear.
View Article and Find Full Text PDFMol Med Rep
March 2025
The First Central Clinical School, Tianjin Medical University, Tianjin 300000, P.R. China.
Hepatocellular carcinoma (HCC) is a common cause of cancer‑related mortality and morbidity worldwide. While iodine‑125 (I) particle brachytherapy has been extensively used in the clinical treatment of various types of cancer, the precise mechanism underlying its effectiveness in treating HCC remains unclear. In the present study, MHCC‑97H cells were treated with I, after which, cell viability and proliferation were assessed using Cell Counting Kit‑8, 5‑ethynyl‑2'‑deoxyuridine and colony formation assays, cell invasion and migration were evaluated using wound healing and Transwell assays, and cell apoptosis was determined using flow cytometry.
View Article and Find Full Text PDFEndocr Metab Immune Disord Drug Targets
January 2025
Department of Orthopaedic Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China.
Background: Osteoporosis (OP) is a skeletal condition characterized by increased susceptibility to fractures. Programmed cell death (PCD) is the orderly process of cells ending their own life that has not been thoroughly explored in relation to OP.
Objective: This study is to investigate PCD-related genes in OP, shedding light on potential mechanisms underlying the disease.
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