The accumulation of molecular genetic defects selected during the adaptation process in the development of cisplatin-resistance was studied using progressive cisplatin-resistant variants (L1210/DDP2, L1210/DDP5, L1210/DDP10) derived from a murine leukemia cell line (L1210/0). Of these cell lines, only the most resistant L1210/DDP10 was cross-resistant to etoposide and deficient in apoptosis induced by these two drugs, indicating that resistance to DNA-damaging agents correlates with a defect in apoptosis. This defect was tightly associated with the loss of a Ca2+/Mg2+-dependent nuclear endonuclease activity present in the less cisplatin-resistant cells. Evidence is presented that p53-dependent function (a) is lost not only in the apoptosis defective L1210/DDP10 cells, but also in the apoptosis susceptible L1210/DDP5 cells; (b) is unrelated to drug-induced cell cycle perturbations. These results suggest that deficiency in the p53 pathway and resistance to DNA-damaging agents due to a defect in apoptosis are independent events.
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http://dx.doi.org/10.1038/sj.cdd.4400357 | DOI Listing |
Protein phosphatases are critical for regulating cell signaling, cell cycle, and cell fate decisions, and their dysregulation leads to an array of human diseases like cancer. The dual specificity phosphatases (DUSPs) have emerged as important factors driving tumorigenesis and cancer therapy resistance. DUSP12 is a poorly characterized atypical DUSP widely conserved throughout evolution.
View Article and Find Full Text PDFInt J Gynaecol Obstet
January 2025
Center for Reproductive Medicine, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning, China.
Objective: Polycystic ovary syndrome (PCOS) is a diverse condition with an unknown cause. The precise mechanism underlying ovulatory abnormalities in PCOS remains unclear. It is widely believed that malfunction of granulosa cells is the primary factor contributing to aberrant follicular formation in PCOS.
View Article and Find Full Text PDFFree Radic Biol Med
January 2025
Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, Rehabilitation Medicine Center, West China Hospital, Sichuan University /West China School of Nursing, Sichuan University, Chengdu, 610041, China; Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital, Sichuan University, Chengdu 610041, China. Electronic address:
The multi-kinase inhibitor sorafenib has shown potential to inhibit tumor cell growth and intra-tumoral angiogenesis by targeting several kinases, including VEGFR2 and RAF. Abnormal activation of the Ras/Raf/MAPK/ERK kinase cascade and the VEGF pathway is a common feature in breast cancer. However, the efficacy of sorafenib in breast cancer treatment remains limited.
View Article and Find Full Text PDFBrain Res
January 2025
Neuropharmacology Division, Department of Pharmacology, ISF College of Pharmacy, Moga 142001, Punjab, India. Electronic address:
Neurodegenerative disorders are characterized by a progressive loss of neurons, causing substantial deficits in motor and cognitive functioning. Bilirubin is a yellow by-product of heme, existing in two primary isoforms namely unconjugated and conjugated, while initially produced unconjugated isomer is lipophilic and cytotoxic in nature. At physiological levels, bilirubin has an important role in brain function by acting as a powerful antioxidant, preventing brain tissues from oxidative damage by eliminating reactive oxygen species (ROS).
View Article and Find Full Text PDFCell Rep
January 2025
Department of Neurological Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA; The Brain Tumor Center, Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO 63110, USA. Electronic address:
Mutation or deletion of the deubiquitinase USP7 causes Hao-Fountain syndrome (HAFOUS), which is characterized by speech delay, intellectual disability, and aggressive behavior and highlights important unknown roles of USP7 in the nervous system. Here, we conditionally delete USP7 in glutamatergic neurons in the mouse forebrain, triggering disease-relevant phenotypes, including sensorimotor deficits, impaired cognition, and aggressive behavior. Although USP7 deletion induces p53-dependent neuronal apoptosis, most behavioral abnormalities in USP7 conditional knockout mice persist following p53 loss.
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