Purpose: To find a new molecule that affects p53-dependent radiosensitivity.
Methods And Materials: A mouse sarcoma cell line, QRsP(p53+/+), was used. From this cell line, we established a radiosensitive clone and a radioresistant one. Colony assay, p53 gene transfer, a luciferase assay for p53 and p21, animal transplantation experiment, and DNA array analyses were performed.
Results: Microarray showed marked reduction of a transcription factor, ATF5, both in vitro and in vivo for the radiosensitive clone. Interestingly, flow cytometric analysis demonstrated marked apoptosis for the radiosensitive clone by p53 cloned adenovirus infection. Luciferase reporter assay revealed that ATF5 suppressed the transactivational activity of p53 and p63. By ATF5 gene transfer, the radiosensitive clone regained resistance to both ionizing-radiation and Ad-p53 infection-induced cell death. Surprisingly, time-lapse cell migration observation revealed greater cell motility for ATF5-transfected radiosensitive clone.
Conclusions: It seems likely that ATF5 is a potent repressor of p53 and elevated expression of ATF5 in a tumor may relate to enhanced malignant phenotypes, such as radioresistance or greater cell motility.
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http://dx.doi.org/10.1247/csf.08041 | DOI Listing |
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January 2025
College of Biological Sciences and Technology, YiLi Normal University, China. Electronic address:
Background: Radiotherapy is essential for the management of esophageal squamous cell carcinoma (ESCC). However, ESCC cells are highly susceptible to developing resistance to radiotherapy, leading to poor prognosis. Ursolic acid (UA) is a herbal monomer, has multiple medicinal benefits like anti-tumor.
View Article and Find Full Text PDFMolecules
December 2024
Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany.
Riboflavin analogs lacking one methyl group (7α or 8α) can still serve as a surrogate for riboflavin in riboflavin-deficient microorganisms or animals. The absence of both methyl groups at once completely abolishes this substitution capability. To elucidate the molecular mechanisms behind this phenomenon, we performed an adaptive laboratory evolution experiment (in triplicate) on an strain auxotrophic for riboflavin.
View Article and Find Full Text PDFCell Death Dis
December 2024
Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Urology, Peking University Cancer Hospital & Institute, Beijing, 100142, China.
Cisplatin (CDDP) resistance has been established to significantly impact Bladder Cancer (BCa) therapy. On the other hand, the crucial regulatory involvement of SIRT7 and EZH2 in bladder cancer development is well known. Herein, the collaborative regulatory roles and underlying mechanisms of SIRT7 and EZH2 in CDDP resistance in bladder cancer were explored.
View Article and Find Full Text PDFWorld J Oncol
December 2024
Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, KS, USA.
Background: Bladder cancer patients unable to receive cystectomy or who choose to pursue organ-sparing approach are managed with definitive (chemo)radiotherapy. However, this standard of care has not evolved in decades and disease recurrence and survival outcomes remain poor. Identifying novel therapies to combine with radiotherapy (RT) is therefore paramount to improve overall patient outcomes and survival.
View Article and Find Full Text PDFNeoplasia
December 2024
Departments of Gynecological Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan 250117, China. Electronic address:
Background: Radiotherapy is a major modality for esophageal cancer (ESCA) treatment, yet radioresistance severely hampers its therapeutic efficacy. Ubiquitin-specific peptidase 14 (USP14) is a novel deubiquitinase and can mediate cancer cells' response to irradiation, although the underlying mechanism remains unclear, including in ESCA.
Methods: To evaluate the expression of USP14 in ESCA tissues or cells, we used RNA-Seq, immunoblotting, co-immunoprecipitation (Co-IP), ubiquitination, quantitative real-time polymerase chain reaction (qRT-PCR), and immunofluorescence assays in this investigation.
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