Purpose: This preclinical study is to determine whether the capacity of histone deacetylase (HDAC) inhibitors to enhance radiation response depends on temporal sequences of HDAC inhibition and irradiation.
Materials And Methods: The effects of HDAC inhibitors trichostatin A (TSA) and SK-7041 on radiosensitivity in human lung cancer cells were examined using a clonogenic assay, exposing cells to HDAC inhibitors in various sequences of HDAC inhibition and radiation. We performed Western blot of acetylated histone H3 and flow cytometry to analyze cell cycle phase distribution.
Results: TSA and SK-7041 augmented radiation cell lethality in an exposure time-dependent manner when delivered before irradiation. The impact of TSA and SK-7041 on radiosensitivity rapidly diminished when HDAC inhibition was delayed after irradiation. Radiation induced the acetylation of histone H3 in cells exposed to TSA, while irradiation alone had no effect on the expression of acetylated histone H3 in TSA-naïve cells. Preirradiation exposure to TSA abrogated radiation-induced G2/M-phase arrest. When delivered after irradiation, TSA had no effect on the peak of radiation-induced G2/M-phase arrest.
Conclusion: TSA and SK-7041 enhances radiosensitivity only when delivered before irradiation. Unless proven otherwise, it seems prudent to apply scheduling including preirradiation HDAC inhibition so that maximal radiosensitization is obtained.
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http://dx.doi.org/10.4143/crt.2013.45.4.334 | DOI Listing |
Background: In Alzheimer's disease (AD), histone acetylation is disrupted, suggesting loss of transcriptional control. Moreover, converging evidence suggests an age- and AD-dependent loss of transcription controlled by all-trans-retinoic acid (ATRA), the bioactive metabolite of vitamin A (VA). Antioxidant depletion causes oxidative stress (OS).
View Article and Find Full Text PDFExp Cell Res
December 2024
Medical Biotechnology lab, Faculty of Allied Health Sciences, Chettinad Hospital and Research Institute (CHRI), Chettinad Academy of Research and Education (CARE), Rajiv Gandhi Salai (OMR), Kelambakkam, Chennai, Tamil Nadu - 603 103, India. Electronic address:
Colon cancer is the leading cause of cancer-related deaths worldwide. MicroRNAs (miRNAs) are key regulators of gene expression, often dysregulated in colon cancer. This study aims to elucidate the therapeutic role of miR-134-5p as a tumor suppressor miRNA in colon cancer cells.
View Article and Find Full Text PDFJ Biol Chem
December 2024
Department of Clinical Laboratory, The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China. Electronic address:
Hepatocellular carcinoma (HCC) is one of the common malignant tumors. Complement system has become a new focus of cancer research by changing the biological behavior of cancer cells to influence the growth of cancer. Recent studies reported the complement C5a-C5aR1 axis can promote the malignant phenotype of multiple tumors through various signaling pathways.
View Article and Find Full Text PDFBioorg Chem
December 2024
The State Key Laboratory of Chemical Oncogenomics, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China; Institute of Biomedical Health Technology and Engineering, Shenzhen Bay Laboratory, Shenzhen, 518132, China; School of Pharmaceutical Sciences, Tsinghua University, Beijing, 100084, China.
The down-regulation of p21 after long-term CDK4/6 inhibition represents a key mechanism causing resistance to CDK4/6 inhibitors in some tumor cells, while the HDAC inhibitor could upregulate the level of p21. Herein, a series of novel CDK4/6 and HDAC dual-targeting inhibitors based on the moiety of palbociclib were designed and synthesized. Among them, compound N14 potently inhibited CDK4/6 and HDAC1/6 at nanomolar levels and induced cell apoptosis and G/G phase arrest through HDAC-p21-CDK signaling pathway in HuH-7 cell line.
View Article and Find Full Text PDFbioRxiv
December 2024
Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
Dysregulated epigenetic programs that restrict differentiation, reactivate fetal genes, and confer phenotypic plasticity are critical to colorectal cancer (CRC) development. By screening a small molecule library targeting epigenetic regulators using our dual reporter system, we found that inhibiting histone deacetylase (HDAC) 1/2 promotes CRC differentiation and anti-tumor activity. Comprehensive biochemical, chemical, and genetic experiments revealed that on-target blockade of the HDAC1/2 catalytic domain mediated the differentiated phenotype.
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