Radiotherapy plays a key role in the treatment of many tumors. It is difficult to determine what fraction of tumor cells survives after treatment with ionizing radiation. A convenient and sensitive biochemical assay could be efficacious in determining the potential success of radiotherapy. Since telomerase activity is frequently associated with the malignant phenotype, we sought to determine whether a correlation existed between ionizing radiation-induced cell killing and telomerase activity. We evaluated telomerase activity in two telomerase-positive and one telomerase-negative human cell line exposed to ionizing radiation. Telomerase activity was determined using a PCR-based telomeric repeat amplification protocol coupled with ELISA. We found ionizing radiation treatment to decrease the telomerase activity (in plateau phase cells of RKO, HeLa; and growing cells of RKO) in a dose-dependent manner, which correlated with cell death in in vitro tests as well as during tumor regression in nude mice. In contrast, growing HeLa cells after 24 h postradiation treatment showed an increase in telomerase activity, but there was no increase in the levels of mRNA of hTERT. To assess the sensitivity of the telomerase activity assay, we performed mixing experiments of HeLa and AG1522 cell extracts. These studies showed that telomerase activity could be detected in lysate equal to a single HeLa cell when mixed with 10,000 AG1522 cells. Our results indicate that even a few surviving neoplastic cells can be detected by telomerase activity assay. Therefore, detection of telomerase activity may be a useful monitor of radiotherapeutic efficacy and an early predictor of outcome.
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http://dx.doi.org/10.1096/fasebj.13.9.1047 | DOI Listing |
Hum Cell
January 2025
Department of Tumor Pathology, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuoka-Shimoaizuki, Eiheiji, Fukui, 910-1193, Japan.
Only a few human ovarian endometrioid carcinoma cell lines are currently available, partly due to the difficulty of establishing cell lines from low-grade cancers. Here, using a cell immortalization strategy consisting of i) inactivation of the p16-pRb pathway by constitutive expression of mutant cyclin-dependent kinase 4 (R24C) (CDK4) and cyclin D1, and ii) acquisition of telomerase reverse transcriptase (TERT) activity, we established a human ovarian endometrioid carcinoma cell line from a 46-year-old Japanese woman. That line, designated JFE-21, has proliferated continuously for over 6 months with a doubling time of ~ 55 h.
View Article and Find Full Text PDFComput Biol Med
January 2025
Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey; Center for Neuroradiological Applications and Research, Acibadem University, Istanbul, Turkey.
Background: Preoperative and noninvasive detection of isocitrate dehydrogenase (IDH) and telomerase reverse transcriptase gene promoter (TERTp) mutations in glioma is critical for prognosis and treatment planning. This study aims to develop deep learning classifiers to identify IDH and TERTp mutations using proton magnetic resonance spectroscopy (H-MRS) and a one-dimensional convolutional neural network (1D-CNN) architecture.
Methods: This study included H-MRS data from 225 adult patients with hemispheric diffuse glioma (117 IDH mutants and 108 IDH wild-type; 99 TERTp mutants and 100 TERTp wild-type).
Exp Hematol Oncol
January 2025
Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
Telomeres and telomerase play crucial roles in the initiation and progression of cancer. As biomarkers, they aid in distinguishing benign from malignant tissues. Despite the promising therapeutic potential of targeting telomeres and telomerase for therapy, translating this concept from the laboratory to the clinic remains challenging.
View Article and Find Full Text PDFJ Orthop Translat
January 2025
Department of Orthopaedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.
Background: Bone marrow inflammaging is a low-grade chronic inflammation that induces bone marrow aging. Multiple age-related and inflammatory diseases involve bone marrow inflammaging. Whether common pathological pathways exist in bone marrow inflammaging remains unclear.
View Article and Find Full Text PDFTelomere biology disorders (TBDs) are inherited conditions associated with multisystem manifestations. We describe clinical and functional characterisation of a novel TERT variant. Whole-genome sequencing was performed along with single length analysis ().
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