Biomaterial Database

[Radiosensitizing effect of hyperfractionated radiation]. 2004

Agnes Drahos, and Annamária Dám, and Zsolt Oreg

Országos "Frédéric Joliot-Curie" Sugárbiológiai és Sugáregészségügyi Kutató Intézet, Budapest 1221, Hungary. drahos@hp.osski.hu

To determine whether hyperfractionated treatment has benefits in the radiation therapy, two melanoma cell lines were irradiated with eight 0.5 Gy fractions as well as one single 4 Gy in vitro. The radiation was performed in air and in hypoxia as well. Cells were also irradiated in the presence of dibromodulcitol, a bifunctional alkylating agent with a weak radiosensitizer effect. The aim of the study was to examine whether hyperfractionation can influence the radiosensitizing effect of the bioreductive agent. Survival of the cells was determined immediately and 24 hours after various treatments by cell counting in hemocytometer and clonogenic assay. The number of the apoptotic cells was determined by the TUNEL assay and was followed up to 72 hours after treatment. Hypoxic cells had higher sensitivity than normoxic cells after 0.5 Gy irradiation. Radiosensitizing enhancement of DBD was higher with fractionated irradiation. The number of the apoptotic cells was significantly higher after hyperfractionated treatments than after single dose treatment combinations. Our results showed the significance of the hyperfractionated irradiation with 0.5 Gy per fraction in vitro.

UI	MeSH Term	Description	Entries
D008545	Melanoma	A malignant neoplasm derived from cells that are capable of forming melanin, which may occur in the skin of any part of the body, in the eye, or, rarely, in the mucous membranes of the genitalia, anus, oral cavity, or other sites. It occurs mostly in adults and may originate de novo or from a pigmented nevus or malignant lentigo. Melanomas frequently metastasize widely, and the regional lymph nodes, liver, lungs, and brain are likely to be involved. The incidence of malignant skin melanomas is rising rapidly in all parts of the world. (Stedman, 25th ed; from Rook et al., Textbook of Dermatology, 4th ed, p2445)	Malignant Melanoma,Malignant Melanomas,Melanoma, Malignant,Melanomas,Melanomas, Malignant
D011879	Radiotherapy Dosage	The total amount of radiation absorbed by tissues as a result of radiotherapy.	Dosage, Radiotherapy,Dosages, Radiotherapy,Radiotherapy Dosages
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D015687	Cell Hypoxia	A condition of decreased oxygen content at the cellular level.	Anoxia, Cellular,Cell Anoxia,Hypoxia, Cellular,Anoxia, Cell,Anoxias, Cell,Anoxias, Cellular,Cell Anoxias,Cell Hypoxias,Cellular Anoxia,Cellular Anoxias,Cellular Hypoxia,Cellular Hypoxias,Hypoxia, Cell,Hypoxias, Cell,Hypoxias, Cellular
D017209	Apoptosis	A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, i.e., DNA FRAGMENTATION. It is genetically programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.	Apoptosis, Extrinsic Pathway,Apoptosis, Intrinsic Pathway,Caspase-Dependent Apoptosis,Classic Apoptosis,Classical Apoptosis,Programmed Cell Death,Programmed Cell Death, Type I,Apoptoses, Extrinsic Pathway,Apoptoses, Intrinsic Pathway,Apoptosis, Caspase-Dependent,Apoptosis, Classic,Apoptosis, Classical,Caspase Dependent Apoptosis,Cell Death, Programmed,Classic Apoptoses,Extrinsic Pathway Apoptoses,Extrinsic Pathway Apoptosis,Intrinsic Pathway Apoptoses,Intrinsic Pathway Apoptosis
D045744	Cell Line, Tumor	A cell line derived from cultured tumor cells.	Tumor Cell Line,Cell Lines, Tumor,Line, Tumor Cell,Lines, Tumor Cell,Tumor Cell Lines
D049109	Cell Proliferation	All of the processes involved in increasing CELL NUMBER including CELL DIVISION.	Cell Growth in Number,Cellular Proliferation,Cell Multiplication,Cell Number Growth,Growth, Cell Number,Multiplication, Cell,Number Growth, Cell,Proliferation, Cell,Proliferation, Cellular
D019583	Dose Fractionation, Radiation	Administration of the total dose of radiation (RADIATION DOSAGE) in parts, at timed intervals.	Radiotherapy Dose Fractionation,Dose Fractionation, Radiotherapy,Radiation Dose Fractionation,Dose Fractionations, Radiotherapy,Fractionation, Radiation Dose,Fractionation, Radiotherapy Dose,Fractionations, Radiotherapy Dose,Radiotherapy Dose Fractionations
D020287	In Situ Nick-End Labeling	An in situ method for detecting areas of DNA which are nicked during APOPTOSIS. Terminal deoxynucleotidyl transferase is used to add labeled dUTP, in a template-independent manner, to the 3 prime OH ends of either single- or double-stranded DNA. The terminal deoxynucleotidyl transferase nick end labeling, or TUNEL, assay labels apoptosis on a single-cell level, making it more sensitive than agarose gel electrophoresis for analysis of DNA FRAGMENTATION.	Nick-End Labeling, In Situ,TUNEL,In Situ Nick End Labeling,In Situ Nick End Labelling,In Situ Nick End-Labeling,In Situ Nick End-Labelling,In Situ Nick-End Labelling,Nick End-Labeling, In Situ,Nick End-Labelling, In Situ,Nick-End Labelling, In Situ,Nick End Labeling, In Situ,Nick End Labelling, In Situ