Journal article
Persistent Oxidative Stress in Vestibular Schwannomas After Stereotactic Radiation Therapy
Otology & neurotology, Vol.39(9), pp.1184-1190
10/2018
DOI: 10.1097/MAO.0000000000001935
PMCID: PMC6131037
PMID: 30106845
Abstract
Stereotactic radiation therapy is increasingly used to treat vestibular schwannomas (VSs) primarily and to treat tumor remnants following microsurgery. Little data are available regarding the effects of radiation on VS cells. Tyrosine nitrosylation is a marker of oxidative stress following radiation in malignant tumors. It is not known how long irradiated tissue remains under oxidative stress, and if such modifications occur in benign neoplasms such as VSs treated with significantly lower doses of radiation. We immunostained sections from previously radiated VSs with an antibody that recognizes nitrosylated tyrosine residues to assess for ongoing oxidative stress.
Immunohistochemical analysis.
Four VSs, which recurred after excision, were treated with stereotactic radiation therapy. Ultimately each tumor required salvage reresection for regrowth. Histologic sections of each tumor before and after radiation were immunolabeled with a monoclonal antibody specific to nitrotyrosine and compared. Two VSs that underwent reresection of a growing tumor remnant without previous radiation therapy served as additional controls.
Irradiated tumors enlarged in volume by 3.16 to 8.62 mL following radiation. Preradiation sections demonstrated little to no nitrotyrosine immunostaining. Three of four of irradiated VSs demonstrated increased nitrotyrosine immunostaining in the postradiation sections compared with preradiation tumor sections. Nonirradiated VSs did not label with the antinitrotyrosine antibody.
VSs exhibit oxidative stress up to 7 years after radiotherapy, yet these VSs continued to enlarge. Thus, VSs that grow following radiation appear to possess mechanisms for cell survival and proliferation despite radiation-induced oxidative stress.
Details
- Title: Subtitle
- Persistent Oxidative Stress in Vestibular Schwannomas After Stereotactic Radiation Therapy
- Creators
- Zachary N Robinett - Department of Otolaryngology-Head and Neck SurgeryGirish Bathla - Department of RadiologyAngela Wu - Department of PathologyJames Jason Clark - Department of Otolaryngology-Head and Neck SurgeryZita A Sibenaller - Free Radical and Radiation Biology ProgramThomas Wilson - Department of PathologyPatricia Kirby - Department of PathologyBryan G Allen - Free Radical and Radiation Biology ProgramMarlan R Hansen - Department of Neurosurgery, University of Iowa, Iowa City, Iowa
- Resource Type
- Journal article
- Publication Details
- Otology & neurotology, Vol.39(9), pp.1184-1190
- DOI
- 10.1097/MAO.0000000000001935
- PMID
- 30106845
- PMCID
- PMC6131037
- NLM abbreviation
- Otol Neurotol
- ISSN
- 1531-7129
- eISSN
- 1537-4505
- Publisher
- United States
- Grant note
- P01 CA217797 / NCI NIH HHS UL1 TR002537 / NCATS NIH HHS P30 CA086862 / NCI NIH HHS
- Language
- English
- Date published
- 10/2018
- Academic Unit
- Radiology; Molecular Physiology and Biophysics; Pathology; Radiation Oncology; Neurosurgery; Otolaryngology
- Record Identifier
- 9984047610202771
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