title: Down-regulation of MicroRNA-126 in Glioblastoma and its Correlation with Patient Prognosis: A Pilot Study.
abstract: Glioblastoma is the most common primary malignant tumor of the adult human brain. Although microRNA-126 (miR-126) has been reported to exhibit expression abnormalities in various types of cancer, to date very few studies have examined changes in miR-126 level in glioblastoma. In this pilot study, we investigated the changes in miR-126 expression in newly-dissected primary glioblastoma to explore possible roles of miR-126 in patient prognosis. Total RNA was extracted from tumoral and adjacent non-cancerous tissues from 14 patients' paired frozen specimens. Using an established quantitative reverse transcriptase-PCR protocol, the levels of miR-126 in glioblastoma and adjacent non-tumor brain tissues were compared against small nucleolar RNA U48 (RNU48) as a reference gene. The expression of miR-126 in glioblastoma samples was significantly lower than in paired non-tumoral controls (p<0.05). Importantly, age-adjusted analyses suggest that glioblastoma patients with higher relative intratumoral miR-126 expression (i.e. 53-79% relative to that of the control tissue; n=7) had significantly improved survival duration than patients whose miR-126 levels were lower (i.e. 12-48%, n=7; stratified log-rank analysis p=0.011 when the dividing threshold was set at ≥51%; total: n=14, male: 8; female: 6). Thus, intraglioblastoma miR-126 may be down-regulated relative to normal tissue and patients with less down-regulation of intratumoral miR-126 expression could have improved postsurgical prognosis. Future clinical studies with larger sample sizes should be performed to validate this observation.
authors.affiliation: Department of Neurosurgery, CHA University, Bundang CHA Medical Center, Gyeonggido, Republic of Korea.|Departments of Physical Medicine & Rehabilitation and Neurosurgery, Harvard Medical School, Spaulding Rehabilitation Hospital and Brigham & Women's Hospital, Boston, MA, U.S.A.
authors.forename: In Bo
authors.initials: IB
authors.lastname: Han
authors.affiliation: Department of Neurosurgery, Brain Tumor Center, and Brain Research Institute, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Minsoo
authors.initials: M
authors.lastname: Kim
authors.affiliation: Department of Biomedical Science, CHA University, Gyeonggido, Republic of Korea.
authors.forename: Soo Hong
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Neurology, CHA University, Bundang CHA Medical Center, Gyeonggido, Republic of Korea.
authors.forename: Jin Kwon
authors.initials: JK
authors.lastname: Kim
authors.affiliation: Department of Pathology, Severance Hospital, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Se Hoon
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Brain Tumor Center, and Brain Research Institute, Yonsei University Health System, Seoul, Republic of Korea yang_teng@hms.harvard.edu changjh@yuhs.ac.
authors.forename: Jong Hee
authors.initials: JH
authors.lastname: Chang
authors.affiliation: Departments of Physical Medicine & Rehabilitation and Neurosurgery, Harvard Medical School, Spaulding Rehabilitation Hospital and Brigham & Women's Hospital, Boston, MA, U.S.A. yang_teng@hms.harvard.edu changjh@yuhs.ac.|Division of SCI Research, Veterans Affairs Boston Healthcare System, West Roxobury, MA, U.S.A.
authors.forename: Yang D
authors.initials: YD
authors.lastname: Teng
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000235:genetics*; D015536:Down-Regulation; D005260:Female; D005909:Glioblastoma / Q000235:genetics*; D006801:Humans; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D010865:Pilot Projects; D011379:Prognosis
chemical_list: C527111:MIRN126 microRNA, human; D035683:MicroRNAs
keywords: Glioblastoma; RT-PCR; cancer stem cell; miR-126; microRNA; prognosis