title: Expression of cyclooxygenase-2 and DNA topoisomerase II alpha in precancerous and cancerous lesions of the oral mucosa.
abstract: The involvement of cyclooxygenase (COX)-2 in oral carcinogenesis and outcome of the patients is not fully understood. To determine whether COX-2 expression could serve as an indicator for them, we examined the expression of COX-2 and DNA topoisomerase (DNA-Topo) II alpha as an index of cell proliferating activity in precancerous and cancerous lesions of the oral mucosa. A 164 samples composed of 60 intraepithelial dysplasias (IEDs), 12 carcinomas in situ (CISs), 72 squamous cell carcinomas (SCCs) including 12 early invasive SCCs, 10 undifferentiated carcinomas (UCs), and 10 epithelial hyperplasias (EHPs) in the oral mucosa were examined immunohistochemically for COX-2 and DNA-Topo II alpha. Normal squamous epithelium as the control showed no COX-2 expression, whereas 41% of IEDs, 67% of CISs, 74% of SCCs, and 86% of UCs demonstrated increased COX-2 expression with elevated DNA-Topo II alpha labeling index (LI). High COX-2 expression was also observed in 61% of EHPs, but DNA-Topo II alpha LI was very low. Increased expression of COX-2 protein correlated with elevated DNA-Topo II alpha LI, indicating that COX-2 may contribute to malignant transformation and tumor growth. These two enzyme activities were increased as T, N, and M categories and stages proceeded. The patients with high expression of both COX-2 and DNA-Topo II alpha showed poor prognosis. Our results suggested that COX-2 expression become a possible indicator in oral carcinogenesis and may reflect the outcome of the patients.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Segawa
authors.forename: Kazunari
authors.initials: K
authors.lastname: Sakurai
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Kishimoto
authors.forename: Kazuki
authors.initials: K
authors.lastname: Takaoka
authors.forename: Kazuma
authors.initials: K
authors.lastname: Noguchi
authors.forename: Susumu
authors.initials: S
authors.lastname: Hashitani
authors.forename: Seiichi
authors.initials: S
authors.lastname: Hirota
authors.forename: Masahiro
authors.initials: M
authors.lastname: Urade
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000473:pathology; D049109:Cell Proliferation; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000201:enzymology / Q000473:pathology; D009062:Mouth Neoplasms / Q000201:enzymology* / Q000473:pathology; D009363:Neoplasm Proteins / Q000378:metabolism*; D011230:Precancerous Conditions / Q000201:enzymology* / Q000473:pathology; D016019:Survival Analysis
chemical_list: D000951:Antigens, Neoplasm; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D051546:Cyclooxygenase 2; D004250:DNA Topoisomerases, Type II