title: Significant expression of thyroid transcription factor-1 in pulmonary squamous cell carcinoma detected by SPT24 monoclonal antibody and CSA-II system.
abstract: In contrast to the usefulness of thyroid transcription factor-1 (TTF-1) in distinguishing primary adenocarcinoma of the lung from metastatic lesions, TTF-1 expression in pulmonary squamous cell carcinoma is reported to be at low level and not a suitable immunohistochemical marker. We hypothesized that the highly sensitive detection system, CSA-II, can visualize even faint expression of TTF-1 in pulmonary squamous cell carcinoma. In this study, 2 commercially available clones of TTF-1 monoclonal antibody, 8G7G3/1 and SPT24, were used for staining 38 cases of pulmonary squamous cell carcinoma, in combination with the CSA-II and the conventional detection system, EnVision. The combined use of the 8G7G3/1 clone with EnVision and CSA-II showed a positive reaction in only 1 and 4 cases, respectively. The use of SPT24 clone showed positive staining in 5 cases with EnVision and in 20 of 38 cases (52.6%) with the CSA-II. Interestingly, positive staining by the SPT24-CSA-II technique of samples from tissue blocks preserved for <2 years was 73.6% compared with only 31.5% in those preserved for >2 years. In addition, a 6-month preservation of the cut sections resulted in stain fading and decreased positivity (50%), compared with freshly cut sections. We conclude that the use of the SPT24 monoclonal antibody with the CSA-II system can detect even weak expression of TTF-1 in pulmonary squamous cell carcinoma. This staining technique can potentially allow the discrimination of primary squamous cell carcinoma of the lung from metastatic lesions, especially in freshly prepared paraffin sections.
authors.affiliation: *Department of Diagnostic Pathology, Faculty of Medicine, Oita University, Yufu, Oita †Department of Bioscience, Division of Oral Pathology, Kyushu Dental College, Kitakyushu, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kashima
authors.forename: Hisashi
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Haruto
authors.initials: H
authors.lastname: Nishida
authors.forename: Motoki
authors.initials: M
authors.lastname: Arakane
authors.forename: Naomi
authors.initials: N
authors.lastname: Yada
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Daa
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000276:immunology / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000276:immunology; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000276:immunology; D009362:Neoplasm Metastasis; D009687:Nuclear Proteins / Q000276:immunology / Q000378:metabolism*; D011933:Reagent Kits, Diagnostic; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000276:immunology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D011933:Reagent Kits, Diagnostic; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors