title: OCIA domain containing 2 is highly expressed in adenocarcinoma mixed subtype with bronchioloalveolar carcinoma component and is associated with better prognosis.
abstract: Although lung adenocarcinoma is a major cause of cancer death worldwide, details of its molecular carcinogenesis and stepwise progression are still unclear. To characterize the sequential progression from bronchioloalveolar adenocarcinoma of the lung (BAC, in situ carcinoma) to adenocarcinoma mixed subtype with BAC component polymerase chain reaction-based cDNA suppression subtractive hybridization (SSH) was carried out using two representative cases of BAC (non-invasive tumors) and adenocarcinoma mixed subtype with BAC (invasive tumors). Through differential screening, virtual reverse northern hybridization and quantitative real-time reverse-transcription-polymerase chain reaction (qRT-PCR) we selected five genes (TncRNA, OCIAD2, ANXA2, TMED4 and LGALS4) that were expressed at significantly higher levels in invasive adenocarcinoma mixed subtype with BAC than in BAC. After in situ hybridization and qRT-PCR analyses, we confirmed that only the OCIAD2 gene showed significantly higher expression in the tumor cells of invasive adenocarcinoma mixed subtype with BAC than in BAC (P = 0.026). We then carried out in situ hybridization of OCIAD2 in 56 adenocarcinoma mixed subtype with BAC component and assessed the correlation between OCIAD2 expression and clinicopathological features. In contrast to our expectation, the patients with OCIAD2 expression showed a better clinical outcome than those without OCIAD2 expression, and OCIAD2 expression showed an inverse correlation with lymphatic invasion, blood vessel invasion and lymph node metastasis. These results suggest that OCIAD2 begins to express at the progression from in situ to invasive carcinoma, and is associated with the favorable prognosis of adenocarcinoma mixed subtype with BAC component.
authors.affiliation: Department of Pathology, Institute of Basic Medical Science, Graduate School of Comprehensive Human Science, University of Tsukuba, 1-1-1 Tennoudai, Ibaraki-shi, Ibaraki, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ishiyama
authors.forename: Junko
authors.initials: J
authors.lastname: Kano
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Anami
authors.forename: Takuya
authors.initials: T
authors.lastname: Onuki
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Iijima
authors.forename: Yukio
authors.initials: Y
authors.lastname: Morisita
authors.forename: Jun
authors.initials: J
authors.lastname: Yokota
authors.forename: Masayuki
authors.initials: M
authors.lastname: Noguchi
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology*; D000368:Aged; D015152:Blotting, Northern; D018450:Disease Progression; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D017403:In Situ Hybridization; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics*; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D009363:Neoplasm Proteins; C576226:OCIAD2 protein, human