title: Sirt1 is a tumor promoter in lung adenocarcinoma.
abstract: Sirtuin 1 (Sirt1) is a nicotinamide adenine dinucleotide-dependent class III histone deacetylase. It reportedly can repress cellular apoptosis and senescence to affect DNA repair, stress response and aging. Notably, previous data have indicated that Sirt1 is both a tumor promoter and a tumor suppressor in tumorigenesis. However, Sirt1 expression in primary lung adenocarcinoma remains unknown. Immunohistochemical staining was performed to investigate Sirt1 expression in cancer cells in 125 consecutive resected cases of primary lung adenocarcinoma. Sirt1 expression was found to be increased in 26 (20.8%) of the 125 cases, which correlated significantly with five clinicopathological factors: Ki67 index, hypoxia-inducible factor 1 (HIF1) molecule expression, tumor-node-metastasis (TNM) classification, pulmonary vein invasion and lymphatic duct invasion. In the Sirt1-positive expression group, Sirt1 expression correlated with a higher Ki67 index and higher TNM classification, particularly for lymph node invasion and metastasis, and with a higher number of pulmonary vein invasion and lymphatic duct invasion. Additionally, a negative correlation was identified between HIF1-positive expression and Sirt1-negative expression. These results indicate that Sirt1 overexpression plays a promotional role in tumorigenesis and is closely associated with invasion and metastasis and, thus, it may be associated with prognosis.
authors: Division of Molecular Medicine and Medical Genetics, Department of Pathology, Kobe University Graduate School of Medicine, Kobe, Hyogo 650-0017, Japan.
authors: Xue
authors: X
authors: Chen
authors: Division of Thoracic Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Hyogo 650-0017, Japan.
authors: Daisuke
authors: D
authors: Hokka
authors: Division of Thoracic Surgery, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Hyogo 650-0017, Japan.
authors: Yoshimasa
authors: Y
authors: Maniwa
authors: Department of Pathology, Nara Medical University, Kashihara, Nara 634-8522, Japan.
authors: Chiho
authors: C
authors: Ohbayashi
authors: Department of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Hyogo 650-0017, Japan.
authors: Tomoo
authors: T
authors: Itoh
authors: Division of Molecular Medicine and Medical Genetics, Department of Pathology, Kobe University Graduate School of Medicine, Kobe, Hyogo 650-0017, Japan.
authors: Yoshitake
authors: Y
authors: Hayashi
keywords: apoptosis; cellular senescence; hypoxia-inducible factor 1; lung adenocarcinoma; sirtuin 1