Abstract
PURPOSE: The N-myc downstream regulated gene 1 (NDRG1)/Cap43 is overexpressed in multiple cancer types, including lung cancer. In this study, we investigated the expression of NDRG1/Cap43 in lung cancer tissues and in serum from 90 lung cancer patients and 60 healthy controls. MATERIALS AND METHODS: Ninety patients with pathologically confirmed primary lung cancer who underwent surgical resections were recruited for the study. From resected sections, we dissected lung tumor tissues and adjacent noncancerous tissues that were used as controls and collected patient sera for NDRG1/Cap43 expression levels. Immunohistochemical staining was applied to detect NDRG1/Cap43-positive tumor cells, and real-time quantitative-PCR (RT-PCR) was used to determine mRNA transcript levels of NDRG1/Cap43 in lung cancer tissues. Serum levels of NDRG1/Cap43 were measured by Enzyme-linked immunosorbent assays (ELISA). Data comparison between two groups was performed by independent two sample test, and comparison between more than two groups was applied by the analysis of variance (ANOVA) test. RESULTS: Compared with adjacent normal tissues, lung cancer tissues had significantly increased expression of NDRG1/Cap43 (P < 0.05). Lung adenocarcinomas also had significantly higher NDRG1/Cap43 levels than lung squamous carcinomas (P < 0.01). RT-PCR analysis showed significantly higher levels of NDRG1/Cap43 mRNA transcripts in lung cancer tissues compared with matched adjacent noncancerous tissues (P < 0.05). mRNA expression of NDRG1/Cap43 was associated with the histological pattern of lung cancer. ELISA analysis for serum NDRG1/Cap43 levels revealed significantly higher levels in lung cancer patients (358.56 ± 233.82 ng/mL) compared with healthy controls (28.83 ± 10.51 ng/mL, P < 0.001). CONCLUSIONS: NDRG1/Cap43 overexpression may be of predictive value in determining the prognosis of lung cancer patients.