Background: Epidermal growth factor receptor (EGFR) stimulation markedly increases cyclin D1 protein expression. Recently, it has been reported that cyclin D1 expression was increased in EGFR mutant cell lines; however, the expression status of CCND1 in EGFR mutant lung cancer tissues has not been reported.
Patients and methods: We have investigated the CCND1 messenger RNA (mRNA) levels and other clinicopathologic data in 74 lung cancers. The CCND1 mRNA levels were quantified by real-time reverse-transcriptase polymerase chain reaction using LightCycler.
Results: The CCND1/GAPDH mRNA levels were significantly higher in adenocarcinoma (35.125 +/- 37.387) than in non-adenocarcinoma (15.2 +/- 24.699; P = .0158), and CCND1/GAPDH mRNA levels were not significantly different among smoking status, sex, or pathologic stage. The CCND1/GAPDH mRNA levels were significantly higher in lung cancer with EGFR mutation (39.713 +/- 41.265) than in lung cancer without EGFR mutation (21.805 +/- 29.152; P = .0338). CCND/GAPDH mRNA expression did not correlate with prognosis of lung cancer.
Conclusion: Using the LightCycler real-time reverse-transcriptase polymerase chain reaction assay, CCND1 gene expression might correlate with EGFR mutation in lung cancer. However, further studies are needed to confirm the impact of cyclin D1 for a molecular target of lung cancer.