Decreased Kallikrein 11 Messenger RNA Expression in Lung Cancer

BackgroundHuman kallikrein 11 (hK11) is a putative serine protease of the human kallikrein gene family. A recently developed method for measuring hK11 suggested that the hK11 level was an indicator of favorable prognosis in patients with ovarian cancer. We have investigated hK11 messenger RNA (mRNA) levels in lung cancer.Patients and MethodsThis study included 64 lung cancer cases. The hK11 mRNA levels were quantified by real-time reverse-transcriptase polymerase chain reaction using LightCycler®.ResultsThe hK11 mRNA levels were lower in tumor tissues from lung cancer (1.88 ± 6.314) compared with adjacent nonmalignant lung tissues (8.271 ± 9.002; n = 45; P = 0.0001). No significant difference was found among sex, age, clinical stages, tumor status, and lymph node metastasis. The hK11 mRNA levels were lower in moderately or poorly differentiated adenocarcinoma lung cancer (0.452 ± 1.614) compared with well-differentiated adenocarcinoma lung cancer (1.728 ± 2.829; P = 0.0281). The group with low hK11/gylceraldehyde 3-phosphate dehydrogenase levels (< 0.6) had a significantly worse prognosis compared with the group with high hK11/gylceraldehyde 3-phosphate dehydrogenase levels (> 0.6; log-rank test, P = 0.0131; Breslow-Gehan-Wilcoxon test, P = 0.0172).ConclusionCox proportional hazard regression model (multivariate analysis) indicated that pathologic stages (P = 0.0443) and low hK11 expression levels (P = 0.0469) were the prognostic factors of lung cancers. However, additional studies and a longer follow-up are needed to confirm the impact of hK11 on the biologic behavior of the tumor.