Transcription Factor KLF4: A Potential Biomarker of Non-small Cell Lung Cancertranscription Factor KLF4: A Potential Biomarker of Non-small Cell Lung Cancer

Abstract Background Krüppel-like factor 4 (KLF4) is a member of the zinc finger transcription factor family and plays an important role in cell proliferation, differentiation, apoptosis, embryonic development, organ formation, and tumor invasion. There is little research on the clinicopathological characteristics and KLF4 expression in non-small cell lung cancer (NSCLC). Methods We conducted a retrospective study to further explore the correlation between KLF4 expression and clinicopathological features of NSCLC by immunohistochemical staining. Results This study included 81 males (52.3%), 74 females (47.7%), and 101 (65.2%) ages <65, 54 (34.8%) ages ≥65 years. A total number of 127 cases (81.9%) were adenocarcinoma, 26 cases (16.8%) were squamous cell carcinoma, and 2 cases (1.3%) were large cell carcinoma. There were 140 patients (89.7%) in T1-T2 phase and 15 patients in T3-T4 phase; 130 patients (83.9%) in N0 phase and 25 patients (16.1%) in N1-N3 phase. There were no distant metastases in 154 patients (99.4%), and only 1 patient (0.6%) was in M1 phase. In terms of clinical stage, 142 patients (91.6%) in stage I-II and 13 patients (8.4%) in stage III-IV. The number of patients with smoking history was 40 (25.8%). KLF4 expression in NSCLC tissues was significantly decreased compared with normal lung tissues (P<0.001); KLF4 expression in adenocarcinoma was lower than that in normal lung tissues (P<0.001), while there was no significant difference in quamous cell carcinoma (P=0.314). Higher KLF4 expression was significantly associated with clinicopathological features of NSCLC such as squamous cell carcinoma (P<0.001), later T stage (T3-T4 stage) (P=0.013), lymph node metastasis (P=0.011), later clinical stage (III-IV stage) (P=0.001). KLF4 expression was not associated with age (P=0.082); there was no significant difference in KLF4 expression between male and female patients with adenocarcinoma (P=0.709). It was also found that KLF4 was positively correlated with Ki-67 expression in patients with adenocarcinoma (r=0.272, P=0.002). Conclusions Aboval all, the tumor suppressor gene KLF4 might become a potential biomarker and a new therapeutic target for lung cancer patients.