Lung cancer is one of the most common malignancies worldwide, resulting in approximately 1.6 million deaths annually. Cancer immune surveillance has been found to play a significant role in lung cancer and may be associated with its prognosis. KLRK1, encoding NKG2D, is a homodimeric lectin-like receptor. However, studies investigating KLRK1 as a lung cancer biomarker are limited. Here, researchers downloaded data from the TCGA database, including patient clinical characteristics and KLRK1 RNAseq information. A total of 1,019 lung cancer patients (407 female and 611 male) were included. The study demonstrated that KLRK1 expression is lower in tumors than in normal tissues. KLRK1 expression is associated with sex, histological grade, stage, T stage, and vital status. Patients with high KLRK1 expression have prolonged overall and recurrence-free survival. Analysis of overall survival in the subgroups of lung adenocarcinoma, stage I/II, elderly patients, and male patients, as well as recurrence-free survival in the subgroups of lung adenocarcinoma, stage I/II, elderly patients, and male patients, revealed significant prognostic value for KLRK1. Lung adenocarcinoma patients with high KLRK1 expression have improved overall and recurrence-free survival. In vitro studies have shown that KLRK1 can inhibit tumor cell proliferation and migration. KLRK1 is an independent prognostic factor, and high KLRK1 expression is associated with improved overall and recurrence-free survival. KLRK1 may serve as a prognostic biomarker for lung adenocarcinoma.
The researchers overexpressed KLRK1 in lung cancer A549 cells to investigate its effects on cells. CCK-8 assays showed that cell proliferation was significantly inhibited in KLRK1-overexpressing cells (Figure 1A). Compared with the control group, the percentage of dead cells (live/dead staining) in KLRK1-overexpressing cells increased (Figure 1B). KLRK1 also reduced the migration distance of cancer cells (Figures 1C, D).
Figure 1. The effect of KLRK1 in lung cancer A549 cell lines. (Zhang Y, et al., 2022)