Am J Transl Res. 2021 Feb 15;13(2):672-683.eCollection 2021.

POU2F1 induces the immune escape in lung cancer by up-regulating PD-L1

Fei Li  1 Tianyi Wang  2 Yinpeng Huang  3 Affiliations

Free PMC article


Purpose: The aim was to research the POU2F1 related genes and mechanism during the progress of immune escape of lung cancer.

Methods: Lung cancer cell lines (H1993, HCC827, A549, H2228, H3122 and H1975) and Human normal lung epithelial cell line (BEAS-2B) were involved in this study. Overexpression or knockdown of POU2F1 was processed in lung cancer cells. POU2F1, PD-L1 and CRK expression in cells were detected by WB and RT-PCR. Flow cytometry and immunofluorescence was used to detect PD-L1 expression on the cell surface. Luciferase reporter detected the promoter activity of CRK. C57BL/6 mice models with knocked down of of POU2F1 were constructed. After tumor formation, anti-PD-1 was administered to detect tumor suppressing ability. IHC assay showed the number of intratumoral CD3+, CD8+, GranzB+ T cells.

Results: POU2F1 and PD-L1 were positively correlated in lung cancer cell lines. Overexpression of POU2F1 promoted the expression level of PD-L1 in lung cancer cells. POU2F1 transcription activated the expression of CRK, and further promoted the expression of PD-L1. Knockdown of POU2F1 promoted the efficacy of Anti-PD-1. In addition, tumor growth ability decreased after POU2F1 was knocked down. Cytotoxic effector cytokines levels, tumor suppressive chemokines and interleukin increased, while IL17a level decreased when POU2F1 was knocked down.

Conclusion: POU2F1 activates the expression of CRK, further promotes the expression of PD-L1, and finally improves the immune escape in lung cancer.

Keywords: Lung cancer; PD-L1; POU2F1; immune escape.