Fig. 1

The expression of plek2 is related to CAFs based on GEPIA A: PLEK2 expression is present in LUAD (including 483 tumor samples and 347 normal samples) and LUSC (including 486 tumor samples and 338 normal samples). The red box chart represents tumor tissue, while the gray box chart represents normal tissue. The vertical axis represents the logarithmic value of PLEK2 per million transcripts [log2 (PLEK2 TPM)]. B: The relative expression of PLEK2 in different pathological stages of lung cancer (LUAD+LUSC) showed significant differences (F = 4.73, P = 0.002 8). The vertical axis represents the logarithmic value of the copy number of the PLEK2 transcript [log2 (PLEK2 TPM)]. C: The expression of PLEK2 (log2 PLEK2 TPM) in lung cancer (LUAD+LUSC) was positively correlated with the expression of α-SMA (log2-SMA TPM) (R = 0.24, P<0.001). D: The expression of PLEK2 (log2 PLEK2 TPM) in lung cancer (LUAD+LUSC) was positively correlated with the expression of FAP (log2 FAP TPM) (R = 0.15, P<0.001). TPM stands for every million transcripts. E: Using the TCGA data set of lung cancer patients (LUAD+LUSC), the correlation between the expression of PLEK2 and the overall survival was analyzed by GEPIA. Patients were divided into high (red, n = 481) and low (blue, n = 481) gene expression levels by using the median cut-off value, and the log-rank P = 0.035 was displayed, indicating that the difference was statistically significant."

Fig. 2

PLEK2 overexpression promotes EMT in lung cancer cells A: The expression of PLEK2, E-cadherin and vimentin in H1299 cells transfected with Vector control and PLEK2 overexpression lentivirus was analyzed by protein blot. B: H-E staining of lung tissue and quantitative analysis of metastatic nodules. C: Immunohistochemical analysis of α-SMA in lung tissue metastases. IOD: Integral optical density. ***: P<0.001, compared with Vector group."

Tab. 1

miRNA analysis of significantly different expression in PLEK2 up-regulated lung cancer cells and their exosomes"

Fig. 3

PLEK2 overexpression upregulates miR-196a expression in lung cancer cells and their exosomes ***: P<0.001, compared with the Vector group or Vector_exo group."

Fig. 4

Exosomes miR-196a derived from tumor cells are taken up by fibroblasts and promote the activation of CAFs A: Transmission electron micrographs of Vector_exo and PLEK2_exo (scale = 100 nm). B: Western blot analysis of the expression of CD9, CD63, CD81 and calnexin in exosomes. C: After co-culture for 48 h, the internalization of Vector_exo and PLEK2_exo labeled with PKH26 by MRC-5 cells was examined by confocal microscope. D: RT-qPCR analysis of miR-196a, α-SMA, FAP in MRC-5 cells treated with Vector_exo, PLEK2_exo. E, F: Western blot and RT-qPCR were used to determine the protein and mRNA levels of α-SMA and FAP in MRC-5 cells transfected with miR-196a mimetic (miR-196a) and NC. G, H: Western blot and RT-qPCR were used to determine the protein and mRNA levels of α-SMA and FAP in MRC-5 cells transfected with miR-196a inhibitors (si-miR-196a#1 and si-miR-196a#) and control (si-NC). *: P<0.05, compared with the Vector_exo group; **: P<0.01, compared with the Vector_exo group or si-NC group; ***: P<0.001, compared with the Vector_exo group, NC group or si-NC group."

Fig. 5

CAFs activation promotes the invasion and metastasis of lung cancer A: The metastatic and invasive ability of H1299 cells treated with miR-196a-CM was determined by transwell test. B: the expression level of EMT-related proteins in H1299 cells treated with miR-196a-CM. C: The metastatic and invasive ability of H1299 cells co-cultured with Vector_exo-CM and PLEK2_exo-CM was determined by transwell test. D: The expression level of EMT-related proteins in H1299 cells co-cultured with Vector_exo-CM and PLEK2_exo-CM. **: P<0.01, compared with Vector_exo-CM group; ***: P<0.001, compared with NC-CM group or Vector_exo-CM group."