Quaking 5 suppresses TGF‐β‐induced EMT and cell invasion in lung adenocarcinoma

A

A549 and H1299 cells were co‐transfected with QKI‐5 and ORF‐only of TGFβR1 and then subjected to Western blot assays for detection of QKI‐5 and TGFβR1 expression.

B

After serum starvation for 24 h, the above‐treated A549 and H1299 cells were stimulated with or without TGF‐β1 (5 or 10 ng/ml) for 24 h. The expression of p‐SMAD3, SMAD3, and EMT markers (N‐cadherin and Snail) was determined using Western blot. β‐actin was used as an internal control.

C–F

In the presence or absence of TGF‐β1, the migratory and invasive capabilities of above‐treated A549 and H1299 cells were evaluated by Transwell assays as described in Fig 4G–J. Migrated and invasive cells were stained and counted under a light microscope. Data are shown as the mean ± SD of n = 3 technical replicates. **P < 0.01 and ***P < 0.001 by unpaired Student's t‐test. Scale bar, 100 μm.

G, H

qRT–PCR analysis of TGFβR1 mRNA in 61 LUAD tissues and matched paracarcinoma tissues (G) and T/N mRNA expression of TGFβR1 in 61 paired LUAD tissues (H). T, LUAD tissues; N, paracarcinoma tissues. Y axis represents the log₁₀‐transformed fold change of mRNA expression of TGFβR1. Central dotted line of the violin plot represents median, and upper and lower dotted line represents quartile (G). ****P < 0.0001 by unpaired Student's t‐test.

I

Correlation between QKI‐5 and TGFβR1 mRNA expression in 61 paired LUAD tissues. X and y axes represent the log10‐transformed fold change of T/N expression ratios of QKI‐5 and TGFβR1 mRNA, respectively. P < 0.0001 by Pearson's correlation test.

J

Kaplan–Meier survival curves (http://kmplot.com/analysis/) of LUAD patients (n = 865) with high or low expression levels of TGFβR1. The log‐rank test was used to compare the difference between two groups.

Figure 6. QKI‐5 inhibits TGF‐β‐induced EMT and cell invasion via a TGFβR1‐dependent manner.