Fig 2: STAT3 knockdown inhibits aerobic glycolysis in OSCC cells. (A) Glucose consumption assay was used to detect the glucose consumption in STAT3-knockdown Cal-27 and Tca8113 cells. The data showed that down-regulation of STAT3 led to lower glucose consumption in Cal-27 and Tca8113 cells. (B) Lactate production assay was used to detect the lactate production in STAT3-knockdown Cal-27 and Tca8113 cells. The data showed that down-regulation of STAT3 led to lower lactate production in Cal-27 and Tca8113 cells. (C) PKM2 mRNA levels in STAT3-knockdown Cal-27 and Tca8113 cells were examined by qRT-PCR. (D) LDHA mRNA levels in STAT3-knockdown Cal-27 and Tca8113 cells were examined by qRT-PCR. Each assay was carried out in triplicate. Results were shown as means ± SD. *P < 0.05.

Fig 3: STAT3 knockdown inhibits migration, invasion potential, and EMT in OSCC cells. (A) STAT3 mRNA levels were evaluated using qRT-PCR in SCC25, Cal-27, HSC3, Tca8113, and UM1 cells. (B) STAT3 expression was detected by qRT-PCR and Western blot after transfected with STAT3 shRNA in OSCC cells. (C) Images of the wound closure of monolayer Cal-27 and Tca8113 cells with STAT3 knockdown at the time point of 0 and 24 h are presented on the left. Quantitative results are illustrated on the right. (D) The effect of STAT3 knockdown on OSCC cells invasion were determined by Transwell assay with Matrigel, and the representative images are on the left. Quantitative results are illustrated on the right. (E) The effects of Cal-27-STAT3 knockdown on expressions of EMT markers, E-cadherin, N-cadherin, ß-catenin, and Vimentin, were measured using qRT-PCR and Western blot. ß-actin was used as a loading control. (F) Flow cytometry was used to examine the percentage of apoptotic cells in Cal-27 cells with STAT3 knockdown and scramble control cells. All assays were carried out in triplicate. Results were shown as means ± SD. *P < 0.05.

Fig 4: Upregulation of STAT3 partially rescues cell proliferation and invasion inhibited by miR-411 overexpression in cervical cancer cells. miR-411 mimic was transfected into HeLa and SiHa cells, either with or without pcDNA3.1-STAT3. (A) The protein expression level of STAT3 was determined by Western blotting analysis. *p < 0.05 compared with miR-NC. #p < 0.05 compared with miR-411 mimics + pcDNA3.1-STAT3. (B) CCK-8 and (C) Transwell invasion assays were conducted to examine cell proliferation and invasion in indicated cells. *p < 0.05 compared with miR-NC. #p < 0.05 compared with miR-411 mimics + pcDNA3.1-STAT3.

Fig 5: EMT induced by TGFβ1 in HepG2 cells. (A) TGFβ1 induced HepG2 cell scattering. Cells were incubated with 10 μM TGFβ1 for 48 h. Representative images were captured at a magnification of ×200 using an Eclipse TE2000-U inverted microscope. Scale bar, 10 μm. (B–D) qPCR and western blot analysis of EMT markers in HepG2 cells after treatment with 10 μM TGFβ1 for 48 h. Data are presented as mean ± standard deviation of 3 independent experiments. *P<0.05 vs. control. (E and F) Western blot analysis revealed that TGFβ1 promoted the expression of JAK, p-JAK, STAT3, and p-STAT3. Data are presented as mean ± standard deviation of three independent experiments. *P<0.05 vs. control. TGFβ1, transforming growth factor β1; con, control; EMT, epithelial-to-mesenchymal transition; qPCR, quantitative polymerase chain reaction; JAK, Janus kinase; STAT3, signal transducer and activator of transcription 3.