Fig 2: KIAA1429 promoted the epithelial-mesenchymal transition of breast cancer cells(A and B) KIAA1429 endowed breast cancer cells with a mesenchymal morphology. SUM-1315 (A) and ZR-75-1 (B) cells were observed under a microscope, and then we took pictures. The right panel shows the higher magnification of the boxed areas in the left panel. (C–F) qRT-PCR and western blot assays confirmed N-cadherin, E-cadherin, and SNAIL expression after knockdown (C and E) or overexpression (E and F) of KIAA1429 in SUM-1315 and ZR-75-1 cells. Results were representative of three independent experiments and presented as the mean ± SEM; ∗p < 0.05.

Fig 3: Snail reversed the suppression of migration and metastasis induced by KIAA1429 knockdown in vitro and in vivo(A–C) KIAA1429 knockdown and the control groups of SUM-1315 and ZR-75-1 cells were transfected to overexpress SNAIL, followed by qRT-PCR and western blots examination. (D–G) Transwell experiment was performed to analyze the invasion and migration ability of SUM-1315 and ZR-75-1 cells. The lower panel of each picture showed the data of migration and invasion. Scale bars, 50 μm. Data were shown as mean ± SEM; ∗p < 0.05. (H and I) Representative images showed the sizes and numbers of lung metastasis. Metastasis nodules plot was formed by the H&E staining of lung section of the mice (n = 6). Data were shown as mean ± SEM; ∗p < 0.05. (J) Kaplan-Meier survival curves of mice in the control group, SNAIL group, and the shKIAA1429+SNAIL group(shKI+SNAIL).

Fig 4: KIAA1429 regulated SMC1A mRNA expression in breast cancer by an m6A-independent manner(A) The detection of SMC1A m6A modification level by immunoprecipitation of m6A modified RNAs in control or KIAA1429 knockdown cells followed by qRT-PCR. (B) The detection of SMC1A m6A modification level by immunoprecipitation of m6A modified RNAs in control or METTL3 knockdown cells followed by qRT-PCR. ∗p < 0.05. (C) The detection of SMC1A binding to KIAA1429 by immunoprecipitation of KIAA1429-associated RNA in control and METTL3 knockdown cells followed by qRT-PCR. (D–F) KIAA1429 overexpression (KI), KIAA1429-mut overexpression (KI-mut), and the control groups of SUM-1315 and ZR-75-1 cells were transfected, followed by qRT-PCR and western blots examination. (G–J) Transwell experiment was performed to analyze the invasion and migration ability of SUM-1315 and ZR-75-1 cells. The right panel of each picture showed the data of migration and invasion. Scale bars, 50 μm. Data were shown as mean ± SEM; ∗p < 0.05.

Fig 5: The graphic illustration of KIAA1429 modulating breast cancer invasion and metastasis via promoting EMT progress and detailed mechanism