Fig. 3

Downregulation of IMPDH2 inhibits proliferation, migration and invasion of CRC cells and suppresses tumour growth in the nude mouse model. (a and b) Knockdown of IMPDH2 was confirmed at the protein and mRNA level in HCT116 and SW620 cells by western blotting and qPCR. Mean ± SD (n = 3). (c and d) IMPDH2 knockdown inhibited proliferation ability of HCT116 and SW620 cells as determined by colony formation and CCK8 assays. Mean ± SD (n = 3). (e) IMPDH2 knockdown significantly suppressed the invasion ability of HCT116 and SW620 cells by the transwell assay. Representative photographs (left) and quantification (right) are shown. The number of cells that invaded through the extracellular matrix after 24 h was counted in five randomly selected microscopic fields. Mean ± SD (n = 3). Scale bars, 100 μm. (f) IMPDH2 knockdown significantly inhibited the migration ability of HCT116 and SW620 cells by cell wound healing assay. Images were taken at 0 h, 24 h, 48 h and 72 h. The number of migrated cells was counted (right). Mean ± SD (n = 3). Scale bars, 200 μm. (g) IMPDH2 silencing inhibited tumour growth in the nude mouse model by xenograft growth assay. Gross observation of xenograft tumour size (left). Statistical chart of a xenograft tumour volume and weight (right). (h) H&E and Ki-67 staining of a xenograft tumour. The percent of Ki-67 positive cells was shown (right). Scale bars, 50 μm and 20 μm. (i) Tumor cells were injected into nude mice through the tail vein to evaluate the lung homing potential of cells. Gross observation of lung metastases (left). H&E staining of lung metastatic nodules (right). Scale bars, 50 μm and 20 μm. (j) Kaplan-Meier survival analyses (log-rank) for the mice with HCT116/shIMPDH2 cells versus HCT116/Control cells were performed. Each error bar represents the mean ± SD of three replicate samples. *P < 0.05; **P < 0.01