Fig. 5

CircZNF800 over-expression promotes while knockdown suppresses tumor growth in vivo. A CircZNF800 over-expression promotes tumor growth in vivo. WiDr cells were first transplanted subcutaneously into nude mice. The mice were divided into three groups: the vehicle group (saline) and the two groups injected either with circZNF800 RNA or circEGFP RNA (n = 3 for each group). When the tumors reached ~ 500 mm³, each group was injected four times over 10 days with 10 µg RNA for each group. Tumors were harvested on day 20 from the start of the RNA injection (schematic panel). Tumor growth rates and images of the harvested subcutaneous CRC tumors on day 20 of treatment are shown. B CircZNF800 knockdown suppresses tumor growth in vivo. Stably knockdown circZNF800 CRC cells were subcutaneously transplanted in nude mice and the tumors were harvested on day 24 (HCT-15 cells) or on day 30 (WiDr cells) post-cell injections (n = 3). Tumor growth rates and images of the harvested subcutaneous CRC tumors are shown. C Intratumoral administration of the circZNF800-knockdown lentiviral CRISPR-Cas13d constructs retards tumor growth in mice. HCT-15 or WiDr cells were subcutaneously transplanted in nude mice and the tumors were allowed to grow to an average size of ~ 300 mm³. Purified lentivirus constructs of either the control crSC, or crRNA1 or crRNA2 were injected at the tumor sites twice a week for 10 days. The tumors were allowed to continue to grow up to 16 or 22 days for WiDr or HCT-15, respectively, before harvesting for analysis (n = 2). *p < 0.05 and **p < 0.01 were relative to the crSC or vehicle-treated group