Background: Sonic Hedgehog (SHh) signaling pathway plays a critical role in cell proliferation, apoptosis, and tumor angiogenesis in various types of malignancies including colorectal cancer (CRC). Qingjie Fuzheng Granules (QFG) is a traditional Chinese medicinal formula, which has been clinically used in various cancer treatments, including CRC. In this study, we explored the potential molecular mechanisms of QFG treatment effects on CRC via the SHh pathway.
Methods: A CRC HCT-116 xenograft mouse model was utilized for all experiments. Mice were treated with intra-gastric administration of 1 g/kg of QFG or saline 6 days a week for 28 days (4 weeks). Body weight, length and shortest diameter of the tumor were measured every 3 days. At the end of the treatment, the tumor weight was measured. TUNEL staining assays were used to detect tumor apoptosis. Western blot and immunohistochemistry (IHC) assays were used to detect the expression of relative proteins.
Results: In our results, QFG inhibited the increase of tumor volume and weight, and exhibited no impact on mouse body weight. Furthermore, QFG significantly decreased the expression of SHh, Smo and Gli proteins, indicating the action of SHh signaling. Consequently, the expression of pro-proliferative survivin, Ki-67, Cyclin-D1 and CDK4 were decreased and expression of anti-proliferative p21 was increased. The pro-apoptotic Bax/Bcl-2 ratio, cle-caspase-3 and TUNEL-positive cell percentage in tumor tissues were increased. Meanwhile, the pro-angiogenic VEGF-A and VEGFR-2 expression was down-regulated.
Conclusions: QFG inhibited CRC cell proliferation and promoted CRC cell apoptosis and tumor angiogenesis in vivo through the suppression of SHh pathway, suggesting that QFG could be a potential therapeutic drug for CRC.
Keywords: Qingjie Fuzheng Granules (QFG); angiogenesis; apoptosis; colorectal cancer (CRC); proliferation.
2020 Journal of Gastrointestinal Oncology. All rights reserved.