The TGF-β/Smad signaling pathway is involved in Musashi2-induced invasion and metastasis of colorectal cancer.

To identify Musashi2 as an effective biomarker regulated by the TGF-β/Smad signaling pathway for the precise diagnosis and treatment of colorectal cancer (CRC) through bioinformatic tools and experimental verification. The Cancer Genome Atlas, Timer, and Kaplan-Meier analyses were performed to clarify the expression of Musashi2 and its influence on the prognosis of CRC. Transforming growth factor beta 1 (TGF-β1) was used to activate the TGF-β/Smad signaling pathway to identify whether it could regulate the expression and function of Musashi2. Western blot analysis and quantitative PCR analyses were conducted to verify the expression of Musashi2. Cell counting kit-8 (CCK8), EdU, wound healing, and Transwell assays were conducted to reveal the role of Musashi2 in the proliferation, migration, and invasion of CRC. Musashi2 was upregulated in CRC and promoted proliferation and metastasis. TGF-β1 increased the expression of Musashi2, while the antagonist inducer of type II TGF-β receptor degradation-1 (ITD-1) decreased the expression. CCK8 and EdU assays demonstrated that inhibition of Musashi2 or use of ITD-1 lowered proliferation ability. The Transwell and wound healing assays showed that the migration and invasion abilities of CRC cells could be regulated by Musashi2. The above functions could be enhanced by TGF-β1 by activating the TGF-β/Smad signaling pathway and reversed by ITD-1. A positive correlation was found between Musashi2 and the TGF-β/Smad signaling pathway. TGF-β1 activates the TGF-β/Smad pathway to stimulate the expression of Musashi2, which promotes the progression of CRC. Musashi2 might become a target gene for the development of new antitumor drugs.