Mechanistic insights of lenvatinib: enhancing cisplatin sensitivity, inducing apoptosis, and suppressing metastasis in bladder cancer cells through EGFR/ERK/P38/NF-κB signaling inactivation

The persistent activation of the epidermal growth factor receptor (EGFR) leads to the activation of downstream oncogenic kinases and transcription factors, resulting in tumor progression and an increased resistance to cisplatin in bladder cancer (BC) cells. Lenvatinib, an oral multikinase inhibitor, has the potential to offer therapeutic benefits as an adjuvant treatment for BC patients. The investigation into its application in bladder cancer treatment is a valuable endeavor. The primary goal of this study is to confirm the effectiveness and mechanism of lenvatinib in inhibiting the progression of BC and enhancing the anticancer efficacy of cisplatin. Materials: Three BC cell lines, namely, TSGH-8301, T24, and MB49, along with an MB49-bearing animal model, were utilized in this study.

In conclusion, the induction of apoptosis and the inhibition of EGFR/ERK/P38/NF-κB signaling are correlated with lenvatinib's ability to hinder tumor progression and enhance the cytotoxic effects of cisplatin in bladder cancer. These findings underscore the potential of lenvatinib as a therapeutic option for bladder cancer, either as a standalone treatment or in combination with cisplatin.

In vitro experiments utilizing MTT assays demonstrated that lenvatinib sensitized BC cells to cisplatin, exhibiting a synergistic effect. Flow cytometry indicated apoptotic events and signaling, presenting that lenvatinib effectively induced apoptosis and triggered extrinsic/intrinsic apoptotic pathways. In vivo studies using a mouse model of BC confirmed the antitumor efficacy of lenvatinib, demonstrating significant tumor growth suppression without inducing toxicity in normal tissues. Western blotting analysis and immunohistochemistry stain revealed EGF-phosphorylated EGFR and EGFR-mediated ERK/P38/NF-κB signaling were suppressed by treatment with lenvatinib. In addition, lenvatinib also suppressed anti-apoptotic (MCL1, c-FLIP, and XIAP) and metastasis-related factors (Twist, Snail-1, ZEB-1, ZEB-2, and MMP9) and promoted epithelial markers (E-cadherin) while reducing mesenchymal markers (N-cadherin).