Knockdown of FOXM1 suppresses cell growth and metastasis in human laryngeal cancer via the AKT signaling pathway

NAT10 promotes the tumorigenesis and progression of laryngeal squamous cell carcinoma through ac4C modification of FOXM1 mRNA

Laryngeal squamous cell carcinoma (LSCC), is a prevalent malignant tumor, belongs to the category of head and neck tumors. N-acetyltransferase 10 (NAT10) can alter mRNA stability through N4- acetylcytidine (ac4C) modification. This study aimed to make an investigation into the role of NAT10-mediated ac4C modification in the malignant processes of LSCC cells. The NAT10 expression in LSCC tissues and cells was detected RT-qPCR and western blot. The ac4C dot blot was performed to detect ac4C level. Besides, the cell viability, migration, and invasion abilities were detected by CCK-8 and transwell assays. AcRIP-qPCR was performed to measure the abundance of ac4C on FOXM1 mRNA. RIP and Luciferase reporter assays were performed to demonstrate the interaction between NAT10 and FOXM1. Finally, the xenograft model was established to explore the role of NAT10 in vivo. NAT1 levels were significantly increased in the LSCC tissues and cells. Knockdown of NAT10 could significantly suppress the proliferation, migration, and invasion of LSCC cells. Additionally, NAT10 recognized the ac4C-modified sites in the 3'-untranslated regions (3' UTR) of forkhead box M1 (FOXM1) to enhance the ability of FOXM1 mRNA. Furthermore, FOXM1 overexpression reversed the suppressing effects of NAT10 knockdown on the proliferation, migration, and invasion of LSCC cells, according to the results of rescue assays. Finally, results of animal experiments showed that NAT10 promoted in vivo tumorigenesis of LSCC cells through upregulating FOXM1. Our current study demonstrated that NAT10-mediated ac4C modification of FOXM1 mRNA promoted the malignant processes of LSCC cells.

Ursolic Acid Accelerates Paclitaxel-Induced Cell Death in Esophageal Cancer Cells by Suppressing Akt/FOXM1 Signaling Cascade

Ursolic acid (UA), a pentacyclic triterpenoid extracted from various plants, inhibits cell growth, metastasis, and tumorigenesis in various cancers. Chemotherapy resistance and the side effects of paclitaxel (PTX), a traditional chemotherapy reagent, have limited the curative effect of PTX in esophageal cancer. In this study, we investigate whether UA promotes the anti-tumor effect of PTX and explore the underlying mechanism of their combined effect in esophageal squamous cell carcinoma (ESCC). Combination treatment with UA and PTX inhibited cell proliferation and cell growth more effectively than either treatment alone by inducing more significant apoptosis, as indicated by increased sub-G1 phase distribution and protein levels of cleaved-PARP and cleaved caspase-9. Similar to the cell growth suppressive effect, the combination of UA and PTX significantly inhibited cell migration by targeting uPA, MMP-9, and E-cadherin in ESCC cells. In addition, combination treatment with UA and PTX significantly activated p-GSK-3β and suppressed the activation of Akt and FOXM1 in ESCC cells. Those effects were enhanced by the Akt inhibitor LY2940002 and inverted by the Akt agonist SC79. In an in vivo evaluation of a murine xenograft model of esophageal cancer, combination treatment with UA and PTX suppressed tumor growth significantly better than UA or PTX treatment alone. Thus, UA effectively potentiates the anti-tumor efficacy of PTX by targeting the Akt/FOXM1 cascade since combination treatment shows significantly more anti-tumor potential than PTX alone both in vitro and in vivo. Combination treatment with UA and PTX could be a new strategy for curing esophageal cancer patients.