The E2F1-KIF14 axis drives focal adhesion formation and promotes colorectal cancer metastasis

Abstract

Kinesin family member 14 (KIF14) has been implicated in the progression of multiple cancer types, yet its role in colorectal cancer (CRC) metastasis remains undefined. Here, we assesse KIF14 expression in CRC specimens and explore its clinical and functional significance. KIF14 upregulation is frequently observed in CRC tissues and is correlated with advanced tumor stage and reduced overall survival. Functional assays reveal that KIF14 depletion in CRC cells inhibits migration, invasion, and in vivo metastatic colonization, whereas KIF14 overexpression induces the opposite effects. Transcriptomic and pathway enrichment analyses reveal that KIF14 functions as a critical regulator of focal adhesion and cell-matrix adhesion signaling. This finding is further supported by experimental evidence showing that KIF14 overexpression promotes focal adhesion assembly, whereas KIF14 knockdown disruptes this process. Mechanistically, we demonstrate that KIF14 binds directly to the focal adhesion protein vinculin and mediates its delivery to the leading edge of migrating cells. Moreover, bioinformatics prediction and chromatin immunoprecipitation confirm that E2F1 directly binds the KIF14 promoter to drive its transcription. Rescue experiments reveal that ectopic KIF14 expression restores the prometastatic phenotypes suppressed by E2F1 silencing, indicating that the effects of E2F1 are mediated by the E2F1-KIF14 axis. Collectively, our findings reveal a novel E2F1-KIF14-vinculin signaling axis that drives CRC metastasis by modulating focal adhesion dynamics, highlighting KIF14 as a potential therapeutic target.

1. Introduction

Colorectal cancer (CRC), a malignancy originating from the mucosal epithelium, accounted for 1.9 million new cancer cases and 903,000 related deaths in 2022 (IARC), ranking the third in incidence and second in mortality worldwide [1]. Two alarming trends have recently been observed for CRC: a dramatic surge in early-onset cases, with the incidence among individuals under 50 years rising by 50% over three decades, and an aggressive metastatic propensity [2,3]. Notably, 20% of patients present with distant metastases at initial diagnosis, whereas over 50% develop metastases during disease progression [3]. The dismal five-year survival rate of patients with metastatic CRC (less than 15%) underscores the critical need to decipher the molecular mechanisms driving tumor dissemination.

Kinesin family member 14 (KIF14), a microtubule-directed motor protein belonging to the kinesin-3 family, is increasingly recognized for its multifaceted role in cancer biology. Its distinctive structural features, including an N-terminal motor domain for ATP-dependent movement, coiled-coil domains facilitating dimerization, and a neck-linker region for directional transport, suggest that KIF14 may act as a critical regulator of cytoskeletal dynamics [4–7]. While it was initially found to play a role in cytokinesis, KIF14 is now recognized as an oncogenic driver in multiple malignancies, and its aberrant expression correlates with aggressive tumor progression, enhanced metastatic potential, and therapeutic resistance [8–10]. Previous studies have revealed diverse mechanisms through which KIF14 promotes cancer progression. In breast cancer, KIF14 promotes cell migration and invasion by modulating the Rap1–Radil signaling pathway [11]. In gastric cancer, it influences AKT-mediated epithelial-mesenchymal transition (EMT), and in esophageal squamous cell carcinoma, it maintains metastatic capability by interacting with mitochondrial proteins [12,13]. Previous studies have shown that KIF14 promotes CRC cell proliferation by activating the Akt signaling pathway and acts as a direct target of miR-200c [14,15]. However, its role in CRC metastasis remains unclear.

Focal adhesions play crucial roles in tumor migration and invasion by regulating cell-extracellular matrix (ECM) adhesion and transmitting mechanical signals that promote tumor cell motility and infiltration [16]. Various proteins within focal adhesions, including integrins, focal adhesion kinase (FAK), and Src, activate multiple downstream signaling pathways that orchestrate cell migration, matrix remodeling, and angiogenesis, thereby increasing tumor cell invasiveness [17–19]. Moreover, focal adhesions participate in remodeling the tumor microenvironment by promoting ECM degradation and reorganization, creating favorable conditions for tumor cell dissemination. The dynamic assembly and disassembly of focal adhesions further enable tumor cells to effectively traverse tissue barriers during metastasis, facilitating their directional movement and invasion. Intriguingly, previous studies have demonstrated that KIF14 colocalizes with supervillin (SVIL), a membrane-microfilament binding protein that regulates pseudopodia formation and cellular motility through its interactions with myosin II and cortactin [20]. This spatial association suggests a potential mechanistic link whereby KIF14 modulates focal adhesion dynamics to influence cell migration.