Wei Zhili, Wang Ru, Yin Xun, Zhang Lian, Lei Yunlong, Zhang Ying, Li Yi, Wu Jiaqian, Bu Youquan, Jin Guoxiang, Zhang Chundong
Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, PR China.
Molecular Medicine and Cancer Research Center, Chongqing Medical University, Chongqing 400016, PR China.
Genes Dis. 2021 Mar 2;9(1):230-244. doi: 10.1016/j.gendis.2021.02.012. eCollection 2022 Jan.
Filopodia, a finger-like structure and actin-rich plasma-membrane protrusion at the leading edge of the cell, has important roles in cell motility. However, the mechanisms of filopodia generation are not well-understood via the actin-related protein 2/3 (ARP2/3) complex in Non-Small Cell Lung Cancer (NSCLC) cells. We previously have demonstrated that PRR11 associates with the ARP2/3 complex to regulate cytoskeleton-nucleoskeleton assembly and chromatin remodeling. In this study, we further demonstrate that PRR11 involves in filopodia formation, focal adhesion turnover and cell motility through ARP2/3 complex. Cell phenotype assays revealed that the silencing of PRR11 increased cellular size and inhibited cell motility in NSCLC cells. Mechanistically, PRR11 recruited and co-localized with Arp2 at the membrane protrusion to promote filopodia formation but not lamellipodia formation. Notably, PRR11 mutant deletion of the proline-rich region 2 (amino acid residues 185-200) abrogated the effect of filopodia formation. In addition, PRR11-depletion inhibited filopodial actin filaments assembly and increased the level of active integrin β1 in the cell surface, whereas reduced the phosphorylation level of focal adhesion kinase (FAK) to repress focal adhesion turnover and cell motility in NSCLC cells. Taken together, our findings indicate that PRR11 has critical roles in controlling filopodia formation, focal adhesion turnover and cell motility by recruiting ARP2/3 complex, thus dysregualted expression of PRR11 potentially facilitates tumor metastasis in NSCLC cells.
丝状伪足是一种指状结构，是细胞前缘富含肌动蛋白的质膜突起，在细胞运动中发挥重要作用。然而，在非小细胞肺癌（NSCLC）细胞中，通过肌动蛋白相关蛋白2/3（ARP2/3）复合物产生丝状伪足的机制尚未完全明确。我们之前已经证明PRR11与ARP2/3复合物相关联，以调节细胞骨架-核骨架组装和染色质重塑。在本研究中，我们进一步证明PRR11通过ARP2/3复合物参与丝状伪足的形成、粘着斑周转和细胞运动。细胞表型分析显示，PRR11的沉默增加了NSCLC细胞的大小并抑制了细胞运动。机制上，PRR11在膜突起处与Arp2募集并共定位，以促进丝状伪足的形成，但不促进片状伪足的形成。值得注意的是，PRR11富含脯氨酸区域2（氨基酸残基185-200）的突变缺失消除了丝状伪足形成的作用。此外，PRR11的缺失抑制了丝状伪足肌动蛋白丝的组装，并增加了细胞表面活性整合素β1的水平，而降低了粘着斑激酶（FAK）的磷酸化水平，以抑制NSCLC细胞中的粘着斑周转和细胞运动。综上所述，我们的研究结果表明，PRR11通过募集ARP2/3复合物在控制丝状伪足形成、粘着斑周转和细胞运动中起关键作用，因此PRR11的表达失调可能促进NSCLC细胞中的肿瘤转移。
