Localization of RNAs at protrusive regions of cells is important for single-cell migration on two-dimensional surfaces. Protrusion-enriched RNAs encode factors linked to cancer progression, such as the RAB13 GTPase and the NET1 guanine nucleotide exchange factor, and are regulated by the tumor-suppressor protein APC. However, tumor cells in vivo often do not move as single cells but rather utilize collective modes of invasion and dissemination. Here, we developed an inducible system of three-dimensional (3D) collective invasion to study the behavior and importance of protrusion-enriched RNAs. We find that, strikingly, both the RAB13 and NET1 RNAs are enriched specifically at the invasive front of leader cells in invasive cell strands. This localization requires microtubules and coincides with sites of high laminin concentration. Indeed, laminin association and integrin engagement are required for RNA accumulation at the invasive front. Importantly, perturbing RNA accumulation reduces collective 3D invasion. Examination of in vivo tumors reveals a similar localization of the RAB13 and NET1 RNAs at potential invasive sites, suggesting that this mechanism could provide a targeting opportunity for interfering with collective cancer cell invasion.

RNA在细胞突出区域的定位对于二维表面上的单细胞迁移很重要。富含突起的RNA编码与癌症进展相关的因子，例如RAB13 GTPase和NET1鸟嘌呤核苷酸交换因子，并受肿瘤抑制蛋白APC调节。然而，体内的肿瘤细胞通常不像单个细胞那样运动，而是利用集体的入侵和传播方式。在这里，我们开发了可诱导的三维（3D）集体入侵系统，以研究富含突起的RNA的行为和重要性。令人惊讶的是，我们发现RAB13和NET1RNAs在侵入性细胞链中的前导细胞的侵入性前沿特别富集。这种定位需要微管，并与高层粘连蛋白浓度的位置相吻合。确实，层粘连蛋白结合和整联蛋白的结合对于在侵袭前沿的RNA积累是必需的。重要的是，干扰RNA积累会减少3D集体入侵。体内肿瘤的检查揭示了RAB13和NET1 RNA在潜在侵入部位的相似定位，这表明该机制可为干扰集体癌细胞侵袭提供靶向机会。