恶性肿瘤的转移是一个多步骤的过程，其中恶性肿瘤细胞的定向运动在肿瘤转移中起着极其关键的作用，然而恶性肿瘤细胞定向运动的分子机制远未阐明。Rac1蛋白在定向运动细胞中呈现前端募集和定位的现象，是启动和维持细胞定向运动的关键。本工作从Rab35对恶性肿瘤细胞内Rac1蛋白靶向定位过程中的作用和作用机制入手，从而致力于：（1）阐明Rab35在Rac1的细胞前端定位和细胞定向运动的调控中是否起着关键作用；（2）确定Rab35mRNA是否通过细胞内微管细胞骨架系统被主动运输到细胞前端，实现Rab35在细胞前端富集，从而进一步调控Rac1蛋白在细胞前端定位，并最终实现恶性肿瘤细胞的定向运动。本研究目标的完成将使人们对恶性肿瘤细胞定向运动的机制有更深入的认识。

Metastasis of malignant tumors is a multi-step process, which depends on the ability of directional migration of the malignant cells. The polarization of Rac1 to the site of plasma membrane protrusion is responsible for cell pseudopodia formation and directional movement. However, the mechanism of Rac1 recruitment to these sites and the identities of accessory molecules involved in this process are not well understood. The priorities of our work are to elucidate: (1) whether rab35 is a regulator of Rac1 trafficking and required specifically for cancer cell directional movement. (2) whether directed active transportation of rab35 mRNA by microtubule tracks is involved in accumulation of rab35 protein at tips of protrusions, which further regulates polarized recruitment of Rac1 and finally causes directional migration of cancer cells. Our research would provide better understanding of the molecular mechanisms involved in directional migration of cancer cells.