Research Progress of Regulatory role of Group Ⅱ p21-activated kinases in cancer and the development of the inhibitors

p21-activated kinases(PAKs) are important downstream effector molecules of the small G protein Rho family Rac and Cdc42 which involved in regulating various biological functions such as cytoskeletal remodeling and cell movement. The human PAKs family can be divided into two types:type I PAKs(PAK1-3) and type Ⅱ PAKs(PAK4-6), in which type Ⅱ PAKs are highly expressed in various tumors and are closely related to the occurrence and prognosis of tumors. Type Ⅱ PAKs play the vital role in the regulation of tumor proliferation, apoptosis, invasion and metastasis, and become a promising anti-tumor target. Herein, the research progress of type Ⅱ PAKs in oncology and the roles of their inhibitors in cancer were reviewed, expecting to develop selective type Ⅱ PAKs inhibitors.