ZKSCAN5 activates LAPTM5 expression by recruiting SETD7 to promote metastasis in pancreatic ductal adenocarcinoma.

Lysosomal-associated transmembrane protein 5 (LAPTM5) has been associated with poor prognosis in cancer patients. Its role in regulating metastasis in pancreatic ductal adenocarcinoma (PDAC), however, remains vague. The study here aimed to expound the metastasis-promoting properties of LAPTM5 in PDAC and the detailed mechanism. LAPTM5 was overexpressed in metastatic PDAC cells and was related to the dismal prognosis of patients in GEO datasets. By using lentiviral vectors harboring short hairpin RNA, we found that LAPTM5 downregulation reduced PDAC cell viability, proliferation, and aggressiveness in vitro and liver metastasis in vivo. Zinc finger with KRAB and SCAN domains 5 (ZKSCAN5) was predicted and verified to mediate LAPTM5 transcription in PDAC cells. Both ZKSCAN5 and SET domains, containing lysine methyltransferase 7 (SETD7) bound to the LAPTM5 promoter, and ZKSCAN5 recruited SETD7 to form a complex promoting LAPTM5 transcription. LAPTM5 knockdown reversed the promoting effect of ZKSCAN5 on the metastasis of PDAC cells. Thus, our findings on the ZKSCAN5/SETD7/LAPTM5 axis provide insights into the underlying mechanism of liver metastasis dissemination in PDAC.