To study the mechanism of gigantol inhibiting the proliferation of pancreatic carcinoma (PC) cells by targeting urokinase-type plasminogen activator (PLAU).

PC cells (PANC-1 and SW1990) were treated with different concentrations of gigantol. The cells activity was detected by CCK-8, and half-maximal inhibitory concentration (IC₅₀) was calculated. Cell clone assay was performed to detect the effects of gigantol on cells growth ability. The effects of gigantol on cells growth cycle and apoptosis were detected by flow cytometer. The targets of gigantol were analyzed by bioinformatics, expressions of these targets in PC tissues and their relationship with poor clinical phenotypes were analyzed.PC cells were transfected with PLAU or vector plasmid, and divided into normal group (vector plasmid), gigantol group (45 μmol·L^-1 or 50 μmol·L^-1) and gigantol + PLAU (PLAU plasmid) group. The effects of gigantol on cells proliferation, clone, cells cycle and apoptosis by targeting PLAU were observed. The expression of PLAU protein in cells was detected by Western blot. The inhibitory effects of gigantol on cells proliferation in vivo were detected by xenograft assay in nude mice.The expression of proliferating cell antigen (Ki67) was detected by immunohistochemistry.

Compared with the normal group, gigantol group showed a significant decrease in cell proliferation and clone number (P<0.05), and an increase in the number of G₀/G₁-phase cells, a decrease in the number of S-phase cells (P<0.05), and an increase in the number of apoptotic cells (P<0.05). There were no significant difference in the number of G2/M-phase cells between the two groups (P<0.05). Bioinformatics results showed that PLAU was the target of gigantol, which was up-regulated in PC tissues and related to poor clinical phenotypes of PC. Gigantol could inhibit the expression of PLAU protein in PC cells, showing concentration and time dependence (P<0.05). PLAU protein expression, proliferation activity and clone number, and the number of S-phase cells in PC cells were higher in the gigantol +PLAU group than in the gigantol group, while the number of apoptotic cells was less than in the gigantol group (P<0.05). In the nude mice experiments, the volume and weight of transplanted tumors in the gigantol group were significantly lower than those in the normal group (P<0.05), and the relative expression of Ki67 in tumor tissues was lower than that in the normal group (P<0.05).

Gigantol can inhibit the proliferation of PC cells, affect cells cycle and promote apoptosis by targeting the expression of PLAU protein.