The epithelial-to-mesenchymal transition (EMT) plays a prominent role in cancer metastasis. Isoliquiritigenin (ISL), one of the flavonoids in licorice, has been shown to exhibit anticancer activities in many cancer types through various mechanisms. However, it is unknown whether ISL impacts the EMT process. Here, we show that ISL is able to suppress mesenchymal features of ovarian cancer SKOV3 and OVCAR5 cells, evidenced by an apparent morphological change from a mesenchymal to an epithelial phenotype and reduced levels of mesenchymal markers accompanied by the gain of E-cadherin expression. The suppression of EMT is also supported by the observed decrease in cell migration and in vitro invasion upon ISL treatment. Moreover, we show that ISL effectively blocks the intraperitoneal xenograft development of the SKOV3 cell line and prolonged the survival of tumor-bearing mice. These data suggest that ISL inhibits intraperitoneal ovary tumor development through the suppression of EMT, indicating that ISL may be an effective therapeutic agent against ovarian cancer.

Licorice is an herb extensively used for both culinary and medicinal purposes. Various constituents of licorice have been shown to exhibit anti-tumorigenic effect in diverse cancer types. However, majority of these studies focus on the aspect of their growth-suppressive role. In this study, we systematically analyzed known licorice’s constituents on the goal of identifying component(s) that can effectively suppress both cell migration and growth. Effect of licorice’s constituents on cell growth was evaluated by MTT assay while cell migration was assessed by both wound-healing and Transwell assays. Cytoskeleton reorganization and focal adhesion assembly were visualized by immunofluorescence staining with labeled phalloidin and anti-paxillin antibody. Activity of Src in cells was judged by western blot using phosphor-Src416 antibody while Src kinase activity was measured using Promega Src kinase assay system. Anti-tumorigenic capabilities of isoliquiritigenin (ISL) and 2, 4, 2′, 4’-Tetrahydroxychalcone (THC) were investigated using lung cancer xenograft model. Using a panel of lung cancer cell lines, ISL was identified as the only licorice’s constituent capable of inhibiting both cell migration and growth. ISL-led inhibition in cell migration resulted from impaired cytoskeleton reorganization and focal adhesion assembly. Assessing the phosphorylation of 141 cytoskeleton dynamics-associated proteins revealed that ISL reduced the abundance of Tyr421-phosphorylation of cortactin, Tyr925- and Tyr861-phosphorylation of FAK, indicating the involvement of Src because these sites are known to be phosphorylated by Src. Enigmatically, ISL inhibited Src in cells while displayed no effect on Src activity in cell-free system. The discrepancy was explained by the observation that THC, one of the major ISL metabolite identified in lung cancer cells abrogated Src activity both in cells and cell-free system. Similar to ISL, THC deterred cell migration and abolished cytoskeleton reorganization/focal adhesion assembly. Furthermore, we showed both ISL and THC suppressed in vitro lung cancer cell invasion and in vivo tumor progression. Our study suggests that ISL inhibits lung cancer cell migration and tumorigenesis by interfering with Src through its metabolite THC. As licorice is safely used for culinary purposes, our study suggests that ISL or THC may be safely used as a Src inhibitor.

Background: The role of B Lymphocyte Stimulator (BLyS) in the survival of malignant B cells and the maintenance of normal B cell development and homeostasis has been intensively studied in the literature. However, the influence of BLyS on breast cancer progression remains unclear. The study aimed to investigate the effect of hypoxia on BLyS regulation, cell migratory response to BLyS and the possible molecular mechanisms. Methods: In this study, we examined the role of BLyS in the migration of human breast cancer cells by transwell assay. We also explored whether BLyS and its receptors expressed in human breast cancer cell lines by immunofluorescence and Western Blotting. Then we detected the expression level of BLyS in both normoxic and hypoxic conditions by real time-PCR and Western Blotting. Pathways involved were confirmed by Western Blotting, immunofluorescence, transwell assay and luciferase assay. Results: According to our study, the expression level of BlyS was increased in human breast cancer cell lines in hypoxic conditions. Up-regulation of this protein led to activation and nuclear translocation of NF-kappa B p65. We also found that the number of migrated cells was increased in the presence of BLyS and inhibition of phosphorylation of Akt attenuated the enhanced migratory response. Conclusions: It suggested that better understanding of BLyS, an immunopotentiator, may offer a potential therapeutic target for the treatment of human breast cancers. In addition, BLyS promoted breast cancer cells migration, underscoring the necessity of appropriate applications of immunopotentiators to cancer treatment.

Background/Objectives: Ovarian cancer is a prevalent gynecological malignancy with high mortality rates worldwide. Harmine hydrochloride (HMH), a tricyclic β-carboline alkaloid derived from the seeds of the medicinal plant Peganum harmala L., has demonstrated anti-tumor activity. This study investigated the effect of HMH on ovarian cancer and elucidated its underlying molecular mechanism. Methods: The anti-ovarian cancer effects of HMH were evaluated using the CCK-8 assay, cell cycle and apoptosis analyses, as well as a cell migration assay. The RNA-seq was utilized to explore the mechanisms of HMH. Western blot, qRT-PCR and IF were employed for further validation of the expression levels of relevant molecules. The Kaplan–Meier (KM) curve was conducted to evaluate the possible link between NFAT1 levels and the prognosis of ovarian cancer. The biological functions of NFAT1 were explored through siRNA knockdown experiments. Auto-dock molecular docking and DARTS were used to analyze the direct interaction between HMH and NFAT1. The in vivo efficacy of HMH was examined through bioluminescence imaging of intraperitoneal xenografts established with luciferase-expressing HEY cells. Results: HMH induced apoptosis, arrested the cell cycle, and suppressed migration of HEY and CAOV3 cells. NFAT1 was highly expressed in the nucleus of HEY and CAOV3 cells and promoted ovarian cancer progression. In addition, low NFAT1 expression levels had significantly improved overall survival and progression-free survival. Moreover, HMH reduced NFAT1 expression and reversed Ion-induced NFAT1 levels in ovarian cancer cell nuclei. The molecular docking and DARTS results suggested that HMH binds to NFAT1. Treatment with MG132 effectively blocked HMH-induced NFAT1 downregulation. Furthermore, HMH effectively blocked intraperitoneal xenograft development, and extended the life span of animals bearing HEY/Luc cells, when used alone or in combination with CDDP. Conclusions: The research indicated that HMH exerts anti-ovarian cancer effects, at least in part, by targeting NFAT1. Additionally, our research revealed that NFAT1 promotes ovarian cancer progression, and plays a significant role in HMH’s anti-cancer activity. These results may aid in the development of novel candidates for ovarian cancer and identify a new target for ovarian cancer treatment.