Isorhapontigenin (ISO) Inhibits Invasive Bladder Cancer Formation In Vivo and Human Bladder Cancer Invasion In Vitro by Targeting STAT1/FOXO1 Axis

Abstract

Although our most recent studies have identified Isorhapontigenin (ISO), a novel derivative of stilbene that isolated from a Chinese herb Gnetum cleistostachyum, for its inhibition of human bladder cancer (BC) growth, nothing is known whether ISO possesses an inhibitory effect on BC invasion. Thus, we addressed this important question in current study and discovered that ISO treatment could inhibit mouse invasive BC development following bladder carcinogen N-butyl-N- (4-hydroxybutyl) nitrosamine (BBN) exposure in vivo. We also found that ISO suppressed human BC cell invasion accompanied by up-regulation of the forkhead box class O 1 (FOXO1) mRNA transcription in vitro. Accordingly, FOXO1 was profoundly down-regulated in human BC tissues, and was negatively correlated with BC invasion. Forced expression of FOXO1 specifically suppressed high grade human BC cell invasion, while knockdown of FOXO1 promoted non-invasive BC cells becoming invasive BC cells. Moreover, knockout of FOXO1 significantly increased BC cell invasion and abolished the ISO inhibition of invasion in human BC cells. Further studies showed that the inhibition of STAT1 phosphorylation at Tyr701 was crucial for ISO up-regulation of FOXO1 transcription. Furthermore, this study revealed that metalloproteinase-2 (MMP-2) was a FOXO1 downstream effector, which was also supported by data obtained from mouse model of ISO inhibition BBN-induced mouse invasive BC formation. These findings not only provide a novel insight into the understanding of mechanism of BC’s propensity to invasion, but also identify a new role and mechanisms underlying the natural compound ISO that specifically suppresses such BC invasion through targeting the STAT1-FOXO1-MMP2 axis.

RhoGDIβ promotes Sp1/MMP‐2 expression and bladder cancer invasion through perturbing miR‐200c‐targeted JNK2 protein translation

“…T24 is a non‐metastatic cell line, whereas T24T is a BC cell line with lung metastatic ability (Gildea et al ., ; Grossman et al ., ). Both cell lines were cultured in DMEM:F‐12 1 : 1 with 10% fetal bovine serum (FBS; ATLANTA, Flowery Branch, GA, USA) as described in our previous studies (Jiang et al ., ; Jin et al ., ), and cell lines will be authenticated every 6–12 months by Genetica DNA Laboratories (Burlington, NC 27215, CA, USA) and the results compared with the data in the ATCC STR database. The human mmp‐2 promoter‐driven luciferase reporter was a gift from Dr. Yi Sun (Michigan University, MI, USA) (Qin et al ., ).…”

“…Alterations of MMP‐2 are often associated with the metastasis of many other cancers, including colorectal cancer (Miao et al ., ), ovarian cancer (Zhuang et al ., ), and breast cancer (Miao et al ., ). Our recent study reveals that MMP‐2 overexpression is crucial for human BC invasion (Jin et al ., ), whereas inhibition of MMP‐2 expression by the anti‐cancer agent isorhapontigenin (ISO) dramatically attenuated both BC invasion in vitro and highly invasive BC formation in vivo (Jiang et al ., ) .…”

Role of STAT3 and FOXO1 in the Divergent Therapeutic Responses of Non-metastatic and Metastatic Bladder Cancer Cells to miR-145

“…The foxo1 promoter contains STATs binding sites, and it has been shown that STAT3 can bind to these sites in immune system T cells (48). We recently showed that phosphorylated STAT1 can bind to the foxo1 promoter to inhibit its transcription in BC cells (49). In the present study, we found that miR-145 suppressed STAT3 activation and increased foxo1 promoter transcriptional activity, which overcame its inhibition on foxo1 mRNA 3′UTR activation, and subsequently upregulated FOXO1 expression and suppressed anchorage-independent growth of non-metastatic T24 cells.…”

Interaction of BIR2/3 of XIAP with E2F1/Sp1 Activates MMP2 and Bladder Cancer Invasion by Inhibiting Src Translation

“…The human invasive BC cell line UMUC3 was provided by Dr. Xue-Ru Wu (Department of Urology and Pathology, New York University School of Medicine, New York, NY), and was used in our previous studies [52]. The human metastatic BC cell line T24T, which is a lineage-related metastatic lung variant of the invasive BC cell line T24 [53], was kindly provided by Dr. Dan Theodorescu [54] and used in our previous studies [55].…”

“…In vitro migration and invasion assays were conducted using transwell chambers (for migration assays) or transwell chambers pre-coated with Matrigel (for invasion assays) according to the manufacturer's protocol (BD Biosciences, Bedford, MA), as described previously [52]. Briefly, 700 μl of medium containing 10% FBS (for UMUC3 and T24T cells with different transfectants) was added to the lower chambers, while homogeneous single cell suspensions (5×10 4 cells/well) in 0.1% FBS medium as indicated were added to the upper chambers.…”