Invasion Of Human Bladder Cancer Cells Research Articles

Cancer-associated fibroblasts promote cell proliferation and invasion via paracrine Wnt/IL1β signaling pathway in human bladder cancer.

Bladder cancer (BC) is the most common urinary system malignancy worldwide. However, the molecular mechanisms underlying its progression remain largely unexplored. Accumulating evidence indicates that the cancer-associated fibroblasts (CAFs), major constituents of tumor stroma, play a key role in tumor development. Herein, we have successfully isolated CAFs and paired normal fibroblasts (NFs) from bladder cancer tissues. We observed that the conditional medium from bladder cancer (CM-CAF) could significantly enhance cell proliferation (p<0.01) and invasion capacity (p<0.01) of bladder cancer cell lines T24 and J82, compared to the conditional medium from NFs or 5637 cells (bladder epithelial cell control). We subsequently identified cytokine IL1β is enriched in CM-CAF, and a further functional study showed CAF-derived IL1β contributes to the aggressiveness of T24 cells. In mechanisms, we demonstrated that a high level of IL1β is capable of activating Wnt signaling in T24 cells, and Wnt signaling upregulates the expression of IL1β, therefore forming a paracrine Wnt/IL1β signaling feedback to enhance the aggressive phenotype of bladder cancer cells. In addition, we treated T24 cells with CM-CAF alone, or together with Wnt signaling inhibitor XAV939. We found that the inhibition of Wnt signaling could sufficiently abolish the oncogenic effect of CAFs on bladder cancer. In conclusion, our data revealed a novel mechanism that CAFs promote cell proliferation and invasion of human BC cells through Wnt/IL1β signaling feedback. Inhibition of the Wnt signaling pathway may provide a promising target to block the interaction between CAF and bladder cancer cells.

The inhibitory effect of compound ChlA-F on human bladder cancer cell invasion can be attributed to its blockage of SOX2 protein.

Sex-determining region Y-box 2 (SOX2), a well-known stemness biomarker, is highly expressed in a variety of cancers, including human highly invasive bladder cancer (BC). However, the role of SOX2 may vary in different kinds of malignancy. In the present study, we discovered that ChlA-F, a novel conformation derivative of isolate Cheliensisin A (Chel A), remarkably inhibits the invasive ability of human invasive BC cells through downregulation of SOX2 protein expression. We found that ChlA-F treatment dramatically decreases SOX2 protein expression in human high-grade invasive BC cells. Ectopic expression of SOX2 reversed ChlA-F inhibition of cell invasion ability in human bladder cancer cells, suggesting that SOX2 is a major target of ChlA-F during its inhibition of human BC invasion. Mechanistic studies revealed that ChlA-F downregulates SOX2 at both the protein degradation and protein translation levels. Further studies revealed that ChlA-F treatment induces HuR protein expression and that the increased HuR interacts with USP8 mRNA, resulting in elevation of USP8 mRNA stability and protein expression. Elevated USP8 subsequently acts as an E3 ligase to promote SOX2 ubiquitination and protein degradation. We also found that ChlA-F treatment substantially increases c-Jun phosphorylation at Ser63 and Ser73, initiating miR-200c transcription. The increased miR-200c directly binds to the 3'-UTR of SOX2 mRNA to suppress SOX2 protein translation. These results present novel mechanistic insight into understanding SOX2 inhibition upon ChlA-F treatment and provide important information for further exploration of ChlA-F as a new therapeutic compound for the treatment of highly invasive/metastatic human BC patients.

Transcriptionally elevation of miR-494 by new ChlA-F compound via a HuR/JunB axis inhibits human bladder cancer cell invasion

Muscle invasive bladder cancer (MIBC) is characterized by a poor overall survival rate in patients. Therefore, innovation and evaluation of idea anti-cancer compounds is of importance for reducing the mortality of MIBCs. The chemotherapeutic activity of ChlA-F, a novel C8 fluoride derivative of cheliensisin A with potent anti-neoplastic properties, was barely investigated. We reported here that ChlA-F treatment significantly induced miR-494 expression and suppressed cell invasion in human MIBC cells. Our results indicated that miR-494 was downregulated in M1 metastatic BC patients in comparison to non-metastatic (M0) BC patients, and such downregulation was also well correlated with over survival rate for MIBC patients. Mechanistically, ChlA-F-induced upregulation of miR-494 was due to a HuR-mediated increase in JunB mRNA stabilization and protein expression, which led to an increase in miR-494 transcription via directly binding to the miR-494 promoter region, while the upregulated miR-494 was able to bind the 3′-UTR region of c-Myc mRNA, resulting in decreased c-Myc mRNA stability and protein expression and further reducing the transcription of c-Myc-regulated MMP-2 and ultimately inhibiting BC invasion. Our results provide the first evidence showing that miR-494 downregulation was closely associated with BC metastatic status and overall BC survival, and ChlA-F was able to reverse the level of miR-494 with a profound inhibition of human BC invasion in human invasive BC cells. Our studies also reveal that ChlA-F is a promising therapeutic compound for BCs and miR-494 could also serve as a promising therapeutic target for the treatment of MIBC patients.

ISO, via Upregulating MiR-137 Transcription, Inhibits GSK3β-HSP70-MMP-2 Axis, Resulting in Attenuating Urothelial Cancer Invasion

Our most recent studies demonstrate that miR-137 is downregulated in human bladder cancer (BC) tissues, while treatment of human BC cells with isorhapontigenin (ISO) elevates miR-137 abundance. Since ISO showed a strong inhibition of invasive BC formation in the N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN)-induced invasive BC mouse model, the elucidation of a potential biological effect of miR-137 on antagonizing BC invasion and molecular mechanisms underlying ISO upregulation of miR-137 are very important. Here we discovered that ectopic expression of miR-137 led to specific inhibition of BC invasion in human high-grade BC T24T and UMUC3 cells, while miR-137 deletion promoted the invasion of both cells, indicating the inhibitory effect of miR-137 on human BC invasion. Mechanistic studies revealed that ISO treatment induced miR-137 transcription by promoting c-Jun phosphorylation and, in turn, abolishing matrix metalloproteinase-2 (MMP-2) abundance and invasion in BC cells. Moreover, miR-137 was able to directly bind to the 3′ UTR of Glycogen synthase kinase-3β (GSK3β) mRNA and inhibit GSK3β protein translation, consequently leading to a reduction of heat shock protein-70 (HSP70) translation via targeting the mTOR/S6 axis. Collectively, our studies discover an unknown function of miR-137, directly targeting the 3′ UTR of GSK3β mRNA and, thereby, inhibiting GSK3β protein translation, mTOR/S6 activation, and HSP70 protein translation and, consequently, attenuating HSP70-mediated MMP-2 expression and invasion in human BC cells. These novel discoveries provide a deep insight into understanding the biomedical significance of miR-137 downregulation in invasive human BCs and the anti-cancer effect of ISO treatment on mouse invasive BC formation.

Abstract 107: Interaction of BIR domain of XIAP with Sp1/E2F1 activates MMP2 and bladder cancer cell invasion by inhibiting src protein translation

Abstract X-linked inhibitor of apoptosis protein (XIAP) is important in the regulation of cancer cell biological behaviors. However, little is known about the molecular mechanism by which the XIAP domains promote aggressive tumor behavior in human bladder cancer (BC). Herein, we discovered that ectopic expression of the BIR domains of XIAP rescued the MMP2 activation and human BC invasion in human BC cells with XIAP deletion. Interestingly, Src expression was upregulated in XIAP/BIR domain-deficient cells, whereas restoration of BIR domain in XIAP-deletion cells recused Src expression. Moreover, knockdown of Src reversed the defects of MMP2 activation and BC invasion in XIAP-deficient BC cells, revealing that Src acts as a XIAP downstream negative regulator for MMP2 activation and BC invasion. Mechanistic studies revealed that the regulatory effect of the BIR domains of XIAP on Src expression was due to directly inhibition of its protein translation by upregulation of miR-203 resulting from activation of the transcription factors Sp1 and E2F1, while the BIR domains of XIAP was found to interact with both Sp1 and E2F1 to activate these transcription factors. Overall, our studies demonstrate that BIR domain of XIAP is able to bind to Sp1 and E2F1 leading to their transcriptional activation, resulting their targeted miR-203 transcription, consequently directly targets the 3'-UTR of src mRNA and therefore attenuating SRC protein translation, and activating MMP2 and BC invasion. Citation Format: Xiaohui Hua, Jiheng Xu, Honglei Jin, Chuanshu Huang. Interaction of BIR domain of XIAP with Sp1/E2F1 activates MMP2 and bladder cancer cell invasion by inhibiting src protein translation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 107.

Sulforaphane inhibits human bladder cancer cell invasion by reversing epithelial-to-mesenchymal transition via directly targeting microRNA-200c/ZEB1 axis

Sulforaphane (SFN), one of the isothiocyanates, abundantly existed in quite a few of cruciferous vegetables and exhibits effective anticancer activities in our previous experiments. However, its effects on bladder cancer cell invasion and metastasis have only begun to be explored. Here, we investigated the effect of microRNA on bladder cancer cell invasion and the underlying molecular mechanism. According to the gene chip results, SFN obviously increased microRNA-200c (miR-200c) expression, one of the short noncoding RNAs that acts as considerable modulator in epithelial mesenchymal transition (EMT). Moreover, SFN dose-dependently induced EMT hallmark E-cadherin and down-regulated vimentin and transcriptional repressor ZEB1 at the level of transcription and translation, and these effects can be reversed by miR-200c inhibitor transfection. Remarkably, Transwell assay showed that cell invasiveness ability can be eradicated by silencing of ZEB1. Therefore, these findings firmly suggest that SFN inhibited bladder cancer cell invasion through reversing EMT via targeting miR-200c/ZEB1 axis.

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

Our most recent studies demonstrate that RhoGDIβ is able to promote human bladder cancer (BC) invasion and metastasis in an X‐link inhibitor of apoptosis protein‐dependent fashion accompanied by increased levels of matrix metalloproteinase (MMP)‐2 protein expression. We also found that RhoGDIβ and MMP‐2 protein expressions are consistently upregulated in both invasive BC tissues and cell lines. In the present study, we show that knockdown of RhoGDIβ inhibited MMP‐2 protein expression accompanied by a reduction of invasion in human BC cells, whereas ectopic expression of RhoGDIβ upregulated MMP‐2 protein expression and promoted invasion as well. The mechanistic studies indicated that MMP‐2 was upregulated by RhoGDIβ at the transcriptional level by increased specific binding of the transcription factor Sp1 to the mmp‐2 promoter region. Further investigation revealed that RhoGDIβ overexpression led to downregulation of miR‐200c, whereas miR‐200c was able directly to target 3′‐UTR of jnk2 mRNA and attenuated JNK2 protein translation, which resulted in attenuation of Sp1 mRNA and protein expression in turn, inhibiting Sp1‐dependent mmp‐2 transcription. Collectively, our studies demonstrate that RhoGDIβ overexpression inhibits miR‐200c abundance, which consequently results in increases of JNK2 protein translation, Sp1 expression, mmp‐2 transcription, and BC invasion. These findings, together with our previous results showing X‐link inhibitor of apoptosis protein mediating mRNA stabilization of both RhoGDIβ and mmp‐2, reveal the nature of the MMP‐2 regulatory network, which leads to MMP‐2 overexpression and BC invasion.

Tanshinone IIA Inhibits Epithelial-Mesenchymal Transition in Bladder Cancer Cells via Modulation of STAT3-CCL2 Signaling.

Tanshinone IIA (Tan-IIA) is an extract from the widely used traditional Chinese medicine (TCM) Danshen (Salvia miltiorrhiza), and has been found to attenuate the proliferation of bladder cancer (BCa) cells (The IC50 were: 5637, 2.6 μg/mL; BFTC, 2 μg/mL; T24, 2.7 μg/mL, respectively.). However, the mechanism of the effect of Tan-IIA on migration inhibition of BCa cells remains unclear. This study investigates the anti-metastatic effect of Tan-IIA in human BCa cells and clarifies its molecular mechanism. Three human BCa cell lines, 5637, BFTC and T24, were used for subsequent experiments. Cell migration and invasion were evaluated by transwell assays. Real-time RT-PCR and western blotting were performed to detect epithelial-mesenchymal transition (EMT)-related gene expression. The enzymatic activity of matrix metalloproteinases (MMP) was evaluated by zymography assay. Tan-IIA inhibited the migration and invasion of human BCa cells. Tan-IIA suppressed both the protein expression and enzymatic activity of MMP-9/-2 in human BCa cells. Tan-IIA up-regulated the epithelial marker E-cadherin and down-regulated mesenchymal markers such as N-cadherin and Vimentin, along with transcription regulators such as Snail and Slug in BCa cells in a time- and dose-dependent manner. Mechanism dissection revealed that Tan-IIA-inhibited BCa cell invasion could function via suppressed chemokine (C-C motif) ligand 2 (CCL2) expression, which could be reversed by the addition of CCL2 recombinant protein. Furthermore, Tan-IIA could inhibit the phosphorylation of the signal transducer and activator of transcription 3 (STAT3) (Tyr705), which cannot be restored by the CCL2 recombinant protein addition. These data implicated that Tan-IIA might suppress EMT on BCa cells through STAT3-CCL2 signaling inhibition. Tan-IIA inhibits EMT of BCa cells via modulation of STAT3-CCL2 signaling. Our findings suggest that Tan-IIA can serve as a potential anti-metastatic agent in BCa therapy.

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

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 growth, nothing is known whether ISO possesses an inhibitory effect on bladder cancer invasion. Thus, we addressed this important question in current study and discovered that ISO treatment could inhibit mouse-invasive bladder cancer development following bladder carcinogen N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) exposure in vivo We also found that ISO suppressed human bladder cancer cell invasion accompanied by upregulation of the forkhead box class O 1 (FOXO1) mRNA transcription in vitro Accordingly, FOXO1 was profoundly downregulated in human bladder cancer tissues and was negatively correlated with bladder cancer invasion. Forced expression of FOXO1 specifically suppressed high-grade human bladder cancer cell invasion, whereas knockdown of FOXO1 promoted noninvasive bladder cancer cells becoming invasive bladder cancer cells. Moreover, knockout of FOXO1 significantly increased bladder cancer cell invasion and abolished the ISO inhibition of invasion in human bladder cancer cells. Further studies showed that the inhibition of Signal transducer and activator of transcription 1 (STAT1) phosphorylation at Tyr701 was crucial for ISO upregulation 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 bladder cancer formation. These findings not only provide a novel insight into the understanding of mechanism of bladder cancer's propensity to invasion, but also identify a new role and mechanisms underlying the natural compound ISO that specifically suppresses such bladder cancer invasion through targeting the STAT1-FOXO1-MMP-2 axis. Cancer Prev Res; 9(7); 567-80. ©2016 AACR.

Abstract 5104: Isorhapontigenin (ISO) inhibits cancer invasion by enhancing FOXO1 transcription through targeting STAT1 phosphorylation at Tyr701

Abstract Muscle invasion of bladder cancer can progress to life threatening metastases. Isorhapontigenin (ISO) is a novel derivative of stilbene that isolated from a Chinese herb Gnetum cleistostachyum, which has been used for centuries as treatment for several cancers including bladder cancer. However, nothing is known whether ISO possesses an inhibitory effect on invasion in human cancers. Here, we found that 10 to 20 mmol/L of ISO, which were relevant to in vivo study, inhibited human bladder cancer cell invasion accompanied by up-regulation of the forkhead box class O1 (FOXO1) mRNA transcription. Accordingly, FOXO1 was significantly down-regulated in invasive human bladder cancer tissues, and forced expression of FOXO1 specifically suppressed invasion of human bladder cancer cells. Moreover, knockdown of FOXO1 expression abolished the ISO inhibition of invasion. Further studies showed that increased FOXO1 transcription was accompanied by reduction of STAT1 phosphorylation at Tyr701, and repressing STAT1 phosophorylation by the overexpression of dominant negative STAT1 could mimic the effect of ISO treatment on FOXO1 transcription, while the mutation of STAT1's binding site in the FOXO1 promoter profoundly impaired ISO-induced up-regulation of FOXO1 transcription. Furthermore, this study revealed that metalloproteinase-2 (MMP-2) was a FOXO1 downstream effector mediating its effect on bladder cancer invasion. These findings not only provide a novel insight into the understanding of underlying mechanism of bladder cancer's propensity to invasion, but also identify a new role and mechanisms underlying the natural compound ISO that specifically suppresses such invasion through targeting the STAT1-FOXO1-MMP2 axis. Citation Format: Lei Xue, Guosong Jiang, Jingxia Li, Chuanshu Huang. Isorhapontigenin (ISO) inhibits cancer invasion by enhancing FOXO1 transcription through targeting STAT1 phosphorylation at Tyr701. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5104. doi:10.1158/1538-7445.AM2015-5104

Specific sequences of fibronectin activate the protein kinase C signal transduction pathway in invasive bladder cancer.

The mechanism of human bladder cancer cell invasion is not clear, but it appears that extracellular matrix components, such as fibronectin, may be involved. To investigate the role of fibronectin in tumor cell invasion and progression, we used an in vitro invasion assay to define the motility stimulating fragment of fibronectin for invasive human bladder cancer T24 cells. Using a modified Boyden chamber assay and purified fragments of fibronectin, we demonstrated that both the 120 kDa chymotrypsin generated fragment of fibronectin (containing the cell attachment RGD motif and additional sequences towards the carboxyl-terminal heparin binding domain), as well as the trypsin generated 60 kDa fragment of fibronectin (containing the carboxyl-terminal heparin binding domain and additional sequences towards the cell attachment RGD motif), were able to stimulate the migration of invasive human bladder cancer T24 cells. Control fragments containing only the amino-terminal gelatin binding region of fibronectin did not stimulate the motility of the human bladder cancer T24 cells. To determine the molecular mechanism in which these fragments may stimulate the migration of the T24 cells, we assayed for intracellular signal transduction pathway protein kinase C (PKC). We demonstrated that both the 120 kDa and the 60 kDa fragments were able to stimulate the activation of protein kinase C. Non-motility stimulating fragments of fibronectin were not able to activate protein kinase C. We conclude that the PKC signal transduction pathway may be involved in matrix mediated motility, and suggest that the inhibition of such pathway(s) may alter the malignant phenotype of human bladder cancer.