microRNA-145 promotes differentiation in human urothelial carcinoma through down-regulation of syndecan-1
© Fujii et al. 2015
Received: 2 June 2015
Accepted: 23 October 2015
Published: 29 October 2015
A new molecular marker of carcinoma in the urinary bladder is needed as a diagnostic tool or as a therapeutic target. Potential markers include microRNAs (miRNAs), which are short, low molecular weight RNAs 19–24 nt long that regulate genes associated with cell proliferation, differentiation, and development in various cancers. In this study, we investigated the molecular mechanisms by which miR-145 promotes survival of urothelial carcinoma cells and differentiation into multiple lineages. We found miR-145 to regulate expression of syndecan-1, a heparin sulfate proteoglycan.
Cell proliferation in the human urothelial carcinoma cell lines T24 and KU7 was assessed by MTS assay. Cellular senescence and apoptosis were measured by senescence-associated β-galactosidase (SA-β-gal) and TUNEL assay, respectively. Quantitative RT-PCR was used to measure mRNA expression of various genes, including syndecan-1, stem cell factors, and markers of differentiation into squamous, glandular, or neuroendocrine cells.
Overexpression of miR-145 induced cell senescence, and thus significantly inhibited cell proliferation in T24 and KU7 cells. Syndecan-1 expression diminished, whereas stem cell markers such as SOX2, NANOG, OCT4, and E2F3 increased. miR-145 also up-regulated markers of differentiation into squamous (p63, TP63, and CK5), glandular (MUC-1, MUC-2, and MUC-5 AC), and neuroendocrine cells (NSE and UCHL-1). Finally, expression of miR-145 was down-regulated in high-grade urothelial carcinomas, but not in low-grade tumors.
Results indicate that miR-145 suppresses syndecan-1 and, by this mechanism, up-regulates stem cell factors and induces cell senescence and differentiation. We propose that miR-145 may confer stem cell-like properties on urothelial carcinoma cells and thus facilitate differentiation into multiple cell types.
KeywordsUrinary bladder cancer MicroRNA MiR-145 Syndecan-1
Urinary bladder cancer is a common malignant tumor with high mortality. Thus, well characterized biomarkers are needed to screen, diagnose and manage bladder cancer. Over the years, a number of studies have examined molecular mechanisms of urothelial carcinoma progression, as well as diagnostic tools and therapeutic strategies [1, 2]. However, useful diagnostic markers that predict clinical outcome have not been found. Potential new biomarkers include microRNAs (miRNAs), which are small non-coding RNAs that regulate gene expression by suppressing protein translation or by promoting degradation of messenger RNA . Therefore, investigation of miRNAs and their targets could provide both novel therapeutic targets as well as diagnostic markers of the development, progression, differentiation, and metastatic potential of malignant tumors. Indeed, some miRNAs are abundantly expressed and act as tumor suppressors. MiRNAs such as miR-1, 100, 101, 133, and 192 are down-regulated in several cancers and promote cell proliferation, migration and invasion [4–7].
Syndecan-1 is expressed in a majority of epithelial and nonepithelial neoplasms, and is involved in cell growth, adhesion, migration, epithelial morphogenesis, and angiogenesis [8–10]. We previously reported that this proteoglycan transforms androgen-dependent prostate cancer cells into androgen-independent tumors and facilitates progression [11, 12]. Moreover, syndecan-1 and the miRNAs miR-126 and, 149 regulate cell proliferation through down-regulation of several stem cell factors such as SOX2, NANOG, and OCT4 . Finally, syndecan-1 was detected in plasmacytoid urothelial carcinoma, an aggressive tumor [14–18], demonstrating that the protein is closely associated with urothelial carcinoma progression .
In this study, we demonstrate that miR-145 in bladder cancer cells down-regulates syndecan-1 expression, inhibits cell proliferation by inducing senescence, and promotes differentiation into glandular, squamous, and neuroendocrine cells. Moreover, miR-145 and syndecan-1 were found to be up-regulated in low-grade urothelial carcinoma, but not in high-grade tumors.
The human urothelial carcinoma cell lines, T24 was purchased from American Type Culture Collection (Manassas, VA), and KU7 was derived from human papillary bladder cancer . T24 and KU7 were cultured in RPMI1640 media supplemented with 10 % fetal bovine serum and 50 units/mL penicillin-streptomycin at 37 °C in 5 % CO2.
T24 or KU7 were seeded at a density of 1x104 cells/well and transfected for 72 h with Anti-miR™ miRNA Inhibitor, Pre-miR™ miRNA Precursor (hsa-miR-145, Life Technologies), or 100 ng/L siRNA against syndecan-1. Transfection was performed in Lipofectamine RNAiMAX (Life Technologies) according to the manufacturer’s protocol. The sequence of the syndecan-1 siRNA was 5′-TCCGACTGCTTTGGACCTAAA-3′.
The sequence list of PCR primers
CellTiter 96 AQueous One Solution Cell Proliferation Assay (Promega) was used for MTS assay as previously described  to measure cell proliferation. Data were collected from triplicate experiments.
Senescence-associated β-galactosidase (SA-β-gal) assay and TdT-mediated dUTP nick end labeling (TUNEL) assay
SA-β-gal was measured using Senescence Detection Kit (BioVision, CA) in T24 cells transfected for 72 h with miR-145 precursor. The assay was performed according to the kit manual. Similarly, T24 cells transfected with miR-145 precursor for 72 h were harvested and stained with ApopTag Plus Peroxidase In Situ Apoptosis Detection Kit (Millipore Corporation, CA).
We examined fifteen trans-urethral resection of bladder tumor specimens without undergoing chemotherapy or Bacillus Calmette-Guerin treatment (age: 51–84 years, grade: low grade 5 cases; high grade 10 cases). The present study received ethics committee approval of Nara Medical University (NMU900). The informed consent was obtained from all patients. All tissue samples were fixed in 10 % formalin for 48 h and processed through graded alcohols to paraffin. Paraffin blocks were sectioned at 3-μm intervals and stained with hematoxylin and eosin (HE) for histological diagnosis. For each HE stained sample, corresponding sections, to include cancer foci of interest, were cut at 8-μm intervals for extraction of total RNA. Tumor stage and grade were noted at the time of diagnosis by two independent urological pathologists (KS and NK) (Fig. 4a). Total RNA, including miRNA, was purified from paraffin-embedded tissue sections using miRNeasy FFPE kit (QIAGEN). First-strand cDNA was synthesized using TaqMan MicroRNA Reverse Transcription Kit (Applied Biosystems), and real-time PCR was performed using TaqMan MicroRNA Assays and TaqMan Universal PCR Master Mix II (Applied Biosystems) to amplify miR-145 and RNU6B.
Informed consent was obtained from patients as appropriate before specimens were collected. The study was approved by the ethics committee at Nara Medical University.
Differences in measures of continuous variables were analyzed using ANOVA or the nonparametric Mann–Whitney and Kruskal-Wallis tests. Results were analyzed using one-way ANOVA and Turkey’s post hoc test. Two-tailed Student’s t test was used to compare two data points. Results with p < 0.05 were considered significant.
miR-145 suppresses cell proliferation in bladder cancer cells
Expression of differentiation markers
miR-145 significantly induces NANOG, SOX2, OCT4, and E2F3
miR-145 significantly decreases syndecan-1 expression
Overexpression of miR-145 significantly suppressed syndecan-1 mRNA (Fig. 3b, Additional file 1: Figure S1D). Similarly, silencing of syndecan-1 by siRNA up-regulated some stem cell and differentiation markers (Fig. 3c). Taken together, the data suggest that miR-145 regulates cell proliferation and differentiation in urothelial carcinoma cells by down-regulating syndecan-1 while up-regulating some stem cell markers.
Expression of miR-145 in clinical bladder cancer tissues
In this study, we demonstrate for the first time that miR-145 in bladder cancer cells suppresses syndecan-1 and thereby regulates cell proliferation and expression of some markers of differentiation into squamous, glandular, and neuroendocrine cells. In addition, miR-145 induces expression of stem cell markers such as SOX2, OCT4, NANOG, and E2F3. Furthermore, the ability of miRNAs to reprogram cancer cells into cells with stem cell-like properties and low malignancy potential has been previously demonstrated in colon cancer , therefore miRNAs could regulate the fate of cancer cells. These results are in line with our recently published study, in which we demonstrate that syndecan-1, miR-126, and miR-149 modulate cell senescence by controlling expression of SOX2, NANOG, and OCT4 .
Differentiation into squamous or glandular cells is a hallmark of advanced-stage, invasive urothelial carcinomas with poor prognosis [24–26]. An isoform of p63, a marker of squamous cells, transactivates p53 target genes and induces cell cycle arrest and apoptosis [25, 26]. Up-regulation of MUC-1, a marker of glandular cells, promotes cell proliferation and invasion through epithelial-to-mesenchymal transition in some late-stage carcinomas including urothelial cancer [27–30]. UCHL-1 is overexpressed in pancreatic endocrine tumors, as well as in colorectal and lung cancers. This enzyme is a neuroendocrine marker that recognizes and hydrolyzes a peptide bond at the C-terminus of ubiquitin, and remodels synapses by controlling ubiquitin homeostasis [31–33]. In the current study, miR-145 provided to suppress cell proliferation and reverse urothelial carcinomas to the pluripotent cells with stem cell features through induction of senescence, then prompted differentiation to multiple lineages such as squamous, glandular and neuroendocrine cells. Taken together, miR-145 might contribute to the early step of divergent differentiation for invasive urothelial carcinomas.
miR-145 appears to be a tumor suppressor, the expression of which is reduced in various carcinomas including colon, lung, prostate, and breast cancer [34–37]. A number of recent studies have focused on the role of miR-145 in multiple cellular pathways underlying carcinogenesis. For example, miR-145 has been found to inhibit cancer cell growth, invasion, and metastasis by suppressing EGFR and NUDT1 in lung adenocarcinoma, FSCN-1 in esophageal squamous cell carcinoma, N-cadherin in gastric carcinoma, and IGF in hepatocellular carcinoma [38–41]. In our experiments, miR-145 expression in the urothelial carcinoma cell lines T24 and KU7 induces cell senescence without apoptosis. We have previously shown syndecan-1 to be important for the tumorigenicity and serial reproducibility of prostatic tumor-initiating cells, as well as for forming tumorigenic microspheres . Indeed, syndecan-1 might contribute to cell survival and progression, and is up-regulated in urothelial carcinomas, particularly in high-grade and aggressively invasive cancers . Together with these observations, miR-145 provides the basis for differentiation into multiple cell types, and for suppression of tumor-initiating cells.
Approximately 80 % of urothelial carcinomas are low-grade and non-invasive, and about 70 % are multifocal or recurrent with reasonably good prognosis . In contrast, high-grade and invasive cancers metastasize locally and distally. The capacity of such cancers to invade other tissues depends on intrinsic genetic factors, such as mutations in Ras or fibroblast growth factor receptor 3, as well as expression of p53 and RB tumor suppressor . Reduced E-cadherin expression compromises cell-cell adhesion, and is histologically associated with high-grade, invasive urothelial carcinoma . However, our data show that miR-145 overexpression induces E-cadherin, but not p53, and that miR-145 is more abundantly expressed in low-grade urothelial carcinomas than in high-grade cancers. Therefore, miR-145 may additionally suppress tumors by enhancing cell-cell adhesion through E-cadherin. Notably, E-cadherin expression is negatively correlated with syndecan-1 expression, which is in line with previous results .
In conclusion, miR-145 utilizes syndecan-1 to modulate cell proliferation, re-programming, and differentiation in urothelial carcinomas. Thus, miR-145 is a potential diagnostic or prognostic marker, as well as a target for therapy.
This research was supported in part by a Grant-in-Aid from the Ministry of Educaion, Culture, Sports, Science and Technology, Japan (26462424). We express our deep appreciation to Ms. Aya Asano for excellent technical assistance.
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- Miah S, Dudziec E, Drayton RM, Zlotta AR, Morgan SL, Rosario DJ, et al. An evaluation of urinary microRNA reveals a high sensitivity for bladder cancer. Br J Cancer. 2012;107:123–8.View ArticlePubMedPubMed CentralGoogle Scholar
- Puerta-Gil P, García-Baquero R, Jia AY, Ocaña S, Alvarez-Múgica M, Alvarez-Ossorio JL, et al. miR-143, miR-222, and miR-452 are useful as tumor stratification and noninvasive diagnostic biomarkers for bladder cancer. Am J Pathol. 2012;180:1808–15.View ArticlePubMedGoogle Scholar
- Alvarez-Garcia I, Miska EA. microRNA functions in animal development and human disease. Development. 2005;132:4653–62.View ArticlePubMedGoogle Scholar
- Morais DR, Reis ST, Viana N, Piantino CB, Massoco C, Moura C, et al. The involvement of miR-100 in bladder urothelial carcinogenesis changing the expression levels of mRNA and proteins of genes related to cell proliferation, survival, apoptosis and chromosomal stability. Cancer Cell Int. 2014;14:119.View ArticlePubMedPubMed CentralGoogle Scholar
- Lei Y, Li B, Tong S, Qi L, Hu X, Cui Y, et al. miR-101 suppresses vascular endothelial growth factor C that inhibits migration and invasion and enhances cisplatin chemosensitivity of bladder cancer cells. PLoS One. 2015;10:e0117809.View ArticlePubMedPubMed CentralGoogle Scholar
- Yamasaki T, Yoshino H, Enokida H, Hidaka H, Chiyomaru T, Nohata N, et al. Novel molecular targets regulated by tumor suppressors microRNA-1 and microRNA-133a in bladder cancer. Int J Oncol. 2012;40(6):1821–30.PubMedGoogle Scholar
- Tao J, Wu D, Xu B, Qian W, Li P, Lu Q, et al. microRNA-133 inhibits cell proliferation, migration and invasion in prostate cancer cells by targeting the epidermal growth factor receptor. Oncol Rep. 2012;27:1967–75.PubMedGoogle Scholar
- Bernfield M, Götte M, Park PW, Reizes O, Fitzgerald ML, Lincecum J, et al. Functions of cell surface heparin sulfate proteoglycans. Annu Rev Biochem. 1999;68:729–77.View ArticlePubMedGoogle Scholar
- Mennerich D, Vogel A, Klaman I, Dahl E, Lichtner RB, Rosenthal A, et al. Shift of syndecan-1 expression from epithelial to stromal cells during progression of solid tumours. Eur J Cancer. 2004;40:1373–82.View ArticlePubMedGoogle Scholar
- O’Connell FP, Pinkus JL, Pinkus GS. CD138 (syndecan-1), a plasma cell marker immunohistochemical profile in hematopoietic and nonhematopoietic neoplasms. Am J Clin Pathol. 2004;121:254–63.View ArticlePubMedGoogle Scholar
- Shimada K, Nakamura M, De Velasco MA, Tanaka M, Ouji Y, Konishi N. Syndecan-1, a new target molecule involved in progression of androgen-independent prostate cancer. Cancer Sci. 2009;100:1248–54.View ArticlePubMedGoogle Scholar
- Shimada K, Anai S, Fujii T, Tanaka N, Fujimoto K, Konishi N. Syndecan-1 (CD138) contributes to prostate cancer progression by stabilizing tumour-initiating cells. J Pathol. 2013;231:495–504.View ArticlePubMedGoogle Scholar
- Fujii T, Shimada K, Tatsumi Y, Fujimoto K, Konishi N. Syndecan-1 responsive microRNA-126 and 149 regulate cell proliferation in prostate cancer. Biochem Biophys Res Commun. 2015;456:183–9.View ArticlePubMedGoogle Scholar
- Mitsogiannis IC, Ioannou MG, Sinani CD, Melekos MD. Plasmacytoid transitional cell carcinoma of the urinary bladder. Urology. 2005;66:194.View ArticlePubMedGoogle Scholar
- Shimada K, Nakamura M, Ishida E, Konishi N. Urothelial carcinoma with plasmacytoid variants producing both human chorionic gonadotropin and carbohydrate antigen 19-9. Urology. 2006;68:891. e7-10.View ArticlePubMedGoogle Scholar
- Patriarca C, Di Pasquale M, Giunta P, Bergamaschi F. CD138-positive plasmacytoid urothelial carcinoma of the bladder. Int J Surg Pathol. 2008;16:215–7.View ArticlePubMedGoogle Scholar
- Demirovic A, Marusic Z, Lenicek T, Spajic B, Balicevic D, Tomas D, et al. CD138-positive plasmacytoid urothelial carcinoma of urinary bladder with focal micropapillary features. Tumori. 2010;96:358–60.PubMedGoogle Scholar
- Olsen DL, Anderson SR. Metastatic plasmacytoid urothelial carcinoma: a case report and review of the literature. Acta Cytol. 2014;58:108–12.View ArticlePubMedGoogle Scholar
- Shimada K, Nakamura M, De Velasco MA, Tanaka M, Ouji Y, Miyake M, et al. Role of syndecan-1 (CD138) in cell survival of human urothelial carcinoma. Cancer Sci. 2010;101:155–60.View ArticlePubMedGoogle Scholar
- Tazaki H, Tachibana M. Studies on KU-1 and KU-7 cells as an in vitro model of human transitional cell carcinoma of urinary bladder. Hum Cell. 1988;1:78–83.PubMedGoogle Scholar
- Garcia Del Muro X, Torregrosa A, Muñoz J, Castellsagué X, Condom E, Vigués F, et al. Prognostic value of the expression of E-cadherin and beta-catenin in bladder cancer. Eur J Cancer. 2000;36:357–62.View ArticlePubMedGoogle Scholar
- Wu XR. Urothelial tumorigenesis: a tale of divergent pathways. Nat Rev Cancer. 2005;5:713–25.View ArticlePubMedGoogle Scholar
- Miyazaki S, Yamamoto H, Miyoshi N, Wu X, Ogawa H, Uemura M, et al. A cancer reprogramming method using microRNAs as a novel therapeutic approach against colon cancer : research for reprogramming of cancer cells by microRNAs. Ann Surg Oncol. 2014; doi:https://doi.org/10.1245/s10434-014-4217-1.
- Zigeuner R, Tsybrovskyy O, Ratschek M, Rehak P, Lipsky K, Langner C. Prognostic impact of p63 and p53 expression in upper urinary tract transitional cell carcinoma. Urology. 2004;63:1079–83.View ArticlePubMedGoogle Scholar
- Yang A, Kaghad M, Wang Y, Gillett E, Fleming MD, Dötsch V, et al. p63, a p53 homolog at 3q27-29, encodes multiple products with transactivating, death-inducing, and dominant-negative activities. Mol Cell. 1998;2:305–16.View ArticlePubMedGoogle Scholar
- Urist MJ, Di Como CJ, Lu ML, Charytonowicz E, Verbel D, Crum CP, et al. Loss of p63 expression is associated with tumor progression in bladder cancer. Am J Pathol. 2002;161:1199–206.View ArticlePubMedPubMed CentralGoogle Scholar
- Fujii T, Shimada K, Anai S, Fujimoto K, Konishi N. ALKBH2, a novel AlkB homologue, contributes to human bladder cancer progression by regulating MUC1 expression. Cancer Sci. 2013;104(3):321–7.View ArticlePubMedGoogle Scholar
- Roy LD, Sahraei M, Subramani DB, Besmer D, Nath S, Tinder TL, et al. MUC1 enhances invasiveness of pancreatic cancer cells by inducing epithelial to mesenchymal transition. Oncogene. 2011;30:1449–59.View ArticlePubMedGoogle Scholar
- Liao G, Wang M, Ou Y, Zhao Y. IGF-1-induced epithelial-mesenchymal transition in MCF-7 cells is mediated by MUC1. Cell Signal. 2014;26:2131–7.View ArticlePubMedGoogle Scholar
- Gnemmi V, Bouillez A, Gaudelot K, Hémon B, Ringot B, Pottier N, et al. MUC1 drives epithelial-mesenchymal transition in renal carcinoma through Wnt/β-catenin pathway and interaction with SNAIL promoter. Cancer Lett. 2014;346:225–36.View ArticlePubMedGoogle Scholar
- Tomita T. PGP 9.5 immunocytochemical staining for pancreatic endocrine tumors. Islets. 2013;5:122–8.View ArticlePubMedPubMed CentralGoogle Scholar
- Akishima-Fukasawa Y, Ino Y, Nakanishi Y, Miura A, Moriya Y, Kondo T, et al. Significance of PGP9.5 expression in cancer-associated fibroblasts for prognosis of colorectal carcinoma. Am J Clin Pathol. 2010;134:71–9.View ArticlePubMedGoogle Scholar
- Kim JE, Koo KH, Kim YH, Sohn J, Park YG. Identification of potential lung cancer biomarkers using an in vitro carcinogenesis model. Exp Mol Med. 2008;40:709–20.View ArticlePubMedPubMed CentralGoogle Scholar
- Michael MZ, O’ Connor SM, van Holst Pellekaan NG, Young GP, James RJ. Reduced accumulation of specific microRNAs in colorectal neoplasia. Mol Cancer Res. 2003;1:882–91.PubMedGoogle Scholar
- Iorio MV, Ferracin M, Liu CG, Veronese A, Spizzo R, Sabbioni S, et al. MicroRNA gene expression deregulation in human breast cancer. Cancer Res. 2005;65:7065–70.View ArticlePubMedGoogle Scholar
- Yanaihara N, Caplen N, Bowman E, Seike M, Kumamoto K, Yi M, et al. Unique microRNA molecular profiles in lung cancer diagnosis and prognosis. Cancer Cell. 2006;9:189–98.View ArticlePubMedGoogle Scholar
- Porkka KP, Pfeiffer MJ, Waltering KK, Vessella RL, Tammela TL, Visakorpi T. MicroRNA expression profiling in prostate cancer. Cancer Res. 2007;67:6130–5.View ArticlePubMedGoogle Scholar
- Cho WC, Chow AS, Au JS. MiR-145 inhibits cell proliferation of human lung adenocarcinoma by targeting EGFR and NUDT1. RNA Biol. 2011;8:125–31.View ArticlePubMedGoogle Scholar
- Kano M, Seki N, Kikkawa N, Fujimura L, Hoshino I, Akutsu Y, et al. miR-145, miR-133a and miR-133b: Tumor-suppressive miRNAs target FSCN1 in esophageal squamous cell carcinoma. Int J Cancer. 2010;127:2804–14.View ArticlePubMedGoogle Scholar
- Gao P, Xing AY, Zhou GY, Zhang TG, Zhang JP, Gao C, et al. The molecular mechanism of microRNA-145 to suppress invasion-metastasis cascade in gastric cancer. Oncogene. 2013;32:491–501.View ArticlePubMedGoogle Scholar
- Law PT, Ching AK, Chan AW, Wong QW, Wong CK, To KF, et al. MiR-145 modulates multiple components of the insulin-like growth factor pathway in hepatocellular carcinoma. Carcinogenesis. 2012;33:1134–41.View ArticlePubMedGoogle Scholar
- Chatterjee SJ, Datar R, Youssefzadeh D, George B, Goebell PJ, Stein JP, et al. Combined effects of p53, p21, and pRb expression in the progression of bladder transitional cell carcinoma. J Clin Oncol. 2004;22:1007–13.View ArticlePubMedGoogle Scholar