Role of epithelial-to-mesenchymal transition (EMT) in drug sensitivity and metastasis in bladder cancer

Significance of CLASP2 expression in prognosis for muscle-invasive bladder cancer patients: A propensity score-based analysis

BACKGROUND

Cytoplasmic linker-associated protein 2 (CLASP2) belongs to a family of microtubule plus-end tracking proteins that localize to the distal ends of microtubules and is involved in various microtubule-dependent processes. We previously showed that CLASP2 is involved in the epithelial-to-mesenchymal transition of bladder urothelial cancer. This research aimed to explore the significance of CLASP2 expression as a prognostic marker for muscle-invasive bladder urothelial cancer (MIBC) patients after radical cystectomy-pelvic lymph node dissection (RC-PLND).

METHODS

CLASP2 expression was analyzed in 76 benign bladder tissues and 160 MIBC tissues by tissue immunohistochemistry. Survival analysis and multiple regression analysis following propensity score matching were performed to investigate the correlation between high CLASP2 expression and MIBC patients' survival.

RESULTS

CLASP2 expression was increased in MIBC patients, especially those with high-stage tumors or lymph node metastasis. In the follow-up of MIBC patients after propensity score matching, whether MIBC patients received adjuvant chemotherapy after RC-PLND, high CLASP2 expression was significantly associated with a poor prognosis. MIBC patients with low CLASP2 expression who received adjuvant chemotherapy tended to have an improved survival prognosis.

CONCLUSION

CLASP2 expression is correlated with malignant progression of MIBC. High CLASP2 expression predicted a poor prognosis for MIBC patients after RC-PLND.

p53-Mediated PI3K/AKT/mTOR Pathway Played a Role in PtoxDpt-Induced EMT Inhibition in Liver Cancer Cell Lines

Epithelial-mesenchymal transition (EMT) involves metastasis and drug resistance; thus, a new EMT reversing agent is required. It has shown that wild-type p53 can reverse EMT back to epithelial characteristics, and iron chelator acting as a p53 inducer has been demonstrated. Moreover, recent study revealed that etoposide could also inhibit EMT. Therefore, combination of etoposide with iron chelator might achieve better inhibition of EMT. To this end, we prepared di-2-pyridineketone hydrazone dithiocarbamate S-propionate podophyllotoxin ester (Ptox^Dpt) that combined the podophyllotoxin (Ptox) structural unit (etoposide) with the dithiocarbamate unit (iron chelator) through the hybridization strategy. The resulting Ptox^Dpt inherited characteristics from parent structural units, acting as both the p53 inducer and topoisomerase II inhibitor. In addition, the Ptox^Dpt exhibited significant inhibition in migration and invasion, which correlated with downregulation of matrix metalloproteinase (MMP). More importantly, Ptox^Dpt could inhibit EMT in the absence or presence of TGF-β1, concomitant to the ROS production, and the additional evidence revealed that Ptox^Dpt downregulated AKT/mTOR through upregulation of p53, indicating that Ptox^Dpt induced EMT inhibition through the p53/PI3K/AKT/mTOR pathway.

Cause-and-Effect relationship between FGFR1 expression and epithelial-mesenchymal transition in EGFR-mutated non-small cell lung cancer cells

OBJECTIVES

Increased FGFR1 expression is associated with resistance to tyrosine kinase inhibitors (TKIs) in EGFR-mutated NSCLC cells and often concomitant with epithelial to mesenchymal transition (EMT). However, the cause-and-effect relationship between increased FGFR1 expression and EMT in the genetic background of EGFR-mutated non-small cell lung cancer (NSCLC) cells is not clear. Previous studies have specifically addressed the relationship between EMT and increased FGFR1 expression in the context of simultaneous TKI-mediated blocking of EGFR-signaling. Here, in the context of EGFR-mutated NSCLC cells with active EGFR-signaling, we have examined whether increased FGFR1 expression drives EMT or is an EMT passenger event.

MATERIALS AND METHODS

For cause-and-effect analyses between EMT and FGFR1 expression, including expression of alternative spliced FGFR1 isoforms, we used CRISPR-dCAS9-SAM-mediated induction of the endogenous FGFR1 and ZEB1 genes, as well as biochemical EMT-induction, in PC9 and HCC827 NSCLC cell lines harboring activating EGFR-mutations.

RESULTS

We find that FGFR1 expression correlates with a ZEB1-associated EMT gene expression profile in NSCLC cells. In experiments using NSCLC cell lines harboring activating EGFR-mutations we show that CRISPR-dCAS9-SAM-mediated induction of FGFR1 expression is neither driving an increase in ZEB1 expression nor EMT characteristics. However, CRISPR-dCAS9-SAM-mediated induction of ZEB1 expression drives EMT characteristics and an increase in FGFR1 expression. Biochemical induction of EMT also drives an increase in FGFR1 expression.

CONCLUSION

From our findings concerning the cause-and-effect relationship in the genetic background of EGFR-mutated NSCLC cells, we conclude that an increase in ZEB1 expression is a driver of EMT resulting in concomitant increased FGFR1 expression, whereas an increase in FGFR1 expression is insufficient to drive concomitant EMT.

Rapid activation of epithelial-mesenchymal transition drives PARP inhibitor resistance in Brca2-mutant mammary tumours

Tumours defective in the DNA homologous recombination repair pathway can be effectively treated with poly (ADP-ribose) polymerase (PARP) inhibitors; these have proven effective in clinical trials in patients with BRCA gene function-defective cancers. However, resistance observed in both pre-clinical and clinical studies is likely to impact on this treatment strategy. Over-expression of phosphoglycoprotein (P-gp) has been previously suggested as a mechanism of resistance to the PARP inhibitor olaparib in mouse models of Brca1/2-mutant breast cancer. Here, we report that in a Brca2 model treated with olaparib, P-gp upregulation is observed but is not sufficient to confer resistance. Furthermore, resistant/relapsed tumours do not show substantial changes in PK/PD of olaparib, do not downregulate PARP1 or re-establish double stranded DNA break repair by homologous recombination, all previously suggested as mechanisms of resistance. However, resistance is strongly associated with epithelial-mesenchymal transition (EMT) and treatment-naïve tumours given a single dose of olaparib upregulate EMT markers within one hour. Therefore, in this model, olaparib resistance is likely a product of an as-yet unidentified mechanism associated with rapid transition to the mesenchymal phenotype.

Yes-associated protein 1 promotes bladder cancer invasion by regulating epithelial-mesenchymal transition

PURPOSE

To investigate the expression of Yes-associated protein 1 (YAP1) in bladder cancer, and to study its role in regulating epithelial-mesenchymal transition in bladder cancer cells.

MATERIAL AND METHODS

The expression of YAP1, vimentin, and E-cadherin was detected by immunohistochemistry in bladder cancer and para-carcinoma tissues. The relation between expression levels and overall survival of patients was evaluated by Kaplan-Meier estimates. Furthermore, YAP1 expression was knocked down in T24 and UMUC3 bladder cancer through transfection with YAP1-targeted small interfering RNA (siRNA), and the impact on invasiveness and epithelial-mesenchymal transition was detected.

RESULTS

Expression levels of YAP1 were higher in bladder cancer tissues, and increased YAP1 expression significantly correlated with poor patient outcomes and poor overall survival in bladder cancer patients. Furthermore, YAP1 siRNA significantly attenuated the invasion of bladder cancer cells and could reverse their epithelial-mesenchymal transition.

CONCLUSION

YAP1 appears to play an important role in bladder cancer progression and is highlighted as a novel potential therapeutic target.

CCL17-CCR4 axis promotes metastasis via ERK/MMP13 pathway in bladder cancer

As an important chemokine receptor, the role of CCR4 in the progression of bladder cancer (BC) remains unknown. In this study, we have shown that CCR4 expression was upregulated in bladder carcinoma tissues compared with adjacent nontumor tissues. Kaplan-Meier survival analysis revealed that CCR4 expression was an independent prognostic risk factor in BC patients, and the addition of CCL17 induced CCR4 production and promoted migration and invasion of BC cells. In addition, CCR4 knockdown significantly attenuated the migratory and invasive capabilities of BC cells. Mechanistically, CCL17-CCR4 axis is involved in ERK1/2 signaling and could mediate the migration and invasion of BC cells by regulating MMP13 activation. This study suggests that CCR4 might represent a promising prognostic biomarker and a potential therapeutic option for BC.

Molecular characterization of low grade and high grade bladder cancer

Background

Bladder cancer (BC) is the 9^th most common cancer diagnosis worldwide. Low grade (LG) represents 70% of all BCs, characterized by recurrence and rare ability (10–15%) to progress to high grade (HG) and invade. The remaining 30% is high grade (HG), fast invasive BC, which is resistant to therapy. Identifying biomarkers for predicting those tumors able to progress is a key goal for patient outcome improvement. This study focuses on the most promising prognostic markers.

Materials and methods

TP53 and FGFR3 mutational status, Survivin, CK19, CK20, E-cadherin and CD44 gene expression analysis were performed on 66 BCs.

Results

Survivin was found associated to tumor grade (p<0.05). Moreover, Survivin correlated with CD44 in TP53 wild type (p = 0.0242) and FGFR3 wild type (p = 0.0036) tumors. In particular the Survivin-CD44 correlation was associated to HG FGFR3 wild type BCs (p = 0.0045). Unsupervised hierarchical clustering based on gene expression data identified four distinct molecular groups reflecting the patient histology (p = 0.038).

Conclusion

We suggest Survivin, both as a biomarker associated to G3 BCs but negatively related to TP53 mutational status, and as a potential novel therapeutic target.

CCL18 enhances migration, invasion and EMT by binding CCR8 in bladder cancer cells

Increased expression of CCL18 has been observed in various malignancies and in the urine samples of patients with bladder cancer (BC). However, the roles of CCL18 in the development, progression and metastasis of BC remain unclear. The present study demonstrated that CCL18 expression was significantly associated with advanced clinical stages of BC. Furthermore, exogenous CCL18 promoted cell invasion and migration, and induced cell epithelial-mesenchymal transition (EMT) in BC cells. Western blotting demonstrated that E-cadherin, an epithelial marker, was decreased, whereas matrix metalloproteinase (MMP)-2 and vascular endothelial growth factor (VEGF)-C were increased in CCL18-treated cells. Blocking CCR8 via a small molecule inhibitor or short hairpin (sh)RNA mitigated the decrease in E-cadherin, and increase in MMP-2 and VEGF-C, caused by human recombinant (r)CCL18. CCR8 knockdown by shRNA reversed rCCL18-induced cancer cell invasion, migration and EMT. In conclusion, these data suggested that CCL18 may promote migration, invasion and EMT by binding CCR8 in BC cells. Inhibition of CCL18 activity by blocking CCR8 could be a potential therapeutic strategy for preventing the progression of BC.

Steroid sulfatase promotes invasion through epithelial-mesenchymal transition and predicts the progression of bladder cancer

Androgen signal has been recently suggested to be associated with the progression of bladder cancer. Steroid sulfatase (STS) is a steroid sulfate activation enzyme, considered to be one of the key enzymes in the androgen signaling pathway. However, the role of STS in bladder cancer has not been elucidated. The purpose of the present study was to determine the clinical and functional significance of STS in bladder cancer. Immunohistochemical analysis of surgical specimens obtained by radical cystectomy (n=114) demonstrated that overexpression of STS was associated with the invasion of bladder cancer, as evidenced by the incidence of STS-positive cancers (11.5 and 37.1% in non-muscle invasive and muscle invasive bladder cancers, respectively; P=0.003). STS-positive cancer demonstrated shorter recurrence-free survival and cancer-specific survival (P=0.0027 and 0.0030, respectively). Furthermore, knockdown of STS significantly reduced cell migration and invasion capacities of bladder cancer cells (P<0.001 and P=0.005, respectively), accompanied by the upregulation of E-cadherin and downregulation of vimentin. In summary, the present study demonstrated that STS promotes the invasion capability of bladder cancer via regulation of the epithelial-mesenchymal transition, and may be a useful marker for predicting the progression of bladder cancers.

Role of micro-RNAs in breast cancer surgery

BACKGROUND

The management of breast cancer has changed dramatically in the molecular era. Micro-RNAs can contribute to multiple facets of cancer surgery.

METHODS

This narrative review, based on years of research on the role of micro-RNAs, focused on the potential of these small, robust RNAs to influence all aspects of breast cancer surgery.

RESULTS

Micro-RNAs have a potential role as biomarkers in the diagnosis, prognosis and evaluation of response to therapy in breast cancer. They may also contribute to future therapeutic strategies.

CONCLUSION

The molecular era has changed understanding of cancer. Micro-RNAs have the potential for use in personalized cancer strategies.

Inactivation of ATF-2 enhances epithelial-mesenchymal transition and gemcitabine sensitivity in human pancreatic cancer cells

OBJECTIVE

This work aimed to study the activating transcription factor 2 or AMP-dependent transcription factor-2 (ATF-2) inhibition mediated gemcitabine sensitivity in human pancreatic cancer cells.

METHODS

The protein and messenger RNA expressions of ATF-2 in 42 pancreatic cancer tissues and adjacent nontumorous tissues were detected. Kaplan-Meier survival analysis was performed based on the expression level of ATF-2 protein in tumor tissues. Then the pancreatic cancer cells were transduced with ATF-2-expressing lentivirus and small interfering RNAs (siRNAs) to investigate the effect of ATF-2 on pancreatic cancer cell invasion, epithelium to mesenchyme transition, apoptosis, and gemcitabine sensitivity.

RESULTS

The expression of phosphorylated (p)-ATF-2 protein was upregulated in pancreatic cancer tissues compared with adjacent nontumorous tissues. Patients with relative higher p-ATF-2 level showed significantly lower survival time. Then we found that the transfection ATF-2 siRNA into BxPC3 cells inhibited cell proliferation, invasion, and epithelium to mesenchyme transition, but enhanced cell apoptosis. These changes could be enhanced by the additional administration of gemcitabine. In addition, we confirmed that the overexpression of ATF-2 in Panc-1 cells promoted cell invasion and epithelium to mesenchyme transition.

CONCLUSION

We concluded that inhibition-promoted ATF-2 expression was responsible for epithelium to mesenchyme transition and invasion of pancreatic cancer cells, while the inhibition of ATF-2 confers to gemcitabine sensitivity in human pancreatic cancer cells in vitro.

Starvation-induced autophagy promotes the invasion and migration of human bladder cancer cells via TGF-β1/Smad3-mediated epithelial-mesenchymal transition activation

The biological characteristics of bladder cancer include enhanced invasion and migration, which are the main causes of death in patients. Starvation is a typical feature of the bladder cancer microenvironment and can induce autophagy. Autophagy has an important relationship with the invasion and migration of tumors. However, the role of autophagy in the invasion and migration of bladder cancer cells remains unclear. Hence, the aim of the current study was to clarify this role and underlying mechanism. In this study, we found that starvation enhanced the epithelial-mesenchymal transition (EMT)-mediated invasion and migration of T24 and 5637 cells while inducing autophagy. The inhibition of autophagy with chloroquine (CQ) or 3-methyladenine (3MA) decreased EMT-mediated invasion and migration. In addition, the expression of transforming growth factor 1 (TGF-β1) and phosphorylated Smad3 (p-Smad3) increased after starvation. The inhibition of autophagy with CQ or 3MA also decreased the expression of TGF-β1 and p-Smad3. The inhibitor of TGF-β receptor sb431542 also inhibited the invasion, migration, and EMT of T24 and 5637 cells during starvation. Furthermore, recombinant TGF-β1 induced autophagy and inhibition of the TGF-β/Smad signaling pathway with sb431542 suppressed autophagy. In summary, our results suggested that autophagy promotes the invasion and migration of bladder cancer cells by inducing EMT through the TGF-β1/Smad3 signaling pathway. Moreover, autophagy and TGF-β1 can form a positive feedback loop to synergistically promote invasion and migration. Thus, our findings may provide a theoretical basis for the prevention of invasion and migration in bladder cancer.

GeneExpressScore Signature: a robust prognostic and predictive classifier in gastric cancer

Although several prognostic signatures have been developed for gastric cancer (GC), the utility of these tools is limited in clinical practice due to lack of validation with large and multiple independent cohorts, or lack of a statistical test to determine the robustness of the predictive models. Here, a prognostic signature was constructed using a least absolute shrinkage and selection operator (LASSO) Cox regression model and a training dataset with 300 GC patients. The signature was verified in three independent datasets with a total of 658 tumors across multiplatforms. A nomogram based on the signature was built to predict disease-free survival (DFS). Based on the LASSO model, we created a GeneExpressScore signature (GES_GC ) classifier comprised of eight mRNA. With this classifier patients could be divided into two subgroups with distinctive prognoses [hazard ratio (HR) = 4.00, 95% confidence interval (CI) = 2.41-6.66, P < 0.0001]. The prognostic value was consistently validated in three independent datasets. Interestingly, the high-GES_GC group was associated with invasion, microsatellite stable/epithelial-mesenchymal transition (MSS/EMT), and genomically stable (GS) subtypes. The predictive accuracy of GES_GC also outperformed five previously published signatures. Finally, a well-performed nomogram integrating the GES_GC and four clinicopathological factors was generated to predict 3- and 5-year DFS. In summary, we describe an eight-mRNA-based signature, GES_GC , as a predictive model for disease progression in GC. The robustness of this signature was validated across patient series, populations, and multiplatform datasets.

RCAN1.4 acts as a suppressor of cancer progression and sunitinib resistance in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is one of the most common malignant tumors in the urinary system, and its incidence continues to increase. Regulator of calcineurin 1 (RCAN1), one of the genes on chromosome 21, is a crucial mediator of tumor inhibition. RCAN1.4 is best characterized as an endogenous inhibitor of the phosphatase calcineurin, and it has been observed to be downregulated in numerous types of cancer. However, its essential function remains unclear in ccRCC. In the present study, we found that RCAN1.4 expression was frequently downregulated in renal cell carcinoma tissues and cells and was inversely correlated with various clinicopathological parameters. Low RCAN1.4 expression was associated with poor overall survival and disease-free survival and could act as a diagnostic indicator in ccRCC patients. Furthermore, the overexpression of RCAN1.4 inhibited cell proliferation, migration and invasion, whereas RCAN1.4 knockdown promoted these functions in ccRCC cell lines. In addition, RCAN1.4 expression was downregulated in sunitinib-resistant renal cancer cell lines, and inhibition of RCAN1.4 promoted sunitinib resistance. We also found that RCAN1.4 could regulate epithelial-mesenchymal transition (EMT) and the expression of HIF2α in sunitinib-resistant cell lines. Taken together, these findings indicate that downregulation of RCAN1.4 may be crucial for the metastasis of ccRCC and may induce sunitinib resistance. RCAN1.4 may act as a prognostic indicator and potential therapeutic target for ccRCC.

MicroRNA-3619-5p suppresses bladder carcinoma progression by directly targeting β-catenin and CDK2 and activating p21

Current studies indicate that microRNAs (miRNAs) are widely decreased in various tumors and function as tumor suppressors by inhibiting cancer cell proliferation, survival, invasion, and migration. The potential application of using miRNAs to predict therapeutic responses to multiple types of cancer treatment holds high promise. In current study, we demonstrate that miR-3619-5p is downregulated in bladder cancer (BCa) tissues and cells. Exogenous overexpression of miR-3619-5p in BCa cells inhibits proliferation, migration, and invasion. Moreover, a nude mouse xenograft model shows that miR-3619-5p inhibits BCa cell growth. We also demonstrate that miR-3619-5p leads to the activation of p21 by targeting its promoter in BCa cells. Enforced miR-3619-5p expression consistently leads to the downregulation of β-catenin and cyclin-dependent kinase 2 (CDK2) through predicted binding sites within the β-catenin and CDK2 3′-untranslated regions (UTRs), respectively. Moreover, β-catenin and CDK2 knockdown is able to mimic BCa cells growth and metastasis effects induced by overexpressing miR-3619-5p. We further confirm that miR-3619-5p inhibits Wnt-β-catenin signal pathway and EMT progression in BCa cells. We also found that miR-3619-5p-induced growth arrest and metastasis inhibition are p21-dependent in BCa cells. Taken together, these results confirm that miR-3619-5p plays a tumor suppressive role in BCa by interfering with cell growth and metastasis and may serve as a potential therapeutic target in BCa treatment.

Reduction of Membrane Protein CRIM1 Decreases E-Cadherin and Increases Claudin-1 and MMPs, Enhancing the Migration and Invasion of Renal Carcinoma Cells

CRIM1 is a membrane protein that has been reported to be related to cell proliferation. CRIM1 is expressed in renal carcinoma cells, but its involvement in proliferation and malignant transformation remains unclear. We analyzed whether alterations in the characteristics of cancer cells are observed following knockdown of CRIM1. Decreased expression of CRIM1 did not affect proliferation or anchorage-independent growth. The results of wound healing and invasion assays showed that reduced expression of CRIM1 increased cells' migratory and invasive abilities. Expression analysis of factors involved in migration and invasion in CRIM1-knockdown cells revealed that expression of the cell adhesion factor E-cadherin declined and expression of claudin-1, which is upregulated in metastatic cancer cells, increased. In addition, increased expression of matrix metalloproteinase (MMP) 2 and MMP9, protease essential for cancer cell invasiveness, was observed. Furthermore, an increase in phosphorylated focal adhesion kinase (FAK), which increases cell migration, was observed. Increased expression of the E-cadherin transcription repressors Snail, Slug, and ZEB-1 were observed, and mRNA levels of E-cadherin were decreased. Therefore, expression of E-cadherin is thought to be decreased by both suppression of E-cadherin mRNA expression and promotion of degradation of the E-cadherin protein. In addition, expression of CRIM1 was decreased in renal cancer cells undergoing epithelial-mesenchymal transition (EMT) stimulated by tumor necrosis factor alpha (TNF-α). Thus, CRIM1 regulates the expression of several EMT-related factors and appears to play a role in suppressing migration and invasion through control of EMT.

Predictive Value of CD44 in Muscle-Invasive Bladder Cancer and Its Relationship with IL-6 Signaling

BACKGROUND

CD44, a cancer stem cell surface marker, is associated with treatment resistance and prognosis in some cancers. In the present study, we examined the predictive value of CD44 in muscle-invasive bladder cancer (MIBC).

METHODS

We retrospectively analyzed the clinical outcomes of 105 MIBC patients and correlated these outcomes with the expression of CD44. Furthermore, the bladder cancer cell lines HT1197 and MB49 were selected for cellular and animal experiments to investigate the correlation between CD44 and tumor aggressiveness.

RESULTS

Analysis of clinical specimens indicated that CD44 staining was significantly associated with a higher clinical stage, higher locoregional failure rate, and lower disease-specific survival rate for MIBC patients. Using cellular experiments and orthotopic tumor models, we showed that CD44+ bladder cancer cells had a higher invasion ability and augmented epithelial-mesenchymal transition (EMT) compared with CD44 cells. There was a significant correlation between interleukin (IL)-6 and CD44 levels noted by in vitro testing, and clinical samples. Blockade of IL-6 attenuated the expression of CD44, cancer stem-cell-like properties, and aggressive tumor behavior in vitro and in vivo. The related changes included the attenuated STAT3 activation and EMT, and decreased programmed death ligand 1-mediated T-cell suppression.

CONCLUSION

Our findings suggest that CD44 expression is positively associated with tumor aggressiveness in bladder cancer, and activated IL-6 signaling provides a suitable microenvironment for the induction of CD44 expression.

Predicting the tumorigenic phenotype of human bladder cancer cells by combining with fetal rat mesenchyme

BACKGROUND

In nonmuscle invasive bladder cancer patients, prediction of pTa and pT1 bladder cancer recurrence and progression must be established. Micropapillary structures have been defined as small clusters of invasive cancer cells having features of the epithelial-mesenchymal transition. Since the stromal microenvironment helps to induce the epithelial-mesenchymal transition, interactions between cancer cells and stroma should be closely examined to predict the tumorigenic phenotype of human bladder cancer cells.

MATERIALS AND METHODS

To investigate differences in the responsiveness of cancer cells to stroma, we combined 3 established human bladder cancer cell lines (high-grade T24 and UM-UC-3 cells, and low-grade papillary RT4 cells) with fetal rat mesenchyme.

RESULTS

Among 3 bladder cancer cell lines, the expression profiles of p63 isoforms were distinct, i.e., p63γ in T24 cells, p63β in UM-UC-3 cells, and p63α in RT4 cells. Tumors formed by T24 cells combined with fetal mesenchyme formed micropapillary-like structures, whereas those formed by T24 cells alone did not. T24 cells combined with fetal mesenchyme showed poor differentiation, e.g., innumerable chromatic atypia in the nuclei, higher levels of chromatic condensation, and increased nucleoli. In contrast, both UM-UC-3 and RT4 cells combined with fetal mesenchyme did not form micropapillary-like structures. Ki-67 and p63 labeling indices were significantly elevated by combining fetal mesenchyme with T24 cells but not with the others.

CONCLUSIONS

By mixing cancer cells with fetal mesenchyme, our data demonstrated that formation of micropapillary-like structures may predict the tumorigenic phenotype of invasive bladder cancer cells. Taken together, distinct expression profiles of p63 isoforms may predict poor outcomes in invasive bladder cancer.

Increased expression of TNFRSF14 indicates good prognosis and inhibits bladder cancer proliferation by promoting apoptosis

Despite advances in management, bladder cancer remains a principal cause of cancer‑associated complications. Tumor necrosis factor receptor superfamily member 14 (TNFRSF14) is dysregulated in certain types of cancer; however, limited data are available on the expression and function of TNFRSF14 in bladder cancer. In the present study, the aim was to evaluate the expression and biological functions of TNFRSF14 in bladder cancer. Firstly, the expression levels of TNFRSF14 in bladder cancer tissue were examined using The Cancer Genome Atlas (TCGA) database. Secondly, reverse transcription‑quantitative polymerase chain reaction was utilized to investigate the expression levels of TNFRSF14 in the T24, SW780 and EJ‑M3 bladder cancer cell lines. Transfection and Cell Counting kit‑8 (CCK‑8) assay was used to evaluate whether TNFRSF14 overexpression or silencing would have an effect on cell proliferation of T24 and EJ‑M3 cells. In addition, TNFRSF14‑induced apoptotic cells were identified using Annexin V‑fluorescein isothiocyanate and propidium iodide staining. Western blot analysis was used to detect proteins associated with the phosphatidylinositol 3‑kinase pathway. According to the TCGA dataset, the expression levels TNFRSF14 were decreased in bladder cancer tissue compared with in normal control samples. Patients with bladder cancer exhibiting low expression levels of TNFRSF14 had a worse prognosis compared to those with high expression levels of TNFRSF14. Overexpression of TNFRSF14 in T24 cells led to increased apoptosis and inhibited cell proliferation in vitro. Western blotting demonstrated that TNFRSF14 overexpression increased the expression levels of caspase3‑p17 in T24 cells, but significantly decreased the expression levels of phosphorylated (p)‑protein kinase B (AKT) and P70 S6 kinase (P70). TNFRSF14 silencing in EJ‑M3 cells enhanced cell growth, inhibited cell apoptosis, increased the expression levels of p‑AKT and P70, and decreased the expression levels of caspase3‑p17. In conclusion, TNFRSF14 may serve a tumor suppressive role in bladder cancer by inducing apoptosis and suppressing proliferation, and act as a novel prognostic biomarker for bladder cancer.

Transcriptomic analysis of high-throughput sequencing about circRNA, lncRNA and mRNA in bladder cancer

An increasing number of studies have revealed that long noncoding RNA (lncRNA) and circular RNA (circRNA) participate in the carcinogenesis and progression of tumors. However, most of these noncoding RNAs are of unknown function or without annotation. We carried out high-throughput sequencing to investigate the differential expression of lncRNAs and circRNAs and their biological functions in four coupled bladder cancer and adjacent noncancerous tissues. We identified significant differentially expressed transcripts and genes and acquired their annotations from the RefSeq and circBase databases, then confirmed the expression of randomly selected RNAs with quantitative real-time PCR. We also constructed a coding-noncoding co-expression (CNC) network and a competing endogenous RNA (ceRNA) network to predict the functions of these RNAs using well-studied protein-coding mRNA. Compared with adjacent tissues, 56 lncRNAs, 34 circRNAs and 467 protein-coding mRNAs were upregulated while 32 lncRNAs, 84 circRNAs and 326 protein-coding mRNAs were downregulated in cancer tissues. Co-expression analysis showed that expression of LINC00885 were correlated with GATA3 expression. The ceRNA network indicated that lncRNA MIR194-2HG, AATBC and circRNA PGM5 could harbor bladder cancer-related microRNA (miRNA) recognition elements. We performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis to ascertain the biological function of significantly dysregulated genes. Cell cycle and cell division pathways related to proliferation and apoptosis were obvious in enriched terms. Comprehensive analysis indicated that the dysregulated lncRNAs and circRNAs could participate in the genesis and progression of bladder cancer. Our approach may therefore be valuable for detecting novel transcripts, discovering new biomarkers for bladder cancer and expounding the pathogenic mechanisms of this disease.

Human HLA‑F adjacent transcript 10 promotes the formation of cancer initiating cells and cisplatin resistance in bladder cancer

Epithelial to mesenchymal transition (EMT) serves important roles in tumor invasion, metastasis, formation of cancer initiating cells (CICs) and drug resistance. HLA‑F adjacent transcript 10 (FAT10) has been proposed as an oncogene in bladder cancer. However, the functional contribution of FAT10 to EMT and the formation of CICs remains unclear in bladder cancer. The present study reports that FAT10 protein expression is upregulated in bladder cancer cell lines, and the overexpression of FAT10 promotes EMT and the formation of CICs in bladder cancer UMUC‑3 cells. In addition, increased expression of FAT10 in tumor tissue was associated with shorter overall survival and progression free survival in Chinese patients with bladder cancer. Overexpression of FAT10 promotes cisplatin‑resistant bladder cancer formation. These results indicated FAT10 may be a novel target for the treatment of bladder cancer.

MCT1 regulates aggressive and metabolic phenotypes in bladder cancer

Background: Monocarboxylate transporter isoform 1 (MCT1) is an important molecule in mediating lactate transportation. Recent studies have shown an oncogenic role of MCT1 in cancer development.

Methods: In this study, we aimed to investigate the expression and role of MCT1 in bladder cancer (BCa). MCT1 expression was detected in 124 BCa tissues and their clinicopathological significance was analyzed. We also used The Cancer Genome Atlas database to explore the prognostic association of MCT1 with BCa. Cell proliferation, migration and invasion assays were performed on BCa cells in which MCT1 was downregulated. The effect of MCT1 on BCa cell aerobic glycolysis, as well as its association with HIF-1α, was tested.

Results: We found that high MCT1 expression correlated with lymph node and distant metastasis. Patients with high-MCT1 expression showed shorter overall survival than those with low-MCT1 expression. Knockdown of MCT1 inhibited BCa cell proliferation, migration and invasion, and affected expression of epithelial-mesenchymal transition related proteins. Downregulation of MCT1 decreased lactate levels in cell medium, as well as HK2, GLUT1 and LDHB expression. In addition, MCT1 expression was partly dependent on HIF-1α.

Conclusions: Taken together, our study has shown a prognostic role of MCT1 in BCa, and provided potential diagnostic and therapeutic options for BCa patients.

Synergistic antitumor activity of aspirin and erlotinib: Inhibition of p38 enhanced aspirin plus erlotinib-induced suppression of metastasis and promoted cancer cell apoptosis

High-dose erlotinib is effective for non-small cell lung cancer patients with brain metastases. The aim of the present study was to investigate whether aspirin could increase the anti-proliferative and anti-metastatic effects of regular erlotinib treatment. The data demonstrated that combining aspirin with erlotinib significantly induced apoptosis and inhibited tumor cell proliferation in several human cancer types. Furthermore, aspirin plus erlotinib significantly induced the activation of E-cadherin and suppression of p38. The data also indicated that the p38/E-cadherin pathway may be involved in the apoptosis caused by the combination of aspirin and erlotinib. As p38 and E-cadherin also serve a key role in epithelial-to-mesenchymal transition (EMT) and cancer metastasis, we hypothesized that the combination of aspirin and erlotinib may significantly inhibit tumor metastasis. First, aspirin plus erlotinib achieved potent inhibition of cancer cell migration and invasion, which are crucial for cancer metastasis. Next, the results demonstrated that aspirin plus erlotinib inhibited angiogenesis by suppressing endothelial cell migration and invasion. Moreover, it was confirmed that aspirin plus erlotinib exerted synergistic anti-angiogenic effects. Finally, the synergistic anti-proliferative and anti-metastatic effects of the combination of aspirin with erlotinib were further validated in an A549 xenograft model in vivo. In conclusion, aspirin plus erlotinib may be an effective combination regimen for patients with metastatic cancer.

Gamma-Klotho exhibits multiple roles in tumor growth of human bladder cancer

Alpha-Klotho (KLα) and beta-Klotho (KLβ) have recently been reported to correlate with cancer prognosis in some malignancies and we previously reported the association between KLα, KLβ, and urothelial carcinoma of the bladder (UCB), indicating that KLβ acts as a tumor promoter. However, the association between gamma-Klotho (KLγ) and cancer prognosis remains unclear. In the present study, we evaluated the association between KLγ and UCB. To evaluate the effect of KLγ on human bladder cancer cell lines in vitro assays were performed. Exogenous KLγ increased the ability of human bladder cancer cells to proliferate, migrate, invade, form colonies, and provide anchorage-independent growth potential. In in vivo assays, eighteen mice bearing xenografts inoculated using UM-UC-3, were randomly divided into three groups and treated with a small interfering RNA (siRNA) by intratumoral administration once a week for four weeks. Knockdown of KLγ with siRNA led to a dramatic change in tumor growth and suggested that KLγ had effects on tumor growth, including promotion of cell proliferation, inhibition of apoptosis, and enhancement of the epithelial-mesenchymal transition. To confirm the study, human tissue samples were used and patients were divided into two groups according to KLγ expression level. High expression of KLγ was significantly associated with higher stage and grade cancer and the presence of lymphovascular invasion compared to patients with lower expression of KLγ. Our results suggest that KLγ plays an important role in tumor invasion and progression and these results may lead to the development of new therapies and diagnostic methods for UCB.

Employing an orthotopic model to study the role of epithelial-mesenchymal transition in bladder cancer metastasis

Epithelial-to-mesenchymal transition (EMT) has been implicated in the progression of bladder cancer. To study its contribution to bladder cancer metastasis, we established new xenograft models derived from human bladder cancer cell lines utilizing an orthotopic “recycling” technique that allowed us to isolate and examine the primary tumor and its corresponding circulating tumor cells (CTC’s) and metastatic lesions. Using whole genome mRNA expression profiling, we found that a reversible epithelial-to-mesenchymal transition (EMT) characterized by TGFβ pathway activation and SNAIL expression was associated with the accumulation of CTCs. Finally, we observed that conditional silencing of SNAIL completely blocked CTC production and regional/distant metastasis. Using this unique bladder cancer xenograft model, we conclude that metastasis is dependent on a reversible EMT mediated by SNAIL.

PTTG1 regulated by miR-146a-3p promotes bladder cancer migration, invasion, metastasis and growth

Pituitary tumor-transforming gene 1 (PTTG1) is identified as an oncogene, and overexpresses in many tumors. However, the role of PTTG1 in bladder cancer (BC) hasn't yet been characterized well. In this study, we showed the expression of PTTG1 mRNA and protein were both significantly increased in BC tissues and cells. The PTTG1 protein levels were positive correlated with increased tumor size, tumor–node–metastasis (TNM) stage, lymphatic invasion and distant metastasis of BC. PTTG1 knockdown dramatically suppressed the migration, invasion, metastasis and growth, and induced senescence and cell-cycle arrest at G0/G1 phase of BC cells. We further identified PTTG1 was the direct target of miR-146a-3p through using target prediction algorithms and luciferase reporter assay. miR-146a-3p was low expressed and negatively correlated with PTTG1 levels in BC tissues and cells. miR-146a-3p overexpression inhibited migration, invasion, metastasis and growth, and induced senescence of BC cells. Rescue experiment suggested ectopic expression of miR-146a-3p and PTTG1 suppressed migration, invasion and induced cell cycle arrest and senescence of BC cells compared to PTTG1 overexpression, confirming miR-146a-3p inhibited BC progression by targeting PTTG1. In summary, our study found miR-146a-3p/PTTG1 axis regulated BC migration, invasion, metastasis and growth, and might be a targets for BC therapy.

Capsaicin triggers autophagic cell survival which drives epithelial mesenchymal transition and chemoresistance in bladder cancer cells in an Hedgehog-dependent manner

Bladder cancer (BC) is a common urologic tumor characterized by high risk of recurrence and mortality. Capsaicin (CPS), used as an intravesical drug for overactive bladder, was demonstrated to induce cell death in different cancer cells including BC cells.

Here we found that treatment of high-grade BC cells with high dose of CPS triggers autophagy. Infact, the CPS treatment alters the redox homeostasis by inducing production of radicals, mitochondrial depolarization, alterations of ADP/ATP ratio and activation of AMPK pathway stimulating the autophagic process in BC cells. The inhibition of autophagy, by using the specific inhibitor bafilomycin A or Beclin 1 knock-down, enhanced the CPS-induced cell death, demonstrating that CPS-induced autophagy acts as a pro-survival process in BC cells. By using PCR arrays and FACS analysis, we found that the CPS-treated BC cells displayed typical mesenchymal features of the epithelial mesenchymal transition (EMT) as elongated shape and over-expression of vimentin, α₅ and β₁ integrin subunits, integrin-like kinase and the anti-apoptotic Bcl-2 proteins. Moreover, we demonstrated that CPS treatment stimulates upregulation of Dhh/Ptch2/Zeb2 members of the Hedgehog signaling pathway, increases CD24, VEGFA and TIMP1 and decreases CD44 and ALCAM mRNA expression levels. By PTCH2 knock-down we found that the Hedgehog signaling pathway is involved in the CPS-induced autophagy and EMT phenotype.

Finally, we also showed that the CPS-resistant EMT-positive BC cells displayed an increased drug-resistance to the cytotoxic effects of mitomycin C, gemcitabine and doxorubicine drugs commonly used in BC therapy.

Cigarette smoke induced urocystic epithelial mesenchymal transition via MAPK pathways

Cigarette smoke has been shown to be a major risk factor for bladder cancer. Epithelial-mesenchymal transition (EMT) is a crucial process in cancer development. The role of MAPK pathways in regulating cigarette smoke-triggered urocystic EMT remains to be elucidated. Human normal urothelial cells and BALB/c mice were used as in vitro and in vivo cigarette smoke exposure models. Exposure of human normal urothelial cells to cigarette smoke induced morphological change, enhanced migratory and invasive capacities, reduced epithelial marker expression and increased mesenchymal marker expression, along with the activation of MAPK pathways. Moreover, we revealed that ERK1/2 and p38 inhibitors, but rather JNK inhibitor, effectively attenuated cigarette smoke-induced urocystic EMT. Importantly, the regulatory function of ERK1/2 and p38 pathways in cigarette smoke-triggered urocystic EMT was further confirmed in mice exposed to CS for 12 weeks. These findings could provide new insight into the molecular mechanisms of cigarette smoke-associated bladder cancer development as well as its potential intervention.

14, 15-EET induces breast cancer cell EMT and cisplatin resistance by up-regulating integrin αvβ3 and activating FAK/PI3K/AKT signaling

Background

14,15-epoxyeicosatrienoic acid (14,15-EET) is an important lipid signaling molecule involved in the regulation of tumor metastasis, however, the role and molecular mechanisms of 14,15-EET activity in breast cancer cell epithelial-mesenchymal transition (EMT) and drug resistance remain enigmatic.

Methods

The 14, 15-EET level in serum and in tumor or non-cancerous tissue from breast cancer patients was measured by ELISA. qRT-PCR and western blot analyses were used to examine expression of integrin αvβ3. The role of 14, 15-EET in breast cancer cell adhesion, invasion was explored by adhesion and Transwell assays. The role of 14, 15-EET in breast cancer cell cisplatin resistance in vitro was determined by MTT assay. Western blot was conducted to detect the protein expressions of EMT-related markers and FAK/PI3K/AKT signaling. Xenograft models in nude mice were established to explore the roles of 14, 15-EET in breast cancer cells EMT and cisplatin resistance in vivo.

Results

In the present study, we show that serum level of 14, 15-EET increases in breast cancer patients and 14, 15-EET level of tumor tissue is higher than that of non-cancerous tissue. Moreover, 14, 15-EET increases integrin αvβ3 expression, leading to FAK activation. 14, 15-EET induces breast cancer cell EMT via integrin αvβ3 and FAK/PI3K/AKT cascade activation in vitro. Furthermore, we find that 14, 15-EET induces breast cancer cells EMT and cisplatin resistance in vivo, αvβ3 integrin and the resulting FAK/PI3K/AKT signaling pathway are responsible for 14, 15-EET induced-breast cancer cells cisplatin resistance.

Conclusions

Our findings suggest that inhibition of 14, 15-EET or inactivation of integrin αvβ3/FAK/PI3K/AKT pathway could serve as a novel approach to reverse EMT and cisplatin resistance in breast cancer cells.

Focal adhesion molecule Kindlin-1 mediates activation of TGF-β signaling by interacting with TGF-βRI, SARA and Smad3 in colorectal cancer cells

Kindlin-1, an integrin-interacting protein, has been implicated in TGF-β/Smad3 signaling. However, the molecular mechanism underlying Kindlin-1 regulation of TGF-β/Smad3 signaling remains elusive. Here, we reported that Kindlin-1 is an important mediator of TGF-β/Smad3 signaling by showing that Kindlin-1 physically interacts with TGF-β receptor I (TβRI), Smad anchor for receptor activation (SARA) and Smad3. Kindlin-1 is required for the interaction of Smad3 with TβRI, Smad3 phosphorylation, nuclear translocation, and finally the activation of TGF-β/Smad3 signaling pathway. Functionally, Kindlin-1 promoted colorectal cancer (CRC) cell proliferation in vitro and tumor growth in vivo, and was also required for CRC cell migration and invasion via an epithelial to mesenchymal transition. Kindlin-1 was found to be increased with the CRC progression from stages I to IV. Importantly, raised expression level of Kindlin-1 correlates with poor outcome in CRC patients. Taken together, we demonstrated that Kindlin-1 promotes CRC progression by recruiting SARA and Smad3 to TβRI and thereby activates TGF-β/Smad3 signaling. Thus, Kindlin-1 is a novel regulator of TGF-β/Smad3 signaling and may also be a potential target for CRC therapeutics.

Positive Correlation between Matrix Metalloproteinases and Epithelial-to-Mesenchymal Transition and its Association with Clinical Outcome in Bladder Cancer Patients

Involvement of matrix metalloproteinases (MMPs) in the pathogenesis of urothelial carcinoma elects them to be sensitive marker for clinical and prognostic implications. MMPs regulate tumor growth and invasion by inducing epithelial-to-mesenchymal transition (EMT) which is characterized by the complex reprogramming of epithelial cells and ultimately bring about major changes in the structural organization of bladder urothelium. The present study has been undertaken to evaluate the clinical relevance of MMPs in two distinct types of bladder cancer disease. Expression analysis of MMPs namely MMP-2, MMP-7, MMP-9 and EMT markers including epithelial marker, E-cadherin; mesenchymal markers, N-cadherin and Vimentin; and EMT-activating transcriptional factors (EMT-ATFs), Snail, Slug, Twist and Zeb was done in 64 cases of bladder tumor tissues [{Non-muscle invasive bladder cancer (NMIBC): 35 cases} and {Muscle invasive bladder cancer (MIBC): 29 cases}] by real-time quantitative polymerase chain reaction (RT-qPCR). Immunohistochemistry (IHC) staining was done in matched bladder tumor tissues to evaluate the protein expression and localization of E-cadherin, N-cadherin, Vimentin, Snail, and Slug. Our data showed overexpression of MMP-2, MMP-7 and MMP-9 at transcriptome level in 32.8%, 25% and 37.5% bladder tumor cases respectively. These tumor tissues were examined for higher expression of mesenchymal markers (N-cadherin and Vimentin) at mRNA and protein level and exhibited statistical association with tumor stage and tumor grade (p = 0.02, p = 0.04, Mann-Whitney test). Significant statistical correlation in tumor tissues with overexpressed MMPs has also been observed between gain of transcriptional factors and weak expression of E-cadherin with tumor stage, grade, gender, presence of hematuria and smoking history of the patients. Gene expression patterns of EMT markers in bladder tumors with overexpressed MMPs and their significant association with clinical profile validate the important role of MMPs in the pathogenesis of urothelial carcinoma of bladder (UCB). Increased expression of specific MMPs may affect several downstream EMT programs and thus may improve its diagnostic and prognostic utility in clinical setting.

Distinct mechanisms contribute to acquired cisplatin resistance of urothelial carcinoma cells

Cisplatin (CisPt) is frequently used in the therapy of urothelial carcinoma (UC). Its therapeutic efficacy is limited by inherent or acquired drug resistance. Here, we comparatively investigated the CisPt-induced response of two different parental urothelial carcinoma cell lines (RT-112, J-82) with that of respective drug resistant variants (RT-112^R, J-82^R) obtained upon month-long CisPt selection. Parental RT-112 cells were ~2.5 fold more resistant to CisPt than J-82 cells and showed a different expression pattern of CisPt-related resistance factors. CisPt resistant RT-112^R and J-82^R variants revealed a 2–3-fold increased CisPt resistance as compared to their corresponding parental counterparts. Acquired CisPt resistance was accompanied by morphological alterations resembling epithelial mesenchymal transition (EMT). RT-112^R cells revealed lower apoptotic frequency and more pronounced G2/M arrest following CisPt exposure than RT-112 cells, whereas no differences in death induction were observed between J-82 and J-82^R cells. CisPt resistant J-82^R cells however were characterized by a reduced formation of CisPt-induced DNA damage and related DNA damage response (DDR) as compared to J-82 cells. Such difference was not observed between RT-112^R and RT-112 cells. J-82^R cells showed an enhanced sensitivity to pharmacological inhibition of checkpoint kinase 1 (Chk1) and, moreover, could be re-sensitized to CisPt upon Chk1 inhibition. Based on the data we suggest that mechanisms of acquired CisPt resistance of individual UC cells are substantially different, with apoptosis- and DDR-related mechanisms being of particular relevance. Moreover, the findings indicate that targeting of Chk1 might be useful to overcome acquired CisPt resistance of certain subtypes of UC.

The silencing of LncRNA-H19 decreases chemoresistance of human glioma cells to temozolomide by suppressing epithelial-mesenchymal transition via the Wnt/β-Catenin pathway

Introduction

Temozolomide (TMZ) is commonly used for glioma chemotherapy. However, TMZ resistance limits the therapeutic effect of TMZ in glioma treatment. LncRNA-H19 acts as an oncogenic LncRNA in some types of cancers and has been reported to be up-regulated in glioma.

Materials and methods

In our present study, we established TMZ-resistant glioma cells (U-251TMZ and M059JTMZ) to explore the effect of H19 on the chemoresistance of glioma cells.

Results

We observed that the expression of H19 was significantly increased in U-251TMZ and M059JTMZ cells. Knockdown of H19 expression using specific shRNA in U-251TMZ and M059JTMZ led to decreased half maximal inhibitory concentration (IC₅₀) values for TMZ and increased cell apoptosis rates, indicating that the silencing of H19 decreased chemoresistance of glioma cells to TMZ. In addition, silencing of H19 suppressed epithelial-mesenchymal transition (EMT) by increasing the expression of epithelial marker E-cadherin and decreasing the expression of mesenchymal marker Vimentin and ZEB1. Moreover, inducing EMT by TGF-β1 treatment led to increased IC₅₀ values for TMZ and decreased cell apoptosis rates compared with TMZ+H19 shRNA group, suggesting that the induction of EMT counteracted the inhibitory effect of H19 shRNA on chemoresistance of glioma cells to TMZ. Furthermore, the reduced expression of H19 down-regulated the expression of β-Catenin and its downstream targets c-myc and Survivin in TMZ-treated glioma cells. Activation of Wnt/β-Catenin pathway by Licl treatment promoted EMT and enhanced chemoresistance to TMZ compared with TMZ+H19 shRNA group.

Conclusion

Taken together, our data suggest that H19 decreased chemoresistance of glioma cells to TMZ by suppressing EMT via the inhibition of Wnt/β-Catenin pathway. Our study might represent a novel therapeutic target for TMZ-resistant glioma.

MiR-429 reverses epithelial-mesenchymal transition by restoring E-cadherin expression in bladder cancer

Epithelial-mesenchymal transition (EMT) accompanying loss of E-cadherin is important for invasiveness and metastasis of bladder cancer. MicroRNAs (miRs) had been associated with cancer progression and differentiation in several cancers. Our goal is to find out the specific miR which modulates EMT in bladder cancer. Real-time quantitative polymerase chain reaction was used to measure the miRs expression in urothelial cell carcinoma (UCC) cell lines. MiR or siRNA mimics was used to regulate miR and mRNA level respectively. Migration and scratch assays were used to determine the migratory ability. Zymography assay was used to confirm the metalloproteinase activity. Western blotting was used to elucidate the mechanism which regulated by specific miR. MiR-429 was highly expressed in low grade UCC cell lines. Exogenous mimic of miR-429 treatment dramatically inhibited the migratory ability of T24 cells. MiR-429 downstream target ZEB1 was decreased, E-cadherin was restored, and β-catenin was contrarily decreased by exogenous mimic of miR-429 treatment in T24 cells. Cell invasive ability was also inhibited by exogenous mimic of miR-429 treatment through inactivating the MMP-2 activity in T24 cells. E-cadherin protein expression level was inhibited by E-cadherin siRNA accompanied with increasing cell migratory ability when compared with control group in low grade TSGH8301 cells. MiR-429 decreased the cell migratory and invasive abilities through reducing ZEB1 and β-catenin, restoring the E-cadherin expression and inactivation of MMP-2 of UCC cells. MiR-429 might be used as a progression marker of bladder cancer.

PomGnT1 enhances temozolomide resistance by activating epithelial-mesenchymal transition signaling in glioblastoma

Temozolomide (TMZ) is commonly used in glioblastoma (GBM) chemotherapy. However, a great challenge for TMZ treatment is the rapid development of resistance and subsequent tumor recurrence and poor outcome. In the present study we established TMZ-resistant GBM cells (U87-TR and U251-TR) and found that the expression of PomGnT1 was significantly upregulated in TMZ-resistant GBM cells compared with the TMZ-sensitive counterparts. Furthermore, overexpression of PomGnT1 in U87-MG and U251-MG cells led to increased IC50 values for TMZ and reduced apoptosis of cells. Knockdown of PomGnT1 in both U87-TR and U251-TR cells led to decreased IC50 values for TMZ and enhanced apoptosis. Biochemical analysis revealed that PomGnT1 regulates the expression of factors in epithelial-mesenchymal transition signaling including TCF8, vimentin, β-catenin and Slug in GBM cells. These findings demonstrate that PomGnT1 might be a new focus of GBM research for treatment of recurrent TMZ-resistant GBM.

Promoter hypermethylation of LGALS4 correlates with poor prognosis in patients with urothelial carcinoma

Galectine-4 (gal-4), encoded by the LGALS4 gene, was recently shown to exhibit a tumor suppressive effect in colorectal carcinoma and pancreatic adenocarcinoma, although how the expression of this gene is regulated remains unknown. No reports describe the significance of gal-4 in the malignant potential of urothelial tumors. Thus, we analyzed LGALS4 methylation and gene expression and their clinical relevance and biological function in urothelial carcinoma (UC). LGALS4 methylation was initially identified as a progression biomarker for UC patients through genome-wide DNA methylation profiling of 16 tumor samples. Bisulfite sequencing PCR and immunohistochemistry were performed to validate the promoter methylation and expression of LGALS4. We used quantitative methylation-specific PCR to determine the methylation levels of LGALS4 normalized to ACTB in the tumor samples of 79 UC patients and compared the levels between patients with different clinicopathological characteristics. The association with survival probability was analyzed with the Kaplan-Meier method and Cox regression analysis. The ectopic expression of gal-4 in cancer cell lines was used to address its biological function in UC in vitro. The promoter hypermethylation of LGALS4 (>2.51, log₁₀ scale) revealed a positive correlation with high levels of both histological grade and tumor T category and with lymph node metastasis (all P≤0.001). In addition, LGALS4 hypermethylation was an independent predictor of inferior survival in UC patients (P<0.05). The ectopic expression studies demonstrated that gal-4 suppressed urothelial cancer cell growth, migration, and invasion. Thus, LGALS4 may function as a tumor suppressor gene in UC progression. Our findings provide evidence that methylation-mediated LGALS4 gene repression may be involved in urothelial tumor progression.

The M6A methyltransferase METTL3: acting as a tumor suppressor in renal cell carcinoma

We aimed to study the role of METTL3 in renal cell carcinoma (RCC) carcinogenesis and development. Immunohistochemistry was performed in clinical tissue microarray. Expression level of METTL3 in RCC tissues and cell lines was evaluated by quantitative real-time PCR (qRT-PCR) and western blot. Then, the effects of METTL3 on proliferation, migration, invasion and cell cycle were studied in RCC cells. Additionally, in vivo study was carried out in nude mice. Negative METTL3 expression was associated with larger tumor size (P=0.010) and higher histological grade (P=0.021). Moreover, RCC patients with positive METTL3 expression had an obvious longer survival time (P=0.039). METTL3 mRNA and protein expression was lower in RCC samples compared with adjacent non-tumor samples, and lower in RCC cell lines (CAKI-1, CAKI-2 and ACHN) compared with HK-2. Afterwards, knockdown of METTL3 could obviously promote cell proliferation, migration and invasion function, and induce G0/G1 arrest. In contrast, up-regulation of METTL3 could inhibit such functions and reduce G0/G1 arrest. Additionally, up-regulation of METTL3 significantly suppressed tumor growth in vivo. Furthermore, significant changes in epithelial-to-mesenchymal transition (EMT) and PI3K-Akt-mTOR pathways were observed. Overall, our findings demonstrated that METTL3 might have a carcinostasis role in cell proliferation, migration, invasion function and cell cycle of RCC, indicating METTL3 may act as a novel marker for tumorigenesis, development and survival of RCC.

Enhancing E-cadherin expression via promoter-targeted miR-373 suppresses bladder cancer cells growth and metastasis

Previous studies showed that miR-373 had the capacity to induce tumor suppressor gene E-cadherin expression in prostate cancer cells. However, whether miR-373 can activate the expression of E-cadherin in human bladder cancer (BCa) cells and inhibit cells remains to be elucidated. Here, we found that both miR-373 and E-cadherin were low expressed in BCa tissues and cell lines, and significantly correlated with tumor stage, grade, and lymph node metastasis. In addition, decreased E-cadherin expression or low expression of both miR-373 and E-cadherin is associated with poor overall survival in patients with BCa. Transfection of miR-373 into BCa cells readily activated E-cadherin expression by targeting promoter. Moreover, miR-373 exhibited robust capacity to inhibit cells proliferation, suppress migration and invasion by enhancing E-cadherin expression, and significantly suppress the growth of xenografts and metastasis in nude mice. Altogether, our findings indicate that miR-373 may as a tumor suppressor in BCa by activating E-cadherin expression.

T-cell immunoglobulin mucin-3 as a potential inducer of the epithelial-mesenchymal transition in hepatocellular carcinoma

T-cell immunoglobulin mucin (TIM)-3 is an important member of the TIM gene family, which was thought to contribute to the progression of numerous types of cancer, including hepatocellular carcinoma (HCC); however, the mechanism underlying TIM-3 functions in HCC progression has not yet been extensively investigated. The present study aimed to investigate the function of TIM-3 in the metastasis of HCC and to determine whether the alteration of TIM-3 expression levels regulated the epithelial-mesenchymal transition (EMT) occurrence of HCC, using epithelial (E)-cadherin, neuronal (N)-cadherin, matrix metallopeptidase-9 (MMP-9), Twist 1, Slug, Snail, and Smad as EMT biomarkers. The results demonstrated that upregulation of TIM-3 using TIM-3 lentiviral activation particles (5 µl) increased cell migration and invasion, which was decreased in TIM-3 short interfering RNA-infected cells (10 µM, 3 µl) correspondingly. SMMC-7721 HCC cells were used as the control. EMT was aggravated in TIM-3 upregulated SMMC-7721 cells, which was attenuated in the TIM-3 interference group, accompanied by an alteration of E-cadherin, N-cadherin, MMP-9, Twist 1, Slug, Snail and Smad expression levels. The data presented suggests that TIM-3 serves an essential role in the metastasis of HCC, the mechanism of which was associated with EMT occurrence. Interference of TIM-3 is expected to be an effective means to prevent and control EMT, and further the metastasis of HCC.

TGF-β Stimulation of EMT Programs Elicits Non-genomic ER-α Activity and Anti-estrogen Resistance in Breast Cancer Cells

AIM

Estrogen receptor-α (ER-α) activation drives the progression of luminal breast cancers. Signaling by transforming growth factor-β (TGF-β) typically opposes the actions of ER-α; it also induces epithelial-mesenchymal transition (EMT) programs that promote breast cancer dissemination, stemness, and chemoresistance. The impact of EMT programs on nongenomic ER-α signaling remains unknown and was studied herein.

METHODS

MCF-7 and BT474 cells were stimulated with TGF-β to induce EMT programs, at which point ER-α expression, localization, and nongenomic interactions with receptor tyrosine kinases and MAP kinases (MAPKs) were determined. Cell sensitivity to anti-estrogens both before and after traversing the EMT program was also investigated.

RESULTS

TGF-β stimulated MCF-7 and BT474 cells to acquire EMT phenotypes, which enhanced cytoplasmic accumulation of ER-α without altering its expression. Post-EMT cells exhibited (i) elevated expression of EGFR and IGF1R, which together with Src formed cytoplasmic complexes with ER-α; (ii) enhanced coupling of EGF, IGF-1 and estrogen to the activation of MAPKs; and (iii) reduced sensitivity to tamoxifen, an event reversed by administration of small molecule inhibitors against the receptors for TGF-β, EGF, and IGF-1, as well as those against MAPKs.

CONCLUSION

EMT stimulated by TGF-β promotes anti-estrogen resistance by activating EGFR-, IGF1R-, and MAPK-dependent nongenomic ER-α signaling.

Honokiol inhibits bladder cancer cell invasion through repressing SRC-3 expression and epithelial-mesenchymal transition

Urinary bladder cancer (UBC) is one of the most common urological cancer types. Muscle invasive bladder cancer possesses high propensity for metastasis with poor prognosis. Honokiol is a lignan isolated from Magnolia officinalis with high bioavailability and potent anticancer effects. The results of the present study demonstrated that honokiol significantly inhibited UBC cell migration and invasion in a dose-dependent manner compared with the vehicle-treated control group. In addition, honokiol treatment suppressed epithelial-mesenchymal transition by induction of E-cadherin and repression of N-cadherin. Honokiol was capable of significantly downregulating the expression of cell invasion-associated genes, steroid receptor coactivator-3 (SRC-3), matrix metalloproteinase (MMP)-2 and Twist1. Notably, the inhibition of UBC cell invasion by honokiol was reversed by reintroduction of oncoprotein SRC-3 expression, with the restoration of MMP-2 and Twist1, and reduction of E-cadherin expression. Furthermore, the results of the luciferase assay confirmed that SRC-3 could regulate Twist1 promoter activity. Taken together, the results of the present study suggest that honokiol is a promising agent against UBC cell invasion via downregulation of SRC-3 and its target genes.

Long non-coding RNA CCAT1 promotes metastasis and poor prognosis in epithelial ovarian cancer

In this study, we reported that long non-coding RNA (lncRNA) CCAT1 was upregulated in epithelial ovarian cancer (EOC) tissues, and was associated with FIGO stage, histological grade, lymph node metastasis and poor survival of EOC patients. Multivariate Cox regression analysis showed that CCAT1 was an independent prognostic indicator. While CCAT1 downregulation inhibited EOC cell epithelial-mesenchymal transition (EMT), migration and invasion, CCAT1 upregulation promoted EOC cell EMT, migration and invasion. We further identified and confirmed that miR-152 and miR-130b were the targets of CCAT1, and CCAT1 functioned by targeting miR-152 and miR-130b. Subsequently, ADAM17 and WNT1, and STAT3 and ZEB1 were confirmed to be the targets of miR-152 and miR-130b, respectively, and could be regulated by CCAT1 in EOC cells. Knockdown of anyone of these four proteins inhibited EOC cell EMT, migration and invasion. Taken together, our study first revealed a critical role of CCAT1-miR-152/miR-130b-ADAM17/WNT1/STAT3/ZEB1 regulatory network in EOC cell metastasis. These findings provide great insights into EOC initiation and progression, and novel potential therapeutic targets and biomarkers for diagnosis and prognosis for EOC.

hsa-miR-485-5p reverses epithelial to mesenchymal transition and promotes cisplatin-induced cell death by targeting PAK1 in oral tongue squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is currently a highly prevalent disease worldwide. Cisplatin (CDDP) is widely used for the chemotherapy of OSCC. Yet, the molecular mechanisms responsible for cisplatin resistance have not been fully elucidated. In this study, we showed that overexpression of p21 (RAC1) activated kinase 1 (PAK1) induced epithelial to mesenchymal transition (EMT) and significantly promoted the invasion and migration of oral squamous cell carcinoma SCC25 cells. Emerging evidence indicates a strong link between resistance to therapy and the induction of EMT in cancer. We showed that overexpression of PAK1 induced cisplatin resistance in SCC25 cells. ERCC1 and YAP can promote cisplatin resistance in human OSCC. We showed that ERCC1 and YAP protein were upregulated by PAK1 in SCC25 cells. We found that miR-485-5p inhibited PAK1 protein expression in the SCC25 cells. Contrary to PAK1, we demonstrated that overexpression of miR-485-5p reversed EMT and significantly inhibited invasion and migration. Moreover, its overexpression sensitized SCC25-CR cells (cisplatin-resistant cells) to cisplatin. Thus, we conclude that miR-485-5p reverses EMT and promotes cisplatin-induced cell death by targeting PAK1 in oral tongue squamous cell carcinoma. This study suggests that PAK1 plays an essential role in the progression of OSCC and it is a potential therapeutic target for OSCC.

Relationships of MMP-9, E-cadherin, and VEGF expression with clinicopathological features and response to chemosensitivity in gastric cancer

The matrix metalloproteinase-9, E-cadherin, and vascular endothelial growth factor play an important role in behavior of tumor cell growth, invasion, and metastasis. In this study, we investigated the relationships of matrix metalloproteinase-9, E-cadherin, and vascular endothelial growth factor expression with clinicopathological features and results of chemosensitivity tested by collagen gel droplet–embedded culture–drug sensitivity test in gastric cancer. Fresh specimens were used for collagen gel droplet–embedded culture–drug sensitivity test and paired fixed specimens were used for immunohistochemistry. Positive expression of matrix metalloproteinase-9 was associated with poorly differentiated carcinoma (p = 0.032), lymph node metastasis (p = 0.022), and tumor stage (p = 0.023). Negative expression of E-cadherin was associated with poorly differentiated carcinoma (p = 0.007), lymph node metastasis (p = 0.012), and tumor stage (p = 0.007). Positive expression of vascular endothelial growth factor was associated with tumor size (p = 0.040) and stage (p = 0.007). Collagen gel droplet–embedded culture–drug sensitivity test was successfully evaluated in 56 patients. Among them, 29 (51.7%) patients were resistant to TS-1 and 31 (55.3%) patients were resistant to L-OHP. The L-OHP resistance rate in vascular endothelial growth factor positive patients was significantly higher than that in negative patients (p = 0.031). The L-OHP resistance rate in E-cadherin negative patients was significantly higher than that in positive patients (p = 0.014). In conclusion, matrix metalloproteinase-9, E-cadherin, and vascular endothelial growth factor were involved in tumor invasion and metastasis. Positive expression of matrix metalloproteinase-9 and vascular endothelial growth factor and negative expression of E-cadherin were malignant markers for gastric cancer. Positive expression of vascular endothelial growth factor and negative expression of E-cadherin were associated with L-OHP resistance.

Epithelial-mesenchymal transition promotes SOX2 and NANOG expression in bladder cancer

Bladder cancer is the most common malignant tumor of the urothelium and is classified into non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Stemness markers such as SOX2 and NANOG are frequently overexpressed in various aggressive cancers, including MIBC; epithelial-mesenchymal transition (EMT) has been proposed as a potential trigger of stemness in cancers. To determine whether cancer stemness is acquired via EMT in bladder cancer, we studied the effect of EMT on the expression of SOX2 and NANOG in bladder cancer cell lines. We also analyzed their expression in clinical tissue samples. Our results revealed that a potent EMT inducer (transforming growth factor β1) reduced the expression of the epithelial marker E-cadherin and increased expression of both SOX2 and NANOG in epithelial-type bladder cancer cells. As for clinical bladder cancer samples, in NMIBC, E-cadherin expression was slightly diminished, and the expression of both SOX2 and NANOG was negligible. In contrast, in MIBC, E-cadherin expression was highly and heterogeneously diminished, while the expression of both SOX2 and NANOG was increased. We also noticed that either E-cadherin or SOX2 (or NANOG) was expressed (ie, in a manner exclusive of each other). In addition, the concentration of E-cadherin showed a significant negative correlation with tumor grade and stage, while expression of SOX2 and NANOG positively correlated with those clinicopathological parameters. These findings suggest that EMT promotes stemness of bladder cancer cells, contributing to tumor aggressiveness. This EMT-cancer stemness axis may also play an important role in the pathogenesis of NMIBC and MIBC.Laboratory Investigation advance online publication, 27 February 2017; doi:10.1038/labinvest.2017.17.

miR-495 promotes the chemoresistance of SCLC through the epithelial-mesenchymal transition via Etk/BMX

miR-495 serves as an oncogenic miRNA or a tumor suppressor in different types of cancer. However, its role in the drug resistance of small cell lung cancer (SCLC) remains unidentified. In this study, we investigated whether miR-495 regulates the chemoresistance of SCLC through the epithelial-mesenchymal transition (EMT) via Epithelial and endothelial tyrosine kinase (Etk/BMX) using two drug-resistant cell lines. Loss- and gain-of-function experiments showed miR-495 regulated cell proliferation, tumor growth and drug resistance. miR-495 suppression or Etk/BMX elevation in SCLC specimens was correlated with poor pathologic stage and survival time. Etk/BMX was one of the directly targeted genes of miR-495. Ectopic expression of Etk/BMX obviously rescued the miR-495 elevation elevation-induced inhibition of drug resistance. Etk/BMX over-expression led to higher levels of EMT mesenchymal factors (Zeb-2, Twist, Vim) and lower levels of the epithelial molecule β-catenin, while suppression of Etk/BMX showed the opposite trend. Knockdown of Zeb-2 and Twist inhibited the chemoresistance of cells. Our study revealed that miR-495 promoted the chemoresistance of SCLC through the epithelial-mesenchymal transition via Etk/BMX. miR-495 re-expression or Etk/BMX depletion is a promising strategy for interfering with chemoresistance in SCLC.

Simultaneous Targeting of Bladder Tumor Growth, Survival, and Epithelial-to-Mesenchymal Transition with a Novel Therapeutic Combination of Acetazolamide (AZ) and Sulforaphane (SFN)

BACKGROUND

Current chemotherapies for advanced stage metastatic bladder cancer often result in severe side effects, and most patients become drug resistant over time. Thus, there is a need for more effective therapies with minimal side effects.

OBJECTIVE

The acid/base balance in tumor cells is essential for tumor cell functioning. We reasoned that simultaneous targeting of pH homeostasis and survival pathways would improve therapeutic efficacy. We evaluated the effectiveness of targeting pH homeostasis with the carbonic anhydrase inhibitor acetazolamide (AZ) in combination with the survival pathway targeting isothiocyanate sulforaphane (SFN) on the HTB-9 and RT112(H) human bladder tumor cell lines.

MATERIALS AND METHODS

We assessed viability, proliferation, and survival in vitro and effect on xenografts in vivo.

RESULTS

Combination AZ + SFN treatment induced dose-dependent suppression of growth, produced a potent anti-proliferative and anti-clonogenic effect, and induced apoptosis through caspase-3 and PARP activation. The anti-proliferative effect was corroborated by significant reductions in Ki-67, pHH3, cyclin D1, and sustained induction of the cell cycle inhibitors, p21 and p27. Both active p-Akt (Ser473) and p-S6 were significantly downregulated in the AZ + SFN combination treated cells with a concomitant inhibition of Akt kinase activity. The inhibitory effects of the AZ + SFN combination treatment showed similar efficacy as the dual PI3K/mTOR pathway inhibitor NVP-BEZ235, albeit at an expected higher dose. In terms of the effect on the metastatic potential of these bladder cancers, we found downregulated expression of carbonic anhydrase 9 (CA9) concomitant with reductions in both E-cadherin, N-cadherin, and vimentin proteins mitigating the epithelial-to-mesenchymal transition (EMT), suggesting negation of this program.

CONCLUSION

We suggest that reductions in these components could be linked with downregulation of the survival mediated Akt pathway and suggested an active role of the Akt pathway in bladder cancer. Altogether, our in vitro and pre-clinical model data support the potential use of an AZ + SFN combination for the treatment of bladder cancer.

LGR5 Is a Gastric Cancer Stem Cell Marker Associated with Stemness and the EMT Signature Genes NANOG, NANOGP8, PRRX1, TWIST1, and BMI1

Background

Accumulating evidence supports the hypothesis that cancer stem cells (CSCs) are essential for cancer initiation, metastasis and drug resistance. However, the functional association of gastric CSC markers with stemness and epithelial-mesenchymal transition (EMT) signature genes is unclear.

Methods

qPCR was performed to measure the expression profiles of stemness and EMT signature genes and their association with putative CSC markers in gastric cancer tissues, cancer cell lines and sphere cells. Western blot analysis was used to confirm the results of the transcript analysis. Cell proliferation, cell migration, drug resistance and sphere cell growth assays were conducted to measure the expansion and invasion abilities of the cells. Tumor xenograft experiments were performed in NOD/SCID mice to test cell stemness in vivo. Flow cytometry and immunofluorescence staining were used to analyze cell subpopulations.

Results

The expression of LGR5 was strikingly up-regulated in sphere cells but not in cancer tissues or parental adherent cells. The up-regulation of LGR5 was also positively associated with stemness regulators (NANOG, OCT4, SOX2, and AICDA) and EMT inducers (PRRX1, TWIST1, and BMI1). In addition, sphere cells exhibited up-regulated vimentin and down-regulated E-cadherin expression. Using gene-specific primers, we found that the NANOG expression primarily originates from the retrogene NANOGP8. Western blot analysis showed that the expression of both LGR5 and NANOG is significantly higher in sphere cells. LGR5 over-expression significantly enhanced sphere cell growth, cell proliferation, cell migration and drug resistance in MGC803 cells. Tumor xenografts in nude mice showed that sphere cells are at least 10 times more efficient at tumor initiation than adherent cells. Flow cytometry analysis showed that ~20% of sphere cells are LGR5+/CD54+, but only ~3% of adherent cells are Lgr5+/CD54+. Immunofluorescence staining supports the above results.

Conclusion

The LGR5-expressing fraction of CD54+ cells represents gastric cancer CSCs, in which LGR5 is closely associated with stemness and EMT core genes, and NANOG expression is mainly contributed by the retrogene NANOGP8. Sphere cells are the best starting materials for the characterization of CSCs.