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

Luteolin suppresses the metastasis of triple-negative breast cancer by reversing epithelial-to-mesenchymal transition via downregulation of β-catenin expression

The metastasis of breast cancer is associated with dismal prognosis and high mortality due to the lack of effective treatment. Luteolin, a natural flavonoid compound, has been shown to exert antitumor activity in various types of cancers. However, the effects and mechanisms of luteolin on the metastasis of triple-negative breast cancer (TNBC) remain elusive. In the present study, we found that pretreatment of highly metastatic TNBC cell lines with luteolin dose‑dependently inhibited cell migration and invasion, and reversed epithelial-mesenchymal transition (EMT) as determined by altered morphological characteristics, downregulated epithelial markers and upregulated mesenchymal markers, and inhibited EMT-related transcription factors. In an in vivo metastasis experiment using a xenograft model, luteolin markedly inhibited lung metastases of breast cancer and the expression of EMT molecules vimentin and Slug in primary tumor tissues. Notably, luteolin also suppressed the expression of β-catenin mRNA and protein in vitro and in vivo. Furthermore, overexpression of β-catenin by adenoviruses blocked these benefits of luteolin on invasion and metastases of breast cancer. In conclusion, all these results indicated that luteolin effectively suppressed metastases of breast cancer by reversing EMT, which may be mediated by downregulation of β-catenin.

ERK-mediated NF-κB activation through ASIC1 in response to acidosis

Acidic microenvironment is a common feature of solid tumors. We have previously shown that neuron specific acid-sensing ion channel 1 (ASIC1) is expressed in breast cancer, and it is responsible for acidosis-induced cellular signaling through AKT, leading to nuclear factor-κB (NF-κB) activation, and cell invasion and metastasis. However, AKT is frequently activated in cancer. Thus, a key question is whether ASIC1-mediated cell signaling still takes place in the cancer cells carrying constitutively active AKT. In the present study, we show that among four prostate cancer cell lines tested, 22Rv1 cells express the highest level of phosphorylated AKT that is not impacted by acidosis. However, acidosis can still induce NF-κB activation during which extracellular signal-regulated kinase (ERK) serves as an alternative pathway for ASIC-mediated cell signaling. Inhibition of ERK by chemical inhibitors or small interfering RNAs suppresses the acidosis-induced NF-κB activity through regulation of the inhibitory subunit IκBα phosphorylation. Furthermore, suppression of ASIC1-mediated generation of reactive oxygen species (ROS) by ROS scavengers, such as glutathione or N-acetyl-cysteine causes a decrease in ERK phosphorylation and degradation of IκBα. Finally, ASIC1 is upregulated in a subset of prostate cancer cases and ASIC1 knockout by CRISPR/Cas9 significantly suppresses cell invasion, and castration resistance both in vitro and in vivo. Together, these results support the significance of ASIC1-ROS-ERK-IκBα-NF-κB axis in prostate tumorigenesis, especially in the constitutively active AKT background.

Acquired platinum resistance involves epithelial to mesenchymal transition through ubiquitin ligase FBXO32 dysregulation

To identify the molecules involved in epithelial to mesenchymal transition (EMT) in urothelial carcinoma (UC) after acquisition of platinum resistance, here we examined the changes in global gene expression before and after platinum treatment. Four invasive UC cell lines, T24, 5637, and their corresponding sublines T24PR and 5637PR with acquired platinum resistance, were assessed by microarray, and the ubiquitin E3 ligase FBXO32 was newly identified as a negative regulator of EMT in UC tumors after acquisition of platinum resistance. In vitro and in vivo studies showed an intimate relationship between FBXO32 expression and EMT, demonstrating that FBXO32 dysregulation in T24PR cells results in elevated expression of the mesenchymal molecules SNAIL and vimentin and decreased expression of the epithelial molecule E-cadherin. The association between FBXO32 expression and EMT was further validated using clinical samples. Knockdown of MyoD expression, a specific target of FBXO32 polyubiquitination, revealed upregulation of E-cadherin expression and downregulation of SNAIL and vimentin expression in T24PR cells. Comparative genomic hybridization array analysis demonstrated loss of heterozygosity at 8q24.13 in T24PR cells, which harbors FBXO32. Our findings suggest the importance of the association between EMT and ubiquitin-proteasome regulation when tumors develop acquired platinum resistance.

Expression of epidermal growth factor-like domain 7 may be a predictive marker of the effect of neoadjuvant chemotherapy for locally advanced uterine cervical cancer

Neoadjuvant chemotherapy (NAC) followed by hysterectomy may be effective for the treatment of locally advanced uterine cervical cancer and improve patient prognosis. It is important to identify markers that are able to predict whether NAC may be successful. Epidermal growth factor-like domain 7 (EGFL7) regulates vascular sprouting in blood vessel formation. In numerous types of human cancer, EGFL7 is upregulated and inhibits endothelial cell adhesion molecules, decreasing vascular tightness and, thus, increasing vascular permeability. It is considered that the overexpression of EGFL7 is able to inhibit drug delivery, resistance to apoptosis and the epithelial-to-mesenchymal transition. In the current study, 63 patients with locally advanced uterine cervical cancer were reviewed and classified as stage IIIA-IIIB using the International Federation of Gynecology and Obstetrics criteria. These patients (aged <70 years) were treated at Osaka City University Medical School Hospital, Japan, between 1995 and 2010. Tumor tissue samples were obtained by biopsy prior to NAC. The tissue samples were classified as group 1 or 2 depending on the efficacy of NAC. Surgery and radiotherapy were administered in group 1 (n=36), for which NAC was effective. In the patients of group 2 NAC was not effective, and radiotherapy alone was administered (n=27). The expression of EGFL7 and Snail was examined in paraffin-embedded tissue sample sections using the avidin-biotin peroxidase complex method. The results indicated that EGFL7 expression levels were significantly higher in group 2, as compared with group 1 (P<0.001). A similar result was observed for the expression levels of Snail (P=0.001). Group 1 exhibited significantly longer overall survival times compared with group 2 (P=0.001). The patients were also classified into a low EGFL7 expression level group (weighted score of ≤6) and a high EGFL7 expression level group (weighted score of ≥8). NAC was observed to be significantly more effective in the low EGFL7 expression level group (P<0.001), as compared with the high expression level group. The results suggest that the expression levels of EGFL7 may be a potential predictive marker of the efficacy of NAC for the treatment of locally advanced uterine cervical cancer.

miR-144-3p serves as a tumor suppressor for renal cell carcinoma and inhibits its invasion and metastasis by targeting MAP3K8

MicroRNAs (miRNAs) are important regulators involved in various cancers, including renal cell carcinoma (RCC). The role of the miRNAs involved in RCC progress and metastasis is largely unknown. Here, miRNA microarray analysis was performed to screen the significant miRNAs involved in RCC progress, and miR-144-3p was chosen for further study. We found that the expression of miR-144-3p was significantly lower in RCC specimens and cell lines. In addition, low expression level of miR-144-3p is correlated with tumor progression and poor survival in RCC patients. Based on in vitro assays, we found that miR-144-3p significantly inhibit cancer cell proliferation and progression. Furthermore, function studies revealed that miR-144-3p was significantly correlated with the metastasis potential by affecting the epithelial-mesenchymal transition (EMT). Moreover, Mitogen-activated protein kinase 8 (MAP3K8) is direct target of miR-144-3p, while the expression levels of MAP3K8 were inversely correlated with the expression levels of miR-144-3p in RCC tissues. Overall, our findings demonstrate that miR-144-3p targeted the MAP3K8 pathway to reduce tumor cells proliferation and metastasis in RCC, suggesting that this axis may provide a novel therapeutic target for RCC therapy.

Intrinsic subtypes and bladder cancer metastasis

Recent studies demonstrated that bladder cancers can be grouped into basal and luminal molecular subtypes that possess distinct biological and clinical characteristics. Basal bladder cancers express biomarkers characteristic of cancer stem cells and epithelial-to-mesenchymal transition (EMT). Patients with basal cancers tend have more advanced stage and metastatic disease at presentation. In preclinical models basal human orthotopic xenografts are also more metastatic than luminal xenografts are, and they metastasize via an EMT-dependent mechanism. However, preclinical and clinical data suggest that basal cancers are also more sensitive to neoadjuvant chemotherapy (NAC), such that most patients with basal cancers who are aggressively managed with NAC have excellent outcomes. Importantly, luminal bladder cancers can also progress to become invasive and metastatic, but they appear to do so via mechanisms that are much less dependent on EMT and may involve help from stromal cells, particularly cancer-associated fibroblasts (CAFs). Although patients with luminal cancers do not appear to derive much clinical benefit from NAC, the luminal tumors that are infiltrated with stromal cells appear to be sensitive to anti-PDL1 antibodies and possibly other immune checkpoint inhibitors. Therefore, neoadjuvant and/or adjuvant immunotherapy may be the most effective approach in treating patients with advanced or metastatic infiltrated luminal bladder cancers.

Understanding the biology of urothelial cancer metastasis

Management of unresectable urothelial cancer (UC) has been a clinical challenge for decades. While drug resistance is a key issue, precise understanding of biology of UC metastasis is another challenge for the improvement of treatment outcome of UC patients. Introduction of the cell biology concepts including epithelial-mesenchymal transition (EMT) and cancer stemness seems to explain UC metastasis. Molecular genetics based on gene expression profiling, next generation sequencing, and explosion of non-coding RNA world has opened the door to intrinsic molecular subtyping of UC. Next steps include, based on the recently accumulated understanding, the establishment of novel disease models representing UC metastasis in various experimental platforms, particularly in vivo animal systems. Indeed, novel knowledge molecular genetics has not been fully linked to the modeling of UC metastasis. Further understanding of bladder carcinogenesis is needed particularly with regard to cell of origin related to tumor characteristics including driver gene alterations, pathological differentiations, and metastatic ability. Then we will be able to establish better disease models, which will consequently lead us to further understanding of biology and eventually the development of novel therapeutic strategies for UC metastasis.

A Polycomb-mir200 loop regulates clinical outcome in bladder cancer

Bladder cancer (BC) is a highly prevalent disease, ranking fifth in the most common cancers worldwide. Various miRNAs have recently emerged as potential prognostic biomarkers in cancer. The miR-200 family, which repressed the epithelial-to-mesenchymal transition (EMT), is repressed in multiple advanced cancers. However, its expression and function in BC is still poorly understood. Here we show that miR-200 family displays increased expression, probably due to the activation of specific oncogenic signaling pathways, and reduced promoter methylation, in BC compared to normal bladder samples. Furthermore, we show that the expression of these miRNAs is decreased in high grade and stage tumors, and the down-regulation is associated with patient's poor clinical outcome. Our data indicate that the miR-200 family plays distinct roles in Non-Muscle (NMIBC) and Muscle-Invasive BC (MIBC). In MIBC, miR-200 expression post transcriptionally regulates EMT-promoting transcription factors ZEB1 and ZEB2, whereas suppresses BMI1 expression in NMIBC. Interestingly, we show that increased EZH2 and/or BMI1 expression repress the expression of miR-200 family members. Collectively, these findings support a model of BC progression through a coordinated action between the Polycomb Repression Complex (PRC) members repressing the miR-200 expression, which ultimately favors invasive BC development. Since pharmacological inhibition of EZH2 in BC cell lines lead to increased miR-200 expression, our findings may support new therapeutic strategies for BC clinical management.

The downregulation of ΔNp63 in p53-deficient mouse epidermal tumors favors metastatic behavior

The TP63 gene codes for two major isoform types, TAp63 and ΔNp63, with probable opposite roles in tumorigenesis. The ΔNp63α protein is frequently amplified and overexpressed in different epithelial tumors. Accordingly, it has been considered a potential oncogene. Nonetheless, a possible metastatic suppressor activity has also been suggested based on the experimental observation that its expression is reduced or even absent in advanced invasive tumors. Such metastatic suppressor activities are often related to tumors bearing point mutated TP53 gene. However, its potential roles in TP53-deficient tumors are poorly characterized. Here we show that in spontaneous tumors, induced by the epidermal-specific Trp53 ablation, the reduction of ΔNp63 expression is an early event, whereas it is re-expressed in the lung metastatic lesions. Using knock down and ectopic expression approaches, we show that ΔNp63 expression opposes the epithelial-mesenchymal transition and reduces the metastatic potential of the cells. This process occurs through the modulation of ΔNp63-dependent downstream targets (including transcription factors and microRNAs) likely to play metastatic roles. Further, ΔNp63 also favors the expression of factors involved in iPS reprogramming, thus suggesting that it can also modulate specific stem cell traits in mouse epidermal tumor cells. Overall, our data assign antimetastatic roles to ΔNp63 in the context of p53 deficiency and epidermis.

Epithelial-To-Mesenchymal Transition and Its Correlation With Clinicopathologic Features in Patients With Urothelial Carcinoma of the Bladder

INTRODUCTION

Epithelial-to-mesenchymal transition (EMT) is a dynamic process in the pathogenesis of urinary bladder cancer. Despite significant advancements in its diagnosis and treatment, the outcomes have more or less remained the same. In the present study, the expression of EMT markers was investigated to evaluate its prognostic significance in patients with non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC).

MATERIALS AND METHODS

The present study was undertaken to examine the expression of EMT markers, including E-cadherin, N-cadherin, vimentin, Snail, Twist, Zeb, and Slug, on 28 bladder tumor tissues (15 cases of NMIBC and 13 of MIBC) using reverse transcription-polymerase chain reaction. Immunohistochemical (IHC) staining was performed to check the protein expression and localization of E-cadherin, N-cadherin, vimentin, Snail, and Slug.

RESULTS

At the message level, reduced expression of E-cadherin correlated with gender (P = .004), enhanced expression of N-cadherin correlated with stage and age (P = .02, for both), and increased expression of EMT transcription factors correlated significantly with stage, grade, or age. Inverse correlation of reduced levels of E-cadherin were observed with new expression of N-cadherin (P = .001; Mann-Whitney U test) and vimentin (P = .001; Mann-Whitney U test). On IHC, novel expression of vimentin and N-cadherin was associated with enhanced expression of Snail and Slug (P = .005; Wilcoxon signed rank test).

CONCLUSION

Molecular validation of the EMT marker profile proved to be a sensitive and an effective prognostic tool for objective and systematic investigation of EMT function in the pathogenesis of urinary bladder cancer. Nevertheless, further studies are required with a greater number of clinical samples.

Targeting Epithelial-Mesenchymal Transition (EMT) to Overcome Drug Resistance in Cancer

Epithelial–mesenchymal transition (EMT) is known to play an important role in cancer progression, metastasis and drug resistance. Although there are controversies surrounding the causal relationship between EMT and cancer metastasis, the role of EMT in cancer drug resistance has been increasingly recognized. Numerous EMT-related signaling pathways are involved in drug resistance in cancer cells. Cells undergoing EMT show a feature similar to cancer stem cells (CSCs), such as an increase in drug efflux pumps and anti-apoptotic effects. Therefore, targeting EMT has been considered a novel opportunity to overcome cancer drug resistance. This review describes the mechanism by which EMT contributes to drug resistance in cancer cells and summarizes new advances in research in EMT-associated drug resistance.

miR-92b targets DAB2IP to promote EMT in bladder cancer migration and invasion

Muscle-invasive or metastatic bladder cancer (BCa) has a very poor prognosis; however, its mechanisms remain largely unknown. Previous studies have discovered multiple microRNAs (miRs) that are involved in BCa progression and regarded as potential biomarkers or therapeutic targets. In this study, we demonstrated that miR-92b could uniquely promote cell migration and invasion of BCa cells, but had no effect on cell proliferation. Mechanistically, our data provided evidence to verify that miR-92b was able to directly target DAB2IP, a well-known tumor suppressor, and inhibit epithelial‑mesenchymal transition of BCa cells. Moreover, the increased expression levels of miR-92b were negatively correlated with DAB2IP, and predicted poor prognosis of patients with BCa. Overall, this study reveals a new promising biomarker and its mechanisms contributing to BCa invasion or metastasis.

IKK inhibitor suppresses epithelial-mesenchymal transition and induces cell death in prostate cancer

IκB kinase (IKK)/nuclear factor κB (NF-κB) pathway activation is a key event in the acquisition of invasive and metastatic capacities in prostate cancer. A potent small-molecule compound, BMS-345541, was identified as a highly selective IKKα and IKKβ inhibitor to inhibit kinase activity. This study explored the effect of IKK inhibitor on epithelial-mesenchymal transition (EMT), apoptosis and metastasis in prostate cancer. Here, we demonstrate the role of IKK inhibitor reducing proliferation and inducing apoptosis in PC-3 cells. Furthermore, BMS345541 inhibited IκBα phosphorylation and nuclear level of NF-κB/p65 in PC-3 cells. We also observed downregulation of the N-cadherin, Snail, Slug and Twist protein in a dose-dependent manner. BMS‑345541 induced upregulation of the epithelial marker E-cadherin and phosphorylated NDRG1 at protein level. Moreover, BMS‑345541 reduced invasion and metastasis of PC-3 cells in vitro. In conclusion, IKK has a key role in both EMT and apoptosis of prostate cancer. IKK inhibitor can reverse EMT and induce cell death in PCa cells. IKK was identified as a potential target structure for future therapeutic intervention in PCa.

Selective Pro-Apoptotic Activity of Novel 3,3'-(Aryl/Alkyl-Methylene)Bis(2-Hydroxynaphthalene-1,4-Dione) Derivatives on Human Cancer Cells via the Induction Reactive Oxygen Species

Selective induction of apoptosis in cancer cells barring the normal cells is considered as an effective strategy to combat cancer. In the present study, a series of twenty-two (22) synthetic 3,3'-(aryl/alkyl-methylene)bis(2-hydroxynaphthalene-1,4-dione) bis-lawsone derivatives were assayed for their pro-apoptotic activity in six different cell lines (five cancerous and one normal) using MTT assay. Out of these 22 test compounds, 1j was found to be the most effective in inducing apoptosis in human glioma cells (CCF-4) among the different cell lines used in the study. The activity of this compound, 1j, was then compared to a popular anticancer drug, cisplatin, having limited usage because of its nephrotoxic nature. In this study, 1j derivative showed much less toxicity to the normal kidney cells compared to cisplatin, thus indicating the superiority of 1j as a possible anticancer agent. This compound was observed to induce apoptosis in the glioma cells by inducing the caspase dependent apoptotic pathways via ROS and downregulating the PI3K/AKT/mTOR pathway. Estimation of different oxidative stress markers also confirms the induction of oxidative stress in 1j exposed cancer cells. The toxicity of 1j compound toward cancer cells was confirmed further by different flow cytometrical analyses to estimate the mitochondrial membrane potential and cell cycle. The sensitivity of malignant cells to apoptosis, provoked by this synthetic derivative in vitro, deserves further studies in suitable in vivo models. These studies not only identified a novel anticancer drug candidate but also help to understand the metabolism of ROS and its application in cancer treatment.

Hedgehog pathway is involved in nitidine chloride induced inhibition of epithelial-mesenchymal transition and cancer stem cells-like properties in breast cancer cells

Background

The complications of clinical metastatic disease are responsible for the majority of breast cancer related deaths, and fewer therapies substantially prolong survival. Nitidine chloride (NC), a natural polyphenolic compound, has been shown to exhibit potent anticancer effects in many cancer types, including breast cancer. The epithelial-mesenchymal transition (EMT) and the acquisition of cancer stem cells (CSCs)-like properties emerge as critical steps in the metastasis of human cancers. However, the effects of NC on the EMT and the CSCs-like properties in breast cancer cells, and the underlying molecular mechanisms are not fully understood.

Results

In the present study, MDA-MB-468 and MCF-7 cancer cells were treated with NC. Scratch and Transwell assays were performed to determine whether NC could attenuate the migratory and invasive capability of cancer cells; Mammosphere formation and flow cytometry analysis were performed to confirm that NC decreased CSCs-like phenotype; RT-PCR and western blot analysis were used to examine the expression level of EMT and CSC related markers in both cells. Mechanistically, NC could inhibit the components of Hedgehog pathway (smoothened, patched, Gli1 and Gli2), subsequently inhibited the expression of Snail, Slug and Zeb1, which were correlated with the significant changes of the expression of EMT related markers (N-cadherin, E-cadherin, and Vimentin) to reverse EMT. On the other hand, NC could also inhibit the expression of CSCs related factors such as Nanog, Nestin, Oct-4 and CD44 via Hedgehog pathway. Furthermore, transforming growth factor-β1 (TGF-β1)-induced increment of EMT and CSCs properties could be reversed by NC.

Conclusions

Taken together, these data indicated that NC suppressed breast cancer EMT and CSCs-like properties through inhibiting Hedgehog signaling pathway. Our study suggested that NC may be a potential anticancer agent for breast cancer.

Synergistic reversal effect of epithelial-to-mesenchymal transition by miR-223 inhibitor and genistein in gemcitabine-resistant pancreatic cancer cells

Emerging studies have demonstrated that EMT phenotype is closely related with tumor progression and drug resistance in a variety of human cancers. Recently, it has been extensively demonstrated that microRNAs (miRNAs) play a pivotal role in regulating EMT. In our previously reports, we have reported that inhibition of miR-223 could reverse EMT phenotype and improve chemotherapeutic drug sensitivity. We also reported that genistein down-regulated miR-223 expression in gemcitabine-resistant (GR) pancreatic cancer cells. Here, we explored whether there was the synergistic effect between miR-223 inhibitor and genistein on cell growth, migration, invasion and reversal of EMT in GR pancreatic cancer. We found that the combination of miR-223 inhibitor and genistein synergistically reduced cell motility and invasion and enhanced gemcitabine sensitivity in GR cells. In addition, we further observed that miR-223 inhibitor and genistein reversed EMT features in GR cells. This study suggests that the combination of miR-223 inhibitor and genistein may be a potential therapeutic strategy for the treatment of pancreatic cancer.

Characteristics of bladder transitional cell carcinoma with E-cadherin and N-cadherin double-negative expression

The aim of the present study was to examine the characteristics of bladder transitional cell carcinoma with E-cadherin and N-cadherin double-negative expression. An immunofluorescence assay was used to detect E-cadherin and N-cadherin expression in infiltrative bladder cancer tissues, and immunofluorescence and western blot analysis were used to detect E-cadherin and N-cadherin expression in human urinary bladder grade II carcinoma 5637, transitional cell carcinoma UMUC-3 and invasive bladder carcinoma EJ cells. Cell proliferation, migration, invasion and plate colony formation assays were used to detect the proliferative, migratory and invasive abilities and the efficiency of plate colony formation of 5637, UMUC3 and EJ cells. A tumor xenograft formation assay was used to evaluate the tumorigenic abilities of 5637, UMUC-3 and EJ cells in vivo. E-cadherin and N-cadherin double-negative expression was identified in various pathological grades of infiltrative bladder cancers. E-cadherin positive and N-cadherin negative expression was exhibited by 5637 cells. By contrast, E-cadherin negative and N-cadherin positive expression was exhibited by EJ cells, and E-cadherin and N-cadherin double-negative expression was exhibited by UMUC-3 cells. The ability of cells to proliferate, migrate, invade, and the efficiency of plate colony formation and tumorigenic abilities of the cells were significantly different among 5637, UMUC-3 and EJ cells. These cell characteristics were significantly increased in UMUC-3 cells compared with 5637 cells; however, the characteristics were significantly decreased compared with EJ cells. The biological characteristics of bladder cancer cells with E-cadherin and N-cadherin double-negative expression was between bladder cancer cells that exhibited a E-cadherin positive and N-cadherin negative expression, and bladder cancer cells that exhibited E-cadherin negative and N-cadherin positive expression. The present study deduces that the status of E-cadherin and N-cadherin double-negative expression may participate in the process of epithelial-mesenchymal transition in the pathogenesis of bladder urothelial carcinoma.

miR-139-5p Inhibits the Epithelial-Mesenchymal Transition and Enhances the Chemotherapeutic Sensitivity of Colorectal Cancer Cells by Downregulating BCL2

MicroRNAs (miRNAs) are important regulators involved in various cancers, including colorectal cancer (CRC). The functions and mechanisms of the miRNAs involved in CRC progress and metastasis are largely unknown. In this study, miRNA microarray analysis was performed to screen crucial miRNAs involved in CRC progress, and miR-139-5p was chosen for further study. The functional roles of miR-139-5p in colon cancer were demonstrated by CCK-8 proliferation assay, cell invasion and migration, cell apoptosis and in a KO mouse study. miR-139-5p expression was significantly decreased in cancer tissues compared to normal tissues. The miR-139-5p expression level was associated with tumour stage (P < 0.01). Function studies revealed that miR-139-5p was significantly correlated with the metastasis potential and drug resistance of colon cancer cells by affecting the epithelial-mesenchymal transition (EMT). Then, we identified BCL2 as a direct target of miR-139-5p cells in vitro. The patient samples and KO mice model showed that BCL2 expression was inversely correlated with the expression of miR-139-5p. In conclusion, we found that miR-139-5p targeted the BCL2 pathway to reduce tumour metastasis and drug sensitivity in CRC. This axis provided insight into the mechanism underlying miRNA regulation of CRC metastasis and a novel therapeutic target for CRC therapy.

Exploring the role of sphingolipid machinery during the epithelial to mesenchymal transition program using an integrative approach

The epithelial to mesenchymal transition (EMT) program is activated in epithelial cancer cells and facilitates their ability to metastasize based on enhanced migratory, proliferative, anti-apoptotic, and pluripotent capacities. Given the fundamental impact of sphingolipid machinery to each individual process, the sphingolipid-related mechanisms might be considered among the most prominent drivers/players of EMT; yet, there is still limited knowledge. Given the complexity of the interconnected sphingolipid system, which includes distinct sphingolipid mediators, their synthesizing enzymes, receptors and transporters, we herein apply an integrative approach for assessment of the sphingolipid-associated mechanisms underlying EMT program. We created the sphingolipid-/EMT-relevant 41-gene/23-gene signatures which were applied to denote transcriptional events in a lung cancer cell-based EMT model. Based on defined 35-gene sphingolipid/EMT-attributed signature of regulated genes, we show close associations between EMT markers, genes comprising the sphingolipid network at multiple levels and encoding sphingosine 1-phosphate (S1P)-/ceramide-metabolizing enzymes, S1P and lysophosphatidic acid (LPA) receptors and S1P transporters, pluripotency genes and inflammation-related molecules, and demonstrate the underlying biological pathways and regulators. Mass spectrometry-based sphingolipid analysis revealed an EMT-attributed shift towards increased S1P and LPA accompanied by reduced ceramide levels. Notably, using transcriptomics data across various cell-based perturbations and neoplastic tissues (24193 arrays), we identified the sphingolipid/EMT signature primarily in lung adenocarcinoma tissues; besides, bladder, colorectal and prostate cancers were among the top-ranked. The findings also highlight novel regulatory associations between influenza virus and the sphingolipid/EMT-associated mechanisms. In sum, data propose the multidimensional contribution of sphingolipid machinery to pathological EMT and may yield new biomarkers and therapeutic targets.

Epithelial-mesenchymal transition: a new target in anticancer drug discovery

The conversion of cells with an epithelial phenotype into cells with a mesenchymal phenotype, referred to as epithelial-mesenchymal transition, is a critical process for embryonic development that also occurs in adult life, particularly during tumour progression. Tumour cells undergoing epithelial-mesenchymal transition acquire the capacity to disarm the body's antitumour defences, resist apoptosis and anticancer drugs, disseminate throughout the organism, and act as a reservoir that replenishes and expands the tumour cell population. Epithelial-mesenchymal transition is therefore becoming a target of prime interest for anticancer therapy. Here, we discuss the screening and classification of compounds that affect epithelial-mesenchymal transition, highlight some compounds of particular interest, and address issues related to their clinical application.

Quantitative Analysis of Differential Proteome Expression in Epithelial-to-Mesenchymal Transition of Bladder Epithelial Cells Using SILAC Method

Epithelial-to-mesenchymal transition (EMT) is an essential biological process involved in embryonic development, cancer progression, and metastatic diseases. EMT has often been used as a model for elucidating the mechanisms that underlie bladder cancer progression. However, no study to date has addressed the quantitative global variation of proteins in EMT using normal and non-malignant bladder cells. We treated normal bladder epithelial HCV29 cells and low grade nonmuscle invasive bladder cancer KK47 cells with transforming growth factor-beta (TGF-β) to establish an EMT model, and studied non-treated and treated HCV29 and KK47 cells by the stable isotope labeling amino acids in cell culture (SILAC) method. Labeled proteins were analyzed by 2D ultrahigh-resolution liquid chromatography/LTQ Orbitrap mass spectrometry. Among a total of 2994 unique identified and annotated proteins in HCV29 and KK47 cells undergoing EMT, 48 and 56 proteins, respectively, were significantly upregulated, and 106 and 24 proteins were significantly downregulated. Gene ontology (GO) term analysis and pathways analysis indicated that the differentially regulated proteins were involved mainly in enhancement of DNA maintenance and inhibition of cell-cell adhesion. Proteomes were compared for bladder cell EMT vs. bladder cancer cells, revealing 16 proteins that displayed similar changes in the two situations. Studies are in progress to further characterize these 16 proteins and their biological functions in EMT.

MicroRNA Regulation of Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is a central regulatory program that is similar in many aspects to several steps of embryonic morphogenesis. In addition to its physiological role in tissue repair and wound healing, EMT contributes to chemo resistance, metastatic dissemination and fibrosis, amongst others. Classically, the morphological change from epithelial to mesenchymal phenotype is characterized by the appearance or loss of a group of proteins which have come to be recognized as markers of the EMT process. As with all proteins, these molecules are controlled at the transcriptional and translational level by transcription factors and microRNAs, respectively. A group of developmental transcription factors form the backbone of the EMT cascade and a large body of evidence shows that microRNAs are heavily involved in the successful coordination of mesenchymal transformation and vice versa, either by suppressing the expression of different groups of transcription factors, or otherwise acting as their functional mediators in orchestrating EMT. This article dissects the contribution of microRNAs to EMT and analyzes the molecular basis for their roles in this cellular process. Here, we emphasize their interaction with core transcription factors like the zinc finger enhancer (E)-box binding homeobox (ZEB), Snail and Twist families as well as some pluripotency transcription factors.

Research advances in HMGN5 and cancer

High-mobility group nucleosome-binding domain 5 (HMGN5) is a new member of the high-mobility group N (HMGN) protein family that is involved in nucleosomal binding and transcriptional activation. It was first discovered in mouse, and recent studies found that the expressions of HMGN5 in many human cancers were also highly regulated, such as prostate, bladder, breast, and lung and clear cell renal cell carcinoma. Numerous reports have demonstrated that HMGN5 plays significant roles in many biological and pathological conditions, such as in developmental defects, hypersensitivity to stress, embryonic stem cell differentiation, and tumor progression. Importantly, deficiency of HMGN5 has been shown to be linked to cancer cell growth, cell cycle regulation, migration, invasion, and clinical outcomes, and it represents a promising therapeutic target for many malignant tumors. In the present review, we provide an overview of the current knowledge concerning the role of HMGN5 in cancer development and progression.

Promoter-associated endogenous and exogenous small RNAs suppress human bladder cancer cell metastasis by activating p21 (CIP1/WAF1) expression

Accumulating data suggest that micro RNAs (miRNAs) or double-stranded RNAs (dsRNAs) can activate gene expression by targeting promoters. The cyclin-dependent kinase inhibitor p21 (CIP1/WAF1) (p21) has also been shown to suppress epithelial-mesenchymal transition (EMT) which plays a crucial role in the early stage of tumor metastases and invasiveness. In a previous study, we have reported that miR-370-5p is low-expressed in bladder cancer (BCa) tissues and cell lines. Here, we identified that miR-370-5p and sequence homology dsRNA (dsP21-555) fully complementary to promoter hold the potent abilities to induce p21 expression. Moreover, transfection of miR-370-5p or dsP21-555 into BCa cells remarkably inverts EMT-associated genes (increases epithelial cell makers E-cadherin and β-catenin, and decreases mesenchymal cell markers ZEB1 and Vimentin) expression mainly via regulating p21 expression. Besides, through manipulating p21, both the candidates can retard BCa cell migration and invasion. In summary, our results provide evidence that both endogenous and exogenous small RNAs may function to induce p21 expression by interacting with the similar promoter region and impede BCa metastasis.

Interleukin-6 as a potential molecular target in esophageal squamous cell carcinoma

Knowledge of potential tumor markers may improve chemotherapeutic efficacy. Interleukin-6 (IL-6) expression in local tumor tissues is associated with cancer progression and poor prognosis in variety of cancer types. The aim of the present study was to investigate the role and potential application of IL-6 in determining the prognosis of esophageal carcinoma. KYSE170 and TE13 esophageal cancer cell lines were used to conduct cell- and animal-based experiments investigating biological changes and tumor behavior. Immunohistochemical analysis revealed that 70–80% of cancer cells exhibited positive staining for IL-6, compared with <15% of non-malignant epithelial cells. These immunohistochemical results were consistent with the mRNA expression levels detetced. The IL-6 silencing vector significantly reduced invasion and proliferation of the two cell lines and attenuated tumor growth in xenograft mouse models (P<0.05). The IL-6 silencing vector markedly reduced the presence of Ki-67 (a typical proliferation marker) and microvessel density, indicating that downregulation of IL-6 levels may greatly affect tumor growth and inhibition. The IL-6 silencing vector increased E-cadherin and matrix metalloproteinase (MMP)-9 expression levels in the two esophageal carcinoma cell lines. This vector also regulated the release of IL-6 in cell supernatant and serum in KYSE170- and TE13-tumor-bearing mice. The secretion of vascular endothelial growth factor and cluster of differentiation 31 (a nuclear protein) immunoreactive molecules were also reduced by the IL-6 silencing vector. Therefore, IL-6 may be an important trigger in the progression of angiogenesis and endothelial tube formation within the tumor, and targeting IL-6 may be a promising strategy for the treatment of esophageal cancer.

Epithelial-mesenchymal transition contributes to docetaxel resistance in human non-small cell lung cancer

Lung cancer is an aggressive malignancy with high morbidity and mortality. Chemotherapy has always been the principal treatment measure, but its acquired resistance becomes a critical problem. In the current study, we established a new docetaxel-resistant human non-small lung cancer (NSCLC) cell line A549/Docetaxel. The resistance index (RI) of A549/Docetaxel cells and A549 induced by TGF-β to docetaxel were 8.91 and 11.5, respectively. Compared to the parental A549 cells, the multiplication time of A549/Docetaxel was prolonged, the proportion of the cell cycle in the S phase decreased while that in the G1 phase increased, and apoptotic rate was much lower. The morphology of the resistant cells eventuated epithelial-mesenchymal transition (EMT), which was confirmed by the higher expression of fibronectin, vimentin (mesenchymal markers), and lower expression of E-cadherin (epithelial marker) at mRNA and proteins levels. Furthermore, the representative markers for docetaxel resistance were examined, including ABCB1 (MDR1), Bcl-2, Bax, and tubulin, to figure out the mechanisms of the resistance of A549/Docetaxel. In summary, we have established a typical docetaxel-resistant human NSCLC cell line A549/Docetaxel, and it was suggested that the multidrug resistance of A549/Docetaxel was related to EMT.

S100A4 participates in epithelial-mesenchymal transition in breast cancer via targeting MMP2

Numerous studies have shown that S100A4 acquires its metastasis-promoting effects via inducing epithelial-mesenchymal transition (EMT). However, its role and mechanism in EMT in breast cancer had not been clearly elucidated. Herein, we showed that the knockdown of S100A4 expression in breast cancer cell lines, MDA-MB-231 and MDA-MB-468, inhibited not only cell invasion ability greatly, but also the occurrence of EMT significantly. In addition, S100A4 knockdown could also decrease the expression of MMP2, a promoter and a mediator of the EMT processes in cancer. Above all, restoring the expression of MMP2 in MDA-MB-231 and MDA-MB-468 could not only rescue the invasion ability inhibited by knockdown of S100A4, but also reverse the EMT suppressed by knockdown of S100A4. In summary, our results indicated that S100A4 could promote the invasion ability of breast cancer cells via EMT, more importantly, it could participate in EMT via regulating MMP2 in breast cancer. Therefore, S100A4 could be a candidate biomarker for defining breast cancer metastasis and useful target for therapy.

Prognostic and predictive factors in patients treated with chemotherapy for advanced urothelial cancer: where do we stand?

The standard of care for patients with local advanced or metastatic urothelial carcinoma is chemotherapy. However, results with this are rather disappointing, and validated prognostic factors and biomarkers of tumor response, which are useful in the decision-making process, are still lacking. PubMed databases were searched for articles published until November 2013. Several promising clinical and biological candidate prognostic factors or markers of tumor response to first- or second-line therapy, such as hemoglobin, performance status, visceral metastasis and ERCC1, hENT1 and EMT markers, have been identified and described in this article. In summary, clinical parameters and molecular profiling could revolutionize the management of local advanced or metastatic urothelial cancer, but an improvement in individualized therapeutic approaches still seems distant.

DNMT1-dependent suppression of microRNA424 regulates tumor progression in human bladder cancer

The aim of this study was to examine the role of miRNAs regulation by DNMT1 and its underlying mechanisms in bladder cancer. The choice of target miRNAs was based on the analysis of a TaqMan MicroRNA Panel assay. The role of target miRNA in tumor behavior and the related signaling pathways were assessed using the human bladder cancer cell lines. We also evaluated the predictive power of the target miRNA and its link to DNMT1 from 124 clinical bladder cancer specimens. Our results revealed that the miR-424 level is significantly increased when blocking DNMT1 in bladder cancer cells. From the clinical specimen analysis, the staining of miR-424 was inversely correlated with DNMT1 immunoreactivity. The lack of miR-424 expression was significantly linked to aggressive tumor growth, advanced clinical stage and poor prognosis in bladder cancer. Increased miR-424 suppressed the tumor growth rate and invasion ability determined in vitro and in vivo. Furthermore, the EGFR pathway plays a role in the transmission of the miR-424 signal that regulates cell growth and the epithelial-to-mesenchymal transition. These results highlight a potential role for miR-424 as a molecular predictor and therapeutic target in bladder cancer.

Knockdown of eIF3D inhibits breast cancer cell proliferation and invasion through suppressing the Wnt/β-catenin signaling pathway

eIF3D (eukaryotic translation initiation factor 3 subunit D) is one member of the eIF3 family and plays a critical role in translation initiation. Previous studies showed that it was involved in the development and progression of several tumors. However, the role of eIF3D in breast cancer and the underlying mechanism is still unclear. Therefore, this study set out to investigate the role of eIF3D in breast cancer. Our results demonstrated that eIF3D is up-regulated in breast cancer cells. Knockdown of eIF3D inhibited breast cancer cell proliferation and invasion. In addition, knockdown of eIF3D inhibited the expression of β-catenin, cyclin D1 and c-Myc in breast cancer cells. Taken together, our findings show that siRNA-eIF3D inhibits breast cancer cell proliferation and invasion through suppressing the Wnt/β-catenin signaling pathway. Therefore, eIF3D may be a good molecular target for the prevention and treatment of breast cancer.

Urothelial cells undergo epithelial-to-mesenchymal transition after exposure to muscle invasive bladder cancer exosomes

Bladder cancer, the fourth most common noncutaneous malignancy in the United States, is characterized by high recurrence rate, with a subset of these cancers progressing to a deadly muscle invasive form of disease. Exosomes are small secreted vesicles that contain proteins, mRNA and miRNA, thus potentially modulating signaling pathways in recipient cells. Epithelial-to-mesenchymal transition (EMT) is a process by which epithelial cells lose their cell polarity and cell–cell adhesion and gain migratory and invasive properties to become mesenchymal stem cells. EMT has been implicated in the initiation of metastasis for cancer progression. We investigated the ability of bladder cancer-shed exosomes to induce EMT in urothelial cells. Exosomes were isolated by ultracentrifugation from T24 or UMUC3 invasive bladder cancer cell conditioned media or from patient urine or bladder barbotage samples. Exosomes were then added to the urothelial cells and EMT was assessed. Urothelial cells treated with bladder cancer exosomes showed an increased expression in several mesenchymal markers, including α-smooth muscle actin, S100A4 and snail, as compared with phosphate-buffered saline (PBS)-treated cells. Moreover, treatment of urothelial cells with bladder cancer exosomes resulted in decreased expression of epithelial markers E-cadherin and β-catenin, as compared with the control, PBS-treated cells. Bladder cancer exosomes also increased the migration and invasion of urothelial cells, and this was blocked by heparin pretreatment. We further showed that exosomes isolated from patient urine and bladder barbotage samples were able to induce the expression of several mesenchymal markers in recipient urothelial cells. In conclusion, the research presented here represents both a new insight into the role of exosomes in transition of bladder cancer into invasive disease, as well as an introduction to a new platform for exosome research in urothelial cells.

Immunoexpression of N-cadherin, Twist and Vimentin in Bladder Urothelial Carcinomas

Purpose: Epithelial mesenchymal transition consists in the acquisition of neoplastic epithelial cells of a mesenchymal phenotype the process being involved in cancers invasion and metastasis. In this study were analyzed the expression of N-cadherin, Twist and Vimentin in bladder urothelial carcinomas according to the main prognostic parameters. Material/Methods: The study included 20 bladder urothelial carcinomas which were analyzed histopathological, immunohistochemical and statistical. Results: N-cadherin was identified in 45% of cases, which belonged to high-grade carcinomas with deep invasion and lymph node metastases. Twist immunoreaction was identified in all cases and was significantly increased in advanced stages carcinomas. Vimentin was present only in the advancing edge in 25% of cases, which belonged to highly invasive carcinomas. Urothelial carcinoma metastases were N-cadherin and Twist and Vimentin negative. We found a linear positive distribution of N-cadherin and Twist values. Conclusion: the used markers are useful for identifying aggressive urothelial carcinomas in the context of reciprocal stimulation mechanisms inside of urothelial epithelial-mesenchymal transition process.

A set of NF-κB-regulated microRNAs induces acquired TRAIL resistance in lung cancer

TRAIL (TNF-related apoptosis-inducing ligand) is a promising anticancer agent that can be potentially used as an alternative or complementary therapy because of its specific antitumor activity. However, TRAIL can also stimulate the proliferation of cancer cells through the activation of NF-κB, but the exact mechanism is still poorly understood. In this study, we show that chronic exposure to subtoxic concentrations of TRAIL results in acquired resistance. This resistance is associated with the increase in miR-21, miR-30c, and miR-100 expression, which target tumor-suppressor genes fundamental in the response to TRAIL. Importantly, down-regulation of caspase-8 by miR-21 blocks receptor interacting protein-1 cleavage and induces the activation of NF-κB, which regulates these miRNAs. Thus, TRAIL activates a positive feedback loop that sustains the acquired resistance and causes an aggressive phenotype. Finally, we prove that combinatory treatment of NF-κB inhibitors and TRAIL is able to revert resistance and reduce tumor growth, with important consequences for the clinical practice.

Emerging concepts on drug resistance in bladder cancer: Implications for future strategies

The combination chemotherapies with methotrexate plus vinblastine, doxorubicin and cisplatin (MVAC or CMV regimens) or gemcitabine plus cisplatin represent the standard as first-line therapy for patients with metastatic urothelial cancer. In Europe, vinflunine is an option for second-line therapy for patients progressed during first-line or perioperative platinum-containing regimen. Alternative regimens containing taxanes and/or gemcitabine may be valuated case by case. Furthermore, carboplatin should be considered in patients unfit for cisplatin both in the first and second-line setting. Based on these findings, a better comprehension of the mechanisms underlying the development of drug resistance in patients with bladder cancer will represent a major step forward in optimizing patients' outcome. This article reviews the current knowledge of the mechanisms and emerging strategies to overcome resistance in patients with advanced urothelial cancer.

Twist1 is a potential prognostic marker for colorectal cancer and associated with chemoresistance

Twist1 is a highly conserved basic helix-loophelix transcription factor, and has been shown to play an important role in carcinogenesis of many tumors including colorectal cancer (CRC). Here we aimed to investigate the role of Twist1 in the clinical significance and chemoresistance in CRC. In this study, we examined the correlation between Twist1 expression and clinicopathological characteristics using immunohistochemistry in patients with CRC. The molecular mechanisms of Twist1 expression and its effects on chemosensitivity to 5-Fluorouracil and oxaliplatin were also explored by MTT assay, colony forming assay, flow cytometry assay. The results indicate that Twist1 is overexpressed in cancer tissue, and its positive expression are related to histological grade (P=0.004), T-stage (P=0.033), N-stage (P=0.000), M-stage (P=0.040), TNM stage (P=0.002) and recurrence (P=0.023). Moreover, positive Twist1 expression is correlated with poor overall survival in CRC patients (P<0.0001), and is a significant independent prognostic indicator. In addition, we show that knockdown of Twist1 inhibits proliferation, and increased the percentage of apoptotic cells of CRC cell lines. Our findings suggest that Twist1 promotes proliferation and chemoresistance of CRC cells. Twist1 may be a potential prognostic marker and a molecular target for therapies.

γ-Secretase inhibitor inhibits bladder cancer cell drug resistance and invasion by reducing epithelial-mesenchymal transition

A previous study by our group demonstrated that the expression levels of Notch 1 and Jagged 1 in bladder cancer cells was significantly lower compared with those in normal bladder mucosa, while the expression levels of Notch 1 and Jagged 1 in invasive bladder cancer were higher compared with those in superficial bladder cancer. The present study investigated the effect of the Notch signaling pathway on the drug resistance and invasiveness of bladder cancer cells. It was demonstrated that complete inhibition of the Notch signaling pathway induced significant morphological changes and inhibited cell proliferation and migration (P<0.05). Reverse transcription quantitative polymerase chain reaction and western blot analyses revealed that the mRNA and protein expression levels of E-cadherin were upregulated (P<0.05) and the mRNA and protein expression levels of N-cadherin, vimentin and α-smooth muscle actin were downregulated (P<0.05). The present study concluded that complete inhibition of the Notch signaling pathway inhibited cell proliferation and invasion, and reduced drug resistance in bladder cancer cells, a phenomenon which may be associated with the inhibition of the epithelial-mesenchymal transition.

Adaptor protein CRK induces epithelial-mesenchymal transition and metastasis of bladder cancer cells through HGF/c-Met feedback loop

We have previously reported that an adaptor protein CRK, including CRK-I and CRK-II, plays essential roles in the malignant potential of various aggressive human cancers, suggesting the validity of targeting CRK in molecular targeted therapy of a wide range of cancers. Nevertheless, the role of CRK in human bladder cancer with marked invasion, characterized by distant metastasis and poor prognosis, remains obscure. In the present study, immunohistochemistry indicated a striking enhancement of CRK-I/-II, but not CRK-like, in human bladder cancer tissues compared to normal urothelium. We established CRK-knockdown bladder cancer cells using 5637 and UM-UC-3, which showed a significant decline in cell migration, invasion, and proliferation. It is noteworthy that an elimination of CRK conferred suppressed phosphorylation of c-Met and the downstream scaffold protein Gab1 in a hepatocyte growth factor-dependent and -independent manner. In epithelial–mesenchymal transition-related molecules, E-cadherin was upregulated by CRK elimination, whereas N-cadherin, vimentin, and Zeb1 were downregulated. A similar effect was observed following treatment with c-Met inhibitor SU11274. Depletion of CRK significantly decreased cell proliferation of 5637 and UM-UC-3, consistent with reduced activity of ERK. An orthotopic xenograft model with bioluminescent imaging revealed that CRK knockdown significantly attenuated not only tumor volume but also the number of circulating tumor cells, resulted in a complete abrogation of metastasis. Taken together, this evidence uncovered essential roles of CRK in invasive bladder cancer through the hepatocyte growth factor/c-Met/CRK feedback loop for epithelial–mesenchymal transition induction. Thus, CRK might be a potent molecular target in bladder cancer, particularly for preventing metastasis, leading to the resolution of clinically longstanding critical issues.

Establishment and characterization of GCSR1, a multi-drug resistant signet ring cell gastric cancer cell line

Signet ring cell gastric cancer (SRCGC) has very poor prognosis worldwide, and studying its molecular characteristics is urgent for improving the outcome. However, few well-characterized SRCGC cell lines are available for research. Therefore, we established a novel cell line GCSR1, from a Chinese male SRCGC patient. Cell morphology of GCSR1 in culture, maintained in vitro for over 90 passages, is similar to the cells from the patient. GCSR1 cells proliferated in vitro with a doubling time of 67.65 h. Karyotyping showed they were aneuploid. Missense mutation occurred in codon 193 of P53 and deletion occurred in exons 1 and 3 of P16. Results of CCK8 assay revealed that GCSR1 was more resistant to 5-fluorouracil (5-FU) and mitomycin (MMC) than other gastric cancer cell lines. Stem cell marker assay by flow cytometry showed that GCSR1 had high proportion of CD44+ and/or CD133+ cells. It formed colonies easily in soft agar and generated xenograft tumors in nude mice. In conclusion, GCSR1 is a well-established, well-characterized multi-drug resistant cell line with abundant cancer stem cells.

SOX9 was involved in TKIs resistance in renal cell carcinoma via Raf/MEK/ERK signaling pathway

Renal cell carcinoma (RCC) is common genitourinary malignancy in human, 30-40% of patients with RCC would be diagnosed with metastatic RCC (mRCC). Even in the era of targeted therapy, patients with mRCC would inevitably progress due to drug resistance. Herein, exploration of the mechanisms of resistance is noteworthy to study. In the present study, we firstly reported the expression profile of SOX9 in renal carcinoma cells and tissues, and found that its expression was significantly associated with Fuhrman grading. Dual luciferase analysis confirmed that Raf/MEK/ERK pathway could directly be regulated by SOX9, and sequential experiments demonstrated that, renal carcinoma cells could sensitize to Sorafenib/Sunitinib through Raf/MEK/ERK signaling pathway inhibition regulated by SOX9 down-regulation. In a small cases with mRCC treated with Sorafenib/Sunitinib (n=38), comparative analysis showed that patients with SOX9 (-) had much better therapeutic response to TKIs than those with SOX9 (+) (PD: 9.1% vs. 56.2%, P=0.002, DCR: 90.9% vs. 43.8%, P=0.002). Based on these findings, we concluded that, SOX9 was firstly described to be highly expressed in renal cell carcinoma, and its expression was involved in TKIs drug resistance through activation of Raf/MEK/ERK pathway. In vitro, patients with SOX9 (-) was related to better response to TKIs treatment than those with SOX9 (+). SOX9 could be expected to be a promising biomarker predicting TKIs response and even expected to be another novel target in the treatment of mRCC.

Oncogenic HRAS Activates Epithelial-to-Mesenchymal Transition and Confers Stemness to p53-Deficient Urothelial Cells to Drive Muscle Invasion of Basal Subtype Carcinomas

Muscle-invasive urothelial carcinomas of the bladder (MIUCB) exhibit frequent receptor tyrosine kinase alterations, but the precise nature of their contributions to tumor pathophysiology is unclear. Using mutant HRAS (HRAS*) as an oncogenic prototype, we obtained evidence in transgenic mice that RTK/RAS pathway activation in urothelial cells causes hyperplasia that neither progresses to frank carcinoma nor regresses to normal urothelium through a period of one year. This persistent hyperplastic state appeared to result from an equilibrium between promitogenic factors and compensatory tumor barriers in the p19-MDM2-p53-p21 axis and a prolonged G2 arrest. Conditional inactivation of p53 in urothelial cells of transgenic mice expressing HRAS* resulted in carcinoma in situ and basal-subtype MIUCB with focal squamous differentiation resembling the human counterpart. The transcriptome of microdissected MIUCB was enriched in genes that drive epithelial-to-mesenchymal transition, the upregulation of which is associated with urothelial cells expressing multiple progenitor/stem cell markers. Taken together, our results provide evidence for RTK/RAS pathway activation and p53 deficiency as a combinatorial theranostic biomarker that may inform the progression and treatment of urothelial carcinoma.

Sonic hedgehog (Shh) signaling promotes tumorigenicity and stemness via activation of epithelial-to-mesenchymal transition (EMT) in bladder cancer

Activation of the sonic hedgehog (Shh) signaling pathway controls tumorigenesis in a variety of cancers. Here, we show a role for Shh signaling in the promotion of epithelial-to-mesenchymal transition (EMT), tumorigenicity, and stemness in the bladder cancer. EMT induction was assessed by the decreased expression of E-cadherin and ZO-1 and increased expression of N-cadherin. The induced EMT was associated with increased cell motility, invasiveness, and clonogenicity. These progression relevant behaviors were attenuated by treatment with Hh inhibitors cyclopamine and GDC-0449, and after knockdown by Shh-siRNA, and led to reversal of the EMT phenotype. The results with HTB-9 were confirmed using a second bladder cancer cell line, BFTC905 (DM). In a xenograft mouse model TGF-β1 treated HTB-9 cells exhibited enhanced tumor growth. Although normal bladder epithelial cells could also undergo EMT and upregulate Shh with TGF-β1 they did not exhibit tumorigenicity. The TGF-β1 treated HTB-9 xenografts showed strong evidence for a switch to a more stem cell like phenotype, with functional activation of CD133, Sox2, Nanog, and Oct4. The bladder cancer specific stem cell markers CK5 and CK14 were upregulated in the TGF-β1 treated xenograft tumor samples, while CD44 remained unchanged in both treated and untreated tumors. Immunohistochemical analysis of 22 primary human bladder tumors indicated that Shh expression was positively correlated with tumor grade and stage. Elevated expression of Ki-67, Shh, Gli2, and N-cadherin were observed in the high grade and stage human bladder tumor samples, and conversely, the downregulation of these genes were observed in the low grade and stage tumor samples. Collectively, this study indicates that TGF-β1-induced Shh may regulate EMT and tumorigenicity in bladder cancer. Our studies reveal that the TGF-β1 induction of EMT and Shh is cell type context dependent. Thus, targeting the Shh pathway could be clinically beneficial in the ability to reverse the EMT phenotype of tumor cells and potentially inhibit bladder cancer progression and metastasis.

Immunological basis in the pathogenesis and treatment of bladder cancer

The pathogenesis and transition of normal urothelium into bladder carcinoma are multifactorial processes. Chronic inflammation causes initiation and progression of the underlying pathophysiology of invasive and metastatic cancer. A dichotomy is observed in the role of immune cells in bladder cancer. While the immune response defends the host by suppressing neoplastic growth, several immune cells, including neutrophils, macrophages and T-lymphocytes, promote tumor development and progression. The levels of human neutrophil peptide-1, -2 and -3, produced by neutrophils, increase in bladder cancer and might promote tumor angiogenesis and growth. The effect of macrophages is primarily mediated by pro-inflammatory cytokines, IL-6 and TNF-α. In addition, the underlying immunological mechanisms of two treatments, BCG and cytokine gene-modified tumor vaccines, and future directions are critically discussed.

Pien Tze Huang Overcomes Multidrug Resistance and Epithelial-Mesenchymal Transition in Human Colorectal Carcinoma Cells via Suppression of TGF-β Pathway

The traditional Chinese medicine formula Pien Tze Huang (PZH) has long been used as a folk remedy for cancer. To elucidate the mode of action of PZH against cancer, in the present study we used a 5-FU resistant human colorectal carcinoma cell line (HCT-8/5-FU) to evaluate the effects of PZH on multidrug resistance (MDR) and epithelial-mesenchymal transition (EMT) as well as the activation of TGF-β pathway. We found that PZH dose-dependently inhibited the viability of HCT-8/5-FU cells which were insensitive to treatment of 5-FU and ADM, demonstrating the ability of PZH to overcome chemoresistance. Furthermore, PZH increased the intercellular accumulation of Rhodamine-123 and downregulated the expression of ABCG2 in HCT-8/5-FU cells. In addition, drug resistance induced the process of EMT in HCT-8 cells as evidenced by EMT-related morphological changes and alteration in the expression of EMT-regulatory factors, which however was neutralized by PZH treatment. Moreover, PZH inhibited MDR/EMT-enhanced migration and invasion capabilities of HCT-8 cells in a dose-dependent manner and suppressed MDR-induced activation of TGF-β signaling in HCT-8/5-FU cells. Taken together, our study suggests that PZH can effectively overcome MDR and inhibit EMT in human colorectal carcinoma cells via suppression of the TGF-β pathway.

Expression profile of epithelial-mesenchymal transition markers in non-muscle-invasive urothelial carcinoma of the bladder: correlation with intravesical recurrence following transurethral resection

OBJECTIVES

To evaluate the expression of molecular markers involved in epithelial-mesenchymal transition (EMT), a key process mediating the progression of malignant tumors, in non-muscle-invasive urothelial carcinoma of the bladder (NMIUCB) to clarify the significance of these markers as predictors of intravesical recurrence in patients treated with transurethral resection (TUR).

MATERIALS AND METHODS

Expression levels of 13 EMT markers, including E-cadherin, N-cadherin, β-catenin, γ-catenin, fibronectin, matrix metalloproteinase (MMP)-2, MMP-9, Slug, Snail, TWIST, vimentin, ZEB1, and ZEB2, in TUR specimens obtained from 161 consecutive patients with NMIUCB were measured by immunohistochemical staining.

RESULTS

Of these 13 markers, significant differences in the incidence of intravesical recurrence were noted according to expression levels of E-cadherin, N-cadherin, MMP-2, MMP-9, and TWIST. Univariate analysis also identified expression levels of E-cadherin, N-cadherin, MMP-2, MMP-9 and TWIST, in addition to the tumor size, pathological T category, and concomitant carcinoma in situ, as significant predictors of intravesical recurrence-free survival. Of these significant factors, expression levels of E-cadherin, MMP-9, and TWIST; tumor size; and concomitant carcinoma in situ appeared to be independently associated with intravesical recurrence-free survival on multivariate analysis. Furthermore, there were significant differences in recurrence-free survival according to positive numbers of these 5 independent risk factors (i.e., positive for 0 or 1 factor vs. positive for 2 factors vs. positive for 3 or more factors).

CONCLUSIONS

Consideration of expression levels of EMT-associated markers in TUR specimens, in addition to conventional prognostic parameters, would contribute to the accurate prediction of intravesical recurrence following TUR for NMIUCB.

Macrophage colony-stimulating factor and cancer: a review

Tumor growth is influenced by a wide variety of external and internal factors. One of the most important mediators of tumor development is our immune system. The nonstop surveillance of the immune system was originally expected to clear the transformed cells from the body and guard against the development of tumor. But contradictory evidences are reported to show the involvement of immune system in supporting the growth and spread of tumor. Tumor infiltrating immune cells, in addition to harboring immunosuppressive activities, also promote angiogenesis and metastasis of tumor. Many growth factors and cytokines are involved in shaping this complex immune microenvironment of the tumor. Macrophage colony-stimulating factor (MCSF) is one such growth factor which is overexpressed in many tumors. In this review, we summarize the basic biology of MCSF, its role in cancer and discuss the involvement of tumor-associated macrophages (TAMs) in tumor development.

Epidermal growth factor receptor expression in canine transitional cell carcinoma

Transitional cell carcinoma (TCC), a urinary bladder tumor with high mortality, is encountered commonly in dogs. Whereas overexpression of epidermal growth factor receptor (EGFR) is associated with development of human urinary bladder cancer, information on EGFR expression in canine TCC is lacking. In this study, EGFR protein and mRNA expression in canine normal bladder (n=5), polypoid cystitis (n=5) and TCC (n=25) were examined by immunohistochemistry and real-time polymerase chain reaction. EGFR protein expression was significantly higher in TCC than that in normal healthy bladder (P<0.001) and polypoid cystitis (P<0.005). High EGFR protein expression was significantly (P<0.01) associated with TCC with a sensitivity of 72% and specificity of 100%. Comparative analysis of protein and mRNA expression levels in TCC showed significant positive correlation (r=0.88, P<0.05) between mRNA and protein expression. These findings suggest that intense expression of EGFR protein could be used as a marker to help canine TCC diagnosis.