Retracted: MicroRNA-133a inhibits gastric cancer cells growth,migration, and epithelial-mesenchymal transition process by targeting presenilin 1

Gastric cancer (GC) is one of the most common malignancies and a leading cause of cancer-related death worldwide. Accumulating evidence reported that microRNA (miR)-133a was involved in GC. This study aimed to investigate the function and mechanism of miR-133a in the development and progression of GC. The expression of miR-133a and presenilin 1 (PSEN1) in two GC cell lines, SGC-7901 and BGC-823, were inhibited and overexpressed by transient transfections. Thereafter, cell viability, migration, and apoptosis were measured by trypan blue exclusion assay, transwell migration assay, and flow cytometry assay, respectively. Dual-luciferase reporter assay was conducted to verify whether PSEN1 was a direct target of miR-133a. Furthermore, quantitative real-time polymerase chain reaction and Western blot analysis were mainly performed to assess the expression changes of epithelial-mesenchymal transition (EMT)-associated proteins, apoptosis-related proteins, and Notch pathway proteins. MiR-133a inhibitor significantly increased cell viability and migration, while miR-133a mimic decreased cell viability, migration, and induced apoptosis. miR-133a suppression accelerated transforming growth factor-β1 (TGF-β1)-induce EMT, as evidenced by upregulation of E-cadherin, and downregulation of N-cadherin, vimentin, and Slug. Of contrast, miR-133a overexpression blocked TGF-β1-induce EMT by altering these factors. PSEN1 was a direct target of miR-133a, and suppression of PSEN1 abolished the promoting functions of miR-133 suppression on cell growth and metastasis. Moreover, PSEN1 inhibition decreased Notch 1, Notch 2, and Notch 3 protein expressions. This study demonstrates an antigrowth and antimetastasis role of miR-133a in GC cells. Additionally, miR-133a acts as a tumor suppressor may be via targeting PSEN1.     

Oleuropein inhibits migration ability through suppression of epithelial-mesenchymal transition and synergistically enhances doxorubicin-mediated apoptosis in MCF-7 cells

Distinct metastasis is one of the main causes of breast cancer (BC)-related mortality and epithelial-mesenchymal transition (EMT) is a primary step in metastasis dissemination. On the other hand, doxorubicin (DOX) is an effective chemotherapeutic agent against BC; unfortunately, its clinical use is limited by dose-dependent side effects. Therefore, extensive efforts have been dedicated to suppressing metastasis of BC and also to overcome DOX side effects together with keeping its antitumor efficacy. Studies supported the role of oleuropein (OLEU) in reducing DOX-induced side effects besides its antitumor actions. In this study, the antimigratory effect of OLEU was assessed and real-time PCR (RT-PCR) was used to detect OLEU effect on the expression level of EMT markers, in MCF-7 cells. The cytotoxic effect of OLEU and DOX was assessed by MTT assay, whereas the ratio of apoptosis was investigated by flow cytometry. The results showed that migration ability of MCF-7 cells remarkably decreased in OLEU treated group and RT-PCR results showed that OLEU may exert its antimigratory action by suppressing EMT through downregulation of sirtuin1 (SIRT1). Also, the results indicated that both OLEU and DOX were cytotoxic to MCF-7 cells, whereas DOX-OLEU cotreatment led to additive cytotoxicity and apoptosis rate. This study provides evidence regarding the suppressive role of OLEU on MCF-7 cells migration ability through suppression of EMT, and for the first time, it was proposed that SIRT1 downregulation can be involved in the OLEU antimigratory effect. Also, the findings demonstrated that OLEU can reduce DOX-induced side effects by reducing its effective dose.     

Esculentoside H inhibits colon cancer cell migration and growth through suppression of MMP-9 gene expression via NF-kB signaling pathway

A water-soluble saponin, Esculentoside H (EsH), 3-O-(O-β-d -glucopyranosyl-(1→4)-β-d -xylopyranosyl)-28-β-d -glucopyranosylphytolaccagenin has been isolated and purified from the root extract of perennial plant Phytolacca esculenta. EsH is known to be an anticancer compound, having a capacity for TNF-α release. However, the effects of EsH on migration and growth in tumor cells have not yet been reported. In the current study, the suppressive effects of EsH on phorbol 12-myristate 13-acetate (PMA)-induced cell migration were examined in murine colon cancer CT26 cells and human colon cancer HCT116 cells. Interestingly, the transwell assay and wound healing show that EsH suppresses the PMA-induced migration and growth potential of HCT116 and CT26 colon cancer cells, respectively. EsH dose-dependently suppressed matrix metalloproteinases-9 (MMP-9) expression that was upregulated upon PMA treatment in messenger RNA levels and protein secretion. Since the expression of MMP-9 is correlated with nuclear factor-κB (NF-κB) signaling, it has been examined whether EsH inhibits PMA-induced IκB phosphorylation that leads to the suppression of NK-κB nuclear translocation. EsH repressed the phosphorylation level of JNK, but not extracellular signal-regulated kinase and p38 signaling when the cells were treated with PMA. Overall, these results demonstrated that EsH could suppress cancer migration through blockage of the JNK1/2 and NF-κB signaling-mediated MMP-9 expression.     

lncRNA MIR503HG functioned as a tumor suppressor and inhibited cell proliferation,metastasis and epithelial-mesenchymal transition in bladder cancer

Bladder cancer is the most common malignancy with high recurrence. Currently, the long noncoding RNAs (lncRNAs) have been suggested to play vital roles in the pathogenesis of bladder cancer. The present study investigated the role of lncRNA MIR503 host gene (MIR503HG) in the pathogenesis of bladder cancer by using both in vitro and in vivo functional assays. The expression of MIR503HG was downregulated in bladder cancer tissues and cell lines. Low expression of MIR503HG was associated with advanced tumor stage, advanced histological grade, and lymph node metastasis. Ectopic expression of MIR503HG inhibited cell proliferation, cell growth, cell invasion, and migration, and also promoted cell apoptosis and inhibited cell cycle progression in SW780 cells. In parallel, T24 cells were used for loss-of-function studies. Knockdown of MIR503HG promoted the cancer cell proliferation and increased the migration and invasion abilities of T24 cells. In addition, knockdown of MIR503HG reduced the cell apoptotic rate in cancer cells and promoted cell cycle progression. Furthermore, MIR503HG overexpression decreased the epithelial-mesenchymal transition-related mRNA and protein levels of ZEB1, Snail, N-cadherin, and vimentin, with an increase in E-cadherin level. Consistently, knockdown of MIR503HG showed the opposite effects. In vivo xenograft, nude mice results showed that overexpression of MIR503HG suppressed the tumor growth and tumor metastasis. In conclusion, our results identified a novel lncRNA MIR503HG that exhibited significant antiproliferation, antimigration/invasion effects on bladder cancer cells both in vitro and in vivo, which may hold a therapeutic promise to treat bladder cancer.     

Overexpression of microRNA-190 inhibits migration,invasion, epithelial-mesenchymal transition,and angiogenesis through suppression of protein kinase B-extracellular signal-regulated kinase signaling pathway via binding to stanniocalicin 2 in breast cancer

Breast cancer (BC) is known as the most deadly cancer among females, worldwide. Despite the research advances in this regard, effective diagnosis and treatment still have a long way to go. In this study, our stance was to investigate the regulatory mechanism of miR-190 on epithelial-mesenchymal transition (EMT) and angiogenesis via mediation of protein kinase B (AKT)-extracellular signal-regulated kinase (ERK) signaling pathway by targeting stanniocalicin 2 (STC2) in BC. The BC gene chip was retrieved with differentially expressed genes (DEGs) obtained. MDA-MB-231 and T47D cell lines were selected and separately introduced with miR-190 inhibitors, activators, and small interfering RNAs with the intent of exploring the regulatory functions that miR-190 has shown while governing STC2 in BC. The regulatory effect of miR-190 on cell proliferation, migration, invasion, and angiogenesis was evaluated, followed by determination of AKT-ERK signaling pathway-related factors, EMT-related factors, and angiogenesis-related factors. The xenograft tumor of nude mice was also implemented for determining the change of tumor after transfection. The GSE26910 gene chip was obtained with STC2 being selected as the potential DEG. STC2 was the target gene of miR-190. The results showed that cells introduced with the miR-190 activators along with small interfering RNA-STC2 inhibited proliferation, invasion, migration, angiogenesis, as well as EMT. Moreover, the in vivo experiment also went on to confirm that the tumor volume had significantly increased in the nude mice along with an elevated expression of miR-190. Collectively, the findings suggested that overexpression of miR-190 inhibited EMT and angiogenesis by inactivating AKT-ERK signaling pathway via STC2 in BC.     

siRNA‐induced CD44 knockdown suppresses the proliferation and invasion of colorectal cancer stem cells through inhibiting epithelial–mesenchymal transition

CD44 has shown prognostic values and promising therapeutic potential in multiple human cancers; however, the effects of CD44 silencing on biological behaviors of cancer stem cells (CSCs) have not been fully understood in colorectal cancer. To examine the contribution of siRNA‐induced knockdown of CD44 to the biological features of colorectal CSCs, colorectal CSCs HCT116‐CSCs were generated, and CD44 was knocked down in HCT116‐CSCs using siRNA. The proliferation, migration and invasion of HCT116‐CSCs were measured, and apoptosis and cell‐cycle analyses were performed. The sensitivity of HCT116‐CSCs to oxaliplatin was tested, and xenograft tumor growth assay was performed to examine the role of CD44 in HCT116‐CSCs tumorigenesis in vivo. In addition, the expression of epithelial–mesenchymal transition (EMT) markers E‐cadherin, N‐cadherin and vimentin was quantified. siRNA‐induced knockdown of CD44 was found to inhibit the proliferation, migration and invasion, induce apoptosis, promote cell‐cycle arrest at the G1/G0 phase and increase the sensitivity of HCT116‐CSCs to oxaliplatin in HCT116‐CSCs, and knockdown of CD44 suppressed in vivo tumorigenesis and intrapulmonary metastasis of HCT116‐CSCs. Moreover, silencing CD44 resulted in EMT inhibition. Our findings demonstrate that siRNA‐induced CD44 knockdown suppresses the proliferation, invasion and in vivo tumorigenesis and metastasis of colorectal CSCs by inhibiting EMT.     

MicroRNA‐300 promotes apoptosis and inhibits proliferation,migration, invasion and epithelial‐mesenchymal transition via the Wnt/β‐catenin signaling pathway by targeting CUL4B in pancreatic cancer cells

The study aims to verify the hypothesis that up‐regulation of microRNA‐300 (miR‐300) targeting CUL4B promotes apoptosis and suppresses proliferation, migration, invasion, and epithelial‐mesenchymal transition (EMT) of pancreatic cancer cells by regulating the Wnt/β‐catenin signaling pathway. Pancreatic cancer tissues and adjacent tissues were collected from 110 pancreatic cancer patients. Expression of miR‐300, CUL4B, Wnt, β‐catenin, E‐cadherin, N‐cadherin, Snail, GSK‐3β, and CyclinD1 were detected using qRT‐PCR and Western blot. CFPAC‐1, Capan‐1, and PANC‐1 were classified into blank, negative control (NC), miR‐300 mimics, miR‐300 inhibitors, siRNA‐CUL4B, and miR‐300 inhibitors + siRNA‐CUL4B groups. The proliferation, migration, invasion abilities, the cell cycle distribution, and apoptosis rates were measured in CCK‐8 and Transwell assays. Pancreatic cancer tissues showed increased CUL4B expression but decreased miR‐300 expression. When miR‐300 was lowly expressed, CUL4B was upregulated which in‐turn activated the Wnt/β‐catenin pathway to protect the β‐catenin expression and thus induce EMT. When miR‐300 was highly expressed, CUL4B was downregulated which in‐turn inhibited the Wnt/β‐catenin pathway to prevent EMT. Weakened cell migration and invasion abilities and enhanced apoptosis were observed in the CUL4B group. The miR‐300 inhibitors group exhibited an evident increase in growth rate accompanied the largest tumor volume. Smaller tumor volume and slower growth rate were observed in the miR‐300 mimics and siRNA‐CUL4B group. Our study concludes that lowly expressed miR‐300 may contribute to highly expressed CUL4B activating the Wnt/β‐catenin signaling pathway and further stimulating EMT, thus promoting proliferation and migration but suppressing apoptosis of pancreatic cancer cells.