MiR-204 inhibits human NSCLC metastasis through suppression of NUAK1

BACKGROUND

Lung cancer is a leading cause of cancer-related mortality worldwide and non-small-cell lung carcinoma (NSCLC) is responsible for almost 80% of lung cancer-related deaths. Identifying novel molecules that can repress the invasiveness and metastasis of lung cancer will facilitate the development of new antilung cancer strategies. The aim of this study is to determine the roles of NUAK1 (a downstream of Akt) and miR-204 in the invasiveness and metastasis of NSCLC and to reveal the correlation between NUAK1 and miR-204.

METHODS

The expression of NUAK1 in primary human NSCLC tissues was evaluated by immunohistochemistry. Real-time PCR was employed to measure the expression level of miR-204. The effect of NUAK1 and miR204 on the prognosis of NSCLC patients was evaluated by log-rank test. The siRNA transfection was used to manipulate the expression levels of NUAK1 and miR204 in cancer cells. Chemotaxis assay, Scratch assay, and Matrigel invasion assay were performed to evaluate the migration and invasion of cells. Cellular F-actin measurement was used to measure F-actin polymerisation in lung cancer cells. Western blot was used to detect the expression levels of corresponding proteins. The Luciferase assay and RNA immunoprecipitation were used to confirm the actual binding site of miR-204 to 3'UTR of NUAK1.

RESULTS

Increased expression of NUAK1 is correlated with the invasiveness and metastasis of human NSCLC. Knockdown of NUAK1 inhibited cell migration and invasion. In addition, this study showed that NUAK1 influenced mTOR phosphorylation and induced the phosphorylation of p70S6K1 and eukaryotic initiation factor 4E-binding protein1 (4E-BP1), two downstream targets of mTOR in NSCLC cells. At the same time, decreased expression of miR-204 promoted NSCLC progression and, contrarily, manipulated upregulation of miR-204-inhibited cell migration and invasion. There is clinical relevance between miR-204 downregulation and NUAK1 upregulation in human NSCLC. Furthermore, we found that miR-204 inhibited NSCLC tumour invasion by directly targeting and downregulating NUAK1 expression. Finally, our data suggested that the downregulation of miR-204 was due to hypermethylation of its promoter region.

CONCLUSIONS

Our results indicate that NUAK1 is excessively expressed in NSCLC and plays important roles in NSCLC invasion. The miR-204 acts as a tumour suppressor by inhibiting NUAK1 expression in NSCLC. Both NUAK1 and miR-204 may serve as potential targets of NSCLC therapy.

PTTG1 promotes migration and invasion of human non-small cell lung cancer cells and is modulated by miR-186

Deeper mechanistic understanding of non-small cell lung cancer (NSCLC), a leading cause of total cancer-related deaths, may facilitate the establishment of more effective therapeutic strategies. In this study, pituitary tumor transforming gene (PTTG1) expression was associated with lymph node and distant metastasis in patients with NSCLC and was correlated with patient survival. Reduction of PTTG1 by small interfering RNA (siRNA) inhibits the migration and invasion of NSCLC cells by mediating matrix metalloproteinases expression. To the best of our knowledge, this study is the first to report that PTTG1 promotes epidermal growth factor (EGF) induced the phosphorylation of LIN-11, Isl1 and MEC-3 protein domain kinase and cofilin, a critical step in cofilin recycling and actin polymerization. Additionally, EGF-induced Akt phosphorylation was suppressed through knockdown of PTTG1. Interestingly, miR-186 can modulate PTTG1 protein expression. As observed from the animal experiment in this study, knockdown of PTTG1 through siRNA and overexpression of miR-186 inhibited invasive activity of NSCLC cells toward the SCID mice lung. In summary, our in vitro and in vivo results indicate that PTTG1 modulated by miR-186 has an important function in NSCLC invasion/metastasis. This study identified both PTTG1 and miR-186 as potential anti-invasion targets for therapeutic intervention in NSCLC.

RAGE-binding S100A8/A9 promotes the migration and invasion of human breast cancer cells through actin polymerization and epithelial-mesenchymal transition

S100A8/A9 proteins are members of EF-hand calcium-binding proteins secreted by neutrophils and activated monocytes. S100A8/A9 has cell growth-promoting activity at low concentrations by binding to the receptor for advanced glycation end products (RAGE). In this study, we report for the first time that S100A8/A9 promoted the invasion of breast cancer cells depending on RAGE. In addition, RAGE binding to S100A8/A9 promoted the phosphorylation of LIN-11, Isl1, and MEC-3 protein domain kinase, as well as cofilin. This phosphorylation is a critical step in cofilin recycling and actin polymerization. Interestingly, RAGE binding to S100A8/A9 enhanced cell mesenchymal properties and induced epithelial-mesenchymal transition. Mechanistically, RAGE binding to S100A8/A9 stabilized Snail through the NF-κB signaling pathway. Based on these observations, RAGE expression in breast cancer cells was associated with lymph node and distant metastases in patients with invasive ductal carcinoma. Moreover, RAGE binding to S100A8/A9 promoted lung metastasis in vivo. In summary, our in vitro and in vivo results indicated that RAGE binding to S100A8/A9 played an important role in breast cancer invasion/metastasis. This study identified both RAGE and S100A8/A9 as potential anti-invasion targets for therapeutic intervention in breast cancer.

Reduction of Akt2 inhibits migration and invasion of glioma cells

Malignant gliomas have a tendency to invade diffusely into surrounding healthy brain tissues, thereby precluding their successful surgical removal. The serine/threonine kinase Akt2 is well known as an important regulator of cell survival and growth. In this study, we show that siRNA-mediated depletion of Akt2 inhibited migration and invasion of glioma cells. In addition, we demonstrate the mechanisms by which Akt2 functions to promote cell migration and invasion. Phosphorylation of cofilin, a critical step of actin polymerization, and phosphorylation of Girdin, essential for the integrity of the actin cytoskeleton and cell migration, were impaired. Furthermore, epidermal growth factor-induced ACAP1 phosphorylation and integrin beta1 phosphorylation were also blocked, consistent with defects in adhesion. Thus, Akt2 regulates both cell adhesion and cytoskeleton rearrangement during migration. Decreased MMP-9 expression in Akt2 knocked-down glioma cells was subsequently confirmed by Western blotting, consistent with the decreased invasion in vitro and in vivo. These results suggest that Akt2 contributes to glioma cells migration and invasion by regulating the formation of cytoskeleton, influencing adhesion and increasing expression of MMP-9. Our immunohistochemistry results by using human gliomas tissue sections also indicated that Akt2 expression was closely related with the malignancy of gliomas. This is coincident with our in vivo and in vitro results from cell lines. All of these results indicate that Akt2 is a critical factor in gliomas invasion. This study identifies that Akt2 is a potentially antiinvasion target for therapeutic intervention in gliomas.

Reduction of protein kinase C zeta inhibits migration and invasion of human glioblastoma cells

Glioblastomas are the most aggressive forms of primary brain tumors with their tendency to invade surrounding healthy brain tissues, rendering them largely incurable. In this report, we used small-interference RNA technology to knock down the expression of protein kinase C (PKC) zeta, which resulted in specific and massive impairment of glioblastoma cell migration and invasion. We also explained the fundamental molecular processes of glioblastoma migration and invasion in which PKCzeta is a participant. The silence of PKCzeta expression likewise impaired the phosphorylation of LIN-11, Isl1 and MEC-3 protein domain kinase (LIMK) and cofilin, which is a critical step in cofilin recycling and actin polymerization. Consistent with the defects in cell adhesion, phosphorylation of integrin beta1 was also dampened. Therefore, PKCzeta regulated both cytoskeleton rearrangement and cell adhesion, which contributed to cell migration. Additionally, there was down-regulation of matrix metalloprotease-9 expression in siPKCzeta/LN-229 cells, which coincided with decreased invasion both in vitro and in vivo. These results indicate that PKCzeta is involved in the control of glioblastoma cell migration and invasion by regulating the cytoskeleton rearrangement, cell adhesion, and matrix metalloprotease-9 expression. Collectively, these findings suggest that PKCzeta is a potential therapeutic target for glioblastoma infiltration.

Cancer-associated fibroblast-derived exosomal miR-18b promotes breast cancer invasion and metastasis by regulating TCEAL7

Studies have shown that cancer-associated fibroblasts (CAFs) play an irreplaceable role in the occurrence and development of tumors. Therefore, exploring the action and mechanism of CAFs on tumor cells is particularly important. In this study, we compared the effects of CAFs-derived exosomes and normal fibroblasts (NFs)-derived exosomes on breast cancer cells migration and invasion. The results showed that exosomes from both CAFs and NFs could enter into breast cancer cells and CAFs-derived exosomes had a more enhancing effect on breast cancer cells migration and invasion than NFs-derived exosomes. Furthermore, microRNA (miR)-18b was upregulated in CAFs-derived exosomes, and CAFs-derived exosomes miR-18b can promote breast cancer cell migration and metastasis by specifically binding to the 3'UTR of Transcription Elongation Factor A Like 7 (TCEAL7). The miR-18b-TCEAL7 pathway promotes nuclear Snail ectopic activation by activating nuclear factor-kappa B (NF-κB), thereby inducing epithelial-mesenchymal transition (EMT) and promoting cell invasion and metastasis. Moreover, CAFs-derived exosomes miR-18b could promote mouse xenograft model tumor metastasis. Overall, our findings suggest that CAFs-derived exosomes miR-18b promote nuclear Snail ectopic by targeting TCEAL7 to activate the NF-κB pathway, thereby inducing EMT, invasion, and metastasis of breast cancer. Targeting CAFs-derived exosome miR-18b may be a potential treatment option to overcome breast cancer progression.

The tumor suppressor gene RhoBTB1 is a novel target of miR-31 in human colon cancer

miRNAs are a class of endogenous non-coding RNA, which can regulate downstream target genes through binding to the 3'UTR of those genes. Numerous studies have indicated that abnormal expression of miRNAs is implicated in tumor development. Aberrant expression of miR-31 has been found in various cancers, including colorectal cancer. Here, we show that miR-31 is upregulated in human colon cancer tissues and cell lines, and that repression of miR-31 inhibited colon cancer cell proliferation and colony formation in soft agarose. To further elucidate the mechanism underlying the role of miR-31 in promoting colon cancer, we used online miRNA target prediction databases and found that the tumor suppressor RhoTBT1 may be a target of miR-31. Imunohistochemistry assay revealed that RhoBTB1 was significantly decreased in HT29 cells. In addition, ectopic expression of miR-31 reduced RhoBTB1 in the colon cancer cell line HT29. The results suggested that suppression of RhoBTB1 may be responsible for colon tumorigenesis, which was inhibited directly by miR-31. The results of MTT and soft agarose colony-formation assays showed that knockdown of RhoBTB1 by RNAi induced cell proliferation, and colony formation in soft agarose, which mimicked the function of miR-31. This further suggested that suppression of RhoBTB1 was responsible for colon tumorigenesis. In conclusion, we found that miR-31 acts as an oncogene in colon cancer and identified RhoBTB1 as a new target of miR-31 further study demonstrated that miR-31 contributed to the development of colon cancer at least partly by targeting RhoBTB1.

Nir1 promotes invasion of breast cancer cells by binding to chemokine (C-C motif) ligand 18 through the PI3K/Akt/GSK3β/Snail signalling pathway

Chemokine (C-C motif) ligand 18 (CCL18), which is derived from tumour-associated macrophages (TAMs), plays a critical role in promoting breast cancer metastasis via its receptor, PYK2 N-terminal domain interacting receptor 1 (Nir1). However, the molecular mechanism by which Nir1 promotes breast cancer metastasis by binding to CCL18 remains elusive. In this study, Nir1 expression was associated with lymph node and distant metastasis in patients with invasive ductal carcinoma. For the first time, we report that Nir1 binding to CCL18 promotes the phosphorylation of Akt, LIN-11, Isl1 and MEC-3 protein domain kinase (LIMK), and cofilin, which is a critical step in cofilin recycling and actin polymerisation. Interestingly, Nir1 binding to CCL18 can enhance cell mesenchymal properties and induce epithelial-mesenchymal transition (EMT). Mechanistically, Nir1 binding to CCL18 stabilises Snail via the Akt/GSK3β signalling pathway. In support of these observations, Nir1 binding to CCL18 promoted lung metastasis and LY294002 could inhibit it in vivo. In summary, our in vitro and in vivo results indicate that Nir1 binding to CCL18 plays an important role in breast cancer invasion/metastasis. This study identified both Nir1 and CCL18 as potential anti-invasion targets for therapeutic intervention in breast cancer.

Autocrine IL-8 promotes F-actin polymerization and mediate mesenchymal transition via ELMO1-NF-κB-Snail signaling in glioma

Glioma is the most common form of primary malignant brain cancers. Tumor cell invasiveness is a critical challenge in the clinical management of glioma patients. The invasive biological feature of glioma cell is stimulated by both autocrine and paracrine factors including chemokine IL-8. In this study, we report that the production of IL-8 is higher in glioma tissues and cells than adjacent nontumor tissues (ANT) and normal glial cells. Autocrine IL-8 can increase the invasive ability of glioma cells by binding to CXCR1. In addition, high expression of IL-8 indicates poor prognosis of glioma patients. Furthermore, IL-8 is capable of modulating cell migration and invasion by regulating the activation of RAC1 which resulted in cytoskeletal reorganisation in an ELMO1 dependent manner. Finally, we found that IL-8 could enhance mesenchymal transition(MT) of glioma cells by activating ELMO1-NF-κB-Snail signaling. Our data indicate that IL-8 autocrine is responsible for the invasive phenotype of glioma and IL-8 may be a useful prognostic marker for glioma and novel therapeutic target for glioma invasion intervention.

CC chemokine ligand 18(CCL18) promotes migration and invasion of lung cancer cells by binding to Nir1 through Nir1-ELMO1/DOC180 signaling pathway

Non-small cell lung cancer (NSCLC) comprises nearly 80% of lung cancers and the poor prognosis is due to its high invasiveness and metastasis. CC chemokine ligand 18 (CCL18) is predominantly secreted by M2-tumor associated macrophages (TAMs) and promotes malignant behaviors of various human cancer types. In this study, we report that the high expression of CCL18 in TAMs of NSCLC tissues and increased expression of CCL18 in TAMs is correlated with the lymph node metastasis, distant metastasis, and poor prognosis NSCLC patients. CCL18 can increase the invasive ability of NSCLC cells by binding to its receptor Nir1. In addition, CCL18 is capable of modulating cell migration and invasion by regulating the activation of RAC1 which resulted in cytoskeleton reorganization in an ELMO1 dependent manner. Furthermore, we found that CCL18 could enhance adhesion of NSCLC cells via activating ELMO1-integrin β1 signaling. Thus, CCL18 and its downstream molecules may be used as targets to develop novel NSCLC therapy. © 2016 Wiley Periodicals, Inc.

SATB1 expression is associated with biologic behavior in colorectal carcinoma in vitro and in vivo

There is increasing evidence that Special AT-rich sequence-binding protein 1 (SATB1) is aberrantly expressed in several cancers and is correlated with clinicopathologic parameters in these tumors. In this study, we showed over-expression of SATB1 in 80 cases of colorectal cancer and in 3 colorectal cancer cell lines and found expression levels were strongly associated with tumor differentiation and stage. Expression levels of SATB1 protein were higher in poorly-differentiated as compared with well-differentiated cell lines, and both quantity and distribution patterns of SATB1 were associated with tumor differentiation and pTNM stage. Strikingly, we further investigated the effect of down regulation of SATB1 expression on malignant phenotypic features in colorectal cancer cells in vitro, and showed that SABT1 down-regulation negatively affected growth potential, anchorage-independent colony formation and cancer cell invasion, and resulted in increased apoptosis. SATB1 expression was positively associated with the expression of various biological and genetic markers, including Cyclin D1, MMP-2, NF-κB, and PCNA, and was associated with loss of APC and BRAF^V600E. These findings suggest that SATB1 is involved in the carcinogenesis, development and progression of colorectal cancer.

MiR-486-5p inhibits IL-22-induced epithelial-mesenchymal transition of breast cancer cell by repressing Dock1

Epithelial-mesenchymal transition (EMT) is one of important steps that lead to cancer metastasis. Interleukin-22 (IL-22) is a T helper 17 (Th17) cells-secreted cytokine, it can promote invasion and metastasis of many cancers. MiR-486-5p is a microRNA that known to function as a tumor suppressor, and bioinformatics analysis predicts that Dock-1 has a binding site of miR-486-5p. In current research, we examined the relative expression levels of miR-486-5p and Dock-1 in 80 pairs of breast cancer tissues and corresponding adjacent normal tissues, also the effects of modifying their levels in cultured cells. We illustrated that IL-22 and Dock1 promote the invasion, metastasis, and EMT of breast cancer using Transwell invasion assay, western blot and immunofluorescence. MiR-486-5p directly bound the Dock1 mRNA 3' untranslated region and inhibited IL-22-induced EMT of breast cancer cells via the Dock1/NF-κB/Snail signaling pathway. Dock1 overexpression reversed the effect caused by the overexpression of miR-486-5p. Overexpression of miR-486-5p or downregulation of Dock1 reduced pulmonary metastasis in mice. This study provided insight into a potential mechanism where miRNAs regulate breast cancer metastasis and provided a novel therapeutic target for breast cancer treatment.

Long non-coding RNA XIST exerts oncogenic functions in pancreatic cancer via miR-34a-5p

Long non-coding RNAs (lncRNAs) have been implicated in the occurrence and progression of multiple cancers. In the present study, we investigated the role of lncRNA X inactive-specific transcript (XIST) in the development and progression of pancreatic cancer (PC). Firstly, we found that lncRNA XIST was markedly upregulated in PC tissues and PC cell lines, respectively. Overexpression of XIST significantly promoted the proliferation, migration and invasion, and suppressed cell apoptosis of BxPC-3 cells; knockdown of XIST significantly inhibited the proliferation, migration and invasion, and accelerated cell apoptosis of PANC-1 cells. Furthermore, BxPC-3 and PANC-1 cells transfected with different vectors were injected subcutaneously into nude mice to explore tumor formation. We found that XIST promoted tumor formation in vivo. Subsequently, we found that microRNA-34a-5p (miR‑34a-5p) was downregulated in PC tissues, and predicted a poor prognosis in PC patients. In addition, the results indicated that miR-34a-5p is a target gene of XIST and was significantly negatively correlated with XIST. More importantly, we found that miR-34a-5p rescued the facilitation of malignant behavior mediated by XIST. These results indicated that XIST and miR-34a-5p may be potential effective therapeutic targets for PC.

MiR-429 suppresses proliferation and invasion of breast cancer via inhibiting the Wnt/β-catenin signaling pathway

Background

microRNAs (miRNAs) have been verified as molecular targets for regulating tumor proliferation, invasion, and metastasis in tumor progression. However, the relationship between miRNAs and cellular energy metabolism in breast cancer still needs to be clarified. This study aimed to investigate the role of miR‐429 in breast cancer progression.

Methods

Bioinformatic analyses were employed to detect the relationship between miR‐429 and cancer‐related signaling pathways. We used a Kaplan‐Meier curve to analyze survival rate in patients with high or low expression of miR‐429. We used real‐time quantitative PCR (RT‐qPCR) to detect the expression of miR‐429 in different cell lines. Sh‐con, over‐miR‐429, miR‐429 inhibitor, and sh‐inhibitor control were transfected. Colony formation and EDU assay were used to detect the proliferation of transfected cells. Wound healing and transwell assays were performed to detect the mobility and invasion ability of transfected cells. Western blot assay was used to detect relative protein expression in transfected cells and different tissues. Bioinformatic analyses were conducted to detect the target proteins expression in different breast cancer databases. Dual luciferase reporter assay was used to confirm the binding site between miR‐429 and fibronectin 1 (FN1).

Results

The results of our study indicate that MiR‐429 and its target genes are associated with cancer‐related signaling pathways and that higher miR‐429 expression corresponds with a better prognosis. When miR‐429 was overexpressed, the proliferation, invasion of MDA‐MB‐231 were inhibited. MiR‐429 was able to suppress the Wnt/β‐catenin signaling pathway, and FN1 overexpression could rescue the influence of over‐miR‐429.

Conclusions

The results of our study suggest that miR‐429 suppresses the proliferation and invasion of breast cancer via inhibiting the Wnt/β‐catenin signaling pathway.

Pivotal Advance: PKCzeta is required for migration of macrophages

The crosstalk, mediated by chemoattractants, between cancer cells and tumor-associated macrophages, plays an important role in tumor invasion and metastasis. Our previous study reported that atypical protein kinase C zeta (PKCzeta) regulates epidermal growth factor-induced chemotaxis of human breast cancer cells. In this study, we investigated the role of PKCzeta in CSF-1-induced chemotaxis of macrophages. Knockdown of PKCzeta by small interference RNA impaired CSF-1-induced chemotaxis of human acute monocytic leukemia cell line THP-1, which was probably a result of a decrease in CSF-1-induced phosphorylation of LIN-11, Is11, and MEC-3 protein domain kinase (LIMK)/cofilin and actin polymerization. Furthermore, silencing PKCzeta expression also impaired migration of mouse peritoneal macrophages. Scratch analysis indicated that PKCzeta was required for macrophage migration. Therefore, PKCzeta is required for CSF-1-induced chemotaxis of macrophages. Blocking activation of PKCzeta will be a novel strategy to inhibit cancer metastasis by blocking migration of cancer cells and macrophages.

Gab2 expression in glioma and its implications for tumor invasion

Gliomas are characterized by high invasiveness and poor prognosis. Better understanding of the mechanism of invasion in glioma cells is essential to the design of effective therapy. Recently Grb2-associated binder 2 (Gab2), a member of the DOS/Gab family of scaffolding adapters, has been reported to play important roles in the development and progression of human cancers. However, it is not known whether Gab2 has any role in the migration and invasion of gliomas. This study attempts to investigate the association between Gab2 expression and progression of gliomas and the molecular mechanism of Gab2 in the glioma cell invasion. Methods. The expression of Gab2 in pairs of matched glioma tissues and their normal brain tissues was detected by Western blot. Immunohistochemistry was applied to evaluate the expression of Gab2 in 163 cases of histologically diagnosed gliomas. The invasive character of Gab2 decreased glioma cells and control glioma cells were investigated in vitro and in vivo in SCID mice brain. Results. Gab2 is found to be high expressed in gliomas and a subset of cancer cell lines. Statistical analysis suggested that the up-regulation of Gab2 correlated with the WHO grade of gliomas (p < 0.01) and that patients with high Gab2 expression levels exhibited shorter survival time (p < 0.01). In an animal experiment, knockdown of Gab2 through siRNA inhibited invasive ability of glioma cells into the brain of SCID mice. In cell research, reduction of Gab2 by siRNA inhibits the migration and invasion of glioma cells by mediating cytoskeleton rearrangement and MMPs expression. Additionally, IGF-1-induced pAkt and pmTOR phosphorylation was suppressed by the knockdown of Gab2. Conclusion. Gab2 may be a useful prognostic marker for gliomas and a novel therapeutic target for glioma invasion intervention.

Neuron-derived IgG protects dopaminergic neurons from insult by 6-OHDA and activates microglia through the FcγR I and TLR4 pathways

Oxidative and immune attacks from the environment or microglia have been implicated in the loss of dopaminergic neurons of Parkinson's disease. The role of IgG which is an important immunologic molecule in the process of Parkinson's disease has been unclear. Evidence suggests that IgG can be produced by neurons in addition to its traditionally recognized source B lymphocytes, but its function in neurons is poorly understood. In this study, extensive expression of neuron-derived IgG was demonstrated in dopaminergic neurons of human and rat mesencephalon. With an in vitro Parkinson's disease model, we found that neuron-derived IgG can improve the survival and reduce apoptosis of dopaminergic neurons induced by 6-hydroxydopamine toxicity, and also depress the release of NO from microglia triggered by 6-hydroxydopamine. Expression of TNF-α and IL-10 in microglia was elevated to protective levels by neuron-derived IgG at a physiologic level via the FcγR I and TLR4 pathways and microglial activation could be attenuated by IgG blocking. All these data suggested that neuron-derived IgG may exert a self-protective function by activating microglia properly, and IgG may be involved in maintaining immunity homeostasis in the central nervous system and serve as an active factor under pathological conditions such as Parkinson's disease.

miR-429 inhibits glioma invasion through BMK1 suppression

The purpose of this research was to examine the relationship between big mitogen-activated protein kinase 1 (BMK1) and miRNA miR-429 and to determine the effect of miR-429 on glioma invasiveness. Immunohistochemistry was used to evaluate BMK1 expression in glioma tissues. Real-time PCR was used to measure the expression of miR-429 and other RNAs. Western blot was used to detect the expression of BMK1 and other related proteins. Wound healing, Matrigel invasion, and chemotaxis assays were performed to detect the invasion and migration of glioma cell lines. The actual binding site of miR-429 to the 3' untranslated region of BMK1 was confirmed by luciferase assay and RNA immunoprecipitation. BMK1 expression was associated with the World Health Organization grading of glioma and inversely correlated with patient survival. Suppression of BMK1 inhibited the migration and invasion of glioma cells by interfering with mesenchymal transition. Additionally, hepatocyte growth factor-induced GSK3β phosphorylation was suppressed through BMK1 knockdown. Interestingly, our findings validated a novel role for miR-429 in suppressing the migration and invasion of glioma by directly inhibiting BMK1 expression. We also found that miR-429 expression in glioma cells and tissues was lower than that in normal cells and adjacent non-neoplastic tissues, and miR-429 overexpression inhibited invasive activity of glioma cells both in vitro and in vivo. Furthermore, our data validated that miR-429 downregulation was due to the hypermethylation of its promoter region. Our results indicated that BMK1 modulation by miR-429 has an important function in glioma invasion both in vitro and in vivo.

EBP50 inhibits the migration and invasion of human breast cancer cells via LIMK/cofilin and the PI3K/Akt/mTOR/MMP signaling pathway

The scaffold protein ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50, also known as NHERF1 or NHERF) inhibits epidermal growth factor (EGF)-induced breast cancer cell proliferation after 3 days by blocking EGF receptor (EGFR) phosphorylation. The loss of EBP50 stimulates EGFR activity and induces the appearance of epithelial-to-mesenchymal transition phenotypic features in biliary cancer cells. However, the involvement of EBP50 in breast cancer migration and invasion remains unknown. We report that EBP50 inhibits the migration and invasion of breast cancer cells by inhibiting the phosphorylation of LIN-11, Isl1, and MEC-3 protein domain kinase, as well as cofilin. This phosphorylation is a critical step in cofilin recycling and actin polymerization mediating cytoskeletal rearrangement. Additionally, EGF-induced phosphorylation of Akt and mTOR was suppressed by upregulation of EBP50. Our results indicate that EBP50 is significantly involved in breast cancer invasion/metastasis via LIMK/cofilin and the PI3K/Akt/mTOR/MMP signaling pathway.

Exosomal ncRNAs facilitate interactive 'dialogue' between tumor cells and tumor-associated macrophages

As a biological carrier, exosomes participate in the communication between various kinds of cells, and can mediate the interactive 'dialogue' between tumor cells and tumor-associated macrophages (TAMs). TAMs are the most abundant cell population in the tumor stroma and are an important part of the tumor immune microenvironment. Various stimulating factors in the tumor microenvironment influence the polarization of TAMs into multiple phenotypes, such as M1 and M2. It plays a dual role in tumor immunity by both promoting and inhibiting tumor growth. Exosome-encapsulated non-coding RNAs (ncRNAs) participate in the interactive 'dialogue' between exosome-mediated TAMs and tumor cells. Tumor-derived exosomal ncRNAs can promote macrophage polarization, whereas exosomal ncRNAs derived from TAMs can affect tumor proliferation, metastasis, angiogenesis, and chemotherapy resistance. The present review summarizes the dual effects of exosomal ncRNAs on tumor cells and TAMs, and discusses the application of exosomal ncRNAs as a potential diagnostic or prognostic marker and drug delivery system, to provide a new perspective and potential therapeutic drugs on targeting exosomes and macrophages in the treatment of tumors.

CCL18 promotes the invasion and metastasis of breast cancer through Annexin A2

Chemokine (C‑C motif) ligand 18 (CCL18) is derived from breast tumor‑associated macrophages (TAMs), which are primarily a macrophage subpopulation with an M2 phenotype. CCL18 binds to its receptor, PYK2 N‑terminal domain interacting receptor 1 (Nir1), and promotes tumor progression and metastasis by inducing epithelial‑mesenchymal transition (EMT) via the PI3K/Akt/GSK3β/Snail signaling pathway in breast cancer cells. Recent research shows that Annexin A2 (AnxA2) plays a significant role in the invasion, metastasis, angiogenesis, proliferation, F‑actin polymerization and multidrug resistance to chemotherapy of breast cancer. The present study aimed to elucidate the molecular mechanisms by which CCL18 promotes breast cancer progression through AnxA2 which are not fully understood. Western blot analysis showed that the expression of AnxA2 was upregulated in highly invasive breast cancer cell lines and invasive ductal carcinoma. Furthermore, through chemotaxis, scratch, Matrigel invasion, and spontaneous metastasis assays, it was demonstrated that AnxA2 enhanced the invasion of breast cancer cells and the metastasis of human breast cancer cells to lungs of SCID mice with CCL18 stimulation. Cellular F‑actin measurement assay showed that reduction of AnxA2 suppressed CCL18‑induced F‑actin polymerization though phosphorylation of integrin β1 in breast cancer cells. Immunofluorescence and western blot analysis revealed that AnxA2 promoted CCL18‑induced EMT via the PI3K/Akt/GSK3β/Snail signaling pathway, and LY294002 inhibited the phosphorylation of AnxA2 in vitro. In brief, AnxA2, as a downstream molecule of Nir 1 binding to CCL18, promotes invasion and metastasis by EMT through the PI3K/Akt/GSK3β/Snail signaling pathway in breast cancer. This study suggests that AnxA2 is a potential anti‑invasion/metastasis target for therapeutic intervention in breast cancer.