Transcription factor RUNX2 up-regulates chemokine receptor CXCR4 to promote invasive and metastatic potentials of human gastric cancer

Exploring the Interplay of RUNX2 and CXCR4 in Melanoma Progression

Overexpression of the Runt-related transcription factor 2 (RUNX2) has been reported in several cancer types, and the C-X-C motif chemokine receptor 4 (CXCR4) has an important role in tumour progression. However, the interplay between CXCR4 and RUNX2 in melanoma cells remains poorly understood. In the present study, we used melanoma cells and a RUNX2 knockout (RUNX2-KO) in vitro model to assess the influence of RUNX2 on CXCR4 protein levels along with its effects on markers associated with cell invasion and autophagy. Osteotropism was assessed using a 3D microfluidic model. Moreover, we assessed the impact of CXCR4 on the cellular levels of key cellular signalling proteins involved in autophagy. We observed that melanoma cells express both RUNX2 and CXCR4. Restored RUNX2 expression in RUNX2 KO cells increased the expression levels of CXCR4 and proteins associated with the metastatic process. The protein markers of autophagy LC3 and beclin were upregulated in response to increased CXCR4 levels. The CXCR4 inhibitor WZ811 reduced osteotropism and activated the mTOR and p70-S6 cell signalling proteins. Our data indicate that the RUNX2 transcription factor promotes the expression of the CXCR4 chemokine receptor on melanoma cells, which in turn promotes autophagy, cell invasiveness, and osteotropism, through the inhibition of the mTOR signalling pathway. Our data suggest that RUNX2 promotes melanoma progression by upregulating CXCR4, and we identify the latter as a key player in melanoma-related osteotropism.

RUNX2 as a Prognostic Factor in Human Cancers

The RUNX2 transcription factor was discovered as an essential transcriptional regulator for commitment to osteoblast lineage cells and bone formation. Expression of RUNX2 in other tissues, such as breast, prostate, and lung, has been linked to oncogenesis, cancer progression, and metastasis. In this study, we sought to determine the extent of RUNX2 involvement in other tumors using a pan-cancer analysis strategy. We correlated RUNX2 expression and clinical-pathological parameters in human cancers by interrogating publicly available multiparameter clinical data. Our analysis demonstrated that altered RUNX2 expression or function is associated with several cancer types from different tissues. We identified three tumor types associated with increased RUNX2 expression and four other tumor types associated with decreased RUNX2 expression. Our pan-cancer analysis for RUNX2 revealed numerous other discoveries for RUNX2 regulation of different cancers identified in each of the pan-cancer databases. Both up and down regulation of RUNX2 was observed during progression of specific types of cancers in promoting the distinct types of cancers.

Long non-coding RNAs as the critical regulators of PI3K/AKT, TGF-β, and MAPK signaling pathways during breast tumor progression

Breast cancer (BC) as one of the most common causes of human deaths among women, is always considered one of the global health challenges. Despite various advances in diagnostic and therapeutic methods, a significant percentage of BC patients have a poor prognosis due to the lack of therapeutic response. Therefore, investigating the molecular mechanisms involved in BC progression can improve the therapeutic and diagnostic strategies in these patients. Cytokine and growth factor-dependent signaling pathways play a key role during BC progression. In addition to cytokines and growth factors, long non-coding RNAs (lncRNAs) have also important roles in regulation of such signaling pathways. Therefore, in the present review we discussed the role of lncRNAs in regulation of PI3K/AKT, MAPK, and TGF-β signaling pathways in breast tumor cells. It has been shown that lncRNAs mainly have an oncogenic role through the promotion of these signaling pathways in BC. This review can be an effective step in introducing the lncRNAs inhibition as a probable therapeutic strategy to reduce tumor growth by suppression of PI3K/AKT, MAPK, and TGF-β signaling pathways in BC patients. In addition, considering the oncogenic role and increased levels of lncRNAs expressions in majority of the breast tumors, lncRNAs can be also considered as the reliable diagnostic markers in BC patients.

RUNX2 promotes gastric cancer progression through the transcriptional activation of MGAT5 and MMP13

Introduction

RUNX2 is overexpressed in gastric cancer but the mechanism(s) through which it promotes tumor progression remain undefined. Here, we investigated the role of RUNX2 on gastric cancer pathogenesis at the molecular level.

Methods

The qRT-PCR and western bolt were utilized to examine the mRNA and protein levels. CCK-8, Transwell and wound healing assays were used to measure cell proliferation, invasion and migration. CHIP-PCR gel electrophoresis was used to verify RUNX2 as a transcription factor for MMP13 and MGAT5. The in vivo assay was utilized to assess tumor growth. In vivo assay was used to evaluate tumor growth, aberrant expression of RUNX2 and lung metastasis of gastric cancer.

Results

RUNX2 is overexpressed in MKN-45 and AGS cells. Genetic RUNX2 silencing reduced the proliferation, invasion and migration of MKN-45 and AGS cells. Analysis of the gastric cancer samples from the database revealed a significant positive correlation between MGAT5, MMP13, and RUNX2 expression. JASPAR analysis revealed that there was a potential binding site of RUNX2 in the promoter regions of MGAT5 and MMP13, and the experimental results confirmed that RUNX2 could regulate the expression of MGAT5 and MMP13 respectively. In vivo assays confirmed the aberrant expression of RUNX2 in mouse models of gastric cancer and reduced growth and lung metastasis in RUNX2 silenced xenograft tumors assessed.

Conclusion

Collectively, these data reveal that RUNX2 enhances MGAT5 and MMP13 expression in gastric cancer cells and represents a biomarker and potential therapeutic target for gastric cancer therapy.

METTL14 promotes migration and invasion of choroidal melanoma by targeting RUNX2 mRNA via m6A modification

The modification of N6-methyladenosine is involved in the progression of various cancers. This study aimed to clarify its regulatory mechanism in the pathogenesis of choroidal melanoma. Expression of methyltransferase-like 14 in choroidal melanoma or normal choroidal tissues was determined by Western blot and immunohistochemistry. The impacts of methyltransferase-like 14 on invasion and migration of choroidal melanoma cells were determined using functional and animal experiments. The interaction between methyltransferase-like 14 and its downstream target was identified by methylated RNA immunoprecipitation and a dual-luciferase reporter assay. Additionally, Wnt/β-catenin signalling pathway was evaluated by Western blot. Methyltransferase-like 14 was upregulated in choroidal melanoma compared to the normal choroidal tissues. Overexpression or knockdown of methyltransferase-like 14 enhanced or inhibited the invasion and migration of choroidal melanoma cells, respectively, both in vivo and in vitro. Methyltransferase-like 14 directly targeted downstream runt-related transcription factor 2 mRNA, depending on N6-methyladenosine. Additionally, the Wnt/β-catenin signalling pathway was activated by methyltransferase-like 14 in choroidal melanoma cells. Our study identified a novel RNA regulatory mechanism in which runt-related transcription factor 2 was upregulated by enhanced expression of methyltransferase-like 14 via N6-methyladenosine modification, thus facilitating migration and invasion of choroidal melanoma cells.

MicroRNAs and osteosarcoma: Potential targets for inhibiting metastasis and increasing chemosensitivity

Osteosarcoma (OS) is the third most common cancer in young adults after lymphoma and brain cancer. Metastasis, like other cellular events, is dependent on signaling pathways; a series of changes in some proteins and signaling pathways pave the way for OS cells to invade and migrate. Ezrin, TGF-β, Notch, RUNX2, matrix metalloproteinases (MMPs), Wnt/β-catenin, and phosphoinositide 3-kinase (PI3K)/AKT are among the most important of these proteins and signaling pathways. Despite the improvements in treating OS, the overall survival of patients suffering from the metastatic disease has not experienced any significant change after surgical treatments and chemotherapy and 5-years overall survival in patients with metastatic OS is about 20%. Studies have shown that overexpression or inhibition of some microRNAs (miRNAs) has significant effects in limiting the invasion and migration of OS cells. The results of these studies highlight the potential of the clinical application of some miRNA mimics and miRNA inhibitors (antagomiRs) to inhibit OS metastasis in the future. In addition, some studies have shown that miRNAs are associated with the most important drug resistance mechanisms in OS, and some miRNAs are highly effective targets to increase chemosensitivity. The results of these studies suggest that miRNA mimics and antagomiRs may be helpful to increase the efficacy of conventional chemotherapy drugs in the treatment of metastatic OS. In this article, we discussed the role of various signaling pathways and the involved miRNAs in the metastasis of OS, attempting to provide a comprehensive review of the literature on OS metastasis and chemosensitivity.

Hippo in Gastric Cancer: From Signalling to Therapy

The Hippo pathway is one of the most important ones in mammals. Its key functions in cell proliferation, tissue growth, repair, and homeostasis make it the most crucial one to be controlled. Many means have been deployed for its regulation, since this pathway is not only composed of core regulatory components, but it also communicates with and regulates various other pathways, making this signalisation even more complex. Its role in cancer has been studied more and more over the past few years, and it presents YAP/TAZ as the major oncogenic actors. In this review, we relate how vital this pathway is for different organs, and how regulatory mechanisms have been bypassed to lead to cancerous states. Most studies present an upregulation status of YAP/TAZ, and urge the need to target them. A focus is made here on gastric carcinogenesis, its main dysregulations, and the major strategies adopted and tested to counteract Hippo pathway disbalance in this disease. Hippo pathway targeting can be achieved by various means, which are described in this review. Many studies have tested different potential molecules, which are detailed hereby. Though not all tested in gastric cancer, they could represent a real interest.

The transcription factor RUNX2 fuels YAP1 signaling and gastric cancer tumorigenesis

Despite considerable efforts in the detection and treatment of gastric cancer (GC), the underlying mechanism of the progression of GC remains unknown. Our previous work has demonstrated the remarkable role of Runt‐related transcription factor 2 (RUNX2), in fueling the invasion and metastasis of GC. The present study aimed to elucidate the role of RUNX2 in tumorigenesis of GC. We assessed Runx2 expression and its clinical significance via bioinformatic analysis of the Cancer Genome Atlas and Gene Expression Omnibus databases. Roles for Runx2 in self‐renewal and tumorigenesis were examined in vitro and in vivo. Further bioinformatic analysis was applied to study the mechanism of GC progression. We found that Runx2 was highly expressed in the early stage of GC and positively correlated with a poor clinical outcome of patients. Runx2 was also significantly correlated with clinicopathological features, such as Hp infection, new neoplastic events, primary therapeutic outcome, ethnicity, race, and tumor stage. Multivariate analysis revealed that together with Runx2, age, cancer status, M stage, and T stage were independent prognostic factors for the outcome of GC patients. RUNX2 overexpression induced increased anchorage‐independent colony formation, sphere formation, and tumorigenesis in GC cells in vitro and in vivo. Mechanistically, bioinformatic analysis indicated that yes1 associated transcriptional regulator (YAP1) might be a downstream target of RUNX2. Specific knockdown of YAP1 reduced the tumor‐initiating ability of GC cells induced by ectopic Runx2 expression. Our findings support the hypothesis that RUNX2 exerts oncogenic properties via YAP1 regulation, highlighting essential roles for RUNX2 and YAP1 in gastric carcinogenesis and suggesting potential therapeutic targets.

MRE11 promotes oral cancer progression through RUNX2/CXCR4/AKT/FOXA2 signaling in a nuclease-independent manner

MRE11, the nuclease component of RAD50/MRE11/NBS1 DNA repair complex which is essential for repair of DNA double-strand-breaks in normal cells, has recently garnered attention as a critical factor in solid tumor development. Herein we report the crucial role of MRE11 in oral cancer progression in a nuclease-independent manner and delineate its key downstream effectors including CXCR4. MRE11 expression in oral cancer samples was positively associated with tumor size, cancer stage and lymph node metastasis, and was predictive of poorer patient survival and radiotherapy resistance. MRE11 promoted cell proliferation/migration/invasion in a nuclease-independent manner but enhanced radioresistance via a nuclease-dependent pathway. The nuclease independent promotion of EMT and metastasis was mediated by RUNX2, CXCR4, AKT, and FOXA2, while CXCR4 neutralizing antibody mitigated these effects in vitro and in vivo. Collectively, MRE11 may serve as a crucial prognostic factor and therapeutic target in oral cancer, displaying dual nuclease dependent and independent roles that permit separate targeting of tumor vulnerabilities in oral cancer treatment.

RUNX2 promotes malignant progression in gastric cancer by regulating COL1A1

BACKGROUND

Runt-related transcription factor 2 (RUNX2) is an important gene that has been implicated in the progression of human cancer. Aberrant expression of RUNX2 predicts gastric cancer (GC) metastasis. However, the molecular mechanism of RUNX2 remains unknown.

OBJECTIVE

We hypothesize that RUNX2 promotes GC metastasis by regulating the extracellular matrix component collagen type I alpha 1 (COL1A1).

METHODS

The GEPIA database and immunohistochemical staining of 60 GC tissues were used to analyse the correlations between RUNX2 or COL1A1 expression and clinicopathological features, and the Kaplan-Meier method was used to evaluate survival. RT-PCR, western blotting and immunofluorescence were used to detect RUNX2 and COL1A1 expression in GC cells. Migration and invasion assays were performed to assess the influence of RUNX2 and COL1A1 on metastasis.

RESULTS

RUNX2 and COL1A1 were highly expressed at both the gene and protein levels in GC, and patients who were positive for RUNX2 and COL1A1 had shorter survival. RUNX2 and COL1A1 expression linearly correlated with each other (r= 0.15, p< 0.01) and with clinical stage and lymph node metastasis (p< 0.05). Overexpressing RUNX2in vitro enhanced COL1A1 expression and promoted GC cell invasion and migration, whereas COL1A1 knockdown inhibited the increase in cell metastatic capacity promoted by RUNX2. In vivo, GC cells overexpressing RUNX2 promoted lung metastasis, and the downregulation of COL1A1 reduced the metastasis promoted by RUNX2.

CONCLUSIONS

RUNX2 may promote GC metastasis by regulating COL1A1. RUNX2/COL1A1 can be employed as a novel target for therapy in GC.

RUNX2 as a promising therapeutic target for malignant tumors

The transcription factor runt-related protein 2 (RUNX2) has an important impact on the transformation of bone marrow mesenchymal stem cells to osteoblasts. Further studies have shown that RUNX2 plays a key role in the invasion and metastasis of cancers. RUNX2 is a "key" molecule in the regulatory network comprised of multiple signaling pathways upstream and its target downstream molecules. Due to the complex regulatory mechanisms of RUNX2, the specific mechanism underlying the occurrence, development and prognosis of malignant tumors has not been fully understood. Currently, RUNX2 as a promising therapeutic target for cancers has become a research hotspot. Herein, we reviewed the current literature on the modulatory functions and mechanisms of RUNX2 in the development of malignant tumors, aiming to explore its potential clinical application in the diagnosis, prognosis and treatment of tumors.

RUNX2 regulates leukemic cell metabolism and chemotaxis in high-risk T cell acute lymphoblastic leukemia

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy with inferior outcome compared with that of B cell ALL. Here, we show that Runt-related transcription factor 2 (RUNX2) was upregulated in high-risk T-ALL with KMT2A rearrangements (KMT2A-R) or an immature immunophenotype. In KMT2A-R cells, we identified RUNX2 as a direct target of the KMT2A chimeras, where it reciprocally bound the KMT2A promoter, establishing a regulatory feed-forward mechanism. Notably, RUNX2 was required for survival of immature and KMT2A-R T-ALL cells in vitro and in vivo. We report direct transcriptional regulation of CXCR4 signaling by RUNX2, thereby promoting chemotaxis, adhesion, and homing to medullary and extramedullary sites. RUNX2 enabled these energy-demanding processes by increasing metabolic activity in T-ALL cells through positive regulation of both glycolysis and oxidative phosphorylation. Concurrently, RUNX2 upregulation increased mitochondrial dynamics and biogenesis in T-ALL cells. Finally, as a proof of concept, we demonstrate that immature and KMT2A-R T-ALL cells were vulnerable to pharmacological targeting of the interaction between RUNX2 and its cofactor CBFβ. In conclusion, we show that RUNX2 acts as a dependency factor in high-risk subtypes of human T-ALL through concomitant regulation of tumor metabolism and leukemic cell migration.

Long non-coding RNA DUXAP8 promotes the cell proliferation, migration, and invasion of papillary thyroid carcinoma via miR-223-3p mediated regulation of CXCR4

Papillary thyroid carcinoma (PTC) is a differentiated type of thyroid malignancy with a high incidence. Long non-coding RNA (lncRNA) DUXAP8 has been reported to participate in the proliferation, migration, and invasion of several cancer types. However, its association with PTC has not yet been reported. The current study aimed to investigate the role of DUXAP8 in PTC and revealed the underlying mechanisms. The expression of DUXAP8 was knocked down in two PTC cell lines and the effects of DUXAP8 on the PTC biological behavior were examined by cell counting kit-8 (CCK-8), wound healing, and transwell invasion assays. Luciferase reporter assay was used to detect the binding activity between miR-223-3p and DUXAP8. We found that knockdown of DUXAP8 inhibited the proliferation, migration, and invasion of PTC cells. DUXAP8 could sponge miR-223-3p through the specific binding site. CXCR4 was a target of miR-223-3p. The malignant phenotypes of the PTC cells were suppressed by the over-expression of miR-223-3p. Moreover, miR-223-3p inhibition or CXCR4 over-expression partly restored the proliferation, migration, and invasion activities of DUXAP8-downregulated PTC cells. The results evidenced that DUXAP8 acted as an oncogene in PTC, these effects seemed to partly dependent on the miR-223-3p/CXCR4 axis.

LncRNA NORAD promotes bone marrow stem cell differentiation and proliferation by targeting miR-26a-5p in steroid-induced osteonecrosis of the femoral head

BACKGROUND

Steroid-induced osteonecrosis of the femoral head (SONFH) is a devastating orthopedic disease, which seriously affects the quality of life of patients. The study aims to investigate the effects of LncRNA NORAD on SONFH.

METHODS

Human bone marrow-derived mesenchymal stem cells (hBMSCs) were isolated from the proximal femur of patients during routine orthopedic surgery and then cultured with dexamethasone (Dex) and transfected with NORAD overexpression vector, siRNA-NORAD and miR-26a-5p mimics. The mRNA expression of NORAD, miR-26a-5p, OPG, RANK, and RANKL was detected by RT-qPCR. Cell proliferation and apoptosis was measured by CCK-8 assay and flow cytometry, respectively. The protein expression of RUNX2, OPG, RANK, and RANKL was detected by western blot. The dual-luciferase reporter gene assay was performed to confirm the binding between NORAD and miR-26a-5p.

RESULTS

NORAD expression was downregulated in SONFH tissues, while miR-26a-5p expression was upregulated. Overexpression of NORAD improved DEX-induced inhibition of proliferation and differentiation, and promotion of apoptosis in hBMSCs, while knockdown of NORAD led to the opposite results. Moreover, NORAD improved DEX-induced inhibition of proliferation and differentiation, and promotion of apoptosis by regulation of miR-26a-5p in hBMSCs.

CONCLUSIONS

NORAD expression was downregulated in SONFH tissues, while miR-26a-5p expression was upregulated. NORAD improved DEX-induced inhibition of proliferation and differentiation, and promotion of apoptosis by regulation of miR-26a-5p in hBMSCs.

The Role of the CXCL12/CXCR4/CXCR7 Chemokine Axis in Cancer

Chemokines are a family of small, secreted cytokines which regulate a variety of cell functions. The C-X-C motif chemokine ligand 12 (CXCL12) binds to C-X-C chemokine receptor type 4 (CXCR4) and C-X-C chemokine receptor type 7 (CXCR7). The interaction of CXCL12 and its receptors subsequently induces downstream signaling pathways with broad effects on chemotaxis, cell proliferation, migration, and gene expression. Accumulating evidence suggests that the CXCL12/CXCR4/CXCR7 axis plays a pivotal role in tumor development, survival, angiogenesis, metastasis, and tumor microenvironment. In addition, this chemokine axis promotes chemoresistance in cancer therapy via complex crosstalk with other pathways. Multiple small molecules targeting CXCR4/CXCR7 have been developed and used for preclinical and clinical cancer treatment. In this review, we describe the roles of the CXCL12/CXCR4/CXCR7 axis in cancer progression and summarize strategies to develop novel targeted cancer therapies.

TCR Redirected T Cells for Cancer Treatment: Achievements, Hurdles, and Goals

Adoptive T cell therapy (ACT) is a rapidly evolving therapeutic approach designed to harness T cell specificity and function to fight diseases. Based on the evidence that T lymphocytes can mediate a potent anti-tumor response, initially ACT solely relied on the isolation, in vitro expansion, and infusion of tumor-infiltrating or circulating tumor-specific T cells. Although effective in a subset of cases, in the first ACT clinical trials several patients experienced disease progression, in some cases after temporary disease control. This evidence prompted researchers to improve ACT products by taking advantage of the continuously evolving gene engineering field and by improving manufacturing protocols, to enable the generation of effective and long-term persisting tumor-specific T cell products. Despite recent advances, several challenges, including prioritization of antigen targets, identification, and optimization of tumor-specific T cell receptors, in the development of tools enabling T cells to counteract the immunosuppressive tumor microenvironment, still need to be faced. This review aims at summarizing the major achievements, hurdles and possible solutions designed to improve the ACT efficacy and safety profile in the context of liquid and solid tumors.

Identification of the hub genes RUNX2 and FN1 in gastric cancer

Background

This study identified key genes in gastric cancer (GC) based on the mRNA microarray GSE19826 from the Gene Expression Omnibus (GEO) database and preliminarily explored the relationships among the key genes.

Methods

Differentially expressed genes (DEGs) were obtained using the GEO2R tool. The functions and pathway enrichment of the DEGs were analyzed using the Enrichr database. Protein–protein interactions (PPIs) were established by STRING. A lentiviral vector was constructed to silence RUNX2 expression in MGC-803 cells. The expression levels of RUNX2 and FN1 were measured. The influences of RUNX2 and FN1 on overall survival (OS) were determined using the Kaplan–Meier plotter online tool.

Results

In total, 69 upregulated and 65 downregulated genes were identified. Based on the PPI network of the DEGs, 20 genes were considered hub genes. RUNX2 silencing significantly downregulated the FN1 expression in MGC-803 cells. High expression of RUNX2 and low expression of FN1 were associated with long survival time in diffuse, poorly differentiated, and lymph node-positive GC.

Conclusion

High RUNX2 and FN1 expression were associated with poor OS in patients with GC. RUNX2 can negatively regulate the secretion of FN1, and both genes may serve as promising targets for GC treatment.

Runx2 is required for activity of CD44+/CD24-/low breast cancer stem cell in breast cancer development

Runx2, a master regulator of osteogenesis, is abnormally expressed in advanced breast cancer. Here we addressed Runx2 contribution to breast cancer cell growth and metastasis. We found that CD44 and Runx2 were both elevated in breast cancer tissues compared with the adjacent normal tissues in breast cancer patients. Runx2 expression was significantly correlated with tumor TNM stage, metastasis and poor prognosis. We then screened several breast cancer cell lines and found that Runx2 expression level was positively related to the malignant level of the cells screened. Knockdown of Runx2 in high metastatic cell line MDA-MB-231 could inhibit breast cancer cell vitality, invasion and clone formation capacity, while overexpression of Runx2 in low metastatic cell line MCF-7 could increase those malignant behaviors. The mechanism might be due to Runx2 positively regulating cancer stem cell properties, as CD44 expression level and CD44⁺/CD24^-/low breast cancer stem cell population were both significantly decreased in Runx2 knockdown cells. Cancer stem cell renewal ability such as soft agar clone formation, mammospheres formation and tumor formation ability in null mice were all decreased after knockdown of Runx2. On the contrary, overexpression of Runx2 could enhance all above stem cell renewal ability. Lastly, we explored how Runx2 changes cancer stem cell population. We found it could affect epithelial mesenchymal transition (EMT). Runx2 could regulate mesenchymal marker and epithelial marker expression and affect activation of Wnt/β-catenin signaling pathway. These results together strongly suggest that Runx2 can promote CD44⁺/CD24^-/low breast cancer stem cell properties and breast cancer tumorigenesis through EMT process.

LncRNA E2F-Mediated Cell Proliferation Enhancing lncRNA Regulates Cancer Cell Behaviors and Affects Prognosis of Gastric Cancer

BACKGROUND

A recent study reported a novel long non-coding RNA (lncRNA) E2F-mediated cell proliferation enhancing lncRNA (EPEL, human chromosome 4, intergenic region) plays an oncogenic role in lung cancer.

AIMS

We aimed to investigate the role of lncRNA EPEL in gastric cancer.

METHODS

Gene expression was analyzed by RT-qPCR and western blot. Survival analysis was performed by comparing survival curves. Cell proliferation, migration, and invasion were analyzed by CCK-8 and Transwell assays.

RESULTS

We found that lncRNA EPEL and Runt-related transcription factor 2 (RUNX2) were both upregulated in gastric cancer. EPEL and RUNX2 were positively correlated in tumor. Patients with high expression level of lncRNA EPEL showed poor survival. LncRNA EPEL and RUNX2 overexpression promoted, while lncRNA EPEL siRNA silencing inhibited the migration, proliferation, and invasion of gastric cancers. In addition, RUNX2 overexpression completely rescued the inhibited cancer cell migration, proliferation, and invasion caused by lncRNA EPEL siRNA silencing. Consistently, EPEL overexpression resulted in upregulated RUNX2 expression, while RUNX2 overexpression did not affect lncRNA EPEL expression.

CONCLUSIONS

Therefore, lncRNA EPEL may regulate cancer cell behaviors and affect prognosis of gastric cancer by interacting with RUNX2.

Loss of the nuclear Wnt pathway effector TCF7L2 promotes migration and invasion of human colorectal cancer cells

The transcription factor TCF7L2 is indispensable for intestinal tissue homeostasis where it transmits mitogenic Wnt/β-Catenin signals in stem and progenitor cells, from which intestinal tumors arise. Yet, TCF7L2 belongs to the most frequently mutated genes in colorectal cancer (CRC), and tumor-suppressive functions of TCF7L2 were proposed. This apparent paradox warrants to clarify the role of TCF7L2 in colorectal carcinogenesis. Here, we investigated TCF7L2 dependence/independence of CRC cells and the cellular and molecular consequences of TCF7L2 loss-of-function. By genome editing we achieved complete TCF7L2 inactivation in several CRC cell lines without loss of viability, showing that CRC cells have widely lost the strict requirement for TCF7L2. TCF7L2 deficiency impaired G1/S progression, reminiscent of the physiological role of TCF7L2. In addition, TCF7L2-negative cells exhibited morphological changes, enhanced migration, invasion, and collagen adhesion, albeit the severity of the phenotypic alterations manifested in a cell-line-specific fashion. To provide a molecular framework for the observed cellular changes, we performed global transcriptome profiling and identified gene-regulatory networks in which TCF7L2 positively regulates the proto-oncogene MYC, while repressing the cell cycle inhibitors CDKN2C/CDKN2D. Consistent with its function in curbing cell motility and invasion, TCF7L2 directly suppresses the pro-metastatic transcription factor RUNX2 and impinges on the expression of cell adhesion molecules. Altogether, we conclude that the proliferation-stimulating activity of TCF7L2 persists in CRC cells. In addition, TCF7L2 acts as invasion suppressor. Despite its negative impact on cell cycle progression, TCF7L2 loss-of-function may thereby increase malignancy, which could explain why TCF7L2 is mutated in a sizeable fraction of colorectal tumors.

BET protein inhibitor JQ1 downregulates chromatin accessibility and suppresses metastasis of gastric cancer via inactivating RUNX2/NID1 signaling

Chromatin accessibility is critical for tumor development, whose mechanisms remain unclear. As a crucial regulator for chromatin remodeling, BRD4 promotes tumor progression by regulating multiple genes. As a small-molecule inhibitor of BRD4, JQ1 has potent chemotherapeutic activity against various human cancers. However, whether JQ1 has potential anti-tumor effects and how JQ1 regulates global transcription in gastric cancer (GC) remain largely unknown. In this research, we found BRD4 was highly expressed in GC tissues and was significantly associated with poor prognosis. JQ1 inhibited the proliferation and induced apoptosis of GC cells in vitro. Besides, JQ1 suppressed the migration and invasion of cancer cells by inducing MET. Notably, an assay for transposase-accessible chromatin using sequencing (ATAC-seq) data showed that JQ1 obviously downregulated the chromatin accessibility of GC cells and differentially accessible regions were highly enriched for RUNX2-binding motifs. Combinational analysis of ATAC-seq and RNA-seq data discovered NID1 as the downstream target of JQ1 and JQ1 reduced NID1 expression in GC cells. Chromatin immunoprecipitation, luciferase reporter gene assay, and rescue experiments all confirmed that RUNX2/NID1 axis was responsible for JQ1-inhibiting metastasis of GC cells. What’s more, high expression of NID1 in GC tissues also predicted poor survival outcome of cancer patients and NID1 knockdown prohibited migration and invasion of cancer cells via partially inducing MET. Finally, in vivo models showed that JQ1 prevented GC growth and suppressed cancer metastasis. In conclusion, JQ1 inhibits the malignant progression of GC by downregulating chromatin accessibility and inactivating RUNX2/NID1 signaling. In addition, NID1 is also a novel therapeutic target for progressive GC patients.

LncRNA COL1A1-014 is involved in the progression of gastric cancer via regulating CXCL12-CXCR4 axis

BACKGROUND

The aberrant expression of long noncoding RNAs (lncRNAs) is found in various types of cancers and also showed its association with the occurrence and development of gastric cancer (GC). We found lncRNA COL1A1-014 was frequently upregulated in GC.

METHODS

This study investigated COL1A1-014 for its biological function at both cellular and animal levels, using MTT, flow cytometry, colony formation and transwell assays. The expression levels of COL1A1-014 and other genes were detected by RT-PCR and western blot. Luciferase reporter assay was used to detect the potential binding of miR-1273h-5p to COL1A1-014 and CXCL12.

RESULTS

We found that COL1A1-014 was frequently upregulated in GC tissues as well as cells. COL1A1-014 increased cell proliferation, colony forming efficiency, migration ability, invasion ability, and weight and volume of grafted tumors, while reduced cell apoptosis. Overexpression of COL1A1-014 increased the mRNA expression of chemokine (CXCmotif) ligand (CXCL12) and high levels of CXCL12 and CXCR4 proteins in GC cells. The levels of miR-1273h-5p showed an inverse correlation with COL1A1-014 and CXCL12 in GC cells transfected with miR-1273h-5p. The mRNAs of wild-type COL1A1-014 and CXCL12 showed reduction in HEK293 cells transfected with miR-1273h-5p. This suggested that COL1A1-014 functions as an efficient miR-1273h-5p sponge and as a competing endogenous RNA (ceRNA) to regulate CXCL12. The proliferative activity of COL1A1-014 on GC cells was blocked by CXCL12-CXCR4 axis inhibitor AMD-3100.

CONCLUSIONS

These findings demonstrated that COL1A1-014 play an important regulatory role in GC development by functioning as a ceRNA in regulating the CXCL12/CXCR4 axis via sponging miR-1273h-5p.

Downregulation of MANCR inhibits cancer cell proliferation in mantle cell lymphoma possibly by interacting with RUNX2

The mitotically associated lncRNA (MANCR) participates in breast cancer cell proliferation, while its involvement in other cancers is still unknown. In this study, we therefore studied the role of MANCR in mantle cell lymphoma (MCL). We found that serum MANCR and Runt-related transcription factor 2 (RUNX2) were upregulated in MCL patients when compared with those in healthy controls. A positive correlation between serum MANCR and RUNX2 was found in MCL patients but not in controls. Upregulation of serum MANCR distinguished MCL patients from controls. MANCR overexpression promoted RUNX2 expression in MCL cells, while RUNX2 overexpression failed to significantly change the expression levels of MANCR. MANCR overexpression promoted the proliferation of MCL cells, while MANCR silencing inhibited the proliferation of MCL cells. In addition, RUNX2 overexpression attenuated the inhibitory effects of MANCR silencing on cell proliferation. However, MANCR overexpression and silencing had no significant effects on cell migration and invasion. Further bioinformatics analysis showed that MANCR may sponge miR-218 to upregulate RUNX2. Therefore, we conclude that downregulation of MANCR may inhibit cancer cell proliferation in MCL possibly by interacting with RUNX2.

Inhibition of human cervical cancer cell invasion by IL-37 involving runt related transcription factor 2 suppression

Background

IL-37 is a newly anti-inflammatory cytokine whose function is largely unknown in cancer. Our preliminary experiment found IL-37 could inhibit the invasion of human cervical cancer (CC) cells and influence the expression of RUNX family whose function was also unclear in CC. The present study aims to further investigate the effects of IL-37 on cell invasion and runt related transcription factor 2 (RUNX2) expression in CC cell lines.

Methods

Firstly, plasmid overexpressing IL-37 or RUNX2 was transfected into Siha and C33A cells by Hilymax. Then, the effects of IL-37 on the mRNA expression of RUNX1, RUNX2 and RUNX3 gene were detected by quantitative real-time polymerase chain reaction. Protein expression was measured by Western blot and the grayscale scanning analysis. Finally, the effects of IL-37 or RUNX2 on cell invasion were tested by transwell assay.

Results

IL-37 inhibited the mRNA expression of RUNX1 and RUNX2, and increased that of RUNX3 in CC cells. Among the three RUNX genes, RUNX2 showed the most significant change in mRNA expression (decreased by78.5% in Siha cells and by 61.5% in C33A cells) and thus was chosen for the following study. Overexpressed IL-37 inhibited cell invasion by 36.23% in Siha cells (P<0.05) and 26.21% in C33A cells (P<0.01). Overexpression of RUNX2 promoted cell invasion. Up-regulation of IL-37 suppressed markedly the mRNA and protein expression of RUNX2. Furthermore, overexpressed RUNX2 partially restored the inhibited cell invasion by IL-37 to 86.62% in Siha cells (P<0.01) and 87.08% in C33A cells (P<0.01).

Conclusions

IL-37 can significantly inhibit the cell invasion of Siha and C33A cells, which involves the suppression of RUNX2.

RUNX2 overexpression and PTEN haploinsufficiency cooperate to promote CXCR7 expression and cellular trafficking, AKT hyperactivation and prostate tumorigenesis

Rationale: The overall success rate of prostate cancer (PCa) diagnosis and therapy has been improved over the years. However, genomic and phenotypic heterogeneity remains a major challenge for effective detection and treatment of PCa. Efforts to better classify PCa into functional subtypes and elucidate the molecular mechanisms underlying prostate tumorigenesis and therapy resistance are warranted for further improvement of PCa outcomes. Methods: We generated Cre+;Runx2-cTg;Ptenp/+ (Runx2-Pten double mutant) mice by crossbreeding Cre+;Runx2-cTg males with Pten conditional (Ptenp/p) females. By using Hematoxylin and Eosin (H&E) staining, SMA and Masson's Trichrome staining, we investigated the effect of PTEN haploinsufficiency in combination with Runx2 overexpression on prostate tumorigenesis. Moreover, we employed immunohistochemistry (IHC) to stain Ki67 for cell proliferation, cleaved caspase 3 for apoptosis and AKT phosphorylation for signaling pathway in prostate tissues. Chromatin immunoprecipitation coupled quantitative PCR (ChIP-qPCR), reverse transcription coupled quantitative PCR (RT-qPCR), western blot (WB) analyses and immunofluorescence (IF) were conducted to determine the underlying mechanism by which RUNX2 regulates CXCR7 and AKT phosphorylation in PCa cells. Results: We demonstrated that mice with prostate-specific Pten heterozygous deletion and Runx2 overexpression developed high-grade prostatic intraepithelial neoplasia (HGPIN) and cancerous lesions at age younger than one year, with concomitant high level expression of Akt phosphorylation and the chemokine receptor Cxcr7 in malignant glands. RUNX2 overexpression induced CXCR7 transcription and membrane location and AKT phosphorylation in PTEN-deficient human PCa cell lines. Increased expression of RUNX2 also promoted growth of PCa cells and this effect was largely mediated by CXCR7. CXCR7 expression also positively correlated with AKT phosphorylation in PCa patient specimens. Conclusions: Our results reveal a previously unidentified cooperative role of RUNX2 overexpression and PTEN haploinsufficiency in prostate tumorigenesis, suggesting that the defined RUNX2-CXCR7-AKT axis can be a viable target for effective treatment of PCa.

MALAT1 regulates the transcriptional and translational levels of proto-oncogene RUNX2 in colorectal cancer metastasis

Ectopic expression of lncRNA-MALAT1 has been discovered in recurrent colorectal cancer (CRC) and metastatic sites in postsurgical patients, however, its biological mechanism remained unelucidated. Our study first revealed the novel roles of MALAT1 in promoting CRC metastasis through two mechanisms: first, MALAT1 binds miR-15 family members, to “de-inhibit” their effect on LRP6 expression, enhances β-catenin signaling, leading to elevated transcriptional levels of downstream target genes RUNX2. Second, MALAT1 binds SFPQ, and dissociates SFPQ/PTBP2 dimer to release free PTBP2, which elevates translational levels of RUNX2, through interacting with IRES domain in the 5′UTR of the corresponding RUNX2 mRNAs. Moreover, increased RUNX2 expression levels were detected in recurrent CRC tumors, which were closely associated with TMN stages, metastasis, as well as CRC patients’ survival. Our study demonstrated that MALAT1 and RUNX2 may serve as two biomarkers for predicting the recurrence and metastasis of CRC patients.

High long non-coding RNA NORAD expression predicts poor prognosis and promotes breast cancer progression by regulating TGF-β pathway

Background

To investigate the expression and significance of long noncoding RNA NORAD (lncRNA-NORAD) in breast cancer.

Methods

Q-PCR was adopted to detect the mRNA expression of lncRNA-NORAD in breast cancer and adjacent tissues, survival analysis to compare the low-expression groups with the Kaplan-Meier method. Knockout of lncRNA-NORAD was adopted to observe the effects on the cell proliferation, migration and invasion of breast cancer in vitro and in vivo. The TGF-β/RUNX2 signaling pathway was observed by Western blot after the knockout of lncRNA-NORAD.

Results

Increased expression of lncRNA-NORAD in breast cancer tissues promotes proliferation, invasion and migration of breast cancer cells and correlated with worse prognosis. LncRNA-NORAD activated TGF-β/RUNX2 signaling pathway in breast cancer cells.

Conclusions

These results strongly suggested that lncRNA-NORAD might play an important role in breast cancer progression and potentially be a new therapeutic target.

miR-218 overexpression suppresses tumorigenesis of papillary thyroid cancer via inactivation of PTEN/PI3K/AKT pathway by targeting Runx2

Background

It was previously reported that downregulation of miR-218 promoted thyroid cancer cell invasion, migration, and proliferation. However, the biological functions of miR-218 and its possible regulatory mechanisms in papillary thyroid cancer (PTC) cells are still elusive.

Materials and methods

The expression levels of miR-218 and Runx2 in PTC tissues and cells were determined by quantitative real-time PCR (qRT-PCR) and Western blot. The effects of miR-218 overexpression on cell viability, invasion, apoptosis, and PTEN/PI3K/AKT pathway in PTC cells were evaluated by cell counting kit-8 assay, Transwell invasion assay, flow cytometry assay, and Western blot, respectively. Luciferase reporter assay and qRT-PCR were performed to identify the target of miR-218. Xenograft tumor experiment was performed to confirm the biological roles of miR-218 and its potential mechanisms in vivo.

Results

miR-218 expression was downregulated and Runx2 expression was upregulated in PTC tissues and cells. Overexpression of miR-218 suppressed viability and invasion, and induced apoptosis of PTC cells in vitro, while Runx2 overexpression greatly abolished these effects. miR-218 overexpression inactivated the PTEN/PI3K/AKT pathway, which was abated by Runx2 upregulation. Additionally, Runx2 was validated to be a direct target of miR-218. Moreover, enforced expression of miR-218 inhibited tumor growth and Runx2 expression, and blocked PTEN/PI3K/AKT pathway in vivo.

Conclusion

miR-218 overexpression suppresses the tumorigenesis of PTC via downregulating PTEN/PI3K/AKT pathway by targeting Runx2, which indicates that miR-218 may be a potential therapeutic target for human PTC.

Ethanol Extract of Lycopus lucidus Turcz. ex Benth Inhibits Metastasis by Downregulation of Runx-2 in Mouse Colon Cancer Cells

Lycopus lucidus Turcz. ex Benth (LT) has been broadly used as a traditional medicinal herb in Asia including Korea, China, and Japan due to its noted ability to promote blood circulation and remove blood stasis. However, its anticancer mechanism is not understood. This study aims to elucidate the effects of ethanol extracts of LT (ELT) relative to the role of Runt-related transcription factor- (Runx-) 2 in the invasive and metastatic potentials of mouse colon cancer to determine the underlying mechanisms involved. ELT was evaluated for the antimetastasis activity using CT-26 colon cancer using wound healing, transwell matrigel, and western blot analysis. We used Runx-2-specific siRNA to further determine the relationship between Runx-2 and matrix metalloprotease- (MMP-) 9 in the migration and invasion of CT-26 cells. Runx-2 was first demonstrated to be a transcription factor that plays a remarkable role in diverse biological processes of chondrocytes and osteoblasts, but recently, Runx-2 has been reported to be associated with the progression of certain human cancers. ELT was not altered in its effects on growth inhibition. However, ELT significantly inhibited wound closure and cell invasion in a dose-dependent manner. ELT decreased the metastasis by regulating the activity of MMP-9 and Runx-2 at the translational levels. Our results demonstrate that ELT decreases metastasis by inhibiting the Runx-2–MMP-9 axis. We suggest that it can be used as a novel agent in therapeutic strategies for combating colon cancer.

Capillary morphogenesis gene 2 maintains gastric cancer stem-like cell phenotype by activating a Wnt/β-catenin pathway

A growing body of evidence shows that the development and progression of gastric cancer (GC) is mainly associated to the presence of gastric cancer stem-like cells (GCSLCs). However, it is unclear how GCSLC population is maintained. This study aimed to explore the role of capillary morphogenesis gene 2 (CMG2) in GCSLC maintenance and the relevance to GC progression. We found that CMG2 was highly expressed in GC tissues and the expression levels were associated with the invasion depth and lymph node metastasis of GC, and inversely correlated with the survival of GC patients. Sorted CMG2^High GC cells preferentially clustered in CD44^High stem-like cell population, which expressed high levels of stemness-related genes with increased capabilities of self-renewal and tumorigenicity. Depletion of CMG2 gene resulted in reduction of GCSLC population with attenuated stemness and decrease of invasive and metastatic capabilities with subdued epithelial–mesenchymal transition phenotype in GC cells. Mechanistically, CMG2 interacted with LRP6 in GCSLCs to activate a Wnt/β-catenin pathway. Thus, our results demonstrate that CMG2 promotes GC progression by maintaining GCSLCs and can serve as a new prognostic indicator and a target for human GC therapy.

Artemin regulates CXCR4 expression to induce migration and invasion in pancreatic cancer cells through activation of NF-κB signaling

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal human malignant tumor because of the early onset of local invasion and distant metastasis. Perineural invasion is a prominent characteristic of pancreatic adenocarcinoma, which is a multifactorial process that involves various signaling molecules from different signaling pathways. The glial cell line-derived neurotrophic factor family of ligands was reported to be involved in perineural invasion in pancreatic cancer. Artemin is one member of the glial cell line-derived neurotrophic factor family of ligands. Although Artemin has previously been demonstrated to promote invasiveness of pancreatic cancer, the mechanisms remain poorly understood. In this study, we performed an analysis to determine the effects of Artemin on modulating tumor cell metastatic potential and invasion activity and explored its mechanisms in pancreatic cancer. We indicated that Artemin and CXCR4 were overexpressed in cancer tissues and widely expressed in pancreatic cancer cell lines. We observed that activation of ERK1/2 and Akt in Artemin-treated cells led to enhanced nuclear accumulation of NF-κB, which then induced CXCR4 expression. Through regulation of the expression of CXCR4, Artemin functionally promoted the migration and invasion in pancreatic cancer cells. The present study indicated that Artemin induced CXCR4 expression by activating Akt and ERK 1/2/NF-κB signaling, thereby modulating tumor cell metastatic potential and invasion activity in pancreatic cancer by regulating SDF-1α/CXCR4 axis. Artemin might be an effective and potent therapeutic target for pancreatic cancer metastasis, especially in perineural invasion.

RET-mediated modulation of tumor microenvironment and immune response in multiple endocrine neoplasia type 2 (MEN2)

Medullary thyroid carcinomas (MTC) arise from thyroid parafollicular, calcitonin-producing C-cells and can occur either as sporadic or as hereditary diseases in the context of familial syndromes, including multiple endocrine neoplasia 2A (MEN2A), multiple endocrine neoplasia 2B (MEN2B) and familial MTC (FMTC). In a large fraction of sporadic cases, and virtually in all inherited cases of MTC, activating point mutations of the RET proto-oncogene are found. RET encodes for a receptor tyrosine kinase protein endowed with transforming potential on thyroid parafollicular cells. As in other cancer types, microenvironmental factors play a critical role in MTC. Tumor-associated extracellular matrix, stromal cells and immune cells interact and influence the behavior of cancer cells both in a tumor-promoting and in a tumor-suppressing manner. Several studies have shown that, besides the neoplastic transformation of thyroid C-cells, a profound modification of tumor microenvironment has been associated to the RET FMTC/MEN2-associated oncoproteins. They influence the surrounding stroma, activating cancer-associated fibroblasts (CAFs), promoting cancer-associated inflammation and suppressing anti-cancer immune response. These mechanisms might be exploited to develop innovative anti-cancer therapies and novel prognostic tools in the context of familial, RET-associated MTC.

PAX3 Promotes Cell Migration and CXCR4 Gene Expression in Neural Crest Cells

Neural crest (NC) cells are a multipotent cell population with powerful migration ability during development. C-X-C chemokine receptor type 4 (CXCR4) is a chemokine receptor implicated to mediate NC migration in various species, whereas the underlying mechanism is not well documented yet. PAX3 is a critical transcription factor for the formation of neural crest and the migration and differentiation of NCs. In this study, we retrieved a potential PAX3 binding element in the promoter of the CXCR4 gene, and we further found that PAX3 could promote the expression of CXCR4 and facilitate the migration of NCs. We finally demonstrated that PAX3 could bind the promoter region of CXCR4 and increase CXCR4 transcription by luciferase assay and electrophoretic mobility shift assay (EMSA). These findings suggested that PAX3 is a pivotal modulator of NC migration via regulating CXCR4 expression.

Runt-related transcription factor 2 (RUNX2) inhibits apoptosis of intestinal epithelial cells in Crohn's disease

Apoptosis in intestinal epithelial cells (IECs) prevents the development of Crohn's disease (CD), a type of inflammatory bowel disease (IBD). Runt-related transcription factor 2 (Runx2) inhibits apoptosis in osteosarcoma-derived U2OS cells via down-regulating the transcriptional activity of p53. However, the expression and function of Runx2 in CD remain unclear. In this study, Runx2 protein levels were decreased in the intestinal epithelial cells (IECs) of CD patients and in a mouse 2, 4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis model; in contrast, the expression levels of p53 and Bax, a p53-target gene, were increased. In a TNF-α-treated HT29 cell colitis model, the down-regulation of Runx2 was accompanied by the up-regulation of apoptotic markers, including cleaved caspase-3 and Bax. Furthermore, Runx2 overexpression effectively decreased TNF-α-induced Bax and cleaved caspase-3 expression levels. In conclusion, our data indicated that Runx2 might protect IECs from apoptosis in CD, thus revealing a novel molecular target for treating CD.

Depletion of runt-related transcription factor 2 (RUNX2) enhances SAHA sensitivity of p53-mutated pancreatic cancer cells through the regulation of mutant p53 and TAp63

Suberoylanilide hydroxamic acid (SAHA) represents one of the new class of anti-cancer drugs. However, multiple lines of clinical evidence indicate that SAHA might be sometimes ineffective on certain solid tumors including pancreatic cancer. In this study, we have found for the first time that RUNX2/mutant p53/TAp63-regulatory axis has a pivotal role in the determination of SAHA sensitivity of p53-mutated pancreatic cancer MiaPaCa-2 cells. According to our present results, MiaPaCa-2 cells responded poorly to SAHA. Forced depletion of mutant p53 stimulated SAHA-mediated cell death of MiaPaCa-2 cells, which was accomapanied by a further accumulation of γH2AX and cleaved PARP. Under these experimental conditions, pro-oncogenic RUNX2 was strongly down-regulated in mutant p53-depleted MiaPaCa-2 cells. Surprisingly, RUNX2 silencing augmented SAHA-dependent cell death of MiaPaCa-2 cells and caused a significant reduction of mutant p53. Consistent with these observations, overexpression of RUNX2 in MiaPaCa-2 cells restored SAHA-mediated decrease in cell viability and increased the amount of mutant p53. Thus, it is suggestive that there exists a positive auto-regulatory loop between RUNX2 and mutant p53, which might amplify their pro-oncogenic signals. Intriguingly, knockdown of mutant p53 or RUNX2 potentiated SAHA-induced up-regulation of TAp63. Indeed, SAHA-stimulated cell death of MiaPaCa-2 cells was partially attenuated by p63 depletion. Collectively, our present observations strongly suggest that RUNX2/mutant p53/TAp63-regulatory axis is one of the key determinants of SAHA sensitivity of p53-mutated pancreatic cancer cells.

LncRNA ANCR down-regulation promotes TGF-β-induced EMT and metastasis in breast cancer

Epithelial to mesenchymal transition (EMT) is a progression of cellular plasticity critical for development, differentiation, cancer cells migration and tumor metastasis. As a well-studied factor, TGF-β participates in EMT and involves in physiological and pathological functions of tumor progression. Accumulating evidence indicates that long noncoding RNAs(lncRNAs) play crucial roles in EMT and tumor metastasis. Here, we find that lncRNA ANCR participates in TGF-β1-induced EMT. By our ChIP and Real-time PCR assays, we reveal that TGF-β1 down-regulates ANCR expression by increasing HDAC3 enrichment at ANCR promoter region, which decreases both H3 and H4 acetylation of ANCR promoter. In addition, by western blot and transwell assays, we indicate that ectopic expression of ANCR partly attenuates the TGF-β1-induced EMT. Downstream, ANCR inhibits breast cancer cell migration and breast cancer metastasis by decreasing RUNX2 expression in vitro and in vivo. Thus, our study identifies ANCR, as a new TGF-β downstream molecular, is essential for TGF-β1-induced EMT by decreasing RUNX2 expression. These results implicate that ANCR might become a prognostic biomarker and an anti-metastasis therapy target for breast cancer.

FPR2 promotes invasion and metastasis of gastric cancer cells and predicts the prognosis of patients

Formyl peptide receptor 2 (FPR2), a classical chemoattractant receptor of G-protein-coupled receptors, is reported to be involved in invasion and metastasis of some cancers, but the role of FPR2 in gastric cancer (GC) has not yet been elucidated. In this study, we found that the levels of FPR2 expression in GC were positively correlated with invasion depth, lymph node metastasis and negatively correlated with the patients’ overall survival. Multivariate analysis indicated that FPR2 expression was an independent prognostic marker for GC patients. FPR2-knockdown significantly abrogated the migration and invasion stimulated by Hp(2–20) and Ac(2–26), two well-characterized ligands for FPR2 in GC cells. FPR2 deletion also reduced the tumorigenic and metastatic capabilities of GC cells in vivo. Mechanistically, stimulation with FPR2 ligands resulted in down-regulation of E-cadherin and up-regulation of vimentin, which were reversed by FPR2 knock-down, implying the involvement of epithelial–mesenchymal transition (EMT). Moreover, the activation of FPR2 was accompanied with ERK1/2 phosphorylation, which could be attenuated by FPR2 silencing or treatment with MEK inhibitor, PD98059. Altogether, our results demonstrate that FPR2 is functionally involved in invasion and metastasis, and potentially acts as a novel prognostic marker as well as a potential therapeutic target in human GC.

Inhibition of CXCL12/CXCR4 axis as a potential targeted therapy of advanced gastric carcinoma

The whole outcome for patients with gastric carcinoma (GC) is very poor because most of them remain metastatic disease during survival even at diagnosis or after surgery. Despite many improvements in multiple strategies of chemotherapy, immunotherapy, and targeted therapy, exploration of novel alternative therapeutic targets is still warranted. Chemokine receptor 4 (CXCR4) and its chemokine ligand 12 (CXCL12) have been identified with significantly elevated levels in various malignancies including GC, which correlates with the survival, proliferation, angiogenesis, and metastasis of tumor cells. Increasing experimental evidence suggests an implication of inhibition of CXCL12/CXCR4 axis as a promising targeted therapy, although there are rare trials focused on the therapeutic efficacy of CXCR4 inhibitors in GC until recently. Therefore, it is reasonable to infer that specific antagonists or antibodies targeting CXCL12/CXCR4 axis alone or combined with chemotherapy will be effective and worthy of further translational studies as a potential treatment strategy in advanced GC.

Regorafenib inhibited gastric cancer cells growth and invasion via CXCR4 activated Wnt pathway

AIM

Regorafenib is an oral small-molecule multi kinase inhibitor. Recently, several clinical trials have revealed that regorafenib has an anti-tumor activity in gastric cancer. However, only part of patients benefit from regorafenib, and the mechanisms of regorafenib's anti-tumor effect need further demonstrating. In this study, we would assess the potential anti-tumor effects and the underlying mechanisms of regorafenib in gastric cancer cells, and explore novel biomarkers for patients selecting of regorafenib.

METHODS

The anti-tumor effects of regorafenib on gastric cancer cells were analyzed via cell proliferation and invasion. The underlying mechanisms were demonstrated using molecular biology techniques.

RESULTS

We found that regorafenib inhibited cell proliferation and invasion at the concentration of 20μmol/L and in a dose dependent manner. The anti-tumor effects of regorafenib related to the decreased expression of CXCR4, and elevated expression and activation of CXCR4 could reverse the inhibition effect of regorafenib on gastric cancer cells. Further studies revealed that regorafenib reduced the transcriptional activity of Wnt/β-Catenin pathway and led to decreased expression of Wnt pathway target genes, while overexpression and activation of CXCR4 could attenuate the inhibition effect of regorafenib on Wnt/β-Catenin pathway.

CONCLUSIONS

Our findings demonstrated that regorafenib effectively inhibited cell proliferation and invasion of gastric cancer cells via decreasing the expression of CXCR4 and further reducing the transcriptional activity of Wnt/β-Catenin pathway.

Relationship between RUNX1 and AXIN1 in ER-negative versus ER-positive Breast Cancer

RUNX1 plays opposing roles in breast cancer: a tumor suppressor in estrogen receptor-positive (ER⁺) disease and an oncogenic role in ER-negative (ER^-) tumors. Potentially mediating the former, we have recently reported that RUNX1 prevents estrogen-driven suppression of the mRNA encoding the tumor suppressor AXIN1. Accordingly, AXIN1 protein expression was diminished upon RUNX1 silencing in ER⁺ breast cancer cells and was positively correlated with AXIN1 protein expression across tumors with high levels of ER. Here we report the surprising observation that RUNX1 and AXIN1 proteins are strongly correlated in ER^- tumors as well. However, this correlation is not attributable to regulation of AXIN1 by RUNX1 or vice versa. The unexpected correlation between RUNX1, playing an oncogenic role in ER^- breast cancer, and AXIN1, a well-established tumor suppressor hub, may be related to a high ratio between the expression of variant 2 and variant 1 (v2/v1) of AXIN1 in ER^- compared with ER⁺ breast cancer. Although both isoforms are similarly regulated by RUNX1 in estrogen-stimulated ER⁺ breast cancer cells, the higher v2/v1 ratio in ER^- disease is expected to weaken the tumor suppressor activity of AXIN1 in these tumors.

Runx3 in Immunity, Inflammation and Cancer

In this chapter we summarize the pros and cons of the notion that Runx3 is a major tumor suppressor gene (TSG). Inactivation of TSGs in normal cells provides a viability/growth advantage that contributes cell-autonomously to cancer. More than a decade ago it was suggested that RUNX3 is involved in gastric cancer development, a postulate extended later to other epithelial cancers portraying RUNX3 as a major TSG. However, evidence that Runx3 is not expressed in normal gastric and other epithelia has challenged the RUNX3-TSG paradigm. In contrast, RUNX3 is overexpressed in a significant fraction of tumor cells in various human epithelial cancers and its overexpression in pancreatic cancer cells promotes their migration, anchorage-independent growth and metastatic potential. Moreover, recent high-throughput quantitative genome-wide studies on thousands of human samples of various tumors and new investigations of the role of Runx3 in mouse cancer models have unequivocally demonstrated that RUNX3 is not a bona fide cell-autonomous TSG. Importantly, accumulating data demonstrated that RUNX3 functions in control of immunity and inflammation, thereby indirectly influencing epithelial tumor development.

WWOX inhibits the invasion of lung cancer cells by downregulating RUNX2

The WW domain-containing oxidoreductase (WWOX) is a tumor suppressor that is lost or decreased in most human tumors. The role of WWOX in human lung carcinoma invasion is still not clear. This study aimed to elucidate the potential role of WWOX in lung cancer cell invasion. WWOX mRNA levels in human lung cancers and lung cancer cell lines were assayed by quantitative real-time PCR. WWOX in lung cancer cell lines was manipulated by transfection of expression vector or small interfering RNA. Cell migration and invasion were assessed by wound healing and/or transwell migration and invasion assays. The protein levels of WWOX, E-cadherin and RUNX2 were analyzed by western blot or immunofluorescence. WWOX expression is inversely correlated to invasiveness of lung cancer. WWOX overexpression in highly invasive H1299 cells reduced cell motility and invasiveness, and inhibited the expression of RUNX2 and its target gene matrix metalloproteinase-9 (MMP-9). Silencing WWOX in less invasive NL9980 cells resulted in opposite effects. Overexpressing RUNX2 in H1299 or silencing RUNX2 in NL9980 cells reversed the effects of WWOX. These results suggested that WWOX inhibited the invasive phenotype of lung cancer through downregulating the expression of RUNX2.