MicroRNA-127 is a tumor suppressor in human esophageal squamous cell carcinoma through the regulation of oncogene FMNL3

FMNL3 Promotes Migration and Invasion of Breast Cancer Cells via Inhibiting Rad23B-Induced Ubiquitination of Twist1

Breast cancer is a heterogeneous malignant tumor, and its high metastasis rate depends on the abnormal activation of cell dynamics. Formin-like protein 3 (FMNL3) plays an important role in the formation of various cytoskeletons that participate in cell movement. The objective of this study was to explore the function of FMNL3 in breast cancer progression and endeavor to reveal the molecular mechanism of this phenomenon. We found that FMNL3 was abnormally highly expressed in aggressive breast cancer cells and tissues, and it significantly inhibited E-cadherin expression. FMNL3 could specifically interact with Twist1 rather than other epithelial-mesenchymal transition transcription factors (EMT-TFs). We also found that FMNL3 enhanced the repressive effect of Twist1 on CDH1 transcription in breast cancer cells. Further mechanism studies showed that FMNL3 suppressed the ubiquitin degradation of Twist1 by inhibiting the interaction between Twist1 and Rad23B, the ubiquitin transfer protein of Twist1. In vitro functional experiments, it was confirmed that FMNL3 promoted the migration and invasion of breast cancer cells by regulating Twist1. Furthermore, Twist1 could directly bind to the fmnl3 promoter to facilitate FMNL3 transcription. To conclude, this study indicated that FMNL3 acted as a pro-metastasis factor in breast cancer by promoting Twist1 stability to suppress CDH1 transcription.

circALPL Sponges miR-127 to Promote Gastric Cancer Progression by Enhancing MTDH Expression

Background: CircRNA plays an important role in cancer progression. However, the potential mechanism of circRNA in gastric cancer remains unknown. In this study, we aimed to investigate the specific mechanism of circALPL in gastric cancer. Methods: Using a high-throughput microarray, we found that circALPL was upregulated in gastric cancer cell lines. RT-qPCR was used to measure the circALPL expression level in gastric cell lines and tissue. Transwell, CCK-8, and metastasis assays were performed to learn the function after circALPL was inhibited. Results: circALPL downregulation suppresses the invasion and proliferation ability of gastric cancer cells. Additionally, the underlying pathway of circALPL was studied using luciferase reporter assays and RNA immunoprecipitation assays. The results showed that circALPL promotes gastric cancer progression by sponging miR-127, thus upregulating MTDH. Conclusion: The circALPL-miR-127-MTDH pathway plays a vital role in gastric cancer proliferation and metastasis. circALPL might be a new therapeutic target in gastric cancer.

Transcriptomic and microRNA Expression Profiles Identify Biomarkers for Predicting Neo-Chemoradiotherapy Response in Esophageal Squamous Cell Carcinomas (ESCC)

Neo-chemoradiotherapy (nCRT) before surgery is a standard treatment for locally advanced esophageal cancers. However, the treatment outcome of nCRT varied with different patients. This study aimed to identify potential biomarkers for prediction of nCRT-response in patients with esophageal squamous cell carcinoma (ESCC). Microarray datasets of nCRT responder and non-responder samples (access number GSE45670 and GSE59974) of patients with ESCC were downloaded from Gene Expression Omnibus (GEO) database. The mRNA expression profiles of cancer biopsies from four ESCC patients were analyzed before and after nCRT. Differentially expressed genes (DEGs) and miRNAs were screened between nCRT responder and non-responder ESCC samples. Functional enrichment analysis was conducted for these DEGs followed by construction of protein-protein interaction (PPI) network and miRNA-mRNA regulatory network. Finally, univariate survival analysis was performed to identify candidate biomarkers with prognostic values in ESCC. We identified numerous DEGs and differentially expressed miRNAs from nCRT responder group. GO and KEGG analysis showed that the dysregulated genes were mainly involved in biological processes and pathways, including "response to stimulus", "cellular response to organic substance", "regulation of signal transduction", "AGE-RAGE signaling pathway in diabetic complications", and "steroid hormone biosynthesis". After integration of PPI network and miRNA-mRNA network analysis, we found eight genes, TNF, AKR1C1, AKR1C2, ICAM1, GPR68, GNB4, SERPINE1 and MMP12, could be candidate genes associated with disease progression. Univariate cox regression analysis showed that there was no significant correlation between dysregulated miRNAs (such as hsa-miR-34b-3p, hsa-miR-127-5p, hsa-miR-144-3p, and hsa-miR-486-5p, et al.) and overall survival of ESCC patients. Moreover, abnormal expression of MMP12 was significantly correlated with pathological degree, TNM stage, lymph nodes metastasis, and overall survival of ESCC patients (p < 0.05). Taken together, our study identified that MMP12 might be a useful tumor biomarker and therapeutic target for ESCC.

MicroRNA Profile for Diagnostic and Prognostic Biomarkers in Thyroid Cancer

The challenge in managing thyroid nodules is to accurately diagnose the minority of those with malignancy. We aimed to identify diagnostic and prognostic miRNA markers for thyroid nodules. In a discovery cohort, we identified 20 candidate miRNAs to differentiate between noninvasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP) and papillary thyroid carcinomas (PTC) by using the high-throughput small RNA sequencing method. We then selected three miRNAs (miR-136, miR-21, and miR-127) that were differentially expressed between the PTC follicular variant and other variants in The Cancer Genome Atlas data. High expression of three miRNAs differentiated thyroid cancer from nonmalignant tumors, with an area under curve (AUC) of 0.76-0.81 in an independent cohort. In patients with differentiated thyroid cancer, the high-level expression of the three miRNAs was an independent indicator for both distant metastases and recurrent or persistent disease. In patients with PTC, a high expression of miRNAs was associated with an aggressive histologic variant, extrathyroidal extension, distant metastasis, or recurrent or persistent disease. Three miRNAs may be used as diagnostic markers for differentiating thyroid cancers from benign tumors and tumors with extremely low malignant potential (NIFTP), as well as prognostic markers for predicting the risk of recurrent/persistent disease for differentiated thyroid cancer.

Identification of key differentially expressed mRNAs and microRNAs in non-small cell lung cancer using bioinformatics analysis

Non-small cell lung cancer (NSCLC) is a leading cause of mortality worldwide. However, the pathogenesis of NSCLC remains to be fully elucidated. Therefore, the present study aimed to explore the differential expression of mRNAs and microRNAs (miRNAs/miRs) in NSCLC and to determine how these RNA molecules interact with one another to affect disease progression. Differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) were identified from the GSE18842, GSE32863 and GSE29250 datasets downloaded from the Gene Expression Omnibus (GEO database). Functional and pathway enrichment analysis were performed based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. STRING, Cytoscape and MCODE were applied to construct a protein-protein interaction (PPI) network and to screen hub genes. The interactions between miRNAs and mRNAs were predicted using miRWalk 3.0 and a miRNA-mRNA regulatory network was constructed. The prognostic value of the identified hub genes was then evaluated via Kaplan-Meier survival analyses using datasets from The Cancer Genome Atlas. A total of 782 DEGs and 46 DEMs were identified from the 3 GEO datasets. The enriched pathways and functions of the DEGs and target genes of the DEMs included osteoclast differentiation, cell adhesion, response to a drug, plasma membrane, extracellular exosome and protein binding. A subnetwork composed of 11 genes was extracted from the PPI network and the genes in this subnetwork were mainly involved in the cell cycle, cell division and DNA replication. A miRNA-gene regulatory network was constructed with 247 miRNA-gene pairs based on 6 DEMs and 210 DEGs. Kaplan-Meier survival analysis indicated that the expression of ubiquitin E2 ligase C, cell division cycle protein 20, DNA topoisomerase IIα, aurora kinase A and B, cyclin B2, maternal embryonic leucine zipper kinase, slit guidance ligand 3, phosphoglucomutase 5, endomucin, cysteine dioxygenase type 1, dihydropyrimidinase-like 2, miR-130b, miR-1181 and miR-127 was significantly associated with overall survival of patients with lung adenocarcinoma. In the present study, a miRNA-mRNA regulatory network in NSCLC was established, which may provide future avenues for scientific exploration and therapeutic targeting of NSCLC.

microRNA-144 inhibits cell proliferation and invasion by directly targeting TIGAR in esophageal carcinoma

microRNAs (miRNAs) have been identified to play vital roles in the development and progression of numerous different types of human malignancy, including esophageal squamous cell carcinoma (ESCC). In the present study, the biological function of microRNA-144 (miR-144) was investigated, as well as its underlying molecular mechanism in ESCC. The results revealed that miR-144 expression was significantly decreased, whereas the expression of TP53-inducible glycolysis and apoptosis regulator (TIGAR) was significantly increased in human ESCC tissues when compared with adjacent non-tumor tissues. An increase in TIGAR was significantly associated with tumor size and Tumor-Node-Metastasis staging in patients. Functional analysis revealed that the overexpression of miR-144 using lentivirus particles significantly inhibited cell proliferation and tumor colony formation, and induced cell apoptosis in EC9706 and EC109 cells. The autophagy activity was also enhanced by miR-144 activity. In addition, overexpression of miR-144 significantly inhibited tumor growth in vivo. In the present study, TIGAR was confirmed to be the downstream target of miR-144 in ESCC. siRNA-mediated downregulation of TIGAR inversely regulated the inhibition effect of miR-144 on ESCC cells. To conclude, the present study demonstrated that miR-144 inhibits proliferation and invasion in esophageal cancer by directly targeting TIGAR.

MicroRNA-127 Inhibits the Progression of Melanoma by Downregulating Delta-Like Homologue 1

Objective

Melanoma is the most common form of skin cancer with low survival rate and poor prognosis. MicroRNAs (miRNAs) have been reported to play essential roles in progression of melanoma. However, the role and mechanism of miR-127 in the process of melanoma remain poorly understood.

Methods

The expressions of miR-127 and delta-like homologue 1 (DLK1) were measured in melanoma tissues and cells by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Cell proliferation and apoptosis were measured by MTT assay, flow cytometry, and Western blot. The interaction between miR-127 and DLK1 was investigated by bioinformatics analysis, luciferase activity assay, and RNA immunoprecipitation (RIP). Murine xenograft model was conducted to investigate the effect of miR-127 on tumor growth in vivo.

Results

miR-127 was inhibited and DLK1 mRNA was enhanced in melanoma tissues and cells. Low abundance of miR-127 in melanoma tissues predicted a poor prognosis and was associated with the malignant clinicopathological features. Overexpression of miR-127 inhibited cell proliferation and induced apoptosis in melanoma cells. Moreover, DLK1 was targeted by miR-127 and its restoration reversed the regulatory effect of miR-127 on the process of melanoma. Besides, the addition of miR-127 suppressed xenograft tumor growth via suppressing DLK1 protein level in nude mice.

Conclusion

miR-127 blocked the development of melanoma by targeting DLK1, providing a novel biomarker for the treatment of melanoma.

Tumor Suppressor Function of miR-127-3p and miR-376a-3p in Osteosarcoma Cells

Since the introduction of high-dose chemotherapy about 35 years ago, survival rates of osteosarcoma patients have not been significantly improved. New therapeutic strategies replacing or complementing conventional chemotherapy are therefore urgently required. MicroRNAs represent promising targets for such new therapies, as they are involved in the pathology of multiple types of cancer, and aberrant expression of several miRNAs has already been shown in osteosarcoma. In this study, we identified silencing of miR-127-3p and miR-376a-3p in osteosarcoma cell lines and tissues and investigated their role as potential tumor suppressors in vitro and in vivo. Transfection of osteosarcoma cells (n = 6) with miR-127-3p and miR-376a-3p mimics significantly inhibited proliferation and reduced the colony formation capacity of these cells. In contrast, we could not detect any influence of miRNA restoration on cell cycle and apoptosis induction. The effects of candidate miRNA restoration on tumor engraftment and growth in vivo were analyzed using a chicken chorioallantoic membrane (CAM) assay. Cells transfected with mir-127-3p and miR-376a-3p showed reduced tumor take rates and tumor volumes and a significant decrease of the cumulative tumor volumes to 41% and 54% compared to wildtype cells. The observed tumor suppressor function of both analyzed miRNAs indicates these miRNAs as potentially valuable targets for the development of new therapeutic strategies for the treatment of osteosarcoma.

A Novel Bioengineered miR-127 Prodrug Suppresses the Growth and Metastatic Potential of Triple-Negative Breast Cancer Cells

miR-127 is downregulated in breast cancer, where it has been shown to suppress the proliferation, migration, and invasion of breast cancer cells. In triple-negative breast cancer (TNBC), miR-127 downregulation correlates with decreased disease-free and overall patient survival. Tumor suppressor miRNAs may hold therapeutic promise but progress has been limited by several factors, including the lability and high cost of miRNA mimics. Here, we take a novel approach to produce a miR-127 prodrug (miR-127^PD), which we demonstrate is processed to mature, functional miR-127-3p in TNBC tumor cells. miR-127^PD decreased the viability and motility of TNBC cells, sensitized TNBC cells to chemotherapy, and restricted the TNBC stem cell population. Furthermore, systemic delivery of miR-127^PD suppressed tumor growth of MDA-MB-231 and MDA-MB-468 TNBC cells and spontaneous metastasis of MDA-MB-231 cells. In addition, CERK, NANOS1, FOXO6, SOX11, SOX12, FASN, and SUSD2 were identified as novel, functionally important targets of miR-127. In conclusion, our study demonstrates that miR-127 functions as a tumor and metastasis suppressor in TNBC and that delivery of miR-127 may hold promise as a novel therapy. SIGNIFICANCE: Exogenous administration of miR-127, which is functionally activated in target cells, inhibits growth and spontaneous metastasis of triple-negative breast cancer.

An alcohol-soluble polysaccharide from Atractylodes macrocephala Koidz induces apoptosis of Eca-109 cells

In this study, polysaccharides from Atractylodes macrocephala Koidz (APA) which were soluble in alcohol were prepared, purified, analyzed the structure and investigated the antitumor activity in vitro cell experiment. Results of high-performance gel permeation chromatography (HPGPC), fourier-transform infrared spectroscopy (FT-IR), and gas chromatography (GC) showed that APA was a 2.1KDa neutral hetero polysaccharide composed of arabinose and glucose (molar ratio, 1.00:4.57) with pyranose rings and α-type and β-type glycosidic linkages. Results by MTT experiments showed that the proliferation inhibition was 74.63% in Eca109 cells treated with 2 mg/mL dose of APA. Annexin V/PI assay, Hoechst 33,258 staining, cell cycle distribution, rhodamine 123 dye assay and western blot assay clarified that APA could accelerate the apoptosis of Eca109 cells by mitochondrial pathway and stocked cells at S phase. These data indicated that APA is a promising potential candidate for therapeutic treatment of esophageal cancer.

Hsa-mir-127 impairs survival of patients with glioma and promotes proliferation, migration and invasion of cancerous cells by modulating replication initiator 1

This work aimed to investigate the inter-regulatory functions of hsa-mir-127 and replication initiator 1 (REPIN1) on the proliferation and metastasis of glioma cells. The in-silico data on the implication of hsa-mir-127 and REPIN1 in glioma were retrieved from The Cancer Genome Atlas (TCGA). The expression levels of hsa-mir-127 and REPIN1 mRNA were determined by qRT-PCR, whereas Western blot was used to detect REPIN1 protein expression in glioma cell lines. The proliferation of glioma cells was determined by means of the MTT assay, whereas the transwell assay was employed for assessing the extent of cell migration and invasion. The interaction among REPIN1 and hsa-mir-127 was checked using the luciferase reporter assay. The expression of hsa-mir-127 was markedly increased in clinical data obtained from TCGA and in glioma cells compared with normal tissues and control cells, respectively. Increased expression of hsa-mir-127 and decreased expression of REPIN1 were both associated with poor overall survival. Moreover, hsa-mir-127 overexpression noticeably promoted proliferation, inhibited apoptosis and increased the invasive and migratory capacities of glioma cells. Inverse effects were found with hsa-mir-127 antisense inhibitor. Interestingly, overexpression of hsa-mir-127 downregulated REPIN1 expression, and luciferase reporter assay showed that the tumorigenesis effect of hsa-mir-127 requires, in part, its direct targeting of REPIN1. In conclusion, the hsa-mir-127/REPIN1 pathway is involved in gliomas and could be a potential therapeutic target.

MicroRNA-127-3p controls murine hematopoietic stem cell maintenance by limiting differentiation

The balance between self-renewal and differentiation is crucial to ensure the homeostasis of the hematopoietic system, and is a hallmark of hematopoietic stem cells. However, the underlying molecular pathways, including the role of micro-RNA, are not completely understood. To assess the contribution of micro-RNA, we performed micro-RNA profiling of hematopoietic stem cells and their immediate downstream progeny multi-potent progenitors from wild-type control and Pbx1-conditional knockout mice, whose stem cells display a profound self-renewal defect. Unsupervised hierarchical cluster analysis separated stem cells from multi-potent progenitors, suggesting that micro-RNA might regulate the first transition step in the adult hematopoietic development. Notably, Pbx1-deficient and wild-type cells clustered separately, linking micro-RNAs to self-renewal impairment. Differential expression analysis of micro-RNA in the physiological stem cell-to-multi-potent progenitor transition and in Pbx1-deficient stem cells compared to control stem cells revealed miR-127-3p as the most differentially expressed. Furthermore, miR-127-3p was strongly stem cell-specific, being quickly down-regulated upon differentiation and not re-expressed further downstream in the bone marrow hematopoietic hierarchy. Inhibition of miR-127-3p function in Lineage-negative cells, achieved through a lentiviral-sponge vector, led to severe stem cell depletion, as assessed with serial transplantation assays. miR-127-3p-sponged stem cells displayed accelerated differentiation, which was uncoupled from proliferation, accounting for the observed stem cell reduction. miR-127-3p overexpression in Lineage-negative cells did not alter stem cell pool size, but gave rise to lymphopenia, likely due to lack of miR-127-3p physiological downregulation beyond the stem cell stage. Thus, tight regulation of miR-127-3p is crucial to preserve the self-renewing stem cell pool and homeostasis of the hematopoietic system.

miR-127 suppresses gastric cancer cell migration and invasion via targeting Wnt7a

Gastric cancer (GC) is a malignant tumor originating from the mucosal epithelium of the stomach. Patients suffering from this disease may have occurrence of residual GC due to delay in diagnosis and treatment. In addition, abnormal expression of microRNAs (miRNAs) is involved in GC progression. Therefore, we examined the underlying mechanism of miR-127 in GC. The expression of miR-127 and Wnt7a was examined in GC using RT-qPCR and western blot analysis. A Transwell assay was used to assess the ability of GC cell migration and invasion. Luciferase reporter assay was used to verify the specific target of miR-127 in GC. The results showed miR-127 expression was lower in GC than normal samples, while Wnt7a expression was detected at a higher level in GC than normal samples. The association between miR-127 and Wnt7a expression was negatively correlated in GC tissues. miR-127 mimic in the two GC cell lines markedly curbed cell migration and invasion, while inhibition of miR-127 showed the opposite effect. In addition, Wnt7a siRNA significantly inhibited GC cell migration and invasion and Wnt7a was verified as a specific target of miR-127 in GC cells. Wnt7a reversed the ability of GC cell migration and invasion regulated by miR-127. In conclusion, miR-127 could curb GC cell migration and invasion by upregulating Wnt7a, indicating its potential application in GC diagnosis and therapy.

Formin-like 3 regulates RhoC/FAK pathway and actin assembly to promote cell invasion in colorectal carcinoma

AIM

To clarify the underlying mechanism of formin-like 3 (FMNL3) in the promotion of colorectal carcinoma (CRC) cell invasion.

METHODS

The in vitro biological function analyses of FMNL3 were performed by gain- and loss-of function approaches. Changes in the F-actin cytoskeleton were detected by the technologies of phalloidin-TRITC labeling and confocal microscopy. The signaling pathway mediated by FMNL3 was explored by western blot, gelatin zymograph assay, co-immunoprecipitation (co-IP), immunofluorescence co-localization, and glutathione S-transferase (GST) pull-down assay.

RESULTS

The in vitro experimental results showed that FMNL3 significantly promoted the proliferation, invasion, and migration of CRC cells (P < 0.05 and P < 0.01). Moreover, FMNL3 regulated the remodeling of actin-based protrusions such as filopodia and lamellipodia in a RhoC-dependent manner. The western blot and gelatin zymograph assay results indicated that FMNL3 was involved in the RhoC/ focal adhesion kinase (FAK) pathway and acted as an effector of RhoC to activate the downstream signaling of p-FAK as well as p-MAPK and p-AKT. This resulted in the increased expression of matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9) and vascular endothelial growth factor (VEGF), and the subsequent promotion of CRC cell invasion. The results of TAE226, U0126 or Ly294002 treatment confirmed an essential role of FMNL3 in activation of the RhoC/FAK pathway and the subsequent promotion of CRC invasion. Co-IP, co-localization and GST pull-down assays showed the direct interaction of FMNL3 with RhoC in vivo and in vitro.

CONCLUSION

FMNL3 regulates the RhoC/FAK signaling pathway and RhoC-dependent remodeling of actin-based protrusions to promote CRC invasion.

The mechanism study of miR-125b in occurrence and progression of multiple myeloma

Although many efforts have contributed to improve our knowledge of molecular pathogenesis about multiple myeloma (MM), the role and significance of microRNAs and long noncoding RNAs in MM cells, along with the core mechanism remains virtually absent. The mRNA levels of miR-125b and MALAT1 in MM cell lines were detected by qRT-PCR. The influence of Lenti-Sh-miR-125b on cell viability and the Notch-1 pathway-related proteins were assessed by MTT method and western blot, respectively. We also investigated the regulation effect between MALAT1 and Notch1 pathway. Moreover, the connection between Notch1 signaling and MM cell growth was discussed in-depth. The reverse effect of pcDNA-Notch1 on the cell viability and Notch-1 pathway proteins induced by Si-MALAT1 was also studied. Furthermore, miR-125b overexpressing MM cell lines were injected subcutaneously into nude mice. MiR-125b and MALAT1 were inversely expressed in MM cell lines. Lenti-Sh-miR-125b inhibited the expression of MALAT1 and Notch-1 protein. Binding sites were confirmed between miR-125b and MALAT1, and silencing MALAT1 did not alter the expression of Notch-1. The apoptosis rate was increased and the survival rate was decreased obviously in GSI XII (targeted cleavage of Notch-1 receptor) group, along with the inhibited Notch1 and HES1 proteins. Moreover, the decreased cell viability and Notch-1 pathway proteins induced by Si-MALAT1 could be reversed by pcDNA-Notch1. Lenti-Sh-miR-125b promoted survival and decreased Notch1 and HES1 proteins levels, while this effect was reversed by si -MALAT1. MiR-125b regulated MALAT1 expression via Notch1 signaling pathway to regulate cell growth, thus participating in the occurrence and progression of MM, which functioned as a therapeutic target for tracking MM.

miR-486 functions as a tumor suppressor in esophageal cancer by targeting CDK4/BCAS2

Esophageal cancer is a common tumor for which morbidity and mortality are high worldwide. We aimed to study alterations in miR-486 expression in esophageal cancers, and the effect miR-486 on esophageal cancer cell function and behavior. We collected esophageal cancer tissues/corresponding normal tissues from 20 patients and utilized three esophageal cancer cell lines and normal esophageal epithelial cells, and the expression of miR-486, CDK4 and BCAS2 was detected by qRT-PCR. Western blotting was used to detect the expression of CDK4 and BCAS2 protein. Then, we overexpressed miR-486 in esophageal cancer cell line EC9706. A series of cell functional analyses, including cell growth, cell cycle, apoptosis, migration and invasion were performed in esophageal cancer cells using colony formation assay, flow cytometry, Transwell and scratch assays, respectively. Dual-Luciferase reporter gene assay was used to detect the target genes of miR-486. We found that the expression of miR-486 in esophageal cancer tissues and cell lines was significantly lower than that in the normal tissues and normal esophageal epithelial cell line. Overexpression of miR-486 significantly inhibited the colony formation ability, induced G0/G1 phase arrest and apoptosis and suppressed cell migration and invasion in the EC9706 cells. Using bioinformatics and luciferase reporter assay, we identified that CDK4 and BCAS2 may be target genes of miR-486 and levels of CDK4 and BCAS2 were both significantly higher in the esophageal cancer tissues and cell lines than levels in the normal tissues and cells. Furthermore, knockdown of CDK4/BCAS2 coincided with the suppressive effects of miR-486 in esophageal cancer cells. Expression of apoptotic signaling molecules p21 and caspase-3 was upregulated in the CDK4/BCAS2-knockdown groups. These results suggest that miR-486 may suppress tumor cell growth and metastasis in esophageal cancer by targeting CDK4/BCAS2. The newly identified miR-486/CDK4/BCAS2 pathway provides further insight into the development and progression of esophageal cancer, which is of great significance to the early diagnosis and detection of esophageal cancer.

PDX1: A Unique Pancreatic Master Regulator Constantly Changes Its Functions during Embryonic Development and Progression of Pancreatic Cancer

Multifunctional activity of the PDX1 gene product is reviewed. The PDX1 protein is unique in that being expressed exclusively in the pancreas it exhibits various functional activities in this organ both during embryonic development and during induction and progression of pancreatic cancer. Hence, PDX1 belongs to the family of master regulators with multiple and often antagonistic functions.

MiR-127 and miR-376a act as tumor suppressors by in vivo targeting of COA1 and PDIA6 in giant cell tumor of bone

Giant cell tumors of bone (GCTB) are generally benign bone tumors associated with expansive osteolytic defects, a high rate of recurrence and potential malignant transformation. We recently observed silencing of miR-127-3p and miR-376a-3p in GCTB and identified COA1 and PDIA6 as their target genes. Here, we investigate the impact of these microRNAs and their target genes on tumor engraftment and progression of giant cell tumor stromal cells (GCTSC) in vivo by xenotransplantation on the chorioallantoic membrane of chicken eggs. Prior to transplantation, the neoplastic GCTSCs were transfected with miRNA mimics or siRNAs directed against their target genes. Restoration of miR-127-3p and miR-376a-3p reduced the tumor take rate to 17% and 47% compared to 95% in the controls. The tumor volumes were significantly reduced to 29% by both miRNAs. Silencing of COA1 and PDIA6 significantly decreased the tumor volumes to 37.7% and 42.7%, while the tumor take rates remained stable. Our results indicate that re-expression of miR-127-3p and miR-376a-3p induces a strong tumor suppressor effect in GCTSC, which is partially mediated via COA1 and PDIA6.

MicroRNA-381 enhances radiosensitivity in esophageal squamous cell carcinoma by targeting X-linked inhibitor of apoptosis protein

Background

Increasing evidence indicates that radioresistance remains a major problem in the treatment of patients with esophageal squamous cell carcinoma (ESCC). This study was designed to investigate the expression of microRNA-381 (miR-381) and its function in the radioresistance of ESCC.

Methods

In this study, miR-381 expression was first detected in ESCC cell lines and tissue samples by quantitative real-time polymerase chain reaction (qRT-PCR). Then, the effects of miR-381 expression on growth, apoptosis, and radiosensitivity of ESCC cells were analyzed by MTT, colony formation, and flow cytometry, respectively. Dual-luciferase reporter assays were performed to validate the regulation of a putative target of miR-381, in corroboration with qRT-PCR and Western blotting assays.

Results

ESCC cell lines or tissues were found to express significantly lower miR-381 than normal esophageal epithelial cells or adjacent normal tissues, respectively. Ectopic expression of miR-381 in ESCC cell lines blocked proliferation, reduced colony formation, enhanced apoptosis, and increased radiosensitivity by enhancing irradiation-induced apoptosis. In addition, dual-luciferase reporter assays showed that miR-381 binds to the 3′-untranslated region of X-linked inhibitor of apoptosis protein (XIAP), suggesting that XIAP should be a direct target of miR-381. Re-expression of miR-381 suppressed XIAP protein expression in ESCC cells, and the effects of miR-381 upregulation on ESCC cells were found to be similar with silencing of XIAP. In addition, XIAP mRNA expression significantly increased in ESCC tissues and was inversely correlated with miR-381 expression.

Conclusion

The results of this study suggest that miR-381/XIAP pathway contributed to the growth inhibition, increase in apoptosis, and enhancement of radiosensitivity in ESCC cells Therefore, miR-381 may be a potential therapeutic target in human ESCC.