miR-29c suppresses pancreatic cancer liver metastasis in an orthotopic implantation model in nude mice and affects survival in pancreatic cancer patients

The potential of miR-29 in modulating tumor angiogenesis: a comprehensive review

MicroRNAs (miRNAs) are a class of short non-coding RNAs that play a crucial role in the post-transcriptional regulation of gene expression. They are associated with various biological processes related to tumors. Among the numerous miRNAs, miR-29 has garnered attention for its role in regulating tumor angiogenesis. In numerous human tumors, miR-29 has been demonstrated to negatively correlate with the capacity for angiogenesis and the degree of malignancy, as well as with the expression levels of pro-angiogenic factors such as vascular endothelial growth factor vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and matrix metalloproteinase (MMP)-2. Multiple studies, utilizing techniques like dual-luciferase reporter assays, have confirmed that miR-29 directly targets the 3'-untranslated region (UTR) of mRNAs for VEGF, PDGF, and MMP-2. Extensive investigations involving tumor cell lines and animal models have shown that the overexpression of miR-29, achieved through miRNA transfection or the introduction of miRNA mimics, effectively inhibits angiogenesis by upregulating these pro-angiogenic factors. Conversely, downregulation of miR-29 using specific inhibitors promotes angiogenesis. While small molecule inhibitors and antibodies targeting VEGF constitute a primary strategy in anti-angiogenesis therapies, miR-29's ability to target multiple pro-angiogenic molecules positions it as a promising candidate for future therapeutic interventions, especially with ongoing advancements in nucleic acid drug design and delivery systems.

Microbiome and MicroRNA or Long Non-Coding RNA-Two Modern Approaches to Understanding Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of humans' most common and fatal neoplasms. Nowadays, a number of PDAC studies are being conducted in two different fields: non-coding RNA (especially microRNA and long non-coding RNA) and microbiota. It has been recently discovered that not only does miRNA affect particular bacteria in the gut microbiome that can promote carcinogenesis in the pancreas, but the microbiome also has a visible impact on the miRNA. This suggests that it is possible to use the combined impact of the microbiome and noncoding RNA to suppress the development of PDAC. Nevertheless, insufficient research has focused on bounding both approaches to the diagnosis, treatment, and prevention of pancreatic ductal adenocarcinoma. In this article, we summarize the recent literature on the molecular basis of carcinogenesis in the pancreas, the two-sided impact of particular types of non-coding RNA and the pancreatic cancer microbiome, and possible medical implications of the discovered phenomenon.

The Roles of MicroRNA in Pancreatic Cancer Progression

Pancreatic Ductal Adenocarcinoma (PDAC) has a poor patient survival rate in comparison with other cancer types, even after targeted therapy, chemotherapy, and immunotherapy. Therefore, a great deal needs to be done to gain a better understanding of the biology and identification of prognostic and predictive markers for the development of superior therapies. The microRNAs (miRNAs) belong to small non-coding RNAs that regulate post-transcriptional gene expression. Several shreds of evidence indicate that miRNAs play an important role in the pathogenesis of pancreatic cancer. Here we review the recent developments in miRNAs and their target role in the development, metastasis, migration, and invasion.

Clinical role of MiRNA 29a and MiRNA 335 on breast cancer management: their relevance to MMP2 protein level

BACKGROUND

Circulating miRNAs are novel biomarkers, authors aimed to investigate the expression level of miR-29a and miR-335 and their relevance to CEA, CA15.3, and matrix metalloproteinase-2 (MMP2).

MATERIALS AND METHODS

Breast cancer (BC) patients (n = 44), benign breast lesion patients (n = 25), and healthy individuals (n = 19) were enrolled for detection of miRNA expression levels, MMP2 and biochemical markers using quantitative polymerase chain reaction (PCR) and ELISA, respectively.

RESULTS

Expression of miR-29a and miR-335 were significantly decreased in breast patients as compared to healthy individuals, while biochemical markers were high in BC patients as compared to the other two groups. The diagnostic efficacy for miR-29a, miR-335, and MMP2 were superior to both CEA and CA 15.3 for early detection of BC patients.

CONCLUSIONS

Detection of the miR-29a and miR335 expression levels in serum samples are significant promising biomarkers for BC diagnosis.

Role of non-coding RNAs in tumor progression and metastasis in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of cancer with an overall 5-year survival rate of less than 10%. The 1-year survival rate of patients with locally advanced or metastatic disease is abysmal. The aggressive nature of cancer cells, hypovascularization, extensive desmoplastic stroma, and immunosuppressive tumor microenvironment (TME) endows PDAC tumors with multiple mechanisms of drug resistance. With no obvious genetic mutation(s) driving tumor progression or metastatic transition, the challenges for understanding the biological mechanism(s) of these processes are paramount. A better understanding of the molecular and cellular mechanisms of these processes could lead to new diagnostic tools for patient management and new targets for therapeutic intervention. microRNAs (miRNAs) are an evolutionarily conserved gene class of short non-coding regulatory RNAs. miRNAs are an extensive regulatory layer that controls gene expression at the posttranscriptional level. This review focuses on preclinical models that functionally dissect miRNA activity in tumor progression or metastatic processes in PDAC. Collectively, these studies suggest an influence of miRNAs and RNA-RNA networks in the processes of epithelial to mesenchymal cell transition and cancer cell stemness. At a cell-type level, some miRNAs mainly influence cancer cell–intrinsic processes and pathways, whereas other miRNAs predominantly act in distinct cellular compartments of the TME to regulate fibroblast and immune cell functions and/or influence other cell types’ function via cell-to-cell communications by transfer of extracellular vesicles. At a molecular level, the influence of miRNA-mediated regulation often converges in core signaling pathways, including TGF-β, JAK/STAT, PI3K/AKT, and NF-κB.

The Role of miRNA in the Pathophysiology of Neuroendocrine Tumors

Neuroendocrine tumors (NETs) represent a tumor group that is both rare and heterogeneous. Prognosis is largely determined by the tumor grading and the site of the primary tumor and metastases. Despite intensive research efforts, only modest advances in diagnostic and therapeutic approaches have been achieved in recent years. For patients with non-respectable tumor stages, prognosis is poor. In this context, the development of novel diagnostic tools for early detection of NETs and prediction of tumor response to therapy as well as estimation of the overall prognosis would greatly improve the clinical management of NETs. However, identification of novel diagnostic molecules is hampered by an inadequate understanding of the pathophysiology of neuroendocrine malignancies. It has recently been demonstrated that microRNA (miRNA), a family of small RNA molecules with an established role in the pathophysiology of quite different cancer entities, may also play a role as a biomarker. Here, we summarize the available knowledge on the role of miRNAs in the development of NET and highlight their potential use as serum-based biomarkers in the context of this disease. We discuss important challenges currently preventing their use in clinical routine and give an outlook on future directions of miRNA research in NET.

Dysregulation of miRNAs Targeting the IGF-1R Pathway in Pancreatic Ductal Adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC), the most prevalent neoplastic lethal pancreatic disease, has a poor prognosis and an increasing incidence. The insulin-like growth factor-1 receptor (IGF-1R) signaling pathway is considered to be a contributing factor to the progression, metastasis, and therapy resistance of PDAC. Currently available treatment options for PDAC are limited, but microRNAs (miRNAs) may represent a new therapeutic strategy for targeting genes involved in the IGF-1R signaling pathway.

METHOD

We investigated the expression levels of 21 miRNAs involved in the IGF-1R signaling pathway in pancreatic tissue from 38 patients with PDAC and 11 controls (five patients with chronic pancreatitis and six patients with normal pancreatic tissue).

RESULTS

We found 19 differentially expressed miRNAs between the PDAC cases and the controls. In particular, miR-100-5p, miR-145-5p, miR-29c-3p, miR-9-5p, and miR-195-5p were exclusively downregulated in PDAC tissue but not in chronic pancreatitis or normal pancreatic tissues; both control types presented similar levels. We also identified miR-29a-3p, miR-29b-3p, and miR-7-5p as downregulated miRNAs in PDAC tissues as compared with normal tissues but not with pancreatitis tissues.

CONCLUSIONS

We identified a panel of miRNAs that could represent putative therapeutic targets for the development of new miRNA-based therapies for PDAC.

The role of autophagy in pancreatic cancer progression

Patients with pancreatic cancer have an abysmal survival rate. The poor prognosis of pancreatic cancer is due to the difficulty of making an early diagnosis, high rate of metastasis, and frequent chemoresistance. In recent years, as a self-regulatory procedure within cells, the effect and mechanism of autophagy have been explored. Dysregulated autophagy serves as a double-edged sword in cancer development in which autophagy inhibits cancer initiation but promotes cancer progression. After tumor formation, activation of autophagy can induce epithelial-mesenchymal transition, regulate metabolism, specifically glutamine usage and the glycolytic process, and mediate drug resistance in pancreatic cancer. Multiple genes, RNA molecules, proteins, and certain drugs exert antitumor effects by inhibiting autophagy-mediated drug resistance. Several clinical trials have combined autophagy inhibitors with chemotherapeutic drugs in pancreatic cancer treatment, some of which have shown promising results. In conclusion, autophagy plays a vital role in pancreatic cancer progression and deserves further study.

MicroRNA-29a functions as a tumor suppressor through targeting STAT3 in laryngeal squamous cell carcinoma

Laryngeal squamous cell carcinoma (LSCC) is a common head and neck cancer with high mortality in developing countries. A comprehensive understanding of the molecular mechanisms of tumor progression in laryngeal cancer is needed for new treatment strategies. MicroRNA-29a has been emerged as a critical miRNA in various cancers, and shown to regulate multiple oncogenic processes. In this study, we investigated the tumor suppressive role of miRNA-29a in laryngeal squamous cell carcinoma. We performed cell-based functional analysis after overexpression of miR-29a in AMC-HN-8 and HEP2 cells in vitro. It turned out that ectopic expression of miR-29a significantly inhibited cell proliferation, invasion, and migration in two LSCC cell lines (AMC-HN-8 and Hep2) in vitro. Further downstream target analysis by western blotting and luciferease reporter assay showed that overexpression of miR-29a significantly downregulated expression of STAT3, and STAT3 is a putative direct target of miR-29a in LSCC. In addition, the tumor suppressive function of miR-29a can be abrogated by forced expression of STAT3. Taken together, our data suggest that miR-29a functions as a tumor suppressor through targeting STAT3 in laryngeal squamous cell carcinoma.

Schwann Cell Stimulation of Pancreatic Cancer Cells: A Proteomic Analysis

Schwann cells (SCs), the glial component of peripheral nerves, have been identified as promoters of pancreatic cancer (PC) progression, but the molecular mechanisms are unclear. In the present study, we aimed to identify proteins released by SCs that could stimulate PC growth and invasion. Proteomic analysis of human primary SC secretome was performed using liquid chromatography–tandem mass spectrometry, and a total of 13,796 unique peptides corresponding to 1,470 individual proteins were identified. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment were conducted using the Database for Annotation, Visualization, and Integrated Discovery. Metabolic and cell–cell adhesion pathways showed the highest levels of enrichment, a finding in line with the supportive role of SCs in peripheral nerves. We identified seven SC-secreted proteins that were validated by western blot. The involvement of these SC-secreted proteins was further demonstrated by using blocking antibodies. PC cell proliferation and invasion induced by SC-conditioned media were decreased using blocking antibodies against the matrix metalloproteinase-2, cathepsin D, plasminogen activator inhibitor-1, and galectin-1. Blocking antibodies against the proteoglycan biglycan, galectin-3 binding protein, and tissue inhibitor of metalloproteinases-2 decreased only the proliferation but not the invasion of PC cells. Together, this study delineates the secretome of human SCs and identifies proteins that can stimulate PC cell growth and invasion and therefore constitute potential therapeutic targets.

Prognostic value of microRNAs in pancreatic cancer: a meta-analysis

BACKGROUND

The prognostic impact of microRNA (miRNA) expression levels in pancreatic cancer (PC) has been estimated for years, but the outcomes are controversial and heterogeneous. Therefore, we comprehensively reviewed the evidence collected on miRNA expression in PC to determine this effect.

RESULTS

PC patients with high miR-21 (HR=2.61, 95%CI=1.68-4.04), miR-451a (HR=2.23, 95%CI=1.23-4.04) or miR-1290 (HR=1.43, 95%CI=1.04-1.95) levels in blood had significantly poorer OS (P<0.05). Furthermore, PC patients with high miR-10b (HR=1.73, 95%CI=1.09-2.76), miR-17-5p (HR=1.91, 95%CI=1.30-2.80), miR-21 (HR=1.90, 95%CI=1.61-2.25), miR-23a (HR=2.18, 95%CI=1.52-3.13), miR-155 (HR=2.22, 95%CI=1.27-3.88), miR-203 (HR=1.65, 95%CI=1.14-2.40), miR-221 (HR=1.72, 95%CI=1.08-2.74), miR-222 levels (HR=1.72, 95%CI=1.02-2.91) or low miR-29c (HR=1.39, 95%CI=1.08-1.79), miR-126 (HR=1.55, 95%CI=1.23-1.95), miR-218 (HR=2.62, 95%CI=1.41-4.88) levels in tissues had significantly shorter OS (P<0.05).

CONCLUSIONS

In summary, blood miR-21, miR-451a, miR-1290 and tissue miR-10b, miR-17-5p, miR-21, miR-23a, miR-29c, miR-126, miR-155, miR-203, miR-218, miR-221, miR-222 had significant prognostic value.

METHODS

We searched PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews to recognize eligible studies, and 57 studies comprising 5445 PC patients and 15 miRNAs were included to evaluate the associations between miRNA expression levels and overall survival (OS) up to June 1, 2019. Summary hazard ratios (HR) with 95% confidence intervals (CI) were calculated to assess the effect.

MiR-29c-3p, a target miRNA of LINC01296, accelerates tumor malignancy: therapeutic potential of a LINC01296/miR-29c-3p axis in ovarian cancer

As one of the main gynecological cancers, ovarian cancer (OC) has an unfavourable outcomes owing to its high recurrence and metastasis rate. Our previous studies have revealed that LINC01296 functions as an oncogene in OC, but the underlying mechanism has not been explored. The aim of this paper was to further investigate that how LINC01296 plays a role in OC. Through online software prediction, miR-29c-3p has been discriminated as the target miRNA of LINC01296 for further research, and subsequent luciferase assay confirmed bioinformatics prediction. Then the data obtained from the two databases (GSE119055 and GSE83693) were analyzed by GEO2R for differential gene analysis. The results indicated that the miR-29c-3p was lowly expressed in OC tissues than that in normal ovarian tissues, and its expression in recurrent OC tissues was lower than that in primary OC tissues. Simultaneously, Kaplan-Meier survival analysis illustrated that the lower expression of miR-29c-3p was interrelated to unfavourable outcomes of OC. Further, the qRT-PCR data revealed that the miR-29c-3p expression in OC cell lines (SKOV-3 and OVCAR-3) was markedly declined than that in normal control cells (IOSE80). Subsequently, the functional experiments, such as CCK8, colony formation and Transwell assays, prompted that inhibition of miR-29c-3p can obviously increase the proliferation, invasion and migration of OVCAR3 and SKOV3 cells compared with control group, while downregulation of LINC01296 showed an opposite result. It is worth noting that downregulation of LINC01296 can reverse the effect of miR-29c-3p suppression on OC cells. Finally, we detected the changes of EMT-related proteins by western blot experiment, and reached a similar conclusion that knockdown of LINC01296 reversed the EMT caused by miR-29c-3p inhibition. In sum up, the cancer-promoting function of LINC01296 was achieved by regulating the expression of miR-29c-3p, and LINC01296/miR-29c-3p axis mediates the mechanical regulation of EMT in OC cells, hoping to provide the novel biomarkers and possibilities for OC therapy.

Pancreatic Ductal Adenocarcinoma: MicroRNAs Affecting Tumor Growth and Metastasis in Preclinical In Vivo Models

Patients with pancreatic ductal adenocarcinoma have a dismall prognosis because at the time of diagnosis, in the vast majority of patients the tumor has already disseminated to distant organs and the therapeutic benefit of approved agents such as gemcitabine is limited. Therefore, the identification and preclinical and clinical validation of therapeutic agents covering new targets is of paramount importance. In this review we have summarized microRNAs and corresponding targets which affect growth and metastasis of pancreatic tumors in preclinical mouse in vivo models. We identified four up-regulated and 16 down-regulated miRs in PDAC in comparison to corresponding normal tissues. Three sub-categories of miRs have emerged: miRs affecting tumor growth and miRs with an impact on both, tumor growth and metastasis or metastasis only. Finally, we discuss technical and therapeutic aspects of miR-related therapeutic agents for the treatment of pancreatic ductal adenocarcinoma.

Downregulation of miR-29c-3p is associated with a poor prognosis in patients with laryngeal squamous cell carcinoma

Background

Laryngeal squamous cell carcinoma (LSCC) is considered to be a common malignancy of the head and neck with poor prognosis for its late diagnosis, metastasis and recurrence. Growing evidence demonstrates that the dysregulation of miR-29c-3p (microRNA-29c-3p) plays an important role in various tumor processes. Our study investigates the expression of miR-29c-3p in LSCC and analyzes the correlation of its dysregulation with clinicopathologic parameters and prognosis.

Methods

The expression of hsa-miR-29c-3p in LSCC tissues and the adjacent normal laryngeal tissues was detected in 96 LSCC formalin-fixed paraffin-embedded tissues by quantitative real-time PCR (qRT-PCR). The SPSS statistical software package (17.0) was used to analyze the associations between miR-29c-3p expressions and various clinicopathological characteristics. The overall survival (OS) was analyzed by the Kaplan-Meier method and log-rank test, and we analyzed the independent factor of prognosis by Cox proportional hazard analysis.

Results

A downregulation of miR-29c-3p expression in LSCC was significantly correlated with smoking index, tumor size, tumor site, differentiation, T classification, TNM stage, and lymph node metastasis (P < 0.05), but there was no correlation with age and alcohol consumption (P > 0.05). In the multivariate survival analysis, low miR-29c-3p expression was associated with shorter overall survival (P < 0.05). Furthermore, miR-29c expression was an independent prognostic factor for laryngeal cancer patients.

Conclusions

MiR-29c-3p has different expression levels at different stages of tumor progression, suggesting that miR-29c-3p may be a promising biomarker for evaluating the progression of LSCC and the prognosis of patients with LSCC. MiR-29c-3p can also be a novel molecular target for anti-laryngeal cancer therapy.

Insulin promotes invasion and migration of KRASG12D mutant HPNE cells by upregulating MMP-2 gelatinolytic activity via ERK- and PI3K-dependent signalling

Objectives

Hyperinsulinemia is a risk factor for pancreatic cancer, but the function of insulin in carcinogenesis is unclear, so this study aimed to elucidate the carcinogenic effects of insulin and the synergistic effect with the KRAS mutation in the early stage of pancreatic cancer.

Materials and methods

A pair of immortalized human pancreatic duct‐derived cells, hTERT‐HPNE E6/E7/st (HPNE) and its oncogenic KRAS^G12D variant, hTERT‐HPNE E6/E7/KRAS^G12D/st (HPNE‐mut‐KRAS), were used to investigate the effect of insulin. Cell proliferation, migration and invasion were assessed using Cell Counting Kit‐8 and transwell assays, respectively. The expression of E‐cadherin, N‐cadherin, vimentin and matrix metalloproteinases (MMP‐2, MMP‐7 and MMP‐9) was evaluated by Western blotting and/or qRT‐PCR. The gelatinase activity of MMP‐2 and MMP‐9 in conditioned media was detected using gelatin zymography. The phosphorylation status of AKT, GSK3β, p38, JNK and ERK1/2 MAPK was determined by Western blotting.

Results

The migration and invasion ability of HPNE cells was increased after the introduction of the mutated KRAS gene, together with an increased expression of MMP‐2. These effects were further enhanced by the simultaneous administration of insulin. The use of MMP‐2 siRNA confirmed that MMP‐2 was involved in the regulation of cell invasion. Furthermore, there was a concentration‐ and time‐dependent increase in gelatinase activity after insulin treatment, which could be reversed by an insulin receptor tyrosine kinase inhibitor (HNMPA‐(AM)₃). In addition, insulin markedly enhanced the phosphorylation of PI3K/AKT, p38, JNK and ERK1/2 MAPK pathways, with wortmannin or LY294002 (a PI3K‐specific inhibitor) and PD98059 (a MEK1‐specific inhibitor) significantly inhibiting the insulin‐induced increase in MMP‐2 gelatinolytic activity.

Conclusions

Taken together, these results suggest that insulin induced migration and invasion in HPNE and HPNE‐mut‐KRAS through PI3K/AKT and ERK1/2 activation, with MMP‐2 gelatinolytic activity playing a vital role in this process. These findings may provide a new therapeutic target for preventing carcinogenesis and the evolution of pancreatic cancer with a background of hyperinsulinemia.

A Systematic Review of miR-29 in Cancer

MicroRNAs (miRNA) are small non-coding RNAs (∼22 nt in length) that are known as potent master regulators of eukaryotic gene expression. miRNAs have been shown to play a critical role in cancer pathogenesis, and the misregulation of miRNAs is a well-known feature of cancer. In recent years, miR-29 has emerged as a critical miRNA in various cancers, and it has been shown to regulate multiple oncogenic processes, including epigenetics, proteostasis, metabolism, proliferation, apoptosis, metastasis, fibrosis, angiogenesis, and immunomodulation. Although miR-29 has been thoroughly documented as a tumor suppressor in the majority of studies, some controversy remains with conflicting reports of miR-29 as an oncogene. In this review, we provide a systematic overview of miR-29's functional role in various mechanisms of cancer and introspection on the contradictory roles of miR-29.

MiR‐29a, targeting caveolin 2 expression, is responsible for limitation of pancreatic cancer metastasis in patients with normal level of serum CA125

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive gastrointestinal tumors, with an overall 5‐year survival rate less than 8%. The dismal prognosis is mainly due to aggressive potential for metastasis. Hence, there is an urgent need for a better understanding of the molecular mechanisms underlying pancreatic cancer invasion and metastasis to improve the unfavorable overall survival (OS) of PDAC patients. In this study, we identified microRNA‐29a (miR‐29a) as an important tumor suppressor, which was downregulated in PDAC tissues. Moreover, miR‐29a counteracted MUC16‐mediated migration and invasion. In the pancreatic cancer cells, MUC16 upregulated c‐Myc expression, which enhanced c‐Myc binding to E‐box in the miR‐29a promoter and inhibited miR‐29a transcription. Thus, miR‐29a was negatively correlated with both MUC16 expression and serum CA125 levels. Furthermore, caveolin 2 (CAV2) was demonstrated to be the target of miR‐29a by bioinformatics and luciferase reporter assays, and high CAV2 expression was responsible for a poor prognosis, especially in the subgroup with normal CA125 levels. Thus, the present study explains why high levels of serum CA125 are correlated with PDAC metastasis, highlighting the predictive value of this marker in PDAC patients.

Long Noncoding RNA TUG1/miR-29c Axis Affects Cell Proliferation, Invasion, and Migration in Human Pancreatic Cancer

Given the low resection rate and chemoresistance of patients with pancreatic cancer (PC), their survival rates are typically poor. Long noncoding RNAs (lncRNAs) have recently been shown to play an important role in tumourigenesis and human cancer progression, including in PC. In this study, we aimed to investigate the role of taurine-upregulated gene 1 (TUG1) in PC. A quantitative polymerase chain reaction was used to analyse TUG1 expression in PC tissues and peritumoural normal tissues. TUG1 was overexpressed in PC tissues compared with that in peritumoural normal tissues, and the high expression of TUG1 was associated with the poor prognosis of patients with PC. Furthermore, TUG1 knockdown significantly inhibited the proliferation and invasion of PC cells both in vitro and in vivo, while overexpression TUG1 promoted tumour cell proliferation, migration, and invasion. TUG1 directly targeted miR-29c, a tumour suppressor in several cancers. TUG1 knockdown significantly increased the expression of miR-29c and subsequently induced the downregulation of integrin subunit beta 1 (ITGB1), matrix metalloproteinase-2 (MMP2), and matrix metalloproteinase-9 (MMP9). The downregulation of miR-29c abolished the TUG1 knockdown-mediated inhibition of tumour growth in vitro and in vivo, whereas the upregulation of miR-29c enhanced the effects of TUG1 knockdown on PC cells. In conclusion, we demonstrate for the first time the oncogenic role of TUG1 in PC. The downregulation of TUG1 significantly inhibited the growth and migratory ability of PC cells in vitro and in vivo by targeting miR-29c. Our study provides a novel potential diagnostic biomarker and therapeutic target for PC.

miR-29b negatively regulates MMP2 to impact gastric cancer development by suppress gastric cancer cell migration and tumor growth

MicroRNAs (miRNAs) are important regulators and associated with the development of many different types of cancer, including gastric cancer. However, their pathophysiologic role and their relevance to tumorigenesis, invasion and metastasis are still unknown. In our current study, we performed microRNA array and found that 28 of miRNAs were differentially expressed in INF type of gastric cancer. Among 28 miRNAs, miR-29b was one of the most significantly down-regulated miRNA. Further bioinformatics analysis showed that MMP2 was a potential target of miR-29b. Interestingly, luciferase analysis showed that miR-29b negatively regulates MMP2 by binding with the miRNA response element (MRE) on the 3'UTR of MMP2. In addition, overexpression of miR-29b significantly decreased the mRNA and protein level of MMP2 and the activity of MMP2 to suppress gastric cancer cell migration. Moreover, lentivirus mediated overexpression of miR-29b dramatically suppressed the ability of BGC823 cells to form colonies in vitro and their ability to develop tumor in vivo in nude mice. Finally, our qPCR and western blot analysis showed that miR-29b was significantly reduced in clinical gastric cancer tissue, whereas MMP2 protein was significantly up-regulated, suggesting that this aberrant down-regulation of miR-29b might be associated with the abnormal regulation of MMP2 and the development of gastric cancer. Significant apparent was also found between miR-29b expression and TNM staging, lymph node status, tumor differentiation and Ming classification. Together, our data suggest an important regulatory role of miR-29b in the development of gastric cancer. Thus, miR-29b and MMP2 might be important diagnostic or therapeutic targets for human tumor diseases.

A miRNA Combination as Promising Biomarker for Hepatocellular Carcinoma Diagnosis: A Study Based on Bioinformatics Analysis

Background: miRNAs dysregulate in hepatocellular carcinoma (HCC), showing promise for diagnostic biomarkers which may be found through exploration of differentially expressed miRNAs when comparing HCC and normal liver tissues. Materials and Methods: In the present research, candidate miRNAs were selected and verified using screening dataset GSE12717 and training dataset GSE10694, respectively. A miRNA combination was constructed using stepwise logistic regression analysis and validated using two datasets GSE74618 and TCGA. Target genes of miRNAs in the combination were obtained using a miRNA target gene prediction database. Functional analysis was conducted using an online tool DAVID. We also analyzed the mRNA-Seq data of project LIHC from TCGA to identify the hub target genes of the miRNAs. Results: A miRNA combination, which is composed of hsa-miR-221 and hsa-miR-29c was defined in this study. The miRNA combination is more effective in discriminating HCC patients from normal individuals than individual miRNAs. Additionally, the combined miRNAs showed a lower misdiagnosis rate than AFP in HCC diagnosis. In terms of the functional analysis, a total of 27 target genes of hsa-miR-221 and 96 target genes of hsa-miR-29c were obtained. Among which, INSIG1 was the common target of the two miRNAs. It was also found that both previously mentioned miRNAs played important roles in the regulation of transcription, cell proliferation, and involvement in cancer-related pathways. Lastly, 2 hub target genes of hsa-miR-221 and 16 hub target genes of hsa-miR-29c were obtained. Conclusion: We established a miRNA combination as a promising tool for HCC diagnosis, and the target genes we predicted provide possible points of penetration for researching these two miRNAs in HCC.

Circular RNA IARS (circ-IARS) secreted by pancreatic cancer cells and located within exosomes regulates endothelial monolayer permeability to promote tumor metastasis

BACKGROUND

Recent studies show that exosomes are involved in intercellular communication and that abundant circular RNAs (circRNAs) are present within exosomes. However, whether these exosomal circRNAs contribute to tumor invasion and metastasis remains unclear, as do their associated mechanisms.

METHODS

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to measure the expression levels of circ-IARS in 85 pancreatic ductal adenocarcinoma (PDAC) tissues, plasma exosomes, and Hs 766 T, Hs 766 T-L2 and human microvascular vein endothelial (HUVECs) cells. RhoA, ZO-1 and RhoA-GTP levels were detected by qRT-PCR and western blotting (WB); RhoA activity analysis was also performed. Transwell assays were performed to examine changes in endothelial monolayer permeability, and immunofluorescence and WB were employed to evaluate F-actin expression and focal adhesion. Finally, an animal experiment was performed to detect the contribution of circ-IARS to cancer metastasis.

RESULTS

circ-IARS expression was up-regulated in pancreatic cancer tissues and in plasma exosomes of patients with metastatic disease. Circ-IARS was found to enter HUVECs through exosomes and promote tumor invasion and metastasis. Circ-IARS expression was positively correlated with liver metastasis, vascular invasion, and tumor-node-metastasis (TNM) stage and negatively correlated with postoperative survival time. Overexpression of circ-IARS significantly down-regulated miR-122 and ZO-1 levels, up-regulated RhoA and RhoA-GTP levels, increased F-actin expression and focal adhesion, enhanced endothelial monolayer permeability, and promoted tumor invasion and metastasis.

CONCLUSIONS

circ-IRAS accesses HUVECs via exosomes derived from pancreatic cancer cells followed by increased endothelial monolayer permeability. Furthermore, this process promotes tumor invasion and metastasis. The results of this study suggest that the presence of circRNAs in exosomes may be important indicator for early diagnosis and prognostic prediction in PDAC.

Tumor-derived exosomal lnc-Sox2ot promotes EMT and stemness by acting as a ceRNA in pancreatic ductal adenocarcinoma

Long noncoding RNAs (lncRNAs) or exosomes have recently been shown to play vital regulatory or communication roles in cancer biology. However, the roles and mechanisms of exosomal lncRNAs in tumor invasion or metastasis of pancreatic ductal adenocarcinoma (PDAC) remain unknown. In this study, we aimed to investigate the detailed roles and mechanisms of tumor-generated exosomes in progression and metastasis of PDAC in vitro and in vivo. We identified a lncRNA-Sox2ot from exosomes of highly invasive PDAC cells, and analyzed the expression of Sox2ot in the plasma samples and found that the plasma exosomal Sox2ot expression was high and correlated with TNM stage and overall survival rate of PDAC patients. Further research showed that Sox2ot promotes epithelial-mesenchymal transition (EMT) and stem cell like properties by regulating Sox2 expression. Sox2ot competitively binds to the miR-200 family to regulate the expression of Sox2, thus promoting invasion and metastasis of PDAC. We also confirmed the transmission of the exosomes from producer cells to recipient PDAC cells, exosomal Sox2ot can promote tumor invasion and metastasis in vitro and in vivo. We further confirmed tumor generated exosomes could excrete to tumor cell or blood circulation in vivo condition. Finally, we observed a decreased exosomal Sox2ot expression in postoperative blood samples of PDAC patients. The exosomal lncRNA Sox2ot plays important roles in tumor progression and may be a useful maker for pancreatic cancer prognosis.

The role of miRNAs in the diagnosis, chemoresistance, and prognosis of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) remains a very challenging malignancy with late presentation, metastatic potential, chemoresistance, and poor prognosis. Therefore, there is an urgent need for novel diagnostic and prognostic biomarkers. miRNAs are small noncoding RNAs that regulate the expression of multitude number of genes. Aberrant expression of miRNAs has been linked to the development of various malignancies, including PDAC. A series of miRNAs have been defined as holding promise for early diagnostics, as indicators of therapy resistance, and even as markers for prognosis in PDAC patients. In this review, we summarize the current knowledge on the role of miRNAs in diagnosis, chemoresistance, and prognosis in PDAC patients.

Challenges in detecting pre-malignant pancreatic lesions during acute pancreatitis using a serum microRNA assay: a study based on KrasG12D transgenic mice

Caerulein-induced acute pancreatitis accelerates the progression of pancreatic intraepithelial neoplasia (PanIN) lesions in a pancreas-specific KrasG12D mouse model. The purpose of this study was to explore whether serum microRNAs (miRNAs) can serve as sensitive biomarkers to detect occult PanIN in the setting of acute pancreatitis. Serum miRNA profiles were quantified by an array-based method and normalized by both Variance Stabilization Normalization (VSN) and invariant methods. Individual miRNAs were validated by TaqMan real-time PCR with synthetic spike-in C. elegans miRNAs as external controls. Serum miRNA profiles distinguished KrasG12D mice with pancreatitis from wild-type mice without pancreatitis, but failed to differentiate KrasG12D mice with pancreatitis from wild-type mice with pancreatitis. Most individual miRNAs that increased in KrasG12D mice with pancreatitis were not significantly different between KrasG12D mice without pancreatitis and wild-type mice without pancreatitis. Mechanistically, Gene Set Enrichment Analysis (GSEA) of the mRNA array data and immunohistochemical assays showed that caerulein-induced acute pancreatitis involved acinar cell loss and immune cell infiltration, which might contribute to serum miRNA profile changes. This study highlighted the challenges in using sensitive serum miRNA biomarker screening for the early detection of pancreatic malignancies during acute pancreatitis.

mir-329 restricts tumor growth by targeting grb2 in pancreatic cancer

Pancreatic cancer is one of the most lethal malignancies worldwide. To illustrate the pathogenic mechanism(s), we looked into the expression and function of miR-329 associated with pancreatic cancer development. It was found that miR-329 expression was downregulated in the pancreatic cancer patients who demonstrated significantly shorter overall survival than the patients having upregulated expression. Also, more advanced pT stage cases were observed in the low miR-329 expression group of patients. Interestingly, our studies uncovered that miR-329 overexpression inhibited proliferation and induced apoptosis of pancreatic cancer cells, in contrast the miR-329 inhibitor reversed this phenomenon dramatically. Additionally, overexpression of miR-329 significantly limited tumor growth in the xenograft model. In the mechanistic study, we identified GRB2 as a direct target of miR-329 in pancreatic cancer cells, and expression of GRB2 was inversely correlated with miR-329 expression in pancreatic cancer patients. Furthermore, GRB2 overexpression in cell line and xenograft model dramatically diminished miR-329 mediated anti-proliferation and apoptosis induction, indicating that GRB2/pERK pathway was mainly downregulated by miR-329 expression. In general, our study has shed light on miR-329 regulated mechanism and, miR-329/GRB2/pERK is potential to be targeted for pancreatic cancer management.

Orthotopic Xenograft Mouse Model of Cervical Cancer for Studying the Role of MicroRNA-21 in Promoting Lymph Node Metastasis

Cervical cancer is the most frequent cause of gynecologic cancer-associated death worldwide. Animal models that demonstrate metastatic patterns consistent with the clinical course of cervical cancer are urgently needed to conduct studies focused on understanding the mechanisms of the disease and identifying optimal treatments. To address this, we established an orthotopic xenograft model of cervical cancer in female NOD-SCID mice using SiHa and ME180 cell lines stably expressing green fluorescent protein to evaluate the role of microRNA-21 (miR-21) in spontaneous lymph node metastasis in vivo. In this case, SiHa and ME180 cells were transduced by lentivirus to stably express green fluorescent protein and miR-21. Overexpression of miR-21 promoted proliferation, migration, and invasion of SiHa and ME180 cells in vitro. Finally, an orthotopic xenograft model of human cervical cancer was successfully established in NOD-SCID mice. Using this model, we confirmed that overexpression of miR-21 resulted in an increase in the size of primary tumors and in the frequency of spontaneous lymph node metastasis at the time of excision. Therefore, the use of the orthotopic xenograft model should allow for the investigation of novel factors that affect metastasis of cervical cancer and presents an opportunity to evaluate potential therapeutic agents that may inhibit the spread of the disease.

HDAC2 was involved in placental P-glycoprotein regulation both in vitro and vivo

INTRODUCTION

Placental P-glycoprotein (P-gp) plays a significant role in regulating drugs' transplacental transfer rates. Investigations on placental P-gp regulation could provide more therapeutic targets for individualized and safe pharmacotherapy during pregnancy. Currently, the epigenetic regulation of placental P-gp is rare. Our previous study has demonstrated that HDACs inhibition could up-regulate placental P-gp and HDAC1/2/3 might be involved in this process. The present study was carried out to further explore whether HDAC1/2/3 were indeed involved in the regulation of placental P-gp or not and screen out the subtype engaged in this process.

METHODS

BeWo and JAR cells were transfected with HDAC1/2/3 specific siRNA. After 48 h of transfection, cells were harvested for real-time quantitative PCR (qRT-PCR), Western blot, immunofluorescence and fluorescent dye efflux assay to evaluate P-gp expression, localization, and efflux activity, respectively. Hdac2 siRNA was intraperitoneally injected to pregnant mice every 48 h from E7.5 to E15.5 and digoxin was administered by gavages 1 h prior to euthanasia at E16.5. Placental Hdac1/2/3 and P-gp expression were determined by qRT-PCR and Western blot. Maternal plasma and fetal-unit digoxin concentrations were detected by enzyme-multiplied immunoassay.

RESULTS

In vitro, HDAC2 inhibition could significantly elevate P-gp expression and reduce intracellular accumulation of P-gp substrates (DiOC₂ (3) and Rh 123) both in BeWo and JAR, while knockdown of HDAC1/3 had no influence on P-gp expression and its efflux activity. Additionally, in vivo, Hdac2 silencing in pregnant mice also elevated placental P-gp expression and decreased digoxin transplacental transfer rate.

CONCLUSION

HDAC2 inhibition could result in induction of placental P-gp expression and functionality both in vitro and in vivo.

A blockade of PD-L1 produced antitumor and antimetastatic effects in an orthotopic mouse pancreatic cancer model via the PI3K/Akt/mTOR signaling pathway

BACKGROUND

Pancreatic cancer is one of the most aggressive and intractable malignant tumors, and most deaths from pancreatic cancer are related to metastases. It has been demonstrated in vitro that overexpression of programmed death-ligand 1 (PD-L1) correlates with a lack of phosphatase and tensin homologue (PTEN) expression in pancreatic cancer tissue. This loss of PTEN expression may aberrantly activate the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway, and thereby promote tumor cell survival, proliferation, and disease progression. In this study, we investigated the potential therapeutic effect of blockading PD-L1 expression on the progression of pancreatic cancer and its spontaneous liver metastases in vivo by inhibiting the PI3K/Akt/mTOR signaling pathway.

METHODS

We investigated the effect of blockading PD-L1 in an orthotopic pancreatic cancer mouse model. The pancreatic tumor weights and inhibition ratios were determined after treatment with antimouse PD-L1 antibody for 5 weeks. We used immunohistochemistry methods to investigate PD-L1 expression in pancreatic cancer tissue and spontaneous liver metastasis tissue. The levels of mRNA and protein expression for various components involved in the PI3K/Akt/mTOR signaling pathway as well as for matrix metalloproteinases-2 and -9 (MMP2 and MMP9) were measured by reverse transcription polymerase chain reaction (RT-PCR) and Western blot methods, respectively.

RESULTS

Blockading PD-L1 significantly inhibited tumor growth and decreased the levels of PD-L1 expression in tumor tissue. Furthermore, the levels of PTEN mRNA and protein expression were elevated, while the levels of phospho-Akt (p-Akt) and phospho-mTOR (p-mTOR) protein were decreased in pancreatic cancer and liver metastasis tissues after establishing a PD-L1 blockade. In addition, a PD-L1 blockade decreased the levels of MMP2 and MMP9 mRNA and protein expression in tumor tissues.

CONCLUSION

Our results suggest that a blockade of PD-L1 may inhibit the growth and metastasis of pancreatic cancer by modulating the PI3K/Akt/mTOR pathway.

Molecular Drivers of Pancreatic Cancer Pathogenesis: Looking Inward to Move Forward

Pancreatic cancer (PC) continues to rank among the most lethal cancers. The consistent increase in incidence and mortality has made it the seventh leading cause of cancer-associated deaths globally and the third in the United States. The biggest challenge in combating PC is our insufficient understanding of the molecular mechanism(s) underlying its complex biology. Studies during the last several years have helped identify several putative factors and events, both genetic and epigenetic, as well as some deregulated signaling pathways, with implications in PC onset and progression. In this review article, we make an effort to summarize our current understanding of molecular and cellular events involved in the pathogenesis of pancreatic malignancy. Specifically, we provide up-to-date information on the genetic and epigenetic changes that occur during the initiation and progression of PC and their functional involvement in the pathogenic processes. We also discuss the impact of the tumor microenvironment on the molecular landscape of PC and its role in aggressive disease progression. It is envisioned that a better understanding of these molecular factors and the mechanisms of their actions can help unravel novel diagnostic and prognostic biomarkers and can also be exploited for future targeted therapies.

Meta-analysis of the differentially expressed microRNA profiles in nasopharyngeal carcinoma

MicroRNAs(miRNAs), as non-coding molecules, were proved to be correlated with gene expression in naspharyngeal carcinoma (NPC) development. In this research, a comprehensive meta-analysis of eight independent miRNA expression studies in NPC was preformed by using robust rank aggregation method (RRA), which contained a total of 775 tumor and 227 non-cancerous samples. There were 7 significant dysregulated miRNAs identified including three increased (miR-483–5p, miR-29c-3p and miR-205–5p) and four decreased (miR-29b-3p, let-7d-5p, miR-100– 5p and let-7g-5p) miRNAs. Subsequently, the miRNA target prediction and pathway enrichment analysis were carried out to find out the biological and functional relevant genes involved in the meta-signature miRNA regulation. Finally, several signaling and cancer pathogenesis pathways were suggested to be more frequently associated with the progression of NPC. In this research the meta-signature miRNA identified may be used to develop a series of diagnostic and prognostic biomarkers for NPC that serve specificity for use in clinics.

Murine Experimental Model of Original Tumor Development and Peritoneal Metastasis via Orthotopic Inoculation with Ovarian Carcinoma Cells

Epithelial ovarian carcinoma (EOC) is associated with a poor prognosis because it shows peritoneal dissemination. To improve the prognosis, it is important to control peritoneal dissemination. However, it is still unclear how tumor cells detach from primary lesions and attach to the mesothelium. The establishment of an appropriate animal model is needed to gain an understanding of the mechanism of peritoneal dissemination in vivo. In the current study, we introduce the process from the local injection of EOC cells into the murine ovarian surface to the development of metastasis, including the peritoneum and distant organs. Female nude mice (BALB/c nu/nu) at 8 weeks of age were used. Under a microscopic field of view, EOC cells (1 x 10⁵ cells/µl of medium-extracellular matrix (ECM)-based hydrogel/unilateral ovary/mouse) were injected into murine ovaries through a retroperitoneal approach from the dorsal flank. This proposed method is a less invasive procedure for the mouse and minimizes damage to the ovary. Here, we describe the methodological steps in the development of the original and metastatic tumor formation of EOC.

Novel role of miR-29a in pancreatic cancer autophagy and its therapeutic potential

Pancreatic Ductal Adenocarcinoma (PDAC) is a highly lethal malignancy that responds poorly to current therapeutic modalities. In an effort to develop novel therapeutic strategies, we found downregulation of miR-29 in pancreatic cancer cells, and overexpression of miR-29a sensitized chemotherapeutic resistant pancreatic cancer cells to gemcitabine, reduced cancer cell viability, and increased cytotoxicity. Furthermore, miR-29a blocked autophagy flux, as evidenced by an accumulation of autophagosomes and autophagy markers, LC3B and p62, and a decrease in autophagosome-lysosome fusion. In addition, miR-29a decreased the expression of autophagy proteins, TFEB and ATG9A, which are critical for lysosomal function and autophagosome trafficking respectively. Knockdown of TFEB or ATG9A inhibited autophagy similar to miR-29a overexpression. Finally, miR-29a reduced cancer cell migration, invasion, and anchorage independent growth. Collectively, our findings indicate that miR-29a functions as a potent autophagy inhibitor, sensitizes cancer cells to gemcitabine, and decreases their invasive potential. Our data provides evidence for the use of miR-29a as a novel therapeutic agent to target PDAC.

MicroRNA-Based Therapy in Animal Models of Selected Gastrointestinal Cancers

Gastrointestinal cancer accounts for the 20 most frequent cancer diseases worldwide and there is a constant urge to bring new therapeutics with new mechanism of action into the clinical practice. Quantity of in vitro and in vivo evidences indicate, that exogenous change in pathologically imbalanced microRNAs (miRNAs) is capable of transforming the cancer cell phenotype. This review analyzed preclinical miRNA-based therapy attempts in animal models of gastric, pancreatic, gallbladder, and colorectal cancer. From more than 400 original articles, 26 was found to assess the effect of miRNA mimics, precursors, expression vectors, or inhibitors administered locally or systemically being an approach with relatively high translational potential. We have focused on mapping available information on animal model used (animal strain, cell line, xenograft method), pharmacological aspects (oligonucleotide chemistry, delivery system, posology, route of administration) and toxicology assessments. We also summarize findings in the field pharmacokinetics and toxicity of miRNA-based therapy.

MicroRNA in pancreatic adenocarcinoma: predictive/prognostic biomarkers or therapeutic targets?

Pancreatic ductal adenocarcinoma (PDAC) is a tumor with a poor prognosis, short overall survival and few chemotherapeutic choices. MicroRNAs (miRNAs) are non-coding, single-stranded RNAs of around 22 nucleotides involved in the pathogenic mechanisms of carcinogenesis and metastasis. They have been studied in many tumors in order to identify potential diagnostic, prognostic or therapeutic targets. In the current literature, many studies have analyzed the role of miRNAs in PDAC. In fact, the absence of appropriate biomarkers, the difficultly of early detection of this tumor, and the lack of effective chemotherapy in patients with unresectable disease have focused attention on miRNAs as new, interesting advance in this malignancy.

In this review we analyzed the role of miRNAs in PDAC in order to understand the mechanisms of action and the difference between the onco-miRNA and the tumor suppressor miRNA. We also reviewed all the data related to the use of these molecules as predictive as well as prognostic biomarkers in the course of the disease.

Finally, the possible therapeutic use of miRNAs or anti-miRNAs in PDAC is also discussed.

In conclusion, although there is still no clinical application for these molecules in PDAC, it is our opinion that the preclinical evidence of the role of specific miRNAs in carcinogenesis, the possibility of using miRNAs as diagnostic or prognostic biomarkers, and their potential therapeutic role, warrant future studies in PDAC.

Expression profiles of miR-29c, miR-200b and miR-375 in tumour and tumour-adjacent tissues of head and neck cancers

Altered expression of microRNAs (miRNAs) has been shown in many types of malignancies including the head and neck squamous cell carcinoma (HNSCC). Although there are many new and innovative approaches in the treatment of HNSCC, a clear marker of this disease is still missing. Three candidate miRNAs (miR-29c-3p, miR-200b-5p and miR-375-3p) were studied in connection with HNSCC using quantitative real-time PCR expression levels in 42 tissue samples of HNSCC patients and histologically normal tumour-adjacent tissue samples of these patients. Primary HNSCC carcinoma tissues can be distinguished from histologically normal-matched noncancerous tumour-adjacent tissues based on hsa-miR-375-3p expression (sensitivity 87.5 %, specificity 65 %). Additionally, a significant decrease of hsa-miR-200b-5p expression was revealed in tumour-adjacent tissue samples of patients with node positivity. Lower expression of hsa-miR-200b-5p and hsa-miR-29c-3p in HNSCC tumour tissue was associated with higher tumour grade. Consequently, survival analysis was performed. Lower expression of hsa-miR-29c-3p in tumour-adjacent tissue was associated with worse overall and disease-specific survivals. Lower expression of miR-29c-3p in tumourous tissue was associated with worse relapse-free survival. hsa-miR-375-3p seems to be a relatively promising diagnostic marker in HNSCC but is not suitable for prognosis of patients. Furthermore, this study highlighted the importance of histologically normal tumour-adjacent tissue in HNSCC progress (significant decrease of hsa-miR-200b-5p expression in tumour-adjacent tissue of patients with node positivity and low expression of hsa-miR-29c-3p in HNSCC tumour-adjacent tissue associated with worse prognosis).

IGF1 3'UTR functions as a ceRNA in promoting angiogenesis by sponging miR-29 family in osteosarcoma

Osteosarcoma is one of the most common malignant bone tumors in human worldwide. Angiogenesis is a pivotal process during osteosarcoma development. Insulin-like growth factor 1 (IGF1) has been reported to promote angiogenesis. However, the role of 3' untranslational region (3'UTR) of IGF1 mRNA in angiogenic activity in osteosarcomas is still unknown. In the present study, we performed gain-of-function assays to investigate the role of IGF1-3'UTR in angiogenesis. For the first time, we demonstrated that IGF1 3'UTR increased VEGF expression and promotes angiogenesis in osteosarcoma cells. In addition, RNA-immunoprecipitation and luciferase reporter assays showed that IGF1 3'UTR was a direct target of miR-29s. Our data also demonstrated that there existed a competition of miR-29s between IGF1-3'UTR and VEGF mRNA, and IGF1-3'UTR promoted angiogenesis at least in part via sponging miR-29s. Taken together, our study suggests that IGF1-3'UTR functions as a ceRNA in promoting angiogenesis by sponging miR-29s in osteosarcoma.

MiR-29c inhibits cell growth, invasion, and migration of pancreatic cancer by targeting ITGB1

MiR-29c is frequently dysregulated in many cancers; however, the roles of miR-29c in pancreatic cancer (PC) and underlying mechanisms remain poorly understood. In this study, we investigated the role of miR-29c in PC. Using quantitative real-time polymerase chain reaction, we demonstrated that miR-29c was frequently downregulated in clinical PC tissues and cell lines. Overexpression of miR-29c significantly inhibited the proliferation, migration, and invasion of PC cells in vitro, which demonstrated that miR-29c acts as a tumor suppressor in PC cells. Further analysis revealed that ITGB1 is one of the functional target genes of miR-29c, and knockdown of ITGB1 inhibited the proliferation, migration, and invasion of PC cells, which was similar to the effects of overexpression of miR-29c. Taken together, our results highlight the significance of miR-29c–ITGB1 interaction in the development and progression of PC.