MicroRNA-138-5p regulates pancreatic cancer cell growth through targeting FOXC1

Research progress on the regulatory mechanisms of FOXC1 expression in cancers and its role in drug resistance

The Forkhead box C1 (FOXC1) transcription factor is an important member of the FOX family. After initially being identified in triple-negative breast cancer (TNBC) with significant oncogenic function, FOXC1 was subsequently demonstrated to be involved in the development of more than 16 types of cancers. In recent years, increasing studies have focused on the deregulatory mechanisms of FOXC1 expression and revealed that FOXC1 expression was regulated at multiple levels including transcriptional regulation, post-transcription regulation and post-translational modification. Moreover, dysregulation of FOXC1 is also implicated in drug resistance in various types of cancer, especially in breast cancer, which further emphasizes the translational and clinical significance of FOXC1 as a therapeutic target in cancer treatment. This review summarizes recent findings on mechanisms of FOXC1 dysregulation in cancers and its role in chemoresistance, which will help to better understand the oncogenic role of FOXC1, overcome FOXC1-mediated drug resistance and develop targeted therapy for FOXC1 in cancers.

Functional and Potential Therapeutic Implication of MicroRNAs in Pancreatic Cancer

The alarmingly low five-year survival rate for pancreatic cancer presents a global health challenge, contributing to about 7% of all cancer-related deaths. Late-stage diagnosis and high heterogeneity are the biggest hurdles in treating pancreatic cancer. Thus, there is a pressing need to discover novel biomarkers that could help in early detection as well as improve therapeutic strategies. MicroRNAs (miRNAs), a class of short non-coding RNA, have emerged as promising candidates with regard to both diagnostics and therapeutics. Dysregulated miRNAs play pivotal roles in accelerating tumor growth and metastasis, orchestrating tumor microenvironment, and conferring chemoresistance in pancreatic cancer. The differential expression profiles of miRNAs in pancreatic cancer could be utilized to explore novel therapeutic strategies. In this review, we also covered studies on recent advancements in various miRNA-based therapeutics such as restoring miRNAs with a tumor-suppressive function, suppressing miRNA with an oncogenic function, and combination with chemotherapeutic drugs. Despite several challenges in terms of specificity and targeted delivery, miRNA-based therapies hold the potential to revolutionize the treatment of pancreatic cancer by simultaneously targeting multiple signaling pathways.

MicroRNAs as the Critical Regulators of Forkhead Box Protein Family in Pancreatic, Thyroid, and Liver Cancers

The metabolism of human body is mainly regulated by the pancreas, liver, and thyroid using the hormones or exocrine secretions that affect the metabolic processes from food digestion to intracellular metabolism. Therefore, metabolic organ disorders have wide clinical symptoms that severely affect the quality of patient's life. The pancreatic, liver, and thyroid cancers as the main malignancies of the metabolic system have always been considered as one of the serious health challenges worldwide. Despite the novel therapeutic modalities, there are still significant high mortality and recurrence rates, especially in liver and pancreatic cancer patients which are mainly related to the late diagnosis. Therefore, it is required to assess the molecular bases of tumor progressions to introduce novel early detection and therapeutic markers in these malignancies. Forkhead box (FOX) protein family is a group of transcription factors that have pivotal roles in regulation of cell proliferation, migration, and apoptosis. They function as oncogene or tumor suppressor during tumor progression. MicroRNAs (miRNAs) are also involved in regulation of cellular processes. Therefore, in the present review, we discussed the role of miRNAs during pancreatic, thyroid, and liver tumor progressions through FOX regulation. It has been shown that miRNAs were mainly involved in tumor progression via FOXM and FOXO targeting. This review paves the way for the introduction of miR/FOX axis as an efficient early detection marker and therapeutic target in pancreatic, thyroid, and liver tumors.

The Role of MicroRNAs in Pancreatitis Development and Progression

Pancreatitis (acute and chronic) is an inflammatory disease associated with significant morbidity, including a high rate of hospitalization and mortality. MicroRNAs (miRs) are essential post-transcriptional modulators of gene expression. They are crucial in many diseases' development and progression. Recent studies have demonstrated aberrant miRs expression patterns in pancreatic tissues obtained from patients experiencing acute and chronic pancreatitis compared to tissues from unaffected individuals. Increasing evidence showed that miRs regulate multiple aspects of pancreatic acinar biology, such as autophagy, mitophagy, and migration, impact local and systemic inflammation and, thus, are involved in the disease development and progression. Notably, multiple miRs act on pancreatic acinar cells and regulate the transduction of signals between pancreatic acinar cells, pancreatic stellate cells, and immune cells, and provide a complex interaction network between these cells. Importantly, recent studies from various animal models and patients' data combined with advanced detection techniques support their importance in diagnosing and treating pancreatitis. In this review, we plan to provide an up-to-date summary of the role of miRs in the development and progression of pancreatitis.

Identification and validation of miR-509-5p as a prognosticator for favorable survival in osteosarcoma

Osteosarcoma (OS) is the most common primary bone cancer diagnosed in children. This study aims to explore the aberrantly expressed miRNAs that are prognostically related and to provide potential biomarkers for the prognosis prediction of OS. The miRNA profiles of OS and adjacent normal controls were obtained from 2 gene expression omnibus cohorts (i.e., GSE28423 and GSE65071). GSE39058 and Therapeutically Applicable Research to Generate Effective Treatments cohorts, which respectively contained 91 and 85 OS samples with both miRNA expression and clinical characteristics, were employed to perform survival and multivariate Cox regression analyses. Lymphocyte infiltration abundance between distinct subgroups was evaluated with the CIBERSORT algorithm and a previously proposed method. Gene set enrichment analysis was used to infer the dysregulated signaling pathways within each subgroup. Of the 31 differentially expressed miRNAs, miR-509-5p (miR-509) was the most significantly prognostic miRNA in the GSE39058 cohort and its high expression was associated with the better OS prognosis (Log-rank P = .008). In the Therapeutically Applicable Research to Generate Effective Treatments validation cohort, the association of high miR-509 expression with favorable survival was also observed (Log-rank P = .014). The results remained still significant even adjusted for clinical confounding factors in multivariate Cox regression models. Further immunology analyses demonstrated that elevated infiltration of lymphocytes, decreased infiltration of immune-suppressive cells, and immune response-related pathways were significantly enriched in patients with miR-509 high expression. Our study suggests that miR-509 may serve as a potential biomarker for evaluating OS prognosis and provides clues for tailoring OS immunotherapy strategies.

miR-204-5p inhibits inflammation of synovial fibroblasts in osteoarthritis by suppressing FOXC1

BACKGROUND

The paper is aimed at uncovering the mechanism of miR-204-5p in regulating inflammatory responses of human osteoarthritic synovial fibroblasts (SFs).

METHODS

IL-1β-induced osteoarthritic SFs were established as an osteoarthritis (OA) cell model. The osteoarthritic SFs were accordingly transfected with mimics-miR-204-5p, inhibitors-miR-204-5 or FOXC1 siRNA. MTT tested the vitality of osteoarthritic SFs by analyzing the cell optical density. The expressions of miR-204-5p, FOXC1, TNF-α, IL-6, PGE2, MMP-1, MMP-13 and COX-2 in osteoarthritic SFs were measured by qRT-PCR, Western blotting and/or ELISA. The binding of miR-204-5p to FOXC1 was verified through luciferase reporter assay. The regulatory effect of miR-204-5p on FOXC1 was also tested in normal SFs.

RESULTS

miR-204-5p was under-expressed and FOXC1 was over-expressed in osteoarthritic SFs. The expressions of FOXC1, TNF-α, IL-6, PGE2, MMP-1, MMP-13 and COX-2 were up-regulated in IL-1β-treated SFs. Up-regulation of miR-204-5p or down-regulation of FOXC1 suppressed the inflammatory responses of osteoarthritic SFs. miR-204-5p negatively regulated FOXC1 by being a sponge in osteoarthritic SFs as well as in normal SFs.

CONCLUSION

miR-204-5p down-regulates FOXC1 to ameliorate inflammation of SFs in OA.

A novel epigenetic biomarker, plasma miR-138-5p gene promoter-methylated DNA, for colorectal cancer diagnosis

Aim: The miR-138-5p promoter-methylated DNA level, miR-138-5p and PDL1 expression were investigated in colorectal cancer (CRC) patients. Materials & methods: miR-138-5p promoter methylation status and miR-138-5p expression were investigated using the MethyLight and qPCR method, respectively. For measuring PDL-1, we applied the Bioassay Technology Elisa kit. Results: The percentage of methylated reference values of plasma and tissue samples from patients was higher than control groups. The area under curve presented a sensitivity of 55% and a specificity of 82.5% for plasma samples. Compared with the control groups, lower expression of miR-138-5p and higher concentration of PDL1 protein were observed in the patients group. Conclusion: CRC may be detected early by identifying miR-138-5p methylated DNA in plasma as a diagnostic biomarker.

The role of non-coding RNAs in chemotherapy for gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal, gastric, hepatic, esophageal, and pancreatic tumors, are responsible for large numbers of deaths around the world. Chemotherapy is the most common approach used to treat advanced GI cancer. However, chemoresistance has emerged as a critical challenge that prevents successful tumor elimination, leading to metastasis and recurrence. Chemoresistance mechanisms are complex, and many factors and pathways are involved. Among these factors, non-coding RNAs (ncRNAs) are critical regulators of GI tumor development and subsequently can induce resistance to chemotherapy. This occurs because ncRNAs can target multiple signaling pathways, affect downstream genes, and modulate proliferation, apoptosis, tumor cell migration, and autophagy. ncRNAs can also induce cancer stem cell features and affect the epithelial-mesenchymal transition. Thus, ncRNAs could possibly act as new targets in chemotherapy combinations to treat GI cancer and to predict treatment response.

Suppression of lncRNA NLRP3 inhibits NLRP3-triggered inflammatory responses in early acute lung injury

Acute lung injury (ALI) is a common lung pathology that is accompanied by alveolar macrophage (AM) activation and inflammatory response. This study investigated the role of the long non-coding RNA NONRATT004344 (hereafter named lncRNA NLRP3) in regulating the Nod-like receptor protein 3 (NLRP3)-triggered inflammatory response in early ALI and the underlying mechanism as well. We established LPS-induced ALI models to explore their interactive mechanisms in vitro and in vivo. Luciferase reporter assays were performed to determine that miR-138-5p could bind to lncRNA NLRP3 and NLRP3. We observed increased lncRNA NLRP3 expression, decreased miR-138-5p expression, NLRP3 inflammasome activation, and upregulated caspase-1, IL-1β, and IL-18 expression in the LPS-induced ALI model. Furthermore, lncRNA NLRP3 overexpression activated the NLRP3 inflammasome and promoted IL-1β and IL-18 secretion; the miR-138-5p mimic abolished these effects in vivo and in vitro. Consistently, miR-138-5p inhibition reversed the effects of lncRNA NLRP3 silencing on the expression of NLRP3-related molecules and inhibition of the NLRP3/caspase-1/IL-1β signalling pathway. Mechanistically, lncRNA NLRP3 sponging miR-138-5p facilitated NLRP3 activation through a competitive endogenous RNA (ceRNA) mechanism. In summary, our results suggested that lncRNA NLRP3 binding miR-138-5p promotes NLRP3-triggered inflammatory response via lncRNA NLRP3/miR-138-5p/NLRP3 ceRNA network (ceRNET) and provides insights into the treatment of early ALI.

Therapeutically Targeting Cancers That Overexpress FOXC1: A Transcriptional Driver of Cell Plasticity, Partial EMT, and Cancer Metastasis

Metastasis accounts for more than 90% of cancer related mortality, thus the most pressing need in the field of oncology today is the ability to accurately predict future onset of metastatic disease, ideally at the time of initial diagnosis. As opposed to current practice, what would be desirable is that prognostic, biomarker-based detection of metastatic propensity and heightened risk of cancer recurrence be performed long before overt metastasis has set in. Without such timely information it will be impossible to formulate a rational therapeutic treatment plan to favorably alter the trajectory of disease progression. In order to help inform rational selection of targeted therapeutics, any recurrence/metastasis risk prediction strategy must occur with the paired identification of novel prognostic biomarkers and their underlying molecular regulatory mechanisms that help drive cancer recurrence/metastasis (i.e. recurrence biomarkers). Traditional clinical factors alone (such as TNM staging criteria) are no longer adequately prognostic for this purpose in the current molecular era. FOXC1 is a pivotal transcription factor that has been functionally implicated to drive cancer metastasis and has been demonstrated to be an independent predictor of heightened metastatic risk, at the time of initial diagnosis. In this review, we present our viewpoints on the master regulatory role that FOXC1 plays in mediating cancer stem cell traits that include cellular plasticity, partial EMT, treatment resistance, cancer invasion and cancer migration during cancer progression and metastasis. We also highlight potential therapeutic strategies to target cancers that are, or have evolved to become, “transcriptionally addicted” to FOXC1. The potential role of FOXC1 expression status in predicting the efficacy of these identified therapeutic approaches merits evaluation in clinical trials.

RETRACTED: Pancreatic cancer cells-derived exosomal long non-coding RNA CCAT1/microRNA-138-5p/HMGA1 axis promotes tumor angiogenesis

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concern was raised about the reliability of the Western blot results in Figs. 2B and 5I+J, which appear to have the same eyebrow shaped phenotype as many other publications tabulated here (https://docs.google.com/spreadsheets/d/149EjFXVxpwkBXYJOnOHb6RhAqT4a2llhj9LM60MBffM/edit#gid=0). In addition, Fig. 4B appears to show a digital composition of xenografted tumors. The journal requested the corresponding author comment on these concerns and provide the raw data. However the authors were not able to satisfactorily fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Regulation of host and virus genes by neuronal miR-138 favours herpes simplex virus 1 latency

MicroRNA miR-138, which is highly expressed in neurons, represses herpes simplex virus 1 (HSV-1) lytic cycle genes by targeting viral ICP0 messenger RNA, thereby promoting viral latency in mice. We found that overexpressed miR-138 also represses lytic processes independently of ICP0 in murine and human neuronal cells; therefore, we investigated whether miR-138 has targets besides ICP0. Using genome-wide RNA sequencing/photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation followed by short interfering RNA knockdown of candidate targets, we identified the host Oct-1 and Foxc1 messenger mRNAs as miR-138's targets, whose gene products are transcription factors important for HSV-1 replication in neuronal cells. OCT-1 has a known role in the initiation of HSV transcription. Overexpression of FOXC1, which was not known to affect HSV-1, promoted HSV-1 replication in murine neurons and ganglia. CRISPR-Cas9 knockout of FOXC1 reduced viral replication, lytic gene expression and miR-138 repression in murine neuronal cells. FOXC1 also collaborated with ICP0 to decrease heterochromatin on viral genes and compensated for the defect of an ICP0-null virus. In summary, miR-138 targets ICP0, Oct-1 and Foxc1 to repress HSV-1 lytic cycle genes and promote epigenetic gene silencing, which together enable favourable conditions for latent infection.

Global miRNA/proteomic analyses identify miRNAs at 14q32 and 3p21, which contribute to features of chronic iron-exposed fallopian tube epithelial cells

Malignant transformation of fallopian tube secretory epithelial cells (FTSECs) is a key contributing event to the development of high-grade serous ovarian carcinoma (HGSOC). Our recent findings implicate oncogenic transformative events in chronic iron-exposed FTSECs, including increased expression of oncogenic mediators, increased telomerase transcripts, and increased growth/migratory potential. Herein, we extend these studies by implementing an integrated transcriptomic and mass spectrometry-based proteomics approach to identify global miRNA and protein alterations, for which we also investigate a subset of these targets to iron-induced functional alterations. Proteomic analysis identified > 4500 proteins, of which 243 targets were differentially expressed. Sixty-five differentially expressed miRNAs were identified, of which 35 were associated with the “top” proteomic molecules (> fourfold change) identified by Ingenuity Pathway Analysis. Twenty of these 35 miRNAs are at the 14q32 locus (encoding a cluster of 54 miRNAs) with potential to be regulated by DNA methylation and histone deacetylation. At 14q32, miR-432-5p and miR-127-3p were ~ 100-fold downregulated whereas miR-138-5p was 16-fold downregulated at 3p21 in chronic iron-exposed FTSECs. Combinatorial treatment with methyltransferase and deacetylation inhibitors reversed expression of these miRNAs, suggesting chronic iron exposure alters miRNA expression via epigenetic alterations. In addition, PAX8, an important target in HGSOC and a potential miRNA target (from IPA) was epigenetically deregulated in iron-exposed FTSECs. However, both PAX8 and ALDH1A2 (another IPA-predicted target) were experimentally identified to be independently regulated by these miRNAs although TERT RNA was partially regulated by miR-138-5p. Interestingly, overexpression of miR-432-5p diminished cell numbers induced by long-term iron exposure in FTSECs. Collectively, our global profiling approaches uncovered patterns of miRNA and proteomic alterations that may be regulated by genome-wide epigenetic alterations and contribute to functional alterations induced by chronic iron exposure in FTSECs. This study may provide a platform to identify future biomarkers for early ovarian cancer detection and new targets for therapy.

Noncoding RNAs Associated with Therapeutic Resistance in Pancreatic Cancer

Therapeutic resistance is an inevitable impediment towards effective cancer therapies. Evidence accumulated has shown that the signaling pathways and related factors are fundamentally responsible for therapeutic resistance via regulating diverse cellular events, such as epithelial-to-mesenchymal transition (EMT), stemness, cell survival/apoptosis, autophagy, etcetera. Noncoding RNAs (ncRNAs) have been identified as essential cellular components in gene regulation. The expression of ncRNAs is altered in cancer, and dysregulated ncRNAs participate in gene regulatory networks in pathological contexts. An in-depth understanding of molecular mechanisms underlying the modulation of therapeutic resistance is required to refine therapeutic benefits. This review presents an overview of the recent evidence concerning the role of human ncRNAs in therapeutic resistance, together with the feasibility of ncRNAs as therapeutic targets in pancreatic cancer.

MicroRNA-138-5p targets the NFIB-Snail1 axis to inhibit colorectal cancer cell migration and chemoresistance

Background

Colorectal cancer ranks among the most lethal diseases worldwide. Although much progress has been made in research and treatment of colorectal cancer in recent years, the underlying mechanisms related to migration of the cancer cells and the reason for chemoresistance still remain unclear. In this research, we explored the underlying effect of miR-138-5p in colorectal cancer.

Methods

We used qRT-PCR to investigate the expression of miR-138-5p, Snail1, NFIB in colorectal cancer cells. Lentiviral vectors containing miR-138-5p mimics and inhibitors were constructed and transfected cells. Wound healing assay was applied to illustrate interferences on cell migration. Fluorouracial, doxorubicin, cisplat in were used to detect chemotherapy resistance. In order to identify target genes, bioinformatic methods were applied. Snail1 and NFIB protein expression in stable cell lines was detected using Western blot. Double luciferase and CHIP experiment were used to verify binding sites. We used rescue experiments to further explore the interactions among Snail1, NFIB and miR-138-5p.

Results

The expression of miR-138-5p in colorectal cancer cells was low. miR-138-5p inhibited cell migration in colorectal cancer, and could negatively regulate chemotherapy resistance. miR-138-5p targeted NFIB, and regulated Snail1 expression, which mediated colorectal cancer cell migration and chemotherapy resistance.

Conclusions

Our research indicates that miR-138-5p could be a crucial modulator controlling colorectal cancer cell migration and chemoresistance, by acting upon the NFIB-Snail1 axis. miR-138-5p has an emerging prospect to be exploited as a new target for colorectal cancer.

miR-138-5p suppresses glioblastoma cell viability and leads to cell cycle arrest by targeting cyclin D3

Although malignant glioblastoma (GBM) treatment has significantly improved in the past few decades, the prognosis of GBM remains unsatisfactory. MicroRNA (miR)-138-5p has been reported as a tumor suppressor in several types of human cancer; however, little is known about the function of miR-138-5p in GBM. The present study aimed to investigate the role of miR-138-5p in GBM as well as the underlying molecular mechanisms. The present study performed bioinformatics analysis, reverse transcription-quantitative (RT-q)PCR, western blotting, cell viability assays, colony formation assays, invasion assays and cell cycle analysis to investigate the biological function of miR-138-5p in both patient tissues and cell lines. In addition, miR-138-5p targets in GBM were predicted using Gene Expression Omnibus website and further validated by a dual luciferase reporter gene assay. The results revealed that miR-138-5p expression levels in patients with GBM from a Gene Expression Omnibus dataset were significantly downregulated. RT-qPCR analysis of miR-138-5p expression levels also revealed similar results in GBM tissues and cell lines. The upregulation of miR-138-5p expression levels using a mimic significantly inhibited the cell viability, colony formation and the G₀/G₁ to S progression in GBM cell lines, suggesting that miR-138-5p may be a tumor suppressor. Moreover, miR-138-5p was discovered to directly target cyclin D3 (CCND3), a protein that serves an important role in the cell cycle, and inhibited its expression. Finally, silencing CCND3 using small interfering RNA suppressed the viability of GBM cells. In conclusion, the results of the present study suggested that miR-138-5p may function as a tumor suppressor in GBM by targeting CCND3, indicating that miR-138-5p may be a novel therapeutic target for patients with GBM.

MiR-138-5p Inhibits the Proliferation of Gastric Cancer Cells by Targeting DEK

Background

Increasing evidence suggests that microRNAs (miRNAs) play critical roles in cancer progression. Therefore, investigating the function of miRNAs that are aberrantly expressed in gastric cancer (GC) and characterizing the involved underlying mechanism are essential for the treatment of gastric cancer. MiR-138-5p was found to be down-regulated in multiple cancers, which acted as a tumor suppressor in cancer progression; however, whether and how miR-138-5p regulates the malignant behaviors of GC has not been fully understood.

Methods

The level of miR-138-5p in GC tissues and cell lines was detected by RT-qPCR. The effects of miR-138-5p on the growth of GC cells were evaluated by the in vitro Cell Counting Kit-8 (CCK-8) assay, cell apoptosis, cell cycle analysis, wound-healing assay, and in vivo xenograft mice model. The targets of miR-138-5p were predicted using the miRDB online tool, confirmed by luciferase report assay and Western blot.

Results

MiR-138-5p was frequently decreased in GC tissues and cell lines. Decreased expression of miR-138-5p was significantly associated with the lymph node metastasis of GC patients. Overexpression of miR-138-5p suppressed GC cell proliferation, migration, increased cell apoptosis as well as inhibited the tumor growth in vivo. DEK oncogene was predicted as a potential target of miR-138-5p. MiR-138-5p bound the 3'-UTR of DEK and inhibited the level of DEK in GC cells. Restoration of DEK abrogated miR-138-5p overexpression-mediated suppression of GC cell proliferation and cell cycle arrest.

Conclusion

Our results demonstrated the anti-cancer role of miR-138-5p in GC by targeting DEK, which suggested miR-138-5p as a potential therapeutic target for the treatment of patient with GC.

In vivo miR-138-5p inhibition alleviates monocrotaline-induced pulmonary hypertension and normalizes pulmonary KCNK3 and SLC45A3 expression

BACKGROUND

The pathogenesis of pulmonary arterial hypertension (PAH) involves many signalling pathways. MicroRNAs are potential candidates involved in simultaneously coordinating multiple genes under such multifactorial conditions.

METHODS AND RESULTS

MiR-138-5p is overexpressed in pulmonary arterial smooth muscle cells (PASMCs) from PAH patients and in lungs from rats with monocrotaline-induced pulmonary hypertension (MCT-PH). MiR-138-5p is predicted to regulate the expression of the potassium channel KCNK3, whose loss is associated with the development and progression of PAH. We hypothesized that, in vivo, miR-138-5p inhibition would restore KCNK3 lung expression and subsequently alleviate PAH. Nebulization-based delivery of anti-miR-138-5p to rats with established MCT-PH significantly reduced the right ventricular systolic pressure and significantly improved the pulmonary arterial acceleration time (PAAT). These haemodynamic improvements were related to decrease pulmonary vascular remodelling, lung inflammation and pulmonary vascular cell proliferation in situ. In vivo inhibition of miR-138-5p restored KCNK3 mRNA expression and SLC45A3 protein expression in the lungs.

CONCLUSIONS

We confirmed that in vivo inhibition of miR-138-5p reduces the development of PH in experimental MCT-PH. The possible curative mechanisms involve at least the normalization of lung KCNK3 as well as SLC45A3 expression.

Identification and Validation of a Potent Multi-miRNA Signature for Prediction of Prognosis of Osteosarcoma Patients

Background

Osteosarcoma, the most common solid malignancy, has high incidence and mortality rates. We constructed a miRNA-based signature that can be used to assess the prognosis of osteosarcoma patients.

Material/Methods

The miRNA profile was derived from the Gene Expression Omnibus (GEO) website, with matched clinical records. The miRNA-based overall survival (OS)-predicting signature was established by LASSO Cox regression analysis. Receiver operating characteristic (ROC) curve and Kaplan-Meier (K-M) analyses were performed to examine the stability and discriminatory ability of the OS-predicting signatures. Pathway enrichment analyses were performed to uncover potential mechanisms.

Results

Three miRNAs (miR-153, miR-212, and miR-591) independently related to the OS were extracted to build a risk score formula. The ROC curve and K-M analyses revealed good discrimination ability of the OS signature for osteosarcoma patients in both the training cohort (P=0.00015, AUC=0.962) and the validation cohort (P=0.0065, AUC=0.793). As shown in multivariate analysis, the classifier showed favorable predictive accuracy similar to the recurrence status to be an independent risk factor for osteosarcoma. Furthermore, the nomogram showed a synergistic effect by combining the clinicopathological features with our classifier. Also, the enrichment analyses of the target genes may contribute to improved treatment of osteosarcoma.

Conclusions

The 3-miRNA-based classifier serves as an effective prognosis-predicting signature for osteosarcoma patients.

Downregulation of Transmembrane protein 40 by miR-138-5p Suppresses Cell Proliferation and Mobility in Clear Cell Renal Cell Carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) represents approximately 70% of RCC,as the most frequent histological subtype of RCC. MiR-138-5p, a tumor-related microRNA (miRNA), has been reported to be implicated in the diverse types of human malignancies, but its role in ccRCCremains unclear.

Objective

The study was designed to investigate the functional behaviors and regulatory mechanisms of miR-138-5p in ccRCC.

Materials and Methods

Quantitative real-time PCR and western blotting analyses were performed to determine the expression of miR-138-5p and TMEM40 in ccRCC tissues. Pearson's correlation coefficient was utilized to evaluate the correlation between miR-138-5p and TMEM40 expression. The function of miR-138-5p and TMEM40 in the cell proliferation, migration and invasion of ccRCC cells (786-O and ACHN) was assessed by CCK-8, colony formation, wound healing and transwell assay, respectively. A luciferase reporter assay was performed to confirm the direct binding of miR-138-5p to the target gene TMEM40.

Results

We found the expression of miR-138-5p was significantly down-regulated, while TMEM40 was remarkably up-regulated in ccRCC tissues. TMEM40 expression was discovered to be inversely correlated with miR-138-5p expression in ccRCC tissues. Functional studies demonstrated that miR-138-5p overexpression or TMEM40 knockdown significantly suppressed ccRCC cell proliferation, migration and invasion in vitro. Notably, we experimentally confirmed that miR-138-5p directly recognizes the 3'-UTR of the TMEM40 transcript and down-regulated its expression in ccRCC cells.

Conclusions

Taken together, our findings provide the first clues regarding the role of miR-138-5p as a tumor suppressor in ccRCC by directly targeting of TMEM40.

Long non-coding RNA MCM3AP-AS1 promotes growth and migration through modulating FOXK1 by sponging miR-138-5p in pancreatic cancer

Background

Pancreatic cancer (PC) is a type of malignant gastrointestinal tumor. Long non-coding RNA MCM3AP antisense RNA 1 (MCM3AP-AS1) has been reported to stimulate proliferation, migration and invasion in several types of tumors. However, the role of MCM3AP-AS1 in PC remains unclear.

Methods

MCM3AP-AS1, microRNA miR-138-5p (miR-138-5p) and FOXK1 levels were detected using quantitative real time PCR. Cell proliferation, migration and invasion were analyzed. Dual luciferase reporter assay was used to confirm the relationship between MCM3AP-AS1 and miR-138-5p, between miR-138-5p and FOXK1. Protein levels were identified using western blot analysis.

Results

MCM3AP-AS1 overexpression promoted proliferation, migration and invasion in PC cells. MCM3AP-AS1 silencing showed a suppressive effect on cell growth in PC cells. Moreover, MCM3AP-AS1 knockdown suppressed tumor growth in mice. Dual luciferase reporter assay demonstrated MCM3AP-AS1 could sponge microRNA-138-5p (miR-138-5p), and FOXK1 could bind with miR-138-5p. Positive correlation between MCM3AP-AS1 and FOXK1 was testified, as well as negative correlation between miR-138-5p and FOXK1. MCM3AP-AS1 promoted FOXK1 expression by targeting miR-138-5p, and MCM3AP-AS1 facilitated growth and invasion in PC cells by FOXK1.

Conclusion

MCM3AP-AS1 promoted growth and migration through modulating miR-138-5p/FOXK1 axis in PC, providing insights into MCM3AP-AS1/miR-138-5p/FOXK1 axis as novel candidates for PC therapy from bench to clinic.

FOXC1 Regulation of miR-31-5p Confers Oxaliplatin Resistance by Targeting LATS2 in Colorectal Cancer

Colorectal cancer (CRC) is the second leading cause of cancer-related illness worldwide and one of the most common malignancies. Therefore, colorectal cancer research and cases have gained increasing attention. Oxaliplatin (OXA) is currently used in first-line chemotherapy to treat stage III and stage IV metastatic CRC. However, patients undergoing chemotherapy often develop resistance to chemo drugs being used. Evidence has confirmed that microRNAs regulate downstream genes in cancer biology and thereby have roles related to tumor growth, proliferation, invasion, angiogenesis, and multi-drug resistance. The aim of our study is to establish whether miR-31-5p is an oncogene in human colorectal cancers that are resistant to OXA and further confirm its malignant phenotype-associated target molecule. From the results of miRNA microarray assay, we establish that miR-31-5p expression was upregulated in oxaliplatin-resistant (OR)-LoVo cells compared with parental LoVo cells. Moreover, through in vitro and in vivo experiments, we demonstrate that miR-31-5p and large tumor suppressor kinase 2 (LATS2) were inversely related and that miR-31-5p and Forkhead box C1 (FOXC1) were positively correlated in the same LoVo or OR-LoVo cells. Importantly, we reveal a novel drug-resistance mechanism in which the transcription factor FOXC1 binds to the miR-31 promoter to increase the expression of miR31-5p and regulate LATS2 expression, resulting in cancer cell resistance to OXA. These results suggest that miR-31-5p may be a novel biomarker involved in drug resistance progression in CRC patients. Moreover, the FOXC1/miR31-5p/LATS2 drug-resistance mechanism provides new treatment strategies for CRC in clinical trials.

MicroRNA-217/138-5p downregulation inhibits inflammatory response, oxidative stress and the induction of neuronal apoptosis in MPP+-induced SH-SY5Y cells

Parkinson's disease (PD) is a common neurodegenerative disease. Various microRNAs (miRNAs) have been reported to play important roles in cell growth regulation and inflammatory reaction. However, the detailed roles of miR-217 and miR-138-5p in PD progression remain to be investigated. In the present study, we explored the effects and underlying mechanisms of miR-217 and miR-138-5p on the inflammatory response, oxidative stress and the induction of neuronal apoptosis in an in vitro PD cell line model induced by 1-methyl-4-phenylpyridinium (MPP+). The results of the biological software analysis and luciferase reporter assays demonstrated that sirtuin 1 (SIRT1) was a direct target of miR-217 and miR-138-5p. MiR-217 and miR-138-5p exhibited a negative regulatory effect on the expression of SIRT1 in SH-SY5Y cells. In addition, the expression levels of miR-217 and miR-138-5p were increased, and SIRT1 expression was decreased in SH-SY5Y cells following MPP+ treatment. Loss-of-function experiments indicated that treatment of the cells with inhibitors against miR-217 and miR-138-5p promoted cell viability and superoxide dismutase (SOD) activity, while the induction of cell apoptosis, lactate dehydrogenase (LDH) activity, and the reactive oxygen species (ROS) release were inhibited in MPP+-induced SH-SY5Y cells. Moreover, the expression levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were reduced in MPP+-induced SH-SY5Y cells. Treatment of the cells with the miR-217 and the miR-138-5p inhibitors significantly inhibited the ratio of phosphorylated (p)-p65/p65 expression levels in MPP+-induced SH-SY5Y cells. In summary, the present study demonstrated that the miR-217/miR-138-5p/SIRT1 axis was involved in the progression of PD by regulating the inflammatory response and the induction of oxidative stress and neuronal apoptosis. The data provide new diagnostic and therapeutic strategies for PD patients.

MicroRNA-138 negatively regulates the hypoxia-inducible factor 1α to suppress melanoma growth and metastasis

Melanoma with rapid progression towards metastasis has become the deadliest form of skin cancer. However, the mechanism of melanoma growth and metastasis is still unclear. Here, we found that miRNA-138 was lowly expressed and hypoxia-inducible factor 1α (HIF1α) was highly expressed in patients’ melanoma tissue compared with the paracancerous tissues, and they had a significant negative correlation (r=−0.877, P<0.001). Patients with miRNA-138^low/HIF1α^high signatures were predominant in late stage III/IV of melanoma. Further, bioinformatic analysis demonstrated that miRNA-138 directly targeted HIF1α. We found that the introduction of pre-miRNA-138 sequences to A375 cells reduced HIF1α mRNA expression and suppressed cell proliferation, migration and invasion. Overexpression of miRNA-138 or inhibition of HIF1α significantly suppressed the growth and metastasis of melanoma in vivo. Our study demonstrates the role and clinical relevance of miRNA-138 and HIF1α in melanoma cell growth and metastasis, providing a novel therapeutic target for suppression of melanoma growth and metastasis.

Summary: Our study demonstrates the role and clinical relevance of miRNA-138 and HIF1α in melanoma cell growth and metastasis, providing a novel therapeutic target for suppression of melanoma growth and metastasis.

MiR-138-5p exacerbates hypoxia/reperfusion-induced heart injury through the inactivation of SIRT1-PGC-1α

OBJECTIVES

A drastic reduction in myocardial cell apoptosis plays a crucial role in the treatment/management of myocardial infarction, a major cardiovascular health challenge confronting the world, especially the Western world. Accumulating evidence indicates that the cardiotoxicity caused by the apoptotic machinery is partly regulated by miRNAs. The aim of this research is to investigate the role of miR-138-5p on hypoxia/reperfusion-induced heart injury.

METHODS

The expression of miR-138-5p was determined in heart tissue from myocardial infarction patients and rats. Rats were transfection with a miR-138-5p inhibitor to silence miR-138-5p. The cardiac function of rats was detected via echocardiography. SIRT1 and PGC-1α expression in cardiac infarction was detected via quantitative Real-time PCR (qPCR) and Western blot analysis, while the TUNEL assay was used to determine myocardial apoptosis.

RESULTS

Our observations showed that miR-138-5p expression was upregulated after the induction of myocardial infarction. The miR-138-5p inhibitor significantly improved cardiac function, increased the expression of SIRT1 and PGC-1α, and decreased the rate of myocardial apoptosis, whereas siRNA-SIRT1 reversed these protective effects.

CONCLUSIONS

In conclusion, our study demonstrated that miR-138-5p could promote cardiac ischemia injury via inhibition of the silent information regulator 1 and peroxisome proliferator-initiated receptor gamma and coactivator 1 alpha (SIRT1-PGC-1α) axis.

MicroRNA-138-5p inhibits cell migration, invasion and EMT in breast cancer by directly targeting RHBDD1

BACKGROUND

Accumulating studies have identified that microRNAs (miRNAs) are novel regulators acting as tumor suppressors or oncogenes in tumor progression. The aim of the study is to investigate the functional roles of miR-138-5p in breast cancer (BC) cells and explore the underlying mechanisms by identifying its target gene.

METHODS AND RESULTS

Our results first showed that miR-138-5p expression was remarkably decreased in BC tissues and cells using quantitative real-time PCR analysis. Forced expression of miR-138-5p significantly suppressed cell migration and invasion ability of BC using transwell assay. Moreover, miR-138-5p overexpression suppressed cell epithelial-mesenchymal transition (EMT) phenomenon of BC by upregulating E-cadherin expression, but downregulating N-cadherin and Vimentin expression. More importantly, rhomboid domain-containing protein 1 (RHBDD1) was predicted as the direct target of miR-138-5p by TargetScan and miRanda, which was subsequently confirmed by luciferase reporter assay in BC cells. RHBDD1 was up-regulated in BC tissues and negatively correlated with miR-138-5p expression. Furthermore, forced expression of miR-138-5p could down-regulate the expression of RHBDD1, but overexpression of RHBDD1 reversed the suppressive effects of miR-138-5p in BC cell migration, invasion and EMT.

CONCLUSIONS

Our findings revealed the tumor-suppressive role of miR-138-5p in regulating BC migration by targeting RHBDD1, suggesting that miR-138-5p negatively regulating EMT might be a therapeutic target in BC.

Overexpression of miR-138-5p suppresses MnCl2 -induced autophagy by targeting SIRT1 in SH-SY5Y cells

The mechanism of manganism caused by manganese (Mn), an important environmental risk factor for Parkinson's disease, is still unclear. Recent evidence suggested that autophagy participated in neurodegenerative diseases, in which microRNA played a crucial role. However, roles of microRNA in the aberrant autophagy that occurs in neurodegenerative diseases remains controversial. In nervous system, miRNA-138-5p is highly expressed and plays a key role in regulating memory and axon regeneration. Importantly, we also found that miR-138-5p expression decreased significantly after SH-SY5Y cells exposed to manganese chloride (MnCl₂ ) in previous study. To explore the role of miR-138-5p in Mn-induced autophagy, autophagy associated indicators were detected. And we found that MnCl₂ could induce autophagic dysregulation and inhibit expression of miR-138-5p. While the levels of LC3-II/LC3-I, Beclin1, and p62, the number of autophagosome formation significantly decreased after miR-138-5p over-expression, which demonstrated that miR-138-5p could clearly retard Mn-induced autophagy. In additional, we found there were classical and evolutionarily conserved miR-138-5p binding sites in 3'-UTR region of SIRT1, which was inhibited when overexpression of miR-138-5p. Therefore, it was speculated that elevated expression of SIRT1 may be resulted from inhibition of miR-138-5p after cells exposed to MnCl₂ . Finally, we found that SIRT1 inhibitor EX-527 suppressed Mn-induced autophagy as well as miR-138-5p, while the suppression was reversed by SIRT1-specific activator SRT1720. These results indicated that overexpression of miR-138-5p suppressed Mn-induced autophagy by targeting SIRT1.

microRNA-138-5p as a Worse Prognosis Biomarker in Pediatric, Adolescent, and Young Adult Osteosarcoma

Osteosarcoma (OS) is the most common primary malignant bone tumor with two peaks of incidence, in early adolescence and the elderly. Patients affected with this malignancy often present metastatic disease at diagnosis, and despite multimodality therapy, survival has not improved substantially over the past 3 decades. Recently, miR-138-5p, proposed as a crucial intracellular mediator of invasion, has been recognized to target the Rho-associated coiled-coil containing protein kinase 2 (ROCK2). Dysregulation of ROCK1 and ROCK2 was also described in OS, being associated to higher metastasis incidence and worse prognosis. Nonetheless, the specific roles of miR-138-5p in pediatric and young adult OS and its ability to modulate these kinases remain to be established. Thus, in the present study, the expression levels miR-138-5p were evaluated in a consecutive cohort of exclusively pediatric and young adult primary OS samples. In contrast to previous reports that included adult tissues, our results showed upregulation of miR-138-5p associated with reduced event-free survival and relapsed cases. In parallel, ROCK1 mRNA levels were significantly reduced in tumor samples and negatively correlated with miR-138-5p. Similar correlations were observed after studying the profiles of ROCK1 and ROCK2 by immunohistochemistry. Our data present miR-138-5p as a consistent prognostic factor in pediatric and young adult OS, reinforcing its participation in the post-transcriptional regulation of ROCK kinases.

Depletion of the lncRNA RP11-567G11.1 inhibits pancreatic cancer progression

BACKGROUND

Pancreatic cancer is one of the most lethal malignancies, as demonstrated by its 5-year survival rate of less than 10%. The poor response of pancreatic cancer to conventional therapeutics, especially against cancer stem cells (CSCs), is the primary obstacle to improving patient survival. Emerging evidence indicates that the long non-coding RNA (lncRNA) RP11-567G11.1 is up-regulated in pancreatic cancer tissues and that its expression is associated with poor prognosis. This study aimed to elucidate the mechanism by which RP11-567G11.1 influences survival in pancreatic cancer.

METHODS

We evaluated the expression of RP11-567G11.1 in pancreatic cancer tissues via in situ hybridization. We also constructed RP11-567G11.1 knockdown cell models and used CCK8 and flow cytometry to detect the function of this lncRNA. Western blotting and qPCR were used to detect the expression levels of factors related to RP11-567G11.1.

RESULTS

The results illustrated that RP11-567G11.1 was significantly up-regulated in poorly differentiated pancreatic cancer tissues as compared to its expression in non-tumor tissues. Additionally, depletion of RP11-567G11.1 in pancreatic cancer cells inhibited proliferation and cell cycle progression, induced apoptosis, suppressed the stem cell-like phenotype, and increased sensitivity to gemcitabine. Also depletion of RP11-567G11.1 in pancreatic cancer cells inhibited factors downstream of the NOTCH signaling pathway.

CONCLUSION

RP11-567G11.1 plays a crucial role in pancreatic cancer. Importantly, depletion of RP11-567G11.1 boosts the sensitivity of pancreatic cancer cells to gemcitabine, suggesting that this lncRNA is a promising target for pancreatic cancer treatment.

FUS/circ_002136/miR-138-5p/SOX13 feedback loop regulates angiogenesis in Glioma

Background

Angiogenesis plays a critical role in the progression of glioma. Previous studies have indicated that RNA-binding proteins (RBPs) interact with RNAs and participate in the regulation of the malignant behaviors of tumors. As a type of endogenous non-coding RNAs, circular RNAs (circRNAs) are abnormally expressed in various cancers and are involved in diverse tumorigeneses including angiogenesis.

Methods

The expression levels of FUS, circ_002136, miR-138-5p, SOX13, and SPON2 were determined using quantitative real-time PCR (qRT-PCR) and western blot. Transient cell transfection was performed using the Lipofectamine 3000 reagent. The RNA-binding protein immunoprecipitation (RNA-IP) and the RNA pull-down assays were used to detect the interaction between FUS and circ_002136. The dual-luciferase reporter assay system was performed to detect the binding sites of circ_002136 and miR-138-5p, miR-138-5p and SOX13. The chromatin immunoprecipitation (ChIP) assays were used to examine the interactions between transcription factor SOX13 and its target proteins .

Results

We demonstrated that down-regulation of FUS or circ_002136 dramatically inhibited the viability, migration and tube formation of U87 glioma-exposed endothelial cells (GECs). MiR-138-5p was down-regulated in GECs and circ_002136 functionally targeted miR-138-5p in an RNA-induced silencing complex (RISC). Inhibition of circ_002136, combined with the restoration of miR-138-5p, robustly reduced the angiogenesis of GECs. As a target gene of miR-138-5p, SOX13 was overexpressed in GECs and was proved to be involved in circ_002136 and miR-138-5p-mediated angiogenesis in gliomas. In addition, we found that SOX13 was directly associated with and activated the SPON2 promoter, thereby up-regulating the expression of SPON2 at the transcriptional level. Knockdown of SPON2 suppressed the angiogenesis in GECs. More important, SOX13 activated the FUS promoter and increased its expression, forming a feedback loop.

Conclusion

Our data suggests that the feedback loop of FUS/circ_002136/miR-138-5p/SOX13 played a crucial role in the regulation of angiogenesis in glioma. This also provides a potential target and an alternative strategy for combined glioma therapy.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1065-7) contains supplementary material, which is available to authorized users.

CircRNA ZNF609 functions as a competitive endogenous RNA to regulate FOXP4 expression by sponging miR-138-5p in renal carcinoma

Circular RNA (circRNA) play important roles in the pathological processes of many diseases. By analyzing the results of the GSE100186 chip, we found that the expression of circRNA ZNF609 (circ-ZNF609) was significantly increased in renal cell carcinoma. Recently, there are studies showing that circ-ZNF609 can regulate cell proliferation and invasion ability of various cells. In this study, we investigated whether circ-ZNF609 may affect cell invasion and proliferation in renal carcinoma. Quantitative reverse transcription polymerase chain reaction was performed to detect the expression of circ-ZNF609 in renal carcinoma cell lines and renal epithelial cells. The direct interaction between microRNA-138-5p (miR-138-5p) and forkhead box P4 (FOXP4) or circ-ZNF609 was confirmed by luciferase reporter assay and RNA immunoprecipitation assay. We use Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine, and Matrigel assays to assess the effect of miR-138-5p or circ-ZNF609 on cell proliferation or invasion ability. And we found that circ-ZNF609 is significantly increased in renal carcinoma cell lines. In addition, the high expression of circ-ZNF609 promotes cell proliferation and invasion ability. In short, our current study reveals the role of the circ-ZNF609/miR-138-5p/FOXP4 regulatory network in renal carcinoma and provides a new perspective for the pathogenesis of renal carcinoma.

MicroRNA-661 expression is upregulated in pancreatic ductal adenocarcinoma and promotes cell proliferation

Deregulation of microRNA (miRNA/miR) expression has been implicated in the development of pancreatic ductal adenocarcinoma (PDAC). However, the role of miR-661 in PDAC remains unknown. In the present study, it was revealed that miR-661 expression was significantly upregulated in PDAC tissues compared with that in adjacent normal tissues by using reverse transcription-quantitative polymerase chain reaction assays. Higher miR-661 expression revealed a positive association with lymph node metastasis, an advanced T stage and a poor prognosis in patients with PDAC. Furthermore, ectopic expression of miR-661 significantly promoted the cell proliferation ability in PDAC cell lines, and simultaneously promoted Wnt signaling pathway-related protein expression of β-catenin, transcription factor 4 and cyclin D1 in vitro. However, the downregulation of miR-661 revealed reverse effects. Thus, the results of the present study indicated that miR-661 may function as a prognostic marker and provide insight for pancreatic cancer treatment.

Liquid biopsy in pancreatic cancer: the beginning of a new era

With dismal survival rate pancreatic cancer remains one of the most aggressive and devastating malignancy. Predominantly, due to the absence of a dependable methodology for early identification and limited therapeutic options for advanced disease. However, it takes over 17 years to develop pancreatic cancer from initiation of mutation to metastatic cancer; therefore, if diagnosed early; it may increase overall survival dramatically, thus, providing a window of opportunity for early detection. Recently, genomic expression analysis defined 4 subtypes of pancreatic cancer based on mutated genes. Hence, we need simple and standard, minimally invasive test that can monitor those altered genes or their associated pathways in time for the success of precision medicine, and liquid biopsy seems to be one answer to all these questions. Again, liquid biopsy has an ability to pair with genomic tests. Additionally, liquid biopsy based development of circulating tumor cells derived xenografts, 3D organoids system, real-time monitoring of genetic mutations by circulating tumor DNA and exosome as the targeted drug delivery vehicle holds lots of potential for the treatment and cure of pancreatic cancer. At present, diagnosis of pancreatic cancer is frantically done on the premise of CA19-9 and radiological features only, which doesn't give a picture of genetic mutations and epigenetic alteration involved. In this manner, the current diagnostic paradigm for pancreatic cancer diagnosis experiences low diagnostic accuracy. This review article discusses the current state of liquid biopsy in pancreatic cancer as diagnostic and therapeutic tools and future perspectives of research in the light of circulating tumor cells, circulating tumor DNA and exosomes.

The tumor suppressor miR-138-5p targets PD-L1 in colorectal cancer

microRNAs (miRNAs) play critical roles in cancer development and progression. This study investigated the effects of miR-138-5p in human colorectal cancer (CRC) development. miR-138-5p was frequently downregulated in CRC tissues and was associated with advanced clinical stage, lymph node metastasis and poor overall survival. We found that miR-138-5p decreased expression of programmed cell death ligand 1 (PD-L1) through interaction with its PD-L1 3′ untranslated region. miR-138-5p also dramatically suppressed CRC cell growth in vitro and inhibited tumorigenesis in vivo. PD-L1 and miR-138-5p levels were inversely correlated in human CRC tumors, and miR-138-5p inhibited PD-L1 expression in tumor models. These results suggest that miR-138-5p is a tumor suppressor in CRC, and its effects are exerted at least partially through PD-L1 downregulation. Low miR-138-5p and high PD-L1 levels correlated with shorter overall CRC patient survival, indicating that miR-138-5p and PD-L1 may serve as CRC biomarkers for risk group assignment, optimal therapy selection and clinical outcome prediction. Targeting PD-L1, possibly by administering miR-138-5p mimics, might be a clinically effective anti-CRC therapeutic strategy.

Pancreatic Cancer Diagnosis and Management: Has the Time Come to Prick the Bubble?

Pancreatic cancer (PC) is associated with poor prognosis and very dismal survival rates. The most effective possibility of cure is tumor resection, which is only possible in about 15% of patients diagnosed at early stages of disease progression. Recent whole-genome sequencing studies pointed genetic alterations in 12 core signaling pathways in PC. These observations hint at the possibility that the initial mutation in PC might appear nearly 20 years before any symptoms occur, suggesting that a large window of opportunity may exist for early detection. Biomarkers with the potential to identify pre-neoplastic disease or very early stages of cancer are of great promise to improve patient survival. The concept of liquid biopsy refers to a minimally invasive sampling and analysis of liquid biomarkers that can be isolated from body fluids, primarily blood, urine and saliva. A myriad of circulating molecules may be useful as tumor markers, including cell-free DNA (cfDNA), cell-free RNA (cfRNA), circulating tumor cells (CTC), circulating tumor proteins, and extracellular vesicles, more specifically exosomes. In this review, we discuss with more detail the potential role of exosomes in several aspects related to PC, from initiation to tumor progression and its applicability in early detection and treatment. Exosomes are small circulating extracellular vesicles of 50-150 nm in diameter released from the plasma membrane by almost all cells and exhibit some advantages over other biomarkers. Exosomes are central players of intercellular communication and they have been implicated in a series of biological process, including tumorigenesis, migration and metastasis. Several exosomal microRNAs and proteins have been observed to distinguish PC from benign pancreatic diseases and healthy controls. Besides their possible role in diagnosis, understanding exosomes functions in cancer has clarified the importance of microenvironment in PC progression as well as its influence in proliferation, metastasis and resistance to chemotherapy. Increasing knowledge on cancer exosomes provides valuable insights on new therapeutic targets and can potentially open new strategies to treat this disease. Continuous research is needed to ascertain the reliability of using exosomes and their content as potential biomarkers, so that, hopefully, in the near future, they will provide the opportunity for early diagnosis, treatment intervention and increase survival of PC patients.

Seven-microRNA panel for lung adenocarcinoma early diagnosis in patients presenting with ground-glass nodules

Background

MicroRNA (miRNA) expression is correlated with tumor histology, differentiation, invasiveness and treatment outcome. We aimed to identify miRNAs whose differential expression might enable early diagnosis of lung adenocarcinoma in patients presenting with ground-glass nodules (GGNs).

Methods

To identify potential miRNAs of interest, we analyzed the miRNA expression profile of tumor and adjacent non-para-tumor tissue in three participants by next-generation sequencing (NGS). We then assessed the expression levels of the miRNAs of interest in 73 lung adenocarcinomas presenting with GGNs with matched adjacent non-tumor tissue by quantitative real-time polymerase chain reaction (qRT-PCR). We also detected the miRNA panel in 66 lung benign diseases and 66 lung adenocarcinomas presenting with GGN lesion tissues by qRT-PCR. Target genes of our selected miRNA panel were predicted using Miranda with default parameters.

Results

Twenty-three miRNAs showed differential expression between tumor and adjacent non-tumor tissue by NGS. Five miRNAs exhibited higher expression in tumor tissue compared to adjacent non-tumor tissue (P<0.05); 18 miRNAs demonstrated lower expression in tumor tissue versus adjacent non-tumor tissue (P<0.05). When qRT-PCR was performed for the 23 miRNAs identified by NGS in the pilot stage, seven were found to have statistically significant expression in tumor versus adjacent non-tumor tissue (P<0.05). The sensitivity and specificity of seven-miRNA panel were 86.4% and 60.6%, respectively.

Conclusion

The predicted targets of our miRNAs of interest are frequently associated with cancer signaling pathways. We developed a miRNA panel that could potentially predict the presence of lung adenocarcinoma in patients presenting with GGNs.

miR-138-5p acts as a tumor suppressor by targeting hTERT in human colorectal cancer

Colorectal cancer (CRC) is the second most common cancer in the world. The incidence of this cancer is increasing in the developing countries. Mechanism of CRC tumorigenesis has been widely studied at the molecular levels, and has been recently proposed microRNAs as novel players in CRC. It has been reported that microRNA-138-5p (miR-138-5p) play key roles in different kinds of human cancers. However, the roles and underlying molecular mechanisms of miR-138-5p in CRC have not been adequately elucidated. Thus, the aim of the present study was to investigate the roles and possible regulatory mechanisms of miR-138-5p in CRC. In this study, we demonstrated that miR-138-5p was significantly down-regulated in CRC tissue samples and cell lines. Functional analyses indicated that the overexpression of miR-138-5p significantly delayed cell proliferation, reduced colony formation and increased apoptosis in CRC cell lines. Moreover, human telomerase reverse transcriptase (hTERT), an important oncogene in the management of tumors, was confirmed as a direct target of miR-138-5p in CRC cells. We also found that the hTERT expression was increased in CRC tissues and was inversely correlated with miR-138-5p. Further study showed that the restoration of hTERT expression by an overexpressing plasmid could reverse the effects of miR-138-5p on proliferation and apoptosis of CRC cells. Taken together, these data defines a major suppresses proliferation and promotes apoptosis role for miR-138-5p, a microRNA functions as a tumor suppressor in CRC, by directly targeting hTERT, which would be provide a new strategy for future CRC therapies.

FOXC1 in cancer development and therapy: deciphering its emerging and divergent roles

Forkhead box C1 (FOXC1) is an essential member of the forkhead box transcription factors and has been highlighted as an important transcriptional regulator of crucial proteins associated with a wide variety of carcinomas. FOXC1 regulates tumor-associated genes and is regulated by multiple pathways that control its mRNA expression and protein activity. Aberrant FOXC1 expression is involved in diverse tumorigenic processes, such as abnormal cell proliferation, cancer stem cell maintenance, cancer migration, and angiogenesis. Herein, we review the correlation between the expression of FOXC1 and tumor behaviors. We also summarize the mechanisms of the regulation of FOXC1 expression and activity in physiological and pathological conditions. In particular, we focus on the pathological processes of cancer targeted by FOXC1 and discuss whether FOXC1 is good or detrimental during tumor progression. Moreover, FOXC1 is highlighted as a clinical biomarker for diagnosis or prognosis in various human cancers. The information reviewed here should assist in experimental designs and emphasize the potential of FOXC1 as a therapeutic target for cancer.

MicroRNA-138 targets SP1 to inhibit the proliferation, migration and invasion of hepatocellular carcinoma cells

The identification of microRNAs (miRNAs/miRs) has enabled the improved understanding of the carcinogenesis and progression of hepatocellular carcinoma (HCC). miRNAs are small non-coding RNAs comprised of 19-24 nucleotides that regulate the expression of target genes. In the present study, miR-138 was demonstrated to be downregulated in human HCC tissues and cell lines. Restoration of miR-138 expression repressed the proliferation, migration and invasion of HCC cells. Furthermore, specificity protein 1 (SP1) was identified as a target gene of miR-138 in HCC using bioinformatics analysis, luciferase reporter assay, reverse transcription-quantitative polymerase chain reaction and western blot analysis. Knockdown of SP1 produced similar suppressive effects to those induced by miR-138 overexpression in HCC cells. These results indicate that miR-138 targeted SP1 to repress the growth, migration and invasion of HCC cells, and may therefore represent a therapeutic target in human HCC.

MicroRNA-138 suppresses cell proliferation and invasion of renal cell carcinoma by directly targeting SOX9

An accumulating number of studies have reported that the expression levels of microRNAs (miRNAs/miRs) are dysregulated in a variety of human cancer types, including renal cell carcinoma (RCC). miRNAs play essential functions in tumorigenesis and the progression of tumors by serving as oncogenes or tumor suppressors. Recently, the expression and functions of miR-138 have been studied in a number of human cancer types; however, its role in RCC remains poorly understood. In the present study, the results revealed that miR-138 was significantly downregulated in RCC cell lines and tissues, and that low expression levels of miR-138 were correlated with histological grade, tumor stage and lymph node metastasis. In functional studies, restoration of miR-138 expression inhibited cell proliferation and invasion of ACHN and A498 cells. In addition, SOX9 was validated as a direct target gene of miR-138 in RCC. SOX9 knockdown inhibited cell proliferation and invasion of RCC, with a similar effect to that induced by miR-138, rendering SOX9 a functional target of miR-138 in the disease. These findings indicate that miR-138 may present a novel target for therapeutic strategies in RCC.

Overexpression of Topoisomerase 2-Alpha Confers a Poor Prognosis in Pancreatic Adenocarcinoma Identified by Co-Expression Analysis

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is the fourth most common cause of human cancer-related death in the developed countries. Its progression and prognosis are influenced by a complex network of gene interactions.

AIMS

The purpose of this study is to explore key genes associated with pancreatic ductal adenocarcinoma and to predict the possible mechanisms.

METHODS

A weighted gene co-expression network was constructed to identify gene modules associated with the progression of PDAC.

RESULTS

In the significant module (R ² = 0.30), a total of 20 network hub genes were identified, 6 of which were also hub nodes in the protein-protein interaction network of the module genes. In validation, TOP2A has a higher correlation than other hub genes. Also, in the test set (n = 118), TOP2A was more highly expressed in PDAC than normal pancreas samples (P < 0.001). What is more, gene set enrichment analysis demonstrated that eight gene sets (n = 118), "nucleotide excision repair," "P53 signaling pathway," "proteasome," "mismatch repair," "homologous recombination," "DNA replication," "cell cycle," and "base excision repair," were enriched (FDR < 0.05). In gene ontology analysis, TOP2A in the enriched set was associated with cell cycle and cell division. Furthermore, survival analysis indicated that higher expression of TOP2A resulted in the lower overall survival time as well as disease-free survival time.

CONCLUSION

TOP2A was identified in association with the progression and prognosis of PDAC probably by regulating cell cycle and p53 signaling pathway.

MicroRNA‑138‑5p regulates neural stem cell proliferation and differentiation in vitro by targeting TRIP6 expression

Research on neural stem cells (NSCs) has recently focused on microRNAs (miRNAs), a class of small non-coding RNAs that have crucial roles in regulating NSC proliferation and differentiation. In the present study, a quantitative-polymerase chain reaction assay revealed that the expression of miRNA (miR)-138-5p was significantly decreased during neural differentiation of NSCs in vitro. Overexpression of miR-138-5p reduced NSC proliferation and increased NSC differentiation. Furthermore, suppression of miR-138-5p via transfection with a miRNA inhibitor enhanced NSC proliferation and attenuated NSC differentiation. Additionally, expression of thyroid hormone receptor interacting protein 6 (TRIP6), a critical regulator of NSCs, was negatively correlated with the miR-138-5p level. A luciferase assay demonstrated that miR-138-5p regulate TRIP6 by directly binding the 3′-untranslated region of the mRNA. Additionally, upregulation of TRIP6 rescued the NSC proliferation deficiency induced by miR-138-5p and abolished miR-138-5p-promoted NSCs differentiation. By contrast, downregulation of TRIP6 produced the opposite effect on proliferation and differentiation of NSCs transfected with anti-miR-138-5p. Taken together, the data suggest that miR-138-5p regulates NSCs proliferation and differentiation, and may be useful in developing novel treatments for neurological disorders via manipulation of miR-138-5p in NSCs.

CREPT regulated by miR-138 promotes breast cancer progression

CREPT (also known as RPRD1B) function as an oncogene and is highly expressed in several kinds of cancers. However, the distribution and clinical significance of CREPT in breast cancer (BC) still not clarified. In this study, we found that the CREPT expression is greatly upregulated in BC tissues and cell lines. Moreover, the CREPT expression was significantly associated with tumor differentiation and metastasis. Next, the functional assay of CREPT showed that CREPT could promote BC proliferation and invasion both in vitro and in vivo. Dual-luciferase reporter assay indicated that miR-138 regulated the expression of CREPT by binding to its 3'-UTR. miR-138 is downregulated and inversely correlated with CREPT expression in BCs. Overexpression of miR-138 suppressed tumor growth and invasion, these effects could be reversed by re-expressing CREPT. Mechanistically, CREPT regulated β-catenin/TCF4/cyclin D1 pathway in BC. In conclusion, the data suggested that miR-138/CREPT involved BC progression, providing potential therapeutic targets for BC.

Decreased Expression of miR-138-5p by lncRNA H19 in Cervical Cancer Promotes Tumor Proliferation

MicroRNAs (miRNAs) play important roles in the carcinogenesis of cervical cancer. However, the expression and underlying mechanisms of miRNA in cervical cancer progression remain unclear. In the present study, our data showed that the expression of miR-138-5p was significantly downregulated in cervical cancer tissues, and decreased expression of miR-138-5p was correlated with advanced FIGO stage, poor differentiation, lymph node metastasis, and poor overall survival of cervical cancer patients. Function assays showed that overexpression of miR-138-5p reduced cervical cancer cell proliferation, arrested cells in the G₀/G₁ phase, and induced cell apoptosis in vitro. Remarkably, SIRT1 was confirmed as a direct target of miR-138-5p in cervical cancer, and miR-138-5p exerted the reduced tumor functions by suppressing SIRT1 expression. Moreover, we further identified that lncRNA H19 could act as a molecular sponge of miR-138-5p in cervical cancer progression. Taken together, these results suggested that miR-138-5p could suppress cervical cancer cell progression by targeting SIRT1.

Long non-coding RNA MEG3 inhibits cell growth of gliomas by targeting miR-93 and inactivating PI3K/AKT pathway

Gliomas are the most common cancers in the brain, accompanied with high morbility, occurrence, disability and mortality. Long non-coding RNAs (lncRNAs) have been proposed as promoter or inhibitor in many cancer processes. Previous findings have indicated that lncRNA-maternally expressed gene 3 (MEG3) is involved in tumorigenesis of several cancers, including glioma. However, the underlying mechanism of MEG3 in glioma remains elusive. In our study, MEG3 was found downregulated in glioma tissues compared with normal brain tissues. Downregulated expression of MEG3 was also detected in two human glioma cell lines (U-251, M059J) compared with normal astrocyte cells. MEG3 was then overexpressed by ligating to a lentiviral vector. Overexpressed MEG3 inhibited the proliferation of U-251 cells, and restrained the expression of proliferation marker proteins Ki67 and proliferating cell nuclear antigen (PCNA). However, cell apoptosis rate of U-251 cells and the expression of apoptosis marker proteins (caspase-3 and caspase-9) were elevated by MEG3. Furthermore, miR-93 was predicted a direct target of lncRNA-MEG3 by bioinformatics analysis. Overexpressed MEG3 counteracted the role of miR-93 in facilitating proliferation and inhibiting apoptosis in U-251 cells. Moreover, MEG3 restained the activation of phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT) pathway by reducing cytomembrane translocation of AKT. Finally, the in vivo experiment revealed that MEG3 strongly reduced tumor growth, tumor volume and the expression of Ki67 and PCNA. lncRNA-MEG3 also inhibited the level of miR-93 and the expression of PI3K/AKT pathway related proteins in vivo. Taken together, our research indicated a MEG3-miR-93-PI3K-AKT pathway in regulating the growth of glioma, providing a promising therapy for glioma.

Forkhead box C1 is targeted by microRNA-133b and promotes cell proliferation and migration in osteosarcoma

Forkhead box C1 (FOXC1) has been demonstrated to act as an oncogene in a number of malignant tumors, though its underlying mechanism of action in osteosarcoma (OS) remains unknown. The present study evaluated the expression and regulatory role of FOXC1 in OS. Reverse transcription-quantitative polymerase chain reaction and western blot data indicated that FOXC1 was significantly upregulated in OS tissues and cell lines when compared with adjacent non-tumor tissues (P<0.001) and normal human osteoblast cells (P<0.01), respectively. Moreover, levels of FOXC1 expression were significantly higher in OS at advanced clinical stage (III–IV) when compared with that at low clinical stage (I–II; P<0.001). Knockdown of FOXC1 expression caused a significant decrease in the proliferation and migration of OS U2OS cells (P<0.01), while overexpression of FOXC1 significantly promoted U2OS cell proliferation and migration (P<0.01), relative to control U2OS cells. Furthermore, FOXC1 was identified as a direct target of microRNA (miR)-133b, a reported tumor-suppressive miR in OS. The protein expression of FOXC1 was negatively regulated by miR-133b in U2OS cells (P<0.01), and miR-133b expression was inversely correlated with FOXC1 expression in OS. In conclusion, the present study demonstrated that FOXC1, targeted by miR-133b, may promote cell proliferation and migration in OS. Thus, FOXC1 may be a potential therapeutic target in the treatment of OS.

FoxC1 promotes epithelial-mesenchymal transition through PBX1 dependent transactivation of ZEB2 in esophageal cancer

Esophageal cancer (EC) was one of the most lethal malignancies worldwide with intricate mechanisms. Here we reported that Forkhead box C1 (FoxC1), a member of the forkhead family transcription factors, was up-regulated in EC tissues and cell lines in comparison with controls. FoxC1 levels were negatively correlated with tumor stage, lymph node metastasis and survival status of EC patients. Knockdown of FoxC1 inhibited the proliferation, colony formation and epithelial-mesenchymal transition (EMT) of EC cells, while overexpression of FoxC1 promoted these biological behaviors. Mechanically, serial deletion and chromatin immunoprecipitation assays showed that ZEB2, a well-reported transcriptional suppressor of E-cadherin, was a direct transcriptional target of FoxC1. Moreover, FoxC1 was recruited to the ZEB2 promoter by its interaction with the pioneer transcription factor pre-B-cell leukemia homeobox 1 (PBX1). Importantly, significant correlation between levels of FoxC1 and ZEB2 was observed in EC tissues and the two proteins could be used as prognostic biomarkers together. Hence, our results revealed a critical role of FoxC1 in the EMT process of EC and uncovered a novel mechanism for the regulation of ZEB2-E-cadherin axis in EC.