MicroRNA-218 inhibits cell invasion and migration of pancreatic cancer via regulating ROBO1

Chimeric antigen receptor-immune cells against solid tumors: Structures, mechanisms, recent advances, and future developments

ABSTRACT

The advent of chimeric antigen receptor (CAR)-T cell immunotherapies has led to breakthroughs in the treatment of hematological malignancies. However, their success in treating solid tumors has been limited. CAR-natural killer (NK) cells have several advantages over CAR-T cells because NK cells can be made from pre-existing cell lines or allogeneic NK cells with a mismatched major histocompatibility complex (MHC), which means they are more likely to become an "off-the-shelf" product. Moreover, they can kill cancer cells via CAR-dependent/independent pathways and have limited toxicity. Macrophages are the most malleable immune cells in the body. These cells can efficiently infiltrate into tumors and are present in large numbers in tumor microenvironments (TMEs). Importantly, CAR-macrophages (CAR-Ms) have recently yielded exciting preclinical results in several solid tumors. Nevertheless, CAR-T, CAR-NK, and CAR-M all have their own advantages and limitations. In this review, we systematically discuss the current status, progress, and the major hurdles of CAR-T cells, CAR-NK cells, and CAR-M as they relate to five aspects: CAR structure, therapeutic mechanisms, the latest research progress, current challenges and solutions, and comparison according to the existing research in order to provide a reasonable option for treating solid tumors in the future.

Cancer biotherapy: review and prospect

Malignant tumors pose a grave threat to the quality of human life. The prevalence of malignant tumors in China is steadily rising. Presently, clinical interventions encompass surgery, radiotherapy, and pharmaceutical therapy in isolation or combination. Nonetheless, these modalities fail to completely eradicate malignant tumor cells, frequently leading to metastasis and recurrence. Conversely, tumor biotherapy has emerged as an encouraging fourth approach in preventing and managing malignant tumors owing to its safety, efficacy, and minimal adverse effects. Currently, a range of tumor biotherapy techniques are employed, including gene therapy, tumor vaccines, monoclonal antibody therapy, cancer stem cell therapy, cytokine therapy, and adoptive cellular immunotherapy. This study aims to comprehensively review the latest developments in biological treatments for malignant tumors.

The nerve cells in gastrointestinal cancers: from molecular mechanisms to clinical intervention

Gastrointestinal (GI) cancer is a formidable malignancy with significant morbidity and mortality rates. Recent studies have shed light on the complex interplay between the nervous system and the GI system, influencing various aspects of GI tumorigenesis, such as the malignance of cancer cells, the conformation of tumor microenvironment (TME), and the resistance to chemotherapies. The discussion in this review first focused on exploring the intricate details of the biological function of the nervous system in the development of the GI tract and the progression of tumors within it. Meanwhile, the cancer cell-originated feedback regulation on the nervous system is revealed to play a crucial role in the growth and development of nerve cells within tumor tissues. This interaction is vital for understanding the complex relationship between the nervous system and GI oncogenesis. Additionally, the study identified various components within the TME that possess a significant influence on the occurrence and progression of GI cancer, including microbiota, immune cells, and fibroblasts. Moreover, we highlighted the transformation relationship between non-neuronal cells and neuronal cells during GI cancer progression, inspiring the development of strategies for nervous system-guided anti-tumor drugs. By further elucidating the deep mechanism of various neuroregulatory signals and neuronal intervention, we underlined the potential of these targeted drugs translating into effective therapies for GI cancer treatment. In summary, this review provides an overview of the mechanisms of neuromodulation and explores potential therapeutic opportunities, providing insights into the understanding and management of GI cancers.

Biological and therapeutic viewpoints towards role of miR-218 in human cancers: Revisiting molecular interactions and future clinical translations

Understanding the exact pathogenesis of cancer is difficult due to heterogenous nature of tumor cells and multiple factors that cause its initiation and development. Treatment of cancer is mainly based on surgical resection, chemotherapy, radiotherapy and their combination, while gene therapy has been emerged as a new kind of therapy for cancer. Post-transcriptional regulation of genes has been of interest in recent years and among various types of epigenetic factors that can modulate gene expression, short non-coding RNAs known as microRNAs (miRNAs) have obtained much attention. The stability of mRNA decreases by miRNAs to repress gene expression. miRNAs can regulate tumor malignancy and biological behavior of cancer cells and understanding their function in tumorigenesis can pave the way towards developing new therapeutics in future. One of the new emerging miRNAs in cancer therapy is miR-218 that increasing evidence highlights its anti-cancer activity, while a few studies demonstrate its oncogenic function. The miR-218 transfection is promising in reducing progression of tumor cells. miR-218 shows interactions with molecular mechanisms including apoptosis, autophagy, glycolysis and EMT, and the interaction is different. miR-218 induces apoptosis, while it suppresses glycolysis, cytoprotective autophagy and EMT. Low expression of miR-218 can result in development of chemoresistance and radio-resistance in tumor cells and direct targeting of miR-218 as a key player is promising in cancer therapy. LncRNAs and circRNAs are nonprotein coding transcripts that can regulate miR-218 expression in human cancers. Moreover, low expression level of miR-218 can be observed in human cancers such as brain, gastrointestinal and urological cancers that mediate poor prognosis and low survival rate.

The SLIT/ROBO Pathway in Liver Fibrosis and Cancer

Liver fibrosis is a common outcome of most chronic liver insults/injuries that can develop into an irreversible process of cirrhosis and, eventually, liver cancer. In recent years, there has been significant progress in basic and clinical research on liver cancer, leading to the identification of various signaling pathways involved in tumorigenesis and disease progression. Slit glycoprotein (SLIT)1, SLIT2, and SLIT3 are secreted members of a protein family that accelerate positional interactions between cells and their environment during development. These proteins signal through Roundabout receptor (ROBO) receptors (ROBO1, ROBO2, ROBO3, and ROBO4) to achieve their cellular effects. The SLIT and ROBO signaling pathway acts as a neural targeting factor regulating axon guidance, neuronal migration, and axonal remnants in the nervous system. Recent findings suggest that various tumor cells differ in SLIT/ROBO signaling levels and show varying degrees of expression patterns during tumor angiogenesis, cell invasion, metastasis, and infiltration. Emerging roles of the SLIT and ROBO axon-guidance molecules have been discovered in liver fibrosis and cancer development. Herein, we examined the expression patterns of SLIT and ROBO proteins in normal adult livers and two types of liver cancers: hepatocellular carcinoma and cholangiocarcinoma. This review also summarizes the potential therapeutics of this pathway for anti-fibrosis and anti-cancer drug development.

Hsa_circRNA_001859 regulates pancreatic cancer progression and epithelial-mesenchymal transition through the miR-21-5p/SLC38A2 pathway

OBJECTIVE: This study attempts to investigate whether hsa_circRNA_001859 (circ_001859) could regulate the proliferation and invasion of pancreatic cancer through the miR-21-5p/SLC38A2 pathway. METHODS: GSE79634 microarray was analyzed with R package. The expression of circ_001859 in pancreatic cancer tissues and cells was verified by qRT-PCR. After the overexpression of circ_001859, cell proliferation, cell migration and invasion were verified by colony formation and transwell assay. The targeting relationship between miR-21-5p and circ_001859 was predicted by TargetScan and was verified by dual luciferase reporter assay, RNA pull down and qRT-PCR. The effect of miR-21-5p on cell proliferation, migration and invasion were investigated by colony formation and transwell assay respectively. Similarly, the targeting relationship between miR-21-5p and SLC38A2 was predicted by TargetScan and was verified by dual luciferase reporter assay, western blot and qRT-PCR. The effect of SLC38A2 on cell proliferation was investigated by colony formation. RESULTS: Circ_001859 was lowly expressed in pancreatic cancer tissues and cells. In vitro assays showed that overexpression of circ_001859 could inhibit the proliferation, migration and invasion of pancreatic cancer. In addition, this effect was also confirmed in xenograft transplantation model. Circ_001859 could be bind to miR-21-5p and sponge its expression in pancreatic cancer cells. Overexpression of miR-21-5p enhanced the proliferation, migration and invasion ability of pancreatic cancer cells, while the inhibition of miR-21-5p expression suppressed these abilities. Moreover, miR-21-5p directly targeted at SLC38A2 and inhibited SLC38A2 expression levels while circ_001859 up-regulated SLC38A2 levels. SLC38A2 expression knockdown enhanced cell proliferation but SLC38A2 overexpression resulted in decreased proliferation, and effects of SLC38A2 could be rescued by miR-21-5p and circ_001859. In addition, both QRT-PCR and immunofluorescence confirmed that circ_001859 could regulate tumor epithelial-mesenchymal transition (EMT) through the miR-21-5p/SLC38A2 pathway. CONCLUSIONS: This study suggests that circ_001859 may inhibit the proliferation, invasion and EMT of pancreatic cancer through the miR-21-5p/SLC38A2 pathway.

Chimeric Antigen Receptor-Natural Killer Cells: A New Breakthrough in the Treatment of Solid Tumours

Natural killer (NK) cells can quickly and directly eradicate tumour cells without recognising tumour-specific antigens. NK cells also participate in immune surveillance, which arouses great interest in the development of novel cancer therapies. The chimeric antigen receptor (CAR) family is composed of receptor proteins that give immune cells extra capabilities to target specific antigen proteins or enhance their killing effects. CAR-T cell therapy has achieved initial success in haematological tumours, but is prone to adverse reactions, especially with cytokine release syndrome in clinical applications. Currently, CAR-NK cell therapy has been shown to successfully kill haematological tumour cells with allogeneic NK cells in clinical trials without adverse reactions, proving its potential to become an off-the-shelf product with broad clinical application prospects. Meanwhile, clinical trials of CAR-NK cells for solid tumours are currently underway. Here we will focus on the latest advances in CAR-NK cells, including preclinical and clinical trials in solid tumours, the advantages and challenges of CAR-NK cell therapy and new strategies to improve the safety and efficacy of CAR-NK cell therapy.

Exosomes mediated fibrogenesis in dilated cardiomyopathy through a MicroRNA pathway

Cardiac fibrosis is a hallmark in late-stage familial dilated cardiomyopathy (DCM) patients, although the underlying mechanism remains elusive. Cardiac exosomes (Exos) have been reported relating to fibrosis in ischemic cardiomyopathy. Thus, we investigated whether Exos secreted from the familial DCM cardiomyocytes could promote fibrogenesis. Using human iPSCs differentiated cardiomyocytes we isolated Exos of angiotensin II stimulation conditioned media from either DCM or control (CTL) cardiomyocytes. Of interest, cultured cardiac fibroblasts had increased fibrogenesis following exposure to DCM-Exos rather than CTL-Exos. Meanwhile, injecting DCM-Exos into mouse hearts enhanced cardiac fibrosis and impaired cardiac function. Mechanistically, we identified the upregulation of miRNA-218-5p in the DCM-Exos as a critical contributor to fibrogenesis. MiRNA-218-5p activated TGF-β signaling via suppression of TNFAIP3, a master inflammation inhibitor. In conclusion, our results illustrate a profibrotic effect of cardiomyocytes-derived Exos that highlights an additional pathogenesis pathway for cardiac fibrosis in DCM.

Tumor-Derived Exosomal miR-29b Reduces Angiogenesis in Pancreatic Cancer by Silencing ROBO1 and SRGAP2

Background. Exosomal miR-29b reportedly plays a role during cancer metastasis. However, its exact function and underlying mechanism during pancreatic cancer (PC) have not been investigated. Methods. Exosomes from PC cells were prepared and identified. Transmission electron microscopy (TEM) and confocal microscopy were used to examine structural characteristics of the exosomes and verify their internalization by human umbilical vein endothelial cells (HUVECs). The tube formation and migration abilities of HUVECs were detected. VEGF content was assessed by ELISA. GW4869 was used to suppress exosome release. Luciferase reporter assays were performed to verify the predicted interaction of miR-29b with ROBO1 and SRGAP2 mRNA. Results. Exosomal miRNA-29b was differentially expressed in the conditioned medium of PC cells. Exosomes from PC cells were verified by TEM and western blotting. Treatment with the exosomal inhibitor (GW4869) prevented an increase in miR-29b expression and recused the reduced VEGF expression and tube formation and migration abilities of HUVECs cocultured with BxPC3 and AsPC-1 cells that overexpressed miR-29b. Furthermore, the downregulation of ROBO1 and SRGAP2 in cocultured HUVECs was also reduced after additional treatment with GW4869. After incubation with miR-29b exosomes, HUVECs had lower VEGF concentrations and reduced migration and tube formation rates; however, those effects were eliminated by subsequent transfection with the miR-29b inhibitor. Luciferase reporter assays verified the interaction of miR-29b with ROBO1 and SRGAP2. That interaction was also supported by rescue assays showing that overexpression of ROBO1 and SRGAP2 also reduced the antiangiogenic effect of exosomal miR-29b in HUVECs. Conclusion. Exosomal miR-29b originating from PC cells protected HUVECs from PC cell-induced angiogenesis by attenuating ROBO1 and SRGAP2 expression. Our findings suggest a strategy for treating PC.

Epithelial to Mesenchymal Transition: Key Regulator of Pancreatic Ductal Adenocarcinoma Progression and Chemoresistance

Simple Summary

Pancreatic ductal adenocarcinoma’s (PDAC) dismal prognosis is associated with its aggressive biological behavior and resistance to chemotherapy. Epithelial to mesenchymal transition (EMT) has been recognized as a key driver of PDAC progression and development of drug resistance. EMT is a transient and reversible process leading to transdifferentiation of epithelial cells into a more mesenchymal phenotype. It is regulated by multiple signaling pathways that control the activity of a transcription factors network. Activation of EMT in pre-invasive stages of PDAC has been accused for early dissemination. Furthermore, it contributes to the development of intratumoral heterogeneity and drug resistance. This review summarizes the available data regarding signaling networks regulating EMT and describes the integral role of EMT in different aspects of PDAC pathogenesis.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies, characterized by aggressive biological behavior and a lack of response to currently available chemotherapy. Emerging evidence has identified epithelial to mesenchymal transition (EMT) as a key driver of PDAC progression and a central regulator in the development of drug resistance. EMT is a reversible transdifferentiation process controlled by complex interactions between multiple signaling pathways such as TGFb, Wnt, and Notch, which converge to a network of specific transcription factors. Activation of EMT transcriptional reprogramming converts cancer cells of epithelial differentiation into a more mesenchymal phenotypic state. EMT occurrence in pre-invasive pancreatic lesions has been implicated in early PDAC dissemination. Moreover, cancer cell phenotypic plasticity driven by EMT contributes to intratumoral heterogeneity and drug tolerance and is mechanistically associated with the emergence of cells exhibiting cancer stem cells (CSCs) phenotype. In this review we summarize the available data on the signaling cascades regulating EMT and the molecular isnteractions between pancreatic cancer and stromal cells that activate them. In addition, we provide a link between EMT, tumor progression, and chemoresistance in PDAC.

Non-coding RNAs in pancreatic ductal adenocarcinoma: New approaches for better diagnosis and therapy

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies with a 5-year survival rate less than 8%, which has remained unchanged over the last 50 years. Early detection is particularly difficult due to the lack of disease-specific symptoms and a reliable biomarker. Multimodality treatment including chemotherapy, radiotherapy (used sparingly) and surgery has become the standard of care for patients with PDAC. Carbohydrate antigen 19-9 (CA 19-9) is the most common diagnostic biomarker; however, it is not specific enough especially for asymptomatic patients. Non-coding RNAs are often deregulated in human malignancies and shown to be involved in cancer-related mechanisms such as cell growth, differentiation, and cell death. Several micro, long non-coding and circular RNAs have been reported to date which are involved in PDAC. Aim of this review is to discuss the roles and functions of non-coding RNAs in diagnosis and treatments of PDAC.

CAR-NK Cells in the Treatment of Solid Tumors

CAR-T (chimeric antigen receptor T) cells have emerged as a milestone in the treatment of patients with refractory B-cell neoplasms. However, despite having unprecedented efficacy against hematological malignancies, the treatment is far from flawless. Its greatest drawbacks arise from a challenging and expensive production process, strict patient eligibility criteria and serious toxicity profile. One possible solution, supported by robust research, is the replacement of T lymphocytes with NK cells for CAR expression. NK cells seem to be an attractive vehicle for CAR expression as they can be derived from multiple sources and safely infused regardless of donor-patient matching, which greatly reduces the cost of the treatment. CAR-NK cells are known to be effective against hematological malignancies, and a growing number of preclinical findings indicate that they have activity against non-hematological neoplasms. Here, we present a thorough overview of the current state of knowledge regarding the use of CAR-NK cells in treating various solid tumors.

Pancreatic Cancer and Therapy: Role and Regulation of Cancer Stem Cells

Despite significant improvements in clinical management, pancreatic cancer (PC) remains one of the deadliest cancer types, as it is prone to late detection with extreme metastatic properties. The recent findings that pancreatic cancer stem cells (PaCSCs) contribute to the tumorigenesis, progression, and chemoresistance have offered significant insight into the cancer malignancy and development of precise therapies. However, the heterogeneity of cancer and signaling pathways that regulate PC have posed limitations in the effective targeting of the PaCSCs. In this regard, the role for K-RAS, TP53, Transforming Growth Factor-β, hedgehog, Wnt and Notch and other signaling pathways in PC progression is well documented. In this review, we discuss the role of PaCSCs, the underlying molecular and signaling pathways that help promote pancreatic cancer development and metastasis with a specific focus on the regulation of PaCSCs. We also discuss the therapeutic approaches that target different PaCSCs, intricate mechanisms, and therapeutic opportunities to eliminate heterogeneous PaCSCs populations in pancreatic cancer.

Long non-coding RNA SNHG7 facilitates pancreatic cancer progression by regulating the miR-146b-5p/Robo1 axis

Long non-coding RNA (lncRNA) small nucleolar RNA host gene 7 (SNHG7) plays a crucial role in the progression of pancreatic cancer (PC). SNHG7 is upregulated in PC; therefore, the purpose of the present study was to investigate the role and underlying mechanism of SNHG7 on PC progression. In the present study, the mRNA expression levels of SNHG7, microRNA(miR)-146b-5p and roundabout homolog 1 (Robo1) were measured via reverse transcription-quantitative PCR. Moreover, cell viability and apoptosis were assessed by MTT and flow cytometry assays, respectively. The ability of cells to migrate and invade was evaluated by Transwell assays. In addition, dual-luciferase reporter, RNA immunoprecipitation and RNA pull-down assays were conducted to assess the interaction between miR-146b-5p and SNHG7 or Robo1. The protein expression of Robo1 was measured via western blotting. Furthermore, mouse xenograft models were established to further investigate the effect of SNHG7 on PC progression in vivo. The results indicated that SNHG7 was highly expressed in PC tissues and cells. It was also found that SNHG7 was sponged by miR-146b-5p and that Robo1 was a target of miR-146b-5p. Moreover, it was demonstrated that SNHG7 knockdown inhibited cell proliferation, migration and invasion, as well as tumorigenesis and apoptosis of PC cells in vitro and in vivo by regulating miR-146b-5p. The results also suggested that miR-146b-5p overexpression inhibited the progression of PC cells by modulating Robo1. Furthermore, silencing of SNHG7 downregulated Robo1 expression by sponging miR-146b-5p. Collectively, the present results indicate that SNHG7 promotes PC progression by sponging miR-146b-5p and upregulating Robo1.

CCAT1 promotes triple-negative breast cancer progression by suppressing miR-218/ZFX signaling

Long non-coding RNAs (lncRNAs) regulate cancer development and progression. Here, we investigated the role of the lncRNA CCAT1 in triple-negative breast cancer (TNBC). CCAT1 expression was higher in TNBC cells than normal breast epithelial cells. Additionally, CCAT1 expression was higher in TNBC patient tumor tissue than adjacent normal breast tissue. Silencing CCAT1 inhibited TNBC cell proliferation, migration, and invasion in vitro, and tumor growth and progression in vivo. Bioinformatics analysis revealed that microRNA-218 (miR-218) is a potential target of CCAT1. Silencing CCAT1 resulted in an increase in miR-218 expression and inhibited TNBC cell proliferation, migration, and invasion. Silencing miR-218 reversed the effects of CCAT1 knockdown on cell proliferation, migration, and invasion, suggesting that CCAT1 promotes TNBC progression by downregulating miR-218 expression. We identified the zinc finger protein ZFX as a putative downstream target of miR-218 through bioinformatics analysis. ZFX expression was higher in TNBC than normal breast cell lines and higher in TNBC tumor tissue than adjacent normal breast tissue. Overexpression of ZFX reversed the tumor-suppressive effects of miR-218 on TNBC cell proliferation, migration, and invasion. Our data indicate that CCAT1 promotes TNBC progression by targeting the miR-218/ZFX axis.

Research Progress on Slit/Robo Pathway in Pancreatic Cancer: Emerging and Promising

Pancreatic cancer is a highly malignant digestive system tumor which is the leading cause of cancer-related deaths. The basic and clinical research of pancreatic cancer has made great progress in recent years, and kinds of signaling pathways have been found in the tumorigenesis and progression in pancreatic cancer. The Slit glycoprotein (Slit) and Roundabout receptor (Robo) signaling pathway acts as a neural targeting factor with the axonal remnant, axon guidance, and inhibition of neuronal migration in the nervous system. In recent years, it has been found that the Slit/Robo signaling pathway has different degrees of expression changes in various tumor cells. In different tumor cells, the signaling pathway gene expression is different and regulates tumor angiogenesis, cell invasion, metastasis, and nerve infiltration. Herein, we summarize the mechanisms of the Slit/Robo pathway in the development and progression of pancreatic cancer, in order to have more understanding of the role of Slit/Robo in pancreatic cancer.

MicroRNA in Pancreatic Cancer: From Biology to Therapeutic Potential

Pancreatic cancer is one of the most aggressive malignancies, accounting for more than 45,750 deaths annually in the U.S. alone. The aggressive nature and late diagnosis of pancreatic cancer, coupled with the limitations of existing chemotherapy, present the pressing need for the development of novel therapeutic strategies. Recent reports have demonstrated a critical role of microRNAs (miRNAs) in the initiation, progression, and metastasis of cancer. Furthermore, aberrant expressions of miRNAs have often been associated with the cause and consequence of pancreatic cancer, emphasizing the possible use of miRNAs in the effective management of pancreatic cancer patients. In this review, we provide a brief overview of miRNA biogenesis and its role in fundamental cellular process and miRNA studies in pancreatic cancer patients and animal models. Subsequent sections narrate the role of miRNA in, (i) cell cycle and proliferation; (ii) apoptosis; (iii) invasions and metastasis; and (iv) various cellular signaling pathways. We also describe the role of miRNA's in pancreatic cancer; (i) diagnosis; (ii) prognosis and (iii) therapeutic intervention. Conclusion section describes the gist of review with future directions.

Upregulation of miR-519 enhances radiosensitivity of esophageal squamous cell carcinoma trough targeting PI3K/AKT/mTOR signaling pathway

PURPOSE

MicroRNA-519 (miR-519) has been previously reported to function as a tumor suppressor in several types of malignancies. This study aimed to probe the biological role of miR-519 in esophageal squamous cell carcinoma (ESCC).

METHODS

qRT-PCR was utilized to test the miR-519 expression level in ESCC tissues and cells. Clinical value of miR-519 was investigated by Kaplan-Meier method. Function assays were conducted to determine the role of miR-519 in radioresistance of ESCC cells. The miR-519-regulated pathways were determined by Kyoto Encyclopedia of Genes and Genomes pathway analysis.

RESULTS

Low expression level of miR-519 was closely correlated with the poor prognosis for overall survival of ESCC patients or patients who received radiotherapy. Functional assays indicated that upregulation of miR-519 made ESCC cells more sensitive to γ-ray radiation and facilitated ESCC cell apoptosis triggered by irradiation treatment via regulating DNA response. Ectopic expression of miR-519 decreased the level of p-AKT and p-mTOR, thus inactivating PI3K/AKT/mTOR signaling pathway after irradiation.

CONCLUSION

These observations elucidated that upregulated miR-519 is closely correlated with the radiosensitivity of ESCC cells, which may contribute to finding a new promising target for improving the efficiency of radiotherapy in patients with ESCC.

Downregulation of microRNA-218 is cardioprotective against cardiac fibrosis and cardiac function impairment in myocardial infarction by binding to MITF

OBJECTIVE

This study is intended to figure out the function of microRNA-218 (miR-218) together with microphthalmia-associated transcription factor (MITF) on the cardiac fibrosis and cardiac function impairment in rat models of myocardial infarction (MI).

RESULTS

The rats with MI exhibited cardiac function impairment, cardiac fibrosis, oxidative stress, cardiomyocyte apoptosis, as well as inflammatory injury. Additionally, upregulated miR-218 and downregulated MITF were detected in cardiac tissues of MI rats. MI rats injected with miR-218 inhibitors or overexpressed MITF exhibited elevated MITF expression, improved cardiac function, and diminished pathological damages, infarct size, cardiomyocyte apoptosis, cardiac fibrosis, oxidative stress as well as inflammatory injury in cardiac tissues. Furthermore, downregulated miR-218 and MITF aggravated the conditions than downregulation of miR-218 alone in MI rats.

METHODS

MI models were performed in rats, and then the rats were injected with miR-218 inhibitors and/or MITF overexpression plasmid to elucidate the role of miR-218 and/or MITF on the cardiac function, pathological damage, cardiac fibrosis, angiogenesis, oxidative stress and inflammatory injury of cardiac tissues in MI rats by performing a series of assays.

CONCLUSION

Collectively, we found that the suppression of miR-218 alleviates cardiac fibrosis and cardiac function impairment, and stimulates angiogenesis in MI rats through inhibiting MITF.

miR-1290 inhibits chordoma cell proliferation and invasion by targeting Robo1

BACKGROUND

Chordoma is a low-grade aggressive bone tumor with a high local recurrence. MicroRNAs (miRNAs) have been reported to play crucial roles in the development of chordoma. Our previous study has shown miR-1290 is associated with muscle invasion and the prognosis of chordoma. However, the underlying mechanism of miR-1290 in chordoma remains unclear. In this study, we aimed to explore the function of miR-1290 in the biological behaviors of chordoma.

METHODS

Sixteen sacral chordoma samples and 10 fetal nucleus pulposus specimens were collected for the detection of miR-1290 and Robo1 at the First Affiliated Hospital of Soochow University. Bioinformatic analysis and a luciferase reporter assay was used to verify the interaction between miR-1290 and the target gene robo1 in chordoma. Effects of miR-1290 expression on chordoma cell proliferation and invasion were explored by clone formation and Transwell assay in vitro. The underlying mechanisms of miR-1290 and Robo1 in chordoma cell proliferation and invasion were also explored in the U-CH1 cell line.

RESULTS

In vitro functional analysis, including clone formation, and Transwell assays indicated overexpression of miR-1290 significantly suppressed chordoma cell proliferation and invasion. Bioinformatic analysis revealed Robo1 as a potential target of miR-1290, and luciferase reporter assays demonstrated the association between miR-1290 and the Robo1 gene in U-CH1 cells. Robo1 was further confirmed to be up-regulated in chordoma tissues by immunohistochemistry (IHC), which is negatively correlated with miR-1290 expression in chordoma tissue. Additionally, we found down-regulation of miR-1290 could induce the expression of Robo1 in chordoma cells, while the elevation of miR-1290 expression could inhibit Robo1 expression in chordoma cells.

CONCLUSIONS

miR-1290 inhibits chordoma cell proliferation and invasion by negatively regulating the Robo1 gene.

miR-128 induces pancreas cancer cell apoptosis by targeting MDM4

MicroRNAs (miRNA/miRs) are small, non-coding RNA molecules (19-25 nucleotides in length), which function to regulate gene expression. It has been reported that miR-128 serves an important role in regulating cancer cell growth; increasing evidence has indicated that the expression of miR-128 is decreased in pancreatic cancer (PC) cells. However, the specific mechanisms of miR-128 in regulating PC cell growth are unclear. In the present study, it was confirmed that the expression of miR-128 was significantly decreased within PC tissues compared with adjacent normal tissues via reverse transcription-quantitative polymerase chain reaction analysis. In addition, miR-128 mimics inhibited PC MIA-PaCa2 cell growth by enhancing cell apoptosis in a caspase-dependent manner. Furthermore, the results of the present study demonstrated that double minute 4 (MDM4) may be a direct target for miR-128 via a dual luciferase report assay; miR-128 may inhibit MDM4 expression, and increase p53 and cleaved caspase-3 protein expression levels. In summary, the present study indicated that miR-128 is downregulated in PC, and it may be a promising target for future PC diagnosis and treatment.

SLIT2/ROBO1 axis contributes to the Warburg effect in osteosarcoma through activation of SRC/ERK/c-MYC/PFKFB2 pathway

Cellular metabolic reprogramming is the main characteristic of cancer cells and identification of targets using this metabolic pattern is extremely important to treat cancers, such as osteosarcoma (OS). In this study, SLIT2 and ROBO1 were upregulated in OS, and higher expression of ROBO1 was associated with worse overall survival rate. Furthermore, in vitro and in vivo experiments demonstrated that the SLIT2/ROBO1 axis promotes proliferation, inhibits apoptosis, and contributes to the Warburg effect in OS cells. Mechanistically, the SLIT2/ROBO1 axis exerted cancer-promoting effects on OS via activation of the SRC/ERK/c-MYC/PFKFB2 pathway. Taken together, the findings reveal a previously unappreciated function of SLIT2/ROBO1 signaling in OS, which is intertwined with metabolic alterations that promote cancer progression. Targeting the SLIT2/ROBO1 axis may be a potential therapeutic approach for patients with OS.

Circulating miRNA-21-5p as a diagnostic biomarker for pancreatic cancer: evidence from comprehensive miRNA expression profiling analysis and clinical validation

Pancreatic cancer (PC) is a highly fatal disease worldwide and is often misdiagnosed in its early stages. The exploration of novel non-invasive biomarkers will definitely benefit PC patients. Recently, circulating miRNAs in body fluids are emerging as non-invasive biomarkers for PC diagnosis. In this study, we first conducted comprehensive robust rank aggregation (RRA) analysis based on 21 published miRome profiling studies. We statistically identified and clinically validated a miRNA expression pattern in PC patients. These miRNAs consisted of four up-regulated (hsa-miR-21-5p, hsa-miR-31-5p, hsa-miR-210-3p and hsa-miR-155-5p) and three down-regulated miRNAs (hsa-miR-217, hsa-miR-148a-3p and hsa-miR-375). Among them, hsa-miR-21-5p was one of the most highly expressed miRNAs in the serum of PC patients. Our validation test further suggested a relatively high accuracy of serum hsa-miR-21-5p levels in the diagnosis of PC, with a sensitivity of 0.77 and a specificity of 0.80. Finally, a diagnostic meta-analysis based on 9 studies also revealed favorable sensitivity and specificity of circulating hsa-miR-21-5p for the diagnosis of PC (pooled sensitivity and specificity were 0.76 and 0.74, respectively), which was consistent with our findings. Taken together, as one of the most aberrantly expressed miRNAs in PC, circulating hsa-miR-21-5p might be a promising serum biomarker in patients with PC.

Prognostic significance of low microRNA-218 expression in patients with different types of cancer: Evidence from published studies

BACKGROUND

Mounting evidence showed that microRNAs may be useful as prognostic biomarkers of cancer. Therefore, we summarize the predictive role of microRNA-218 (miR-218) for survival in patients with various cancers.

METHODS

We performed a systematic literature review and assessed the quality of included studies based on Meta-analysis of Observational Studies in Epidemiology group (MOOSE). Hazard ratios (HRs) with corresponding 95% confidence intervals (CIs) were calculated to assess the correlation between miR-218 expression and prognosis of different cancers.

RESULTS

We identified 10 studies for pooled analyses. For overall survival, a lower expression levels of miR-218 significantly predicted poorer survival, with the pooled HR of 2.61 (95% CI: 2.11-3.22, P < 0.001). For disease-free survival/progressive-free survival/recurrence-free survival (DFS/PFS/RFS), a lower expression level of miR-218 significantly predicted worse DFS/PFS/RFS in various carcinomas, with the pooled HR of 2.73 (95% CI: 2.08-3.58, P < 0.001). Similarly, subgroup analysis by detection method, ethnicity and cancer subtype analysis suggested that lower expression of miR-218 correlated with.

CONCLUSION

Our data demonstrated that lower miR-218 expression is significantly associated with poorer overall survival (OS) and DFS/PFS/RFS and may be a novel prognostic biomarker in some cancer types.

Developments in miRNA gene signaling pathways in pancreatic cancer

Pancreatic cancer is a devastating malignancy that ranks as the fourth leading cause of cancer-related deaths worldwide. Dismal prognosis is mainly attributable to limited knowledge of the molecular pathogenesis of the disease. miRNAs have been found to be deregulated in pancreatic cancer, affecting several steps of initiation and aggressiveness of the disease by regulating important signaling pathways, such as the KRAS and Notch pathways. Moreover, the effect of miRNAs on regulating cell cycle events and expression of transcription factors has gained a lot of attention. Recent studies have highlighted the application of miRNAs as biomarkers and therapeutic tools. The current review focuses on latest advances with respect to the roles of miRNAs in pancreatic ductal adenocarcinoma associated signaling pathways and miRNA-based therapeutics.

Expression of microRNA-218 and its clinicopathological and prognostic significance in human glioma cases

BACKGROUND

MicroRNAs are a class of noncoding RNAs which regulate multiple cellular processes during tumor development. The purpose of this report is to investigate the clinicopathological and prognostic significance of miR-218 in human gliomas.

MATERIALS AND METHODS

Quantitative RT-PCR (qRT-PCR) was conducted to detect the expression of miR-218 in primary normal human astrocytes, three glioma cell lines and 98 paired glioma and adjacent normal brain tissues.Associations of miR-218 with clinicopathological variables of glioma patients were statistically analyzed. Finally, a survival analysis was performed using the Kaplan-Meier method and Cox's proportional hazards model.

RESULTS

The expression level of miR-218 in primary normal human astrocytes was significantly higher than that in glioma cell lines (p<0.01). Also, the expression level of miR-218 in glioma tissues was significantly downregulated in comparison with that in the adjacent normal brain tissues (p<0.001). Statistical analyses demonstrated that low miR-218 expression was closely associated with advanced WHO grade (p=0.002) and low Karnofsky performance score (p=0.010) of glioma patients. Kaplan-Meier analysis with the log-rank test showed that patients with low-miR-218 expression had poorer disease-free survival and overall survival (p=0.0045 and 0.0124, respectively). Multivariate analysis revealed that miR-218 expression was independently associated with the disease-free survival (p=0.009) and overall survival (p=0.004) of glioma patients.

CONCLUSIONS

Our results indicate that miR-218 is downregulated in gliomas and that its status might be a potential valuable biomarker for glioma patients.

MicroRNA-183-5p promotes the proliferation, invasion and metastasis of human pancreatic adenocarcinoma cells

The aim of the current study was to investigate the potential role of microRNA-183-5p (miR-183-5p) in the proliferation, invasion and metastasis of pancreatic cancer, and to identify promising target genes of oncogenic miR-183-5p. Western blotting and quantitative polymerase chain reaction (qPCR) were used to investigate whether these oncogenic microRNAs may be useful as biomarkers in pancreatic carcinoma (PaCa). Potential target genes were verified using miRDB, PicTar and TargetSCAN, and qPCR was used to detect the expression of miR-183 and suppressor of cytokine signaling 6 (SOCS-6; a potential target of miR-183) in PANC-1 PaCa cells and in the HPDE6-C7 pancreatic ductal cell line for comparison. The function of miR-183 in cell proliferation, wound healing, invasion and migration was also investigated using a miR-183 inhibitor. Western blot analysis was used to confirm SOCS-6 as a tumor suppressor and qPCR was used to detect and confirm that this potential target gene is directly regulated by miR-183. The results indicated that the expression of miR-183 in PANC-1 cells was upregulated compared with that in HPDE6-C7 cells, whilst the expression of SOCS-6 was downregulated. SOCS-6 expression was also significantly lower in PaCa tissues compared with that in matched normal pancreatic tissues from PaCa patients. Furthermore, expression of miR-183 was inversely correlated with that of SOCS-6. miR-183 knockdown decreased cell growth and motility in pancreatic cancer cells and significantly increased the expression of SOCS-6. These data suggest that oncogenic miR-183 may be useful as a pancreatic cancer biomarker. In addition, inhibition of miR-183 expression may be beneficial as PaCa treatment. SOCS-6 is a potential target gene of miR-183.

MicroRNAs as biomarkers and prospective therapeutic targets in colon and pancreatic cancers

Colon and pancreatic cancers have high mortality rates due to early metastasis prior to the onset of symptoms. Screening tests for colorectal cancer are invasive and expensive. No effective screening is available for pancreatic cancer. Identification of biomarkers for early detection in both of these cancers is being extensively researched. MicroRNAs (miRNA) are small non-coding molecule biomarkers that regulate cancers. Measurement of miRNAs in pancreatic fluid or blood could be a preferred non-invasive screening method. The regulation of colon and pancreatic cancers by miRNA is complex. miRNA play a central role in inflammation, invasiveness, and tumor progression in these two cancers, as well as regulation of the NF-κB pathway. miRNA's evolving role in screening is also reviewed.

MiR-302c-3p suppresses invasion and proliferation of glioma cells via down-regulating metadherin (MTDH) expression

Glioma is the most common malignant brain tumors with poor prognosis. The molecular events involved in the development and progression of glioma remain unclear. In this study, the expression levels of miR-302c-3p were examined in glioma tissues by qRT-PCR. The in vitro and in vivo functional effects of miR-302c-3p were examined further. Luciferase reporter assays were conducted to confirm the targeting associations. Results showed that the expression level of miR-302c-3p in glioma tissues was significantly lower than those in normal brain tissues (P < 0.001). The decreased expression of mi-302c-3p in glioma was positively associated with WHO grade (P < 0.001). Up-regulation of MTDH was also detected in glioma tumors compared with normal brain tissues (P = 0.0027) and is inversely correlated with miR-302c-3p expression (P = 0.003, R(2) = 0.4065). MTDH mRNA is a direct target of miR-302c-3p, whose ectopic expression decreases MTDH expression through binding to its 3'-untranslated region. Overexpression of miR-302c-3p results in a dramatic inhibition of glioma cells proliferation and invasion in vitro and in vivo. These data suggest that miR-302c-3p play a pivotal role in the progression of glioma by targeting MTDH and is a potential inhibitor in glioma treatment.