MicroRNAs in the Diagnosis and Treatment of Cancer

Unravelling the Mysteries of the Sonic Hedgehog Pathway in Cancer Stem Cells: Activity, Crosstalk and Regulation

The Sonic Hedgehog (Shh) signalling pathway plays a critical role in normal development and tissue homeostasis, guiding cell differentiation, proliferation, and survival. Aberrant activation of this pathway, however, has been implicated in the pathogenesis of various cancers, largely due to its role in regulating cancer stem cells (CSCs). CSCs are a subpopulation of cancer cells with the ability to self-renew, differentiate, and initiate tumour growth, contributing significantly to tumorigenesis, recurrence, and resistance to therapy. This review focuses on the intricate activity of the Shh pathway within the context of CSCs, detailing the molecular mechanisms through which Shh signalling influences CSC properties, including self-renewal, differentiation, and survival. It further explores the regulatory crosstalk between the Shh pathway and other signalling pathways in CSCs, highlighting the complexity of this regulatory network. Here, we delve into the upstream regulators and downstream effectors that modulate Shh pathway activity in CSCs. This review aims to cast a specific focus on the role of the Shh pathway in CSCs, provide a detailed exploration of molecular mechanisms and regulatory crosstalk, and discuss current and developing inhibitors. By summarising key findings and insights gained, we wish to emphasise the importance of further elucidating the interplay between the Shh pathway and CSCs to develop more effective cancer therapies.

Stimulators of immunogenic cell death for cancer therapy: focusing on natural compounds

A growing body of evidence indicates that the anticancer effect of the immune system can be activated by the immunogenic modulation of dying cancer cells. Cancer cell death, as a result of the activation of an immunomodulatory response, is called immunogenic cell death (ICD). This regulated cell death occurs because of increased immunogenicity of cancer cells undergoing ICD. ICD plays a crucial role in stimulating immune system activity in cancer therapy. ICD can therefore be an innovative route to improve anticancer immune responses associated with releasing damage-associated molecular patterns (DAMPs). Several conventional and chemotherapeutics, as well as preclinically investigated compounds from natural sources, possess immunostimulatory properties by ICD induction. Natural compounds have gained much interest in cancer therapy owing to their low toxicity, low cost, and inhibiting cancer cells by interfering with different mechanisms, which are critical in cancer progression. Therefore, identifying natural compounds with ICD-inducing potency presents agents with promising potential in cancer immunotherapy. Naturally derived compounds are believed to act as immunoadjuvants because they elicit cancer stress responses and DAMPs. Acute exposure to DAMP molecules can activate antigen-presenting cells (APCs), such as dendritic cells (DCs), which leads to downstream events by cytotoxic T lymphocytes (CTLs) and natural killer cells (NKs). Natural compounds as inducers of ICD may be an interesting approach to ICD induction; however, parameters that determine whether a compound can be used as an ICD inducer should be elucidated. Here, we aimed to discuss the impact of multiple ICD inducers, mainly focusing on natural agents, including plant-derived, marine molecules, and bacterial-based compounds, on the release of DAMP molecules and the activation of the corresponding signaling cascades triggering immune responses. In addition, the potential of synthetic agents for triggering ICD is also discussed.

Metabolic Pathways in Breast Cancer Reprograming: An Insight to Non-Coding RNAs

Cancer cells reprogram their metabolisms to achieve high energetic requirements and produce precursors that facilitate uncontrolled cell proliferation. Metabolic reprograming involves not only the dysregulation in glucose-metabolizing regulatory enzymes, but also the enzymes engaging in the lipid and amino acid metabolisms. Nevertheless, the underlying regulatory mechanisms of reprograming are not fully understood. Non-coding RNAs (ncRNAs) as functional RNA molecules cannot translate into proteins, but they do play a regulatory role in gene expression. Moreover, ncRNAs have been demonstrated to be implicated in the metabolic modulations in breast cancer (BC) by regulating the metabolic-related enzymes. Here, we will focus on the regulatory involvement of ncRNAs (microRNA, circular RNA and long ncRNA) in BC metabolism, including glucose, lipid and glutamine metabolism. Investigation of this aspect may not only alter the approaches of BC diagnosis and prognosis, but may also open a new avenue in using ncRNA-based therapeutics for BC treatment by targeting different metabolic pathways.

MiR-495 Inhibits Cisplatin Resistance and Angiogenesis in Esophageal Cancer by Targeting ATP7A

Background: Cancer resistance to chemotherapy is closely associated with changes in transporter systems. In this study, we investigated the possible regulation of 1 copper ion transporter (ATP7A; ATPase copper transporting alpha) by microRNA miR-495 and its implications in cisplatin resistance and angiogenesis in esophageal cancer. Methods: MiR-495 and ATP7A mRNA expression in clinical tissue samples and 2 cancer cell lines (Eca-109 and TE1) were detected by quantitative real-time polymerase chain reaction. The levels of miR-495 and ATP7A expression in Eca-109 and TE1 cells were increased by transfection with miR-495 mimics and ATP7A-overexpression vectors. Cell proliferation, apoptosis, and angiogenesis were assessed by CCK-8, flow cytometry, and tube formation assays, respectively. The levels of TNF-α and VEGF in cell culture supernatants were detected by enzyme linked immunosorbent assay, and in situ expression of NLRP3 was measured by immunofluorescence. The binding of miR-495 to ATP7A sequences was verified by dual luciferase reporter assays. Results:ATP7A expression was significantly increased, while miR-495 expression was decreased in the cancer tissues of esophageal cancer patients. MiR-495 mimics decreased the proliferation and promoted the apoptosis of cisplatin-resistant Eca-109 and TE1 cells. Furthermore, tube formation by human umbilical vein endothelial cells, TNF-α and VEGF secretion, and the levels of MRP1, ABCG1, ABCA1, and NLRP3 expression in cisplatin-resistant Eca-109 and TE1 cells were all reduced by miR-495 mimics. MiR-495 was shown to directly bind to ATP7A gene sequences to repress ATP7A expression in Eca-109 and TE1 cells. ATP7A overexpression substantially abrogated the changes in proliferation, apoptosis, angiogenesis, and above-mentioned gene expression in cisplatin-resistant Eca-109 and TE1 cells. Conclusions: MiR-495 suppressed cisplatin resistance and angiogenesis in esophageal cancer cells by targeting ATP7A gene expression.

Estrogen promotes lncRNA H19 expression to regulate osteogenic differentiation of BMSCs and reduce osteoporosis via miR-532-3p/SIRT1 axis

Osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) plays an essential role in bone formation. Its imbalance can lead to osteoporosis. Estrogen and long noncoding RNAs (lncRNAs) have been confirmed to participate in osteogenesis. However, the underlying mechanism remains unclear. The purpose of our study was to explore the function of lncRNA H19 in estrogen-induced osteogenic differentiation of BMSCs. The present research demonstrated that the expression levels of lncRNA H19 and SIRT1 were markedly downregulated in postmenopausal osteoporosis (PMOP), while miR-532-3p expression was obviously increased. Moreover, estrogen induced the osteogenic differentiation of BMSCs by upregulating lncRNA H19. Furthermore, our integrated experiments showed that lncRNA H19 caused a decrease in the expression of miR-532-3p, which was verified to target SIRT1 directly. Additionally, estrogen alleviated osteoporosis in OVX rats through lncRNA H19-mediated miR-532-3p/SIRT1 axis. Our findings imply that lncRNA H19 mediates estrogen-regulated osteogenic differentiation in BMSCs via miR-532-3p/SIRT1 signalling and may become a novel target for alleviating PMOP.

Improved understanding of gastrointestinal stromal tumors biology as a step for developing new diagnostic and therapeutic schemes

A gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the human gastrointestinal tract, with an estimated incidence of 10-15 per 1 million per year. While preparing holistic care for patients with GIST diagnosis, scientists might face several difficulties - insufficient risk stratification, acquired or secondary resistance to imatinib, or the need for an exceptional therapy method associated with wild-type tumors. This review summarizes recent advances associated with GIST biology that might enhance diagnostic and therapeutic strategies. New molecules might be incorporated into risk stratification schemes due to their proven association with outcomes; however, further research is required. Therapies based on the significant role of angiogenesis, immunology, and neural origin in the GIST biology could become a valuable enhancement of currently implemented treatment schemes. Generating miRNA networks that would predict miRNA regulatory functions is a promising approach that might help in better selection of potential biomarkers and therapeutical targets in cancer, including GISTs.

miR-338-5p inhibits cell growth and migration via inhibition of the METTL3/m6A/c-Myc pathway in lung cancer

Lung cancer is a common type of cancer that causes a very large public health burden worldwide. Achieving a better understanding of the molecular mechanism underlying the progression of lung cancer is of benefit for the diagnosis, prognosis, and treatment of lung cancer. Here, we first identified dramatically decreased expression of miR-338-5p in lung cancer tissues and cells using quantitative polymerase chain reaction (qPCR) analysis. We then revealed that miR-338-5p inhibited the cell growth and migration of lung cancer cells using cell counting kit 8 (CCK8), EdU, and Transwell analysis. Furthermore, we demonstrated that miR-338-5p inhibited METTL3 expression by qPCR, western blot analysis, and luciferase reporter assay, while upregulation of METTL3 alleviated the role of miR-338-5p in lung cancer cells. We also showed that METTL3 promoted c-Myc expression by increasing the m6A modification of c-Myc, and overexpression of c-Myc restored the inhibition of cell growth and migration of lung cancer cells induced by METTL3 silencing. Ultimately, this research illustrated that modification of the miR-338-5p/METTL3/c-Myc pathway affected cellular progression in lung cancer cells. Collectively, our study revealed the underlying mechanism of miR-338-5p in lung cancer, providing a novel regulatory pathway in lung cancer. There is potential for this pathway to serve as a diagnostic, prognostic, and therapeutic biomarker for lung cancer.

MicroRNA-365 promotes apoptosis in human melanoma cell A375 treated with hydatid cyst fluid of Echinococcus granulosus sensu stricto

Hydatid cyst fluid (HCF)-based therapeutics has experimentally targeted approaches for treating human cancer cell lines. MicroRNA-365 (miR-365) has been reported to be an important tumor suppressor miRNA in cancers. However, it remains unknown, how miR-365 plays a pivotal role in inducing apoptosis in HCF-treated cancer cells in vitro. The fertile/infertile HCF was aspirated from liver of infected sheep and in terms of molecular taxonomy was identified as G1 genotype of Echinococcus granulosus sensu stricto. A375 human melanoma cancer cells were cultured into two groups: fertile and infertile HCF-treated A375 cells. To assess the cytotoxicity of various concentrations of HCF on melanoma cells, cell viability was determined by using MTT assay. The IC50 value of HCF on A375 cells was determined 85 μg/mL. Caspase-3 enzymatic activity was evaluated by fluorometric assay in the HCF-treated melanoma cells. In addition, the mRNA expression of Bax, Bcl-2, Caspase-9 and miR-365 were determined by qRT-PCR. Findings of MTT assay showed that concentrations 85 μg/mL to 100 μg/mL of fertile HCF have the highest mortality (50%-52%) on A375 cells during 24 h. The fold change of Bax/Bcl-2 ratio, Caspase-9, miR-365 and Caspase-3 activity was higher in the fertile HCF-treated melanoma cells compared to infertile fluid treated A375 cells and human normal epithelial cell (as control cell). In conclusion, we over-expressed the miR-365 in melanoma A375 cells, via treatment of fertile HCF. Our findings suggested that inducing high expression of miR-365 might be a negative regulator of melanoma growth through activation of pro-apoptotic Bax, Caspase-9 and Caspase-3 that are essential to intrinsic apoptotic pathway. These findings provide new insights into the use of Echinococcus HCF-derived metabolites in the design of drug therapies and in vivo tumor cell vaccine to combat melanoma progression.

HMGA2 as a Critical Regulator in Cancer Development

The high mobility group protein 2 (HMGA2) regulates gene expression by binding to AT-rich regions of DNA. Akin to other DNA architectural proteins, HMGA2 is highly expressed in embryonic stem cells during embryogenesis, while its expression is more limited at later stages of development and in adulthood. Importantly, HMGA2 is re-expressed in nearly all human malignancies, where it promotes tumorigenesis by multiple mechanisms. HMGA2 increases cancer cell proliferation by promoting cell cycle entry and inhibition of apoptosis. In addition, HMGA2 influences different DNA repair mechanisms and promotes epithelial-to-mesenchymal transition by activating signaling via the MAPK/ERK, TGFβ/Smad, PI3K/AKT/mTOR, NFkB, and STAT3 pathways. Moreover, HMGA2 supports a cancer stem cell phenotype and renders cancer cells resistant to chemotherapeutic agents. In this review, we discuss these oncogenic roles of HMGA2 in different types of cancers and propose that HMGA2 may be used for cancer diagnostic, prognostic, and therapeutic purposes.

Cross-talk between oxidative stress signaling and microRNA regulatory systems in carcinogenesis: Focused on gastrointestinal cancers

Molecular mechanisms underlying development and progression of gastrointestinal (GI) cancers are mediated by both oxidative stress (OS) and microRNAs (miRNAs) involvement. Notably, OS signaling may regulate the expression of miRNAs, and miRNAs function as imperative players in OS-initiated tumors. Given the defined biological roles of both OS systems and miRNAs in GI carcinogenesis, a possible interplay between these two key cellular networks is considered. A growing body of evidence has indicated a reciprocal connection between OS signaling pathways and miRNA regulatory machines in GI cancer development and progression. Illumination of the molecular cross-talking between miRNAs and the OS would improve our pathophysiological insight into carcinogens. Also, understanding the molecular mechanisms in which these systems are reciprocally regulated may imply in future medical practice mainly GI cancer therapy. Nowadays, therapeutic strategies focusing on miRNA and OS in GI cancer treatment are increasingly delineated. Since the use of antioxidants is limited owing to the contrasting consequences of OS signaling in cancer, the discovery of OS-responsive miRNAs may provide a potential new strategy to overcome OS-mediated GI carcinogenesis. Given the possible interaction between OS and miRNAs in GI cancers, this review aimed to elucidate the existing evidence on the interaction between OS and miRNA regulatory machinery and its role in GI carcinogenesis. In this regard, we will illustrate the function of miRNAs which target OS systems during homeostasis and tumorigenesis. We also discuss the biological cross-talk between OS systems and miRNAs and corresponding cell signaling pathways.

Gene expression of thrombomodulin, TNF-α and NF-KB in coronary artery disease patients of Pakistan

Thrombomodulin (THBD) is an endothelial surface glycoprotein receptor, having a pivotal role in maintaining laminar blood flow. It functions to protect endothelial integrity by exhibiting anti-coagulation and anti-inflammatory properties thereby playing a key role in cardiovascular disease (CVD) pathology. Cholesterol lowering drugs have shown to alter the anti-inflammatory effects of cytokines. Understanding the molecular aspects of THBD gene and its relation to inflammatory cytokines is important to identify new prognostic and therapeutic targets for the CVD treatments. The present study was conducted to measure the expression of THBD, TNF-α and NF-kB genes in coronary artery disease patients (CAD) in Pakistani population. Lipid profile and BMI was compared both on fifty CAD patients and fifty healthy individuals. Expression analysis for THBD, TNF-α and NF-kB was carried out using real time PCR. The effect of lipid lowering drugs on cardiometabolic risk variables especially gene expression was analyzed. Our results indicated that the difference in BMI was marginal; however LDL-cholesterol and triglycerides levels in CAD patients were significantly higher than healthy individuals. THBD gene was significantly up-regulated whereas TNF-α and NF-kB were significantly down regulated in CAD individuals. Further exploration revealed that these variations were accounted to the use of statins by the patients. The use of statins by CAD patients up-regulated the mRNA expression of THBD by down-regulation of inflammatory mediators. The enhanced expression of endothelial THBD in response to cholesterol lowering drugs establishes a novel pleiotropic target that can be of clinical significance in thromboembolic and inflammatory disorders.

Secreted breast tumor interstitial fluid microRNAs and their target genes are associated with triple-negative breast cancer, tumor grade, and immune infiltration

Background

Studies on tumor-secreted microRNAs point to a functional role of these in cellular communication and reprogramming of the tumor microenvironment. Uptake of tumor-secreted microRNAs by neighboring cells may result in the silencing of mRNA targets and, in turn, modulation of the transcriptome. Studying miRNAs externalized from tumors could improve cancer patient diagnosis and disease monitoring and help to pinpoint which miRNA-gene interactions are central for tumor properties such as invasiveness and metastasis.

Methods

Using a bioinformatics approach, we analyzed the profiles of secreted tumor and normal interstitial fluid (IF) microRNAs, from women with breast cancer (BC). We carried out differential abundance analysis (DAA), to obtain miRNAs, which were enriched or depleted in IFs, from patients with different clinical traits. Subsequently, miRNA family enrichment analysis was performed to assess whether any families were over-represented in the specific sets. We identified dysregulated genes in tumor tissues from the same cohort of patients and constructed weighted gene co-expression networks, to extract sets of co-expressed genes and co-abundant miRNAs. Lastly, we integrated miRNAs and mRNAs to obtain interaction networks and supported our findings using prediction tools and cancer gene databases.

Results

Network analysis showed co-expressed genes and miRNA regulators, associated with tumor lymphocyte infiltration. All of the genes were involved in immune system processes, and many had previously been associated with cancer immunity. A subset of these, BTLA, CXCL13, IL7R, LAMP3, and LTB, was linked to the presence of tertiary lymphoid structures and high endothelial venules within tumors. Co-abundant tumor interstitial fluid miRNAs within this network, including miR-146a and miR-494, were annotated as negative regulators of immune-stimulatory responses. One co-expression network encompassed differences between BC subtypes. Genes differentially co-expressed between luminal B and triple-negative breast cancer (TNBC) were connected with sphingolipid metabolism and predicted to be co-regulated by miR-23a. Co-expressed genes and TIF miRNAs associated with tumor grade were BTRC, CHST1, miR-10a/b, miR-107, miR-301a, and miR-454.

Conclusion

Integration of IF miRNAs and mRNAs unveiled networks associated with patient clinicopathological traits, and underlined molecular mechanisms, specific to BC sub-groups. Our results highlight the benefits of an integrative approach to biomarker discovery, placing secreted miRNAs within a biological context.

Restoration of miR-330 expression suppresses lung cancer cell viability, proliferation, and migration

Lung cancer is one of the most common cancers and its incidence is rising around the world. Various studies suggest that miR-330 acts as a tumor-suppressor microRNA (miRNA) in different types of cancers, but precisely how has remained unclear. In this study, we investigate miR-330 expression in lung cancer patient samples, as well as in vitro, by studying how normalization of miR-330 expression affects lung cancer cellular phenotypes such as viability, apoptosis, proliferation, and migration. We establish that low miR-330 expression predicts poor lung cancer prognosis. Stable restoration of reduced miR-330 expression in lung cancer cells reduces cell viability, increases the fraction of apoptotic cells, causes G2/M cell cycle arrest, and inhibits cell migration. These findings are substantiated by increased mRNA and protein expression of markers for apoptosis via the intrinsic pathway, such as caspase 9, and decreased mRNA and protein expression of markers for cell migration, such as vimentin, C-X-C chemokine receptor type 4, and matrix metalloproteinase 9. We showed that reduced miR-330 expression predicts poor lung cancer survival and that stable restoration of miR-330 expression in lung cancer cells has a broad range of tumor-suppressive effects. This indicates that miR-330 is a promising candidate for miRNA replacement therapy for lung cancer patients.

Long non-coding RNA LINC00460 predicts poor survival and promotes cell viability in pancreatic cancer

Emerging evidence has demonstrated that long non-coding RNAs (lncRNAs) possess great potential as vital biomarkers and powerful therapeutic targets in various diseases. In the present study, differentially expressed transcripts in pancreatic cancer (PC) were identified, and a competing endogenous RNA (ceRNA) network was constructed using The Cancer Genome Atlas database. An independent cohort consisting of 59 patients with PC was used to validate the clinical value of the identified lncRNA. Cell viability and colony formation assays were used to evaluate the biological functions of the lncRNA in PC cells. The present bioinformatic analysis revealed that LINC00460 was upregulated in PC samples with a prognostic significance. In the ceRNA network, it potentially targeted the microRNA-503/cyclin D1 axis. The results of real-time quantitative PCR confirmed that LINC00460 was significantly upregulated in cancer tissues and was associated with poor survival of patients with PC. The expression levels of LINC00460 were significantly associated with tumor size, but not with age, sex, differentiation, lymph node metastasis, vascular invasion and tumor stage. Through univariate and multivariate analysis, LINC00460 was characterized as an independent prognostic biomarker for PC. Further in vitro experiments demonstrated that suppressing LINC00460 using small interfering RNA inhibited viability and colony formation of PC cells. In summary, LINC00460 may be an independent prognostic biomarker for PC and may serve as an oncogenic lncRNA that promotes PC cell growth. Further in-depth exploration is required to reveal the specific biological mechanism of LINC00460 in PC cells.

miR-330 Regulates Colorectal Cancer Oncogenesis by Targeting BACH1

Purpose: Based on WHO report, colorectal cancer (CRC) is the second cause of death among patients with cancer worldwide. Dysregulation of miRNAs expressions has been demonstrated in different human cancers, especially CRC. Studies have shown that miR-330 could act as both TS-miR and/or oncomiR in different types of cancers. BACH1 is also identified as a transcription factor, which is involved in ontogenesis. In this study, we evaluated the CRC suppression via silencing of BACH1 by small silencer molecule called miR-330.

Methods: Firstly, we analyzed the BACH1, miR-330-3p and miR-330-5p expressions according to the colon adenocarcinoma (COAD) and rectal adenocarcinoma (READ) project established from a patient of the colon and rectal cancer patients in The Cancer Genome Atlas (TCGA) database. The targeting of BACH1 via miR-330 in human CRC cells was evaluated by Vejnar bioinformatics methods, and confirmed by qRT-PCR and western blot analysis. Proliferation was performed by MTT assay. The MMP9, CXCR4, and VEGFR proteins were measured by western blotting.

Results: The analysis of BACH1, miR-330-3p, and miR-330-5p expressions according to the COAD and READ projects showed that BACH1 was overexpressed, but miR-330-3p and miR330-5p were reduced in CRC tumors compared to normal controls. The miR-330 induction prevented proliferation of CRC cell by targeting BACH1 mRNA, which represses MMP9, C-X-C chemokine receptor type 4 (CXCR4), and vascular endothelial growth factor receptor (VEGFR) proteins expressions.

Conclusion: Our results suggested that BACH1 is a potential target for miR-330 in CRC cells. The miR-330 induction inhibits CRC cells proliferation by suppressing BACH1 expression in posttranscriptional level. It was suggested that targeting of BACH1 via miRNA such as miR-330 could be a valid strategy in the field of CRC targeted therapy via modulating the oncogenic signaling pathway.

Current Approaches for Combination Therapy of Cancer: The Role of Immunogenic Cell Death

Cell death resistance is a key feature of tumor cells. One of the main anticancer therapies is increasing the susceptibility of cells to death. Cancer cells have developed a capability of tumor immune escape. Hence, restoring the immunogenicity of cancer cells can be suggested as an effective approach against cancer. Accumulating evidence proposes that several anticancer agents provoke the release of danger-associated molecular patterns (DAMPs) that are determinants of immunogenicity and stimulate immunogenic cell death (ICD). It has been suggested that ICD inducers are two different types according to their various activities. Here, we review the well-characterized DAMPs and focus on the different types of ICD inducers and recent combination therapies that can augment the immunogenicity of cancer cells.

MiR-144: A New Possible Therapeutic Target and Diagnostic/Prognostic Tool in Cancers

MicroRNAs (miRNAs) are small and non-coding RNAs that display aberrant expression in the tissue and plasma of cancer patients when tested in comparison to healthy individuals. In past decades, research data proposed that miRNAs could be diagnostic and prognostic biomarkers in cancer patients. It has been confirmed that miRNAs can act either as oncogenes by silencing tumor inhibitors or as tumor suppressors by targeting oncoproteins. MiR-144s are located in the chromosomal region 17q11.2, which is subject to significant damage in many types of cancers. In this review, we assess the involvement of miR-144s in several cancer types by illustrating the possible target genes that are related to each cancer, and we also briefly describe the clinical applications of miR-144s as a diagnostic and prognostic tool in cancers.

Negative regulation of CDK6 expression by microRNA-126-5p and its influence on the proliferation and invasion of esophageal cancer cells

The present study aimed to investigate the expression of cyclin-dependent kinase 6 (CDK6) and microRNA-126-5p (miR-126-5p) in esophageal cancer tissues and cells, and their effect on esophageal cancer cell proliferation and invasion, and to explore the potential molecular mechanisms. The relative expression levels of CDK6 and miR-126-5p in esophageal cancer tissue, paracancerous tissue, and HEEC and EC109 cells were determined and compared using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A miR-126-5p overexpression vector was constructed and a stable EC109 cell line expressing miR-126-5p was established. The EC109 cell line was transfected with a CDK6 small interfering RNA sequence. The rate of cell proliferation was determined using the WST-8 method, and cell invasion was determined using a Transwell assay. In addition, the relative expression levels of genes were determined using RT-qPCR; the relative expression levels of proteins were determined by western blot analysis; the binding sites of CDK6 and miR-126-5p were analyzed using TargetScan software; and the interaction of CDK6 and miR-126-5p was verified using dual-fluorescence reporter gene expression. Esophageal tissues and EC109 cells expressed higher levels of CDK6 but significantly lower levels of miR-126-5p compared with adjacent tissues and HEEC cells, and their correlation coefficient between esophageal tissues and matched adjacent tissues was -7.526. The overexpression of miR-126-5p and CDK6 knockdown in the EC109 cell line inhibited cell proliferation and invasion compared with the control and NC (negative control) groups. miR-126-5p overexpression reduced the relative expression level of CDK6, and CDK6 knockdown by siRNA increased the expression of miR-126-5p. miR-126-5p regulated CDK6 expression by binding to the 3'-untranslated region of its mRNA. Overexpression miR-126-5p inhibited the proliferation and migration of esophageal cancer cells by targeting CDK6 and negatively regulating its expression. These findings contribute to the understanding of the underlying molecular mechanism of esophageal cancer.

miR-449a Is Related to Short-Term Recurrence of Hepatocellular Carcinoma and Inhibits Migration and Invasion by Targeting Notch1

PURPOSE

To explore the effect of miR-449a inhibits migration and invasion by targeting Notch1 and regulating epithelial-mesenchymal transition (EMT) in hepatocellular carcinoma (HCC), and further study on the molecular mechanism.

PATIENTS AND METHODS

The expression of miR-449a and Notch1 in HCC cells and tissues was detected by qRT-PCR. The HCC cell line HCCLM3 and SMMC-7721 were transfected with miR-449a. The invasion and migration of HCC cell lines were detected by transwell assay and wound healing assay. The Notch pathway and EMT related protein were detected with Western Blotting. The specific binding site of mir-449a on notch1 gene was detected by luciferase assay.

RESULTS

We found the expression of miR-449a was related to short-term recurrence of hepatocellular carcinoma after hepatectomy and acted as independent risk factors of DFS and OS. The expression of miR-449a decreased in tumor tissues and HCC cell lines, but the expression of Notch1 increased. The overexpressed miR-449a promoted the invasiveness in vitro by regulating EMT via Notch pathway. Mechanically, miR-449a inhibited the translation of Notch1 protein by binding to 3' UTR of its mRNA directly.

CONCLUSION

miR-449a is short-term recurrence-related miRNA and inhibits the invasion and metastasis ability of HCC cells by regulating EMT via Notch pathway. miR-449a may be a new effective therapeutic target for HCC.

Knockdown of miR-10a-5p inhibits gastric cancer cell growth and metastasis by targeting THBS2

BACKGROUND

Many microRNAs (miRNAs) have been found to play a role in inhibiting or promoting the pathogenesis and progression of gastric cancer (GC). However, there are a large number of miRNAs whose roles in GC are still unclear. Therefore, it is still necessary to continue screening miRNAs that affect the growth and metastasis of GC cells.

AIM

To investigate the effect of miR-10a-5p on the growth and metastasis of GC cells and the underlying mechanism.

METHODS

The expression levels of miR-10a-5p in GC tissues and GC cells (MGC-803 and AGS) were detected by real-time quantitative PCR (RT-qPCR). After transfecting miR-10a-5p-inhibitor into MGC-803 and AGS cells, the proliferation, colony formation, migration, and invasion of GC cells were detected by CCK-8 assay, colony formation assay, and transwell assay. The protein and mRNA expression levels of THBS2 in GC tissues and GC cells (MGC-803 and AGS) were detected by Western blot and RT-qPCR, respectively. The potential target genes of miR-10a-5p were predicted with TargetScan software and further verified. After NC + pcDNA-Con, miR-10a-5p inhibitor + pcDNA-Con, or miR-10a-5p inhibitor + pcDNA-THBS2 were co-transfected into MGC-803 cells, the proliferation, colony formation, migration, and invasion of MGC-803 cells were detected by CCK-8 assay, colony formation assay, and transwell assay.

RESULTS

The expression levels of miR-10a-5p were up-regulated in GC tissues as well as MGC-803 and AGS cells. Knockdown of miR-10a-5p significantly decreased the proliferation, colony formation, and migration and invasion of MGC-803 and AGS cells. THBS2 mRNA and protein levels were down-regulated in GC tissues as well as MGC-803 cells and AGS cells. THBS2 was identified to be a target gene of miR-10a-5p. Overexpression of THBS2 could reverse the inhibitory effect of miR-10a-5p knockdown on the proliferation, colony formation, migration, and invasion of MGC-803 cells.

CONCLUSION

Knockdown of miR-10a-5p inhibits the growth and metastasis of GC cells by targeting THBS2.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

miR-142-3p is a tumor suppressor that inhibits estrogen receptor expression in ER-positive breast cancer

Estrogen receptors (ERs) are involved in the development of many types of malignant tumors, in particular, breast cancer. Among others, ERs affect cell growth, proliferation, and differentiation. The microRNA (miRNA) miR-142-3p has been shown to inhibit carcinogenesis by regulating various cellular processes, including cell cycle progression, cell migration, apoptosis, and invasion. It does so via targeting molecules involved in a range of signaling pathways. We surgically collected 20 ER-positive breast cancer samples, each with matched adjacent normal breast tissue, and measured the expression of miR-142-3p via quantitative real-time polymerase chain reaction (qRT-PCR). Bioinformatics methods, luciferase reporter assay, qRT-PCR, and western blot analysis were used to assess whether miR-142-3p could target ESR1, which encodes the estrogen receptor, in ER-positive breast cancer cells and patient samples. We also restored miRNA expression and performed cell viability, cytotoxicity, and colony formation assays. Western blot analysis and qRT-PCR were used to study the expression of apoptosis and stemness markers. We found that miR-142-3p is downregulated in ER-positive breast cancers. Restoration of miR-142-3p expression in ER-positive breast cancer cells reduced cell viability, induced apoptosis via the intrinsic pathway and decreased both colony formation and the expression of stem cell markers. Bioinformatic analysis predicted miR-142-3p could bind to 3'-untranslated region ESR1 messenger RNA (mRNA). Consistently, we demonstrated that miR-142-3p reduced luciferase activity in ER-positive breast cancer cells, and decreased ESR1 expression in both mRNA and protein levels. The results revealed miR-142-3p and ESR1 expression correlated negatively in ER-positive breast cancer samples. The results suggest miR-142-3p acts as a tumor suppressor via multiple mechanisms. Thus, restoration of miR-142-3p expression, for example, via miRNA replacement therapy, may represent an effective strategy for the treatment of ER-positive breast cancer patients.

miR-210-3p mediates metabolic adaptation and sustains DNA damage repair of resistant colon cancer cells to treatment with 5-fluorouracil

Chemoresistance is the primary cause of chemotherapy failure. Compelling evidence shows that micro RNAs (miRNAs) contribute to reprogram cancer cells toward a resistant phenotype. We investigate the role of miRNAs in the response to acute treatment with 5-FU in colon cancer-resistant cells. We performed a global gene expression profile for the entire miRNA genome and found a change in the expression of four miRNAs following acute treatment with 5-FU. Among them, we focused on miR-210-3p, previously described as a key regulator of DNA damage repair mechanisms and mitochondrial metabolism. We show that miR-210-3p downregulation enables resistant cells to counteract the toxic effect of the drug increasing the expression of RAD-52 protein, responsible for DNA damage repair. Moreover, miR-210-3p downregulation enhances oxidative phosphorylation (OXPHOS), increasing the expression levels of succinate dehydrogenase subunits D, decreasing intracellular succinate levels and inhibiting HIF-1α expression. Altogether, these adaptations lead to increased cells survival following drug exposure. These evidence suggest that miR-210-3p downregulation following 5-FU sustains DNA damage repair and metabolic adaptation to counteract drug treatment.

The Clinical Potential of Oligonucleotide Therapeutics against Pancreatic Cancer

Although many diagnostic and therapeutic modalities for pancreatic cancer have been proposed, an urgent need for improved therapeutic strategies remains. Oligonucleotide therapeutics, such as those based on antisense RNAs, small interfering RNA (siRNA), microRNA (miRNA), aptamers, and decoys, are promising agents against pancreatic cancer, because they can identify a specific mRNA fragment of a given sequence or protein, and interfere with gene expression as molecular-targeted agents. Within the past 25 years, the diversity and feasibility of these drugs as diagnostic or therapeutic tools have dramatically increased. Several clinical and preclinical studies of oligonucleotides have been conducted for patients with pancreatic cancer. To support the discovery of effective diagnostic or therapeutic options using oligonucleotide-based strategies, in the absence of satisfactory therapies for long-term survival and the increasing trend of diseases, we summarize the current clinical trials of oligonucleotide therapeutics for pancreatic cancer patients, with underlying preclinical and scientific data, and focus on the possibility of oligonucleotides for targeting pancreatic cancer in clinical implications.

Recent advances in molecular biomarkers for patients with hepatocellular carcinoma

Introduction: Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide and recurrence rate after curative resection remains high. To improve HCC prognosis, novel sensitive biomarkers and targeted molecular therapies are needed. Accumulation of multiple genetic aberrations caused by pathologically derived liver damage results in HCC carcinogenesis. Elucidating the genes associated with tumorigenesis and progression of HCC may lead to the development of early detection and prognosis markers and to the identification of therapeutic targets. Areas covered: We review recently reported (January 2017-March 2019) HCC-associated molecules, including protein-coding genes, microRNAs, long non-coding RNAs, and methylated gene promoters. Expert opinion: The molecules reviewed have the potential to be clinical biomarkers and therapeutic targets for HCC. The accumulation and understanding of genetic and epigenetic data are essential to improve the management of HCC patients.

miR-330 suppresses EMT and induces apoptosis by downregulating HMGA2 in human colorectal cancer

MicroRNAs (miRNAs) are important molecular regulatorsof cellular signaling and behavior. They alter gene expression by targeting messenger RNAs, including those encoding transcriptional regulators, such as HMGA2. While HMGA2 is oncogenic in various tumors, miRNAs may be oncogenic or tumor suppressive. Here, we investigate the expression of HMGA2 and the miRNA miR-330 in a patient with colorectal cancer (CRC) samples and their effects on oncogenic cellular phenotypes. We found that HMGA2 expression is increased and miR-330 expression is decreased in CRCs and each predicts poor long-term patient survival. Stably increased miR-330 expression in human colorectal cancer cells (HCT116) and SW480 CRC cell lines downregulate the oncogenic expression of HMGA2, a predicted miR-330 target. Additionally, this promotes apoptosis and decreases cell migration and viability. Consistently, it also decreases protein-level expression of markers for epithelial-to-mesenchymal-transition (Snail-1, E-cadherin, and Vascular endothelial growth factor receptors) and transforming growth factor β signaling (SMAD3), as well as phospho- Protein kinase B (AKT) and phospho-STAT3 levels. We conclude that miR-330 acts as a tumor suppressor miRNA in CRC by suppressing HMGA2 expression and reducing cell survival, proliferation, and migration. Thus, we identify miR-330 as a promising candidate for miRNA replacement therapy for patients with CRC.

New emerging roles of CD133 in cancer stem cell: Signaling pathway and miRNA regulation

Cancer stem cells (CSC) are rare immortal cells within a tumor that are able to initiate tumor progression, development, and resistance. Advances studies show that, like normal stem cells, CSCs can be both self-renewed and given rise to many cell types, therefore form tumors. A number of cell surface markers, such as CD44, CD24, and CD133 are frequently used to identify CSCs. CD133, a transmembrane glycoprotein, either alone or in collaboration with other markers, has been mainly considered to identify CSCs from different solid tumors. However, the exactness of CD133 as a cancer stem cell biomarker has not been approved yet. The clinical importance of CD133 is as a CSC marker in many cancers. Also, it contributes to shorter survival, tumor progression, and tumor recurrence. The expression of CD133 is controlled by many extracellular or intracellular factors, such as tumor microenvironment, epigenetic factors, signaling pathways, and miRNAs. In this study, it was attempted to determine: 1) CD133 function; 2) the role of CD133 in cancer; 3) CD133 regulation; 4) the therapeutic role of CD133 in cancers.

DNA methylation and chromatin modifiers in colorectal cancer

Colorectal carcinogenesis is a multistep process involving the accumulation of genetic alterations over time that ultimately leads to disease progression and metastasis. Binding of transcription factors to gene promoter regions alone cannot explain the complex regulation pattern of gene expression during this process. It is the chromatin structure that allows for a high grade of regulatory flexibility for gene expression. Posttranslational modifications on histone proteins such as acetylation, methylation, or phosphorylation determine the accessibility of transcription factors to DNA. DNA methylation, a chemical modification of DNA that modulates chromatin structure and gene transcription acts in concert with these chromatin conformation alterations. Another epigenetic mechanism regulating gene expression is represented by small non-coding RNAs. Only very recently epigenetic alterations have been included in molecular subtype classification of colorectal cancer (CRC). In this chapter, we will provide examples of the different epigenetic players, focus on their role for epithelial-mesenchymal transition and metastatic processes and discuss their prognostic value in CRC.

MicroRNA-31 Negatively Regulates Interleukin-34 Expression In Vitro

Interleukin-34 (IL-34) is a recently discovered cytokine that promotes tissue macrophage maturation and differentiation. We previously found that 1α,25-Dihydroxyvitamin D3 up-regulated IL-34 expression in SH-SY5Y neural cells. However, whether microRNA regulates IL-34 expression is not completely clear. By using on-line TargetScan and MiRanda software, we found that there was only one conserved microRNA-31 (miR-31) binding site in the 3' untranslated region (3'UTR) of IL-34 mRNA. Intriguingly, using qPCR we demonstrated that miR-31 levels were negatively correlated to IL-34 mRNA levels in different cell lines. By examining the effect of miR-31 on IL-34 3' UTR reporter luciferase activity and on IL-34 mRNA and argonaute RISC catalytic component 2 (AGO2) binding, it was found that miR-31 bound directly to IL-34 3'UTR and regulated the post-transcriptional expression of IL-34 in MGC-803 cells. Moreover, a miR-31 mimic significantly reduced IL-34 expression levels while a miR-31 inhibitor up-regulated IL-34 expression in KYSE-45 and HT-29 cells. Taken together, these results show that miR-31 negatively regulates IL-34 expression by directly binding to the IL-34 3' UTR in vitro.

Serum miRNAs Expression and SNAP-25 Genotype in Alzheimer's Disease

MicroRNAs (miRNAs) are small non-coding RNAs that control gene expression by binding their 3' untranslated region (3'UTR) region; these molecules play a fundamental role in several pathologies, including Alzheimer's disease (AD). Synaptosomal-associated protein of 25 kDa (SNAP-25) is a vesicular protein of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) involved in neural plasticity and in the exocytosis of neurotransmitters, processes that are altered in AD. Recent results showed that a reduction of SNAP-25 is associated with dementia, and that the rs363050 SNAP-25 polymorphism correlates with cognitive decline and brain atrophy, as well as with the outcome of multistructured rehabilitation in AD patients. We verified the presence of possible correlations between the serum concentration of miRNAs that bind the SNAP-25 3'UTR region and AD. Six different microRNAs (miR-181a-5p, miR-361-3p, miR-23a-3p, miR-15b-3p, 130a-3p and miR-27b-3p) that bind the SNAP-25 3'UTR region were measured by qPCR in serum of AD patients (n = 22), mild cognitive impairment (MCI) subjects (n = 22) and age- and sex-matched controls (n = 22); analysis of results was done stratified for the rs363050 SNAP-25 genotype. Results showed that miR-27b-3p, miR-23a-3p and miR181a-5p serum concentration was significantly reduced in rs363050 SNAP-25 GG homozygous AD patients. Notably, concentration of these miRNAs was comparable in rs363050 AA homozygous AD patients, MCI and healthy controls (HCs). Data herein suggest that miRNAs that bind the SNAP-25 3'UTR region interact with SNAP-25 polymorphisms to influence the neural plasticity typical of AD brains, possibly as a consequence of modulatory activity on SNAP-25 mRNA and/or protein.

Mechanisms of vascular comorbidity in autoimmune diseases

Purpose of review

Persuasive statistics support the clinical observation that because of cardiovascular comorbidities patients with inflammatory joint disease die significantly earlier despite anti-inflammatory therapy.

Recent findings

The reason for this earlier death is multifactorial and involves a combination of a complex genetic background, environmental influences, classical cardiovascular risk factors and the impact of anti-inflammatory therapy. We will describe the importance of several new mechanisms, especially the diverse intercellular communication routes including extracellular vesicles and microRNAs that support the development of cardiovascular comorbidities.

Summary

The aim of this review is to give an updated overview about the known risk factors in the development of cardiovascular comorbidities with the latest insights about their mechanism of action. Furthermore, the impact of newly identified risk factors and significance will be discussed.

MicroRNA-145 replacement effect on growth and migration inhibition in lung cancer cell line

BACKGROUND

Lung cancer is the main cause of cancer death in males and females worldwide. Reduced expression of miR-145 has been reported in many types of cancers. In this study, we transfected miR-145 into lung cancer cells by vector-based miR-145, and investigated the effects of this intervention on growth and migration inhibition of cancer cells as well on the expression of targeted genes.

METHODS

IC50 of Geneticin (G418) antibiotic was measured using MTT test in NSCLC cell lines. miR-145 was transfected into lung cancer cells by jetPEI. qRT-PCR was used to evaluate the transcript level of the miR-145 and expression for KRAS, MMP-9, vimentin, caspase-3, caspase-8 and caspase-9 genes in A549 cells. MTT assay was used to evaluate the proliferation inhibition of cancer cells. Wound healing assay was used to check the migration status of transfected lung cancer cells. The apoptosis induction was assessed by DAPI staining assay.

RESULTS

The MTT assay showed that the IC50 of Genticin was 494.1 μg/ml. The results of the qRT-PCR showed increased expression level of miR-145 and downregulation of KRAS, MMP-9, and vimentin expression in A549 transfected cells compared with the control group. The MTT assay results demonstrated inhibition of cancer cell proliferation after miR-145 replacement. Wound healing assay results revealed that migration was reduced upon miR-145 transfection. The transfected cell displayed increased apoptosis rate by inducing caspase-3 and caspase-9 mRNA expression.

CONCLUSION

The results of this study showed that increased miR-145 expression exerted a critical role in subsiding the growth, survival, and migration of lung cancer cell line.

miR-532-3p promotes hepatocellular carcinoma progression by targeting PTPRT

BACKGROUND

Aberrant expression of miR-532-3p was involved in progression and development of multiple cancers, whereas miR-532-3p has not been reported in hepatocellular carcinoma (HCC). The aim of this study was to elucidate the functions of miR-532-3p in progression of HCC.

METHODS

Real-time PCR in HCC tissues and cell lines and database analysis were conducted for detection of the expression of miR-532-3p in HCC. Then, the association of miR-532-3p with clinicopathological features and prognosis of HCC patients were statistically measured. Subsequently, we attempted to observe the effects of miR-532-3p on migration, invasion and proliferation of HCC cells by Wound healing assay, Transwell assays, MTT assay and EdU assay. Furthermore, bioinformatics tools, database analysis, luciferase reporter gene assay and rescue experiments were conducted to explore the target of miR-532-3p in HCC, and to explore whether the target mediated the effects of miR-532-3p on HCC cells.

RESULTS

Our findings and data from databases consistently indicated that the miR-532-3p expression level was higher in HCC. In addition, high miR-532-3p expression was found to be closely related to larger tumor size (P =  0.0027), presence of vascular invasion (P =  0.015), and advanced TNM stage (P =  0.015). In addition, experiments in vitro revealed that miR-532-3p promotes migration, invasion and proliferation of HCC cells. Furthermore, receptor protein tyrosine phosphatase T (PTPRT) was identified as the target and mediator of miR-532-3p in HCC cells.

CONCLUSION

Our results demonstrate that miR-532-3p, which is frequently up-regulated in HCC, contributes to HCC cells mobility and proliferation through targeting PTPRT.

Regulatory mechanisms of miR-145 expression and the importance of its function in cancer metastasis

MicroRNAs are post-transcriptional mediators of gene expression and regulation, which play influential roles in tumorigenesis and cancer metastasis. The expression of tumor suppressor miR-145 is reduced in various cancer cell lines, containing both solid tumors and blood malignancies. However, the responsible mechanisms of its down-regulation are a complicated network. miR-145 is potentially able to inhbit tumor cell metastasis by targeting of multiple oncogenes, including MUC1, FSCN1, Vimentin, Cadherin, Fibronectin, Metadherin, GOLM1, ARF6, SMAD3, MMP11, Snail1, ZEB1/2, HIF-1α and Rock-1. This distinctive role of miR-145 in the regulation of metastasis-related gene expression may introduce miR-145 as an ideal candidate for controlling of cancer metastasis by miRNA replacement therapy. The present review aims to discuss the current understanding of the different aspects of molecular mechanisms of miR-145 regulation as well as its role in r metastasis regulation.

MicroRNAs and breast cancer stem cells: Potential role in breast cancer therapy

MicroRNAs (miRNAs) can control cancer and cancer stem cells (CSCs), and this topic has drawn immense attention recently. Stem cells are a tiny population of a bulk of tumor cells that have enormous potential in expansion and metastasis of the tumor. miRNA have a crucial role in the management of the function of stem cells. This role is to either promote or suppress the tumor. In this review, we investigated the function and different characteristics of CSCs and function of the miRNAs that are related to them. We also demonstrated the role and efficacy of these miRNAs in breast cancer and breast cancer stem cells (BCSC). Eventually, we revealed the metastasis, tumor formation, and their role in the apoptosis process. Also, the therapeutic potential of miRNA as an effective method for the treatment of BCSC was described. Extensive research is required to investigate the employment or suppression of these miRNAs for therapeutics approached in different cancers in the future.

Genes involved in miRNA biogenesis affect meiosis and fertility

MicroRNAs (miRNAs) are a class of small (containing about 22 nucleotides) single-stranded non-coding RNAs that regulate gene expression at the post-transcriptional level in plants and animals, being absent from unicellular organisms. They act on diverse key physiological and cellular processes, such as development and tissue differentiation, cell identity, cell cycle progression, and programmed cell death. They are also likely to be involved in a broad spectrum of human diseases. Particularly, this review examines and summarizes work characterizing the function of miRNAs in gametogenesis and fertility. Although numerous studies have elucidated the involvement of reproductive-specific small interfering RNAs (siRNAs) in regulating germ cell development and meiosis, less is known about the role of miRNAs in these processes. We focus on the study of hypomorphic and null alleles of genes encoding components of miRNA biogenesis in both plants (Arabidopsis thaliana) and mammals (Mus musculus). We compare the consequences of the presence of these mutations on male meiosis in both species.

MicroRNAs in cancer drug resistance: Basic evidence and clinical applications

Development of drug resistance has considerably limited the efficacy of cancer treatments, including chemotherapy and targeted therapies. Hence, understanding the molecular mechanisms underpinning the innate or the acquired resistance to these therapies is critical to improve drug efficiency and clinical outcomes. Several studies have implicated microRNAs (miRNA) in this process. MiRNAs repress gene expression by specific binding to complementary sequences in the 3' region of target messenger RNAs (mRNAs), followed by target mRNA degradation or blocked translation. By targeting molecules specific to a particular pathway within tumor cells, the new generation of cancer treatment strategies has shown significant advantages over conventional chemotherapy. However, the long-term efficacy of targeted therapies often remains poor, because tumor cells develop resistance to such therapeutics. Targeted therapies often involve monoclonal antibodies (mAbs), such as those blocking the ErB/HER tyrosine kinases, epidermal growth factor receptor (cetuximab) and HER2 (trastuzumab), and those inhibiting vascular endothelial growth factor receptor signaling (e.g., bevacizumab). Even though these are among the most used agents in tumor medicine, clinical response to these drugs is reduced due to the emergence of drug resistance as a result of toxic effects in the tumor microenvironment. Research on different types of human cancers has revealed that aberrant expression of miRNAs promotes resistance to the aforementioned drugs. In this study, we review the mechanisms of tumor cell resistance to mAb therapies and the role of miRNAs therein. Emerging treatment strategies combine therapies using innovative miRNA mimics or antagonizers with conventional approaches to maximize outcomes of patients with cancer.

Combined seven miRNAs for early hepatocellular carcinoma detection with chronic low-dose exposure to microcystin-LR in mice

Aberrant miRNA expression has been detected in various tumor tissues, which may be considered as a marker for early cancer diagnosis. One miRNA has multiple downstream target genes, which can be regulated by multiple upstream other miRNAs. Hence, this dynamic regulation is likely characterized by volatility, and thus, finding the appropriate time point for tests becomes essential for the use of miRNAs as an early marker of tumor diagnosis. In this study, we established a chronic liver cancer progression model in mice by using low doses of the harmful substance microcystin-LR (MC-LR). On the basis of miRNAs microarray assay, we further tested seven miRNAs that showed characteristic expression changes in pre-hepatocarcinogenesis. Our results showed that the levels of four miRNAs (miR-122-5p, miR-125-5p, miR-199a-5p, and miR-503-5p) decreased dramatically, whereas those of two miRNAs (miR-222-5p and miR-590-5p) increased significantly in the early stages, which were all accompanied by an increase in atypia of hepatocytes. MiR-490-5p was a sensitive molecular, suitable only for evaluation of pathological changes in young mice. Therefore the combination the seven of miRNAs for a set may prove to be an effective method in healthy assessment of environmental toxicants for detection of hepatocarcinogenesis caused by hazardous materials.

MicroRNA-365 Inhibits Cell Growth and Promotes Apoptosis in Melanoma by Targeting BCL2 and Cyclin D1 (CCND1)

BACKGROUND MicroRNA-365 (miR-365) is involved in the development of a variety of cancers. However, it remains largely unknown if and how miRNAs-365 plays a role in melanoma development. MATERIAL AND METHODS In this study, we overexpressed miR-365 in melanoma cell lines A375 and A2058, via transfection of miR-365 mimics oligos. We then investigated alterations in a series of cancer-related phenotypes, including cell viability, cell cycle, apoptosis, colony formation, and migration and invasion capacities. We also validated cyclin D1 (CCND1) and BCL2 apoptosis regulator (BCL2) as direct target genes of miR-365 by luciferase reporter assay and investigated their roles in miR-365 caused phenotypic changes. To get a more general view of miR-365's biological functions, candidate target genes of miR-365 were retrieved via searching online databases, which were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses for potential biological functions. We then analyzed The Cancer Genome Atlas (TCGA) Skin Cutaneous Melanoma (SKCM) dataset for correlation between miR-365 level and clinicopathological features of patients, and for survival of patients with high and low miR-365 levels. RESULTS We found that miR-365 was downregulated in melanoma cells. Overexpression of miR-365 remarkably suppressed cell proliferation, induced cell cycle arrest and apoptosis, and compromised the migration and invasion capacities in A375 and A2058 cell lines. We also found that the phenotypic alterations by miR-365 were partially due to downregulation of CCND1 and BCL2 oncogenes. The bioinformatics analysis revealed that predicted targets of miR-365 were widely involved in transcriptional regulation and cancer-related signaling pathways. However, analysis of SKCM dataset failed to find differences in miR-365 level among melanoma patients at different clinicopathologic stages. The Kaplan-Meier analysis also failed to discover significant differences in overall survival and disease-free survival between patients with high and low miR-365 levels. CONCLUSIONS Our findings suggested that miR-365 might be an important novel regulator for melanoma formation and development, however, the in vivo roles in melanoma developments need further investigation.

Messenger RNA Life-Cycle in Cancer Cells: Emerging Role of Conventional and Non-Conventional RNA-Binding Proteins?

Functional specialization of cells and tissues in metazoans require specific gene expression patterns. Biological processes, thus, need precise temporal and spatial coordination of gene activity. Regulation of the fate of messenger RNA plays a crucial role in this context. In the present review, the current knowledge related to the role of RNA-binding proteins in the whole mRNA life-cycle is summarized. This field opens up a new angle for understanding the importance of the post-transcriptional control of gene expression in cancer cells. The emerging role of non-classic RNA-binding proteins is highlighted. The goal of this review is to encourage readers to view, through the mRNA life-cycle, novel aspects of the molecular basis of cancer and the potential to develop RNA-based therapies.