Involvement of human micro-RNA in growth and response to chemotherapy in human cholangiocarcinoma cell lines

Genetic Variation in MicroRNA-423 Promotes Proliferation, Migration, Invasion, and Chemoresistance in Breast Cancer Cells

MicroRNA-423 (miR-423) is highly expressed in breast cancer (BC). Previously, our group showed that the SNP rs6505162:C>A located in the pre-miR-423 was significantly associated with increased familial BC risk in patients with a strong family history of BC. Therefore, in this study, we evaluated the functional role of rs6505162 in mammary tumorigenesis in vitro to corroborate the association of this SNP with BC risk. We found that rs6505162:C>A upregulated expression of both mature miR-423 sequences (3p and 5p). Moreover, pre-miR-423-A enhanced proliferation, and promoted cisplatin resistance in BC cell lines. We also showed that pre-miR-423-A expression decreased cisplatin-induced apoptosis, and increased BC cell migration and invasion. We propose that the rs6505162-A allele promotes miR-423 overexpression, and that the rs6505162-A allele induces BC cell proliferation, viability, chemoresistance, migration, and invasion, and decreases cell apoptosis as a consequence. We suggest that rs6505162:C>A is a functional SNP site with potential utility as a marker for early diagnosis, prognosis, and treatment efficacy monitoring in BRCA1/2-negative BC patients, as well as a possible therapeutic target.

S16020 pyridocarbazole derivatives display high activity to lung cancer cells

BACKGROUND

Despite the dynamic development of medicine, globally cancer diseases remain the second leading cause of death. Therefore, there is a strong necessity to improve chemotherapy regimens and search for new anticancer agents. Pyridocarbazoles are compounds with confirmed antitumor properties based on multimodal mechanisms, i.a. DNA intercalation and topoisomerase II-DNA complex inhibition. One of them, S16020, displayed a wide spectrum of activity.

OBJECTIVE

The aim of the study was to investigate the antitumor potency of six S16020 derivatives, synthesized according to the SAR (structure-activity relationship) method.

METHODS

The biological evaluation included influence on cancer cell viability, proliferation, and migration, as well as P-glycoprotein activity. NHDF, A549, MCF-7, LoVo, and LoVo/DX cell lines were used in the study.

RESULTS

All derivatives displayed low toxicity to normal (NHDF) cells at 1 and 2 µM (≤ 20% of cell growth inhibition). The highest reduction in cell viability was noted in A549 cells which was accompanied by significant disruption of cells proliferation and motility. Compound 1 exhibited the strongest cytotoxic, antiproliferative, and antimigratory effects, higher than the reference olivacine. A significant reduction in P-glycoprotein activity was found for derivatives 6 and 1.

CONCLUSION

S16020 derivatives could be considered as potential candidates for new anticancer drugs.

Targeting Bone Metastases Signaling Pathway Using Moringa oleifera Seed Nutri-miRs: A Cross Kingdom Approach

Moringa oleifera is a medicinally important plant that has various medical and nutritional uses. Plant miRNAs are a class of non-coding endogenous small RNAs that regulate human-specific mRNA but the mechanistic actions are largely unknown. Here, in this study, we aim to explore the mechanistic action and influence of M. oleifera seed miRNAs on vital human target genes using computer based approaches. The M. oleifera seed miRNAs sequence was taken from published data and identified its human gene targets using a psRNA target analysis server. We identified 94 miRNAs that are able to significantly regulate 47 human target genes, which has enormous biological and functional importance. Out of 47 human targeted genes, 23 genes were found to be associated with PI3K-AKT, RUNX, and MAPK1/MAPK3 signaling pathway which has shown to play key roles in bone metastases during cancer progression. The M. oleifera seed miRNAs hold a strong potential for future research that might uncover the possibility of miRNA-facilitated cross-kingdom regulation and therapeutic targets for bone metastases.

Comprehensive review on signaling pathways of dietary saponins in cancer cells suppression

Nutrigenomics utilizes high-throughput genomic technologies to reveal changes in gene and protein levels. Excitingly, ever-growing body of scientific findings has provided sufficient evidence about the interplay between diet and genes. Cutting-edge research and advancements in genomics, epigenetics and metabolomics have deepened our understanding on the role of dietary factors in the inhibition of carcinogenesis and metastasis. Dietary saponins, a type of triterpene glycosides, are generally found in Platycodon grandifloras, Dioscorea oppositifolia, asparagus, legumes, and sea cucumber. Wealth of information has started to shed light on pleiotropic mechanistic roles of dietary saponins in cancer prevention and inhibition. In this review, we have attempted to summarize the in vitro research of dietary saponins in the last two decades by searching common databases such as Google Scholar, PubMed, Scopus, and Web of Science. The results showed that dietary saponins exerted anti-cancer activities via regulation of apoptosis, autophagy, arrest cell cycle, anti-proliferation, anti-metastasis, and anti-angiogenesis, by regulation of several critical signaling pathways, including MAPK, PI3K/Akt/mTOR, NF-κB, and VEGF/VEGFR. However, there is no data about the dosage of dietary saponins for practical anti-cancer effects in human bodies. Extensive clinical studies are needed to confirm the effectiveness of dietary saponins for further commercial and medical applications.

Circulating microRNAs as biomarkers in bile-derived exosomes of cholangiocarcinoma

Purpose

In this pilot study, using next-generation sequencing and integrated messenger RNA (mRNA) sequencing, we investigated circulating microRNA (miRNA) expression profiling from bile-derived exosomes to identify dysregulated miRNA signatures and oncogenic pathways and determine their effects on targeted mRNAs in cholangiocarcinoma (CCA). Moreover, we explored the possibility that genetic analysis using bile-derived exosomes may replace gene analysis using tissue.

Methods

Bile was collected from a patient with perihilar CCA before curative resection. As a control, bile was collected from a patient with a common bile duct stone. Exosomes were isolated from the bile, and we performed next-generation miRNA sequencing using isolated exosomes. To evaluate miRNA-mRNA interactions, mRNA sequencing was performed using bile fluid in both patients.

Results

We identified 22 differentially expressed miRNAs. More than 65% of the predicted mRNA targets of those miRNAs were actually differentially expressed between control and CCA bile samples. In functional pathway analysis, targets of 22 miRNAs were primarily enriched in mitogen-activated protein kinase, platelet derived growth factor, vascular endothelial growth factor, epidermal growth factor receptor, and p53 signaling. In particular, in the functional assessment of miRNA-mRNA interactions, RAS pathways, including downstream pathways (PI3K-AKT-mTOR and RAS-RAF-MEK-ERK), were determined to be enriched.

Conclusion

Circulating miRNAs in bile-derived exosomes provide new information for the development of miRNA analysis in CCA. These miRNAs may represent the oncogenic characteristics of CCA tissue, enabling them to be used instead of tissue samples for the diagnosis of CCA. Further research investigating circulating miRNAs in bile exosomes may lead to more rational, targeted approaches to treatment.

Cholangiocarcinoma and liver transplantation: What we know so far?

Cholangiocarcinoma (CCA) is a type of cancer with increasing prevalence around the world that originates from cholangiocytes, the epithelial cells of the bile duct. The tumor begins insidiously and is distinguished by high grade neoplasm, poor outcome, and high risk for recurrence. Liver transplantation has become broadly accepted as a treatment option for CCA. Liver transplantation is expected to play a crucial role as palliative and curative therapy for unresectable hilar CCA and intrahepatic CCA. The purpose of this study was to determine which cases with CCA should be subjected to liver transplantation instead of resection, although reported post-transplant recurrence rate averages approximately 20%. This review also aims to highlight the molecular current frontiers of CCA and directions of liver transplantation for CCA.

MicroRNAs as Potential Predictors of Response to CDK4/6 Inhibitor Treatment

Simple Summary

MicroRNAs are endogenous non-coding 20–22 nucleotide long RNAs that play a fundamental role in the post-transcriptional control of gene expression. Consequently, microRNAs are involved in multiple biological processes of cancer and could be used as biomarkers with prognostic and predictive significance. Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have become a mainstay of treatment for patients with advanced hormone receptor-positive (HR) breast cancer. Despite the initial high response rates, approximately 10% of patients demonstrate primary resistance to CDK4/6 inhibitors while acquired resistance is almost inevitable. Considering the fundamental role of miRNAs in tumorigenesis, we aimed to explore the potential involvement of microRNAs in response to CDK4/6 inhibition in solid tumors. A number of microRNAs were shown to confer resistance or sensitivity to CDK4/6 inhibitors in preclinical studies, although this remains to be proved in human studies.

Abstract

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have emerged as novel treatment options in the management of advanced or metastatic breast cancer. MicroRNAs are endogenous non-coding 19–22-nucleotide-long RNAs that regulate gene expression in development and tumorigenesis. Herein, we systematically review all microRNAs associated with response to CDK4/6 inhibitors in solid tumors and hematological malignancies. Eligible articles were identified by a search of the MEDLINE and ClinicalTrials.gov databases for the period up to1 January 2021; the algorithm consisted of a predefined combination of the words “microRNAs”, “cancer” and “CDK 4/6 inhibitors”. Overall, 15 studies were retrieved. Six microRNAs (miR-126, miR-326, miR3613-3p, miR-29b-3p, miR-497 and miR-17-92) were associated with sensitivity to CDK4/6 inhibitors. Conversely, six microRNAs (miR-193b, miR-432-5p, miR-200a, miR-223, Let-7a and miR-21) conferred resistance to treatment with CDK4/6 inhibitors. An additional number of microRNAs (miR-124a, miR9, miR200b and miR-106b) were shown to mediate cellular response to CDK4/6 inhibitors without affecting sensitivity to treatment. Collectively, our review provides evidence that microRNAs could serve as predictive biomarkers for treatment with CDK4/6 inhibitors. Moreover, microRNA-targeted therapy could potentially maximize sensitivity to CDK4/6 inhibition.

MicroRNA and cyclooxygenase-2 in breast cancer

Cancer remains a major public health problem worldwide and the latest statistics show that breast cancer (BC) is among the most frequent in women. MicroRNAs (miRNAs; miRs) and cyclooxygenase-2 (COX-2) are new diagnostic and therapeutic biomarkers for monitoring BC. COX-2 is a prominent tumor-associated inflammatory factor highly expressed in human tumor cells, including BC. Expression of COX-2 contributes to tumor growth, metastasis and recurrence. MiRs are a group of short (~22 nucleotides), noncoding regulatory RNAs that downregulate gene expression post-transcriptionally and play vital roles in regulating cancer development and progression. Interestingly, there are a group of miRNAs differentially expressed in breast tumor tissue. Understanding the pathway linking miRNAs to COX-2 can provide novel insight for suppressing COX-2 expression via gene silencing thereby leading to the development of selective miRNA inhibitors. Further research can also reveal key intermediate players and their potential as therapeutic targets. Given the association between different miRNAs and COX-2 expression in BC, this review presents a comprehensive overview of the current literature concerning how miRNAs and COX-2 signaling interact in BC progression.

Pioglitazone Attenuates Lupus Nephritis Symptoms in Mice by Modulating miR-21-5p/TIMP3 Axis: the Key Role of the Activation of Peroxisome Proliferator-Activated Receptor-γ

Lupus nephritis (LN) is a severe symptom of systemic lupus erythematosus and miR-21-5p is upregulated during LN. In the current study, the effects of pioglitazone (Pg), a peroxisome proliferator-activated receptor-γ (PPARγ) agonist, on LN development were assessed and explained by focusing miR-21-5p/TIMP3 axis. The expressions of miR-21-5p and PPARγ in LN mice were detected and then the mice were treated with pioglitazone to evaluate the anti-LN effects of agent. The miR-21-5p level was induced in MRL/lpr mice to confirm the central role of miR-21-5p inhibition in the protective effects of Pg against LN. The level of miR-21-5p was upregulated, while the level of PPARγ was downregulated in MRL/lpr mice. Pg inhibited miR-21-5p in renal tissues, which induced the expression of TIMP3. The changes in miR-21-5p/TIMP3 axis led to the improvements in renal structure and function, and inhibited autoimmune response. The induction of miR-21-5p impaired the effects of Pg, along with the suppression of TIMP3. The expression of miR-21-5p was associated with the progression of LN, contributing to the suppression of TIMP3 and development of LN. The inhibition of the miR-21-5p by Pg would restore the structure and function of kidneys in LN mice via the activation of PPARγ.

Dynamic Evaluation of Circulating miRNA Profile in EGFR-Mutated NSCLC Patients Treated with EGFR-TKIs

BACKGROUND

Resistance to EGFR-TKIs constitutes a major challenge for the management of EGFR-mutated NSCLC, and recent evidence suggests that deregulation of specific microRNAs (miRNAs) may influence resistance to targeted agents. In this retrospective study, we explored the role of specific plasmatic miRNAs (miR-21, miR-27a and miR-181a) as a surrogate for predicting EGFR-TKI performance in EGFR-mutated NSCLC patients.

METHODS

Plasma samples of 39 advanced EGFR-mutated NSCLC patients treated with EGFR-TKIs were collected at different points in time and miRNA levels were assessed by RT-PCR.

RESULTS

Higher basal values of miR-21 were reported in patients who achieved a partial/complete response (PR/CR) compared to those with stability/progression of disease (SD/PD) (p = 0.011). Along the same line, patients who experienced a clinical benefit lasting at least six months displayed higher basal levels of circulating miR-21 (p = 0.039). However, dynamic evaluation of miRNA values after two months from the start of EGFR-TKI treatment showed that patients who experienced SD had an increase in miR-21 levels (Fold Change [FC] = 2.6) compared to patients achieving PR/CR (p = 0.029). The same tendency was observed for miR-27a (FC = 3.1) and miR-181a (FC = 2.0), although without reaching statistical significance. Remarkably, preclinical studies showed an increase in miR-21 levels in NSCLC cells that became resistant after exposure to EGFR-TKIs.

CONCLUSIONS

Our study provides interesting insights on the role of circulating miRNAs, in particular miR-21, and their dynamic change over time in predicting EGFR-TKI response in EGFR-mutated NSCLC.

LIX1-like protein promotes liver cancer progression via miR-21-3p-mediated inhibition of fructose-1,6-bisphosphatase

Limb and CNS expressed 1 like (LIX1L) is over-expressed in several types of tumors. However, the function of LIX1L in glucose metabolism and hepatocellular carcinoma (HCC) progression remains elusive. Here we report that LIX1L is over-expressed in human HCC tissues, which predicts unfavorable prognosis. LIX1L deficiency in vivo significantly attenuated liver cancer initiation in mice. Functional studies indicated that LIX1L overexpression elevated proliferation, migratory, invasive capacities of HCC cells in vitro, and promoted liver cancer growth and metastasis in vivo. LIX1L knockdown up-regulated fructose-1,6-bisphosphatase (FBP1) expression to reduce glucose consumption as well as lactate production. Mechanistically, LIX1L increased miR-21-3p expression, which targeted and suppressed FBP1, thereby promoting HCC growth and metastasis. MiR-21-3p inhibitor could abrogate LIX1L induced enhancement of cell migration, invasion, and glucose metabolism. Inhibition of miR-21-3p suppressed tumor growth in an orthotopic tumor model. Our results establish LIX1L as a critical driver of hepatocarcinogenesis and HCC progression, with implications for prognosis and treatment.

Circadian rhythm genes in cancer: insight into their functions and regulation involving noncoding RNAs

The 24-h circadian rhythm handles a wide variety of physiological needs. Clock genes, in coordination with other tissue-specific factors regulate various processes and often turns responsible for the pathological conditions when altered. Cancer is one such disease where the clock genes have been shown to contribute at multiple levels modulating key hallmarks of cancer. Most importantly, adding to this complication, noncoding RNAs (ncRNAs) have emerged as one of the major post-transcriptional regulators of gene expression and many recent studies have indicated about involvement of microRNAs or long noncoding RNAs in the process. In this review, we have described how do circadian pathway genes participated in oncogenesis and also updated the latest status of ncRNA involvement. We also try to address the existing gaps to have a more comprehensive understanding of the phenomenon in future.Abbreviations: HIFs: hypoxia-inducible factors; VEGF: Vascular endothelial growth factor; Mdm2: Mouse double minute 2 homolog; ATM: Ataxia telangiectasia mutated; Chk2: Checkpoint kinase 2; Bcl-Xl: B-cell lymphoma-extra-large; Bcl-2: B-cell lymphoma 2; DGCR8: DiGeorge syndrome chromosomal region 8; PPAR-γ: Peroxisome proliferator-activated receptor gamma.

Research Progress in Prognostic Factors and Biomarkers of Ovarian Cancer

Ovarian cancer is a serious threat to women's health; its early diagnosis rate is low and prone to metastasis and recurrence. The current conventional treatment for ovarian cancer is a combination of platinum and paclitaxel chemotherapy based on surgery. The recurrence and progression of ovarian cancer with poor prognosis is a major challenge in treatment. With rapid advances in technology, understanding of the molecular pathways involved in ovarian cancer recurrence and progression has increased, biomarker-guided treatment options can greatly improve the prognosis of patients. This review systematically discusses and summarizes existing and new information on prognostic factors and biomarkers of ovarian cancer, which is expected to improve the clinical management of patients and lead to effective personalized treatment.

MiR-21 in the Cancers of the Digestive System and Its Potential Role as a Diagnostic, Predictive, and Therapeutic Biomarker

MicroRNAs (miRNAs) are small non-coding RNAs. They can regulate the expression of their target genes, and thus, their dysregulation significantly contributes to the development of cancer. Growing evidence suggests that miRNAs could be used as cancer biomarkers. As an oncogenic miRNA, the roles of miR-21 as a diagnostic and prognostic biomarker, and its therapeutic applications have been extensively studied. In this review, the roles of miR-21 are first demonstrated via its different molecular networks. Then, a comprehensive review on the potential targets and the current applications as a diagnostic and prognostic cancer biomarker and the therapeutic roles of miR-21 in six different cancers in the digestive system is provided. Lastly, a brief discussion on the challenges for the use of miR-21 as a therapeutic tool for these cancers is added.

Plasma Circulating Mirnas Profiling for Identification of Potential Breast Cancer Early Detection Biomarkers

OBJECTIVE

This study aimed to characterize the miRNA expression profiles from plasma samples of our local breast cancer patients in comparison to healthy control by using miRNA PCR Array.

METHODS

In this study, plasma miRNA profiles from eight early-stage breast cancer patients and nine age-matched (± 2 years) healthy controls were characterized by miRNA array-based approach, followed by differential gene expression analysis, Independent T-test and construction of Receiver Operating Characteristic (ROC) curve to determine the capability of the assays to discriminate between breast cancer and the healthy control.

RESULTS

Based on the 372-miRNAs microarray profiling, a set of 40 differential miRNAs was extracted regarding to the fold change value at 2 and above. We further sub grouped 40 miRNAs of breast cancer patients that were significantly expressed at 2-fold change and higher. In this set, we discovered that 24 miRNAs were significantly upregulated and 16 miRNAs were significantly downregulated in breast cancer patients, as compared to the miRNA expression of healthy subjects. ROC curve analysis revealed that seven miRNAs (miR-125b-5p, miR-142-3p, miR-145-5p, miR-193a-5p, miR-27b-3p, miR-22-5p and miR-423-5p) had area under curve (AUC) value > 0.7 (AUC p-value < 0.05). Overlapping findings from differential gene expression analysis, ROC analysis, and Independent T-Test resulted in three miRNAs (miR-27b-3p, miR-22-5p, miR-145-5p). Cohen's effect size for these three miRNAs was large with d value are more than 0.95.

CONCLUSION

miR-27b-3p, miR-22-5p, miR-145-5p could be potential biomarkers to distinguish breast cancer patients from healthy controls. A validation study for these three miRNAs in an external set of samples is ongoing.
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miR-21: A Key Small Molecule with Great Effects in Combination Cancer Therapy

The increasing incidence of various cancers indicates the urgent need for finding accurate early diagnostic markers and more effective treatments for these malignancies. MicroRNAs (miRNAs) are small noncoding RNAs with great potentials to enter into cancer clinics as both diagnostic markers and therapeutic targets. miR-21 is elevated in many cancers, and promotes cell proliferation, metastasis, and drug resistance. In recent years, many studies have shown that targeting miR-21 combined with conventional chemotherapeutic agents could enhance their therapeutic efficacy, and overcome drug resistance and cancer recurrence both in vitro and in animal models. In this review, we first summarize the effects and importance of miR-21 in various cancers, and explore its function in drug resistance of cancer cells. Next, the challenges and prospects for clinical translation of anti-miR-21, as a therapeutic agent, will be discussed in combination cancer therapy.

MiR-30a and miR-200c differentiate cholangiocarcinomas from gastrointestinal cancer liver metastases

Prior studies have demonstrated the utility of microRNA assays for predicting some cancer tissue origins, but these assays need to be further optimized for predicting the tissue origins of adenocarcinomas of the liver. We performed microRNA profiling on 195 frozen primary tumor samples using 14 types of tumors that were either adenocarcinomas or differentiated from adenocarcinomas. The 1-nearest neighbor method predicted tissue-of-origin in 33 samples of a test set, with an accuracy of 93.9% at feature selection p values ranging from 10-4 to 10-10. According to binary decision tree analyses, the overexpression of miR-30a and the underexpression of miR-200 family members (miR-200c and miR-141) differentiated intrahepatic cholangiocarcinomas from extrahepatic adenocarcinomas. When binary decision tree analyses were performed using the test set, the prediction accuracy was 84.8%. The overexpression of miR-30a and the reduced expressions of miR-200c, miR-141, and miR-425 could distinguish intrahepatic cholangiocarcinomas from liver metastases from the gastrointestinal tract.

A High-Accuracy Model Based on Plasma miRNAs Diagnoses Intrahepatic Cholangiocarcinoma: A Single Center with 1001 Samples

Objectives: Intrahepatic cholangiocarcinoma (iCCA) is a highly malignant cancer. More than 70% of patients are diagnosed at an advanced stage. The aim of this study was to evaluate the diagnostic value of plasma miR-21, miR-122, and CA19-9, hoping to establish a novel model to improve the accuracy for diagnosing iCCA. Materials and methods: Plasma miR-21 and miR-122 were detected in 359 iCCA patients and 642 controls (healthy, benign liver lesions, other malignant liver tumors). All 1001 samples were allocated to training cohort (n = 668) and validation cohort (n = 333) in a chronological order. A logistic regression model was applied to combine these markers. Area under the receiver operating characteristic curve (AUC) was used as an accuracy index to evaluate the diagnostic performance. Results: Plasma miR-21 and miR-122 were significantly higher in iCCA patients than those in controls. Higher plasma miR-21 level was significantly correlated with larger tumor size (p = 0.030). A three-marker model was constructed by using miR-21, miR-122 and CA19-9, which showed an AUC of 0.853 (95% CI: 0.824–0.879; sensitivity: 73.0%, specificity: 87.4%) to differentiate iCCA from controls. These results were subsequently confirmed in the validation cohort with an AUC of 0.866 (0.825–0.901). The results were similar for diagnosing early (stages 0–I) iCCA patients (AUC: 0.848) and CA19-9^negative iCCA patients (AUC: 0.795). Conclusions: We established a novel three-marker model with a high accuracy based on a large number of participants to differentiate iCCA from controls. This model showed a great clinical value especially for the diagnosis of early iCCA and CA19-9^negative iCCA.

Circular RNAs: A Promising Biomarker for Endometrial Cancer

Endometrial cancer (EC) is one of the most common malignant tumors of the female reproductive tract. EC patients have high morbidity and mortality rates and remain an important cause of cancer-related morbidity and mortality worldwide. More and more studies have shown that a large number of non-coding RNAs (such as microRNAs and long non-coding RNAs) are associated with the occurrence of diseases. Circular RNAs (circRNAs) is an endogenous non-coding RNA. It has a unique covalent structure. Many studies in recent years have found circRNAs differential expression in a variety of tumor tissues compared to matched normal tissues. In endometrial carcinoma, there also are multiple circRNAs differentially expressed and therefore circRNAs perhaps can be used as a diagnostic and prognosis biomarkers of EC. In this review, we described the biogenesis, function and characteristics of circRNAs, and the circRNAs with potential influence and clinical significance on the development of EC were summarized. Adenocarcinoma is the most common form of EC, so this review focuses on endometrioid adenocarcinoma.

miR-21 inhibition reverses doxorubicin-resistance and inhibits PC3 human prostate cancer cells proliferation

Many approaches have been examined to reversing multidrug resistance (MDR), but sub-optimal target-based strategies have limited their efficacy. Herein, we investigate microRNA (miR-21) suppression on the doxorubicin (DOX)-sensitisation of the DOX-resistant (PC3/DOX) cell line in prostate cancer (PCa). Expression levels of miR-21, P-glycoprotein (P-gp), MDR-1 and PTEN evaluated in PC3/DOX cancer cells by qRT-PCR and western blot analyses. The cytotoxic effects of transfected of miR-21 were assessed by MTT assay for 72 hr. Rhodamine123 (Rh123) assay was employed to define the activity of P-gp. Apoptosis was detected by Flow cytometry. As expected, miR-21 was expressed highly in PC3/DOX cells (p < 0.05). It was shown that miRNA-21 suppression considerably hindered PC3/DOX cell viability. miR-21 suppression dramatically downregulated P-gp expression and activity in DOX-resistance cells and abolished MDR by an increment of intracellular accumulation of DOX in PC3/DOX cells (p < 0.05). PTEN is a key modulator of the PI3K/Akt/P-gp cascade, which miR-21 suppression led to the upregulation of PTEN and sequentially lower-expression of P-gp that reversed MDR. Also, miR-21 repression enhanced the apoptosis rate of PC3/DOX cells. The findings of this paper contribute to the current understanding of the functions of miR-21 in MDR-reversing in PCa.

Immune Therapy Resistance and Immune Escape of Tumors

Simple Summary

The genetic adaptability of malignant cells and their consequent heterogeneity even within the same patient poses a great obstacle to cancer patient treatment. This review summarizes the data obtained in the last decade on different preclinical mice models as well as on various immunotherapeutic clinical trials in distinct solid and hematopoietic cancers on how the immune system can be implemented in tumor therapy. Moreover, the different intrinsic and extrinsic escape strategies utilized by the tumor to avoid elimination by the immune system are recapitulated together with the different approaches proposed to overcome them in order to succeed and/or to enhance therapy efficacy.

Abstract

Immune therapy approaches such as checkpoint inhibitors or adoptive cell therapy represent promising therapeutic options for cancer patients, but their efficacy is still limited, since patients frequently develop innate or acquired resistances to these therapies. Thus, one major goal is to increase the efficiency of immunotherapies by overcoming tumor-induced immune suppression, which then allows for immune-mediated tumor clearance. Innate resistance to immunotherapies could be caused by a low immunogenicity of the tumor itself as well as an immune suppressive microenvironment composed of cellular, physical, or soluble factors leading to escape from immune surveillance and disease progression. So far, a number of strategies causing resistance to immunotherapy have been described in various clinical trials, which broadly overlap with the immunoediting processes of cancers. This review summarizes the novel insights in the development of resistances to immune therapy as well as different approaches that could be employed to overcome them.

Pathogenetic Role and Clinical Implications of Regulatory RNAs in Biliary Tract Cancer

Biliary tract cancer (BTC) is characterised by poor prognosis and low overall survival in patients. This is generally due to minimal understanding of its pathogenesis, late diagnosis and limited therapeutics in preventing or treating BTC patients. Non-coding RNA (ncRNA) are small RNAs (mRNA) that are not translated to proteins. ncRNAs were considered to be of no importance in the genome, but recent studies have shown they play essential roles in biology and oncology such as transcriptional repression and degradation, thus regulating mRNA transcriptomes. This has led to investigations into the role of ncRNAs in the pathogenesis of BTC, and their clinical implications. In this review, the mechanisms of action of ncRNA are discussed and the role of microRNAs in BTC is summarised. The scope of this review will be limited to miRNA as they have been shown to play the most significant roles in BTC progression. There is huge potential in miRNA-based biomarkers and therapeutics in BTC, but more studies, research and technological advancements are required before it can be translated into clinical practice for patients.

The Cell Type-Specific Functions of miR-21 in Cardiovascular Diseases

Cardiovascular diseases are one of the prime reasons for disability and death worldwide. Diseases and conditions, such as hypoxia, pressure overload, infection, and hyperglycemia, might initiate cardiac remodeling and dysfunction by inducing hypertrophy or apoptosis in cardiomyocytes and by promoting proliferation in cardiac fibroblasts. In the vascular system, injuries decrease the endothelial nitric oxide levels and affect the phenotype of vascular smooth muscle cells. Understanding the underlying mechanisms will be helpful for the development of a precise therapeutic approach. Various microRNAs are involved in mediating multiple pathological and physiological processes in the heart. A cardiac enriched microRNA, miR-21, which is essential for cardiac homeostasis, has been demonstrated to act as a cell–cell messenger with diverse functions. This review describes the cell type–specific functions of miR-21 in different cardiovascular diseases and its prospects in clinical therapy.

miR-21-5p Suppresses Mitophagy to Alleviate Hyperoxia-Induced Acute Lung Injury by Directly Targeting PGAM5

Hyperoxia-induced acute lung injury (HALI) is a severe side effect of refractory hypoxemia treatment, for which no effective therapeutic strategy is available. Here, we found that the lung miR-21-5p level was significantly decreased in the rats subjected to hyperoxia. Further, we presented evidence that miR-21-5p was a crucial regulator of mitophagy and mitochondrial dysfunction. Moreover, it proved that miR-21-5p regulated hyperoxia-induced mitophagy and mitochondrial dysfunction by directly binding to the target gene PGAM5. In conclusion, for the first time, we found that miR-21-5p could directly suppress mitophagy and mitochondrial damage during HALI formation.

The Effect of Gemcitabine on Cell Cycle Arrest and microRNA Signatures in Pancreatic Cancer Cells

BACKGROUND/AIM

Gemcitabine, an inhibitor of DNA synthesis, is the gold standard chemotherapeutic agent for pancreatic ductal adenocarcinoma (PDAC). MicroRNAs (miRNAs) play critical roles in cancers, including PDAC. However, less is known about the effect of gemcitabine on PDAC cells and miRNA expression in PDAC. We evaluated the effect of gemcitabine on the cell cycle of PDAC cells in vitro and in vivo and on the miRNA expression profile.

MATERIALS AND METHODS

Effects of gemcitabine on PK-1 and PK-9 cell growth were evaluated using a cell counting kit-8 assay. Xenografted mouse models were used to assess gemcitabine effects in vivo.

RESULTS

Gemcitabine inhibited the proliferation and tumour growth of PK-1 cells, and induced S phase cell cycle arrest. Numerous miRNAs were altered upon gemcitabine treatment of PK-1 cells and xenograft models.

CONCLUSION

Altered miRNAs may serve as potential therapeutic targets for improving the efficacy of gemcitabine in PDAC.

Circular RNA MTO1 inhibits gastric cancer progression by elevating PAWR via sponging miR-199a-3p

The effect of circular RNA MTO1 (circMTO1) signaling on the expression of miR-199a-3p in gastric carcinoma cells, and its effect on proliferation and apoptosis of gastric cancer cells were investigated in this study. RT-qPCR was performed to detect the expression levels of circMTO1 and miR-199a-3p in the cell lines and tissues of gastric cancer. The effect of circMTO1 and miR-199a-3p on the growth and apoptosis of tumor cells was detected by BrdU incorporation and Annexin V/PI staining. Target gene prediction and screening, and luciferase reporter assays were performed to validate downstream interested genes of circMTO1 and miR-199a-3p. The expression levels of miR-199a-3p target gene PAWR (named as PRKC apoptosis WT1 Regulator Protein) was measured by RT-qPCR and Western blotting. Tumor changes in mice were detected by transfecting circMTO1. The expression of circMTO1 was significantly downregulated in the cell lines and tissues of gastric cancer, and low expression levels of circMTO1 were closely associated with poor prognosis. Overexpression of circMTO1 inhibited tumor growth, enhanced apoptosis rate and decreased cell invasion and migration. There was a significant negative relationship between the expression levels of circMTO1 and miR-199a-3p in gastric cancer tissues. Inhibiting miR-199a-3p expression or overexpression of PAWR could decrease the promotive effects of knockdown of circMTO1 on the progression of gastric cancer, and a positive relationship was established between the expression of circMTO1 and PAWR. circMTO1 can regulate the growth of gastric cancer cells by regulating miR-199a-3p/PAWR axis, thus inhibiting the development and progression of gastric cancer. Abbreviation GC: Gastric cancer; circ RNA: Circular RNA; MTO1: mitochondrial translation optimized 1 homolog.

miR-34a regulates lipid metabolism by targeting SIRT1 in non-alcoholic fatty liver disease with iron overload

BACKGROUND

Micro-ribonucleic acids (miRNAs) have been implicated in the regulation of non-alcoholic fatty liver disease (NAFLD), a leading cause of chronic liver disease worldwide. The mechanisms by which miR-34a influences NAFLD through the Sirtuin 1 (SIRT1)-related pathway were investigated herein.

METHODS

Male C57BL/6 mice were injected with a miR-34a lentivirus vector inhibitor or control. HepG2 cells were transfected with a miR-34a mimic, inhibitor, SIRT1 small interfering RNA (siRNA), SIRT1 plasmid, and a negative oligonucleotide control to evaluate their role in oleic acid (OA) and excess iron-induced NAFLD. The accumulation of lipids in the mice liver and HepG2 cells was analyzed by triglyceride (TG) detection and hematoxylin and eosin (HE) staining. Additionally, the indexes of oxidative stress related to lipid metabolism were evaluated by western blotting and real-time PCR (qRT-PCR). The levels of intracellular reactive oxygen species (ROS) and mitochondrial membrane potentials were measured by flow cytometry and laser confocal microscopy, respectively. Finally, the dual luciferase reporter assay was conducted to further confirm whether SIRT1 was a direct target of miR-34a.

RESULTS

Overexpression of miR-34a resulted in increased triglyceride accumulation as well as in decreased mitochondrial membrane potential and SIRT1 levels. Silencing of miR-34a increased SIRT1 expression and alleviated triglyceride accumulation in the presence of OA and iron. Additionally, miR-34a directly inhibited SIRT1 by binding to the 3'-untranslated region, as determined via the luciferase reporter assay.

CONCLUSIONS

Our results support the existence of a link between the liver cell mitochondria and miR-34a/SIRT1 signaling. Potential endogenous modulators of NAFLD pathogenesis may ultimately provide new tools for therapeutic intervention.

Identification of Prognostic Markers in Cholangiocarcinoma Using Altered DNA Methylation and Gene Expression Profiles

Background

Cholangiocarcinoma (CCA) is a rare disease, but it is amongst the most lethal cancers with a median survival under 1 year. Variations in DNA methylation and gene expression have been extensively studied in other cancers for their role in pathogenesis and disease prognosis, but these studies are very limited in CCA. This study focusses on the identification of DNA methylation and gene expression prognostic biomarkers using multi-omics data of CCA tumors from The Cancer Genome Atlas (TCGA).

Method

We have conducted a genome-wide analysis of differential DNA methylation and gene/miRNA expression using data from 36 CCA tumor and 9 normal samples from TCGA. The impact of DNA methylation in promoters and long-range distal enhancers on the regulation and expression of CCA-associated genes was examined using linear regression. Next, we conducted network analyses on genes which are regulated by DNA methylation as well as by miRNA. Finally, we performed Kaplan–Meier and Cox proportional hazards regression analyses in order to identify the role of selected methylation sites and specific genes and miRNAs in patient survival. We also performed real-time quantitative PCR (qPCR) to confirm the change in gene expression in CCA patients’ tumor and adjacent normal samples.

Results

Altered DNA methylation was observed on 12,259 CpGs across all chromosomes, of which 78% were hypermethylated. We observed a strong negative relationship between promoter hypermethylation and corresponding gene expression in 92% of the CpGs. Differential expression analyses revealed altered expression patterns in 3,305 genes and 101 miRNAs. Finally, we identified 17 differentially methylated promoter CpGs, 72 differentially expressed genes, and two miRNAs that are likely associated with patient survival. Pathway analysis suggested that cell division, bile secretion, amino acid metabolism, PPAR signaling, hippo signaling were highly affected by gene expression and DNA methylation alterations. The qPCR analysis further confirmed that MDK, HNF1B, PACS1, and GLUD1 are differentially expressed in CCA.

Conclusion

Based on the survival analysis, we conclude that DEPDC1, FUT4, MDK, PACS1, PIWIL4 genes, miR-22, miR-551b microRNAs, and cg27362525 and cg26597242 CpGs can strongly support their use as prognostic markers of CCA.

The Emerging Role of MicroRNAs in Regulating the Drug Response of Cholangiocarcinoma

Cholangiocarcinoma (CCA) is the most common biliary malignancy, and has a poor prognosis. The median overall survival with the standard-of-care chemotherapy (Gemcitabine and cisplatin) in patients with advanced-stage CCA is less than one year. The limited efficacy of chemotherapy or targeted therapy remains a major obstacle to improving survival. The mechanisms involved in drug resistance are complex. Research efforts focusing on the distinct molecular mechanisms underlying drug resistance should prompt the development of treatment strategies that overcome chemoresistance or targeted drug resistance. MicroRNAs (miRNAs) are a class of evolutionarily conserved, short noncoding RNAs regulating gene expression at the post-transcriptional level. Dysregulated miRNAs have been shown to participate in almost all CCA hallmarks, including cell proliferation, migration and invasion, apoptosis, and the epithelial-to-mesenchymal transition. Emerging evidence demonstrates that miRNAs play a role in regulating responses to chemotherapy and targeted therapy. Herein, we present an overview of the current knowledge on the miRNA-mediated regulatory mechanisms underlying drug resistance among CCA. We also discuss the application of miRNA-based therapeutics to CCA, providing the basis for innovative treatment approaches.

Current and novel therapeutic opportunities for systemic therapy in biliary cancer

Biliary tract cancers (BTCs) are a group of rare and aggressive malignancies that arise in the biliary tree within and outside the liver. Beyond surgical resection, which is beneficial for only a small proportion of patients, current strategies for treating patients with BTCs include chemotherapy, as a single agent or combination regimens, in the adjuvant and palliative setting. Increased characterisation of the molecular landscape of these tumours has facilitated the identification of molecular vulnerabilities, such as IDH mutations and FGFR fusions, that can be exploited for the treatment of BTC patients. Beyond targeted therapies, active research avenues explore the development of novel therapeutics that target the crosstalk between cancer and stroma, the cellular pathways involved in the regulation of cell death, the chemoresistance phenotype and the dysregulation of RNA. In this review, we discuss the therapeutic opportunities currently available in the management of BTC patients, and explore the strategies that can support the implementation of precision oncology in BTCs, including novel molecular targets, liquid biopsies and patient-derived predictive tools.

Progress in the correlation between PTPN12 gene expression and human tumors

BACKGROUND

The global morbidity of cancer is rising rapidly. Despite advances in molecular biology, immunology, and cytotoxic and immune-anticancer therapies, cancer remains a major cause of death worldwide. Protein tyrosine phosphatase non-receptor type 12 (PTPN12) is a new member of the cytoplasmic protein tyrosine phosphatase family, isolated from a cDNA library of adult colon tissue. Thus far, no studies have reviewed the correlation between PTPN12 gene expression and human tumors.

METHODS

This article summarizes the latest domestic and international research developments on how the expression of PTPN12 relates to human tumors. The extensive search in Web of Science and PubMed with the keywords including PTPN12, tumor, renal cell carcinoma, proto-oncogenes, tumor suppressor genes was undertaken.

RESULTS

More and more studies have shown that a tumor is essentially a genetic disease, arising from a broken antagonistic function between proto-oncogenes and tumor suppressor genes. When their antagonistic effect is out of balance, it may cause uncontrolled growth of cells and lead to the occurrence of tumors. PTPN12 is a tumor suppressor gene, so inhibiting its activity will lead directly or indirectly to the occurrence of tumors.

CONCLUSION

The etiology, prevention, and treatment of tumors have become the focus of research around the world. PTPN12 is a tumor suppressor gene. In the future, PTPN12 might serve as a novel molecular marker to benefit patients, and even the development of tumor suppressor gene activation agents can form a practical research direction.

Galangin Inhibits Cholangiocarcinoma Cell Growth and Metastasis through Downregulation of MicroRNA-21 Expression

Galangin, a natural flavonoid product derived from the root of galangal, is emerging as a promising anticancer agent against multiple cancers. Yet, whether it also has antitumor effects on cholangiocarcinoma (CCA) and the underlying mechanism is still unknown. Herein, we demonstrate that galangin exhibits multiple antitumor effects on CCA cells including decreases cell viability; inhibits proliferation, migration, and invasion; and induces apoptosis. Moreover, those phenotypic changes are associated with downregulated microRNA-21 (miR-21) expression. To support, overexpression of miR-21 blocks galangin-mediated antisurvival and metastasis effects on CCA cells. Mechanically, galangin increases the expression of phosphatase and tensin homolog (PTEN), a direct target of miR-21, resulting in decreased phosphorylation of AKT, a protein kinase which plays a critical role in controlling survival and apoptosis. In contrast, overexpression of miR-21 abrogates galangin-regulated PTEN expression and AKT phosphorylation. Taken together, these findings indicate that galangin inhibits CCA cell proliferation and metastasis and induces cell apoptosis through a miR-21-dependent manner, and galangin may provide a novel potential therapeutic adjuvant to treat CCA.

The Complex Landscape of PTEN mRNA Regulation

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a key tumor suppressor in the development and progression of different tumor types. Emerging data indicate that small reductions in PTEN protein levels can promote cancer. PTEN protein levels are tightly controlled by a plethora of mechanisms beginning with epigenetic and transcriptional regulation and ending with control of protein synthesis and stability. PTEN messenger RNA (mRNA) is also subject to exquisite regulation by microRNAs, coding and long noncoding RNAs, and RNA-binding proteins. Additionally, PTEN mRNA is markedly influenced by alternative splicing and variable polyadenylation. Herein we provide a synoptic description of the current understanding of the complex regulatory landscape of PTEN mRNA regulation including several specific processes that modulate its stability and expression, in the context of PTEN loss-associated cancers.

Role of noncoding RNAs in cholangiocarcinoma (Review)

Cholangiocarcinoma (CCA) is a malignant tumour originating from biliary epithelial cells, and is increasing in incidence. Radical surgery is the main treatment. However, the pathogenesis of CCA is unclear. Noncoding RNAs (ncRNAs) are non‑protein‑coding RNAs produced by genomic transcription that include microRNAs (miRNAs), circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs). They play important roles in gene expression, epigenetic modification, cell proliferation, differentiation and reproduction. ncRNAs also serve key roles in cancer development. Numerous studies have been carried out on ncRNAs, and associated publications have shown that ncRNAs are closely associated with the physiological and pathological mechanisms of CCA. The findings of these studies can provide new insights into the diagnosis, treatment and prognosis of CCA. The present review summarizes the pathophysiological mechanisms of different types of ncRNAs, including miRNAs, circRNAs and lncRNAs in CCA, and their applications in the diagnosis and treatment of CCA.

The mechanistic, diagnostic and therapeutic novel nucleic acids for hepatocellular carcinoma emerging in past score years

Despite The Central Dogma states the destiny of gene as 'DNA makes RNA and RNA makes protein', the nucleic acids not only store and transmit genetic information but also, surprisingly, join in intracellular vital movement as a regulator of gene expression. Bioinformatics has contributed to knowledge for a series of emerging novel nucleic acids molecules. For typical cases, microRNA (miRNA), long noncoding RNA (lncRNA) and circular RNA (circRNA) exert crucial role in regulating vital biological processes, especially in malignant diseases. Due to extraordinarily heterogeneity among all malignancies, hepatocellular carcinoma (HCC) has emerged enormous limitation in diagnosis and therapy. Mechanistic, diagnostic and therapeutic nucleic acids for HCC emerging in past score years have been systematically reviewed. Particularly, we have organized recent advances on nucleic acids of HCC into three facets: (i) summarizing diverse nucleic acids and their modification (miRNA, lncRNA, circRNA, circulating tumor DNA and DNA methylation) acting as potential biomarkers in HCC diagnosis; (ii) concluding different patterns of three key noncoding RNAs (miRNA, lncRNA and circRNA) in gene regulation and (iii) outlining the progress of these novel nucleic acids for HCC diagnosis and therapy in clinical trials, and discuss their possibility for clinical applications. All in all, this review takes a detailed look at the advances of novel nucleic acids from potential of biomarkers and elaboration of mechanism to early clinical application in past 20 years.

Identification of Cholangiocarcinoma Associated with Hepatolithiasis via the Combination of miRNA and Ultrasound

Background

Identification of cholangiocarcinoma (CCA) associated with hepatolithiasis (HL) is difficult. There is no effective method to discriminate CCA associated with HL (HL-CCA) from HL currently.

Objective

To explore the value of clinical data, ultrasonic characteristics and miRNA expression level in the identification of HL-CCA.

Methods

Thirty-one patients with HL-CCA in Huazhong University of Science and Technology Union Shenzhen Hospital were enrolled in the observation group, while 40 patients with HL alone were included in the control group. The clinical data, ultrasonic characteristics, and miRNA expression level of the two groups were recorded and analyzed to explore the potential indicators for the identification of HL-CCA.

Results

The accuracy of ultrasound in the diagnosis of HL-CCA was low (54.84%). Multivariate logistic regression analysis showed that liver abscess (P=0.021), indistinct border demarcation (P=0.015), non-homogenous echotexture (P=0.019), missed portal vein around lesion (P=0.032), miRNA-21 (P=0.018) and miRNA-221 (P=0.009) were the potential indicators for the identification of HL-CCA. The combined diagnosis based on logistic regression contained liver abscess, border demarcation, echotexture, portal vein around lesion, miRNA-21 and miRNA-221. The results showed that the accuracy of combined diagnosis identifying HL-CCA was the most accurate (AUC=0.911), which was significantly greater than the AUC of miRNA-21 or miRNA-221 individually (P<0.05), with a sensitivity and specificity of 77.42% and 97.50%, respectively.

Conclusion

Patients with HL-CCA show high incidence of hepatic abscess and elevated miRNA-21 and miRNA-221 expression level. The ultrasonic features are more likely to show indistinct border demarcation, non-homogenous echotexture, and missed portal vein around lesion. The combined diagnosis is more accurate in the identification of HL-CCA.

Therapeutic Potential of Autophagy Modulation in Cholangiocarcinoma

Autophagy is a multistep catabolic process through which misfolded, aggregated or mutated proteins and damaged organelles are internalized in membrane vesicles called autophagosomes and ultimately fused to lysosomes for degradation of sequestered components. The multistep nature of the process offers multiple regulation points prone to be deregulated and cause different human diseases but also offers multiple targetable points for designing therapeutic strategies. Cancer cells have evolved to use autophagy as an adaptive mechanism to survive under extremely stressful conditions within the tumor microenvironment, but also to increase invasiveness and resistance to anticancer drugs such as chemotherapy. This review collects clinical evidence of autophagy deregulation during cholangiocarcinogenesis together with preclinical reports evaluating compounds that modulate autophagy to induce cholangiocarcinoma (CCA) cell death. Altogether, experimental data suggest an impairment of autophagy during initial steps of CCA development and increased expression of autophagy markers on established tumors and in invasive phenotypes. Preclinical efficacy of autophagy modulators promoting CCA cell death, reducing invasiveness capacity and resensitizing CCA cells to chemotherapy open novel therapeutic avenues to design more specific and efficient strategies to treat this aggressive cancer.

miR-373 inhibits autophagy and further promotes apoptosis of cholangiocarcinoma cells by targeting ULK1

Intrahepatic cholangiocarcinoma is a malignant tumor originating from intrahepatic bile ducts. Surgical therapy, radiotherapy, and chemotherapy are taken to treat this disease, but it is prone to recurrence and metastasis, with poor prognosis. Therefore, it is of great significance to explore new targets and molecular mechanisms for the development of cholangiocarcinoma cells. Clinical cholangiocarcinoma tissues from patients and four human cholangiocarcinoma cell lines were analyzed for microRNA-373 (miR-373) expression. For investigating whether miR-373 directly modulated unc-51 like autophagy activating kinase 1 (ULK1), dual-luciferase reporter assay was performed. In addition, CCK-8 assay, flow cytometry, western blot, and immunofluorescence were applied to evaluate the proliferation, apoptosis, and autophagy of cholangiocytic hepatocellular carcinoma cells. miR-373 downregulation was observed in clinical tissues and cell lines of cholangiocarcinoma. Overexpression of miR-373 reduced proliferation, enhanced apoptosis, and raised expression levels of pro-apoptosis proteins including BCL2 associated X (Bax), Caspase-3, and Caspase-9. Moreover, overexpression of miR-373 downregulated expression levels of microtubule-associated protein 1A/1B-light chain 3 (LC3)-II, Beclin-1, and promoted P62 expression on mRNA and protein levels. After miR-373 knockdown, all indexes of apoptosis and autophagy mentioned above were reversed. Luciferase activity was decreased after cotransfection of miR-373 mimic and wild-type ULK1 vector. Also, miR-373 overexpression inhibited ULK1 expression. Importantly, overexpression of miR-373 weakened expressions of ULK1, LC3, Beclin-1, and Bcl-2, and enhanced expressions of P62, Bax, Caspase-3, and Caspase-9. miR-373 mimic treatment and subsequent ULK1 overexpression, induced reverse regulation in expressions of these proteins, compared with overexpression of miR-373 only. miR-373 targeted ULK1 to initiate inhibition of autophagy and subsequent promotion of apoptosis in cholangiocarcinoma cells.

IL22 drives cutaneous melanoma cell proliferation, migration and invasion through activation of miR-181/STAT3/AKT axis

Cutaneous melanoma (CM) is neoplastic growth of melanocytes with strong potential to proliferate and invade, prone to a fatal disease soon which is beyond surgical clearance. The use of regulator involving in antitumor immune responses has been identified as a potential therapeutic option for CM, but still need fully understood at present. Recently, interleukin 22 (IL22), an immune molecule secreted mostly by CD4⁺ T cells, was reported having functions in a variety of human diseases including encouragement of lung cancer progression, yet, its role in CM is lacking. Here, we first found elevated expression of IL22 in both serum of CM patients and tissues. Up-regulated IL22 significantly promoted cell proliferation, migration and invasion in CM cells deriving from different original culture history. Moreover, in vivo CM model, IL22 treatment caused a significant increase in tumor size. Additionally, we found these effects accompanied by obvious increased miR-181 expression in CM. Importantly, both in vivo and in vitro results revealed that miR-181 downregulation reversed the effects of IL22 on CM cell proliferation, migration, invasion, and CM tumor size as well. Finally, in CM cells deriving from different culture history, we identified STAT3 to be a target gene of miR-181. Higher expression level of IL22 suppressed STAT3 expression, while enhanced expression of p-AKT, p-β-catenin and MMP4; however, down-regulation of miR-181 reversed these situations. Thus, we conclude that IL22 promotes CM progression by driving miR-181/STAT3/AKT axis.

MiR-21, EGFR and PTEN in non-small cell lung cancer: an in situ hybridisation and immunohistochemistry study

AIMS

To analyse microRNA (miR)-21 distribution and expression at the cellular level in non-small cell lung cancer (NSCLC). MiR-21 is an oncogenic microRNA overexpressed in NSCLC. In previous studies, overexpression of miR-21 was evaluated from the tumour bulk by quantitative reverse transcription PCR with results expressed on average across the entire cell population.

METHODS

We used in situ hybridisation and immunohistochemistry to assess the correlation between miR-21 levels and the expression of markers that may be possible targets (epidermal growth factor reaction) or may be involved in its upregulation (phosphatase and tensin homolog (PTEN), p53). The Pearson's χ² tests was used to assess correlation with clinicopathological data and with miR-21 expression both in tumour and tumour stroma.

RESULTS

Cytoplasmic staining and expression of Mir-21 were detected in the tumours and in associated stromal cells. Expression was highest in the stroma immediately surrounding the tumour cells and decreased as the distance from the tumour increased. No expression of miR-21 was found in normal lung parenchyma and a significant association was found between tumour localised miR-21 and PTEN.

CONCLUSIONS

Presence of miR-21 in both cell tumour and stromal compartments of NSCLC and the relationship with PTEN confirms miR-21 as a microenvironment signalling molecule, possibly inducing epithelial mesenchymal transition and invasion by targeting PTEN in the stromal compartment possibly through exosomal transport. In situ immunohistochemical studies such as ours may help shed light on the complex interactions between miRNAs and its role in NSCLC biology.

Circulating microRNAs as Biomarkers of Radiation Exposure: A Systematic Review and Meta-Analysis

PURPOSE

MicroRNAs (miRNAs) were hypothesized to be robust and easily measured biomarkers of radiation exposure, which has led to multiple studies in various clinical and experimental scenarios. We sought to identify evolutionary conserved, radiation-induced circulating miRNAs through a multispecies, integrative systematic review and meta-analysis of miRNAs in radiation.

METHODS AND MATERIALS

The systematic review was registered in the PROSPERO database (ID: 81701). We downloaded a list of studies with the query: (circulating OR plasma OR serum) AND (miRNA or microRNA) AND (radiat* OR radiotherapy OR irradiati*) from MEDLINE (103 studies), EMBASE (364 studies), and Cochrane Database of Systematic Reviews (0 studies). After deleting 116 duplicates, the remaining 351 abstracts were reviewed. Inclusion criteria were experimental study; human, mice, rat or nonhuman primate study; and serum or plasma miRNA expression measured before and after radiation exposure.

RESULTS

The screening procedure yielded 62 research studies. After verification, 30 articles contained data on miRNA expression change after irradiation. Thus, we obtained a database of 131 miRNAs from 96 pairwise post-/preirradiation comparisons reporting 2508 fold changes (FCs) of circulating miRNAs. The meta-analysis showed 28 miRNAs with significant radiation-induced change of their expression in the serum. In metaregression analysis, 7 miRNAs-miR-150 (FC = 0.40; 95% confidence interval [CI], 0.35-0.45), miR-29a (FC = 0.87; 95% CI, 0.79-0.96), miR-29b (FC = 0.85; 95% CI, 0.76-0.96), miR-30c (FC = 1.19; 95% CI, 1.09-1.30), miR-200b (FC = 1.34; 95% CI, 1.21-1.48), miR-320a (FC = 1.13; 95% CI, 1.05-1.23), and miR-30a (FC = 1.18; 95% CI, 1.07-1.30)-significantly correlated with either total or fraction dose of radiation. Additionally, miR-150, miR-320a, miR-200b, and miR-30c correlated significantly with time elapsed since irradiation.

CONCLUSIONS

Circulating miRNAs reflect the impact of ionizing radiation irrespective of the studied species, often in a dose-dependent manner. This makes circulating miRNAs promising biomarkers of radiation exposure.

Function and mechanisms of microRNA-20a in colorectal cancer

Colorectal cancer (CRC) is the third most common malignancy and the second leading cause of cancer-associated mortality worldwide. CRC currently has no specific biomarkers to promote its diagnosis and treatment and the underlying mechanisms regulating its pathogenesis have not yet been determined. MicroRNAs (miRs) are small, non-coding RNAs that exhibit regulatory functions and have been demonstrated to serve a crucial role in the post-transcriptional regulatory processes of gene expression that is associated with cell physiology and disease progression. Recently, abnormal miR-20a expression has been identified in a number of cancers types and this has become a novel focus within cancer research. High levels of miR-20a expression have been identified in CRC tissues, serum and plasma. In a recent study, miR-20a was indicated to be present in feces and to exhibit a high sensitivity to CRC. Therefore, miR-20a may be used as a marker for CRC and an indicator that can prevent the invasive examination of patients with this disease. Changes in the expression of miR-20a during chemotherapy can be used as a biomarker for monitoring resistance to treatment. In conclusion, miR-20a exhibits the potential for clinical application as a novel diagnostic biomarker and therapeutic target for use in patients with CRC. The present study focused on the role and mechanisms of miR-20a in CRC.

Identification of drug resistance associated ncRNAs based on comprehensive heterogeneous network

AIMS

Chemotherapy and molecularly targeted therapy are main strategies for treatment of cancers. However, long-term treatment makes cancer cells acquire resistance to anti-cancer drugs, which severely limits the effects of cancer treatment. NcRNAs, especially miRNAs and lncRNAs, have been reported to play key roles in drug resistance and could restore drug responses in resistant cells.

MAIN METHODS

We presented a network-based framework to systematically identify drug resistance associated miRNAs and lncRNAs. First, we constructed a comprehensive heterogeneous miRNA-lncRNA regulatory network through integrating curated miRNA regulations to lncRNA, and significantly co-expressed miRNA-miRNA, lncRNA-lncRNA and miRNA-lncRNA interactions for each cancer type. Second, random walk with restart (RWR) was utilized to identify novel drug resistance associated ncRNAs.

KEY FINDINGS

We predicted 470 associations of 34 miRNAs and 79 lncRNAs for 27 drugs in 10 cancer types. In addition, leave-one-out cross validation (LOOCV) demonstrated the effectiveness of the proposed approach. Next, we also demonstrated that the integrated heterogeneous cancer-specific network achieved better performance than the general curated miRNA-lncRNA regulatory network. What's more, we found that the drug resistance associated ncRNAs validated by high-throughput technology was also a reliable source for prediction.

SIGNIFICANCE

We proposed a new framework to identify novel and reliable drug resistance associated ncRNAs, which provides new perspectives for drug resistance mechanism and new guidance for clinical cancer treatment.

MiR-203a-3p targets PTEN to promote hepatocyte proliferation by regulating PI3K/Akt pathway in BRL-3A cells

This study was designed to investigate the role of miR-203a-3p in hepatocyte proliferation. Data analysis showed that up-regulation of miR-203a-3p increased the cell viability and cell proliferation, and inhibited apoptosis. Further experiments demonstrated that PTEN was a target gene of miR-203a-3p, and miR-203a-3p targeted PTEN to regulate the above functions. Overexpression of PTEN partially reversed the inhibition of PTEN and the activation of p-Akt/Akt induced by miR-203a-3p mimic. Our study revealed that miR-203a-3p might activate PI3K/Akt signaling pathway by inhibiting PTEN expression, thereby promoting cell proliferation.

The integrative knowledge base for miRNA-mRNA expression in colorectal cancer

"miRNA colorectal cancer" (https://mirna-coadread.omics.si/) is a freely available web application for studying microRNA and mRNA expression and their correlation in colorectal cancer. To the best of our knowledge, "miRNA colorectal cancer" has the largest knowledge base of miRNA-target gene expressions and correlations in colorectal cancer, based on the largest available sample size from the same source of data. Data from high-throughput molecular profiling of 295 colon and rectum adenocarcinoma samples from The Cancer Genome Atlas was analyzed and integrated into our knowledge base. The objective of developing this web application was to help researchers to discover the behavior and role of miRNA-target gene interactions in colorectal cancer. For this purpose, results of differential expression and correlation analyses of miRNA and mRNA data collected in our knowledge base are available through web forms. To validate our knowledge base experimentally, we selected genes FN1, TGFB2, RND3, ZEB1 and ZEB2 and miRNAs hsa-miR-200a/b/c-3p, hsa-miR-141-3p and hsa-miR-429. Both approaches revealed a negative correlation between miRNA hsa-miR-200b/c-3p and its target gene FN1 and between hsa-miR-200a-3p and its target TGFB2, thus supporting the usefulness of the developed knowledge base.

An insight of microRNAs performance in carcinogenesis and tumorigenesis; an overview of cancer therapy

Importance of dysregulation and expression of microRNAs (miRNAs) has been confiemed in many disorders comprising cancer. In this way, different approaches to induce reprogramming from one cell type to another in oerder to control the cell normal mechanisem, comprising microRNAs, combinatorial small molecules, exosome-mediated reprogramming, embryonic microenvironment and also lineage-specific transcription agents, are involved in cell situation. Meaningly, besides the above factors, microRNAs are so special and have an impressive role in cell reprogramming. One of the main applications of cancer cell reprogramming is it's ability in therapeutic approach. Many insights in reprogramming mechanism have been recommended, and determining improvment has been aknolwged to develop reprogramming efficiency and possibility, permiting it to appear as practical therapy against all cancers. Conspiciously, the recent studies on the fluctuations and performance of microRNAs,small endogenous non-coding RNAs, as notable factors in carcinogenesis and tumorigenesis, therapy resistance and metastasis and as new non-invasive cancer biomarkers has a remarkable attention. This is due to their unique dysregulated signatures throughout tumor progression. Recognising miRNAs signatures capable of anticipating therapy response and metastatic onset in cancers might enhance diagnosis and therapy. According to the growing reports on miRNAs as novel non-invasive biomarkers in various cancers as a main regulators of cancers drug resistance or metastasis, the quest on whether some miRNAs have the ability to regulate both simultaneously is inevitable, yet understudied. The combination of genetic diagnosis using next generation sequencing and targeted therapy may contribute to the effective precision medicine for cancer therapy. Here, we want to review the practical application of microRNAs performance in carcinogenesis and tumorigenesis in cancer therapy.

miR‑21‑5p ameliorates hyperoxic acute lung injury and decreases apoptosis of AEC II cells via PTEN/AKT signaling in rats

Inhibiting apoptosis of type II alveolar epithelial cells (AEC II) is an effective way to decrease hyperoxic acute lung injury (HALI); however, the specific underlying molecular mechanisms have not yet been fully elucidated. Although miRNA‑21‑5p has previously been reported to decrease H2O2‑induced AEC II apoptosis by targeting PTEN in vitro, whether miR‑21‑5p can decrease HALI in vivo and the downstream molecular mechanisms remain unclear. In the present study, rats were endotracheally administered with an miR‑21‑5p‑encoding (AAV‑6‑miR‑21‑5p) or a negative control adenovirus vector, and then a HALI model was established by exposure to hyperoxia. At 3 weeks following the administration of AAV‑6‑miR‑21‑5p, the severity of HALI was decreased, as evidenced by the improved outcome of the oxygenation index, respiratory index, wet/dry weight ratio and pathological scores of the HALI lungs. To further investigate the underlying mechanisms, AEC II cells were isolated from the lungs of the experimental rats and cultured. The expression levels of miR‑21‑5p and its target gene, PTEN, were detected, as well as the levels of phosphorylated and total AKT. In addition, the apoptosis rate of AEC II was detected by flow cytometry. The results demonstrated that AAV‑6‑miR‑21‑5p administration increased the miR‑21‑5p levels in primary AEC II cells, while it decreased the expression levels of PTEN. miR‑21‑5p overexpression also increased AKT phosphorylation in AEC II cells from the HALI lungs compared with that of the HALI alone group and the control virus group. The present study indicated that miR‑21‑5p ameliorated HALI in vivo, which may have resulted from the inhibition of PTEN/AKT‑induced apoptosis of AEC II cells. These findings suggest that miR‑21‑5p and PTEN/AKT signaling might serve as potential targets for HALI treatment.

miR-671-5p Blocks The Progression Of Human Esophageal Squamous Cell Carcinoma By Suppressing FGFR2

Esophageal cancer is the eighth most common malignant tumor worldwide, of which esophageal squamous cell carcinoma (ESCC) is the dominant histological subtype. A drug shortage for ESCC therapy triggered us to explore the roles of fibroblast growth factor receptor 2 (FGFR2) and its upstream regulator miR-671-5p in ESCC progression. We compared the levels of FGFR2 and miR-671-5p between human ESCC tissues and their matched normal esophageal tissues and found an association between higher levels of FGFR2 and lower levels of miR-671-5p in ESCC tissues. High levels of FGFR2 resulted in the activation of the ERK and AKT pathways and a promotion of ESCC progression. High levels of miR-671-5p specifically reduced the expression of FGFR2 and suppressed ESCC progression in both in vitro and in vivo models. Therefore, suppressing FGFR2 and enhancing miR-671-5p expression may be the right approaches for ESCC therapy.