MicroRNA biogenesis pathway genes polymorphisms and cancer risk: a systematic review and meta-analysis

Alternate Causes for Pathogenesis of Exfoliation Glaucoma, a Multifactorial Elastotic Disorder: A Literature Review

Exfoliation glaucoma (XFG) is the most recognizable form of secondary open-angle glaucoma associated with a high risk of blindness. This disease is characterized by white flaky granular deposits in the anterior chamber that leads to the elevation of intraocular pressure (IOP) and subsequent glaucomatous optic nerve damage. Conventionally, XFG is known to respond poorly to medical therapy, and surgical intervention is the only management option in most cases. Various genetic and nongenetic factors are known to be linked to the development of XFG. Despite decades of research on the genetic factors in exfoliation syndrome (XFS) by study groups and global consortia involving different ethnic populations, the pathogenesis of XFS and the mechanism of onset of glaucoma still remains an unsolved mystery. The key lies in understanding how the function of a gene (or set of genes) is altered by environmental triggers, along with other molecular events that underlie the key disease attributes, namely, oxidative stress and the disruption of the blood–aqueous barrier (BAB). It remains a challenge to evolve a theory encompassing all factions of molecular events occurring independently or parallelly that determine the disease manifestation (phenotype) or the stage of the disease in the eye (or in any tissue) in exfoliation. Our enhanced understanding of the underlying molecular pathophysiology of XFG, beyond the known genes or polymorphisms involved in the disease, will lead to improved diagnosis and management and the ability to recognize how the environment influences these key events that lead to the disease phenotype or disease progression. This review summarizes the recent observations and discoveries of four key factors that may hold the answers to the non-lysyl oxidase-like 1 (LOXL1) mechanisms behind XFG pathogenesis, namely, the epigenetic factor miRNA, disordered autophagy along with the potential involvement of mitochondrial mutations, and a compromised aqueous–blood barrier.

The Role of miRNAs in Extracellular Matrix Repair and Chronic Fibrotic Lung Diseases

The lung extracellular matrix (ECM) plays a key role in the normal architecture of the lung, from embryonic lung development to mechanical stability and elastic recoil of the breathing adult lung. The lung ECM can modulate the biophysical environment of cells through ECM stiffness, porosity, topography and insolubility. In a reciprocal interaction, lung ECM dynamics result from the synthesis, degradation and organization of ECM components by the surrounding structural and immune cells. Repeated lung injury and repair can trigger a vicious cycle of aberrant ECM protein deposition, accompanied by elevated ECM stiffness, which has a lasting effect on cell and tissue function. The processes governing the resolution of injury repair are regulated by several pathways; however, in chronic lung diseases such as asthma, chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary disease (IPF) these processes are compromised, resulting in impaired cell function and ECM remodeling. Current estimates show that more than 60% of the human coding transcripts are regulated by miRNAs. miRNAs are small non-coding RNAs that regulate gene expressions and modulate cellular functions. This review is focused on the current knowledge of miRNAs in regulating ECM synthesis, degradation and topography by cells and their dysregulation in asthma, COPD and IPF.

Association between genetic variants in DICER1 and cancer risk: An updated meta-analysis

Dysfunctions in mechanisms of gene regulation based on RNA interference are recognized as a common feature of the molecular basis of cancer pathogenesis. Therefore, as one of the crucial components of the machinery involved in the biogenesis of both siRNAs and microRNA molecules, DICER was recognized as one of the candidates for the research in the field of carcinogenesis. Due to their potential functional properties, several genetic variants located within DICER1 gene were analyzed for their possible association with the susceptibility to cancer through case-control studies. In order to elucidate their effect on the overall cancer risk, we conducted an updated meta-analysis of all eligible association studies. The publications were selected based on PubMed database search, while OpenMeta-analyst and MetaGenyo software were used for quantitative data synthesis. Statistically significant results were found for the association of rs1057035 with the overall cancer risk under multiple genetic models (P_{CT vs. TT} < 0.001, OR_{CT vs. TT} = 0.870, 95% CI = 0.812-0.933; P_allelic = 0.009, OR_allelic = 0.896, 95% CI = 0.825-0.973; P_dom < 0.001, OR_dom = 0.874, 95% CI = 0.817-0.934; P_overdom = 0.004, OR_overdom = 0.858, 95% CI = 0.773-0.953). Other selected genetic variants within DICER1, rs13078, rs1209904 and rs3742330, did not show the association with the overall susceptibility to malignant diseases. We conclude that rs1057035 may represent a potential biomarker associated with the risk of developing cancer, which requires a confirmation in a larger set of studies.

miR-200b regulates breast cancer cell proliferation and invasion by targeting radixin

Radixin is an important member of the Ezrin-Radixin-Moesin protein family that is involved in cell invasion, metastasis and movement. microRNA (miR)-200b is a well-studied microRNA associated with the development of multiple tumors. Previous bioinformatics analysis has demonstrated that miR-200b has a complementary binding site in the 3'-untranslated region of radixin mRNA. The present study aimed to investigate the role of miR-200b in regulating radixin expression, cell proliferation and invasion in breast cancer. Breast cancer tissues at different Tumor-Node-Metastasis (TNM) stages were collected; breast tissues from patients with hyperplasia were used as a control. miR-200b and radixin mRNA expression levels were tested by reverse transcription-quantitative PCR. Radixin protein expression was detected by western blotting. The highly metastatic MDA-MB-231 cells were divided into four groups and transfected with a miR-negative control (NC), miR-200b mimic, small interfering (si)RNA-NC or siRNA targeting radixin. Cell invasion was evaluated by Transwell assay and cell proliferation was assessed by 5-ethynyl-2'-deoxyuridine staining. Compared with the control group, radixin mRNA expression was significantly higher in breast cancer tissues and increased with TNM stage. miR-200b expression levels exhibited the opposite trend. Radixin mRNA expression in breast cancer cells was notably higher, whereas miR-200b expression was lower compared with that in normal breast epithelial MCF-10A cells. The expression of radixin was higher, whereas miR-200b was lower in MDA-MB-231 cells compared with that in MCF-7 cells. miR-200b mimic or siRNA-radixin transfection downregulated the expression of radixin in MDA-MB-231 cells and attenuated the invasive and proliferative abilities of these cells. miR-200b-knockdown and radixin overexpression were associated with enhanced cell invasion in breast cancer. In conclusion, miR-200b regulates breast cancer cell proliferation and invasion by targeting radixin expression.

Association of microRNA biosynthesis genes XPO5 and RAN polymorphisms with cancer susceptibility: Bayesian hierarchical meta-analysis

XPO5/RAN-GTP complex mediates the nuclear transport of pre-miRNAs in the miRNA processing system, its altered expression is indicated to be correlated with cancer risk. Several studies have inspected the association between XPO5 or RAN polymorphisms and the risk of various cancers, but the findings remain controversial. A Bayesian hierarchical meta-analysis was carried out to review and analyze the effect of XPO5 and RAN polymorphisms on cancer risk. The association was estimated by calculating the logarithm of odds ratio (Log OR) and 95% credible interval (95% CrI). The expression quantitative trait loci (eQTL) analysis was used for in silico functional validation of the identified significant susceptibility loci. Consequently, 38 case-control studies (from 27 citations) with 27,459 cancer cases and 25,151controls were included in the meta-analysis of the five most prevalent SNPs (rs11077 A/C, rs2257082 G/A, rs3803012 A/G, rs14035 C/T, rs3809142 C/T). In the XPO5 gene rs11077 SNP, the minor C allele significantly increased the risk of cancer (Log OR = 0.120, 95% CrI = 0.013, 0.241), and a strong association between rs11077 SNP and cancer risk was also found in the dominant model (CC + AC vs. AA: Log OR = 0.132, 95% CrI = 0.009, 0.275). In addition, the minor GG genotype allele of the RAN gene rs3803012 SNP significantly increased the cancer risk (Log OR = 0.707, 95% CrI = 0.059, 1.385). Statistically significant associations between rs3803012 SNP and cancer risk were also observed in the recessive model (GG vs. AG + AA: Log OR = 0.708, 95% CrI = 0.059, 1.359). Furthermore, the eQTL analysis revealed that rs11077 SNP was significantly correlated with XPO5 mRNA expression, which provided additional biological basis for the observed positive association. Our results suggest that XPO5 rs11077 may be a possible functional susceptibility locus for cancer risk.

Alpha-1 Antitrypsin-A Target for MicroRNA-Based Therapeutic Development for Cystic Fibrosis

Cystic fibrosis (CF) is an autosomal recessive genetic disorder arising from mutations to the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Disruption to normal ion homeostasis in the airway results in impaired mucociliary clearance, leaving the lung more vulnerable to recurrent and chronic bacterial infections. The CF lung endures an excess of neutrophilic inflammation, and whilst neutrophil serine proteases are a crucial part of the innate host defence to infection, a surplus of neutrophil elastase (NE) is understood to create a net destructive effect. Alpha-1 antitrypsin (A1AT) is a key antiprotease in the control of NE protease activity but is ineffective in the CF lung due to the huge imbalance of NE levels. Therapeutic strategies to boost levels of protective antiproteases such as A1AT in the lung remain an attractive research strategy to limit the damage from excess protease activity. microRNAs are small non-coding RNA molecules that bind specific cognate sequences to inhibit expression of target mRNAs. The inhibition of miRNAs which target the SERPINA1 (A1AT-encoding gene) mRNA represents a novel therapeutic approach for CF inflammation. This could involve the delivery of antagomirs that bind and sequester the target miRNA, or target site blockers that bind miRNA recognition elements within the target mRNA to prevent miRNA interaction. Therefore, miRNA targeted therapies offer an alternative strategy to drive endogenous A1AT production and thus supplement the antiprotease shield of the CF lung.

Integrated analysis highlights multiple long non‑coding RNAs and their potential roles in the progression of human esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a prevalent aggressive malignant tumor with poor prognosis. Investigations into the molecular changes that occur as a result of the disease, as well as identification of novel biomarkers for its diagnosis and prognosis, are urgently required. Long non‑coding RNAs (lncRNAs) have been reported to play a critical role in tumor progression. The present study performed data mining analyses for ESCC via an integrated study of accumulated datasets and identification of the differentially expressed lncRNAs from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. The identified intersection of differentially expressed genes (lncRNAs, miRNAs and mRNAs) in ESCC tissues between the GEO and TCGA datasets was investigated. Based on these intersected lncRNAs, the present study constructed a competitive endogenous RNA (ceRNA) network of lncRNAs in ESCC. A total of 81 intersection lncRNAs were identified; 67 of these were included in the ceRNA network. Functional analyses revealed that these 67 key lncRNAs primarily dominated cellular biological processes. The present study then analyzed the associations between the expression levels of these 67 key lncRNAs and the clinicopathological characteristics of the ESCC patients, as well as their survival time using TCGA. The results revealed that 31 of these lncRNAs were associated with tumor grade, tumor‑node‑metastasis (TNM) stage and lymphatic metastasis status (P<0.05). In addition, 15 key lncRNAs were demonstrated to be associated with survival time (P<0.05). Finally, 5 key lncRNAs were selected for validation of their expression levels in 30 patients newly diagnosed with ESCC via reverse transcription‑quantitative PCR (RT‑qPCR). The results suggested that the fold changes in the trends of up‑ and downregulation between GEO, TCGA and RT‑qPCR were consistent. In addition, it was also demonstrated that a select few of these 5 key lncRNAs were significantly associated with TNM stage and lymph node metastasis (P<0.05). The results of the clinically relevant analysis and the aforementioned bioinformatics were similar, hence proving that the bioinformatics analysis used in the present study is credible. Overall, the results from the present study may provide further insight into the functional characteristics of lncRNAs in ESCC through bioinformatics integrative analysis of the GEO and TCGA datasets, and reveal potential diagnostic and prognostic biomarkers for ESCC.

miR-16 regulates proliferation and invasion of lung cancer cells via the ERK/MAPK signaling pathway by targeted inhibition of MAPK kinase 1 (MEK1)

Objective

The ERK/MAPK signaling pathway regulates cell proliferation and invasion. MAPK kinase 1 (MEK1) is a protein kinase upstream of ERK that can activate the pathway. Expression of microRNA (miR)-16 in lung cancer tissues is decreased. The aim of this study was to determine roles of miR-16 in proliferation and invasion of lung cancer cells.

Methods

We used a luciferase reporter assay to determine a regulatory relationship between miR-16 and MEK1 and assessed expression of MEK1 in normal lung cells and lung cancer cell lines. Plate cloning, flow cytometry, and Transwell experiments demonstrated the proliferation and invasion ability of cells transfected with wild-type and mutant MEK1.

Results

We confirmed a regulatory relationship between miR-16 and MEK1 mRNA. Expression of miR-16 was decreased and that of MEK1 and p-ERK1/2 were increased in lung cancer cell lines compared with normal cells. Transfection with miR-101 mimic or small interfering (si)-MEK1 significantly downregulated expression of MEK1 and p-ERK1/2 in Anip973 cells.

Conclusions

Decreased miR-16 expression may play a role in upregulating expression of MEK1 and promoting proliferation and invasion of lung cancer cells. Overexpression of miR-16 downregulated the ERK/MAPK pathway by inhibiting MEK1 expression, attenuating clone formation and invasion, and inhibiting cell proliferation.

Dietary Lutein Plus Zeaxanthin Intake and DICER1 rs3742330 A > G Polymorphism Relative to Colorectal Cancer Risk

It is unclear whether dietary lutein/zeaxanthin intake in colorectal cancer is associated with microRNA processing involved in DICER1 cleavage for messenger RNA translation. We investigated whether dietary lutein/zeaxanthin intake affects colorectal cancer risk in patients with a DICER1 rs3742330 polymorphism. In this hospital-based case-control study, we recruited 923 colorectal cancer patients and 1,846 controls based on eligibility criteria, a semiquantitative food frequency questionnaire and the DICER1 rs3742330 genotype. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by unconditional logistic regression adjusted for confounders. The highest quartile of lutein/zeaxanthin consumption was inversely associated with a reduced colorectal cancer risk (OR, 95% CI = 0.25, 0.18-0.36). Carrying G allele (AG + GG) showed a significantly reduced colorectal cancer incidence compared with that of AA carriers (OR, 95% CI = 0.71, 0.55-0.91). Those carrying the G allele (AG + GG) along with high lutein/zeaxanthin consumption were markedly associated with a decreased colorectal cancer risk (OR, 95% CI = 0.32, 0.22-0.46, P for interaction = 0.018), particularly for rectal cancer (OR, 95% CI = 0.24, 0.15-0.39, P for interaction = 0.004), compared with that of AA carriers with low lutein/zeaxanthin intakes. In conclusion, colorectal cancer risk was related to an interactive effect between dietary lutein/zeaxanthin intake and the DICER1 rs3742330 polymorphism.

Association between miRNA-146a rs2910164 (G/C) polymorphism with the susceptibility to chronic HBV infection and spontaneous viral clearance in an Iranian population

Hepatitis B virus (HBV) infection is one of the clinical dilemmas in chronic liver diseases. MicroRNAs (miRNAs) are small noncoding RNA molecules that play an important role in the pathogenesis of liver diseases and single nucleotide polymorphisms (SNPs) in miRNA genes affect the clinical course of HBV infection. Previous studies have shown that miRNA-146a rs2910164 polymorphism can be associated with the pathogenesis of liver diseases such as hepatocellular carcinoma. The present study investigated the association between miRNA-146a rs2910164 polymorphism and susceptibility to HBV infection in an Iranian population. The study comprised 266 patients with chronic HBV infection, 172 patients with spontaneous viral clearance (SVC) after acute HBV infection, and 266 healthy control adjusted for sex and age. The genotyping of the miRNA-146a rs2910164 polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Our data revealed that GG genotype and G allele of miRNA-146a rs2910164 SNP is dominated (P < 0.001) in patients with chronic HBV infection (Odds ratio [OR] = 3.92; 95% confidence interval [CI] = 2.1-7.32). miRNA-146a rs2910164 polymorphism showed a statistically significant association (P < 0.001) between CC genotype and allele C with SVC (OR = 2.92; 95% CI = 1.56-546). Our findings suggest miRNA-146a SNP (C/G) in our population may be associated with the susceptibility to HBV infection and CC genotype is associated with SVC. Also, the GG genotype and G allele at miRNA-146a rs2910164 is associated with chronic HBV infection in our population.

Gambogic Acid Inhibits Melanoma through Regulation of miR-199a-3p/ZEB1 Signalling

Malignant melanoma is an aggressive form of cancer which is highly resistant to chemotherapy. We have previously found that gambogic acid (GA), a kind of polyprenylated xanthone, exhibits an antitumour role in melanoma. The study was designed to investigate novel mechanisms of the antitumour effect of GA in melanoma cells and implanted nude mice. Gambogic acid significantly decreased cell viability, increased apoptosis and reduced migration and invasion in A375 cells. In addition, cisplatin-induced cytotoxicity in both A375 and A375/CDDP cells was increased by GA. The expression of miR-199a-3p was increased by GA in A375 cells and implanted tumours, and inhibition of miR-199a-3p significantly prevented GA-induced effect on cell viability, apoptosis, migration, invasion and cisplatin sensitivity in A375 cells. miR-199a-3p mimics reduced tumour weight and volume in vivo and decreased cell viability, increased apoptosis and reduced migration and invasion in vitro. miR-199a-3p expression was decreased in melanoma tissues and cells, as compared with their controls. miR-199a-3p possessed a potential binding site in the 3'-UTR of zinc finger E-box binding homeobox (ZEB1). ZEB1 expression was increased in melanoma tissues and cells, as compared with their controls. ZEB1 and miR-199a-3p expression was negatively correlated in melanoma tissues. The expression of ZEB1 was decreased by GA in A375 cells and implanted tumours, and up-regulation of ZEB1 significantly prevented GA-induced effect on cell viability, apoptosis, migration, invasion and cisplatin sensitivity. Down-regulation of ZEB1 reduced tumour weight and volume in vivo and decreased cell viability, increased apoptosis and reduced migration and invasion in vitro. We identified the important roles of miR-199a-3p and ZEB1 in melanoma and elucidated the tumour suppressor function of miR-199a-3p through inhibition of ZEB1. The results highlight the importance of miR-199a-3p-ZEB1 signalling in antitumour effect of GA in malignant melanoma and provide novel targets for the chemotherapy of melanoma.

Astemizole promotes the anti-tumor effect of vitamin D through inhibiting miR-125a-5p-meidated regulation of VDR in HCC

Hepatocellular carcinoma (HCC) accounts for the fifth most common cancer worldwide. Vitamin D and antihistamines have been shown to play an anti-tumor role in various tumors. In the present study, we ought to investigate the synergistic effect of astemizole and Vitamin D in HCC cells. We showed that astemizole enhanced the anti-tumor effect of Vitamin D in HCC both in vitro and in vivo. Astemizole enhanced Vitamin D-induced decrease of cell viability and proliferation, increase of apoptosis, decrease of cell migration and invasion in HCC cells in vitro and decrease of tumor number, mass and incidence in HCC in vivo. Astemizole increased VDR expression both in HCC cells in vitro and in tumor tissues in vivo. Downregulation of VDR significantly inhibited the synergistic effect of Vitamin D and astemizole on HCC cell viability, proliferation, apoptosis, migration and invasion. Bioinformatics analysis identified that miR-125a-5p had a putative binding site in the 3'-UTR of VDR. miR-125a-5p mimics inhibited astemizole-induced increase of VDR and enhancement of the anti-tumor effect of Vitamin D in HCC. Reporter gene assay has confirmed that VDR was regulated by miR-125a-5p. miR-125a-5p inhibitors increased VDR expression and decreased cell viability and proliferation in HCC cells. Moreover, VDR and miR-125a-5p expression in tumor tissues in HCC patients were negatively correlated. We identified that inhibition of miR-125a-5p and subsequent upregulation of VDR was involved in astemizole-induced enhancement of the anti-tumor effect of Vitamin D in HCC. These results highlight the importance of combined treatment of astemizole and Vitamin D and provide novel insights into the role of miR-125a-5p-VDR signaling in HCC.

Non-coding RNA in cystic fibrosis

Non-coding RNAs (ncRNAs) are an abundant class of RNAs that include small ncRNAs, long non-coding RNAs (lncRNA) and pseudogenes. The human ncRNA atlas includes thousands of these specialised RNA molecules that are further subcategorised based on their size or function. Two of the more well-known and widely studied ncRNA species are microRNAs (miRNAs) and lncRNAs. These are regulatory RNAs and their altered expression has been implicated in the pathogenesis of a variety of human diseases. Failure to express a functional cystic fibrosis (CF) transmembrane receptor (CFTR) chloride ion channel in epithelial cells underpins CF. Secondary to the CFTR defect, it is known that other pathways can be altered and these may contribute to the pathophysiology of CF lung disease in particular. For example, quantitative alterations in expression of some ncRNAs are associated with CF. In recent years, there has been a series of published studies exploring ncRNA expression and function in CF. The majority have focussed principally on miRNAs, with just a handful of reports to date on lncRNAs. The present study reviews what is currently known about ncRNA expression and function in CF, and discusses the possibility of applying this knowledge to the clinical management of CF in the near future.

miR‑367 enhances the proliferation and invasion of cutaneous malignant melanoma by regulating phosphatase and tensin homolog expression

Melanoma presents a serious threat to human health but the underlying mechanisms have not been fully identified. Increasing evidence indicates that microRNAs exert a significant influence on the tumorigenesis and metastasis of different types of cancer. The present study aimed to identify the role of microRNA (miR)‑367 in the initiation and progression of melanoma and investigate its potential target. A total of 50 melanoma samples and 25 benign nevi tissues were used in the present study. Reverse transcription‑quantitative polymerase chain reaction and western blot analysis were performed to determine the expression of mRNA and protein, respectively. Cell proliferation and invasion were assessed by CCK‑8, wound healing and Transwell assays. A proposed target mRNA of miR‑367 was determined using a luciferase reporter assay and an in vivo xenograft model was used to evaluate the function of miR‑367 in the progression of melanoma. It was revealed that miR‑367 was overexpressed in melanoma tissues and cell lines. The miR‑367 level in tumor tissues was positively correlated with tumor thickness, tumor stage, lymph node involvement, distant metastasis and the patient survival rate. A high miR‑367 level was observed to enhance the growth, migration and invasion of melanoma cells. Conversely, low miR‑367 levels suppressed the proliferation and invasion of melanoma cells. Furthermore, miR‑367 was revealed to bind directly to phosphatase and tensin homolog (PTEN) mRNA and regulate the expression of the PTEN protein. miR‑367 markedly increased the growth and invasion of melanoma cells, whereas the cotransfection of PTEN vectors limited the promoting function of miR‑367 in the proliferation and invasion of A375 cells. The upregulation of miR‑367 promoted tumor growth in vivo. In conclusion, the results revealed that miR‑367 serves a positive role in the development of melanoma and may be an important target for the treatment of cutaneous melanoma.

Associations of miR-605 rs2043556 polymorphism with the susceptibility and overall survival of lung cancer in Chinese non-smoking females

The effects of miR-605 rs2043556 single nucleotide polymorphism (SNP) on the risk and prognosis of lung cancer are unclear. This study investigated the relationships between miR-605 rs2043556 and the susceptibility and overall survival (OS) of lung cancer in Chinese non-smoking females. This hospital-based case-control study included 450 cases and 450 controls. Also, a prospective cohort study was carried out, and the patients were followed up until February 29th, 2016. There were 334 patients with prognostic information. Odds ratio and hazard ratio (HR) and their 95% confidence intervals (CIs) were calculated, respectively. In squamous cell carcinomas (SqCC) patients, homozygous GG genotype carriers had a 2.157-fold elevated risk of lung cancer compared with homozygous AA genotype carriers after adjusting age (95% CI = 1.029-4.524, P = 0.042). After adjusting age, pathological type, clinical stage, chemotherapy and surgery, only a marginal significance was observed among the patients with GG genotype, who had a longer OS than those with AA genotype (HR = 0.632, 95% CI = 0.398-1.003, P = 0.051). For patients younger than 60 years, those containing GG genotype was independently associated with OS (HR = 0.511, 95% CI = 0.268-0.977, P = 0.042). Patients with adenocarcinomas containing GG genotype was independently associated with OS (HR = 0.530, 95% CI = 0.312-0.898, P = 0.018). MiR-605 rs2043556 polymorphism could be associated with the susceptibility of SqCC in northeast Chinese non-smoking females. Age and pathological type might have the potential to modify the association between miR-605 rs2043556 and the OS of non-smoking female lung cancer patients.

Cross-talk of MicroRNA and hydrogen sulfide: A novel therapeutic approach for bone diseases

Bone homeostasis requires a balance between the bone formation of osteoblasts and bone resorption of osteoclasts to maintain ideal bone mass and bone quality. An imbalance in bone remodeling processes results in bone metabolic disorders such as osteoporosis. Hydrogen sulfide (H₂S), a gasotransmitter, has attracted the focus of many researchers due to its multiple physiological functions. It has been implicated in anti-inflammatory, vasodilatory, angiogenic, cytoprotective, anti-oxidative and anti-apoptotic mechanisms. H₂S has also been shown to exert osteoprotective activity through its anti-inflammatory and anti-oxidative effects. However, the underlying molecular mechanisms by which H₂S mitigates bone diseases are not completely understood. Experimental evidence suggests that H₂S may regulate signaling pathways by directly influencing a gene in the cascade or interacting with some other gasotransmitter (carbon monoxide or nitric oxide) or both. MicroRNAs (miRNAs) are short non-coding RNAs which regulate gene expression by targeting, binding and suppressing mRNAs; thus controlling cell fate. Certainly, bone remodeling is also regulated by miRNAs expression and has been reported in many studies. MicroRNAs also regulate H₂S biosynthesis. The inter-regulation of microRNAs and H₂S opens a new possibility for exploring the H₂S-microRNA crosstalk in bone diseases. However, the relationship between miRNAs, bone development, and H₂S is still not well explained. This review focuses on miRNAs and their roles in regulating bone remodeling and possible mechanisms behind H₂S mediated bone loss inhibition, H₂S-miRNAs crosstalk in relation to the pathophysiology of bone remodeling, and future perspectives for miRNA-H₂S as a therapeutic agent for bone diseases.