miR-34a inhibits the migration and invasion of esophageal squamous cell carcinoma by targeting Yin Yang-1

MicroRNA-34 Family in Cancers: Role, Mechanism, and Therapeutic Potential

MicroRNA (miRNA) are small noncoding RNAs that play vital roles in post-transcriptional gene regulation by inhibiting mRNA translation or promoting mRNA degradation. The dysregulation of miRNA has been implicated in numerous human diseases, including cancers. miR-34 family members (miR-34s), including miR-34a, miR-34b, and miR-34c, have emerged as the most extensively studied tumor-suppressive miRNAs. In this comprehensive review, we aim to provide an overview of the major signaling pathways and gene networks regulated by miR-34s in various cancers and highlight the critical tumor suppressor role of miR-34s. Furthermore, we will discuss the potential of using miR-34 mimics as a novel therapeutic approach against cancer, while also addressing the challenges associated with their development and delivery. It is anticipated that gaining a deeper understanding of the functions and mechanisms of miR-34s in cancer will greatly contribute to the development of effective miR-34-based cancer therapeutics.

Targeting Transcription Factor YY1 for Cancer Treatment: Current Strategies and Future Directions

Cancer represents a significant and persistent global health burden, with its impact underscored by its prevalence and devastating consequences. Whereas numerous oncogenes could contribute to cancer development, a group of transcription factors (TFs) are overactive in the majority of tumors. Targeting these TFs may also combat the downstream oncogenes activated by the TFs, making them attractive potential targets for effective antitumor therapeutic strategy. One such TF is yin yang 1 (YY1), which plays crucial roles in the development and progression of various tumors. In preclinical studies, YY1 inhibition has shown efficacy in inhibiting tumor growth, promoting apoptosis, and sensitizing tumor cells to chemotherapy. Recent studies have also revealed the potential of combining YY1 inhibition with immunotherapy for enhanced antitumor effects. However, clinical translation of YY1-targeted therapy still faces challenges in drug specificity and delivery. This review provides an overview of YY1 biology, its role in tumor development and progression, as well as the strategies explored for YY1-targeted therapy, with a focus on their clinical implications, including those using small molecule inhibitors, RNA interference, and gene editing techniques. Finally, we discuss the challenges and current limitations of targeting YY1 and the need for further research in this area.

YY1 accelerates oral squamous cell carcinoma progression through long non-coding RNA Kcnq1ot1/microRNA-506-3p/SYPL1 axis

OBJECTIVE

Ying Yang1 (YY1) has already been discussed in oral squamous cell carcinoma (OSCC), but the knowledge about its mediation on long non-coding RNA KCNQ1 overlapping transcript 1/microRNA-506-3p/synaptophysin like 1 (Kcnq1ot/miR-506-3p/SYPL1) axis in OSCC is still in its infancy. Hence, this article aims to explain the mechanism of YY1/Kcnq1ot1/miR-506-3p/SYPL1 axis in OSCC development.

METHODS

YY1, Kcnq1ot1, miR-506-3p and SYPL1 expression levels were determined in OSCC tissues. The potential relation among YY1, Kcnq1ot1, miR-506-3p and SYPL1 was explored. Cell progression was observed to figure out the actions of depleted YY1, Kcnq1ot1 and SYPL1 and restored miR-506-3p in OSCC. OSCC tumorigenic ability in mice was examined.

RESULTS

Elevated YY1, Kcnq1ot1 and SYPL1 and reduced miR-506-3p were manifested in OSCC. YY1 promoted Kcnq1ot1 transcription and up-regulated Kcnq1ot1 expression, thereby promoting OSCC cell procession. Silencing Kcnq1ot1 or elevating miR-506-3p delayed OSCC cell progression and silencing Kcnq1ot1 impeded tumorigenic ability of OSCC cells in mice. YY1-mediated Kcnq1ot1 sponged miR-506-3p to target SYPL1.

CONCLUSION

YY1 promotes OSCC cell progression via up-regulating Kcnq1ot1 to sponge miR-506-3p to elevate SYPL1, guiding a novel way to treat OSCC.

Tumor Suppressor microRNAs in Gastrointestinal Cancers: A Mini-Review

BACKGROUND

Gastrointestinal (GI) cancer is associated with a group of cancers affecting the organs in the GI tract, with a high incidence and mortality rate. This type of cancer development involves a series of molecular events that arise by the dysregulation of gene expressions and microRNAs (miRNAs).

OBJECTIVES

This mini-review focuses on elucidating the mechanism of tumor suppressor miRNA-mediated oncogenic gene silencing, which may contribute to a better understanding of miRNA-mediated gene expression regulation of cell cycle, proliferation, invasion, and apoptosis in GI cancers. In this review, the biological significance of tumor suppressor miRNAs involved in gastrointestinal cancers is briefly explained.

METHODS

The articles were searched with the keywords 'miRNA', 'gastrointestinal cancers', 'esophageal cancer', 'gastric cancer', 'colorectal cancer', 'pancreatic cancer', 'liver cancer', and 'gall bladder cancer' from the Google Scholar and PubMed databases. A total of 71 research and review articles have been collected and referred for this study.

RESULTS

This review summarises recent research enhancing the effectiveness of miRNAs as novel prognostic, diagnostic, and therapeutic markers for GI cancer treatment strategies. The expression pattern of various miRNAs has been dysregulated in GI cancers, which are associated with proliferation, cell cycle regulation, apoptosis, migration, and invasion.

CONCLUSION

The role of tumor suppressor miRNAs in the negative regulation of oncogenic gene expression was thoroughly explained in this review. Its potential role as a microRNA therapeutic candidate is also discussed. Profiling and regulating tumor suppressor miRNA expression in gastrointestinal cancers using miRNA mimics could be used as a prognostic, diagnostic, and therapeutic marker, as well as an elucidating molecular therapeutic approach to tumor suppression.

Regulation of ferroptosis by noncoding RNAs: a novel promise treatment in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a highly prevalent tumor that requires extensive research. Ferroptosis is a unique cell death modality driven by iron-dependent phospholipid peroxidation manifested as an accumulation of lipid-reactive oxygen species. With further understanding of noncoding RNAs (ncRNAs), numerous studies have demonstrated an important regulatory role of ncRNAs in ESCC through ferroptosis, including microRNAs, long ncRNAs, and circular RNAs. These ncRNAs influence the expression of the target gene to regulate ESCC progression by involving the ferroptosis signaling pathway. However, the specific regulatory mechanism of ncRNAs on ferroptosis in ESCC remains largely unknown. This review summarized the current knowledge on the relation between ferroptosis regulators, such as glutathione synthesis/metabolism, Keap1/Nfr2, and p53, by ncRNAs and ESCC. This review also proposed the possible therapeutic approaches for ncRNAs targeting ferroptosis in ESCC. This is the latest and most effective summary of recent research achievements of ncRNAs on ferroptosis in ESCC. These ncRNAs based on ferroptosis merit further investigation in preclinical research of ESCC.

A Boolean Model of the Proliferative Role of the lncRNA XIST in Non-Small Cell Lung Cancer Cells

The long non-coding RNA X inactivate-specific transcript (lncRNA XIST) has been verified as an oncogenic gene in non-small cell lung cancer (NSCLC) whose regulatory role is largely unknown. The important tumor suppressors, microRNAs: miR-449a and miR-16 are regulated by lncRNA XIST in NSCLC, these miRNAs share numerous common targets and experimental evidence suggests that they synergistically regulate the cell-fate regulation of NSCLC. LncRNA XIST is known to sponge miR-449a and miR-34a, however, the regulatory network connecting all these non-coding RNAs is still unknown. Here we propose a Boolean regulatory network for the G1/S cell cycle checkpoint in NSCLC contemplating the involvement of these non-coding RNAs. Model verification was conducted by comparison with experimental knowledge from NSCLC showing good agreement. The results suggest that miR-449a regulates miR-16 and p21 activity by targeting HDAC1, c-Myc, and the lncRNA XIST. Furthermore, our circuit perturbation simulations show that five circuits are involved in cell fate determination between senescence and apoptosis. The model thus allows pinpointing the direct cell fate mechanisms of NSCLC. Therefore, our results support that lncRNA XIST is an attractive target of drug development in tumor growth and aggressive proliferation of NSCLC, and promising results can be achieved through tumor suppressor miRNAs.

Upregulation of Yin-Yang-1 Associates with Proliferation and Glutamine Metabolism in Esophageal Carcinoma

Objective

To investigate the expression of Yin-Yang-1 (YY1) in esophageal carcinoma (ESCA) and its effect on glutamine metabolism in ESCA.

Methods

The expression and roles of YY1 in ESCA were investigated using a series of bioinformatics databases and tools. The expression of YY1 between ESCA tissues with the corresponding adjacent tissues was validated using real-time PCR, western blot, and immunohistochemical staining method. Furthermore, the effects of YY1 on ESCC cell proliferation and migration were examined. The correlation between the YY1 and glutamine metabolism was evaluated by western blot.

Results

YY1 gene was highly conserved in evolution and upregulated in ESCA tissues and ESCC cell lines (ECA109 and TE-1). In addition, YY1 may affect the level of immune cell infiltration and promote tumor cell immune escape. Functional enrichment analysis found that YY1 involved in many biological processes, such as cell division and glutathione and glutamine metabolism. After siRNA knockdown of YY1 in ECA109 and TE-1, the proliferation and the migration of ECA109 and TE-1 were suppressed. The glutamine consumption and glutamate production were significantly decreased. The protein expression of alanine-, serine-, cysteine-preferring transporter 2 (ASCT2), glutaminase (GLS), and glutamate dehydrogenase (GLUD1) was significantly downregulated.

Conclusion

YY1 is highly expressed in ESCA and may promote glutamine metabolism of ESCC cells, indicating it may be as a diagnostic biomarker for ESCA.

Roles of microRNAs in tumorigenesis and metastasis of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the major subtype of esophageal cancer that is prevalent in Eastern Asia. Despite recent advances in therapy, the outcome of ESCC patients is still dismal. MicroRNAs (miRNAs) are non-coding RNAs which can negatively modulate gene expression at the post-transcriptional level. The involvement and roles of miRNAs have become one of the hot topics of cancer research in recent years. In ESCC, genetic variations within miRNA coding genes were found to have distinct epidemiological significance in different populations. Dysregulated expression of several miRNAs was reported to be associated with therapeutic response. Functionally, miRNAs can act either in an oncogenic or a tumor-suppressive manner during tumorigenesis of ESCC by interrupting signaling pathways associated with cell proliferation, metabolism, cancer stemness, and resistance to chemo- or radiotherapy. Moreover, miRNAs modulate metastasis of ESCC by targeting genes that regulate cytoskeleton dynamics, extracellular matrix remodeling, epithelial-mesenchymal transition, and tumor microenvironment. Most importantly, mounting evidence suggests that inhibiting oncogenic miRNAs or restoring the loss of tumor-suppressive miRNAs has therapeutic potential in the treatment of ESCC. Here, we review and discuss recent studies on the significance, biological functions, and therapeutic potential of miRNAs in tumorigenesis and metastasis of ESCC.

The comprehensive landscape of miR-34a in cancer research

MicroRNA-34 (miR-34) plays central roles in human diseases, especially cancers. Inactivation of miR-34 is detected in cancer cell lines and tumor tissues versus normal controls, implying its potential tumor-suppressive effect. Clinically, miR-34 has been identified as promising prognostic indicators for various cancers. In fact, members of the miR-34 family, especially miR-34a, have been convincingly proved to affect almost the whole cancer progression process. Here, a total of 512 (miR-34a, 10/21), 85 (miR-34b, 10/16), and 114 (miR-34c, 10/14) putative targets of miR-34a/b/c are predicted by at least ten miRNA databases, respectively. These targets are further analyzed in gene ontology (GO), KEGG pathway, and the Reactome pathway dataset. The results suggest their involvement in the regulation of signal transduction, macromolecule metabolism, and protein modification. Also, the targets are implicated in critical signaling pathways, such as MAPK, Notch, Wnt, PI3K/AKT, p53, and Ras, as well as apoptosis, cell cycle, and EMT-related pathways. Moreover, the upstream regulators of miR-34a, mainly including transcription factors (TFs), lncRNAs, and DNA methylation, will be summarized. Meanwhile, the potential TF upstream of miR-34a/b/c will be predicted by PROMO, JASPAR, Animal TFDB 3.0, and GeneCard databases. Notably, miR-34a is an attractive target for certain cancers. In fact, miR-34a-based systemic delivery combined with chemotherapy or radiotherapy can more effectively control tumor progression. Collectively, this review will provide a panorama for miR-34a in cancer research.

The Association of microRNA-34a With High Incidence and Metastasis of Lung Cancer in Gejiu and Xuanwei Yunnan

The incidence and associated mortality of lung cancer in tin miners in Gejiu County and farmers in Xuanwei Country, Yunnan Province have been very high in the world. Current published literatures on the molecular mechanisms of lung cancer initiation and progression in Gejiu and Xuanwei County are still controversial. Studies confirmed that microRNA-34a (miR-34a) functioned as a vital tumor suppressor in tumorigenesis and progression. However, the role and precise mechanisms of miR-34a and its regulatory gene network in initiation and progression of lung cancer in Gejiu and Xuanwei County, Yunnan Province, have not been elucidated. In the current study, we first found that miR-34a was downregulated in Gejiu lung squamous carcinoma YTMLC-90, Xuanwei lung adenocarcinoma XWLC-05, and other non-small cell lung carcinoma (NSCLC) cell lines, and miR-34a overexpression inhibited cell proliferation, migration and invasion, as well as induced cell apoptosis in YTMLC-90 and XWLC-05 cells. Our findings revealed that miR-34a is critical and cannot be considered as the area-specific non-coding RNA in initiation and progression of lung cancer in Gejiu and Xuanwei County. Next we revealed that miR-34a overexpression suppressed lung cancer growth and metastasis partially via increasing PTEN but reducing CDK6 expression that might lead to subsequent inactivation of PI3K/AKT pathway. Furthermore, our findings demonstrated that YY1 functioned as a tumor suppressor gene in initiation and progression of lung cancer in Gejiu and Xuanwei County. In conclusion, our findings in the study confirmed that miR-34a overexpression could simultaneously suppress tumor growth and metastasis and play a vital role in tumorigenesis and progression of NSCLC via increasing PTEN and YY1 expression, but decreasing CDK6. Most interestingly, our findings also raised doubts about the current ideas about these area-specific diseases.

MicroRNA-34 expression in gingival crevicular fluid correlated with orthodontic tooth movement

OBJECTIVES

To explore the expression of miR-34a and its effect on expression of matrix metalloproteinases (MMPs) during orthodontic tooth movement (OTM).

MATERIALS AND METHODS

Twenty patients, age 12-18 years old, who underwent orthodontic treatment were enrolled. The expression of miR-34a and MMPs (MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, and MMP-14) were detected in gingival crevicular fluid by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction at different time points. The miR-34a mimics or inhibitors were transfected into human periodontal ligament (hPDL) cells, and the MMP expression was measured by ELISA.

RESULTS

The miR-34 expression in GCF on both the tension and pressure sides after orthodontic treatment were significantly downregulated, while the levels of MMPs were significantly upregulated compared with baseline level. The levels of miR-34 and MMPs returned to baseline level 3 months after orthodontic treatment. The expression of miR-34 was negatively correlated with the expression of MMP-2, MMP-9, and MMP-14. After transfection with miR-34, the MMP-2, MMP-9, and MMP-14 expression by hPDL cells were significantly downregulated compared with miR-control and miR-34 inhibitor.

CONCLUSIONS

Downregulated miR-34 expression was positively correlated with MMP-2, MMP-9, and MMP-14 expression. The miR-34a transfection into hPDL cells inhibited expression of MMPs. The results suggest that miR-34a is involved in expression of MMPs during OTM.

Transcriptional Factor Yin Yang 1 Promotes the Stemness of Breast Cancer Cells by Suppressing miR-873-5p Transcriptional Activity

Transcription factor Yin Yang 1 (YY1) is upregulated in multiple tumors and plays essential roles in tumor proliferation and metastasis. However, the function of YY1 in breast cancer stemness remains unclear. Herein, we found that YY1 expression was negatively correlated with the overall survival and relapse-free survival of breast cancer patients and positively correlated with the expression of stemness markers in breast cancer. Overexpression of YY1 increased the expression of stemness markers, elevated CD44⁺CD24⁻ cell sub-population, and enhanced the capacity of cell spheroid formation and tumor-initiation. In contrast, YY1 knockdown exhibited the opposite effects. Mechanistically, YY1 decreased microRNA-873-5p (miR-873-5p) level by recruiting histone deacetylase 4 (HDAC4) and HDAC9 to miR-873-5p promoter and thus increasing the deacetylation level of miR-873-5p promoter. Sequentially, YY1 activated the downstream PI3K/AKT and ERK1/2 pathways, which have been confirmed to be suppressed by miR-873-5p in our recent work. Moreover, the suppressed effect of YY1/miR-873-5p axis on the stemness of breast cancer cells was partially dependent on PI3K/AKT and ERK1/2 pathways. Finally, it was found that the YY1/miR-873-5p axis is involved in the chemoresistance of breast cancer cells. Our study defines a novel YY1/miR-873-5p axis responsible for the stemness of breast cancer cells.

A Systemic Review on the Regulatory Roles of miR-34a in Gastrointestinal Cancer

MicroRNAs (miRNAs) are a class of endogenous non-coding single-stranded small-molecule RNAs that regulate gene expression by repressing target messenger RNA (mRNA) translation or degrading mRNA. miR-34a is one of the most important miRNAs participating in various physiological and pathological processes. miR-34a is abnormally expressed in a variety of tumors. The roles of miR-34a in gastrointestinal cancer (GIC) draw lots of attention. Numerous studies have demonstrated that dysregulated miR-34a is closely related to the proliferation, differentiation, migration, and invasion of tumor cells, as well as the diagnosis, prognosis, treatment, and chemo-resistance of tumors. Thus, we systematically reviewed the abnormal expression and regulatory roles of miR-34a in GICs including esophageal cancer (EC), gastric cancer (GC), colorectal cancer (CRC), hepatocellular carcinoma (HCC), pancreatic cancer (PC), and gallbladder cancer (GBC). It may provide a profile of versatile roles of miR-34a in GICs.

The biological implications of Yin Yang 1 in the hallmarks of cancer

Tumorigenesis is a multistep process characterized by the acquisition of genetic and epigenetic alterations. During the course of malignancy development, tumor cells acquire several features that allow them to survive and adapt to the stress-related conditions of the tumor microenvironment. These properties, which are known as hallmarks of cancer, include uncontrolled cell proliferation, metabolic reprogramming, tumor angiogenesis, metastasis, and immune system evasion. Zinc-finger protein Yin Yang 1 (YY1) regulates numerous genes involved in cell death, cell cycle, cellular metabolism, and inflammatory response. YY1 is highly expressed in many cancers, whereby it is associated with cell proliferation, survival, and metabolic reprogramming. Furthermore, recent studies also have demonstrated the important role of YY1-related non-coding RNAs in acquiring cancer-specific characteristics. Therefore, these YY1-related non-coding RNAs are also crucial for YY1-mediated tumorigenesis. Herein, we summarize recent progress with respect to YY1 and its biological implications in the context of hallmarks of cancer.

MiR-29c-3p Suppresses the Migration, Invasion and Cell Cycle in Esophageal Carcinoma via CCNA2/p53 Axis

Objective

In the present study, we tried to describe the role of miR-29c-3p in esophageal carcinoma (EC) and the relationship of miR-29c-3p with CCNA2 as well as cell cycle, accordingly revealing the potential molecular mechanism across cell proliferation, migration and invasion.

Methods

Expression profiles of EC miRNAs and matched clinical data were accessed from TCGA database for differential and survival analyses. Bioinformatics databases were employed to predict the downstream targets of the potential miRNA, and enrichment analysis was performed on the miRNA and corresponding target gene using GSEA software. qRT-PCR was conducted to detect the expression levels of miR-29c-3p and CCNA2 mRNA in EC tissues and cells, and Western blot was performed for the examination of CCNA2, CDK1 and p53 protein levels. Subsequently, cells were harvested for MTT, Transwell as well as flow cytometry assays to examine cell viability, migration, invasion and cell cycle. Dual-luciferase reporter gene assay and RIP were carried out to further investigate and verify the targeted relationship between miR-29c-3p and CCNA2.

Results

MiR-29c-3p was shown to be significantly down-regulated in EC tissues and able to predict poor prognosis. CCNA2 was found to be a downstream target of miR-29c-3p and mainly enriched in cell cycle and p53 signaling pathway, whereas miR-29c-3p was remarkably activated in cell cycle. MiR-29c-3p overexpression inhibited cell proliferation, migration and invasion, as well as arrested cells in G0/G1 phase. As suggested by dual-luciferase reporter gene assay and RIP, CCNA2 was under the regulation of miR-29c-3p, and the negative correlation between the two genes was verified. Silencing CCNA2 could suppress cell proliferation, migration and invasion, as well as activate p53 pathway, even was seen to reverse the inhibitory effect of PFTβ on p53. Besides, in the presence of low miR-29c-3p, CCNA2 was up-regulated while p53 was simultaneously inhibited, resulting in the promotion of cell migration, invasion and cell cycle arrest.

Conclusion

MiR-29c-3p plays a regulatory role in EC tumorigenesis and development. MiR-29c-3p can target CCNA2 to mediate p53 signaling pathway, finally attributing to the inhibition of cell proliferation, migration and invasion, and making cells arrest in G0/G1 phase.

The Interplay of MicroRNA-34a, LGR4, EMT-Associated Factors, and MMP2 in Regulating Uveal Melanoma Cells

Purpose

MicroRNA-34a (miR-34a) has been implicated in many biological processes. It is downregulated in uveal melanoma, and introduction of miR-34a inhibits the proliferation and migration of uveal melanoma cells. Leucine-rich repeat-containing G protein-coupled receptor 4 (LGR4) is a novel target of miR-34a identified first in retinal pigment epithelial cells. In this study, we sought to evaluate the interaction of miR-34a and LGR4 in uveal melanoma and its downstream mechanisms.

Methods

The expression of LGR4, epithelial-mesenchymal transition (EMT)-associated factors, and matrix metalloproteinase 2 (MMP2) in uveal melanoma cells was assessed by immunoblotting and immunofluorescence analysis. MicroRNA-34a mimic molecules, LGR4 small interfering RNA (siRNA), or MMP2-specific siRNA were transiently transfected into uveal melanoma cells. In vitro scratch and Transwell assays were used to evaluate the migratory and invasive potential of the resultant uveal melanoma cells.

Results

LGR4 is upregulated in uveal melanoma cells. Introduction of miR-34a significantly decreased the expression level of LGR4. Transfection with miR-34a or knockdown of LGR4 attenuated the aggressiveness of uveal melanoma cells. In addition, there was a decrease in the expression of mesenchymal markers N-cadherin, vimentin, and Snail following miR-34a introduction or knockdown of LGR4. Finally, MMP2 was found to be a downstream effector for miR-34a and LGR4 that regulates the migration and invasion of uveal melanoma cells.

Conclusions

MicroRNA-34a negatively controls LGR4, thereby inhibiting the migration and invasion of uveal melanoma cells. Ultimately, both miR-34a and LGR4 impact the aggressiveness of uveal melanoma with alterations in the markers of the EMT. MMP2 is a downstream effector that influences the metastasis seen with uveal melanoma cells.

Effects of radon on miR-34a-induced apoptosis in human bronchial epithelial BEAS-2B cells

Radon exposure is known to be the second most frequent cause followed by tobacco exposure for lung cancer development. In lung cancer development, microRNAs (miRNAs) play an important role in regulating various target genes associated with this disease. It is well-established that apoptosis is involved in the elimination of cancer cells. However, the mechanisms underlying chronic radon exposure induced miRNAs regulation attributed to result in carcinogenesis and subsequent activation of apoptosis is not completely understood. The aim of this study was thus to examine chronic low level radon exposure on lung miRNAs as a model for carcinogenesis induction and subsequent activation of apoptosis using human bronchial epithelial BEAS-2B cells. Quantitative real-time PCR (qRT-PCR) and flow cytometry were used to determine the miR-34a gene expression and apoptotic rate in BEAS-2B cells. Data demonstrated that chronic radon exposure up-regulated the expressions of miR-34a and enhanced cellular apoptosis in a time-dependent manner. Western blot analysis demonstrated that overexpression of the gene miR-34a enhanced apoptotic rate and elevated proapoptotic Bax protein expression accompanied by decreased protein expressions of antiapoptotic Bcl-2 and PARP-1. It is noteworthy that the apoptotic rate was elevated in BEAS-2B cells transfected with mi-R34a mimic but reduced in mi-R34a inhibitor-transfected cells. Evidence thus indicates that chronic exposure to radon produced up-regulation of miR-34a gene which subsequently enhanced apoptosis in BEAS-2B cells. The observed consequences following chronic radon exposure leading to carcinogenesis appear to involve activation of miR-34a gene.

miR-34a inhibits esophageal squamous cell carcinoma progression via regulation of FOXM1

Downregulation of microRNA-34a (miR-34a) has frequently been observed in esophageal squamous cell carcinoma (ESCC). However, the underlying role and molecular mechanism of miR-34a in ESCC remains largely unknown. In the current study, it was demonstrated that miR-34a was downregulated and forkhead box M1 (FOXM1), a target gene of miR-34a, was upregulated in ESCC tumor tissues. Overexpression of miR-34a decreased FOXM1 mRNA and protein expression in the ESCC cell lines tested (TE-1 and TE-8). Inhibition of miR-34a increased FOXM1 mRNA and protein levels in human esophageal epithelial cells (HEEC). In addition, miR-34a mimics reduced the relative luciferase activity of ESCC cells transfected with FOXM1 3'UTR-WT, but not FOXM1 3'UTR-Mut. The CCK8 assay and scratch wound healing assay showed that overexpression of miR-34a induced inhibition of cell proliferation and cell migration. Additionally, transfection with miR-34a mimics reduced the expression of key genes involved in cell migration (MMP2 and MMP9) in ESCC cells. Thus, the present data demonstrated that miR-34a suppressed ESCC progression by directly targeting FOXM1.

Snail-1 Silencing by siRNA Inhibits Migration of TE-8 Esophageal Cancer Cells Through Downregulation of Metastasis-Related Genes

Purpose: Snail-1 is a transcription factor, which takes part in EMT, a process related to the emergence of invasion and cancer progression. The purpose of this study was to evaluate the effect of Snail-1 silencing on the human esophageal squamous cell carcinoma cell line, namely TE-8, in vitro.

Methods: In this study, transfection of Snail-1 specific siRNA was conducted into TE-8 cells. The relative mRNA expression levels of Snail-1, Vimentin, CXCR4 and MMP-9 and transcription levels of miR-34a and let-7a were investigated by quantitative Real-time PCR. Western blotting was carried out to evaluate the Snail-1 protein level. Migration assay of TE-8 cells was also performed following the presence or absence of Snail-1 specific siRNA. MTT and TUNEL assays were performed to evaluate cell viability after Snail-1 silencing.

Results: It was found that treatment of cancer cells with the Snail-specific siRNA effectively downregulated the expression of Snail-1 in both mRNA and protein levels, and vimentin, CXCR4, and MMP-9 in mRNA level. However, it elevated the transcript levels of miR-34a and let-7a expressions. Furthermore, transfection of cancer cells with the Snail-specific siRNA significantly induced apoptosis in TE8 cells. Moreover, suppression of Snail-1 led to diminished cell migration.

Conclusion: It seems that Snail-specific siRNA can significantly interrupt esophageal cancer cell migration and reduce metastatic-related factors and induce miR-34a and let-7a in vitro. The bottom line is that therapeutic approaches via targeting Snail-1 can be used for ESCC treatment, suggesting that other possible target molecules for ESCC therapy require to be explored.

miR-34a Regulates Multidrug Resistance via Positively Modulating OAZ2 Signaling in Colon Cancer Cells

Although aberrant expression of miR-34a, an essential tumor suppressor miRNA, has been frequently observed in colon cancer (CCa), whether miR-34a can regulate CCa progression by modulating other facets of this malignancy (such as multidrug resistance, MDR) remains unknown. Here, we report for the first time that miR-34a expression was significantly downregulated in clinical CCa samples from oxaliplatin-resistant patients and in experimentally established multidrug-resistant CCa cells. By using histoculture drug response assay, we further confirmed that clinical CCa samples with lower miR-34a expression appeared to be more resistant to chemotherapy. Functionally, ectopic expression of exogenous miR-34a resensitized multidrug-resistant HCT-8/OR cells to oxaliplatin treatment, whereas miR-34a inhibition augmented the oxaliplatin resistance in chemosensitive HCT-8 cells. Mechanistically, miR-34a positively regulated the mRNA stability of the ornithine decarboxylase antizyme 2 (OAZ2) by directly targeting its three prime untranslated region (3′UTR). Consequently, suppression of the expression of miR-34a/OAZ2 signaling by chemotherapeutic agents significantly enhanced the activation of MDR-associated ATP-binding cassette (ABC) transporters and antiapoptosis pathways, thus leading to MDR development in CCa cells. Collectively, our combined analysis reveals a critical role of miR-34a/OAZ2 cascade in conferring a proper cellular response to CCa chemotherapy.

MicroRNA-34a expression levels in serum and intratumoral tissue can predict bone metastasis in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) patients with bone metastasis (BM) suffer from pain and other symptoms that significantly reduce their quality of life. We screened a microRNA (miRNA) microarray to identify potential serum biomarkers for BM in HCC patients. A miRNA microarray was used to screen for BM-related miRNAs in paired serum samples from HCC patients with BM and from HCC patients without BM. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to quantify candidate miRNAs in serum samples from 106 independent HCC patients. Levels of candidate miRNAs in tissue samples from an independent cohort of 296 HCC patients were evaluated by in situ hybridization and intratumoral tissue microarray. The migration and invasion capabilities of HCCLM3 and SMMC-7721 cells were evaluated following treatment with a mimic and an inhibitor of miR-34a. Ninety miRNAs were differentially expressed in sera from HCC patients with BM when compared with sera from non-BM HCC patients (P < 0.05). Only miR-34a and miR-498 had false discovery rates (FDRs) < 0.05. In cohorts of 106 and 296 HCC patients, we found that reduced serum and intratumoral miR-34a expression levels were independent risk factors for developing BM. Migration and invasion experiments indicated that a reverse correlation existed between miR-34a and HCC tumor migration and invasion. This study demonstrates the potential for the use of miR-34a as a serum and intratumoral tissue biomarker for predicting the risk of BM in HCC patients.

The Yin and Yang of YY1 in tumor growth and suppression

Yin Yang-1 (YY1) is a zinc finger protein and member of the GLI-Kruppel family that can activate or inactivate gene expression depending on interacting partners, promoter context and chromatin structure, and may be involved in the transcriptional control of ∼10% of the total mammalian gene set. A growing body of literature indicates that YY1 is overexpressed in multiple cancer types and that increased YY1 levels correlate with poor clinical outcomes in many cancers. However, the role of YY1 in the promotion or suppression of tumor growth remains controversial and its regulatory effects may be tumor cell type dependent at least in experimental systems. The molecular mechanisms responsible for the apparently conflicting roles of YY1 are not yet fully elucidated. This review highlights recent advances in our understanding of regulatory insights involving YY1 function in a range of cancer types. For example, YY1's roles in tumor growth involve stabilization of hypoxia-inducible factor HIF-1α in a p53 independent manner, negative regulation of miR-9 transcription, control of MYCT1 transcription, a novel miR-193a-5p-YY1-APC axis, intracellular ROS and mitochondrial superoxide generation, p53 reduction and EGFR activation, control of genes associated with mitochondrial energy metabolism and miRNA regulatory networks involving miR-7, miR-9, miR-34a, miR-186, miR-381, miR-584-3p and miR-635. On the other hand, tumor suppressor roles of YY1 appear to involve YY1 stimulation of tumor suppressor BRCA1, increased Bax transcription and apoptosis involving cytochrome c release and caspase-3/-7 cleavage, induction of heme oxygenase-1, inhibition of pRb phosphorylation and p21 binding to cyclin D1 and cdk4, reduced expression of long noncoding RNA of SOX2 overlapping transcript, and MUC4/ErbB2/p38/MEF2C-dependent downregulation of MMP-10. YY1 expression is associated with that of cancer stem cell markers SOX2, BMI1 and OCT4 across many cancers suggesting multidynamic regulatory control and groups of cancers with distinct molecular signatures. Greater understanding of the mechanistic roles of YY1 will in turn lead to the development of more specific approaches to modulate YY1 expression and activity with therapeutic potential.

Analysis of microarrays of miR-34a and its identification of prospective target gene signature in hepatocellular carcinoma

BACKGROUND

Currently, some studies have demonstrated that miR-34a could serve as a suppressor of several cancers including hepatocellular carcinoma (HCC). Previously, we discovered that miR-34a was downregulated in HCC and involved in the tumorigenesis and progression of HCC; however, the mechanism remains unclear. The purpose of this study was to estimate the expression of miR-34a in HCC by applying the microarray profiles and analyzing the predicted targets of miR-34a and their related biological pathways of HCC.

METHODS

Gene expression omnibus (GEO) datasets were conducted to identify the difference of miR-34a expression between HCC and corresponding normal tissues and to explore its relationship with HCC clinicopathologic features. The natural language processing (NLP), gene ontology (GO), pathway and network analyses were performed to analyze the genes associated with the carcinogenesis and progression of HCC and the targets of miR-34a predicted in silico. In addition, the integrative analysis was performed to explore the targets of miR-34a which were also relevant to HCC.

RESULTS

The analysis of GEO datasets demonstrated that miR-34a was downregulated in HCC tissues, and no heterogeneity was observed (Std. Mean Difference(SMD) = 0.63, 95% confidence intervals(95%CI):[0.38, 0.88], P < 0.00001; P_{heterogeneity} = 0.08 I² = 41%). However, no association was found between the expression value of miR-34a and any clinicopathologic characteristics. In the NLP analysis of HCC, we obtained 25 significant HCC-associated signaling pathways. Besides, we explored 1000 miR-34a-related genes and 5 significant signaling pathways in which CCND1 and Bcl-2 served as necessary hub genes. In the integrative analysis, we found 61 hub genes and 5 significant pathways, including cell cycle, cytokine-cytokine receptor interaction, notching pathway, p53 pathway and focal adhesion, which proposed the relevant functions of miR-34a in HCC.

CONCLUSION

Our results may lead researchers to understand the molecular mechanism of miR-34a in the diagnosis, prognosis and therapy of HCC. Therefore, the interaction between miR-34a and its targets may promise better prediction and treatment for HCC. And the experiments in vivo and vitro will be conducted by our group to identify the specific mechanism of miR-34a in the progress and deterioration of HCC.

MicroRNA-34a suppresses invasion and metastatic in esophageal squamous cell carcinoma by regulating CD44

In human esophageal squamous cell carcinoma (ESCC), miR-34a was downregulated and could inhibit in vitro cell proliferation and migration. However, the underlying mechanism was not clear yet. The expression levels of mRNA and protein were detected by quantitative real-time PCR or western blotting, respectively. MiR-34a was knocked down or overexpressed and transfected into human ESCC cell lines ECA109 and TE-13, respectively. Cell migration and wound healing assays were used to examine the effect on migration and invasion in vitro. Animal models were used to examine the role of miR-34a in metastasis in vivo. Luciferase assay was carried out to validate the potential target of miR-34a. CD44 was upregulated and miR-34a was downregulated in ESCC tissues and cell lines. The linear regression analysis showed that CD44 expression was negatively correlated with the level of miR-34a. Luciferase assay showed that miR-34a interacted with a putative binding site in the CD44 3'UTR. MiR-34a was found to negatively regulate the expression of CD44. In vitro experiment showed that miR-34a overexpression inhibited ESCC cell invasion and migration; whereas miR-34a knockdown showed reversed results. MiR-34a also inhibited esophagus tumor growth and metastasis in vivo; whereas miR-34a knockdown showed reversed results. Finally, we found that CD44 knockdown reversed the effects of miR-34a knockdown on ESCC cell invasion and migration in vitro. MiRNA-34a suppresses invasion and metastatic in ESCC by regulating CD44.

MicroRNA-34a functions as a tumor suppressor by directly targeting oncogenic PLCE1 in Kazakh esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the frequent malignant tumors with poor prognosis worldwide. Identifying the prognostic biomarkers and potential mechanisms of such tumors has attracted increasing interest in esophageal cancer biology. Our previous study showed that phospholipase C elipson 1 (PLCE1) expression is up-regulated and associated with disease progression in esophageal carcinoma. MicroRNAs (miRNAs) play vital roles in regulating its target gene expression. However, studies on miRNA-regulated PLCE1 expression and its cellular function are still very few. We found that miR-34a is significantly expressed lower in ESCC tissues. We further showed that PLCE1 is a direct functional target gene of miR-34a, and the functional roles of miR-34a in ESCC cell lines in vitro were also determined through gain- and loss-of-function analyses. Results revealed that miR-34a functions as a tumor suppressor by inhibiting the proliferation, migration, and EMT phenotype, as well as promoting apoptosis of ESCC cell lines. Moreover, PLCE1 is overexpressed in ESCC tumors and promotes tumorigenicity in vivo and vitro. PLCE1 expression is negatively correlated with miR-34a profiles in ESCC tissues. Our data suggest that miR-34a exerts its anti-cancer function by suppressing PLCE1. The newly identified miR-34a/PLCE1 axis partially illustrates the molecular mechanism of ESCC metastasis and represents a new candidate therapeutic target for ESCC treatment.

MiR-34a and miR-206 act as novel prognostic and therapy biomarkers in cervical cancer

Background

Recent evidence indicated that the aberrant expression of microRNA plays a crucial role in the development of cervical cancer. The overall shorter survival was strongly related to the abnormal expression of microRNA-34a (miR-34a) and microRNA-206 (miR-206), which target B cell lymphoma-2(Bcl2) and c-Met. Hepatocyte growth factor (HGF)/c-Met pathway is related to the occurrence, development and prognosis of cervical cancer, and c-Met is significantly overexpressed in cervical squamous cell carcinoma. Bcl2 is also considered to be a promising target for developing novel anticancer treatments.

Methods

In this study, we detect the expression of miR-34a and miR-206 in the cervical cancer tissue through quantificational real-time polymerase chain reaction (qRT-PCR) assay, and the expression of Bcl2 and c-Met from cervical cancer tissue were detected by immunohistochemistry.

Results

The expression of miR-34a and miR-206 were down-regulated in the cervical cancer tissue through qRT-PCR assay. As target genes of miR-34a and miR-206, Bcl2 and c-Met were up-regulated in cervical cancer tissues through qRT-PCR assay and immunohistochemistry. Kaplan–Meier and log-rank analysis revealed that down-regulated expression of miR-34a and miR-206 were strongly related to shorter overall survival. Multivariate Cox proportional hazards model for all variables that were statistically significant in the univariate analysis demonstrated that miR-34a (P = 0.038) and miR-206 (P = 0.008) might be independent prognostic factors for overall survival of patients suffering from cervical cancer.

Conclusions

The up-regulation of Bcl2 and c-Met promotes the cervical cancer’s progress, and the expression of miR-34a and miR-206 significantly correlated with the progression and prognosis in cervical cancer. All of these suggested that miR-34a and miR-206 might be the novel prognostic and therapy tools in cervical cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-017-0431-9) contains supplementary material, which is available to authorized users.

Tumor suppressor microRNA-34a inhibits cell migration and invasion by targeting MMP-2/MMP-9/FNDC3B in esophageal squamous cell carcinoma

MicroRNAs (miRNAs) are a large family of small, non-coding RNAs that play a pivotal role in tumorigenesis. miR‑34a, which is a member of the miR-34 family, is a downstream target of p53. Increasing evidence shows that miR-34a dysregulation may contribute to tumor development and progression in numerous cancers, including esophageal squamous cell carcinoma (ESCC). However, the mechanism of miR-34a in the regulation of ESCC cells need to be further elucidated because of the complex regulative network of miRNAs. The miR-34a expression in ESCC samples has been confirmed using quantitative reverse transcription polymerase chain reaction. The effects of miR-34a on cell migration and invasion were examined in ESCC cell lines using wound healing and Transwell assays, respectively. The effects of miR-34a on matrix metalloproteinase (MMP)-2 and -9 and fibronectin type III domain containing 3B (FNDC3B) expression levels were detected by luciferase reporter assays and western blot analysis. Quantitative polymerase chain reaction revealed that the miR‑34a expression is significantly downregulated in the ESCC tissues compared to that in the adjacent normal tissues. miR-34a overexpression was significantly suppressed migration and invasion in the ESCC cells and simultaneously inhibited the MMP-2, MMP-9 and FNDC3B expression levels by targeting the coding and 3'-untranslated regions, respectively. The findings indicated that microRNA‑34a suppresses cell migration and invasion by targeting MMP-2, MMP-9, and FNDC3B in ESCC.

Exploration of inhibitory mechanisms of curcumin in lung cancer metastasis using a miRNA- transcription factor-target gene network

The present study was aimed to unravel the inhibitory mechanisms of curcumin for lung cancer metastasis via constructing a miRNA-transcription factor (TF)-target gene network. Differentially expressed miRNAs between human high-metastatic non-small cell lung cancer 95D cells treated with and without curcumin were identified using a TaqMan human miRNA array followed by real-time PCR, out of which, the top 6 miRNAs (miR-302b-3p, miR-335-5p, miR-338-3p, miR-34c-5p, miR-29c-3p and miR-34a-35p) with more verified target genes and TFs than other miRNAs as confirmed by a literature review were selected for further analysis. The miRecords database was utilized to predict the target genes of these 6 miRNAs, TFs of which were identified based on the TRANSFAC database. The findings of the above procedure were used to construct a miRNA-TF-target gene network, among which miR-34a-5p, miR-34c-5p and miR-302b-3p seemed to regulate CCND1, WNT1 and MYC to be involved in Wnt signaling pathway through the LEF1 transcription factor. Therefore, we suggest miR-34a-5p/miR-34c-5p/miR-302b-3p —LEF1—CCND1/WNT1/MYC axis may be a crucial mechanism in inhibition of lung cancer metastasis by curcumin.

Inverse correlation between the metastasis suppressor RKIP and the metastasis inducer YY1: Contrasting roles in the regulation of chemo/immuno-resistance in cancer

Several gene products have been postulated to mediate inherent and/or acquired anticancer drug resistance and tumor metastasis. Among these, the metastasis suppressor and chemo-immuno-sensitizing gene product, Raf Kinase Inhibitor Protein (RKIP), is poorly expressed in many cancers. In contrast, the metastasis inducer and chemo-immuno-resistant factor Yin Yang 1 (YY1) is overexpressed in many cancers. This inverse relationship between RKIP and YY1 expression suggests that these two gene products may be regulated via cross-talks of molecular signaling pathways, culminating in the expression of different phenotypes based on their targets. Analyses of the molecular regulation of the expression patterns of RKIP and YY1 as well as epigenetic, post-transcriptional, and post-translational regulation revealed the existence of several effector mechanisms and crosstalk pathways, of which five pathways of relevance have been identified and analyzed. The five examined cross-talk pathways include the following loops: RKIP/NF-κB/Snail/YY1, p38/MAPK/RKIP/GSK3β/Snail/YY1, RKIP/Smurf2/YY1/Snail, RKIP/MAPK/Myc/Let-7/HMGA2/Snail/YY1, as well as RKIP/GPCR/STAT3/miR-34/YY1. Each loop is comprised of multiple interactions and cascades that provide evidence for YY1's negative regulation of RKIP expression and vice versa. These loops elucidate potential prognostic motifs and targets for therapeutic intervention. Chiefly, these findings suggest that targeted inhibition of YY1 by specific small molecule inhibitors and/or the specific induction of RKIP expression and activity are potential therapeutic strategies to block tumor growth and metastasis in many cancers, as well as to overcome anticancer drug resistance. These strategies present potential alternatives for their synergistic uses in combination with low doses of conventional chemo-immunotherapeutics and hence, increasing survival, reducing toxicity, and improving quality of life.

The expression of microRNA 574-3p as a predictor of postoperative outcome in patients with esophageal squamous cell carcinoma

BACKGROUND

Despite advances in radical esophagectomies and adjuvant therapy, the postoperative prognosis in esophageal squamous cell carcinoma (ESCC) patients remains poor. The aim of this study was to identify a molecular signature to predict postoperative favorable outcomes in patients with ESCC.

METHODS

As a training data set, total RNA was extracted from formalin-fixed paraffin-embedded samples of surgically removed specimens from 19 ESCC patients who underwent curative esophagectomy. The expression of microRNA (miRNA) was detected using a miRNA oligo chip on which 885 genes were mounted. As a validation data set, we obtained frozen samples of surgically resected tumors from 12 independent ESCC patients and the expression of miR-574-3p was detected by quantitative real-time PCR.

RESULTS

Our microarray analysis in the training set patients identified three miRNAs (miR-574-3p, miR-106b, and miR-1303) and five miRNAs (miR-1203, miR-1909, miR-204, miR-371-3p, miR-886-3p) which were differentially expressed between the patients with (n = 14) and without (n = 5) postoperative tumor relapse (p < 0.01 and p < 0.05, respectively). Higher expression of miR-574-3p, which showed the most significant association with non-relapse (p = 0.001), was associated with favorable overall survival (p = 0.016). Real-time PCR experiments on the validation set patients confirmed that higher expression of miR-574-3p was associated with non-tumor relapse (p = 0.029) and better overall survival (p = 0.004).

CONCLUSIONS

Our results suggest that the aberrant expression of the miRNAs identified in this study plays key roles in the progression of ESCC. miR-574-3p was suggested to have a tumor suppressor effect, and thus, to be a predictor of postoperative outcome in patients with ESCC.

The role of microRNA in esophageal squamous cell carcinoma

MicroRNAs (miRNA) are 22-nucleotide non-coding RNAs that post-transcriptionally regulate gene expression by base pairing to partially complementary sequences in the 3'-untranslated region of their target messenger RNA. Altered miRNA expression also changes the expression of oncogenes and tumor suppressors, affecting the proliferation, apoptosis, motility and invasibility of gastrointestinal cancer cells, including the cells of esophageal squamous cell carcinoma (ESCC). It has been suggested that various miRNA expression profiles may provide useful biomarkers and therapeutic targets, but to date few studies have been published on the role of miRNA in ESCC. In this review we summarize the identification and characterization of miRNAs involved in ESCC and discuss their potential as biomarkers and therapeutic targets.

Epigenetic regulators: Polycomb-miRNA circuits in cancer

Polycomb group (PcG) proteins belong to a family of epigenetic modifiers and play a key role in dynamic control of their target genes. Several reports have found that aberrations in PcG-microRNA (miRNA) interplay in various cancer types often associated with poor clinical prognosis. This review discusses important PcG-miRNA molecular networks which act as critical interfaces between chromatin remodeling, and transcriptional and post-transcriptional regulation of their target genes in cancer. Moreover, here are discussed several compounds influencing the activity of PcG proteins entered in clinical arena for the treatment of solid tumors, multiple myeloma and B lymphomas, thus highlighting the therapeutic potential of targeting this protein family.

MiR-613: a novel diagnostic and prognostic biomarker for patients with esophageal squamous cell carcinoma

MicroRNA-613 (miR-613) plays important roles in tumorigenesis and cancer progression. We aimed to evaluate its expression level and potential for diagnosis and prognosis in esophageal squamous cell cancer (ESCC). We examined miR-613 expression in 60 pairs of ESCC cancerous and matched paracancerous tissues, serum samples from 75 ESCC patients and 75 healthy volunteers, and 105 formalin-fixed paraffin-embedded (FFPE) tissue samples using quantitative reverse transcription polymerase chain reaction. Receiver-operating characteristic (ROC) curve analysis, Kaplan-Meier method, and Cox regression were applied to analyze its diagnostic and prognostic value. MiR-613 was significantly decreased in ESCC tissue compared with paracancerous tissue (P < 0.001). Moreover, the expression level of miR-613 was significantly reduced with increased T stage of ESCC. Statistically significant difference between ESCC patients and healthy controls in expression level of miR-613 (0.89 ± 0.73 vs. 1.71 ± 1.03, P < 0.001) was found. The area under the ROC curve (AUC) based on serum miR-613 was 0.767 ± 0.040. We also performed analysis on early-stage patients and revealed that the AUC value was 0.728 ± 0.052 (P < 0.001). The Kaplan-Meier curve revealed that the downregulation of miR-613 was related to worse overall survival (OS) and progression-free survival (PFS) of ESCC patients (P = 0.018 and P = 0.035, respectively). Furthermore, the multivariate analysis identified miR-613 to be an independent prognostic factor for OS and PFS (P = 0.031 and P = 0.006, respectively) In conclusion, miR-613 is significantly reduced in cancerous tissue and serum samples of ESCC patients. It can serve as an ideal indicator for the diagnosis and prognosis of ESCC.

Deregulation of miR-93 and miR-143 in human esophageal cancer

Esophageal squamous cell carcinoma (ESCC) is the second and third most common malignancy in Iranian males and females, respectively. Treatment of ESCC is largely ineffective due to lack of detection at early stages of the disease. In recent years, miRNA, a small RNA molecule, has drawn much attention to researchers as a potential biomarker for esophageal cancer. miR-93 and miR-143 are two miRNA molecules reported to be frequently deregulated in various cancers, including prostate, stomach, cervix, and etc. The purpose of this study was to investigate the expression levels of these miRNAs and evaluate their diagnostic and therapeutic potential in esophageal squamous cell carcinoma. In this study, total RNA was extracted from 30 tumor tissues and 30 nontumor tissues of esophageal tumor margins, using RNX-plus solution. After validating the quality and quantity of total RNA, cDNAs of interest were synthesized using microRNA-specific cDNA Synthesis Kit. The expression level of miR-93 and miR-143 was evaluated using quantitative real-time PCR with miRNA-specific primers. Finally, the obtained data was analyzed by SPSS ver.20 software and paired t test was performed to observe the significance of difference between groups. The expression level of miR-93 was significantly increased and of miR-143 was significantly decreased in most of the examined tumor tissues, compared to nontumor tissues. Also, our findings did not detect correlation between mir-93 and mir-143 expressions in regard to stage and grade of the samples. These findings suggest that the deregulation of these miRNAs may play an important role in esophageal squamous cell carcinoma. Both miR-93 and miR-143 might be used as potential biomarkers in esophageal squamous cell carcinoma. However, more studies with large population of samples are necessary.