Relationship between altered expression levels of MIR21, MIR143, MIR145, and MIR205 and clinicopathologic features of esophageal squamous cell carcinoma

Roles of MicroRNAs in Esophageal Squamous Cell Carcinoma Pathogenesis

MicroRNAs (miRNAs) are 20-22 nucleotides long single-stranded noncoding RNAs. They regulate gene expression posttranscriptionally by base pairing with the complementary sequences in the 3'-untranslated region of their targeted mRNA. Aberrant expression of miRNAs leads to alterations in the expression of oncogenes and tumor suppressors, thereby affecting cellular growth, proliferation, apoptosis, motility, and invasion capacity of gastrointestinal cells, including cells of esophageal squamous cell carcinoma (ESCC). Thus, alterations in miRNAs expression associated with the pathogenesis and progression of ESCC. In addition, expression profiles of miRNAs correlated with various clinicopathological factors, including pathological stages, histological differentiation, invasion, metastasis of cancer, as well as survival rates and therapy response of patients with ESCC. Consequently, expression profiles of miRNAs could be useful as diagnostic, prognostic, and prediction biomarkers in ESCC. Herein, we describe the quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and microarray methods for detection and quantitate miRNAs in ESCC. In addition, we summarize the roles of miRNAs in ESCC pathogenesis, progression, and prognosis.

The predictive value of microRNAs for pathological response after neoadjuvant treatment in esophageal squamous cell carcinoma: a systematic review

Neoadjuvant treatment followed by esophagectomy has been the standard strategy for resectable locally advanced esophageal squamous cell carcinoma (ESCC). Pathological response after neoadjuvant treatment is of vital importance in the determination of long-term survival. Due to the involvement of microRNAs (miRNAs) in ESCC, some studies have proposed miRNA models to predict the pathological response. We aimed to summarize current studies on the predictive value of the miRNA models. We searched the relevant studies on PubMed, Web of Science and Cochrane Library up to February 14, 2020, using the following search term: (esophageal OR esophagus OR oesophageal OR oesophagus) AND (miR OR miRNA OR microRNA) AND (neoadjuvant OR preoperative OR induction). The initial search retrieved 206 studies. We briefly summarized the involvement of miRNAs in the origin, development and chemo- and radioresistance in ESCC. Then, 9 studies were enrolled in the systematic review. A great heterogeneity was observed across these studies. Of the 6 studies with diagnostic tests, the area under curve varied a lot. Although much evidence demonstrated the correlation between miRNAs and pathological response after in ESCC, the current studies has not established any promising models. A well-designed prospective study is essential to investigate the potential predictive models for pathological response after neoadjuvant treatment in ESCC.

miR-21 Overexpression Promotes Esophageal Squamous Cell Carcinoma Invasion and Migration by Repressing Tropomyosin 1

The migration and invasion of esophageal squamous cell carcinoma are associated with clinical outcomes, however, the mechanisms remain poorly understood. Here, we found that miR-21 is significantly overexpressed in ESCC, lung cancer, and bladder cancer compared with the adjacent normal tissue. MiR-21 and TPM1 expressions were analyzed by RT-qPCR and WB in 30 ESCC, 10 lung cancer, and 10 bladder cancer clinical specimens, each with matched adjacent normal tissue. Knockdown and overexpression of miR-21 as well as knockdown of TPM1 in ESCC cell lines were performed using synthetic oligonucleotides. TPM1 3′UTR luciferase reporter constructs were used to investigate targeting of TPM1 by miR-21. ESCC migration and invasion were assessed using transwell migration and invasion assays. Inhibition of miR-21 reduced migration and invasion in two ESCC cell lines, and overexpression of miR-21 promoted migration and invasion in vitro. Interestingly, TPM1 exhibited inverse patterns of expression compared with miR-21 in tissues and cell lines. Luciferase reporter assays demonstrated that TPM1 was directly regulated by miR-21. Moreover, the forced overexpression of miR-21 repressed the TPM1 expression, while silencing of miR-21 restored the TPM1 expression in ESCC cell lines. What is more, simultaneous silencing of miR-21 and TPM1 expressions did not alter the migratory and invasive characteristics demonstrating that the effects of miR-21 were mediated through TPM1. In conclusion, the aberrant overexpression of miR-21 is common in cancer and promotes the migration and invasion of ESCC through inhibiting the TPM1 expression. These results suggest that miR-21 may be a novel predictive marker and therapeutic target for treatment of ESCC.

Evaluation of Roles of MicroRNA-21 and MicroRNA-18a in Esophageal Squamous Cell Carcinoma and Comparison of Their Changes in Expression Post-Chemoradiotherapy

Background

A number of circulating microRNAs (miRNAs) have been reported to be highly expressed in several cancers; whether their expression is associated with clinicopathological factors and prognosis in patients of esophageal squamous cell carcinoma (ESCC) is still under investigation. Although studies have demonstrated their overexpression in tissues of ESCC, there are limited data for circulating miRNAs. Aim of this study was to evaluate the expressions of miRNA-21 and miRNA-18a in patients of ESCC and the effect of chemoradiotherapy (CRT) on expression of these miRNAs.

Methods

This was a case-control study conducted from September 2014 to December 2015 at Sri Aurobindo Medical College and Postgraduate Institute, Indore, India. We compared the expression of miRNA-21 and miRNA-18a in 30 ESCC patients and 30 healthy controls using TaqMan probe-based quantitative real-time polymerase chain reaction (qRT-PCR) and changes in the expression in 16 patients of ESCC, who completed CRT.

Results

Both miRNA-21 and miRNA-18a had significantly higher levels of expression in ESCC patients than healthy controls (95% confidence interval (CI): 5.73 - 34.79; P < 0.002 and 95% CI: 3,361.36 - 6,744.23; P < 0.001), respectively. Receiver operating characteristic (ROC) curve analysis showed that combination of serum miRNA-18a and miRNA-21 overexpression could efficiently distinguish patients of ESCC from healthy controls. The miRNA-21 expression positively correlated with tumor invasion (P < 0.004), lymphatic metastasis (P < 0.011), distant metastasis (P < 0.038), and tumor stage (P < 0.001); however, there was no such association observed with miRNA-18a. In the treatment phase (post-CRT), a significant reduction (P < 0.001) was observed in both miRNAs (73.4% in miRNA-18a and 81.02% in miRNA-21).

Conclusions

Both miRNA-21 and miRNA-18a were highly overexpressed in patients of ESCC and their expressions changed significantly with CRT. These miRNAs may be useful tools for the diagnosis and assessment of treatment response in ESCC patients. Further studies will be needed to validate these findings using large number of patients.

Identification of crucial miRNAs and genes in esophageal squamous cell carcinoma by miRNA-mRNA integrated analysis

Esophageal squamous cell carcinoma (ESCC) is a malignancy that severely threatens human health and carries a high incidence rate and a low 5-year survival rate. MicroRNAs (miRNAs) are commonly accepted as a key regulatory function in human cancer, but the potential regulatory mechanisms of miRNA-mRNA related to ESCC remain poorly understood.The GSE55857, GSE43732, and GSE6188 miRNA microarray datasets and the gene expression microarray datasets GSE70409, GSE29001, and GSE20347 were downloaded from Gene Expression Omnibus databases. The differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) were obtained using GEO2R. Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for DEGs were performed by Database for Annotation, Visualization and Integrated Discovery (DAVID). A protein-protein interaction (PPI) network and functional modules were established using the STRING database and were visualized by Cytoscape. Kaplan-Meier analysis was constructed based on The Cancer Genome Atlas (TCGA) database.In total, 26 DEMs and 280 DEGs that consisted of 96 upregulated and 184 downregulated genes were screened out. A functional enrichment analysis showed that the DEGs were mainly enriched in the ECM-receptor interaction and cytochrome P450 metabolic pathways. In addition, MMP9, PCNA, TOP2A, MMP1, AURKA, MCM2, IVL, CYP2E1, SPRR3, FOS, FLG, TGM1, and CYP2C9 were considered to be hub genes owing to high degrees in the PPI network. MiR-183-5p was with the highest connectivity target genes in hub genes. FOS was predicted to be a common target gene of the significant DEMs. Hsa-miR-9-3p, hsa-miR-34c-3p and FOS were related to patient prognosis and higher expression of the transcripts were associated with a poor OS in patients with ESCC.Our study revealed the miRNA-mediated hub genes regulatory network as a model for predicting the molecular mechanism of ESCC. This may provide novel insights for unraveling the pathogenesis of ESCC.

Serum miR-331-3p predicts tumor recurrence in esophageal adenocarcinoma

MicroRNAs (miRNAs) may contribute to the initiation and progression of cancer. The role of circulating miRNAs as predictors of recurrence in esophageal adenocarcinoma (EAC) has not been extensively explored. Here we measured the expressions of 167 miRNAs in serum samples from a discovery cohort of 72 EAC patients (32 patients with recurrence and 40 patients without). A rank sum test was performed to identify differentially expressed miRNAs. Cox regression model was applied to estimate the effect of miRNA expression on recurrence-free survival. The eligible miRNAs were then validated in an independent cohort of 329 EAC patients (132 patients with recurrence and 197 patients without). miR-331-3p was identified and confirmed to be differentially expressed between EAC patients with and without recurrence and associated with recurrence-free survival. In both cohorts, the expression of miR-331-3p was consistently decreased in patients with recurrence compared to those without (P < 0.05). Using patients with low expression of miR-331-3p as reference, those with high expression had HRs for recurrence of 0.45 (95% CI, 0.21-0.96, P = 0.040) and 0.55 (95% CI, 0.38-0.78, P = 0.001) in the discovery and validation cohorts, respectively. Therefore, serum miR-331-3p may be a useful biomarker for identifying EAC patients at high risk of recurrence.

Comparative miRNA Expression Profile Analysis of Squamous Cell Carcinoma and Peritumoral Mucosa from the Meso- and Hypopharynx

BACKGROUND/AIM

The role of microRNAs (miRNA) in carcinogenesis is related to their genome-regulatory function. The aim of the present study was to identify and compare miRNA expression signatures of meso- and hypopharynx squamous cell cancers in consideration of the cancer field hypothesis.

PATIENTS AND METHODS

Thirteen snap-frozen biopsy series of tumors and peritumoral tissues from the meso- and hypopharynx were analyzed regarding their miRNA expression with quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Significant miRNA expression changes of miR-21, -27a, -34a, -143 and -146a were found in peritumoral tissues that were dependent from the tumor location and the distance from the primary tumor site.

CONCLUSION

miRNA expression analysis was found to be appropriate for molecular segregation of tumor location and peritumoral tissue segments, and appears to be a promising marker for cancer field characterization.

Clinical utility of miR-143/miR-182 levels in prognosis and risk stratification specificity of BFM-treated childhood acute lymphoblastic leukemia

Although childhood acute lymphoblastic leukemia (ALL) is characterized by high remission rates, there are still patients who experience poor response to therapy or toxic effects due to intensive treatment. In the present study, we examined the expression profile of miR-143 and miR-182 in childhood ALL and evaluated their clinical significance for patients receiving Berlin-Frankfurt-Münster (BFM) protocol. Bone marrow specimens from 125 childhood ALL patients upon diagnosis and the end-of-induction (EoI; day 33), as well as from 64 healthy control children undergone RNA extraction, polyadenylation, and reverse transcription. Expression levels of miRNAs were quantified by qPCR analysis. Patients' cytogenetic, immunohistotype and MRD evaluation was performed according to international guidelines. Median follow-up time was 86.0 months (95% CI 74.0-98.0), while patients' mean DFS and OS intervals were 112.0 months (95% CI 104.2-119.8) and 109.2 months (95% CI 101.2-117.3), respectively. Bone marrow levels of miR-143/miR-182 were significantly decreased in childhood ALL patients at diagnosis and increased in more than 90% of patients at the EoI. Patients' survival analysis highlighted that children overexpressing miR-143/miR-182 at the EoI presented significantly higher risk for short-term relapse (log-rank test: p = 0.021; Cox regression: HR = 4.911, p = 0.038) and death (log-rank test: p = 0.028; Cox regression: HR = 4.590, p = 0.046). Finally, the evaluation of the miR-143/miR-182 EoI levels along with the established disease prognostic markers resulted to improved prediction of BFM-treated patients' survival outcome and response to therapy and additionally to superior BFM risk stratification specificity. Concluding, miR-143 and miR-182 could serve as novel prognostic molecular markers for pediatric ALL treated with BFM chemotherapy.

MicroRNAs in esophageal squamous cell carcinoma: Potential biomarkers and therapeutic targets

Esophageal cancer is a common cause of cancer-related deaths worldwide. Squamous cell carcinoma (SCC) is the major histological type of esophageal cancer in developing countries including China, and the prognosis is very poor. Many microRNAs are involved in several important biological and pathologic processes, and promote tumorigenesis. To better understand the prognostic and therapeutic roles of microRNAs in ESCC, we reviewed the diagnosis and prognosis associated oncogenic microRNAs (e.g. miR-21 and miR-17-92 cluster) and tumor suppressor microRNAs (e.g. miR-375, miR-133a and miR-133b), and diagnosis and prognosis associated oncogenic target genes (e.g. PDCD4 and CCND1) and tumor suppressor target genes (e.g. EZH2 and PDK1). We also summarized the prognostic microRNA and target gene pairs (e.g. miR-296 and CCND1, miR214 and EZH2). Taken together, our review highlights the opportunities and challenges for microRNAs in the molecular diagnosis and target therapy of ESCC.

PART-1 functions as a competitive endogenous RNA for promoting tumor progression by sponging miR-143 in colorectal cancer

LncRNAs were altered in several cancers and played a crucial role in various biological activities and progressions of different diseases, including proliferation, chemical resistance, and metastasis. In the present study, we revealed that prostrate androgen-regulated transcript-1 (PART-1) was highly expressed in colorectal cancer cells and tissues, and knockdown of PART-1 suppressed cell proliferation and metastasis, both in vitro and in vivo. In addition, PART-1 functioned as a ceRNA of DNMT3A, by sponging miR-143. Finally,PART-1 induced tumor progression by regulating DNMT3A.

Expression of MMP9, SERPINE1 and miR-134 as prognostic factors in esophageal cancer

Esophageal cancer (EC) is a malignant tumor with a typically poor prognosis for patients. It is well known that certain microRNA (miRNA/miR) genes can regulate other genes responsible for carcinogenesis. In the present study, a group of these genes (miR-21, miR-134, miR-205 and miR-495) and genes connected with cancer-related pathways (MET, MMP9, PDGFA and SERPINE1) were chosen for analysis in order to find a potential correlation between their expression and the clinicopathological factors of EC. Esophageal tumors and adjacent non-cancerous tissue specimens were collected from a total of 63 patients and embedded in paraffin. Commercial arrays were used on KYSE-30, KYSE-150 and KYSE-270 EC cell lines in order to find genes of different expression profiles compared with those acquired from the control Het-1A cell line. Quantitative polymerase chain reaction was used on formalin-fixed, paraffin-embedded samples in order to analyze the expression of the genes chosen in the earlier step. The results were analyzed by the Kruskal-Wallis and Mann-Whitney U tests, Spearman's rank correlation coefficient, Kaplan-Meier methods and the long-rank test. Only miR-495 was not expressed in the analyzed samples. The expression of MMP9 and SERPINE1 was significantly coefficient with age range (P=0.011 and P=0.044, respectively) according to the Kruskal-Wallis test. The Spearman's rank-order correlation measurement showed that there was a coefficient correlation between age and miR-134 expression. The same measurement demonstrated a correlation between age range and MMP9 expression. The expression of miR-134 and MMP9 were also found to be correlated. In all cases, a value of P<0.049 was recorded. Overall, the present study demonstrated that MMP9, SERPINE1 and miR-134 were the most prognostic genes in Caucasian patients with EC.

Circulating Plasma Levels of MicroRNA-21 and MicroRNA-221 Are Potential Diagnostic Markers for Primary Intrahepatic Cholangiocarcinoma

Background

MicroRNAs (miRNAs) are potential biomarkers in various malignancies. We aim to characterize miRNA expression in intrahepatic cholangiocarcinoma (ICC) and identify circulating plasma miRNAs with potential diagnostic and prognostic utility.

Methods

Using deep-sequencing techniques, miRNA expression between tumor samples and non-neoplastic liver parenchyma were compared. Overexpressed miRNAs were measured in plasma from an independent cohort of patients with cholangiocarcinoma using RT-qPCR and compared with that healthy volunteers. The discriminatory ability of the evaluated plasma miRNAs between patients and controls was evaluated with receiving operating characteristic (ROC) curves.

Results

Small RNAs from 12 ICC and 11 tumor-free liver samples were evaluated. Unsupervised hierarchical clustering using the miRNA expression data showed clear grouping of ICC vs. non-neoplastic liver parenchyma. We identified 134 down-regulated and 128 upregulated miRNAs. Based on overexpression and high fold-change, miR21, miR200b, miR221, and miR34c were measured in plasma from an independent cohort of patients with ICC (n = 25) and healthy controls (n = 7). Significant overexpression of miR-21 and miR-221 was found in plasma from ICC patients. Furthermore, circulating miR-21 demonstrated a high discriminatory ability between patients with ICC and healthy controls (AUC: 0.94).

Conclusion

Among the differentially expressed miRNAs in ICC, miR-21 and miR-221 are overexpressed and detectable in the circulation. Plasma expression levels of these miRNAs, particularly miR-21, accurately differentiates patients with ICC from healthy controls and could potentially serve as adjuncts in diagnosis. Prospective validation and comparison with other hepatobiliary malignancies is required to establish their potential role as diagnostic and prognostic biomarkers.

Reciprocal interplay between thyroid hormone and microRNA-21 regulates hedgehog pathway-driven skin tumorigenesis

The thyroid hormone-inactivating (TH-inactivating) enzyme type 3 iodothyronine deiodinase (D3) is an oncofetal protein that is rarely expressed in adult life but has been shown to be reactivated in the context of proliferation and neoplasms. D3 terminates TH action within the tumor microenvironment, thereby enhancing cancer cell proliferation. However, the pathological role of D3 and the contribution of TH metabolism in cancer have yet to be fully explored. Here, we describe a reciprocal regulation between TH action and the cancer-associated microRNA-21 (miR21) in basal cell carcinoma (BCC) skin tumors. We found that, besides being negatively regulated by TH at the transcriptional level, miR21 attenuates the TH signal by increasing D3 levels. The ability of miR21 to positively regulate D3 was mediated by the tumor suppressor gene GRHL3, a hitherto unrecognized D3 transcriptional inhibitor. Finally, in a BCC mouse model, keratinocyte-specific D3 depletion markedly reduced tumor growth. Together, our results establish TH action as a critical hub of multiple oncogenic pathways and provide functional and mechanistic evidence of the involvement of TH metabolism in BCC tumorigenesis. Moreover, our results identify a miR21/GRHL3/D3 axis that reduces TH in the tumor microenvironment and has potential to be targeted as a therapeutic approach to BCC.

MiRNA Expression Analysis of Pretreatment Biopsies Predicts the Pathological Response of Esophageal Squamous Cell Carcinomas to Neoadjuvant Chemoradiotherapy

OBJECTIVE

To identify miRNA markers useful for esophageal squamous cell carcinoma (ESCC) neoadjuvant chemoradiotherapy (neo-CRT) response prediction.

SUMMARY

Neo-CRT followed by surgery improves ESCC patients' survival compared with surgery alone. However, CRT outcomes are heterogeneous, and no current methods can predict CRT responses.

METHODS

Differentially expressed miRNAs between ESCC pathological responders and nonresponders after neo-CRT were identified by miRNA profiling and verified by real-time quantitative polymerase chain reaction (qPCR) of 27 ESCCs in the training set. Several class prediction algorithms were used to build the response-classifying models with the qPCR data. Predictive powers of the models were further assessed with a second set of 79 ESCCs.

RESULTS

Ten miRNAs with greater than a 1.5-fold change between pathological responders and nonresponders were identified and verified, respectively. A support vector machine (SVM) prediction model, composed of 4 miRNAs (miR-145-5p, miR-152, miR-193b-3p, and miR-376a-3p), were developed. It provided overall accuracies of 100% and 87.3% for discriminating pathological responders and nonresponders in the training and external validation sets, respectively. In multivariate analysis, the subgroup determined by the SVM model was the only independent factor significantly associated with neo-CRT response in the external validation sets.

CONCLUSIONS

Combined qPCR of the 4 miRNAs provides the possibility of ESCC neo-CRT response prediction, which may facilitate individualized ESCC treatment. Further prospective validation in larger independent cohorts is necessary to fully assess its predictive power.

Low expression of microRNA-202 is associated with the metastasis of esophageal squamous cell carcinoma

The present study aimed to determine the expression levels and biological functions of microRNA-202 (miR-202) in patients with esophageal squamous cell carcinoma (ESCC). A total of 60 patients with ESCC and 30 healthy individuals were enrolled and reverse transcription-quantitative polymerase chain reaction was performed to measure the expression levels of miR-202. In order to investigate the effects of miR-202 expression levels on the proliferative, migratory and invasive abilities of ESCC cells, methylthiazolyl-tetrazolium bromide proliferation, in vitro scratch and Transwell® chamber assays were performed. Expression levels of miR-202 were significantly decreased in the peripheral blood of patients with ESCC, which is associated with the degree of cell differentiation and lymph node metastasis (P<0.05). Following miR-202 transfection, cell proliferation was significantly inhibited (P<0.05). Cell migration and invasion was also significantly inhibited by miR-202 transfection (P<0.05). The results of the present study demonstrated that the expression of miR-202 inhibited the proliferation, migration and invasion of ESCC cells. Furthermore, low expression levels of miR-202 were detected in the peripheral blood of patients with ESCC, which is associated with the development, invasion and metastasis of ESCC.

DGCR8 is essential for tumor progression following PTEN loss in the prostate

In human prostate cancer, the microRNA biogenesis machinery increases with prostate cancer progression. Here, we show that deletion of the Dgcr8 gene, a critical component of this complex, inhibits tumor progression in a Pten-knockout mouse model of prostate cancer. Early stages of tumor development were unaffected, but progression to advanced prostatic intraepithelial neoplasia was severely inhibited. Dgcr8 loss blocked Pten null-induced expansion of the basal-like, but not luminal, cellular compartment. Furthermore, while late-stage Pten knockout tumors exhibit decreased senescence-associated beta-galactosidase activity and increased proliferation, the simultaneous deletion of Dgcr8 blocked these changes resulting in levels similar to wild type. Sequencing of small RNAs in isolated epithelial cells uncovered numerous miRNA changes associated with PTEN loss. Consistent with a Pten-Dgcr8 association, analysis of a large cohort of human prostate tumors shows a strong correlation between Akt activation and increased Dgcr8 mRNA levels. Together, these findings uncover a critical role for microRNAs in enhancing proliferation and enabling the expansion of the basal cell compartment associated with tumor progression following Pten loss.

miRNA-mRNA crosstalk in esophageal cancer: From diagnosis to therapy

The asymptomatic nature of esophageal cancer (EC) at early stages results in late clinical presentation leading to poor prognosis and limited success of therapeutic modalities. Efforts to identify diagnostic/prognostic markers have proven to be unsuccessful for translation into clinics. Hence, there is a pressing need for establishment of novel non-invasive biomarker for early diagnosis/better prognosis of EC. Recently, alteration in microRNA (miRNA) expression has emerged as an important hallmark of cancer. This review summarizes the differential expression of miRNAs in EC and addresses how their aberrant expression influences crucial biological processes such as apoptosis, cell proliferation, invasion and metastasis. Additionally, this review highlights the current status of circulating miRNA based diagnostic/prognostic markers. An effort has been made to find a connection between different miRNAs involved in EC and a detailed analysis has been done to screen out micoRNAs involved in prognosis and multidrug resistance. Further, investigation of these miRNAs would not only provide a gene therapy based strategy to prevent/treat cancer but also to reverse multidrug resistance leading to decreased requirement of harmful chemotherapeutic drugs.

MiR-9 and miR-21 as prognostic biomarkers for recurrence in papillary thyroid cancer

Despite low mortality rates, nodal recurrence in papillary thyroid carcinoma occurs in up to 20 % of patients. Emerging evidences indicate that dysregulated microRNAs are implicated in the process of metastasis. In the present study, we investigated whether miR-9, miR-10b, miR-21 and miR-146b levels are predictive of papillary thyroid carcinoma recurrence. Using macro-dissection followed by quantitative real-time PCR, we measured miR-9, miR-10b, miR-21 and miR-146b expression levels in formalin-fixed, paraffin-embedded samples of 66 patients with papillary thyroid carcinoma categorized into two groups: the recurrent group (n = 19) and the non-recurrent group (n = 47). All patients underwent total thyroidectomy and were followed for at least 120 months after surgery to be considered recurrence-free. Univariate and multivariate analysis were performed using the Cox proportional hazard model in order to identify associations between multiple clinical variables and microRNA expression levels and papillary thyroid carcinoma recurrence. MiR-9 and miR-21 expression levels were found to be significant prognostic factors for recurrence in patients with papillary thyroid carcinoma (HR = 1.48; 95 % CI 1.24-1.77, p < 0.001; and HR = 1.52; 95 % CI 1.18-1.94, p = 0.001; respectively). Multivariate analysis involving the expression level of miR-9 and miR-21 and various clinical parameters identified the expression of these microRNAs as independent prognostic factors for papillary thyroid cancer patients. In conclusion, our results support the potential clinical value of miR-9 and miR-21 as prognostic biomarkers for recurrence in papillary thyroid carcinoma.

Analysis of circulating microRNAs during adjuvant chemotherapy in patients with luminal A breast cancer

Breast cancer is a complex disease displaying different profiles involving genetic as well as epigenetic factors. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate gene expression. Recent studies demonstrated that miRNAs may display great potential for the development of novel biomarkers and therapeutic targets. In the present study, the levels of miR-21 and miR-145 were analyzed in the peripheral blood of 52 patients with luminal A breast cancer. miRNA expression was determined in serum samples from matched pre- and post-treatment patients with breast cancer by quantitative polymerase chain reaction. There were no statistically significant differences in miR-145 and miR-21 levels between pre- and post-treatment samples. In addition, the miRNA levels were not found to be associated with the clinical parameters.

Upregulation of miR-494 Inhibits Cell Growth and Invasion and Induces Cell Apoptosis by Targeting Cleft Lip and Palate Transmembrane 1-Like in Esophageal Squamous Cell Carcinoma

BACKGROUND

Potential target genes of microRNA (miR)-494 have been reported in many types of cancers. However, the role of miR-494 in esophageal squamous cell carcinoma (ESCC) remains unknown.

AIM

This study focused on the expression and biological function of miR-494 in ESCC.

METHODS

Using bioinformatics analyses, we found that cleft lip and palate transmembrane 1-like (CLPTM1L) was a potential target of miR-494. We performed quantitative real-time (qRT) PCR assays in 37 ESCC tumor tissues to determine the expression of miR-494 and CLPTM1L mRNA, and we analyzed the correlation between both of these factors and clinical characteristics. The cell counting kit-8 and colony formation assays were used to evaluate the effects of miR-494 expression on the proliferation of ESCC cells. The transwell migration assay and flow cytometric apoptosis assay were performed to study the influence of miR-494 on the invasion and apoptosis of ESCC cells. Western blotting, luciferase assays, and CLPTM1L knockdown experiments were used to determine whether CLPTM1L was a target of miR-494.

RESULTS

The qRT-PCR assays showed significant downregulation of miR-494 (P < 0.05) and upregulation of CLPTM1L mRNA (P < 0.05), both of which were significantly associated with lymph node metastases (P < 0.05). High expression of miR-494 inhibited cell proliferation and invasion and promoted cell apoptosis (P < 0.05). The results also showed that CLPTM1L was a target of miR-494.

CONCLUSION

These results show that the expression of miR-494, which can regulate cell growth, invasion and apoptosis of ESCC cells by targeting CLPTM1L, is downregulated in ESCC tumor tissues. The miR-494-CLPTM1L pathway could be further exploited to develop a new approach to treat ESCC.

Current status of predictive biomarkers for neoadjuvant therapy in esophageal cancer

Neoadjuvant therapy has been proven to be extremely valuable and is widely used for advanced esophageal cancer. However, a significant proportion of treated patients (60%-70%) does not respond well to neoadjuvant treatments and develop severe adverse effects. Therefore, predictive markers for individualization of multimodality treatments are urgently needed in esophageal cancer. Recently, molecular biomarkers that predict the response to neoadjuvant therapy have been explored in multimodal approaches in esophageal cancer and successful examples of biomarker identification have been reported. In this review, promising candidates for predictive molecular biomarkers developed by using multiple molecular approaches are reviewed. Moreover, treatment strategies based on the status of predicted biomarkers are discussed, while considering the international differences in the clinical background. However, in the absence of adequate treatment options related to the results of the biomarker test, the usefulness of these diagnostic tools is limited and new effective therapies for biomarker-identified nonresponders to cancer treatment should be concurrent with the progress of predictive technologies. Further improvement in the prognosis of esophageal cancer patients can be achieved through the introduction of novel therapeutic approaches in clinical practice.

[MicroRNA expression profiles in squamous cell carcinomas of the meso- and hypopharynx]

INTRODUCTION

MicroRNAs play a role in carcinogenesis through their genome regulatory function.

AIM

The aim of the authors was to identify and compare microRNA expression signatures of meso- and hypopharynx squamous cell cancers on the basis of the cancer field hypothesis.

METHOD

Using standard mapping biopsy (tumour tissue and macroscopically normal tissues obtained 1, 2 and 3 cm from margin) 13 snap frozen sample series were analysed for microRNA expression with quantitative real-time polymerase chain reaction.

RESULTS

MiR-221 was significantly overexpressed in mesopharynx cancers, whole miR-21, miR-143 and miR-155 showed significant overexpression in hypopharynx cancers.

CONCLUSIONS

Using microRNA expression profiles the authors were able to distinguish peritumoural tissues according to distance from the primary tumour site. Future application of the method may prove to be useful in early detection of the altered epigenetic regulation in tissue fields representing normal phenotype. This may be helpful in cancer risk assessment and prevention.

Comparison of long non‑coding RNAs, microRNAs and messenger RNAs involved in initiation and progression of esophageal squamous cell carcinoma

Traditionally, cancer research has focused on protein‑coding genes, which are considered the principal effectors and regulators of tumorigenesis. Non‑coding RNAs, in particular microRNAs (miRNAs) and long non‑coding RNAs (lncRNAs), have been widely reported to be important in the regulation of tumorigenesis and cancer development. However, to the best of our knowledge, investigation of the expression profiles of lncRNAs and a comparison of the involvement of lncRNAs, miRNAs and messenger RNAs (mRNAs) in esophageal tumorigenesis and development have not previously been performed. In the current study, intrinsic associations among the expression profiles of lncRNAs, miRNAs and mRNAs from normal esophageal tissues and those from cancer tissues were investigated. Oligonucleotide microarrays were used to detect the expression profiles of the three types of RNA in the canceration processes of human esophageal squamous cell carcinoma (ESCC) tissues. It was demonstrated that the different RNAs exhibit associated patterns of expression among normal esophageal epithelium, low‑grade intraepithelial neoplasia (LGIN), high‑grade intraepithelial neoplasia (HGIN), and carcinoma tissues, particularly in the critical period of canceration (HGIN to ESCC). Furthermore, the results indicated a high level of similarity in the potential function of lncRNAs, miRNAs and mRNAs in the processes of ESCC development. In the current study, a first generation atlas of lncRNA profiling and its association with miRNAs and mRNAs in the canceration processes of ESCC were presented.

MicroRNA143 and tumors of the digestive system

Recent studies have found that microRNAs have functions analogous to oncogenes or tumor suppressor genes and are important molecules in tumor occurrence and development. In particular, downregulation of microRNA-143 expression in tumors of the digestive system can inhibit tumor proliferation, infiltration and metastasis via regulation of its target genes. In this paper, we review the latest research progress in understanding the role of microRNA-143 in the digestive system.

Down regulation of miR-143 is related with tumor size, lymph node metastasis and HPV16 infection in cervical squamous cancer

Objective

This study is to investigate the role of miR-143 expression in cervical squamous cell carcinoma (SCC).

Methods

The expression level of miR-143 was examined by quantitative real-time PCR. Human papillomavirus (HPV) genotype was detected by HPV genotype detection kit. The expression level of bcl-2 was detected by immunohistochemistry.

Results

The positive rate of HPV was 78% in the patients of cervical SCC. The most prevalent genotype was HPV16, with a positive rate of 42%. The expression level of miR-143 was significantly lower in the cervical SCC tissues than that in the normal cervical tissues (Z = −2.180, P = 0.029). Down-regulated miR-143 expression was associated with tumor size, lymph node metastasis and HPV16 infection in cervical cancer patients. No significant associations were found between the expression levels of miR-143 and age, clinical stage, differentiation or lymph vascular space invasion. And, in cervical SCC patients after treatment with Taxol chemotherapy, the expression level of miR-143 was higher and the positive expression of bcl-2 protein was lower. However, the differences in expression changes of miR-143 and bcl-2 were not statistically significant (miR-143, Z = −0.763, P = 0.446; bcl-2 protein, χ² = 2.277, P = 0.131).

Conclusion

Down-regulated miR-143 is related with tumor size, lymph node metastasis and HPV16 infection in cervical SCC, but miR-143 does not participate in the Taxol sensitivity response.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1401279451112150.

Different expression of miRNAs in early esophageal squamous cell carcinoma with differential prognosis

Patients at the same pathological stage of early esophageal squamous cell carcinoma (ESCC) have significantly different prognoses. The aim of this study was to explore the relationship between specific microRNAs (miRNAs) in two groups of early ESCC patients who had different prognoses at the pT1N0 stage, and to study the prognostic significance of different miRNAs in early ESCC metastasis. We tried to identify prognostic markers that may be helpful in the selection of appropriate treatment for patients with early ESCC. We used TaqMan Human miRNA Arrays to detect and analyze bioinformatically the expression profiles of miRNAs in two groups, and the reverse transcription polymerase chain reaction method to verify the differences in miRNA expression. The miRNA arrays revealed a total of 29 markedly downregulated miRNAs in the survival group compared with the deceased group. Such miRNAs were associated with lympho-vascular invasion and metastasis, and acted as predictive markers of lympho-vascular invasion and metastasis. The detection of these miRNAs forms an important basis for the treatment of early ESCC. It can also help determine those patients with early ESCC who are good candidates for endoscopic resection treatment and those who need additional treatment after endoscopic resection.

Novel diagnostic and prognostic biomarkers in esophageal cancer

INTRODUCTION

This article provides an overview of actual biomarkers with an impact on improvement of diagnosis and treatment of esophageal cancer patients.

AREAS COVERED

Recent literature has been analyzed and provides information regarding the potential role of molecular markers as a diagnostic or prognostic factor in esophageal cancer.

EXPERT OPINION

Until now, the role of molecular markers is far from being firmly established for routine use and is not without obstacles. However, with reliable standardized methods, established cut-off values and promising candidates in marker panels with markers of genetic, epigenetic and proteomic origin might result in a marker tool worthwhile of being validated in large, prospective, randomized trials. Novel validated marker combinations have to be clinically applied to prove their putative role in complementing clinical techniques within the development of better detection concepts of esophageal cancer, improving patients' long-term prognosis by early and purposive therapy within individualized treatment concepts.

Expression, tissue distribution and function of miR-21 in esophageal squamous cell carcinoma

Objective

MiR-21 is an oncomir expressed by malignant cells and/or tumor microenvironment components. In this study we focused on understanding the effects of stromal miR-21 on esophageal malignant cells.

Design

MiR-21 expression was evaluated in formalin-fixed paraffin-embedded samples from patients with esophageal squamous-cell carcinoma (SCC) by quantitative RT-PCR. MiR-21 tissue distribution was visualized with in situ hybridization. A co-culture system of normal fibroblasts and esophageal cancer cells was used to determine the effects of fibroblasts on miR-21 expression levels, and on SCC cell migration and invasion.

Results

MiR-21 was overexpressed in SCCs, when compared to the adjacent non-tumor tissues (P = 0.0007), and was mainly localized in the cytoplasm of stromal cells adjacent to malignant cells. Accordingly, miR-21 expression was increased in tumors with high versus low stromal content (P = 0.04). When co-cultured with normal fibroblasts, miR-21 expression was elevated in SCC cells (KYSE-30), while its expression was restricted to fibroblasts when co-cultured with adenocarcinoma cells (OE-33 and FLO-1). MiR-21 was detected in conditioned media of cancer cell lines, illustrating the release of this miRNA into the environment. Co-culturing with normal fibroblasts or addition of fibroblast conditioned media caused a significant increase in cell migration and invasion potency of KYSE-30 cells (P<0.0001). In addition, co-culturing cancer cells with fibroblasts and expression of miR-21 induced the expression of the cancer associated fibroblast (CAF) marker S100A4.

Conclusions

MiR-21 expression is mostly confined to the SCC stroma and its release from fibroblasts influences the migration and invasion capacity of SCC cells. Moreover, miR-21 may be an important factor in “activating” fibroblasts to CAFs. These findings provide new insights into the role of CAFs and the extracellular matrix in tumor microenvironment formation and in tumor cell maintenance, and suggest miR-21 may contribute to cellular crosstalk in the tumor microenvironment.

Downregulation of miR-145 contributes to lung adenocarcinoma cell growth to form brain metastases

The development of metastases involves the dissociation of cells from the primary tumor, penetrating the basement membrane, invasion and exiting from the vasculature to seed, and finally colonizing in distant tissues. The formation of brain metastasis (BM) in lung adenocarcinoma remains poorly understood. We examined the differential microRNA (miRNA) expression profiles of 5 primary and 3 brain metastatic lung adenocarcinoma samples by Agilent miRNA Microarrays. Five upregulated miRNAs (miRs-9*, -1471, 718, 3656, 720) and 3 downregulated miRNAs (miRs-214, -145 and -23a) were detected. The 4 most significantly deregulated miRNAs (miR-145, miR-214, miR-9* and miR-1471) were validated in the additional 43 samples (35 primary and 8 brain metastatic lung adenocarcinoma samples) using TaqMan quantitative PCR. By functional assay, we found that the expression of miR-145 can regulate the ability of proliferation of A549 and SPC-A1 cells in vitro, but is not related to lymph node metastasis, migration and invasion. These results suggest that miR-145 may have a cell type-specific function and play important roles in the process of BM from lung adenocarcinoma.

A review of the current understanding and clinical utility of miRNAs in esophageal cancer

BACKGROUND

MicroRNAs (miRNAs) are a class of small, well-conserved, non-coding RNAs that regulate the translation of RNAs. They have a role in biological and pathological process including cell differentiation, apoptosis, proliferation and metabolism. Since their discovery, they have been shown to have a potential role in cancer pathogenesis through their function as oncogenes or tumor suppressors. A substantial number of miRNAs show differential expression in esophageal cancer tissues, and so have been investigated for possible use in diagnosis. Furthermore, there is increasing interest in their use as prognostic markers and determining treatment response, as well as identifying their downstream targets and understanding their mode of action.

METHODS

We analyzed the most recent studies on miRNAs in esophageal cancer and/or Barrett's esophagus (BE). The publications were identified by searching in PuBMed for the following terms: Barrett's esophagus and microRNA; esophageal cancer and microRNA.

RESULTS

Four miRNAs (mi-R-25, -99a, -133a and -133b) showed good potential as diagnostic markers and interestingly five (mi-R-21, -27b, -126, - 143 and -145) appeared to be useful both as diagnostic and prognostic/predictive markers.

CONCLUSION

The data so far on miRNAs in esophageal carcinogenesis is promising but further work is required to determine whether miRNAs can be used as biomarkers, not only in the clinical setting or added to individualized treatment regimes but also in non-invasive test by making use of miRNAs identified in blood.

Distinctive microRNAs in esophageal tumor: early diagnosis, prognosis judgment, and tumor treatment

Esophageal tumor (ET) is aggressive and has poor prognosis. Although the incidence of ET has been reduced by the changing tumor profile, the 5-year survival and mortality rate of ET has not significantly changed, and the outlook has remained bleak. Therefore, new molecular markers for early diagnosis and prognosis judgment are urgently required. In recent years, tumor has been widely regarded as genetic disease along with epigenetic abnormalities. DNA methylation, histone deacetylation, chromatin remodeling, gene imprinting, and noncoding RNA regulation are the major parts of epigenetic regulation. Mounting evidence exists that miRNAs (microRNA), a class of small, endogenous, and non-protein-coding RNAs, provide a novel tool for early clinical diagnosis, prognosis judgment, and gene therapy of ET. In this review, we provide a general overview of the connection between miRNA profiles and their target genes. We also describe in detail in ET from the aspect of clinical insights, the potential application of miRNAs as biomarkers, potential diagnostic and therapeutic tools.

The role of microRNAs in cancers of the upper gastrointestinal tract

Cancers of the oesophagus, gastro-oesophageal junction and stomach (upper gastrointestinal tract cancers; UGICs) pose a major health risk around the world. Collectively, the 5-year survival rate has remained <15%, and therapeutic improvements have been very slow and small. Novel molecules for early diagnosis, prognosis and therapy are, therefore, urgently needed. The role that microRNA (miRNA) molecules have in UGICs are worth pursuing to this end. miRNAs are small noncoding RNA molecules that regulate ∼60% of coding genes in humans and, therefore, are pivotal in mediating and regulating many physiologic processes. miRNAs are deregulated in many disease states, particularly in cancer, making them important targets. Here, we review the growing body of evidence regarding the alterations of miRNAs in UGICs. By suppressing translation and/or promoting degradation of mRNAs, miRNAs can contribute to carcinogenesis and progression of UGICs. In-depth studies of miRNAs in UGICs might yield novel insights and potential novel therapeutic strategies.

MicroRNA-143 functions as a tumor suppressor in human esophageal squamous cell carcinoma

Esophageal cancer is one of the most common cancers worldwide with a poor prognosis. MicroRNAs(miRNAs) are a class of naturally occurring small noncoding RNAs and play an important role in cancer initiation and development. In this study, we demonstrate that the expression levels of miR-143 and miR-145 were significantly decreased in ESCC tissues in comparison with adjacent normal esophageal squamous tissues(NESTs). Furthermore, an inverse correlation between miR-143 and tumor invasion depth and lymph node metastasis was observed. The enforced expression of miR-143 induced growth suppression and apoptosis of ESCC cells. Rescue of miR-143 significantly suppressed the ESCC cells migration and invasion capabilities. Moreover, we show that functions of miR-143 in ESCC are mediated at least in part by the inhibition of extracellular signal regulated kinase-5(ERK-5) activity. These results prove that miR-143 may act as a tumor suppressor in ESCC.

Analysis of microRNAs and their precursors in bovine early embryonic development

In animals, the maternal-to-embryonic transition (MET) occurs in the first days of early development and involves the degradation of maternal transcripts that have been stored during oogenesis. Moreover, precise and specific control mechanisms govern the adequate synchronization of the MET events to promote the activation of the embryonic genome. These mechanisms are not well understood, but it is believed that microRNAs (miRNAs) could be one of the mechanisms involved. After a microarray screening study, we analysed the expression of specific miRNA during oocyte maturation and early embryo development until preimplantation stages. Two differentially expressed candidates were selected for further analysis. Mature and precursor forms of miR-21 and miR-130a were quantified by qRT-PCR in pools of 20 oocytes at GV (germinal vesicle), GV breakdown and metaphase II stages as well as in pools of embryos at the 2-cell, 4-cell, 8-cell and blastocyst stages. The results showed a linear increase during the 1-8 cell stage for the mature forms of miR-130a and miR-21 (P < 0.05 and P < 0.003, respectively) and for the precursor form of miR-130a (P < 0.002). To see if this increase was due to minor transcriptional activity, 2-cell embryos were exposed to α-amanitin for 30-34 h. Results showed a significant decrease in miR-21, pre-miR-21, miR-130a and SRFS3 in α-amanitin-treated embryos (P < 0.05). Considering the potential regulatory role of these miRNA, the bovine genome was screened to identify putative targets with a 3'UTR exact seed match. This study suggests that miRNAs could be important players in the MET, as expression profiles suggest a potential regulation role during early development steps.

Northwestern China: a place to learn more on oesophageal cancer. Part two: gene alterations and polymorphisms

In the first part of this review, some behavioural and environmental risk factors playing important roles in the development of Kazakh's oesophageal squamous cell carcinoma (OSCC) were presented. Although all individuals have been exposed to the same environment and share the same behaviour, some of them will not develop OSCC. Thus, gene susceptibility and/or gene polymorphism are unavoidably involved. The molecular events underlying the initiation and progression of OSCC remain, however, poorly understood. In the second part of our review of OSCC in northwestern China, especially in the high-risk Kazakh population, some recent progress in the study of the molecular biology underlying oesophageal carcinogenesis, including chromosome deletions and loss of heterozygocity, polymorphisms of genes involved in xenobiotic metabolizing and DNA repair, and genetic alterations of transcriptional factors and apoptosis genes are presented. Results obtained in this high-risk population are compared with those obtained in other areas that are also known to be at high risk for OSCC, and whenever possible, with those studies performed in European, American or Australian low-risk areas. Recent advances in the investigation of the proteomics and microRNA biomarkers potentially useful for an earlier diagnosis and/or prognosis of OSCC are also discussed.

MicroRNA involvement in esophageal carcinogenesis

MicroRNAs (miRs) have recently emerged as a novel class of gene expression regulators. The number of studies documenting an altered miR expression pattern in cancer continues to expand rapidly. Critical information is continuously gained regarding how aberrantly expressed miRs contribute to carcinogenesis. Current studies provide evidence that analyses of miR expression patterns have potential clinical applications toward developing tumor biomarkers to identify the presence and dissemination of esophageal cancer, as well as to assess tumor chemosensitivity or radiosensitivity. The incidence of esophageal cancer is on the rise, and this disease continues to portend a poor prognosis. The current review addresses ways in which altered miR expression contributes to esophageal carcinogenesis, along with how recent discoveries may be applied clinically.

Towards an extension of the two-variable model of carcinogenesis through oncogenes and tumour suppressor genes

Currently, carcinogenesis is considered to be the result of mal-expression of tumour suppressor genes and oncogenes, leading either way to uncontrollable and disorganized cell mitosis. Recently a novel class of genes has drawn the interest of the scientific community. These are microRNAs (miRNAs), a class of noncoding RNAs, 20-23 nucleotides in length, that can up or downregulate gene expression of downstream gene targets (including transcription factors, oncogenes, and tumour suppressor genes) at the post-transcriptional level. Some members of this new class of genes seem to have the potential to act simultaneously either as oncogenes or as tumour suppressor genes depending on the molecular microenvironment of the cell. We elaborate on this hypothesis by giving examples of miRNAs (e.g. mir-9, miR-17-92) which seem to function by the abovementioned mechanism. This could mean that the deterministic notion of carcinogenesis as a result of merely tumour suppressor genes and oncogenes deregulation could be revised to contain the fact that certain members of this novel class of genes have the potential to play both roles simultaneously.