Prognostic value of microRNA expression in operable non-small cell lung cancer patients

Targeted microRNA Profiling in Gastric Cancer with Clinical Assessement

Although several microRNAs (miRNAs) have been associated with gastric cancer there is still the need for identification of stable and validated biomarkers. The purpose of this study was to determine the alterations of a specific set of miRNA levels in gastric adenocarcinoma tissues to identify and validate gastric cancer-specific miRNAs using paired normal and tumor samples in an independent patient cohort. Gastric adenocarcinoma and normal stomach tissue samples of 20 patients who underwent surgery for gastric cancer were studied. The miRNA expression profiling was performed for eight miRNAs in a total of 40 tissue samples using quantitative reverse transcription polymerase chain reaction (RT-qPCR). Six out of these eight miRNAs, namely, miR-375-3p, hsamiR-129-5p, miR-196a-5p, miR-376c-3p, miR-34c-5p and miR-767-5p, were significantly underexpressed in malignant tissues of our cohort. Furthermore, the expression of miR-662 although not significantly different between normal and tumor tissues, was inversely associated with age (r = −0.440, p = 0.049). The levels of miR-129-3p and miR34c-5p were correlated with an increase in the number of metastatic lymph nodes (r = 0.470, p = 0.036; r = 0.510, p = 0.020), while and miR-376c-3p levels were negatively associated with smoking (p = 0.043). In addition, we found that the variability of miRNA expression in cancerous tissues was lower than that in normal tissues. Alterations in miRNA expression in gastric adenocarcinoma tissues in comparison to healthy tissues of each individual serves for identification of consistent biomarkers that can be used for development of diagnostic tools for gastric cancer.

Computational and Bioinformatics Methods for MicroRNA Gene Prediction

MicroRNAs (miRNAs) are 20-24-nucleotide-long noncoding RNAs that bind to the untranslated region (3' UTR) of their target mRNAs. The importance of miRNAs in medicine has grown rapidly in the 20 years since the discovery of them. As the regulatory function of miRNAs on biological processes was discovered, they were advocated to play a role in the underlying mechanisms of human pathogenesis. Functional studies have confirmed that miRNAs are promising in preclinical development through deregulation of genes targeted by miRNAs in many cancer cases. In this chapter, we summarize the miRNAs identified for some specific types of cancer and their functions. Besides, miRNAs function as cancer biomarker and their benefits to diagnosis and treatment of cancer are also discussed.

Diagnostic value of PPARδ and miRNA-17 expression levels in patients with non-small cell lung cancer

The PPARδ gene codes protein that belongs to the peroxisome proliferator-activated receptor (PPAR) family engaged in a variety of biological processes, including carcinogenesis. Specific biological and clinical roles of PPARδ in non-small cell lung cancer (NSCLC) is not fully explained. The association of PPARα with miRNA regulators (e.g. miRNA-17) has been documented, suggesting the existence of a functional relationship of all PPARs with epigenetic regulation. The aim of the study was to determine the PPARδ and miR-17 expression profiles in NSCLC and to assess their diagnostic value in lung carcinogenesis. PPARδ and miR-17 expressions was assessed by qPCR in NSCLC tissue samples (n = 26) and corresponding macroscopically unchanged lung tissue samples adjacent to the primary lesions served as control (n = 26). PPARδ and miR-17 expression were significantly lower in NSCLC than in the control (p = 0.0001 and p = 0.0178; respectively). A receiver operating characteristic (ROC) curve analysis demonstrated the diagnostic potential in discriminating NSCLC from the control with an area under the curve (AUC) of 0.914 for PPARδ and 0.692 for miR-17. Significant increase in PPARδ expression in the control for current smokers vs. former smokers (p = 0.0200) and increase in miR-17 expression in control tissue adjacent to adenocarcinoma subtype (p = 0.0422) were observed. Overexpression of miR-17 was observed at an early stage of lung carcinogenesis, which may suggest that it acts as a putative oncomiR. PPARδ and miR-17 may be markers differentiating tumour tissue from surgical margin and miR-17 may have diagnostic role in NSCLC histotypes differentiation.

Computational Recognition and Clinical Verification of TGF-β-Derived miRNA Signature With Potential Implications in Prognosis and Immunotherapy of Intrahepatic Cholangiocarcinoma

MicroRNAs (miRNAs) were recently implicated in modifying the transforming growth factor β (TGF-β) signaling in multiple cancers. However, TGF-β-derived miRNAs and their potential clinical significance remain largely unexplored in intrahepatic cholangiocarcinoma (ICC). In this study, we proposed an integrated framework that enables the identification of TGF-β-derived miRNAs in ICC (termed “TGFmitor”). A total of 36 TGF-β-derived miRNAs were identified, of which nine significantly correlated with overall survival (OS) and aberrantly expressed in ICC. According to these miRNAs, we discovered and validated a TGF-β associated miRNA signature (TAMIS) in GSE53870 (n =63) and TCGA-CHOL (n =32). To further confirm the clinical interpretation of TAMIS, another validation based on qRT-PCR results from 181 ICC tissues was performed. TAMIS was proven to be an independent risk indicator for both OS and relapse-free survival (RFS). TAMIS also displayed robust performance in three cohorts, with satisfactory AUCs and C-index. Besides, patients with low TAMIS were characterized by superior levels of CD8+ T cells infiltration and PD-L1 expression, while patients with high TAMIS possessed enhanced CMTM6 expression. Kaplan-Meier analysis suggested CMTM6 could further stratify TAMIS. The TAMIS^highCMTM6^high subtype had the worst prognosis and lowest levels of CD8A and PD-L1 expression relative to the other subtypes, indicating this subtype might behave as “super-cold” tumors. Notably, the improved discrimination was observed when CMTM6 was combined with TAMIS. Overall, our signature could serve as a powerful tool to help improve prognostic management and immunotherapies of ICC patients.

Plasma miR-32 levels in non-small cell lung cancer patients receiving platinum-based chemotherapy can predict the effectiveness and prognosis of chemotherapy

BACKGROUND

Previous studies have shown that microRNA-32 (miRNA-32) is an exosome microRNA that affects the proliferation and metastasis of non-small cell lung cancer (NSCLC) cells. In this study, our goal was to assess the expression of plasma microRNA-32 and its potential as a biomarker to predict the tumor response and survival of patients with NSCLC undergoing platinum-based chemotherapy.

METHODS

Plasma microRNA-32 levels before and after 1 cycle of platinum-based chemotherapy in 43 patients with NSCLC were measured using a quantitative real-time polymerase chain reaction assay (qPCR). In addition, the demographic and survival data of the patients were collected for analysis.

RESULTS

A significant correlation was observed between the changes in microRNA-32 levels before and after 1 chemotherapy cycle and the treatment response (P = .035). In addition, Kaplan-Meier analysis showed that the level of microRNA-32 after 1 chemotherapy cycle was significantly correlated with the prognosis of patients. The median progression-free survival (P = .025) and overall survival (P = .015) of patients with high microRNA-32 levels (≥7.73) after 1 chemotherapy cycle was 9 and 21 months, respectively. In contrast, the median survival of patients with low microRNA-32 levels (<7.73) was 5 and 10 months, respectively.

CONCLUSIONS

The plasma levels of microRNA-32 correlated with the efficacy of platinum-based chemotherapy and survival, indicating that microRNA-32 may be useful for predicting the effectiveness of platinum-based chemotherapy and prognosis in NSCLC.

MicroRNAs: Potential Biomarkers and Targets of Therapy in Allergic Diseases?

MicroRNAs (miRNAs) are small non-coding RNA molecules that are 18-22 nucleotides long and highly conserved throughout evolution. Currently, they are considered one of the fundamental regulatory mechanisms of genes expression. It has been demonstrated that miRNAs are involved in many biologic processes, such as signal transduction, cell proliferation and differentiation, apoptosis and stress responses. More recently, the role of miRNA has also been revealed in numerous immunological and inflammatory disorders, including allergic inflammation. Specific miRNA profiles were demonstrated in asthma, allergic rhinitis and atopic dermatitis. A core set of miRNAs involved in atopic diseases include upregulated miR-21, miR-223, miR-146a, miR-142-5p, miR-142-3p, miR-146b, miR-155 and downregulated let-7 family, miR-193b and miR-375. Most of the involved miRNAs increase secretion of Th2 cytokines (miR-1248, miR-146b), decrease secretion of Th1 cytokines (miR-513-5p, miR-625-5p) or promote differentiation of T cells towards Th2 (miR-21, miR-19a). In asthma miR-140-3p, miR-708 and miR-142-3p play a role in hyperplasia and hypertrophy of bronchial smooth muscle cells. Some single miRNAs or, more probably, their sets hold the promise for their use as biomarkers of atopic diseases. They are also promising target of future therapies.

Increased Pain Sensitivity in Obese Patients After Lung Cancer Surgery

Background: Obesity and cancer are recognized worldwide health threats. While there is no reported causal relationship, the increasing frequency of both conditions results in a higher incidence of obese patients who are being treated for cancer. Physiological data indicate that there is a relationship between obesity and susceptibility to pain; however, currently, there are no specific pharmacological interventions.

Objective: To evaluate the self-reported intensity of postoperative pain in obese and nonobese lung cancer who receive either thoracotomy or video-assisted thoracic surgery (VATS) surgical therapy.

Material and Methods: In 50 obese [mean body mass index (BMI) of 34.1 ± 3.2 kg/m²] and 62 nonobese (mean BMI of 24.9 ± 3 kg/m²) lung cancer patients, the intensity of pain was estimated every 4 h using a visual analog scale (VAS, 0 indicating no pain and 10 indicating “worst imaginable pain”) beginning shortly after surgery (Day O) and continuing until the day of discharge (Day D).

Results: The self-reported pain was more severe in obese than in nonobese patients, both at the time of the operation [Day O (4.5 ± 1.2 vs 3.4 ± 1.1; p < 0.0001)] and at the day of discharge [Day D (3.9 ± 1.4 vs 2.6 ± 0.9, p < 0.0001)]. This finding was consistent both in the patients after thoracotomy and after video-assisted thoracic surgery (VATS, p < 0.0001). The patients with severe pain shortly after surgery (VAS score >4) had significantly higher BMI (31.8 ± 5.6 kg/m²vs 28.8 ± 5.2 kg/m², p < 0.01) and were hospitalized longer than the remaining patients (13.0 ± 13.6 days vs 9.5 ± 3.6 days, p < 0.05).

Conclusion: The reported perception of pain in obese lung cancer patients is greater than in nonobese patients undergoing the same thoracic surgery. In obese patients, severe pain persisted longer. Pain management is an important consideration in the postoperative care of lung cancer patients, even more so with obese patients.

Prognostic Role of Circulating miRNAs in Early-Stage Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is the primary cause of cancer-related death worldwide, with a low 5-year survival rate even in fully resected early-stage disease. Novel biomarkers to identify patients at higher risk of relapse are needed. We studied the prognostic value of 84 circulating microRNAs (miRNAs) in 182 patients with resected early-stage NSCLC (99 adenocarcinoma (ADC), 83 squamous cell carcinoma (SCC)) from whom peripheral blood samples were collected pre-surgery. miRNA expression was analyzed in relation to disease-free survival (DFS) and overall survival (OS). In univariable analyses, five miRNAs (miR-26a-5p, miR-126-3p, miR-130b-3p, miR-205-5p, and miR-21-5p) were significantly associated with DFS in SCC, and four (miR-130b-3p, miR-26a-5p, miR-126-3p, and miR-205-5p) remained significantly associated with OS. In ADC, miR-222-3p, miR-22-3p, and mir-93-5p were significantly associated with DFS, miR-22-3p remaining significant for OS. Given the high-dimensionality of the dataset, multivariable models were obtained using a regularized Cox regression including all miRNAs and clinical covariates. After adjustment for disease stage, only miR-126-3p showed an independent prognostic role, with higher values associated with longer DFS in SCC patients. With regard to ADC and OS, no miRNA remained significant in multivariable analysis. Further investigation into the role of miR-126 as a prognostic marker in early-stage NSCLC is warranted.

miR-210 promotes lung adenocarcinoma proliferation, migration, and invasion by targeting lysyl oxidase-like 4

Accumulating evidence has revealed that various microRNAs are deregulated and involved in lung cancer development and metastasis. miR-210 is implicated in several cancer progression. However, the detailed biological function and role of miR-210 in lung adenocarcinoma remains unclear. Our current study was aimed to investigate the mechanism of miR-210 in lung adenocarcinoma progression. We observed that miR-210 was significantly upregulated in lung cancer cell lines (A549 and H1650) in comparison to BEAS-2B cells. In addition, we found that miR-210 was greatly elevated in lung adenocarcinoma tissues. Then, it was shown that overexpression of miR-210 was able to promote lung cancer cell proliferation and colony formation ability while inhibitors of miR-210 exhibited a reversed phenomenon. Subsequently, A549 and H1650 cell migration and invasion capacity were obviously restrained by miR-210 inhibition whereas induced by miR-210 mimics. Lysyl oxidase-like 4 (LOXL4), a member of the secreted copper-dependent amine oxidases has been found to be increased or decreased in different cancer types. Here, we confirmed that LOXL4 could serve as a downstream target of miR-210 and miR-210 promoted lung cancer progression via targeting LOXL4. In A549 and H1650 cells, knockdown of LOXL4 dramatically repressed lung cancer cell proliferation, migration, and invasion. In conclusion, our study implied that miR-210 might indicate a new perspective for lung cancer.

Prognostic value of microRNAs in lung cancer: A systematic review and meta-analysis

Lung cancer is one of the leading causes of cancer-associated mortality throughout the world. The prognosis of the disease depends on many factors including the stage and type of cancer. Many studies have identified various microRNAs (miRNAs) that affect the prognosis of lung cancer. In order to systemically analyze the available clinical data, the present study performed a meta-analysis to examine all evidence on the potential role of miRNAs as novel predictors of survival in lung cancer. Literature published in English prior to February 1st, 2018 was searched through PubMed to review all of the associations between individual miRNAs and groups of miRNAs with the prognosis of lung cancer. Data was extracted using standard forms and pooled odds ratios with 95% confidence intervals (CIs) were calculated. A total of 15 eligible studies were included in the meta-analysis. These represented 1,753 lung cancer patients and 20 miRNAs. A total of 8 downregulated miRNAs were associated with poorer overall survival (OS) [hazard ratio (HR)=0.59, 95% CI: 0.47–0.75, P<1×10⁻⁴], while 10 upregulated miRNAs were associated with poorer OS (HR=1.76, 95% CI: 1.31–2.35, P<1×10⁻⁴). Additionally, low miRNA expression was associated with lymph node metastasis [LNM; relative risk (RR)=0.53, 95% CI: 0.46–0.61, P<1×10⁻⁴]. The expression of miRNAs was not associated with lung cancer stage (RR=1.07, 95% CI: 0.94–1.22, P=0.23). Expression levels of different miRNAs were associated with the OS and LNM of patients with lung cancer. These miRNAs may be applied as potential prognostic markers in lung cancer.

Prognostic Role of MicroRNAs in Human Non-Small-Cell Lung Cancer: A Systematic Review and Meta-Analysis

Background

MicroRNAs (miRNAs) have been found to play an important role in the development and outcomes for multiple human cancers. Their role as a prognostic biomarker in non-small-cell lung cancer (NSCLC) remains unclear. This meta-analysis aims to clarify the role of various miRNAs in the survival of NSCLC patients.

Materials and Methods

All studies were identified through medical database search engines. A meta-analysis was conducted to assess the correlation between miRNAs expressions and overall survival among those NSCLC studies. Relevant data were extracted from each eligible study regarding baseline characteristics and key statistics such as hazard ratio (HR), 95% confidence interval (CI), and P value, which were utilized to calculate a pooled effect size.

Result

Thirty-two studies were included in the meta-analysis. Using a random effect model, the combined HR and 95% CI for overall survival (OS) was calculated as 1.59 (1.39–1.82), predicting a poor overall survival. Five miRNAs (miR-21, miR-155, miR-let-7, miR-148a, and miR-148b) were found to be of significance for predicting OS in at least two studies, hence, selected for subgroup analysis. Subgroup analysis disclosed that elevated levels of miR-21 and miR-155 in both cancer tissue and blood samples were associated with worse OS. Compared to American studies (I-squared: <0.001% and P value: 0.94), Asian and European studies exhibited greater heterogeneity in miRNA expression and relationship to OS (I-squared, P values were approximately 78.85%, <0.001 and 61.28%, 0.006, respectively). These subgroup analyses also highlighted that elevated expression of miR-21 and miR-155 and low levels of expression of miR-148a, miR-148b, and miR-let-7 were associated with poor prognosis in NSCLC.

Conclusion

miR-21, miR-155, miR-148a, miR-148b, and miR-let-7 are consistently up- or downregulated in NSCLC and are associated with poor OS. These miRNAs show potential as useful prognostic biomarkers in the diagnosis, treatment, and follow-up of NSCLC.

The fundamental role of miR-10b in metastatic cancer

Small, non-coding strands of RNA have been identified as a significant player in the pathology of cancer. One of the first miRNAs to be shown as having aberrant expression in cancer was miR-10b. Since the inaugural study on miR-10b, its role as a metastasis promoting factor has been extensively validated. To date, more than 100 studies have been completed on miR-10b and metastasis across 18 cancer types. This immense set of information holds possibilities for novel methods to improve the lives of many. This review outlines what is currently understood of miR-10b's clinical significance, its molecular regulation, and the possible diagnostic and therapeutic methods leveraging miR-10b as a fundamental target in metastatic cancer. Such methods would move us closer to developing a truly individualized therapeutic strategy against cancer and will likely provide unique information about cancer staging, disease outcome, metastatic potential, and ultimately survival.

Clinicopathological significance of miR-26, miR-107, miR-125b, and miR-203 in head and neck carcinomas

OBJECTIVES

MicroRNAs play a role in the development and progression of head and neck squamous cell carcinomas (HNSCC). Our aim was to study the expression of miR-26, miR-107, miR-125b, and miR-203 in primary HNSCC with and without lymph node metastasis and their clinicopathological significance.

MATERIALS AND METHODS

The expression of microRNAs in primary HNSCC with lymph node metastasis (n = 16) and their matched lymph node, as well as primary tumors without metastasis (n = 16), were determined by quantitative RT-PCR and analyzed with clinicopathological features and survival.

RESULTS

The expression levels of miR-26 (p < .05) and miR-125b (p < .01) were higher in metastatic primary HNSCC, while levels of miR-203 (p < .01) were lower. The expression of the microRNAs was associated with clinicopathological features, including miR-26 high expression and N stage (p = .04), poor differentiation (p = .005) and recurrence (p = .007), miR-125b high expression and N stage (p = .0005) and death (p = .02), and low levels of miR-203 and N stage (p = .04). The high expression of miR-26 was associated with shortened disease-free survival, and high miR-125b expression was an independent risk factor for poor disease-specific survival.

CONCLUSIONS

These findings suggest that miR-26 and miR-125b may be associated with the progression and metastasis of HNSCC and that miR-203 is associated with a more favorable prognosis.

Identification of recurrence-associated microRNAs in stage I lung adenocarcinoma

Lung cancer is the most common cause of cancer-associated death worldwide. Postoperative relapse and subsequent metastasis result in a high mortality rate, even in early stage lung cancer. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the post-transcriptional level and are frequently dysregulated in various cancers. The aim of this study was to identify recurrence-associated miRNAs in early stage lung cancer. To screen for differentially expressed miRNAs related to postoperative recurrence, miRNA microarray data derived from stage I lung adenocarcinoma formalin-fixed paraffin-embedded (FFPE) tissue samples (n = 6) and publically available the Cancer Genome Atlas (TCGA) data were analyzed. An independent sample (n = 29) was used to validate candidate miRNAs by quantitative real-time polymerase chain reaction (qRT-PCR). In miRNA expression profiling, we identified 60 significantly dysregulated miRNAs in the relapsed group. Additionally, 20 dysregulated miRNAs were found using TCGA data set. Three miRNAs (let-7g-5p, miR-143-3p, and miR-374a-5p) were associated with postoperative recurrence in both microarray and TCGA data sets. All 3 candidate miRNAs were validated in the independent cohort of stage I adenocarcinoma by qRT-PCR. We discovered 3 recurrence-associated miRNAs of stage I lung adenocarcinoma samples using FFPE tissue, which showed possible clinical utility as biomarkers predicting recurrence after curative surgery. Further investigation of the functional properties of these miRNAs is needed.

MiR-192 and miR-662 enhance chemoresistance and invasiveness of squamous cell lung carcinoma

OBJECTIVES

Overexpression of miR-192, miR-192* and miR-662 was previously found to correlate with poor prognosis of early-stage squamous cell lung cancer (SCC) patients. In this study, we investigated the relevance of these miRNAs to cancer cell biology and chemoresistance.

MATERIALS AND METHODS

MiRNA expression profile was analysed in 10 non-small cell lung cancer (NSCLC) cell lines using RT-qPCR. H520 and H1703 cells were transfected with miRNA inhibitors (anti-miR-192, -192* and -662) for functional studies. Chemoresistance to cisplatin and etoposide was evaluated using MTT colorimetric assay. H520 cells were subjected to 3D soft-agar colony formation assay and H1703 cells to wound healing assay. Whole transcriptome analysis was used to assess the effect of miR-192 and miR-662 inhibition on gene expression.

RESULTS

SCC cell lines, H520 and H1703, differed in miRNA expression and phenotypic features. MiR-192 and miR-662 inhibition decreased clonogenicity and motility of SCC cells. MiR-192 and miR-662 inhibition sensitized SCC cells to etoposide but not to cisplatin. Whole transcriptome analysis revealed genes regulated by miR-192 and miR-662 in SCC, relevant to maintaining chemoresistance, invasiveness, epithelial-mesenchymal transition (EMT) and immune evasion.

CONCLUSIONS

We showed for the first time that miR-192 and miR-662 have functional role in SCC cells. Our findings suggest that targeting these miRNAs may impact both chemoresistance and invasiveness of SCC, and add to the evidence linking these aspects of tumour biology. Overexpression of miR-192 and miR-662 might be useful as a marker of resistance to etoposide.

Prediction of potential drivers connecting different dysfunctional levels in lung adenocarcinoma via a protein-protein interaction network

Lung cancer is a serious disease that threatens an affected individual's life. Its pathogenesis has not yet to be fully described, thereby impeding the development of effective treatments and preventive measures. "Cancer driver" theory considers that tumor initiation can be associated with a number of specific mutations in genes called cancer driver genes. Four omics levels, namely, (1) methylation, (2) microRNA, (3) mutation, and (4) mRNA levels, are utilized to cluster cancer driver genes. In this study, the known dysfunctional genes of these four levels were used to identify novel driver genes of lung adenocarcinoma, a subtype of lung cancer. These genes could contribute to the initiation and progression of lung adenocarcinoma in at least two levels. First, random walk with restart algorithm was performed on a protein-protein interaction (PPI) network constructed with PPI information in STRING by using known dysfunctional genes as seed nodes for each level, thereby yielding four groups of possible genes. Second, these genes were further evaluated in a test strategy to exclude false positives and select the most important ones. Finally, after conducting an intersection operation in any two groups of genes, we obtained several inferred driver genes that contributed to the initiation of lung adenocarcinoma in at least two omics levels. Several genes from these groups could be confirmed according to recently published studies. The inferred genes reported in this study were also different from those described in a previous study, suggesting that they can be used as essential supplementary data for investigations on the initiation of lung adenocarcinoma. This article is part of a Special Issue entitled: Accelerating Precision Medicine through Genetic and Genomic Big Data Analysis edited by Yudong Cai & Tao Huang.

MicroRNA profiling associated with non-small cell lung cancer: next generation sequencing detection, experimental validation, and prognostic value

Background

The average five-year survival for non-small cell lung cancer (NSCLC) patients is approximately 15%. Emerging evidence indicates that microRNAs (miRNAs) constitute a new class of gene regulators in humans that may play an important role in tumorigenesis. Hence, there is growing interest in studying their role as possible new biomarkers whose expression is aberrant in cancer. Therefore, in this study we identified dysregulated miRNAs by next generation sequencing (NGS) and analyzed their prognostic value.

Methods

Sequencing by oligo ligation detection technology was used to identify dysregulated miRNAs in a training cohort comprising paired tumor/normal tissue samples (N = 32). We validated 22 randomly selected differentially-expressed miRNAs by quantitative real time PCR in tumor and adjacent normal tissue samples (N = 178). Kaplan-Meier survival analysis and Cox regression were used in multivariate analysis to identify independent prognostic biomarkers.

Results

NGS analysis revealed that 39 miRNAs were dysregulated in NSCLC: 28 were upregulated and 11 were downregulated. Twenty-two miRNAs were validated in an independent cohort. Interestingly, the group of patients with high expression of both miRNAs (miR-21^high and miR-188^high) showed shorter relapse-free survival (RFS) and overall survival (OS) times. Multivariate analysis confirmed that this combined signature is an independent prognostic marker for RFS and OS (p = 0.001 and p < 0.0001, respectively).

Conclusions

NGS technology can specifically identify dysregulated miRNA profiles in resectable NSCLC samples. MiR-21 or miR-188 overexpression correlated with a negative prognosis, and their combined signature may represent a new independent prognostic biomarker for RFS and OS.

miR-297 acts as an oncogene by targeting GPC5 in lung adenocarcinoma

OBJECTIVES

Emerging studies have demonstrated that microRNAs (miRNAs) play crucial roles in carcinogenesis of many developing human tumours. However, the functions and mechanisms of miR-297 in lung cancer have, up to now, been largely undefined.

MATERIALS AND METHODS

Here, miR-297 expression was measured in lung adenocarcinoma tissues and cell lines, using qRT-PCR. Lung adenocarcinoma cell line was treated with an miR-297 mimic. MTT and colony analysis were performed to detect cell proliferation and colony formation. The direct target gene of miR-297 was assessed by qRT-PCR, Western blotting and luciferase assays.

RESULTS

We demonstrated that miR-297 expression was upregulated in lung adenocarcinomas compared to adjacent normal tissues. Expression of miR-297 was also upregulated in tested lung adenocarcinoma cell lines. Ectopic expression of miR-297 enhanced lung adenocarcinoma cell proliferation and colony formation. Furthermore, overexpression of miR-297 promoted cell migration and invasion. In addition, we identified Glypican-5 (GPC5) as a direct target gene of miR-297 in lung adenocarcinoma cells. Expression of GPC5 was downregulated in both lung adenocarcinoma tissues and cell lines. Moreover, expression of GPC5 was inversely associated with expression of miR-297 in lung adenocarcinoma tissues.

CONCLUSIONS

These results suggest that miR-297 acted as an oncogenic miRNA, partly by targeting GPC5, adenocarcinoma of the lung.

Recent advances in epigenomics in NSCLC: real-time detection and therapeutic implications

NSCLC is an aggressive disease with one of the poorer prognosis among cancers. The disappointing response to chemotherapy drives the search for genetic biomarkers aimed at both attaining an earlier diagnosis and choosing the most appropriate chemotherapy. In this scenario, epigenomic markers, such as DNA methylation, histone acetylation and the expression of noncoding RNAs, have been demonstrated to be reliable for the stratification of NSCLC patients. Newest techniques with increased sensitivity and the isolation of nucleic acids from plasma may allow an early diagnosis and then monitoring the efficacy over time. However, prospective confirmatory studies are still lacking. This article presents an overview of the epigenetic markers evaluated in NSCLC and discusses the role of their real-time detection in the clinical management of the disease.

Down-regulation of miR-452 is associated with poor prognosis in the non-small-cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) remains the most life-threatening cancer in the world. The aim of the current study was to investigate the value of miR-452 for the prognosis of patients with NSCLC.

METHODS

Real-time quantitative PCR (qRT-PCR) was used to test the expression level of miR-452 in 161 paired clinical NSCLC tissues and their adjacent tissues. Survival curves were made and the log rank test was used to analyze the survival difference between both groups with higher and lower expression level of miR-452. Univariate and multivariate Cox regression analyses were finally used to determine the independent factors for overall survival (OS) and disease-free survival (DFS) times.

RESULTS

The miR-452 expressions in tumor samples (n=161) were comparably lower than those in the adjacent tissues. miR-452 expression levels were significantly associated with tumor differentiation grade, tumor size and lymph nodes metastasis. Furthermore, Kaplan-Meier survival curves showed that patients with higher expression of miR-452 was confirmed to have more favorable OS (P=0.004) and DFS (P=0.026). Multivariate survival analysis verified that miR-452 expression level, as well as lymph nodes metastasis, was an independent predictor of both OS and DFS for NSCLC patients.

CONCLUSIONS

Our study demonstrated that miR-452 functioned as a novel diagnostic biomarker and a promising prognostic predictor for NSCLC patients.

ARHGEF15 overexpression worsens the prognosis in patients with pancreatic ductal adenocarcinoma through enhancing the motility and proliferative activity of the cancer cells

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive neoplastic diseases, associated with a remarkably poor prognosis. However, the molecular mechanisms underlying the development of PDAC remain elusive. The aim of this study was to identify genes whose expressions are correlated with a poor prognosis in PDAC patients, and to unravel the mechanisms underlying the involvement of these genes in the development of the cancer.

METHODS

Global gene expression profiling was conducted in 39 specimens obtained from Japanese patients with PDAC to identify genes whose expressions were correlated with a shorter overall survival. The effect of gene silencing or overexpression of ARHGEF15 in pancreatic cancer cell lines was examined by introducing siRNAs of ARHGEF15 or the ARHGEF15 expression vector. After assessing the effect of ARHGEF15 deregulation on the Rho-family proteins by pull-down assay, wound healing, transwell and cell viability assays were carried out to investigate the cellular phenotypes caused by the perturbation.

RESULTS

The global mRNA expression profiling revealed that overexpression of ARHGEF15, a Rho-specific GEF, was significantly associated with a poor prognosis in patients with PDAC. We also found that the depletion of ARHGEF15 by RNA interference in pancreatic cancer cell lines downregulated the activities of molecules of the Rho signaling pathway, including RhoA, Cdc42 and Rac1. Then, we also showed that ARHGEF15 silencing significantly reduced the motility and viability of the cells, while its overexpression resulted in the development of the opposite phenotype in multiple pancreatic cancer cell lines.

CONCLUSION

These data suggest that upregulation of ARHGEF15 contributes to the development of aggressive PDAC by increasing the growth and motility of the pancreatic cancer cells, thereby worsening the prognosis of these patients. Therefore, ARHGEF15 could serve as a novel therapeutic target in patients with PDAC.

Plasma miRNAs in predicting radiosensitivity in non-small cell lung cancer

Background

Radioresistance of thoracic radiotherapy is a major bottleneck in the treatment of non-small cell lung cancer (NSCLC). Until now, there have been no effective biomarkers to predict the radiosensitivity.

Purposes

Based on miRNA profile screened from NSCLC cell lines with different radiosensitivity, this study was conducted to explore the correlation between plasma miRNAs and radiotherapy response in NSCLC patients, and to identify biomarkers of the radiosensitivity in NSCLC.

Methods

Differentially expressed genes were acquired from time-series gene expression profiles of radioresistant H1299 and radiosensitive H460 lung cancer cells (GSE20549). Potential miRNAs were screened from these differentially expressed genes by combining bioinformatics with GO analysis, pathway analysis, and miRNA prediction. A clinical observational study was performed to explore the correlation between candidate miRNAs and radiotherapy response. Stage IIIa–IV NSCLC patients who received two to four cycles of previous chemotherapy and underwent thoracic radiotherapy alone were included. Total RNA was purified from peripheral blood before radiotherapy, and plasma miRNAs were detected by real-time PCR (qRT-PCR). Then, tumor response, progression-free survival (PFS), and overall survival (OS) were acquired. Four miRNAs significantly different between effective and ineffective groups were further analyzed to obtain cutpoints from receiver operating characteristic (ROC) curves and the predictive value of radiosensitivity.

Results

Candidate miRNAs included 14 miRNAs screened from radioresistant genes and five from radiosensitive genes. From Jan., 2013 to Dec., 2014, 54 eligible patients were enrolled with a median follow-up of 15.3 months (range 4.6 to 31.4) by the deadline of Aug. 31, 2015. Totally, there were no case of complete response (CR), 15 of partial response (PR), 35 of stable disease (SD), and 4 of progressive disease (PD). Eight patients had no progression and 19 patients were still alive. The median PFS and OS were 6.6 months (range 2.3 to 29.3) and 15.3 months (range 4.6 to 31.4), respectively. Four miRNAs (hsa-miR-98-5p, hsa-miR-302e, hsa-miR-495-3p, and hsa-miR-613) demonstrated a higher expression in effective group (CR + PR, 15 cases) than in ineffective group (SD + PD, 39 cases). Based on each cutpoint, objective response rate (ORR) was higher in miR-high group than in miR-low group. No miRNA showed correlation with median PFS or OS.

Conclusion

Bioinformatical analysis and clinical verification reveal the correlation between plasma miRNAs and radiosensitivity in NSCLC patients. Plasma miRNAs represent novel biomarkers to predict radiotherapy response clinically.

Electronic supplementary material

The online version of this article (doi:10.1007/s13277-016-5052-8) contains supplementary material, which is available to authorized users.

miR-98 targets ITGB3 to inhibit proliferation, migration, and invasion of non-small-cell lung cancer

Background

Accumulating evidence has emphasized causative links between aberrant microRNA (miR) expression patterns and cancer development. Abnormally expressed miRNA-98 (miR-98) was found in certain types of human cancers. The biological roles of miR-98 in lung cancer, however, remain largely undefined.

Methods

We evaluated the expression of miR-98 in normal lung tissues, lung cancer tissues, normal human bronchial epithelial cells, and lung cancer cells using quantitative real-time polymerase chain reaction. Effect of miR-98 on proliferation of lung cancer cells was investigated using MTT assay and colony formation assay. Transwell assay was used to assess the effects of miR-98 on migration and invasion of lung cancer cells. Whether miR-98 targets the 3′-untranslated region (3′-UTR) of integrin β3 (ITGB3) coding gene ITGB3 mRNA was ascertained using luciferase reporter assay. Finally, we transplanted miR-98 expressing A549 cells into nude mice to observe the effect of miR-98 on tumor growth in vivo.

Results

We confirmed that miR-98 was frequently low expressed in lung cancer tissues and human lung cancer cells. Reintroduction of miR-98 into lung cancer cells inhibited cell proliferation, migration, and invasion in vitro and suppressed tumor formation in a nude mouse model. Furthermore, we identified that miR-98 exerted inhibitory roles by directly binding to 3′-UTR of ITGB3 mRNA, thus negatively regulated the expression of ITGB3. Interestingly, upon restoring the expression of ITGB3, the effect of miR-98 on cell proliferation was partially reversed.

Conclusion

Our findings suggest that miR-98 prevents proliferation, migration, and invasion of lung cancer cells by directly binding to the 3′-UTR of ITGB3 mRNA and could be a promising treatment option in anticancer therapy.

miRNA detection methods and clinical implications in lung cancer

Lung cancer is the leading cause of cancer death worldwide. Therefore, advances in the diagnosis and treatment of the disease are urgently needed. miRNAs are a family of small, noncoding RNAs that regulate gene expression at the transcriptional level. miRNAs have been reported to be deregulated and to play a critical role in different types of cancer, including lung cancer. Thus, miRNA profiling in lung cancer patients has become the core of several investigations. To this end, the development of a multitude of platforms for miRNA profiling analysis has been essential. This article focuses on the different technologies available for assessing miRNAs and the most important results obtained to date in lung cancer.

MicroRNA-141 is a biomarker for progression of squamous cell carcinoma and adenocarcinoma of the lung: clinical analysis of 125 patients

Lung cancer is the most common malignant tumor worldwide. MicroRNA has become an ideal biomarker for cancer diagnosis, prognosis and therapy. The relationship between microRNA-141 and non-small cell lung cancer (NSCLC) is contradictory. Thus, in current study, we aimed to investigate the level of microRNA-141 in NSCLC tissues and to evaluate its potential clinical value. This study enrolled 125 NSCLC patients (75 males and 50 females) with a median age of 61 years (range, 23-90 years). NSCLC patients included 23 squamous cell carcinomas (SCCs), 101 adenocarcinomas (ADCs) and 1 large cell carcinoma. The expression level of microRNA-141 was significantly higher in NSCLC tissues than in adjacent lung tissues (P < 0.001), detected by real time RT-PCR. Receiver operating characteristic (ROC) exhibited a moderate diagnostic value of microRNA-141 for NSCLC with the area under curve of 0.707. The microRNA-141 expression increased with the larger tumor size (P = 0.002), lymph node metastasis (P = 0.018) and advanced stage (P = 0.022) in NSCLC patients. For subgroup analysis, microRNA-141 expression in SCC was correlated with tumor size (r = 0.490, P = 0.018), and in ADC, microRNA-141 level was positively associated with tumor size (r = 0.222, P = 0.026), lymph node metastasis (r = 0.242, P = 0.015) and TNM stage (r = 0.210, P = 0.035). Furthermore, univariate analysis revealed that the expression of microRNA-141 was an independent prognostic indicator of ADC. In conclusion, microRNA-141 is a potential biomarker for the molecular diagnosis and risk stratification of NSCLC.

An eight-miRNA signature as a potential biomarker for predicting survival in lung adenocarcinoma

BACKGROUND

Lung adenocarcinoma is a heterogernous disease that creates challenges for classification and management. The purpose of this study is to identify specific miRNA markers closely associated with the survival of LUAD patients from a large dataset of significantly altered miRNAs, and to assess the prognostic value of this miRNA expression profile for OS in patients with LUAD.

METHODS

We obtained miRNA expression profiles and corresponding clinical information for 372 LUAD patients from The Cancer Genome Atlas (TCGA), and identified the most significantly altered miRNAs between tumor and normal samples. Using survival analysis and supervised principal components method, we identified an eight-miRNA signature for the prediction of overall survival (OS) of LUAD patients. The relationship between OS and the identified miRNA signature was self-validated in the TCGA cohort (randomly classified into two subgroups: n = 186 for the training set and n = 186 for the testing set). Survival receiver operating characteristic (ROC) analysis was used to assess the performance of survival prediction. The biological relevance of putative miRNA targets was also analyzed using bioinformatics.

RESULTS

Sixteen of the 111 most significantly altered miRNAs were associated with OS across different clinical subclasses of the TCGA-derived LUAD cohort. A linear prognostic model of eight miRNAs (miR-31, miR-196b, miR-766, miR-519a-1, miR-375, miR-187, miR-331 and miR-101-1) was constructed and weighted by the importance scores from the supervised principal component method to divide patients into high- and low-risk groups. Patients assigned to the high-risk group exhibited poor OS compared with patients in the low-risk group (hazard ratio [HR] = 1.99, P <0.001). The eight-miRNA signature is an independent prognostic marker of OS of LUAD patients and demonstrates good performance for predicting 5-year OS (Area Under the respective ROC Curves [AUC] = 0.626, P = 0.003), especially for non-smokers (AUC = 0.686, P = 0.023).

CONCLUSIONS

We identified an eight-miRNA signature that is prognostic of LUAD. The miRNA signature, if validated in other prospective studies, may have important implications in clinical practice, in particular identifying a subgroup of patients with LUAD who are at high risk of mortality.