LncRNA PLAC 2 downregulated miR-21 in non-small cell lung cancer and predicted survival

microRNA 21 and long non-coding RNAs interplays underlie cancer pathophysiology: A narrative review

Non-coding RNAs (ncRNAs) are a diverse group of functional RNA molecules that lack the ability to code for proteins. Despite missing this traditional role, ncRNAs have emerged as crucial regulators of various biological processes and have been implicated in the development and progression of many diseases, including cancer. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are two prominent classes of ncRNAs that have emerged as key players in cancer pathophysiology. In particular, miR-21 has been reported to exhibit oncogenic roles in various forms of human cancer, including prostate, breast, lung, and colorectal cancer. In this context, miR-21 overexpression is closely associated with tumor proliferation, growth, invasion, angiogenesis, and chemoresistance, whereas miR-21 inactivation is linked to the regression of most tumor-related processes. Accordingly, miR-21 is a crucial modulator of various canonical oncogenic pathways such as PTEN/PI3K/Akt, Wnt/β-catenin, STAT, p53, MMP2, and MMP9. Moreover, interplays between lncRNA and miRNA further complicate the regulatory mechanisms underlying tumor development and progression. In this regard, several lncRNAs have been found to interact with miR-21 and, by functioning as competitive endogenous RNAs (ceRNAs) or miRNA sponges, can modulate cancer tumorigenesis. This work presents and discusses recent findings highlighting the roles and pathophysiological implications of the miR-21-lncRNA regulatory axis in cancer occurrence, development, and progression. The data collected indicate that specific lncRNAs, such as MEG3, CASC2, and GAS5, are strongly associated with miR-21 in various types of cancer, including gastric, cervical, lung, and glioma. Indeed, these lncRNAs are well-known tumor suppressors and are commonly downregulated in different types of tumors. Conversely, by modulating various mechanisms and oncogenic signaling pathways, their overexpression has been linked with preventing tumor formation and development. This review highlights the significance of these regulatory pathways in cancer and their potential for use in cancer therapy as diagnostic and prognostic markers.

Plasma Circulating Terminal Differentiation-Induced Non-Coding RNA Serves as a Biomarker in Breast Cancer

Background: Breast cancer is identified as the most common malignancy and cause of cancer-related death worldwide. Compared with healthy controls, this study evaluated the expression level and diagnostic power of lncRNA plasma TINCR in breast cancer patients. Materials and Methods: Fifty-eight women diagnosed with invasive ductal carcinoma and fifty healthy age- matched controls were included in the study. TRIzol® LS regent was used to isolate the total RNA from the whole plasma. Total RNA was converted to cDNA using Prime ScriptTM RT reagent kit and the expression levels of TINCR were quantified by qRT-PCR. Results: Low levels of TINCR lncRNA were observed in the plasma of breast cancer patients compared with control subjects. Plasma TINCR level was also positively correlated with the diagnostic age of breast cancer patients. Conclusion: A low level of plasma TINCR could discriminate breast cancer patients from healthy control subjects.

The role of selected non-coding RNAs in the biology of non-small cell lung cancer

Lung cancer is the second most frequently diagnosed cancer worldwide and a leading cause of cancer-related deaths. Non-small cell lung carcinoma (NSCLC) represents 85% of all cases. Accumulating evidence highlights the outstanding role of non-coding RNA (ncRNA) in regulating the tumorigenesis process by modulating crucial signaling pathways. Micro RNA (miRNA), long non-coding RNA (lncRNA) and circular RNA (circRNA) are either up- or downregulated in lung cancer patients and can promote or suppress the progression of the disease. These molecules interact with messenger RNA (mRNA) and with each other to regulate gene expression and stimulate proto-oncogenes or silence tumor suppressors. NcRNAs provide a new strategy to diagnose or treat lung cancer patients and multiple molecules have already been identified as potential biomarkers or therapeutic targets. The aim of this review is to summarize the current evidence on the roles of miRNA, lncRNA and circRNA in NSCLC biology and present their clinical potential.

Pre-clinical and clinical importance of miR-21 in human cancers: Tumorigenesis, therapy response, delivery approaches and targeting agents

The field of non-coding RNA (ncRNA) has made significant progress in understanding the pathogenesis of diseases and has broadened our knowledge towards their targeting, especially in cancer therapy. ncRNAs are a large family of RNAs with microRNAs (miRNAs) being one kind of endogenous RNA which lack encoded proteins. By now, miRNAs have been well-coined in pathogenesis and development of cancer. The current review focuses on the role of miR-21 in cancers and its association with tumor progression. miR-21 has both oncogenic and onco-suppressor functions and most of the experiments are in agreement with the tumor-promoting function of this miRNA. miR-21 primarily decreases PTEN expression to induce PI3K/Akt signaling in cancer progression. Overexpression of miR-21 inhibits apoptosis and is vital for inducing pro-survival autophagy. miR-21 is vital for metabolic reprogramming and can induce glycolysis to enhance tumor progression. miR-21 stimulates EMT mechanisms and increases expression of MMP-2 and MMP-9 thereby elevating tumor metastasis. miR-21 is a target of anti-cancer agents such as curcumin and curcumol and its down-regulation impairs tumor progression. Upregulation of miR-21 results in cancer resistance to chemotherapy and radiotherapy. Increasing evidence has revealed the role of miR-21 as a biomarker as it is present in both the serum and exosomes making them beneficial biomarkers for non-invasive diagnosis of cancer.

Expression of SOX2OT, DANCR and TINCR long non‑coding RNAs in papillary thyroid cancer and its effects on clinicopathological features

Long non‑coding RNAs (lncRNAs) are molecules that are >200 base pairs long and do not encode a protein. However, they perform important roles in regulating gene expression. Recent studies have revealed that the changes in the expressions of lncRNAs serve a role in the development and metastases of a number of types of cancer. A number of studies have been published on the association of SOX2 overlapping transcript (SOX2OT), differentiation antagonizing non‑protein coding RNA (DANCR) and tissue differentiation‑induced non‑coding RNA (TINCR) expression with various types of cancer. However, researchers have not yet studied their roles in papillary thyroid cancer or at least, those roles are not clarified. The aim of the present study was to investigate the expression and clinical significance of SOX2OT, DANCR and TINCR in papillary thyroid cancer (PTC). A total of 102 patients with PTC were included in the present study. Reverse transcription‑quantitative PCR method was used to determine the relative gene expression levels of lncRNAs and then the relationship between expressions of lncRNAs and clinical characteristics of the subjects was analyzed in detail. Expression levels of SOX2OT (P=0.016) and DANCR (P=0.017) increased in the tumor samples in contrast to the normal tissues. No significant difference was observed in the expression level of TINCR (P=0.298). In addition, SOX2OT expression was associated with micro carcinoma (P<0.001), tumor size (P=0.010) and primary tumor (P=0.006), while DANCR expression was associated with age (P=0.030) and micro carcinoma (P=0.004). The findings of the present study indicated that DANCR may contribute to the development of PTC while SOX2OT may contribute to both the development and progression of PTC.

LINC00184 plays an oncogenic role in non-small cell lung cancer via regulation of the miR-524-5p/HMGB2 axis

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. We aimed to investigate the role of LINC00184 in NSCLC. Migration, proliferation and invasion of NSCLC cells were analysed using the wound healing assay, cell counting kit-8 assay and transwell assay, respectively. Apoptosis and cell cycle were assessed using flow cytometry. Online bioinformatics tools were utilized to predict downstream microRNAs (miRNA) or genes related to LINC00184 expression. The RNA pull-down experiment and luciferase reporter assay were performed to verify the predictions thereof. LINC00184, miR-524-5p, and high mobility group 2 protein (HMGB2) expression levels in NSCLC tissues and cell lines were detected using quantitative real-time polymerase chain reaction. An NSCLC mouse model was constructed for in vivo experiments. LINC00184 overexpression was observed in NSCLC tissues and cell lines and was found to be correlated with poor prognosis. LINC00184 knockdown inhibited cell proliferation, migration and invasion, induced cell cycle arrest and accelerated apoptosis in NSCLC cell lines. LINC00184 suppressed tumour growth and proliferation in NSCLC mouse models and directly targeted the miR-524-5p/HMGB2 axis. Moreover, the expression levels of LINC00184 and HMGB2 were negatively correlated with miR-524-5p expression, whereas LINC00184 expression was positively correlated with HMGB2 expression. LINC00184 affected the cell cycle, proliferation, apoptosis, migration and invasion in NSCLC via regulation of the miR-524-5p/HMGB2 axis.

Linc8087 predicts favorable prognosis and inhibits cell migration and invasion in NSCLC

BACKGROUND

Non-small cell lung cancer (NSCLC) is the most common cancer and has poor prognosis. Long non-coding RNA(LncRNA) plays important roles in the regulation of cell migration in various types of cancer. In this study, we aimed to demonstrate the function of linc8087 in regulating cell migration and invasion in NSCLC cells.

METHODS

A lncRNA microarray was used to identify differentially expressed lncRNAs between NSCLC tissues and normal tissues. RT-qPCR was used to confirm the expression of linc8087 in tumor tissues. The association between linc8087 expression and clinicopathological characteristics was analyzed. RNA fluorescence in situ hybridization (FISH) was performed to observe the subcellular localization of linc8087. We investigated the effects of linc8087 expression on cell migration and invasion by wound healing assay, Transwell and invasion assays. The Human Tumor Metastasis RT² Profiler PCR Array was used to detect and analyze the mRNA levels of 84 genes involved in metastasis.

RESULTS

We found that linc8087 expression was obviously decreased in both NSCLC tissues and cell lines compared with paired normal tissues and a normal bronchial epithelium cell line. Low expression of linc8087 was significantly associated with poor survival. In addition, linc8087 was an independent risk factor for survival. Overexpressed linc8087 inhibited cell migration and invasion in A549 and PC9 cell lines. Knockdown of linc8087 promoted cell migration and invasion. The result of RT² Profiler PCR Array showed that overexpressed linc8087 upregulated the expression of the COL4A2, CST7 and FAT1 genes and led to the downregulation of SERPINE1.

CONCLUSIONS

These results indicate that linc8087 plays a key role in the progression of NSCLC, and it may serve as a meaningful prognostic biomarker as well as a latent therapeutic target in NSCLC patients.

The Common miRNAs between Tuberculosis and Non-Small Cell Lung Cancer: A Critical Review

Tuberculosis (TB) and non-small cell lung cancer (NSCLC) are two major contributors to mortality and morbidity worldwide. In this regard, TB and NSCLC have similar symptoms, and TB has symptoms that are identical to malignancy; therefore, sometimes it is mistakenly diagnosed as lung cancer. Moreover, patients with active pulmonary TB are at a higher risk of dying due to lung cancer. In addition, several signaling pathways involved in TB and NSCLC have been identified. Also, the miRNAs are biological molecules shown to play essential roles in the above-mentioned diseases through targeting the signaling pathways' genes. Most of the pathways affected by miRNAs are immune responses such as autophagy and apoptosis in TB and NSCLC, respectively. Several studies have separately investigated the expression of miRNAs profile in patients with NSCLC and infectious TB. In this critical review, we attempted to gather common miRNAs between TB and NSCLC and to explain the involved-pathways, which are affected by miRNAs in both TB and NSCLC. Results of this critical review show that the expressions of miR-155, miR-146a, miR-125b, miR-30a, miR-29a, and miR-Let7 have significantly changed in TB and NSCLC. The data suggest that miRNAs expression may provide a new method for screening or differential diagnosis of NSCLC and TB.

The ceRNA network of lncRNA and miRNA in lung cancer

Since lung cancer is a major causative for cancer-related deaths, the investigations for discovering biomarkers to diagnose at an early stage and to apply therapeutic strategies have been continuously conducted. Recently, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are being exponentially studied as promising biomarkers of lung cancer. Moreover, supportive evidence provides the competing endogenous RNA (ceRNA) network between lncRNAs and miRNAs participating in lung tumorigenesis. This review introduced the oncogenic or tumor-suppressive roles of lncRNAs and miRNAs in lung cancer cells and summarized the involvement of the lncRNA/miRNA ceRNA networks in carcinogenesis and therapeutic resistance of lung cancer.

TINCR: An lncRNA with dual functions in the carcinogenesis process

Long non-coding RNAs (lncRNAs) have prominent roles in the pathogenesis of human cancers. Several studies have shown oncogenic or tumor suppressor roles of lncRNAs in different human tissues. Thus, these transcripts have been regarded as putative targets in treatment of cancer. The lncRNA terminal differentiation-induced non-coding RNA (TINCR) has an especial position in this regard, as it exerts different opposite roles in the pathogenesis of different human cancers. While it is up-regulated in gastric, esophageal, bladder and breast cancer; it is down-regulated in glioma, retinoblastoma and prostate cancer. Notably, data regarding expression profile of this lncRNA in a number of human cancers such as colon cancer, squamous cell carcinoma, non-small cell lung cancer (NSCLC) and hepatocellular carcinoma (HCC) are controversial. Expression level of this lncRNA has been associated with clinical outcome in patients with gastric cancer, colorectal cancer, NSCLC and head and neck squamous cell carcinoma. Moreover, Kaplan-Meier analyses have shown correlation between expression levels of TINCR and patients survival in patients with lung cancer and HCC. A number of cellular pathways such as Wnt/β-catenin, ERK1/2‐SP3 and MAPK signaling pathways have been identified as targets of this lncRNA in different cancers. Moreover, the rs8113645, rs2288947 and rs8105637 within this lncRNA have been associated with risk of gastric and colorectal cancer. In conclusion, although the role of TINCR in the carcinogenesis is essential, based on the conflicting data regarding the direction of effect of this lncRNA, therapeutic targeting of this lncRNA is a complicated issue which should be considered in a tissue-specific or even individualized manner.

Upregulated lncRNA CASC9 Contributes to Progression of Non-Small Cell Lung Cancer Through Inhibition of miR-335-3p and Activation S100A14 Expression

Introduction

Non-small cell lung cancer (NSCLC) is a deadly cancer type worldwide and the main sub-type of lung cancer. Cancer susceptibility candidate-9 (CASC9) was reported to be a key player in cancer progression. However, its function and underlying mechanism in NSCLC remain unclear.

Materials and Methods

Expression level of CASC9 in NSCLC tissues and cells was measured with RT-qPCR. Biological roles of CASC9 in NSCLC were analyzed with a series of in vitro experiments. Potential mechanisms of CASC9 in NSCLC were analyzed by predicting and validating the possible targets of CASC9 in NSCLC.

Results

In this study, we found CASC9 expression was upregulated in NSCLC tissues and cell lines. High CASC9 expression was identified as a predictor for poorer overall survival of NSCLC patients. Furthermore, functional assays showed CASC9 knockdown suppressed NSCLC cell proliferation, migration, and invasion, while CASC9 overexpression caused opposite effects. We also found microRNA-335-3p (miR-335-3p) could act as a target of CASC9 in NSCLC and the inhibition effect of CASC9 knockdown on NSCLC progression required the activity of miR-335-3p. In addition, we identified S100 calcium-binding protein A14 (S100A14) acts as a target of miR-335-3p.

Discussion

Taken together, our study suggested CASC9 could promote NSCLC progression via miR-335-3p/S100A14 axis. The CASC9/miR-335-3p/S100A14 regulatory triplets identified in this work might provide new therapeutic strategies for NSCLC treatment.

LncRNA PLAC 2 Is Downregulated in Osteosarcoma and Regulates Cancer Cell Proliferation Through miR-93

Introduction

PLAC 2 is a tumor-suppressive lncRNA in glioma, while its roles in other types of cancer remain unclear. This study was carried out to explore the potential involvement of PLAC 2 in osteosarcoma (OS).

Methods

Expression levels of PLAC 2 in OS and paired non-tumor tissues from OS patients were determined by RT-qPCR. A follow-up study was performed to analyze the prognostic value of PLAC 2 for OS. Interactions between PLAC 2 and miR-93 were assessed by cell transfection, followed by RT-qPCR. Cell proliferation assay was performed to analyze cell proliferation.

Results

Our results showed that PLAC 2 was downregulated in OS tissues, and the high expression levels of PLAC 2 were associated with favorable overall survival of OS patients. MiR-93 was upregulated in OS tissues and its expression was inversely correlated with the expression of PLAC 2. In OS cells, overexpression of PLAC 2 resulted in downregulated miR-93, while overexpression of miR-93 did not affect the expression of PLAC 2. Overexpression of PLAC 2 led to decreased proliferation rate of OS cells, while overexpression of miR-93 showed opposite roles and reduced the overexpressing effects of PLAC 2.

Conclusion

PLAC 2 is downregulated in OS and regulates cancer cell proliferation through miR-93.