LncRNA DQ786243 contributes to proliferation and metastasis of colorectal cancer both in vitro and in vivo

Long non-coding RNAs as pathophysiological regulators, therapeutic targets and novel extracellular vesicle biomarkers for the diagnosis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic relapsing disease of the gastrointestinal (GI) system that includes two groups, Crohn's disease (CD) and ulcerative colitis (UC). To cope with these two classes of IBD, the investigation of pathogenic mechanisms and the discovery of new diagnostic and therapeutic approaches are crucial. Long non-coding RNAs (lncRNAs) which are non-coding RNAs with a length of longer than 200 nucleotides have indicated significant association with the pathology of IBD and strong potential to be used as accurate biomarkers in diagnosing and predicting responses to the IBD treatment. In the current review, we aim to investigate the role of lncRNAs in the pathology and development of IBD. We first describe recent advances in research on dysregulated lncRNAs in the pathogenesis of IBD from the perspective of epithelial barrier function, intestinal immunity, mitochondrial function, and intestinal autophagy. Then, we highlight the possible translational role of lncRNAs as therapeutic targets, diagnostic biomarkers, and predictors of therapeutic response in colon tissues and plasma samples. Finally, we discuss the potential of extracellular vesicles and their lncRNA cargo in the pathophysiology, diagnosis, and treatment of IBD.

Salivary expression of lncRNA DQ786243 and IL-17 in oral lichen planus: case-control study

Background

A growing number of studies has investigated IL-17 in OLP. However, its exact role and interactions are not fully determined. In addition, the literature investigating its salivary expression is limited. The scarcity in the literature studying lncRNAs was noticed, particularly with regards to correlating them with cytokines in OLP. In the current study, the salivary expression of lncRNA DQ786243 and IL-17 was assessed among different forms of OLP.

Methods

The study included 52 participants in four equal groups: reticular OLP, erythematous OLP, ulcerative OLP, and control group. All eligible OLP patients underwent conventional oral examination, along with basic charting of their demographic data, pain intensity using a visual analogue scale, and clinical evaluation using the Thongprasom et al. scale. The salivary expression of lncRNA DQ786243 and IL-17 was evaluated for all participants using qRT-PCR. Unstimulated whole saliva samples were used. Data were analyzed for statistical significance.

Results

No statistically significant difference was observed when comparing the mean age and gender distribution of the studied groups. A statistically significant difference was detected when comparing pain and clinical scores in the three OLP forms. The highest expression of both salivary biomarkers was noticed in ulcerative OLP, followed by erythematous OLP and reticular OLP, then the controls, with a significant difference between the studied groups. Upon comparing the salivary expression of DQ786243 in ulcerative and erythematous OLP, no significant difference was detected. No significant difference was detected when comparing salivary expression of IL-17 in erythematous OLP to the other OLP forms.

Conclusions

The salivary expression of lncRNA DQ786243 and IL-17 was upregulated in OLP compared to healthy individuals. Besides, their expression increased when the severity of OLP was at its highest level in ulcerative OLP. There was a positive correlation between DQ786243 and IL-17.

Trial registration The protocol was registered at ClinicalTrials.gov (NCT04503824). The date of registration is 07/08/2020.

lncRNA LINC01296 Promotes Oral Squamous Cell Carcinoma Development by Binding with SRSF1

Objective

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the head and neck, with strong local invasiveness and cervical lymph node metastasis. The purpose of this study was to investigate the role of LINC01296 in oral squamous cell carcinoma and its possible mechanism.

Materials and Methods

GEPAI database analysis and clinical samples were used to detect the expression of LINC01296 in head and neck cancer. In vivo experiment, MTT, clone formation assay, and transwell were used to detect the proliferation, migration, and invasion of oral squamous cell carcinoma. The effect of LINC01296 on EMT was detected by western blot and qRT-PCR to measure the expression of epithelial and mesenchymal phenotypic markers. BALB/c nude mice were used to carry out in vitro treatment experiment. In terms of mechanism, the binding relationship between LINC01296 and SRSF1 was predicted and verified by the RBPDB database and RNA pull-down assay.

Results

LINC01296 was highly expressed in clinical samples and cell lines of oral squamous cell carcinoma. Overexpression of LINC01296 promoted the proliferation, invasion, and migration of oral squamous cell carcinoma cells and accelerated the formation of xenografts, while silencing LINC01296 inhibited tumor progression. In mechanism, LINC01296 plays a tumor-promoting role by binding to SRSF1 protein.

Conclusion

LINC01296 promotes malignant lesions in oral squamous cell carcinoma by binding to SRSF1 protein, which provides important experimental data and theoretical basis for the prevention, diagnosis, and treatment of oral squamous cell carcinoma.

circ_0101802 functions as a sponge of miR-1236-3p to facilitate the proliferation, migration and invasion of colorectal cancer via regulating MACC1

Circular RNAs (circRNAs) have been shown to be involved in the progression of many diseases, including cancer. However, the role of circ_0101802 in the proliferation, migration and invasion of colorectal cancer (CRC) has not been studied. Our results showed that circ_0101802 was highly expressed in CRC tumor tissues and cells. Functional experiments suggested that circ_0101802 knockdown could inhibit the proliferation, migration and invasion of CRC cells in vitro and CRC tumorigenesis in vivo. In the terms of mechanism, we discovered that circ_0101802 could act as a sponge of miR-1236-3p, and miR-1236-3p could target MACC1. The rescue experiments revealed that miR-1236-3p inhibitor could reverse the inhibition effect of circ_0101802 silencing on CRC proliferation, migration and invasion, and MACC1 overexpression also could abolish the negative regulation of miR-1236-3p on CRC proliferation, migration and invasion. More important, our data confirmed that circ_0101802 sponged miR-1236-3p to positively regulate MACC1. In summary, our results revealed that circ_0101802 functioned as a tumor promoter in CRC, which could facilitate CRC proliferation, migration and invasion via regulating the miR-1236-3p/MACC1 axis.

LncRNA signature in colorectal cancer

Colorectal cancer (CRC) is among the most frequent cancers and is associated with high mortality particularly when being diagnosed in advanced stages. Although several environmental and intrinsic risk factors have been identified, the underlying cause of CRC is not clear in the majority of cases. Several studies especially in the recent decade have pointed to the role of epigenetic factors in this kind of cancer. Long non-coding RNAs (lncRNAs) as important contributors in the epigenetic mechanisms are involved in the initiation, progression and metastasis of CRC. Tens of oncogenic lncRNAs and a lower number of tumor suppressor lncRNAs have been recently identified to be dysregulated in CRC cells and tissues. Notably, expressions of a number of these transcripts have been dysregulated in serum samples of CRC patients, providing a non-invasive route for detection of this kind of cancer. The involvement of lncRNAs in the regulation of autophagy has provided them the ability to modulate response of CRC cells to chemotherapeutic modalities. In the current manuscript, we review the studies which evaluated the role of lncRNAs in the pathogenesis and progression of CRC to appraise their application as diagnostic/ prognostic markers.

Transcription factor forkhead box K1 regulates miR-32 expression and enhances cell proliferation in colorectal cancer

Increased microRNA (miR)-32 expression in colorectal cancer (CRC) tissues enhances CRC cell proliferation, migration, invasion and attenuates CRC cell apoptosis by repressing the expression of phosphatase and tensin homolog (PTEN). Forkhead box K1 (FOXK1) was identified as a potential interacting transcription factor using DNA pull-down assays and mass spectrometry. The present study aimed to elucidate the role of FOXK1 in regulating miR-32 expression in CRC. The expressions of FOXK1, miR-32, transmembrane protein 245 gene (TMEM245) and PTEN were compared between CRC and normal colonic tissues. Levels of miR-32, TMEM245, PTEN and the proliferation and apoptosis of CRC cells were studied using FOXK1-overexpression or knockdown, or by simultaneously interfering with FOXK1 and miR-32 expression. Direct FOXK1 binding to the miR-32 promoter was verified using chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays. The results showed elevated FOXK1, miR-32 and TMEM245 expression, and significantly decreased PTEN expression in CRC, compared with normal colonic tissues. Correlations between the expressions of TMEM245 and miR-32, FOXK1 and miR-32, and FOXK1 and TMEM245 were positive and significant. FOXK1-knockdown led to decreased miR-32 and TMEM245 expression and increased PTEN expression, whereas FOXK1-overexpression had the opposite effect. Overexpressed FOXK1 promoted the malignancy of CRC cells in vitro by stimulating proliferation and reducing apoptosis; whereas FOXK1-depletion suppressed such malignancy and a miR-32 inhibitor partially reversed the effects of FOXK1. The results of ChIP and dual-luciferase reporter assays indicated that FOXK1 directly binds to the promoter of TMEM245/miR-32. Thus, the FOXK1-miR-32-PTEN signaling axis may play a crucial role in the pathogenesis and development of CRC.

Lnc HAGLR Promotes Colon Cancer Progression Through Sponging miR-185-5p and Activating CDK4 and CDK6 in vitro and in vivo

BACKGROUND/AIM

LncRNA plays a key role in tumor progression. HAGLR functions as an oncogene in many cancers. However, the molecular mechanism of HAGLR in colon cancer is still unclear.

METHODS

qRT-PCR was used to measure the expression of HAGLR, miR-185-5p in colon cancer. The expression of CDK4 and CDK6 was detected by Western blot. CCK-8 assay, EdU staining, transwell and Annexin V-FITC/PI assay were used to analyze the effect of HAGLR and miR-185-5p on cell proliferation, invasion, migration and apoptosis. Bioinformatic analysis and luciferase were used to analyze the target genes of HAGLR and miR-185-5p. Nude mice were used to detect mouse tumor changes.

RESULTS

Compared with normal colon cancer tissues and cells, the expression of HAGLR was increased in colon cancer tissues and cells. In addition, the expression of HAGLR down-regulation inhibited the growth, migration, and invasion of colon cancer cells. MiR-185-5p was reduced in colon cancer, and CDK4 and CDK6 acted as target genes of miR-185-5p to regulate the progress of colon cancer. And CDK4 and CDK6 were predicted as downstream targets of miR-185-5p. Finally, it was demonstrated that HAGLR regulated tumor progression in vivo.

CONCLUSION

Lnc HAGLR promoted the development of colon cancer by miR-185-5p/CDK4/CDK6 axis, and lnc HAGLR might be potential target for colon cancer.

LncRNA CAR10 Upregulates PDPK1 to Promote Cervical Cancer Development by Sponging miR-125b-5p

Cervical cancer is one of the malignant tumors that seriously threaten women's health. The mechanism of development needs to be deeply studied. In recent years, lncRNA has been identified as one of the important factors affecting the malignant progression of tumors. In this study, we illustrated the important mechanism of lncRNA CAR10 in the development of cervical cancer. We found that CAR10 is significantly increased in4 cervical cancer tissues and cells, which can promote the proliferation of cervical cancer cells in vitro and in vivo, indicating that CAR10 is involved in the progression of cervical cancer as an oncogene. Further studies showed that CAR10 is a target gene of miR-125b-5p, and miR-125b-5p can inhibit the effect of CAR10 on the proliferation of cervical cancer cells. In addition, we also found that 3-phosphoinositide-dependent protein kinase 1 (PDPK1) is also a target gene of miR-125b-5p, and CAR10 can upregulate the expression level of PDPK1. The results showed that CAR10 acts as a ceRNA to upregulate the expression of PDPK1 by sponging miR-125b-5p. Knockdown of PDPK1 can inhibit the effect of CAR10 on cervical cancer cells. Our study demonstrates that, based on ceRNA mechanism, CAR10/miR-125b-5p/PDPK1 network can regulate the proliferation of cervical cancer cells and play an important role in the development of cervical cancer. In addition, our study also suggests that intervention of CAR10/miR-125b-5p/PDPK1 network may be a new strategy for targeted therapy of cervical cancer.

Long Noncoding RNA VIM Antisense RNA 1 (VIM-AS1) Plays an Important Role in Development of Preeclampsia by Regulation of Epithelial Mesenchymal Transition

Background

Long noncoding RNAs play important roles in the development of various diseases. This study aimed to evaluate the effects and mechanism of VIM antisense RNA 1 (VIM-AS1) in the development of preeclampsia.

Material/Methods

HTR-8/SVneo cells were divided into normal control (NC), Model, Blank, and VIM-AS1 groups. These groups were analyzed for their VIM-AS1 gene expressions by RT-PCR, HTR-8/SVneo cell invasion was assessed by transwell and migration by wound healing, cell morphology was assessed by microscopy examination, and E-cadherin, Snail, and Vimentin genes expressions were assessed by RT-PCR and WB assay.

Results

VIM-AS1 gene expression was significantly different among normal placenta tissue, mild preeclampsia tissues, and severe preeclampsia tissues (P<0.001 or P<0.01). VIM-AS1 gene expressions, cell invasions, and wound healing rates in the Model and Blank groups were significantly suppressed compared with that of NC group (P<0.001, all). With VIM-AS1 supplementation, VIM-AS1 gene expression, cell invasion, and wound healing rate in the VIM-AS1 group were significantly increased compared with that in the Model group (P<0.001). RT-PCR and WB assay showed that E-cadherin gene and protein expressions in Model and Blank groups were significantly upregulated compared with the NC group (P<0.001); Snail and Vimentin gene and protein expressions in the Model and Blank groups were significantly downregulated compared with the NC group (P<0.001). With VIM-AS1 supplementation, E-cadherin, Snail, and Vimentin gene and proteins expression levels in the VIM-AS1 group were significantly different compared with that in the Model group (P<0.001).

Conclusions

VIM-AS1 promotes preeclampsia via inducing epithelial-to-mesenchymal transition (EMT).

Diagnostic and prognostic potential of tissue and circulating long non-coding RNAs in colorectal tumors

Long non-coding RNAs (lncRNAs) are members of the non-protein coding RNA family longer than 200 nucleotides. They participate in the regulation of gene and protein expression influencing apoptosis, cell proliferation and immune responses, thereby playing a critical role in the development and progression of various cancers, including colorectal cancer (CRC). As CRC is one of the most frequently diagnosed malignancies worldwide with high mortality, its screening and early detection are crucial, so the identification of disease-specific biomarkers is necessary. LncRNAs are promising candidates as they are involved in carcinogenesis, and certain lncRNAs (e.g., CCAT1, CRNDE, CRCAL1-4) show altered expression in adenomas, making them potential early diagnostic markers. In addition to being useful as tissue-specific markers, analysis of circulating lncRNAs (e.g., CCAT1, CCAT2, BLACAT1, CRNDE, NEAT1, UCA1) in peripheral blood offers the possibility to establish minimally invasive, liquid biopsy-based diagnostic tests. This review article aims to describe the origin, structure, and functions of lncRNAs and to discuss their contribution to CRC development. Moreover, our purpose is to summarise lncRNAs showing altered expression levels during tumor formation in both colon tissue and plasma/serum samples and to demonstrate their clinical implications as diagnostic or prognostic biomarkers for CRC.

LINC00957 Acted as Prognostic Marker Was Associated With Fluorouracil Resistance in Human Colorectal Cancer

Colorectal cancer (CRC) is one of the most prevalent digestive tumors in China. Recent studies indicate that long intergenic non-coding RNAs (lincRNAs) play a crucial role in predicting survival for CRC patients. However, the novel lincRNA, LINC00957, is largely unclear in CRC. The purpose of the current study was to determine LINC00957 expression, assess its the clinical significance and explore the potential mechanism in CRC. The qRT-PCR was used to quantify the expression levels of LINC00957 in tissues and cell lines. Our research revealed that LINC00957 was significantly higher expression in CRC. In addition, the LINC00957 expression was associated with TNM stage and chemotherapy outcome, but age, gender, tumor size, histological grade, primary tumor location. CRC patients with high LINC00957 expression level showed poor overall survival (P = 0.002). Multivariate survival analysis indicated that LINC00957 was a prognostic factor for CRC patients (P = 0.010). Mechanically, inhibition of LINC00957 expression reversed 5-FU resistance by down-regulating P-gP. In summary, our study indicated that this novel lncRNA expression signature might be a useful biomarker of the prognosis and therapeutic target for CRC patients.

Downregulation of lncRNA CCAT1 enhances 5-fluorouracil sensitivity in human colon cancer cells

BACKGROUND

The purpose of this study was to determine the aberrant expression of the long noncoding RNA (lncRNA) colon cancer-associated transcript 1 (CCAT1) in 5-fluorouracil-resistant colonic neoplasm cells and to elucidate its effects on the 5-fluorouracil sensitivity of human colonic neoplasm cells. The aberrant expression of lncRNAs in normal tissues and colonic neoplasm tissues was detected by microarray assay. qRT-PCR analysis was performed to assess CCAT1 expression levels in colonic neoplasm cell lines and corresponding normal tissues. After constructing the 5-FU-resistant cell lines and validating the resistance by measuring the IC₅₀ value, the CCAT1 expression levels in parental and artificially resistant cell lines were determined by qRT-PCR. Transfection was used to modulate the expression of CCAT1. Cell proliferation and apoptosis were then detected by CCK-8 and flow cytometry, respectively.

RESULTS

CCAT1 in colon cancer tissues was higher than that in noncancer tissues, and the levels of CCAT1 in HCT 116, SW1417, HT-29, and KM12 cell lines were higher than those in the human normal colon epithelial NCM460 cell line. Moreover, the expression levels of CCAT1 were high in HCT 116/5-FU and HT-29/5-FU cell lines, whose apoptosis rates induced by 5-FU were lower than those in corresponding parental cells. The results of qRT-PCR and CCK-8 assay showed that enhancement of lncRNA CCAT1 expression levels in HCT 116 and HT-29 cell lines increased their IC₅₀ of 5-FU and decreased their apoptosis rates. Meanwhile, siRNA-CCAT1 effectively inhibited the expression of CCAT1 and enhanced the 5-FU-sensitivity of HCT 116/5-FU and HT-29/5-FU, in which apoptosis rates were increased at the same time.

CONCLUSIONS

Downregulation of CCAT1 effectively reversed the resistance of HCT 116/5-FU and HT-29/5-FU cells to 5-FU chemotherapeutic, opening a new avenue in colon cancer therapy.

The emerging role of lncRNAs in inflammatory bowel disease

Dysregulation of long noncoding RNA (lncRNA) expression is linked to the development of various diseases. Recently, an emerging body of evidence has indicated that lncRNAs play important roles in the pathogenesis of inflammatory bowel diseases (IBDs), including Crohn’s disease (CD) and ulcerative Colitis (UC). In IBD, lncRNAs have been shown to be involved in diverse processes, including the regulation of intestinal epithelial cell apoptosis, association with lipid metabolism, and cell–cell interactions, thereby enhancing inflammation and the functional regulation of regulatory T cells. In this review, we aim to summarize the current knowledge regarding the role of lncRNAs in IBD and highlight potential avenues for future investigation. We also collate potentially immune-relevant, IBD-associated lncRNAs identified through a built-by association analysis with respect to their neighboring protein-coding genes within IBD-susceptible loci. We further underscore their importance by highlighting their enrichment for various aspects of immune system regulation, including antigen processing/presentation, immune cell proliferation and differentiation, and chronic inflammatory responses. Finally, we summarize the potential of lncRNAs as diagnostic biomarkers in IBD.

Studying long noncoding RNAs (lncRNAs) may improve diagnosis and treatment of inflammatory bowel disease (IBD). These RNAs are found between genes in DNA regions previously thought to be “junk,” and have recently been shown to be important in development of various diseases. IBD, which includes both Crohn’s disease and ulcerative colitis, damages the digestive tract lining, causing pain and chronic diarrhea. A better understanding of IBD’s complex causes is needed to identify more effective treatments. Flemming Pociot at the Steno Diabetes Center in Gentofte, Denmark, and co-workers reviewed recent research linking lncRNAs and IBD. They discuss how lncRNAs’ roles in immunity and inflammation influence IBD development, describing how particular lncRNAs are related to IBD. Promising avenues for further research are highlighted, including the use of lncRNAs as biomarkers of IBD, which can be difficult to diagnose.

Long non-coding RNA expression in bladder cancer

The advent of novel high-throughput sequencing methods has facilitated identification of non-coding RNAs with fundamental roles in cellular biological and pathological conditions. A group of these consisting of at least 200 nucleotides are called long non-coding RNAs (lncRNAs). Their participation in the pathogenesis of cancer has been highlighted in recent years. Bladder cancer, one of the most prevalent cancers worldwide, exhibits altered expression levels of several lncRNAs. Several in vitro and in vivo studies have assessed the effects of silencing RNAs on cancer cell phenotypes and in vivo tumor growth. For instance, in vitro studies have shown that nuclear paraspeckle assembly transcript 1 (NEAT1), promoter of CDKN1A antisense DNA damage-activated RNA(PANDAR) and metastasis-associated lung adenocarcinoma transcript 1(MALAT1) have oncogenic effects while Maternally expressed 3 (MEG3) and BRAF activated non-coding RNA (BANCR) are tumor suppressors. Analysis of these data will help to identify a panel of lncRNAs that can be potentially used for both early detection and prognosis in bladder cancer patients. Here, we review the roles of several lncRNAs in the oncogenesis, tumor suppression, early detection, and prognosis of bladder cancer.

Downregulation of lncRNA OGFRP1 inhibits hepatocellular carcinoma progression by AKT/mTOR and Wnt/β-catenin signaling pathways

Introduction

Increasing evidence demonstrates that long noncoding RNAs (lncRNAs) play important roles in the progression of hepatocellular carcinoma (HCC) by regulating gene expression. However, the identification of functional lncRNAs in HCC remains insufficient. Our study aimed to investigate the function of lncRNA OGFRP1, which has not been functionally researched before, in Hep3B and HepG2 cells.

Methods

lncRNA OGFRP1 in HCC cells was down-regulated by using RNAi technology. Quantitative real-time polymerase chain reaction was used to determine the mRNA expression of lncRNA OGFRP1. Cell proliferation was examined by CCK8 and clone formation assays. Cell cycle and apoptosis were analyzed by flow cytometry. Cell migration and invasion were assessed by using Scratch assay and transwell assay, respectively. Protein expression of signaling pathways was determined by using Western blot.

Results

Cell proliferation of Hep3B was significantly inhibited by down-regulation of lncRNA OGFRP1 (P<0.05). Moreover, siOGFRP1 transfection induced Hep3B cell cycle arrest and apoptosis by regulating the expression of related proteins. Cell migration and invasion of Hep3B were also significantly inhibited by down-regulation of lncRNA OGFRP1. Wnt/β-catenin signaling pathway, involved in epithelial–mesenchymal transition (EMT), was inactivated by lncRNA OGFRP1 downregulation, including decreased expression of Wnt3a, β-catenin, N-cadherin and vimentin and increased expression of E-cadherin. We also found that the inhibitory effect of lncRNA OGFRP1 knockdown on Hep3B was mediated by the AKT/mTOR signaling pathway and IGF-1, an AKT signaling activator, could rescue the cellular phenotype. However, knockdown of lncRNA OGFRP1 did not influence cell proliferation, migration and invasion in HepG2 cells.

Conclusion

We found that downregulation of lncRNA OGFRP1 suppressed the proliferation and EMT of HCC Hep3B cells through AKT and Wnt/β-catenin signaling pathways. However, lncRNA OGFRP1 exhibited a differentiated function in different HCC cell lines, which required further study in the future.

Roles of long noncoding RNAs in colorectal cancer metastasis

Colorectal cancer (CRC) is the 3^rd most common malignancies worldwide. Metastasis is responsible for more than 90% CRC patients' death. Long noncoding RNAs (lncRNAs) are an important class of transcribed RNA molecules greater than 200 nucleotides in length. With the development of whole genome sequencing technologies, they have been gained more attention. Accumulating evidences suggest that abnormal expression of lncRNAs in diverse diseases are involved in various biological functions such as proliferation, apoptosis, metastasis and differentiation by acting as epigenetic, splicing, transcriptional or post-transcriptional regulators. Aberrant expression of lncRNAs has also been found in CRC. Besides, recent studies have indicated that lncRNAs play important roles in tumourigenesis and cancer metastasis. They participate in the process of metastasis by activing or inhibiting the metastatic pathways. However, their functions on the development of cancer metastasis are poorly understood. In this review, we highlight the findings of roles for lncRNAs in CRC metastasis and review the metastatic pathways of lncRNAs leading to cancer metastasis in CRC, including escape of apoptosis, epithelial-mesenchymal transition (EMT), angiogenesis and invasion, migration and proliferation. Furthermore, we also discuss the potential clinical application of lncRNAs in CRC as diagnostic markers and therapeutic targets.

Downregulation of the long non-coding RNA XLOC_010588 inhibits the invasion and migration of colorectal cancer

Long non-coding RNAs (lncRNAs) have emerged as major players in many biological and pathological processes; however, investigation into the function of lncRNAs in the development and progression of cancer is in its infancy. Therefore, clarification of the mechanism by which cancer-related lncRNAs function is of critical importance in research on tumorigenesis. It has been demonstrated that the lncRNA XLOC_010588 is expressed at a low level in cervical cancer, and that this has significant impact on the proliferation of cervical cancer cells. However, the expression pattern and functional roles of XLOC_010588 in colorectal cancer (CRC) remain unclear. In the present study, it was demonstrated that the expression of XLOC_010588 was significantly higher in CRC tissues when compared with that in adjacent normal tissues, and that XLOC_010588 was closely associated with metastasis and poor prognosis, thus indicating that XLOC_010588 may function as an oncogene. Additionally, downregulation of XLOC_010588 expression markedly inhibited the invasion and migration of CRC cells. Furthermore, it was demonstrated that XLOC_010588 may regulate the progression of CRC via the epithelial-mesenchymal transition (EMT) pathway. Notably, downregulation of XLOC_010588 inhibited the invasion and migration of CRC cells by regulating genes associated with EMT. Our findings revealed that XLOC_010588 may be considered as a novel potential diagnostic biomarker in CRC.

microRNAs and Acute Myeloid Leukemia Chemoresistance: A Mechanistic Overview

Up until the early 2000s, a functional role for microRNAs (miRNAs) was yet to be elucidated. With the advent of increasingly high-throughput and precise RNA-sequencing techniques within the last two decades, it has become well established that miRNAs can regulate almost all cellular processes through their ability to post-transcriptionally regulate a majority of protein-coding genes and countless other non-coding genes. In cancer, miRNAs have been demonstrated to play critical roles by modifying or controlling all major hallmarks including cell division, self-renewal, invasion, and DNA damage among others. Before the introduction of anthracyclines and cytarabine in the 1960s, acute myeloid leukemia (AML) was considered a fatal disease. In decades since, prognosis has improved substantially; however, long-term survival with AML remains poor. Resistance to chemotherapy, whether it is present at diagnosis or induced during treatment is a major therapeutic challenge in the treatment of this disease. Certain mechanisms such as DNA damage response and drug targeting, cell cycling, cell death, and drug trafficking pathways have been shown to be further dysregulated in treatment resistant cancers. miRNAs playing key roles in the emergence of these drug resistance phenotypes have recently emerged and replacement or inhibition of these miRNAs may be a viable treatment option. Herein, we describe the roles miRNAs can play in drug resistant AML and we describe miRNA-transcript interactions found within other cancer states which may be present within drug resistant AML. We describe the mechanisms of action of these miRNAs and how they can contribute to a poor overall survival and outcome as well. With the precision of miRNA mimic- or antagomir-based therapies, miRNAs provide an avenue for exquisite targeting in the therapy of drug resistant cancers.

Upregulation of long non-coding RNA DQ786243 promotes the progression of gastric cancer

Long non-coding RNAs (lncRNAs) have been identified as key regulatory factors in various biological processes. Their dysregulation has been observed in several types of human cancer, including gastric cancer (GC). The aim of the present study was to investigate the putative roles of the lncRNA DQ786243 in the progression of GC, as well as evaluate its diagnostic and therapeutic potential in GC. The expression of DQ786243 in 82 pairs of GC tissues and adjacent healthy tissues, as well as in three GC cell lines and a human normal gastric epithelial cell line, was assessed using reverse transcription-quantitative polymerase chain reaction. In addition, the putative correlation between the expression of DQ786243 and various clinicopathological features of GC was investigated. Furthermore, the effects of silencing DQ786243 in GC cells were examined using RNA interference. Colony formation and Cell Counting kit-8 assays were used to evaluate the effects of DQ786243 on GC cell proliferation, and Transwell and wound healing assays were used to examine GC cell migration and invasion. The results of the present study demonstrated that the expression of DQ786243 was significantly upregulated in GC tissues and cell lines compared with healthy control tissues and cells. Correlation analysis revealed a significant association between the expression of DQ786243 and the TNM stage, tumor size, depth of invasion and presence of lymph node metastasis in patients with GC. Furthermore, silencing the DQ786243 was demonstrated to inhibit proliferation, and impair the migration and invasion of GC cells. The present results suggested that DQ786243 may function as an oncogenic regulator via promoting the proliferation and metastasis of GC cells. Therefore, DQ786243 may have potential as a novel biomarker for the diagnosis of GC, and may also be a promising candidate for the development of novel therapeutic approaches for the treatment of patients with GC.

Noncoding RNAs in the development, diagnosis, and prognosis of colorectal cancer

More than 90% of the human genome is actively transcribed, but less than 2% of the total genome encodes protein-coding RNA, and thus, noncoding RNA (ncRNA) is a major component of the human transcriptome. Recently, ncRNA was demonstrated to play important roles in multiple biological processes by directly or indirectly interfering with gene expression, and the dysregulation of ncRNA is associated with a variety of diseases, including cancer. In this review, we summarize the function and mechanism of miRNA, long intergenic ncRNA, and some other types of ncRNAs, such as small nucleolar RNA, circular ncRNA, pseudogene RNA, and even protein-coding mRNA, in the progression of colorectal cancer (CRC). We also presented their clinical application in the diagnosis and prognosis of CRC. The summary of the current state of ncRNA in CRC will contribute to our understanding of the complex processes of CRC initiation and development and will help in the discovery of novel biomarkers and therapeutic targets for CRC diagnosis and treatment.

LncRNA GAS5 contributes to lymphatic metastasis in colorectal cancer

Colorectal cancer (CRC) ranks the third most common type of cancer worldwide. However, the detailed molecular mechanisms underlying these processes are poorly understood. Recent studies have shown that lncRNAs play important roles in carcinogenesis and progression of CRC. The lncRNA growth arrest special 5 (GAS5), was previously identified to be down-regulated and functions as a tumor suppressor gene in many kinds of cancers. In current two-stage, case-control study, we systematically evaluated the potential role of lncRNA GAS5 and its genetic variation rs145204276 in the development and metastasis process of CRC in a Chinese population. We found the allele del of rs145204276 was significantly associated with 21% decreased risk of CRC (OR=0.79; 95% CI=0.70-0.89; P value = 5.21×10-5). Compared with the genotype ins/ins, both the genotype ins/del (OR=0.78; 95% CI=0.68-0.91) and del/del (OR=0.64; 95% CI=0.49-0.84) showed decreased susceptibility. For both in colon and rectum cancers, the associations kept statistically significant (OR=O.78 and 0.80, while P value = 4.56×10-4, and 3.80×10-3, respectively). The results also showed that the carriers of allele del are less likely to get lymph node metastasis (OR=0.80; 95% CI=0.68-0.95; P value = 0.010). Taken together, our findings provided strong evidence for the hypothesis that GAS5 rs145204276 were significantly associated with the susceptibility and progression of CRC.

Microarray analysis reveals a potential role of LncRNAs expression in cardiac cell proliferation

Background

Long non-coding RNAs (LncRNAs) have been identified to play important roles in epigenetic processes that underpin organogenesis. However, the role of LncRNAs in the regulation of transition from fetal to adult life of human heart has not been evaluated.

Methods

Immunofiuorescent staining was used to determine the extent of cardiac cell proliferation. Human LncRNA microarrays were applied to define gene expression signatures of the fetal (13–17 weeks of gestation, n = 4) and adult hearts (30–40 years old, n = 4). Pathway analysis was performed to predict the function of differentially expressed mRNAs (DEM). DEM related to cell proliferation were selected to construct a lncRNA-mRNA co-expression network. Eight lncRNAs were confirmed by quantificational real-time polymerase chain reaction (n = 6).

Results

Cardiac cell proliferation was significant in the fetal heart. Two thousand six hundred six lncRNAs and 3079 mRNAs were found to be differentially expressed. Cell cycle was the most enriched pathway in down-regulated genes in the adult heart. Eight lncRNAs (RP11-119 F7.5, AX747860, HBBP1, LINC00304, TPTE2P6, AC034193.5, XLOC_006934 and AL833346) were predicted to play a central role in cardiac cell proliferation.

Conclusions

We discovered a profile of lncRNAs differentially expressed between the human fetal and adult heart. Several meaningful lncRNAs involved in cardiac cell proliferation were disclosed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12861-016-0139-4) contains supplementary material, which is available to authorized users.