MAP3K4 kinase action and dual role in cancer

It is commonly known that the MAPK pathway is involved in translating environmental inputs, regulating downstream reactions, and maintaining the intrinsic dynamic balance. Numerous essential elements and regulatory processes are included in this pathway, which are essential to its functionality. Among these, MAP3K4, a member of the serine/threonine kinases family, plays vital roles throughout the organism's life cycle, including the regulation of apoptosis and autophagy. Moreover, MAP3K4 can interact with key partners like GADD45, which affects organism's growth and development. Notably, MAP3K4 functions as both a tumor promotor and suppressor, being activated by a variety of factors and triggering diverse downstream pathways that differently influence cancer progression. The aim of this study is to provide a brief overview of physiological functions of MAP3K4 and shed light on its contradictory roles in tumorigenesis.

Targeting PI3K/AKT/mTOR and MAPK Signaling Pathways in Gastric Cancer

Gastric cancer (GC) is the fourth leading cause of death worldwide, with more than 1 million cases diagnosed every year. Helicobacter pylori represents the main risk factor, being responsible for 78% of the cases. Increased amounts of salt, pickled food, red meat, alcohol, smoked food, and refined sugars negatively affect the stomach wall, contributing to GC development. Several gene mutations, including PIK3CA, TP53, ARID1A, CDH1, Ras, Raf, and ERBB3 are encountered in GC pathogenesis, leading to phosphatidylinositol 3-kinase (PI3K) protein kinase B (AKT)/mammalian target of rapamycin (mTOR)-PI3K/AKT/mTOR-and mitogen-activated protein kinase (MAPK) signaling pathway activation and promoting tumoral activity. Helicobacter pylori, growth factors, cytokines, hormones, and oxidative stress also activate both pathways, enhancing GC development. In clinical trials, promising results have come from monoclonal antibodies such as trastuzumab and ramucirumab. Dual inhibitors targeting the PI3K/AKT/mTOR and MAPK signaling pathways were used in vitro studies, also with promising results. The main aim of this review is to present GC incidence and risk factors and the dysregulations of the two protein kinase complexes together with their specific inhibitors.

Unraveling the mechanisms of intervertebral disc degeneration: an exploration of the p38 MAPK signaling pathway

Intervertebral disc (IVD) degeneration (IDD) is a worldwide spinal degenerative disease. Low back pain (LBP) is frequently caused by a variety of conditions brought on by IDD, including IVD herniation and spinal stenosis, etc. These conditions bring substantial physical and psychological pressure and economic burden to patients. IDD is closely tied with the structural or functional changes of the IVD tissue and can be caused by various complex factors like senescence, genetics, and trauma. The IVD dysfunction and structural changes can result from extracellular matrix (ECM) degradation, differentiation, inflammation, oxidative stress, mechanical stress, and senescence of IVD cells. At present, the treatment of IDD is basically to alleviate the symptoms, but not from the pathophysiological changes of IVD. Interestingly, the p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway is involved in many processes of IDD, including inflammation, ECM degradation, apoptosis, senescence, proliferation, oxidative stress, and autophagy. These activities in degenerated IVD tissue are closely relevant to the development trend of IDD. Hence, the p38 MAPK signaling pathway may be a fitting curative target for IDD. In order to better understand the pathophysiological alterations of the intervertebral disc tissue during IDD and offer potential paths for targeted treatments for intervertebral disc degeneration, this article reviews the purpose of the p38 MAPK signaling pathway in IDD.

Vinorelbine Alters lncRNA Expression in Association with EGFR Mutational Status and Potentiates Tumor Progression Depending on NSCLC Cell Lines' Genetic Profile

Lung cancer remains the leading cause of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) as the most common type. In addition, NSCLC has a high mortality rate and an overall adverse patient outcome. Although significant improvements have been made in therapeutic options, effectiveness is still limited in late stages, so the need for a better understanding of the genomics events underlying the current therapies is crucial to aid future drug development. Vinorelbine (VRB) is an anti-mitotic chemotherapy drug (third-generation vinca alkaloid) used to treat several malignancies, including NSCLC. However, despite its widespread clinical use, very little is known about VRB-associated genomic alterations in different subtypes of NSCLC. This article is an in vitro investigation of the cytotoxic effects of VRB on three different types of NSCLC cell lines, A549, Calu-6, and H1792, with a closer focus on post-treatment genetic alterations. Based on the obtained results, VRB cytotoxicity produces modifications on a cellular level, altering biological processes such as apoptosis, autophagy, cellular motility, cellular adhesion, and cell cycle, but also at a genomic level, dysregulating the expression of some coding genes, such as EGFR, and long non-coding RNAs (lncRNAs), including CCAT1, CCAT2, GAS5, MALAT1, NEAT1, NORAD, XIST, and HOTAIR, that are implicated in the mitogen-activated protein kinase (MAPK) signaling pathway. Therefore, although extensive validation is required, these results pave the way towards a better understanding of the cellular and genomic alterations underlying the cytotoxicity of VRB.

Role of lncRNAs in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is among the deadliest cancer in human malignancies. It is the most common and severe type of primary liver cancer. However, the molecular mechanisms underlying HCC pathogenesis remain poorly understood. Long non-coding RNAs (lncRNAs), a new kind of RNA and epigenetic factors, play a crucial role in tumorigenesis and the progression of HCC. LncRNAs are capable of promoting the autophagy, proliferation, and migration of tumor cells by targeting and modulating the expression of downstream genes in signaling pathways related to cancer; these transcripts modify the activity and expression of various tumor suppressors and oncogenes. LncRNAs could act as biomarkers for treatment approaches such as immunotherapy, chemotherapy, and surgery to effectively treat HCC patients. Improved knowledge regarding the aetiology of HCC may result from an advanced understanding of lncRNAs. Enhanced oxidative stress in the mitochondrial and Endoplasmic reticulum leads to the activation of unfolded protein response pathway that plays a crucial role in the pathophysiology of hepatocellular carcinoma. The mutual regulation between LncRNAs and Endoplasmic reticulum (ER) stress in cancer and simultaneous activation of the unfolded protein response (UPR) pathway determines the fate of tumor cells in HCC. Mitochondria-associated lncRNAs work as essential components of several gene regulatory networks; abnormal regulation of mitochondria-associated lncRNAs may lead to oncogenesis, which provides further insight into the understanding of tumorigenesis and therapeutic strategies.

LINC00628 is differentially expressed between lung adenocarcinoma and squamous cell carcinoma and is associated with the prognosis of NSCLC

Non-small cell lung cancer (NSCLC) remains the most frequent malignancy worldwide, and lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) represent two major subtypes. LINC00628 has been demonstrated to promote LUAD progression; however, its clinical role in NSCLC remains elusive. The aim of the present study was to analyze the expression of long intergenic non-protein coding RNA 628 (LINC00628) in NSCLC, including in the LUAD and LUSC subtypes. In addition, its roles in NSCLC development and prognosis were also examined. Data from The Cancer Genome Atlas (TCGA) database were first used to assess the expression and prognostic potential in both LUAD and LUSC, then LINC00628 expression in 128 NSCLC tissues was measured using reverse transcription-quantitative PCR. A receiver operating characteristic curve was used to assess the ability of LINC00628 to discriminate between patients with LUAD and LUSC. Kaplan-Meier curves were used to analyze the relationship between LINC00628 expression and the overall survival of patients. Cox regression analysis was used to explore the potential prognostic factors that might be independently associated with NSCLC overall survival. Both in silico and tissue analysis data indicated that the expression of LINC00628 was significantly upregulated in NSCLC tissue compared with matched normal controls (P<0.001). LINC00628 expression levels were also significantly higher in LUAD cases than in patients with LUSC (P<0.001). In addition, LINC00628 could discriminate LUAD from LUSC cases. The expression of LINC00628 was significantly associated with tumor size (P=0.013), histological type (P=0.009), lymph node metastasis (P=0.021) and TNM stage (P=0.008). Survival analysis based on data from both TCGA and patients included in the present study identified an association between LINC00628 and overall survival in LUAD, but this relationship was not observed in LUSC for TCGA data. Cox regression analysis demonstrated that high LINC00628 expression was associated with poor overall survival in patients with LUAD (P=0.001), but not in patients with LUSC (P=0.088). In conclusion, LINC00628 expression was upregulated in NSCLC and associated with patient prognosis. Patients with LUAD had higher LINC00628 expression levels than those with LUSC, and increased LINC00628 served as an independent prognostic factor in LUAD, but not LUSC.

A fourteen-lncRNA risk score system for prognostic prediction of patients with non-small cell lung cancer

Growing evidence has underscored long non-coding RNAs (lncRNAs) serving as potential biomarkers for cancer prognosis. However, systematic tracking of a lncRNA signature for prognosis prediction in non-small cell lung cancer (NSCLC) has not been accomplished yet. Here, comprehensive analysis with differential gene expression analysis, univariate and multivariate Cox regression analysis based on The Cancer Genome Atlas (TCGA) database was performed to identify the lncRNA signature for prediction of the overall survival of NSCLC patients. A risk-score model based on a 14-lncRNA signature was identified, which could classify patients into high-risk and low-risk groups and show poor and improved outcomes, respectively. The receiver operating characteristic (ROC) curve revealed that the risk-score model has good performance with high AUC value. Multivariate Cox's regression model and stratified analysis indicated that the risk-score was independent of other clinicopathological prognostic factors. Furthermore, the risk-score model was competent for the prediction of metastasis-free survival in NSCLC patients. Moreover, the risk-score model was applicable for prediction of the overall survival in the other 30 caner types of TCGA. Our study highlighted the significant implications of lncRNAs as prognostic predictors in NSCLC. We hope the lncRNA signature could contribute to personalized therapy decisions in the future.

Interaction between non-coding RNAs and JNK in human disorders

Jun N-terminal Kinase (JNK) signaling pathway is a conserved cascade among species with particular roles in diverse processes during embryogenesis and normal life. These kinases regulate functions of neurons and the immune system by affecting the expression of genes, modulating the arrangement of cytoskeletal proteins, and regulating apoptosis/survival pathways. They are also involved in carcinogenesis. Several miRNAs and lncRNAs have a functional relationship with JNKs. This interaction contributes to the pathogenesis of traumatic brain injury, ulcerative colitis, hepatic ischemia/ reperfusion injury, acute myocardial infarction, and a number of other disorders. Lung cancer, hepatocellular carcinoma, gall bladder cancer, melanoma, and colon cancer are among malignant conditions in which JNK-related miRNAs/ lncRNAs contribute. The current review aims at depicting the functional interaction between JNKs and lncRNAs/ miRNAs and describing the role of these regulatory transcripts in the pathobiology of human disorders.

Upregulated hsa_circ_0000129 expression promotes proliferation and migration of breast cancer cells

Circular RNAs (circRNAs) are considered potential biomarkers in the pathogenesis and detection of several types of cancer. The present study aimed to investigate the role of hsa_circ_0000129 in the pathogenesis and molecular mechanism underlying breast cancer. A total of 68 pairs of breast cancer and corresponding paracancerous tissue samples, three different breast cancer cell lines (MCF-7, MDA-MB-231 and MDA-MB-468) and a normal human breast cell line (MCF-10A) were used to investigate the expression of hsa_circ_0000129. The effect of hsa_circ_0000129 on cell proliferation, migration and colony formation was assessed in MCF-7 and MDA-MB-468 cells, along with the expression of enhancer of zeste homolog 2 (EZH2). The results demonstrated that hsa_circ_0000129 expression was significantly higher in breast cancer tissues compared with normal tissues. In addition, high hsa_circ_0000129 expression was significantly associated with lymph node metastasis and a higher tumor-node-metastasis stage. Comparisons between the breast cancer cell lines (MCF-7, MDA-MB-231 and MDA-MB-468) and MCF-10A cells indicated similar results. MCF-7 cells overexpressed with hsa_circ_0000129 significantly increased cell proliferation, migration and colony formation compared with the negative control group, the effects of which were reversed following hsa_circ_0000129 knockdown in MDA-MB-468 cells. Furthermore, EZH2 expression was positively associated with hsa_circ_0000129 expression. Taken together, the results of the present study suggest that hsa_circ_0000129 may represent a promising prognostic biomarker for breast cancer. In addition, the role of hsa_circ_0000129 in breast cancer cell lines indicates a mechanism for tumorigenesis, as well as a potent target for the treatment of malignant progression.

Long Noncoding RNA HITTERS Protects Oral Squamous Cell Carcinoma Cells from Endoplasmic Reticulum Stress-Induced Apoptosis via Promoting MRE11-RAD50-NBS1 Complex Formation

Recent studies have proven that long noncoding RNAs (lncRNAs) exhibit regulatory functions of both DNA damage response (DDR) and endoplasmic reticulum (ER) stress. Herein, ER stress-induced lncRNA transcriptomic changes are reported in human oral squamous cell carcinoma (OSCC) cells and a novel lncRNA HITTERS ( H ERPUD1 intronic transcript of ER stress) is identified as the most significantly upregulated lncRNA. It is shown that HITTERS is a nucleus-located lncRNA including two transcript variants. HITTERS lacks an independent promoter but shares the same promoter with HERPUD1. HITTERS is transcriptionally regulated by Activating Transcription Factor (ATF) 6, ATF4, X-Box Binding Protein 1 (XBP1), and DNA methylation. In human OSCC tissues, HITTERS is significantly correlated with OSCC clinicopathological features and prognosis. Gain- and loss-of-function studies reveal that HITTERS promotes OSCC proliferation and invasion via influencing the expression of growth factor receptors and the downstream pathways. Once ER stress is triggered, HITTERS significantly attenuates ER stress-induced apoptosis both in vivo and in vitro. Mechanically, HITTERS functions as RNA scaffold to promote MRE11-RAD50-NBS1 complex formation in the repair of ER stress-induced DNA damage. To sum up, this study presents a novel lncRNA, namely HITTERS, which links ER stress and DDR together in OSCC.

Role of taurine, its haloamines and its lncRNA TUG1 in both inflammation and cancer progression. On the road to therapeutics? (Review)

For one century, taurine is considered as an end product of sulfur metabolism. In this review, we discuss the beneficial effect of taurine, its haloamines and taurine upregulated gene 1 (TUG1) long non‑coding RNA (lncRNA) in both cancer and inflammation. We outline how taurine or its haloamines (N‑Bromotaurine or N‑Chlorotaurine) can induce robust and efficient responses against inflammatory diseases, providing insight into their molecular mechanisms. We also provide information about the use of taurine as a therapeutic approach to cancer. Taurine can be combined with other chemotherapeutic drugs, not only mediating durable responses in various malignancies, but also circumventing the limitations met from chemotherapeutic drugs, thus improving the therapeutic outcome. Interestingly, the lncRNA TUG1 is regarded as a promising therapeutic approach, which can overcome acquired resistance of cancer cells to selected strategies. In this regard, we can translate basic knowledge about taurine and its TUG1 lncRNA into potential therapeutic options directed against specific oncogenic signaling targets, thereby bridging the gap between bench and bedside.

LINC00858 knockdown inhibits gastric cancer cell growth and induces apoptosis through reducing WNK2 promoter methylation

BACKGROUND

Emerging evidence indicates a regulatory role of long non-coding RNAs (lncRNAs) in the development of gastric cancer (GC), but the mechanisms underlying their function have remained largely unknown. Recent microarray-based expression profiling has led to the identification of a novel differentially expressed lncRNA, LINC00858, in GC. Subsequently, LINC00858 was found to be highly expressed in GC tissues and cells. This study was designed to clarify the functional role of LINC00858 in GC, including its effect on methylation of the WNK2 gene promoter and its downstream MAPK signaling pathway.

METHODS

After exogenous over-expression and knockdown of LINC00858 and the addition of a MAPK pathway inhibitor in GC cells, we explored the effects of LINC00858 and the MAPK signaling pathway on GC cell behavior using various in vitro and in vivo assays.

RESULTS

LINC00858 was found to negatively regulate WNK2 expression by enhancing its promoter methylation and to activate the MAPK signaling pathway. Moreover, we found that knockdown of LINC00858 or inhibition of the MAPK signaling pathway resulted in decreased GC cell growth, migration and invasion, as well as decreased cell cycle progression, along with increased apoptosis and decreased tumorigenicity.

CONCLUSIONS

Together, these findings indicate that silencing of LINC00858 increases WNK2 expression and inhibits the MAPK signaling pathway, thereby inhibiting GC growth and development. Our data highlight LINC00858 as a potential target in GC therapy.

In silico identification of MAPK14-related lncRNAs and assessment of their expression in breast cancer samples

Mitogen-activated protein kinase (MAP kinase) pathways participate in regulation of several cellular processes involved in breast carcinogenesis. A number of non-coding RNAs including both microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) regulate or being regulated by MAPKs. We performed an in-silico method for identification of MAPKs with high number of interactions with miRNAs and lncRNAs. Bioinformatics approaches revealed that MAPK14 ranked first among MAPKs. Subsequently, we identified miRNAs and lncRNAs that were predicted to be associated with MAPK14. Finally, we selected four lncRNAs with higher predicted scores (NORAD, HCG11, ZNRD1ASP and TTN-AS1) and assessed their expression in 80 breast cancer tissues and their adjacent non-cancerous tissues (ANCTs). Expressions of HCG11 and ZNRD1ASP were lower in tumoral tissues compared with ANCTs (P values < 0.0001). However, expression levels of MAPK14 and NORAD were not significantly different between breast cancer tissues and ANCTs. A significant association was detected between expression of HCG11 and estrogen receptor (ER) status in a way that tumors with up-regulation of this lncRNA were mostly ER negative (P value = 0.04). Expressions of ZNRD1ASP and HCG11 were associated with menopause age and breast feeding duration respectively (P values = 0.02 and 0.04 respectively). There was a trend towards association between ZNRD1ASP expression and patients' age of cancer diagnosis. Finally, we detected a trend toward association between expression of NORAD and history of hormone replacement therapy (P value = 0.06). Expression of MAPK14 was significantly higher in grade 1 tumors compared with grade 2 tumors (P value = 0.02). Consequently, the current study provides evidences for association between lncRNA expressions and reproductive factors or tumor features.

MAP Kinases Pathways in Gastric Cancer

Gastric cancer (GC) is turning out today to be one of the most important welfare issues for both Asian and European countries. Indeed, while the vast majority of the disease burden is located in China and in Pacific and East Asia, GC in European countries still account for about 100,000 deaths per year. With this review article, we aim to focus the attention on one of the most complex cellular pathways involved in GC proliferation, invasion, migration, and metastasis: the MAP kinases. Such large kinases family is to date constantly studied, since their discovery more than 30 years ago, due to the important role that it plays in the regulation of physiological and pathological processes. Interactions with other cellular proteins as well as miRNAs and lncRNAs may modulate their expression influencing the cellular biological features. Here, we summarize the most important and recent studies involving MAPK in GC. At the same time, we need to underly that, differently from cancers arising from other tissues, where MAPK pathways seems to be a gold target for anticancer therapies, GC seems to be unique in any aspect. Our aim is to review the current knowledge in MAPK pathways alterations leading to GC, including H. pylori MAPK-triggering to derail from gastric normal epithelium to GC and to encourage researches involved in MAPK signal transduction, that seems to definitely sustain GC development.

LncRNA MALAT1 exhibits positive effects on nucleus pulposus cell biology in vivo and in vitro by sponging miR-503

Background

Intervertebral disc degeneration (IDD) is characterized by the loss of nucleus pulposus cells (NPCs) and phenotypic abnormalities. Accumulating evidence suggests that long noncoding RNAs (lncRNAs) are involved in the pathogenesis of IDD. In this study, we aimed to investigate the functional effects of lncRNA MALAT1 on NPCs in IDD and the possible mechanism governing these effects.

Results

We validated the decreased expression of MALAT1 in the IDD tissues, which was associated with decreased Collagen II and Aggrecan expression. In vitro, overexpressed MALAT1 could attenuate the effect of IL-1β on NPC proliferation, apoptosis, and Aggrecan degradation. In vivo, MALAT1 overexpression attenuated the severity of disc degeneration in IDD model rats. Our molecular study further demonstrated that MALAT1 could sponge miR-503, modulate the expression of miR-503, and activate downstream MAPK signaling pathways. The effects of MALAT1 on NPCs were partially reversed/aggregated by miR-503 mimics/inhibitor treatment.

Conclusion

Our data suggested that the MALAT1-miR-503-MAPK pathway plays a critical role in NPCs, which may be a potential strategy for alleviating IDD.

Long non-coding RNA signature in gastric cancer

Gastric cancer as a common human malignancy has been associated with aberrant expressions of several coding and non-coding genes. Long non-coding RNAs (lncRNAs) as regulators of gene expressions at different genomic, transcriptomic and post-transcriptomic levels are among putative biomarkers and therapeutic targets in gastric cancer. In the present study, we have searched available literature and listed lncRNAs that are involved in the pathogenesis of gastric cancer. In addition, we discuss associations between expressions of these lncRNAs and tumoral features or risk factors for gastric cancer. Based on the established role of lncRNAs in regulation of genomic stability, cell cycle, apoptosis, angiogenesis and other aspects of cell physiology, the potential of these transcripts as therapeutic targets in gastric cancer should be evaluated in future studies.

Colon Cancer-Associated Transcripts 1 and 2: Roles and functions in human cancers

The long noncoding RNAs (lncRNAs) Colon Cancer-Associated Transcripts 1 and 2 (CCAT1 and CCAT2) are located in a recurrently amplified region in cancers. Their proximity with the Myc oncogene and their interactions with its promoter provided further evidence for their contribution in the tumorigenesis processes. Several cell line and clinical studies have shown upregulation of these lncRNAs in diverse malignancies. Moreover, some single nucleotide variants within these genes have been associated with cancer risk or therapeutic response in different populations. Besides, these two lncRNAs act as sponges for some tumor suppressor microRNAs (miRNAs), thus promoting cancer evolution. In the current study, we review recent literature about their expression level, interaction with cancer-related pathways, their role in determination of cell fate and their contribution in malignant phenotype characteristics. Taken together, the current literature shows that these lncRNAs are putative targets for design of novel treatment strategies. Moreover, their expression levels in biopsied samples, exosomes, and sera of patients might be applied as diagnostic biomarkers or markers for patient follow-up.

The Mechanism of MAPK Signal Transduction Pathway Involved with Electroacupuncture Treatment for Different Diseases

The mitogen-activated protein kinase (MAPK) signal transduction pathway plays an important role in the regulation of various diseases, such as cardiovascular and cerebrovascular diseases, and takes part in anti-inflammatory effects, analgesic effects, protection against injury, and maintenance of gastrointestinal functions. Electroacupuncture therapy is an external therapy used in traditional Chinese medicine. By adding external electrical stimulation to traditional acupuncture, the stimulus gets doubled and the therapeutic efficacy gets enhanced accordingly. It combines the benefits of both acupuncture and electrical stimulation. In recent years, some studies have explored the molecular mechanisms of MAPK signal pathways involved with electroacupuncture treatment. Based on these recent studies, this article summarizes the mechanisms of MAPK signal transduction pathways involved with electroacupuncture treatment. This adds great value to the studies of molecular mechanisms of electroacupuncture treatment and also provides an effective reference for its clinical use.

Upregulation of lncRNA GATA6-AS suppresses the migration and invasion of cervical squamous cell carcinoma by downregulating MTK-1

The diagnosis and treatment of cervical squamous cell carcinoma is challenged by difficulties in the determination of tumor invasion. GATA binding protein 6 antisense (GATA6-AS) is a recently identified long non-coding RNA that exhibits critical functions in the growth of endothelial cells; however, to the best of our knowledge, its involvement in other physiological and pathological processes is unknown. By reverse transcription-quantitative polymerase chain reaction, the present study examined the expression of GATA6-AS in tumor tissues and adjacent healthy tissues, and the serum from patients with cervical squamous cell carcinoma and healthy controls. The diagnostic and prognostic potentials of GATA6-AS for cervical squamous cell carcinoma were analyzed by receiver operating characteristic curve analysis and survival curve analysis, respectively. Associations between the serum levels of GATA6-AS and clinical characteristics of patients with cervical squamous cell carcinoma were analyzed by a χ² test. A GATA6-AS overexpression vector was transfected into cervical squamous cell carcinoma cells, and the effects on cell migration and invasion were investigated by Transwell migration and invasion assays, respectively. The expression of mitogen-activated protein kinase kinase 4 (MTK-1) following transfection with the GATA6-AS overexpression vector was detected by western blot analysis. It was identified that the expression levels of GATA6-AS were lower in tumor tissues compared with healthy tissues. In addition, serum levels of GATA6-AS were higher in patients compared with healthy controls. The serum levels of GATA6-AS were associated with tumor metastasis, and may serve as a potential diagnostic and prognostic marker for cervical squamous cell carcinoma. Furthermore, GATA6-AS overexpression inhibited cancer cell migration and invasion. The expression levels of MTK-1 were also reduced following GATA6-AS overexpression. Therefore, the present study proposed that downregulated GATA6-AS expression was associated with tumor metastasis in cervical squamous cell carcinoma, and that GATA6-AS expression may inhibit cancer cell migration and invasion by downregulating MTK-1.

Long non-coding RNAs: Diverse roles in various disorders

BACKGROUND

Long non-coding RNAs (lncRNAs) are a group of transcripts larger than 200 nucleotides that are not translated to proteins. These transcripts regulate expression of numerous genes at different levels by acting as decoys, scaffolds, and enhancers. Thus they regulate cell development, differentiation and fate.

OBJECTIVE

To find the role of lncRNAs in various diseases.

METHODS

We searched PubMed and google scholar and summarized the data regarding the role of lncRNAs in cancer and neurologic disorders.

RESULTS

Several recent studies have shown that their expressions are up-/down-regulated in malignant tissues. Consequently, they have suggested that lncRNAs can differentiate cancer samples from normal samples. Their application as biomarker is not limited to cancers. In several neurologic or psychiatric disorders researchers have found aberrant expression of lncRNAs.

CONCLUSIONS

Taken together, lncRNAs constitute a novel vast area of research to find answer to fundamental biologic questions.

The lncRNA RMEL3 protects immortalized cells from serum withdrawal-induced growth arrest and promotes melanoma cell proliferation and tumor growth

RMEL3 is a recently identified lncRNA associated with BRAFV600E mutation and melanoma cell survival. Here, we demonstrate strong and moderate RMEL3 upregulation in BRAF and NRAS mutant melanoma cells, respectively, compared to melanocytes. High expression is also more frequent in cutaneous than in acral/mucosal melanomas, and analysis of an ICGC melanoma dataset showed that mutations in RMEL3 locus are preponderantly C > T substitutions at dipyrimidine sites including CC > TT, typical of UV signature. RMEL3 mutation does not correlate with RMEL3 levels, but does with poor patient survival, in TCGA melanoma dataset. Accordingly, RMEL3 lncRNA levels were significantly reduced in BRAFV600E melanoma cells upon treatment with BRAF or MEK inhibitors, supporting the notion that BRAF-MEK-ERK pathway plays a role to activate RMEL3 gene transcription. RMEL3 overexpression, in immortalized fibroblasts and melanoma cells, increased proliferation and survival under serum starvation, clonogenic ability, and xenografted melanoma tumor growth. Although future studies will be needed to elucidate the mechanistic activities of RMEL3, our data demonstrate that its overexpression bypasses the need of mitogen activation to sustain proliferation/survival of non-transformed cells and suggest an oncogenic role for RMEL3.