Elevated serum lncRNA TUG1 levels are a potential diagnostic biomarker of multiple myeloma

Long non-coding RNA TUG1 is downregulated in Friedreich's ataxia

Friedreich's ataxia is a neurodegenerative disorder caused by reduced frataxin levels. It leads to motor and sensory impairments and has a median life expectancy of around 35 years. As the most common inherited form of ataxia, Friedreich's ataxia lacks reliable, non-invasive biomarkers, prolonging and inflating the cost of clinical trials. This study proposes TUG1, a long non-coding RNA, as a promising blood-based biomarker for Friedreich's ataxia, which is known to regulate various cellular processes. In a previous study using a frataxin knockdown mouse model, we observed several hallmark Friedreich's ataxia symptoms. Building on this, we hypothesized that a dual-source approach-comparing the data from peripheral blood samples from Friedreich's ataxia patients with tissue samples from affected areas in Friedreich's ataxia knockdown mice, tissues usually unattainable from patients-would effectively identify robust biomarkers. A comprehensive reanalysis was conducted on gene expression data from 183 age- and sex-matched peripheral blood samples of Friedreich's ataxia patients, carriers and controls and 192 tissue data sets from Friedreich's ataxia knockdown mice. Blood and tissue samples underwent RNA isolation and quantitative reverse transcription polymerase chain reaction, and frataxin knockdown was confirmed through enzyme-linked immunosorbent assays. Tug1 RNA interaction was explored via RNA pull-down assays. Validation was performed in serum samples on an independent set of 45 controls and 45 Friedreich's ataxia patients and in blood samples from 66 heterozygous carriers and 72 Friedreich's ataxia patients. Tug1 and Slc40a1 emerged as potential blood-based biomarkers, confirmed in the Friedreich's ataxia knockdown mouse model (one-way ANOVA, P ≤ 0.05). Tug1 was consistently downregulated after Fxn knockdown and correlated strongly with Fxn levels (R 2 = 0.71 during depletion, R 2 = 0.74 during rescue). Slc40a1 showed a similar but tissue-specific pattern. Further validation of Tug1's downstream targets strengthened its biomarker candidacy. In additional human samples, TUG1 levels were significantly downregulated in both whole blood and serum of Friedreich's ataxia patients compared with controls (Wilcoxon signed-rank test, P < 0.05). Regression analyses revealed a negative correlation between TUG1 fold-change and disease onset (P < 0.0037) and positive correlations with disease duration and functional disability stage score (P < 0.04). This suggests that elevated TUG1 levels correlate with earlier onset and more severe cases. This study identifies TUG1 as a potential blood-based biomarker for Friedreich's ataxia, showing consistent expression variance in human and mouse tissues related to disease severity and key Friedreich's ataxia pathways. It correlates with frataxin levels, indicating its promise as an early, non-invasive marker. TUG1 holds potential for Friedreich's ataxia monitoring and therapeutic development, meriting additional research.

Biological roles of SLC16A1-AS1 lncRNA and its clinical impacts in tumors

Recent studies have increasingly highlighted the aberrant expression of SLC16A1-AS1 in a variety of tumor types, where it functions as either an oncogene or a tumor suppressor in the pathogenesis of different cancers. The expression levels of SLC16A1-AS1 have been found to significantly correlate with clinical features and the prognosis of cancer patients. Furthermore, SLC16A1-AS1 modulates a range of cellular functions, including proliferation, migration, and invasion, through its interactions with diverse molecules and signaling pathways. This review examines the latest evidence regarding the role of SLC16A1-AS1 in the progression of various tumors and explores its potential clinical applications as a novel prognostic and diagnostic biomarker. Our comprehensive review aims to deepen the understanding of SLC16A1-AS1's multifaceted role in oncology, underscoring its potential as a significant biomarker and therapeutic target.

The diagnostic value of serum lncRNA CATG00000112921.1 as a marker of multiple myeloma

BACKGROUND

Multiple myeloma (MM) is a malignant plasma cell disease. At present, numerous studies have shown that lncRNA plays a very important role in the occurrence, development and even drug resistance of multiple myeloma. It may become a potential diagnostic and prognostic marker of multiple myeloma and provide new ideas for targeted therapy. Based on the above research background, this study used gene chip technology to screen out the differentially expressed lncRNA in the serum of MM patients and healthy people, and verified more clinical serum samples to screen out the lncRNA with the largest difference as a biomarker for further research.

METHOD

In this research, the data of hospitalized patients diagnosed with MM and healthy people in the Affiliated Hospital of Guangdong Medical University were retrospectively collected. The lncRNA expression profile of serum samples from patients with multiple myeloma and healthy controls was analyzed by lncRNA chip technology. The serum samples were verified by real-time fluorescence quantitative PCR, and the candidate diagnostic markers were screened out. The ROC working curve was drawn to evaluate the diagnostic efficacy of the candidate markers and to determine their stability at different temperatures and time.

RESULT

A total of 44 MM patients and 37 healthy people were involved in this research. Among them, 4 patients with MM and 4 patients with HD were sent for microarray analysis. According to Fold Change ≥ 2 and P < 0.05, a total of 17 differentially expressed lncRNA molecules were screened, of which 9 were up-regulated RNA molecules and 8 were down-regulated RNA molecules. Through real-time fluorescence quantitative PCR verification, it was found that lncRNA CATG00000112921.1 was highly expressed in the healthy control group and diminished in patients with multiple myeloma, P < 0.001. The ROC curve demonstrated that the area under the curve (AUC) was 0.749, the sensitivity was 0.636, the specificity was 0.789, and the 95 % CI was 0.636-0.862 (P < 0.001). In addition, in order to verify the effects of temperature, time and repeated freezing and thawing on lncRNA, it was placed at 25°C, 4°C, -20°C, -80°C for 0 h, 24 h, 48 h, 72 h, and placed at-80°C repeated freezing and thawing 0 times, 2 times, 4 times, 8 times, and the expression level was not significantly changed.

CONCLUSION

Serum lncRNA CATG00000112921.1 may be a potential candidate diagnostic marker for multiple myeloma. The ROC curve shows that it has good diagnostic value, and its high stability at different temperatures and different times is a required condition for becoming a diagnostic marker. As far as we know, this is the first study in the world to find differential expression of lncRNA CATG00000112921.1 in peripheral serum of healthy people and newly diagnosed multiple myeloma patients. This study also highlights the application of gene chip technology in screening differentially expressed genes.

lncRNA TUG1 as potential novel biomarker for prognosis of cardiovascular diseases

Globally, cardiovascular diseases (CVDs) are among the leading causes of death. In light of the high prevalence and mortality of CVDs, it is imperative to understand the molecules involved in CVD pathogenesis and the signaling pathways that they initiate. This may facilitate the development of more precise and expedient diagnostic techniques, the identification of more effective prognostic molecules and the identification of potential therapeutic targets. Numerous studies have examined the role of lncRNAs, such as TUG1, in CVD pathogenesis in recent years. According to this review article, TUG1 can be considered a biomarker for predicting the prognosis of CVD.

Non-coding RNAs and exosomal ncRNAs in multiple myeloma: An emphasis on molecular pathways

One of the most common hematological malignancies is multiple myeloma (MM) that its mortality and morbidity have increased. The incidence rate of MM is suggested to be higher in Europe and various kinds of therapeutic strategies including stem cell transplantation. However, MM treatment is still challenging and gene therapy has been shown to be promising. The non-coding RNAs (ncRNAs) including miRNAs, lncRNAs and circRNAs are considered as key players in initiation, development and progression of MM. In the present review, the role of ncRNAs in MM progression and drug resistance is highlighted to provide new insights for future experiments for their targeting and treatment of MM. The miRNAs affect proliferation and invasion of MM cells, and targeting tumor-promoting miRNAs can induce apoptosis and cell cycle arrest, and reduces proliferation of MM cells. Furthermore, miRNA regulation is of importance for modulating metastasis and chemotherapy response of tumor cells. The lncRNAs exert the same function and determine proliferation, migration and therapy response of MM cells. Notably, lncRNAs mainly target miRNAs in regulating MM progression. The circRNAs also target different molecular pathways in regulating MM malignancy that miRNAs are the most well-known ones. Furthermore, clinical application of ncRNAs in MM is discussed.

Oncogenic Dysregulation of Circulating Noncoding RNAs: Novel Challenges and Opportunities in Sarcoma Diagnosis and Treatment

Simple Summary

Body fluids contain different classes of RNA molecules such as protein-coding messenger RNAs (mRNA) and noncoding RNAs, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs). These circulating RNAs can travel naked or packed into extracellular vesicles and display valuable potential as non-invasive biomarkers of sarcoma malignancy. In this review, we summarize current knowledge on the possible functions of these circulating RNAs and discuss their possible exploitation as novel markers to improve sarcoma diagnosis and prognosis. Despite the recent advance in technological tools have improved protocols for the extraction and detection of circulating RNA, many aspects related to the biology of these molecules remain to be elucidated. In particular, the lack of standardization in the assessment of these markers makes difficult their adoption into clinical practice.

Abstract

Sarcomas comprise a heterogeneous group of rare mesenchymal malignancies. Sarcomas can be grouped into two categories characterized by different prognosis and treatment approaches: soft tissue sarcoma and primary bone sarcoma. In the last years, research on novel diagnostic, prognostic or predictive biomarkers in sarcoma management has been focused on circulating tumor-derived molecules as valuable tools. Liquid biopsies that measure various tumor components, including circulating cell-free DNA and RNA, circulating tumor cells, tumor extracellular vesicles and exosomes, are gaining attention as methods for molecular screening and early diagnosis. Compared with traditional tissue biopsies, liquid biopsies are minimally invasive and blood samples can be collected serially over time to monitor cancer progression. This review will focus on circulating noncoding RNA molecules from liquid biopsies that are dysregulated in sarcoma malignancies and discuss advantages and current limitations of their employment as biomarkers in the management of sarcomas. It will also explore their utility in the evaluation of the clinical response to treatments and of disease relapse. Moreover, it will explore state-of-the-art techniques that allow for the early detection of these circulating biomarkers. Despite the huge potential, current reports highlight poor sensitivity, specificity, and survival benefit of these methods, that are therefore still insufficient for routine screening purposes.

Knockdown of lncRNA AL928768.3 inhibits multiple myeloma cell proliferation by inducing cell cycle arrest in G0/G1 phase

Background

Multiple myeloma (MM) is a B-lymphocyte-derived malignancy. It ranks as the second most common hematological malignancy, with relatively high morbidity and mortality. However, the molecular mechanisms of MM occurrence and development remain elusive. This study found that long non-coding RNA AL928768.3 (lncRNA AL) was abnormally expressed in MM samples. However, the effect and molecular mechanism of lncRNA AL on the occurrence and development of MM remains unclear.

Methods

Bone marrow fluids of MM patients (n=54) and volunteers (n=13) were collected and CD138⁺ cells were isolated. The expression level of lncRNA AL in MM cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR), and the correlation between the expression level of lncRNA AL and the clinicopathological features of patients was analyzed. Lentiviral vectors targeting lncRNA AL knockdown were constructed and transfected into cells. After transfection, the effects of lncRNA AL knockdown on MM cell proliferation and the cell cycle were detected by the CCK-8 assay, clone formation assay, and flow cytometry. The effect of lncRNA AL knockdown on MM cell cycle-related proteins was detected by Western blot. In addition, tumorigenicity experiments were performed in nude mice to detect the effect of lncRNA AL knockdown on MM cell proliferation in vivo.

Results

LncRNA AL was highly expressed in MM patient samples and cell lines, and was significantly correlated with the disease stage of patients. Knockdown of lncRNA AL significantly inhibited the proliferation and colony formation of MM cells and induced cell cycle arrest in G0/G1 phase. Western blot analysis showed that knockdown of lncRNA AL significantly inhibited the expression of CDK2 and cyclin D1 and promoted the expression of cyclin suppressor p21. Knockdown of lncRNA AL significantly inhibited the proliferation of MM cells in nude mice.

Conclusions

LncRNA AL was highly expressed in MM patients. Knockdown of this gene significantly inhibited the proliferative ability of MM cells and induced cell cycle arrest in G0/G1 phase. Therefore, lncRNA AL may be a novel biological target molecule for the early diagnosis, treatment, and prognostic evaluation of MM patients.

Prognostic significance of long non-coding RNA five prime to XIST in various cancers

BACKGROUND

To observe the clinicopathological and prognostic value of long non-coding RNA five prime to X inactive specific transcript (lncFTX) in multiple tumors.

METHODS

Eligible studies for lncFTX were identified by searching PubMed, Embase, Web of Science and Cochrane Library databases from inception to December 01, 2020. Stata 12.0 software was used to calculate the odds ratio (OR)/hazard ratio (HR) and 95% confidence interval (95% CI). We used The Cancer Genome Atlas (TCGA) dataset to further investigate the differential expression and prognostic value of lncFTX.

RESULTS

We included 11 studies involving a total of 1633 patients. The results showed that the expression of lncFTX was positively associated with advanced TNM stage (III-IV versus I-II) (OR = 2.30, 95% CI: 1.74-3.03, P < 0.05), lymph nodes metastasis (OR = 3.01, 95% CI: 2.00-4.52, P < 0.05), distant metastasis (OR = 3.68, 95% CI: 2.13-6.34, P < 0.05), and cancer mortality (HR = 1.83, 95% CI: 1.20-2.81, P < 0.05). However, the expression of lncFTX was not associated with tumor differentiation (poor differentiation versus well or moderate differentiation) and vessel invasion of cancer. Subgroup analysis showed that the higher lncFTX expression was associated with shorter overall survival in cancer patients, regardless of the sample size and cancer type. No publication bias was found, and the sensitivity analysis results suggested that the main findings were robust. Elevated expression and prognostic significance of FTX were confirmed using TCGA dataset.

CONCLUSIONS

This study found that the expression of lncFTX was positively associated with advanced tumor node metastasis (TNM) stage, lymph nodes, distant metastasis and, cancer mortality, suggesting that lncFTX might be a potential prognostic biomarker for tumors.

Long Noncoding RNAs Involved in Cardiomyocyte Apoptosis Triggered by Different Stressors

Cardiomyocytes are essential to maintain the normal cardiac function. Ischemia, hypoxia, and drug stimulation can induce pathological apoptosis of cardiomyocytes which eventually leads to heart failure, arrhythmia, and other cardiovascular diseases. Understanding the molecular mechanisms that regulate cardiomyocyte apoptosis is of great significance for the prevention and treatment of cardiovascular diseases. In recent years, more and more evidences reveal that long noncoding RNAs (lncRNAs) play important regulatory roles in myocardial cell apoptosis. They can modulate the expression of apoptosis-related genes at post-transcriptional level by altering the translation efficacy of target mRNAs or functioning as a precursor for miRNAs or competing for miRNA-mediated inhibition. Moreover, reversing the abnormal expression of lncRNAs can attenuate and even reverse the pathological apoptosis of cardiomyocytes. Therefore, apoptosis-related lncRNAs may become a potential new field for studying cardiomyocyte apoptosis and provide new ideas for the treatment of cardiovascular diseases.

Long noncoding RNA TUG1 upregulates VEGFA to enhance malignant behaviors in stomach adenocarcinoma by sponging miR-29c-3p

BACKGROUND

Long noncoding RNA (lncRNA) TUG1 has been reported to display a pivotal role in the tumorigenesis and malignant progression of various types of cancers, including stomach adenocarcinoma (STAD). However, the contribution of aberrant expression of TUG1 and the mechanism by which it serves as a competing endogenous RNA (ceRNA) in STAD remains largely obscure.

METHODS

The human STAD cell lines (MGC-803 and AGS), human normal gastric epithelial cell line (GES-1), human umbilical vein endothelial cells (HUVECs), and human embryonic kidney cells (HEK293T) were purchased and cultured to investigate the roles of TUG1 in STAD. Twenty BALB/c nude mice were purchased to establish a xenograft model to explore the roles of TUG1 in vivo.

RESULTS

Bioinformatics analysis revealed that TUG1 was upregulated in STAD, of which expression was negatively and positively correlated with miR-29c-3p and VEGFA, respectively. Functional analyses indicated that TUG1 functioned as an oncogene to promote malignant behaviors (proliferation, migration, and angiogenesis) of STAD cells; whereas miR-29c-3p exerted the opposite role. Mechanistically, the interaction between miR-29c-3p with TUG1 and VEGFA was demonstrated. It was observed that miR-29c-3p could reverse the TUG1-induced promotion effect on cell proliferation, migration, and angiogenesis in STAD. Furthermore, TUG1 overexpression promoted STAD cell proliferation, metastasis, and angiogenesis, whereas VEGFA silence restored these effects, both in vitro and in vivo.

CONCLUSION

This finding confirmed that lncRNA TUG1 acts as a ceRNA for miR-29c-3p to promote tumor progression and angiogenesis by upregulating VEGFA, indicating TUG1 as a therapeutic target in STAD management.

Long non-coding RNAs (lncRNAs) as prognostic and diagnostic biomarkers in multiple myeloma: A systematic review and meta-analysis

BACKGROUND

Recently, emerging studies have demonstrated the utility of particular long non-coding RNAs (lncRNAs) as useful biomarkers for the diagnosis and prognosis of multiple myeloma (MM). We systematically reviewed the literature and conducted a meta-analysis to quantify the predictive effectiveness of lncRNAs in the prognosis and diagnosis of MM.

METHODS

A systematic search was performed in PubMed, Embase, and Web of Science until March 24, 2021. A meta-analysis was conducted to explore the correlation between the expression of lncRNAs and prognostic endpoints, including overall survival (OS), progression-free survival (PFS), and disease-free survival (DFS) or event-free survival (EFS). Moreover, the diagnostic performance of lncRNAs in MM was investigated by calculating accuracy metrics.

RESULTS

Overall, 43 studies were included in this systematic review, amongst which 36 studies assessed prognostic endpoints (including 5499 participants and 69 lncRNAs), and 11 studies evaluated diagnostic outcomes (with 1723 participants and 11 lncRNAs). The overexpression of CRNDE (hazard ratio (HR)= 1.94, 95% confidence interval (CI) 1.61, 2.34), NEAT1 (HR=1.97, 95%CI 1.36, 2.85), PVT1 (HR=1.92, 95%CI 1.25, 2.97), and TCF7 (HR=1.98, 95%CI 1.42, 2.76) was significantly associated with reduced OS. Furthermore, upregulation of PVT1 was significantly correlated with poor PFS (HR=1.86, 95%CI 1.29, 2.68). The pooled diagnostic performance of lncRNAs was as follows: sensitivity 0.78 (95%CI 0.73, 0.82), specificity 0.88 (95%CI 0.83, 0.92), and area under the curve 0.89 (95%CI 0.86, 0.92).

CONCLUSIONS

Our results revealed the potential significance of lncRNAs in MM as diagnostic and prognostic markers, which may be the future targets for individualized therapy.

Differential expression of long non-coding RNAs as diagnostic markers for lung cancer and other malignant tumors

Due to advances in chip and sequencing technology, several types and numbers of long non-coding RNAs (lncRNAs) have been identified. LncRNAs are defined as non-protein-coding RNA molecules longer than 200 nucleotides, and are now thought as a new frontier in the study of human malignant diseases including NSCLC. Diagnosis of numerous malignant tumors has been closely linked to the differential expression of certain lncRNAs. LncRNAs are involved in gene expression regulation at multiple levels of epigenetics, transcriptional regulation, and post-transcriptional regulation. Mutations, deletions, or abnormal expression levels lead to physiological abnormalities, disease occurrence and are closely associated with human tumor diseases. LncRNAs play a crucial role in cancerous processes as either oncogenes or tumor suppressor genes. The expression of lncRNAs can regulate tumor cell in the proliferation, migration, apoptosis, cycle, invasion, and metastasis. As such, lncRNAs are potential diagnostic and treatment targets for cancer. And that, tumor biomarkers need to be detectable in easily accessible body samples, should be characterized by high specificity and sufficient sensitivity. Herein, it is significant clinical importance to screen and supplement new biomarkers for early diagnosis of lung cancer. This study aimed at systematically describing lncRNAs from five aspects based on recent studies: concepts, classification, structure, molecular mechanism, signal pathway, as well as review lncRNA implications in malignant tumor.

The Prognostic Value of Long Non-Coding RNA SNHG7 in Human Cancer: A Meta-Analysis

BACKGROUND

The long non-coding RNA SNHG7 is upregulated in many types of cancer and plays a role as an oncogene. However, its overall predictive ability in human cancer prognosis has not been assessed using existing databases. Therefore, further study of its prognostic value and clinical significance in human malignancies is warranted.

METHODS

We systematically collected relevant literature from multiple electronic document databases about the relationship between SNHG7 expression level and prognosis in patients with solid cancers. We further screened them for eligibility. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were used to assess the prognostic value. Odds ratios (ORs) and their 95% CIs were collected to evaluate the relationship between the expression of SNHG7 and clinicopathological features, including lymph node metastasis (LNM), tumour size, tumour node metastasis (TNM) stage and histological grade.

RESULTS

Fourteen original studies involving 971 patients were enrolled strictly following the inclusion and exclusion criteria. The meta-analysis showed that SNHG7 expression was significantly correlated with poor overall survival (HR = 1.93, 95% CI: 1.64-2.26, p<0.001) in human cancer patients. In addition, the pooled OR indicated that overexpression of SNHG7 was associated with earlier LNM (OR = 1.83, 95% CI: 1.44-2.32; P <0.001), and advanced TNM stage (OR = 1.82, 95% CI: 1.44-2.30; P <0.001).Meanwhile, there was no significant heterogeneity between the selected studies, proving the reliability of the meta-analysis results.

CONCLUSIONS

High SNHG7 expression may predict poor oncological outcomes in patients with multiple human cancers, which could be a novel prognostic biomarker of unfulfilled clinicopathological features. However, further high-quality studies are needed to verify and strengthen the clinical value of SNHG7 in different types of cancer.

Non-coding Natural Antisense Transcripts: Analysis and Application

Non-coding natural antisense transcripts (ncNATs) are regulatory RNA sequences that are transcribed in the opposite direction to protein-coding or non-coding transcripts. These transcripts are implicated in a broad variety of biological and pathological processes, including tumorigenesis and oncogenic progression. With this complex field still in its infancy, annotations, expression profiling and functional characterisations of ncNATs are far less comprehensive than those for protein-coding genes, pointing out substantial gaps in the analysis and characterisation of these regulatory transcripts. In this review, we discuss ncNATs from an analysis perspective, in particular regarding the use of high-throughput sequencing strategies, such as RNA-sequencing, and summarize the unique challenges of investigating the antisense transcriptome. Finally, we elaborate on their potential as biomarkers and future targets for treatment, focusing on cancer.

Lateral flow assay-based detection of long non-coding RNAs: A point-of-care platform for cancer diagnosis

Lateral flow assay (LFA) is a flexible, simple, low-costpoint-of-care platform for rapid detection of disease-specific biomarkers. Importantly, the ability of the assay to capture the circulating bio-molecules has gained significant attention, as it offers a potential minimal invasive system for early disease diagnosis and prognosis. In the present article, we review an innovative concept of LFA-based detection of circulating long non-coding RNAs (lncRNAs), one of the key regulators of fundamental biological processes. In addition, their disease-specific expression pattern and presence in biological fluids at differential levels make them excellent biomarker candidates for cancer detection. Our article also provides an update on the requirements for developing and improving such systems and discusses the key aspects of material selection, operational concepts, principles and conceptual design. We assume that the reviewed points will be helpful to improve the diagnostic applicability of LFA based lncRNA detection in cancer diagnosis.

Correlation analysis of long non-coding RNA TUG1 with disease risk, clinical characteristics, treatment response, and survival profiles of adult Ph- Acute lymphoblastic leukemia

Background

Long non‐coding RNA taurine‐upregulated gene 1 (lncRNA TUG1) is reported to be involved in the progression and development of several malignancies; however, its role in Philadelphia chromosome‐negative acute lymphoblastic leukemia (Ph⁻ALL) is unknown. The present study aimed to explore the correlation of lncRNA TUG1 with disease risk, disease condition, and prognosis of adult Ph⁻ALL.

Methods

Total 101 adult Ph⁻ ALL patients and 40 bone marrow (BM) donors were included, followed by detection of BM monocyte cell lncRNA TUG1 expression by reverse transcription‐quantitative polymerase chain reaction. According to the quantiles of lncRNA TUG1 expression in Ph⁻ ALL patients, these patients were divided into four tiers: tier 1 (ranked in 0%~25%), tier 2 (ranked in 25%~50%), tier 3 (ranked in 50%~75%), and tier 4 (ranked in 75%~100%).

Results

LncRNA TUG1 was upregulated in Ph⁻ ALL patients compared with healthy donors. Further analysis indicated that in Ph⁻ ALL patients, higher lncRNA TUG1 tier was correlated with the presence of central nervous system leukemia, increased white blood cell level, and bone marrow blasts. Furthermore, higher lncRNA TUG1 tier was negatively associated with complete remission (CR) within 4 weeks, total CR, and allogeneic hematopoietic stem cell transplant achievement. In addition, higher lncRNA TUG1 tier was associated with decreased disease‐free survival and overall survival, which was further verified to be an independent factor by Cox's regression analysis.

Conclusion

lncRNA TUG1 presents potential to be a novel biomarker for disease risk assessment and survival surveillance in Ph⁻ ALL management.

Role of long noncoding RNA taurine-upregulated gene 1 in cancers

Long non-coding RNAs (lncRNAs) are a group of non-protein coding RNAs with a length of more than 200 bp. The lncRNA taurine up-regulated gene 1 (TUG1) is abnormally expressed in many human malignant cancers, where it acts as a competitive endogenous RNA (ceRNA), regulating gene expression by specifically sponging its corresponding microRNAs. In the present review, we summarised the current understanding of the role of lncRNA TUG1 in cancer cell proliferation, metastasis, angiogenesis, chemotherapeutic drug resistance, radiosensitivity, cell regulation, and cell glycolysis, as well as highlighting its potential application as a clinical biomarker or therapeutic target for malignant cancer. This review provides the basis for new research directions for lncRNA TUG1 in cancer prevention, diagnosis, and treatment.

Long non-coding RNAs in the doxorubicin resistance of cancer cells

Chemotherapy is the main treatment used for cancer patients failing surgery. Doxorubicin (DOX) is a well-known chemotherapeutic agent capable of suppressing proliferation in cancer cells and triggering apoptosis via inhibiting topoisomerase II activity and producing DNA breaks. This activity of DOX restrains mitosis and cell cycle progression. However, frequent application of DOX results in the emergence of resistance in the cancer cells. It seems that genetic and epigenetic factors can provide DOX resistance of cancer cells. Long non-coding RNAs (lncRNAs) are a subcategory of non-coding RNAs with role in the regulation of several cellular processes such as proliferation, migration, differentiation and apoptosis. LncRNA dysregulation has been associated with chemoresistance, and this profile occurs upon DOX treatment of cancer. In the present review, we focus on the role of lncRNAs in mediating DOX resistance and discuss the molecular pathways and mechanisms. LncRNAs can drive DOX resistance via activating pathways such as NF-κB, PI3K/Akt, Wnt, and FOXC2. Some lncRNAs can activate protective autophagy in response to the stress caused by DOX, which mediates resistance. In contrast, there are other lncRNAs involved in the sensitivity of cancer cells to DOX, such as GAS5, PTCSC3 and FENDRR. Some anti-tumor agents such as polydatin can regulate the expression of lncRNAs, enhancing DOX sensitivity. Overall, lncRNAs are potential players in DOX resistance, and their identification and targeting are of importance in chemosensitivity. Furthermore, these findings can be translated into clinical for treatment of cancer patients.

Silencing of long noncoding RNA TUG1 inhibits viability and promotes apoptosis of acute myeloid leukemia cells by targeting microRNA-221-3p/KIT axis

OBJECTIVE: Acute myeloid leukemia (AML) is a hematological malignancy. This study was attempted to uncover the effects of long noncoding RNA taurine-upregulated gene1 (TUG1) on the viability and apoptosis of AML cells. METHODS: QRT-PCR was implemented to examine the expression of TUG1, miR-221-3p and KIT in AML. The correlation between TUG1 and clinicopathological features of AML patients was evaluated. The effect of TUG1 on AML cells were studied by RNA interference approach. AML cells were transfected with miR-221-3p mimic and miR-221-3p inhibitor, respectively. Then the viability and apoptosis of AML cells were examined by MTT and flow cytometry assay, respectively. Additionally, dual-luciferase reporter assay was used to confirm the interactions among TUG1, miR-221-3p and KIT. Western blot was applied to analyze protein expression of KIT. RESULTS: The expression of TUG1 and KIT was up-regulated in AML, but miR-221-3p was down-regulated. TUG1 expression had obviously correlation with World Health Organization (WHO) grade in AML patients. The functional experiment stated that TUG1 silencing suppressed the viability and accelerated the apoptosis of AML cells. Moreover, the mechanical experiment demonstrated that TUG1 and KIT were both targeted by miR-221-3p with the complementary binding sites at 3’UTR. Up-regulation of miR-221-3p inhibited the protein expression of KIT. Furthermore, in the feedback experiment, miR-221-3p inhibition or KIT overexpression reversed the repression of tumor behavior induced by TUG1 silencing. CONCLUSIONS: TUG1 silencing retarded viability and promoted apoptosis of AML cells via regulating miR-221-3p/KIT axis, providing a potential therapeutic target for AML.

The relationship between Long Noncoding RNA (lncRNA) Small Nucleolar RNA Host Gene 12 (SNHG12) expression in solid malignant tumors and prognosis of tumor patients: A systematic review and meta-analysis

BACKGROUND

Small nucleolar RNA host gene 12 (SNHG12) has been demonstrated to be a long noncoding RNA (lncRNA) that facilitates the progression of several solid malignant tumors. However, whether the expression level of SNHG12 in solid malignant tumors is associated with patients prognosis have not been investigated.

METHODS

We systematically searched PubMed, EMBASE and Cochrane Library from Jan 1, 1950 to Mar 24, 2020 for randomized controlled trials published in English on SNHG12 expression in solid malignant tumors. We used the Newcastle-Ottawa Scale to assess the quality of articles. The HRs and 95%CI that extracted from Kaplan-Meier curves were used to perform the forest plot using a fixed-effects model. The meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

Thirteen articles containing 821 patients were included in this systematic review and meta-analysis. The result showed that high lncRNA SNHG12 expression is significantly associated with poor overall survival (OS) (HR = 1.94, 95% CI: 1.56-2.41, P < .001) and the studies are lack of statistically significant heterogeneity (P= .878, I = 0.0%). Beggs plot and Eggers test were applied to testify no publication bias existence in these studies. Subgroup analyses were performed and the result showed that TNM stage, lymph node metastasis and tumor type can influence the patients outcome, while there was no significantly correlation between SNHG12 expression and gender.

CONCLUSIONS

The systematical review and meta-analysis synthetically analyzed 13 articles including 821 patients with ten types of solid malignant tumors, concluding that higher lncRNA SNHG12 expression is significantly associated with worse clinical prognosis.

Non-Coding RNAs in Multiple Myeloma Bone Disease Pathophysiology

Bone remodeling is uncoupled in the multiple myeloma (MM) bone marrow niche, resulting in enhanced osteoclastogenesis responsible of MM-related bone disease (MMBD). Several studies have disclosed the mechanisms underlying increased osteoclast formation and activity triggered by the various cellular components of the MM bone marrow microenvironment, leading to the identification of novel targets for therapeutic intervention. In this regard, recent attention has been given to non-coding RNA (ncRNA) molecules, that finely tune gene expression programs involved in bone homeostasis both in physiological and pathological settings. In this review, we will analyze major signaling pathways involved in MMBD pathophysiology, and report emerging evidence of their regulation by different classes of ncRNAs.

Long non-coding RNA OIP5-AS1 suppresses multiple myeloma progression by sponging miR-27a-3p to activate TSC1 expression

BACKGROUND

Multiple myeloma (MM) is a prevalent hematological malignancy. Long noncoding RNAs are correlated with the development of MM. In this project, the function of lncRNA opa interacting protein 5-antisense 1 (OIP5-AS1) in MM and the potential mechanistic pathway were explored.

METHODS

The expression of OIP5-AS1, microRNA (miR)-27a-3p and tuberous sclerosis 1 (TSC1) was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) assay. Cell proliferation was assessed by Cell Counting Kit-8 (CCK-8) assay, colony formation assay and Bromodeoxyuridine (BrdU) staining. And cell apoptosis was evaluated by flow cytometry assay. Cell metastasis was assessed utilizing transwell assay. Western blot analysis was employed to detect protein level. The target relation between miR-27a-3p and OIP5-AS1 or TSC1 was confirmed via dual-luciferase reporter assay and RNA immunoprecipitation assay. Tumor xenograft assay was conducted to measure the function of OIP5-AS1 in vivo.

RESULTS

The expression levels of OIP5-AS1 and TSC1 were decreased in MM, whereas miR-27a-3p was upregulated. High level of OIP5-AS1 could predict favourable prognosis of MM patients. Overexpression of OIP5-AS1 inhibited cell viability, colony formation ability, migration and invasion, induced cell cycle arrest in G1 phase and apoptosis of MM cells in vitro as well as repressed tumorigenesis in vivo. MiR-27a-3p was a target of OIP5-AS1, and reversed the impact of OIP5-AS1 on MM cells. MiR-27a-3p directly targeted TSC1. Silencing of miR-27a-3p repressed MM progression by elevating TSC1 expression. OIP5-AS1 upregulated TSC1 by sponging miR-27a-3p.

CONCLUSION

OIP5-AS1 repressed multiple myeloma progression by regulating miR-27a-3p/TSC1 axis.

HNF4A-AS1/hnRNPU/CTCF axis as a therapeutic target for aerobic glycolysis and neuroblastoma progression

BACKGROUND

Aerobic glycolysis is a hallmark of metabolic reprogramming that contributes to tumor progression. However, the mechanisms regulating expression of glycolytic genes in neuroblastoma (NB), the most common extracranial solid tumor in childhood, still remain elusive.

METHODS

Crucial transcriptional regulators and their downstream glycolytic genes were identified by integrative analysis of a publicly available expression profiling dataset. In vitro and in vivo assays were undertaken to explore the biological effects and underlying mechanisms of transcriptional regulators in NB cells. Survival analysis was performed by using Kaplan-Meier method and log-rank test.

RESULTS

Hepatocyte nuclear factor 4 alpha (HNF4A) and its derived long noncoding RNA (HNF4A-AS1) promoted aerobic glycolysis and NB progression. Gain- and loss-of-function studies indicated that HNF4A and HNF4A-AS1 facilitated the glycolysis process, glucose uptake, lactate production, and ATP levels of NB cells. Mechanistically, transcription factor HNF4A increased the expression of hexokinase 2 (HK2) and solute carrier family 2 member 1 (SLC2A1), while HNF4A-AS1 bound to heterogeneous nuclear ribonucleoprotein U (hnRNPU) to facilitate its interaction with CCCTC-binding factor (CTCF), resulting in transactivation of CTCF and transcriptional alteration of HNF4A and other genes associated with tumor progression. Administration of a small peptide blocking HNF4A-AS1-hnRNPU interaction or lentivirus-mediated short hairpin RNA targeting HNF4A-AS1 significantly suppressed aerobic glycolysis, tumorigenesis, and aggressiveness of NB cells. In clinical NB cases, high expression of HNF4A-AS1, hnRNPU, CTCF, or HNF4A was associated with poor survival of patients.

CONCLUSIONS

These findings suggest that therapeutic targeting of HNF4A-AS1/hnRNPU/CTCF axis inhibits aerobic glycolysis and NB progression.