Long non-coding RNA lnc-PCTST predicts prognosis through inhibiting progression of pancreatic cancer by downregulation of TACC-3

Family with sequence similarity 111 member B contributes to tumor growth and metastasis by mediating cell proliferation, invasion, and EMT via transforming acidic coiled-coil protein 3/PI3K/AKT signaling pathway in hepatocellular carcinoma

As a complex systemic disease, primary liver cancer ranks third in death rate for solid tumors worldwide. Family with sequence similarity 111 member B (FAM111B), which was found to be aberrantly mutated in multiple cancers, is a candidate oncogene. We aimed to determine the function and mechanism of FAM111B in hepatocellular carcinoma (HCC). The expression of FAM111B was evaluated in HCC tissues, adjacent tissues, HCC cell lines. The impact of FAM111B on proliferation, invasion, apoptosis and EMT of HCC cells were detected by CCK-8, Transwell, flow cytometry and Western blot assays. The relationship between FAM111B and transforming acidic coiled-coil protein 3 (TACC3) was assessed by CoIP and Immunofluorescence (IF) staining assays. The effect of FAM111B on tumor growth was detected by using xenograft model of nude mice. The expression of FAM111B was upregulated in HCC tissues and cell lines, and the prognosis of HCC patients was worse in the high FAM111B expression group, and its expression level was associated with the TNM stage of HCC. FAM111B silencing inhibited HCC cell proliferation and invasion, EMT and induced apoptosis. Besides, TACC3 served as an interactor for FAM111B, which could enhance TACC3 expression, thus activing PI3K/AKT pathway. Rescue experiments revealed that elevated of TACC3 restored the inhibitory effect of FAM111B overexpression on the cell functions via PI3K/AKT pathway. In vivo, FAM111B inhibition hampered tumor growth and metastasis of HCC. This study highlighted a key player of FAM111B in modulating the malignant biological progression of HCC via TACC3/PI3K/AKT signaling pathway, displaying a potential therapeutic target for HCC.

Knockdown of TACC3 inhibits tumor cell proliferation and increases chemosensitivity in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant digestive tract tumor with limited clinical treatments. Transforming acidic coiled-coil-containing protein 3 (TACC3) is a component of the centrosome axis and a member of the TACC family, which affect mitosis and regulate chromosome stability and are involved in tumor development and progression. However, the role of TACC3 in PDAC remains elusive. In this study, by exploiting the TCGA database, we found that high TACC3 expression in PDAC is associated with poor prognosis. shRNA-mediated TACC3 knockdown caused S phase arrest of the cell cycle and inhibited proliferation in PDAC cell lines. Through RNA sequencing and protein co-immunoprecipitation combined with mass spectrometry, KIF11 was identified as a protein that interacts with TACC3. TACC3 stabilizes and regulates KIF11 protein expression levels in PDAC cells through physical interaction. Knockdown of TACC3 or KIF11 resulted in abnormal spindle formation during cell division both in vitro and in vivo. Pharmacological inhibition of TACC3 or KIF11 can suppress tumor cell proliferation and promote apoptosis. Our studies further demonstrated that high expression of TACC3 and KIF11 mediated the resistance of PDAC to gemcitabine, and deficiency of TACC3 or KIF11 increased the sensitivity of PDAC cells to chemotherapy. In conclusion, our study reveals the fundamental role of TACC3 expression in PDAC cell proliferation and chemoresistance, suggesting that TACC3 can be used as a molecular marker to evaluate the prognosis of PDAC.

Long noncoding RNAs (lncRNAs) in pancreatic cancer progression

Long noncoding RNAs (lncRNAs) are RNA molecules involved in gene regulation at transcriptional, post-transcriptional, and epigenetic levels. LncRNAs participate in regulating apoptosis and autophagy in pancreatic cancer (PCa) and can promote and/or decrease the proliferation rate of tumor cells. The metastasis of PCa cells is tightly regulated by lncRNAs and they can affect the mechanism of epithelial-mesenchymal transition (EMT) to modulate metastasis. The drug resistance of PCa cells, especially to gemcitabine, can be affected by lncRNAs. In addition, lncRNAs enriched in exosomes can be transferred among tumor cells to regulate their proliferation and metastasis. Antitumor compounds, such as curcumin and ginsenosides, can regulate lncRNA expression in PCa therapy. As we discuss here, the expression level of lncRNAs can be considered as both a diagnostic and prognostic tool in patients with PCa.

CERS6-AS1 promotes cell proliferation and represses cell apoptosis in pancreatic cancer via miR-195-5p/WIPI2 axis

Pancreatic cancer (PC) is a lethal malignancy that threatens human health. Long noncoding RNAs (lncRNAs) act as important mediators in PC development. Our study aimed to investigate the function and mechanism of lncRNA ceramide synthase 6 antisense RNA 1 (CERS6-AS1) in PC. As shown by RT-qPCR, CERS6-AS1 was significantly upregulated in PC cells and tissues. Silencing CERS6-AS1 suppressed PC cell viability and proliferation while enhancing cell apoptosis according to colony formation assays, EdU assays, and flow cytometry analyses. Mechanistically, CERS6-AS1 interacted with miR-195-5p to elevate the expression level of the WD repeat domain phosphoinositide interacting 2 (WIPI2), which is a downstream target gene of miR-195-5p in PC. Moreover, miR-195-5p expression was negatively associated with CERS6-AS1 expression (or WIPI2 expression) in PC tissues. Rescue assays revealed that WIPI2 overexpression rescued the effects of CERS6-AS1 deficiency on cell viability, proliferation, and apoptosis. In summary, CERS6-AS1 facilitates PC cell proliferation while inhibiting PC cell apoptosis by upregulating WIPI2 via miR-195-5p. This study might provide promising insight into the role of CERS6-AS1 in PC development.

AK098656: a new biomarker of coronary stenosis severity in hypertensive and coronary heart disease patients

BACKGROUND

AK098656 may be an adverse factor for coronary heart disease (CHD), especially in patients with hypertension. This study aimed to analyze the effect of AK098656 on CHD and CHD with various complications.

METHODS

A total of 117 CHD patients and 27 healthy control subjects were enrolled in the study. Plasma AK098656 expression was determined using the quantitative real-time polymerase chain reaction. Student's t-test was used to compare AK098656 expression levels in different groups. Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to quantify the discrimination ability between CHD patients and health controls and between CHD and CHD + complications patients. The relationship between AK098656 and coronary stenosis was analyzed using Spearman's correlation.

RESULTS

AK098656 expression was remarkably higher in CHD patients than in healthy controls (P = 0.03). The ROC curve revealed an effective predictive AK098656 expression value for CHD risk, with an AUC of 0.656 (95% CI 0.501-0.809). Moreover, AK098656 expression was increased in CHD + complications patients compared to CHD patients alone (P = 0.005), especially in patients with hypertension (CHD + hHTN, P = 0.030). The ROC curve revealed a predictive AK098656 prognostic value for discriminating between CHD and CHD + hHTN patients, with an AUC of 0.666 (95% CI 0.528-0.805). There was no significant difference in AK098656 expression in CHD patients with diabetes mellitus compared to CHD patients alone. In addition, AK098656 expression in CHD patients was positively correlated with stenosis severity (R = 0.261, P = 0.006).

CONCLUSION

AK098656 expression was significantly increased in patients with CHD, especially those with hypertension, and its expression level was positively correlated with the degree of coronary stenosis. This implied that AK098656 may be a risk factor for CHD and can potentially be applied in clinical diagnosis or provide a novel target for treatment.

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.

Epithelial to Mesenchymal Transition: Key Regulator of Pancreatic Ductal Adenocarcinoma Progression and Chemoresistance

Simple Summary

Pancreatic ductal adenocarcinoma’s (PDAC) dismal prognosis is associated with its aggressive biological behavior and resistance to chemotherapy. Epithelial to mesenchymal transition (EMT) has been recognized as a key driver of PDAC progression and development of drug resistance. EMT is a transient and reversible process leading to transdifferentiation of epithelial cells into a more mesenchymal phenotype. It is regulated by multiple signaling pathways that control the activity of a transcription factors network. Activation of EMT in pre-invasive stages of PDAC has been accused for early dissemination. Furthermore, it contributes to the development of intratumoral heterogeneity and drug resistance. This review summarizes the available data regarding signaling networks regulating EMT and describes the integral role of EMT in different aspects of PDAC pathogenesis.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignancies, characterized by aggressive biological behavior and a lack of response to currently available chemotherapy. Emerging evidence has identified epithelial to mesenchymal transition (EMT) as a key driver of PDAC progression and a central regulator in the development of drug resistance. EMT is a reversible transdifferentiation process controlled by complex interactions between multiple signaling pathways such as TGFb, Wnt, and Notch, which converge to a network of specific transcription factors. Activation of EMT transcriptional reprogramming converts cancer cells of epithelial differentiation into a more mesenchymal phenotypic state. EMT occurrence in pre-invasive pancreatic lesions has been implicated in early PDAC dissemination. Moreover, cancer cell phenotypic plasticity driven by EMT contributes to intratumoral heterogeneity and drug tolerance and is mechanistically associated with the emergence of cells exhibiting cancer stem cells (CSCs) phenotype. In this review we summarize the available data on the signaling cascades regulating EMT and the molecular isnteractions between pancreatic cancer and stromal cells that activate them. In addition, we provide a link between EMT, tumor progression, and chemoresistance in PDAC.

Aberration of lncRNA LINC00460 is a Promising Prognosis Factor and Associated with Progression of Clear Cell Renal Cell Carcinoma

Purpose

Long noncoding RNAs have been studied more and more as potential prognostic markers. However, the prognostic of LINC00460 in clear cell renal cell carcinoma (ccRCC) has not been explored. In this study, the potential role of LINC00460 was investigated in ccRCC.

Patients and Methods

One hundred thirteen pairs of ccRCC tissues and para-normal tissues were collected. The expressions of LINC00460 in these tissues and ccRCC cells were evaluated via qRT-PCR. The prognostic value of LINC00460 was accessed with the use of Kaplan–Meier analysis and Cox proportional hazards model analysis. The influence of LINC00460 on ccRCC cell proliferation, migration, and invasion was determined via cell counting kit-8 (CCK-8) and Transwell assays.

Results

The results revealed that LINC00460 was significantly enhanced in ccRCC tissues, as well as in ccRCC cell lines. The overexpression of LINC00460 was significantly associated with lymph node metastasis and TNM stage, and lead to poor overall survival. Knockdown of LINC00460 reduces the cell ability of proliferation, migration, and invasion. LINC00460 could sponge to miR-149-5p.

Conclusion

LINC00460 may be developed as a prognostic biomarker and molecular therapy target for ccRCC.

The impact of LncRNA dysregulation on clinicopathology and survival of pancreatic cancer: a systematic review and meta-analysis (PRISMA compliant)

Purpose

An increasing number of studies have reported a significant association between long non-coding RNAs (lncRNAs) dysregulation and pancreatic cancers. In the present study, we aimed to gather articles to evaluate the prognostic value of long non coding RNA in pancreatic cancer.

Experimental design

We systematically searched all eligible articles from databases of PubMed, Web of Science, and Scopus to meta-analysis of published articles and screen association of multiple lncRNAs expression with clinicopathology and/or survival of pancreatic cancer. The pooled hazard ratios (HRs) and their 95% confidence intervals (95% CIs) were used to analysis of overall survival, disease-free survival and progression-free survival were measured with a fixed or random effects model.

Results

A total of 39 articles were included in the present meta-analysis. Our results showed that dysregulation of lncRNAs were linked to overall survival (39 studies, 4736 patients HR = 0.41, 95% CI 0.25 ± 0.58, random-effects in pancreatic cancer. Moreover, altered lncRNAs were also contributed to progression-free survival (8 studies, 1180 patients HR: 1.88, 95% CI (1.35–2.62) and disease-free survival (2 studies, 285 patients, HR: 6.07, 95% CI 1.28–28.78). In addition, our findings revealed the association between dysregulated RNAs and clinicopathological features in this type of cancer.

Conclusions

In conclusion, dysregulated lncRNAs could be served as promising biomarkers for diagnosis and prognosis of pancreatic cancer.

lncRNA ANRIL aggravates the chemoresistance of pancreatic cancer cells to gemcitabine by targeting inhibition of miR-181a and targeting HMGB1-induced autophagy

Recent studies focus on long noncoding RNAs (lncRNA) as crucial regulators of cancer biology that contribute to essential cancer cell functions such as cell proliferation, apoptosis, and metastasis. In pancreatic cancer, several lncRNAs have been mentioned as important actors in tumorigenesis. However, the function of lncRNA ANRIL (named as ANRIL as follows) in pancreatic cancer has not been elucidated. In the present study, we show that ANRIL was up-regulated while miR-181a was down-regulated in pancreatic cancer tissues and HMGB1 was highly expressed. Knockdown of ANRIL in pancreatic cancer repressed cellular proliferation, invasion, migration, and reduced chemotherapy resistance to gemcitabine. ANRIL was negatively correlated with miR-181a, while overexpression of miR-181a could reverse the effect. For further mechanism research, we found that miR-181a aimed to HMGB1 which activated cell autophagy. Taken together, our results implicate that the ANRIL, by targeting miR-181a, activates the HMGB1-induced cell autophagy, which is thought to be critical for oncogenesis.

Low LINC01272 predicts poor prognosis of non-small cell lung cancer and its biological function in tumor cells by inhibiting miR-1303

Non-small cell lung cancer (NSCLC) is a malignant tumor associated with poor prognosis. The clinical value of long non-coding RNAs (lncRNAs) in the pathomechanism of various types of human malignancy has attracted increasing attention. The present study aimed to investigate the expression of LINC01272 in NSCLC and to determine its prognostic value and biological role. Tumor and adjacent non-tumor tissues from 108 patients with NSCLC and NSCLC cell lines were used in this study. The expression levels of LINC01272 and microRNA (miR)-1303 in tissues of patients and NSCLC cell lines were evaluated by reverse transcription quantitative PCR. The relationship between LINC01272 and the overall survival of patients with NSCLC was analyzed by Kaplan-Meier survival curve and log-rank test. Cox regression analysis confirmed the prognostic value of LINC01272 in patients with NSCLC. Cell Counting Kit-8 assay was used to evaluate the proliferation of NSCLC cells. The migration and invasion of NSCLC cells were determined using Transwell assays. The interaction between LINC01272 and miR-1303 in NSCLC was confirmed by dual-luciferase reporter assay. LINC01272 downregulation in NSCLC tissues was associated with worse overall survival in patients based on bioinformatics analysis. Furthermore, LINC01272 expression, which was decreased in NSCLC tumor tissues and NSCLC cells, was considered as an independent prognostic biomarker in NSCLC. In addition, LINC01272 overexpression inhibited NSCLC cell proliferation, migration and invasion. miR-1303 expression, which was increased in tumor tissues, was sponged by LINC01272 and negatively correlated with LINC01272 expression. miR-1303 expression reversed the inhibitory effects of LINC01272 on NSCLC cell function. In summary, the findings from this study suggested that LINC01272 expression, which was decreased in NSCLC tumor tissues and NSCLC cells, may be used as an independent prognostic biomarker for patients with NSCLC and that its overexpression may suppress NSCLC cell proliferation, migration and invasion by inhibiting miR-1303.

Regulation of Hippo, TGFβ/SMAD, Wnt/β-Catenin, JAK/STAT, and NOTCH by Long Non-Coding RNAs in Pancreatic Cancer

Rapidly evolving and ever-increasing knowledge of the molecular pathophysiology of pancreatic cancer has leveraged our understanding altogether to a next level. Compared to the exciting ground-breaking discoveries related to underlying mechanisms of pancreatic cancer onset and progression, however, there had been relatively few advances in the therapeutic options available for the treatment. Since the discovery of the DNA structure as a helix which replicates semi-conservatively to pass the genetic material to the progeny, there has been conceptual refinement and continuous addition of missing pieces to complete the landscape of central dogma. Starting from transcription to translation, modern era has witnessed non-coding RNA discovery and central role of these versatile regulators in onset and progression of pancreatic cancer. Long non-coding RNAs (lncRNAs) have been shown to act as competitive endogenous RNAs through sequestration and competitive binding to myriad of microRNAs in different cancers. In this article, we set spotlight on emerging evidence of regulation of different signaling pathways (Hippo, TGFβ/SMAD, Wnt/β-Catenin, JAK/STAT and NOTCH) by lncRNAs. Conceptual refinements have enabled us to understand how lncRNAs play central role in post-translational modifications of various proteins and how lncRNAs work with epigenetic-associated machinery to transcriptionally regulate gene network in pancreatic cancer.

Long noncoding RNAs: role and contribution in pancreatic cancer

Noncoding RNAs are proclaimed to be expressed in various cancer types and one such type is found to be pancreatic ductal adenocarcinoma (PDAC). The long noncoding RNAs (LncRNAs) affect the migration, invasion, and growth of tumor cells by playing important roles in the process of epigenesis, post-transcription, and transcriptional regulation along with the maintenance of apoptosis and cell cycle. It is quite subtle whether the alterations in lncRNAs would impact PDAC progression and development. This review throws a spotlight on the lncRNAs associated with tumor functions: MALAT-1, HOTAIR, HOXA13, H19, LINC01559, LINC00460, SNHG14, SNHG16, DLX6-AS1, MSC-AS1, ABHD11-AS1, DUXAP8, DANCR, XIST, DLEU2, etc. are upregulated lncRNAs whereas GAS5, HMlincRNA717, MIAT, LINC01111, lncRNA KCNK15-AS1, etc. are downregulated lncRNAs inhibiting the invasion and progression of PDAC. These data provided helps in the assessment of lncRNAs in the development, metastasis, and occurrence of PDAC and also play a vital role in the evolution of biomarkers and therapeutic agents for the treatment of PDAC.

LINC00671 suppresses cell proliferation and metastasis in pancreatic cancer by inhibiting AKT and ERK signaling pathway

Long noncoding RNAs (lncRNAs) represent an emerging field of tumor biology, playing essential roles in cancer cell proliferation, invasion, and metastasis. However, the overall functional and clinical significance of most lncRNAs in pancreatic cancer is not thoroughly understood. Here, we described most of the lncRNAs with aberrant expression patterns in pancreatic cancer as detected by microarray. Quantitative real-time polymerase chain reaction further verified that the expression of LINC00671 was decreased in pancreatic cancer cell lines and patient samples. Furthermore, lower LINC00671 expression was associated with reduced tumor differentiation, aggressiveness, and poor prognosis. Functionally, LINC00671 overexpression inhibited pancreatic cancer cell proliferation, invasion, and migration in vitro, and reduced tumor growth in vivo. LINC00671 is mainly located in the cytoplasm. RNA sequencing and bioinformatics analyses indicated that LINC00671 binds to multiple miRNAs and therefore could be involved in multiple tumor-associated pathways, such as the AMPK signaling pathway and PI3K-Akt signaling pathway. Western blotting and immunohistochemistry further confirmed that LINC00671 overexpression suppressed the AKT, ERK, and epithelial-mesenchymal transition pathways. Overall, these results indicated that LINC00671 acts as a novel tumor suppressor in pancreatic cancer. Our findings may provide a new potential target for the treatment of pancreatic cancer.

Nine-long non-coding ribonucleic acid signature can improve the survival prediction of colorectal cancer

BACKGROUND

Investigating molecular biomarkers that accurately predict prognosis is of considerable clinical significance. Accumulating evidence suggests that long non-coding ribonucleic acids (lncRNAs) are frequently aberrantly expressed in colorectal cancer (CRC).

AIM

To elucidate the prognostic function of multiple lncRNAs serving as biomarkers in CRC.

METHODS

We performed lncRNA expression profiling using the lncRNA mining approach in large CRC cohorts from The Cancer Genome Atlas (TCGA) database. Receiver operating characteristic analysis was performed to identify the optimal cutoff point at which patients could be classified into the high-risk or low-risk groups. Based on the Cox coefficient of the individual lncRNAs, we identified a nine-lncRNA signature that was associated with the survival of CRC patients in the training set (n = 175). The prognostic value of this nine-lncRNA signature was validated in the testing set (n = 174) and TCGA set (n = 349). The prognostic models, consisting of these nine CRC-specific lncRNAs, performed well for risk stratification in the testing set and TCGA set. Time-dependent receiver operating characteristic analysis indicated that this predictive model had good performance.

RESULTS

Multivariate Cox regression and stratification analysis demonstrated that this nine-lncRNA signature was independent of other clinical features in predicting overall survival. Functional enrichment analysis of Kyoto Encyclopedia of Genes and Genomes pathways and Gene Ontology terms further indicated that these nine prognostic lncRNAs were closely associated with carcinogenesis-associated pathways and biological functions in CRC.

CONCLUSION

A nine-lncRNA expression signature was identified and validated that could improve the prognosis prediction of CRC, thereby providing potential prognostic biomarkers and efficient therapeutic targets for patients with CRC.

LINC01232 Sponges Multiple miRNAs and Its Clinical Significance in Pancreatic Adenocarcinoma Diagnosis and Prognosis

Background:

Long noncoding RNAs have been demonstrated to play important roles in different kinds of human malignancy. The purpose of this study was to evaluate the diagnostic and prognostic value of long intergenic non-protein coding RNA 1232 (LINC01232) in patients with pancreatic adenocarcinoma (PAAD) and further explore the clinical significance of the potential miRNAs that might be sponged by LINC01232.

Methods:

The potential target miRNAs that might be sponged by LINC01232 were analyzed using bioinformatics analysis. The Real-Time quantitative PCR was adopted to measure the relative expression of LINC01232 and target miRNAs in PAAD serum and tissue samples. The diagnostic and prognostic value of LINC01232 was evaluated using the receiver operating characteristic analysis and Kaplan-Meier survival analysis, respectively.

Results:

LINC01232 expression was upregulated in PAAD serum and tissues and associated with patients’ TNM stage. Serum LINC01232 expression had diagnostic value, and the high levels of LINC01232 could predict unfavorable prognosis in PAAD patients. miR-204-5p, miR-370-5p and miR-654-3p were proposed as 3 targets of LINC01232 in PAAD, and their decreased expression levels in PAAD patients showed certain clinical significance in diagnosis and prognosis.

Conclusion:

The data of this study revealed that LINC01232 expression is upregulated in PAAD serum and tissue samples with considerable diagnostic and prognostic significance. In addition, miR-204-5p, miR-370-5p and miR-654-3p may be sponged by LINC01232 in PAAD, which also show potencies in PAAD diagnosis and prognosis.

LINC01089 is a tumor-suppressive lncRNA in gastric cancer and it regulates miR-27a-3p/TET1 axis

Background

Gastric cancer (GC) is one of the most common malignancies around the world. Recently, the role of long non-coding RNA (lncRNA) in cancer biology has become a hot research topic. This work aimed to explore the biological function and underlying mechanism of LINC01089 in GC.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to investigate the expression of LINC01089 in GC tissues and cells. The relationship between the expression level of LINC01089 and the clinicopathological parameters of GC was assessed. Cell models of LINC01089 overexpression, LINC01089 knockdown, miR-27a-3p overexpression, and miR-27a-3p inhibition were established by transfection. CCK-8 assay, BrdU assay, and Transwell assay were utilized to investigate the malignant biological behaviors of GC cell lines after transfection. Dual luciferase activity reporter assay, Pearson’s correlation analysis, and Western blot were utilized to the regulatory relationships among LINC01089, miR-27a-3p and tet methylcytosine dioxygenase 1 (TET1).

Result

LINC01089 down-regulation was observed in GC tissues and cell lines. Low expression level of LINC01089 in GC tissues was markedly linked to larger tumor size, higher T stage, as well as lymphatic metastasis of the patients. Functional experiments implied that LINC01089 overexpression impeded the proliferation, migration, as well as invasion of GC cells, whereas LINC01089 knockdown promoted the above malignant phenotypes. Additionally, up-regulation of miR-27a-3p was also observed in GC tissues. Functional experiments also showed that, miR-27a-3p overexpression boosted the malignant biological behaviors of GC cells; on the contrast, these phenotypes were impeded by miR-27a-3p inhibition. Moreover, LINC01089 interacted with and repressed miR-27a-3p, and miR-27a-3p antagonized the impact of LINC01089 on GC cells. Additionally, TET1 was verified as a target gene of miR-27a-3p, and could be positively regulated by LINC01089.

Conclusion

LINC01089 impedes the proliferation, migration, and invasion of GC cells by adsorbing miR-27a-3p and up-regulating the expression of TET1.

Progress of long noncoding RNAs in anti-tumor resistance

The resistance of cancer cells to anti-cancer drugs is an important reason for the failure of treatment. Overcoming drug resistance can achieve long-lasting and efficient cancer treatment. Long non-coding RNA (lncRNA) is a class of RNA molecules that does not encode protein and has more than 200 nucleotides. LncRNA not only has a regulatory role in the occurrence and development of malignant tumors, but also has been found to have a potential impact on anti-tumor resistance. Abnormal expression of lncRNA can cause tumor cells to develop resistance to anti-tumor drugs. This article reviews the recent research progress of lncRNA in various tumor resistances and the mechanism of lncRNA acting on tumor drug resistance.

LncRNA PITPNA-AS1 boosts the proliferation and migration of lung squamous cell carcinoma cells by recruiting TAF15 to stabilize HMGB3 mRNA

Plenty of reports have probed the involvement of abnormally expressed lncRNAs in multiple cancers, including lung squamous cell carcinoma (LUSC). Through online database GEPIA, lncRNA PITPNA antisense RNA 1 (PITPNA-AS1) was highly expressed in LUSC samples, and these tendency was further affirmed in LUSC cells. The aim of current study was to investigate the related mechanism of PITPNA-AS1 in LUSC. Functional experiments verified that depletion of PITPNA-AS1 hampered the proliferative and migratory abilities, but accelerated apoptosis of LUSC cells. Additionally, we observed the increased expression of HMGB3 and its positive correlation with PITPNA-AS1 in LUSC samples. Interestingly, PITPNA-AS1 mainly located in the cytosol of LUSC cells, and also affected mRNA stability of HMGB3. Furthermore, the repressed mRNA stability of HMGB3 by PITPNA-AS1 via TAF15 was exposed through mechanism experiments. The mediatory function of PITPNA-AS1 on HMGB3 was validated via rescue assays. All in all, PITPNA-AS1 promoted the proliferation and migration of LUSC cells via stabilizing HMGB3 by TAF15. In conclusion, our study displayed a novel mechanism underlying PITPNA-AS1 in LUSC cells.

cfRNAs as biomarkers in oncology - still experimental or applied tool for personalized medicine already?

Currently, the challenges of contemporary oncology are focused mainly on the development of personalized medicine and precise treatment, which could be achieved through the use of molecular biomarkers. One of the biological molecules with great potential are circulating free RNAs (cfRNAs) which are present in various types of body fluids, such as blood, serum, plasma, and saliva. Also, different types of cfRNA particles can be distinguished depending on their length and function: microRNA (miRNA), PIWI-interacting RNA (piRNA), tRNA-derived RNA fragments (tRFs), circular RNA (circRNA), long non-coding RNA (lncRNA), and messenger RNA (mRNA). Moreover, cfRNAs occur in various forms: as a free molecule alone, in membrane vesicles, such as exosomes, or in complexes with proteins and lipids. One of the modern approaches for monitoring patient's condition is a "liquid biopsy" that provides a non-invasive and easily available source of circulating RNAs. Both the presence of specific cfRNA types as well as their concentration are dependent on many factors including cancer type or even reaction to treatment. Despite the possibility of using circulating free RNAs as biomarkers, there is still a lack of validated diagnostic panels, defined protocols for sampling, storing as well as detection methods. In this work we examine different types of cfRNAs, evaluate them as possible biomarkers, and analyze methods of their detection. We believe that further research on cfRNA and defining diagnostic panels could lead to better and faster cancer identification and improve treatment monitoring.

A novel antisense lncRNA NT5E promotes progression by modulating the expression of SYNCRIP and predicts a poor prognosis in pancreatic cancer

A novel antisense lncRNA NT5E was identified in a previous microarray that was clearly up‐regulated in pancreatic cancer (PC) tissues. However, its biological function remains unclear. Thus, we aimed to explore its function and clinical significance in PC. The lncNT5E expression was determined in PC specimens and cell lines. In vitro and in vivo studies detected the impact of lncNT5E depletion on PC cell proliferation, migration and invasion. Western blotting investigated the epithelial‐mesenchymal transition (EMT) markers. The interaction between lncNT5E and the promoter region of SYNCRIP was detected by dual‐luciferase reporter assay. The role of lncNT5E in modulating SYNCRIP was investigated in vitro. Our results showed that lncNT5E was significantly up‐regulated in PC tissues and cell lines and associated with poor prognosis. LncNT5E depletion inhibited PC cell proliferation, migration, invasion and EMT in vitro and caused tumorigenesis arrest in vivo. Furthermore, SYNCRIP knockdown had effects similar to those of lncNT5E depletion. A significant positive relationship was observed between lncNT5E and SYNCRIP. Moreover, the dual‐luciferase reporter assays indicated that lncNT5E depletion significantly inhibited SYNCRIP promoter activity. Importantly, the malignant phenotypes of lncNT5E depletion were rescued by overexpressing SYNCRIP. In conclusion, lncNT5E predicts poor prognosis and promotes PC progression by modulating SYNCRIP expression.

Molecular Screening for Nigericin Treatment in Pancreatic Cancer by High-Throughput RNA Sequencing

Objectives: Nigericin, an antibiotic derived from Streptomyces hygroscopicus, has been proved to exhibit promising anti-cancer effects on a variety of cancers. Our previous study investigated the potential anti-cancer properties in pancreatic cancer (PC), and demonstrated that nigericin could inhibit the cell viabilities in concentration- and time-dependent manners via differentially expressed circular RNAs (circRNAs). However, the knowledge of nigericin associated with long non-coding RNA (lncRNA) and mRNA in pancreatic cancer (PC) has not been studied. This study is to elucidate the underlying mechanism from the perspective of lncRNA and mRNA.

Methods: The continuously varying molecules (lncRNAs and mRNAs) were comprehensively screened by high-throughput RNA sequencing.

Results: Our data showed that 76 lncRNAs and 172 mRNAs were common differentially expressed in the nigericin anti-cancer process. Subsequently, the bioinformatics analyses, including Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, coding and non-coding co-expression network, cis- and trans-regulation predictions and protein-protein interaction (PPI) network, were applied to annotate the potential regulatory mechanisms among these coding and non-coding RNAs during the nigericin anti-cancer process.

Conclusions: These findings provided new insight into the molecular mechanism of nigericin toward cancer cells, and suggested a possible clinical application in PC.

LncRNA AFAP1-AS1 contributes to the progression of endometrial carcinoma by regulating miR-545-3p/VEGFA pathway

Endometrial carcinoma (EC) accounts for 20%-30% of female reproductive tumors. Targeted therapy for EC has shown great advantages with small side effects. To improve the survival of EC patients, more new therapeutic targets need to be found. Long non-coding RNAs (lncRNAs) are series of RNAs with over 200 nucleotides that regulate various cellular functions. LncRNA actin filamentin-1 antisense RNA 1 (AFAP1-AS1) is involved in the development of a variety of cancers, such as pancreas ductal adenocarcinoma and esophageal adenocarcinoma. However, it is not clear whether AFAP1-AS1 has any effects on EC or the exact regulatory mechanism. Herein, we found the high expression of AFAP1-AS1 in human EC tissues, and AFAP1-AS1 was correlated with EC patients' prognosis and clinical features. AFAP-AS1 could affect EC cell proliferation, migration, and invasion, and contributed to endothelial cell angiogenesis. We further showed that AFAP-AS1 could promote the expression of VEGFA through the adsorption of miR-545-3p, thus promoting the angiogenesis and invasion of EC, and contribute to tumor growth and metastasis in vivo. Thus, we thought AFAP1-AS1 had the potential to serve as an EC therapeutic target.

RNA Demethylase ALKBH5 Selectively Promotes Tumorigenesis and Cancer Stem Cell Self-Renewal in Acute Myeloid Leukemia

N⁶-methyladenosine (m⁶A), the most abundant internal modification in mRNA, has been implicated in tumorigenesis. As an m⁶A demethylase, ALKBH5 has been shown to promote the development of breast cancer and brain tumors. However, in acute myeloid leukemia (AML), ALKBH5 was reported to be frequently deleted, implying a tumor-suppressor role. Here, we show that ALKBH5 deletion is rare in human AML; instead, ALKBH5 is aberrantly overexpressed in AML. Moreover, its increased expression correlates with poor prognosis in AML patients. We demonstrate that ALKBH5 is required for the development and maintenance of AML and self-renewal of leukemia stem/initiating cells (LSCs/LICs) but not essential for normal hematopoiesis. Mechanistically, ALKBH5 exerts tumor-promoting effects in AML by post-transcriptional regulation of its critical targets such as TACC3, a prognosis-associated oncogene in various cancers. Collectively, our findings reveal crucial functions of ALKBH5 in leukemogenesis and LSC/LIC self-renewal/maintenance and highlight the therapeutic potential of targeting the ALKBH5/m⁶A axis.

The multifaceted roles of long noncoding RNAs in pancreatic cancer: an update on what we know

Pancreatic cancer (PC) is one of the leading causes of cancer-related deaths worldwide. Due to the shortage of effective biomarkers for predicting survival and diagnosing PC, the underlying mechanism is still intensively investigated but poorly understood. Long noncoding RNAs (lncRNAs) provide biological functional diversity and complexity in protein regulatory networks. Scientific studies have revealed the emerging functions and regulatory roles of lncRNAs in PC behaviors. It is worth noting that some in-depth studies have revealed that lncRNAs are significantly associated with the initiation and progression of PC. As lncRNAs have good properties for both diagnostic and prognostic prediction due to their translation potential, we herein address the current understanding of the multifaceted roles of lncRNAs as regulators in the molecular mechanism of PC. We also discuss the possibility of using lncRNAs as survival biomarkers and their contributions to the development of targeted therapies based on the literature. The present review, based on what we know about current research findings, may help us better understand the roles of lncRNAs in PC.

An Integrated Analysis of mRNA and lncRNA Expression Profiles Indicates Their Potential Contribution to Brown Fat Dysfunction With Aging

Brown adipose tissue (BAT) can convert fatty acids and glucose into heat, exhibiting the potential to combat obesity and diabetes. The mass and activity of BAT gradually diminishes with aging. As a newly found regulator of gene expression, long non-coding RNAs (lncRNAs) exhibit a wide range of functions in life processes. However, whether long non-coding RNA (lncRNA) involves in BAT dysfunction with aging is still unclear. Here, using RNA-sequencing technology, we identified 3237 messenger RNAs (mRNAs) and 1312 lncRNAs as differentially expressed in BAT of 10-months-old mice compared with 6- to 8-week-old. The protein-protein interaction network and k-score analysis revealed that the core mRNAs were associated with two important aging-related pathways, including cell cycle and p53 signaling pathway. Gene set enrichment analysis indicated that these mRNAs might participate in lipid metabolism and brown fat dysfunction. Functional enrichment analyses demonstrated that dysregulated lncRNAs were associated with mitochondria, regulation of cellular senescence, cell cycle, metabolic and p53 signaling pathways. Moreover, we revealed that two lncRNAs (NONMMUT024512 and n281160) may involve in the regulation of their adjacent gene peroxisome proliferator-activated receptor alpha (Pparα), a thermogenesis regulator. Collectively, these results lay a foundation for extensive studies on the role of lncRNAs in age-related thermogenic degradation.

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.

Long noncoding RNA LINC00473 drives the progression of pancreatic cancer via upregulating programmed death-ligand 1 by sponging microRNA-195-5p

Pancreatic cancer (PC) is a great health burden to patients owing to its poor overall survival rate. Long noncoding RNAs (lncRNAs) interact with microRNAs (miRs) to participate in tumorigenesis. Therefore, we aim to uncover the role and related mechanism of LINC00473 in PC through the modulation of miR-195-5p and programmed death-ligand 1 (PD-L1). Increased LINC00473 and PD-L1 but declined miR-195-5p were determined in PC tissues and cell lines, and it was found that LINC00473 mainly situated in the cytoplasm. Also, miR-195-5p was verified to bind with both LINC00473 and PD-L1. Next, with the aim to examine the ability of LINC00473, miR-195-5p, and PD-L1 on the PC progression, the expression of LINC00473, miR-195-5p and PD-L1 were altered with mimics, inhibitors, overexpression vectors or siRNAs in PC cells and cocultured CD8⁺ T cells. It was demonstrated that LINC00473 sponged miR-195-5p to upregulate PD-L1 expression. More important, the obtained results revealed that LINC00473 silencing or miR-195-5p upregulation elevated the expression of Bcl-2 associated X protein (Bax), interferon (IFN)-γ, and interleukin (IL)-4 but reduced the expression of B-cell lymphoma-2 (Bcl-2), matrix metalloproteinase (MMP)-2, MMP-9, and IL-10, thus inducing the enhancement of the apoptosis as along with the inhibition of proliferation, invasion, and migration of the PC cells. LINC00473 silencing or miR-195-5p elevation activated the CD8⁺ T cells. Taken together, LINC00473 silencing blocked the PC progression through enhancing miR-195-5p-targeted downregulation of PD-L1. This finding offers new therapeutic options for treating this devastating disease.

STAT3-induced upregulation of lncRNA ABHD11-AS1 promotes tumour progression in papillary thyroid carcinoma by regulating miR-1301-3p/STAT3 axis and PI3K/AKT signalling pathway

Objectives

Emerging evidences indicated the importance of long non‐coding RNAs (lncRNAs) in the tumorigenesis and deterioration of malignant tumours. To our knowledge, the study about lncRNAs in papillary thyroid carcinoma (PTC) is still inadequate. ABHD11‐AS1 was highly expressed in the PTC samples of The Cancer Genome Atlas database. This study focused on the biological function and mechanism of lncRNA ABHD11‐AS1 in PTC.

Materials and methods

qRT‐PCR analysis was used to examine the expression of ABHD11‐AS1 in PTC tissues and cell lines. The prognostic significance of ABHD11‐AS1 for the patients with PTC was analysed with Kaplan‐Meier analysis. The effects of ABHD11‐AS1 knockdown on the cell proliferation and metastasis were evaluated by in vitro functional assays and in vivo experiments. The molecular mechanism which contributed to the oncogenic role of ABHD11‐AS1 in PTC was explored by conducting mechanism experiments. Rescue assays were carried out for final demonstration.

Results

High expression of ABHD11‐AS1 predicted poor prognosis for patients with PTC and promoted cell proliferation and metastasis in vitro and in vivo. ABHD11‐AS1 was activated by the transcription factor STAT3. ABHD11‐AS1 positively regulated PI3K/AKT signalling pathway. ABHD11‐AS1 acted as a competitive endogenous (ce) RNA to upregulate STAT3 by sponging miR‐1301‐3p.

Conclusions

STAT3‐induced lncRNA ABHD11‐AS1 promoted PTC progression by regulating PI3K/AKT signalling pathway and miR‐1301‐3p/STAT3 axis.