High lncRNA HULC expression is associated with poor prognosis and promotes tumor progression by regulating epithelial-mesenchymal transition in prostate cancer

A thorough understanding of the role of lncRNA in prostate cancer pathogenesis; Current knowledge and future research directions

In the entire world, prostate cancer (PCa) is one of the most common and deadly cancers. Treatment failure is still common among patients, despite PCa diagnosis and treatment improvements. Inadequate early diagnostic markers and the emergence of resistance to conventional therapeutic approaches, particularly androgen-deprivation therapy, are the causes of this. Long non-coding RNAs (lncRNAs), as an essential group of regulatory molecules, have been reported to be dysregulated through prostate tumorigenesis and hold great promise as diagnostic targets. Besides, lncRNAs regulate the malignant features of PCa cells, such as proliferation, invasion, metastasis, and drug resistance. These multifunctional RNA molecules interact with other molecular effectors like miRNAs and transcription factors to modulate various signaling pathways, including AR signaling. This study aimed to compile new knowledge regarding the role of lncRNA through prostate tumorigenesis in terms of their effects on the various malignant characteristics of PCa cells; in light of these characteristics and the significant potential of lncRNAs as diagnostic and therapeutic targets for PCa. AVAILABILITY OF DATA AND MATERIALS: Not applicable.

The Role of Long Non-Coding RNAs in Epithelial-Mesenchymal Transition-Related Signaling Pathways in Prostate Cancer

Prostate cancer (PCa) is one of the most common male malignancies with frequent remote invasion and metastasis, leading to high mortality. Epithelial-mesenchymal transition (EMT) is a fundamental process in embryonic development and plays a key role in tumor proliferation, invasion and metastasis. Numerous long non-coding RNAs (lncRNAs) could regulate the occurrence and development of EMT through various complex molecular mechanisms involving multiple signaling pathways in PCa. Given the importance of EMT and lncRNAs in the progression of tumor metastasis, we recapitulate the research progress of EMT-related signaling pathways regulated by lncRNAs in PCa, including AR signaling, STAT3 signaling, Wnt/β-catenin signaling, PTEN/PI3K/AKT signaling, TGF-β/Smad and NF-κB signaling pathways. Furthermore, we summarize four modes of how lncRNAs participate in the EMT process of PCa via regulating relevant signaling pathways.

Targeting autophagy in prostate cancer: preclinical and clinical evidence for therapeutic response

Prostate cancer is a leading cause of death worldwide and new estimates revealed prostate cancer as the leading cause of death in men in 2021. Therefore, new strategies are pertinent in the treatment of this malignant disease. Macroautophagy/autophagy is a “self-degradation” mechanism capable of facilitating the turnover of long-lived and toxic macromolecules and organelles. Recently, attention has been drawn towards the role of autophagy in cancer and how its modulation provides effective cancer therapy. In the present review, we provide a mechanistic discussion of autophagy in prostate cancer. Autophagy can promote/inhibit proliferation and survival of prostate cancer cells. Besides, metastasis of prostate cancer cells is affected (via induction and inhibition) by autophagy. Autophagy can affect the response of prostate cancer cells to therapy such as chemotherapy and radiotherapy, given the close association between autophagy and apoptosis. Increasing evidence has demonstrated that upstream mediators such as AMPK, non-coding RNAs, KLF5, MTOR and others regulate autophagy in prostate cancer. Anti-tumor compounds, for instance phytochemicals, dually inhibit or induce autophagy in prostate cancer therapy. For improving prostate cancer therapy, nanotherapeutics such as chitosan nanoparticles have been developed. With respect to the context-dependent role of autophagy in prostate cancer, genetic tools such as siRNA and CRISPR-Cas9 can be utilized for targeting autophagic genes. Finally, these findings can be translated into preclinical and clinical studies to improve survival and prognosis of prostate cancer patients.

• Prostate cancer is among the leading causes of death in men where targeting autophagy is of importance in treatment;

• Autophagy governs proliferation and metastasis capacity of prostate cancer cells;

• Autophagy modulation is of interest in improving the therapeutic response of prostate cancer cells;

• Molecular pathways, especially involving non-coding RNAs, regulate autophagy in prostate cancer;

• Autophagy possesses both diagnostic and prognostic roles in prostate cancer, with promises for clinical application.

Bioinformatics analysis and experimental verification of five metabolism-related lncRNAs as prognostic models for hepatocellular carcinoma

BACKGROUND

The number of patients with hepatocellular carcinoma (HCC) is showing a growing trend all over the world. The metabolic microenvironment has been shown to play a key role in the pathogenesis of HCC in recent studies. The expression of metabolites and metabolic processes in tumor cells can be regulated by gene regulation mediated by long non-coding RNAs (lncRNAs), the abnormal expression of which is closely related to tumor occurrence and metastasis. However, the fundamental mechanism of applying metabolism-related lncRNAs to predicting HCC is still unclear.

METHODS

With the complete RNA sequence data and clinical data obtained from The Cancer Genome Atlas database and metabolism-related genes downloaded from the Kyoto Encyclopedia of Genes and Genomes database, with false discovery rate < 0.001, log fold change > 1.5 selected as the screening criteria for lncRNA, the relationship between the expression level of metabolism-related LncRNAs (MRLs) and the overall survival rate was determined by the Univariate Cox regression analyses with the establishment of the metabolic prognosis model by the application of Multivariate Cox regression analyses, revealing the different biological processes and signaling pathways in both high-risk groups and low-risk groups by Gene Ontology, Kyoto Encyclopedia of Genes and Genomes enrichment analysis, and gene set enrichment analysis, leading the expression of lncRNA to be assessed by the reverse transcription-polymerase chain reaction results.

RESULTS

The overall survival rate of HCC patients is significantly correlated with signature of 5-MRLs. The prognosis characteristics of lncRNA reveal the relatively high death rate of patients in the high-risk groups, with the predicted signals by functional and pathway enrichment analysis related to biosynthesis, metabolic process, and metabolic pathway, with the prognostic characteristics of 5-MRLs by the combined analysis showing that it is an independent factor of HCC superior to the traditional clinical indicators in predicting the prognosis. A trend of high-expression was shown in MRLs in tumors by reverse transcription-polymerase chain reaction.

CONCLUSION

The new 5-MRLs as potential biomarkers provide more powerful prognostic information for HCC patients. In the future clinical treatment of HCC, it will provide doctors with more methods.

Targeting long non coding RNA by natural products: Implications for cancer therapy

In spite of achieving substantial progress in its therapeutic strategies, cancer-associated prevalence and mortality are persistently rising globally. However, most malignant cancers either cannot be adequately diagnosed at the primary phase or resist against multiple treatments such as chemotherapy, surgery, radiotherapy as well as targeting therapy. In recent decades, overwhelming evidences have provided more convincing words on the undeniable roles of long non-coding RNAs (lncRNAs) in incidence and development of various cancer types. Recently, phytochemical and nutraceutical compounds have received a great deal of attention due to their inhibitory and stimulatory effects on oncogenic and tumor suppressor lncRNAs respectively that finally may lead to attenuate various processes of cancer cells such as growth, proliferation, metastasis and invasion. Therefore, application of phytochemicals with anticancer characteristics can be considered as an innovative approach for treating cancer and increasing the sensitivity of cancer cells to standard prevailing therapies. The purpose of this review was to investigate the effect of various phytochemicals on regulation of lncRNAs in different human cancer and evaluate their capabilities for cancer treatment and prevention.

β-Elemene suppresses tumor growth of diffuse large B-cell lymphoma through regulating lncRNA HULC-mediated apoptotic pathway

Background: Diffuse large B-cell lymphoma (DLBCL) is considered the most common aggressive subtype of lymphoma. A number of DLBCL patients fail to achieve a response to currently available therapies or develop resistance. β-Elemene is derived from herb Curcuma wenyujin, and exhibits anti-tumor activity in both solid and non-solid tumors through modulating several molecular signaling pathways. We aimed to explore the role of β-elemene in DLBCL treatment and elucidate the involved mechanism.

Materials and methods: Cell viability, apoptosis and expressions of related proteins were assessed and in vivo study were performed to determine the tumor suppressive effect of β-elemene and explore the molecular mechanisms.

Results: β-Elemene significantly suppressed the viability of DLBCL cells, and β-elemene down-regulated the lncRNA HULC expression and regulated key pro-apoptotic and anti-apoptotic proteins to induce significant apoptosis of DLBCL cells. HULC overexpression could decrease the β-elemene induced apoptosis, while HULC knockdown increased the apoptosis in DLBCL cells. In vivo study further confirmed that β-elemene could suppress the growth of DLBCL xenograft and regulate the HULC expression and the critical proteins of the apoptotic pathway.

Conclusion: β-Elemene performs as a tumor suppressor and modulator of HULC-mediated apoptotic pathway in DLBCL and will be an alternative candidate for clinical application.

LncRNA BLACAT1 Promotes Proliferation, Migration and Invasion of Prostate Cancer Cells via Regulating miR-29a-3p/DVL3 Axis

Background:

Long non-coding RNA bladder cancer associated transcript 1 (BLACAT1) is oncogenic in several types of cancers. However, little is known concerning its expression and function in prostate cancer.

Methods:

Paired prostate cancer samples were collected, and the expression levels of BLACAT1, miR-29a-3p and disheveled segment polarity protein 3 (DVL3) were examined by quantitative real-time polymerase chain reaction (qRT-PCR); BLACAT1 shRNAs were transfected into PC-3 and LNCaP cell lines, and proliferative ability was detected by cell counting kit-8 (CCK-8) assay; qRT-PCR and Western blot were used to analyze the changes of miR-29a-3p and DVL3; dual-luciferase reporter gene assay was used to determine the regulatory relationships between miR-29a-3p and BLACAT1, and miR-29a-3p and DVL3.

Results:

BLACAT1 expression was significantly up-regulated in cancerous tissues of prostate cancer samples and positively correlated with the expression of DVL3, while negatively associated with miR-29a-3p. After the transfection of BLACAT1 shRNAs into prostate cancer cells, the proliferative ability and metastatic ability of cancer cells were significantly inhibited; BLACAT1 shRNAs could reduce the expression of DVL3 on both mRNA and protein expressions levels, the luciferase activity of BLACAT1 reporter was inhibited by miR-29a-3p, and DVL3 was validated as a target gene of miR-29a-3p.

Conclusion:

BLACAT1 expression is abnormally up-regulated in prostate cancer tissues. BLACAT1 can modulate the proliferative and metastatic ability of prostate cancer cells and have the potential to be the “ceRNA” to regulate the expression of DVL3 by sponging miR-29a-3p.

Long noncoding RNA SNHG20 promotes prostate cancer progression via upregulating DDX17

INTRODUCTION

Accumulating evidence has revealed the critical roles of long noncoding RNAs (lncRNAs) in various cancers. LncRNA SNHG20 has been shown to be a cancer-associated lncRNA in several cancers with diverse mechanisms. However, the clinical references, biological roles, and mechanisms of action of SNHG20 in prostate cancer (PCa) are still unclear.

MATERIAL AND METHODS

The expression of SNHG20 in PCa tissues and cell lines was detected by RT-qPCR. The correlations between SNHG20 expression and clinicopathological features were analyzed by χ² test. The roles of SNHG20 in PCa cell proliferation and migration were detected by CCK-8, EdU incorporation, and transwell assays. The regulatory mechanisms of SNHG20 on DDX17 were detected by dual luciferase reporter assay, RT-qPCR, and western blot.

RESULTS

SNHG20 is highly expressed in PCa tissues and cell lines. High expression of SNHG20 is positively correlated with high Gleason score and advanced tumor stage. Functional experiments revealed that overexpression of SNHG20 promotes PCa cell proliferation and migration. SNHG20 knockdown represses PCa cell proliferation and migration. Mechanistically, SNHG20 was verified to act as a competing endogenous RNA (ceRNA) to upregulate DDX17. DDX17 is also highly expressed and has oncogenic roles in PCa. Furthermore, the expression of DDX17 is significantly positively correlated with that of SNHG20 in PCa tissues. Depletion of DDX17 reverses the oncogenic roles of SNHG20 in PCa.

CONCLUSIONS

These data showed that SNHG20 promotes PCa cell proliferation and migration via acting as a ceRNA to upregulate DDX17. This study also suggested that SNHG20 may be a potential novel therapeutic target for PCa.

KIF9-AS1 promotes nasopharyngeal carcinoma progression by suppressing miR-16

Long non-coding RNAs (lncRNAs) have been reported to serve a crucial role in the progression of nasopharyngeal carcinoma (NPC); however, the underlying molecular mechanisms of lncRNA KIF9-AS1 in the tumorigenesis of NPC remains poorly understood. Reverse transcription-quantitative PCR was used to analyze the expression levels of KIF9-AS1 and microRNA (miR)-16, and Cell Counting Kit-8, wound healing and Transwell assays were used to determine the cell viability, invasion and migration, respectively, of NPC cells. In addition, a dual-luciferase reporter assay was used to analyze the direct interaction between KIF9-AS1 and miR-16. NPC stage was classified according to the seventh edition of the AJCC staging system. The results revealed that KIF9-AS1 expression levels were upregulated in NPC tissues and cell lines. In addition, miR-16 was demonstrated to directly interact with KIF9-AS1 and inhibit KIF9-AS1 expression levels, whereas the miR-16 inhibitor rescued the effects of the KIF9-AS1-knockdown in NPC cells. Furthermore, the expression levels of KIF9-AS1 were upregulated, while those of miR-16 were downregulated in NPC tissues. Notably, the expression levels of KIF9-AS1 were observed to be significantly more upregulated in advanced tumors (III–IV vs. I–II) and patients with high KIF9-AS1 expression levels exhibited a worse prognosis. In conclusion, the findings of the present study suggested that KIF9-AS1 may promote the progression of NPC by targeting miR-16, thus KIF9-AS1 may be a novel molecular target for NPC therapy.

HNF1A-Induced lncRNA HCG18 Facilitates Gastric Cancer Progression by Upregulating DNAJB12 via miR-152-3p

Background

The aberrant expression of long non-coding RNAs (lncRNAs) plays a pivotal role in the development and progression of multiple cancers, including gastric cancer (GC). However, the underlying molecular mechanisms of lncRNA HCG18 in GC remain unknown.

Materials and Methods

The expression levels of HCG18, HNF1A, microRNA-152-3p (miR-152-3p), and DNAJB12 were determined by RT-qPCR. Cell viability, migration, and invasion were assessed by CCK-8, wound healing, and transwell assays, respectively. The interaction between miR-152-3p and HCG18 or DNAJB12 was predicted by bioinformatics analysis and verified by dual-luciferase reporter assay. The correlation between the gene expression levels was analyzed using Pearson’s correlation coefficient. Western blot was used to measure the levels of HNF1A, DNAJB12, epithelial-mesenchymal transition (EMT) proteins (E-cadherin and Vimentin), and proliferation-related protein (PCNA).

Results

It was found that HCG18 was upregulated in GC tissues and cell lines, and knockdown of HCG18 inhibited the proliferation, migration, and invasion of GC cells. Patients with high HCG18 expression had a shorter overall survival time compared with those with low HCG18 expression. In addition, transcription factor HNF1A could bind to the HCG18 promoter to facilitate its transcription. The upregulation of HCG18 could abolish the inhibitory effect of miR-152-3p overexpression on GC cell progression. Furthermore, DNAJB12 was demonstrated to be a target gene of miR-152-3p in GC cells, and HCG18 enhanced DNAJB12 expression by competitively binding with miR-152-3p. Finally, rescue assays proved that overexpression of DNAJB12 partially restored HCG18 knockdown-attenuated progression of GC cells.

Conclusion

Our results demonstrated that HNF1A-induced HCG18 overexpression promoted GC progression by competitively binding with miR-152-3p and upregulating DNAJB12 expression. These findings might provide potential treatment strategies for patients with GC.

lncRNA 00312 Attenuates Cell Proliferation and Invasion and Promotes Apoptosis in Renal Cell Carcinoma via miR-34a-5p/ASS1 Axis

Background

Previous studies have demonstrated that lncRNAs play functional roles in regulating cancer cell proliferation, invasion, and apoptosis. Recent studies confirmed that lncRNA 00312 has important biological functions in lung and colorectal cancer. However, the role of lncRNA 00312 in renal cell carcinoma (RCC) remains unclear. Our aim was to explore the function of lncRNA 00312 in RCC and its potential molecular mechanism.

Methods

RCC cell lines A498 and ACHN were used as in vitro models in this study. RT-PCR was performed to determine lncRNA 00312, miR-34a-5p, and ASS1 mRNA expression. Proliferation and invasion were examined by CCK-8 and Transwell assay to confirm the function role of lncRNA 00312. Western blot analysis was used to examine the expression of apoptotic proteins Bax and Bcl-2.

Results

lncRNA was significantly downregulated in RCC cells such as A498 and ACHN; the expression of lncRNA 00312 in RCC tissues was significantly lower than that in adjacent normal tissues. Patients with low expression of lncRNA 00312 have worse prognosis regarding pathological grade, tumor size, and TNM stage. Overexpression of lncRNA 00312 suppressed A498 and ACHN cell proliferation and invasion, while promoting apoptosis. Our study found that miR-34a-5p had the potential binding site with lncRNA 00312 and revealed the role of miR-34a-5p in RCC. Furthermore, we confirmed that lncRNA 00312 played its role with the participation of ASS1 and miR-34a-5p.

Conclusion

lncRNA 00312 can inhibit RCC proliferation and invasion and promote apoptosis in vitro by suppressing miR-34a-5p and overexpressing ASS1. Our study demonstrated that the lncRNA 00312/miR-34a-5p/ASS1 axis may play a functional role in the progression of RCC; lncRNA 00312 abundance is a prognostic factor candidate for RCC survival, which provides new insights for RCC clinical treatment.in vitro models in this study. RT-PCR was performed to determine lncRNA 00312, miR-34a-5p, and ASS1 mRNA expression. Proliferation and invasion were examined by CCK-8 and Transwell assay to confirm the function role of lncRNA 00312. Western blot analysis was used to examine the expression of apoptotic proteins Bax and Bcl-2.

BBOX1-AS1 contributes to colorectal cancer progression by sponging hsa-miR-361-3p and targeting SH2B1

Colorectal cancer (CRC) is the third main cause of cancer‐relevant deaths worldwide, and its incidence has increased in recent decades. Previous studies have indicated that certain long noncoding RNAs (lncRNAs) have regulatory roles in tumor occurrence and progression. Often, lncRNAs are competitive endogenous RNAs that sponge microRNAs to up‐regulate mRNAs. Here, we examined the role of a novel lncRNA gamma‐butyrobetaine hydroxylase 1 antisense RNA 1 (BBOX1‐AS1) in CRC. We observed that BBOX1‐AS1 is overexpressed in CRC cell lines, and BBOX1‐AS1 knockdown enhances cell proliferation, migration and invasion while reducing cell apoptosis. miR‐361‐3p is present at a low level in CRC and is negatively modified by BBOX1‐AS1. Moreover, miR‐361‐3p was validated to be targeted by BBOX1‐AS1. Src homology 2 B adaptor protein 1 (SH2B1) was notably upregulated in CRC cell lines and was identified as a downstream gene of miR‐361‐3p. In addition, we found that miR‐361‐3p amplification can suppress the expression of SH2B1. Finally, data from rescue assays suggested that overexpression of SH2B1 counteracted BBOX1‐AS1 silencing‐mediated inhibition of CRC progression. In conclusion, BBOX1‐AS1 promotes CRC progression by sponging hsa‐miR‐361‐3p and up‐regulating SH2B1.

Long noncoding RNA HULC accelerates the growth of human liver cancer stem cells by upregulating CyclinD1 through miR675-PKM2 pathway via autophagy

BACKGROUND

The functions of HULC have been demonstrated in several cancers. However, its mechanism has not been elucidated in human liver cancer stem cells.

METHODS

Liver cancer stem cells were isolated from Huh7 cells; gene infection and tumorigenesis test in vitro and in vivo were performed.

RESULTS

We demonstrate that HULC promotes growth of liver cancer stem cells in vitro and in vivo. Mechanistically, HULC enhances the expression of Sirt1 dependent on miR675 and then induces the cellular autophagy through Sirt1. HULC enhances CyclinD1 and thereby increases pRB and inhibited P21 WAF1/CIP 1 via autophagy-miR675-PKM2 pathway in human liver cancer stem cells. Ultimately, our results demonstrate that CyclinD1 is required for the oncogenic functions of HULC in liver cancer stem cells.

CONCLUSIONS

It reveals the key molecular signaling pathways for HULC and provides important basic information for finding effective tumor therapeutic targets based on HULC.

The novel lncRNA PTTG3P is downregulated and predicts poor prognosis in non-small cell lung cancer

INTRODUCTION

Lung cancer is the leading cause of cancer-associated mortality worldwide. Recently, long non-coding RNAs (lncRNAs) have been studied as key regulators in some biological processes. Of note, the molecular mechanism and prognostic value of lncRNAs in non-small cell lung cancer (NSCLC) have largely remained unclear.

MATERIAL AND METHODS

In this study, we compared the PTTG3P expression levels between lung cancer and normal lung samples by analyzing 5 public datasets (GSE18842, GSE19804, GSE27262, GSE30219, and GSE19188). Next, pentose phosphate pathway and co-expression networks were constructed to identify key targets of lncRNA PTTG3P. Furthermore, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to explore the potential roles of lncRNA PTTG3P. Moreover, we constructed PTTG3P-mediated ceRNA networks in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC).

RESULTS

In the present study, our analysis showed that PTTG3P expression was higher in high T stage LUAD and LUSC samples, as well as high N stage NSCLC tissues. Of note, we found that higher PTTG3P expression is correlated with shorter survival time in NSCLC patients by analyzing Kaplan-Meier plotter datasets. We found that PTTG3P was significantly associated with NSCLC cell proliferation regulation by affecting a series of cell cycle related biological processes.

CONCLUSIONS

Bioinformatics analysis showed that PTTG3P was associated with NSCLC cell proliferation. These results suggested that PTTG3P could serve as a new therapeutic and prognostic target for NSCLC.

Expression and Clinical Significance of Translation Regulatory Long Non-Coding RNA 1 (TRERNA1) in Ependymomas

Long noncoding RNAs (lncRNA) have emerged as vital molecules governing epithelial-to-mesenchymal transition (EMT) in cancers. Translation regulatory RNA 1 (TRERNA1) is one such lncRNA known to enhance the transcriptional activity of the EMT-transcription factor, Snail. We have previously demonstrated differential upregulation of EMT-transcription factors and cadherin switching across various clinico-pathologic-molecular subclasses of ependymomas (EPN). With an aim to analyze the correlation between the expression of TRERNA1 in EPNs, we performed gene expression analysis for TRERNA1 on 75 Grade II/III EPNs and correlated with tumor site, C11orf95-RELA fusions, age, MIB-1 proliferative indices, and outcome wherever available. Upregulation of gene expression levels of TRERNA1 was seen in intracranial EPNs, with highest expression levels in pediatric posterior fossa EPNs. High TRERNA1 expression was found associated with higher proliferative indices (p = 0.034) and shorter progression free survival (p = 0.002). Our study, for the first time, demonstrates an association between TRERNA1 expressions and pediatric posterior fossa EPNs. Further in-vivo and in-vitro studies are required to confirm these findings and evaluate TRERNA1 as a novel biomarker and potential therapeutic target in childhood PF-EPNs.

An eight-long non-coding RNA signature as a candidate prognostic biomarker for bladder cancer

Backgroud: Bladder cancer (BLCA) is one of the most fatal types of cancer worldwide. However, there are limited methods for us to provide a prognostic prediction of BLCA patients. Therefore, we aimed at developing a lncRNA signature to improve the prognosis prediction of BLCA.

RESULTS

An eight-lncRNA signature was significantly associated with recurrence free survival in BLCA patients from both discovery and validation groups. Furthermore, genes involved in the signature were enriched in extracellular matrix organization pathway. Finally, functional experiments demonstrated that six out of the eight lncRNAs significantly regulated the invasion of BLCA cells.

METHOD

A total of 343 BLCA patients from The Cancer Genome Atlas (TCGA) were employed and randomly divided into training (n=172) and validating (n=171) groups. The lncRNA expression profiles of BLCA patients were screened and a risk-score formula were created and validated according to the Cox regression analysis. Next, WGCNA method was employed to cluster genes that highly correlated with the risk scores based on the profiling data of TCGA dataset and transwell assay was also performed to further investigate the role of these lncRNAs.

CONCLUSIONS

Our results suggested that the eight-lncRNA signature was a candidate prognostic biomarker for predicting tumor recurrence of patients with BLCA.

Co-expression network analysis revealing the key lncRNAs in diabetic foot ulcers

INTRODUCTION

Diabetic foot ulcers (DFUs) are the most common foot injuries leading to lower extremity amputation in diabetic patients. Recent studies showed that long non-coding RNAs (lncRNAs) played important roles in diverse biological processes. In this study, we focused on identifying differentially expressed long non-coding RNAs (lncRNAs) in DFU.

MATERIAL AND METHODS

Real-time PCR assay was performed to validate the expression pattern of lncRNAs in DFU. Moreover, co-expression networks were also constructed to identify hub lncRNAs in DFU. Specifically, gene ontology (GO) analysis was first performed to evaluate the potential roles of differentially expressed genes (DEGs) and lncRNAs in DFU.

RESULTS

In the present study, we identified 58 up-regulated lncRNAs and 42 down-regulated lncRNAs in DFU samples compared to non-diabetic foot skin samples by analyzing the GSE68186 dataset. Four lncRNAs (FLJ30679, LINC01193, LINC00692, and LINC00641) were observed to be up-regulated in DFU. Furthermore, we found that the down-regulated lncRNA-mediated co-expression network contained 42 lncRNAs and 700 DEGs and the up-regulated lncRNA mediated co-expression network contained 58 lncRNAs and 688 DEGs.

CONCLUSIONS

Bioinformatics analysis showed that differentially expressed lncRNAs were involved in regulating the ERK1 and ERK2 cascade, secondary alcohol biosynthetic process, centrosome duplication and DNA repair. These results suggested the potential prognostic value of lncRNAs in DFU.

Long noncoding RNA GAS5 silencing inhibits the expression of KCNQ3 by sponging miR-135a-5p to prevent the progression of epilepsy

Epilepsy is one of the most common neurological disorders in humans. Recently, long noncoding RNAs (lncRNAs) have been reported to be important players in neurological diseases. Herein, this study aimed to examine the effect of lncRNA GAS5 on the occurrence of epilepsy in rat and cell models of epileptic seizure. The expression of lncRNA GAS5 was measured in the established rat and cell models. The binding sites between lncRNA GAS5 and miR-135a-5p, as well as those between miR-135a-5p and 3' untranslated region of KCNQ3 were predicted by miRDB and Targetscan, separately, followed by verification using dual-luciferase reporter gene assay. The expression of miR-135a-5p was measured in response to the overexpression of lncRNA GAS5. The mRNA and protein levels of KCNQ3 were examined in response to overexpression of miR-135a-5p. Next, the latency of epilepsy and frequency of epileptic seizures were assessed in rats injected with Lv-shGAS5 and Lv-miR-135a-5p in epileptic seizure model. In the rat and cell models, lncRNA GAS5 was highly expressed when epileptic seizure was induced. The expression of miR-135a-5p was decreased by overexpression of lncRNA GAS5. Meanwhile, the mRNA and protein levels of KCNQ3 were decreased in response to knockdown of miR-135a-5p. After the treatment of Lv-shGAS5 and Lv-miR-135a-5p, the average latent period of epilepsy was prolonged and the frequency of seizures was decreased. The key findings of the present study provide evidence emphasizing that lncRNA GAS5 functions as a competitive endogenous RNA of miR-135a-5p to increase expression of KCNQ3, and lncRNA GAS5 silencing inhibited the occurrence and progression of epilepsy.

Aberrant methylation-mediated downregulation of lncRNA SSTR5-AS1 promotes progression and metastasis of laryngeal squamous cell carcinoma

Background

Laryngeal squamous cell carcinoma (LSCC) is among the most common malignant tumors with poor prognosis. Accumulating evidences have identified the important roles of long noncoding RNAs (lncRNAs) in the initiation and progression of various cancer types; however, the global lncRNAs expression profile for metastatic LSCC is limited.

Results

In the present study, we screen expression profiles of lncRNAs in advanced LSCC patients with paired tumor tissues and corresponding normal tissues by microarrays. We identify numerous differentially expressed transcripts, and after the necessary verification of the transcripts expression in expanded samples, we experimentally validate the expression patterns of the remarkable low expressed gene, SSTR5, and its antisense lncRNA, SSTR5-AS1. Downregulation of SSTR5 is detected in LSCC tissues and laryngeal carcinoma cells. Aberrant DNA hypermethylation of the CpG sites clustered in the exon 1 and accumulation of inactive histone modifications at SSTR5 promoter region may be epigenetic mechanisms for its inactivation in LSCC. SSTR5-AS1 may play antitumor role in LSCC and may be regulated by the hypermethylation of the same CpG sites with SSTR5. SSTR5-AS1 inhibits laryngeal carcinoma cells proliferation, migration, and invasion. SSTR5-AS1 increases the enrichment of MLL3 and H3K4me3 at the promoter region of SSTR5 by interacting with MLL3 and further induces the transcription of SSTR5. Furthermore, SSTR5-AS1 interacts with and recruits TET1 to its target gene E-cadherin to activate its expression.

Conclusion

These findings suggest that the identified lncRNAs and mRNAs may be potential biomarkers in metastatic LSCC, and SSTR5-AS1 may act as a tumor suppressor as well as a potential biomarker for antitumor therapy.

Electronic supplementary material

The online version of this article (10.1186/s13072-019-0283-8) contains supplementary material, which is available to authorized users.

RRBP1 is highly expressed in prostate cancer and correlates with prognosis

Objective: Recently, ribosome binding protein 1 (RRBP1) is reported to be involved in tumorigenesis. However, the expression and clinical significance of RRBP1 in prostate cancer (PCa) remains unknown. This study is aimed to investigate the expression and clinical significance of RRBP1 in PCa.

Materials and methods: RRBP1 expression was firstly detected in 6 cases of PCa and matched adjacent non-cancerous prostate tissues by reverse transcription-quantitative PCR (RT-qPCR) and Western blot. Then, RRBP1 expression was further detected in 127 cases of PCa and 40 cases of non-cancerous prostate tissues by immunohistochemistry (IHC). The relationship of RRBP1 with clinical-pathological characters and patients’ prognosis was analyzed in PCa.

Results: RT-qPCR and Western blot analysis showed that RRBP1 expression levels in PCa tissues were significantly higher compared with those in matched adjacent non-cancerous prostate tissues. IHC results shown that the high-expression rate of RRBP1 in PCa was 69.3%, which was significantly greater than those in non-cancerous prostate tissues (15.0%, P<0.001). RRBP1 expression was significantly associated with T stage, lymph node metastasis, PSA and Gleason score in PCa. Survival analysis indicated that patients with RRBP1 low-expression presented longer survival time compared with those with RRBP1 high-expression. Moreover, RRBP1 as well as T stage, lymph node metastasis and Gleason score could serve as independent prognostic factors in PCa.

Conclusion: RRBP1 is highly expressed in PCa and correlates with prognosis, which may serve as a potential biomarker in PCa.

Keratin 6A gene silencing suppresses cell invasion and metastasis of nasopharyngeal carcinoma via the β‑catenin cascade

Nasopharyngeal carcinoma (NPC) is a type of head and neck cancer. This study aimed to study the mechanisms of ectopic keratin 6A (KRT6A) in NPC. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were performed to detect KRT6A levels in NPC cell lines (C666-1, 5-8F and SUNE-1) and a nasopharyngeal epithelial cell line (NP69, as a control). After SUNE-1 NPC cells had been silenced by KRT6A, cell viability, metastasis and invasion were determined using Cell Counting Kit-8, wound healing and Transwell assays, respectively. KRT6A levels, metastasis-associated factors and the Wnt/β-catenin pathway were measured using RT-qPCR and western blotting. It was demonstrated that KRT6A was upregulated in all detected NPC cells, among which KRT6A was the highest in SUNE-1 cells. In SUNE-1 cells, cell viability was inhibited at 24 and 48 h, and that cell metastasis and invasion were demonstrated to be suppressed by KRT6A silencing. Both the mRNA and protein levels of KRT6A, matrix metalloproteinase (MMP)-2, MMP-9, β-catenin, lymphoid enhancer binding factor 1 and T-cell specific factor 4 were reduced in the small interfering (si)KRT6A group. However, the results demonstrated that the levels of epithelial-cadherin and tissue inhibitor of metalloproteinase-2 (TIMP-2) were promoted in the siKRT6A group. The activation of the Wnt/β-catenin pathway by lithium chloride reversed the effect of si-KRT6A by modulating the expression of MMP-2/9 and TIMP2. It was observed that KRT6A silencing suppressed cell invasion and metastasis of NPC via the β-catenin cascade. Together these results provide important insights into a novel approach for the diagnosis and treatment of NPC.

Long Non-coding RNA CDKN2B Antisense RNA 1 Gene Contributes to Paclitaxel Resistance in Endometrial Carcinoma

Endometrial cancer (EC) is the most common malignancy of the female reproductive tract. In this study, we clarified the clinical significance of CDKN2B antisense RNA 1 (CDKN2B-AS) gene, and its effects on paclitaxel sensitivity in EC. Firstly, CDKN2B-AS gene was highly expressed in EC tissues and cell lines. The high-expression of CDKN2B-AS gene was associated with high pathological grade and low paclitaxel sensitivity of EC tissues. Knockdown of CDKN2B-AS gene sensitized Ishikawa/PA and HEC1A/PA cells to paclitaxel, and promoted paclitaxel-induced cytotoxicity. Secondly, the low-expression of miR-125a-5p was closely associated with low paclitaxel sensitivity of EC cells, and up-regulation of miR-125a-5p could increase paclitaxel sensitivity of Ishikawa/PA and HEC1A/PA cells. MiR-125a-5p also mediated the suppressive effects of knockdown of CDKN2B-AS on paclitaxel resistance in EC cells. Thirdly, B-cell lymphoma-2 (Bcl2) and Multidrug Resistance-Associated Protein 4 (MRP4) genes were target genes of miR-125a-5p, which modulated paclitaxel resistance of Ishikawa/PA and HEC1A/PA cells through targeted silencing Bcl2 and MRP4. In conclusion, high-expression of CDKN2B-AS is associated with a poor response to paclitaxel of EC patients, and knockdown of CDKN2B-AS inhibits paclitaxel resistance through miR-125a-5p-Bcl2/MRP4 pathway in EC patients. Our findings help elucidate the molecular mechanisms of chemoresistance in EC patients.

Involvement of long non-coding RNA HULC (highly up-regulated in liver cancer) in pathogenesis and implications for therapeutic intervention

INTRODUCTION

HULC (highly upregulated in liver cancer) is a long non-coding RNA (lncRNA) which is, as its name suggests, highly upregulated in hepatocellular carcinoma and in several other cancers. Increased HULC expression levels are strongly associated with clinicopathologic features such as tumor stages and overall survival and is a driver of tumor proliferation, migration, and invasion. Areas covered: This review addresses the discovery of HULC and discusses the consequences of HULC deregulation in cancer, the underlying molecular mechanisms and the potential of HULC as a biomarker and therapeutic target. Expert opinion: HULC is a promising candidate as a therapeutic target in cancer; however, more studies are necessary to further elucidate the underlying molecular mechanism(s), especially in cancer types other than hepatocellular carcinomas. Future studies that focus on an optimized HULC-targeting approach are necessary to clarify the best strategy to target this lncRNA in vivo and in patients.

lncRNA PCAT6 promotes non-small cell lung cancer cell proliferation, migration and invasion through regulating miR-330-5p

Background

Investigating the roles of lncRNA prostate cancer-associated transcript 6 (PCAT6) in modulating the growth and aggressiveness of non-small-cell lung carcinoma (NSCLC) cell.

Method

The levels of PCAT6 in NSCLC tissues and cell lines were determined by quantitative real-time PCR assay. MTT as well as colony formation assays were applied to explore the effect of PCAT6 on the growth of NSCLC cell in vitro. Wound healing and Transwell assays were utilized to analyze the impact of PCAT6 on the migration and invasion of NSCLC cell. Bioinformatics analysis and luciferase reporter assay were used to prove that miR-330-5p was the target of PCAT6. Colony formation, wound healing, and Transwell invasion assays were applied to demonstrate that PCAT6 promoted NSCLC cell growth, migration, and invasion through binding miR-330-5p. Finally, xenograft model was used to explore the role of PCAT6 in the tumor growth of NSCLC cell in vivo.

Results

PCAT6 was highly overexpressed in NSCLC tissues and cells compared with normal tissues and non-tumorigenic bronchial epithelial cell line, BEAS-2B. Downregulation of PCAT6 markedly reduced the proliferation, migration, and invasion of NSCLC cell. Moreover, down-expression of PCAT6 significantly increased the level of miR-330-5p in NSCLC cell. Further functional experiments indicated that down-expression of miR-330-5p reversed the inhibitory effect of PCAT6 on NSCLC cell growth, migration, and invasion.

Conclusion

Our results reveal that lncRNA PCAT6 facilitates the proliferation, migration, and invasion of NSCLC cell via competitively binding to miR-330-5p.