LncRNA HIF1A-AS2 positively affects the progression and EMT formation of colorectal cancer through regulating miR-129-5p and DNMT3A

Circ_0005785 Silencing Constrains the Functional Properties of Colorectal Cancer Cells Depending on miR-7-5p/DNMT3A Axis

Circular RNAs (circRNAs) closely related to the progression of colorectal cancer (CRC). Nevertheless, the study of circ_0005785 in CRC has not been reported. In this test, we aimed to investigate the mechanisms of circ_0005785 in CRC development. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were employed to reveal the expression of genes and proteins. Cell Counting Kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry analysis, transwell assay and tube formation experiment were implemented to examine cell growth, apoptosis, invasion and angiogenesis. The relationships among circ_0005785, miR-7-5p and DNA methyltransferase 3 A (DNMT3A) were verified by dual-luciferase reporter assay. Xenograft mouse model was built to evaluate the impacts of circ_0005785 deficiency on CRC growth in vivo. We found that circ_0005785 was increased in CRC patients and cell lines. Circ_0005785 downregulation retarded cell proliferation, invasion, angiogenesis whereas expedited apoptosis in CRC cells. Mechanistically, circ_0005785 could sponge miR-7-5p and the suppressive treads of circ_0005785 in CRC development was attenuated by miR-7-5p down-regulation. DNMT3A was targeted by miR-7-5p and miR-7-5p overexpression constrained cell malignant behaviors, but the addition of DNMT3A counteracted the effects. Additionally, circ_0005785 inhibition hindered the tumor growth in vivo. In conclusion, circ_0005785 aggravated the CRC progression by increasing the level of DNMT3A via adsorbing miR-7-5p.

LncRNA RPLP0P2 Promotes Colorectal Cancer Proliferation and Invasion via the miR-129-5p/Zinc Finger and BTB Domain-Containing 20 Axis

We previously reported that long non-coding RNA (lncRNA) RPLP0P2 is involved in the progression of colorectal cancer (CRC); however, its molecular mechanisms in CRC remain unclear. In this study, we observed that RPLP0P2 was upregulated in CRC tissues and cell lines. Cell viability was measured using the MTT and colony formation assays. Migration and invasion capabilities were monitored by wound healing, transwell, and immunofluorescence assays. The results showed that RPLP0P2 downregulation inhibited cell viability, migration, and invasion capabilities of CRC cells, accompanied by decreased PCNA, N-cadherin, and Vimentin, and increased E-cadherin expression. Using the DIANA online database, miR-129-5p was identified as a downstream target of RPLP0P2. In fact, RPLP0P2 colocalized with miR-129-5p, acting as a miR-129-5p sponge. MiR-129-5p-inhibition almost abrogated the anti-tumor effects induced by RPLP0P2 inhibition in CRC cells. Zinc finger and BTB domain-containing 20 (ZBTB20) was identified as a potential downstream target of miR-129-5p in CRC cells. ZBTB20 overexpression prevented miR-129-5p mimic-mediated anti-tumor effects in CRC cells. A tumor xenograft assay was performed to monitor the role of RPLP0P2 in tumor growth. Of note, in tumor-bearing mice, RPLP0P2-silencing inhibited tumor growth, followed by increased miR-129-5p and decreased ZBTB20 expression. Our results suggest that lncRNA RPLP0P2 functions as an oncogene that promotes CRC cell proliferation and invasion via regulating the miR-129-5p/ZBTB20 axis, thus, it may serve as a candidate target for CRC interventional therapies.

From molecular pathogenesis to therapy: Unraveling non-coding RNAs/DNMT3A axis in human cancers

Cancer is a comprehensive classification encompassing more than 100 forms of malignancies that manifest in diverse tissues within the human body. Recent studies have provided evidence that aberrant epigenetic modifications are pivotal indicators of cancer. Epigenetics encapsulates DNA methyltransferases as a crucial class of modifiers. DNMTs, including DNMT3A, assume central roles in DNA methylation processes that orchestrate normal biological functions, such as gene transcription, predominantly in mammals. Typically, deviations in DNMT3A function engender distortions in factors that drive tumor growth and progression, thereby exacerbating the malignant phenotype of tumors. Consequently, such abnormalities pose significant challenges in cancer therapy because they impede treatment efficacy. Non-coding RNAs (ncRNAs) represent a group of RNA molecules that cannot encode functional proteins. Recent investigation attests to the crucial significance of regulatory ncRNAs in epigenetic regulation. Notably, recent reports have illuminated the complex interplay between ncRNA expression and epigenetic regulatory machinery, including DNMT3A, particularly in cancer. Recent findings have demonstrated that miRNAs, namely miR-770-5p, miR-101, and miR-145 exhibit the capability to target DNMT3A directly, and their aberration is implicated in diverse cellular abnormalities that predispose to cancer development. This review aims to articulate the interplay between DNMT3A and the ncRNAs, focusing on its impact on the development and progression of cancer, cancer therapy resistance, cancer stem cells, and prognosis. Importantly, the emergence of such reports that suggest a connection between DNMT3A and ncRNAs in several cancers indicates that this connecting axis offers a valuable target with significant therapeutic potential that might be exploited for cancer management.

Long non-coding RNA HIF1A-AS2 promotes carcinogenesis by enhancing Gli1-mediated HIF1α expression in clear cell renal cell carcinoma

BACKGROUND

The most common urologic tumor in humans with the highest incidence rate is clear cell renal cell carcinoma (ccRCC). Long non-coding RNAs (lncRNAs) act as regulatory factors in several tumors. Here, we studied ccRCC regulated by hypoxia-inducible factor 1α (HIF1α)-antisense RNA 2 (AS2) or HIF1A-AS2.

METHODS

We performed wound-healing, transwell, and CCK-8 assays by decreasing or increasing the HIF1A-AS2 expression in RCC cell lines. Western blotting and qRT-PCR were used to identify the expression of downstream genes of the HIF1A-AS2 pathway. Gli1 and HIF1A-AS2 relationship was assessed using RIP and RNA pull-down assays. Lastly, transcriptome sequencing was performed on kidney cancer cells that had been knocked down to find possible regulatory mechanisms.

RESULTS

Our results suggest that high expression of HIF1A-AS2 may promote RCC cell proliferation and Gli1 expression as a downstream factor. Furthermore, they have physical binding sites and together regulate HIF1α to encourage the development of ccRCC. HIF1A-AS2 lncRNA may offer a new molecular target for ccRCC treatment.

CONCLUSION

lncRNA HIF1A-AS2 affects ccRCC development by regulating HIF1a expression through Gli1.

Roles of lncRNA in the diagnosis and prognosis of triple-negative breast cancer

Breast cancer is a malignant tumor that seriously endangers women's lives. The prognosis of breast cancer patients differs among molecular types. Compared with other subtypes, triple-negative breast cancer (TNBC) has been a research hotspot in recent years because of its high degree of malignancy, strong invasiveness, rapid progression, easy of recurrence, distant metastasis, poor prognosis, and high mortality. Many studies have found that long non-coding RNA (lncRNA) plays an important role in the occurrence, proliferation, migration, recurrence, chemotherapy resistance, and other characteristics of TNBC. Some lncRNAs are expected to become biomarkers in the diagnosis and prognosis of TNBC, and even new targets for its treatment. Based on a PubMed literature search, this review summarizes the progress in research on lncRNAs in TNBC and discusses their roles in TNBC diagnosis, prognosis, and chemotherapy with the hope of providing help for future research.

A lncRNA-disease association prediction model based on the two-step PU learning and fully connected neural networks

Long non-coding RNAs (lncRNAs) have been shown to play a regulatory role in various processes of human diseases. However, lncRNA experiments are inefficient, time-consuming and highly subjective, so that the number of experimentally verified associations between lncRNA and diseases is limited. In the era of big data, numerous machine learning methods have been proposed to predict the potential association between lncRNA and diseases, but the characteristics of the associated data were seldom explored. In these methods, negative samples are randomly selected for model training and the model is prone to learn the potential positive association error, thus affecting the prediction accuracy. In this paper, we proposed a cyclic optimization model of predicting lncRNA-disease associations (COPTLDA in short). In COPTLDA, the two-step training strategy is adopted to search for the samples with the greater probability of being negative examples from unlabeled samples and the determined samples are treated as negative samples, which are combined together with known positive samples to train the model. The searching and training steps are repeated until the best model is obtained as the final prediction model. In order to evaluate the performance of the model, 30% of the known positive samples are used to calculate the model accuracy and 10% of positive samples are used to calculate the recall rate of the model. The sampling strategy used in this paper can improve the accuracy and the AUC value reaches 0.9348. The results of case studies showed that the model could predict the potential associations between lncRNA and malignant tumors such as colorectal cancer, gastric cancer, and breast cancer. The predicted top 20 associated lncRNAs included 10 colorectal cancer lncRNAs, 2 gastric cancer lncRNAs, and 8 breast cancer lncRNAs.

Colon cancer transcriptome

Over the last four decades, methodological innovations have continuously changed transcriptome profiling. It is now feasible to sequence and quantify the transcriptional outputs of individual cells or thousands of samples using RNA sequencing (RNA-seq). These transcriptomes serve as a connection between cellular behaviors and their underlying molecular mechanisms, such as mutations. This relationship, in the context of cancer, provides a chance to unravel tumor complexity and heterogeneity and uncover novel biomarkers or treatment options. Since colon cancer is one of the most frequent malignancies, its prognosis and diagnosis seem to be critical. The transcriptome technology is developing for an earlier and more accurate diagnosis of cancer which can provide better protectivity and prognostic utility to medical teams and patients. A transcriptome is a whole set of expressed coding and non-coding RNAs in an individual or cell population. The cancer transcriptome includes RNA-based changes. The combined genome and transcriptome of a patient may provide a comprehensive picture of their cancer, and this information is beginning to affect treatment decision-making in real-time. A full assessment of the transcriptome of colon (colorectal) cancer has been assessed in this review paper based on risk factors such as age, obesity, gender, alcohol use, race, and also different stages of cancer, as well as non-coding RNAs like circRNAs, miRNAs, lncRNAs, and siRNAs. Similarly, they have been examined independently in the transcriptome study of colon cancer.

Long non-coding RNA HIF1A-As2 and MYC form a double-positive feedback loop to promote cell proliferation and metastasis in KRAS-driven non-small cell lung cancer

Lung cancer is the leading cause of cancer-related deaths worldwide. KRAS is the main oncogenic driver in lung cancer that can be activated by gene mutation or amplification, but whether long non-coding RNAs (lncRNAs) regulate its activation remains unknown. Through gain and loss of function approaches, we identified that lncRNA HIF1A-As2, a KRAS-induced lncRNA, is required for cell proliferation, epithelial-mesenchymal transition (EMT) and tumor propagation in non-small cell lung cancer (NSCLC) in vitro and in vivo. Integrative analysis of HIF1A-As2 transcriptomic profiling reveals that HIF1A-As2 modulates gene expression in trans, particularly regulating transcriptional factor genes including MYC. Mechanistically, HIF1A-As2 epigenetically activates MYC by recruiting DHX9 on MYC promoter, consequently stimulating the transcription of MYC and its target genes. In addition, KRAS promotes HIF1A-As2 expression via the induction of MYC, suggesting HIF1A-As2 and MYC form a double-regulatory loop to strengthen cell proliferation and tumor metastasis in lung cancer. Inhibition of HIF1A-As2 by LNA GapmeR antisense oligonucleotides (ASO) significantly improves sensitization to 10058-F4 (a MYC-specific inhibitor) and cisplatin treatment in PDX and KRAS^LSLG12D-driven lung tumors, respectively.

The Cell Cycle-Associated Protein CDKN2A May Promotes Colorectal Cancer Cell Metastasis by Inducing Epithelial-Mesenchymal Transition

Colorectal cancer (CRC) is a common gastrointestinal malignancy, and recurrence and metastasis contribute considerably to its high mortality. It is well known that the epithelial-mesenchymal transition (EMT) accelerates the rate of cancer cell dissemination and migration, thus promoting cancer metastasis. Targeted therapy is a common modality for cancer treatment, and it can play a role in inhibiting cancer progression. In this study, bioinformatics was used to search for genes associated with the prognosis of CRC. First, differential analysis was performed on colon and rectal cancer samples to obtain 2,840 and 3,177 differentially expressed genes (DEGs), respectively. A Venn diagram was then used to identify 262 overlapping genes from the two groups of DEGs and EMT-related genes. The overlapping genes were subjected to batch survival analysis and batch expression analysis successively, and nine genes were obtained whose high expression in CRC led to a poor prognosis. The least absolute shrinkage and selection operator (LASSO) prognostic model was then constructed to obtain the risk score formula. A nomogram was constructed to seek prognostic independent factors to obtain CDKN2A. Finally, CCK-8 assay, flow cytometry and western blotting assays were performed to analyze the cellular biological function of CDKN2A. The results showed that knockdown of CDKN2A expression inhibited HT-29 cell proliferation, promoted apoptosis and cell cycle progression, and affected the EMT process in CRC.

SPATS2 is positively activated by long noncoding RNA SNHG5 via regulating DNMT3a expression to promote hepatocellular carcinoma progression

Hepatocellular carcinoma (HCC) is one of the most prevalent malignant tumors with high mortality worldwide. Spermatogenesis-associated serine-rich 2 (SPATS2) could be a novel diagnostic and prognostic biomarker in HCC. However, the regulatory mechanism of SPATS2 in HCC requires further elucidation. Therefore, the study’s objective was to investigate this process in HCC. In this study, we found that SPATS2 is significantly upregulated in HepG2 cells to promote cell growth and migration. SPATS2 is the target transcript of lncRNA SNHG5. SPATS2 positively affects the proliferation and migration of HepG2 cells caused by the higher expression of SNHG5. Mechanistically, we identified that the elevated of SPATS2 was attributed to SNHG5 related hypomethylation of SPATS2. SNHG5 reduced the expression of DNMT3a to suppress the methylation level of SPATS2. Taken together, our results uncover a novel epigenetic regulatory mechanism of lncRNA SNHG5-DNMT3a axis-related SPATS2 expression underlying HCC progression. This may serve as a novel prognostic marker and a promising therapeutic target for the treatment of HCC.

Regulation of epithelial-to-mesenchymal transition in hypoxia by the HIF-1α network

Epithelial-to-mesenchymal transition (EMT) plays a significant role in cancer metastasis. A series of models have focused on EMT regulation by TGF-β network. However, how EMT is regulated under hypoxia is less understood. We developed a model of HIF-1α network to explore the potential link between EMT and the network topology. Our results revealed that three positive feedback loops, composed of HIF-1α and its three targets SNAIL, TWIST, and miR-210, should be sequentially activated to induce EMT under aggravating hypoxia. We suggested that the number of the positive feedback loops is critical for determining the number of stable states in EMT. Our work may advance the understanding of the significance of network topology in the regulation of EMT.

Exosomal-long non-coding RNAs journey in colorectal cancer: Evil and goodness faces of key players

Exosomes are nano-vesicles (NVs) secreted by cells and take part in cell-cell communications. Lately, these exosomes were proved to have dual faces in cancer. Actually, they can contribute to carcinogenesis through epithelial-mesenchymal transition (EMT), angiogenesis, metastasis and tumor microenvironment (TME) of various cancers, including colorectal cancer (CRC). On the other hand, they can be potential targets for cancer treatment. CRC is one of the most frequent tumors worldwide, with incidence rates rising in the recent decades. In its early stage, CRC is asymptomatic with poor treatment outcomes. Therefore, finding a non-invasive, early diagnostic biomarker tool and/or suitable defender to combat CRC is mandatory. Exosomes provide enrichment and safe setting for their cargos non-coding RNAs (ncRNAs) and proteins, whose expression levels can be upregulated ordown-regulated in cancer. Hence, exosomes can be used as diagnostic and/or prognostic tools for cancer. Moreover, exosomes can provide a novel potential therapeutic modality for tumors via loading with specific chemotherapeutic agents, with the advantage of possible tumor targeting. In this review, we will try to collect and address recent studies concerned with exosomes and their cargos' implications for CRC diagnosis and/or hopefully, treatment.

Breviscapine Participates in the Progression of Prostate Cancer by Inhibiting ZFP91 Expression through Upregulation of MicroRNA-129-5p

Objective

To investigate the effect of breviscapine (BVP) on the development of prostate cancer and its molecular mechanism.

Materials and Methods

After treatment with breviscapine and microRNA-129-5p, MTT (3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide) and cell counting kit-8 (CCK-8) tests were performed to examine the proliferation rate of cells, while Transwell was used to analyze cell migration ability; at the same time, quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect the expression of microRNA-129-5p and ZFP91 in prostate cancer cells. In addition, the binding of microRNA-129-5p and ZFP91 was confirmed by dual-luciferase reporting assay; meanwhile, cell reverse experiment verified that breviscapine can regulate ZFP91 via upregulating microRNA-129-5p.

Results

The results of MTT, CCK-8, and Transwell experiments demonstrated that breviscapine inhibited the proliferation as well as the migration capacities of PC cells; meanwhile, it upregulated the level of microRNA-129-5p in PC cells while downregulated that of ZFP91. Furthermore, dual-luciferase reporter gene assay verified that ZFP91 was a potential target of microRNA-129-5p. Finally, cell reverse experiment confirmed that breviscapine downregulated ZFP91 expression by upregulating microRNA-129-5p, while downregulation of microRNA-129-5p partially reversed the inhibitory effect of breviscapine on cell proliferation ability.

Conclusions

Breviscapine may inhibit the expression of ZFP91 through upregulating microRNA-129-5p and thus participating in the progression of PC.

FAM83H-AS1/miR-485-5p/MEF2D axis facilitates proliferation, migration and invasion of hepatocellular carcinoma cells

Background

Abundant evidence has manifested that long noncoding RNAs (lncRNAs) are closely implicated in human cancers, including hepatocellular carcinoma (HCC). Remarkably, lncRNA FAM83H antisense RNA 1 (FAM83H-AS1) has been reported to be a tumor-propeller in multiple cancers. However, its effect on HCC progression remains unknown.

Methods

FAM83H-AS1 expression was analyzed by RT-qPCR. Colony formation, EdU, and flow cytometry as well as transwell assays were implemented to analyze the biological functions of FAM83H-AS1 on HCC progression. Luciferase reporter, RIP and RNA pull-down assays were implemented to detect the interaction among FAM83H-AS1, microRNA-485-5p (miR-485-5p), and myocyte enhancer factor 2D (MEF2D) in HCC cells.

Results

FAM83H-AS1 expression in HCC cells was markedly elevated. FAM83H-AS1 accelerated cell proliferation, migration and invasion whereas inhibiting cell apoptosis in HCC. Besides, we confirmed that FAM83H-AS1 acts as a miR-485-5p sponge in HCC cells. Additionally, MEF2D was verified to be a direct target of miR-485-5p. FAM83H-AS1 could upregulate MEF2D expression via sponging miR-485-5p. Further, rescue experiments testified that MEF2D upregulation or miR-485-5p downregulation offset the repressive effect of FAM83H-AS1 depletion on HCC cell progression.

Conclusions

FAM83H-AS1 facilitates HCC malignant progression via targeting miR-485-5p/MEF2D axis, suggesting that FAM83H-AS1 may be a promising biomarker for HCC treatment in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08923-0.

HIF1A-AS2 induces osimertinib resistance in lung adenocarcinoma patients by regulating the miR-146b-5p/IL-6/STAT3 axis

Although epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) show efficacy in lung adenocarcinoma (LUAD) patients, TKI resistance inevitably develops, limiting long-term results. Thus, there is an urgent need to address drug resistance in LUAD. Long non-coding RNA (lncRNA) HIF1A-AS2 could be a critical mediator in the progression of various tumor types. We examined the function of HIF1A-AS2 in modifying tumor aggravation and osimertinib resistance in lung adenocarcinoma. Using clinical samples, we showed that HIF1A-AS2 was upregulated in LUAD specimens, predicting poorer overall survival and disease-free survival. HIF1A-AS2 silencing inhibited the proliferation, migration, and tumorigenesis of LUAD cells and therapeutic efficacy of osimertinib against tumor cells in vitro and in vivo. RNA precipitation assays, western blotting, luciferase assays, and rescue experiments demonstrated that HIF1A-AS2 sponged microRNA-146b-5p (miR-146b-5p), promoting interleukin-6 (IL-6) expression, activating the IL-6/STAT3 pathway, and leading to LUAD progression. miR-146b-5p and IL-6 levels were correlated with the prognosis of LUAD patients. Our results indicated that HIF1A-AS2 functions as an oncogenic factor in adenocarcinoma cells by targeting the miR-146b-5p/IL-6/STAT3 axis and may be a prognostic indicator of survival. Moreover, it can be a potential therapeutic target to enhance the efficacy of osimertinib in LUAD patients.

HIF1A-AS2 Promotes the Proliferation and Metastasis of Gastric Cancer Cells Through miR-429/PD-L1 Axis

BACKGROUND

Gastric cancer (GC) is a common leading cause of cancer-related mortality of all malignancies. LncRNA hypoxia-inducible factor-1 alpha antisense RNA-2 (HIF1A-AS2) has been identified to involve in the development of GC. Therefore, we further explored the detailed molecular mechanism of HIF1A-AS2 in GC progression.

METHODS

The expression of HIF1A-AS2, microRNA-429 (miR-429), and programmed cell death ligand 1 (PD-L1) was measured using quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Cell proliferation, migration, and invasion abilities were detected by Cell Counting Kit-8 (CCK-8) or transwell assay. The interaction between miR-429 and HIF1A-AS2 or PD-L1 was confirmed by luciferase reporter assay. Murine xenograft model was established to investigate the role of HIF1A-AS2 in vivo.

RESULTS

HIF1A-AS2 was elevated in GC tissues and cell lines. Functional experiments showed that HIF1A-AS2 knockdown inhibited GC cell proliferation, migration, and invasion in vitro, as well as hindered tumor growth in vivo. Moreover, HIF1A-AS2 directly bound to miR-429 based on bioinformatics prediction and luciferase assay, and inhibition of miR-429 abolished the effects of HIF1A-AS2 knockdown on GC cells. Furthermore, miR-429 directly targeted PD-L1, and overexpression of miR-429 suppressed GC tumorigenesis via PD-L1. Besides that, PD-L1 also performed an oncogenic role in GC cell proliferation and metastasis. Additionally, HIF1A-AS2 could indirectly regulate PD-L1 expression via sponging miR-429.

CONCLUSION

HIF1A-AS2 is a dependable predictor of malignancy and prognosis in GC and functions as an oncogene to promote GC cell proliferation and metastasis by regulating miR-429/PD-L1 axis, indicating a new insight into the search for novel biomarkers and therapeutic strategies.

circ-SIRT1 Promotes Colorectal Cancer Proliferation and EMT by Recruiting and Binding to eIF4A3

Circular RNA (circRNA), a recently identified type of endogenous noncoding RNA, has been implicated in the occurrence and development of a variety of tumors; however, whether circ-SIRT1, derived from pre-mRNA of the parental SIRT1 gene, is involved in colorectal cancer (CRC) remains unknown, as do the potential underlying mechanisms. The expression of circ-SIRT1 in CRC cells and tissue was detected by RT-qPCR. Colony formation and Cell Counting Kit-8 assays were used to evaluate the effect of circ-SIRT1 knockdown on the proliferative ability of CRC cells. Wound healing and Transwell assays were used to assess the effect of circ-SIRT1 knockdown on the migratory and invasive capacity of CRC cells. RNA immunoprecipitation and RNA pull-down assays were employed to validate the binding of circ-SIRT1 to EIF4A3. Western blot was used to identify the changes in the expression of EIF4A3 and EMT-related proteins. The RT-qPCR results showed that circ-SIRT1 was highly expressed in CRC cells and tissue and was positively correlated with the depth of tumor invasion. Knocking down circ-SIRT1 inhibited the proliferation and invasion of CRC cells and EMT. We further found that EIF4A3 could bind to circ-SIRT1, and that overexpressing circ-SIRT1 decreased the abundance of EIF4A3 at the mRNAs of the EMT marker proteins N-cadherin and vimentin. Combined, our findings suggested that circ-SIRT1 regulates the expression of EMT-related proteins by preventing EIF4A3 recruitment to the respective mRNAs. Our results further indicate that circ-SIRT1 functions as an oncogene in CRC by promoting the proliferation, invasion, and EMT of CRC cells through the circ-SIRT1/EIF4A3/N-cadherin/vimentin pathway.

Expression and Functional Analysis of lncRNAs Involved in Platelet-Derived Growth Factor-BB-Induced Proliferation of Human Aortic Smooth Muscle Cells

Abnormal proliferation of vascular smooth muscle cells (VSMCs) is a common feature of many vascular remodeling diseases. Because long non-coding RNAs (lncRNAs) play a critical role in cardiovascular diseases, we analyzed the key lncRNAs that regulate VSMC proliferation. Microarray analysis identified 2,643 differentially expressed lncRNAs (DELs) and 3,720 differentially expressed coding genes (DEGs) between fetal bovine serum (FBS) starvation-induced quiescent human aortic smooth muscle cells (HASMCs) and platelet-derived growth factor-BB (PDGF-BB)-stimulated proliferative HASMCs. Gene Ontology and pathway analyses of the identified DEGs and DELs demonstrated that many lncRNAs were enriched in pathways related to cell proliferation. One of the upregulated lncRNAs in proliferative HASMC was HIF1A anti-sense RNA 2 (HIF1A-AS2). HIF1A-AS2 suppression decreased HASMC proliferation via the miR-30e-5p/CCND2 mRNA axis. We have thus identified key DELs and DEGs involved in the regulation of PDGF-BB induced HASMC proliferation. Moreover, HIF1A-AS2 promotes HASMC proliferation, suggesting its potential involvement in VSMC proliferative vascular diseases.

lncRNA HIF1A-AS2: A potential oncogene in human cancers (Review)

Long non-coding RNAs (lncRNAs) are transcripts that are >200 nucleotides, but with no open reading frame. An increasing number of lncRNAs have been identified following the development of second-generation sequencing technologies, and they have since become a research hotspot. Functionally, they play a vital role in tumor progression, including in tumor proliferation, migration, invasion, apoptosis and acquisition of drug resistance. They regulate gene expression primarily through interaction with DNA, RNA and proteins at the epigenetic, transcriptional and post-transcriptional levels. Endogenous hypoxia-inducible factor 1α antisense RNA 2 (lncRNA HIF1A-AS2) is aberrantly expressed and involved the development/progression of various types of tumors, such as bladder cancer, glioblastoma, breast cancer and osteosarcoma. It plays a vital role in the proliferation, apoptosis, migration, invasion and epithelial-mesenchymal transformation of various tumor cells. This review summarizes the current body of knowledge on the biological functions and related molecular mechanisms of lncRNA HIF1A-AS2 in the development/progression of human tumors and other diseases.

Knockdown of lncRNA HIF1A-AS2 increases drug sensitivity of SCLC cells in association with autophagy

The aim of this study was to determine the effect of lncRNA HIF1A-AS2 on autophagy-associated drug resistance in small cell lung cancer (SCLC) cells. The expression of HIF1A-AS2 was silenced by siRNA in doxorubicin-sensitive H69 and doxorubicin-resistant H69AR cells. Then, cytotoxicity, apoptosis and autophagy analyses were carried out in the normoxic and CoCl₂-induced hypoxic environment. The effect of HIF1A-AS2 on the expression levels of genes, which are associated with drug resistance and autophagy, was determinated by qRT-PCR analysis. The levels of MRP1, HIF-1α and Beclin-1 were analyzed by western blot method. Knockdown of HIF1A-AS2 increased doxorubicin sensitivity of SCLC cells and decreased autophagy. Knockdown of HIF1A-AS2 has also affected the expression of several genes that will increase drug sensitivity and inhibit autophagy in both cell lines. The levels of HIF-1α and Beclin-1 were decreased in both cell lines by knockdown of HIF1A-AS2. MRP1 expression was decrease in H69AR cells. In addition, CoCl₂-induced hypoxic environment decreased in doxorubicin sensitivity of H69 cells, and knockdown of HIF1A-AS2 reversed this effect of hypoxia. Knockdown of HIF1A-AS2 increased drug sensitivity of SCLC cells in relation to autophagy. Therefore, hypoxia-HIF1A-AS2-autophagy interaction is thought to be determinative in drug sensitivity of these cells.

Circ_0084615 is an oncogenic circular RNA in colorectal cancer and promotes DNMT3A expression via repressing miR-599

BACKGROUND

Circular RNAs (circRNAs) are implicated in modulating cancer progression, exerting a pro- or anti-cancer effect. This work is aimed to probe the biological function of circ_0084615 in colorectal cancer (CRC) and its underlying mechanism.

METHODS

Circ_0084615 was selected from two circRNA microarray datasets (GSE138589 and GSE142837). Circ_0084615, microRNA (miR)-599 and DNA methyltransferases 3A (DNMT3A) mRNA expression in CRC tissues and cell lines were examined by qRT-PCR. The relationship between circ_0084615 expression level and clinical features were analyzed with chi-square test. Circ_0084615 knockdown model was constructed by siRNA in two CRC cell lines. The biological functions of circ_0084615 in CRC cells were evaluated by CCK-8 and Transwell experiments. The effect of circ_0084615 on CRC cell metastasis in vivo was examined with lung metastasis model of nude mice. Dual luciferase reporter gene assay was used to determine whether circ_0084615 and miR-599, and miR-599 and DNMT3A interacted with each other. Western blot was employed to examine the regulatory effects of circ_0084615 and miR-599 on DNMT3A protein expression in CRC cells.

RESULTS

Circ_0084615 was up-regulated in CRC and was correlated with poor overall survival rate and advanced clinical stage of CRC patients. Functional assays validated that depletion of circ_0084615 impeded CRC cell proliferation, migration and invasion. Circ_0084615 acted as a molecular sponge for miR-599 to repress its expression. DNMT3A was a downstream target of miR-599. Functional compensation experiments showed that miR-599 inhibitors partially counteracted the the biological effects of silencing circ_0084615 on CRC cells.

CONCLUSIONS

Circ_0084615 is a tumor-promoting circRNA in CRC that functions as a competing endogenous RNA to regulate DNMT3A expression via sponging miR-599. Our research provides a potential therapeutic target for CRC patients.

Role of microRNA-129 in cancer and non-cancerous diseases (Review)

An increasing number of studies indicate that microRNAs (miRNAs/miRs) are involved in diverse biological signaling pathways and play important roles in the progression of various diseases, including both oncological and non-oncological diseases. These small non-coding RNAs can block translation, resulting in a low expression level of target genes. miR-129 is an miRNA that has been the focus of considerable research in recent years. A growing body of evidence shows that the miR-129 family not only functions in cancer, including osteosarcoma, nasopharyngeal carcinoma, and ovarian, prostate, lung, breast and colon cancer, but also in non-cancerous diseases, including heart failure (HF), epilepsy, Alzheimer's disease (AD), obesity, diabetes and intervertebral disc degeneration (IVDD). It is therefore necessary to summarize current research progress on the role of miR-129 in different diseases. The present review includes an updated summary of the mechanisms of the miR-129 family in oncological and non-oncological diseases. To the best of our knowledge, this is the first review focusing on the role of miR-129 in non-cancerous diseases such as obesity, HF, epilepsy, diabetes, IVDD and AD.

Long non-coding RNAs in colorectal cancer: Novel oncogenic mechanisms and promising clinical applications

Colorectal cancer (CRC) is the third most common malignancy and ranks as the second leading cause of cancer-related deaths worldwide. Despite the improvements in CRC diagnosis and treatment approaches, a considerable proportion of CRC patients still suffers from poor prognosis due to late disease detections and lack of personalized disease managements. Recent evidences have not only provided important molecular insights into their mechanistic behaviors but also indicated that identification of cancer-specific long non-coding RNAs (LncRNAs) could benefit earlier disease detections and improve treatment outcomes in patients suffering from CRC. LncRNAs have raised extensive attentions as they participate in various hallmarks of CRC. The mechanistic evidence gleaned in the recent decade clearly reveals that lncRNAs exert their oncogenic roles by regulating autophagy, epigenetic modifications, enhancing stem phenotype and modifying tumor microenvironment. In view of their pleiotropic functional roles in malignant progression, and their frequently dysregulated expression in CRC patients, they have great potential to be reliable diagnostic and prognostic biomarkers, as well as therapeutic targets for CRC. In the present review, we will focus on the oncogenic roles of lncRNAs and related mechanisms in CRC as well as discuss their clinical potential in the early diagnosis, prognostic prediction and therapeutic translation in patients with this malignancy.

The Role of non-coding RNAs in colorectal cancer, with a focus on its autophagy

Colorectal cancer (CRC) is one of malignant afflictions burdening people worldwide, mainly caused by shortages of effective medical intervention and poorly mechanistic understanding of the pathogenesis of CRC. Non-coding RNAs (ncRNAs) are a type of heterogeneous transcripts without the capability of coding protein, but have the potency of regulating protein-coding gene expression. Autophagy is an evolutionarily conserved catabolic process in which cytoplasmic contents are delivered to cellular lysosomes for degradation, resulting in the turnover of cellular components and producing energy for cell functions. A growing body of evidence reveals that ncRNAs, autophagy, and the crosstalks of ncRNAs and autophagy play intricate roles in the initiation, progression, metastasis, recurrence and therapeutic resistance of CRC, which confer ncRNAs and autophagy to serve as clinical biomarkers and therapeutic targets for CRC. In this review, we sought to delineate the complicated roles of ncRNAs, mainly including miRNAs, lncRNAs and circRNAs, in the pathogenesis of CRC, particularly focus on the regulatory role of ncRNAs in CRC-related autophagy, attempting to shed light on the complex pathological mechanisms, involving ncRNAs and autophagy, responsible for CRC tumorigenesis and development, so as to underpin the ncRNAs- and autophagy-based therapeutic strategies for CRC in clinical setting.

LncRNA signature in colorectal cancer

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

The Impact of Non-coding RNAs in the Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is a course of action that enables a polarized epithelial cell to undertake numerous biochemical alterations that allow it to adopt features of mesenchymal cells such as high migratory ability, invasive properties, resistance to apoptosis, and importantly higher-order formation of extracellular matrix elements. EMT has important roles in implantation and gastrulation of the embryo, inflammatory reactions and fibrosis, and transformation of cancer cells, their invasiveness and metastatic ability. Regarding the importance of EMT in the invasive progression of cancer, this process has been well studies in in this context. Non-coding RNAs (ncRNAs) have been shown to exert critical function in the regulation of cellular processes that are involved in the EMT. These processes include regulation of some transcription factors namely SNAI1 and SNAI2, ZEB1 and ZEB2, Twist, and E12/E47, modulation of chromatin configuration, alternative splicing, and protein stability and subcellular location of proteins. In the present paper, we describe the influence of ncRNAs including microRNAs and long non-coding RNAs in the EMT process and their application as biomarkers for this process and cancer progression and their potential as therapeutic targets.

LncRNA HIF1A-AS2 accelerates malignant phenotypes of renal carcinoma by modulating miR-30a-5p/SOX4 axis as a ceRNA

OBJECTIVE

Several reports have proposed that lncRNAs, as potential biomarkers, participate in the progression and growth of malignant tumors. HIF1A-AS2 is a novel lncRNA and potential biomarker, involved in the genesis and development of carcinomas. However, the molecular mechanism of HIF1A-AS2 in renal carcinoma is unclear.

METHODS

The relative expression levels of HIF1A-AS2 and miR-30a-5p were detected using RT-qPCR in renal carcinoma tissues and cell lines. Using loss-of-function and overexpression, the biological effects of HIF1A-AS2 and miR-30a-5p in kidney carcinoma progression were characterized. Dual luciferase reporter gene analysis and Western blot were used to detect the potential mechanism of HIF1A-AS2 in renal carcinomas.

RESULTS

HIF1A-AS2 was upregulated in kidney carcinoma tissues when compared with para-carcinoma tissues (P < 0.05). In addition, tumor size, tumor node mestastasis stage and differentiation were identified as being closely associated with HIF1A-AS2 expression (P < 0.05). Knockdown or overexpression of HIF1A-AS2 either restrained or promoted the malignant phenotype and WNT/β-catenin signaling in renal carcinoma cells (P < 0.05). MiR-30a-5p was downregulated in renal cancers and partially reversed HIF1A-AS2 functions in malignant renal tumor cells. HIF1A-AS2 acted as a microRNA sponge that actively regulated the relative expression of SOX4 in sponging miR-30a-5p and subsequently increased the malignant phenotypes of renal carcinomas. HIF1A-AS2 showed a carcinogenic effect and miR-30a-5p acted as an antagonist of the anti-oncogene effects in the pathogenesis of renal carcinomas.

CONCLUSIONS

The HIF1A-AS2-miR-30a-5p-SOX4 axis was associated with the malignant progression and development of renal carcinoma. The relative expression of HIF1A-AS2 was negatively correlated with the expression of miR-30a-5p, and was closely correlated with SOX4 mRNA levels in renal cancers.

Sonographic Features of Triple-Negative Breast Carcinomas Are Correlated With mRNA-lncRNA Signatures and Risk of Tumor Recurrence

Background

To determine a correlation between mRNA and lncRNA signatures, sonographic features, and risk of recurrence in triple-negative breast cancers (TNBC).

Methods

We retrospectively reviewed the data from 114 TNBC patients having undergone transcriptome analysis. The risk of tumor recurrence was determined based on the correlation between transcriptome profiles and recurrence-free survival. Ultrasound (US) features were described according to the Breast Imaging Reporting and Data System. Multivariate logistic regression analysis determined the correlation between US features and risk of recurrence. The predictive value of sonographic features in determining tumor recurrence was analyzed using receiver operating characteristic curves.

Results

Three mRNAs (CHRDL1, FCGR1A, and RSAD2) and two lncRNAs (HIF1A-AS2 and AK124454) were correlated with recurrence-free survival in patients with TNBC. Among the three mRNAs, two were upregulated (FCGR1A and RSAD2) and one was downregulated (CHRDL1) in TNBCs. LncRNAs HIF1A-AS2 and AK124454 were upregulated in TNBCs. Based on these signatures, an integrated mRNA–lncRNA model was established using Cox regression analysis to determine the risk of tumor recurrence. Benign-like sonographic features, such as regular shape, circumscribed margin, posterior acoustic enhancement, and no calcifications, were associated with HIF1A-AS2 expression and high risk of tumor recurrence (P<0.05). Malignant-like features, such as irregular shape, uncircumscribed margin, no posterior acoustic enhancement, and calcifications, were correlated with CHRDL1 expression and low risk of tumor recurrence (P<0.05).

Conclusions

Sonographic features and mRNA–lncRNA signatures in TNBCs represent the risk of tumor recurrence. Taken together, US may be a promising technique in determining the prognosis of patients with TNBC.

A developmental stage-specific network approach for studying dynamic co-regulation of transcription factors and microRNAs during craniofacial development

Craniofacial development is regulated through dynamic and complex mechanisms that involve various signaling cascades and gene regulations. Disruption of such regulations can result in craniofacial birth defects. Here, we propose the first developmental stage-specific network approach by integrating two crucial regulators, transcription factors (TFs) and microRNAs (miRNAs), to study their co-regulation during craniofacial development. Specifically, we used TFs, miRNAs and non-TF genes to form feed-forward loops (FFLs) using genomic data covering mouse embryonic days E10.5 to E14.5. We identified key novel regulators (TFs Foxm1, Hif1a, Zbtb16, Myog, Myod1 and Tcf7, and miRNAs miR-340-5p and miR-129-5p) and target genes (Col1a1, Sgms2 and Slc8a3) expression of which changed in a developmental stage-dependent manner. We found that the Wnt-FoxO-Hippo pathway (from E10.5 to E11.5), tissue remodeling (from E12.5 to E13.5) and miR-129-5p-mediated Col1a1 regulation (from E10.5 to E14.5) might play crucial roles in craniofacial development. Enrichment analyses further suggested their functions. Our experiments validated the regulatory roles of miR-340-5p and Foxm1 in the Wnt-FoxO-Hippo subnetwork, as well as the role of miR-129-5p in the miR-129-5p-Col1a1 subnetwork. Thus, our study helps understand the comprehensive regulatory mechanisms for craniofacial development.

[Silencing long non-coding RNA HIF1A-AS2 inhibits proliferation, invasion and migration of cervical cancer cells in vitro]

OBJECTIVE

To explore the inhibitory effects of silencing long non-coding RNA (LncRNA) HIF1A-AS2 on epithelialmesenchymal transition (EMT) and tumor stem cell-like phenotype in cervical cancer cells.

METHODS

We designed 3 shRNA constructs for silencing HIF1A-AS2 in CaSki cells, and the shRNA with the strongest interference effect was selected for subsequent experiment. CaSki cells were transfected with shRNA-NC or Sh-HIF1A-AS2, and the changes in cell viability, invasion ability, EMT, expressions of EMT-related proteins, formation of cell spheres and expressions of stem cell markers were detected.

RESULTS

Transfection with shRNA-NC and Sh-HIF1A-AS2 did not significantly affected the viability of CaSki cells (P > 0.05). Compared with the cells transfected with shRNA-NC, the cells transfected with Sh- HIF1A-AS2 showed significantly reduced invasion ability, expressions of vimentin N-cadherin, and cell sphere formation ability. HIF1A-AS2 silencing obviously lowered the rate of ABCG2-positive cells, significantly reduced the mRNA and protein expressions of Nanog, OCT4, and SOX2, and strongly enhanced the expression of E-cadherin in CaSki cells (P < 0.05).

CONCLUSIONS

Silencing HIF1A-AS2 can inhibit proliferation, invasion and migration of cervical cancer cells in vitro.

The oncogenic role of LncRNA FAM83C-AS1 in colorectal cancer development by epigenetically inhibits SEMA3F via stabilizing EZH2

Inactivation of Semaphorin 3F (SEMA3F) is involved in colorectal cancer development. However, the mechanism by which SEMA3F is regulated remains elusive. Deregulation of lncRNAs have been implicated in multiple human malignancies, including colorectal cancer (CRC). To date, it is still unclear whether and how lncRNA regulates SEMA3F expression and mediates CRC progression. Here we identify the oncogenic role of lncRNA FAM83C antisense RNA 1 (FAM83C-AS1) in CRC. FAM83C-AS1 is upregulated in tumor tissues and cells of CRC, which is negatively correlated with SEMA3F expression. Reciprocally, knockdown of FAM83C-AS1 exhibits inhibitory effects on the malignant transformation of CRC. Moreover, our data uncover that FAM83C-AS1 enhances methylation of SEMA3F promoter H3K27me3 via upregulating methyltransferase enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2). Specifically, FAM83C-AS1 stabilizes EZH2 protein through recruiting the zinc finger RANBP2-type containing 1 (ZRANB1). Both in vitro and in vivo rescue assays exhibit that SEMA3F is dispensable for the tumor-promoting effects of FAM83C-AS1 on CRC progression. Our data thus demonstrate that the epigenetic role of FAM83C-AS1 in suppression of SEMA3F expression through stabilization of EZH2 to drive CRC progression, which may be conducive to discovering novel therapeutic targets for the treatment of CRC.

lncRNAHIF1A-AS2 Promotes Renal Carcinoma Cell Proliferation and Migration via miR-130a-5p/ERBB2 Pathway

Background

Long non-coding RNAs (lncRNAs) are essential for tumorigenesis and progression of diverse cancers. This study aims to investigate the roles of lncRNAs on renal carcinoma.

Methods

The expression of lncRNA HIF1A-AS2 in clear cell renal cell carcinoma (ccRCC) and adjacent non-cancer tissues was identified by quantitative real-time PCR (qRT-PCR). Investigations were performed on biological function of lncRNA HIF1A-AS2 on cell proliferation, cell cycle, apoptosis and invasion of ccRCC by overexpression and knockdown experiments. Further, luciferase reporter assay and Western blot were constructed to explore molecular mechanisms underlying the function of lncRNA HIF1A-AS2.

Results

HIF1A-AS2 was highly expressed in kidney cancer tissues and ccRCC cells. Interference of HIF1A-AS2 in vivo hindered cell proliferation, invasion and migration while accelerated cell apoptosis. Overexpression of HIF1A-AS2 presented an opposite effect that repressed the expression of miR-130a-5p, and miR-130a-5p inhibited the expression of HIF1A-AS2. Additionally, rescue experiments exhibited that oncogenic function of HIF1A-AS2 was partially dependent on the suppression of miR-130a-5p.

Conclusion

Our results indicated a critical role for the HIF1A-AS2-miR-130a-5p axis in renal carcinoma progression, which may act as a promising diagnostic biomarker and a pivotal therapeutic target for renal carcinoma cures.

LncRNAs: Potential Novel Prognostic and Diagnostic Biomarkers in Colorectal Cancer

BACKGROUND

Long non-coding RNAs (lncRNAs), a type of regulatory RNAs, play a key role in numerous cellular pathways. Ectopic expression of this group of non-coding RNAs has been specified to be involved in numerous diseases. Moreover, the role of lncRNAs in the initiation and development of cancers including colorectal cancer (CRC) has been acknowledged.

OBJECTIVE

In the present review, the role of lncRNAs as prognostic and diagnostic biomarkers in CRC as well as the molecular mechanisms of their contribution to development of CRC has been addressed.

RESULTS

The presented studies have indicated the ectopic expression of various lncRNAs in CRC. Some lncRNAs which were considered as tumor suppressors were downregulated in the colorectal cancerous tissues compared with healthy controls; however, some with oncogenic effects were upregulated. LncRNAs contribute to tumor development via various molecular mechanisms such as epigenetically controlling the expression of target genes, interacting with miRNAs as their sponge, etc. Conclusion: LncRNAs that have been recognized as prognostic biomarkers may pave the way for clinical management to offer adjuvant treatments for patients with CRC.

Long Noncoding RNA HIF1A-AS2 Promotes Non-Small Cell Lung Cancer Progression by the miR-153-5p/S100A14 Axis

Background

Long noncoding RNA (lncRNA) plays a critical role in initiating lung cancer. This study aims to research the function and mechanism of lncRNA HIF1A-AS2 in regulating non-small cell lung cancer (NSCLC) progression.

Methods

qRT-PCR was used to analyze gene expression. The CCK-8 assay was performed to detect cell proliferation. The Transwell assay was conducted to examine cell migration and invasion. A Caspase3 activity detection kit was utilized to analyze apoptosis. The luciferase reporter assay was carried out to research interactions of HIF1A-AS2, miR-153-5p and S100A14.

Results

HIF1A-AS2 expression was raised in NSCLC tissues and cell lines. The HIF1A-AS2 level was increased in advanced NSCLC tumor tissues. High HIF1A-AS2 expression was related to poor prognosis. HIF1A-AS2 knockdown decreased proliferation, migration and invasion while promoting apoptosis. HIF1A-AS2 was the sponge for miR-153-5p, and miR-153-5p targeted S100A14. HIF1A-AS2 promoted S100A14 expression through regulating miR-153-5p.

Conclusion

The HIF1A-AS2/miR-153-5p/S100A14 axis plays a crucial role in promoting NSCLC progression.

EWSAT1 Acts in Concert with Exosomes in Osteosarcoma Progression and Tumor-Induced Angiogenesis: The "Double Stacking Effect"

The prognosis for osteosarcoma (OS) continues to be unsatisfactory due to tumor recurrence as a result of metastasis and drug resistance. Several studies have shown that Ewing sarcoma associated transcript 1 (EWSAT1) plays an important role in the progression of OS. Exosomes (Exos) act as important carriers in intercellular communication and play an important role in the tumor microenvironment, especially in tumor-induced angiogenesis. Nonetheless, the specific mechanism via which EWSAT1 and Exos regulate OS progression is unknown, and whether they can be effective therapeutic targets also requires verification. Hence, in this study, it is aimed to investigate the mechanisms of action of EWSAT1 and Exos. EWSAT1 significantly promotes proliferation, migration, colony formation, and survival of OS. EWSAT1 regulates OS-induced angiogenesis via two mechanisms, called the "double stacking effect," which is a combination of the increase in sensitivity/reactivity of vascular endothelial cells triggered by Exos-carrying EWSAT1, and the EWSAT1-induced increase in angiogenic factor secretion. In vivo experiments further validates the "double stacking effect" and shows that EWSAT1-KD effectively inhibits tumor growth in OS. The above observations indicate that EWSAT1 can be used as not only a potential diagnostic and prognostic marker, but also as a precise therapeutic target for OS.

Regulation of DNA methylation machinery by epi-miRNAs in human cancer: emerging new targets in cancer therapy

Disruption in DNA methylation processes can lead to alteration in gene expression and function that would ultimately result in malignant transformation. In this way, studies have shown that, in cancers, methylation-associated silencing inactivates tumor suppressor genes, as effectively as mutations. DNA methylation machinery is composed of several genes, including those with DNA methyltransferases activity, proteins that bind to methylated cytosine in the promoter region, and enzymes with demethylase activity. Based on a prominent body of evidence, DNA methylation machinery could be regulated by microRNAs (miRNAs) called epi-miRNAs. Numerous studies demonstrated that dysregulation in DNA methylation regulators like upstream epi-miRNAs is indispensable for carcinogenesis; consequently, the malignant capacity of these cells could be reversed by restoring of this regulatory system in cancer. Conceivably, recognition of these epi-miRNAs in cancer cells could not only reveal novel molecular entities in carcinogenesis, but also render promising targets for cancer therapy. In this review, at first, we have an overview of the methylation alteration in cancers, and the effect of this phenomenon in miRNAs expression and after that, we conduct an in-depth discussion about the regulation of DNA methylation regulators by epi-miRNAs in cancer cells.

Long non-coding RNA (lncRNA) and epithelial-mesenchymal transition (EMT) in colorectal cancer: a systematic review

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer-related death. Epithelial-mesenchymal transition (EMT) is a major process in tumor metastasis development. This systematic review aims to describe the role of long non-coding RNA (lncRNA) in EMT in CRC.

METHODS

The electronic databases, PubMed, Cochrane, and EMBASE, were searched from January1990 to June 2019 to identify studies examining lncRNA and their role in mediating EMT in CRC. Studies examining clinical specimens and/or in vitro experiments were included.

RESULTS

In 61 identified studies, 54 lncRNAs were increased in CRC compared to normal colorectal epithelium. Increased lncRNA expression was frequently associated with worse survival. Many lncRNAs mediate their effect through competitive endogenous RNA or transcription factor regulation. The ZEB1, 2/E-cadherin, Wnt/β-catenin signaling, and chromatin remodeling pathways are discussed in particular.

CONCLUSIONS

lncRNAs are major regulators of EMT and predictor adverse outcome in CRC patients. Future research must focus on delineating lncRNA function prior to potential clinical use.

Long non-coding RNAs and MYC association in hematological malignancies

Long non-coding RNAs (lncRNAs) have an established role in cell biology. Among their functions is the regulation of hematopoiesis. They characterize the different stages of hematopoiesis in a more lineage-restricted expression pattern than coding mRNAs. They affect hematopoietic stem cell renewal, proliferation, and differentiation of committed progenitors by interacting with master regulators transcription factors. Among these transcription factors, MYC has a prominent role. Similar to MYC's transcriptional activation/amplification of protein coding genes, MYC also regulates lncRNAs' expression profile, while it is also regulated by lncRNAs. Both myeloid and lymphoid malignancies are prone to the association of MYC with lncRNAs. Such interaction inhibits apoptosis, enhances cell proliferation, deregulates metabolism, and promotes genomic instability and resistance to treatment. In this review, we discuss the recent findings that encompass the crosstalk between lncRNAs and describe the pathways that very probably have a pathogenetic role in both acute and chronic hematologic malignancies.

HCG18/miR-34a-5p/HMMR axis accelerates the progression of lung adenocarcinoma

As the most common subtype of lung cancer, lung adenocarcinoma (LUAD) is the frequently occurred cancers in human. Therefore, thorough investigation is necessary for understanding the progression of LUAD. HMMR has functioned as a regulator in some cancers, whereas its biological role still needs to be investigated in LUAD. By bioinformatics analysis, we found that HMMR was highly expressed in LUAD tissues and associated with patients' poor prognosis. Further, qRT-PCR demonstrated that HMMR was up-regulated in LUAD tissues and cells. Loss-of-function assays manifested that HMMR knockdown refrained cell proliferation, migration and invasion and enhanced cell apoptosis in LUAD. Later, HMMR was identified as a target gene of miR-34a-5p, which expressed at a low level in LUAD cell and played an anti-oncogenic role in LUAD. Simultaneously, we discovered that miR-34a-5p could directly bind to HCG18. Subsequent assays revealed that HCG18 mediated HMMR expression by sequestering miR-34a-5p. At last, rescue assays proved the carcinogenic role of HCG18/miR-34a-5p/HMMR axis in LUAD cells growth. Importantly, HCG18 was found to facilitate tumor growth in LUAD. Conclusively, HCG18 acted an oncogene in LUAD and enhanced LUAD progression by targeting miR-34a-5p/HMMR axis.

Knockdown of HIF1A-AS2 suppresses TRIM44 to protect cardiomyocytes against hypoxia-induced injury

Myocardial infarction (MI) is a common cardiovascular disease characterized by an interruption of blood and oxygen supply to the heart, which results in gradual damage to the myocardial tissue and ultimately heart failure. The role of long non-coding RNAs in the pathology of MI remains in its infancy, but has been implicated in MI and other heart conditions. For example, the expression of a non-coding RNA hypoxia-inducible factor 1α (HIF1A)-antisense RNA 2 (HIF1A-AS2) has previously been linked to coronary heart disease, however, whether HIF1A-AS2 expression is also high in MI has not been addressed. Here, we report that HIF1A-AS2 is upregulated in hypoxia-treated human cardiomyocytes (HMCs) compared with normal cardiomyocytes, and that silenced HIF1A-AS2 inhibited apoptosis and facilitated viability, migration, and invasion of HMCs. Our data suggested that in MI, HIF1A-AS2 upregulation was associated with miR-623, which promoted expression of tripartite motif containing 44 (TRIM44). Moreover, by upregulating TRIM44 we were able to remedy the HIF1A-AS2 repression of apoptosis in HMCs. Thus, we conclude that cardiomyocytes can be protected against hypoxic-treated injury by knockdown of HIF1A-AS2, which suppresses TRIM44, and that HIF1A-AS2 overexpression is a prognostic indicator of MI.

Long noncoding RNA HIF1A-AS2 facilitates cell survival and migration by sponging miR-33b-5p to modulate SIRT6 expression in osteosarcoma

Long noncoding RNAs (lncRNAs) are emerging as vital regulators in various physiological and pathological processes. It was recently found that lncRNA HIF1A-AS2 could play oncogenic roles in several cancers. However, the function and regulatory mechanism of lncRNA HIF1A-AS2 in osteosarcoma (OS) remain largely unclear. In this study, we demonstrated that HIF1A-AS2 was overexpressed in OS tissues and cells. Downregulation of HIF1A-AS2 significantly affects multiple biological functions in OS cells, including cell proliferation, cell cycle progression, cell apoptosis, cell migration, and cell invasiveness. Mechanistic investigations demonstrated that HIF1A-AS2 can interact with miR-33b-5p and negatively regulate its expression, thereby upregulating the protein expression of miR-33b-5p’s target SIRT6. Additionally, in vivo experiments using a xenograft tumor mouse model revealed that downregulation of HIF1A-AS2 suppresses tumor growth in OS. Taken together, a newly identified regulatory mechanism for the lncRNA HIF1A-AS2–miR-33b-5p–SIRT6 axis was systematically studied in OS, which could be a promising target for the treatment of OS.

HNF1A-AS1 Regulates Cell Migration, Invasion and Glycolysis via Modulating miR-124/MYO6 in Colorectal Cancer Cells

Background

Accumulating evidence determined that lncRNAs play multiple roles in cell progression in colorectal cancer (CRC). Long noncoding RNA (lncRNA) hepatocyte nuclear factor 1 homeobox A (HNF1A)-antisense RNA 1 (AS1) has been identified to affect cell growth and disease diagnosis in various cancers, including CRC. However, the underlying regulatory mechanism of HNF1A-AS1 in cell progression and glycolysis has not been fully explored in CRC.

Materials and Methods

The expression of HNF1A-AS1, microRNA-124 (miR-124) and Myosins of class VI (MYO6) was detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The analysis of glucose consumption, lactate production and hexokinase 2 (HK2) protein level was used to assess glycolysis in cells. The protein level of HK2 and MYO6 was measured with Western blot. Cell migration and invasion were evaluated using the transwell assay. The relationship among HNF1A-AS1, miR-124 and MYO6 was determined via luciferase reporter and RNA immunoprecipitation (RIP) assay.

Results

In this study, we found that HNF1A-AS1 was upregulated in CRC tissues and cell lines. Functional experiments determined that reduction of HNF1A-AS1 or promotion of miR-124 inhibited cell migration and invasion as well as glycolysis in CRC cells. What’ more, luciferase reporter assay manifested that miR-124 was a target of HNF1A-AS1 and MYO6 was a target mRNA of miR-124 in CRC cells. Additionally, reverse experiments showed that the effects of si-HNF1A-AS1 on colorectal cancer cells were impaired by anti-miR-124 and the effects of high miR-124 expression on CRC cells were rescued by upregulating MYO6. HNF1A-AS1 regulated MYO6 expression via targeting miR-124 in CRC cells.

Conclusion

In this study, we first found that HNF1A-AS1 regulated cell migration, invasion and glycolysis via modulating miR-124/MYO6 in CRC cells.

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.

UNC5B-AS1 promoted ovarian cancer progression by regulating the H3K27me on NDRG2 via EZH2

The role of long non-coding RNAs (lncRNAs) in tumorigenesis and development of ovarian cancer (OC) has caught the attention of scientists. UNC5B antisense RNA 1 (UNC5B-AS1) is a newly identified carcinogenic lncRNA in thyroid papillary carcinoma, but its role in OC remains unclear. This study is proposed to investigate the function and mechanism of UNC5B-AS1 in OC. UNC5B-AS1 expression in OC samples was obtained from gene expression profiling interactive analysis (GEPIA) based on The Cancer Genome Atlas data. Gene expressions were detected by quantitative real-time polymerase chain reaction (RT-qPCR) and western blot. Biological functions of UNC5B-AS1 were assessed by cell counting kit-8, colony formation, and caspase-3 analysis. GEPIA revealed the UNC5B-AS1 upregulation in OC samples. RT-qPCR assay confirmed the upregulation of UNC5B-AS1 in OC cells. Functionally, depletion of UCN5B-AS1 hindered proliferation and prompted apoptosis in OC cells. Mechanistically, we found that UNC5B-AS1 interacted with zeste 2 polycomb repressive complex 2 subunit (EZH2) to trigger trimethylation of histone H3 at lysine 27 (H3K27me3) on N-myc downstream regulated gene-2 (NDRG2) promoter and epigenetically repressed NDRG2. Rescue assay indicated the participation of NDRG2 in the regulation of UNC5B-AS1 on OC progression. Together, we first illustrated that UNC5B-AS1 promoted OC progression by regulating the H3K27me on NDRG2 via EZH2, indicating UNC5B-AS1 as a potential molecular target for OC treatment.

LncRNA CASC9 Affects Cell Proliferation, Migration, and Invasion of Tongue Squamous cell Carcinoma via Regulating miR-423-5p/SOX12 Axes

Introduction

The incidence of tongue squamous cell carcinoma (TSCC) has increased in recent decades. However, the function of long non-coding RNA (lncRNA) CASC9 in the occurrence and progression of TSCC is unclear. In this work, we attempted to clarify the role of lncRNA CASC9 in determining the phenotype of TSCC cells, and to clarify the underlying mechanisms.

Methods

We used qRT-PCR analysis to identify the level of CASC9 mRNA expression in TSCC clinical samples and cell lines. We investigated cell proliferation, and cell migration and invasion of TSCC cells transfected with siCASC9 or siNC using CCK-8 and transwell assays. Bioinformatics analysis and a luciferase reporter assay were employed to predict and verify the target microRNA (miRNA).

Results

CASC9 was up-regulated in the TSCC tissues and cells, and predicted a poor prognosis. CASC9 silencing significantly inhibited cell proliferation, migration, and invasion of the TSCC cells compared with the non-targeting control small interfering RNA (siCtrl) treatment. miR-423-5p was predicted as the targeting miRNA of CASC9; this was verified by a luciferase reporter assay. CASC9 expression showed a negative correlation with miR-423-5p expression and a positive correlation with SOX12 expression. The miR-423-5p inhibitor can rescue the carcinogenesis effect of CASC9 on TSCC cells.

Conclusion

Our work indicates that CASC9 plays a role in TSCC tumorigenesis; this novel information will improve TSCC molecular targeting therapy.

MiR-129-5p sensitization of lung cancer cells to etoposide-induced apoptosis by reducing YWHAB

Background: Lung cancer is the most common cause of death from cancer worldwide and recent studies have revealed that microRNAs play critical roles to regulate lung carcinogenesis. microRNA-129-5p (miR-129-5p) has been reported to regulate cell proliferation and invasion in lung cancer, but its role in lung cancer apoptosis remains unknown.

Methods: The expression of miR-129-5p and YWHAB in lung cancer tissues were analyzed from data downloaded from the NCBI Gene Expression Omnibus (GEO) database. Luciferase reporter assay, Western blot and qRT-PCR were used to determine the regulatory effect of miR-129-5p on YWHAB. Cell apoptosis was detected by using the PI/Annexin V Cell Apoptosis Kit. The effect of miR-129-5p and YWHAB on the survival of lung cancer patients was also explored.

Results: In this study, by combining the data derived from six GEO database, our results showed that miR-129-5p was downregulated in lung cancer tissues and YWHAB was upregulated in lung cancer patient' serum. A significant negative correlation between miR-129-5p and YWHAB was found in lung cancer tissues. Both the expression of YWHAB and miR-129-5p were associated significantly with prognosis (overall survival) in patients with lung cancer. Overexpression of miR-129-5p promotes VP16-induced lung cancer cell apoptosis and YWHAB was shown to be a direct downstream target of miR-129-5p.

Conclusion: Overexpression of expression miR-129-5p contributes to etoposide-induced lung cancer apoptosis by modulating YWHAB.

MiR-129-5p promotes docetaxel resistance in prostate cancer by down-regulating CAMK2N1 expression

This study focuses on the effect of miR‐129‐5p on docetaxel‐resistant (DR) prostate cancer (PCa) cells invasion, migration and apoptosis. In our study, the expression of CAMK2N1 was assessed by qRT‐PCR in PCa patient tissues and cell lines including PC‐3 and PC‐3‐DR. Cells transfected with miR‐129‐5p mimics, inhibitor, CAMK2N1 or negative controls (NC) were used to interrogate their effects on DR cell invasions, migrations and apoptosis during docetaxel (DTX) treatments. The apoptosis rate of the PCa cells was validated by flow cytometry. Relationships between miR‐129‐5p and CAMK2N1 levels were identified by qRT‐PCR and dual‐luciferase reporter assay. CAMK2N1 was found to be down‐expressed in DR PCa tissue sample, and low levels of CAMK2N1 were correlated with high docetaxel resistance and clinical prediction of poor survival. CAMK2N1 levels were decreased in DR PCa cells treated with DXT. We further explored that up‐regulation of miR‐129‐5p could promote DR PCa cells viability, invasion and migration but demote apoptosis. Involved molecular mechanism studies revealed that miR‐129‐5p reduced downstream CAMK2N1 expression to further impact on chemoresistance to docetaxel of PCa cells, indicating its vital role in PCa docetaxel resistance. Our findings revealed that miR‐129‐5p contributed to the resistance of PC‐3‐DR cells to docetaxel through suppressing CAMK2N1 expression, and thus targeting miR‐129‐5p may provide a novel therapeutic approach in sensitizing PCa to future docetaxel treatment.

LncRNA HIF1A-AS2 promotes osteosarcoma progression by acting as a sponge of miR-129-5p

Increasing studies have demonstrated that long noncoding RNAs (lncRNAs) play vital roles in tumor development and progression. However, the relationship between osteosarcoma and HIF1AAS2 remains unknown. The expression of HIF1AAS2 and miR-129-5p was detected in osteosarcoma cell lines and samples via qRT-PCR. Cell Counting Kit-8 (CCK-8) and invasion assays were performed to determine cell proliferation and invasion ability, and a dual luciferase reporter assay was performed to determine the interaction between HIF1AAS2 and miR-129-5p. We showed that the expression of HIF1A-AS2 was upregulated in the osteosarcoma samples compared with the expression in noncancerous samples. Moreover, patients with high HIF1A-AS2 expression had a shorter overall survival. Ectopic expression of HIF1A-AS2 enhanced osteosarcoma cell proliferation, cell cycle progression and invasion. We found that overexpression of miR-129-5p decreased the luciferase activity of wild-type (WT) HIF1A-AS2 but not mutant HIF1A-AS2. Ectopic expression of HIF1A-AS2 suppressed miR-129-5p expression in MG-63 cells. We demonstrated that miR-129-5p was downregulated in osteosarcoma and was negatively associated with HIF1A-AS2 expression. Furthermore, ectopic expression of miR-129-5p suppressed osteosarcoma cell proliferation, cell cycle progression and invasion. In addition, overexpression of HIF1A-AS2 promoted cell proliferation, cell cycle progression and invasion of osteosarcoma cells through the modulation of miR-129-5p. These results indicated that HIF1A-AS2 might be a potential therapeutic target for osteosarcoma.

ZEB2-AS1 Accelerates Epithelial/Mesenchymal Transition Through miR-1205/CRKL Pathway in Colorectal Cancer

Background: Accumulating reports have demonstrated that long-noncoding RNAs (lncRNAs) play critical roles in the pathological progression of colorectal cancer (CRC). However, the role of lncRNA zinc finger E-box binding homeobox 2 antisense RNA 1 (ZEB2-AS1) in CRC remains largely unknown. Methods: The authors detected the ZEB2-AS1 expression in CRC tissue sample and CRC cell lines. The effects of ZEB2-AS1 on CRC were identified through in vitro assays (i.e., transwell assay, wound-healing assay, immunofluorescence assay, and Western blot) in a ZEB2-AS1 knockdown system. The molecular mechanism of ZEB2-AS1 was explored via bioinformatic tools, quantitative real-time polymerase chain reaction (qRT-PCR), dual-luciferase reporter assay, RNA immunoprecipitation assay, and so on. Moreover, a series of gain-of-function experiments were performed to identify the effect of ZEB2-AS1 and miR-1205 on epithelial-to-mesenchymal transition (EMT) in CRC cells. Results: This analysis clarified that ZEB2-AS1 was upregulated in both CRC tissue sample and cells lines; meanwhile, the high expression of ZEB2-AS1 was correlated with poor overall survival rate. ZEB2-AS1 knockdown significantly suppresses the EMT in CRC cells. Furthermore, the authors identified that the expression of ZEB2-AS1 was negatively correlated with expression of miR-1205, and CRKL could be a direct target of miR-1205. Through the gain-of-function experiments, they found that ZEB2-AS1 accelerates EMT in CRC cells via modulating the expression of miR-1205 and CRKL. Conclusion: Taken together, this study revealed that ZEB2-AS1 accelerates EMT in CRC through the miR-1205/CRKL pathway, suggesting that ZEB2-AS1 may potentially serve as a target of CRC.