Long noncoding RNA FEZF1-AS1 in human cancers

Knockdown of lncRNA SNHG20 Suppressed the Proliferation of Cholangiocarcinoma by Sponging miR-520f-3p

Objective: A large number of studies had found that small nucleolar RNA host gene 20 (SNHG20) was a long noncoding RNA (lncRNA) that played important regulatory functions in numerous tumors. Nevertheless, the expression and pathophysiological role of SNHG20 in cholangiocarcinoma (CCA) are currently unclear. The objective of this study is to reveal the clinical significance and pathophysiological function of SNHG20 in CCA. Methods: The tumor tissues and adjacent normal tissues of CCA were obtained to determine the expression and clinical significance of SNHG20, and the targets of related genes were predicted through bioinformatics analysis. The function and regulatory mechanism of SNHG20 in CCA were evaluated by transfection, CCK-8 experiment, and luciferase reporter assay. Result: In CCA, SNHG20 was highly expressed. Overexpressed SNHG20 was markedly interrelated with the lymph node invasion and TNM stage. In addition, it could be used as indicator to evaluate the prognosis of patients. SNHG20 sponging miR-520f-3p could accelerate the proliferation of CCA tumor cells. MiR-520f-3p acted as a tumor suppressor in CCA and could also serve as a prognostic indicator. Abolition of miR-520f-3p caused an antagonistic effect and diminished the impacts of SNHG20 knockdown. SNHG20 combined with miR-520f-3p could better predict the prognosis of CCA patients. Conclusion: These data confirmed the knockdown SNHG20 expression in CCA could inhibit the proliferation by means of sponging miR-520f-3p.

LncRNA PRBC induces autophagy to promote breast cancer progression through modulating PABPC1-mediated mRNA stabilization

Breast cancer is one of the major malignant tumors among women worldwide. Long noncoding RNAs (lncRNAs) have been documented as significant modulators in the development and progression of various cancers; however, the contribution of lncRNAs to breast cancer remains largely unknown. In this study, we found a novel lncRNA (NONHSAT137675) whose expression was significantly increased in the breast cancer tissues. We named the novel lncRNA as lncRNA PRBC (PABPC1-related lncRNA in breast cancer) and identified it as a key lncRNA associated with breast cancer progression and prognosis. Functional analysis displayed that lncRNA PRBC could promote autophagy and progression of breast cancer. Mechanistically, we verified that lncRNA PRBC physically interacted with PABPC1 through RIP assay, and PABPC1 overexpression could reverse the inhibiting effect of lncRNA PRBC knockdown on the malignant behaviors in breast cancer cells. Knockdown of lncRNA PRBC interfered the translocation of PABPC1 from nucleus to cytoplasm as indicated by western blot and IF assays. Significantly, the cytoplasmic location of PABPC1 was required for the interaction between PABPC1 and AGO2, which could be enhanced by lncRNA PRBC overexpression, leading to strengthened recruitment of mRNA to RNA-induced silencing complex (RISC) and thus reinforcing the inhibition efficiency of miRNAs. In general, lncRNA PRBC played a critical role in malignant progression of breast cancer by inducing the cytoplasmic translocation of PABPC1 to further regulate the function of downstream miRNAs. This study provides novel insight on the molecular mechanism of breast cancer progression, and lncRNA PRBC might be a promising therapeutic target and prognostic predictor for breast cancer.

Preeclampsia-associated lncRNA FEZF1-AS1 regulates cell proliferation and apoptosis in placental trophoblast cells through the ELAVL1/NOC2L axis

BACKGROUND

LncRNAs have been shown to be involved in and control the biological processes of multiple diseases, including preeclampsia (PE). The impairment of trophoblast cell proliferation is recognized as a significant anomaly contributing to the development of PE. LncRNA FEZF1-AS1 was found downregulated in placental tissues of PE patients. However, the precise regulatory mechanism of FEZF1-AS1 in placental trophoblast proliferation and apoptosis remains unclear.

RESULTS

In this study, we conducted an investigation into the expression levels of FEZF1-AS1 and NOC2L in placental tissues obtained from patients diagnosed with PE. Subsequently, we employed CCK-8 and EdU assays to quantify cell proliferation, while TUNEL staining and western blot for apoptosis-related protein detection to assess apoptosis. Furthermore, the interactions between FEZF1-AS1 and ELAVL1, as well as NOC2L and ELAVL1, were confirmed through the implementation of RIP and RNA pull-down assays. We found a downregulation of lncRNA FEZF1-AS1 and NOC2L in placental tissues of PE patients. Overexpression of FEZF1-AS1 or NOC2L resulted in increased cell proliferation and inhibition of apoptosis, whereas knockdown of FEZF1-AS1 or NOC2L had the opposite effect. In addition, lncRNA FEZF1-AS1 stabilized NOC2L mRNA expression by interacting with ELAVL1. Moreover, partial reversal of the effects of FEZF1-AS1 overexpression on cell proliferation and apoptosis was observed upon suppression of ELAVL1 or NOC2L.

CONCLUSIONS

PE related lncRNA FEZF1-AS1 could regulate apoptosis and proliferation of placental trophoblast cells through the ELAVL1/NOC2L axis.

LncRNA FEZF1-AS1 accelerates multiple myeloma progression by regulating IGF2BP1/BZW2 signaling

Multiple myeloma (MM) is the second largest hematological tumor with clonal proliferation of malignant plasma cells. Growing reports have revealed that the dysregulation of long non-coding RNA (lncRNA) is involved in the MM progression. Nevertheless, lncRNA FEZF1 antisense RNA 1 (FEZF1-AS1) remain not deeply explored. The RNA transcripts and protein level of MM-associated molecule were measured by quantitative real-time polymerase chain reaction or western blot assays, respectively. The clinical correlation was analyzed by Pearson analysis. Molecular interactions among lncRNA FEZF1-AS1, basic leucine zipper and W2 domain 2 (BZW2) and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) were verified by RNA immunoprecipitation and RNA pull-down assays. The survival of MM cells was detected by cell counting kit-8 and flow cytometry assays. Xenograft tumor in vivo was performed to assess tumor growth. The RNA transcripts of lncRNA FEZF1-AS1, BZW2 and IGF2BP1 were upregulated in MM samples compared to those in healthy donors. Knockdown of lncRNA FEZF1-AS1 could inhibit the proliferation and induce cell apoptosis in vitro and in vivo. Besides, lncRNA FEZF1-AS1 could maintain the stability of BZW2 mRNA by interacting IGF2BP1. Moreover, BZW2 silence also downregulated the proliferation but enhanced apoptosis of MM cells, while BZW2 overexpression had an opposite role, which dramatically reversed the regulatory roles of lncRNA FEZF1-AS1. Altogether, lncRNA FEZF1-AS1 facilitated MM development by regulating IGF2BP1/BZW2 signaling, suggesting that lncRNA FEZF1-AS1 might be a candidate for MM treatment.

HMGA2 regulation by miRNAs in cancer: affecting cancer hallmarks and therapy response

High mobility group A 2 (HMGA2) is a protein that modulates the structure of chromatin in the nucleus. Importantly, aberrant expression of HMGA2 occurs during carcinogenesis, and this protein is an upstream mediator of cancer hallmarks including evasion of apoptosis, proliferation, invasion, metastasis, and therapy resistance. HMGA2 targets critical signaling pathways such as Wnt/β-catenin and mTOR in cancer cells. Therefore, suppression of HMGA2 function notably decreases cancer progression and improves outcome in patients. As HMGA2 is mainly oncogenic, targeting expression by non-coding RNAs (ncRNAs) is crucial to take into consideration since it affects HMGA2 function. MicroRNAs (miRNAs) belong to ncRNAs and are master regulators of vital cell processes, which affect all aspects of cancer hallmarks. Long ncRNAs (lncRNAs) and circular RNAs (circRNAs), other members of ncRNAs, are upstream mediators of miRNAs. The current review intends to discuss the importance of the miRNA/HMGA2 axis in modulation of various types of cancer, and mentions lncRNAs and circRNAs, which regulate this axis as upstream mediators. Finally, we discuss the effect of miRNAs and HMGA2 interactions on the response of cancer cells to therapy. Regarding the critical role of HMGA2 in regulation of critical signaling pathways in cancer cells, and considering the confirmed interaction between HMGA2 and one of the master regulators of cancer, miRNAs, targeting miRNA/HMGA2 axis in cancer therapy is promising and this could be the subject of future clinical trial experiments.

Constructed the ceRNA network and predicted a FEZF1-AS1/miR-92b-3p/ZIC5 axis in colon cancer

The purpose of this study was to identify the role of FEZF1-AS1 in colon cancer and predicted the underlying mechanism. We extracted sequencing data of colon cancer patients from The Cancer Genome Atlas database, identified the differential expression of long noncoding RNA, microRNA, and messenger RNA, constructed a competitive endogenous RNA network, and then analyzed prognosis. Then, we used the enrichment analysis databases for functional analysis. Finally, we studied the FEZF1-AS1/miR-92b-3p/ZIC5 axis. We detected the expression of FEZF1-AS1, miR-92b-3p, and ZIC5 via quantitative reverse transcription-PCR, transfected colon cancer cell RKO with lentivirus and conducted FEZF1-AS1 knockdown, and performed cancer-related functional assays. It indicated that many RNA in the competitive endogenous RNA network, such as ZIC5, were predicted to be related to overall survival of colon cancer patients, and enrichment analysis showed cancer-related signaling pathways, such as PI3K/AKT signaling pathway. The expression of FEZF1-AS1 and ZIC5 was significantly higher and that of miR-92b-3p was lower in the colon cancer than in the normal colon tissues. FEZF1-AS1 promoted the migration, proliferation, as well as invasion of RKO. According to the prediction, FEZF1-AS1 and ZIC5 might competitively bind to miR-92b-3p, leading to the weakening of the inhibitory impact of miR-92b-3p on ZIC5 and increasing expression of ZIC5, thus further activating the PI3K/AKT signaling pathway, which led to the occurrence and development of colon cancer. The study suggested that FEZF1-AS1 might be an effective diagnosis biomarker for colon cancer.

Long Noncoding RNA Mediated Regulation in Human Embryogenesis, Pluripotency, and Reproduction

Long noncoding RNAs (lncRNAs), a class of noncoding RNAs with more than 200 bp in length, are produced by pervasive transcription in mammalian genomes and regulate gene expression through various action mechanisms. Accumulating data indicate that lncRNAs mediate essential biological functions in human development, including early embryogenesis, induction of pluripotency, and germ cell development. Comprehensive analysis of sequencing data highlights that lncRNAs are expressed in a stage-specific and human/primate-specific pattern during early human development. They contribute to cell fate determination through interacting with almost all classes of cellular biomolecules, including proteins, DNA, mRNAs, and microRNAs. Furthermore, the expression of a few of lncRNAs is highly associated with the pathogenesis and progression of many reproductive diseases, suggesting that they could serve as candidate biomarkers for diagnosis or novel targets for treatment. Here, we review research on lncRNAs and their roles in embryogenesis, pluripotency, and reproduction. We aim to identify the underlying molecular mechanisms essential for human development and provide novel insight into the causes and treatments of human reproductive diseases.

LncRNA FEZF1-AS1 Promotes Multi-Drug Resistance of Gastric Cancer Cells via Upregulating ATG5

Long non-coding RNAs (lncRNAs) play important roles in human cancers including gastric cancer (GC). Dysregulation of lncRNAs is involved in a variety of pathological activities associated with gastric cancer progression and chemo-resistance. However, the role and molecular mechanisms of FEZF1-AS1 in chemoresistance of GC remain unknown. In this study, we aimed to determine the role of FEZF1-AS1 in chemoresistance of GC. The level of FEZF1-AS1 in GC tissues and GC cell lines was assessed by qRT-PCR. Our results showed that the expression of FEZF1-AS1 was higher in gastric cancer tissues than in adjacent normal tissues. Multivariate analysis identified that high level of FEZF1-AS1 is an independent predictor for poor overall survival. Increased FEZF1-AS1 expression promoted gastric cancer cell proliferation in vitro. Additionally, FEZF1-AS1 was upregulated in chemo-resistant GC tissues. The regulatory effect of FEZF1-AS1 on multi-drug resistance (MDR) in GC cells and the underlying mechanism was investigated. It was found that increased FEZF1-AS1 expression promoted chemo-resistance of GC cells. Molecular interactions were determined by RNA immunoprecipitation (RIP) and the results showed that FEZF1-AS1 regulated chemo-resistance of GC cells through modulating autophagy by directly targeting ATG5. The proliferation and autophagy of GC cells promoted by overexpression of LncFEZF1-AS1 was suppressed when ATG5 was knocked down. Moreover, knockdown of FEZF1-AS1 inhibited tumor growth and increased 5-FU sensitivity in GC cells in vivo. Taken together, this study revealed that the FEZF1-AS1/ATG5 axis regulates MDR of GC cells via modulating autophagy.

Long Noncoding Competing Endogenous RNA Networks in Pancreatic Cancer

Pancreatic cancer (PC) is a highly malignant disease characterized by insidious onset, rapid progress, and poor therapeutic effects. The molecular mechanisms associated with PC initiation and progression are largely insufficient, hampering the exploitation of novel diagnostic biomarkers and development of efficient therapeutic strategies. Emerging evidence recently reveals that noncoding RNAs (ncRNAs), including long ncRNAs (lncRNAs) and microRNAs (miRNAs), extensively participate in PC pathogenesis. Specifically, lncRNAs can function as competing endogenous RNAs (ceRNAs), competitively sequestering miRNAs, therefore modulating the expression levels of their downstream target genes. Such complex lncRNA/miRNA/mRNA networks, namely, ceRNA networks, play crucial roles in the biological processes of PC by regulating cell growth and survival, epithelial-mesenchymal transition and metastasis, cancer stem cell maintenance, metabolism, autophagy, chemoresistance, and angiogenesis. In this review, the emerging knowledge on the lncRNA-associated ceRNA networks involved in PC initiation and progression will be summarized, and the potentials of the competitive crosstalk as diagnostic, prognostic, and therapeutic targets will be comprehensively discussed.

lncRNA FEZF1-AS1 regulates biological behaviors of cervical cancer by targeting miRNA-1254

AIM

The purpose of this research was to evaluate lncRNA FEZF1-AS1 in cervical cancer development and clinical significance.

MATERIALS AND METHODS

Collecting cervical cancer tissues, measuring FEZF1-AS1 expression, and analysis correlation between FEZF1-AS1 and prognosis. In cell vitro study, using MTT assay to measure cell proliferation, evaluating cell apoptosis by flow cytometry, measuring cell invasion and migration by Transwell and wound healing assay; lncRNA FEZF1-AS1 and miR-1254 gene expressions were evaluated by RT-qPCR assay; relative protein (Smurf1, E-cadherin, Vimentin, N-cadherin, AKT, p-AKT, c-Myc, and ZEB1) expressions were measured by Western blot assay. The correlation among FEZF1-AS1, miR-1254, and Smurf1 were analysis by dual luciferase reporter gene assay.

RESULTS

By clinical analysis, lncRNA FEZF1-AS1 was high expression in cervical cancer tissues and high expression was closely correlated with poor prognosis in cervical cancer patients. In vitro study, the SiHa and HeLa cell biologically including cell proliferation, migration, and invasion of si-FEZF1-AS1 group which knockdown lncRNA FEZF1-AS1 were significantly depressed (p < .001, respectively). However, with miR-1254 expression inhibiting, the cell biological activities were significantly increased in si-FEZF1-AS1+miRNA inhibitor groups (p < .001, respectively).

CONCLUSION

lncRNA FEZF1-AS1 might be an oncological role in cervical cancer; lncRNA FEZF1-AS1 knockdown had antitumor effects with miR-1254 activating in cervical cancer by in vitro study.

lncRNA and Mechanisms of Drug Resistance in Cancers of the Genitourinary System

Available systemic treatment options for cancers of the genitourinary system have experienced great progress in the last decade. However, a large proportion of patients eventually develop resistance to treatment, resulting in disease progression and shorter overall survival. Biomarkers indicating the increasing resistance to cancer therapies are yet to enter clinical routine. Long non-coding RNAs (lncRNA) are non-protein coding RNA transcripts longer than 200 nucleotides that exert multiple types of regulatory functions of all known cellular processes. Increasing evidence supports the role of lncRNAs in cancer development and progression. Additionally, their involvement in the development of drug resistance across various cancer entities, including genitourinary malignancies, are starting to be discovered. Consequently, lncRNAs have been suggested as factors in novel therapeutic strategies to overcome drug resistance in cancer. In this review, the existing evidences on lncRNAs and their involvement in mechanisms of drug resistance in cancers of the genitourinary system, including renal cell carcinoma, bladder cancer, prostate cancer, and testicular cancer, will be highlighted and discussed to facilitate and encourage further research in this field. We summarize a significant number of lncRNAs with proposed pathways in drug resistance and available reported studies.

Diagnostic value of HOX transcript antisense RNA for cancer detection: a meta-analysis

Aim: Numerous studies have investigated the diagnostic role of long noncoding RNA HOX transcript antisense RNA in cancers, but its diagnostic efficacy is inconsistent. Methods: The PubMed, Embase, Web of Science and Cochrane Library databases are used to retrieve relevant studies. The bivariate effect model was used to compute the combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the receiver operating characteristic curve. Results: A total of 13 studies were included in this meta-analysis. The combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the receiver operating characteristic curve were: 0.77, 0.83, 4.7, 0.28, 17 and 0.87, respectively. Deeks' funnel plot test (p = 0.103) indicated no publication bias. Conclusion: Long noncoding RNA HOX transcript antisense RNA may be a useful biomarker for cancer detection.

Long noncoding RNA LINC00963 promotes breast cancer progression by functioning as a molecular sponge for microRNA-625 and thereby upregulating HMGA1

Extensive research has shown that LINC00963 is aberrantly expressed in human cancers, and that dysregulation of LINC00963 is implicated in the initiation and progression of human cancers. The expression and functions of LINC00963 in breast cancer are still unclear. Our aims were to measure the expression of LINC00963 in breast cancer, determine its effects on malignant behaviors of tumor cells, and uncover the molecular events underlying the actions of LINC00963 in breast cancer. Herein, LINC00963 was found to be overexpressed in breast cancer samples, and its overexpression was correlated with lymph node metastasis, TNM stage and differentiation grade. Patients with breast cancer harboring higher LINC00963 expression showed shorter overall survival than did the patients with lower LINC00963 expression. Functional experiments revealed that depletion of LINC00963 inhibited breast cancer cell proliferation, migration, and invasion and facilitated apoptosis in vitro and impaired tumor growth in vivo. Mechanism investigation revealed that LINC00963 can interact with microRNA-625 (miR-625). LINC00963 worked as a competitive endogenous RNA for miR-625 to weaken the suppressive effect of miR-625 on high mobility group AT-hook 1 (HMGA1) in breast cancer cells. Furthermore, miR-625 inhibition and HMGA1 restoration both abrogated the effects of LINC00963 silencing on breast cancer cells. Our findings indicate that the LINC00963-miR-625-HMGA1 pathway plays an important role in the malignancy of breast cancer in vitro and in vivo. Hence, targeting this pathway may be a novel strategy against breast cancer.

Antisense lncRNA LDLRAD4-AS1 promotes metastasis by decreasing the expression of LDLRAD4 and predicts a poor prognosis in colorectal cancer

Long noncoding RNAs (lncRNAs) have been revealed to play critical roles in tumor initiation and progression. The antisense lncRNA LDLRAD4-AS1 is the longest lncRNA of LDLRAD4, and its expression levels, cellular localization, precise function, and mechanism in colorectal cancer (CRC) remain unknown. In this study, we observed that lncRNA LDLRAD4-AS1 was located in the nucleus of CRC cells and that lncRNA LDLRAD4-AS1 was upregulated in most CRC specimens and cell lines. Overexpression of lncRNA LDLRAD4-AS1 was correlated with poor prognosis in CRC patients. LncRNA LDLRAD4-AS1 upregulation enhanced the migration and invasion of CRC cells in vitro and facilitated CRC metastasis in vivo. Mechanistic investigations suggested that lncRNA LDLRAD4-AS1 could decrease the expression of LDLRAD4 by disrupting the stability of LDLRAD4 mRNA, resulting in epithelial-to-mesenchymal transition (EMT) through upregulating Snail, thereby promoting metastasis in CRC. Our results demonstrated a previously unrecognized LDLRAD4-AS1-LDLRAD4-Snail regulatory axis involved in epigenetic and posttranscriptional regulation that contributes to CRC progression and metastasis.

Long non-coding RNA ASMTL-AS1 inhibits tumor growth and glycolysis by regulating the miR-93-3p/miR-660/FOXO1 axis in papillary thyroid carcinoma

Long non-coding RNA (lncRNA) is emerging as an essential player in cancer progression. However, its biological function and clinical implication in papillary thyroid carcinoma (PTC) remain poorly understood. In the current study, we found that a novel lncRNA, ASMTL antisense RNA 1 (ASMTL-AS1), was significantly downregulated in PTC. And its downregulation was positively linked to larger tumor size, advanced clinical stage and unfavorable outcome. Overexpression of ASMTL-AS1 evidently inhibited PTC cell proliferation and glycolysis, while knockdown of ASMTL-AS1 resulted in the opposite effect. Regarding the mechanism, ASMTL-AS1 was capable of sponging miR-93-3p and miR-660 to elevate FOXO1 expression, leading to repressing glycolysis and tumorigenesis. In turn, FOXO1 could also increase ASMTL-AS1 expression via directly binding to ASMTL-AS1 promoter, which formed a positive feedback regulation loop. Importantly, the regulatory axis of ASMTL-AS1/miR-93-3p/miR-660/FOXO1 was also identified in vivo. Collectively, our data clearly indicate that ASMTL-AS1 functions as a novel tumor suppressor in PTC through regulation of miR-93-3p/miR-660/FOXO1 pathway. Targeting ASMTL-AS1 and its downstream pathway may be an effective therapeutic approach for patients with PTC.

Long noncoding RNA TP73-AS1 in human cancers

Long noncoding RNAs (lncRNAs) play an important role in tumor development. With the development of sequencing technology, many new lncRNAs have been discovered. lncRNA TP73-AS1 is abnormally expressed in many cancers. A summary of the current literature related to TP73-AS1 reveals that TP73-AS1 mainly regulates the occurrence and development of tumors through the mechanism of competitive endogenous RNA (ceRNA). In addition, the abnormal expression of TP73-AS1 can regulate the malignant function of tumor cells through a variety of possible mechanisms. All evidence suggests that TP73-AS1 may be a potential diagnostic biomarker or a new cancer therapeutic target.