Long Noncoding RNA FEZF1-AS1 Promotes Proliferation and Inhibits Apoptosis in Ovarian Cancer by Activation of JAK-STAT3 Pathway

Role of STAT3 in cancer cell epithelial‑mesenchymal transition (Review)

Since its discovery, the role of the transcription factor, signal transducer and activator of transcription 3 (STAT3), in both normal physiology and the pathology of numerous diseases, including cancer, has been extensively studied. STAT3 is aberrantly activated in different types of cancer, fulfilling a critical role in cancer progression. The biological process, epithelial‑mesenchymal transition (EMT), is indispensable for embryonic morphogenesis. During the development of cancer, EMT is hijacked to confer motility, tumor cell stemness, drug resistance and adaptation to changes in the microenvironment. The aim of the present review was to outline recent advances in knowledge of the role of STAT3 in EMT, which may contribute to the understanding of the function of STAT3 in EMT in various types of cancer. Delineating the underlying mechanisms associated with the STAT3‑EMT signaling axis may generate novel diagnostic and therapeutic options for cancer treatment.

The regulatory relationship between transcription factor STAT3 and noncoding RNA

Signal transducer and activator of transcription 3 (STAT3), as a key node in numerous carcinogenic signaling pathways, is activated in various tumor tissues and plays important roles in tumor formation, metastasis, and drug resistance. STAT3 is considered a potential subtarget for tumor therapy. Noncoding RNA (ncRNA) is a special type of RNA transcript. Transforming from "junk" transcripts into key molecules involved in cell apoptosis, growth, and functional regulation, ncRNA has been proven to be closely related to various epithelial-mesenchymal transition and drug resistance processes in tumor cells over the past few decades. Research on the relationship between transcription factor STAT3 and ncRNAs has attracted increased attention. To date, existing reviews have mainly focused on the regulation by ncRNAs on the transcription factor STAT3; there has been no review of the regulation by STAT3 on ncRNAs. However, understanding the regulation of ncRNAs by STAT3 and its mechanism is important to comprehensively understand the mutual regulatory relationship between STAT3 and ncRNAs. Therefore, in this review, we summarize the regulation by transcription factor STAT3 on long noncoding RNA, microRNA, and circular RNA and its possible mechanisms. In addition, we provide an update on research progress on the regulation of STAT3 by ncRNAs. This will provide a new perspective to comprehensively understand the regulatory relationship between transcription factor STAT3 and ncRNAs, as well as targeting STAT3 or ncRNAs to treat diseases such as tumors.

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.

Up-regulation of BOK-AS1, FAM215A and FEZF1-AS1 lncRNAs and their potency as moderate diagnostic biomarkers in gastric cancer

BACKGROUND

Gastric cancer is the fifth most frequent cancer worldwide and the fourth leading cause of death from cancer, a complex multifactorial neoplasm. LncRNAs are regulatory RNA molecules larger than 200 nucleotides, which can have profound effects on the oncogenic process of various types of cancer. Therefore, these molecules can be used as diagnostic and therapeutic biomarkers. This study aimed to determine the differences in BOK-AS1, FAM215A, and FEZF1-AS1 gene expression between tumor tissue and adjacent healthy non-tumor tissue of gastric cancer (GC) patients.

METHODS

In this study one hundred pairs of cancerous and non-cancerous marginal tissues were gathered. Next, RNA extraction and cDNA synthesis were achieved for all of the samples. Then, the qRT-PCR was performed to measure the expression of BOK-AS1, FAM215A and FEZF1-AS1 genes.

RESULTS

All BOK-AS1, FAM215A and FEZF1-AS1 genes showed significantly increased expression in tumor tissues compared with non-tumor tissues. The outcome of the ROC analysis demonstrated that BOK-AS1, FAM215A, and FEZF1-AS1 may act as mean biomarkers with AUC of 0.7368, 0.7163 and 0.7115, specificity of 64%, 61% and 59%, and sensitivity of 74%, 70%, and 74% respectively.

CONCLUSION

Based on the increased expression of the BOK-AS1, FAM215A and FEZF1-AS1 genes in GC patients, this study suggests that these genes may function as oncogenic factors. Furthermore, the mentioned genes can be considered as intermediate biomarkers for diagnosis and treatment of gastric cancer. In addition, no association between these genes and clinicopathological features was observed.

LncRNA EN-90756 promotes CPB2-induced proliferation and inhibits apoptosis in IPEC-J2 cells by affecting the JAK-STAT signaling pathway activation

Background

Long non-coding RNAs (lncRNAs), as key regulators, are closely associated with the development of a variety of disease. However, the mechanisms by which lncRNAs regulate Clostridium perfringens type C induced piglet diarrhea are unclear.

Methods

In the present study, we explored the expression and characterization of lncRNAs in a C. perfringens beta2 (CPB2) toxin-treated intestinal porcine epithelial cell line-J2 (IPEC-J2) using RNA-sequencing (RNA-seq).

Results

A total of 6,558 lncRNAs were identified, of which 49 lncRNAs were significantly differentially expressed between the control and CPB2 groups. Functional enrichment analysis showed that the target genes of differentially expressed lncRNA EN-90756 were mainly associated with defense response to virus, and negative regulation of apoptotic process. LncRNA EN-90756 was significantly up-regulated in IPEC-J2 cells at different time points after CPB2 treatment. Functionally, knockdown of lncRNA EN-90756 might regulate the proliferation and apoptosis of IPEC-J2 cells by affecting the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway. LncRNA EN-90756 may be involved in CPB2 toxin-induced piglet diarrhea by regulating the expression of its target gene MX1 (encoding MX dynamin like GTPase 1).

Conclusion

Long non-coding RNA EN-90756 affected the antiviral ability of IPEC-J2 cells by regulating the expression of MX1. Meanwhile, lncRNA EN-90756 might regulate cell proliferation and apoptosis by affecting JAK-STAT signaling pathway activation. These findings provide novel perspectives and directions for further exploration of the regulatory mechanisms of lncRNAs on CPB2 toxin-induced diarrhea in piglets.

Long Noncoding RNAs and Circular RNAs Regulate AKT and Its Effectors to Control Cell Functions of Cancer Cells

AKT serine-threonine kinase (AKT) and its effectors are essential for maintaining cell proliferation, apoptosis, autophagy, endoplasmic reticulum (ER) stress, mitochondrial morphogenesis (fission/fusion), ferroptosis, necroptosis, DNA damage response (damage and repair), senescence, and migration of cancer cells. Several lncRNAs and circRNAs also regulate the expression of these functions by numerous pathways. However, the impact on cell functions by lncRNAs and circRNAs regulating AKT and its effectors is poorly understood. This review provides comprehensive information about the relationship of lncRNAs and circRNAs with AKT on the cell functions of cancer cells. the roles of several lncRNAs and circRNAs acting on AKT effectors, such as FOXO, mTORC1/2, S6K1/2, 4EBP1, SREBP, and HIF are explored. To further validate the relationship between AKT, AKT effectors, lncRNAs, and circRNAs, more predicted AKT- and AKT effector-targeting lncRNAs and circRNAs were retrieved from the LncTarD and circBase databases. Consistently, using an in-depth literature survey, these AKT- and AKT effector-targeting database lncRNAs and circRNAs were related to cell functions. Therefore, some lncRNAs and circRNAs can regulate several cell functions through modulating AKT and AKT effectors. This review provides insights into a comprehensive network of AKT and AKT effectors connecting to lncRNAs and circRNAs in the regulation of cancer cell functions.

Liensinine Inhibits Osteosarcoma Growth by ROS-Mediated Suppression of the JAK2/STAT3 Signaling Pathway

Osteosarcoma (OS) is the most common malignancy of bone. Liensinine exerts antitumor effects on cancers of the colon, breast, and gallbladder. However, its antitumor activity in OS remains unclear. This study is aimed at investigating the efficacy of liensinine against OS and the underlying mechanism of action. Cell proliferation, apoptosis, and cycle arrest in OS were detected using the Cell Counting Kit-8 (CCK-8), colony formation, and flow cytometry assays, respectively. The production of reactive oxygen species (ROS), glutathione (GSH) and glutathione disulfide (GSSG) concentrations, and mitochondrial membrane potential (MMP) of OS cells were measured by flow cytometry, colorimetry, and JC-1 staining. The expressions of factors related to apoptosis, cell cycle, and activation of the JAK2/STAT3 pathway were determined by Western blotting. To examine the potential role of ROS, an antioxidant (N-acetyl cysteine, NAC) was used in combination with liensinine. In vivo, we generated a xenograft mouse model to assess its antitumor efficacy. Tissue level expressions of factors related to apoptosis and activation of the JAK2/STAT3 pathway were assessed by immunohistochemistry or Western blotting. Liensinine inhibited the proliferation and induced G0/G1 phase arrest and apoptosis of OS cells in a dose-dependent manner. Additionally, liensinine promoted intracellular ROS production, enhanced the GSSG/GSH ratio, and induced MMP loss and ROS-mediated suppression of the JAK2/STAT3 pathway. NAC significantly attenuated the liensinine-induced antitumor activities and activated the JAK2/STAT3 pathway. In vivo, liensinine effectively inhibited the OS growth and promoted apoptosis; however, it had no negative effect on the internal organs. In conclusion, liensinine-induced ROS production could suppress the activation of the JAK2/STAT3 pathway and inhibit the OS growth both in vivo and in vitro. Our findings provided a new rationale for subsequent academic and clinical research on OS treatment.

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.

The role of non-coding RNAs in chemotherapy for gastrointestinal cancers

Gastrointestinal (GI) cancers, including colorectal, gastric, hepatic, esophageal, and pancreatic tumors, are responsible for large numbers of deaths around the world. Chemotherapy is the most common approach used to treat advanced GI cancer. However, chemoresistance has emerged as a critical challenge that prevents successful tumor elimination, leading to metastasis and recurrence. Chemoresistance mechanisms are complex, and many factors and pathways are involved. Among these factors, non-coding RNAs (ncRNAs) are critical regulators of GI tumor development and subsequently can induce resistance to chemotherapy. This occurs because ncRNAs can target multiple signaling pathways, affect downstream genes, and modulate proliferation, apoptosis, tumor cell migration, and autophagy. ncRNAs can also induce cancer stem cell features and affect the epithelial-mesenchymal transition. Thus, ncRNAs could possibly act as new targets in chemotherapy combinations to treat GI cancer and to predict treatment response.

Knockdown of long noncoding RNA AC245100.4 inhibits the tumorigenesis of prostate cancer cells via the STAT3/NR4A3 axis

Aim: To explore the role and mechanism of long noncoding RNA AC245100.4 and NR4A3 in prostate cancer (PCa). Methods: RNA-sequencing analysis was used to detect the downstream genes of AC245100.4. A series of gain- and loss-of-function approaches were used to investigate the roles of AC245100.4 and NR4A3. RNA immunoprecipitation was performed to examine the interaction between AC245100.4 and STAT3. Results: AC245100.4 was significantly upregulated in PCa cells and tissues. Knockdown of AC21500.4 significantly inhibited the tumorigenesis of PCa cells. Mechanistically, AC245100.4 deregulated the transcription of NR4A3 via increasing p-STAT3, which acted as a transcriptional repressor of NR4A3. Conclusion: Knockdown of long noncoding RNA AC245100.4 inhibits the tumorigenesis of PCa cells via the STAT3/NR4A3 axis.

Up-Regulated LncRNA FEZF1-AS1 Promotes the Progression of Cervical Carcinoma Cells via MiR-367-3p/SLC12A5 Signal Axis

BACKGROUND

Cervical cancer (CC) is a common female malignant tumor. With the trend of younger onset, people pay more and more attention to it. Numberless evidence has been indicated that long non-coding RNAs (lncRNAs) can take part in progression of cancers and can exert the regulatory roles in assorted cancers. Nevertheless, the roles of FEZ family zinc finger 1-antisense RNA 1 (FEZF1-AS1) in CC cells are still undiscovered.

AIM OF THE STUDY

Thus, the central purpose of our research was to reveal the specific functions and molecular mechanisms of FEZF1-AS1 in CC cells.

METHODS

RT-qPCR was utilized to test FEZF1-AS1 expression in CC cells. In addition, functional assays were conducted to evaluate cell proliferation, apoptosis, and migration as well as invasion. In addition, mechanism experiments verified relationship among FEZF1-AS1, miR-367-3p and solute carrier family 12 member 5 (SLC12A5).

RESULTS

FEZF1-AS1 was highly expressed in CC cells. Moreover, FEZF1-AS1 depletion suppressed proliferation, migration, invasion, and induced cell apoptosis. Importantly, mechanism experiments confirmed that miR-367-3p could bissnd to FEZF1-AS1 and SLC12A5. The rescue assays determined that FEZF1-AS1 could up-regulate SLC12A5 through binding to miR-367-3p.

CONCLUSIONS

The up-regulated FEZF1-AS1 could accelerate the malignant behaviors of CC cells by miR-367-3p/SLC12A5 signal axis.

LncRNA FEZF1-AS1 accelerates the migration and invasion of laryngeal squamous cell carcinoma cells through miR-4497 targeting GBX2

BACKGROUND

MiR-4497 has been previously proved to exert an anti-cancer role in laryngeal squamous cell carcinoma (LSCC) by negatively regulating gastrulation brain homeobox 2 (GBX2). However, the mechanism of miR-4497 in LSCC has yet to be fully elucidated. This study intended to investigate the role of FEZF1-AS1 in the migration and invasion of LSCC cells and clarified its mechanism through miR-4497 and GBX2.

METHODS

qPCR evaluated the expression of FEZF1-AS1, miR-4497 and GBX2 in LSCC tissues and cells, compared with controls. Western blotting analyzed GBX2, E-cadherin, N-cadherin and Vimentin. CCK8, wound healing and transwell assays assessed the viability, migration and invasion of TU686 and UM-SCC-17A cells. Luciferase reporter assay affirmed the interplay of miR-4497 with FEZF1-AS1 or GBX2 and Pearson's correlation analysis explored the association between each two genes in both tumor and non-tumor tissues.

RESULTS

FEZF1-AS1 was highly expressed in LSCC tissues and cells. Silence or elevation of FEZF1-AS1 inhibited or promoted the migration and invasion of TU686 and UM-SCC-17A cells. FEZF1-AS1 targeted and negatively modulated miR-4497. Inhibition of miR-4497 markedly restored the FEZF1-AS1 silence-repressed cell viability of TU686 and UM-SCC-17A cells. Further, FEZF1-AS1 could positively regulate GBX2 via negative regulation of miR-4497. In these two cells, GBX2 deficiency reversed the promoting impacts of miR-4497 repression on migration and invasion.

CONCLUSION

Taken together, FEZF1-AS1, heightened in LSCC tissues and cells, promotes cell migration and invasion of LSCC cells via targeting miR-4497 that inhibits GBX2. The finding may offer new options for the treatment of this cancer.

Inhibition of long non-coding RNA XIST upregulates microRNA-149-3p to repress ovarian cancer cell progression

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) play critical roles in human diseases. We aimed to clarify the role of lncRNA X-inactive specific transcript (XIST)/miR-149-3p/forkhead box P3 (FOXP3) axis in ovarian cancer (OC) cell growth. XIST, miR-149-3p and FOXP3 expression in OC tissues and cell lines was assessed, and the predictive role of XIST in prognosis of OC patients was analyzed. The OC cell lines were screened and accordingly treated with silenced/overexpressed XIST plasmid or miR-149-3p mimic/inhibitor, and then the proliferation, invasion, migration, colony formation ability, apoptosis, and cell cycle distribution of OC cells were measured. Effect of altered XIST and miR-149-3p on tumor growth in vivo was observed. Online website prediction and dual luciferase reporter gene were implemented to detect the targeting relationship of lncRNA XIST, miR-149-3p, and FOXP3. XIST and FOXP3 were upregulated, whereas miR-149-3p was downregulated in OC tissues and cells. High XIST expression indicated a poor prognosis of OC. Inhibition of XIST or elevation of miR-149-3p repressed proliferation, invasion, migration, and colony formation ability, and promoted apoptosis and cell cycle arrest of HO-8910 cells. In SKOV3 cells upon treatment of overexpressed XIST or reduction of miR-149-3p, there exhibited an opposite tendency. Based on online website prediction, dual luciferase reporter gene, and RNA pull-down assays, we found that there was a negative relationship between XIST and miR-149-3p, and miR-149-3p downregulated FOXP3 expression. This study highlights that knockdown of XIST elevates miR-149-3p expression to suppress malignant behaviors of OC cells, thereby inhibiting OC development.

ELK1 activated-long noncoding RNA LBX2-AS1 aggravates the progression of ovarian cancer through targeting miR-4784/KDM5C axis

As one of the most common cancers in female, ovarian cancer (OC) has become a serious public burden now. Mounting researches have indicated long noncoding RNAs (lncRNAs) can affect many biological processes including cancer development. LncRNA LBX2-AS1 was identified to be an oncogene in some cancers, but the role of LBX2-AS1 in OC remains to be elucidated. Bioinformatics analysis and experiments including ChIP, RT-qPCR, RIP, luciferase reporter, western blot and CCK-8 were performed to explore the role of LBX2-AS1 in OC. LBX2-AS1 expression was markedly increased in OC tissues and cell lines. Functionally, LBX2-AS1 silencing inhibited cell proliferation, migration and stemness but facilitated cell apoptosis in OC. Moreover, depletion of LBX2-AS1 suppressed tumor growth of OC in vivo. Mechanically, LBX2-AS1 was activated by transcriptional factor ELK1. ELK1 enhanced the expression of LBX2-AS1 in OC cells. In addition, miR-4784 was confirmed to be sponged by LBX2-AS1. There was a negative expression correlation between LBX2-AS1 and miR-4784 in OC tissues. Subsequently, KDM5C was identified to be a direct target of miR-4784 in OC cells. KDM5C was negatively regulated by miR-4784 and positively regulated by LBX2-AS1 in terms of expression level. Upregulation of KDM5C reversed the inhibitory effect of LBX2-AS1 depletion on the progression of OC. This study proved that ELK1 activated-LBX2-AS1 aggravated the progression of OC by targeting the miR-4784/KDM5C axis, suggesting that LBX2-AS2 may be a promising diagnostic biomarker of OC.

Long Non-coding RNA FEZF1-AS1 Promotes Growth and Reduces Apoptosis Through Regulation of miR-363-3p/PAX6 Axis in Retinoblastoma

Retinoblastoma is the most common malignancy in children's eyes with high incidence. Long non-coding RNAs (lncRNAs) play important roles in the progression of retinoblastoma. LncRNA FEZF1 antisense RNA 1 (FEZF1-AS1) has been found to stimulate retinoblastoma. However, the mechanism of FEZF1-AS1 underlying progression of retinoblastoma is still unclear. In current study, FEZF1-AS1 was up-regulated in retinoblastoma tissues and cells. FEZF1-AS1 overexpression enhanced retinoblastoma cell viability, promoted cell cycle, and inhibited apoptosis. Conversely, FEZF1-AS1 knockdown reduced cell viability, cycle, and elevated apoptosis. The interaction between FEZF1-AS1 and microRNA-363-3p (miR-363-3p) was confirmed. FEZF1-AS1 down-regulated miR-363-3p and up-regulated PAX6. PAX6 was a target gene of miR-363-3p. EZF1-AS1 promoted retinoblastoma cell viability and suppressed apoptosis via PAX6. Further, we demonstrated that FEZF1-AS1 contribute to tumor formation in vivo. In conclusion, FEZF1-AS1 elevated growth and inhibited apoptosis by regulating miR-363-3p/PAX6 in retinoblastoma, which provide a new target for retinoblastoma treatment.

Dual relationship between long non-coding RNAs and STAT3 signaling in different cancers: New insight to proliferation and metastasis

Uncontrolled growth and metastasis of cancer cells is an increasing challenge for overcoming cancer, and improving survival of patients. Complicated signaling networks account for proliferation and invasion of cancer cells that need to be elucidated for providing effective cancer therapy, and minimizing their malignancy. Long non-coding RNAs (lncRNAs) are RNA molecules with a length of more than 200 nucleotides. They participate in cellular events, and their dysregulation in a common phenomenon in different cancers. Noteworthy, lncRNAs can regulate different molecular pathways, and signal transducer and activator of transcription 3 (STAT3) is one of them. STAT3 is a tumor-promoting factors in cancers due to its role in cancer proliferation (cell cycle progression and apoptosis inhibition) and metastasis (EMT induction). LncRNAs can function as upstream mediators of STAT3 pathway, reducing/enhancing its expression. This dual relationship is of importance in affecting proliferation and metastasis of cancer cells. The response of cancer cells to therapy such as chemotherapy and radiotherapy is regulated by lncRNA/STAT3 axis. Tumor-promoting lncRNAs including NEAT1, SNHG3 and H19 induces STAT3 expression, while tumor-suppressing lncRNAs such as MEG3, PTCSC3 and NKILA down-regulate STAT3 expression. Noteworthy, upstream mediators of STAT3 such as microRNAs can be regulated by lncRNAs. These complicated signaling networks are mechanistically described in the current review.

Gynecologic cancers and non-coding RNAs: Epigenetic regulators with emerging roles

Gynecologic cancers involve the female genital organs, such as the vulva, vagina, cervix, endometrium, ovaries, and fallopian tubes. The occurrence and frequency of gynecologic cancer depends on personal lifestyle, history of exposure to viruses or carcinogens, genetics, body shape, and geographical habitat. For a long time, research into the molecular biology of cancer was broadly restricted to protein-coding genes. Recently it has been realized that non-coding RNAs (ncRNA), including long noncoding RNAs (LncRNAs), microRNAs, circular RNAs and piRNAs (PIWI-interacting RNAs), can all play a role in the regulation of cellular function within gynecological cancer. It is now known that ncRNAs are able to play dual roles, i.e. can exert both oncogenic or tumor suppressive functions in gynecological cancer. Moreover, several clinical trials are underway looking at the biomarker and therapeutic roles of ncRNAs. These efforts may provide a new horizon for the diagnosis and treatment of gynecological cancer. Herein, we summarize some of the ncRNAs that have been shown to be important in gynecological cancers.

Cancer and SOX proteins: New insight into their role in ovarian cancer progression/inhibition

Transcription factors are potential targets in disease therapy, particularly in cancer. This is due to the fact that transcription factors regulate a variety of cellular events, and their modulation has opened a new window in cancer therapy. Sex-determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are potential transcription factors that are involved in developmental processes such as embryogenesis. It has been reported that abnormal expression of SOX proteins is associated with development of different cancers, particularly ovarian cancer (OC). In the present review, our aim is to provide a mechanistic review of involvement of SOX members in OC. SOX members may suppress and/or promote aggressiveness and proliferation of OC cells. Clinical studies have also confirmed the potential of transcription factors as diagnostic and prognostic factors in OC. Notably, studies have demonstrated the relationship between SOX members and other molecular pathways such as ST6Ga1-I, PI3K, ERK and so on, leading to more complexity. Furthermore, SOX members can be affected by upstream mediators such as microRNAs, long non-coding RNAs, and so on. It is worth mentioning that the expression of each member of SOX proteins is corelated with different stages of OC. Furthermore, their expression determines the response of OC cells to chemotherapy. These topics are discussed in this review to shed some light on role of SOX transcription factors in OC.

Knockdown of DANCR Suppressed the Biological Behaviors of Ovarian Cancer Cells Treated with Transforming Growth Factor-β (TGF-β) by Sponging MiR-214

BACKGROUND Ovarian cancer is one of the most common gynecological malignancies and mortality ranks the highest in cancer-associated death in females' worldwide. Here, we attempted to evaluate the effect of DANCR on the biological behavior of transforming growth factor-ß (TGF-ß) stimulated ovarian cancer cells. MATERIAL AND METHODS The expression of DANCR in ovarian cancer cells (A2780 and SKOV3) treated with TGF-ß were detected by quantitative real-time polymerase chain reaction (qRT-PCR). DANCR silencing was constructed using lentiviral transfection in ovarian cancer cells. The Cell Counting Kit-8 (CCK-8), flow cytometry and Transwell assays were performed to measure some cytology index. Western blot was utilized to explore the effect of DANCR on Krüppel-like factor 5 (KLF5) expression. RESULTS The expression of DANCR in cancer cells (A2780 and SKOV3) treated with TGF-ß was significantly higher. DANCR silencing suppressed cell viability, migration and invasion, and induced cell apoptosis of TGF-ß treated ovarian cancer cells. Bioinformatics analysis showed that DANCR served as a sponge for miR-214, and also showed that KLF5 was targeted by miR-214. In addition, DANCR could inhibit the expression of KLF5. CONCLUSIONS We are the first to report that knockdown of DANCR could affect the biological process of ovarian cancer cells treated with TGF-ß by sponging miR-214, which may provide new therapeutic ideas of ovarian cancer.

Long Non-coding RNA MINCR Regulates miR-876-5p/GSPT1 Axis to Aggravate Glioma Progression

Emerging evidence underlined the crucial roles played by long non-coding RNAs (lncRNAs) in glioma. MINCR has been reported in multiple malignancies. Here, we studied its function and potential mechanism in glioma, which remain unclear. Gene expressions were analyzed by qRT-PCR assay. Both in vitro and in vivo assays were conducted to evaluate the cellular function of MINCR in glioma. The subcellular situation of MINCR was detected by subcellular fractionation and FISH assays. Luciferase reporter, RNA pull-down and RNA immunoprecipitation (RIP) assays were combined to investigate potential mechanisms of relevant genes. MINCR was up-regulated in glioma. MINCR depletion markedly refrained glioma cell proliferation, migration and invasion via sponging miR-876-5p. MiR-876-5p suppressed the malignant behaviors of glioma via binding to GSPT1. MINCR shared the binding sites with the 3'-untranslated region of GSPT1 and prevented the binding of miR-876-5p to GSPT1 mRNA, thus up-regulating the level of GSPT1. Moreover, miR-876 inhibition and GSPT1 up-regulation counteracted the functional effect induced by silencing MINCR on glioma progression. Our findings uncovered that MINCR might aggravated glioma cell proliferation and migration via acting as competing endogenous RNA (ceRNA), indicating prospective novel therapeutic target for glioma.

The Challenges and Opportunities of LncRNAs in Ovarian Cancer Research and Clinical Use

Ovarian cancer is one of the most lethal gynecological malignancies worldwide because it tends to be detected late, when the disease has already spread, and prognosis is poor. In this review we aim to highlight the importance of long non-coding RNAs (lncRNAs) in diagnosis, prognosis and treatment choice, to make progress towards increasingly personalized medicine in this malignancy. We review the effects of lncRNAs associated with ovarian cancer in the context of cancer hallmarks. We also discuss the molecular mechanisms by which lncRNAs become involved in cellular physiology; the onset, development and progression of ovarian cancer; and lncRNAs' regulatory mechanisms at the transcriptional, post-transcriptional and post-translational stages of gene expression. Finally, we compile a series of online resources useful for the study of lncRNAs, especially in the context of ovarian cancer. Future work required in the field is also discussed along with some concluding remarks.

Overexpression of LINC00691 promotes the proliferation and invasion of gastric cancer cells via the Janus kinase/signal transducer and activator of transcription signalling pathway

This report aims to explore how LINC00691 regulates the proliferation and invasion of gastric cancer (GC). Clinical tissue and serum samples, as well as specimens in the Cancer Genome Atlas (TCGA) database, were used to analyse the expression of LINC00691 in GC. Our data indicated that the expression of LINC00691 in GC was significantly higher than that in healthy controls and was associated with clinicopathological features and survival time. In the GC cell lines MKN-45 and HGC-27, the knockdown of LINC00691 suppressed proliferation, colony formation, migration, and invasion. Bioinformatics analysis and luciferase reporter gene experiments showed that LINC00691 activated Lin28 transcription. Western blot analysis indicated that the knockdown of LINC00691 contributed to the decreased expression of p-JAK2 and p-STAT3 in GC cells. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway inhibitor ruxolitinib effectively suppressed the effects of LINC00691. In addition, both LINC00691 and Lin28 promoted the expression of epidermal growth factor (EGF). Therefore, our study clarified that LINC00691 is highly expressed in GC and is a potential biomarker for GC diagnosis and prognosis. LINC00691 promotes the proliferation and invasion of GC cells by activating Lin28 transcription and facilitating EGF expression through the JAK/STAT signalling pathway, which provides new ideas for targeted therapy of GC.

Long Non-Coding RNA FEZF1-AS1 Modulates CXCR4 to Promote Cell Proliferation, Warburg Effect and Suppress Cell Apoptosis in Osteosarcoma by Sponging miR-144

BACKGROUND

Osteosarcoma (OS) is a common bone tumor among children, adolescents, and young adults. Long non-coding RNA (lncRNA) FEZF1 antisense RNA 1 (FEZF1-AS1) has been reported as an oncogene in diverse tumors including colorectal cancer, pancreatic cancer and hepatocellular carcinoma, as well as in osteosarcoma. This study focused on the functions and mechanism of lncRNA FEZF1-AS1 in osteosarcoma.

METHODS

The levels of FEZF1-AS1, microRNA miR-144 and CXC motif chemokine receptor 4 (CXCR4) in OS tissues and cells (Saos-2 and HOS) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot assay. The interactions between miR-144 and FEZF1-AS1 or CXCR4 were predicted by DIANA tools online database. Then, the dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to validate the interactions. Moreover, the cell viability and apoptotic rate in transferred Saos-2 and HOS cells were assessed via 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay and flow cytometry, respectively. The levels of glucose and lactate productions were measured by glucose uptake and lactate production assay. In addition, the protein levels of Warburg-effect-related protein hexokinase 2 (HK2) and apoptosis-related proteins Bcl-2 or Bax in transferred Saos-2 and HOS cells were detected via Western blot assay.

RESULTS

The levels of FEZF1-AS1 and CXCR4 were strikingly up-regulated, and miR-144 was notably down-regulated in OS tissues and cells. DIANA tools online database exhibited that miR-144 was a direct target of FEZF1-AS1 and CXCR4 was a direct target of miR-144. Then the interactions were validated by dual-luciferase reporter assay and RIP assay. Functionally, FEZF1-AS1 silencing or miR-144 overexpression inhibited cell viability, the glucose and lactate productions and promoted cell apoptosis in Saos-2 and HOS cells. Furthermore, miR-144 inhibitor mitigated the inhibitory effects on cell viability, the glucose and lactate productions and the promoted effect on cell apoptosis rate in Saos-2 and HOS cells induced by FEZF1-AS1 depletion. Mechanistically, FEZF1-AS1 regulated CXCR4 in Saos-2 and HOS cells by sponging miR-144.

CONCLUSION

We verified that FEZF1-AS1, CXCR4 were up-regulated, and miR-144 was downregulated in OS tissues and cells. Furthermore, FEZF1-AS1 promoted cell proliferation, Warburg effect and suppressed cell apoptosis in osteosarcoma via miR-144/CXCR4 axis, this novel pathway may provide a basis for the further study of osteosarcoma.

LncRNA FEZF1-AS1 Sponges miR-34a to Upregulate Notch-1 in Glioblastoma

Introduction

LncRNA FEZF1-AS1 has been reported to be an oncogene in many types of cancer, while its role in glioblastoma (GBM) is unknown. This study aimed to investigate the potential involvement of FEZF1-AS1 in GBM.

Methods

FEZF1-AS1 expression in paired GBM and non-tumor tissues from GBM patients was determined by RT-qPCR. A 2-year follow-up was performed to analyze the prognostic value of FEZF1-AS1 for GBM. Cell transfections were performed to analyze the interactions between FEZF1-AS1, miR-34a and Notch-1. Transwell assay was performed to analyze the role of FEZF1-AS1, miR-34a and Notch-1 in regulating GBM cell invasion and migration.

Results

In this study, analysis of TCGA dataset revealed the upregulation of FEZF1-AS1 in GBM, and the overexpression of FEZF1-AS1 in GBM was further confirmed using GBM tissues from GBM patients included in this study. High levels of FEZF1-AS1 were correlated with poor survival. FEZF1-AS1 was predicted to form base pairing with miR-34a. However, overexpression of FEZF1-AS1 and miR-34a failed to affect the expression of each other. However, upregulation of Notch-1, a target of miR-34a, was observed after FEZF1-AS1 in GBM cells. Moreover, increased invasion and migration rates of GBM cells were observed after FEZF1-AS1 and Notch-1 overexpression. MiR-34a played an opposite role and reduced the effects of FEZF1-AS1 and Notch-1 overexpression.

Conclusion

FEZF1-AS1 may sponge miR-34a to upregulate Notch-1 in GBM, thereby promoting cancer cell invasion and migration.

LncRNA CACS15 accelerates the malignant progression of ovarian cancer through stimulating EZH2-induced inhibition of APC

To elucidate the potential function of lncRNA CACS15 in the progression of ovarian cancer (OC) and its underlying mechanism. CACS15 level in OC tissues and cell lines was determined by qRT-PCR. Correlation between CACS15 level and survival of OC patients was analyzed through Kaplan-Meier method. Regulatory effects of CACS15 on cellular behaviors of OC cells were evaluated through CCK-8 and Transwell assay. Subsequently, RIP and RNA pull-down were performed to uncover the interaction between CACS15 and EZH2. Through ChIP assay, the interaction between EZH2 and APC was illustrated. A series of rescue experiments were finally conducted to elucidate the role of CACS15/APC axis in the malignant progression of OC. CACS15 was upregulated in OC tissues and cell lines relative to matched ones. High-level of CACS15 predicted worse survival in OC patients. Knockdown of CACS15 attenuated proliferative, migratory and invasive abilities of OC cells. CACS15 was mainly distributed in cytoplasm of OC cells, which was interacted with EZH2 at post-transcriptional level. Knockdown of CACS15 reduced the occupancies of EZH2 and H3K27me3 in APC promoter regions. Notably, knockdown of APC could reverse the regulatory effect of CACS15 on cellular behaviors of OC cells. LncRNA CACS15 inhibits the expression of APC by recruiting EZH2, thus accelerating the progression of ovarian cancer as an oncogene.

LINC00346 promotes hepatocellular carcinoma progression via activating the JAK-STAT3 signaling pathway

Hepatocellular carcinoma (HCC) remains the most common malignant tumor worldwide. Long noncoding RNAs can modulate various tumorigenic processes. In addition, growing evidence has indicated tha the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway is activated in multiple cancers, including HCC. Recently, it was found that LINC00346 can participate in several cancers. Nevertheless, the biological roles of LINC00346 in HCC have been barely investigated. In this study, the function of LINC00346 was specifically concentrated upon. We observed that LINC00346 was obviously elevated in HCC cells (Bel7404, Huh-6, HepG2, and QGY-7703 cells). Then, Bel7404 and HepG2 cells were overexpressed with LINC00346. Overexpression of LINC00346 repressed HCC cell survival and cell proliferation. In addition, apoptosis of Bel7404 and HepG2 cells was triggered by LINC00346 upregulation. Bel7404 and HepG2 cell cycle was arrested in the G1 phase by LINC00346. Meanwhile, we conducted wound-healing assay and Transwell invasion assays. As shown, we observed that the migratory and invasive capacities of Bel7404 and HepG2 cells were remarkably restrained by the increase of LINC00346. Moreover, we showed that LINC00346 overexpression activated the JAK-STAT3 pathway, which is involved in many cancers. Afterward, in vivo experiments were utilized and we proved that LINC00346 was able to induce HCC tumor growth via activating the JAK-STAT3 pathway. To conclude, we revealed the potential possibility of developing LINC00346 as an indicator for HCC.

Long noncoding RNA FEZF1-AS1 in human cancers

Long noncoding RNAs (lncRNAs) have been shown to play key roles in various human tumors. Ectopic expression of the lncRNA FEZ finger zinc 1 antisense 1 (FEZF1-AS1) have been reported in different cancers, including colorectal cancer, gastric neoplasia, hepatocellular carcinoma and so on. Summarizing all literature correlated with FEZF1-AS1, it is obvious that FEZF1-AS1 is mainly involved in tumorigenesis and progression through competing endogenous RNA (ceRNA) which sponges tumor-suppressive microRNA (miRNA) and recruiting mechanism. Moreover, the aberrant expression of FEZF1-AS1 is related to clinical features of patients with cancers, and regulates cellular proliferation, anti-apoptosis, invasion and metastasis through diverse underlying mechanisms. The role of FEZF1-AS1 in carcinogenesis and progression suggests that it may be a potential diagnostic biomarker or a novel therapeutic target for cancers.

FEZF1-AS1: a novel vital oncogenic lncRNA in multiple human malignancies

Long noncoding RNAs (LncRNAs) refer to the RNA with a length of >200 nucleotides, which lack or have no open reading coding frame and have higher tissue and organ specificity compared with the protein coding genes. A surging number of studies have shown that lncRNA is involved in numerous essential regulatory processes, such as X chromosome silencing, genomic imprinting, chromatin modification, transcriptional activation, transcriptional interference and nuclear transport, which are closely related to the occurrence and development of human malignancies. FEZ family Zinc Finger 1-Antisense RNA 1 (FEZF1-AS1) of FEZ family is a recently discovered lncRNA. FEZF1-AS1 is highly expressed in pancreatic cancer, colorectal cancer, lung adenocarcinoma and other human malignancies, and is associated with poor prognosis. As an oncogene, it plays crucial role in the proliferation, migration, invasion and Warburg effect of various tumor cells. In addition, FEZF1-AS1 is also involved in the regulation of multiple signal pathways such as epithelial–mesenchymal transition (EMT), signal transducer and activator of transcription 3 (STAT3) and Wnt/ β-catenin. In this paper, the recent research progress of FEZF1-AS1 in tumorigenesis and development is reviewed systematically.

Prognostic value of lncRNA FEZF1 antisense RNA 1 over-expression in oncologic outcomes of patients with solid tumors

BACKGROUND

FEZ family zinc finger 1 antisense RNA 1 (FEZF1-AS1), as a novel lncRNA, was reported to be up-regulated in various cancers and involved in tumor progression. This study systematically assessed the prognostic value of FEZF1-AS1 in solid tumors.

METHODS

Web of Science, PubMed, EMBASE, Chinese National Knowledge Infrastructure, and Wanfang databases were searched for eligible studies that evaluated the prognostic role of FEZF1-AS1 expression in cancer patients. Pooled hazard ratios (HRs) and combined odds ratios (ORs) with their 95% confidence intervals (CIs) were calculated. The meta-analysis was conducted using Stata/SE 14.1.

RESULTS

Fifteen original studies involving 1378 patients were enrolled. Pooled results showed that increased expression of FEZF1-AS1 significantly correlated with shorter overall survival (OS) in cancer patients (HR 2.04, 95% CI 1.60-2.47), and also shorter disease-free survival (DFS) (HR 2.08, 95% CI 1.27-2.89). Additionally, the combined ORs indicated that increased FEZF1-AS1 expression was significantly associated with lymph node metastasis (OR 3.35, 95% CI 1.98-5.67), distant metastasis (OR 3.10, 95% CI 1.86-5.15), poor tumor differentiation (OR 2.90, 95% CI 1.45-5.80), high depth of tumor invasion (OR 2.72, 95% CI 1.36-5.43), and advanced clinical stage (OR 2.76, 95% CI 1.75-4.35). Expression analysis using the Gene Expression Profiling Interactive Analysis database indicated that the expression of FEZF1-AS1 was higher in tumor tissues than that in the corresponding normal tissues. The results of survival analysis revealed that increased FEZF1-AS1 expression was correlated with poor OS and DFS in cancer patients.

CONCLUSIONS

LncRNA FEZF1-AS1 may serve as a valuable prognostic biomarker for clinical outcomes in various solid tumors.

FEZF1-AS1 functions as an oncogenic lncRNA in retinoblastoma

Long non-coding RNA (lncRNA) FEZF1 antisense RNA 1 (FEZF1-AS1) has been shown to be up-regulated in tumor tissues and cells, and exerts oncogenic effects on various types of malignancies. However, the expression and function of FEZF1-AS1 was still fully unclear in retinoblastoma. The purpose of our study was to investigate the expression and clinical value of FEZF1-AS1 in retinoblastoma patients, and explore the effect of FEZF1-AS1 on retinoblastoma cell proliferation, migration and invasion. In our results, levels of FEZF1-AS1 expression were elevated in retinoblastoma tissue specimens and cell lines compared with adjacent normal retina tissue specimens and human retinal pigment epithelial cell line, respectively. The correlation analysis indicated that high FEZF1-AS1 expression was significantly correlated with present choroidal invasion and optic nerve invasion. Survival analysis suggested that retinoblastoma patients in high FEZF1-AS1 expression group had obviously short disease-free survival (DFS) compared with retinoblastoma patients in low FEZF1-AS1 expression group, and high FEZF1-AS1 expression was an independent unfavorable prognostic factor for DFS in retinoblastoma patients. Loss-of-function study indicated silencing FEZF1-AS1 expression inhibited retinoblastoma cell proliferation, invasion and migration. In conclusion, FEZF1-AS1 functions as an oncogenic lncRNA in retinoblastoma.