The long non-coding RNA MALAT1 interacted with miR-218 modulates choriocarcinoma growth by targeting Fbxw8

Pivotal Role of FBXW4 in Glioma Progression and Prognosis

Backgrounds

Glioma stands as one of the most formidable brain tumor types, with patient outcomes remaining bleak even in the face of advancements in treatment modalities. FBXW4, a constituent of the F-box and WD repeat domain-containing protein family, is recognized for its participation in diverse cellular activities, including those related to tumor dynamics. Yet, the therapeutic relevance and specific role of FBXW4 in the context of glioma are not well defined. This study aims to elucidate the functional dynamics and significance of FBXW4 in glioma cases.

Methods

This research undertook a comprehensive analysis of FBXW4's expression patterns and clinical relevance in glioma by harnessing data from the TCGA and GTEx databases.

Results

The investigation revealed a distinct downregulation of FBXW4 in glioma tissues compared to normal brain counterparts, with a pronounced correlation between FBXW4 levels and disease severity. Intriguingly, FBXW4 expression inversely related to WHO tumor grades, with the most advanced grade IV gliomas exhibiting the lowest FBXW4 levels, whereas grade II tumors demonstrated the highest. Cases presenting with IDH1/2 mutations or 1p/19q codeletions were also associated with elevated FBXW4 levels. Furthermore, diminished FBXW4 expression aligned with an increased risk of mortality.

Conclusions

The findings suggest that FBXW4 holds promise as a prognostic marker and a potential therapeutic avenue in glioma management. Nonetheless, future research is imperative to decode the intricate signaling pathways involving FBXW4 and to understand its broader clinical ramifications in glioma treatment paradigms.

MALAT1: A Long Non-Coding RNA with Multiple Functions and Its Role in Processes Associated with Fat Deposition

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) belongs to the lncRNA molecules, which are involved in transcriptional and epigenetic regulation and the control of gene expression, including the mechanism of chromatin remodeling. MALAT1 was first discovered during carcinogenesis in lung adenocarcinoma, hence its name. In humans, 66 of its isoforms have been identified, and in pigs, only 2 are predicted, for which information is available in Ensembl databases (Ensembl Release 111). MALAT1 is expressed in numerous tissues, including adipose, adrenal gland, heart, kidney, liver, ovary, pancreas, sigmoid colon, small intestine, spleen, and testis. MALAT1, as an lncRNA, shows a wide range of functions. It is involved in the regulation of the cell cycle, where it has pro-proliferative effects and high cellular levels during the G1/S and mitotic (M) phases. Moreover, it is involved in invasion, metastasis, and angiogenesis, and it has a crucial function in alternative splicing during carcinogenesis. In addition, MALAT1 plays a significant role in the processes of fat deposition and adipogenesis. The human adipose tissue stem cells, during differentiation into adipocytes, secrete MALAT1 as one the most abundant lncRNAs in the exosomes. MALAT1 expression in fat tissue is positively correlated with adipogenic FABP4 and LPL. This lncRNA is involved in the regulation of PPARγ at the transcription stage, fatty acid metabolism, and insulin signaling. The wide range of MALAT1 functions makes it an interesting target in studies searching for drugs to prevent obesity development in humans. In turn, in farm animals, it can be a source of selection markers to control the fat tissue content.

Structure-based drug design of potential inhibitors of FBXW8, the substrate recognition component of Cullin-RING ligase 7

FBXW8 plays an irreplaceable role in the substrate recognition of ubiquitin-dependent proteolysis, which further regulates cell cycle progression and signal transduction. However, the abnormal expression of FBXW8 triggers malignancy, inflammation, and autophagy irregulation. FBXW8 is considered as an effective therapeutic target for Cullin-RING ligase 7 (CRL7)-related cancers. Still, the lack of selective inhibitors hinders further therapeutic development and limits the exploration of its biological mechanism. This study constructed an integrated protocol that combines pharmacophore modeling, structure-based virtual screening, and Molecular Dynamic Simulation. It was then used as a screening query to identify hit compounds targeted at the substrate recognition site of FBXW8 from a large-scale compound database including 120 million compounds. Then, ten lead compounds were retrieved by using molecular docking analysis and ADMET prediction. Finally, MD simulations were performed to validate the binding stability of selected drug candidates. The result indicated that three newly obtained compounds, namely ZINC96179876, ZINC72174069, and ZINC97730272, might be potent FBXW8 inhibitors against CRL7-related cancers such as endometrial cancer.

Biological and therapeutic viewpoints towards role of miR-218 in human cancers: Revisiting molecular interactions and future clinical translations

Understanding the exact pathogenesis of cancer is difficult due to heterogenous nature of tumor cells and multiple factors that cause its initiation and development. Treatment of cancer is mainly based on surgical resection, chemotherapy, radiotherapy and their combination, while gene therapy has been emerged as a new kind of therapy for cancer. Post-transcriptional regulation of genes has been of interest in recent years and among various types of epigenetic factors that can modulate gene expression, short non-coding RNAs known as microRNAs (miRNAs) have obtained much attention. The stability of mRNA decreases by miRNAs to repress gene expression. miRNAs can regulate tumor malignancy and biological behavior of cancer cells and understanding their function in tumorigenesis can pave the way towards developing new therapeutics in future. One of the new emerging miRNAs in cancer therapy is miR-218 that increasing evidence highlights its anti-cancer activity, while a few studies demonstrate its oncogenic function. The miR-218 transfection is promising in reducing progression of tumor cells. miR-218 shows interactions with molecular mechanisms including apoptosis, autophagy, glycolysis and EMT, and the interaction is different. miR-218 induces apoptosis, while it suppresses glycolysis, cytoprotective autophagy and EMT. Low expression of miR-218 can result in development of chemoresistance and radio-resistance in tumor cells and direct targeting of miR-218 as a key player is promising in cancer therapy. LncRNAs and circRNAs are nonprotein coding transcripts that can regulate miR-218 expression in human cancers. Moreover, low expression level of miR-218 can be observed in human cancers such as brain, gastrointestinal and urological cancers that mediate poor prognosis and low survival rate.

The functions of long noncoding RNAs on regulation of F-box proteins in tumorigenesis and progression

Accumulated evidence has revealed that F-box protein, a subunit of SCF E3 ubiquitin ligase complexes, participates in carcinogenesis and tumor progression via targeting its substrates for ubiquitination and degradation. F-box proteins could be regulated by cellular signaling pathways and noncoding RNAs in tumorigenesis. Long noncoding RNA (lncRNA), one type of noncoding RNAs, has been identified to modulate the expression of F-box proteins and contribute to oncogenesis. In this review, we summarize the role and mechanisms of multiple lncRNAs in regulating F-box proteins in tumorigenesis, including lncRNAs SLC7A11-AS1, MT1JP, TUG1, FER1L4, TTN-AS1, CASC2, MALAT1, TINCR, PCGEM1, linc01436, linc00494, GATA6-AS1, and ODIR1. Moreover, we discuss that targeting these lncRNAs could be helpful for treating cancer via modulating F-box protein expression. We hope our review can stimulate the research on exploration of molecular insight into how F-box proteins are governed in carcinogenesis. Therefore, modulation of lncRNAs is a potential therapeutic strategy for cancer therapy via regulation of F-box proteins.

VEGF-B targeting by aryl hydrocarbon receptor mediates the migration and invasion of choriocarcinoma stem-like cells

Unlike other members of the VEGF family, the function of VEGF-B in tumor progression remains to be elucidated. Thus, the present study aimed to determine the function of VEGF-B in human choriocarcinoma cells by investigating its detailed effects and molecular mechanisms. VEGF-B and aryl hydrocarbon receptor (AhR) expression were evaluated by reverse transcription-quantitative PCR analysis and western blot analysis in JEG-3 cells and choriocarcinoma stem-like cells (CSLCs) and their proliferation, migration, and invasion after the transfection of short hairpin RNA VEGF-B, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; AhR agonist) treatment or StemRegenin 1 (SR1; AhR antagonist) treatment were examined by cell proliferation assay, wound healing assay and Transwell assay. In addition, luciferase reporter analysis and bioinformatics data mining were used to investigate the association between VEGF-B and AhR. Upregulation of VEGF-B and AhR expression was observed in CSLCs. Following VEGF-B knockdown or SR1 treatment, the proliferative, migratory, and invasive abilities of CSLCs were significantly decreased, contrary to the findings after TCDD treatment. It was also found that AhR enhanced VEGF-B transcriptional activity by binding to the relative promoter region. These observations indicated that VEGF-B may be an oncogene that promotes choriocarcinoma cell migration and invasion targeted by AhR. Therefore, targeting VEGF-B may provide a novel therapeutic opportunity for choriocarcinoma.

The Role of Long Non-Coding RNAs (lncRNAs) in Female Oriented Cancers

Recent advances in molecular biology have discovered the mysterious role of long non-coding RNAs (lncRNAs) as potential biomarkers for cancer diagnosis and targets for advanced cancer therapy. Studies have shown that lncRNAs take part in the incidence and development of cancers in humans. However, previously they were considered as mere RNA noise or transcription byproducts lacking any biological function. In this article, we present a summary of the progress on ascertaining the biological functions of five lncRNAs (HOTAIR, NEAT1, H19, MALAT1, and MEG3) in female-oriented cancers, including breast and gynecological cancers, with the perspective of carcinogenesis, cancer proliferation, and metastasis. We provide the current state of knowledge from the past five years of the literature to discuss the clinical importance of such lncRNAs as therapeutic targets or early diagnostic biomarkers. We reviewed the consequences, either oncogenic or tumor-suppressing features, of their aberrant expression in female-oriented cancers. We tried to explain the established mechanism by which they regulate cancer proliferation and metastasis by competing with miRNAs and other mechanisms involved via regulating genes and signaling pathways. In addition, we revealed the association between stated lncRNAs and chemo-resistance or radio-resistance and their potential clinical applications and future perspectives.

Ropivacaine Retards the Viability, Migration, and Invasion of Choriocarcinoma Cells by Regulating the Long Noncoding RNA OGFRP1/MicroRNA-4731-5p/HIF3A Axis

Choriocarcinoma is an aggressive gestational trophoblastic neoplasm. This study attempted to explore the biological functions and underlying mechanisms by which ropivacaine restrains the progression of choriocarcinoma. The expression of long noncoding RNA OGFRP1, microRNA-4731-5p (miR-4731-5p), and HIF3A in choriocarcinoma cells was assessed by qRT-PCR. Choriocarcinoma cells treated with ropivacaine at the concentration of 100, 500, and 1000 μM were cultured for 24, 48, and 72 h, respectively. Choriocarcinoma cell viability was evaluated by MTT assay. Transwell assay was conducted to examine choriocarcinoma cell migration and invasion. Additionally, the target relationship between OGFRP1 and miR-4731-5p or between miR-4731-5p and HIF3A was predicted by bioinformatics analysis and confirmed by dual-luciferase reporter assays. OGFRP1 and HIF3A expression were enhanced in choriocarcinoma cells, while miR-4731-5p expression was inhibited. Treatment with ropivacaine impeded choriocarcinoma cell viability, migration, and invasion. Choriocarcinoma cells treated with 1000 μM ropivacaine for 48 h were selected for subsequent experiments. OGFRP1 elevation or miR-4731-5p deficiency mitigated the reduction effect of ropivacaine on tumorigenesis of choriocarcinoma cells. Besides, miR-4731-5p was predicted as the potential OGFRP1 target by StarBase and LncBase, and HIF3A was predicted as the potential miR-4731-5p target by StarBase and TargetScan. Dual-luciferase reporter assays determined that miR-4731-5p was a target of OGFRP1 and HIF3A was a target of miR-4731-5p. Feedback experiments declared that miR-4731-5p elevation or HIF3A suppression reversed the promoting effect of OGFRP1 overexpression on the malignant behaviors of ropivacaine-treated choriocarcinoma cells. Ropivacaine constrained choriocarcinoma cell viability, migration, and invasion through modulating the OGFRP1/miR-4731-5p/HIF3A axis. Our study may provide a novel strategy for choriocarcinoma prevention and treatment.

(In)Distinctive Role of Long Non-Coding RNAs in Common and Rare Ovarian Cancers

Rare ovarian cancers (ROCs) are OCs with an annual incidence of fewer than 6 cases per 100,000 women. They affect women of all ages, but due to their low incidence and the potential clinical inexperience in management, there can be a delay in diagnosis, leading to a poor prognosis. The underlying causes for these tumors are varied, but generally, the tumors arise due to alterations in gene/protein expression in cellular processes that regulate normal proliferation and its checkpoints. Dysregulation of the cellular processes that lead to cancer includes gene mutations, epimutations, non-coding RNA (ncRNA) regulation, posttranscriptional and posttranslational modifications. Long non-coding RNA (lncRNA) are defined as transcribed RNA molecules, more than 200 nucleotides in length which are not translated into proteins. They regulate gene expression through several mechanisms and therefore add another level of complexity to the regulatory mechanisms affecting tumor development. Since few studies have been performed on ROCs, in this review we summarize the mechanisms of action of lncRNA in OC, with an emphasis on ROCs.

Integrated Bioinformatic Analysis of Competing Endogenous RNA Network of Choriocarcinoma

Background

Numerous studies have demonstrated that noncoding RNAs are involved in choriocarcinoma (CC). The competing endogenous RNA (ceRNA) network plays an important role in the occurrence and development of carcinoma. However, the involvement of the ceRNA network in CC remains unclear. The current study aimed to investigate the regulatory mechanism of ceRNA in CC.

Material/Methods

We downloaded the messenger RNAs (mRNAs) expression profiles (GSE20510 and GSE65654) and microRNAs (miRNAs) expression profiles (GSE32346 and GSE130489) from GEO datasets. The limma package of R software was used to identify differentially expressed RNAs (DERNAs). Then, we performed functional annotation of the differentially expressed mRNAs (DEmRNAs). TargetScan, miRDB, miRWalk, and Starbase were used to construct a CC-specific ceRNA network and select key molecules.

Results

The results identified a total of 177 DEmRNAs and 189 differentially expressed miRNAs (DEmiRNAs) between the trophoblast and CC cell line samples. Ten differentially expressed lncRNAs (DElncRNAs) were obtained based on experimental studies. The DEmRNAs were mainly enriched in cell proliferation, positive regulation of the apoptotic process, and cell death. A total of 10 genes were ascertained as hub genes. Based on DEmRNAs, DEmiRNAs, and DElncRNAs, a CC-specific ceRNA network was established. Five DElncRNAs, 15 DEmiRNAs, and 45 DEmRNAs were identified. In addition, LINC00261, MEG3, MALAT1, H19, and OGFRP1 were identified as 5 key lncRNAs in choriocarcinoma.

Conclusions

This study provides novel insights into CC mechanisms and identified potential therapeutic targets for CC.

An Overview of the Role of Long Non-Coding RNAs in Human Choriocarcinoma

Choriocarcinoma (CC), a subtype of trophoblastic disease, is a rare and highly aggressive neoplasm. There are two main CC subtypes: gestational and non-gestational, (so called when it develops as a component of a germ cell tumor or is related to a somatic mutation of a poorly differentiated carcinoma), each with very diverse biological activity. A therapeutic approach is highly effective in patients with early-stage CC. The advanced stage of the disease also has a good prognosis with around 95% of patients cured following chemotherapy. However, advancements in diagnosis and treatment are always needed to improve outcomes for patients with CC. Long non-coding (lnc) RNAs are non-coding transcripts that are longer than 200 nucleotides. LncRNAs can act as oncogenes or tumor suppressor genes. Deregulation of their expression has a key role in tumor development, angiogenesis, differentiation, migration, apoptosis, and proliferation. Furthermore, detection of cancer-associated lncRNAs in body fluids, such as blood, saliva, and urine of cancer patients, is emerging as a novel method for cancer diagnosis. Although there is evidence for the potential role of lncRNAs in a number of cancers of the female genital tract, their role in CC is poorly understood. This review summarizes the current knowledge of lncRNAs in gestational CC and how this may be applied to future therapeutic strategies in the treatment of this rare cancer.

MALAT1: A Promising Therapeutic Target for the Treatment of Metastatic Colorectal Cancer

Cancer metastasis research has emerged in recent years as one of the most important topics of debate in the discovery and development of novel anticancer therapies. Colorectal cancer (CRC), the third most common cancer worldwide, has a high mortality rate due to recurrence and distant metastasis to the liver. Several non-coding RNAs (ncRNAs) have been linked to metastatic CRC (mCRC), including the long non-coding RNA (lncRNA) Metastasis-Associated Lung-Adenocarcinoma Transcript 1 (MALAT1). MALAT1 is an RNA that has been linked to tumor cell proliferation, progression, epithelial-mesenchymal transition (EMT), cell migration and invasion, metastasis, and survival in mammalian species. Previously, there was no convincing evidence linking MALAT1 to mCRC. Studies have shown that MALAT1 functions as a competitive endogenous RNA (ceRNA) with microRNAs (miRNAs) and interacts directly with oncogenes and proteins. This RNA also activates several signaling pathways, including Wnt/β-catenin, PI3K/Akt/mTOR, and EMT. Meanwhile, standard chemotherapy and immunotherapy are the current treatment options for mCRC patients. However, evidence-based studies have recently demonstrated that inhibiting the MALAT1 RNA transcript can be considered as a treatment option for mCRC, highlighting the need to investigate its roles as a therapeutic target in mCRC. Thus, in this review, we looked at studies that linked MALAT1 to multiple signaling pathways implicated in mCRC, as well as its potential as a therapeutic target for the treatment of mCRC.

si-MALAT1 attenuates thymic cancer cell proliferation and promotes apoptosis via the miR-145-5p/HMGA2 pathway

Metastasis-associated-lung-adenocarcinoma-transcript-1 (MALAT1) is a long non-coding RNA that is considered a potential tumor marker. The present study aimed to investigate the effect and mechanism of MALAT1 on cell proliferation and apoptosis in thymic cancer cells. IU-TAB-1, A549, HCT-116 and 293T cells were screened by reverse transcription-quantitative PCR to assess high-mobility group AT-hook 2 (HMGA2) expression in various types of cancer cells and were transfected with small interfering (si)RNA targeting MALAT1 (si-MALAT1). Cell proliferation was evaluated by Cell Counting Kit-8 assay. Cell apoptosis and cell cycle were examined using flow cytometry. The protein expression of cyclin D1, cyclin E, Bax, Bcl-2 and HMGA2 was determined by western blot analysis, while the associations between MALAT1 and microRNA (miR)-145-5p and between HMGA2 and miR-145-5p were determined by luciferase reporter assay. Among the four cell lines evaluated, IU-TAB-1 showed the highest expression of MALAT1; thus, IU-TAB-1 cells were selected for subsequent experiments. Compared with the findings in the control group, si-MALAT1 significantly decreased the cell proliferation of IU-TAB-1 cells, whereas the apoptosis levels and number of cells in G₂ phase were increased. The protein expression levels of cyclin D1, cyclin E, Bcl-2 and HMGA2 were significantly decreased in the si-MALAT1 group compared with those in the control group, while Bax levels were significantly increased. After treatment with si-MALAT1 in combination with miR-145-5p mimics or inhibitors, cell proliferation and apoptosis were respectively enhanced and inhibited in IU-TAB-1 cells. miR-145-5p inhibited the luciferase activity of IU-TAB-1 cells transfected with the MALAT1 or HMGA2 3' untranslated region. In conclusion, si-MALAT1 significantly attenuated cell proliferation and apoptosis via the miR-145-5p/HMGA2 pathway in thymic cancer cells.

uc.77- Downregulation Promotes Colorectal Cancer Cell Proliferation by Inhibiting FBXW8-Mediated CDK4 Protein Degradation

Transcribed ultraconserved regions (T-UCRs) are a new type of long non-coding RNA, and the UCR has 481 segments longer than 200 base pairs that are 100% conserved between humans, rats, and mice. T-UCRs involved in colorectal cancer (CRC) have not been studied in detail. We performed T-UCR microarray analysis and found that uc.77- was significantly downregulated in CRC tissues and cell lines. Ectopic expression of uc.77- significantly inhibited the proliferation of CRC cells in vitro and the growth of xenograft tumors in nude mice in vivo. Mechanistic studies showed that uc.77- competed with FBXW8 mRNA for binding to microRNA (miR)-4676-5p through a competing endogenous RNA mechanism and inhibited the proliferation of CRC cells by negatively regulating CDK4. The present findings highlight the role of the uc.77-/miR-4676-5p/FBXW8 axis in CRC and identify uc.77- as a potential novel target for the treatment of CRC.

Reflections on the Role of Malat1 in Gynecological Cancer

Non-coding RNAs (ncRNAs) have received significant attention over the last few years. Malat1, as one of the most extensively studied ncRNAs, is believed to be not only a potential biomarker for disease diagnosis and prognosis, but also a candidate drug target for gynecological cancers. This potential is supported by a growing body of experimental evidence demonstrating that Malat1 participates in the occurrence, progression, and metastasis of tumors. Research has also shown that Malat1 can influence patient survival by regulating a range of target genes and signaling pathways. However, previous review articles have generally failed to consider the role of Malat1 in gynecological cancer in detail. In the present review, we summarize recent progress in research relating to the clinical relevance of Malat1 and the molecular mechanisms underlying the action of this ncRNA. Besides, we put forward some action points for further research after taking into consideration the sub-location and other essential properties of Malat1, which might enable us to have a better understanding of the potential of this molecule regarding clinical diagnosis and treatment.

Long non-coding RNAs in ovarian cancer: expression profile and functional spectrum

Long non-coding RNAs (lncRNAs), initially recognized as byproducts of the transcription process, have been proven to play crucial modulatory roles in preserving overall homoeostasis of cells and tissues. Furthermore, aberrant levels of these transcripts have been shown to contribute many diseases, including cancer. Among these, many aspects of ovarian cancer biology have been found to be regulated by lncRNAs, including cancer initiation, progression and dissemination. In this review, we summarize recent studies to highlight the various roles of lncRNAs in ovary in normal and pathological conditions, immune system, diagnosis, prognosis, and therapy. We address lncRNAs that have been extensively studied in ovarian cancer and their contribution to cellular dynamics.

Knockdown of lncRNA OGFRP1 Inhibits Proliferation and Invasion of JEG-3 Cells Via AKT/mTOR Pathway

Increasing evidence indicates the pivotal role of long noncoding RNAs in a variety of cancers, but there is limited focus on the link between long noncoding RNAs and gestational choriocarcinoma. This study aimed to examine the role of long noncoding RNA OGFRP1 in JEG-3 and JAR cells. Small interfering RNA was used to downregulate long noncoding RNA OGFRP1 level. Cell proliferation was measured by cell counting kit-8 and clone formation assays. Cell cycle and apoptosis were analyzed by flow cytometry. Cell invasion was examined by transwell assay. Protein expression was determined by Western blot. A double-effect inhibitor (BEZ235) that inhibits AKT and mTOR phosphorylation was used as a positive control. Knockdown of long noncoding RNA OGFRP1 significantly inhibited the proliferation of JEG-3 and JAR cells. Knockdown of long noncoding RNA OGFRP1 induced cell cycle arrest in G1 phase and apoptosis. On the other hand, knockdown of long noncoding RNA OGFRP1 inhibited the invasion of JEG-3 and JAR cells. Finally, knockdown of long noncoding RNA OGFRP1 resulted in the inactivation of AKT/mTOR signaling pathway. In addition, knockdown of long noncoding RNA OGFRP1 caused changes in the expression of intracellular cell cycle–related proteins and apoptosis-related proteins, including downregulation of CDK4, CDK6, Cyclin D1, Nusap1, and Bcl2 protein expression and upregulation of Bax protein expression. In conclusion, we found that downregulation of long noncoding RNA OGFRP1 inhibited cell proliferation, cell cycle progression, and invasion of JEG-3 and JAR cells and induced apoptosis through AKT/mTOR pathway. This study extends the understanding of the function of long noncoding RNA OGFRP1 in tumorigenesis, and these findings may be important for developing a potential therapeutic target for gestational choriocarcinoma therapy.

ADAM12 silencing promotes cellular apoptosis by activating autophagy in choriocarcinoma cells

ADAM metallopeptidase domain 12 (ADAM12) has been demonstrated to mediate cell proliferation and apoptosis resistance in several types of cancer cells. However, the effect of ADAM12 silencing on the proliferation and apoptosis of choriocarcinoma cells remains unknown. The present study revealed that ADAM12 silencing significantly inhibited cellular activity and proliferation in the human choriocarcinoma JEG3 cell line and increased the rate of apoptosis. In addition, ADAM12 silencing significantly increased the expression levels of the autophagy proteins microtubule-associated protein-light-chain 3 (LC3B) and autophagy related 5 (ATG5) and the fluorescence density of LC3B in JEG-3 cells. However, the suppression of autophagy by 3-methyladenine could block ADAM12 silencing-induced cellular apoptosis. ADAM12 silencing reduced the levels of the inflammatory factors interleukin-1β, interferon-γ and TNF-α, and inactivated nuclear p65-NF-κB and p-mTOR in JEG-3 cells. The downregulation of p-mTOR expression by ADAM12 silencing was rescued in 3-methyladenine-treated JEG-3 cells, indicating that mTOR might participate in the autophagy-mediated pro-apoptotic effect of ADAM12 silencing. In conclusion, ADAM12 silencing promoted cellular apoptosis in human choriocarcinoma JEG3 cells, which might be associated with autophagy and the mTOR response. These findings indicate that ADAM12 silencing might be a potential novel therapeutic target for choriocarcinoma.

R-spondin3 promotes the tumor growth of choriocarcinoma JEG-3 cells

R-spondin3 (RSPO3), an activator of Wnt/β-catenin signaling, plays a key role in tumorigenesis of various cancers, but its role in choriocarcinoma remains unknown. To investigate the effect of RSPO3 on the tumor growth of choriocarcinoma JEG-3 cells, the expression of RSPO3 in human term placenta was detected, and a stable RSPO3-overexpressing JEG-3 cell line was established via lentivirus-mediated transduction. The expression of biomarkers involved in tumorigenicity was detected in the RSPO3-overexpressing JEG-3 cells, and cell proliferation, invasion, migration, and apoptosis were investigated. Moreover, soft agar clonogenic assays and xenograft tumorigenicity assays were performed to assess the effect of RSPO3 on tumor growth in vitro and in vivo. The results showed that RSPO3 was widely expressed in human term placenta and overexpression of RSPO3 promoted the proliferation and inhibited the migration, invasion, and apoptosis of the JEG-3 cells. Meanwhile, RSPO3 overexpression promoted tumor growth both in vivo and in vitro. Further investigation showed that the phosphorylation levels of Akt, phosphatidylinositol 3-kinase (PI3K), and ERK as well the expression of β-catenin and proliferating cell nuclear antigen (PCNA) were increased in the RSPO3-overexpressing JEG-3 cells and tumor xenograft. Taken together, these data indicate that RSPO3 promotes the tumor growth of choriocarcinoma via Akt/PI3K/ERK signaling, which supports RSPO3 as an oncogenic driver promoting the progression of choriocarcinoma.

The implication of LncRNA MALAT1 in promoting chemo-resistance of laryngeal squamous cell carcinoma cells

Background

This study was aimed to evaluate the involvement of lncRNA MALAT1 in modifying chemo‐sensitivity of laryngeal squamous cell carcinoma (LSCC) cell lines.

Methods

Totally 108 pairs of tumor tissues and matched para‐tumor normal tissues were gathered from patients who were pathologically confirmed as LSCC. Meanwhile, LSCC cell lines, including TU686, TU177, AMC‐HN‐8, and LSC‐1, were purchased to evaluate their tolerance to cisplatin, 5‐fluorouracil, paclitaxel, and vincristine. Additionally, CCK‐8 assay, flow cytometry, transwell assay, and wound healing assay were implemented to assess the part of MALAT1 in modulating viability, apoptosis, invasion, and migration of LSCC cell lines.

Results

MALAT1 expression was higher in LSCC tissues than in adjacent normal tissues (P < .05), and LSCC patients who carried highly expressed MALAT1 demonstrated poorer 5‐year survival than ones with low MALAT1 expression (P < .05). For another, expression of MALAT1 was also unusually elevated within TU686, TU177, AMC‐HN‐8, and LSC‐1 cell lines as relative to NHBEC cell line (P < .05). The TU686 cell line therein excelled in resisting the growth‐curbing effects of 5‐fluorouracil (IC50 = 20.44 μmol/L), paclitaxel (IC50 = 35.86 μg/L), and vincristine (IC50 = 0.12 μmol/L), when compared with TU177, AMC‐HN‐8, and LSC‐1 cell line (P < .05). Moreover, there seemed great potential for over‐expressed MALAT1 to enhance the chemo‐resistance of both TU686 and LSC‐1 cell lines (P < .05). Not only that, silencing of MALAT1 tended to undermine the proliferative and metastatic power of TU686 and LSC‐1 cell lines (P < .05).

Conclusion

LncRNA MALAT1 counted in triggering tolerance of LSCC against chemo‐drugs by boosting metastasis and depressing apoptosis of tumor cells.

The long non-coding RNA PCA3: an update of its functions and clinical applications as a biomarker in prostate cancer

Prostate cancer antigen 3 (PCA3) is an overexpressed prostate long non-coding RNA (lncRNA), transcribed from an intronic region at the long arm of human chromosome 9q21–22. It has been described that PCA3 modulates prostate cancer (PCa) cell survival through modulating androgen receptor (AR) signaling, besides controlling the expression of several androgen responsive and cancer-related genes, including epithelial–mesenchymal transition (EMT) markers and those regulating gene expression and cell signaling. Also, PCA3 urine levels have been successfully used as a PCa diagnostic biomarker. In this review, we have highlighted recent findings regarding PCA3, addressing its gene structure, putative applications as a biomarker, a proposed origin of this lncRNA, roles in PCa biology and expression patterns. We also updated data regarding PCA3 interactions with cancer-related miRNAs and expression in other tissues and diseases beyond the prostate. Altogether, literature data indicate aberrant expression and dysregulated activity of PCA3, suggesting PCA3 as a promising relevant target that should be even further evaluated on its applicability for PCa detection and management.

Metastasis Associated Lung Adenocarcinoma Transcript 1: An update on expression pattern and functions in carcinogenesis

The Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) is among long non-coding RNAs (lncRNAs) which has disapproved the old term of "junk DNA" which was used for majority of human genome which are not transcribed to proteins. An extensive portion of literature points to the fundamental role of this lncRNA in tumorigenesis process of diverse cancers ranging from solid tumors to leukemia. Being firstly identified in lung cancer, it has prognostic and diagnostic values in several cancer types. Consistent with the proposed oncogenic roles for this lncRNA, most of studies have shown up-regulation of MALAT1 in malignant tissues compared with non-malignant/normal tissues of the same source. However, few studies have shown down-regulation of MALAT1 in breast cancer, endometrial cancer, colorectal cancer and glioma. In the current study, we have conducted a comprehensive literature search and provided an up-date on the role of MALAT1 in cancer biology. Our investigation underscores a potential role as a diagnostic/prognostic marker and a putative therapeutic target for MALAT1.

LncRNA MALAT1/miR-181a-5p affects the proliferation and adhesion of myeloma cells via regulation of Hippo-YAP signaling pathway

Multiple myeloma (MM) is a plasma cells malignant proliferative disease, especially in aged people. LncRNAs have been considered as important regulators in MM. This research was to study the effect of LncRNA MALAT1 on the proliferation and adhesion of myeloma cells and whether Long non-coding RNAs MALAT1(LncRNA MALAT1) plays its regulative role through Hippo-YAP signaling pathway by targeting miR-181a-5p. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis was used to detect the LncRNA MALAT1/miR-181a-5p expression and improve the transfection efficiency. Western blot analysis was used to analyze the expression of proliferation and apoptosis related proteins and Hippo-Yes-associated protein (YAP) signaling pathway related proteins. Cell proliferative ability and cell apoptosis were respectively determined by Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis. ELISA assay was for the determination of adherence factors. Immunohistochemistry was to detect the expression of proliferation and adhesion related proteins. LncRNA MALAT1 targeting gene was determined by Dual-luciferase reporter assay. LncRNA MALAT1 was increased in MM cells and LncRNA MALAT1 interference could inhibit cell proliferation and promote cell apoptosis with the changes in the related proteins. Also, LncRNA MALAT1 interference could inhibit cell adhesion through Hippo-YAP signaling pathway. MiR-181a-5p was demonstrated to be a target of LncRNA MALAT1 and miR-181a-5p overexpression could also regulate the changes in cellular behavior in accordance with the LncRNA MALAT1 interference. In addition, LncRNA MALAT1 interference could decrease the expression of miR-181a-5p and inhibit the growth of tumor. In conclusion, this study showed that LncRNA MALAT1 interference inhibited the proliferation and adhesion of myeloma cells by the up-regulation of miR-181a-5p through activating the Hippo-YAP signaling pathway.

LncRNA-MALAT1 regulates proliferation and apoptosis of ovarian cancer cells by targeting miR-503-5p

Objective

Ovarian cancer (OC) is a common female disease with a poor prognosis. But the possible mechanism of OC tumor progression remains an active area of research. This study is intended to explore the effect of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on proliferation and apoptosis of OC and its mechanism.

Materials and methods

MALAT1 and miR-503-5p expressions in human OC cell lines and normal human ovarian epithelial (HOSE) cell line were measured using qRT-PCR. OC cell line SKOV3 is divided into 4 groups: pcDNA3.1 group, pcDNA3.1-MALAT1 group, si-NC group, and si-MALAT1 group. MTT assay and 5-ethynyl-2'-deoxyuridine (EdU) assay were applied for the detection of cell proliferation. Relationship of MALAT1 with miR-503-5p was verified using luciferase assay and RNA pull-down. The luciferase activity in cells was normalized to RNA concentrations determined by Bradford assays.

Results

MALAT1 expression in OC cells was elevated compared with HOSE cells. MTT assay and EdU assay supported that si-MALAT1 could inhibit cell proliferation in OC cells. Treatment of si-MALAT1 results in increased cell apoptosis rate in both SKOV3 cells and OVCAR3 cells. The expression of lncRNA-MALAT1 was negatively associated with the expression of miR-503-5p in OC cells, while luciferase assay and RNA pull-down together supported the direct binding of MALAT1 with miR-503-5p. Knockdown of MALAT1 was able to inhibit the activation of JAK2/STAT3 signal pathway, and MALAT1 overexpression was accompanied by activation of these factors.

Conclusion

lncRNA-MALAT1 can negatively target miR-503-5p expression to further promote proliferation and depress apoptosis of OC cells through the JAK2-STAT3 pathway.

Role of G protein-coupled receptor 1 in choriocarcinoma progression

Choriocarcinoma is characterized by malignant proliferation and transformation of trophoblasts and is currently treated with systemic chemotherapeutic agents. The lack of specific targets for chemotherapeutic agents results in indiscriminate drug distribution. In our study, we aimed to delineate the mechanism by which G protein-coupled receptor 1 (GPR1) regulates the development of choriocarcinoma and thus investigated GPR1 as a prospective chemotherapeutic target. In this study, GPR1 expression levels were examined in several trophoblast cell lines. We found significantly higher GPR1 expression in choriocarcinoma cells (JEG3 and BeWo) than in normal trophoblast cells (HTR-8/SVneo). Additionally, we studied the role of GPR1 in choriocarcinoma in vitro and in vivo. GPR1 knockdown suppressed proliferation, invasion, and Akt and ERK phosphorylation in vitro and slowed tumor growth in vivo. Interestingly, GPR1 overexpression promoted increased proliferation, invasion, and Akt and ERK phosphorylation in vitro. Furthermore, we identified a specific GPR1-binding seven-amino acid peptide, LRH7-G3, that might also suppress choriocarcinoma in vitro and in vivo through phage display. Our study is the first to report that GPR1 may play a role in regulating choriocarcinoma progression through the Akt and ERK pathways. GPR1 could be a promising potential pharmaceutical target for choriocarcinoma.

Survivin is a prognostic indicator in glioblastoma and may be a target of microRNA-218

Accumulating evidence has revealed that survivin expression is associated with a malignant phenotype and poor prognosis in glioma. Survivin is also a potential target of microRNA (miRNA/miR)-218. The aim of the present study was to investigate the expression and function of survivin in glioblastoma, and to examine the association between survivin and miR-218. For that purpose, survivin mRNA levels were analyzed in 144 frozen samples of glioblastoma using whole-genome RNA sequencing. In vitro cell proliferation, migration, invasion and apoptosis assays were performed, and survivin expression was detected by western blotting. The results revealed that the mRNA expression levels of survivin were negatively and significantly associated with overall survival in glioblastoma. Further in vitro analyses suggested that miR-218 may inhibit the expression of survivin. Expression of miR-218 in the LN229 cell line was significantly lower than that in the immortalized human gliocyte HEB cell line. miR-218 markedly inhibited tumor cell proliferation, migration and invasion capacities, and decreased apoptosis. miR-218 also inhibited the expression of survivin. These results indicated that survivin may be a target of miR-218 and could serve as a predictive biomarker.

Down-regulation of DANCR acts as a potential biomarker for papillary thyroid cancer diagnosis

Long non-coding RNAs (lncRNAs) have been reported to be dysregulated and play a crucial role in the progression of cancer. LncRNA DANCR has recently been revealed to be involved in tumorigenesis of numerous types of cancer, including osteosarcoma, gastric cancer, breast cancer, hepatocellular carcinoma, and colorectal cancer. However, the expression profiles and biological relevance of DANCR in papillary thyroid cancer (PTC) have not yet been reported. In the present study, the expression level of DANCR in PTC tissues and adjacent normal tissues was detected by reverse transcription-quantitative PCR in PTC patients, and then we analyzed the association with clinical pathological characteristics of patients and DANCR expressions. These results demonstrated that the expression of DANCR was notably decreased in tumor tissues in comparison with adjacent normal tissues (P<0.001). Furthermore, the present study found that DANCR expression level was correlated to T grade (P<0.01) and TNM stage (P=0.017). The present study demonstrated that DANCR was associated with PTC aggressive clinical features and may serve as a diagnostic biomarker for detecting PTC patients.

Oncogenic KSHV-encoded interferon regulatory factor upregulates HMGB2 and CMPK1 expression to promote cell invasion by disrupting a complex lncRNA-OIP5-AS1/miR-218-5p network

Kaposi's sarcoma (KS), a highly disseminated tumor of hyperproliferative spindle endothelial cells, is the most common AIDS-associated malignancy caused by infection of Kaposi's sarcoma-associated herpesvirus (KSHV). KSHV-encoded viral interferon regulatory factor 1 (vIRF1) is a viral oncogene but its role in KSHV-induced tumor invasiveness and motility remains unknown. Here, we report that vIRF1 promotes endothelial cell migration, invasion and proliferation by down-regulating miR-218-5p to relieve its suppression of downstream targets high mobility group box 2 (HMGB2) and cytidine/uridine monophosphate kinase 1 (CMPK1). Mechanistically, vIRF1 inhibits p53 function to increase the expression of DNA methyltransferase 1 (DNMT1) and DNA methylation of the promoter of pre-miR-218-1, a precursor of miR-218-5p, and increases the expression of a long non-coding RNA OIP5 antisense RNA 1 (lnc-OIP5-AS1), which acts as a competing endogenous RNA (ceRNA) of miR-218-5p to inhibit its function and reduce its stability. Moreover, lnc-OIP5-AS1 increases DNA methylation of the pre-miR-218-1 promoter. Finally, deletion of vIRF1 from the KSHV genome reduces the level of lnc-OIP5-AS1, increases the level of miR-218-5p, and inhibits KSHV-induced invasion. Together, these results define a novel complex lnc-OIP5-AS1/miR-218-5p network hijacked by vIRF1 to promote invasiveness and motility of KSHV-induced tumors.

Long noncoding RNA EZR-AS1 promotes tumor growth and metastasis by modulating Wnt/β-catenin pathway in breast cancer

Accumulating evidence has demonstrated that long noncoding RNAs (lncRNAs) serve important roles in tumor development and progression. However, whether lncRNA EZR-AS1 is associated with breast cancer (BC) progression remains unclear. In the present study, reverse transcription-quantitative polymerase chain reaction analysis demonstrated that the expression of EZR-AS1 was significantly upregulated in BC tissues and cell lines. Furthermore, Kaplan-Meier curve analysis revealed that increased EZR-AS1 expression in patients with BC contributes to poor prognosis. Cell counting kit-8 and fluorescence-activated cell sorting experiments indicated that EZR-AS1 knockdown significantly suppressed the proliferation and cell cycle progression of breast cancer cells, while reducing cellular apoptosis. Furthermore, Transwell assays suggested that EZR-AS1 knockdown reduced the migration and invasion ability of BC cells compared with control cells. In the present study, it was observed that EZR-AS1 interacts with β-catenin to prevent degradation. EZR-AS1 knockdown resulted in β-catenin downregulation and inactivation of the Wnt/β-catenin pathway. Rescue assays revealed that β-catenin overexpression reversed the effects of EZR-AS1 knockdown on BC cell proliferation, apoptosis, migration and invasion. In conclusion, the results of the present study demonstrate that EZR-AS1 serves as an oncogene in BC via activating the Wnt/β-catenin pathway. This suggests that EZR-AS1 may be a therapeutic target for BC treatment.