Long non-coding RNA Fer-1-like family member 4 is overexpressed in human glioblastoma and regulates the tumorigenicity of glioma cells

Shedding light on function of long non-coding RNAs (lncRNAs) in glioblastoma

The brain tumors and especially glioblastoma, are affecting life of many people worldwide and due to their high mortality and morbidity, their treatment is of importance and has gained attention in recent years. The abnormal expression of genes is commonly observed in GBM and long non-coding RNAs (lncRNAs) have demonstrated dysregulation in this tumor. LncRNAs have length more than 200 nucleotides and they have been located in cytoplasm and nucleus. The current review focuses on the role of lncRNAs in GBM. There two types of lncRNAs in GBM including tumor-promoting and tumor-suppressor lncRNAs and overexpression of oncogenic lncRNAs increases progression of GBM. LncRNAs can regulate proliferation, cell cycle arrest and metastasis of GBM cells. Wnt, STAT3 and EZH2 are among the molecular pathways affected by lncRNAs in GBM and for regulating metastasis of GBM cells, these RNA molecules mainly affect EMT mechanism. LncRNAs are involved in drug resistance and can induce resistance of GBM cells to temozolomide chemotherapy. Furthermore, lncRNAs stimulate radio-resistance in GBM cells. LncRNAs increase PD-1 expression to mediate immune evasion. LncRNAs can be considered as diagnostic and prognostic tools in GBM and researchers have developed signature from lncRNAs in GBM.

The role and clinical relevance of long non-coding RNAs in glioma

Glioma represents a complex and heterogeneous disease, posing significant challenges to both clinicians and researchers. Despite notable advancements in glioma treatment, the overall survival rate for most glioma patients remains dishearteningly low. Hence, there is an urgent necessity to discover novel biomarkers and therapeutic targets specifically tailored for glioma. In recent years, long non-coding RNAs (lncRNAs) have emerged as pivotal regulators of gene expression and have garnered attention for their involvement in the development and progression of various cancers, including glioma. The dysregulation of lncRNAs plays a critical role in glioma pathogenesis and influences clinical outcomes. Consequently, there is growing interest in exploring the potential of lncRNAs as diagnostic and prognostic biomarkers, as well as therapeutic targets. By understanding the functions and dysregulation of lncRNAs in glioma, researchers aim to unlock new avenues for the development of innovative treatment strategies catered to glioma patients. The identification and thorough characterization of lncRNAs hold the promise of novel therapeutic approaches that could potentially improve patient outcomes and enhance the management of glioma, ultimately striving for better prospects and enhanced quality of life for those affected by this challenging disease. The primary objective of this paper is to comprehensively review the current state of knowledge regarding lncRNA biology and their intricate roles in glioma. It also delves into the potential of lncRNAs as valuable diagnostic and prognostic indicators and explores their feasibility as promising targets for therapeutic interventions.

Expression and Alteration Value of Long Noncoding RNA AB073614 and FER1L4 in Patients with Acute Myeloid Leukemia (AML)

BACKGROUND

Numerous studies have probed the deregulation of the long noncoding RNA AB073614 and FER1L4, which have been discovered in a variety of cancers. However, the precise expression pattern of these lncRNAs and their clinical implications in acute myeloid leukemia (AML) remain elusive. Considering the involvement of the PI3K axis in AML pathogenesis, an investigation into the expression of AB073614 and FER1L4 targets of this pathway has been proposed, aiming to elucidate a potential mechanism underlying AML development.

METHODS

The expression levels of lncRNA AB073614 and FER1L4 were assessed in 30 newly diagnosed AML patients and 12 healthy individuals using quantitative reverse transcription-polymerase chain reaction techniques. A statistical analysis was conducted to determine the association of AB073614 and FER1L4 expression levels with clinicopathological features.

RESULTS

A significant upregulation of AB073614 was observed in AML patients compared to the control group (p < 0.05). Moreover, a notable increase in AB073614 expression levels coincided with a significant reduction in FER1L4 expression levels in AML samples (p < 0.05). The diagnostic value of these lncRNAs was validated using the receiver operating characteristic (ROC) curve and area under the curve (AUC) calculations. Sensitivity values of AB073614 and FER1L4 gene expression were 96.7% and 100%, respectively, using cut-off relative quantification of 1.045 and 0.770. Additionally, specificity values were observed to be 100%.

CONCLUSIONS

The present study indicates that AB073614 and FER1L4 might serve as prognosis biomarkers in AML patients. However, further detailed examinations in this field are warranted. It is proposed that the likely mechanism of imbalanced PI3K and PTEN activity, triggered by the deregulation of AB073614 and FER1L4, may have a crucial role in AML pathogenesis. Any component of this pathway could potentially serve as a new target for more insightful treatment approaches.

FER1L4：A long non-coding RNA with multiple roles in the occurrence and development of tumors

BACKGROUND

FER-1 family member 4 (FER1L4), a 6.7 kb lncRNA located at 20q11.22, plays an important biological function in a variety of tumor diseases. The purpose of this review is to clarify the pathophysiological mechanism and potential biological function of FER1L4 in different tumors.

METHODS

By searching the relevant literature of PubMed, the specific pathophysiological mechanism of FER1L4 in different tumors was summarized.

RESULTS

LncRNA FER1L4 is one of the key factors in tumorigenesis and is abnormally down-regulated in many tumors, including osteosarcoma, lung cancer, laryngeal squamous cell carcinoma, laryngeal cancer, colorectal cancer, ovarian cancer, prostate cancer, esophageal cancer, gastric cancer, endometrial cancer, osteoarthritis, rheumatoid arthritis and so on. However, FER1L4 is downregulated in breast cancer, glioma, oral squamous cell carcinoma, renal clear cell carcinoma and periodontitis, and plays a protective role in orthodontic teeth. In addition, as a tumor suppressor gene or oncogene, FER1L4 affects tumor proliferation, invasion, migration and apoptosis. Conclusion：LncRNA FER1L4 has a good application prospect in the treatment and diagnosis of many kinds of tumors.

p73-regulated FER1L4 lncRNA sponges the oncogenic potential of miR-1273g-3p and aids in the suppression of colorectal cancer metastasis

p73 belongs to the p53 tumor suppressor family and is involved in the suppression of metastasis. However, its specific mechanism of action remains to be elucidated. Long non-coding RNAs portray a crucial role in tumor suppression. We have identified lncRNA FER1L4 as a p73 transcriptional target. The binding of p73 to FER1L4 promoter was established by bioinformatics analysis, luciferase reporter, and ChIP assays. Both FER1L4 and p73 knockdown enhanced the migration and invasion rate of colorectal cancer cells. FER1L4 also plays a critical role in p73-mediated cell-cycle arrest and apoptosis. FER1L4 sponged the expression of miR-1273g-3p, which, in turn, increased PTEN expression, leading to cell-cycle arrest. RNA in situ hybridization revealed the down-regulation of both p73 and FER1L4 expression in a metastatic colon cancer tissue as compared with non-metastatic tissue. Collectively, we impart conclusive proof that p73 exerts its anti-metastatic properties by inducing lncRNA FER1L4 in response to genotoxic stress.

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Long non-coding RNA FER1L4 functions as a direct transcriptional target of p73

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FER1L4 plays a pivotal role in p73-mediated cell-cycle arrest and apoptosis

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FER1L4kd augments colorectal cancer cell proliferation in a p73-dependent manner

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p73-FER1L4 axis sponges miR-1273g-3p and inhibits its oncogenic role

Correlation between expression levels of lncRNA FER1L4 and RB1 in patients with colorectal cancer

Colorectal cancer (CRC) is a major life-threatening malignancy. Studies demonstrated the lncRNA fer-1 like family member 4 (FER1L4) was downregulated in different cancers and its expression was positively correlated with the retinoblastoma 1 (RB1) mRNA in a competing endogenous RNAs network. We investigated expression levels of FER1L4 and RB1 in patients with colorectal cancer. 50 paired colorectal tumors and non-tumor marginal tissues, 30 paired adenomatous colorectal polyps (ACPs) and matched adjacent normal tissues were obtained from the patients. Total RNA was extracted from the samples and cDNAs were synthesized. Their expression was quantified by qRT-PCR. Correlation between FER1L4 and RB1 expression levels was analyzed by Pearson correlation test. Finally, ROC curve analysis was used to evaluate their biomarker potency. We observed significant downregulation of FER1L4, but upregulation of RB1 in the colorectal tumors compared with non-tumor and the polyp tissues. However, RB1 expression was positively correlated with FER1L4 expression both in the tumor and polyp samples. ROC curve analysis showed both FER1L4 and RB1 expression levels could discriminate tumor from non-tumor and tumor from polyp samples. None of the clinicopathological characteristics of patients were associated with FER1L4 or RB1 expression levels. Despite the downregulation of FER1L4 and upregulation of RB1 in tumors compared with non-tumor tissues, the expression of RB1 was positively correlated with the expression of FER1L4 in the colorectal tumor as well as in the polyp tissues. FER1L4 expression level might be considered as a potential biomarker for colorectal cancer development.

DLX6-AS1/miR-204-5p/OCT1 positive feedback loop promotes tumor progression and epithelial-mesenchymal transition in gastric cancer

BACKGROUND

Accumulating evidence indicates that long non-coding RNAs (lncRNAs) participate in progression of gastric cancer (GC). Nevertheless, the function and expression level of DLX6-AS1 in GC remain unknown.

METHODS

We explored the sequencing data of DLX6-AS1 downloaded from The Cancer Genome Atlas. The expression of DLX6-AS1, miR-204-5p and OCT1 in 56 GC patients and GC cell lines was quantified by qRT-PCR and western blotting. Furthermore, we performed in vitro functional assays to assess proliferation, invasion and migration of GC cells by knockdown of DLX6-AS1. The expression level of epithelial-mesenchymal transition (EMT)-related genes was also determined by qRT-PCR and western blotting. Actin remodeling was detected by F-actin phalloidin staining. The luciferase reporter assay and chromatin immunoprecipitation assay was utilized to confirm the bioinformatic prediction. The function of the DLX6-AS1/miR-204-5p/OCT1 axis in GC proliferation was clarified by rescue assays.

RESULTS

We first demonstrated that DLX6-AS1 was upregulated in GC tissues and cell lines and was associated with T3/T4 invasion, distant metastasis and poor clinical prognosis. Further functional analysis showed that downregulation of DLX6-AS1 inhibited GC cell proliferation, migration, invasion and EMT in vitro. Mechanistic investigation indicated that DLX6-AS1 acted as a cancer-promoting competing endogenous RNA (ceRNA) by binding miR-204-5p and upregulating OCT1. Moreover, the transcription factor OCT1 was confirmed to enhance DLX6-AS1 expression by targeting the promoter region.

CONCLUSIONS

This study revealed that OCT1-induced DLX6-AS1 promoted GC progression and the EMT via the miR-204-5p/OCT1 axis, suggesting that this lncRNA might be a promising prognostic biomarker and therapeutic target for GC.

The lncRNA Fer1L4 is an adverse prognostic parameter in clear-cell renal-cell carcinoma

Purpose

Long non-coding RNAs (lncRNA) are involved in oncogenesis and tumor progression in various tumor entities. At present, little is known about the role in tumor biology of the lncRNA Fer-1 like family member 4 (Fer1L4) in clear-cell renal-cell carcinoma (ccRCC). The aim of this study is to evaluate the expression of Fer1L4 in patients with ccRCC, its association with clinicopathological parameters, and value as prognostic biomarker.

Material and methods

The expression of Fer1L4 was analyzed in the TCGA ccRCC cohort (n = 603; ccRCC n = 522, normal n = 81) and subsequently validated by quantitative real-time PCR in an independent cohort (n = 103, ccRCC n = 69, normal n = 34). Expression profiles were statistically correlated with clinicopathological and survival data.

Results

Fer1L4 lncRNA is overexpressed in ccRCC compared to adjacent normal tissues. Increased expression significantly correlates with tumor aggressiveness: high expression levels of Fer1L4 RNA were found in higher grade, higher stage, and metastatic tumors. Furthermore, Fer1L4 overexpression is an independent prognostic factor for overall, cancer-specific, and progression-free survival of patients with ccRCC.

Conclusion

Fer1L4 expression significantly correlates with aspects of tumor aggressiveness. Based on this impact on tumor progression and its influence as an independent prognostic factor, Fer1L4 appears to exert properties as an oncogene in ccRCC. As a prognostic tissue biomarker, further functional investigations are warranted to investigate Fer1L4 as a potential therapeutic target.

Long non-coding RNA TCL6 enhances preferential toxicity of paclitaxel to renal cell carcinoma cells

Background: Recent findings have shown long non-coding RNAs (lncRNAs) are dysregulated in a variety of cancer cells. In this report, we investigate the effect of T-cell leukemia lymphoma 6 (TCL6) on paclitaxel (PTX)-induced apoptosis in Renal cell carcinoma (RCC) cells. Methods: Expression levels of TCL6 in RCC tissues were analyzed via The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. Fluorescence in situ hybridization (FISH) was performed to detect the expression of TCL6 in RCC tissues and cells. Two pairs of cell lines were used: TCL6-silenced 786-O cell line and scrambled 786-O cell line, TCL6-overexpressed Caki-1 cell line and Caki-1 scrambled cell line. Cell viability was detected using the MTT assay. Apoptosis was examined by flow cemetery. Dual reporter gene assay was performed to confirm the direct downstream target miRNA of TCL6. Results: Based on RNA sequencing expression data of RCC tissues from TCGA and GEO datasets, the expression deficiency of TCL6 was observed in RCC tissues. Low level of TCL6 was associated with worse overall and disease-free survival of RCC patients. The FISH showed similar results with low expression of TCL6 in RCC tissues and cells. After PTX treatment, a time-dependent decrease in cell viability was observed in TCL6-overexpressed RCC cells and an increase in cell viability was observed in TCL6-silenced cells compared to control cells. Apoptosis induced by PTX was significantly increased in TCL6-overexpressed cells. Inhibition of TCL6 showed a significant decrease in apoptosis. Furthermore, luciferase reporter assay revealed that TCL6 is a direct target gene of miR-221. Conclusions: TCL6 effectively sensitizes RCC to PTX mainly through downregulation of miR-221. Our results suggest that PTX combined with TCL6 might be a potentially more effective chemotherapeutic approach for renal cancer.

Ferlin Overview: From Membrane to Cancer Biology

In mammal myocytes, endothelial cells and inner ear cells, ferlins are proteins involved in membrane processes such as fusion, recycling, endo- and exocytosis. They harbour several C2 domains allowing their interaction with phospholipids. The expression of several Ferlin genes was described as altered in several tumoural tissues. Intriguingly, beyond a simple alteration, myoferlin, otoferlin and Fer1L4 expressions were negatively correlated with patient survival in some cancer types. Therefore, it can be assumed that membrane biology is of extreme importance for cell survival and signalling, making Ferlin proteins core machinery indispensable for cancer cell adaptation to hostile environments. The evidences suggest that myoferlin, when overexpressed, enhances cancer cell proliferation, migration and metabolism by affecting various aspects of membrane biology. Targeting myoferlin using pharmacological compounds, gene transfer technology, or interfering RNA is now considered as an emerging therapeutic strategy.

Long non‑coding RNA FER1L4 inhibits cell proliferation and metastasis through regulation of the PI3K/AKT signaling pathway in lung cancer cells

Lung cancer is among the most common malignancies worldwide; however, the current understanding of its detailed mechanism remains limited. Long non-coding RNAs (lncRNAs) were previously identified to serve significant roles in tumorigenesis. The present study aimed to investigate the role of a novel lncRNA, Fer-1-like family member 4 (FER1L4), in lung tumorigenesis. In the present study, it was demonstrated that the expression level of FER1L4 was significantly decreased in clinical lung cancer tissues and in cultured lung cancer cells, as evidenced by reverse transcription-quantitative polymerase chain reaction analysis. Overexpression of FER1L4 in lung cancer cell lines A549 and 95D inhibited colony formation, cell proliferation and cell migration capacity, measured by colony formation assays, cell proliferation assays and Transwell assays, respectively. Overexpression of FER1L4 led to a reduction in the expression levels of phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) in A549 and 95D cells, whereas, activation of PI3K/Akt signaling using a small molecular inhibitor of phosphatase and tensin homolog, reversed the inhibitory effects of FER1L4 on cell proliferation and metastasis. All of these results suggested that the lncRNA FER1L4 suppressed cell proliferation and metastasis by inhibiting the PI3K/Akt signaling pathway in lung cancer.

FER1L4/miR-372/E2F1 works as a ceRNA system to regulate the proliferation and cell cycle of glioma cells

Long non-coding RNAs have recently become a key regulatory factor for cancers, whereas FER1L4, a newly discovered long non-coding RNA, has been mostly studied in gastric carcinoma and colon cancer cases. The functions and molecular mechanism of FER1L4 have been rarely reported in glioma malignant phenotypes. In this study, it was found that the expression of LncRNA FER1L4 is upregulated in high-grade gliomas than in low-grade cases and that a high expression of LncRNA FER1L4 predicts poor prognosis of gliomas. Meanwhile, in vitro study suggests that expression of FER1L4 with SiRNA knockdown obviously suppresses cell cycle and proliferation. It is further demonstrated by experiments that the FER1L4 knockdown suppresses growth of in vivo glioma. Besides, it is found in our study that LncRNA FER1L4 expression is positively correlated with E2F1 mRNA expression. After knockdown of FER1L4 expression, E2F1 expression is significantly down-regulated, whereas the expression of miR-372 is significantly up-regulated; the up-regulation of miR-372 leads to significant down-regulation of FER1L4 and E2F1 expression. In addition, it is also found that FER1L4 can be used as competitive endogenous RNA to interact or bind with miR-371 and thereby up-regulate E2F1, thus promoting the cycle and proliferation of glioma cells. It may be one of the molecular mechanisms in which FER1L4 plays its oncogene-like role in gliomas.

Non-Coding RNAs in Glioma

Glioma is the most aggressive brain tumor of the central nervous system. The ability of glioma cells to migrate, rapidly diffuse and invade normal adjacent tissue, their sustained proliferation, and heterogeneity contribute to an overall survival of approximately 15 months for most patients with high grade glioma. Numerous studies indicate that non-coding RNA species have critical functions across biological processes that regulate glioma initiation and progression. Recently, new data emerged, which shows that the cross-regulation between long non-coding RNAs and small non-coding RNAs contribute to phenotypic diversity of glioblastoma subclasses. In this paper, we review data of long non-coding RNA expression, which was evaluated in human glioma tissue samples during a five-year period. Thus, this review summarizes the following: (I) the role of non-coding RNAs in glioblastoma pathogenesis, (II) the potential application of non-coding RNA species in glioma-grading, (III) crosstalk between lncRNAs and miRNAs (IV) future perspectives of non-coding RNAs as biomarkers for glioma.