Long non‑coding RNA Fer‑1‑like family member 4 suppresses hepatocellular carcinoma cell proliferation by regulating PTEN in vitro and in vivo

The Impact of Long Non-Coding RNAs in the Pathogenesis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is among the utmost deadly human malignancies. This type of cancer has been associated with several environmental, viral, and lifestyle risk factors. Among the epigenetic factors which contribute in the pathogenesis of HCC is dysregulation of long non-coding RNAs (lncRNAs). These transcripts modulate expression of several tumor suppressor genes and oncogenes and alter the activity of cancer-related signaling axes. Several lncRNAs such as NEAT1, MALAT1, ANRIL, and SNHG1 have been up-regulated in HCC samples. On the other hand, a number of so-called tumor suppressor lncRNAs namely CASS2 and MEG3 are down-regulated in HCC. The interaction between lncRNAs and miRNAs regulate expression of a number of mRNA coding genes which are involved in the pathogenesis of HCC. H19/miR-15b/CDC42, H19/miR-326/TWIST1, NEAT1/miR-485/STAT3, MALAT1/miR-124-3p/Slug, MALAT1/miR-195/EGFR, MALAT1/miR-22/SNAI1, and ANRIL/miR-144/PBX3 axes are among functional axes in the pathobiology of HCC. Some genetic polymorphisms within non-coding regions of the genome have been associated with risk of HCC in certain populations. In the current paper, we describe the recent finding about the impact of lncRNAs in HCC.

lncRNA GABPB1 intronic transcript 1 upregulates pigment epithelium-derived factor via miR-93 to suppress cell proliferation in hepatocellular carcinoma

Liver cancer ranks in the top 10 most common malignancies for both mortality rate and incidence worldwide. Hepatocellular carcinoma (HCC) is the most common subtype of liver cancer. It has been reported that long non-coding RNA GABPB1 intronic transcript 1 (IT1) is downregulated in lung cancer and predicts poor survival. However, its role in live cancer remains unclear. Therefore, the present study aimed to investigate the role of GABPB1-IT1 in HCC. A total of 64 patients with HCC (40 males and 24 females; range, 43-67 years old; mean age=55.1±5.1 years) were enrolled at the 96604 Military Hospital of the Chinese People's Liberation Army between May 2012 and May 2014. The expression levels of GABPB1-IT1 and microRNA (miR)-93 in tumor and adjacent normal tissues were measured using quantitative PCR. A dual luciferase activity assay was performed to analyze the interaction between miR-93 and GABPB1-IT1. A Cell Counting Kit-8 assay was used to analyze the effect of miR transfection on the proliferation of SNU-398 cells. It was demonstrated that GABPB1-IT1 can interact with miR-93 in HCC cells, while overexpression of GABPB1-IT1 and miR-93 in HCC cells did not affect the expression of each other. GABPB1-IT1 was downregulated in HCC tissues compared with paired non-tumor tissues and predicted poor survival. Notably, overexpression of GABPB1-IT1 in HCC cells led to upregulation of pigment epithelium-derived factor (PEDF), a target of miR-93. In addition, overexpression of GABPB1-IT1 reduced the enhancing effects of miR-93 on HCC cell proliferation. Therefore, GABPB1-IT1 may upregulate PEDF through miR-93 to suppress cell proliferation in HCC.

Effects of FER1L4-miR-106a-5p/miR-372-5p-E2F1 regulatory axis on drug resistance in liver cancer chemotherapy

Liver cancer presents a challenge in today's healthcare system. This study aimed at investigating the effects of Fer-1 like family member 4 (FER1L4) on chemotherapy resistance and liver cancer development by using clinically collected liver cancer tissues and commercially purchased human liver cancer cisplatin-resistant cell line HUH-7/DDP. Bioinformatics analysis, dual luciferase reporter gene assay, and RNA pull-down were applied to predict and verify the possible binding relationships. The expressions of FER1L4, E2F transcription factor 1 (E2F1), microRNA-106a-5p (miR-106a-5p), or miR-372-5p were altered in the cells, followed by flow cytometry, Cell Counting Kit-8 (CCK-8), and Transwell assays to evaluate apoptotic, proliferative, and invasive abilities in vitro and nude mice xenografts to observe tumor growth in vivo. FER1L4 was highly expressed and miR-106-5p and miR-372-5p were poorly expressed in tumor cells and tissues. FER1L4 knockdown or the overexpression of miR-106-5p and miR-372-5p inhibited the cancerous cell proliferation and invasion while promoting apoptosis. FERIL4 silencing increased the miR-106-5p/miR-372-5p expression to inhibit the E2F1-activated nuclear factor κB (NF-κB) pathway. Besides, overexpressing FER1L4 led to an increased tumor growth in nude mice, which was reversed by the NF-κB inhibitor pyrollidine dithiocarbamate (PDTC). In conclusion, the results indicated that FER1L4 could inhibit the expression of miR-106a-5p/miR-372-5p, to activate E2F1-mediated NF-κB pathway, leading to drug resistance in liver cancer.

Long Non-coding RNA FER1L4 Mediates the Autophagy of Periodontal Ligament Stem Cells Under Orthodontic Compressive Force via AKT/FOXO3 Pathway

Orthodontic tooth movement is achieved by periodontal tissue remodeling triggered by mechanical force. It is essential to investigate the reaction of periodontal ligament stem cells (PDLSCs) for improving orthodontic therapeutic approaches. Autophagy is an endogenous defense mechanism to prevent mechanical damage of environmental change. Long non-coding RNAs (lncRNAs) are key regulators in gene regulation, but their roles are still largely uncharacterized in the reaction of PDLSCs during orthodontic tooth movement. In this study, we showed that autophagy was significantly induced in PDLSCs under compressive force, as revealed by the markers of autophagy, microtubule-associated protein light chain 3 (LC3) II/I and Beclin1, and the formation of autophagosomes. After the application of compressive force, lncRNA FER1L4 was strongly upregulated. Overexpression of FER1L4 increased the formation of autophagosome and autolysosomes in PDLSCs, while knockdown of FER1L4 reversed the autophagic activity induced by mechanical force. In mechanism, FER1L4 inhibited the phosphorylation of protein kinase B (AKT) and subsequently increased the nuclear translocation of forkhead box O3 (FOXO3) and thus mediated autophagic cascades under compressive strain. In mouse model, the expression of Lc3 as well as Fer1l4 was increased in the pressure side of periodontal ligament during tooth movement. These findings suggest a novel mechanism of autophagy regulation by lncRNA during periodontal tissue remodeling of orthodontic treatment.

LncRNA LINC02418 affects proliferation, migration, invasion, and apoptosis of hepatocellular carcinoma cells by regulating miR-940 expression

BACKGROUND

The long noncoding RNA (lncRNA) LINC02418 is up-regulated in non-small cell lung cancer, lung adenocarcinoma, colorectal cancer, and other tumors, and promotes the development of tumors. However, the role and mechanism of LINC02418 in the occurrence and development of liver cancer are unknown. Target gene prediction with LncBase Predicted v.2 shows that LINC02418 may target miR-940. This study hypothesized that LINC02418 can target and regulate miR-940 to affect the proliferation, migration, invasion, and apoptosis of liver cancer cells, thereby affecting the development of liver cancer.

AIM

To investigate the effect of lncRNA LINC02418 on the proliferation, migration, invasion, and apoptosis of hepatocellular carcinoma cells and the underlying mechanism.

METHODS

RT-qPCR was used to detect the expression levels of LINC02418 and miR-940 in hepatocellular carcinoma cancer tissues and adjacent tissues. After LINC02418 small interfering RNA or miR-940 mimic was transfected into liver cancer HCCLM3 cells, RT-qPCR was used to detect the transfection efficiency, and CCK-8 assay, Transwell assay, flow cytometry, and Western blot were used to detect the effects of LINC02418 down-regulation or miR-940 up-regulation on HCCLM3 cell viability, migration, invasion, and apoptosis, as well as the protein expression levels of CyclinD1, p21, MMP-2, MMP-9, Bcl-2, and Bax. The regulatory relationship between miR-940 and LINC02418 was verified by double luciferase reporter gene assay.

RESULTS

Compared with adjacent tissues, the expression of LINC02418 in hepatocellular carcinoma tissues increased (P < 0.05), while the expression of miR-940 decreased (P < 0.05). Down-regulating LINC02418 or up-regulating miR-940 reduced HCCLM3 cell viability, the number of migrating and invading cells, and the protein expression of CyclinD1, MMP-2, MMP-9, and Bcl-2 (P < 0.05), but increased apoptosis and the protein expression of p21 and Bax (P < 0.05). LINC02418 negatively regulated the expression of miR-940. Down-regulating miR-940 reversed the effects of down-regulating LINC02418 on the proliferation, migration, invasion, and apoptosis of HCCLM3 cells.

CONCLUSION

The expression of LINC02418 is elevated in liver cancer tissues, and down-regulating its expression may inhibit the malignant biological behavior of hepatocellular carcinoma cells by up-regulating miR-940, which could be used as a molecular target for liver cancer treatment.

Functions of Vertebrate Ferlins

Ferlins are multiple-C2-domain proteins involved in Ca²⁺-triggered membrane dynamics within the secretory, endocytic and lysosomal pathways. In bony vertebrates there are six ferlin genes encoding, in humans, dysferlin, otoferlin, myoferlin, Fer1L5 and 6 and the long noncoding RNA Fer1L4. Mutations in DYSF (dysferlin) can cause a range of muscle diseases with various clinical manifestations collectively known as dysferlinopathies, including limb-girdle muscular dystrophy type 2B (LGMD2B) and Miyoshi myopathy. A mutation in MYOF (myoferlin) was linked to a muscular dystrophy accompanied by cardiomyopathy. Mutations in OTOF (otoferlin) can be the cause of nonsyndromic deafness DFNB9. Dysregulated expression of any human ferlin may be associated with development of cancer. This review provides a detailed description of functions of the vertebrate ferlins with a focus on muscle ferlins and discusses the mechanisms leading to disease development.

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.

Current Status of Gene Therapy in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the second leading cause of cancer related deaths world-wide. Liver transplantation, surgical resection, trans-arterial chemoembolization, and radio frequency ablation are effective strategies to treat early stage HCC. Unfortunately, HCC is usually diagnosed at an advanced stage and there are not many treatment options for late stage HCC. First-line therapy for late stage HCC includes sorafenib and lenvatinib. However, these treatments provide only an approximate three month increase in survival. Besides, they cannot specifically target cancer cells that lead to a wide array of side effects. Patients on these drugs develop resistance within a few months and have to rely on second-line therapy that includes regorafenib, pembrolizumab, nivolumab, and cabometyx. These disadvantages make gene therapy approach to treat HCC an attractive option. The two important questions that researchers have been trying to answer in the last 2-3 decades are what genes should be targeted and what delivery systems should be used. The objective of this review is to analyze the changing landscape of HCC gene therapy, with a focus on these two questions.