Analysis of Long Noncoding RNA ZNF667-AS1 as a Potential Biomarker for Diagnosis and Prognosis of Glioma Patients

LncRNA ZNF667-AS1 Targets miR-523-3p/KIF5C Axis to Hinder Colon Cancer Progression

LncRNA ZNF667-AS1 plays an important role in the carcinogenesis and progression of various cancers. However, their role in colon cancer (CC) remains unclear. The expression of ZNF667-AS1, KIF5C, and miR-523-3p in CC cells and tissues was analyzed using RT-qPCR and western blotting. CCK-8 scratch-wound assay, western blotting, and flow cytometry were conducted to investigate the malignant activity of CC in vitro. Luciferase reporter, RNA pull-down, and Ago2 immunoprecipitation (RIP) experiments were conducted to ascertain the association of miR-523-3p with ZNF667-AS1 and KIF5C 3'UTR. Xenograft tumor experiments were also performed. CC cells and tissues showed low expression of NF667-AS1 and KIF5C and elevated expression of miR-523-3p. ZNF667-AS1 overexpression attenuates proliferation and migration of CC cells, restores inactivated apoptosis in vitro, and inhibits tumor growth in vivo. MiR-523-3p targets both ZNF667-AS1 and the KIF5C 3'UTR. ZNF667-AS1 overexpression in SW480 and SW620 cells attenuated the oncogenic effect of miR-523-3p in CC. However, this attenuating effect was counteracted by KIF5C overexpression. ZNF667-AS1 sequestered miR-523-3, reducing miR-523-3p-mediated inhibition of KIF5C expression, thereby repressing colon carcinogenesis in vitro. Our findings shed light on a novel anticancer strategy that could potentially combat CC.

Epigenetic characterization of housekeeping core promoters and their importance in tumor suppression

In this research, we elucidate the presence of around 11,000 housekeeping cis-regulatory elements (HK-CREs) and describe their main characteristics. Besides the trivial promoters of housekeeping genes, most HK-CREs reside in promoter regions and are involved in a broader role beyond housekeeping gene regulation. HK-CREs are conserved regions rich in unmethylated CpG sites. Their distribution highly correlates with that of protein-coding genes, and they interact with many genes over long distances. We observed reduced activity of a subset of HK-CREs in diverse cancer subtypes due to aberrant methylation, particularly those located in chromosome 19 and associated with zinc finger genes. Further analysis of samples from 17 cancer subtypes showed a significantly increased survival probability of patients with higher expression of these genes, suggesting them as housekeeping tumor suppressor genes. Overall, our work unravels the presence of housekeeping CREs indispensable for the maintenance and stability of cells.

Hsa_circ_0049396 inhibited oral squamous cell carcinoma progression by regulating the miR-663b/ENDOU axis

BACKGROUND

Circular RNA (circRNAs) play an important role in oral squamous cell carcinoma (OSCC) progression and has been widely reported. In this study, we aimed to investigate the role of a novel circRNA, circ_0049396, and its underlying mechanism in OSCC.

METHODS

The expression levels of circ_0049396, miR-663b, and theuridylate-specific endoribonuclease (ENDOU) were assessed by quantitative reverse transcription PCR (qRT-PCR). Cell proliferation and migration were evaluated using CCK-8 and Transwell assays, respectively. Western blotting was performed to measure the levels of the apoptosis-associated proteins (Bcl-2 and Bax). The functional role of circ _0049396 was further validated in a xenograft experiment in vivo. The interactions of miR-663b with circ_0049396/ENDOU were verified using the dual luciferase reporter, RNA pull-down, and RNA immunoprecipitation (RIP) assays.

RESULTS

The expression of circ_0049396 and ENDOU was downregulated in OSCC tissues and cells, whereas miR-663b was upregulated. Circ_0049396 overexpression weakened OSCC cell proliferation and migration but enhanced their apoptosis. Circ_0049396 overexpression suppresses tumorigenesis in vivo. The circ_0049396/miR-663b/ENDOU regulatory network predicted through bioinformatic analysis was validated using RNA pull-down, luciferase reporter, and RIP experiments. MiR-663b mimic enhanced the migratory and proliferative abilities of OSCC cells, but suppressed apoptosis. Furthermore, circ_0049396 or ENDOU overexpression partially reversed the malignant behavior of miR-663b-overexpressing OSCC cells.

CONCLUSIONS

Our study illustrated that circ_0049396 overexpression inhibited the malignant behavior of OSCC cells by regulating the miR-663b/ENDOU axis. Based on our findings, circ_0049396 can be used as a potential therapeutic agent for OSCC.

LncRNA as potential biomarker and therapeutic target in glioma

Glioma is the most frequent type of malignant tumor in the central nervous system, accounting for about 80% of primary malignant brain tumors, usually with a poor prognosis. A number of studies have been conducted on the molecular abnormalities in glioma to further understand its pathogenesis, and it has been found that lncRNAs (long non-coding RNA) play a key role in angiogenesis, tumor growth, infiltration and metastasis of glioma. Since specific lncRNAs have an aberrant expression in brain tissue, cerebrospinal fluid as well as peripheral circulation of glioma patients, they are considered to be potential biomarkers. This review focuses on the biological characteristics of lncRNA and its value as a biomarker for glioma diagnosis and prognosis. Moreover, in view of the role of lncRNAs in glioma proliferation and chemoradiotherapy resistance, we discussed the feasibility for lncRNAs as therapeutic targets. Finally, the persisting deficiencies and future prospects of using lncRNAs as clinical biomarkers and therapeutic targets were concluded.

Latest updates on cellular and molecular biomarkers of gliomas

Gliomas are the most common central nervous system malignancies, compromising almost 80% of all brain tumors and is associated with significant mortality. The classification of gliomas has shifted from basic histological perspective to one that is based on molecular biomarkers. Treatment of this type of tumors consists currently of surgery, chemotherapy and radiation therapy. During the past years, there was a limited development of effective glioma diagnostics and therapeutics due to multiple factors including the presence of blood-brain barrier and the heterogeneity of this type of tumors. Currently, it is necessary to highlight the advantage of molecular diagnosis of gliomas to develop patient targeted therapies based on multiple oncogenic pathway. In this review, we will evaluate the development of cellular and molecular biomarkers for the diagnosis of gliomas and the impact of these diagnostic tools for better tailored and targeted therapies.

The lncRNA ZNF667-AS1 Inhibits Propagation, Invasion, and Angiogenesis of Gastric Cancer by Silencing the Expression of N-Cadherin and VEGFA

Purpose. Gastric cancer is one of the most common malignancies with high mortality worldwide. It is known that long noncoding RNAs (lncRNAs) play important roles in the pathogenesis of gastric cancer. This study investigates the role of lncRNA ZNF667-AS1 in gastric cancer cells. Methods. We have applied real-time quantitative PCR (qPCR) to study the levels of ZNF667-AS1 in gastric cancer biopsies and cell lines. The effects of ZNF667-AS1 on the propagation, clonogenicity, metastasis, and angiogenesis of gastric cancer cells were evaluated by calorimetry, colony formation, cell migration, and angiogenesis assays. Western blotting was used to identify the levels of proteins involved in cancer invasion and angiogenesis signaling pathways. Result. It was found that lncRNA ZNF667-AS1 was downregulated in gastric cancer biopsies. Overexpression of ZNF667-AS1 reduced the propagation, migration, and angiogenesis of gastric cancer cells. Molecular mechanism studies displayed that the high level of lncRNA ZNF667-AS1 promoted the expression of E-cadherin and inhibited the expression of N-cadherin and VEGFA, leading to the inhibition of the proliferation, migration, and angiogenesis of gastric cancer cells. Conclusion. As a tumor suppressor gene, lncRNA ZNF667-AS1 significantly hinders the propagation, metastasis, and angiogenesis of gastric cancer cells by promoting the expression of E-cadherin and inhibiting the expression of N-cadherin and VEGFA. Therefore, lncRNA ZNF667-AS1 could play a synergistic therapeutic role by targeting tumor cells and vascular endothelial cells, which represents a new therapeutic scheme for novel therapeutics of gastric cancer.

Long Noncoding RNA AC007639.1 Promotes the Pathogenesis and Progression of Hepatocellular Carcinoma Through Inhibiting Apoptosis and Stimulating Chemotherapeutic Resistance

Background

Hepatocellular carcinoma (HCC) is known for its poor prognosis. Long noncoding RNAs (lncRNAs) are critical in the pathogenesis of various types of cancers. We tried to explore the role of lncRNA in the development of HCC.

Methods

We identified the role of lncRNA AC007639.1 in the pathogenesis of HCC through bioinformatics and biological experiments in HepG2, Hep3B, and SMMC-7721 cells as well as the nude mice xenograft model.

Results

We found that lncRNA AC007639.1 was overexpressed in hepatocellular carcinoma. Knocking down of lncRNA AC007639.1 by specific siRNAs or shRNAs promoted cancer cell death. The growth of mouse xenograft tumor created using lncRNA AC007639.1 deficient HepG2 cells was significantly slowed down. Furthermore, the knockdown of lncRNA AC007639.1 in HCC cells led to the increased expression of p53 and decreased expression of angiopoietin-like 4.

Conclusion

LncRNA AC007639.1 was involved in the pathogenesis and progression of hepatocellular carcinoma by inhibition of apoptosis and increasing HCC resistance to chemotherapy.

LncRNA MORT (ZNF667-AS1) in Cancer-Is There a Possible Role in Gynecological Malignancies?

Gynecological cancers (GCs) are currently among the major threats to female health. Moreover, there are different histologic subtypes of these cancers, which are defined as ‘rare’ due to an annual incidence of <6 per 100,000 women. The majority of these tend to be associated with a poor prognosis. Long non-coding RNAs (lncRNAs) play a critical role in the normal development of organisms as well as in tumorigenesis. LncRNAs can be classified into tumor suppressor genes or oncogenes, depending on their function within the cellular context and the signaling pathways in which they are involved. These regulatory RNAs are potential therapeutic targets for cancer due to their tissue and tumor specificity. However, there still needs to be a deeper understanding of the mechanisms by which lncRNAs are involved in the regulation of numerous biological functions in humans, both in normal health and disease. The lncRNA Mortal Obligate RNA Transcript (MORT; alias ZNF667-AS1) has been identified as a tumor-related lncRNA. ZNF667-AS1 gene, located in the human chromosome region 19q13.43, has been shown to be silenced by DNA hypermethylation in several cancers. In this review, we report on the biological functions of ZNF667-AS1 from recent studies and describe the regulatory functions of ZNF667-AS1 in human disease, including cancer. Furthermore, we discuss the emerging insights into the potential role of ZNF667-AS1 as a biomarker and novel therapeutic target in cancer, including GCs (ovarian, cervical, and endometrial cancers).