LINC00662 Promotes Oral Squamous Cell Carcinoma Cell Growth and Metastasis through miR-144-3p/EZH2 Axis

LncRNA AFAP1-AS1 Promotes Oral Squamous Cell Carcinoma Development by Ubiquitin-Mediated Proteolysis

BACKGROUND AND PURPOSE

Long noncoding RNA (lncRNA) dysregulation has been reported to play a pivotal role in the development of cancers. In this study, we aimed to screen the key lncRNA in oral squamous cell carcinoma (OSCC) via bioinformatics analysis and further validate the function of lncRNA in vitro and in vivo.

METHODS

Bioinformatics analysis was conducted to identify differentially expressed lncRNAs between control and OSCC samples. Quantitative real-time-polymerase chain reaction was employed to detect the expression of differentially expressed lncRNAs in human tongue squamous cell carcinoma and human oral keratinocytes cell lines. The biological function of lncRNA and its mechanism were examined via the experimental assessment of the cell lines with the lncRNA overexpressed and silenced. Additionally, to further explore the function of lncRNA in the progression of OSCC, xenograft tumour mouse models were established using 25 mice (5 groups, each with 5 mice). Tumour formation was observed at 2 weeks after the cell injection, and the tumours were resected at 5 weeks post-implantation.

RESULTS

Two lncRNAs, LINC00958 and AFAP1-AS1, were found to be correlated with the prognosis of OSCC. The results of the quantitative real-time-polymerase chain reaction indicated that the 2 lncRNAs were highly expressed in OSCC. In combination with the previous literature, we found AFAP1-AS1 to be a potentially important biomarker for OSCC. Thus, we further investigated its biological function and found that AFAP1-AS1 silencing inhibited cell proliferation, migration, and invasion whereas AFAP1-AS1 overexpression reversed the effect of AFAP1-AS1 silencing (P < .05). Mechanism analysis revealed that AFAP1-AS1 regulated the development of OSCC through the ubiquitin-mediated proteolysis pathway.

CONCLUSIONS

AFAP1-AS1 is an oncogene that aggravates the development of OSCC via the ubiquitin-mediated proteolysis pathway. It also provides a novel potential therapy for OSCC.

LINC00662 Promotes Aggressive Traits by Modulating OCT4 Expression through miR-335-5p in Gallbladder Cancer Cells

Long non-coding RNAs (lncRNAs) are nucleotide sequences that participate in different biological processes and are associated with different pathologies, including cancer. Long intergenic non-protein-coding RNA 662 (LINC00662) has been reported to be involved in different cancers, including colorectal, prostate, and breast cancer. However, its role in gallbladder cancer has not yet been described. In this article, we hypothesize that LINC00662 has an important role in the acquisition of aggressiveness traits such as a stem-like phenotype, invasion, and chemoresistance in gallbladder cancer. Here, we show that LINC00662 is associated with larger tumor size and lymph node metastasis in patients with gallbladder cancer. Furthermore, we show that the overexpression of LINC00662 promotes an increase in CD133+/CD44+ cell populations and the expression of stemness-associated genes. LINC00662 promotes greater invasive capacity and the expression of genes associated with epithelial-mesenchymal transition. In addition, the expression of LINC00662 promotes resistance to cisplatin and 5-fluorouracil, associated with increased expression of chemoresistance-related ATP-binding cassette (ABC) transporters in gallbladder cancer (GBC) cell lines. Finally, we show that the mechanism by which LINC00662 exerts its function is through a decrease in microRNA 335-5p (miR-335-5p) and an increase in octamer-binding transcription factor 4 (OCT4) in GBC cells. Thus, our data allow us to propose LINC00662 as a biomarker of poor prognosis and a potential therapeutic target for patients with GBC.

LncRNA FOXD2-AS1 promotes the growth, invasion and migration of OSCC cells by regulating the MiR-185-5p/PLOD1/Akt/mTOR pathway

Although lncRNAs are recognized to contribute to the development of oral squamous-cell carcinoma (OSCC), their exact function in invasion and cell migration is not clear. In this research, we explored the molecular and cellular mechanisms of FOXD2-AS1 in OSCC. Prognostic and bioinformatics analyses were used to test for the differential expression of FOXD2-AS1-PLOD1. Following FOXD2-AS1 suppression or overexpression, changes in cell viability were measured using the CCK-8 test; changes in cell migration and invasion abilities were measured using the migration and the Transwell assay. The expression of associated genes and proteins was found using Western blot and RT-qPCR. Analysis of luciferase reporter genes was done to look for regulatory connections between various molecules. The FOXD2-AS1-PLOD1 pair, which was highly expressed in OSCC, was analyzed and experimentally verified to be closely related to the prognosis of OSCC, and a nomogram model and correction curve were constructed. The inhibition of FOXD2-AS1 resulted in the reduction of cell activity, migration, invasion ability and changes in genes related to invasion and migration. In vivo validation showed that inhibition of FOXD2-AS1 expression slowed tumor growth, and related proteins changed accordingly. The experiments verified that FOXD2-AS1 negatively regulated miR-185-5 p and that miR-185-5 p negatively regulated PLOD1. In addition, it was found that the expression of PLOD1, p-Akt and p-mTOR proteins in OSCC cells was reduced by the inhibition of FOXD2-AS1, and FOXD2-AS1 and PLOD1 were closely related to the Akt/mTOR pathway. Increased expression of FOXD2-AS1 promotes OSCC growth, invasion and migration, which is important in part by targeting miR-185-5 p/PLOD1/Akt/mTOR pathway activity.

Linc00662 sponges miR-15b-5p to promote hypopharyngeal squamous cell carcinoma progression by facilitating cancer stem cell-like phenotypes

Background: Long non-coding RNAs (lncRNAs) are associated with multiple head and neck tumors and play important roles in cancer. This study explored the molecular mechanism of Linc00662 in hypopharyngeal squamous cell carcinoma (HSCC). Methods: Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect gene expression in HSCC tissues. The viability and proliferation of tumor cells were measured using CCK-8 assays. HSCC cell apoptosis was measured using flow cytometry and western blotting. Cell stemness was examined using the sphere formation assay. A xenograft tumor model was established to investigate the role of Linc00662 in vivo. Results: The expression level of Linc00662 in HSCC tissues was significantly higher than that in adjacent normal tissues. The expression of Linc00662 had no significant relationship with the tumor stage. Patients with high Linc00662 expression were found to have shorter overall survival than those with low Linc00662 expression. Linc00662 over-expression promoted cell viability and inhibited apoptosis. Using online databases and a dual luciferase reporter, miR-15b-5p was confirmed as a potential downstream sponge of Linc00662. Moreover, Linc00662 was negatively associated with miR-15b-5p in HSCC cells. Depletion of miR-15b-5p can reverse the function of Linc00662 in vivo and in vitro. Furthermore, Linc00662 promotes tumor growth, which was abolished by miR-15b-5p mimics. Importantly, the stemness of cancer stem cells was mediated by the Linc00662/miR-15b-5p axis. Conclusion: Patients with HSCC with high Linc00662 showed poor prognosis and high Linc00662 induced stemness of tumor cells by targeting miR-15b-5p. Linc00662 may serve as a novel diagnostic and target marker for head and neck squamous cell carcinoma.

Dysregulation of noncoding RNA in chordoma; implications in identifying potential targets for novel therapeutic approaches

Chordoma is a rare form of bone cancer develops in the spinal cord and skull. Instead of conventional (radio/chemotherapies) and targeted therapies, the disease is associated with high rate of recurrence and poor patient survival. Thus, for better disease management, the molecular pathogenesis of chordoma should be studied in detail to identify dysregulated biomolecules that can be targeted by novel therapeutics. Recent research showed frequent dysregulation of long noncoding RNA (lncRNA), microRNA (miRNA), and circular RNA (circRNA) in association with aggressive tumor phenotypes like cell proliferation, migration, invasion, and metastasis in a variety of cancers, including chordoma. Apart from diagnostic and prognostic importance, noncoding RNAs may serve as promising targets for novel therapeutics in cancer. In this review, we summarized a list of miRNAs, lncRNAs, and circRNA found to be dysregulated in chordoma from available data published in relevant databases (PubMed), as such an approach seems to be rare to date. The dysregulated noncoding RNAs were also associated with adverse tumor phenotypes to assess the impact on disease pathogenesis and, associated downstream molecular pathways were focused. Synthetic compounds and natural products that were reported to target the noncoding RNAs in other malignancies were also listed from published literature and proposed as potential therapeutic agents in chordoma. This review will provide information for further research on chordoma focusing on detailed characterization of dysregulated lncRNAs, miRNAs, and circRNA to understand the disease pathogenesis and, exploration of suitable natural and synthetic products targeting dysregulated non-coding RNAs to develop effective therapeutic measures.

LINC00662 promotes melanoma progression by competitively binding miR-107 and activating the β-catenin signaling pathway

Melanoma is a highly malignant tumor in the body. Long non-coding RNAs (lncRNAs) have been reported to be involved in the development of various tumors. Emerging evidence demonstrates the critical role of lncRNAs in melanoma development. In this study, we aimed to investigate the expression, biological function and regulatory mechanism of LINC00662 in melanomas. First, we found that LINC00662 was up-regulated in melanoma tissues and cell lines. High expression of LINC00662 in melanomas was associated with a poor patient prognosis. Silencing of LINC00662 suppressed the proliferation, migration, and invasion of melanoma cells in vitro and in vivo, while overexpression of LINC00662 promoted melanoma cell proliferation in vitro. Bioinformatics analysis, dual-luciferase assay, and RIP assay confirmed that LINC00662 competitively regulated miR-107. Silencing of LINC00662 upregulated miR-107 expression in a melanoma cell line. Inhibition of miR-107 significantly reversed the inhibitory effect of LINC00662 silencing on cell proliferation and migration. Furthermore, POU3F2 was validated as a downstream target of LINC00662/miR107 and was downregulated when LINC00662 was silenced. Overexpressing POU3F2 attenuated the effect of si-LINC00662 on cellular functions. In addition, the results also showed that the β-catenin pathway was involved in a si-LINC00662-induced function in melanoma. Overall, our results confirmed that LINC00662 promoted melanoma progression by sponging miR107 and inducing POU3F2, highlighting the mechanism of the LINC00662/miR-107/POU3F2 axis in melanoma cell proliferation and invasion.

A snapshot of miRNAs in oral squamous cell carcinoma: Difference between cancer cells and corresponding normal cells

Oral squamous cell carcinoma (OSCC) constitutes the most aggressive tumors of the oral cavity and is one of the leading causes of cancer mortality worldwide. Although recent clinical treatment strategies have improved the survival rate, the outcome of OSCC patients still remains dismal because of the lack of efficient diagnostic and treatment tools. As one of the main actors of OSCC scenario, microRNAs (miRNAs) are involved in triggering, progression and metastasis through the regulation of various cancer-related signaling pathways. Identification followed by precise study of the biology and mechanism of action of miRNAs will greatly help to provide valuable insights regarding OSCC development and can be considered as an anti-OSCC target. In the current review, we have provided a focused summary of the latest published papers on the role of miRNAs in apoptosis, cell cycle, proliferation, EMT and metastasis of OSCC as well as the role of long noncoding RNAs in the modulation of miRNAs in OSCC.

MiRNA-related metastasis in oral cancer: moving and shaking

Across the world, oral cancer is a prevalent tumor. Over the years, both its mortality and incidence have grown. Oral cancer metastasis is a complex process involving cell invasion, migration, proliferation, and egress from cancer tissue either by lymphatic vessels or blood vessels. MicroRNAs (miRNAs) are essential short non-coding RNAs, which can act either as tumor suppressors or as oncogenes to control cancer development. Cancer metastasis is a multi-step process, in which miRNAs can inhibit or stimulate metastasis at all stages, including epithelial-mesenchymal transition, migration, invasion, and colonization, by targeting critical genes in these pathways. On the other hand, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), two different types of non-coding RNAs, can regulate cancer metastasis by affecting gene expression through cross-talk with miRNAs. We reviewed the scientific literature (Google Scholar, Scopus, and PubMed) for the period 2000-2023 to find reports concerning miRNAs and lncRNA/circRNA-miRNA-mRNA networks, which control the spread of oral cancer cells by affecting invasion, migration, and metastasis. According to these reports, miRNAs are involved in the regulation of metastasis pathways either by directly or indirectly targeting genes associated with metastasis. Moreover, circRNAs and lncRNAs can induce or suppress oral cancer metastasis by acting as competing endogenous RNAs to inhibit the effect of miRNA suppression on specific mRNAs. Overall, non-coding RNAs (especially miRNAs) could help to create innovative therapeutic methods for the control of oral cancer metastases.

Non-Coding RNAs in Oral Cancer: Emerging Roles and Clinical Applications

Oral cancer (OC) is among the most prevalent cancers in the world. Certain geographical areas are disproportionately affected by OC cases due to the regional differences in dietary habits, tobacco and alcohol consumption. However, conventional therapeutic methods do not yield satisfying treatment outcomes. Thus, there is an urgent need to understand the disease process and to develop diagnostic and therapeutic strategies for OC. In this review, we discuss the role of various types of ncRNAs in OC, and their promising clinical implications as prognostic or diagnostic markers and therapeutic targets. MicroRNA (miRNA), long ncRNA (lncRNA), circular RNA (circRNA), PIWI-interacting RNA (piRNA), and small nucleolar RNA (snoRNA) are the major ncRNA types whose involvement in OC are emerging. Dysregulated expression of ncRNAs, particularly miRNAs, lncRNAs, and circRNAs, are linked with the initiation, progression, as well as therapy resistance of OC via modulation in a series of cellular pathways through epigenetic, transcriptional, post-transcriptional, and translational modifications. Differential expressions of miRNAs and lncRNAs in blood, saliva or extracellular vesicles have indicated potential diagnostic and prognostic importance. In this review, we have summarized all the promising aspects of ncRNAs in the management of OC.

Noncoding RNA-mediated macrophage and cancer cell crosstalk in hepatocellular carcinoma

The tumor microenvironment (TME) is a well-recognized system that plays an essential role in tumor initiation, development, and progression. Intense intercellular communication between tumor cells and other cells (especially macrophages) occurs in the TME and is mediated by cell-to-cell contact and/or soluble messengers. Emerging evidence indicates that noncoding RNAs (ncRNAs) are critical regulators of the relationship between cells within the TME. In this review, we provide an update on the regulation of ncRNAs (primarily micro RNAs [miRNAs], long ncRNAs [lncRNAs], and circular RNAs [circRNAs]) in the crosstalk between macrophages and tumor cells in hepatocellular carcinoma (HCC). These ncRNAs are derived from macrophages or tumor cells and act as oncogenes or tumor suppressors, contributing to tumor progression not only by regulating the physiological and pathological processes of tumor cells but also by controlling macrophage infiltration, activation, polarization, and function. Herein, we also explore the options available for clinical therapeutic strategies targeting crosstalk-related ncRNAs to treat HCC. A better understanding of the relationship between macrophages and tumor cells mediated by ncRNAs will uncover new diagnostic biomarkers and pharmacological targets in cancer.

Downregulation of circLPAR3 inhibits tumor progression and glycolysis by liberating miR‐144‐3p and upregulating LPCAT1 in oral squamous cell carcinoma

Background

Increasing evidence demonstrated the important roles of circular RNAs (circRNAs) in human cancer progression, including oral squamous cell carcinoma (OSCC). The study intentions were to explore the role and molecular mechanism of hsa_circ_0004390 (circLPAR3) in OSCC progression.

Methods

Expression of circLPAR3 in collected samples and cultured cell lines was detected with real‐time quantitative reverse transcription‐polymerase chain reaction (RT‐qPCR). Loss‐of‐function experiments were performed to determine the effect of circLPAR3 silencing on OSCC cell proliferation, migration, invasion, apoptosis, angiopoiesis, and glycolysis. The sponge function of circLPAR3 was predicted by bioinformatics analysis and validated by the dual‐luciferase reporter and RNA pull‐down assays. In vivo experiments were conducted to validate the function of circLPAR3.

Results

A marked increase in circLPAR3 expression was observed in OSCC samples and cell lines. Furthermore, circLPAR3 could distinguish OSCC samples from paired non‐tumor samples, and patients with high circLPAR3 expression had a poor prognosis. Furthermore, circLPAR3 inhibition decreased OSCC growth in xenograft mouse models. Moreover, circLPAR3 silencing repressed cell proliferation, migration, invasion, angiopoiesis, glycolysis, and induced cell apoptosis in OSCC cells in vitro. Mechanically, circLPAR3 sponged miR‐144‐3p to prohibit the inhibiting effect of miR‐144‐3p on LPCAT1, thus promoting OSCC progression.

Conclusion

CircLPAR3 exerted a tumor‐promoting effect on OSCC growth through elevating LPCAT1 expression via functioning as a miR‐144‐3p sponge. This study supports the possible role of circLPAR3 in the diagnosis, prognosis, and treatment of OSCC.