LncRNA LHFPL3-AS1 Promotes Oral Squamous Cell Carcinoma Growth and Cisplatin Resistance Through Targeting miR-362-5p/CHSY1 Pathway

LINC00342 regulates the PI3K-AKT signaling pathway via the miR-149-5p/FGF11 axis and affects the progression of oral cancer

BACKGROUND

A large number of long non-coding RNAs (lncRNAs) have been implicated in the progression of oral cancer (OC). This study aimed to investigate the role of a novel lncRNA, LINC00342, in OC and elucidate its molecular mechanism.

METHODS

Differential expression of lncRNA/miRNA/mRNA was analyzed using the Gene Expression Omnibus database and validated with RT-qPCR. Additionally, the expression levels of these molecules in OC cells and their effects on cell viability and cell cycle were assessed using the Cell Counting Kit-8 and flow cytometry. RNA bindings was analyzed by dual luciferase, and Western blot was used to detect the activation of relevant pathways.

RESULTS

This study showed that, in contrast to miR-149-5p, the expression of LINC00342 and fibroblast growth factor 11 (FGF11) were upregulated in OC cells (LINC00342: 10.00 ± 1.06 (FaDu) and 3.55 ± 0.25 (CAL-27) vs 1.00 ± 0.07 (HOECs), P < 0.05; FGF11: 7.31 ± 0.33 (FaDu) and 3.43 ± 0.08 (CAL-27) vs 1.00 ± 0.10 (HOECs), P < 0.05). Dual-luciferase assays confirmed that LINC00342 bind to miR-149-5p in a direct targeting manner. Furthermore, inhibition of LINC00342 expression resulted in decreased proliferation rate (FaDu: 136.22 ± 22.10% vs 59.36 ± 8.98% (control), P < 0.05; CAL-27: 131.40 ± 11.58% vs 49.83 ± 11.19 (control), P < 0.05) and migration ability of OC cells, cell cycle arrest in G1 phase, and inhibition of PI3K-AKT signaling. Inhibition of miR-149-5p or overexpression of FGF11 reversed the effects of si-LINC00342.

CONCLUSIONS

LINC00342 promotes PI3K-AKT signaling by activating FGF11 through adsorption of miR-149-5p, thereby regulating the progression of OC.

Novel insights on oral squamous cell carcinoma management using long non-coding RNAs

Oral squamous cell carcinoma (OSCC) is one of the most prevalent forms of head and neck squamous cell carcinomas (HNSCC) with a poor overall survival rate (about 50%), particularly in cases of metastasis. RNA-based cancer biomarkers are a relatively advanced concept, and non-coding RNAs currently have shown promising roles in the detection and treatment of various malignancies. This review underlines the function of long non-coding RNAs (lncRNAs) in the OSCC and its subsequent clinical implications. LncRNAs, a class of non-coding RNAs, are larger than 200 nucleotides and resemble mRNA in numerous ways. However, unlike mRNA, lncRNA regulates multiple druggable and non-druggable signaling molecules through simultaneous interaction with DNA, RNA, proteins, or microRNAs depending on concentration and localization in cells. Upregulation of oncogenic lncRNAs and down-regulation of tumor suppressor lncRNAs are evident in OSCC tissues and body fluids such as blood and saliva indicating their potential as valuable biomarkers. Targeted inhibition of candidate oncogenic lncRNAs or over-expression of tumor suppressor lncRNAs showed potential therapeutic roles in in-vivo animal models. The types of lncRNAs that are expressed differentially in OSCC tissue and bodily fluids have been systematically documented with specificity and sensitivity. This review thoroughly discusses the biological functions of such lncRNAs in OSCC cell survival, proliferation, invasion, migration, metastasis, angiogenesis, metabolism, epigenetic modification, tumor immune microenvironment, and drug resistance. Subsequently, we addressed the diagnostic and therapeutic importance of lncRNAs in OSCC pre-clinical and clinical systems, providing details on ongoing research and outlining potential future directions for advancements in this field. In essence, this review could be a valuable resource by offering comprehensive and current insights into lncRNAs in OSCC for researchers in fundamental and clinical domains.

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.

Establishment, characterization, and genetic profiling of patient-derived osteosarcoma cells from a patient with retinoblastoma

Osteosarcoma is the most common malignant bone cancer in pediatric patients. Patients who respond poorly to chemotherapy experience worse clinical outcomes with a high mortality rate. The major challenge is the lack of effective drugs for these patients. To introduce new drugs for clinical approval, preclinical studies based on in vitro models must demonstrate the potency of the tested drugs, enabling the drugs to enter phase 1 clinical trials. Patient-derived cell culture is a promising testing platform for in vitro studies, as they more accurately recapitulate cancer states and genetic profiles compared to cell lines. In the present study, we established patient-derived osteosarcoma cells (PDC) from a patient who had previously been diagnosed with retinoblastoma. We identified a new variant of a germline mutation in the RB1 gene in the tissue of the patient. The biological effects of this PDC were studied to observe whether the cryopreserved PDC retained a feature of fresh PDC. The cryopreserved PDC preserved the key biological effects, including cell growth, invasive capability, migration, and mineralization, that define the conserved phenotypes compared to fresh PDC. From whole genome sequencing analysis of osteosarcoma tissue and patient-derived cells, we found that cryopreserved PDC was a minor population in the origin tissue and was selectively grown under the culture conditions. The cryopreserved PDC has a high resistance to conventional chemotherapy. This study demonstrated that the established cryopreserved PDC has the aggressive characteristics of osteosarcoma, in particular the chemoresistance phenotype that might be used for further investigation in the chemoresistant mechanism of osteosarcoma. In conclusion, the approach we applied for primary cell culture might be a promising method to generate in vitro models for functional testing of osteosarcoma.

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.

Hsa_circ_0005050 regulated the progression of oral squamous cell carcinoma via miR-487a-3p/CHSY1 axis

Background/purpose

Circular RNAs (circRNAs) have been identified as potential functional modulators of the cellular physiology processes. This study aims to learn the potential molecular mechanisms of hsa_circ_0005050 (circ_0005050) in oral squamous cell carcinoma (OSCC).

Materials and methods

Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to examine the expression of circ_0005050, miR-487a-3p, and chondroitin sulfate synthase 1 (CHSY1). Dual-luciferase reporter system, RNA pull-down, and RNA Immunoprecipitation (RIP) assays were used to determine the binding between miR-487a-3p and circ_0005050 or CHSY1. Colony formation experiment and EdU assay were used to investigate proliferation. Wound-healing and transwell assays were used to detect the migration of cells. The apoptosis rate of OSCC cells was tested by flow cytometry. Protein levels of related factors were determined by Western blot. Tumor xenograft was established to determine the regulatory role of circ_0005050 on tumor growth in vivo, and Ki-67 expression was detected in this xenograft using Immunohistochemical (IHC).

Results

We implicated that circ_0005050 was apparently upregulated in OSCC tissues cells. In function experiments, repressing of circ_0005050 remarkably retarded OSCC growth in vitro. Furthermore, we conducted dual-luciferase reporter assays and RNA pull-down assays to verify that circ_0005050 sponged miR-487a-3p. Suppression of miR-487a-3p rescued the inhibition of proliferation in SCC15 and SCC25 cells induced by circ_0005050 knockdown. In addition, we found that overexpression of CHSY1 also reversed the inhibitory effect of circ_0005050 silencing on cell proliferation. Moreover, circ_0005050 knockdown inhibited tumor growth in vivo.

Conclusion

Circ_0005050 acted as an oncogenic factor in OSCC progression through miR-487a-3p/CHSY1 axis.

Emerging role of lncRNAs in drug resistance mechanisms in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) originates in the squamous cell lining the mucosal surfaces of the head and neck region, including the oral cavity, nasopharynx, tonsils, oropharynx, larynx, and hypopharynx. The heterogeneity, anatomical, and functional characteristics of the patient make the HNSCC a complex and difficult-to-treat disease, leading to a poor survival rate and a decreased quality of life due to the loss of important physiologic functions and aggressive surgical injury. Alteration of driver-oncogenic and tumor-suppressing lncRNAs has recently been recently in HNSCC to obtain possible biomarkers for diagnostic, prognostic, and therapeutic approaches. This review provides current knowledge about the implication of lncRNAs in drug resistance mechanisms in HNSCC. Chemotherapy resistance is a major therapeutic challenge in HNSCC in which lncRNAs are implicated. Lately, it has been shown that lncRNAs involved in autophagy induced by chemotherapy and epithelial–mesenchymal transition (EMT) can act as mechanisms of resistance to anticancer drugs. Conversely, lncRNAs involved in mesenchymal–epithelial transition (MET) are related to chemosensitivity and inhibition of invasiveness of drug-resistant cells. In this regard, long non-coding RNAs (lncRNAs) play a pivotal role in both processes and are important for cancer detection, progression, diagnosis, therapy response, and prognostic values. As the involvement of more lncRNAs is elucidated in chemoresistance mechanisms, an improvement in diagnostic and prognostic tools could promote an advance in targeted and specific therapies in precision oncology.

Down-regulated long non-coding RNA LHFPL3 antisense RNA 1 inhibits the radiotherapy resistance of nasopharyngeal carcinoma via modulating microRNA-143-5p/homeobox A6 axis

The function of long non-coding RNA LHFPL3 antisense RNA 1 (LHFPL3-AS1) in cancer progression has been studied, while its role in nasopharyngeal carcinoma (NPC) remains unclear. This study aims to unravel the effects of LHFPL3-AS1 on NPC progression via microRNA (miR)-143-5p/homeobox A6 (HOXA6) axis. NPC tissues were collected and NPC cells were cultured. NPC cells were subjected to radiation therapy to construct the radiation therapy resistance NPC cell line. The levels of LHFPL3-AS1, miR-143-5p and HOXA6 in NPC cells and tissues were examined. LHFPL3-AS1, miR-143-5p or HOXA6 expression was changed and then transfected into radiation-resistant NPC cells to detect cell proliferation, colony formation, migration, invasion and cell apoptosis in vitro. The tumorigenesis in nude mice in vivo was conducted to detect tumor growth. The targeting relations among LHFPL3-AS1, miR-143-5p and HOXA6 were validated. It was discovered that LHFPL3-AS1 and HOXA6 expression was elevated while the miR-143-5p level was depleted in radiation-resistant NPC cells and NPC tissues. The silenced LHFPL3-AS1 or augmented miR-143-5p repressed the proliferation, colony formation, migration and invasion of radiation-resistant NPC cells, while accelerated cell apoptosis in vitro. Silenced LHFPL3-AS1 hindered tumor growth in vivo. MiR-143-5p deletion reversed the effects of reduced LHFPL3-AS1; while HOXA6 upregulation reversed the effects of enriched miR-143-5p. LHFPL3-AS1 sponged miR-143-5p that targeted HOXA6. It is concluded that the down-regulated LHFPL3-AS1 retards the development of radiation-resistant NPC cells via sponging miR-143-5p to modulate HOXA6. This study reveals novel therapeutic targets for NPC treatment.

Long Noncoding RNA LAMTOR5-AS1 Interference Affects MicroRNA-506-3p/E2F6-Mediated Behavior of Non-Small Cell Lung Cancer Cells

Long noncoding RNA LAMTOR5 antisense RNA 1 (LAMTOR5-AS1) has been certified as a risk predictor and diagnostic biomarker of prostate cancer. However, the expression and exact roles of LAMTOR5-AS1 in non-small cell lung cancer (NSCLC) remain unclear. Thus, we measured LAMTOR5-AS1 expression in NSCLC and gauged its clinical value. The detailed roles and downstream working mechanism of LAMTOR5-AS1 in NSCLC were comprehensively unraveled. qRT-PCR was applied to measure gene expression. Functionally, utilizing small interfering RNA, LAMTOR5-AS1 was ablated, and the functional alterations were addressed by means of different experiments. The targeting activities between LAMTOR5-AS1 and microRNA-506-3p (miR-506-3p) and between miR-506-3p and E2F transcription factor 6 (E2F6) were confirmed by RNA immunoprecipitation and luciferase reporter assays. LAMTOR5-AS1 overexpression in NSCLC was verified in TCGA datasets and our own cohort and manifested an evident relationship with poor prognosis. Interference with LAMTOR5-AS1 led to repression of the proliferation, cloning, and metastasis abilities of NSCLC cells in vitro. We further confirmed an obvious increase in LAMTOR5-AS1-silenced NSCLC cell apoptosis. Furthermore, the absence of LAMTOR5-AS1 restricted tumor growth in vivo. Mechanistically, LAMTOR5-AS1 sponged miR-506-3p in NSCLC cells. Furthermore, E2F6, a downstream target of miR-506-3p, was under the control of LAMTOR5-AS1, which was realized by decoying miR-506-3p. Rescue experiments showed that miR-506-3p suppression or E2F6 reintroduction was capable of remitting LAMTOR5-AS1 deficiency-triggered anticarcinogenic actions in NSCLC. Our study confirmed the exact roles of LAMTOR5-AS1 for the first time and revealed that LAMTOR5-AS1 knockdown disrupts the malignancy of NSCLC by targeting the miR-506-3p/E2F6 axis. Targeting the LAMTOR5-AS1/miR-506-3p/E2F6 pathway may be instrumental for managing patients with NSCLC.

Long Non-Coding RNA (lncRNA) in Oral Squamous Cell Carcinoma: Biological Function and Clinical Application

Simple Summary

Increasing evidence has revealed the regulatory roles of long non-coding RNAs (lncRNAs) in the initiation and progress of oral squamous cell carcinoma (OSCC). As some novel lncRNA-targeted techniques combined with immune checkpoint therapies have emerged, they provide a new strategy for OSCC treatment. This review summarizes current knowledge regarding the involvement of lncRNAs in OSCC along with their possible use as diagnostic and prognostic biomarker and therapeutic targets.

Abstract

Oral squamous cell carcinoma (OSCC) is a type of malignancy with high mortality, leading to poor prognosis worldwide. However, the molecular mechanisms underlying OSCC carcinogenesis have not been fully understood. Recently, the discovery and characterization of long non-coding RNAs (lncRNAs) have revealed their regulatory importance in OSCC. Abnormal expression of lncRNAs has been broadly implicated in the initiation and progress of tumors. In this review, we summarize the functions and molecular mechanisms regarding these lncRNAs in OSCC. In addition, we highlight the crosstalk between lncRNA and tumor microenvironment (TME), and discuss the potential applications of lncRNAs as diagnostic and prognostic tools and therapeutic targets in OSCC. Notably, we also discuss lncRNA-targeted therapeutic techniques including CRISPR-Cas9 as well as immune checkpoint therapies to target lncRNA and the PD-1/PD-L1 axis. Therefore, this review presents the future perspectives of lncRNAs in OSCC therapy, but more research is needed to allow the applications of these findings to the clinic.

The Molecular Basis and Therapeutic Aspects of Cisplatin Resistance in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is a kind of malignant tumors with low survival rate and prone to have early metastasis and recurrence. Cisplatin is an alkylating agent which induces DNA damage through the formation of cisplatin-DNA adducts, leading to cell cycle arrest and apoptosis. In the management of advanced OSCC, cisplatin-based chemotherapy or chemoradiotherapy has been considered as the first-line treatment. Unfortunately, only a portion of OSCC patients can benefit from cisplatin treatment, both inherent resistance and acquired resistance greatly limit the efficacy of cisplatin and even cause treatment failure. Herein, this review outline the underlying mechanisms of cisplatin resistance in OSCC from the aspects of DNA damage and repair, epigenetic regulation, transport processes, programmed cell death and tumor microenvironment. In addition, this review summarizes the strategies applicable to overcome cisplatin resistance, which can provide new ideas to improve the clinical therapeutic outcome of OSCC.

Exosome-derived microRNAs in oral squamous cell carcinomas impact disease prognosis

OBJECTIVES

microRNA (miRNA) expression patterns have provided new insight as biomarkers of prognosis as well as novel therapeutic targets for several neoplasms. However, the role of exosomal miRNA in the prognosis of oral squamous cell carcinoma (OSCC) has not yet been completely clarified. Paired primary tumor and normal oral epithelial cells from OSCC patients were obtained, and the exosomal miRNA profiles between them were compared by miRNA microarray analysis. The miRNA levels in the serum exosomes of OSCC patients were verified by real-time quantitative reverse transcription PCR (qRT-PCR) analysis. Finally, the biological functions and the potential as a prognostic marker of the selected miRNA candidates were analyzed in the OSCC cells and patients, respectively.

RESULTS

Exosomal miR-155 and miR-21 were significantly upregulated, and exosomal miR-126 was dramatically downregulated in the primary OSCC cells and the serum of OSCC patients. In the analysis of oncogenic behaviors, coculture with either miR-155-rich or miR-21-rich exosomes could promote cell proliferation and invasion accompanied with downregulation of PTEN and Bcl-6 tumor suppressors. Moreover, treatment with miR-126-rich exosomes inhibited oncogenic behaviors and oncogene EGFL7 expression in OSCC cells. Finally, exosomal miR-126 was reduced in the serum of the late-staged OSCC patients, and downregulation of blood exosomal miR-126 was associated with poor survival in OSCC patients.

CONCLUSION

Exosomal miR-155 and miR-21 are oncogenic miRNAs which suppress PTEN and Bcl-6 expression, and exosomal miR-126 acts as a tumor suppressor which downregulates EGFL7 in OSCC. Furthermore, blood exosomal miRNAs may serve as biomarkers for the diagnosis and prognosis of OSCC.