Overexpression of circCDR1as drives oral squamous cell carcinoma progression

Role of circRNAs in regulating cell death in cancer: a comprehensive review

Despite multiple diagnostic and therapeutic advances, including surgery, radiation therapy, and chemotherapy, cancer preserved its spot as a global health concern. Prompt cancer diagnosis, treatment, and prognosis depend on the discovery of new biomarkers and therapeutic strategies. Circular RNAs (circRNAs) are considered as a stable, conserved, abundant, and varied group of RNA molecules that perform multiple roles such as gene regulation. There is evidence that circRNAs interact with RNA-binding proteins, especially capturing miRNAs. An extensive amount of research has presented the substantial contribution of circRNAs in various types of cancer. To fully understand the linkage between circRNAs and cancer growth as a consequence of various cell death processes, including autophagy, ferroptosis, and apoptosis, more research is necessary. The expression of circRNAs could be controlled to limit the occurrence and growth of cancer, providing a more encouraging method of cancer treatment. Consequently, it is critical to understand how circRNAs affect various forms of cancer cell death and evaluate whether circRNAs could be used as targets to induce tumor death and increase the efficacy of chemotherapy. The current study aims to review and comprehend the effects that circular RNAs exert on cell apoptosis, autophagy, and ferroptosis in cancer to investigate potential cancer treatment targets.

Salivary miRNAs and cytokines associated with diagnosis and prognosis of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignant tumour in the oral and maxillofacial region. Early diagnosis can significantly improve the 5-year survival rate of patients with OSCC. Therefore, it is extremely important to differentiate OSCC patients early, easily and quickly. Human saliva contains a variety of components that can be used as biomarkers for the diagnosis and prognosis of OSCC. Studies have shown that salivary microRNAs (miRNAs) and cytokines are closely associated with the progression of OSCC. The aim of this review is to summarize the research progress of salivary biomarkers (miRNAs and cytokines) in the past 3 years, and to explore the possibility of using miRNAs and cytokines to improve the diagnosis and prognosis of OSCC.

Unveiling therapeutic avenues targeting xCT in head and neck cancer

Head and neck cancer (HNC) remains a major global health burden, prompting the need for innovative therapeutic strategies. This review examines the role of the cystine/glutamate antiporter (xCT) in HNC, specifically focusing on how xCT contributes to cancer progression through mechanisms such as redox imbalance, ferroptosis, and treatment resistance. The central questions addressed include how xCT dysregulation affects tumor biology and the potential for targeting xCT to enhance treatment outcomes. We explore recent developments in xCT-targeted current and emerging therapies, including xCT inhibitors and novel treatment modalities, and their role in addressing therapeutic challenges. This review aims to provide a comprehensive analysis of xCT as a therapeutic target and to outline future directions for research and clinical application.

Circ-OMAC drives metastasis in oral squamous cell carcinoma

OBJECTIVES

Accumulating studies have proved that the circular RNAs (circRNAs) play vital roles in human cancers. However, few circRNAs have been elucidated with lymph node metastasis. This study demonstrated that circ-oral cancer metastasis-associated circRNA (circ-OMAC) is required to regulate the oral squamous cell carcinoma (OSCC) metastasis.

MATERIALS AND METHODS

The circ-OMAC were detected by circRNA-sequencing and further verified by in situ hybridization (ISH). The role of circ-OMAC was assessed by transwell assay and wound healing assay. Mechanistically, circ-OMAC regulated OSCC metastasis by initiating the epithelial-to-mesenchymal transition (EMT) signaling pathway.

RESULTS

Our findings suggested that circ-OMAC was aberrantly elevated in the metastatic lymph nodes as compared to primary OSCC tissues. OSCC patients with high levels of circ-OMAC were prone to a poor prognosis. By developing functional assays, we confirmed that circ-OMAC promotes metastasis of OSCC cells via initiation of EMT pathways.

CONCLUSIONS

We provide new insights whereby Circ-OMAC as an oncogene is a potential therapeutic target and prognostic marker in oral cancer.

An inhibitor of claudin-5 interactions, M01, alleviates neuroinflammation and vasogenic edema after blood-spinal cord barrier dysfunction

Molecular docking modeling has confirmed that M01 (C30H28N4O5) acts as a potent inhibitor of claudin-5. Our prior data indicated that claudin-5 is essential to the structural integrity of the blood-spinal cord barrier (BSCB). The aim of this study was to investigate the effect of M01 on the integrity of the BSCB and its effect on neuroinflammation and vasogenic edema after blood-spinal cord barrier dysfunction in in-vitro and in-vivo models. Transwell chambers were used to construct an in-vitro model of the BSCB. Fluorescein isothiocyanate (FITC)-dextran permeability and leakage assays were performed to validate the reliability of the BSCB model. Semiquantitative analysis of inflammatory factor expression and nuclear factor-κB signaling pathway protein levels was performed using western blotting. The transendothelial electrical resistance of each group was measured, and the expression of a tight junction protein ZO-1 was determined via immunofluorescence confocal microscopy. Rat models of spinal cord injury were established by the modified Allen's weight-drop method. Histological analysis was carried out by hematoxylin and eosin staining. Locomotor activity was evaluated with Footprint analysis and the Basso-Beattie-Bresnahan scoring system. The M01 (10 μM) reduced the release of inflammatory factors and degradation of ZO-1 and improved the integrity of the BSCB by reversing vasogenic edema and leakage. M01 may represent a new strategy for the treatment of diseases related to BSCB destruction.

m6A-modified circFOXK2 targets GLUT1 to accelerate oral squamous cell carcinoma aerobic glycolysis

N⁶-methyladenosine (m⁶A) is an abundant nucleotide modification in mRNA, and its emerging roles have been gradually identified. However, the potential function of m⁶A and m⁶A-modified circular RNA (circRNA) is still unclear. Here, m⁶A-circRNA epitranscriptomic microarray analysis revealed a high-expressed m⁶A-modified circFOXK2 (hsa_circ_0000816, from FOXK2 gene) in oral squamous cell carcinoma (OSCC). For the biofunctions of OSCC, results revealed that circFOXK2 promoted the malignant phenotypes of OSCC cells. Methylated RNA immunoprecipitation sequencing (MeRIP-Seq) demonstrated that a remarkable m⁶A modified site was installed on glucose transporter 1 (GLUT1) mRNA. Mechanistically, circFOXK2 promoted the GLUT1 mRNA stability through cooperating with insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3) in a m⁶A-dependent manner. In summary, the present study explored the oncogenic role of m⁶A-modified circFOXK2 in OSCC through the m⁶A-dependent IGF2BP3/GLUT1 axis, indicating a potential therapeutic target for OSCC.

Circular RNA-related CeRNA network and prognostic signature for patients with oral squamous cell carcinoma

Background: Circular RNA (circRNA) has an important influence on oral squamous cell carcinoma (OSCC) progression as competing endogenous RNAs (ceRNAs). However, the link between ceRNAs and the OSCC immune microenvironment is unknown. The research aimed to find circRNAs implicated in OSCC carcinogenesis and progression and build a circRNA-based ceRNA network to create a reliable OSCC risk prediction model. Methods: The expression profiles of circRNA in OSCC tumors and normal tissues were assessed through RNA sequencing. From the TCGA database, clinicopathological data and expression patterns of microRNAs (miRNAs) and mRNAs were obtained. A network of circRNA-miRNA-mRNA ceRNA was prepared according to these differentially expressed RNAs and was analyzed through functional enrichment. Subsequently, based on the mRNA in the ceRNA network, the influence of the model on prognosis was then evaluated using a risk prediction model. Finally, considering survival, tumor-infiltrating immune cells (TICs), clinicopathological features, immunosuppressive molecules, and chemotherapy efficacy were analyzed. Results: Eleven differentially expressed circRNAs were found in cancer tissues relative to healthy tissues. We established a network of circRNA-miRNA-mRNA ceRNA, and the ceRNA network includes 123 mRNAs, six miRNAs, and four circRNAs. By the assessment of Genomes pathway and Kyoto Encyclopedia of Genes, it is found that in the cellular senescence, PI3K-AKT and mTOR signaling pathway mRNAs were mainly enrichment. An immune-related signature was created utilizing seven immune-related genes in the ceRNA network after univariate and multivariate analysis. The receiver operating characteristic of the nomogram exhibited satisfactory accuracy and predictive potential. According to a Kaplan-Meier analysis, the high-risk group's survival rate was signally lower than the group with low-risk. In addition, risk models were linked to clinicopathological characteristics, TICs, immune checkpoints, and antitumor drug susceptibility. Conclusion: The profiles of circRNAs expression of OSCC tissues differ significantly from normal tissues. Our study established a circRNA-associated ceRNA network associated with OSCC and identified essential prognostic genes. Furthermore, our proposed immune-based signature aims to help research OSCC etiology, prognostic marker screening, and immune response evaluation.

CircRNAs: Roles in regulating head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC), the most common head and neck malignant tumor, with only monotherapy, is characterized by poor prognosis, and low 5-year survival rate. Due to the lack of therapeutic targets, the targeted drugs for HNSCC are rare. Therefore, exploring the regulation mechanism of HNSCC and identifying effective therapeutic targets will be beneficial to its treatment of. Circular RNA (CircRNA) is a class of RNA molecules with a circular structure, which is widely expressed in human body. CircRNAs regulate gene expression by exerting the function as a miRNA sponge, thereby mediating the occurrence and development of HNSCC cell proliferation, apoptosis, migration, invasion, and other processes. In addition, circRNAs are also involved in the regulation of tumor sensitivity to chemical drugs and other biological functions. In this review, we systematically listed the functions of circRNAs and explored the regulatory mechanisms of circRNAs in HNSCC from the aspects of tumor growth, cell death, angiogenesis, tumor invasion and metastasis, tumor stem cell regulation, tumor drug resistance, immune escape, and tumor microenvironment. It will assist us in discovering new diagnostic markers and therapeutic targets, while encourage new ideas for the diagnosis and treatment of HNSCC.

Unravelling the roles of Autophagy in OSCC: A renewed perspective from mechanisms to potential applications

Oral squamous cell carcinoma (OSCC) is associated with a low survival rate and a high disability rate, making it a serious health burden, particularly in Southeast Asian countries. Therefore, improvements in the diagnosis, treatment, and prognosis prediction of OSCC are highly warranted. Autophagy has a significant impact on cancer development. Studies on autophagy in various human cancers have made outstanding contributions; however, the relationship between autophagy and OSCC remains to be explored. This review highlights the roles of autophagy in OSCC and discusses the relationship between autophagy and Epithelial–mesenchymal transition. Considering the lack of OSCC biomarkers, we focus on the studies involving OSCC-related bioinformatics analysis and molecular targets. Based on some classical targets, we summarize several key autophagy-related biomarkers with a considerable potential for clinical application, which may become the hotspot of OSCC research. In conclusion, we elaborate on the interrelationship between autophagy and OSCC and highlight the shortcomings of current studies to provide insights into the potential clinical strategies.

Circular RNA-regulated autophagy is involved in cancer progression

Circular RNAs (circRNAs) are a sort of long, non-coding RNA molecules with a covalently closed continuous ring structure without 5'-3' polarity and poly-A tail. The modulative role of circRNAs in malignant diseases has been elucidated by many studies in recent years via bioinformatics and high-throughput sequencing technologies. Generally, circRNA affects the proliferative, invasive, and migrative capacity of malignant cells via various mechanisms, exhibiting great potential as novel biomarkers in the diagnoses or treatments of malignancies. Meanwhile, autophagy preserves cellular homeostasis, serving as a vital molecular process in tumor progression. Mounting studies have demonstrated that autophagy can not only contribute to cancer cell survival but can also induce autophagic cell death in specific conditions. A growing number of research studies have indicated that there existed abundant associations between circRNAs and autophagy. Herein, we systemically reviewed and discussed recent studies on this topic in different malignancies and concluded that the circRNA–autophagy axis played crucial roles in the proliferation, metastasis, invasion, and drug or radiation resistance of different tumor cells.

Non-Coding RNAs and Oral Cancer: Small Molecules With Big Functions

Oral cancer remains a major public concern with considerable socioeconomic impact in the world. Despite substantial advancements have been made in treating oral cancer, the five-year survival rate for oral cancer remained undesirable, and the molecular mechanisms underlying OSCC carcinogenesis have not been fully understood. Noncoding RNAs (ncRNAs) include transfer RNAs (tRNAs), as well as small RNAs such as microRNAs, and the long ncRNAs such as HOTAIR are a large segment of the transcriptome that do not have apparent protein-coding roles, but they have been verified to play important roles in diverse biological processes, including cancer cell development. Cell death, such as apoptosis, necrosis, and autophagy, plays a vital role in the progression of cancer. A better understanding of the regulatory relationships between ncRNAs and these various types of cancer cell death is therefore urgently required. The occurrence and development of oral cancer can be controlled by increasing or decreasing the expression of ncRNAs, a method which confers broad prospects for oral cancer treatment. Therefore, it is urgent for us to understand the influence of ncRNAs on the development of different modes of oral tumor death, and to evaluate whether ncRNAs have the potential to be used as biological targets for inducing cell death and recurrence of chemotherapy. The purpose of this review is to describe the impact of ncRNAs on cell apoptosis and autophagy in oral cancer in order to explore potential targets for oral cancer therapy.

MicroRNAs in the Regulation of Solute Carrier Proteins Behind Xenobiotic and Nutrient Transport in Cells

Altered metabolism, such as aerobic glycolysis or the Warburg effect, has been recognized as characteristics of tumor cells for almost a century. Since then, there is accumulating evidence to demonstrate the metabolic reprogramming of tumor cells, addiction to excessive uptake and metabolism of key nutrients, to support rapid proliferation and invasion under tumor microenvironment. The solute carrier (SLC) superfamily transporters are responsible for influx or efflux of a wide variety of xenobiotic and metabolites that are needed for the cells to function, as well as some medications. To meet the increased demand for nutrients and energy, SLC transporters are frequently dysregulated in cancer cells. The SLCs responsible for the transport of key nutrients for cancer metabolism and energetics, such as glucose and amino acids, are of particular interest for their roles in tumor progression and metastasis. Meanwhile, rewired metabolism is accompanied by the dysregulation of microRNAs (miRNAs or miRs) that are small, noncoding RNAs governing posttranscriptional gene regulation. Studies have shown that many miRNAs directly regulate the expression of specific SLC transporters in normal or diseased cells. Changes of SLC transporter expression and function can subsequently alter the uptake of nutrients or therapeutics. Given the important role for miRNAs in regulating disease progression, there is growing interest in developing miRNA-based therapies, beyond serving as potential diagnostic or prognostic biomarkers. In this article, we discuss how miRNAs regulate the expression of SLC transporters and highlight potential influence on the supply of essential nutrients for cell metabolism and drug exposure toward desired efficacy.

Negative regulation of miR-1288-3p/KRT4 axis through a circular RNA in oral cancer

Circular RNA (circRNA) has been widely reported to be involved in oral squamous cell carcinoma (OSCC), while the way in which hsa_circ_0096042 affects OSCC remains unclear. The hsa_circ_0096042, miR-1288-3p, and KRT4 expression in OSCC tissues and cell lines were detected by quantitative reverse-transcription polymerase chain reaction. Based on the overexpression of hsa_circ_0096042, miR-1288-3p, or KRT4, the viability and proliferation of OSCC cells were analyzed by cell counting kit-8 and colony formation assay, and the protein levels of Bax and Bcl-2 were detected by western blot, and the growth of cancer cells in vivo was analyzed by xenograft experiment. In addition, the database was used to predict the binding of hsa_circ_0096042, miR-1288-3p, and KRT4, and the interaction was confirmed by luciferase, RIP, and RNA pull-down assay. Hsa_circ_0096042 and KRT4 were abnormally downregulated and miR-1288-3p was upregulated in OSCC. Hsa_circ_0096042 overexpression restrained the proliferation and viability of OSCC cells, facilitated apoptosis, and inhibited the growth of cancer cells in vivo. Hsa_circ_0096042 bound to miR-1288-3p, whose upregulation promoted OSCC progression and eliminated the effects of overexpression of hsa_circ_0096042 on OSCC cells. KRT4 was the target gene for miR-1288-3p. Hsa_circ_0096042 plays an antitumor role in OSCC via miR-1288-3p/KRT4 axis.