MicroRNA-22 suppresses cell proliferation, migration and invasion in oral squamous cell carcinoma by targeting NLRP3

Unravelling the Significance of NLRP3 and IL-β1 in Oral Squamous Cell Carcinoma and Potentially Malignant Oral Disorders: A Diagnostic and Prognostic Exploration

BACKGROUND

Nucleotide-binding domain-like receptor protein 3 (NLRP3), an inflammasome, is reported to be dysregulated or aberrantly expressed in chronic inflammation, leading to a myriad of inflammatory disorders, autoimmune diseases, and cancer. This study aimed to explore the expression and role of NLRP3 protein and the secreted cytokine IL-β1 in oral squamous cell carcinoma (OSCC) and potentially malignant oral disorders (PMOD).

MATERIAL & METHODS

Tissue NLRP3 expression was quantified using sandwich ELISA in 30 cases each of OSCC, PMOD, and normal oral mucosa. Serum IL-β1 level was also measured by ELISA to determine their correlation. In surgically treated OSCC cases, pathological parameters such as tumor size, depth of invasion (DOI), pTNM stage, and perineural & lymphovascular invasion were assessed and correlated with NLRP3 & IL-β1 levels to investigate their roles in tumor progression, invasion, and metastasis.

RESULTS

Tissue NLRP3 expression was markedly elevated in OSCC, with significant IL-β1 levels observed in the serum of both OSCC and PMOD cases. Both markers showed a pronounced increase with the severity of dysplasia, indicating a strong association (p = 0.003%). The expression levels of tissue NLRP3 and serum IL-β1 were positively correlated with DOI and tumor size. Furthermore, their elevated levels, alongside higher histological grades, indicate roles in the dedifferentiation and progression of tumor cells.

CONCLUSION

The findings indicated that increased expression of NLRP3 and IL-β1 in PMOD correlates with higher transformation rates, along with tumor progression and dedifferentiation in OSCC. Consequently, these markers hold promise as valuable targets for prognostic assessment, diagnostics, and therapeutic strategies in OSCC.

Molecular and Therapeutic Roles of Non-Coding RNAs in Oral Cancer-A Review

Oral cancer (OC) is among the most common malignancies in the world. Despite advances in therapy, the worst-case scenario for OC remains metastasis, with a 50% survival rate. Therefore, it is critical to comprehend the pathophysiology of the condition and to create diagnostic and treatment plans for OC. The development of high-throughput genome sequencing has revealed that over 90% of the human genome encodes non-coding transcripts, or transcripts that do not code for any proteins. This paper describes the function of these different kinds of non-coding RNAs (ncRNAs) in OC as well as their intriguing therapeutic potential. The onset and development of OC, as well as treatment resistance, are linked to dysregulated ncRNA expression. These ncRNAs' potentially significant roles in diagnosis and prognosis have been suggested by their differing expression in blood or saliva. We have outlined every promising feature of ncRNAs in the treatment of OC in this study.

Restoration of epigenetic impairment in the skeletal muscle and chronic inflammation resolution as a therapeutic approach in sarcopenia

Sarcopenia is an age-associated loss of skeletal muscle mass, strength, and function, accompanied by severe adverse health outcomes, such as falls and fractures, functional decline, high health costs, and mortality. Hence, its prevention and treatment have become increasingly urgent. However, despite the wide prevalence and extensive research on sarcopenia, no FDA-approved disease-modifying drugs exist. This is probably due to a poor understanding of the mechanisms underlying its pathophysiology. Recent evidence demonstrate that sarcopenia development is characterized by two key elements: (i) epigenetic dysregulation of multiple molecular pathways associated with sarcopenia pathogenesis, such as protein remodeling, insulin resistance, mitochondria impairments, and (ii) the creation of a systemic, chronic, low-grade inflammation (SCLGI). In this review, we focus on the epigenetic regulators that have been implicated in skeletal muscle deterioration, their individual roles, and possible crosstalk. We also discuss epidrugs, which are the pharmaceuticals with the potential to restore the epigenetic mechanisms deregulated in sarcopenia. In addition, we discuss the mechanisms underlying failed SCLGI resolution in sarcopenia and the potential application of pro-resolving molecules, comprising specialized pro-resolving mediators (SPMs) and their stable mimetics and receptor agonists. These compounds, as well as epidrugs, reveal beneficial effects in preclinical studies related to sarcopenia. Based on these encouraging observations, we propose the combination of epidrugs with SCLI-resolving agents as a new therapeutic approach for sarcopenia that can effectively attenuate of its manifestations.

MicroRNA-mediated epigenetic regulation of inflammasomes in inflammatory responses and immunopathologies

Inflammation represents the first-line defense mechanism of the host against pathogens and cellular stress. One of the most critical inflammatory responses is characterized by the activation of inflammasomes, intracellular multiprotein complexes that induce inflammatory signaling pathways in response to various pathogen-associated molecular patterns or danger-associated molecular patterns under physiological and pathological conditions. Inflammasomes are tightly regulated in normal cells, and dysregulation of these complexes is observed in various pathological conditions, especially inflammatory diseases and cancers. Epigenetic regulation has been suggested as a key mechanism in modulating inflammasome activity, and microRNAs (miRNAs) have been implicated in the post-transcriptional regulation of inflammasomes. Therefore, miRNA-mediated epigenetic regulation of inflammasomes in pathological conditions has received considerable attention, and current strategies for targeting inflammasomes have been shown to be effective in the treatment of diseases associated with inflammasome activation. This review summarizes recent studies suggesting the roles of miRNAs in the epigenetic control of inflammasomes and highlights the potential of miRNAs as a therapeutic tool for treating human diseases.

Exploring beyond Common Cell Death Pathways in Oral Cancer: A Systematic Review

Oral squamous cell carcinoma (OSCC) is the most common and lethal type of head and neck cancer in the world. Variable response and acquisition of resistance to traditional therapies show that it is essential to develop novel strategies that can provide better outcomes for the patient. Understanding of cellular and molecular mechanisms of cell death control has increased rapidly in recent years. Activation of cell death pathways, such as the emerging forms of non-apoptotic programmed cell death, including ferroptosis, pyroptosis, necroptosis, NETosis, parthanatos, mitoptosis and paraptosis, may represent clinically relevant novel therapeutic opportunities. This systematic review summarizes the recently described forms of cell death in OSCC, highlighting their potential for informing diagnosis, prognosis and treatment. Original studies that explored any of the selected cell deaths in OSCC were included. Electronic search, study selection, data collection and risk of bias assessment tools were realized. The literature search was carried out in four databases, and the extracted data from 79 articles were categorized and grouped by type of cell death. Ferroptosis, pyroptosis, and necroptosis represented the main forms of cell death in the selected studies, with links to cancer immunity and inflammatory responses, progression and prognosis of OSCC. Harnessing the potential of these pathways may be useful in patient-specific prognosis and individualized therapy. We provide perspectives on how these different cell death types can be integrated to develop decision tools for diagnosis, prognosis, and treatment of OSCC.

Unraveling the role of miRNAs in the diagnosis, progression, and drug resistance of oral cancer

Oral cancer (OC) is a widely observed neoplasm on a global scale. Over time, there has been an increase in both its fatality and incidence rates. Oral cancer metastasis is a complex process that involves a number of cellular mechanisms, including invasion, migration, proliferation, and escaping from malignant tissue through either lymphatic or vascular channels. MicroRNAs (miRNAs) are a crucial class of short non-coding RNAs recognized as significant modulators of diverse cellular processes and exert a pivotal influence on the carcinogenesis pathway, functioning either as tumor suppressors or as oncogenes. It has been shown that microRNAs (miRNAs) have a role in metastasis at several stages, including epithelial-mesenchymal transition, migration, invasion, and colonization. This regulation is achieved by targeting key genes involved in these pathways by miRNAs. This paper aims to give a contemporary analysis of OC, focusing on its molecular genetics. The current literature and emerging advancements in miRNA dysregulation in OC are thoroughly examined. This project would advance OC diagnosis, prognosis, therapy, and therapeutic implications.

Inflammasome pathway in kidney transplantation

Kidney transplantation is the best available renal replacement therapy for patients with end-stage kidney disease and is associated with better quality of life and patient survival compared with dialysis. However, despite the significant technical and pharmaceutical advances in this field, kidney transplant recipients are still characterized by reduced long-term graft survival. In fact, almost half of the patients lose their allograft after 15-20 years. Most of the conditions leading to graft loss are triggered by the activation of a large immune-inflammatory machinery. In this context, several inflammatory markers have been identified, and the deregulation of the inflammasome (NLRP3, NLRP1, NLRC4, AIM2), a multiprotein complex activated by either whole pathogens (including fungi, bacteria, and viruses) or host-derived molecules, seems to play a pivotal pathogenetic role. However, the biological mechanisms leading to inflammasome activation in patients developing post-transplant complications (including, ischemia-reperfusion injury, rejections, infections) are still largely unrecognized, and only a few research reports, reviewed in this manuscript, have addressed the association between abnormal activation of this pathway and the onset/development of major clinical effects. Finally, the regulation of the inflammasome machinery could represent in future a valuable therapeutic target in kidney transplantation.

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.

NLRP3 inflammasome-induced pyroptosis in digestive system tumors

Programmed cell death (PCD) refers to cell death in a manner that depends on specific genes encoding signals or activities. PCD includes apoptosis, pyroptosis, autophagy and necrosis (programmed necrosis). Among these mechanisms, pyroptosis is mediated by the gasdermin family and is accompanied by inflammatory and immune responses. When pathogens or other danger signals are detected, cytokine action and inflammasomes (cytoplasmic multiprotein complexes) lead to pyroptosis. The relationship between pyroptosis and cancer is complex and the effect of pyroptosis on cancer varies in different tissue and genetic backgrounds. On the one hand, pyroptosis can inhibit tumorigenesis and progression; on the other hand, pyroptosis, as a pro-inflammatory death, can promote tumor growth by creating a microenvironment suitable for tumor cell growth. Indeed, the NLRP3 inflammasome is known to mediate pyroptosis in digestive system tumors, such as gastric cancer, pancreatic ductal adenocarcinoma, gallbladder cancer, oral squamous cell carcinoma, esophageal squamous cell carcinoma, in which a pyroptosis-induced cellular inflammatory response inhibits tumor development. The same process occurs in hepatocellular carcinoma and some colorectal cancers. The current review summarizes mechanisms and pathways of pyroptosis, outlining the involvement of NLRP3 inflammasome-mediated pyroptosis in digestive system tumors.

A comprehensive review on RNA interference-mediated targeting of interleukins and its potential therapeutic implications in colon cancer

Colon cancer is the world's fourth leading cause of death. It is cancer of the latter part of the large intestine, i.e. the colon. Chronic inflammation over a long period also leads to the development of cancer. Cancer in the colon region is arduous to diagnose and is detected at a later stage when it metastasizes to other parts of the body like the liver, lungs, peritoneum, etc. Colon cancer is a great example of solid tumours associated with chronic inflammation. Although conventional therapies are effective, they lose their effectiveness beyond a certain point. Relapse of the disease occurs frequently. RNA interference (RNAi) is emerging as a great tool to specifically attack the cancer cells of a target site like the colon. RNAi deals with epigenetic changes made in the defective cells which ultimately leads to their death without harming the healthy cells. In this review, two types of epigenetic modulators have been considered, namely siRNA and miRNA, and their effect on interleukins. Interleukins, a class of cytokines, are major inflammatory responses of the body that are released by immune cells like leukocytes and macrophages. Some of these interleukins are pro-inflammatory, thereby promoting inflammation which eventually causes cancer. RNAi can prevent colon cancer by inhibiting pro-inflammatory interleukins.

MiR-223-3p attenuates the migration and invasion of NSCLC cells by regulating NLRP3

Lung cancer is the malignant tumor with high invasion and metastasis, which seriously threatens public health. Previous study showed that NLRP3 could promote the occurrence of lung tumors in B(a)P-induced mice. MicroRNAs are closely related to the progression and metastasis of lung cancer by regulating target genes. However, which miRNAs affect the migration and invasion of lung cancer cells through regulating NLRP3 remains poorly defined. In this study, the miRNAs targeting NLRP3 were selected from TargetScan and miRDB database and finally miR-223-3p was chosen due to the consistent expression in both A549 and H520 cells. Then, the migration and invasion of lung cancer cells were detected with miR-223-3p mimic and inhibitor using Transwell assay, at the same time the expression of NLRP3, cleaved caspase-1, IL-1β and IL-18 was determined using Western Blot and immunohistochemistry assay. Our data demonstrated that miR-223-3p was upregulated in both A549 and H520 cells. Furthermore, the migration and invasion of A549 and H520 cells were promoted after inhibiting miR-223-3p. Besides, the levels of NLRP3, cleaved caspase-1, IL-1β and IL-18 were increased in the two lung cancer cells. And the corresponding results were contrary in miR-223-3p mimic group. Taken together, miR-223-3p attenuates the migration and invasion of NSCLC cells by regulating NLRP3, which provides evidence for the prevention and targeted treatment of NSCLC.

Changes in the Expression of miRNA Isoforms and Their Targets in HT-29 Cells after Hypoxic Exposure

Tumor hypoxia is one of the main causes of progression and metastasis of colorectal cancer. Changes in the expression of miRNA responsible for post-translation regulation of gene expression is an important molecular mechanism of cell response to hypoxia. We performed sequencing of miRNA and mRNA of human colorectal adenocarcinoma HT-29 cells treated with two chemical agents mimicking hypoxia: cobalt (II) chloride and oxyquinoline. Bioinformatics analysis revealed differentially expressed miRNA isoforms (hsa-miR-210-3p|0, hsa-miR- 22-3p|0, hsa-let-7a-3p|0, hsa-miR-615-3p|0, and hsa-miR-4521|0) and their targets that changed their expression in both models of hypoxia. Thus, we identified new regulatory mechanisms of cell response to hypoxia.

Non-coding RNAs Regulate the Pathogenesis of Aortic Dissection

Aortic dissection (AD) is a fatal cardiovascular disease. It is caused by a rupture of the aortic intima or bleeding of the aortic wall that leads to the separation of different aortic wall layers. Patients with untreated AD have a mortality rate of 1–2% per hour after symptom onset. Therefore, effective biomarkers and therapeutic targets are needed to reduce AD-associated mortality. With the development of molecular technology, researchers have begun to explore the pathogenesis of AD at gene and protein levels, and have made some progress, but the pathogenesis of AD remains unclear. Non-coding RNAs, such as microRNAs, lncRNAs, and circRNAs, have been identified as basic regulators of gene expression and are found to play a key role in the pathogenesis of AD. Thus, providing a theoretical basis for developing these non-coding RNAs as clinical biomarkers and new therapeutic targets for AD in the future. Previous studies on the pathogenesis of AD focused on miRNAs, but recently, there have been an increasing number of studies that explore the role of lncRNAs, and circRNAs in AD. This review summarizes the existing knowledge on the roles of various non-coding RNAs in the pathogenesis of AD, discusses their potential role as clinical biomarkers and therapeutic targets, states the limitations of existing evidence, and recommends future avenues of research on the pathogenesis of AD.

Plant-RNA in Extracellular Vesicles: The Secret of Cross-Kingdom Communication

The release of extracellular vesicles (EVs) is a common language, used by living organisms from different kingdoms as a means of communication between them. Extracellular vesicles are lipoproteic particles that contain many biomolecules, such as proteins, nucleic acids, and lipids. The primary role of EVs is to convey information to the recipient cells, affecting their function. Plant-derived extracellular vesicles (PDEVs) can be isolated from several plant species, and the study of their biological properties is becoming an essential starting point to study cross-kingdom communication, especially between plants and mammalians. Furthermore, the presence of microRNAs (miRNAs) in PDEVs represents an interesting aspect for understanding how PDEVs can target the mammalian genes involved in pathological conditions such as cancer, inflammation, and oxidative stress. In particular, this review focuses on the history of PDEVs, from their discovery, to purification from various matrices, and on the functional role of PDEV-RNAs in cross-kingdom interactions. It is worth noting that miRNAs packaged in PDEVs can be key modulators of human gene expression, representing potential therapeutic agents.

lncRNA THAP7-AS1, transcriptionally activated by SP1 and post-transcriptionally stabilized by METTL3-mediated m6A modification, exerts oncogenic properties by improving CUL4B entry into the nucleus

Long noncoding RNAs (lncRNAs) are dysregulated in different cancer types, and thus have emerged as important regulators of the initiation and progression of human cancers. However, the biological functions and the underlying mechanisms responsible for their functions in gastric cancer (GC) remain poorly understood. Here, by lncRNA microarray, we identified 1414 differentially expressed lncRNAs, among which THAP7-AS1 was significantly upregulated in GC tissues compared with non-tumorous gastric tissues. High expression of THAP7-AS1 was correlated with positive lymph node metastasis and poorer prognosis. SP1, a transcription factor, could bind directly to the THAP7-AS1 promoter region and activate its transcription. Moreover, the m6A modification of THAP7-AS1 by METTL3 enhanced its expression depending on the "reader" protein IGF2BP1-dependent pathway. THAP7-AS1 promoted GC cell progression. Mechanistically, THAP7-AS1 interacted with the 1-50 Amino Acid Region (nuclear localization signal) of CUL4B through its 1-442 nt Sequence, and it promoted interaction between nuclear localization signal (NLS) and importin α1, and improved the CUL4B protein entry into the nucleus, repressing miR-22-3p and miR-320a expression by CUL4B-catalyzed H2AK119ub1 and the EZH2-mediated H3K27me3, subsequently activating PI3K/AKT signaling pathway to promote GC progression. Moreover, LV-sh-THAP7-AS1 treatment could suppress GC growth, invasion and metastasis, indicating that THAP7-AS1 may act as a promising molecular target for GC therapies. Taken together, our results show that THAP7-AS1, transcriptionally activated by SP1 and then modified by METTL3-mediated m6A, exerts oncogenic functions, by promoting interaction between NLS and importin α1 and then improving the CUL4B protein entry into the nucleus to repress the transcription of miR-22-3p and miR-320a.

Nrf2 in the Field of Dentistry with Special Attention to NLRP3

The aim of this review article was to summarize the functional implications of the nuclear factor E2-related factor or nuclear factor (erythroid-derived 2)-like 2 (Nrf2), with special attention to the NACHT (nucleotide-binding oligomerization), LRR (leucine-rich repeat), and PYD (pyrin domain) domains-containing protein 3 (NLRP3) inflammasome in the field of dentistry. NLRP3 plays a crucial role in the progression of inflammatory and adaptive immune responses throughout the body. It is already known that this inflammasome is a key regulator of several systemic diseases. The initiation and activation of NLRP3 starts with the oral microbiome and its association with the pathogenesis and progression of several oral diseases, including periodontitis, periapical periodontitis, and oral squamous cell carcinoma (OSCC). The possible role of the inflammasome in oral disease conditions may involve the aberrant regulation of various response mechanisms, not only in the mouth but in the whole body. Understanding the cellular and molecular biology of the NLRP3 inflammasome and its relationship to Nrf2 is necessary for the rationale when suggesting it as a potential therapeutic target for treatment and prevention of oral inflammatory and immunological disorders. In this review, we highlighted the current knowledge about NLRP3, its likely role in the pathogenesis of various inflammatory oral processes, and its crosstalk with Nrf2, which might offer future possibilities for disease prevention and targeted therapy in the field of dentistry and oral health.

MicroRNA-141-3p inhibits the progression of oral squamous cell carcinoma via targeting PBX1 through the JAK2/STAT3 pathway

Oral squamous cell carcinoma (OSCC), which is the most common epithelial malignant neoplasm in the head and neck, is characterized by local infiltration and metastasis of lymph nodes. The five-year survival rate of OSCC remains low despite the advances in clinical methods. miR-141-3p has been shown to activate or inhibit tumorigenesis. However, the effects of miR-141-3p on invasion and migration of OSCC remain unclear. The present study aimed to evaluate the effects of miR-141-3p on invasion, proliferation, and migration in oral squamous cell carcinoma (OSCC). Reverse transcription quantitative PCR, western blotting and immunohistochemistry were used to detect microRNA(miR)-141-3p and pre-B-cell leukaemia homeobox-1 (PBX1) expression in OSCC tissues and cell lines. The luciferase reporter assay was used to detect targets of miR-141-3p in OSCC. MTT, Transwell and wound healing assays were used to determine the cell proliferation and invasive and migratory abilities, respectively. Expression of constitutive phosphorylated (p)-Janus kinase 2 (JAK2) and p-signal transducer and activator of transcription 3 (STAT3) was detected using western blotting in tissues and cells. miR-141-3p expression was decreased in OSCC tissues and cells, while PBX1 protein expression was increased compared with non-cancerous controls. The result from the dual-luciferase reporter assay revealed that PBX1 was the direct target of miR-141-3p in OSCC tissues. Furthermore, miR-141-3p overexpression and PBX1 knockdown could reduce cell invasion, proliferation and migration, and inhibit the JAK2/STAT3 pathway; however, miR-141-3p downregulation had the opposite effects. In addition, silencing of PBX1 using small interfering RNA could weaken the effects of miR-141-3p inhibitor on JAK2/STAT3 pathway and cell progression in CAL27 cells. In summary, the findings from this study indicated that miR-141-3p upregulation could inhibit OSCC cell invasion, proliferation and migration, by targeting PBX1 via the JAK2/STAT3 pathway.

Silencing KLF16 inhibits oral squamous cell carcinoma cell proliferation by arresting the cell cycle and inducing apoptosis

Krüppel-like factor 16 (KLF16), a member of the Krüppel-like factor (KLF) family, has been extensively investigated in multiple cancer types. However, the role of KLF16 in oral squamous cell carcinoma (OSCC) remains unknown. Thus, we conducted this study to investigate its related mechanism. KLF16 expression in OSCC cell lines was quantified by western blotting. Then, OECM1 and OC3 cells were divided into Blank, siCtrl, siKLF16#1 and siKLF16#2 groups. Subsequently, cell proliferation was detected using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assays, cell migration and invasion were detected with wound healing and Transwell assays, and cell cycle distribution and cell apoptosis were detected via flow cytometry. KLF16, p21, CDK4, Cyclin D1 and p-Rb expression was detected by western blotting. Finally, xenograft models were established in nude mice to observe the in vivo effects of KLF16 on OSCC. KLF16 protein expression was upregulated in OSCC cells. Compared to the cells in the Blank group, the OECM1 and OC3 cells in the siKLF16#1 group and siKLF16#2 group exhibited a sharp decrease in proliferation but a remarkable increase in apoptosis. Moreover, the proportion of cells in the G0/G1 phase notably increased and that in the S phase decreased, with evident decreases in cell invasion and migration. Moreover, KLF16, cyclin-dependent kinase 4 (CDK4), Cyclin D1 and p-Rb protein expression was upregulated, but p21 expression was downregulated. The mice in the siKLF16#1 and siKLF16#2 xenograft model groups exhibited slower tumour growth and smaller tumours with evident downregulation of Ki67 expression compared to the mice in the Blank group. KLF16 expression was upregulated in OSCC cells, and interfering with KLF16 led to cell cycle arrest, inhibited OSCC cell growth and promoted cell apoptosis.

Identification and validation of potential novel biomarkers for oral squamous cell carcinoma

Our study aimed to explore potential new diagnostic biomarkers in patients with oral squamous cell carcinoma (OSCC) to find new target molecules involved in the progression of OSCC. Potential novel biomarkers of OSCC were identified using a protein microarray assay. Compared with the healthy control group, there were five proteins (I309, GDF15, AXL, MMP3, and CTACK) in the serum of in situ oral cancer group. However, there were four differentially expressed proteins (MCSF, I309, MMP3, and CTACK) in the serum of the OSCC group. Receiver operating characteristic (ROC) curve analysis results suggested that these six proteins (I309, GDF15, AXL, MMP3, CTACK, and MCSF) had diagnostic value for OSCC. Based on The Cancer Genome Atlas (TCGA) database, we found that only GDF15 expression was associated with the prognosis of OSCC. Subsequently, we verified the expression levels of six proteins in HSC-3 and HaCaT cells, and the results showed that the level of these six proteins was significantly higher in HSC-3 cells than in normal HaCaT cells. Similarly, in the OSCC nude mouse model, the expression levels of these proteins were significantly upregulated in OSCC tumor tissue compared to the normal tissue. GDF15, MMP3, AXL, MCSF, I309, and CTACK may be used as biomarkers for OSCC diagnosis and provide a novel study direction for the treatment of OSCC.

Role of inflammasomes in neuroinflammation after ischemic stroke

Ischemic stroke is a devastating disease for which there is no effective medical treatment. In the era of extensive reperfusion strategies, established neuroprotectant candidates and novel therapeutic drugs with better targets are promising for treatment of acute ischemic stroke. Such targets include the inflammasome pathway, which contributes significantly to the pathogenesis of ischemic stroke. Following ischemic stroke, damage-associated molecular patterns from damaged cells activate inflammasomes, incur inflammatory responses, and induce cell death. Therefore, inhibiting inflammasome pathways has great promise for treatment of ischemic stroke. However, the efficacy and safety of inflammasome inhibitors remain controversial, and better upstream targets are needed for effective modulation. Herein, the roles of the inflammasome in ischemic injury caused by stroke are reviewed and the potential of neuroprotectants targeting the inflammasome is discussed.

Overcoming Immunotherapy Resistance by Targeting the Tumor-Intrinsic NLRP3-HSP70 Signaling Axis

Simple Summary

The tumor-intrinsic NLRP3 inflammasome is a newly recognized player in the regulation of tumor-directed immune responses and promises to provide fresh insight into how tumors respond to immunotherapy. This brief review discusses recent data describing how activation of the tumor-intrinsic NLRP3 inflammasome contributes to immune evasion and what this pathway may provide to the field of immuno-oncology both in terms of pharmacologic targets capable of boosting responses to checkpoint inhibitor therapies and predictive biomarkers indicating which tumors may be most susceptible to these new therapeutic strategies.

Abstract

The tumor-intrinsic NOD-like receptor family, pyrin-domain-containing-3 (NLRP3) inflammasome, plays an important role in regulating immunosuppressive myeloid cell populations in the tumor microenvironment (TME). While prior studies have described the activation of this inflammasome in driving pro-tumorigenic mechanisms, emerging data is now revealing the tumor NLRP3 inflammasome and the downstream release of heat shock protein-70 (HSP70) to regulate anti-tumor immunity and contribute to the development of adaptive resistance to anti-PD-1 immunotherapy. Genetic alterations that influence the activity of the NLRP3 signaling axis are likely to impact T cell-mediated tumor cell killing and may indicate which tumors rely on this pathway for immune escape. These studies suggest that the NLRP3 inflammasome and its secreted product, HSP70, represent promising pharmacologic targets for manipulating innate immune cell populations in the TME while enhancing responses to anti-PD-1 immunotherapy. Additional studies are needed to better understand tumor-specific regulatory mechanisms of NLRP3 to enable the development of tumor-selective pharmacologic strategies capable of augmenting responses to checkpoint inhibitor immunotherapy while minimizing unwanted off-target effects. The execution of upcoming clinical trials investigating this strategy to overcome anti-PD-1 resistance promises to provide novel insight into the role of this pathway in immuno-oncology.

Non-coding RNAs: The key regulators in NLRP3 inflammasome-mediated inflammatory diseases

Inflammasomes are multiprotein complexes responding to various microbes and endogenous danger signals, contributing to initiating the innate protective response of inflammatory diseases. NLRP3 inflammasome is a crucial regulator of pro-inflammatory cytokines (IL-1β and IL-18) production through activating caspase-1. Non-coding RNAs (ncRNAs) are a class of RNA transcripts lacking the ability to encode peptides or proteins. Its dysregulation leads to the development and progression of inflammation in diseases. Recently, accumulating evidence has indicated that NLRP3 inflammasome activation could be modulated by ncRNAs (lncRNAs, miRNAs, and circRNAs) in a variety of inflammatory diseases. This review focuses on the substantial role and function of ncRNAs in the NLRP3 inflammasome activation, providing novel insight for the future therapeutic approach of inflammatory diseases.

Bitter melon derived extracellular vesicles enhance the therapeutic effects and reduce the drug resistance of 5-fluorouracil on oral squamous cell carcinoma

Background

Plant-derived extracellular vesicles (PDEVs) have been exploited for cancer treatment with several benefits. Bitter melon is cultivated as a vegetable and folk medicine with anticancer and anti-inflammatory activities. 5-Fluorouracil (5-FU) is widely used for cancer treatment. However, 5-FU-mediated NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammation activation induced the resistance of oral squamous cell carcinoma (OSCC) cells to 5-FU. In this study, we explored the potential of bitter melon-derived extracellular vesicles (BMEVs) for enhancing the therapeutic efficacy and reduce the resistance of OSCC to 5-FU.

Results

Herein, we demonstrate that bitter melon derived extracellular vesicles (BMEVs), in addition to their antitumor activity against OSCC have intrinsic anti-inflammatory functions. BMEVs induced S phase cell cycle arrest and apoptosis. Apoptosis induction was dependent on reactive oxygen species (ROS) production and JUN protein upregulation, since pretreatment with N-acetyl cysteine or catechin hydrate could prevent apoptosis and JUN accumulation, respectively. Surprisingly, BMEVs significantly downregulated NLRP3 expression, although ROS plays a central role in NLRP3 activation. We further assessed the underlying molecular mechanism and proposed that the RNAs of BMEVs, at least in part, mediate anti-inflammatory bioactivity. In our previous studies, NLRP3 activation contributed to the resistance of OSCC cells to 5-FU. Our data clearly indicate that BMEVs could exert a remarkable synergistic therapeutic effect of 5-FU against OSCC both in vitro and in vivo. Most notably, NLRP3 downregulation reduced the resistance of OSCC to 5-FU.

Conclusions

Together, our findings demonstrate a novel approach to enhance the therapeutic efficacy and reduce the drug resistance of cancer cells to chemotherapeutic agents, which provides proof-of-concept evidence for the future development of PDEVs-enhanced therapy.

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00995-1.

NLRP3 Overexpression Associated With Poor Prognosis and Presented as an Effective Therapeutic Target in Osteosarcoma

Despite the development of diagnostic and treatment strategies, the survival outcome of patients with osteosarcoma remains poor. Nod-like receptor protein 3 (NLRP3) plays a crucial role in the inflammasome pathway, which is related to the progression of various tumors. However, the effect of NLRP3 on osteosarcoma has not yet been well explored. Our study aimed to investigate the role of NLRP3 in the malignant biological behavior of osteosarcoma as well as its therapeutic value. Immunohistochemistry was applied to investigate the NLRP3 expression in osteosarcoma and osteochondroma specimens. Cell Counting Kit-8, colony formation, wound healing, transwell, and flow cytometry assays were used to explore the contribution of NLRP3 to the proliferation, migration, invasion, apoptosis and cell cycle distribution of osteosarcoma cells in vitro. Western blot was performed to evaluate the expression of NLRP3 and the related proteins in osteosarcoma cell lines after the blockade of NLRP3 using CY-09 and lentivirus intervention. Furthermore, tumor formation assay was used to analyze the effect of NLRP3 on the growth of osteosarcoma in vivo. The results showed that the NLRP3 protein was overexpressed in osteosarcoma, which was independently correlated with the poor prognosis of patients. Moreover, NLRP3 suppression by the inhibitor of CY-09 or lentivirus-induced gene knockdown inhibited the cell proliferation, migration, invasion and promoted the cell apoptosis and G1 cell cycle arrest in osteosarcoma via targeting the inflammasome pathway. Our in vivo results confirmed that the inhibition of NLRP3 suppressed the tumor formation of osteosarcoma. In conclusion, NLRP3 may be regarded as an independent prognostic biomarker and a potential therapeutic target for osteosarcoma.

Targeting the NLRP3 Inflammasome as a New Therapeutic Option for Overcoming Cancer

Inflammasomes are multiprotein complexes that regulate the maturation and secretion of the proinflammatory cytokines interleukin-1beta (IL-1β and interleukin-18 (IL-18) in response to various intracellular stimuli. As a member of the inflammasomes family, NLRP3 is the most studied and best characterized inflammasome and has been shown to be involved in several pathologies. Recent findings have made it increasingly apparent that the NLRP3 inflammasome may also play a central role in tumorigenesis, and it has attracted attention as a potential anticancer therapy target. In this review, we discuss the role of NLRP3 in the development and progression of cancer, offering a detailed summary of NLRP3 inflammasome activation (and inhibition) in the pathogenesis of various forms of cancer. Moreover, we focus on the therapeutic potential of targeting NLRP3 for cancer therapy, emphasizing how understanding NLRP3 inflammasome-dependent cancer mechanisms might guide the development of new drugs that target the inflammatory response of tumor-associated cells.

MicroRNA-22 in female malignancies: Focusing on breast, cervical, and ovarian cancers

MicroRNAs (miRNAs), a novelty-defined class of regulatory genes, have revolutionized principles of classical bimolecular. These RNAs regulate the expression of a gene through inhibition of translational initiation or targeting mRNAs for degradation. MiRNAs act in several biological operations, including proliferation, differentiation, and cell death, and their expression is often abnormal in human diseases such as cancer. In recent years, miR-22 has attracted much attention from researchers. Its expression is downregulated in female malignancies such as breast, cervical, and ovarian cancers, exhibiting that miR-22 plays a tumor-suppressive function in these cancers. Also, different reports exist about the involvement of miR-22 in non-tumor diseases. In the present review, we report the results of performed studies on the potential roles of miR-22 in female malignancies with a focus on breast, cervical, and ovarian cancers. Also, we summary its predicted target genes in various cancers. In conclusion, it is effective for researchers to understand the role of miR-22 in different cellular operations.

Roles of microRNAs in Regulating Cancer Stemness in Head and Neck Cancers

Head and neck squamous cell carcinomas (HNSCCs) are epithelial malignancies with 5-year overall survival rates of approximately 40-50%. Emerging evidence indicates that a small population of cells in HNSCC patients, named cancer stem cells (CSCs), play vital roles in the processes of tumor initiation, progression, metastasis, immune evasion, chemo-/radioresistance, and recurrence. The acquisition of stem-like properties of cancer cells further provides cellular plasticity for stress adaptation and contributes to therapeutic resistance, resulting in a worse clinical outcome. Thus, targeting cancer stemness is fundamental for cancer treatment. MicroRNAs (miRNAs) are known to regulate stem cell features in the development and tissue regeneration through a miRNA-target interactive network. In HNSCCs, miRNAs act as tumor suppressors and/or oncogenes to modulate cancer stemness and therapeutic efficacy by regulating the CSC-specific tumor microenvironment (TME) and signaling pathways, such as epithelial-to-mesenchymal transition (EMT), Wnt/β-catenin signaling, and epidermal growth factor receptor (EGFR) or insulin-like growth factor 1 receptor (IGF1R) signaling pathways. Owing to a deeper understanding of disease-relevant miRNAs and advances in in vivo delivery systems, the administration of miRNA-based therapeutics is feasible and safe in humans, with encouraging efficacy results in early-phase clinical trials. In this review, we summarize the present findings to better understand the mechanical actions of miRNAs in maintaining CSCs and acquiring the stem-like features of cancer cells during HNSCC pathogenesis.

MicroRNAs as Modulators of Oral Tumorigenesis-A Focused Review

Oral cancers constitute the majority of head and neck tumors, with a relatively high incidence and poor survival rate in developing countries. While the five-year survival rates of the oral cancer patients have increased to 65%, the overall survival for advanced stages has been at 27% for the past ten years, emphasizing the necessity for further understanding the etiology of the disease, diagnosis, and formulating possible novel treatment regimens. MicroRNAs (miRNAs), a family of small non-coding RNA, have emerged as master modulators of gene expression in various cellular and biological process. Aberrant expression of these dynamic molecules has been associated with many human diseases, including oral cancers. The deregulated miRNAs have been shown to control various oncogenic processes, including sustaining proliferative signaling, evading growth suppressors, resisting cell death activating invasion and metastasis, and inducing angiogenesis. Hence, the aberrant expression of miRNAs associated with oral cancers, makes them potential candidates for the investigation of functional markers, which will aid in the differential diagnosis, prognosis, and development of novel therapeutic regimens. This review presents a holistic insight into our understanding of the role of miRNAs in regulating various hallmarks of oral tumorigenesis.

Long non-coding RNA OIP5-AS1 contributes to cisplatin resistance of oral squamous cell carcinoma through the miR-27b-3p/TRIM14 axis

Oral squamous cell carcinoma (OSCC) accounts for 90% of oral cavity cancer types, but the overall prognosis for patients with OSCC remains unfavorable. Cisplatin (DDP) is an effective drug in OSCC treatment, but DDP resistance weakens its therapeutic effect. Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) can trigger DDP resistance. The purpose of the current study was to explore the role and mechanism ofOIP5-AS1 in OSCC DDP resistance. In the present study, the expression levels of OIP5-AS1, microRNA (miR)-27b-3p and tripartite motif-containing 14 (TRIM14) were detected by reverse transcription-quantitative PCR. DDP resistance was measured using an MTT assay. Moreover, cell proliferation, migration and invasion were assessed by MTT, Transwell, and Matrigel assays. Protein expression levels of TRIM14, E-cadherin, N-cadherin and Vimentin were detected by western blot analysis. Putative binding sites between miR-27b-3p andOIP5-AS1 or TRIM14werepredicted with starBase and verified using a dual-luciferase reporter assay. The role of OIP5-AS1 in DDP resistance of OSCC in vivo was measured using a xenograft tumor model. It was observed that OIP5-AS1 was upregulated in DDP-resistant OSCC cells, and the knockdown of OIP5-AS1 improved DDP sensitivity in DDP-resistant OSCC cells. The present study identified that miR-27b-3p was a target of OIP5-AS1. Furthermore, miR-27b-3p silencing reversed the effect of OIP5-AS1 knockdown on DDP sensitivity in DDP-resistant OSCC cells. TRIM14was shown to be a direct target of miR-27b-3p, and TRIM14 overexpression abolished the effect of miR-27b-3p on DDP sensitivity in DDP-resistant OSCC cells. The results suggested that OIP5-AS1 increased TRIM14 expression by sponging miR-27b-3p. In addition, OIP5-AS1 knockdown enhanced DDP sensitivity of OSCC in vivo. Data from the present study indicated that OIP5-AS1 may improve DDP resistance through theupregulationTRIM14 mediated bymiR-27b-3p, providing a possible therapeutic strategy for OSCC treatment.

Alteration of Pituitary Tumor Transforming Gene 1 by MicroRNA-186 and 655 Regulates Invasion Ability of Human Oral Squamous Cell Carcinoma

Background: Pituitary tumor-transforming gene 1 (PTTG1) was recently shown to be involved in the progression as well as the metastasis of cancers. However, their expression and function in the invasion of oral squamous cell carcinoma (SCC) remain unclear. Methods: The expressions of PTTG1 and PTTG1-targeted miRNA in oral SCC cell lines and their invasion capability depended on PTTG1 expression were analyzed by quantitative RT-PCR, Western blots, the transwell insert system and Zymography. Results: Invasion abilities were decreased in oral SCC cells treated with siRNA-PTTG1. When PTTG1 were downregulated in oral SCC cells treated with microRNA-186 and -655 inhibited their invasion abilities via MMP-9 activity. Conclusions: These results indicate that alteration of expression of PTTG1 in oral SCC cells by newly identified microRNA-186 and -655 can regulate invasion activity. Therefore, these data offer new insights into further understanding PTTG1 function in oral SCC and should provide new strategies for diagnostic markers for oral SCC.

MiR-590-5p regulates cell proliferation, apoptosis, migration and invasion in oral squamous cell carcinoma by targeting RECK

OBJECTIVE

To discover the role of miR-590-5p in oral squamous cell carcinoma (OSCC) progression and the corresponding mechanism via the targeting RECK.

METHODS

OSCC (n=85) and normal oral tissues (n=60) were collected to quantify the miR-590-5p expression by using qRT-PCR. Then SCC-15 and OEC-M1 cells were selected and divided into Mock, inhibitor NC, miR-590-5p inhibitor, si-RECK and miR-590-5p inhibitor + si-RECK groups. Dual-luciferase reporter gene assay was used to verify if miR-590-5p could target RECK. The biological behaviors of OSCC cells were evaluated by MTT, Wound-healing, Transwell and Flow cytometry. The expression of miR-590-5p and RECK was measured by qRT-PCR and Western blotting , respectively.

RESULTS

Overexpression of miR-590-5p was found in OSCC tissues. The expression of miR-590-5p was significantly associated with the clinical TNM stage, differentiation degree, and lymph node metastasis of OSCC. RECK was identified as a direct target of miR-590-5p. Compared with the Mock group, cells in the miR-590-5p inhibitor group were decreased in terms of proliferation, invasion, and migration, and increased in cell apoptosis, accompanied by down-regulated miR-590-5p, Bcl-2/Bax and MMP-9, and up-regulated RECK. By contrast, si-RECK group presented completely opposite changes, and si-RECK reversed the inhibitory effect of miR-590-5p inhibitor on the OSCC cell growth.

CONCLUSION

MiR-590-5p expression was obviously increased in OSCC, and inhibiting miR-590-5p enhanced the expression of its target gene RECK, thereby suppressing proliferation, migration and invasion of OSCC cells and promoting apoptosis of OSCC cells.

Modulatory mechanisms of NLRP3: Potential roles in inflammasome activation

The NLRP3 inflammasome regulates innate immune and inflammatory responses by promoting pro-inflammatory cytokines such as IL-18 and IL-1β. NLRP3 is one of the main factors restricting the activation of the inflammasome, which is closely related to the abundance and localization of NLRP3. A substantial number of studies have focused on specifically targeting NLRP3 to develop inhibitors against NLRP3 inflammasome. Here, we succinctly review the regulation of NLRP3 expression at DNA/chromosome, transcriptional, post-transcriptional, and translation levels. These are critical for the fine regulation of the NLRP3 inflammasome.

miR-124-3p Regulates FGF2-EGFR Pathway to Overcome Pemetrexed Resistance in Lung Adenocarcinoma Cells by Targeting MGAT5

Objective

To investigate whether miR-124-3p regulates the fibroblast growth factor 2 (FGF2)–epidermal growth factor receptor (EGFR) pathway by targeting MGAT5 to affect the pemetrexed resistance in lung adenocarcinoma cells.

Methods

PC9-MTA and H1993-MTA anti-pemetrexed lung adenocarcinoma cell lines were constructed. The cell viability of anti-pemetrexed and parent lung adenocarcinoma cells was analyzed using MTS assay and reverse transcription PCR to determine the expression of miR-124-3p. CCK8 assay, colony formation assay, and flow cytometry were used to determine cells’ proliferation and apoptosis. FGF2–EGFR signaling pathway-related proteins and MGAT5 protein expression were quantified by Western blotting. The target relationship between miR-124-3p and MGAT5 was verified by double luciferase assay. A nude mouse model with a transplanted tumor was established using the anti-pemetrexed lung adenocarcinoma cells. Tumor volume and weight were determined, and the apoptosis of tumor cells was observed.

Results

The half-maximal inhibitory concentration of pemetrexed in anti-pemetrexed lung adenocarcinoma cells was higher than that in parent lung adenocarcinoma cells, and the expression of miR-124-3p in the anti-pemetrexed cells was lower than that of the parent cells. In the miR-124-3p overexpression group, MGAT5 silencing group, and miR-124-3p+MGAT5 overexpression group, compared with the control group, the proliferation ability of cells and tumors was markedly reduced; their apoptosis rates were increased significantly; expression levels of FGF2 and p-EGFR/EGFR were decreased; and the growth rate and tumor volume and mass were reduced; however, the opposite results were obtained in the miR-124-3p silencing group (p<0.05).

Conclusion

miR-124-3p may inhibit the FGF2–EGFR pathway by targeting MGAT5 to decrease pemetrexed resistance in lung adenocarcinoma cells.

Inflammasomes in cancer: Effect of epigenetic and autophagic modulations

Tumour-promoting inflammation is a critical hallmark in cancer development, and inflammasomes are well-known regulators of inflammatory processes within the tumour microenvironment. Different inflammasome components along with the adaptor, apoptosis-associated speck-like protein containing caspase activation and recruitment domain (ASC), and the effector, caspase-1, have a significant influence on tumorigenesis but in a tissue-specific and stage-dependent manner. The downstream products of inflammasome activation, that is the proinflammatory cytokines such as IL-1β and IL-18, regulate tissue homeostasis and induce antitumour immune responses, but in contrast, they can also favour cancer growth and proliferation by directing various oncogenic signalling pathways in cancer cells. Moreover, different epigenetic mechanisms, including DNA methylation, histone modification and noncoding RNAs, control inflammasomes and their components by regulating gene expression during cancer progression. Furthermore, autophagy, a master controller of cellular homeostasis, targets inflammasome-induced carcinogenesis by maintaining cellular homeostasis and removing potential cancer risk factors that promote inflammasome activation in support of tumorigenesis. Here, in this review, we summarize the effect of inflammasome activation in cancers and discuss the role of epigenetic and autophagic regulatory mechanisms in controlling inflammasomes. A proper understanding of the interactions among these key processes will be useful for developing novel therapeutic regimens for targeting inflammasomes in cancer.

MicroRNA-139 Suppresses the Tumorigenicity of Triple Negative Breast Cancer Cells by Targeting SOX8

Purpose

The effects of miR-139 on the tumorigenicity of triple negative breast cancer (TNBC) and the underlying mechanisms were investigated.

Methods

Normal human breast epithelial (MCF-10A) and TNBC cell lines (HCC1806 and BT549) were used for microRNA (miR)-139 overexpression, SOX8 overexpression, and knockdown studies as in vitro models of TNBC. The expression of SOX8 and miR-139 was detected by reverse transcription-polymerase chain reaction. CCK8 and clone formation assays were used to evaluate cell proliferation ability. Transwell assays and flow cytometry were used to test cell migration and apoptosis, respectively. Cell tumorigenicity was examined by tumor sphere formation assays. The interaction between miR-139 and SOX8 was examined by dual-luciferase reporter assays. The expression of SOX8, cleaved caspase-3, and cleaved caspase-9 was analyzed by Western blotting. The findings were validated in vivo using a nude mouse transplanted tumor model.

Results

SOX8 expression was higher (P < 0.05) and miR-139 expression was lower (P < 0.05) in HCC1806 and BT549 cells than in MCF-10A cells. SOX8 overexpression significantly enhanced cell proliferation and migration, reduced the rate of cell apoptosis, and increased tumor sphere formation (P < 0.05) compared with the control group, whereas SOX8 knockdown had the opposite effect (P < 0.05). Overexpression of miR-139 markedly decreased cell proliferation and migration, increased cell apoptosis in vitro, and decreased tumor angiogenesis and volume in vivo (P < 0.05).

Conclusion

miR-139 suppressed the tumorigenicity of TNBC cells by targeting SOX8.

miR-22 Suppresses Tumor Invasion and Metastasis in Colorectal Cancer by Targeting NLRP3

Purpose

This study aimed to investigate the effects of microRNA (miR)-22 on biological behaviors of colon cancer cells and to explore the relationship between miR-22 and NLRP3.

Materials and Methods

First, human colon cancer HCT116 cells were transfected with a miR-22 mimic, miR-22 inhibitor, control mimic, and control inhibitor, respectively. CCK8, colony formation, and transwell assays were performed to observe cell proliferation, migration, and invasion. Western blotting was used to analyze the expression of recombinant NLRP3 (NLR family, pyrin domain-containing protein 3) and epithelial–mesenchymal transformation (EMT)-related proteins. The target relationship between miR-22 and NLRP3 was verified by double luciferase report. Second, an NLRP3 inhibitor and NLRP3 mimic were transfected into HCT116 cells, and the biological behaviors and EMT-related proteins were again observed. Finally, a nude mouse xenograft model was constructed to verify the above results.

Results

In vitro, compared with the control group, administration of the miR-22 mimic significantly decreased proliferation, migration, and invasion of HCT116 cells, whereas the miR-22 inhibitor markedly increased their proliferation and invasion (p<0.05). Levels of NLRP3, interleukin-1β (IL-1β), matrix metalloproteinase-9 (MMP-9), MMP-2, N-cadherin, and vimentin were significantly reduced after miR-22 mimic transfection (p<0.05). Furthermore, silencing of NLRP3, a downstream gene of miR-22 in HCT116 cells, suppressed proliferation, migration, and invasion of HCT116 cells. However, overexpression of NLRP3 weakened the effects of the miR-22 mimic. In vivo, overexpression of miR-22 slowed the growth rate of tumors and reduced Ki-67 expression in tumor tissues compared with the model group (p<0.05). In tumor tissues, overexpression of miR-22 also decreased expression of NLRP3, IL-1β, MMP-9, MMP-2, N-cadherin, and vimentin compared with the model group (p<0.05). Overexpression of NLRP3 weakened the role of miR-22 overexpression in vivo.

Conclusion

miR-22 suppresses cell proliferation, migration, and invasion in colorectal cancer by targeting NLRP3.

miR-22 suppresses cell viability and EMT of ovarian cancer cells via NLRP3 and inhibits PI3K/AKT signaling pathway

PURPOSE

miR-22 plays a great role in inhibiting cell growth, metastasis and enhanced cell apoptosis in several cancers. The purpose of this study was to investigate the functions of miR-22 in ovarian cancer.

METHODS

The proliferative ability was measured using CCK-8 assay. The protein expression associated with EMT and PI3K/AKT signaling biomarkers were measured by western blot. Luciferase assay applied to measure the luciferase activity. Kaplan-Meier method was performed to evaluate the overall survival rate of ovarian cancers.

RESULTS

miR-22 was low expressed and NLRP3 was overexpressed in ovarian cancer tissues and cells, and downregulation of miR-22 was associated with poor prognosis. The expression of NLRP3 had a negative correlation with miR-22 expression in ovarian cancer. miR-22 promoted cell viability and EMT through directly binding to the 3'-UTR of NLRP3 mRNA and inhibited PI3K/AKT signaling pathway. NLRP3 partially restored functions of miR-22 on cell proliferation and EMT in ovarian cancer.

CONCLUSION

miR-22 impaired cell viability and EMT by NLRP3 and inhibited PI3K/AKT signaling pathway in ovarian cancer. The newly identified miR-22/NLRP3/PI3K/AKT axis provides novel insight into the pathogenesis of ovarian cancer.

Inflammasome activation and regulation: toward a better understanding of complex mechanisms

Inflammasomes are cytoplasmic multiprotein complexes comprising a sensor protein, inflammatory caspases, and in some but not all cases an adapter protein connecting the two. They can be activated by a repertoire of endogenous and exogenous stimuli, leading to enzymatic activation of canonical caspase-1, noncanonical caspase-11 (or the equivalent caspase-4 and caspase-5 in humans) or caspase-8, resulting in secretion of IL-1β and IL-18, as well as apoptotic and pyroptotic cell death. Appropriate inflammasome activation is vital for the host to cope with foreign pathogens or tissue damage, while aberrant inflammasome activation can cause uncontrolled tissue responses that may contribute to various diseases, including autoinflammatory disorders, cardiometabolic diseases, cancer and neurodegenerative diseases. Therefore, it is imperative to maintain a fine balance between inflammasome activation and inhibition, which requires a fine-tuned regulation of inflammasome assembly and effector function. Recently, a growing body of studies have been focusing on delineating the structural and molecular mechanisms underlying the regulation of inflammasome signaling. In the present review, we summarize the most recent advances and remaining challenges in understanding the ordered inflammasome assembly and activation upon sensing of diverse stimuli, as well as the tight regulations of these processes. Furthermore, we review recent progress and challenges in translating inflammasome research into therapeutic tools, aimed at modifying inflammasome-regulated human diseases.

Investigating the role and mechanism of microRNA-196a in oral squamous cell carcinoma by targeting FOXO1

Oral squamous cell carcinoma (OSCC) is one of the most prevalent malignancies worldwide. MicroRNAs (miRNAs or miRs) serve crucial roles in the development of OSCC. miR-196a is upregulated in various tumors; however, the role of miR-196a in OSCC remains unclear. This present study aimed to determine the role and underlying mechanism of miR-196a in OSCC cells. Reverse transcription-quantitative PCR (RT-qPCR) was used to measure miR-196a levels in OSCC cells. MTT assays were also performed to determine cell proliferation. Cell migration was detected using wound healing assays and transwell assays, and cell apoptosis was analyzed via flow cytometry. The results indicated that the expression of miR-196a was increased in OSCC cells compared with normal oral squamous cells. TargetScan and luciferase reporter assays also confirmed that forkhead box O1 (FOXO1) was a target gene of miR-196a. It was demonstrated that FOXO1 small interfering RNA significantly promoted SCC9 cell proliferation and migration, and inhibited cell apoptosis. Furthermore, inhibition of miR-196a suppressed SCC9 cell proliferation and migration, and induced cell apoptosis. However, all effects of the miR-196a inhibitor were reversed following FOXO1 inhibition. Western blotting and RT-qPCR were subsequently performed to determine the effect of miR-196a on the PI3K/Akt signaling pathway. In the present study, transfection of miR-196a inhibitor suppressed the expression of phosphorylated (p)-PI3K and p-Akt, and enhanced the levels of FOXO1, while inhibition of FOXO1 exerted the opposite effects. Furthermore, it was demonstrated that miR-196a mimic significantly enhanced SCC9 cell proliferation and migration, and inhibited cell apoptosis. In conclusion, the results indicated that miR-196a serve as an oncogene in OSCCs. Downregulation of miR-196a inhibited the malignant biological processes of OSCC cells by targeting FOXO1. The current results may provide a novel therapeutic strategy for the treatment of patients with OSCC.

Effect of microRNA-27b on cisplatin chemotherapy sensitivity of oral squamous cell carcinoma via FZD7 signaling pathway

Effect of microRNA-27b (miR-27b) on cisplatin chemotherapy sensitivity of oral squamous cell carcinoma (OSCC) was investigated to provide a reference for clinical prevention of OSCC cell resistance. The clinical tissues of 34 patients with OSCC-resistant cancer and 28 patients with cisplatin-sensitive OSCC in Nanjing General Hospital were collected. The expression levels of miR-27b and Frizzled-7 (FZD7) in cancer tissues were detected by reverse transcription-quantitative polymerase chain reation (RT-qPCR). After a certain gradient of cisplatin was used to induce stable acquired resistance of OSCC cell line Tca8113/CDDP, a dose of miR-27b was added to construct a cell line overexpressing miR-27b in the drug-resistant cell line. The effect of cisplatin on the proliferation of drug-resistant OSCC cells was detected by colony formation assay. In addition, the scratch test and Transwell formation assay was performed to examine the effect of cisplatin drug stimulation on proliferation and migration of Tca8113/CDDP. Flow cytometry and Hoechst 33258 staining were used to detect the effect of miR-27b on apoptosis of OSCC-resistant cells after cisplatin chemotherapy. The expression level of miR-27b in cancer tissues of patients with drug-resistant OSCC was significantly lower than that of patients with OSCC cisplatin sensitivity (P<0.05). After high expression of miR-27b, the number of clones of drug-resistant OSCC cells after adding cisplatin drugs can be significantly inhibited. The proliferation and migration ability of drug-resistant OSCC was significantly decreased after the addition of cisplatin in miR-27b overexpression (P<0.05). miR-27 mimic enhanced the pro-apoptotic ability of cisplatin drugs (P<0.05). The expression of FZD7 in cisplation-resistant patients was significantly higher (P<0.05). miR-27b significantly inhibited the expression of FZD7 and β-catenin proteins. miR-27b can inhibit the resistance of OSCC to cisplatin drugs, increase apoptosis of cancer cells, and inhibit the proliferation of cancer cells. The mechanism may be related to the inhibition of FZD7/β-catenin signaling pathway activation in drug-resistant cell lines by miR-27b.

MicroRNAs as important regulators of the NLRP3 inflammasome

Inflammasomes are a group of cytosolic multi-protein signaling complexes that regulate maturation of the interleukin (IL)-1 family cytokines IL-1β and IL-18 through activation of inflammatory caspase-1. The NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome is the best characterized and consists of several key components that are assembled and activated in response to different endogenous and exogenous signals. The NLRP3 inflammasome is common to a number of human inflammatory diseases and its targeting may lead to novel anti-inflammatory therapy. NLRP3 inflammasome activation is tightly regulated by different mechanisms especially post-transcriptional modulation via microRNAs (miRNA). MicroRNAs are small endogenous noncoding RNAs that are 21-23 nucleotides in length and control the expression of various genes through binding to the 3'-untranslated regions of the respective mRNA and subsequent post-transcriptional regulation. MicroRNAs have recently been recognized as crucial regulators of the NLRP3 inflammasome. In this review, we summarize the current understanding of the role of miRNAs in the regulation of NLRP3 inflammasome complexes and their impact on the pathogenesis of inflammatory disease processes.

MicroRNA Post-transcriptional Regulation of the NLRP3 Inflammasome in Immunopathologies

Inflammation has a crucial role in protection against various pathogens. The inflammasome is an intracellular multiprotein signaling complex that is linked to pathogen sensing and initiation of the inflammatory response in physiological and pathological conditions. The most characterized inflammasome is the NLRP3 inflammasome, which is a known sensor of cell stress and is tightly regulated in resting cells. However, altered regulation of the NLRP3 inflammasome is found in several pathological conditions, including autoimmune disease and cancer. NLRP3 expression was shown to be post-transcriptionally regulated and multiple miRNA have been implicated in post-transcriptional regulation of the inflammasome. Therefore, in recent years, miRNA based post-transcriptional control of NLRP3 has become a focus of much research, especially as a potential therapeutic approach. In this review, we provide a summary of the recent investigations on the role of miRNA in the post-transcriptional control of the NLRP3 inflammasome, a key regulator of pro-inflammatory IL-1β and IL-18 cytokine production. Current approaches to targeting the inflammasome product were shown to be an effective treatment for diseases linked to NLRP3 overexpression. Although utilizing NLRP3 targeting miRNAs was shown to be a successful therapeutic approach in several animal models, their therapeutic application in patients remains to be determined.

MicroRNA‑199a‑5p functions as a tumor suppressor in oral squamous cell carcinoma via targeting the IKKβ/NF‑κB signaling pathway

MicroRNAs (miRNAs) have been shown to have a significant role in the progression of several types of cancer, including oral squamous cell carcinoma (OSCC). However, the biological function and regulatory mechanisms of miRNAs in OSCC remain to be fully elucidated. The aim of the present study was to investigate the role of miRNAs in OSCC and the relevant mechanism. Using a microarray, it was found that miRNA (miR)-199a-5p was one of the most downregulated miRNAs in OSCC tissues. A low expression of miR-199a-5p was closely associated with tumor differentiation, lymph node metastasis, tumor-node-metastasis stage, and overall survival rate. Functionally, the overexpression of miR-199a-5p suppressed cell proliferation, induced G0/G1 cell cycle arrest, and promoted the apoptosis of Tca8113 and SCC-4 cells. Subsequently, inhibitor of nuclear factor-κB (NF-κB) kinase β (IKKβ), an important regulator of NF-κB activation, was identified as a direct target of miR-199-5p. An inverse correlation was found between miR-199a-5p and IKKβ in tumor tissues. Further investigations revealed that the overexpression of IKKβ efficiently abrogated the influences caused by the overexpression of miR-199a-5p. It was also found that the miR-199a-5p-mediated anticancer effects were dependent on the inhibition of NF-κB activation. These findings indicate that miR-199a-5p functions as a tumor suppressor through regulation of the NF-κB pathway by targeting IKKβ in OSCC.

Role and mechanism of the nod-like receptor family pyrin domain-containing 3 inflammasome in oral disease

OBJECTIVE

To summarize evidence and data from experimental studies regarding the role and mechanism of the Nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in the pathogenesis of several representative oral diseases.

MATERIALS AND METHODS

A literature search of PubMed and EBSCO was performed. The literature was searched using a combination of keywords, e.g., NLRP3 inflammasome, inflammation, microorganisms, oral inflammatory diseases, and oral immunological diseases.

RESULTS

The initiation and activation of the NLRP3 inflammasome are associated with the pathogenesis and progression of several representative oral diseases, including periodontitis, oral lichen planus, dental pulp disease, and oral cavity squamous cell carcinoma.

CONCLUSIONS

The NLRP3 inflammasome plays a crucial role in the progression of inflammatory and adaptive immune responses. The possible role of the NLRP3 inflammasome in several oral diseases, including not only periodontitis and pulpitis but also mucosal diseases and oral cavity squamous cell carcinoma, may involve the aberrant regulation of inflammatory and immune responses. Understanding the cellular and molecular biology of the NLRP3 inflammasome is necessary because the NLRP3 inflammasome may be a potential therapeutic target for the treatment and prevention of oral inflammatory and immunological diseases.

Evidence and perspective for the role of the NLRP3 inflammasome signaling pathway in ischemic stroke and its therapeutic potential (Review)

Ischemic stroke is one of the main causes of death and disablement globally. The NLR family pyrin domain containing 3 (NLRP3) inflammasome is established as a sensor of detecting cellular damage and modulating inflammatory responses to injury during the progress of ischemic stroke. Inhibiting or blocking the NLRP3 inflammasome at different stages, including expression, assembly, and secretion, may have great promise to improve the neurological deficits during ischemic stroke. The current review provides a comprehensive summary of the current understanding in the literature of the molecular structure, expression, and assembly of the NLRP3 inflammasome, and highlights its potential as a novel therapeutic target for ischemic stroke.

MicroRNA-16 functions as a tumor-suppressor gene in oral squamous cell carcinoma by targeting AKT3 and BCL2L2

Aberrant expressions of microRNAs have been reported to be strongly associated with the progression and prognosis of various tumors, including oral squamous cell carcinoma (OSCC). Recent studies on miRNA expression profiling have suggested that microRNA-16 (miR-16) may be dysregulated in OSCC. However, the tumorigenic roles and mechanisms of miR-16 in OSCC are still largely unknown. In this study, we demonstrated that miR-16 was specifically downregulated in both OSCC patients and cancer cell lines. In addition, functional roles of miR-16 in vitro suggested that the miR-16 mimic inhibited cell proliferation and induced apoptosis, whereas miR-16 inhibitor displayed the opposite effects. Luciferase reporter assay and correlation analysis showed that AKT3 and BCL2L2 were directly targeted by miR-16 and were inversely expressed with miR-16 in OSCC. Moreover, restoration of AKT3 and BCL2L2 expression could partially reverse the cell proliferation inhibition and apoptosis induction caused by miR-16. In xenograft nude mice, miR-16 mimics decreased the expression of AKT3 and BCL2L2 and reduced the tumors volumes and weights, whereas the miR-16 inhibitor exhibited adverse effects in the derived xenografts. In conclusion, the findings suggested that miR-16 functions as a tumor suppressor miRNA to inhibit cell proliferation and induce apoptosis in OSCC through decreasing the oncogenes AKT3 and BCL2L2 and that miR-16 could be a potential therapeutic target for OSCC.

Downregulation of miR-218-5p promotes invasion of oral squamous cell carcinoma cells via activation of CD44-ROCK signaling

The invasion front of oral squamous cell carcinoma (OSCC) harbors the most aggressive cells of the tumor and is critical for cancer invasion and metastasis. MicroRNAs (miRNAs) play important roles in OSCC progression. In this study, we modelled the OSCC invasion front on a microfluidic chip, and investigated differences in miRNA profiles between cells in the invasion front and those in the tumor mass by small RNA sequencing. We found that miR-218-5p was downregulated in invasion front cells and negatively regulates OSCC invasiveness by targeting the CD44-ROCK pathway. Thus, miR-218-5p may serve as a useful therapeutic target for OSCC. Moreover, invasion front cell isolation based-on microfluidic technology provided a useful strategy for cancer invasion study.

Invasion-Related Factors as Potential Diagnostic and Therapeutic Targets in Oral Squamous Cell Carcinoma-A Review

It is well recognized that the presence of cervical lymph node metastasis is the most important prognostic factor in oral squamous cell carcinoma (OSCC). In solid epithelial cancer, the first step during the process of metastasis is the invasion of cancer cells into the underlying stroma, breaching the basement membrane (BM)—the natural barrier between epithelium and the underlying extracellular matrix (ECM). The ability to invade and metastasize is a key hallmark of cancer progression, and the most complicated and least understood. These topics continue to be very active fields of cancer research. A number of processes, factors, and signaling pathways are involved in regulating invasion and metastasis. However, appropriate clinical trials for anti-cancer drugs targeting the invasion of OSCC are incomplete. In this review, we summarize the recent progress on invasion-related factors and emerging molecular determinants which can be used as potential for diagnostic and therapeutic targets in OSCC.