Low expression of miR-let-7a promotes cell growth and invasion through the regulation of c-Myc in oral squamous cell carcinoma

Engineered extracellular vesicles carrying let-7a-5p for alleviating inflammation in acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening respiratory condition characterized by severe inflammation and lung tissue damage, frequently causing rapid respiratory failure and long-term complications. The microRNA let-7a-5p is involved in the progression of lung injury, inflammation, and fibrosis by regulating immune cell activation and cytokine production. This study aims to use an innovative cellular electroporation platform to generate extracellular vesicles (EVs) carring let-7a-5p (EV-let-7a-5p) derived from transfected Wharton's jelly-mesenchymal stem cells (WJ-MSCs) as a potential gene therapy for ALI.

METHODS

A cellular nanoporation (CNP) method was used to induce the production and release of EV-let-7a-5p from WJ-MSCs transfected with the relevant plasmid DNA. EV-let-7a-5p in the conditioned medium were isolated using a tangential flow filtration (TFF) system. EV characterization followed the minimal consensus guidelines outlined by the International Society for Extracellular Vesicles. We conducted a thorough set of therapeutic assessments, including the antifibrotic effects using a transforming growth factor beta (TGF-β)-induced cell model, the modulation effects on macrophage polarization, and the influence of EV-let-7a-5p in a rat model of hyperoxia-induced ALI.

RESULTS

The CNP platform significantly increased EV secretion from transfected WJ-MSCs, and the encapsulated let-7a-5p in engineered EVs was markedly higher than that in untreated WJ-MSCs. These EV-let-7a-5p did not influence cell proliferation and effectively mitigated the TGF-β-induced fibrotic phenotype by downregulating SMAD2/3 phosphorylation in LL29 cells. Furthermore, EV-let-7a-5p regulated M2-like macrophage activation in an inflammatory microenvironment and significantly induced interleukin (IL)-10 secretion, demonstrating their modulatory effect on inflammation. Administering EVs from untreated WJ-MSCs slightly improved lung function and increased let-7a-5p expression in plasma in the hyperoxia-induced ALI rat model. In comparison, EV-let-7a-5p significantly reduced macrophage infiltration and collagen deposition while increasing IL-10 expression, causing a substantial improvement in lung function.

CONCLUSION

This study reveals that the use of the CNP platform to stimulate and transfect WJ-MSCs could generate an abundance of let-7a-5p-enriched EVs, which underscores the therapeutic potential in countering inflammatory responses, fibrotic activation, and hyperoxia-induced lung injury. These results provide potential avenues for developing innovative therapeutic approaches for more effective interventions in ALI.

MicroRNA Let-7a association with glycolysis-induced autophagy in locally advanced gastric cancer: Their role in prognosis and FLOT chemotherapy resistance

Locally advanced gastric cancer (LAGC) still poses a clinical challenge despite multimodality treatment due to multidrug resistance (MDR). Recently, research suggested that autophagy and metabolic regulation may be potential anticancer targets due to their crucial roles in MDR. Let-7a participates in glycolytic and autophagic regulations which are both essential for tumor progression and resistance to therapy. This study used IHC stains; GLUT4 and LC3B to evaluate glycolysis and autophagy respectively. Moreover, mRNA Let-7a was detected by quantitative reverse transcription PCR (q-PCR) in 53 cases of LAGC. Elevated glycolysis and autophagy in LAGC tissue specimens as indicated by high GLUT4 and LC3B expression were significantly associated with adverse prognostic factors such as high pathological grade, positive nodal metastasis, and advanced T stage. Lower Let-7a levels were significantly associated with high tumor grade and advanced T stage. A significant positive correlation between GLUT4 and LC3B expression was detected. Significant inverse correlations between let7a level and IHC expression of both GLUT4 and LC3B were found. Elevated glycolysis and autophagy were significantly associated with poor overall survival (OS). Furthermore, low levels of let-7a were significantly associated with poor OS compared to high levels. Glycolysis and autophagy in LAGC were significantly associated with poor FLOT chemotherapy response. Let7a mRNA relative expression was significantly decreased in cases showing post therapy partial response and sustained disease. Multivariate analysis showed that histologic tumor type, high GLUT4 and high LC3B expression were independent factors associated with poor OS. Poor survival and post FLOT chemotherapy resistance in LAGC cases were significantly related to elevated glycolysis, elevated autophagy, and reduced Let-7a expression. Accordingly, combined therapeutic targeting of these pathways could enhance chemosensitivity in LAGC.

Panoramic view of key cross-talks underpinning the oral squamous cell carcinoma stemness - unearthing the future opportunities

The clinical management of oral cancer is often frequented with challenges that arise from relapse, recurrence, invasion and resistance towards the cornerstone chemo and radiation therapies. The recent conceptual advancement in oncology has substantiated the role of cancer stem cells (CSC) as a predominant player of these intricacies. CSC are a sub-group of tumor population with inherent adroitness to self-renew with high plasticity. During tumor evolution, the structural and functional reprogramming persuades the cancer cells to acquire stem-cell like properties, thus presenting them with higher survival abilities and treatment resistance. An appraisal on key features that govern the stemness is of prime importance to confront the current challenges encountered in oral cancer. The nurturing niche of CSC for maintaining its stemness characteristics is thought to be modulated by complex multi-layered components encompassing neoplastic cells, extracellular matrix, acellular components, circulatory vessels, various cascading signaling molecules and stromal cells. This review focuses on recapitulating both intrinsic and extrinsic mechanisms that impart the stemness. There are contemplating evidences that demonstrate the role of transcription factors (TF) in sustaining the neoplastic stem cell's pluripotency and plasticity alongside the miRNA in regulation of crucial genes involved in the transformation of normal oral mucosa to malignancy. This review illustrates the interplay between miRNA and various known TF of oral cancer such as c-Myc, SOX, STAT, NANOG and OCT in orchestrating the stemness and resistance features. Further, the cross-talks involved in tumor micro-environment inclusive of cytokines, macrophages, extra cellular matrix, angiogenesis leading pathways and influential factors of hypoxia on tumorigenesis and CSC survival have been elucidated. Finally, external factorial influence of oral microbiome gained due to the dysbiosis is also emphasized. There are growing confirmations of the possible roles of microbiomes in the progression of oral cancer. Given this, an attempt has been made to explore the potential links including EMT and signaling pathways towards resistance and stemness. This review provides a spectrum of understanding on stemness and progression of oral cancers at various regulatory levels along with their current therapeutic knowledge. These mechanisms could be exploited for future research to expand potential treatment strategies.

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

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

Serum and Saliva Level of miR-31-5p and miR-let 7a in EBV Associated Oropharyngeal Cancer

Epstein-Barr virus (EBV) has a well-documented association with head and neck neoplasms, including nasopharyngeal carcinoma (NPC). In the last few years, research aimed at elucidating the role of the miRs in the pathogenesis of head and neck cancer (HNC) has gained importance. The study of miRs expression has set new directions in the search for biomarkers with diagnostic and prognostic value, and even in the search for new therapeutic targets for various tumors, including HNC. The aim of current study was to approximate the importance of miR-31-5p and miR-let 7a in the pathogenesis of EBV associated oropharyngeal cancer. For this purpose, experiments were carried out to determine the level of mentioned miRs in serum among patients diagnosed with oropharyngeal cancer linked to EBV infection, depending on histological differentiation-grading (G1-G3) and TNM classification. All clinical specimens stratified by HPV status were HPV negative. The level of antibodies EBNA and EBVCA was also assessed. The obtained results showed a significantly increased serum level of miR-31-5p but decreased level of miR-let 7a in EBV positive oropharyngeal cancer patients. We demonstrated association between the level of tested miRs and clinical stage. Our findings showed that miR-31-5p and miR-let-7a may be involved in development and progression of EBV associated oropharyngeal cancer. Therefore, it seems important to further study these molecules, as well as to determine whether they could be important biomarkers in the diagnosis of oropharyngeal cancer associated with EBV infection.

Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power

The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.

Relevance of micro-RNAs and their targets as a diagnostic and prognostic marker in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) ranks sixth among all cancers in the world, affecting various sites of the oral cavity with associated several risk factors. High mortality has been associated with the presence of metastasis during the time of diagnosis and an increase in therapeutic relapses. Micro-RNAs (miRNAs) are a group of small non-coding RNAs with salient roles in the initiation and progression of cancer. The tumorigenesis of OSCC is associated with the dysregulation of several miRNAs. MicroRNAs are an area of recent interest, and numerous studies have been reported and are being undertaken to identify their role in diagnostic and prognostic value for oral cancers. Most of the miRNA processing machinery is considered to be either up-/down-regulated in OSCC, but the underlying mechanism of miRNA dysregulation and their activity as either a tumour suppressor or an oncogene in oral carcinogenesis is not yet clear. The article presents a concise review of the available current literature regarding the various miRNAs' signatures in OSCC and their role as diagnostic/prognostic biomarkers.

Reciprocal interplays between MicroRNAs and pluripotency transcription factors in dictating stemness features in human cancers

The interplay between microRNAs (miRNAs) and pluripotency transcription factors (TFs) orchestrates the acquisition of cancer stem cell (CSC) features during the course of malignant transformation, rendering them essential cancer cell dependencies and therapeutic vulnerabilities. In this review, we discuss emerging themes in tumor heterogeneity, including the clonal evolution and the CSC models and their implications in resistance to cancer therapies, and then provide thorough coverage on the roles played by key TFs in maintaining normal and malignant stem cell pluripotency and plasticity. In addition, we discuss the reciprocal interactions between miRNAs and MYC, OCT4, NANOG, SOX2, and KLF4 pluripotency TFs and their contributions to tumorigenesis. We provide our view on the potential to interfere with key miRNA-TF networks through the use of RNA-based therapeutics as single agents or in combination with other therapeutic strategies, to abrogate the CSC state and render tumor cells more responsive to standard and targeted therapies.

MicroRNA-124-3p-enriched small extracellular vesicles as a therapeutic approach for Parkinson's disease

Parkinson's disease is a neurodegenerative disease characterized by the loss of dopaminergic neurons in the substantia nigra with no effective cure available. MicroRNA-124 has been regarded as a promising therapeutic entity for Parkinson's disease due to its pro-neurogenic and neuroprotective roles. However, its efficient delivery to the brain remains challenging. Here, we used umbilical cord blood mononuclear cell-derived extracellular vesicles as a biological vehicle to deliver microRNA (miR)-124-3p and evaluate its therapeutic effects in a mouse model of Parkinson's disease. In vitro, miR-124-3p-loaded small extracellular vesicles induced neuronal differentiation in subventricular zone neural stem cell cultures and protected N27 dopaminergic cells against 6-hydroxydopamine-induced toxicity. In vivo, intracerebroventricularly administered small extracellular vesicles were detected in the subventricular zone lining the lateral ventricles and in the striatum and substantia nigra, the brain regions most affected by the disease. Most importantly, although miR-124-3p-loaded small extracellular vesicles did not increase the number of new neurons in the 6-hydroxydopamine-lesioned striatum, the formulation protected dopaminergic neurons in the substantia nigra and striatal fibers, which fully counteracted motor behavior symptoms. Our findings reveal a novel promising therapeutic application of small extracellular vesicles as delivery agents for miR-124-3p in the context of Parkinson's disease.

CircPVT1 facilitates the progression of oral squamous cell carcinoma by regulating miR-143-3p/SLC7A11 axis through MAPK signaling pathway

Oral squamous cell carcinoma (OSCC) is a common malignant tumor occurring in the oral cavity. Circular RNAs (circRNAs) play a crucial regulatory role in many cancers. This study aimed to investigate the function of circRNA plasmacytoma variant translocation 1 (PVT1) (circPVT1) in OSCC and its potential mechanism. The levels of circPVT1, solute carrier family 7 member 11 (SLC7A11), and microRNA-143-3p (miR-143-3p) were examined by quantitative real-time PCR (qRT-PCR) or western blot assay. Cell proliferation, apoptosis, migration, and invasion were evaluated by Cell Counting Kit-8 (CCK-8), colony formation assay, flow cytometry, and transwell assay. The levels of apoptosis and proliferation-related proteins were examined by western blot. The targeting relationship between miR-143-3p and circPVT1 or SLC7A11 was verified by dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays. The levels of mitogen-activated protein kinase (MAPK) pathway-related proteins were measured by western blot. Xenograft assay was used to assess tumor growth in vivo. CircPVT1 and SLC7A11 were upregulated, while miR-143-3p was downregulated in OSCC tissues and cells. Silencing of circPVT1 or SLC7A11 suppressed proliferation, migration, and invasion and promoted apoptosis in OSCC cells. CircPVT1 upregulated SLC7A11 expression via sponging miR-143-3p. SLC7A11 upregulation alleviated the effect of circPVT1 knockdown on OSCC cell progression. Besides, circPVT1 modulated MAPK signaling pathway by regulating miR-143-3p. Moreover, circPVT1 knockdown inhibited tumor growth in vivo. Knockdown of circPVT1 impeded OSCC progression via the miR-143-3p/SLC7A11 axis through MAPK signaling pathway.

Promising Biomarkers in Head and Neck Cancer: The Most Clinically Important miRNAs

Head and neck cancers (HNCs) comprise a heterogeneous group of tumors that extend from the oral cavity to the upper gastrointestinal tract. The principal etiologic factors for oral tumors include tobacco smoking and alcohol consumption, while human papillomavirus (HPV) infections have been accused of a high incidence of pharyngeal tumors. Accordingly, HPV detection has been extensively used to categorize carcinomas of the head and neck. The diverse nature of HNC highlights the necessity for novel, sensitive, and precise biomarkers for the prompt diagnosis of the disease, its successful monitoring, and the timely prognosis of patient clinical outcomes. In this context, the identification of certain microRNAs (miRNAs) and/or the detection of alterations in their expression patterns, in a variety of somatic fluids and tissues, could serve as valuable biomarkers for precision oncology. In the present review, we summarize some of the most frequently studied miRNAs (including miR-21, -375, -99, -34a, -200, -31, -125a/b, -196a/b, -9, -181a, -155, -146a, -23a, -16, -29, and let-7), their role as biomarkers, and their implication in HNC pathogenesis. Moreover, we designate the potential of given miRNAs and miRNA signatures as novel diagnostic and prognostic tools for successful patient stratification. Finally, we discuss the currently ongoing clinical trials that aim to identify the diagnostic, prognostic, or therapeutic utility of miRNAs in HNC.

Research progress and clinical application prospects of miRNAs in oral cancer

Oral cancer is one of the most common malignant tumors worldwide, and it is also one of the most important and difficult clinical problems to be solved. Due to the regional differences in diet culture, some areas have taken the 'hardest hit' of oral cancer cases. However, the existing clinical treatment methods (surgery as the main treatment method, radiotherapy and chemotherapy as the auxiliary ones) do not have satisfactory treatment effects; therefore, new diagnosis and treatment methods need to be developed and utilized. Micro RNAs (miRNAs), as a class of substances that play an important regulatory role in the development of tumors, have an important value in the diagnosis and treatment of various tumors. At the same time, many miRNAs have obvious expression differences in oral cancer tissues compared to normal tissues. Therefore, they may have diagnostic and therapeutic effects on oral cancer. In this review, we evaluate the miRNAs that play a regulatory role in the development of oral cancer and those that are expected to be applied in the diagnosis and treatment of oral cancer. At the same time, we summarize the important challenges that need to be addressed, aiming to provide evidence and suggestions for the application of miRNAs in the diagnosis and treatment of oral cancer.

Smartly responsive DNA-miRNA hybrids packaged in exosomes for synergistic enhancement of cancer cell apoptosis

Endogenous and exogenous tumor-related microRNAs (miRNAs) are considered promising tumor biomarkers and tumor therapeutic agents. In this work, we propose a miRNA self-responsive drug delivery system (miR-SR DDS), which enables the association between endogenous and exogenous miRNAs, so as to achieve a smart responsive and synergistic drug delivery. The miR-SR DDS consists of DNA-miRNA hybrids of let-7a and the complementary DNA of miR-155, which was packaged in exosomes. In response to the overexpressed miR-155 in breast cancer cells, the hybrids disintegrate and release let-7a and the complementary DNA of miR-155 to inhibit the expression of HMGA1 and relieve the inhibition of SOX1, respectively. Under the dual-targeted gene regulation, results show that the growth, migration and invasion of breast cancer cells can be synergistically inhibited through the Wnt/β-catenin signaling pathway. The concept and successful practice of the miR-SR DDS can be used as a reference for the development of miRNA drugs.

Identification and validation of transcription factor-driven enhancers of genes related to lipid metabolism in metastatic oral squamous cell carcinomas

Background

The role and mechanisms of lipid metabolism in oral squamous cell carcinomas (OSCC) metastasis have not been clarified. This study aims to identify lipid metabolism-related genes and transcription factors regulated by metastasis-associated enhancers (MAEs) in OSCC.

Methods

Gene Set Enrichment Analysis (GSEA) and Gene Set Variation Analysis (GSVA) were performed for lipid metabolism enrichment. TCGA data were used to analyze the differentially expressed lipid metabolism-related genes. MAEs were analyzed using GSE120634. Overlapping analysis was used to screen the MAE-regulated lipid metabolism-related genes, and the prognosis of these genes was analyzed. Transcription factor prediction was performed for the MAE-regulated lipid metabolism-related genes with prognostic value. Validation of the metastatic specificity of MAEs at ACAT1, OXSM and VAPA locus was performed using GSE88976 and GSE120634. ChIP-qPCR, qRT-PCR and Western blotting were used to verify the regulation of ACAT1, OXSM and VAPA expression by CBFB. Effects of CBFB knockdown on proliferation, invasion and lipid synthesis in metastatic OSCC cells were analyzed.

Results

Lipid metabolism was significantly enhanced in metastatic OSCC compared to non-metastatic OSCC. The expression of 276 lipid metabolism-related genes was significantly upregulated in metastatic OSCC, which were functionally related to lipid uptake, triacylglycerols, phospholipids and sterols metabolism. A total of 6782 MAEs and 176 MAE-regulated lipid metabolism-related genes were filtered. Three MAE-regulated lipid metabolism-related genes, ACAT1, OXSM and VAPA, were associated with a poor prognosis in OSCC patients. Enhancers at ACAT1, OXSM and VAPA locus were metastasis-specific enhancers. CBFB regulated ACAT1, OXSM and VAPA expression by binding to the enhancers of these genes. Knockdown of CBFB inhibited proliferation, invasion and lipid synthesis in metastatic OSCC cells.

Conclusion

The MAE-regulated lipid metabolism-related genes (ACAT1, OXSM and VAPA) and the key transcription factor (CBFB) were identified. CBFB knockdown inhibited proliferation, invasion and lipid synthesis of OSCC cells. These findings provide novel candidates for the development of therapeutic targets for OSCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02157-7.

Upregulated microRNA let-7a accelerates apoptosis and inhibits proliferation in uterine junctional zone smooth muscle cells in adenomyosis under conditions of a normal activated hippo-YAP1 axis

BACKGROUND

Let-7a is a small non-coding RNA that has been found to take part in cell proliferation and apoptosis. The hippo-YAP1 axis, known as a tumour suppressor pathway, also plays an important role in cell proliferation and apoptosis. YAP1, TAZ, and phospho-YAP1 play key roles in actions of the hippo-YAP1 axis. Adenomyosis (ADS) is a proliferative disease leading to a large uterus in patients with prolonged illness. Abnormal proliferation of smooth muscle cells (SMCs) in the uterine endometrial-myometrial junctional zone (JZ) is an important reason for developing ADS. This study aimed to explore the expression levels of let-7a and components of the hippo-YAP1 axis in SMCs in the uterine endometrial-myometrial JZ in ADS and to explore the roles of let-7a and the hippo-YAP1 axis of JZ SMC proliferation and apoptosis in ADS.

METHODS

We collected JZ tissues for the primary culture of SMCs from 25 women diagnosed with ADS and 27 women without ADS. We used quantitative real-time polymerase chain reaction and western blotting to measure the mRNA and protein expression levels of let-7a, YAP1, TAZ, and phospho-YAP1 in ADS JZ SMCs. A CCK-8 assay and flow cytometry analysis of apoptosis were utilized to test the proliferation and apoptosis of JZ SMCs. The let-7a overexpression lentiviral vector GV280 was used to increase the expression level of let-7a. We added verteporfin to block the phosphorylation of components of the hippo-YAP1 axis.

RESULTS

We found that the let-7a level was decreased, while the YAP1 and TAZ levels were increased in ADS JZ SMCs. Upregulated let-7a affected the expression levels of components of the hippo-YAP1 axis, accelerated apoptosis, and inhibited proliferation in JZ SMCs. Furthermore, accumulated YAP1 led to increasing proliferation of JZ SMCs after verteporfin treatment to block the phosphorylation of components of the hippo-YAP1 axis. If components of the hippo-YAP1 axis were unphosphorylated, upregulated let-7a could not inhibit the proliferation of ADS JZ SMCs. Upregulated let-7a could not activate the hippo-YAP1 axis in verteporfin treatment.

CONCLUSIONS

Our findings suggest that the let-7a and hippo-YAP1 axis may act as important regulators of JZ SMCs proliferation, and upregulated let-7a may be an effective method to treat ADS.