MiR-34a inhibits the proliferation, migration, and invasion of oral squamous cell carcinoma by directly targeting SATB2

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.

Thymoquinone Potentially Modulates the Expression of Key Onco- and Tumor Suppressor miRNAs in Prostate and Colon Cancer Cell Lines: Insights from PC3 and HCT-15 Cells

Prostate cancer (PC) and colon cancer significantly contribute to global cancer-related morbidity and mortality. Thymoquinone (TQ), a naturally occurring phytochemical found in black cumin, has shown potential as an anticancer compound. This study aimed to investigate the effects of TQ on the expression profile of key tumor suppressor and onco-suppressor miRNAs in PC3 prostate cancer cells and HCT-15 colon cancer cells. Cell viability assays revealed that TQ inhibited the growth of both cell lines in a dose-dependent manner, with IC50 values of approximately 82.59 μM for HCT-15 and 55.83 μM for PC3 cells. Following TQ treatment at the IC50 concentrations, miRNA expression analysis demonstrated that TQ significantly downregulated miR-21-5p expression in HCT-15 cells and upregulated miR-34a-5p, miR-221-5p, miR-17-5p, and miR-21-5p expression in PC3 cells. However, no significant changes were observed in the expression levels of miR-34a-5p and miR-200a-5p in HCT-15 cells. The current findings suggest that TQ might exert its antiproliferative effects by modulating specific tumor suppressor and onco-suppressor miRNAs in prostate and colon cancer cells. Further investigations are warranted to elucidate the precise underlying mechanisms and to explore the therapeutic potential of TQ in cancer treatment. To the best of our knowledge, this is the first report regarding the effect of TQ on the miRNA expression profile in colon and prostate cancer cell lines.

MicroRNA-1289 Functions as a Novel Tumor Suppressor in Oral Squamous Cell Carcinoma

Recently, numerous tumor-suppressive microRNAs (TS-miRs) have been identified in human malignancies. Here, we attempted to identify novel TS-miRs in oral squamous cell carcinoma (OSCC). First, we transfected human OSCC cells individually with 968 synthetic miRs mimicking human mature miRs individually, and the growth of these cells was evaluated using the WST-8 assay. Five miR mimics significantly reduced the cell growth rate by less than 30%, and the miR-1289 mimic had the most potent growth inhibitory effect among these miRs. Subsequently, we assessed the in vivo growth-inhibitory effects of miR-1289 using a mouse model. The administration of the miR-1289 mimic-atelocollagen complex significantly reduced the size of subcutaneously xenografted human OSCC tumors. Next, we investigated the expression of miR-1289 in OSCC tissues using reverse transcription-quantitative PCR. The expression level of miR-1289 was significantly lower in OSCC tissues than in the adjacent normal oral mucosa. Furthermore, 15 genes were identified as target genes of miR-1289 via microarray and Ingenuity Pathway Analysis (IPA) microRNA target filtering. Among these genes, the knockdown of magnesium transporter 1 (MAGT1) resulted in the most remarkable cell growth inhibition in human OSCC cells. These results suggested that miR-1289 functions as a novel TS-miR in OSCC and may be a useful therapeutic tool for patients with OSCC.

Review of Disease-Specific microRNAs by Strategically Bridging Genetics and Epigenetics in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most prevalent human malignancies and a global health concern with a poor prognosis despite some therapeutic advances, highlighting the need for a better understanding of its molecular etiology. The genomic landscape of OSCC is well-established and recent research has focused on miRNAs, which regulate gene expression and may be useful non-invasive biomarkers or therapeutic targets. A plethora of findings regarding miRNA expression have been generated, posing challenges for the interpretation and identification of disease-specific molecules. Hence, we opted to identify the most important regulatory miRNAs by bridging genetics and epigenetics, focusing on the key genes implicated in OSCC development. Based on published reports, we have developed custom panels of fifteen major oncogenes and five major tumor suppressor genes. Following a miRNA/target gene interaction analysis and a comprehensive study of the literature, we selected the miRNA molecules which target the majority of these panels that have been reported to be downregulated or upregulated in OSCC, respectively. As a result, miR-34a-5p, miR-155-5p, miR-124-3p, miR-1-3p, and miR-16-5p appeared to be the most OSCC-specific. Their expression patterns, verified targets, and the signaling pathways affected by their dysregulation in OSCC are thoroughly discussed.

Extracellular Vesicle-Based Drug Delivery Systems for Head and Neck Squamous Cell Carcinoma: A Systematic Review

It is estimated that there are over 890,000 new cases of head and neck squamous cell carcinoma (HNSCC) worldwide each year, accounting for approximately 5% of all cancer cases. Current treatment options for HNSCC often cause significant side effects and functional impairments, thus there is a challenge to discover more acceptable treatment technologies. Extracellular vesicles (EVs) can be utilized for HNSCC treatment in several ways, for example, for drug delivery, immune modulation, as biomarkers for diagnostics, gene therapy, or tumor microenvironment modulation. This systematic review summarizes new knowledge regarding these options. Articles published up to 11 December 2022, were identified by searching the electronic databases PubMed/MEDLINE, Scopus, Web of Science, and Cochrane. Only full-text original research papers written in English were considered eligible for analysis. The quality of studies was assessed using the Office of Health Assessment and Translation (OHAT) Risk of Bias Rating Tool for Human and Animal Studies, modified for the needs of this review. Of 436 identified records, 18 were eligible and included. It is important to note that the use of EVs as a treatment for HNSCC is still in the early stages of research, so we summarized information on challenges such as EV isolation, purification, and standardization of EV-based therapies in HNSCC.

miRNAs as potential game-changers in head and neck cancer: Future clinical and medicinal uses

Head and neck cancers (HNCs) are a group of heterogeneous tumors formed most frequently from epithelial cells of the larynx, lips, oropharynx, nasopharynx, and mouth. Numerous epigenetic components, including miRNAs, have been demonstrated to have an impact on HNCs characteristics like progression, angiogenesis, initiation, and resistance to therapeutic interventions. The miRNAs may control the production of numerous genes linked to HNCs pathogenesis. The roles that miRNAs play in angiogenesis, invasion, metastasis, cell cycle, proliferation, and apoptosis are responsible for this impact. The miRNAs also have an impact on crucial HNCs-related mechanistic networks like the WNT/β-catenin signaling, PTEN/Akt/mTOR pathway, TGFβ, and KRAS mutations. miRNAs may affect how the HNCs respond to treatments like radiation and chemotherapy in addition to pathophysiology. This review aims to demonstrate the relationship between miRNAs and HNCs with a particular emphasis on how miRNAs impact HNCs signaling networks.

HPV 16 E6 promotes growth and metastasis of esophageal squamous cell carcinoma cells in vitro

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal malignancies worldwide. Increasing evidence suggests that human papillomavirus (HPV) infection may be associated with the etiology of ESCC. However, the precise role of HPV in ESCC remains unclear.

METHODS AND RESULTS

Proliferation and apoptosis of ESCC cells upon infection with HPV16 E6 were detected using CCK-8 assays and Western blot analyses. The migration rate was measured with a wound healing assay, and a Transwell Matrigel invasion assay was used to detect the invasive ability. RT-qPCR was performed to detect the expression of E6AP, p53, and miR-34a. The proliferation rates were significantly higher in HPV16E6-transfected cell groups compared with the negative control groups. Bax protein expression was downregulated in HPV16E6-treated groups compared to the controls. The wound healing and Transwell Matrigel invasion assays indicated that HPV16 E6 infection could increase ESCC cell migration and invasion. Furthermore, E6AP, p53 and miR-34a expression were decreased in HPV16 E6-transfected cell lines.

CONCLUSION

Our results not only provide evidence that HPV16 E6 promotes cell proliferation, migration, and invasion in ESCC, but also suggests a correlation between HPV infection and E6AP, p53 and miR-34a expression. Consequently, HPV16 E6 may play an important role in ESCC development.

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.

In vitro experimental study on the formation of microRNA-34a loaded exosomes and their inhibitory effect in oral squamous cell carcinoma

Studies have shown the inhibitory effect of microRNA-34a on proliferation, migration, and invasion of oral squamous cell carcinoma. However, the lack of a safe and effective delivery system limits the clinical application of microRNA-34a in oral cancer treatment. An exosome is a small extracellular vesicle that mediates intercellular communication by delivering proteins, nucleic acids, and other contents, and functions as a natural drug delivery carrier. Here, we aimed to explore whether exosomes could be used to load microRNA-34a via co-incubation and further used to treat OSCC. Ultracentrifugation was used to obtain exosomes derived from HEK293T cells and the extracted exosomes were analyzed via transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting. Subsequently, we loaded cholesterol-modified microRNA-34a into HEK293T cell exosomes by co-incubation. Then, PKH67 and Cy3 co-labeled exo-microRNA-34a were co-incubated with HN6 cells and exosome entry into the HN6 cells was observed using a confocal laser scanning microscope. The cell proliferation, migration, and invasion were assessed by CCK-8 and Transwell assay analysis. SATB2 expression in HN6 cells was analyzed via western blotting. In this study, cholesterol-modified microRNA-34a was loaded into exosomes of HEK293T cells by co-incubation. The microRNA-34a-loaded exosomes were secreted from HEK293T cells and were absorbed by HN6 oral squamous carcinoma cells. Further, microRNA-34a-loaded exosomes led to a significant inhibition of HN6 cell proliferation, migration, and invasion by down regulating SATB2 expression. These results report a new delivery method for microRNA-34a, providing a new approach for the treatment of oral cancer.

Increased ACTL6A occupancy within mSWI/SNF chromatin remodelers drives human squamous cell carcinoma

Mammalian SWI/SNF (BAF) chromatin remodelers play dosage-sensitive roles in many human malignancies and neurologic disorders. The gene encoding the BAF subunit actin-like 6a (ACTL6A) is amplified early in the development of many squamous cell carcinomas (SCCs), but its oncogenic role remains unclear. Here we demonstrate that ACTL6A overexpression leads to its stoichiometric assembly into BAF complexes and drives their interaction and engagement with specific regulatory regions in the genome. In normal epithelial cells, ACTL6A was substoichiometric to other BAF subunits. However, increased ACTL6A levels by ectopic expression or in SCC cells led to near saturation of ACTL6A within BAF complexes. Increased ACTL6A occupancy enhanced polycomb opposition genome-wide to activate SCC genes and facilitated the co-dependent loading of BAF and TEAD-YAP complexes on chromatin. Both mechanisms appeared to be critical and function as a molecular AND gate for SCC initiation and maintenance, thereby explaining the specificity of the role of ACTL6A amplification in SCCs.

LINC01123 is associated with prognosis of oral squamous cell carcinoma and involved in tumor progression by sponging miR-34a-5p

OBJECTIVE

Oral squamous cell carcinoma (OSCC) is a malignant tumor. This study aimed to investigate the role of a long noncoding RNA (lncRNA), LINC01123, in OSCC prognosis and progression and to explore the underlying mechanisms.

STUDY DESIGN

OSCC tissues were collected from 102 patients, and 4 OSCC cell lines were analyzed. The expression levels of LINC01123 and miR-34a-5p were estimated using quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8) and Transwell assays were used to assess the proliferation, migration, and invasion of OSCC cells. Kaplan-Meier survival analysis was used to analyze the prognostic value of LINC01123 in OSCC.

RESULTS

The analysis results showed that LINC01123 was overexpressed in OSCC tumor tissues; also, the prognosis of patients with OSCC with high LINC01123 expression levels was poor. The knockdown of LINC01123 inhibited the proliferation, migration, and invasion of OCSS cells. MiR-34a-5p was a target of LINC01123, and its inhibitor could reverse the effect of silenced LINC01123 on the progression of OSCC.

CONCLUSIONS

Highly expressed LINC01123 was associated with poor prognosis of OSCC and regulated OSCC cell proliferation, invasion, and migration by sponging miR-34a-5p. Therefore, the LINC01123/miR-34a-5p axis may provide new ideas for the prognosis and treatment of OSCC.

CircMYLK promotes the growth, migration, invasion, and survival of bladder cancer cells by upregulating CCND3 level via competitively binding to miR-34a

Bladder cancer is one of the most common types of urothelial carcinoma with a rising incidence rate worldwide. Circular RNAs (circRNAs) are involved in the development of numerous cancers, including bladder cancer. We aimed to uncover the role and associated mechanism of circMYLK in bladder cancer. The expression levels of circMYLK, miRNA-34a (miR-34a) and Cyclin D3 (CCND3) mRNA were investigated using real-time quantitative polymerase chain reaction. The protein level of CCND3 was investigated using western blot. In functional assays, flow cytometry assays were utilized for cell cycle analysis and cell apoptosis analysis. Transwell assays were used for cell migration and invasion analysis. Caspase-3 activity was examined to monitor cell apoptosis. The putative relationship between miR-34a and circMYLK or CCND3 was validated by dual-luciferase reporter assay and RNA immunoprecipitation assay. CircMYLK was highly expressed in bladder cancer tissues and cells. CircMYLK downregulation inhibited bladder cancer cell migration and invasion, and promoted cancer cell apoptosis and cell cycle arrest. MiR-34a, a target of circMYLK, was downregulated in bladder cancer tissues and cells. MiR-34a inhibition reversed the effects of circMYLK downregulation and then recovered bladder cell malignant behaviors. Further analysis showed that CCND3 was a downstream target of miR-34a, and CCND3 was upregulated in bladder cancer tissues and cells. MiR-34a overexpression blocked bladder cancer cell migration and invasion, and induced cell apoptosis and cycle arrest, while these effects were abolished by CCND3 overexpression. CircMYLK contributed to the malignant development of bladder cancer cells partly through the miR-34a/CCND3 regulatory network, showing the significance of circMYLK in bladder cancer pathogenesis.

SATB2 overexpression promotes oral squamous cell carcinoma progression by up-regulating NOX4

While atypical expression of special AT-rich sequence-binding protein 2 (SATB2) has been approved associated with tumor progression, metastasis and unfavourable prognosis in various carcinomas. However, in oral squamous cell carcinoma (OSCC), both the expressive state and associated functions of SATB2's are still undefined. Here we show that, in clinical samples from a retrospective cohort of 58 OSCC patients, high expression of SATB2 is associated with poor prognosis of OSCC patients. In this study, we investigated SATB2 is highly expressed in OSCC tissues and cell lines, which can promote OSCC cells' proliferation, migration, invasion and tumor growth. According to sequencing results based on previous literature, we identified NOX4 is a bona fide downstream target of SATB2, when it was knockdown, OSCC's proliferation can be partially suppressed. Furthermore, NOX4 knockdown inhibits tumorigenicity, which can be rescued partially by ectopic expression of SATB2 in HNSCC cell line, and vice versa. Collectively, our findings not only indicate overexpression of SATB2 triggers the proliferative, migratory and invasive mechanisms which are important in the malignant phenotype of OSCC, but also identify NOX4 as the downstream gene for SATB2. These findings indicate that SATB2 may play a key role in OSCC tumorigenicity and may be a future target for the development of new therapeutic regimens.

Silencing of miR-483-5p alleviates postmenopausal osteoporosis by targeting SATB2 and PI3K/AKT pathway

Postmenopausal osteoporosis (PMOP) poses a significant threat to women's health worldwide. However, detailed molecular mechanism and therapeutic strategy for PMOP remain insufficient. Accumulating evidence suggests that miR-48-5p is implicated in the pathogenesis of osteoporosis. The present study aimed to determine the role and mechanism of miR-483-5p in PMOP. Results from PMOP patients demonstrated that miR-483-5p was up-regulated and SATB2 was down-regulated. Luciferase reporter assay identified SATB2 as a direct target gene of miR-483-5p. Experiments in MC3T3-E1 cells indicated that miR-483-5p mimic markedly inhibited cell viability as well as the expressions of OPG, RUNX2 and BMP2. And miR-483-5p inhibitor, SATB2-overexpressed lentiviruses (Lv-SATB2) or LY294002 (PI3K/AKT inhibitor) significantly reversed the above results. Similarly, PI3K/AKT signaling was activated by miR-483-5p mimic, and was inhibited in miR-483-5p inhibitor, Lv-SATB2 or LY294002 treated cells. In vivo experiments showed that miR-483-5p inhibitor significantly increased the bone mineral density and biomechanical parameters of femurs in ovariectomized (OVX) rats by targeting SATB2. In addition, the osteogenic differentiation and PI3K/AKT signaling were also regulated by miR-483-5p-SATB2 axis. Taken together, our findings indicated that miR-483-5p contributed to the pathogenesis of PMOP by inhibiting SATB2 and activating PI3K/AKT pathway. MiR-483-5p/SATB2 could be selected as a potential therapeutic target for PMOP.

Regulators at Every Step-How microRNAs Drive Tumor Cell Invasiveness and Metastasis

Simple Summary

Tumor cell invasiveness and metastasis are key processes in cancer progression and are composed of many steps. All of them are regulated by multiple microRNAs that either promote or suppress tumor progression. Multiple studies demonstrated that microRNAs target the mRNAs of multiple genes involved in the regulation of cell motility, local invasion, and metastatic niche formation. Thus, microRNAs are promising biomarkers and therapeutic targets in oncology.

Abstract

Tumor cell invasiveness and metastasis are the main causes of mortality in cancer. Tumor progression is composed of many steps, including primary tumor growth, local invasion, intravasation, survival in the circulation, pre-metastatic niche formation, and metastasis. All these steps are strictly controlled by microRNAs (miRNAs), small non-coding RNA that regulate gene expression at the post-transcriptional level. miRNAs can act as oncomiRs that promote tumor cell invasion and metastasis or as tumor suppressor miRNAs that inhibit tumor progression. These miRNAs regulate the actin cytoskeleton, the expression of extracellular matrix (ECM) receptors including integrins and ECM-remodeling enzymes comprising matrix metalloproteinases (MMPs), and regulate epithelial–mesenchymal transition (EMT), hence modulating cell migration and invasiveness. Moreover, miRNAs regulate angiogenesis, the formation of a pre-metastatic niche, and metastasis. Thus, miRNAs are biomarkers of metastases as well as promising targets of therapy. In this review, we comprehensively describe the role of various miRNAs in tumor cell migration, invasion, and metastasis.

Regulators at Every Step—How microRNAs Drive Tumor Cell Invasiveness and Metastasis

Tumor cell invasiveness and metastasis are the main causes of mortality in cancer. Tumor progression is composed of many steps, including primary tumor growth, local invasion, intravasation, survival in the circulation, pre-metastatic niche formation, and metastasis. All these steps are strictly controlled by microRNAs (miRNAs), small non-coding RNA that regulate gene expression at the post-transcriptional level. miRNAs can act as oncomiRs that promote tumor cell invasion and metastasis or as tumor suppressor miRNAs that inhibit tumor progression. These miRNAs regulate the actin cytoskeleton, the expression of extracellular matrix (ECM) receptors including integrins and ECM-remodeling enzymes comprising matrix metalloproteinases (MMPs), and regulate epithelial–mesenchymal transition (EMT), hence modulating cell migration and invasiveness. Moreover, miRNAs regulate angiogenesis, the formation of a pre-metastatic niche, and metastasis. Thus, miRNAs are biomarkers of metastases as well as promising targets of therapy. In this review, we comprehensively describe the role of various miRNAs in tumor cell migration, invasion, and metastasis.

Inhibition of Lnc-OC1 Induced Cell Apoptosis and Decreased Cell Viability by Releasing miR-34a and Inhibiting PD-L1 in Endometrial Carcinoma

Now, there is a growing awareness of the role to long non-coding RNAs (lncRNAs) in tumorigenesis and progression of a variety of malignancies including endometrial carcinoma (EC). Here, we explored the potential molecular mechanism of Lnc-OC1, a novel lncRNA, in the development of EC. Our results suggested that Lnc-OC1 was significantly upregulated in EC tissues comparing with normal tissues. Besides, Lnc-OC1 was higher expressed in the more advanced stage of EC. Therefore, Lnc-OC1 might be a crucial regulator in the progress of EC. Moreover, knockdown of Lnc-OC1 leaded to an inhibition of cell viability and a raise of cell apoptosis. In addition, Lnc-OC1 could sponge miR-34a and thus decrease its expression. miR-34a was proved to be a tumor suppressor in different malignance, hence downregulating Lnc-OC1 helped to alleviate EC by releasing miR-34a. Furthermore, rescue experiments significantly indicated that knockdown of Lnc-OC1 inhibited cell growth through repressing PD-L1 expression at least partially. Concisely, our results proved that Lnc-OC1/miR-34a/PD-L1 axis might serve as a therapeutic target of EC.