Upregulation of circFLNA contributes to laryngeal squamous cell carcinoma migration by circFLNA-miR-486-3p-FLNA axis

Exploring the evolving roles and clinical significance of circRNAs in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) represents the predominant malignancies in the head and neck region, and has limited therapeutic alternatives. Circular RNAs (circRNAs), a substantial category of non-coding RNA molecules, exert influential roles in human disease development and progression, employing various mechanisms such as microRNA sponging, interaction with RNA-binding proteins, and translational capabilities. Accumulating evidence highlights the differential expression of numerous circRNAs in HNSCC, and numerous dysregulated circRNAs underscore their crucial involvement in malignant advancement and resistance to treatment. This review aims to comprehensively outline the characteristics, biogenesis, and mechanisms of circRNAs, elucidating their functional significance in HNSCC. In addition, we delve into the clinical implications of circRNAs, considering their potential as biomarkers or targets for diagnosis, prognosis, and therapeutic applications in HNSCC. The discussion extends to exploring future challenges in the clinical translation of circRNAs, emphasizing the need for further research.

Curcumin suppresses the malignant phenotype of laryngeal squamous cell carcinoma through downregulating E2F1 to inhibit FLNA

Curcumin is a kind of polyphenol substance extracted from the rhizome of Curcuma longa. Because of its good biological activity and pharmacological effects, it has been used in anti-tumor research. The aim of this study was to investigate the anti-cancer mechanism of curcumin on laryngeal squamous cell carcinoma (LSCC). Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to check the expression level of transcription factor E2F1 (E2F1) and filamin A (FLNA) mRNA. E2F1 and FLNA protein and proliferation-associated protein were detected through western blot. Cell viability was showed by MTT assay, and flow cytometry was used to exhibit cell cycle distribution and cell apoptosis. Tube formation assay was used to detect the angiogenesis ability of cells. Transwell was used as a method to observe cell migration and invasion. The online website JASPAR predicted the binding site of E2F1 and FLNA promoter, and chromatin immunoprecipitation (ChIP) and dual-luciferase report experiment verified the combination. Curcumin treatment made LSCC cells viability reduce, cell cycle retardant, angiogenesis decrease, metastasis inhibition and apoptosis increase. And curcumin treatment could downregulate the expression of E2F1, and E2F1 overexpression would reverse the influence of curcumin treatment in LSCC cells. Moreover, E2F1 could bind to FLAN promoter and promote FLNA expression. The expression level of FLNA was higher in LSCC tissue and cells compared with normal tissue and cells. E2F1 knockdown inhibited malignant phenotype of LSCC cells, which would be reversed by FLNA addition. In addition, FLNA had high level in LSCC tissue and cells. Curcumin regulated FLNA expression via inhibiting E2F1. Finally, in vivo assay showed that curcumin inhibition restrained LSCC tumor formation. Curcumin downregulated FLNA expression through inhibiting E2F1, thereby suppressing the malignant phenotype and angiogenesis of LSCC cells, which was a new regulatory pathway in LSCC.

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.

The Clinical Significance of CD163+ Tumor-Associated Macrophages (TAMs) in Laryngeal Squamous Cell Carcinoma

Background and objective The tumor's microenvironment is currently considered an important indicator of the tumor's prognosis, treatment failure, and recurrence. CD163+ tumor-associated macrophages (TAMs) are a marker of poor prognosis in many types of human cancers. In the present study, the expression of CD163+ TAMs was analyzed in laryngeal squamous cell carcinomas (LSCCs) using immunohistochemistry, and this expression was correlated with the clinical and pathological characteristics of LSCC patients. Materials and methods One commercial human larynx microarray with 80 cases of LSCCs, was used for this study. For comparison with normal laryngeal mucosa, a second microarray carrying normal tissues from all human anatomical sites, including normal laryngeal tissues, was used. Immunohistochemical staining was performed, and the primary antibody was a mouse monoclonal against human CD136. The absence of the primary antibody was used as a negative control. The percentage of positive cells was categorized into five scores: 0 (0%); 1, (1%-10%); 2, (11%-50%); 3, (51%-80%); and 4, (>80%). A case was scored as positive for CD163 with a score >= 1. The χ2 test was used to assess the CD163 expression in LSCC cases (N=80). A statistically significant difference was defined as P 0.05. Results The human larynx microarray containing 80 cases of LSCCs was used for this study. The age of the cancer patients in this array was in the range of 39 to 72, with a median of 53. LSCC grades were distributed as follows: 25 patients were designated as grade I, 43 were designated as grade II, and 6 were designated as grade III. Two tumors' (2/80) cores were missing from the microarray. Six tumors on the microarray did not have a grade designation reported by the manufacturer of the array. The expression of CD163 in normal, benign, unmatched laryngeal tissue was absent. In cancer cases, on the other hand, a significant number of LSCCs had TAMs that were positive for CD163 (87% positive tumors, with an IHC score ranging from 1 to 4, χ2=30.634; p<0.001). The rest of the LSCC cases (10 in total) had negative CD163 expression (score of 0). Conclusion A significant majority of LSCCs were found to have CD163+ TAMs expression using tissue microarrays (TMAs). This expression is positively correlated with the tumor's grade, clinical manifestation, and TNM staging. Morphologic evidence shows that the majority of LSCCs express the highest range of immunohistochemistry (IHC) scores for CD163 protein in the membranes and cytoplasm of their TAMs. This study provides evidence of the clinical significance of CD163+TAMs in LSCCs and proposes further studies to pinpoint the exact role of these cells in LSCC patients.

CircSMAD2 accelerates endometrial cancer cell proliferation and metastasis by regulating the miR-1277-5p/MFGE8 axis

OBJECTIVE

Endometrial cancer (EC) is a common gynecological malignant tumor. CircRNAs play crucial roles in cancer progression and metastasis. However, the biological functions of circRNAs in EC remain largely unknown.

METHODS

CircSMAD2, miR-1277-5p, MFGE8 and relative maker protein expression in EC tissues or cell lines were analyzed by quantitative real-time polymerase chain reaction and Western blot. In vitro and in vivo functional assays, including EDU, CCK8, colony formation, transwell, tube formation and tumor xenograft assays, were conduct to explore the effects of circSMAD2 on EC. Mechanism assays were conducted to confirm the binding between miR-1277-5p and circSMAD2 or MFGE8 expression.

RESULTS

Upregulation of circSMAD2 was uncovered in both EC tissues and cell lines. Functionally, silencing of circSMAD2 apparently inhibited the proliferation, migration, invasion and angiogenesis of EC cell lines in vitro. Mechanistically, circSMAD2 sponged miR-1277-5p to upregulate MFGE8 expression. The decrease of miR-1277-5p and increase of MFGE8 were observed both in EC tissues and cell lines. Then MFGE8 knockdown or miR-1277-5p upregulation suppressed EC cell oncogenic biological behavior. Rescue experiments showed that miR-1277-5p mimics countervailed the anticancer effects of circSMAD2 silencing on EC. Besides that, MFGE8 overexpression also attenuated the inhibitory action of miR-1277-5p mimic in EC. Moreover, knockdown of circSMAD2 inhibited EC growth in vivo.

CONCLUSION

CircSMAD2 functions as an oncogene in promoting the progression of EC through miR-1277-5p/MFGE8 axis.

Circular RNA EPB41 expression predicts unfavorable prognoses in NSCLC by regulating miR-486-3p/eIF5A axis-mediated stemness

Dysregulation of circular RNAs (circRNAs) has recently been found to play an important role in the progression and development of cancers such as non-small cell lung cancer (NSCLC). Yet the functions of many circRNAs in NSCLC remain unclear. In this study, the circRNA expression profiles in NSCLC tumor tissues and adjacent non-tumorous tissues were detected by high-throughput sequencing. Bioinformatics analyses, the dual-luciferase reporter system, fluorescence in situ hybridization (FISH) and miRNA/mRNA high-throughput sequencing were used to identify circ-EPB41 and its downstream target. The subcutaneous tumor/caudal vein transfer mouse model was used for tumor growth and invasion analysis. The results show that the circ-EPB41 was upregulated in NSCLC tissues and cell lines. Increased circ-EPB41 expression in NSCLC was significantly correlated with malignant characteristics, and positive to post-surgical overall survival of NSCLC patients. Reduced circ-EPB41 expression in NSCLC decreased cell proliferation and invasion in both in vitro and in vivo experiments. The miRNA/mRNA high-throughput sequencing suggested that downregulation of circ-EPB41 promoted microRNA (miR)-486-3p and suppressed eukaryotic translation initiation factor 5A (eIF5A) expression. Luciferase reporter experiments confirmed that miR-486-3p/eIF5A were downstream targets of circ-EPB41. In addition, we also found that downregulation of circ-EPB41 suppressed self-renewal and decreased expression of stemness markers SOX2, OCT-4, Nanog and CD133 by sponging miR-486-3p to enhance eIF5A expression. Taken togeter, these data revealed the important role of circ-EPB41 in regulating NSCLC cell invasion and proliferation by modifying miR-486-3p/eIF5A axis-mediated stemness. We believe our study provides a novel perspective regarding the role of circRNAs in NSCLC progression.

Diagnostic and prognostic value of circRNAs expression in head and neck squamous cell carcinoma: A meta-analysis

Background

Circular RNAs (circRNAs) have been found to have potential biological applications against tumors in humans. This study aimed to evaluate the diagnostic, prognostic, and clinicopathological value of circRNAs in head and neck squamous cell carcinoma (HNSCC).

Methods

The PubMed, Web of Science, EMBASE, and the Cochrane Library were comprehensively searched for the relevant studies before October 20, 2021. Statistical analysis was performed based on STATA 15.0, Meta‐DiSc 1.4, and RevMan 5.3 software.

Results

A total of 55 reports regarding 56 kinds of circRNA were studied in this meta‐analysis, including 23, 38, and 26 articles on diagnosis, prognosis, and clinicopathological features, respectively. The pooled sensitivity, specificity, and area under the curve (AUC) of the summary receiver‐operating characteristic curve (SROC) were 0.78, 0.84, and 0.87, respectively. Besides, the upregulation of oncogenic circRNAs was significantly associated with poorer overall survival (OS) (HR=2.25, p < 0.05) and disease‐free interval (DFS) (HR=1.92, p < 0.05). In contrast, the elevated expression of tumor suppressor circRNAs was associated with a favorable prognosis (HR=0.50, p < 0.05). In addition, the high expression of oncogenic circRNAs was associated with the tumor size (OR=3.59, p < 0.05), degree of differentiation (OR=1.89, p < 0.05), TNM stage (OR=2.35, p < 0.05), lymph node metastasis (OR=1.85, p < 0.05), and distant metastasis (OR=3.42, p < 0.05). Moreover, the expression of tumor suppressor circRNAs was associated with improved clinicopathological features (lymph node metastasis: OR=0.25, p < 0.05).

Conclusions

CircRNAs could serve as potential predictive indicators and be useful for the diagnosis, prognosis, and identification of clinicopathological features in HNSCC.

miR-486-3p Controls the Apoptosis of Endometrial Carcinoma Cells

Our study aimed to discuss the mechanism of miR-486-3p in controlling the apoptosis of endometrial carcinoma (EC) cells. EC cells were divided into NC group, miR-486-3p mimic and miR-486-3p inhibitor group followed by analysis of miR-486-3p level by Real-time PCR, cell proliferation by spectrophotometric method, apoptosis by FCM, cell migration and invasion by Transwell analysis. EC cells showed reduced miR-486-3p level. The EC malignant biological behaviors could be prompted through retraining miR-486-3p level with increased EC cell invasive capacity. DDR1 was a target of miR-486-3p. The variation of tumor activity could be regulated through controlling DDR1 expression. In conclusion, the apoptotic and invasive characteristic of EC cells are restrained after overexpression of miR-486-3p in EC cells through targeting DDR1, indicating that miR-486-3p could be considered to be one kind of brand-new target for the treatment of EC.

Circ_0092012 knockdown restrains non-small cell lung cancer progression by inhibiting cell malignant phenotype and immune escape through microRNA-635/programmed death ligand 1 axis

Circular RNAs have been reported to play roles in non-small cell lung cancer (NSCLC) progression. Herein, this work aimed to investigate the potential value of circ_0092012 in NSCLC progression. Levels of genes and proteins were detected using quantitative reverse transcription-polymerase chain reaction and Western blot, respectively. The growth, malignant phenotypes and immune escape in NSCLC were investigated. The binding between microRNA (miR)-635 and circ_0092012 or programmed death ligand 1 (PDL1) was verified. Circ_0092012 was highly expressed in NSCLC. Circ_0092012 deficiency suppressed NSCLC cell proliferation, invasion and migration, moreover, as well as was able to inhibit the apoptosis of CD8 + T cells and induce higher interferon-γ and tumor necrosis factor-α levels when co-cultured with peripheral blood mononuclear cells. Mechanistically, circ_0092012 sponged miR-635, which targeted PDL1. Further rescue experiments suggested that the anticancer effects of circ_0092012 knockdown were reversed by miR-635 inhibition. Additionally, miR-635 re-expression suppressed NSCLC cell malignant phenotypes mentioned above and immune escape, which were attenuated by PDL1 overexpression. Moreover, circ_0092012 deletion retarded NSCLC growth in vivo. In all, circ_0092012 knockdown suppressed NSCLC cell oncogenic phenotypes and immune escape by miR-635/PDL1 axis.

Filamin-A expression in laryngeal squamous cell carcinoma and its clinical significance

BACKGROUND

Laryngeal squamous cell carcinomas (LSCCs) are tumours with a high incidence of treatment failure and recurrence. Recent strategies to improve the five-year survival rate and to decrease the rates of recurrence and metastases did not improve outcomes significantly. Research efforts in recent years have started focusing on discovering biomarkers of prognosis and management in LSCCs. Filamin-A reportedly has been associated with metastatic disease in a recent study. Analysis of this protein's expression in LSCCs is lacking in the literature.

MATERIALS AND METHODS

This study analysed the expression of filamin-A, using immunohistochemistry, in a tissue microarray of 80 cases of laryngeal squamous cell cancers. Clinical-pathological parameters were analysed according to filamin-A expression in the tissue microarray. Furthermore, a review of possible mechanisms of this protein in cancer, in general, was presented, along with a review of the protein's expression in other head and neck tumours.

RESULTS

A significant majority of laryngeal squamous cell cancers exhibited positive expression of filamin-A protein. All the filamin-A positive tumours expressed it in their cytoplasm. Significant correlation between filamin-A expression and grade, stage, lymph node status and metastases were found.

CONCLUSION

The above may suggest an important role for filamin-A in LSCCs. Overall, filamin-A expression in laryngeal cancer is in line with evidence seen in other head and neck cancers. Further studies are in order to pinpoint the exact role of this protein in LSCCs, and its possible utilization in the management of these difficult-to-treat tumours.

MicroRNA-486-3p promotes the proliferation and metastasis of cutaneous squamous cell carcinoma by suppressing flotillin-2

BACKGROUND

Dysregulation of miR-486-3p was related to the growth and development of a variety of cancers, but the specific function of miR-486-3p in cutaneous squamous cell carcinoma (cSCC) is not to be confirmed yet.

OBJECTIVE

Our present study aimed to validate the potential molecular mechanisms of miR-486-3p in cSCC and the potential of miR-486-3p as a novel target for future treatment.

METHODS

Human cSCC samples and normal skin tissues were applied to determine the expression level of miR-486-3p and FLOT2 by fluorescence in situ hybridization (FISH) and quantitative reverse transcription PCR (qRT-PCR), respectively. As well as BALB/C nude mouse tumor model, three cSCC cells lines including HSC-1, HSC-5 and A431 were utilized to demonstrate the potential function of miR-486-3p and FLOT2 in tumorigenesis.

RESULTS

Our experimental results showed that miR-486-3p was highly expressed both in tumor samples and cell lines of cSCC. Upregulation of miR-486-3p enhanced the proliferation and migration ability of cSCC cell lines and promoted tumorigenicity in vivo. Furthermore, we confirmed that FLOT2 was a direct targeted gene of miR-486-3p. In contrary to the expression level of miR-486-3p, FLOT2 was low expressed in cSCC patient specimens and cell lines. Knockdown of FLOT2 promoted tumorigenesis of cSCC; whereas FLOT2 reversed the tumor-promoting effect of miR-486-3p.

CONCLUSION

Our data exhibited that miR-486-3p exerted its effects on carcinogenesis as an oncogene in cSCC via suppression of FLOT2. This discovery will develop new therapeutic targets of cSCC.

Circular RNA FLNA acts as a sponge of miR-486-3p in promoting lung cancer progression via regulating XRCC1 and CYP1A1

Significantly high-expressed circFLNA has been found in various cancer cell lines, but not in lung cancer. Therefore, this study aimed to explore the role of circFLNA in the progression of lung cancer. The target gene of circFLNA was determined by bioinformatics and luciferase reporter assay. Viability, proliferation, migration, and invasion of the transfected cells were detected by CCK-8, colony formation, wound-healing, and transwell assays, respectively. A mouse subcutaneous xenotransplanted tumor model was established, and the expressions of circFLNA, miR-486-3p, XRCC1, CYP1A1, and related genes in the cancer cells and tissues were detected by RT-qPCR, Western blot, or immunohistochemistry. The current study found that miR-486-3p was low-expressed in lung cancer. MiR-486-3p, which has been found to target XRCC1 and CYP1A1, was regulated by circFLNA. CircFLNA was located in the cytoplasm and had a high expression in lung cancer cells. Cancer cell viability, proliferation, migration, and invasion were promoted by overexpressed circFLNA, XRCC1, and CYP1A1 but inhibited by miR-486-3p mimic and circFLNA knockdown. The weight of the xenotransplanted tumor was increased by circFLNA overexpression yet reduced by miR-486-3p mimic. Furthermore, miR-486-3p mimic reversed the effect of circFLNA overexpression on promoting lung cancer cells and tumors and regulating the expressions of miR-486-3p, XRCC1, CYP1A1, and metastasis/apoptosis/proliferation-related factors. However, overexpressed XRCC1 and CYP1A1 reversed the inhibitory effect of miR-486-3p mimic on cancer cells and tumors. In conclusion, circFLNA acted as a sponge of miR-486-3p to promote the proliferation, migration, and invasion of lung cancer cells in vitro and in vivo by regulating XRCC1 and CYP1A1.

Circular RNA circFLNA inhibits the development of bladder carcinoma through microRNA miR-216a-3p/BTG2 axis

Recent studies have shown that circular RNA circFLNA is abnormally expressed in a variety of malignant tumors, but its role and mechanism in bladder carcinoma (BCa) are still unclear. The present paper aims to contribute to research on the effects and mechanism of circFLNA on the malignant phenotype of BCa. In this study, the expressions of circFLNA, miR-216a-3p and BTG2 in BCa and BCa cells (EJ, T24, 5637, TCC-SUP) were detected by qRT-PCR. EdU staining, colony formation, Transwell assay, wound healing assays, and sphere formation assay were used to measure the cell proliferation, viability, invasion, migration, and cell stemness of BCa cells after circFLNA overexpression. In addition, the correlation existed between miR-216a-3p and circFLNA or BTG2 was confirmed by Dual-Luciferase Reporter assay and RNA pull-down. Western blot was utilized to determine the expression of BTG2, MMP2, epithelial-mesenchymal transition (EMT)-related proteins (vimentin, E-cadherin) and stem cell-specific proteins (CD34, OCT4, SOX2). Our study confirmed that downregulated circFLNA and BTG2 expression and upregulated miR-216a-3p were found in both BCa tissues and cell lines. Meanwhile, upregulated circFLNA inhibited proliferation, invasion and migration, EMT and stemness of BCa cells. MiR-216a-3p was a target gene of circFLNA and could target BTG2. Further analysis finally demonstrated that circFLNA sponged miR-216a-3p and indirectly promoted BTG2 expression, ultimately regulating proliferation, migration, invasion and EMT of BCa cells. In conclusion, circFLNA inhibits the malignant phenotype of BCa cells and their stemness through miR-216a-3p/BTG2, thus suppressing BCa progression.

Hsa-circ_0058106 induces EMT and metastasis in laryngeal cancer via sponging miR-153 and inducing Twist1 nuclear translocation

PURPOSE

A new circular RNA (hsa-circ_0058106) has been found to be upregulated in laryngeal cancer, but its function remains unknown. Here, we explored its role in the metastasis of laryngeal cancer.

METHODS

The level of hsa-circ_0058106 in laryngeal cancer was detected by qRT-PCR. The effect of hsa-circ_0058106 silencing on the metastasis of laryngeal cancer was assessed using scratch wound healing and transwell assays, as well as nude mouse lung metastasis models. Fluorescence in situ hybridization was employed to analyze the cellular localization of hsa-circ_0058106. A luciferase activity assay was used to assess binding between hsa-circ_0058106 and miR-153. Interaction between hsa-circ_0058106 and Twist1 was confirmed using RNA pull-down and RNA immunoprecipitation assays.

RESULTS

A high level of hsa-circ_0058106 was found to be associated with lymph node metastasis and advanced clinical stages. Stable knockdown of hsa-circ_0058106 inhibited the migration and invasion of laryngeal cancer cells in vitro and in vivo. Moreover, we found that downregulation of hsa-circ_0058106 suppressed epithelial-mesenchymal transition (EMT), which was underscored by the observation that hsa-circ_0058106 silencing led to decreases in the expression of N-cadherin and Vimentin, and an increase in the expression of E-cadherin. Mechanistically, we found that hsa-circ_0058106 can specifically bind to miR-153 and regulate Snail1 expression by acting as a miR-153 sponge. In addition, we found that knockdown of hsa-circ_0058106 blocked the nuclear translocation of Twist1.

CONCLUSIONS

Our results indicate that hsa-circ_0058106 induces EMT and metastasis in laryngeal cancer by sponging miR-153 and inducing Twist1 nuclear translocation. These observations provide new insights into the regulatory effects of circRNAs in laryngeal cancer metastasis.

Hsa_circ_0042823 accelerates cancer progression via miR-877-5p/FOXM1 axis in laryngeal squamous cell carcinoma

BACKGROUND

Laryngeal squamous cell carcinoma (LSCC) is a common malignant tumour of the head and neck. Our previous study reveals that the circular RNA (circRNA) hsa_circ_0042823 is abnormally expressed in LSCC, suggesting that hsa_circ_0042823 is closely associated with LSCC. Here, we attempted to explore the molecular mechanism of hsa_circ_0042823 in LSCC.

METHODS

Quantitative real-time PCR and western blot were performed to assess the expression of gene and protein in human laryngeal carcinoma cells, TU212 and TU686. MTT and transwell assays were performed to examine cell proliferation, migration and invasion. The relationship among hsa_circ_0042823, miR-877-5p and forkhead box M1 (FOXM1) was verified by luciferase reporter assay. Finally, we constructed a subcutaneous tumour mouse model to analyse in vivo growth of LSCC cells following knockdown of hsa_circ_0042823.

RESULTS

Compared with normal human bronchial epithelial cells (HBECs), hsa_circ_0042823 was highly expressed in the LSCC cell lines (AMC-HN-8 and TU686). Further studies demonstrated that hsa_circ_0042823 interacted with miR-877-5p, and FOXM1 was the target of miR-877-5p. Hsa_circ_0042823 promoted the expression of FOXM1 via its ceRNA activity on miR-877-5p. Hsa_circ_0042823 overexpression promoted proliferation, migration and invasion of AMC-HN-8 cells through regulating miR-877-5p/FOXM1 axis. Additionally, inhibition of hsa_circ_0042823 inhibited growth of LSCC in vivo via miR-877-5p/FOXM1 axis.

CONCLUSIONS

Hsa_circ_0042823/miR-877-5p/FOXM1 axis participates in the progression of LSCC. This work demonstrates that hsa_circ_0042823 accelerates cancer progression by regulating miR-877-5p/FOXM1 axis in LSCC. Therefore, this study may provide new insights into the pathogenesis of LSCC.KEY MESSAGESHsa_circ_0042823 promotes FOXM1 expression by sponging miR-877-5p.Hsa_circ_0042823 promotes proliferation, migration, invasion of LSCC cells.Hsa_circ_0042823 knockdown inhibits tumour growth of LSCC via miR-877-5p/FOXM1 axis.

CircRNAs: a family number of miRNA regulatory transcriptome in laryngeal carcinoma

Laryngeal carcinoma (LC) is a common head and neck cancer, which is the result of mutational changes due to gene dysregulation and etiological factors such as tobacco and smoking. A large number of patients received a poor prognosis due to diagnosis at an advanced stage. This highlights the need for definitive, early, and efficient diagnoses. With rapid development of high‐throughput sequencing, circular RNA (circRNA) has been reported to play a pivotal role in cancer. CircRNA functions as a microRNA (miRNA) sponge in the regulation of mRNA expression, forming circRNA‐miRNA regulatory axis. In this review, we described the axis in LC. The result indicated that CDR1as, hsa_circ_0042823, hsa_circ_0023028, circPARD3, hsa_circ_103862, hsa_circ_0000218, circMYLK, circCORO1C, hsa_circ_100290, circ‐CCND1, hsa_circ_0057481, circFLAN, and circRASSF2 expressed higher in LC, whereas, hsa_circ_0036722 and hsa_circ_0042666 expressed lower. The circRNAs regulated the target genes by sponging miRNAs and contributed to the pathogenesis of LC.

circFLNA promotes glioblastoma proliferation and invasion by negatively regulating miR‑199‑3p expression

Glioblastoma (GBM) is one of the most common and malignant types of primary cancer in the central nervous system; however, the clinical outcomes of patients with GBM remain poor. Circular RNAs (circRNAs) have been revealed to serve important roles in diverse biological processes, such as regulating cell proliferation, epithelial-mesenchymal transition and tumor development. However, the underlying biological function of circRNA filamin A (circFLNA) and its potential role in GBM remain to be determined. The present study aimed to identify differentially expressed circRNAs in GBM. Reverse transcription-quantitative PCR was used to analyze the expression levels of circFLNA. The results demonstrated that the expression levels of circFLNA were significantly upregulated in clinical GBM samples and GBM cells compared with adjacent healthy brain tissues and normal human astrocytes, respectively. The results of the Cell Counting Kit-8 and Transwell assays revealed that circFLNA knockdown significantly inhibited the proliferative and invasive abilities of GBM cell lines. Moreover, high circFLNA expression levels were associated with a worse prognosis in GBM. MicroRNA (miR)-199-3p was subsequently predicted to be target of circFLNA. The inhibitory effect of miR-199-3p on cell proliferation and invasion was partially reversed following circFLNA knockdown. In conclusion, the findings of the present study identified novel roles for circFLNA in GBM and indicated that the circFLNA/miR-199-3p signaling axis may serve an important role in GBM progression. Therefore, circFLNA may represent a novel target for the diagnosis and treatment of GBM.

Analysis and Construction of a Competitive Endogenous RNA Regulatory Network of Baicalin-Induced Apoptosis in Human Osteosarcoma Cells

Background

Baicalin is an extract from the traditional Chinese herb Scutellaria baicalensis and has the potential to treat osteosarcoma (OS). However, the transcriptome-level mechanism of baicalin-mediated antitumor effects in OS has not yet been investigated. The aim of this study was to analyze the competitive endogenous RNA (ceRNA) regulatory network involved in baicalin-induced apoptosis of OS cells.

Methods

In this study, CCK-8 and flow cytometry assays were used to detect the antitumor effects of baicalin on human OS MG63 cells. Furthermore, transcriptome sequencing was employed to establish the long noncoding RNA (lncRNA), microRNA (miRNA), and mRNA profiles.

Results

Baicalin inhibited MG63 cell proliferation and induced apoptosis. Totals of 58 lncRNAs, 31 miRNAs, and 2136 mRNAs in the baicalin-treated MG63 cells were identified as differentially expressed RNAs compared to those in control cells. Of these, 2 lncRNAs, 3 miRNAs, and 18 mRNAs were included in the ceRNA regulatory network. The differentially expressed RNAs were confirmed by quantitative real-time PCR (qRT-PCR).

Conclusions

By identifying the ceRNA network, our results provide new information about the possible molecular basis of baicalin, which has potential applications in OS treatment.

A Comprehensive Evaluation of miR-144-3p Expression and Its Targets in Laryngeal Squamous Cell Carcinoma

Laryngeal squamous cell carcinoma (LSCC) is an aggressive type of head and neck squamous cell carcinoma (HNSCC) with a relatively high rate of morbidity and mortality. An altered miR-144-3p level in LSCC with a small number of patients has been previously reported. However, the clinical implication of miR-144-3p and its involved mechanism underlying this disease is not clearly elucidated. In this work, we aimed to confirm the expression of miR-144-3p with larger samples and also to identify target genes for the investigation of the underlying mechanism of miR-144-3p in LSCC. The levels of miR-144-3p were downregulated in 155 samples of LSCC tissues as compared to 26 non-LSCC samples (SMD: -0.78; 95% confidence interval (CI): -1.23, -0.32). The AUC of 0.90 in the summarized ROC curve also indicated a potential ability to differentiate LSCC from non-LSCC tissues, with a sensitivity of 0.78 and a specificity of 0.88. With respect to the molecular mechanism, we predicted the potential targets from online-based prediction, peer-reviewed publications, and RNA-seq and microarray data. In particular, the genes influenced by transfection with miR-144-3p in the LSCC FaDu cell line were collected from the microarray GSE56243. Lastly, 12 novel targets for miR-144-3p in LSCC were obtained by different algorithms. In conclusion, our study confirmed the loss or downregulation of miR-144-3p in LSCC, which might contribute to the LSCC tumorigenesis and progression via regulation of the 12 novel targets, such as IL24, ITGA6, and CEP55. In the future, further investigations are required to validate the present results.

Circular RNA ABCB10 contributes to laryngeal squamous cell carcinoma (LSCC) progression by modulating the miR-588/CXCR4 axis

Laryngeal squamous cell carcinoma (LSCC) is a common head and neck cancer with a high metastasis and poor prognosis. Circular RNAs (circRNAs) are a type of non-coding RNAs (ncRNAs) with regulatory function and broadly participate in cancer development. However, the correlation of circular RNA ABCB10 (circABCB10) with LSCC remains unclear. Here, we were interested in the role of circABCB10 in the modulation of LSCC progression. Our data demonstrated that the depletion of circABCB10 significantly inhibited the proliferation and induced the apoptosis of LSCC cells. Meanwhile, circABCB10 knockdown was able to remarkably reduce the invasion and migration of LSCC cells. Mechanically, circABCB10 served as a sponge for microRNAs-588 (miR-588) and miR-588 could target and down-regulated chemokine receptor 4 (CXCR4) expression in LSCC cells. The overexpression of CXCR4 or miR-588 inhibitor could reverse circABCB10 depletion-attenuated malignant phenotypes of LSCC cells. Functionally, the depletion of circABCB10 alleviated the tumor growth of LSCC cells in the tumorigenicity analysis of nude mice. The CXCR4 expression was decreased while the miR-588 expression was enhanced by circABCB10 depletion in vivo. Thus, we concluded that circABCB10 was involved in the malignant progression of LSCC by regulating miR-588/CXCR4 axis. Our finding provides new insights into the mechanism of circRHOT1 contributing to the development of LSCC. CircABCB10 and miR-588 may be used as potential targets for the treatment of LSCC.

Research Progress of circRNAs in Head and Neck Cancers

Circular RNAs (circRNAs) are a novel type of non-coding RNAs. Because of their characteristics of a closed loop structure, disease- and tissue-specificity, and high conservation and stability, circRNAs have the potential to be biomarkers for disease diagnosis. Head and neck cancers are one of the most common malignant tumors with high incidence rates globally. Affected patients are often diagnosed at the advanced stage with poor prognosis, owing to the concealment of anatomic sites. The characteristics, functions, and specific mechanisms of circRNAs in head and neck cancers are increasingly being discovered, and they have important clinical significance for the early diagnosis, treatment, and prognosis evaluation of patients with cancer. In this study, the generation, characteristics, and functions of circRNAs, along with their regulatory mechanisms in head and neck cancers have been summarized. We report that circRNAs interact with molecules such as transcription and growth factors to influence specific pathways involved in tumorigenesis. We conclude that circRNAs have an important role to play in the proliferation, invasion, metastasis, energy and substance metabolism, and treatment resistance in cancers.

Testicular orphan receptor 4 (TR4) promotes papillary thyroid cancer invasion via activating circ-FNLA/miR-149-5p/MMP9 signaling

The incidence and mortality of papillary thyroid cancer (PTC) have steadily increased. Although conventional therapies are very effective toward differentiated PTC patients, very limited therapeutic options are applicable to those patients with distant metastases. Therefore, better understanding of the molecular biology of metastatic PTC helps identify novel targets and facilitates the development of new therapies. In this study, we first found that testicular orphan receptor 4 (TR4) was significantly increased in PTC tumors spreading to lymph nodes compared to the paired primary tumors. Experimental evidence suggested that TR4 drove PTC progression via promoting its cell invasion and cell migration. Mechanistically, TR4 transcriptionally regulated the expression level of circ-filamin A (FLNA), which competed with matrix metalloproteinase 9 (MMP9) for microRNA (miR)-149-5p binding and led to an increased protein level of MMP9. Interruption assays with various gene manipulations verified that the TR4/circ-FLNA/miR-149-5p/MMP9 signaling axis played a central role in cell invasion and cell migration of PTC cells. Moreover, a xenografted mouse model also confirmed that the TR4/circ-FLNA signal promoted PTC tumor growth. Overall, our study pinpoints the oncogenic role of TR4 in PTC development, and the targeting of TR4/circ-FLNA/miR-149-5p/MMP9 signaling may be an alternative option for metastatic PTC patients.

Circ_0023028 contributes to the progression of laryngeal squamous cell carcinoma by upregulating LASP1 through miR-486-3p

Circular RNAs (circRNAs) are implicated in the tumorigenesis of human cancers. However, the effects of circRNAs on laryngeal squamous cell carcinoma (LSCC) are largely unknown. Here, we aimed to explore the roles of circ_0023028 in LSCC development. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to measure circ_0023028, miR-486-3p, and Lin-Isl-Mec (LIM) and SH3 domain protein 1 (LASP1) mRNA. The characteristics of circ_0023028 were determined by RNase R digestion assay and Actinomycin D assay. Cell Counting Kit-8 (CCK-8) assay and colony formation assay were utilized for cell proliferation. Transwell assay was adopted for cell invasion and migration. Flow cytometry analysis was carried out to analyze cell cycle and apoptosis. RNA pull-down assay and dual-luciferase reporter assay were used to explore the association between miR-486-3p and circ_0023028 or LASP1. Western blot assay was adopted to measure LASP1 protein level. Murine xenograft model was executed to investigate the function of circ_0023028 in vivo. High expression of circ_0023028 was observed in LSCC tissues and cells. Circ_0023028 was stable and possessed a loop structure. Circ_0023028 silencing suppressed LSCC cell proliferation, metastasis and cell cycle process and induced apoptosis in vitro and hampered tumor growth in vivo. Further mechanism analysis demonstrated that circ_0023028 could sponge miR-486-3p to regulate LASP1 expression in LSCC cells. The malignant behaviors of LSCC cells mediated by circ_0023028 knockdown were rescued by the inhibition of miR-486-3p. Moreover, miR-486-3p suppressed LSCC cell progression via binding to LASP1. Circ_0023028 knockdown might impede the progression of LSCC by regulating miR-486-3p/LASP1 axis, which could provide a novel insight on the mechanism of LSCC progression.

The function and pathogenic mechanism of filamin A

Filamin A(FLNa) is an actin-binding protein, which participates in the formation of the cytoskeleton, anchors a variety of proteins in the cytoskeleton and regulates cell adhesion and migration. It is involved in signal transduction, cell proliferation and differentiation, pseudopodia formation, vesicle transport, tumor resistance and genetic diseases by binding with interacting proteins. In order to fully elucidate the structure, function and pathogenesis of FLNa, we summarized all substances which directly or indirectly act on FLNa so far, upstream and downstream targets which having effect on it, signaling pathways and their functions. It also recorded the expression and effect of FLNa in different diseases, including hereditary disease and tumors.

Regulatory Effects of Circular RNAs on Host Genes in Human Cancer

Circular RNAs (circRNAs) are a class of single-stranded, covalent closed-loop RNAs with tissue-/development-specific expression patterns. circRNAs are stable and play oncogenic or tumor suppressive roles in various aspects of cancer, including tumorigenesis, proliferation, apoptosis, metastasis, invasion, chemo-therapeutic resistance, and prognosis. circRNAs act as miRNA/protein sponges, protein scaffold, or template for translation. Increasing evidence shows circRNAs contribute to cancer progression via modulating the expression or function of their host genes. In this review, we summarize the latest progress in the regulation of host genes by circRNAs in human cancer. The works on circRNAs mediated regulation of host genes enhance us to understand the interaction between circRNAs and their host genes in human cancer.

Molecular Tuning of Filamin A Activities in the Context of Adhesion and Migration

The dynamic organization of actin cytoskeleton meshworks relies on multiple actin-binding proteins endowed with distinct actin-remodeling activities. Filamin A is a large multi-domain scaffolding protein that cross-links actin filaments with orthogonal orientation in response to various stimuli. As such it plays key roles in the modulation of cell shape, cell motility, and differentiation throughout development and adult life. The essentiality and complexity of Filamin A is highlighted by mutations that lead to a variety of severe human disorders affecting multiple organs. One of the most conserved activity of Filamin A is to bridge the actin cytoskeleton to integrins, thereby maintaining the later in an inactive state. We here review the numerous mechanisms cells have developed to adjust Filamin A content and activity and focus on the function of Filamin A as a gatekeeper to integrin activation and associated adhesion and motility.

Identification of Early Recurrence Factors in Childhood and Adolescent B-Cell Acute Lymphoblastic Leukemia Based on Integrated Bioinformatics Analysis

Over the past 50 years, great progress has been made in the diagnosis and treatment of acute lymphoblastic leukemia (ALL), especially in pediatric patients. However, early recurrence is still an important threat to the survival of patients. In this study, we used integrated bioinformatics analysis to look for biomarkers of early recurrence of B-cell ALL (B-ALL) in childhood and adolescent patients. Firstly, we obtained gene expression profiles from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database and the Gene Expression Omnibus (GEO) database. Then, we identified differentially expressed genes (DEGs) based on whether the disease relapsed early. LASSO and Cox regression analysis were applied to identify a subset of four genes: HOXA7, S100A11, S100A10, and IFI44L. A genetic risk score model was constructed based on these four optimal prognostic genes. Time-dependent receiver operating characteristic (ROC) curves were used to evaluate the predictive value of this prognostic model (3-, 5-, and 10-year AUC values >0.7). The risk model was significantly associated with overall survival (OS) and event-free survival in B-ALL (all p < 0.0001). In addition, a high risk score was an independent poor prognostic risk factor for OS (p < 0.001; HR = 3.396; 95% CI: 2.387-4.832). Finally, the genetic risk model was successfully tested in B-ALL using an external validation set. The results suggested that this model could be a novel predictive tool for early recurrence and prognosis of B-ALL.

Circular RNAs: Emerging Role in Cancer Diagnostics and Therapeutics

Circular RNAs (circRNAs) are rapidly coming to the fore as major regulators of gene expression and cellular functions. They elicit their influence via a plethora of diverse molecular mechanisms. It is not surprising that aberrant circRNA expression is common in cancers and they have been implicated in multiple aspects of cancer pathophysiology such as apoptosis, invasion, migration, and proliferation. We summarize the emerging role of circRNAs as biomarkers and therapeutic targets in cancer.

CircFLNA Acts as a Sponge of miR-646 to Facilitate the Proliferation, Metastasis, Glycolysis, and Apoptosis Inhibition of Gastric Cancer by Targeting PFKFB2

Background

Many studies have confirmed that circular (circRNA) is involved in the development of gastric cancer (GC). However, the role of circFLNA in the progression of GC remains unclear.

Methods

Quantitative real-time PCR (qRT-PCR) was used to measure the relative expression of circFLNA, microRNA (miR)-646 and 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 2 (PFKFB2). Cell counting kit 8 (CCK8) assay, transwell assay and flow cytometry were performed to determine the proliferation, migration, invasion and apoptosis of cells, respectively. GC tumor xenograft models were built to confirm the function of circFLNA silencing on GC tumor growth in vivo. Furthermore, the lactate production, glucose consumption, ATP level and glucose uptake were detected to assess the glycolysis of cells. Then, the interaction between miR-646 and circFLNA or PFKFB2 was confirmed using dual-luciferase reporter assay. RNA immunoprecipitation (RIP) assay was used to verify the interaction between miR-646 and circFLNA further. In addition, Western blot (WB) analysis was employed to detect the relative protein expression of PFKFB2.

Results

Our results found that circFLNA was upregulated in GC tissues and cells. Silencing of circFLNA could suppress the proliferation, migration, invasion, glycolysis, and enhance the apoptosis of GC cells. Also, circFLNA knockdown reduced GC tumor volume and weight in vivo. Further experiments revealed that circFLNA could sponge miR-646, and miR-646 could target PFKFB2. The rescue experiments indicated that miR-646 inhibitor could reverse the suppressive effect of circFLNA silencing on GC progression, and PFKFB2 overexpression also could invert the inhibition effect of miR-646 on GC progression.

Conclusion

Our data concluded that circFLNA played a pro-cancer role in GC, which suggested that circFLNA might be a potential biomarker for GC treatment.

circRNAome Profiling in Oral Carcinoma Unveils a Novel circFLNB that Mediates Tumour Growth-Regulating Transcriptional Response

Deep sequencing technologies have revealed the once uncharted non-coding transcriptome of circular RNAs (circRNAs). Despite the lack of protein-coding potential, these unorthodox yet highly stable RNA species are known to act as critical gene regulatory hubs, particularly in malignancies. However, their mechanistic implications in tumor outcome and translational potential have not been fully resolved. Using RNA-seq data, we profiled the circRNAomes of tumor specimens derived from oral squamous cell carcinoma (OSCC), which is a prevalently diagnosed cancer with a persistently low survival rate. We further catalogued dysregulated circRNAs in connection with tumorigenic progression. Using comprehensive bioinformatics analyses focused on co-expression maps and miRNA-interaction networks, we delineated the regulatory networks that are centered on circRNAs. Interestingly, we identified a tumor-associated, pro-tumorigenic circRNA, named circFLNB, that was implicated in maintaining several tumor-associated phenotypes in vitro and in vivo. Correspondingly, transcriptome profiling of circFLNB-knockdown cells showed alterations in tumor-related genes. Integrated in silico analyses further deciphered the circFLNB-targeted gene network. Together, our current study demarcates the OSCC-associated circRNAome, and unveils a novel circRNA circuit with functional implication in OSCC progression. These systems-based findings broaden mechanistic understanding of oral malignancies and raise new prospects for translational medicine.

MicroRNA expression in relation with clinical evolution of osteosarcoma

Osteosarcoma is the most common malignant bone tumor. Early diagnosis remains a major challenge, mainly because of the lack of specific biomarkers. We performed miRNAs expression analysis through qPCR in affected and paired healthy bone derived from osteosarcoma patients. Hierarchical clustering using the top ten miRNAs with differential expression showed two main clusters. One integrated by patients with the presence of metastasis or relapse and the other without these complications. Further pathway enrichment analysis reduced to four main miRNAs, hsa-miR-486-3p, hsa-miR-355-5p, hsa-miR-34a-5p and hsa-miR-1228-3p. Afterwards, we compared patients with and without metastasis, the function enrichment analysis along with review of relevant literature, showed that hsa-miR-93-5p and hsa-miR-28-5p were associated with metastasis development. Our results support the relevance of miRNAs in the pathogenesis of osteosarcoma and contribute with evidence regarding the potential role of miRNAs as potential biomarkers. More studies are needed to define the most informative miRNAs in osteosarcoma patients.

CircRNAs: potency of protein translation and feasibility of novel biomarkers and therapeutic targets for head and neck cancers

Circular RNAs (circRNAs), a new star noncoding RNA (ncRNA), show stability, conservation, abundance, and tissue and stage specificity. They act as key regulators of biological processes. They target the mRNAs of many other different genes or signaling pathways, and closely link associated genes into regulatory networks. Growing evidence has demonstrated that circRNAs may play an important role in the carcinogenesis, progression and chemoradiation resistance of many cancers including head and neck cancers (HNC). CircRNA, like other ncRNA, such as miRNA, lncRNA, usually is considered to be non-protein coding transcript. However, recent studies indicated that abnormal translation of circRNAs may be involved in human diseases. In this review, we collected the origin, classification, characteristics, function of circRNAs, exosmal circRNAs, and then synthesize current study results to highlight aberration of circRNAs in various types of HNC, and try to clarify the molecular mechanisms of circRNAs affecting the pathogenesis and progression of HNC, as well as pay particular attention to provide a new avenue to the diagnosis and treatment strategy for HNC.

Functional and Clinical Impact of CircRNAs in Oral Cancer

The increasing number of recently published works regarding the role of circular RNAs (circRNAs) in oral cancer highlights the key contribution of this novel class of endogenous noncoding RNAs as regulators of critical signaling pathways and their clinical value as novel biomarkers. This review summarizes and puts into context the existing literature in order to clarify the relevance of circRNAs as novel mediators of oral cancer pathogenesis as well as their potential usefulness as predictors of clinical outcome and response to therapy in this disease.

Overexpression of circRNA_100290 promotes the progression of laryngeal squamous cell carcinoma through the miR-136-5p/RAP2C axis

Circular RNAs (circRNAs) exert critical functions in tumorigenesis and tumor development, but whether and how circRNAs contribute to laryngeal squamous cell carcinoma (LSCC) is unclear. In this study, we explored the function and mechanisms of circRNA_100290 in LSCC. Tissue samples were obtained from 40 patients with LSCC. The expression of circRNA_100290 and other targets was measured through quantitative reverse transcription-polymerase chain reaction and western blot analysis. Cell proliferation, colony-forming ability, and apoptosis were tested using CCK-8 assay and EdU assay, colony formation assay, and flow cytometry, respectively. Cell migration and invasion were detected by Transwell assay. Moreover, the interactions between circRNA_100290, miR-136-5p, and RAP2C were analyzed by bioinformatics, and verified by dual-luciferase reporter assays. Here, we found that circRNA_100290 expression was significantly upregulated in LSCC tissues and cell lines compared with the normal controls. Expression of circRNA_100290 positively correlated with advanced TNM stage and lymph node metastasis in LSCC patients. In cell culture, upregulation of circRNA_100290 promoted LSCC cell proliferation, migration, and invasion, while it inhibited cell apoptosis; downregulating circRNA_100290 exerted the opposite effects. In vivo, circRNA_100290 overexpression dramatically promoted tumor growth. Mechanistically, circRNA_100290 may act as a sponge of miR-136-5p, and inhibiting miR-136-5p in LSCC cells indeed reversed the effects of circRNA_100290 downregulation. The RAS oncogene RAP2C was predicted to be a target of miR-136-5p, and downregulating RAP2C in LSCC cells partially reversed the oncogenic effects of circRNA_100290 overexpression or miR-136-5p decrease. Our findings suggest that circRNA_100290 promotes LSCC progression by targeting the miR-136-5p/RAP2C axis, which may lead to the identification of potential therapeutic targets.

Silencing of miR-17-5p suppresses cell proliferation and promotes cell apoptosis by directly targeting PIK3R1 in laryngeal squamous cell carcinoma

Background

Increasing evidence has suggested that microRNAs (miRNAs) act as key post-transcriptional regulators in tumor progression. Previous studies have confirmed that miR-17-5p functions as an oncogene in multiple cancers and contributes to tumor progression. However, the role and biological functions of miR-17-5p in the development of laryngeal squamous cell carcinoma (LSCC) still remain unknown.

Methods

qRT-PCR was used to detect miRNA and mRNA expression levels in LSCC tissues and cell lines. CCK-8 assay was used to measure cell viability and flow cytometry was performed to evaluate cell apoptosis. Western blot analysis was used to detect the protein levels of BAX, BCL-2, cleaved Caspase-3, PIK3R1 and AKT. Luciferase reporter assay was used to detect the effect of miR-17-5p on PIK3R1 expression. Xenograft animal model was used to test the effect of miR-17-5p on LSCC cell in vivo.

Results

In the present study, we found that miR-17-5p expression level was upregulated in LSCC tissues and cell lines. Depletion of miR-17-5p in LSCC cells significantly reduced cell proliferation and promoted cell apoptosis in vitro and in vivo. Mechanically, knockdown of miR-17-5p in LSCC cells inhibited BCL-2 expression while enhanced BAX and cleaved Caspase-3 protein expression. Moreover, depletion of miR-17-5p in LSCC cells suppressed AKT phosphorylation but did not influence PTEN expression. Importantly, miR-17-5p positively regulated PIK3R1 expression by directly binding to its 3′-untranslated region (UTR). Additionally, PIK3R1, which expression was downregulated in LSCC tissues and cell lines, was involved in LSCC cell survival by modulating the activation of AKT signal pathway. Dysregulation of miR-17-5p/PIK3R1 axis was participated in LSCC cell proliferation and apoptosis by inhibiting the activation of the PI3K/AKT signaling pathway.

Conclusions

In conclusion, our study indicates that the miR-17-5p/PIK3R1 axis plays an essential role in the development of LSCC and provides a potential therapeutic target for LSCC treatment.

MicroRNA-486-5p and microRNA-486-3p: Multifaceted pleiotropic mediators in oncological and non-oncological conditions

Despite historically known as "junk" DNA, nowadays non-coding RNA transcripts (ncRNAs) are considered as fundamental players in various physiological and pathological conditions. Nonetheless, any alteration in their expression level has been reported to be directly associated with the incidence and aggressiveness of several diseases. MicroRNAs (miRNAs) are the well-studied members of the ncRNAs family. Several reports have highlighted their crucial roles in the post-transcriptional manipulation of several signaling pathways in different pathological conditions. In this review, our main focus is the multifaceted microRNA-486 (miR-486). miR-486-5p and miR-486-3p have been reported to have central roles in several types oncological and non-oncological conditions such as lung, liver, breast cancers and autism, intervertebral disc degeneration and metabolic syndrome, respectively. Moreover, we spotted the light onto the pleiotropic role of miR-486-5p in acting as competing endogenous RNA with other members of ncRNAs family such as long non-coding RNAs.