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

MiR-136-5p in cancer: Roles, mechanisms, and chemotherapy resistance

MicroRNAs (miRNAs) have emerged as important regulators of gene expression, and the deregulation of their activity has been linked to the onset and progression of a variety of human malignancies. Among these miRNAs, miR-136-5p has attracted significant attention due to its diverse roles in cancer biology. Mostly, miR-136-5p is downregulated in malignancies. It could inhibit viability, proliferation, migration, invasion and promote apoptosis of tumor cells. This review article provides a comprehensive overview of the current understanding of miR-136-5p in different sorts of human cancers: genital tumors, head and neck tumors, tumors from the digestive and urinary systems, skin cancers, neurologic tumors, pulmonary neoplasms and other cancers by discussing its molecular mechanisms, functional roles, and impact in chemotherapies. In conclusion, miR-136-5p could be a promising new biomarker and potential clinical therapeutic target.

A novel microRNA panel exhibited significant potential in evaluating the progression of laryngeal squamous cell carcinoma

Background

Laryngeal squamous cell carcinoma (LSCC) is a common cancer of the head and neck in humans. The 5-years survival rate of patients with LSCC have declined in the past four decades. microRNAs (miRNAs) has been reported to be capable of predicting the prognosis outcomes of patients with different cancers. However, there are no reports on the usage of multi-miRNAs model as signature for the diagnosis or prognosis of LSCC.

Methods

To establish the miRNAs expression-associated model for diagnosis, prognosis prediction and aided therapy of patients with LSCC, the present study enrolled 107 patients with LSCC in clinic and obtained 117 LSCC samples data from TCGA database for evaluation, respectively. Next generation sequencing (NGS), raw data processing, the least absolute shrinkage and selection operator algorithm, Cox regression analysis, construction of nomogram and cell function assays (including proliferation, migration and invasion assays) were sequentially performed.

Results

There were massively dysregulated miRNAs in the LSCC compared to normal tissues. A six-miRNAs signature consists of miR-137-3p, miR-3934-5p, miR-1276, miR-129-5p, miR-7-5p and miR-105-5p was built for prognosis prediction of LSCC patients. The six-miRNAs signature is strongly associated with the poor overall survival (OS, p = 2.5e-05, HR: 4.30 [2.20-8.50]), progression free interval (PFI, p = 0.025, HR: 1.94 [1.08-3.46]) and disease specific survival (DSS, p = 1.1e-05, HR: 5.00 [2.50-10.00]). A nomogram for prediction of 2-, 3- and 5-years OS was also developed based on the six-miRNAs signature and clinical features. Furthermore, blocking the function of each of the six miRNAs inhibited proliferation, invasion and migration of LSCC cells.

Conclusions

The performance of six-miRNAs signature described in the current study demonstrated remarkable potential for progression assessment of LSCC. Moreover, the six-miRNAs signature may serve as predictive tool for prognosis and therapeutic targets of LSCC in clinic.

miR-136-5p: A key player in human cancers with diagnostic, prognostic and therapeutic implications

MiRNAs have emerged as crucial modulators of the expression of their target genes, attracting significant attention due to their engagement in various cellular processes, like cancer onset and development. Amidst the extensive repertoire of miRNAs implicated in cancer, miR-136-5p has emerged as an emerging miRNA with diverse roles. Dysregulation of miR-136-5p has been proved in human cancers. Accumulating evidence suggests that miR-136-5p mainly functions as a tumor suppressor. These data proposed that miR-136-5p is engaged in the regulation of various cellular processes, like cell proliferation, migration, invasion, EMT, and apoptosis. In addition, miR-136-5p has demonstrated substantial potential as a prognostic and diagnostic marker in human cancers as well as an effective mediator in cancer chemotherapy. Furthermore, miR-136-5p was shown to be correlated with clinicopathological features of affected patients, proposing that it could be used for cancer staging and patient survival. Therefore, a comprehensive comprehension of the precise molecular basis governing miR-136-5p dysregulation in different cancers is vital for unraveling its therapeutic importance. Here, we have discussed the molecular basis of miR-136-5p as a potential tumor suppressor as well as its importance in cancer diagnosis, prognosis, and chemotherapy. Finally, we have discussed the challenge of using miRNAs as a therapeutic target as well as the prospect regarding the importance of miR-136-5p in human cancers.

CircPRRC2C Promotes the Oncogenic Phenotypes of Laryngeal Squamous Cell Carcinoma Cells via MiR-136-5p/HOXD11 Axis

The involvement of circular RNAs (circRNAs) in laryngeal squamous cell carcinoma (LSCC) carcinogenesis has gradually been proposed. Herein, we aimed to explore the function and mechanism of circPRRC2C in LSCC. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used for detecting the content of genes and proteins. In vitro experiments were conducted using 5-ethynyl-2'-deoxyuridine, colony formation, flow cytometry, and transwell assays. The binding between miR-136-5p and circPRRC2C or Homeobox D11 (HOXD11) was confirmed by using the dual-luciferase reporter assay. The murine xenograft model was established for in vivo analysis. The commercial kit was used for exosome separation. CircPRRC2C is a stable circRNA, and was highly expressed in LSCC tissues and cell lines. Functionally, circPRRC2C deficiency impaired LSCC cell proliferation, migration and invasion but induced cell apoptosis in vitro and impeded tumor growth in vivo, however, circPRRC2C overexpression showed the exact opposite effects. Mechanistically, circPRRC2C directly targeted miR-136-5p, which showed inhibitory effects on the growth and mobility of LSCC cells. Meanwhile, miR-136-5p directly targeted HOXD11, and circPRRC2C/miR-136-5p/HOXD11 formed a feedback loop in LSCC cells. Further rescue assays exhibited that circPRRC2C exerted its effects by miR-136-5p/HOXD11 axis. In addition, circPRRC2C was stably packaged into exosomes and showed potential diagnostic value for LSCC. CircPRRC2C acted as an oncogene to promote LSCC cell oncogenic phenotypes via miR-136-5p/HOXD11 axis, besides, circPRRC2C was stably packaged into exosomes, indicating the potential application of circPRRC2C-targeting agents in the treatment in LSCC.

Diagnostic and Prognostic Value of microRNAs in Patients with Laryngeal Cancer: A Systematic Review

Laryngeal squamous cell cancer (LSCC) is one of the most common malignant tumors of the head and neck region, with a poor survival rate (5-year overall survival 50-80%) as a consequence of an advanced-stage diagnosis and high recurrence rate. Tobacco smoking and alcohol abuse are the main risk factors of LSCC development. An early diagnosis of LSCC, a prompt detection of recurrence and a more precise monitoring of the efficacy of different treatment modalities are currently needed to reduce the mortality. Therefore, the identification of effective diagnostic and prognostic biomarkers for LSCC is crucial to guide disease management and improve clinical outcomes. In the past years, a dysregulated expression of small non-coding RNAs, including microRNAs (miRNAs), has been reported in many human cancers, including LSCC, and many miRNAs have been explored for their diagnostic and prognostic potential and proposed as biomarkers. We searched electronic databases for original papers that were focused on miRNAs and LSCC, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. According to the outcome, 566 articles were initially screened, of which 177 studies were selected and included in the analysis. In this systematic review, we provide an overview of the current literature on the function and the potential diagnostic and prognostic role of tissue and circulating miRNAs in LSCC.

Circ_0091579 exerts an oncogenic role in hepatocellular carcinoma via mediating miR-136-5p/TRIM27

BACKGROUND

Circular RNAs (circRNAs) act as crucial regulators in tumorigenesis. In this study, the working mechanism of circ_0091579 in hepatocellular carcinoma (HCC) progression was investigated.

METHODS

The expression of RNA and protein was measured via RT-qPCR and Western blot assay. Cell proliferation ability was analyzed via CCK8, EdU and colony formation assays. Cell migration and invasion abilities were detected via transwell assays. Flow cytometry was applied to assess cell cycle and apoptosis. The target relation between miR-136-5p and circ_0091579 or tripartite motif containing 27 (TRIM27) was certified using dual-luciferase reporter assay. Xenograft tumor model was utilized to assess the role of circ_0091579 in tumor growth in vivo. The protein level of Ki67 in tumor tissues was analyzed by immunohistochemistry (IHC) assay.

RESULTS

Circ_0091579 expression was elevated in HCC tissues and cell lines. HCC patients with high circ_0091579 expression displayed low survival rate. Circ_0091579 knockdown suppressed the proliferation, migration, invasion, cell cycle progression and epithelial-mesenchymal transition (EMT) and induced apoptosis of HCC cells. Circ_0091579 acted as a molecular sponge for miR-136-5p, and circ_0091579 silencing-mediated effects were largely overturned by the knockdown of miR-136-5p in HCC cells. MiR-136-5p interacted with the 3' untranslated region (3'UTR) of TRIM27, and TRIM27 overexpression largely counteracted miR-136-5p overexpression-induced influences in HCC cells. Circ_0091579 sponged miR-136-5p to up-regulate TRIM27 expression in HCC cells. Circ_0091579 silencing suppressed xenograft tumor growth in vivo.

CONCLUSION

Circ_0091579 exhibited an oncogenic role to enhance the malignant potential of HCC cells through mediating miR-136-5p/TRIM27 axis in vitro and in vivo.

CircRNAs: Roles in regulating head and neck squamous cell carcinoma

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

CircSERPINA3 promoted cell proliferation, migration, and invasion of laryngeal squamous cell carcinoma by targeting miR-885-5p

CircSERPINA3 has been shown to be upregulated in laryngeal squamous cell carcinoma (LSCC); however, whether it regulates the development of LSCC and the specific molecular mechanism remains unclear, which is to be explored in this study. Expressions of circSERPINA3, miR-885-5p, and Malic enzyme 1 (ME1) in LSCC tissues or cell lines were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The regulation of circSERPINA3 on the biological behavior of LSCC cells was confirmed by loss and gain experiments (cell counting kit-8, transwell, and colony formation assay). The correlation between circSERPINA3/ME1 and miR-885-5p was predicted and confirmed by bioinformatics analysis, dual-luciferase reporter assay, and qRT-PCR. The effect of circSERPINA3/miR-885-5p axis on the biological behavior of LSCC cells and expressions of epithelial-mesenchymal transition-related proteins was confirmed by rescue experiments. CircSERPINA3 and ME1 was upregulated in LSCC tissues, whereas miR-885-5p was downregulated. MiR-885-5p was the target gene of circSERPINA3, whereas ME1 was the target gene of miR-885-5p. Silent circSERPINA3 suppressed viability, invasion, migration, colony formation, and expression of ME1, claudin-4, snail, and vimentin but elevated expression of miR-885-5p and E-cadherin, whereas overexpressed circSERPINA3 was the opposite. However, miR-885-5p inhibitor or mimic reversed the effects of silent circSERPINA3 or overexpressed circSERPINA3. Collectively, circSERPINA3 promotes proliferation, migration, and invasion of LSCC cells by targeting miR-885-5p.

MicroRNA-136-5p from Endothelial Progenitor Cells-released Extracellular Vesicles Mediates TXNIP to Promote the Dissolution of Deep Venous Thrombosis

OBJECTIVE

Endothelial progenitor cells-released extracellular vesicles (EPCs-EVs) have previously been reported to promote the dissolution of deep venous thrombosis (DVT) through delivery of microRNA (miR). Given that, this research was projected to search the relative action of EPCs-EVs transferring of miR-136-5p in DVT.

METHODS

From EPCs transfected with miR-136-5p agomir or antagomir, EVs were extracted and then injected into DVT mice. Meanwhile, based on the treatment with EPCs-EVs loading miR-136-5p antagomir, silenced thioredoxin-interacting protein (TXNIP) lentivirus was injected into DVT mice to perform the rescue experiments. Afterwards, the length and weight of venous thrombosis, EPC apoptosis and inflammatory factors, plasmin, fibrinogen, and thrombin-antithrombin were measured. miR-136-5p and TXNIP expression in DVT mice, and their targeting relationship were evaluated.

RESULTS

miR-136-5p expression was suppressed and TXNIP expression was elevated in DVT mice. EPCs-EV reduced the length and weight of venous thrombosis, suppressed cell apoptosis and inflammatory reaction, as well as elevated level of plasmin, and reduced levels of fibrinogen and thrombin-antithrombin in DVT mice. Restored miR-136-5p loaded by EPCs-EV further attenuated DVT but EPCs-EV transfer of depleted miR-136-5p resulted in the opposite consequences. miR-136-5p targeted TXNIP and silenced TXNIP rescued the effect of EPCs-EV transfer of depleted miR-136-5p on DVT.

CONCLUSION

miR-136-5p from EPCs-EV suppresses TXNIP expression to reduce the thrombus size in DVT, offering a promising treatment target for DVT.

Long non-coding RNA DSCAM-AS1 promotes pancreatic cancer progression via regulating the miR-136-5p/PBX3 axis

LncRNA down syndrome cell adhesion molecule antisense 1 (DSCAM-AS1) plays an important role in tumor progression, but its function in pancreatic cancer is unknown. DSCAM-AS1 level was evaluated by in situ hybridization (ISH) assay and qRT-PCR. DSCAM-AS1 was knocked down in pancreatic cancer cells, and its impacts on cell proliferation, invasion, and migration were detected. The binding relationship among DSCAM-AS1, miR-136-5p, and pre-B-cell leukemia homeobox 3 (PBX3) was investigated by bioinformatic analysis and luciferase reporter assay. An in vivo animal model was constructed to determine the role of DSCAM-AS1 in tumor growth. Our results showed that DSCAM-AS1 was elevated in tumor tissues of pancreatic cancer patients and cell lines. DSCAM-AS1 knockdown efficiently inhibited PANC-1 cell proliferation, migration, and invasion and suppressed tumor growth. DSCAM-AS1 could promote PBX3 expression by sponging miR-136-5p, and its function in pancreatic cancer was partially mediated by the miR-136-5p/PBX3 axis. Overall, DSCAM-AS1 knockdown inhibits pancreatic cancer progression by modulating the miR-136-5p/PBX3 axis.

hsa_circ_0023305 Enhances Laryngeal Squamous Cell Carcinoma Progression and Modulates TRPM7 via miR-218-5p Sponging

Recently, circular RNAs have been shown to function as critical regulators of many human cancers. However, the circRNA mechanism in laryngeal squamous cell carcinoma (LSCC) remains elusive. Recent investigations using bioinformatics analysis revealed high expression of hsa_circ_0023305 in LSCC tissues compared to normal tissues. Furthermore, we discovered that hsa_circ_0023305 expression level was positively correlated to tumor/node/metastasis (TNM) stage as well as lymph node metastasis in LSCC. Moreover, higher hsa_circ_0023305 levels were correlated to poorer LSCC patient outcomes. Knockdown of hsa_circ_0023305 significantly inhibited LSCC cell proliferation, invasion, and migration abilities. Our team validated that hsa_circ_0023305 functioned as a miR-218-5p sponge from a mechanistic perspective, targeting the melastatin-related transient receptor potential 7 (TRPM7) in LSCC cells. TRPM7 regulates a nonselective cation channel and promotes cancer proliferation and metastasis. Our data demonstrated that miR-218-5p was downregulated in LSCC and that miR-218-5p upregulation repressed LSCC proliferation and invasion both in vivo and in vitro. Additionally, we found that hsa_circ_0023305-mediated upregulation of TRPM7 inhibited miR-218-5p and contributed to LSCC migration, proliferation, and invasion. In summary, these data propose a new mechanism by which the hsa_circ_0023305/miR-218-5p/TRPM7 network enhances LSCC progression.

lncRNA MIR4435‑2HG promotes the progression of liver cancer by upregulating B3GNT5 expression

Several studies have indicated that dysregulation of long non-coding RNAs (lncRNAs) participates in the initiation and progression of cancer. The lncRNA MIR4435-2HG was previously reported to act as an oncogene in human cancer, including liver cancer. However, its role in the pathogenesis in liver cancer is largely unclear. The present study aimed to reveal the molecular mechanism by which MIR4435-2HG regulates liver cancer. The expression levels of MIR4435-2HG in liver cancer and adjacent normal tissues were analyzed using The Cancer Genome Atlas database. MIR4435-2HG expression was validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in cancer cells in vitro. The target genes of MIR4435-2HG were predicted using bioinformatics analysis. Interactions between miR-136-5p, MIR4435-2HG and B3GNT5 were detected using luciferase reporter assays, and their effects on cell viability, migration and invasion were assessed using Cell Counting Kit-8, wound healing and Transwell assays. The effects of miR-136-5p and MIR4435-2HG on B3GNT5 expression were confirmed by western blot analysis. The results revealed that MIR4435-2HG expression was upregulated in primary liver cancer and liver cancer cell lines, and was positively associated with advanced tumor stage, metastasis and poor prognosis in patients with liver cancer. Knockdown of MIR4435-2HG significantly inhibited the proliferation, migration and invasion of liver cancer cells. Furthermore, miR-136-5p was determined to be a direct target of MIR4435-2HG and suppressed MIR4435-2HG expression by binding with the seed region of the 3′-UTR of MIR4435-2HG in liver cancer cells. Functional studies showed that the inhibitory effects of MIR4435-2HG knockdown on cell proliferation, migration and invasion were significantly rescued by inhibiting miR-136-5p. Furthermore, the target gene, B3GNT5, of miR-136-5p was confirmed by bioinformatics analysis and RT-qPCR. In addition, B3GNT5 expression was regulated by the MIR4435-2HG/miR-136-5p axis. In conclusion, the present study indicated that MIR4435-2HG facilitated the progression of liver cancer via the MIR4435-2HG/miR-136-5p/B3GNT5 axis, which demonstrated that MIR4435-2HG may be a potential biomarker for the prognosis and treatment of liver cancer.

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.

CircPTK2 (hsa_circ_0003221) Contributes to Laryngeal Squamous Cell Carcinoma by the miR-1278/YAP1 Axis

Laryngeal cancer accounts for 20% of all head and neck malignancies. Laryngeal squamous cell carcinoma (LSCC) is the most common type of laryngeal cancer and is characterized by squamous differentiation, a high mortality rate, and poor prognosis. Accumulating studies have indicated that circular RNAs (circRNAs) are critical regulators in many cancers. CircPTK2 exerts an important regulatory role in several cancers. In this study, we aimed to elucidate the function of circPTK2 (hsa_circ_0003221) in LSCC. Through a series of investigations, we discovered that circPTK2 was significantly upregulated in LSCC tissues cells. Functionally, cell counting kit-8 (CCK-8) and flow cytometry analyses revealed that knockdown of circPTK2 suppressed LSCC cell viability and the cell cycle while promoting cell apoptosis. Notably, silencing circPTK2 inhibited tumor growth in vivo. Mechanistically, circPTK2 functioned as a molecular sponge of miR-1278 to upregulate YAP1 expression in LSCC cells. Moreover, YAP1 knockdown inhibited malignant phenotypes of LSCC cells. The rescue experiments showed that YAP1 overexpression reversed the effects of circPTK2 on LSCC cells. Therefore, we concluded that circPTK2 facilitates LSCC progression through the miR-1278/YAP1 axis.

MicroRNA‑200c‑3p suppresses intervertebral disc degeneration by targeting RAP2C/ERK signaling

Intervertebral disc degeneration (IDD) is a major cause of lower back pain. The high morbidity associated with this disease diminishes the quality of life of those who are affected. MicroRNAs (miRs) play crucial roles in various diseases, including IDD. However, the mechanism via which miR‑200c‑3p plays a role in the development of IDD remains unknown. The present study aimed to investigate the effect of miR‑200c‑3p on the progression of IDD and the underlying mechanism. The expression level of miR‑200c‑3p was evaluated in intervertebral disc tissues from patients with IDD. To construct the IDD cell model, the nucleus pulposus (NP) cells were treated with lipopolysaccharide (LPS) 24 h following transfection with miR‑200c‑3p mimic or inhibitor. A luciferase activity assay was performed, while reverse transcription‑quantitative PCR and western blotting were conducted to determine the RNA and protein expression levels, respectively. The expression level of miR‑200c‑3p in the intervertebral disc tissues of patients with IDD was lower than that of normal subjects. LPS treatment reduced the expression level of miR‑200c‑3p in NP cells. Moreover, miR‑200c‑3p mimic inhibited LPS‑induced NP cell apoptosis. It was found that miR‑200c‑3p attenuated inflammatory cytokine levels and extracellular matrix (ECM) degradation in NP cells. Furthermore, miR‑200c‑3p targeted Ras‑related protein 2C (RAP2C) in NP cells. RAP2C promoted apoptosis, inflammatory cytokine levels and ECM degradation by activating ERK signaling. Knockdown of RAP2C and inhibition of ERK signaling by SCH772984 partially reversed the proinflammatory effect of the miR‑200c‑3p inhibitor on LPS‑treated NP cells. Thus, miR‑200c‑3p inhibits NP cell apoptosis, inflammatory cytokine levels and ECM degradation in IDD by targeting RAP2C/ERK signaling.

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.

Serum long non‑coding RNA NNT‑AS1 protected by exosome is a potential biomarker and functions as an oncogene via the miR‑496/RAP2C axis in colorectal cancer

Increasing evidence has indicated that long non-coding RNAs (lncRNAs) serve an essential role in carcinogenesis and cancer development. It has been reported that lncRNA nicotinamide nucleotide transhydrogenase antisense RNA 1 (NNT-AS1) serves a crucial role in several types of cancer. However, the clinical significance of circulating NNT-AS1 expression in colorectal cancer (CRC) remains to be elucidated. The current study aimed to investigate the potential role of NNT-AS1 and the clinical significance of its serum expression levels in patients with CRC. The expression of NNT-AS1 was measured in 40 pairs of tumor and adjacent normal tissues from patients with CRC via reverse transcription-quantitative PCR. The serum expression levels of NNT-AS1 were assayed in an independent cohort of healthy controls and patients with CRC. The levels of NNT-AS1 were also compared between paired preoperative and postoperative serum samples. In addition, the presence of exosomal NNT-AS1 in serum was explored. Furthermore, the biological roles of NNT-AS1 were investigated in CRC cells in vitro. The expression of NNT-AS1 was significantly upregulated in tumor tissues compared with adjacent normal tissues (P<0.05). A higher level of NNT-AS1 was associated with an advanced CRC stage. The serum levels of NNT-AS1 were significantly upregulated in patients with CRC compared with healthy subjects (P<0.05). Furthermore, the NNT-AS1 levels were significantly decreased in postoperative samples compared with preoperative samples (P<0.01). In addition, it was also identified that NNT-AS1 was upregulated in CRC exosomes (P<0.01), whereas no significant difference was observed in NNT-AS1 levels between serum and exosomes. Silencing of NNT-AS1 inhibited the proliferation, migration and invasion of CRC cells. It was also identified that NNT-AS1 exerted its effects via regulation of the microRNA-496/Ras-related protein Rap-2c axis. The present study demonstrated that circulating NNT-AS1, which may be protected by exosomes, could be a novel potential biomarker and therapeutic target in CRC.

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.

Role and mechanism of action of circular RNA and laryngeal cancer

Laryngeal squamous cell carcinoma (LSCC), is the second most common malignant cancer of the head and neck after oral cavity cancer. Laryngeal cancer is associated with huge socio-economic burden worldwide. Studies have widely explored the role of non-coding RNAs, especially microRNAs and long non-coding RNAs in pathogenesis of laryngeal cancer. In addition, several studies have explored the mechanism and function of circRNAs. CircRNAs has higher stability and more extensive function models, including combining miRNA as sponge, modifying transcription, and even regulating protein translation have been developed. Therefore, circRNAs is applied as an excellent diagnostic tool and a promising candidate for development of cancer therapies. This study reviews the biogenesis and function of circRNAs, explores potential mechanism of circRNAs in LSCC, and implications and challenges in LSCC research.

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.

The miR-136-5p/ROCK1 axis suppresses invasion and migration, and enhances cisplatin sensitivity in head and neck cancer cells

Laryngeal squamous cell carcinoma (LSCC) and hypopharyngeal squamous cell carcinoma (HPSCC) are two types of head and neck cancers with high incidence rates and relatively poor prognoses. The aim of the present study was to determine the effects of microRNA (miR/miRNA)-136-5p and its downstream target, Rho-associated coiled-coil containing protein kinase 1 (ROCK1), on LSCC and HPSCC progression and cisplatin sensitivity. The miRNA and protein expression levels in head and neck cancer cell lines were evaluated using reverse transcription-quantitative PCR and western blotting, respectively. MTT, wound healing assays, transwell assays and flow cytometry analysis were performed to measure cell properties. The binding between miR-136-5p and ROCK1 was detected using a dual-luciferase reporter assay. Autophagy double-labeled adenoviral infection assays were used to assess cell autophagy. The results showed that miR-136-5p was expressed in LSCC and HPSCC cells. Functional experiments showed that the expression of miR-136-5p in LSCC and HPSCC cells was negatively correlated with cell viability, invasion and migration. Additionally, miR-136-5p overexpression inhibited epithelial-mesenchymal transition, whereas miR-136-5p knockdown had the opposite effect. Dual-luciferase reporter assays confirmed the targeting relationship between miR-136-5p and ROCK1. miR-136-5p overexpression increased the cisplatin sensitivity of LSCC and HPSCC cells by reducing cell viability, as well as promoting cell apoptosis and autophagy. miR-136-5p overexpression decreased the expression levels of its downstream target ROCK1 and attenuated activity of the Akt/mTOR signaling pathway in cisplatin-treated LSCC and HPSCC cells. Conversely, miR-136-5p knockdown increased ROCK1 levels and decreased cisplatin sensitivity of the LSCC and HPSCC cells by increasing cell viability and inhibiting cell apoptosis, which was reversed by ROCK1 inhibition using the ROCK1 inhibitor, Y27632. Taken together, the results showed that the miR-136-5p/ROCK1 axis inhibits cell invasion and migration, and increases the sensitivity of LSCC and HPSCC cells to cisplatin.

Comprehensive in silico analysis for identification of novel candidate target genes, including DHX36, OPA1, and SENP2, located on chromosome 3q in head and neck cancers

BACKGROUND

Major milestones of head and neck carcinogenesis have been associated with various genetic abnormalities; however, a clear picture of the molecular networks deregulated during the carcinogenesis of head and neck squamous cell carcinoma (HNSC) has not yet completely revealed.

METHODS

In this study, we used in silico tools and online data sets to evaluate the underlying reasons for the expressional changes of genes residing within the chromosome 3q and to help understanding their contributions to HNSC carcinogenesis.

RESULTS

We found that 13 of 20 most upregulated genes in HNSC are localized to 3q. Further analysis revealed a gene signature consisting of DHX36, OPA1, and SENP2, which showed significant correlation in HNSC samples and potentially be deregulated through similar mechanisms including DNA amplification, transcriptional, and posttranscriptional regulation.

CONCLUSIONS

Considering our findings, we suggest DHX36, OPA1, and SENP2 genes as overexpressed in HNSC tumors and that might be concurrently involved in HNSC carcinogenesis, tumor progression, and induction of angiogenic pathways.

Circ_0000218 plays a carcinogenic role in laryngeal cancer through regulating microRNA-139-3p/Smad3 axis

BACKGROUND

Laryngeal squamous cell carcinoma (LSCC) accounts for about 85%-90% of all cases of laryngeal cancer. So far, the role and molecular mechanism of circular RNA 0,000,218 (circ_0000218)/microRNA (miR)-139-3p in laryngeal cancer are not clear. The present study aimed to investigate the role and regulatory mechanism of circ_0000218/miR-139-3p in laryngeal cancerin vitro and in vivo.

METHODS

quantitative real time polymerase chain reaction (qRT-PCR) was used to detect the expression of circ_0000218/miR-139-3p in LSCC cells. Dual luciferase reporter assay and RNA immunoprecipitation (RIP) assay were used to confirm binding sites between miR-139-3p and smad family member 3 (Smad3), and circ_0000218 and miR-139-3p. Cell Counting Kit-8 (CCK-8) and cell apoptosis analysis were used to detect cell viability and apoptosis. Xenograft experiment was performed to show in vivo effect of circ_0000218/miR-139-3p on the growth of LSCC.

RESULTS

Circ_0000218 was highly expressed in LSCC cells. miR-139-3p, lower expressed in LSCC cells, was negatively regulated by circ_0000218 in LSCC cells. Besides, the findings suggested that circ_0000218 silencing inhibited the LSCC cell viability and promoted apoptosis by negatively regulating miR-139-3p expression. Furthermore, the data indicated that miR-139-3p inhibited the viability of LSCC cells and promoted apoptosis, and these effects were reversed by Smad3 over-expression. In addition, the in vivo effects of circ_0000218/miR-139-3p on LSCC were consistent with the in vitro study.

CONCLUSIONS

circ_0000218 inhibition inhibited the growth of LSCC by targeting miR-139-3p/Smad3 axis. Our present study provided a new target for laryngeal cancer treatment.

Down-regulation of circ_0061140 attenuates ectopic endometrial cell proliferation, migration and invasion in endometriosis via inactivating Notch2

Endometriosis is a frequent gynecologic disease in the world. CircRNAs can exert a crucial role in various diseases. Nevertheless, little is known about its roles in endometriosis. We investigated the involvement of circ_0061140 in endometriosis. Tissues from endometriosis women displayed an increased expression of circ_0061140. Then, we found loss of circ_0061140 significantly repressed ectopic endometrial cell proliferation, migration and invasion. Meanwhile,miR-140-3pcan demonstrate an important role in several cancers.Here, we reported miR-140-3p was reduced in ectopic endometrial cells and it acted as a target of circ_0061140. Moreover, miR-140-3p was able to reverse the effect of circ_0061140 on ectopic endometrial cells. Furthermore, Notch2 was predicted as a putative target of miR-140-3p. A positive correlation between circ_0061140 and Notch2 was indicated. miR-140-3p and Notch2 were operated as downstream effectors in the circ_0061140 mediated signaling in endometriosis. Decrease of circ_0061140 could depress endometriosis progression through modulating miR-140-3p and Notch2.

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.