circPHIP promotes oral squamous cell carcinoma progression by sponging miR-142-5p and regulating PHIP and ACTN4 expression

Hsa_circ_0001615 downregulation inhibits esophageal cancer development through miR-142-5p/β-catenin

Background

Recent studies have found that circular RNAs (circRNAs) play important roles in tumorigenesis. This study aimed to determine the function and potential mechanisms of hsa_circ_0001615 in esophageal cancer.

Methods

Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was used to validate the expression of hsa_circ_0001615 and miR-142-5p. Subsequently, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt, flow cytometry, clone formation, and transwell assays were used to assess the function of hsa_circ_0001615. Furthermore, qRT-PCR and Western blot analysis were used to verify cyclin D1, Bcl-2 associated X, B-cell lymphoma/leukemia gene-2, and β-catenin levels. Circular RNA Interactome was used to estimate the binding site between hsa_circ_0001615 and miR-142-5p. Additionally, dual-luciferase reporter assays were used to determine whether miR-142-5p was a direct target of hsa_circ_0001615. Pearson correlation analysis was used to explore the relationship between miR-142-5p and hsa_circ_0001615.

Results

In esophageal cancer, the expressions of hsa_circ_0001615 and miR-142-5p were increased and decreased, respectively. Hsa_circ_0001615 inhibition significantly reduced the proliferation, migration, and invasion but increased the apoptosis of esophageal cancer cells. Additionally, hsa_circ_0001615 knockdown increased miR-142-5p expression but decreased β-catenin expression. MiR-142-5p was a direct target of hsa_circ_0001615.

Conclusion

Hsa_circ_0001615 knockdown could mediate antitumor effects through the miR-142-5p/β-catenin pathway.

Astragaloside IV regulates circ_0001615 and miR-873-5p/LASP1 axis to suppress colorectal cancer cell progression

Astragaloside IV (AS-IV) has exhibited pivotal anti-cancer efficacy in multiple types of cancer, including colorectal cancer (CRC). Meanwhile, circular RNA (circRNA) circ_0001615 has been reported to be involved in the malignant development of CRC. Herein, this study is expected to figure out the interaction between circ_0001615 and AS-IV on CRC progression. The 50% inhibition concentration (IC50), proliferation, apoptosis, and migration were detected by Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, and wound healing assays. The expression of related proteins was examined by western blot. Circ_0001615, microRNA-873-5p (miR-873-5p), and LIM and SH3 protein 1 (LASP1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). The binding between miR-873-5p and circ_0001615, or LASP1, was predicted by Starbase, followed by verification by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The biological role of circ_0001615 and AS-IV on CRC tumor growth was detected by the xenograft tumor model in vivo. According to the IC50 of AS-IV in CRC cells, the 100 ng/mL AS-IV treatment for 24 h was chosen for the following research: Our data confirmed that AS-IV is a beneficial anti-cancer agent in CRC cells. Furthermore, circ_0001615 and LASP1 expression were increased, and miR-873-5p was decreased in CRC patients and cell lines, whereas their expression exhibited an opposite trend in AS-IV-treated cells. Functionally, applying AS-IV might act as a beneficial anti-cancer effect by downregulating circ_0001615 in CRC cells in vitro. Mechanically, circ_0001615 serves as a sponge for miR-873-5p to affect LASP1 expression. In addition, AS-IV inhibited CRC cell growth in vivo by modulating circ_0001615. Overall, AS-IV could mitigate CRC development, at least in part, through the circ_0001615/miR-873-5p/LASP1 axis. These findings support a theoretical basis for an in-depth study of the function of AS-IV and the clinical treatment of CRC.

Propofol inhibits the proliferation, invasion, migration, and angiogenesis of oral squamous cell carcinoma through circ_0008898-mediated pathway

Propofol has been shown to inhibit oral squamous cell carcinoma (OSCC) progression. However, it is not clear whether propofol mediates OSCC progression through regulating circular RNA (circRNA) network. Quantitative real-time PCR was used to detect circ_0008898, miR-545-3p, and CT10 regulator of kinase-like protein (CRKL) expression. Cell functions were determined using CCK8 assay, Edu staining, MTT assay, transwell assay, wound healing assay, tube formation assay, and flow cytometry. Protein levels were examined by western blot analysis. RNA interaction was confirmed by dual-luciferase reporter assay and RIP assay. Our data showed that propofol repressed OSCC cell proliferation, invasion, migration, angiogenesis, and promoted apoptosis. circ_0008898 was highly expressed in OSCC, and its expression could be decreased by propofol. circ_0008898 silencing aggravated the suppressive effect of propofol on OSCC progression. In the mechanism, circ_0008898 could target miR-545-3p to positively regulate CRKL. MiR-545-3p inhibitor abolished the regulation of circ_0008898 silencing on propofol-mediated OSCC cell progression. MiR-545-3p inhibited the progression of propofol-treated OSCC cells, and this effect was reversed by CRKL overexpression. Also, circ_0008898 knockdown reduced OSCC tumor growth by regulating miR-545-3p/CRKL. In conclusion, propofol suppressed OSCC progression, which was achieved through regulating the circ_0008898/miR-545-3p/CRKL axis.

circNFATC3 facilitated the progression of oral squamous cell carcinoma via the miR-520h/LDHA axis

The aim of this study was to verify the effects of circular RNA nuclear factor of activated T-cells, cytoplasmic 3 (circNFATC3), in oral squamous cell carcinoma (OSCC) development. The levels of circNFATC3, microRNA-520h (miR-520h), and lactate dehydrogenase A (LDHA) were measured by qRT-PCR and western blot analysis. The cellular functions were assessed by using commercial kits, MTT assay, EdU assay, flow cytometry analysis, and transwell assay. The interactions between miR-520h and circNFATC3 or LDHA were confirmed by dual-luciferase reporter assay. Finally, the mice test was enforced to evaluate the character of circNFATC3. We observed that the contents of circNFATC3 and LDHA were upregulated and miR-520h levels were downregulated in OSCC tissues compared with those in paracancerous tissues. For functional analysis, circNFATC3 knockdown repressed the cell glycolysis metabolism, cell proliferation, migration, and invasion, although it improved cell apoptosis in OSCC cells. LDHA could regulate the development of OSCC. circNFATC3 acted as a miR-520h sponge to modulate LDHA expression. In addition, the absence of circNFATC3 subdued tumor growth in vivo. In conclusion, circNFATC3 promoted the advancement of OSCC by adjusting the miR-520h/LDHA axis.

CircRNA expression profiles in deltamethrin-susceptible and -resistant Culex pipiens pallens (Diptera: Culicidae)

The excessive and improper application of insecticides has caused the evolution of resistance in many mosquito populations, including Culex pipiens pallens (L.). Deltamethrin, a representative pyrethroid insecticide, is the most widely used synthetic insecticide in mosquito-borne control field. Comprehensively identifying genes and regulators associated with deltamethrin resistance and elucidating the manner in which they regulate this process is critical for effective control of mosquitoes. CircRNAs are the upstream regulatory factors of miRNAs and mRNAs, which play a role via the competitive endogenous RNA mechanism. In this study, we used high-throughput circRNA sequencing to identify circRNAs that were expressed differently in deltamethrin-susceptible strain (DS strain) and -resistant strain (DR strain) mosquitoes [NCBI Sequence Read Archive (SRA) database accession number: PRJNA714543]. We detected a total of 12,816 significantly differentially expressed circRNAs (DE-circRNAs). Among them, 6769 circRNAs were up-regulated and 6047 circRNAs were down-regulated in the DR strain compared to DS strain. Among the DE-circRNAs, we further screened that supercont3.352:252102|253283 was significantly over-expressed in the DR strain through qPCR multiple verification (P < 0.05).We used the divergent primer to amplify the rolling circle product and obtained the full-length sequence of supercont3.352:252102|253283 (GeneBank accession number: MW729338). Through software comparison and bioinformatics analysis, we predicted that supercont3.352:252102|253283 might participate in deltamethrin resistance by sponging cpp-miR-1671 and blocking its inhibition on CYP4G15.We further found that the expression of cpp-miR-1671 was significantly lower in DR strain (P < 0.01), while the expression of CYP4G15 was significantly higher in DR strain (P < 0.05).Taken together, the present study provided the most comprehensive circRNA expression profile of mosquitoes, and suggested that supercont3.352:252102|253283 might participate in deltamethrin resistance through the supercont3.352:252102|253283/cpp-miR-1671/CYP4G15 pathway.

circ3323 Motivates Host Gene to Promote the Aggressiveness of Bladder Cancer

Bladder cancer (BCa) is the most common cancer in the urinary system with high recurrence rate and poor prognosis. Circular RNA (circRNA) is a novel subclass of noncoding-RNA which participate in progression of BCa. Here, we identified a novel circRNA-circ3323 and aimed to investigate the role of circ3323 in progression of BCa. Public data of RNA sequencing was used to identify significant circRNA related to BCa. The role of circRNAs in progression of BCa was assessed in cytotoxicity assay, transwell assay and flow cytometry. Biotin-coupled RNA pull-down and fluorescence in situ hybridization were performed to evaluate the interaction between circRNAs and miRNAs. The expression of circ3323 was higher in BCa tissues and cells than in normal samples. Experiments in vitro showed that the knockdown of circ3323 inhibited cell proliferation and impeded the metastasis of BCa cells. Mechanistically, we demonstrated that circ3323 acts as a sponge for miR-186-5p and promotes host gene APP's expression. Clinically, circ3323 predicts worse overall survival of BCa patients, indicating its prognostic value. Our study identified that circ3323 modulates metastasis of BCa through miR-186-5p/APP axis and may serve as a promising prognostic biomarker for BCa, which provides novel insights into treatment of BCa.

Identification of key miRNAs and targeted genes involved in the progression of oral squamous cell carcinoma

Background/purpose

Oral squamous cell carcinoma (OSCC) is one of the most common types of head and neck squamous cell carcinoma. Accurate biomarkers are needed for early diagnosis and prognosis of OSCC. MicroRNAs (miRNAs) have shown great values in different types of cancers including OSCC. However, most of the miRNAs involved in the development of OSCC remain uncovered. This study aimed to identify hub miRNAs and mRNAs in OSCC.

Materials and methods

We explored the roles of key miRNAs, target genes and their relationships in OSCC using an integrated bioinformatics approach. Initially, Two OSCC microarray datasets from the Gene Expression Omnibus database were obtained to analyze miRNA expression. MiRNA-targeted mRNAs were acquired, and gene ontology/kyoto encyclopedia of genes and genomes analyses were performed. Thereafter, we constructed a protein–protein interaction (PPI) network to identify hub genes and a miRNA-mRNA interaction network was used to identify key miRNAs. Furthermore, differential gene expression and Kaplan–Meier Plotter survival analysis was performed to evaluate their potential clinical application values.

Results

Four upregulated, two downregulated miRNAs and 608 target genes of the differentially expressed miRNAs were identified. The PPI and miRNA-mRNA interaction networks highlighted 10 hub genes and two key miRNAs, and pathway analyses showed their correlative involvement in tumorigenesis-related processes. Of these miRNAs and genes, miR-125b, β-actin, vinculin and histone deacetylase 1 were correlated with overall survival (P < 0.05).

Conclusion

These findings indicate that miR-21 and miR-125b, associated with the 10 hub genes, jointly participate in OSCC tumorigenesis, offering insight into the molecular mechanisms underlying OSCC as potential targets for early diagnosis, treatment and prognosis.

CircLPAR3 Acts as an Oncogene in Oral Squamous Cell Carcinoma Through Regulating the miR-643/HMGB2 Network

The malignant progression of oral squamous cell carcinoma (OSCC) has been confirmed to be mediated by a variety of factors, including circular RNA (circRNA). However, the role of circLPAR3 in OSCC development is still unclear. 70 paired OSCC tissues and normal control tissues were obtained from 70 OSCC patients. Quantitative real-time PCR was used to detect the expression of circLPAR3, microRNA (miR)-643, and high-mobility group box 2 (HMGB2). Cell proliferation, apoptosis, metastasis and stemness were assessed using cell counting kit 8 assay, colony-formation assay, flow cytometry, transwell assay and sphere formation assay. Marker protein expression and HMGB2 protein expression were determined by western blot analysis. The interaction between miR-643 and circLPAR3 or HMGB2 was confirmed by RNA pull-down assay, dual-luciferase reporter and RIP assay. The role of circLPAR3 in OSCC tumorigenesis was explored by constructing the xenograft models. Our data showed that circLPAR3 was highly expressed in OSCC tissues and cells. CircLPAR3 silencing suppressed OSCC cell proliferation, metastasis and stemness, while promoted apoptosis. On the mechanism, we discovered that circLPAR3 could sponge miR-643 to positive regulate HMGB2. MiR-643 overexpression had an inhibition effect on OSCC progression, and its inhibitor could reverse the negative regulation of circLPAR3 knockdown on OSCC progression. In addition, overexpressed HMGB2 also reversed the suppressive effect of circLPAR3 silencing on OSCC progression. Animal experiments results showed that downregulated circLPAR3 repressed OSCC tumorigenesis in vivo. Taken together, our data showed that circLPAR3 contributed to OSCC malignant progression through regulating the miR-643/HMGB2 axis.

METTL3 Intensifies the Progress of Oral Squamous Cell Carcinoma via Modulating the m6A Amount of PRMT5 and PD-L1

N6-Methyladenosine (m6A) modification is one of the commonest chemical modifications in eukaryotic mRNAs, which has essential effects on mRNA translation, splicing, and stability. Currently, there is a rising concern on the regulatory role of m6A in tumorigenesis. As a known component in the m6A methyltransferase complex, METTL3 (methyltransferase-like 3) plays an essential role in m6A methylation. Till now, the functions of METTL3 in oral squamous cell carcinoma (OSCC) and its relative mechanism remain to be explored. In this research, through the GEPIA database, we found that high METTL3 expression has a correlation with poor prognosis of squamous cell carcinoma of head and neck. qRT-PCR displayed that METTL3 was highly expressed in OSCC cells. Functionally, METTL3 knockdown reduced the invasion, migration, and proliferation competence of OSCC cells and attenuated the activation of CD8+ T cells. In contrast, METTL3 overexpression resulted in opposite results. GEPIA, UALCAN, and SRAMP databases, PCR, western blot, and m6A RNA methylation assay confirmed the m6A modification of PRMT5 and PD-L1 mediated by METTL3. In conclusion, our results displayed that METTL3 intensified the metastasis and proliferation of OSCC by modulating the m6A amounts of PRMT5 and PD-L1, suggesting that METTL3 may be a therapeutic target for OSCC patients.

Hsa-circ-0007292 promotes the osteogenic differentiation of posterior longitudinal ligament cells via regulating SATB2 by sponging miR-508-3p

Ossification of the posterior longitudinal ligament (OPLL) is a disorder with multiple pathogenic mechanisms and leads to different degrees of neurological symptoms. Recent studies have revealed that non-coding RNA (ncRNA), including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), could influence the development of OPLL. Nevertheless, the molecular mechanisms linking circular RNAs (circRNAs) and the progression of OPLL is still unknown. The current research explored the expression profiles of OPLL-related circRNAs by microarray analysis, and applied qRT-PCR to validate the results. Subsequently, we confirmed the upregulation of hsa_circ_0007292 in OPLL cells by qRT-PCR and validated the circular characteristic of hsa_circ_0007292 by Sanger sequencing. Fluorescence in situ hybridization (FISH) unveiled that hsa_circ_0007292 was predominantly located in the cytoplasm. Functionally, gain-of-function and loss-of-function experiments showed that hsa_circ_0007292 promoted the osteogenic differentiation of OPLL cells. Mechanistically, the interaction of hsa_circ_0007292 and miR-508-3p was predicted and validated by bioinformatics analysis, dual-luciferase reporter assays, and Ago2 RNA immunoprecipitation (RIP). Similarly, we validated the correlation between miR-508-3p and SATB2. Furthermore, rescue experiments were performed to prove that hsa_circ_0007292 acted as a sponge for miR-508-3p, and SATB2 was revealed to be the target gene of miR-508-3p. In conclusion, our research shows that hsa_circ_0007292 regulates OPLL progression by the miR-508-3p/SATB2 pathway. Our results indicate that hsa_circ_0007292 can be used as a promising therapeutic target for patients with OPLL.

CircRNA HIPK3 promotes the progression of oral squamous cell carcinoma through upregulation of the NUPR1/PI3K/AKT pathway by sponging miR-637

Background

To investigate the expression, function, and related mechanisms of circHIPK3 in oral squamous cell carcinoma (OSCC).

Methods

CircHIPK3 expression was determined by quantitative reverse transcription polymerized chain reaction (QRT-PCR) in OSCC and adjacent tissues, and the correlation between the circHIPK3 level and clinicopathological indexes of OSCC was analyzed. CircHIPK3 expressions in different OSCC cell lines were detected, cell counting kit-8 (CCK-8) and 5-bromodeoxyuridine (BrdU) assays were utilized to monitor cell proliferation and activity. Flow cytometry was adopted to detect apoptosis and transwell assay was used to detect cell invasion. The expressions of nuclear protein 1 (NUPR1), phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) (PI3K/AKT) pathway proteins, and E-cadherin, Vimentin, and N-cadherin markers of epithelial-mesenchymal transformation (EMT) were detected by Western blot or Quantitative Real-time PCR (QRT-PCR).

Results

Upregulated circHIPK3 was noted in OSCC tissues (compared with adjacent tissues), and its overexpression was related to OSCC size and histopathological grade. Functionally, overexpressed circHIPK3 can significantly promote EMT, proliferation, and invasion of OSCC cells and can inhibit cell apoptosis in vivo and in vitro. In addition, CircHIPK3 upregulated the activation of NUPR1 and PI3K/AKT. Bioinformatics analyses showed that miR-637 was the common target of circHIPK3 and NUPR1, while a dual luciferase reporting assay and RIP assay further demonstrated that circHIPK3 targeted miR-637 and bound to 3' UTR of NUPR1.

Conclusions

CircHIPK3 demonstrates potential as a prognostic marker of OSCC and mediates OSCC progression via the miR-637-mediated NUPR1/PI3K/AKT axis.