Hsa_circ_0008234 facilitates proliferation of cutaneous squamous cell carcinoma through targeting miR-127-5p to regulate ADCY7

CircRNA RNA hsa_circ_0008234 Promotes Colon Cancer Progression by Regulating the miR-338-3p/ETS1 Axis and PI3K/AKT/mTOR Signaling

Circular RNAs (circRNAs) have been shown to play a crucial role in cancer occurrence and progression. This present work investigated the link between hsa_circ_0008234 and colon cancer. Data retrieved from GSE172229 was used to compare the circRNA profiles of colon cancer and surrounding non-tumorous tissues. The amount of RNA and protein in the molecules was determined using quantitative real-time PCR (qRT-PCR) and Western blot analysis, respectively. The cell proliferation ability was assessed using CCK8, EdU, colon formation, and nude mice tumorigenesis tests. Cell invasion and migration abilities were evaluated using transwell wound healing and mice lung metastasis model. Hsa_circ_0008234 piqued our interest because bioinformatics and qRT-PCR analyses revealed that it is upregulated in colon cancer tissue. Cell phenotypic studies suggest that hsa_circ_0008234 may significantly increase colon cancer cell aggressiveness. Mice experiments revealed that inhibiting hsa_circ_0008234 significantly reduced tumor growth and metastasis. Moreover, the fluorescence in situ hybridization experiment demonstrated that hsa_circ_0008234 is primarily found in the cytoplasm, implying that it potentially functions via a competitive endogenous RNA pathway. These findings indicated that hsa_circ_0008234 may act as a “molecular sponge” for miR-338-3p, increasing the expression of miR-338-target 3p’s ETS1. In addition, the traditional oncogenic pathway PI3K/AKT/mTOR signaling was found to be the potential downstream pathway of the hsa_circ_0008234/miR-338-3p/ETS1 axis. In conclusion, hsa_circ_0008234 increases colon cancer proliferation, infiltration, and migration via the miR-338-3p/ETS1/PI3K/AKT axis; therefore, it could serve as a target and a focus for colon cancer therapy.

Circ_0068631 sponges miR-139-5p to promote the growth and metastasis of cutaneous squamous cell carcinoma by upregulating HOXB7

BACKGROUND

Circular RNAs (circRNAs) are often dysregulated in cancers and closely related to cancer progression, including cutaneous squamous cell carcinoma (CSCC). However, the role and mechanism of circ_0068631 in CSCC progression have not been reported.

METHODS

The expression of circ_0068631, microRNA-139-5p (miR-139-5p), and homeobox B7 (HOXB7) was measured by real-time quantitative polymerase chain reaction (RT-qPCR). Cell counting kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, and colony formation assay were used to measure cell proliferation. Cell apoptosis was assessed by flow cytometry. Cell migration was detected by transwell assay. The interaction between miR-139-5p and circ_0068631 or HOXB7 was confirmed by dual-luciferase reporter assay. A xenograft tumor model was established to confirm the function of circ_0068631 in vivo.

RESULTS

Circ_0068631 was upregulated in CSCC tissues and cells, and its silencing could inhibit CSCC cell proliferation and metastasis while promoting apoptosis in vitro, as well as restrain CSCC tumor growth in vivo. Circ_0068631 acted as a sponge of miR-139-5p, and miR-139-5p inhibition reversed the repressive effect of circ_0068631 knockdown on CSCC cell progression. Furthermore, HOXB7 was a target of miR-139-5p, and miR-139-5p inhibited the malignant behaviors by downregulating HOXB7 expression in CSCC cells. Further, circ_0068631 sponged miR-139-5p to regulate HOXB7 expression.

CONCLUSION

Circ_0068631 functioned as a novel oncogene in CSCC progression by regulating miR-139-5p/HOXB7 axis, suggesting that circ_0068631 may be a potential target for CSCC treatment.

HIGHLIGHTS

Circ_0068631 was overexpressed in CSCC tissues and cells. Circ_0068631 downregulation suppressed CSCC progression via miR-139-5p. Circ_0068631 regulated HOXB7 via sponging miR-139-5p.

Circ_0001402 knockdown suppresses the chemoresistance and development of DDP-resistant cutaneous squamous cell carcinoma cells by functioning as a ceRNA for miR-625-5p

Cutaneous squamous cell carcinoma (CSCC) is the most common metastatic skin cancer. Circular RNAs (circRNAs) are differentially expressed in CSCC and can sequester and sponge microRNAs. GSE74758 shows that hsa_circ_0001402 (circ_0001402) is the most overexpressed circRNA in CSCC. Expression of circ_0001402, microRNA(miR)-625-5p and karyopherin subunit alpha 4 (KPNA4) was detected by quantitative real-time polymerase chain reaction and/or Western blot. Colon formation, flow cytometry, Transwell assays and xenograft tumour model confirmed the development of CSCC cells. The competing endogenous RNA (ceRNA) interaction was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Circ_0001402 was significantly upregulated in CSCC tissues and cells, and higher expression of circ_0001402 was found in DDP-resistant samples. Functionally, circ_0001402 knockdown induced apoptosis and inhibited half maximal inhibitory concentration of DDP, colony formation, migration and invasion of DDP-resistant CSCC cells, accompanied with the depressed multi-drug resistance-1 (MDR1) and MDR-related protein-1, while miR-625-5p inhibitor could counteract these effects. Mechanically, circ_0001402 mediated the expression regulation of KPNA4 via functioning as a ceRNA for miR-625-5p. KPNA4 re-expression could abate the functions of miR-625-5p. Furthermore, circ_0001402 knockdown could hinder tumour growth of DDP-resistant CSCC. Circ_0001402 knockdown can suppress the development and chemoresistance of DDP-resistant CSCC cells at least partly through targeting miR-625-5p/KPNA4 axis.

Non-coding RNAs in skin cancers:Biological roles and molecular mechanisms

Cutaneous malignancies, including basal cell carcinoma, cutaneous squamous cell carcinoma, and cutaneous melanoma, are common human tumors. The incidence of cutaneous malignancies is increasing worldwide, and the leading cause of death is malignant invasion and metastasis. The molecular biology of oncogenes has drawn researchers’ attention because of the potential for targeted therapies. Noncoding RNAs, including microRNAs, long noncoding RNAs, and circular RNAs, have been studied extensively in recent years. This review summarizes the aspects of noncoding RNAs related to the metastasis mechanism of skin malignancies. Continuous research may facilitate the identification of new therapeutic targets and help elucidate the mechanism of tumor metastasis, thus providing new opportunities to improve the survival rate of patients with skin malignancies.

miR-127-5p Targets JAM3 to Regulate Ferroptosis, Proliferation, and Metastasis in Malignant Meningioma Cells

Objective

Meningiomas are one of the most common primary tumors of the central nervous system. Most of them are benign and can be cured by surgery, while a few meningiomas are malignant. Ferroptosis gene characteristics might be associated with drug therapy and survival in patients with clinically aggressive, unresectable meningiomas. This study explored the mechanism of differentially expressed miRNAs and ferroptosis in meningioma to provide a new reference to treat meningioma.

Methods

Bioinformatics analysis of differential miRNA profiles and functions in patients with meningioma was performed. The contents of lactate dehydrogenase (LDH), malondialdehyde (MDA), and Fe²⁺ were determined. Reactive oxygen species (ROS) values, as well as cell cycle changes, were analyzed by flow cytometry. The targets of miR-127-5p and JAM3 were detected by dual luciferase assays. Cell counting kit-8 (CCK8) and Transwell assays were used to analyze cell activity. Ki67 expression was analyzed by immunohistochemistry. Expression levels of miR-127-5p and JAM3 were analyzed by RT-qPCR. GPX4 expression was quantified by western blotting.

Results

miR-127-5p was expressed at low levels in IOMM-Lee cells, while JAM3 was highly expressed in IOMM-Lee cells. A dual luciferase assay demonstrated that miR-127-5p could target JAM3. Upregulation of miR-127-5p in IOMM-Lee cells resulted in cell cycle arrest and inhibition of cell activity. Upregulation of miR-127-5p increased LDH, MDA, and ROS levels and Fe²⁺ content and inhibited the expression of GPX4 protein. Upregulation of JAM3 reversed the results of miR-127-5p upregulation.

Conclusion

miR-127-5p regulated meningioma formation and ferroptosis through JAM3, providing insights for the development of new treatments for meningioma.

Construction of circRNA-miRNA-mRNA network and identification of novel potential biomarkers for non-small cell lung cancer

Background

The underlying circular RNAs (circRNAs)-related competitive endogenous RNA (ceRNA) mechanisms of pathogenesis and prognosis in non-small cell lung cancer (NSCLC) remain unclear.

Methods

Differentially expressed circRNAs (DECs) in two Gene Expression Omnibus datasets (GSE101684 and GSE112214) were identified by utilizing R package (Limma). Circinteractome and StarBase databases were used to predict circRNA associated-miRNAs and mRNAs, respectively. Then, protein–protein interaction (PPI) network of hub genes and ceRNA network were constructed by STRING and Cytoscape. Also, analyses of functional enrichment, genomic mutation and diagnostic ROC were performed. TIMER database was used to analyze the association between immune infiltration and target genes. Kaplan–Meier analysis, cox regression and the nomogram prediction model were used to evaluate the prognostic value of target genes. Finally, the expression of potential circRNAs and target genes was validated in cell lines and tissues by quantitative real-time PCR (qRT-PCR) and Human Protein Atlas (HPA) database.

Results

In this study, 15 DECs were identified between NSCLC tissues and adjacent-normal tissues in two GEO datasets. Following the qRT-PCR corroboration, 7 DECs (hsa_circ_0002017, hsa_circ_0069244, hsa_circ_026337, hsa_circ_0002346, hsa_circ_0007386, hsa_circ_0008234, hsa_circ_0006857) were dramatically downregulated in A549 and SK-MES-1 compared with HFL-1 cells. Then, 12 circRNA-sponged miRNAs were screened by Circinteractome and StarBase, especially, hsa-miR-767-3p and hsa-miR-767-5p were significantly up-regulated and relevant to the prognosis. Utilizing the miRDB and Cytoscape, 12 miRNA-target genes were found. Functional enrichment, genomic mutation and diagnostic analyses were also performed. Among them, FNBP1, AKT3, HERC1, COL4A1, TOLLIP, ARRB1, FZD4 and PIK3R1 were related to the immune infiltration via TIMER database. The expression of ARRB1, FNBP1, FZD4, and HERC1 was correlated with poor overall survival (OS) in NSCLC patients by cox regression and nomogram. Furthermore, the hub-mRNAs were validated in cell lines and tissues.

Conclusion

We constructed the circRNA-miRNA-mRNA network that might provide novel insights into the pathogenesis of NSCLC and reveal promising immune infiltration and prognostic biomarkers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02278-z.

The Role of Circular RNAs in Keratinocyte Carcinomas

Keratinocyte carcinomas (KC) include basal cell carcinomas (BCC) and cutaneous squamous cell carcinomas (cSCC) and represents the most common cancer in Europe and North America. Both entities are characterized by a very high mutational burden, mainly UV signature mutations. Predominately mutated genes in BCC belong to the sonic hedgehog pathway, whereas, in cSCC, TP53, CDKN2A, NOTCH1/2 and others are most frequently mutated. In addition, the dysregulation of factors associated with epithelial to mesenchymal transition (EMT) was shown in invasive cSCC. The expression of factors associated with tumorigenesis can be controlled in several ways and include non-coding RNA molecules, such as micro RNAs (miRNA) long noncoding RNAs (lncRNA) and circular RNAs (circRNA). To update findings on circRNA in KC, we reviewed 13 papers published since 2016, identified in a PubMed search. In both BCC and cSCC, numerous circRNAs were identified that were differently expressed compared to healthy skin. Some of them were shown to target miRNAs that are also dysregulated in KC. Moreover, some studies confirmed the biological functions of individual circRNAs involved in cancer development. Thus, circRNAs may be used as biomarkers of disease and disease progression and represent potential targets of new therapeutic approaches for KC.