The hsa_circ_0000276-ceRNA regulatory network and immune infiltration in cervical cancer

Abstract

Background Our previous studies have confirmed that miR-154-5p can regulate pRb expression, and thus, play a tumor suppressor role in HPV16 E7-induced cervical cancer. However, its upstream molecules have not been elucidated in the progression of cervical cancer. This study aimed to explore the role of the miR-154-5p upstream molecule, hsa_circ_0000276 in cervical cancer development and its possible mechanisms of action. Methods We detected differences in whole transcriptome expression profiles of cervical squamous carcinoma and tissues adjacent to cervical cancer tissues from patients using microarray technology to predict circular RNAs (circRNAs) with binding sites to miR-154-5p. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression of hsa_circ_0000276 (which had the strongest binding capacity to miR-154 and was selected as the target molecule) in cervical cancer tissues, followed by in vitro functional assays. Downstream microRNAs (miRNAs) and mRNAs of hsa_circ_0000276 were identified using transcriptome microarray data and databases, while the protein–protein interaction networks were obtained using STRING. A competing endogenous RNA (ceRNA) network centered on hsa_circ_0000276 was constructed using Cytoscape and GO and KEGG databases. Abnormal expression and prognosis of critical downstream molecules were analyzed using gene databases and molecular experiments. qRT-PCR and western blot analysis was performed to verify the expression of candidate genes. Results We identified 4,001 differentially expressed circRNAs between HPV16-positive cervical squamous carcinoma and benign cervical tissues and 760 circRNAs targeting miR-154-5p, including hsa_circ_0000276. hsa_circ_0000276 and miR-154-5p directly bound, and hsa_circ_0000276 was upregulated, in cervical precancerous lesions and cervical cancer tissues and cells. Silencing hsa_circ_0000276 inhibited G1/S transition and cell proliferation and promoted apoptosis in SiHa and CaSki cells. Bioinformatics analysis showed that the hsa_circ_0000276 ceRNA network included 17 miRNAs and seven mRNAs, and downstream molecules of hsa_circ_0000276 were upregulated in cervical cancer tissues. These downstream molecules were associated with a poor prognosis and affected cervical cancer-associated immune infiltration. Of these, expression of CD47, LDHA, PDIA3, and SLC16A1 was downregulated in sh_hsa_circ_0000276 cells. Conclusions Our findings show that hsa_circ_0000276 exerts cancer-promoting effects in cervical cancer and is an underlying biomarker for cervical squamous cell carcinoma.

Hijacking and rewiring of host CircRNA/miRNA/mRNA competitive endogenous RNA (ceRNA) regulatory networks by oncoviruses during development of viral cancers

“…Based on these findings, circ_0000276 may contribute to cervical cancer development and progression by modulating immune infiltration. 86…”

“…The results showed that knockdown of the circ_0000276 resulted in significant inhibitions in cell proliferation. 86 Furthermore, it was found that silencing of circ_0000276 resulted in a higher number of malignant cells being arrested in the G1 phase of the cell cycle, whereas there was a decrease in malignant cells in the S phase. 86 Similarly, the suppression of circ_0000276 resulted in a notable rise in the apoptosis rate of cells, suggesting that circ_0000276 within F I G U R E 2 A schematic representation of ceRNAs that compete for shared miRNAs post-transcriptionally.…”

“…86 Furthermore, it was found that silencing of circ_0000276 resulted in a higher number of malignant cells being arrested in the G1 phase of the cell cycle, whereas there was a decrease in malignant cells in the S phase. 86 Similarly, the suppression of circ_0000276 resulted in a notable rise in the apoptosis rate of cells, suggesting that circ_0000276 within F I G U R E 2 A schematic representation of ceRNAs that compete for shared miRNAs post-transcriptionally. ncRNAs such as miRNA, lncRNA, pseudogenic RNA, and circRNA are linked to protein-coding mRNAs via ceRNA networks.…”

“…It is known that circ_0000276 possesses a binding site for miRNA-154-5p, capable of suppressing tumour growth when expressed in normal cells. [86][87][88][89] The hsa_circ_0000276 ceRNA network contained 17 miRNAs and four mRNAs, including CD47, LDHA, PDIA3, and SCL16A1. There is an increased expression of downstream molecules associated with circ_0000276, along with immune infiltration in cervical cancer tissues.…”

“…ShRNA targeting the circ_0000276 was utilised to suppress its expression in vitro. The results showed that knockdown of the circ_0000276 resulted in significant inhibitions in cell proliferation 86 . Furthermore, it was found that silencing of circ_0000276 resulted in a higher number of malignant cells being arrested in the G1 phase of the cell cycle, whereas there was a decrease in malignant cells in the S phase 86 .…”