hsa_circ_0072309 Expression Profiling in Non-small-Cell Lung Carcinoma and Its Implications for Diagnosis and Prognosis

Hsa_circ_0072088 promotes non-small cell lung cancer progression through modulating miR-1270/TOP2A axis

According to the data released by the International Agency for Research on Cancer (IARC) in 2020, lung cancer ranks second among newly diagnosed malignant tumors globally. As a special class of non-coding RNA, circRNA has become a new hotspot in the field of biomarker research. With the continuous deepening of molecular-level investigations, the underlying mechanisms of circRNA are being gradually unveiled. The more widely studied mechanism is the competitive endogenous RNA mechanism of circRNA. Studies related to circRNA expression were searched in GEO database and statistically analyzed using the "limma" package and weighted gene co-expression network analysis. The expression of circRNA, microRNA and mRNA in cells and tissues were examined via qRT-PCR. MTS assay was used to measure cell proliferation, Transwell assay was used to measure cell migration, and apoptosis assay was carried out to detect cell apoptosis. Additionally, a dual-luciferase reporter assay was further executed to explore the targeted binding relationships between circRNA-microRNA and microRNA-mRNA. It was discovered that hsa_circRNA_103809 was differentially highly expressed in non-small cell lung cancer cells, whereas miR-1270 was differentially lowly expressed. The knockdown of circ_0072088 inhibited the cell proliferation and migration, while promoting cell apoptosis. The same biological function was found with the overexpression of miR-1270. The rescue experiment further validated that circ_0072088 could regulate the biological function of cells by influencing miR-1270. Finally, the targeted binding relationship was verified by dual luciferase reporting experiment. In conclusion, circ_0072088 is differentially highly expressed in non-small cell lung cancer and can affect the progression of non-small cell lung cancer through the circ_0072088/miR-1270/TOP2A axis.

The role of circular RNAs (circRNAs) as a prognostic factor in lung cancer: a meta-analysis

BACKGROUND

Lung cancer is a leading cause of cancer-related death worldwide. Among various histological types of lung cancer, majority are non-small cell lung cancer (NSCLC) which account for > 80%. Circular RNAs (circRNAs) are widely expressed in various cancers including lung cancer and implicated in tumourigenesis and cancer progression. This study aimed to systematically evaluate the prognostic values of circRNAs in lung cancer.

METHODS

A systematic literature search was done in PubMed, Embase, and MEDLINE databases to select the eligible studies which reported the association between the expression of circRNAs and overall survival (OS) or disease-free survival (DFS) in histopathologically diagnosed lung cancer patients. The pooled hazard ratio (HR) and 95% confidence interval (CI) were assessed to determine the prognostic significance of circRNAs.

RESULTS

A total of 43 studies were eligible for this meta-analysis (MA). 39 different types of circRNAs were reported: 28 showing upregulating and 11 showing downregulating action in lung cancer. High expression of circRNAs with upregulating action in lung cancer was associated with worse prognosis and poor OS (HR 1.93, 95% CI [1.61-2.33], p < 0.00001). High expression of circRNAs with downregulating action in lung cancer was associated with favorable OS and prognosis (HR 0.73, 95% CI [0.58-0.94], p = 0.01). However, there was no statistically significant association between high and low expression of both upregulating and downregulating circRNAs and DFS (HR 1.44, 95% CI [0.92-2.24], p = 0.11).

CONCLUSIONS

This MA confirmed the pivotal role of circRNAs as important prognostic biomarkers for lung cancer, especially NSCLC. High expression of upregulating circRNAs is associated with poor prognosis; however, high expression of downregulating circRNAs is associated with favorable prognosis. Therefore, downregulatory action of circRNAs should be considered a promising treatment in the management of lung cancer, especially NSCLC.

IGF2BP3 loss inhibits cell progression by upregulating has_circRNA_103820, and hsa_circRNA_103820-encoded peptide inhibits cell progression by inactivating the AKT pathway in lung cancer

N6-methyladenosine (m6A) modification and m6A-related RNA-binding proteins (RBPs) play vital roles in various aspects of circRNA metabolism. Hsa_circRNA_103820 is implicated in the pathogenesis of multiple cancers, including lung cancer (LC). Moreover, bioinformatics analysis has suggested that hsa_circRNA_103820 possesses potential peptide-coding ability. Thus, we aimed to investigate the function and peptide-coding potential of hsa_circRNA_103820 in this study. Cell viability, apoptosis rate, and migratory and invasive abilities were assessed using CCK-8, flow cytometry, and transwell assays, respectively. Hsa_circRNA_103820 level was measured using RT-qPCR assay, and the interaction between hsa_circRNA_103820 and IGF2BP3 was examined through RIP and RT-qPCR assays. The coding ability of hsa_circRNA_103820 and protein levels were determined through western blot assay. The results showed that hsa_circRNA_103820 reduced cell viability, attenuated cell migratory and invasive abilities, and promoted cell apoptosis in LC. IGF2BP3 negatively regulated hsa_circRNA_103820 expression and interacted with it. Hsa_circRNA_103820 knockdown alleviated si-IGF2BP3-mediated anti-viability, anti-migration, anti-invasion, and pro-apoptosis effects in LC cells. Moreover, a 188-amino acid (aa) peptide encoded by hsa_circRNA_103820 decreased cell viability, facilitated cell apoptosis, and inhibited cell migration and invasion in LC. Collectively, hsa_circRNA_103820, regulated by IGF2BP3, encodes a 188-aa peptide and inhibits the malignant progression of LC cells by inhibiting the AKT pathway.

The diagnostic significance of blood-derived circRNAs in NSCLC: Systematic review and meta-analysis

Background

Using blood-derived circular RNAs (circRNAs) may be an efficient tool for noninvasive fluid biopsy in diagnosing non-small cell lung cancer (NSCLC). However, no relevant systemic meta-analysis has been conducted so far to support the diagnostic value of using blood-derived circRNAs in NSCLC clinically. The aim of this study is to clarify the issue through a meta-analysis.

Methods

A systematic search strategy was used to search relevant literature in the databases of PubMed, Web of Science, and Cochrane Library from 2017 to 2022. The relationship between the diagnostic accuracy of circRNAs and NSCLC was analyzed. For the purpose of evaluating the quality of the literature, Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used. Statistical analyses were assessed using Stata software (version 17.0) and META-DISC (version 1.4).

Results

The meta-analysis included 1,093 patients with NSCLC and 959 controls. Results are as follows: pooled sensitivity, 0.78 (95% CI = 0.71–0.83, I² = 71.86); pooled specificity, 0.76 (95% CI = 0.70–0.82, I² = 70.12); pooled positive likelihood ratio (PLR), 3.3 (95% CI = 2.6–4.2, I² = 37.56); pooled negative likelihood ratio (NLR), 0.29 (95% CI = 0.23–0.37, I² = 64.67); diagnostic odds ratio (DOR), 11.42 (95% CI = 7.88–16.56, I² = 99.05); area under the receiver operating characteristic curve (AUC), 0.84 (95% CI = 0.80–0.87). Based on the subgroup analysis, it appears that the heterogeneity is primarily caused by the NSCLC subgroup.

Conclusion

circRNAs are highly useful diagnostic biomarkers for NSCLC in China. Further prospective studies on the diagnostic value of circRNAs should be conducted in multiple countries.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022323804.