Hsa_circ_0006692 Promotes Lung Cancer Progression via miR-205-5p/CDK19 Axis

Circular RNAs in Cell Cycle Regulation of Cancers

Cancer has been one of the most problematic health issues globally. Typically, all cancers share a common characteristic or cancer hallmark, such as sustaining cell proliferation, evading growth suppressors, and enabling replicative immortality. Indeed, cell cycle regulation in cancer is often found to be dysregulated, leading to an increase in aggressiveness. These dysregulations are partly due to the aberrant cellular signaling pathway. In recent years, circular RNAs (circRNAs) have been widely studied and classified as one of the regulators in various cancers. Numerous studies have reported that circRNAs antagonize or promote cancer progression through the modulation of cell cycle regulators or their associated signaling pathways, directly or indirectly. Mostly, circRNAs are known to act as microRNA (miRNA) sponges. However, they also hold additional mechanisms for regulating cellular activity, including protein binding, RNA-binding protein (RBP) recruitment, and protein translation. This review will discuss the current knowledge of how circRNAs regulate cell cycle-related proteins through the abovementioned mechanisms in different cancers.

Non-coding RNAs and exosomal non-coding RNAs in lung cancer: insights into their functions

Lung cancer is the second most common form of cancer worldwide Research points to the pivotal role of non-coding RNAs (ncRNAs) in controlling and managing the pathology by controlling essential pathways. ncRNAs have all been identified as being either up- or downregulated among individuals suffering from lung cancer thus hinting that they may play a role in either promoting or suppressing the spread of the disease. Several ncRNAs could be effective non-invasive biomarkers to diagnose or even serve as effective treatment options for those with lung cancer, and several molecules have emerged as potential targets of interest. Given that ncRNAs are contained in exosomes and are implicated in the development and progression of the malady. Herein, we have summarized the role of ncRNAs in lung cancer. Moreover, we highlight the role of exosomal ncRNAs in lung cancer.

Circ-10720 as a ceRNA adsorbs microRNA-1238 and modulates ZEB2 to boost NSCLC development by activating EMT

BACKGROUND

Circular RNAs (circRNAs) are critical regulators in the progression of tumors. This experimental design aimed to explore the mechanism of circ-10720 in non-small cell lung cancer (NSCLC).

METHODS

We used RT-qPCR to measure circ-10720 expression in clinical samples and analyzed its relationship with the clinicopathological characteristics of NSCLC patients. The expression levels of microRNA-1238 (miR-1238) and Zinc Finger E-box-binding Homeobox 2 (ZEB2) in clinical samples were detected by RT-qPCR. NSCLC cells were transfected with relevant plasmids or sequences. Circ-10720, miR-1238, and ZEB2 expressions in cells were analyzed via RT-qPCR or western blot. Cell proliferation, apoptosis, migration, and invasion were assessed with CCK-8, flow cytometry, and transwell assay, respectively. The protein expression of ZEB2 and epithelial-mesenchymal transition (EMT)-related markers (E-cadherin, Vimentin, N-cadherin) were detected via western blot. Xenograft assay was used to determine the effect of circ-10720 on NSCLC in vivo. Circ-10720 and ZEB2 expressions in tumors were detected using RT-qPCR or Western blot. Immunohistochemistry was used to evaluate E-cadherin and N-cadherin expression in tumors. Finally, the binding relationship between miR-1238 with circ-10720 or ZEB2 was verified by the bioinformatics website, dual luciferase reporter assay, RNA pull-down assay, and RIP assay.

RESULTS

Circ-10720 was upregulated in NSCLC and correlated with TNM stage of NSCLC patients. MiR-1238 was lowly expressed but ZEB2 was highly expressed in NSCLC. Circ-10720 silencing suppressed the proliferation, metastasis, and EMT of NSCLC cells. Mechanically, circ-10720 was a competitive endogenous RNA (ceRNA) for miR-1238, and ZEB2 was a target of miR-1238. circ-10720-modulated ZEB2 via competitively binding with miR-1238 to control NSCLC progression. In addition, circ-10720 knockdown suppressed tumor growth in vivo.

CONCLUSIONS

Circ-10720 acts as a ceRNA to adsorb miR-1238 and modulate ZEB2 to facilitate the proliferation, migration, invasion, and EMT of NSCLC cells.

Tumor-related exosomal circ_0001715 promotes lung adenocarcinoma cell proliferation and metastasis via enhancing M2 macrophage polarization by regulating triggering receptor expressed on myeloid cells-2

BACKGROUND

Circular RNAs (circRNAs) have been shown to mediate tumor-associated macrophages (TAMs) to regulate the development of many cancers, including lung adenocarcinoma (LUAD). However, whether circ_0001715 regulates LUAD progression by mediating TAMs polarization remains uncertain.

METHODS

Monocytes (THP-1) were treated with PMA to induce M0 macrophages. M0 macrophages were incubated with LUAD cells-derived exosomes and then cocultured with LUAD cells. The levels of circ_0001715, M2 macrophage markers, microRNA (miR)-205-5p, and triggering receptor expressed on myeloid cells-2 (TREM2) were examined using quantitative real-time PCR. Flow cytometry was performed to assess M2 macrophage surface marker CD206. Cell proliferation, migration and invasion were determined using cell counting kit 8, EdU, colony formation and transwell assays. Dual-luciferase reporter assay was used to investigate the interactions between miR-205-5p and circ_0001715 or TREM2.

RESULTS

Circ_0001715 knockdown inhibited M2 macrophage polarization and its overexpression had an opposite effect. After M0 macrophages transfected with si-circ_0001715 were cocultured with LUAD cells, the proliferation and metastasis of LUAD cells were markedly reduced. Exosomes transferred circ_0001715 between M0 macrophages and LUAD cells. Exosomal circ_0001715 promoted M2 macrophage polarization to increase LUAD cell proliferation and metastasis. In terms of mechanism, circ_0001715 sponged miR-205-5p to positively regulate TREM2. TREM2 upregulation also could promote LUAD cell proliferation and metastasis via increasing M2 macrophage polarization. In addition, TREM2 knockdown reversed the effect of exosomal circ_0001715 on M2 macrophage polarization and LUAD cell progression.

CONCLUSION

Exosomal circ_0001715 led to LUAD cell proliferation and metastasis by promoting M2 macrophage polarization via the miR-205-5p/TREM2 axis.

LncRNA LINC01703 promotes the proliferation, migration, and invasion of colorectal cancer by activating PI3K/AKT pathway

The role of LINC01703 in cancers, especially in colorectal cancer (CRC), is still largely unclear. Bioinformatics prediction, real-time quantitative polymerase chain reaction (RT-qPCR), 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, colony formation assay, Transwell assays, in vivo animal experiments, IF, luciferase reporter assay, and Western blot were carried out for the exploration of the potential involvement and underlying molecular mechanisms of LINC01703 in CRC cells. The results showed that LINC01703 appeared upregulated in CRC and was linked to poor prognosis. LINC01703 acted as an oncogene in both in vitro and in vivo CRC cell environments. LINC01703 activated the PI3K/AKT signaling pathway by mediating the miR-205-5p/E2F1 axis in CRC. In summary, LINC01703 possesses an oncogenic function and can be a possible biomarker or target to treat CRC.

Circular circRANGAP1 Contributes to Non-small Cell Lung Cancer Progression by Increasing COL11A1 Expression Through Sponging miR-653-5p

Numerous studies have discovered that hsa_circ_0063526 (also known as circRANGAP1) is an oncogenic circular RNA (circRNA) in some human tumors, including non-small cell lung cancer (NSCLC). However, the concrete molecular mechanism of circRANGAP1 involved in NSCLC is not completely elucidated. CircRANGAP1, microRNA-653-5p (miR-653-5p), and Type XI collagen (COL11A1) contents were determined via real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferative ability, migration, and invasion were measured using 5-ethynyl-2'-deoxyuridine (EdU), colony formation, wound healing, and transwell assays. E-cadherin, N-cadherin, Vimentin, and COL11A1 protein levels were detected via western blot assay. After Starbase software prediction, the binding between miR-653-5p and circRANGAP1 or COL11A1 was verified using a dual-luciferase reporter assay. Besides, the role of circRANGAP1 on tumor cell growth was analyzed using a xenograft tumor model in vivo. Increased circRANGAP1 and COL11A1, and reduced miR-653-5p were found in NSCLC tissues and cell lines. Furthermore, circRANGAP1 absence might hinder NSCLC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in vitro. Mechanically, circRANGAP1 functioned as a sponge of miR-653-5p to increase COL11A1 expression. In vivo experiments illustrated that circRANGAP1 knockdown repressed tumor growth. CircRANGAP1 silencing might suppress NSCLC cell malignant biological behaviors, at least in part, through the miR-653-5p/COL11A1 axis. These results provided a promising strategy for treating NSCLC malignancies.

CircRNAs and lung cancer: Insight into their roles in metastasis

Lung cancer is the leading cause of cancer-related mortality worldwide. A major contributing factor to the poor survival rates in lung cancer is the high prevalence of metastasis at the time of diagnosis. To address this critical issue, it is imperative to investigate the mechanisms underlying lung cancer metastasis. Circular RNAs (circRNAs), a distinct type of ribonucleic acid characterized by their unique circular structure, have been implicated in the progression of various diseases. Recent studies have highlighted the close association between circRNAs and the occurrence and development of lung cancer, particularly in relation to metastasis. In this review, we provide a concise overview of the expression patterns and prognostic significance of circRNAs in lung cancer. Additionally, we summarized the current understanding of the clinical relevance of circRNAs in lung cancer metastasis. Furthermore, we systematically focused on the roles of circRNAs in each step of lung cancer metastasis, reflecting the sequential progression of this process. Notably, circRNAs exhibit dual functionality in lung cancer metastasis, acting both as facilitators and inhibitors of metastatic processes. Given their potential, circRNAs hold promise as novel biomarkers and therapeutic targets for lung cancer metastasis, warranting further investigation.

LncRNA RP11-58O9.2 predicts poor prognosis and promotes progression of non-small cell lung cancer

OBJECTIVE

Long non-coding RNAs (lncRNAs) play a crucial role in non-small cell lung cancer (NSCLC). This study aimed to investigate the novel biomarker, lncRNA RP11-58O9.2, in patients with NSCLC.

METHODS

RP11-58O9.2 expression in NSCLC cells and tissues was detected by reverse transcription-quantitative polymerase chain reaction. Patient survival was analyzed in relation to RP11-58O9.2 expression levels. RP11-58O9.2 expression was knocked down and endogenous expression was verified in two NSCLC cell lines. Cell proliferation was then assessed by Cell Counting Kit-8 and colony-formation assays, and cell invasion and migration were assessed by Transwell and wound-healing assays, respectively. In vivo experiments were performed in mice, and the combination of RP11-58O9.2 and miR-6749-3p was predicted by miRanda.

RESULTS

RP11-58O9.2 was highly expressed in NSCLC cell lines and tissues, and was associated with advanced stage, lymphatic metastasis, and differentiation group. High RP11-58O9.2 levels were also associated with shorter survival. RP11-58O9.2 knockdown inhibited the proliferation, invasion, and migration of lung cancer cells, and tumor growth in mouse xenografts in vivo. RP11-58O9.2 may target and regulate miR-6749-3p.

CONCLUSIONS

LncRNA RP11-58O9.2 is associated with NSCLC prognosis and promotes lung cancer progression. Further studies are needed to investigate the mechanisms and the regulatory association between RP11-58O9.2 and miR-6749-3p.

The circHMGCS1-miR-205-5p-ErBB3 axis mediated the Sanggenon C-induced anti-proliferation effects on human prostate cancer

Prostate cancer (PCa) is associated with a high incidence and metastasis rate globally, resulting in an unsatisfactory prognosis and a huge economic burden due to the current deficient of therapeutic strategies. As the most abundant component of Cortex Mori, Sanggenon C (SC) is well known to possess bioactivities in tumors, but its mechanism is poorly understood. Consequently, we attempted to investigate whether SC could modulate circular RNA(s) levels and hence anti-PCa development. We found that SC dramatically promoted cell apoptosis and induced G0/G1 phase arrest in PCa cell lines via the circHMGCS1-miR-205-5p-ErBB3 axis. In brief, circHMGCS1 is highly expressed in PCa and is positively correlated with the degree of malignancy. Over-expression of circHMGCS1 is not only associated with the proliferation of PCa cells but also blocks SC-induced pro-apoptotic effects. As a verified sponge of circHMGCS1, miR-205-5p is down-regulated in PCa tumors, which negatively regulates PCa cell proliferation by modulating ErBB3 expression. After miR-205-5p mimics or inhibitors were used to transfect PCa cells, the effects of circHMGCS1 OE and SC on PCa cells were completely diminished. Similar to miR-205-5p inhibitors, siErBB3 could oppose SC-triggered pro-apoptotic effects on PCa cells. All these results were confirmed in vivo. Together, SC exerts its anti-tumor effects on PCa by inhibiting circHMGCS1 expression and results in the latter losing the ability to sponge miR-205-5p. Subsequently, unfettered miR-205-5p could mostly down-regulate ErBB3 expression by binding to the 5'UTR of ErBB3 mRNA, which eventually resulted in PCa cell cycle arrest and pro-apoptosis.