CircRNA circ_0006677 Inhibits the Progression and Glycolysis in Non-Small-Cell Lung Cancer by Sponging miR-578 and Regulating SOCS2 Expression

Long non-coding RNAs in cancer: multifaceted roles and potential targets for immunotherapy

Cancer remains a major global health concern with high mortality rates mainly due to late diagnosis and poor prognosis. Long non-coding RNAs (lncRNAs) are emerging as key regulators of gene expression in human cancer, functioning through various mechanisms including as competing endogenous RNAs (ceRNAs) and indirectly regulating miRNA expression. LncRNAs have been found to have both oncogenic and tumor-suppressive roles in cancer, with the former promoting cancer cell proliferation, migration, invasion, and poor prognosis. Recent research has shown that lncRNAs are expressed in various immune cells and are involved in cancer cell immune escape and the modulation of the tumor microenvironment, thus highlighting their potential as targets for cancer immunotherapy. Targeting lncRNAs in cancer or immune cells could enhance the anti-tumor immune response and improve cancer immunotherapy outcomes. However, further research is required to fully understand the functional roles of lncRNAs in cancer and the immune system and their potential as targets for cancer immunotherapy. This review offers a comprehensive examination of the multifaceted roles of lncRNAs in human cancers, with a focus on their potential as targets for cancer immunotherapy. By exploring the intricate mechanisms underlying lncRNA-mediated regulation of cancer cell proliferation, invasion, and immune evasion, we provide insights into the diverse therapeutic applications of these molecules.

CircGPC3 promotes hepatocellular carcinoma progression and metastasis by sponging miR-578 and regulating RAB7A/PSME3 expression

CircRNAs are a class of highly stable noncoding RNAs that play an important role in the progression of many diseases, especially cancer. In this study, high-throughput sequencing was used to screen for abnormally expressed circRNAs, and we found that circGPC3 was overexpressed in HCC tissues. However, the underlying mechanism of circGPC3 in the development and metastasis of hepatocellular carcinoma (HCC) remains unknown. In our study, we found that circGPC3 was significantly upregulated in HCC tissues and cells and that its overexpression was positively correlated with overall survival, TNM stage and lymph node metastasis. In vivo and in vitro experiments showed that circGPC3 knockdown repressed HCC cell migration, invasion and proliferation and promoted apoptosis. Mechanistically, circGPC3 promoted HCC proliferation and metastasis through the miR-578/RAB7A/PSME3 axis. Our results demonstrate that circGPC3 contributes to the progression of HCC and provides an intervention target for HCC.

Inhibition of miR-578 through SOCS2-dependent manner reverses gefitinib resistance in NSCLC cells

BACKGROUND

Nonsmall-cell lung cancer (NSCLC) has emerged as one of the dreadful lung cancers globally due to its increased mortality rates. Concerning chemotherapy, gefitinib has been employed as an effective first-line treatment drug for NSCLC. Nonetheless, the acquired resistance to gefitinib has remained one of the treatment obstacles of NSCLC, requiring improvement in the therapeutic effect of gefitinib.

METHODS

Initially, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and Western blotting (WB) analyses were conducted to measure micro-ribose nucleic acid (miRNA, specifically miR-578) and suppressor of cytokine signaling 2 (SOCS2) levels in the clinical samples. Further, NSCLC cell lines resistance to gefitinib, established in vitro, were transfected by miR-578 inhibitor, miR-578 mimic, and si-SOCS2. Similarly, the xenograft mouse model in vivo was constructed to validate the reversing effect of miR-578.

RESULTS

Our findings indicated the increased miR-578 expression levels in the gefitinib resistance group. Further, inhibiting the miR-578 expression substantially reversed the gefitinib resistance. In addition, the miR-578 effect was modulated via the SOCS2 expression level. The decreased gefitinib resistance effect of miR-578 was weakened by inhibiting the SOCS2 expression.

CONCLUSION

These findings demonstrated that miR-578 effectively abolished gefitinib resistance by regulating the SOCS2 expression within NSCLC cells in vitro and in vivo. Together, these results will undoubtedly support a reference to provide potential molecular therapeutic targets and clinical treatments for treating NSCLC patients.

Circular RNA P4HB promotes glycolysis and tumor progression by binding with PKM2 in lung adenocarcinoma

BACKGROUND

Emerging evidence indicates that circular RNAs (circRNAs) play vital roles in tumor progression, including lung adenocarcinomas (LUAD). However, the mechanisms by which circRNAs promote the progression of LUAD still require further investigation.

METHODS

Quantitative real-time PCR was performed to detect the expression of circP4HB in LUAD tissues and cells. Then, Kaplan-Meier analysis was used to determine the prognostic value of circP4HB expression. We employed RNA pull-down, RNA immunoprecipitation, mass spectrometry, cells fraction, glucose consumption, lactate production, pyruvate kinase M2 (PKM2) activity, and macrophage polarization assays to uncover the underlying mechanisms of circP4HB in LUAD.

RESULTS

We found that circP4HB is upregulated in LUAD tissues and correlated with advanced TNM stages and lymph node metastasis. LUAD patients with high circP4HB expression had poor prognoses. Functionally, circP4HB promoted LUAD progression in vivo and in vitro. Upregulated circP4HB increased glucose consumption, lactate production and accelerated aerobic glycolysis in LUAD cells. Mechanically, circP4HB mainly accumulated in the cytoplasm of LUAD cells and bound with PKM2 and subsequently upregulating PKM2 enzymatic activity by increasing its tetramer formation. Additionally, circP4HB promoted M2 macrophage phenotype shift via targeting PKM2. Finally, rescue assays further confirmed that circP4HB could promote LUAD cell progression through its interaction with PKM2.

CONCLUSION

These results demonstrate that circP4HB could promote LUAD progression, indicating circP4HB might be a potential therapeutic target of LUAD.

Sevoflurane suppresses the malignant progression of breast cancer via the hsa_circ_0000129/miR-578/EPSTI1 axis

BACKGROUND

Sevoflurane (Sev) is a commonly used volatile anesthetic that might suppress the process of breast cancer. Also, circular RNAs (circRNAs) have been reported to partake in the pathogenesis of breast cancer. Accordingly, this research was designed to investigate the mechanism of hsa_circ_0005962 on Sev-mediated breast cancer development.

METHODS

Sev was applied to treat breast cancer cells. Cell proliferation ability, migration, invasion, and apoptosis were detected using Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), Transwell, and flow cytometry assay. Proliferating cell nuclear antigen (PCNA), Matrix metallopeptidase 9 (MMP9), B-cell lymphoma-2 (Bcl-2)-associated X protein (Bax), and Epithelial stromal interaction 1 (EPSTI1) were assessed using western blot assay. circ_0000129, microRNA-578 (miR-578), and EPSTI1 levels were determined using real-time quantitative polymerase chain reaction (RT-qPCR). Using bioinformatics software (Circinteractome and Targetscan), the binding between miR-578 and circ_0000129 or EPSTI1 were predicted, and proved using dual-luciferase reporter and RNA pull-down assay. The biological roles of circ_0000129 and Sevoflurane on tumor growth were analyzed using a xenograft tumor model in vivo.

RESULTS

Sevoflurane blocked tumor cell proliferation, migration, invasion, and promoted apoptosis. Circ_0000129 and EPSTI1 expression were increased, and miR-578 was decreased in breast cancer cells. Also, they presented an opposite trend in Sev-treated tumor cells. Circ_0000129 upregulation might abolish Sev-mediated tumor progression in vitro. Mechanically, circ_0000129 can affect EPSTI1 expression by sponging miR-578. Sev might inhibit tumor growth by regulating circ_0000129 in vivo.

CONCLUSION

Circ_0000129 relieved Sev-triggered suppression impacts on breast cancer development partly via the miR-578/EPSTI1 axis, which provides a new mechanism for studying mediated therapy of breast cancer treatment.

Has_circ_0048764 promotes breast cancer progression by sponging miR-578 and regulating HMGA2 expression

BACKGROUND

Circular RNAs (circRNAs) function as important regulators in the progression of cancers. The role of circRNA_0048764 (circ_0048764) in the development of breast cancer (BC) remains inconclusive. This work investigates the biological function and molecular mechanism of circ_0048764 in BC.

METHODS

Quantitative real-time PCR (qRT-PCR) was conducted to measure the expression levels of circ_0048764, microRNA-578 (miR-578) and high mobility group AT-hook 2 (HMGA2) mRNA. The viability of BC cells was examined by cell counting kit 8 (CCK-8) assay. Besides, cyclin D1, proliferating cell nuclear antigen (PCNA) and HMGA2 expression levels were detected by western blot. The migrative and invasive capability of BC cells were probed by transwell assay. The relationships between miR-578 and circ_0048764 or HMGA2 3'-UTR were validated by dual-luciferase reporter gene assay.

RESULTS

Circ_0048764 was highly expressed in BC tissues and cells, which was significantly associated with tumor size (≥2 cm), lymph node status (positive), and higher TNM stage of BC patients. Circ_0048764 depletion suppressed the proliferative, migrative, and invasive abilities of BC cells, which was rescued by transfection of miR-578 inhibitors. The binding sites were verified between circ_0048764 and miR-578. HMGA2 was identified to be a target of miR-578 in BC cells, and circ_0048764 positively regulated HMGA2 expression in BC cells via repressing miR-578.

CONCLUSION

Circ_0048764 promotes BC cell growth, migration and invasion via absorbing miR-578 and up-regulating HMGA2.

Exosomal circular RNA: a signature for lung cancer progression

Membrane vesicles having a diameter of 30-150 nm are known as exosomes. Several cancer types secrete exosomes, which may contain proteins, circular RNAs (circRNAs), microRNAs, or DNA. CircRNAs are endogenous RNAs that do not code for proteins and can create continuous and covalently closed loops. In cancer pathogenesis, especially metastasis, exosomal circRNAs (exo-circRNAs) have a crucial role mainly due to the frequently aberrant expression levels within tumors. However, neither the activities nor the regulatory mechanisms of exo-circRNAs in advancing lung cancer (LC) are obvious. A better understanding of the regulation and network connections of exo-circRNAs will lead to better treatment for LCs. The main objective of the current review is to highlight the functions and mechanisms of exo-circRNAs in LC and assess the relationships between exo-circRNA dysregulation and LC progression. In addition, underline the possible therapeutic targets based on exo-circRNA modulating.

Circular RNA hsa_circ_0018189 drives non-small cell lung cancer growth by sequestering miR-656-3p and enhancing xCT expression

BACKGROUND

Non-small cell lung cancer (NSCLC) is one of the cancers with a high mortality rate. CircRNAs have emerged as an important regulatory factor in tumorigenesis in recent years. However, the detailed regulatory mechanism of a circular RNA cullin 2 (hsa_circ_0018189; hsa_circ_0018189) is still unclear in NSCLC.

METHODS

RNA levels of hsa_circ_0018189, microRNA (miR)-656-3p, and Solute carrier family seven member 11 (SLC7A11, xCT) were analyzed by real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR), and protein level was assessed by Western blot and immunohistochemical assay. Enzyme-linked immunosorbent assay was conducted to detect cell glutamine metabolism. Effects of hsa_circ_0018189 on cell proliferation, apoptosis, migration, and invasion were analyzed by corresponding assays. Luciferase reporter assay and RNA-immunoprecipitation assay confirmed the target relationship between miR-656-3p and hsa_circ_0018189 or xCT. The in vivo function of hsa_circ_0018189 was verified by xenograft mouse models.

RESULTS

Hsa_circ_0018189 abundance was overexpressed in NSCLC cells and samples. Deficiency of hsa_circ_0018189 lowered NSCLC cell proliferative, migrating, invading, and glutamine metabolism capacities, and hsa_circ_0018189 silencing inhibited the growth of tumors in vivo. Hsa_circ_0018189 could up-regulate xCT by sponging miR-656-3p. And miR-656-3p downregulation or xCT overexpression partly overturned hsa_circ_0018189 knockdown or miR-656-3p mimic-mediated repression of NSCLC cell malignancy.

CONCLUSION

Hsa_circ_0018189 drove NSCLC growth by interacting with miR-656-3p and upregulating xCT.

circ_0008797 attenuates non-small cell lung cancer proliferation, metastasis, and aerobic glycolysis by sponging miR-301a-3p/SOCS2

PURPOSE

This paper firstly reported the exact function of circ_0008797 on non-small cell lung cancer (NSCLC) progression.

METHODS

NSCLC tissues/matched normal tissues were harvested from 88 NSCLC patients. RNA fluorescence in situ hybridization experiment was applied to detect circ_0008797 localization in NSCLC cells. circ_0008797 effect on NSCLC cells proliferation, migration, invasion, glucolysis, and apoptosis was researched by cell counting kit-8 assay, 5-ethynyl-2'deoxyuridine assay, Transwell experiment, glycolysis assay, and TUNEL assay. Dual luciferase reporter gene assay, RNA pull-down assay and RNA immunoprecipitation assay were used to verify the binding relationship between two genes. In vivo tumorigenesis and lung metastasis was performed using nude mice. Quantitative reverse transcription-polymerase chain reaction, immunohistochemistry and western blot were applied for genes expression detection. Hematoxylin and eosin staining was performed on lung tissues.

RESULTS

circ_0008797 was low expressed in NSCLC tissues and cell lines, associating with poor outcome (p <.05). circ_0008797 was mainly expressed in NSCLC cells cytoplasm. circ_0008797 inhibited proliferation, migration, invasion, and glycolysis, but enhanced apoptosis of NSCLC cells (p <.05). circ_0008797 attenuated malignant phenotype of NSCLC cells by sponging miR-301a-3p. circ_0008797 facilitated SOCS2 expression by sponging miR-301a-3p. SOCS2 knockdown partially reversed the inhibitory effect of miR-301a-3p inhibition on NSCLC cells malignant phenotype (p <.05). circ_0008797 attenuated NSCLC prolifearion and metastasis in vivo (p <.05).

CONCLUSION

circ_0008797 attenuates NSCLC proliferation, metastasis and aerobic glycolysis by sponging miR-301a-3p/SOCS2.

Long Noncoding RNAs and Circular RNAs in the Metabolic Reprogramming of Lung Cancer: Functions, Mechanisms, and Clinical Potential

As key regulators of gene function, long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) are generally accepted to be involved in lung cancer pathogenesis and progression. Recent research has clarified the phenomenon of metabolic reprogramming in lung cancer because of its significant role in tumor proliferation, migration, invasion, metastasis, and other malignant biological behaviors. Emerging evidence has also shown a relationship between the aberrant expression of lncRNAs and circRNAs and metabolic reprogramming in lung cancer tumorigenesis. This review provides insight regarding the roles of different lncRNAs and circRNAs in lung cancer metabolic reprogramming, by how they target transporter proteins and key enzymes in glucose, lipid, and glutamine metabolic signaling pathways. The clinical potential of lncRNAs and circRNAs as early diagnostic biomarkers and components of therapeutic strategies in lung cancer is further discussed, including current challenges in their utilization from the bench to the bedside and how to adopt a proper delivery system for their therapeutic use.

Circular RNA Eps15-homology domain containing protein 2 motivates proliferation, glycolysis but refrains autophagy in non-small cell lung cancer via crosstalk with microRNA-3186-3p and forkhead box K1

Numerous studies have clarified the involvement of circular RNAs (circRNAs) in modulating malignant behavior of non-small cell lung cancer (NSCLC), while the concrete mechanism is not completely elucidated. The aim of the study was to figure out the latent functions and molecular mechanisms of circRNA Eps15-homology domain containing protein 2 (EHD2) on NSCLC proliferation, glycolysis and autophagy. The results clarified in NSCLC elevated expression of circEHD2 and declined expression of microRNA (miR)-3186-3p. Repressive circEHD2 or enhancive miR-3186-3p facilitated cell apoptosis rate and autophagy substrates LC3BII and Beclin-1, but curbed the colony-formation and DNA replication ability of NSCLC, glucose consumption, lactic acid production, glycolytic rate-limiting enzyme HK-2 and glutamine hydrolase GLS1 and P62, while overexpressed circEHD2 was adverse. Meanwhile, the impacts of repressive and elevated circEHD2 on NSCLC were turned around via reduced miR-3186-3p or forkhead box k1 (FOXK1) separately. Mechanically, FOXK1 was augmented via circEHD2's competitive integration of miR-3186-3p. Depressive circEHD2 refrained NSCLC tumor growth, which was accelerated via enhancive one. All in all, circEHD2 accelerates the proliferation and glycolysis of NSCLC, but refrains autophagy and apoptosis via strengthening FOXK1 via the adsorption of miR-3186-3p, which is supposed to be a latent molecular target for NSCLC therapy later.

CircRNA SOD2 motivates non-small cell lungs cancer advancement with EMT via acting as microRNA-2355-5p’s competing endogenous RNA to mediate calmodulin regulated spectrin associated proteins-2

Circular RNAs (circRNAs) are closely linked with human cancer development such as non-small-cell lung cancer (NSCLC). However, the characteristics and specific functions of most circRNAs in NSCLC remained unknown. Previous studies have suggested that circRNA SOD2 (CircSOD2) expression was upregulated in a number of cancers. This study aimed to explore the functions of circSOD2 in NSCLC advancement with epithelial-mesenchymal transition (EMT). Expression profile analysis of circSOD2, miR-2355-5p, and calmodulin-regulated spectrin-associated protein 2 (CAMSAP2) was detected by real-time quantitative PCR (RT-qPCR). Transwell assay, cell migration assay, CCK8, ELISA, RIP assay, RNA pull-down assay, and Western blot analysis were performed to evaluate the functions of circSOD2, miR-2355-5p, and CAMSAP2. We found elevated expression of circSOD2 and CAMSAP2 while reduced expression of miR-2355-5p in NSCLC tumor tissues. Silencing or overexpression of CircSOD2 resulted in increased or decreased expression of miR-2355-5p, respectively. Mechanically, we showed that silencing of CircSOD2 and overexpression of miR-2355-5p resulted in the reduced rate of NSCLC cell proliferation. Inhibition of miR-2355-5p reversed the changes induced via silencing of CircSOD2. MiR-2355-5p binds to the CircSOD2 promoter and triggered its stimulation, which further activated circSOD2 expression. CircSOD2 suppression impaired lung cancer cell growth, cell migration, prohibited cell cycle progression, and in vivo tumor growth by targeting miR-2355-5p expression in NSCLC tissues. Meanwhile, increased expression of CAMSAP2 reversed the changes stimulated by the elevated level of miR-2355-5p in NSCLC progression. This innovative signaling axis CircSOD2/miR-2355-5p/CAMSAP2 illustrated the new horizon to investigate NSCLC tumorigenesis and provided new prognosis and treatment of NSCLC.

Hsa_circ_0006677 regulates special AT-rich binding protein-2-mediated tumor-suppressive effect via functioning as a miR-1245a sponge in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is still one of the most challenging malignant tumors. Deregulation of circular RNAs (circRNAs) is associated with NSCLC progression. However, the regulatory mechanism of circRNAs in NSCLC still needs to be studied. We selected a differentially expressed hsa_circ_0006677 (circ_0006677) in NSCLC through analyzing the GSE158695 and GSE112214 datasets. Expression of circ_0006677 was evaluated by real-time quantitative polymerase-chain reaction (RT-qPCR). Effects of circ_0006677 overexpression on NSCLC cell proliferation, apoptosis, migration, invasion, and stemness were determined by clonogenic, 5-ethynyl-2’-deoxyuridine (EdU), flow cytometry, transwell, and sphere formation assays. The regulatory mechanism of circ_0006677 was predicted by bioinformatics analysis and verified by dual-luciferase reporter and RIP assays. Animal experiments were carried out to validate the function of circ_0006677 in vivo. We observed the downregulation of circ_0006677 in NSCLC samples and cells. Functionally, circ_0006677 overexpression decreased xenograft tumor growth and restrained NSCLC cell proliferation, invasion, migration, stemness, and induced NSCLC cell apoptosis in vitro. Molecular mechanism experiments exhibited that circ_0006677 functioned as a miR-1245a sponge and mediated SATB2 expression through adsorbing miR-1245a. Either miR-1245a overexpression or SATB2 knockdown weakened circ_0006677 overexpression-mediated repression on proliferation, invasion, migration, and stemness. In conclusion, circ_0006677 regulated SATB2-mediated tumor-suppressive effect via acting as a miR-1245a sponge in NSCLC, providing a new mechanism for understanding the progression of NSCLC.

miR-3648 promotes lung adenocarcinoma-genesis by inhibiting SOCS2 (suppressor of cytokine signaling 2)

Lung adenocarcinoma (LUAD) is the most common histologic subtype of lung cancer and is associated with high morbidity and mortality. We aimed to study the effects of microRNA-3648 (miR-3648) on LUAD by inhibiting its downstream target suppressor of cytokine signaling 2 (SOCS2) mRNA. miR-3648 expression was measured by real-time quantitative PCR in LUAD and normal lung epithelial cell lines. The direct interaction between miR-3648 and SOCS2 mRNA was identified through luciferase reporter and RNA pull-down assays. Cell viability, migration, and invasion were examined using cell functional assays. MiR-3648 was found to be overexpressed in LUAD cells and tissues. Overexpression of miR-3648 significantly enhanced cell proliferation, migration, and invasion abilities in LUAD cells. Furthermore, SOCS2 was targeted by miR-3648, and co-transfection of a miR-3648 inhibitor or si-SOCS2 reversed the suppressive effects of SOCS2 in PC9 and A549 cells. miR-3648 enhanced the proliferation and promoted migration and invasion of LUAD by inhibiting SOCS2. In conclusion, our results indicate that miR-3648 plays a pivotal role in LUADe progression and might thus provide a novel therapeutic strategy for patients with LUAD.

Elevated Stratifin promotes cisplatin-based chemotherapy failure and poor prognosis in non-small cell lung cancer

Drug resistance is a key factor in the treatment failure of clinical non-small cell lung cancer (NSCLC) patients after adjuvant chemotherapy. Here, our results provide the first evidence that eukaryotic translation initiation factor 2b subunit delta (EIF2B4)-Stratifin (SFN) fusion and increased SFN expression are associated with chemotherapy tolerance and activation of the phosphatidylinositol 3 kinase/v-akt murine thymoma viral oncogene (PI3K/Akt) signaling pathway in NSCLC patients, suggesting that SFN might have potential prognostic value as a tumor biomarker for the prognosis of patients with NSCLC.