CircRNA circ_POLA2 Promotes Cervical Squamous Cell Carcinoma Progression via Regulating miR-326/GNB1

circRNA-SMO upregulates CEP85 to promote proliferation and migration of glioblastoma via sponging miR-326

Circular RNAs (circRNAs) play an important role in cancer development by sponging microRNAs (miRNAs) to regulate the signaling axis. However, more comprehensive mechanisms of circRNAs in glioblastoma need to be elucidated. RT-qPCR was used to detect the expression levels of circRNA-SMO and miR-326. Dual-luciferase reporter assays were conducted to verify the interaction among circRNA-SMO, miR-326, and CEP85. Flow cytometric analysis was performed to detect apoptosis. Western blotting was used to determine the protein levels of the different molecules. Animal xenograft experiments were performed to evaluate the role of circRNA-SMO in vivo. CircRNA-SMO was upregulated in glioblastoma tissues and glioblastoma cells. CircRNA-SMO downregulation inhibited the viability and colony-forming ability of the glioblastoma cells. In addition, miR-326 was downregulated in glioblastoma cells, which was verified to sponge circRNA-SMO and interact with CEP85. Moreover, circRNA-SMO inhibition induced the elevation of miR-326 and apoptosis, accompanied by a decrease in CEP85. CircRNA-SMO knockdown-mediated tumor inhibition was prevented by an miR-326 inhibitor. Furthermore, circRNA-SMO inhibition inhibited tumor growth in vivo, accompanied by an increase in miR-326 and a decline in CEP85 in tumor tissues. Conclusions. CircRNA-SMO sponges miR-326 to promote glioblastoma proliferation and migration by upregulating CEP85 expression. This study clarified the role of circRNA-SMO in the development of glioblastoma, providing novel insights for its treatment.

HOTAIR in colorectal cancer: structure, function, and therapeutic potential

lncRNAs play a vital part in cancer development by regulating gene expression. Among these, the lncRNA HOTAIR has gained considerable attention due to its entanglement in multiple cellular processes, including chromatin remodeling and gene regulation. HOTAIR has a complex structure consisting of multiple domains that interact with various protein complexes and RNA molecules. In colorectal cancer (CRC), HOTAIR expression is upregulated, and its overexpression has been correlated with poor patient prognosis and resistance to chemotherapy. HOTAIR has been found to regulate gene expression and promote cancer growth by interacting with specific miRNAs. In addition, HOTAIR has been implicated in the development of treatment resistance in colorectal cancer. To develop effective treatments, it's important to understand how HOTAIR regulates gene expression. This article discusses HOTAIR's structure, functions, and mechanisms in CRC and its potential as a target for therapy. The author also suggests future research directions to better understand HOTAIR's role in CRC progression and drug resistance.

CircGNB1 facilitates the malignant phenotype of GSCs by regulating miR-515-5p/miR-582-3p-XPR1 axis

Glioma is the most common and aggressive primary malignant brain tumor. Circular RNAs (circRNAs) and RNA-binding proteins (RBPs) have been verified to mediate diverse biological behaviors in various human cancers. Therefore, the aim of this study was to explore a novel circRNA termed circGNB1 and elucidate relative molecular mechanism in functional phenotypes, which might be a potential prognostic biomarker and therapeutic approach for glioma. CircGNB1 was upregulated in glioma and closely associated with the low poor prognosis. Functional assays demonstrated that circGNB1 overexpression promoted glioma stem cells (GSCs) viability proliferation, invasion, and neurosphere formation. Mechanistically, circGNB1 upregulated the expression of oncogene XPR1 via sponging miR-515-5p and miR-582-3p. The following experiments proved XPR1 could promote the malignant phenotype of GSCs via upregulating IL6 expression and activating JAK2/STAT3 signaling. Moreover, the RNA binding protein IGF2BP3 could bind to and maintain the stability of circGNB1, thus promoting the effects of circGNB1 on GSCs. Our study reveals that circGNB1 plays a crucial role in promoting tumorigenesis and malignant progression in glioma, which provides a promising cancer biomarker.

Research on Predicting the Occurrence of Hepatocellular Carcinoma Based on Notch Signal-Related Genes Using Machine Learning Algorithms

BACKGROUND/AIMS

Hepatocellular carcinoma, a highly malignant tumor, is difficult to diagnose, treat, and predict the prognosis. Notch signaling pathway can affect hepatocellular carcinoma. We aimed to predict the occurrence of hepatocellular carcinoma based on Notch signal-related genes using machine learning algorithms.

MATERIALS AND METHODS

We downloaded hepatocellular carcinoma data from the Cancer Genome Atlas and Gene Expression Omnibus databases and used machine learning methods to screen the hub Notch signal-related genes. Machine learning classification was used to construct a prediction model for the classification and diagnosis of hepatocellular carcinoma cancer. Bioinformatics methods were applied to explore the expression of these hub genes in the hepatocellular carcinoma tumor immune microenvironment.

RESULTS

We identified 4 hub genes, namely, LAMA4, POLA2, RAD51, and TYMS, which were used as the final variables, and found that AdaBoostClassifie was the best algorithm for the classification and diagnosis model of hepatocellular carcinoma. The area under curve, accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F1 score of this model in the training set were 0.976, 0.881, 0.877, 0.977, 0.996, 0.500, and 0.932; respectively. The area under curves were 0.934, 0.863, 0.881, 0.886, 0.981, 0.489, and 0.926. The area under curve in the external validation set was 0.934. Immune cell infiltration was related to the expression of 4 hub genes. Patients in the low-risk group of hepatocellular carcinoma were more likely to have an immune escape.

CONCLUSION

The Notch signaling pathway was closely related to the occurrence and development of hepatocellular carcinoma. The hepatocellular carcinoma classification and diagnosis model established based on this had a high degree of reliability and stability.

GNB1 promotes hepatocellular carcinoma progression by targeting BAG2 to activate P38/MAPK signaling

G-proteins are intracellular partners of G-protein-coupled receptors. As a member of the G-protein family, GNB1 has been shown to play a pro-cancer role in lung cancer and breast cancer. However, the biological function and detailed mechanisms of GNB1 in hepatocellular carcinoma progression are unclear. In this study, we investigated the effects of GNB1 and its possible mechanism of action in hepatocellular carcinoma (HCC). The clinical significance of GNB1 was evaluated in a large cohort of HCC patients, showing that GNB1 was overexpressed in HCC compared to adjacent normal liver tissues, and increased GNB1 expression was associated with poor prognosis. We also demonstrated that GNB1 enhances cell proliferation, colony formation, and cell migration and invasion in vitro and promotes the epithelial-to-mesenchymal transition process in HCC cells. Tumor xenograft model assay confirmed the oncogenic role of GNB1 in tumorigenicity in nude mice. Activation of P38 signaling was found in the GNB1 overexpressed HCC cells. Further intervention of P38 confirmed it as an important signaling pathway for the oncogenic role of GNB1 in HCC. Moreover, co-immunoprecipitation followed by liquid chromatograph-mass spectrometry identified that GNB1 exerted oncogenic functions via the interaction of BAG2 and activated P38 signaling pathway. Together, our results reveal that GNB1 plays a pivotal oncogenic role in HCC by promoting the P38 pathway via cooperating with BAG2. GNB1 may serve as a prognostic biomarker for patients with HCC.

Identification of fusions with potential clinical significance in melanoma

Though uncommon in melanoma, gene fusions may have therapeutic implications. Next generation sequencing-based clinical assays, designed to detect relevant gene fusions, mutations, and copy number changes, were performed on 750 melanomas (375 primary and 375 metastases) at our institution from 2014-2021. These included 599 (80%) cutaneous, 38 (5%) acral, 11 (1.5%) anorectal, 23 (3%) sinonasal, 27 (3.6%) eye (uveal/ conjunctiva), 11 (1.5%) genital (vulva/penile), and 41 (5.5%) melanomas of unknown primary. Sixteen fusions (2%) were detected in samples from 16 patients: 12/599 (2%) cutaneous, 2/38 (5%) acral, 1/9 (11%) vulva, 1/23(4.3%) sinonasal; and 12/16 (75%) fusions were potentially targetable. We identified two novel rearrangements: NAGS::MAST2 and NOTCH1::GNB1; and two fusions that have been reported in other malignancies but not in melanoma: CANT1::ETV4 (prostate cancer) and CCDC6::RET (thyroid cancer). Additional fusions, previously reported in melanoma, included: EML4::ALK, MLPH::ALK, AGAP3::BRAF, AGK::BRAF, CDH3::BRAF, CCT8::BRAF, DIP2B::BRAF, EFNB1::RAF1, LRCH3::RAF1, MAP4::RAF1, RUFY1::RAF1, and ADCY2::TERT. Fusion positive melanomas harbored recurrent alterations in TERT and CDKN2A, among others. Gene fusions were exceedingly rare (0.2%) in BRAF/RAS/NF1-mutant tumors and were detected in 5.6% of triple wild-type melanomas. Interestingly, gene rearrangements were significantly enriched within the subset of triple wild-type melanomas that harbor TERT promoter mutations (18% versus 2%, p < 0.0001). Thirteen (81%) patients were treated with immunotherapy for metastatic disease or in the adjuvant setting. Six of 12 (50%) patients with potentially actionable fusions progressed on immunotherapy, and 3/6 (50%) were treated with targeted agents (ALK and MEK inhibitors), 2 off-label and 1 as part of a clinical trial. One patient with an AGAP3::BRAF fusion positive melanoma experienced a 30-month long response to trametinib. We show that, detecting fusions, especially in triple wild-type melanomas with TERT promoter mutations, may have a clinically significant impact in patients with advanced disease who have failed front-line immunotherapy.

Profiling and integrated analysis of differentially expressed circRNAs in cervical cancer

Circular RNAs (circRNAs) are a new type of regulatory RNAs, which have been identified to play critical role in various tumors. However, the profiles and roles of circRNAs in cervical cancer (CCa) have not been fully understood and need to be further explored. In the present study, we performed circRNA array and mRNA-sequencing (mRNA-Seq) to profile the differentially expressed circRNAs and mRNAs in CCa tissues. A total of 397 differentially expressed circRNAs and 2138 differentially expressed mRNAs were detected, respectively. Subsequently, a circRNA-miRNA-mRNA regulatory network was constructed and indicated that hsa_circ_0026377 was downregulated in CCa. Overexpression of hsa_circ_0026377 inhibited HeLa and SiHa cells proliferation, migration and invasion. Collectively, this study provided new insights into the circRNA profiles in CCa and suggested that hsa_circ_0026377 might play important roles in CCa development.

Hsa_circ_0072008 regulates cell proliferation, migration, and invasion in cervical squamous cell carcinoma via miR-1305/helicase, lymphoid specific (HELLS) axis

Cervical squamous cell carcinoma (CESC) is one of the most common cancers in women. Recent studies have proved that circular RNAs (circRNAs) could regulate the progress of CESC, but the mechanism is still indistinct. In this work, we explored the roles of circ_0072008 in CESC. The expression levels of circ_0072008, microRNA-1305 (miR-1305) and mRNA of HELLS (helicase, lymphoid specific) were detected by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) in CESC tissues. Meanwhile, the level of HELLS was quantified by western blot analysis. Besides, the cell functions were examined by colony formation assay, 5-Ethynyl-2’-deoxyuridine (EdU) assay, wound healing assay, flow cytometry assay and western blot. Furthermore, the interaction between miR-1305 and circ_0072008 or HELLS was detected by dual-luciferase reporter assay. The function of circ_0072008 in CESC has also been further verified in vivo by xenograft model experiments. The levels of circ_0072008 and HELLS were upregulated, and the miR-1305 level was decreased in CESC tissues in contrast to that in normal tissues. For functional analysis, silencing circ_0072008 inhibited cell proliferation and cell migration, whereas enhanced cell apoptosis in CESC cells. In mechanism, circ_0072008 acted as a miR-1305 sponge to regulate the level of HELLS. Moreover, miR-1305 was confirmed to repress the progression of CESC cells by suppressing HELLS. Meanwhile, knockdown of circ_0072008 inhibited CESC cells growth in vivo. In conclusion, circ_0072008 facilitated CESC cell proliferation, migration, and invasion through increasing HELLS expression by regulating miR-1305, which also offered an underlying targeted therapy for CESC treatment.

AFAP1 antisense RNA 1 promotes retinoblastoma progression by sponging microRNA miR-545-3p that targets G protein subunit beta 1

The oncogenic role of actin filament-associated protein 1 antisense RNA 1 (AFAP1-AS1) has been reported in retinoblastoma (RB). However, the underlying regulatory mechanisms remain poorly understood. In this study, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blotting were performed to analyze the expression of AFAP1-AS1, microRNA miR-545-3p, or G protein subunit beta 1 (GNB1). Cell Counting Kit-8 (CCK-8) and Transwell migration assays were used to detect cell proliferation and migration. In addition, caspase-3 activity was monitored by caspase-3 activity assay. Luciferase reporter assays combined with RNA immunoprecipitation (RIP) and pull-down assays were performed to elucidate the target relationship between miR-545-3p and AFAP1-AS1 or GNB1. Xenograft tumor experiments were performed to evaluate RB cell growth in vivo. Increased AFAP1-AS1 and GNB1 expression in RB tissues and cells was confirmed by RT-qPCR; conversely, miR-545-3p was found to be downregulated in RB tissues and cells. AFAP1-AS1 overexpression resulted in increased proliferation and migration of RB cells, whereas AFAP1-AS1 silencing resulted in decreased proliferation and migration of RB cells. Moreover, AFAP1-AS1 was found to target miR-545-3p. The anti-miR-545-3p treatment phenocopied the effect of AFAP1-AS1 overexpression and promoted RB cell growth in vivo. miR-545-3p was found to directly target GNB1. GNB1 silencing resulted in reduced proliferation and migration of RB cells and attenuated the oncogenic effect of the miR-545-3p inhibitor. Thus, in this study, a novel ceRNA regulation network of AFAP1-AS1 in RB was identified, where AFAP1-AS1 regulated GNB1 expression by targeting miR-545-3p, ultimately driving RB progression.

circRNA circ_POLA2 increases microRNA-31 methylation to promote endometrial cancer cell proliferation

Circular RNA (circRNA) circ_POLA2 is an oncogene in lung and cervical cancers. However, the role of circ_POLA2 in other types of cancer is unknown. The present study investigated the role of circ_POLA2 in endometrial cancer (EC). The mRNA expression levels of circ_POLA2 and microRNA (miR)-31 in EC and paired adjacent normal tissues were analyzed using reverse transcription-quantitative (RT-qPCR). Overexpression of circ_POLA2 was achieved in the EC cell lines, and its effects on miR-31 mRNA expression level and methylation were evaluated using RT-qPCR and methylation-specific PCR (MSP), respectively. Cell proliferation was assessed using a Cell Counting Kit-8 assay. The results indicated that circ_POLA2 was highly expressed in EC tissue and inversely correlated with miR-31 mRNA expression level. MSP analysis showed that circ_POLA2 overexpression increased miR-31 methylation and RT-qPCR analysis showed that circ_POLA2 overexpression decreased miR-31 mRNA expression level. Furthermore, circ_POLA2 overexpression also increased EC cell proliferation, while miR-31 overexpression decreased cell proliferation. Finally, circ_POLA2 overexpression reduced the effects of miR-31 overexpression. In conclusion, circ_POLA2 may increase miR-31 methylation of miR-31 in EC cells to promote cancer cell proliferation.

Comprehensive Analysis of circRNA Expression Profiles During Cervical Carcinogenesis

Circular RNAs (circRNAs) are regulatory molecules that participate in the occurrence, development and progression of tumors. To obtain a complete blueprint of cervical carcinogenesis, we analyzed the temporal transcriptomic landscapes of mRNAs and circRNAs. Microarrays were performed to identify the circRNA and mRNA expression profiles of cervical squamous cell carcinoma (CSCC) and high-grade squamous intraepithelial lesion (HSIL) patients compared with normal controls (NC). Short time-series expression miner (STEM) was utilized to characterize the time-course expression patterns of circRNAs and mRNAs from NC to HSIL and CSCC. A total of 3 circRNA profiles and 3 mRNA profiles with continuous upregulated patterns were identified and selected for further analysis. Furthermore, functional annotation showed that the mRNAs were associated with DNA repair and cell division. The protein-protein interaction (PPI) network analysis revealed that the ten highest-degree genes were considered to be hub genes. Subsequently, a competing endogenous RNA (ceRNA) network analysis and real-time PCR validation indicated that hsa_circ_0001955/hsa-miR-6719-3p/CDK1, hsa_circ_0001955/hsa-miR-1277-5p/NEDD4L and hsa_circ_0003954/hsa-miR-15a-3p/SYCP2 were highly correlated with cervical carcinogenesis. Silencing of hsa_circ_0003954 inhibited SiHa cell proliferation and perturb the cell cycle in vitro. This study provides insight into the molecular events regulating cervical carcinogenesis, identifies functional circRNAs in CSCC, and improves the understanding of the pathogenesis and molecular biomarkers of CSCC and HSIL.

Circ-ABCB10 knockdown inhibits the malignant progression of cervical cancer through microRNA-128-3p/ZEB1 axis

AIMS

We focused on the detailed functions of circ-ABCB10 in cervical cancer (CC) development and its mechanisms.

BACKGROUND

The increasing findings have proposed the central roles of circular RNAs (circRNAs) in the tumorigenesis of various human cancers. Circ-ABCB10 displays promising oncogenic effect in several tumors.

METHODS

Circ-ABCB10 and miR-128-3p production levels in CC tissues and cells were tested through RT-qPCR. The association of circ-ABCB10 expression with clinicopathologic parameters of CC patients was statistically analyzed. Cell proliferation, invasion, apoptosis, and epithelial-mesenchymal transition (EMT) were evaluated by MTT, transwell invasion assays, flow cytometry analyses, and western blot examination of EMT markers. The binding activity between miR-128-3p and circ-ABCB10 or zinc finger E-box binding homeobox 1 (ZEB1) was explored through pull-down assay or luciferase reporter assay. The influence of circ-ABCB10 on CC tumorigenesis was evaluated by in vivo xenograft experiments.

RESULTS

The elevated circ-ABCB10 expression was determined in CC tissues and cells. Moreover, higher production level of circ-ABCB10 was close related to lymph-node metastasis, Federation of Gynecology and Obstetrics (FIGO) stage, and tumor size in CC patients. Loss of circ-ABCB10 weakened cell proliferative and invasive abilities, inhibited EMT, and induced apoptosis in CC. Loss of circ-ABCB10 inhibited ZEB1 expression by serving as a sponge of miR-128-3p in CC cells. Circ-ABCB10 sponged miR-128-3p to enhance cell proliferation, invasion, EMT and inhibit apoptosis in CC cells. Xenograft tumor assays confirmed that circ-ABCB10 knockdown inhibited CC tumor growth.

CONCLUSION

Our study suggests that circ-ABCB10 depletion inhibits proliferation, invasion and EMT and promotes apoptosis of cervical cancer cells through miR-128-3p/ZEB1 axis and represses CC tumor growth.

miR-326 inhibits the cell proliferation and cancer stem cell-like property of cervical cancer in vitro and oncogenesis in vivo via targeting TCF4

Background

Cervical cancer ranks as one of the most prevalent female malignancies globally, and its treatment with new targets has been the focus of current research. The present study set out to investigate the function of microRNA-326 (miR-326) in vitro and in vivo and to verify the direct targeting of transcription factor 4 (TCF4) by miR-326.

Methods

The detection of messenger RNA (mRNA) expressing miR-326 and TCF4 in cervical cancer cell lines and tumor samples was conducted using quantitative real-time polymerase chain (qRT-PCR). A dual-luciferase reporter assay was carried out to detect the target relationship of miR-326 with TCF4. A Cell Counting Kit-8 (CCK-8) assay was employed to detect the effect of miR-326 on CasKi cell viability. Flow cytometry and western blotting were employed to examine the effects of miR-326 on cancer stem cell (CSC)-like property. Tumor weight was measured in orthotopic xenograft mouse models. Immunohistochemistry was employed to analyze the protein expression levels of Ki-67, proliferating cell nuclear antigen (PCNA), CD44, and SRY-box 4 (SOX4).

Result

Downregulation of the mRNA expression levels of miR-326 was observed in cervical cancer cell lines and tumor tissue, while the levels of TCF4 were upregulated. The dual-luciferase reporter assay revealed binding of miR-326 to the three prime untranslated region (3'-UTR) of TCF4. In vitro assays demonstrated that miR-326 inhibited CasKi cell proliferation through regulating TCF4. miR-326 also suppressed the CSC-like property of CasKi cells by targeting TCF4. Furthermore, the protein expression levels of cyclin D1, β-catenin, and c-Myc were decreased when miR-326 was added to TCF4-transfected cells. In vivo assays demonstrated that miR-326 inhibited tumor weight, growth, and the protein expression levels of Ki-67, PCNA, CD44, SOX4, and β-catenin.

Conclusions

miR-326 acted in a tumor-suppressive manner through its regulation of TCF4, and has potential as a biomarker or therapeutic target for cervical cancer.

CircNEIL3 promotes cervical cancer cell proliferation by adsorbing miR-137 and upregulating KLF12

Background

CircRNAs play crucial roles in multiple tumours. However, the functions of most circRNAs in cervical cancer remain unclear.

Methods

This study collected GSE113696 data from the GEO database to search for differentially expressed circRNAs in cervical cancer. Quantitative reverse transcription PCR was used to detect the expression level of circNEIL3 in cervical cancer cells and tissues. Then, functional experiments in vitro and in vivo were performed to evaluate the effects of circNEIL3 in cervical cancer.

Results

CircNEIL3 was highly expressed in cervical cancer. In vivo and in vitro experiments verified that circNEIL3 enhanced the proliferation capacity of cervical cancer cells. RNA immunoprecipitation, luciferase reporter assay, pull-down assay, and fluorescent in situ hybridization confirmed the interaction between circNEIL3 and miR-137 in cervical cancer. A luciferase reporter assay showed that circNEIL3 adsorbed miR-137 and upregulated KLF12 to regulate the proliferation of cervical cancer cells.

Conclusions

CircNEIL3 is an oncogene in cervical cancer and might serve as a ceRNA that competitively binds to miR-137, thereby indirectly upregulating the expression of KLF12 and promoting the proliferation of cervical cancer cells.