Knockdown of Circ_CCNB2 Sensitizes Prostate Cancer to Radiation Through Repressing Autophagy by the miR-30b-5p/KIF18A Axis

Molecular panorama of therapy resistance in prostate cancer: a pre-clinical and bioinformatics analysis for clinical translation

Prostate cancer (PCa) is a malignant disorder of prostate gland being asymptomatic in early stages and high metastatic potential in advanced stages. The chemotherapy and surgical resection have provided favourable prognosis of PCa patients, but advanced and aggressive forms of PCa including CRPC and AVPC lack response to therapy properly, and therefore, prognosis of patients is deteriorated. At the advanced stages, PCa cells do not respond to chemotherapy and radiotherapy in a satisfactory level, and therefore, therapy resistance is emerged. Molecular profile analysis of PCa cells reveals the apoptosis suppression, pro-survival autophagy induction, and EMT induction as factors in escalating malignant of cancer cells and development of therapy resistance. The dysregulation in molecular profile of PCa including upregulation of STAT3 and PI3K/Akt, downregulation of STAT3, and aberrant expression of non-coding RNAs are determining factor for response of cancer cells to chemotherapy. Because of prevalence of drug resistance in PCa, combination therapy including co-utilization of anti-cancer drugs and nanotherapeutic approaches has been suggested in PCa therapy. As a result of increase in DNA damage repair, PCa cells induce radioresistance and RelB overexpression prevents irradiation-mediated cell death. Similar to chemotherapy, nanomaterials are promising for promoting radiosensitivity through delivery of cargo, improving accumulation in PCa cells, and targeting survival-related pathways. In respect to emergence of immunotherapy as a new tool in PCa suppression, tumour cells are able to increase PD-L1 expression and inactivate NK cells in mediating immune evasion. The bioinformatics analysis for evaluation of drug resistance-related genes has been performed.

Parkinson's Disease as a Risk Factor for Prostate Adenocarcinoma: A Molecular Point of View

INTRODUCTION

Cancer and neurodegeneration are two major leading causes of morbidity and death worldwide. Neurodegeneration results in excessive neuronal cell death, and cancer emerges from increased proliferation and resistance to cell death. Although most epidemiological studies support an inverse association between the risk for the development of neurodegenerative diseases and cancer, increasing evidence points to a positive correlation between specific types of cancer, like prostate adenocarcinoma (PRAD), and neurodegenerative diseases, like Parkinson's disease (PD).

METHODS

PD and PRAD differential genes were screened through the GEO database, and the differential genes were analyzed using David, String, GEPIA, Kaplan-Meier plotter, TIMER2.0, proteinatlas, cBioPortal, and CTD databases to elucidate the biological function and molecular mechanism of PD and PRAD-related genes.

RESULTS

Studies have shown that the hub gene and differentially expressed genes (DEGs) in PD were differentially expressed in PRAD, including CDC20, HSPA4L, ROBO1, DMKN, IFI27L2, LUZP2, PTN, PTGDS. In PRAD, the high expression of HSPA4L, ROBO1, DMKN, IFI27L2, PTN, and PTGDS genes was associated with longer survival, while the patients with low expression of CDC20 and LUZP2 genes had longer survival. The mRNA of CDC20 and LUZP2 were highly expressed, while the mRNAs of HSPA4L, ROBO1, DMKN, IFI27L2, and PTGDS were low expressed. Gene methylation did not affect the survival of patients. The high expression of miR-142, miR-186, miR-30a, miR-497, miR-590, miR-28, and miR-576 in microRNA (miRNA) might potentially be used as biomarkers for the progression of PD and PRAD and for the early diagnosis of PD and PRAD in the populations. The genes in this study were highly associated with B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells. Somatic mutation mainly focused on missense mutation. Therapeutic drugs included acetaminophen and valproic acid (VPA).

CONCLUSION

Bioinformatics was used to identify potential targets and novel molecular mechanisms that may serve as clinical markers for the diagnosis and treatment of PD and PRAD.

CircRNAs in Tumor Radioresistance

Circular RNAs (circRNAs) are endogenous, non-coding RNAs, which are derived from host genes that are present in several species and can be involved in the progression of various diseases. circRNAs’ leading role is to act as RNA sponges. In recent years, the other roles of circRNAs have been discovered, such as regulating transcription and translation, regulating host genes, and even being translated into proteins. As some tumor cells are no longer radiosensitive, tumor radioresistance has since become a challenge in treating tumors. In recent years, circRNAs are differentially expressed in tumor cells and can be used as biological markers of tumors. In addition, circRNAs can regulate the radiosensitivity of tumors. Here, we list the mechanisms of circRNAs in glioma, nasopharyngeal carcinoma, and non-small cell lung cancer; further, these studies also provide new ideas for the purposes of eliminating radioresistance in tumors.

Mechanism and Function of Circular RNA in Regulating Solid Tumor Radiosensitivity

Radiotherapy is an important tool in the treatment of malignant tumors, and exploring how to make radiotherapy more effective is a new way to break through the current bottleneck in the development of radiation oncology. Circular RNAs (circRNAs) are a special class of endogenous non-coding RNAs. Numerous studies have shown that circRNAs have shown great potential in regulating the biological functions of tumors, including proliferation, migration, invasion, and treatment resistance, and that differences in their expression levels are closely related to the clinical prognosis of tumor patients. This review systematically compares the mechanisms of circRNAs in the process of tumor development and radiosensitivity and provides insight into the clinical translation of circRNAs in radiotherapy.

Integrated analysis of mRNA-single nucleotide polymorphism-microRNA interaction network to identify biomarkers associated with prostate cancer

Background: Prostate cancer is one of the most common malignancies among men worldwide currently. However, specific mechanisms of prostate cancer were still not fully understood due to lack of integrated molecular analyses. We performed this study to establish an mRNA-single nucleotide polymorphism (SNP)-microRNA (miRNA) interaction network by comprehensive bioinformatics analysis, and search for novel biomarkers for prostate cancer.

Materials and methods: mRNA, miRNA, and SNP data were acquired from Gene Expression Omnibus (GEO) database. Differential expression analysis was performed to identify differentially expressed genes (DEGs) and miRNAs (DEMs). Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, protein-protein interaction (PPI) analysis and expression quantitative trait loci (eQTL) analysis of DEGs were conducted. SNPs related to DEMs (miRSNPs) were downloaded from the open-source website MirSNP and PolymiRTS 3.0. TargetScan and miRDB databases were used for the target mRNA prediction of miRNA. The mRNA-SNP-miRNA interaction network was then constructed and visualized by Cytoscape 3.9.0. Selected key biomarkers were further validated using the Cancer Genome Atlas (TCGA) database. A nomogram model was constructed to predict the risk of prostate cancer.

Results: In our study, 266 DEGs and 11 DEMs were identified. KEGG pathway analysis showed that DEGs were strikingly enriched in focal adhesion and PI3K-Akt signaling pathway. A total of 60 mRNA-SNP-miRNAs trios were identified to establish the mRNA-SNP-miRNA interaction network. Seven mRNAs in mRNA-SNP-miRNA network were consistent with the predicted target mRNAs of miRNA. These results were largely validated by the TCGA database analysis. A nomogram was constructed that contained four variables (ITGB8, hsa-miR-21, hsa-miR-30b and prostate-specific antigen (PSA) value) for predicting the risk of prostate cancer.

Conclusion: Our study established the mRNA-SNP-miRNA interaction network in prostate cancer. The interaction network showed that hsa-miR-21, hsa-miR-30b, and ITGB8 may be utilized as new biomarkers for prostate cancer.

Non-coding RNAs associated with autophagy and their regulatory role in cancer therapeutics

Cancer widely affects the world's health population and ranks second leading cause of death globally. Because of poor prognosis of various types of cancer such as sarcoma, lymphoma, adenomas etc., their high recurrence and metastasis rate and low early diagnosis rate have become concern lately. Role of autophagy in cancer progression is being studied since long. Autophagy is cell's self-degradative mechanism towards stress and has role in degradation of the cytoplasmic macromolecules which has potential to damage other cytosolic molecules. Autophagy can promote as well as inhibit tumorigenesis depending upon the associated protein combinations in cancer cells. Recent studies have shown that non-coding RNAs (ncRNAs) do not code for protein but play essential role in modulation of gene expression. At transcriptional level, different ncRNAs like lncRNAs, miRNAs and circRNAs directly or indirectly affect different stages of autophagy like autophagy-dependent and non-apoptotic cell death in cancer cells. This review focuses on the involvement of ncRNAs in autophagy and the modulation of several cancer signal transduction pathways in cancers such as lung, breast, prostate, pancreatic, thyroid, and kidney cancer.

CircRNAs in Malignant Tumor Radiation: The New Frontier as Radiotherapy Biomarkers

World Health Organization (WHO) data show that of the top 20 factors that threaten human life and health, cancer is at the forefront, and the therapeutic approaches for cancer consist of surgery, radiotherapy, chemotherapy and immunotherapy. For most highly metastatic and recurrent cancer, radiation therapy is an essential modality to mitigate tumor burden and improve patient survival. Despite the great accomplishments that have been made in clinical therapy, an inevitable challenge in effective treatment is radioresistance, the mechanisms of which have not yet been completely elucidated. In addition, radiosensitization methods based on molecular mechanisms and targets, and clinical applications are still inadequate. Evidence indicates that circular RNAs (circRNAs) are important components in altering tumor progression, and in influencing resistance and susceptibility to radiotherapy. This review summarizes the reasons for tumor radiotherapy resistance induced by circRNAs, and clarifies the molecular mechanisms and targets of action. Moreover, we determine the potential value of circRNAs as clinical indicators in radiotherapy, providing a theoretical basis for circRNAs-based strategies for cancer radiotherapy.

Targeting autophagy in prostate cancer: preclinical and clinical evidence for therapeutic response

Prostate cancer is a leading cause of death worldwide and new estimates revealed prostate cancer as the leading cause of death in men in 2021. Therefore, new strategies are pertinent in the treatment of this malignant disease. Macroautophagy/autophagy is a “self-degradation” mechanism capable of facilitating the turnover of long-lived and toxic macromolecules and organelles. Recently, attention has been drawn towards the role of autophagy in cancer and how its modulation provides effective cancer therapy. In the present review, we provide a mechanistic discussion of autophagy in prostate cancer. Autophagy can promote/inhibit proliferation and survival of prostate cancer cells. Besides, metastasis of prostate cancer cells is affected (via induction and inhibition) by autophagy. Autophagy can affect the response of prostate cancer cells to therapy such as chemotherapy and radiotherapy, given the close association between autophagy and apoptosis. Increasing evidence has demonstrated that upstream mediators such as AMPK, non-coding RNAs, KLF5, MTOR and others regulate autophagy in prostate cancer. Anti-tumor compounds, for instance phytochemicals, dually inhibit or induce autophagy in prostate cancer therapy. For improving prostate cancer therapy, nanotherapeutics such as chitosan nanoparticles have been developed. With respect to the context-dependent role of autophagy in prostate cancer, genetic tools such as siRNA and CRISPR-Cas9 can be utilized for targeting autophagic genes. Finally, these findings can be translated into preclinical and clinical studies to improve survival and prognosis of prostate cancer patients.

• Prostate cancer is among the leading causes of death in men where targeting autophagy is of importance in treatment;

• Autophagy governs proliferation and metastasis capacity of prostate cancer cells;

• Autophagy modulation is of interest in improving the therapeutic response of prostate cancer cells;

• Molecular pathways, especially involving non-coding RNAs, regulate autophagy in prostate cancer;

• Autophagy possesses both diagnostic and prognostic roles in prostate cancer, with promises for clinical application.

Identification of Pathologic and Prognostic Genes in Prostate Cancer Based on Database Mining

Background: Prostate cancer (PCa) is an epithelial malignant tumor that occurs in the urinary system with high incidence and is the second most common cancer among men in the world. Thus, it is important to screen out potential key biomarkers for the pathogenesis and prognosis of PCa. The present study aimed to identify potential biomarkers to reveal the underlying molecular mechanisms.

Methods: Differentially expressed genes (DEGs) between PCa tissues and matched normal tissues from The Cancer Genome Atlas Prostate Adenocarcinoma (TCGA-PRAD) dataset were screened out by R software. Weighted gene co-expression network analysis was performed primarily to identify statistically significant genes for clinical manifestations. Protein–protein interaction (PPI) network analysis and network screening were performed based on the STRING database in conjunction with Cytoscape software. Hub genes were then screened out by Cytoscape in conjunction with stepwise algorithm and multivariate Cox regression analysis to construct a risk model. Gene expression in different clinical manifestations and survival analysis correlated with the expression of hub genes were performed. Moreover, the protein expression of hub genes was validated by the Human Protein Atlas database.

Results: A total of 1,621 DEGs (870 downregulated genes and 751 upregulated genes) were identified from the TCGA-PRAD dataset. Eight prognostic genes [BUB1, KIF2C, CCNA2, CDC20, CCNB2, PBK, RRM2, and CDC45] and four hub genes (BUB1, KIF2C, CDC20, and PBK) potentially correlated with the pathogenesis of PCa were identified. A prognostic model with good predictive power for survival was constructed and was validated by the dataset in GSE21032. The survival analysis demonstrated that the expression of RRM2 was statistically significant to the prognosis of PCa, indicating that RRM2 may potentially play an important role in the PCa progression.

Conclusion: The present study implied that RRM2 was associated with prognosis and could be used as a potential therapeutic target for PCa clinical treatment.

Circ_0008500 Knockdown Improves Radiosensitivity and Inhibits Tumorigenesis in Breast Cancer Through the miR-758-3p/PFN2 Axis

Breast cancer is one of the most common malignancies worldwide. Circular RNAs (CircRNAs) were revealed to be implicated in the development of breast cancer. In this research, we aimed to investigate the role and underlying mechanism of circ_0008500 in the development and radiosensitivity of breast cancer. Using real-time quantitative PCR (RT-qPCR) and western blot, we found that hsa_circ_0008500 (circ_0008500) and profilin 2 (PFN2) were increased, while microRNA-758-3p (miR-758-3p) was decreased in breast cancer tissues and cells. Cell viability, the number of colonies, proliferation and apoptosis were detected using CCK-8, colony formation, EdU assays and flow cytometry, respectively. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were devoted to test the interaction between miR-758-3p and circ_0008500 or PFN2. The results showed that circ_0008500 knockdown inhibited cell growth, and facilitated cell apoptosis and radiosensitivity in breast cancer cells in vitro. Moreover, circ_0008500 regulated PFN2 expression by sponging miR-758-3p. Functionally, circ_0008500 knockdown regulated cell behaviors and radiosensitivity by targeting miR-758-3p to downregulate PFN2 expression in vitro. Additionally, in vivo tumor formation assay and immunohistochemistry (IHC) assay demonstrated that circ_0008500 knockdown enhanced the radiosensitivity and repressed tumor growth in vivo. In conclusion, circ_0008500 inhibition promoted the radiosensitivity and restrained the development of breast cancer by downregulating PFN2 expression via targeting miR-758-3p.

Circular RNAs and Drug Resistance in Genitourinary Cancers: A Literature Review

In recent years, systematic treatment has made great progress in genitourinary tumors. However, some patients develop resistance to the treatments, resulting in an increase in mortality. Circular RNAs (circRNAs) form a class of non-coding RNAs with high stability and significant clinical relevance. Accumulating evidence indicates that circRNAs play a vital role in cancer development and tumor chemotherapy resistance. This review summarizes the molecular and cellular mechanisms of drug resistance mediated by circRNAs to common drugs used in the treatment of genitourinary tumors. Several circRNAs were identified to regulate the responsiveness to systemic treatments in genitourinary tumors, including chemotherapies such as cisplatin and targeted therapies such as enzalutamide. Canonically, cicrRNAs participate in the competing endogenous RNA (ceRNA) network, or in some cases directly interact with proteins, regulate downstream pathways, and even some circRNAs have the potential to produce proteins or polypeptides. Several cellular mechanisms were involved in circRNA-dependent drug resistance, including autophagy, cancer stem cells, epithelial-mesenchymal transition, and exosomes. The potential clinical prospect of circRNAs in regulating tumor drug resistance was also discussed.

Hsa_circ_0014879 regulates the radiosensitivity of esophageal squamous cell carcinoma through miR-519-3p/CDC25A axis

Circular RNAs (circRNAs) play critical roles in regulating the radiosensitivity of various cancers, including esophageal squamous cell carcinoma (ESCC). This research aimed to explore the role and potential mechanism of hsa_circ_0014879 in regulating ESCC radioresistance. The levels of hsa_circ_0014879, microRNA-519-3p (miR-519-3p) and cell division cycle 25A (CDC25A) were measured using quantitative real-time PCR or western blot. Cell proliferation was evaluated by colony formation assay. Cell migration and invasion were assessed by transwell and scratch assays. The levels of epithelial-mesenchymal transition (EMT)-related proteins were detected by western blot. Xenograft assay was used to analyze the effect of hsa_circ_0014879 on radiosensitivity in vivo. The binding relationship among hsa_circ_0014879, miR-519-3p and CDC25A was confirmed by dual-luciferase reporter assay. Hsa_circ_0014879 and CDC25A were upregulated, whereas miR-519-3p was downregulated in radio-resistant ESCC tissues and cells. Depletion of hsa_circ_0014879 suppressed the proliferation, migration and invasion of radio-resistant ESCC cells. Hsa_circ_0014879 knockdown elevated radiosensitivity of radio-resistant cells by modulating miR-519-3p. Moreover, miR-519-3p enhanced the radiosensitivity of radio-resistant cells by targeting CDC25A. Also, hsa_circ_0014879 upregulated CDC25A via sponging miR-519-3p. Hsa_circ_0014879 silencing enhanced the radiosensitivity of ESCC via regulating the miR-519-3p/CDC25A pathway.

Circular RNAs in prostate cancer: Biogenesis,biological functions, and clinical significance

Circular RNAs (circRNAs) are covalently closed RNA molecules that play important regulatory roles in various tumors. Prostate cancer (PCa) is one of the most common malignant tumors in the world, with high morbidity and mortality. In recent years, more and more circRNAs have been found to be abnormally expressed and involved in the occurrence and development of PCa, including cell proliferation, apoptosis, invasion, migration, metastasis, chemotherapy resistance, and radiotherapy resistance. Most of the circRNAs regulate biological behaviors of cancer through a competitive endogenous RNA (ceRNA) regulatory mechanism, and some can exert their functions by binding to proteins. circRNAs are also associated with many clinicopathological features of PCa, including tumor grade, lymph node metastasis, and distant metastasis. In addition, circRNAs are potential diagnostic and prognostic biomarkers for PCa. Considering their critical regulatory roles in the progression of PCa, circRNAs would be the potential therapeutic targets. In this paper, the current research status of circRNAs in PCa is briefly reviewed.

Hsa_circ_0030586 promotes epithelial-mesenchymal transition in prostate cancer via PI3K-AKT signaling

Circular RNAs (CircRNAs) gain importance as regulatory molecules in prostate cancer (PCa), but molecular mechanism of most circRNAs in pathogenesis of PCa remains to be studied. This study aimed to explore the role of hsa_circ_0030586 in PCa. Gene Expression Omnibus database (GSE77661) was used to screen out candidate circRNAs. Quantitative real-time PCR was used to verify the relative expressions of circRNAs, miRNAs, and genes in PCa cells. A CCK-8 assay was used to evaluate the cells' proliferation. Transwell and wound healing assay were used to determine the cells' migration and invasion. Western blotting and immunohistochemistry were used to detect the protein expression of PI3K/AKT signaling proteins and epithelial-mesenchymal transition (EMT) markers. Furthermore, a nude mice tumorigenesis experiment in vivo was conducted to determine the function of hsa_circ_0030586 on PCa. Our results showed that hsa_circ_0030586 is significantly upregulated in PCa cells (p < 0.05). Its circular structure was confirmed via agarose gel electrophoresis and Sanger sequencing. Interfering with hsa_circ_0030586 in PC3 cells inhibited cell proliferation, migration, and invasion and led to the significant upregulation of E-cadherin and the significant downregulation of p-AKT/AKT, IKKα, PIK3CB, and Twist (all p < 0.05). Conversely, the hsa_circ_003058 interference fragment combined with the transfection of a miR-145-3p inhibitor could reverse the above effects. In vivo tumorigenesis of the xenograft model confirmed that interfering with hsa_circ_0030586 suppressed tumor cell proliferation and inhibited PI3K-AKT signaling and EMT in PC3 cells. Hsa_circ_0030586 is significantly upregulated in PCa cells and may promote EMT via PI3K-AKT signaling.

The Role and Clinical Potentials of Circular RNAs in Prostate Cancer

Globally, prostate cancer (PCa) is the second most commonly diagnosed cancer in men globally. Early diagnosis may help in promoting survival in the affected patients. Circular RNAs (circRNAs) are a novel class of non-coding RNAs (ncRNAs) which have been found to show extensive dysregulation in a handful of human diseases including cancers. Progressions in RNA identification techniques have provided a vast number of circRNAs exhibiting either up-regulation or down-regulation in PCa tissues compared to normal adjacent tissues. The mechanism of action is not clear for most of dysregulated circRNAs. Among them, function of a number of newly identified dysregulated circRNAs have been assessed in PCa cells. Increase in cell proliferation, migration, invasion, and metastasis have been reported for up-regulated circRNAs which suggest their role as oncogenes. On the other hand, down-regulated circRNAs have shown tumor suppressing actions in experimental studies. Furthermore, in a majority of studies, circRNAs have been found to sponge microRNAs (miRNAs), negatively regulating expression or activity of the downstream miRNAs. Additionally, they have been identified in interaction with regulatory proteins. This axis consequently regulates a signaling pathway, a tumor suppressor, or an oncogene. Easy, quick, and reliable detection of circRNAs in human body fluids also suggests their potentials as biomarker candidates for diagnosis and prediction of prognosis in PCa patients. In this review, we have discussed the role and potentials of a number of dysregulated circRNAs in PCa.

The Emerging Role of Circular RNAs in Prostate Cancer: A Systematic Review

Prostate cancer is one of the most common malignant tumors that threaten the health of men. It is urgent to explore new molecular targets and develop new drugs for the treatment of prostate cancer. Circular RNAs (circRNAs) are aberrantly expressed in various malignant tumors. The dysregulated circRNAs are involved in the metastasis, tumor growth, drug resistance, and immunosuppression of malignant tumors. The present review systematically summarized publications concerning the biological implications of circRNAs in prostate cancer. The PubMed and Web of Science databases were used to retrieve publications concerning circRNAs and prostate cancer until June 16, 2021. The following keywords were used in the literature search: (circRNA OR circular RNA) AND prostate cancer. 73 publications were enrolled in the present systematic review to summarize the role of circRNAs in prostate cancer. The dysregulated and functional circRNAs were involved in the cell cycle, proliferation, migration, invasion, metastasis, drug resistance and radiosensitivity of prostate cancer. In addition, circRNAs could function through EVs and serve as prognostic and diagnostic biomarkers. Certain circRNAs were correlated with clinicopathological features of prostate cancer. A comprehensive review of the molecular mechanism of the tumorigenesis and progression of prostate cancer may contribute to the development of new therapies of prostate cancer in the future.

Autophagy-related circRNA evaluation reveals hsa_circ_0001747 as a potential favorable prognostic factor for biochemical recurrence in patients with prostate cancer

Prostate cancer (PCa) is a common high-incidence malignancy in men, some of whom develop biochemical recurrence (BCR) in the advanced stage. However, there are currently no accurate prognostic indicators of BCR in PCa. The aim of our study was to identify an autophagy-related circular RNA prognostic factor of BCR for patients with PCa. In this study, immunochemistry revealed that the classic autophagy marker MAP1LC3B was positively correlated with Gleason score. Least absolute shrinkage and selector operator regression were conducted to develop a novel prognostic model with tenfold cross-validation and an L1 penalty. Five autophagy-related circRNA signatures were included in the prognostic model. Patients with PCa were ultimately divided into high- and low-risk groups, based on the median risk score. Patients with PCa, who had a high risk score, were more likely to develop BCR in a shorter period of time. Univariate and multivariate Cox regression analyses demonstrated that the risk score was an independent variable for predicting BCR in PCa. In addition, a prognostic nomogram integrated with the risk score and numerous clinicopathological parameters was developed to accurately predict 3- and 5-year BCR of patients with PCa. Finally, the hsa_circ_0001747 signature was selected for further experimental verification in vitro and in vivo, which showed that downregulated hsa_circ_0001747 might facilitate PCa via augmenting autophagy. Our findings indicate that the autophagy-related circRNA signature hsa_circ_0001747 may serve as a promising indicator for BCR prediction in patients with PCa.

Knockdown of hsa_circ_0001275 reverses dexamethasone-induced osteoblast growth inhibition via mediation of miR-377/CDKN1B axis

BACKGROUND

Osteoporosis affects the quality of life among middle-aged and elderly individuals. In addition, dysfunction of osteoblasts can lead to the progression of osteoporosis. Circular (circ)RNAs are involved in various types of diseases, including osteoporosis. Moreover, it has been reported that hsa_circ_0001275 expression is upregulated in osteoporosis. However, the effects of hsa_circ_0001275 on the growth of osteoblasts remain unclear.

METHODS

In the present study, the gene and protein expression levels in hFOB1.19 cells were detected via reverse transcription-quantitative (RT-qPCR) and western blot analyses, respectively. In addition, alkaline phosphatase (ALP) activity and calcium nodules were examined by ALP and alizarin red staining, respectively. Cell proliferation was measured using the Cell Counting Kit-8 assay. Cell apoptosis and cell cycle were analyzed by flow cytometry. Furthermore, dual luciferase reporter and RNA pull-down assay were used to confirm the association among hsa_circ_0001275, microRNA (miR)-377 and CDKN1B.

RESULTS

DEX-induced hFOB1.19 cell growth inhibition was significantly reversed by silencing hsa_circ_0001275. Moreover, DEX significantly increased ALP activity and calcium nodules in hFOB1.19 cells, while this effect was significantly reversed in the presence of hsa_circ_0001275 small interfering RNA. In addition, miR-377 was sponged by hsa_circ_0001275 and CDKN1B was directly targeted by miR-377 in hFOB1.19 cells. Furthermore, the therapeutic effect of hsa_circ_0001275 knockdown on osteoporosis was notably reversed by miR-377 antagomir.

CONCLUSION

The data demonstrated that knockdown of hsa_circ_0001275 reversed DEX-induced osteoblast growth inhibition via activation of the miR-377/CDKN1B axis. Therefore, this study might shed new lights on the treatment of osteoporosis.

Advances of circular RNAs in thyroid cancer: An overview

Circular RNA (circRNA) is a general term for a type of single-stranded RNAs, they are primarily generated via exon back-splice process in precursor mRNAs (pre-mRNAs). circRNAs refer to an emerging type of endogeneity-correlated closed molecules of RNA in a covalent manner. They mainly function as microRNA sponges, protein brackets, and regulatory element in transcription and splicing process. Recently, it has also starting been noticed that they serve as extraordinary models involved in polypeptides producing process. Although circRNAs have been extensively studied, their function in thyroid carcinoma is still lacking. Thus, we present the latest advances in circRNA research and summarize their fundamental rules of regulating process as well as the mechanism. More importantly, We mainly review the role and mechanism of circRNA in thyroid cancer, which provides an emerging perspective and theoretically supports the treatment of thyroid cancer.

The influence of circular RNAs on autophagy and disease progression

Circular RNAs (circRNAs) are non-coding RNAs that have attracted considerable attention in recent years. Owing to their distinct circular structure, circRNAs are stable in cells. Autophagy is a catabolic process that helps in the degradation and recycling of harmful or inessential biological macromolecules in cells and enables cells to adapt to stress and changes in the internal and external environments. Evidence has shown that circRNAs influence the course of a disease by regulating autophagy, which indicates that autophagy is involved in the onset and development of various diseases and can affect drug resistance (for example, it affects cisplatin resistance in tumors). In this review, we summarized the role of circRNAs in autophagy and their influence on disease onset and progression as well as drug resistance. The review will expand our understanding of tumors as well as cardiovascular and neurological diseases and also suggest novel therapeutic strategies.Abbreviations: ACR: autophagy-related circRNA; ADSCs: adipogenic mesenchymal stem cells; AMPK: AMP-activated protein kinase; ATG: autophagy related; BCL2: BCL2 apoptosis regulator; BECN1: beclin 1; ceRNA: competing endogenous RNA; circRNA: circular RNA; CMA: chaperone-mediated autophagy; EPCs: endothelial progenitor cells; LE/MVBs: late endosomes/multivesicular bodies; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; NSCLC: non-small cell lung cancer; PDLSCs: periodontal ligament stem cells; PE: phosphatidylethanolamine; PtdIns: phosphatidylinositol; PtdIns3K: phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate 1,2-dipalmitoyl; PTEN: phosphatase and tensin homolog; RBPs: RNA-binding proteins; SiO₂: silicon dioxide; TFEB: transcription factor EB; ULK: unc-51 like autophagy activating kinase 1.

Circ_0055625 knockdown inhibits tumorigenesis and improves radiosensitivity by regulating miR-338-3p/MSI1 axis in colon cancer

BACKGROUND

Radiotherapy is a main therapeutic method for cancers, including colon cancer. In the current study, we aim to explore the effects of circular RNA (circRNA) circ_0055625 in the progression and radiosensitivity of colon cancer and the underlying mechanism.

METHODS

The expression of circ_0055625 and musashi homolog 1 (MSI1) mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). MSI1 protein expression was determined by Western blot. Cell proliferation was assessed by cell counting kit-8 (CCK-8) and colony formation assays. Cell survival fraction, apoptosis, and invasion were investigated by colony formation assay, flow cytometry analysis, and transwell invasion assay, respectively. Cell migration was detected by wound-healing and transwell migration assays. The binding relationship between microRNA-338-3p (miR-338-3p) and circ_0055625 or MSI1 was predicted by online databases and identified by Dual-Luciferase Reporter Assay. The effects of circ_0055625 silencing on the tumor formation and radiosensitivity of colon cancer in vivo were explored by in vivo tumor formation assay.

RESULTS

Circ_0055625 and MSI1 were upregulated in colon cancer tissues and cells relative to control groups. Radiation treatment apparently increased the expression of circ_0055625 and MSI1 in colon cancer cells. Circ_0055625 knockdown or MSI1 silencing repressed cell proliferation, migration, and invasion and promoted cell apoptosis and radiosensitivity in colon cancer. Also, circ_0055625 silencing-mediated effects were attenuated by MSI1 overexpression. Additionally, circ_0055625 silencing reduced MSI1 expression, which could be attenuated by miR-338-3p inhibitor. Mechanically, circ_0055625 acted as a sponge for miR-338-3p to regulate MSI1. Furthermore, circ_0055625 knockdown hindered tumor growth and improved radiosensitivity in vivo.

CONCLUSION

Circ_0055625 repression inhibited the progression and radioresistance of colon cancer by downregulating MSI1 through sponging miR-338-3p. This result might provide a theoretical basis for improving the therapy of colon cancer with radiation.

KIF18A knockdown reduces proliferation, migration, invasion and enhances radiosensitivity of esophageal cancer

Kinesin family member 18A (KIF18A) is significantly overexpressed and is related to the poor prognosis of human cancers. However, the function of KIF18A in esophageal cancer (EC) is still unclear. Human EC cell lines were used in this study. KIF18A expression in human tissues was assessed using Gene Expression Profiling Interactive Analysis 2.0 (GEPIA2). The expressions of KIF18A or IGF2BP3 in EC cells were detected using qRT-PCR or WB. Cells were transfected using si-KIF18A, si-IGF2BP3, and plasmid IGF2BP3. The abilities of proliferation, migration, and invasion were detected by EdU, wound-healing, and transwell assay. The interaction between KIF18A and IGF2BP3 was predicted by starBase v3.0 and studied by RIP and RNA stability assay. Colony formation assay was used to reflect the changes of radiosensitivity in EC cells. KIF18A was upregulated in EC, and KIF18A knockdown inhibited EC cell proliferation, migration, invasion, and radioresistance. The prediction in starBase and RIP assay results showed that KIF18A mRNA could bind to IGF2BP3 protein in EC cells. RNA stability assay was performed to confirm that IGF2BP3 affects mRNA stability of KIF18A. Further studies also showed that IGF2BP3 could positively regulate KIF18A on proliferation, migration, invasion, and radioresistance. Our findings first revealed an oncogenic effect of KIF18A in human EC progression. KIF18A expression was associated with radioresistance of EC cells. The binding relationship between KIF18A and IGF2BP3 might influence the mRNA stability of KIF18A in EC cell lines.

Bioinformatics analysis identified hub genes in prostate cancer tumorigenesis and metastasis

OBJECTIVE

Prostate cancer (PCa) is the most frequent cancer found in males worldwide, and its mortality rate is increasing every year. To discover key molecular changes in PCa development and metastasis, we analyzed microarray data of localized PCa, metastatic PCa and normal prostate tissue samples from clinical specimens.

METHODS

Gene expression profiling datasets of PCa were analyzed online. The DAVID was used to perform GO functional and KEGG pathway enrichment analyses. CytoHubba in Cytoscape software was applied to identify hub genes. Survival data were downloaded from GEPIA. Gene expression data were obtained from ONCOMINE and UALCAN.

RESULTS

We obtained 4 sets of differentially expressed genes (DEGs), DEGs 1: a comparison of the gene expression between 4 normal prostate and 5 localized PCa samples in GSE27616; DEGs 2: a comparison of the gene expression between 6 normal prostate and 7 localized PCa samples in GSE3325; DEGs 3: a comparison of the gene expression between 5 localized PCa and 4 metastatic PCa samples in GSE27616; DEGs 4: a comparison of the gene expression between 7 localized PCa and 6 metastatic PCa samples in GSE3325. A comparison of these 4 sets of genes revealed 51 overlapped genes. GO function analysis revealed enrichment of the 51 DEGs in functions related to the proteinaceous extracellular matrix and centrosome, protein homodimerization activity and chromatin binding were the main functions of these genes, which participated in regulating cell division, mitotic nuclear division, proteinaceous extracellular matrix, cell adhesion and apoptotic process. KEGG pathway analysis indicated that these identified DEGs were mainly enriched in progesterone-mediated oocyte maturation, oocyte meiosis and cell cycle. We defined the 16 genes with the highest degree of connectivity as the hub genes in the 51 overlapped DEGs. Cox regression revealed TOP2A, CCNB2, BUB1, CDK1 and EZH2 were related to Disease-free survival (DFS). The expression levels of the 5 genes were 2.232-, 1.786-, 2.303-, 1.699-, and 1.986-fold higher in PCa than the levels in normal tissues, respectively (P < 0.05). We obtained 20 hub genes from DEGs by the comparison of normal prostate tissue vs. localized cancer tissue. Among them, KIF20A, CDKN3, PBK and CDCA2, were expressed higher in PCa than in normal tissues, and were associated with the DFS of PCa patients. Meanwhile, we obtained 20 hub genes from DEGs by the comparison of localized cancer tissue vs. metastatic cancer tissue. Cox regression revealed PLK1, CCNA2 and CDC20, were associated with both the DFS and overall survival of PCa patients.

CONCLUSIONS

The results suggested that the functions of KIF20A, CDKN3, PBK and CDCA2 may contribute to PCa development and the functions of PLK1, CCNA2 and CDC20 may contribute to PCa metastasis. Meanwhile, the functions of TOP2A, CCNB2, BUB1, CDK1 and EZH2 may contribute to both PCa development and metastasis.

miR-30b-5p inhibits cancer progression and enhances cisplatin sensitivity in lung cancer through targeting LRP8

Accumulated evidence has demonstrated that miRNAs are closely implicated in lung carcinogenesis. Herein, we explored the expression pattern of miR-30b-5p in lung cancer, and aimed to uncover miR-30b-5p roles in lung cancer progression and drug resistance. miR-30b-5p expression profiles in lung cancer tissues and the matched non-tumor tissues were determined by using qPCR. Cell viability, migration, invasion and in vivo tumorigenesis were determined by using the CCK-8, colony formation, wound healing, transwell chambers experiments and tumor xenograft models. RNA immunoprecipitation (RIP) and dual luciferase reporter experiments were applied to evaluate the relationship between miR-30b-5p and LRP8. The results demonstrated that miR-30b-5p showed a low expression profile in lung cancer tissues and cells, and closely linked to poor prognosis and malignant clinical process. Cell viability, migration, invasiveness and tumorigenesis were significantly weakened following miR-30b-5p overexpression in A549 and NCI-H1299 cells, while cell apoptosis rates were increased. In addition, miR-30b-5p was lowly expressed in A549/DDP (a cisplatin drug resistant cell line) as compared with A549 cells, and miR-30b-5p increased A549/DDP cell sensitivity to DDP. However, these above roles of miR-30b-5p were all significantly impaired following the overexpression of LRP8 which was overexpressed in lung cancer tissues. Collectively, this study demonstrated that miR-30b-5p functions as a tumor suppressor in lung cancer, and re-sensitizes lung cancer cells to DDP by targeting LRP8.

Roles of circRNAs in prostate cancer: Expression, mechanism, application and potential

Circular RNA (circRNA) is a member of the non-coding RNA family that is formed by trans-splicing. Because of its unique structure and characteristics, it has extraordinary value for the diagnosis, treatment, and prognosis of diseases, particularly for tumors. Study of the role of circRNAs in the occurrence and development of prostate cancer has made considerable progress, but many areas remain that require further exploration and improvement. This article describes research into sequencing expression profiles, expression regulation, potential value as biomarkers, mechanism in the occurrence and development, therapy resistance, relationship with clinicopathological features, and prognostic value of circRNAs in prostate cancer from the past few years.

Silencing circSLC19A1 Inhibits Prostate Cancer Cell Proliferation, Migration and Invasion Through Regulating miR-326/MAPK1 Axis

Background

Emerging evidence indicates that circular RNAs (circRNAs), which form as covalently closed loops, play a regulatory role in various types of cancer, including prostate cancer (PCa). CircSLC19A1, one kind of circRNA, was subjected to the study and its role in PCa was explored.

Methods

Expressions of circSLC19A1, miR-326 and MAPK1 in PCa tissues and cells were assessed by qRT-PCR. CircSLC19A1 was identified by RNase R treatment. The binding relations between circSLC19A1 and miR-326 and between miR-326 and MAPK1 were predicted by RegRNA2.0 or Targetscan7.2 and further confirmed by dual-luciferase reporter assay. Pearson correlation analysis of the correlation among circSLC19A1, miR-326 and MAPK1 was performed. CCK-8, cell colony formation, wound healing and Transwell assays were used to assess PCa cell viability, proliferation, migration and invasion, respectively.

Results

CircSLC19A1 expression was up-regulated in PCa tissue and cell cytoplasm. Silencing circSLC19A1 inhibited PCa cell viability, proliferation, migration, invasion and miR-326 expression. MiR-326 inhibitor promoted the luciferase activities of circSLC19A1 and MAPK1, increased MAPK1 expression and facilitated PCa cell progression. MiR-326 expression was down-regulated in PCa tissue and there was a negative correlation between miR-326 and circSLC19A1 expressions. MAPK1 expression was up-regulated in PCa tissue. There was a negative correlation between MAPK1 and miR-326 expressions as well as a positive correlation between MAPK1 and circSLC19A1 expressions. Silencing MAPK1 promoted the viability, proliferation, migration, and invasion of PCa cells co-transfected with siRNA-circSLC19A1a and miR-326 inhibitor.

Conclusion

CircSLC19A1 silencing inhibited PCa cell proliferation, migration and invasion through regulating miR-326/MAPK1 axis.