MiR-421 promotes the development of osteosarcoma by regulating MCPIP1 expression

CircNRD1 elevates THAP domain containing 11 through sequestering microRNA-421 to inhibit gastric cancer growth and tumorigenesis

We explored the role and mechanism of circular RNAcircNRD1 in gastric cancer (GC) progression, aiming to identify new bio-markers for the treatment and prognosis of GC patients. The RNA expression was examined by reverse transcription-quantitative polymerase chain reaction. Cell proliferation, migration and invasion were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay, scratch assay and transwell assay. Western blot assay was conducted for protein expression measurement. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were conducted to verify the interaction between microRNA-421 (miR-421) and circNRD1 or THAP domain containing 11 (THAP11). Xenograft tumor model was established to perform in vivo experiments. CircNRD1 was notably downregulated in GC tissues and cell lines. Additionally, decreased circNRD1 level was closely associated with advanced tumor stage and dismal prognosis in GC patients. CircNRD1 overexpression suppressed the proliferation and metastasis of GC cells. CircNRD1 acted as a molecular sponge for miR-421 in GC cells, and the antitumor impacts of circNRD1 overexpression in GC cells could be alleviated by miR-421 overexpression. miR-421 directly targeted THAP11, and circNRD1 could up-regulate THAP11 expression in GC cells through sponging miR-421. THAP11 knockdown reversed circNRD1 overexpression-induced tumor suppressing effects in GC cells. CircNRD1 overexpression significantly blocked tumor growth in vivo. CircNRD1 suppressed the proliferation and metastasis of GC cells in vitro and blocked tumor growth in vivo via modulating miR-421/THAP11 axis.

Regulation of Osteosarcoma Cell Proliferation, Migration, and Invasion by miR-143 and miR-199a Through COX-2 Targeting

Objective

To investigate the biological role of miR-143 and miR-199a in mediating the progression of osteosarcoma (OS) by targeting cyclooxygenase (COX-2).

Introduction

COX-2 plays a crucial role in the development and progression of OS. However, the specific regulatory mechanisms of COX-2 in OS are still not well understood.

Methods

The expression levels of COX-2, miR-143 and miR-199a in OS tissues were detected using immunohistochemistry, qPCR, or western blot assays. The targeting relationship between miRNAs and COX-2 was determined. The effect of miRNA and COX-2 on OS cells was evaluated in vitro and in vivo.

Results

COX-2 expression was upregulated while miR-143 and miR-199a were downregulated in OS tissues. miR-143 and miR-199a suppressed the proliferation, migration, and invasion of OS cells. The dual-luciferase reporter gene assay showed that COX-2 was a direct target of miR-143 and miR-199a. Genetic knockdown of COX-2 significantly suppressed cell proliferation, induced apoptosis, and inhibited migration and invasion of OS cells. The expression levels of COX-2 and PGE2 were decreased after the overexpression of miR-143 and miR-199a. Additionally, COX-2 silencing inhibited the tumorigenesis of OS and the synthesis of PGE2 in vivo.

Conclusions

miR-143 and miR-199a/COX-2 axis modulates the proliferation, invasion, and migration in osteosarcoma.

Joint global and local interpretation method for CIN status classification in breast cancer

Breast cancer is among the cancer types with the highest numbers of new cases. The study of this disease from a microscopic perspective has been a prominent research topic. Previous studies have shown that microRNAs (miRNAs) are closely linked to chromosomal instability (CIN). Correctly predicting CIN status from miRNAs can help to improve the survival of breast cancer patients. In this study, a joint global and local interpretation method called GL_XGBoost is proposed for predicting CIN status in breast cancer. GL_XGBoost integrates the eXtreme Gradient Boosting (XGBoost) and SHapley Additive exPlanation (SHAP) methods. XGBoost is used to predict CIN status from miRNA data, whereas SHAP is used to select miRNA features that have strong relationships with CIN. Furthermore, SHAP's rich visualization strategies enhance the interpretability of the entire model at the global and local levels. The performance of GL_XGBoost is validated on the TCGA-BRCA dataset, and it is shown to have an accuracy of 78.57% and an area under the curve value of 0.87. Rich visual analysis is used to explain the relationships between miRNAs and CIN status from different perspectives. Our study demonstrates an intuitive way of exploring the relationship between CIN and cancer from a microscopic perspective.

Circ_0049271 targets the miR-1197/PTRF axis to attenuate the malignancy of osteosarcoma

BACKGROUND

Circular RNAs (circRNAs) perform key regulatory functions in osteosarcoma (OS) tumorigenesis. In this study, we aimed to explore the detailed action mechanisms of circ_0049271 in OS progression.

METHODS

Cell colony formation, cell counting kit-8, and transwell assays were performed to assess the proliferation and invasion of OS cells. Quantitative reverse transcription-polymerase chain reaction and western blotting were used to determine the expression levels of polymerase 1 and transcript release factor (PTRF), microRNA (miR)-1197, and circ_0049271 in OS cells. Furthermore, RNA immunoprecipitation and dual luciferase assays were conducted to explore the targeted relationships among PTRF, miR-1197, and circ_0049271. Finally, a tumor formation assay was conducted to determine the effects of circ_0049271 on in vivo tumor growth in mice.

RESULTS

High expression levels of miR-1197 and low levels of circ_0049271 and PTRF were observed in OS cells. circ _0049271 targeted miR-1197 to mediate PTRF expression. Moreover, the proliferation and invasion of OS cells were repressed by circ_0049271 or PTRF overexpression and increased by miR-1197 upregulation. Enforced circ_0049271 also impeded tumor growth in vivo. Upregulation of miR-1197 reversed the antitumor effects of circ_0049271 on OS progression in vitro; however, PTRF overexpression attenuated the cancer-promoting effects of miR-1197 on OS in vitro.

CONCLUSIONS

Our findings revealed that circ_0049271 targeted the miR-1197/PTRF axis to attenuate the malignancy of OS, suggesting a potential target for its clinical treatment.

Multi-Anticancer Activities of Phytoestrogens in Human Osteosarcoma

Phytoestrogens are plant-derived bioactive compounds with estrogen-like properties. Their potential health benefits, especially in cancer prevention and treatment, have been a subject of considerable research in the past decade. Phytoestrogens exert their effects, at least in part, through interactions with estrogen receptors (ERs), mimicking or inhibiting the actions of natural estrogens. Recently, there has been growing interest in exploring the impact of phytoestrogens on osteosarcoma (OS), a type of bone malignancy that primarily affects children and young adults and is currently presenting limited treatment options. Considering the critical role of the estrogen/ERs axis in bone development and growth, the modulation of ERs has emerged as a highly promising approach in the treatment of OS. This review provides an extensive overview of current literature on the effects of phytoestrogens on human OS models. It delves into the multiple mechanisms through which these molecules regulate the cell cycle, apoptosis, and key pathways implicated in the growth and progression of OS, including ER signaling. Moreover, potential interactions between phytoestrogens and conventional chemotherapy agents commonly used in OS treatment will be examined. Understanding the impact of these compounds in OS holds great promise for developing novel therapeutic approaches that can augment current OS treatment modalities.

CircECE1 promotes osteosarcoma progression through regulating RAB3D by sponging miR-588

BACKGROUND

Circular RNAs (circRNAs) have been confirmed to be involved in cancer pathogenesis. However, the underlying mechanism of circRNA endothelin converting enzyme 1 (circECE1) in osteosarcoma (OS) development is still not understood.

METHODS

The expression levels of circECE1, microRNA-588 (miR-588) and RAB3D, member RAS oncogene family (RAB3D) were gauged by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. OS cell proliferation was assessed by cell counting kit-8 (CCK-8) assay and 5-ethynyl-2'-deoxyuridine (EdU) assay. OS cell apoptosis rate and metastasis were identified by flow cytometry and transwell assay. Dual-luciferase reporter analysis and RNA immunoprecipitation (RIP) assay were performed to confirm the interactions among circECE1, miR-588 and RAB3D. Xenograft tumor models were established to explore circECE1 function in vivo. Immunohistochemistry (IHC) assay was applied to analyze RAB3D level after circECE1 knockdown.

RESULTS

In OS, circECE1 expression was higher than that in normal chondroma tissues. High levels of circECE1 were positively linked to OS cell viability, proliferation, migration and invasion, and negatively linked to OS cell apoptosis rate. It was found that circECE1 was a miR-588 sponge, and miR-588 inhibitor abrogated the influence of si-circECE1 on OS cells. MiR-588 targeted RAB3D to further regulate the pathological process of OS. Moreover, silencing circECE1 blocked OS tumor growth in vivo.

CONCLUSION

We elucidated the function of a novel circECE1/miR-588/RAB3D axis in OS progression.

The promising roles of exosomal microRNAs in osteosarcoma: A new insight into the clinical therapy

Osteosarcoma is the most common malignant bone sarcoma in children. Chemotherapy drugs resistance significantly hinders the overall survival of patients. Due to high biocompatibility and immunocompatibility, exosomes have been explored extensively. Multiple parent cells can actively secrete numerous exosomes, and the membrane structure of exosomes can protect miRNAs from degradation. Based on these characteristics, exosomal miRNAs play an important role in the occurrence, development, drug resistance. Therefore, in-depth exploration of exosome biogenesis and role of exosomal miRNAs will provide new strategies and targets for understanding the pathogenesis of osteosarcoma and overcoming chemotherapy drug resistance. Moreover, advancing evidences have showed that engineering modification could attribute stronger targeting to exosomes to deliver cargos to recipient cells more effectively. In this review, we focus on the mechanisms of exosomal miRNAs on the occurrence and development of osteosarcoma and the potential to function as tumor biomarkers for diagnosis and prognosis prediction. In addition, we also summarize recent advances in the clinical application values of engineering exosomes to provide novel ideas and directions for overcoming the chemotherapy resistance in osteosarcoma.

Circular RNA SLTM as a miR-421-competing endogenous RNA to mediate HMGB2 expression stimulates apoptosis and inflammation in arthritic chondrocytes

Osteoarthritis (OA) is the most common age-related joint disease characterized by chronic inflammation, progressive articular cartilage destruction, and subchondral sclerosis. Accumulating evidence suggests that circular RNAs (circRNAs) play key roles in OA, but the function of circSLTM in OA remains greatly unknown. Therefore, this study focused on interleukin-1β (IL-1β)-treated primary human chondrocytes as well as a rat model to investigate the expression pattern and functional role of circSLTM in OA in vitro and in vivo. CircSLTM and high mobility group protein B2 (HMGB2) were upregulated in IL-1β-induced chondrocytes, whereas miR-421 was downregulated. Knockdown of circSLTM or overexpression of miR-421 ameliorated IL-1β-induced chondrocyte apoptosis and inflammation. The regulatory relationship between circSLTM and miR-421, as well as that between miR-421 and HMGB2, was predicted by bioinformatics and then verified by the RNA immunoprecipitation experiment and dual-luciferase reporter gene assay. Furthermore, silencing of circSLTM increased cartilage destruction and decreased cartilage tissue apoptosis rate and inflammation in a rat model of OA. Taken together, our findings demonstrate the fundamental role of circSLTM in OA progression and provide a potential molecular target for OA therapy.

Long non-coding RNA KCNQ1OT1 alleviates postmenopausal osteoporosis by modulating miR-421-3p/mTOR axis

The prevention and treatment of postmenopausal osteoporosis (PMOP) is a significant public health issue, and non-coding RNAs are of vital importance in this process. In this study, we find that the long non-coding RNA potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (lncRNA KCNQ1OT1) can alleviate the ovariectomy-induced (OVX) PMOP in vivo. We determined that over-expression of KCNQ1OT1 could enhance functions of MC3T3-E1 cells, whereas an opposite trend was observed when KCNQ1OT1 was knocked down. Subsequently, miR-421-3p targeting KCNQ1OT1 was detected through a database search, and RNA fluorescent in situ hybridization, RNA immunoprecipitation, dual luciferase reporter assays all verified this relationship. Notably, KCNQ1OT1 stifled the miR-421-3p expression. The inhibition of proliferation, migration, and osteogenic differentiation caused by KCNQ1OT1 knock-down were reversed by an miR-421-3p inhibitor, further confirming the above findings. We verified that miR-421-3p specifically targeted the mammalian target of rapamycin (mTOR), and miR-421-3p inhibitor could reverse the negative effects of small interfering RNA of mTOR (si-mTOR) on MC3T3-E1 cells. Finally, osteoblasts isolated and cultured from OVX mice model and control mice also confirmed the observed trend. In combination, results mentioned above reveal that KCNQ1OT1 regulates MC3T3-E1 cell functions by regulating the miR-421-3p/mTOR axis.

MCPIP1 Suppresses the NF-κB Signaling Pathway Through Negative Regulation of K63-Linked Ubiquitylation of TRAF6 in Colorectal Cancer

The abnormal activation of the nuclear factor-kappa B (NF-κB) signaling pathway is an important precipitating factor for the inception and development of colorectal cancer (CRC), one of the most common tumors worldwide. As a pro-apoptotic transcription factor, monocyte chemotactic protein-induced protein 1 (MCPIP1) has been closely associated with many tumor types. In the present study, the expression of MCPIP1 was firstly discovered reduced in CRC tissues and correlated with poor patient prognosis. The decreased expression was caused by promoter hypermethylation. Overexpressed MCPIP1 was found to inhibit the proliferative and migratory abilities of CRC cells, whereas knockdown of MCPIP1 produced the opposite result. The subsequent investigation demonstrated that MCPIP1 exerted its "anti-cancer" effect by suppression of the NF-κB signaling pathway through negative regulation of K63-linked ubiquitylation of TNF receptor associated factor 6 (TRAF6). Therefore, our results indicate a prognostic marker for CRC and a theoretical basis for MCPIP1 as a treatment.

Long non-coding RNA NR2F2-AS1 regulates human osteosarcoma growth and metastasis through miR-425-5p-mediated HMGB2

BACKGROUND

Multiple studies have revealed that long non-coding RNA (lncRNA) NR2F2-AS1 plays a role in affecting cancer cell proliferation and metastasis. Here, both in vitro and in vivo experiments were performed for investigating the function and mechanism of NR2F2-AS1 in human osteosarcoma (OS).

METHODS

The NR2F2-AS1 level in human OS tissues and adjacent non-tumor tissues was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The NR2F2-AS1 overexpression model was constructed in OS cells, then cell proliferation, invasion, and apoptosis were monitored. The OS xenograft model was established in nude mice using NR2F2-AS1-overexpressed OS cells. The downstream target genes of NR2F2-AS1 were predicted. qRT-PCR and Western blot were implemented to validate the profiles of miR-425-5p and HMGB2. The targeting link between NR2F2-AS1 and miR-425-5p, miR-425-5p and HMGB2 was further probed by dual-luciferase reporter experiment.

RESULTS

In comparison to adjacent non-tumor tissues, OS tissues showed upregulated NR2F2-AS1 expression. Higher NR2F2-AS1 level was predominantly correlated with worse clinical stages. In vivo and in vitro tests corroborated that NR2F2-AS1 overexpression spurred OS cell proliferation, growth, invasion, and choked apoptosis. Mechanistically, NR2F2-AS1 hampered miR-425-5p expression as its competitive endogenous RNA (ceRNA). Thus, NR2F2-AS1 facilitated the HMGB2 expression. However, miR-425-5p inhibited HMGB2 expression by targeting the latter.

CONCLUSION

NR2F2-AS1 expedited the evolution of OS by elevating HMGB2 levels through sponging miR-425-5p. The NR2F2-AS1/miR-425-5p/HMGB2 regulatory axis is a promising target in treating human OS.

Cancer-associated fibroblast-secreted miR-421 promotes pancreatic cancer by regulating the SIRT3/H3K9Ac/HIF-1α axis

This study was designed to explore the effects of exosomal miR-421 secreted by cancer-associated fibroblasts (CAFs) on pancreatic cancer (PC) progression and the mechanisms involved. CAFs and exosomes (exos) were isolated and identified. PC cells were treated with CAF-derived exos (CAF-exos). Western blotting and quantitative polymerase chain reaction (qPCR) were used to measure miR-421, sirtuin-3 (SIRT3), and hypoxia duciblefactors-1 alpha (HIF-1α) levels. Cell counting kit-8 (CCK-8), wound-healing, and transwell migration assays were used to measure proliferation, migration, and invasion abilities of the cells. Dual-luciferase assay and RNA immunoprecipitation (RIP) experiment analyzed the relationship between miR-421 and SIRT3. Chromatin immunoprecipitation (f)-verified H3K9Ac enrichment in the HIF-1α promoter region. In vivo tumorigenesis experiments were performed to further explore the effects of exosomal miR-421 from CAFs on PC. CAFs and exos were successfully isolated. CAF-exo-treated PC cells highly expressed miR-421 and had increased cell proliferation, migration, and invasion abilities. Knocking down miR-421 increased the expression of SIRT3. SIRT3 is a target of miR-421, and inhibiting the expression of SIRT3 reversed the negative effects of miR-421 knockdown on PC cell. Knocking down miR-421 in CAF-exo inhibited the expression of HIF-1α in PC cells. Moreover, SIRT3-mediated HIF-1α expression by regulating H3K9Ac. HIF-1α overexpression reversed the inhibiting effects of SIRT3 overexpression on PC progression and counteracted the inhibiting effects of miR-421 knockdown on glycolysis. Moreover, in vivo tumorigenesis experiments showed that knocking down miR-421 attenuated CAF-exo induced tumor growth. Exosomal miR-421 from CAFs promoted PC progression by regulating the SIRT3/H3K9Ac/HIF-1α axis. This study provided insights into the molecular mechanism of PC.

Identification of Six N7-Methylguanosine-Related miRNA Signatures to Predict the Overall Survival and Immune Landscape of Triple-Negative Breast Cancer through In Silico Analysis

Triple-negative breast cancer (TNBC) is a widely prevalent breast cancer, with a mortality rate of up to 25%. TNBC has a lower survival rate, and the significance of N7-methylguanosine (m7G) modification in TNBC remains unclear. Thus, this study is aimed at investigating m7G-related miRNAs in TNBC patients through in silico analysis. In our research, RNA sequencing and clinical data were obtained from The Cancer Genome Atlas (TCGA) database. The miRNAs targeting typical m7G modification regulators Methyltransferase-like 1 (METTL1) and WD repeat domain 4 (WDR4) were predicted on the TargetScan website. A miRNA risk model was built, and its prognostic value was evaluated by R soft packages. Single-sample gene set enrichment analysis was used to assess immune infiltration, and further expression of immune checkpoints was investigated. As a result, miR-421, miR-5001-3p, miR-4326, miR-1915-3p, miR-3177-5p, and miR-4505 were identified to create the risk model. A nomogram consisting of the stage N and risk model predicted overall survival effectively among TNBC patients. Treg and TIL were shown to be strongly linked to the risk model, and the high-risk group had higher levels of four immune checkpoints expression (CD28, CTLA-4, ICOS, and TNFRSF9). A risk model consisting of m7G-related miRNAs was constructed. The findings of the current study could be used as a prognostic biomarker and can provide a novel immunotherapy insight for TNBC patients.

EZH2 promotes the progression of osteosarcoma through the activation of the AKT/GSK3β pathway

Enhancer of zeste homolog 2 (EZH2) is a clarified promoter in a list of tumors, including osteosarcoma (OS). Our research was projected to define the mechanism involved in EZH2-mediated OS progression through the protein kinase B (AKT)/glycogen synthase kinase 3β (GSK3β) pathway. EZH2 expression was tested in 66 OS tissues and 5 osteosarcoma cell lines (143B, SJSA-1, HOS, MG63, and U2OS). In HOS and U2OS cells, cellular malignant characteristics, and the markers of the AKT/GSK3β signaling pathway were measured when EZH2 was silenced or overexpressed. Meanwhile, rescue assays were implemented to observe whether the AKT/GSK3β signaling pathway inhibitor (MK-2206) could affect the role of overexpressed EZH2 in OS cells. EZH2 was up-regulated in tumor tissues of OS patients. OS cell lines (HOS and U2OS) showed impairments of proliferative, migratory, invasive and anti-apoptotic properties when EZH2 was silenced. Downregulated EZH2 inhibited the activation of the AKT/GSK3 signaling pathway. However, the situation in HOS and U2OS cells over-expressing EZH2 was opposite. MK-2206 erased EZH2 up-regulation-induced promotion of OS cell growth. It is demonstrated that EZH2 promotes the progression of OS via inducing the activation of the AKT/GSK3β pathway, offering a therapeutic direction for OS treatment.

Extracellular vesicles from bone mesenchymal stem cells transport microRNA-206 into osteosarcoma cells and target NRSN2 to block the ERK1/2-Bcl-xL signaling pathway

Osteosarcoma (OS) is a kind of malignant tumor originating from mesenchymal tissues. Bone mesenchymal stem cells-derived extracellular vesicles (BMSCs-EVs) can play important roles in OS. This study investigated the mechanism of BMSCs-EVs on OS. BMSC surface antigens and adipogenic and osteogenic differentiation were detected by flow cytometry, and oil red O and alizarin red staining. EVs were isolated from BMSCs by differential centrifugation and identified by transmission electron microscopy, nanoparticle tracking analysis, and Western blot (WB). miR-206 and neurensin-2 (NRSN2) levels in human osteoblast hFOB 1.19 or OS cells (143B, MG-63, Saos2, HOS) were detected by RT-qPCR. Human OS cells with lower miR-206 levels were selected and treated with BMSCs-EVs or pSUPER-NRSN2. The uptake of EVs by 143B cells, cell proliferation, apoptosis, invasion, and migration were detected by immunofluorescence, 5-ethynyl-2’-deoxyuridine (EdU) and colony formation assays, flow cytometry, scratch test, and transwell assays. The binding sites between miR-206 and NRSN2 were predicted by Starbase database and verified by dual-luciferase assay. The OS xenograft model was established and treated with BMSCs-EVs. Tumor growth rate and volume, cell proliferation, and p-ERK1/2, ERK1/2, and Bcl-xL levels were detected by vernier caliper, immunohistochemistry, and WB. BMSCs-EVs were successfully extracted. miR-206 was diminished and NRSN2 was promoted in OS cells. BMSCs-EVs inhibited proliferation, migration, and invasion, and promoted apoptosis of OS cells. BMSCs-EVs carried miR-206 into OS cells. Inhibition of miR-206 in EVs partially reversed the inhibitory effect of EVs on malignant behaviors of OS cells. miR-206 targeted NRSN2. Overexpression of NRSN2 reversed the inhibitory effect of EVs on OS cells. NRSN2 activated the ERK1/2-Bcl-xL pathway. BMSC-EVs inhibited OS growth in vivo. In summary, BMSC-EVs targeted NRSN2 and inhibited the ERK1/2-Bcl-xL pathway by carrying miR-206 into OS cells, thus inhibiting OS progression.

Plasma circRNA microarray profiling identifies novel circRNA biomarkers for the diagnosis of ovarian cancer

Background

Circular RNA (circRNA), a class of RNA with a covalent closed circular structure that widely existed in serum and plasma, has been considered an ideal liquid biopsy marker in many diseases. In this study, we employed microarray and qRT-PCR to evaluate the potential circulating circRNAs with diagnostic efficacy in ovarian cancer.

Methods

We used microarray to explore the circRNA expression profile in ovarian cancer patients’ plasma and quantitative real-time (qRT)-PCR approach to assessing the candidate circRNA’s expression. Then the receiver operating characteristic (ROC) curve was employed to analyze the diagnostic values of candidate circRNAs. The diagnostic model circCOMBO was a combination of hsa_circ_0003972 and hsa_circ_0007288 built by binary logistic regression. Then bioinformatic tools were used to predict their potential mechanisms.

Results

Hsa_circ_0003972 and hsa_circ_0007288 were downregulated in ovarian cancer patients’ plasma, tissues, and cell lines, comparing with the controls. Hsa_circ_0003972 and hsa_circ_0007288 exhibited diagnostic values with the Area Under Curve (AUC) of 0.724 and 0.790, respectively. circCOMBO showed a better diagnostic utility (AUC: 0.781), while the combination of circCOMBO and carbohydrate antigen 125 (CA125) showed the highest diagnostic value (AUC: 0.923). Furthermore, the higher expression level of hsa_circ_0007288 in both plasma and ovarian cancer tissues was associated with lower lymph node metastasis potential in ovarian cancer.

Conclusions

Our results revealed that hsa_circ_0003972 and hsa_circ_0007288 may serve as novel circulating biomarkers for ovarian cancer diagnosis.

Supplementary information

The online version contains supplementary material available at 10.1186/s13048-022-00988-0.

SPINKs in Tumors: Potential Therapeutic Targets

The serine protease inhibitor Kazal type (SPINK) family includes SPINK1-14 and is the largest branch in the serine protease inhibitor family. SPINKs play an important role in pancreatic physiology and disease, sperm maturation and capacitation, Nager syndrome, inflammation and the skin barrier. Evidence shows that the unregulated expression of SPINK1, 2, 4, 5, 6, 7, and 13 is closely related to human tumors. Different SPINKs exhibit various regulatory modes in different tumors and can be used as tumor prognostic markers. This article reviews the role of SPINK1, 2, 4, 5, 6, 7, and 13 in different human cancer processes and helps to identify new cancer treatment targets.

MiR-421 promotes lipid metabolism by targeting PTEN via activating PI3K/AKT/mTOR pathway in non-small cell lung cancer

Aims: We aim to investigate the effects of miR-421 on lipid metabolism in non-small cell lung cancer (NSCLC). Methods: The miR-421 expression and PTEN mRNA level in tumor tissues, adjacent normal tissues, human lung epithelial cells and NSCLC cell lines were detected with reverse transcription quantitative real-time PCR. Results: MiR-421 was increased, and PTEN was reduced remarkably in tumor tissues and NSCLC cell lines. Down-regulated miR-421 suppressed lipid accumulation, cell proliferation, migration and invasion, whereas overexpression of miR-421 had the opposite effects. MiR-421 directly targeted PTEN and negatively regulated PTEN expression. MiR-421 activated PI3K/AKT/mTOR pathway through regulating PTEN. Conclusion: MiR-421 promotes lipid metabolism through targeting PTEN via PI3K/AKT/mTOR pathway activation in NSCLC, indicating that miR-421 can be a latent therapeutic target for NSCLC.

Multifunctional RNase MCPIP1 and its Role in Cardiovascular Diseases

Monocyte chemoattractant protein-1 induced protein 1 (MCPIP1), one of the MCPIP family members, is characterized by the presence of both C-x8-C-x5-C-x3-H (CCCH)- type zinc finger and PilT-N-terminal domains. As a potent regulator of innate immunity, MCPIP1 exerts anti-inflammatory effects through its ribonuclease (RNase) and deubiquitinating enzyme activities to degrade cytokine mRNAs and inhibit nuclear factor- kappa B (NF-κB), respectively. MCPIP1 is expressed not only in immune cells but also in many other cell types, including cardiomyocytes, vascular endothelial cells (ECs) and smooth muscle cells (SMCs). Increasing evidence indicates that MCPIP1 plays a role in the regulation of cardiac functions and is involved in the processes of vascular diseases, such as ischemia-reperfusion (I/R) and atherosclerosis. To better understand the emerging roles of MCPIP1 in the cardiovascular system, we reviewed the current literature with respect to MCPIP1 functions and discussed its association with the pathogenesis of cardiovascular diseases and the implication as a therapeutic target.

Long non-coding RNA Rian protects against experimental bronchopulmonary dysplasia by sponging miR-421

Bronchopulmonary dysplasia (BPD) is a frequent complication characterized by accelerated lung alveolarization in newborns. Long non-coding RNAs (lncRNAs) and microRNAs (miRs) are regarded as essential regulators in various diseases, including BPD. However, the detailed mechanism of the functions of RNA imprinted and accumulated in nucleus (Rian) lncRNA in the progression of BPD have remained elusive. The aim of the present study was to illustrate the interaction between miR-421 and Rian in BPD models and MLE-12 cells. The ability of Rian to protect neonatal lungs from hyperoxia-induced lung damage was examined. A mouse model of BPD and a hyperoxia-stimulated MLE-12 cell damage model were generated and treated with specific plasmid/mimics for the overexpression of Rian/miR-421. The interaction between miR-421 and Rian was predicted and verified using StarBase and a dual-luciferase reporter assay, respectively. The expression levels of miR-421 or Rian in both tissues and the MLE-12 alveolar epithelial cell line were assessed using reverse transcription-quantitative (RT-q)PCR. As parameters of alveolarization, the mean linear intercept (MLI), radial alveolar count (RAC) and the lung weight/body weight (LW/BW) ratio were measured. Furthermore, RT-qPCR was used to measure mRNA levels of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) in the lung tissue of mice, and ELISAs were performed to determine the levels of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) in the supernatant of MLE-12 cells. Cell growth and apoptosis were evaluated using an MTT assay and flow cytometry, respectively. Furthermore, caspase-3 activity was assessed using a caspase-3 activity detection kit. Prediction with StarBase and the dual-luciferase reporter assay revealed that miR-421 directly targeted Rian. RT-qPCR analysis confirmed that Rian was downregulated and miR-421 was upregulated in lung tissues of the mouse model of BPD and in hyperoxia-induced MLE-12 cells. However, the expression of miR-421 was decreased by Rian-overexpression, an effect that was reversed by miR-421 mimics. In addition, BPD was alleviated by Rian-plasmid, as confirmed by the enhanced RAC and reduced MLI and LW/BW ratio. The present results also indicated that Rian-plasmid inhibited the secretion of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) in BPD mouse serum and hyperoxia-induced MLE-12 cells. In addition, Rian-plasmid eliminated the effect of hyperoxia to inhibit cell viability and induce apoptosis in MLE-12 cells. However, all of these effects of Rian were markedly reversed by miR-421 mimics. The present results indicated that Rian may attenuate hyperoxic damage in neonatal lungs and may serve as a novel molecular target for BPD treatment.

MCPIP1-mediated NFIC alternative splicing inhibits proliferation of triple-negative breast cancer via cyclin D1-Rb-E2F1 axis

Triple-negative breast cancer (TNBC) is the most aggressive subtype with the worst prognosis and the highest metastatic and recurrence potential, which represents 15–20% of all breast cancers in Chinese females, and the 5-year overall survival rate is about 80% in Chinese women. Recently, emerging evidence suggested that aberrant alternative splicing (AS) plays a crucial role in tumorigenesis and progression. AS is generally controlled by AS-associated RNA binding proteins (RBPs). Monocyte chemotactic protein induced protein 1 (MCPIP1), a zinc finger RBP, functions as a tumor suppressor in many cancers. Here, we showed that MCPIP1 was downregulated in 80 TNBC tissues and five TNBC cell lines compared to adjacent paracancerous tissues and one human immortalized breast epithelial cell line, while its high expression levels were associated with increased overall survival in TNBC patients. We demonstrated that MCPIP1 overexpression dramatically suppressed cell cycle progression and proliferation of TNBC cells in vitro and repressed tumor growth in vivo. Mechanistically, MCPIP1 was first demonstrated to act as a splicing factor to regulate AS in TNBC cells. Furthermore, we demonstrated that MCPIP1 modulated NFIC AS to promote CTF5 synthesis, which acted as a negative regulator in TNBC cells. Subsequently, we showed that CTF5 participated in MCPIP1-mediated antiproliferative effect by transcriptionally repressing cyclin D1 expression, as well as downregulating its downstream signaling targets p-Rb and E2F1. Conclusively, our findings provided novel insights into the anti-oncogenic mechanism of MCPIP1, suggesting that MCPIP1 could serve as an alternative treatment target in TNBC.

Circ_WWC3 overexpression decelerates the progression of osteosarcoma by regulating miR-421/PDE7B axis

Background

Emerging evidence has shown that circular RNAs (circRNAs) are vital regulators in osteosarcoma (OS) progression. However, the effects of circ_WWC3 in OS have not been explored. In this research, the functions and mechanisms of circ_WWC3 in OS were investigated.

Methods

Quantitative reverse trancription polymerase chain reaction (qRT-PCR) was adopted to determine the levels of circ_WWC3, WW and WWC3 mRNA, miR-421, and phosphodiesterase 7B (PDE7B) mRNA. RNase R assay was used to determine the characteristic of circ_WWC3. Colony formation assay and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay were applied for cell growth. Transwell assay was performed for cell migration and invasion. Flow cytometry analysis was utilized for cell apoptosis. Western blot assay was conducted for the levels of apoptosis-related proteins and PDE7B protein. Dual-luciferase reporter assay was carried out to analyze the targeting relationship between miR-421 and circ_WWC3 or PDE7B. The murine xenograft model was established to explore the effect of circ_WWC3 in vivo.

Results

Compared to normal tissues and cells, circ_WWC3 and PDE7B were downregulated in OS tissues and cells. Overexpression of circ_WWC3 or PDE7B suppressed OS cell growth, migration, and invasion and promoted apoptosis in vitro. Regarding the mechanism analysis, circ_WWC3 positively modulated PDE7B expression by targeting miR-421. MiR-421 overexpression restored the impacts of circ_WWC3 on OS cell growth, metastasis, and apoptosis. Inhibition of miR-421 repressed the malignant behaviors of OS cells by targeting PDE7B. In addition, circ_WWC3 inhibited the tumorigenicity of OS in vivo.

Conclusion

Circ_WWC3 overexpression slowed the development of OS by elevating PDE7B via sponging miR-421.

MCPIP1 expression positively correlates with melanoma-specific survival of patients, and its overexpression affects vital intracellular pathways of human melanoma cells

The suppressive activity of monocyte chemoattractant protein 1-induced protein 1 (MCPIP1) an inflammation-related ribonuclease, has been described in a few cancer types but has yet to be assessed in the most common subtype of skin cancer: melanoma. Here, we have evaluated the MCPIP1 expression in melanoma tissues by reanalysis of publicly available transcriptome data from 89 melanoma samples, and immunohistochemical staining of 21 primary and 81 metastatic melanomas. Our data implicated decreased MCPIP1 expression in melanoma tumors compared to normal tissues, and positive correlation between high ribonuclease expression and melanoma-specific survival of patients. To investigate the ribonuclease activity in melanoma cells, MCPIP1 was ectopically expressed in the MV3 human melanoma cell line. Following the transcriptome, proteome, and intracellular signaling of MCPIP1-overexpressing MV3 cells was assessed via real-time quantitative polymerase chain reaction, Western blot analysis, and RNAseq. MV3 cells overexpressing MCPIP1 exhibited a broad range of alterations in the transcriptome and proteome, as well as in the phosphorylation status of a number of proteins, strongly indicating MCPIP1-dependent cell cycle arrest and inhibition of Akt/mTOR signaling in these cells. Moreover, we have shown, that MCPIP1 overexpression downregulates miRNA-193a-3p expression in MV3 cells. Furthermore, the majority of the described effects were dependent on the ribonucleolytic activity of the protein. The presented body of data strongly suggests a potential tumor suppressor role and possible future application as a positive prognostic marker of MCPIP1 protein in melanoma.

MCPIP1 ribonuclease can bind and cleave AURKA mRNA in MYCN-amplified neuroblastoma cells

The role of the inflammation-silencing ribonuclease, MCPIP1 (monocyte chemoattractant protein-induced protein 1), in neoplasia continuous to emerge. The ribonuclease can cleave not only inflammation-related transcripts but also some microRNAs (miRNAs) and viral RNAs. The suppressive effect of the protein has been hitherto suggested in breast cancer, clear cell renal cell carcinoma, osteosarcoma, and neuroblastoma. Our previous results have demonstrated a reduced levels of several oncogenes, as well as inhibited growth of neuroblastoma cells upon MCPIP1 overexpression. Here, we investigate the mechanisms underlying the suppression of MYCN proto-oncogene, bHLH transcription factor (MYCN)-amplified neuroblastoma cells overexpressing the MCPIP1 protein. We showed that the levels of several transcripts involved in cell cycle progression decreased in BE(2)-C and KELLY cells overexpressing MCPIP1 in a ribonucleolytic activity-dependent manner. However, RNA immunoprecipitation indicated that only AURKA mRNA (encoding for Aurora A kinase) interacts with the ribonuclease. Furthermore, the application of a luciferase assay suggested MCPIP1-dependent destabilization of the transcript. Further analyses demonstrated that the entire conserved region of AURKA seems to be indispensable for the interaction with the MCPIP1 protein. Additionally, we examined the effect of the ribonuclease overexpression on the miRNA expression profile in MYCN-amplified neuroblastoma cells. However, no significant alterations were observed. Our data indicate a key role of the binding and cleavage of the AURKA transcript in an MCPIP1-dependent suppressive effect on neuroblastoma cells.

CircPVT1 Promoted the Progression of Breast Cancer by Regulating MiR-29a-3p-Mediated AGR2-HIF-1α Pathway

Background

Breast cancer (BC) is a great contributor to cancer-related death. Mounting studies have identified that circular RNAs (circRNAs) play vital roles in cancer cell proliferation, apoptosis and invasion. Here, we explored the effect of circPVT1 on BC development as well as its downstream mechanisms.

Methods

qRT-PCR was used to determine the relative expression levels of circPVT1 and miR-29a-3p in BC tissue samples and cell lines. We also analyzed the relevance between pathological indexes and circPVT1 expression level. Human breast cancer cell lines MCF-7 and MDA-MB-231 were taken as cell models. Gain- or loss-of-functional assays of circPVT1 and miR-29a-3p were conducted in BC cell lines to investigate their effects on the cell proliferation, apoptosis, migration and invasion. The protein levels of AGR2, HIF-1α, Bax, Bcl2 and Caspase3 were determined by Western blot. Furthermore, dual-luciferase reporter assay and RNA fluorescence in situ hybridization (FISH) were used to confirm the targeted relationships between circPVT1 and miR-29a-3p, miR-29a-3p and anterior gradient 2 (AGR2).

Results

CircPVT1 was highly expressed while miR-29a-3p was lowly expressed in BC tissues and cell lines. Inhibition of circPVT1 or overexpression of miR-29a-3p remarkably suppressed BC cell proliferation, invasion and migration while promoted cell apoptosis. By contrast, circPVT1 upregulation or miR-29a-3p inhibition led to mitigate malignant behaviours of BC cells. Functionally, circPVT1 bound to miR-29a-3p, and AGR2 was a target gene of miR-29a-3p. Overexpressed circPVT1 promoted AGR2 and HIF-1α expression by repressing miR-29a-3p. More importantly, overexpressing AGR2 enhances HIF-1α expression, accompanied with accelerated proliferation, invasion and migration of BC cells.

Conclusion

CircPVT1 acts as an oncogene in BC via promoting the growth, invasion, migration and inhibiting apoptosis through miR-29a-3p-mediated AGR2-HIF-1α axis.

Molecular Biology of Osteosarcoma

Osteosarcoma (OS) is the most frequent primary bone cancer in children and adolescents and the third most frequent in adults. Many inherited germline mutations are responsible for syndromes that predispose to osteosarcomas including Li Fraumeni syndrome, retinoblastoma syndrome, Werner syndrome, Bloom syndrome or Diamond-Blackfan anemia. TP53 is the most frequently altered gene in osteosarcoma. Among other genes mutated in more than 10% of OS cases, c-Myc plays a role in OS development and promotes cell invasion by activating MEK-ERK pathways. Several genomic studies showed frequent alterations in the RB gene in pediatric OS patients. Osteosarcoma driver mutations have been reported in NOTCH1, FOS, NF2, WIF1, BRCA2, APC, PTCH1 and PRKAR1A genes. Some miRNAs such as miR-21, -34a, -143, -148a, -195a, -199a-3p and -382 regulate the pathogenic activity of MAPK and PI3K/Akt-signaling pathways in osteosarcoma. CD133+ osteosarcoma cells have been shown to exhibit stem-like gene expression and can be tumor-initiating cells and play a role in metastasis and development of drug resistance. Although currently osteosarcoma treatment is based on adriamycin chemoregimens and surgery, there are several potential targeted therapies in development. First of all, activity and safety of cabozantinib in osteosarcoma were studied, as well as sorafenib and pazopanib. Finally, novel bifunctional molecules, of potential imaging and osteosarcoma targeting applications may be used in the future.

A novel microRNA signature for pathological grading in lung adenocarcinoma based on TCGA and GEO data

Lung adenocarcinoma (LUAD) is one of the most common types of lung cancer and its poor prognosis largely depends on the tumor pathological stage. Critical roles of microRNAs (miRNAs) have been reported in the tumorigenesis and progression of lung cancer. However, whether the differential expression pattern of miRNAs could be used to distinguish early-stage (stage I) from mid-late-stage (stages II–IV) LUAD tumors is still unclear. In this study, clinical information and miRNA expression profiles of patients with LUAD were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus databases. TCGA-LUAD (n=470) dataset was used for model training and validation, and the GSE62182 (n=94) and GSE83527 (n=36) datasets were used as external independent test datasets. The diagnostic model was created through miRNA feature selection followed by SVM classifier and was confirmed by 5-fold cross-validation. A receiver operating characteristic curve was calculated to evaluate the accuracy and robustness of the model. Using the DX score and LIBSVM tool, a 16-miRNA signature that could distinguish LUAD pathological stages was identified. The area under the curve rates were 0.62 [95% confidence interval (CI): 0.56–0.67], 0.66 (95% CI: 0.54–0.76) and 0.63 (95% CI: 0.43–0.82) in TCGA-LUAD internal validation dataset, the GSE62182 external validation dataset, and the GSE83527 external validation dataset, respectively. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses suggested that the target genes of the 16-miRNA signature were mainly involved in metabolic pathways. The present findings demonstrate that a 16-miRNA signature could serve as a promising diagnostic biomarker for pathological staging in LUAD.