MicroRNA‑643 regulates the expression of ZEB1 and inhibits tumorigenesis in osteosarcoma

Osteosarcoma and Metastasis

Osteosarcoma is the most common primary bone malignancy in adolescents. Its high propensity to metastasize is the leading cause for treatment failure and poor prognosis. Although the research of osteosarcoma has greatly expanded in the past decades, the knowledge and new therapy strategies targeting metastatic progression remain sparse. The prognosis of patients with metastasis is still unsatisfactory. There is resonating urgency for a thorough and deeper understanding of molecular mechanisms underlying osteosarcoma to develop innovative therapies targeting metastasis. Toward the goal of elaborating the characteristics and biological behavior of metastatic osteosarcoma, it is essential to combine the diverse investigations that are performed at molecular, cellular, and animal levels from basic research to clinical translation spanning chemical, physical sciences, and biology. This review focuses on the metastatic process, regulatory networks involving key molecules and signaling pathways, the role of microenvironment, osteoclast, angiogenesis, metabolism, immunity, and noncoding RNAs in osteosarcoma metastasis. The aim of this review is to provide an overview of current research advances, with the hope to discovery druggable targets and promising therapy strategies for osteosarcoma metastasis and thus to overcome this clinical impasse.

CircLPAR3 Acts as an Oncogene in Oral Squamous Cell Carcinoma Through Regulating the miR-643/HMGB2 Network

The malignant progression of oral squamous cell carcinoma (OSCC) has been confirmed to be mediated by a variety of factors, including circular RNA (circRNA). However, the role of circLPAR3 in OSCC development is still unclear. 70 paired OSCC tissues and normal control tissues were obtained from 70 OSCC patients. Quantitative real-time PCR was used to detect the expression of circLPAR3, microRNA (miR)-643, and high-mobility group box 2 (HMGB2). Cell proliferation, apoptosis, metastasis and stemness were assessed using cell counting kit 8 assay, colony-formation assay, flow cytometry, transwell assay and sphere formation assay. Marker protein expression and HMGB2 protein expression were determined by western blot analysis. The interaction between miR-643 and circLPAR3 or HMGB2 was confirmed by RNA pull-down assay, dual-luciferase reporter and RIP assay. The role of circLPAR3 in OSCC tumorigenesis was explored by constructing the xenograft models. Our data showed that circLPAR3 was highly expressed in OSCC tissues and cells. CircLPAR3 silencing suppressed OSCC cell proliferation, metastasis and stemness, while promoted apoptosis. On the mechanism, we discovered that circLPAR3 could sponge miR-643 to positive regulate HMGB2. MiR-643 overexpression had an inhibition effect on OSCC progression, and its inhibitor could reverse the negative regulation of circLPAR3 knockdown on OSCC progression. In addition, overexpressed HMGB2 also reversed the suppressive effect of circLPAR3 silencing on OSCC progression. Animal experiments results showed that downregulated circLPAR3 repressed OSCC tumorigenesis in vivo. Taken together, our data showed that circLPAR3 contributed to OSCC malignant progression through regulating the miR-643/HMGB2 axis.

CircRNA circFADS2 is Downregulated in Endometritis and its Overexpression Promotes miR-643 Maturation in Human Endometrial Epithelial Cells to Suppress Cell Apoptosis

CircRNA circFADS2 suppresses LPS-induced inflammation, which plays a critical role in endometritis. Our preliminary sequencing analysis revealed a positive correlation between circFADS2 and miR-643, which also play protective roles in LPS-induced inflammation. Therefore, this study was performed to explore the involvement of circFADS2 in endometritis with a focus on its interaction with miR-643. RT-qPCR was performed to analyze the levels circFADS2, mature miR-643, and premature miR-643 in plasma samples from endometritis patients (n = 66) and healthy controls (n = 66). Pearson's correlation coefficient was applied to analyze correlations between these genes. The effect of circFADS2 on miR-643 maturation was analyzed by measuring miR-643 and premature miR-643 levels in circFADS2-overexpressed human endometrial epithelial cell line HEnEpCs. The role of circFADS2 and miR-643 in HEnEpC apoptosis under LPS treatment was analyzed by cell apoptosis assay. CircFADS2 was downregulated in endometritis and was positively correlated with mature miR-643, but not premature miR-643. CircFADS2 overexpression in HEnEpCs increased the level of mature miR-643 but not premature miR-643. Cell apoptosis analysis showed that circFADS2 and miR-643 overexpression protected HEnEpCs from LPS-induced cell apoptosis, and miR-643 inhibition reduced the effect of circFADS2 overexpression. CircFADS2 is downregulated in endometritis, and it overexpression promotes miR-643 maturation in HEnEpCs to suppress cell apoptosis.

Oncogenic functions of ZEB1 in pediatric solid cancers: interplays with microRNAs and long noncoding RNAs

The transcription factor Zinc finger E-box binding 1 (ZEB1) displays a range of regulatory activities in cell function and embryonic development, including driving epithelial-mesenchymal transition. Several aspects of ZEB1 function can be regulated by its functional interactions with noncoding RNA types, namely microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). Increasing evidence indicates that ZEB1 importantly influences cancer initiation, tumor progression, metastasis, and resistance to treatment. Cancer is the main disease-related cause of death in children and adolescents. Although the role of ZEB1 in pediatric cancer is still poorly understood, emerging findings have shown that it is expressed and regulates childhood solid tumors including osteosarcoma, retinoblastoma, neuroblastoma, and central nervous system tumors. Here, we review the evidence supporting a role for ZEB1, and its interplays with miRNAs and lncRNAs, in pediatric cancers.

Horizontal Transfer of miR-643 from Cisplatin-Resistant Cells Confers Chemoresistance to Recipient Drug-Sensitive Cells by Targeting APOL6

Acquisition of resistance to cisplatin is a major impediment to the success of cisplatin-based combination therapies for cancer. Recent studies indicate that exosomal miRNAs derived from drug-resistant tumour cells can confer resistance properties to recipient cells by a horizontal transfer mechanism. Although the role of horizontal transfer of a few miRNAs has been described, little is known about the concerted action of horizontal transfer of miRNAs in conferring cisplatin resistance. The present study was designed to identify the role of miR-643, which is one of the most significantly increased miRNA in exosomes released from cisplatin-resistant Heptocarcinoma cells, in altering the cisplatin resistance properties of recipient cells. Drug-sensitivity assays involving miR-643 revealed that ectopic expression of miR-643 can desensitise the cells towards cisplatin. Furthermore, we identified APOL6 as a major target of miR-643. Further mechanistic studies showed that miR-643 can modulate APOL6 mRNA and protein levels, leading to a reversal of APOL6-mediated apoptosis. Altogether, our results suggest an APOL6-dependent mechanism for miR-643 mediated cisplatin resistance upon the horizontal transfer across cell types.

The EMT transcription factor ZEB1 blocks osteoblastic differentiation in bone development and osteosarcoma

Osteosarcoma is an often-fatal mesenchyme-derived malignancy in children and young adults. Overexpression of EMT-transcription factors (EMT-TFs) has been associated with poor clinical outcome. Here, we demonstrated that the EMT-TF ZEB1 is able to block osteoblastic differentiation in normal bone development as well as in osteosarcoma cells. Consequently, overexpression of ZEB1 in osteosarcoma characterizes poorly differentiated, highly metastatic subgroups and its depletion induces differentiation of osteosarcoma cells. Overexpression of ZEB1 in osteosarcoma is frequently associated with silencing of the imprinted DLK-DIO3 locus, which encodes for microRNAs targeting ZEB1. Epigenetic reactivation of this locus in osteosarcoma cells reduces ZEB1 expression, induces differentiation, and sensitizes to standard treatment, thus indicating therapeutic options for ZEB1-driven osteosarcomas. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

MicroRNAome: Potential and Veritable Immunomolecular Therapeutic and Diagnostic Baseline for Lingering Bovine Endometritis

The bovine endometrium is a natural pathogen invasion barrier of the uterine tissues' endometrial epithelial cells that can resist foreign pathogen invasion by controlling the inflammatory immune response. Some pathogens suppress the innate immune system of the endometrium, leading to prolonged systemic inflammatory response through the blood circulation or cellular degradation resulting in bovine endometritis by bacterial endotoxins. The microRNA (miRNA) typically involves gene expression in multicellular organisms in post-transcription regulation by affecting both the stability and the translation of messenger RNA. Accumulated evidence suggests that miRNAs are important regulators of genes in several cellular processes. They are a class of endogenous non-coding RNAs, which play pivotal roles in the inflammatory response of reproductive diseases. Studies confirmed that miRNAs play a key regulatory role in various inflammatory diseases by mediating the molecular mechanism of inflammatory cytokines via signal pathways. It implicates some miRNAs in the occurrence of bovine endometritis, resorting to regulating the activities of some inflammatory cytokines, chemokine, differentially expressed genes, and protein through modulating of specific cellular signal pathways functions. This review dwells on improving the knowledge of the role of miRNAs involvement in inflammatory response as to early diagnosis, control, and prevention of bovine endometritis and consequently enlighten on the molecular improvement of the genes coded by various differentially expressed miRNA through the need to adopt recent genetic technologies and the development of new pharmaceutical preparations.

Comprehensive circular RNA expression profiling constructs a ceRNA network and identifies hsa_circ_0000673 as a novel oncogene in distal cholangiocarcinoma

Circular RNAs (circRNAs) play an important role in cholangiocarcinoma (CCA) development; however, the expression and functions of circRNAs in distal CCA (dCCA) remain unknown. Herein, we explored the expression profile of circRNAs in six paired dCCA tumor and adjacent normal tissue samples using microarray. A total of 171 differentially expressed (DE) circRNAs were identified in dCCA tissues. Host genes of DE circRNAs were enriched in the cellular cytoskeleton and adheren junction. Bioinformatics analyses were used to establish a circRNA-microRNA-mRNA network for dCCA. Protein-protein interaction networks were constructed, and five hub genes were associated with the regulation of the cell cycle based on gene set enrichment analyses. Five DE circRNAs were validated with qRT-PCR in 40 pairs of dCCA tissues, and hsa_circ_0000673 showed promising diagnostic performance in distinguishing dCCA from normal tissues (AUC = 0.85, p < 0.01). Overexpression of hsa_circ_0000673 was associated with tumor invasion (p = 0.001), poor differentiation (p = 0.041), and residual tumor (p = 0.044). In vitro experiments indicated that inhibition of hsa_circ_0000673 suppressed the proliferation, migration, and invasion of CCA cells. This research provided a landscape of dysregulated circRNAs in dCCA and identified hsa_circ_0000673 as a potential biomarker and therapeutic target for dCCA.

MiR-643 inhibits lipopolysaccharide-induced endometritis progression by targeting TRAF6

Endometritis is a prevalent disease with inflammation of uterus endangering women reproductive health. MicroRNAs (miRNAs) play important roles in inflammatory disorders, including endometritis. However, the role and mechanism of miR-643 in endometritis development remain unclear. This study aimed to investigate the effect of miR-643 on lipopolysaccharide (LPS)-induced inflammatory response and clarify the potential mechanism. LPS-treated human endometrial epithelial cells (HEECs) were cultured to investigate the role of miR-643 in vitro. The expression levels of miR-643 and tumor necrosis factor receptor-associated factor 6 (TRAF6) were measured via quantitative real-time polymerase chain reaction and western blot, respectively. LPS-induced inflammatory response was assessed by inflammatory cytokines secretion via enzyme-linked immunosorbent assay. The activation of nuclear factor-κB (NF-κB) pathway was investigated by western blot. The interaction between miR-643 and TRAF6 was validated by bioinformatics analysis, luciferase reporter assay, and RNA immunoprecipitation. The expression of miR-643 was decreased and TRAF6 protein level was enhanced in LPS-treated HEECs. The overexpression of miR-643 suppressed LPS-induced secretion of inflammatory cytokines (tumor necrosis factor-α, interleukin-1β [IL-1β], and IL-6) and activation of NF-κB pathway. The knockdown of TRAF6 inhibited LPS-induced inflammatory response in HEECs. TRAF6 was validated as a target of miR-643 and TRAF6 restoration reversed the effect of miR-643 on inflammation response in LPS-treated HEECs. Collectively, miR-643 attenuated LPS-induced inflammatory response by targeting TRAF6, indicating a novel avenue for the treatment of endometritis.

Naringin targets Zeb1 to suppress osteosarcoma cell proliferation and metastasis

Naringin, a citrus bioflavonoid, has anti-inflammatory actions and cardio- and neuroprotective effects. In addition, naringin exhibits multiple antitumor actions in several cancer types, including osteosarcoma, the most common type of bone cancer. Here, we show that naringin inhibits proliferation and invasion and induces apoptosis in human osteosarcoma cells by inhibiting zinc finger E-box binding homeobox 1 (Zeb1), a transcriptional repressor of epithelial differentiation involved in tumor metastasis. Our expression analyses confirm that Zeb1 is highly expressed in osteosarcoma specimens and cell lines. The effects of naringin, which included downregulation of Cyclin D1, MMP2, and bcl-2, where reproduced by siRNA-mediated Zeb1 silencing, whereas Zeb1 overexpression increased proliferation, migration, and Cyclin D1, MMP2, and bcl-2 levels. In addition, naringin administration reduced tumor nodule formation and attenuated the expression of the above proteins in the livers of mice injected with MG63 osteosarcoma cells. Our study provides preclinical evidence for the potential therapeutic application of naringin in the treatment of osteosarcoma.

miRNA signatures in childhood sarcomas and their clinical implications

Progresses in multimodal treatments have significantly improved the outcomes for childhood cancer. Nonetheless, for about one-third of patients with Ewing sarcoma, rhabdomyosarcoma, or osteosarcoma steady remission has remained intangible. Thus, new biomarkers to improve early diagnosis and the development of precision-targeted medicine remain imperative. Over the last decade, remarkable progress has been made in the basic understanding of miRNAs function and in interpreting the contribution of their dysregulation to cancer development and progression. On this basis, this review focuses on what has been learned about the pivotal roles of miRNAs in the regulation of key genes implicated in childhood sarcomas.

MicroRNA‑708 inhibits the proliferation and invasion of osteosarcoma cells by directly targeting ZEB1

Numerous microRNAs (miRNAs) have been identified as aberrantly expressed in osteosarcoma (OS). miRNAs serve important roles in the pathogenesis of OS as oncogenes or tumor suppressors. Recent studies revealed that miR‑708‑5p (miR‑708) was dysregulated in various types of human cancer; however, its roles and underlying molecular mechanisms in OS remain unknown. Therefore, the present study aimed to determine miR‑708 expression in OS, investigate the roles of miR‑708 in the progression of OS and reveal the potential mechanisms involved. It was demonstrated using reverse transcription‑polymerase chain reaction that miR‑708 was downregulated in OS tissues and cell lines. Cell Counting Kit‑8 and Transwell assays revealed that miR‑708 overexpression suppressed the proliferation and invasion of OS cells in vitro. Additionally, zinc finger E‑box binding homeobox 1 (ZEB1) was validated as a direct target gene of miR‑708 in OS cells. ZEB1 was upregulated in OS tissues; elevated ZEB1 expression was negatively correlated with the levels of miR‑708 expression. Rescue experiments indicated that ZEB1 reintroduction significantly counteracted the inhibitory effects of miR‑708 overexpression on the proliferation and invasion of OS cells. The findings may improve understanding of the roles of miR‑708 in the development of OS, and suggest that miR‑708 may be a potential novel therapeutic target in the treatment of patients with this disease.

Entamoeba histolytica Up-Regulates MicroRNA-643 to Promote Apoptosis by Targeting XIAP in Human Epithelial Colon Cells

MicroRNAs (miRNAs) are small non-coding RNAs that function as negative regulators of gene expression. Recent evidences suggested that host cells miRNAs are involved in the progression of infectious diseases, but its role in amoebiasis remains largely unknown. Here, we reported an unexplored role for miRNAs of human epithelial colon cells during the apoptosis induced by Entamoeba histolytica. We demonstrated for the first time that SW-480 colon cells change their miRNAs profile in response to parasite exposure. Our data showed that virulent E. histolytica trophozoites induced apoptosis of SW-480 colon cells after 45 min interaction, which was associated to caspases-3 and -9 activation. Comprehensive profiling of 667 miRNAs using Taqman Low-Density Arrays showed that 6 and 15 miRNAs were significantly (FC > 1.5; p < 0.05) modulated in SW-480 cells after 45 and 75 min interaction with parasites, respectively. Remarkably, no significant regulation of the 6-miRNAs signature (miR-526b-5p, miR-150, miR-643, miR-615-5p, miR-525, and miR-409-3p) was found when SW-480 cells were exposed to non-virulent Entamoeba dispar. Moreover, we confirmed that miR-150, miR-643, miR-615-5p, and miR-525 exhibited similar regulation in SW-480 and Caco2 colon cells after 45 min interaction with trophozoites. Exhaustive bioinformatic analysis of the six-miRNAs signature revealed intricate miRNAs-mRNAs co-regulation networks in which the anti-apoptotic XIAP, API5, BCL2, and AKT1 genes were the major targets of the set of six-miRNAs. Of these, we focused in the study of functional relationships between miR-643, upregulated at 45 min interaction, and its predicted target X-linked inhibitor of apoptosis protein (XIAP). Interestingly, interplay of amoeba with SW-480 cells resulted in downregulation of XIAP consistent with apoptosis activation. More importantly, loss of function studies using antagomiRs showed that forced inhibition of miR-643 leads to restoration of XIAP levels and suppression of both apoptosis and caspases-3 and -9 activation. Congruently, mechanistic studies using luciferase reporter assays confirmed that miR-643 exerts a postranscripcional negative regulation of XIAP by targeting its 3′-UTR indicating that it's a downstream effector. In summary, we provide novel lines of evidence suggesting that early-branched eukaryote E. histolytica may promote apoptosis of human colon cells by modulating, in part, the host microRNome which highlight an unexpected role for miRNA-643/XIAP axis in the host cellular response to parasites infection.

MicroRNA-466 inhibits osteosarcoma cell proliferation and induces apoptosis by targeting CCND1

Emerging pieces of evidence indicate that microRNA-466 (miR-466) serves as a tumor suppressor in several human tumors, including colorectal cancer and prostate cancer. However, whether miR-466 is involved in osteosarcoma (OS) progression remains largely unknown. The present study demonstrated that miR-466 was significantly downregulated in OS tissues and cell lines. Furthermore, it was revealed that the expression of miR-466 was negatively correlated with OS severity. Moreover, low miR-466 expression in patients with OS predicted poor prognosis. Through functional experiments, miR-466 overexpression significantly inhibited the proliferation and cell cycle of OS cells while inducing cellular apoptosis. In terms of mechanism, it was revealed that CCND1 was a target of miR-466 in OS cells. miR-466 overexpression suppressed CCND1 expression in OS cells. A reverse association was observed between the expression levels of miR-466 and CCND1 in OS tissues. Furthermore, CCND1 restoration in OS cells significantly rescued the effects of miR-466 on cellular proliferation and apoptosis. Overall, the results of the present study demonstrated that miR-466 suppressed OS progression by targeting CCND1, suggesting that miR-466 may be a promising biomarker and therapeutic target for OS prognosis and treatment.

MiR-28-5p relieves neuropathic pain by targeting Zeb1 in CCI rat models

MicroRNAs (miRNAs) are recognized as significant regulators of neuropathic pain. Moreover, neuroinflammation can contribute a lot to the progression of neuropathic pain. MiR-28-5p has been reported to be involved in many pathological diseases. However, little is known about the function of miR-28-5p in neuropathic pain development. Our current study was designed to investigate the biological roles of miR-28-5p in neuropathic pain in a rat model established by chronic sciatic nerve injury (CCI). Here, we observed that miR-28-5p was decreased in CCI rats. MiR-28-5p overexpression was able to alleviate neuropathic pain behaviors including mechanical and thermal hyperalgesia. Meanwhile, inflammation-correlated biomarkers such as Cyclooxygenase 2 (Cox-2), interleukin-6 (IL-6), and IL-1β were greatly promoted in CCI rats and they were inhibited by miR-28-5p upregulation. In addition, zinc finger E-box-binding homeobox 1 (Zeb1) is a kind of transcription factor that is involved in various diseases. Here, in our study, Zeb1 was predicted as a downstream target of miR-28-5p. miR-28-5p can bind with the 3'-untranslated region of Zeb1, which was validated by carrying out dual-luciferase reporter assay. Moreover, we found that Zeb1 was significantly increased in CCI rats and miR-28-5p can modulate Zeb1 expression negatively. Theoverexpression of Zeb1 can disturb neuropathic pain development, which was repressed by the increase of miR-28-5p by upregulating Cox-2, IL-6, and IL-1β levels. By taking all of these together, it was indicated in our study that miR-28-5p can reduce neuropathic pain progression by targeting Zeb1 in vivo. Our data implied that miR-28-5p/Zeb1 axis can be a novel therapeutic target for neuropathic pain treatment.

IGFBP2 promotes salivary adenoid cystic carcinoma metastasis by activating the NF-κB/ZEB1 signaling pathway

Metastasis is a major cause of poor prognosis in patients suffered with salivary adenoid cystic carcinoma (SACC), in which many factors are implicated. In this study, we identified that IGFBP2, overexpressed in SACC, correlated positively with perineural invasion or metastasis and indicated worse outcome. Moreover, IGFBP2 overexpression could dramatically improve motility and invasion capacity of SACC cells in vitro. Mechanically, IGFBP2 enhanced expression of ZEB1 in a NF-κB (p65)-dependent manner and then promoted epithelial-mesenchymal transition (EMT) in SACC. In addition, IGFBP2 mutation in the nuclear localization signal could impede nuclear translocation of p65, lower ZEB1 expression, and abrogate the EMT process. In xenograft models, IGFBP2 overexpression promoted lung and liver metastases of SACC cells; while if nuclear IGFBP2 was reduced, the formation of metastases in lung and liver was weakened. Together, these results for the first time demonstrate that IGFBP2 plays an important role in invasion and metastasis of SACC through the NF-κB/ZEB1 signaling pathway and IGFBP2 may be a novel biomarker and target for SACC.