Regulatory roles and therapeutic potential of microRNA in sarcoma

MicroRNAs and angiosarcoma: are there promising reports?

In recent years, microRNAs (miRNAs) have garnered increasing attention for their potential implications in cancer pathogenesis, functioning either as oncogenes or tumor suppressors. Notably, angiosarcoma, along with various other cardiovascular tumors such as lipomas, rhabdomyomas, hemangiomas, and myxomas, has shown variations in the expression of specific miRNA subtypes. A substantial body of evidence underscores the pivotal involvement of miRNAs in the genesis of angiosarcoma and certain cardiovascular tumors. This review aims to delve into the current literature on miRNAs and their prospective applications in cardiovascular malignancies, with a specific focus on angiosarcoma. It comprehensively covers diagnostic methods, prognostic evaluations, and potential treatments while providing a recapitulation of angiosarcoma's risk factors and molecular pathogenesis, with an emphasis on the role of miRNAs. These insights can serve as the groundwork for designing randomized control trials, ultimately facilitating the translation of these findings into clinical applications. Moving forward, it is imperative for studies to thoroughly scrutinize the advantages and disadvantages of miRNAs compared to current diagnostic and prognostic approaches in angiosarcoma and other cardiovascular tumors. Closing these knowledge gaps will be crucial for harnessing the full potential of miRNAs in the realm of angiosarcoma and cardiovascular tumor research.

MiR-130b modulates the invasive, migratory, and metastatic behavior of leiomyosarcoma

Leiomyosarcoma (LMS) is an aggressive, often poorly differentiated cancer of the smooth muscle (SM) lineage for which the molecular drivers of transformation and progression are poorly understood. In microRNA (miRNA) profiling studies, miR-130b was previously found to be upregulated in LMS vs. normal SM, and down-regulated during the differentiation of mesenchymal stem cells (MSCs) into SM, suggesting a role in LMS tumor progression. In the present study, the effects of miR-130b on human LMS tumorigenesis were investigated. Stable miR-130b overexpression enhanced invasion of LMS cells in vitro, and led to the formation of undifferentiated, pleomorphic tumors in vivo, with increased growth and metastatic potential compared to control LMS cells. TSC1 was identified as a direct miR-130b target in luciferase-3'UTR assays, and shRNA-mediated knockdown of TSC1 replicated miR-130b effects. Loss-of-function and gain-of-function studies showed that miR-130b levels regulate cell morphology and motility. Following miR-130b suppression, LMS cells adopted a rounded morphology, amoeboid mode of cell movement and enhanced invasive capacity that was Rho/ROCK dependent. Conversely, miR-130b-overexpressing LMS cells exhibited Rho-independent invasion, accompanied by down-regulation of Rho-pathway effectors. In mesenchymal stem cells, both miR-130b overexpression and TSC1 silencing independently impaired SM differentiation in vitro. Together, the data reveal miR-130b as a pro-oncogenic miRNA in LMS and support a miR-130b-TSC1 regulatory network that enhances tumor progression via inhibition of SM differentiation.

miR-511 Deficiency Protects Mice from Experimental Colitis by Reducing TLR3 and TLR4 Responses via WD Repeat and FYVE-Domain-Containing Protein 1

Antimicrobial responses play an important role in maintaining intestinal heath. Recently we reported that miR-511 may regulate TLR4 responses leading to enhanced intestinal inflammation. However, the exact mechanism remained unclear. In this study we investigated the effect of miR-511 deficiency on anti-microbial responses and DSS-induced intestinal inflammation. miR-511-deficient mice were protected from DSS-induced colitis as shown by significantly lower disease activity index, weight loss and histology scores in the miR-511-deficient group. Furthermore, reduced inflammatory cytokine responses were observed in colons of miR-511 deficient mice. In vitro studies with bone marrow-derived M2 macrophages showed reduced TLR3 and TLR4 responses in miR-511-deficient macrophages compared to WT macrophages. Subsequent RNA sequencing revealed Wdfy1 as the potential miR-511 target. WDFY1 deficiency is related to impaired TLR3/TLR4 immune responses and the expression was downregulated in miR-511-deficient macrophages and colons. Together, this study shows that miR-511 is involved in the regulation of intestinal inflammation through downstream regulation of TLR3 and TLR4 responses via Wdfy1.

MicroRNA-3148 acts as molecular switch promoting malignant transformation and adipocytic differentiation of immortalized human bone marrow stromal cells via direct targeting of the SMAD2/TGFβ pathway

MicroRNAs (miRs/miRNAs) play a key role in posttranscriptional regulation of gene expression and are implicated in a number of physiological and pathological conditions, including cellular malignant transformation. In the current study, we investigated the role of miR-3148 in regulating human stromal (mesenchymal) stem cell (hMSC) differentiation and transformation. Stable expression of miR-3148 in telomerized hMSC (hMSC-miR-3148) led to significant increase in in vitro adipocytic differentiation and suppression of osteoblastic differentiation. Concordantly, global gene expression profiling revealed significant enrichment in cholesterol biosynthesis pathway, and pathways related to enhanced cell movement and survival, whereas processes related to bone and connective tissue developments, cell death, apoptosis, and necrosis were downregulated. Global proteomic analysis using 2D-DIGE followed by mass spectrometry (MS) revealed significant changes in protein expression in hMSC-miR-3148 and enrichment in protein networks associated with carcinogenesis. Functional studies revealed that hMSC-miR-3148 exhibited enhanced in vitro cell proliferation, colony formation, migration, invasion, sphere formation, doxorubicin resistance, and increased active number of cells in S and G2/M cell cycle phases and formed sarcoma-like tumors with adipocyte infiltration when implanted into immunocompromised mice. SMAD2 was identified as bone fide gene target for miR-3148 using qRT-PCR, Western blotting, and UTR-based reporter assay. In agreement with our data, SMAD2 expression was downregulated in 47% of patients with soft tissue sarcoma. Bioinformatics analysis revealed that elevated miR-3148 expression correlates with poor prognosis in several human cancer types, including sarcoma. Our study identified miR-3148 as factor regulating hMSC differentiation and is involved in promoting malignant transformation of telomerized hMSC.

Knockdown of TBRG4 suppresses proliferation, invasion and promotes apoptosis of osteosarcoma cells by downregulating TGF-β1 expression and PI3K/AKT signaling pathway

Transforming growth factor beta regulator 4 (TBRG4) is a novel regulator in tumorigenic progression of several tumors. However, so far, the expression and functions of TBRG4 in osteosarcoma are unknown. The aim of this study was to investigate the potential biological functions of TBRG4 in osteosarcoma. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of TBRG4 in osteosarcoma tissues and cell lines. The levels of TBRG4 protein in osteosarcoma tissues were assessed by immunohistochemistry. Lentivirus-mediated short hairpin (sh) RNA was employed to knock down TBRG4 in osteosarcoma cells, and the expressions of TBRG4 mRNA and protein were determined by qRT-PCR and Western blot assay, respectively. Subsequently, the proliferation, clonogenic ability, apoptosis and invasion of osteosarcoma cells were measured using high content screening analysis and CCK8 assay, tumor sphere formation assay, flow cytometry and Transwell invasion assays, respectively. Furthermore, the osteosarcoma cells growth and metastasis in vivo were detected, and the effect of TBRG4 on the transforming growth factor β1 (TGF-β1) and PI3K/AKT signaling pathway was explored by qRT-PCR and Western blot assay, respectively. The results showed the levels of TBRG4 were overexpressed in osteosarcoma tissues and cell lines, confirming that the high TBRG4 expression was related to advanced tumor stages, large tumor size, and lymph node metastasis. Functional assays showed knockdown of TBRG4 could inhibit proliferation, invasion and induce apoptosis of osteosarcoma cells in vitro, and could also suppress osteosarcoma growth and metastasis in vivo. By examining the expression levels of TGF-β1, p-PI3K, PI3K, p-AKT and AKT, it showed that the suppression of TBRG4 would reduce TGF-β1 expression and inactivate the PI3K/AKT signaling pathway. These results showed for the first time that TBRG4 knockdown could suppress osteosarcoma progression, suggesting TBRG4 might be a promising therapeutic target for osteosarcoma treatment.

Risk score based on expression of five novel genes predicts survival in soft tissue sarcoma

In this study, The Cancer Genome Atlas and Genotype-Tissue Expression databases were used to identify potential biomarkers of soft tissue sarcoma (STS) and construct a prognostic model. The model was used to calculate risk scores based on the expression of five key genes, among which MYBL2 and FBN2 were upregulated and TSPAN7, GCSH, and DDX39B were downregulated in STS patients. We also examined gene signatures associated with the key genes and evaluated the model’s clinical utility. The key genes were found to be involved in the cell cycle, DNA replication, and various cancer pathways, and gene alterations were associated with a poor prognosis. According to the prognostic model, risk scores negatively correlated with infiltration of six types of immune cells. Furthermore, age, margin status, presence of metastasis, and risk score were independent prognostic factors for STS patients. A nomogram that incorporated the risk score and other independent prognostic factors accurately predicted survival in STS patients. These findings may help to improve prognostic prediction and aid in the identification of effective treatments for STS patients.

MiR-125b suppresses the carcinogenesis of osteosarcoma cells via the MAPK-STAT3 pathway

The microRNA (miRNA) miR-125b is abnormally expressed in many different types of tumors, including osteosarcoma (OS). How aberrantly expressed miR-125b participates in regulating the initiation and progression of OS is still poorly understood. In the current study, we found that in OS, miR-125b can suppress the expression of MAP kinase kinase 7 (MKK7), which can dephosphorylate and inactivate signal transducer and activator of transcription 3 (STAT3). We also identified an elevated expression level of MKK7 in OS and an association between MKK7 expression and poor prognosis. Further, miR-125b inhibited OS cell proliferation and invasion by targeting and downregulating MKK7 in vitro and suppressed tumor formation in vivo. Moreover, using Western blot analysis, we preliminarily proved that the activation (phosphorylation) of STAT3 was regulated by MKK7 at the epigenetic level. MKK7 was overexpressed in OS and associated with poor clinical results. The miR-125b-MAPK-STAT3 axis may be one of the mechanisms of OS oncogenesis and a potential target for the treatment of OS.

Could miRNA Signatures be Useful for Predicting Uterine Sarcoma and Carcinosarcoma Prognosis and Treatment?

Changes in microRNA (miRNA) expression may lead to cancer development and/or contribute to its progression; however, their role in uterine sarcomas is poorly understood. Uterine sarcomas (US) belong to a rare class of heterogeneous tumors, representing about 1% of all gynecologic neoplasms. This study aimed to assess the expression profile of 84 cancer-related miRNAs and to evaluate their correlation with clinical pathological features. Eighty-two formalin-fixed paraffin-embedded (FFPE) samples were selected. In leiomyosarcoma (LMS), there was an association of lower cancer-specific survival (CSS) with the downregulation of miR-125a-5p and miR-10a-5p, and the upregulation of miR-196a-5p and miR-34c-5p. In carcinosarcoma (CS), lower CSS was associated with the upregulation of miR-184, and the downregulation of let-7b-5p and miR-124. In endometrial stromal sarcomas (ESS), the upregulation of miR-373-3p, miR-372-3p, and let-7b-5p, and the down-expression of let-7f-5p, miR-23-3p, and let-7b-5p were associated with lower CSS. Only miR-138-5p upregulation was associated with higher survival rates. miR-335-5p, miR-301a-3p, and miR-210-3p were more highly expressed in patients with tumor metastasis and relapse. miR-138-5p, miR-146b-5p, and miR-218-5p expression were associated with higher disease-free survival (DFS) in treated patients. These miRNAs represent potential prediction markers for prognosis and treatment response in these tumors.

The effects of TRAF6 on proliferation, apoptosis and invasion in osteosarcoma are regulated by miR-124

The present study aimed to verify tumor necrosis factor receptor‑associated factor 6 (TRAF6) as the target gene of microRNA-124 (miR-124). In addition, the expression of miR‑124 was investigated in osteosarcoma tissues and cells, and its effects on the biological characteristics of osteosarcoma cells were determined, in order to provide an experimental and theoretical basis for the application of TRAF6 in the treatment of osteosarcoma. A fluorescence reporter enzyme system was used to verify TRAF6 as a target gene of miR‑124, and western blotting was used to detect the effects of miR‑124 on the protein expression levels of TRAF6 in cells. The expression levels of miR‑124 were detected in osteosarcoma tissues and an osteosarcoma cell line (MG‑63) by quantitative polymerase chain reaction (qPCR). In addition, a total of 48 h post‑transfection of MG‑63 cells with a miR‑124 mimic, qPCR was used to detect the expression levels of miR‑124, and the effects of miR‑124 on the viability of MG‑63 human osteosarcoma cells was determined using the MTT method. The effects of miR‑124 on the cell cycle progression and apoptosis of MG‑63 cells were analyzed by flow cytometry, whereas the effects of miR‑124 on the migration of MG‑63 cells was detected using the Transwell invasion chamber analysis method. A TRAF6 recombinant expression plasmid (pcDNA3.1‑TRAF6) was also constructed, and MG‑63 cells were transfected with the recombinant plasmid and a miR‑124 mimic, in order to further validate the biological role of miR‑124 via the regulation of TRAF6. The results of the present study indicated that, compared with in the normal control group, the expression levels of miR‑124 were significantly increased in MG‑63 cells transfected with a miR‑124 mimic (P<0.01). In addition, the luciferase reporter gene system demonstrated that, compared with in the control group, relative luciferase activity was significantly reduced in the miR‑124 mimic group (P<0.01). The results of MTT analysis indicated that cell viability was also significantly reduced in response to the overexpression of miR‑124 in MG‑63 cells (P<0.01). Flow cytometric analysis demonstrated that the proportion of cells in S phase and G2/M phase was significantly decreased (P<0.01) in cells overexpressing miR‑124, and the number of apoptotic cells was significantly increased (P<0.01). Furthermore, the results of the Transwell invasion assay suggested that the number of invasive cells was significantly decreased following enhanced expression of miR‑124 (P<0.01). In MG‑63 cells overexpressing miR‑124 and TRAF6, the results of MTT, flow cytometric and Transwell assay analyses demonstrated that the overexpression of TRAF6 had the opposite biological effects compared to miR‑124 overexpression. In conclusion, the present study indicated that the expression levels of miR‑124 were downregulated in human osteosarcoma tissues and cells, and that miR‑124 is associated with negative regulation of TRAF6 expression; therefore, the role of TRAF6 in primary osteosarcoma may be regulated by miR‑124. Therapeutic strategies that enhance miR‑124 expression or inhibit TRAF6 expression may be beneficial for the treatment of patients with osteosarcoma.

Anticancer Activity in Honeybee Propolis: Functional Insights to the Role of Caffeic Acid Phenethyl Ester and Its Complex With γ-Cyclodextrin

Besides honey, honeybees make a sticky substance (called propolis/bee glue) by mixing saliva with poplar tree resin and other botanical sources. It is known to be rich in bioactivities of which the anticancer activity is most studied. Caffeic acid phenethyl ester (CAPE) is a key anticancer component in New Zealand propolis. We have earlier investigated the molecular mechanism of anticancer activity in CAPE and reported that it activates DNA damage signaling in cancer cells. CAPE-induced growth arrest of cells was mediated by downregulation of mortalin and activation of p53 tumor suppressor protein. When antitumor and antimetastasis activities of CAPE were examined in vitro and in vivo, we failed to find significant activities, which was contrary to our expectations. On careful examination, it was revealed that CAPE is unstable and rather gets easily degraded into caffeic acid by secreted esterases. Interestingly, when CAPE was complexed with γ-cyclodextrin (γCD) the activities were significantly enhanced. In the present study, we report that the CAPE-γCD complex with higher cytotoxicity to a wide range of cancer cells is stable in acidic milieu and therefore recommended as an anticancer amalgam. We also report a method for preparation of stable and less-pungent powder of propolis that could be conveniently used for health and therapeutic benefits.

Enhancing miR-132 expression by aryl hydrocarbon receptor attenuates tumorigenesis associated with chronic colitis

BACKGROUND

Chronic inflammation in ulcerative colitis (UC) patients is the major risk factor for colitis-associated colon cancer (CAC). Recent evidences have shown that microRNAs (miRNAs) are implicated in CAC pathogenesis. However, the interaction of miRNAs with the transcription factors that alleviate CAC has not been reported.

METHODS

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 3,3'-diindolylmethane (DIM) were used to activate aryl hydrocarbon receptor (Ahr) in azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced CAC in mice. Real-time PCR was used to quantify the mRNAs of miRNA and coding genes while western blot and ELISA were used to quantify protein levels. Silencing miRNA was carried out by means of electroporation and locked nucleic acid (LNA)-miRNA.

RESULTS

Inducing CAC in mice upregulated miR-132 expression in the colon, spleen and lymph nodes at all stages of disease development. Activation of Ahr by TCDD or DIM boosted miR-132 expression and alleviated CAC severity by suppression of macrophage infiltration and pro-inflammatory cytokines. Interestingly, TCDD, but not DIM, augmented a cholinergic anti-inflammation by inducing acetylcholinesterase (AChE)-targeting miR-132. This anti-inflammation was manifested by suppressed production of TNF-α, IL-1β and IL-6. Silencing miR-132 in vivo in TCDD-treated mice abrogated the cholinergic anti-inflammation and exacerbated CAC. In addition, inhibition of miR-132 in vitro in CD4⁺ cells and macrophages mitigated the inhibitory effect of TCDD on AChE catalytic activity.

CONCLUSION

Our findings identify miR-132 as a new molecule implicated in CAC pathogenesis, and reveal that miR-132 mediates the ameliorating effects of TCDD on CAC, suggesting miR-132 as a promising therapeutic candidate to control autoimmune inflammation and tumorigenesis in CAC patients.

MicroRNA-765 Enhances the Anti-Angiogenic Effect of CDDP via APE1 in Osteosarcoma

Human osteosarcoma (HOS) is the most common malignancy in children and adolescents and has a heterogeneous presentation and high mortality. Previous studies have shown that microRNAs contribute to RNA silencing and post-transcriptional regulation of gene expression. Here, we showed that significantly increased expression of miR-765 with or without CDDP (Cisplatin) down-regulates APE1 expression and angiogenesis-related markers (VEGF, FGF2, TGFβ, and CD34). Further investigation showed that miR-765 modulates osteosarcoma cell migration and angiogenesis following treatment with cisplatin in vitro and in vivo. MiR-765 increases the anti-angiogenic effect of CDDP in human osteosarcoma. Elucidation of the mechanism of the miR-765-APE1 axis in tumor progression of HOS will be beneficial in identifying biomarkers and therapeutic target of osteosarcoma.

Overexpression of miR-422a inhibits cell proliferation and invasion, and enhances chemosensitivity in osteosarcoma cells

Osteosarcoma (OS) is an aggressive malignant tumor that is mesenchymal in origin with a very low 5-year survival rate, particularly in the patients with locally advanced or metastatic tumors and recurrent disease. MicroRNAs (miRNAs) play a critical role in essential biological processes as cellular proliferation, differentiation and apoptosis in normal or cancer cells, including OS cells. In the present study, we aimed to investigate the role of miR-422a in OS. We demonstrated that miR-422a expression was significantly downregulated in OS tissues and cell lines compared with the normal controls. In addition, overexpression of miR-422a was able to inhibit cell proliferation and the ability of invasion, and enhance paclitaxel and cisplatin-mediated apoptosis in OS cells. Inversely, downregulation of miR-422a exhibited an opposite role. We further demonstrated that miR-422a directly targeted TGFβ2 and regulated its expression and the activation of downstream molecules, smad2 and smad3 in OS cells. Thus, miR-422a/TGFβ2/smad axis may be a potential target for OS treatment.

MicroRNA-21 Increases Proliferation and Cisplatin Sensitivity of Osteosarcoma-Derived Cells

Osteosarcoma is the most common primary bone tumor and poor prognosis for osteosarcoma patients is mainly due to chemotherapy resistance. MicroRNAs are important to maintain pathophysiological mechanisms of cancer and influence cell sensitivity to chemotherapy. In this study, we tested the functions of microRNA-21 for malignant features as well as for drug resistance of osteosarcoma. We used Northern blot to measure microRNA-21 levels in osteosarcoma-derived cell lines. MicroRNA-21 activity was modulated by either expressing a sponge to decrease its activity in an osteosarcoma-derived cell line expressing high levels of microRNA-21 or by introducing pri-microRNA-21 in a cell line with low endogenous levels. Cell migration was determined in a scratch assay and cell proliferation was measured by performing growth curve analysis. Sensitivity of the cells towards chemotherapeutics was investigated by performing cell viability assays and calculating the IC50 values. While cell migration was unaffected by modulated microRNA-21 levels, microRNA-21 inhibition slowed proliferation and exogenously expressed microRNA-21 promoted this process. Modulated microRNA-21 activity failed to effect sensitivity of osteosarcoma-derived cell lines to doxorubicin or methotrexate. Contrarily, reduction of microRNA-21 activity resulted in enhanced resistance towards cisplatin while ectopic expression of microRNA-21 showed the opposite effect. Increased microRNA-21 levels repressed the expression of Sprouty2 and ectopic expression of Sprouty2 was able to largely rescue the observed effects of microRNA-21 in osteosarcoma. In summary, our data indicate that in osteosarcoma microRNA-21 expression is an important component for regulation of cell proliferation and for determining sensitivity to cisplatin.

Web-based tools for microRNAs involved in human cancer

MicroRNAs (miRNAs/miRs) are a family of small, endogenous and evolutionarily-conserved non-coding RNAs that are involved in the regulation of several cellular and functional processes. miRNAs can act as oncogenes or tumor suppressors in all types of cancer, and could be used as prognostic and diagnostic biomarkers. Databases and computational algorithms are behind the majority of the research performed on miRNAs. These tools assemble and curate the relevant information on miRNAs and present it in a user-friendly manner. The current review presents 14 online databases that address every aspect of miRNA cancer research. Certain databases focus on miRNAs and a particular type of cancer, while others analyze the behavior of miRNAs in different malignancies at the same time. Additional databases allow researchers to search for mutations in miRNAs or their targets, and to review the naming history of a particular miRNA. All these databases are open-access, and are a valuable tool for those researchers working with these molecules, particularly those who lack access to an advanced computational infrastructure.