Overexpression of TRIM44 mediates the NF-κB pathway to promote the progression of ovarian cancer.

BACKGROUND: Ovarian cancer (OC) is the second most commonly seen cancer in the US, and patients with OC are commonly diagnosed in the advanced stage. Research into the molecular mechanisms and potential therapeutic targets of OC is becoming increasingly urgent. In our study, we worked to discover the role of TRIM44 in OC development. OBJECTIVE: This study explored whether the overexpression of TRIM44 mediates the NF-kB pathway to promote the progression of OC. METHODS: A TRIM44 overexpression model was constructed in SKOV3 cells, and the proliferation ability of the cells was detected using the CCK-8 assay. The migration healing ability of cells was detected using cell scratch assay. Cell migration and invasion were detected using Transwell nesting. TUNEL was applied to detect apoptosis, and ELISA and western blot were used to detect the expression of NF-κB signaling pathway proteins. The pathological changes of the tumor tissues were observed using HE staining in a mouse ovarian cancer xenograft model. Immunofluorescence double staining, RT-PCR, and western blot were used to determine the expression of relevant factors in tumour tissues. RESULTS: TRIM44 overexpression promoted the proliferation, migration, and invasion of SKOV3 cells in vitro and inhibited apoptosis while enhancing the growth of tumours in vivo. TRIM44 regulated the NF-κB signaling pathway. CONCLUSIONS: TRIM44 overexpression can regulate the NF-κB signaling pathway to promote the progression of OC, and TRIM44 may be a potential therapeutic target for OC.

TRIM44 Promotes Rabies Virus Replication by Autophagy-Dependent Mechanism.

Tripartite motif (TRIM) proteins are a multifunctional E3 ubiquitin ligase family that participates in various cellular processes. Recent studies have shown that TRIM proteins play important roles in regulating host-virus interactions through specific pathways, but their involvement in response to rabies virus (RABV) infection remains poorly understood. Here, we identified that several TRIM proteins are upregulated in mouse neuroblastoma cells (NA) after infection with the rabies virus using RNA-seq sequencing. Among them, TRIM44 was found to regulate RABV replication. This is supported by the observations that downregulation of TRIM44 inhibits RABV replication, while overexpression of TRIM44 promotes RABV replication. Mechanistically, TRIM44-induced RABV replication is brought about by activating autophagy, as inhibition of autophagy with 3-MA attenuates TRIM44-induced RABV replication. Additionally, we found that inhibition of autophagy with rapamycin reverses the TRIM44-knockdown-induced decrease in LC3B expression and autophagosome formation as well as RABV replication. The results suggest that TRIM44 promotes RABV replication by an autophagy-dependent mechanism. Our work identifies TRIM44 as a key host factor for RABV replication, and targeting TRIM44 expression may represent an effective therapeutic strategy.

TRIM44 aggravates cardiac fibrosis after myocardial infarction via TAK1 stabilization.

Myocardial infarction (MI) is one of the most dangerous cardiovascular events. Cardiac fibrosis is a common pathological feature of remodeling after injury that is related to adverse clinical results with no effective treatment. Previous studies have confirmed that TRIM44, an E3 ligase, can promote the proliferation and migration of various tumor cells. However, the role of TRIM44 in cardiac fibrosis remains unknown. Models of TGF-ß1 stimulation and MI-induced fibrosis were established to investigate the role and potential underlying mechanism of TRIM44 in cardiac fibrosis. The results showed that cardiac fibrosis was significantly inhibited after TRIM44 knockdown in a mouse model of MI, while it was enhanced when TRIM44 was overexpressed. Furthermore, in vitro studies showed that fibrosis markers were significantly reduced in cardiac fibroblasts (CFs) with TRIM44 knockdown, whereas TRIM44 overexpression promoted the expression of fibrosis markers. Mechanistically, TRIM44 maintains TAK1 stability by inhibiting the degradation of k48-linked polyubiquitination-mediated ubiquitination, thereby increasing phosphorylated TAK1 expression in the fibrotic environment and activating MAPKs to promote fibrosis. Pharmacological inhibition of TAK1 phosphorylation reversed the fibrogenic effects of TRIM44 overexpression. Combined, these results suggest that TRIM44 is a potential therapeutic target for cardiac fibrosis.

Silencing LINC00491 inhibits prostate cancer development through the miR-384/TRIM44 axis.

Accumulating evidence has demonstrated the key role of long noncoding (lnc)RNAs in tumorigenesis. Prostate cancer (PCa) is a cancer with high mortality that requires further exploration of the underlying molecular mechanisms. In the present study, we aimed to discover novel potential biomarkers for diagnosing PCa and targeting treatment. Overexpression of the lncRNA, LINC00491, was verified in PCa tumor tissues and cell lines using the real-time polymerase chain reaction. Cell proliferation and invasion were then analyzed via the Cell Counting Kit-8, colony formation, and transwell assays in vitro, and tumor growth in vivo. The interaction of miR-384 with LINC00491, as well as TRIM44, was investigated via bioinformatics analyses, subcellular fractionation, luciferase reporter gene assays, radioimmunoprecipitation, pull-down, and western blot analyses. LINC00491 was overexpressed in PCa tissues and cell lines. LINC00491 knockdown resulted in impaired cell proliferation and invasion in vitro and decreased tumor growth in vivo. Moreover, LINC00491 acted as a sponge for miR-384 and its downstream target, TRIM44. Additionally, miR-384 expression was downregulated in PCa tissues and cell lines, and its expression was negatively correlated with LINC00491. A miR-384 inhibitor restored the inhibitory effects of LINC00491 silencing on PCa cell proliferation and invasion. LINC00491 is a tumor promoter in PCa via enhancing TRIM44 expression by sponging miR-384 to facilitate the development of PCa. LINC00491 plays a significant role in PCa and could serve as both a biomarker for early diagnosis and a novel treatment target.

TRIM-containing 44 aggravates cardiac hypertrophy via TLR4/NOX4-induced ferroptosis.

TRIM-containing 44 (TRIM44) is a promoter of multiple cancers. However, its role in cardiac hypertrophy has not been elucidated. This study explored the role of TRIM44 on pressure overload-induced cardiac hypertrophy in mice. Mice were subjected to aortic banding to establish an adverse cardiac hypertrophy model, followed by the administration of AAV9-TRIM44 or AAV9shTRIM44 to overexpress or knock down TRIM44. Echocardiography was used to assess cardiac function. H9c2 cells were cultured and transfected with either Ad-TRIM44 or TRIM44 siRNA to overexpress or silence TRIM44. Cells were also stimulated with angiotensin II to establish a cardiomyocyte hypertrophy model. Results indicated that TRIM44 was downregulated in mice hearts and cardiomyocytes that were treated with aortic banding or angiotensin II. TRIM44 overexpression in mice hearts aggravated cardiac hypertrophy and fibrosis, as well as inhibited cardiac function post-aortic banding. Moreover, mice with TRIM44 overexpression displayed increased ferroptosis post-aortic banding. Mice with TRIM44 knockdown revealed ameliorated cardiac hypertrophy, ferroptosis, and fibrosis, as well as improved cardiac function post-aortic banding. In H9c2 cells transfected with Ad-TRIM44, angiotensin II-induced ferroptosis was enhanced, while cells with silenced TRIM44 reported reduced ferroptosis post-angiotensin II administration. Furthermore, TRIM44 interacted with TLR4, which increased the expression of NOX4 and subsequently augmented ferroptosis-associated protein levels. By using TLR4 knockout mice, the inhibitory role of TRIM44 was reduced post-aortic banding. Taken together, TRIM44 aggravated pressure overload-induced cardiac hypertrophy via increased TLR4/NOX4-associated ferroptosis. KEY MESSAGES: TRIM44 could aggregate pressure overload-induced cardiac hypertrophy via increasing TLR4-NOX4 associated ferroptosis. Target TRIM44 may become a new therapeutic method for preventing or treating pressure overload-induced cardiac hypertrophy.

TRIM44 regulates tumor immunity in gastric cancer through LOXL2-dependent extracellular matrix remodeling.

PURPOSE: Gastric cancer is a gastrointestinal malignancy with high mortality and poor prognosis, and the molecular mechanism of gastric tumorigenesis remains unclear. TRIM44 has been reported to be involved in tumor development. However, the role of TRIM44 in tumor immunity is largely unknown. METHODS: We analyzed TRIM44 expression in clinical gastric cancer tissues and normal tissues by using western blot, quantitative real-time PCR and bioinformatics analyses. We further investigated the involvement of TRIM44 in tumor immunity in vivo and found that it was dependent on extracellular matrix remodeling. We detected the interaction between TRIM44 and LOXL2 by using immunofluorescence staining and coimmunoprecipitation assays. We observed that TRIM44 mediates the stability of LOXL2 by ubiquitination assays. RESULTS: TRIM44 expression is high and is correlated with T-cell infiltration in gastric cancer. TRIM44 inhibits gastric tumorigenicity by regulating T-cell-mediated antitumor immunity and modulating the protein level of LOXL2. Mechanistically, TRIM44 directly binds to LOXL2 and affects the stability of LOXL2 to change extracellular matrix remodeling and influence tumor immunity. CONCLUSION: These findings demonstrate that TRIM44 regulates the stability of LOXL2 to remodel the tumor extracellular matrix to modulate tumor immunity in gastric cancer and that the TRIM44/LOXL2 complex is a promising biomarker for gastric cancer prognosis and might be a novel immunotherapy target.

Cardiac-specific Trim44 knockout in rat attenuates isoproterenol-induced cardiac remodeling via inhibition of AKT/mTOR pathway.

When pathological hypertrophy progresses to heart failure (HF), the prognosis is often very poor. Therefore, it is crucial to find new and effective intervention targets. Here, myocardium-specific Trim44 knockout rats were generated using CRISPR-Cas9 technology. Cardiac phenotypic observations revealed that Trim44 knockout affected cardiac morphology at baseline. Rats with Trim44 deficiency exhibited resistance to cardiac pathological changes in response to stimulation via isoproterenol (ISO) treatment, including improvement of cardiac remodeling and dysfunction by morphological and functional observations, reduced myocardial fibrosis and reduced expression of molecular markers of cardiac stress. Furthermore, signal transduction validation associated with growth and hypertrophy development in vivo and in vitro demonstrated that Trim44 deficiency inhibited the activation of signaling pathways involved in myocardial hypertrophy, especially response to pathological stress. In conclusion, the present study indicates that Trim44 knockout attenuates ISO-induced pathological cardiac remodeling through blocking the AKT/mTOR/GSK3ß/P70S6K signaling pathway. This is the first study to demonstrate the function and importance of Trim44 in the heart at baseline and under pathological stress. Trim44 could be a novel therapeutic target for prevention of cardiac hypertrophy and HF.

Silencing of TRIM44 Inhibits Inflammation and Alleviates Traumatic Brain Injury in Rats by Downregulating TLR4-NF-κB Signaling.

BACKGROUND: Neuroinflammation subsequent to traumatic brain injury (TBI) is important for the recovery of patients and is associated with neurodegenerative changes post-TBI. The tripartite motif containing 44 (TRIM44) protein is an E3 ligase involved in the regulation of immune function with no previously known link to TBI. This study explores the connection between TRIM44 and TBI. METHODS: After induction of TBI in rats by control cortex injury, TRIM44 expressions were determined with quantitative real-time reverse transcription polymerase chain reaction and Western blot, and Toll-like receptor 4 (TLR4)-NF-κB signaling was examined by the expression of TLR4, p65 phosphorylation, and the specific NF-κB transcription activity. The effects of TRIM44 knockdown on inflammation, neurological function, and TLR4-NF-κB signaling in TBI rats were revealed by the detection of proinflammatory cytokines and TLR4-NF-κB signaling molecules, modified neurological severity score, brain water content, and Evans blue permeability. RESULTS: We found that TRIM44 expression was significantly increased following TBI induction along with TLR4-NF-κB activation. Silencing of TRIM44 suppressed proinflammatory cytokine production, improved neurological outcomes, alleviated brain edema, and inhibited TLR4-NF-κB signaling in TBI rats. CONCLUSION: Our findings suggest that suppressing TRIM44 or modulation of relevant pathways may be a therapeutic strategy for TBI.

TRIM44 promotes BRCA1 functions in HR repair to induce Cisplatin Chemoresistance in Lung Adenocarcinoma by Deubiquitinating FLNA.

Tripartite motif-containing 44 (TRIM44) has recently been implicated in various pathological processes in numerous cancers, including lung adenocarcinoma (LUAD); however, its functional roles in chemoresistance are poorly understood. Herein, TRIM44 knockdown sensitized LUAD cells to cisplatin and enhanced cisplatin-induced apoptosis. Microarray analysis indicated that the "Role of BRCA1 in DNA damage" and the BRCA1 gene expression were positively regulated by TRIM44, which was further verified by immunofluorescence, qRT-PCR, and Western blotting. BRCA1 depletion effectively abolished TRIM44-modulated cisplatin resistance and regulation of homologous recombination (HR) repair. Interestingly, TRIM44 interacted with FLNA, an upstream regulator of BRCA1 as specified by STRING V 11.5, and facilitated its stability and deubiquitination. FLNA was also found to be required for the functions of TRIM44 in drug resistance. Using animal models, overexpression of TRIM44 was shown to confer resistance to cisplatin in a BRCA1- and FLNA-dependent manner. TRIM44 expression levels in tissues from cisplatin-resistant LUAD patients were significantly higher than those in tissues from cisplatin-sensitive LUAD patients. Collectively, our study results demonstrate that the TRIM44/FLNA/BRCA1 axis is involved in cisplatin chemoresistance, providing potential therapeutic targets for LUAD patients with cisplatin resistance.

Clinical Significance of TRIM44 Expression in Patients with Gastric Cancer.

BACKGROUND: Despite the tremendous efforts in finding a valuable markers for risk stratifying gastric cancer (GC) patients; still, management of this cancer faces multiple obstacles. Given this, we designed a study to explore the possible relationship between the tripartite motif-containing 44 (TRIM44) gene expression, and the outcome of the GC patients. METHODS: The real-time quantitative PCR method was used to evaluate the mRNA expression level of TRIM44, and ß-catenin in fresh primary tumor and adjacent normal tissues collected from 40 GC patients. The Pearson's correlation test, Kaplan-Meier method, and Cox proportional-hazards regression were performed to examine the association of TRIM44 expression with some clinicopathological data and the patients' overall survival (OS). RESULTS: The expression level of both TRIM44 and ß-catenin was remarkably higher in GC tissues than in normal tissues (Fold change=1.71, p=0.004). In subgroup analysis based on the TRIM44 expression, pateints with high TRIM44 expression level exhibited poorer overall survival (HR = 1.46, 95% CI: 1.07-1.98, p=0.016). More strikingly, a positive correlation was also found between the expression of TRIM44 and ß-catenin in GC, indicating that TRIM44 might exert its oncogenic activities probably through the ß-catenin axis. CONCLUSION: This study highlighted the potent value of TRIM44 as an independent prognostic factor in gastric cancer and shed light on the probable interplay between this tripartite motif-containing protein and ß-catenin. However, further investigations, especially with a larger sample size, are required to study the effect of TRIM44 in GC more precisely.

Knockdown of TRIM44 inhibits the progression of ovarian cancer and is related to the FOXM1-EZH2 signaling pathway.

Background: Tripartite motif-containing protein 44 (TRIM44) was recently identified as a novel oncogene that is overexpressed in several types of human cancers. However, the biological functions of TRIM44 in epithelial ovarian cancer (EOC) remain unclear. Here, we aimed to investigate the role of TRIM44 in EOC and its clinical implications. Methods: TRIM44 was knocked down using shRNA transfection. In vitro proliferation, invasion, migration and apoptosis of ovarian cancer (OC) cells were detected by CCK8, colony formation assay, Transwell inserts and flow cytometry analysis. The growth ability of xenograft tumors was examined in vivo in a nude mouse metastatic tumor model. Finally, we performed gene chip analysis and ingenuity pathway analysis (IPA) to analyze the potential gene network. Results: High expression of TRIM44 was observed in EOC tissues. Knockdown of TRIM44 expression substantially suppressed the proliferation, migration, invasion and colony-forming ability of EOC cells in vitro and attenuated tumor growth in vivo. Mechanistic studies revealed that silencing TRIM44 dramatically downregulated the expression of FOXM1, EZH2, CCNE2, CCND3 and BIRC5 in EOC cells, at least in part through inactivation of the FOXM1-EZH2 signaling pathway. Conclusions: Collectively, these data suggest that downregulation of TRIM44 inhibits the progression of EOC through suppression of the FOXM1-EZH2 signaling pathway. These results provide novel insight into the role of TRIM44 in tumorigenesis and suggest that it could be a potential therapeutic target for ovarian carcinoma.

CircFBXW8 Acts an Oncogenic Role in the Malignant Progression of Non-small Cell Lung Carcinoma by miR-370-3p-Dependent Regulation of TRIM44.

Non-small cell lung carcinoma (NSCLC) is an aggressive malignant tumor. Growing evidences have revealed that circular RNA (circRNA) is involved in NSCLC progression. This study aims to investigate the role of circular RNA F-box and WD repeat domain containing 8 (circFBXW8) in NSCLC progression and the underlying mechanism. The expression of circFBXW8, microRNA-370-3p (miR-370-3p) and tripartite motif containing 44 (TRIM44) mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Protein expression was detected by western blot analysis or immunohistochemistry assay. Additionally, cell viability, colony-forming ability, proliferation and apoptosis were investigated by 3-(4,5-Dimethylthazol-2-yl)-2,5-diphenyltetrazolium bromide, cell colony formation, 5-Ethynyl-29-deoxyuridine and flow cytometry analysis assays, respectively. Cell migratory and invasive abilities were examined by wound-healing and transwell assays. The regulatory relationship between miR-370-3p and circFBXW8 or TRIM44 was identified by dual-luciferase reporter and RNA pull-down assays. Furthermore, xenograft experiment was employed to explain the effect of circFBXW8 silencing on tumor formation. CircFBXW8 and TRIM44 expression were upregulated, while miR-370-3p was downregulated in NSCLC tissues, cells and the exosomes from NSCLC cells compared with respective controls. CircFBXW8 depletion repressed NSCLC cell proliferation, migration and invasion, but promoted cell apoptosis. CircFBXW8 acted as a sponge of miR-370-3p and regulated NSCLC cell malignancy by binding to miR-370-3p. Additionally, miR-370-3p repressed NSCLC cell processes by regulating TRIM44. CircFBXW8 knockdown inhibited tumor formation in vivo. Further, circFBXW8 secretion was mediated by exosomes. CircFBXW8 modulated NSCLC progression by increasing TRIM44 expression through sponging miR-370-3p, which provided a new direction for studying the therapy of NSCLC.

Sesamin exerts anti-tumor activity in esophageal squamous cell carcinoma via inhibition of TRIM44 and NF-κB signaling.

Tripartite motif-containing 44 (TRIM44) is known to play an oncogenic role in multiple human cancers, including esophageal cancer. Sesamin possesses potent anti-inflammatory and anti-cancer properties for various cancers. This study is designed to unravel the biological functions of sesamin and TRIM44 in esophageal cancer. TRIM44 expression in esophageal squamous cell cancer (ESCC) cell lines and tissues was determined by RT-qPCR assay and Western blot. The effects of sesamin and TRIM44 on ESCC cell growth in vivo and in vitro were assessed by the mouse model and CCK-8 assay, respectively. We found that TRIM44 was significantly upregulated in ESCC cell lines and tissues when compared to their counterparts. Sesamin treatment or depletion of TRIM44 markedly reduced ESCC cell proliferation. The nuclear factor kappa B (NF-κB) and toll-like receptor 4 (TLR4) signaling pathway may be involved in sesamin-mediated TRIM44 suppression. Finally, we showed that oral administration of sesamin dramatically inhibited tumor growth or ESCC in nude mice. Our results suggest that sesamin exerts anti-tumor activity in ESCC via inhibition of NF-κB signaling pathway, demonstrating its potential for the treatment of esophageal cancer.

Knockdown of circRAD23B Exerts Antitumor Response in Colorectal Cancer via the Regulation of miR-1205/TRIM44 axis.

BACKGROUND: Colorectal cancer (CRC) is a common cancer with high metastatic property. Circular RNAs (circRNAs) have important involvement in cancer processes. This study focused on the regulation of circRNA RAD23 homologue B (circRAD23B) in CRC. METHODS: The levels of circRAD23B, microRNA-1205 (miR-1205), and tripartite motif-44 (TRIM44) were examined by quantitative real-time polymerase chain reaction (qRT-PCR). Functional analyses were performed by Cell Counting Kit-8 (CCK-8) for cell proliferation, flow cytometry for cell cycle or cell apoptosis, and transwell assay for cell migration and invasion. Western blot was administrated for protein detection. The interaction of targets was analyzed by dual-luciferase reporter and RNA pull-down assays. The in vivo experiment was conducted via xenograft tumor in mice. RESULTS: We identified that circRAD23B was overexpressed in CRC tissues and cells. CRC cell proliferation, cell cycle progression, and cell metastasis were inhibited, while apoptosis was promoted by downregulating circRAD23B. Target analysis indicated that circRAD23B-targeted miR-1205 and TRIM44 were downstream genes of miR-1205. Moreover, the antitumor response of circRAD23B downregulation and miR-1205 overexpression was, respectively, achieved by increasing miR-1205 and decreasing TRIM44. CircRAD23B could regulate TRIM44 level by sponging miR-1205. In vivo, circRAD23B knockdown also reduced CRC tumorigenesis via the miR-1205/TRIM44 axis. CONCLUSION: These results suggested that the inhibition of circRAD23B retarded the progression of CRC via acting on the miR-1205/TRIM44 axis. CircRAD23B might be a novel target in CRC treatment.

TRIM44 links the UPS to SQSTM1/p62-dependent aggrephagy and removing misfolded proteins.

Until recently, the ubiquitin-proteasome system (UPS) and macroautophagy/autophagy were considered to be two independent systems that target proteins for degradation by proteasomes or via lysosomes, respectively. Here, we report that TRIM44 (tripartite motif containing 44) is a novel link that connects the UPS system with the autophagy degradation pathway. Suppressing the UPS degradation pathway leads to TRIM44 upregulation, which further promotes aggregated protein clearance through the binding of K48 ubiquitin chains on proteins. TRIM44 expression activates autophagy via promoting SQSTM1/p62 oligomerization, which rapidly increases the rate of aggregate protein removal. Overall, our data reveal that TRIM44 is a newly identified link between the UPS system and the autophagy pathway. Delineating the cross-talk between these two degradation pathways may reveal new mechanisms of targeting aggregate-prone diseases, such as cancer and neurodegenerative disease.Abbreviations: 3-MA: 3-methyladenine; ACTB: actin beta; ATG5: autophagy related 5; BB: B-box domain; BECN1: beclin1; BM: bone marrow; CC: coiled-coil domain; CFTR: cystic fibrosis transmembrane conductance regulator; CON: control; CQ: chloroquine; DOX: doxycycline; DSP: dithiobis(succinimidly propionate); ER: endoplasmic reticulum; FI: fluorescence intensity; FL: full length; HIF1A/HIF-1#x3B1;: hypoxia inducible factor 1 subunit alpha; HSC: hematopoietic stem cells; HTT: huntingtin; KD: knockdown; KD-CON: knockdown construct control; MM: multiple myeloma; MTOR: mechanistic target of rapamycin kinase; NP-40: nonidet P-40; NFE2L2/NRF2: nuclear factor, erythroid 2 like 2; OE: overexpression; OE-CON: overexpression construct control; PARP: poly (ADP-ribose) polymerase; SDS: sodium dodecyl sulfate; SQSTM1/p62: sequestosome 1; Tet-on: tetracycline; TRIM44: tripartite motif containing 44; UPS: ubiquitin-proteasome system; ZF: zinc-finger.

YTHDF1 promotes the proliferation, migration, and invasion of prostate cancer cells by regulating TRIM44.

BACKGROUND: Prostate cancer (PCa) is one of the most common malignancies in men. YTHDF1 may play an important role in promoting PCa progression, but there is no reports to date on YTHDF1 function in PCa. OBJECTIVE: This study explored whether YTHDF1 could regulate TRIM44 in PCa cells. METHODS: By querying the TCGA database, we evaluated YTHDF1 expression in PCa, the OS and DFS of YTHDF1, and the correlation between YTHDF1 and TRIM44 in PCa. We constructed vectors to interfere with YTHDF1 expression and overexpress TRIM44 to examine the role of YTHDF1 and TRIM44 in PCa cells. Differentially expressed mRNAs were identified by mRNA sequencing. The levels of YTHDF1, TRIM44, LGR4, SGTA, DDX20, and FZD8 were measured by qRT-PCR and WB was used to determine YTHDF1 and TRIM44 expression. A CCK-8 assay was used to assess cell proliferation. A Transwell chamber assay was used measure cell migration and invasion ability. RESULTS: YTHDF1 was highly expressed in both Pca tissues and cells. PCa patient prognosis with high YTHDF1 expression was relatively poor. Cell function experiments showed that inhibiting YTHDF1 expression decreased cell proliferation, migration, and invasion. RNA sequencing analysis revealed that YTHDF1 may promote PCa cell proliferation, migration, and invasion by modulating TRIM44 expression. Cell function experiments further verified that YTHDF1 promoted PCa cell proliferation, migration, and invasion by regulating TRIM44. CONCLUSIONS: YTHDF1 enhances PCa cell proliferation, migration, and invasion by regulating TRIM44.

circ_0030018 promotes glioma proliferation and metastasis.

BACKGROUND: Circular RNA (circRNA) plays an essential role in tumor progression, including glioma. circ_0030018 is a newly discovered circRNA that is highly expressed in glioma. However, its role and mechanism in glioma need to be further elucidated. METHODS: The expression of circ_0030018, microRNA (miR)-194-5p, and tripartite motif containing 44 (TRIM44) was examined using quantitative real-time PCR. Cell proliferation, migration, invasion, and apoptosis were determined using MTT assay, colony formation assay, transwell assay, and flow cytometry. Moreover, dual-luciferase reporter assay and RNA pull-down assay were used to verify the interactions among circ_0030018, miR-194-5p, and TRIM44. The protein expression of TRIM44 was assessed by western blot analysis. Animal experiments were conducted to explore the role of circ_0030018 in glioma tumor growth in vivo. RESULTS: circ_0030018 was overexpressed in glioma tissues and cells, and its silencing could inhibit glioma cell proliferation, migration, invasion, and accelerate apoptosis. miR-194-5p could be sponged by circ_0030018, and its overexpression could hinder the progression of glioma cells. Further experiments revealed that miR-194-5p inhibitor reversed the negative regulation of circ_0030018 knockdown on glioma cell progression. In addition, TRIM44 was a target of miR-194-5p, and its downregulation could repress glioma cell progression. Overexpressed TRIM44 reversed the inhibition effect of miR-194-5p on glioma cell progression. Animal experiments suggested that circ_0030018 knockdown could reduce glioma tumor growth through regulating miR-194-5p and TRIM44. CONCLUSION: Our 8data showed that circ_0030018 enhanced glioma progression by sponging miR-194-5p to regulate TRIM44, indicating that circ_0030018 might be a potential treatment target for glioma.

Circular RNA circWDR27 Promotes Papillary Thyroid Cancer Progression by Regulating miR-215-5p/TRIM44 Axis.

PURPOSE: This study was to explore the biological roles and underlying mechanism of circRNA WD repeat domain 27 (circWDR27). METHODS: The expression of circWDR27, microRNA-215-5p (miR-215-5p) and tripartite motif containing 44 (TRIM44) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays were employed to detect cell proliferation. Flow cytometry was used to determine cell apoptosis and cell cycle distribution. Cell migration and invasion abilities were examined by wound healing and transwell assays. The protein levels of matrix metalloproteinase 2 (MMP2), MMP9 and TRIM44 were analyzed by Western blot assay. The relationship between miR-215-5p and circWDR27 or TRIM44 was predicted by bioinformatics tools and confirmed using dual-luciferase reporter assay. Mouse xenograft model was established to examine the role of circWDR27 in vivo. RESULTS: CircWDR27 and TRIM44 were highly expressed while miR-215-5p was lowly expressed in PTC tissues and cells. Knockdown of circWDR27 suppressed cell proliferation and metastasis and induced cell cycle arrest and apoptosis in PTC cells. Moreover, miR-215-5p was a direct target of circWDR27, and its inhibition reversed the suppressive effect of circWDR27 knockdown on PTC cell progression. In addition, miR-215-5p directly targeted TRIM44, and miR-215-5p exerted its anti-cancer role in PTC cells by targeting TRIM44. Furthermore, circWDR27 positively regulated TRIM44 expression by sponging miR-215-5p. Importantly, knockdown of circWDR27 suppressed tumor growth in vivo by upregulating miR-215-5p and downregulating TRIM44. CONCLUSION: CircWDR27 accelerates PTC progression via regulating miR-215-5p/TRIM44 axis, providing a potential therapeutic target for PTC.

Circ_0056285 Regulates Proliferation, Apoptosis and Glycolysis of Osteosarcoma Cells via miR-1244/TRIM44 Axis.

BACKGROUND: Osteosarcoma (OS) is a common malignant bone cancer that occurs in adolescents and children. Circular RNAs (circRNAs) are important regulators of tumorigenesis and development. This study aimed to explore the role and molecular basis of circ_0056285 in OS. METHODS: The levels of circ_0056285, miR-1244 and tripartite motif containing 44 (TRIM44) were determined by quantitative real-time polymerase chain reaction or Western blot assay. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) assay and colony formation assay. Cell apoptosis was assessed by flow cytometry and caspase 3and caspase 9 activity assay kits. Glucose uptake, lactate product and ATP level were examined using commercial kits. Hexokinase II (HK2) and lactate dehydrogenase A (LDHA) levels were measured by Western blot assay. The interaction among circ_0056285, miR-1244 and TRIM44 was confirmed by dual-luciferase reporter assay, RNA immunoprecipitation assay or RNA pull-down assay. Xenograft experiment was conducted to explore tumor growth in vivo. Exosomes were identified by transmission electron microscope (TEM), nanoparticle tracking analysis (NTA) and Western blot. The diagnostic value of exosomal circ_0056285 was evaluated by receiver operating characteristic (ROC) curve. RESULTS: Circ_0056285 and TRIM44 were up-regulated, and miR-1244 was down-regulated in OS tissues and cells. Circ_0056285 silencing inhibited proliferation and glycolysis and promoted apoptosis in OS cells. Also, circ_0056285 knockdown hindered proliferation and accelerated apoptosis in OS cells by regulating miR-1244/TRIM44 axis. Circ_0056285 depletion impeded tumor growth in vivo. Furthermore, ROC curve showed that circ_0056285 might be a diagnostic biomarker in OS. CONCLUSION: Circ_0056285 facilitated OS progression by sponging miR-1244 and increasing TRIM44 expression, providing a promising therapeutic target for OS.

Circular RNA circ_0020123 Promotes Non-Small Cell Lung Cancer Progression Through miR-384/TRIM44 Axis.

BACKGROUND: It was reported that circular RNAs (circRNAs) and microRNAs (miRNAs) were related to non-small cell lung cancer (NSCLC) development. However, the detailed mechanisms of circ_0020123 and miR-384 in NSCLC are elusive. METHODS: QRT-PCR and Western blot assay were performed to detect the transcription and protein levels of genes, respectively. Then, the functional experiments, including MTT assay, flow cytometry, and transwell assay, were employed. Besides, the interaction between miR-384 and circ_0020123 or tripartite motif­containing protein 44 (TRIM44) was predicted by starbase or targetscan, and then verified by the dual-luciferase reporter, RNA pull-down assays and RNA immunoprecipitation assay (RIP). Mouse xenograft assay was performed to evaluate the effect of circ_0020123 on tumor growth in vivo. RESULTS: Levels of circ_0020123 and TRIM44 were enhanced, and the miR-384 level was attenuated in NSCLC tissues and cells. Circ_0020123 depletion attenuated the abilities of NSCLC cell viability, migration, invasion, and epithelial-mesenchymal transition (EMT), and induced apoptosis. Besides, circ_0020123 interacted with miR-384, and miR-384 targeted TRIM44. Circ_0020123 regulated cell progression by regulating miR-384 and subsequently mediated TRIM44 expression. Besides, circ_0020123 depletion repressed tumor growth in vivo. CONCLUSION: We demonstrated that circ_0020123 knockdown suppressed NSCLC cell progression by regulating the miR-384/TRIM44 axis, providing the theoretical basis for the therapy of NSCLC.