TRIM31 is downregulated in non-small cell lung cancer and serves as a potential tumor suppressor

An investigation of the molecular characterization of the tripartite motif (TRIM) family and primary validation of TRIM31 in gastric cancer

Most TRIM family members characterized by the E3-ubiquitin ligases, participate in ubiquitination and tumorigenesis. While there is a dearth of a comprehensive investigation for the entire family in gastric cancer (GC). By combining the TCGA and GEO databases, common TRIM family members (TRIMs) were obtained to investigate gene expression, gene mutations, and clinical prognosis. On the basis of TRIMs, a consensus clustering analysis was conducted, and a risk assessment system and prognostic model were developed. Particularly, TRIM31 with clinical prognostic and diagnostic value was chosen for single-gene bioinformatics analysis, in vitro experimental validation, and immunohistochemical analysis of clinical tissue microarrays. The combined dataset consisted of 66 TRIMs, of which 52 were differentially expressed and 43 were differentially prognostic. Significant survival differences existed between the gene clusters obtained by consensus clustering analysis. Using 4 differentially expressed genes identified by multivariate Cox regression and LASSO regression, a risk scoring system was developed. Higher risk scores were associated with a poorer prognosis, suppressive immune cell infiltration, and drug resistance. Transcriptomic data and clinical sample tissue microarrays confirmed that TRIM31 was highly expressed in GC and associated with a poor prognosis. Pathway enrichment analysis, cell migration and colony formation assay, EdU assay, reactive oxygen species (ROS) assay, and mitochondrial membrane potential assay revealed that TRIM31 may be implicated in cell cycle regulation and oxidative stress-related pathways, contribute to gastric carcinogenesis. This study investigated the whole functional and expression profile and a risk score system based on the TRIM family in GC. Further investigation centered around TRIM31 offers insight into the underlying mechanisms of action exhibited by other members of its family in the context of GC.

E3 ubiquitin ligase TRIM31: A potential therapeutic target

Ubiquitination is a key mechanism for post-translational protein modification, affecting protein localization, metabolism, degradation and various cellular physiological processes. Dysregulation of ubiquitination is associated with the pathogenesis of various diseases, such as tumors and cardiovascular diseases, making it a primary area of interest in biochemical research and drug development endeavors. E3 ubiquitin ligases play a pivotal role in modulating the ubiquitination of substrate proteins through their unique recognition functions. TRIM31, a member of the TRIM family of E3 ubiquitin ligases, is aberrantly expressed in different pathophysiological conditions. The biological function of TRIM31 is associated with the occurrence and development of diverse diseases. TRIM31 has been demonstrated to inhibit inflammation by promoting ubiquitin-proteasome-mediated degradation of the sensing protein NLRP3 in the inflammasome. TRIM31 mediates ubiquitination of MAVS, inducing the formation of prion-like aggregates, and triggering innate antiviral immune responses. TRIM31 is also implicated in tumor pathophysiology through its ability to promote ubiquitination of the tumor suppressor protein p53. These findings indicate that TRIM31 is a potential therapeutic target, and subsequent in-depth research of TRIM31 is anticipated to provide information on its clinical application in therapy.

A genome-wide association study of contralateral breast cancer in the Women's Environmental Cancer and Radiation Epidemiology Study

BACKGROUND

Contralateral breast cancer (CBC) is the most common second primary cancer diagnosed in breast cancer survivors, yet the understanding of the genetic susceptibility of CBC, particularly with respect to common variants, remains incomplete. This study aimed to investigate the genetic basis of CBC to better understand this malignancy.

FINDINGS

We performed a genome-wide association analysis in the Women's Environmental Cancer and Radiation Epidemiology (WECARE) Study of women with first breast cancer diagnosed at age < 55 years including 1161 with CBC who served as cases and 1668 with unilateral breast cancer (UBC) who served as controls. We observed two loci (rs59657211, 9q32, SLC31A2/FAM225A and rs3815096, 6p22.1, TRIM31) with suggestive genome-wide significant associations (P < 1 × 10-6). We also found an increased risk of CBC associated with a breast cancer-specific polygenic risk score (PRS) comprised of 239 known breast cancer susceptibility single nucleotide polymorphisms (SNPs) (rate ratio per 1-SD change: 1.25; 95% confidence interval 1.14-1.36, P < 0.0001). The protective effect of chemotherapy on CBC risk was statistically significant only among patients with an elevated PRS (Pheterogeneity = 0.04). The AUC that included the PRS and known breast cancer risk factors was significantly elevated.

CONCLUSIONS

The present GWAS identified two previously unreported loci with suggestive genome-wide significance. We also confirm that an elevated risk of CBC is associated with a comprehensive breast cancer susceptibility PRS that is independent of known breast cancer risk factors. These findings advance our understanding of genetic risk factors involved in CBC etiology.

Intricate confrontation: Research progress and application potential of TRIM family proteins in tumor immune escape

BACKGROUND

Tripartite motif (TRIM) family proteins have more than 80 members and are widely found in various eukaryotic cells. Most TRIM family proteins participate in the ubiquitin-proteasome degradation system as E3-ubiquitin ligases; therefore, they play pivotal regulatory roles in the occurrence and development of tumors, including tumor immune escape. Due to the diversity of functional domains of TRIM family proteins, they can extensively participate in multiple signaling pathways of tumor immune escape through different substrates. In current research and clinical contexts, immune escape has become an urgent problem. The extensive participation of TRIM family proteins in curing tumors or preventing postoperative recurrence and metastasis makes them promising targets.

AIM OF REVIEW

The aim of the review is to make up for the gap in the current research on TRIM family proteins and tumor immune escape and propose future development directions according to the current progress and problems.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This up-to-date review summarizes the characteristics and biological functions of TRIM family proteins, discusses the mechanisms of TRIM family proteins involved in tumor immune escape, and highlights the specific mechanism from the level of structure-function-molecule-pathway-phenotype, including mechanisms at the level of protein domains and functions, at the level of molecules and signaling pathways, and at the level of cells and microenvironments. We also discuss the application potential of TRIM family proteins in tumor immunotherapy, such as possible treatment strategies for combination targeting TRIM family protein drugs and checkpoint inhibitors for improving cancer treatment.

Tripartite motif 31 drives gastric cancer cell proliferation and invasion through activating the Wnt/β-catenin pathway by regulating Axin1 protein stability

Mounting evidence has proposed the importance of the Wnt/β-catenin pathway and tripartite motif 31 (TRIM31) in certain malignancies. Our research aimed to clarify the correlation between aberrant TRIM31 expression and the Wnt/β-catenin pathway during gastric cancer (GC) oncogenesis and development. TRIM31 was drastically elevated in GC tissues and was closely associated with aggressive clinical outcomes and poor prognosis. Moreover, TRIM31 downregulation attenuated GC cell proliferation and invasion in vitro. Mechanistically, TRIM31 could bind and ubiquitinate Axin1 protein, thereby facilitating the activation of the Wnt/β-catenin pathway. Additionally, Axin1 knockdown partially abrogated the inhibitory effects on the proliferative, invasive and migratory abilities of GC cells induced by TRIM31 silencing. Furthermore, TRIM31 was negatively correlated with Axin1 protein expression in GC tissues. In summary, we revealed a new TRIM31-Axin1-Wnt/β-catenin axis that contributed greatly to the progression of GC, and targeting this regulatory axis may represent an effective treatment for GC patients.

TRIM31: A molecule with a dual role in cancer

Tripartite motif (TRIM) 31 is a new member of the TRIM family and functions as an E3 ubiquitin ligase. Abnormal TRIM31 expression leads to a variety of pathological conditions, such as cancer, innate immunity diseases, sepsis-induced myocardial dysfunction, cerebral ischemic injury, nonalcoholic fatty liver disease and hypertensive nephropathy. In this review, we comprehensively overview the structure, expression and regulation of TRIM31 in cancer. Moreover, we discuss the dual role of TRIM31 in human cancer, and this dual role may be linked to its involvement in the selective regulation of several pivotal cellular signaling pathways: the p53 tumor suppressor, mTORC1, PI3K-AKT, NF-κB and Wnt/β-catenin pathways. In addition, we also discuss the emerging role of TRIM31 in innate immunity, autophagy and its growing sphere of influence across multiple human pathologies. Finally, a better understanding of the dual role of TRIM31 in cancer may provide new therapeutic strategies aimed at inhibiting the cancer-promoting effects of TRIM31 without affecting its tumor suppressor effects.

CircNFIX knockdown inhibited AML tumorigenicity by the miR-876-3p/TRIM31 axis

BACKGROUND

Acute myeloid leukemia (AML) is one of the most common malignant myeloid diseases in adults with a dismal prognosis. We aimed to explore the effects of circNFIX on the proliferation and apoptosis of AML cells.

METHODS

The expressions of circNFIX, miR-876-3p and tripartite motif (TRIM) 31 in the bone marrow specimens of AML patients and AML cell lines were detected by qRT-PCR or western blot. Cell proliferation was evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and 5-ethynyl-29-deoxyuridine (EdU) assays. Cell cycle and apoptosis were analyzed by flow cytometry. Western blot was used to detect protein expression. The relationship between miR-876-3p and circNFIX or TRIM31 was identified by dual-luciferase reporter assay or RNA pull-down assay.

RESULTS

The expression level of circNFIX was significantly increased in the bone marrow samples of AML patients and AML cells when compared with normal controls. CircNFIX silencing inhibited AML cell proliferation and promoted apoptosis. Inhibition of miR-876-3p reversed the effect of circNFIX knockdown on AML cell progression. In addition, circNFIX indirectly regulated TRIM31 through miR-876-3p. Further, TRIM31 overexpression counteracted the effect of circNFIX silencing on AML cell proliferation and apoptosis.

CONCLUSION

CircNFIX knockdown could suppress the proliferation and induce the apoptosis of AML cells by targeting the miR-876-3p/TRIM31 axis.

Micro-RNA193a-3p Inhibits Breast Cancer Cell Driven Growth of Vascular Endothelial Cells by Altering Secretome and Inhibiting Mitogenesis: Transcriptomic and Functional Evidence

Breast cancer (BC) cell secretome in the tumor microenvironment (TME) facilitates neo-angiogenesis by promoting vascular endothelial cell (VEC) growth. Drugs that block BC cell growth or angiogenesis can restrict tumor growth and are of clinical relevance. Molecules that can target both BC cell and VEC growth as well as BC secretome may be more effective in treating BC. Since small non-coding microRNAs (miRs) regulate cell growth and miR193a-3p has onco-suppressor activity, we investigated whether miR193a-3p inhibits MCF-7-driven growth (proliferation, migration, capillary formation, signal transduction) of VECs. Using BC cells and VECs grown in monolayers or 3D spheroids and gene microarrays, we demonstrate that: pro-growth effects of MCF-7 and MDA-MB231 conditioned medium (CM) are lost in CM collected from MCF-7/MDA-MB231 cells pre-transfected with miR193a-3p (miR193a-CM). Moreover, miR193a-CM inhibited MAPK and Akt phosphorylation in VECs. In microarray gene expression studies, miR193a-CM upregulated 553 genes and downregulated 543 genes in VECs. Transcriptomic and pathway enrichment analysis of differentially regulated genes revealed downregulation of interferon-associated genes and pathways that induce angiogenesis and BC/tumor growth. An angiogenesis proteome array confirmed the downregulation of 20 pro-angiogenesis proteins by miR193a-CM in VECs. Additionally, in MCF-7 cells and VECs, estradiol (E2) downregulated miR193a-3p expression and induced growth. Ectopic expression of miR193a-3p abrogated the growth stimulatory effects of estradiol E2 and serum in MCF-7 cells and VECs, as well as in MCF-7 and MCF-7+VEC 3D spheroids. Immunostaining of MCF-7+VEC spheroid sections with ki67 showed miR193a-3p inhibits cell proliferation. Taken together, our findings provide first evidence that miR193a-3p abrogates MCF-7-driven growth of VECs by altering MCF-7 secretome and downregulating pro-growth interferon signals and proangiogenic proteins. Additionally, miR193a-3p inhibits serum and E2-induced growth of MCF-7, VECs, and MCF-7+VEC spheroids. In conclusion, miRNA193a-3p can potentially target/inhibit BC tumor angiogenesis via a dual mechanism: (1) altering proangiogenic BC secretome/TME and (2) inhibiting VEC growth. It may represent a therapeutic molecule to target breast tumor growth.

Loss of TRIM31 promotes breast cancer progression through regulating K48- and K63-linked ubiquitination of p53

Breast cancer is the most common cancer in the world. Relapse and metastasis are important factors endangering the life of breast cancer patients, but the mechanism is still unclear. The stabilization of p53 is essential for preventing carcinogenesis, and ubiquitination is one of the main ways to regulate the stability of p53. Tripartite motif-containing 31 (TRIM31) is a new member of the TRIM family and functions as an E3 ubiquitin ligase. It acts as a cancer promoter or suppressor in the malignant processes of multiple cancers. However, the function of TRIM31 in breast cancer progression remains unknown. In this study, we showed that TRIM31 is downregulated in breast cancer tissues and negatively correlated with breast cancer progression. Both gain- and loss-of-function assays indicated that TRIM31 inhibits the proliferation, colony formation, migration, and invasion of breast cancer cells. Further investigation demonstrated that TRIM31 directly interacts with p53, and inducing the K63-linked ubiquitination of p53 via its RING domain, Meanwhile, TRIM31 suppresses the MDM2-mediated K48-linked ubiquitination of p53 through competitive inhibiting the interaction of MDM2 and p53, leading to the p53 stabilization and activation. Knockdown of p53 reversed the inhibitory effects of TRIM31 on the growth and metastasis of breast cancer cells. Moreover, we found that the RING and coiled-coil (C-C) domains of TRIM31 were essential for its tumor suppressor function. Taken together, our findings reveal a novel mechanism by which TRIM31 suppresses breast cancer development through the stabilization and activation of p53 and define a promising therapeutic strategy for restoring TRIM31 to treat breast cancer.

Systems Biomedicine of Primary and Metastatic Colorectal Cancer Reveals Potential Therapeutic Targets

Colorectal cancer (CRC) is one of the major causes of cancer deaths across the world. Patients' survival at time of diagnosis depends mainly on stage of the tumor. Therefore, understanding the molecular mechanisms from low-grade to high-grade stages of cancer that lead to cellular migration from one tissue/organ to another tissue/organ is essential for implementing therapeutic approaches. To this end, we performed a unique meta-analysis flowchart by identifying differentially expressed genes (DEGs) between normal, primary (primary sites), and metastatic samples (Colorectal metastatic lesions in liver and lung) in some Test datasets. DEGs were employed to construct a protein-protein interaction (PPI) network. A smaller network containing 39 DEGs was then extracted from the PPI network whose nodes expression induction or suppression alone or in combination with each other would inhibit tumor progression or metastasis. These DEGs were then verified by gene expression profiling, survival analysis, and multiple Validation datasets. We suggested for the first time that downregulation of mitochondrial genes, including ETHE1, SQOR, TST, and GPX3, would help colorectal cancer cells to produce more energy under hypoxic conditions through mechanisms that are different from "Warburg Effect". Augmentation of given antioxidants and repression of P4HA1 and COL1A2 genes could be a choice of CRC treatment. Moreover, promoting active GSK-3β together with expression control of EIF2B would prevent EMT. We also proposed that OAS1 expression enhancement can induce the anti-cancer effects of interferon-gamma, while suppression of CTSH hinders formation of focal adhesions. ATF5 expression suppression sensitizes cancer cells to anchorage-dependent death signals, while LGALS4 induction recovers cell-cell junctions. These inhibitions and inductions would be another combinatory mechanism that inhibits EMT and cell migration. Furthermore, expression inhibition of TMPO, TOP2A, RFC3, GINS1, and CKS2 genes could prevent tumor growth. Besides, TRIB3 suppression would be a promising target for anti-angiogenic therapy. SORD is a poorly studied enzyme in cancer, found to be upregulated in CRC. Finally, TMEM131 and DARS genes were identified in this study whose roles have never been interrogated in any kind of cancer, neither as a biomarker nor curative target. All the mentioned mechanisms must be further validated by experimental wet-lab techniques.

The translational values of TRIM family in pan-cancers: From functions and mechanisms to clinics

Cancer is the second leading cause of human death across the world. Tripartite motif (TRIM) family, with E3 ubiquitin ligase activities in majority of its members, is reported to be involved in multiple cellular processes and signaling pathways. TRIM proteins have critical effects in the regulation of biological behaviors of cancer cells. Here, we discussed the current understanding of the molecular mechanism of TRIM proteins regulation of cancer cells. We also comprehensively reviewed published studies on TRIM family members as oncogenes or tumor suppressors in the oncogenesis, development, and progression of a variety of types of human cancers. Finally, we highlighted that certain TRIM family members are potential molecular biomarkers for cancer diagnosis and prognosis, and potential therapeutic targets.

TRIM proteins in lung cancer: Mechanisms, biomarkers and therapeutic targets

The tripartite motif (TRIM) family is defined by the presence of a Really Interesting New Gene (RING) domain, one or two B-box motifs and a coiled-coil region. TRIM proteins play key roles in many biological processes, including innate immunity, tumorigenesis, cell differentiation and ontogenetic development. Alterations in TRIM gene and protein levels frequently emerge in a wide range of tumors and affect tumor progression. As canonical E3 ubiquitin ligases, TRIM proteins participate in ubiquitin-dependent proteolysis of prominent components of the p53, NF-κB and PI3K/AKT signaling pathways. The occurrence of ubiquitylation events induced by TRIM proteins sustains internal balance between tumor suppressive and tumor promoting genes. In this review, we summarized the diverse mechanism of TRIM proteins responsible for the most common malignancy, lung cancer. Furthermore, we also discussed recent progress in both the diagnosis and therapeutics of tumors contributed by TRIM proteins.

TRIM31 promotes apoptosis via TAK1-mediated activation of NF-κB signaling in sepsis-induced myocardial dysfunction

Sepsis is a major condition caused by an overwhelming inflammatory response to an infection. Sepsis-induced myocardial dysfunction (SIMD) is a common complication in septic patients and a major predictor of morbidity and mortality. Here, we investigated the role of tripartite motif 31 (TRIM31) protein in sepsis progression in vitro and in vivo. Quantitative real-time PCR and western blot were used to detect the expression levels of relative genes and proteins. Cell proliferation and apoptosis were evaluated to determine cell viability. H&E and IHC staining were performed to examine morphological and pathological changes in mice. ELISA assay was used to detect inflammatory factors. TRIM31 was upregulated in septic patients compared with normal people. TRIM31 depletion reduced LPS-induced apoptosis whereas TRIM31 overexpression-elevated LPS-induced apoptosis. Furthermore, TRIM31 interacted with and ubiquitinated transforming growth factor-β-activated kinase-1 (TAK1), resulting in TAK1 activation and subsequent induction of NF-κB signaling. Of note, Trim31 depletion or blockade by PDTC treatment inhibited LPS-induced apoptosis in vivo. In conclusion, TRIM31 played an important role in SIMD by activating TAK1-mediated NF-κB signaling pathway.

TRIM31 enhances chemoresistance in glioblastoma through activation of the PI3K/Akt signaling pathway

Temozolomide (TMZ) resistance is a complication of treatment of glioma, and new strategies are urgently required to overcome chemoresistance in glioma cells. In the present study, it was demonstrated that tripartite motif-containing 31 (TRIM31) was abnormally upregulated in glioma tissues and cell lines compared with normal samples. Furthermore, the role of TRIM31 was assessed by overexpressing and knocking down its expression. Overexpression of TRIM31 increased cell viability, increased TMZ IC₅₀ values and inhibited apoptosis in A172 and U251 cells; whereas overexpression of TRIM31 decreased the expression of the apoptosis-associated protein p53. Knockdown of TRIM31 increased apoptosis in cells treated with TMZ. Additionally, the mechanisms by which TRIM31 affected glioma cells treated with TMZ were determined. Overexpression of TRIM31 increased phosphorylation of AKT and inhibiting the PI3K/AKT signaling pathway abolished the increase in cell viability and decreased phospho-Akt protein expression in TRIM31 overexpressing A172 cells treated with TMZ. Together, the findings suggest that TRIM31 may be a potentially novel target for glioma chemotherapy.

TRIM31 inhibits NLRP3 inflammasome and pyroptosis of retinal pigment epithelial cells through ubiquitination of NLRP3

NOD-like receptor protein 3 (NLRP3) is associated with age-related macular degeneration (AMD). Retinal pigment epithelial (RPE) cells serve as the immune defense of macula, and their dysfunction causes clinically relevant changes in AMD. In the present study, oxidized low-density lipoprotein (ox-LDL) activated the NLRP3 inflammasome in human RPE cell line ARPE-19. Our data showed that the expression of NLRP3, interleukin-1β (IL-1β), and caspase-1 and the release of IL-1β in ARPE-19 cells were substantially increased by ox-LDL, whereas the addition of NLRP3 inhibitor INF39 dose-dependently reversed the effect of ox-LDL. Overexpression of tripartite motif-containing protein 31 (TRIM31) also suppressed the effect of ox-LDL in ARPE-19 cells. TRIM31 knockdown had similar effects with ox-LDL but INF39 could block the effect of TRIM31 knockdown. Moreover, TRIM31 could interact with NLRP3 in ARPE-19 cells. Overexpression of TRIM31 increased NLRP3 ubiquitination. In conclusion, the results propose that TRIM31 could enhance NLRP3 ubiquitination, therefore inhibiting NLRP3 inflammasome and pyroptosis in human RPE cells.

Integrating germline and somatic genetics to identify genes associated with lung cancer

Genome-wide association studies (GWAS) have successfully identified many genetic variants associated with complex traits. However, GWAS experience power issues, resulting in the failure to detect certain associated variants. Additionally, GWAS are often unable to parse the biological mechanisms of driving associations. An existing gene-based association test framework, Transcriptome-Wide Association Studies (TWAS), leverages expression quantitative trait loci data to increase the power of association tests and illuminate the biological mechanisms by which genetic variants modulate complex traits. We extend the TWAS methodology to incorporate somatic information from tumors. By integrating germline and somatic data we are able to leverage information from the nuanced somatic landscape of tumors. Thus we can augment the power of TWAS-type tests to detect germline genetic variants associated with cancer phenotypes. We use somatic and germline data on lung adenocarcinomas from The Cancer Genome Atlas in conjunction with a meta-analyzed lung cancer GWAS to identify novel genes associated with lung cancer.

The diagnostic performance of lysine(K)-specific demethylase 6B (KDM6B) in non-small cell lung cancer

Objectives: Accumulating evidence show that histone demethylases play important roles in various types of cancers, including non-small cell lung cancer (NSCLC). In the current study, we evaluated the diagnostic value of lysine(K)-specific demethylase 6B (KDM6B) in NSCLC. Methods: Serum KDM6B expression levels of 115 NSCLC patients and 88 healthy volunteers were detected by reverse transcription quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between KDM6B and clinical characteristics was assessed by chi-square test. Receiver operating characteristic (ROC) analysis was applied to evaluate diagnostic efficacy. Results: Serum KDM6B was significantly lower in NSCLC patients than that in healthy controls (p < .001). Moreover, low KDM6B expression was significantly associated with the high clinical stage (p = .028) and positive lymph node metastasis (p = .031). Besides, we found that the expression of KDM6B mRNA was also significantly different among healthy controls, NSCLC early stage and later stage patients (p < .05). ROC curve indicated that KDM6B could serve as a diagnostic marker for NSCLC with the cut-off value of 0.955. The AUC was 0.897 with a sensitivity of 79.5% and specificity of 84.3%. Conclusion: Down-regulation of KDM6B is significantly associated with aggressive progression of NSCLC and KDM6B may be a tool of early detection of NSCLC.

Knockdown Of TRIM31 Enhances Colorectal Cancer Radiosensitivity By Inducing DNA Damage And Activating Apoptosis

Purpose

Biomarkers that predict radiosensitivity are essential for personalized radiotherapy. We performed microarray analysis for rectal cancer patients between those with good response and poor response to preoperative radiotherapy and found that patients with lower expression of tripartite motif-containing protein 31 (TRIM31) showed a better response. In this study, we confirmed the effects of TRIM31 on radiosensitivity by knockdown of TRIM31 in colorectal cancer cells.

Methods and materials

Human colorectal cancer cell lines HT-29 and SW480, which are TRIM31 stably knocked-down, were used for analysis. We studied the level of DNA damage and the change of relative proteins after irradiation in TRIM31-knockdown cells. Flow cytometry was used to test for apoptosis, cell cycle stage, and reactive oxygen species (ROS) levels after irradiation. Cell survival was measured by cloning assay. Proteins related to DNA damage were evaluated by Western blotting.

Results

The percentage of apoptotic cells and the levels of ROS were elevated, and the survival fraction was reduced in TRIM31-knockdown cells. The expression levels of the DNA damage proteins phosphorylated ataxia-telangiectasia mutation (P-ATM), DNA protein kinases (DNA-PKs), and γ-H2AX were higher in TRIM31-knockdown cells.

Conclusion

Knockdown of TRIM31 increases DNA damage and radiosensitivity in colorectal cancer cells.

TRIM31 promotes glioma proliferation and invasion through activating NF-κB pathway

BACKGROUND

Glioma is the most lethal primary brain tumor, the survival rate still isn't improved in the past decades. It's essential to study the regulatory mechanism of glioma progression, hoping to find new therapy targets or methods. The family of tripartite motif (TRIM) containing proteins are E3 ubiquitination ligases, which play critical role in various tumor progression.

METHODS

Cell proliferation and invasion were analyzed by colony formation assay, soft agar growth assay, BrdU incorporation assay and transwell invasion assay. Luciferase reporter analysis was used to analyze NF-κB pathway activity.

RESULTS

We found TRIM31 was upregulated in glioma cells and tissues, its overexpression significantly promoted glioma cell proliferation and invasion, while its knockdown significantly inhibited glioma cell proliferation and invasion. Mechanism analysis found TRIM31 promoted NF-κB pathway activity and increased its targets expression. NF-κB inhibition reversed the phenotype caused by TRIM31, confirming TRIM31 promoted glioma progression through activating NF-κB pathway. Using clinical specimens found TRIM31 expression was positively correlative with NF-κB activity.

CONCLUSION

This study found TRIM31 promoted glioma proliferation and invasion through activating NF-κB activity.

TRIM15 Exerts Anti-Tumor Effects Through Suppressing Cancer Cell Invasion in Gastric Adenocarcinoma

Backgrounds

Recent studies have shown that some members of the tripartite motif-containing protein (TRIM) family function as important regulators in several tumors. However, the clinical significance of TRIM15 in gastric adenocarcinoma has not been elucidated. In the present study, we aimed to examine the expression pattern of TRIM15 and explore whether the TRIM15 expression is correlated with clinicopathological characteristics of patients with gastric adenocarcinoma.

Material/Methods

The expression pattern of TRIM15 was examined in gastric adenocarcinoma tissues and adjacent normal stomach tissues by using immunohistochemistry staining. The prognostic role of TRIM15 in gastric cancer patients was evaluated by univariate and multivariate analyses. Clinical outcomes were assessed by the Kaplan-Meier analysis and log-rank test. The effects of TRIM15 on cancer cell proliferation and invasion were tested through cellular experiments.

Results

TRIM15 was highly expressed in normal stomach tissues compared to tumor tissues. TCGA database showed that higher TRIM15 RNA transcription indicates poorer overall survival of gastric cancer patients. Besides, low expression of TRIM15 was significantly associated with advanced tumor invasion depth and advanced TNM stage. Moreover, gastric cancer patients with lower KDM5B expression had poorer overall survival, and TRIM15 was identified as an independent prognosis factor according to multivariate analysis. Using the gastric cancer cell lines, we found that overexpression of TRIM15 can inhibits tumor cell invasion.

Conclusions

Our study demonstrated that low expression of TRIM15 in gastric adenocarcinoma tissues was significantly associated with poorer prognosis of patients, indicating the potential of TRIM15 as a novel clinical biomarker and therapeutic target.

Oncogenic TRIM31 confers gemcitabine resistance in pancreatic cancer via activating the NF-κB signaling pathway

Background: Drug resistance is well known as a major obstacle for cancer recurrence and treatment failure, leading to poor survival in pancreatic cancer, which is a highly aggressive tumor. Identifying effective strategies to overcome drug resistance would have a significant clinical impact for patients with pancreatic cancer.

Methods: The protein and mRNA expression of TRIM31 in pancreatic cancer cell lines and patient tissues were determined using Real-time PCR and Western blot, respectively. 89 human pancreatic cancer tissue samples were analyzed by IHC to investigate the association between TRIM31 expression and the clinicopathological characteristics of pancreatic cancer patients. Functional assays, such as MTT, FACS, and Tunel assay used to determine the oncogenic role of TRIM31 in human pancreatic cancer progression. Furthermore, western blotting and luciferase assay were used to determine the mechanism of TRIM31 promotes chemoresistance in pancreatic cancer cells.

Results: The expression of TRIM31was markedly upregulated in pancreatic cancer cell lines and tissues, and high TRIM31 expression was associated with an aggressive phenotype and poor prognosis with pancreatic cancer patients. TRIM31 overexpression confers gemcitabine resistance on pancreatic cancer cells; however, inhibition of TRIM31 sensitized pancreatic cancer cell lines to gemcitabine cytotoxicity both in vitro and in vivo. Additionally, TRIM31 upregulated the levels of nuclear p65 by promoting K63-linked polyubiquitination of tumor necrosis factor receptor-associated factor 2 (TRAF2) and sustained the activation of nuclear transcription factor kappa B (NF-κB) in pancreatic cancer cells.

Conclusions: Our findings provided evidence that TRIM31 is a potential therapeutic target for patients with pancreatic cancer. Targeting TRIM31 signaling may be a promising strategy to enhance gemcitabine response during pancreatic cancer chemo-resistance.

Identification of hub genes and pathways associated with bladder cancer based on co-expression network analysis

The aim of the present study was to identify hub genes and signaling pathways associated with bladder cancer (BC) utilizing centrality analysis and pathway enrichment analysis. The differentially expressed genes (DEGs) were screened from the ArrayExpress database between normal subjects and BC patients. Co-expression networks of BC were constructed using differentially co-expressed genes and links, and hub genes were investigated by degree centrality analysis of co-expression networks in BC. The enriched signaling pathways were investigated by Kyoto Encyclopedia of Genes and Genomes database analysis based on the DEGs. The hub gene expression in BC tissues was validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting. A total of 329 DEGs were screened, including 147 upregulated and 182 downregulated genes. The co-expression network constructed between BC and normal controls consisted of 182 nodes and 434 edges, and the two genes in each gene pair were differentially co-expressed genes. Centrality analysis of co-expression networks suggested that the top 5 hub genes with high degree included lectin, galactoside-binding, soluble, 4 (LGALS4), protein tyrosine phosphatase, receptor type N2 (PTPRN2), transmembrane protease, serine 11E (TMPRSS11E), tripartite motif containing 31 (TRIM31) and potassium voltage-gated channel subfamily D member 3 (KCND3). Pathway analysis revealed that the 329 DEGs were significantly enriched in 5 terms (cell cycle, DNA replication, oocyte meiosis, p53 signaling pathway and peroxisome proliferator-activated receptor signaling pathway). According to RT-qPCR and western blot analysis, 4/5 hub genes were significantly expressed, including LGALS4, PTPRN2, TMPRSS11E, TRIM31; however, KCND3 was not significantly expressed. In the present study, 5 hub genes were successfully identified (LGALS4, PTPRN2, TMPRSS11E, TRIM31 and KCND3) and 5 biological pathways that may be underlying biomarkers for early diagnosis and treatment associated with bladder cancer were revealed.

High expression of TRIM11 correlates with poor prognosis in patients with hepatocellular carcinoma

BACKGROUND

Tripartite Motif Containing 11 (TRIM11), a member of TRIM proteins is overexpressed in gliomas and lung cancer. However, the role of TRIM11 in hepatocellular carcinoma (HCC) is unknown.

BASIC PROCEDURES

Herein, we aimed to investigate the expression and clinical significance role of TRIM11 in HCC.

MAIN FINDING

In this study, our data showed significant higher TRIM11 in HCC tissues (n=117) than in the matched non-tumor liver (NTL) tissues (P<0.01). In consistent with above data, we also found TRIM11 protein expression was significantly increased compared with the matched NTL (P<0.01) by immunohistochemistry analysis. Additionally, our results showed that TRIM11 protein expression in HCC tissues was significantly associated with pathological grade (P<0.01), tumor postoperative metastasis (P=0.031), recurrence (P=0.022), and serum a-fetoprotein (AFP) (P<0.01). Moreover, patients' survival was negatively correlated with TRIM11 protein expression. Furthermore, we found that TRIM11 protein was an independent prognostic factor for disease-free (P<0.01) and overall survival (P<0.01) in HCC patients.

PRINCIPAL CONCLUSIONS

Our data showed that TRIM11 expression was significantly elevated in HCC tissues. The overexpression of TRIM11 is closely associated with HCC progression and poor survival of the patients, indicating TRIM11 is a potential therapeutic target for HCC patients.

Expression profiling of TRIM protein family in THP1-derived macrophages following TLR stimulation

Activated macrophages play an important role in many inflammatory diseases including septic shock and atherosclerosis. However, the molecular mechanisms limiting macrophage activation are not completely understood. Members of the tripartite motif (TRIM) family have recently emerged as important players in innate immunity and antivirus. Here, we systematically analyzed mRNA expressions of representative TRIM molecules in human THP1-derived macrophages activated by different toll-like receptor (TLR) ligands. Twenty-nine TRIM members were highly induced (>3 fold) by one or more TLR ligands, among which 19 of them belong to TRIM C-IV subgroup. Besides TRIM21, TRIM22 and TRIM38 were shown to be upregulated by TLR3 and TLR4 ligands as previous reported, we identified a novel group of TRIM genes (TRIM14, 15, 31, 34, 43, 48, 49, 51 and 61) that were significantly up-regulated by TLR3 and TLR4 ligands. In contrast, the expression of TRIM59 was down-regulated by TLR3 and TLR4 ligands in both human and mouse macrophages. The alternations of the TRIM proteins were confirmed by Western blot. Finally, overexpression of TRIM59 significantly suppressed LPS-induced macrophage activation, whereas siRNA-mediated knockdown of TRIM59 enhanced LPS-induced macrophage activation. Taken together, the study provided an insight into the TLR ligands-induced expressions of TRIM family in macrophages.

Downregulation of Foxo3 and TRIM31 by miR-551b in side population promotes cell proliferation, invasion, and drug resistance of ovarian cancer

Ovarian cancer (OVCa) stem cells are associated with tumor growth, metastasis, and recurrence, which are driving forces behind a majority of the OVCa-related mortality. This subpopulation of cancer cells are characterized by uncontrolled proliferation, high invasiveness, and resistance against the current platinum-based therapy. Thus, targeting OVCa cancer stem cells has been focused in recent therapeutic development. Isolation and purification of cancer stem cells are, however, challenging for the lack of sensitive and specific markers. In this study, we demonstrated that miR-551b was upregulated in OVCa stem cells, by using a quantitative PCR array, correlating with the pathological grades of this malignancy. In vitro experiments indicated that miR-551b promoted the proliferation, invasion, and chemoresistance of OVCa cells and cancer stem cells. Further analysis suggested that miR-551b functioned through the suppression of Foxo3 and TRIM31, two important tumor suppressors. In support of this, our in vivo experiments using mouse xenograft models showed that inhibiting miR-551b significantly increased the susceptibility of OVCa cells to cisplatin and prolonged the survival of the host mice. In conclusion, our study suggested miR-551b as a potential biomarker for OVCa stem cells and explored its functional mechanism, providing a potential therapeutic target for future drug development.

TRIM11 overexpression promotes proliferation, migration and invasion of lung cancer cells

BACKGROUND

Tripartite Motif Containing 11 (TRIM11), a member of TRIM proteins, is overexpressed in high-grade gliomas and plays an oncogenic function in glioma biology. However, little is known about the role of TRIM11 in lung cancer.

METHODS

We analyzed TRIM11 mRNA expression in lung cancer tissues and adjacent non-neoplastic tissues by real-time PCR. We then explored the function of TRIM11 in lung cancer cells by small interfering RNA-mediated downregulation of this protein followed by analyses of cell proliferation, migration and invasion.

RESULTS

TRIM11 was highly expressed in lung cancer tissues and lung cancer cell lines. The higher expression of TRIM11 was correlated with the poorer prognosis of patients. Suppressing of TRIM11 expression in lung cancer cells with higher expression of TRIM11 (A549 and NCI-H446 cells) significantly reduced cell growth, motility and invasiveness. We further demonstrated that knockdown of TRIM11 affected the expression of cell proliferation-related proteins (Cyclin D1 and PCNA), and epithelial-mesenchymal transformation-related proteins (VEGF, MMP-2, MMP-9, Twist1, Snail and E-cadherin). The activity of ERK and PI3K/AKT was also suppressed in TRIM11 knocked down cells. Further experiments in lung cells with lower expression of TRIM11 (NCI-H460 and NCI-H1975 cells) with AKT inhibitor suggested that TRIM11 may promote cell motility and invasiveness through AKT pathway.

CONCLUSIONS

Our results indicate that TRIM11 acts as an oncogene in lung cancer through promoting cell growth, migration and invasion. Our findings may have important implication for the detection and treatment of lung cancer.

Differential effects of MTSS1 on invasion and proliferation in subtypes of non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) accounts for >80% of all cases of lung cancer and can be divided into lung adenocarcinoma (LAC), large-cell carcinoma (LCC), and squamous cell carcinoma (SCC). Accumulating evidence suggests that MTSS1, which is a newly discovered protein associated with tumor progression and metastasis, may have differential roles in cancer malignancy. As it has been demonstrated that MTSS1 is overexpressed in NSCLC and may be an independent prognostic factor in patients with SCC, the present study explored the differential roles of MTSS1 in the invasion and proliferation of different subtypes of NSCLC. Stable overexpression and knockdown of MTSS1 was performed in human NSCLC H920 (LAC), H1581 (LCC) and SW900 cell lines (SCC), and western blot, cell invasion, proliferation and FAK activity analyses were used to investigate the effects. Overexpression of MTSS1 enhanced the invasion and proliferation abilities of H920 and H1581 cells, and these effects were abolished by treatment with selective FAK inhibitor 14, which did not affect the expression of MTSS1. Notably, overexpression of MTSS1 inhibited invasion and proliferation in SW900 cells, and this effect was enhanced by the selective FAK inhibitor. Knockdown of MTSS1 decreased the invasion and proliferation abilities of H920 and H1581 cells, whereas knockdown increased invasion and proliferation in SW900 cells. Furthermore, while overexpression of MTSS1 induced FAK phosphorylation and activity in H920 and H1581 cells, MTSS1 overexpression inhibited FAK phosphorylation/activity in SW900 cells. Knockdown of MTSS1 decreased FAK phosphorylation/activity in H920 and H1581 cells, whereas knockdown increased these processes in SW900 cells. To the best of our knowledge, the present study was the first to demonstrate that MTSS1 has differential roles in various subtypes of NSCLC, acting via a FAK-dependent mechanism. The results indicated that MTSS1 may enhance invasion and proliferation in LAC and LCC cells, whereas MTS11 inhibits these processes in SCC cells. These findings provide novel insight into the functional role of MTSS1 in cancer and may help elucidate therapeutic strategies for the treatment of various types of cancer.

Overexpression of Numb suppresses growth, migration, and invasion of human clear cell renal cell carcinoma cells

The objective of the study was to investigate the impact of Numb on cell growth, cell migration, and invasion in human clear cell renal cell carcinoma (ccRCC). Endogenous expression of Numb was evaluated in the ccRCC cell lines (786-O, Caki-1, and Caki-2) and control reference human renal proximal tubular epithelial cells. Numb expression was decreased in the ccRCC cells compared with the control cells (P < 0.01). Then, 786-O and Caki-1 cells described as suitable transfection hosts were used in transfection to carry out biological function studies. The three experimental groups were as follows: Numb-ORF (transfected with Numb-ORF plasmid), blank-vector (transfected with pCMV6-entry), and cell-alone group (no DNA). Numb expression in the Numb-ORF groups was significantly higher than that in the controls (P < 0.01). Cell growth was remarkably reduced (P < 0.01), and the number of migrating or invading cells was reduced (P < 0.01) in the Numb-ORF groups compared with controls. Furthermore, the ratio of G0/G1 phase in the Numb-ORF group of 786-O cells was increased, and the S phase fraction and proliferation index was decreased (P < 0.01). Cyclin D1 and MMP-9 expression was reduced in the Numb-ORF groups compared with controls. Here, we have provided data for attenuated Numb expression in the ccRCC cells. Overexpression of Numb could induce G0/G1 phase arrest and inhibit cell proliferation, migration, and invasion. The suppressive effects might be due to downregulation of cyclin D1 or MMP-9 expression. Taken together, our data suggest that Numb may possibly function as a tumor suppressor involved in the carcinogenesis of ccRCC.

ARNT2 is downregulated and serves as a potential tumor suppressor gene in non-small cell lung cancer

The present study aims to investigate the expression pattern of aryl hydrocarbon receptor nuclear translocator 2 (ARNT2) protein and its clinical significance in human non-small cell lung cancer (NSCLC). We investigated the expression levels of ARNT2 in 104 NSCLC surgical specimens by immunohistochemistry and then analyzed its clinical significance. Additionally, the role of ARNT2 on the biological properties of the NSCLC line HCC827 was experimentally tested in vitro and in vivo to confirm the clinical observations. We found that the expression level of ARNT2 was significantly higher in normal lung tissues compared with NSCLC tissues (P < 0.01). Overall survival (OS) of patients with a high intratumoral ARNT2 level was significantly longer than survival of those with a low ARNT2 level (P = 0.004). In addition, intratumoral ARNT2 expression was an independent prognostic factors for OS (hazard ratio [HR] = 0.529; P = 0.001). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the ARNT2 overexpression inhibited cell viability, while ARNT2 knockdown promoted cell growth in NSCLC cell lines HCC827 and A549. Annexin V/PI assay showed that ARNT2 overexpression increased cell apoptosis, while ARNT2 knockdown decreased cell apoptosis in HCC827 and A549 cells. Moreover, in vivo study showed that attenuated ARNT2 expression in HCC827 cells greatly promoted tumor growth, while overexpressed ARNT2 remarkably inhibited tumor growth in a HCC827 xenograft model. Taken together, our data demonstrate that ARNT2 might serve as a tumor suppressor in NSCLC progression.

Downregulated TIPE2 is associated with poor prognosis and promotes cell proliferation in non-small cell lung cancer

The present study aims to investigate the expression pattern of TIPE2 protein and its clinical significance in human non-small cell lung cancer (NSCLC). We investigated the expression levels of TIPE2 in 96 NSCLC tumor samples by immunohistochemistry and then analyzed its clinical significance. Furthermore, the role of TIPE2 on the biological properties of the NSCLC cell line H1299 and A549 was experimentally tested in vitro and in vivo. We found that the expression level of TIPE2 was significantly higher in normal lung tissues compared with NSCLC tissues (P<0.001), and TIPE2 downregulation was significantly correlated with advanced TNM stage (P=0.006). TIPE2 expression was lower in lung cancer cell lines than normal bronchial cell line HBE. Transfection of TIPE2 plasmid was performed in H1299 and A549 cells. TIPE2 overexpression inhibited lung cancer cell proliferation, colony formation and cell invasive in vitro, and prevented lung tumor growth in vivo. In addition, TIPE2 transfection reduced the anti-apoptotic Bcl-XL protein and mesenchymal marker N-cadherin expression. Taken together, our results demonstrate that TIPE2 might serve as a tumor suppressor in NSCLC progression.