Knockdown of TRIM66 inhibits malignant behavior and epithelial-mesenchymal transition in non-small cell lung cancer

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.

Bromodomain (BrD) Family Members as Regulators of Cancer Stemness-A Comprehensive Review

Epigenetic mechanisms involving DNA methylation and chromatin modifications have emerged as critical facilitators of cancer heterogeneity, substantially affecting cancer development and progression, modulating cell phenotypes, and enhancing or inhibiting cancer cell malignant properties. Not surprisingly, considering the importance of epigenetic regulators in normal stem cell maintenance, many chromatin-related proteins are essential to maintaining the cancer stem cell (CSC)-like state. With increased tumor-initiating capacities and self-renewal potential, CSCs promote tumor growth, provide therapy resistance, spread tumors, and facilitate tumor relapse after treatment. In this review, we characterized the epigenetic mechanisms that regulate the acquisition and maintenance of cancer stemness concerning selected epigenetic factors belonging to the Bromodomain (BrD) family of proteins. An increasing number of BrD proteins reinforce cancer stemness, supporting the maintenance of the cancer stem cell population in vitro and in vivo via the utilization of distinct mechanisms. As bromodomain possesses high druggable potential, specific BrD proteins might become novel therapeutic targets in cancers exhibiting de-differentiated tumor characteristics.

TRIM66 Promotes Malignant Progression of Non-Small-Cell Lung Cancer Cells via Targeting MMP9

Lung cancer has a higher incidence and mortality rate than other cancers, and over 80% of lung cancer cases were classified as non-small-cell lung cancer (NSCLC). TRIM66 is one of the crucial members of TRIM, which has a deep connection with the behavior of various malignant tumors. But it remains uncertain regarding its exact function and underlying mechanism in NSCLC. In our study, qRT-PCR and Western blot were employed to validate that TRIM66 was overexpressed in NSCLC. The migration, invasion, and epithelial-mesenchymal transformation (EMT) progression of NSCLC cells were determined by Western blotting and Transwell experiments after knocking down TRIM66, and it was found that knockdown TRIM66 inhibited the migration, invasion, and EMT processes of NSCLC cells. Next, the binding relationship between TRIM66 and MMP9 was verified by Co-IP assay. After determining the interaction between them, rescue assays showed that overexpression of MMP9 was capable to promote the migration, invasion, and EMT of NSCLC cells. However, the transfection of si-TRIM66 could reverse this facilitating effectiveness. To sum up, we concluded that by targeting MMP9, TRIM66 could exert a cancer-promoting role in the progression of NSCLC cells.

Circ_0051079 silencing inhibits the malignant phenotypes of osteosarcoma cells by the TRIM66/Wnt/β-catenin pathway in a miR-625-5p-dependent manner

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Circ_0051079 was significantly increased in OS tissues and cells.

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Circ_0051079 knockdown inhibited OS cell malignant progression.

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Circ_0051079 regulated TRIM66 expression through miR-625-5p.

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Circ_0051079 mediated the Wnt/β-catenin pathway by regulating TRIM66.

Background

Methods

Results

Conclusion

TRIM66 hastens the malignant progression of non-small cell lung cancer via modulating MMP9-mediated TGF-β/SMAD pathway

OBJECTIVE

To investigate regulatory function and underlying mechanism of TRIM66 in non-small cell lung cancer (NSCLC).

METHODS

TRIM66 and MMP9 expression in NSCLC cells and tissues was assayed via qRT-PCR and western blot. CCK-8, colony formation, Transwell and flow cytometry assays were conducted to measure cell functional alternations in NSCLC. Western blot was employed to measure expression as well as phosphorylation levels of epithelial-mesenchymal transition-(EMT) and TGF-β/SMAD pathways-related proteins. Co-immunoprecipitation (Co-IP) assay was done to probe interaction between TRIM66 and MMP9. Xenograft in vivo experiment and tumor metastasis model in nude mice were utilized to investigate effects of TRIM66 on tumor growth of NSCLC.

RESULTS

TRIM66 and MMP9 were conspicuously highly expressed in NSCLC cells and tissues. High TRIM66 level was markedly correlated with metastasis. Silencing TRIM66 prominently repressed the proliferation, migration and invasion of transfected cells, while inducing cell apoptosis. Whereas forced expression of TRIM66 exerted the opposite effect. The aberrant expression of TRIM66 modulated EMT pathway. TRIM66 also regulated MMP9 expression, and the interaction between them was validated by Co-IP assay. Overexpression of MMP9 could activate TGF-β/SMAD pathway. Rescue experiments manifested that si-MMP9 or SB431542 could partially reverse phenotypes induced by TRIM66. In vivo experiments revealed that silencing TRIM66 could hamper NSCLC tumor growth and metastasis.

CONCLUSION

TRIM66 and MMP9 were up-regulated in NSCLC. TRIM66 facilitated the malignant progression of NSCLC through modulating MMP9-mediated TGF-β/SMAD pathway.

TRIM66 Overexpression Promotes Glioma Progression and Regulates Glucose Uptake Through cMyc/GLUT3 Signaling

OBJECTIVE

Tripartite motif 66 (TRIM66) is reported to be closely associated with human cancers. However, the roles of TRIM66 in glioma remain unclear. The present study aimed to investigate the clinical significance and biological roles of TRIM66 in human glioma.

METHODS

TRIM66 expression in glioma tissues was examined by immunohistochemistry. TRIM66 overexpression and siRNA knockdown were performed in glioblastoma cell lines. CCK8, colony formation assay, transwell assay, Annexin V and JC1 staining, glucose uptake assay, and Western blotting were used to explore the biological roles and potential underlying mechanisms of TRIM66 in glioma progression.

RESULTS

Our results showed that TRIM66 was overexpressed in 52/95 glioma cases. The rates of TRIM66 overexpression in Grade I, Grade II, Grade III, and Grade IV gliomas were 16.6%, 41.3%, 58.6%, and 70.9%, respectively. Oncomine data showed that TRIM66 was upregulated in glioblastoma and oligodendroglioma compared with normal brain tissues. TRIM66 expression was higher in glioblastoma cell lines compared with normal SVG p12 glial cell line. TRIM66 promoted in vitro and in vivo proliferation, invasion, and inhibited temozolomide (TMZ)-induced apoptosis. Notably, TRIM66 increased glucose metabolism by upregulating glucose uptake, glucose consumption, and ATP production. Western blotting showed that TRIM66 positively regulated cMyc and GLUT3. Depletion of cMyc by siRNA abolished the effect of TRIM66 on GLUT3. Chromatin immunoprecipitation (ChIP) assay showed that cMyc could bind to the promoter regions of GLUT3 in glioblastoma cells.

CONCLUSION

TRIM66 was upregulated in human gliomas, where it promoted cell growth and chemoresistance. Our data also identified novel roles of TRIM66 in glioma progression. TRIM66 upregulates glucose uptake and mitochondrial function through the cMyc/GLUT3 signaling, which makes it a potential therapeutic target.

Qi Ling Inhibits Progression of Androgen-Independent Prostate Cancer via Negative Regulation of TRIM66/HP1γ/AR Axis

AIM

This study aimed to understand the molecular mechanism underlying the therapeutic effect of Qi Ling (QL) against androgen-independent prostate cancer.

METHODS

The relative expression of TRIM66 in prostate tumor was interrogated by microarray. Real-time polymerase chain reaction and Western blotting were performed to determine the transcript abundances and protein expressions of TRIM66, HP1γ, AR, c-Myc, and GAPDH. Cell proliferation and apoptosis were analyzed by cell counting kit-8 method and flow cytometry. The regulatory action of c-Myc on TRIM66 was interrogated with luciferase reporter plasmid and the direct binding was demonstrated by chromatin immunoprecipitation. The secretory prostate-specific antigen was quantified by enzyme-linked immunosorbent assay.

RESULTS

TRIM66 was aberrantly overexpressed in prostate cancer and associated with unfavorable prognosis. TRIM66/HP1γ/AR was upregulated during the androgen-independent transition in hormone-deprived medium. The TRIM66 level positively linked to cell proliferation and negatively linked to cell apoptosis in androgen-independent prostate cancer cells. QL treatment specifically inhibited c-Myc and therefore directly downregulated TRIM66 via binding to its promoter. Ectopic introduction of TRIM66 significantly reversed the anti-tumor effects of QL against androgen-independent prostate cancer.

CONCLUSION

Our study uncovered the importance of downregulated TRIM66/HP1γ/AR signaling in mediating the anti-tumor properties of QL.

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.

The Association between TIF1 Family Members and Cancer Stemness in Solid Tumors

Simple Summary

Stem cell-associated molecular features of solid tumors, collectively known as cancer stemness, are of great importance in the development, progression, and reoccurrence of cancer. Transcriptional and epigenetic dysregulation is significantly associated with cancer stemness. Here, we investigated the association between the Transcriptional Intermediary Factor 1 (TIF1) family members and cancer stemness in solid tumors. We aimed to evaluate the potential value of TIF1 members in predicting a stem-like cancer phenotype. Our results indicate that only TIF1β (also known as Tripartite Motif protein 28, TRIM28) high expression is consequently associated with a “stemness high” phenotype, regardless of the tumor type, resulting in a worse prognosis for cancer patients. The oncogenic signature of TRIM28^HIGH tumors significantly reflects the enrichment of “stemness high” cancers with targets for c-Myc (MYC Proto-Oncogene). TRIM28-associated gene expression profiles are also robustly enriched with stemness markers. Our results demonstrate that the association between high TRIM28 expression and an enriched cancer stem cell-like phenotype is a common phenomenon across solid tumors.

Abstract

Cancer progression entails a gradual loss of a differentiated phenotype in parallel with the acquisition of stem cell-like features. Cancer de-differentiation and the acquisition of stemness features are mediated by the transcriptional and epigenetic dysregulation of cancer cells. Here, using publicly available data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases and harnessing several bioinformatic tools, we characterized the association between Transcriptional Intermediary Factor 1 (TIF1) family members and cancer stemness in 27 distinct types of solid tumors. We aimed to define the prognostic value for TIF1 members in predicting a stem cell-like cancer phenotype and patient outcome. Our results demonstrate that high expression of only one member of the TIF1 family, namely TIF1β (also known as Tripartite Motif protein 28, TRIM28) is consequently associated with enriched cancer stemness across the tested solid tumor types, resulting in a worse prognosis for cancer patients. TRIM28 is highly expressed in higher grade tumors that exhibit stem cell-like traits. In contrast to other TIF1 members, only TIF1β/TRIM28-associated gene expression profiles were robustly enriched with stemness markers regardless of the tumor type. Our work demonstrates that TIF1 family members exhibit distinct expression patterns in stem cell-like tumors, despite their structural and functional similarity. Among other TIF1 members, only TRIM28 might serve as a marker of cancer stemness features.

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.

TIF1 Proteins in Genome Stability and Cancer

Genomic instability is a hallmark of cancer cells which results in excessive DNA damage. To counteract this, cells have evolved a tightly regulated DNA damage response (DDR) to rapidly sense DNA damage and promote its repair whilst halting cell cycle progression. The DDR functions predominantly within the context of chromatin and requires the action of chromatin-binding proteins to coordinate the appropriate response. TRIM24, TRIM28, TRIM33 and TRIM66 make up the transcriptional intermediary factor 1 (TIF1) family of chromatin-binding proteins, a subfamily of the large tripartite motif (TRIM) family of E3 ligases. All four TIF1 proteins are aberrantly expressed across numerous cancer types, and increasing evidence suggests that TIF1 family members can function to maintain genome stability by mediating chromatin-based responses to DNA damage. This review provides an overview of the TIF1 family in cancer, focusing on their roles in DNA repair, chromatin regulation and cell cycle regulation.

TRIM66 promotes malignant progression of prostate carcinoma through the JAK/STAT pathway

Prostate cancer is the fifth leading cause of cancer‐related deaths in males globally. Tripartite Motif Containing 66 (TRIM66) functions as transcriptional repressor and exerts its effect at least partially through promotion of deacetylase. TRIM66 has been previously reported to play an oncogenic role in a number of human cancers. Here, we investigated the potential oncogenic properties of TRIM66 in prostate cancer. We report that shRNA‐mediated knockdown of TRIM66 significantly suppressed viability and proliferation of both PC‐3 and DU145 prostate cancer cell lines. Furthermore, TRIM66 deficiency inhibited migration and invasion of prostate cancer cells. Mechanistically, TRIM66 positively regulated signal transducer and activator of transcription 2 (STAT2) and interleukin‐2 (IL‐2) expression. The predominance of STAT2–IL‐2 in mediating the oncogenic properties of TRIM66 was determined using a rescue assay, wherein overexpression of either STAT2 or IL‐2 almost completely abolished the inhibitory effects on cell proliferation, migration and invasion elicited by TRIM66 deficiency in prostate cancer cells. Our study highlights the importance of the TRIM66–STAT2–IL‐2 signaling axis in the tumor biology of prostate cancer.

miR-451a Inhibits the Growth and Invasion of Osteosarcoma via Targeting TRIM66

The importance of microRNAs in regulating osteosarcoma development has been studied in recent years. However, the function of microRNA-451a in osteosarcoma growth is rarely investigated. Here, we explored the expression of microRNA-451a in osteosarcoma cell lines. Bioinformatic software, luciferase activity reporter assay, and Western blot were conducted to determine the association between microRNA-451a and tripartite motif-containing 66. Cell Counting Kit-8 assay and transwell assay were used to explore the regulatory effects of microRNA-451a on osteosarcoma cells. Moreover, we explored whether microRNA-451a modulates osteosarcoma cell biological activity by regulating tripartite motif-containing 66. The expression of microRNA-451a was found to be downregulated in osteosarcoma and negatively regulated the expression of tripartite motif-containing 66. Tripartite motif-containing 66 was further validated as a target of microRNA-451a. MicroRNA-451a inhibits the growth and invasion of osteosarcoma cell lines through targeting tripartite motif-containing 66. The miR-451a targets tripartite motif-containing 66 may provide novel therapeutic targets for the treatment of osteosarcoma.

TRIM59 as a novel molecular biomarker to predict the prognosis of patients with NSCLC

As a member of the tripartite motif family, tripartite motif-containing protein 59 (TRIM59) serves as an E3 ubiquitin ligase in various cellular processes, including intracellular signaling, development, apoptosis, protein quality control, innate immunity, autophagy and carcinogenesis. The present study aimed to investigate the expression and prognostic value of TRIM59 in patients with non-small cell lung cancer (NSCLC). Expression of TRIM59 in patients with NSCLC was measured by immunohistochemistry in tissue microarrays. Datasets from The Cancer Genome Atlas (TCGA) were used to further verify the expression level of TRIM59 in NSCLC, lung adenocarcinoma and lung squamous cell carcinoma (LUSC). The prognostic value of TRIM59 in NSCLC was also analyzed. Immunohistochemistry revealed that TRIM59 was primarily located in the cytoplasm of tumor cells. Analysis of TCGA datasets revealed that TRIM59 was more highly expressed in tumor tissues than in normal tissues (P<0.0001). Furthermore, the TRIM59 expression level was associated with tumor differentiation (P=0.012), while no association was observed between TRIM59 expression and any other clinicopathological parameters. However, the average overall survival rate of patients with NSCLC in the high TRIM59 expression group was significantly lower than that in the low expression group (P=0.014), especially in patients with LUSC (P=0.016) and patients with poor differentiation (P=0.033). The multivariate analysis indicated that high TRIM59 expression is an independent prognostic factor in patients with NSCLC (P=0.018) and was associated with poor prognosis in patients with NSCLC. Therefore, TRIM59 may serve as a novel molecular biomarker to predict the prognosis of patients with NSCLC.

Knockdown of TRIM66 inhibits cell proliferation, migration and invasion in colorectal cancer through JAK2/STAT3 pathway

Colorectal cancer (CRC) is one of the most common malignancies in the world. Emerging evidence has shown that dysregulation of tripartite motif (TRIM) family proteins is strongly correlated with the tumorigenesis of CRC. Here, we evaluated the biological roles of TRIM66, a member of TRIM family, in the progression of CRC. The results demonstrated that TRIM66 was markedly up-regulated in both CRC tissues and cell lines. To further investigate the functions of TRIM66 in CRC, CRC cells were infected with lentivirus expressing anti-TRIM66 shRNA (sh-TRIM66) or control lentivirus (sh-con). We found that knockdown of TRIM66 significantly inhibited cell proliferation, migration, invasion of CRC cells. TRIM66 knockdown also suppressed epithelial-mesenchymal transition (EMT), as proved by the increased E-cadherin expression and decreased expressions of N-cadherin and vimentin. Furthermore, TRIM66 knockdown markedly inhibited tumor growth in a mouse xenograft model. Knockdown of TRIM66 reduced the activation of JAK2/STAT3 signaling pathway in CRC cells. Treatment with AG490, an inhibitor of JAK2/STAT3 signaling pathway, enhanced the inhibitory effects of TRIM66 knockdown on cell proliferation, migration and invasion. These findings suggested that knockdown of TRIM66 exhibited anti-tumor activity through inhibiting the JAK2/STAT3 signaling pathway in CRC cells.

E3 Ubiquitin Ligase TRIM Proteins, Cell Cycle and Mitosis

The cell cycle is a series of events by which cellular components are accurately segregated into daughter cells, principally controlled by the oscillating activities of cyclin-dependent kinases (CDKs) and their co-activators. In eukaryotes, DNA replication is confined to a discrete synthesis phase while chromosome segregation occurs during mitosis. During mitosis, the chromosomes are pulled into each of the two daughter cells by the coordination of spindle microtubules, kinetochores, centromeres, and chromatin. These four functional units tie chromosomes to the microtubules, send signals to the cells when the attachment is completed and the division can proceed, and withstand the force generated by pulling the chromosomes to either daughter cell. Protein ubiquitination is a post-translational modification that plays a central role in cellular homeostasis. E3 ubiquitin ligases mediate the transfer of ubiquitin to substrate proteins determining their fate. One of the largest subfamilies of E3 ubiquitin ligases is the family of the tripartite motif (TRIM) proteins, whose dysregulation is associated with a variety of cellular processes and directly involved in human diseases and cancer. In this review we summarize the current knowledge and emerging concepts about TRIMs and their contribution to the correct regulation of cell cycle, describing how TRIMs control the cell cycle transition phases and their involvement in the different functional units of the mitotic process, along with implications in cancer progression.

Bioinformatics analysis of prognostic value of TRIM13 gene in breast cancer

Background: Tripartite motif 13 (TRIM13) plays a significant role in various biological processes including cell growth, apoptosis, transcriptional regulation, and carcinogenesis. However, the prognostic significance of TRIM13 gene in breast cancer treatment remains largely unclear. Methods: We performed a bioinformatics analysis of the clinical parameters and survival data as it relates to TRIM13 in breast cancer patients using several online databases including Oncomine, bcGenExMiner, PrognoScan, and UCSC Xena. Results: We found that TRIM13 was lower-expressed in different subtypes of breast cancer with respect to normal tissues. Estrogen receptor and progesterone receptor status were positively correlated with TRIM13 level; whereas, the Scarff–Bloom–Richardson grade, Nottingham prognostic index, nodal status, basal-like status, and triple-negative status were negatively related to TRIM13 expression in breast cancer patients with respect to normal individuals. Lower TRIM13 expression correlated with worse distant metastasis free survival, relapse free survival, disease specific survival, and metastatic relapse free survival. We also confirmed a positive correlation between TRIM13 and RAB11FIP2 gene expression. Conclusion: Bioinformatics analysis revealed that TRIM13 may be adopted as a promising predictive biomarker for prognosis of breast cancer. More in-depth experiments and clinical trials are needed to validate the value of TRIM13 in breast cancer treatment.