TRIM14 promotes the migration and invasion of gastric cancer by regulating epithelial‑to‑mesenchymal transition via activation of AKT signaling regulated by miR‑195‑5p

Emerging discoveries on the role of TRIM14: from diseases to immune regulation

TRIM14 is an important member of the TRIM family and is widely expressed in a variety of tissues. Like other members of the TRIM family, TRIM14 is also involved in ubiquitination modifications. TRIM14 was initially reported as an interferon-stimulated gene (ISG). In recent years, many studies have focused on the regulatory role of TRIM14 in signaling pathways such as the PI3K/Akt, NF-κB, and cGAS/STING pathways and revealed its mechanism of action in a variety of pathophysiological processes, and the regulation of TRIM14 has attracted the interest of many researchers as a new direction for the treatment of various diseases. However, there are no reviews on the role of TRIM14 in diseases. In this paper, we will describe the structure of TRIM14, review its role in cancer, cardiovascular disease, cervical spondylosis, inflammation and antiviral immunity, and provide an outlook on future research directions.

The Role and Mechanism of TRIM Proteins in Gastric Cancer

Tripartite motif (TRIM) family proteins, distinguished by their N-terminal region that includes a Really Interesting New Gene (RING) domain with E3 ligase activity, two B-box domains, and a coiled-coil region, have been recognized as significant contributors in carcinogenesis, primarily via the ubiquitin-proteasome system (UPS) for degrading proteins. Mechanistically, these proteins modulate a variety of signaling pathways, including Wnt/β-catenin, PI3K/AKT, and TGF-β/Smad, contributing to cellular regulation, and also impact cellular activities through non-signaling mechanisms, including modulation of gene transcription, protein degradation, and stability via protein-protein interactions. Currently, growing evidence indicates that TRIM proteins emerge as potential regulators in gastric cancer, exhibiting both tumor-suppressive and oncogenic roles. Given their critical involvement in cellular processes and the notable challenges of gastric cancer, exploring the specific contributions of TRIM proteins to this disease is necessary. Consequently, this review elucidates the roles and mechanisms of TRIM proteins in gastric cancer, emphasizing their potential as therapeutic targets and prognostic factors.

Exploring the Mechanisms, Biomarkers, and Therapeutic Targets of TRIM Family in Gastrointestinal Cancer

Gastrointestinal region (GI) cancers are closely linked to the ubiquitination system, with the E3 ubiquitin ligase playing a crucial role by targeting various substrates. As E3 ubiquitin ligases, proteins of tripartite motif (TRIM) family play a role in cancer signaling, development, apoptosis, and formation. These proteins regulate diverse biological activities and signaling pathways. This study comprehensively outlines the functions of TRIM proteins in gastrointestinal physiology, contributing to our knowledge of the molecular pathways involved in gastrointestinal tumors. Gastrointestinal region (GI) cancers are closely linked to the ubiquitination system, with the E3 ubiquitin ligase playing a crucial role by targeting various substrates.

The Multifunction of TRIM26: From Immune Regulation to Oncology

Ubiquitination, a crucial post-translational modification, plays a role in nearly all physiological processes. Its functional execution depends on a series of catalytic reactions involving numerous proteases. TRIM26, a protein belonging to the TRIM family, exhibits E3 ubiquitin ligase activity because of its RING structural domain, and is present in diverse cell lineages. Over the last few decades, TRIM26 has been documented to engage in numerous physiological and pathological processes as a controller, demonstrating a diverse array of biological roles. Despite the growing research interest in TRIM26, there has been limited attention given to examining the protein's structure and function in existing reviews. This review begins with a concise overview of the composition and positioning of TRIM26 and then proceeds to examine its roles in immune response, viral invasion, and inflammatory processes. Simultaneously, we demonstrate the contribution of TRIM26 to the progression of various diseases, encompassing numerous malignancies and neurologic conditions. Finally, we have investigated the potential areas for future research on TRIM26.

Tripartite motif‑containing 14 may aggravate cardiac hypertrophy via the AKT signalling pathway in neonatal rat cardiomyocytes and transgenic mice

Tripartite motif‑containing 14 (TRIM14) is an E3 ubiquitin ligase that primarily participates in the natural immune response and in tumour development via ubiquitination. However, the role of TRIM14 in cardiac hypertrophy is not currently clear. The present study examined the role of TRIM14 in cardiac hypertrophy and its potential molecular mechanism. TRIM14 was overexpressed in neonatal rat cardiomyocytes using adenovirus and cardiomyocyte hypertrophy was induced using phenylephrine (PE). Cardiomyocyte hypertrophy was assessed by measuring cardiomyocyte surface area and markers of hypertrophy. In addition, TRIM14‑transgenic (TRIM14‑TG) mice were created and cardiac hypertrophy was induced using transverse aortic constriction (TAC). Cardiac function, heart weight‑to‑body weight ratio (HW/BW), cardiomyocyte cross‑sectional area, cardiac fibrosis and hypertrophic markers were further examined. The expression of AKT signalling pathway‑related proteins was detected. TRIM14 overexpression in cardiomyocytes promoted PE‑induced increases in cardiomyocyte surface area and hypertrophic markers. TRIM14‑TG mice developed worse cardiac function, greater HW/BW, cross‑sectional area and cardiac fibrosis, and higher levels of hypertrophic markers in response to TAC. TRIM14 overexpression also increased the phosphorylation levels of AKT, GSK‑3β, mTOR and p70S6K in vivo and in vitro. To the best our knowledge, the present study was the first to reveal that overexpression of TRIM14 aggravated cardiac hypertrophy in vivo and in vitro, which may be related to activation of the AKT signalling pathway.

UPS: Opportunities and challenges for gastric cancer treatment

Gastric cancer remains the fourth most frequently diagnosed malignancy and the fifth leading cause of cancer-related mortality worldwide owning to the lack of efficient drugs and targets for therapy. Accumulating evidence indicates that UPS, which consists of E1, E2, and E3 enzymes and proteasome, plays an important role in the GC tumorigenesis. The imbalance of UPS impairs the protein homeostasis network during development of GC. Therefore, modulating these enzymes and proteasome may be a promising strategy for GC target therapy. Besides, PROTAC, a strategy using UPS to degrade the target protein, is an emerging tool for drug development. Thus far, more and more PROTAC drugs enter clinical trials for cancer therapy. Here, we will analyze the abnormal expression enzymes in UPS and summarize the E3 enzymes which can be developed in PROTAC so that it can contribute to the development of UPS modulator and PROTAC technology for GC therapy.

E3 ubiquitin ligase TRIM55 promotes metastasis of gastric cancer cells by mediating epithelial-mesenchymal transition

BACKGROUND

Gastric cancer (GC) is considered a major global health problem. The role of TRIM55, a member of the three-domain protein family, in GC is unknown.

AIM

To determine the expression of TRIM55 in GC tissues and its relationship with clinicopathological characteristics, and to investigate the effects of TRIM55 on the malignant biological behavior of GC cells.

METHODS

Differential expression of TRIM55 in GC and para-cancer tissues was detected by immunohistochemistry, and the relationship between TRIM55 level and clinicopathological characteristics and prognosis was analyzed. Gain-of-function, loss-of-function, cell counting kit-8 assay, colony formation, transwell assay, wound healing assay, and western blot analysis were used to assess the potential role of TRIM55 in the development of GC.

RESULTS

TRIM55 expression was significantly increased in GC tissues compared with adjacent normal tissues. High expression of TRIM55 was associated with advanced pathological stage and poor prognosis. Overexpression of TRIM55 promoted invasion and metastasis of GC cells in vitro by regulating epithelial-mesenchymal transition (EMT), whereas knockdown of TRIM55 had the opposite effect. Our data showed that TRIM55 is highly expressed in GC tissues, and is associated with poor prognosis. TRIM55 plays the role of an oncogene in GC, and it promotes metastasis of GC through the regulation of EMT.

CONCLUSION

TRIM55 may be a possible target for the diagnosis and prognosis of GC patients.

Tumor suppressor DEAR1 regulates mammary epithelial cell fate and predicts early onset and metastasis in triple negative breast cancer

Triple negative breast cancer (TNBC) is a disease of poor prognosis, with the majority classified as the basal-like subtype associated with epithelial-mesenchymal transition and metastasis. Because basal breast cancers originate from proliferative luminal progenitor-like cells upon dysregulation of proper luminal differentiation, genes regulating luminal-basal transition are critical to elucidate novel therapeutic targets to improve TNBC outcomes. Herein we demonstrate that the tumor suppressor DEAR1/TRIM62 is a critical regulator of luminal cell fate. DEAR1 loss in human mammary epithelial cells results in significantly enhanced mammosphere formation that is accelerated in the presence of TGF-β/SMAD3 signaling. Mammospheres formed following DEAR1 loss are enriched for ALDH1A1 and CK5 expression, EpCAM^-/CD49f⁺ and CD44^high/24^low basal-like epithelial cells, indicating that DEAR1 regulates stem/progenitor cell properties and luminal-basal progenitor transition. We show that DEAR1 maintains luminal differentiation as a novel ubiquitin ligase for SNAI2/SLUG, a master regulator driving stemness and generation of basal-like progenitor populations. We also identify a significant inverse correlation between DEAR1 and SNAI2 expression in a 103 TNBC case cohort and show that low DEAR1 expression significantly correlates with young age of onset and shorter time to metastasis, suggesting DEAR1 could serve as a biomarker to stratify early onset TNBCs for targeted stem cell therapies.

TRIM family contribute to tumorigenesis, cancer development, and drug resistance

The tripartite-motif (TRIM) family represents one of the largest classes of putative single protein RING-finger E3 ubiquitin ligases. TRIM family is involved in a variety of cellular signaling transductions and biological processes. TRIM family also contributes to cancer initiation, progress, and therapy resistance, exhibiting oncogenic and tumor-suppressive functions in different human cancer types. Moreover, TRIM family members have great potential to serve as biomarkers for cancer diagnosis and prognosis. In this review, we focus on the specific mechanisms of the participation of TRIM family members in tumorigenesis, and cancer development including interacting with dysregulated signaling pathways such as JAK/STAT, PI3K/AKT, TGF-β, NF-κB, Wnt/β-catenin, and p53 hub. In addition, many studies have demonstrated that the TRIM family are related to tumor resistance; modulate the epithelial–mesenchymal transition (EMT) process, and guarantee the acquisition of cancer stem cells (CSCs) phenotype. In the end, we havediscussed the potential of TRIM family members for cancer therapeutic targets.

Long non-coding RNA SNHG1/microRNA-195-5p/Yes-associated protein axis affects the proliferation and metastasis of gastric cancer via the Hippo signaling pathway

Long non-coding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) has been found to be highly expressed in gastric cancer (GC). However, the study for exploring the effects of SNHG1 and microRNA (miR)-195-5p on GC is limited. This research commits to unravel the regulatory effects of SNHG1, miRNA-195-5p, and Yes-associated protein 1 (YAP1) on GC. SNHG1, miR-195-5p and YAP1 levels in GC tissues and GC cells were detected. The GC cells were treated with various constructs altering SNHG1 or miR-195-5p expression to determine the biological activities of GC cell in vitro. The effect of SNHG1 inhibition on subcutaneous tumorigenesis of GC cells in a nude mouse model in vivo was detected. The binding relation among SNHG1, miR-195-5p, and YAP1 was validated. SNHG1 and YAP1 levels were elevated and miR-195-5p level was reduced in GC. Reduction of SNHG1 or elevation of miR-195-5p retarded GC cell biological activity in vitro. Downregulated SNHG1 suppressed tumor growth in vivo. SNHG1 bound to miR-195-5p, and miR-195-5p directly targeted YAP1. The downregulated SNHG1 hinders the biological behaviors of GC cells via the modulation of the miR-195-5p/YAP1 axis.

TRIM3 and TRIM16 as potential tumor suppressors in breast cancer patients

Objective

Breast cancer is the leading cause of death among women in many countries. Numerous factors serve as oncogenes or tumor suppressors in breast cancer. The large family of Tripartite-motif (TRIM) proteins with ~ 80 members has drawn attention for their role in cancer. TRIM3 and TRIM16 have shown suppressive activity in different cancers. This study aimed to evaluate the expression of TRIM3 and TRIM16 in cancerous and normal breast samples and to investigate their association with different clinical and pathological parameters.

Results

qRT-PCR was utilized to determine the gene expression of TRIM3 and TRIM16. The expression of TRIM3 and TRIM16 genes in tumor samples were significantly reduced to 0.45 and 0.29 fold, respectively. TRIM3 and TRIM16 genes expression were both positively correlated with the invasion of breast cancer. TRIM3 gene expression was associated with tumors’ histological grade. However, no significant association was found between the expression of the genes and tumor size, stage and necrosis. The expression of TRIM3 and TRIM16 are significantly reduced in breast cancer tissues. Besides, the expression of both TRIM3 and TRIM16 genes significantly plummet in lymphatic/vascular and perineural invasive samples. Hence, we suggest a potential tumor suppressor role for TRIM3 and TRIM16 in breast cancer.

Effects of mir-195 Targeted Regulation of JAK2 on Proliferation, Invasion, and Apoptosis of Gastric Cancer Cells

Background. Overexpression of miR-195 can make gastric cancer cells stay in G1/G2 phase. miR-195 has been shown to inhibit gastric cancer cell replication and accelerate cell death by targeting JAK2. However, the relationship between miR-195, JAK2, and gastric cancer is not clear. Objective. To observe the effect of mir-195 regulated by JAK2 on the growth, invasion, and death of gastric cancer cells. Methods. MGC803 and NCI gastric N87 cells were introduced into the negative control sequences of miR-195 and RNA, respectively. To detect the expression of miR-195 in cells, to detect the effect of miR-195 on mitosis and proliferation of tumor cells, to analyze the effect of miR-195 on cell invasion and metastasis, and to detect the regulation of miR-195 on JAK2 expression. Results. The level of miR-195 in miR-195-MIMICS group was significantly higher than that in miR-NC group. The cell survival rate of miR-195 mimic group was lower than that of miR-NC group ( $P<0.05$ ). Compared with miR-NC group, the number of cells in G1 phase increased, the cells in G2 phase and S phase decreased, and the proportion of cells in G2 and S phase decreased in miR-195 mimic group. The scratch distance of miR-195 simulator group was larger than that of control group. The number of invasive cells in the miR-195 mimic group was significantly lower than that in the control group. The expression of JAK2 protein in miR-195 mimic group was lower than that in miR-NC group. There was a significant negative correlation between the expression level of miR-195 and JAK2 (rhabdomile 0.326 and record 0.00). There are continuous interaction fragments between JAK2 and miR-195. The luciferase activity of miR-195 mimic and wild type JAK2 sequence expression vector was significantly lower than that of wild type JAK2 sequence expression vector. Conclusion. miR-195 may inhibit the occurrence, metastasis, and invasion of gastric tumor by downregulating the expression of JAK2. miR-195/JAK2 may be a new molecular target for the treatment of gastrointestinal tumors.

Hypoxia-Induced Upregulation of lncRNA ELFN1-AS1 Promotes Colon Cancer Growth and Metastasis Through Targeting TRIM14 via Sponging miR-191-5p

Hypoxia is identified as one of the microenvironmental features of most solid tumors and is involved in tumor progression. In the present research, we demonstrate that lncRNA extracellular leucine rich repeat and fibronectin type III domain-containing 1-antisense RNA 1 (ELFN1-AS1) is upregulated by hypoxia in colon cancer cells. Knockdown of ELFN1-AS1 in hypoxic colon cancer cells can reduce cell proliferation and restore the invasion to non-hypoxic levels. Fluorescence in situ hybridization results show that ELFN1-AS1 is distributed in the cytoplasm of colon cancer cells, so we further analyze the potential targets for ELFN1-AS1 as a competing endogenous RNA (ceRNA). MiR-191-5p contains a binding sequence with ELFN1-AS1 and is downregulated by ELFN1-AS1 in colon cancer cells. Then, there is a binding site between miR-191-5p and the 3′ untranslated region of tripartite motif TRIM 14 (TRIM14). The expression of TRIM14 is inhibited by ELFN1-AS1 siRNA or miR-191-5p mimics in LoVo and HT29 cells. The treatment of the miR-191-5p inhibitor in ELFN1-AS1 knockdown cells can significantly increase cell proliferation and invasion ability. Overexpression of TRIM14 in miR-191-5p-mimic-treated cells can rescue the inhibition of proliferation and invasion caused by miR-191-5p mimics. In conclusion, ELFN1-AS1 operates as a downstream target of hypoxia, promotes proliferation and invasion, and inhibits apoptosis through upregulating TRIM14 by sponging miR-191-5p in the colon cancer cells. Our results enrich our understanding of colon cancer progression and provide potential targets for clinical treatment of colon cancer.

Hsa_circ_0060927 Is a Novel Tumor Biomarker by Sponging miR-195-5p in the Malignant Transformation of OLK to OSCC

OBJECTIVE

To investigate the clinical significance of differentially expressed circRNAs and candidate circRNAs in the transformation of oral leukoplakia (OLK) to oral squamous cell carcinoma (OSCC).

METHODS

We performed high-throughput circRNA sequencing in six cases of normal oral mucosal (NOM) tissues, six cases of OLK tissues, and six cases of OSCC tissues. Ten circRNAs with significant differential expression were verified by qRT-PCR. Enzyme tolerance assay and Sanger sequencing were performed on the screened target circRNA hsa_circ_0060927, and a qRT-PCR assay of hsa_circ_0060927 was performed in three tissues (24 cases in each group); this was followed by an ROC analysis. The ceRNA network was predicted using TargetScan and miRanda. MiR-195-5p and TRIM14 were selected as the downstream research objects of hsa_circ_0060927. The sponge mechanism of hsa_circ_0060927 was detected by AGO2 RIP. The interaction between hsa_circ_0060927 and miR-195-5p was verified by RNA pull-down assay and dual luciferase reporter gene assay. The expressions of hsa_circ_0060927, miR-195-5p, and TRIM14 were verified by normal oral epithelial primary cells and cell lines of LEUK1, SCC9, and SCC25. The hsa_circ_0060927 overexpressed plasmid and miR-195-5p mimics were constructed to transfection LEUK1 to detect the changes in cell proliferation, apoptosis, and migration.

RESULTS

The results of qRT-PCR validation were consistent with the sequencing results. Hsa_circ_0060927 is a true circRNA with trans-splicing sites. The expression of hsa_circ_0060927 increased in NOM, OLK, and OSCC. Overexpression of hsa_circ_0060927 enhanced the ability of cell proliferation and migration, and decreased cell apoptosis capacity. The prediction of ceRNA network suggested that hsa_circ_0060927 could regulate the target gene TRIM14 through sponging miR-195-5p. AGO2 RIP indicated that hsa_circ_0060927 had a sponge mechanism. RNA pull-down and dual luciferase reporter gene assay suggested that hsa_circ_0060927 interacted with miR-195-5p. Hsa_circ_0060927 was positively correlated with the expression of TRIM14, and could relieve the inhibition of miR-195-5p on TRIM14 to regulate cell proliferation, apoptosis, and migration of LEUK1 cells.

CONCLUSION

Hsa_circ_0060927 acted as a potential key ceRNA to sponge downstream miR-195-5p and promote OLK carcinogenesis by upregulating TRIM14. Hsa_circ_0060927 was expected to be a molecular marker for the prevention and treatment of OLK carcinogenesis through the hsa_circ_0060927/miR-195-5p/TRIM14 axis.

Human mesenchymal stem cells derived exosomes inhibit the growth of acute myeloid leukemia cells via regulating miR-23b-5p/TRIM14 pathway

Background

Acute myeloid leukemia (AML) is a malignancy commonly seen in adults. Previous studies indicated that TRIM14 played a tumorigenic role in various types of cancer and miR-23b-5p was down-regulated in human mesenchymal stem cell-derived exosomes (HMSC-exos) of AML patients. However, their roles in AML remains unclear. Our study aims to investigate the role of TRIM14 and miR-23b-5p in the pathogenesis of AML.

Materials and methods

The blood specimen was collected from de novo AML patients and healthy donators. Exosomes were extracted from the culture medium of human mesenchymal stem cells under ultracentrifugation. Then exosomes were co-cultured with AML cells to determine the effect of their contents. The cell proliferation was detected by cell counting kit-8 assay, whereas the cell apoptosis was detected by flow cytometry. The expression of miR-23b-5p and TRIM14 was silenced or overexpressed to explore their biological functions in AML. Luciferase reporter assay was conducted to validate the interaction between miR-23b-5p and TRIM14. Gene expression was determined by quantitative real-time PCR and immunoblots.

Results

TRIM14 was significantly increased in AML patients and cell lines. The inhibition of TRIM14 significantly reduced the proliferation and induced the apoptosis of AML cells via activating PI3K/AKT pathway, whereas its overexpression exhibited reversed effects. HMSC-exos could suppress the proliferation of AML cells through the delivery of miR-23b-5p. Moreover, miR-23b-5p inhibited the transcription of TRIM14 by binding on its 3’UTR region. Overexpression of TRIM14 exhibited reversed effect against the function of miR-23b-5p mimic.

Conclusion

TRIM14 could promote the proliferation of AML cells via activating PI3K/AKT pathway, which was reversed by HMSC-exos through delivering miR-23b-5p. These findings indicated that miR-23b-5p and TRIM14 could be applied as potential targets for the treatment of AML.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00393-1.

The TRIM proteins in cancer: from expression to emerging regulatory mechanisms

New clinical evidence suggests that dysregulation of the ubiquitin-mediated destruction of tumor suppressors or oncogene products is probably engaged in the etiology of leukemia and carcinoma. The superfamily of tripartite motif (TRIM)-containing protein family is among the biggest recognized single protein RING finger E3 ubiquitin ligases that are considered vital carcinogenesis regulators, which is not shocking since TRIM proteins are engaged in various biological processes, including cell growth, development, and differentiation; hence, TRIM proteins' alterations may influence apoptosis, cell proliferation, and transcriptional regulation. In this review article, the various mechanisms through which TRIM proteins exert their role in the most prevalent malignancies including lung, prostate, colorectal, liver, breast, brain cancer, and leukemia are summarized.

TRIM14 regulates melanoma malignancy via PTEN/PI3K/AKT and STAT3 pathways

Melanoma is one of the most aggressive cancers with poor overall survival. To date, there are still few effective methods for the treatment of melanoma. TRIM14 was previously reported to be an important oncogene in many tumors. Nevertheless, the roles of TRIM14 in melanoma remain unknown. In this study, we found that TRIM14 was abnormally upregulated in melanoma cell lines. Knockdown of TRIM14 suppressed melanoma cell proliferation, migration, invasion, epithelial-mesenchymal transition, and melanin synthesis. Overexpression of TRIM14 had opposite effects on the cellular functions of melanoma cell lines. Further study revealed that TRIM14 knockdown increased PTEN protein levels, which in turn inactivated AKT and STAT3 pathways. Moreover, blocking AKT or STAT3 pathway with a specific inhibitor could partially reverse the promotion of melanoma malignancy mediated by TRIM14 overexpression. In addition, in vivo assay also supported the above findings. These results indicated that TRIM14 might be a promising target for melanoma treatment.

TRIM Proteins in Colorectal Cancer: TRIM8 as a Promising Therapeutic Target in Chemo Resistance

Colorectal cancer (CRC) represents one of the most widespread forms of cancer in the population and, as all malignant tumors, often develops resistance to chemotherapies with consequent tumor growth and spreading leading to the patient’s premature death. For this reason, a great challenge is to identify new therapeutic targets, able to restore the drugs sensitivity of cancer cells. In this review, we discuss the role of TRIpartite Motifs (TRIM) proteins in cancers and in CRC chemoresistance, focusing on the tumor-suppressor role of TRIM8 protein in the reactivation of the CRC cells sensitivity to drugs currently used in the clinical practice. Since the restoration of TRIM8 protein levels in CRC cells recovers chemotherapy response, it may represent a new promising therapeutic target in the treatment of CRC.

Roles of E3 ubiquitin ligases in gastric cancer carcinogenesis and their effects on cisplatin resistance

Although gastric cancer (GC) is one of the most common cancers with high incidence and mortality rates, its pathogenesis is still not elucidated. GC carcinogenesis is complicated and involved in the activation of oncoproteins and inactivation of tumor suppressors. The ubiquitin-proteasome system (UPS) is crucial for protein degradation and regulation of physiological and pathological processes. E3 ubiquitin ligases are pivotal enzymes in UPS, containing various subfamily proteins. Previous studies report that some E3 ligases, including SKP2, CUL1, and MDM2, act as oncoproteins in GC carcinogenesis. On the other hand, FBXW7, FBXL5, FBXO31, RNF43, and RNF180 exert as tumor suppressors in GC carcinogenesis. Moreover, E3 ligases modulate cell growth, cell apoptosis, and cell cycle; thus, it is complicated to confer cisplatin resistance/sensitivity in GC cells. The intrinsic and acquired cisplatin resistance limits its clinical application against GC. In this review, we explore oncogenic and tumor suppressive roles of E3 ligases in GC carcinogenesis and focus on the effects of E3 ligases on cisplatin resistance in GC cells, which will provide novel therapeutic targets for GC therapy, especially for cisplatin-resistant patients.

Tripartite motif‑containing 14 regulates cell proliferation and apoptosis in cervical cancer via the Akt signaling pathway

Tripartite motif‑containing (TRIM) 14 is a protein of the TRIM family. Studies have indicated that TRIM14 may be used as an oncogene in tumor cells, such as osteosarcoma, non‑small cell lung cancer and breast cancer through different pathways. However, the functions of TRIM14 in cervical cancer cells remain unclear. Therefore, this study aimed to investigate the functions of TRIM14 in cervical cancer cells and its underlying mechanism. Caski cells stably expressing TRIM14 and SiHa, and HeLa cells stably expressing TRIM14 short hairpin RNA were constructed by lentivirus‑mediated overexpression or knockdown systems. The effects of TRIM14 on proliferation and apoptosis of cervical cancer cells were detected by Cell Counting Kit‑8 (CCK‑8) assay and flow cytometry, respectively. In addition, reverse transcription‑quantitative (RT‑q) PCR and western blotting were used to investigate the expression levels of TRIM14 and of signaling pathway marker protein including P21, caspase‑3, cleaved caspase‑3, Akt and phosphorylated Akt. The results of RT‑qPCR and western blotting revealed that TRIM14 was highly expressed in human cervical cancer tissues and cell lines compared with adjacent normal tissues and normal cervical epithelial cells. TRIM14 also regulated cell proliferation and apoptosis of human SiHa, HeLa and Caski cervical cancer cell lines through the Akt signaling pathway. Additionally, TRIM14 protein levels were related to the clinical and pathological features of cervical cancer. CCK‑8 assay and flow cytometry demonstrated that TRIM14 expression could promote cervical cancer cell proliferation and autophagy suppression. Taken together, TRIM14‑induced cell proliferation and apoptosis inhibition may by evoked by the activation of the Akt pathway. This study demonstrated the role of TRIM14 in cervical cancer, and reveals its mechanism of action as a potential therapeutic target for cervical cancer.

Multifaceted Roles of TRIM Proteins in Colorectal Carcinoma

Colorectal cancer (CRC) is one of the most frequently diagnosed tumor in humans and one of the most common causes of cancer-related death worldwide. The pathogenesis of CRC follows a multistage process which together with somatic gene mutations is mainly attributed to the dysregulation of signaling pathways critically involved in the maintenance of homeostasis of epithelial integrity in the intestine. A growing number of studies has highlighted the critical impact of members of the tripartite motif (TRIM) protein family on most types of human malignancies including CRC. In accordance, abundant expression of many TRIM proteins has been observed in CRC tissues and is frequently correlating with poor survival of patients. Notably, some TRIM members can act as tumor suppressors depending on the context and the type of cancer which has been assessed. Mechanistically, most cancer-related TRIMs have a critical impact on cell cycle control, apoptosis, epithelial–mesenchymal transition (EMT), metastasis, and inflammation mainly through directly interfering with diverse oncogenic signaling pathways. In addition, some recent publications have emphasized the emerging role of some TRIM members to act as transcription factors and RNA-stabilizing factors thus adding a further level of complexity to the pleiotropic biological activities of TRIM proteins. The current review focuses on oncogenic signaling processes targeted by different TRIMs and their particular role in the development of CRC. A better understanding of the crosstalk of TRIMs with these signaling pathways relevant for CRC development is an important prerequisite for the validation of TRIM proteins as novel biomarkers and as potential targets of future therapies for CRC.

TRIM14 promotes endothelial activation via activating NF-κB signaling pathway

Endothelial activation by proinflammatory cytokines is closely associated to the pathogenesis of atherosclerosis and other vascular diseases; however, the molecular mechanisms controlling endothelial activation are not fully understood. Here we identify TRIM14 as a new positive regulator of endothelial activation via activating NF-κB signal pathway. TRIM14 is highly expressed in human vascular endothelial cells (ECs) and markedly induced by inflammatory stimuli such as TNF-α, IL-1β, and LPS. Overexpression of TRIM14 significantly increased the expression of adhesion molecules such as VCAM-1, ICAM-1, E-selectin, and cytokines such as CCL2, IL-8, CXCL-1, and TNF-α in activated ECs and by which it facilitated monocyte adhesion to ECs. Conversely, knockdown of TRIM14 has opposite effect on endothelial activation. Upon TNF-α stimulation, TRIM14 is recruited to IKK complex via directly binding to NEMO and promotes the phosphorylation of IκBα and p65, which is dependent on its K63-linked ubiquitination. Meanwhile, p65 can directly bind to the promoter regions of human TRIM14 gene and control its mRNA transcription. Finally, TRIM14 protein level is significantly upregulated in mouse and human atheroma compared to normal arteries. Taken together, these results indicate that TRIM14-NF-κB forms a positive feedback loop to enhance EC activation and TRIM14 may be a potential therapeutic target for vascular inflammatory diseases such as atherosclerosis.

The Tripartite Nexus: Autophagy, Cancer, and Tripartite Motif-Containing Protein Family Members

Autophagy is a cellular degradative process that has multiple important actions in cancer. Autophagy modulation is under consideration as a promising new approach to cancer therapy. However, complete autophagy dysregulation is likely to have substantial undesirable side effects. Thus, more targeted approaches to autophagy modulation may prove clinically beneficial. One potential avenue to achieving this goal is to focus on the actions of tripartite motif-containing protein family members (TRIMs). TRIMs have key roles in an array of cellular processes, and their dysregulation has been extensively linked to cancer risk and prognosis. As detailed here, emerging data shows that TRIMs can play important yet context-dependent roles in controlling autophagy and in the selective targeting of autophagic substrates. This review covers how the autophagy-related actions of TRIM proteins contribute to cancer and the possibility of targeting TRIM-directed autophagy in cancer therapy.

The role of TRIM family proteins in the regulation of cancer stem cell self-renewal

The tripartite-motif (TRIM) family of proteins represents one of the largest classes of putative single protein RING-finger E3 ubiquitin ligases. The members of this family are characterized by an N-terminal TRIM motif containing one RING-finger domain, one or two zinc-finger domains called B boxes (B1 box and B2 box), and a coiled-coil region. The TRIM motif can be found in isolation or in combination with a variety of C-terminal domains, and based on C-terminus, TRIM proteins are classified into 11 distinct groups. Because of the complex nature of TRIM proteins, they are implicated in a variety of cellular functions and biological processes, including regulation of cell proliferation, cell division and developmental processes, cancer transformation, regulation of cell metabolism, autophagocytosis, modification of chromatin status, regulation of gene transcription, post-translational modifications, and interactions with pathogens. Here, we demonstrate the specific activities of TRIM family proteins that contribute to the cancer stem cell phenotype. A growing body of evidence demonstrates that several TRIM members guarantee the acquisition of stem cell properties and the ability to sustain stem-like phenotype by cancer cells using distinct mechanisms. For other members, further work is needed to understand their full contribution to stem cell self-renewal. Identification of TRIM proteins that possess the potential to serve as therapeutic targets may result in the development of new therapeutic strategies. Finally, these strategies may result in the disruption of the machinery of stemness acquisition, which may prevent tumor growth, progression, and overcome the resistance to anticancer therapies.

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.

Tripartite motif-containing 14 (TRIM14) promotes epithelial-mesenchymal transition via ZEB2 in glioblastoma cells

BACKGROUND

Several members of the tripartite motif-containing (TRIM) protein family have been reported to serve as vital regulators of tumorigenesis. Recent studies have demonstrated an oncogenic role of TRIM 14 in multiple human cancers; however, the importance of this protein in glioblastoma remains to be elucidated.

METHODS

The expression levels of TRIM14 were analyzed in a series of database and were examined in a variety of glioblastoma cell lines. Two independent TRIM14 shRNA were transfected into LN229 and U251 cells, and the effect of TRIM14 depletion was confirmed. Transwell assay and wound healing assay assay were carried out to assess the effect of TRIM14 depletion on glioblastoma cell invasion and migration. Western blotting was performed to screen the downstream gene of TRIM14. The stability analysis and Ubiquitylation assays and Orthotopic xenograft studies were also performed to investigate the role of TRIM14 and the relationship with downstream gene. Human glioblastoma tissues were obtained and immunohistochemical staining were carried out to confirm the clinical significance of TRIM14.

RESULTS

In this study, we showed that TRIM14 was upregulated in human glioblastoma specimens and cell lines, and correlated with glioblastoma progression and shorter patient survival times. Functional experiments showed that decreased TRIM14 expression reduced glioblastoma cell invasion and migration. Furthermore, we identified that zinc finger E-box binding homeobox 2 (ZEB2), a transcription factor involved in epithelial-mesenchymal transition, is a downstream target of TRIM14. Further investigation revealed that TRIM14 inactivation significantly facilitated ZEB2 ubiquitination and proteasomal degradation, which led to aggressive invasion and migration. Our findings provide insight into the specific biological role of TRIM14 in tumor invasion.

CONCLUSIONS

Our findings provide insight into the specific biological role of TRIM14 in tumor invasion, and suggest that targeting the TRIM14/ZEB2 axis might be a novel therapeutic approach for blocking glioblastoma.