TRIM29 prevents hepatocellular carcinoma progression by inhibiting Wnt/β-catenin signaling pathway

Targeting Hepatic Cancer Stem Cells (CSCs) and Related Drug Resistance by Small Interfering RNA (siRNA)

Tumor recurrence after curative therapy and hepatocellular carcinoma (HCC) cells' resistance to conventional therapies is the reasons for the worse clinical results of HCC patients. A tiny population of cancer cells with a strong potential for self-renewal, differentiation, and tumorigenesis has been identified as cancer stem cells (CSCs). The discovery of CSC surface markers and the separation of CSC subpopulations from HCC cells have been made possible by recent developments in the study of hepatic (liver) CSCs. Hepatic CSC surface markers include epithelial cell adhesion molecules (EpCAM), CD133, CD90, CD13, CD44, OV-6, ALDH, and K19. CSCs have a significant influence on the development of cancer, invasiveness, self-renewal, metastasis, and drug resistance in HCC, and thus provide a therapeutic chance to treat HCC and avoid its recurrence. Therefore, it is essential to develop treatment approaches that specifically and effectively target hepatic stem cells. Given this, one potential treatment approach is to use particular small interfering RNA (siRNA) to target CSC, disrupting their behavior and microenvironment as well as changing their epigenetic state. The characteristics of CSCs in HCC are outlined in this study, along with new treatment approaches based on siRNA that may be used to target hepatic CSCs and overcome HCC resistance to traditional therapies.

Wnt/β-Catenin signaling pathway in hepatocellular carcinoma: pathogenic role and therapeutic target

Hepatocellular carcinoma (HCC) is the most common primary malignant liver tumor and one of the leading causes of cancer-related deaths worldwide. The Wnt/β-Catenin signaling pathway is a highly conserved pathway involved in several biological processes, including the improper regulation that leads to the tumorigenesis and progression of cancer. New studies have found that abnormal activation of the Wnt/β-Catenin signaling pathway is a major cause of HCC tumorigenesis, progression, and resistance to therapy. New perspectives and approaches to treating HCC will arise from understanding this pathway. This article offers a thorough analysis of the Wnt/β-Catenin signaling pathway's function and its therapeutic implications in HCC.

TRIM29 modulates proteins involved in PTEN/AKT/mTOR and JAK2/STAT3 signaling pathway and suppresses the progression of hepatocellular carcinoma

Tripartite motif-containing 29 (TRIM29), also known as the ataxia telangiectasia group D-complementing (ATDC) gene, has been reported to play an oncogenic or tumor suppressive role in developing different tumors. So far, its expression and biological functions in hepatocellular carcinoma (HCC) remain unclear. We investigated TRIM29 expression pattern in human HCC samples using quantitative RT-PCR and immunohistochemistry. Relationships between TRIM29 expression level, clinical prognostic indicators, overall survival (OS), and disease-free survival (DFS) were evaluated by Kaplan-Meier analysis and Cox proportional hazards model. A series of in vitro experiments and a xenograft tumor model were conducted to detect the functions of TRIM29 in HCC cells. RNA sequencing, western blotting, and immunochemical staining were performed to assess the molecular regulation of TRIM29 in HCC. We found that the mRNA and protein levels of TRIM29 were significantly reduced in HCC samples, compared with adjacent noncancerous tissues, and were negatively correlated with poor differentiation of HCC tissues. Survival analysis confirmed that lower TRIM29 expression significantly correlated with shorter OS and DFS of HCC patients. TRIM29 overexpression remarkably inhibited cell proliferation, migration, and EMT in HCC cells, whereas knockdown of TRIM29 reversed these effects. Moreover, deactivation of the PTEN/AKT/mTOR and JAK2/STAT3 pathways might be involved in the tumor suppressive role of TRIM29 in HCC. Our findings indicate that TRIM29 in HCC exerts its tumor suppressive effects through inhibition of the PTEN/AKT/mTOR and JAK2/STAT3 signaling pathways and may be used as a potential biomarker for survival in patients with HCC.

Deciphering roles of TRIMs as promising targets in hepatocellular carcinoma: current advances and future directions

Tripartite motif (TRIM) family is assigned to RING-finger-containing ligases harboring the largest number of proteins in E3 ubiquitin ligating enzymes. E3 ubiquitin ligases target the specific substrate for proteasomal degradation via the ubiquitin-proteasome system (UPS), which seems to be a more effective and direct strategy for tumor therapy. Recent advances have demonstrated that TRIM genes associate with the occurrence and progression of hepatocellular carcinoma (HCC). TRIMs trigger or inhibit multiple biological activities like proliferation, apoptosis, metastasis, ferroptosis and autophagy in HCC dependent on its highly conserved yet diverse structures. Remarkably, autophagy is another proteolytic pathway for intracellular protein degradation and TRIM proteins may help to delineate the interaction between the two proteolytic systems. In depth research on the precise molecular mechanisms of TRIM family will allow for targeting TRIM in HCC treatment. We also highlight several potential directions warranted further development associated with TRIM family to provide bright insight into its translational values in hepatocellular carcinoma.

The role of TRIM family in metabolic associated fatty liver disease

Metabolic associated fatty liver disease (MAFLD) ranks among the most prevalent chronic liver conditions globally. At present, the mechanism of MAFLD has not been fully elucidated. Tripartite motif (TRIM) protein is a kind of protein with E3 ubiquitin ligase activity, which participates in highly diversified cell activities and processes. It not only plays an important role in innate immunity, but also participates in liver steatosis, insulin resistance and other processes. In this review, we focused on the role of TRIM family in metabolic associated fatty liver disease. We also introduced the structure and functions of TRIM proteins. We summarized the TRIM family's regulation involved in the occurrence and development of metabolic associated fatty liver disease, as well as insulin resistance. We deeply discussed the potential of TRIM proteins as targets for the treatment of metabolic associated fatty liver disease.

HMMR alleviates endoplasmic reticulum stress by promoting autophagolysosomal activity during endoplasmic reticulum stress-driven hepatocellular carcinoma progression

BACKGROUND

The mechanism of hepatitis B virus (HBV)-induced carcinogenesis remains an area of interest. The accumulation of hepatitis B surface antigen in the endoplasmic reticulum (ER) of hepatocytes stimulates persistent ER stress. Activity of the unfolded protein response (UPR) pathway of ER stress may play an important role in inflammatory cancer transformation. How the protective UPR pathway is hijacked by cells as a tool for malignant transformation in HBV-related hepatocellular carcinoma (HCC) is still unclear. Here, we aimed to define the key molecule hyaluronan-mediated motility receptor (HMMR) in this process and explore its role under ER stress in HCC development.

METHODS

An HBV-transgenic mouse model was used to characterize the pathological changes during the tumor progression. Proteomics and transcriptomics analyses were performed to identify the potential key molecule, screen the E3 ligase, and define the activation pathway. Quantitative real-time PCR and Western blotting were conducted to detect the expression of genes in tissues and cell lines. Luciferase reporter assay, chromatin immunoprecipitation, coimmunoprecipitation, immunoprecipitation, and immunofluorescence were employed to investigate the molecular mechanisms of HMMR under ER stress. Immunohistochemistry was used to clarify the expression patterns of HMMR and related molecules in human tissues.

RESULTS

We found sustained activation of ER stress in the HBV-transgenic mouse model of hepatitis-fibrosis-HCC. HMMR was transcribed by c/EBP homologous protein (CHOP) and degraded by tripartite motif containing 29 (TRIM29) after ubiquitination under ER stress, which caused the inconsistent expression of mRNA and protein. Dynamic expression of TRIM29 in the HCC progression regulated the dynamic expression of HMMR. HMMR could alleviate ER stress by increasing autophagic lysosome activity. The negative correlation between HMMR and ER stress, positive correlation between HMMR and autophagy, and negative correlation between ER stress and autophagy were verified in human tissues.

CONCLUSIONS

This study identified the complicated role of HMMR in autophagy and ER stress, that HMMR controls the intensity of ER stress by regulating autophagy in HCC progression, which could be a novel explanation for HBV-related carcinogenesis.

TRIM55 Promotes Proliferation of Hepatocellular Carcinoma Through Stabilizing TRIP6 to Activate Wnt/β-Catenin Signaling

PURPOSE

Tripartite motif containing 55 (TRIM55) is a 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, its proliferative function in hepatocellular carcinoma (HCC) has been poorly studied, and its underlying molecular mechanism remains unclear. In the present study, we investigated the role of TRIM55 in HCC and its mechanism of promoting HCC proliferation.

MATERIALS AND METHODS

Protein expression levels of TRIM55 were measured in paired HCC and normal tissue samples using immunohistochemical (IHC) staining. The correlation between TRIM55 and clinical features was evaluated by statistical analysis. At the same time, overexpression and knockdown experiments, cycloheximide (CHX) interference experiments, ubiquitination, co-immunoprecipitation and immunofluorescence staining experiments, as well as animal experiments were used to evaluate the potential mechanism that TRIM55 promotes proliferation of hepatocellular carcinoma in vitro and in vivo.

RESULTS

TRIM55 expression in HCC specimens was higher compared with the corresponding non-tumor tissues. The overall survival and disease-free survival time of patients with high TRIM55 expression were shorter than those with low expression of TRIM55. Functionally, TRIM55 promoted the proliferation of HCC cells and accelerated the growth of HCC xenografts. Mechanistically, TRIM55 interacted with thyroid receptor interacting protein 6 (TRIP6) and regulate its stability by influencing the ubiquitination process, thereby affecting the Wnt signaling pathway.

CONCLUSION

Our results indicate that TRIM55 promotes HCC proliferation by activating Wnt signaling pathways by stabilizing TRIP6. Therefore, targeting TRIM55 may be an effective therapeutic strategy to inhibit HCC growth.

LncRNA ELFN1-AS1 upregulates TRIM29 by suppressing miR-211-3p to promote gastric cancer progression

Long noncoding RNA (lncRNA) extracellular leucine rich repeat and fibronectin type III domain containing 1-antisense RNA 1 (ELFN1-AS1) has been found to be upregulated in various tumors. However, the biological functions of ELFN1-AS1 in gastric cancer (GC) are not entirely understood. In the present study, the expression levels of ELFN1-AS1, miR-211-3p, and TRIM29 are determined using reverse transcription-quantitative PCR. Subsequently, CCK8, EdU, and colony formation assays are performed to determine GC cell vitality. The migratory and invasive capabilities of GC cells are further evaluated using transwell invasion and cell scratch assays. Western blot analysis is performed to quantify the levels of proteins associated with GC cell apoptosis and epithelialmesenchymal transition (EMT). The competing endogenous RNA (ceRNA) activity of ELFN1-AS1 on TRIM29 through miR-211-3p is confirmed by pull-down, RIP, and luciferase reporter assays. Our study proves that ELFN1-AS1 and TRIM29 are highly expressed in GC tissues. ELFN1-AS1 silencing inhibits GC cell proliferation, migration, invasion and EMT, and induces cell apoptosis. Rescue experiments reveal that the oncogenicity of ELFN1-AS1 is modulated by acting as a sponge for miR-211-3p, thereby increasing the expression of the target gene of miR-211-3p, TRIM29. In summary, ELFN1-AS1 maintains GC cell tumorigenicity via the ELFN1-AS1/miR-211-3p/TRIM29 axis, indicating that this axis can be directed for GC treatment in the future.

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.

TRIM proteins in hepatocellular carcinoma

The tripartite motif (TRIM) protein family is a highly conserved group of E3 ligases with 77 members known in the human, most of which consist of a RING-finger domain, one or two B-box domains, and a coiled-coil domain. Generally, TRIM proteins function as E3 ligases to facilitate specific proteasomal degradation of target proteins. In addition, E3 ligase independent functions of TRIM protein were also reported. In hepatocellular carcinoma, expressions of TRIM proteins are both regulated by genetic and epigenetic mechanisms. TRIM proteins regulate multiple biological activities and signaling cascades. And TRIM proteins influence hallmarks of HCC. This review systematically demonstrates the versatile roles of TRIM proteins in HCC and helps us better understand the molecular mechanism of the development and progression of HCC.

A hybrid feature selection algorithm and its application in bioinformatics

Feature selection is an independent technology for high-dimensional datasets that has been widely applied in a variety of fields. With the vast expansion of information, such as bioinformatics data, there has been an urgent need to investigate more effective and accurate methods involving feature selection in recent decades. Here, we proposed the hybrid MMPSO method, by combining the feature ranking method and the heuristic search method, to obtain an optimal subset that can be used for higher classification accuracy. In this study, ten datasets obtained from the UCI Machine Learning Repository were analyzed to demonstrate the superiority of our method. The MMPSO algorithm outperformed other algorithms in terms of classification accuracy while utilizing the same number of features. Then we applied the method to a biological dataset containing gene expression information about liver hepatocellular carcinoma (LIHC) samples obtained from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx). On the basis of the MMPSO algorithm, we identified a 18-gene signature that performed well in distinguishing normal samples from tumours. Nine of the 18 differentially expressed genes were significantly up-regulated in LIHC tumour samples, and the area under curves (AUC) of the combination seven genes (ADRA2B, ERAP2, NPC1L1, PLVAP, POMC, PYROXD2, TRIM29) in classifying tumours with normal samples was greater than 0.99. Six genes (ADRA2B, PYROXD2, CACHD1, FKBP1B, PRKD1 and RPL7AP6) were significantly correlated with survival time. The MMPSO algorithm can be used to effectively extract features from a high-dimensional dataset, which will provide new clues for identifying biomarkers or therapeutic targets from biological data and more perspectives in tumor research.

TRIM29 in Cutaneous Squamous Cell Carcinoma

Tripartite motif (TRIM) proteins play important roles in a wide range of cell physiological processes, such as signal transduction, transcriptional regulation, innate immunity, and programmed cell death. TRIM29 protein, encoded by the ATDC gene, belongs to the RING-less group of TRIM protein family members. It consists of four zinc finger motifs in a B-box domain and a coiled-coil domain, and makes use of the B-box domain as E3 ubiquitin ligase in place of the RING. TRIM29 was found to be involved in the formation of homodimers and heterodimers in relation to DNA binding; additional studies have also demonstrated its role in carcinogenesis, DNA damage signaling, and the suppression of radiosensitivity. Recently, we reported that TRIM29 interacts with keratins and FAM83H to regulate keratin distribution. Further, in cutaneous SCC, the expression of TRIM29 is silenced by DNA methylation, leading to the loss of TRIM29 and promotion of keratinocyte migration. This paper reviews the role of TRIM family proteins in malignant tumors, especially the role of TRIM29 in cutaneous SCC.

Identification of Signature Genes in the PD-1 Relative Gastric Cancer Using a Combined Analysis of Gene Expression and Methylation Data

BACKGROUND

The morbidity and mortality rates for gastric cancer (GC) rank second among all cancers, indicating the serious threat it poses to human health, as well as human life. This study aims to identify the pathways and genes as well as investigate the molecular mechanisms of tumor-related genes in gastric cancer (GC).

METHOD

We compared differentially expressed genes (DEGs) and differentially methylated genes (DMGs) in gastric cancer and normal tissue samples using The Cancer Genome Atlas (TCGA) data. The Kyoto Encyclopedia of Gene and Genome (KEGG) and the Gene Ontology (GO) enrichment analysis' pathway annotations were conducted on DMGs and DEGs using a clusterProfiler R package to identify the important functions, as well as the biological processes and pathways involved. The intersection of the two was chosen and defined as differentially methylated and expressed genes (DMEGs). For DMEGs, we used the principal component analysis (PCA) to differentiate gastric cancer from adjacent samples. The linear discriminant analysis method was applied to categorize the samples using DMEGs methylation data and DMEGs expression profiles data and was validated using the leave-one-out cross-validation (LOOCV) method. We plotted the ROC curve for the classification and calculated the AUC (area under the ROC curve) value for a more intuitive view of the classification effect. We also used the NetworkAnalyst 3.0 tool to analyze DMEGs, using DrugBank to acquire information on protein-drug interactions and generate a network map of gene-drug interactions.

RESULTS

We identified a total of 971 DMGs in 188 PD-1 negative and 187 PD-1 positive gastric cancer samples obtained from TCGA. The KEGG and GO enrichment analysis showed the involvement of the regulation of ion transmembrane transport, collagen-containing extracellular matrix, cell-cell junction, and peptidase regulator activity. We simultaneously obtained 1,189 DEGs, out of which 986 were downregulated, while 203 were upregulated in tumors. The enriched analysis of the GO's and KEGG's pathways indicated that the most significant pathways included an intestinal immune network for IgA production, Staphylococcus aureus infection, cytokine-cytokine receptor interaction, and viral protein interaction with cytokine and cytokine receptor, which have previously been linked with gastric cancer. The compound DB01830 can bind well to the active site of the LCK protein and shows good stability, thus making it a potential inhibitor of the LCK protein. To observe the relationship between DMEGs' expression and prognosis, we observed 10 genes, among which were TRIM29, TSPAN8, EOMES, PPP1R16B, SELL, PCED1B, IYD, JPH1, CEACAM5, and RP11-44K6.2. Their high expressions were related to high risks. Besides, those genes were validated in different internal and external validation sets.

CONCLUSION

These results may provide potential molecular biological therapy for PD-1 negative gastric cancer.

miR-34c-5p mediates the cellular malignant behaviors of oral squamous cell carcinoma through targeted binding of TRIM29

Background

This investigation examined the effects of the microRNA miR-34c-5p on the proliferation, migration, and invasion of oral squamous cell carcinoma (OSCC) and the mechanisms involved.

Methods

The Gene Expression Omnibus (GEO) database was used to filter the chips, and the GEO2R software (https://www.ncbi.nlm.nih.gov/geo/geo2r/) was used to analyze the microarray data (GSE28100 and GSE45238). Gene set enrichment analysis (GSEA) was used to study the relationship between the expression of miR-34c-5p and the distant metastasis and pathological grade of OSCC. The correlation between TRIM29 (tripartite motif containing 29) expression and the malignant clinical phenotype of OSCC was also examined. The mRNA and protein expression levels of miR-34c-5p and TRIM29 were measured by real time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot analysis. The proliferation, migration, invasion and apoptosis of the human oral squamous carcinoma cell lines CAL-27 and Tca8113 was assessed by performing cell-counting kit-8 (CCK-8) assays, colony formation assays, transwell tests, wound scratch tests and flow cytometry. Luciferase reporter assays were used to predict the relationship between miR-34c-5p and TRIM29. A xenograft nude model was established and used to evaluate the effect of miR-34c-5p on tumor growth in female BALB/c mice.

Results

The expression of miR-34c-5p was significantly correlated with the proliferation, migration, and metastasis of OSCC. Overexpression of miR-34c-5p promoted the proliferation, migration, and invasion of CAL-27 and Tca8113 cells, and suppressed their apoptosis. Inversely, low expression of miR-34c-5p suppressed the proliferation, migration, and invasion of CAL-27 and Tca8113 cells, and promoted their apoptosis. Overexpression of miR-34c-5p promoted tumor growth in the xenograft nude mice model. The expression of TRIM29 was related to malignant clinical phenotype of OSCC. Overexpression of TRIM29 inhibited the proliferation, migration and invasion of CAL-27 and Tca8113 cell, and induced their apoptosis. TRIM29 knockout had just the opposite effect. Importantly, miR-34c-5p binds to TRIM29 and inhibited TRIM29 expression.

Conclusions

MiR-34c-5p regulates the proliferation, migration, invasion, and apoptosis of OSCC through targeted binding of TRIM29. This may represent a novel therapeutic target for the treatment of patients with OSCC.

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.

ARID1B/SUB1-activated lncRNA HOXA-AS2 drives the malignant behaviour of hepatoblastoma through regulation of HOXA3

It has been becoming increasingly evident that long non‐coding RNAs (lncRNAs) play important roles in various human cancers. However, the biological processes and clinical significance of most lncRNAs in hepatoblastoma (HB) remain unclear. In our previous study, genome‐wide analysis with a lncRNA microarray found that lncRNA HOXA‐AS2 was up‐regulated in HB. Stable transfected cell lines with HOXA‐AS2 knockdown or overexpression were constructed in HepG2 and Huh6 cells, respectively. Our data revealed knockdown of HOXA‐AS2 increased cell apoptosis and inhibited cell proliferation, migration and invasion in HB. Up‐regulation of HOXA‐AS2 promoted HB malignant biological behaviours. Mechanistic investigations indicated that HOXA‐AS2 was modulated by chromatin remodelling factor ARID1B and transcription co‐activator SUB1, thereby protecting HOXA3 from degradation. Therefore, HOXA‐AS2 positively regulates HOXA3, which might partly demonstrate the involvement of HOXA3 in HOXA‐AS2‐mediated HB carcinogenesis. In conclusion, HOXA‐AS2 is significantly overexpressed in HB and the ARID1B/HOXA‐AS2/HOXA3 axis plays a critical role in HB tumorigenesis and development. These results might provide a potential new target for HB diagnosis and therapy.

Identification of key genes and pathways for melanoma in the TRIM family

Certain members of the TRIM family have been shown to have abnormal expression and prognostic value in cancer. However, in the development and progression of melanoma, the role of different TRIM family members remains unknown. To address this issue, this study used the Oncomine, UCSC, Human Protein Atlas, DAVID, and GEPIA databases to study the role of TRIMs in the prognosis of melanoma. Differential expression of TRIM2, TRIM7, TRIM8, TRIM18 (MID1), TRIM19 (PML), TRIM27, and TRIM29 may play an important role in the development of melanoma. The expression TRIM7 and TRIM29 appeared to be helpful in the identification of primary tumors and metastases. Survival analysis suggested that the expression of TRIM27 significantly affected the overall survival and disease‐free survival of melanoma, and its expression was confirmed by qRT‐PCR. Our results indicated that the expression level of TRIM27 might be a prognostic marker of melanoma.

m6A-YTHDF1-mediated TRIM29 upregulation facilitates the stem cell-like phenotype of cisplatin-resistant ovarian cancer cells

Ovarian cancer is the deadliest gynaecologic malignancy, and the five-year survival rate of patients is less than 35% worldwide. Cancer stem cells (CSCs) are a population of cells with stem-like characteristics that are thought to cause chemoresistance and recurrence. TRIM29 is aberrantly expressed in various cancers and associated with cancer development and progression. Previous studies showed that the upregulation of TRIM29 expression in pancreatic cancer is related to stem-like characteristics. However, the role of TRIM29 in ovarian cancer is poorly understood. In this study, we found that TRIM29 expression was increased at the translational level in both the cisplatin-resistant ovarian cancer cells and clinical tissues. Increased TRIM29 expression was associated with a poor prognosis of patients with ovarian cancer. In addition, TRIM29 could enhance the CSC-like characteristics of the cisplatin-resistant ovarian cancer cells. Recruitment of YTHDF1 to m6A-modified TRIM29 was involved in promoting TRIM29 translation in the cisplatin-resistant ovarian cancer cells. Knockdown of YTHDF1 suppressed the CSC-like characteristics of the cisplatin-resistant ovarian cancer cells, which could be rescued by ectopic expression of TRIM29. This study suggests TRIM29 may act as an oncogene to promote the CSC-like features of cisplatin-resistant ovarian cancer in an m6A-YTHDF1-dependent manner. Due to the roles of TRIM29 and YTHDF1 in the promotion of CSC-like features, they may become potential therapeutic targets to combat the recurrence of ovarian cancer.

TRIM29 inhibits miR-873-5P biogenesis via CYTOR to upregulate fibronectin 1 and promotes invasion of papillary thyroid cancer cells

Papillary thyroid cancer (PTC) is the most common endocrine tumor with an increasing incidence, has a strong propensity for neck lymph node metastasis. Limited treatment options are available for patients with advanced or recurrent metastatic disease, resulting in a poor prognosis. Tripartite motif protein 29 (TRIM29) is dysregulated in various cancer and functions as oncogene or tumor suppressor in discrete cancers. In this study, we found that both TRIM29 and fibronectin 1 (FN1) were upregulated with positive correlation in PTC tissues. Neither overexpression nor downregulation of TRIM29 altered the proliferation of PTC cells significantly. Overexpression of TRIM29 significantly promotes, while knockdown of TRIM29 significantly decreases migration and invasion by regulating FN1 expression in PTC cells. In terms of mechanism, we found that TRIM29 altered the stability of FN1 mRNA via regulation of miR-873-5p expression. The current study also demonstrated that long non-coding RNA (LncRNA) CYTOR suppressed maturation of miR-873-5p via interaction with premiR-873, and TRIM29 decreased miR-873-5p via upregulation of CYTOR. This study suggests that involvement of TRIM29 in migration and invasion in PTC cells may reveal potential metastatic mechanism of PTC and represent a novel therapeutic target and strategy.

Long non‑coding RNA TP73‑AS1 accelerates the progression and cisplatin resistance of non‑small cell lung cancer by upregulating the expression of TRIM29 via competitively targeting microRNA‑34a‑5p

Non-small cell lung cancer (NSCLC) is a leading subtype of lung cancer, with high mortality rates. Recently, long non-coding RNAs (lncRNAs) have been associated with NSCLC. The present study aimed to examine the role of the TP73 antisense RNA 1 (TP73-AS1) lncRNA in NSCLC. TP73-AS1 and microRNA(miR)-34a-5p expression levels were measured using reverse transcription-quantitative PCR (RT-qPCR) and chromogenic in situ hybridization (CISH). Cell proliferation, apoptosis, migration and invasion was determined using Cell Counting Kit-8 (CCK-8), flow cytometry, Transwell and Matrigel assays, respectively. The median inhibitory concentration (IC₅₀) value of cisplatin (cis-diamminedichloroplatinum; DDP) was assessed using a CCK-8 assay. The interaction between miR-34a-5p and TP73-AS1 or tripartite motif-containing 29 (TRIM29) was predicted using microRNA.org and Starbase, then verified using a dual-luciferase reporter assay. The expression of TRIM29 was quantified at the mRNA and protein level using RT-qPCR and western blot analysis, respectively. TP73-AS1 was significantly upregulated, while miR-34a-5p was downregulated in NSCLC tissues and cells. Functionally, TP73-AS1 knockdown inhibited proliferation, migration, invasion and DDP resistance, whilst inducing apoptosis in NSCLC cells. miR-34a-5p was identified as a target for TP73-AS1, and its inhibition reversed the effects of TP73-AS1 knockdown on NSCLC cells. In addition, TRIM29 was targeted by miR-34a-5p, and its overexpression reversed the effects of miR-34a-5p. Moreover, TP73-AS1 acted as a molecular sponge for miR-34a-5p, increasing the expression of TRIM29. In conclusion, TP73-AS1 contributed to proliferation, migration and DDP resistance but inhibited apoptosis of NSCLC cells by upregulating TRIM29 and sponging miR-34a-5p.

Tumor suppressor p53 cross-talks with TRIM family proteins

p53 is a key tumor suppressor. As a transcription factor, p53 accumulates in cells in response to various stress signals and selectively transcribes its target genes to regulate a wide variety of cellular stress responses to exert its function in tumor suppression. In addition to tumor suppression, p53 is also involved in many other physiological and pathological processes, e.g. anti-infection, immune response, development, reproduction, neurodegeneration and aging. To maintain its proper function, p53 is under tight and delicate regulation through different mechanisms, particularly the posttranslational modifications. The tripartite motif (TRIM) family proteins are a large group of proteins characterized by the RING, B-Box and coiled-coil (RBCC) domains at the N-terminus. TRIM proteins play important roles in regulation of many fundamental biological processes, including cell proliferation and death, DNA repair, transcription, and immune response. Alterations of TRIM proteins have been linked to many diseases including cancer, infectious diseases, developmental disorders, and neurodegeneration. Interestingly, recent studies have revealed that many TRIM proteins are involved in the regulation of p53, and at the same time, many TRIM proteins are also regulated by p53. Here, we review the cross-talk between p53 and TRIM proteins, and its impact upon cellular biological processes as well as cancer and other diseases.

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.

MicroRNA-621 inhibits cell proliferation and metastasis in bladder cancer by suppressing Wnt/β-catenin signaling

Increasing evidence has shown that dysregulation of microRNA-621 (miR-621) is demonstrated to be associated with several cancers. However, the role of miR-621 in bladder cancer (BCa) remains unclear. Herein, we aimed to study the expression pattern, biological function, and molecular mechanism of miR-621 in BCa. First, we demonstrated that miR-621 was frequently downregulated in BCa tissues and cell lines compared with the adjacent normal BCa tissues and non-cancerous immortalized urothelial cell line. In addition, the expression of miR-621 was negatively correlated with overall survival of BCa patients. Functional experiments suggessted that miR-621 inhibited the proliferation and metastasis of BCa cells. Notably, dual-luciferase assay showed that miR-621 directly targeted the 3' UTR of TRIM29, which was frequently upregulated in BCa tissues and displayed inverse correlation with miR-621 expression. Furthermore, we demonstrated that miR-621 inhibited the proliferation and metastasis of BCa cells via Wnt/β-catenin signaling pathway by targeting TRIM29. Our study suggested that the miR-621/TRIM29 axis inhibits the proliferation and metastasis of BCa cells via Wnt/β-catenin signaling pathway and may have potential applications for development of BCa diagnosis or treatment.