Silencing of tripartite motif (TRIM) 29 inhibits proliferation and invasion and increases chemosensitivity to cisplatin in human lung squamous cancer NCI-H520 cells

Tripartite motif family - its role in tumor progression and therapy resistance: a review

PURPOSE OF REVIEW

In this review, we summarized published articles on the role of tripartite motif (TRIM) family members in the initiation and development of human malignancies.

RECENT FINDINGS

The ubiquitin-proteasome system (UP-S) plays a critical role in cellular activities, and UP-S dysregulation contributes to tumorigenesis. One of the key regulators of the UP-S is the tripartite motif TRIM protein family, most of which are active E3 ubiquitin ligases. TRIM proteins are critical for the biological functions of cancer cells, including migration, invasion, metastasis, and therapy resistance. Therefore, it is important to understand how TRIM proteins function at the molecular level in cancer cells.

SUMMARY

We provide a comprehensive and up-to-date overview about the role TRIMs play in cancer progression and therapy resistance. We propose TRIM family members as potential new markers and targets to overcome therapy failure.

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.

TRIM58 functions as a tumor suppressor in colorectal cancer by promoting RECQL4 ubiquitination to inhibit the AKT signaling pathway

BACKGROUND

This study aimed to investigate the underlying molecular mechanisms of TRIM58 in the development of colorectal cancer (CRC). CRC is one of the most common cancers of the digestive tract worldwide. The ubiquitin-proteasome system regulates many oncogenic or tumor-suppressive proteins. TRIM58, an E3 ubiquitin ligase and a member of the tripartite motif protein family, is a potential prognostic marker that indicates poor prognosis in cancer. Currently, the precise molecular mechanisms for the TRIM58-mediated CRC progression remain unclear.

METHODS

To examine the effects of TRIM58 on cell viability, cell cycle progression, and apoptosis in CRC, Cell Counting Kit-8 and flow cytometry assays were employed. The AKT inhibitor LY294002 was used to examine the effects of AKT signaling on TRIM58-mediated cell viability, cell cycle progression, and apoptosis in CRC. Additionally, Co-IP and ubiquitination assays were used to examine the correlation between TRIM58 and RECQL4.

RESULTS

TRIM58 overexpression inhibited CRC cell viability and promoted cell cycle arrest and apoptosis, in which the TRIM58 knockdown demonstrated inversed effects via the AKT signaling pathway. TRIM58 inhibited RECQL4 protein levels through its ubiquitin ligase activity, and RECQL4 overexpression inhibited TRIM58 overexpression-mediated CRC cell viability, cell cycle progression, and apoptosis. The downregulation of TRIM58 and upregulation of RECOL4 were observed in human CRC tissue, and TRIM58 demonstrated antitumor effects in CRC-induced tumor growth in a mouse model.

CONCLUSIONS

TRIM58 acts as a tumor suppressor in CRC through the promotion of RECQL4 ubiquitination and inhibition of the AKT signaling pathway and may be investigated for the successful treatment of CRC.

TRIM6 Reduces Ferroptosis and Chemosensitivity by Targeting SLC1A5 in Lung Cancer

Objective

Ferroptosis, a newly identified form of cell death, plays critical roles in the development and chemoresistance of lung cancer. Tripartite motif 6 (TRIM6) acts as an E3-ubiquitin ligase and can promote the progression of human colorectal cancer. The present study is aimed at investigating its role and potential mechanisms in lung cancer.

Methods

Lentiviral vectors were used to overexpress or knock down TRIM6 in human lung cancer cells. Cell survival, colony formation, lipid peroxidation, intracellular iron levels, and other ferroptotic markers were examined. The role of TRIM6 on ferroptosis and chemosensitivity was further tested in mouse tumor xenograft models.

Results

TRIM6 was highly expressed in human lung cancer tissues and cells, and its expression in the lung cancer cells was further increased by ferroptotic stimulation. TRIM6 overexpression inhibited, while TRIM6 silence promoted erastin- and RSL3-induced glutaminolysis and ferroptosis in the lung cancer cells. Mechanistically, TRIM6 directly interacted with solute carrier family 1 member 5 to promote its ubiquitination and degradation, thereby inhibiting glutamine import, glutaminolysis, lipid peroxidation, and ferroptotic cell death. Moreover, we observed that TRIM6 overexpression reduced the chemotherapeutic effects of cisplatin and paclitaxel. In contrast, TRIM6 silence sensitized human lung cancer cells to cisplatin and paclitaxel in vivo and in vitro.

Conclusion

Our findings for the first time define TRIM6 as a negative regulator of ferroptosis in the lung cancer cells, and TRIM6 overexpression enhances the resistance of human lung cancer cells to chemotherapeutic drugs. Overall, targeting TRIM6 may help to establish novel strategies to treat lung cancer.

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.

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.

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.

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.

Activation of PPARγ and inhibition of cell proliferation reduces key proteins associated with the basal subtype of bladder cancer in As3+-transformed UROtsa cells

Environmental exposure to arsenite (As³⁺) has a strong association with the development of human urothelial cancer (UC) and is the 5^th most common cancer in men and the 12^th most common cancer in women. Muscle invasive urothelial cancer (MIUC) are grouped into basal or luminal molecular subtypes based on their gene expression profile. The basal subtype is more aggressive and can be associated with squamous differentiation, characterized by high expression of keratins (KRT1, 5, 6, 14, and 16) and epidermal growth factor receptor (EGFR) within the tumors. The luminal subtype is less aggressive and is predominately characterized by elevated gene expression of peroxisome proliferator-activated receptor- gamma (PPARγ) and forkhead box protein A1 (FOXA1). We have previously shown that As³⁺-transformed urothelial cells (As-T) exhibit a basal subtype of UC expressing genes associated with squamous differentiation. We hypothesized that the molecular subtype of the As-T cells could be altered by inducing the expression of PPARγ and/or inhibiting the proliferation of the cells. Non-transformed and As-T cells were treated with Troglitazone (TG, PPARG agonist, 10 μM), PD153035 (PD, an EGFR inhibitor, 1 μM) or a combination of TG and PD for 3 days. The results obtained demonstrate that treatment of the As-T cells with TG upregulated the expression of PPARγ and FOXA1 whereas treatment with PD decreased the expression of some of the basal keratins. However, a combined treatment of TG and PD resulted in a consistent decrease of several proteins associated with the basal subtype of bladder cancers (KRT1, KRT14, KRT16, P63, and TFAP2A). Our data suggests that activation of PPARγ while inhibiting cell proliferation facilitates the regulation of genes involved in maintaining the luminal subtype of UC. In vivo animal studies are needed to address the efficacy of using PPARγ agonists and/or proliferation inhibitors to reduce tumor grade/stage of MIUC.

ATDC promotes the growth and invasion of hepatocellular carcinoma cells by modulating GSK-3β/Wnt/β-catenin signalling

Accumulating evidence has suggested that the ataxia telangiectasia group D complementing (ATDC) gene is an emerging cancer-related gene in multiple human cancer types. However, little is known about the role of ATDC in hepatocellular carcinoma (HCC). In this study, we aimed to investigate the expression level, biological function and underlying mechanism of ATDC in HCC. The expression of ATDC in HCC cells was detected by quantitative real-time polymerase chain reaction and western blot analysis. Cell growth was determined by cell counting kit-8 assay and colony formation assay. Cell invasion was assessed by Transwell invasion assay. The activation status of Wnt/β-catenin signalling was evaluated by the luciferase reporter assay. Functional experiments showed that the silencing of ATDC expression significantly suppressed the growth and invasion of HCC cells, whereas the overexpression of ATDC promoted the growth and invasion of HCC cells in vitro. Moreover, we showed that ATDC overexpression promoted the phosphorylation of glycogen synthase kinase (GSK)-3β and resulted in the activation of Wnt/β-catenin signalling. Notably, the inhibition of GSK-3β activity significantly abrogated the tumour suppressive effect of ATDC silencing, while the silencing of β-catenin partially reversed the oncogenic effect of ATDC overexpression. Taken together, these findings reveal an oncogenic role of ATDC in HCC and show that the suppression of ATDC impedes the growth and invasion of HCC cells associated with the inactivation of Wnt/β-catenin signalling. Our study suggests that ATDC may serve as a potential therapeutic target for HCC.

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.

MicroRNA-424-5p acts as a potential biomarker and inhibits proliferation and invasion in hepatocellular carcinoma by targeting TRIM29

BACKGROUND

miRNA-424-5p (miR-424-5p) has been implicated in the development and progression of various tumors. However, the functional mechanisms of miR-424-5p in hepatocellular carcinoma (HCC) are unclear. In this study, we investigated the specific biological functions of miRNA in HCC.

METHODS

The expression of miR-424-5p was measured by qRT-PCR in HCC tissues and cell lines. Western blot and immunohistochemistry were used to detect the protein expression level of TRIM29. The relationship between miR-424-5p and the clinicopathological features of HCC patients was analyzed. Cell function experiments were performed to examine proliferation and invasion in HCC cells. The miRNA database was used to predict downstream target genes of miR-424-5p, which were verified by a luciferase reporter assay. Furthermore, cell and animal experiments confirmed that miR-424-5p exerts its biological function through the target gene TRIM29.

RESULTS

miR-424-5p expression was decreased in HCC tissues and cell lines, and correlated with AFP, TNM stage, intrahepatic metastasis and poor overall survival in HCC. The upregulation of miR-424-5p inhibited cell proliferation and invasion in vitro and suppressed HCC tumor growth in vivo. TRIM29 was confirmed to be the downstream target gene of miR-424-5p. Finally, rescue experiments suggested that the upregulation of TRIM29 could rescue inhibitory effect of miR-424-5p overexpression on cell proliferation and migration.

CONCLUSION

miR-424-5p is a tumor suppressor miRNA that inhibits cell proliferation and invasion via directly modulating TRIM29, which is related to cell proliferation and invasion in HCC. Thus, miR-424-5p may be a potential therapeutic and new prognostic marker for HCC.

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

Backgrounds

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

Material/Methods

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

Results

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

Conclusions

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

Expression and the potential functions of TRIM32 in lung cancer tumorigenesis

TRIM32 is a member of the tripartite motif (TRIM) family, which has been associated with tumorigenesis. However, its expression and potential functional role(s) in lung cancer progression have not been fully understood. To evaluate the relationship between the expression of TRIM32 and the prognosis of patients with lung cancer, an independent data set (The Human Protein Atlas website) was introduced. The expression and function analysis of TRIM32 in lung cancer cell lines were also performed by using cell counting kit-8, flow cytometry, transwell, real-time polymerase chain reaction and Western blot analysis. Our data showed that TRIM32 was overexpressed in lung cancer tissues and cell lines and was associated with a poor prognosis. TRIM32 silencing inhibited cell proliferation, migration, invasion, adhesion, and the activation of janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling. The results showed knockdown of TRIM32 in NCI-H446 cells also inhibited cell growth in nude mice in the xenograft model. Additionally, TRIM32 overexpression promoted lung cancer cell proliferation and motility and mediated the expression of Bax, Bcl-2, cleaved caspase-3, matrix metalloproteinase-2 (MMP-2) and MMP-9 were inhibited by JAK2/STAT3 signaling inhibitor (AG490). Taken together, our findings suggest that TRIM32 may regulate lung cancer cell proliferation, apoptosis, and motility through activating the JAK2/STAT3-signaling pathway and may be a novel and promising target for lung cancer.

TRIM52 plays an oncogenic role in ovarian cancer associated with NF-kB pathway

Emerging evidence suggests that the members of the tripartite motif (TRIM) family play a crucial role in cancer development and progression. The purpose of the study was to explore TRIM52's role in tumorigenesis and its potential molecular mechanism in ovarian cancer. The study demonstrated that knockdown of TRIM52 in SKOV3 and CAOV3 cells inhibited ovarian cancer cell invasion, migration, and proliferation, and induced cell apoptosis. On the contrary, overexpression of TRIM52 in HO8910 cells showed contrary results. Further, overexpression of TRIM52 enhanced the expression of phosphorylated IKKβ and IKBα proteins and nuclear protein P65, which implied the activation of NF-kB signal pathway. Knockdown of TRIM52 downregulated the mRNA and protein levels of NF-kB signal downstream effectors of the NF-kB pathway, including MMP9, Bcl2, IL8, and TNFα, but upregulated caspase-3 expression. These results suggested that activation of the NF-kB pathway is involved in TRIM52-mediated regulation in ovarian cancer. The nude mice study further confirmed that knockdown of TRIM52 blocked tumor growth, inhibited cell proliferation, and promoted cell apoptosis. Our data strongly suggested that TRIM52 plays an oncogenic role in ovarian cancer development associated with the NF-kB signal pathway and may be a potential target for cancer therapy.

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

OBJECTIVE

The tripartite motif 66(TRIM66) is an important member of the TRIM protein superfamily, which can participate in the expression of multiple proteins, and is closely associated with the behaviors of non-small cell lung cancer (NSCLC). In this study, we aimed to explore the effect of TRIM66 in this process in vitro using NSCLC cell lines, and the role of TRIM66 in regulating epithelial-mesenchymal transition(EMT) in NSCLC.

METHODS

Western blotting was used to detect the TRIM66 protein expression levels in NSCLC cell lines and normal lung epithelial cells BEAS-2B. We silenced its expression in A549 cells by transient siRNA transfection to ascertain the function of TRIM66 in NSCLC cells. Western blotting was used to detect the expression of EMT-related proteins.

RESULTS

TRIM66 protein content was highest in NSCLC cell line A549, compared with BEAS-2B, it showed that the TRIM66-siRNA group lung cancer cell proliferation was significantly reduced after knockdown of TRIM66, and knockdown of TRIM66 also suppressed invasion, migration and clonogenic ability of A549 cells. Finally, we found that siRNA-mediated TRIM66 silencing suppressed EMT by downregulating expression of N-cadherin and vimentin and upregulating that of E-cadherin in NSCLC cells, which could effectively reduce the invasive, migratory, and proliferative capacities of lung cancer cells.

CONCLUSION

Silence TRIM66 expression suppressed NSCLC cell proliferation, invasion, and migration. The siRNA-mediated TRIM66 silencing could block the occurrence of EMT. TRIM66 could be a promising novel target for future NSCLC treatments.

TRIM66 expression in non-small cell lung cancer: A new predictor of prognosis

OBJECTIVE

The tripartite motif-containing protein (TRIM) family is involved in important biological processes such as the cell cycle, cell apoptosis, and innate immunity of virus. This study aimed to investigate TRIM66 expression and its predictive role in non-small cell lung cancer (NSCLC) patients.

METHODS

We detected the expression levels of TRIM66 protein and TRIM66 mRNA in NSCLC tissues, and evaluated the prognostic role of TRIM66 in NSCLC.

RESULTS

TRIMM66 was highly expressed in NSCLC tissues compared with normal paracancerous tissues (P= 0.001). The high TRIM66 expression closely associated with lymph node metastasis and TNM stage in NSCLC patients (P< 0.05). Kaplan-Meier survival model indicated that survival time of NSCLC patients in the high TRIM66 expression group were markedly lower than those in the low expression group (P< 0.05). Cox regression analysis showed that high expression of TRIM66 is associated with poor prognosis in NSCLC patients.

CONCLUSION

TRIM66 can be serve as an important molecular marker for predicting the prognosis in NSCLC patients.

TRIM29 overexpression is associated with poor prognosis and promotes tumor progression by activating Wnt/β-catenin pathway in cervical cancer

Dysregulation of TRIM29 has been reported to be involved in tumorigenesis, but the role of TRIM29 in cervical cancer is unclear. In this study, we first examined TRIM29 expression and found that TRIM29 mRNA and protein expression was upregulated in cervical cancer tissues when compared with the matched adjacent cervical tissues. We further detected TRIM29 protein with immunohistochemistry in 150 paraffin-embedded samples from early-stage cervical cancer patients. The results showed that high expression of TRIM29 was significantly associated with pelvic lymph node metastasis (p=0.002), advanced FIGO stage (p=0.026) and post-operative recurrence (p<0.001). Patients with high expression of TRIM29 had a shorter overall survival (HR 5.042, p<0.001) and disease-free survival (HR 4.260, p<0.001). TRIM29 was proven to be an independent prognostic factor for cervical cancer patients. When endogenous TRIM29 expression was knocked down by siRNAs, cell proliferation, colony formation, migration and invasion in cervical cancer cell lines HeLa and SiHa were obviously inhibited. Meanwhile, TRIM29 knockdown increased E-cadherin expression but decreased the expression of N-cadherin and β-Catenin, which indicated that TRIM29 could promote epithelial-mesenchymal transition (EMT). Mechanically, knockdown of TRIM29 enhanced GSK-3β protein expression and inhibited the expression of β-Catenin and C-myc proteins. GSK-3β is a key upstream suppressor of β-Catenin and c-myc expression is an indicator of Wnt/β-Catenin activity. Therefore, these results demonstrate that TRIM29 promotes tumor progression by activating Wnt/β-Catenin signaling. In conclusion, TRIM29 is overexpressed and associated with survival of early-stage cervical cancer, indicating that TRIM29 may be a potential prognostic biomarker and therapeutic target for cervical cancer.

GPER promotes tamoxifen-resistance in ER+ breast cancer cells by reduced Bim proteins through MAPK/Erk-TRIM2 signaling axis

Tamoxifen resistance is a major clinical challenge in breast cancer treatment. Our previous studies find that GPER and its down-stream signaling play a pivotal role in the development of tamoxifen (TAM) resistance. cDNA array analysis indicated a set of genes associated with cell apoptosis are aberrant in GPER activated and TAM-resistant MCF-7R cells compared with TAM-sensitive MCF-7 cells. Among these genes, Bim (also named BCL2-L11), a member of the BH3-only pro-apoptotic protein family is significantly decreased, and TRIM RING finger protein TRIM2 (a ubiquitin ligase) is highly expressed in MCF-7R. To understand the mechanism of TAM-resistance in GPER activated ER+ breast cancer, the function of TRIM2 and Bim inducing cell apoptosis was studied. By using immunohistochemical and western blot analysis, there is an adverse correlation between TRIM2 and Bim in TAM-resistant breast tumor tissues and MCF-7R cells. Knockdown Bim in TAM-sensitive MCF-7 cells or overexpression of Bim in TAM-resistant MCF-7 cells significantly changed its sensibility to TAM through altering the levels of cleaved PARP and caspase-3. Activation of GPER and its downstream signaling MAPK/ERK, not PI3K/AKT, led to enhanced TRIM2 protein levels and affected the binding between TRIM2 and Bim which resulted in a reduced Bim in TAM-resistant breast cancer cells. Thus, the present study provides a novel insight to TAM-resistance in ER-positive breast cancer cells.

Role of tripartite motif protein 27 as a gametogenesis-related protein in human germ cells

BACKGROUND

The distribution and functional integrity of members of the tripartite motif (TRIM) protein family are essential for cell proliferation, development and apoptosis, and TRIM proteins have been linked to various cancers. To explore the diagnostic potential and mechanisms of TRIM27 in human spermatogenesis and oogenesis, we analyzed its localization pattern and putative roles in human testes and ovaries.

METHODS

TRIM27 mRNA and protein levels in human testes and ovaries were investigated using RT-PCR and western blotting, respectively. TRIM27 was abundantly transcribed in human testes and ovaries, particularly during the early stages of spermatogenesis, and localized in the nuclei of primary spermatocytes. Immunofluorescence also revealed a diffuse distribution in the cytoplasm of round spermatids, and the protein was abundant in ovary tissue during various stages of oogenesis development.

RESULTS

TRIM27 mRNA and protein was abundantly transcribed in male and female human germ cells by RT-PCR and western blotting in the human testes followed by the ovary. Immunohistochemical results revealed TRIM27 protein was abundant in the sex body of primary spermatocytes undergoing meiotic prophase during the first cycle of spermatogenesis. Moreover, Trim27 was diffusely localized in the cytoplasm of spermatids and round spermatids. Furthermore, TRIM27 was localized to both the nucleus and cytoplasm of human ovary cells.

CONCLUSIONS

TRIM27 as a gametogenesis-related protein could play multiple roles in the regulation of sex body formation and germ cell proliferation during spermatogenesis and oogenesis. The identification and characterization of TRIM27 enhances our understanding of the molecular mechanisms underpinning its functions, and provides insight into its potential role in the pathogenesis of germ cell differentiation and infertility.

Analysis of the expression patterns of the novel large multigene TRIM gene family (finTRIM) in zebrafish

Tripartite motif (TRIM) proteins are receiving increased research interest because of their roles in a wide range of cellular biological processes in innate immunity. In zebrafish (Danio rerio), the functions of the finTRIM (ftr) family are unclear. In the present study, we investigated the expression pattern of ftr12, ftr51, ftr67, ftr82, ftr83, and ftr84 in zebrafish for the first time. The results showed that ftr12, ftr67, and ftr84 are maternally expressed in the oocyte and highly expressed at the early stage (0-4 hpf) of embryo (P < 0.05), suggesting their involvement in the embryonic innate defense system. The ftr82 gene was highly expressed at 8 hpf (P < 0.05), which implied that the embryos could synthesize their own immunity-related mRNAs. However, ftr51 and ftr83 were highest at 8 hpf (2.33 and 51.53 relative to β-actin respectively) and might mediate embryonic development. The expression levels of ftr12, ftr51, and ftr67 were highest in the gill, intestines, and liver, respectively. Ftr82, ftr83, and ftr84 were predominantly expressed in the kidney, suggesting that these finTRIMs might play roles in both immunity and non-immunity-related tissue compartments. Zebrafish embryonic fibroblast (ZF4) cells were infected with Grass carp reovirus (GCRV) and Spring viremia of carp virus (SVCV). During GCRV infection, the expression of ftr12 was significantly upregulated from 12 h to 24 h; and ftr51 and ftr67 increased from 3 h to 12 h. The expressions of ftr82, ftr83, and ftr84 were only upregulated at 12 h, 12 h, and 24 h, respectively. All of these genes were significantly downregulated at 48 h (P < 0.05). Challenge with SVCV upregulated the expressions of ftr12 and ftr51 at 12 h and 48 h (P < 0.05), respectively, and ftr67 reached its highest expression level at 3 h. ftr82 showed only a slight upregulation at 6 h and 48 h, and ftr83 and ftr84 were consecutively increased, reaching their highest levels at 12 h (P < 0.05). Meanwhile, ftr67 and ftr83 were significantly downregulated at 48 h (P < 0.05). Our research demonstrated that ftr12, ftr51, ftr67, ftr82, ftr83, and ftr84 probably have important roles in innate immune responses and in non-immunity-related tissues.

Bioinformatics and expression analysis of finTRIM genes in grass carp, Ctenopharyngodon idella

The tripartite motifs (TRIMs) constitute a large family of proteins containing a Really Interesting New Gene (RING) domain, a B-box domain and coiled-coil region followed by different C-terminal domains. TRIM proteins play multiple roles in various cellular processes, including cell growth, differentiation, apoptosis and antiviral immunity. Fish novel large multigene TRIM genes (finTRIM/ftr) appear only in teleosts and play a vital role in antiviral responses. Phylogenetic analysis revealed the existence of different subsets of novel fish TRIM 14 genes (finTRIM14/ftr14), ftr51, ftr67, ftr72, ftr82, ftr83, and ftr99 in grass carp (Ctenopharyngodon idella), suggesting lineage-specific diversification events. Therefore, the number of finTRIM genes varies greatly among species. The ftr genes in grass carp, which are closely related to zebrafish and possess various evolutionary branches, have evolved faster than human TRIMs. The predicted protein domains were almost identical RING zinc finger domains, with the exception of ftr72, the B-box domain (excluding ftr67, ftr82, ftr83), and the B30.2 domain, which evolved under positive selection (with the exception of ftr67, and ftr72). The genes were predominantly expressed in the spleen, gill and head kidney. These findings indicate that the ftr genes in grass carp are involved diverse cellular processes, including innate immune responses.

A CBR framework with gradient boosting based feature selection for lung cancer subtype classification

Molecular subtype classification represents a challenging field in lung cancer diagnosis. Although different methods have been proposed for biomarker selection, efficient discrimination between adenocarcinoma and squamous cell carcinoma in clinical practice presents several difficulties, especially when the latter is poorly differentiated. This is an area of growing importance, since certain treatments and other medical decisions are based on molecular and histological features. An urgent need exists for a system and a set of biomarkers that provide an accurate diagnosis. In this paper, a novel Case Based Reasoning framework with gradient boosting based feature selection is proposed and applied to the task of squamous cell carcinoma and adenocarcinoma discrimination, aiming to provide accurate diagnosis with a reduced set of genes. The proposed method was trained and evaluated on two independent datasets to validate its generalization capability. Furthermore, it achieved accuracy rates greater than those of traditional microarray analysis techniques, incorporating the advantages inherent to the Case Based Reasoning methodology (e.g. learning over time, adaptability, interpretability of solutions, etc.).

A novel prognostic factor TRIM44 promotes cell proliferation and migration, and inhibits apoptosis in testicular germ cell tumor

Tripartite motif 44 (TRIM44) is one of the TRIM family proteins that are involved in ubiquitination and degradation of target proteins by modulating E3 ubiquitin ligases. TRIM44 overexpression has been observed in various cancers. However, its association with testicular germ cell tumor (TGCT) is unknown. We aimed to investigate the clinical significance of TRIM44 and its function in TGCT. High expression of TRIM44 was significantly associated with α feto-protein levels, clinical stage, nonseminomatous germ cell tumor (NSGCT), and cancer-specific survival (P = 0.0009, P = 0.0035, P = 0.0004, and P = 0.0140, respectively). Multivariate analysis showed that positive TRIM44 IR was an independent predictor of cancer-specific mortality (P = 0.046). Gain-of-function study revealed that overexpression of TRIM44 promoted cell proliferation and migration of NTERA2 and NEC8 cells. Knockdown of TRIM44 using siRNA promoted apoptosis and repressed cell proliferation and migration in these cells. Microarray analysis of NTERA2 cells revealed that tumor suppressor genes such as CADM1, CDK19, and PRKACB were upregulated in TRIM44-knockdown cells compared to control cells. In contrast, oncogenic genes including C3AR1, ST3GAL5, and NT5E were downregulated in those cells. These results suggest that high expression of TRIM44 is associated with poor prognosis and that TRIM44 plays significant role in cell proliferation, migration, and anti-apoptosis in TGCT.

Trim27 interacts with Slx2, is associated with meiotic processes during spermatogenesis

ABSTARCT Formation of the XY body is believed to prevent recombination between X and Y chromosomes during meiosis. We recently demonstrated that SYCP3-like X-linked 2 (Slx2) could be involved in synaptonemal complex formation as well as XY body maintenance during meiosis. In order to further investigate the role and composition of XY body protein complexes in meiotic processes and spermatogenesis, a yeast 2-hybrid screening was performed, and the tripartite motif protein 27(Trim27) was found to interact with Slx2 and co-localized in the XY body. Trim27 has a tripartite motif (TRIM) consisting of a RING finger, B-box and coiled-coil domains, and is a transcriptional regulator that is expressed in various tumor cell lines. In this study, we showed that Slx2 and Trim27 were highly expressed in meiosis of mouse testis. And the Slx2/Trim27 interaction was confirmed in vivo by co-immunoprecipitation and mammalian 2-hybrid interaction assays. Moreover, cytoimmuno localization experiments revealed that Slx2/Trim27 was co-localized to the XY body of spermatocytes during meiosis, and immunohistochemical results revealed co-localization of Trim27 and γ-H2AX in the XY body of primary spermatocytes in the mouse testis. Trim27 may therefore be a transcriptional regulation protein connecting Slx2 and γ-H2AX, thereby promoting the formation of a more potent XY body protein complex in meiotic processes and spermatogenesis. In conclusion, Trim27 connecting Slx2 may regulate meiotic processes in multiple ways by influencing XY body formation and germ cell proliferation during spermatogenesis.

Midline2 is overexpressed and a prognostic indicator in human breast cancer and promotes breast cancer cell proliferation in vitro and in vivo

Midline2 (MID2) is an ubiquitin-conjugating E2 enzyme linked to tumor progression and a novel interacting partner of breast cancer 1, early-onset (BRCA1). However, the role of MID2 in breast cancer remains unknown. This study investigated the expression, prognostic value, and role of MID2 in breast cancer. The expression of MID2 mRNA and protein was significantly upregulated in breast cancer tissue and established cell lines compared with that in normal breast epithelial cells and paired adjacent non-tumor tissue (P < 0.001). Immunohistochemical analysis demonstrated that MID2 was overexpressed in 272 of 284 (95.8%) paraffinembedded, archived breast cancer tissue. Moreover, MID2 expression increased with advanced clinical stage (P < 0.001). High MID2 expression was significantly associated with advanced clinical stages and T, N, and M staging (all P < 0.05). Univariate and multivariate analyses indicated that high MID2 expression was an independent prognostic factor for poor overall survival in the entire cohort (93.73 vs. 172.1 months; P < 0.001, logrank test) and in subgroups with stages Tis + I + II and III + IV. Furthermore, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide colony formation, and anchorage-independent growth ability assays were conducted. Results showed that siRNA silencing of MID2 expression significantly reduced MCF-7 and MDA-MB-231 cell proliferation in vitro and blocked the growth of MDA-MB-231 cell xenograft tumors in vivo (P < 0.05). This study indicated that MID2 may be a novel prognostic marker and interventional target in breast cancer.