Long noncoding ribonucleic acid specific for distant metastasis of gastric cancer is associated with TRIM16 expression and facilitates tumor cell invasion in vitro

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.

Crosstalk between metabolic reprogramming and epigenetics in cancer: updates on mechanisms and therapeutic opportunities

Reversible, spatial, and temporal regulation of metabolic reprogramming and epigenetic homeostasis are prominent hallmarks of carcinogenesis. Cancer cells reprogram their metabolism to meet the high bioenergetic and biosynthetic demands for vigorous proliferation. Epigenetic dysregulation is a common feature of human cancers, which contributes to tumorigenesis and maintenance of the malignant phenotypes by regulating gene expression. The epigenome is sensitive to metabolic changes. Metabolism produces various metabolites that are substrates, cofactors, or inhibitors of epigenetic enzymes. Alterations in metabolic pathways and fluctuations in intermediate metabolites convey information regarding the intracellular metabolic status into the nucleus by modulating the activity of epigenetic enzymes and thus remodeling the epigenetic landscape, inducing transcriptional responses to heterogeneous metabolic requirements. Cancer metabolism is regulated by epigenetic machinery at both transcriptional and post‐transcriptional levels. Epigenetic modifiers, chromatin remodelers and non‐coding RNAs are integral contributors to the regulatory networks involved in cancer metabolism, facilitating malignant transformation. However, the significance of the close connection between metabolism and epigenetics in the context of cancer has not been fully deciphered. Thus, it will be constructive to summarize and update the emerging new evidence supporting this bidirectional crosstalk and deeply assess how the crosstalk between metabolic reprogramming and epigenetic abnormalities could be exploited to optimize treatment paradigms and establish new therapeutic options. In this review, we summarize the central mechanisms by which epigenetics and metabolism reciprocally modulate each other in cancer and elaborate upon and update the major contributions of the interplays between epigenetic aberrations and metabolic rewiring to cancer initiation and development. Finally, we highlight the potential therapeutic opportunities for hematological malignancies and solid tumors by targeting this epigenetic‐metabolic circuit. In summary, we endeavored to depict the current understanding of the coordination between these fundamental abnormalities more comprehensively and provide new perspectives for utilizing metabolic and epigenetic targets for cancer treatment.

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.

Changes in the Expression of Long Non-Coding RNA SDMGC and Its Target Gene, TRIM16, in Patients with Gastric Cancer

PURPOSE

Gastric cancer (GC) has been identified worldwide as one of the most common cancer types with a high mortality rate. LncRNA SDMGC has been recognized as an oncogene with regulatory effects on its target gene, TRIM16, which is believed to play a tumor-suppressing role in various cancers. Both these genes are involved in GC development, tumorigenesis, invasion, and metastasis. The current study is aimed to investigate the association of SDMGC and TRIM16 with GC susceptibility and GC patients' clinicopathological characteristics.

METHODS

A total of 100 GC tissues and their corresponding adjacent non-tumor tissues were sampled. Total RNA was then isolated to measure SDMGC and TRIM16 expression levels using quantitative reverse transcriptase (qRT)-PCR. Statistical analyses including the Mann-Whitney U test and correlation tests were carried out using R v4.5. GraphPad Prism was also used to plot the receiver operating curve (ROC).

RESULTS

The results demonstrated the significant overexpression of lncRNAs SDMGC and downregulation of TRIM16 in GC tissues as compared to their corresponding marginal normal tissue samples (P = 0.005 and P = 0.009, respectively). No association with clinicopathological variables was observed for either SDMGC or TRIM16. Moreover, the results demonstrated a small positive correlation between SDMGC and TRIM16. Evaluation of the diagnostic value of SDMGC and TRIM16 showed poor biomarker potency for these genes.

CONCLUSION

In conclusion, the results indicated an increase in the expression of SDMGC and a decline in the expression pattern of TRIM16 among the Iranian population. The results indicated a key tumor-accelerative function of SDMGC and a pivotal tumor-suppressing role of TRIM16 in GC patients.

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.

Integrated analysis identifies a long non-coding RNAs-messenger RNAs signature for prediction of prognosis in hepatitis B virus-hepatocellular carcinoma patients

Hepatitis B virus (HBV) infection is a leading cause of hepatocellular carcinoma (HCC), but HBV-HCC related prognosis signature remains rarely investigated. This study was to identify an integrated long non-coding RNAs-messenger RNAs (lncRNA-mRNA) signature for prediction of overall survival (OS) and explore their underlying functions.One RNA-sequencing dataset (training set, n = 95) and one microarray dataset E-TABM-36 (validation set, n = 44) were collected. Least absolute shrinkage and selection operator analysis was performed to identify an lncRNA-mRNA prognosis signature. The OS difference of patients in the high-risk and low-risk risk groups was evaluated by Kaplan-Meier curve. Area under the receiver operating characteristic curve (AUC), Harrell concordance index (C-index) calculation, and multivariate analyses with clinical characteristics were used to determine the prognostic ability. Furthermore, a coexpression network was constructed to interpret the functions.Nine signature genes (3 lncRNAs and 6 mRNAs) were selected to generate the risk score model. Patients belonging to the high-risk group showed a significantly shorter survival than those of the low-risk group. The prediction accuracy of the risk score for 5-year OS was 0.936 and 0.905 for the training set and validation set, respectively. Also, this risk score was independent of various clinical variables for the prognosis prediction. Incorporation of the risk score remarkably increased the predictive power of the routine clinical prognostic factors (vascular invasion status, tumor recurrence status) (AUC = 0.942 vs 0.628; C-index = 0.7997 vs 0.6908). Furthermore, LncRNA insulin-like growth factor 2 antisense RNA (IGF2-AS) and long intergenic non-protein coding RNA 342 (LINC00342) were predicted to exert tumor suppression effects by regulating homeobox D1 (HOXD1) and secreted frizzled related protein 5 (SFRP5), respectively; while lncRNA rhophilin Rho GTPase binding protein 1 antisense RNA 1 (RHPN1-AS1) may possess carcinogenic potential by promoting the transcription of chromobox 2 (CBX2), cell division cycle 20 (CDC20), matrix metallopeptidase 12 (MMP12), stratifin (SFN), tripartite motif containing 16 (TRIM16), and uroplakin 3A (UPK3A). These mRNAs may be associated with cell proliferation or apoptosis related pathways.This study may provide a novel, effective prognostic biomarker, and some therapeutic targets for HBV-HCC patients.

Non-coding RNAs: the new central dogma of cancer biology

The central dogma of molecular biology states that the functions of RNA revolve around protein translation. Until the last decade, most researches were geared towards characterization of RNAs as intermediaries in protein translation, namely, messenger RNAs (mRNAs) as temporary copies of genetic information, ribosomal RNAs (rRNAs) as a main component of ribosome, or translators of codon sequence (tRNAs). The statistical reality, however, is that these processes account for less than 2% of the genome, and insufficiently explain the functionality of 98% of transcribed RNAs. Recent discoveries have unveiled thousands of unique non-coding RNAs (ncRNAs) and shifted the perception of them from being "junk" transcriptional products to "yet to be elucidated"-and potentially monumentally important-RNAs. Most ncRNAs are now known as key regulators in various networks in which they could lead to specific cellular responses and fates. In major cancers, ncRNAs have been identified as both oncogenic drivers and tumor suppressors, indicating a complex regulatory network among these ncRNAs. Herein, we provide a comprehensive review of the various ncRNAs and their functional roles in cancer, and the pre-clinical and clinical development of ncRNA-based therapeutics. A deeper understanding of ncRNAs could facilitate better design of personalized therapeutics.

TRIM16 protects from OGD/R-induced oxidative stress in cultured hippocampal neurons by enhancing Nrf2/ARE antioxidant signaling via downregulation of Keap1

Tripartite motif 16 (TRIM16) has emerged as a novel oxidative stress-responsive protein that confers cytoprotective effects by reinforcing the cellular antioxidant system. However, whether TRIM16 is involved in regulating oxidative stress during cerebral ischemia/reperfusion injury remains unclear. In the present study, we aimed to explore the potential function and molecular mechanism of TRIM16 in regulating oxidative stress in neurons induced by oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro. Here, we found that OGD/R exposure resulted in a significant induction of TRIM16 expression in neurons. Depletion of TRIM16 by siRNA-mediated gene knockdown markedly upregulated the sensitivity of neurons to OGD/R-induced apoptosis and reactive oxygen species (ROS) generation. Notably, upregulation of TRIM16 expression significantly alleviated OGD/R-induced apoptosis and ROS generation in neurons. Moreover, TRIM16 overexpression markedly increased nuclear factor erythroid 2-related factor 2 (Nrf2) expression and enhanced Nrf2/antioxidant response element (ARE) activation associated with downregulation of kelch-like ECH-associated protein 1 (Keap1) expression. Restoration of Keap1 significantly reversed the TRIM16-mediated promotion effect on Nrf2/ARE activation. In addition, knockdown of Nrf2 also markedly abrogated the TRIM16-conferred neuroprotective effect in OGD/R-exposed neurons. Taken together, our results of our study demonstrate that induction of TRIM16 confers a cytoprotective effect in OGD/R-exposed neurons through enhancement of Nrf2/ARE antioxidant signaling via downregulation of Keap1. These findings suggest that TRIM16 may play a critical role in cerebral ischemia/reperfusion injury and serve as a promising target for neuroprotection.

Long non-coding RNA signature in gastric cancer

Gastric cancer as a common human malignancy has been associated with aberrant expressions of several coding and non-coding genes. Long non-coding RNAs (lncRNAs) as regulators of gene expressions at different genomic, transcriptomic and post-transcriptomic levels are among putative biomarkers and therapeutic targets in gastric cancer. In the present study, we have searched available literature and listed lncRNAs that are involved in the pathogenesis of gastric cancer. In addition, we discuss associations between expressions of these lncRNAs and tumoral features or risk factors for gastric cancer. Based on the established role of lncRNAs in regulation of genomic stability, cell cycle, apoptosis, angiogenesis and other aspects of cell physiology, the potential of these transcripts as therapeutic targets in gastric cancer should be evaluated in future studies.

Long non-coding RNA urothelial cancer associated 1 can regulate the migration and invasion of colorectal cancer cells (SW480) via myocardin-related transcription factor-A

Colorectal cancer (CRC) is the third leading cause of cancer-associated mortalities. Long non-coding RNAs (lncRNAs) have been identified as key regulators in the occurrence and development of CRC. The lncRNA urothelial cancer associated 1 (UCA1) has been demonstrated to promote the development of numerous different types of cancer. In the present study, a novel molecular mechanism of UCA1, regulating the migratory and invasive capabilities of SW480 CRC cells was identified. UCA1 promoted the migration and invasion of SW480 cells by suppressing phosphorylation of myocardin-related transcription factor-A (MRTF-A). Our findings indicated that UCA1 competes with extracellular signal-regulated kinases1/2 to inhibit the phosphorylation of MRTF-A. These novel discoveries may reveal additional functions of UCA1, which may support future clinical development of novel drug targets.

LncRNAs with miRNAs in regulation of gastric, liver, and colorectal cancers: updates in recent years

Long noncoding RNA (lncRNA) is a kind of RNAi molecule composed of hundreds to thousands of nucleotides. There are several major types of functional lncRNAs which participate in some important cellular pathways. LncRNA-RNA interaction controls mRNA translation and degradation or serves as a microRNA (miRNA) sponge for silencing. LncRNA-protein interaction regulates protein activity in transcriptional activation and silencing. LncRNA guide, decoy, and scaffold regulate transcription regulators of enhancer or repressor region of the coding genes for alteration of expression. LncRNA plays a role in cellular responses including the following activities: regulation of chromatin structural modification and gene expression for epigenetic and cell function control, promotion of hematopoiesis and maturation of immunity, cell programming in stem cell and somatic cell development, modulation of pathogen infection, switching glycolysis and lipid metabolism, and initiation of autoimmune diseases. LncRNA, together with miRNA, are considered the critical elements in cancer development. It has been demonstrated that tumorigenesis could be driven by homeostatic imbalance of lncRNA/miRNA/cancer regulatory factors resulting in biochemical and physiological alterations inside the cells. Cancer-driven lncRNAs with other cellular RNAs, epigenetic modulators, or protein effectors may change gene expression level and affect the viability, immortality, and motility of the cells that facilitate cancer cell cycle rearrangement, angiogenesis, proliferation, and metastasis. Molecular medicine will be the future trend for development. LncRNA/miRNA could be one of the potential candidates in this category. Continuous studies in lncRNA functional discrepancy between cancer cells and normal cells and regional and rational genetic differences of lncRNA profiles are critical for clinical research which is beneficial for clinical practice.

Long non-coding RNAs in metastasis

Long non-coding RNA (lncRNA) genes have recently been discovered as key regulators of developmental, physiological, and pathological processes in humans. Recent studies indicate that lncRNAs regulate every step of gene expression, and their aberrant expression can be found in the majority of cancer types. Particularly, lncRNAs were found to function in tumor development and metastasis, which is the major cause of cancer-related death. Thus, exploring key roles of lncRNAs in metastasis is predicted to enhance our knowledge of metastasis, and uncover novel therapeutic targets and biomarkers of this process. In this review, we discuss the molecular mechanisms of lncRNAs in gene expression regulation and their function in metastasis.

Molecular mechanisms of long noncoding RNAs on gastric cancer

Long noncoding RNAs (lncRNAs) are non-protein coding transcripts longer than 200 nucleotides. Aberrant expression of lncRNAs has been found associated with gastric cancer, one of the most malignant tumors. By complementary base pairing with mRNAs or forming complexes with RNA binding proteins (RBPs), some lncRNAs including GHET1, MALAT1, and TINCR may mediate mRNA stability and splicing. Other lncRNAs, such as BC032469, GAPLINC, and HOTAIR, participate in the competing endogenous RNA (ceRNA) network. Under certain circumstances, ANRIL, GACAT3, H19, MEG3, and TUSC7 exhibit their biological roles by associating with microRNAs (miRNAs). By recruiting histone-modifying complexes, ANRIL, FENDRR, H19, HOTAIR, MALAT1, and PVT1 may inhibit the transcription of target genes in cis or trans. Through these mechanisms, lncRNAs form RNA-dsDNA triplex. CCAT1, GAPLINC, GAS5, H19, MEG3, and TUSC7 play oncogenic or tumor suppressor roles by correlated with tumor suppressor P53 or onco-protein c-Myc, respectively. In conclusion, interaction with DNA, RNA and proteins is involved in lncRNAs' participation in gastric tumorigenesis and development.

TRIM16 suppresses the progression of prostate tumors by inhibiting the Snail signaling pathway

Prostate carcinoma is a devastating disease which is characterized by insidious early symptoms, rapid progression and a poor prognosis. Tripartite motif-containing protein 16 (TRIM16) was identified as an estrogen- and antiestrogen-regulated gene in epithelial cells stably expressing estrogen receptors. The protein encoded by this gene contains two B-box domains and a coiled-coiled region that are characteristic of the B-box zinc finger protein family. Proteins belonging to this family have been reported to be involved in a variety of biological processes including cell growth, differentiation and pathogenesis. TRIM16 expression has been detected in most tissues. However, the funtions of this gene remain to be elucidated. In the present study, immunohistochemical staining revealed that the expression of TRIM16 was decreased in prostate adenocarcinoma compared with that in normal prostate tissues. The patients with high TRIM16-expressing tumors had a significantly greater survival than those with low TRIM16-expressing tumors. Western blot analysis showed that TRIM16 was downregulated in distant metastatic cancer tissues compared with that in non-distant metastatic cancer tissues. The overexpression of TRIM16 inhibited the migration and invasion of prostate cancer cells as well as inhibiting the epithelial-to-mesenchymal transition process, whereas TRIM16 depletion enhanced these processes. Moreover, TRIM16 inhibited the Snail signaling pathway. The silencing of Snail by small interfering RNA was performed in order to determine the role of Snail in the TRIM16-mediated tumor phenotype. Taken together, these findings suggest that TRIM16 may be an important molecular target which may aid in the design of novel therapeutic agents for prostate cancer.

Long non-coding RNAs: potential new biomarkers for predicting tumor invasion and metastasis

Long non-coding RNAs (lncRNAs) play important roles in malignant neoplasia. Indeed, many hallmarks of cancer define that the malignant phenotype of tumor cells are controlled by lncRNAs. Despite a growing number of studies highlighting their importance in cancer, there has been no systematic review of metastasis-associated lncRNAs in various cancer types. Accordingly, we focus on the key metastasis-related lncRNAs and outline their expression status in cancer tissues by reviewing the previous stuides, in order to summarize the nowadays research achivements for lncRNAs related to cancer metastasis. Medline, EMBASE, as well as PubMed databases were applied to study lncRNAs which were tightly associated with tumor invasion and metastasis. Up to now, a substantial number of lncRNAs have been found to have important biological functions. In this review, according to their various features in cancer, lncRNAs were roughly divided into three categories: promoting tumor invasion and metastasis, negative regulation of tumor metastasis and with dual regulatory roles. The present studies may establish the foundation for both further research on the mechanisms of cancer progression and future lncRNA-based clinical applications.

Dysregulation of non-coding RNAs in gastric cancer

Gastric cancer (GC) is one of the most common cancers in the world and a significant threat to the health of patients, especially those from China and Japan. The prognosis for patients with late stage GC receiving the standard of care treatment, including surgery, chemotherapy and radiotherapy, remains poor. Developing novel treatment strategies, identifying new molecules for targeted therapy, and devising screening techniques to detect this cancer in its early stages are needed for GC patients. The discovery of non-coding RNAs (ncRNAs), primarily microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), helped to elucidate the mechanisms of tumorigenesis, diagnosis and treatment of GC. Recently, significant research has been conducted on non-coding RNAs and how the regulatory dysfunction of these RNAs impacts the tumorigenesis of GC. In this study, we review papers published in the last five years concerning the dysregulation of non-coding RNAs, especially miRNAs and lncRNAs, in GC. We summarize instances of aberrant expression of the ncRNAs in GC and their effect on survival-related events, including cell cycle regulation, AKT signaling, apoptosis and drug resistance. Additionally, we evaluate how ncRNA dysregulation affects the metastatic process, including the epithelial-mesenchymal transition, stem cells, transcription factor activity, and oncogene and tumor suppressor expression. Lastly, we determine how ncRNAs affect angiogenesis in the microenvironment of GC. We further discuss the use of ncRNAs as potential biomarkers for use in clinical screening, early diagnosis and prognosis of GC. At present, no ideal ncRNAs have been identified as targets for the treatment of GC.