Expression of eukaryotic translation initiation factor 5A-2 (eIF5A-2) associated with poor survival in gastric cancer

Prognostic value of EIF5A2 in solid tumors: A meta-analysis and bioinformatics analysis

Aims

In cancer biology, the aberrant overexpression of eukaryotic translation initiation factor 5A2 (EIF5A2) has been correlative with an ominous prognosis, thereby underscoring its pivotal role in fostering metastatic progression. Consequently, EIF5A2 has garnered significant attention as a compelling prognostic biomarker for various malignancies. Our research endeavors were thus aimed at elucidating the utility and significance of EIF5A2 as a robust indicator of cancer outcome prediction.

Method

An exhaustive search of the PubMed, EMBASE, and Web of Science databases found relevant studies. The link between EIF5A2 and survival prognosis was examined using hazard ratios and 95% confidence intervals. Subsequently, The Cancer Genome Atlas (TCGA) and the Gene Expression Profiling Interactive Analysis (GEPIA) databases were employed to validate EIF5A2 expression across various cancer types.

Results

Through pooled analysis, we found that increased EIF5A2 expression was significantly associated with decreased overall survival (OS) and disease-free survival/progression-free survival/relapse-free survival (DFS/PFS/RFS). Moreover, TCGA analysis revealed that EIF5A2 was significantly upregulated in 27 types of cancer, with overexpression being linked to shorter OS in three, worse DFS in two, and worse PFS in six types of cancer. GEPIA showed that patients with EIF5A2 overexpression had reduced OS and DFS.

Conclusions

In solid tumors, EIF5A2 emerges as a reliable prognostic marker. Our meta-analysis comprehensively analyzed the prognostic value of EIF5A2 in solid tumors and assessed its efficacy as a predictive marker.

High eukaryotic initiation factor 5A2 expression predicts poor prognosis and may participate in the SNHG16/miR-10b-5p/EIF5A2 regulatory axis in head and neck squamous cell carcinoma

BACKGROUND

This study attempted to investigate the significance of eukaryotic initiation factor 5A2 (EIF5A2) in the prognosis and regulatory network of head and neck squamous cell carcinoma (HNSCC).

METHODS

EIF5A2 expression, prognostic information, and methylation levels of HNSCC were collected from the Cancer Genome Atlas (TCGA) database. Quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) and Western blot analyses were performed to determine EIF5A2 levels in HNSCC and normal tissue samples. R software was employed for expression analysis and prognosis assessment of EIF5A2 in HNSCC. A competing endogenous RNA (ceRNA) network was generated with the starBase database. Gene set enrichment analysis (GSEA) was used to determine the enriched physiological functions and network related to high expression of EIF5A2 in HNSCC. Immune infiltration-related outcomes were acquired from the CIBERSORT and Tumor Immune Estimation Resource (TIMER) database.

RESULTS

EIF5A2 overexpression was observed in HNSCC and linked to poor progression-free survival and overall survival time. Cox regression analyses showed that EIF5A2 level was a stand-alone indicator of HNSCC patients' prognosis. A ceRNA network analysis highlighted the SNHG16/miR-10b-5p/EIF5A2 axis in EIF5A2 regulation. The GSEA results indicated that EIF5A2 was involved in complex signaling pathways. The CIBERSORT and TIMER databases revealed significant associations between EIF5A2 expression and immune cell infiltration.

CONCLUSION

EIF5A2 overexpression may be a risk factor for prognosis in HNSCC and may be regulated by the SNHG16/miR-10b-5p/EIF5A2 axis.

EIF5A2 promotes proliferation and invasion of intrahepatic cholangiocarcinoma cells

PURPOSE

Intrahepatic cholangiocarcinoma (ICC) can invade and metastasize. EIF5A2 is involved in the invasive metastatic process of several digestive malignancies. However, its role in ICC is yet to be elucidated.

METHODS

Immunohistochemistry (IHC) and Western blot (WB) were used to detect the level of EIF5A2 in the tumor specimens of ICC patients and evaluate the correlation between its expression and clinicopathological characteristics. The significance of EIF5A2 in the prognosis of ICC patients was further evaluated by Kaplan-Meier and Cox regression analysis. In addition, CCK-8, EdU, Transwell invasion, and scratch assays were utilized to detect tumor cell proliferation, invasion, and metastasis. Furthermore, the role of EIF5A2 in ICC cells was evaluated after modification of EIF5A2 expression.

RESULTS

The level of EIF5A2 protein was significantly higher in ICC than in adjacent tissues. This high expression in the tumor samples was significantly associated with malignant phenotypes, such as lymph node metastasis (LNM), microvascular or bile duct invasion, and poor differentiation. ICC patients with high expression of EIF5A2 had short overall survival and a high cumulative recurrence rate. The multifactorial analysis showed that EIF5A2 is an independent prognostic marker. Furthermore, high levels of EIF5A2 may activate the PI3K/AKT/mTOR signaling pathway and upregulate Cyclin D1, Cyclin D3, MMP2, and MMP9 to promote ICC cell proliferation, migration, and invasion.

CONCLUSION

The current study found that EIF5A2 promotes ICC progression and is a prognostic biomarker and candidate therapeutic target for ICC patients.

Eukaryotic Translation Initiation Factor 5A Independently Predicts Poor Prognosis of Cholangiocarcinoma Patients and Regulates the Ferroptosis and Mitochondrial Apoptosis

Cholangiocarcinoma (CCA) is a hepatobiliary carcinoma characterized by the differentiation of bile duct cells, and the patients with CCA often have a poor prognosis. Eukaryotic translation initiation factor 5A (eIF5A) is reported to have multiple biological activities. Targeted activation of ferroptosis may be a therapeutic strategy for cancer. Nevertheless, the effects of eIF5A and ferroptosis on CCA are still elucidated. Our study explored the effects of eIF5A in CCA, and the mechanisms also are studied. In this paper, TCGA database analysis suggested that eIF5A was upregulated in CCA, and high expression of eIF5A might predict a poor prognosis. Moreover, FANCD2, SLC7A11, and HSPB1 were significantly overexpressed in CCA. The results indicated that eIF5A was overexpressed in CCA tissues and cells. Further experiments demonstrated that eIF5A silencing decreased CCA cell activity and enhanced ferroptosis and mitochondrial apoptosis. In addition, upregulation of eIF5A showed the opposite effect on CCA cells compared with downregulation of eIF5A. Finally, the silencing of eIF5A could restrain the growth of xenografted tumors and promote ferroptosis. Overall, eIF5A enlarged CCA cell activity and attenuated ferroptosis and mitochondrial apoptosis. The results suggested that assessment of eIF5A might provide help for the diagnosis and treatment of CCA.

The deubiquitinating enzyme ATXN3 promotes the progression of anaplastic thyroid carcinoma by stabilizing EIF5A2

Ataxin-3 (ATXN3) is a ubiquitous deubiquitinating enzyme that plays an essential role in the carcinogenesis of numerous tumors and stabilizes the expression of substrates by deubiquitination. However, the functional role of ATXN3 in anaplastic thyroid carcinoma (ATC) remains unknown. In this research, we report that ATXN3 was overexpressed in ATC compared to that in paracancerous samples. Moreover, various gain/loss functional assays were performed to indicate that ATXN3 overexpression enhanced ATC cell proliferation and metastasis. We also found that ATXN3 and eukaryotic translation initiation factor 5A2 (EIF5A2) protein levels in ATC tissues are positively correlated, and ATXN3 promotes the proliferation and metastasis of ATC cells through EIF5A2. Mechanistically, ATXN3 promotes EIF5A2 expression by directly binding to EIF5A2 to reduce its ubiquitination and degradation. Therefore, for the first time, we clarified the role of ATXN3 in the carcinogenesis of ATC cells, which provides novel insights into potential therapeutic targets for ATC progression.

Eukaryotic translation initiation factor 5A in the pathogenesis of cancers

Cancer is the leading cause of death worldwide. The absence of obvious symptoms and insufficiently sensitive biomarkers in early stages of carcinoma limits early diagnosis. Cancer therapy agents and targeted therapy have been used extensively against tissues or organs of specific cancers. However, the intrinsic and/or acquired resistance to the agents or targeted drugs as well as the serious toxic side effects of the drugs would limit their use. Therefore, identifying biomarkers involved in tumorigenesis and progression represents a challenge for cancer diagnosis and therapeutic strategy development. The eukaryotic translation factor 5A (eIF5A), originally identified as an initiation factor, was later shown to promote translation elongation of iterated proline sequences. There are two eIF5A isoforms (eIF5A1 and eIF5A2). eIF5A2 protein consists of 153 residues, and shares 84% amino acid identity with eIF5A1. However, the biological functions of these two isoforms may be significantly different. Recently, it was demonstrated that eIF5Ais widely involved in the pathogenesis of a number of diseases, including cancers. In particular, eIF5A plays an important role in regulating tumor growth, invasion, metastasis and tumor microenvironment. It was also shown to serve as a potential biomarker and target for the diagnosis and treatment of cancers. The present review briefly discusses the latest findings of eIF5A in the pathogenesis of certain malignant cancers and evolving clinical applications.

Recent insights into eukaryotic translation initiation factors 5A1 and 5A2 and their roles in human health and disease

The eukaryotic translation initiation factor 5A1 (eIF5A1) and its homolog eIF5A2 are the only two human proteins containing the unique post-translational modification-hypusination, which is essential for the function of these two proteins. eIF5A1 was initially identified as a translation initiation factor by promoting the first peptide bond formation of protein during translation; however, recent results suggest that eIF5A1 also functions as a translation elongation factor. It has been shown that eIF5A1 is implicated in certain human diseases, including diabetes, several human cancer types, viral infections and diseases of neural system. Meanwhile, eIF5A2 is overexpressed in many cancers, and plays an important role in the development and progression of cancers. As multiple roles of these two factors were observed among these studies, therefore, it remains unclear whether they act as oncogene or tumor suppressor. In this review, the recent literature of eIF5As and their roles in human diseases, especially in human cancers, will be discussed.

Thermo-chemotherapy inhibits the proliferation and metastasis of gastric cancer cells via suppression of EIF5A2 expression

Purpose

Thermo-chemotherapy (TCT) is a new approach for the treatment of cancer that combines chemotherapy with thermotherapy. In the present study, we investigated the relationship between eukaryotic translation initiation factor 5A2 (EIF5A2) and TCT sensitivity in gastric cancer (GC) to further illuminate the molecular mechanism underlying the effect of TCT on GC.

Methods

A TCT cell model was constructed, and EIF5A2 was silenced or overexpressed by infection with a lentivirus expressing either EIF5A2 or EIF5A2 shRNA. Then, RT-qPCR, Western blotting, and immunohistochemistry assays were performed to evaluate the changes in the expression levels of EIF5A2, c-myc, vimentin, and E-cadherin. Cell proliferation and xenograft assays were conducted to evaluate the effect on cell proliferation. Finally, wound-healing and Transwell invasion assays were performed to evaluate the effects on migration and invasion.

Results

TCT reduced EIF5A2 expression at both the mRNA and protein levels. It also inhibited cell proliferation, migration, and invasion, downregulated the expression of c-myc and vimentin, and increased the expression of E-cadherin in both MKN28 and MKN45 cells. Silencing of EIF5A2 enhanced the above effects of TCT on MKN28 and MKN45 cells, while overexpression of EIF5A2 had the opposite effects. In addition, EIF5A2 overexpression weakened the inhibitory effect of TCT on tumor growth in vivo as well as the effects on c-myc, vimentin, and E-cadherin.

Conclusion

TCT inhibits GC cell proliferation and metastasis by suppressing EIF5A2 expression. Our results provide new insights into our understanding of the molecular mechanism underlying the effects of TCT in GC.

Eukaryotic initiation factor 5A2 and human digestive system neoplasms

Eukaryotic initiation factor 5A2 (eIF5A2), as one of the two isoforms in the family, is reported to be a novel oncogenic protein that is involved in multiple aspects of many types of human cancer. Overexpression or gene amplification of EIF5A2 has been demonstrated in many cancers. Accumulated evidence shows that eIF5A2 initiates tumor formation, enhances cancer cell growth, increases cancer cell metastasis, and promotes treatment resistance through multiple means, including inducing epithelial–mesenchymal transition, cytoskeletal rearrangement, angiogenesis, and metabolic reprogramming. Expression of eIF5A2 in cancer correlates with poor survival, advanced disease stage, as well as metastasis, suggesting that eIF5A2 function is crucial for tumor development and maintenance but not for normal tissue homeostasis. All these studies suggest that eIF5A2 is a useful biomarker in the prediction of cancer prognosis and serves as an anticancer molecular target. This review focuses on the expression, subcellular localization, post-translational modifications, and regulatory networks of eIF5A2, as well as its biochemical functions and evolving clinical applications in cancer, especially in human digestive system neoplasms.

Overexpression of eukaryotic initiation factor 5A (eIF5A) affects susceptibility to benznidazole in Trypanosoma cruzi populations

Eukaryotic initiation factor 5A (eIF5A) is a conserved protein with an essential role in translation elongation. Using one and two-dimensional western blotting, we showed that the eIF5A protein level was 2-fold lower in benznidazole (BZ)-resistant (BZR and 17LER) Trypanosoma cruzi populations than in their respective susceptible counterparts (BZS and 17WTS). To confirm the role of eIF5A in BZ resistance, we transfected BZS and 17WTS with the wild-type eIF5A or mutant eIF5A-S2A (in which serine 2 was replaced by alanine). Upon overexpressing eIF5A, both susceptible lines became approximately 3- and 5-fold more sensitive to BZ. In contrast, the eIF5A-S2A mutant did not alter its susceptibility to BZ. These data suggest that BZ resistance might arise from either decreasing the translation of proteins that require eIF5A, or as a consequence of differential levels of precursors for the hypusination reactions (e.g., spermidine and trypanothione), both of which alter BZ's effects in the parasite.

Increased expression of high-mobility group A2: A novel independent indicator of poor prognosis in patients with esophageal squamous cell carcinoma

PURPOSE

Although high-mobility group A2 (HMGA2) protein has been reported to participate in cancer progression and metastasis, its clinical relationship with tumor invasion, lymph node metastasis, and prognosis in esophageal squamous cell carcinoma (ESCC) remains unclear. The purpose of this study is to analyze the clinical and prognostic significance of HMGA2 in ESCC patients after curative resection.

MATERIALS AND METHODS

The expression of HMGA2 protein was evaluated by using immunohistochemistry in a tissue microarray (TMA) containing ESCC lesions and adjacent normal esophageal epithelial tissues from 96 patients who had undergone curative resection. TMA was constructed by Shanghai Biochip Co. Ltd., Shanghai, China. The relationship between HMGA2 expression and clinicopathological parameters and prognosis was further analyzed.

RESULTS

HMGA2 expression was significantly higher in ESCC tissues compared with that of the adjacent noncancerous tissues (P < 0.001). High expression of HMGA2 was significantly related to tumor size, lymph node metastasis, and advanced tumor-node-metastasis stage (P < 0.05). Patients with low expression of HMGA2 had a better prognosis than those with high expression (χ2 = 5.069, P = 0.024). Univariate analysis showed that age (P = 0.041), depth of tumor invasion (P = 0.031), lymph node status (P = 0.001), and HMGA2 expression (P = 0.024) were correlated with prognosis. Multivariate analysis showed that HMGA2 expression (hazard ratio [HR]: 0.539; 95% confidence interval [95% CI]: 0.302-0.963, P = 0.037) and lymph node metastasis (HR: 0.504; 95% CI: 0.310-0.820, P = 0.006) were independent prognostic factors for overall survival.

CONCLUSIONS

High HMGA2 expression was related to lymph node metastasis and poor prognosis in ESCC. Our results indicated that HMGA2 could act as a potential biomarker for prognosis evaluation of ESCC patients.