TNFAIP2 as an emerging therapeutic target in cancer therapy and its underlying mechanisms.

TNFα-induced protein 2 (TNFAIP2), upregulated under TNFα stimulation, was initially thought to participate in angiogenesis. Still, more and more studies have found that TNFAIP2 plays multiple roles in various physiological and pathological scenarios. The representative functions of TNFAIP2 include motivating the inflammatory response, promoting angiogenesis, facilitating cell proliferation, adhesion, migration, and inducing tunnel nanotube formation. The expression of TNFAIP2 is abnormal in most cancers and can enhance drug resistance in cancer cells. The increasingly recognized significance of TNFAIP2 has been attracting growing attention in recent years. This review focuses on elucidating the relationship between TNFAIP2 and oncogenesis, as well as the latest research advancements in the pharmacological targeting of TNFAIP2, aiming to guide forthcoming endeavors in developing pharmacological agents targeted at modulating TNFAIP2.

Targeting TNFAIP2 induces immunogenic cell death and sensitizes glioblastoma multiforme to anti-PD-1 therapy.

BACKGROUND: The efficacy of current immunotherapeutic strategies for patients with glioblastoma multiforme (GBM) remains unsatisfactory. The purpose of this study was to investigate the correlation between tumor necrosis factor alpha-induced protein 2 (TNFAIP2) and immunogenic cell death (ICD) in GBM, and to examine the effect of TNFAIP2 knockdown and anti-PD-1 combination treatment in a mouse glioma model. METHODS: The CGGA and TCGA databases were used to explore the possible function of TNFAIP2 in GBM. Multiplex immunohistochemistry (mIHC) staining was performed to detect the immune infiltration of tissues. Western blot, quantitative real-time polymerase chain reaction (qRT-PCR), flow cytometry, and enzyme linked immunosorbent assay (ELISA) were utilized to detect the release of damage-associated molecular patterns (DAMPs) and the activation of the immune response. A mouse glioma model was applied to examine the induction of immune response. RESULTS: In vitro and in vivo studies demonstrated that TNFAIP2 knockdown increased the surface exposure of calreticulin (CALR), heat shock protein 70 kDa (HSP70), and heat shock protein 90 kDa (HSP90) in GBM cell lines, thereby inducing immunogenic cell death (ICD). Importantly, the study found that TNFAIP2 knockdown in combination with anti-PD-1 therapy significantly improved the overall survival of glioma in a mouse model. CONCLUSIONS: TNFAIP2 knockdown induces ICD by downregulating TNFAIP2 in GBM. In addition, TNFAIP2 knockdown sensitized glioma to anti-PD-1 therapy. Hence, targeting TNFAIP2 alone or in combination with anti-PD-1 therapy may be a potential strategy for GBM treatment through ICD.

Tnfaip2/exoc3-driven lipid metabolism is essential for stem cell differentiation and organ homeostasis.

Lipid metabolism influences stem cell maintenance and differentiation but genetic factors that control these processes remain to be delineated. Here, we identify Tnfaip2 as an inhibitor of reprogramming of mouse fibroblasts into induced pluripotent stem cells. Tnfaip2 knockout impairs differentiation of embryonic stem cells (ESCs), and knockdown of the planarian para-ortholog, Smed-exoc3, abrogates in vivo tissue homeostasis and regeneration-processes that are driven by somatic stem cells. When stimulated to differentiate, Tnfaip2-deficient ESCs fail to induce synthesis of cellular triacylglycerol (TAG) and lipid droplets (LD) coinciding with reduced expression of vimentin (Vim)-a known inducer of LD formation. Smed-exoc3 depletion also causes a strong reduction of TAGs in planarians. The study shows that Tnfaip2 acts epistatically with and upstream of Vim in impairing cellular reprogramming. Supplementing palmitic acid (PA) and palmitoyl-L-carnitine (the mobilized form of PA) restores the differentiation capacity of Tnfaip2-deficient ESCs and organ maintenance in Smed-exoc3-depleted planarians. Together, these results identify a novel role of Tnfaip2 and exoc3 in controlling lipid metabolism, which is essential for ESC differentiation and planarian organ maintenance.

Screening UFMylation-associated genes in heart tissues of Ufm1-transgenic mice.

UFMylation is a ubiquitination-like modification that is related to endoplasmic reticulum stress and unfolded protein response. A recent study reported that Ufl1, a key enzyme of UFMylation, protects against heart failure, indicating that UFMylation may be associated with heart function regulation. In the present study, we initially constructed a Flag-6×His-tagged Ufm1ΔSC transgenic (Tg-Ufm1) mouse model that enables UFMylation studies in vivo. Tg-Ufm1 mice showed significant activation of UFMylation in hearts. By using this model, we identified 38 potential Ufm1-binding proteins in heart tissues through LC‒MS/MS methods. We found that these proteins were associated with mitochondria, metabolism and chaperone binding. By using transcriptomic screening, we identified Tnfaip2 as a novel UFMylation-associated gene. Overexpression of Ufm1 significantly upregulated the protein expression of Tnfaip2, whereas isoproterenol treatment decreased Tnfaip2 expression in Tg-Ufm1 mice. These data may provide novel clues for UFMylation in cardiac hypertrophy.

Pan-cancer analysis of oncogenic TNFAIP2 identifying its prognostic value and immunological function in acute myeloid leukemia.

BACKGROUND: Tumor necrosis factor alpha-induced protein 2 (TNFAIP2), a TNFα-inducible gene, appears to participate in inflammation, immune response, hematopoiesis, and carcinogenesis. However, the potential role of TNFAIP2 in the development of acute myeloid leukemia (AML) remains unknow yet. Therefore, we aimed to study the biological role of TNFAIP2 in leukemogenesis. METHODS: TNFAIP2 mRNA level, prognostic value, co-expressed genes, differentially expressed genes, DNA methylation, and functional enrichment analysis in AML patients were explored via multiple public databases, including UALCAN, GTEx portal, Timer 2.0, LinkedOmics, SMART, MethSurv, Metascape, GSEA and String databases. Data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and Beat AML database were used to determine the associations between TNFAIP2 expression and various clinical or genetic parameters of AML patients. Moreover, the biological functions of TNFAIP2 in AML were investigated through in vitro experiments. RESULTS: By large-scale data mining, our study indicated that TNFAIP2 was differentially expressed across different normal and tumor tissues. TNFAIP2 expression was significantly increased in AML, particularly in French-American-British (FAB) classification M4/M5 patients, compared with corresponding control tissues. Overexpression of TNFAIP2 was an independent poor prognostic factor of overall survival (OS) and was associated with unfavorable cytogenetic risk and gene mutations in AML patients. DNA hypermethylation of TNFAIP2 at gene body linked to upregulation of TNFAIP2 and inferior OS in AML. Functional enrichment analysis indicated immunomodulation function and inflammation response of TNFAIP2 in leukemogenesis. Finally, the suppression of TNFAIP resulted in inhibition of proliferation by altering cell-cycle progression and increase of cell death by promoting early and late apoptosis in THP-1 and U937AML cells. CONCLUSION: Collectively, the oncogenic TNFAIP2 can function as a novel biomarker and prognostic factor in AML patients. The immunoregulation function of TNFAIP2 warrants further validation in AML.

Genetic polymorphisms of PGF and TNFAIP2 genes related to cervical cancer risk among Uygur females from China.

BACKGROUND: PGF and TNFAIP2 are important angiogenic factors, which were abnormal expression in cervical cancer (CC). However, there is currently no report investigating the relationship of PGF and TNFAIP2 gene polymorphisms to CC risk. METHODS: We conducted a case-control study of 342 CC patients and 498 cancer-free controls in a Chinese Uygur female population. Three SNPs (PGF rs8019391, PGF rs2268615, and TNFAIP2 rs710100) were selected and genotyped to assess the possible association of PGF and TNFAIP2 polymorphisms with CC susceptibility. Logistic regression analysis adjusted by age was used. RESULTS: PGF rs2268615 (OR = 1.39, 95% CI = 1.04-1.86, p = 0.024) and TNFAIP2 rs710100 (OR = 1.44, 95% CI =1.07-1.95, p = 0.018) polymorphisms were associated with the increased risk of CC. Moreover, T allele of PGF rs8019391 was highly represented in patients with stage III-IV compared with stage I-II (OR = 2.17, p = 4.58 × 10- 4). MDR analysis revealed a positive interaction between the SNPs. CONCLUSION: Our data indicated that PGF rs2268615, and TNFAIP2 rs710100 polymorphisms might be risk factors for CC susceptibility, which contributed to the increased risk of CC. TRIAL REGISTRATION: Not applicable.

The roles of TNFAIP2 in cancers and infectious diseases.

TNFα-induced protein 2 (TNFAIP2) is a primary response gene of TNFα. TNFAIP2 is highly expressed in immune cells and the urinary bladder. The expression of TNFAIP2 is regulated by multiple transcription factors and signalling pathways, including NF-κB, KLF5 and retinoic acid. Physiologically, TNFAIP2 appears to be a multiple functional mediator not only for inflammation, angiogenesis and tunneling nanotube (TNT) formation but also as a regulator of cell proliferation and migration. The expression of TNFAIP2 is frequently abnormal in human cancers and in infectious diseases. Due to its significant functions in cell proliferation, angiogenesis, migration and invasion, TNFAIP2 could be a potential diagnostic biomarker and therapeutic target for cancer.

Genome-wide Chromatin Profiling of Legionella pneumophila-Infected Human Macrophages Reveals Activation of the Probacterial Host Factor TNFAIP2.

BACKGROUND: Legionella pneumophila is a causative agent of severe pneumonia. Infection leads to a broad host cell response, as evident, for example, on the transcriptional level. Chromatin modifications, which control gene expression, play a central role in the transcriptional response to L. pneumophila METHODS: We infected human-blood-derived macrophages (BDMs) with L. pneumophila and used chromatin immunoprecipitation followed by sequencing to screen for gene promoters with the activating histone 4 acetylation mark. RESULTS: We found the promoter of tumor necrosis factor α-induced protein 2 (TNFAIP2) to be acetylated at histone H4. This factor has not been characterized in the pathology of L. pneumophila TNFAIP2 messenger RNA and protein were upregulated in response to L. pneumophila infection of human-BDMs and human alveolar epithelial (A549) cells. We showed that L. pneumophila-induced TNFAIP2 expression is dependent on the NF-κB transcription factor. Importantly, knock down of TNFAIP2 led to reduced intracellular replication of L. pneumophila Corby in A549 cells. CONCLUSIONS: Taken together, genome-wide chromatin analysis of L. pneumophila-infected macrophages demonstrated induction of TNFAIP2, a NF-κB-dependent factor relevant for bacterial replication.

The miR-146b-3p/TNFAIP2 axis regulates cell differentiation in acute myeloid leukaemia.

Our purpose is to verify that miR-146b-3p targets the downstream transcript TNFAIP2 in order to reveal the machinery underlying the miR-146b-3p/TNFAIP2 axis regulating acute myeloid leukaemia (AML) differentiation. Bioinformatics analyses were performed using multiple databases and R packages. The CD11b+ and CD14+ cell frequencies were detected using flow cytometry and immunofluorescence staining. The TNFAIP2 protein expression was evaluated using western blotting, immunocytochemistry and immunofluorescence staining. The qRT-PCR was conducted to detect the expression of TNFAIP2 and miR-146b-3p. TNFAIP2 and its correlated genes were enriched in multiple cell differentiation pathways. TNFAIP2 was upregulated upon leukaemic cell differentiation. miR-146b-3p directly targeted TNFAIP2, resulting in a decrease in TNFAIP2 expression. Forced expression of TNFAIP2 or knockdown of miR-146b-3p significantly induced the differentiation of MOLM-13 cells. In this study, we demonstrated that TNFAIP2 is a critical driver in inducing differentiation and that the miR-146b-3p/TNFAIP2 axis involves in regulating cell differentiation in AML.

TNFAIP2 confers cisplatin resistance in head and neck squamous cell carcinoma via KEAP1/NRF2 signaling.

BACKGROUND: Drug resistance limits the treatment effect of cisplatin-based chemotherapy in head and neck squamous cell carcinoma (HNSCC), and the underlying mechanism is not fully understood. The aim of this study was to explore the cause of cisplatin resistance in HNSCC. METHODS: We performed survival and gene set variation analyses based on HNSCC cohorts and identified the critical role of tumor necrosis factor alpha-induced protein 2 (TNFAIP2) in cisplatin-based chemotherapy resistance. Half-maximal inhibitory concentration (IC50) examination, colony formation assays and flow cytometry assays were conducted to examine the role of TNFAIP2 in vitro, while xenograft models in nude mice and 4-nitroquinoline N-oxide (4NQO)-induced HNSCC models in C57BL/6 mice were adopted to verify the effect of TNFAIP2 in vivo. Gene set enrichment analysis (GSEA) and coimmunoprecipitation coupled with mass spectrometry (Co-IP/MS) were performed to determine the mechanism by which TNFAIP2 promotes cisplatin resistance. RESULTS: High expression of TNFAIP2 is associated with a poor prognosis, cisplatin resistance, and low reactive oxygen species (ROS) levels in HNSCC. Specifically, it protects cancer cells from cisplatin-induced apoptosis by inhibiting ROS-mediated c-JUN N-terminal kinase (JNK) phosphorylation. Mechanistically, the DLG motif contained in TNFAIP2 competes with nuclear factor-erythroid 2-related factor 2 (NRF2) by directly binding to the Kelch domain of Kelch-like ECH-associated protein 1 (KEAP1), which prevents NRF2 from undergoing ubiquitin proteasome-mediated degradation. This results in the accumulation of NRF2 and confers cisplatin resistance. Positive correlations between TNFAIP2 protein levels and NRF2 as well as its downstream target genes were validated in HNSCC specimens. Moreover, the small interfering RNA (siRNA) targeting TNFAIP2 significantly enhanced the cisplatin treatment effect in a 4NQO-induced HNSCC mouse model. CONCLUSIONS: Our results reveal the antioxidant and cisplatin resistance-regulating roles of the TNFAIP2/KEAP1/NRF2/JNK axis in HNSCC, suggesting that TNFAIP2 might be a potential target in improving the cisplatin treatment effect, particularly for patients with cisplatin resistance.

Integrin ß4 promotes DNA damage-related drug resistance in triple-negative breast cancer via TNFAIP2/IQGAP1/RAC1.

Anti-tumor drug resistance is a challenge for human triple-negative breast cancer (TNBC) treatment. Our previous work demonstrated that TNFAIP2 activates RAC1 to promote TNBC cell proliferation and migration. However, the mechanism by which TNFAIP2 activates RAC1 is unknown. In this study, we found that TNFAIP2 interacts with IQGAP1 and Integrin ß4. Integrin ß4 activates RAC1 through TNFAIP2 and IQGAP1 and confers DNA damage-related drug resistance in TNBC. These results indicate that the Integrin ß4/TNFAIP2/IQGAP1/RAC1 axis provides potential therapeutic targets to overcome DNA damage-related drug resistance in TNBC.

Tnfaip2 promotes atherogenesis by enhancing oxidative stress induced inflammation.

The inflammation is considered to be the crucial determinants of lesion progression and plaque stability during atherogenesis. Tnfaip2 appears to be a regulator for carcinogenesis and infectious diseases. But its role in atherosclerosis is not clear. Here we first report that Tnfaip2 promotes the formation of atherosclerosis through enhancing the inflammation under oxidative stress condition. Although the endogenous expression of Tnfaip2 was upregulated under oxidative stress condition, the overexpressed Tnfaip2 could promote cells proliferation. This might result from the ability of promoting cells entering G2/M phase. Conversely, the cells proliferation and migration were significantly reduced in Tnfaip2 knockdown cells through inhibiting the activation of NF-κB/MAPK/Akt signaling pathways. However, the efferocytosis increased markedly due to the upregulation of "eat me" receptors, such as CD36, SR-A, and SR-B1, and the downregulation of "don't eat me" signal CD47. As a consequence, Tnfaip2 deficiency in bone marrow-derived cells inhibited atherosclerosis development in Ldlr-/- mice fed a high-fat diet accompanied by decreased inflammatory cytokines and shTnfaip2 could reduce the plaque lesions in ApoE-/- mice. These results indicate that Tnfaip2 might play an important role during atherogenesis.

Susceptibility of TNFAIP8, TNFAIP8L1, and TNFAIP2 Gene Polymorphisms on Cancer Risk: A Comprehensive Review and Meta-Analysis of Case-Control Studies.

Objectives: The TNFAIP8 gene family and TNFAIP2 gene are inextricably linked to an elevated risk of cancer development. This systemic review and meta-analysis seeks to establish the relationship between TNFAIP8 (rs11064, rs1045241, rs1045242, and rs3813308), TNFAIP8L1 (rs1060555), and TNFAIP2 (rs710100 and rs8126) polymorphisms with the risk of cancer. Methods and Materials: A systematic search of multiple databases from January 2022 to April 2022 was used to identify relevant studies. Odds ratios (ORs) with corresponding 95% CI and p-value were calculated to assess the association. Bonferroni correction was performed to correct p-values. Trial sequential analysis (TSA) and in-silico messenger RNA expression were also performed. Review Manager 5.4 software was used for performing this meta-analysis. Results: This study comprised 6909 cancer patients and 7087 healthy participants from 14 studies. Four genetic models of rs11064 (codominant 2 [COD2]: OR = 2.30, p = 7.83 × 10-5; codominant 3 [COD3]: OR = 2.10, p = .0006; recessive model [RM]: OR = 2.24, p = .0001; AC: OR = 1.47, p = .037), two genetic models of rs1045241 (codominant 1 [COD1]: OR = 1.27, p = .009; overdominant model [ODM]: OR = 1.24, p = .018), four genetic models of rs1045242 (COD1: OR = 1.52, p = .005; dominant model (DM): OR = 1.56, p = .002; OD: OR = 1.48, p = .008; AC: OR = 1.48, p = .002), and three genetic models of rs8126 (COD2: OR = 1.41, p = .0005; COD3: OR = 1.44, p = .0002; RM: OR = 1.43, p = .0001) were statistically linked to cancer risk. Only one genetic model of rs1060555 polymorphism showed a significant protective association with cancer (COD2: OR = 0.80, p = .048). The outcomes of TSA also validated the findings of the meta-analysis. Conclusion: This study summarizes that rs11064, rs1045241, and rs1045242 polymorphisms of TNFAIP8 gene and rs8126 polymorphism of TNFAIP2 gene are significantly linked with the risk of cancer development. This meta-analysis was registered at INPLASY (registration number: INPLASY202270073).

Correlation Between TNFAIP2 Gene Polymorphism and Prediction/Prognosis for Gastric Cancer and Its Effect on TNFAIP2 Protein Expression.

Objective: TNFAIP2 is a novel gene induced by TNF-α and participates in inflammatory reaction and tumor angiogenesis. This study aims to understand the correlation between TNFAIP2 gene polymorphism and prediction as well as prognosis of gastric cancer (GC) in a Chinese population. Methods: One thousand two hundred seventy-nine cases were enrolled, including 640 GC and 639 non-cancer cases. The functional tagSNPs of the TNFAIP2 gene were screened by Haploview software and NIH Snpinfo website. Human whole-blood genomic DNA was extracted by phenol chloroform method and analyzed by KASP SNP typing and sequencing method. ELISA was used to determine the expression of TNFAIP2 protein in serum samples. The miRNAs bound to TNFAIP2 3' UTR rs8126 were predicted by MirSNP and TargetScan database. SPSS 22.0 software was used for statistical analysis, and P < 0.05 showed statistical difference. Results: Four functional TNFAIP2 tagSNPs were found by bioinformatics analysis. TNFAIP2 rs8126 T>C polymorphism increased GC risk, and the risk in TC genotype cases was higher than that in TT genotype cases (P = 0.001, OR = 1.557). In the dominant model, the TNFAIP2 rs8126 polymorphic carrier was 1.419 times higher (P = 0.007). TNFAIP2 rs710100 C>T polymorphism, TNFAIP2 rs3759571 G>A polymorphism, and TNFAIP2 rs3759573 A>G polymorphism were not correlated with GC risk. In the subgroup analysis, TNFAIP2 rs8126 TC genotype cases had a higher GC risk in male, aged 60 years or older, Helicobacter pylori-negative, non-smoking, and non-drinking. However, there was no correlation between TNFAIP2 SNPs and GC prognosis. The TNFAIP2 protein concentration in GC patients was significantly different from that in healthy persons (P = 0.029), but it was not associated with GC prognosis. The high or low expression of TNFAIP2 protein had no significant difference with gender, age, H. pylori infection, smoking, and drinking in GC patients. The serum TNFAIP2 protein expression in rs8126 TT genotype carriers was significantly higher than that in rs8126 CC genotype carriers (P < 0.001). Conclusion: TNFAIP2 3' UTR rs8126 T>C polymorphism was associated with GC risk in a Chinese population, especially in cases with males aged 60 years or older, H. pylori negative, non-smoking and non-drinking. Compared with healthy persons, serum TNFAIP2 protein expression was higher in Chinese GC patients, and TNFAIP2 3' UTR rs8126 T>C polymorphism might affect TNFAIP2 protein expression.

TNFAIP2 Promotes Non-Small Cell Lung Cancer Cells and Targeted by miR-145-5p.

Tumor necrosis factor-alpha (TNFα) is an inflammatory cytokine that regulates inflammation and tumor progression in non-small cell lung cancer (NSCLC). The higher levels of TNF α are known to induce expression of several genes such as TNFα-induced protein 2 (TNFAIP2) with a largely unknown role in NSCLC. We provide the preliminary evidence for the role of TNFAIP2 in NSCLC progression and its epigenetic regulation mediated by microRNA, miR-145-5p. The expression of TNFAIP2 was confirmed using quantitative real-time PCR, immunohistochemistry, and Western blot in NSCLC tissue and paired adjacent normal tissue. All in vitro assays were undertaken in A549 and H23 cells and chemoresistance assays were undertaken in A549/Cisplatin (DDP) and H23/DDP cell types. TNFAIP2 silencing was undertaken using lipofectamine transfection of specific siRNA. Cells were co-transfected with miR-145-5p, and TNFAIP2-3' untranslated region (UTR) or TNFAIP2 with mutated 3'UTR using the luciferase vector pGL. Cell viability, transwell migration, and invasion were assessed. The role of caspase 3 proteins in cell viability was ascertained using Western blot. The tumor tissues (and cisplatin-resistant cell lines A549/DDP and H23/DDP) expressed significantly higher levels of TNAIP2 mRNA and protein. Silencing of TNFAIP2 resulted in reduced cell viability, reduced invasion, and migration in vitro. Silencing of TNFAIP2 in A549/DDP and H23/DDP had higher expression of TNFAIP2, reduced cell viability, and increased induction of caspase 3. MiR-145-5p binds to the 3'UTR of TNFAIP2. Overexpression of MiR-145-5p reduced expression of TNFAIP2, decreased cell viability, reduced cell migration and invasion, and significantly reduced expression of caspase 3 protein. TNFAIP2 mediates tumorigenesis in NSCLC through, not completely known pathways. miR-145-5p negatively regulates TNFAIP2 expression. miR-145-5p-mediated therapies may be explored in NSCLC.

Amentoflavone protects the hematopoietic system of mice against γ-irradiation.

Some flavonoids have been shown to exhibit good antioxidant activity and protect mice from damage induced by radiation. Amentoflavone (AMF), a biflavonoid derived from the traditional herb-Selaginella tamariscina, has been reported to have antioxidant properties. The protective effects and mechanism of action of AMF against radiation injury remain unknown. In this study, male C57BL/6 mice were subjected to total-body 60Co γ-irradiation at 7.5 or 3.0 Gy. The survival rate and mean survival time were evaluated to determine the radioprotective effect of AMF. Number of peripheral blood cells, frequency of colony forming unit-granulocytes, monocytes and micronuclei were measured to assess the protective effects of AMF on the hematopoietic system. Levels of superoxide dismutase and glutathione, and pathological changes in the bone marrow were determined. Additionally, next-generation sequencing technology was used to explore potential targets of AMF. We observed that AMF markedly extends average survival time, reduces injury to the hematopoietic system and promotes its recovery. Furthermore, treatment with AMF significantly attenuated radiation-induced oxidative stress. In addition, AMF had a significant effect on gene tumor necrosis factor alpha-induced protein 2. Together, the results of this study suggest that AMF is a potential protective agent against radiation injury.