Knockdown of TIPE2 increases the proliferation in lipopolysaccharide-stimulated gastric cancer cells

Research progress of TIPE2 in immune-related diseases

The tumor necrosis factor α-induced protein 8 (TNFAIP8) family, which consists of TNFAIP8 (TIPE), TNFAIP8L1 (TIPE1), TNFAIP8L2 (TIPE2) and TNFAIP8L3 (TIPE3), has recently emerged as a regulatory factor involved in immune response and tumorigenesis. Among its members, TIPE2 acts as a negative regulator of both innate and adaptive immunity, playing a crucial role in maintaining immune homeostasis by negatively regulating T cell receptor (TCR) and toll-like receptor (TLR) signal transduction. Immune homeostasis is an indispensable characteristic of the immune system, which prevents harmful inflammatory reactions and ensures the proper functioning of the body. A large number of studies have shown that abnormal TIPE2 expression exists in a variety of inflammation-related diseases such as asthma, colitis, and systemic lupus erythematosus, highlighting the importance of comprehending its function for the prevention and treatment of immune-related conditions. This review aims to provide an overview of the in vivo distribution and expression of TIPE2, its regulatory role in central and peripheral immune-related diseases, and the underlying mechanisms that govern its function in the inflammatory response. By delving into these aspects, a deeper understanding of the role and functionality of TIPE2 in inflammatory responses can be achieved.

Beneficial Effects of Gracillin From Rhizoma Paridis Against Gastric Carcinoma via the Potential TIPE2-Mediated Induction of Endogenous Apoptosis and Inhibition of Migration in BGC823 Cells

Tumor necrosis factor-α inducible protein-8 (TIPE2), initially recognized as a negative immune regulator, exerts an important role in suppressing the progression of numerous cancers. In our previous investigation, we found that TIPE2 expression displayed a decrease or absence in gastric tumor tissue, and the overexpression of TIPE2 suppressed the growth of gastric cancer tumors and cells, demonstrating that TIPE2 could be a potential medicinal target for gastric cancer treatment. However, it’s seldomly reported that several medicinal agents or candidates targeted TIPE2 for treating diseases, including gastric cancer. To identify the candidate targeting TIPE2 to fight against gastric cancer, several extractions from traditional natural medicinal plants with anti-tumor functions were employed to screen the active compounds according to bioassay-guided isolation. Interestingly, gracillin, a component from the ethyl acetate extraction of Rhizoma Paridis, was identified to induce the expression of TIPE2 and inhibit the cell proliferation in gastric cancer BGC-823 cells. Furthermore, the underlying mechanisms that restrain gastric cancer were evaluated by clone formation, EdU staining, flow cytometry, and other assays. Meanwhile, the role of TIPE2 in the anti-tumor effect of gracillin was elucidated via the use of siTIPE2 RNA. It was determined that gracillin could fight against gastric cancer cells by inhibiting the cell proliferation participated by the PI3K/AKT pathway and cell cycle arrest, suppressing the EMT pathway-regulating cell migration, and inducing bcl2-associated mitochondrial apoptosis. Additionally, TIPE2 maybe contribute to the benefits of gracillin. These results of the present study are an important step toward the medicinal development of gracillin, and are also of use in understanding the effect of TIPE2 as a potential tumor target.

TIPE2 inhibits the migration and invasion of endometrial cells by targeting β-catenin to reverse epithelial-mesenchymal transition

STUDY QUESTION

Do changes in tumor necrosis factor-α-induced protein 8 (TNFAIP8)-like 2 (TIPE2) levels in endometrium of patients with adenomyosis alter the proliferation, migration and invasion ability of endometrial cells?

SUMMARY ANSWER

TIPE2 expression levels were low in eutopic and ectopic endometrium of adenomyosis patients, and TIPE2 inhibited the migration and invasion of endometrial cells, mainly by targeting β-catenin, to reverse the epithelial-mesenchymal transition (EMT).

WHAT IS KNOWN ALREADY

Adenomyosis is a benign disease, but it has some pathophysiological characteristics similar to the malignant tumor. TIPE2 is a novel negative immune regulatory molecule, and it also participates in the development of malignant tumors.

STUDY DESIGN, SIZE, DURATION

Control endometrium (n = 48 women with non-endometrial diseases) and eutopic/ectopic endometrium from patients with adenomyosis (n = 50), human endometrial cancer cell lines, and primary endometrial cells from the eutopic endometrium of adenomyosis patients were used in the study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The expression level of TIPE2 mRNA and protein in the eutopic/ectopic endometrial tissues of adenomyosis patients and control endometrium was determined by quantitative RT-PCR (qRT-PCR), western blot and immunohistochemistry. The effects of TIPE2 overexpression and knockdown on the proliferation, migration and invasion of endometrial cell lines and primary adenomyotic endometrial cells were determined using a cell counting kit-8, 5-ethynyl-2'-deoxyuridine assay, colony-forming assay, transwell migration assay and matrigel invasion assay. The expression of EMT-related markers and signal molecules was detected by western blot. The interaction between TIPE2 and β-catenin was detected by co-immunoprecipitation and laser confocal microscopy.

MAIN RESULTS AND THE ROLE OF CHANCE

The mRNA and protein expression levels of TIPE2 in the eutopic and ectopic endometrial tissues of adenomyosis patients were significantly downregulated compared with the control endometrium (P ˂ 0.01). TIPE2 could bind to β-catenin and inhibit the nuclear translocation of β-catenin, downregulate the expression of stromal cell markers, upregulate the expression of glandular epithelial cell markers, decrease the occurrence of epithelial-mesenchymal transition (EMT) and suppress the migration and invasion of endometrial cells (P ˂ 0.01).

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

In this study, the experiments were performed only in eutopic and ectopic endometrial tissues, endometrial cancer cell lines and primary adenomyotic endometrial cells. A mouse model of adenomyosis will be constructed to detect the effects of TIPE2 in vivo.

WIDER IMPLICATIONS OF THE FINDINGS

These results suggest that TIPE2 is involved in the development of adenomyosis, which provides a potential new diagnostic and therapeutic strategy for the treatment of adenomyosis.

STUDY FUNDINGS/COMPETING INTEREST(S)

This present study was supported by grants from the National Natural Science Foundation of China (81471437, 81771554), Natural Science Foundation of Shandong (ZR2018MH013), Science and technology development plan provided by Health and Family Planning Committee in Shandong (2014-25). The authors declare that they have no conflicts of interest.

TIPE2 suppresses progression and tumorigenesis of the oral tongue squamous cell carcinoma by regulating FoxP3+ regulatory T cells

To discover the effect of tumor necrosis factor-alpha-induced protein 8-like 2 (TIPE2) on the oral tongue squamous cell carcinoma (OTSCC) via affecting FoxP3⁺ regulatory T (Treg) cells. Immunohistochemistry was conducted to examine TIPE2 and FoxP3 expressions in OTSCC tumor tissues and corresponding oral mucosa. Tca8113 cells were transfected with TIPE2/control lentiviral activation particles followed by the detection with qRT-PCR, Western blotting, MTT assay, Wound healing, Transwell assay and Annexin V-FITC/PI staining. In vivo experiment was carried out on the nude mice xenografts of OTSCC with TIPE2 overexpression to observe the tumor volume and survival, and the CD4⁺ T cell subgroups were detected by flow cytometry. TIPE2 was lower in the OTSCC tissues than the corresponding oral mucosa, which was correlated with T stage, N stage, TNM stage, and differentiation of patients. Patients with TIPE2-positive expression had worse prognosis and lower expression of FoxP3⁺ Treg cells than the negative ones. Furthermore, TIPE2 overexpression curbed proliferation, invasion and migration of Tca8113 cells, while cell apoptosis was increased. Besides, TIPE2 suppressed the tumor growth and extended the survival of OTSCC mice, with the decreased proportion of FoxP3⁺ Treg cells in the spleen and tumor-infiltrated lymphocytes (TILs). The clinical results showed the down-regulation of TIPE2 in OTSCC tissues. Meanwhile TIPE2 overexpression affected OTSCC cells biological behavior in vitro, as well as exhibited strong tumor-growth suppressive effects in vivo, which may be a potential therapeutic target in OTSCC via regulating FoxP3⁺ Treg cells.