TIPE2 Suppresses Malignancy of Pancreatic Cancer Through Inhibiting TGFβ1 Mediated Signaling Pathway

The combination of microwave hyperthermia with TIPE2 impedes the growth of orthotopic colon cancer

BACKGROUND

Colon cancer (CC) is the main fatal disease of humans. Microwave hyperthermia (MH) is an adjuvant therapy for diverse cancers. Tumor necrosis factor-α induced protein-8-like 2 (TIPE2) is a tumor suppressor. However, the effect of MH combined with TIPE2 on CC remains unclear.

METHODS

The orthotopic CC mouse model was constructed by mouse CC CT26-Luc cells, and mice were randomized into control, model (CT26-Luc), CT26-Luc + Vector, CT26-Luc + TIPE2, CT26-Luc + MH, and CT26-Luc + MH+TIPE2 groups (n = 6). Tumor growth pretreatment and post-treatment by in vivo fluorescence image analysis was detected. TIPE2 expression and cell transfection efficiency was detected by qRT-PCR and western blot. The pathological changes by HE staining, apoptosis by TUNEL staining, serum inflammatory factors by ELISA, TIPE2 expression by immunohistochemistry, and NF-κB signaling by western blot was performed.

RESULTS

Paracancerous tissues showed higher TIPE2 expression than in CC tissues. CT26-Luc + TIPE2, CT26-Luc + MH, and CT26-Luc + MH+TIPE2 groups reduced tumor growth, tumor cell infiltration, and increased apoptosis. CT26-Luc + TIPE2 group had lower NF-κB, TNF-α, IL-1β, IL-6, p-p65, and p-IKK expression, and elevated TIPE2 and IkB expression, which was reversed by CT26-Luc + MH group. Moreover, CT26-Luc+MH+TIPE2 group showed opposite effects on the above factor expression of CT26-Luc+MH group.

CONCLUSIONS

Combination of MH with TIPE2 could impede CC tumor growth, providing scientific bases for its clinical application in CC treatment.

TIPE2 inhibits melanoma progression through MEK/ERK signaling

Recent studies have uncovered that TIPE2 is involved in the development of cancer. However, less research has been conducted on the role of TIPE2 in melanoma. Our study aims to elucidate the mechanism of action of TIPE2 in the development of melanoma. We examined TIPE2 expression in paracarcinoma tissue and melanoma tissues and found that TIPE2 expression was downregulated in melanoma tissue compared with paracarcinoma tissue. Overexpression of TIPE2 significantly inhibited the proliferation of melanoma cells in vitro and even inhibited tumor formation in vivo. The CCK8 assay results indicated that TIPE2 overexpression suppressed the proliferation of melanoma cells. The colony-forming ability and wound healing ability of TIPE2-overexpressing melanoma cells were significantly reduced compared with those of control cells. Moreover, immunohistochemistry experiments using a nude mouse tumor model showed consistent results. TIPE2 inhibited the phosphorylation of MEK and ERK. In summary, TIPE2 suppresses the proliferation and migration of melanoma cells by affecting proliferation-related factors and possibly by regulating the MEK/ERK pathway. TIPE2 could be used to inhibit melanoma growth and is a potential drug target for future drug development.

TIPE2 inhibits the migration and invasion of epithelial ovarian cancer cells by targeting Smad2 to reverse TGF-β1-induced EMT

Epithelial ovarian cancer is the deadliest gynecologic malignancy, characterized by high metastasis. Transforming growth factor-β1 (TGF-β1) drives epithelial- mesenchymal transformation (EMT), a key process in tumor metastasis. Tumor necrosis factor-α-induced protein 8 (TNFAIP8)-like 2 (TIPE2) acts as a negative regulator of innate and adaptive immunity and involves in various cancers. However, its relationship with TGF-β1 in ovarian cancer and its role in reversing TGF-β1-induced EMT remain unclear. This study examined TIPE2 mRNA and protein expression using quantitative RT-PCR (qRT-PCR), western blot and immunohistochemistry. The effects of TIPE2 overexpression and knockdown on the proliferation, migration and invasion of epithelial ovarian cancer cells were assessed through 5-ethynyl-2-deoxyuridine, colony-forming, transwell migration and invasion assays. The relationship between TIPE2 and TGF-β1 was investigated using qRT-PCR and enzyme-linked immunosorbent assay, while the interaction between TIPE2 and Smad2 was identified via co-immunoprecipitation. The results revealed that TIPE2 protein was significantly down-regulated in epithelial ovarian cancer tissues and correlated with the pathological type of tumor, patients' age, tumor differentiation degree and FIGO stage. TIPE2 and TGF-β1 appeared to play an opposite role to each other during the progression of human ovarian cancer cells. Furthermore, TIPE2 inhibited the metastasis and EMT of ovarian cancer cells by combining with Smad2 in vitro or in an intraperitoneal metastasis model. Consequently, these findings suggest that TIPE2 plays a crucial inhibitory role in ovarian cancer metastasis by modulating the TGF-β1/Smad2/EMT signaling pathway and may serve as a potential target for ovarian cancer, providing important direction for future diagnostic and therapeutic strategies.

TIPE2: A Candidate for Targeting Antitumor Immunotherapy

TNF-α-induced protein 8-like 2 (TIPE2 or TNFAIP8L2) is a recently discovered negative regulator of innate and adaptive immunity. TIPE2 is expressed in a wide range of tissues, both immune and nonimmune, and is implicated in the maintenance of immune homeostasis within the immune system. Furthermore, TIPE2 has been shown to play a pivotal role in the regulation of inflammation and the development of tumor. This review focuses on the structural characteristics, expression patterns, and functional roles of TIPE proteins, with a particular emphasis on the role and underlying mechanisms of TIPE2 in immune regulation and its involvement in different diseases. However, the current body of evidence is still limited in providing a comprehensive understanding of the complex role of TIPE2 in the human body, warranting further investigation to elucidate the possible mechanisms and functions of TIPE2 in diverse disease contexts.

Hepatocyte TIPE2 is a fasting-induced Raf-1 inactivator that drives hepatic gluconeogenesis to maintain glucose homeostasis

BACKGROUND

The liver regulates metabolic balance during fasting-feeding cycle. Hepatic adaptation to fasting is precisely modulated on multiple levels. Tumor necrosis factor-α-induced protein 8-like 2 (TIPE2) is a negative regulator of immunity that reduces several liver pathologies, but its physiological roles in hepatic metabolism are largely unknown.

METHODS

TIPE2 expression was examined in mouse liver during fasting-feeding cycle. TIPE2-knockout mice, liver-specific TIPE2-knockout mice, liver-specific TIPE2-overexpressed mice were examined for fasting blood glucose and pyruvate tolerance test. Primary hepatocytes or liver tissues from these mice were evaluated for glucose production, lipid accumulation, gene expression and regulatory pathways. TIPE2 interaction with Raf-1 and TIPE2 transcription regulated by PPAR-α were examined using gene overexpression or knockdown, co-immunoprecipitation, western blot, luciferase reporter assay and DNA-protein binding assay.

RESULTS

TIPE2 expression was upregulated in fasted mouse liver and starved hepatocytes, which was positively correlated with gluconeogenic genes. Liver-specific TIPE2 deficiency impaired blood glucose homeostasis and gluconeogenic capacity in mice upon fasting, while liver-specific TIPE2 overexpression elevated fasting blood glucose and hepatic gluconeogenesis in mice. In primary hepatocytes upon starvation, TIPE2 interacted with Raf-1 to accelerate its ubiquitination and degradation, resulting in ERK deactivation and FOXO1 maintenance to sustain gluconeogenesis. During prolonged fasting, hepatic TIPE2 deficiency caused aberrant activation of ERK-mTORC1 axis that increased hepatic lipid accumulation via lipogenesis. In hepatocytes upon starvation, PPAR-α bound with TIPE2 promoter and triggered its transcriptional expression.

CONCLUSIONS

Hepatocyte TIPE2 is a PPAR-α-induced Raf-1 inactivator that sustains hepatic gluconeogenesis and prevents excessive hepatic lipid accumulation, playing beneficial roles in hepatocyte adaptation to fasting.

TIPE2 sensitizes breast cancer cells to paclitaxel by suppressing drug-induced autophagy and cancer stem cell properties

Drug resistance is a great obstacle to the clinical application of paclitaxel (PTX) in breast cancer treatment. Chemoresistance can be either primary or acquired. Multifarious factors are related to drug resistance. Among these factors, drug-induced autophagy has been shown to contribute to acquired chemoresistance in cancer cells. Additionally, cancer stem cells (CSCs) drive primary chemoresistance. Recent advances regarding TIPE2 demonstrate that TIPE2 enhances osteosarcoma and non-small cell lung cancer cell sensitivity to cisplatin. However, the role of TIPE2 in PTX resistance in breast cancer cells has not been elucidated. Here, the in vitro and in vivo study demonstrated that TIPE2 sensitized breast cancer cells to PTX by suppressing drug-induced autophagy and CSC properties. Mechanistically, we found that TIPE2 activated the AKT/mTOR signalling pathway and inhibited the TAK1/MAPK signalling pathway to suppress drug-induced autophagy. Moreover, TIPE2 inhibited TAK1/NF-κB activation to reduce breast CSC properties. Collectively, our results first elucidated the inhibitory role of TIPE2 in breast cancer chemoresistance. Thus, TIPE2 may be a new target for breast cancer chemotherapy.

TIPE2 acts as a tumor suppressor and correlates with tumor microenvironment immunity in epithelial ovarian cancer

BACKGROUND

Epithelial ovarian cancer (EOC) is one of the deadliest gynecologic cancers. The etiology of EOC has still not been elucidated thoroughly. Tumor necrosis factor-α-induced protein 8-like2 (TNFAIP8L2, TIPE2), an important regulator of inflammation and immune homeostasis, plays a critical role in the progression of various cancers. This study aims to investigate the role of TIPE2 in EOC.

METHODS

Expression of TIPE2 protein and mRNA in EOC tissues and cell lines was examined using Western blot and quantitative real-time PCR (qRT-PCR). The functions of TIPE2 in EOC were investigated by cell proliferation assay, colony assay, transwell assay, and apoptosis analysis in vitro. To further investigate the regulatory mechanisms of TIPE2 in EOC, RNA-seq and western blot were performed. Finally, the CIBERSORT algorithm and databases including Tumor Immune Single-cell Hub (TISCH), Tumor Immune Estimation Resource (TIMER), Tumor-Immune System Interaction (TISIDB), and The Gene Expression Profiling Interactive Analysis (GEPIA) were used to elucidate its potential role in regulating tumor immune infiltration in the tumor microenvironment (TME).

RESULTS

TIPE2 expression was shown to be considerably lower in both EOC samples and cell lines. Overexpression of TIPE2 suppressed EOC cell proliferation, colony formation, and motility in vitro. Mechanistically, TIPE2 suppressed EOC by blocking the PI3K/Akt signaling pathway, according to bioinformatics analysis and western blot in TIPE2 overexpression EOC cell lines, and the anti-oncogenic potentials of TIPE2 in EOC cells could be partially abrogated by the PI3K agonist, 740Y-P. Finally, TIPE2 expression was positively associated with various immune cells and possibly involved in the regulation of macrophage polarization in ovarian cancer.

CONCLUSIONS

We detail the regulatory mechanism of TIPE2 in EOC carcinogenesis, as well as how it correlates with immune infiltration, emphasizing its potential as a therapeutic target in ovarian cancer.

TIPE2 Inhibits Migration and Promotes Apoptosis as a Tumor Suppressor in Hypopharyngeal Carcinoma

BACKGROUND

Hypopharyngeal squamous cell carcinoma (HSCC) is a common malignant cancer characterized by high metastasis and infiltration. The development of new approaches for the early diagnosis and identification of new therapeutic targets is essential. TIPE2 is well known as a tumor suppressor and related to a favorable prognosis of HSCC. However, its underlying mechanism remains unclear.

METHODS AND MATERIALS

TIPE2 expression was determined by immunohistochemistry and RT-qPCR. A TIPE2 overexpression stable cell line was generated by lentivirus infection. TIPE2 and other related protein levels were detected by western blotting. The cell cycle and apoptosis were performed by flow cytometric analysis. Cell proliferation was measured with a Cell Counting Kit-8 (CCK-8) assay, and the activity of caspase-3 and caspase-7 was assessed by Caspase-Glo® 3/7 Assay. All data were analyzed with SPSS 25 and GraphPad Prism 8.0.

RESULTS

TIPE2 expression was significantly down-regulated in HSCC. Low TIPE2 expression may be associated with poor prognosis in HSCC. TIPE2 overexpression markedly inhibited tumor cell migration. Moreover, TIPE2 decreased cell proliferation but promoted apoptosis. TIPE2 suppressed tumor growth by activating Epithelial-Mesenchymal Transition (EMT) and the extrinsic apoptosis pathway.

CONCLUSION

TIPE2 inhibited tumor progression by suppressing cell migration but promoting apoptosis. TIPE2 can be a new therapeutic target in HSCC.