Hepatitis C virus promotes hepatocellular carcinogenesis by targeting TIPE2, a new regulator of DNA damage response

Expression of TIPE family members in human colorectal cancer

The tumor necrosis factor α-induced protein 8 (TNFAIP8)-like (TIPE) protein family comprises four members, namely TNFAIP8, TIPE1, TIPE2 and TIPE3, which are involved in multiple processes in cancer. The current study aimed to investigate the expression patterns and potential clinical roles of the TIPE family members in human colorectal cancer (CRC). Paired tumor and adjacent tissue samples were collected from 49 patients with CRC, and the relative mRNA expression levels of the TIPE family members in these samples were evaluated by using reverse transcription-quantitative PCR, and the protein levels in five randomly selected pairs of tumor and adjacent tissue samples were detected by western blot analysis. The mRNA expression levels of the TIPE family members were significantly downregulated in CRC tumor tissues compared with those in the adjacent tissues; however, within each sample, TNFAIP8 and TIPE3 protein levels were only partially consistent with their mRNA levels. In addition, the mRNA expression levels between each pair of TIPE family members exhibited a positive linear relationship, and TIPE2 mRNA levels exhibited strong linear associations with those of TNFAIP8 and TIPE1. TNFAIP8 mRNA expression levels in tumor tissues were significantly associated with the tumor differentiation grade, and TIPE2 mRNA expression levels in tumor tissues were significantly associated with sex. TIPE1 and TIPE3 mRNA expression levels in tumor tissues exhibited no associations with patient clinicopathological characteristics. In addition, the mRNA expression patterns of the TIPE family members were analyzed using data from The Cancer Genome Atlas data set, and the results also demonstrated that TNFAIP8, TIPE2 and TIPE3 mRNA levels were downregulated in patients with colon adenocarcinoma compared with those in normal controls. These results provided evidence that the four members of the TIPE family may affect each other to mediate the carcinogenesis of CRC, and that TIPE2 may serve an important role in CRC.

Regulatory Roles of Tumor Necrosis Factor-α-Induced Protein 8 Like-Protein 2 in Inflammation, Immunity and Cancers: A Review

Tumor necrosis factor-alpha (TNF-α)-induced protein 8 (TNFAIP8/TIPE) family, including TNFAIP8 (TIPE), TNFAIP8 like-protein 1 (TNFAIP8L1/TIPE1), TNFAIP8 like-protein 2 (TNFAIP8L2/TIPE2), and TNFAIP8 like-protein 3 (TNFAIP8L3/TIPE3), plays a vital role in regulating inflammatory responses, immune homeostasis, and cancer development. Over the last decade, studies have shown that TIPE2 protein is differentially expressed in diverse cells and tissues. The dysregulation of TIPE2 protein can lead to dysregulation of inflammatory responses and immune homeostasis, and change the basic characteristics of cancers. In consideration of the immeasurable values of TIPE2 in diagnosis, treatment, and prognosis of various human diseases, this review will focus on the expression pattern, structure, and regulatory roles of TIPE2 in inflammation, immunity, and cancers.

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.

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

Background

Gastric cancer (GC) is one of the most common malignant diseases with high morbidity and mortality, especially in Asian countries. During the GC developing progress, TIPE2, a member of TNF-alpha induced protein 8-like (TNFAIP8L) family, may play important roles. However, the molecular mechanisms of TIPE2 contributing to cell proliferation and tumor growth are poorly understood in GC. We performed flow cytometry to detect the cell cycle of TIPE2-knockdown GC cells under lipopolysaccharide (LPS) stimulation.

Methods

We measured TIPE2 expression in tumor samples from 46 human GC patients at mRNA level by Realtime PCR and in 68 pairs of GC tissues at protein level by immunohistochemistry. We established stable TIPE2 knockdown SGC7901 and BGC823 cell lines and performed CCK-8 and EdU proliferation assays under the stimulation of LPS. And then we analyzed AKT, IκBα and ERK phosphorylation levels, as well as cycle related proteins CDK4 and CyclinD3 in the stable TIPE2 knockdown SGC7901 and BGC823 cells.

Results

Our present studies indicated that the expression of TIPE2 was significantly decreased in tumor tissues compared to distant mucosa tissues in human GC patients. TIPE2 inhibited proliferation stimulated by LPS in SGC7901 and BGC823 cells. Silencing of TIPE2 significantly decreased cell G₀/G₁ phase ratio and increased G₂/M phase. TIPE2 knockdown SGC7901 and BGC823 cells declined AKT and IκBα phosphorylation. TIPE2’s action on GC cell cycle was.

Conclusions

Our results demonstrated that TIPE2 is a novel tumor suppressor gene that inhibits GC growth may mediated via AKT and IκBα phosphorylated activation. We revealed that TIPE2 may effectively interdict neoplasm development, which has potential clinical application values for GC targeted therapies.

Hepatitis C Virus and Hepatocellular Carcinoma: Pathogenetic Mechanisms and Impact of Direct-Acting Antivirals

INTRODUCTION

Globally, between 64 and 103 million people are chronically infected with Hepatitis C virus (HCV), with more than 4.6 million people in the United States and is associated with more than 15.000 deaths annually. Chronic infection can result in cirrhosis and hepatocellular carcinoma.

EXPLANATION

Epidemiological studies have indicated that persistent infection with hepatitis C virus (HCV) is a major risk for the development of hepatocellular carcinoma (HCC), mainly through chronic inflammation, cell deaths, and proliferation. Despite the new direct-acting antiviral drugs (DAA's) being able to clear the HCV, HCC recurrence rate in these patients is still observed.

CONCLUSION

In this review we highlighted some aspects that could be involved in the onset of HCV-induced HCC such as immune system, viral factors and host genetics factors.Moreover, we focused on some of the last reports about the effects of DAA's on the HCV clearance and their potential implications in HCC recurrence.

New perspectives of physiological and pathological functions of nucleolin (NCL)

Nucleolin (NCL) is a multifunctional protein that mainly localized in the nucleolus, it is also found in the nucleoplasm, cytoplasm and cell membrane. The three main structural domains allow the interaction of NCL with different proteins and RNA sequences. Moreover, specific post-translational modifications and its shuttling property also contribute to its multifunctionality. NCL has been demonstrated to be involved in a variety of aspects such as ribosome biogenesis, chromatin organization and stability, DNA and RNA metabolism, cytokinesis, cell proliferation, angiogenesis, apoptosis regulation, stress response and microRNA processing. NCL has been increasingly implicated in several pathological processes, especially in tumorigenesis and viral infection, which makes NCL a potential target for the development of anti-tumor and anti-viral strategies. In this review, we present an overview on the structure, localizations and various functions of NCL, and further describe how the multiple functions of NCL are correlated to its multiple cellular distributions.