SCC-S2 is overexpressed in colon cancers and regulates cell proliferation

Tumor necrosis factor-α induced protein 8 (TNFAIP8/TIPE) family is differentially expressed in oral cancer and regulates tumorigenesis through Akt/mTOR/STAT3 signaling cascade

BACKGROUND

Highest incidence of oral cancer is reported in India with reduced survival rate in the advanced stages due to lack of effective biomarkers. Therefore, it is essential to develop novel biomarkers for the better management of this disease. In the current study, TNFAIP8/TIPE protein family comprising of four proteins is explored for its role in oral cancer.

METHODS

IHC analysis of oral cancer TMA and Western blot analysis of tobacco treated oral cancer cells were performed to determine the differential expression of TIPE proteins in oral cancer. Further, CRISPR/Cas9-mediated gene editing was done to generate TIPE proteins' knockouts and MTT, colony formation, wound healing, cell cycle and Western blot analysis were performed to determine the effect of gene knockouts on various cancer hallmarks and the associated molecular targets of TIPE proteins.

RESULTS AND DISCUSSION

IHC results revealed that expression of TIPE, TIPE2 and TIPE3 were upregulated and TIPE1 was downregulated in oral cancer tissues compared to normal tissues. Similar results were observed upon treating oral cancer cells with tobacco carcinogens. Furthermore, knockout of TIPE or TIPE2 or TIPE3 significantly reduced the survival, proliferation, colony formation and migration of oral cancer cells whereas knockout of TIPE1 had an opposite effect. Further, TIPE, TIPE2 and TIPE3 knockout-mediated inhibition of proliferation was associated with inhibition of cell cycle progression at S or G2/M phases, and downregulation of proteins involved in cancer progression. We found that TIPE, TIPE1 and TIPE2 proteins regulate oral cancer progression through modulation of Akt/mTOR signaling cascade, whereas TIPE3 acts through an Akt-independent mTOR/STAT3 pathway.

CONCLUSION

Collectively, the TIPE proteins were proved to play significant roles in the progression of oral cancer thus warranting research and clinic attention for their therapeutic and prognostic values and raising the importance of specific targeting of TIPE proteins in cancer treatment.

Overexpression of Tumour Necrosis Factor-α-Induced Protein 8 is Associated with Prognosis in Colon Cancer

Purpose

The present study aimed to examine the association of tumour necrosis factor-α-induced protein 8 (TIPE) expression levels with clinicopathological features and prognosis of patients with colon cancer following surgery.

Patients and Methods

The present study included 200 patients with colon cancer who underwent colon resection between June 2011 and October 2012. All follow-ups were censored in July 2020, with a median follow-up time of 62.25 months. Kaplan-Meier survival curve analysis and Cox regression analysis were used to determine predictors for the overall survival rate.

Results

High expression of TIPE was associated with lymph node metastasis, higher Dukes' stage and right-sided colon cancer (RCC). An exploratory subgroup analysis found that high expression of TIPE was associated with age ≥65, lymphatic invasion and higher Dukes' stage only in the RCC group (P<0.05), whereas no similar trend was observed in the left-sided colon cancer (LCC) subgroup. Age ≥65, differentiation, lymph node metastasis and TIPE expression levels were independent prognostic factors influencing the survival rate of patients with colon cancer following surgery in multivariate Cox analysis (P<0.05). ROC curve analysis showed that the immunoreactive score of TIPE had good predictive value for five-year survival rates (AUC=0.727) and lymph node metastasis (AUC=0.760) among patients with RCC. Survival analysis revealed that the expression of TIPE had a significant impact on survival, and higher expression levels suggested a worse prognosis.

Conclusion

This study demonstrated that TIPE may be a novel biomarker for predicting the survival outcome and lymph node metastasis. TIPE was overexpressed in colon cancer tissue and significantly associated with poor patient survival, especially in patients with RCC.

TIPE Regulates DcR3 Expression and Function by Activating the PI3K/AKT Signaling Pathway in CRC

Tumor necrosis factor-induced protein-8 (TIPE) is highly expressed in colorectal cancer (CRC). Decoy receptor 3 (DcR3) is a soluble secreted protein that can antagonize Fas ligand (FasL)-induced apoptosis and promote tumorigenesis. It remains unclear whether TIPE can regulate DcR3 expression. In this study, we examined this question by analyzing the relationship between these factors in CRC. Bioinformatics and tissue microarrays were used to determine the expression of TIPE and DcR3 and their correlation in CRC. The expression of TIPE and DcR3 in colon cancer cells was detected. Plasma samples were collected from CRC patients, and DcR3 secretion was measured. Then, dual-luciferase reporter gene analysis was performed to assess the interaction between TIPE and DcR3. We exogenously altered TIPE expression and analyzed its function and influence on DcR3 secretion. Lipopolysaccharide (LPS) was used to stimulate TIPE-overexpressing HCT116 cells, and alterations in signaling pathways were detected. Additionally, inhibitors were used to confirm molecular mechanisms. We found that TIPE and DcR3 were highly expressed in CRC patients and that their expression levels were positively correlated. DcR3 was highly expressed in the plasma of cancer patients. We confirmed that TIPE and DcR3 were highly expressed in HCT116 cells. TIPE overexpression enhanced the transcriptional activity of the DcR3 promoter. TIPE activated the PI3K/AKT signaling pathway to regulate the expression of DcR3, thereby promoting cell proliferation and migration and inhibiting apoptosis. In summary, TIPE and DcR3 are highly expressed in CRC, and both proteins are associated with poor prognosis. TIPE regulates DcR3 expression by activating the PI3K/AKT signaling pathway in CRC, thus promoting cell proliferation and migration and inhibiting apoptosis. These findings may have clinical significance and promise for applications in the treatment or prognostication of CRC.

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.

Inflection of Akt/mTOR/STAT-3 cascade in TNF-α induced protein 8 mediated human lung carcinogenesis

Lung cancer is the leading cause of cancer-related death across the globe. Despite the marked advances in detection and therapeutic approaches, management of lung cancer patients remains a major challenge to oncologists which can be mainly attributed to late stage diagnosis, tumor recurrence and chemoresistance. Therefore, to overthrow these limitations, there arises a vital need to develop effective biomarkers for the successful management of this aggressive cancer type. Notably, TNF-alpha induced protein 8 (TIPE), a nuclear factor-kappa B (NF-κB)-inducible, oncogenic molecule and cytoplasmic protein which is involved in the regulation of T lymphocyte-mediated immunity and different processes in tumor cells such as proliferation, cell death and evasion of growth suppressors, might serve as one such biomarker which would facilitate effective management of lung cancer. Expression studies revealed this protein to be significantly upregulated in different lung cancer types, pathological conditions, stages and grades of lung tumor compared to normal human lung tissues. In addition, knockout of TIPE led to the reduced proliferation, survival, invasion and migration of lung cancer cells. Furthermore, TIPE was found to function through modulation of Akt/mTOR/STAT-3 signaling cascade. This is the first report which shows the involvement of TIPE in tobacco induced lung carcinogenesis. It positively regulated nicotine, NNK, NNN, and BaP induced proliferation, survival and migration of lung cancer cells possibly via Akt/STAT-3 signaling. Thus, this protein possesses important role in the pathogenesis of lung tumor and hence it can be targeted for developing newer therapeutic interventions for the clinico-management of lung cancer.

RNAi Screening Identifies that TEX10 Promotes the Proliferation of Colorectal Cancer Cells by Increasing NF-κB Activation

Colorectal cancer (CRC) has become a predominant cancer worldwide. To understand the process of carcinogenesis, a short hairpin RNA library screening is employed to search for candidate genes that promote proliferation in the CRC cell line HT29. The candidate genes overlap with differentially expressed genes in 32 CRC tumor tissues in the GEO dataset GSE8671. The seventh-ranked testis expressed 10 (TEX10) is upregulated in CRC and its knockdown decreases cell proliferation. The TEX10 high-expression group exhibits worse overall survival (P = 0.003) and progression-free survival (P = 0.001) than the TEX10 low-expression group. TEX10 depletion decreases the growth of CRC cells in vitro and in vivo. Gene set enrichment analysis indicates that the nuclear factor-kappa B pathway is significantly enriched in the genes downregulated by TEX10 knockdown. Mechanistically, TEX10 interacts with RELA and increases its nuclear localization. TEX10 promotes RELA occupancy at gene promoters and regulates the expression of a subset of RELA-targeted genes, including TNFAIP8, SAT1, and IL6ST. Taken together, this study identifies that TEX10 promotes the proliferation of CRC cells in an RELA-dependent manner. In addition, high TEX10 expression is associated with poor prognosis in CRC patients.

TIPE regulates VEGFR2 expression and promotes angiogenesis in colorectal cancer

Background: Metastasis is the leading cause of death in colorectal cancer (CRC) patients. It is regulated mainly by tumor cell angiogenesis, and angiogenesis is caused by the binding of vascular endothelial growth factor (VEGF) to vascular endothelial growth factor receptor 2 (VEGFR2). Tumor necrosis factor-α-induced protein 8 (TNFAIP8, hereto after TIPE) plays an important role in tumorigenesis, development, and prognosis. However, the relationship between TIPE and VEGFR2 in CRC angiogenesis and the mechanism of action remain unknown.

Method: In this study, we used quantitative real-time PCR, Western blotting and immunohistochemistry to detect TIPE and VEGFR2 expression in 55 specimens from CRC patients. We also used HCT116 CRC cells and human umbilical vein endothelial cells (HUVECs) for in vitro experiments by stably transducing shTIPE and shRNA control lentivirus into HCT116 cells, detecting VEGFR2 expression after TIPE knockdown and repurposing the culture supernatant as conditioned medium to stimulate angiogenesis of HUVECs. In vivo experiments with chicken chorioallantoic membranes (CAMs) and a nude mouse matrix subcutaneous tumor model were performed to validate the effects of TIPE on angiogenesis. Additionally, we analyzed the expression and phosphorylation levels of PDK1 and blocked PDK1 expression using inhibitors to determine whether TIPE-induced changes in VEGFR2-mediated angiogenesis acted via the PI3K-Akt pathway.

Results: We found that TIPE and VEGFR2 are highly expressed in CRC and act as oncogenes. TIPE knockdown also downregulated VEGFR2 expression, which resulted in simultaneous inhibition of cell proliferation, cell migration and angiogenesis. Then, in vivo experiments further demonstrated that TIPE promotes angiogenesis in CRC. Finally, we found that TIPE promotes VEGFR2-mediated angiogenesis by upregulating PDK1 expression and phosphorylation and that blocking PDK1 expression can inhibit this process.

Conclusion: TIPE promotes angiogenesis in CRC by regulating the expression of VEGFR2, which may be a target for antiangiogenic cancer therapy.

TIPE Family of Proteins and Its Implications in Different Chronic Diseases

The tumor necrosis factor-α-induced protein 8-like (TIPE/TNFAIP8) family is a recently identified family of proteins that is strongly associated with the regulation of immunity and tumorigenesis. This family is comprised of four members, namely, tumor necrosis factor-α-induced protein 8 (TIPE/TNFAIP8), tumor necrosis factor-α-induced protein 8-like 1 (TIPE1/TNFAIP8L1), tumor necrosis factor-α-induced protein 8-like 2 (TIPE2/TNFAIP8L2), and tumor necrosis factor-α-induced protein 8-like 3 (TIPE3/TNFAIP8L3). Although the proteins of this family were initially described as regulators of tumorigenesis, inflammation, and cell death, they are also found to be involved in the regulation of autophagy and the transfer of lipid secondary messengers, besides contributing to immune function and homeostasis. Interestingly, despite the existence of a significant sequence homology among the four members of this family, they are involved in different biological activities and also exhibit remarkable variability of expression. Furthermore, this family of proteins is highly deregulated in different human cancers and various chronic diseases. This review summarizes the vivid role of the TIPE family of proteins and its association with various signaling cascades in diverse chronic diseases.

SCC-S2 Facilitates Tumor Proliferation and Invasion via Activating Wnt Signaling and Depressing Hippo Signaling in Colorectal Cancer Cells and Predicts Poor Prognosis of Patients

SCC-S2 overexpression has been implicated in several human cancers, its correlation with prognosis and the mechanism how it reserved biological roles are still uncertain. The current study demonstrated that, in 142 archived colorectal carcinoma (CRC) tissue samples, SCC-S2 expression was significantly correlated with higher histological grade ( p=0.001), tumor invasion ( p=0.001), advanced Dukes staging ( p=0.002), positive regional lymph node metastasis ( p=0.024), and poor overall survival ( p<0.001). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and Transwell assays showed that SCC-S2 significantly promoted the proliferation and invasion. SCC-S2 expression was also accompanied by the overexpression CyclinD1, matrix metalloproteinase-7 (MMP-7), active-β-catenin, yes-associated protein (YAP), and connective tissue growth factor (CTGF), as well as the depression of p-large tumor suppressor kinase 1 (p-LATS1) and p-YAP. Moreover, SCC-S2 interacted and colocalized with LATS1, the interaction may interrupt Hippo signaling and thereafter activate canonical Wnt signaling. In conclusion, our data suggested that SCC-S2 was associated with the progression and unfavorable prognosis of CRCs. Meanwhile, SCC-S2 facilitated canonical Wnt signaling and its downstream effectors (CyclinD1, MMP-7) and promoted tumor proliferation and invasion, which depended on the inhibition of Hippo signaling induced by SCC-S2-LATS1 interaction. These results indicated that SCC-S2 might be used as a novel target for the prevention and treatment of colorectal cancer.

TNFAIP8 promotes the proliferation and cisplatin chemoresistance of non-small cell lung cancer through MDM2/p53 pathway

Background

The highly refractory nature of non-small cell lung cancer (NSCLC) to chemotherapeutic drugs is an important factor resulting in its poor prognosis. Recent studies have revealed that tumour necrosis factor alpha-induced protein 8 (TNFAIP8) is involved in various biological and pathological processes of cells, but their underlying mechanisms in processes ranging from cancer development to drug resistance have not been fully elucidated.

Methods

TNFAIP8 expression in clinical NSCLC samples was examined through immunohistochemistry (IHC). After adjusting for patients’ characteristics with propensity score matching, Kaplan-Meier analysis and Cox regression analysis were performed for comparison of patients’ survival according to the TNFAIP8 level. Lentiviral transfection with TNFAIP8-specific shRNAs was used to establish stable TNFAIP8 knockdown (TNFAIP8 KD) NCI-H460, A549 and cis-diamminedichloroplatinum II resistant A549 (A549/cDDP) cell lines. Cell proliferation and viability were assessed by CCK-8 assay. Cell cycle was examined by flow cytometry. Multiple pathways regulated by TNFAIP8 KD were revealed by microarray analysis.

Results

We found that high TNFAIP8 expression was associated with advanced pT stage, advanced pTNM stage, lymph node metastasis and unfavourable survival in NSCLC patients. TNFAIP8 shRNAs reduced in vitro cancer cell proliferation and in vivo tumor growth. Additionally, TNFAIP8 KD increased the sensitivity of NSCLC cells to cisplatin in vitro and in vivo. Conversely, up-regulation of TNFAIP8 promoted the proliferation and drug resistance to cisplatin of NSCLC cells. TNFAIP8 influences cancer progression pathways involving the MDM2/p53 pathway. Indeed, we observed that TNFAIP8 KD mediated the MDM2 downregulation and the p53 ubiquitination, thereby decreasing the degradation of p53 protein. shRNA p53 reversed TNFAIP8 shRNA-mediated regulation of cell proliferation, cell cycle, cisplatin sensitivity, and expression levels of RAD51, a DNA repair gene.

Conclusion

Our work uncovers a hitherto unappreciated role of TNFAIP8 in NSCLC proliferation and cisplatin chemoresistance that is mediated through the MDM2/p53 pathway. These findings might offer potential therapeutic targets for reversing cisplatin resistance in NSCLC patients with high TNFAIP8 expression.

Electronic supplementary material

The online version of this article (10.1186/s12964-018-0254-x) contains supplementary material, which is available to authorized users.

Tumor Necrosis Factor-α Induced Protein 8: Pathophysiology, Clinical Significance, and Regulatory Mechanism

Tumor necrosis factor-α-induced protein-8 (TNFAIP8) is the earliest discovered component of TNFAIP8 family [tumor necrosis factor-α-induced protein-8 like (TIPE) family]. TNFAIP8 contains a putative death effector domain (DED) homologous to DED II in FLIP (Fas-associated death domain-like interleukin-1β-converting enzyme-inhibitory protein), which may affect cell survival/death process. Recently, it has been demonstrated that TNFAIP8 could inhibit apoptosis and autophagy in various types of cells. Moreover, TNFAIP8 level fluctuated evidently in patients with inflammatory, malignant, and autoimmune diseases, indicating that it might be an anti-apoptotic and oncogenetic protein. Herein we will review the discovery, gene/protein structure, pathophysiological functions, and clinical significance of TNFAIP8 together with its potential regulatory mechanism.

The novel p53 target TNFAIP8 variant 2 is increased in cancer and offsets p53-dependent tumor suppression

Tumor necrosis factor-α-induced protein 8 (TNFAIP8) is a stress-response gene that has been associated with cancer, but no studies have differentiated among or defined the regulation or function of any of its several recently described expression variants. We found that TNFAIP8 variant 2 (v2) is overexpressed in multiple human cancers, whereas other variants are commonly downregulated in cancer (v1) or minimally expressed in cancer or normal tissue (v3-v6). Silencing v2 in cancer cells induces p53-independent inhibition of DNA synthesis, widespread binding of p53, and induction of target genes and p53-dependent cell cycle arrest and DNA damage sensitization. Cell cycle arrest induced by v2 silencing requires p53-dependent induction of p21. In response to the chemotherapeutic agent doxorubicin, p53 regulates v2 through binding to an intragenic enhancer, together indicating that p53 and v2 engage in complex reciprocal regulation. We propose that TNFAIP8 v2 promotes human cancer by broadly repressing p53 function, in essence offsetting p53-dependent tumor suppression.

Tumor necrosis factor α-induced protein 8-like 1 promotes apoptosis by regulating B-cell leukemia/lymphoma-2 family proteins in RAW264.7 cells

Although the newly identified protein tumor necrosis factor α-induced protein 8-like 1 (TNFAIP8L1), also known as TIPE1, has been reported to be able to induce apoptosis in human hepatocellular carcinoma cells, the involvement of TIPE1 in apoptosis remains to be elucidated. The present study investigated the pro-apoptotic effect of TIPE1 in an murine macrophage cell line, RAW264.7. The cell apoptosis rate was detected by flow cytometry. The results revealed that overexpressed TIPE1 could directly enhance the apoptosis and the cisplatin-induced cell death of RAW264.7 cells in vitro. Meanwhile, TIPE1 overexpression could suppress tumor growth in vivo. Furthermore, western blotting revealed that overexpressed TIPE1 could upregulate the expression of B-cell leukemia/lymphoma (Bcl)-2 associated X protein (Bax), Bcl-2 interacting killer (Bik) and p53 upregulated modulator of apoptosis (Puma), and activate the mitogen activated protein kinases (MAPKs) signaling pathway. However, western blotting demonstrated that inhibitors of the MAPKs pathway could not decrease the expression of Bax, Bik or Puma. These results indicated that TIPE1 could promote the apoptosis of RAW264.7 cells by upregulating the pro-apoptotic members of the Bcl-2 family of proteins, and that the MAPKs signaling pathway was not involved in the pro-apoptotic effect of TIPE1.

TNFAIP8 overexpression: a potential predictor of lymphatic metastatic recurrence in pN0 esophageal squamous cell carcinoma after Ivor Lewis esophagectomy

Esophageal squamous cell carcinoma (ESCC) has a poor prognosis due to high lymphatic metastatic recurrence rates after Ivor Lewis esophagectomy. We sought to investigate the correlation between tumor necrosis factor alpha-induced protein 8 (TNFAIP8) expression and postoperative lymphatic recurrence in patients with pN0 ESCC. One hundred twenty-two patients with pN0 ESCC undergoing Ivor Lewis esophagectomy were enrolled in this study. TNFAIP8 overexpression was found in 73 (59.8 %) tumor specimens. The 3-year lymphatic metastatic recurrence rate among TNFAIP8-overexpressing patients was significantly higher than in TNFAIP8-negative patients (p = 0.003). Multivariate Cox regression identified TNFAIP8 overexpression as an independent risk factor for lymphatic recurrence (p = 0.048). TNFAIP8 messenger RNA (mRNA) levels were significantly higher in patients with lymphatic recurrence than in patients without tumor recurrence (p = 0.019). Stable silencing of TNFAIP8 expression in ESCC-derived cells (Eca109) reduced proliferation, motility, and invasion and induced apoptosis. In addition, transient silencing of TNFAIP8 expression decreased cell motility and invasion and increased apoptosis in a second ESCC-derived cell line (KYSE150). Taken together, these findings suggest that TNFAIP8 overexpression is a potential biomarker to identify pN0 ESCC patients at higher risk of lymphatic recurrence who may benefit from adjuvant therapy.

A rare DNA contact mutation in cancer confers p53 gain-of-function and tumor cell survival via TNFAIP8 induction

The p53 tumor suppressor gene encodes a sequence-specific transcription factor. Mutations in the coding sequence of p53 occur frequently in human cancer and often result in single amino acid substitutions (missense mutations) in the DNA binding domain (DBD), blocking normal tumor suppressive functions. In addition to the loss of canonical functions, some missense mutations in p53 confer gain-of-function (GOF) activities to tumor cells. While many missense mutations in p53 cluster at six "hotspot" amino acids, the majority of mutations in human cancer occur elsewhere in the DBD and at a much lower frequency. We report here that mutations at K120, a non-hotspot DNA contact residue, confer p53 with the previously unrecognized ability to bind and activate the transcription of the pro-survival TNFAIP8 gene. Mutant K120 p53 binds the TNFAIP8 locus at a cryptic p53 response element that is not occupied by wild-type p53. Furthermore, induction of TNFAIP8 is critical for the evasion of apoptosis by tumor cells expressing the K120R variant of p53. These findings identify induction of pro-survival targets as a mechanism of gain-of-function activity for mutant p53 and will likely broaden our understanding of this phenomenon beyond the limited number of GOF activities currently reported for hotspot mutants.

Association between the expression levels of tumor necrosis factor-α-induced protein 8 and the prognosis of patients with gastric adenocarcinoma

The present study aimed to investigate the expression levels of tumor necrosis factor-α-induced protein 8 (TNFAIP8) in gastric adenocarcinoma. TNFAIP8 expression levels in gastric adenocarcinoma tissue samples (with and without lymph node metastasis), adjacent normal tissue samples and metastatic lymph node tissue samples were detected by immunohistochemistry. The correlation between TNFAIP8 expression levels and clinicopathological data and gastric adenocarcinoma prognosis was analyzed. The results demonstrated that TNFAIP8 expression in gastric adenocarcinoma tissue samples and metastatic lymph node tissue samples markedly increased at a rate of 47.2% (50/106) and 81.7% (49/60), respectively, as compared with the adjacent normal tissue samples in which no TNGFAIP8 expression was detected (0%). This increase in TNFAIP8 expression was statistically significant. TNFAIP8 expression rates in the primary tumors (60%, 36/60) of patients with lymph node metastasis were significantly higher compared with the primary tumors of patients without lymph node metastasis (30.4%, 14/46). TNFAIP8 expression was associated with an increase in the severity of TNM stage, tumor grade, vascular invasion, lymph node metastasis and serum CA72-4 levels. The overall survival rate of patients with gastric adenocarcinoma and high TNFAIP8 expression was poorer compared with patients with low TNFAIP8 expression, and TNFAIP8 expression was negatively correlated with patient prognosis. The results also demonstrated that TNFAIP8 was an independent prognostic marker in gastric adenocarcinoma (relative risk, 1.736; P=0.029). In conclusion, the results of the present study demonstrated that TNFAIP8 expression was associated with the occurrence, development and metastasis of gastric adenocarcinoma, and negatively correlated with the prognosis of patients with gastric adenocarcinoma. TNFAIP8 may therefore serve as a prognostic factor for gastric adenocarcinoma.

miR-935 promotes gastric cancer cell proliferation by targeting SOX7

Gastric cancer is the most common cancer in the world, miRNAs have been demonstrated to play critical role in the development and progression of gastric cancer, such as miR-7, miR-217 and miR-335. Here, we found miR-935 was upregulated in gastric cancer tissues and cells. Overexpression of miR-935 promoted cell proliferation and tumorigenesis in vitro determined by MTT analysis, colony formation analysis, BrdU cell proliferation analysis and soft agar growth analysis, knockdown of miR-935 reduced these effects. Tumor suppressor sex-determining region Y-box 7 (SOX7) was the direct target of miR-935, overexpression of miR-935 inhibited SOX7 expression, but promoted the levels CCND1 and C-MYC which promotes cell proliferation and tumorigenesis, knockdown of miR-935 increased SOX7 level, and inhibited CCND1 and C-MYC expression. Synchronous knockdown of miR-935 and SOX7 promoted cell proliferation and tumorigenesis in vitro, confirming miR-935 regulated gastric cancer cell proliferation by inhibiting SOX7. In summary, we found miR-935 contributed to cell proliferation of gastric cancer through targeting SOX7.

Expression of tumor necrosis factor α-induced protein 8 is upregulated in human gastric cancer and regulates cell proliferation, invasion and migration

Tumor necrosis factor α-induced protein 8 (TNFAIP8) has been associated with the tumorigenicity of various types of cancer, however, the expression of TNFAIP8 and its function in gastric cancer remain to be fully elucidated. Therefore, the present study examined the expression and biological function of TNFAIP8 in gastric cancer. The expression levels of TNFAIP8 were determined in 86 gastric cancer tissue samples and adjacent normal tissues using immunohistochemistry, and in four gastric cancer cell lines and GES-1 cells using reverse transcription-quantitative polymerase chain reaction. The expression of TNFAIP8 and its association with the tumor, node, metastasis (TNM) status and lymphatic metastasis of gastric cancer was evaluated. Furthermore, the functions of decreased expression levels of TNFAIP8 were analyzed in human gastric cancer cell lines. The expression of TNFAIP8 was significantly upregulated in the gastric cancer tissues and in the gastric cancer cell lines, and its expression levels were associated with the TNM staging and lymphatic metastasis. Furthermore, decreased expression of TNFAIP8 inhibited the growth, invasion and migration of gastric cancer cells. These data provided an innovative insight suggesting the downregulation of TNFAIP8 as a meaningful approach for treating human gastric cancer and other types of cancer. In addition, the expression levels of TNFAIP8 may be considered as a biomarker of gastric cancer progression.

TIPE1 induces apoptosis by negatively regulating Rac1 activation in hepatocellular carcinoma cells

TIPE1 (tumor necrosis factor-α-induced protein 8-like 1 or TNFAIP8L1) is a newly identified member of the TIPE (TNFAIP8) family, which play roles in regulating cell death. However, the biologic functions of TIPE1 in physiologic and pathologic conditions are largely unknown. Here, we report the roles of TIPE1 in hepatocellular carcinoma (HCC). Evaluated by immunohistochemical staining, HCC tissues showed significantly downregulated TIPE1 expression compared with adjacent non-tumor tissues, which positively correlated with tumor pathologic grades and patient survival. Using a homograft tumor model in Balb/c mice, we discovered that TIPE1 significantly diminished the growth and tumor weight of murine liver cancer homografts. Consistently, TIPE1 inhibited both cell growth and colony formation ability of cultured HCC cell lines, which was further identified to be due to TIPE1-inducing apoptosis in a caspase-independent, necrostatin-1 (Nec-1)-insensitive manner. Furthermore, mechanistic investigations revealed that TIPE1 interacted with Rac1, and inhibited the activation of Rac1 and its downstream p65 and c-Jun N-terminal kinase pathway. Moreover, overexpression of constitutively active Rac1 partially rescued the apoptosis induced by TIPE1, and Rac1 knockdown significantly restored the deregulated cell growth induced by TIPE1 small interfering RNA. Our findings revealed that TIPE1 induced apoptosis in HCC cells by negatively regulating Rac1 pathway, and loss of TIPE1 might be a new prognostic indicator for HCC patients.

TNFAIP8 overexpression is associated with lymph node metastasis and poor prognosis in intestinal-type gastric adenocarcinoma

AIMS

Tumour necrosis factor alpha-induced protein 8 (TNFAIP8) is implicated in the progression of several human malignancies, but its role in gastric adenocarcinoma is unknown. TNFAIP8 expression and its correlation with clinical significance in gastric adenocarcinoma are evaluated in this study.

METHODS AND RESULTS

The expression of TNFAIP8 was determined in primary gastric adenocarcinoma tissues using immunohistochemistry (IHC) and Western blotting analysis. TNFAIP8 expression was higher in gastric adenocarcinoma tissues. Elevated expression of TNFAIP8 in gastric adenocarcinoma was associated significantly with depth of invasion (P = 0.024), lymph node metastasis (P = 0.038) and Lauren classification (P = 0.048). Patients with tumours showing high TNFAIP8 expression had a significantly poorer overall survival (OS) and disease-free survival (DFS) than those with low TNFAIP8 expression in intestinal-type gastric adenocarcinoma (IGA) (P = 0.001 for both). In the multivariate Cox analysis, TNFAIP8 expression was an independent prognostic marker for OS and DFS in IGA with P-values of 0.006 and 0.007, respectively.

CONCLUSIONS

Our data suggest that TNFAIP8 overexpression may contribute to lymph node metastasis and poor prognosis in IGA.

Correlation of TNFAIP8 overexpression with the proliferation, metastasis, and disease-free survival in endometrial cancer

Tumor necrosis factor alpha-induced protein 8 (TNFAIP8) is an apoptosis regulator proven to have an important function in the proliferation, invasion, metastasis, and progression of malignancies. In this study, we investigated the clinical role of TNFAIP8 overexpression in endometrial cancer (EC) and determined the relationship of TNFAIP8 with the proliferative antigen Ki-67 and metastasis-related gene matrix metallopeptidase 9 (MMP9) in 225 tumor specimens by immunohistochemistry and western blot, in order to elucidate more information on the role of TNFAIP8 protein with regard to the pathogenesis of EC. An association was observed between TNFAIP8 overexpression and clinicopathologic factors, such as advanced International Federation of Gynecology and Obstetrics stage (P<0.001), higher histologic grade (P=0.017), deep myometrial invasion (P=0.030), lymphovascular space invasion (P=0.011), lymph node metastasis (P<0.001), and recurrence. Furthermore, TNFAIP8 overexpression was strongly correlated with MMP9 and Ki-67 expression in the progression of ECs. Patients with high expression of TNFAIP8 (P<0.001 for both) and Ki-67 (P=0.007 and P=0.008) had poor overall survival and disease-free survival (DFS) rates. MMP9 overexpression did not affect survival outcomes (P>0.05). Multivariate Cox regression analysis revealed that TNFAIP8 (P=0.029) and lymph node metastasis (P=0.022) were independent factors of DFS in patients with EC. These findings suggested that TNFAIP8 may be used as a prognostic marker for the recurrence of EC, and its promotion of the proliferation and metastasis in EC may be due to its mediation of Ki-67 and MMP9.

TNFAIP8 overexpression is associated with platinum resistance in epithelial ovarian cancers with optimal cytoreduction

Here, we correlated tumor necrosis factor α-induced protein 8 (TNFAIP8) messenger RNA (mRNA) expression with clinicopathological parameters and investigated the involvement of TNFAIP8 overexpression in platinum resistance of epithelial ovarian cancer (EOC). The status of TNFAIP8 protein was evaluated by Western blot analysis (n = 25) and immunohistochemistry (n = 134). TNFAIP8 mRNA expression was assessed with real-time polymerase chain reaction in fresh frozen EOC tissues (n = 40). TNFAIP8 overexpression at both mRNA and protein levels in platinum-resistant disease was clearly higher than that in platinum-sensitive disease (P < .05). Platinum resistance was independently correlated with residual tumor size (P = .025), ascites (P = .027), and TNFAIP8 overexpression (P = .003). In particular, TNFAIP8 overexpression was correlated with platinum resistance in EOCs with optimal cytoreduction (P = .001). TNFAIP8 mRNA expression was strongly associated with residual tumor size (P = .019). In conclusion, our findings indicate that TNFAIP8 overexpression is an independent predictor of platinum resistance and may be a potential biomarker for targeted therapy.

Variance of TNFAIP8 expression between tumor tissues and tumor-infiltrating CD4+ and CD8+ T cells in non-small cell lung cancer

Tumor necrosis factor alpha-induced protein 8 (TNFAIP8) has been recently documented in various malignancies, but its role in non-small cell lung cancer (NSCLC) remains uncertain. In the current study, we investigated the level of TNFAIP8 in NSCLC tissues, adjacent noncancerous lung tissues, healthy lung tissues, CD4+ T cells, and CD8+ T cells by real-time reverse transcription PCR (RT-PCR) and Western blot analysis. Results revealed that the mRNA level of TNFAIP8 was significantly increased in cancer tissue than in healthy lung tissue from donors (p < 0.001). Interestingly, adjacent noncancerous lung tissues also showed higher mRNA level of TNFAIP8 than healthy lung tissue from donors (p < 0.01). Similarly, protein level of TNFAIP8 was elevated in NSCLC tissues and adjacent noncancerous lung tissues. We further analyzed TNFAIP8 expression in CD4+ T cells and CD8+ T cells. Data demonstrated that both mRNA level and protein level were significantly decreased in tumor-infiltrating CD4+ and CD8+ T cells than in peripheral CD4+ and CD8+ T cells. Moreover, patients with advanced stages presented lower protein expression of TNFAIP8 in tumor-infiltrating CD8+ T cells than patients with primary stages (p < 0.05). These results provide evidence that TNFAIP8 plays critical roles in NSCLC and may be used as a therapeutic target for the disease.

TNFAIP8 as a predictor of metastasis and a novel prognostic biomarker in patients with epithelial ovarian cancer

Background:

Tumour necrosis factor-α-induced protein 8 (TNFAIP8) has been recently documented in various malignancies, but its role in epithelial ovarian cancer (EOC) remains unknown.

Methods:

Tumour necrosis factor-α-induced protein 8 expression was determined by real-time reverse transcription PCR and western blot analysis. Tumour tissues, consisting of serous, mucinous, endometrioid and clear cell histotypes, from 202 EOC patients (International Federation of Gynecologists and Obstetricians I–IV) who underwent primary cytoreduction were collected. Then, we examined the immunohistochemical expression of TNFAIP8 and evaluated its clinical significances.

Results:

Tumour necrosis factor-α-induced protein 8 overexpression was significantly associated with high histologic grade (P=0.005), large residual tumour size (P=0.014), recurrence (P=0.024) and response to chemotherapy (P<0.001). Multivariate analysis showed that TNFAIP8 overexpression was independently correlated with the presence of lymph node (odds ratio (OR): 4.129; 95% confidence interval (CI): 1.491–11.435; P=0.006) and intraperitoneal metastasis (OR: 2.209; 95% CI: 1.174–4.156; P=0.014). Moreover, results revealed that the status of TNFAIP8 expression was an independently prognostic factor for both cancer-specific survival (hazard ratio (HR): 1.852; 95% CI: 1.322–2.594; P<0.001) and disease-free survival (HR: 1.724; 95% CI: 1.235–2.407; P=0.001) in patients with EOC.

Conclusion:

The present data provide evidence that TNFAIP8 predicts EOC metastasis and poor survival, highlighting its potential function as a therapeutic target for EOCs.