The ubiquitin-like protein FAT10 and the homeobox protein HOXB9 each promote metastatic progression in hepatocellular carcinoma (HCC). In this study, we investigated the clinicopathologic significance of FAT10 and HOXB9 in HCC and investigated a mechanistic role for FAT10 in HOXB9-mediated invasiveness and metastasis. Relative to adjacent normal tissues, FAT10 and HOXB9 were markedly overexpressed in HCC, where a positive correlation in their expression and associated malignant characteristics were found. RNAi-mediated silencing of FAT10 decreased HOXB9 expression and inhibited HCC invasion and metastasis in vitro and in vivo. The effects of FAT10 silencing were reversed by HOXB9 overexpression, whereas RNAi-mediated silencing of HOXB9 decreased HCC invasion and metastasis driven by FAT10 overexpression. Mechanistically, FAT10 regulated HOXB9 expression by modulating the b-catenin/TCF4 pathway, directly binding to b-catenin and preventing its ubiquitination and degradation. Together, our results identified a novel HCC regulatory circuit involving FAT10, b-catenin/TCF4, and HOXB9, the dysfunction of which drives invasive and metastatic character in HCC.

Human HLA-F adjacent transcript 10 (FAT10) is the only ubiquitin-like protein that can directly target substrates for degradation by proteasomes, but it can also stabilize the expression of certain substrates by antagonizing ubiquitination, through mechanisms as yet uncharacterized. In this study, we show how FAT10 stabilizes the translation elongation factor eEF1A1, which contributes to cancer cell proliferation. FAT10 overexpression increased expression of eEF1A1, which was sufficient to promote proliferation of cancer cells.Mechanistic investigations revealed that FAT10 competed with ubiquitin (Ub) for binding to the same lysines on eEF1A1 to form either FAT10-eEF1A1 or Ub-eEF1A1 complexes, respectively, such that FAT10 overexpression decreased Ub-eEF1A1 levels and increased FAT10-eEF1A1 levels. Overall, our work establishes a novel mechanism through which FAT10 stabilizes its substrates, advancing understanding of the biological function of FAT10 and its role in cancer. Cancer Res; 76(16); 4897-907.Ó2016 AACR.

Interferon‐induced transmembrane protein 3 (IFITM3) has been shown to be overexpressed in multiple cancers. However, the role of IFITM3 in metastasis of hepatocellular carcinoma (HCC) is still poorly understood. In this study, we showed that IFITM3 was frequently overexpressed in HCC tissues compared with adjacent nontumor tissues. Overexpression of IFITM3 was significantly correlated with tumor metastasis and poor prognosis in HCC. Knockdown of IFITM3 dramatically decreased MMP9 expression and inhibited the invasion and metastasis of HCC in vitro and in vivo . Moreover, the upregulation of MMP9 rescued the decreased migration and invasion induced by the knockdown of IFITM3, whereas the knockdown of MMP9 decreased IFITM3‐enhanced HCC migration and invasion. Mechanistically, we found that IFITM3 regulates MMP9 expression through the p38/MAPK pathway. Taken together, we identified a novel IFITM3–p38/MAPK–MMP9 regulatory circuitry, the dysfunction of which drives invasive and metastatic character in HCC.

PurposeTumor-infiltrating FoxP3+ T cells have been reported in various human tumors, which impaired cell-mediated immunity and promoted disease progression. However, its prognostic value for survival in patients with different gastrointestinal cancers [hepatocellular carcinoma (HCC), colorectal cancer (CRC), gastric cancer (GC)] remains controversial.MethodsRelevant literature was searched using PubMed, Embase, Cochrane, Ovid Medline and Chinese wanfang databases. A meta-analysis was conducted to estimate pooled survival and recurrence ratios. The odds ratio (OR) and 95% confidence intervals (CI) were calculated employing fixed- or random-effects models depending on the heterogeneity of the included trials.ResultsFor HCC and GC, the overall survival at 1, 3 and 5-year of high FoxP3+ T cells infiltration patients were lower than low FoxP3+ T cells infiltration patients (P<0.05). The recurrences at 1, 3 and 5-year of high FoxP3+ T cells infiltration patients were higher than low FoxP3+ T cells infiltration patients (P<0.001). But for CRC, the overall survival at 1, 3 and 5-year of high FoxP3+ T cells infiltration patients were higher than low FoxP3+ T cells infiltration patients (P<0.001). There were no differences in 1, 3 and 5-year recurrences between high and low FoxP3+ T cells infiltration patients (P>0.05).ConclusionsOur findings suggested that tumor-infiltrating FoxP3+ T cells were a factor for a poor prognosis for HCC and GC, but a good prognosis for CRC.

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Recently, studies on transcriptome-proteome relationships have revealed mRNA/protein expression discordance for certain genes and speculated that protein posttranslational modification (PTM) may be involved. However, there is currently no evidence to support this hypothesis. Wnt-induced secreted protein-1 (WISP1) is the downstream target gene of β-catenin and plays an important role in tumorigenesis and progression, but the expression and role of WISP1 in different tumor types are controversial. Here, we first confirmed that WISP1 protein expression was significantly down-regulated in hepatocellular carcinoma (HCC) tissue and could be an independent predictor of poor prognosis for patients with HCC. In vivo and in vitro evidence was provided that WISP1 can suppress HCC cell proliferation. Further studies have found that low WISP1 protein expression was related to expression of human leukocyte antigen F locus adjacent transcript 10 (FAT10), a specific ubiquitin-like protein with both degradation and stabilization functions, which plays an important role in PTM. FAT10 overexpression facilitated WISP1 degradation by FAT10ylation to decrease WISP1 protein expression, thus promoting HCC proliferation. Interestingly, we found and demonstrated that FAT10 overexpression could result in WISP1 protein/mRNA expression discordance, with protein expression decreasing while mRNA expression increased. The underlying mechanism is that FAT10 exerts substrate stabilization and degradation functions simultaneously, while FAT10 overexpression promotes WISP1 mRNA expression by stabilizing β-catenin and directly degrades WISP1 protein. Conclusion: Our study demonstrated that overexpression of FAT10 results in expression discordance between WISP1 protein and mRNA, thereby promoting HCC progression by down-regulating WISP1 protein expression.

Background Our aim was to determine the epidemiology and recent changes in the trends of non-functional pancreatic neuroendocrine tumours (NF-pNETs) at the population level. In addition, we explored the risk factors that are associated with survival duration. Methods Cases were identified form the Surveillance, Epidemiology, and End Results (SEER) Programme database from 2000 to 2014. Data on incidence and incidence-based (IB) mortality for NF-pNET were obtained from this database. Secular trends in age-adjusted incidence and IB mortality were determined by using the Joinpoint Regression program. Data analyses were performed using chi-square tests, Kaplan-Meier curves and Cox proportional hazards regression. Results Overall, 4766 patients diagnosed with NF-pNET with a median age of 59 years were identified through our descriptive criteria. Caucasian patients accounted for the majority of the study population, and the proportion of patients with distant disease significantly decreased during our study period. Overall, there was an increase in incidence and IB mortality for NF-pNET; however, the rate of increase decreased during the recent years. In addition, the incidence trends of NF-pNET located in the pancreatic head significantly increased, and rates fo increase in IB mortality for NF-pNET in the pancreatic tail decreased in recent years. Additionally, the 1-, 5-, and 10-year survival rates were 79.0, 51.8, 38.1%, respectively. Furthermore, patient age, tumour grade, stage at diagnosis, tumour size, tumour site and resection were associated with mortality. Conclusion Despite increases in incidence and IB mortality, the rate of change in IB mortality for NF-pNET has decreased in recent years. Survival duration displayed a secular increase during the overall period, and the prognosis and survival duration of patients were closely related to the time of diagnosis, age of the patients and size and location of the tumour. Appropriate treatment adjustments based on tumour stage may thus facilitate improvements in patient outcomes. Electronic supplementary material The online version of this article (10.1186/s12885-019-5543-2) contains supplementary material, which is available to authorized users.

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