Retraction Notice to: miRNA-129/FBW7/NF-κB, a Novel Regulatory Pathway in Inflammatory Bowel Disease.

[This retracts the article DOI: 10.1016/j.omtn.2019.10.048.].

IGF2BP1-mediated N6-methyladenosine modification promotes intrahepatic cholangiocarcinoma progression.

N6-methyladenosine (m6A) RNA methylation and its associated RNA-binding protein insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) are involved in tumor initiation and progression. Here, we explored the biological function and clinical significance of IGF2BP1 in intrahepatic cholangiocarcinoma (iCCA). We found that IGF2BP1 expression was upregulated by H3K27 acetylation enrichment of its promoter, which positively correlated with poor clinicopathological characteristics and survival. Gain- and loss-of-function experiments showed that IGF2BP1 overexpression (knockdown) enhanced (attenuated) iCCA growth and metastasis in vitro and in vivo. Mechanistically, IGF2BP1 not only regulated the c-Myc/p16 axis to promote iCCA growth and inhibit senescence, but also activated the ZIC2/PAK4/AKT/MMP2 axis to induce tumor metastasis. More importantly, BTYNB, a recently identified IGF2BP1 inhibitor, exerted promising anti-tumor efficacy in a patient-derived xenograft (PDX) model, and IGF2BP1 conditional knockout (cKO) reduced the tumor burden. These results demonstrate the crucial role of IGF2BP1 in iCCA progression via m6A-dependent modification, highlighting IGF2BP1 as a potential therapeutic target in iCCA.

COUP-TFII promotes metastasis and epithelial-to-mesenchymal transition through upregulating Snail in human intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) arises from cholangiocytes in the intrahepatic bile duct and is the second most common type of liver cancer. The overexpression of COUP-TFII has been observed in several types of malignancies. However, its role in ICC progression remains unclear. In this study, we found that the protein level of COUP-TFII was increased, but the mRNA level was unchanged in ICC tissues. High protein expression was positively associated with tumor size, lymph node metastasis, and poor prognosis in ICC patients. Furthermore, the overexpression of COUP-TFII promoted the proliferation, migration, and invasion of ICC cells in vitro and enhanced tumor growth and metastasis in nude mouse models. Mechanistic studies revealed that COUP-TFII induced epithelial-to-mesenchymal transition in ICC cells by upregulating Snail expression. Moreover, the activation of PI3K/AKT signaling led to the upregulation of COUP-TFII protein expression in ICC. Together, these findings indicate that COUP-TFII promotes epithelial-to-mesenchymal transition and metastasis in ICC and suggest that this protein is a potential target for adjuvant therapy for these patients.

miRNA-129/FBW7/NF-κB, a Novel Regulatory Pathway in Inflammatory Bowel Disease.

F-box and WD repeat domain-containing protein 7 (FBW7) has been documented to be implicated in nuclear factor κB (NF-κB) signaling and inflammation, but its role in the pathogenesis of inflammatory bowel disease (IBD) remains unknown. FBW7 was increased both in colon tissues from IBD patients and trinitrobenzene sulphonic acid (TNBS)-induced colitis mice. Immunoprecipitation assay identified that FBW7 as a novel inhibitor of κBα (IκBα)-binding partner. FBW7 upregulation promoted IκBα ubiquitin-dependent degradation, NF-κB activation, and subsequent intestinal inflammation in intestinal epithelial cells, whereas inhibition of FBW7 produced the opposite effects. Computational analysis revealed that microRNA-129 (miR-129) directly targets at 3' UTR of FBW7. The miR-129-suppressed proteasome pathway mediated the degradation of IκBα by negatively regulating FBW7. The in vivo study demonstrated that upregulation of miR-129 ameliorated intestinal inflammation in TNBS-induced colitis mice through inhibition of the NF-κB signaling pathway. In conclusion, FBW7 is a novel E3 ubiquitin ligase for IκBα and thereby leads to NF-κB activation and inflammation. miR-129 negatively regulates FBW7 expression, resulting in secondary inhibition of the NF-κB pathway and amelioration of intestinal inflammation. Our findings provide new insight into the development of therapeutic strategies for the treatment of IBD.

KIFC1 regulated by miR-532-3p promotes epithelial-to-mesenchymal transition and metastasis of hepatocellular carcinoma via gankyrin/AKT signaling.

Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide. The poor survival may be due to a high proportions of tumor recurrence and metastasis. Kinesin family member C1 (KIFC1) is highly expressed in a variety of neoplasms and is a potential marker for non-small cell lung cancer or ovarian adenocarcinoma metastasis. Nevertheless, the role of KIFC1 in HCC metastasis remains obscure. We investigated this in the present study using HCC cell lines and clinical specimens. Our results indicated that increased levels of KIFC1 were associated with poor prognosis and metastasis in HCC. In addition, KIFC1 induced epithelial-to-mesenchymal transition (EMT) and HCC metastasis both in vitro and in vivo. This tumorigenic effect depended on gankyrin; inhibiting gankyrin activity reversed EMT via activation of protein kinase B (AKT)/Twist family BHLH transcription factor 1 (AKT/TWIST1). We also found that KIFC1 was directly regulated by the microRNA miR-532-3p, whose downregulation was associated with metastatic progression in HCC. These results denote that a decrease in miR-532-3p levels results in increased KIFC1 expression in HCC, leading to metastasis via activation of the gankyrin/AKT/TWIST1 signaling pathway.

Deregulated AJAP1/ß-catenin/ZEB1 signaling promotes hepatocellular carcinoma carcinogenesis and metastasis.

Adherens junctions-associated protein 1 (AJAP1) is an integral membrane protein that is thought to function as a tumor suppressor in various malignancies. Downregulation of AJAP1 mRNA levels may predict recurrence in hepatocellular carcinoma (HCC) patients, but the underlying molecular mechanism is unknown. This was addressed in the present study by examining the role of AJAP1 in HCC cell proliferation, migration, and invasion in vitro as well as in human specimens and mouse xenograft model. We found that AJAP1 expression was reduced in HCC cells and human HCC tissue, which was associated with metastasis. AJAP1 overexpression inhibited HCC progression and metastasis, while its silencing had the opposite effect both in vitro and in vivo. Furthermore, AJAP1 blocked epithelial-to-mesenchymal transition by interacting with ß-catenin and inhibiting its nuclear translocation, which suppressed zinc finger E-box binding homeobox 1 (ZEB1) transcription. These results indicate that AJAP1 inhibits HCC metastasis, and is thus a potential therapeutic target for HCC treatment.

Novel markers for circulating tumor stem cells in colorectal carcinoma.

Some colorectal carcinoma (CRC) invades into vessels and has distal metastasis, largely attributable to the dissemination of tumor cells into circulation as circulating tumor cells (CTCs). Moreover, cancer stem cells (CSCs) within CTCs, which are termed as circulating tumor stem-like cells (CTSCs), are critical for formation of distal metastatic tumors. Although different cell surface markers have been used to characterize and isolate CTCs or CSCs in CRC, no good marker has been identified so far for CTSCs. Here, we show evidence that CD262+ CRC cells appeared to be highly enriched for CTSCs in CRC. CD262+ CRC cells formed more tumor spheres in culture, exhibited higher chemo-resistance, had higher ratio of developing tumors after serial adoptive transplantation in nude mice, and had higher frequency of developing distal metastatic tumor, compared to traditional CD133+ or CD44+ CRC cells. Moreover, tumor cells were significantly more frequently detected in the circulation when CD262+ CRC cells were subcutaneously transplanted. Finally, we detected high CD262 levels in the stage IV CRC specimens, which were associated with poor prognosis of the patients. Together, these data suggest CD262+ may be a novel CTSC markers and selective elimination of CD262+ CRC cells may substantially improve the current CRC therapy.

(-)-Oleocanthal inhibits growth and metastasis by blocking activation of STAT3 in human hepatocellular carcinoma.

We explored the anti-cancer capacity of (-)-oleocanthal in human hepatocellular carcinoma (HCC). (-)-Oleocanthal inhibited proliferation and cell cycle progression and induced apoptosis in HCC cells in vitro and suppressed tumor growth in an orthotopic HCC model. (-)-Oleocanthal also inhibited HCC cell migration and invasion in vitro and impeded HCC metastasis in an in vivo lung metastasis model. ( )-Oleocanthal acted by inhibiting epithelial-mesenchymal transition (EMT) through downregulation Twist, which is a direct target of STAT3. (-)-Oleocanthal also reduced STAT3 nuclear translocation and DNA binding activity, ultimately downregulating its downstream effectors, including the cell cycle protein Cyclin D1, the anti-apoptotic proteins Bcl-2 and survivin, and the invasion-related protein MMP 2. Overexpression of constitutively active STAT3 partly reversed the anti cancer effects of (-)-oleocanthal, which inhibited STAT3 activation by decreasing the activities of JAK1 and JAK2 and increasing the activity of SHP-1. These data suggest that (-)-oleocanthal may be a promising candidate for HCC treatment.

Selecting molecular therapeutic drug targets based on the expression profiles of intrahepatic cholangiocarcinomas and miRNA-mRNA regulatory networks.

The incidence of intrahepatic cholangiocarcinoma (ICC) is increasing yearly, making it the second most common carcinoma after hepatocellular carcinoma among primary malignant liver tumors. Integrated miRNA and mRNA analysis is becoming more frequently used in antitumor ICC treatment. However, this approach generates vast amounts of data, which leads to difficulties performing comprehensive analyses to identify specific therapeutic drug targets. In this study, we provide an in-depth analysis of ICC function, identifying potential highly potent antitumor drugs for antitumor therapy. Two sets of whole genome expression profiles were obtained from the Gene Expression Omnibus (GEO) database. Using modular bioinformatic analysis, six core functional modules were identified for ICC. Based on a Fisher's test of the Cmap small molecule drug database, 65 drug components were identified that regulated the genes of these six core modules. Literature mining was then used to identify 15 new potential antitumor drugs.

YAP is a critical oncogene in human cholangiocarcinoma.

Yes-associated protein (YAP), a transcriptional co-activator, has important regulatory roles in cell signaling and is dysregulated in a number of cancers. However, the role of YAP in cholangiocarcinoma (CCA) progression remains unclear. Here, we demonstrated that YAP was overexpressed in CCA cells and human specimens. High levels of nuclear YAP (nYAP) correlated with histological differentiation, TNM stage, metastasis and poor prognosis in CCA. Silencing YAP increased tumor sensitivity to chemotherapy and inhibited CCA tumorigenesis and metastasis both in vivo and in vitro. YAP overexpression in vivo and in vitro promoted CCA tumorigenesis and metastasis. Additionally, we found that YAP induced epithelial-mesenchymal transition (EMT) and formed a regulatory circuit with miR-29c, IGF1, AKT and gankyrin to promote the progression of CCA. Results of CCA tissue microarray showed positive correlations between nYAP and gankyrin or p-AKT expression. Combination of nYAP and gankyrin or p-AKT exhibited improved prognostic accuracy for CCA patients. In conclusion, YAP promotes carcinogenesis and metastasis by up-regulating gankyrin through activation of the AKT pathway.

FTY720 inhibits proliferation and epithelial-mesenchymal transition in cholangiocarcinoma by inactivating STAT3 signaling.

BACKGROUND: Interleukin 6 (IL-6)-mediated signal transducers and activators of transcription 3 (STAT-3) phosphorylation (activation) is aberrantly sustained in cholangiocarcinoma cells resulting in enhanced myeloid cell leukemia 1 (Mcl-1) expression and resistance to apoptosis. FTY720, a new immunosuppressant, derived from ISP-1, has been studied for its putative anti-cancer properties. This study aimed to elucidate the mechanism by which FTY720 mediates antitumor effects in cholangiocarcinoma (CC) cells. METHODS: Three CC cell lines were examined, QBC939, TFK-1, and HuCCT1. The therapeutic effects of FTY720 were evaluated in vitro and in vivo. Cell proliferation, apoptosis, cell cycle, invasive potential, and epithelial- mesenchy-mal transition (EMT) were examined. RESULTS: FTY720 greatly inhibited CC cells proliferation and EMT in vitro and in vivo, and this effect was associated with dephosphorylation of STAT3tyr705. FTY720 induced apoptosis and G1 phase arrest in CC cells, and inhibited invasion of CC cells. Western blot analysis showed that FTY720 induced cleavage of caspases 3, 8 and 9, and of PARP, in a dose-dependent manner, consistent with a substantial decrease in p-STAT3, Bcl-xL, Bcl-2, survivin, cyclin D1, cyclin E, N-cadherin, vimentin, VEGF and TWIST1. In vivo studies showed that tumor growth and metastasis were significantly suppressed after FTY720 treatment. CONCLUSIONS: These results suggest that FTY720 induces a significant decrease in p-STAT3, which inhibits proliferation and EMT of CC cells, and then induces G1 phase arrest and apoptosis. We have characterized a novel immunosuppressant, which shows potential anti-tumor effects on CC via p-STAT3 inhibition. FTY720 merits further investigation and warrants clinical evaluation.

Reciprocal activation between ATPase inhibitory factor 1 and NF-κB drives hepatocellular carcinoma angiogenesis and metastasis.

UNLABELLED: Hepatocellular carcinoma (HCC) is a highly vascularized tumor with frequent extrahepatic metastasis. Active angiogenesis and metastasis are responsible for rapid recurrence and poor survival of HCC. However, the mechanisms that contribute to tumor metastasis remain unclear. Here we evaluate the effects of ATPase inhibitory factor 1 (IF1), an inhibitor of the mitochondrial H(+)-adenosine triphosphate (ATP) synthase, on HCC angiogenesis and metastasis. We found that increased expression of IF1 in human HCC predicts poor survival and disease recurrence after surgery. Patients with HCC who have large tumors, with vascular invasion and metastasis, expressed high levels of IF1. Invasive tumors overexpressing IF1 were featured by active epithelial-mesenchymal transition (EMT) and increased angiogenesis, whereas silencing IF1 expression attenuated EMT and invasion of HCC cells. Mechanistically, IF1 promoted Snai1 and vascular endothelial growth factor (VEGF) expression by way of activating nuclear factor kappa B (NF-κB) signaling, which depended on the binding of tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1) to NF-κB-inducing kinase (NIK) and the disruption of NIK association with the TRAF2-cIAP2 complex. Suppression of the NF-κB pathway interfered with IF1-mediated EMT and invasion. Chromatin immunoprecipitation assay showed that NF-κB can bind to the Snai1 promoter and trigger its transcription. IF1 was directly transcribed by NF-κB, thus forming a positive feedback signaling loop. There was a significant correlation between IF1 expression and pp65 levels in a cohort of HCC biopsies, and the combination of these two parameters was a more powerful predictor of poor prognosis. CONCLUSION: IF1 promotes HCC angiogenesis and metastasis by up-regulation of Snai1 and VEGF transcription, thereby providing new insight into HCC progression and IF1 function. (Hepatology 2014;60:1659-1673).

Gankyrin promotes tumor growth and metastasis through activation of IL-6/STAT3 signaling in human cholangiocarcinoma.

UNLABELLED: Although gankyrin is involved in the tumorigenicity and metastasis of some malignancies, the role of gankyrin in cholangiocarcinoma (CCA) is unclear. In this study we investigated the expression of gankyrin in human CCA tissues and cell lines. The effects of gankyrin on CCA tumor growth and metastasis were determined both in vivo and in vitro. The results showed that gankyrin was overexpressed in CCA tissues and cell lines. Gankyrin expression was associated with CCA histological differentiation, TNM stage, and metastasis. The multivariate Cox analysis revealed that gankyrin was an independent prognostic indicator for overall survival. Gankyrin overexpression promoted CCA cell proliferation, migration, and invasion, while gankyrin knockdown inhibited CCA tumor growth, metastasis, and induced Rb-dependent senescence and G1 phase cell cycle arrest. Gankyrin increased the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and promoted the nuclear translocation of p-STAT3. Suppression of STAT3 signaling by small interfering RNA (siRNA) or STAT3 inhibitor interfered with gankyrin-mediated carcinogenesis and metastasis, while interleukin (IL)-6, a known upstream activator of STAT3, could restore the proliferation and migration of gankyrin-silenced CCA cells. The IL-6 level was decreased by gankyrin knockdown, while increased by gankyrin overexpression. Gankyrin regulated IL-6 expression by way of facilitating the phosphorylation of Rb; meanwhile, rIL-6 treatment increased the expression of gankyrin, suggesting that IL-6 was regulated by a positive feedback loop involving gankyrin in CCA. In the xenograft experiments, gankyrin overexpression accelerated tumor formation and increased tumor weight, whereas gankyrin knockdown showed the opposite effects. The in vivo spontaneous metastasis assay revealed that gankyrin promoted CCA metastasis through IL-6/STAT3 signaling pathway. CONCLUSION: Gankyrin is crucial for CCA carcinogenesis and metastasis by activating IL-6/STAT3 signaling pathway through down-regulating Rb protein.

Hydroxytyrosol inhibits cholangiocarcinoma tumor growth: an in vivo and in vitro study.

Cholangiocarcinoma (CCA) is a type of digestive tumor that is associated with a high rate of mortality due to the difficulty of early diagnosis and the resistance of this tumor type to chemotherapy. Hydroxytyrosol (HT), which is derived from virgin olive oil (VOO), has recently been reported to inhibit the proliferation of various types of human cancer cells. In the present study, we investigated the effect of HT on CCA. The antiproliferative and proapoptotic effects of HT on CCA were evaluated in the human CCA cell lines TFK-1 and KMBC and the human gallbladder cancer cell line GBS-SD. We also assessed this effect in vivo. We found that 75 µM HT inhibited the proliferation of the TFK-1, KMBC and GBS-SD cell lines. However, 200 µM HT treatment did not affect the proliferation of the human bile duct cell line HIBEpiC. More importantly, HT (250 and 500 mg/kg/day) markedly inhibited the growth of CCA xenografts in mice. G2/M phase cell cycle arrest and apoptosis were observed using flow cytometry and western blotting, and we also noted a time- and dose-dependent inhibition of phospho-ERK, with no changes in total-ERK, during treatment with HT. The present study showed that HT induces cell cycle arrest and apoptosis in vitro and in vivo. These data suggest that HT, which possesses excellent biocompatibility and few side-effects, could be developed as a novel agent against CCA.