Invasion Of Intrahepatic Cholangiocarcinoma Cells Research Articles

Identification of RNF213 as a Potential Suppressor of Local Invasion in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a lethal cancer with poor survival especially when it spreads. The histopathology of its rare intraductal papillary neoplasm of the bile duct type (IPNB) characteristically shows cancer cells originating within the confined bile duct space. These cells eventually invade and infiltrate the nearby liver tissues, making it a good model to study the mechanism of local invasion, which is the earliest step of metastasis. To discover potential suppressor genes of local invasion in ICC, we analyzed the somatic mutation profiles and performed clonal evolution analyses of the 11 pairs of macrodissected locally invasive IPNB tissues (LI-IPNB) and IPNB tissues without local invasion from the same patients. We identified a protein-truncating variant in an E3 ubiquitin ligase, RNF213 (c.6967C>T; p.Gln2323X; chr17: 78,319,102 [hg19], exon 29), as the most common protein-truncating variant event in LI-IPNB samples (4/11 patients). Knockdown of RNF213 in HuCCT1 and YSCCC cells showed increased migration and invasion, and reduced vasculogenic mimicry but maintained normal proliferation. Transcriptomic analysis of the RNF213-knockdown vs control cells was then performed in the HuCCT1, YSCCC, and KKU-100 cells. Gene ontology enrichment analysis of the common differentially expressed genes revealed significantly altered cytokine and oxidoreductase-oxidizing metal ion activities, as confirmed by Western blotting. Gene Set Enrichment Analysis identified the most enriched pathways being oxidative phosphorylation, fatty acid metabolism, reactive oxygen species, adipogenesis, and angiogenesis. In sum, loss-of-function mutation of RNF213 is a common genetic alteration in LI-IPNB tissues. RNF213 knockdown leads to increased migration and invasion of ICC cells, potentially through malfunctions of the pathways related to inflammation and energy metabolisms.

THBS1 and THBS2 Enhance the In Vitro Proliferation, Adhesion, Migration and Invasion of Intrahepatic Cholangiocarcinoma Cells.

In intrahepatic cholangiocarcinoma (iCCA), thrombospondin 1 (THBS1) and 2 (THBS2) are soluble mediators released in the tumor microenvironment (TME) that contribute to the metastatic spreading of iCCA cells via a lymphatic network by the trans-differentiation of vascular endothelial cells to a lymphatic-like phenotype. To study the direct role of THBS1 and THBS2 on the iCCA cells, well-established epithelial (HuCCT-1) and mesenchymal (CCLP1) iCCA cell lines were subjected to recombinant human THBS1 and THBS2 (rhTHBS1, rhTHBS2) for cellular function assays. Cell growth, cell adhesion, migration, and invasion were all enhanced in both CCLP1 and HuCCT-1 cells by the treatment with either rhTHBS1 or rhTHBS2, although they showed some variability in their intensity of speeding up cellular processes. rhTHBS2 was more intense in inducing invasiveness and in committing the HuCCT-1 cells to a mesenchymal-like phenotype and was therefore a stronger enhancer of the malignant behavior of iCCA cells compared to rhTHBS1. Our data extend the role of THBS1 and THBS2, which are not only able to hinder the vascular network and promote tumor-associated lymphangiogenesis but also exacerbate the malignant behavior of the iCCA cells.

Identification of FOXP1 as a favorable prognostic biomarker and tumor suppressor in intrahepatic cholangiocarcinoma

BackgroundForkhead-box protein P1 (FOXP1) has been proposed to have both oncogenic and tumor-suppressive properties, depending on tumor heterogeneity. However, the role of FOXP1 in intrahepatic cholangiocarcinoma (ICC) has not been previously reported.MethodsImmunohistochemistry was performed to detect FOXP1 expression in ICC and normal liver tissues. The relationship between FOXP1 levels and the clinicopathological characteristics of patients with ICC was evaluated. Finally, in vitro and in vivo experiments were conducted to examine the regulatory role of FOXP1 in ICC cells.ResultsFOXP1 was significantly downregulated in the ICC compared to their peritumoral tissues (p < 0.01). The positive rates of FOXP1 were significantly lower in patients with poor differentiation, lymph node metastasis, invasion into surrounding organs, and advanced stages (p < 0.05). Notably, patients with FOXP1 positivity had better outcomes (overall survival) than those with FOXP1 negativity (p < 0.05), as revealed by Kaplan–Meier survival analysis. Moreover, Cox multivariate analysis showed that negative FOXP1 expression, advanced TNM stages, invasion, and lymph node metastasis were independent prognostic risk factors in patients with ICC. Lastly, overexpression of FOXP1 inhibited the proliferation, migration, and invasion of ICC cells and promoted apoptosis, whereas knockdown of FOXP1 had the opposite role.ConclusionOur findings suggest that FOXP1 may serve as a novel outcome predictor for ICC as well as a tumor suppressor that may contribute to cancer treatment.

Integrin β5 is an independent prognostic marker for intrahepatic cholangiocarcinoma in a Chinese population.

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver tumor and a major cause of cancer mortality worldwide. Integrin β5 (ITGB5) is considered to be involved in the intercellular signal transduction and regulation of tumorigenesis and development. The present study investigated the association between ITGB5 expression levels and the prognosis of ICC, as well as the effects of ITGB5 on the proliferation and invasion of ICC cells. RNA-sequencing transcriptomic profiling data of ICC samples were retrieved from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Tissue specimens from patients with ICC treated at Taizhou People's Hospital were collected and the ITGB5 expression levels were evaluated using immunohistochemical staining. The biological function of ITGB5 in ICC was investigated using Gene Ontology (GO), Gene Set Enrichment Analysis (GSEA) and in vitro experiments using HuCCT1 cells. After knocking down ITGB5 expression, cell proliferation was detected using Cell Counting Kit-8 assay, while cell invasion was assessed using Transwell assays. According to TCGA dataset, ITGB5 was highly expressed in ICC; however, there was no significant difference in prognosis between patients with high and low ITGB5 expression levels. High expression of ITGB5 was present in the tissues of patients with ICC from the GEO database, which was associated with poor prognosis. Survival analyses of the clinical data obtained in the present study revealed that high expression levels of ITGB5 in patients with ICC were associated with a reduced overall survival. GO and GSEA indicated that genes associated with ITGB5 were enriched in the extracellular matrix-receptor interaction and focal adhesion signaling pathways. Silencing ITGB5 inhibited the proliferation and invasion of ICC cells. In conclusion, ITGB5 may act as an essential regulator of ICC development and progression by influencing the proliferation and invasion of ICC cells. However, future studies with larger sample sizes are required to validate the role of ITGB5 in the prognosis of patients with ICC.

Aquaporin 1 is a prognostic marker and inhibits tumour progression through downregulation of Snail expression in intrahepatic cholangiocarcinoma.

Recently, some studies have suggested a link between AQP1 and cancer progression. The aim of the present study was to investigate the influence of AQP1 on the clinicopathology and prognosis of intrahepatic cholangiocarcinoma (ICC) patients. We retrospectively detected the expression of AQP1 protein in 307 patients with ICC who underwent partial hepatectomy. Western blot analysis was used to detect AQP1 protein levels in stable AQP1 overexpression and knockdown cell lines. The influence of AQP1 on the invasion and metastasis ability of ICC cells was assessed by wound-healing and Transwell assays in vitro as well as by a splenic liver metastasis model in vivo. Positive membranous AQP1 expression was identified in 34.2% (105/307) of the ICC specimens. Survival data revealed that positive AQP1 expression was significantly associated with favourable disease-free survival (DFS) and overall survival (OS) (p=0.0290 and p=0003, respectively). Moreover, high AQP1 expression inhibited the invasion and migration of ICC cells in vitro as well as inhibited liver metastasis in nude mice. Mechanistically, high AQP1 expression in ICC cells increased the levels of E-cadherin but decreased the levels of the Snail transcription factor. AQP1 expression is associated with a favourable prognosis in ICC patients. AQP1 inhibits ICC cell invasion, metastasis, and epithelial-mesenchymal transition (EMT) through downregulation of Snail expression.

Quercetin Inhibits Intrahepatic Cholangiocarcinoma by Inducing Ferroptosis and Inhibiting Invasion via the NF-[Formula: see text]B Pathway.

Intrahepatic cholangiocarcinoma (ICC) is a rare, highly fatal hepatobiliary malignancy, with very limited treatment options and, consequently, a poor prognosis. Recently, emerging evidence has suggested the potential of quercetin (QE) for use in cancer therapy. The purpose of this study is to investigate whether QE could inhibit ICC. The effects of QE on the proliferation, apoptosis, and invasion of ICC were analyzed in vitro. The inhibitory effect of QE on ICC was also verified in vivo. The RNA sequence was applied to explore the mechanism of QE. Functional verification was also performed after RNA sequencing using activators and inhibitors of nuclear factor-kappa-B (NF-[Formula: see text]B) and ferroptosis. The results showed that QE could inhibit the proliferation and survival of ICC cells, induce the arrest of ICC cells in the G1 phase, promote the apoptosis of ICC cells, and inhibit the invasion of ICC cells. Furthermore, QE could promote ferroptosis in ICC cells by inhibiting the NF-[Formula: see text]B pathway. In conclusion, QE is a new ferroptosis inducer and NF-[Formula: see text]B inhibitor that can not only induce ferroptosis, but also inhibit the invasion of ICC cells, providing a prospective strategy for the treatment of ICC.

Glycoproteomic analysis reveals the effects of bisecting GlcNAc in intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (ICC) is the second major subtype of primary liver cancer and has caused more and more attention with increasing incidence and mortality worldwide. Our previous study found that bisecting N-glycans are commonly increased in ICC, while the effects and potential functions of bisecting GlcNAc in ICC are still largely unclear. In this study, we further confirmed that the structures of bisecting GlcNAc were significantly up-regulated in ICC compared with paracancer tissues by glycoproteomic data and lectin histochemistry. The expression of its glycosyltransferase MGAT3 was also up-regulated in ICC tissues at both mRNA and protein levels, and expression of MGAT3 is negatively correlated with overall survival explored by bioinformatic analyses and published datasets from 255 patients. Next, the silencing of MGAT3 could inhibit the growth and invasion of ICC cells, and overexpressing of MGAT3 only promoted ICC cell invasion. Further glycoproteomic analysis showed that the commonly glycoproteins modified by bisecting GlcNAc after MGAT3-overexpression in two ICC cell lines were mainly involved in cell movement-related biological processes, such as cell adhesion, integrin-related and ECM-receptor interaction. This study sheds light on the potential effects of bisecting GlcNAc in ICC cells and suggests that MGAT3 might be used as a potential target in the therapy of ICC.

EIF5A2 promotes proliferation and invasion of intrahepatic cholangiocarcinoma cells

PurposeIntrahepatic cholangiocarcinoma (ICC) can invade and metastasize. EIF5A2 is involved in the invasive metastatic process of several digestive malignancies. However, its role in ICC is yet to be elucidated. MethodsImmunohistochemistry (IHC) and Western blot (WB) were used to detect the level of EIF5A2 in the tumor specimens of ICC patients and evaluate the correlation between its expression and clinicopathological characteristics. The significance of EIF5A2 in the prognosis of ICC patients was further evaluated by Kaplan–Meier and Cox regression analysis. In addition, CCK-8, EdU, Transwell invasion, and scratch assays were utilized to detect tumor cell proliferation, invasion, and metastasis. Furthermore, the role of EIF5A2 in ICC cells was evaluated after modification of EIF5A2 expression. ResultsThe level of EIF5A2 protein was significantly higher in ICC than in adjacent tissues. This high expression in the tumor samples was significantly associated with malignant phenotypes, such as lymph node metastasis (LNM), microvascular or bile duct invasion, and poor differentiation. ICC patients with high expression of EIF5A2 had short overall survival and a high cumulative recurrence rate. The multifactorial analysis showed that EIF5A2 is an independent prognostic marker. Furthermore, high levels of EIF5A2 may activate the PI3K/AKT/mTOR signaling pathway and upregulate Cyclin D1, Cyclin D3, MMP2, and MMP9 to promote ICC cell proliferation, migration, and invasion. ConclusionThe current study found that EIF5A2 promotes ICC progression and is a prognostic biomarker and candidate therapeutic target for ICC patients.

Chemokine (C-C motif) ligand 18/membrane-associated 3/forkhead box O1 axis promotes the proliferation, migration, and invasion of intrahepatic cholangiocarcinoma

ABSTRACT Phosphatidylinositol Transfer Protein, Membrane-Associated 3 (PITPNM3) often bind with chemokine (C-C motif) ligand 18 (CCL18) to promote tumor progression. However, the role of PITPNM3 in intrahepatic cholangiocarcinoma (ICC) is unclear. We first searched GEPIA database and detected the PITPNM3 expression using immunohistochemistry and real-time quantitative PCR. The results showed that PITPNM3 is high expression in ICC tissues and cells. Then we investigated the cell function of CLL18 and PITPNM3 through cell clone formation assay and transwell assay. The results indicated that CCL18 treatment promoted the proliferation, migration, and invasion of ICC cells. Silence of PITPNM3 reversed the effect of CCL18 on cell function. Simultaneously, we detected key protein expression of forkhead box O1 (FOXO1) and nuclear factor kappa B (NF-KB) through western blotting and found that CCL18 activated NF-KB pathway while inhibited FOXO1 pathway, the effect of which were attenuated by silence of PITPNM3. Finally, we confirmed which pathway affected the cell function using inhibitor of FOXO1 (AS1842856) and activator of NF-KB (Asatone). The results showed that AS1842856, not Asatone, relieved the inhibitory effect of si-PITPNM3 on the cell function of CCL18. In short, CCL18 treatment activated PITPNM3 to promote the proliferation, migration, and invasion of ICC via FOXO1 signaling pathway. These results provided a new insight for the diagnosis and therapy of ICC.

CircHMGCS1\u2013016 reshapes immune environment by sponging miR-1236-3p to regulate CD73 and GAL-8 expression in intrahepatic cholangiocarcinoma

BackgroundAccumulating evidence indicates that circRNAs may serve as essential regulators in the progression of several human cancers, but the function and mechanism of circRNAs in intrahepatic cholangiocarcinoma (ICC) are largely unknown.MethodsRNA-seq was used to assess differentially expressed circRNAs between 4 ICC and peritumor tissues. Quantitative RT-PCR and in situ hybridization were used to determine the circHMGCS1–016 expression in ICC tissues. The function and mechanism of circHMGCS1–016 were further identified via in vivo experiments. The clinical characteristics and prognostic significance of circHMGCS1–016 were analyzed by a retrospective study. The functions of circHMGCS1–016 were assessed via modifying circRNA expression in ICC cells. Moreover, the molecular mechanisms of circHMGCS1–016 in ICC cells were explored by circRNA precipitation, miRNA immunoprecipitation, SILAC and luciferase reporter assays.ResultsWe identified that compared with peritumor tissues, ICC tissues expressed hsa_circ_0008621 (circHMGCS1–016) high by RNA-seq, which was further identified by qRT-PCR and in situ hybridization. Moreover, the expression of circHMGCS1–016 was revealed to be associated with survival and recurrence of ICC patients. By regulating circHMGCS1–016 expression, we found that elevated circHMGCS1–016 promoted ICC development both in vitro and in vivo. By SILAC and circRNA-pull down, we demonstrated that circHMGCS1–016 induced ICC cell invasion and reshaped the tumor immune microenvironment via the miR-1236-3p/CD73 and GAL-8 axis. In ICC tissues, we uncovered that a high level of circHMGCS1–016 was positively associated with CD73 and GAL-8 expression and negatively related to the CD8+ T cells infiltration, which was further validated by establishing a humanized mouse tumor model. Importantly, we displayed that ICC patients with high levels of circHMGCS1–016 in tumor tissues benefited less from anti-PD1 treatment compared to those with low levels of circHMGCS1–016.ConclusionsCircHMGCS1–016 is a forceful contributor in ICC development and immune tolerance via miR-1236-3p/CD73 and GAL-8 axis. CircHMGCS1–016 can be explored as a new potential biomarker and therapeutic target for PD1-resistant ICC.

Long Non-coding RNA SNHG12, a New Therapeutic Target, Regulates miR-199a-5p/Klotho to Promote the Growth and Metastasis of Intrahepatic Cholangiocarcinoma Cells.

Background: Small nucleolar RNA host gene 12 (SNHG12) is a newly identified long non-coding RNA (lncRNA) whose involvements have been explored in several cancers. Our study aimed to explore the functions of SNHG12 on intrahepatic cholangiocarcinoma (ICC) progression and its interaction with miR-199a-5p and Klotho.Methods: RT-PCR was performed to examine the expressions of SNHG12, miR-199a-5p and Klotho in ICC cells. Cell counting kit-8 (CCK-8), colony formation assays and transwell assays were applied to analyze the proliferation, migration and invasion of ICC cells. Luciferase assays, RIP assays and RNA pull-down assays were carried out to demonstrate the direct binding relationships among SNHG12, miR-199a-5p and Klotho. The xenograft nude models were applied to test the effects of SNHG12 on ICC tumor growth.Results: The expression of SNHG12 and Klotho was distinctly increased in ICC cells, while miR-199a-5p expressions were decreased. Functionally, the silence of SNHG12 inhibited the proliferation and metastasis of ICC cells, while miR-199a-5p overexpression exhibited an opposite result. Mechanistically, Knockdown of SNHG12 significantly suppressed the expressions of miR-199a-5p by sponging it, and then increased Klotho expression. The final in vivo experiments suggested that the silence of SNHG12 distinctly inhibited tumor growth.Conclusion: Our findings indicated that SNHG12 inhibited cell proliferation and metastasis process of ICC cells through modulating the miR-199a-5p/Klotho axis and it is expected to become a potential therapeutic target for ICC.

Long Non-Coding RNA-PAICC Promotes the Tumorigenesis ofHuman Intrahepatic Cholangiocarcinoma byIncreasing YAP1 Transcription.

Intrahepatic cholangiocarcinoma (ICC) is a heterogeneous hepatobiliary tumor with poor prognosis, and it lacks reliable prognostic biomarkers and effective therapeutic targets. Long non-coding RNAs (lncRNAs) have been documented to be involved in the progression of various cancers. However, the role of lncRNAs in ICC remains largely unknown. In the present work, we used bioinformatics analysis to identify the differentially expressed lncRNAs in human ICC tissues, among which lncRNA-PAICC was found to be an independent prognostic marker in ICC. Moreover, lncRNA-PAICC promoted the proliferation and invasion of ICC cells. Mechanistically, lncRNA-PAICC acted as a competitive endogenous RNA (ceRNA) that directly sponged the tumor suppressive microRNAs miR-141-3p and miR-27a-3p. The competitive binding property was essential for lncRNA-PAICC to promote tumor growth and metastasis through activating the Hippo pathway. In summary, our results highlighted the important role of the lncRNA-PAICC-miR-141-3p/27a-3p-Yap1 axis in ICC, which offers a novel perspective on the molecular pathogenesis and may serve as a potential target for antimetastatic molecular therapies of ICC.

Oxaliplatin reverses the GLP-1R-mediated promotion of intrahepatic cholangiocarcinoma by altering FoxO1 signaling.

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer, with a 5-year survival rate of <10%; effective drug treatment for ICC is currently lacking. Glucagon-like peptide-1 receptor (GLP-1R) is upregulated in ICC; however, the functions of GLP-1R in ICC remain unknown. In this study, the upregulation of GLP-1R was confirmed in ICC cells using reverse transcription-quantitative polymerase chain reaction and western blot analysis, and GLP-1R was determined to promote the migration and invasion of ICC cells using Transwell assays. This tumor-promoting effect depended on the upregulation of epithelial-mesenchymal transformation-associated proteins, which was mediated by the FoxO1 signaling pathway. It was also indicated that following oxaliplatin treatment, the effects of GLP-1R on EMT and invasion were reversed. This functional reversion was associated with the reduced phosphorylation of S256 in forkhead box O1 (FoxO1) and an increase in the levels of unphosphorylated FoxO1. These findings suggest that incretin-based therapies may increase the risk of ICC metastasis and should not be used solely for the treatment of patients with ICC.

Long non-coding RNA UCA1 promotes proliferation and invasion of intrahepatic cholangiocarcinoma cells through targeting microRNA-122.

Long non-coding RNA urothelial carcinoma-associated 1 (UCA1) has a role in various common types of human malignancy, including cholangiocarcinoma; however, the expression and function of UCA1 in intrahepatic cholangiocarcinoma (ICC) has remained elusive. In the present study, it was observed that UCA1 expression was significantly upregulated in ICC tissues and cell lines compared with that in the adjacent non-tumour tissues and a human intrahepatic biliary epithelial cell line, respectively. The increased expression of UCA1 was significantly associated with lymph node metastasis and clinical T-stage in ICC. Furthermore, the ICC patients with high expression of UCA1 had a shorter survival time when compared with that of patients with low UCA1 expression. Knockdown of UCA1 caused a significant decrease in ICC cell proliferation and invasion, while ectopic overexpression of UCA1 significantly promoted the proliferation and invasion of ICC cells. Furthermore, it was revealed that UCA1 directly binds to microRNA (miR)-122 to negatively regulate its expression in ICC cells. In addition, miR-122 mimics abrogated the promoting effects of UCA1 on ICC cell proliferation and invasion. In addition, an inverse correlation between miR-122 and UCA1 expression in ICC tissues was observed. In conclusion, the present study demonstrates that the lncRNA UCA1 promotes ICC cell proliferation and invasion at least in part by targeting miR-122, suggesting that the UCA1/miR-122 interaction may become a potential therapeutic target for the treatment of ICC.

SRC-like adaptor protein negatively regulates Wnt signaling in intrahepatic cholangiocarcinoma.

Currently, the molecular mechanisms underlying intrahepatic cholangiocarcinoma (IHCC) are poorly understood. In the present study, the focus was primarily on SRC-like adaptor protein (SLAP), an adaptor protein, which is aberrantly expressed in various cancer types. To the best of our knowledge, the present study was the first to demonstrate that SLAP was decreased in IHCC tissues and cells, compared with controls. Further study indicated that SLAP overexpression suppressed IHCC cell proliferation and induced cell cycle arrest, indicating the tumor suppressor role of SLAP in IHCC progression. To demonstrate the effects of SLAP on Wnt signaling, the β-catenin/T cell factor transcription reporter assay was conducted. Compared with the negative adenovirus vector control (Ad-NC), overexpression of SLAP reduced TOPflash activity, and no changes in FOPflash activity were identified. Furthermore, the expression levels of Wnt target genes, including β-catenin, c-Myc, cluster of differentiation 44, Slug, Vimentin and matrix metallopeptidase-9, were reduced in RBE and Huh28 cells overexpressing SLAP. Additionally, the effects of SLAP on IHCC cell invasion and migration were determined. Compared with the Ad-NC control, the migration and invasion capacity was reduced following overexpression of SLAP in RBE and Huh28 cells. In summary, reduced SLAP expression may enhance IHCC malignant progression by activating Wnt signaling.

Role of the overexpression of TRAF4 in predictingthe prognosis of intrahepatic cholangiocarcinoma

The incidence of intrahepatic cholangiocarcinoma(ICC) is progressively increasing worldwide, and its prognosis remains poor. Accumulating evidence has demonstrated that tumor necrosis factor receptor-associated factor4 (TRAF4), an adaptor protein, is involved in the carcinogenesis and progression of several tumor types. However, the function of TRAF4 in predicting prognosis, and mediating migration and invasion of ICC remains to be elucidated. In the present study, immunohistochemistry, western blotting and reverse transcription-quantitative polymerase chain reaction assays were used to determine that the expression of TRAF4 at the mRNA and protein levels in ICC tissues was significantly higher compared with that in non‑tumor tissues. The overexpression of TRAF4 was positively correlated with poor differentiation, regional lymphatic metastasis, and high tumor‑node-metastasis staging. Inhibiting the expression of TRAF4 using small interfering RNA decreased the migration and invasion of ICC cells invitro. In addition, the AKT inhibitor perifosine eliminated the effect of TRAF4 on the invasion and migration of ICC cells invitro. Clinically, the overexpression of TRAF4 was correlated with shorter overall survival rate and elevated recurrence rate in patients with ICC. Furthermore, patients with ICC with a high expression of TRAF4 and lymphatic metastasis were closely associated with a poorer prognosis compared with the other groups. Multivariate analysis indicated that the overexpression of TRAF4 was an independent prognostic indicator for patients with ICC. It was identified that a high level of TRAF4 facilitated the invasiveness of ICC cells via the activation of AKT signaling. The overexpression of TRAF4 may be a prognostic biomarker and candidate therapeutic target for patients with ICC.

MicroRNA-26b-5p regulates cell proliferation, invasion and metastasis in human intrahepatic cholangiocarcinoma by targeting S100A7.

The present study aimed to investigate the effects of microRNA expression in intrahepatic cholangiocarcinoma (ICC). It was identified that the expression of microRNA-26b-5p (miR-26b-5p) was downregulated in ICC tissues compared with matched adjacent non-tumor tissues. Furthermore, miR-26b-5p expression was downregulated in metastatic ICC tumor tissues and invasive ICC cell line subpopulations compared with non-metastatic tumor tissue and the parental ICC cells. In vitro studies demonstrated that transfection with an miR-26b-5p mimic inhibited the proliferation, migration and invasion of RBE and HCCC-9810 cells, whereas an miR-26b-5p inhibitor promoted these abilities. S100 calcium-binding protein A7 (S100A7) was predicted as a direct target of miR-26b-5p. Transfection with an miR-26b-5p mimic decreased S100A7 expression, whereas an miR-26b-5p inhibitor increased S100A7 expression. The result of a dual luciferase reporter assay also indicated this interaction. S100A7 was therefore confirmed as a direct target of miR-26b-5p in ICC. The knockdown of S100A7 abrogated the effect of miR-26b-5p on cell migration in RBE and HCCC-9810 cells. In conclusion, the present study demonstrated that miR-26b-5p suppresses the proliferation, migration and invasion of ICC cells by suppressing S100A7.

LncRNA-CCAT1 Promotes Migration, Invasion, and EMT in Intrahepatic Cholangiocarcinoma Through Suppressing miR-152.

Increasing evidence has suggested that lncRNA CCAT1 is upregulated and functions as a potential tumor promoter in many cancers. However, the potential biological roles and regulatory mechanisms of CCAT1 in intrahepatic cholangiocarcinoma (ICC) remain unclear. We used real-time PCR to measure CCAT1 expression in ICC tissues and the adjacent normal tissues. The statistical analyses were applied to evaluate the prognostic value and associations of CCAT1 expression with clinical parameters. The CCAT1 was silenced with siRNA in ICC cells. The migration and invasion of ICC cells were detected with Transwell assay. The expressions of epithelial-mesenchymal transition (EMT)-related proteins were evaluated to discover whether the process of EMT was involved. We found that CCAT1 expression was elevated in ICC tissues compared to the adjacent normal tissues. We also found that high CCAT1 expression is closely correlated with tumor progression in ICC patients. Furthermore, our results show that knockdown of CCAT1 significantly suppressed the migration and invasion of ICC cells. Additionally, CCAT1 silencing remarkably reverses the EMT phenotype of ICC cells. Moreover, bioinformatics analysis and luciferase reporter assay revealed that CCAT1 directly bound to the miR-152, which has been reported to serve as a tumor suppressor in variety cancers. Further investigation demonstrated that CCAT1 led to the metastasis and EMT activation of ICC cells through inhibiting miR-152. Our results suggested that CCAT1 functions as an oncogenic lncRNA in ICC, which could serve as a potential diagnostic and therapeutic target for ICC patients.

Abstract 5538: Functional analysis of BAP1, de-ubiquitination enzyme, in intrahepatic cholangiocarcinoma

Abstract BACKGROUND: BRCA associated protein 1 (BAP1) was discovered as a protein associated with the breast cancer susceptibility gene (BRCA), and genetic mutations of BAP1 gene have recently been found in some malignant tumors, such as melanoma, mesothelioma, and renal cell carcinoma. Since the mutations of BAP1 gene resulted in loss of function of this protein and were associated with poor prognoses of the malignancies, BAP1 is now considered as a tumor-suppressor gene. Recent studies have shown that BAP1 mutations were also observed in patients with intrahepatic cholangiocarcinoma (IHCC), which is one of the most aggressive carcinoma with poor prognoses. However, only a few studies have investigated the role of BAP1 mutation on biological function of tumor cells and on clinicopathological features of IHCC. PURPOSE: The purpose of this study was to elucidate the association of BAP1 and IHCC. METHOD: The expression of BAP1 was immunohistochemically analyzed in surgically resected IHCC specimens, and the cases were classified into three groups based on the result of immunostaining concentration; positive or weakly positive or negative. The clinicopathological factors, such as the disease stage of IHCC, curability and overall survival (OS), were compared among the groups. In cell culture analyses, the expression of BAP1 in IHCC cell lines (HuCC-T1 and TFK-1) was down-regulated by Zinc-finger nuclease (ZFN) and siRNA in vitro. Then, cell-proliferation assay, migration assay, invasion assay, and drug-susceptibility test were performed on BAP1 down-regulated cells. RESULTS: The immunohistochemistry of BAP1 on IHCC specimens showed that OS was not significantly changed among three groups. However, the cases with lower expression of BAP1 including weakly positive and negative tended to be advanced in disease stage compared with cases with BAP1 positive. Interestingly, in the patients received postoperative gemcitabine, a standard chemo-drug for cholangiocarcinoma, cases with lower expression of BAP1 showed prolonged survival compared with cases with BAP1 positive. In cell experiments, the knock-down of BAP1 did not affect cell-proliferation of IHCC cells, however, it promoted migration and invasion of IHCC cells. Furthermore, the suppression of BAP1 enhanced chemosensitivity to gemcitabine. CONCLUSIONS: Our study suggested that lower expression of BAP1 was associates with the progression of IHCC and with enhanced chemosensitivity to gemcitabine. BAP1 might be one of the target genes in the treatment of IHCC. Citation Format: Kentaro Ishii, Masaharu Ishida, Shinobu Ohnuma, Katsuyoshi Kudoh, Fuyuhiko Motoi, Takeshi Naitoh, Florin Selaru, Michiaki Unno. Functional analysis of BAP1, de-ubiquitination enzyme, in intrahepatic cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5538. doi:10.1158/1538-7445.AM2017-5538

Mortalin promotes cell proliferation and epithelial mesenchymal transition of intrahepatic cholangiocarcinoma cells in vitro

AimsThe prognosis of patients with intrahepatic cholangiocarcinoma (ICC) remains poor in terms of overall survival (OS) and recurrence rate. Mortalin, a stress chaperone, has been reported to be involved in...