RBE Cells Research Articles

CARD9 promotes cholangiocarcinoma by regulating the IL-17A/Hedgehog and the THEM4/AKT/mTOR signaling pathways

Cholangiocarcinoma (CCA) is a highly lethal malignant tumor originating from the bile duct, and its underlying mechanisms are not fully understood. In order to identify key genes in CCA, we downloaded gene expression data from public GSE76297, GSE26566 and TCGA-CHOL datasets. CARD9 was selected as a CCA-related gene from the datasets. Its expression was identified in the CCA tissues via PCR, western blot and immunohistochemistry assays. The loss-and-gain function assay of CARD9 was conducted in CCA cell lines (QBC939 and RBE) and nude mice. This study found a significant upregulation of CARD9 in CCA tissues, which is associated with poor prognosis in patients. Overexpression of CARD9 promotes proliferation and invasion of QBC939 and RBE cells, enhances the growth and development in CCA mouse models, and reduces sensitivity to chemotherapy drugs for CCA. Mechanistically, CARD9 activates the NF-κB and NLRP3 inflammatory signaling pathways, induces excessive release of various inflammatory factors, and triggers a cascade reaction of interleukin-17 (IL-17A). IL-17A promotes the stability of IHH mRNA by regulating HuR, enhances IHH transcription, and activates the Hedgehog signaling pathway to accelerate the progression of CCA. In addition, CARD9 promotes proliferation and invasion of CCA cells by interacting with THEM4, thereby facilitating AKT and mTOR phosphorylation, and accelerating the progression of CCA. Overall, these data suggest that CARD9 is involved in the progression of CCA by regulating the IL-17A/Hedgehog and the THEM4/AKT/mTOR signaling pathways. Therefore, CARD9 may serve as a novel therapeutic target for CCA treatment.

Hypocrellin A against intrahepatic Cholangiocarcinoma via multi-target inhibition of the PI3K-AKT-mTOR, MAPK, and STAT3 signaling pathways

BackgroundIntrahepatic cholangiocarcinoma (ICC) is an aggressive and highly lethal cancer with an increasing incidence worldwide that lacks effective treatment regimens. Hypocrellin A (HA), a natural small compound isolated from S. bambusicola, has multiple biomedical activities, including antitumor activity. PurposeWe intended to investigate the therapeutic effects of HA on ICC and its potential mechanisms. MethodsRBE and HuccT1 cell lines were utilized for in vitro experiments. CCK8 assay, colony formation analysis, RTCA, and immunofluorescence staining of ki67 were employed to evaluate the suppression effects of HA on proliferation. The inhibitory effects of HA on cell migration and invasion were evaluate through transwell and wound healing assays, and Hoechst 33,258 staining was performed to evaluate apoptosis. Additionally, we performed transcriptome sequencing and molecular docking for targeting identification, and immunoblotting and immunofluorescence of key molecules for validation. Two in vivo models, HuccT1 xenografts, and the primary ICC model (KRAS/P19/SB) established via hydrodynamic tail-vein injection were implemented. Multiplex immunohistochemistry (mIHC) was used to illustrate the multi-target inhibitory effects of HA. ResultsThe IC50 values of HA against RBE and HuccT1 cells were 4.612 μM and 10.01 μM for 24 h, as determined through the CCK8 assay. Our results confirmed that HA significantly repressed the proliferation, migration, invasion, and promoted the apoptosis of ICC cells at low concentrations. Moreover, HA exerted its anti-cancer effects through multi-target inhibition of the PI3K-AKT-mTOR, MAPK, and STAT3 signaling pathways. This inhibitory effect was rescued by Recilisib, an activator of the PI3K-AKT-mTOR pathway. Bioinformatics analysis of a multi-center RNA-Seq cohort (n = 90) demonstrated significant associations between these target pathways and the occurrence and poor prognosis of ICC. Animal studies suggested that HA strongly inhibited tumor growth in xenograft ICC models, and repressed the tumor number and size in the liver of primary ICC models by suppressing these three crucial pathways. ConclusionHA, a novel natural small molecule, demonstrated promising therapeutic efficacy against ICC through its multi-target inhibitory effects on the PI3K-AKT-mTOR, MAPK, and STAT3 signaling pathways. Moreover, it exhibited notable therapeutic benefits in a primary ICC model (KRAS/P19/SB), positioning it as a novel therapeutic agent for ICC.

Discovery of Aloperine as a Potential Antineoplastic Agent for Cholangiocarcinoma Harboring Mutant IDH1.

Intrahepatic cholangiocarcinoma (ICC) is a universally lethal malignancy with increasing incidence. However, ICC patients receive limited benefits from current drugs; therefore, we must urgently explore new drugs for treating ICC. Quinolizidine alkaloids, as essential active ingredients extracted from Sophora alopecuroides Linn, can suppress cancer cell growth via numerous mechanisms and have therapeutic effects on liver-related diseases. However, the impact of quinolizidine alkaloids on intrahepatic cholangiocarcinoma has not been fully studied. In this article, the in vitro anti-ICC activities of six natural quinolizidine alkaloids were explored. Aloperine was the most potent antitumor compound among the tested quinolizidine alkaloids, and it preferentially inhibited RBE cells rather than HCCC-9810 cells. Mechanistically, aloperine can potentially decrease glutamate content by inhibiting the hydrolysis of glutamine, reducing D-2-hydroxyglutarate levels and, consequently, leading to preferential growth inhibition in isocitrate dehydrogenase (IDH)-mutant ICC cells. In addition, aloperine preferentially resensitizes RBE cells to 5-fluorouracil, AGI-5198 and olaparib. This article demonstrates that aloperine shows preferential antitumor effects in intrahepatic cholangiocarcinoma cells harboring the mutant IDH1 by decreasing D-2-hydroxyglutarate, suggesting that aloperine could be used as a lead compound or adjuvant chemotherapy drug to treat ICC harboring the mutant IDH.

CREB1 promotes cholangiocarcinoma metastasis through transcriptional regulation of the LAYN-mediated TLN1/β1 integrin axis: CREB1 promotes cholangiocarcinoma metastasis through regulating LAYN/TLN1/β1 integrin axis

BackgroundLayilin (LAYN) plays an important role in tumor progression, invasion, and metastasis; however, its role in cholangiocarcinoma (CHOL) has not been elucidated. MethodsWe utilized the GEPIA, STRING, and hTFtarget databases for bioinformatics analysis. Overexpression or knockdown cell lines were constructed by transfecting the cells with different plasmids. Western blot (WB) was performed to detect LAYN, TLN1, and CREB1 expression. Cell proliferation, migration, and invasiveness were assessed using CCK-8 and Transwell assays. Immunofluorescence and WB were used to detect epithelial-mesenchymal transition (EMT) markers. The CHOL metastasis model was established by injecting RBE cells into the tail veins of nude mice. Metastatic lesions were identified using hematoxylin and eosin staining. Co-immunoprecipitation and Chromatin immunoprecipitation were used to validate the interactions. ResultsLAYN was highly expressed in the CHOL cells. Knockdown of LAYN significantly inhibited proliferation, migration, invasion, and EMT in both QBC-939 and RBE human CHOL cells, while overexpression of LAYN had the opposite effect. Furthermore, in a CHOL metastasis model using nude mice, knocking down LAYN expression markedly suppressed CHOL liver and lung metastases. LAYN interacts with TLN1, and CREB1 binds to the LAYN promoter, with all three showing a positive correlation. Additionally, bioinformatics analysis revealed high expression of both TLN1 and CREB1 in CHOL. Knockdown of TLN1 or CREB1 in QBC-939 and RBE cells inhibited cell proliferation, migration, invasion, and EMT, reversing the effects of LAYN overexpression. Moreover, knockdown of TLN1 or CREB1 also suppressed the expression of ITGB1 and the phosphorylation levels of c-Jun, p38 MAPK, and ERK, further reversing the effects of LAYN overexpression. ConclusionOur results suggest that CREB1 promotes CHOL metastasis through transcriptional regulation of the LAYN-mediated TLN1/β1 integrin axis.

Ligustilide Inhibits the PI3K/AKT Signalling Pathway and Suppresses Cholangiocarcinoma Cell Proliferation, Migration, and Invasion.

Angelica sinensis (Oliv.) Diels, a renowned traditional Chinese medicine, has gained widespread recognition for its antitumor properties. Further investigation is warranted to determine whether ligustilide (LIG), which is extracted from this plant, can effectively inhibit tumors. We delved into the impact of LIG on cholangiocarcinoma cells, aiming to unravel the mechanisms underlying its effects. Cholangiocarcinoma cells (HuccT1 and RBE) were exposed to varying concentrations of LIG (2, 5, 10, 15, 20 μg/mL) for 24, 48, and 72 h. After identifying differentially expressed genes, stable transcription strains were utilized to explore LIG's antitumor mechanism. The inhibitory effects of LIG (5 μg/mL, 48 h) were assessed by CCK-8, colony formation, wound healing, transwell migration, western blotting, and immunofluorescence. In vivo, experiments in NOG mice (Ac, Ac+LIG; five per group) evaluated LIG's antiproliferative efficacy (5 mg/kg, intraperitoneal injection, 18-day period). LIG significantly inhibited cell proliferation and migration with IC50 5.08 and 5.77 μg/mL in HuccT1 and RBE cell lines at 48h, increased the expression of E-cadherin while decreased N-cadherin and the protein of PI3K/AKT pathway. Silenced NDRG1 (N-Myc downstream- regulated gene 1) attenuated these effects. In vivo, the AC+LIG group (LIG, 5 mg/kg, qd, 18 d) exhibited smaller tumor volumes compared to the Ac group. The expression of Ki-67 was significantly downregulated in the AC+LIG group. For the first time, our study has revealed that LIG holds therapeutic potential for treating cholangiocarcinoma. These findings hold promise for advancing innovative therapeutic approaches in the treatment of cholangiocarcinoma. LIG may serve as a useful patent for treating CCA.

Expression and molecular insights of lima1 in cholangiocarcinoma

ABSTRACT Lim Domain and Actin Binding protein1 (lima1) influence cancer cell function. Thus far, functional role of lima1 in cholangiocarcinoma remains unknown. We used public databases, in vitro experiments, and multi-omics analysis to investigate the Lima1 in cholangiocarcinoma. Our results showed that lima1 expression is significantly upregulated and high levels of lima1 are significantly associated with vascular invasion in cholangiocarcinoma. Furthermore, lima1 knocking out inhibits the RBE cell invasion. Multi-omics data suggest that lima1 affect a broad spectrum of cancer related pathways, promoting tumor progression and metastatic ability in cholangiocarcinoma. This study provides insights into molecular associations of lima1 with tumorigenesist and establishes a preliminary picture of the correlation network in cholangiocarcinoma.

Chlorogenic Acid as a Potential Therapeutic Agent for Cholangiocarcinoma.

Chlorogenic acid (CGA) has demonstrated anti-tumor effects across various cancers, but its role in cholangiocarcinoma (CCA) remains unclear. Our study revealed CGA's potent anti-tumor effects on CCA, significantly suppressing cell proliferation, migration, colony formation, and invasion while inhibiting the epithelial-mesenchymal transition. CGA induced apoptosis, modulated cell cycle progression, and exhibited a stable binding affinity to AKR1B10 in CCA. AKR1B10 was highly expressed in RBE cells, and CGA treatment reduced AKR1B10 expression. Knocking out AKR1B10 inhibited the proliferation of RBE cells, whereas the overexpression of AKR1B10 promoted their proliferation. Additionally, CGA suppressed the proliferation of RBE cells with AKR1B10 overexpression. Mechanistically, AKR1B10 activated AKT, and CGA exerted its inhibitory effect by reducing AKR1B10 levels, thereby suppressing AKT activation. Furthermore, CGA facilitated the polarization of tumor-associated macrophages towards an anti-tumor phenotype and enhanced T-cell cytotoxicity. These findings underscore CGA's potential as a promising therapeutic agent for CCA treatment.

EIF3B stabilizes PCNA by counteracting SYVN1-mediated ubiquitination to serve as a promotor in cholangiocarcinoma.

Cholangiocarcinoma, a prevalent hepatic malignancy, exhibits a progressively rising incidence. While Eukaryotic translation initiation factor 3 subunit B (EIF3B) has been implicated in the occurrence and development of various cancers, its specific roles in cholangiocarcinoma remain unexplored. Immunohistochemical (IHC) analysis was employed to detect EIF3B/PCNA expression in cholangiocarcinoma. Cells were manipulated using short hairpin RNA (shRNA)-mediated lentiviruses or overexpression plasmids. Statistical significance was assessed using the Student's t-test and one-way ANOVA, with P < 0.05 considered statistically significant. EIF3B exhibited robust expression in cholangiocarcinoma, demonstrating a significant correlation with the pathological grade of cholangiocarcinoma patients. Furthermore, modulation of EIF3B expression, either depletion or elevation, demonstrated the ability to inhibit or enhance cholangiocarcinoma cell survival and migration in vitro. Mechanistically, we identified Proliferating Cell Nuclear Antigen (PCNA) as a downstream gene of EIF3B, driving cholangiocarcinoma. EIF3B stabilized PCNA by inhibiting PCNA ubiquitination, a process mediated by E3 ligase SYVN1. Similar to EIF3B, PCNA levels were also abundant in cholangiocarcinoma, and knocking down PCNA impeded cholangiocarcinoma development. Intriguingly, silencing PCNA attenuated the promotion induced by EIF3B overexpression. Furthermore, the elevated P21 protein level in shEIF3B RBE cells was partially attenuated after UC2288 (P21 signaling pathway inhibitor) treatment. Our findings underscored the potential of EIF3B as a therapeutic target for cholangiocarcinoma. Unraveling its functions holds promise for the development of more specific and effective targeted therapy strategies.

Neurokinin-1 receptor antagonist aprepitant regulates autophagy and apoptosis via ROS/JNK in intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma (iCCA) has a poor prognosis and limited treatment options. Aprepitant, a selective NK-1R antagonist, can inhibit the growth of various tumours invitro and invivo. However, it remains unclear whether aprepitant has cytotoxic effects on iCCA. We measured the expression of SP/NK-1R in clinical samples of iCCA by immunohistochemistry. Then, we detected the cytotoxic effects of aprepitant on iCCA cells via MTT, EdU and colony formation assay. We constructed a subcutaneous xenograft model of BALB/c nude mice by using HCCC-9810 and RBE cell lines to explore the effects of aprepitant invivo. To elucidate the potential mechanisms, we explored the pro-apoptotic effect of aprepitant by flow cytometric, western blotting, ROS detection and JC-1 staining. Furthermore, we detected the autophagic level of HCCC-9810 and RBE by western blotting, mRFP-eGFP-LC3 adenovirus transfection and electron microscope. SP/NK-1R is significantly expressed in iCCA. Aprepitant inhibited human iCCA xenograft growth and dose-dependently decreased the viability of RBE and HCCC-9810 cells. Aprepitant-induced mitochondria-dependent apoptosis through ROS/JNK pathway. Additionally, pretreatment with z-VAD-fmk partly reversed the effect of aprepitant on cell viability, while NAC completely attenuated the cytotoxic effects of aprepitant invitro. Furthermore, we observed the dynamic changes of autophagosome in RBE and HCCC-9810 cells treated with aprepitant. SP/NK-1R signalling is significantly activated in iCCA and promotes the proliferation of iCCA cells. By contrast, aprepitant can induce autophagy and apoptosis in iCCA cells via ROS accumulation and subsequent activation of JNK.

Abstract 4604: Imipridones ONC201 and ONC212 exhibit anti-tumor activity in biliary tract cancers and synergy when combined with trametinib and olaparib in vitro

Abstract Background: Biliary tract cancers (BTCs) are an aggressive group of malignancies affecting 220,000 new individuals globally each year. Despite advances in immunotherapy and targeted therapies, 5-year survival remains at 2% for those with metastatic disease. Thus, new therapies are desperately needed. The novel imipridone class of antineoplastic agents show promising activity in preclinical pancreatic ductal adenocarcinoma models; however, have not been investigated in BTC. Dordaviprone (ONC201) is a dopamine receptor D2 and mitochondrial protease ClpP modulator that induces apoptosis in cancer cells through both upregulation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and the integrated stress response. ONC212 is a second-generation imipridone that targets orphan GPCR 132 and ClpP, leading to reduced oxidative phosphorylation from ClpX suppression. We hypothesized that the ONC201 and ONC212 would demonstrate antitumor effects in BTCs, both alone, and in combination with MEK and PARP inhibition. Methods: Two established BTC cell lines, RBE and HuCCT1, were used for these experiments. Sensitivity of RBE and HuCCT1 cells to ONC201, ONC212, MEK inhibition (trametinib), and PARP inhibition (olaparib) was assessed using CellTiter-Glo® luminescent cell viability assay. Each cell line was plated on 96-well plates and treated with ONC201 concentrations ranging from 0uM to 40uM for RBE and 0uM to 32uM for HuCCT1; ONC212 ranging from 0nM to 752nM for RBE and 0nM to 640nM for HuCCT1; trametinib ranging from 0nM to 24nM for RBE and 0nM to 16nM for HuCCT1; and olaparib ranging from 0uM to 256uM for RBE and 0uM to 124uM for HuCCT1. Results were analyzed after 72 hours of incubation. Synergy studies were conducted in both cell lines, combining each imipridone with either trametinib or olaparib, and SynergyFinder® was used to evaluate synergy. Western blotting was performed on lysates generated from treated cell lines. Results: Both ONC201 and ONC212 demonstrated antineoplastic effects in two BTC cell lines. Half maximal inhibitory concentrations (IC50) of ONC201 in RBE and HuCCT1 cell lines were 2.5uM and 2.0uM, respectively. The IC50 of ONC212 in RBE and HuCCT1 was 47nM and 39nM, respectively, which was similar to IC50s demonstrated with cytotoxic chemotherapy (gemcitabine IC50 = 7.57nM (RBE) and 9.84nM (HuCCT1)). Both lines also demonstrated sensitivity to trametinib (IC50 = 5.9nM (RBE) and 3.7nM (HCCT1)), and to a lesser extent olaparib (IC50 = 64uM (RBE) and 31uM (HuCCT1)). Although synergy was noted with several combinations, this was most striking with the combination of ONC212 and either trametinib or olaparib. Further analysis of key signal transduction pathways, including MAPK and PI3K, as well as analysis of mechanisms of cell-death through apoptosis, autophagy, ferroptosis, and necroptosis is underway Citation Format: Grace Sun, Alexis J. Lannigan, Jasper Chan, Maximilian Schwermann, Varun V. Prabhu, Lanlan Zhou, Wafik S. El-Deiry, Alexander Grenander Raufi. Imipridones ONC201 and ONC212 exhibit anti-tumor activity in biliary tract cancers and synergy when combined with trametinib and olaparib in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4604.

Abstract 4536: MTAP loss alters the epigenetic landscape and demonstrates superior therapeutic sensitivity to concomitant PRMT5 and PARP inhibition in cholangiocarcinoma

Abstract 5’-methylthioadenosine phosphorylase (MTAP), is deleted in 15% of all cancers (estimated 100,000 patients per year in the United States), including 12-15% of cholangiocarcinoma (CCA) cases. MTAP deficiency accumulates 5’-methylthioadenosine (MTA) that subsequently binds protein arginine methyl transferase 5 (PRMT5) and inhibits its activity. This renders selective targeting of MTAP null tumors with agents (MRTX1719, AMG193, TNG462, TNG908) targeting MTA bound PRMT5 (PRMT5:MTA), while sparing surrounding normal MTAP wild-type (WT) tissue. Early signs of clinical activity was seen with MRTX1719, including objective responses in patients with MTAP loss tumors, including biliary tract cancer from the phase I/II study (NCT05245500). Despite these advances, prolonged targeted therapy poses the risk of development of acquired resistance demanding the need for better therapeutic strategies. To address this pressing need, we co-treated CCA cell lines with MRTX1719 and PARP inhibitor olaparib. We hypothesize that since PRMT5 is a critical regulator of splicing and DNA damage pathways, inhibition of PRMT5 disrupts these downstream processes creating an additional vulnerability to DNA damage inducing agents such as PARP inhibitors. Our preliminary data combining MRTX1719 with olaparib in three MTAP loss CCA cell lines (RBE, YSCCC, TFK1) show synergy (combination index; CI&amp;lt;1), and significant reduction in cell viability as well as colony formation ability when compared to monotherapy in vitro. To further gain mechanistic insights into the biology of MTAP loss, we stably expressed MTAP in MTAP null CCA cell line, RBE and demonstrated that MTAP loss drives tumorigenesis in vivo highlighting its tumor suppressor function in CCA. Mass spectrometry-based profiling of histone modifications from the isogenic RBE cell lines showed heightened methylation and reduced acetylation marks in the absence of MTAP. We also noted substantial differences in the distribution of splicing events, with increased intron retention, 3’ alternative splicing and decreased exon skipping as a result of MTAP loss. Similar differences in proportion of splicing events were also observed in MTAP loss CCA patient derived xenografts as compared to WT models. Collectively, these data implicate MTAP to be a crucial player in modulation of the chromatin and splicing events that may drive therapeutic response to PRMT5 inhibition. Citation Format: Pooja A. Shah, Ajay Kumar Saw, William Padron, Ming Zhao, Argun Akcakanat, Kurt Evans, Funda Meric-Bernstam, Milind Javle, Jordi Rodon, Kunal Rai. MTAP loss alters the epigenetic landscape and demonstrates superior therapeutic sensitivity to concomitant PRMT5 and PARP inhibition in cholangiocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4536.

Cisplatin Disrupts Proteasome Bounce-Back Effect through Suppressing ZEB1/Nfe2l1 in Cholangiocarcinoma.

Bortezomib (BTZ) is a powerful proteasome inhibitor that has been approved for the treatment of haematologic malignancies. Its effectiveness has been assessed against different types of solid tumours. BTZ is ineffective in most solid tumours because of drug resistance, including cholangiocarcinoma, which is associated with a proteasome bounce-back effect. However, the mechanism through which proteasome inhibitors induce the proteasome bounce-back effect remains largely unknown. Cholangiocarcinoma cells were treated with BTZ, cisplatin, or a combination of both. The mRNA levels of Nfe2l1 and proteasome subunit genes (PSMA1, PSMB7, PSMD1, PSMD11, PSMD14, and PSME4) were determined using quantitative real time polymerase chain reaction (qPCR). The protein levels of nuclear factor-erythroid 2-related factor 1 (Nfe2l1) and proteasome enzyme activity were evaluated using western blotting and proteasome activity assays, respectively. Transcriptome sequencing was performed to screen for potential transcription factors that regulate Nfe2l1 expression. The effect of zinc finger E-box-binding homeobox 1 (ZEB1) on the expression of Nfe2l1 and proteasome subunit genes, as well as proteasome enzyme activity, was evaluated after the knockdown of ZEB1 expression with siRNA before treatment with BTZ. The transcriptional activity of ZEB1 on the Nfe2l1 promoter was detected using dual-luciferase reporter gene and chromatin immunoprecipitation assays. Cell viability was measured using the cell counting kit-8 (CCK-8) assay and cell apoptosis was assessed using western blotting and flow cytometry. Cisplatin treatment of BTZ-treated human cholangiocarcinoma cell line (RBE) suppressed proteasome subunit gene expression (proteasome bounce-back) and proteasomal enzyme activity. This effect was achieved by reducing the levels of Nfe2l1 mRNA and protein. Our study utilised transcriptome sequencing to identify ZEB1 as an upstream transcription factor of Nfe2l1, which was confirmed using dual-luciferase reporter gene and chromatin immunoprecipitation assays. Notably, ZEB1 knockdown using siRNA (si-ZEB1) hindered the expression of proteasome subunit genes under both basal and BTZ-induced conditions, leading to the inhibition of proteasomal enzyme activity. Furthermore, the combination treatment with BTZ, cisplatin, and si-ZEB1 significantly reduced the viability of RBE cells. Our study uncovered a novel mechanism through which cisplatin disrupts the BTZ-induced proteasome bounce-back effect by suppressing the ZEB1/Nfe2l1 axis in cholangiocarcinoma. This finding provides a theoretical basis for developing proteasome inhibitor-based strategies for the clinical treatment of cholangiocarcinoma and other tumours.

Low expression of RACK1 is associated with metastasis and worse prognosis in cholangiocarcinoma

BackgroundCholangiocarcinoma is a poorly prognostic malignant tumor, and the metastatic stage of cancer is not an early stage when diagnosed. Lymph node metastasis is common in the early stage. Ribosomal receptor for activated C-kinase 1 (RACK1) has found involved in the oncogenesis of various tumors and in the epithelial-mesenchymal transition (EMT). Nevertheless, its role in cholangiocarcinoma remains unknown. Material and methodsThe possible correlation between RACK1 and tumor prognosis was analyzed in cholangiocarcinoma patients. The GEO and TCGA databases were used to evaluate the level of RACK1 in cholangiocarcinoma. The RBE and HCCC-9810 cell lines were used to examine the effects of RACK1 in the behavior of tumor cells in vitro. ResultsThe Kaplan-Meier analysis indicated that low expression of RACK1 was associated with poor prognosis and RACK1 was negatively related to lymph node metastasis, which were verified in databases TCGA and GEO; downregulation of RACK1 via RNA interference correlated with changes in the expression of EMT biomarkers and promoted the migration of cholangiocarcinoma cell lines. ConclusionThe protein expression of RACK1 is significantly higher in cholangiocarcinoma tissues than in peritumoral tissues, however, the high RACK1 expression indicates better overall survival and less risk for lymph node metastasis. In vitro, RACK1 may suppress the migratory ability of cholangiocarcinoma cells by inhibiting EMT.

Downregulation of JAM3 occurs in cholangiocarcinoma by hypermethylation: A potential molecular marker for diagnosis and prognosis.

Junctional adhesion molecular 3 (JAM3) is downregulated by hypermethylation in cancers but is unclear in cholangiocarcinoma. The JAM3 expression level was checked in cholangiocarcinoma cell lines and tissues. Methylated JAM3 was detected in cell lines, tissues and plasma cell-free DNAs (cfDNA). The roles of JAM3 in cholangiocarcinoma were studied by transfection of siRNA and pCMV3-JAM3. The survival analysis was based on the Gene Set Cancer Analysis (GSCA) database. JAM3 was downregulated in HCCC-9810 and HuCCT1 cell lines and tissues by hypermethylation. Methylated JAM3 was detected in cfDNAs with 53.3% sensitivity and 96.6% specificity. Transfection of pCMV3-JAM3 into HCCC-9810 and HuCCT1 induced apoptosis and suppressed cell proliferation, migration and invasion. The depletion of JAM3 in RBE cells using siRNA decreased apoptosis and increased cell proliferation, migration and invasion. Hypermethylation of JAM3 was associated with tumour differentiation, metastasis and TNM stage. Downregulation and hypermethylation of JAM3 were related to poor progression-free survival. Junctional adhesion molecular 3 may function as a tumour suppressor in cholangiocarcinoma. Methylated JAM3 DNA may represent a non-invasive molecular marker for the early detection of cholangiocarcinoma and prognosis.

Hsa_circ_0050900 affects ferroptosis in intrahepatic cholangiocarcinoma cells by targeting hsa‑miR-605‑3p to regulate SLC3A2.

Intrahepatic cholangiocarcinoma (ICC) is a highly lethal hepatobiliary tumor with high aggressiveness. The role of circular RNA (circRNA) in ICC remains to be explored. The present study aimed to investigate whether hsa_circ_0050900 affected ferroptosis in ICC cells by regulating hsa-microRNA (miR)-605-3p/solute carrier family 3 member 2 (SLC3A2). Human ICC cells were cultured and hsa_circ_0050900 expression was evaluated by reverse transcription-quantitative PCR. hsa_circ_0050900 was knocked down and ferroptosis inhibitor ferrostatin-1 was added to HuCCT-1 cells. Following knockdown or overexpression of hsa-miR-605-3p, Fe2+, reactive oxygen species (ROS), glutathione peroxidase 4 and SLC3A2 levels were assessed using iron and ROS assay kit or RT-qPCR and western blotting, respectively. Cell function experiments were performed to examine proliferation and migration abilities. Dual-luciferase reporter gene and argonaute2-RNA immunoprecipitation assay verified the relationship among hsa_circ_0050900, hsa-miR-605-3p, and SLC3A2. hsa_circ_0050900 was derived from actinin alpha 4 gene and was elevated in ICC cells. Among HuCCT-1, QBC-939, HCCC-9810, and RBE cell lines, the highest expression was in HuCCT-1 cells. Inhibition of hsa_circ_0050900 inhibited proliferation and migration by facilitating ICC cell ferroptosis. hsa-miR-605-3p expression was elevated after knocking down hsa_circ_0050900 and hsa-miR-605-3p was negatively regulated by hsa_circ_0050900. In addition, hsa-miR-605-3p targeted SLC3A2. Overexpression of hsa-miR-605-3p regulated SLC3A2 to promote ICC cell ferroptosis and inhibit proliferation and migration. Taken together, knockdown of hsa_circ_0050900 inhibited SLC3A2 expression via sponging hsa-miR-605-3p to promote ICC cell ferroptosis, and finally suppressed proliferation and migration. The present study suggested that hsa_circ_0050900 was a potential therapeutic target for ICC.

USP10 promotes intrahepatic cholangiocarcinoma cell survival and stemness via SNAI1 deubiquitination.

Cancer cell stemness contributes significantly to intrahepatic cholangiocarcinoma (ICC) progression. However, the roles of deubiquitinating enzymes (DUBs) in ICC modulation are poorly understood. Ubiquitin specific peptidase 10 (USP10) was highly expressed in ICC spheres. The interaction between USP10 and snail family transcriptional repressor 1 (SNAI1) reduced the polyubiquitination of the SNAI1 protein and stabilized the SNAI1 protein. USP10 knockdown in RBE cells inhibited cell proliferation, promoted cell apoptosis and decreased the diameter of the formed spheres and the expression levels of CD44, EpCAM, OCT4 and SOX2. SNAI1 overexpression alleviated the effect of USP10 knockdown in RBE cells. In addition, the knockdown of USP10 attenuated the ability of RBE cells to form tumors subcutaneously in nude mice. Our results revealed that USP10 attenuates ICC cell malignancy by deubiquitinating SNAI1, indicating that USP10 could be developed as a therapeutic target for ICC treatment.

Knockdown of FGFR3 inhibits the proliferation, migration and invasion of intrahepatic cholangiocarcinoma.

The FGF/FGFR signaling axis deregulation of the fibroblast growth factor receptor (FGFR) family is closely related to tumorigenesis, tumor progression and drug resistance to anticancer therapy. And fibroblast growth factor receptor 3 (FGFR3) is one member of this family. In this study, we aimed to investigate the effect of siRNA-induced knockdown of FGFR3 on the biological behaviors of intrahepatic cholangiocarcinoma (ICC). The expression levels of FGFR3 were determined in three intrahepatic cholangiocarcinoma cell lines RBE, HUCCT1 and HCCC9810 cell lines by Western blot. FGFR3 expression in RBE cell line was knocked down by siRNA. Our study found that knockdown of FGFR3 inhibited the migration, invasion and proliferation of ICC cells using Wound healing assay, Transwell migration and invasion assays and Cell proliferation assay. And significantly down-regulated the protein expression levels of MMP2, cyclinD1, and NCadherin, but had no significant effect on MMP9, cyclinD3, vimentin, E-cadherin protein. In addition, we found that ERK/c-Myc presumably is its signaling pathway by bioinformatics analysis and Western blot verification. To sum up, knockdown of FGFR3 inhibited the migration, invasion and proliferation of ICC cells. It demonstrated that FGFR3 probably becomes a therapeutic target for ICC and increases the proportion of potentially curable intrahepatic cholangiocarcinoma patients treated with FGFR inhibitors.

P4HA2 induces hepatic ductular reaction and biliary fibrosis in chronic cholestatic liver diseases.

Prolyl-4-hydroxylases (P4Hs) are key enzymes in collagen synthesis. The P4HA subunit (P4HA1, P4HA2, and P4HA3) contains a substrate binding and catalyzation domain. We postulated that P4HA2 would play a key role in the cholangiocyte pathology of cholestatic liver diseases. We studied humans with primary biliary cholangitis (PBC) and Primary sclerosing cholangitis (PSC), P4HA2 -/- mice injured by DDC, and P4HA2 -/- /MDR2 -/- double knockout mice. A parallel study was performed in patients with PBC, PSC, and controls using immunohistochemistry and immunofluorescence. In the murine model, the level of ductular reaction and biliary fibrosis were monitored by histology, qPCR, immunohistochemistry, and Western blotting. Expression of Yes1 Associated Transcriptional Regulator (YAP) phosphorylation was measured in isolated mouse cholangiocytes. The mechanism of P4HA2 was explored in RBE and 293T cell lines by using qPCR, Western blot, immunofluorescence, and co-immunoprecipitation. The hepatic expression level of P4HA2 was highly elevated in patients with PBC or PSC. Ductular reactive cholangiocytes predominantly expressed P4HA2. Cholestatic patients with more severe liver injury correlated with levels of P4HA2 in the liver. In P4HA2 -/- mice, there was a significantly reduced level of ductular reaction and fibrosis compared with controls in the DDC-induced chronic cholestasis. Decreased liver fibrosis and ductular reaction were observed in P4HA2 -/- /MDR2 -/- mice compared with MDR2 -/- mice. Cholangiocytes isolated from P4HA2 -/- /MDR2 -/- mice displayed a higher level of YAP phosphorylation, resulting in cholangiocytes proliferation inhibition. In vitro studies showed that P4HA2 promotes RBE cell proliferation by inducing SAV1 degradation, eventually resulting in the activation of YAP. P4HA2 promotes hepatic ductular reaction and biliary fibrosis by regulating the SAV1-mediated Hippo signaling pathway. P4HA2 is a potential therapeutic target for PBC and PSC.

Clonorchis sinensis legumain promotes migration and invasion of cholangiocarcinoma cells via regulating tumor-related molecules

BackgroundClonorchis sinensis infection causes serious pathological changes in the bile duct and is highly correlated with cholangiocarcinoma. The excretory–secretory products (ESP) of C. sinensis play a critical role in the oncogenesis and progression of cholangiocarcinoma, while the components and precise mechanism remain unclear. Here, we evaluated the function of C. sinensis legumain (Cslegumain) in promoting the invasion and migration of cholangiocarcinoma cells and the mechanism involved.MethodsThe structural and molecular characteristics of Cslegumain were predicted and analyzed using the online program Phyre2. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical staining were performed to test the transcriptional level of Cslegumain and its localization in the adult. Native Cslegumain was detected by western blotting assay. The effects of Cslegumain on the proliferation, invasion and migration of cholangiocarcinoma cells were checked using CCK-8 assay, Matrigel transwell assay and scratch wound healing assay. Expression levels of tumor-related molecules regulated by Cslegumain were evaluated by qRT-PCR and western blotting assay.ResultsCslegumain showed high similarity with human legumain in the secondary and tertiary structures and displayed higher transcriptional levels in the adult worm than in the metacercariae. Native Cslegumain was detected in a catalytic form and was localized mainly in the intestine of the C. sinensis adult and epithelial cells of the intrahepatic bile duct. After transfection into RBE cells, Cslegumain showed high ability in promoting the invasion and migration but not the proliferation of cholangiocarcinoma RBE cells. Furthermore, the expression levels of some molecules including E-cadherin and N-cadherin were downregulated, while the levels of α-actinin 4, β-catenin and inducible nitric oxide synthase (iNOS) were upregulated.ConclusionsOur findings indicated that Cslegumain showed very similar structures as those of human legumain and could promote the invasion and migration of cholangiocarcinoma cells by regulating some tumor-related molecules.Graphical

Discovery of novel interactions with LCK in cholangiocarcinoma using proximity-dependent biotinylation.

575 Background: Cholangiocarcinoma (CCA) is a lethal hepatobiliary adenocarcinoma with increasing incidence and poor outcomes. Treatment success has been hindered by resistance, and new therapeutic strategies are necessary. The Src-family tyrosine kinase, LCK, activates Yes-associated protein (YAP), a known oncogene in CCA. While YAP has been historically difficult to target, we recently described LCK inhibition as a potential therapeutic option in CCA. We probed the LCK interactome employing biotinylation site identification technology (BioSITe) to discover molecular co-dependencies in the LCK-YAP axis. Methods: LCK-deficient HuCCT1, wild-type HuCCT1, and wild-type RBE cells were transfected with pEF-LCK-TurboID and used to reveal protein-protein interactions. Biotinylated peptides were enriched using anti-biotin antibodies followed by mass spectrometry analysis. Co-immunoprecipitation (Co-IP) was used to confirm interactions between LCK and identified interactors. Phosphoproteome profiling of human CCA tumors and patient derived xenografts was conducted to identify active kinase signatures in CCA. Tyrosine phosphorylated peptides were enriched using anti-phosphotyrosine antibody beads and analyzed by high-resolution mass spectrometery/liquid chromatography. Immunoblot analysis of HuCCT1 and LCK-deficient HuCCT1 cells was used to map the mechanistic interaction between LCK and epidermal growth factor receptor, EGFR. Inhibitors of EGFR and LCK, afatinib and NTRC 0652-0, respectively, were tested in vitro on human and murine CCA cell lines. Cell viability was determined with CellTiter-Glo; Calcusyn software was used to determine synergistic drug effects. Results: We discovered intracellular interactors of LCK in CCA using BioSITe. We identified both known and novel LCK interactors, including EGFR. Given that EGFR functions as a molecular driver of tumorigenesis and is increasingly recognized as a biomarker of resistance in a variety of tumors, we performed a phosphoproteomic evaluation of CCA tumors in which activated EGFR was identified by the presence of EGFR-Y1092, Y1197, and Y1172 phosphorylation. EGFR phosphorylation decreased under conditions of genetic LCK knock out and inhibition by NTRC 0652-0. Co-IP confirmed the interaction of EGFR with LCK. EGFR-Y1092 phosphorylation was downregulated with genetic knockout of LCK by immunoblot. Finally, EGFR inhibition was evaluated as a therapeutic strategy utilizing afatinib. Effects on cell viability were noted in both human and murine CCA cells. Afatinib and NTRC 0652-0 demonstrated a synergistic effect in vitro, with calculated combination indices of 0.007 – 0.790. Conclusions: A novel interaction between EGFR and LCK in CCA was identified using an unbiased proximity-dependent biotinylation technique. Dual blockade of LCK and EGFR is synergistic in CCA and may be a viable therapeutic approach for patients.