Gallbladder Cancer Growth Research Articles

PTBP3 Mediates IL-18 Exon Skipping to Promote Immune Escape in Gallbladder Cancer.

Gallbladder cancer (GBC) is the most common malignant tumor of the biliary system, with poor response to current treatments. Abnormal alternative splicing has been associated with the development of a variety of tumors. Combining the GEO database and GBC mRNA-seq analysis, it is found high expression of the splicing factor polypyrimidine region- binding protein 3 (PTBP3) in GBC. Multi-omics analysis revealed that PTBP3 promoted exon skipping of interleukin-18 (IL-18), resulting in the expression of ΔIL-18, an isoform specifically expressed in tumors. That ΔIL-18 promotes GBC immune escape by down-regulating FBXO38 transcription levels in CD8+T cells to reduce PD-1 ubiquitin-mediated degradation is revealed. Using a HuPBMC mouse model, the role of PTBP3 and ΔIL-18 in promoting GBC growth is confirmed, and showed that an antisense oligonucleotide that blocked ΔIL-18 production displayed anti-tumor activity. Furthermore, that the H3K36me3 promotes exon skipping of IL-18 by recruiting PTBP3 via MRG15 is demonstrated, thereby coupling the processes of IL-18 transcription and alternative splicing. Interestingly, it is also found that the H3K36 methyltransferase SETD2 binds to hnRNPL, thereby interfering with PTBP3 binding to IL-18 pre-mRNA. Overall, this study provides new insights into how aberrant alternative splicing mechanisms affect immune escape, and provides potential new perspectives for improving GBC immunotherapy.

Matrine inhibits invasion and migration of gallbladder cancer via regulating the PI3K/AKT signaling pathway.

Gallbladder cancer (GBC) is a common malignant cancer in the biliary system, which poses a serious threat to human health. It is urgent to explore ideal drugs for the treatment of GBC. Matrine is the main active ingredient of Sophora flavescentis, with a wide range of biological activities encompassing anti-inflammatory, antiviral, immunomodulatory, and anti-tumor. However, the underlying mechanism by which Matrine treats GBC is still unclear. The purpose of this study is to investigate the anti-tumor effects of Matrine on GBC in vivo and in vitro and to clarify the potential regulatory mechanisms. Here, we found that Matrine had a significant killing effect on GBC through CCK8 and flow cytometry, including arrest of cell cycle, inhibition of GBC cell, and induction of apoptosis. Further in vivo studiesconfirmed the inhibitory effect of Matrine on tumor growth in NOZ xenografted nude mouse. At the same time, Matrine also significantly suppressed the migration and invasion of GBC cells through scratch and Transwell experiments. In addition, by detecting the mRNA and protein levels of epithelial-mesenchymal transition (EMT) and matrix metalloproteinases, Matrine furtherly substantiated the inhibitory role on invasion and migration of GBC. From a mechanistic perspective, network pharmacology analysis suggests that the potential targets of Matrine in the treatment of GBC are enriched in the PI3K/AKT signaling pathway. Subsequently, Matrine effectively decreased the abundance of p-PI3K and p-AKT protein in vivo and in vitro. More importantly, PI3K activator (740 Y-P) antagonized the anti-tumor effect of Matrine, while PI3K inhibitor (LY294002) increased the sensitivity of Matrine for GBC. Based on the above findings, we conclude that Matrine inhibits the invasion and migration of GBC by regulating PI3K/AKT signaling pathway. Our results indicate the crucial role and regulatory mechanism of Matrine in suppressing the growth of GBC, which provides a theoretical basis for Matrine to be a candidate drug for the treatment and research of GBC.

Network dynamics investigation of omics-data-driven circadian-hypoxia crosstalk logical model in gallbladder cancer reveals key therapeutic target combinations.

Recent findings in cancer research have pointed towards the bidirectional interaction between circadian and hypoxia pathways. However, little is known about their crosstalk mechanism. In this work, we aimed to investigate this crosstalk at a network level utilizing the omics information of gallbladder cancer. Differential gene expression and pathway enrichment analysis were used for selecting the crucial genes from both the pathways, followed by the construction of a logical crosstalk model using GINsim. Functional circuit identification and node perturbations were then performed. Significant node combinations were used to investigate the temporal behavior of the network through MaBoSS. Lastly, the model was validated using published in vitro experimentations. Four new positive circuits and a new axis viz. BMAL1/ HIF1αβ/ NANOG, responsible for stemness were identified. Through triple node perturbations viz.a. BMAL:CLOCK (KO or E1) + P53 (E1) + HIF1α (KO); b. P53 (E1) + HIF1α (KO) + MYC (E1); and c. HIF1α (KO) + MYC (E1) + EGFR (KO), the model was able to inhibit cancer growth and maintain a homeostatic condition. This work provides an architecture for drug simulation analysis to entrainment circadian rhythm and in vitro experiments for chronotherapy-related studies. Insight Box. Circadian rhythm and hypoxia are the key dysregulated processes which fuels-up the cancer growth. In the present work we have developed a gallbladder cancer (GBC) specific Boolean model, utilizing the RNASeq data from GBC dataset and tissue specific interactions. This work adequately models the bidirectional nature of interactions previously illustrated in experimental papers showing the effect of hypoxia on dysregulation of circadian rhythm and the influence of this disruption on progression towards metastasis. Through the dynamical study of the model and its response to different perturbations, we report novel triple node combinations that can be targeted to efficiently reduce GBC growth. This network can be used as a generalized framework to investigate different crosstalk pathways linked with cancer progression.

Isoliquiritigenin induces HMOX1 and GPX4-mediated ferroptosis in gallbladder cancer cells.

Gallbladder cancer (GBC) is the most common malignant tumor of biliary tract. Isoliquiritigenin (ISL) is a natural compound with chalcone structure extracted from the roots of licorice and other plants. Relevant studies have shown that ISL has a strong anti-tumor ability in various types of tumors. However, the research of ISL against GBC has not been reported, which needs to be further investigated. The effects of ISL against GBC cells in vitro and in vivo were characterized by cytotoxicity test, RNA-sequencing, quantitative real-time polymerase chain reaction, reactive oxygen species (ROS) detection, lipid peroxidation detection, ferrous ion detection, glutathione disulphide/glutathione (GSSG/GSH) detection, lentivirus transfection, nude mice tumorigenesis experiment and immunohistochemistry. ISL significantly inhibited the proliferation of GBC cells in vitro . The results of transcriptome sequencing and bioinformatics analysis showed that ferroptosis was the main pathway of ISL inhibiting the proliferation of GBC, and HMOX1 and GPX4 were the key molecules of ISL-induced ferroptosis. Knockdown of HMOX1 or overexpression of GPX4 can reduce the sensitivity of GBC cells to ISL-induced ferroptosis and significantly restore the viability of GBC cells. Moreover, ISL significantly reversed the iron content, ROS level, lipid peroxidation level and GSSG/GSH ratio of GBC cells. Finally, ISL significantly inhibited the growth of GBC in vivo and regulated the ferroptosis of GBC by mediating HMOX1 and GPX4 . ISL induced ferroptosis in GBC mainly by activating p62-Keap1-Nrf2-HMOX1 signaling pathway and down-regulating GPX4 in vitro and in vivo . This evidence may provide a new direction for the treatment of GBC.

Aprepitant inhibits the development and metastasis of gallbladder cancer via ROS and MAPK activation

BackgroundAprepitant, as a neurokinin-1 receptor (NK-1R) antagonist, originally applied for curing chemotherapy-induced nausea and vomiting, has been reported to have significant antitumor effect on several malignant tumors. However, the effect of aprepitant on gallbladder cancer (GBC) is not clear yet. This study aimed to investigate the anti-tumor activity of aprepitant on GBC and the potential mechanisms.MethodsThe NK-1R expression of gallbladder cancer cells were examined by immunofluorescence. MTT assay, wound healing and transwell migration assay were applied to detect the effect of aprepitant on cell proliferation, migration and invasion. Flow cytometry was used to detect the apoptosis rate. The effects of aprepitant on the expressions of cytokine were examined by real-time quantitative PCR and MAPK activation were detected via immunofluorescence and western blotting. Besides, xenograft model was established to investigate the effect of aprepitant in vivo.ResultsOur results indicated that NK‐1R was markedly expressed in gallbladder cancer cells and aprepitant effectively inhibited the proliferation, migration and invasion. Furthermore, the apoptosis, ROS and inflammation response were significantly boosted by aprepitant in GBC. Aprepitant induced NF‐κB p65 nuclear translocationin and increased the expressions of p-P65, p-Akt, p-JNK, p-ERK and p-P38, as well as the mRNA levels of inflammatory cytokines IL-1β, IL-6 and TNF-α. Consistently, aprepitant suppressed the growth of GBC in xenograft mice model.ConclusionOur study demonstrated that aprepitant could inhibit the development of gallbladder cancer via inducing ROS and MAPK activation, which suggested that aprepitant may become a promising therapeutic drug against GBC.

Knockdown of IGF2BP3 inhibits the tumorigenesis of gallbladder cancer and modifies tumor microenvironment.

Gallbladder cancer (GBC) ranks seventh among the gastrointestinal cancers. Messenger RNAs (mRNAs) could regulate the progression of GBC. For the purpose of exploring the targets for GBC treatment, RNA sequencing was used to identify the differential expressed mRNAs between GBC and adjacent tissues. Next, CCK8 assay was used to assess the cell viability, and cell proliferation was investigated by colony formation assay. Flow cytometry was performed to evaluate the cell apoptosis. Protein and mRNA expression were analyzed by western blot and RT-qPCR, respectively. Transwell was performed to evaluate the cell metastasis. GBC-derived exosomes were isolated with ultracentrifugation. To evaluate the function of exosomes in GBC, in vivo model of GBC was constructed. The data revealed IGF2BP3 was identified to be upregulated in GBC, and IGF2BP3 silencing was able to decrease GBC cell proliferation by promoting the apoptosis. The migration and invasion of GBC cells were reduced by IGF2BP3 knockdown. Silencing of IGF2BP3 obviously suppressed the level of p-STAT3 in GBC cells. Meanwhile, GBC cell-derived exosomes notably promoted macrophage M2 polarization via carrying IGF2BP3, and then the polarized macrophages promoted the malignant behavior of GBC cells. Furthermore, exosomes markedly promoted the tumor growth of GBC via promoting macrophage M2 polarization. In summary, knockdown of IGF2BP3 suppressed the malignant behavior of GBC cells. Additionally, knockdown of IGF2BP3 modified tumor microenvironment during the progression of GBC. Thus, these findings might provide a new theoretical basis for exploring a strategies against GBC.

Experimental study on anti angiogenesis of recombinant mouse angiostatin gene in mice with gallbladder carcinoma.

Gallbladder cancer is one of the gastrointestinal tumors with an extremely poor prognosis. Its incidence rate is gradually increasing worldwide, and the rate of radical resection surgery is extremely low. Not sensitive to radiotherapy and chemotherapy, with a very poor prognosis. This study aimed to investigate whether the recombinant mouse angiostatin gene transfected anti-angiogenic gallbladder cancer cells can express angiostatin protein with the activity of inhibiting the growth of vascular endothelial cells and the inhibitory effect on the growth of gallbladder cancer. The recombinant mouse angiostatin gene eukaryotic expression plasmid was transfected into the gallbladder cancer cell line by applying liposome LIPOFECTAMINE 2000, and its activity was detected by vascular endothelial cell proliferation analysis. The results show that angiostatin can inhibit the growth of transplanted gallbladder cancer, and as the number of injections increases, the inhibition rate of gallbladder cancer growth also increases. At the end of the experiment, the total inhibition rate of gallbladder cancer growth reached 95% 5%, 20%, 30%, 40% gradually increase. Therefore, angiostatin has potential clinical application value in gene therapy of gallbladder cancer.

CircPVT1 promotes gallbladder cancer growth by sponging miR-339-3p and regulates MCL-1 expression

Circular RNAs (circRNAs) have been implicated in modulating biological processes in some tumors. However, the contributions and molecular mechanisms of circRNAs to gallbladder cancer (GBC) remain largely unknown. In the present study, our results showed circPVT1 expression was significantly upregulated in GBC tissues and cells. Higher circPVT1 expression was correlated with lymph node metastasis, advanced TNM stage, and poor overall survival (OS) in patients with GBC. Subsequently, knockdown of circPVT1 significantly impeded GBC cell proliferation, migration, invasion, while induced cell apoptosis in vitro. However, upregulated circPVT1 had the opposite effects. In vivo, we also demonstrated that knockdown of circPVT1 inhibited tumor growth. Furthermore, we confirmed that circPVT1 could regulate Myeloid cell leukemia-1 (MCL-1) expression by sponging to miR-339-3p, which affected tumor progression in GBC cells. In summary, our findings indicated that circPVT1 may serve as a promising prognostic marker and therapeutic target for GBC.

MCL1 participates in leptin-promoted mitochondrial fusion and contributes to drug resistance in gallbladder cancer.

Obesity is a risk factor for gallbladder cancer (GBC) development, and it correlates with shorter overall survival. Leptin, derived from adipocytes, has been suggested to contribute to the growth of cancer cells; however, the detailed mechanism of leptin in GBC drug resistance remains uninvestigated. In this study, our finding that patients with GBC with a higher BMI were associated with increased GBC risks, including shortened survival, is clinically relevant. Moreover, obese NOD/SCID mice exhibited a higher circulating concentration of leptin, which is associated with GBC growth and attenuated gemcitabine efficacy. We further revealed that leptin can inhibit gemcitabine-induced GBC cell death through myeloid cell leukemia 1 (MCL1) activation. The transcription factor C/EBP δ (CEBPD) is responsive to activated STAT3 (pSTAT3) and contributes to MCL1 transcriptional activation upon leptin treatment. In addition, MCL1 mediates leptin-induced mitochondrial fusion and is associated with GBC cell survival. The findings in this study suggest the involvement of the pSTAT3/CEBPD/MCL1 axis in leptin-induced mitochondrial fusion and survival and provide a potentially new therapeutic target to improve the efficacy of gemcitabine in patients with GBC.

Decipher the Helicobacter pylori Protein Targeting in the Nucleus of Host Cell and their Implications in Gallbladder Cancer: An insilico approach.

Gallbladder cancer (GBC) is one of the leading causes of cancer-related mortality worldwide. Researchers have investigated that specific strains of bacteria are connected with growth of different types of cancers in human. Some reports show possible implication of Helicobacter pylori (H. pylori) in the etiology of gallbladder cancer (GBC). Their enigmatic mechanisms, nevertheless, are not still well clear. We sought to predict whether various proteins of H. pylori targeted to nucleus of host cells and their implication in growth of gallbladder cancer. GBC is one of the leading causes of cancer mortality worldwide. We applied bioinformatics approach to analyze the H. pylori proteins targeting into the nucleus of host cells using different bioinformatics predictors including nuclear localization signal (NLS) mapper Balanced Subcellular Localization (BaCelLo) and Hum-mPLoc 2.0. Various nuclear targeting proteins may have a potential role in GBC etiology during intracellular infection. We identified 46 H. pylori proteins targeted into nucleus of host cell through bioinformatics tools. These H. pylori nucleus-targeting proteins might alter the normal function of host cells by disturbing the different pathways including replication, transcription, translation etc. Various nucleus-targeted proteins can affect the normal growth and development of infected cells. We propose that H. pylori proteins targeting into the nucleus of host cells regulate GBC growth using different strategies. These integrative bioinformatics research demonstrated several H. pylori proteins that may serve as possible targets or biomarkers for early cure and treatment or diagnosis GBC.

KIF11 promotes cell proliferation via ERBB2/PI3K/AKT signaling pathway in gallbladder cancer.

Proliferation is one of the significant hallmarks of gallbladder cancer, which is a relatively rare but fatal malignance. Aim of this study was to examine the biological impact and molecular mechanism of the candidate hub-gene on the proliferation and tumorigenesis of gallbladder cancer. We analyzed the differentially expressed genes and the correlation between these genes with MKI67, and showed that KIF11 is one of the major upregulated regulators of proliferation in gallbladder cancer (GBC). The Gene Ontology, Gene Sets Enrichment Analysis and KEGG Pathway analysis indicated that KIF11 may promote GBC cell proliferation through the ERBB2/PI3K/AKT signaling pathway. Gain-of-function and loss-of-function assay demonstrated that KIF11 regulated GBC cell cycle and cancer cell proliferation in vitro. GBC cells exhibited G2M phase cell cycle arrest, cell proliferation and clone formation ability reduction after treatment with Monastrol, a specific inhibitor of KIF11. Xenograft model showed that KIF11 promotes GBC growth in vivo. Rescue experiments showed that KIF11-induced GBC cell proliferation dependented on ERBB2/PI3K/AKT pathway. Moreover, we found that H3K27ac signals are enriched among the promoter region of KIF11 in the UCSC Genome Browser Database. Differentially expressed analysis showed that EP300, a major histone acetyltransferase modifying H3K27ac signal, is highly expressed in gallbladder cancer and correlation analysis illustrated that EP300 is positively related with KIF11 in almost all the cancer types. We further found that KIF11 was significantly downregulated in a dose-dependent and time-dependent manner after histone acetylation inhibitor treatment. The present results highlight that high KIF11 expression promotes GBC cell proliferation through the ERBB2/PI3K/AKT signaling pathway. The findings may help deepen our understanding of mechanism underlying GBC cancer development and development of novel diagnostic and therapeutic target.

APKCι promotes gallbladder cancer tumorigenesis and gemcitabine resistance by competing with Nrf2 for binding to Keap1

Gallbladder cancer (GBC) is a highly malignant bile duct cancer with poor prognosis characterized by its insensitivity to chemotherapy. Emerging evidence indicates that cytoprotective antioxidation is involved in drug resistance of various cancers; however, the underlying molecular mechanisms remain obscure. Here, we demonstrated that atypical protein kinase Cι (aPKCι) mediated reactive oxygen species (ROS) inhibition in a kinase-independent manner, which played a crucial role in tumorigenesis and chemoresistance. Mechanistically, we found that aPKCι facilitated nuclear factor erythroid 2-related factor 2 (Nrf2) accumulation, nuclear translocation and activated its target genes by competing with Nrf2 for binding to Kelch-like ECH-associated protein 1 (Keap1) through a highly conserved DLL motif. In addition, the aPKCι-Keap1 interaction was required for antioxidant effect, cell growth and gemcitabine resistance in GBC. Importantly, we further confirmed that aPKCι was frequently upregulated and correlated with poor prognosis in patients with GBC. Collectively, our findings suggested that aPKCι positively modulated the Keap1-Nrf2 pathway to enhance GBC growth and gemcitabine resistance, implying that the aPKCι-Keap1-Nrf2 axis may be a potential approach to overcome the drug resistance for the treatment of GBC.

Metformin suppresses hypoxia‑induced migration via the HIF‑1α/VEGF pathway in gallbladder cancer in�vitro and in�vivo

Hypoxia plays a crucial role in cancer development and progression. Overexpression of hypoxia-inducible factor-1α (HIF‑1α) has been demonstrated in a hypoxic microenvironment in various tumor types. Metformin has been identified as an antitumor drug in various tumor types. However, its role in cellular migration in a hypoxic microenvironment, and the associated regulatory mechanism, have yet to be fully elucidated. The present study aimed to investigate the clinical significance of HIF‑1α, and its biological role, in gallbladder cancer (GBC). Furthermore, the role of metformin in cellular migration, and its underlying mechanism in GBC, were also identified. Real‑time quantitative polymerase chain reaction analysis and immunohistochemistry experiments revealed that HIF‑1α was significantly upregulated in GBC tissues. HIF‑1α overexpression was closely associated with lymph node metastasis and tumor‑lymph node‑metastasis (TNM) stages. HIF‑1α was able to promote cell migration in a hypoxic microenvironment by overexpressing vascular endothelial growth factor (VEGF) in GBC‑SD cells, an effect which was partly reversed by small‑interfering RNA HIF‑1α (siHIF‑1α) and 2‑methoxyestradiol. Further experiments demonstrated that metformin inhibited hypoxia‑induced migration via HIF‑1α/VEGF invitro. In addition, metformin suppressed GBC growth and downregulated the expression of HIF‑1α and VEGF in a GBC‑SD cell xenograft model. Taken together, these results suggest that HIF‑1α may contribute to tumor migration via the overexpression of VEGF in GBC, while metformin is able to inhibit tumor migration by targeting the HIF‑1α/VEGF pathway.

MiR-143-3p targeting of ITGA6 suppresses tumour growth and angiogenesis by downregulating PLGF expression via the PI3K/AKT pathway in gallbladder carcinoma

Gallbladder cancer (GBC) is the most common malignant tumour of the biliary track system. Angiogenesis plays a pivotal role in the development and progression of malignant tumours. miR-143-3p acts as a tumour suppressor in various cancers. Their role in GBC is however less well defined. Here we show that the expression levels of miR-143-3p were decreased in human GBC tissues compared with the non-tumour adjacent tissue (NAT) counterparts and were closely associated with overall survival. We discovered that miR-143-3p was a novel inhibitor of tumour growth and angiogenesis in vivo and in vitro. Our antibody array, ELISA and PLGF rescue analyses indicated that PLGF played an essential role in the antiangiogenic effect of miR-143-3p. Furthermore, we used miRNA target-prediction software and dual-luciferase assays to confirm that integrin α6 (ITGA6) acted as a direct target of miR-143-3p. Our ELISA and western blot analyses confirmed that the expression of PLGF was decreased via the ITGA6/PI3K/AKT pathway. In conclusion, miR-143-3p suppresses tumour angiogenesis and growth of GBC through the ITGA6/PI3K/AKT/PLGF pathways and may be a novel molecular therapeutic target for GBC.

DUSP1 inhibits cell proliferation, metastasis and invasion and angiogenesis in gallbladder cancer.

DUSP1/MKP1 is a dual-specific phosphatase that regulates MAPK activity and is known to play a key role in tumor biology. Its function in gallbladder cancer (GBC) remains largely unknown, however. By exploring its activities in two GBC cell lines (SGC996 and GBC-SD), DUSP1 was found to inhibit GBC cell proliferation, migration and invasion. Moreover, DUSP1 inhibited GBC growth and metastasis in nude mice subcutaneously xenografted with SGC996 cells. The tumor suppression appeared to be mediated via the DUSP1-pERK/MAPK-MMP2 signal pathway. Angiogenesis was associated with the tumor metastasis in the mouse model and was impaired by DUSP1, which suppressed VEGF expression. These results suggest that DUSP1 suppresses GBC growth and metastasis by targeting the DUSP1-pERK-MMP2/VEGF axis. Identification of the DUSP1-pERK-MMP2/VEGF signals may provide new biomarkers and/or therapeutic targets to better suppress GBC metastasis in the future.

Galectin-9: An anticancer molecule for gallbladder carcinoma

Gallbladder cancer (GBC) is the most common and aggressive type of biliary tract cancer. There are various histological types of GBC, and the vast majority of GBC cases are adenocarcinomas. Squamous and adenosquamous carcinomas are rare GBC subtypes that are traditionally considered to be more aggressive and to be associated with a poorer prognosis than adenocarcinoma. Galectin-9 (Gal-9), a tandem-repeat-type galectin, has been reported to induce apoptosis-mediated elimination of various cancers, including hepatocellular carcinoma, cholangiocarcinoma, and hematologic malignancies. Therefore, we investigated the antitumor effects of Gal-9 on GBC in vitro and in vivo. In our in vitro experiments, Gal-9 suppressed cell proliferation in various GBC cell lines but not in the OCUG-1 cell line, which represents a poorly differentiated type of adenosquamous carcinoma. Gal-9 induced the apoptosis of Gal-9-sensitive GBC cells by increasing the levels of caspase-cleaved keratin 18 and phosphorylated p53. However, Gal-9 did not affect the expression of various cell cycle-related proteins. In addition, Gal-9 suppressed tumor growth by implanted human GBC cells in a xenograft model. Furthermore, Gal-9 induced the phosphorylation of the Ephrin type-B receptor, and the microRNA (miRNA) expression profile was markedly altered by Gal-9. Based on these results, various miRNAs might contribute to the suppression of tumor growth. Our data reveal that Gal-9 suppresses the growth of GBC, possibly by inducing apoptosis and altering miRNA expression. Thus, Gal-9 might serve as a therapeutic agent for the treatment of GBC.

20(S)-ginsenoside Rg3 promotes senescence and apoptosis in gallbladder cancer cells via the p53 pathway.

Gallbladder cancer (GBC), the most frequent malignancy of the biliary tract, is associated with high mortality and extremely poor prognosis. 20(S)-ginsenoside Rg3 (20(S)-Rg3) is a steroidal saponin with high pharmacological activity. However, the anticancer effect of 20(S)-Rg3 in human GBC has not yet been determined. In this study, we primarily found that 20(S)-Rg3 exposure suppressed the survival of both NOZ and GBC-SD cell lines in a concentration-dependent manner. Moreover, induction of cellular senescence and G0/G1 arrest by 20(S)-Rg3 were accompanied by a large accumulation of p53 and p21 as a result of murine double minute 2 (MDM2) inhibition. 20(S)-Rg3 also caused a remarkable increase in apoptosis via the activation of the mitochondrial-mediated intrinsic caspase pathway. Furthermore, intraperitoneal injection of 20(S)-Rg3 (20 or 40 mg/kg) for 3 weeks markedly inhibited the growth of xenografts in nude mice. Our results demonstrated that 20(S)-Rg3 potently inhibited growth and survival of GBC cells both in vitro and in vivo. 20(S)-Rg3 attenuated GBC growth probably via activation of the p53 pathway, and subsequent induction of cellular senescence and mitochondrial-dependent apoptosis. Therefore, 20(S)-Rg3 may be a potential chemotherapeutic agent for GBC therapy.

Loss of angiotensin-converting enzyme 2 promotes growth of gallbladder cancer.

The aim of this study is to investigate the role of angiotensin-converting enzyme 2 (ACE2) in gallbladder cancer (GBC) and the therapeutic potential of angiotensin receptor blocker in GBC. Human gallbladder epithelial cells (HGBEC) together with GBC cells and tissue samples were used. In vitro studies were carried out to investigate the role of ACE2 in GBC cells. ACE2 levels were studied in in vivo GBC mouse models subject to ARB treatment. ACE2 level was decreased in GBC cells compared with that in normal gallbladder cells. Replenishment of angiotensin II (A2) promoted tumour cell growth, which could be mitigated by ACE2 supplement. ARB blocked A2-induced GBC cell growth and activated ERK. Activity of mTOR was not altered with different ACE2 status. ARB inhibited tumour growth in xenograft mouse models. In vivo study also showed that decreased expression of ACE2 was associated with enlarged tumour size. By genetic replenishment of ACE2 and pharmaceutical use of ARB, restored ACE2 level mitigated GBC growth. Our results supported the rationale for the use of ARB in GBC patients for potential therapeutic benefit.

The inhibitory effects of deleted in liver cancer 1 gene on gallbladder cancer growth through induction of cell cycle arrest and apoptosis

The biological function of tumor suppressor deleted in liver cancer 1 (DLC1) has been investigated in several types of human cancer, but its role in gallbladder cancer (GBC) is yet to be determined. In this research, we conducted in vitro and in vivo analysis to evaluate the inhibitory activities of DLC1 gene against GBC growth. DLC1 expression in GBC tissues and cell lines was examined by immunohistochemical staining, reverse transcription polymerase chain reaction, and Western blot assay. The in vitro and in vivo effects of ectopic DLC1 expression on cell growth were evaluated. In addition, the effects of ectopic DLC1 expression on cell cycle, apoptosis, and migration were also evaluated. The expressions of cell cycle-related and apoptosis-related proteins were examined. The downregulation of DLC1 expression was a common event in GBC tissues and cell lines. Restoration of DLC1 expression in GBC-SD and NOZ cells significantly reduced cell proliferation, migration in vitro, and the ability of these cells to form tumors in vivo. Restoration of DLC1 expression arrested GBC-SD and NOZ cells in G0/G1 phase through inducing p21 in a p53-independent manner. In addition, restoration of DLC1 expression induced extrinsic and intrinsic apoptotic pathway through promoting the expressions of Fas L/FADD, Bax, cytochrome c, cleaved caspase-8, -9, -3, and cleaved poly-(ADP-ribose) polymerase and suppressing bcl-2 expression in GBC-SD and NOZ cells. Our findings suggested that dysregulated expression of DLC1 is involved in proliferation and invasion of GBC cells and may serve as a potential therapeutic target.

NLK is a key regulator of proliferation and migration in gallbladder carcinoma cells

Gallbladder cancer (GBC) is one of the most lethal neoplasm and is the fifth most common malignancy of gastrointestinal tract. The prognosis of gallbladder cancer is extremely terrible partially due to metastasis. Thus, understanding the molecular pathways controlling metastasis of this lethal disease may provide new targets for targeted therapeutic approach. In this study, we investigated the function of nemo-like kinase (NLK) in GBC growth and migration. Lentivirus-mediated siRNA was employed to alleviate the expression level of NLK in GBC cell lines (GBC-SD and SGC-996). Real-time PCR and western-blot analysis demonstrated that both mRNA and protein levels of NLK in GBC-SD and SGC-996 cells were decreased after infection with NLK-siRNA-expressing lentivirus (Lv-shNLK). The proliferation and in vitro tumorigenesis (colony formation) ability as well as migration of GBC-SD and SGC-996 cells with low NLK expression decreased significantly. Our results suggested that NLK is a key regulator involved in proliferation and migration of GBC, and it could be used as a potential therapeutic target for GBC.