Yijun Shu

Whole-exome and targeted gene sequencing of gallbladder carcinoma identifies recurrent mutations in the ErbB pathway

Individuals with gallbladder carcinoma (GBC), the most aggressive malignancy of the biliary tract, have a poor prognosis. Here we report the identification of somatic mutations for GBC in 57 tumor-normal pairs through a combination of exome sequencing and ultra-deep sequencing of cancer-related genes. The mutation pattern is defined by a dominant prevalence of C>T mutations at TCN sites. Genes with a significant frequency (false discovery rate (FDR) < 0.05) of non-silent mutations include TP53 (47.1%), KRAS (7.8%) and ERBB3 (11.8%). Moreover, ErbB signaling (including EGFR, ERBB2, ERBB3, ERBB4 and their downstream genes) is the most extensively mutated pathway, affecting 36.8% (21/57) of the GBC samples. Multivariate analyses further show that cases with ErbB pathway mutations have a worse outcome (P = 0.001). These findings provide insight into the somatic mutational landscape in GBC and highlight the key role of the ErbB signaling pathway in GBC pathogenesis.

MALAT1 promotes the proliferation and metastasis of gallbladder cancer cells by activating the ERK/MAPK pathway.

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long non-coding RNA (lncRNA), is associated with metastasis and is an independent prognostic factor for lung cancer. Recent studies have demonstrated that MALAT1 plays an important role in other malignancies. However, little is known about the role of MALAT1 in gallbladder carcinoma (GBC), which is the most common cancer of the biliary tract and has an extremely poor prognosis. In this study, we focused on the expression, biological functions and mechanism of MALAT1 in GBC and found that MALAT1 was significantly upregulated in GBC tissues compared with corresponding non-cancerous tissues. Knockdown of MALAT1 in GBC cell lines using lentivirus-mediated RNA interference significantly inhibited the proliferation and metastasis of the GBC cells both in vitro and in vivo. Furthermore, ERK/MAPK pathway was found to be inactivated in the GBC cell lines after MALAT1 knockdown. These results indicated that MALAT1 might serve as an oncogenic lncRNA that promotes proliferation and metastasis of GBC and activates the ERK/MAPK pathway

Evaluation of two inflammation-based prognostic scores in patients with resectable gallbladder carcinoma.

BackgroundSurvival after surgery for gallbladder cancer is generally poor. A number of inflammation-based prognostic scores have been established to help predict survival after surgery for several types of cancer. The objective of this study was to analyze and compare the utility of two inflammation-based prognostic scores, the Glasgow prognostic score (GPS) and the neutrophil-to-lymphocyte ratio (NLR), for predicting survival in patients with gallbladder cancer after surgery with curative intent.MethodsWe retrospectively reviewed the medical records of 85 patients with histologically confirmed, resectable gallbladder carcinoma (GBC), who were to receive curative surgery in our department. Univariate and multivariate analyses were performed to evaluate the relationship between the variables to overall survival (OS).ResultsA significant difference was detected in OS in patients with low and high GPS and NLR scores. Univariate analyses using clinicopathological characteristics revealed that tumor differentiation; tumor invasion; lymph node metastasis; tumor, node, metastasis classification system stage; positive margin status; combined common bile duct resection; serum levels of C-reactive protein, albumin, carbohydrate antigen 19-9 (CA19-9), carcinoembryonic antigen, and CA125; white blood cell count; and GPS and NLR were all associated with OS. Among these characteristics, multivariate analysis demonstrated that a high GPS was independently associated with poorer OS, together with tumor invasion, lymph node metastasis, and positive margin status.ConclusionsGPS is superior to NLR with respect to its prognostic value for patients with GBC after surgery with curative intent. GPS is not only associated with tumor progression but is also an independent marker of poor prognosis.

SPOCK1 as a potential cancer prognostic marker promotes the proliferation and metastasis of gallbladder cancer cells by activating the PI3K/AKT pathway

BackgroundGallbladder cancer (GBC) is a leading cause of cancer-related death worldwide, and its prognosis remains poor, with 5-year survival of approximately 5%. In this study, we analyzed the involvement of a novel proteoglycan, Sparc/osteonectin, cwcv, and kazal-like domains proteoglycan 1 (SPOCK1), in the tumor progression and prognosis of human GBC.MethodsSPOCK1 expression levels were measured in fresh samples and stored specimens of GBC and adjacent nontumor tissues. The effect of SPOCK1 on cell growth, DNA replication, migration and invasion were explored by Cell Counting Kit-8, colony formation, EdU retention assay, wound healing, and transwell migration assays, flow cytometric analysis, western blotting, and in vivo tumorigenesis and metastasis in nude mice.ResultsSPOCK1 mRNA and protein levels were increased in human GBC tissues compared with those in nontumor tissues. Immunohistochemical analysis indicated that SPOCK1 levels were increased in tumors that became metastatic, compared with those that did not, which was significantly associated with histological differentiation and patients with shorter overall survival periods. Knockdown of SPOCK1 expression by lentivirus-mediated shRNA transduction resulted in significant inhibition of GBC cell growth, colony formation, DNA replication, and invasion in vitro. The knockdown cells also formed smaller xenografted tumors than control GBC cells in nude mice. Overexpression of SPOCK1 had the opposite effects. In addition, SPOCK1 promoted cancer cell migration and epithelial-mesenchymal transition by regulating the expression of relevant genes. We found that activation of the PI3K/Akt pathway was involved in the oncogenic functions of SPOCK1 in GBC.ConclusionsSPOCK1 activates PI3K/Akt signaling to block apoptosis and promote proliferation and metastasis by GBC cells in vitro and in vivo. Levels of SPOCK1 increase with the progression of human GBC. SPOCK1 acts as an oncogene and may be a prognostic factor or therapeutic target for patients with GBC.

Yes-associated protein 1 (YAP1) promotes human gallbladder tumor growth via activation of the AXL/MAPK pathway.

The transcriptional coactivator Yes-associated protein 1 (YAP1), a key regulator of cell proliferation and organ size in vertebrates, has been implicated in various malignancies. However, little is known about the expression and biological function of YAP1 in human gallbladder cancer (GBC). In this study we examined the clinical significance and biological functions of YAP1 in GBC and found that nuclear YAP1 and its target gene AXL were overexpressed in GBC tissues. We also observed a significant correlation between high YAP1 and AXL expression levels and worse prognosis. The depletion of YAP1 using lentivirus shRNAs significantly inhibited cell proliferation by inducing cell cycle arrest in S phase in concordance with the decrease of CDK2, CDC25A, and cyclin A, and resulted in increased cell apoptosis and invasive repression in GBC cell lines in vitro. Furthermore, knockdown of YAP1 also inhibited tumor growth in vivo. Additionally, we demonstrated that the activation of the AXL/MAPK pathway was involved in the oncogenic functions of YAP1 in GBC. These results demonstrated that YAP1 is a putative oncogene and represents a prognostic marker and potentially a novel therapeutic target for GBC.

Fibronectin promotes cell proliferation and invasion through mTOR signaling pathway activation in gallbladder cancer

Fibronectin (FN), a heterodimeric glycoprotein overexpressed in several types of tumors, has been implicated in cancer progression via the activation of integrin-mediated pro-oncogenic pathways. The FN level in human bile fluid is dramatically increased in malignant biliary diseases; however, FN expression and its biological functions in gallbladder cancer (GBC) remain unknown. In this study, we found that FN was overexpressed in GBC tissues and was associated with a worse prognosis in GBC patients. In vitro experimental studies indicated that exogenous FN significantly enhanced cell proliferation, invasion and active MMP-9 secretion in human GBC cell lines (GBC-SD and NOZ). Moreover, the key kinases of the mTOR signaling pathway, including FAK, Akt, mTOR and 4E-BP1, were markedly activated in a time-dependent manner in FN-treated GBC-SD and NOZ cells. The IHC statistical analyses validated that FN expression was positively correlated with the phosphorylation levels of the 4E-BP1 protein in GBC tissues. Furthermore, rapamycin, a specific inhibitor of mTOR, almost completely blocked FN-induced phosphorylation of 4E-BP1 and also partially abrogated the stimulatory effects of FN on GBC cell proliferation and invasion. In vivo, FN treatment significantly promoted the proliferation and metastasis of GBC cells and markedly activated Akt/mTOR/4E-BP1 signaling cascade. These findings demonstrate that FN may play a critical role in the modulation of cell proliferation and invasion via mTOR signaling pathway activation during GBC progression.

Prognostic significance of nemo-like kinase (NLK) expression in patients with gallbladder cancer.

Nemo-like kinase (NLK), a serine/threonine protein kinase, has been implicated in tumor development and progression, and plays an important role in diverse signaling pathways by phosphorylating a variety of transcription factors. Recent studies demonstrated that altered expression of NLK was observed in various types of human cancers. However, the clinical significance of NLK expression in gallbladder cancer (GBC) remains largely unknown. In this study, we focused on the clinical significance of NLK in GBC, and found that nuclear NLK protein overexpression was frequently detected in GBC tissues. The overexpression of NLK was significantly correlated with histological grade, TNM stage, and perineural invasion. The results of Kaplan–Meier analysis indicated that a high expression level of NLK resulted in a significantly poorer prognosis of GBC patients (P = 0.002). Furthermore, multivariate Cox regression analysis showed that high NLK expression was an independent prognostic factor for GBC patients (HR = 3.077). In conclusion, overexpression of NLK is closely related to progression of GBC, and NLK could be used as a potential prognostic marker for GBC patients.

Downregulated expression of hepatoma-derived growth factor (HDGF) reduces gallbladder cancer cell proliferation and invasion.

Hepatoma-derived growth factor (HDGF), a heparin-binding growth factor, has a wide range of biological functions, including mitogenic activity and vascular development. Recent studies demonstrated that HDGF also acted as an oncogene with aberrantly increased activity in multiple human cancers; however, little is known about the biological function of HDGF in gallbladder cancer (GBC). In this study, we focused on the clinical significance and biological functions of HDGF in GBC and found that Nuclear HDGF protein overexpression was frequently detected in GBC tissues. Patients with nuclear HDGF-positive tumors had worse overall survival than patients with HDGF-negative tumors. Furthermore, treatment of GBC lines with HDGF-targeting siRNA oligonucleotides (HDGF-siRNA) significantly reduced the proliferation of GBC-SD and SGC-996 cell lines and diminished both anchorage-independent growth on soft agar and cell migration. These data indicate that HDGF acts as a putative oncogene in GBC and could be a novel diagnostic and therapeutic target for GBC.

Ursolic acid induces cell cycle arrest and apoptosis of gallbladder carcinoma cells

BackgroundUrsolic acid (UA), a plant extract used in traditional Chinese medicine, exhibits potential anticancer effects in various human cancer cell lines in vitro. In the present study, we evaluated the anti-tumoral properties of UA against gallbladder carcinoma and investigated the potential mechanisms responsible for its effects on proliferation, cell cycle arrest and apoptosis in vitro.MethodsThe anti-tumor activity of UA against GBC-SD and SGC-996 cells was assessed using MTT and colony formation assays. An annexin V/PI double-staining assay was used to detect cell apoptosis. Cell cycle changes were detected using flow cytometry. Rhodamine 123 staining was used to assess the mitochondrial membrane potential (ΔΨm) and validate UA’s ability to induce apoptosis in both cell lines. The effectiveness of UA in gallbladder cancer was further verified in vivo by establishing a xenograft GBC model in nude mice. Finally, the expression levels of cell cycle- and apoptosis-related proteins were analyzed by western blotting.ResultsOur results suggest that UA can significantly inhibit the growth of gallbladder cancer cells. MTT and colony formation assays indicated dose-dependent decreases in cell proliferation. S-phase arrest was observed in both cell lines after treatment with UA. Annexin V/PI staining suggested that UA induced both early and late phases of apoptosis. UA also decreased ΔΨm and altered the expression of molecules regulating the cell cycle and apoptosis. In vivo study showed intraperitoneally injection of UA can significantly inhibited the growth of xenograft tumor in nude mice and the inhibition efficiency is dose related. Activation of caspase-3,-9 and PARP indicated that mitochondrial pathways may be involved in UA-induced apoptosis.ConclusionsTaken together, these results suggest that UA exhibits significant anti-tumor effects by suppressing cell proliferation, promoting apoptosis and inducing 7cell cycle arrest both in vitro and in vivo. It may be a potential agent for treating gallbladder cancer.

MicroRNA-29c-5p suppresses gallbladder carcinoma progression by directly targeting CPEB4 and inhibiting the MAPK pathway.

Gallbladder cancer (GBC) is a leading cause of cancer-related deaths worldwide, and its prognosis remains poor, with a 5-year survival rate of ~5%. Given the crucial role of microRNAs (miRNAs) in cancer metastasis, we aimed to analyze the expression and function of the metastasis-associated miRNA miR-29c-5p in GBC.We validated that expression of miR-29c-5p was significantly downregulated in GBC and was closely associated with lymph node metastasis, overall survival and disease-free survival in 40 GBC patients who were followed clinically. Ectopic overexpression of miR-29c-5p dramatically repressed proliferation, metastasis, and colony formation and induced apoptosis in vitro, and it suppressed tumorigenicity in vivo through the MAPK pathway. Cytoplasmic polyadenylation element binding protein 4 (CPEB4) was identified as a critical effector target of miR-29c-5p. Enforced expression of miR-29c-5p significantly inhibited the expression of CPEB4, and restoration of CPEB4 expression reversed the inhibitory effects of miR-29c-5p on GBC cell proliferation and metastasis. Transforming growth factor-β (TGF-β) upregulated CPEB4 by downregulating miR-29c-5p, leading to MAPK pathway activation. In conclusion, the TGF-β/miR-29c-5p/CPEB4 axis has a pivotal role in the pathogenesis and poor prognosis of GBC, suggesting that miR-29c-5p is a tumor-suppressive miRNA that may serve as potential prognostic biomarker or therapeutic target for GBC.