Phase II study of temozolomide monotherapy in patients with extrapulmonary neuroendocrine carcinoma.

Extrapulmonary neuroendocrine carcinoma (EPNEC) is a lethal disease with a poor prognosis. Platinum-based chemotherapy is used as the standard first-line treatment for unresectable EPNEC. Several retrospective studies have reported the results of the utilization of temozolomide (TMZ) as a drug for the second-line treatment for EPNEC. Patients with unresectable EPNEC that were resistant to platinum-based combination chemotherapy were recruited for a prospective phase II study of TMZ monotherapy. A 200 mg/m2 dose of TMZ was given from day 1 to day 5, every 4 weeks. Response rate (RR) was evaluated as the primary end-point. The presence of O6 -methylguanine DNA methyltransferase (MGMT) in EPNEC patients was also evaluated as exploratory research. Thirteen patients were enrolled in this study. Primary lesions were pancreas (n = 3), stomach (n = 3), duodenum (n = 1), colon (n = 1), gallbladder (n = 1), liver (n = 1), uterus (n = 1), bladder (n = 1), and primary unknown (n = 1). Each case was defined as pathological poorly differentiated neuroendocrine carcinoma from surgically resected and/or biopsied specimens. The median Ki-67 labeling index was 60% (range, 22%-90%). The RR was 15.4%, progression-free survival was 1.8 months (95% confidence interval [CI], 1.0-2.7), overall survival (OS) was 7.8 months (95% CI, 6.0-9.5), and OS from first-line treatment was 19.2 months (95% CI, 15.1-23.3). No grade 3 or 4 hematological toxicity had occurred and there was one case of grade 3 nausea. One case presented MGMT deficiency and this case showed partial response. Temozolomide monotherapy is a feasible, modestly effective, and safe treatment for patients with unresectable EPNEC following platinum-based chemotherapy, especially those with MGMT deficiency.

Case Report: Addition of PD-1 Antibody Camrelizumab Overcame Resistance to Trastuzumab Plus Chemotherapy in a HER2-Positive, Metastatic Gallbladder Cancer Patient.

HER2 amplification/overexpression is a common driver in a variety of cancers including gallbladder cancer (GBC). For patients with metastatic GBC, chemotherapy remains the standard of care with limited efficacy. The combination of HER2 antibody trastuzumab plus chemotherapy is the frontline treatment option for patients with HER2-positive breast cancer and gastric cancer. Recently, this regime also showed antitumor activity in HER2-positive GBC. However, resistance to this regime represents a clinical challenge. Camrelizumab is a novel PD-1 antibody approved for Hodgkin lymphoma and hepatocellular carcinoma in China. In this study, we presented a HER2-positive metastatic GBC patient who was refractory to trastuzumab plus chemotherapy but experienced significant clinical benefit after the addition of camrelizumab. Our case highlights the potential of immunotherapy in combination with HER2-targeted therapy in HER2-positive GBC. We also demonstrated that two immune-related adverse events (irAEs) associated with camrelizumab can be managed with an anti-VEGF agent apatinib. This case not only highlights the importance of irAE management in patients treated with camrelizumab, but also demonstrates the potential of PD-1 antibody plus trastuzumab in HER2-positive GBC patients who have developed resistance to chemotherapy and trastuzumab-based targeted therapy.

Loss of desmoglein-2 promotes gallbladder carcinoma progression and resistance to EGFR-targeted therapy through Src kinase activation.

Gallbladder carcinoma (GBC) exhibits poor prognosis due to local recurrence, metastasis, and resistance to targeted therapies. Using clinicopathological analyses of GBC patients along with molecular in vitro and tumor in vivo analysis of GBC cells, we showed that reduction of Dsg2 expression was highly associated with higher T stage, more perineural, and lymphatic invasion. Dsg2-depleted GBC cells exhibited significantly enhanced proliferation, migration, and invasiveness in vitro and tumor growth and metastasis in vivo through Src-mediated signaling activation. Interestingly, Dsg2 binding inhibited Src activation, whereas its loss activated cSrc-mediated EGFR plasma membrane clearance and cytoplasmic localization, which was associated with acquired EGFR-targeted therapy resistance and decreased overall survival. Inhibition of Src activity by dasatinib enhanced therapeutic response to anti-EGFR therapy. Dsg2 status can help stratify predicted patient response to anti-EGFR therapy and Src inhibition could be a promising strategy to improve the clinical efficacy of EGFR-targeted therapy.

Tamoxifen inhibits cell proliferation by impaired glucose metabolism in gallbladder cancer.

Gallbladder cancer (GBC) is the leading malignancy of biliary system showing refractory chemoresistance to current first-line drugs. Growing epidemiological evidences have established that the incidence of GBC exhibits significant gender predominance with females two-threefold higher than males, suggesting oestrogen/oestrogen receptors (ERs) signalling might be a critical driver of tumorigenesis in gallbladder. This study aims to evaluate the antitumour activity of tamoxifen (TAM), a major agent of hormonal therapy for breast cancer, in preclinical GBC model. Quantitative real-time PCR was used to investigate mRNA levels. Protein expression was measured by immunohistochemistry and Western blot. Glycolytic levels were measured by glucose consumption and lactic acid measurement. The antitumour activity of TAM alone or with cisplatin was examined with CCK8 assay, colony formation, flow cytometry and in vivo models. The results revealed that ERɑ expression was higher in GBC tissues and predicted poor clinical outcomes. TAM was showed effective against a variety of GBC cell lines. Mechanical investigations revealed that TAM enabled potent reactive oxygen species (ROS) production by reduced nuclear factor Nrf2 expression and its target genes, leading to the activation of AMPK, which subsequently induced impaired glycolysis and survival advantages. Notably, TAM was demonstrated to sensitize GBC cells to cisplatin (CDDP) both in vitro and in vivo. In agreement with these findings, elimination of oestrogens by ovariectomy in nude mice prevented CDDP resistance. In summary, these results provide basis for TAM treatment for GBC and shed novel light on the potential application of endocrine therapy for patients with GBC.

Upregulated NOX1 expression in gallbladder cancer­associated fibroblasts predicts a poor prognosis.

Gallbladder cancer (GBC) is a lethal aggressive malignant neoplasm of the biliary tract. Potential prognostic markers and therapeutic targets for this disease are urgently required. Cancer­associated fibroblasts (CAFs) play a key role in tumorigenesis and the development of cancer. Nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1) expression has been reported to be involved in tumorigenesis and useful for tumor prognosis. However, NOX1 expression in the stroma of GBCs, particularly gallbladder cancer­associated fibroblasts (GCAFs), and its prognostic significance in GBC patients remains unclear. In the present study, NOX1 expression in the stroma of human gallbladder lesions in vivo was investigated, as well as in GCAFs and co­cultures of GBC­SD+GCAFs in vitro, and their correlation with clinicopathological parameters and the prognosis of GBC patients were evaluated. The results revealed that NOX1 expression was significantly upregulated in the stroma of GBCs compared with precancerous and benign lesions of the gallbladder; NOX1 expression was localized to gallbladder stromal fibroblasts expressing α­smooth muscle actin and fibroblast secreted protein­1. Furthermore, these observations were confirmed by the fact that NOX1 expression was upregulated in GCAFs as determined by Affymetrix gene profile chip analysis and reverse transcription­quantitative PCR. In addition, overexpression was observed in formed spheroids of GBC­SD+GCAF co­cultures by immunohistochemistry and western blotting in vitro. Thus, it was verified that NOX1 expression was upregulated in GCAFs. Furthermore, upregulated stromal NOX1 expression was correlated with aggressive characteristics such as differentiation degree (P=0.042), venous invasion (P=0.041), resection methods (P=0.002), and a lower survival rate (P=0.025, log­rank test) of patients with GBC. Stromal NOX1 expression (P=0.047) was an independent prognostic factor for the overall survival rate of patients with GBC. GBC patients with upregulated NOX1 expression in GCAFs had a poorer prognosis. These results revealed that stromal NOX1 may be a novel biomarker and/or target, and may contribute to the discovery of new tumor markers and potential targeted therapeutics for human GBCs.

DMBT1 suppresses progression of gallbladder carcinoma through PI3K/AKT signaling pathway by targeting PTEN.

Gallbladder carcinoma (GBC) is a highly lethal malignancy of the gastrointestinal tract. Despite extensive research, the underlying molecular mechanism of GBC remains largely unclear. Deleted in malignant brain tumors 1 (DMBT1) is low-expression during cancer progression and as a potential tumor-suppressor gene in various types of cancer. However, its role in Gallbladder cancer remains poorly understood. Here, we found that DMBT1 was significantly low-expression and deletion of copy number in GBC tissues by qRT-PCR and Western blot. Overexpression of DMBT1 impaired survival, promoted apoptosis in GBC cells in vitro, and inhibited tumor progression in vivo. Further study of underlying mechanisms demonstrated that DMBT1 combined with PTEN which could stabilize PTEN protein, resulting in inhibiting the activation of PI3K/AKT signaling pathway. Our study revealed a new sight of DMBT1 as a tumor-suppressor gene on the PI3K/AKT pathway in GBC, which may be a potential therapeutic target for improving treatment.

Knockdown of TRIM31 suppresses proliferation and invasion of gallbladder cancer cells by down-regulating MMP2/9 through the PI3K/Akt signaling pathway.

Tripartite motif (TRIM) 31, a member of the TRIM protein family, contributes to a wide range of biological processes and its altered expression exerts a non-negligible effect on multiple pathological conditions such as immunological disorders and retroviral protective activity. Recently, increasing evidence has demonstrated an important role of TRIM31 in the development of various cancers. However, the role of TRIM31 in gallbladder cancer (GBC) remains unclear. In this study, we showed that TRIM31 was elevated in GBC tissues and cell lines and associated with the clinicopathological features of GBC patients. Down-regulation of TRIM31 suppressed GBC cell proliferation, migration and invasion in vitro as well as inhibited tumor growth and metastasis in vivo. In addition, knockdown of TRIM31 reduced the expression of MMP2, MMP9 and p-Akt. Taken together, these findings indicated that knockdown of TRIM31 suppressed proliferation and invasion of GBC cells and was associated with PI3K/Akt signaling inactivation. Thus, TRIM31 may be a potential therapeutic target for the treatment of GBC.

The Novel Selective Pan-TRK Inhibitor ONO-7579 Exhibits Antitumor Efficacy Against Human Gallbladder Cancer In Vitro.

We previously reported that brain-derived neurotrophic factor (BDNF)/neurotrophic receptor tyrosine kinase 2 (NTRK2/TRKB) signaling contributes to induction of malignant phenotype of gallbladder cancer (GBC). Recently, pan-TRK inhibitors have been evaluated and their dramatic clinical activity is being shown for a variety of cancer types harboring an NTRK rearrangement in phase I trials. ONO-7579 is an oral pan-TRK inhibitor currently under investigation in phase I/II clinical trial for TRK-rearranged solid tumors. In this study, we evaluated the anticancer effect of ONO-7579 using GBC cells with or without KRAS mutant, NOZ, TYGBK-1. Our study showed that ONO-7579 had a suppressive effect on GBC proliferation in TYGBK-1, and on invasive potential and vascular endothelial growth factor expression in TYGBK-1 and NOZ. Our data indicated that ONO-7579 could be a promising treatment option for patients with GBC.

STYK1 promotes cancer cell proliferation and malignant transformation by activating PI3K-AKT pathway in gallbladder carcinoma.

Gallbladder carcinoma (GBC) is the most common malignancy of the biliary tract with extremely poor prognosis. The malignant transformation of GBC is associated with cell proliferation, invasion, and epithelial-mesenchymal transition (EMT). However, the molecular mechanisms underlying GBC progression are poorly understood. We found that serine threonine tyrosine kinase 1 (STYK1) was elevated in GBC and was negatively correlated with clinical outcomes and prognosis. Overexpression of STYK1 in GBC cell lines gave rise to increased cell proliferation, colony formation, migration and invasion, thus committing cells to undergoing EMT. In contrast, silence of STYK1 led to opposite effects on cell transformation. Consistent with STYK1 gene knockdown, AKT specific inhibitor MK2206 abrogated tumor promoting action induced by STYK1, suggesting that PI3K/AKT pathway is essential for the oncogenic role of STYK1 in GBC. STYK1 shRNA in GBC cells inhibited development of xenografted tumors compared with control cells. Collectively, our findings suggest that STYK1 is a critical regulator of tumor growth and metastasis, and may serve as a potential target for GBC therapy.

Epigenetic Downregulation of PTEN in Gallbladder Cancer.

PURPOSE: Gallbladder cancer (GBC) is becoming a global health problem. Phosphatase and tensin homolog (PTEN), also known as guardian gene of cancer, encodes a protein, which dephosphorylates phosphatidylinositol (3,4,5) triphosphate {PtdIns (3,4,5) P3 } into phosphatidylinositol (4,5) diphosphate {PtdIns (4,5) P2} that results in the inhibition of AKT/PKB signaling pathway. PTEN plays a key role in the pathogenesis of various cancers. However, its role in GBC is still obscure. The present study was aimed to identify the epigenetic role of PTEN in GBC and GSD. METHODS: PTEN promoter methylation was studied by methylation-specific PCR in 50 GBC and 30 GSD tissues. Transcript level expression of PTEN was analyzed by reverse transcriptase PCR and quantitative PCR in 20 GBC and 20 GSD tissue samples. Immunohistochemistry was performed on tissue microarrays of 136 GBC samples to correlate the methylation pattern with the pattern of in situ expression of PTEN protein. Student's t test was performed to test the significant level of difference between case and control samples. Values showing p ≤ 0.05 were considered significant. RESULTS: MS PCR showed PTEN promoter methylation in 30% (15/50) GBC (p = 0.0486) and 22.86% (8/30) GSD (p = 0.0530) cases. RT-PCR and qPCR revealed downregulation of PTEN in advanced GBC cases (p < 0.0001), but, not in GSD (p = 0.901). Immunohistochemistry of GBC tissue microarray scored 1+ in 20.29% (p = 0.0028) and zero or negative in 50% (p < 0.0001) GBC cores. CONCLUSIONS: Thus, PTEN may be considered as a useful biomarker for the management of GBC, however, needs larger sample size to validate it further.

AICAR activates ER stress-dependent apoptosis in gallbladder cancer cells.

AICAR (5-Aminoimidazole-4-carboxamide riboside or acadesine) is an AMP-activated protein kinase (AMPK) agonist, its activity in human gallbladder cancer cells was evaluated here. We show that AICAR provoked significant apoptosis in human gallbladder cancer cell lines (Mz-ChA-1, QBC939 and GBC-SD) and primary gallbladder cancer cells. AICAR-induced cytotoxicity in gallbladder cancer cells appears independent of AMPK activation. Inhibition of AMPK, via AMPKα shRNA knockdown or dominant negative mutation (T172A), failed to rescue GBC-SD cells from AICAR. Further, forced-activation of AMPK, by adding two other AMPK activators (A769662 and Compound 13), or expressing a constitutively-active mutant AMPKα (T172D), didn't induce GBC-SD cell death. Remarkably, AICAR treatment in gallbladder cancer cells induced endoplasmic reticulum (ER) stress activation, the latter was tested by caspase-12 activation, C/EBP homologous protein (CHOP) expression and IRE1/PERK phosphorylation. Contrarily, salubrinal (the ER stress inhibitor), z-ATAD-fmk (the caspase-12 inhibitor) or CHOP shRNAs significantly attenuated AICAR-induced gallbladder cancer cell apoptosis. Together, we conclude that AICAR-induced gallbladder cancer cell apoptosis requires ER stress activation, but is independent of AMPK.

MiR-31 regulates the cisplatin resistance by targeting Src in gallbladder cancer.

BACKGROUND: Gallbladder cancer (GBC) is a malignant tumor highly resistant to chemotherapy. MicroRNAs (miRNAs) are found extensively involved in modulation of carcinogenesis and chemoresistance. This study aimed to investigate cisplatin (DDP)-susceptibility regulated by expression of the miRNAs and underlying pathways in GBC. RESULTS: The microRNA-31 (miR-31) was selected by microarray due to the biggest fold change between DDP-resistant and parental cells. Ectopic overexpression of miR-31 decreased cell proliferation, viability and invasion capacity, but promoted apoptosis in DDP-resistant cells and in xenograft tumor models. Cell apoptosis and DDP-chemosensitivity was remarkably increased by knockdown of Src proto-oncogene (Src) expression, which was subsequently reversed by rescue of Src expression in miR-31-expressing cells. METHODS: The microarray was used to select the candidate miRNA in two DDP-resistant GBC cell lines. The effect of regulated expression of the miRNA on cell migration, invasion, proliferation and apoptosis was examined by wound healing, transwell assays, CCK-8 assays, colony formation and flow cytometry assays, respectively. Xenograft tumor models were used to validate the function of the downstream target. CONCLUSION: Our results demonstrated that miR-31reduced significantly in GBC cells rendering resistance to cisplatin, and upregulated expression of miR-31 augmented chemosensitivity, presenting a therapeutic potential to overcome drug resistance in GBC.

Desulfation of cell surface HSPG is an effective strategy for the treatment of gallbladder carcinoma.

Cell surface heparan sulfate proteoglycan (HSPG) is a group of critical glycoproteins that mediates signal transduction. Sulfated HSPG can mediate the activation of a variety of cell growth factor signal pathway to promote the progression of gallbladder carcinoma (GBC). This study analyzed 527 clinical GBC specimens and confirmed that the HSPG sulfation level was significantly higher in GBC tissues than in gallbladder mucosa (GBM) tissues. The high HSPG sulfation level was closely associated with poor differentiation, local metastasis, and advanced clinical stage of GBC; it was also associated with the shortening of disease-free survival (DFS) and overall survival (OS) and influenced the outcome of chemotherapy or radio-chemotherapy in patients with GBC recurrence. Inhibition of HSPG sulfation on the GBC cell surface using human sulfatase 1 (hSulf-1) significantly reduced the phosphorylation levels of growth factor receptors and signaling protein kinases in GBC cells, decreased cell responses to growth factors, and inhibited cell proliferation and migration abilities. In a nude mouse model with GBC xenografts, we observed that the xenograft tumor growth was suppressed and the phosphorylation levels of signaling proteins were downregulated, together with decreased expression of Ki67 and reduced sensitivity to bFGF (basic fibroblast growth factor) induction after inhibition of HSPG sulfation. Our study demonstrated that a high HSPG sulfation endows GBC with high malignant biological behaviors and a poor prognosis. Desulfation of cell surface HSPG can inhibit the kinase activities of a variety of signaling proteins, hinder the cell response to growth factors, and effectively inhibit the malignant biological behaviors of GBC cells.

Up-regulation of PKM2 promote malignancy and related to adverse prognostic risk factor in human gallbladder cancer.

Recently, pyruvate kinase M2 (PKM2) has been implicated in the progression of certain cancers and might play pivotal roles in the formation of malignancy. However, the role of PKM2 in gallbladder cancer had not been well investigated. This study analyzed associations between PKM2 expression status with various clinical and pathologic parameters in a large cohort of gallbladder cancer (GBC) patients from a long term follow up results. The expression level of pyruvate kinase isotypes in GBC tissues and their adjacent normal gallbladder tissues were estimated by qRT-PCR and Western blot. PKM2 mRNA level were significantly high in gallbladder cancer tissues than in adjacent noncancerous tissues (P < 0.001). High expression of the PKM2 was detected in 55.71% paraffin-embedded GBC tissue. The high PKM2 expression was independently associated with poorer overall survival in patients with GBC (median survival 11.9 vs 30.1 months; hazard ratio 2.79; 95% CI = 1.18 to 6.55; P = 0.02). These findings indicated elevated expression of PKM2 is a prognostic factor for poor GBC clinical outcomes, implied involving of PKM2 in GBC progression.

HDAC1 promoted migration and invasion binding with TCF12 by promoting EMT progress in gallbladder cancer.

The identification of prognostic markers for gallbladder cancer is needed for clinical practice. Histone deacetylases (HDACs) play an important role in tumor development and progression by modifying histone and non-histone proteins. However, the expression of HDAC1 in patients with gallbladder cancer is still unknown. Here, we reported that HDAC1 expression was elevated in cancerous tissue and correlated with lymph node metastasis and poorer overall survival in patients with GBC. Knockdown of HDAC1 using lentivirus delivery of HDAC1-specific shRNA abrogated the migration and invasion of GBC cells in vitro. TCF-12, as the HDAC1 binding protein, has also correlates with poor prognosis in GBC patients. And there is a positive correlation between HDAC1 and TCF-12 which leading the high invasion and migration ability of GBC cells. Taken together, our data suggested that HDAC1 and TCF-12 are a potential prognostic maker and may be a molecular target for inhibiting invasion and metastasis in GBC.

CD133 promotes gallbladder carcinoma cell migration through activating Akt phosphorylation.

Gallbladder carcinoma (GBC) is the fifth most common malignancy of gastrointestinal tract. The prognosis of gallbladder carcinoma is extremely terrible partially due to metastasis. However, the mechanisms underlying gallbladder carcinoma metastasis remain largely unknown. CD133 is a widely used cancer stem cell marker including in gallbladder carcinoma. Here, we found that CD133 was highly expressed in gallbladder carcinoma as compared to normal tissues. CD133 was located in the invasive areas in gallbladder carcinoma. Down-regulation expression of CD133 inhibited migration and invasion of gallbladder carcinoma cell without obviously reducing cell proliferation. Mechanism analysis revealed that down-regulation expression of CD133 inhibited Akt phosphorylation and increased PTEN protein level. The inhibitory effect of CD133 down-regulation on gallbladder carcinoma cell migration could be rescued by Akt activation. Consistent with this, addition of Akt inhibitor Wortmannin markedly inhibited the migration ability of CD133-overexpressing cells. Thus, down-regulation of CD133 inhibits migration of gallbladder carcinoma cells through reducing Akt phosphorylation. These findings explore the fundamental biological aspect of CD133 in gallbladder carcinoma progression, providing insights into gallbladder carcinoma cell migration.

LASP-1 induces proliferation, metastasis and cell cycle arrest at the G2/M phase in gallbladder cancer by down-regulating S100P via the PI3K/AKT pathway.

LASP-1 is an actin-binding protein that regulates cytoskeletal dynamics and cell migration. LASP-1 was previously identified in a cDNA library from metastatic breast cancer samples. This protein has since been detected in multiple human cancers, including liver cancer, gastric cancer and pancreatic cancer. S100P is a small calcium-binding protein in the S100 protein family that regulates cellular, physiological and pathological processes in various cancers. However, the clinical significance of LASP-1 and S100P expression in gallbladder cancer (GBC) is not yet clear. In our study, we focused on the clinical significance, biological function and mechanism of LASP-1 in gallbladder cancer and detected LASP-1 and S100P overexpression in GBC tissues. The expression of LASP-1 was significantly correlated with poor prognosis in GBC patients (P < 0.05). Furthermore, down-regulation of LASP-1 expression resulted in the obvious inhibition of proliferation and migration and caused cell cycle arrest by down-regulating S100P via the PI3K/AKT pathway; in mice, tumor volume was significantly decreased. In conclusion, LASP-1 may act as an oncogene to regulate the expression of S100P to influence cellular functions in GBC. LASP-1 could serve as a genetic treatment target in GBC patients.

Variants and haplotypes in Flap endonuclease 1 and risk of gallbladder cancer and gallstones: a population-based study in China.

The role of FEN1 genetic variants on gallstone and gallbladder cancer susceptibility is unknown. FEN1 SNPs were genotyped using the polymerase chain reaction-restriction fragment length polymorphism method in blood samples from 341 gallbladder cancer patients and 339 healthy controls. The distribution of FEN1-69G > A genotypes among controls (AA, 20.6%; GA, 47.2% and GG 32.2%) was significantly different from that among gallbladder cancer cases (AA, 11.1%; GA, 48.1% and GG, 40.8%), significantly increased association with gallbladder cancer was observed for subjects with both the FEN1-69G > A GA (OR = 1.73, 95% CI = 1.01-2.63) and the FEN1-69G > A GG (OR = 2.29, 95% CI = 1.31-3.9). The distribution of FEN1 -4150T genotypes among controls (TT, 21.8%;GT, 49.3% and GG 28.9%) was significantly different from that among gallbladder cancer cases (TT, 12.9%; GT, 48.4% and GG 38.7%), significantly increased association with gallbladder cancer was observed for subjects with both the FEN1-4150T GT(OR = 1.93, 95% CI = 1.04-2.91) and the FEN1-4150T GG(OR = 2.56, 95% CI = 1.37-5.39). A significant trend towards increased association with gallbladder cancer was observed with potentially higher-risk FEN1-69G > A genotypes (P < 0.001, χ2 trend test) and FEN14150G > T (P < 0.001, χ2 trend test) in gallstone presence but not in gallstone absence (P = 0.81, P = 0.89, respectively). In conclusion, this study revealed firstly that FEN1 polymorphisms and haplotypes are associated with gallbladder cancer risk.

Lysine-specific demethylase 1 promotes tumorigenesis and predicts prognosis in gallbladder cancer.

Gallbladder Cancer (GBC), characterized by invasive growth and infiltrative dissemination, is difficult to diagnose and has poor prognosis. Emerging evidence demonstrates that Lysine-Specific Demethylase 1 (LSD1) has important roles in carcinogenesis, proliferation and metastasis. We studied the roles and molecular mechanisms of LSD1 in GBC. We examined LSD1 expression in 109 paired samples of GBC and normal gallbladder tissues. We found GBC tissues had upregulated LSD1 compared with normal gallbladder tissues (P = 0.003), and its high expression was associated with tumor-node-metastasis stage (P < 0.0001), Nevin's stage (P = 0.0093) and distant metastases (P = 0.0070). We found positive correlations between LSD1 expression and other proteins: epithelial-mesenchymal transition markers, C-myc and cyclin-related proteins. Inhibiting LSD1 expression in vitro impaired the proliferation and invasiveness of GBC cells and also downregulated c-myc expression and consequently inhibited GBC cell proliferation. LSD1 overexpression promotes GBC development and may be a predictor for a worsened prognosis. LSD1 may be a novel therapeutic target and prognostic tool for gallbladder cancer.