Haibin Liang

Prohibitin overexpression predicts poor prognosis and promotes cell proliferation and invasion through ERK pathway activation in gallbladder cancer

AbstractBackgroundProhibitin (PHB), a pleiotropic protein overexpressed in several tumor types, has been implicated in the regulation of cell proliferation, invasive migration and survival. However, PHB expression and its biological function in gallbladder cancer (GBC) remain largely unknown.MethodsPHB and p-ERK protein expressions were determined in human GBC tissues by immunohistochemistry (IHC). The effects of PHB knockdown on GBC cell proliferation and invasiveness were evaluated using Cell Counting Kit-8 (CCK-8) cell viability, cell cycle analysis, transwell invasion and gelatin zymography assays. Subcutaneous xenograft and tail vein-lung metastasis tumor models in nude mice were employed to further substantiate the role of PHB in GBC progression.ResultsPHB protein was overexpressed in GBC tissues and was significantly associated with histological grade, tumor stage and perineural invasion. Furthermore, PHB expression was negatively associated with overall survival in GBC patients. In vitro experimental studies demonstrated that the downregulation of PHB expression by lentivirus-mediated shRNA interference not only inhibited the ERK pathway activation but also reduced the proliferative and invasive capacities of GBC cells. Moreover, PD0325901, a specific inhibitor of MEK, markedly impaired PHB- mediated phosphorylation of ERK protein. IHC statistical analyses further validated that PHB expression was positively correlated with ERK protein phosphorylation levels in GBC tissue samples. In vivo, PHB depletion also resulted in dramatic reductions in the growth and metastasis of GBC cells.ConclusionOur findings demonstrate that PHB overexpression predicts poor survival in GBC patients. PHB could serve as a novel prognostic biomarker and a potential therapeutic target for GBCs.

miR-101 targeting ZFX suppresses tumor proliferation and metastasis by regulating the MAPK/Erk and Smad pathways in gallbladder carcinoma

Gallbladder cancer (GBC), the most common malignancy of the bile duct, is highly aggressive and has an extremely poor prognosis, which is a result of early metastasis. As it is regulated being at multiple levels, the metastatic cascade in GBC is complex. Recent evidence suggests that microRNAs (miRNAs) are involved in cancer metastasis and are promising therapeutic targets. In this study, miR-101 was significantly downregulated in tumor tissues, particularly in metastatic tissues. In GBC patients, low miR-101 expression was correlated with tumor size, tumor invasion, lymph node metastasis, TNM stage, and poor survival. Moreover, miR-101 was an independent prognostic marker for GBC. Additionally, miR-101 inhibited GBC cell proliferation, migration, invasion, and TGF-β-induced epithelial-mesenchymal transition (EMT) in vitro and in vivo. Mechanistically, the gene encoding the zinc finger protein X-linked (ZFX) was identified as a direct target of miR-101. More importantly, miR-101 significantly reduced activation of the MAPK/Erk and Smad signaling pathways, resulting in inhibition of TGF-β-mediated induction of EMT. Altogether, our findings demonstrate a novel mechanism by which miR-101 attenuates the EMT and metastasis in GBC cells and suggest that miR-101 can serve as a potential biomarker and therapeutic target for GBC management.

A novel PI3K/AKT signaling axis mediates Nectin-4-induced gallbladder cancer cell proliferation, metastasis and tumor growth

Nectin-4 is a Ca(2+)-independent immunoglobulin-like cell adhesion molecule which has diverse functions in cell-cell adhesion via homophilic and heterophilic interactions. Cell-cell adhesive processes are central to cell polarization, differentiation, proliferation, survival and movement. Here we report that Nectin-4 is substantially overexpressed in gallbladder cancer (GBC), the most common biliary tract malignancy with a high risk of local tumor spread and invasion. Further, Nectin-4 high expression in GBC patients was associated with pathologic T stage and lymph node metastasis status, and the expression level of the downstream target Rac1 and poor prognoses were also correlated with Nectin-4. Ectopic expression of Nectin-4 promoted GBC cell growth, motility and tumor growth in a mouse model. The depletion of Nectin-4 inhibited GBC cell proliferation and migration both in cell culture and in mice. Our data suggest that activation of the PI3K/AKT pathway was involved in the oncogenic function of Nectin-4 to activate Rac1 in GBC. Inhibition of PI3K/AKT with LY294002 and/or Rac1 with NSC23766 impaired Nectin-4-mediated GBC cell proliferation and motility. We hypothesize that Nectin-4 is critical for GBC progression via PI3K/AKT pathway activation of Rac1. Nectin-4 may be a novel prognostic factor and therapeutic target in GBC patients.

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.

Dihydroartemisinin inhibits TCTP-dependent metastasis in gallbladder cancer

BackgroundPatients with metastatic or relapsed gallbladder cancer generally have a poor prognosis. Therefore, targeting metastasis is one arm of therapeutic strategies to treat gallbladder cancer.MethodsLevels of translationally controlled tumor protein (TCTP) were measured in samples of gallbladder cancer by immunohistochemical staining. Wound healing, migration and invasion assays were used to investigate the motility of cells. Western blot assay was used to investigate the levels of TCTP and other proteins. Liver metastasis models and lung metastasis models were established to investigate the inhibitory effect of Dihydroartemisinin on gallbladder cancer metastasis.ResultsTCTP is aberrantly expressed in gallbladder cancer patients and associated with metastasis and a poor prognosis. Depleting TCTP significantly inhibited gallbladder cancer cell migration and invasion. We found that Dihydroartemisinin as a potent inhibitor of TCTP inhibited TCTP-dependent cell migration and invasion by reducing cell division control protein 42 homolog (Cdc42) activation. In addition, in mice with xenografted tumors, treatment with Dihydroartemisinin decreased gallbladder cancer cell metastases and improved survival.ConclusionsThese findings provide new insights into the therapeutic activity of Dihydroartemisinin as a treatment for gallbladder cancer metastasis.

EIF3D promotes gallbladder cancer development by stabilizing GRK2 kinase and activating PI3K-AKT signaling pathway

Recent evidence suggests that dysregulated eIF3d expression may be critical in various genetic disorders as well as cancer. In this study, we observed that EIF3d levels increased in gallbladder cancer (GBC) samples compared with non-tumor tissue. High eIF3d levels were associated with advanced tumor stage and metastasis and were correlated with poor prognosis in 92 patients with GBC. Depletion of EIF3d in GBC cell lines inhibited cell proliferation, colony formation and metastasis and induced apoptosis and cell cycle arrest in vitro and in vivo. In contrast, ectopic expression of eIF3d had the opposite effects. Moreover, in this study, we revealed that a novel non-translational factor function of eIF3d mediated its protumoral effects. In details, eIF3d stabilizes GRK2 protein by blocking ubiquitin-mediated degradation, consequently activates PI3K/Akt signaling, and promotes GBC cell proliferation and migration. In conclusion, eIF3d promotes GBC progression mainly via eIF3d–GRK2–AKT axis and it may be used as a prognostic factor. The therapeutic targeting of eIF3d–GRK2 axis may be a potential treatment approach for GBC.

Dioscin Induces Gallbladder Cancer Apoptosis by Inhibiting ROS-Mediated PI3K/AKT Signalling

Gallbladder cancer (GBC), highly aggressive form of cancer with an extremely poor prognosis, is the most common malignancy of the biliary tract. In this study, we investigated the effects of dioscin (DSN) on human GBC and the potential mechanisms underlying these effects. The results showed that DSN significantly inhibited GBC cell proliferation and migration. Moreover, DSN induced GBC cell apoptosis via mitochondrial dependent apoptotic signalling. Reactive oxygen species (ROS) and glutathione (GSH) levels were measured, and ROS scavengers completely inhibited DSN-induced apoptosis and migration, indicating that ROS play an essential role in GBC progression. Western blot analysis showed that AKT activity was significantly downregulated after DSN treatment, and that inhibition/ectopic expression of AKT enhanced/abolished DSN-induced apoptosis but not migration. Furthermore, we confirmed the relationship between ROS and the PI3K/AKT pathway and found that DSN induced apoptosis by regulating ROS-mediated PI3K/AKT signaling. Taken together, these findings indicate that DSN induces GBC apoptosis through inhibiting ROS-mediated PI3K/AKT signalling.

A three-step method for modular lymphadenectomy in gastric cancer surgery: The ability to retrieve sufficient lymph nodes and improve survival

BACKGROUND Systematic lymphadenectomy for the resection of sufficient lymph nodes is the most important part of curative resection in gastric cancer surgery. Here, we explore the outcomes of the three-step method for modular lymphadenectomy (TSMML) and determine its safety and efficacy, compared with the conventional method for lymphadenectomy (CML). METHODS From 2008 to 2011, 270 patients with gastric cancer were divided into 2 subgroups: the TSMML group and the CML group. RESULTS Patients in the TSMML group had a significantly higher median number of retrieved lymph nodes (rLNs), lower median metastatic lymph node ratios (MLRs), and superior 5-year relapse-free survival (RFS) than the CML group. Moreover, the use of the TSMML procedure was an independent protective factor for RFS. No significant intergroup differences were found in morbidity or mortality in these two groups. CONCLUSION The TSMML procedure is safe and effective and is easy to learn.

E2F1 and E2F7 differentially regulate KPNA2 to promote the development of gallbladder cancer

Karyopherin alpha 2 (KPNA2) is a nuclear import factor that is elevated in multiple cancers. However, its molecular regulation at the transcriptional levels is poorly understood. Here we found that KPNA2 was significantly upregulated in gallbladder cancer (GBC), and the increased levels were correlated with short survival of patients. Gene knocking down of KPNA2 inhibited tumor cell proliferation and migration in vitro as well as xenografted tumor development in vivo. A typical transcription factor E2F1 associated with its DNA-binding partner DP1 bond to the promoter region of KPNA2 and induced KPNA2 expression. In contrast, an atypical transcription factor E2F7 competed against DP1 and blocked E2F1-induced KPNA2 gene activation. Mutation of the dimerization residues of E2F7 or DNA-binding domain of E2F1 abolished the suppressive effects of E2F7 on KPNA2 gene expression. In addition, KPNA2 mediated nuclear localization of E2F1 and E2F7, where they in turn controlled KPNA2 expression. Taken together, our data provided mechanistic insights into divergently transcriptional regulation of KPNA2, thus pointing to KPNA2 as a potential target for cancer therapy.

EMP3, which is regulated by miR-663a, suppresses gallbladder cancer progression via interference with the MAPK/ERK pathway

Gallbladder cancer (GBC) is the most common malignancy of the biliary tract and its molecular pathogenesis is poorly understood. Aberrant expression of epithelial membrane protein-3 (EMP3) was reported in different kinds of cancers. Our study aimed to explore the elusive functional roles and the underlying molecular mechanisms of EMP3 with respect to GBC progression. The results showed that human GBC tissues exhibited decreased levels of EMP3 compared with non-malignant tissues. Kaplan-Meier analysis indicated that low expression of EMP3 was associated with poor prognosis of GBC patients. Upregulation of EMP3 repressed GBC cell proliferation, migration and invasion both in vitro and in vivo. Conversely, EMP3 silencing promoted GBC cell growth and metastasis. Additionally, we found that EMP3 was a target gene of miR-663a, and downregulation of EMP3 in GBC was attributed to the overexpression of miR-663a. Furthermore, miR-663a was proven to be a tumor-promoting factor mediating GBC development. Finally, we demonstrated that downregulation of EMP3 activated MAPK/ERK signaling, which modulated GBC progression. These data showed the mechanism by which EMP3 suppresses GBC progression, suggesting that the miR-663a/EMP3/MAPK/ERK axis may be a novel therapeutic target for GBC treatment.