Baiyong Shen

Survey of Tyrosine Kinase Signaling Reveals ROS Kinase Fusions in Human Cholangiocarcinoma

Cholangiocarcinoma, also known as bile duct cancer, is the second most common primary hepatic carcinoma with a median survival of less than 2 years. The molecular mechanisms underlying the development of this disease are not clear. To survey activated tyrosine kinases signaling in cholangiocarcinoma, we employed immunoaffinity profiling coupled to mass spectrometry and identified DDR1, EPHA2, EGFR, and ROS tyrosine kinases, along with over 1,000 tyrosine phosphorylation sites from about 750 different proteins in primary cholangiocarcinoma patients. Furthermore, we confirmed the presence of ROS kinase fusions in 8.7% (2 out of 23) of cholangiocarcinoma patients. Expression of the ROS fusions in 3T3 cells confers transforming ability both in vitro and in vivo, and is responsive to its kinase inhibitor. Our data demonstrate that ROS kinase is a promising candidate for a therapeutic target and for a diagnostic molecular marker in cholangiocarcinoma. The identification of ROS tyrosine kinase fusions in cholangiocarcinoma, along with the presence of other ROS kinase fusions in lung cancer and glioblastoma, suggests that a more broadly based screen for activated ROS kinase in cancer is warranted.

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.

Amplification of Long Noncoding RNA ZFAS1 Promotes Metastasis in Hepatocellular Carcinoma

Despite progress in the diagnostics and treatment of hepatocellular carcinoma (HCC), its prognosis remains poor. In this study, we globally assessed long noncoding RNAs (lncRNA) for contributions to HCC using publicly available microarray data, in vitro and in vivo assays. Here, we report that ZFAS1, encoding a lncRNA that is frequently amplified in HCC, is associated with intrahepatic and extrahepatic metastasis and poor prognosis of HCC. ZFAS1 functions as an oncogene in HCC progression by binding miR-150 and abrogating its tumor-suppressive function in this setting. miR-150 repressed HCC cell invasion by inhibiting ZEB1 and the matrix metalloproteinases MMP14 and MMP16. Conversely, ZFAS1 activated ZEB1, MMP14, and MMP16 expression, inhibiting these effects of miR-150. Our results establish a function for ZFAS1 in metastatic progression and suggest its candidacy as a new prognostic biomarker and target for clinical management of HCC.

Downregulation of gas5 increases pancreatic cancer cell proliferation by regulating CDK6

Recent studies have revealed that long non-coding RNAs (lncRNAs) play important roles in cancer biology and that lncRNA gas5 (growth arrest-specific 5) regulates breast cancer cell growth. However, the role of gas5 in pancreatic cancer progression remains largely unknown. In the current study, we assay the expression level of gas5 in pancreatic cancer tissues and define the role of gas5 in the regulation of pancreatic cancer cell proliferation. We verify that the expression level of gas5 is significantly decreased in pancreatic cancer tissues compared with normal control. Overexpression of gas5 in pancreatic cancer cells inhibits cell proliferation, whereas gas5 inhibition induces a significant decrease in G0/G1 phase and an increase in S phase. We further demonstrate that gas5 negatively regulates CDK6 (cyclin-dependent kinase 6) expression in vitro and in vivo. More importantly, knockdown of CDK6 partially abrogates gas5-siRNA-induced cell proliferation. These data suggest an important role of gas5 in the molecular etiology of pancreatic cancer and implicate the potential application of gas5 in pancreatic cancer therapy.

Snail Recruits Ring1B to Mediate Transcriptional Repression and Cell Migration in Pancreatic Cancer Cells

Transcriptional repressor Snail is a master regulator of epithelial-mesenchymal transition (EMT), yet the epigenetic mechanism governing Snail to induce EMT is not well understood. Here, we report that in pancreatic ductal adenocarcinoma (PDAC), elevated levels of the ubiquitin E3 ligase Ring1B and Snail, along with elevated monoubiquitination of H2A at K119 (H2AK119Ub1), are highly correlated with poor survival. Mechanistic investigations identified Ring1B as a Snail-interacting protein and showed that the carboxyl zinc fingers of Snail recruit Ring1B and its paralog Ring1A to repress its target promoters. Simultaneous depletion of Ring1A and Ring1B in pancreatic cancer cells decreased Snail binding to the target chromatin, abolished H2AK119Ub1 modification, and thereby compromised Snail-mediated transcriptional repression and cell migration. We found that Ring1B and the SNAG-associated chromatin modifier EZH2 formed distinct protein complexes with Snail and that EZH2 was required for Snail-Ring1A/B recruitment to the target promoter. Collectively, our results unravel an epigenetic mechanism underlying transcriptional repression by Snail, suggest Ring1A/B as a candidate therapeutic target, and identify H2AK119Ub1 as a potential biomarker for PDAC diagnosis and prognosis.

Role of splanchnic hemodynamics in liver regeneration after living donor liver transplantation

The aim of this study was to investigate the changes in splanchnic hemodynamics after LDLT and their relationship with graft regeneration. Eighteen patients with LDLT December 2006 and June 2008 were enrolled, and color Doppler ultrasonography was performed preoperatively and on postoperative days (PODs) 1, 3, 5, 7, 30, and 90 after transplantation. The changes in the portal blood flow mean velocity (PBV) and portal blood flow volume (PBF) were monitored, and their effects on hepatic function were observed simultaneously. Graft sizes were measured on PODs 7, 30, and 90 after the operation. The regeneration rates of grafts were calculated. PBF increased in the recipient group from 1081.17 ± 277.50 to 2171.44 ± 613.15 mL/minute, and PBV increased from 15.01 ± 5.67 to 56.00 ± 22.11 cm/s; they were both significantly higher than those in the donor group (P < 0.01). On POD 1, serum aspartic aminotransferase, alanine aminotransferase, and total bilirubin all peaked; however, these indices in patients with PBF/graft weight (GW) > 300 mL/minute · 100 g were significantly higher than those in patients with PBF/GW < 300 mL/minute · 100 g. Livers in the recipient group regenerated rapidly. The graft regeneration rate reached 119.40% ± 28.21% as early as 1 month post‐transplantation. PBF and PBV on PODs 1 and 3 were greatly related to liver regeneration at 30 days. The portal venous flow in patients with portal hypertension after LDLT showed a high perfusion state, which could promote graft regeneration, but PBF/GW after the operation should be controlled below 300 mL/minute · 100 g in order to protect grafts from hyperperfusion injury. Liver Transpl 15:1043–1049, 2009.

Robotic-assisted pancreatic resection: a report of 47 cases

There are few reports of robot‐assisted pancreatic surgery. Our purpose was to report our surgical and clinical experiences and outcomes of 47 cases of robot‐assisted pancreatic resection to show that minimally invasive pancreatic surgery is both feasible and effective.

Solid-pseudopapillary tumor of the pancreas: Clinical features, pathological characteristics, and origin†‡§

To study clinically pathological features and origin of solid‐pseudopapillary tumor of pancreas (SPT).

miR-150-5p Inhibits Hepatoma Cell Migration and Invasion by Targeting MMP14

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. Despite progress in diagnostics and treatment of HCC, its prognosis remains poor because the molecular mechanisms underlying hepatocarcinogenesis are not well understood. In the study, we focused on identifying the role of miRNAs in HCC progression. miRNA microarray was used to analyze the differentially expressed miRNAs, and the results were validated by qPCR. We found that the miR-150-5p expression is down-regulated in HCC tissues compared with pair non-tumor tissues. miR-150-5p expression is also decreased in metastatic cancer tissues compared with pair primary tissues, indicating that miR-150-5p may be involved in HCC metastasis. Functionally, miR-150-5p inhibition significantly promotes hepatoma cell migration and invasion, whereas miR-150-5p overexpression suppresses cancer cell migration and invasion in vitro. The matrix metalloproteinase 14 (MMP14) is identified as a new target gene of miR-150-5p. miR-150-5p markedly inhibits MMP14 expression in hepatoma cells, and miR-150-5p expression is negative correlation with MMP14 expression in vivo. More important, re-expression of MMP14 in hepatoma cells partially reverses the effect of miR-150-5p in inhibiting cell invasion.

Pharmacokinetics of mycophenolic acid and determination of area under the curve by abbreviated sampling strategy in Chinese liver transplant recipients.

ObjectivesThis study aimed to: (i) define the clinical pharmacokinetics of mycophenolic acid (MPA) in Chinese liver transplant recipients; and (ii) develop a regression model best fitted for the prediction of MPA area under the plasma concentration-time curve from 0 to 12 hours (AUC12) by abbreviated sampling strategy.MethodsForty liver transplant patients received mycophenolate mofetil 1g as a single dose twice daily in combination with tacrolimus. MPA concentrations were determined by high-performance liquid chromatography before dose (C0) and at 0.5 (C0.5), 1 (C1), 1.5 (C1.5), 2 (C2), 4 (C4), 6 (C6), 8 (C8), 10 (C10) and 12 (C12) hours after administration on days 7 and 14. A total of 72 pharmacokinetic profiles were obtained. MPA AUC12 was calculated with 3P97 software. The trough concentrations (C0) of tacrolimus and hepatic function were also measured simultaneously. Multiple linear regression analysis was used to establish the models for estimated MPA AUC12. The agreement between predicted MPA AUC12 and observed MPA AUC12 was investigated by Bland-Altman analysis.ResultsThe pattern of MPA concentrations during the 12-hour interval on day 7 was very similar to that on day 14. In the total of 72 profiles, the mean maximum plasma concentration (Cmax) and time to reach Cmax (tmax) were 9.79 ± 5.26 mg/L and 1.43 ± 0.78 hours, respectively. The mean MPA AUC12 was 46.50 ± 17.42 mg · h/L (range 17.99–98.73 mg · h/L). Correlation between MPA C0 and MPA AUC12 was poor (r2 = 0.300, p = 0.0001). The best model for prediction of MPA AUC12 was by using 1, 2, 6 and 8 hour timepoint MPA concentrations (r2 = 0.921, p = 0.0001). The regression equation for estimated MPA AUC12 was 5.503 + 0.919 · C1 + 1.871 · C2 + 3.176 · C6 + 3.664 · C8. This model had minimal mean prediction error (1.24 ± 11.19%) and minimal mean absolute prediction error (8.24 ± 7.61%). Sixty-three of 72 (88%) estimated MPA AUC12 were within 15% of MPA AUC12. Bland-Altman analysis also revealed the best agreement of this model compared with the others and a mean error of ±9.89 mg · h/mL.ConclusionThis study showed the wide variability in MPA AUC12 in Chinese liver transplant recipients. Single timepoint MPA concentration during the 12-hour dosing interval cannot reflect MPA AUC12. MPA AUC12 could be predicted accurately using 1, 2, 6 and 8 hour timepoint MPA concentrations by abbreviated sampling strategy.