Self-Consistent Quantum Mechanics/Embedded Charge Study on Aggregation-Enhanced Delayed Fluorescence of Cu(I) Complexes: Luminescence Mechanism and Molecular Design Strategy.

To elucidate the luminescence mechanism of highly efficient blue Cu(N^N)(POP)+-type thermally activated delayed fluorescence (TADF) materials, we have selected Cu(pytfmpz)(POP)+ (1) and Cu(pympz)(POP)+ (2) as targets to investigate the photophysical properties in both solution and solid phases. The self-consistent electrostatic potential (ESP) embedded charge within the quantum mechanics/molecular mechanics (QM/MM) method demonstrates a greater advantage over the charge equilibrium (QEQ) in accurately calculating atomic charges and reasonably describing the polarization effect, ultimately resulting in a favorable consistency between simulation and experimental measurements. After systematic and quantitative simulation, it has been found that complex 2, with an electron-donating group of -CH3, exhibits a much more blue-shifted spectrum and a significantly enhanced efficiency in comparison to complex 1 with -CF3. This is due to the widened HOMO-LUMO gap as well as the narrowed energy gap between the lowest singlet and triplet excited states (ΔEST), respectively. Then, the designed complex 3 is introduced with a stronger electron donor and larger tert-butyl group, which plays a key role in simultaneously suppressing the structural distortion and reducing the ΔEST. This leads to a faster reverse intersystem crossing process than that of the two experimental complexes in solution, turning out to be a new deep-blue-emitting material with excellent TADF performance.

Two new N-acetyl-á´ -glucosamine derivatives from the medical algae-derived endophytic fungus Penicillium chrysogenum.

Two new N-acetyl-ᴅ-glucosamine derivatives, penichryfurans A (1) and B (2), were obtained from the fermentation of an endophytic fungus Penicillium chrysogenum which inhabited the marine medical red alga Grateloupia turuturu. Their structures were established by detailed spectroscopic analysis of 1D and 2D NMR in combination with HRESIMS data. The absolute configurations were determined by the (Mo2(OAc)4)-induced CD and comparison of the calculated and experimental electronic curcular dichroism (ECD) spectra. Both compounds were evaluated for their in vitro cytotoxic activities against A549, HeLa, and HepG2 cell lines, among which compound 1 exhibited strong cytotoxicity towards the HepG2 cell line with an IC50 value of 9.0 µM.

From luminescence quenching to high-efficiency phosphorescence: a theoretical study on the monomeric and dimeric forms of platinum(II) complexes with both 2-pyridylimidazol-2-ylidene and bipyrazolate chelates.

To develop solid-state light-emitting materials with high luminescence efficiency, determining the potential photophysics and luminescence mechanisms of the aggregation state remains a challenge and a priority. Here, we apply density functional theory to study the photophysical properties of a series of square planar Pt(ii) complexes in both monomeric and dimeric forms. We reveal that four monomeric Pt(ii) complexes are dominated by triplet ligand-to-ligand charge-transfer, and the lack of the triplet metal-to-ligand charge-transfer feature results in weak spin-orbit coupling (SOC), which leads to limited radiative rates; moreover, calculated nonradiative transition rates are one or two orders of magnitude higher than those radiative rates because a large amount of reorganization energy caused by the vibration of the bipyrazolate (bipz) ligand cannot be readily suppressed in the monomeric form. Therefore, four monomers exhibit photoluminescence quenching in CH2Cl2 solution in both theoretical calculations and experiments. However, in the solid state, the intense luminescence phenomenon indicates obviously distinct properties between the monomer and aggregation. We carried out a dimer model to interpret that the interaction of PtPt induces a metal-metal-to-ligand charge-transfer excimeric state, which leads more metal components to participate in the charge transfer and enhance the SOC effect. At the same time, the ligand vibration can be significantly reduced by the shortened distance, and there is a strong π-π packing interaction in the dimer; thus, an excellent quantum yield can be achieved in aggregation. In addition, we disclose that introducing bulky substituents bearing electron-donating groups at R' and R'' positions have little effect on the properties of the monomers; however, there is a benefit of restricting the internal reorganization energy through the intermolecular interaction when packing in the solid state. Therefore, substitutions can be tuned to improve the properties of monomers (such as emission energy and reorganization energy). We hope that our work will shine some light on Pt(ii) emitters in the fabrication of efficient OLEDs.

Impact of ΔEST on Delayed Fluorescence Rate, Lifetime, and Intensity Ratio of Tetrahedral Cu(I) Complexes: Theoretical Simulation in Solution and Solid Phases.

Profound understanding of the luminescence mechanism and structure-property relationship is vital for Cu(I) thermally activated delayed fluorescence (TADF) emitters. Herein, we theoretically simulated luminescent behavior in both solution and solid phases for two Cu(I) complexes and found the following: (i) The strengthened spin-orbit coupling (SOC) effect by more dx2-y2 orbital contributions and well-restricted structural distortion via remarkable intramolecular interaction in [Cu(dmp)(POP)]+ enable the emission at room temperature to be a mixture of direct phosphorescence (10%) and TADF (90%). (ii) Benefiting from enhanced steric hindrance and the electron-donating ability of the paracyclophane group, the narrowed S1-T1 energy separation (ΔEST) in [Cu(dmp)(phanephos)]+ accelerates the reverse intersystem crossing, promoting the TADF rate (1.88 × 105 s-1) and intensity ratio (98.3%). These results indicate that the small ΔEST is superior for reducing the lifetime and that the strong SOC stimulates the phosphorescence to compete with TADF, which are both conducive to avoiding collision-induced exciton quenching and reducing the roll-off in devices.

Cdc42 subcellular relocation in response to VEGF/NRP1 engagement is associated with the poor prognosis of colorectal cancer.

Microscopic indications of malignancy and hallmark molecules of cancer are pivotal to determining cancer patient prognosis and subsequent medical intervention. Here, we found that compared to apical expression of Cdc42, which indicated that basal expression of Cdc42 occurred at the migrating cell front, glandular basal expression of Cdc42 (cell division cycle 42) in tissues indicated poorer prognoses for colorectal cancer (CRC) patients. The current study shows that activated Cdc42 was rapidly recruited to the migrating CRC cell front after VEGF stimulation through engagement of membrane-anchored neuropilin-1 (NRP1). When VEGF signalling was blocked with NRP1 knockdown or ATWLPPR (A7R, antagonist of VEGF/NRP1 interaction), Cdc42 activation and relocation to the cell front was attenuated, and filopodia and invadopodia formation was inhibited. The VEGF/NRP1 axis regulates directional migration, invasion, and metastasis through Cdc42 activation and relocation resulting from actin filament polymerisation of the extensions of membrane protrusions. Collectively, the immuno-micromorphological pattern of subcellular Cdc42 at the cell front indicated aggressive behaviours and predicted poor prognosis in CRC patients. Disruption of the intra- and extracellular interactions of the VEGF/NRP1 axis or Cdc42 relocation could be performed in clinical practice because it might inhibit cancer cell motility and metastasis.

Effects of miR-489 targeting on SOX4 gene on proliferation and apoptosis of human hepatocellular carcinoma cells.

BACKGROUND: Hepatocellular carcinoma is one of the most common malignant tumors found all over the globe. Despite advances in surgery and chemotherapy, the five-year survival rate of patients with hepatocellular carcinoma is still low. It is known that the proliferation of hepatocellular carcinoma cells is closely related to the occurrence, development and prognosis of hepatocellular carcinoma. The present work investigates the expression of microRNA-489 (miR-489) in human hepatocellular carcinoma cells and its effect on the biological behavior of human hepatocellular carcinoma cells. METHODS: The expression of miR-489 by fluorescence quantitative PCR detection in 30 patients with hepatoblastoma of liver cancer tissues and adjacent tissues was studied. Also, the determination of hepatoblastoma in four cell lines with different metastatic potential (HR8348, HCT116, HT29 and HEPG2) and the expression of miR-489 during miR-489 simulation process was studied. MTT assay, flow cytometry and Western blot analysis were performed to know the cell proliferation to detect the changes in cell cycle, apoptosis of cells, and SOX4 gene expression respectively. RESULTS: RT-PCR results showed that the cells compared with pre-cancerous tissue, the expression level of miR-489 in hepatocellular carcinoma tissues than in adjacent tissue significantly decreased (P<0.05), and with liver cancer cell metastasis increased (P<0.05); analogue transfection constructed miR-489 overexpressing HEPG2 cell line by microRNA. MTT results showed that miR-489 can inhibit the proliferation of HEPG2 cells, the differences were statistically significant (P<0.05); flow cytometry results showed that miR-489 mimics was transfected into HEPG2 cells at 48 hours had no significant effect on cell cycle distribution (P > 0.05); but miR-489 expression could induce apoptosis, compared with the control group, the apoptosis of miR-489 mimics was significantly increased and the difference was statistically significant (P < 0.05). CONCLUSION: In conclusion, miR-489 can significantly inhibit the occurrence and development of hepatocellular carcinoma cells. The mechanism may be down regulated by the expression of SOX4 and inhibit cell proliferation. Further this study showed that the tumor cells SOX4 gene as a regulatory factor target the genes of miR-489 in hepatocellular carcinoma.

Effects of hepatic blood inflow on liver ultrastructure and regeneration after extensive liver resection in rats with cirrhosis.

The aim of the present study was to investigate the effects of hepatic blood inflow on liver function, liver ultrastructure and the regeneration of future liver remnant (FLR) following major hepatectomy in rats with liver cirrhosis. A rat model of cirrhosis was established through intraperitoneal injection of carbon tetrachloride for 8 consecutive weeks. Extensive liver resection and different blood inflow models by portal vein (PV) and/or hepatic artery (HA) stenosis were conducted on the cirrhosis rats. Animal models were constructed as follows: Control (group A), low-flow PV + high-flow HA (group B), low-flow PV + low-flow HA (group C), high-flow PV + high-flow HA (group D) and high-flow PV + low-flow HA (group E). Hepatic blood inflow was detected by laser speckle contrast analysis, liver function and pathological changes were analyzed, Masson staining was used to identify the fibrosis of the liver and Periodic acid-Schiff staining was used to identify glycogen synthesis and hepatocyte function. The liver cell ultrastructure was evaluated by transmission electron microscopy, and the expression of Ki-67 in hepatocytes and the weight of the FLR were recorded to determine the regeneration of the FLR. Five days after major hepatectomy and liver blood inflow modulation, pathological examination of the livers from groups B and C revealed less congestion and less extensive hepatocellular injury. The serum alanine aminotransferase level of group B at 1, 3 and 5 days after hepatectomy and blood inflow modulation was 460.9±31.7, 331.0±22.0 and 285.6±15.8 U/l, respectively (control group: 676.9±41.7, 574.9±28.0 and 436.1±32.7 U/l, respectively; P<0.05); the total bilirubin of group B at 1, 3 and 5 days was 20.4±1.5, 16.1±1.0 and 13.5±0.6 µmol/l, respectively (control group: 30.3±1.4, 26.5±0.8 and 22.1±1.2 µmol/l, respectively; P<0.05). The size of the endoplasmic reticulum in the low-flow PV groups increased significantly and the mitochondrial swelling was alleviated. The positive rate of Ki-67 in the hepatocytes of groups B, C and D was 23.9±3.6, 15.7±2.3 and 12.9±2.4%, respectively (control group: 10.1±2.1%, P<0.05), and the positive rate of Ki-67 in group E was 6.1±1.4% (compared with that of the control group, P<0.05). The remnant liver weight of group B was 15.4±1.0 g (compared with that of the control group, P<0.05). Therefore, decreased portal blood flow combined with increased hepatic arterial blood flow alleviated the congestion in the liver following major hepatectomy in cirrhotic rats, improved the pathological status and liver function, increased the expression of Ki-67 and promoted liver regeneration.

[Relationships of glucose transporter 4 with cognitive changes induced by high fat diet and glucose metabolism in hippocampus].

The hippocampus not only plays a role in appetite and energy balance, but also is particularly important in learning and memory. Figuring out the relationships of hippocampal glucose transporter 4 (GLUT4) with hippocampal glucose metabolism and hippocampus-dependent cognitive function is very important to clearly understand the pathophysiological basis of nutritional obesity and diabetes-related diseases, and treat obesity and cognitive dysfunction. Therefore, this study reviewed recent researches conducted on hippocampal GLUT4, hippocampal glucose metabolism, and hippocampus-dependent cognitive function. In this review, we mainly discussed: (1) The structure of GLUT4 and the distribution and function of GLUT4 in the hippocampus; (2) The translocation of GLUT4 in the hippocampus; (3) The relationships of the PI3K-Akt-GLUT4 signaling pathway with the high fat diet-induced changes of cognitive function and the glucose metabolism in the hippocampus; (4) The associations of the PI3K-Akt-GLUT4 signaling pathway with the diabetes-related cognitive dysfunction in the hippocampus; (5) The potential mechanisms of cognitive dysfunction induced by glucose metabolic disorder.

The signaling mechanisms of hippocampal endoplasmic reticulum stress affecting neuronal plasticity-related protein levels in high fat diet-induced obese rats and the regulation of aerobic exercise.

High fat diet (HFD)-induced obesity has been shown to reduce the levels of neuronal plasticity-related proteins, specifically brain-derived neurotrophic factor (BDNF) and synaptophysin (SYN), in the hippocampus. However, the underlying mechanisms are not fully clear. Endoplasmic reticulum stress (ERS) has been reported to play a key role in regulating gene expression and protein production by affecting stress signaling pathways and ER functions of protein folding and post-translational modification in peripheral tissues of obese rodent models. Additionally, HFD that is associated with hyperglycemia could induce hippocampal ERS, thus impairing insulin signaling and cognitive health in HFD mice. One goal of this study was to determine whether hyperglycemia and hyperlipidemia could cause hippocampal ERS in HFD-induced obese SD rats, and explore the potential mechanisms of ERS regulating hippocampal BDNF and SYN proteins production. Additionally, although regular aerobic exercise could reduce central inflammation and elevate hippocampal BDNF and SYN levels in obese rats, the regulated mechanisms are poorly understood. Nrf2-HO-1 pathways play roles in anti-ERS, anti-inflammation and anti-apoptosis in peripheral tissues. Therefore, the other goal of this study was to determine whether aerobic exercise could activate Nrf2-HO-1 in hippocampus to alleviate obesity-induced hippocampal ERS, which would lead to increased BDNF and SYN levels. Male SD rats were fed on HFD for 8weeks to establish the obese model. Then, 8weeks of aerobic exercise treadmill intervention was arranged for the obese rats. Results showed that HFD-induced obesity caused hyperglycemia and hyperlipidemia, and significantly promoted hippocampal glucose transporter 3 (GLUT3) and fatty acid transport protein 1 (FATP1) protein expression. These results were associated with the activation of hippocampal ERS and ERS-mediated apoptosis. At the same time, we found that excessive hippocampal ERS not only significantly decreased proBDNF-the precursor of mature BDNF, but also attenuated p38/ERK-CREB signaling pathways and activated NLRP3-IL-1ß pathways in obese rats. These results were associated with reduced BDNF and SYN protein production. However, these adverse changes were obviously reversed by aerobic exercise intervention through activating the Nrf2-HO-1 pathways. These results suggest that dietary obesity could induce hippocampal ERS in male SD rats, and excessive hippocampal ERS plays a critical role in decreasing the levels of BDNF and SYN. Moreover, aerobic exercise could activate hippocampal Nrf2 and HO-1 to relieve ERS and heighten BDNF and SYN production in obese rats.

Surgical treatment of huge hepatocarcinoma with invasion or severe adhesion of diaphragm using the technique of orthotopic liver resection.

BACKGROUND/AIMS: To explore the clinical application and significance of the technique of orthotopic liver resection. METHODOLOGY: From January 2004 to December 2011, five patients with huge hepatocellular carcinoma with invasion or severe adhesion of diaphragm were undergone right semi-liver resection using the technique of orthotopic liver resection. The right hemi-liver was isolated from the first liver portal, second liver portal and third liver portal, then isolated from the normal liver, finally the tumor and the invaded diaphragm were resected or removed from the severe adhesion. The approach to hepatic resection involved routine use of Peng's multifunctional operative dissector, selective control of in and out-flow of liver, control of inferior vena cava (IVC) and liver hanging maneuver, anterior approach, etc. RESULTS: The operations were successfully performed in 5 patients. Operative time was 120, 180, 150, 150 and 160 min, respectively. The amount of blood loss were 350, 350, 400, 450, 600 ml, respectively. Postoperative complications were pleural effusion in 3 cases, and other 2 cases recovered without complications. CONCLUSIONS: Although the technique of orthotopic liver resection has a high technical requirement for surgeons, it provides a surgical method and operative opportunity for the patients whose tumor has invaded diaphragm or has been severe adhesion with diaphragm and conventional liver resection cannot be performed.

The effects of dan-shen root on cardiomyogenic differentiation of human placenta-derived mesenchymal stem cells.

The aim of this study was to search for a good inducer agent using for cardiomyogenic differentiation of stem cells. Human placenta-derived mesenchymal stem cells (hPDMSCs) were isolated and incubated in enriched medium. Fourth passaged cells were treated with 10mg/L dan-shen root for 20 days. Morphologic characteristics were analyzed by confocal and electron microscopy. Expression of α-sarcomeric actin was analyzed by immunohistochemistry. Expression of cardiac troponin-I (TnI) was analyzed by immunohistofluorescence. Atrial natriuretic factor (ANF) and beta-myocin heavy chain (ß-MHC) were detected by reverse transcriptase polymerase chain reaction (RT-PCR). hPDMSCs treated with dan-shen root gradually formed a stick-like morphology and connected with adjoining cells. On the 20th day, most of the induced cells stained positive with α-sarcomeric actin and TnI antibody. ANF and ß-MHC were also detected in the induced cells. Approximately 80% of the cells were successfully transdifferentiated into cardiomyocytes. In conclusion, dan-shen root is a good inducer agent used for cardiomyogenic differentiation of hPDMSCs.

[Risk factors and prognosis for patients with residual tumor after radiofrequency ablation of hepatocellular carcinoma].

OBJECTIVE: To investigate the risk factors and prognosis of patients with residual tumor after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). METHODS: The clinicopathological data of 114 patients with HCC undergoing RFA in our hospital from May 2000 to March 2007 were retrospectively studied, and the prognostic factors of residual tumor were analyzed. RESULTS: After one session of RFA, 90 patients had complete ablation and 24 had residual tumor. The median overall survivals in the complete ablation group and residual tumor group were 40 and 29 months, respectively. There was no statistically significant difference between those two groups (P = 0.242). 24 patients with residual tumor were re-treated by RFA or hepatectomy or TACE. Among them 11 patients achieved complete response and 13 incomplete response, their median overall survival were 53 and 28 months, respectively. There was no significant difference between first complete ablation group and second complete response group (P = 0.658). However, compared with the first complete ablation group, the incomplete response group had poor prognosis (P = 0.012). Multivariate analysis showed that tumor size > 3 cm (P = 0.007) and proximity to a large vessel (P = 0.042) were independent risk factors for residual tumor after RFA. CONCLUSION: Tumor size > 3 cm and proximity to a large vessel are independent risk factors for residual tumor after RFA. Further treatment of residual tumor is necessary to eliminate the tumor and improve prognosis.

Solid pseudopapillary tumor of the pancreas: a review of 553 cases in Chinese literature.

AIM: To sum up the clinical and pathological characteristics of solid pseudopapillary tumor (SPT) and the experience with it. METHODS: A total of 553 SPT patients reported in Chinese literature between January 1996 and January 2009 were retrospectively reviewed and analyzed. RESULTS: The mean age of the 553 SPT patients included in this review was 27.2 years, and the male to female ratio was 1:8.37. Their symptoms were non-specific, and nearly one third of the patients were asymptomatic. Computed tomography and ultrasonography were performed to show the nature and location of SPT. Most of the tumors were distributed in the pancreatic head (39.8%), tail (24.1%), body and tail (19.5%). Forty-five patients (9.2%) were diagnosed as malignant SPT with metastasis or invasion. None of the clinical factors was closely related to the malignant potential of SPT. Surgery was the main therapeutic modality for SPT. Local resection, distal pancreatectomy and pancreatoduodenectomy were the most common surgical procedures. Local recurrence and hepatic metastasis were found in 11 and 2 patients, respectively, after radical resection. Four patients died of tumor progression within 4 years after palliative resection of SPT. The prognosis of SPT patients was good with a 5-year survival rate of 96.9%. CONCLUSION: SPT of the pancreas is a rare indolent neoplasm that typically occurs in young females. It is a low-grade malignancy and can be cured with extended resection. The prognosis of such patients is good although the tumor may recur and metastasize.

[Prognostic factors and outcome in patients with intrahepatic recurrence after hepatectomy for hepatocellular carcinoma].

OBJECTIVE: To investigate the prognostic factors and treatment choice for intrahepatic recurrence after hepatectomy in patients with hepatocellular carcinoma (HCC). METHODS: Clinicopathological data of 184 HCC patients with intrahepatic recurrence after hepatectomy were collected. The influences of twenty one clinicopathological factors and treatment modalities on the survival after recurrence were retrospectively analyzed. RESULTS: Univariate analysis showed that preoperative serum alpha-fetoprotein (AFP) >100 ng/ml, microscopic venous invasion, patients classified as Child-Pugh class B or C at diagnosis of recurrence, multiple recurrence foci and early recurrence (< or =12 months) were poor prognostic factors. Cox multivariate analysis showed that Child-Pugh class at diagnosis of recurrence, number of recurrent foci and time to recurrence were independent risk factors for survival in patients with recurrence. Median survival after recurrence was 34 months, 23 months, 15 months and 9 months, respectively, in patients treated by repeated hepatectomy, local ablation therapy, transcatheter arterial chemoembolization (TACE) or non-treatment in 69 patients with solitary recurrence. There were statistically significant differences among these four groups (P < 0.05). CONCLUSION: classification of Child-Pugh class A at the first time of diagnosis, solitary recurrence, late recurrence (> 12 months), and intrahepatic recurrence occurred after repeated hepatectomy or local ablation therapy are better prognostic factors in patients with HCC recurrence.

ARHI, as a novel suppressor of cell growth and downregulated in human hepatocellular carcinoma, could contribute to hepatocarcinogenesis.

The identification of cancer genes differentially expressed in hepatocellular carcinoma (HCC) plays an important role in understanding the molecular mechanisms of hepatocarcinogenesis. Here, ARHI gene expression was analyzed by real-time RT-PCR and it was significantly downregulated in 33 of the 42 (78.6%, more than two folds) HCC specimens compared with adjacent noncancerous livers (P < 0.01). In addition, ARHI expression was reduced in some HCC samples at protein level confirmed by immunohistochemistry. Furthermore, our data suggested that the overexpression of ARHI can significantly inhibit cell growth and colony formation of Hep3B cells (P < 0.01), whilst silencing endogenous ARHI gene by RNAi could promote cell growth of Huh-7 and Focus. LOH of microsatellite markers D1S2806 and D1S2803 was only found in 2.4% (1 of 42 HCCs) of HCC cases. The expression of ARHI was obviously re-expressed in some HCC cells, Bel-7402, Bel-7405, QGY-7703 and Hep3B, by a demethylation agent, 5-aza-2'-deoxycytidine (DAC). DNA hypermethylation within ARHI promoter was identified in 47.1% of HCC specimens without ARHI expression. Our current observations provide evidences that ARHI downregulated in HCCs could play a role in liver cancer via acting as a tumor suppressor gene, which mainly was triggered by the epigenetic events in HCC specimens.

Down-regulation of SFRP1 as a putative tumor suppressor gene can contribute to human hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common cancers in the world. SFRP1 (the secreted frizzled-related protein 1), a putative tumor suppressor gene mapped onto chromosome 8p12-p11.1, the frequent loss of heterozygosity (LOH) region in human HCC, encodes a Wingless-type (Wnt) signaling antagonist and is frequently inactivated by promoter methylation in many human cancers. However, whether the down-regulation of SFRP1 can contribute to hepatocarcinogenesis still remains unclear. METHODS: We investigated the expression of SFRP1 through real time RT-PCR and immunohistochemistry staining. The cell growth and colony formation were observed as the overexpression and knockdown of SFRP1. The DNA methylation status within SFRP1 promoter was analyzed through methylation-specific PCR or bisulphate-treated DNA sequencing assays. Loss of heterozygosity was here detected with microsatellite markers. RESULTS: SFRP1 was significantly down-regulated in 76.1% (35/46) HCC specimens at mRNA level and in 30% (30/100) HCCs indicated by immunohistochemistry staining, as compared to adjacent non-cancerous livers. The overexpression of SFRP1 can significantly inhibit the cell growth and colony formation of YY-8103, SMMC7721, and Hep3B cells. The RNA interference against the constitutional SFRP1 in the offspring SMMC7721 cells, which were stably transfected by ectopic SFRP1, can markedly promote cell growth of these cells. LOH of both microsatellite markers D8S532 and D8SAC016868 flanking the gene locus was found in 13% (6 of 46 HCCs) and 6.5% (3 of 46 HCCs) of the informative cases, respectively, where 5 of 8 HCC specimens with LOH showed the down-regulation of SFRP1. DNA hypermethylation within SFRP1 promoter was identified in two of three HCC specimens without SFRP1 expression. Moreover, the DNA methylation of SFRP1 promoter was significantly reduced, along with the re-expression of the gene, in those HCC cell lines, Bel7404, QGY7701, and MHCC-H, as treated by DAC. CONCLUSION: Our data suggested that the down-regulation of SFRP1 as a candidate tumor suppressor gene, triggered by the epigenetic and/or genetic events, could contribute to the oncogenesis of HCC.

Discovering multiple transcripts of human hepatocytes using massively parallel signature sequencing (MPSS).

BACKGROUND: The liver is the largest human internal organ--it is composed of multiple cell types and plays a vital role in fulfilling the body's metabolic needs and maintaining homeostasis. Of these cell types the hepatocytes, which account for three-quarters of the liver's volume, perform its main functions. To discover the molecular basis of hepatocyte function, we employed Massively Parallel Signature Sequencing (MPSS) to determine the transcriptomic profile of adult human hepatocytes obtained by laser capture microdissection (LCM). RESULTS: 10,279 UniGene clusters, representing 7,475 known genes, were detected in human hepatocytes. In addition, 1,819 unique MPSS signatures matching the antisense strand of 1,605 non-redundant UniGene clusters (such as APOC1, APOC2, APOB and APOH) were highly expressed in hepatocytes. CONCLUSION: Apart from a large number of protein-coding genes, some of the antisense transcripts expressed in hepatocytes could play important roles in transcriptional interference via a cis-/trans-regulation mechanism. Our result provided a comprehensively transcriptomic atlas of human hepatocytes using MPSS technique, which could be served as an available resource for an in-depth understanding of human liver biology and diseases.

Up-regulation of DLK1 as an imprinted gene could contribute to human hepatocellular carcinoma.

Dysregulation of a genomic imprinting gene can contribute to carcinogenesis. Here, delta-like 1 homolog (Drosophila) (DLK1), a paternally expressed gene, was found to be significantly up-regulated in 60 (73.2%) of a total of 82 hepatocellular carcinoma (HCC) specimens using reverse transcription-polymerase chain reaction. In addition, immunohistochemistry staining was performed in another 88 HCC specimens, of which 50 (56.8%) cancerous tissues were considered as positive. The expression of DLK1 was obviously induced in HCC cells, Bel-7402 and MHCC-H, by a demethylation agent, 5-aza-2'-deoxycytidine. Furthermore, both demethylation of the DLK1 promoter (-565 to -362) and hypermethylation of the imprinting control domain in the region upstream of maternally expressed gene 3 were identified in a few HCC specimens. This implies that deregulation of genomic DNA methylation of the imprinted domain could be attributed to the up-regulation of DLK1 in HCC, although the undoubtedly complex mechanisms involved in the epigenetic event should be further investigated in HCC. Surprisingly, the expression of DLK1 in HCC was confirmed to be monoallelic specific, not biallelic, in three HCC specimens with a single nucleotide polymorphism as at T852C (rs2295660). Importantly, the exogenous DLK1 can significantly promote the cell proliferation of SMMC-7721 cells, a HCC cell line, whereas the suppression of endogenetic DLK1 through RNA interference can markedly inhibit cell growth, colony formation and tumorigenicity of HepG2, Hep3B and HuH-7 cells. These data suggest that DLK1 as an imprinted gene could be significantly up-regulated in HCC due to certain epigenetic events and contribute to the oncogenesis of this tumor.

[Comparison of endoscopic ultrasonography with computer-assisted tomography in the determination of preoperative stage and resectability of pancreatic and ampullary cancers].

OBJECTIVE: To study and compare the accuracy and sensitivity of endoscopic ultrasonography (EUS) and CT scaning in determination of preoperative stage and vascular invasion by pancreatic and ampullary cancers. METHODS: Fourty-two pancreatic cancer patients and 18 ampullary cancer patients were studied. With patients prepared according to conventional endoscopy, Olympus EUM-30 scope 1 set with a side view and 360 degrees rotate and switchable scanning probe [ultrasound frequency (7.5/12 MHz)], was introduced to the descending duodenum through the esophagus. Gas within the duodenum and stomach was aspirated. Then, in order to to facilitate ultrasound transmission, 200 ml deaerated water was injected into the duodenum and 500 ml into the stomach to distend it. The structures of each part of pancreatic head and ampullary together with surrounding vessels were scanned. Then, the scope was withdrawn to the gastric antrum, body and fundus gradually, while the pancreatic body and tail were scanned. RESULTS: Between Apr. 1996 to May 2004, a total of 42 pancreatic cancer patients and 18 ampullary cancer patients were examined by EUS. Meanwhile, all these 58 patients received preoperative CT scaning. The results of stage and vascular invasion determined by EUS in this series were as following; pancreatic cancer group (n = 42): accuracy in T2-4 stage was 100.0% (5/5), 75.0% (9/12) and 48.0% (12/25), respectively; ampullary cancer group (n = 18): T1-4 stage was 75.0% (3/4), 66.7% (2/3), 75.0% (6/8) and 33.3% (1/3), respectively; the accuracy in N stage: P-group: 80.0% in N1 (4/5), 90.0% in N0 (9/10); A-group: 50.0% in N1 (3/6), 91.0% in N0 (10/11). The sensitivity, specificity of vascular invasion, resectability and unresectablilty determined by EUS and CT as compared with surgical findings during operation was 52.9% (9/17), 93.1% (27/29), 77.1% (27/35) and 81.8% (9/11) for EUS (n = 60), respectively; and 11.8% (2/17), 92.6% (25/27), 62.5% (25/40) and 50.0% (2/4) for CT (n = 58), respectively. CONCLUSION: Endoscopic ultrosonography being one of the best image examinations to determine the stage and vascular invasion for pancreatic and ampullary cancer paitients is able to detect small pancreatic or ampullary cancer less than 2.0 cm in diameter due to its high resolution; but can not detect the secondary multiple distal metastases such as spread into the liver, peritonium or hepatoduodenal ligament, etc. due to its ultrasound depth limitation.

[Current diagnostic status, clinical and pathologic manifestation for a Crohn's disease].

OBJECTIVE: To evaluate the contemporary diagnostic and therapeutic status for Crohn's disease (CD), and analyze its clinical and pathologic manifestation. METHODS: Retrospectively we reviewed 220 hospitalized inflammatory bowel disease (IBD) cases in which 48 were diagnosed as CD. Data of diagnostic and therapeutic details were recorded. RESULTS: In the past 10 years 44 of the 48 CD cases were diagnosed in recent and 75.0% of the cases were in the onset age range from 17 to 40 years. The most common symptoms were abdominal pain, diarrhea and bloody stool. 16 (33.3%) of the cases were accompanied with extra-intestinal manifestations, 3 (6.3%) with perianal abscess, and 2 (4.2%) with intestinal fistulation. The main findings through colonoscopy were ulceration, obstruction and cobble stone sign, with a diagnostic correspondence of 85.7% (36/42). Non-caseous granulomas were totally identified in 43.2% (19/44) of the histology. Thirty cases were administrated with Sulfasalazine/Mesalazine (SASP/5-ASA) or corticosteroids/immuno-suppressor in which 27 got clinically improved. Thirteen patients underwent surgery. CONCLUSION: The diagnostic incidence of Crohn's disease has been increased in recent years. The combination of endoscopy, radiography and histology is the best way for the diagnosis of CD. Small intestinal endoscopy and capsule endoscopy with repeated histopathology and follow-up are helpful for the diagnosis.