Aberrant FoxM1B expression increases matrix metalloproteinase-2 transcription and enhances the invasion of glioma cells

We recently showed that FoxM1 is overexpressed in human glioblastomas and that forced FoxM1B expression in anaplastic astrocytoma cells leads to the formation of highly invasive glioblastoma multiforme (GBM) in nude mice. However, the molecular mechanisms by which FoxM1 enhances glioma invasion are unknown. In this study, we found that FoxM1 overexpression increased matrix metalloproteinase (MMP)-2 expression in glioma cells, whereas blockade of FoxM1 expression suppressed MMP-2 expression. Transfection of FoxM1 into glioma cells directly activated the MMP-2 promoter, whereas inhibition of FoxM1 expression by FoxM1-siRNA suppressed its activation. We identified a FoxM1-binding site in the MMP-2 promoter and demonstrated that FoxM1 protein bound directly to it. Mutation of this FoxM1-binding site significantly attenuated MMP-2 promoter activity. Furthermore, FoxM1 overexpression increased the invasiveness of glioma cells, whereas inhibition of FoxM1 expression suppressed the invasiveness of GBM cells. Inhibition of MMP-2 by a specific MMP-2 inhibitor reversed the invasive phenotype of glioma cells overexpressing FoxM1. Finally, immunohistochemical analysis of 45 human GBM specimens showed a significant correlation between FoxM1 overexpression and elevated MMP-2 expression. Collectively, these findings provide evidence that FoxM1 contributes to glioma progression by enhancing MMP-2 gene transcription and thus tumor-cell invasion.

The 44 kDa Pim-1 kinase directly interacts with tyrosine kinase Etk/BMX and protects human prostate cancer cells from apoptosis induced by chemotherapeutic drugs

Protein kinase Pim-1 has been implicated in the development of hematopoietic and prostatic malignancies. Here, we present the evidence that two isoforms, the 44 and 33 kDa Pim-1, are expressed in all human prostate cancer cell lines examined. The subcellular localization of human 44 kDa Pim-1 is primarily on the plasma membrane, while the 33 kDa isoform is present in both the cytosol and nucleus in PCA cells. The 44 kDa Pim-1 contains the proline-rich motif at the N-terminus and directly binds to the SH3 domain of tyrosine kinase Etk. Such interaction leads to the activation of Etk kinase activity possibly by competing with the tumor suppressor p53. This is corroborated by the fact that overexpression of the 44 kDa Pim-1 in prostate cancer cells confers the resistance to chemotherapeutic drugs. Our results suggest that these two isoforms of Pim-1 kinase may regulate distinct substrates and the 44 kDa Pim-1 may play a more prominent role in drug resistance in prostate cancer cells.

Novel gastrin receptors mediate mitogenic effects of gastrin and processing intermediates of gastrin on Swiss 3T3 fibroblasts. Absence of detectable cholecystokinin (CCK)-A and CCK-B receptors

We have reported previously mitogenic effects of gastrin on several immortalized and neoplastic cell lines, including Swiss 3T3 fibroblasts. Receptor subtypes, cholecystokinin (CCK)-A and CCK-B, for a closely related peptide, cholecystokinin, were recently cloned. These studies were undertaken to investigate if CCK-A- and CCK-B receptors were perhaps mediating the mitogenic effects of gastrin on Swiss 3T3 cells. Receptor antagonists that inhibit the biological effects and binding of peptides to the CCK-A (L-364,718 (L18)) and CCK-B (L-365,260 (L60)) receptors were ineffective toward inhibiting the binding and proliferative effects of gastrin on Swiss 3T3 cells. Radiolabeled L18 and L60 demonstrated no binding to the cells, indicating that CCK-A and CCK-B receptors may be absent on Swiss 3T3 cells. Radiolabeled CCK-8, gastrin, L18, and L60, on the other hand, demonstrated specific binding to a pancreatic cancer cell line (AR42J cells) (used as a positive control). In cross-linking studies the molecular mass of the major band of gastrin receptors (GR) on Swiss 3T3 cells was determined to be approximately 45 kDa. The mitogenic potency of 0.1-1.0 nM gastrin-like peptides on Swiss 3T3 cells was in the order of G1-17 > or = G1-17-Gly > G5-17 > or = G5-17-Gly > G2-17 > CCK-8-Gly > or = G1-17-Lys > or = CCK-8. The relative binding affinity of the peptides (based on the dose-dependent inhibition of binding of 125I-G1-17 to Swiss 3T3 cells) was similar to the relative mitogenic potency of the peptides as given above. Furthermore, G1-17-Gly was equally effective as G1-17 in displacing the binding of 125I-G1-17 to the 45-kDa GR from the Swiss 3T3 cells. Based on these studies it became evident that the novel gastrin preferring GR, expressed by Swiss 3T3 cells, binds and mediates the mitogenic effects of not only the mature (amidated) forms of gastrin-like peptides but also binds and mediates the mitogenic effects of glycine-extended forms of gastrin-like peptides. Possible mRNA expression of CCK-A and CCK-B receptor subtypes by gastrin-responsive rodent intestinal and fibroblast cell lines (Swiss 3T3, IEC-6, CA) was measured by the methods of Northern blot analysis and reverse transcriptase-polymerase chain reaction. mRNA from rat pancreas, AR42J cells, and rat antrum served as positive controls.(ABSTRACT TRUNCATED AT 400 WORDS)

Autocrine gastrins in colon cancer cells Up-regulate cytochrome c oxidase Vb and down-regulate efflux of cytochrome c and activation of caspase-3

Suppression of the gastrin gene in human colon cancer cells by stably expressing antisense (AS) gastrin RNA results in significant growth suppression of AS cells. To understand mechanisms mediating the growth effects of autocrine gastrins, differential expression of transcripts by AS and control (C) clones of a representative cell line (HCT-116) was analyzed to identify target genes of autocrine gastrins. Six differentially expressed transcripts were confirmed and sequenced. Of these, the RNA and protein levels of cytochrome c oxidase (COX) Vb were significantly higher in C versus AS cells. The expression of COX Vb by colon cancer cells was proportional to the expression of gastrin. Higher levels of COX Vb coprecipitated with cytochrome c in the mitochondria of C versus AS cells. Treatment of mitochondria with digitonin resulted in a 2-fold higher release of cytochrome c from AS versus C mitochondria. As a corollary, the cytosolic levels of cytochrome c were significantly higher in AS versus C cells, which correlated with approximately 2- and approximately 3-fold higher activation of caspase-9 and -3, respectively, in AS versus C cells in response to camptothecin. Thus, autocrine gastrins may support growth/survival of cells by up-regulating COX Vb, which may decrease the sensitivity of the cancer cells to apoptotic stimuli by increasing retention of cytochrome c in mitochondria.

Proliferation and differentiation of a human colon cancer cell line (CaCo2) is associated with significant changes in the expression and secretion of insulin-like growth factor (IGF) IGF-II and IGF binding protein-4: role of IGF-II

The extent to which the insulin-like growth factor (IGF) system contributes to the initiation and progression of colon cancer remains poorly defined. We recently reported that a majority of human colon cancers express and secrete the potent mitogen IGF-II and at least two inhibitory binding proteins, IGFBP-2 and IGFBP-4. In the present study we measured the expression and secretion of IGF-II, IGFBP-2, and IGFBP-4 in relation to growth and differentiation of CaCo2 human colon cancer cells, which undergo spontaneous enterocytic differentiation in culture. Under the conditions of the present study, CaCo2 cells demonstrated an initial rapid phase of growth between Day 2 through days 7-9 of culture, followed by a significant retardation in the growth between days 9-13. Alkaline phosphatase (ALP) activity, a marker of enterocytic differentiation, progressively increased between Days 7-13 in culture, temporally correlating with post-confluent phase of negligible growth. These changes in growth and differentiation were accompanied by > 80% decline in the relative concentration of IGF-II messenger RNA (mRNA) between Days 2-13. In contrast, the relative mRNA concentrations of inhibitory binding proteins (IGFBP-2 and IGFBP-4) increased rapidly to 200% of Day 2 values by Days 5-7 before returning to baseline levels by Day 13. The relative protein concentrations of the three factors measured in the conditioned media of the cells followed a pattern very similar to that measured for the mRNA levels. While the changes in the relative protein concentrations and mRNA levels of IGF-II and IGFBP-4 were statistically significant, the changes measured in the RNA and protein levels of IGFBP-2 were not, as a result of large inter experimental variations. Thus these results suggested that CaCo2 cell differentiation may require an attenuation of IGF-II effects. To confirm the latter possibility, additional studies were conducted with a specific neutralizing antibody against IGF-II. Incubation of CaCo2 cells with anti-IGF-II antibodies from Day 0 through Day 7 significantly retarded the growth of the cells and was accompanied by a significant increase in the concentration of Alkaline phosphatase activity per 10(6) cells. Recently, we reported a potent inhibitory role of IGFBP-4 in the growth of colon cancer cells. In the present studies, a possible important role of IGF-II is illustrated not only in the growth but also in the differentiation of colonic cells. Our studies thus suggest that differential expression of IGF-II and IGFBPs may be playing a critical role in both proliferation and differentiation of colonocytes.

Extracellular lumican augments cytotoxicity of chemotherapy in pancreatic ductal adenocarcinoma cells via autophagy inhibition

Lumican, an extracellular matrix proteoglycan overexpressed by pancreatic stellate cells (PSCs) and pancreatic ductal adenocarcinoma cells (PDACs), drives the formation of a tumor-specific microenvironment. We recently showed that extracellular lumican inhibits pancreatic cancer cell growth and is associated with prolonged survival after surgery. Here we investigated the role of extracellular lumican in chemotherapy-mediated cancer therapy. Lumican secretion was increased by chemotherapeutic agents in PDAC, and especially in PSCs, and appeared to be linked to the extent of cells' response to chemotherapy-induced growth inhibition. In multiple PDAC models, including cell lines, patient-derived xenografts and lumican knockout mice, lumican significantly increased antitumor effect of chemotherapy. This effect was associated with DNA damage, apoptosis and inhibition of cell viability, glucose consumption, lactate production and vascular endothelial growth factor secretion. In PDAC cells, chemotherapeutic agents triggered autophagosome formation and increased LC3 expression through the reactive oxygen species-mediated AMP-activated kinase (AMPK) signaling pathway. Inhibition of gemcitabine-induced autophagy in cancer cells by treatment with AMPK inhibitor compound C, lysosomal inhibitor chloroquine or autophagy inhibitor 3MA enhanced gemcitabine-induced apoptosis, suggesting that autophagy is a protective cellular response to gemcitabine treatment. Importantly, lumican dramatically decreased AMPK activity, inhibiting chemotherapy-induced autophagy in both in vitro and in vivo PDAC models. Co-treatment of PDAC cells with lumican and gemcitabine increased mitochondrial damage, reactive oxygen species (ROS) production and cytochrome c release, indicating that lumican-induced disruption of mitochondrial function may be the mechanism of sensitization to gemcitabine. Together, our findings demonstrate that extracellular lumican augments cytotoxicity of chemotherapy in PDAC cells through inhibition of chemotherapeutic agent-induced autophagy.

Overexpression of the DMP1 C-terminal fragment stimulates FGF23 and exacerbates the hypophosphatemic rickets phenotype in Hyp mice

Dentin matrix protein-1 (DMP1) or phosphate-regulating gene with homologies to endopeptidases on the X chromosome (PHEX) inactivation results in elevation of the phosphaturic hormone fibroblast growth factor (FGF)-23, leading to hypophosphatemia, aberrant vitamin D metabolism, and rickets/osteomalacia. Compound mutant Phex-deficient Hyp and Dmp1(ko) mice exhibit nonadditive phenotypes, suggesting that DMP1 and PHEX may have interdependent effects to regulate FGF23 and bone mineralization. To determine the relative importance of DMP1 and PHEX in regulating FGF23 and mineralization, we tested whether the transgenic expression of full-length [Dmp1(Tg(full-length))] or C-terminal Dmp1 [Dmp1(Tg(57kDa))] could rescue the phenotype of Hyp mice. We found that Dmp1(ko) and Hyp mice have similar phenotypes characterized by decreased cortical bone mineral density (-35% vs. wild type, P < 0.05) and increased serum FGF23 levels (~12-fold vs. wild type, P < 0.05). This was significantly corrected by the overexpression of either the full-length or the C-terminal transgene in Dmp1(ko) mice. However, neither of the transgenes rescued the Hyp mice phenotype. Hyp/Dmp1(Tg(full-length)) and Hyp mice were similar, but Hyp/Dmp1(Tg(57 kDa)) mice exhibited worsening of osteomalacia (-20% cortical bone mineral density) in association with increased serum FGF23 levels (+2-fold) compared with Hyp mice. Bone FGF23 mRNA expression was decreased and a 2-fold increase in the ratio of the full-length/degraded circulating FGF23 was observed, indicating that degradation of FGF23 was impaired in Hyp/Dmp1(Tg(57 kDa)) mice. The paradoxical effects of the C-terminal Dmp1 transgene were observed in Hyp/Dmp1(Tg(57 kDa)) but not in Dmp1(Tg(57 kDa)) mice expressing a functional PHEX. These findings indicate a functional interaction between PHEX and DMP1 to regulate bone mineralization and circulating FGF23 levels and for the first time demonstrate effects of the C-terminal DMP1 to regulate FGF23 degradation.

Prolonged exposure to extracellular lumican restrains pancreatic adenocarcinoma growth

We previously demonstrated that pancreatic stellate cells within pancreatic ductal adenocarcinoma (PDAC) stroma secrete lumican and its presence is associated with prolonged survival of patients with localized PDAC. Here, we observed that extracellular lumican decreases PDAC tumour cell growth in xenograft and syngeneic orthotopic animal models, and induces growth inhibition of low-passage human PDAC cells in a species-specific manner. PDAC cells grown in variant culture conditions and exposed to extracellular lumican display typical characterizations of cancer cell in a quiescent state, such as growth inhibition, apoptosis, G0/G1 arrest and chemoresistance. Importantly, extracellular lumican is associated with diminished ERK1/2 phosphorylation and increased p38 phosphorylation within PDAC cells. We further demonstrated that extracellular lumican physically binds with EGFR to trigger EGFR internalization and downregulation of EGFR and its downstream signal molecule ERK. Lumican enhances casitas B-lineage lymphoma expression, which stabilized the TGFβ Type II receptor sensitizing PDAC cells to TGFβ-mediated activation of p38 and SMAD signals. These provide a mechanism for the shift in signalling and phenotypic changes we observed after prolonged exposure to lumican. Together, our findings demonstrate that stromal lumican restrains PDAC cell growth through mediating cell entry into a quiescent state.

Hepatitis C virus upregulates B-cell receptor signaling: a novel mechanism for HCV-associated B-cell lymphoproliferative disorders

B-cell receptor (BCR) signaling is essential for the development of B cells and has a critical role in B-cell neoplasia. Increasing evidence indicates an association between chronic hepatitis C virus (HCV) infection and B-cell lymphoma, however, the mechanisms by which HCV causes B-cell lymphoproliferative disorder are still unclear. Herein, we demonstrate the expression of HCV viral proteins in B cells of HCV-infected patients and show that HCV upregulates BCR signaling in human primary B cells. HCV nonstructural protein NS3/4A interacts with CHK2 and downregulates its activity, modulating HuR posttranscriptional regulation of a network of target mRNAs associated with B-cell lymphoproliferative disorders. Interestingly, the BCR signaling pathway was found to have the largest number of transcripts with increased association with HuR and was upregulated by NS3/4A. Our study reveals a previously unidentified role of NS3/4A in regulation of host BCR signaling during HCV infection, contributing to a better understanding of the molecular mechanisms underlying HCV-associated B-cell lymphoproliferative disorders.

Bacillus licheniformis, a potential probiotic, inhibits obesity by modulating colonic microflora in C57BL/6J mice model

AIMS

This study evaluated the effects of a potential probiotic, Bacillus sp., on the growth, serum and hepatic triglyceride, histological features of liver tissues and colonic microflora in high-fat diet-induced obese mice.

METHODS AND RESULTS

Sixty male C57BL/6J mice were randomly divided into five groups: mice fed a low-fat diet (Cont), mice fed a high-fat diet (Hf), Hf and orally challenged with Bacillus subtilis (Bs), B. licheniformis (Bl) and a mixture of B. subtilis and B. licheniformis (Bls). Gavage feeding was provided at week 9 and the experiment was continued for 8 weeks. Treatment with B. licheniformis and a mixture of Bacillus sp. attenuated body weight gain at the end of study and enhanced glucose tolerance by sensitizing insulin action in the Hf-fed mice. Lower serum and hepatic triglyceride and epididymal fat weight were observed in Bl and Bls groups than that of Hf group. Lesser hepatic fat deposition was observed in the Bl and Bls groups than in the Hf group. High-throughput sequencing showed that Bacillus sp. supplementation dramatically changed the colonic bacterial community in obese mice.

CONCLUSIONS

Bacillus licheniformis reduced body weight and improved glucose tolerance, obesity and insulin resistance in Hf-fed mice by changing colonic microbiota composition.

SIGNIFICANCE AND IMPACT OF THE STUDY

Orally administration of Bacillus licheniformis may reduce body weight and decrease fat deposition by modulating colonic bacterial community in Hf model.

Rheumatoid arthritis fibroblast-like synoviocytes co-cultured with PBMC increased peripheral CD4+ CXCR5+ ICOS+ T cell numbers

'Circulating' T follicular helper cells (Tfh), characterized by their surface phenotypes CD4⁺ chemokine receptor 5 (CXCR5)⁺ inducible co-stimulatory molecule (ICOS)⁺ , have been identified as the CD4⁺ T cell subset specialized in supporting the activation, expansion and differentiation of B cells. Fibroblast-like synoviocytes (FLS) are critical in promoting inflammation and cartilage destruction in rheumatoid arthritis (RA), and the interaction between FLS and T cells is considered to facilitate FLS activation and T cell recruitment. However, it remains unknown whether RA-FLS co-cultured with activated peripheral blood mononuclear cells (PBMC) has immunoregulatory effects on peripheral Tfh. In the present study, we co-cultured RA-FLS with or without anti-CD3/CD28-stimulated PBMC. The results showed that RA-FLS co-cultured with stimulated PBMC could increase the numbers of CD4⁺ CXCR5⁺ ICOS⁺ T cells of RA PBMC possibly via the production of interleukin (IL)-6, a critical cytokine involved in the differentiation of Tfh cells. We also observed increased reactive oxygen species (ROS) levels in the co-culture system of RA-FLS and PBMC. The percentage of CD4⁺ CXCR5⁺ ICOS⁺ T cells was decreased when ROS production was inhibited by N-acetyl-L-cysteine (NAC), a specific inhibitor which can decrease ROS production. In addition, we showed that the higher levels of tumour necrosis factor (TNF)-α and IL-1β in the co-culture system and the blocking of TNF receptor 2 (TNF-R2) and IL-1β receptor (IL-1βR) both decreased the numbers of CD4⁺ CXCR5⁺ ICOS⁺ T cells. Our study reveals a novel mechanistic insight into how the interaction of RA-FLS and PBMC participates in the RA pathogenesis, and also provides support for the biologicals application for RA.

Role of autocrine and endocrine gastrin-like peptides in colonic carcinogenesis

Colon carcinogenesis is a multistep process that involves deletions, mutations, and changes in expression of genes that regulate growth, differentiation, and apoptosis. Hyperproliferation can initiate dysplastic growth, resulting in accumulation of genetic defects and progression of colon cancer. Although genetic instability, because of inheritance of specific genetic defects, plays a dominant role in familial cancers, in the majority of sporadic cancers hyperproliferation is likely to play a permissive role in initiation and progression of the disease. Thus factors that regulate growth, differentiation, and apoptosis are likely to play an important role in colon carcinogenesis. Autocrine gastrins, insulin-like growth factor-II, transforming growth factor-alpha, and endocrine gastrins have been implicated in the tumorigenic potential of colon cancer cells. In this article we focus on the role of endocrine and autocrine gastrins in colon cancer and review recent advances that suggest a role of processing intermediates of gastrin in colon carcinogenesis.

First trial of home ECG and blood pressure telemonitoring system in Macau

OBJECTIVE

To determine the feasibility of home monitoring of patients with cardiac disease or hypertension.

METHODS

An improved home electrocardiographic and blood pressure telemonitoring system linked to a central workstation was tested in 10 patients in Macau for 3 months.

RESULTS

The total number of connections was 1377. Of the automatic alarm connections, 32.5% were false positive, with the percentage of false positives ranging from 7.6 to 54.6 for different patients. Both patients and physicians found the system easy to use.

CONCLUSIONS

Further investigation is required to match the number of patients with the system capacity. A more robust dysrhythmia detection algorithm is needed to reduce the number of false alarms. Nevertheless, the results were sufficiently good that the trial is being expanded.

Differential activation of IGF-II promoters P3 and P4 in Caco-2 cells during growth and differentiation

BACKGROUND & AIMS

Insulin-like growth factor (IGF)-II gene is overexpressed in colon cancers. Transcriptional up-regulation may be the major mechanism contributing to its overexpression. IGF-II messenger RNA (mRNA) levels are up-regulated during proliferation followed by a significant decline during differentiation of Caco-2 cells. Mechanisms underlying transcriptional regulation of the IGF-II gene promoters (P1-P4) have yet to be examined in colon cancers, which was the basis for this study.

METHODS

Ribonuclease protection assay was used to measure IGF-II mRNA derived from P1-P4. To determine if changes in the IGF-II transcripts reflected differences in promoter activity, transient transfection assays with the full-length P1-P4-luciferase expression vectors were performed.

RESULTS

Both P3- and P4-derived transcripts were significantly up-regulated during the proliferative phase of the cells (days 3-6 in culture) and declined rapidly in cells undergoing differentiation (days 7-10); conversely, P1- and P2-derived transcripts were not detected. Similarly, transcriptional activity of P3 and P4 promoters reached peak levels by days 4-6 and declined rapidly thereafter. P1 and P2 were relatively inactive on all days.

CONCLUSIONS

The activity of the P3 and P4 promoters may play a selective role in regulating IGF-II mRNA levels during growth and differentiation of colon cancer cells.

Cloning of the functional promoter for human insulin-like growth factor binding protein-4 gene: endogenous regulation

The majority of the colon cancers analyzed to-date express insulin-like growth factor binding protein (IGFBP)-4, and antisense inhibition of IGFBP-4 messenger RNA (mRNA) confers a growth advantage to the cells in response to endogenous and exogenous IGFs. We recently reported a significant up-regulation of IGFBP-4 expression in a human colon cancer cell line (CaCo2) on spontaneous differentiation of the cells in culture. This suggests that the expression of IGFBP-4 may be related to growth and differentiation of colon cancer cells. To study the endogenous factors involved in the transcriptional regulation of IGFBP-4, we have isolated and sequenced the human (h) IGFBP-4 promoter. The approximately 1.3 kilobase pair (kb) 5' flanking region of the IGFBP-4 gene is GC rich and possesses several potential regulatory elements. These elements include a typical TATA box with sequence TATAA, located -299 nt from the initiation ATG codon. The cap site is located 14 nt downstream of the TATA box as determined by primer extension analysis. A 1.4-kb DNA fragment including the 1.254 kb 5' flanking region of the hIGFBP-4 gene was subcloned into a luciferase reporter vector (pGL-2 basic) either in the sense (BP-4-S-pGL) (S) or antisense (BP-4-AS-pGL) (AS) (negative control) orientation, relative to the luciferase coding sequence in the vector. CaCo2 cells were transfected with either the S or the AS vectors on days 2-10 of culture; cotransfection with the SV40-beta-Galactidose (Gal) vector was used to correct for transfection efficiency. The ratio of luciferase/beta-Gal expression by CaCo2 cells transfected with the S vectors increased significantly from days 3 and 4 to days 5 and 6 of culture, followed by a sharp decline on days 7-9, resembling the pattern of endogenous expression of IGFBP-4 by the cells; the expression of luciferase by the AS vectors remained low and insignificant. These results thus suggest that the approximately 1.4 kb 5' flanking region of the IGFBP-4 gene contains the cis elements required for regulation of the IGFBP-4 gene. Cloning and sequencing of the functional hIGFBP-4 promoter will enable us, for the first time, to study the endogenous factors/mechanisms responsible for the growth/differentiation (cell density) associated regulation of IGFBP-4 expression in colonic epithelial cells.

Design and development of an interactive medical teleconsultation system over the World Wide Web

The objective of the medical teleconsultation system presented in this paper is to demonstrate the use of the World Wide Web (WWW) for telemedicine and interactive medical information exchange. The system, which is developed based on Java, could provide several basic Java tools to fulfill the requirements of medical applications, including a file manager, data tool, bulletin board, and digital audio tool. The digital audio tool uses point-to-point structure to enable two physicians to communicate directly through voice. The others use multipoint structure. The file manager manages the medical images stored in the WWW information server, which come from a hospital database. The data tool supports cooperative operations on the medical data between the participating physicians. The bulletin board enables the users to discuss special cases by writing text on the board, send their personal or group diagnostic reports on the cases, and reorganize the reports and store them in its report file for later use. The system provides a hardware-independent platform for physicians to interact with one another as well as to access medical information over the WWW.

microRNA-1205 promotes cell growth by targeting APC2 in lung adenocarcinoma

OBJECTIVE

An increasing amount of evidence indicates that microRNAs (miRNAs) can be potential diagnostic and prognostic markers for various cancers. In this study, a novel miRNA, miR-1205, was identified in lung adenocarcinoma (LUAD).

PATIENTS AND METHODS

First, the expression of miR-1205 in tissues was determined and verified to be correlated with the prognosis of patients. Overexpression and knockdown in LUAD cells were chosen to evaluate the effect of miR-1205 on cell growth in vitro. Luciferase assays, Western blot and rescue assays were performed to screen and confirm potential targets of miR-1205.

RESULTS

We demonstrated that miR-1205 was down-regulated in the tissues of LUAD, and that miR-1205 may be a predictor of overall survival of LUAD. The overexpression of miR-1205 promoted cell proliferation and colony formation. Our results indicated that miR-1205 targeted APC2 directly, serving as a vital part in accelerating LUAD cell proliferation.

CONCLUSIONS

We showed that miR-1205 could promote LUAD cell growth by targeting APC2 protein expression and provided further proof of miR-1205 as a potential non-invasive biomarker and therapeutic target for LUAD.

Identification of key genes involved in nasopharyngeal carcinoma

Introduction

Nasopharyngeal carcinoma is the most common cancer originating from the nasopharynx.

Objective

To study the mechanisms of nasopharyngeal carcinoma, we analyzed GSE12452 microarray data.

Methods

GSE12452 was downloaded from the Gene Expression Omnibus database and included 31 nasopharyngeal carcinoma samples and 10 normal nasopharyngeal tissue samples. The differentially expressed genes were screened by ANOVA in the PGS package. Using the BiNGO plugin in Cytoscape and pathway enrichment analysis in the PGS package, functional and pathway enrichment analyses were performed separately to predict potential functions of the differentially expressed genes. Furthermore, Transcription factor-differentially expressed gene pairs were searched, and then the transcription factor-differentially expressed gene regulatory network was visualized using Cytoscape software.

Results

A total of 487 genes were screened as differentially expressed genes between the nasopharyngeal carcinoma samples and the normal nasopharyngeal tissue samples. Enrichment analysis indicated that PTGS2 was involved in the regulation of biological process and small cell lung cancer. ZIC2 and OVOL1 may function in nasopharyngeal carcinoma through targeting significantly up-regulated genes (such as PTGS2, FN1, CXCL9 and CXCL10) in the Transcription factor-differentially expressed gene regulatory network (e.g., ZIC2→PTGS2 and OVOL1→CXCL10).

Conclusion

PTGS2, FN1, CXCL9, CXCL10, ZIC2 and OVOL1 might play roles in nasopharyngeal carcinoma.

Incomplete processing of progastrin expressed by human colon cancer cells: role of noncarboxyamidated gastrins

Gastrin is mitogenic for several colon cancers. To assess a possible autocrine role of gastrin in colon cancers, we examined human colon cancer cell lines for expression of gastrin mRNA and various forms of gastrin. Gastrin mRNA was not detected in the majority of colon cancer cell lines by Northern hybridization but was detected in all human colon cancer lines by the sensitive method of reverse transcriptase-polymerase chain reaction (PCR). Gastrin mRNA was quantitated by the competitive PCR method. The majority of cell lines expressed very low levels of gastrin mRNA (< 1-5 copies/cell); only one cell line expressed > 20 copies/cell. The mature carboxyamidated form of gastrin was not detected in any of the cell lines by radioimmunoassay or immunocytochemistry. Results suggested that either gastrin mRNA expressed by colon cancer cells was altered (mutated) or posttranslational processing of progastrin was incomplete. Gastrin cDNA from all the colon cancer cell lines had an identical sequence to the published sequence of human gastrin cDNA. Specific antibodies against precursor forms of gastrin were used, and significant concentrations of nonamidated (glycine-extended) and prepro forms of gastrin were measured in tumor extracts of representative colon cancer cell lines. The presence of precursor forms of gastrin suggested a lack of one or more of the processing enzymes and/or cofactors. Significant concentrations of the processing enzyme (peptidylglycine alpha-amidating monooxygenase) were detected in colon cancer cells by immunocytochemistry. Therefore, lack of other cofactors or enzymes may be contributing to incomplete processing of precursor forms of gastrin, which merits further investigation. Since low levels of gastrin mRNA were expressed by the majority of human colon cancer cell lines and progastrin was incompletely processed, it seems unlikely that gastrin can function as a viable autocrine growth factor for colon cancer cells. High concentrations of glycine-extended gastrin-17 (GG) (> 10(-6) M) were mitogenic for a gastrin-responsive human colon cancer (DLD-1) cell line in vitro. It remains to be seen if GG or other precursor forms of gastrin are similarly mitogenic in vivo, which may then lend credibility to a possible autocrine role of gastrinlike peptides in colon cancers.

HLA-A, HLA-B, HLA-DRB1 allele and haplotype frequencies in 6384 umbilical cord blood units and transplantation matching and engraftment statistics in the Zhejiang cord blood bank of China

Umbilical cord blood (UCB) is a widely accepted source of progenitor cells, and now, many cord blood banks were established. Here, we analysed the HLA-A, HLA-B and HLA-DRB1 allele and haplotype frequencies, HLA matching possibilities for searching potential donors and outcome of UCB transplantations in Zhejiang cord blood bank of China. A total of 6384 UCB units were characterized for 17 HLA-A, 30 HLA-B and 13 HLA-DRB1 alleles at the first field resolution level. Additionally, B*14, B*15 and B*40 were typed to the second field level. A total of 1372 distinct A-B-DRB1 haplotypes were identified. The frequencies of 7 haplotypes were more than 1%, and 439 haplotypes were <0.01%. A*02-B*46-DRB1*09, A*33-B*58-DRB1*03 and A*30-B*13-DRB1*07 were the most common haplotypes, with frequencies of 4.4%, 3.3%, and 2.9%, respectively. Linkage disequilibrium(LD) analysis showed that there were 83 A-B, 106 B-DRB1, 54 A-DRB1 haplotypes with positive LD, in which 51 A-B, 60 B-DRB1, 32 A-DRB1 haplotypes exhibited a significant LD (P < 0.05). In 682 search requests, 12.9%, 40.0% and 42.7% of patients were found to have 6 of 6, 5 of 6 and 4 of 6 HLA-A, HLA-B and HLA-DRB1 matching donors, respectively. A total of 30 UCB units were transplanted to 24 patients (3 patients not evaluated due to early death); 14 of 21 patients (66.7%) engrafted. This study reveals the HLA distribution and its transplantation application in the cord blood bank of Zhejiang province. These data can help to select potential UCB donors for transplantation and used to assess the scale of new cord blood banking endeavours.

Surgical timing for facial paralysis after temporal bone trauma

OBJECTIVES

To explore surgical timing of facial paralysis after temporal bone trauma.

METHODS

The clinical data of the patients with facial paralysis after temporal bone trauma who underwent subtotal facial nerve decompression were retrospectively collected, and 80 cases followed-up for one year were enrolled in the study. They were divided into different subgroups according to the age, onset, and interval between facial paralysis and surgery, and the outcomes of facial nerve between different subgroups were compared.

RESULTS

The number of patients who achieved good recovery of HB Grade I or II was 52 of 80 (65.0%). 43 of 66 cases (65.2%) in the younger group had good recovery of facial nerve in contrast to 9 of 14 cases (64.3%) in the elderly group, without significant difference (p>0.05). 9 of 13 cases (69.2%) in the delayed onset group had good recovery, while 43 of 67 cases (64.2%) in the immediate onset group had good recovery, without significant difference (p>0.05). The good recovery rate of the <1month group was statistically higher compared to the 3-6months group or the >6months group (P<0.05), while the good recovery rate of the <1month group was not statistically higher than that of the 1-2months group or the 2-3months group (P>0.05).

CONCLUSION

This study demonstrated that the good recovery rate of facial paralysis after temporal bone trauma was uncorrelated with age and onset. It was better to perform surgical decompression within 3months after facial paralysis.

Gastrin gene expression in human colon cancer cells measured by a simple competitive PCR method

Gastrin is mitogenic for several colon cancers and is postulated as an autocrine growth factor for colon cancer cells. In the present study we report the development of a simple competitive polymerase chain reaction (PCR) method for measuring relative abundance of gastrin gene expression in colon cancer cells. Primers flanking exons 2 and 3 of the gastrin gene were utilized for co-amplification of cDNA and genomic DNA. The amplification of genomic DNA was distinguished from that of cDNA by the presence of the 130 bp intron sequence which was resolved by electrophoresis on agarose gels. A standard reaction of competitive PCR, using known concentrations of genomic DNA and cDNA, was first established. The steady state levels of gastrin mRNA were next quantitated in three human colon cancer cell lines (HCT-116, Colo-205 and DLD-1) by competitive PCR. Gastrin mRNA levels in these cell lines ranged from approximately 0.1 to 1.0 fmoles/mg total RNA (approximately 2-25 copies of gastrin mRNA per cell). Thus low to moderate levels of gastrin were expressed by human colon cancer cell lines which may function as autocrine growth factors for colon cancers.