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Biomedical subjects

Wei Hu

Publications and source records attributed to Wei Hu.

At least 91 records · Page 5Linked to original sources
PubMed2004

[Study on the relationship between hepatitis C virus infection and sharing injection equipment, sexual behavior among injecting drug users].

OBJECTIVE: To study hepatitis C virus (HCV) transmission through different modes of sharing injection equipment and sexual behavior among injecting drug users (IDUs) in Liangshan of Sichuan province. METHODS: A community-based survey was conducted to investigate past and current demographic data, injection equipment sharing patterns and sexual behavior of IDUs. Blood samples were also taken to test for HCV. The survey was conducted between Nov 8 and Nov 29, 2002. 379 subjects were screened through outreach recruitment and peer informing. SPSS (11.5) was used for data analysis. RESULTS: HCV prevalence was 71.0% (269/379). Needles or syringes sharing in the past three months and past syphilis infection were strongly associated with HCV transmission after univariate analysis using chi-square test. Trend analysis indicated that HCV infection rate increased along with the increase of needles or syringes sharing, sharing of rinse water and the number of peers sharing the equipments. Data from multivariate logistic regression showed that sharing of needles or syringes and history of syphilis infection were significantly associated with HCV transmission. No significant difference was found between HCV infection and sexual behavior after univariate analysis using chi-square test. CONCLUSION: Further sero-epidemiological prospective cohort studies should be conducted to clarify the relationship between different modes of sharing injection equipment, sexual behavior and HCV infection.

Adult↗
PubMed2004

Peroxisome proliferator-activated receptor gamma and retinoid X receptor ligands are potent inducers of differentiation and apoptosis in leukemias.

The peroxisome proliferator-activated receptor gamma (PPAR gamma) is a member of the nuclear receptor family that forms heterodimers with retinoid X receptor. These heterodimers bind to DNA and activate the transcription of target genes. Here, we report that the PPAR gamma receptor protein is expressed in primary myeloid and lymphoid leukemias and in lymphoma and myeloma cell lines. In this study, we compared the activity of several PPAR gamma ligands including BRL49653 (rosiglitazone), 15-deoxy-Delta 12,14-prostaglandin J(2), and the novel triterpenoid 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid on leukemia cells. Exposure to these PPAR gamma ligands induced apoptosis in myeloid (U937 and HL-60) and lymphoid (Su-DHL, Sup-M2, Ramos, Raji, Hodgkin's cell lines, and primary chronic lymphocytic leukemia) cells. A similar exposure to these PPAR gamma ligands induced the differentiation of myeloid leukemic cells. A combination of PPAR gamma ligands with a retinoid X receptor agonist (i.e., LG100268) or a retinoic acid receptor agonist (i.e., all trans-retinoic acid) enhanced differentiating and growth-inhibitory effects. 2-Cyano-3,12-dioxooleana-1,9-dien-28-oic acid induced differentiation and apoptosis with much greater potency than the other PPAR gamma ligands in established cell lines and primary chronic lymphocytic leukemia samples. Exposure to 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid induced mitochondrial depolarization and caspase activation, which was associated with apoptosis induction. In Bcl-2-overexpressing chronic lymphocytic leukemia cells, the small-molecule Bcl-2 inhibitor HA14-1 sensitized these cells to 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid-induced apoptosis. These results suggest that PPAR gamma ligation alone and in combination with retinoids holds promise as novel therapy for leukemias by activating the transcriptional activity of target genes that control apoptosis and differentiation in leukemias.

Agar↗
PubMed2004

[Cloning and expression analysis in mature individuals of salmon gonadotropin-releasing hormone (sGnRH) gene in common carp].

Two types of complementary DNAs (cDNA) encoding the precursor of salmon gonadotropin-releasing hormone (sGnRH, [Trp7, Leu8] GnRH) are cloned and sequenced from common carp brain using rapid amplification of cDNA ends (RACE). The two cDNAs are referred to sGnRH cDNA1 and cDNA2, and the full-length fragment of cDNA1 and cDNA2 were 393 and 478 bp, respectively. Two sGnRH cDNAs contain an open reading frame of 285 bp, which encodes the sGnRH precursor including 94 amino acid residues. The sGnRH precursors consist of a signal peptide, sGnRH decapeptide and a GnRH-associated peptide (GAP) which is linked by the processing site (Gly-Lys-Arg). Two different sGnRH genes are characterized by intron trapping, and they share a similar structure composed of four exons and three introns. The nucleotide sequences identity of intron 1, intron 2 and intron 3 in sGnRH gene1 and gene2 are 71.1, 76. 1 and 88.0%, respectively. The basic structure and encoding architecture of sGnRH cDNAs and genes are similar with the reported GnRH. It is presumed that all the GnRH variants may evolve from a common ancestral molecular. Southern blot results confirm further the conclusion that there are two differential sGnRH genes in common carp genome. The results of reverse transcription-polymerase chain reaction (RT-PCR) assaying show that the two sGnRH genes co-express in the dissected brain regions, pituitary and ovary with the exception of expression of sGnRH genes in testis. According to the co-existence of two sGnRH genes in distinct brain regions,pituitary and ovary, it is presumed that sGnRH plays an important role in the regulation of hypothalamic-pituitary-gonadal (HPG) axis,and that sGnRH also operates as the neuromodulator, autocrine and/or paracrine regulator.

Amino Acid Sequence↗
PubMed2004

[Application of straight wire appliance for pre- and post-surgical orthodontics].

OBJECTIVE: To analyze the surgical patients treated with straight wire appliance for guidelines of clinical using of the appliance. METHODS: Totally 51 patients from Joint Clinic of Orthodontic Surgery, Peking University School of Stomatology with dentofacial deformities treated with straight wire appliance were analyzed. The patients were aged from 15 years to 34 years 5 months, average 18 years 9 months. Among whom, 16 are males, while the other 35 are females. RESULTS: Eighteen patients were treated with extraction of teeth, while other 33 cases were nonextraction case. The duration of average presurgical orthodontic treatment was 13.3 months, and 10.4 months was for postsurgical orthodontic treatment, totally active treatment time was 25.5 months. CONCLUSIONS: Straight wire appliance would benefit a lot for three dimensional control of teeth when doing pre- and post-surgical orthodontic treatment. Good results could be achieved without wire bending.

Adolescent↗
PubMed2003

Cyclo-oxygenases and prostaglandins in acute inflammatory demyelination of the peripheral nerve.

OBJECTIVE: To investigate the expression of cyclo-oxygenases (COX), key enzymes in propagating inflammatory responses by converting arachidonic acid to prostaglandins, in inflammatory demyelinating disorders of the peripheral nervous system (PNS). METHODS: Expression and distribution of COX messenger RNA (mRNA) and protein were studied in sural nerve biopsies, serum, and CSF samples from patients with Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), or, for comparison, with vasculitic neuropathy (VN), which is a inflammatory nondemyelinating disorder, and noninflammatory neuropathies (NIN) using RT-PCR, immunohistochemistry, and immunoblotting. To confirm functional COX-2 activity, the expression of prostaglandin E(2) (PGE(2)) and prostaglandin F(2alpha) (PGF(2alpha)) was evaluated by ELISA ex vivo and in vitro. RESULTS: Whereas COX-1 expression was unaltered in all investigated groups, a significant upregulation of COX-2 mRNA was detected in sural nerves from patients with GBS, CIDP, or VN but not in control subjects with noninflammatory disorders. Macrophages were identified as its primary cellular source. Increased COX-2 protein levels were detectable in serum and CSF from all patients with GBS and, in smaller numbers only, in samples from patients with CIDP or VN but not from the NIN group studied. Moreover, increased levels of PGE(2) and PGF(2alpha) were measurable in sera from patients with GBS, CIDP, or VN and in cell culture supernatants from in vitro stimulated macrophages, indicative of COX-2 activity. CONCLUSIONS: Cyclo-oxygenase-2, expressed by macrophages, may generate prostaglandins during acute inflammatory demyelination of the peripheral nerve.

Acute Disease↗
PubMed2003

A phase II study of intravenous exatecan mesylate (DX-8951f) administered daily for 5 days every 3 weeks to patients with advanced ovarian, tubal or peritoneal cancer resistant to platinum, taxane and topotecan.

BACKGROUND: DX-8951f is a water-soluble camptothecin derivative with greater in vivo and in vitro activity than topotecan or irinotecan. The objectives of this phase II study were to determine the antitumor activity, safety and pharmacokinetic profile of DX-8951f administered intravenously for five consecutive days, every 3 weeks in patients with advanced ovarian, tubal and peritoneal cancer resistant to platinum, taxane and topotecan. METHODS: Enrolled in the study at The University of Texas M. D. Anderson Cancer Center were 16 patients with measurable cancer resistant to platinum, taxane and topotecan. All 16 patients were assessable for safety and 15 for efficacy analyses. Treatment consisted of a daily infusion of DX-8951f at 0.3 mg/m(2) per day (except for one minimally pretreated patient who started at 0.5 mg/m(2) per day) over 30 min for five consecutive days every 3 weeks. The pharmacokinetic and excretory profiles of DX-8951, the anhydrous form of DX-8951f, were also characterized. RESULTS: Disease was stable in 7 of 16 patients (44%) (4 minor response and 3 stable disease). The median time to tumor progression was 43 days (95% CI 37-92 days). The median overall survival was 117 days (95% CI 90-279 days). The main toxic effect was neutropenia and leukopenia with 50% of patients experiencing grade 3 or 4 neutropenia and leukopenia. One episode of neutropenic fever was observed. Grade 3 or more anemia and thrombocytopenia were seen in 25% and 13% of patients, respectively. Grade 3 nonhematologic side effects included nausea (25% of patients) and fatigue (19%). Other side effects were not more than grade 2, and included gastrointestinal dysfunction, stomatitis, dermatitis, alopecia, liver dysfunction and drug fever. DX-8951 displayed linear pharmacokinetic characteristics at the doses administered. The average plasma clearance, total volume of distribution, and terminal elimination half-life were 2.1 l/h per m(2), 20 l/m(2) and 9.5 h, respectively. CONCLUSIONS: DX-8951f administered parenterally as a single agent daily at a dose of either 0.5 or 0.3 mg/m(2) per day for 5 days is feasible in patients with advanced ovarian, tubal and peritoneal cancer resistant to platinum, taxane and topotecan. Although no responses were observed, a significant number of patients had stable disease with a decrease in CA-125 levels. In this heavily pretreated population, DX-8951f has clinically relevant hematologic and gastrointestinal toxicities in about 25% of patients. DX-8951 appeared to have linear pharmacokinetic characteristics on the basis of multiple administrations.

Adult↗
PubMed2003

rIFN-gamma-mediated growth suppression of platinum-sensitive and -resistant ovarian tumor cell lines not dependent upon arginase inhibition.

BACKGROUND: Arginine metabolism in tumor cell lines can be influenced by various cytokines, including recombinant human interferon-gamma (rIFN-gamma), a cytokine that shows promising clinical activity in epithelial ovarian cancer (EOC). METHODS: We examined EOC cell lines for the expression of arginase in an enzymatic assay and for transcripts of arginase I and II, inducible nitric oxide synthase (iNOS), and indoleamine 2,3-dioxygenase (IDO) by reverse transcription-polymerase chain reaction. The effects of rIFN-gamma on arginase activity and on tumor cell growth inhibition were determined by measuring [3H]thymidine uptake. RESULTS: Elevated arginase activity was detected in 5 of 8 tumor cell lines, and analysis at the transcriptional level showed that arginase II was involved but arginase I was not. rIFN-gamma reduced arginase activity in 3 EOC cell lines but increased activity in the 2008 cell line and its platinum-resistant subline, 2008.C13. iNOS transcripts were not detected in rIFN-gamma-treated or untreated cell lines. In contrast, IDO activity was induced or increased by rIFN-gamma. Suppression of arginase activity by rIFN-gamma in certain cell lines suggested that such inhibition might contribute to its antiproliferative effects. However, supplementation of the medium with polyamine pathway products did not interfere with the growth-inhibitory effects of rIFN-gamma EOC cells. CONCLUSIONS: Increased arginase activity, specifically identified with arginase II, is present in most of the tested EOC cell lines. rIFN-gamma inhibits or stimulates arginase activity in certain EOC cell lines, though the decrease in arginase activity does not appear to be associated with the in vitro antiproliferative activity of rIFN-gamma. Since cells within the stroma of EOC tissues could also contribute to arginine metabolism following treatment with rIFN-gamma or rIFN-gamma-inducers, it would be helpful to examine these effects in vivo.

Journal Article↗
PubMed2003

Evolutionary and biomedical implications of a Schistosoma japonicum complementary DNA resource.

Schistosoma japonicum causes schistosomiasis in humans and livestock in the Asia-Pacific region. Knowledge of the genome of this parasite should improve understanding of schistosome-host interactions, biomedical aspects of schistosomiasis and invertebrate evolution. We assigned 43,707 expressed sequence tags (ESTs) derived from adult S. japonicum and their eggs to 13,131 gene clusters. Of these, 35% shared no similarity with known genes and 75% had not been reported previously in schistosomes. Notably, S. japonicum encoded mammalian-like receptors for insulin, progesterone, cytokines and neuropeptides, suggesting that host hormones, or endogenous parasite homologs, could orchestrate schistosome development and maturation and that schistosomes modulate anti-parasite immune responses through inhibitors, molecular mimicry and other evasion strategies.

Amino Acid Sequence↗
PubMed2003

Aberrant methylation and silencing of ARHI, an imprinted tumor suppressor gene in which the function is lost in breast cancers.

ARHI is a maternally imprinted tumor suppressor gene that maps to a site on chromosome 1p31 where loss of heterozygosity has been observed in 40% of human breast and ovarian cancers. ARHI is expressed in normal ovarian and breast epithelial cells, but ARHI expression is lost in a majority of ovarian and breast cancers. Expression of ARHI from the paternal allele can be down-regulated by multiple mechanisms in addition to loss of heterozygosity. This article explores the role of DNA methylation in silencing ARHI expression. There are three CpG islands in the ARHI gene. CpG islands I and II are located in the promoter region, whereas CpG island III is located in the coding region. Consistent with imprinting, we have found that all three CpG islands were partially methylated in normal human breast epithelial cells. Additional confirmation of imprinting has been obtained by studying DNA methylation and ARHI expression in murine A9 cells that carry either the maternal or the paternal copy of human chromosome 1. All three CpG islands were methylated, and ARHI was not expressed in A9 cells that contained the maternal allele. Conversely, CpG islands were not methylated and ARHI was expressed in A9 cells that contained the paternal allele of human chromosome 1. Aberrant methylation was found in several breast cancer cell lines that exhibited decreased ARHI expression. Hypermethylation was detected in 67% (6 of 9) of breast cancer cell lines at CpG island I, 33% (3 of 9) at CpG island II, and 56% (5 of 9) at CpG island III. Hypomethylation was observed in 44% (4 of 9) of breast cancer cell lines at CpG island II. When methylation of CpG islands was studied in 20 surgical specimens, hypermethylation was not observed in CpG island I, but 3 of 20 cases exhibited hypermethylation in CpG island II (15%), and 4 of 20 cases had hypermethylation in CpG island III (20%). Treatment with 5-aza-2'-deoxycytidine, a methyltransferase inhibitor, could reverse aberrant hypermethylation of CpG island I, II and III and partially restore ARHI expression in some, but not all of the cell lines. Treatment with 5-aza-2'-deoxycytidine partially reactivated ARHI expression in cell lines with hypermethylation of CpG islands I and II but not in cell lines with partial methylation or hypomethylation of these CpG islands. To test the impact of CpG island methylation on ARHI promoter activity more directly, constructs were prepared with the ARHI promoter linked to a luciferase reporter and transfected into SKBr3 and human embryo kidney 293 cells. Methylation of the entire construct destroyed promoter activity. Selective methylation of CpG island II alone or in combination with CpG island I also abolished ARHI promoter activity. Methylation of CpG I alone partially inhibited promoter activity of ARHI. Thus, hypermethylation of CpG island II in the promoter region of ARHI is associated with the complete loss of ARHI expression in breast cancer cells. Other epigenetic modifications such as hypermethylation in CpG island III may also contribute to the loss of ARHI expression.

Alleles↗
PubMed2003

Cloning and characterization of a mouse endoplasmic reticulum alkaline ceramidase: an enzyme that preferentially regulates metabolism of very long chain ceramides.

Ceramidases deacylate ceramides, important intermediates in the metabolic pathway of sphingolipids. In this study, we report the cloning and characterization of a novel mouse alkaline ceramidase (maCER1) with a highly restricted substrate specificity. maCER1 consists of 287 amino acids, and it has a 28 and 32% identity to the Saccharomyces alkaline ceramidases (YPC1p and YDC1p) and the human alkaline phytoceramidase, respectively. Reverse transcriptase-PCR analysis demonstrated that maCER1 was predominantly expressed in skin. maCER1 was localized to the endoplasmic reticulum as revealed by immunocytochemistry. In vitro biochemical characterization determined that maCER1 hydrolyzed D-erythro-ceramide exclusively but not D-erythro-dihydroceramide or D-ribo-phytoceramide. Similar to other alkaline ceramidases, maCER1 had an alkaline pH optimum of 8.0, and it was activated by Ca2+ but inhibited by Zn2+,Cu2+, and Mn2+. maCER1 was also inhibited by sphingosine, one of its products. Metabolic labeling studies showed that overexpression of maCER1 caused a decrease in the incorporation of radiolabeled dihydrosphingosine into ceramide and complex sphingolipids but led to a concomitant increase in sphingosine-1-P (S1P) in HeLa cells. Mass measurement showed that overexpression of maCER1 selectively lowered the cellular levels of D-erythro-C24:1-ceramide, but not other ceramide species and caused an increase in the levels of S1P. Taken together, these data suggest that maCER1 is a novel alkaline ceramidase with a stringent substrate specificity and that maCER1 is selectively expressed in skin and may have a role in regulating the levels of bioactive lipids ceramide and S1P, as well as complex sphingolipids.

Alkalies↗
PubMed2003

Proteomic identification of heat shock protein 70 as a candidate target for enhancing apoptosis induced by farnesyl transferase inhibitor.

Farnesyl transferase inhibitors (FTIs) are novel antitumor drugs with clinical activity. FTIs inhibit cell growth not only by preventing direct Ras farnesylation but also through a Ras-independent pathway. Proteomics has been shown to be a powerful tool to monitor and analyze molecular networks and fluxes within the living cells and to identify the proteins that participate in these networks upon perturbation of the cellular environment. To observe early and dynamic protein changes in the cellular response to FTI in ovarian cancer cells, total proteins were extracted from 2774 cells treated or not with 10 microM manumycin, an FTI, for 3, 6 and 16 h. The proteins in the cells that were differentially expressed following treatment with manumycin for 3, 6 and 16 h were noted by two-dimensional electrophoresis and further identified by peptide mass fingerprinting as stress proteins. Both heat shock protein 70 (HSP70) and altered HSP70 were significantly up-regulated as early as 16 h in 2774 cells after exposure to manumycin. Since HSP70 plays an important role in protecting cells under stress, we treated the 2774 cells with the HSP inhibitor quercetin in combination with FTI. Quercetin dramatically enhanced the manumycin-mediated apoptosis in 2774 cells. Inducible HSP70 by manumycin in surviving ovarian cancer cells was also inhibited by quercetin as demonstrated by enzyme-linked immunosorbent assay. The inhibition of HSP70 by quercetin was correlated with enhancement of manumycin-induced mediated apoptosis in 2774 cells. The inhibition of HSP70 by 50 microM quercetin was also correlated with a decreased expression of procaspase-3 and enhancement of specific cleavage of poly (ADP-ribose) polymerase into apoptotic fragment in 2774 cells treated with manumycin. The interaction between the HSP70 inhibitor and FTI confirms the functional significance of the up-regulation of HSP70 as a protective mechanism against FTI-induced apoptosis and provides the framework for combination treatment of ovarian cancer.

Alkyl and Aryl Transferases↗
PubMed2003

Phase II study of cetrorelix, a luteinizing hormone-releasing hormone antagonist in patients with platinum-resistant ovarian cancer.

OBJECTIVE: The goal of this work was to study the anticancer activity of cetrorelix, a decapeptide with LHRH receptor antagonist properties in patients with platinum-resistant ovarian cancer. About 80% of primary ovarian cancers and cell lines bear LHRH receptors. Cetrorelix has anticancer activity in in vitro and in vivo ovarian cancer models. METHODS: Eligible patients with ovarian or mullerian carcinoma resistant to platinum chemotherapy received cetrorelix 10 mg subcutaneously every day. Eligibility criteria included age > or = 18, PS < or = 2, measurable disease, chemistries and blood counts in normal range, no estrogen replacement for at least 2 weeks, and no known allergic reactions to extrinsic peptide. In patients volunteering for a biopsy, tissue was taken to perform a LHRH receptor assay. RESULTS: Seventeen patients were treated. Median age was 58 years. Median performance status was 0. Median number of prior chemotherapies was 3. Three patients had partial remissions lasting 9, 16, and 17 weeks. Toxicities effects included grade 4 anaphylactoid reaction (one patient) controlled by cortisol and cimetidine, grade 2 histamine reaction (two patients), grade 2 arthralgia (one patient) 20% cholesterol increase (two patients, who did not require specific treatment), minor hot flushes, headache, and local skin reaction at the injection site. Six of seven samples were LHRH receptor positive for mRNA and/or ligand assay. Two responding patients were LHRH receptor positive. The patient who had no receptor did not respond. CONCLUSION: Cetrorelix has activity against ovarian cancer in this refractory population, and has minimal toxicity, except for potential anaphylactoid reactions. Activity may be mediated through the LHRH receptor.

Aged↗
PubMed2003

Autoimmunity as the consequence of a spontaneous mutation in Rasgrp1.

A mouse strain was identified with a recessive genetic lesion, which spontaneously developed a lymphoproliferative autoimmune syndrome exhibiting features of systemic lupus erythematosus. Positional mapping of the disease-associated locus revealed a lesion in Rasgrp1 that prevented the translation of the RasGRP1 protein. T cells from these mice failed to activate Ras or proliferate vigorously following antigen encounter and showed defects in positive selection. Peripheral RasGRP1lag T cells spontaneously adopted a memory phenotype and were able to transfer disease to lymphopenic recipient mice. CD4+ T cells accumulated in the lymphoid tissues of older RasGRP1lag mice and were resistant to activation-induced cell death. RasGRP1lag B cells were functionally normal, but activated B cells were detected in older mice, as were autoantibodies directed against self-antigens. Our findings indicate that Ras signaling pathways are required to maintain T cell tolerance and to prevent autoimmune disease.

Animals↗
PubMed2003

Anticancer therapy targeting the apoptotic pathway.

Apoptosis, or programmed cell death, has an essential role in controlling cell number in many developmental and physiological settings and in chemotherapy-induced tumour-cell killing. It is a genetically regulated biological process, guided by the ratio of proapoptotic and antiapoptotic proteins. Recently, inducers of apoptosis have been used in cancer therapy. Several studies have attempted to induce apoptosis by triggering the tumour-necrosis-factor-related apoptosis-inducing ligand receptor and the BCL2 family of proteins, and others have targeted the caspases, and proteins that inhibit apoptosis. Most of these therapies are still in preclinical development because of their low efficacy and susceptibility to drug resistance, but some of them have shown promising results. In this article, we review the development and clinical efficacy of proapoptotic drugs that have shown promise.

Antineoplastic Agents↗
PubMed2003

Biologically active human interferon alpha-2b produced in the egg white of transgenic hens.

We have previously described the expression of a bacterial protein in the egg white of transgenic chickens using a replication-deficient retroviral vector. Here we report the expression of a glycosylated human protein, interferon alpha-2b (hIFN), in the egg white of transgenic hens. The hIFN secreted into the egg white was biologically active as determined by a viral inhibition assay. Purification and carbohydrate analysis of the hIFN expressed in egg white revealed that two of the six major glycosylated hIFN species match the naturally occurring human hIFN glycovariants. These results support the potential of the hen as a bioreactor for the production of commercially valuable, biologically active, and glycosylated proteins in egg white.

Animals↗
PubMed2003

Isolation, sequence analysis, and expression studies of florally expressed cDNAs in Arabidopsis.

Molecular genetics has identified dozens of genes that regulate flower development in Arabidopsis. However, the complexity of flower development suggests that many other genes are yet to be uncovered. To identify floral genes that are expressed at low levels in the flower, we have sequenced 1587 cDNA fragments from a subtractive floral cDNA library. A total of 1222 unique genes represented by these ESTs are distributed on all five chromosomes with similar frequencies as all predicted genes in the genome. Among these, 17 genes were shown to be expressed anywhere for the first time because they were not found in previous EST and full-length cDNA datasets. Furthermore, 724 of the genes revealed by this library were not definitively shown to be expressed in the flower by previous floral EST datasets. In addition, 49 transcriptional regulators, 31 protein kinases, 12 zinc-finger proteins and other signaling proteins were found to be present in floral buds. Moreover, the EST sequences likely extended the transcribed regions of 26 previously annotated genes, and may have uncovered several previously unrecognized genes. To obtain additional clues about possible gene function, we hybridized cDNA microarray with probes derived from wild-type Arabidopsis rosette leaves and floral buds. We estimated that over 50% of genes were expressed at levels lower than 1/30 of the highest detectable signal intensity, indicating that many floral genes are expressed at low levels. Furthermore, 97 genes were found to be expressed at a higher level in the flower than the leaf by the Significance Analysis of Microarray (SAM) method with a 1.0% false discovery rate (FDR). Further RT-PCR analyses of selected genes support the microarray results. We suggest that the genes encoding putative regulatory proteins and at least some proteins with currently unknown functions might play important roles during flowering.

Arabidopsis↗
PubMed2003

Establishment and characterization of cancer cell cultures and xenografts derived from primary or metastatic Mullerian cancers.

PURPOSE: The purpose of this study was to characterize cell cultures and xenografts derived from patients with ovarian cancer. EXPERIMENTAL DESIGN: Ninety specimens from 67 patients were plated in RPMI 1640 or inoculated in nude mice. Growth characteristics of cell cultures and xenografts were determined. Expression of receptors for estrogen, progesterone, androgen, epithelial growth factor, fibroblast growth factor, HER-2/erbB-2/c-neu proto-oncogene, and the P53 expression were characterized by immunocytochemistry in 28 cell cultures. RESULTS: Forty-nine percent of samples were cultured successfully in vitro. Ascitic and pleural effusion specimens were more likely to produce a cell culture or a xenograft than solid tissue specimens (P < 0.005). All of the cell cultures had an epithelial morphology, and 89% were aneuploid with a mean DNA index of 1.6 (range, 0.9-3.0). Of 54 and 61 specimens inoculated into nude mice i.p. and s.c., 15 (28%) and 18 (30%) produced a xenograft, respectively, with two-thirds of these xenografts being reproducibly tumorigenic. The median time to first passage was 21 weeks for cell cultures and 8-12 weeks for xenografts. Expression of epithelial growth factor receptor, HER-2/erbB-2/c-neu proto-oncogene, fibroblast growth factor receptor, estrogen, progesterone, and androgen was seen in 24, 21, 31, 17, 43, and 18%, respectively. P53 was overexpressed in 62% of cell cultures analyzed. CONCLUSIONS: Ovarian cancer cells collected from effusions are easier to grow in vitro than in vivo. The only characteristic that may be associated with tumorigenicity was abnormal P53 expression. This panel of ovarian cancer materials provides useful models for biological or therapeutical studies.

Animals↗