Chemo-response biomarker discovery via expression profiling using soft-tissue sarcoma xenografts

9569

Background: Soft-tissue sarcoma (STS) constitute a heterogeneous group of tumours of mesenchymal origin. Whereas the mainstay of treatment has been surgery and radiation, these tumours are generally considered as quite chemoresistant. However, it is well known that subgroups of patients benefit from chemotherapy. Markers that could predict drug response would therefore be beneficial for the management of this malignancy. We have previously established panel of 17 unique human soft tissue xenografts, representing 7 different histological subgroups and assessed their responsiveness to doxorubicin, ifosfamide, etoposide, and cisplatin. We wanted to utilize these xenografts as a model system to discover for novel candidate marker genes for STS chemo-response. Methods: GE Uniset Human 20K microarrays were used to obtain gene expression profiles from the each xenografts. One-way ANOVA test with a Benjamini-Hochberg multiple test correction allowing a false discovery rate of 5% was used to identify genes with significantly differential expression. Results: Doxorubicin, ifosfamide, etoposide and cisplatin were efficient in 6/17, 10/17, 1/17 and 7/17 xenografts respectively. However, in the expression profiles obtained none of the genes showed significantly correlation with chemo-responsiveness to any of the drugs. Two of the xenografts, TAX 1 and TAX 2, both originate from a malignant fibrous histiocytoma (MFH) in the same patient, but show strikingly different sensitivity to ifosfamide (TAX1 resistant, TAX2 sensitive). When triplicate hybridizations of TAX1 and 2 were compared, 294 genes met the above criteria. In addition we identified a subset of 122 genes that were flagged absent in one of the specimens, present in the other. Among genes with an already described role in mediating drug resistance are GST-pi and glutathione peroxidase. Taken together, these results indicate that discovery of general response markers in STSs may be difficult due to the heterogeneity of the different subgroups constituting this malignancy. Conclusions: Gene expression profiling of the TAX 1 and TAX 2 xenografts revealed a number of interesting candidate marker genes for ifosfamide sensitivity of MFH. This list of genes will be further refined by validation in clinical samples.

No significant financial relationships to disclose.

MBD4 and SEI1 as new prognostic markers in colorectal cancer patients receiving adjuvant 5-fluorouracil

20085

Background: Previous studies from our laboratory have identified a number of marker genes associated with chemosensitivity to 5-fluorouracil (5-FU). In this study, the in vivo significance of several marker genes in terms of prognostic potential were evaluated using colorectal cancer patient samples treated with 5-FU based therapy. Eight marker genes were selected based on their functional roles and significant fold changes in expression. They are SERTA domain containing 1(SEI1), Ribonucleotide reductase M2 polypeptide (RRM2), Origin recognition complex, subunit 6 homolog-like (ORC6L), Eukaryotic translation initiation factor 4E (EIF4E), Thymidylate Synthase (TS), SET and MYND domain containing 3 (SMYD3), Dickkopf homolog 4 (DKK4) and Methyl-CpG binding domain protein 4 (MBD4). Methods: Forty eight snap frozen clinical colorectal samples (24 normal and 24 paired colorectal cancer patient samples) were selected with detailed clinical follow-up information. cDNAs were synthesized and the expression levels of marker genes were quantified via qRT-PCR analysis. The statistical significance of these markers for disease prognosis was evaluated using two tailed paired T-test. Kaplan-Meier survival curve was generated and analyzed by Logrank test. Results: Based on the quantitative expression analysis, RRM2 (p = 0.0001, 95% CI, 2.0 to 4.5), ORC6L (p = 0.0001, 95% CI, 1.8 to 4.6), EIF4E (p = 0.0002, 95% CI, 0.3 to 0.9), TS (p = 0.0005, 95% CI, 0.7 to 2.2) and SMYD3 (p = 0.0001, 95% CI, 0.8 to 1.5) was over-expressed in tumor tissues. However, the expression of SEI1 was decreased in tumors (p = 0.02, 95% CI, 0.1 to 1.3), consistent with the function of SEI1 as a potential tumor suppressor. Kaplan-Meier survival analysis indicated that MBD4 is a significant prognostic factor for patient’s survival (p = 0.03). MBD4 was a key protein involved in DNA methylation. The expression of TS was associated with tumor stage as it had significant higher expression level in UICC stage I and II compared to stage IV patients (p = 0.03). Conclusion: MBD4 may be potential novel prognostic markers for predicting patient survival for colorectal cancer.

No significant financial relationships to disclose.

Noncoding miRNAs as novel prognostic factor for 5-fluorouracil adjuvant therapy in colorectal cancer

3609

Background: The roles of non-coding miRNAs in tumorgenesis are just emerging. miRNAs regulate gene expression at post-transcriptional level by influencing translation efficiency of their target mRNAs. Previous studies from our laboratory have identified a number of miRNAs that were dis-regulated in colon cancer cell lines related to the loss of p53 tumor suppressor gene. In this study, the in vivo significance of some of these miRNAs was further evaluated using clinical samples. Ten miRNAs (hsa-let-7b, hsa-let-7g, hsa-miR-15b, hsa-miR-181b, hsa-miR-191, hsa-miR-200c, hsa-miR-26a, hsa-miR-27a, hsa-miR-30a-5p and hsa-miR-30c) were evaluated for their potential prognostic value in colorectal cancer patients receiving 5-fluorouracil (5-FU) based therapy. Methods: Forty eight snap frozen clinical colorectal samples (24 normal and 24 paired colorectal cancer patient samples) were selected with detailed clinical follow-up information. RNAs were isolated from these samples using TRIzol reagent. After cDNA synthesis with miRNA specific primers, the expression levels of 10 miRNAs were quantified via qRT-PCR analysis. The statistical significance of these markers for disease prognosis was evaluated using two tailed paired T-test. Kaplan-Meier survival curve was generated and followed by Logrank test. Result: Among the ten miRNAs, hsa-miR-15b (p=0.02), hsa-miR-181b (p=0.01), hsa-miR-191 (p=0.03) and hsa-miR-200c (p=0.005) were significantly over-expressed in tumors compared to normal colorectal samples. Kaplan-Meier survival analysis indicates that hsa-miR-200c was a significant prognostic marker for predicting patient’s survival (p=0.01). The patients (n=15) with higher hsa-miR-200c expression had shorter survival interval (median survival = 26 months) compared to patients (n=9) with lower expression (median survival = 38 months). Conclusions: Some of these miRNAs may function as oncogenes due to their over-expression in tumors. Hsa-miR-200c may be a potential novel prognostic factor for 5-FU based chemotherapy in colorectal cancer.

No significant financial relationships to disclose.

Gene expression profiles classifies the responsiveness of human osteosarcoma to doxorubicin, cisplatin and ifosfamide

9534

Background: Despite the increased survival rates of osteosarcoma patients attributed to adjuvant chemotherapy, at least one third of the patients still succumb to their disease. Furthermore, ultra-aggressive combination chemotherapy is associated with considerable acute and long term toxicity. This is of particular concern in patients who may be cured by a simpler and less toxic regimens or do not have micrometastatic disease. Hence, further improvements in the management of osteosarcoma seemingly depend on diagnostic and prognostic tools that may allow for a more risk adapted and individualized treatment. Methods: We have used GE Uniset Human 20K microarrays to obtain gene expression profiles from a panel of ten unique human osteosarcoma xenografts. For each of the three drugs doxorubicin, cisplatin or ifosfamide the xenografts were grouped according to their response to chemotherapy, resistant, weakly sensitive or sensitive. For each individual drug, a one-way ANOVA test with a Benjamini and Hochberg multiple test correction allowing a false discovery rate of 5% (doxorubicin, cisplatin) or 2% (ifosfamide) was used to identify genes with significantly differential expression. In addition a 2-fold cut off was applied to exclude smaller but yet significant differences. Results: For doxorubicin and cisplatin, respectively 59 and 120 genes met these criteria. The expression levels of 25 genes overlapped between these two groups. For ifosfamide, 148 genes were selected, for 5 of them the expression overlapped with cisplatin sensitivity related genes. In the lists, genes involved in mediating and regulating apoptosis were abundant, such as regulators of TGF signaling, ubiquitin mediated protein degradation and members of the immediate early response protein family. Several genes which products interact with components of the cytoskeleton were also identified. Conclusion: We have used a unique strategy to screen for potential chemosensitivity markers by utilizing xenografts as training sets.

No significant financial relationships to disclose.

Properties of elliptical-core two-mode fiber

Polarization and modal birefringence of elliptical-core two-mode fibers are investigated. Wavelengths corresponding to zero group delay difference (GDD) between the two spatial modes and between the orthogonal polarizations are computed when the fiber parameters, i.e., the relative core/cladding index difference and the ratio of major over minor axis, are varied. Simple relationships between the zero GDD wavelengths and fiber parameters are obtained. With proper fiber design, zero GDD between the two spatial modes and the two orthogonal polarizations can be achieved at the same wavelength.

A tissue sealant based on reactive multifunctional polyethylene glycol

A rapidly gelling synthetic tissue sealant was developed from tetra-succinimidyl and tetra-thiol-derivatized polyethylene glycol (PEG). The two reagents were dissolved in aqueous buffers at 20% (w/v) solids and sprayed on the tissue site, with the use of a sprayer/mixer device. Good adhesion to collagen membranes, PTFE grafts, and carotid artery was observed in vitro. In a burst test on collagen membranes with a 2-mm orifice defect, the gel sustained fluid pressures of 125 +/- 36 mm Hg (n = 18), fivefold greater than capillary blood pressure and one-half that observed in hypertension. On 0.4-mm-diameter puncture defects in PTFE grafts, pressures of 390-490 mm Hg were sustained, and on 0.6-0.9-mm puncture defects in carotid arteries, pressures of 490 to 840 mm Hg were sustained. In vitro data corresponded to results in vivo, where bleeding in rabbit arteries was stopped immediately in five out of six trials. A significant reduction in time to hemostasis and blood loss, compared to controls, was observed. Carotid artery and subcutaneous implant data in rabbits showed that the formula was compatible with biological tissue. Rapid gelling and effective sealing were dependent on the presence of active succinimidyl ester and thiol groups on PEG. HPLC and chemical substitution methods were useful in predicting whether batches of derivatized PEG would perform satisfactorily.

Ancestral divergence, genome diversification, and phylogeographic variation in subpopulations of sorbitol-negative, beta-glucuronidase-negative enterohemorrhagic Escherichia coli O157

The O157:H7 lineage of enterohemorrhagic Escherichia coli is a geographically disseminated complex of highly related genotypes that share common ancestry. The common clone that is found worldwide carries several markers of events in its evolution, including markers for acquisition of virulence genes and loss of physiological characteristics, such as sorbitol fermentation ability and beta-glucuronidase production. Populations of variants that are distinct with respect to motility and the sorbitol and beta-glucuronidase markers appear to have diverged at several points along the inferred evolutionary pathway. In addition to these variants, distinct subpopulations of the contemporary non-sorbitol-fermenting, beta-glucuronidase-negative O157:H7 clone were recently detected among bovine and human clinical isolates in the United States by using high-resolution genome comparison. In order to determine if these recently described subpopulations were derived from a regional or ancestral divergence event, we used octamer-based genome scanning, marker sorting, and DNA sequence analysis to examine their phylogenetic relationship to populations of non-sorbitol-fermenting, beta-glucuronidase negative O157:H7 and O157:H- strains from Australia. The inferred phylogeny is consistent with the hypothesis that subpopulations on each continent resulted from geographic spread of an ancestral divergence event and subsequent expansion of distinct subpopulations. Marker sorting and DNA sequence analyses identified sets of monophyletic markers consistent with the pattern of divergence and demonstrated that phylogeographic variation occurred through emergence of regional subclones and concentration of regional polymorphisms among distinct subpopulations. DNA sequence analysis of representative polyphyletic markers showed that genome diversity accrued through random drift and bacteriophage-mediated events.

DNA sequencing using biotinylated dideoxynucleotides and mass spectrometry

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MS) has been explored widely for DNA sequencing. The major requirement for this method is that the DNA sequencing fragments must be free from alkaline and alkaline earth salts as well as other contaminants for accurately measuring the masses of the DNA fragments. We report here the development of a novel MS DNA sequencing method that generates Sanger-sequencing fragments in one tube using biotinylated dideoxynucleotides. The DNA sequencing fragments that carry a biotin at the 3'-end are made free from salts and other components in the sequencing reaction by capture with streptavidin-coated magnetic beads. Only correctly terminated biotinylated DNA fragments are subsequently released and loaded onto a mass spectrometer to obtain accurate DNA sequencing data. Compared with gel electrophoresis-based sequencing systems, MS produces a very high resolution of DNA-sequencing fragments, fast separation on microsecond time scales, and completely eliminates the compressions associated with gel electrophoresis. The high resolution of MS allows accurate mutation and heterozygote detection. This optimized solid-phase DNA-sequencing chemistry plus future improvements in detector sensitivity for large DNA fragments in MS instrumentation will further improve MS for DNA sequencing.

Combinatorial fluorescence energy transfer tags for multiplex biological assays

We report an approach for developing combinatorial fluorescence energy transfer (CFET) tags by tuning the tags' fluorescence emission signatures. The tags can all be excited at a single wavelength and analyzed by a simple optical system. We constructed eight CFET tags with unique fluorescence signatures, detected by a three-color capillary array electrophoresis (CAE) system with 488 nm excitation, using only three fluorescent dyes. A 1',2'-dideoxyribose phosphate spacer was used to separate the donor and acceptor to tune the energy transfer efficiency, generating unique fluorescence signatures. The spacer also served as an electrophoretic mobility tag to tune the mobility of CFET-labeled DNA for multiplex detection of single-nucleotide polymorphisms (SNPs). Six nucleotide variations were identified simultaneously using six CFET tags on synthetic DNA templates and on a PCR product from the retinoblastoma tumor suppressor gene.

[Degradation of phenanthrene and pyrene in contaminated soil by immobilized Zoogloea sp. and Fusarium sp]

Immobilized with PVA, sodium alginate and activated carbon, both Zoogloea sp. and Fusarium sp. strains could degrade phenanthrene and pyrene efficiently. The optimal carrier was made of 100 rho.g-1 L PVA, 5 sodium alginate rho.g-1 L and 50 activated carbon rho.g-1 L. The degradation rates of phenanthrene and pyrene in 10 days were 87.48% and 75.34% by the immobilized bacterium, 37.04% and 20.85% higher than those by the free bacterium, and the rates in 15 days were 84.36% and 74.87% by the immobilized fungus, 5.35% and 11.23% higher than those by the free fungus.

Clinical study on treatment of chronic renal failure with shenshuailing

The therapeutic effects of Shenshuailing Kou Fu Ye (SKFY [symbol: see text], the Oral Liquid for Renal Failure) and Shenshuailing Guan Chang Ye (SGCY [symbol: see text], the Enema for Renal Failure) were evaluated in treatment of chronic renal failure, with coateg aldehyde oxystarch as the controls. The changes in the clinical symptoms, serum creatinine, blood urea nitrogen and creatinine clearance rate were observed. The total effective rate in the former was 90.46%, and the latter 60.43%.

A clinical investigation on garlicin injectio for treatment of unstable angina pectoris and its actions on plasma endothelin and blood sugar levels

To investigate the therapeutic effects and mechanisms of garlicin for treatment of unstable angina pectoris (UAP), garlicin injectio was intravenously dripped 60 mg/day in 34 cases for 10 days. Nitroglycerine was used in 21 cases of the control group. The results showed that the total effective rates in improving symptoms and electrocardiogram after garlicin treatment were respectively 82% and 62%, and that the plasma endothelin and blood sugar levels were markedly lowered in cases with hyperglycemia.

[Clinical study on Shenning Mixture in treating IgA nephropathy]

OBJECTIVE

To study the clinical therapeutic effect of Shenning Mixture (SNM) in treating IgA nephropathy.

METHODS

Patients were treated separately with SNM or prednisone by randomized grouping. The criteria, including clinical symptoms, signs, hematuria, albuminuria and immune globulin were observed.

RESULTS

The total effective rate and the complete remission rate in the SNM group were 97.1% and 45.7% respectively, while in the control group, they were 37.1% and 8.6% respectively. Comparison of the two groups showed that the therapeutic effect in the former was better than that in the latter significantly, P < 0.01. The hematuria and albuminuria extenuated and serum IgA lowered more significantly in the SNM group than those in the control group (P < 0.05, P < 0.01).

CONCLUSION

SNM has obvious therapeutic effect on the hematuria and albuminuria in treating IgA nephropathy.

The Bacillus subtilis GTP binding protein obg and regulators of the sigma(B) stress response transcription factor cofractionate with ribosomes

Obg, an essential GTP binding protein of Bacillus subtilis, is necessary for stress activation of the sigma(B) transcription factor. We investigated Obg's cellular associations by differential centrifugation of crude B. subtilis extracts, using an anti-Obg antibody as a probe to monitor Obg during the fractionation, and by fluorescent microscopy of a B. subtilis strain in which Obg was fused to green fluorescent protein. The results indicated that Obg is part of a large cytoplasmic complex. In subsequent analyses, Obg coeluted with ribosomal subunits during gel filtration of B. subtilis lysates on Sephacryl S-400 and specifically bound to ribosomal protein L13 in an affinity blot assay. Probing the gel filtration fractions with antibodies specific for sigma(B) and its coexpressed regulators (Rsb proteins) revealed coincident elution of the upstream components of the sigma(B) stress activation pathway (RsbR, -S, and -T) with Obg and the ribosomal subunits. The data implicate ribosome function as a possible mediator of the activity of Obg and the stress induction of sigma(B).

A model for pulse jet fabric filters

A new model for pulse jet fabric filtration is proposed. In contrast to the earlier model of Ravin and Humphries, which was formulated on the steady state assumption, the present study is aimed at developing a predictive capability for both transient and steady state operations, taking into account the compression effect of filter cakes. The model's relative simplicity allows frequent updating of the model parameter values, thus improving the accuracy of predictions. As a result, the model is particularly useful in developing control algorithms and designing controllers of pulse jet fabric filtration systems.

Correlation of estradiol, parathyroid hormone, interleukin-6, and soluble interleukin-6 receptor during the normal menstrual cycle

Rodent models suggest that estradiol deficiency promotes bone loss through increasing interleukin-6 (IL-6) activity. However, it is controversial as to whether these findings are applicable to humans. To evaluate estradiol-mediated modulation of IL-6 activity in relation to bone metabolism in humans, we measured serum IL-6, soluble interleukin-6 receptor (sIL-6R), estradiol (E2), progesterone, luteinizing hormone, follicle-stimulating hormone, intact parathyroid hormone (PTH), serum and urine Ca, and bone biochemical markers (serum bone-specific alkaline phosphatase, osteocalcin, and serum and urine deoxypyridinoline [Dpd]) across one menstrual cycle for 211 women. Neither IL-6 nor sIL-6R levels differed between the follicular phase (FP) and the luteal phases (LP). However, IL-6 was negatively correlated with E2 during the FP (p =0.003). Furthermore, IL-6 correlated positively with serum Ca over the entire cycle (p = 0.0091. Serum Ca correlated positively with serum (p = 0.040) and urine (p = 0.006) Dpd. PTH was significantly higher during the FP than in the LP (p = 0.004). PTH was negatively related to E2 (p = 0.002), serum Ca (p < 0.001), and urine Ca (p = 0.036), whereas it was positively correlated with IL-6 (p = 0.027). These data demonstrate that IL-6 and PTH fluctuate with E2, and serum II-6 is associated with PTH levels during the menstrual cycle. However, the role of 11-6 in bone remodeling during the normal menstrual cycle remains to be determined.

[Studies of volatile oils from the flowers of Chrysanthemum nankingense and Chrysanthemum indicum]

Chemical constituents of volatile oils from the flowers of Chrysanthemum nankingense and C. indicum were studied by GC-MS. 59, 30 components were identified respectively.

The "pro" sequence of the sporulation-specific sigma transcription factor sigma(E) directs it to the mother cell side of the sporulation septum

sigma(E), a mother cell-specific transcription factor of sporulating Bacillus subtilis, is derived from an inactive precursor protein (pro-sigma(E)). Activation of sigma(E) occurs when a sporulation-specific protease (SpoIIGA) cleaves 27 amino acids from the pro-sigma(E) amino terminus. This reaction is believed to take place at the mother cell-forespore septum. Using a chimera of pro-sigma(E) and green fluorescent protein (GFP) to visualize the intracellular location of pro-sigma(E) by fluorescence microscopy, and lysozyme treatment to separate the mother cell and forespore compartments, we determined that the pro-sigma(E)::GFP signal, localized to the forespore septum prior to lysozyme treatment, is restricted to the mother cell compartment after treatment. Thus, pro-sigma(E)::GFP had been sequestered to the mother cell side of the septum. This segregation of pro-sigma(E)::GFP, and presumably pro-sigma(E), to the mother cell is likely to be the reason why sigma(E) activity is restricted to that compartment.

Sigma factor displacement from RNA polymerase during Bacillus subtilis sporulation

As Bacillus subtilis proceeds through sporulation, the principal vegetative cell sigma subunit (sigma(A)) persists in the cell but is replaced in the extractable RNA polymerase (RNAP) by sporulation-specific sigma factors. To explore how this holoenzyme changeover might occur, velocity centrifugation techniques were used in conjunction with Western blot analyses to monitor the associations of RNAP with sigma(A) and two mother cell sigma factors, sigma(E) and sigma(K), which successively replace sigma(A) on RNAP. Although the relative abundance of sigma(A) with respect to RNAP remained virtually unchanged during sporulation, the percentage of the detectable sigma(A) which cosedimented with RNAP fell from approximately 50% at the onset of sporulation (T(0)) to 2 to 8% by 3 h into the process (T(3)). In a strain that failed to synthesize sigma(E), the first of the mother cell-specific sigma factors, approximately 40% of the sigma(A) remained associated with RNAP at T(3). The level of sigma(A)-RNAP cosedimentation dropped to less than 10% in a strain which synthesized a sigma(E) variant (sigma(ECR119)) that could bind to RNAP but was unable to direct sigma(E)-dependent transcription. The E-sigma(E)-to-E-sigma(K) changeover was characterized by both the displacement of sigma(E) from RNAP and the disappearance of sigma(E) from the cell. Analyses of extracts from wild-type and mutant B. subtilis showed that the sigma(K) protein is required for the displacement of sigma(E) from RNAP and also confirmed that sigma(K) is needed for the loss of the sigma(E) protein. The results indicate that the successive appearance of mother cell sigma factors, but not necessarily their activities, is an important element in the displacement of preexisting sigma factors from RNAP. It suggests that competition for RNAP by consecutive sporulation sigma factors may be an important feature of the holoenzyme changeovers that occur during sporulation.

[Studies on chemical constituents of seeds of Desmos chinensis Lour]

OBJECTIVE

To investigate the chemical constituents of Desmos chinensis.

METHOD

Various column chromatographic techniques were employed for the isolation and purification of constituents from the ethanol extract. The structures were elucidated by spectral analysis.

RESULT

Eleven compounds were isolated and identified as lawinal(1), desmosal(2), desmethoxymatteucinol(3), unonal(4), isounonal(5), desmosflavone(6), allantoic acid(7), succinic acid(8), daucosterol(9), beta-sitosterol(10) and stearic acid(11). The structures of compounds 1 and 2 were reconfirmed by NOEDS technique.

CONCLUSION

Compound 2 is a new natural product and 7, 8 and 9 were found from this plant for the first time.

Changes in bone resorption during the menstrual cycle

To determine if the cyclic changes of female sex hormones during the menstrual cycle are related to changes in bone formation and resorption, we measured serum bone-specific alkaline phosphatase (BAP) and osteocalcin (OC) and bone resorption markers, serum and urine deoxypyridinoline (Dpyr), three times per week during one menstrual cycle in 20 healthy premenopausal women. Serum estradiol (E2) and progesterone (P) showed characteristic cyclic fluctuations. Serum Dpyr was higher during the follicular phase (FP) than in the luteal phase (p = 0.027). Serum BAP, OC, and urine Dpyr levels did not change substantially across the cycle. Serum Dpyr correlated negatively with serum E2 values measured 6 (p = 0.011) and 8 (p = 0.001) days earlier and with P measured concurrently (p = 0.033) 2 (p = 0.002), 4 (p = 0.003), and 6 (p = 0.014) days earlier. BAP correlated negatively with E2 measured 6 days earlier (p = 0.006). We found no statistically significant correlations of E2 or P with OC or urine Dpyr within women over their cycles. BAP was positively correlated with concurrent serum Dpyr (p = 0.015) during the menstrual cycle. Serum OC levels correlated inversely with age (rs = -0.48, p = 0.036). Women with higher mean urine Dpyr levels had higher mean serum OC levels (rs = 0.49, p = 0.033) and showed a trend toward lower hip bone mineral density (rs = -0.40, p = 0.078). We conclude that the low level of E2 and/or P observed during the FP of the normal menstrual cycle is associated with increased bone resorption. These relationships suggest that normal women experience monthly episodes of increased bone resorption from menarche to menopause.

Regulation of p53 expression by thymidylate synthase

Previous studies showed that thymidylate synthase (TS), as an RNA binding protein, regulates its own synthesis by impairing the translation of TS mRNA. In this report, we present evidence that p53 expression is affected in a similar manner by TS. For these studies, we used a TS-depleted human colon cancer HCT-C cell that had been transfected with either the human TS cDNA or the Escherichia coli TS gene. The level of p53 protein in transfected cells overexpressing human TS was significantly reduced when compared with its corresponding parent HCT-C cells. This suppression of p53 expression was the direct result of decreased translational efficiency of p53 mRNA. Similar results were obtained upon transfection of HCT-C cells with pcDNA 3.1 (+) containing the E. coli TS gene. These findings provide evidence that TS, from diverse species, specifically regulates p53 expression at the translational level. In addition, TS-overexpressing cells with suppressed levels of p53 are significantly impaired in their ability to arrest in G1 phase in response to exposure to a DNA-damaging agent such as gamma-irradiation. These studies provide support for the in vivo biological relevance of the interaction between TS and p53 mRNA and identify a molecular pathway for controlling p53 expression.

[Dynamic observation of serological and histological changes of Chinese rhesus monkeys infected by hepatitis G virus]

OBJECTIVE

To study the genesis, development and pathogenesis of hepatitis G.

METHODS

The Chinese Rhesus monkeys were intravenously injected with the serum from a hepatitis G patient only with HGV RNA positive. The dynamic changes of serum and liver tissues of the animals were observed before and after infection. Also the immunohistochemical study were done with monocolonal antibody against NS5 gene antigen of HGV. One male monkey was dissected and the internal organs were taken for histological examination 18 months after infection.

RESULTS

Serum ALT and AST became increasing 30 days after infection and showed abnormal continuously for 9 months. Spotty and focal necrosis and piecemeal necrosis were found in liver tissue from 2 to 18 months after infection. Positive staining of HGV antigen was present in cytoplasm of liver cells by immunohistochemistry. Histological observation showed that the internal organs were normal except the liver tissue in which the damages were similar with that in hepatitis.

CONCLUSION

The successful infection of Chinese Rhesus monkey by serum from hepatitis G patient can used as a good animal model for the study of hepatitis G.

Isoaspartyl bond formation within N-terminal sequences of collagen type I: implications for their use as markers of collagen degradation

An ELISA was developed for the measurement of N-telopeptides of the alpha2(I) collagen chain containing an isomerized Asp-Gly bond (beta-peptide) using polyclonal antibodies raised against the synthetic peptide. The presence of this isomerized form in bone was confirmed by positive immunostaining of sections from human femoral head. The ELISA was used to measure isomerized peptide in both human bone digests and urine samples, showing that an isoaspartyl rearrangement occurs in the Asp-Gly sequence at the N-terminus of the alpha2(I) chain in an analogous fashion to that found in the C-terminal telopeptide of the alpha1(I) chain of collagen. Using this assay in conjunction with a monoclonal antibody ELISA to the non-isomerized alpha2(I) N-telopeptide (alpha-peptide), ratios of isomerized to normal peptides were estimated in the bone and urine samples. Urinary alpha2(I) N-telopeptides showed a higher degree of isomerization than the peptides derived from a human bone digest. This is possibly due to relative enrichment of the isoaspartyl-bonded peptide during metabolic processing due to the proximity of the isoaspartyl bond to a cross-link site. Urinary concentrations of isomerized and normal peptides were determined in normal adults, children, post-menopausal control subjects and subjects with osteoporosis. A lower ratio of beta-peptide to alpha-peptide was observed in children's urine, indicative of a higher rate of bone metabolism allowing less time for the isomerization to occur. No significant differences were found between the post-menopausal control and osteoporotic populations although the trends observed supported the hypothesis that a lower degree of isomerization may be associated with faster bone turnover.

Thymidylate synthase protein and p53 mRNA form an in vivo ribonucleoprotein complex

A thymidylate synthase (TS)-ribonucleoprotein (RNP) complex composed of TS protein and the mRNA of the tumor suppressor gene p53 was isolated from cultured human colon cancer cells. RNA gel shift assays confirmed a specific interaction between TS protein and the protein-coding region of p53 mRNA, and in vitro translation studies demonstrated that this interaction resulted in the specific repression of p53 mRNA translation. To demonstrate the potential biological role of the TS protein-p53 mRNA interaction, Western immunoblot analysis revealed nearly undetectable levels of p53 protein in TS-overexpressing human colon cancer H630-R10 and rat hepatoma H35(F/F) cell lines compared to the levels in their respective parent H630 and H35 cell lines. Polysome analysis revealed that the p53 mRNA was associated with higher-molecular-weight polysomes in H35 cells compared to H35(F/F) cells. While the level of p53 mRNA expression was identical in parent and TS-overexpressing cell lines, the level of p53 RNA bound to TS in the form of RNP complexes was significantly higher in TS-overexpressing cells. The effect of TS on p53 expression was also investigated with human colon cancer RKO cells by use of a tetracycline-inducible system. Treatment of RKO cells with a tetracycline derivative, doxycycline, resulted in 15-fold-induced expression of TS protein and nearly complete suppression of p53 protein expression. However, p53 mRNA levels were identical in transfected RKO cells in the absence and presence of doxycycline. Taken together, these findings suggest that TS regulates the expression of p53 at the translational level. This study identifies a novel pathway for regulating p53 gene expression and expands current understanding of the potential role of TS as a regulator of cellular gene expression.

Desensitization and sensitization of cells to fluoropyrimidines with different antisenses directed against thymidylate synthase messenger RNA

Previous studies have shown that the cytotoxicity of fluoropyrimidines is mediated, in large part, by inhibition of the enzyme thymidylate synthase (TS). The aim of this study was to determine whether the chemosensitivity of human cancer cells to fluoropyrimidines could be increased by decreasing TS expression with antisense oligodeoxyribonucleotides (ODNs). ODNs (18-mers) targeted at the AUG translational initiation site of TS mRNA inhibited translation in a sequence- and dose-dependent manner in a rabbit reticulocyte lysate in vitro translation system. Treatment of human colon cancer HT-29 cells with antisense ODNs decreased TS catalytic activity in the cells in a dose-dependent manner over a short period, but the longer-term effect of the TS antisense ODN treatment was actually to increase the amount of TS in the cells and to decrease their sensitivity to 5-fluoro-2'-deoxyuridine (FdUrd). However, when human nasopharyngeal cancer KB31 cells were transfected with a plasmid (pHaMAGRP) construct containing the TS antisense fragment (+ 1 to + 422) under the control of a glucose-regulated promoter, the expression of both TS protein and TS catalytic activity was decreased by nearly 30% (P = 0.014), and sensitivity of these cells to FdUrd was enhanced by approximately 8-fold (P = 0.021). No changes in the levels of expression of TS protein or FdUrd-associated cytotoxicity were observed in control, vector-transfected cells. No change was observed in the sensitivity of transfected cells toward either cisplatin or Adriamycin. These results show that the level of expression of TS in human malignant cells can be down-regulated with antisense TS RNA, and their sensitivity to fluoropyrimidines can, thereby, be increased.

[Diagnosis and treatment of thoracic outlet syndrome]

OBJECTIVE

Thoracic outlet syndrome (TOS) is clinically common, but liable to be misdiagnosed. We would like to emphasize the recognition of TOS, and through thorough examination for a complete relief from indicated operation.

METHODS

13 cases receiving surgical operations in PUMC hospital from 1982 to 1996 are reported and discussed the cause of misdiagnosis, investigate the various kinds of abnormalities and compare the result of operation.

RESULTS

92% of the patients had experence of being misdiagnosed for other diseases, the history may be as long as 10 years. In the operations we found 8 kinds of anatomic abnormalities that cause the symptoms and complete relief is satisfactory.

CONCLUSIONS

We have to emphasize the recognition of TOS. The thorough physical examination is important to diagnosis. Patients with typical and apparent symptoms need an operation to relieve the thoracic outlet through the transaxillary approach.

Antioxidant action via p53-mediated apoptosis

The biological effects of antioxidants are often considered in terms of their effects on oxygen or lipid radicals. However, antioxidants can also exert their effects through altering the cellular redox potential. Herein, we report that sulfur-containing antioxidants such as N-acetylcysteine and dimercaptopropanol induced apoptosis in several transformed cell lines and transformed primary cultures but not in normal cells. In contrast, chain-breaking antioxidants such as vitamin E lacked this activity. An increased glutathione level was not required for apoptosis; however, all apoptosis-inducing antioxidants elevated the total cellular thiol levels. Antioxidant-induced apoptosis required the p53 tumor suppressor gene. N-Acetylcysteine elevated p53 expression posttranscriptionally by increasing the rate of p53 mRNA translation rather than by altering the protein stability. The p53 induction occurred in normal cells. These observations indicate a redox sensor for p53 induction in vivo, with additional transformation-specific information being required for apoptosis. Manipulating p53-dependent apoptosis with nontoxic antioxidants may have a direct clinical application.

Forespore expression and processing of the SigE transcription factor in wild-type and mutant Bacillus subtilis

SigmaE is a mother cell-specific transcription factor of sporulating Bacillus subtilis that is derived from an inactive precursor protein (pro-sigmaE). To examine the process that prevents sigmaE activity from developing in the forespore, we fused the sigmaE structural gene (sigE) to forespore-specific promoters (PdacF and PspoIIIG), placed these fusions at sites on the B. subtilis chromosome which translocate into the forespore either early or late, and used Western blot analysis to monitor SigE accumulation and pro-sigmaE processing. sigE alleles, placed at sites which entered the forespore early, were found to generate more protein product than the same fusion placed at a late entering site. SigE accumulation and processing in the forespore were enhanced by null mutations in spoIIIE, a gene whose product is essential for translocation of the distal portion of the B. subtilis chromosome into the forespore. In other experiments, a chimera of pro-sigmaE and green fluorescence protein, previously shown to be unprocessed if it is synthesized within the forespore, was found to be processed in this compartment if coexpressed with the gene for the pro-sigmaE-processing enzyme, SpoIIGA. The need for spoIIGA coexpression is obviated in the absence of SpoIIIE. We interpret these results as evidence that selective degradation of both SigE and SpoIIGA prevent mature sigmaE from accumulating in the forespore compartment of wild-type B. subtilis. Presumably, a gene(s) located at a site that is distal to the origin of chromosome transfer is responsible for this phenomenon when it is translocated and expressed in the forespore.

[Effect of acupuncture and Chinese medicine treatment on brain dopamine level of MPTP-lesioned C57BL mice]

C57BL mice were treated with MPTP and the effect of acupuncture and Chinese medicine treatment on the MPTP lesioned C57BL mice was investigated. The result showed that MPTP significantly decreased caudate nucleus (CN) DA and DOPAC levels and midbrain DA levels. The ratio of DOPAC/ DA increased in CN. After treatment, CN and midbrain DA levels increased in acupuncture, Chinese medicine, acupuncture combined with Chinese medicine and LD treated groups, DOPAC/DA ratio of acupuncture, Chinese medicine and acupuncture combined with Chinese medicine treated groups closed to that of control. DOPAC/DA ratio of LD treated groups closed to that of only MPTP treated group. The result showes that acupuncture, Chinese medicine and LD therapy can increase the decreased DA levels in MPTP mice, and DOPAC/DA ratio in CN of acupuncture, Chinese medicine treated groups closed to that of control, suggesting that acupuncture and Chinese medicine therapy may have protection effect on neuron that different from the replacement therapy of LD.

Bacillus subtilis Pro-sigmaE fusion protein localizes to the forespore septum and fails to be processed when synthesized in the forespore

Endospore formation in Bacillus subtilis begins with an asymmetric cell division that partitions the bacterium into mother cell and forespore compartments. Mother cell-specific gene expression is initiated by sigmaE, a transcription factor that is active only in the mother cell but which existed as an inactive precursor (pro-sigmaE) in the predivisional cell. Activation of pro-sigmaE involves the removal of 27 amino acids from its amino terminus. A chimera of pro-sigmaE and the green fluorescent protein (GFP) was expressed from either the normal sigE promoter (P(spoIIG)), which places pro-sigmaE::GFP in both mother cell and forespore compartments, or the forespore-specific promoter (P(dacF)), which produces pro-sigmaE::GFP only in the forespore compartment. The pro-sigmaE::GFP expressed from P(spoIIG), but not P(dacF), was converted to a lower-molecular-weight form by a mechanism dependent on gene products (SpoIIGA and sigmaF) that are essential for normal pro-sigmaE processing. This finding is consistent with the pro-sigmaE processing reaction occurring only in the mother cell compartment. In processing-deficient cells, pro-sigmaE::GFP was found to accumulate at the septal membrane, a location where its processing apparatus would be susceptible to triggering from the adjoining forespore.

[Clonning and sequencing of partial gene of hepatitis G virus (HGV) from Nanjing of China]

Partial gene of hepatitis G virus (HGV) was cloned and sequenced from the serum of a patient with post-transfusion hepatitis C in Nanjing of China by reverse transcription-polymerase chain reaction (RT-PCR). The sequence showed 89.09%, 92.12%, 87.27%, 93.94% nucleotide identity over the corresponding region of HGU44402, HGU45966, HGU36380 in America and HGV isolate in Hebei Province of China respectively. Forty patients with post-transfusion hepatitis C and thirty patients with hepatitis non A-E were detected for HGV RNA by RT-PCR, the HGV RNA positive rate were 10.00% and 6.67% respectively.

Cyanine dyes with high absorption cross section as donor chromophores in energy transfer primers

Energy transfer (ET) fluorescent primers are significantly superior to single dye-labeled primers for DNA sequencing and multiplex genetic analyses (Ju, J., Glazer, A. N., and Mathies, R. A. (1996) Nature Med. 2, 246-249). We describe here ET primers in which a donor chromophore with a large absorption cross section but a low fluorescence quantum yield is exploited to increase the Stokes-shifted fluorescence emission of acceptor dyes. The new ET primers have 3-(epsilon-carboxy-pentyl)-3'ethyl-5,5'-dimethyloxacarbocyanine (CYA; epsilon M488nm 142,000 M-1 cm-1) at the 5' -end as a common energy donor, and fluorescein or rhodamine derivatives (FAM, R6G, TAMRA, and ROX), attached to a modified thymidine 10 bases away within the primer sequence, as acceptors. With 488-nm excitation, the fluorescence emission intensity of these four ET primers is 1.4- to 24-fold stronger than that of the corresponding primers labeled only with the single acceptor dye. When compared with the corresponding ET primers with a fluorescein derivative (FAM; epsilon M488nm 60,000 M-1 cm-1) as donor, the fluorescence emissions of primers with CYA as donor and FAM, R6G, TAMRA, and ROX as acceptors are respectively 0.8-, 1.0-, 1.7-, and 1.7-fold as intense. The low fluorescence quantum yield of the CYA donor resulted in distinct fluorescence signals for the DNA-sequencing fragments with much lower crosstalk between the four detection channels than that seen with ET primers based on a FAM donor. With single-stranded M13mp18 DNA as the template, the CYA ET primers provided DNA sequences on a four-color capilary sequencer with 100% accuracy in the first 500 bases.

DNA sequencing using a four-color confocal fluorescence capillary array scanner

The design, construction and operation of a four-color capillary array electrophoresis scanner are presented. The use of sensitive energy transfer primers facilitates four-color detection of the DNA sequencing fragments following excitation at a single laser wavelength (488 nm). This scanner collects fluorescence data from up to 25 capillaries in parallel. The resulting four-color image files are automatically reduced to four-color line plots, and a base-calling program (Sax) is used to call the sequence. The performance of this system for DNA sequencing is demonstrated by examining twelve different motifs of the hypervariable region I of human mitochondrial (mt) DNA obtained from a Sierra Leone population.

High-resolution capillary array electrophoretic sizing of multiplexed short tandem repeat loci using energy-transfer fluorescent primers

Short tandem repeat regions (STRs) from the polymorphic loci VWFA, THO1, TPO and CSF were amplified by the multiplex polymerase chain reaction (PCR) and analyzed by capillary array electrophoresis with fluorescence detection of energy transfer (ET) labels. The fluorescent ET primers are labeled with one fluorescein at the 5' end and a second fluorescein at the position of the 7th or 9th (modified) base to produce fragments that fluoresce in the green (lambda max = 525 nm). M13 A-track sequencing fragments, used as an internal sizing standard, were generated with a universal primer that has a donor fluorescein at the 5' end and a rhodamine acceptor at the position of the 11th (modified) base to produce fragments fluorescing in the red (> 590 nm). The labeled DNA fragments were excited at 488 nm, and the fluorescence was detected with a two-color confocal fluorescence scanner. Separations were performed on arrays of hollow fused silica capillaries filled with denaturing and replaceable hydroxyethyl cellulose sieving matrices. Separations were complete in less than 50 min, and single base resolution as well as reproducible STR sizing was achieved. The relative standard deviation in sizing was below 0.6%. This work establishes the feasibility of high-resolution, high-speed and high-throughput STR typing of single-stranded DNA fragments using capillary array electrophoresis.

Energy transfer primers with 5- or 6-carboxyrhodamine-6G as acceptor chromophores

Energy-transfer (ET) fluorescent primers for DNA sequencing and multiplex genetic analysis (Ju, J., Ruan, C., Fuller, C. W., Glazer, A. N., and Mathies, R. A. (1995) Proc. Natl. Acad. Sci. USA 92, 4347-4351) are named according to the convention D-N-A, where D is the donor, N is the number of bases between the donor and the acceptor, and A is the acceptor. Thus, a primer that carries 6-carboxyfluorescein (FAM) at the 5'-end and 6-carboxy-4', 5'-dichloro-2',7'-dimethoxyfluorescein (JOE) attached to a modified thymidine 10 bases away is designated F10J. We describe here new ET primers, with 5- or 6-carboxyrhodamine-6G (G5 or G6) as acceptors (with FAM as the donor) in place of JOE, with improved match in the electrophoretic mobilities of the DNA fragments extended from the ET dye-labeled primers, and less overlap in the fluorescence emission of the various labeled DNA fragments. This reduced spectral overlap is most likely due to the narrower emission from G5 or G6 in F10G compared to that from JOE in F10J. With single-stranded M13mp18 DNA as the template, a typical run with F10G6 and three other ET primers on a capillary sequencer provided DNA sequences with 99% accuracy in the first 620 bases.

Cassette labeling for facile construction of energy transfer fluorescent primers

DNA primer sets, labeled with two fluorescent dyes to exploit fluorescence energy transfer (ET), can be efficiently excited with a single laser line and emit strong fluorescence at distinctive wavelengths. Such ET primers are superior to single fluorophore-labeled primers for DNA sequencing and other multiple color-based analyses [J. Ju, C. Ruan, C. W. Fuller, A. N. Glazer and R. A. Mathies (1995) Proc. Natl. Acad. Sci. USA 92, 4347-4351]. We describe here a novel method of constructing fluorescent primers using a universal ET cassette that can be incorporated by conventional synthesis at the 5'-end of an oligonucleotide primer of any sequence. In this cassette, the donor and acceptor fluorophores are separated by a polymer spacer (S6) formed by six 1',2'-dideoxyribose phosphate monomers (S). The donor is attached to the 5' side of the ribose spacer and the acceptor to a modified thymidine attached to the 3' end of the ribose spacer in the ET cassette. The resulting primers, labeled with 6-carboxy-fluorescein as the donor and other fluorescein and rhodamine dyes as acceptors, display well-separated acceptor emission spectra with 2-12-fold enhanced fluorescence intensity relative to that of the corresponding single dye-labeled primers. With single- stranded M13mp18DNA as the template, a typical run with these ET primers on a capillary sequencer provides DNA sequences with 99% accuracy in the first 550 bases using the same amount of DNA template as that typically required using a four-color slab gel automated sequencer.

Monoclonal antibody assay for measuring bone-specific alkaline phosphatase activity in serum

Alkaline phosphatase (ALP) is present in human serum in the form of several isoenzymes. The two major circulating ALP isoenzymes, bone and liver, are difficult to distinguish because they are the products of a single gene and differ only by posttranslational glycosylation. Quantitative measurement of bone ALP (BAP) activity in serum can provide an index for the rate of bone formation. Furthermore, increased BAP activity in serum is indicative of bone disorders. We describe a method in which serum samples are added to a microtiter plate coated with monoclonal anti-BAP antibody and incubated 3 h at room temperature. After the unbound materials are washed off, the bound BAP activity is measured by adding p-nitrophenyl phosphate substrate. The assay demonstrated no cross-reactivity to intestinal or placental ALP and only 3-8% cross-reactivity to liver ALP. The intraassay (n = 21) CVs were 3.9-5.9%, and interassay (n = 8) CVs were 4.4-7.0%. Comparisons of the assay (y) with an IRMA (x) and a wheat germ agglutinin precipitation method (x') gave regression equations of y = 1.32x-6.4, r = 0.99, and y = 1.41x' + 4.8, r = 0.99. The assay detected increased BAP in sera from patients with osteoporosis, Paget disease, osteomalacia, or primary hyperparathyroidism.

Monoclonal antibody assay for measuring bone-specific alkaline phosphatase activity in serum

Alkaline phosphatase (ALP) is present in human serum in the form of several isoenzymes. The two major circulating ALP isoenzymes, bone and liver, are difficult to distinguish because they are the products of a single gene and differ only by posttranslational glycosylation. Quantitative measurement of bone ALP (BAP) activity in serum can provide an index for the rate of bone formation. Furthermore, increased BAP activity in serum is indicative of bone disorders. We describe a method in which serum samples are added to a microtiter plate coated with monoclonal anti-BAP antibody and incubated 3 h at room temperature. After the unbound materials are washed off, the bound BAP activity is measured by adding p-nitrophenyl phosphate substrate. The assay demonstrated no cross-reactivity to intestinal or placental ALP and only 3-8% cross-reactivity to liver ALP. The intraassay (n = 21) CVs were 3.9-5.9%, and interassay (n = 8) CVs were 4.4-7.0%. Comparisons of the assay (y) with an IRMA (x) and a wheat germ agglutinin precipitation method (x') gave regression equations of y = 1.32x-6.4, r = 0.99, and y = 1.41x' + 4.8, r = 0.99. The assay detected increased BAP in sera from patients with osteoporosis, Paget disease, osteomalacia, or primary hyperparathyroidism.

Design and synthesis of fluorescence energy transfer dye-labeled primers and their application for DNA sequencing and analysis

We have designed and synthesized fluorescent oligonucleotide primers having improved fluorescence and electrophoretic properties by exploiting the concept of resonance fluorescence energy transfer (ET). These primers carry a fluorescein derivative at the 5' end as a common fluorescence donor and other fluorescein and rhodamine derivatives attached to a modified thymidine within the primer sequence as acceptors. These primers all have strong absorption at a common excitation wavelength (448 nm) and fluorescence emission maxima of 525, 555, and 605 nm. The fluorescence emission intensity of the ET primers increases as the spacing between the donor and acceptors is increased, and of the spacings studied the strongest fluorescence was observed when the number of nucleotides between the donor and acceptors is 10. The electrophoretic mobilities of the primers were also found to be a function of the spacing between the donor and the acceptors, and mobilities of the single base extension DNA fragments generated with primers (F10F, F10J, F10T, and F10R) is 2- to 14-fold greater than that of the corresponding primers labeled with only one dye. The increased fluorescence intensity of the ET primers and the substantially similar mobilities of the DNA fragments generated with the four ET primers allow four-color DNA sequencing on a capillary electrophoresis DNA sequencer using a single laser line at 488 nm for excitation and without applying mobility shift adjustments. With single-stranded M13mp18 DNA as the template, a typical run with the ET primers on a commercial sequencer provided DNA sequences with 99-100% accuracy in the first 500 bases using 8-fold less DNA template than that typically required using T7 DNA polymerase.