Immune Profile of Inflammatory Breast Cancer Patients

Background: Inflammatory breast cancer (IBC) is characterized by an acute inflammation of the skin of the affected breast due to blockage of the dermal lymphatics by tumor emboli. Cytokines and chemokines affect the migration of tumor cells and immune cell function that regulates the pathogenesis of IBC. Preliminary data suggest that sera of IBC patients contain several inflammatory cytokines and chemokines capable of regulating innate and adaptive cellular immune responses. Since there is a paucity of data on the characteristics and function of immune cells of IBC patients, we determined the immunophenotype and cytokine production by T cells and dendritic cells.Methods: From October 2008 through May 2009, peripheral blood (PB) from 34 IBC patients (18 non-metastatic and 16 metastatic), 18 non-IBC patients and 24 healthy donors (HD) were analyzed to determine the immunophenotype of T-cell subsets, activated and regulatory T-cells, B-cells, natural killer cell subsets (NKC), and dendritic cell (DC) subsets. Additionally, we assessed the ability of T-cells and DCs to synthesize cytokines following activation through the T-cell receptor (TCR) and toll-like receptors (TLR), respectively. The Kruskal-Wallis and Mann-Whitney U tests determined the differences between IBC patients, non-IBC patients, and HD.Results: IBC and non-IBC patients were well-matched in terms of ER, PR, Her2, high-grade tumor, tumor size, and menopause status. Both IBC and non-IBC patients had significantly fewer lymphocytes, total T-cells (CD3+), T-helper (CD4+), T-cytotoxic/suppressor (CD8+), and B (CD19+) than HD (all p < 0.01). Non-IBC patients had a significantly lower CD4/CD8 ratio than HD (p = 0.016) while IBC patients had significantly fewer T-regulatory (CD4+CD25hiCD127-) cells than HD (p = 0.02) and non-IBC patients (p < 0.05). With respect to innate immunity markers, IBC patients also had significantly lower percentages of ADCC/NK (CD16+CD56+, p = 0.034) and non-exhaustive NK (CD56+CD57+, p = 0.02) than HD and a significantly higher percentage of non-ADCC/NK cells than non-IBC patients (p = 0.03). Non-IBC patients and HD had similar innate immunity markers. Even though all groups had similar percentages of myeloid (mDC) and plasmacytoid (pDC) dendritic cells, mDC of IBC patients displayed a higher level of constitutive activation than non-IBC with increased expression of CD40 and CD80, and decreased CCR5 expression. IBC patients had more mDC that constitutively produced TNF-a (p 0.041) and IL-10 (p = 0.029) than HD, and more mDC than non-IBC patients that produced IL-10 (p = 0.028).Conclusion: The immune profile of patients with breast cancer suggests multiple abnormalities involving T-, B-, NK- and dendritic cells. Furthermore, IBC patients exhibited constitutive immune activation as measured by increased expression of co-stimulatory receptors (CD80, CD40) and constitutive production of TNF-a and IL-10 by mDC as well as fewer T-regulatory cells. Taken together, these preliminary data suggest that IBC patients are more likely than non-IBC patients to have a dysregulated immune function. Additional studies on T-cell activation and function are warranted to better understand factors associated with host defense mechanisms of IBC patients and possible therapeutic strategies to restore immune function.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4129.

Characterization of Metastatic Breast Cancer Patients with Non-Detectable Circulating Tumor Cells

Background: Circulating tumor cells (CTC) are independent predictor of progression free and overall survival in metastatic breast cancer patients, with superior prognosis for patients with CTC <5 per 7.5mL of peripheral blood. However, 30-50% of patients have non-detectable CTC. The aim of this study was to assess the prognostic factors in MBC patients with non-detectable CTC.Methods: This retrospective study included 271 MBC patients evaluated between January 2004 and December 2007. Median age of patients was 56 years (range: 23-82 years). CTCs were enumerated before patients started a new line of treatment using the CellSearchTM. Overall survival (OS) was calculated from the date of CTC measurement, estimated by the Kaplan-Meier product limit method, and compared between groups with the log-rank test.Results: Median CTC count was 2 (range: 0-1780) per 7.5 mL. CTCs were not detected in 99 (36.5%) patients, while 112 (41.3%) patients had CTC ≥ 5. Median OS for patients with 0 CTC; 1-4 CTC and ≥ 5 CTC was 29.3; 26.4; and 19.4 months (p = 0.04), respectively. Patients with brain metastasis have the highest probability of non-detectable CTC (71.4% vs. 33.6%; p = 0.001), while patients with bone metastasis are more likely to have CTC ≥ 1 (48.2% vs. 31.8%; p = 0.01). There was no association between other tumor characteristics (ER, PR, HER2, number and localization of tumor metastasis) and non-detectable CTC status. Patients with CTC = 0 have non-significantly better OS compared to patients with CTC ≥ 1 (29.3 vs. 23.3 months; p = 0.09) and have superior survival in all but one analyzed subgroups; only inflammatory breast cancer (IBC) patients with CTC = 0 have inferior OS compared with patients with CTC ≥ 1 (26 vs. 37 months; p = 0.67). In a subgroup of patients with non-detectable CTC, triple negative MBC has the poorest survival (median OS = 18.8 months), while hormone receptor positive MBC, without visceral metastases and non-inflammatory breast cancer has the best survival (median OS = 36.9 months). In multivariate analysis, hormone receptor status and line of therapy were only independent prognostic factors for OS in patients with non-detectable CTC (Table 1).Conclusion: Patients with non-detectable CTC before start of new line of therapy comprise a heterogeneous group of patients with substantially different prognosis. Triple negative and IBC patients represent poor prognosis subgroups. These data suggest heterogeneity of microscopic disease in advanced cancer and indicate the need to investigate combining additional detection technologies.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3006.

Brain Metastases in Women with Inflammatory Breast Cancer (IBC): Incidence, Treatment and Outcome

Background: Brain metastases are an uncommon metastatic recurrence site in breast cancer with a median incidence of approximately 6% in unselected populations. Inflammatory breast cancer (IBC) is an aggressive disease associated with dismal outcome. The purpose of this study was to determine the incidence of and survival following brain metastases among women with IBC.Material and Methods: Two hundred and six women with newly diagnosed stage III or IV IBC diagnosed between the period of between 2003 and 2008 were identified in a prospectively maintained IBC database at the MD Anderson Cancer Center. Cumulative incidence of brain metastases was computed. Cox proportional hazards models were fitted to explore factors that predict for the development of brain metastases. Survival was computed using the Kaplan-Meier product limit method.Results: Median follow-up was 20 months. Eighty three (40.3%) women had de-novo stage IV disease and 123 (59.7%) had stage III disease at diagnosis. Thirty-three (16%) patients developed brain metastases with a cumulative incidence at 1 and 3 years of 2.7% and 22% respectively. Eleven (5.3%) patients developed brain metastases as the first site of recurrence with cumulative incidence at 1 and 3 years of 1.6% and 6.7% respectively. In the multivariable model, no specific factor was observed to be significantly associated with time to brain metastases, including HER-2 status. Median overall survival for the whole cohort was not reached. 3-year overall survival for the whole cohort was 78% (95% CI 69%-86%). Median survival following a diagnosis of brain metastases for all women who developed brain metastases or those who developed brain metastases as the first site of recurrence was 6 months.Conclusion: In this single-institutional study, women with IBC demonstrated a high early incidence of brain metastases associated with poor survival. As such IBC may be an ideal cohort to target screening procedures for brain metastases and/or enrollment of these women in clinical trials evaluating additional adjuvant preventive strategies.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2102.

Role of the prostaglandin receptor EP3 in regulating vasculogenic mimicry of inflammatory breast cancer

Abstract #2127

Background: Inflammatory breast cancer is an aggressively angiogenic, metastatic and lethal variant of breast cancer. One of the characteristics of aggressive tumors types such as IBC is the ability of tumor cells to undergo vasculogenic mimicry (VM), which is the formation of organized capillary like structures in vitro and in vivo much like endothelial cells, providing a conduit for oxygen and nutrients to reach hypoxic and nutrient deprived tumor cells that have outgrown their adjacent vascular supply. Using genomic and proteomic profiling as well as Western blotting, immunohistochemistry, invasion assays using the modified Boyden chamber assay as well as digital imaging, we evaluated the signal transduction pathways involved in regulating proliferation, invasion, and VM by IBC tumor cells.
 Results: We found that cyclooxygenase-2 (Cox-2), which produces the bioactive lipid, prostaglandin E2 (PGE2) is one gene that is highly expressed IBC tumor cell lines, SUM149 and SUM190. The biological activity of PGE2 occurs via binding of PGE2 to one of 4 members of a G protein coupled receptor family, designated as the EP receptors, EP1, EP2, EP3 and EP4. Western blot analysis and immunochemistry revealed that EP3 receptor protein is produced at very high levels by both IBC tumor cell lines to a significantly (p<0.05) greater extent than either human MCF-7 or MDA-MB-231 non-IBC breast tumor cells. Since EP3 is known to be an inhibitory prostanoid receptor, we evaluated the dose dependent effects of the EP3 agonist, sulprostone, on proliferation, invasion, and VM. Sulprostone [0.1, 1, 10 and 100 μm] inhibited proliferation of SUM149 and SUM190 IBC cells in a dose and time dependent manner to a significantly greater extent (p<0.01) than MCF-7 or MDA-MB-231 breast tumor cells. Sulprostone inhibited invasion of SUM149 IBC tumor cells, with no effect on invasion of a basement membrane by the MDA-MB-231 human non-IBC breast tumor cells. SUM149 IBC tumor cells undergo VM, which was completely inhibited by 10 μM sulprostone at 24 hrs, as visualized by Periodic Acid Schiff (PAS) staining and digital imaging. The ability of sulprostone to completely inhibit VM occurred in conjunction with inhibition of production of laminin 5-γ2 fragments and matrix metalloproteinase-2 (MMP-2) activity. Studies are currently underway to determine the in vivo effect of sulprostone on IBC tumor growth, VM, and metastasis of SUM149 IBC xenografts.
 Discussion: These results suggest that targeting EP3 may provide a selective advantage for abrogating not only proliferation, and invasion but also vasculogenic mimicry that is a key component of the rapid angiogenic program observed in IBC.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2127.

Using gene expression profiling to identify a prognostic molecular spectrum in gliomas

Histopathological classification of gliomas is often clinically inadequate due to the diversity of tumors that fall within the same class. The goal of the present study was to identify prognostic molecular features in diffusely infiltrating gliomas using gene expression profiling. We selected 3456 genes expressed in gliomas, including 3012 genes found in a gliomal expressed sequence tag collection. The expression levels of these genes in 152 gliomas (100 glioblastomas, 21 anaplastic astrocytomas, 19 diffuse astrocytomas, and 12 anaplastic oligodendrogliomas) were measured using adapter-tagged competitive polymerase chain reaction, a high-throughput reverse transcription-polymerase chain reaction technique. We applied unsupervised and supervised principal component analyses to elucidate the prognostic molecular features of the gliomas. The gene expression data matrix was significantly correlated with the histological grades, oligo-astro histology, and prognosis. Using 110 gliomas, we constructed a prediction model based on the expression profile of 58 genes, resulting in a scheme that reliably classified the glioblastomas into two distinct prognostic subgroups. The model was then tested with another 42 tissues. Multivariate Cox analysis of the glioblastoma patients using other clinical prognostic factors, including age and the extent of surgical resection, indicated that the gene expression profile was a strong and independent prognostic parameter. The gene expression profiling identified clinically informative prognostic molecular features in astrocytic and oligodendroglial tumors that were more reliable than the traditional histological classification scheme.

A negative regulator of delayed prostaglandin D2 production in mouse mast cells

We have previously shown that maturation of mouse bone marrow-derived mast cells (BMMCs) into connective tissue mast cells (CTMCs) upon coculture with fibroblasts in the presence of stem cell factor (kit ligand) is accompanied by marked induction of a panel of genes, one of which was identified as NLRP3. Here we report that NLRP3 acts as a novel negative regulator of delayed prostaglandin (PG) D(2) production in BMMCs. We found that, apart from its cell maturation-associated induction, NLRP3 expression was markedly induced in BMMCs several hours after FcepsilonRI crosslinking or cytokine stimulation. Ectopic expression of NLRP3 in BMMCs resulted in marked attenuation of cyclooxygenase (COX)-2-dependent delayed PGD(2) generation, whereas it had no effects on other effector functions, including degranulation, COX-1-dependent immediate PGD(2) generation and cytokine/chemokine expression. The suppression of delayed PGD(2) generation by NLRP3 was preceded by a transient decrease of NF-kappaB activation and a marked reduction in the expression of COX-2, but not that of cytosolic phospholipase A(2) alpha (cPLA(2)alpha), COX-1 and hematopoietic PGD(2) synthase. Moreover, in CTMC-like differentiated cells in which endogenous NLRP3 expression was induced, cytokine-stimulated induction of COX-2 and attendant delayed PGD(2) generation were markedly reduced. Our results suggest that, in mouse mast cells, NLRP3 counter-regulates COX-2-dependent sustained production of PGD(2), a prostanoid that exhibits both pro- and anti-allergic effects, thereby potentially influencing the duration of allergic and other mast cell-associated inflammatory diseases.

The lack of the C-terminal domain of adipose triglyceride lipase causes neutral lipid storage disease through impaired interactions with lipid droplets

CONTEXT

The molecular mechanisms by which triglycerides in lipid droplets (LDs) are synthesized, stored, and degraded need to be elucidated.

OBJECTIVE

The objectives were to report siblings with neutral lipid storage disease with myopathy (NLSDM) with a novel mutation of adipose triglyceride lipase (ATGL) and determine whether the C-terminal part of ATGL containing the hydrophobic region plays a role in the interaction with LDs.

DESIGN AND PATIENTS

Skin fibroblasts and peripheral blood leukocytes were obtained from NLSDM patients. In vitro experiments were performed with fibroblasts and COS7 cells.

MAIN OUTCOME MEASURES

Transfection studies were used to assess the effects of various recombinant ATGL proteins on lipase activities and lipid contents. Fluorescence microscopy were used for determination of intracellular distribution of ATGL proteins.

RESULTS

The direct sequence of ATGL cDNA reveals that a patient is a homozygote for the 4-bp deletion, leading to a premature stop codon and causes the lack of the C terminus of the protein including the hydrophobic domain. Overexpressed control ATGL in NLSDM fibroblasts was found around the rims of LDs and caused significantly reduced cellular lipid accumulation. In contrast, NLSDM ATGL was homogeneously located in the cytoplasm despite the presence of LDs and had almost no effect on LD degradation despite its similar lipase activity. A series of C-terminal truncated ATGLs without the intact hydrophobic domain failed to localize around and degrade LDs.

CONCLUSIONS

These findings indicate that the domain including the hydrophobic region of ATGL was essential for association with LDs.

Concurrent daily cisplatin and extended-field radiation therapy for carcinoma of the cervix

The aim of this study was to assess acute toxicities of concurrent low-dose daily cisplatin and extended-field radiation therapy (EFRT) for carcinoma of the uterine cervix. Fifteen women with cervical cancer who were treated with concurrent daily low-dose cisplatin and EFRT were analyzed. Daily cisplatin dose was fixed to 8 mg/m(2), which was determined in the preceding phase I study using pelvic radiotherapy. Twelve patients underwent either combined external beam radiation therapy and intracavitary brachytherapy or external beam radiation therapy alone. Three other patients were treated with adjuvant chemoradiotherapy after surgery. A total dose of EFRT ranged from 40 to 45 Gy, with an additional boost to the gross tumor volume up to 50.4-55 Gy. A median total dose of cisplatin during entire radiation therapy course was 224 mg/m(2) (range, 200-240 mg/m(2)). In 14 of 15 patients (93%), daily cisplatin could be delivered continuously as planned without any modification. Administration of cisplatin had to be interrupted in only one patient for only 3 days. Fourteen patients developed grade 2 or worse leukopenia including five after treatment, grade 2 in four, grade 3 in eight, and grade 4 in two. Grade 3 thrombocytopenia was observed in three patients. Grade 2 or worse anemia was observed in 12. Three patients had grade 3 nonhematologic toxicities, diarrhea in two, and nausea/vomiting in one. Although moderate to severe hematologic toxicities are common, this study suggests that concurrent low-dose daily cisplatin and EFRT are feasible. A cumulative cisplatin dose of greater than 200 mg/m(2) during radiation therapy could be achieved by using daily cisplatin dose of 8 mg/m(2).

Control of the Interchain π−π Interaction and Electron Density Distribution at the Surface of Conjugated Poly(3-hexylthiophene) Thin Films

Interchain interaction, i.e., pi-pi stacking, can benefit the carrier transport in conjugated regio-regular poly(3-hexylthiophene) (P3HT) thin films. However, the existence of the insulating side hexyl chains in the surface region may be detrimental to the charge transfer between the polymer backbone and overlayer molecules. The control of the molecular orientation in the surface region is expected to alter the distribution of the pi electron density at the surface to solve such problems, which can be achieved by controlling the solvent removal rate during solidification. The evidence that the pi-electron density distribution at the outermost surface can be controlled is demonstrated by the investigation using the powerful combination of near edge X-ray absorption fine structure spectroscopy, ultraviolet photoelectron spectroscopy, and the most surface-sensitive technique: Penning ionization electron spectroscopy. From the spectroscopic studies, it can be deduced that the slower removal rate of the solvent makes the polymer chains even at the surface have sufficient time to adopt a more nearly equilibrium structure with edge-on conformation. Thus, the side hexyl chains extend outside the surface, which buries the pi-electron density contributed from the polymer backbone. Contrarily, the quench of obtaining a thermo-equilibrium structure in the surface region due to the faster removal of the solvent residual can lead to the surface chain conformation without persisting to the strong bulk orientation preference. Therefore, the face-on conformation of the polymer chain at the surface of thin films coated with high spin coating speed facilitate the electron density of the polymer backbone exposed outside the surface. Finally, thickness dependence of the surface electronic structure of P3HT thin films is also discussed.

Concurrent chemoradiation for patients with squamous cell carcinoma of the cervical esophagus

Little is known concerning the role of concurrent chemoradiation (CCRT) in the management of carcinoma of the cervical esophagus. We retrospectively evaluated our treatment approach for patients with cervical esophageal cancer with special emphasis on CCRT with or without surgery. Medical records of 21 consecutive patients with cervical esophageal carcinoma treated mainly with CCRT (1997-2004) were reviewed, and factors that influenced patient survival were analyzed retrospectively. Nineteen received CCRT with cisplatin/5-fluorouracil and five underwent curative surgery. Two patients who were deemed unfit for CCRT received radiation therapy alone. All had three-dimensional treatment planning (median total dose, 40 Gy with surgery, 64 Gy without surgery). Of the 19 patients who received CCRT, 11 patients including five who underwent curative surgery achieved initial local control. Neither of the two patients who received radiation therapy alone achieved local control. Among 19 patients who underwent CCRT, 9/11 with T1-3 grade tumors achieved initial local control, but only 2/8 patients with T4 tumors (P = 0.011, chi(2) test) achieved initial local control. No patient without initial local control survived > 20 months compared with 2-year and 5-year survival rates of 60% and 40% in those who achieved initial local control (P = 0.038). No patient with T4 tumors survived > 18 months, whereas 2- and 5-year survival rates were 62% and 41%, respectively, in those with T1-3 tumors (P = 0.006). The significant effect of T-classification on survival was maintained when analyzed among 19 patients who received CCRT. CCRT shows promise for cervical esophageal carcinoma. T-classification and initial local control had significant impact on survival.

Prediction of peritoneal metastasis in advanced gastric cancer by gene expression profiling of the primary site

Peritoneal metastasis is the most common cause of tumour progression in advanced gastric cancer. Clinicopathological findings including cytologic examination of peritoneal lavage have been applied to assess the risk of peritoneal metastasis, but are sometimes inadequate for predicting peritoneal metastasis in individuals. Hence, we tried to construct a new prediction system for peritoneal metastasis by using a PCR-based high throughput array with 2304 genes. The prediction system, constructed from the learning set comprised of 30 patients with the most informative 18 genes, classified each case into a 'good signature group' or 'poor signature group'. Then, we confirmed the predictive performance in an additional validation set comprised of 24 patients, and the prediction accuracy for peritoneal metastasis was 75%. Kaplan-Meier analysis with peritoneal metastasis revealed significant difference between these two groups (P=0.0225). By combining our system with conventional clinicopathological factors, we can identify high risk cases for peritoneal metastasis more accurately.

Direct involvement of the small GTPase Rac in activation of the superoxide-producing NADPH oxidase Nox1

Activation of the non-phagocytic superoxide-producing NADPH oxidase Nox1, complexed with p22(phox) at the membrane, requires its regulatory soluble proteins Noxo1 and Noxa1. However, the role of the small GTPase Rac remained to be clarified. Here we show that Rac directly participates in Nox1 activation via interacting with Noxa1. Electropermeabilized HeLa cells, ectopically expressing Nox1, Noxo1, and Noxa1, produce superoxide in a GTP-dependent manner, which is abrogated by expression of a mutant Noxa1(R103E), defective in Rac binding. Superoxide production in Nox1-expressing HeLa and Caco-2 cells is decreased by depletion or sequestration of Rac; on the other hand, it is enhanced by expression of the constitutively active Rac1(Q61L), but not by that of a mutant Rac1 with the A27K substitution, deficient in binding to Noxa1. We also demonstrate that Nox1 activation requires membrane recruitment of Noxa1, which is normally mediated via Noxa1 binding to Noxo1, a protein tethered to the Nox1 partner p22(phox): the Noxa1-Noxo1 and Noxo1-p22(phox) interactions are both essential for Nox1 activity. Rac likely facilitates the membrane localization of Noxa1: although Noxa1(W436R), defective in Noxo1 binding, neither associates with the membrane nor activates Nox1, the effects of the W436R substitution are restored by expression of Rac1(Q61L). The Rac-Noxa1 interaction also serves at a step different from the Noxa1 localization, because the binding-defective Noxa1(R103E), albeit targeted to the membrane, does not support superoxide production by Nox1. Furthermore, a mutant Noxa1 carrying the substitution of Ala for Val-205 in the activation domain, which is expected to undergo a conformational change upon Rac binding, fully localizes to the membrane but fails to activate Nox1.

Activation of the superoxide-producing phagocyte NADPH oxidase requires co-operation between the tandem SH3 domains of p47phox in recognition of a polyproline type II helix and an adjacent alpha-helix of p22phox

Activation of the superoxide-producing phagocyte NADPH oxidase, crucial for host defence, requires an SH3 (Src homology 3)-domain-mediated interaction of the regulatory protein p47phox with p22phox, a subunit of the oxidase catalytic core flavocytochrome b558. Although previous analysis of a crystal structure has demonstrated that the tandem SH3 domains of p47phox sandwich a short PRR (proline-rich region) of p22phox (amino acids 151-160), containing a polyproline II helix, it has remained unknown whether this model is indeed functional in activation of the oxidase. In the present paper we show that the co-operativity between the two SH3 domains of p47phox, as expected from the model, is required for oxidase activation. Deletion of the linker between the p47phox SH3 domains results not only in a defective binding to p22phox but also in a loss of the activity to support superoxide production. The present analysis using alanine-scanning mutagenesis identifies Pro152, Pro156 and Arg158 in the p22phox PRR as residues indispensable for the interaction with p47phox. Pro152 and Pro156 are recognized by the N-terminal SH3 domain, whereas Arg158 contacts with the C-terminal SH3 domain. Amino acid substitution for any of the three residues in the p22phox PRR abrogates the superoxide-producing activity of the oxidase reconstituted in intact cells. The bis-SH3-mediated interaction of p47phox with p22phox thus functions to activate the phagocyte oxidase. Furthermore, we provide evidence that a region C-terminal to the PRR of p22phox (amino acids 161-164), adopting an a-helical conformation, participates in full activation of the phagocyte oxidase by fortifying the association with the p47phox SH3 domains.

Regulation of superoxide-producing NADPH oxidases in nonphagocytic cells

The membrane-integrated protein gp91phox functions as the catalytic center of the superoxide-producing phagocyte NADPH oxidase. Recent studies have identified homologs of gp91phox in nonphagocytic cells, which constitute the NADPH oxidase (Nox) family. Activation of the Nox oxidases leads to production of reactive oxygen species (ROS), thereby participating in a variety of biological events, such as host defense, hormone biosynthesis, and signal transduction. The activity of the Nox enzymes is regulated by various proteins, including the small GTPase Rac; regulatory mechanisms differ dependent on the type of the Nox proteins. For example, an oxidase activator (p47phox or Noxo1) and an oxidase activator (p67phox or Noxa1) are absolutely required for superoxide production by gp91phox and Nox1, but not by Nox3. Rac, albeit probably dispensable to the Nox3 activity, plays an essential role in activation of gp91phox. Thus, functional reconstitution of Nox systems is crucial for the study of Nox regulation. Here we describe a basic method for the reconstitution of Nox systems by expression of oxidase proteins in transfectable cells.

Coupling between cyclooxygenases and terminal prostanoid synthases

Biosynthesis of prostanoids is regulated by three sequential enzymatic steps, namely phospholipase A2, cyclooxygenase (COX), and terminal prostanoid synthase. Recent evidence suggests that lineage-specific terminal prostanoid synthases, including prostaglandin (PG) E2, PGD2, PGF2alpha, PGI2, and thromboxane synthases, show distinct functional coupling with upstream COX isozymes, COX-1 and COX-2. This can account, at least in part, for segregated utilization of the two COX isozymes in distinct phases of PG-biosynthetic responses. In terms of their localization and COX preference, terminal prostanoid synthases are classified into three categories: (i) the perinuclear enzymes that prefer COX-2, (ii) the cytosolic enzyme that prefers COX-1, and (iii) the translocating enzyme that utilizes both COXs depending on the stimulus. Additionally, altered supply of arachidonic acid by phospholipase A2s significantly affects the efficiency of COX-terminal prostanoid synthase coupling. In this review, we summarize our recent understanding of the coupling profiles between the two COXs and various terminal prostanoid synthases.

Purification and characterization of an acid trehalase from Acidobacterium capsulatum

We purified an acid trehalase (EC 3.2.1.28, alpha,alpha'-trehalose glucohydrolase) from an acidophilic bacterium, Acidobacterium capsulatum. The enzyme was homogeneous based on polyacrylamide gel electrophoresis, and was composed of a single polypeptide chain with a molecular mass of 57 kDa. Maximum trehalase activity was observed at pH 2.5. The acid trehalase exhibited an apparent K(m) of 1.0 mM for trehalose at 30 degrees C and pH 3.0. The trehalase was located in the periplasmic space. The activity of the enzyme was activated by 1.0 mM MnCl2 or CoCl2, and inhibited by 1.0 mM PbCl2, HgCl2, NiCl2, p-chloromercuribenzoate, N-ethylmaleimide, monoiodoacetate, or EDTA. The enzyme showed high specificity for trehalose. It was found that an equimolar mixture of alpha-D-glucose and beta-D-glucose was formed on hydrolysis of trehalose by the trehalase.

Hybridization of oligonucleotide by using DNA self-assembled monolayer

The interaction between DNA immobilized on surface and oligonucleotides at the interface is important in detection and diagnostic processes. However, it is difficult to immobilize DNA with maintaining its activity and to realize an efficient hybridization in previous methods. Here, to establish a novel DNA-functionalized surface, the DNA self-assembled monolayer (SAM) was constructed on a gold substrate using thiolated DNA composed of double-stranded (ds) and single-stranded (ss) portion. The DNA SAM was characterized by surface plasmon resonance (SPR), XPS. The hybridization of ss portion of DNA was attempted using the SAM, and in situ monitored by SPR. XPS measurement indicated that the thiolated DNA could form a stable monolayer on a gold substrate through sulfur-gold interaction. SPR measurement implied that the long axis of the DNA standing on the substrate. These results indicated formation of the DNA SAM on the substrate. Hybridization of target DNA containing a complementary sequence for the probe portion was observed by SPR. Moreover, one mismatch of oligonucleotide could be distinguished using the DNA SAM. The SPR result indicates that hybridization of target DNA and probe DNA on the DNA SAM occurs on the DNA SAM.

The NADPH Oxidase Nox3 Constitutively Produces Superoxide in a p22 -dependent Manner

Nox3, a member of the superoxide-producing NADPH oxidase (Nox) family, participates in otoconia formation in mouse inner ears, which is required for perception of balance and gravity. The activity of other Nox enzymes such as gp91(phox)/Nox2 and Nox1 is known to absolutely require both an organizer protein (p47(phox) or Noxo1) andanactivatorprotein (p67(phox) or Noxa1); for the p47(phox)-dependent activation of these oxidases, treatment of cells with stimulants such as phorbol 12-myristate 13-acetate is also indispensable. Here we show that ectopic expression of Nox3 in various types of cells leads to phorbol 12-myristate 13-acetate-independent constitutive production of a substantial amount of superoxide under the conditions where gp91(phox) and Nox1 fail to generate superoxide, i.e. in the absence of the oxidase organizers and activators. Nox3 likely forms a functional complex with p22(phox); Nox3 physically interacts with and stabilizes p22(phox), and the Nox3-dependent superoxide production is totally dependent on p22(phox). The organizers p47(phox) and Noxo1 are capable of enhancing the superoxide production by Nox3 in the absence of the activators, and the enhancement requires the interaction of the organizers with p22(phox), further indicating a link between Nox3 and p22(phox). The p47(phox)-enhanced Nox3 activity is further facilitated by p67(phox) or Noxa1, whereas the activators cancel the Noxo1-induced enhancement. On the other hand, the small GTPase Rac, essential for the gp91(phox) activity, is likely dispensable to the Nox3 system. Thus Nox3 functions together with p22(phox) as an enzyme constitutively producing superoxide, which can be distinctly regulated by combinatorial use of the organizers and activators.

Prediction of recurrence in advanced gastric cancer patients after curative resection by gene expression profiling

The prognosis of patients with advanced gastric cancer remains unfavorable. Even after curative resection, 40% of patients with advanced gastric cancer die of recurrence. Conventional clinicopathlogic findings are sometimes inadequate for predicting recurrence in individuals. Hence, we tried to construct a new diagnostic system, which predicts recurrence in patients with advanced gastric cancer after curative resection based on molecular analysis. Gastric cancer progression is a function of multiple genetic events that may affect the expression of large number of genes. We performed gene expression profiling with 2,304 genes in 60 advanced gastric cancer patients who underwent curative resection using a PCR array technique, a high-throughput quantitative RT-PCR technique. The diagnostic system, which was constructed from the learning set comprised of 40 patients with the most informative 29 genes, classified each case into a good-signature or poor-signature group. Then, we confirmed the predictive performance in an additional test set comprised of 20 patients, and the prediction accuracy for recurrence was 75%. Kaplan-Meier analysis revealed significant difference between the good-signature and the poor-signature group (p = 0.0125). Especially in patients with smaller tumor (< or = 5 cm), less developed LN metastasis (N(0,1)), or earlier stage (stages I and II), the prediction accuracy was high (88.9%, 84.6%, or 81.8%, respectively). Our diagnostic system based on systematic analysis of gene expression profiling can predict the recurrence at clinically meaningful level. By combining our system with conventional clinicopathologic factors, we can improve the prediction of recurrence in patients with advanced gastric cancer who underwent curative surgery.

Stereochemistry of 1,2-dichloroethane adsorbed on Pt(111)

The rotational isomerism of 1,2-dichloroethane (DCE, CH2ClCH2Cl) adsorbed on Pt(111) was studied in the temperature range of 35-100 K using high-resolution electron energy loss spectroscopy and metastable atom electron spectroscopy. In the coverage below monolayer the physisorbed and chemisorbed species coexist at 35 K in the gauche and slightly distorted trans form, respectively. Owing to the direct Pt-Cl interactions, the nonbonding Cl 3p states of the chemisorbed DCE are split off, giving rise to degradation in symmetry from the pure trans form (C2h). The physisorbed gauche conformers are arranged with the C2 axis parallel (or heavily tilted) to the substrate and converted irreversibly to the pseudo-trans form by heating at 70 K. In the multilayer, the trans and gauche conformers exist at 35 K, where the former population is increased with increasing layer thickness. Upon annealing the bilayer at 80 K, the irreversible conversion takes place to yield a higher population of the gauche conformer in the topmost layer. The conformational stabilities and mutual changes of DCE adsorbed on a metal surface are discussed in terms of intramolecular rotational potential.

Prediction of Docetaxel Response in Human Breast Cancer by Gene Expression Profiling

Purpose

Docetaxel is one of the most effective anticancer drugs available in the treatment of breast cancer. Nearly half of the treated patients, however, do not respond to chemotherapy and suffer from side effects. The ability to reliably predict a patient's response based on tumor gene expression will improve therapeutic decision making and save patients from unnecessary side effects.

Patients and Methods

A total of 44 breast tumor tissues were sampled by biopsy before treatment with docetaxel, and the response to therapy was clinically evaluated by the degree of reduction in tumor size. Gene expression profiling of the biopsy samples was performed with 2,453 genes using a high-throughput reverse transcriptase polymerase chain reaction technique. Using genes differentially expressed between responders and nonresponders, a diagnostic system based on the weighted-voting algorithm was constructed.

Results

This system predicted the clinical response of 26 previously unanalyzed samples with over 80% accuracy, a level promising for clinical applications. Diagnostic profiles in nonresponders were characterized by elevated expression of genes controlling the cellular redox environment (ie, redox genes, such as thioredoxin, glutathione-S-transferase, and peroxiredoxin). Overexpression of these genes protected cultured mammary tumor cells from docetaxel-induced cell death, suggesting that enhancement of the redox system plays a major role in docetaxel resistance.

Conclusion

These results suggest that the clinical response to docetaxel can be predicted by gene expression patterns in biopsy samples. The results also suggest that one of the molecular mechanisms of the resistance is activation of a group of redox genes.

Molecular prediction of response to 5-fluorouracil and interferon-alpha combination chemotherapy in advanced hepatocellular carcinoma

PURPOSE

The prognosis of hepatocellular carcinoma (HCC) is very poor, particularly in patients with tumors that have invaded the major branches of the portal vein. Combination chemotherapy with intra-arterial 5-fluorouracil and subcutaneous interferon-alpha has shown promising results for such advanced HCC, but it is important to develop the ability to accurately predict chemotherapeutic responses.

EXPERIMENTAL DESIGN

We analyzed the expression of 3,080 genes using a polymerase chain reaction-based array in 20 HCC patients who were treated with combination chemotherapy after reduction surgery. After unsupervised analyses, a supervised classification method for predicting chemotherapeutic responses was constructed. To minimize the number of predictive genes, we used a random permutation test to select only significant (P < 0.01) genes. A leave-one-out cross-validation confirmed the gene selection. We also prepared an additional 11 cases for validation of predictive performance.

RESULTS

Hierarchical clustering analysis and principal component analysis with all 3,080 genes revealed distinct gene expression patterns in responders (those with complete response or partial response) and nonresponders (those with stable disease or progressive disease) to the combination chemotherapy. Using a weighted-voting classification method with either all genes or only significant genes as assessed by permutation testing, the objective responses to treatment were correctly predicted in 17 of 20 cases (accuracy, 85%; positive predictive value, 100%; negative predictive value, 80%). Moreover, patients in the validation dataset could be classified into two distinct prognostic groups using 63 predictive genes.

CONCLUSIONS

Molecular analysis of 63 genes can predict the response of patients with advanced HCC and major portal vein tumor thrombi to combination chemotherapy with 5-fluorouracil and interferon-alpha.

Molecular mechanism underlying activation of superoxide-producing NADPH oxidases: roles for their regulatory proteins

The phagocyte NADPH oxidase is dormant in resting cells but becomes activated during phagocytosis to produce superoxide, a precursor of microbicidal oxidants, thereby playing a crucial role in host defence. The catalytic core of this enzyme comprises the two membranous subunits gp91phox/Nox2 and p22phox. The oxidase activation requires the small GTPase Rac and the SH3 domain-containing proteins p47phox and p67phox; they normally exist in the cytoplasm and translocate upon cell stimulation to the membrane. The translocation depends on a stimulus-induced conformational change of p47phox, which leads to the SH3 domain-mediated interaction with p22phox, a binding required for the gp91phox/Nox2-dependent superoxide production. Activation of Nox1, an oxidase that is likely involved in host defence at the colon, requires novel proteins homologous to p47phox and p67phox, designated Noxo1 and Noxa1, respectively. Noxo1 and Noxa1, both expressed abundantly in the colon, are capable of constitutively activating Nox1. The constitutive activation may be due to the property of Noxo1: in contrast with p47phox, Noxo1 seems to normally associate with p22phox, which is required for the Nox1 activation. We will also describe the mechanism underlying regulation of the third oxidase Nox3, which exits in fetal kidney and inner ears.

Molecular-based prediction of early recurrence in hepatocellular carcinoma

BACKGROUND/AIMS

Hepatocellular carcinoma (HCC) has a very poor prognosis, due to the high incidence of tumor recurrence. As the current morphological indicators are often insufficient for therapeutic decisions, we sought to identify additional biologic indicators for early recurrence.

METHODS

We analyzed gene expression using a PCR-based array of 3,072 genes in 100 HCC patients. Informative genes predicting early intrahepatic recurrence were selected by random permutation testing, and a weighted voting prediction method was constructed. Following estimation of prediction accuracy, a multivariate Cox analysis was performed.

RESULTS

By permutation testing, we selected 92 genes demonstrated distinct expression patterns differing significantly between recurrence cases and recurrence-free cases. Our prediction method, using the 20 top-ranked genes, correctly predicted the early intrahepatic recurrence for 29 of 40 cases within the validation group, and the odds ratio was 6.8 (95%CI 1.7-27.5, P = 0.010). The 2-year recurrence rates in the patients with the good signature and those with the poor signature were 29.4 and 73.9%, respectively. Multivariate Cox analysis revealed that molecular-signature was an independent indicator for recurrence (hazard ratio 3.82, 95%CI 1.44-10.10, P = 0.007).

CONCLUSIONS

Our molecular-based prediction method using 20 genes is clinically useful to predict early recurrence of HCC.

Molecular features of non-B, non-C hepatocellular carcinoma: a PCR-array gene expression profiling study

BACKGROUND/AIMS

Hepatocellular carcinoma (HCC) usually develops following chronic liver inflammation caused by hepatitis C or B virus. Through expression profiling in a rare type of HCC, for which the causes are unknown, we sought to find key genes responsible for each step of hepatocarcinogenesis in the absence of viral influence.

METHODS

We used 68 non-B, non-C liver tissues (20 HCC, 17 non-tumor, 31 normal liver) for expression profiling with PCR-array carrying 3072 genes known to be expressed in liver tissues. To select the differentially expressed genes, we performed random permutation testing. A weighted voting classification algorithm was used to confirm the reliability of gene selection. We then compared these genes with the results of previous expression profiling studies.

RESULTS

A total of 220 differentially expressed genes were selected by random permutation tests. The classification accuracies using these genes were 91.8, 92.0 and 100.0% by a leave-one-out cross-validation, an additional PCR-array dataset and a Stanford DNA microarray dataset, respectively. By comparing our results with previous reports on virus-infected HCC, four genes (ALB, A2M, ECHS1 and IGFBP3) were commonly selected in some studies.

CONCLUSIONS

The 220 differentially expressed genes selected by PCR-array are potentially responsible for hepatocarcinogenesis in the absence of viral influence.

Coupling between cyclooxygenases and prostaglandin F(2alpha) synthase. Detection of an inducible, glutathione-activated, membrane-bound prostaglandin F(2alpha)-synthetic activity

Distinct functional coupling between cyclooxygenases (COXs) and specific terminal prostanoid synthases leads to phase-specific production of particular prostaglandins (PGs). In this study, we examined the coupling between COX isozymes and PGF synthase (PGFS). Co-transfection of COXs with PGFS-I belonging to the aldo-keto reductase family into HEK293 cells resulted in increased production of PGF(2alpha) only when a high concentration of exogenous arachidonic acid (AA) was supplied. However, this enzyme failed to produce PGF(2alpha) from endogenous AA, even though significant increase in PGF(2alpha) production occurred in cells transfected with COX-2 alone. This poor COX/PGFS-I coupling was likely to arise from their distinct subcellular localization. Measurement of PGF(2alpha)-synthetic enzyme activity in homogenates of several cells revealed another type of PGFS activity that was membrane-bound, glutathione (GSH)-activated, and stimulus-inducible. In vivo, membrane-bound PGFS activity was elevated in the lung of lipopolysaccharide-treated mice. Taken together, our results suggest the presence of a novel, membrane-associated form of PGFS that is stimulus-inducible and is likely to be preferentially coupled with COX-2.

Novel human homologues of p47phox and p67phox participate in activation of superoxide-producing NADPH oxidases

The catalytic core of a superoxide-producing NADPH oxidase (Nox) in phagocytes is gp91phox/Nox2, a membrane-integrated protein that forms a heterodimer with p22phox to constitute flavocytochrome b558. The cytochrome becomes activated by interacting with the adaptor proteins p47phox and p67phox as well as the small GTPase Rac. Here we describe the cloning of human cDNAs for novel proteins homologous to p47phox and p67phox, designated p41nox and p51nox, respectively; the former is encoded by NOXO1 (Nox organizer 1), and the latter is encoded by NOXA1 (Nox activator 1). The novel homologue p41nox interacts with p22phox via the two tandem SH3 domains, as does p47phox. The protein p51nox as well as p67phox can form a complex with p47phox and with p41nox via the C-terminal SH3 domain and binds to GTP-bound Rac via the N-terminal domain containing four tetratricopeptide repeat motifs. These bindings seem to play important roles, since p47phox and p67phox activate the phagocyte oxidase via the same interactions. Indeed, p41nox and p51nox are capable of replacing the corresponding classical homologue in activation of gp91phox. Nox1, a homologue of gp91phox, also can be activated in cells, when it is coexpressed with p41nox and p51nox, with p41nox and p67phox, or with p47phox and p51nox; in the former two cases, Nox1 is partially activated without any stimulants added, suggesting that p41nox is normally in an active state. Thus, the novel homologues p41nox and p51nox likely function together or in combination with a classical one, thereby activating the two Nox family oxidases.

Identification of expressed genes linked to malignancy of human colorectal carcinoma by parametric clustering of quantitative expression data

BACKGROUND

Individual human carcinomas have distinct biological and clinical properties: gene-expression profiling is expected to unveil the underlying molecular features. Particular interest has been focused on potential diagnostic and therapeutic applications. Solid tumors, such as colorectal carcinoma, present additional obstacles for experimental and data analysis.

RESULTS

We analyzed the expression levels of 1,536 genes in 100 colorectal cancer and 11 normal tissues using adaptor-tagged competitive PCR, a high-throughput reverse transcription-PCR technique. A parametric clustering method using the Gaussian mixture model and the Bayes inference revealed three groups of expressed genes. Two contained large numbers of genes. One of these groups correlated well with both the differences between tumor and normal tissues and the presence or absence of distant metastasis, whereas the other correlated only with the tumor/normal difference. The third group comprised a small number of genes. Approximately half showed an identical expression pattern, and cancer tissues were classified into two groups by their expression levels. The high-expression group had strong correlation with distant metastasis, and a poorer survival rate than the low-expression group, indicating possible clinical applications of these genes. In addition to c-yes, a homolog of a viral oncogene, prognostic indicators included genes specific to glial cells, which gives a new link between malignancy and ectopic gene expression.

CONCLUSIONS

The malignancy of human colorectal carcinoma is correlated with a unique expression pattern of a specific group of genes, allowing the classification of tumor tissues into two clinically distinct groups.

The effect of sildenafil on electrostimulation-induced erection in the rat model

This study was conducted to show the effect of sildenafil on electrostimulation-induced erection in the rat model. Fifteen 12-week-old male Wistar Kyoto rats were used. The intracavernous pressure and arterial blood pressure were simultaneously monitored through electric cavernous nerve stimulation before and after the administration of sildenafil (2 mg/kg). Statistical analysis was performed on maximal intracavernous pressure (MIP), mean arterial blood pressure (MAP), the MIP/MAP and detumescence time. MAP decreased significantly by about 20 mmHg after sildenafil administration. The MIP/MAP increased significantly after sildenafil administration. The effect of sildenafil on the MIP/MAP was marked especially at lower (2-3 Hz) frequencies. The detumescence time significantly increased after sildenafil administration. We have shown that sildenafil is effective for enhancing erection at lower frequencies and prolonging penile erection in rats. After the administration of sildenafil, penile erection would be induced by weak stimuli that will not cause penile erection under normal conditions.

Mosapride, a 5HT-4 receptor agonist, improves insulin sensitivity and glycaemic control in patients with Type II diabetes mellitus

AIMS/HYPOTHESIS

We investigated the potential role of mosapride, a 5HT-4 receptor agonist, in glycaemic control in Type II (non-insulin-dependent) diabetic mellitus patients without autonomic neuropathy.

METHODS

Thirty-four inpatients with Type II diabetes mellitus were randomly assigned to receive either mosapride (5 mg orally three times a day, n=17) or a placebo ( n=17) for 1 week (first study). Changes in blood glucose and insulin were determined basally as well as after intravenous glucose loading. Insulin sensitivity was evaluated during hyperinsulinaemic-normoglycaemic-clamp studies and by measuring the number of and the autophosphorylation of insulin receptors on the erythrocytes of patients ( n=9). Sixty-nine outpatients with Type II diabetes were similarly treated with mosapride or a placebo for 8 weeks (second study). Finally, tissue- specific expression of 5HT-4 receptors was examined by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

Mosapride lowered fasting blood glucose and fructosamine concentrations ( p<0.05) (first study). It significantly increased the number of (Mosapride 3323+/-518 vs 4481+/-786 [ p<0.05], Control 4227+/-761 vs 3275+/-554 per 300 microl erythrocytes) and the tyrosine autophosphorylation (Mosapride 3178+/-444 vs 4043+/-651 [ p<0.05], Control 3721+/-729 vs 3013+/-511 insulin receptor unit) of insulin receptors, as well as glucose utilisation (Mosapride 4.92+/-0.53 vs 5.88+/-0.72 [ p<0.05], Control 4.74+/-0.65 vs 4.70+/-0.31 mg/kg x min). Mosapride treatment for 8 weeks significantly reduced fasting glucose (9.91+/-0.34 vs 8.51+/-0.34 mmol/l, p<0.05), insulin (53.2+/-4.62 vs 40.8+/-5.52 pmol/l, p<0.05) and HbA(1c) (8.61+/-0.20 vs 7.67+/-0.19%, p<0.01) concentrations (second study). The RT-PCR analysis demonstrated specific expression of 5HT-4 receptors in the muscle, but not in the liver or fat tissues.

CONCLUSIONS/INTERPRETATION

Mosapride could improve insulin action at muscle and glycaemic control in Type II diabetic patients.