Gene expression profiles of inflammatory breast cancer: correlation with response to neoadjuvant chemotherapy and metastasis-free survival.

BACKGROUND: Inflammatory breast cancer (IBC) is an aggressive disease. To date, no molecular feature reliably predicts either the response to chemotherapy (CT) or the survival. Using DNA microarrays, we searched for multigene predictors. PATIENTS AND METHODS: The World IBC Consortium generated whole-genome expression profiles of 137 IBC and 252 non-IBC (nIBC) samples. We searched for transcriptional profiles associated with pathological complete response (pCR) to neoadjuvant anthracycline-based CT and distant metastasis-free survival (DMFS) in respective subsets of 87 and 106 informative IBC samples. Correlations were investigated with predictive and prognostic gene expression signatures published in nIBC (nIBC-GES). Supervised analyses tested genes and activation signatures of 19 biological pathways and 234 transcription factors. RESULTS: Three of five tested prognostic nIBC-GES and the two tested predictive nIBC-GES discriminated between IBC with and without pCR, as well as two interferon activation signatures. We identified a 107-gene signature enriched for immunity-related genes that distinguished between responders and nonresponders in IBC. Its robustness was demonstrated by external validation in three independent sets including two IBC sets and one nIBC set, with independent significant predictive value in IBC and nIBC validation sets in multivariate analysis. We found no robust signature associated with DMFS in patients with IBC, and neither of the tested prognostic GES, nor the molecular subtypes were informative, whereas they were in our nIBC series (220 stage I-III informative samples). CONCLUSION: Despite the relatively small sample size, we show that response to neoadjuvant CT in IBC is, as in nIBC, associated with immunity-related processes, suggesting that similar mechanisms responsible for pCR exist. Analysis of a larger IBC series is warranted regarding the correlation of gene expression profiles and DMFS.

Potent inhibition by ropivacaine of metastatic colon cancer SW620 cell invasion and NaV1.5 channel function.

BACKGROUND: Metastatic breast and colon cancer cells express neonatal and adult splice variants of NaV1.5 voltage-activated Na(+) channels (VASCs). Block of VASCs inhibits cell invasion. Local anaesthetics used during surgical tumour excision inhibit VASC activity on nociceptive neurones providing regional anaesthesia. Inhibition of VASCs on circulating metastatic cancer cells may also be beneficial during the perioperative period. However, ropivacaine, frequently used to provide analgesia during tumour resection, has not been tested on colon cancer cell VASC function or invasion. METHODS: We used reverse transcription-polymerase chain reaction and sequencing to identify NaV1.5 variants in the SW620 metastatic colon cancer cell line. Recombinant adult and neonatal NaV1.5 variants were expressed in human embryonic kidney cells. Voltage-clamp recordings and invasion assays were used to examine the effects of ropivacaine on recombinant NaV1.5 channels and the metastatic potential of SW620 cells, respectively. RESULTS: SW620 cells expressed adult and neonatal NaV1.5 variants, which had similar steady-state inactivation profiles, but distinctive activation curves with the neonatal variant having a V1/2 of activation 7.8 mV more depolarized than the adult variant. Ropivacaine caused a concentration-dependent block of both NaV1.5 variants, with IC50 values of 2.5 and 3.9 µM, respectively. However, the reduction in available steady-state current was selective for neonatal NaV1.5 channels. Ropivacaine inhibited SW620 invasion, with a potency similar to that of inhibition of NaV1.5 channels (3.8 µM). CONCLUSIONS: Ropivacaine is a potent inhibitor of both NaV1.5 channel activity and metastatic colon cancer cell invasion, which may be beneficial during surgical colon cancer excision.

International expert panel on inflammatory breast cancer: consensus statement for standardized diagnosis and treatment.

BACKGROUND: Inflammatory breast cancer (IBC) represents the most aggressive presentation of breast cancer. Women diagnosed with IBC typically have a poorer prognosis compared with those diagnosed with non-IBC tumors. Recommendations and guidelines published to date on the diagnosis, management, and follow-up of women with breast cancer have focused primarily on non-IBC tumors. Establishing a minimum standard for clinical diagnosis and treatment of IBC is needed. METHODS: Recognizing IBC to be a distinct entity, a group of international experts met in December 2008 at the First International Conference on Inflammatory Breast Cancer to develop guidelines for the management of IBC. RESULTS: The panel of leading IBC experts formed a consensus on the minimum requirements to accurately diagnose IBC, supported by pathological confirmation. In addition, the panel emphasized a multimodality approach of systemic chemotherapy, surgery, and radiation therapy. CONCLUSIONS: The goal of these guidelines, based on an expert consensus after careful review of published data, is to help the clinical diagnosis of this rare disease and to standardize management of IBC among treating physicians in both the academic and community settings.

Identification of epidermal cell subpopulations with increased ornithine decarboxylase activity following treatment of murine epidermis with 12-O-tetradecanoylphorbol-13-acetate.

Ornithine decarboxylase (ODC), the initial enzyme in the polyamine biosynthetic pathway, has been used as a marker for the hyperplasia that occurs following exposure of mouse epidermis to the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). Using flow cytometry in combination with polyclonal antibodies to ODC, we examined the levels of ODC-associated immunoreactive protein present within mouse epidermal cells at 4 and 24 h after a single topical application of TPA, as well as following chronic exposure to TPA and in papillomas. Basal levels of ODC-specific antibody binding were detectable in acetone-treated CD-1 mouse epidermis and were increased 3-fold at 4 h after TPA treatment. The amount of ODC antibody binding detected after exposure to 17 nmol TPA twice weekly for 3 weeks was similar to that detected within cells isolated from papillomas and was 2.5-fold higher than in cells isolated at 4 h after a single topical treatment of mice with TPA. These observations support the hypothesis that specific subpopulations of keratinocytes constitutively express high levels of ODC following chronic exposure to TPA. The novel method for ODC detection described in these studies provides a means to identify, isolate, and further characterize epidermal cells that may give rise to papillomas and carcinomas.

Production of hydrogen peroxide by murine epidermal keratinocytes following treatment with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate.

The ability of murine epidermal cells to produce intracellular hydrogen peroxide was analyzed by flow cytometry and the measurement of 2',7'- dichlorofluorescin (DCFH) oxidation. Epidermal cells isolated from acetone-treated CD-1 mice for 24 h were relatively homogeneous in cell size and density and oxidized low levels of DCFH. However, following 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment of mice (10 micrograms; 24 h), two cytokeratin-positive populations of cells were identified that were heterogeneous with respect to size and density. These two TPA-derived cell populations oxidized levels of DCFH that were time and dose dependent and were between 2- and 10-fold higher than levels of DCFH oxidized by cells isolated from acetone-treated mice. The ability of catalase, the enzyme that detoxifies hydrogen peroxide, to suppress DCFH oxidation to control levels suggested that intracellular hydrogen peroxide was responsible for the enhanced rate of DCFH oxidation in epidermal cells isolated from TPA-treated mice. The ability of mouse epidermal keratinocytes to oxidize DCFH in response to TPA treatment was confirmed using a cloned keratinocyte cell line. These results suggest that specific subpopulations of keratinocytes produce elevated levels of intracellular peroxides following treatment with TPA either in vivo or in culture.

Temporal sequence of pulmonary cytokine gene expression in response to endotoxin in C3H/HeN endotoxin-sensitive and C3H/HeJ endotoxin-resistant mice.

Although previous studies suggested that tumor necrosis factor alpha (TNF-alpha) was a critical cytokine responsible for the inflammation observed after exposure to endotoxin, other mediators may also play an important role in the regulation of systemic inflammatory responses independent of TNF-alpha. The present study compared the temporal sequence of endotoxin-induced TNF-alpha, interleukin-1 alpha (IL-1 alpha), and interleukin-10 (IL-10) gene expression and cellular localization of cytokine proteins in pulmonary tissue of two strains of mice that have a genetically based differential sensitivity to endotoxin. Lung tissue and plasma were harvested from endotoxin-sensitive C3H/HeN and endotoxin-resistant C3H/HeJ mice at 15 min, 30 min, 1 h, 2 h, 4 h, 6 h, 12 h, and 24 h after intraperitoneal (i.p.) injection of 5 mg/kg endotoxin (Escherichia coli-derived lipopolysaccharide, serotype 0111:B4). There were significant elevations in both TNF-alpha gene and IL-1 alpha expression immediately (15 min) after endotoxin injection in C3H/HeN mice. Although levels of TNF-alpha mRNA in the two mouse strains were similar at 1-2 h, the IL-1 alpha gene expression in pulmonary tissue isolated from endotoxin-resistant mice was not comparable to the levels detected in C3H/HeN endotoxin-sensitive mice at the same times. The most dramatic difference in endotoxin-induced cytokine gene expression between the two strains of mice was in IL-10 mRNA levels in pulmonary tissue isolated from endotoxin-sensitive mice, compared to the lack of detectable increase in IL-10 gene expression in C3H/HeJ endotoxin-resistant mice above baseline at any time point examined. Quantitation of neutrophil infiltration into pulmonary tissue using immunochemical detection of GR-1, a myeloid differentiation-specific antibody, demonstrated that there was a significantly decreased inflammatory infiltrate in pulmonary tissue isolated from C3H/HeJ mice following endotoxin administration, which correlated with decreased levels of proinflammatory cytokine immunoreactive protein within pulmonary cells. Pulmonary cytokine synthesis and immunoreactive protein production did not directly correlate with either the magnitude or the temporal sequence of increases in plasma cytokine levels, suggesting that systemic levels of cytokines may not accurately reflect the cytokine response within the local tissue milieu. The present observations demonstrate that the differential synthesis and production of immunosuppressive cytokines as well as proinflammatory cytokines may be important variables in the determination of the extent of infiltration of inflammatory cells into the local pulmonary site in response to endotoxin and may significantly contribute to the determination of sensitivity or resistance to endotoxin in this murine model.

Distinct patterns of chemotactic peptide-induced calcium mobilization in differentiated myeloid leukemia cells and peripheral blood neutrophils.

Flow cytometry was used to compare intracellular calcium mobilization in mature neutrophilic granulocytes (PMN) with HL-60 promyelocytic leukemia cells induced to differentiate with dibutyryl cyclic adenosine 3',5'-monophosphate (dbcAMP). Using the calcium-specific probe indo-1 acetoxymethyl ester, we found that the ability of differentiating HL-60 cells to mobilize calcium in response to N-formyl-methionyl-leucyl-phenylalanine (fMLP) developed concomitantly with expression of receptors on the cells for this peptide. Mobilization of calcium in HL-60 cells, as well as in PMN, in response to fMLP was dose dependent and was related to the presence of calcium in the culture medium. In calcium-free medium, tenfold higher concentrations of fMLP were required to induce calcium mobilization than in calcium-containing medium. In HL-60 cells, calcium mobilization occurred more rapidly than in PMN and was independent of extracellular calcium. Furthermore, the response of HL-60 cells to fMLP was more prolonged than the response of PMN and was also of greater magnitude. Calcium mobilization in both HL-60 cells and PMN was partially inhibited by the calcium channel blocker, verapamil, but completely blocked by trimethylbenzoic acid 8-(diethylamino) octyl ester, an intracellular calcium antagonist. These results indicate that although both cell types mobilize calcium in response to fMLP, the characteristics of the responses are distinct. These differences may underlie distinct functional responses of PMN and differentiated HL-60 cells to fMLP.

Failure of F-Met-Leu-Phe to induce chemotaxis in differentiated promyelocytic (HL-60) leukemia cells.

Treatment of HL-60 promyelocytic leukemia cells with dibutyryl cyclic adenosine 3',5'-monophosphate (dbcAMP) induced these cells to differentiate toward mature neutrophilic granulocytes (PMN). DbcAMP was found to produce a rapid time- and dose-dependent inhibition of HL-60 cell proliferation, reaching a maximum after 48 hr treatment of the cells with 250-500 microM. This was associated with morphologic alterations consistent with maturing PMN. Using immunofluorescence and flow cytometry, we found that dbcAMP-treated HL-60 cells expressed some, but not all, surface markers characteristic of mature phagocytes. Thus receptors for the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP); the monocyte/granulocyte markers My-8, Mo-1, and Leu-15; as well as the monocyte markers Mo-2 and My-4 were identified on the cells. In contrast, dbcAMP-treated cells did not express the PMN-specific antigen DL1.2. We also found that dbcAMP-treated HL-60 cells produced hydrogen peroxide in response to the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA). However, the magnitude of this response was significantly less than that observed in mature PMN. In contrast, fMLP-stimulated levels of hydrogen peroxide production were comparable in both cell types. In addition, despite the fact that dbcAMP-treated cells expressed fMLP receptors, they did not exhibit directed migration toward this chemotactic peptide. Taken together, these data suggest that dbcAMP-induced differentiation of HL-60 cells is incomplete.

Mutagenic potential of peripheral blood leukocytes: in vivo exposure to the carcinogen 7,12-dimethylbenz[a]anthracene, and the tumor promoter 12-O-tetradecanoylphorbol acetate followed by in vitro co-culture with AS52 cells.

Co-culture of AS52 cells with peripheral blood leukocytes (PBLs), obtained from SENCAR mice topically treated with either tetradecanoyl-phorbol-13-acetate (TPA) or 7,12-dimethylbenz[a]anthracene (DMBA)-TPA, resulted in a 7-160-fold increase in the mutation frequency of the gpt gene in AS52 cells when compared to that induced by PBLs isolated from mice treated with either acetone or DMBA. This increase in mutation frequency was inhibited by the anti-oxidant (-)epigallocatechin gallate (EGCG). These results demonstrate that the AS52 cell line can be used as a mammalian mutagenesis model for the study of in vivo mechanism(s) of mutagenesis by leukocytes and also as a model for in vivo chemoprevention studies.

Ibuprofen-induced inhibition of cyclooxygenase isoform gene expression and regression of rat mammary carcinomas.

A single dose of 75 mg/kg 7,12 dimethylbenz[a]anthracene was administered to 50-day-old virgin female Sprague-Dawley rats and 100 days later, animals were randomized and provided with Teklad rodent chow mixed with a dose of 25 mg/rat/day ibuprofen for 35 days. Ibuprofen treatment reduced tumor volume (P < 0.05) and significantly inhibited gene expression of both cyclooxygenase- and cyclooxygenase-2 (P < 0.02). These results indicate that ibuprofen induced significant regression of established mammary carcinomas which was associated with inhibition of expression of isoforms of the gene responsible for prostaglandin production.

Correlation of aromatase and cyclooxygenase gene expression in human breast cancer specimens.

Aromatase, the enzyme system catalyzing estrogen biosynthesis, is found in stromal tissue in the breast. The increased expression of the aromatase CYP19 gene in breast cancer tissues was recently associated with a promoter region regulated through cAMP-mediated pathways. PGE2, derived from cyclooxygenase, increases intracellular cAMP levels and stimulates estrogen biosynthesis. This association suggest that local production of PGE2 via cyclooxgenase isozymes may influence estrogen biosynthesis. The present study represents the first to examine the levels of mRNA expression of CYP19, COX-1, and COX-2 genes in human breast cancer specimens and normal breast tissue samples using semi-quantitative RT-PCR methods. Positive correlations were observed between CYP19 and COX-2 and the greater extent of breast cancer cellularity. Linear regression analysis using a bivariate model shows a strong linear association between CYP19 expression and the sum of COX-1 and COX-2 expression. This significant relationship between the aromatase and cyclooxygenase enzyme systems suggests that autocrine and paracrine mechanisms may be involved in hormone-dependent breast cancer development via growth stimulation from local estrogen biosynthesis.

Detrimental hemodynamic effects of nitric oxide synthase inhibition in septic shock.

OBJECTIVE: To investigate the physiologic effects of nitric oxide synthase inhibition with N-nitro-L-arginine methyl ester in an acute resuscitated model of porcine septic shock. DESIGN: Randomized control trial. SETTING: Animal research facility. STUDY SUBJECTS: Domestic Yorkshire swine. INTERVENTIONS: Twenty-four animals were randomly divided into one of four treatment groups as follows: normal saline resuscitation (NSR) (control group); NSR plus 200 micrograms/kg of lipopolysaccharide (LPS) at 1 hour after baseline (LPS group); NSR, LPS, and a continuous infusion of 50 micrograms/kg per minute of N-nitro-L-arginine methyl ester (NAME) at 1 hour after baseline (LPS/NAME group); and NSR and NAME (NAME group). All animals received NSR at 1 mL/kg per minute starting at baseline. MAIN OUTCOME MEASURES: Mean arterial pressure (MAP), systemic vascular resistance index (SVRI), mean pulmonary arterial pressure (MPAP), and pulmonary vascular resistance index (PVRI) were measured at baseline and hourly for 4 hours. Values at baseline and 3 hours are given below as mean (+/- SE). RESULTS: All variables remained unchanged in the control group. The administration of LPS produced a systemic hyperdynamic response characterized by a decrease in MAP and SVRI from 66.0 +/- 3.9 to 55.0 +/- 2.8 mm Hg (P < .05) and from 422.0 +/- 22.0 to 272.0 +/- 29.0 mm Hg.min.kg/L (P < .05), respectively. The administration of LPS produced an increase in MPAP and PVRI from 16.3 +/- 0.8 to 30.0 +/- 1.3 mm Hg (P < .05) and from 37.0 +/- 5.3 to 119.0 +/- 13.0 mm Hg.min.kg/L (P < .05), respectively. In the LPS/NAME group, NAME infusion normalized MAP and increased SVRI from 506.0 +/- 40.0 to 642.0 +/- 72.0 mm Hg.min.kg/L (P < .05). Infusion of NAME potentiated LPS-induced pulmonary hypertension, increasing MPAP and PVRI from 16.8 +/- 0.6 to 36.0 +/- 2.8 mm Hg (P < .05) and from 59.0 +/- 3.5 to 319.0 +/- 64.0 mm Hg.min.kg/L (P < .05), respectively. Infusion of NAME alone increased MAP from 74.0 +/- 1.3 to 100.0 +/- 4.1 mm Hg (P < .05) and had no significant effect on MPAP and PVRI. CONCLUSIONS: The potentiation of LPS-induced pulmonary hypertension following NAME infusion suggests that inhibition of nitric oxide synthase may have a limited role in the treatment of septic shock.

Differential production of interleukin 1 on the surface of biomaterials.

The production of cytokines on the surface of surgical biomaterials plays a major role in their biocompatibility. Membrane-associated interleukin 1 (mIL-1) is a cytokine found on the surface of macrophages activated by biomaterials. To better understand the host-foreign body interaction, we quantitated the production of mIL-1 on the surface of two materials commonly used in surgery, expanded polytef (ePTFE) and silicon elastomer (SE). The mean (+/- SD) level of mIL-1 produced by adherent cells to ePTFE significantly decreased from day 2 (13,746 +/- 3630 cpm per disk) compared with day 7 (2828 +/- 1304 cpm per disk). However, the level of mIL-1 produced by ePTFE-adherent cells was still markedly greater than the level of mIL-1 produced by cells adherent to SE (1877 +/- 1028 vs 1595 +/- 822 cpm per disk). These results indicate that ePTFE and SE elicit a differential host response in terms of cytokine production. This study may enhance our understanding of the cellular events on the surface of biomaterials that underlie clinical observations.

Mechanisms of nitric oxide-induced cytotoxicity in normal human hepatocytes.

Chronic exposure of hepatocytes to reactive nitrogen species (RNS) following liver injury and inflammation leads not only to functional and morphological alterations in the liver but also to degenerative liver diseases and hepatocellular carcinoma. Previously, we showed that S-nitroso-N-acetylpenicillamine-amine (SNAP), which generates nitric oxide, and 3-morpholinosydnonimine (Sin-1), which generates equal molar concentrations of superoxide and nitric oxide resulting in peroxynitrite production, exhibited different levels of cytotoxicity to normal human hepatocytes in culture. The aim of the present study was to elucidate some of the molecular and cellular pathways leading to hepatocyte cell death induced by RNS. Following treatment of the hepatocytes with SNAP or Sin-1, gene-specific DNA damage was measured in mtDNA and a hprt gene fragment using a quantitative Southern blot analysis. Both agents induced dose-dependent increases in DNA damage that was alkaline labile, but not sensitive to both formamidopyrimidine-DNA glycosylase (fpg) and endonuclease III, which recognize 8-oxoguanine, thymine glycol, and other oxidized pyrimidines. DNA damage was two- to fivefold greater in mtDNA than in the hprt gene fragment. There was a persistent and marked increase in DNA damage posttreatment that appeared to arise from the disruption of electron transport in the mitochondria, generating reactive species that saturated the repair system. DNA damage induced by Sin-1 and SNAP led to cell-cycle arrest in the S-phase, growth inhibition, and apoptosis. The data support the hypothesis that the functional and morphological changes observed in liver following chronic exposure to RNS are, in part, the result of persistent mitochondrial and nuclear DNA damage.

Modification of the "push" technique for percutaneous endoscopic gastrostomy in infants and children.

BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) by the "push" technique avoids peri-catheter infection, repeated insertion of the endoscope, potential esophageal injury from the catheter, and the possible need for another endoscopy for catheter removal associated with the "pull" technique. In small infants, however, the "push" technique could result in loss of gastric insufflation and pneumoperitoneum during tract dilatation. A simple modification of the "push" technique has eliminated this problem. STUDY DESIGN: During a 16-month period, 22 infants and children underwent PEG insertion using our modified "push" technique. These cases were reviewed for patient characteristics including age, weight, indication for the procedure, duration of the procedure, cost, conversion to open technique, and complications. RESULTS: We have used the modified "push" technique to place PEG tubes in 20 infants and children aged four weeks to 15 years (mean, 13 months), weighing 2.7 to 36 kg (median, 6.0 kg), indicated for failure to thrive due to cystic fibrosis (n=3) or neurologic impairment (n=10). These patients have had follow-up examination from nine to 30 months after the procedure. Operative time averaged 15 minutes. The "push" technique was successful in 95 percent of patients with one failure caused by loss of gastric insufflation when Fogarty balloons failed. All PEGs were used within 24 hours. There were no deaths and no peri-catheter infections. CONCLUSIONS: A simple modification of the "push" technique of PEG insertion eliminated problems with loss of gastric insufflation previously encountered in small infants. The modified "push" technique is safe, simple, and quick, obviating potential risks inherent in the "pull" technique when applied in infants.

Prenatal diagnosis and management of gastrointestinal anomalies.

The increased use of prenatal sonography has led to earlier and more frequent diagnosis of a wide range of gastrointestinal anomalies. Many of these anomalies are associated with other severe cardiac, renal, and genetic abnormalities that may impact on decisions regarding timing and site of delivery. The majority of these patients should be referred to a center that provides perinatal, neonatal, and pediatric surgical expertise. After a complete prenatal evaluation, a decision regarding the site of delivery and the need for subspecialty referral can be made. Prenatal diagnosis of the conditions discussed in this article does not influence the mode of delivery, but subsequent management of the newborn is improved by delivery in a tertiary care center.

Prenatal diagnosis and management of the fetus with an abdominal wall defect.

Prenatal ultrasound has advanced our understanding of congenital abdominal wall defects. In addition to providing insights into the divergent embryological origins and natural history of abdominal wall defects, ultrasound has had an important impact on the management of these anomalies. For fetuses with gastroschisis, the changes in appearance of the bowel may suggest expeditious delivery. In cases of omphalocele, the presence of additional anomalies is significantly associated with the ultimate prognosis for these fetuses. Giant omphalocele may preclude vaginal delivery secondary to dystocia. Exstrophies of the cloaca and bladder are rare congenital abnormalities that often present complex management issues, including gender reassignment in cases of cloacal exstrophy, for those couples wishing to continue the pregnancy. We believe that the optimal management of a fetus diagnosed with an abdominal wall defect requires a coordinated effort among specialists from maternal fetal medicine, pediatric surgery, and pediatrics.

Inhibition of cutaneous UV light-induced tumor necrosis factor-alpha protein production by Allotrap 1258, a novel immunomodulatory peptide.

Peptides derived from the heavy chain of the HLA Class-I molecules have been shown to modulate immune responses both in vivo and in vitro. Using a computer-aided rational drug design approach, novel immunomodulatory peptides were designed based on peptide 2702.75-85, derived from HLA-B2702. Several peptides were identified which had increased immunomodulatory activity, including peptides RDP1258 and its D-isomer the peptide Allotrap 1258. The present study using Skh/hr hairless mouse skin model evaluated the in vivo effects of Allotrap 1258 on acute UVB-induced skin inflammation. Here we demonstrate that intraperitoneal administration of Allotrap 1258 1 h prior to UV exposure resulted in significantly diminished levels of UV-induced tumor necrosis factor (TNF)-alpha protein production in the epidermis but had no effect on other parameters of the acute UV-induced inflammatory response. By virtue of its ability to suppress TNF-alpha protein production, Allotrap 1258 could prove to be an effective modulator of inflammatory responses.

Comparative chemopreventive activity of ibuprofen and N-(4-hydroxyphenyl) retinamide against the development and growth of rat mammary adenocarcinomas.

The chemopreventive effects of Ibuprofen on the development and growth of 7,12-dimethylbenz(a)anthracene (DMBA) induced rat mammary tumors were examined. A well known breast cancer chemopreventive retinoid, N-(4-hydroxyphenyl) retinamide (4-HPR) was also included in this study for comparison. At 7 days prior to receiving a single intragastric dose of 15 mg DMBA, rats were fed a control chow diet, as well as diets containing either 1000 mg/kg diet of Ibuprofen or 1.5 mmol/kg diet of 4-HPR. Ibuprofen and 4-HPR markedly increased tumor latency. At 112 days post DMBA intubation, tumor incidence was 86% in control rats as compared to 74% and 62% in rats receiving Ibuprofen, and 4-HPR diets respectively (p < 0.05). Ibuprofen and 4-HPR reduced tumor burden and tumor volume almost to the same extent. The control rats had an average of 2.26 tumors/rat compared to 1.42 and 1.46 tumors/rat in the Ibuprofen or 4-HPR groups respectively (p < 0.05). Similarly, average tumor volume was 3.25 cm3 in the control rats compared to 0.86 cm3 and 0.83 cm3 in rats receiving Ibuprofen and 4-HPR diets respectively (p < 0.05). These results suggest that Ibuprofen may have potential in the chemoprevention and treatment of breast cancer.

Comparative ability of ibuprofen and N-(4-hydroxyphenyl)retinamide to inhibit development of rat mammary adenocarcinomas associated with differential inhibition of gene expression of cyclooxygenase isoforms.

A rodent model of carcinogen-induced mammary tumorigenesis was used to determine the comparative growth inhibitory effects of dietary administration of either 1000 mg/kg of the non-steroidal antiinflammatory drug (NSAID) ibuprofen or 1.5 mmol/kg of the synthetic retinoid N-(4-hydroxyphenyl)-retinamide (4-HPR). In addition, the effects of these compounds on gene expression and protein production of the two isoforms of the cyclooxygenase (COX) gene which are responsible for prostaglandin production were examined. Experimental diets were provided to rats beginning at 7 days prior to administration of a single intragastric dose of 15 mg dimethylbenz[a]anthracene (DMBA) and diets were provided ad libitum until the study was terminated at 16 weeks later. Ibuprofen significantly decreased levels of gene expression of both COX-1 and COX-2 (p < 0.01). Although dietary 4-HPR did significantly diminish levels of COX-1 gene expression (p < 0.01) in rat mammary adenocarcinomas, this synthetic retinoid did not significantly inhibit COX-2 gene expression. COX-1 protein was localized to endothelial cells, infiltrating inflammatory cells, and tumor cells, while COX-2 protein was detected primarily within tumor cells. Although ibuprofen was more effective in inhibiting COX-2 gene expression than 4-HPR, ibuprofen and 4-HPR were equally effective in inhibiting development of carcinogen-induced mammary adenocarcinomas.