Differential immunohistochemical localization of xanthine oxidase in normal and neoplastic human breast epithelium

Xanthine oxidase (XO) and xanthine dehydrogenase (XDH) are alternate enzymatic forms of the XO/XDH protein that catalyzes the oxidation of hypoxanthine to xanthine, and xanthine to uric acid, and in the process XO/XDH generates reactive oxygen species (ROS) such as superoxide, hydrogen peroxide, and hydroxyl radicals. We hypothesize that XO/XDH, which is expressed in mammary epithelium, contributes to the development of breast cancers by virtue of its ability to generate genotoxic ROS. In this study, we produced human XO/XDH protein at high levels in Spodoptera frugiperda (Sf9) insect cells using the baculovirus vector to confirm the specificity of antibodies used for immunostaining of human breast tissues. Immunoblot analysis demonstrated that the full length 143 kDa polypeptide was partially processed into a 87 kDa and 59 kDa fragments. The overexpressed XO/XDH protein was identified in the cytoplasm of insect cells by immunofluorescence staining. Using these antibodies we analyzed normal and neoplastic breast epithelium for the presence of XO/XDH. Immunohistochemical analysis of normal human breast revealed the presence of XO/XDH in the cytoplasm of epithelium lining terminal ducts. The intensity of XO/XDH staining was markedly enhanced in alveolar epithelium of lactating mammary lobules. In contrast, no immunohistochemically detectable XO/XDH was observed in intraductal in situ carcinomas and in invasive carcinomas of the breast. Further studies are necessary to confirm the utility of the loss of XO/XDH expression as a marker for neoplastic change in the breast and investigate the functional role of this enzyme in the pathogenesis of breast cancer.

Is funding source related to study reporting quality in obesity or nutrition randomized control trials in top-tier medical journals?

BACKGROUND

Faithful and complete reporting of trial results is essential to the validity of the scientific literature. An earlier systematic study of randomized controlled trials (RCTs) found that industry-funded RCTs appeared to be reported with greater quality than non-industry-funded RCTs. The aim of this study was to examine the association between systematic differences in reporting quality and funding status (that is, industry funding vs non-industry funding) among recent obesity and nutrition RCTs published in top-tier medical journals.

METHODS

Thirty-eight obesity or nutrition intervention RCT articles were selected from high-profile, general medical journals (The Lancet, Annals of Internal Medicine, JAMA and the British Medical Journal) published between 2000 and 2007. Paired papers were selected from the same journal published in the same year, one with and the other without industry funding. The following identifying information was redacted: journal, title, authors, funding source and institution(s). Then three raters independently and blindly rated each paper according to the Chalmers method, and total reporting quality scores were calculated.

FINDINGS

The inter-rater reliability (Cronbach's alpha) was 0.82 (95% confidence interval = 0.80-0.84). The total mean (M) and s.d. of Chalmers Index quality score (out of a possible 100) for industry-funded studies were M = 84.5, s.d. = 7.04 and for non-industry-funded studies they were M = 79.4, s.d. = 13.00. A Wilcoxon matched-pairs signed-ranks test indicates no significant rank difference in the distributions of total quality scores between funding sources, Z = -0.966, P = 0.334 (two tailed).

INTERPRETATION

Recently published RCTs on nutrition and obesity that appear in top-tier journals seem to be equivalent in quality of reporting, regardless of funding source. This may be a result of recent reporting of quality statements and efforts of journal editors to raise all papers to a common standard.

A phase I trial of tumor-associated antigen-pulsed dendritic cell immunotherapy for patients with brain stem glioma and glioblastoma

2032

Background: Previous immunotherapy trials for malignant glioma (Yu, J.,et al, Cancer Res. 2001;61:842–7 and 2004;64;4973–9) have demonstrated efficacy in generating a tumor specific immune response. Here we set out to determine feasibility and immunogenecity of dendritic vaccination with specific glioma-associated antigens. Methods: The goal of this study is to use tumor associated antigens (TAA) known to be expressed on gliomas and pulse dendritic cells with these antigens in an MHC compatible fashion using epitopes of HER-2, TRP-2, gp100, MAGE-1, IL13R alpha, and AIM-3. In this phase I trial, HLA-A1 and/or HLA-A2-positive patients with newly diagnosed or recurrent glioblastoma were eligible. Leukapheresis was used to isolate mononuclear cells which were differentiated into dendritic cells in culture, pulsed with tumor peptide, and then administered intradermally three times at 2-week intervals. Results: Twenty patients, 15 males and five females, were enrolled between November 2006 and December 2008 with one screen failure. The median patient age was 47 years (range: 26–65) and patients had a median Karnofsky performance status of 90% (range: 90–100). There were 16 newly diagnosed and three recurrent glioblastoma multiforme (GBM) patients, who underwent surgery prior to vaccination. Our data on 19 patients and 54 courses of dendritic cell vaccines demonstrate zero grade 3 /4 toxicities that were attributable to the vaccination. Thirteen patients continue to have stable disease (ranging from 15 to 115 weeks), six patients have demonstrated tumor progression. Median survival from surgery was 60 weeks (ranging from 26 to 115 weeks). Of 15 patients tested to date, six patients demonstrated an antigen-specific cytotoxic T-cell response to at least one antigen after vaccination. Only 17% of CTL responders (1/6) demonstrated tumor progression compared to 56% (5/9) of nonresponders to date. Conclusions: This phase I study demonstrated the feasibility, safety, and bioactivity of a TAA-pulsed dendritic cell vaccine for patients with glioblastoma progression free survival correlated with CTL response.

[Table: see text]

A phase I trial of surgical resection with biodegradable carmustine (BCNU) wafer placement followed by vaccination with dendritic cells pulsed with tumor lysate for patients with malignant glioma

2033

Background: Our prior immunotherapy trials demonstrated efficacy in generating a tumor specific immune response in malignant glioma and the potential for high tumor-specific toxicity and sustained tumoricidal activity. Immunotherapy may synergize with chemotherapy and biodegradable carmustine (BCNU) wafers extend overall survival from 11.6 to 13.9 months. Methods: We exploited this synergistic effect to maintain a cytotoxic environment around the tumor milieu. Patients with high-grade glioma were eligible after maximal resection with biodegradable carmustine (BCNU) wafer placement. Screening leukapheresis is used to isolate mononuclear cells which are differentiated into dendritic cells, pulsed with tumor lysate, and then 3 intradermal vaccines are administered at 2-week intervals. Patients continued systemic chemotherapy after vaccine or at progression. Results: Eighteen patients have been enrolled (7 Male, 11 Female) between April 2007 and February 2009 with one screen failure and two patients with clinical progression prior to vaccination. The median patient age was 57 years (26 to 74 ) and median Karnofsky performance status was 90% (80–100). The histology included 3 newly diagnosed glioblastoma multiforme (GBM), 8 recurrent GBM, 2 newly diagnosed anaplastic astrocytoma (AA), and 2 recurrent AA. 15 patients were successfully treated by vaccine injections with 12 patients receiving vaccine every 2 weeks x 3 followed by adjuvant chemotherapy. Our preliminary data on 15 patients and 39 courses of Dendritic Cell vaccines demonstrate one grade 3 toxicity of fever/chest pain. A stable disease interval of 13 to 90 weeks was observed for patients who received vaccine. The 3 newly diagnosed GBM patients have stable disease (18 to 71 weeks). In the recurrent GBM cohort 7/8 patients had progression within 6 months from the post-vaccination MRI. Conclusions: This phase I study demonstrates the safety, feasibility of dendritic cell vaccination with biodegradable carmustine (BCNU) wafers with one grade 3 AE. Immunological data is pending to determine potential synergy of dendritic cell vaccination with intracranial chemotherapy.

No significant financial relationships to disclose.

Molecular analysis of the selective pro-apoptotic effect of BN107 on estrogen receptor negative breast cancer cells

Abstract #3128

While advances in early detection and adjuvant therapy for breast cancer have had a favorable impact on survival, patients who develop metastatic breast cancer generally succumb to death. Hormonal, targeted or chemotherapeutic strategies largely depend on the expression of their cognate receptors and are often accompanied by toxicities and intolerable side effects. Effective and less toxic therapies against the more aggressive and hormonal therapy-resistant estrogen receptor negative (ER-) breast cancer are urgently needed.
 Botanical medicine is one of the most popular complementary and alternative medical approaches, and Chinese herbal therapies are frequently sought and used by breast cancer patients. However, the molecular mechanisms through which certain herbal extracts exert anti-breast cancer activities remain largely unknown. Bionovo Inc. has a pipeline of anti-breast cancer products (BN#) based on herbal medicine in development. Here, we present preclinical data on the potential mechanisms of the pro-apoptotic effect of BN107 on breast cancer cells.
 A panel of breast cancer cell lines was examined and the most significant cytotoxic effect was observed in the less-differentiated, more aggressive, ER- breast cancer lines. Apoptosis appeared to be the major cellular pathway mediating the cytotoxicity of BN107 as evident from Annexin V binding, dissipation of mitochondrial potential, activation of caspases, and DNA fragmentation. Transcriptomic analysis comparing sensitive (ER+) versus resistant (ER-) cell lines revealed distinct patterns of gene expression in response to BN107. ER- breast cancer cells responded to BN107 by upregulating genes involved in apoptotic responses and cholesterol synthesis pathways; while ER+ breast cancer cells did so by regulating genes involved in cell growth and IGF-1 receptor signaling pathways. Further molecular analysis showed that BN107 induced death preferentially in ER- cells via rapid inactivation of AKT/ mTOR pathways. In addition, the sensitivity to BN107 was greatly reduced when ER expression was introduced in MDA-MB-231, an ER- cell line highly sensitive to BN107.
 BN107, an extract rich in triterpenoids, caused rapid alterations in cholesterol metabolism, presumably by interfering with cell membrane permeability/integrity. Co-administration of BN107 and cholesterol abolished the pro-apoptotic effect of BN107. We found that ER- breast cancer cells rich in caveolae/lipid rafts were highly sensitive to BN107. We showed that BN107 treatment in these cells resulted in subcellular redistribution of proteins that are associated with these specialized membrane/cellular structures.
 In conclusion, BN107 exerts pro-apoptotic activity preferentially on the more aggressive, ER- breast cancer cells. The cytotoxic activity of BN107 may be attributed to its ability to modify membrane permeability/integrity. Activity-guided isolation and further mechanistic studies are underway to identify potential chemical constituents responsible for the selective cytotoxic activities against ER- breast cancer cells.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3128.

Topography-guided treatment of decentered laser ablation using LaserSight's excimer laser

PURPOSE

To assess the efficacy of topography-guided laser ablation for correction of previously decentered laser ablation using LaserSight's excimer laser.

METHODS

Re-treatment was performed to correct decentered ablation using LaserSight's excimer laser for 18 patients who previously underwent LASIK surgery for myopia correction in both eyes. For each patient, only the decentered eye was re-treated while the other asymptomatic eye forms a control group for this study. Measurements were conducted on ablation center, best spectacle-corrected visual acuity (BSCVA), contrast sensitivity and corneal aberrations pre- and post-operatively.

RESULTS

For the retreated 18 eyes, the mean decentration was significantly reduced from 1.32+/-0.28mm to 0.61+/-0.23mm post-operatively (t=16.24, p<0.001), and with a significant improvement in mean BSCVA from 0.08+/-0.09 logMAR to 0.01+/-0.11 logMAR (t=4.58, p<0.001). The post-operative contrast sensitivity at the spatial frequencies (SF) of 1.00 and 0.70 was significantly improved (p<0.05 for both SFs). Corneal higher-order aberrations (HOAs), including the coma-like aberrations and spherical aberration, were decreased. In comparing the measurements for the retreated group to those for the control group, no significant differencewas found either in decentration or in BSCVA, but the contrast sensitivity at 0.70 was lower and the level of corneal aberrations was higher.

CONCLUSIONS

Topography-guided ablation with LaserSight excimer laser is effective to correct decentered ablation. However, the re-treated eye is still inferior to the eye with originally centered ablation in corneal optical quality or visual performance.

Industry funding and the reporting quality of large long-term weight loss trials

BACKGROUND

Quality of reporting (QR) in industry-funded research is a concern of the scientific community. Greater scrutiny of industry-sponsored research reporting has been suggested, although differences in QR by sponsorship type have not been evaluated in weight loss interventions.

OBJECTIVE

To evaluate the association of funding source and QR of long-term obesity randomized clinical trials (RCT).

METHODS

We analysed papers that reported long-term weight loss trials. Articles were obtained through searches of Medline, HealthStar, and the Cochrane Controlled Trials Register between the years 1966 and 2003. QR scores were determined for each study based upon expanded criteria from the Consolidated Standards for Reporting Trials (CONSORT) checklist for a maximum score of 44 points. Studies were coded by category of industry support (0=no industry support, 1=industry support, 2=in kind contribution from industry and 3=duality of interest reported). Individual CONSORT reporting criteria were tabulated by funding type. An independent samples t-test compared the differences in QR scores by funding source and the Wilcox-Mann-Whitney test and generalised estimating equations (GEE) were used for sensitivity analyses.

RESULTS

Of the 63 RCTs evaluated, 67% were industry-supported trials. Industry funding was associated with higher QR score in long-term weight loss trials compared with nonindustry-funded studies (mean QR (s.d.): industry=27.9 (4.1), nonindustry=23.4 (4.1); P<0.0005). The Wilcox-Mann-Whitney test confirmed this result (P<0.0005). Controlling for the year of publication and whether the paper was published before the CONSORT statement was released in the GEE regression analysis, the direction and magnitude of effect were similar and statistically significant (P=0.035). Of the individual criteria that prior research has associated with biases, industry funding was associated with greater reporting of intent-to-treat analysis (P=0.0158), but was not different from nonindustry studies in reporting of treatment allocation and blinding.

CONCLUSION

Our findings suggest that the efforts to improve reporting quality be directed to all obesity RCTs, irrespective of funding source.

A phase I study of clofarabine in combination with cyclophosphamide and etoposide: A new regimen in pediatric patients with refractory or relapsed acute leukemia

9529

Background: Clofarabine is a promising new agent in the treatment of childhood leukemia as evidenced by single agent activity in previous phase I and II studies. We conducted a pilot phase I study of clofarabine used in combination with cyclophosphamide and etoposide to determine the maximum tolerated dose (MTD) and dose limiting toxicities (DLT). Methods: Patients between 1 and 21 years old with relapsed or refractory acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML) were enrolled. A standard 3+3 design was followed to determine the safe dose when used in combination. All drugs were administered by IV infusion daily for 5 consecutive days in induction and 4 days in consolidation. Patients received up to 2 induction cycles depending on the response, followed by consolidation cycles (maximum of 8 total cycles). The initial doses (cohort 1) were as follows: clofarabine: 20 mg/m2/day, etoposide 75 mg/m2/day and cyclophosphamide 340 mg/m2/day. Once etoposide and cyclophosphamide were escalated to their target dose (100 mg/m2/day and 440 mg/m2/day respectively in cohort 3), clofarabine was then increased to 30 mg/m2/day in cohorts 4 and would be increased to 40 mg/m2/day in cohort 5. Results: Thirteen patients (10 ALL; 3 AML) were enrolled in the first 4 dose cohorts to this date. The median number of prior regimens was 2. Response data (based on investigator assessment) are available for the first 8 patients: 6 patients (including 1 patient with AML) achieved either complete remission (CR) or complete remission without platelet recovery (CRp), for an overall response rate of 75%. Four patients proceeded to HSCT. One patient in cohort 4 experienced a DLT which resolved (grade 3 elevation of lipase) and possible veno-occlusive disease leading to cohort expansion. Common toxicities noted include febrile neutropenia and fever. Conclusions: The phase I study is ongoing until determination of MTD for this combination but these early results indicate that this combination shows significant activity in children with refractory or relapsed acute leukemias and is well-tolerated.

No significant financial relationships to disclose.

What is the quality of reporting in weight loss intervention studies? A systematic review of randomized controlled trials

BACKGROUND

Despite the large number of randomized controlled trials (RCTs) assessing weight loss interventions, no study has assessed the quality of reporting in these trials.

PURPOSE

To assess the quality of reporting of RCTs of weight loss interventions and to identify predictors of reporting quality.

METHODS

The RCTs assessed were derived from a published systematic review of trials investigating the efficacy of weight loss interventions. For our study, two reviewers independently rated the quality of reporting in these trials, based on the Consolidated Standards for Reporting of Trials (CONSORT) Statement. We describe the quality of reporting using number (percent) of studies satisfying each of the 44 CONSORT criteria. We use generalized estimating equations (GEE) to fit a multivariable regression model to determine factors that are associated with the overall quality reporting score.

RESULTS

We assessed 63 RCTs, of which 25 were dietary-lifestyle trials, 22 were pharmacological trials and 16 were behavior-cognitive, exercise-lifestyle, or surgical trials. Less than half (46%) of the trials defined the primary outcome of the study; about 10% provided the description of the method of allocation concealment. Multivariable GEE results showed that the sample size, type of intervention (non-pharmacologic trials having lower scores than pharmacologic trials), and publication time relative to the CONSORT Statement publication in 1996 (publications after 1996 having higher scores) were strong predictors of the quality reporting score. Reporting a statistically significant result on the primary outcome was not significantly associated with the quality score.

CONCLUSION

While the overall quality in reporting seemed to have improved since the publication of the revised CONSORT Statement in 1996, the reporting of some key methodologic aspects, such as clear description of primary outcome and method of allocation concealment, still requires improvements. Factors that are significantly associated with the overall quality reporting score can be used as surrogates in the review of protocols to enhance the quality of the final reports.

Delayed cerebrovascular complications of intrathecal colloidal gold

OBJECTIVE

Therapy with intrathecal colloidal gold has been used in the past as an adjunct in the treatment of childhood neoplasms, including medulloblastoma and leukemia. We describe the long-term follow-up period of a series of patients treated with intrathecal colloidal gold and emphasize the high incidence of delayed cerebrovascular complications and their management.

METHODS

Between 1967 and 1970, 14 children with posterior fossa medulloblastoma underwent treatment at the University of Minnesota. Treatment consisted of surgical resection, external beam radiotherapy, and intrathecal colloidal gold. All patients underwent long-term follow-up periods.

RESULTS

Of the 14 original patients, 6 died within 2 years of treatment; all experienced persistent or recurrent disease. The eight surviving patients developed significant neurovascular complications 5 to 20 years after treatment. Three patients died as a result of aneurysmal subarachnoid hemorrhage, and five developed ischemic symptoms from severe vasculopathy that resembled moyamoya disease.

CONCLUSION

Although therapy with colloidal gold resulted in long-term survival in a number of cases of childhood medulloblastoma, our experience suggests that the severe cerebrovascular side effects fail to justify its use. The unique complications associated with colloidal gold therapy, as well as the management of these complications, are presented. We recommend routine screening of any long-term survivors to exclude the presence of an intracranial aneurysm and to document the possibility of moyamoya syndrome.