Dip-pen nanolithography: controlling surface architecture on the sub-100 nanometer length scale

A new method for patterning surfaces with organic structures, termed "dip-pen" nanolithography (DPN), has been developed. DPN allows one to deliver collections of molecules to a surface in a positive printing mode. The technique offers 15 nm linewidths and 5 nm spatial resolution. Current capabilities and future applications of DPN are discussed.

Effect of adjuvant chemotherapy on bone resorption marker beta C-telopeptide (B-CTX) in postmenopausal women

594

Background: In NCIC CTG MA.14, a randomized trial of tamoxifen versus tamoxifen + octreotide LAR, we found a measure of bone resorption, serum B-CTx, to be significantly associated with bone-only first recurrence. Administration of chemotherapy was permitted, and chemotherapy was a stratification factor (never, concurrent, sequential). It was unclear whether pretrial B-CTx serum levels would be affected by prior administration of chemotherapy, and whether timing of chemotherapy was associated with who had bone only, or bone and other site relapse. Methods: Serum B-CTx concentration (Serum CrossLaps Nordic Biosciences, Copenhagen, DN) was determined pretrial therapy in 621 of 667 primary breast cancer patients on MA.14. We tested for differences in continuous B-CTx levels in those who had assessment before (any) chemotherapy (included those who had none) versus those who were assessed after chemotherapy with an ANOVA test. We also used exact Fisher tests to examine whether there was an association between timing of (any) chemotherapy and 1) B-CTx values in upper 2.5% range for healthy pre-menopausal women; 2) bone only recurrence; and 3) concurrent bone and other relapse. Results: Serum B-CTx was assessed before (any) chemotherapy on 382/621 (61.5%) of patients, and after chemotherapy on 239/621 (38.5%). There were no significant differences in serum B-CTx values (p = 0.27). We found 92/621 (14.8%) of patients had high serum B-CTx levels compared with healthy pre-menopausal women; similar proportions of these women received chemotherapy after B-CTx assessment (p = 0.42). Furthermore, there were no differences in timing of (any) chemotherapy and those who had bone only recurrence (p = 0.48) or bone and other type of relapse (p = 0.76). Conclusions: Chemotherapy in the adjuvant setting had no significant effect on bone resorption marker B-CTX serum levels.

No significant financial relationships to disclose.

Correlation of plasma levels of free insulin-like growth factor 1 and clinical benefit of the IGF-IR inhibitor figitumumab (CP- 751, 871)

3539

Background: Free IGF-1 (fIGF-1) represents the biologically active fraction of IGF-1, the main circulating ligand of the Insulin-like Growth Factor type I Receptor (IGF-IR). Signaling through the IGF-IR induces tumor survival and resistance to cancer therapy. Figitumumab (F) (CP-751,871) inhibits IGF-1-induced IGF-IR autophosphorylation with an IC50 of 0.42 nmol/L. Methods: Plasma levels of fIGF-1 were measured in a phase 1b/2 multi-center study of Paclitaxel (T) and Carboplatin (C) and F in patients (pts) with treatment-naïve NSCLC. Other serum markers of the IGF-IR pathway, including circulating soluble IGF-IR (sIGF-IR), IGFBP3 and ALS (acid-labile subunit), were also investigated. The Kaplan-Meier method was used to estimate median survival times. Results: A total of 536 blood samples from 159 pts were analyzed. Baseline median and range fIGF-1 were 0.53 and 0.07–1.99 ng/mL. fIGF-1 directly correlated with IGFBP3 and ALS, and inversely with sIGF-IR (Rho=-0.430, p=0.03). Treatment with F resulted in dose-dependent accumulation of fIGF-1 with a sustained >10 fold increase in fIGF-1 plasma levels at the 20 mg/kg dose, suggesting complete systemic blockade of fIGF-1 binding to the IGF-IR. sIGF-IR decreased and IGFBP3 increased in response to F, but increases in IGBP3 were more modest than those of fIGF-1. Baseline plasma levels of fIGF-1 had a 96.6% negative predictive value for PFS status at 6 months (p=0.03). Median PFS were respectively 2.73 and 6.53 months for TC alone and TC with F (20 mg/kg) in the high fIGF-1 group (p=0.001) while no significant treatment effect of F was observed in the low (<0.54 ng/mL) fIGF-1 group. Sixty three percent of pts with high fIGF-1 had tumors of adenocarcinoma histology. Conclusions: IGF-1 is a key element in the biology of NSCLC of adenocarcinoma histology and its determination may contribute to the identification of pts who benefit from figitumumab therapy.

[Table: see text]

Elevated plasma endoglin (CD105) predicts decreased response and survival in a metastatic breast cancer trial of hormone therapy

Background Endoglin (CD105) is a co-receptor for TGF-beta, is expressed by human vascular endothelial cells, and plays a major role in angiogenesis. Materials and methods Pretreatment EDTA plasma from 224 metastatic breast cancer patients enrolled in a phase III 2nd-line hormone therapy trial and 50 control subjects were assayed for endoglin using an ELISA. Results The female control group (n = 50) plasma endoglin upper limit of normal was defined as the mean + 2 SD (8.7 ng/ml). The breast cancer patient plasma endoglin was 6.40 +/- 2.23 ng/ml (range 3.00-19.79 ng/ml). Elevated plasma endoglin levels were detected in 26 of 224 patients (11.6%). Patients with elevated plasma endoglin had a reduced clinical benefit rate (CR + PR + Stable) (15 vs. 42%) (P = 0.01) to hormone therapy. TTP was shorter for patients with elevated plasma endoglin, but did not reach statistical significance (P = 0.2). Patients with elevated plasma endoglin had decreased overall survival (median 645 vs. 947 days) (P = 0.005). Conclusion Elevated pretreatment plasma endoglin levels predicted for decreased clinical benefit and a shorter overall survival in metastatic breast cancer patients treated with 2nd-line hormone therapy.

Pharmacodynamic properties of the anti-IGF-IR monoclonal antibody CP-751,871 in cancer patients

3587

Background: The Insulin like Growth Factor I receptor (IGF-IR), a tyrosine kinase, is widely expressed in human tissues. IGF- IR and its ligands (IGF-I and IGF-II) are expressed by many human cancers (e.g., breast, prostate, colorectal and non-small cell lung). Binding of the ligands to the IGF-IR activates key cellular signaling pathways important for stimulating cellular proliferation and inhibiting apoptosis. IGF- I and IGF-II are present in the circulation, but also locally expressed in neoplastic tissue. Bioavailability of these ligands is regulated by a family of IGF binding proteins (IGFBPs1–6). CP-751,871, a fully human monoclonal antibody, is a highly specific and potent inhibitor of IGF-IR activation. In vitro experiments show that binding of CP 751,871 to IGF-IR induces receptor internalization and degradation. This antibody has been shown to have antineoplastic activity using both in vivo and in vitro pre-clinical models. Methods: Blood samples were collected for characterization of the pharmacokinetic and pharmacodynamic properties of CP-751,871 in phase 1 trials of this agent given to cancer patients either alone or in combination with chemotherapy. The endpoints assessed included among others: CP-751,871 plasma concentrations, total and free IGF-I, IGFBP-3, soluble IGF-IR and IGF-IR expression on granulocytes and tumor cells. Results: CP 751,871 exposure increased with dose over the 800-fold dose range investigated. Pharmacokinetic profiles were consistent with target-mediated disposition. A dose-dependent downregulation of soluble IGF-IR serum concentration and IGF-IR expression was observed, with sustained inhibition for the entire dosing period (3–4 week cycles) observed at doses ≥ 1.5 mg/kg. As predicted for an agent that interferes with IGF-I action, IGF-I and IGFBP-3 serum levels were up-regulated in a similar dose-dependent manner. Conclusions: The pharmacodynamic endpoints of clinical trials provide evidence that CP-751,871 targets IGF-IR in granulocytes, tumor cells and tissues involved in regulation of the growth hormone -IGF-I axis. These data provide proof of principle for the use of CP-751,871 as a first-in-class therapeutic approach to inhibit the IGF-IR pathway in cancer patients.

No significant financial relationships to disclose.

Elevated serum M-CSF level predicts reduced survival in metastatic breast cancer patients

10591

Background: Macrophage colony stimulating factor (M-CSF) and its receptor (CSF-1R, the c-fms oncogene protein product) have been reported to be expressed in a variety of cancers, including breast cancer. The M-CSF produced by breast cancer cells and surrounding stromal cells increases osteoclast formation and maturation and enhances the expression of stromal RANK ligand, both of which increase osteolytic bone degradation. In this study we evaluated the predictive and prognostic potential of circulating M-CSF in metastatic breast cancer patients treated with hormone therapy. Methods: Using an M-CSF ELISA (R&D Systems, Minneapolis, MN), M-CSF concentration was determined in pretreatment sera from 204 metastatic breast cancer patients enrolled in a phase III 2nd-line hormone therapy trial of fadrozole vs. megace, and also in sera from 25 post-menopausal control female subjects. Results: The serum M-CSF level from the 25 healthy post-menopausal female control subjects had a mean ± SD of 835.6 ± 276.1 pg/ml (range 319.0 - 1,465.8 pg/ml). The upper limit of normal was defined as the 95th percentile of the serum M-CSF level from the female control group (1277 pg/ml). Pretreatment serum M-CSF levels from the metastatic breast cancer patients ranged from 82.2 - 3,019.8 pg/ml, and were found elevated above the upper limit of normal in 15 of 204 patients (7.35 %). Patients with elevated pretreatment serum M- CSF did not have a significantly different objective response rate, clinical benefit rate, or time to progression to hormone therapy; but these patients did have significantly reduced overall survival (median survival 10.0 months) compared to patients with normal serum M-CSF levels (median survival 24.3 months)(p = 0.007). In multivariate analysis with serum HER-2/neu included as a covariate, elevated serum M-CSF level remained a significant independent variable for reduced survival (p= 0.032). Conclusions: Pretreatment serum M-CSF levels were elevated in 7 % of metastatic breast cancer patients compared to healthy female control subjects, and these patients had significantly reduced overall survival. Serum M-CSF deserves further study to determine its predictive and prognostic biomarker potential in breast cancer patients.

No significant financial relationships to disclose.

Elevated plasma endoglin (CD105) predicts decreased response and survival in metastatic breast cancer patients

10091

Background: Endoglin (CD105) is a proliferation-associated surface protein expressed by human vascular endothelial cells. It is a co-receptor for transforming growth factor (TGF) -β1 and TGF-β3, and plays a major role in angiogenesis. Upregulation of endoglin has been reported in endothelial cells of breast and colorectal cancers, and elevated levels of serum endoglin have been associated with tumor metastasis in breast cancer patients. Materials and Methods: Pretreatment EDTA plasma from 224 metastatic breast cancer patients enrolled in a phase III 2nd-line hormone therapy trial and 50 healthy post-menopausal female controls were assayed for soluble endoglin using a double-antibody sandwich ELISA from R&D Systems (Minneapolis, MN). Results: In the post-menopausal female control group (n=50), the mean ± SD for plasma endoglin levels were 5.00 ± 1.84 ng/ml, with a range of 2.38–9.83 ng/ml. The upper limit of normal was defined as the mean + 2 SD (8.7 ng/ml) for plasma endoglin. In the breast cancer patient group, the mean ± SD for plasma endoglin was 6.40 ± 2.23 ng/ml, with a range of 3.00–19.79 ng/ml. Elevated plasma endoglin levels were detected in 26 of 224 patients (11.6%). Patients with elevated vs. normal plasma endoglin levels had a reduced clinical benefit rate (CR +PR+Stable)(15% vs. 42%)(p=0.01) to hormone therapy. Time to progression (TTP) was shorter for patients with elevated vs. normal plasma endoglin levels, but did not reach statistical significance (p=0.2). Patients with elevated plasma endoglin had decreased overall survival (median 645 days vs. 947 days)(p=0.005). Another plasma angiogenic marker, soluble Tie-2 receptor, did not significantly correlate with clinical outcome. A weak correlation existed between plasma endoglin and Tie-2 (r =.54, p<0.00001). There was no correlation between plasma endoglin levels and the presence of bone metastasis vs. other sites of metastases. Conclusions: Elevated pretreatment plasma endoglin levels predicted for decreased clinical benefit rate to 2nd-line hormone therapy and a shorter overall survival in metastatic breast cancer patients. Circulating endoglin levels deserve further study for monitoring anti-angiogenic therapy.

[Table: see text]

Elevated serum ras level predicts decreased survival in patients with hematologic malignancies

6562

Background: Ras is a GDP/GTP binding G protein that acts as a molecular switch converting signals from the cell membrane to the nucleus to regulate cell proliferation, differentiation, and protein synthesis. Activation of ras oncogenes has been identified in a variety of cancers, including 30% of acute myelogenous leukemia patients. The purpose of our study was to evaluate serum ras levels and correlate with survival in hematologic cancer patients. Methods: A novel ras p21 ELISA (Oncogene Science/Bayer Diagnostics, Cambridge, MA) employing two monoclonal antibodies reactive with H, K, and N ras was utilized to quantify total ras levels in serum obtained from patients with various hematologic malignancies including acute myelogenous leukemia (AML), acute lymphocytic leukemia (ALL), chronic myelogenous leukemia (CML), and chronic lymphocytic leukemia (CLL). Results: The total leukemia patient group consisted of 52 patients. At the 75th percentile serum ras cutpoint (524 pg/ml) 11/52 patients were defined as elevated for serum ras. From this patient group, 38 patients had clinical followup available and were included in the Kaplan-Meier analysis of overall survival. Patients with elevated serum ras (>524 pg/ml) had significantly shorter overall survival compared to those without (median OS 205 vs. 677 days) (p= 0.04). In a multivariate analysis including serum ras level and type of leukemia, serum ras level remained a significant independent variable for shorter overall survival (p=0.004). Within leukemia subtypes 2/18 AML, 4/9 CML, 3/7 ALL, and 0/4 CLL patients had elevated serum ras levels. Conclusions: Leukemia patients with elevated serum ras levels had a significantly shorter overall survival. Serum ras should be evaluated as a potential biomarker in larger leukemia trials, especially for response to treatment with inhibitors of the ras signaling pathway.

[Table: see text]

Serum carboxyterminal telopeptide (ICTP) as a prognostic marker in bone metastases (BM) treated with bisphosphonates

10107

Background: Biochemical markers of bone turnover, such as N- and C-terminal cross-linking telopeptide of type I collagen have been evaluated as prognostic matkers in patients with BM. In one of such study, we found that ICTP was not affected by bisphosphonate (BP) therapy (Costa, et al., JCO 2002; 20:850–856). In this prospective study we analyzed whether the baseline level of ICTP was predictive of skeletal related events (SREs) as defined by: pathologic fractures (PF), radiation to treat BM (RT) or spinal cord compression (SCC); time to progression (TTP) and overall survival (OS) in patients with BM from solid tumors under BP therapy. Methods: We studied 116 BM patients, median age: 64 years; 67% females; 61% breast cancer; 19% prostate cancer; and 20% other tumor types. The x-ray pattern of BM was lytic in 54% patients, blastic in 23%, and mixed in 21%. At the time of study entry, all patients had serum ICTP levels measured with RIA reagents from Orion Diagnostica (reference range: 2.5–4.0 μg/L). A serum ICTP cutoff of 6.2 μg/L was established using the mean + 2D. The occurrence of SREs was recorded during the study and an objective evaluation of BM status was performed every 4–6 months. During the time period on study, patients received treatment with IV zoledronate (57%), IV pamidronate (28%), or more than one BP. The proportional hazards model was used to investigate the correlation of ICTP baseline level with time to first SRE (TTSRE), TTP, and OS; and Poisson regression with the skeletal morbidity rate (SMR): number of SREs/person/year. Results: The median follow-up was 21 months. 81.9% patients had ICTP level above 6.2 μg/L and the mean value of ICTP was 15.1 (SD 11.9) μg/L. During the time period on study, 38% had PF, 57% had RT, and 9.5% had SCC. Median TTSRE was 20 months and the SMR was 0.84. Median TTP was 12 months and median OS time was 29 months. ICTP levels above 6.2 μg/L were associated with increased mortality risk (hazard ratio (HR) 2.86, 95%CI 1.37–6.00, p=0.005) and increased SMR (incidence rate ratio 1.88, 95%CI 0.98–3.60, p=0.057), but not with TTP (HR 1.18, 95%CI 0.67–2.07, p=0,57) or TTSRE (HR 1.59, 95%CI 0.82–3.08, p=0.17). Conclusions: Elevated serum ICTP levels is associated with decreased survival and increased incidence of SREs in BM patients on BP therapy.

No significant financial relationships to disclose.

Serum HER-2/neu and response to the aromatase inhibitor letrozole versus tamoxifen

PURPOSE

To determine the effect of elevated serum HER-2/neu on the response of metastatic breast cancer patients to an aromatase inhibitor versus an antiestrogen.

PATIENTS AND METHODS

Five hundred sixty-two estrogen receptor-positive metastatic breast cancer patients were randomized to first-line hormone therapy with either letrozole or tamoxifen. An automated enzyme-linked immunosorbent assay was used to detect serum HER-2/neu.

RESULTS

For patients with normal serum HER-2/neu (70.5%), objective response rate (ORR; 39% in letrozole-treated patients v 26% in tamoxifen-treated patients; P =.008), clinical benefit (CB; 57% v 45%; P =.016), time to progression (TTP; median, 12.2 v 8.5 months; P =.0019), and time to treatment failure (TTF; median, 11.6 v 6.2 months; P =.0066) were significantly better in patients treated with letrozole. In the elevated HER-2/neu group (29.5%), there was no significant difference in ORR (17% in letrozole-treated patients v 13% in tamoxifen-treated patients; P =.45) or CB (33% v 26%; P =.31), but there was a strong trend in favor of a longer TTP with letrozole (median, 6.1 v 3.3 months; P =.0596) and a significantly longer TTF with letrozole (median, 6.0 v 3.2 months; P =.0418). Multivariate analysis revealed that elevated serum HER-2/neu was a negative predictor for ORR and TTP.

CONCLUSION

Patients with normal serum HER-2/neu receiving letrozole demonstrated a significantly greater ORR and CB and longer TTP and TTF than patients receiving tamoxifen. Although in patients with elevated serum HER-2/neu there was no significant difference between letrozole and tamoxifen in ORR or CB, there was a strong trend favoring longer TTP and significantly longer TTF with letrozole.

Elevated serum Her-2/neu level predicts decreased response to hormone therapy in metastatic breast cancer

PURPOSE

To determine the effect of elevation of serum HER-2/neu on response to hormone therapy.

PATIENTS AND METHODS

Seven hundred nineteen metastatic patients with estrogen receptor-positive (ER(+)), progesterone receptor-positive, or both or ER status unknown breast cancer were randomized in three independent clinical trials to receive second-line hormone therapy with either megestrol acetate or an aromatase inhibitor (fadrozole or letrozole). An automated enzyme-linked immunosorbent assay specific for the extracellular domain of the HER-2/neu (c-erbB-2) oncoprotein product was used to detect serum levels.

RESULTS

Two hundred nineteen patients (30%) had elevated serum HER-2/neu protein levels, using the mean + 2 SD (15 ng/mL) from the serum of healthy women as an upper limit. Response to treatment was available for 711 patients. The response rate (complete responses plus partial responses plus stable disease) to endocrine therapy was 45% in 494 patients with non-elevated and 23% in 217 patients with elevated serum HER-2/neu levels (P <.0001). Median duration of treatment response (using the time to progression [TTP] variable for patients who responded) was shorter in the group with elevated serum HER-2/neu levels (11.7 months) compared with the patient group with non-elevated levels (17.4 months). TTP, time to treatment failure, and median survival (17.2 months v 29.6 months) were also significantly shorter in the patients with elevated serum HER-2/neu levels (P <.0001).

CONCLUSION

Patients with ER(+) and serum HER-2/neu-positive metastatic breast cancer are less likely to respond to hormone treatment and have a shorter duration of response than ER(+) and serum HER-2/neu-negative patients. Their survival duration is also shorter.

Reliability, validity, and applicability of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0) for adults with multiple sclerosis

PURPOSE

To investigate the measurement properties of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST 2.0) with respect to test-retest stability, alternate form reliability, construct validity and applicability.

METHOD

Data on satisfaction and quality of life impacts of mobility devices were obtained from 81 community-based adults with Multiple Sclerosis, using the QUEST 2.0 and the Psychosocial Impact of Assistive Devices Scale (PIADS). Subjects were assigned to four groups and a second QUEST 2.0 was administered one week later. Groups differed with respect to the format and the order in which alternate forms were presented. Measures of association were calculated between QUEST 2.0 and PIADS (n = 81) and between QUEST 2.0 alternate forms (n = 48). Respondents' reactions were considered.

RESULTS

The device subscale, services subscale, and total QUEST 2.0 scores achieved good test-retest stability (ICC 0.82, 0.82, 0.91). Alternate-form equivalence (ICC 0.89, 0.76, 0.91) was lower for services. The positive correlations between QUEST 2.0 and the three PIADS dimensions were fair to moderate for device and total QUEST 2.0 (r(p) 0.34 to 0.45) and fair with services (r(p) 0.27 to 0.30). The tool was positively received, with some restrictions for the services subscale.

CONCLUSIONS

These findings on the psychometric properties of the QUEST 2.0 reinforce the relevance of the device subscale as an important outcome measure for assistive technology MS users. Further assessment of the services subscale is needed.

Item analysis of the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST)

The Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST) is an outcomes assessment tool designed to measure satisfaction with assistive technology in a structured and standardized way. The purpose of this article is to present the results of an analysis of the 24 items comprising QUEST and to explain how a subset of items demonstrating optimal measurement performance was selected. The criteria against which the items were measured were general acceptability, content validity, contribution to internal consistency, test-retest stability, and sensitivity. The items that ranked best in terms of these measurement properties were submitted to factorial analysis in order to complete the item selection. The first series of analyses reduced the item pool approximately by half, and the second series of analyses led to the final selection of 12 items. Factor analysis results suggested a bidimensional structure of satisfaction with assistive technology related to the assistive technology device (eight items) and services (four items). The 12-item revised version that will result from this study should prove to be a reliable and valid instrument for measuring outcomes in the field of assistive technology.

S-adenosylmethionine decarboxylase overexpression reduces invasiveness and tumorigenicity in nude mice of MCF-7 breast cancer cells

To elucidate the role of S-adenosylmethionine decarboxylase (SAMDC) in breast cancer biology, we have generated SAMDC overexpressing MCF-7 breast cancer cells. SAMDC overexpression did not alter in a major way growth properties of MCF-7 cells in soft agar, either under basal conditions or in response to estrogen and antiestrogen administration. SAMDC-MCF-7 cells, on the other hand, exhibited a markedly reduced invasive ability in matrigel (p=0.013). Furthermore, they were less tumorigenic in nude mice. The odds for control clones to form tumors were 3.13 (C.1.1.2-8.2, p=0.0184) higher than those for SAMDC clones. The odds ratio were identical in the absence and in the presence of estradiol. In addition, the growth rate of established tumors was slower for SAMDC than for control clones. Overall, our results are consistent with the notion that these phenotypic changes induced by SAMDC overexpression are primarily mediated by suppression of cellular putrescine (and, possibly, spermidine) levels.

Use of markers of bone turnover for monitoring bone metastases and the response to therapy

Metastatic bone disease is a frequent complication of breast and other cancers, resulting in skeletal complications that are a significant cause of morbidity and mortality. Bone metastases can be difficult to diagnose radiologically and it can also be difficult to evaluate patients' response to treatment by using the methods that are currently available (radiography, bone scans, and computed axial tomography scans). These are relatively insensitive procedures, thus, there is a requirement for new methods for assessing bone response to ensure patients benefit from the optimum type and duration of treatment. Biochemical markers of bone turnover, such as N-telopeptide and the pyridinium cross-links pyridinoline and deoxypyridinoline, may provide information on bone dynamics that in turn may reflect disease activity in bone. Several studies have shown bone markers to be elevated in cancer patients who have documented evidence of metastatic bone disease. Increased levels are also observed in some patients without clinical evidence of bone metastases, when compared with normal subjects. Rises in such markers may be the first indication of bone involvement and therefore may potentially be useful in early diagnosis of progression. Preliminary data suggest bone marker level correlates with the extent of metastatic disease and the number of skeletal sites involved. Markers of bone turnover may be helpful in identifying those patients likely to respond to bisphosphonate treatment. Such markers are also potentially useful in monitoring the effectiveness of bisphosphonate therapy in the management of bone metastases, in both patients with metastatic breast disease and multiple myeloma.

Effect of alpha-difluoromethyl-ornithine on the expression and function of the epidermal growth factor receptor in human breast epithelial cells in culture

We have previously shown that ornithine decarboxylase (ODC) overexpression enhances the transforming effects of HER-2neu and epidermal growth factor (EGF) in normal MCF-10A human breast epithelial cells. Our data suggest that such potentiation may be mediated by activation of the mitogen-activated protein kinase (MAPK) pathway and, possibly, STAT signalling. To further explore the interaction between the polyamine pathway and EGF/HER-2neu signalling in this system, we inhibited endogenous ODC activity with alpha-difluoromethylornithine (DFMO) and assessed the effects of this blockade on the expression of EGF receptors (EGFR) and HER-2neu as well as activation of downstream EGF target genes. We found that DFMO administration to MCF-10A cells increased EGF-R mRNA and protein levels in a dose-response fashion, while HER-2neu expression was not affected. The effect of DFMO was mediated through polyamine depletion since it could be reversed by exogenous putrescine administration. Our results also indicated that the increase in EGFR induced by DFMO was not a non-specific consequence of inhibition of cell proliferation. The upregulated EGFRs were functional since they could be phosphorylated by EGF and they were able to promote phosphorylation of downstream signalling molecules including ERK, STAT-3, and STAT-5. We propose that physiologic levels of ODC activity may be critical for regulation of a yet undefined signalling pathway, whose blockade by DFMO leads to a compensatory increase in functional EGFR.

Key dimensions of client satisfaction with assistive technology: a cross-validation of a Canadian measure in The Netherlands

The purpose of this study was to conduct a cross-validation of the bidimensional structure of a satisfaction measure with assistive technology. Data were drawn from a follow-up study of 243 subjects who had been administered the Dutch version of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST). Ratings related to 12 satisfaction items were analysed. Factor analysis results showed that the underlying structure of satisfaction with assistive technology consists of two dimensions related to assistive technology, Device (eight items) and Services (four items), accounting for 40% of the common variance. This finding was consistent with a previous Canadian study and was interpreted as supporting the adequacy and stability of the QUEST measure of satisfaction. Although the structure is delineated, further studies are recommended to support its use in European countries.

Interrater reliability of the modified Jadad quality scale for systematic reviews of Alzheimer's disease drug trials

Drug therapies for Alzheimer's disease (AD) have been evaluated in clinical trials over the past 2 decades. Systematic reviews of AD drug trials can shed more light on the efficacy of pharmaceutical interventions. The modified Jadad scale can be used to assess the quality of trial reports that are candidates for inclusion in these systematic reviews. The interrater reliability of the modified Jadad scale was examined during such a review. Three blinded reviewers rated the quality of 42 AD drug trial reports: the intraclass correlation coefficient was 0.90. The modified Jadad scale appears to be a useful tool for AD research because of the very good interrater reliability. Also, it is composed of items that are well suited to the specific disease characteristics of AD. Further research should focus on the validity of this instrument.

Review of outcome measurement instruments in Alzheimer's disease drug trials: psychometric properties of global scales

The use of global outcome measures with strong psychometric properties in Alzheimer's disease (AD) drug trials is encouraged. This article focuses on Clinician Global Impression of Change scales, the Clinical Dementia Rating, and the Global Deterioration Scale to provide (1) a review of psychometric properties, (2) a critique of how these properties are assessed in the literature, and (3) a basis for evaluating, from the standpoint of psychometric properties, the appropriateness of using a given global scale in a drug trial. Reported reliability and validity estimates for the aforementioned scales range from fair to very good, but small sample sizes and/or inappropriate measures of correlation weaken the quality of the evidence. There is also a dearth of published information on responsiveness to change. Researchers planning AD drug trials should consider these issues, along with the interval between test administrations for test-retest reliability, to help select appropriate global outcome measurement instruments.

Review of outcome measurement instruments in Alzheimer's disease drug trials: introduction

This article introduces a four-part series on outcome scales used in Alzheimer's disease drug trials. First, it discusses the division of scales into four domains: cognition, functional ability/quality of life, behavior/mood, and global. Within each domain, the shortcomings of existing literature reviews are outlined, and the need for a more coherent view of the psychometric properties of the scales is emphasized. Second, the key concepts of reliability, validity, and responsiveness to change are defined and explained. This explanation also provides an overview of the statistical techniques used to assess measurement properties. Finally, the methods used to select the scales for review in the subsequent articles are explained, and each article is briefly introduced.

Review of outcome measurement instruments in Alzheimer's disease drug trials: psychometric properties of behavior and mood scales

This article reviews the reliability and validity of eight scales for behavior and mood problems that were identified in a comparative analysis of Alzheimer's disease (AD) drug trials. The scales are the Brief Psychiatric Rating Scale, the Alzheimer's Disease Assessment Scale-noncognitive, the Relative's Assessment of Global Symptomatology, the Consortium to Establish a Registry for Alzheimer's Disease-Behavior Rating Scale for Dementia, the Dementia Behavior Disturbance scale, the Neuropsychiatric Inventory, and two scales for depressive symptoms, the Cornell Scale for Depression in Dementia and the Dementia Mood Assessment Scale. This article also examines methodological limitations in the way the published literature has assessed the psychometric properties of these scales. The aim is to help clinicians and potential trial investigators select appropriate measurement instruments with which to assess behavior and mood problems in AD and to assist AD researchers in the evaluation of the psychometric properties of such scales.

Review of outcome measurement instruments in Alzheimer's disease drug trials: psychometric properties of functional and quality of life scales

The psychometric properties of functional and quality of life outcome measures that were used for the purpose of showing changes in antidementia drug trials for Alzheimer's disease are described and critiqued. The seven functional scales reviewed for reliability, validity, and responsiveness to change included the Geriatric Evaluation by Relative's Rating Instrument, the Physical Self-Maintenance Scale, the Instrumental Activities of Daily Living, the Blessed Dementia Scale, Part 1 and its revised version, the Interview for Deterioration in Daily Living with Dementia, the Unified Activities of Daily Living, and the Dependence Scale. The Progressive Deterioration Scale and Quality of Life Assessment were classified as quality of life scales. The majority of the scales were found to exhibit serious limitations, such as incomplete reliability and validity assessment for the intended uses. The most pervasive problem was a lack of data on responsiveness to change. It is recommended that further research be conducted to develop new tools or enhance existing measures for the assessment of both quality of life and functional ability.

Tissue-specific synthesis and oxidative metabolism of estrogens

Estrogen exposure represents the major known risk factor for development of breast cancer in women and is implicated in the development of prostate cancer in men. Human breast tissue has been shown to be a site of oxidative metabolism of estrogen due to the presence of specific cytochrome P450 enzymes. The oxidative metabolism of 17beta-estradiol (E2) to E2-3,4-quinone metabolites by an E2-4-hydroxylase in breast tissue provides a rational hypothesis to explain the mammary carcinogenic effects of estrogen in women because this metabolite is directly genotoxic and can undergo redox cycling to form genotoxic reactive oxygen species. In this chapter, evidence in support of this hypothesis and of the role of P4501B1 as the 4-hydroxylase expressed in human breast tissue is reviewed. However, the plausibility of this hypothesis has been questioned on the grounds that insufficient E2 is present in breast tissue to be converted to biologically significant amounts of metabolite. This critique is based on the assumption that plasma and tissue E2 levels are concordant. However, breast cancer tissue E2 levels are 10-fold to 50-fold higher in postmenopausal women than predicted from plasma levels. Consequently, factors must be present to alter breast tissue E2 levels independently of plasma concentrations. One such factor may be the local production of E2 in breast tissue through the enzyme aromatase, and the evidence supporting the expression of aromatase in breast tissue is also reviewed in this chapter. If correct, mutations or environmental factors enhancing aromatase activity might result in high tissue concentrations of E2 that would likely be sufficient to serve as substrates for CYP1B1, given its high affinity for E2. This concept, if verified experimentally, would provide plausibility to the hypothesis that sufficient E2 may be present in tissue for formation of catechol metabolites that are estrogenic and which, upon further oxidative metabolism, form genotoxic species at levels that may contribute to estrogen carcinogenesis.

[Utilization of lifting equipment and slings in occupational therapy]

The occupational therapist is frequently involved in the allocation process of lifting devices for clients with severe physical disabilities who are living in the community. The aim of this paper is to introduce a conceptual framework to help therapists prescribe lifting devices, including the slings. First, factors influencing the decision to prescribe such an aid are analysed based on the concepts of the Canadian Model of Occupational Performance (Canadian Association of Occupational Therapists, 1997). When working with clients toward maximizing their transfer skills, occupational therapists will take into account different aspects such as the characteristics of the client, the environment and the equipment, as well as the time allocated to complete the activity. Secondly, the notion of the work situation outlined by an organization specializing in work safety measures is used as a guide for transfer evaluation. From this viewpoint, the introduction of the lifting device occurs along a continuum of progressive loss of independence and is determined by degrees of personal independence, human assistance as well as technical assistance required to perform transfers. Finally, advantages and disadvantages of using lifting devices in a home setting are presented as a conclusion to the study.

Markers of bone resorption in patients treated with pamidronate

Pyridinoline (PYD), deoxypyridinoline (DPD), and N-telopeptide (NTX) are markers of bone resorption. In cancer patients with bone metastases, NTX is more often elevated than either of the pyridinolines. Bisphosphonates inhibit osteoclasts and their treatment decreases skeletal complications of malignancy. The aim of this study was to correlate urinary PYD, DPD, and NTX levels with clinical events in patients receiving pamidronate. 25 cancer patients with lytic bone disease were treated with monthly pamidronate combined with endocrine or chemotherapy; 27 others were on placebo. Twenty-four hour urines were collected at baseline, 1, 3 and 6 months. NTX values were determined by enzyme-linked immunosorbent assay (ELISA); PYD and DPD values were determined by reverse phase high performance liquid chromatography (HPLC). Two hour urines were also collected weekly for 21 patients. The greatest difference as a result of pamidronate treatment was observed in NTX values. Maximum suppression was achieved 2 weeks after treatment. Of the 25 patients who received pamidronate, 21 had initially elevated NTX values. 12 of the 21 finished with normal NTX values, whilst 9/21 had NTX values which remained abnormally elevated. The proportions of patients with fractures between these two subgroups approached statistical significance (P = 0.07) while the proportions with bony disease progression were significant (P = 0.03, Fisher's exact test). Measuring NTX levels appears useful in monitoring bisphosphonate therapy of bone metastases. The goal of treatment should be to normalise NTX excretion.

Diversity of pubertal testosterone changes in boys with constitutional delay in growth and/or adolescence

In a group of 22 boys with constitutional delay in growth and/or adolescence, intermittent testosterone enanthate treatment was employed in a randomized clinical trial at multiple doses ranging from 25-100 mg every two weeks for three month periods extending over 15-21 months. Twelve of the patients displayed a prompt increase in endogenous testosterone levels during the study period, reaching levels in the adult male range (> 250 ng/dl). The remaining 10 boys showed sluggish changes in endogenous testosterone during the investigation, ranging from 35-177 ng/dl. The bone ages and testicular sizes of the two groups at study initiation did not differ though urine LH was significantly less at study entry in the slowly maturing group. The data reveal a great diversity in the pace and pattern of endogenous testosterone changes in the study population. The results also suggest that exogenous sex steroid treatment of such patients does not speed up the central nervous system processes controlling the onset and progression of puberty. Boys with delayed puberty should be followed until endogenous testosterone levels reach the adult male range in order to rule out mild gonadotropin deficits.

Induction of a less aggressive breast cancer phenotype by protein kinase C-alpha and -beta overexpression

To address the isoenzyme-specific involvement of protein kinase C (PKC) in breast cancer biology, hormone-responsive MCF-7 breast cancer cells were infected with either PKC-alpha or -beta 1 cDNAs subcloned in the retroviral expression vector pMV7. Several stable clones of PKC-overexpressing cells were generated. Western analysis revealed cross-regulation between the alpha and beta isoforms, because induction of overexpression of one up-regulated the other. Overexpression of the alpha and beta isoenzymes, on the other hand, did not affect the already high endogenous expression of the novel delta, epsilon, eta, and zeta isoforms. Compared with control clones, PKC-alpha- and -beta-overexpressing MCF-7 cells exhibited more drastic morphological changes in response to phorbol 12-myristate 13-acetate administration characterized by cellular flattening and vacuolization. More importantly, induction of PKC-alpha and -beta overexpression induced a less aggressive biological behavior, which was characterized by reduced in vitro invasiveness and markedly diminished tumor formation and growth in nude mice. These in vivo findings can probably best be explained by the dramatic down-regulation of estrogen receptor levels observed in tumors derived from PKC-alpha-infected MCF-7 cells. Our data clearly show that it is possible to induce a less aggressive breast cancer phenotype by altering PKC isoenzyme expression.

Serial serum c-erbB-2 levels in patients with breast carcinoma

BACKGROUND

Recently, the extracellular domain of the c-erbB-2 oncogene product (HER-2/neu) has been reported to be elevated in the serum of one-fourth of patients with metastatic breast carcinoma. The role of serum c-erbB-2 as a tumor marker, however, is still poorly defined. The purpose of this study was to evaluate the utility of serial serum c-erbB-2 levels as a tumor marker in patients with metastatic breast carcinoma.

METHODS

c-erbB-2 levels in the sera of patients with breast carcinoma were determined by an enzyme immunoassay that detects the extracellular domain of c-erbB-2. Serum c-erbB-2 levels were evaluated prior to treatment as well as throughout the course of treatment with second-line hormonal therapy employing either megestrol acetate or fadrozole, an experimental aromatase inhibitor.

RESULTS

Fifty-eight of 300 patients (19.3%) had elevated pretreatment serum c-erbB-2 levels. Of these 58 patients with elevated pretreatment c-erbB-2, 48 had more than 1 visit which enabled us to quantitate serial c-erbB-2 levels throughout the course of treatment. Of these 48 patients, 28 (58.3%) had serial c-erbB-2 values that correlated with the clinical course.

CONCLUSIONS

Serial serum c-erbB-2 levels did not show a high overall correlation with the clinical course in this group of patients with metastatic breast carcinoma treated with second-line hormonal therapy.

Development of the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST)

This study's purpose was to develop a clinical instrument designed to evaluate user satisfaction with assistive technology devices. This paper describes the methodology used to develop the instrument entitled the Quebec User Evaluation of Satisfaction with assistive Technology (QUEST). Based on the theoretical and practical foundations of assistive technology as well as on the concept of satisfaction, preliminary versions of the instrument were created and examined by a panel of team participants. After the panel's recommendations were incorporated, a pretest of the revised instrument was conducted and the final French version of QUEST emerged. The originality of QUEST lies in its inter-activeness and user-directed approach to assessing satisfaction with assistive technology. From a set of 27 variables, the user is asked to indicate the degree of importance he/she attributes to each of the satisfaction variables and then to rate his/her degree of satisfaction with each of the variables considered (quite or very) important. While QUEST remains a clinical instrument undergoing pilot testing, it holds much promise in our quest for a reliable and valid means of assessing assistive technology outcome from the user's perspective.

Isolation and characterization of human breast cancer cells overexpressing S-adenosylmethionine decarboxylase

We report the first successful isolation and initial characterization of S-adenosylmethionine decarboxylase (SAMDC)-overexpressing cells using a transfection approach. Stably transfected MCF-7 breast cancer overproducing SAMDC (approximately 5-fold) manifested reduced ornithine decarboxylase while levels of N'-spermidine/spermine acetyltransferase were variably increased. Analysis of cellular polyamine profile showed that spermine was selectively increased (approximately 80%), while spermidine and putrescine levels were reduced (approximately 48% and approximately 15% of control, respectively). Since SAMDC-overexpressing clones exhibited increased clonogenicity in soft agar, our data suggest that spermine may be selectively involved in conferring a more invasive phenotype to breast cancer cells.

Biochemical and growth-modulatory effects of the new S-adenosylmethionine decarboxylase inhibitor CGP 48664 in malignant and immortalized normal human breast epithelial cells in culture

CGP 48664 [4-aminoindanon-1-(2'-amidino)hydrazone dihydrochloride monohydrate] is a newly introduced inhibitor of S-adenosylmethionine decarboxylase (SAMDC) with increased selectivity of action and reduced toxicity. We analyzed the biochemical and antiproliferative effects of this compound in a panel of hormone-dependent (3 clones of MCF-7, T47D) and -independent (MDA-MB-231, BT-20) human breast cancer cell lines in culture. For comparison, we also tested its effects in the spontaneously immortalized human breast epithelial cell line MCF-10A. All cell lines were highly sensitive to the growth-inhibitor effect of CGP 48664 with an IC50 between 0.1 and 0.5 microM. A dose-dependent bell-shaped increase in SAMDC was observed in normal and malignant breast cells resulting from enzyme stabilization by the inhibitor as supported by Western blot analysis. While ornithine decarboxylase (ODC) activity consistently increased, the effect of CGP 48664 on spermidine/spermine N'acetyltransferase (SSAT) was variable in the breast cancer cell lines. In contrast, the inhibitor consistently reduced SSAT activity level in the MCF-10A cell line and its derivative partially transformed by a mutated ras oncogene. As expected cellular putrescine levels were markedly increased by CGP 48664 administration, whereas spermidine and spermine contents were reduced. However, the degree of reduction was usually only moderate. Furthermore, exogenous polyamine administration was relatively ineffective in rescuing the antiproliferative effect of CGP 48664 in MCF-7 cells, while exerting a more complete rescue in the MDA-MB-231 cell line. We conclude that CGP 48664 exerts a potent growth-inhibitory effect on mammary cells in culture. However, its action may not always be entirely mediated through the polyamine pathway.

ARIMIDEX: a new oral, once-a-day aromatase inhibitor

ARIMIDEX is a potent and selective aromatase inhibitor undergoing evaluation as a treatment for postmenopausal women with advanced breast cancer. Studies examining the pharmacology of ARIMIDEX were conducted in both animals and humans. In animals, ARIMIDEX elicits maximal aromatase suppressive activity at a dose of approx. 0.1 mg/kg, does not alter adrenal steroid hormone biosynthesis, and at a dose of 1 mg/kg, has no other pharmacologic effects other than aromatase inhibition. In this overview, the pharmacodynamic, pharmacokinetic, and safety profiles of single and multiple daily doses of ARIMIDEX are reported in humans. Daily doses of 1-10 mg of ARIMIDEX suppressed estradiol levels to the maximum degree measurable using sensitive estrogen assays. ARIMIDEX had no clinically significant effects on the response of cortisol and aldosterone to ACTH stimulation. Absorption of ARIMIDEX was rapid, with maximum plasma concentrations occurring within 2 h after oral administration. Plasma concentrations of ARIMIDEX rose with increasing doses of the drug. The elimination half-life of ARIMIDEX in humans ranged from 30 to 60 h. Consistent with the long plasma half-life, steady state plasma concentrations were 3-4-fold higher than plasma concentrations observed after single administration of 1, 3, 5, or 10 mg doses. Long term treatment of breast cancer patients with 10 mg/day has continued in 17 patients without an escape of estradiol suppression. Previously, these patients had received on average 2.6 systemic treatments for breast cancer and had significant metastatic disease. Three of the 17 patients continued ARIMIDEX treatment for 20 months and beyond. Given the number of previous treatments and tumor burden at the start of treatment, the response to ARIMIDEX treatment is encouraging. Phase III studies are now underway to assess the efficacy and safety of ARIMIDEX in the treatment of advanced breast cancer.