The isolation and characterization of a telomerase immortalized goat trophoblast cell line

Trophoblast cells play vital roles in the processes of embryonic implantation and placentation. Many toxicological compounds can induce the malfunction of trophoblast cells, resulting in implantation failure or early embryonic loss. The finite lifespan of primary trophoblast cells limits investigation of the long-term effects of some toxicological compounds on trophoblast cells in vitro. In this study, primary goat trophoblast cells were purified by density gradient centrifugation and specific immuno-affinity purification. Then, the purified cells were immortalized through transfection of a plasmid containing the human telomerase reverse transcriptase (hTERT) gene. hTERT-transfected goat trophoblast cells (hTERT-GTCs) could steadily express hTERT gene and exhibit higher telomerase activity, and persistently proliferate without any signs of senescence up to 50 passages. The immortalized goat trophoblast cells still possessed the basic and key properties of normal primary goat trophoblast cells to express the specific intracellular marker cytokeratin 7 (CK-7) and secrete chorionic gonadotrophin β-subunit (CG-β) and placental lactogen (PL). Further studies showed that the immortalized goat trophoblast cells expressed vimentin and non-classical MHC class I antigen and exhibited invasive phenotype, suggesting that the immortalized goat trophoblasts resembled human extravillous trophoblasts. In addition, this cell line did not show neoplastic transformation either in vivo or in vitro. We concluded the immortalized goat trophoblast cells by hTERT transfection retained the basic and key characteristics of primary trophoblast cells and may provide a useful model to study the effects of some toxicological compounds on trophoblast cells.

Association between copy number variations of HLA-DQA1 and ankylosing spondylitis in the Chinese Han population

Ankylosing spondylitis (AS) is a chronic inflammatory disease with complex genetic traits. Multiple sequence variations have been associated with AS, but explained only a proportion of heritability. The studies herein aimed to explore potential associations between genomic copy number variation (CNV) and AS of Han Chinese. Five AS patients were examined with the high-density comparative genomic hybridization (CGH) microarrays in the first screen test for AS associated CNVs. A total of 533 AS patients and 792 unrelated controls were examined in confirmation studies with the AccuCopy assays. A significant association was observed between the CNV of the HLA-DQA1 and AS. Comparing with controls, AS patients showed an aberrant copy number (CN), and significantly increased number of patients had more than 2 copies of the HLA-DQA1. Therefore, CNV of the HLA-DQA1 may play an important role in susceptibility to AS in Han Chinese population.

Commissioning dose computation models for spot scanning proton beams in water for a commercially available treatment planning system

PURPOSE

To present our method and experience in commissioning dose models in water for spot scanning proton therapy in a commercial treatment planning system (TPS).

METHODS

The input data required by the TPS included in-air transverse profiles and integral depth doses (IDDs). All input data were obtained from Monte Carlo (MC) simulations that had been validated by measurements. MC-generated IDDs were converted to units of Gy mm(2)/MU using the measured IDDs at a depth of 2 cm employing the largest commercially available parallel-plate ionization chamber. The sensitive area of the chamber was insufficient to fully encompass the entire lateral dose deposited at depth by a pencil beam (spot). To correct for the detector size, correction factors as a function of proton energy were defined and determined using MC. The fluence of individual spots was initially modeled as a single Gaussian (SG) function and later as a double Gaussian (DG) function. The DG fluence model was introduced to account for the spot fluence due to contributions of large angle scattering from the devices within the scanning nozzle, especially from the spot profile monitor. To validate the DG fluence model, we compared calculations and measurements, including doses at the center of spread out Bragg peaks (SOBPs) as a function of nominal field size, range, and SOBP width, lateral dose profiles, and depth doses for different widths of SOBP. Dose models were validated extensively with patient treatment field-specific measurements.

RESULTS

We demonstrated that the DG fluence model is necessary for predicting the field size dependence of dose distributions. With this model, the calculated doses at the center of SOBPs as a function of nominal field size, range, and SOBP width, lateral dose profiles and depth doses for rectangular target volumes agreed well with respective measured values. With the DG fluence model for our scanning proton beam line, we successfully treated more than 500 patients from March 2010 through June 2012 with acceptable agreement between TPS calculated and measured dose distributions. However, the current dose model still has limitations in predicting field size dependence of doses at some intermediate depths of proton beams with high energies.

CONCLUSIONS

We have commissioned a DG fluence model for clinical use. It is demonstrated that the DG fluence model is significantly more accurate than the SG fluence model. However, some deficiencies in modeling the low-dose envelope in the current dose algorithm still exist. Further improvements to the current dose algorithm are needed. The method presented here should be useful for commissioning pencil beam dose algorithms in new versions of TPS in the future.

[Residues affecting hydrolysis of soy isoflavone glycosides, stability and catalytic properties of Thermotoga maritime β-glucosidase]

The thermostable β-glucosidase A (TmBglA) from Thermotoga maritime is a promising biocatalyst for production of isoflavone aglycones. Use of enzymes with high specificity for soy isoflavone conjugates is however essential for efficient hydrolysis. The effect of the amino acids located in the aglycone binding pocket with non-conserved residues between specificity groups in family 1 glycoside hydrolase (GH1) was studied using wild-type TmBglA and 3 exchange mutants (MI-TmBglA, M2-TmBglA, M1M2-TmBglA). Three mutants were expressed in Escherichia coli, purified and characterized. They had shifts in both optimum tem- perature and thermal stability, and their narrowing pH-activity curve caused by removing the ionized side chain in mutation. All mutants demonstrated the decreased catalytic efficiency more effectively revealed with natural glycoside, salicin, than with artificial substrate, p-nitrophenyl-β-D-glucopyranoside, suggesting that' these amino acids are the key residues to determine aglycone specificity. A lower hydrolysis of genistin and daidzin for M2-TmBglA than M1-TmBglA indicated that L400, A407 and E408 being preferable to V170, A171, V173, G 174 and H180 residues of Tm-BglA could be essential for soy isoflavone glycoside binding and catalysis.

Orientation and Phase Analysis of Nanoscale Grains Using Transmission Electron Microscopy

The nanostructuring of materials is a process which enables their properties to be drastically changed as compared to their coarse crystalline condition. For example, peculiar features were achieved, e.g. extremely high yield and ultimate strengths. The structure of such nanoscale materials has not been characterized yet in detail as compared to materials of a coarser crystalline structure because an appropriate analytical technique did not exist. Nano beam diffraction (NBD) by transmission electron microscopy (TEM) makes possible a local resolution up to 1 nm and, thus, a diffraction analysis of individual nanograins. A recently developed method based on NBD allows determining crystallographic orientation relationships and analyzing the phases of individual nanograins. This article below sets forth the analytical possibilities of this method by way of a complete evidence of twin and small-angle grain boundaries in nanocrystalline copper and a phase identification of precipitates in an AlMg5Si2 alloy.

B4GALT family mediates the multidrug resistance of human leukemia cells by regulating the hedgehog pathway and the expression of p-glycoprotein and multidrug resistance-associated protein 1

β-1, 4-Galactosyltransferase gene (B4GALT) family consists of seven members, which encode corresponding enzymes known as type II membrane-bound glycoproteins. These enzymes catalyze the biosynthesis of different glycoconjugates and saccharide structures, and have been recognized to be involved in various diseases. In this study, we sought to determine the expressional profiles of B4GALT family in four pairs of parental and chemoresistant human leukemia cell lines and in bone marrow mononuclear cells (BMMC) of leukemia patients with multidrug resistance (MDR). The results revealed that B4GALT1 and B4GALT5 were highly expressed in four MDR cells and patients, altered levels of B4GALT1 and B4GALT5 were responsible for changed drug-resistant phenotype of HL60 and HL60/adriamycin-resistant cells. Further data showed that manipulation of these two gene expression led to increased or decreased activity of hedgehog (Hh) signaling and proportionally mutative expression of p-glycoprotein (P-gp) and MDR-associated protein 1 (MRP1) that are both known to be related to MDR. Thus, we propose that B4GALT1 and B4GALT5, two members of B4GALT gene family, are involved in the development of MDR of human leukemia cells, probably by regulating the activity of Hh signaling and the expression of P-gp and MRP1.

Chimney stents for endovascular repair of juxtarenal aortic aneurysms with unfavourable anatomy

AIM

The aim of this paper was to present our experience with the use of chimney grafts in endovascular aneurysm repair (EVAR) of juxtarenal aortic aneurysms (JAA) with unfavourable anatomy.

METHODS

Between January 2001 and January 2011, 5 patients (4 men and 1 woman; mean age 78 years) with JAAs were treated with chimney grafts in the renal arteries. All the cases were at high risk for open repair and were unsuitable for standard endovascular abdominal aortic aneurysm repair because of short neck length, or large neck angulation. Six chimney stents (5 balloon expandable stents and 1 self-expandable stent) were implanted into the renal arteries.

RESULTS

The technical success was 100%. The final angiography showed excellent results, with good flow into the kidneys and complete exclusion of the aneurysm sac and no type I endoleaks. The average follow-up period was 15.8 months (range, 1-52 months). One patient died two months after surgery because of heart failure. An early small type II endoleak found in one patient resolved within three months without treatment. All chimney grafts were patent at the end of the follow-up period.

CONCLUSION

The chimney graft technique is an expansion of endovascular aortic repair (EVAR), especially suitable for juxtarenal aortic aneurysms in patients with a high surgical risk. The chimney graft technique is feasible, even in the setting of unfavourable aortic anatomy. Long-term results are still unknown.

Hyperthermia enhances mapatumumab-induced apoptotic death through ubiquitin-mediated degradation of cellular FLIP(long) in human colon cancer cells

Colorectal cancer is the third leading cause of cancer-related mortality in the world; the main cause of death of colorectal cancer is hepatic metastases, which can be treated with hyperthermia using isolated hepatic perfusion (IHP). In this study, we report that mild hyperthermia potently reduced cellular FLIP(long), (c-FLIP(L)), a major regulator of the death receptor (DR) pathway of apoptosis, thereby enhancing humanized anti-DR4 antibody mapatumumab (Mapa)-mediated mitochondria-independent apoptosis. We observed that overexpression of c-FLIP(L) in CX-1 cells abrogated the synergistic effect of Mapa and hyperthermia, whereas silencing of c-FLIP in CX-1 cells enhanced Mapa-induced apoptosis. Hyperthermia altered c-FLIP(L) protein stability without concomitant reductions in FLIP mRNA. Ubiquitination of c-FLIP(L) was increased by hyperthermia, and proteasome inhibitor MG132 prevented heat-induced downregulation of c-FLIP(L). These results suggest the involvement of the ubiquitin-proteasome system in this process. We also found lysine residue 195 (K195) to be essential for c-FLIP(L) ubiquitination and proteolysis, as mutant c-FLIP(L) lysine 195 arginine (arginine replacing lysine) was left virtually un-ubiquitinated and was refractory to hyperthermia-triggered degradation, and thus partially blocked the synergistic effect of Mapa and hyperthermia. Our observations reveal that hyperthermia transiently reduced c-FLIP(L) by proteolysis linked to K195 ubiquitination, which contributed to the synergistic effect between Mapa and hyperthermia. This study supports the application of hyperthermia combined with other regimens to treat colorectal hepatic metastases.

Aldo-keto reductase 1C3 may be a new radioresistance marker in non-small-cell lung cancer

Human aldo-keto reductase 1C3, type 2 3α-hydroxysteroid dehydrogenase (HSD)/type 5 17β-HSD (AKR1C3) is known to be involved in steroid, prostaglandin and lipid aldehyde metabolism. The role of AKR1C3 in the radiosensitivity to X-rays of human non-small-cell lung cancer (NSCLC) cells was explored. In this study, a specific small interfering RNA (siRNA) to target the AKR1C3 gene was used. A suite of readouts including cell survival were determined using a colony formation assay; apoptosis evaluated by Annexin V expression levels, irradiation-induced cytotoxicity established using a MTT cell viability assay and cell cycle distribution measured by flow cytometry were used in characterizing the role of the AKR1C3 gene. Although AKR1C3 was significantly overexpressed in both our radioresistant subclone cells and NSCLC tissues, a specific AKR1C3 siRNA significantly enhanced cell radiosensitivity and was concomitant with decreased expression of this gene. Furthermore, reduced interleukin-6 (IL-6)-mediated radioresistance was observed when siRNA was used to knock down AKR1C3 activity. This AKR1C3-mediated radioresistance was correlated with an arrest in the G2/M cell cycle and a decreased induction of apoptosis. AKR1C3 may present a potential therapeutic target in addressing radioresistance of NSCLC, and in particular in IL-6-mediated radioresistance.

Administration of PLGA nanoparticles carrying shRNA against focal adhesion kinase and CD44 results in enhanced antitumor effects against ovarian cancer

The two membrane-bound proteins, focal adhesion kinase (FAK) and CD44, are involved in processes critical to cancer progression. FAK has an active role in angiogenesis, cell proliferation and cell apoptosis, whereas the heavily glycosylated CD44 has been implicated in cancer metastasis. Here, using short hairpin RNA (shRNA) against FAK and CD44, we demonstrate that simultaneous knockdown of both these genes inhibits cancer growth more efficiently than knockdown of either gene individually. Plasmids targeting these genes or non-relative control sequences were constructed and delivered to ovarian cancer targets by biodegradable poly D,L-lactide-co-glycolide acid nanoparticles (PLGANPs). Nude mice were utilized in an intraperitoneal model of ovarian carcinomatosis to assess antitumor efficacy in vivo. Single gene knockdown resulted in significantly smaller tumors than those observed in the empty-vector control (P's<0.001). More importantly, knockdown of both genes resulted in tumors smaller than both the empty-vector group (P<0.0001) and the single gene knockdown groups (P's<0.001). Knockdown of both FAK and CD44 resulted in tumors with inhibited angiogenesis, reduced proliferation and increased apoptosis as compared with controls (P's<0.001) and single knockdown groups (P's<0.05). These results indicate that dual knockdown of FAK and CD44 in the tumors of patients with ovarian cancer may have an enhanced therapeutic effect, and point toward a mechanism involving the inhibition of angiogenesis, cellular proliferation and the induction of apoptosis.

ANXA2 remodels the microstructures of caco2 cells

ANXA2 was reported as a multiple tumors relevant gene expressed excessively in many tumor tissue types, especially in the cancers from digestion system, and its aberrant expression enhances the malignant properties of cancer cells. We suppose that the microstructure heterogeneity is important to maintain the malignancy of cancer cells, and excessive ANXA2 expression enhance the malignancy by remodeling the microstructures of cancer cells. To validate the proposal, the ANXA2-/-caco2 cell line was generated and the changes of the microstructures in the ANXA2 deleted and wild type caco2 cells were observed under fluorescence microscope, laser scanning confocal microscope and electron microscope. We found that ANXA2 deletion induced the pseudopodia shorted and spared, non-stained areas increased, mitochondria decreased, and the expression and polymerization of F-actin and β-tubulin changed. By the findings above, it is firstly reported in this paper that the ANXA2 excessive expression induces the significant changes of the microstructures in cancer cells. Combining our previous data together, our results indicate that ANXA2 excessive expression enhances the malignancy of cancers partially by remodeling the cell microstructures.

Antiviral activity and mode of action of extracts from neem seed kernel against duck plague virus in vitro1

Four fractions obtained from alcohol extracts of neem (Azadirachta indica) seed kernel by column chromatography were investigated for antivirus activity against the duck plague virus (DPV) in vitro. Duck embryo fibroblasts (DEF) infected with DPV were treated with the neem seed kernel extracts, and the effect of antivirus was judged by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide colorimetric method assay and direct immunofluorescence assay. The mode of action was tested by the plaque reduction assay. The results showed that fractions 1 to 3 were inactive. The median inhibitory concentration (IC(50)) of fraction 4 was 10.9 μg/mL and inhibited the virus protein expression in the direct immunofluorescence assay. In the plaque reduction assay, fraction 4 could significantly reduce the number of plaques compared with the negative control (P < 0.01) in all modes of action. This study indicated that the fourth fraction obtained from neem seed kernel could improve the viability of infected cells, and reduce the cytopathic effects caused by DPV and the amount of the virus protein expressed in virus-infected cells. The antiviral activity works in the whole process of virus infecting the normal cells.

Abstract P2-11-10: Prospective memory impairment in early breast cancer survivors: Finally homing in on the real deficit?

Background There is still much debate about the impact of early breast cancer (EBC) treatment on memory functioning. One limitation of existing studies is that they are based on neuropsychological testing procedures which may not be sensitive enough to detect memory problems as encountered in daily life. In fact, no study has objectively assessed everyday memory performance in EBC. One crucial aspect of using memory in daily activities is to remember to do something at an appropriate time in the future without being asked to do so-defined as “prospective memory” (PM). Despite its importance for daily functioning, little is known about PM in EBC patients. Thus, we investigated whether EBC survivors who were within 1 year of having completed adjuvant chemotherapy have PM impairment in comparison to age-matched healthy controls. In addition, we evaluated the contributions of fatigue and depression to PM functioning.

Methods We undertook a cross sectional quantitative case-control study (n = 80) comparing EBC patients from the Ottawa Hospital Regional Cancer Centre with age and education-matched healthy controls from the community. A standardized test of PM (Memory for Intention Screening Test) was administered to both groups. Impairment was defined as a score that fell 2 standard deviations below the mean performance of the control group. Standardized measures of depression (CESD) and fatigue (Fact-F) were also completed.

Results Age was well balanced between the groups (case and control mean age 54y, p = .84). EBC patients performed more poorly than controls on the PM test (p &lt; .001) and had a significantly higher rate of impairment (23% vs. 5%, McNemar χ2, p &lt;.01, odds ratio=5.5, 95% CI=1.7745 to 17.1473). A series of hierarchical regressions showed that patients PM performance was affected by fatigue (p &lt;.05), but not depression (p = .51).

Conclusions The results demonstrate reduced memory performance in EBC survivors, with a specific impact on PM. Women who complain of ‘chemo fog’ should be evaluated carefully for PM deficits and their concerns should be acknowledged. An important finding from this study is the demonstration that fatigue is associated with memory deficits when memory as used in everyday life is evaluated. This finding which is suggestive of a common mechanism involved in fatigue symptoms and everyday memory disturbances raises the possibility that interventions targeted at improving fatigue may also improve memory functioning and quality of life in EBC survivors. Further longitudinal studies should be conducted to critically evaluate the role of chemotherapy by assessing PM before the initiation of chemotherapy and in EBC patients receiving only adjuvant hormonal therapy.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-11-10.

Abstract P3-04-11: Systemic treatment decision making for patients with stage I and II, hormone receptor positive, her2/neu negative breast cancer

Background: Oncotype DX is a clinically validated risk stratification tool that can predict the risk of recurrence and the benefit of adjuvant chemotherapy in women with hormone receptor positive (HR+), HER2/neu negative early stage breast cancer (EBC). This tool has been available to oncologists in Ontario since April 2010 at significant cost, yet no guidelines exist regarding their use. This retrospective chart review examined the factors that were associated with use of Oncotype DX at a tertiary care cancer centre.

Materials and methods: One hundred patients (pts) diagnosed with HR+, HER2/neu negative EBC (stage I-II), who underwent Oncotype DX testing between April 1, 2010, and June 30, 2011 were included in the study. A second control group of 100 patients with similar disease characteristics but who did not receive Oncotype DX testing were randomly selected. Data collection included demographics, tumor grade and stage, and Adjuvant! Online recurrence risk scores. The distribution of patients in each category was compared using the chi-square test to detect statistically significant differences between distributions.

Results: Median age in the Oncotype DX group was 58 years (r: 26–77) and 63 years (r: 30–81) in the control group. 20 patients in the Oncotype DX group were aged 35–49, 57 patients were aged 50–64, and 23 patients were aged 65 or older, while the control group had 16, 43, and 41 patients, respectively (p = 0.02). The Oncotype DX group had 72 pre- and perimenopausal pts and 28 postmenopausal patients, while the control group had 81 and 19 patients, respectively (p = 0.13). 20, 56, and 24 pts in the Oncotype DX group had grade 1, 2, and 3 histology, respectively, vs. 44, 44, and 12, respectively in the control group (p &lt; 0.01). The Oncotype DX group had 7 patients with tumors between 1–10 mm, 55 between 10.1–20 mm, 34 between 20.1–50 mm, and 4 greater than 50 mm, vs. 29, 42, 23, and 1, respectively in the control group (p &lt; 0.01). When 10-year Adjuvant Online recurrence scores were calculated using tamoxifen, 17, 67, and 16 patients in the Oncotype DX group had risk scores of &lt;15, 15–25, and &gt;25, respectively, vs. 62, 33, and 5 in the control group (p &lt; 0.01). When the scores were calculated using tamoxifen plus an aromatase inhibitor, 49, 42, and 9 patients in the Oncotype DX group, and 75, 24, and 1 patients in the control group fell into these categories, respectively (p &lt; 0.01). Median Oncotype DX recurrence score was 17 (r: 0–70), with 10-year recurrence risk of 11% (r:3–34%).

Conclusions: This single-centre series is aimed at identifying potential clinical and pathological factors which can influence physicians' decision to request Oncotype DX testing for pts with EBC. Physicians were more likely to request Oncotype DX testing for patients that were younger, had larger and higher grade tumors, and higher Adjuvant! Online recurrence risk scores. These results will be used to design a prospective study evaluating these factors and how Oncotype DX testing may influence treatment decision making.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-04-11.

Abstract P5-01-01: Predicting OncoDX Recurrence Scores with Immunohistochemical Markers

Background: Standard immunohistochemistry (IHC) performed for invasive breast carcinoma includes ER, PR and Her2/Neu status, and these markers are used in conjunction with other patient and tumour factors to determine prognosis and guide treatment. Many, but not all, low stage, lymph node (LN) negative, ER positive patients have a good prognosis without chemotherapy. Thus a demand exists for predictive tools to stratify patient risk within this subgroup. It has been reported that, for a subset of ER positive Her2/Neu negative patients, the 21 gene OncotypeDX recurrence score (Onco-RS) adds independent prognostic information to that obtained from these standard IHC markers (1). As several genes analyzed for the Onco-RS relate to ER, PR, HER2/neu and proliferative status, it is reasonable to try to incorporate clinical-pathological variables and these IHC scores into a predictive model. Indeed, recent studies suggest that most of the additional information provided by the OncoDX-RS may be obtained more cost effectively using the Ki-67 IHC based proliferation percentage combined with a semi-quantitative assessment of standard IHC markers including ER and PR and Her2/neu (2). The aim of this study is to assess the ability of a simple combined IHC recurrence score (IHC-RS) to predict Onco-RS. The IHC-RS was derived from a simple semi-quantitative assessment of ER and PR combined with Ki-67 proliferation percentage.

Design: A cohort of 159 women aged 27–78 with ER positive, HER2/neu negative breast cancer completed Oncodx testing between March 2010 and May 2012. This sample reflects the population selected at our institution for Oncotype testing. The variables investigated for inclusion in a model to predict RS score included tumor grade, stage, patient age, Allred ER & PR and Ki-67 percentage.

Results and Discussion: A predictive model was developed to generate a recurrence score (IHC-RS) using stepwise multiple regression incorporating Allred ER score, Allred PR score and Ki-67 percentage. The best subset model (Schwartz BIC) accounted for 60.7% of the Onco-RS variability (adjusted R2 = 60.7, p = 0.05).

In addition, analysis of individual cases where the IHC-RS was not in agreement with the Onco-RS reveals that the Onco-RS, although technically highly reproducible, may suffer from sampling error. The IHC-RS is more robust with respect to sampling error, owing to the retention of tumor architecture inherent in IHC. IHC, however, can lack the technical reproducibility and transportability inherent in the Onco-RS methodology. There are clearly advantages to an ICH derived multi-score such as IHC-4 (3) or the simpler IHC-RS proposed in this study. Full utility of any IHC-based recurrence score will require standardization of testing and scoring both within and across different testing laboratories. In addition, full utility of any IHC based model will require direct correlation to patient outcome, rather than to a surrogate marker such as the Onco-RS used in this study.

1. M Dowsett et al. J Clin Oncol. 2010 Apr 10; 1829–1834 2. Cuzick J et al. J Clin Oncol. 2011 Nov 10;4273-8. 3. S Barton et al. British Journal of Cancer (2012) 106, 1760–1765.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-01-01.

Abstract P3-13-05: Evaluating efficacy of de-escalated bisphosphonate therapy in metastatic breast cancer patients at low-risk of skeletal related events. TRIUMPH: A pragmatic multicentre trial

Background: Optimal bisphosphonate (BP) dosing intervals for breast cancer patients (pts) with bone metastases (BM) remain unknown. BP are usually prescribed q3-4 wk regardless of individual pt risk for skeletal related events (SREs). Recent evidence (Amadori J Clin Oncol, 2012 suppl; abstr 9005) shows that q12 wk BP is as effective as q4 wk in pts previously treated with &gt;9 cycles of q4 wk therapy. Hence, further evaluation of modified BP dosing strategies is warranted. The objective of the current study was to show in women with biochemically defined low-risk bone disease that IV BP use every q12 wk for 1 year is sufficient to maintain stability of the bone turnover [measured by serum c-telopeptide (CTx) or bone specific alkaline phosphatase (BSAP)].

Methods: Eligible pts with BM, who had received &gt;3 months of q3-4 wk IV BP and no systemic treatment change within 4 wks of study entry were enrolled. Low risk was defined as serum CTx &lt;600 ng/L. Biochemical failure was defined as CTx levels &gt;600 ng/L at baseline, weeks 6, 12, 24, 36 or 48. Evaluation of palliative benefit of 12-wk IV BP therapy was measured by SREs, analgesic use, and self-reported pain (BPI and FACT-BP).

Results: Between Oct. 2010-Sept. 2011, 85 pts consented to screening, with 13 found ineligible. In the 71 accrued pts baseline characteristics were: mean age 60 (SD 13), median time from breast cancer diagnosis to development of bone metastases 4 months (IQR 82), median duration of prior BP therapy 14 months (IQR 19), and mean number of SREs/yr prior to entering study 0.35 (SD 0.76). Baseline median CTx was 120 ng/L (IQR 240) and BSAP 9.2 IU/L (IQR 3). To date: 26/71 pts (36%) remain on study. Reasons for coming off study include; study completion (18), elevation of CTx &gt;600ng/L (10), or on study SRE (3). An elevation of CTx between baseline and wk 6 was significantly associated with coming off study early (p = 0.008). For pts who had had an SRE before study entry the odds ratios for coming off study early due to an on study SRE or elevated CTx was 1.005 (CI 1.002–1.009; p = 0.007) and for coming off early for an SRE was 0.0245 (CI 0.061–0.094; p = 0.046) respectively. Of the 8/13 pts who were ineligible due to baseline CTx &gt;600ng/L, 6 had an SRE within 1 year of screening.

Conclusion: De-escalating BP therapy to 12 weekly in low risk pts has advantages for both the pt and the health care system. Individual risk of SREs is highly variable, however baseline serum CTx levels &lt;600 ng/L is associated with a low risk of subsequent SREs. While larger trials are required to assess whether increasing CTx with de-escalated therapy will lead to higher rates of SREs or not (Coleman et al. J Clin Oncol 2012 suppl; abstr 511). However, the results of this study and Amadori et al. would suggest that de-escalated BP treatment will likely become a new standard of care after a limited period of q 4wk treatment.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-13-05.

Mitochondrial bioenergetic deficits in the hippocampi of rats with chronic ischemia-induced vascular dementia

Vascular dementia (VD), defined as a loss of memory and cognitive function resulting from vascular lesions in the brain, is the second-most-common cause of dementia in the elderly, after Alzheimer's disease. In recent years, research has focused on the pathogenesis of VD, and mitochondrial bioenergetic deficits have been suggested to contribute to VD onset. To further investigate the role of mitochondria in VD, we used a rat model of VD, which involved permanent bilateral occlusion of the common carotid arteries (with a 1-week interval between artery occlusion to avoid an abrupt reduction in cerebral blood flow) leading to chronic cerebral hypoperfusion. Prior to occlusion, male Wistar rats underwent 7 days of Morris water maze training. Only animals that could swim and passed the Morris water maze test were chosen for the study. After 5 days of Morris water maze training, mitochondria from the hippocampi of rats, which were randomly selected from animals that could complete the Morris water maze test, were isolated for functional assessment. Mitochondria isolated from the hippocampi of rats from the ischemia group had decreased pyruvate dehydrogenase protein levels, and increased oxidative stress, as manifested by increased hydrogen peroxide production. The ischemia group mitochondria also exhibited decreased respiration coupled to decreased expression and activity of the electron transport chain complex IV (cytochrome c oxidase). These results indicate that the mitochondrial oxidative metabolism is inhibited in the hippocampi of rats following chronic ischemia-induced VD. As the mitochondrial oxidative metabolism deficits, namely mitochondrial bioenergetic deficits directly affect the functions of neurons, it may contribute to VD onset.