A therapeutic antibody targeting annexin-A1 inhibits cancer cell growth in vitro and in vivo

In this study we conducted the first investigation to assess the efficacy of a novel therapeutic antibody developed to target annexin-A1 (ANXA1). ANXA1 is an immunomodulatory protein which has been shown to be overexpressed in, and promote the development and progression of, several cancer types. In particular, high ANXA1 expression levels correlate with poorer overall survival in pancreatic and triple-negative breast cancers, two cancers with considerable unmet clinical need. MDX-124 is a humanised IgG1 monoclonal antibody which specifically binds to ANXA1 disrupting its interaction with formyl peptide receptors 1 and 2 (FPR1/2). Here we show that MDX-124 significantly reduced proliferation (p < 0.013) in a dose-dependent manner across a panel of human cancer cell lines expressing ANXA1. The anti-proliferative effect of MDX-124 is instigated by arresting cell cycle progression with cancer cells accumulating in the G1 phase of the cell cycle. Furthermore, MDX-124 significantly inhibited tumour growth in both the 4T1-luc triple-negative breast and Pan02 pancreatic cancer syngeneic mouse models (p < 0.0001). These findings suggest ANXA1-targeted therapy is a viable and innovative approach to treat tumours which overexpress ANXA1.

Abstract 5294: MDX-124, a novel annexin-A1 antibody, induces significant anti-cancer activity in multiple preclinical models

Annexin-A1 (ANXA1) is secreted from both cancer and immune cells in response to several physiological stimuli and modulates cellular functions through interactions with formyl peptide receptors (FPR1/2). Overexpression of ANXA1 has been observed in multiple cancers, including triple-negative breast (TNBC), colorectal, lung, pancreatic, gastric and prostate, and correlates with poor prognosis and decreased overall survival. ANXA1 has also been shown to promote cancer cell proliferation, angiogenesis, migration and drug resistance, and to modulate the tumor microenvironment. MDX-124 is a novel humanized antibody targeting ANXA1. Previously we presented data demonstrating its significant anti-proliferative activity. Here we provide further data on the mechanism of action of MDX-124, notably its impact on tumor growth, cell cycle arrest and migration in several preclinical cancer models. Incubation of pancreatic (BxPC-3), lung (A549) and TNBC (MDA-MB-231) cancer cell lines with MDX-124 for 24 h decreased the proportion of cells in S-phase by up to 18.3% with a concomitant increase in G1 phase of up to 33.5% versus untreated cells. This effect occurred in a dose-dependent manner and is consistent with an MDX-124 mediated increase in cell cycle arrest. After 72 h incubation with MDX-124, the migratory ability of gastric (AGS), prostate (PC-3), TNBC (MDA-MB-231), lung (A549), pancreatic (MIA PaCa-2) and colorectal (LoVo) cancer cells was significantly reduced in a dose-dependent manner when compared to untreated controls. Proteomic analysis following incubation of MDX-124 with a panel of cancer cell lines for 72 h demonstrated substantial alterations in the level of expression and phosphorylation of multiple key oncogenic proteins. In the MycCaP-Bo syngeneic model of bone metastatic prostate cancer, mice treated with the murine analog of MDX-124 (10 mg/kg, BIW) had a 52% reduction in mean tumor growth after 14 days compared to isotype control treated mice. In conclusion, our data indicate that targeting ANXA1 with MDX-124 inhibits key tumorigenic processes in several clinically challenging cancer indications. MDX-124 therefore provides an innovative approach to cancer therapy. Medannex initiated a First-In-Human study in Q4 2021 to evaluate MDX-124 in solid malignancies known to overexpress ANXA1.

Citation Format: Fiona C. Dempsey, Hussein Al-Ali, Scott J. Crichton, Charlene Fabian, Chris Pepper, Bin-Zhi Qian, Xue-Feng Li, Christopher N. Parris. MDX-124, a novel annexin-A1 antibody, induces significant anti-cancer activity in multiple preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5294.

Genome-wide screening identifies Polycomb repressive complex 1.3 as an essential regulator of human naïve pluripotent cell reprogramming

Uncovering the mechanisms that establish naïve pluripotency in humans is crucial for the future applications of pluripotent stem cells including the production of human blastoids. However, the regulatory pathways that control the establishment of naïve pluripotency by reprogramming are largely unknown. Here, we use genome-wide screening to identify essential regulators as well as major impediments of human primed to naïve pluripotent stem cell reprogramming. We discover that factors essential for cell state change do not typically undergo changes at the level of gene expression but rather are repurposed with new functions. Mechanistically, we establish that the variant Polycomb complex PRC1.3 and PRDM14 jointly repress developmental and gene regulatory factors to ensure naïve cell reprogramming. In addition, small-molecule inhibitors of reprogramming impediments improve naïve cell reprogramming beyond current methods. Collectively, this work defines the principles controlling the establishment of human naïve pluripotency and also provides new insights into mechanisms that destabilize and reconfigure cell identity during cell state transitions.

Abstract P5-08-06: MDX-124, a novel annexin-A1 antibody, shows anti-tumor efficacy in several preclinical models of triple-negative breast cancer

Triple-negative breast cancer (TNBC) accounts for 10-15% of all breast cancer cases and is a particularly aggressive form of the disease, with poorer prognosis compared to other breast cancer subtypes. Advances in TNBC treatment have been made with the introduction of checkpoint inhibitors, PARP inhibitors and antibody drug conjugates. However, these therapies still have several limitations including low patient response rates, treatment resistance or relapse, and considerable side effects. Therefore, a significant unmet clinical need remains to develop novel targeted agents to treat TNBC. Annexin-A1 (ANXA1) is a phospholipid binding protein secreted in response to several physiological stimuli where it activates formyl peptide receptors (FPR1/2) triggering multiple oncogenic cell signaling pathways. Overexpression of ANXA1 by TNBC cells has been shown to influence several cancer-related processes including cell growth, cell cycle progression, angiogenesis, migration and invasion. In addition, ANXA1 has been shown to have immunomodulatory effects on T-cells, macrophages and dendritic cells. High ANXA1 expression in TNBC patients correlates with both poor overall survival and progression-free survival, indicating ANXA1 is a therapeutic target in TNBC. MDX-124 is a novel humanized antibody targeting ANXA1, and we have previously demonstrated its significant anti-proliferative activity. Here we present additional data showing the efficacy of MDX-124 in preclinical models of TNBC. Methods: The impact of MDX-124 on cell cycle progression was evaluated by measuring changes in DNA content using flow cytometry and analyzed with FlowJo™ software.The modulation of key oncogenic cell signalling pathways by MDX-124 was assessed using human phospho-kinase and XL Oncology Proteome Profiler™ antibody arrays. The effect of MDX-124 in combination therapy with chemotherapy was studied in-vitro using MTT cell proliferation assays, whilst synergy with anti-PD-1 therapy was evaluated using the EMT6 syngeneic mouse model of TNBC. Results: MDX-124 treatment dramatically decreased the proportion of HCC1806 TNBC cells in S-phase by 29.1% with a concomitant increase in G1 of 33.5% versus untreated cells. This occurred in a dose-dependent manner and is consistent with an MDX-124 mediated increase in cell cycle arrest.Treatment of HCC1806 TNBC cells with MDX-124 altered the expression of key oncogenic proteins and the phosphorylation of several kinases that regulate cell signaling pathways involved in proliferation, survival and migration. Notably, MDX-124 substantially reduced ERK and AKT phosphorylation by 84% and 72% respectively versus untreated control cells. In the HCC1806 TNBC cell line, proliferation was significantly reduced after 72 h treatment with MDX-124 and chemotherapy versus control.In the EMT6 syngeneic mouse model of TNBC, the murine analogue of MDX-124 (MDX-001) potentiated mean tumor growth inhibition of single agent anti-PD-1 treatment by 15%. Additionally, 30% of treated mice showed tumor regression in the MDX-001 combination therapy group versus 10% in the single agent anti-PD-1 group. This suggest that anti-ANXA1 antibody therapy acts synergistically with anti-PD-1 immunotherapy.Conclusion: MDX-124 binds to secreted and extracellular ANXA1 disrupting interactions with FPR1/2. This results in altered expression levels of several key cancer-related proteins preventing the activation of oncogenic signaling pathways that promote cancer progression. MDX-124 has demonstrated anti-cancer activity in several TNBC cell line and mouse models, as both a single agent and in combination with other drugs, including anti-PD-1 immunotherapy. Medannex plan to initiate a First-In-Human study in Q4 2021 to evaluate MDX-124 in solid malignancies, including TNBC.

Citation Format: Fiona C Dempsey, Hussein Al-Ali, Scott J Crichton, Charlene Fabian, Chris Pepper, Christopher N Parris. MDX-124, a novel annexin-A1 antibody, shows anti-tumor efficacy in several preclinical models of triple-negative breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-08-06.

Efficacy of MDX-124, a novel anti-annexin-A1 antibody, in preclinical models of pancreatic cancer

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Background: Pancreatic cancer is a highly fatal disease with poor survival and response to both chemotherapy and immunotherapy. Novel approaches to treat this disease are urgently required. Annexin-A1 (ANXA1) is secreted in response to several physiological stimuli where it activates formyl peptide receptors (FPR1/2) triggering multiple oncogenic processes. High ANXA1 expression in pancreatic cancer patients is associated with poor overall survival, and influences cancer progression, drug sensitivity, migration and invasion. MDX-124 is a novel humanized antibody targeting ANXA1 and we have previously presented data demonstrating its significant antiproliferative activity. Here we present further data showing the efficacy of MDX-124 in several preclinical models of pancreatic cancer. Methods: In-vitro models utilized MIA PaCa-2, PANC-1 or BxPC-3 human pancreatic cancer cell lines. Cell cycle progression was evaluated by measuring changes in DNA content via flow cytometry. Pancreatic cancer cell viability following incubation with MDX-124 (0-10 µM) and 5FU (IC50) was assessed via MTT assay. A transwell migration assay was used to evaluate the effect of MDX-124 (0-50 µM) on pancreatic cancer cell migration. In-vivo efficacy was evaluated using an orthotopic mouse model of metastatic pancreatic cancer (FC1242luc/zsGreen; KPC-derived cell line) with bioluminescent imaging used to quantify the incidence and burden of lung metastases. Results: When compared to untreated MIA PaCa-2 pancreatic cancer cells, MDX-124 treatment decreased the proportion of cells in S-phase by 29% and G2 phase by 9.1%, with a concomitant increase in G1 of 38.1%. This occurred in a dose-dependent manner and is consistent with an MDX-124 mediated increase in cell cycle arrest. MDX-124 significantly reduced the viability of MIA PaCa-2 and PANC-1 cell lines versus an IgG control in a dose-dependent manner. Additionally in these two cell lines, combination of MDX-124 with 5FU (IC50) had a significant synergistic impact reducing cancer cell viability by 99.8% and 91.2% respectively. Furthermore, MDX-124 significantly reduced the migratory ability of MIA PaCa-2 and BxPC-3 pancreatic cancer cells. In the orthotopic model of metastatic pancreatic cancer, the murine analog of MDX-124 (MDX-001), markedly reduced both the incidence and size of lung metastases. Conclusions: MDX-124 demonstrated significant anti-tumor efficacy in several preclinical models of pancreatic cancer as a single agent, with increased potency observed when used in combination with 5FU. Medannex will initiate a First-In-Human study in Q4 2021 to evaluate MDX-124 in solid malignancies, including pancreatic cancer.

Intact predictive motor sequence learning in autism spectrum disorder

Atypical motor learning has been suggested to underpin the development of motoric challenges (e.g., handwriting difficulties) in autism. Bayesian accounts of autistic cognition propose a mechanistic explanation for differences in the learning process in autism. Specifically, that autistic individuals overweight incoming, at the expense of prior, information and are thus less likely to (a) build stable expectations of upcoming events and (b) react to statistically surprising events. Although Bayesian accounts have been suggested to explain differences in learning across a range of domains, to date, such accounts have not been extended to motor learning. 28 autistic and 35 non-autistic controls (IQ > 70) completed a computerised task in which they learned sequences of actions. On occasional "surprising" trials, an expected action had to be replaced with an unexpected action. Sequence learning was indexed as the reaction time difference between blocks which featured a predictable sequence and those that did not. Surprise-related slowing was indexed as the reaction time difference between surprising and unsurprising trials. No differences in sequence-learning or surprise-related slowing were observed between the groups. Bayesian statistics provided anecdotal to moderate evidence to support the conclusion that sequence learning and surprise-related slowing were comparable between the two groups. We conclude that individuals with autism do not show atypicalities in response to surprising events in the context of motor sequence-learning. These data demand careful consideration of the way in which Bayesian accounts of autism can (and cannot) be extended to the domain of motor learning.

Cell-Surface Proteomics Identifies Differences in Signaling and Adhesion Protein Expression between Naive and Primed Human Pluripotent Stem Cells

Naive and primed human pluripotent stem cells (hPSC) provide valuable models to study cellular and molecular developmental processes. The lack of detailed information about cell-surface protein expression in these two pluripotent cell types prevents an understanding of how the cells communicate and interact with their microenvironments. Here, we used plasma membrane profiling to directly measure cell-surface protein expression in naive and primed hPSC. This unbiased approach quantified over 1,700 plasma membrane proteins, including those involved in cell adhesion, signaling, and cell interactions. Notably, multiple cytokine receptors upstream of JAK-STAT signaling were more abundant in naive hPSC. In addition, functional experiments showed that FOLR1 and SUSD2 proteins are highly expressed at the cell surface in naive hPSC but are not required to establish human naive pluripotency. This study provides a comprehensive stem cell proteomic resource that uncovers differences in signaling pathway activity and has identified new markers to define human pluripotent states.

Abstract PD8-08: Development of humanized immune DCIS models using patient peripheral blood derived hematopoietic stem cells (CD34+)

Background:

Ductal carcinoma in situ (DCIS) is the most common form of non-invasive breast cancer. To accurately study the natural progression of DCIS lesions in mice, we devised the mouse-intraductal (MIND) animal model, which involves intraductal injection of human DCIS epithelial cells into the mammary ducts of immunocompromised mice. To improve the translational application of the MIND model, we aimed to mimic the natural microenvironment of human DCIS with patient-derived immune cells and assess the role of engrafted immune cells on human DCIS progression. In order to achieve successful engraftment of the entire immune system in mice, we utilized MISTRG mice. These mice were developed by Rongvaux et al., on an immunodeficient (Rag2-/-IL2rγ-/-) background. The genes encoding human M-CSF (M), human IL-3 (I), SIRP1α (S), human thrombopoietin (TPO)(TR), and GM-CSF (G) were knocked into their respective mouse loci. As such, MISTRG mice are highly permissive for human hematopoiesis, supporting the development and function of lymphocytes, monocytes, and natural killer (NK) cells. In contrast, previous studies have used the humanized CD34+ NOD-SCID IL2rγ-/- mice (CD34+NSG), which are unable to support myeloid cell differentiation due to lack of expression of human-specific cytokines. Moreover, prior xenograft studies in the CD34+NSG mice have not used immune cells derived from the same patient as the tumor.

Results:

Human CD34+ cells derived from patients' peripheral blood were expanded ex vivo ˜100-fold using a novel formulation of culture medium. Transplantation of ex vivo expanded CD34+ cells via tail vein injection of MISTRG mice resulted in the successful engraftment of human immune cells as early as 4 weeks following injection. Successful engraftment was confirmed by flow cytometry using human specific antibodies that recognize human leukocytes (anti-CD45), T cells (anti-CD3), B cells (anti-CD20), and myeloid cells (anti-CD33) in spleen, bone marrow, and peripheral blood of MISTRG mice. Once engraftment was confirmed, DCIS epithelial cells from the same DCIS patients or DCIS cell lines were injected intraductally. Recruitment of patient-derived immune cells to the DCIS lesions was confirmed by immunofluorescence using human-specific antibodies that recognize neutrophils (anti-myeloperoxidase), macrophages (anti-CD68), M2-polarized macrophages (anti-c-MAF), natural killer cells (anti-CD56), dendritic cells (anti-CD21), T cells (anti-CD3) and B cells (anti-CD20).

Conclusion:

This model represents the first to enable the study of mechanisms of DCIS progression in a manner that fully represents the heterogeneity of human disease, including the influence of the patients' own immune cells on DCIS progression.

Citation Format: Behbod F, Harper H, Hansford H, Limback D, Hong Y, Elsarraj H, Ricci LR, Fan F, Tawfik O, May L, Cusick T, Inciardi M, Redick M, Gatewood J, Winblad O, Fields TA, Fabian C, Godwin AK, Fields PE, Meierotto R, Perry J. Development of humanized immune DCIS models using patient peripheral blood derived hematopoietic stem cells (CD34+) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD8-08.

Abstract P4-06-01: Patient derived DCIS mouse-intraductal (MIND) models recapitulate the full spectrum of human patient pathology and histologic features including progression to invasion in a subset of cases

Introduction: The 20-year breast cancer mortality rate following a DCIS diagnosis is ∼3%. Radiation and anti-hormonal therapy of DCIS has not resulted in improved overall survival, which argues against the non-selective use of such therapies in DCIS management. However, some DCIS cases do progress to invasive cancer, and these patients may benefit from treatment. A study of 80 DCIS patients followed for up to 30 years reported a 43% progression rate. Notably, progression was not predicted by grade, as 39% of even low-grade DCIS ultimately progressed to invasive cancer. Clearly, there is a need to identify which DCIS lesions are likely to progress. We have developed a novel mouse xenograft model (mouse-intraductal; MIND) to study the molecular basis of DCIS progression and enable identification of suitable biomarkers that predict invasive progression.

Methods: MIND involves injection of epithelial cells derived from patient breast lesions into the mammary ducts of immunocompromised mice. Serial sections of mouse mammary glands containing DCIS xenograft lesions were examined at time intervals of 3-14 months post-engraftment by histology using hematoxylin and eosin (H&E) and immunohistochemistry using anti-human cytokeratin 5/19, smooth muscle actin, ER, PR, p53, Ki67 and HER-2.

Results: Intraductal injection of cells derived from breast lesions of 28 patients into 133 mice resulted in a successful engraftment rate of 60%. Among these, 12 pure DCIS samples were injected into 35 different mice to create MIND xenografts. As early as three months post-engraftment, the DCIS xenograft cells showed multilayered in situ growth consisting of atypical neoplastic cells with prominent and vesicular nuclei. DCIS MIND xenografts exhibited the full spectrum of human DCIS histologic features, including similar biomarker expression (ER, PR, Ki67, HER-2 and p53) at long-term follow-up after engraftment (up to 12 months). Most remarkably, a subset of xenografts representing 5 patients (5/12; 42%) showed progression to invasion 6-12 months post-engraftment in the absence of any external genetic manipulations. This rate is very similar to that reported for human DCIS progression in untreated patients. MIND DCIS xenograft lesions that progressed showed disruption of basement membrane and myoepithelial layer by the invasive cells, retraction of basement membrane, and micro-invasion. MIND DCIS lesions were enriched in small capillaries, and in some cases clusters of invasive cells appeared inside nearby blood vessels.

Conclusion: The MIND xenograft is a viable model for human DCIS progression that recapitulates histologic features of human DCIS, as well as reported rates of progression to invasion. The availability of this innovative model provides a valuable tool for the discovery of new biomarkers to identify DCIS with invasive potential. The identification of high risk DCIS will ultimately help patients and clinicians choose the best course of therapy and avoid the morbidity and costs associated with unnecessary treatment.

Citation Format: Behbod F, Limback D, Hong Y, Elsarraj H, Berger J, Heddens E, Valdez K, Smith WP, Inciardi M, Reddick M, Gatewood J, Darrah J, Winblad O, Meierotto R, Ricci L, Wagner J, Amin A, May L, Cusick T, Mammen J, Fields T, Godwin AK, Fabian C, Kaufman C, Tawfik O, Fan F. Patient derived DCIS mouse-intraductal (MIND) models recapitulate the full spectrum of human patient pathology and histologic features including progression to invasion in a subset of cases [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-06-01.

Effect of systemic transplantation of bone marrow-derived mesenchymal stem cells on neuropathology markers in APP/PS1 Alzheimer mice

AIMS

Mesenchymal stem cells (MSC) have recently attracted interest as a potential basis for a cell-based therapy of AD. We investigated the putative immune-modulatory effects in neuroinflammation of systemic transplantation of MSC into APP/PS1 transgenic mice.

METHODS

10⁶ MSC were injected into APP/PS1 mice via the tail vein and histological analysis was performed for microglia and amyloid (pE3-Aβ) plaque numbers, glial distribution and pE3-Aβ plaque size. In addition, a biochemical analysis by qPCR for pro-inflammatory, chemoattractant and neurotrophic factors was performed.

RESULTS

MSC are associated with pE3-Aβ plaques. The effects of transplantation on microglia-associated pathology could be observed after 28 days. Animals showed a reduction in microglial numbers in the cortex and in microglia size. Gene expression was reduced for TNF-α, IL-6, MCP-1, and for NGF, in MSC recipients. Also, we investigated for the first time and found no changes in expression of IL-10, CCR5, BDNF, VEGF and IFNγ. PTGER2 expression levels were increased in the hippocampus but were reduced in the cortex of MSC recipients. While there were no transplant-related changes in pE3-Aβ plaque numbers, a reduction in the size of pE3-Aβ plaques was observed in the hippocampus of transplant recipients.

CONCLUSION

This is the first study to show reduction in pE3-Aβ plaque size. pE3-Aβ plaques have gained attention as potential key participants in AD due to their increased aggregation propensity, the possibility for the initial seeding event, resistance against degradation and neurotoxicity. These findings support the hypothesis that MSC-transplants may affect AD pathology via an immune-modulatory function that includes an effect on microglial cells.

Abstract P4-09-02: Omega-3 ethyl esters suppress breast cancer growth by modulating inflammatory signaling

Introduction: Inflammation has been identified as a key contributor to breast cancer development. Both clinical and preclinical studies confirm a role for inflammatory mediators such as cytokines, interleukins, embedded immune cells and prostaglandins in promoting development of breast cancer. Elevated levels/activity of cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) are correlated with a more aggressive disease. Omega-3 fatty acid (n-3) intake is correlated with an inverse risk for breast cancer development and improvement in prognostic markers. One key target of omega-3 fatty acids is the COX-2 enzyme. We hypothesize that one mechanism by which omega-3 fatty acids suppress breast cancer progression is through inhibition of inflammatory signaling.

Methods: The impact of omega-3 ethyl esters (n-3 EE), a component of some omega-3 supplements, on the viability of MCF-7 breast cancer cells grown in a pro-inflammatory environment was assessed by MTT analysis and on proliferation by cell counting. Supplementation of the growth media with IL-6 (10ng/mL) was used to simulate a pro-inflammatory environment. Changes in expression levels of key components of inflammatory pathways were assessed by Western blot analyses and quantitative PCR. Prostaglandin E2 (PGE2) levels were measured using ELISA assays.

Results: A significant suppression in IL-6-induced proliferation was observed when cells were exposed to physiological concentrations (20 uM) of n-3 EE for 96 hrs. Molecular analyses suggest that the suppression of the NF-kB/COX-2/PGE2 signaling axis was important for mediating this effect. These results are consistent with other studies using specific COX-2 inhibitors.

Conclusions: With their potent anti-inflammatory activity, n-3 EE may prove useful in reducing malignancy of breast cancer and also slow development of new breast cancers. Importantly, they appear to have none of the toxicities associated with pharmaceutical COX inhibitors (NSAIDs). Future studies are planned to incorporate nutraceutical compounds to standard therapy to improve efficacy and reduce associated side effects.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-09-02.

Effects of three modifiers of glycolysis on ATP, lactate, hypoxia, and growth in human tumor cell lines in vivo

BACKGROUND

High pretreatment tumor lactate content is associated with poor outcome after fractionated irradiation in human squamous cell carcinoma (hSCC) xenografts. Therefore, decreasing lactate content might be a promising approach for increasing tumor radiosensitivity. As the basis for such experiments, the effects of the biochemical inhibitors pyruvate dehydrogenase kinase dichloroacetate (DCA), lactate dehydrogenase oxamate, and monocarboxylic acid transporter-1 α-cyano-4-hydroxycinnamate (CHC) on tumor micromilieu and growth were investigated.

MATERIALS AND METHODS

Oxygen consumption (OCR) and extracellular acidification rates (ECAR) were measured in FaDu and UT-SCC-5 hSCC in response to DCA in vitro. Mice bearing FaDu, UT-SCC-5, and WiDr colorectal adenocarcinoma received either DCA in drinking water or DCA injected twice a day, or CHC injected daily. WiDr was also treated daily with oxamate. FaDu and UT-SCC-5 were either excised 8 days after treatment for histology or tumor growth was monitored. WiDr tumors were excised at 8 mm. Effect of inhibitors on ATP, lactate, hypoxia, and Ki67 labeling index (LI) was evaluated.

RESULTS

DCA increased OCR and decreased ECAR in vitro. None of the treatments with inhibitors significantly changed lactate content, hypoxia levels, and Ki67 LI in the three tumor lines in vivo. ATP concentration significantly decreased after only daily twice injections of DCA in FaDu accompanied by a significant increase in necrotic fraction. Tumor growth was not affected by any of the treatments.

CONCLUSION

Overall, tumor micromilieu and tumor growth could not be changed by glycolysis modifiers in the three tumor cell lines in vivo. Further studies are necessary to explore the impact of metabolic targets on radiation response.

Abstract P1-06-01: Omega-3 Fatty Acids for Chemoprevention: NF-Kb as a Molecular Target in Both Pre and Post Menopausal High-Risk Breast Cancer Models

Genetic heterogeneity of human breast cancer has complicated treatment, prevention and therapeutic regimens in both clinical and personal care settings. With the recent advances in genetic analyses, human breast tumors are now segregated into four principle molecular subtypes: luminal A, luminal B, basal and HER2 overexpressors, each differing in their driver mutations, estrogen receptor status and dependence on specific cell signaling pathways to maintain growth and tumorigenicity. Omega-3 fatty acids have been shown in previous studies to be effective in modulating tumor growth in preclinical models of breast cancer, but epidemiological studies have been less clear regarding their efficacy as chemopreventive agents. Like many targeted therapies, we hypothesize that omega-3 fatty acids will be most effective against specific subtypes of disease, and it will be critical to identify these subtypes if these dietary agents are to be exploited most effectively. In this current study, the genetic diversity of breast cancer was represented by appropriate cell lines of matching molecular backgrounds and each class of breast cancer were subjected to exposures of omega-3 fatty ethyl esters derived from Lovaza®, an anti-hypertriglyceride medication that is currently under clinical evaluation as a chemopreventive for breast cancer. Previous studies have suggested that a target for omega-3 fatty acid modulation is the transcription factor NF-kB, a central key mediator of inflammation and cancer cell survival. Coined the single most important molecular machinery required for cancer initiation and promotion, NF-kB has been identified to play critical roles in all stages of breast cancer development. The omega-3 ethyl esters demonstrated suppression of NF-kB transcriptional activity, nuclear localization and overall function with high efficacy in the cell lines reflective of the luminal A, luminal B and basal subtypes, correlating with inhibition of proliferation and overall survival. Interestingly, among the panel of breast cancer subtypes, the aggressive HER2 overexpressing cell lines were resistant to the inhibitory effects of the omega-3 ethyl esters. One of the proposed mechanisms by which NF-kB is regulated is co-localization with IkB. siRNA knockdown assays suggest IkB involvement in the repression of NF-kB function by the omega-3 ethyl esters in the responding cell lines. Results from an ongoing clinical trial with omega-3 ethyl esters will help confirm if specific subtypes of breast cancers will be more effectively prevented using these agents, and whether NF-kB is the target by which they are mediating their anti-cancer effects. These studies are some of the first to use molecular profiles to identify potential responders and non-responders for dietary intervention and may provide better direction for future clinical studies evaluating the efficacy of diet and lifestyle in the preventive setting.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-06-01.

SABRE-B: an evaluation of paclitaxel and bevacizumab with or without sunitinib as first-line treatment of metastatic breast cancer

BACKGROUND

The vascular endothelial growth factor (VEGF) pathway can be targeted through VEGF neutralization or VEGF receptor (VEGFR) blockade using tyrosine kinase inhibition. Because laboratory models suggest that combining these approaches might be synergistic, we sought to evaluate the feasibility and efficacy of combining sunitinib with paclitaxel + bevacizumab (PB).

METHODS

Patients with human epidermal growth factor receptor 2 (HER2)-negative, metastatic breast cancer receiving first-line chemotherapy were randomized to PB or PB with sunitinib (PBS), with planned escalation of the sunitinib dose.

RESULTS

Forty-six patients were randomized to PB or PBS with sunitinib dosed at 25 mg p.o. daily. Patients receiving PBS encountered substantial toxicity that precluded adequate treatment. The percentage of patients with grade ≥3 adverse events was greater in the PBS arm than the PB arm (83% versus 57%), and sunitinib dosing was modified in 78% of patients, most often due to neutropenia, febrile neutropenia, and fatigue. In addition, 44% of patients had sunitinib dose reduction to 12.5 mg, and 39% required discontinuation. Patients receiving PBS had more bevacizumab treatment interruptions and discontinuations because of toxicity. Median treatment duration was longer in the PB arm compared with the PBS arm (14.1 versus 11.1 weeks), reflecting early treatment discontinuation of PBS. Because of poor tolerability of the addition of sunitinib to PB, the planned sunitinib dose escalation was halted and the study accrual was terminated.

CONCLUSION

Adding sunitinib to standard doses of bevacizumab plus paclitaxel for metastatic breast cancer is not feasible. Different strategies will be required to evaluate whether there is additional clinical benefit to combining VEGF/VEGFR-targeted agents.

Feasibility of a 6-Month Diet, Exercise, and Behavior Modification Intervention for Post-Menopausal Breast Cancer Survivors

Background: Obesity is prevalent in general population and among breast cancer (BrCa) survivors. Weight at diagnosis and weight gain after diagnosis are associated with increased risk of breast cancer recurrence and mortality. Regular exercise similarly reduces the risk of dying from breast cancer. This study was conducted to determine the feasibility of a structured diet/exercise/behavioral intervention program with a goal to achieve a weight loss of 5% or more, and to study the effect of participation in the program on serum biomarkers of breast cancer risk, measures of overall health, strength, and fitness level..Methods: Subjects in this prospective pilot study are female, overweight BrCa survivors with a BMI &gt;25, and who were at least 3 months out of adjuvant chemotherapy. The 6-month combined modality diet/exercise/behavior modification intervention included: 225 minutes per week of cardiovascular exercise in addition to resistance training, a 1200-1500 calorie/day diet including participant purchased pre-packaged meals and low calorie shakes, and a weekly in-person group behavioral meeting. Women were recruited into groups of 10 to15 participants (total n=50), with a planned goal of 4 cohorts, and anticipated complete data collection by December 2009. Participants underwent pre and post intervention assessments including: anthropometric measures, serum biomarkers, fitness test, and questionnaires to assess food frequency, fatigue, and quality of life. Changes over time were assessed using Wilcoxon signed rank test. We present here the data on first 12 women who have completed the 6 month intervention, out of a planned accrual of 50.Results: Since November 2008, 55 women were screened and 38 women agreed to participate in the 6-month intervention (13 in cohort 1; 10 in cohort 2; 15 in cohort 3). Only 1 participant dropped out of cohort 1 due to a non-study related injury. Major reasons for not participating included: already started another weight loss program, timing, and lack of availability for the evening meeting. Mean age of the participants was 50.7 (range 40-57) and mean time from diagnosis to the time of enrollment was 45 months (range 20-132). Eight five percent of the participants received adjuvant or neo-adjuvant chemotherapy and 77% were either currently or had previously taken anti-hormonal therapy.Median weight was 230 lbs (range 165-268) at baseline .and 198 lbs (range 139.6-243.8) at 6 month (median weight loss: 32 lbs or 14%; p=0.00); median BMI was 36.4kg/m2 (range 30.3-45.4) at baseline and 31.54kg/m2 (range 26.4-40.7) at 6-months (p=0.00), median percent body fat by DEXA scan was 50.9 (range 45-58.4) at baseline and 46.3 (range 35.6-55.4) at 6-months (p=0.00). Participants increased their metabolic equivalent task hours per week (MET/HRS) of exercise from 6.6 (range 0-25) at baseline to 20.4 (range11.8-40.5) at 6-months (p=0.01).Conclusion: A 6-month diet/exercise/behavior modification intervention program is feasible and results in a significant decrease in overall weight and percent body fat among overweight breast cancer survivors.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1058.

Shakeup excitation during optical tunnel ionization

Shakeup of a two-electron system is investigated in the strong infrared laser field limit, both theoretically and experimentally. During tunnel ionization the electron shakes up a second electron to an excited bound state. Theoretically, a complete analytical theory of shakeup in intense laser fields is developed. We predict that shakeup produces one excited sigma(u) D(+)(2) state in approximately 10(5) ionization events. Shakeup is measured experimentally by using the molecular clock provided by the internuclear motion. The number of measured events is found to be in excellent agreement with theory.

Influence of sex, estrous cycle and motherhood on dendritic spine density in the rat medial amygdala revealed by the Golgi method

The medial nucleus of the amygdala (MeA), a sexually dimorphic area, contains estrogen and androgen receptors and has an integrative role in behavioral, vegetative and endocrine activities of rats. The density of dendritic spines along the first 40 microm of dendritic length was studied in neurons from the anterodorsal (MeAD), posterodorsal (MePD) and posteroventral (MePV) aspects of the MeA in males, in virgin females during the four phases of the estrous cycle and in multiparous females in diestrus. The single-section Golgi method was employed (N=48 observations per experimental group). In the three MeA subnuclei males showed more dendritic spines than virgin females (P<0.001), with the only exception being the MePD data of females in diestrus (P>0.05). In virgin females, whereas more dendritic spines were found in diestrus, a decline in these values was found during the proestrus, estrus and metaestrus in the MePD and MePV (P<0.05) but not in the MeAD (P>0.05). Compared with virgin females in diestrus, postpartum rats showed more spines in the MeAD (P<0.001) and fewer in the MePD (P<0.001) but no difference was found in the MePV (P>0.05). These data suggest that there are subregion-specific differences in the density of dendritic spines within the MeA and that they appear to be affected by sex, cyclic fluctuations in the levels of ovarian steroids and following pregnancy in rats. These findings may add to the understanding of the MeA neuronal plastic changes that affect the ongoing processing of sensory information and the organization of the neuroendocrine and behavioral basis of reproduction.

Can a controlled-release oral dose form of oxycodone be used as readily as an immediate-release form for the purpose of titrating to stable pain control?

Two separate trials compared controlled-release (CR) oral oxycodone (administered every 12 hours) with immediate-release (IR) oxycodone (4 times a day) to determine whether patients with chronic pain could be titrated to stable pain control as readily with the CR as with the IR formulation. In one study, 48 patients with cancer pain were randomized to open-label titration with either CR or IR oxycodone (maximum dose, 400 mg/day) for a period of up to 21 days. In a study of similar design, 57 patients with low back pain were titrated with either CR or IR oxycodone (maximum dose, 80 mg/day) for a period of up to 10 days. The majority of patients in both studies were converted to oxycodone from other opioid analgesics. Results of both studies showed no difference between CR and IR oxycodone with respect to both the percentage of patients achieving stable pain control, the time to achieve stable pain control, and the degree of pain control achieved. Among cancer patients, 85% achieved stable analgesia, 92% with the CR formulation and 79% with the IR formulation. Among noncancer patients, 91% achieved stable pain control, 87% with the CR formulation and 96% with the IR formulation. The most commonly reported adverse effects in both studies were similar for the two formulations and were those anticipated with opioids: nausea, vomiting, constipation, somnolence, dizziness, and pruritus. Nausea and vomiting were the most frequently cited reasons for treatment discontinuations. These studies suggest that dose titration can be accomplished as readily with oral CR oxycodone as with IR oxycodone in patients with chronic, moderate to severe pain.

[Bone density of spongiosa and cortical bone of the lumbar spine. Relations to sex, age and spinal deformities in a regional collective of the European Study of Vertebral Osteoporosis (EVOS)]

BACKGROUND AND METHOD

In an additional bone density measurement protocol to the European Vertebral Osteoporosis Study (EVOS) separate spongious and cortical density measurements (sQCT) were carried out at the first 3 lumbar vertebrae in 293 volunteers (92 men and 201 women) in 3 Berlin regional centers.

RESULTS

The spongious mineral density decreases from proximal to distal (L1 to L3), the cortical density increases from proximal to distal, mainly in men. Men showed no significant decrease of cortical density and a lower decrease of spongious density with age compared to women. A comparison of bone mineral density with vertebral height indices of McCloskey/Kanis, Eastell/Melton and Felsenberg showed significant differences of spongious density between a group with normal vertebral height and a group with at least one pathologically degraded vertebra. Individuals with osteoporosis according to the WHO-definition showed a higher prevalence of vertebral deformities. No significant loss of cortical density was observed in these people.

The identification of genes with unique and essential functions in the development of the zebrafish, Danio rerio

In a large-scale screen, we isolated mutants displaying a specific visible phenotype in embryos or early larvae of the zebrafish, Danio rerio. Males were mutagenized with ethylnitrosourea (ENU) and F2 families of single pair matings between sibling F1 fish, heterozygous for a mutagenized genome, were raised. Egg lays were obtained from several crosses between F2 siblings, resulting in scoring of 3857 mutagenized genomes. F3 progeny were scored at the second, third and sixth day of development, using a stereomicroscope. In a subsequent screen, fixed embryos were analyzed for correct retinotectal projection. A total of 4264 mutants were identified. Two thirds of the mutants displaying rather general abnormalities were eventually discarded. We kept and characterized 1163 mutants. In complementation crosses performed between mutants with similar phenotypes, 894 mutants have been assigned to 372 genes. The average allele frequency is 2.4. We identified genes involved in early development, notochord, brain, spinal cord, somites, muscles, heart, circulation, blood, skin, fin, eye, otic vesicle, jaw and branchial arches, pigment pattern, pigment formation, gut, liver, motility and touch response. Our collection contains alleles of almost all previously described zebrafish mutants. From the allele frequencies and other considerations we estimate that the 372 genes defined by the mutants probably represent more than half of all genes that could have been discovered using the criteria of our screen. Here we give an overview of the spectrum of mutant phenotypes obtained, and discuss the limits and the potentials of a genetic saturation screen in the zebrafish.

Patterns of recurrence for advanced colon cancer modified by whole abdominal radiation and chemotherapy

Abdominal failure for colonic carcinoma patients following curative resection has been high in patients with advanced disease stage, particularly when increased numbers of lymph nodes are involved. Surgeons desire curative treatment for their patients, but they interpret local and regional lymph node recurrence as a failure of surgical resection. The effect of current adjuvant treatment protocols on modifying patterns of relapse, particularly in the abdomen, has not been well studied and is of interest to surgeons. We analyzed reported patterns of failure of patients with Stage C2 colon cancer from two colon cancer adjuvant treatment studies; 5-FU plus levamisole (SWOG 8591) and 5-FU, whole-abdominal radiation, and tumor boost. The total number of recurrences in SWOG 8591 at all sites was reduced. The percent of lung relapses was reduced from 34 per cent to 20 per cent in the treatment group, but the percentage of local relapse increased from 20 per cent in the observation group to 27 per cent in the 5-FU plus levamisole group. Similarly, the number of first relapses was fewer at a local site in the 5-FU plus levamisole group, but the percent of relapses at the local site was not reduced (18 vs. 22%). Advanced C2 patients who received regional treatment on 5FU and whole-abdominal radiation produced the lowest percent of local relapse (12%), suggesting a benefit for regional treatment. Further study of patterns of relapse after resection and adjuvant treatment in high risk C2 patients may lead to further progress in control of advanced, curative colon carcinoma.

Adjuvant continuous infusion 5-FU, whole-abdominal radiation, and tumor bed boost in high-risk stage III colon carcinoma: a Southwest Oncology Group Pilot study

PURPOSE

Results of a combined modality adjuvant pilot program of low-dose continuous-infusion 5-fluorouracil, whole-abdominal radiation, and tumor bed boost in patients with colon cancer with involved nodes and serosal involvement are presented.

METHODS AND MATERIALS

Forty-one eligible patients with completely resected T3N1-2M0 colon cancer (modified Astler-Coller C2) were treated with 5-fluorouracil (5-FU) at a dose of 200 mg/m2/day by continuous infusion and 30 Gy of concomitant whole-abdominal radiation in 1 Gy fractions. An additional 16 Gy boost to the tumor bed was administered in 1.6 Gy fractions. After completion of combined modality treatment and a 21-day rest period, patients received 4 days of 5-FU at a dose of 1000 mg/m2 by continuous infusion every 28 days for nine cycles.

RESULTS

Five-year disease-free and overall survival estimates were 58 and 67%, respectively, for all T3N1-2 patients. Five-year disease-free and overall survival estimates for the 19 patients with four or fewer nodes were both 61%. Five-year disease-free survival and overall survival estimates for the 20 patients with more than four involved nodes were 55% and 74%, respectively (the exact number of involved nodes were unknown for two patients). Disease-free and overall survival estimates for patients treated with 5-FU and radiation compare favorably to the 5-FU plus levamisole arm of the intergroup adjuvant colon study (Int 0035/SWOG 8591) in patients with more than four positive nodes where the 5-year disease-free and overall survival estimates were 35% and 39%, respectively. Disease-free and overall survival estimates for patients with four or fewer nodes in the 5-FU plus levamisole arm of the intergroup study were 64 and 68%, which is not markedly different from results obtained with radiation and 5-FU in the current study. There were no treatment-related fatalities. Seventeen percent of patients had severe and 7% had life-threatening toxicity of any kind. One patient had an acute partial bowel obstruction and two patients had chronic low grade enteritis.

CONCLUSION

Continuous infusion 5-FU and whole-abdominal radiation with tumor bed boost should be further investigated in a larger trial of T3N1-2 colon cancer.

Prognostic significance of progesterone receptor levels in estrogen receptor-positive patients with metastatic breast cancer treated with tamoxifen: results of a prospective Southwest Oncology Group study

PURPOSE

Southwest Oncology Group (SWOG) protocol 8228 is a prospective trial designed to investigate the prognostic significance of progesterone receptor (PgR) levels in estrogen receptor (ER)-positive breast cancer patients who were treated with tamoxifen. This study was undertaken because the value of PgR measurements in advanced breast cancer had been assessed previously only in studies that were small, retrospective, or included heterogeneously treated patients.

METHODS

Receptor assays were performed only in the laboratories that met strict quality control guidelines. Of the 398 patients entered, 342 patients were eligible and assessable for the study end points of objective clinical response, time to treatment failure, and overall survival.

RESULTS

Multivariate analysis shows that elevated PgR levels significantly and independently correlated with increased probability of response to tamoxifen, longer time to treatment failure, and longer overall survival. Overall response rate (defined as complete response [CR], partial response [PR], or stable disease [SD] for greater than 6 months) in this trial was 54%. Response rates to tamoxifen were 43%, 53%, and 61% in subsets of patients with less than 10, 10 to 99, and more than 100 fmol/mg PgR, respectively. Exploratory subset analysis using PgR and other prognostic variables identified ER-positive patient subsets with response rates to tamoxifen ranging from 24% (premenopausal patients) to 86% (postmenopausal patients with ER greater than 38 and PgR greater than 329 fmol/mg). No groups of ER-positive patients were identified who had such a low response rate as to absolutely preclude considering the use of tamoxifen. Multivariate analysis showed the independent, statistically significant predictors were: for response to tamoxifen, menopausal status, PgR, and ER; for time to treatment failure, menopausal status, disease-free interval (DFI), PgR, and ER; and for overall survival DFI, PgR, ER, site of disease, and history of adjuvant therapy.

CONCLUSION

We conclude that knowledge of PgR levels together with other clinical information can improve the pretreatment assessment of ER-positive breast cancer patients with metastatic disease.

Poland anomaly with a limb body wall disruption defect: case report and review

We describe a female infant with apparent Poland anomaly (PA) and limb body wall defect. Analysis of the defects suggest that a disruption of the lateral embryonic plate mesoderm may have been responsible for the observed lesions. Because of the overlap of this case with PA, we re-examined previous reports of this syndrome. We think that the lesions could be equally well explained as a mesodermal disruption, and point out a previously unrecognised discrepancy between sex and affected side in sporadic PA and inherited PA which supports this view.

Effect of starch malabsorption on fecal bile acids and neutral sterols in humans: possible implications for colonic carcinogenesis

Epidemiological and experimental studies indicate a strong association between an elevated colon cancer risk and increased fecal excretion of secondary bile acids, neutral sterols, and prolonged gastrointestinal transit time. Starch malabsorption, on the other hand, has been reported to be a possible protective factor in colon carcinogenesis. To study the impact of starch malabsorption on these parameters, 12 healthy volunteers consumed a diet rich in starch for two 4-week periods. During a double-blind crossover trial they received the alpha-glucosidase inhibitor acarbose (BAY g 5421) in one of the study periods and placebo in the other. During acarbose treatment stool wet weight increased by 68%, stool dry weight by 57%, and gastrointestinal mean transit time by 30%. Fecal concentrations (mg/g dry weight) of the neutral sterols coprostanol, coprostanone, campesterol, 4-cholesten-3-one, and beta-sitosterol decreased by 36.8, 48.7, 42.1, 34.6, and 39.4%, respectively, under acarbose. Concentrations of the major secondary bile acids, deoxycholic and lithocholic acid, decreased by 59.9 and 52.2%, respectively. In spite of an increased stool weight, also daily excretion (mg/day) of these two bile acids was lower under acarbose (47.9 and 36.6%, respectively) compared to placebo, whereas excretion of the main primary bile acid, cholic acid, rose from 22.58 mg/day to 379.80 mg/day during the acarbose period. The changes in fecal bile acid and neutral sterol excretion found during acarbose treatment may explain a protective effect of starch malabsorption on colon cancer development.

Reversal of multidrug resistance in HL-60 cells by verapamil and liposome-encapsulated doxorubicin

The means of circumventing multidrug resistance was investigated in HL-60 and HL-60R (a drug resistance variant) cell lines. The HL-60R cell line was developed from the parent line by serial exposure to increasing concentrations of doxorubicin over a 4-month period. This drug resistant cell line expressed P-glycoprotein in its cell surface and is 80-fold more resistant than the parent cell line. Multidrug resistance, as evaluated by a cell cytotoxicity assay using doxorubicin, can be overcome by use of verapamil. Multidrug resistance can also be circumvented when doxorubicin is encapsulated in liposomes. The combination of verapamil and doxorubicin-encapsulated liposomes does enhance circumvention of multidrug resistance beyond the effect of each agent alone, implying a synergistic effect. The lipid composition of the liposomes does affect the rate of drug uptake but not the overall cytotoxic effect of doxorubicin. The synergistic reversal of multidrug resistance by doxorubicin-encapsulated liposomes and verapamil suggests a multifactorial basis for drug resistance in this cell line.

Comparison of lymphangiography and computed tomography scanning in evaluating abdominal disease in stages III and IV Hodgkin's disease. A Southwest Oncology Group study

The authors reviewed the records of 139 patients who had laparotomy plus computed tomography (CT) and/or lymphangiograms (LAG) as part of a their staging workup for Hodgkin's disease, in accordance with Southwest Oncology Group (SWOG) protocol 7808. They evaluated the relative ability of CT and LAG to detect disease in the abdomen. Two regions of the abdomen were designated, the upper and the lower, to further examine the capabilities of CT and LAG in the lower abdomen and CT in the upper abdomen. A LAG was more sensitive (P less than 0.05) than CT in detecting positive lower abdominal nodes. In the upper abdomen, CT scan had low sensitivity for detecting positive nodes, liver, or spleen. This study suggests that LAG of the lower abdomen provided more information than CT, and therefore should not be abandoned as a valid method for detecting nodal disease.

A double-blind, controlled trial in primary care patients with generalized anxiety: a comparison between buspirone and oxazepam

Two hundred thirty patients with generalized anxiety and Hamilton Rating Scale for Anxiety (HAM-A) scores greater than or equal to 18 were subdivided at random, according to a double-blind design, into one group treated with 5-10 mg of oral buspirone t.i.d. or one group treated with 10-20 mg of oral oxazepam t.i.d. for 6 weeks. No anxiolytic treatment was allowed 3 months prior to trial entry. Analysis of demographic variables revealed no significant imbalance between the two treatment groups. Twenty patients were excluded from efficacy analysis because of treatment withdrawal before the first efficacy evaluation on Day 7. Another 4 patients were excluded because they were taking concomitant psychotropic medication. The remaining 206 patients displayed a decrease in HAM-A scores (mean +/- SD) from 23.9 +/- 4.1 to 10.6 +/- 7.7 in the buspirone group and from 23.9 +/- 4.2 to 11.5 +/- 8.0 in the oxazepam group. The two treatment groups were also found to be virtually identical in an "intent to treat" analysis of all 230 patients as well as in other ratings (Hamilton Rating Scale for Depression, Raskin Depression Scale, Covi Anxiety Scale, Physicians Questionnaire, global ratings, and Hopkins Symptom Checklist [HSCL]-56). However, oxazepam was never superior to buspirone in any of the efficacy analyses. Of the 230 patients, 127 spontaneously reported adverse events, including drowsiness, dizziness, headache, nausea, and nervousness. Adverse events were relatively similar in the two groups. In conclusion, buspirone and oxazepam appear to be equally effective in the treatment of generalized anxiety encountered by general practitioners. This outcome, in addition to a previously documented absence of any dependency liability, makes buspirone a clinically important anxiolytic drug.

Effect of starch malabsorption on colonic function and metabolism in humans

To study the impact of starch on colonic function and metabolism, 12 healthy volunteers consumed a controlled diet rich in starch for two 4-wk periods. In one of the study periods they received the glucosidase inhibitor acarbose (BAY g 5421) and placebo in the other. Stool wet weight increased by 68%, stool dry weight by 57%, fecal water content by 73%, and the mean transit time by 30% on acarbose. Breath hydrogen was significantly higher on acarbose, indicating stimulated carbohydrate fermentation in the colon. Fecal bacterial mass (+78%), total stool nitrogen (+53%), bacterial nitrogen (+200%), and stool fat (+56%) were higher in the acarbose than in the control period. The stimulation of fermentation in the human large intestine may be important in colonic and possibly other diseases.

The effect of starch malabsorption on fecal short-chain fatty acid excretion in man

To study the impact of starch malabsorption on fecal short-chain fatty acid concentrations, 11 healthy volunteers consumed a controlled diet rich in starch for 2 4-week periods. They received the glucosidase inhibitor acarbose (Bay g 5421) in one of the study periods and placebo in the other. Stool wet weight increased by 68% and stool dry weight by 57% with acarbose. The fecal concentration (mumol/g wet weight) of n-butyrate (+58%) rose significantly when acarbose was added to the diet. The fecal excretion (mmol/day) of total short-chain fatty acids (+95%) and of their constituents acetate (+97%) and n-butyrate (+182%) was significantly higher when starch malabsorption was induced by acarbose.

Use of charcoal hemoperfusion with sequential hemodialysis to reduce serum methotrexate levels in a patient with acute renal insufficiency

Acute renal failure induced by methotrexate can be complicated by prolonged high serum levels of methotrexate, resulting in pancytopenia and severe mucositis. The role of dialysis in these patients has not been well elucidated. Serum methotrexate levels were successfully lowered in a patient with methotrexate-induced acute renal failure by charcoal hemoperfusion and sequential hemodialysis. No rebound in serum methotrexate levels was observed after perfusion, a phenomenon previously reported as limiting the usefulness of this procedure.

Thyroid lymphoma with gastrointestinal involvement: report of three cases

Three elderly females are reported who presented with high-grade lymphoma of the thyroid and subsequently were found to have extensive gastrointestinal (GI) lymphoma that dominated their clinical courses. One of the patients remains free of disease 30+ months after extensive resection of involved bowel and combination chemotherapy. Two died from disseminated lymphoma. Optimal delivery of therapy in both of the latter patients was impeded by massive gastrointestinal hemorrhage. A review of previously reported cases of thyroid lymphoma, plus those described here, suggests a predilection for these tumors to involve the GI tract independent of other organ metastases.

Methyl-glyoxal bis guanyl hydrazone (methyl-GAG, MGBG) in lymphoma and Hodgkin's disease. A Phase II trial of the Southwest Oncology Group

The Southwest Oncology Group has evaluated methyl-GAG on a weekly schedule among patients with lymphoma and Hodgkin's disease. Among 56 fully and partially evaluable patients responses were seen in 3 of 10 patients with Hodgkin's disease and 11 of 46 patients with lymphoma. Toxicity was acceptable. Methyl-GAG has significant antitumor activity among this group of heavily pretreated patients. Additional trials of methyl-GAG in combination with other agents are underway.

Mitoxantrone in advanced breast cancer: a phase II trial of the Southwest Oncology Group

124 patients with metastatic breast cancer were entered into this phase II trial of mitoxantrone (DHAD). Patients were stratified prior to treatment as good or poor risk, and whether they had received previous therapy with an anthracycline derivative. Mitoxantrone was given every 21 days at a starting dose of 12 mg/m2 for good risk patients and 10 mg/m2 for poor risk patients. Among the group who had not received anthracyclines, 12 are fully or partially evaluable for response with five classified as good risk. One complete response, ongoing at 52 weeks was seen in this group. Of the seven poor risk patients, stable disease was seen in two. 103 patients with prior anthracycline exposure are fully or partially evaluable, 31 good risk and 72 poor risk. There were three partial responses in each group. Toxicity was primarily myelosuppression, and was more severe in the poor risk group. Mitoxantrone when used on this schedule has minimal activity among heavily pretreated patients with metastatic breast cancer.

Combination chemotherapy plus BCG in the treatment of disseminated malignant melanoma: a Southwest Oncology Group Study

The Southwest Oncology Group performed a randomized study comparing combination chemotherapy alone versus combination chemotherapy plus BCG versus DTIC plus BCG in the treatment of disseminated malignant melanoma. A 31% response rate was noted with combination chemotherapy alone, a 27% response rate with combination chemotherapy plus BCG, and an 18% response rate with DTIC plus BCG. Survival was not influenced by type of therapy, but the responders had significantly longer survival than the nonresponders. There appeared to be some significant differences in response as related to age wherein those patients between the ages of 30 and 60 years had a higher response rate to combination chemotherapy as compared to DTIC plus BCG. Those patients older than 60 years of age had a higher response rate in the BCG groups. Furthermore, in those patients older than 60 years of age who responded, their duration of response was longer if they received BCG than those who did not receive BCG. It should be emphasized that those differences noted in various age groups could occur by chance alone. These differences should be studied in the future, by appropriate pretreatment stratifications. Patients with higher peripheral lymphocyte counts had significantly better response rates and those patients with higher numbers of positive delayed hypersensitivity skin tests had significantly greater survival. A significant improvement in survival was noted in patients whose PPD converted from negative to positive during therapy.

Comparative binding affinities of tamoxifen, 4-hydroxytamoxifen, and desmethyltamoxifen for estrogen receptors isolated from human breast carcinoma: correlation with blood levels in patients with metastatic breast cancer

The relative ability of the antiestrogen, tamoxifen, and its monohydroxy and desmethyl metabolites to displace tritiated estradiol from estrogen receptors isolated from human breast carcinoma was determined. 4-Hydroxytamoxifen binds to the estrogen receptor with affinity equal to estradiol, and with 25-50 times higher affinity than does tamoxifen. Desmethyltamoxifen binds to the estrogen receptor with less than 1 per cent of the affinity of tamoxifen. Blood level determination of tamoxifen species in breast cancer patients receiving the drug indicated that after 3 weeks of therapy, desmethyltamoxifen levels were 1.2-1.8 times greater than tamoxifen levels and 4-hydroxytamoxifen levels were 2-18 per cent of parent drug concentrations. Thus, because of its high affinity for the estrogen receptor, the 4-hydroxy metabolite may play a significant antiestrogenic role following tamoxifen therapy, despite its low relative abundance. Desmethyltamoxifen, on the other hand, may have only minor importance as an anti-estrogenic agent following tamoxifen treatment, due to its poor affinity for the estrogen receptor coupled with blood levels that are at most 75 per cent greater than tamoxifen levels at steady state.

Clinical pharmacology of tamoxifen in patients with breast cancer: correlation with clinical data

Blood tamoxifen levels were determined for patients with metastatic breast cancer following initial and chronic dosing at twice daily 10 mg/m2 or a 20 mg/m2 single dose. Median time to response was six weeks. Blood tamoxifen levels at that time were ten-fold greater than those obtained after an initial single dose; however, steady-state values were not achieved until 16 weeks of chronic dosing. On a loading dose schedule of 40 mg/m2 twice daily for seven days and 20 mg/m2 daily thereafter, blood levels greater than or equal to 10 mg/m2 twice daily steady-state values were reached in one week. Levels drawn at peak and trough times suggest that tamoxifen may be given on a once-daily basis. Tamoxifen half-life was 9-12 hours after the initial dose and seven days after chronic dosing.