Melosira nummuloides Ethanol Extract Ameliorates Alcohol-Induced Liver Injury by Affecting Metabolic Pathways

Melosira nummuloides is a microalga with a nutritionally favorable polyunsaturated fatty acid profile. In the present study, M. nummuloides ethanol extract (MNE) was administered to chronic-binge alcohol-fed mice and alcohol-treated HepG2 cells, and its hepatoprotective effects and underlying mechanisms were investigated. MNE administration reduced triglyceride (TG), total cholesterol (T-CHO), and liver injury markers, including aspartate transaminase (AST) and alanine transaminase (ALT), in the serum of chronic-binge alcohol-fed mice. However, MNE administration increased the levels of phosphorylated adenosine monophosphate-activated protein kinase (P-AMPK/AMPK) and PPARα, which was accompanied by a decrease in SREBP-1; this indicates that MNE can inhibit adipogenesis and improve fatty acid oxidation. Moreover, MNE administration upregulated the expression of antioxidant enzymes, including SOD, NAD(P)H quinone dehydrogenase 1, and GPX, and ameliorated alcohol-induced inflammation by repressing the Akt/NFκB/COX-2 pathway. Metabolomic analysis revealed that MNE treatment modulated many lipid metabolites in alcohol-treated HepG2 cells. Our study findings provide evidence for the efficacy and mechanisms of MNE in ameliorating alcohol-induced liver injury.

A synergistic two-drug therapy specifically targets a DNA repair dysregulation that occurs in p53-deficient colorectal and pancreatic cancers

The tumor-suppressor p53 is commonly inactivated in colorectal cancer and pancreatic ductal adenocarcinoma, but existing treatment options for p53-mutant (p53Mut) cancer are largely ineffective. Here, we report a therapeutic strategy for p53Mut tumors based on abnormalities in the DNA repair response. Investigation of DNA repair upon challenge with thymidine analogs reveals a dysregulation in DNA repair response in p53Mut cells that leads to accumulation of DNA breaks. Thymidine analogs do not interrupt DNA synthesis but induce DNA repair that involves a p53-dependent checkpoint. Inhibitors of poly(ADP-ribose) polymerase (PARPis) markedly enhance DNA double-strand breaks and cell death induced by thymidine analogs in p53Mut cells, whereas p53 wild-type cells respond with p53-dependent inhibition of the cell cycle. Combinations of trifluorothymidine and PARPi agents demonstrate superior anti-neoplastic activity in p53Mut cancer models. These findings support a two-drug combination strategy to improve outcomes for patients with p53Mut cancer.

Comparison of cell response to chromatin and DNA damage

DNA-targeting drugs are widely used for anti-cancer treatment. Many of these drugs cause different types of DNA damage, i.e. alterations in the chemical structure of DNA molecule. However, molecules binding to DNA may also interfere with DNA packing into chromatin. Interestingly, some molecules do not cause any changes in DNA chemical structure but interfere with DNA binding to histones and nucleosome wrapping. This results in histone loss from chromatin and destabilization of nucleosomes, a phenomenon that we call chromatin damage. Although the cellular response to DNA damage is well-studied, the consequences of chromatin damage are not. Moreover, many drugs used to study DNA damage also cause chromatin damage, therefore there is no clarity on which effects are caused by DNA or chromatin damage. In this study, we aimed to clarify this issue. We treated normal and tumor cells with bleomycin, nuclease mimicking drug which cut predominantly nucleosome-free DNA and therefore causes DNA damage in the form of DNA breaks, and CBL0137, which causes chromatin damage without direct DNA damage. We describe similarities and differences between the consequences of DNA and chromatin damage. Both agents were more toxic for tumor than normal cells, but while DNA damage causes senescence in both normal and tumor cells, chromatin damage does not. Both agents activated p53, but chromatin damage leads to the accumulation of higher levels of unmodified p53, which transcriptional activity was similar to or lower than that of p53 activated by DNA damage. Most importantly, we found that while transcriptional changes caused by DNA damage are limited by p53-dependent activation of a small number of p53 targets, chromatin damage activated many folds more genes in p53 independent manner.

Antiadipogenic Effect of Citrus Flavonoids: Evidence from RNA Sequencing Analysis and Activation of AMPK in 3T3-L1 Adipocytes

Citrus fruits are rich in dietary flavonoids and have many health benefits, but their antiadipogenic mechanism of action and their impact on lipid metabolism remain unclear. In this study, we investigated the effect of citrus flavonoids, namely, hesperidin (HES), narirutin (NAR), nobiletin (NOB), sinensetin (SIN), and tangeretin (TAN), on preventing fat cell development by gene expression in 3T3-L1 adipocytes. Among the citrus flavonoids tested, HES and NAR significantly reduced fat storage and triglyceride levels and increased glucose uptake in 3T3-L1 adipocytes. Additionally, HES and NAR treatment increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) while reducing the protein expression of 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR). Furthermore, in silico docking revealed that flavonoids activate AMPK. RNA sequencing analysis demonstrated that citrus flavonoids normalized the expression of 40 genes, which were either upregulated by more than 2-fold or downregulated by less than 0.6-fold including Acadv1, Acly, Akr1d1, Awat1, Cyp27a1, Decr1, Dhrs4, Elovl3, Fasn, G6pc, Gba, Hmgcs1, Mogat2, Lrp5, Sptlc3, and Snca to levels comparable to the control group. Altogether, HES and NAR among five citrus flavonoids showed antiadipogenic effects by regulating the expression of specific lipid metabolism genes partially restored to control levels in 3T3-L1 cells.

Abstract 73: Blockade of p38 MAPK reduces the tumor-induced immune suppressive microenvironment in metastatic breast cancer

The ability of CD8+ T cells to mount an anti-tumor immune response is compromised by immune suppression in the tumor microenvironment (TME). Tumor Associated Macrophages (TAMs) and Myeloid Derived Suppressor Cells (MDSCs) are a major part of this immune suppressive network. Targeting these populations remains challenging. Previously, we have reported that pharmacological and genetic blockade of p38 MAPK impeded the expansion and mobilization of monocytic and granulocytic MDSCs in mouse mammary carcinoma models. We also found that blockade of p38 or depletion of MDSCs reduced tumor growth and metastasis while enhancing the levels of CD8+ T cells in the primary tumors. In the present study, we asked whether CD8+ T cells contribute to the anti-metastatic activity of p38 inhibitor (p38i) and how p38 blockade affects the functional status of T cells and MDSCs. By using the mouse mammary carcinoma 4T1 model, we found that depletion of CD8+ T cells negated the effects of p38i on tumor growth and metastasis, indicating that CD8+ T cells contribute to the anti-tumor and anti-metastatic effects of p38 blockade. Next, we examined whether p38i exhibits a direct effect on T cells. The results of the T cell proliferation in vitro assays revealed that p38 blockade did not have a direct impact on T cell proliferation in response to αCD3/αCD28 stimulation. To determine the effect of p38 blockade on T cells in vivo, we performed single cell RNA-seq on the 4T1 tumor models treated with p38i and the 4T1 model with p38α (Mapk14) knockout (p38ko). This study revealed that p38 blockade by p38i or by inactivation of p38 in tumor cells decreased the amount of exhausted T cells and increased Th1 cells in the TME, indicating a positive effect on T cell functions. Furthermore, we observed a significant decrease in inflammatory signaling in granulocytes and monocytes upon p38 blockade. Our previous study showed that p38i did not affect generation of MDSCs in vitro in response to G-CSF & GM-CSF. To determine whether p38i alters MDSCs in vivo, we assessed MDSC gene signature in monocytic and granulocytic MDSCs isolated from spleens of tumor-bearing mice subjected to p38 blockade. This work revealed that the MDSC gene signature was reduced in both p38i and p38ko groups compared to tumor bearing mice treated with vehicle-control. These results indicated a reduction in the MDSC generation in the in vivo model. Our study revealed that blockade of p38 reduces tumor induced immune suppression and may enhance anti-tumor immune response in metastatic breast cancer.

Citation Format: Priyanka Rajan, Justin Zonneville, Robert Zollo, Mackenzie Honikel, Sofija Raudins, Sean Colligan, Brian Morreale, Mohammed Alruwaili, Mohammed Alqarni, Scott Olejniczak, Joseph Barbi, Scott Abrams, Andrei Bakin. Blockade of p38 MAPK reduces the tumor-induced immune suppressive microenvironment in metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 73.

Abstract 3397: Evaluation of a novel two-drug combination strategy for p53-deficient colorectal and pancreatic cancers

Colorectal Cancer (CRC) and Pancreatic Ductal Adenocarcinoma (PDAC) are the most lethal cancers worldwide. Despite initial response to standard-of-care therapy, a significant proportion of CRC/PDAC cancers relapse and progress to metastatic disease with poor overall survival (OS). Thus, better treatment options are urgently needed. Genetic alterations in the tumor suppressor p53 gene (TP53) are found in most CRC and PDAC cases and contribute to cancer relapse, progression, and metastasis. Even though the functional consequences of p53 mutations have been extensively studied, there are no FDA approved drug or their combination targeting p53 mutant (p53mut) cancers. Here we present a novel inducer-amplifier strategy for selective targeting p53-deficient CRC and PDAC. The Cancer Genome Atlas (TCGA) data showed elevated tumor mutational burden (TMB) and high expression levels of Base-Excision Repair (BER) in p53mut CRC and PADC. Assessment of the BER activity in CRC and PADC cells by a new methodology with deoxyuridine analogues ethynyl-deoxyuridine (EdU) and trifluorothymidine (TFT) revealed a significant delay in removal of genomic EdU and TFT in p53-deficient cells compared to isogenic p53 wildtype (p53wt) cells. Notably, p53-deficient cells accumulated in late S/G2 phase. Further, deoxyuridine analogues such as TFT-containing TAS102 induced buildup of DNA damage in p53-deficient cancer cells. Mechanistically, TAS102 did not block DNA replication but rather provoked activation of DNA Damage Response (DDR) resulting in DNA breaks in p53-deficient cells, while p53wt repaired the DNA lesion. This response was further enhanced by poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) leading to elevated cell death selectively in p53-deficient cancer cells, along with accumulation of cells in G2 phase. PARPi alone did not induce DNA damage in cancer cells. In preclinical in vivo models, the TAS102-PARPi combination was far more effective than either drug alone in the p53mut Cell-Derived Xenograft (CDX) and Patient-Derived xenograft (PDX) models. Immunohistochemistry data showed that the two-drug combination increased DNA damage and cell death while decreasing cell proliferation in p53-mutant models. In comparison, the two-drug combination and TAS102 exhibited comparable effectiveness in p53wt PDX model. Notably, the two-drug therapy did not exhibit significant toxicity in mouse models. In summary, this work demonstrates that our novel inducer-amplifier strategy provides effective treatment option for aggressive p53-deficient CRC and PDAC cancers while limiting adverse toxic events and improving the quality of life for cancer patients.

Citation Format: Mohammed M. Alruwaili, Justin Zonneville, Mohammed A. Alqarni, Priyanka Rajan, Hannah Serio, Robert Straubinger, Christos Fountzilas, Andrei Bakin. Evaluation of a novel two-drug combination strategy for p53-deficient colorectal and pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3397.

Effects of Cudrania tricuspidata and Sargassum fusiforme extracts on hair growth in C57BL/6 mice

BACKGROUND

Cudrania tricuspidata is a perennial plant, and Sargassum fusiforme is a brown seaweed with numerous potential benefits, including anticancer, anti-inflammatory, and antioxidant activities. However, the efficacies of C. tricuspidata and S. fusiforme on hair growth have not yet been elucidated. Therefore, the present study examined the effects of C. tricuspidata and S. fusiforme extracts on hair growth in C57BL/6 mice.

RESULTS

ImageJ demonstrated that drinking and skin application of C. tricuspidata and/or S. fusiforme extracts significantly increased the hair growth rate in the dorsal skin of C57BL/6 mice compared to the control group. Histological analysis confirmed that drinking and skin application of C. tricuspidata and/or S. fusiforme extracts for 21 days significantly increased the length of hair follicles on the dorsal skin of treated C57BL/6 mice compared to that in the control mice. RNA sequencing analysis revealed that hair growth cycle-related factors (anagen factors) such as Catenin Beta 1 (Ctnnb1) and platelet-derived growth factor (Pdgf) were upregulated (> twofold) only by C. tricuspidate extracts, whereas vascular endothelial growth factor (Vegf) and Wnts were upregulated by both C. tricuspidata or S. fusiforme applications in treated mice (compared to the control mice). In addition, oncostatin M (Osm, a catagen-telogen factor) was downregulated (< 0.5 fold) by C. tricuspidata when administered via both skin and drinking mode in treated mice compared to that in control mice.

CONCLUSIONS

Our results suggest that C. tricuspidata and/or S. fusiforme extracts show potential hair growth efficacy by upregulating anagen factor genes, including β-catenin, Pdgf, Vegf, and Wnts, and downregulating catagen-telogen factor genes, including Osm, in C57BL/6 mice. The findings suggest that C. tricuspidata and/or S. fusiforme extracts are potential drug candidates to treat alopecia.

Comparison of cell response to chromatin and DNA damage

DNA-targeting drugs may damage DNA or chromatin. Many anti-cancer drugs damage both, making it difficult to understand their mechanisms of action. Using molecules causing DNA breaks without altering nucleosome structure (bleomycin) or destabilizing nucleosomes without damaging DNA (curaxin), we investigated the consequences of DNA or chromatin damage in normal and tumor cells. As expected, DNA damage caused p53-dependent growth arrest followed by senescence. Chromatin damage caused higher p53 accumulation than DNA damage; however, growth arrest was p53-independent and did not result in senescence. Chromatin damage activated the transcription of multiple genes, including classical p53 targets, in a p53-independent manner. Although these genes were not highly expressed in basal conditions, they had chromatin organization around the transcription start sites (TSS) characteristic of most highly expressed genes and the highest level of paused RNA polymerase. We hypothesized that nucleosomes around the TSS of these genes were the most sensitive to chromatin damage. Therefore, nucleosome loss upon curaxin treatment would enable transcription without the assistance of sequence-specific transcription factors. We confirmed this hypothesis by showing greater nucleosome loss around the TSS of these genes upon curaxin treatment and activation of a p53-specific reporter in p53-null cells by chromatin-damaging agents but not DNA-damaging agents.

Abstract B039: Development of a selective therapeutic intervention for p53 mutant for pancreatic adenocarcinoma

Genetic alterations in the tumor suppressor p53 gene (TP53) are found in over 70% of Pancreatic Adenocarcinoma (PAAD) and contribute to poor prognosis, cancer progression and metastasis. Existing treatment options for p53 mutant (p53mut) cancer are limited and there is an urgent need for better therapeutic interventions that can be greatly beneficial to a large proportion of patients with PAAD. Here we present a novel therapeutic strategy for selective targeting p53mut pancreatic tumors. Genomic data revealed that p53-deficient PAADs express high levels of DNA replication genes as well as genes involved in Base Excision (BER) and Mismatch (MMR) Repair, indicating activation of these mechanisms. Evaluation of BER activity by a novel methodology with a modified deoxyuridine analogue showed a significant dysregulation in BER mediated repair in p53mut cancer cells leading to accumulation of p53mut tumor cells in late S/G2 phase. By exploiting this defect, we found that treatment with a deoxyuridine analogue such as trifluorothymidine (TFT, a component of TAS102) resulted in accumulation of DNA breaks selectively in p53mut cells. A deoxyuridine analogue (TFT) did not block DNA replication but rather activated DNA repair leading to DNA breaks in p53mut cells whereas p53 wild type cells accumulated in G1 with minimal DNA damage. Further, we found that inhibition of poly (ADP) ribose polymerase (PARP) enhanced DNA damage and increased cell death selectively in p53mut tumor cells although PARP inhibitor alone was not effective. In contrast, the TAS102-PARPi did not induce DNA damage in the normal cells such as hTERT-immortalized Human Pancreatic Nestin Expressing cells (HPNE). A new TAS102-PARPi combination regimen demonstrated greater inhibition of tumor growth and improved the survival rates in p53mut PAAD xenograft models including Cell-Derived Xenograft (CDX) and Patient-Derived xenograft (PDX) models, compared to either drug alone without adverse effects in mice. Thus, this preclinical work identified a novel and immediately feasible strategy for p53mut disease that may improve treatment and the quality of life for a significant proportion of patients with PAAD while limiting toxic effects on normal tissues.

Citation Format: Mohammed M. Alruwaili, Justin Zonneville, Mohammed A. Alqarni, Priyanka Rajan, Hannah Serio, Robert Straubinger, Christos Fountzilas, Andrei Bakin. Development of a selective therapeutic intervention for p53 mutant for pancreatic adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B039.

171 Developing & Centralising a Nurse-Led Local Anaesthetic (La) Transperineal (Tp) Biopsy Service During Covid: A Success Story

Introduction

During the first COVID-19 wave, the BAUS Section of Oncology issued guidance to minimise risks of sepsis and general anaesthesia at prostate biopsy. Consequently, and as a result of diminished diagnostics capacity on Trust acute sites, we implemented a centralised network-wide nurse-led LA TP biopsy service on a COVID-secure “green” site and abandoned trans-rectal biopsies. We evaluated the impact of this service improvement on patient waiting times before and after national lockdown in March 2020.

Method

Classic Quality Improvement (QI) methodology was used with continuous data collection and waiting list management by clinical staff with standard admin support. Balancing measurements were collected. Run charts were used to confirm whether a change led to a real and sustainable improvement.

Results

The number of days waiting, from time of request to date of biopsy, is presented in the following run chart. The mean waiting time for those pre lockdown was 145 days (SD 57) whereas post lockdown was 23 days (SD 20). This identified that there was a significant difference between the average waiting time pre and post lockdown (U = 55.5, p = <0.001) There were also reductions in waiting time when subcategorised into planned Active Surveillance cases, target cases and delayed cases.

Conclusions

Centralising the TP biopsy service and converting to a nurse led LA service has led to reductions in waiting lists and was safely expedited and resilient even in the COVID-19 pandemic. Allowing a second advanced TP practitioner to be fully trained, during COVID. The service was highly valued by patients and staff.

Abstract P5-17-06: P38 kinase as a therapeutic target to reverse an immune suppressive tumor microenvironment in metastatic breast cancer

The immune suppressive tumor microenvironment (TME) in metastatic breast cancer (MBC) limits the benefits of immunotherapy with immune checkpoint inhibitors (ICIs). In particular, the primary TME drives the expansion and recruitment of immune suppressive myeloid cell populations, such as tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs). Treatments targeting these populations can potentially improve the efficacy of ICI therapy. To that end, our published and new findings have revealed that the p38 Mitogen-Activated Protein Kinase (MAPK) contributes to the expansion and mobilization of TAMs and MDSCs. Further, we found that pharmacological blockade of p38 decreased metastasis and increased the levels of CD8+ T cells while decreasing TAMs in the primary TME. Depletion of PMN-MDSCs, a major MDSC subset, was accompanied by reduced TAM infiltration and phenocopied the anti-metastatic effects of p38 blockade. Next, we explored the impact of p38 blockade on the composition and functionality of the immune populations in the primary TME by using single-cell RNA-sequencing. We found that p38 blockade increased levels of Irf8+ monocytic populations, indicating a decrease in immune-suppressive properties of the TME. Notably, p38 blockade increased the expression of factors related to the activation of CD8+ cytotoxic T lymphocytes, i.e., Jchain, Icos, and Cd137. Thus, our data indicate that p38 blockade alters the immune landscape within the primary TME and favors an antitumor immune response. Our data also suggest that the p38 kinase controls the production of tumor-derived factors (TDFs) which facilitate the recruitment of those pro-tumor myeloid populations. Thus, we explored this p38-TDF-myeloid axis by using trans-well migration assays. We tested the migration of the monocyte-like cell line RAW 264.7 in response to tumor-conditioned media prepared from tumor cells treated with or without the p38 inhibitor, Ralimetinib. Our data showed that the migration of RAW 264.7 cells was significantly diminished towards the conditioned media from tumor cells treated with the p38 inhibitor or from tumor cells with a genetic inactivation of p38α by CRISPR/Cas9 compared to the corresponding controls. Altogether, our studies demonstrate that p38 kinase is a potential therapeutic target, which reshapes the immune suppressive contexture of TME in MBC to improve antitumor immunity.

Citation Format: Priyanka Rajan, Justin Zonneville, Sean Colligan, Scott Abrams, Andrei Bakin. P38 kinase as a therapeutic target to reverse an immune suppressive tumor microenvironment in metastatic 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 P5-17-06.

Anti-adipogenic effect of the flavonoids through the activation of AMPK in palmitate (PA)-treated HepG2 cells

BACKGROUND

Flavonoids are natural polyphenols found widely in citrus fruit and peel that possess anti-adipogenic effects. On the other hand, the detailed mechanisms for the anti-adipogenic effects of flavonoids are unclear.

OBJECTIVES

The present study observed the anti-adipogenic effects of five major citrus flavonoids, including hesperidin (HES), narirutin (NAR), nobiletin (NOB), sinensetin (SIN), and tangeretin (TAN), on AMP-activated protein kinase (AMPK) activation in palmitate (PA)-treated HepG2 cells.

METHODS

The intracellular lipid accumulation and triglyceride (TG) contents were quantified by Oil-red O staining and TG assay, respectively. The glucose uptake was assessed using 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) assay. The levels of AMPK, acetyl-CoA carboxylase (ACC), and glycogen synthase kinase 3 beta (GSK3β) phosphorylation, and levels of sterol regulatory element-binding protein 2 (SREBP-2) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) expression were analyzed by Western blot analysis. The potential interaction between the flavonoids and the γ-subunit of AMPK was investigated by molecular docking analysis.

RESULTS

The flavonoid treatment reduced both intracellular lipid accumulation and TG content in PA-treated HepG2 cells significantly. In addition, the flavonoids showed increased 2-NBDG uptake in an insulin-independent manner in PA-treated HepG2 cells. The flavonoids increased the AMPK, ACC, and GSK3β phosphorylation levels and decreased the SREBP-2 and HMGCR expression levels in PA-treated HepG2 cells. Molecular docking analysis showed that the flavonoids bind to the CBS domains in the regulatory γ-subunit of AMPK with high binding affinities and could serve as potential AMPK activators.

CONCLUSION

The overall results suggest that the anti-adipogenic effect of flavonoids on PA-treated HepG2 cells results from the activation of AMPK by flavonoids.

The effects of naringenin and naringin on the glucose uptake and AMPK phosphorylation in high glucose treated HepG2 cells

Background

Naringin and its aglycone naringenin are citrus-derived flavonoids with several pharmacological effects. On the other hand, the mechanism for the anti-diabetic effects of naringenin and naringin are controversial and remain to be clarified further.

Objective

This study examined the relationship between glucose uptake and AMP-activated protein kinase (AMPK) phosphorylation by naringenin and naringin in high glucose-treated HepG2 cells.

Methods

Glucose uptake was measured using the 2-NBDG fluorescent D-glucose analog. The phosphorylation levels of AMPK and GSK3β (Glycogen synthase kinase 3 beta) were observed by Western blotting. Molecular docking analysis was performed to evaluate the binding affinity of naringenin and naringin to the γ-subunit of AMPK.

Results

The treatment with naringenin and naringin stimulated glucose uptake regardless of insulin stimulation in high glucose-treated HepG2 cells. Both flavonoids increased glucose uptake by promoting the phosphorylation of AMPK at Thr172 and increased the phosphorylation of GSK3β. Molecular docking analysis showed that both naringenin and naringin bind to the γ-subunit of AMPK with high binding affinities. In particular, naringin showed higher binding affinity than the true modulator, AMP with all three CBS domains (CBS1, 3, and 4) in the γ-subunit of AMPK. Therefore, both naringenin and naringin could be positive modulators of AMPK activation, which enhance glucose uptake regardless of insulin stimulation in high glucose-treated HepG2 cells.

Conclusions

The increased phosphorylation of AMPK at Thr172 by naringenin and naringin might enhance glucose uptake regardless of insulin stimulation in high glucose treated HepG2 cells.

Comparative Effectiveness Analyses of Salvage Prostatectomy and Salvage Radiotherapy Outcomes Following Focal or Whole-Gland Ablative Therapy (High-Intensity Focused Ultrasound, Cryotherapy or Electroporation) for Localised Prostate Cancer

AIMS

Ablative therapy, such as focal therapy, cryotherapy or electroporation, aims to treat clinically significant prostate cancer with reduced treatment-related toxicity. Up to a third of patients may require further local salvage treatment after ablative therapy failure. Limited descriptive, but no comparative, evidence exists between different salvage treatment outcomes. The aim of this study was to compare oncological and functional outcomes after salvage robot-assisted radical prostatectomy (SRARP) and salvage radiotherapy (SRT).

MATERIALS AND METHODS

Data were collected prospectively and retrospectively on 100 consecutive SRARP cases and 100 consecutive SRT cases after ablative therapy failure in a high-volume tertiary centre.

RESULTS

High-risk patients were over-represented in the SRARP group (66.0%) compared with the SRT group (48.0%) (P = 0.013). The median (interquartile range) follow-up after SRARP was 16.5 (10.0-30.0) months and 37.0 (18.5-64.0) months after SRT. SRT appeared to confer greater biochemical recurrence-free survival at 1, 2 and 3 years compared with SRARP in high-risk patients (year 3: 86.3% versus 66.0%), but biochemical recurrence-free survival was similar for intermediate-risk patients (year 3: 90.0% versus 75.6%). There was no statistical difference in pad-free continence at 12 and 24 months between SRARP (77.2 and 84.7%) and SRT (75.0 and 74.0%) (P = 0.724, 0.114). Erectile function was more likely to be preserved in men who underwent SRT. After SRT, cumulative bowel and urinary Radiation Therapy Oncology Group toxicity grade I were 25.0 and 45.0%, grade II were 11.0 and 11.0% and grade III or IV complications were 4.0 and 5.0%, respectively.

CONCLUSION

We report the first comparative analyses of salvage prostatectomy and radiotherapy following ablative therapy. Men with high-risk disease appear to have superior oncological outcomes after SRT; however, treatment allocation does not appear to influence oncological outcomes for men with intermediate-risk disease. Treatment allocation was associated with a different spectrum of toxicity profile. Our data may inform shared decision-making when considering salvage treatment following focal or whole-gland ablative therapy.

Anti-obesity effect of sulforaphane in broccoli leaf extract on 3T3-L1 adipocytes and ob/ob mice

The present study evaluated the anti-obesity effect of sulforaphane (SFN) and glucoraphanin (GRN) in broccoli leaf extract (BLE) on 3T3-L1 adipocytes and ob/ob mice. Based on Oil Red O staining and triglyceride (TG) assay, SFN and BLE significantly reduced (P<.05) both lipid accumulation and TG content in the differentiated 3T3-L1 adipocytes. SFN and BLE increased 2-NBDG uptake by 3T3-L1 adipocytes in a dose-dependent manner. Western blot analysis confirmed that SFN and BLE increased the phosphorylation levels of both AMPK (Thr172) and ACC (Ser79), and reduced the expression of HMGCR in liver and white adipose tissues of ob/ob mice. Histological analysis revealed that SFN and BLE ameliorated hepatic steatosis, and reduced the size of adipocyte in ob/ob mice. Treatment with SFN and BLE significantly reduced (P<.05) TG content, low-density lipoprotein (LDL) cholesterol, total cholesterol (TC), and glucose in the serum of ob/ob mice. RNA sequencing analysis showed that up- or down-regulation of 32 genes related to lipid metabolism was restored to control level in both SFN and BLE-treated ob/ob mice groups. A protein-protein interaction (PPI) network was constructed via STRING analysis, and Srebf2, Pla2g2c, Elovl5, Plb1, Ctp1a, Lipin1, Fgfr1, and Plcg1 were located in the functional hubs of the PPI network of lipid metabolism. Overall results suggest that the SFN content in BLE exerts a potential anti-obesity effect by normalizing the expression of genes related to lipid metabolism, which are up- or down-regulated in ob/ob mice.

141 New Guidelines to Reduce Unnecessary Blood Tests, Delayed Discharge and Costs Following Robot Assisted Radical Prostatectomy

Objectives

Routine postoperative blood tests (POBT) following robot assisted radical prostatectomy (RARP) are used to evaluate the impact of surgery on pre-existing co-morbidities and to detect early complications. This practice dates back to an era of open surgery, when blood loss and complication rates were higher. We propose new guidelines to improve the specificity of POBT.

Method

The cases of 1040 consecutive patients who underwent a primary or salvage RARP at two large tertiary urology centres in the United Kingdom were retrospectively reviewed to form new guidelines. The new guidelines were prospectively validated in a sample of 300 patients.

Results

Derivation Dataset: 3% and 5% had intra- and post-operative Clavien-Dindo complications, respectively. 15% had clinical concerns postoperatively. 0.9% required perioperative transfusion. 78% had routine blood tests without clinical concerns, none of whom developed a complication. 98% of complications were suspected by clinical judgement. 6% of patients had a discharge delay of ≥ 1 day due to delayed or incomplete blood tests. Validation Dataset: No significant difference existed in complication, clinical concern or transfusion rates between the derivation and validation datasets. Number of POBT requested reduced by 73% (p &lt; 0.001). The new guidelines improved POBT sensitivity for complications from 98% to 100% and specificity from 0% to 74%. Discharge delays reduced from 6% to 0% (p = 0.008). Cost savings were £178 per patient.

Conclusions

Postoperative complications and transfusion following RARP are rare. Routine POBT without clinical indication are unnecessary and inefficient. A guideline-based approach to POBT can reduce costs and optimise discharge without compromising patient safety or care.

283 Salvage Versus Primary Robot-Assisted Radical Prostatectomy: A Propensity-Matched Comparative Effectiveness Study from A High-Volume Tertiary Centre

Aim

Salvage Robot-Assisted Radical Prostatectomy (sRARP) is a potential treatment option for locally recurrent Prostate Cancer after non-surgical primary treatment. There are minimal data comparing outcomes between propensity-matched salvage and primary Robot-Assisted Radical Prostatectomy (RARP). We compare perioperative, oncological, and functional outcomes of sRARP with primary RARP and between sRARP post-whole and focal gland therapy.

Method

1:1 propensity-matched comparison of 146 sRARP with primary RARP from a cohort of 3,852 consecutive patients from a high-volume tertiary centre.

Results

There were no significant differences in patient characteristics between the salvage and primary RARP groups. Grade III-V Clavien-Dindo complication rates were 1.3% and 0% in the salvage and primary groups, respectively (p = 0.310). Median (IQR) follow-up was 16 (10,30) and 21 (13,33) months in the salvage and primary groups, respectively. BCR rates were 30.8% and 13.7% in the salvage and primary groups, respectively (p &lt; 0.001). Pad-free continence rates were 79.1% and 85.4% at two years in the salvage and primary groups, respectively (p = 0.160). ED rates were 95.2% and 77.4% in the salvage and primary groups, respectively (p &lt; 0.001). Comparing the whole gland and focal gland groups, BCR rates were 33.3% and 29.1%, respectively (p = 0.687), pad-free continence rates were 66% and 89.3%, respectively (p = 0.001), and ED rates were 98.3% and 93%, respectively (p = 0.145).

Conclusions

SRARP has similar perioperative but inferior oncological outcomes to primary RARP. Continence rates are similar to primary RARP, but potency is worse. Perioperative and oncological outcomes of sRARP after focal gland therapy are similar but continence outcomes are superior compared to sRARP after whole gland therapy.

Challenges faced by Otorhinolaryngology (ORL) services, Malaysia, in the current pandemic

No abstract provided.

Otorhinolaryngology services at a district hospital in Sabah, Malaysia during the COVID-19 Pandemic

No abstract provided.

O50 New guidelines to reduce unnecessary blood tests, delayed discharge and costs following robot assisted radical prostatectomy

Introduction

Routine postoperative blood tests (POBT) are used to evaluate the impact of surgery on pre-existing co-morbidities and to detect early complications. This practice dates back to an era of open surgery, when blood loss and complication rates were higher. We propose new guidelines to improve the specificity of POBT.

Method

The cases of 1040 consecutive patients who underwent a primary or salvage RARP at two large tertiary urology centres in the United Kingdom were retrospectively reviewed, and new guidelines were designed. The guidelines were prospectively validated in a cohort of 300 patients.

Result

Derivation Dataset 3% and 5% had intra- and post-operative Clavien-Dindo complications, respectively. 15% had clinical concerns postoperatively. 0.9% required perioperative transfusion. 78% had routine blood tests without clinical concerns, none of whom developed a complication. 98% of complications were suspected by clinical judgement. 6% of patients had a discharge delay of ≥ 1 days due to delayed or incomplete blood tests.

Validation Dataset No significant difference existed in complication, clinical concern or transfusion rates between the derivation and validation datasets. New guidelines improved sensitivity for complications from 98% to 100% and specificity from 0% to 74%. The number of blood tests requested reduced by 73% (P &lt; 0.001). Discharge delays reduced from 6% to 0% (P = 0.008). Cost savings were £178 per patient.

Conclusion

Postoperative complications and transfusion following RARP are rare. Routine POBT without clinical indication are unnecessary and inefficient. A guideline-based approach to POBT can reduce costs and optimise discharge without compromising patient safety or care.

Take-home Message

Routine postoperative blood tests following robot assisted radical prostatectomy are often unnecessary. A guideline-based approach can reduce costs and optimise patient care.

236 Novel Guidelines to Avoid Routine Blood Tests After Robotic Assisted Radical Prostatectomy (RARP)

Introduction

Patients undergoing RARP commonly require routine post-operative blood tests. This practice dates from an era of open surgery, with increased blood loss and complications. We aim to improve specificity of blood test requests with novel guidelines.

Method

1039 consecutive RARP patients at two tertiary urology centres in the UK were audited. Novel guidelines constructed based on risk stratified evidence from the initial audit were used to prospectively audit 133 patients.

Results

16% had clinical concerns post-operatively. 1% and 4% had an intra- and post-operative complication. Intra- or post-operative clinical judgement flagged post-operative complications in 99.9%. 80% had routine blood tests with no clinical concerns. 6% had delayed discharge due to delayed processing of blood tests. 0.9% received a peri-operative transfusion.

Re-Audit Novel guidelines reduced the number of blood tests requested from 100% to 36%. Specificity in diagnosing a complication improved from 0% to 67%. Discharge delays reduced from 6% to 0% and no post-operative complications were missed (sensitivity 100%).

Conclusions

Routine blood tests, without an indication, did not flag any additional post-operative complications. Blood transfusion is rare for RARP. Novel guidelines to request post-operative blood tests will reduce costs and discharge delays whilst maintaining appropriate patient safety and care.

Restoration of the adipogenic gene expression by naringenin and naringin in 3T3-L1 adipocytes

Background

Naringenin and its glycoside naringin are well known citrus flavonoids with several therapeutic benefits. Although the anti-adipogenic effects of naringenin and naringin have been reported previously, the detailed mechanism underlying their anti-adipogenesis effects is poorly understood.

Objectives

This study examined the anti-adipogenic effects of naringenin and naringin by determining differential gene expression patterns in these flavonoids-treated 3T3-L1 adipocytes.

Methods

Lipid accumulation and triglyceride (TG) content were determined by Oil red O staining and TG assay. Glucose uptake was measured using a 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose fluorescent d-glucose analog. The phosphorylation levels of AMP-activated protein kinase (AMPK) and acetyl Co-A carboxylase (ACC) were observed via Western blot analysis. Differential gene expressions in 3T3-L1 adipocytes were evaluated via RNA sequencing analysis.

Results

Naringenin and naringin inhibited both lipid accumulation and TG content, increased phosphorylation levels of both AMPK and ACC and decreased the expression level of 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) in 3T3-L1 adipocytes. RNA sequencing analysis revealed that 32 up-regulated (> 2-fold) and 17 down-regulated (< 0.6-fold) genes related to lipid metabolism, including Acaca, Fasn, Scd1, Mogat1, Dgat, Lipin1, Cpt1a, and Lepr, were normalized to the control level in naringenin-treated adipocytes. In addition, 25 up-regulated (> 2-fold) and 25 down-regulated (< 0.6-fold) genes related to lipid metabolism, including Acaca, Fasn, Fabp5, Scd1, Srebf1, Hmgcs1, Cpt1c, Lepr, and Lrp1, were normalized to the control level by naringin.

Conclusions

The results indicate that naringenin and naringin have anti-adipogenic potentials that are achieved by normalizing the expression levels of lipid metabolism-related genes that were perturbed in differentiated 3T3-L1 cells.

0649 Ultrasound Assessment of Tongue Movement as a Predictor of Response to Hypoglossal Nerve Stimulation (HGNS)

Introduction

HGNS is an approved therapy for obstructive sleep apnea (OSA). Initial setting of HGNS voltage is based on observation of anterior tongue movement, which may not reflect opening of the retroglossal airway. We developed an ultrasonographic (US) technique to assess tongue movement with HGNS. We correlated US measures of tongue movement at the initial HGNS voltage setting with the AHI determined by PSG/HSAT on HGNS therapy.

Methods

Eleven subjects implanted with INSPIRE™ (HGNS) were enrolled at least one month post-implantation. Initial HGNS voltage was determined while awake and semi-recumbent and set to achieve visualized anterior tongue protrusion at a tolerable stimulation voltage. A curvilinear probe (5-2MHz) was placed longitudinally in the submental region at the midline with the indicator pointed anteriorly. Hyoid bone excursion (HBE) with stimulation was used as a marker of base of tongue movement. PSG or HSAT was performed to determine AHI with HGNS. Responders were defined as those with a reduction in AHI ≥50% and an AHI &lt;20 events/hr.

Results

N=11, 6M, 5F, Age=66.5 ±18.4 years, BMI=27.9±2.7 kg/m2. Pre-treatment AHI=38.8±13.4/hr, T-90%=10.5±16.7%. Mean HBE in responders=1.02±0.17cm vs 0.76±0.20cm in non-responders (p=0.006). Best subsets regression analysis performed using post-treatment AHI as the dependent variable and age, BMI, baseline AHI, HBE and HGNS voltage as independent variables showed that HBE (coef. -29.1, p=0.038) and BMI (coef. 2.6, p=0.018) were independent predictors of response.

Conclusion

We demonstrated that ultrasound assessment of HBE during HGNS may be a useful tool to predict response to therapy and guide HGNS settings. HBE, rather than voltage, predicted post-treatment AHI.

Support

None.

<b>Feasibility study on the vegetative propagation of four endemic rare balsams (<I>Impatiens</I> spp.) through stem cuttings for conservation and management in Idukki District, Kerala, India</b>

Ex situ conservation by vegetative propagation was successfully established in the endemic rare balsam species Impatiens anaimudica, I. elegans, I. disotis and I. phoenicea of the Western Ghats.  The experiment was done in an open environmental nursery at Munnar exposed to constant temperature (7–24 0C) and relative humidity (70–100 %) throughout the study period.  These favourable conditions provided a suitable platform for the establishment.  We observed a significant difference in the regeneration patterns of the four species.  I. elegans started to regenerate after the 10th day of planting with high success, while I. disotis showed a 30% success rate.  After maturation all species were transplanted to natural ecosystems.

Juvenile recurrent respiratory papillomatosis: A rare masquerade of asthma

Juvenile recurrent respiratory papillomatosis (JRRP) is a rare condition. The varied presentation of this condition predisposes to misdiagnosis and potential life-threatening airway obstruction. In this paper, we have reported a case of JRRP presenting as severe respiratory distress and consequently mistreated as asthmatic attack culminating in a near fatal acute airway obstruction.

Rendering-Based Video-CT Registration with Physical Constraints for Image-Guided Endoscopic Sinus Surgery

We present a system for registering the coordinate frame of an endoscope to pre- or intra- operatively acquired CT data based on optimizing the similarity metric between an endoscopic image and an image predicted via rendering of CT. Our method is robust and semi-automatic because it takes account of physical constraints, specifically, collisions between the endoscope and the anatomy, to initialize and constrain the search. The proposed optimization method is based on a stochastic optimization algorithm that evaluates a large number of similarity metric functions in parallel on a graphics processing unit. Images from a cadaver and a patient were used for evaluation. The registration error was 0.83 mm and 1.97 mm for cadaver and patient images respectively. The average registration time for 60 trials was 4.4 seconds. The patient study demonstrated robustness of the proposed algorithm against a moderate anatomical deformation.

High Frequency of Isolation of Antibiotic-Resistant Oral Viridans Streptococci from Children in Kuwait

Antimicrobial resistance among the Viridans group of streptococci (VGS) has emerged as a hindrance to effective antibiotic therapy. Our objective was to evaluate the prevalence of antibiotic-resistant VGS in healthy children. Plaque samples were collected from tooth and tongue surfaces of 102 healthy subjects. Serially diluted samples were inoculated onto BHI agar plates and Mitis Salivarius Agar (MSA) plates and incubated as appropriate. Representative colonies were identified to species level by standard methods. Susceptibility of the VGS was performed by determining the minimum inhibitory concentrations (MICs) of 11 antibiotics using Etest. Of the 540 VGS isolates from both sites, 58% were from the tooth surfaces and 42% from the tongue. The most prevalent were S. salivarius (21.5%) and S. sanguis (16.3%). Imipenem and vancomycin had excellent activities. Resistance rates to trimethoprim, amoxicillin, piperacillin, erythromycin, cefuroxime and cephalothin, were 60.7, 40.8, 34.7, 32.6, 27.5 and 25.3%, respectively. Resistance rates to penicillin and clindamycin were 15.9% and 15.4%, respectively. The majority of the erythromycin-resistant isolates were from the tongue; 41% versus 29%. At the species level, 26% and 23% of S. salivarius and 23% and 14% of S. mutans from the tooth and tongue, respectively were resistant to penicillin. The data show species-related and site-related variations in the susceptibility pattern and an emerging high prevalence of antibiotic-resistant VGS. The difference in the susceptibilities between the species underscores the importance of accurate-identification and the need for surveillance of antimicrobial resistance among clinical isolates in our hospitals.

Abstract P1-02-01: Flat epithelial atypia diagnosed on breast core biopsy: what next?

Background: Historically, atypical ductal hyperplasia (ADH) identified on breast core biopsy has been associated with a 20% upgrade to malignancy at surgical excision. Recent literature has suggested a downward trend in such upgrade rates, possibly related to the use of larger gauge core biopsy devices. It is still unclear if this applies to other high-risk lesions, such as flat epithelial atypia (FEA). As core biopsy techniques and imaging have improved, it is critical to review the correlation between FEA diagnosed on core biopsy and malignancy at final surgical excision.

Methods: We performed a retrospective chart review of our institution's medical record from 2009 to 2011 to identify all patients who (1) underwent breast core biopsy, (2) were initially diagnosed with FEA without malignancy (in situ or invasive carcinoma), and (3) proceeded with surgical excision at our institution.

Results: Of the 726 breast core biopsies performed between 2009 and 2011, we identified 14 patients who met our inclusion criteria. Three patients were upgraded to malignancy following surgical excision (21%). The median age was 53.5 years, and the average breast cancer risk assessment scores were 3.5% 5-year and 18.9% lifetime. All patients underwent pre-biopsy mammogram, and four were further evaluated with ultrasound; no patients underwent a breast MRI. All of the imaging abnormalities were initially classified as BI-RADS 4, including five masses/densities and nine with suspicious calcifications. Only one patient reported the lesion as palpable on presentation and this was eventually upgraded to malignancy. All patients underwent image-guided core biopsies, including 13 stereotactic, vacuum-assisted and one ultrasound-guided, vacuum-assisted. Nine patients had 9-gauge core needle biopsies, while the remaining four patients had 11, 12, or 14-gauge needle biopsies, and this did not vary between years. Following surgical excision, three of the 14 patients (21%) were upgraded pathologically to ductal carcinoma in situ (DCIS; n=1) or invasive ductal carcinoma (n = 2). All three of these patients had 9-gauge core biopsies prior to surgical excision. Of note, four patients also had concurrent ADH on initial biopsy, although none of these were pathologically upgraded to malignancy. Of the upgrades, one patient proceeded with a definitive lumpectomy (negative sentinel lymph node biopsy) and one underwent bilateral mastectomy. The third patient is planning to undergo ipsilateral mastectomy for a subsequent diagnosis of multi-centric breast disease, including identification of an ipsilateral DCIS lesion distant from the primary lesion.

Conclusions: The use of a larger gauge core biopsy needle (e.g. 9-gauge) may yield superior tissue sampling and should likely be considered as the standard of care in the evaluation of image-detected breast abnormalities. In addition, biopsy results should not be considered definitively non-malignant when a high-risk lesion is identified. While there may be a trend towards not excising some of these high-risk lesions, we believe that a core biopsy demonstrating FEA still warrants surgical excision.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-02-01.

Teaching corner--"lumps and bumps": a practical guide to minor surgery for the Core Surgical Trainee

The first local anaesthetic operating list faced by a Core Surgical Trainee (CT) can appear a daunting task. Fresh from Foundation Year (FY) posts, (s)he will lack experience in basic surgical techniques. At present, there is no formal training in minor surgical skills for FY doctors, and exposure to operative surgery can be variable. This review provides an introduction and practical guide to the operative management of minor surgical pathologies.

Current management options for the small renal mass in a solitary kidney

The widespread use of cross-sectional imaging has resulted in an increase in the frequency of incidentally identified small renal masses (SRMs). With high cancer-specific survival rates following radical nephrectomy, there is an increasing patient cohort at risk of developing a metachronous contralateral tumour. Nephron-sparing surgery (NSS) has been shown to reduce progression of chronic kidney disease, being the impetus to utilize NSS for the management of SRMs in an anatomical or functional solitary kidney. At present, open partial nephrectomy is the gold standard treatment for an SRM in a solitary kidney; however, there are a number of other minimally invasive options, including laparoscopic partial nephrectomy, and in situ ablative procedures. In addition, variables such as warm and cold ischaemia and renal vascular clamping have been shown to affect outcomes. In this review, we summarize contemporary management options focusing specifically on oncological and functional outcomes.

Abstract P1-15-09: Ductal Carcinoma In Situ of the Breast: Clinico-Pathological Features Predicting Residual Disease in Postlumpectomy Re-Excision Specimens

INTRODUCTION:

Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer, which often grows discontinuously within the breast tissue. Younger age, residual mammographic microcalcifications, positive surgical margins, tumor size, nuclear grade and architectural type are consistently related to ipsilateral breast tumor recurrence in DCIS. To re-excise or not when a lumpectomy margin is close is a controversial issue for breast pathologists, surgeons and oncologists, and often no residual disease is found when a re-excision is performed. The aim of this study is to investigate the clinico-pathological features of DCIS that might predict residual disease in the re-excision specimen in patients treated by lumpectomy with either positive or close margins. METHODS:

Consecutive patients with DCIS who required postlumpectomy re-excision either for positive or for close margins were selected in this retrospective analysis. Close margin was defined as less than 0.1 cm. The initial lumpectomy specimens were examined for tumor size, architectural type, nuclear grade and margin status, and patient age was considered. The subsequent re-excision specimens were analyzed for residual disease. The clinico-pathological features of original lumpectomy specimens were correlated with the presence or absence of residual DCIS in the re-excision specimens. Logistic regression statistical test was used to determine if any of these clinico-pathological features predicted the presence or absence of DCIS in the subsequent re-excision specimens. RESULTS:

There were 37 cases of DCIS without accompanying invasive carcinoma that had positive or close resection margins (positive margin n=8; 21.6%, close margin n=29; 78.4%). Age of the patients ranged from 30 to 93 years. DCIS present in the original lumpectomy specimen was comedo type with necrosis n=8; 21.6% and non-comedo type n-29; 78.4%. Twenty-one lumpectomy specimens (57%) exhibited more than one type of DCIS. Four tumors were nuclear grade 1 (10.8%). 17 were nuclear grade 2 (45.9%), and 16 were nuclear grade 3 (43.2%). Residual DCIS was present in 20 out of 37 (54.1%) re-excision specimens. Six out of 8 (75%) comedo DCIS had residual disease, compared to 14 out of 29 (48.3%) non-comedo DCIS. Eleven out of 20 patients (55%) with residual disease were younger than 60 years. The correlation of patient age and type of DCIS to residual disease in the re-excision specimens was short of statistical significance due to small size of study sample (p value = 0.178 and 0.175 respectively). There was no statistically significant association between nuclear grade and distance to margin with residual disease in re-excision specimens (p value = 0.757 and 0.734 respectively). CONCLUSION:

Younger age and comedo type DCIS may be important factors in predicting residual disease in the re-excision specimens. If this can be confirmed in a larger, multi-institutional data set, there could be a more tailored selection of who needs a re-excision.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-15-09.

Abstract PD05-12: Combination of Notch Inhibitor MK-0752 and Endocrine Therapy for Early Stage ERα + Breast Cancer in a Presurgical Window Pilot Study

Background: Breast tumor initiating cells (TIC) use Notch receptors/ligands with other pathways for self renewal, resulting in tumor proliferation and progression. We showed that Notch inhibition with gamma secretase inhibitors (GSI) potentiates the effects of tamoxifen (tam) in xenografts (Rizzo et al. Cancer Res 2008). It is unknown whether GSIs plus endocrine therapy result in modulation of Notch and other proliferation markers in human breast cancer. Our objective was to add short exposure of the GSI MK-0752 to ongoing tam or letrozole (letr) during the presurgical window to determine 1) feasibility, 2) safety/tolerance, and 3) impact on biomarkers. We report the initial cohort of this pilot study (ClinTrials. gov NCT00756717).

Methods: Patients (pts) with early stage ERα + breast cancer were treated with 25 days of tam or letr. On day 15 MK-0752 was added to endocrine therapy (350 mg orally 3 days on, 4 days off, 3 days on), with definitive surgery day 25. Formalin fixed, paraffin embedded biopsies were obtained at baseline, day 14 and final surgery, with histologic confirmation of tumor content &gt;50% and RNA extraction by standard methods. Q-PCR was done for Notch1, Notch3, Notch4, Deltex, Jagged1, c-myc, HEY1, HEY2, HES1, PS2, C-Myc, Cyclin A2, NOXA (pro-apoptotic protein), Ki67, Dicer-1, RPL13 (internal control). Ct averages for 3 replicates were used and mRNA levels were calculated by the 2ΔΔCt method. Baseline gene expression levels were used as comparators for days 14 and 25 levels in each pt. The first cohort of 10 pts was analyzed to determine if enough signals were present to justify expanding the cohort at this dose to 20 pts and possibly test a second cohort on an alternate MK-0752 dose/schedule. Results: The initial cohort of 10 pts completed all therapy (4 tam, 6 letr), all biopsies and definitive surgery on schedule. One other pt withdrew prior to starting MK-0752 due to hypertension. Toxicity was minimal: grade 1 periorbital edema/cough, nausea, and axillary paresthesias in 1 pt each; grade 1 facial rash, 2 pts; and grade 2 fatigue, 1 pt. There was no diarrhea or surgical complications. Significant changes occurred in molecular marker levels after MK-0752 plus tam/letr (day 25) vs. end of tam/letr alone (day 14) as follows: Ki67 mRNA decreased in 9/10 pts; Notch4 decreased, 10/10; NOXA increased, 6/10; and Notch1 decreased, 6/10. Other markers showed inter-individual variations and will be presented, along with results of the global gene expression profiling (in progress). Conclusions: The addition of a short exposure of the GSI MK-0752 to ongoing endocrine therapy was feasible, safe, and well tolerated in pts with ERα + early breast cancer prior to definitive surgery. It results in anti-proliferative and pro-apoptotic effects at the molecular level. Notch4, which plays a key role in breast TIC, was the most consistent molecular marker of response in this setting. This suggests a potential anti-TIC effect of this combination and a role in overcoming endocrine resistance. Accrual to the expanded cohort is underway. If findings are confirmed, the second study with alternate MK-0752 dose/schedule may commence. Funding: Swim Across America, Inc. (clinical trial costs); Merck (drug supply, profiling)

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD05-12.

The RNA-binding and adaptor protein Sam68 modulates signal-dependent splicing and transcriptional activity of the androgen receptor

The RNA-binding protein Sam68 has been reported to be up-regulated in clinical cases of prostate cancer (PCa), where it is thought to contribute to cell proliferation and survival. Consistent with this, we observed over-expression of Sam68 in a panel of clinical prostate tumours as compared with benign controls. Since Sam68 is implicated in a number of signalling pathways, we reasoned that its role in PCa may involve modulation of the androgen receptor (AR) signalling cascade, which drives the onset and progression of PCa. We found that Sam68 interacts with the AR in vivo in LNCaP cells, and is dynamically recruited to androgen response elements within the promoter region of the prostate-specific antigen (PSA) gene. Based on its known functions and nuclear location, Sam68 might either: (a) co-regulate AR-dependent transcription positively or negatively; or (b) modulate AR-dependent alternative splicing by enhancing incorporation of a Sam68-responsive exon transcribed under the control of an androgen-responsive promoter. We tested these possibilities using functional assays. Both wild-type Sam68 protein and the Sam68(V229F) mutant, which is impaired in RNA binding, functioned as a ligand-dependent AR co-activator on an androgen-regulated reporter gene. In contrast, splicing of a Sam68-responsive variable exon, transcribed under control of an androgen-responsive promoter, was strongly repressed in the presence of AR and androgens. This splicing inhibition was reversed by ectopic expression of Sam68 but enhanced by Sam68(V229F). These results demonstrate that Sam68 has separable effects on AR-regulated transcriptional activity and alternative splicing, both of which may affect PCa phenotypes.