A Pilot Study To Compare Nutrition Screening Tools: Customized Nutrition Screening Tool for Burn Patients (Nstb) and Malnutrition Universal Screening Tool (Must)

Nutrition screening is an initial procedure in which the risk of malnutrition is identified. It plays a role in and can incur costs to health systems and patients. A customized nutrition screening tool for burn patients (NSTB) was formulated and the nutritional risk score of 22 patients from a burn unit in Bahrain using NSTB and MUST was compared. The samples selected were adult patients aged 18 years or over; pregnant and mentally retarded patients were excluded. Mean age of the total sample was 29.40, and 90.9% were male. Mean BMI was 26.96. The mean and SD for NSTB was 2.18±1.65, and for MUST 2.0±0.0. A difference in the nutritional screening risk score of the same group of patients was observed. In the MUST group, 100% patients were classified as high risk, while in the NSTB group 50% patients were classified as high risk, 36.36% as moderate risk and 13.63% as low risk respectively. The variability of the risk score in the NSTB group helps prioritize the patients based on high, medium, and low risk, whereas MUST categorizes all patients as high risk. A unique screening tool for burns will be more effective in determining risk patients due to tailor-made characteristics. Even though the data sample is small, the difference gives scope for extensive study.

Melanocyte-Keratinocyte Transplantation in Post-Burn Leukoderma Scars: Preliminary Experience Using a Modified Technique

Post-burn leukoderma, commonly affecting the African and Asian communities, results from deep dermal burns. The associated stigma exacerbates the condition and significantly affects the rehabilitation and reintegration of post-burn survivors into society. Melanocyte-keratinocyte transplantation (MKTP) is a promising single-stage treatment for repigmentation in vitiligo. However, its use in post-burn leukoderma is undetermined. This study aims to evaluate the MKTP treatment in post-burn leukoderma patches. Six patients (five males and one female, mean age = 29±5.51 years) with ten patches of post-burn leukoderma underwent single-stage MKTP without adjuvant pigmentation therapy. The postoperative follow-up period ranged from twelve to twenty-four months for all the patients. The average size of leukoderma treated was 16.25±9 cm2. Repigmentation was observed in 92.16±11.05% of the total treated area by the end of one year after MKTP application. All six patients were satisfied with the treatment outcome. MKTP without adjuvant therapy is an effective surgical treatment to treat post-burn leukoderma patches. Future studies should cover a larger sample over a longer follow-up period.

Conservative Management Of Partial-Thickness Scald Burns In Children Using Cultured Allogenic Keratinocyte Spray: Initial Experience Of 18 Patients Treated In An Outpatient Setting

The objective of this study was to describe our clinical experience with the use of cultured allogeneic keratinocyte (CAK) using a simplified cell delivery method in the treatment of pediatric partial-thickness scald burns treated as outpatients in a Burn Unit. An actuator fitted onto a 3ml syringe was used for cell spray. Eighteen patients having active mixed partial-thickness burn wound areas of <10% total body surface area (TBSA), treated between 2017 and 2019, were included in the study. The wounds were managed conservatively with a combination of burn dressings using hydrogels and CAK application. The timing of the CAK application was decided by the treating plastic surgeon based on his clinical judgment and the clinical status of the wound. The primary study endpoints were the number of days and dressing changes required for complete wound reepithelialization. All of the eighteen patients' wounds reepithelialized completely with CAK application, with a mean reepithelialization time of 10.33 (±4.95) days after the application of CAK. The median value for the number of CAK applications and total dressing sessions required to achieve complete healing were 3 and 4 times, respectively. Wounds treated with CAK application between 8-21 days after burn injury required fewer cell application sessions and fewer dressing changes than wounds treated within seven days and after 21 days from the burn injury. None of the patients reported any adverse reaction related to CAK use. The present study suggests that non-extensive mixed partial-thickness scald burn in children can be successfully treated conservatively using CAK as an adjunct in addition to standard dressing in the outpatient setting.

Abstract P2-03-11: Genetic background determines the algorithm of effectiveness of targeted drugs of RAS and PI3K pathways in TNBC: Testing a combination of MEK 1/2 inhibitor with mTOR kinase inhibitor or AKT inhibitor

Introduction: Most TNBC patients with single-agent targeted therapy in multiple clinical trials develop resistance, leading to disease progression, posing a major challenge in clinical management of mBRCA. In TNBC patients there remains a lack of obvious predictive biomarkers to guide targeted therapy. Although signaling mechanisms of resistance may be either intrinsic or acquired, the role of driver pathways are known be associated with oncogenic evolution of tumor cells to a resistant state. As the PI3K-AKT-mTOR1/2 (PAM) pathway is activated in TNBC (due to alterations in EGFR, 50%; PTEN, 40%; and PIK3CA, 5-10%), the PAM pathway is a candidate for potential molecular targeting of anti-cancer therapeutics. Despite the involvement of PI3K pathway activation in TNBC tumors, single agent PI3K inhibitors show modest clinical activity. Literature references suggest extensive cross-talk exists between the (PAM) and the RAS-RAF-MEK-ERK (MAPK) pathways. Here we tested the efficacy of a combination of MEK 1/2i (AZD6244, GDC0973) with mTOR kinasei (AZD2014, TAK228) or AKTi (AKT5363) in TNBC models. Methods: TNBC cell lines with alterations in KRAS/RAF (MDA-MB231), BRCA-deficient PTEN-loss (SUM149), PTEN-loss (MDA-MB468) and PIK3CA mutation (BT20) were used. Proliferation, apoptosis, cell cycle and 3D clonogenic growth were tested following drug treatment alone or in combination. Signaling events in the respective pathways following drug treatment were interrogated by WB. Results: MEKi led to a brief proliferation inhibition in MDA-MB231 cells. A combination of MEKi and mTORi was additive in decreasing short term proliferation and 10 day 3D growth. AKTi alone had limited effect on 3D growth but in combination with MEKi was profoundly inhibitory. A limited effect of MEKi was observed in BT20 cells; blocking 2D and 3D growth, while a profound effect of MEKi was observed in combination with mTORi (to a lesser extent with AKTi). In MDA-MB468 cells, MEKi did not have an initial appreciable effect (proliferation and G1 arrest), though 3D growth was significantly reduced at 10 days following drug alone or in combination with AKTi. SUM149 cells had G1 arrest with no appreciable change in 3D growth following MEKi. In contrast, single agent mTORi and AKTi reduced 3D growth. MEKi and mTORi doublet slowed proliferation, increased apoptosis and disrupted 3D growth. No single agent treatment with AKTi or mTORi disrupted colony formation however either agent in combination with MEKi blocked 3D growth. Single agents treatments were mostly cytostatic with no increase in apoptosis while a doublet of MEKi plus mTORi induced significant apoptosis.A combination of MEKi with PI3K pathway specific inhibitor significantly blocked phosphrylation of downstream effector molecules. Upregulation of ERK signals following PAM pathway inhibitors were abrogated by prior addition of MEKi. Summary: Combined blockade of the PAM and MAPK pathways (AKTi or mTORi) plus MEK1/2 inhibitor were more effective in attenuating molecular signals. This combination showed enhanced efficacy in TNBC cell models with specific PAM and or MAPK pathway alterations.

Citation Format: Carlson JH, De P, Dey N, Leyland-Jones B. Genetic background determines the algorithm of effectiveness of targeted drugs of RAS and PI3K pathways in TNBC: Testing a combination of MEK 1/2 inhibitor with mTOR kinase inhibitor or AKT inhibitor [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 P2-03-11.

Abstract P2-03-06: PTEN expression at the nexus of oncogenic signals in TNBC: Testing combination of p110beta-isoform-specific inhibitor with five PARP inhibitors

Background: TNBC is the most aggressive form of BRCA-associated BC subtype. The loss of PTEN is a common “first event” associated with basal-like subtype (Martins et al., 2012) and this mode of PI3K-pathway activation (deletion/mutation/loss of PTEN) occurs more frequently (35%) than PIK3CA (5-10%) mutations in TNBC (Ellis & Perou, 2013). Several reports suggest upregulation of PI3K/AKT mediated by PTEN loss depends on the PI3Kbeta-isoform. PARP1 is identified as a target of BRCA-defined cancers. Inhibitors of PARP1 have been recently approved by the FDA as targeted agents in BRCA-defined breast cancers. Failure to repair damaged DNA upon PARP inhibition causes accumulation of DNA double-strand breaks and leads to apoptosis of cancer cells. Also, nuclear PTEN controls DNA repair (Bassi et al., 2013). Here we hypothesized that a combination of PARP inhibitor with p110beta-isoform-specific inhibitor would sensitize the effect of PARP inhibitor(s) in PTEN-deprived TNBC model. Methods: We tested five PARP inhibitors, Talazoparib (BMN673, B), Niraparib (N), Olaparib (O), Rucaparib (R) and Veliparib (V) in combination with p110beta specific inhibitor, AZD6482. Four PTEN-null TNBC cell lines (BRCA WT/null), MDA-MB468, HCC70 (p.F90fs*9), BT549 (p.V275fs*1) and SUM149 cell lines were used for the study. Proliferative, apoptotic and PARylation signals following drug combinations were demonstrated by WB in a dose and time-dependent manner. Pro-apoptotic and anti-proliferative effects were verified using complementary 3D ON-TOP assay, real-time proliferation (Incucyte), AnnexinV and cl-caspase3 analyses. As an internal control, we also compared anti-proliferative signals of GDC-0032 (p110 beta sparing inhibitor) and GDC-0941 (pan PI3K inhibitor) with that of AZD6482 at 3/6 hours in MDA-MB468 and SUM149 cells. Mode of apoptosis was tested using triple fluorescence staining in live cells. Results: A dose of 500 nM BMN673 alone was effective in slowing cell proliferation and induced apoptosis. AZD6482 (5-10 uM) did not have anti-proliferative or pro-apoptotic effects at 48 and 72 hours. When compared, combinations of different PARPi (100nM of B, 1uM of N, 10uM of O, 10uM of R and 10uM of V) with AZD6482 abrogated 3D growth in BT549 and MDA-MB468 TNBC cells in a time-dependent manner. The effect of PARP inhibitor was tested by PAR signals which were abrogated either alone or in combination with carboplatin in both BRCA1/2 WT and mutated cells. The most pronounced anti-tumor effect was observed with the combination of B and AZD6482 which was mechanistically explained by the robust increase of AnnexinV positive cells following a single 500nM dose of B at both 48 and 72 hours. Pan PI3K inhibitor, GDC-0941, and AZD6482 blocked the activation of PI3K and its downstream effectors in contrast to p110 alpha-specific inhibitor, GDC-0032 in MDA-MB468 and SUM149 cells. Summary: We demonstrated a remarkable sensitivity of tumor cells to PARP inhibition in PTEN-defined TNBC models and identified PTEN-nullness as a potential predictive biomarker for a possible co-targeting of the PI3K pathway to further sensitize TNBC to PARP inhibitors.

Citation Format: Dey N, Carlson JH, De P, Leyland-Jones B. PTEN expression at the nexus of oncogenic signals in TNBC: Testing combination of p110beta-isoform-specific inhibitor with five PARP inhibitors [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 P2-03-06.

Abstract P2-03-08: Preclinical evaluation of the PI3Kα/δ inhibitor, copanlisib in HER2+ breast cancer: A proof of concept study

Purpose: The PI3K-AKT-mTORC1/C2 pathway is frequently activated in HER2+ breast cancer and upregulation of this pathway is a key mechanism of trastuzumab resistance. However, attempts to indirectly target this pathway by using the allosteric mTOR inhibitor everolimus have had limited clinical success. Here, we present the results of a preclinical study of the PI3K α/δ (dominant) inhibitor copanlisib alone and in combination with T-DM1, in HER2 amplified cell lines including a model with acquired resistance to trastuzumab.

Method: Anti-proliferative, apoptotic, cell cycle, and intracellular signaling effects of copanlisib alone and in combination with T-DM1 were evaluated in a panel of HER2 amplified (ER+ or ER-), and HER2 amplified/PIK3CA mutated cell lines, as well as trastuzumab-resistant breast cancer cell lines.

Results: 1) Copanlisib inhibited PI3K, mTOR and their downstream signaling molecules in HER2 amplified/PIK3CA WT or PIK3CA mutated as well as in trastuzumab-resistant cell lines, 2) interestingly, copanlisib also inhibited RAS-MAPK signaling in the earlier time points, 3) copanlisib caused a strong differential growth inhibition in HER2 amplified BC cell lines by 3D-ON-TOP clonogenic assay and real-time monitoring in an IncuCyte Zoom. Inhibition was greater when copanlisib was combined with T-DM1, 4) administration of copanlisib induced cell cycle G0/G1 arrest and resulted in increased apoptosis in a dose-dependent manner, 5) unlike everolimus copanlisib blocked HIF1α accumulation in hypoxic condition and this blocking effect was reversed by prior treatment with the proteasome inhibitor, carfilzomib and 6) copanlisib also attenuated HER2 amplified cell migration, an important phenotypic feature for metastasis.

Conclusions: Copanlisib is highly effective (blocks proliferation, induces apoptosis, and inhibits PI3K and its downstream signaling targets) in HER2 amplified breast cancer cell lines including trastuzumab-resistant and PIK3CA mutated cell lines. The addition of copanlisib to T-DM1 might represent an improved treatment strategy for patients with refractory metastatic HER2+ breast cancer.

Citation Format: De P, Carlson JH, Dey N, Leyland-Jones B. Preclinical evaluation of the PI3Kα/δ inhibitor, copanlisib in HER2+ breast cancer: A proof of concept study [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 P2-03-08.

Abstract P1-03-04: Role of PTEN and BRCA1 as determinants of synergy for the combination of vistusertib with carboplatin and olaparib in TNBC

Introduction: Platinum agents are being used in combination with targeted agents in advanced triple-negative breast cancer (TNBC) (See K. Gelmon et al., 2012). Additionally inhibition of PARP is also being considered as a “targeted” therapy for TNBC (Anders CK et al., 2010). PARP inhibitor (i), Lynparza (olaparib,AstraZeneca)met the primary endpoint of a Phase III trial in which Lynparza was compared to physician's choice of a standard of care chemotherapy in patients with HER2-negative metastatic BC harboring germline BRCA1/2 mutations (BRCAm). Based on cBioportal data analyses and experimental studies we and others have reported that more than 30% PTEN loss in TNBC leads to activation/upregulation of the PI3K pathway (Nature. 2012; Ellis and Perou, 2013; Dey et al., 2012; De et al., 2016; Reed and Shokat 2017;). In line with active kinase profiling, genetic and pharmacological data which defined mTOR as an important target in TNBC (Montero JC et al., 2012), we have demonstrated that mTORi has anti-tumor activity in TNBC (De et al., 2014). Aim: These studies focused on exploring the synergy of biology-based targeted drugs PARPi (olaparib, O), mTOR kinase (vistusertib, V), and platinum (C) in TNBC models. Method: TNBC cells of multiple genetic backgrounds were used to test the combination(s) on proliferation and apoptosis by monitoring growth and using real time Annexin V reagent in a microscopy-based assay (Essen IncuCyte Zoom). Flow cytometric analysis of cell cycle progression by PI staining was also used. Long term clonogenic 3D growth was monitored in matrigel. Results: In BRCAm/PTEN null Sum149 and HCC1937 cells and BRCA wild type (wt)/PTEN null MDA-MB-468 the addition of (V) to (O) and (C) enhanced apoptosis induction and further slowed growth. In Sum149 cells, single agent V treatment induced G1 arrest while O plus C or the triple combination increased S phase accumulation. In MDA-MB-468 cells G1 arrest was seen with V alone and in the triplet. In BRCA wt/PTEN null HCC70 cells V decreased cell proliferation and induced G1 arrest. In the HCC70 model, the addition of O plus C did not synergize with V. In BT20, a BRCA wt/PTEN wt but PI3KCA mutant cell line, no effect on proliferation or apoptosis was seen in the O plus C treated arms. V slowed cell proliferation and increased G1 arrest in a dose-dependent manner. As expected in a BRCA wt/PTEN wt, but RAS active mutant cell line MDA-MB-231 this treatment combination was not effective and was used as an internal negative control. Based on ratios of the normalized slopes of proliferation curves (for triplet), the cells were graded in terms of synergy as SUM149&gt;MDA-MB-468&gt;HCC1937 and HCC70&gt;BT20&gt;MDA-MB231. Treatment with the triplet had the largest effect on reducing 3D colony formation and size as compared to control over single or double treatment. Summary: Here, we present the effect of the combination of vistusertib with olaparib plus carboplatin in several TNBC models. Our data demonstrate that increased effectiveness of the triple combination is seen in cells harboring BRCA1 and PTEN-null mutations. The mechanistic role of these two targets on determining this synergy is being worked out and will be presented at the meeting.

Citation Format: Carlson JH, O'Connor MJ, De P, Dey N, Leyland-Jones B. Role of PTEN and BRCA1 as determinants of synergy for the combination of vistusertib with carboplatin and olaparib in TNBC [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-03-04.

Abstract PD4-15: A tale of two pathways: Mutations in PI3K pathway in TNBC patients matter for the oncogenic cooperation with DNA damage repair pathway

Background: Mutations guide targeted therapy in the personalized medicine. In the opening chapter of our recently edited book (Dey et al., 2016), Prof. L. Cantley elegantly elucidated the basic signaling of the PI3K pathway in cancers. Mutations in the PI3K pathway are not only common and subtype-specific in BC but are also contextual. Alterations in DNA damage repair (DDR) pathway involving HRD (Homologous Recombination Defect) genes are one of the important contextual events of the upregulation of the PI3K pathway (De et al., 2016). Aim: Here we interrogated the contextuality of alterations of the PI3K and DDR pathway genes in our Avera patients. The mechanism of contextual cooperation between the pathwayswas experimentally validated. Methods: We examined mutation profile (FoundationOne) of our patients (Avera Cancer Institute) and patients fromthe TCGA data (cBioPortal). We validated the cooperation of the two pathwaysexperimentally by the synergy model of mutation-specific drugs; PI3K-PTEN-mTOR pathway inhibitor(s) and PARP inhibitor(s) using TNBC model.Results: We analyzed alterations of 17 and 12 genes of the PI3K and DDR pathways respectively in subtypes of BC. In luminal A and HER2-enriched (TCGA, Nature 2012), the alteration of PIK3CA reached 49 % and 47% as compared to 37 % in luminal B and 25% in basal-like.In the basal-like/TNBC subtype (cBioPortal) 12 DDR pathway genes (CHEK1/2, RAD51, BRCA1/2, MLH1, MSH2, ATM, ATR, MDC1, PARP1, FANCF) were altered in 90.1 % of cases, and 17 PI3K pathway genes were altered in 88.9 % of cases.Our ER+ve patients presented a diverse variety of PIK3CA mutations (E545K,  E545A, E545G, E542K, E453K, E762K, E365K, N345K, C420R, E81K, Q546R, C420R, E726K, E81K, E970K, H1047R, H1047L P104L, P539R, G106R,G1049R, R93Q,N345T, V105_E109&gt;E, L113del, K111del) as compared to a less diverse type of PIK3CA mutations (Amplification, E542K, H1047R) in our TNBC patients. In our TNBC patients, the predominant type of mutation in PI3K pathway genes was found in PTEN consisting of Y68C, Y180*, loss, loss exons 1-5, and deletion exon1. The other most common mutation found in TNBC patients was in TP53 (&gt;80%) and somatic BRCA1/2 (˜15%) genes. The interaction between the two pathways was evaluated using the mostly altered oncogenes and tumor suppressor genes (PTEN, AKT1/2, TSC1/2, mTOR, RICTOR, RHEB, BRCA1/2, ATM, ATR, FANCF) applying STRING10 to test the association at the highest 0.900 confidence views. Finally, we experimentally validated the contextual synergy of 2 pathways by demonstrating that a node-specific inhibition of the PI3K-mTOR pathway by GDC-0980 in the presence of carboplatin resulted in (1) an enhanced impairment of DSB repair and (2) a subsequent sensitization to PARPi (i). This effect occurred simultaneously with the inhibition of classic PI3K-mTOR survival signal(s) which induced a robust antiproliferative/proapoptotic effect even in BRCA-competent TNBC cells. The absence of PTEN, on the other hand, sensitized TNBC cells to PARPi in the presence of carboplatin, an effect more pronounced in BRCA-loss. Conclusion: Our data showed that the PI3K pathway cooperates with the DDR pathway in the breast oncogenesis especially basal-like and TNBC.

Citation Format: Dey N, Williams C, Krie A, Klein J, Williams K, Carlson JH, De PK, Leyland-Jones B. A tale of two pathways: Mutations in PI3K pathway in TNBC patients matter for the oncogenic cooperation with DNA damage repair pathway [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD4-15.

Effects of fluid restriction on measures of circulatory efficacy in adults with septic shock

BACKGROUND

The haemodynamic consequences of fluid resuscitation in septic shock have not been fully elucidated. Therefore, we assessed circulatory effects in the first 24 h of restriction of resuscitation fluid as compared to standard care in intensive care unit (ICU) patients with septic shock.

METHODS

This was a post-hoc analysis of the multicentre CLASSIC randomised trial in which patients with septic shock, who had received the initial fluid resuscitation, were randomised to a protocol restricting resuscitation fluid or a standard care protocol in nine ICUs. The highest plasma lactate, highest dose of noradrenaline, and the urinary output were recorded in five time frames in the first 24 h after randomisation. We used multiple linear mixed effects models to compare the two groups.

RESULTS

We included all 151 randomised patients; the cumulated fluid resuscitation volume in the first 24 h after randomisation was median 500 ml (Interquartile range (IQR) 0-1500) and 1250 ml (500-2500) in the fluid restriction group and standard care group, respectively. The estimated differences in the fluid restriction group vs. the standard care group were 0.1 mM (95% confidence interval -0.7 to 0.9; P = 0.86) for lactate, 0.01 μg/kg/min (-0.02 to 0.05; P = 0.48) for dose of noradrenaline, and -0.1 ml/kg/h (-0.3 to 0.2; P = 0.70) for urinary output during the first 24 h after randomisation.

CONCLUSIONS

We observed no indications of worsening of measures of circulatory efficacy in the first 24 h of restriction of resuscitation fluid as compared with standard care in adults with septic shock who had received initial resuscitation.

Abstract P6-08-07: Gain and amplification of RAC1 GTP-ase in BC: Explaining alterations in patients by experiments using TNBC model

INTRODUCTION: RAC1-GTPase which transduces signals from cell surface integrins, have been implicated in metastasis. We reported that Wnt-beta-catenin pathway (WP) that signals metastasis (BMC Cancer, 2013), is one of the salient genetic features of Triple-Negative Breast Cancer (TNBC) (PlosOne, 2013).AIM: We demonstrated that TNBC cells acquire integrin-directed metastasis-associated (ID-MA) phenotypes following an upregulation of the WP (Oncotarget, In Press). Here we examined how WP signals are transduced in the context of ID-MA phenotypes in TNBC.METHOD: We documented gain and amplification of RAC1 gene in Breast Invasive Carcinoma subtypes from cBioPortal. The outcome for RFS was studied in the Hungarian ER-ve BC cohort.Mechanistically, we studied fibronectin-directed (1) migration, (2) matrigel- invasion, (3) RAC1 activation, (4) actin dynamics (confocal microscopy) and (5) podia-parameters using pharmacological agents (sulindac sulfide), genetic tools (beta-catenin siRNA), WP modulators (Wnt-C59, XAV939), RAC1 inhibitors (NSC23766, W56) and WP stimulations (LWnt3ACM, Wnt3A recombinant) in a panel of 6-7 TNBC cell lines, RESULTS: The collective percentage of gain and amplification of RAC1 were (1) 31% of total 1105 breast invasive carcinoma samples, (2) 29% of total 594 ER+ve samples, (3) 39% of total 174 ER-ve samples, (4) 38% of total 120 HER2+ve samples and (4)35% of total 82 TNBC samples (brca/tcga/pub2015; Cell 2015).In invasive ductal BC subtypes, gain and amplification of RAC1 were (1) 32% of total 201 Luminal A samples, (2) 37% of total 122 PAM50 Luminal B samples, (3) 47% of total 51 PAM50 Her2-enriched samples and (4) 33% of total 107 PAM50 Basal-like samples. In invasive lobular cancers, gain and amplification of RAC1 were 24% of total 127 samples.Involvement of WP in different TNBC cells was tested following stimulation by LWnt3ACM and Wnt3Arecombinant protein and different inhibitors of WP by both qRT-PCR and WB for beta-catenin, active beta-catenin, cMYC, cyclin D1and WP specific several stem cell markers. The WP attenuation, which (a) decreased cellular levels of beta-catenin, as well as its nuclear active-form, (b) decreased fibronectin-induced migration & invasion, (c) altered actin dynamics and (d) decreased podia-parameters was successful in blocking fibronectin-mediated RAC1/Cdc42 activity. Both Wnt-antagonists and RAC1 inhibitors blocked fibronectin-induced RAC1 activation and inhibited fibronectin-induced ID-MA phenotypes following WP stimulation by LWnt3ACM and Wnt3Arecombinant protein. High expression of RAC1 was associated with poor outcome for RFS with HR=1.48 [CI: 1.15-1.9] p=0.0019 in the Hungarian ER-veBC cohort.CONCLUSION:In TNBC model, the activation of RAC1 signals downstream of WP mediated ID-MA phenotypes. The identification of the functional relationship between RAC1 signaling and the WP activation in the control of ID-MA mechanistically explains how the activation of WP in TNBC is associated with the high metastatic incidences and a dismal outcome.

Citation Format: Dey N, Carlson JH, Jepperson T, Willis S, De P, Leyland-Jones B. Gain and amplification of RAC1 GTP-ase in BC: Explaining alterations in patients by experiments using TNBC model [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 P6-08-07.

Abstract P6-08-04: Preclinical efficacy of dasatinib in combination with PARP inhibitor plus standard cytotoxic agent in triple-negative breast cancer xenograft model

Background: Dasatinib is an orally-active ATP-competitive small molecule kinase inhibitor that potently inhibits Abl kinase, Src family kinases and other kinases (Lombardo et al., 2004). Src, one of the key targets of dasatinib is involved in the regulation of cell proliferation, survival and apoptotic ability of cancer cells (Tryfonopoulos et al., 2011; Pusztai et al., 2014). Dasatinib has shown its anti-proliferative and anti-metastatic effectiveness against triple-negative breast cancer (TNBC) in both preclinical and clinical studies (Finn et al., 2011). Several molecular targets including poly ADP ribose polymerase (PARP) are under clinical investigation for the treatment of TNBC. Recently, PARP inhibitors in combination with chemotherapy have shown promising results in this disease in clinical and preclinical studies (Tutt et al., 2010; Kim et al., 2013; De et al., 2014). Here, we hypothesize that dasatinib in combination with PARP inhibitor (ABT888) plus standard cytotoxic agent (carboplatin) will attenuate the growth of both TNBC cell lines and xenograft tumors. Methodology:We have used BT-20 (PIK3CA mutated, H1047R), HCC70 (PTEN null), HCC1937 (BRCA1 mutated, PTEN null), MDA-MB-231 (KRAS/BRAF mutated), MDA-MB-468 (PTEN null) and SUM149PT (BRCA1 mutated, PTEN null) cells for in vitro study. Survival/proliferation, colony formation and apoptosis were examined by using 2D proliferative/growth assay, 3D-ON-TOP assays, and annexinV staining respectively. We next studied the activation status of Src and its downstream signaling. We also have evaluated the effects on tumor growth inhibition of dasatinib/ABT888/carboplatin as a single agent or in combination by using mouse xenograft model. Results: We observed that 1) Dasatinib inhibited Src activation in all tested lines, induced dephosphorylation of ERK1/2 and S6 RP; 2) level of Cyclin D1 was decreased by dasatinib treatment; 3) high anti-proliferative activities were observed following the treatment of dasatinib along with ABT888 plus carboplatin in both 2D proliferation assay and 3D-ON TOP colony formation assay; 4) dasatinib in combination with ABT888 plus carboplatin inducing early stage apoptosis was seen by Annexin V staining in all tested cell lines; 5) dasatinib alone or combined with ABT888 or carboplatin or in triple combination inhibited tumor growth in TNBC xenograft models, the best tumor inhibition result was induced by triple combination (comparing to no treatment control, the mean tumor volume was decreased ~ 87% ). Conclusion: Our in vitro and in vivo studies suggest that dasatinib may enhance the antitumor activity of PARP inhibitor plus standard cytotoxic agent in TNBC. Mechanistic studies of xenograft tumor samples are ongoing, the results of which will be presented in the meeting.

Citation Format: Sun Y, Lin X, Carlson JH, De P, Dey N, Jepperson T, R & D NCI, Williams C, Leyland-Jones B. Preclinical efficacy of dasatinib in combination with PARP inhibitor plus standard cytotoxic agent in triple-negative breast cancer xenograft model [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 P6-08-04.

Abstract P6-08-09: Cancer stem cells define 3D clonogenic growth response to rational combinations of PI3K-isoform specific inhibitors in TNBC

This abstract was not presented at the symposium.

Abstract P2-03-02: Differential mutation pattern between neoadjuvant and metastatic settings in breast cancer patients

Background: Dysregulated signaling pathways occur in human cancers including breast cancer, making it a rational target for novel genome guided combinatorial personalized therapies. The aim of the present study was to investigate the different genetic mutation pattern between neoadjuvant and metastatic settings in breast cancer patients to guide research and clinical treatment.

Material and Methods: 150 breast cancer patients were involved in this study. 38 patients were receiving neoadjuvant treatment and 112 patients were in the metastatic setting. Tumor specimens obtained from the 150 patients were subjected to genetic mutation testing by FoundationOne. Genetic alterations detected by FoundationOne test were collected and analyzed.

Results: 96 and 149 different genes where reported by FoundationOne in neoadjuvant and metastatic setting respectively. The average number of non-synonymous mutation was five per case in the neoadjuvant setting and six per case in the metastatic setting. TP53 (58%), MYC (32%), PIK3CA (29%), PTEN (16%), CDH1 (13%), CCND1 (11%), EMSY (11%), LYN (11%) and ZNF703 (11%) were the most seen mutations in neoadjuvant setting. TP53 (40%), PIK3CA (39%), MYC (22%), CCND1 (21%), FGF19 (21%), FGF4 (21%), CDH1 (20%), FGF3 (19%), ERBB2 (17%), ESR1 (14%), FGFR1 (14%), ZNF703 (14%), GATA3 (13%), MYST3 (11%), PTEN (11%), EMSY (10%), NF1 (10%) and ZNF217 (10%) were the most seen mutations in metastatic setting. ESR1 and GATA3, which are seen in 14% and 13% of metastatic breast cancer patients, were not reported in neoadjuvant breast patients. Moreover, among the 16 metastatic breast cancer patients who has ESR1 mutation, 9 (56%) of them presented with PIK3CA or other genetic mutations which are directly involved in the phosphoinositide 3-kinase (PI3K)/AKT pathway.

Conclusion: A significantly more mutation in Receptor Tyrosine Kinases (RTKs)/ Growth Factor Signaling ( especially ERBB and FGFR pathways) was reported in the metastatic setting compare to the neoadjuvant setting, suggesting a critical role of the RTKs in metastatic breast cancer patients. The coexisting of ESR1 and PI3K/AKT pathway alteration and the absence of ESR1 in neoadjuvant setting also suggested that in early stage breast cancer patients who have a PI3K pathway alterations; there is a higher chance to develop ESR1 mutation with disease progression.

Citation Format: Xu B, Williams C, De P, Dey N, Klein J, Williams K, McMillan A, Leyland-Jones B. Differential mutation pattern between neoadjuvant and metastatic settings in breast cancer patients [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 P2-03-02.

Abstract P6-03-01: A combination of dual inhibition in HER2-network by T-DM1 and GDC-0980 provides maximal antitumor efficacy in preclinical model of HER2+ breast cancer

Background: PIK3CA mutation is associated with a lower pCR rate in primary HER2+ breast cancer (BC) treated with trastuzumab and lapatinib in addition to chemotherapy (from five clinical trials, PMID: 27177864). The BOLERO-1 study showed that the efficacy of a combination of mTOR inhibitor (everolimus) plus trastuzumab (T) and paclitaxel was not very efficacious with HER2+ advanced BC patients except for HER2+/ER- BC patients (PMID: 26092818). In the same line, BOLERO 3 trial data showed the same combination (T + everolimus + vinorelbine) is also not efficacious in T-resistant, HER2+ advanced breast cancer women (median PFS 7 months with everolimus and 5.78 months with placebo, HR: 0.78) (PMID: 24742739). T-DM1 does not have typical adverse events of chemotherapy. Therefore, there has been interest in combining it with other targeted agent. Here we tested the efficacy of a combination of T-DM1 plus GDC-0980 (a dual PI3K/mTOR inhibitor) in HER2+/T-resistant BC cell lines in vitro and in vivo. Methodology: Here we have studied the in vitro and in vivo effects of GDC-0980 along with T-DM1 in HER2+/T-sensitive (BT474), HER2+/T-resistant (BT474HerR), and HER2+/PIK3CA (HCC1954, MDA-MB453) mutated models. We assessed in vitro anti-proliferative, pro-apoptotic and activation status of the PI3K-AKT-mTOR signaling pathway following the combination of GDC-0980 plus T-DM1 in HER2+ BC cell lines. We next evaluated the impact of GDC-0980 plus T-DM1 on tumor growth and angiogenesis using xenograft models. Results: 1) GDC-0980 inhibited downstream activation of the PI3K-mTOR signaling pathway effectors, p-AKT (Ser473, The308), p-P70S6K, p-S6RP and p-4EBP1, and this inhibition was more pronounced when GDC-0980 was combined with T-DM1, 2) similarly the anti-proliferative activity of a combination of GDC-0980 plus T-DM1 was significantly higher by 3D-ON-TOP clonogenic assay following heregulin stimulation, 3) consistent with anti-proliferative effects of GDC-0980, the proportion of cells in the G1 phase of the cell cycle increased in HER2+ cell lines with a concomitant decrease in the S phase of their treatment with GDC-0980, 4) the initiation of apoptotic activity (annexin V) of GDC-0980 was significantly superior to that of an allosteric inhibitor of mTOR, RAD001. GDC-0980 also induced apoptotic markers like cleaved CASPASE3, cleaved PARP1, BIM in HER2+ BC cells and 5) a combination of GDC-0980 plus T-DM1 significantly blocked tumor growth to tumor regression in the HER2+/T-sensitive, HER2+/T-resistant and HER2+/PIK3CA mutated BC xenograft models. Along with its anti-tumor effect, this combination effectively decreased tumor angiogenesis (tumor micro-vessel density via CD31 staining). Conclusions: A combination of GDC-0980 plus T-DM1 significantly blocked in vitro and in vivo HER2+ breast tumor cells growth irrespective of PIK3CA mutation status. This strategy warrants further clinical investigation.

Citation Format: De PK, Carlson JH, Sun Y, Lin X, Friedman L, Dey N, Leyland-Jones B. A combination of dual inhibition in HER2-network by T-DM1 and GDC-0980 provides maximal antitumor efficacy in preclinical model of HER2+ breast cancer [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 P6-03-01.

Abstract P3-14-08: Preclinical efficacy of targeting c-MET by ARQ197 in combination with PARP inhibitor plus standard cytotoxic agent in triple-negative breast cancer cell lines

Background: Triple-negative breast cancer (TNBC), accounts for 15% of all invasive breast cancers (BCs) and has the poorest survival outcome of all BC subtypes. Due to its heterogeneity, TNBC lacks validated therapeutic targets compared with other BC subtypes (Sohn et al., 2014; Foulkes et al., 2010). Therefore, improved approaches to treatment of these cancers are unmet needed. Several molecular targets including: epidermal growth factor receptor (EGFR), poly ADP ribose polymerase (PARP), and hepatocyte growth factor receptor (c-MET) are under clinical investigation for the treatment of this disease (De et al., 2014; Cleator et al., 2007). The MET oncogene encodes a membrane-bound tyrosine kinase implicated in the formation and/or progression of several cancer types including TNBC, and several studies have shown c-Met overexpression to be an independent predictor of poor outcome in BC (Ho-Yen et al., 2014), c-MET may play a critical role in the development of the most aggressive BCs and may be a rational therapeutic target (Graveel et al., 2009). Currently inhibitors targeting c-MET (including ARQ197) are undergoing clinical trials in a variety of cancers including TNBC (Gaule et al., 2014; ClinicalTrials.gov). Recently, PARP inhibitors in combination with chemotherapy, has shown promising results in TNBC in clinical and preclinical studies (Tutt et al., 2010; De et al., 2014). We argue that, blocking the PARP-mediated nuclear machinery for repairing DNA-damage in presence of cytotoxic DNA damaging agents in conjunction with co-targeting c-Met pathway dependent downstream effectors may have a robust anti-tumor activity in TNBC cell lines. Methodology: BT-20 (PIK3CA mutated, H1047R), HCC70 (PTEN null), HCC1937 (PTEN null), MDA-MB-231 (KRAS/BRAF mutated), MDA-MB-468 (PTEN null) and SUM149PT (BRCA1 mutated) cells were used for this study. Growth inhibition, survival/proliferation, colony formation and apoptosis were examined using MTT assay, 2D proliferative /growth assay, 3D-ON-TOP assays, and annexinV staining respectively. Results: 1) For all TNBC cell lines, the IC50 of single agent ARQ197 was from 0.5 µM to 1.5 µM (following 96 hours treatment) 2) ARQ197 as a single agent or in combination with ABT888 or in triple combination dose dependently decreased cell growth/proliferation 3) annexin V positive cells were increased following treatment with single agent ARQ197 or in combination with ABT888 or in triple combination 4) 70-99% anti-proliferative activities were observed on 3D-ON TOP colony formation assay with ARQ197 alone or in combination in all tested cell lines. Conclusion: Our preclinical in vitro drug sensitivity data suggest that administration of c-MET inhibitor may enhance the antitumor activity of PARP inhibitor plus standard cytotoxic agent in TNBC models. Mechanism studies are ongoing, the results of which will be presented in the meeting.

Citation Format: Sun Y, Carlson JH, Lin X, De PK, Williams C, Hausman S, Dey N, Leyland-Jones BR. Preclinical efficacy of targeting c-MET by ARQ197 in combination with PARP inhibitor plus standard cytotoxic agent in triple-negative breast cancer cell lines. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-14-08.

Abstract P4-08-04: Navigating genomic landscape to find a PI3K-signaling algorithm for a rational combinatin in precision medicine

Background: Treatment of BC is conventionally based on the presence/absence of ER/PR or HER2 status of the primary tumor. We have enriched this approach by including major genetic and proteomic changes in tumors of individual patients in order to develop a better treatment-rationale based on an alteration driven signaling algorithm. Methods: Genomic and proteomic data from 75 BC patients seen in our center were retrospectively analyzed. Patients were re-biopsied after consultation and samples were characterized (IHC for ER, PR, and HER2; FFPE samples for genomic [Foundation Medicine] and proteomic analyses [Theranostics]). In vivo studies were conducted using xenograft models. Results: Although alterations of PIK3CA, PIK3R1, AKT, PTEN, MDM2, MDM4, TSC1, mTOR and RICTOR are most frequently observed in our patients, there is a distinct pattern of alteration(s) of the PI3K pathway genes in different subtypes of BC. A total of 76 genes were altered in 48 ER+BC patients. In 79% of ER+BC patients the above mentioned PI3K pathway genes were altered. Analyzing the set of alterations of genes in individual patients, we observed that within these 48 patients 25% exhibited alterations in more than one node of the pathway; the most common combination (alterations) being the amplification/mutation of PIK3CA with the amplification of MDM2/4 genes. The percentage of patients belonging to HER2+ & TNBC exhibiting similar alterations in the PI3K pathway genes were significantly lower (∼40%). Our previous in vivo studies demonstrated that GDC-0980 and BEZ235 enhanced the antitumor activity of ABT888 plus carboplatin in TNBC or trastuzumab in HER2+ BC respectively and blocked the growth of established xenograft tumors by 80% to 90% with a concomitant decrease in tumor Ki67, pS6RP and CD31. Mechanistically the action of the PI3K-mTOR pathway targeted drug(s) was tested using cell line based models of BC subtypes pertaining to their respective genomic alterations. A combination of a pan-PI3K pathway inhibitor, GDC-0941 or isoform-specific inhibitors along with AI, trastuzumab, or HRD inhibitors (PARP) blocked proliferative signals and enhanced apoptosis (cleaved caspase3) in ER+/PIK3CA mutated, HER2+/PIK3CA mutated or PTEN-null TNBC cells respectively as demonstrated by WB, flow cytometry, cell proliferation, viability and cytotoxicity assays. A recent study demonstrated that exposure to chemotherapy induced a phenotypic shift or cell state transition towards a transient CD44Hi/CD24Hi chemotherapy-tolerant state, leading to the activation of downstream non-receptor tyrosine kinase signaling towards an emerging adaptive resistance (Goldman et al., Nature Comm. 2015). Hence drug combination(s) are being tested for their effect on CD44/CD24 expression levels, results of which will be presented in the meeting. Conclusion: Plotting the genetic alterations from the patient on the signaling landscape will be useful in cracking the code leading to improved treatment options. Patient specific in-depth plotting of genetic alterations of the PI3K-mTOR pathway and the relevance of these alterations in the context of (1) mechanisms of PI3K-mTOR pathway targeted drugs and (2) cell signaling are critical in determining choice of drugs in BC subtypes.

Citation Format: Carlson JH, Krie A, Williams C, Sun Y, Lin X, Williams K, Klein J, Friedman L, De P, Dey N, Leyland-Jones B. Navigating genomic landscape to find a PI3K-signaling algorithm for a rational combinatin in precision medicine. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-08-04.

Abstract P5-16-01: Implementation of routine genomic and proteomic profiling of metastatic breast cancer patients in a community cancer center

Background: The optimal treatment strategy for patients with metastatic breast cancer (MBC) is currently unknown. Resistance to standard therapies, including anthracyclines and taxanes, limit the number of treatment options in many patients to a small number of non-cross resistant regimens. Rational combination approaches that are selected based upon genomic and proteomic analysis represents a possible advance that warrants extensive exploration.

Methods: Single center analysis of 77 consecutive metastatic breast cancer patients seen over a 12 month period (June 2014 through May 2015). All patients were referred for sequencing and the metastatic disease was rebiopsied. All samples were sent for standard pathologic, genomic (FoundationOne), and proteomic (TheraLink) analysis.

Results: Genomic and proteomic analysis yielded actionable targets in a majority of cases (89%). The most common pathways involved were the following: PI3K/Akt/mTOR (73%), MAPK (46%), ErbB (36%), FGFR (25%), and Jak/STAT (11%). Over 100 unique molecular aberrations were identified in 40 evaluable patients. Current outcomes are summarized in Table 1. The overall response rate was 45%, with another 43% of patients with stable disease. Average number of prior therapies was over 4, with a range of 1-11.

Table 1ER+/HER2-CR = 3PR = 8SD = 15PD = 2NE = 20ER+/HER2+CR = 2PR = 2SD = 1PD = 0NE = 9ER-/HER2+CR = 0PR = 1SD = 1PD = 1NE = 2Triple NegativeCR = 0PR = 2SD = 0PD = 2NE = 6Total evaluable patients = 40Overall CR = 13%Overall PR = 33%Overall SD = 43%Overall PD = 13%Total Not Evaluable = 37 pts (48%)Overall Response Rate (ORR) = 45%     CR = complete response PR = partial response SD = stable disease PD = progressive disease NE = not evaluable

Conclusion: Since current literature suggests that an overall response rate of approximately 10% or less is expected for patients that have received greater than 4 previous lines of therapy, the ORR seen in this analysis is quite remarkable. Most patients in this analysis were treated with FDA approved drugs off label, which provided additional challenges and was the primary reason that many patients were not evaluable. Patients were only evaluable if they received the recommended therapy and were measured for outcome. Our initial data provides growing evidence that it is critical to incorporate genomic and proteomic analysis (preferably as early as possible in the disease course) to allow for the best chance of disease response.

Citation Format: Williams CB, Krie A, De P, Dey N, Klein J, Williams KA, Hoogeveen M, Solomon B, Leyland-Jones B. Implementation of routine genomic and proteomic profiling of metastatic breast cancer patients in a community cancer center. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-16-01.

Abstract P5-03-14: MLN0128 regulates survival signaling by AKT and its downstream effectors in HER2+ breast cancer model

Evading apoptosis is considered to be a hallmark of cancers including breast cancer, since mutations in apoptotic regulators invariably accompany tumorigenesis. Chemotherapeutic agents induce apoptosis, and hence disruption of apoptosis during tumor progression may promote drug resistance. AKT is an apoptotic regulator that is activated in HER2+ breast tumor cells and promotes anti-HER2 therapy resistance in vitro. Nevertheless, how mTORC1/C2-AKT signaling disables apoptosis and its contribution to clinical drug resistance are not clear yet. Using HER2 amplified breast cancer cells [BT474 (HER2+/Trastuzumab-sensitive), BT474HerR (HER2+/Trastuzumab-resistant), HCC1954 and MDA-MB453 (both are HER2+/PIK3CA kinase domain mutated)], we show that mTORC1/C2 inhibitor; MLN0128 abrogates AKT (Ser473), Survivin and controls its downstream effectors of apoptotic signaling molecules (e.g. cleaved Caspase 3/9, cleaved PARP, MCL and BIM). MLN0128 also induces annexinV positive cells and regulates cellular proliferation (ON-TOP 3D colony formation and real-time proliferation assay). Additionally, increased cleaved Caspase 3 and decreased MCL1 expression were also observed following MLN0128 treatment in HER2+ xenograft model along with tumor growth inhibition. Our studies provide strong experimental evidence that high apoptotic signaling –specifically reduced MCL1 and increased cleaved-CASPASE3 expression expedite the response of targeted therapy that directly inhibits mTORC1/C2-AKT signaling.

Citation Format: De PK, Carlson JH, Sun Y, Lin X, Williams C, Dey N, Leyland-Jones BR. MLN0128 regulates survival signaling by AKT and its downstream effectors in HER2+ breast cancer model. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-03-14.

Abstract P2-05-09: Vascular mimicry in metastatic breast cancer patients: Molecular insight to vascular mimicry using in vitro and in vivo models

Background: Vascular Mimicry (VM) is an endothelium-independent matrix-embedded, blood-perfusion phenomenon exhibited by highly plastic and aggressive tumor cells in patients with solid tumors including breast. VM is characterized by PAS+ de novo formations of micro-vascular networks which are essentially CD31- and CD34-. VM is a micro-circulatory phenomenon which perfuses rapidly growing tumors, transporting fluid from leaky vessels and/or connects with the constituent endothelial-lined vasculature. One of the hallmarks of metastasis in BC is the heterogeneity observed between primary tumors and metastases (&amp; among metastases) (Marino etal., 2013). Recently a model of BC heterogeneity revealed VM as a driver of metastasis which in turn has been associated with disease heterogeneity (Wagenblast etal., 2015). Aim: Since BC is an aggressive and heterogeneous disease and VM is associated with the aggressiveness / poor outcome in BC, we sought to understand the functional relationship of VM with metastasis. Method: Tumors from our BC patients and TMAs were stained for CD31/PAS and CD34/PAS to identify VM. Genomic and proteomic data from these patients were obtained from re-biopsied (after consultation) samples (IHC for ER, PR, and HER2; FFPE samples for genomic [Foundation Medicine] and proteomic [Theralink] analyses). Result: VM was identified in metastatic tumors from ER+ and TNBC patients as CD31-/PAS+ and CD34-/PAS+ structures in contrast to the CD31+/PAS+ and CD34+/PAS+ angiogenic compartment of the individual tumor(s). Metastatic tumors exhibiting VM were characterized by pathological features like metaplastic lesions, positive lympho-vascular invasion and were found to be poorly differentiated. Predominant genetic alterations in these patients included (1) PI3K-mTOR pathway genes, (2) p53 (R273P, D281V), (3) BRCA1 E1683* (for TNBC), (4) MYC amplification, (5) aurora kinase, (6) CCND1 &amp; CDK4 amplifications and (7) loss of CDH1 exons1-3. Amplifications of cell surface TKIs/ligands included EGFR, FGFR and several FGFs. Proteomic data indicated an overexpression/activation of HER family (HER1/HER2/HER3), mTOR activation (p∼S2448), MEK1/2 activation (p∼S217-221) and JAK2 activation. In order study VM, we standardized VM formation both in 2D and 3D configurations in multiple BC cell lines which exhibited VM at differing times. The earliest response was observed around 2-3 hours in BT20, Hs578t and MDA-MB231. By 24 hours BT474, BT474HerR, SUM149, DKAT, MDA-MB231BR, Hs578t and MDA-MB468 cells demonstrated 2D VM. The BT20 cell line showed the most pronounced 3D-VM at 24 hours while MDA-MB468 was least sensitive to VM. Typical cord formation in HUVEC cells stained with hematoxylin and PAS were used for comparison. Using 2D and 3D models of VM we demonstrated the involvement of PI3K and Wnt-beta-catenin pathways in VM. Considering the involvement of VM in mediating the aggressive/metastatic nature of TNBC, we also tested VM in in vivo xenograft models using brain metastasic specific MDA-MB231BR cells, results of which will be presented in the meeting. Significance: To our knowledge this is the first report to identify genetic alterations and proteomic changes associated with VM in metastatic BC.

Citation Format: Dey N, Carlson JH, Lin X, Sun Y, Theel S, Krie A, Sulaiman RA, Williams C, De PK, Leyland-Jones BR. Vascular mimicry in metastatic breast cancer patients: Molecular insight to vascular mimicry using in vitro and in vivo models. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-05-09.

A mathematical model approach quantifying patients' response to changes in mechanical ventilation: evaluation in volume support

This paper presents a mathematical model-approach to describe and quantify patient-response to changes in ventilator support. The approach accounts for changes in metabolism (V̇O2, V̇CO2) and serial dead space (VD), and integrates six physiological models of: pulmonary gas-exchange; acid-base chemistry of blood, and cerebrospinal fluid; chemoreflex respiratory-drive; ventilation; and degree of patients' respiratory muscle-response. The approach was evaluated with data from 12 patients on volume support ventilation mode. The models were tuned to baseline measurements of respiratory gases, ventilation, arterial acid-base status, and metabolism. Clinical measurements and model simulated values were compared at five ventilator support levels. The models were shown to adequately describe data in all patients (χ(2), p > 0.2) accounting for changes in V̇CO2, VD and inadequate respiratory muscle-response. F-ratio tests showed that this approach provides a significantly better (p < 0.001) description of measured data than: (a) a similar model omitting the degree of respiratory muscle-response; and (b) a model of constant alveolar ventilation. The approach may help predict patients' response to changes in ventilator support at the bedside.

Automated and accurate carotid bulb detection, its verification and validation in low quality frozen frames and motion video

AIM

Carotid intima-media thickness (cIMT) measurements during clinical trials need to have a fixed reference point (also called as bulb edge points) in the anatomy from which the cIMT can be measured. Identification of the bulb edge points in carotid ultrasound images faces the challenge to be detected automatically due to low image quality and variations in ultrasound images, motion artefacts, image acquisition protocols, position of the patient, and orientation of the linear probe with respect to bulb and ultrasound gain controls during acquisition.

METHODS

This paper presents a patented comprehensive methodology for carotid bulb localization and bulb edge detection as a reference point. The method consists of estimating the lumen-intima borders accurately using classification paradigm. Transition points are located automatically based on curvature characteristics. Further we verify and validate the locations of bulb edge points using combination of several local image processing methods such as (i) lumen-intima shapes, (ii) bulb slopes, (iii) bulb curvature, (iv) mean lumen thickness and its variations, and (v) geometric shape fitting.

RESULTS

Our database consists of 155 ultrasound bulb images taken from various ultrasound machines with varying resolutions and imaging conditions. Further we run our automated system blindly to spot out the bulbs in a mixture database of 336 images consisting of bulbs and no-bulbs. We are able to detect the bulbs in the bulb database with 100% accuracy having 92% as close as to a neurologists's bulb location. Our mean lumen-intima error is 0.0133 mm with precision against the manual tracings to be 98.92%. Our bulb detection system is fast and takes on an average 9 seconds per image for detection for the bulb edge points and 4 seconds for verification/validation of the bulb edge points.

Link between automated coronary calcium volumes from intravascular ultrasound to automated carotid IMT from B-mode ultrasound in coronary artery disease population

AIM

Establishing relationship between coronary calcium volumes from Intravascular Ultrasound (IVUS) and automated carotid intima-media thickness (cIMT) helps in understanding the genetic nature of atherosclerosis disease. In this research, we have quantified the detected calcium from IVUS video frames and associated a relationship between coronary calcium volumes computed and automated cIMT from B-mode ultrasound.

METHODS

Coronary calcium volume is computed from IVUS and auto cIMTs are computed using B-mode ultrasound. An automated computer based application is developed and tested on 100 patient volumes (an average of 2549 frames per volume) to calculate lesion area and normalized coronary calcium volume. We use an integrated approach for volume computation which is based on lesion area per frame. We have measured the normalized volume from the calcium detected video frames using proposed integration method. The cIMT of 100 carotids were measured with novel and dedicated automated software analysis (AtheroEdge™ from AtheroPoint™ LLC, Roseville, CA, USA).

RESULTS

The computer-based coronary calcium volume (from IVUS) showed a correlation coefficient with respect to cIMT for left and right carotids as 9.1% and 13.9%, respectively.

CONCLUSION

Coronary calcium volume computed from IVUS and auto cIMT are moderately correlated. The association between auto cIMT (right side) vs. computer-based coronary calcium volume (IVUS) is stronger than the association between auto cIMT (left side) vs. computer-based coronary calcium volume.

Abstract P3-04-02: Absence of PTEN facilitates the anti-tumor efficacy of GDC-0980 in combination with ABT888 plus carboplatin in BRCA1-competent triple negative breast cancer

Introduction: PI3K pathway, in addition to its pro-proliferative and anti-apoptotic effects on tumor cells, is known to contribute to DNA-damage repair (DDR). We hypothesized that GDC-0980, a dual PI3K-mTOR inhibitor, will induce an efficient anti-tumor effect in BRCA-competent PTEN-null TNBC cells when combined with PARP inhibitor, ABT888 and carboplatin. We propose that in PTEN-null BRCA-competent TNBC model, the growth of TNBC tumor will be blocked due to the inhibition of (1) HR and NHEJ and (2) PI3K-mTOR pathway mediated survival signals following treatment with GDC-0980, when combined with PARP inhibitor (impaired DNA-SSB-repair) and carboplatin (increased DNA-DSB). Purpose: Here we tested the efficacy of a combination of GDC-0980 with ABT888 plus carboplatin in BRCA-competent PTEN-null model of TNBC. Methods: Athymic mice bearing PTEN-null TNBC xenograft tumors were treated with GDC-0980 alone or in combination with ABT888 and carboplatin. Results: Dual inhibition of PI3K and mTOR by GDC-0980 alone as well as in the presence of carboplatin plus ABT888 changed the state of the repair of DNA-damage in BRCA-competent PTEN null TNBC cells, which led to increased cellular apoptotic signals in addition to decreased survival/proliferative signals. GDC-0980 treatment led to DNA damage (increased pgH2AX), gain in PAR and a subsequent sensitization of BRCA-competent PTEN-null MDA-MB468 TNBC cells to ABT888 plus carboplatin with a time-dependent (1) decrease in proliferation signals (pAKT T308/S473, pP70S6K, pS6RP), PAR/PARP ratios, PAR/pgH2AX ratios, live/dead cell ratios, cell-cycle progression and clonogenic 3D growth and (2) increase in apoptosis markers (cleaved-caspase 3, 9, BIM, cleaved-PARP and annexinV positivity). These effects are more pronounced in MDA-MB468 than in RAS/RAF mutated MDA-MB231 cells. GDC-0980 alone and in combination with ABT888 plus carboplatin inhibited cell cycle progression, increased apoptosis, and decreased live/dead cell ratios in BRCA-competent PTEN null TNBC cells. GDC-0980 alone and in combination with ABT888 plus carboplatin attenuated anchorage -dependent and -independent clonogenic 3D growth comparatively more in BRCA-competent PTEN-null cells TNBC cells than MDA-MB231 cells. GDC-0980 in combination with ABT888 plus carboplatin blocked the growth of established PTEN-null TNBC tumors as compared to vehicle control(s) with a concomitant decrease in tumor Ki67 and CD31 IHC-stains. Conclusion: This is the first mechanism-based study to demonstrate that in BRCA-competent PTEN-null TNBC model, GDC-0980 enhanced antitumor activity of ABT888, in the presence of carboplatin by inhibiting DDR system in conjunction with the inhibition of PI3K-mTOR pathway-mediated proliferative, and anti-apoptotic signals. Considering (1) the importance of PARP as the target in TNBC, (2) the existence of a large percentage of BRCA-competent TN and/or basal type BC patients and (3) the high frequency of PTEN-null-ness in this subset of BC, this combination merits further investigation.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-04-02.

Abstract P5-06-01: The PI3K inhibitor GDC-0941 combines with trastuzumab for superior anti-tumor efficacy in HER2+ breast cancer models

Background: PI3K-AKT-mTOR pathway signaling is important for the oncogenic function of HER2. Activating alterations of this pathway are frequently observed in HER2-enriched breast cancer and generally herald a poor response and resistance to trastuzumab (T). Purpose: Targeting the PI3K-AKT-mTOR pathway is an attractive strategy in HER2+ breast cancer that is refractory to trastuzumab. The hypothesis is that the suppression of this pathway by pan-PI3K inhibitor, GDC-0941 may lead to overcome trastuzumab-resistance. Experimental Design: The antiproliferative and HER2-mediated cellular signaling (pAKT, pP70S6K, pS6RP, p4EBP1 and p-ERK) effects of GDC-0941 alone and in combination with T were evaluated in HER2 amplified T-sensitive (BT474), T-resistant (BT474HR), and HER2 amplified/PIK3CA mutated (HCC1954, UACC893) BT cell lines by MTT assay and Western blots. Clonogenic growth was tested by 3D ON-TOP assay and apoptosis markers were also tested. Athymic mice bearing BT474 and BT474HR xenograft tumors were treated with GDC-0941 and T (alone and in combination). Results: (1) GDC-0941 exhibited in vitro cell killing activity in MTT assay with IC50's ranging from 0.35 μM to 1 μm and potency was augmented by the addition of T, (2) inhibition of phosphorylation of AKT(S473, T308), P70S6K, S6RP, and 4EBP1(T37/46, T70) was observed following GDC-0941 treatment, and the combination of GDC-0941 and T more effectively blocked the PI3K-AKT-mTOR pathway, (3) GDC-0941 treatment increased apoptosis markers (CL-CASPASE3 and annexinV positivity), (4) GDC-0941 dose-dependently blocked 3D-ON-TOP clonogenic growth of HER2+ cells. This effect was potentiated in the presence of T and (5) in vivo, the combination of GDC-0941 and T significantly reduced established tumor growth in both sensitive (82%) and resistant (79%) models with concomitant decrease of different PD markers. Conclusions: Our data suggest that 1) therapeutic targeting of the PI3K-AKT-mTOR signaling should be effective in abrogating resistance to T therapy in HER2+ BT, and 2) targeting both the HER2 and the PI3K signaling pathways is an attractive strategy to enhance the clinical efficacy of T therapy, as well as to prevent or delay the development of resistance.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-06-01.

Antioxidative responses of Salvinia (Salvinia natans Linn.) to aluminium stress and it's modulation by polyamine

Antioxidative stress response of free-floating aquatic fern (Salvinia natans Linn.) was studied under increasing toxic amount of aluminium (Al) and its modulation by exogenous application of polymaine. Increased levels of superoxide (O2 (-)) and hydrogen peroxide (H2O2) species from affected tissues suggested that plants were undergoing oxidative stress and it was concominant with increased accumulation of Al in a dose dependent manner. Application of polyamine like putrescine (Put) led to a decrease in oxidative stress as revealed by reduced level of O2 (-) and H2O2. Al toxicity resulted into decreased biomass that was ameliorated by the application of Put. The changes observed in lipid peroxidation (MDA) and protein oxidation also indicated that plats are undergoing Al induced oxidative stress. In order to circumvent the oxidative stress resulting from Al toxicity, plants enzymatic and nonenzymatic antioxidant pathways were active. The ratio of both oxidized and reduced cellular glutathione exhibited significant variation in response to Al stress and was improved upon Put treatment. Peroxidase and glutathione were upregulated whereas catalse was downregulated under varying doses of Al. Isozyme profile of above enzymes also showed a trend with increasing amount of Al. The nuclear disintegration study using comet assay was indicative of Al induced oxidative stress. In the present study, we have explored the antioxidative response of aquatic fern Salvinia natans Linn in response to Al toxicity. The application of polyamine Put improved the overall antioxidative response and thus would make it a better candidate to be used as hyper accumulator of Al and other toxic metals.

Abstract P5-19-03: Olaparib plus carboplatin in combination with vandetanib inhibited the growth of BRCA-wt triple negative breast tumors in mice: Outside BRCA-box

Introduction: PARP inhibition has emerged as one of the most exciting and promising ‘targeted’ therapeutic strategies in the treatment of advanced triple negative breast cancer (TNBC) – the intended ‘target,’ being DNA repair (Anders CK, 2010). Although olaparib is known to have antitumor activity in BRCA-related TNBC cells, a limited number of preclinical and clinical studies have shown antitumor efficacy of olaparib in non-BRCA-related BC (Shimo T, 2012). Understanding the biology of TNBC cells has identified molecular targets including RTK(s), such as EGFR.

Purpose: Here we tested the combination of a PARP inhibitor, olaparib (O) (AstraZeneca) plus carboplatin (C) with the EGFR/VEGFR inhibitor, vandetanib (V) (AstraZeneca) in a BRCA-wt TNBC model.

Methods: Athymic mice bearing TNBC (BRCA-wt VEGFR expressing MDA-MB231& MDA-MB468 [EGFR amplified/overexpressed]) xenograft tumors (200 mm3) were treated with O plus C in combination with V (Arms: vehicle control 1, vehicle control 2, C+O, V, C+O+V). In vitro effects of V in combination with O plus C (or temozolomide) on clonogenic growth (3D on-TOP assay), proliferation (MTT and CelltiterGLO), apoptosis (Apoptosis Array), cell signaling marker(s) (Western Blot), and tumor cell phenotypes (fibronectin-directed migration, matrigel-invasion, and vascular mimicry) were investigated in a panel of five BRCA-wt and BRCA-mutated TNBC cell lines. The effects of V were tested on (a) cell signaling marker(s), (b) angiogenesis marker (HIF-1alpha), and (c) angiogenesis related phenotypes (vitronectin-directed migration, and cord formation) in HUVEC.

Results: (1) O plus C in combination with V caused a regression of the in vivo growth of established tumors by 50% which was evident in both the BRCA-wt TNBC models tested. Interestingly, a marked suppression of the progression of tumor-growth was observed in the O plus C arm. (2) In vitro, V alone (10 µM) inhibited baseline as well as EGF-induced phosphorylation of AKT (S473/T308), S6RP, 4EBP1 and ERK. (3) TNBC cells exhibited higher sensitivity to V in clonogenic assays when combined with a 10 µM fixed dose of O and C/temozolomide. (4) A combination of V with O plus C increased cleaved caspase-3, PARP cleavage, and pro-apoptotic signals, while inhibiting vascular mimicry, migration, and invasion in MDA-MB231, MDA-MB468, and SUM149 cells. (5) Treatment with V blocked cord formation, migration, EGF-induced HIF-1α accumulation, and phosphorylation of AKT, 4EBP1, and ERK in HUVEC.

Conclusion: A profound anti-tumor efficacy of O plus C in combination with V in BRCA-wt TNBC model can be explained by a significant anti-proliferative/pro-apoptotic and anti-migratory/anti-invasive actions of the drugs (alone or in combination), as observed both in tumor cells as well as in endothelial compartments. The combination of O plus C plus V merits further investigation in TNBC.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-19-03.

Variations of antioxidative responses in two rice cultivars with polyamine treatment under salinity stress

The rice varieties viz. Nonabokra and Swarna were evaluated on the basis of their responses for oxidative stress induced by sodium chloride (NaCl) and the effects of exogenously applied polyamine thereon. Rice seedlings were treated with 200 mM of NaCl supplemented with two dosages: 1 mM and 2 mM putrescine. Following treatments, plants were evaluated for accumulation of reactive oxygen species (ROS) like O2 (-), H2O2 etc. in tissues, lipid peroxidation, protein carbonylation, accumulation of flavonoids and anthocyanin, activities of different oxidative enzymes like guaiacol peroxidase (GPX), catalase (CAT) and glutathione reductase (GR). Preliminary, oxidative stress out of salinity was ensured by plants from significantly higher accumulation of O2 (-) and H2O2 in the tissues of the NaCl treated varieties. Irrespective of varieties, there recorded a significant variation of the endogenous polyamine profiles under NaCl stress. Interestingly, exogenous application of putrescine had a close relationship on O2 (-) and H2O2 content for both the varieties. However, Nonabokra was evident as more respondent than Swarna to applied putrescine. The other effects of oxidative stress was impacted on plants as higher values of MDA content, enhanced rate of protein oxidation and putrescine recorded as an alleviating agent regardless of varieties with dose dependant manner. The generation of ROS and cellular disintegration was accompanied by up regulation of non-enzymatic and enzymatic antioxidation pathways with exogenous application of putrescine. For non-enzymatic antioxidant, it revealed that putrescine was highly effective for sustaining the anthocyanin and flavonoid content in both the varieties under salinity. Whereas, antioxidative enzyme, CAT showed its diminished activity; but activity of GPX and GR were significantly induced under salinity and it was according to the concentration of applied putrescine.

P3-18-03: In Vitro Potency of mTOR Kinase (TOR1/TOR2) Inhibitor, INK128 in ER+ and HER2 Overexpressing Breast Cancer Cells

Background

Persistent activation of the PI3K-AKT-mTOR1/2 signaling pathway drives aberrant cell growth and proliferation in a variety of tumor types including breast tumors. Recent works have demonstrated a strong association between mutational activation of PIK3CA or loss of function of PTEN and resistance to therapies targeted against the ER or HER2 pathway.

Purpose: Since PI3K-AKT-mTOR is one of the major signaling pathways responsible for the progression of breast cancer, as well as appears to be upregulated during development of the resistance to the endocrine and trastuzumab treatment, suppression of this pathway by administration of INK128 (mTOR1/2 kinase inhibitor) may therefore be efficacious in ER+ and HER2+ breast cancer models.

Experimental Design: To examine this possibility, INK128 was treated in ER+ (MCF7, BT483, T47D and MDA-MB-415), trastuzumab-sensitive HER2+ (BT474), trastuzumab-resistant (BT474HR), and PIK3CA mutated/HER2+ breast cancer cells (HCC1954 and UACC893). We have tested the effects of INK128 on the, (a) cell survival/proliferation, (b) integrin-directed cell migration, and small GTP-ase activation, (c) downstream signaling pathways for proliferation and apoptosis, and (d) 3D ON-TOP-colony formation.

Results: Treatment of ER+ and HER2+ cell lines with INK128 in vitro showed that 1) cell lines were sensitive to single agent INK128 with 50% inhibitory concentration ranging from 15 nM-10 μM in ER+ cell lines and 20 nM −50 nM in HER2+ cell lines, 2) 70–80% anti-proliferative activities were observed on 3D-ON TOP colony formation assay in both ER+ and HER2+ cells, 3) INK128 dose- and time-dependently blocked downstream effectors of mTOR1/2 pathway i.e. p-AKT (at Ser473), p-P70S6K, p-S6 ribosomal protein, p-4EBP1(interestingly, potent inhibition was also observed in cell line resistant to trastuzumab), 4) INK128 also blocked AKT phosphorylation at Thr308 (although in lesser extent than at Ser473), 5) rapalog-mediated AKT activation was blocked when cells were treated with INK128, 6) in ER+ cell lines INK128 more efficiently blocked p-4EBP1 than rapalog, 7) HER3 expression was significantly upregulated following treatment of trastuzumab-resistant cells (BT474HR) with INK128, and 8) integrin-dependent cell migration was significantly abrogated with INK128 in association with inhibition of RAC1-GTP.

Conclusion: Our preclinical in vitro data demonstrate that concurrent inhibition of mTOR1and mTOR2 is likely to be a more effective in both ER+ and HER2+ breast cancer cells than the inhibition of mTOR1 alone. We are currently studying the effect of INK128 on downstream apoptotic signals in ER+ and HER2+ cell lines, the results of which will be presented in the meeting.

INK128 was generously supplied by Inkellikine, San Diego, CA.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-18-03.

Differential Wnt pathway activation in triple negative breast cancers comparative to HER2 and hormone positive breast cancers identified from formalin-fixed, paraffin-embedded tissues

Abstract #43

Background: Patients afflicted with triple negative (TN) breast cancer (BC) are typically younger and have the worst prognosis of any BC subtype as a result of its aggressive and invasive phenotype. TN BC has been well studied with respect to the associative and prognostic values of its mRNA expression profiles. We have used the Illumina DASL (cDNA mediated, Annealing, Selection, Extension, and Ligation) platform to characterize 502 genes from 96 BC patients sourced from formalin-fixed, paraffin-embedded (FFPE) tissues. RNA extracted from FFPE tissues is highly fragmented and typically unsuited for expression platforms, but recent advances have allowed for accurate expression profiling of RNA from FFPE tissues. This 96 patient cohort included 21 TN BC patients identified by immunohistochemistry (IHC); differential analysis of TN expression was integrated with known pathway mechanisms and identified activation of the Wnt pathway in TN tumors.&#x2028; Material and Methods: The Illumina DASL assay was used to measure mRNA expression levels from BC patients obtained from St. Mary's Hospital, Montreal, Quebec. RNA was extracted from three 5µm tissue sections from FFPE blocks using the RNA High Pure Kit (Roche). Differential mRNA regulation was identified by Significance Analysis of Microarrays (SAM) software using a false discover rate (FDR, q-value &lt; 0.01) or a Bonferroni corrected two-tailed student's t-test (p-value &lt; 0.05). IHC concordance was measured by mRNA expression fold-change for positive versus negative IHC categories.&#x2028; Results: 165 samples from 96 patients were characterized for mRNA expression on 1,488 probes across 502 genes in the DASL assay. Quality control limited the analysis to 150 samples from 91 patients over 500 genes. Comparison of the TN subtype relative to HER2 positive and hormone positive breast carcinomas identified up-regulation [fold-change] of MMP7 [2.9], MMP9 [2.0], MMP1 [1.8], NOTCH1 [1.5], FZD7 [1.5], PPARD [1.3], CCND2 [1.2], MET [1.3], MYC [1.5], and MYCN [2.0] in the TN subtype. Most of these genes are either a component or downstream target of the Wnt signaling pathway. Down-regulated relevant genes included ESR1 [-8.4], PGR [-3.9], ERBB2 [-3.4] as expected, as well as ERRB3, ERBB4, GLI3, TFF1, LAF4/AFF3, and AR.&#x2028; Discussion: Down-regulation of TFF1 suggests inhibition of the ERK/MAPK pathways which have complex effects on cell-cell adhesion. In combination with over-expression of MMPs 1, 7, and 9, these changes may contribute to the invasive nature of TN BCs. GLI3 down-regulation may attenuate Hedgehog signaling potentially contributing to Wnt activation, further leading to cell migration, invasion, and decrease in cell adhesion to cognate integrin-matrix interaction Up-regulation of both the FZD7 receptor as well as the Wnt targets MMP7, MYC, MYCN, PPARD, and CCND2 strongly suggest Wnt pathway activation in the TN subtype.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 43.