bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4092: PDGFRα and β play critical roles in mediating Foxq1-driven breast cancer stemness and chemoresistance
Authors: Meng Fanyan , Speyer Cecilia , Zhang Bin , Zhao Yongzhong , Chen Wei , Gorski David , Miller Fred R. , Wu Guojun
Published: August 2015

Many epithelial-mesenchymal transition (EMT)-promoting transcription factors have been implicated in tumorigenesis and metastasis, as well as chemoresistance of cancer. However, the underlying mechanisms mediating these processes are unclear. Here we report that Foxq1, a forkhead box-containing transcription factor and EMT-inducing gene, promotes stemness traits and chemoresistance in mammary epithelial cells. Using an expression profiling assay, we identified Twist1, Zeb2, and PDGFRα and β as Foxq1 downstream targets. We further show that PDGFRα and β can be directly regulated by Foxq1 or indirectly regulated through the Foxq1/Twist1 axis. Knockdown of both PDGFRα and β results in more significant effects on reversing Foxq1-promoted oncogenesis in vitro and in vivo than knockdown of either PDGFRα or β alone. In addition, PDGFRβ is a more potent mediator of Foxq1-promoted stemness traits than PDGFRα. Finally, pharmacological inhibition or gene silencing of PDGFRs sensitizes mammary epithelial cells to chemotherapeutic agents in vitro and in vivo. These findings collectively implicate PDGFRs as critical mediators of breast cancer oncogenesis and chemoresistance driven by Foxq1, and may have important implications for the development of novel combinational therapeutics against breast cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Fanyan Meng, Cecilia Speyer, Bin Zhang, Yongzhong Zhao, Wei Chen, David Gorski, Fred R. Miller, Guojun Wu. PDGFRα and β play critical roles in mediating Foxq1-driven breast cancer stemness and chemoresistance. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4092. doi:10.1158/1538-7445.AM2015-4092
Abstract 4118: Near infrared photoimmunotherapy for lung metastases
Authors: Sato Kazuhide , Nagaya Tadanobu , Choyke Peter L. , Kobayashi Hisataka
Published: August 2015

Introduction and Purpose

Lung metastases are a leading cause of cancer related deaths. Current therapies include surgery, chemotherapy and radiotherapy but cause considerable side effects in the remaining normal lung, chest wall and heart. Therefore, a new-targeted therapy for lung metastases that results in minimal damage to adjacent structures, yet effectively treats lung metastases, is needed. Since one interesting property of the lung is that it transmits light better than other organs, light therapy is a viable alternative therapy. Near infrared photoimmunotherapy (NIR-PIT) is a new cancer treatment that combines the specificity of intravenously injected antibodies that target tumors with the toxicity induced by photosensitizers activated by NIR light. Herein, we demonstrate the efficacy of NIR-PIT in a mouse model of lung metastases.

Experimental Design

In vitro and in vivo experiments were conducted with a HER2, luciferase and GFP expressing cell line (3T3/HER2-luc-GFP). An antibody-photosensitizer conjugate (APC) consisting of trastuzumab and a phthalocyanine dye, IRDye-700DX, was synthesized. In vitro NIR-PIT cytotoxicity was assessed with dead staining, luciferase activity, and GFP fluorescence intensity. In vivo NIR-PIT was performed in a mouse model of lung metastases as well as a flank model, and assessed by tumor volume and/or bioluminescence (BLI).

Results

In vitro NIR-PIT-induced cytotoxicity was light dose dependent. In vivo anti-tumor effects of NIR-PIT included significant reductions in both tumor volume (p = 0.0141 vs. APC) and BLI (p = 0.0086 vs. APC) in the flank model, and prolonged survival (p < 0.0001). BLI demonstrated a significant reduction in lung metastases volume (p = 0.0117 vs. APC). Multiple NIR-PIT doses significantly prolonged survival in the lung metastases model (p < 0.0001).

Conclusions

NIR-PIT prolonged survival suggesting that NIR-PIT is a potential new therapy for the local control of lung metastases.

Citation Format: Kazuhide Sato, Tadanobu Nagaya, Peter L. Choyke, Hisataka Kobayashi. Near infrared photoimmunotherapy for lung metastases. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4118. doi:10.1158/1538-7445.AM2015-4118
Abstract 4135: A polyclonal origin for pancreatic cancer metastases
Authors: Maddipati Ravikanth , Stanger Ben Z.
Published: August 2015

Cancer genome studies demonstrate that tumors are comprised of multiple sub-clones with varied genetic and phenotypic properties. Metastases are often depicted as arising from these subpopulations through seeding by single cells, leading to clonally-derived lesions at distant sites. Alternatively, it has been suggested that metastases can also arise from the collective migration of tumor cells, resulting in formation of polyclonal metastases. To better understand the dynamics of metastasis formation in native tumors, we employed the multi-color “Confetti” lineage tracing system, in an autochthonous mouse model of pancreatic ductal adenocarcinoma (PDAC). Through the stochastic expression of distinct fluorescent proteins in any given cell, we tracked the contribution of different tumor subpopulations to malignant progression. We find that early pre-malignant lesions exhibit significant clonal heterogeneity but this clonal diversity decreases during progression to frank carcinoma. Furthermore our data provide the first direct evidence for polyclonal metastasis in the context of a naturally-evolving tumor and suggest that seeding and colonization of metastatic sites involves interactions between at least two distinct tumor populations. We also observe that clonal evolution during metastatic growth varies significantly between the sites of metastatic invasion, resulting in either monoclonal or polyclonal outgrowth. These results provide and unprecedented window into the dynamic changes in clonality that accompany tumor progression and suggest that heterotypic interactions between tumor subpopulations and microenvironmental factors unique to each tissue site contribute to the clonal evolution of metastases.

Citation Format: Ravikanth Maddipati, Ben Z. Stanger. A polyclonal origin for pancreatic cancer metastases. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4135. doi:10.1158/1538-7445.AM2015-4135
Abstract 4148: Tankyrase inhibition impairs directional migration and invasion of lung cancer cells by affecting microtubule dynamics and polarity signals
Authors: Lupo Barbara , Vialard Jorge , Bertotti Andrea , Lanzetti Letizia , Trusolino Livio
Published: August 2015

Tankyrases are poly(ADP)-ribose polymerases that contribute to biological processes as diverse as modulation of Wnt signaling, telomere maintenance, vesicle trafficking, and spindle pole assembly (1,2). Here we report a new function for tankyrases, namely, regulation of directional cell locomotion. Oriented migration is established by polarized reshaping of the microtubule network, which in turn is attained by phosphorylation-dependent inhibition of GSK3β at the leading edge, the ensuing association of APC with the plus end of microtubules at the cortex of cell membrane protrusions, and microtubule-based centrosome reorientation towards the migrating front (3,4).

Using a panel of lung cancer cell lines as a model system, we found that pharmacologic abrogation of tankyrase activity by two different, structurally unrelated small-molecule inhibitors weakened cell migration, invasion and directional movement induced by the motogenic cytokine HGF. Mechanistically, the anti-invasive outcome of tankyrase inhibition could be ascribed to sequential deterioration of the distinct events that govern cell directional sensing. In particular, tankyrase blockade negatively impacted: i) microtubule dynamic instability; ii) HGF-triggered GSK3β phosphorylation; iii) APC plasma membrane targeting; iv) centrosome reorientation. Collectively, these findings uncover an unanticipated role for tankyrases in influencing at multiple levels the interphase dynamics of the microtubule network and the activity and localization of related polarity signals. In perspective, these results pave the way for challenging tankyrase inhibitors as therapeutic tools to oppose dissemination and metastasis of cancer cells.

1. Riffell JL, Lord CJ, Ashworth A. Tankyrase-targeted therapeutics: expanding opportunities in the PARP family. Nat Rev Drug Discov 2012;11(12):923-36.

2. Haikarainen T, Krauss S, Lehtio L. Tankyrases: structure, function and therapeutic implications in cancer. Curr Pharm Des 2014;20(41):6472-88.

3. Etienne-Manneville S. Microtubules in cell migration. Annu Rev Cell Dev Biol 2013;29:471-99.

4. Etienne-Manneville S. Polarity proteins in migration and invasion. Oncogene 2008;27(55):6970-80.

Citation Format: Barbara Lupo, Jorge Vialard, Andrea Bertotti, Letizia Lanzetti, Livio Trusolino. Tankyrase inhibition impairs directional migration and invasion of lung cancer cells by affecting microtubule dynamics and polarity signals. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4148. doi:10.1158/1538-7445.AM2015-4148
Abstract 4179: Id3 generated cancer stem-like cells: A microvascular niche for the development of glioma
Authors: Das Jayanta , Felty Quentin H.
Published: August 2015

Pro-angiogenic vascular stem cells and angiogenesis are key events in the process of glioma formation. Vascular lesions that arise from a focal budding of endothelial cells have been associated with a poor prognosis in glioblastoma multiforme. Hyper-proliferative endothelial lesions are common in patients with severe brain tumors, however, little is known about the relevance of vascular stem cells in the development of these lesions. We tested the hypothesis that the overexpression of the inhibitor of DNA binding and differentiation protein 3 (ID3) reprograms the molecular signature of endothelial cells to stem-like cells; and we hypothesize that these stem-like cells participate in the development of vascular lesion formation in glioma. We generated ID3 overexpressing cells using the human cerebral microvascular endothelial cell line, hCMEC/D3; and determined the effect of ID3 on molecular stem-like signature and vascular lesion formation. ID3 overexpressing cells resided more in the G0/G1 phase and showed a significantly higher level of stem cell markers CD34, CD133, Oct-4, and Sox-2 than wild-type cells. ID3 overexpressing cells also showed a significant increase in VEGFR3, an endothelial growth factor receptor that has been previously reported to correlate with tumor grade of malignant gliomas. In addition, ID3 overexpressing cells showed increased levels of Pyk2, a kinase that has been shown to control glioma cell migration. In the 3-D culture model, we observed that ID3 was essential for the growth of endothelial spheroids. Our findings demonstrate that ID3 generated vascular stem-like cells have the capacity to participate in vascular lesion formation and that vascular stem-like molecular signatures are regulated in part by ID3. Furthermore, the correlation of ID3 overexpression with an increase in VEGFR3 and Pyk2 suggests the importance of ID3 in malignant glioma endothelium. Assessing ID3 in malignant gliomas on a functional level may enable a better understanding for how the microvascular niche contributes to the development of glioma. A better understanding of how microvascular lesions depend on ID3 may open new avenues for the prevention and treatment of glioma.

Citation Format: Jayanta Das, Quentin H. Felty. Id3 generated cancer stem-like cells: A microvascular niche for the development of glioma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4179. doi:10.1158/1538-7445.AM2015-4179
Abstract 4204: The cellular hierarchy of intestinal tumors
Authors: Yao Ryoji , Noda Tetsuo
Published: August 2015

Activation of the Wnt signaling is the initiating event in the majority of human colorectal cancers. In mouse models, disruption of the tumor suppressor gene, Apc, induces the adenomatous lesion. However, the analyses of initial events in animal models are hampered by difficulties to control the timing and the efficiency of introducing mutations. To overcome this problem, we used three dimensional organoid culture, which contain all epitherial components of intestinal cells with the defined organization of the crypt- and villus-like domains. In vitro 4-hydroxy-tamoxifen (4OHT) treatment of mouse organoids carrying Apc conditional mutation and CreERT2 allele led to the rapid and efficient gene aberration. Gene expression analysis revealed that the change in response to Apc inactivation was strikingly similar to those observed in the animal model. These observations demonstrated that the oragnoid culture is a useful tool to investigate the early cellular and molecular invents upon Apc inactivation.

Recent analyses identified stem cells in normal intestine as well as cancer stem cells of human colorectal cancer. We found that Apc inactivation in the intestinal organoids led to the alteration in their expression profiles in a strikingly similar manner with those in animal models. The expression levels of tested stem cell markers were increased, except Aldh1. Immunofluorescence analysis demonstrated that their elevated epressions were caused by the increase of the stem cell population. Paneth cells, which provide the stem cell niche, consistently resided with the stem cells, indicating the accelerated growth of stem cells was accompanied by the differentiation process of the normal intestine. Notably, Aldh1 was exclusively expressed in the villus-like domains, which were decreased after 4OHT treatment. In the mouse intestine, it was expressed in the villi of normal intestine, and was not detected in the adenomatous lesion. These observations demonstrated that Apc inactivation led to the expansion of crypt-like domains by altering the proliferation and differentiation program of stem cells.

Since the organoids share the features of the early response upon Apc inactivation with mouse models, they allowed detailed investigation of tumorigenesis. We have used the organoid culture system to elucidate the roles of oncogenic mutations as well as to evaluate the potential therapeutic targets.

Citation Format: Ryoji Yao, Tetsuo Noda. The cellular hierarchy of intestinal tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4204. doi:10.1158/1538-7445.AM2015-4204
Abstract 4209: Development of patient-derived xenograft (PDX) models for small cell lung cancer (SCLC) as a preclinical platform for drug development
Authors: Mullins Chelsea , Ricono Jill , Nair Praveen , Mirsaidi Cyrus , Broudy Thomas
Published: August 2015

Small cell lung cancer comprises 15-20% of all lung cancer cases, is very invasive with a high mortality rate. Although SCLC patients respond to chemotherapy, there is a high rate of recurrence with treated patients and those in advanced stage of the disease often have a refractory response to treatment. As such, the need for new treatment modalities is critical. In this work, we describe the development and characterization including histopathology, IHC and mutational analysis of 8 SCLC PDX models established from a collection of >300 small cell lung cancer specimens, many of which come from prior-treated and metastatic patients. We have also evaluated functional response of these models with in vivo pharmacology studies. Our data demonstrates the potential to use these unique PDX models in drug development for treatment of SCLC.

Citation Format: Chelsea Mullins, Jill Ricono, Praveen Nair, Cyrus Mirsaidi, Thomas Broudy. Development of patient-derived xenograft (PDX) models for small cell lung cancer (SCLC) as a preclinical platform for drug development. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4209. doi:10.1158/1538-7445.AM2015-4209
Abstract 4210: Patient-derived models of human acute myeloid and lymphoid leukemia in immunocompromised mice for preclinical drug development
Authors: Oswald Eva , Klingner Kerstin , Hammerich Benedikt , Greve Gabriele , Lenhard Dorothee , Pantic Milena , Fiebig Heinz-Herbert , Luebbert Michael , Schüler Julia B.
Published: August 2015

The generation of functional and reproducible in vivo models is a prerequisite for a better understanding of hematological malignancies and for the development of improved therapeutic strategies. Here, we report the establishment of transplantable PDX models of acute myeloid and lymphoid leukemia (AML, ALL) growing subcutaneously (s.c.) as well as in a disseminated fashion in immunocompromised mice.

Bone marrow (BM) and peripheral blood (PB) cells from 25 AML/ALL patients were injected intratibially into NSG or NOG mice (n = 1-9/patient) and in later passages also s.c. in nude mice (n = 1-3/model). Tumor growth was monitored via determination of overall survival, flow cytometry (verification of patient-derived leukemic clones by hCD34, hCD33, hCD38, hHLA-ABC, hCD3, hCD45, mCD45), and, where applicable, by caliper measurement. Engraftment is defined as ≥5% hCD45+ cells in the BM and/or ≥1% hCD45+ cells in PB. Transplantable models (higher or equal passage 2) were tested with the respective standard of care drugs (SoC) mainly Cytarabine and Dexamethasone.

Bone marrow engraftment in passage 1 was observed for 11 out of 25 leukemia models. Four of them could be established as disseminated models in serial passage. No engraftment was detected for nine models during the observation period of at least 95 days while observation for five models is still ongoing. The four established models were further characterized by fluorescence-in-situ-hybridization (FISH) to confirm patient origin. Treatment of mice bearing the models with the SoC drugs cytarabine and dexamethasone significantly prolonged overall survival. Antitumoral activity was consistent with clinical response of the donor patient. One T-ALL and two AMLs were additionally successfully propagated following s.c. injection in nude mice. They showed stable growth behavior and displayed a similar chemo-sensitivity pattern as their disseminated growing counterparts.

In conclusion, we have established a panel of transplantable PDX models of ALL and AML displaying stable and reproducible growth patterns suitable for in vivo efficacy studies. Our results confirm that PDX models of hematological malignancies replicate important clinical characteristics of the disease and are valuable tools for preclinical drug testing.

Citation Format: Eva Oswald, Kerstin Klingner, Benedikt Hammerich, Gabriele Greve, Dorothee Lenhard, Milena Pantic, Heinz-Herbert Fiebig, Michael Luebbert, Julia B. Schüler. Patient-derived models of human acute myeloid and lymphoid leukemia in immunocompromised mice for preclinical drug development. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4210. doi:10.1158/1538-7445.AM2015-4210
Abstract 4224: CD133 knockdown sensitizes melanoma to kinase inhibitors
Authors: AbdusSamad Maryam , Gaur Anirudh , Zhou Hengbo , Zapas John L. , Simbulan-Rosenthal Cynthia M. , McCarron Edward C. , Rosenthal Dean S.
Published: August 2015

Melanoma is an aggressive and lethal form of cancer, responsible for 9,710 deaths in the US every year, as indicated by the Surveillance Epidemiology and End Results (SEER) program. Although early stages are surgically treatable, the advanced or metastatic stages are the most fatal, presumably due to resistance to chemotherapy, radiation or other therapies. Refractoriness of metastatic melanoma is due to self-renewal properties of a subpopulation of resistant cells, which may be the same as what have been termed “melanoma initiating cells” (MIC), many of which have been associated with the expression CD133. CD133 (PROM-1) is a 5-transmembrane-glycoprotein that is a cell surface marker for different cancers including late-stage cutaneous melanoma. By magnetic activated cell sorting, we isolated a CD133-positive population derived from a patient harboring a difficult-to-treat NRASQ61R/BRAFWT profile. The MIC were transfected with CD133-specific small-interfering RNA (siRNAs) to deplete CD133 protein levels in cells. Our results show that knocking down CD133 in NRASQ61R/BRAFWT mutant melanoma renders cells more sensitive to clinically employed-MEK/BRAF inhibitors. Thus, specific gene knockdown or small molecule targeting, along with the multikinase inhibitors, may be a high potency therapeutic of late-stage and recurrent melanoma. Analyses of patient-derived melanomas harboring different mutation signatures are currently in progress to determine if CD133 and MIC play broader roles in melanoma chemoresistance.

Citation Format: Maryam AbdusSamad, Anirudh Gaur, Hengbo Zhou, John L. Zapas, Cynthia M. Simbulan-Rosenthal, Edward C. McCarron, Dean S. Rosenthal. CD133 knockdown sensitizes melanoma to kinase inhibitors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4224. doi:10.1158/1538-7445.AM2015-4224
Abstract 4229: ATP-binding cassette transporter ABCG2/BCRP inhibition sensitizes CD133+ cells to MEK/BRAF inhibitors
Authors: Mohamad Pauzi Abrar
Published: August 2015

Melanoma is a highly aggressive type of skin cancer. Melanoma-initiating cells (MIC) have self-renewal capacity, are highly tumorigenic and have been identified using CD133, a cell surface marker consisting of a 5-transmembrane protein. After magnetic sorting with anti-CD133 beads, we determined that CD133+ populations were more resistant than CD133- cells to MEK/BRAF inhibitors, the latter of which are targeted therapies for melanoma currently in clinical trials. In a microarray study, we found that the ABCG2 transporter is upregulated in the CD133+ MIC subpopulations. ABCG2, also known as breast cancer resistant protein (BCRP), is an ATP-binding cassette (ABC) transporter that facilitates the efflux of xenobiotics at the plasma membrane and is responsible for multidrug resistance in cancer cells. This study therefore aimed to block the ABCG2 transporter using the dual ABCG2/ABCB1 inhibitor elacridar to sensitize the CD133+ subpopulation to MEK/BRAF inhibitors. Three metastatic primary human melanoma cell lines were used to investigate the effects of inhibiting ABCG2 in drug-resistant CD133+ subpopulations. Elacridar was used for in vitro inhibition of ABCG2 prior to addition of single and combination treatments with trametinib (a MEK inhibitor), dabrafenib (a BRAF inhibitor), and mebendazole (an anthelmintic and possibly anticarcinogenic drug). Elacridar sensitized all treatment groups to drug treatment. Combination treatment using both ABCG2 and MEK/BRAF inhibitors at the lowest effective dose could be a potential therapeutic to eliminate the highly aggressive drug-resistant CD133+ MIC subpopulations.

Citation Format: Abrar Mohamad Pauzi. ATP-binding cassette transporter ABCG2/BCRP inhibition sensitizes CD133+ cells to MEK/BRAF inhibitors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4229. doi:10.1158/1538-7445.AM2015-4229
Abstract 4230: Targeting lung cancer stem cells through fatty acid metabolism
Authors: Noto Alessia , Pisanu Maria Elena , De Vitis Claudia , Malpicci Debora , Fattore Luigi , Lobello Nadia , Bonacci Barbara , Ciliberto Gennaro , Mancini Rita
Published: August 2015

Distinctive features of CSC are capacity of self renewal, increased resistance to chemotherapy and the ability to form three dimensional non adherent spheroids in appropriate conditions. We have recently demonstrated that cell cultures derived from malignant pleural effusion (MPE’s) of patients with adenocarcinoma of the lung efficiently form spheroids in non-adherent conditions supplemented with growth factors. By expression profiling, we identified 18 genes whose expression is significantly upregulated in lung tumor spheroids versus adherent cultures. Among the upregulated genes we found five genes involved in lipid metabolism. SCD1, the enzyme involved in the conversion of saturated into monounsaturated fatty acids, was one of those strongly upregulated. We demonstrated that SCD1 inhibition leads to lung cancer spheroid collapse and to the selective apoptosis of ALDH+ cells, a marker enriched in cells with stem like properties. In line with these results we demonstrated by cell sorting that ALDH positive cells were more sensitive to SCD1 inhibition than ALDH negative cells and that treatment with an SCD1 inhibitor strongly enhanced sensitivity of spheroids cells to Cisplatin. Furthermore, we observed that SCD1 inhibited spheroids were strongly impaired in their in vivo tumorigenicity. Using public datasets from lung cancer we conducted a bioinformatics analysis demonstrating that the survival rate of patients expressing SCD1-high levels was significantly lower than that of the patients expressing low level in lung adenocarcinoma. Moreover, we found that the correlation of SCD1 and stemness markers (nanog, CD44, CD24) selects the patients with bad prognosis. These results overall, indicate that SCD1 could be considered a prognostic markers for lung adenocarcinoma and a potential target for therapeutic intervention. Our studies are currently directed to dissect the mechanism pathways leading to SCD1 upregulation in lung cancer stem cells.

Citation Format: Alessia Noto, Maria Elena Pisanu, Claudia De Vitis, Debora Malpicci, Luigi Fattore, Nadia Lobello, Barbara Bonacci, Gennaro Ciliberto, Rita Mancini. Targeting lung cancer stem cells through fatty acid metabolism. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4230. doi:10.1158/1538-7445.AM2015-4230
Abstract 4247: BRCAness by MLPA is clinically useful for tailored treatment in triple-negative breast cancer
Authors: Ishikawa Takashi , Narui Kazutaka , Yamada Akimitsu , Sugae Sadatishi , Ichikawa Yasushi , Oba Mari S. , Teraoka Saeko , Kida Kumiko , Shima Hidetaka , Endo Itaru
Published: August 2015

BACKGROUBD: Cytotoxic anticancer drugs are the only clinically available agents for treating triple-negative breast cancer (TNBC). Recent gene expression analysis revealed that TNBC shows considerable overlap with basal-like tumors characterized by a potential loss of BRCA1 function. Further subdivision of TNBC represents an important clinical topic for treatments. We therefore subdivided TNBC into basal-like (BL) and non-BL subtypes defined by EGFR and/or CK5/6 positive in our previous neoadjuvant chemotherapy (NAC) study (KBOG1101 study). We reported that BL subtype were resistant to taxane regimen at AACR2013.

AIM: To examine impaired BRCA1 function “BRCAness” is beneficial for tailored chemotherapy in TNBC.

METHODS: Sixty-six TNBC cases from a randomized phase II trial comparing Docetaxel and cyclophosphamide x 6 (TC6) with 5-fluorouracil, epirubucin and cyclophosphamide followed by docetaxel (FEC-D) as NAC for hormone receptor-negative breast cancer (Kanagawa Breast Oncology Group 1101 Study). TNBC was subdivided by 1) Immunohistochemistry (IHC) of CK 5/6 and EGFR into BL and non-BL subtypes, and 2) Multiplex Ligation-dependent Probe Amplification (MLPA) of BRCAness into BRCAness and non-BRCAness subtypes. The pCR rates were examined according to each regimen and subtype. 3) The association of grade 3 pCR was examined with Ki-67, p53, aldehyde dehydrogenase (ALDH) 1 and topoisomerase 2A (topoIIα) by IHC and TOP2A by FISH for each regimen.

RESULTS: 1) The pCR rates of FEC-D and TC were 37% vs 18.5% in BL(n = 54), while 40.4% and 16.7% in non-BL (n = 11), respectively. FEC-D was superior in both subtypes without statistical significance. 2) In BRCAness (n = 34), FEC-D was significantly superior to TC6 (FEC-D vs TC: 56.3% vs 16.7%, p = 0.030), while not different in non-BRCAness (20.0% vs 16.7%). 3) No factors were associated with pCR.

DISCUSSION: TC6 was less effective than FEC-D in TNBC with BRCAness, showing that taxane cannot exert their anticancer role in tumors with BRCA1 dysfunction. Although BL may contain more BRCA1-defective tumors than non-BL, MLPA of BRCAness was better to identify subtype resistant to taxane than BL defined by IHC. BRCAness by MLPA method is practically useful for treatment selection in TNBC.

Citation Format: Takashi Ishikawa, Kazutaka Narui, Akimitsu Yamada, Sadatishi Sugae, Yasushi Ichikawa, Mari S. Oba, Saeko Teraoka, Kumiko Kida, Hidetaka Shima, Itaru Endo. BRCAness by MLPA is clinically useful for tailored treatment in triple-negative breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4247. doi:10.1158/1538-7445.AM2015-4247
Abstract 4265: Identification of new NTRK1 gene fusion as oncogene target in colon cancer
Authors: Creancier Laurent , Dejean Caroline , Vandenberghe Isabelle , Blanchet Jean-Christophe , Aussagues Yannick , Annereau Jean Philippe , Selves Janick , Kruczynski Anna
Published: August 2015

In an effort to better characterize the activity of a multi-kinase inhibitors, antiproliferative activity was evaluated against a panel of human tumor cell lines. Among the different cell lines tested we have been able to highlight that the KM12 human colorectal carcinoma present hypersensitivity to inhibition. By intersecting the results of activity of the compound and the bibliographic data, we could confirm that the activity of the compound was mediated by the inhibition of phosphorylation of the receptor NTRK1.

The NTRK1 gene encodes Tropomyosin-related kinase A (TRKA), the hight-affinity Nerve Growth Factor Receptor. NTRK1 was originally isolated from a human colon carcinoma as a transforming oncogene activated by a somatic rearrangement that fused TPM3 (non-muscle tropomyosin) gene to kinase domain of a novel tyrosine-kinase receptor. The KM12 human CRC cell line expresses the chimeric TPM3-TRKA protein and is hypersensitive to TRKA kinase inhibition.

Using differential quantitative reverse transcriptase PCR and optimised immunohistochemistry we could confirm the existence of low frequency (0.5%) NTRK1 re-arranged / activated forms in colorectal carcinoma. A same colorectal tumor sample could contain different fusion transcripts, highlighting the molecular heterogeneity of this type of tumor Furthermore we detect a novel NTRK1 fusion in colorectal carcinoma clinical samples corresponding to oncogenic rearrangement TRK-T2 identified in papillary thyroid carcinoma.

These results confirm the potential interest of the target NTRK1 in the panel of targeted therapies against colorectal cancer.

Citation Format: Laurent Creancier, Caroline Dejean, Isabelle Vandenberghe, Jean-Christophe Blanchet, Yannick Aussagues, Jean Philippe Annereau, Janick Selves, Anna Kruczynski. Identification of new NTRK1 gene fusion as oncogene target in colon cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4265. doi:10.1158/1538-7445.AM2015-4265
Abstract 429: Novel role of CXCL12/CXCR4 signaling axis in obesity-induced prostate cancer progression in HiMyc mice
Authors: Saha Achinto , Blando Jorge , DiGiovanni John
Published: August 2015

Obesity has been shown to increase prostate cancer (PCa) progression and disease severity in men. In previous studies, we showed that diet-induced obesity (DIO, 60 kcal% fat) increased the incidence and severity of invasive adenocarcinomas in HiMyc transgenic mice compared to mice on a control diet (10 kcal% fat) whereas calorie restriction (30% CR) completely prevented the formation of adenocarcinomas. Increased tumor progression was associated with changes in expression of a large number of cytokines, chemokines and growth factors suggesting that altered growth factor and inflammatory signaling pathways in the tumor microenvironment may be key targets for preventing and controlling PCa progression and especially obesity-related PCa progression. Therefore, in this study we investigated the role of white adipose tissue (WAT)-derived factors on obesity-driven PCa progression in HiMyc mice. We first isolated RNA from the stromal vascular fraction (SVF) of the periprostatic WAT from HiMyc mice maintained on DIO and control diet. qPCR analyses showed a dramatic increase in expression of various chemokines, cytokines, growth and angiogenesis factors in the SVF of obese HiMyc mice. Among them, both CXCL12 and its receptors CXCR4 and CXCR7, were significantly upregulated in SVF from obese HiMyc mice. Recently, we developed a PCa cell line from the ventral prostate of HiMyc mice (HMVP2 cells) and a normal cell line from FVB/N mice (NMVP cells). Two additional cell lines (HMVP2A1 and HMVP2A2) were isolated from the original HMVP2 cells after subsequent tumor formation in FVB/N mice and growth in culture. HMVP2 and the derivative cell lines have characteristics of cancer stem cells and produce tumors in syngeneic mice. Western blot analyses showed expression of both CXCR4 and CXCR7 in the following order HMVP2A2 >HMVP2A1> HMVP2>NMVP cells, which followed their ability to produce tumors in vivo. Furthermore, CXCL12 treatment stimulated migration and invasion of HMVP2 cells (but not NMVP cells), which was inhibited by the CXCR4 antagonist, AMD3100. CXCL12 treatment also led to rapid activation of Akt, Stat3 and NFκB signaling in HMVP2 but not in NMVP cells. These data suggest that CXCL12 has differential effects on PCa cells from HiMyc mice compared to normal prostate cells that may play a role in driving tumor progression. In addition, these data suggest that targeting the CXCL12/CXCR4/CXCR7 axis could lead to novel approaches for offset the effects of obesity on PCa progression, thereby reducing PCa mortality.

Citation Format: Achinto Saha, Jorge Blando, John DiGiovanni. Novel role of CXCL12/CXCR4 signaling axis in obesity-induced prostate cancer progression in HiMyc mice. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 429. doi:10.1158/1538-7445.AM2015-429
Abstract 4297: mAbXcite: A novel immunotherapy platform that initiates a robust anti-cancer immune response by recruiting and activating neutrophils
Authors: Sansal-Castellano Isabelle , Carlson Mark , Armstrong Todd , Reznik Gabriel , Siedlecki James , Kane John , Dostalova Zuzana , Miao Hua , Jaffee Elizabeth , Rubin-Bejerano Ifat
Published: August 2015

The recent successes in the immunotherapy field demonstrate that a successful immune response to cancer can lead to meaningful anti-tumor responses. Antibodies blocking immune checkpoint molecules (e.g. CTLA4, and PD-1) lead to effective T cell responses especially in tumors that are immune active.

Immune cells that have not received as much attention in cancer immunotherapy are neutrophils. Neutrophils are the most abundant white blood cells, which protect us from microbial infections. They are the first line of innate defense: they arrive early on in the course of infection, phagocytose, and release the content of their granules, including reactive oxygen species and enzymes. Neutrophils also communicate with other immune cells, such as macrophages, dendritic cells, and T cells, by releasing cytokines and chemokines.

There has long been a call to recruit these professional killers to fight cancer. However, an approach that mediates the recruitment of neutrophils has to lead to acute as opposed to chronic inflammation to overcome the suppressive environment that tumors surround themselves with.

We have developed a novel immunotherapy platform technology, termed mAbXcite, which directs and activates neutrophils to kill cancer cells in a targeted manner. The targeting is achieved by using monoclonal antibodies that are chemically linked to beta-1,6-glucan, a saccharide found on the cell walls of fungal species which recruits and activates neutrophils. The resulting mAb construct attracts mediators of acute inflammation, notably neutrophils, leading to rapid destruction of cancer cells.

We will present proof-of concept of the mAbXcite technology using an anti-EGFR antibody and a syngeneic antibody. mAbXcite-cetuximab demonstrates significantly greater efficacy than the original antibody in resistant tumor models (BRAF and KRAS). Furthermore, mice that show complete regression or stasis do not grow tumors upon rechallenge, suggesting a lasting immune response that is initiated by neutrophils. We will also provide evidence for the involvement of T cells, suggesting that the immune memory is a result of neutrophils naturally leading to T cell activation.

Citation Format: Isabelle Sansal-Castellano, Mark Carlson, Todd Armstrong, Gabriel Reznik, James Siedlecki, John Kane, Zuzana Dostalova, Hua Miao, Elizabeth Jaffee, Ifat Rubin-Bejerano. mAbXcite: A novel immunotherapy platform that initiates a robust anti-cancer immune response by recruiting and activating neutrophils. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4297. doi:10.1158/1538-7445.AM2015-4297
Abstract 431: Active secretion of CXCL10 and CCL5 from colorectal cancer microenvironments associates with GranzymeB+ CD8+ T-cell infiltration
Authors: Zumwalt Timothy J. , Boland C. Richard , Goel Ajay
Published: August 2015

T-cell infiltration varies among colorectal tumors and directly impacts patient survival. Chemoattraction and infiltration of CD8+ T-cells are mediated by surface chemokine receptors CXCR3 and CCR5, and are associated with favorable prognosis. Transcriptional expression of these receptors’ cognate chemokines, as well as other inflammation-associated chemokines, correlate with prolonged disease-free survival (DFS). These findings, however, were derived from paraffin embedded tissues, thus little is known about the pattern of secreted T-cell targeting chemokines from colorectal tumors. Therefore, this investigation aimed to determine the secretion pattern of chemokines associated with DFS from immediately excised live tumor tissues. Our results demonstrate the first real functional analysis of chemokine activity in colorectal tumors beyond immunohistochemistry and real-time PCR. Forty-four colorectal tumors were procured immediately after surgery and categorized by transcriptional expression of two T-cell marker genes that represent the magnitude of type-1 T-cell activity. Tumors that more highly co-expressed IFNG and TBX21 consequently have a higher frequency of infiltrating GzmB+ CTLs and IFN-γ+ CD4+ helper T-cells and transcribe a unique pattern of DFS-associated chemokines when compared to normal mucosa. High co-expression of IFNG and TBX21 was bimodally distributed across the tumors collected. Tumors with higher co-expression more strongly secreted two DFS-associated chemokines, CXCR3 ligand, CXCL10 and CCR5 ligand, CCL5. Additional results demonstrate that tumors with higher co-expression are proportionally skewed towards early TMN stages and with mismatch repair-deficiency, confirming that infiltration of CD8+ T-cells are associated with early TNM stages and lack of metastasis. Secreted chemokines were detected using a novel immunoassay that may have implications for future development of immunopotentiating treatments in cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Timothy J. Zumwalt, C. Richard Boland, Ajay Goel. Active secretion of CXCL10 and CCL5 from colorectal cancer microenvironments associates with GranzymeB+ CD8+ T-cell infiltration. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 431. doi:10.1158/1538-7445.AM2015-431
Abstract 4316: hMENA11a contributes to HER3-mediated resistance to PI3K inhibitors in HER2 overexpressing breast cancer cells
Authors: Trono Paola , Di Modugno Francesca , Circo Rita , Spada Sheila , Melchionna Roberta , Palermo Belinda , Panetta Mariangela , Matteoni Silvia , Soddu Silvia , De Maria Ruggero , Nisticò Paola
Published: August 2015

Human Mena (hMENA), an actin regulatory protein of the ENA/VASP family, cooperates with ErbB receptor family signaling in breast cancer. It is overexpressed in high-risk preneoplastic lesions and in primary breast tumors where it correlates with HER2 overexpression and an activated status of AKT and MAPK. The concomitant overexpression of hMENA and HER2 identifies breast cancer patients with a worse prognosis. hMENA is expressed along with alternatively expressed isoforms, hMENA11a and hMENAΔv6 with opposite functions.

By Reverse Phase Protein Assay, we identified a novel role for the epithelial associated hMENA11a isoform in sustaining HER3 activation and pro-survival pathways in HER2 overexpressing breast luminal cancer cells. Since HER3 activation is crucial in mechanisms of cell resistance to PI3K inhibitors, we explored whether hMENA11a is involved in these resistance mechanisms. The specific hMENA11a depletion switched off the HER3-related pathway activated by PI3K inhibitors and impaired the nuclear accumulation of HER3 transcription factor FOXO3a induced by PI3K inhibitors. On the other hand, PI3K inhibitors activated hMENA11a phosphorylation and affected its localization. At the functional level, we found that hMENA11a sustains cell proliferation and survival in response to PI3K inhibitor treatment whereas hMENA11a silencing increases molecules involved in cancer cell apoptosis. As shown in three-dimensional cultured breast cancer cells hMENA11a contributes to cancer cells resistance to PI3K inhibition since the depletion of hMENA11a drastically reduced cell viability upon treatment with PI3K inhibitor BEZ235.

Altogether, these results indicate that hMENA11a in HER2 overexpressing breast cancer cells sustains HER3/AKT axis activation and contributes to HER3-mediated resistance mechanisms to PI3K inhibitors. Thus, hMENA11a expression can be proposed as a marker of HER3 activation and of resistance to PI3K inhibition therapies, to select patients who can benefit from these combined targeted treatments. hMENA11a activity may represent a new target for anti-proliferative therapies in breast cancer.

Citation Format: Paola Trono, Francesca Di Modugno, Rita Circo, Sheila Spada, Roberta Melchionna, Belinda Palermo, Mariangela Panetta, Silvia Matteoni, Silvia Soddu, Ruggero De Maria, Paola Nisticò. hMENA11a contributes to HER3-mediated resistance to PI3K inhibitors in HER2 overexpressing breast cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4316. doi:10.1158/1538-7445.AM2015-4316
Abstract 4318: Dexamethasone variably protects triple negative breast cancer cells against paclitaxel depending on relative cellular levels of glucocorticoid receptor alpha
Authors: Labbe Roselyne , Speyer Cecilia , Bukhsh Miriam , Belfiori Austin , Khansa Rafa , Patki Mudgha , Ratnam Manohar , Gorski David
Published: August 2015

Introduction: Triple negative breast cancer (TNBC) comprises 15-20% of all breast cancer cases and is unresponsive to the drugs used to treat ER+/PR+ or HER2+ breast cancers. The only treatment option for TNBC is chemotherapy with paclitaxel being a major component. However, many patients respond poorly and develop side effects that are routinely treated with dexamethasone. In certain cancers, dexamethasone attenuates chemotherapy response by inhibiting apoptosis or temporarily arresting cell growth. Dexamethasone's actions are mediated through glucocorticoid receptor alpha (GR alpha), which is ubiquitous. Here we examine the protective effect of dexamethasone in TNBC cells and the relationship of this effect to variability in cellular GR alpha levels.

Methods: GR alpha expression was measured in TNBC cell lines and related to dexamethasone's ability to affect their growth and resistance to paclitaxel. Cell lines analyzed included those expressing low levels of GR alpha and recombinant cells in which GR alpha expression was ectopically restored.

Results: A positive association was observed between endogenous GR alpha expression and dexamethasone's ability to protect TNBC cells against paclitaxel. Overexpression of GR alpha in cells expressing low endogenous GR alpha conferred protection against paclitaxel in the presence of dexamethasone. In contrast to reported observations in other cancer cell types, dexamethasone increased cell proliferation and transcriptional activation of thymidylate synthase, an S-phase enzyme. These results suggest the use of dexamethasone may be one factor responsible for the poor response of TNBC patients to traditional chemotherapy and suggest using GR alpha expression level as a biomarker for predicting which TNBC patients should be given traditional chemotherapy.

Citation Format: Roselyne Labbe, Cecilia Speyer, Miriam Bukhsh, Austin Belfiori, Rafa Khansa, Mudgha Patki, Manohar Ratnam, David Gorski. Dexamethasone variably protects triple negative breast cancer cells against paclitaxel depending on relative cellular levels of glucocorticoid receptor alpha. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4318. doi:10.1158/1538-7445.AM2015-4318