bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3620: LIV-1 antibody-drug conjugate: A novel therapeutic agent for breast and prostate cancer
Authors: Sussman Django , Nesterova Albina , Westendorf Lori , Duniho Steven , Anderson Martha , Mbow Brianna , Gregoire Ashley , Hunter Joshua H. , Whiting Nancy , Corey Eva , Vessella Robert L. , Benjamin Dennis R. , Smith Leia M.
Published: June 2012

LIV-1, also known as SLC39A6 or ZIP6, is a member of the zinc transporter family and was first identified as an estrogen-inducible gene in breast cancer. LIV-1, as a downstream target of STAT3, promotes the epithelial to mesenchymal transition that is important in the malignant progression to metastasis. Consistent with its role in cancer, we determined by immunohistochemical (IHC) analysis that LIV-1 is expressed by estrogen receptor-positive (ER+), hormone-treated tumors (both primary and metastatic sites) and ER-/PR-/Her2- (triple-negative) breast cancers. Hormone refractory metastatic prostate tumor samples express Liv-1, with expression confirmed in both bone and soft tissue metastatic sites by IHC. In healthy human tissues, LIV-1 expression is limited to hormonally-regulated organs (prostate, uterus, and breast). The broad expression of LIV-1 in prostate and breast cancer tumors in combination with the limited expression in vital organs makes LIV-1 an excellent target for an antibody-drug conjugate (ADC). We generated an ADC consisting of a humanized anti-LIV-1 mAb conjugated to the antitubulin agent monomethyl auristatin E (MMAE), via a plasma stable, enzyme-cleavable linker (vc). The humanized LIV-1 mAb bound with high affinity to both human and cynomolgous LIV-1. In vitro, anti-LIV-1-vcMMAE ADCs showed specific cytotoxic activity against a breast cancer cell line. In vivo studies also demonstrated antitumor activity of anti-LIV-1-vcMMAE ADCs in preclinical xenograft models with significant delay of tumor growth compared to control groups. These findings demonstrate that further evaluation and development of anti-LIV-1-vcMMAE is warranted as a promising and potential therapeutic agent for the treatment of prostate and ER+ and triple-negative breast cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3620. doi:10.1158/1538-7445.AM2011-3620
Abstract 3635: Improved efficacy of HER2 targeted-immunotoxins using photochemical internalization (PCI)
Authors: Berstad Maria Eb , Berg Kristian , Rosenblum Michael , Cao Yu , Marks James D. , Weyergang Anette
Published: June 2012

Human epidermal growth factor receptor 2 (HER2) is overexpressed in several cancers (breast, ovary, stomach, colon and esophagus) and is an attractive target for delivery of cancer therapeutics. However, both primary and acquired resistance to current anti-HER2 therapies is of major clinical concern and calls for more effective HER2 targeted treatment strategies. We here present photochemical internalization (PCI) of HER2 targeted immunotoxins (ITs) as a novel treatment strategy for HER2 positive cancers. PCI has been shown to result in release of macromolecular therapeutics entrapped in endocytic vesicles. The method is based on photosensitizers (PSs) which localize to the membranes of endocytic vesicles, and subsequent membrane rupture upon light exposure so that the drugs can escape into the cytosol. The purpose of this study was to evaluate photochemical internalization (PCI) of HER2 targeted immunotoxins (ITs) with various binding sites and affinities. ITs were constructed by chemically coupling the monoclonal HER2 antibody, trastuzumab, to a type I ribosome inactivating protein (RIP), saporin, through a biotin-streptavidin linkage, or by genetically fusing human single-chain antibodies (scFv) to recombinant gelonin, another type I RIP. The cytotoxic effect of PCI of the ITs was assessed against HER2 positive Zr-75-1 and BT-20 cells and HER2 negative MDA-MB231 cells. The present data confirm synergistic cytotoxicity of PCI of trastuzumab-based and HER2 scFv-based ITs compared to treatment with ITs and photodynamic therapy (PDT) alone (PS+light). At LD50-PDT a subtoxic dose of 100pM of the different ITs was sufficient to kill 75-85% of Zr-75-1 cells. LD95 of PCI of the recombinant fusions was detected between 1 and 10nM of all 4 ITs (subtoxic dosage) at a photodynamic dose reducing the viability of the BT-20 cells to 50%. PCI of the ITs was shown to be much more effective compared to PCI of the respective toxins alone, as no significant increase in toxicity was found by PCI of 0.1nM of the toxins. Animal model studies to assess the ability of PCI to augment the efficacy of immunotoxins are ongoing. These studies suggest that the selectivity of HER2-based ITs may be further improved by the addition of an independent, selective strategy such as PCI which augments efficacy only in tumor cells.

Research Conducted, in part, by the Norwegian Cancer Society and the Clayton Foundation for Research.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3635. doi:10.1158/1538-7445.AM2011-3635
Abstract 3646: The role of myeloid-derived suppressor cells in tumor development
Authors: Ortiz Myrna L. , Cheng Pingyan , Luetteke Noreen , Youn Je-In , Gabrilovich Dmitry I.
Published: June 2012

Myeloid-derived suppressor cells (MDSC) play an important role in regulation of immune response in cancer. They also have been implicated into promotion of tumor metastases and angiogenesis. We asked what role if any these myeloid cells can play in tumor formation associated in inflammation. To address this question we used previously described S100A9 deficient and S100A9 transgenic mice. S100A9, also known as calgranulin B or myeloid related protein 14 (MRP14), is a member of the S100 family of Ca2+ binding proteins. Previous studies have established that up-regulation of this protein in hematopoietic progenitor cells results in inhibition of dendritic cell maturation and accumulation of MDSC. We tested the role of MDSC in skin tumor formation using TgAC transgenic mice. These mice have activated k-ras mutation in keratinocytes. Upon topical treatment with 12-O-tetradecanoyl phorbol-13-acetate (TPA) they develop skin papillomas. We generated double transgenic mice and demonstrated that in mice overexpressing S100A9 the frequency and number of papillomas increased dramatically comparing with wild-type TgAC mice. The formation of papillomas was also significantly accelerated. To confirm the critical role of myeloid cells in the observed effect we used bone marrow transfer from wild-type or S100A9 Tg mice into lethally irradiated TgAC mice. Transfer of S100A9 Tg bone marrow cells resulted in significantly more rapid and more extensive formation of papillomas in TPA treated mice than transfer of control bone marrow. To assess effect of TPA treatment on cell infiltrate into skin wild-type or S100A9Tg mice were treated with TPA for 3 weeks. Skin from S100A9Tg mice had significantly higher number of Gr-1+ myeloid cells and CD4+ T cells than skin from wild-type mice. No differences in F4/80 macrophages and CD11c+ dendritic cells were seen. To further evaluate the possible role of MDSC in tumor formation we treat control and S100A9 knockout (KO) mice with combination of carcinogen DMBA and TPA using accelerated skin carcinogenesis protocol. The absence of S100A9 substantially delayed the onset of papilloma and decreased the number of lesions as compared with wild-type mice. These results suggest that MDSC may play an important role in inflammation associated tumoregenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3646. doi:10.1158/1538-7445.AM2011-3646
Abstract 3648: S100A9 play a role in MDSC expansion and migration but not in their activation
Authors: Condamine Thomas , Cheng Pingyan , Youn Je-In , Ortiz Myrna L. , Vogl Thomas , Roth Johannes , Gabrilovich Dmitry I.
Published: June 2012

S100A9 is a pro-inflammatory molecule, secreted by myeloid cells, which has been reported to recruit leukocytes to the sites of inflammation or tumors. Up-regulation of S100A9 expression in myeloid progenitor cells was implicated in inhibition of DC differentiation and promotion of expansion of myeloid-derived suppressor cells (MDSC). These cells have been well described as a major component used by the tumor to be protected from the immune system. In order to determine if extracellular and intracellular S100A9 has similar effects on myeloid cell differentiation and function, we evaluated the effect of recombinant S100A9. Our results demonstrated that in contrast to overexpression of S100A9 in hematopoietic progenitor cell (HPC), the treatment of HPC with recombinant S100A9 did not affect their differentiation to mature macrophages, or dendritic cells. The same treatment does not affect the suppressive activity of MDSC purified from naïve or tumor-bearing mice either. However, recombinant S100A9 had strong chemotactic effect on MDSC. Interestingly, its effect on immature myeloid cells isolated from naïve tumor-free mice was substantially lower. Recently, it has been suggested that MDSC need two different signals: one – required for their expansion and inhibited differentiation of mature myeloid cells and the other one – for activation. Our data suggest that S100A9 may mediate first signals but not the second one. Intracellular up-regulation of S100A9 promotes expansion of MDSC and contributes to block of their differentiation, whereas extracellular S100A9 via cell receptors induce MDSC migration. A better understanding of how MDSC migrate into the tumor and how S100A9 is involved in this process could lead to the generation of new treatment aiming to block the migration of MDSC inside the tumor.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3648. doi:10.1158/1538-7445.AM2011-3648
Abstract 3673: Expression profile of phosphorylated proteins from the mTOR and Fyn/RSK2 signaling pathways in solar UV-induced skin carcinogenesis
Authors: Bermudez Yira , Stratton Steven P. , Bowden George T. , Dong Zigang , Bode Ann M. , Curiel-Lewandrowski Clara , Warneke James A. , Hurst Craig A. , Lang Julie E. , Alberts David S. , Einspahr Janine G.
Published: June 2012

Chronic sun exposure is considered the main etiologic agent of non-melanoma skin cancer (NMSC). Inactivation of tumor suppressor p53 and activation of key oncogenic signaling pathways important in cell proliferation and transformation are considered crucial steps in the development of NMSC. Therefore, our overall hypothesis is that topically administered small molecule drugs can modulate specific targets in ultraviolet (UV)-induced signaling cascades resulting in attenuation or reversal of carcinogenic events in human skin. In the study herein, we evaluate the modulation of solar light-activated mTOR and Fyn/RSK2 signaling pathways in normal human skin and solar simulated light (SSL)-irradiated human skin to determine the expression profiles of upstream and downstream phosphorylated proteins p38 (Thr180/Tyr182), p44/42 MAPK (Thr202/Tyr204), histone H3 (Ser10), p90RSK (Thr359/Ser363), Akt (Ser473), mTOR (Ser2448), S6 ribosomal protein (Ser235/236), and 4E-BP1 (Thr37/46). The study population consisted of individuals 18 years or older in general good health with skin types II-III. SSL irradiation at various doses ranging from two to four times the minimal erythema dose (MED) was applied to unexposed skin. Punch biopsies were taken at baseline, 5 minutes, 1 h, 5 h, and 24 h post-irradiation and immediately fixed in 10% formalin. Tissues were evaluated by immunohistochemistry for the expression of phospho-proteins. Proliferating cell nuclear antigen (PCNA) and cleaved caspase 3 (Asp175) were evaluated as markers for keratinocyte proliferation and apoptosis, respectively. Marked SSL-induced changes in human epidermis were seen in the expression of phosphorylated histone H3, S6 ribosomal protein, and 4E-BP1 at 1 h, 5 h, and 24 h post-SSL as compared to control. A linear increase in phosphorylated p44/42 MAPK expression was observed at 1 h, 5 h, and 24 h post-SSL as compared to control. Phosphorylated Akt expression increased post-SSL, and appears dependent on duration and intensity of SSL exposure. Ultimately, the expression profile patterns of phosphorylated proteins in the mTOR and Fyn/Rsk2 pathways will be used to determine activity of new and selective chemoprevention agents being developed to target these SSL-induced skin carcinogenesis pathways.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3673. doi:10.1158/1538-7445.AM2011-3673
Abstract 3698: Chemopreventive efficacy of pioglitazone on lung cancer in mice
Authors: Wang Yian , James Michael , Wen Weidong , Lu Yan , Szabo Eva , Lubet Ronald A. , You Ming
Published: June 2012

Pioglitazone is a ligand of PPARγ nuclear receptor. Activation of PPARγ has been associated with anticancer activities in a variety of cancer cell lines through inhibition of proliferation and promotion of apoptosis. We examined the effect of pioglitazone, which is approved for the treatment of type II diabetes mellitus, on lung cancer development in carcinogen-induced non-small cell lung cancers in mice. When pioglitazone was administered beginning 8 weeks after the first dose of carcinogen treatment, pioglitazone significantly inhibited tumor load (sum of tumor volume per lung in average) by 64% (P < 0.05) in p53(wt/wt) mice and 50% (P < 0.05) in p53(wt/Ala135Val) mice in the lung adenocarcinoma model. Delayed administration of pioglitazone caused a limited (35%, P < 0.05) decrease in lung squamous cell carcinoma. Induction of apoptosis occurred in both model systems. These data show that pioglitazone significantly inhibited progression of both adenocarcinoma and SCC in the two mouse model systems.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3698. doi:10.1158/1538-7445.AM2011-3698
Abstract 3700: Proteomic credentialing in a model for chemoprevention studies of urinary bladder cancer
Authors: Townsend Reid R. , Rohrs Henry , LeDuc Richard , Malone James P. , Erdman-Gilmore Petra , Hill Donald L. , Grubbs Clinton J. , You Ming , Lubet Ronald A.
Published: June 2012

Molecular markers for the development and response of tumors to agents are essential for efficacy assessment of cancer chemoprevention. The discovery, verification and validation of biomarkers for tumor monitoring require animal models that have been shown to share molecular features with human cancers. At the transciptomic level, the rat 4-hydroxybutyl(butyl) nitrosamine (OH-BBN) model has been shown to share many of the pathways that are commonly activated in human bladder cancer. To qualify the model at the proteomics level, global protein analyses on bladder tumors and on paired urine samples were performed, and the findings correlated with transcriptomic data and literature knowledge of upregulated proteins in human bladder cancer. We used a high-resolution LC-MS platform that consisted of optimized, reproducible sample preparation methods for tissue and urinary proteins, robust nano-LC hybrid (linear quadrupole-Orbitrap) mass spectrometry, and a data analysis pipeline to align and annotate differential peptides from LC-MS analyses of multiple samples. To date, samples from ∼ 150 individual animals have been analyzed using this quantitative proteomics platform. We have used this platform to correlate urinary candidate abundances with tumor burden and response to chemopreventive agents. In one experiment that compared the urine from control and tumor-bearing animals, it was found that 3,032 of the 15,557 detected peptides changed by > 3-fold. Among the proteins that were only detected in tumor-bearing animals (at least a 1000 fold increase) were Annexins (I, II and VII), S-100 proteins-4, 6 and 11, calpactin and galectin.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3700. doi:10.1158/1538-7445.AM2011-3700
Abstract 375: The cellular distribution and related response of different peptide modified gold nanoparticles in cervical cancer cells
Authors: Tsai Tsung-Lin , Wu Ping-Ching , Hou Chia-Cheng , Li Ying-Ying , Shieh Dar-Bin , Su Wu-Chou
Published: June 2012

Nanoparticles (NPs) are ideal vectors to deliver analytic probes or therapeutic agents into cells and subcellular compartments. Among many nanomaterials, gold NPs is widely used as a model platform for biomedical research because of their favorable physical and chemical properties. Thus, gold NPs has been employed for various applications, especially in medicine. Through surface modification of gold NPs with functional bio-macromolecules (i.e., peptides, nucleic acids and antibodies) may improve the ability of imaging, clinical diagnostics and therapeutics. Cellular uptake of gold NPs is highly dependent on their size, shape, and surface properties. For targeted therapy, the common strategy for specific cells or cellular compartments delivery is to modify NPs with peptides or lignads. The outcome is highly dependent on the peptide sequence and cell types. Therefore, we treated CaSKi, HeLa and SiHa cervical cancer cells with different peptide-modified gold NPs for 24 hours and determined the cellular localization of the NPs from laser confocal microscopy equipped with DIC channel. We found that gold NPs modified with the nuclear localization signal (NLS) peptide from SV40 virus (GNP-PEG/SV40) accumulated around the cytoplasmic side of nuclear membrane (perinuclear accumulation) in CaSKi and HeLa carcinoma cells and translocate into nucleus in SiHa squamous cells. For adenovirus (ADV) peptide modified NPs (GNP-PEG/ADV), nuclear localization was observed in all cervical cancer cells. We then performed cell survival test (MTT assay) for various time intervals (24 to 96 hours) to identify the relationship between NPs’ distribution and cellular response. The particles exhibited perinuclear and nuclear accumulation decreased cell survival greater than cell and particles control (GNP-PEG) did. For perinuclear accumulation in HeLa cells, through annexin V/PI stain, there was no increase in apoptosis after long-term treatment with GNP-PEG/SV40 particles, but a significant increase in LC3-II expression in the GNP-PEG/SV40-treated group, suggesting activation of autophagy. On the contrary, an apoptotic cell population was found in nuclear accumulated SiHa cells. These findings suggest that different cellular distribution of NPs may link with specific death pathways. In conclusion, this study may have implications in the development of new therapeutic modality for specific cancer cells or prevention of long-term toxicities from treatment with different peptide modified NPs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 375. doi:10.1158/1538-7445.AM2011-375
Abstract 3861: Bladder cancer-associated gene expression signatures identified by profiling of exfoliated urothelia
Authors: Rosser Charles J. , Urquidi Virginia , Liu Li , Sun Yijun , Whiting Bryant , Villicana Patrick , Goodison Steve
Published: June 2012

PURPOSE: Bladder cancer is the fifth most commonly diagnosed malignancy in the United States and one of the most prevalent worldwide. It harbors a probability of recurrence of >50%; thus, rigorous, long-term surveillance of patients is advocated. Flexible cystoscopy coupled with voided urine cytology is the primary diagnostic approach, but cystoscopy is an uncomfortable, invasive procedure and the sensitivity of voided urine cytology is poor in all but high-grade tumors. We sought to define a robust genetic signature that can be used to diagnose bladder cancer in a non-invasive manner.

METHODS: Gene expression microarrays were utilized to analyze the transcript profiles of 52 urine samples from subjects with bladder tumors and 40 subjects without bladder tumors (cohort I). Data from microarrays containing 56,000 targets were subjected to a panel of statistical analyses to identify bladder cancer-associated gene signatures. Hierarchical clustering and supervised learning algorithms were used to classify samples on the basis of tumor burden. Furthermore, supervised machine learning and a cross-validation approach were used to build a 40-gene molecular classifier which was then validated in voided urine samples by quantitative PCR (qPCR) in an independent group of patients (cohort II – 46 subjects with bladder cancer and 37 subjects without bladder cancer).

RESULTS: Hierarchical clustering classified normal urothelium and bladder cancer with 84% accuracy. A genetic profile consisting of 40 probes was identified in those patients (cohort I) with bladder cancer. In an independent experiment, 14 of the 40 genes indentified above were validated in voided urine samples by qPCR in cohort II. Utilizing this 14 gene signature, the diagnostic accuracy of detecting bladder cancer was 81%.

CONCLUSION: Our results show that it is possible to achieve the detection of bladder cancer using molecular signatures present in exfoliated tumor urothelia. Further investigation and validation of the cancer-associated profiles in a diverse cohort may reveal important biomarkers for the detection and surveillance of bladder cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3861. doi:10.1158/1538-7445.AM2011-3861
Abstract 4017: DLC1 and α-catenin protein interaction enhances DLC1 antioncogenic activity by stabilizing adherens junctions and suppressing NFκB signaling
Authors: Tripathi Veenu , Zimonjic Drazen B. , Popescu Nicholas C.
Published: June 2012

Adherens junctions (AJs), which are cell-cell adhesion complexes closely associated with actin cytoskeleton, play an important role in maintaining epithelial tissue homeostasis. Both malignant transformation, and tumor progression to metastasis are often associated with major changes in cytoskeletal organization, the cell-cell adhesion, and aberrant adhesion-mediated signaling. The tumor suppressor gene DLC1 (Deleted in Liver Cancer 1) encodes a RhoGTPase activating protein (GAP) that acts as a negative regulator of the Rho family of small GTPases, which are implicated in cytoskeleton organization and regulation of AJs. A yeast two-hybrid screening identified α-catenin, a component of AJs, as a potential DLC1's binding partner. We relied on this finding and investigated the role of DLC1 in the regulation of AJs and in adhesion-mediated signaling. Using human embryonic kidney (HEK 293) cells we demonstrated that DLC1 interacted with α-catenin and associated with E-cadherin and β-catenin, both constitutive AJs proteins. Co-immunoprecipitation using various deletion constructs of DLC1 and of α-catenin established that the N-terminal (340-435 aa) of DLC1 interacted with the N-terminal (39-161 aa) of α-catenin. Immuno-fluorescence staining and western blot of cellular membrane and cytoplasmic fractions, demonstrated that binding of DLC1 to α-catenin recruited α-catenin to the plasma membrane and required DLC1 GAP activity. In contrast, the DLC1 GAP mutant (R718E) failed to produce the same effect. Fluorescence Recovery After Photobleaching (FRAP) analysis demonstrated that DLC1-α-catenin interaction increased the GFP-E-cadherin mobility at cell-cell junctions, whereas phalloidin staining showed intact actin cable formation around the cell periphery, resulting in the stabilization of AJs. The DLC1-α-catenin interaction is instrumental for a maximal oncosuppressive effects of DLC1 (i.e., by inhibiting proliferation and abolishing colony formation of prostate carcinoma cells); DLC1 mutant defective for α-catenin binding failed to reproduce such an effect. Loss of α-catenin is usually accompanied by an increase in the activation of NFkB, which is associated with increased cell proliferation and resistance to apoptosis. We demonstrated that, by immobilizing NFkB to the AJ complex, DLC1-α-catenin interaction effectively inhibited NFkB phosphorylation and, therefore, its activation. Together, these results unravel a new mechanism through which DLC1 exerts its oncosuppressive function by stabilizing AJs and suppressing NFkB signaling.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4017. doi:10.1158/1538-7445.AM2011-4017
Abstract 4410: Initiative for Molecular Profile and Advanced Cancer Therapy (IMPACT): A personalized medicine Phase I clinical trials program at MD Anderson Cancer Center
Authors: Tsimberidou Apostolia M. , Hong David S. , Wheler Jennifer , Fu Siqing , Piha-Paul Sarina , Naing Aung , Falchook Gerald , Luthra Raja , Iskander Nancy G. , Wen Sijin , Kurzrock Razelle
Published: June 2012

Introduction: Ongoing clinical trials are based on targeting specific pathways in addition to the tumor histology. We examined the results of mutational analyses performed in patients with advanced cancer seen in the Phase I clinic at The University of Texas MD Anderson Cancer Center.

Methods: Mutational analysis was mostly performed in the Clinical Laboratory Improvement Amendments (CLIA)-certified pathology laboratory of MD Anderson. DNA was extracted from microdissected paraffin-embedded tumor samples, and analysis was performed on specific exons, depending on the test ordered, for the following genes: PIK3CA (exon 9: codons 532-554; exon 20: codons 1011-1062); BRAF (exon 15: codons 595 to 600); KRAS and NRAS (codons 12, 13, and 61); EGFR (exons 18 to 21 of the kinase domain); KIT (exons 9, 11, 13, and 17); and RET (exon 10: codons 609, 611, 618, and 620; codon 634 of exon 11; codon 918 of exon 16). The loss of the tumor suppressor nuclear protein, PTEN, was determined using immunohistochemical staining.

Results. Tumor mutational analysis was ordered for 952 patients. Overall, 103 patients did not have adequate tissue. Of the remaining 849 patients, 354 (41.69%) had ≥ 1 mutation and 495 did not have a mutation. More women (45%) than men (38%) had a mutation (p = 0.02), but age was not associated with the presence of mutations (p=0.76). Of the patients with mutations, 313 had 1 mutation, 38 had 2 mutations, and 3 had 3 mutations. The distribution of mutations by diagnosis is shown in the Table. The total distribution of mutations in our patient population was as follows: BRAF, 19.01%; KRAS, 18.74%; PIK3CA, 9.85%; NRAS, 8.17%; EGFR, 3.38%; KIT, 2.13%; and PTEN loss, 21.20%.

Conclusion: Testing for PIK3CA, KRAS, NRAS, BRAF, EGFR, KIT, and RET mutations and PTEN loss in 849 patients with available tissue demonstrated that molecular driver aberrations are common in advanced cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4410. doi:10.1158/1538-7445.AM2011-4410
Abstract 4449: Deep penetration of PDT drugs into tumors via non-covalent drug-gold nanoparticle conjugates
Authors: Meyers Joseph D. , Cheng Yu , Broome Ann-Marie , Kenney Malcolm E. , Burda Clemens , Basilion James P.
Published: June 2012

In 2010, more than a million new cancer cases are expected to be diagnosed with half resulting in death, at an NIH estimated total yearly cost of $263.8 billion. Therefore, there is a critical need to improve both cancer diagnostics and therapeutics; future theranostics aim to combine both in a single visit. Consequently, efficient delivery of hydrophobic, theranostic drugs is necessary. This study presents a novel non-covalent PDT cancer drug-gold nanoparticle (Au NP) conjugate system that is able to perform rapid drug release deep into tumors within hours rather than days. The drug delivery mechanism of the PDT drug Pc 4 using Au NPs into tumors by passive accumulation was investigated via fluorescence imaging of Pc 4, elemental gold analysis, and histological staining. The pharmacokinetics of the conjugates over a 7 day period showed rapid drug excretion, as monitored via the fluorescence of Pc 4 which decreased significantly to near baseline levels. Moreover, the biodistribution of Au NPs indicated clearance of the conjugates from the mice. The spleen, liver, kidneys, and urinary tract showed accumulation of Au NPs and accounted for 33.6% of the injected dose at only 4 hrs, suggesting possible excretion pathways, since the total injected dose of Au NPs recovered from dissected organs decreased by 33.4%. Histological analysis corroborated these findings; Au NPs in the liver were found in liver sinusoids and hepatocytes, Au NPs in the spleen were found near macrophages, Au NPs in the kidney were located in the glomerulus, and Au NPs in the urinary tract were found in the stroma. At 4 hrs post-injection, ∼76% of the injected dose of Au NPs was recovered in harvested organs, and AuNPs accumulated passively in tumors with an average accumulation of 8 ± 6 % ID (or ∼62.46 μg/g of tumor tissue). The tumor (4 hrs post-injection) showed very high fluorescence intensities further suggesting the passive accumulation of Pc 4 via the Au NPs within the tumor. In vitro studies showed the conjugates delivered 389.4 moles of Pc 4 per mole of Au NP into cells in 4 hrs; in vivo studies showed approximately 10 RFUs (of Pc 4)/ μg of gold delivered into tumor tissues. Ultimately, this study suggests that Pc 4 non-covalently loaded Au NPs that penetrate deep into the tumor interior provide a very attractive approach to delivery cancer drugs to visualize carcinomas and track therapeutic responses.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4449. doi:10.1158/1538-7445.AM2011-4449
Abstract 4470: Kevetrin™, a novel small molecule, activates p53, enhances expression of p21, induces cell cycle arrest and apoptosis in a human cancer cell line
Authors: Kumar Ashok , Hiran Tej , Holden Sylvia A. , Chafai-Fadela Karima , Rogers Samantha , Ram Siya , Menon Krishna
Published: June 2012

We have previously shown that Kevetrin, a small molecule currently under development, has potent antitumor activity in human multi-drug resistant carcinoma xenograft models while being well tolerated. To investigate the mechanism of action for its potent antitumor activity, we assessed Kevetrin's effect on apoptosis, cell cycle progression, including underlying molecular mechanisms.

Here we report that Kevetrin strongly induced cell cycle arrest and apoptosis in a human lung adenocarcinoma cell line (A549) using the TUNEL assay and FACS analysis; similar results were observed using a human breast carcinoma cell line (MDA-MB-231). Treatment of A549 cells with 400 µM of Kevetrin for 48 hours resulted in G2/M phase cell cycle arrest that was associated with a marked decline in levels of G2/M regulatory proteins, including CDK1 and cdc25B, and increased expression of Wee1. Further, Kevetrin-mediated growth inhibition of A549 correlated with apoptosis induction that was characterized by cleavage of procaspase-3 and poly (ADP-ribose) polymerase (PARP).

The p53 tumor suppressor is a well characterized transcription factor controlling cell growth and apoptosis during times of cellular stress. The tumor suppressor p53 inhibits tumor growth primarily through its ability to induce apoptosis. In cancer development, the resistance of cells to apoptosis is one of the crucial steps. The reactivation of p53 in tumor cells should trigger massive apoptosis and eliminate the tumor. Interestingly, Kevetrin treatment caused enhanced activated p53 levels in A549 cells. Activation of p53 can lead to cell cycle arrest and apoptosis. Western blotting revealed a concentration dependent increase in phosphorylation of p53 at serine 15. The phosphorylation of p53 at serine 15 leads to reduced interaction between p53 and its negative regulator, the oncoprotein MDM2. We also found that Kevetrin increased expression of p53 target genes such as p21 (Waf1). The tumor suppressor protein p21 (Waf1) acts as inhibitor of cell cycle progression. Finally, we also found that p53 induced apoptosis by inducing the expression of PUMA.

Our study shows that Kevetrin activates p53 functions in tumor cells. Thus Kevetrin is a strong candidate as an anticancer drug that targets p53. Based on our studies we plan to initiate a Phase I clinical trial in 2011.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4470. doi:10.1158/1538-7445.AM2011-4470
Abstract 4479: Targeting non-small cell lung cancer cells harboring a PIK3CA mutation by a novel and oral PI3K selective inhibitor, PF-4989216
Authors: Walls Marlena , Mehta Pramod P. , Baxi Sangita M. , Liu Kevin , Li Chunze , Smeal Tod , Yin Min-Jean
Published: June 2012

Aberrant phosphatidylinositol 3-kinase (PI3K)/AKT signaling occurs commonly in cancer. Gene mutation, amplification, and copy number gains of the PI3K catalytic subunit p110α have been shown in a variety of human cancers. The tumor suppressor phosphatase and tensin homologue deleted on chromosome 10 (PTEN) dephosphorylates the 3-phosphoinositides and is frequently mutated, deleted, or down-regulated in many cancers to constitutively activate the PI3K pathway. In response to activation, PI3Ks phosphorylate membrane phosphatidylinositides to generate phosphatidylinositol 3,4,5-triphosphate (PIP3); PIP3 serves as an secondary messenger activating AKT and 3’-phosphoinositide-dependent kinase-1 (PDK1). Phosphorylation of AKT at threonine-308 (T308) by PDK1 and serine-473 (S473) by mTORC2 fully activates the AKT pathway to regulate various cellular processes including cell growth, proliferation, survival, and metabolism.

Several inhibitors targeting the PI3K pathway have been developed in preclinical discovery or clinical trials; however, a small molecule inhibitor has not yet been approved for cancer treatment. Most inhibitors have inhibitory activity against both PI3Ks and mTOR kinases. The mTORC1 and mTORC2 complexes control critical pathways regulating cell proliferation, apoptosis, angiogenesis, and metabolism through AKT-dependent and AKT-independent mechanisms. Therefore, agents targeting PI3K with additional mTOR kinase inhibitory activities may carry extra toxicity through the disruption of mTOR function in normal cells. To develop a drug selectively targeting PI3K, we have identified PF-4989216 as a novel potent and selective PI3K inhibitor. In this study, we describe the in vitro and in vivo anti-tumor activity of PF-4989216 in human non-small-cell lung cancer cells (NSCLCs). PF-4989216 inhibits the phosphorylation of PI3K downstream molecules and subsequently leads to inhibition in cell proliferation and xenograft tumor growth in NSCLCs harboring a PIK3CA mutation, including an erlotinib resistant line, NCI-H1975. Although PF-4989216 inhibits the phosphorylation of PI3K downstream molecules in the NSCLCs with PTEN loss (NCI-H1650), PF-4989216 does not sufficiently induce anti-tumor efficacy in NCI-H1650. Our results suggest that there may be a different tumorigenesis mechanism between PIK3CA mutation and PTEN loss in NSCLCs, and indicate that PF-4989216 is a potential cancer drug candidate for erlotinib resistant non-small-cell lung cancer patients with PIK3CA mutation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4479. doi:10.1158/1538-7445.AM2011-4479
Abstract 4504: PF-04449913, a small molecule inhibitor of Hedgehog signaling, is effective in inhibiting tumor growth in preclinical models
Authors: Jackson-Fisher Amy J. , McMahon Melissa J. , Lam Justine , Li Chunze , Engstrom Lars D. , Tsaparikos Konstantinos , Shields David J. , Fang Douglas D. , Lira Maruja E. , Zhu Zhou , Robbins Michael D. , Schwab Richard , Munchhof Michael J. , VanArsdale Todd
Published: June 2012

Aberrant activation of the Hedgehog (Hh) signaling pathway has been implicated in several human cancers. Mutations in the Patched (PTCH1) gene are responsible for basal cell nevus syndrome, and are commonly found in sporadic basal cell carcinoma and in medulloblastoma. In this study we evaluated PF-04449913, an inhibitor of the Hh signaling pathway, in a Ptch1+/-p53 mouse model of medulloblastoma and in human patient derived xenograft models. Treatment of Ptch1+/-p53+/- or Ptch1+/-p53-/- medulloblastoma allografts with PF-04449913 produced potent dose-dependent inhibition of Hh pathway activity resulting in stable tumor regression. Using Gli1 transcript levels as a surrogate for Hh pathway activity, the pharmacodynamic effects of PF-04449913 were evaluated in medulloblastoma allografts following single dose and multi dose administrations of compound. PF-04449913 treated medulloblastoma allografts had reduced levels of Gli1 gene expression and down regulation of genes linked to the Hh signaling pathway. PF-04449913 was also effective when combined with a chemotherapeutic agent in a colon patient derived xenograft model and a pancreatic patient derived xenograft model, resulting in 63% and 73% tumor growth inhibition respectively. Collectively, our study demonstrates the therapeutic efficacy of a small molecule inhibitor of Hh pathway in preclinical models of multiple cancer types in either single or combination treatments.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4504. doi:10.1158/1538-7445.AM2011-4504
Abstract 4520: Targeting galectin-1 with PTX-008 inhibits invasion, tumor growth and metastasis in human carcinoma models
Authors: Astorgues-Xerri Lucile , De Groot Diane , Serova Maria , Huet Eric , Menashi Suzanne , Riveiro Maria E. , Cvitkovic Esteban , Noel Kay , Raymond Eric , Faivre Sandrine
Published: June 2012

Background. Galectin-1 belongs to a phylogenetically conserved family of carbohydrate binding lectins (galectins) that share a conserved carbohydrate recognition domain and are involved in tumor growth and metastasis. The aim of this study was to evaluate the effect of galectin-1 inhibition by shRNA or PTX-008, a topomimetic of antiangiogenic drug Anginex, on in vitro cancer cells invasion and on in vivo tumor growth and metastasis development.

Material and Methods. In vitro invasion was evaluated using Matrigel assay. Transfection of SQ20B head&neck cancer cells with galectin-1 shRNA was done using the Santa Cruz Biotechnology protocol. In xenograft studies, cells were injected s.c. into female nu/nu athymic mice either treated with vehicle or 10mg/kg PTX-008 i.p. daily for 3 weeks. Measurements were done twice a week, tumor volume was determined as 3.14(width2)/length.

Results. PTX-008 demonstrated potent antiproliferative effects on galectin-1 expressing SQ20B cells with IC50 of 3.8µM. Transfection of SQ20B cells with shGal1 (SQ-shGAL1) did not change proliferation of cells. In contrast, shGAL1 and PTX-008 significantly decreased invasion in matrigel assays. SQ20B and SQ-shGAL1 cells were injected in nude mice and SQ20B mice were treated continuously with PTX-008. Targeting galectin-1 with PTX-008 as well as inhibiting endogenous galectin-1 by shRNA inhibited significantly tumor growth in mice. Similar results with inhibition of tumor growth were obtained using A2780-1A9 ovarian xenografts treated with 5 and 10 mg/kg PTX-008. Subcutaneous injections of SQ20B in mice result in the development of multiple subcutaneous metastases. Interestingly, PTX-008 treated SQ20B-xenograft mice and mice with SQ-shGAL1 implanted tumors had respectively 80% and 50% decreased numbers of secondary tumors as compared to control groups. After treatment, tumors were isolated and analyzed for expression of galectin-1 by RT-PCR and western blot analysis. Interestingly, treatment with PTX-008 seems to inhibit the protein level of galectin-1 in SQ20B xenografts. In addition, tumors treated with PTX-008 expressed lower VEGFR2 and CXCR4 mRNA levels as compared to control tumors, suggesting antiangiogenic properties of PTX-008. The study of molecular mechanisms implicated in galectin-1-induced inhibition of tumor growth and metastasis development is in progress.

Conclusion. Our findings suggest that targeting galectin-1 by PTX-008 may be an effective approach to treat cancer patients and to prevent secondary tumor development.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4520. doi:10.1158/1538-7445.AM2011-4520
Abstract 4664: The effect of neoadjuvant androgen deprivation therapy on long-term outcome after radical prostatectomy
Authors: Payne Ondracek Rochelle D. , Hayn Matthew H. , Poch Michael A. , Ray Michael J. , Davis Warren , Curtis Alexandra , Kim Hyung L. , Morrison Carl D. , Marshall James R. , Mohler James L.
Published: June 2012

Neoadjuvant androgen deprivation therapy (NADT) was championed for men treated with radical prostatectomy (RP) for high risk prostate cancer (CaP) in the early 1990s. Although NADT improved neither surgical margin positivity nor progression-free survival, it continues to be part of some clinical trials. The effect of NADT on long term outcome was evaluated using modern aggressiveness and failure criteria among 720 patients treated with RP at Roswell Park Cancer Institute between 1993 and 2005. Among RP patients, 125 received NADT. NCCN pre-surgery risk categories were low in 36 (29%), intermediate in 54 (43%), and high or very high in 35 (28%). Clinical and pathological aggressiveness indicators included clinical Gleason sum, clinical tumor stage (2002 TNM), highest preoperative PSA, pathological Gleason sum, pathological tumor stage (2002 TNM) and surgical margin status. Ten post-RP recurrence definitions were considered: 1) at least 1 detectable PSA, 2) at least 2 detectable PSAs, 3) PSA>0.2 ng/ml, 4) PSA>0.4 ng/ml, 5) at least 1 post RP treatment (chemotherapy, hormone, radiation), 6) PSA doubling time <9 months, 7) NCCN definition of failure, 8) AUA definition of failure, 9) development of metastatic CaP, 10) death from CaP. In bivariate analysis, men treated with NADT were 105% (p<0.0001) more likely to fail using the AUA definition, 202% (p=0.004) more likely to develop metastatic CaP, and 673% (p=0.001) more likely to die of CaP. The increased risk of recurrence persisted for NADT in multivariate analysis, despite control for all clinical and pathological parameters; the table shows data for clinical and pathological parameters that have been associated with RP failure. Analysis of hazards regression for AUA failure across NCCN risk category demonstrated that NADT was detrimental for men treated with RP, regardless of any level of risk.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4664. doi:10.1158/1538-7445.AM2011-4664
Abstract 4710: p53 regulates epithelial-mesenchymal transition (EMT) and stem cell properties through modulation of miRNAs
Authors: Chao Chi-Hong , Chang Chun-Ju , Xia Weiya , Yang Jer-Yen , Xiong Yan , Li Chia-Wei , Hung Mien-Chie
Published: June 2012

Epithelial mechenchymal transition (EMT) has recently been linked to stem cell phenotype. However, the molecular mechanism involving regulation of EMT and stemness remains elusive. Here, using unbiased genomic approaches, we discovered that tumor suppressor p53 plays a critical role in regulating both EMT and EMT-associated stem cell properties through transcriptional activation of miR-200c. p53 transactivates miR-200c through direct binding to miR-200c promoter. Loss of p53 in human mammary epithelial cells leads to decreased expression of miR-200c and activates EMT program, accompanied by increased mammary stem cell population. Re-expressing miR-200c suppresses gene targets that mediate EMT and stemness properties and thereby converts mesenchymal/stem cell-like phenotype caused by loss of p53 to differentiated epithelial cell phenotype. Furthermore, loss of p53 negatively correlates with miR-200c level but positively with increased expression of EMT and stemness markers as well as high tumor grade in a cohort of breast cancer samples. Together, this study elucidates a novel role of p53 in regulating EMT/MET and stemness/differentiation plasticity and reveals a potential therapeutic implication to suppress EMT associated-cancer stem cells through activation of p53-mediated miR-200c pathway

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4710. doi:10.1158/1538-7445.AM2011-4710