bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 714: Survivin expression in patients with resected pancreatic adenocarcinoma
Authors: Khan Saad A. , Yang Donghua , Zhu Fang , Dubyk Cara , Tejani Mohamed , Cohen Steven J. , Hoffman John P. , Burtness Barbara A.
Published: August 2012

Introduction: Pancreatic cancer remains highly refractory to treatment and biomarkers of treatment responsiveness are urgently needed. Survivin is an inhibitor of apoptosis and one such potential marker. Undetectable in most normal differentiated and non-proliferating tissues, it is highly expressed in cancer. We measured pancreatic cancer survivin expression and examined its association with differential treatment response. Methods: We constructed 4 pancreatic cancer tissue microarrays with 1mm duplicate cores using tumor samples from 88 resected pancreatic cancer patients at our center. They were then followed with 60 patients receiving chemotherapy or radiation, both as adjuvant therapy and also for palliative treatment upon recurrence. We measured survivin expression using highly quantitative automated immunofluorescence via AQUA R(HistoRx, Branford CT). Scores were individually reported for the nuclear, cytoplasmic and total cellular compartments, and validated by the pathologist. Results: Median survivin AQUA scores were: nuclear 5838 (range 2126-13728), cytoplasm 4177 (2173-9914) and total 4543 (2120-10344). Survivin expression was significantly higher in nodal specimens compared to primary tumor in nucleus (p=0.02), cytoplasm (p=0.006) and in total (p=0.0095). Higher cytoplasmic survivin correlated with higher grade (p=0.03), and primary tumor location in head compared to body or tail (p=0.03). There was a trend toward higher nuclear survivin in younger (p=0.08) and female patients (p=0.08). Disease-free survival (DFS) was significantly longer in patients with high compared to low nuclear survivin (p=0.048), using median as the cut-off. This effect was greater for patients treated with gemcitabine (p=0.0481) than those treated with 5-FU (p=0.0698) or radiation therapy (p=0.094). Overall survival for all patients was not different in the higher than median group compared to lower group patients (p=0.300). There was a trend toward longer overall survival (OS) for patients whose tumors had high nuclear survivin in those treated with fluorouracil (p=0.0856), gemcitabine (p=0.0868) or radiation therapy (p=0.0862). Discussion: Survivin expression is higher in nodal metastases than primary resected pancreatic cancer tumors and is associated with particular clinical and pathologic characteristics. High nuclear survivin expression is associated with longer DFS in patients with resected pancreatic cancer. This effect is most pronounced in patients treated with gemcitabine. Further examination of survivin in a larger series of pancreatic cancers is warranted.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 714. doi:1538-7445.AM2012-714
Abstract 720: Identification of novel molecular markers for detecting lymph node metastasis of oral squamous cell carcinoma
Authors: Oka Ryota , Nakashiro Koh-ichi , Goda Hiroyuki , Tanaka Hiroshi , Hamakawa Hiroyuki
Published: August 2012

Cervical lymph node metastasis is a potent prognostic factor in oral squamous cell carcinoma (OSCC). Management of occult metastasis is an important issue for the surgeons. Sentinel lymph node biopsy (SLNB) is highlighted for its role in deciding making of neck dissection. We have performed the SLNB for cN0 cases routinely and reported the clinical usefulness. Accurate diagnosis of the metastasis in sentinel lymph nodes is important but depends on a heavy workload of the pathologist. We carried out a clinical study to evaluate a novel automated assay system for cytokeratin 19 (CK19) mRNA, the one-step nucleic acid amplification (OSNA) method, to detect the lymph node metastasis of OSCC. The accuracy of OSNA assay was nearly 95%, but it could not detect occult metastasis in case of no or low expression of CK19 mRNA in the primary tumor. In this study, we attempted to identify novel molecular markers to find the harboring cancer cells in the lymph node. First, we determined the gene expression profiles in 7 metastatic lymph nodes from patients with OSCC, 1 benign lymph node, and 5 salivary gland tissues from non-cancerous patients by microarray analysis. We found the overexpression of 36 genes in all metastatic lymph nodes but not in benign lymph node and salivary glands. Subsequently, we examined the expression of these genes in newly 15 metastatic lymph nodes and 9 benign lymph nodes by real-time quantitative RT-PCR method. Among the 36 genes, the expression of annexin A8-like 2 (ANXA8L2) and desmoglein 3 (DSG3) was commonly detected in metastatic lymph nodes at much higher level but not in benign lymph nodes at all. Furthermore, we retrospectively evaluated the usefulness of these markers with the use of 330 lymph nodes that were histopathologically metastasis-positive in 62 and metastasis-negative in 268. The accuracy of each marker CK19, ANXA8L2 and DSG3 is all near 90%. However, the combination of these markers improved the sensitivity up to 96-100%. Expression of ANXA8L2 and DSG3 was also detected in approximately 3% of the histopathologically metastasis-negative lymph nodes. These results suggested that ANXA8L2 and DSG3 could be useful molecular markers and improve detection rate of occult metastasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 720. doi:1538-7445.AM2012-720
Abstract 722: Significance of p16 in site-specific HPV-positive and HPV-negative HNSCC
Authors: Stephen Josena K. , Divine George , Chen Kangmei , Chitale Dhananajay , Havard Shaleta , Worsham Maria J.
Published: August 2012

Expression of p16INK4A (p16+ve) is highly correlated with human papilloma virus (HPV) infection in head and neck squamous cell carcinoma (HNSCC), however, p16-positivityis not limited to HPV-positive (HPV+ve) tumors and therefore, not a perfect surrogate for HPV. Also, p16+ve status has a strong relationship with survival and treatment outcomes in HNSCC, which is best documented for the oropharyngeal site (OP); non-OP sites such as the oral cavity (OC), larynx, and hypopharynx (HP) are understudied. The goal of this study was to evaluate p16 in the context of HPV and examine p16 survival outcomes in HPV+ve and HPV-negative (HPV-ve) site-specific HNSCC. The cohort of 80 primary HNSCC consisted of 10 HPV16+ve and 10 HPV16-ve cases each for four sites: OC, OP, larynx and HP. Expression of p16 was significantly different across sites (p<0.001), being more frequent in OP (65%) than in non-OP sites (13%). The frequency of p16 expression was different (p=0.031) between Caucasian Americans (CA, 38%) and African Americans (AA, 16%) similar to HPV (CA 65% vs AA 37%, p=0.013). p16+ve patients had improved survival for all sites combined and for the OP subgroup (similar to HPV+ve cases). However, subgroups defined by both HPV and p16, indicate that patients with p16-negative (-ve)/HPV-ve status had the worst survival for all sites combined as well as for OP. Cohorts with larger representations of non-OP sites examining multiple molecular markers will be key to deciphering and dissecting out p16's role as a useful prognostic indicator when assessed in combination with HPV status

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 722. doi:1538-7445.AM2012-722
Abstract 727: Homozygosity for Arg of p53 codon 72 correlates with poor prognosis in Puerto Rican patients with head and neck squamous cell carcinoma
Authors: Rivera Bianca L. , Baez Adriana
Published: August 2012

Objective: Genetic variations at codon 72 of p53 gene results in altered activities for p53 and are suggested as a potential cancer risk. However, epidemiologic findings have been inconsistent. The p53 gene has a polymorphic site at exon 4 codon 72, which, in an occurrence of a base substitution, can produce Proline or Arginine (Arg72Pro). This polymorphism is differentially dispersed among different ethnic populations. The objective of this study is to evaluate the association between p53 polymorphism and head and neck squamous cell carcinoma (HNSCC) in the Puerto Rican population. Methods: Genotyping of the p53 polymorphism at exon 4 codon 72 was performed using PCR-based restriction fragment polymorphism (PCR-RFLP) in a study with 72 HNSCC patients. Correlations between clinicopathological parameters and p53 polymorphism were analyzed by Fisher's exact test and chi-square when suitable. Survival analysis of HNSCC patients, with each type of p53 genotype, was performed using Mantel-Cox test. Results: The frequencies for homozygote Arg allele were 34.7% in HNSCC cases and 31.1% in controls. The Pro allele carriers (Arg/Pro or Pro/Pro) had a frequency of 65.3% in HNSCC cases and 68.9% in healthy controls. The OR of HNSCC cancer-associated with the Arg-Arg genotypes of codon 72 was 1.18 [95% confidence interval (CI): 0.53-2.61]. Survival analysis showed that HNSCC patients with the Arg/Arg allele had a poorer survival rate compared to patients with the Pro allele (Hazard Ratio = 2.40, 95% CI: 1.27-4.56, P=0.0074). Also, there were differences in survival based on patient's genotype and response to treatment. However, no statistically significant association was found between p53 polymorphic variants and gender, age, risk factors and staging. Conclusion: Our results suggest that homozygosity for Arg of p53 Arg72Pro may have a role in the progression of HNSCC in the Puerto Rican population. Detection of the p53 polymorphic variants may be used as an indicator of prognosis in HNSCC patients. Accurate prognosis in HNSCC will help clinicians to establish proper treatment and increase the survival of HNSCC patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 727. doi:1538-7445.AM2012-727
Abstract 728: CXCL12 (SDF-1) chemokine expression as a baseline factor associated with resistance to induction chemotherapy in head and neck squamous cell carcinoma
Authors: Halimi Caroline , Albert Sébastien , Tijeras-Raballand Annemilai , Astorgues-Xerri Lucile , Couvelard Anne , Hourseau Muriel , Riveiro Maria Eugenia , Serova Maria , Raymond Eric , Faivre Sandrine J.
Published: August 2012

Background. SDF-1, and its cognate receptor CXCR4, are recognized as major factors in tumor progression and metastasis. Recent data also suggest that chemokines may play a role in resistance to chemotherapy. In this study, we investigated the expression of SDF-1 and CXCR4 in initial tumor biopsies prior to treatment in patients treated by induction chemotherapy for organ preservation and correlated this expression with response to chemotherapy. Material and Methods. Patients with locally advanced pharyngo-laryngeal carcinomas, candidates for neoadjuvant platinum-based chemotherapy as part of an organ preservation program, were considered for this study. Objective response in organ preservation accounted for more than 50% reduction in tumor size on CT-scan or MRI. Tissue biopsies were scored for SDF-1, CXCR4, Vimentin and E-cadherin staining by immunohistochemistry. Staining was measured according to a specific scoring scale. Biopsies were all read by three different observers for scoring adjudication and quantification was performed using the Histolab Software (Microvision). Results. Among the 42 patients who entered in this study, 23 had primary site in the hypopharynx and 19 in the larynx. Twenty-two patients experienced objective response and 20 patients were non-responders to induction chemotherapy. SDF-1 staining score was higher in cancer cells than that in normal epithelial cells located in the close vicinity of the tumor. SDF-1 staining was predominantly located in the cytoplasm of cancer cells. The level of SDF-1 expression was significantly higher in tumors from non-responders compared to responders (score: 155 vs 110, p=0.01). CXCR4 expression was similar between responders and non-responders, and predominantly located in the cytoplasm and the nucleus of cancer cells. Vimentin and E-cadherin were evaluated as potential differentiation markers. Few tumor cells expressed Vimentin in our biopsies. Interestingly lower E-cadherin expression was observed in non-responders compared to responders (score: 110 vs 170, p=0.01) suggesting that loss in epithelial differentiation may facilitate resistance to chemotherapy in this population. Conclusion. High expression levels of SDF-1 cytokine and the loss of E-cadherin as a marker of epithelial differentiation in cancer cells were shown to correlate with the lack of response to induction chemotherapy in hypopharyngeal and laryngeal squamous cell carcinomas.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 728. doi:1538-7445.AM2012-728
Abstract 733: Clinicopathological significance of CXCL12/CXCR4 expression in esophageal squamous cell carcinoma
Authors: Uchi Yusuke , Takeuchi Hiroya , Matsuda Sachiko , Kawakubo Hirofumi , Nakamura Rieko , Takahashi Tsunehiro , Wada Norihito , Saikawa Yoshiro , Ohmori Tai , Kitagawa Yuko
Published: August 2012

Background: Chemokines are known to be small weight cytokines which regulate variety of immune responses. It is also known that they and their receptors express in several cancers and correlate to progression of primary and metastatic cancer. The chemokine CXCL12 and its receptor CXCR4 especially have been reported to play prominent role in proliferation, metastasis, and prognosis of several cancers, including breast, ovarian, kidney, prostate, brain, and lung cancers. However, reports about the relationship between CXCL12/CXCR4 expression and esophageal squamous cell carcinoma (ESCC) are rare. This retrospective study is to investigate the expression of CXCL12/CXCR4 and explore its correlation to prognosis and clinicopathological factors of ESCC. Methods: The relationship between CXCL12 and CXCR4 expression and clinicopathological factors including prognosis in surgical specimens of primary tumors in 77 patients with ESCC was investigated immunohistochemically. All patients had R0 or R1 resection without any preoperative treatment from 1997 to 2007. We evaluated the intensity of the stain in 3 grades (0: negative, 1: weak, 2: strong), and the proportion of stained cancer cells in 4 high power fields in 4 grades (0: 0∼10%, 1: 10∼40%, 2: 40∼70%, 3: 70∼100%). The CXCL12/CXCR4 expression score was defined as the product of the intensity score by proportion score, and the positive expression was defined as ESCC of which expression score is 1 or over. Results: The positive expression rate of CXCL12 was 77% and that of CXCR4 was 57%. The expression of CXCL12 and CXCR4 had no correlation. The disease free survival rate was significantly lower in patients with positive CXCL12 expression (p=0.037), and the overall survival rate was lower in Stage I/II patients with positive CXCL12 expression (p=0.50). The expression of CXCR4 had no correlation with clinicopathological variables and prognosis. Multivariable analysis showed that CXCL12 expression score was the independent risk factor for the recurrence of ESCC (p=0.013), as same as pathological N factor and venous invasion. Conclusion: This study indicated that positive CXCL12 expression was more related to the recurrence of ESCC, compared with CXCR4 expression. Evaluation of CXCL12 expression is useful for predicting prognosis in patients with ESCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 733. doi:1538-7445.AM2012-733
Abstract 734: Frequency and type of epidermal growth factor receptor mutation in basaloid squamous cell carcinoma of the upper aerodigestive tract
Authors: Cho Kyung-Ja , Chun Sung-Min , Roh Jong-Lyel , Choi Seung-Ho , Nam Soon Yuhl , Kim Sang Yoon , Kim Sung Bae
Published: August 2012

Recent reports on nonsmall cell lung cancer (NSCLC) that epidermal growth factor receptor (EGFR) mutation status predicts response to EGFR-tyrosine kinase inhibitor (TKI) treatment signifies the importance of molecular footprint of EGFR. The mass array system has emerged as a more sensitive and economical method of mutation typing than direct sequencing. Basaloid squamous cell carcinoma (BSCC) is an aggressive variant of squamous cell carcinoma of the upper aerodigestive tract. We observed unexceptional EGFR expression in this type of malignancy by immunohistochemistry, and 23 cases (8 hypopharynx, 7 esophagus, 3 oropharynx, 2 oral cavity, 1 larynx, 1 paranasal sinus, 1 external auditory canal) with diffuse EGFR positivity were subjected to mutation analysis. Briefly, genome DNA from formalin-fixed paraffin embedded blocks were run through ASAN Panel, which addresses 74 somatic mutations including 38 point and 36 indel mutations for EGFR, KRAS, BRAF, and PIK3CA genes. Amplified PCR products in 8 separated multiplex fashion were treated with shrimp alkaline phosphatase, and followed by single base extension reaction using iPLEX-Pro kit from Sequenom with extension primers that hybridize immediately adjacent to the mutations. After incubation with resin for removing salt adductive, products were transferred to SpectroCHIPII for analysis using MALDI-ToF. Eight cases (35%) of BSCC were found to have substitution mutations or deletions in EGFR exon 18∼21, including both sensitive (L858R, del19) and resistant types (T790M) to EGFR-TKI. Two cases showed KRAS or PIK3CA point mutation. The results confirmed the mismatch between EGFR expression and mutation status in BSCC, and the presence of various mutations like NSCLC. Tailoring EGFR-TKI therapy for a subset of BSCC patients is in prospect.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 734. doi:1538-7445.AM2012-734
Abstract 740: PINCH is an independent prognostic factor in rectal cancer patients without preoperative radiotherapy: A study in a Swedish rectal cancer trial of preoperative radiotherapy
Authors: Holmqvist Annica Elisabet , Holmlund Birgitta , Ardsby Malin , Gao Jingfang , Adell Gunnar , Johansson Ann-Charlotte , Carstensen John , Langford Dianne , Sun Xiao-Feng
Published: August 2012

Background: Particularly interesting new cysteine-histidine rich protein (PINCH) connected to integrins of the cell surface, is involved in cell spreading, motility and proliferation. The expression of PINCH and its relationship to outcome have been studied, however, the clinical significance between PINCH and preoperative radiotherapy (RT) in tumors is unknown. In this study, PINCH expression and its relationship to RT, clinical, histological and biological factors were investigated in rectal cancer patients, and in colon cancer and fibroblast cell lines. Material and Methods: PINCH expression was immunohistochemically examined at the invasive margin and inner tumour area in 137 primary rectal adenocarcinomas (72 cases without RT and 65 cases with RT). PINCH expression in colon cancer (KM12C) and fibroblast (CCD18 Co) cell lines was examined by real time PCR. The KM12C and CCD 18 Co cell lines, cultured separately and co-cultured, were analyzed over time at 8h, 24h, 48h and 72h after radiation. Results: In patients without RT, strong PINCH expression at the invasive margin of tumors was related to worse survival, compared to patients with weak expression, independent of both TNM stage and differentiation (p = 0.03). No survival relationship in patients with RT was observed (p = 0.64). Real time PCR analyzes showed that KM12C irradiated cells tended to have a higher expression of PINCH at 24h compared to cells without radiation, while in co-cultured KM12C cells, PINCH tended to increase at 8h. PINCH seemed to increase at 8h in CCD 18 Co cells with radiation compared to cells without radiation, while in co-cultured CCD 18 Co cells, PINCH seemed to be lower at 8h in radiated cells than in non-radiated cells. Conclusions: PINCH expression at the invasive margin was an independent prognostic factor in patients without RT. RT might up-regulate the expression of PINCH, which may help us to select the best-suited patients for RT in the future. The levels of PINCH differ when separately cultured and co-cultured cells were compared, which might indicate that PINCH is involved in the crosstalk between tumor cells and their surrounding fibroblasts.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 740. doi:1538-7445.AM2012-740
Abstract 750: Impairment of clofarabine (CLO) clearance (CL) in the presence of cimetidine: Evidence of a drug-drug interaction between clofarabine and inhibitors of human organic cation transporter-2 (hOCT2)
Authors: Foster Matthew C. , Walko Christine , Kumar Parag , Huang Jeffrey , Ivanova Anastasia , Garcia Reynaldo , Deventer Hendrik Van , Ewesuedo Reginald , Shea Thomas C.
Published: August 2012

Background: CLO is a nucleoside analog with efficacy in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Preclinical studies using an isolated, perfused rat-kidney model suggested that CLO may be a substrate of OCT2, a channel that mediates the transport of cations across the renal tubular basolateral membrane. Evidence of this mechanism is lacking in humans, though this property could contribute to drug interactions with compounds such as cimetidine that inhibit hOCT2. Methods: Eligible patients were: 1) untreated AML ≤ 60 years of age unsuited for intensive induction therapies, 2) relapsed or refractory AML, or 3) MDS patients who failed ≤ 1 prior regimen. Patients were treated with CLO according to the schedule: CLO 15 mg/m2 IV day 1, CLO 30 mg/m2 PO day 3, CLO 15 mg/m2 IV day 5 preceded by two doses of oral cimetidine (800 mg PO 8-10 hours apart), and CLO 30 mg/m2 PO on days 6 and 7. Pharmacokinetic (PK) studies were obtained after CLO dosing on days 1, 3 and 5. CLO plasma concentration was determined, and concentration-time data was analyzed by non-compartmental methods. Oral bioavailability (F) was determined for each patient. The geometric means of area under the curve, 0-infinity (AUC), and CL for intravenous CLO administered after cimetidine doses were compared with AUC and CL for intravenous CLO administered without cimetidine. Results: To date, 8 patients have been treated. Mean F = 0.66, 90% confidence interval (CI) (0.49, 0.87). Comparisons of PK parameters between IV dosing with and without cimetidine are shown in the table. Conclusions: Co-administration of the hOCT2 inhibitor cimetidine with CLO appears to increase CLO AUC by impairing renal CL. Enrollment continues in an attempt to further support the putative mechanism of CLO renal clearance by hOCT2-mediated tubular secretion, and to further investigate the clinical import of this drug-drug interaction.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 750. doi:1538-7445.AM2012-750
Abstract 751: Mass balance, excretion and metabolism of [14C] ASA404 in cancer patients in a phase I trial
Authors: McKeage Mark , Fong Peter , Hong Kevin , Flarakos Jimmy , Mangold James , Du Yancy , Tanaka Chiaki , Schran Horst
Published: August 2012

Purpose: To determine the mass balance, excretion and metabolism of the small molecule flavonoid tumor vascular disrupting agent ASA404 in patients with advanced cancer. Methods: Seven cancer patients were given a single dose of 3000 mg [14C] ASA404 by intravenous infusion over 20 minutes prior to collection of samples of plasma, urine and faeces. Pharmacokinetic samples were analysed by HPLC, liquid scintillation counting, mass spectrometry, glusulase treatment and comparison to authentic standards. Descriptive pharmacokinetic parameters were generated by non-compartmental analysis. Results: Mass balance was achieved (mean recovery of radioactivity in excreta = 86.9% of the dose) with balanced excretion between urine (mean recovery of radioactivity in urine = 53.9% of dose) and faeces (mean recovery of radioactivity in faeces = 33.3% of dose). ASA404 was eliminated as parent drug, three known metabolites (6-hydroxy-ASA404, ASA404 acyl glucuronide and 6-hydroxy-ASA404 acyl glucuronide) and as two novel metabolites (an ASA404 dimer and an ASA404 dimer glucuronide conjugate). Unchanged ASA404 was the major radioactivity component detected in plasma within the first 24 hours after dosing. At later time-points, irreversibly protein bound ASA404 and all of the metabolites that had been detected in excreta, contributed to total plasma radioactivity. Conclusion: This study defined the substantial excretion of ASA404, mainly as metabolites, in both urine (over half of the dose) and faeces (about one third of the dose) after intravenous administration. Two novel metabolites were identified that were not reported by previous studies using nonradioactive techniques.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 751. doi:1538-7445.AM2012-751
Abstract 769: Restoration of c-Cbl function, by inhibiting Cdc42, confers tamoxifen sensitivity on basal-like (triple negative) breast cancer cells
Authors: Chen Hsing-Yu , Yang Yin , Noble Mark D.
Published: August 2012

Our present work offers a new means by which cancer cells become resistant to anti-cancer treatments and mechanism-driven approaches for overcoming such resistance. Specifically, here we demonstrate a previously unrecognized mechanism of tamoxifen (TMX) resistance distinct from loss of estrogen receptor on basal-like (triple negative) breast cancer cells, which are among the most challenging tumors to treat with current therapies. Our present finding emerged from trying to understand the puzzling differences in regulation of receptor tyrosine kinase (RTK) degradation in normal progenitor cells and in breast cancer cells. When glial progenitor cells become slightly more (15-20%) oxidized, such as by exposing them to TMX, we find sequential activation of Fyn (a member of the Src-family of kinases) and c-Cbl (an E3 ubiquitin ligase) is activated. Phosphorylation of c-Cbl causes ubiquitylation of its target proteins and thus increases the degradation of its target proteins, such as particular RTKs, including the epidermal growth factor receptor (EGFR, our specific target in this study). In contrast to normal progenitor cells, basal-like breast cancer cells exposed to TMX show increased Fyn activation but no increase in c-Cbl phosphorylation. We now have found that oxidation-induced activation of c-Cbl in basal-like breast cancer cells is inhibited due to expression of Cdc42. Cdc42 sequestered c-Cbl, prevented its activation and prevented EGFR from being degraded. Restoration of c-Cbl function, by genetically or pharmacologically inhibiting Cdc42 activation, reduced EGFR levels in these cells. More critically, restoring c-Cbl function sensitized these cells to TMX both in vitro and in vivo. Analysis of tumor growth in vivo showed that reducing the levels of Cdc42 both reduced the size of tumors and made them more sensitive to TMX. The results provide a novel defense mechanism that basal-like breast cancer cells utilize to prevent EGFR degradation which may have high relevance to treatment of these tumors. Of particular importance is the ability of Cdc42 knockdown to confer TMX sensitivity on these otherwise resistant tumor cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 769. doi:1538-7445.AM2012-769
Abstract 770: Overcoming Trastuzumab resistance with the novel pan-erbb inhibitor AZD8931
Authors: Balachandran Banujan , Chabot Catherine , Hamel Sophie , Chan Carmel T. , Kane Susan , Buchanan Marguerite , Aguilar-Mahecha Adriana , Basik Mark
Published: August 2012

Approximately 15-20% of all invasive breast carcinomas overexpress the HER-2 receptor, a membrane surface-bound receptor tyrosine kinase upstream of critical proliferation and cell survival pathways. Trastuzumab, a humanized monoclonal antibody to the extracellular domain of HER-2, has proven to be a beneficial treatment for patients diagnosed as HER-2+, but does have its limitations. A majority of advanced HER-2 positive breast cancer patients will develop resistance to the therapy within the first year while many others do not respond to the drug when used alone. The purpose of this study was to determine whether AZD8931, a reversible pan-ERBB inhibitor that equipotently inhibits the tyrosine kinase-activity of EGFR, HER-2, and HER-3, could reverse this resistance in established trastuzumab-resistant BT474 and SKBR3 cell lines. To account for tumor heterogeneity in HER-2+ tumors, response to AZD8931 was examined in both ER-positive (BT474) and ER-negative (SKBR3) cell lines. Proliferation assays were used to assess the efficacy of AZD8931 alone and in combination with trastuzumab. Results showed significantly diminished cell growth in all tested cell lines, including those resistant to trastuzumab, at clinically relevant concentrations of AZD8931 (<2µM). Furthermore, when AZD8931 was tested in conjunction with trastuzumab, the resistance to trastuzumab was reversed using clinically relevant doses of trastuzumab. Using combination indices, it was found that AZD8931 synergizes well with trastuzumab and could be used as a combination therapy for both trastuzumab-sensitive and trastuzumab-resistant breast cancer patients. Western blot analyses confirmed the results of cell proliferation assays as p-EGFR, p-HER-2, p-HER-3, p-Akt, and p-MAPK, were all reduced after treatment with AZD8931. Thus, AZD8931 alone or in combination with trastuzumab may be an effective therapy in HER2+ breast cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 770. doi:1538-7445.AM2012-770
Abstract 772: Notch1 affects ABCC1-mediated drug efflux and drug sensitivity in MCF7 breast cancer cells
Authors: Lu Meiling , Majumdar Neena , Jiang Ruixuan , Cho Sungpil , Beck William T.
Published: August 2012

Development of multidrug resistance is a major impediment to the successful treatment of cancer. Although many cellular mechanisms are involved in multidrug resistant cancers, overexpression of ATP-binding cassette (ABC) membrane transporters represents one of the main determinants of the multidrug resistance phenotype. We have previously demonstrated a positive correlation of expression of intracellular Notch1 (NIC) and the ABCC1 transporter; we found that NIC contributes to multidrug resistance by upregulation of ABCC1 (S Cho, M Lu et al, PNAS, in press, 2011). In order to determine whether there is a functional relationship between the two proteins, we performed drug efflux experiments. We treated drug-sensitive MCF-7 and multidrug resistant (MDR) MCF-7/VP breast cancer cells with the anticancer drug doxorubicin and measured the amount of drug efflux by flow cytometry over time. The MDR MCF-7/VP cells, which have high levels of activated Notch1 and ABCC1 proteins, exhibited increased doxorubicin efflux, compared to the drug-sensitive MCF-7 cells. Since γ-secretase (GS) is required for the processing of Notch into its active form, NIC, we blocked GS activity using a GS inhibitor, DAPT, in MCF-7/VP cells and assayed drug efflux from them. We found that inhibition of Notch signaling by DAPT blocks ABCC1 mediated drug efflux. To better understand the connection between Notch, ABCC1, and drug efflux, we compared drug efflux in MCF-7 cells stably overexpressing NIC (ICN1-c4, which also overexpress ABCC1), and the “empty vector” control MCF-7 cells (pcDNA3). As expected, we saw increased drug efflux in the ICN1-c4 cells compared to MCF7/pcDNA3 cells. To establish whether the observed drug efflux is ABCC1-specific, we treated ICN1-c4 cells with either the ABCC1-specific inhibitors reversan or probenecid, or with an ABCC1 siRNA to knockdown ABCC1 expression, and then examined these cells for changes in drug efflux. We found that inhibition of ABCC1, by reducing ABCC1 activity or levels in the presence of activated Notch1, blocks drug efflux from ICN1-c4 cells. In addition, we also found that the ABCC1 inhibitor reversan sensitizes ICN1-c4 cells to doxorubicin, and knockdown of ABCC1 reverses the resistance of ICN1-c4 cells to doxorubicin. These results strongly support the idea that Notch1 exerts its effect on ABCC1-mediated drug efflux to a large extent through its induction of ABCC1. Overall, our results reveal a novel functional relationship between expression of Notch and ABCC1. (Supported in part by CA40570 [to WTB] and in part by UIC.)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 772. doi:1538-7445.AM2012-772
Abstract 773: Crizotinib (PF-02341066) reverses multidrug resistance in cancer cells by inhibiting the function of P-glycoprotein
Authors: Zhou Wen-jing , Wang Fang , Zhang Xu , To Kenneth Kin Wah , Huang Hong-bing , Fu Li-Wu
Published: August 2012

Background and purpose: Besides targeting the well-known oncogenic c-Met, crizotinib is the first oral tyrosine kinase inhibitor (TKI) inhibiting anaplastic lymphoma kinase (ALK) in clinical trials for the treatment of non-small cell lung cancer (NSCLC). In this study, we investigated the potential multidrug resistance (MDR) reversal by crizotinib in vitro and in vivo. Experimental approach: MTT methods were used in vitro and the xenografts in nude mice were used in vivo to investigate crizotinib reversal of MDR. To understand the mechanisms for MDR reversal, the alterations of intracellular doxorubicin(Dox) or rhodamine 123 accumulation, Dox effluxion, ABCB1 expression level, ATPase activity of ABCB1, and crizotinib-induced c-Met, Akt and Erk1/2 phosphorylation were examined. Key results: Crizotinib significantly enhanced the cytotoxicity of ABCB1 substrate chemotherapeutic agents in MDR cells, with no effect found on sensitive cells in vitro and in vivo. In addition, crizotinib significantly increased the intracellular accumulation of rhodamine 123 and doxorubicin and inhibited the drug efflux in ABCB1-overexpressing MDR cells. Further studies showed that crizotinib enhanced the ATPase activity of ABCB1 in concentration-dependent manner. However, the expressions of ABCB1 were not affected and the reversal activity of crizotinib was not related to the phosphorylation of c-Met, Akt or Erk1/2. Importantly, crizotinib significantly enhanced the effect of paclitaxel against the KBv200 cell xenografts in nude mice. Conclusions and implications: Crizotinib was found to reverse ABCB1-mediated MDR by inhibiting ABCB1 transport function without involvement of ABCB1 expression or blockade of the Akt or Erk1/2 pathways. These findings is useful for combination chemotherapy of crizotinib with conventional chemotherapeutic drugs.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 773. doi:1538-7445.AM2012-773
Abstract 779: Prodrug-mediated reversal of multidrug resistance in breast cancer cells
Authors: Ajaj Khalid Abu , Lee Yeonju , Graser Ralph , Kratz Felix
Published: August 2012

The P-glycoprotein (P-gp) is a 170 kDa protein that acts as an energy-dependent, transmembrane efflux pump and is encoded by the MDR1 gene. It has been shown to be responsible for multidrug resistance (MDR) in a defined subpopulation of breast cancer patients and thus represents a molecular target for circumventing MDR in this tumor indication. Third generation MDR modulators have been developed that demonstrated high selectivity for P-gp with inhibitory activities in the low nanomolar range. Although some objective responses were achieved in clinical trials, combination therapy with these MDR-modulators caused unacceptable toxicity. Targeting P-gp inhibitors to the tumor site is a means to increase their therapeutic index, and in this context binding tailor-made prodrugs to circulating albumin is an established technology to reduce the toxicity and enhance the efficacy of anticancer drugs. In this work we consequently developed an acid-sensitive albumin-binding prodrug of the P-gp inhibitor zosuquidar (LY335979) in a two-step synthesis using a maleimide hydrazone linker system established in our laboratory that first introduces acetylbenzoic acid at the OH-group of zosuquidar followed by derivatization with 6-maleimidocaproyl hydrazide to form the acid-sensitive hydrazone bond. The maleimide group enables the prodrug to bind rapidly and selectively to the cysteine-34 position of endogenous albumin after intravenous administration. HPLC analysis demonstrated rapid albumin binding of the zosuquidar prodrug as well as the quantitative release of the acetylbenzoic ester derivative of zosuquidar at pH 5.0. Subsequently, its ability to circumvent MDR was tested in two doxorubicin-resistant breast carcinoma cell lines (MCF-7/ADR and MT-3/ADR). The MDR status of these cell lines can be reversed by zosuquidar which was confirmed in a rhodamine 123 assay using fluorescence microscopy and FACS analysis. Furthermore, zosuquidar as well its acid-sensitive albumin conjugate re-sensitized cells to doxorubicin as well to an albumin-binding prodrug of doxorubicin, i.e. the 6-maleimidocaproyl hydrazone derivative of doxorubicin, achieving IC50 values in the same order of magnitude as the parental cell lines. Thus a novel formulation of zosuquidar has been developed that may be used to improve the toxicity issues and tumor targeting properties of the original compound.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 779. doi:1538-7445.AM2012-779
Abstract 784A: Profiling pancreatic cancer metabolism and tumor microenvironment for therapy
Authors: Bose Sminu , Tsukamoto Takashi , Slusher Barbara , Royer Robert E. , Jagt David L. Vander , Le Anne
Published: August 2012

Pancreatic cancers have one of the highest fatality rates among all cancers and their response to therapies is highly variable. We have recently shown that inhibition of lactate dehydrogenase A (LDHA) and glutaminase (GLS) through small drug-like molecules causes pancreatic tumor regression. These studies indicate that targeting the metabolic reprogramming of cancer cells is a promising new approach to pancreatic cancer therapy. In order to translate these metabolic inhibitors to the clinic, our goal is to characterize and enable targeted selection of patients based on predicted metabolic response. Although genetic mutations may ultimately be the prime causes of early stage cancer, they can also lead to changes in cancer metabolism which enable cancer cells to proliferate and survive even under the hypoxic and nutrient-deprived conditions often encountered in the tumor microenvironment. The biochemical changes in cancer cells, which determine their behavior in terms of growth, survival and mobility, represent a functional readout of responses to external agents. We hypothesize that the metabolites of tumors that are sensitive to metabolic inhibitors are measurably different from those of resistant ones. We can therefore propose these metabolites as potential functional predictors of response. The proposed research will also study the metabolic reprogramming of cancer cells in the tumor microenvironment that can affect pancreatic cancer sensitivity to LDHA and GLS inhibition. The proposed experiments will use Metabolomics technology to trace the metabolic prototypes of pancreatic orthotopic xenografts to identify the metabolic signature of FX11 or BPTES-sensitive tumors as compared to resistant ones. For an analysis of the effects due to the tumor hypoxic microenvironment, we will use our innovative tool, the HypoxCR reporter system, which can simultaneously detect hypoxic cells and proliferating cells to define the effects of the pancreatic cancer tumor microenvironment on their sensitivity to metabolic inhibitors. This will be the first evaluation of the hypoxic tumor microenvironment in regards to how it affects the response of subfractions of pancreatic orthotopic xenograft tumor cells to metabolic inhibitors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 784A. doi:1538-7445.AM2012-784A
Abstract 789: GSTP1 expression is regulated by MycN and is a marker of poor outcome in childhood neuroblastoma
Authors: Norris Murray D. , Fletcher Jamie I. , Gherardi Samuele , Murray Jayne , Burkhart Catherine , Russell Amanda , Valli Emanuele , Oberthuer Andre , Ashton Lesley J. , London Wendy B. , Marshall Glenn M. , Perini Giovanni , Haber Michelle
Published: August 2012

In childhood neuroblastoma, amplification of the transcription factor MycN is associated with poor outcome and a multidrug resistant phenotype. We have previously shown that MycN regulates the expression of several ATP-binding cassette (ABC) transporter genes, and that these genes represent powerful prognostic markers in neuroblastoma (1,2,3). Although these transporters are able to efflux a wide range of cytotoxic drugs, they do not confer resistance to several important cytotoxic agents used to treat neuroblastoma, including cisplatin and cyclophosphamide, hence we explored the prognostic significance and transcriptional regulation of the phase II detoxifying enzyme, glutathione S-transferase P1 (GSTP1). Using quantitative real-time PCR, GSTP1 gene expression was assessed in a retrospective cohort of 51 patients, and subsequently in a cohort of 207 prospectively accrued primary neuroblastomas. These data, and GSTP1 expression data from an independent microarray study of 251 neuroblastoma samples, were correlated with established prognostic indicators and disease outcome. High levels of GSTP1 were associated with decreased event-free and overall survival in all three cohorts. Multivariate analyses, including age at diagnosis, tumor stage and MYCN amplification status, were conducted on the two larger cohorts and demonstrated independent prognostic significance of GSTP1 expression levels. We also explored the regulation of GSTP1 by MycN using chromatin immunoprecipitation (ChIP) and luciferase reporter assays in neuroblastoma cell lines and found that GSTP1 is a direct transcriptional target of MycN. We conclude that N-Myc regulates multiple components of drug metabolism and efflux pathways, including GSTP1 and transporters of the ABC superfamily. The regulation of these key multidrug resistance mechanisms may have particular significance for malignancies with amplification of Myc family genes. 1) J Biol Chem, 285:19532-19543, 2010 2) J Natl Cancer Institute, 103:1236-51, 2011 4) Nat Rev Cancer, 10:147-156, 2010

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 789. doi:1538-7445.AM2012-789
Abstract 795: Epigenetics, cell cycle and drug-resistant ovarian cancer
Authors: Safuwan Nur Arnida Mohammed , Chivers Pritlata , Crook Tim , Syed Nelofer , Coley Helen M.
Published: August 2012

Epithelial ovarian cancer (EOC) is the most lethal of the gynaecological malignancies and currently stage III/IV disease is associated with a 25% 5 year survival rate. A major factor associated with advanced EOC is the development of drug resistant disease, characterised by a lack of response to platinum and taxane based agents. In an effort to clarify mechanisms underlying chemorefractory EOC we have developed a number of drug resistant cancer cell lines. DNA microarray screening of drug resistant versus drug sensitive cell lines (combining a methylation reversal step using demethylating agents) indicated down-regulation of a number of genes with evidence of epigenetic silencing by promoter methylation in many cases. We have identified P57kip2 a cyclin dependent kinase inhibitor (CDKi) as a gene that is subjected to methylation in carboplatin-resistance, as shown in the PEO1CarbR line. Using a siRNA approach, silencing of the p57kip2 gene in drug sensitive parental PEO1 or SKOV-3 cells gave rise to a reduced sensitivity to platinum agents i.e. cisplatin or carboplatin as assessed using apoptosis with the annexinV assay and flow cytometry. Using chemosensitivity testing (MTT) of PEO1 parental and PEO1CarbR lines versus seliciclib (a CDK2 inhibitory drug) we saw an association with sensitivity to this agent with down-regulation of p57kip2. The IC50 values obtained for the human ovarian cancer cell line PEO1 and PEO1CarboR were 27.4 and 19.2μM, respectively (p = <0.05). Cell cycle analysis of seliciclib treated cells indicated a prolonged S-phase as a marker of increased sensitivity to the drug and an increased apoptotic response in p57kip2 silenced cells. Our data suggest that CDK inhibitors such as seliciclib may have utility in tumours that show downregulation of the endogenous CDKi p57kip2 and identification of such patients may indicate a sub-group that respond preferentially to seliciclib. The same screening platform also enabled us to identify wee1 and stratifin (14-3-3α) as genes significantly downregulated in taxane-resistant cell lines. The 2 gene products are important in maintaining genomic stability alongside other proteins such as Chk1 and ATR. Wee1 controls G2M by keeping CDK2/Cyclin B inactive whilst binding of 14-3-3 isoforms enhances its activity. Demethylation treatment using 5′aza-cytidine and Trichostatin A unmasked gene expression, indicating that these genes are hypermethylated in taxane-resistant cell line. Current work aims to confirm further the role of these 2 genes in drug resistance by a series of knock-in and knock-out experiments.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 795. doi:1538-7445.AM2012-795