Human papillomavirus status and gene expression profiles of oropharyngeal and oral cancers from European American and African American patients

BACKGROUND

Disparities in prevalence, human papillomavirus (HPV) status, and mortality rates for head and neck cancer have been described between African American and European American patients.

METHODS

We studied the HPV status and gene expression profiles in 56 oropharyngeal/oral cavity tumors and 9 normal tissue samples from European American and African American patients treated in South Carolina between 2010 and 2012.

RESULTS

Overall, 59% of tumors were HPV DNA-positive, but only 48% of those expressed E7 mRNA (HPV-active). The prevalence of HPV-active tumors was 10% in African American patients and 39% in European American patients. Tumors positive for HPV DNA but negative for HPV mRNA exhibited gene expression profiles distinct from those of both HPV-active and HPV-negative cancers, suggesting that HPV DNA-positive/RNA-negative tumors may constitute a unique group.

CONCLUSION

This study provides a direct assessment of differential expression patterns in HPV-related oropharyngeal cancer arising from African American and European American patients, for which there is a paucity of data. © 2015 Wiley Periodicals, Inc. Head Neck 00: 000-000, 2015.

Protein Phosphatase 2A Inhibition with LB100 Enhances Radiation-Induced Mitotic Catastrophe and Tumor Growth Delay in Glioblastoma

Protein phosphatase 2A (PP2A) is a tumor suppressor whose function is lost in many cancers. An emerging, though counterintuitive, therapeutic approach is inhibition of PP2A to drive damaged cells through the cell cycle, sensitizing them to radiotherapy. We investigated the effects of PP2A inhibition on U251 glioblastoma cells following radiation treatment in vitro and in a xenograft mouse model in vivo. Radiotherapy alone augmented PP2A activity, though this was significantly attenuated with combination LB100 treatment. LB100 treatment yielded a radiation dose enhancement factor of 1.45 and increased the rate of postradiation mitotic catastrophe at 72 and 96 hours. Glioblastoma cells treated with combination LB100 and radiotherapy maintained increased γ-H2AX expression at 24 hours, diminishing cellular repair of radiation-induced DNA double-strand breaks. Combination therapy significantly enhanced tumor growth delay and mouse survival and decreased p53 expression 3.68-fold, compared with radiotherapy alone. LB100 treatment effectively inhibited PP2A activity and enhanced U251 glioblastoma radiosensitivity in vitro and in vivo. Combination treatment with LB100 and radiation significantly delayed tumor growth, prolonging survival. The mechanism of radiosensitization appears to be related to increased mitotic catastrophe, decreased capacity for repair of DNA double-strand breaks, and diminished p53 DNA-damage response pathway activity.

Neuroendocrine Merkel cell carcinoma is associated with mutations in key DNA repair, epigenetic and apoptosis pathways: a case-based study using targeted massively parallel sequencing

INTRODUCTION

Merkel cell carcinoma (MCC) is a rare neuroendocrine carcinoma with a poorly understood molecular etiology. We implemented a comprehensive deep sequencing approach to identify mutations in the tumor DNA from a cohort of patients treated at our institution over the past 15 years. Our results indicate mutations that may constitute therapeutic targets in MCC.

METHODS

Five patients were treated for MCC within the study interval. Patients with adequate tissue (n = 4), positive neuroendocrine differentiation (chromogranin, synaptophysin, and cytokeratin 20), and histopathological confirmation of MCC were included in the study. DNA was extracted from archival tumor tissue samples and analyzed by massively parallel sequencing using a targeted, multiplex PCR approach followed by semiconductor sequencing.

RESULTS

We demonstrate high-penetrance nonsense mutations in PDE4DIP (n = 4) as well as various missense mutations in the DNA damage response (PRKDC, AURKB, ERCC5, ATR, and ATRX) and epigenetic modulating enzymes (MLL3).

CONCLUSION

We describe several mutations in potential disease-relevant genes and pathways. These targets should be evaluated in a larger cohort to determine their role in the molecular pathogenesis of MCC.

The translational significance of epithelial-mesenchymal transition in head and neck cancer

Positive markers of epithelial-mesenchymal transition (EMT) in head and neck cancers complicate clinical management and are associated with reduced survival. We discuss recent translational discoveries in EMT and suggest additional actionable molecular pathways, biomarkers, and clinical agents.

Abstract 450: Head and neck cancer and HPV infection: A potential role for peritumoral neurogenesis in HPV-associated malignancy

Background: Head and neck cancers account for 5% of all cancer related deaths and present with complex molecular pathology and clinical features owing to their functional anatomical location. The molecular etiology of head and neck squamous cancer (HNSC) has gained extensive attention recently revealing key mutations, viral infection, and an emerging landscape of varying disease sub-types. While perineural invasion has long been associated with poor outcome in HNSC, the association of neurogenesis-related genes with cancer progression has only recently come into focus in HNSC. Using prospectively acquired patient samples and TCGA HNSC mutational analyses we further characterized the sequelae of molecular changes in neurogenesis-related genes and propose that these genes play a significant role in HNSC development.

Methods: All clinical specimens were collected under approval by Institutional Review Board. Prospectively collected samples were analyzed for HPV DNA by linear arrays (InnoLipa) and q-PCR for E7-RNA. Gene expression arrays were conducted to determine differences in HPV activity and neuronal associated gene ontologies (Agilent). Gene expression profiles were compared in oral HPV+ and HPV- cultured oral keratinocytes as well as the TCGA Kandoth & Tang datasets. Gene targets were validated by Immunohistochemistry and qPCR.

Results: Initial unsupervised hierarchical clustering analysis of our HNSC cohort revealed a separation of HPV+ HPV+E7-(HPV-inactive: HPVin), and HPV- tumors with changes in the expression of key neurogenesis-related genes. For example, POU4F1, NGFR, and GRIN2C were significantly up-regulated (P<0.05) in HPV+ vs HPVin cancers. Additional analysis of TCGA data revealed divergence of the mutational spectra in HNSC with and without perineural invasion.

Conclusion: Our preliminary findings indicate the emerging importance of neurogenesis-related genes and perineural involvement in HNSC and support a divergence of HPV+, HPVin, and HPV- HNSC sub-types.

Citation Format: Christian A. Graves, Swati Tomar, Diego Altomare, James R. Wells, Kim E. Creek, Lucia Pirisi. Head and neck cancer and HPV infection: A potential role for peritumoral neurogenesis in HPV-associated malignancy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 450. doi:10.1158/1538-7445.AM2014-450

Sonoablation and application of MRI guided focused ultrasound in a preclinical model

Stereotaxic sonoablative surgery by MRI guided high intensity focused ultrasound (FUS) holds great potential in disorders of the central nervous system (CNS). We previously described the ExAblate 2000 system (InSightec, Tirat Carmel, Israel), currently in use for various pathologies including uterine, liver, and, breast tumors, and referred to as the "body" system. Using a porcine model we have previously demonstrated, using the body system, the ablative capacity and thermal transfer in the cortex; developed a reproducible and translational model of craniectomy and post-operative recovery in FUS; and determined a grouping strategy based on thermal ablation and pathologic incremental changes in the cortex. Here we describe a novel ExAblate 4000 system that is designed specifically to treat CNS disorders ("head" system). Twenty-two swine underwent an improved wide craniectomy for positioning of the ExAblate 4000 containing 1024 elements arrayed with MRI guidance. Further neurologic and pathological analysis was performed 1 week post-operatively. Subjects underwent a wide craniectomy followed by high intensity MR guided focused ultrasound (MRgHIFU) sonoablation. Thermal ultrasonic ablative lesions were achieved in all subjects (n=22) ranging from 52-65°C following ∼70 consecutive sonications at 80 watts. These subjects were grouped based on thermal ablative lesions and post-operative staging (MRI, gross and microscopic pathology). Our results indicate the reproducibility of a porcine model for cerebral ablation, achieved across a dynamic temperature range, and well tolerated in this cohort. The ExAblate 4000 system is efficient through a wide craniectomy as well as a closed skull and demonstrates a high safety margin. Incremental hemorrhage and necrosis were minimal and energy dependent, indicating MRgHIFU can be used for the treatment of various cerebral pathologies and movement disorders.

Brain biopsy in AIDS patients: diagnostic yield and treatment applications

Objective

Central nervous system involvement in AIDS patients can present at any stage of the disease. Brain lesions detected in imaging studies are usually treated empirically. A brain biopsy is indicated in the absence of clinical and radiologic improvement. In the present study, 16 AIDS patients underwent brain biopsy. We evaluated the diagnostic yield of the brain biopsy and the changes in the disease course.

Materials and methods

Sixteen consecutive AIDS patients (12 men, 4 women; mean age 40.8 years) underwent a brain biopsy at Sheba Medical Center between 1997 and 2009. A retrospective analysis was performed and the clinical outcome was recorded.

Results

Median CD4 count before biopsy was 62.6. Magnetic resonance images revealed multiple lesions in 12 patients and enhancing lesions in 12 patients. A total of 19 biopsies were performed in 16 patients. In the present series, the initial procedures provided a diagnostic yield of 81.25% (13 diagnostic cases from 16 procedures in 16 patients). Two of these patients underwent repeated biopsies that were eventually diagnostic . If repeated biopsies were taken into consideration, the diagnostic yield was 93.75% (15 diagnostic cases in 16 patients). The rate of hemorrhagic complications was 10.5% (2 hemorrhages in 19 procedures).

Pathologic examination revealed parasitic and fungal infections in 6 patients (6/16; 38%), progressive multifocal leukoencephalopathy in 4 patients (4/16; 25%), AIDS encephalopathy in 4 patients (4/16; 25%), and lymphoma in 1 patient (1/16; 6%). One patient had a nonspecific inflammatory process (6%). The treatment modality was modified in 12 patients and led to clinical and radiologic improvement in 8 patients.

Conclusions

Brain biopsy should be considered when empiric treatment of central nervous system lesions in AIDS patients fails. Biopsy is diagnostic in the majority of patients. The diagnosis allows for treatment modifications, which lead to clinical and radiologic improvement in some patients.

The relationship of vascular endothelial growth factor gene polymorphisms and clinical outcome in advanced gastric cancer patients treated with FOLFOX: VEGF polymorphism in gastric cancer

Background

The aim of this study is to evaluate the associations between vascular endothelial growth factor (VEGF) Single-nucleotide polymorphisms (SNPs) and clinical outcome in advanced gastric cancer patients treated with oxaliplatin, 5-fluorouracil, and leucovorin (FOLFOX).

Methods

Genomic DNA was isolated from whole blood, and six VEGF (−2578C/A, -2489C/T, -1498 T/C, -634 G/C, +936C/T, and +1612 G/A) gene polymorphisms were analyzed by PCR. Levels of serum VEGF were measured using enzyme-linked immunoassays.

Results

Patients with G/G genotype for VEGF -634 G/C gene polymorphism showed a lower response rate (22.2%) than those with G/C or C/C genotype (32.3%, 51.1%; P = 0.034). Patients with the VEGF -634 G/C polymorphism G/C + C/C genotype had a longer progression free survival (PFS) of 4.9 months, compared with the PFS of 3.5 months for those with the G/G (P = 0.043, log-rank test). By multivariate analysis, this G/G genotype of VEGF -634 G/C polymorphism was identified as an independent prognostic factor (Hazard ratio 1.497, P = 0.017).

Conclusion

Our data suggest that G/G genotype of VEGF -634 G/C polymorphism is related to the higher serum levels of VEGF, and poor clinical outcome in advanced gastric cancer patients.

Prognostic significance of serum levels of vascular endothelial growth factor and insulin-like growth factor-1 in advanced gastric cancer patients treated with FOLFOX chemotherapy

BACKGROUND

Tumor vascular endothelial growth factor (VEGF) is a key angiogenic factor and may have an impact on tumor progression and response to chemotherapy. The insulin-like growth factor (IGF) system is related to cell proliferation and tumor growth. However, there is limited available data regarding the clinical and prognostic significance of VEGF or IGF-1 in advanced gastric cancer. The aim of this study was to evaluate the prognostic significance of serum VEGF and IGF-1 levels in advanced gastric cancer patients who were treated with oxaliplatin/5-fluorouracil (FOLFOX).

METHODS

The study population consisted of 100 advanced gastric cancer patients (median age 56 years). Patients were treated with oxaliplatin 85 mg/m(2) as a 2-hour infusion on day 1 plus leucovorin 20 mg/m(2) over 10 min, followed by a 5-fluorouracil (5-FU) bolus 400 mg/m(2) and 22 h of continuous infusion of 600 mg/m(2) on days 1-2. Treatment was repeated in 2-week intervals. The levels of serum VEGF and IGF-1 were measured using enzyme-linked immunoassays.

RESULTS

There was a significant correlation between the serum level of VEGF and Lauren's classification (p = 0.030) and previous operations (p = 0.010). IGF-1 was associated with the number of metastases (p = 0.012). The median level of serum VEGF was decreased after FOLFOX chemotherapy (p = 0.034). However, none of the measured serum markers were significantly correlated with response. In univariate analysis, overall survival (p < 0.001) was significantly shorter in patients with high serum levels of VEGF. Multivariate analysis revealed that VEGF was an independent factor for overall survival (HR 2.221; 95% CI 1.377-3.583, p = 0.001). Furthermore, IGF-1 had no significant influence on the clinical outcome.

CONCLUSION

A high level of serum VEGF is an independent prognostic factor in patients with advanced gastric cancer treated with chemotherapy. This may help to identify the patients who are more sensitive to the FOLFOX regimen.

Abstract 4539: Vascular endothelial growth factor gene polymorphisms and clinical outcome in advanced gastric cancer treated with FOLFOX

Background: Single-nucleotide polymorphisms (SNPs) of the vascular endothelial growth factor (VEGF) gene may have an impact on tumor progression, and response to chemotherapy. The aim of this study is to evaluate the associations between VEGF SNPs and clinical outcome in advanced gastric cancer patients treated with oxaliplatin, 5-fluorouracil, and leucovorin (FOLFOX). Methods: One hundred ninety recurrent or metastatic gastric cancer patients were enrolled in this study and treated with FOLFOX regimen. Genomic DNA was isolated from whole blood, and six VEGF (-2578C/A, –2489C/T, –1498T/C, –634G/C, 936C/T, and 1612G/A) gene polymorphisms were analyzed by PCR. Results: Patients genotyped G/G for –634G/C gene polymorphism had lower response rate (22.2%) than those G/C or C/C (32.3%, 51.1%; p = 0.034). The median serum levels of VEGF was higher in G/G genotypes than G/C + C/C (724.1 pg/ml vs. 462.4 pg/ml, p = 0.041). Patients with the VEGF –634CG/C polymorphism G/C + C/C genotype had a longer time to progression (TTP) of 4.9 months, compared with the TTP of 3.5 months for those with the G/G (p = 0.012, log-rank test). By multivariate analysis, this G/G genotype of –634G/C polymorphism was identified as an independent prognostic factor (Hazard ratio 1.497, p = 0.017). No significant influence on overall survival (OS) was observed by the –634 G/C. However, other SNPs were not related to response rate, TTP, or OS. Conclusion: Our data suggest that G/G genotype of –634G/C polymorphism is related to the higher serum levels of VEGF, and poor clinical outcome in advanced gastric cancer patients. It may help to identify patients who are more sensitive to FOLFOX regimen.

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 4539. doi:1538-7445.AM2012-4539

Pathways of angiogenic resistance in glioblastoma: Adaptations in growth factor signaling in response to VEGF and HGF attenuation

Background: Glioblastoma is the most common and lethal central nervous system malignancy with a median survival often less than 18 months. Despite promising initial responses to anti-angiogenic therapies many patients with this disease develop resistance to treatment via poorly understood mechanisms. Here we demonstrate that glioblastoma cell lines grown under growth factor antagonizing conditions exhibit an altered phenotype with changes in growth factor signaling, gene expression as well as in vivo tumorigenesis.

Methods: U87 cells were cultured under constant pressure with bevacizumab (3.0 mg/mL), AMG102 (1.0 µg/mL), or a combination of both drugs long term (seven or more passages) in adherent culture. In vitro expression analysis was carried out by growth factor and receptor tyrosine kinase arrays, cDNA microarray, and ELISA. Intracranial xenograft studies demonstrated resultant differences in growth kinetics and survival.

Results: Hepatocyte growth factor (HGF), glial derived neurotrophic factor (GDNF), and platelet-derived growth factor AA (PDGFAA) were elevated at 5.3, 4.5, and 3.9 fold in combinatorially treated cells versus controls, respectively. These changes correlated with relative increases in corresponding receptor mRNA and protein expression. Furthermore, AMG102 and combinatorially pressured cells were highly tumorigenic as compared to control and bevacizumab treated cells in vivo (Median survival 10 ± 1 vs. 32 ± 2 days, respectively).

Conclusion: Herein we describe concomitant increases of various oncogenic growth factors which might potentiate tumor survival and therapeutic resistance. These results suggest several potential molecular bypass mechanisms facing proposed angiogenic strategies. Evaluation of resistant phenotypes provides insight on the adaptive complexity of glioblastoma and offers potential for targeting recurrent disease.

Classical conditioning of the nictitating membrane response in aged rabbits

There was no difference between old and young animals in acquisition of the conditioned response in the delay conditioning paradigm, nor were there any age-related differences in generalization to the tone CS or in sensitivity to the tone CS or eye shock UCS. In the trace conditioning paradigm, however, old animals acquired the conditioned response significantly slower than young animals. Because the same stimulus parameters and the same responses were used in both paradigms, it is unlikely that the age-related differences in trace conditioning were due to differences in stimulus sensitivity, motor deficits, motivation, or fatigue. Rather, the differences appear due to associative factors. The increased demands of the trace paradigm, which includes a within trial memory component, may be a critical factor in the age related disruption. Moreover, recent data suggest that trace and delay conditioning may involve different neuronal systems (e.g., hippocampus appears necessary for trace but not delay conditioning) and these systems may be differentially effected by the aging process.

Age-related disruption of trace but not delay classical conditioning of the rabbit's nictitating membrane response

Young (6 months of age) and old (36-60 months) New Zealand albino rabbits underwent classical conditioning of the nictitating membrane response in either a delay conditioning (Experiment 1) or a trace conditioning (Experiment 2) paradigm. There was no difference between old and young animals in acquisition of the conditioned response in the delay paradigm, nor were there any age-related differences in generalization to the tone conditioned stimulus (CS) or in sensitivity to the tone CS or eye shock unconditioned stimulus. In the trace conditioning paradigm, however, old animals acquired the conditioned response significantly more slowly than young rabbits. Because the same stimulus parameters and the same response were used in both experiments, it is unlikely that age-related differences in trace conditioning were due to stimulus sensitivity, motivation, or fatigue. The results are discussed in terms of how brain changes that accompany aging could differentially affect these two types of classical conditioning.

Age-related disruption of trace but not delay classical conditioning of the rabbit's nictitating membrane response

Young (6 months of age) and old (36-60 months) New Zealand albino rabbits underwent classical conditioning of the nictitating membrane response in either a delay conditioning (Experiment 1) or a trace conditioning (Experiment 2) paradigm. There was no difference between old and young animals in acquisition of the conditioned response in the delay paradigm, nor were there any age-related differences in generalization to the tone conditioned stimulus (CS) or in sensitivity to the tone CS or eye shock unconditioned stimulus. In the trace conditioning paradigm, however, old animals acquired the conditioned response significantly more slowly than young rabbits. Because the same stimulus parameters and the same response were used in both experiments, it is unlikely that age-related differences in trace conditioning were due to stimulus sensitivity, motivation, or fatigue. The results are discussed in terms of how brain changes that accompany aging could differentially affect these two types of classical conditioning.