Kara Hamilton

2-Deoxy-d-glucose Increases the Efficacy of Adriamycin and Paclitaxel in Human Osteosarcoma and Non-Small Cell Lung Cancers In Vivo

Slow-growing cell populations located within solid tumors are difficult to target selectively because most cells in normal tissues also have low replication rates. However, a distinguishing feature between slow-growing normal and tumor cells is the hypoxic microenvironment of the latter, which makes them extraordinarily dependent on anaerobic glycolysis for survival. Previously, we have shown that hypoxic tumor cells exhibit increased sensitivity to inhibitors of glycolysis in three distinct in vitro models. Based on these results, we predicted that combination therapy of a chemotherapeutic agent to target rapidly dividing cells and a glycolytic inhibitor to target slow-growing tumor cells would have better efficacy than either agent alone. Here, we test this strategy in vivo using the glycolytic inhibitor 2-deoxy-d-glucose (2-DG) in combination with Adriamycin (ADR) or paclitaxel in nude mouse xenograft models of human osteosarcoma and non-small cell lung cancer. Nude mice implanted with osteosarcoma cells were divided into four groups as follows: (a) untreated controls; (b) mice treated with ADR alone; (c) mice treated with 2-DG alone; or (d) mice treated with a combination of ADR + 2-DG. Treatment began when tumors were either 50 or 300 mm3 in volume. Starting with small or large tumors, the ADR + 2-DG combination treatment resulted in significantly slower tumor growth (and therefore longer survival) than the control, 2-DG, or ADR treatments (P < 0.0001). Similar beneficial effects of combination treatment were found with 2-DG and paclitaxel in the MV522 non-small cell lung cancer xenograft model. In summary, the treatment of tumors with both the glycolytic inhibitor 2-DG and ADR or paclitaxel results in a significant reduction in tumor growth compared with either agent alone. Overall, these results, combined with our in vitro data, provide a rationale for initiating clinical trials using glycolytic inhibitors in combination with chemotherapeutic agents to increase their therapeutic effectiveness.

Genome-Wide Association Meta-analysis of Neuropathologic Features of Alzheimer's Disease and Related Dementias

Alzheimers disease (AD) and related dementias are a major public health challenge and present a therapeutic imperative for which we need additional insight into molecular pathogenesis. We performed a genome-wide association study and analysis of known genetic risk loci for AD dementia using neuropathologic data from 4,914 brain autopsies. Neuropathologic data were used to define clinico-pathologic AD dementia or controls, assess core neuropathologic features of AD (neuritic plaques, NPs; neurofibrillary tangles, NFTs), and evaluate commonly co-morbid neuropathologic changes: cerebral amyloid angiopathy (CAA), Lewy body disease (LBD), hippocampal sclerosis of the elderly (HS), and vascular brain injury (VBI). Genome-wide significance was observed for clinico-pathologic AD dementia, NPs, NFTs, CAA, and LBD with a number of variants in and around the apolipoprotein E gene (APOE). GalNAc transferase 7 (GALNT7), ATP-Binding Cassette, Sub-Family G (WHITE), Member 1 (ABCG1), and an intergenic region on chromosome 9 were associated with NP score; and Potassium Large Conductance Calcium-Activated Channel, Subfamily M, Beta Member 2 (KCNMB2) was strongly associated with HS. Twelve of the 21 non-APOE genetic risk loci for clinically-defined AD dementia were confirmed in our clinico-pathologic sample: CR1, BIN1, CLU, MS4A6A, PICALM, ABCA7, CD33, PTK2B, SORL1, MEF2C, ZCWPW1, and CASS4 with 9 of these 12 loci showing larger odds ratio in the clinico-pathologic sample. Correlation of effect sizes for risk of AD dementia with effect size for NFTs or NPs showed positive correlation, while those for risk of VBI showed a moderate negative correlation. The other co-morbid neuropathologic features showed only nominal association with the known AD loci. Our results discovered new genetic associations with specific neuropathologic features and aligned known genetic risk for AD dementia with specific neuropathologic changes in the largest brain autopsy study of AD and related dementias.

Soluble CD44 Is a Potential Marker for the Early Detection of Head and Neck Cancer

Introduction: Head and neck squamous cell carcinoma (HNSCC) is a devastating and deadly disease, largely because it is diagnosed in late stage. Cure rates, currently at 50%, could increase to >80% with early detection. In this study, we evaluate soluble CD44 (solCD44) as an early detection tool for HNSCC by determining whether it reliably distinguishes HNSCC from benign disease of the upper aerodigestive tract. Methods: We carried out the solCD44 ELISA on oral rinses from 102 patients with HNSCC and 69 control patients with benign diseases of upper aerodigestive tract to determine the sensitivity and specificity of the test for differentiating HNSCC from benign disease. Furthermore, we did a pilot study using methylation-specific PCR primers on oral rinses from 11 HNSCC patients with low solCD44 levels and 10 benign disease controls. Results: Mean salivary solCD44 levels were 24.4 ± 32.0 ng/mL for HNSCC patients (range, 0.99-201 ng/mL) and 9.9 ± 16.1 ng/mL (range, 0.73-124 ng/mL) for the patients with benign disease (P < 0.0001). Depending on cutoff point and HNSCC site, sensitivity ranged from 62% to 70% and specificity ranged from 75% to 88%. Nine of 11 HNSCC and 0 of 10 controls with low solCD44 levels showed hypermethylation of the CD44 promoter. Conclusions: SolCD44 is elevated in the majority of HNSCC and distinguishes cancer from benign disease with high specificity. Whereas the solCD44 test lacks sensitivity by itself, methylation status of the CD44 gene seems to complement the solCD44 test. Our pilot data indicate that, together, these markers will detect HNSCC with very high sensitivity and specificity. (Cancer Epidemiol Biomarkers Prev 2007;16(7):1348–55)

SECOND PRIMARY CANCER AFTER RADIOTHERAPY FOR PROSTATE CANCER : A SEER ANALYSIS OF BRACHYTHERAPY VERSUS EXTERNAL BEAM RADIOTHERAPY

PURPOSE To determine the incidence of second primary cancers (SPCs) and radiotherapy-induced SPCs (RTSPCs). PATIENTS AND METHODS The incidence of SPCs and RTSPCs was compared among four treatment groups with locoregional prostate adenocarcinoma in the 1973-2002 Surveillance, Epidemiology, and End Results database. These groups were no radiotherapy (RT), no surgery (Group 1); external beam RT (EBRT) (Group 2); brachytherapy (Group 3); and a combination of EBRT and brachytherapy (Group 4). RESULTS The age-adjusted estimates of SPCs were greater with EBRT than with brachytherapy (2,178 vs. 1,901 SPCs/100,000; p = 0.025) or with the no RT, no surgery group (1,971 SPCs/100,000; p <0.0001). The age-adjusted rate of late SPC (>or=5 years) for EBRT (2,425 SPCs/100,000) was only significantly greater (p <0.0001) than that for no RT, no surgery (1,950 SPCs/100,000). The hazard ratio adjusted for age, race/ethnicity, and grade was constant at 1.263 for EBRT compared with no RT, no surgery (p <0.0001) but varied with the length of follow-up in both the brachytherapy (0.721 at 5 years to 1.200 at 9 years) and combination (0.920 at 5 years to 1.317 at 9 years) groups. The incidence of RTSPCs was only significantly different between the no RT, no surgery group and the EBRT group, with an increase of 162 cases/100,000 or a 0.16% increased SPC risk (p = 0.023). No significant differences in the incidence of RTSPC were seen between the RT groups. CONCLUSION No significant differences were seen in the incidence of RTSPCs between the RT groups. The initial smaller relative risk of overall SPCs in the brachytherapy group increased with time until the curves converged, suggesting that the effect had resulted from patient selection bias.

Salivary Soluble CD44: A Potential Molecular Marker for Head and Neck Cancer

Objective: Head and neck squamous cell carcinoma (HNSCC) is a debilitating disease which is cured only 50% of the time. If diagnosed early, survival rates could reach 80%, but there is currently no practical method for early detection. CD44 comprises a family of isoforms that, in certain tumors, are alternatively spliced and overexpressed in tissues and circulation. Here we examine salivary soluble CD44 (solCD44) expression in HNSCC patients and normal controls to determine its potential as a screening tool. Method: We did a solCD44 ELISA on saliva from 26 HNSCC patients, 10 normal volunteers, conditioned media (CM) of 4 HNSCC cell lines, and 1 CD44-negative cell line (COS-7). Western blot was done on CM from 2 HNSCC cell lines (UMSS11B and FaDu), COS-7, 3 HNSCC, and 2 normal saliva specimens to verify ELISA antibody specificity. SolCD44 levels were significantly elevated in HNSCC patients compared with normal controls (7.85 ng/mL for HNSCC patients and 1.09 ng/mL for normal controls, P < 0.001). Results: The test detected 79% of mucosally invasive HNSCC using preliminary cutoff points. SolCD44 levels did not vary significantly with tumor size, stage, recurrence, history of radiation treatment, or tobacco and alcohol risk factors. A 65 to 75 kDa band, corresponding to solCD44, was detected in all of the HNSCC cell line CM and saliva whereas normal samples showed a fainter band or were undetectable. Conclusion: In this preliminary analysis, the salivary solCD44 ELISA seems to effectively detect HNSCC at all stages. Further study is indicated because early detection is clearly important in this disease.

Repeat expansions in the C9ORF72 gene contribute to Alzheimer's disease in Caucasians

Recently, a hexanucleotide repeat expansion in the C9ORF72 gene has been identified to account for a significant portion of Caucasian families affected by frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Given the clinical overlap of FTD with Alzheimers disease (AD), we hypothesized that C9ORF72 expansions might contribute to AD. In Caucasians, we found C9ORF72 expansions in the pathogenic range of FTD/ALS (>30 repeats) at a proportion of 0.76% in AD cases versus 0 in control subjects (p = 3.3E-03; 1182 cases, 1039 controls). In contrast, no large expansions were detected in individuals of African American ethnicity (291 cases, 620 controls). However, in the range of normal variation of C9ORF72 expansions (0-23 repeat copies), we detected significant differences in distribution and mean repeat counts between Caucasians and African Americans. Clinical and pathological re-evaluation of identified C9ORF72 expansion carriers revealed 9 clinical and/or autopsy confirmed AD and 2 FTD final diagnoses. Thus, our results support the notion that large C9ORF72 expansions lead to a phenotypic spectrum of neurodegenerative disease including AD.

Characterization of CD44v3-containing isoforms in head and neck cancer.

Head and neck squamous cell carcinoma (HNSCC) is a debilitating and deadly disease that is only cured 50% of the time. A better understanding of the molecular mechanisms involved in HNSCC progression may lead to earlier detection and improved cure rates. CD44 is a ubiquitous transmembrane glycoprotein comprising a family of alternatively spliced isoforms involved in cell migration and cell proliferation. CD44 isoforms containing the variant 3 (v3) exon include a growth factor binding site and may be involved in tumor progression. To characterize CD44v3-containing isoforms expression in HNSCC we purified RNA from four HNSCC cell lines and performed RTPCR using junction primer strategies followed by gel elecrophoresis. Cloning and sequencing of HNSCC cell line PCR products revealed two isoforms. One of these, CD44v3-10, has been previously described. The other isoform, CD44v3, has not been characterized in HNSCC tissues. To further study this isoform, we purified RNA from 19 HNSCC tissues, 7 normal margin tissues and 5 true normal tissues. Following reversetranscription, we performed quantitative PCR using junction primers specific for CD44v3. Results show that HNSCC tumor tissues expressed mean CD44v3 levels that were elevated 4.5 times more than true normal tissues (p

Salivary protein and solCD44 levels as a potential screening tool for early detection of head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a devastating disease usually diagnosed at a late stage when cure rates are 40%. We examined a simple and inexpensive molecular tool that may aid HNSCC detection.

Common susceptibility variants examined for association with dilated cardiomyopathy.

Rare mutations in more than 20 genes have been suggested to cause dilated cardiomyopathy (DCM), but explain only a small percentage of cases, mainly in familial forms. We hypothesised that more common variants may also play a role in increasing genetic susceptibility to DCM, similar to that observed in other common complex disorders.

Quality-of-life assessment after hyperfractionated radiation therapy and 5-fluorouracil, cisplatin, and paclitaxel (Taxol) in inoperable and/or unresectable head and neck squamous cell carcinoma

Purpose:To determine quality of life (QOL) after hyperfractionated radiation and chemotherapy. Materials and Methods:Functional Assessment of Cancer Therapy (FACT) and the Functional Assessment of Cancer Therapy–Head and Neck (FACT H-N) questionnaires were administered to protocol patients at baseline study entry, during and at the completion of therapy, and during subsequent follow-up. Results:Twenty-four patients completed baseline QOL questionnaires. Six subsequent assessments were given to patients who were available for follow-up. Social/family well-being and relationship with doctor subscores were not significantly different from baseline. Emotional well-being was not different from baseline initially, but actually showed a significant increase 6 months after completion of radiation, seen on assessments 5 and 6 (P < 0.01). Physical and functional well-being subscores, total FACT-G score, head and neck subscores, and total FACT H-N score all showed initial decreases during, at the completion of radiation, or, in some subscores, up to 3 months postradiation. However, all these scores recovered to baseline levels. These scores subsequently showed a significant increase after 6 months to 1 year in all but the physical well-being and head and neck subscores, which remained at baseline. Conclusion:QOL scores returned to baseline levels or increased at 6 to 12 months postradiation in long-term survivors who completed QOL questionnaires.