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Biomedical subjects

John Hay

Publications and source records attributed to John Hay.

At least 19 recordsLinked to original sources
PubMed2006

Anaplastic thyroid carcinoma: expression profile of targets for therapy offers new insights for disease treatment.

BACKGROUND: Anaplastic thyroid cancer is an endocrine malignancy. Its rare and rapidly lethal disease course has made it challenging to study. Little is known regarding the expression by anaplastic tumors of molecular targets for new human anticancer agents that have been studied in the preclinical or clinical setting. The objective of this work was to evaluate the expression profile of anaplastic thyroid tumors for molecular targets for treatment. METHODS: Of the 94 cases of anaplastic thyroid cancers diagnosed and treated in British Columbia, Canada over a 20-year period (1984-2004), 32 cases (34%) had adequate archival tissue available for evaluation. A tissue microarray was constructed from these anaplastic thyroid tumors and immunohistochemistry was utilized to evaluate expression of 31 molecular markers. The markers evaluated were: epidermal growth factor receptor (EGFR), HER2, HER3, HER4, ER, PR, uPA-R, clusterin, E-cadherin, beta-catenin, AMF-R, c-kit, VEGF, ILK, aurora A, aurora B, aurora C, RET, CA-IX, IGF1-R, p53, MDM2, p21, Bcl-2, cyclin D1, cyclin E, p27, calcitonin, MIB-1, TTF-1, and thyroglobulin. RESULTS: A single tumor with strong calcitonin expression was identified as a poorly differentiated medullary carcinoma and excluded from the study cohort. The mean age of the anaplastic cohort was 66 years; 16 patients (51%) were females, and the median patient survival was 23 weeks. A wide range in molecular marker expression was observed by the anaplastic thyroid cancer tumors (0-100%). The therapeutic targets most frequently and most strongly overexpressed by the anaplastic tumors were: beta-catenin (41%), aurora A (41%), cyclin E (67%), cyclin D1 (77%), and EGFR (84%). CONCLUSIONS: Anaplastic thyroid tumors exhibit considerable derangement of their cell cycle and multiple signal transduction pathways that leads to uncontrolled cellular proliferation and the development of genomic instability. This report is the first to comprehensively evaluate a panel of molecular targets for therapy of anaplastic thyroid cancer and supports the development of clinical trials with agents such as cetuximab, small-molecule tyrosine kinase inhibitors, and aurora kinase inhibitors, which may offer new hope for individuals diagnosed with this fatal thyroid malignancy.

Aged↗
PubMed2006

The varicella-zoster virus (VZV) ORF9 protein interacts with the IE62 major VZV transactivator.

The varicella-zoster virus (VZV) ORF9 protein is a member of the herpesvirus UL49 gene family but shares limited identity and similarity with the UL49 prototype, herpes simplex virus type 1 VP22. ORF9 mRNA is the most abundantly expressed message during VZV infection; however, little is known concerning the functions of the ORF9 protein. We have found that the VZV major transactivator IE62 and the ORF9 protein can be coprecipitated from infected cells. Yeast two-hybrid analysis localized the region of the ORF9 protein required for interaction with IE62 to the middle third of the protein encompassing amino acids 117 to 186. Protein pull-down assays with GST-IE62 fusion proteins containing N-terminal IE62 sequences showed that amino acids 1 to 43 of the acidic transcriptional activation domain of IE62 can bind recombinant ORF9 protein. Confocal microscopy of transiently transfected cells showed that in the absence of other viral proteins, the ORF9 protein was localized in the cytoplasm while IE62 was localized in the nucleus. In VZV-infected cells, the ORF9 protein was localized to the cytoplasm whereas IE62 exhibited both nuclear and cytoplasmic localization. Cotransfection of plasmids expressing ORF9, IE62, and the viral ORF66 kinase resulted in significant colocalization of ORF9 and IE62 in the cytoplasm. Coimmunoprecipitation experiments with antitubulin antibodies indicate the presence of ORF9-IE62-tubulin complexes in infected cells. Colocalization of ORF9 and tubulin in transfected cells was visualized by confocal microscopy. These data suggest a model for ORF9 protein function involving complex formation with IE62 and possibly other tegument proteins in the cytoplasm at late times in infection.

Amino Acid Sequence↗
PubMed2006

Adverse event reporting and developments in radiation biology after normal tissue injury: International Atomic Energy Agency consultation.

PURPOSE: Recent research has enhanced our understanding of radiation injury at the molecular-cellular and tissue levels; significant strides have occurred in standardization of adverse event reporting in clinical trials. In response, the International Atomic Energy Agency, through its Division of Human Health and its section for Applied Radiation Biology and Radiotherapy, organized a consultation meeting in Atlanta (October 2, 2004) to discuss developments in radiobiology, normal tissue reactions, and adverse event reporting. METHODS AND MATERIALS: Representatives from cooperative groups of African Radiation Oncology Group, Curriculo Radioterapeutica Ibero Latino Americana, European Organization for Research and Treatment of Cancer, National Cancer Institute of Canada Clinical Trials Group, Radiation Therapy Oncology Group, and Trans-Tasman Radiation Oncology Group held the meeting discussion. RESULTS: Representatives of major radiotherapy groups/organizations and prominent leaders in radiotherapy discussed current understanding of normal tissue radiobiologic effects, the design and implementation of future clinical and translational projects for normal tissue injury, and the standardization of adverse-event reporting worldwide. CONCLUSIONS: The consensus was to adopt NCI comprehensive adverse event reporting terminology and grading system (CTCAE v3.0) as the new standard for all cooperative group trials. Future plans included the implementation of coordinated research projects focusing on normal tissue biomarkers and data collection methods.

Biomarkers↗
PubMed2006

Derangement of the E-cadherin/catenin complex is involved in transformation of differentiated to anaplastic thyroid carcinoma.

BACKGROUND: Anaplastic thyroid cancer arises, or transforms, from pre-existing differentiated thyroid cancer. E-cadherin functions as a cell-cell adhesion molecule that complexes with catenin proteins for function. The objective of this study was to evaluate the change in E-cadherin/beta-catenin expression in the transformation of differentiated to anaplastic thyroid carcinoma. METHODS: A tissue microarray was constructed from 12 anaplastic thyroid tumors and their adjacent associated differentiated foci. Immunohistochemistry was used to evaluate tumor expression of E-cadherin and beta-catenin. RESULTS: There was decreased expression of E-cadherin and beta-catenin by the anaplastic tumors when compared with the differentiated thyroid tumors from which they evolved. The expression of E-cadherin and beta-catenin was 92% and 67%, respectively, by the differentiated thyroid carcinoma, and 17% and 50%, respectively, by the anaplastic tumors. CONCLUSIONS: This report shows that derangement of the E-cadherin/catenin complex is associated with the transformation of differentiated into anaplastic thyroid carcinoma.

Aged↗
PubMed2006

Promoter activation by the varicella-zoster virus major transactivator IE62 and the cellular transcription factor USF.

The varicella-zoster virus major transactivator, IE62, can activate expression from homologous and heterologous promoters. High levels of IE62-mediated activation appear to involve synergy with cellular transcription factors. The work presented here focuses on functional interactions of IE62 with the ubiquitously expressed cellular factor USF. We have found that USF can synergize with IE62 to a similar extent on model minimal promoters and the complex native ORF28/29 regulatory element, neither of which contains a consensus IE62 binding site. Using Gal4 fusion constructs, we have found that the activation domain of USF1 is necessary and sufficient for synergistic activation with IE62. We have mapped the regions of USF and IE62 required for direct physical interaction. Deletion of the required region within IE62 does not ablate synergistic activation but does influence its efficiency depending on promoter architecture. Both proteins stabilize/increase binding of TATA binding protein/TFIID to promoter elements. These findings suggest a novel mechanism for the observed synergistic activation which requires neither site-specific IE62 binding to the promoter nor a direct physical interaction with USF.

Binding Sites↗
PubMed2005

Toluidine blue staining identifies high-risk primary oral premalignant lesions with poor outcome.

There is a pressing need for the development of visual aids that will facilitate the detection of oral premalignant lesions (OPLs) with a high-risk of progression. Preliminary data suggest that toluidine blue stain may be preferentially retained by OPLs with high-risk molecular clones. In this study, we monitored OPLs from 100 patients without any history of oral cancer for an average of 44 months in order to evaluate the association of toluidine blue status with clinicopathologic risk factors, molecular patterns (microsatellite analysis on seven chromosome arms: 3p, 9p, 4q, 8p, 11q, 13q, and 17p) and outcome. Toluidine blue-positive staining correlated with clinicopathologic risk factors and high-risk molecular risk patterns. Significantly, a >6-fold elevation in cancer risk was observed for toluidine blue-positive lesions, with positive retention of the dye present in 12 of the 15 lesions that later progressed to cancer (P = 0.0008). This association of toluidine blue status with risk factors and outcome was evident even when the analysis was restricted to OPLs with low-grade or no dysplasia. Our results suggest the potential use of toluidine blue in identifying high-risk OPLs.

Adult↗
PubMed2005

Cell-type-dependent activation of the cellular EF-1alpha promoter by the varicella-zoster virus IE63 protein.

The varicella-zoster virus (VZV) IE63 protein is abundantly expressed during productive viral infection and is one of six gene products that appear to be expressed during latency. We have found that the IE63 protein can activate expression from the cellular EF-1alpha promoter in the absence of other viral proteins. The VZV IE62 protein, in contrast, was not found to transactivate this promoter. These data indicate that IE63 can function independently of the IE62 protein to positively influence the cellular transcription apparatus. We show that IE63 activation of the EF-1alpha promoter is cell type dependent and have examined the effects of point mutations important for IE63 phosphorylation and virus viability on this activation.

Binding Sites↗
PubMed2005

Role of the varicella-zoster virus gene product encoded by open reading frame 35 in viral replication in vitro and in differentiated human skin and T cells in vivo.

Although genes related to varicella-zoster virus (VZV) open reading frame 35 (ORF35) are conserved in the herpesviruses, information about their contributions to viral replication and pathogenesis is limited. Using a VZV cosmid system, we deleted ORF35 to produce two null mutants, designated rOkaDelta35(#1) and rOkaDelta35(#2), and replaced ORF35 at a nonnative site, generating two rOkaDelta35/35@Avr mutants. ORF35 Flag-tagged recombinants were made by inserting ORF35-Flag at the nonnative Avr site as the only copy of ORF35, yielding rOkaDelta35/35Flag@Avr, or as a second copy, yielding rOka35Flag@Avr. Replication of rOkaDelta35 viruses was diminished in melanoma and Vero cells in a 6-day analysis of growth kinetics. Plaque sizes of rOkaDelta35 mutants were significantly smaller than those of rOka in melanoma cells. Infection of melanoma cells with rOkaDelta35 mutants was associated with disrupted cell fusion and polykaryocyte formation. The small plaque phenotype was not corrected by growth of rOkaDelta35 mutants in melanoma cells expressing the major VZV glycoprotein E, gE. The rOkaDelta35/35@Avr viruses displayed growth kinetics and plaque morphologies that were indistinguishable from those of rOka. Analysis with ORF35-Flag recombinants showed that the ORF35 gene product localized predominantly to the nuclei of infected cells. Evaluations in the SCIDhu mouse model demonstrated that ORF35 was required for efficient VZV infection of skin and T-cell xenografts, although the decrease in infectivity was most significant in skin. These mutagenesis experiments indicated that ORF35 was dispensable for VZV replication, but deleting ORF35 diminished growth in cultured cells and was associated with attenuated VZV infection of differentiated human skin and T cells in vivo.

Base Sequence↗
PubMed2004

Silver leaf nylon dressing to prevent radiation dermatitis in patients undergoing chemotherapy and external beam radiotherapy to the perineum.

PURPOSE: Silver-leaf nylon dressing (SLND) has been shown to have effective antimicrobial activity and to enhance healing in burns and skin grafts. The purpose of this study was to evaluate the value of SLND in preventing radiation dermatitis in patients undergoing radiotherapy to target volumes that included the perineum and concurrent chemotherapy. METHODS AND MATERIALS: Fifteen consecutive patients with either anal canal or gynecologic cancer were offered the SLND as a preventive intervention. The evaluation was based on standardized photographs taken at the end of treatment. A historical control group of 15 patients with the same neoplasms who received standard skin care was assessed in the same fashion. Ten observers unaware of the treatment intervention were enrolled in the evaluation of the skin changes. The Mann-Whitney U test was used to assess the statistical significance of the differences in the dermatitis scores between the two patient groups. RESULTS: The mean dermatitis score for controls was 2.62 (standard deviation, 0.48). The mean score for the SLND group was significantly lower at 1.16 (standard deviation, 0.40; p <0.0001). CONCLUSION: The results of this study suggest that SLND is effective in reducing radiation dermatitis, apparently because of its antibacterial properties.

Adult↗
PubMed2004

Carcinoma of the tongue: a case series analysis of clinical presentation, risk factors, staging, and outcome.

OBJECTIVE: Oral cancer is primarily a disease of epithelial origin. The tongue is the most common site of oral cancer. Oropharyngeal cancer accounts for approximately 2% of all cancer deaths. The purpose of this study was to analyze a case series of patients with tongue cancer. STUDY DESIGN: The medical records of 322 consecutive patients diagnosed with squamous cell carcinoma (SCC) of the tongue treated from 1979-1994 were reviewed. RESULTS: Patients had a mean age of 61.1 years and a 1.5:1 male to female ratio. Approximately, half of the cancers were diagnosed at an advanced stage and most involved the base of the tongue. The majority of oral tongue tumors were diagnosed at an early stage and had more well-differentiated cell types than those of the base of the tongue. Localized discomfort was the most common complaint (66.5%), present for up to 6 months in patients prior to diagnosis and were related to the oral tongue in 90% of cases. Symptoms associated with base of tongue lesions included neck masses, dysphagia, ear pain, and weight loss. Seventy-nine percent of the patients smoked, 58% consumed alcohol on a daily basis, and 43% consumed more than 4 alcoholic drinks daily. Primary radiotherapy was the treatment of 49.6% lesions, of which 57% were at an early stage at diagnosis. The mean overall survival was 3 years and 5 months, with a 5-year overall survival of 40%. Patients with stage 1 tumors had a disease-specific survival of over 80%. The 5-year survival of patients with cancer of the oral tongue was 43% and cancer of the base of the tongue was 27%. CONCLUSION: The prognosis is poorer for patients presenting with advanced stage and with tumors involving the base of the tongue. Symptoms were more common in tumors of the oral tongue, which likely results in earlier diagnosis. Patients with SCC of the base of the tongue presented with advanced stage of disease and were typically poorly differentiated lesions.

Adolescent↗
PubMed2004

The DNA element controlling expression of the varicella-zoster virus open reading frame 28 and 29 genes consists of two divergent unidirectional promoters which have a common USF site.

The mechanism of the divergent expression of the varicella-zoster virus (VZV) ORF 28 and ORF 29 genes from a common intergenic DNA element, the ORF 28/29 promoter, is of interest based on the observation that both genes are expressed during VZV lytic infection but only the ORF 29 gene is expressed in latently infected neurons. In the work presented here, expression driven by the ORF 28/29 intergenic region was examined. We found that the promoter activity towards the ORF 29 direction is more responsive to activation by the major viral transactivator IE62 than that towards the ORF 28 direction in the context of our experimental system. Analysis of the functional DNA elements involved in IE62 activation of the bidirectional ORF 28/29 regulatory element revealed that in both transfected and VZV-superinfected cells it is a fusion of two unidirectional promoters overlapping an essential USF binding site but with distinct TATA elements. A single TATA element directs expression in the ORF 28 direction, whereas the two TATA elements directing ORF 29 gene expression are alternatively and differentially utilized for transcription initiation. We also identified an Sp1 site localized proximal to the ORF 28 gene which functions as an activator element for expression in both directions. These results indicate that the ORF 28 and ORF 29 genes can be expressed either coordinately or independently and that the observed expression of only the ORF 29 gene during VZV latency may involve neuron-specific cellular factors and/or structural aspects of the latent viral genome.

Base Sequence↗
PubMed2004

The immediate-early 63 protein of Varicella-Zoster virus: analysis of functional domains required for replication in vitro and for T-cell and skin tropism in the SCIDhu model in vivo.

The immediate-early 63-kDa (IE63) protein of varicella-zoster virus (VZV) is a phosphoprotein encoded by open reading frame (ORF) ORF63/ORF70. To identify functional domains, 22 ORF63 mutations were evaluated for effects on IE63 binding to the major VZV transactivator, IE62, and on IE63 phosphorylation and nuclear localization in transient transfections, and after insertion into the viral genome with VZV cosmids. The IE62 binding site was mapped to IE63 amino acids 55 to 67, with R59/L60 being critical residues. Alanine substitutions within the IE63 center region showed that S165, S173, and S185 were phosphorylated by cellular kinases. Four mutations that changed two putative nuclear localization signal (NLS) sequences altered IE63 distribution to a cytoplasmic/nuclear pattern. Only three of 22 mutations in ORF63 were compatible with recovery of infectious VZV from our cosmids, but infectivity was restored by inserting intact ORF63 into each mutated cosmid. The viable IE63 mutants had a single alanine substitution, altering T171, S181, or S185. These mutants, rOKA/ORF63rev[T171], rOKA/ORF63rev[S181], and rOKA/ORF63rev[S185], produced less infectious virus and had a decreased plaque phenotype in vitro. ORF47 kinase protein and glycoprotein E (gE) synthesis was reduced, indicating that IE63 contributed to optimal expression of early and late gene products. The three IE63 mutants replicated in skin xenografts in the SCIDhu mouse model, but virulence was markedly attenuated. In contrast, infectivity in T-cell xenografts was not altered. Comparative analysis suggested that IE63 resembled the herpes simplex virus type 1 U(S)1.5 protein, which is expressed colinearly with ICP22 (U(S)1). In summary, most mutations of ORF63 made with our VZV cosmid system were lethal for infectivity. The few IE63 changes that were tolerated resulted in VZV mutants with an impaired capacity to replicate in vitro. However, the IE63 mutants were attenuated in skin but not T cells in vivo, indicating that the contribution of the IE63 tegument/regulatory protein to VZV pathogenesis depends upon the differentiated human cell type which is targeted for infection within the intact tissue microenvironment.

Animals↗
PubMed2003

Interaction between the varicella zoster virus IE62 major transactivator and cellular transcription factor Sp1.

The varicella zoster virus (VZV) IE62 protein is involved in the activation of expression of all three kinetic classes of VZV proteins. Analysis of the viral promoter for VZV glycoprotein I has shown that the cellular factor Sp1 is involved in or required for the observed IE62 mediated activation. Co-immunoprecipitation experiments show that the two proteins are present in a complex in VZV-infected cells. Protein affinity pull-down assays using recombinant proteins showed that IE62 and Sp1 interact in the absence of any other viral and cellular proteins. Mapping studies using GST-fusion proteins containing truncations of IE62 and Sp1 have delimited the interacting regions to amino acids 612-778 in Sp1 and amino acids 226-299 in IE62. The region identified in Sp1 is involved in DNA-binding, synergistic Sp1 activation, and Sp1 interaction with cellular transcription factors. The interacting region identified in IE62 overlaps with or borders on sites involved in interactions with the VZV IE4 protein and the cellular factors TBP and TFIIB. Assays using wild-type and mutant promoter elements indicate that Sp1 is involved in recruitment of IE62 to the gI promoter and IE62 enhances Sp1 and TBP binding.

DNA↗
PubMed2003

Habitual physical activity levels and health outcomes of Ontario youth.

Physical activity, sport participation, attitude towards physical education, aerobic fitness, body composition and frequency of upper respiratory tract infections (URTI) were investigated in 256 adolescents [mean age 14.3 (0.3) years] from the Niagara Region Public Schools in Canada. Subjects performed the 20-m shuttle run for prediction of aerobic fitness, and bioelectrical impedance analysis was used to assess relative body fat (%BF). Standardized questionnaires were used to determine physical activity-related variables and frequency of URTI. Males were more active, demonstrated higher shuttle run score, lower %BF and recorded fewer sickness days. In the complete cohort and in males, those who spent less time in sporting activities showed significantly (P<0.05) higher %BF, lower aerobic fitness and higher URTI frequency. Active females differed from hypoactive females only in %BF. Girls also showed significantly (P<0.05) less enjoyment of physical education than boys, which may explain their lack (P<0.05) of participation in sporting activities.

Adolescent↗
PubMed2003

Cellular factors and IE62 activation of VZV promoters.

The varicella zoster virus IE62 protein transactivates promoters representing all three kinetic classes of viral genes. This is accomplished in conjunction with the general transcription machinery of the cell and specific cellular transcription factors that act at sites located within viral promoters. The incidence of a subset of specific recognition sites was examined for the ubiquitous cellular factors Sp1 and USF within the VZV genome. Evidence is also presented for a direct physical interaction between Sp1 and IE62.

Base Sequence↗
PubMed2003

Effect of emergent presentation on outcome from rectal cancer management.

BACKGROUND: We have previously reported outcomes for all rectal cancers in BC in 1996. We found that our local recurrence rates and survival were suboptimal relative to current standards in recent literature. METHODS: In this retrospective, population-based study, we report the influence of emergent presentation (obstruction, perforation, massive hemorrhage) on outcomes, types of surgical procedures and use of staging investigations, and use of adjuvant radiation and chemotherapy. RESULTS: There were 452 invasive adenocarcinomas of the rectum of which 45 were emergent and 407 nonemergent. Disease-specific survival at 4 years for emergent and nonemergent stage II cancers were 66% versus 80%, respectively, and for stage III cancers, 60% versus 73%, respectively (P <0.04). Local recurrence rates at 4 years for emergent and nonemergent stage II cancers were 20% versus 15%, respectively, and for stage III cancers, 70% and 20%, respectively (P <0.05). Surgical resection more frequently involved a stoma for emergent (60%) than for nonemergent (35%) cases (P <0.01). Percent of patients having complete staging investigations were similar between emergent (42%) and nonemergent patients (39%). Adjuvant radiation was given in similar proportion to emergent (61%) and nonemergent (55%) patients. Adjuvant chemotherapy was given to a slightly higher proportion of emergent patients (63%) than nonemergent patients (43%). CONCLUSIONS: We conclude that outcome from rectal cancer management is worse for emergent than nonemergent presentation. Since there is no difference in use of staging investigations or adjuvant therapy, the difference in outcome is likely due to difference in surgical technique between emergent and nonemergent cases.

Adenocarcinoma↗
PubMed2003

Promoter sequences of varicella-zoster virus glycoprotein I targeted by cellular transactivating factors Sp1 and USF determine virulence in skin and T cells in SCIDhu mice in vivo.

Varicella-zoster virus (VZV) glycoprotein I is dispensable in cell culture but necessary for infection of human skin and T cells in SCIDhu mice in vivo. The gI promoter contains an activating upstream sequence that binds the cellular transactivators specificity factor 1 (Sp1) and upstream stimulatory factor (USF) and an open reading frame 29 (ORF29)-responsive element (29RE), which mediates enhancement by ORF29 DNA binding protein of immediate-early 62 (IE62)-induced transcription. Recombinants, rOKAgI-Sp1 and rOKAgI-USF, with two base pair substitutions in Sp1 or USF sites, replicated like rOKA in vitro, but infectivity of rOKAgI-Sp1 was significantly impaired in skin and T cells in vivo. A double mutant, rOKAgI-Sp1/USF, did not replicate in skin but yielded low titers of infectious virus in T cells. The repaired protein, rOKAgI:rep-Sp1/USF, was as infectious as rOKA. Thus, disrupting gI promoter sites for cellular transactivators altered VZV virulence in vivo, with variable consequences related to the cellular factor and the host cell type. Mutations in the 29RE of the gI promoter were made by substituting each of four 10-bp blocks in this region with a 10-bp sequence, GATAACTACA, that was predicted to interfere with enhancer effects of the ORF29 protein. One of these mutants, which was designated rOKAgI-29RE-3, had diminished replication in skin and T cells, indicating that ORF29 protein-mediated enhancement of gI expression contributes to VZV virulence. Mutations within promoters of viral genes that are nonessential in vitro should allow construction of recombinant herpesviruses that have altered virulence in specific host cells in vivo and may be useful for designing herpesviral gene therapy vectors and attenuated viral vaccines.

Animals↗