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Gary L Clayman

Publications and source records attributed to Gary L Clayman.

47 records · Page 3Linked to original sources
PubMed2003

Identification of 9 genes differentially expressed in head and neck squamous cell carcinoma.

BACKGROUND: Current treatment modalities in squamous cell carcinoma of the head and neck have failed to improve survival. Advances in the discovery of novel biomarkers and targets for therapy are necessary. DESIGN: Differential display and microarray analysis were used to identify differences in gene expression between squamous carcinoma and matched nonmalignant biopsy specimens. Differences in gene expression found in vivo were also tested in vitro by comparing primary cultured normal oral epithelium with head and neck squamous cell carcinoma (HNSCC) cell lines. Results were confirmed by relative reverse transcriptase-polymerase chain reaction and immunohistochemical analysis. RESULTS: In tumors, microarray analysis showed down-regulation of calgranulin B (CAGB), CD24, lymphoepithelial Kazal-type-related inhibitor (LEKTI), zinc finger protein (ZNF-185), transglutaminase-3 (TGM3), and the ETS homologous factor (EHF). In addition, differential display revealed down-regulation of headpin. In contrast, periostin and the human homologue of the Drosophila white gene (ABCG1) were found to be up-regulated by microarray analysis and differential display, respectively. In HNSCC cell lines, LEKTI, ZNF-185, TGM3, headpin, and ABCG1 showed an expression pattern similar to that observed in tumor specimens. Periostin showed an opposite expression pattern in cell lines compared with that of tumor specimens. No consistent pattern of expression was found for CAGB, CD24, and EHF in cell lines. Immunohistochemical analysis revealed that the expression of headpin in nonmalignant mucosa was undetectable in tumors. CONCLUSION: Using differential display and microarray analysis, we have identified and confirmed the differential expression of 9 genes in HNSCC. Work is in progress to determine the biological significance of these genes and their potential as biomarkers or targets for therapy.

ATP Binding Cassette Transporter, Subfamily G, Mem↗
PubMed2003

Medullary thyroid cancer.

Medullary thyroid cancer is a rare neoplasm that arises from the parafollicular C cells. It occurs in a sporadic form, or less commonly as a hereditary form, as part of multiple endocrine neoplasia syndromes types 2A and 2B. The RET proto-oncogene is currently the primary factor that is implicated in the hereditary forms of this neoplasm. The knowledge about the genetic makeup of the neoplasm impacts upon management as it allows for screening, early detection, and prophylactic treatment. Surgery is the main modality that offers a cure. This entails a total thyroidectomy and vigilant management and surveillance of the neck. Prognosis of patients with MTC is variable, but the more constant factors that affect it are the stage of disease and the age of the patient. The emerging molecular genetic understanding of this malignancy will provide the foundation for prognostic and therapeutic decision-making in the future. Interdisciplinary management by surgeons, endocrinologists, pathologists, radiotherapists, radiologists, and medical oncologists should be sought.

Biomarkers, Tumor↗
PubMed2003

p53 mutations in human aggressive and nonaggressive basal and squamous cell carcinomas.

PURPOSE: The purpose is to investigate whether aggressive basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) differ from nonaggressive BCC and SCC with respect to the p53 mutation spectrum and whether specific mutations can serve as prognostic indicators of tumor aggressiveness. EXPERIMENTAL DESIGN: We analyzed 342 tissues from patients with aggressive and nonaggressive BCCs and SCCs for p53 mutations by single-strand conformation polymorphism and nucleotide sequencing. RESULTS: p53 mutations were detected in 33 of 50 aggressive BCCs (66%), 37 of 98 nonaggressive BCCs (38%), 28 of 80 aggressive SCCs (35%), 28 of 56 nonaggressive SCCs (50%), and 3 of 29 samples of sun-exposed skin (10%). About 71% of the p53 mutations detected in aggressive and nonaggressive BCCs and SCCs were UV signature mutations. The frequency of CC to TT mutations in aggressive (36%) and nonaggressive SCCs (39%) was 2-fold higher than in aggressive (18%) and nonaggressive (14%) BCCs. In contrast, aggressive BCCs had a higher frequency (24%) of transversions than nonaggressive BCCs (8%) and aggressive (14%) and nonaggressive (11%) SCCs did. CONCLUSIONS: Our results indicate that UV radiation is responsible for the induction of p53 mutations and perhaps for the initiation of both aggressive and nonaggressive BCCs and SCCs. Although some differences in p53 mutation frequency, types of mutation, and hot spots were seen between aggressive and nonaggressive BCCs and SCCs, these factors do not constitute as clear-cut diagnostic or prognostic indicators of tumor aggressiveness. Tumor aggressiveness may be attributable to other genetic changes or events that occur during tumor progression.

Adult↗
PubMed2003

Suppression of epidermal growth factor receptor, mitogen-activated protein kinase, and Pak1 pathways and invasiveness of human cutaneous squamous cancer cells by the tyrosine kinase inhibitor ZD1839 (Iressa).

Abnormalities in the expression and signaling pathways downstream of the epidermal growth factor receptor (EGFR) contribute to malignant transformation in human cancers, including those of the cutaneous epithelium. Accordingly, novel agents such as the EGFR tyrosine kinase inhibitor ZD1839 (Iressa), are promising, biologically based treatments that are currently in preclinical and clinical development. The process of tumor progression requires, among other steps, increased transformation, directional migration, and enhanced cell survival. This study explored the effect of ZD1839 on the stimulation of p42/44 mitogen-activated protein kinase (MAPK) and p21-activated kinase 1 (Pak1), which are vital for transformation, directional motility, and cell survival, using immortalized keratinocytes (HaCaT cells) and cutaneous squamous cell carcinoma cells. The EGFR and a number of effector kinases (mitogen-activated protein extracellular signal-regulated kinase kinase 1 and 2, MAPK, Pak1, p38, c-JunNH(2)-terminal kinase and extracellular signal-regulated kinase 1) and cell survival proteins (AKT, FKHR, and c-Src) showed constitutive pathway activation in HaCaT and cutaneous squamous cell carcinoma cells. ZD1839 effectively inhibited EGFR and MAPK activation and Pak1 activity in exponentially growing cancer cells. ZD1839 also suppressed EGF-induced stimulation of EGFR autophosphorylation on Y1086 and Y1068, MAPK phosphorylation on T402 and Y404, and Pak1 activity in a dose-dependent manner. In addition, ZD1839 blocked EGF-induced cytoskeleton remodeling, cell growth, and in vitro invasiveness of cancer cells and induced a differentiated squamous cell phenotype. These studies suggest that the EGFR-tyrosine kinase inhibitor ZD1839 may cause potent inhibition of the EGFR, MAPK, and Pak1 pathways, resulting in attenuation of transformed cell phenotypes and induced differentiation in human cancer cells deregulated in these growth factor receptor pathways.

Antineoplastic Agents↗
PubMed2002

Differential expression profiling of head and neck squamous carcinoma: significance in their phenotypic and biological classification.

The genetic events associated with the development and progression of head and neck squamous carcinoma (HNSC) are largely unknown. We analysed 12 matched pairs of histologically normal squamous mucosa and tumor specimens from six conventional and six phenotypic variants HNSC to define the differentially expressed genes in these tumors. Parallel expression analysis of 8055 unique genes was performed, and the level of the hybridization signal for each gene was measured after normalization. Hierarchical cluster analysis of the expressed genes showed distinct inter- and intra-tumoral patterns in and between conventional squamous carcinoma and squamous carcinoma variants. We also identified 26 (0.32%) differentially expressed genes that were consistently different between matched pairs of normal and tumor specimens; a selected set of the overexpressed genes was validated using real-time quantitative RT-PCR. The majority of the genes were associated with differentiation and proliferation. Our study defines a set of genes that could form the basis for the construction of limited HNSC targeted expression array and in-depth studies and further highlights gene profile differences that may be useful in pathobiologic classification of HNSC.

Adult↗
PubMed2002

A lymph node metastatic mouse model reveals alterations of metastasis-related gene expression in metastatic human oral carcinoma sublines selected from a poorly metastatic parental cell line.

BACKGROUND: Greater than 40% of patients with squamous cell carcinoma (SCC) of the oral cavity have lymph node metastasis at the time of diagnosis and a 5-year survival rate of less than 50%. Changes in gene expression that regulate metastasis of SCC to lymph nodes have not been identified. METHODS: To study metastasis of oral SCC, highly metastatic oral SCC cell lines from a poorly metastatic oral SCC cell line were established by in vivo selection using a lymph node metastatic mouse model. The metastatic potential of the cells was studied using Matrigel invasion and cell surface protein adhesion assays. mRNA and protein encoded from metastasis-related genes in the metastatic derivatives and in their parental cells were examined using Northern blot analysis, immunoblotting, rapid analysis of gene expression, and a cDNA microarray technique. RESULTS: The in vivo selected metastatic cells showed much higher Matrigel invasion capability than the parental cells. They also showed alterations in their adhesion properties to three cell surface proteins. Comparison of metastatic and nonmetastatic cells revealed several significant alterations in the expression of metastasis-related genes, including up-regulation of the urokinase-type plasminogen activator receptor, integrin beta1, membrane type 1-matrix metalloproteinase, and down-regulation of protease-activated receptor-1. CONCLUSIONS: To the authors' knowledge, the current study is the first to report on gene expression analysis using a lymph node metastatic mouse model of human oral SCC. The data suggest that certain alterations of metastasis-related gene expression favor invasion of oral SCC and that cell surface proteins may play major roles in the metastasis of oral SCC to the lymph nodes.

Animals↗
PubMed2002

Serum squamous cell carcinoma antigen is a useful biologic marker in patients with inverted papillomas of the sinonasal tract.

BACKGROUND: Inverted papilloma (IP) is a frequent benign sinonasal tumor that is characterized histologically by squamous metaplasia, epithelial acanthosis, and hyperplasia of the nasal epithelium. Because of its high recurrence rate and malignant transformation potential, careful long-term follow up is necessary. METHODS: The purpose of the current report was to study the expression of squamous cell carcinoma (SCC) antigen in sinonasal IPs and to evaluate the usefulness of SCC antigen as a biologic marker for the follow-up of patients with sinonasal IP. The expression of SCCA1 in three sinonasal IP cases, three sinonasal SCC cases, and cases of normal nasal epithelium were examined by Western blot analysis, and the SCCA1 expression pattern in 31 IP specimens and 4 carcinoma in IP specimens were evaluated immunohistochemically. The serum levels of SCC antigen in 11 patients with sinonasal IP also were analyzed. RESULTS: SCCA1 was overexpressed in all three sinonasal IP tissues compared with sinonasal SCC tissues or normal nasal epithelium. SCCA1 cytoplasmic immunoreactivity was detected in the suprabasal epidermal keratinocytes of all 31 sinonasal IP cases. In the four carcinoma in IP specimens, SCCA1 expression in the papillomatous lesion was more intense than in the cancerous lesion. The serum SCC antigen level was high in 10 of 11 patients with IP (91%) and significantly decreased after surgical resection of the tumors. CONCLUSIONS: The results of the current study indicate that SCCA1 frequently is overexpressed and may play a biologic role in the development of sinonasal IPs. Serum SCC antigen may be a useful biologic marker in patients with sinonasal IP.

Adult↗
PubMed2002

A prospective study of intraoperative lymphatic mapping for head and neck cutaneous melanoma.

BACKGROUND: Intraoperative lymphatic mapping and sentinel lymph node biopsy have been used successfully to stage regional lymphatics for trunk and extremity melanomas. However, the accuracy and applicability of these techniques in the head and neck have not been determined conclusively. OBJECTIVE: To report the results of a prospective trial of intraoperative lymphatic mapping and sentinel lymph node identification in patients with head and neck cutaneous melanoma. METHODS: Using technetium Tc 99m--labeled sulfur colloid and isosulfan blue, intraoperative lymphatic mapping and sentinel lymph node identification were performed in 43 patients with melanomas of intermediate thickness. After the sentinel lymph nodes were identified in situ, an elective dissection of levels I through V or II through V was performed, based on the location of the primary tumor. The parotid, postauricular, and suboccipital lymphatics were dissected as clinically indicated. The sentinel lymph nodes were isolated ex vivo and evaluated pathologically by serial sectioning, and the accuracy of the lymphatic mapping was determined. RESULTS: Intraoperative lymphatic mapping identified 155 sentinel lymph nodes in 94 nodal basins, with a mean of 3.6 sentinel nodes and 2.2 basins per patient. Sentinel nodes were located in the parotid gland in 19 patients (44%), necessitating superficial parotidectomies, and they were distributed throughout nonadjacent nodal basins in 18 patients (42%). Nine patients (21%) had metastatic disease in 1 or more sentinel nodes, 3 of whom had metastatic disease in a nonsentinel node. No patient who had negative sentinel nodes had a positive nonsentinel node (false-negative incidence, 0). CONCLUSIONS: Although intraoperative lymphatic mapping accurately identifies sentinel lymph nodes for head and neck cutaneous melanomas, the multiplicity of these nodes, their widespread distribution, and their frequent location within the parotid gland may preclude sentinel lymph node biopsy in many patients. Therefore, we advocate selective lymphadenectomy of sentinel nodal basins, allowing histological staging of the regional lymphatics with limited morbidity. However, further study is necessary to define the true role of sentinel lymph node identification for head and neck cutaneous melanoma.

Head and Neck Neoplasms↗
PubMed2002

Suppression of type I interferon signaling proteins is an early event in squamous skin carcinogenesis.

PURPOSE: IFN-based therapy has been shown to be active in the treatmentof squamous cell carcinoma (SCC) of the skin, the most aggressive form of non-melanoma skin cancer. Based largely on this activity, we began programmatically examining the expression of IFN-stimulated gene factor 3 (ISGF-3) proteins (signal transducers and activators of transcription 1alpha/beta, signal transducers and activators of transcription 2, and p48), which are important mediators of IFN-alpha signaling, in skin premalignancy and SCC. Our previous preliminary studies suggested suppression of some or all of the ISGF-3 proteins in skin SCC. EXPERIMENTAL DESIGN: To determine the timing of the suppression of IFN-alpha signaling proteins in squamous skin carcinogenesis, we have now compared ISGF-3 expression by immunohistochemical staining in biopsies of actinic keratosis, a form of skin premalignancy, and matched normal skin. RESULTS: We observed a significant decrease in expression of one or more ISGF-3 proteins in 76% of patients with actinic keratosis (19 of 25 patients). In addition, we found a suppression of one or more ISGF-3 proteins in 67% of skin SCC patients tested (12 of 18 patients), confirming our previous observations. CONCLUSIONS: These data have led to the hypothesis that the suppressed expression of ISGF-3 proteins and consequent reduction in responsiveness to endogenous IFN likely are an early event in skin carcinogenesis.

Aged↗