Browsing by Subject "Microdissection"

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    3p21, 5q21, 9p21 and 17p13 allelic deletions accumulate in the dysplastic spectrum of laryngeal carcinogenesis and precede malignant transformation
    (Murcia : F. Hernández, 2003) Sanz Ortega, J.; Valor, C.; Saez, M.C.; Ortega, L.; Sierra, E.; Poch, J.; Hernández, S.; Sanz-Esponera, J.
    A tissue field of somatic genetic alterations precede the histopathological phenotypic changes of carcinoma. Loss of Heterozygosity (LOH) at the sites of known or putative tumor suppressor genes is a common genetic abnormality detected in precancerous conditions. These genomic changes could be of potential use in the diagnosis and prognosis of pre-malignant laryngeal lesions. Recently the concept of laryngeal intraepithelial neoplasia (LIN) was introduced. To evaluate patients with an increased risk of developing invasive laryngeal carcinoma via a dysplasia-carcinoma progression we investigated 102 microdissected cell populations. Cell populations were procured from 15 laryngectomy specimens with different peritumoral histological changes adjacent to the squamous cell carcinoma cells and 15 laryngeal endoscopic biopsies with no evidence of malignant transformation in a 6-10-year follow-up period. Histological diagnoses were subdivided into keratosis without dysplasia (KWD), with mild dysplasia (LIN 1), with moderate dysplasia (LIN 2), and with severe dysplasia or carcinoma in situ (LIN 3). Microsatellite analysis was performed with the aim of studying LOH of 5q21 (APC), 9p21 (p16), 3p21 and 17p13 (p53) chromosomal regions. Frequent allelic losses were found in carcinoma cells at p53 (54%), p16 (66%), 3p21(87%) and 5q21(58%). Identical LOH patterns were determined in 100% of the LIN3 peritumoral cells, 60% of LIN2, 50% of LIN 1 and 25% of KWD. In contrast, histologically normal mucosae, KWD and LIN1 lesions without malignant progression showed no allelic loss. These results show that dysplasia correlates with LOH at 3p21, 5q21, 9p21 and 17p13 in early laryngeal carcinogenesis. These genomic changes in pre-malignant laryngeal lesions could be of potential use as markers for cancer risk assessment.
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    Helicobacter pylori (H. pylori) molecular signature in conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma
    (Murcia : F. Hernández, 2004) Chan, Ch.Ch.; Smith, J.A.; Shen, D.; Ursea, R.; LeHoang, P.; Grossniklaus, H.E.
    Conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal marginal zone B-cell lymphoma that is characterized by an exaggerated clonal expansion of B cells, which implicate a pathological proliferative response to antigen(s) including bacteria. Helicobacter pylori (H. pylori) infection is recognized as one of the causative agents of gastric MALT lymphoma; however, it has not been reported in extra gastric MALT lymphoma. We studied 5 patients (4 adults and 1 child) with salmon-colored conjunctival lesions. One patient also had a history of abnormal bone marrow biopsy a year earlier with lymphoid aggregates involving 5% of the overall bone marrow. The conjunctival lesions of the 5 patients were biopsied. Histopathological diagnoses were consistent with conjunctival MALT lymphoma. Lymphoma and normal conjunctival cells were microdissected using laser capture microscopy or manual techniques. DNA was extracted and subjected to PCR amplification using H. pylori gene-specific primers from the urease B and vac/m2 gene. Cells from chronic conjunctivitis (normal lymphocytes), conjunctival human T-cell lymphotropic virus type-1/adult T-cell leukemia/lymphoma (HTLV- 1/ATL), and orbital B-cell lymphoma were also microdissected, processed and analyzed. PCR amplification and Southern blot hybridization demonstrated H. pylori DNA in the conjunctival MALT lymphoma cells of 4/5 cases. The negative case was the one with a history of abnormal bone marrow. In contrast, H. pylori gene was not detected in normal conjunctival cells from the cases of MALT lymphoma or the lymphocytes, ATL and orbital B-lymphoma cells from the controls. These data suggest that H. pylori may play a role in conjunctival MALT lymphoma.