Laryngeal tuberculosis.
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Acetylcysteine↗
Biomedical subjects
Tomasz Zatonski
Publications and source records attributed to Tomasz Zatonski.
Expression of c-myc oncoprotein in laryngeal squamous cell carcinoma.
OBJECTIVE: c-myc seems to play a pivotal role in normal growth and development as well in cellular transformation and carcinogenesis. Overexpression of the c-myc oncogene has been observed in many hematopoetic and solid tumors. The role of c-myc protein in squamous cell carcinoma of the head and neck in general and laryngeal squamous cell carcinomas (LSCCs) in particular is far from clear. The aim of this study was to evaluate the relations between the level of c-myc protein in LSCCs and the clinicopathological data of patients, DNA ploidy and the SG2M phase index (PI). MATERIAL AND METHODS: The c-myc protein level was evaluated immunohistochemically in tumor specimens from 50 patients with LSCC. The DNA index and SG2M PI were determined by means of flow cytometry. RESULTS: We found c-myc protein in 34 (68%) tumors. Expression of c-myc protein was demonstrated to be frequent in nonmetastatic cases (p = 0.016). There was no association between c-myc protein level and age, primary tumor size, histological grading or type of cancer. In 13 (26%) cases we observed DNA aneuploid tumors. The mean value of the SG2M PI was 22.5%. Expression of c-myc protein was not related to SG2M PI or DNA ploidy. CONCLUSIONS: We have shown that c-myc oncoprotein may be involved in the genesis of LSCC. Our findings suggest that the detectability of c-myc protein is associated with a lower metastatic potential. The c-myc oncogene is probably not as important in laryngeal cancers compared to other cancers. Further investigations must be performed to establish the value of predicting nodal metastases in LSCC.
Aneuploidy↗
Correlation among loss of heterozygosity, promoter methylation and protein expression of MLH1 in larynx cancer.
Extensive molecular studies in development of the squamous cell carcinoma of larynx (SCCL) indicated the involvement of a variety of genes including the MLH1. To search for possible mechanism leading to MLH1 silencing in SCCL we studied LOH and promoter methylation in a homogeneous set of 62 larynx cancers. Then we evaluated immunohistochemically the MLH1 expression for 51 tumor specimens. Further, the results were correlated with microsatellite instability and subsequently with the clinical course of the disease. LOH at the MLH1 locus and aberrant methylation of its promoter were found in 47.9 and in 22.6% of tumors, respectively. A decreased expression was observed in 27.5% of the cases. MSI analysis of tumor DNA showed a microsatellite stable phenotype in 59 cases (95.2%). From our study it can be concluded that: i) molecular alterations of MLH1 play an important role in SSCL development, ii) both LOH and aberrant methylation contribute to the MLH1 inactivation in SCCL and are associated with a less advanced stage of differentiation of larynx tumors, iii) MLH1 inactivation does not lead to MSI in larynx cancer and MSI may not contribute to the development of SCCL.
Adaptor Proteins, Signal Transducing↗
Expression of collagenase-1 (MMP-1), collagenase-3 (MMP-13) and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in laryngeal squamous cell carcinomas.
Matrix metalloproteinases (MMPs) that have a proteolytic activity against the components of extracellular matrix (ECM) play an important role in the invasive and metastatic spread of tumors. The role of MMPs and tissue inhibitors of MMPs (TIMPs) in laryngeal squamous cell carcinoma (LSCC) has not been elucidated sufficiently. The aim of the present study was to evaluate the correlation between the expression of collagenase-1 (MMP-1), collagenase-3 (MMP-13) and TIMP-1, as well as the clinicopathological features of LSCCs. The expression of collagenases and TIMP-1 was examined immunohistochemically in 50 cases of surgically obtained specimens of primary LSCCs. Analyses indicated that LSCC cells as well as stromal cells expressed MMP-1, MMP-13 and TIMP-1 immunostaining. Overexpression of TIMP-1 occurred more frequently in non-metastasizing cases (P=0.009). TIMP-1 and MMP-1 staining correlated significantly with the histologic type of LSCC. The keratinizing type of carcinomas exhibited higher TIMP-1 protein expression than the nonkeratinizing variety (P=0.01). TIMP-1 staining was associated with the grade of differentiation, since it was found predominantly in well and moderately differentiated carcinomas (P=0.04). The findings confirm that expression of analyzed MMPs and TIMP-1 is characteristic of LSCC and that these enzymes contribute to the progression of tumors. TIMP-1 upregulation might exhibit lower metastatic potential in LSCCs and is linked rather with an early stage of tumor progression. It seems also that TIMP-1 expression is dependent on the grade of differentiation.
Adult↗