[Individual sensitivity to the mutagenic agents in patients with larynx cancer].

Patients with different cancers, induced mostly by numerous mutagenic factors, present increased genetic susceptibility to mutagenic agents known as "hidden chromosomal instability". This type of genetic instability can be detected in vitro after treating chromosomes with clastogenic substances, for example by using "bleomycine test". The purpouse of our study was to evaluate a hidden chromosome instability in patients with squamous cell carcinoma of larynx (SCCL) and to establish correlations between genetic results and both histological grade of the tumor and clinical progression of disease.

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.

Analysis of adaptive response to bleomycin and mitomycin C.

Genetic instability resulting from the disturbances in various mechanisms of DNA-repair is the characteristic feature of cancer cells. One of the possibilities to evaluate the effectiveness of DNA-repair system is the adaptive response (AR) analysis. The AR is a phenomenon by which cells exposed to low, non-genotoxic doses of a mutagen become significantly resistant to a subsequent higher dose of the same or another genotoxic agent.