oa Application of PCC and M-FISH assays to detect biomarkers-and stage specificity-of cancer of different origins and to improve cancer therapy regimens

Background: Cytogenetics of solid tumors in general is negatively affected by culturing artifacts such as preferential clonal expansion and introduction of chromosomal rearrangements, thus making it difficult to discriminate between primary changes and secondary events. Considering that chromosomal instability is a hallmark of cancer even at the precursor cancer level, it is of a great importance to devise a method of comprehensive chromosome analysis of cancer and cancer precursor cells that can bypass culturing problems as much as possible and that can provide informative karyograms of primary tumors at non-mitosis stages of the cell cycle. Consequently, we have developed a novel approach using chemically induced premature chromosome condensation (PCC) method and combined it with the technique of whole genome chromosome painting assay (M-FISH), in which chromosomal constitution of cancer cells could be detected independent of mitosis and without culture artifact within just three hours after receiving the biopsies. Objectives: 1. To perform karyotype analysis; 2. To define stage specificity; 3. To detect hall-mark(s) of cancer of different origins; 4. To improve therapy regimen by elucidating sensitivity of tumors and patients' lymphocytes to radiation and/or cytostatic drugs. Methods: Chemically-induced PCC method was applied on primary tumors (such as, cervical-, head and neck-, breast- and prostate-cancer) to generate metaphases. Afterwards, these preparations underwent M-FISH. Results: This unique/novel combined assay can give for the first time the possibility to assess genetic instability by detecting spontaneously occurring chromosomal instability (structural and numerical) in different types of primary tumors, as well as adjacent normal cells. It may open up the possibility to detect biomarker(s) for specific type of tumors, that can be used as screening tests. Furthermore, the sensitivity of specific types of tumors as well as patient's normal lymphocytes to cytostatic drugs and/or radiation can be determined. Conclusion: The unique combined state of the art assay we developed can lead to detect biomarker(s) for specific type of cancer. Moreover, for the first time therapy regimen can be individually designed based upon detecting tumors as well as patient's lymphocytes sensitivity.