Cancerous cell lines alter their genomic organization and karyotype with increased passage number: a cytogenetic study

Purpose: The limited use of mammals in human health related scientific research has led to the development of new research strategies like cell culture techniques. Commercially available cancerous cell lines that are well characterized by cytogenetics and biochemical markers allow comparison of results among different laboratories. However, as these cell lines tend to be maintained in culture over long periods of time, mutations can occur that may change characteristics and responses of cell lines that have initially been identified or non-existed at earlier passages. Here we cytogenetically investigated the chromosomal rearrangements in repeated cultures of six different cell lines over continuous passages. Method: MCF7, HCT116, A549, SHSY5Y, HEPG2, and NIH3T3 cell lines were cultured in DMEM containing 10% FBS and 1% penicillin-streptomycin. GTG banding procedure was used for the analysis of metaphase chromosomes, at least 20 metaphases were analyzed per cell line. Results: We found chromosome number variations and structural changes in the all examined cell cultures as the passage numbers increase. Conclusion: Cell lines have long been used in research to test drugs, to delineate molecular mechanisms, to understand the environmental effects and so on. The most important feature of a cell line is its genotype and karyotype similarities with their host organism. Cancer Cell lines, possess genomic/chromosomal instability that also lead them to change their phenotype along with their karyotype from one passage to next. Therefore, it is always best to verify karyotype before employing a specific cell line in a research project. Amaç: İnsan sağlığına ilişkin bilimsel araştırmalarda memelilerin sınırlı kullanımı yeni araştırma stratejilerinin geliştirilmesine yol açmıştır. Bunlardan birisi memeli hücre kültürü tekniğidir. Piyasada bulunan, sitogenetik ve biyokimyasal belirteçlerle iyi karakterize edilmiş kanser hücre hatları farklı laboratuvarlar arasındaki sonuçların karşılaştırılmasına olanak sağlar. Bununla birlikte, bu hücre dizileri, kültürde uzun bir süre muhafaza edildiklerinden, önceki pasajlarda tanımlanmış veya saptanmamış, hücre hatlarının özelliklerini ve ajanlara karşı tepkilerini değiştirebilecek mutasyonlar meydana gelebilir. Burada sitogenetik olarak, altı farklı hücre hattının tekrarlanan hücre kültürlerinde yeni kromozomal düzenlenmeleri araştırdık. Metod: MCF7, HCT116, A549, SHSY5Y, HEPG2 ve NIH3T3 hücre hatları, %10 FBS ve %1 penisilin-str