Changes in the STR profile of cells in the process of obtaining a stable cell line

Background. Loss of heterozygosity, loss of the Y chromosome, and other types of genetic alterations are characteristic of tumor cell lines. Standard methods for detecting such changes are effortand time-consuming, and costly. Routine laboratory analysis of the authenticity and absence of intraspecific cell lines contamination using short tandem repeats (STR) profiling also allows for monitoring some genetic changes that cells undergo during the life cycle. The location of some potential STR loci is close to regulatory oncogenic loci, so many researchers note the prognostic and diagnostic utility of using STR profiling at the primary stage of genetic characterization of cell lines.

Aim. Control of cell identity and genetic variability during the establishment of a stable cell line.

Materials and methods. Profiling was carried out for primary cell cultures, for xenografts samples mel Lap nude, mel Kas nude and mel Pet nude, as well as during cell culture at 8^th, 10^th, 20^th passages of the mel Lap, at 10th, 20^th passages of the mel Kas and at 5^th, 10^th, 20^th, 49^th passages of the mel Pet, as well as after defrosting archived samples.

Results. For the mel Lap culture, by passage 8, a loss of heterozygosity was observed at the SE33 locus, and then the genetic profile remained stable. By passage 10, mel Kas cells lost heterozygosity for two loci SE33 and D6S1043, and in the CSF1PO locus at passage 0, amplification of three alleles was observed – 11, 12, 13. Subsequently, the culture maintained a stable STR profile. By the 5th passage, the mel Pet cell culture lost heterozygosity for almost all the studied loci, but then its STR profile remained unchanged throughout 49 passages and in the xenograft material.

Conclusion. The STR profiling method allows not only to monitor genetic stability in a cell line and the absence of intraspecific contamination during cultivation, but also, being fast and cheap, can be used as an additional primary test for significant genetic changes in cells.

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