Preclinical research models of cancer, such as human tumor xenografts, murine tumor homografts, cell line models and 3D organoid models, are extensively used in research and development for oncology studies. Since these tumor models are used for a wide spectrum of research applications, they are often utilized globally but the cell lines which are used to establish these models of cancer studies have the risk of becoming contaminated and misidentified due to cross contamination scenarios. Among cancer cell lines, the prevalence of contamination is majorly for HeLa cells, followed by T24 bladder cancer cells.
Studies with error-prone conclusions are rampantly practiced and globally, an annual $700 million is predicted to be invested in studies that employs contaminated and misidentified cell lines. Cell line misidentification contribute heavily to poor reproducibility followed by tarnishing researcher reputation. Thus it becomes very important for scientists and researchers to administer protocols of routine assays for quality control of their cell cultures and validate the identification of cells before establishing a model for implementation. Thus, the need for cell line authentication becomes a crucial standpoint for cancer researchers.
Let us get a brief idea of two major genome-based assays for cell line authentication: short tandem repeat (STR) and single nucleotide polymorphism (SNP) assay.
What are Short Tandem Repeat (STR) Assays?
Short tandem repeat assays utilize the concept of using primers that recognize repeated DNA segments which are 2–6 base pair long. This technique has been very valuable in authenticating human cell lines as the number of nucleotide repeats at each genomic site varies within the population of humans. This genome-based can therefore track identification of human tumors by genotyping tumors that are either derived from patient xenografts or cell lines. The ATCC (American Tissue Culture Collection) has published guidelines for this technique to standardize STR analysis for the purpose of human cell line authentication.
Even though STR analysis has been used by a lot of research labs for cell line authentication, inadequate accuracy of the assay, in case of close genetic relationships, remains as the major limitation. Therefore, STR profiling is not suitable for murine or mus tumors that originate from limited strains of inbred animals as they lack unique genetic markers to individually distinguish or identify. STR profiling is also not a suitable choice for authenticating different cell lineage tumors from the same human donor.
What are Single Nucleotide Polymorphism (SNP) Assays?
Due to the limitation of STR analysis, researchers came up with improved method of cell line authentication in the form of single nucleotide polymorphism (SNP). While STR analysis depended on a bunch of nucleotide repeats, SNP analysis depends on variation in single DNA nucleotides among individuals. Recent advances in technologies for high throughput sequencing have brought about enhanced cost-efficiency and technical accuracy in the domain of SNP profiling-based authentication.
SNP analysis can authenticate species-specific tumor models and even mismatch repair deficient human cancer cell lines, that are difficult to authenticate using STR analysis. Thus SNPs can bypass the limitations of STR profiling for cell line authentication and also help in gender determination, mycoplasma contamination, viral infection etc.
When to Authenticate Cell Lines?
Cell line authentication is important in the following cases specifically: When cell lines are received from unreliable sources, after 10-12 passages, and when a researcher wants to validate for oublication purposes. Nowadays, this problem has been addressed quite a lot and several scientific journals and funding agencies are not leaving this to fate! There should always be a curious doubt on the mentioned factor and every researcher should ensure that the cell lines they are working with, are perfectly authenticated.
Cell cultures in cancer research, whether they come as 2D monolayer cultures or improved 3D organoid models, have been the fundamental aspect of pre-clinical studies. In this aspect, cell line authentication is the key to producing reliable and reproducible data for publication as often due to cross contamination and misidentification issues, research data lack efficacy and reliability. Therefore, cancer researchers and oncologists should focus on cell line authentication as much as pay attention to higher cell viability and cell contamination prevention with the help of good cell culture practices. At Kosheeka, we guarantee authenticated cancer cell lines for scientists who believe in being an essential part of the global healthcare research. Contact us at email@example.com today to procure your required cancer cell lines and primary cells.