General Methods to Immortalize Primary Cells

Author: Terry Hess

Primary cells provide extremely accurate information and relevant results in research, serving as the most ideal cell models for a vast variety of research, from fundamental cell biology and physiology, developmental biology, disease mechanisms, to drug screening and therapeutics development. However, primary cells do not grow indefinitely in culture and are very difficult to culture. Therefore, researchers tend to use immortalized cells for their research program.

The immortalized cells enable researchers to use the same consistent material throughout a research project, without having to establish new cultures, because these immortalized cells have an extended life span and maintain the genotype and phenotypic markers of the source tissue. Utilizing a cell immortalization service helps researchers avoid this issue and offers them the possibility of an almost limitless supply of cells that can be used throughout the duration of an entire research project.

The successful immortalization of various primary cells is implemented by using different genes and agents. Cell immortalization can be done in many ways; and custom service is available in the market to help generate immortalized cell lines. There are many methods of mammalian cell immortalization within culture environments. A few of these methods are listed below:

hTERT Expression

hTERT alone can immortalize cells without causing cancer-associated changes or altering phenotypic properties. Primary human cells that have so far been established by the forced expression of hTERT alone include fibroblasts, retinal pigmented epithelial cells, endothelial cells, oesophageal squamous cells, mammary epithelial cells, keratinocytes, osteoblasts, and Nestin-positive cells of the pancreas.

A major obstacle to the immortalization of primary human cells and the establishment of human cell lines is telomere-controlled senescence. Telomere-controlled senescence is caused by the shortening of telomeres that occurs each time somatic human cells divide. But researchers have shown that the transfer of an exogenous hTERT cDNA, encoding the catalytic subunit of human telomerase, can be used to prevent telomere shortening, overcome telomere-controlled senescence, and immortalize primary human cells.

Viral Transformation

Viral transformation method is another way of bypassing cellular senescence. The most commonly used and the best understood of this class of viral genes is Simian Virus 40 large T antigen (SV40). SV40 Large T antigen binds to a number of proteins ( most important are p53 and Rb) which, when functioning normally, are negative regulators of cell division. Similarly, using siRNA to inactive p53 and/or Rb can also initiate unlimited cellular life span. Other oncogenes include c-Myc, Ras and HPV 16 E6/E7 and their introduction, likewise, can efficiently immortalize primary cells.Viral genes, including Epstein-Barr virus (EBV) and Simian virus 40 (SV40) T antigen can induce immortalization. Viral genes achieve immortalization by inactivating the tumor suppressor genes that put cells into a replicative senescent state.

Inactivation of Tumor Suppression Genes

Recent discoveries have found that co-expression of hTERT catalytic subunit combined with p53 or RB siRNA, can successfully immortalize human ovarian epithelial cells. At the same time, overexpression of Ras or Myc T58A mutants have also been found to be able to immortalize some primary cell types. This method allows a more authentic cell model with a more defined genetic background.

Custom Cell Immortalization Services

Creative Bioarray can provide custom cell immortalization services. With years of experience in cell immortalization, the company is now able to successfully immortalize cells from human, mouse, bovine and dog, using different immortalizing agents or genes. The custom immortalization service can significantly extend replicative capacity of your target cells, which helps saves lab time and money.

Article Source: http://www.articlesbase.com/cancer-articles/general-methods-to-immortalize-primary-cells-7224331.html
About the Author
Creative Bioarray a leading commercial biospecimen CRO, supplying service of the immortalization of cell. Our scientists are also researching over different animal cell and discover some quality tissues, antibody that is very helpful for medical industry.