Immortalised cell line

Immortalised cell line
apoptotic HeLa cell. Zeiss Merlin HR-SEM.
HeLa cells, an example of an immortalised cell line. DIC image, DNA stained with Hoechst 33258.
Anatomical terminology [edit on Wikidata ]

An immortalised cell line is a population of cells from a multicellular organism which would normally not proliferate indefinitely but, due to mutation, have evaded normal cellular senescence and instead can keep undergoing division. The cells can therefore be grown for prolonged periods in vitro. The mutations required for immortality can occur naturally or be intentionally induced for experimental purposes. Immortal cell lines are a very important tool for research into the biochemistry and cell biology of multicellular organisms. Immortalised cell lines have also found uses in biotechnology.

An immortalised cell line should not be confused with stem cells, which can also divide indefinitely, but form a normal part of the development of a multicellular organism.

Relation to natural biology and pathology

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There are various immortal cell lines. Some of them are normal cell lines (e.g. derived from stem cells). Other immortalised cell lines are the in vitro equivalent of cancerous cells. Cancer occurs when a somatic cell which normally cannot divide undergoes mutations which cause de-regulation of the normal cell cycle controls leading to uncontrolled proliferation. Immortalised cell lines have undergone similar mutations allowing a cell type which would normally not be able to divide to be proliferated in vitro. The origins of some immortal cell lines, for example HeLa human cells, are from naturally occurring cancers. HeLa, the first immortal human cell line on record to be successfully isolated and proliferated by a laboratory, was taken from Henrietta Lacks (without informed consent^[1]) in 1951 at Johns Hopkins Hospital in Baltimore, Maryland.

Role and uses

Immortalised cell lines are widely used as a simple model for more complex biological systems, for example for the analysis of the

Immortalised cell lines find use in biotechnology, where they are a cost-effective way of growing cells similar to those found in a multicellular organism in vitro. The cells are used for a wide variety of purposes, from testing toxicity of compounds or drugs to production of eukaryotic proteins.

Limitations

Changes from nonimmortal origins

While immortalised cell lines often originate from a well-known tissue type, they have undergone significant mutations to become immortal. This can alter the biology of the cell and must be taken into consideration in any analysis. Further, cell lines can change genetically over multiple passages, leading to phenotypic differences among isolates and potentially different experimental results depending on when and with what strain isolate an experiment is conducted.^[3]

Contamination with other cells

Many cell lines that are widely used for

There are several methods for generating immortalised cell lines:[5]

1. Isolation from a naturally occurring cancer. This is the original method for generating an immortalised cell line. Major examples include human HeLa, the line is derived from cervical cancer cells taken on February 8, 1951 from Henrietta Lacks, a 31-year-old African-American mother of five, who died of cancer on October 4, 1951.^[6]
2. Introduction of a viral gene that partially deregulates the cell cycle (e.g., the adenovirus type 5 E1 gene was used to immortalise the
   B lymphocytes by infection^[7]
   ).
3. Artificial expression of key proteins required for immortality, for example telomerase which prevents degradation of chromosome ends during DNA replication in eukaryotes. ^[8]
4. myeloma (B cell cancer) cell.^[9]

• 3T3 cells – a mouse fibroblast cell line derived from a spontaneous mutation in cultured mouse embryo tissue.
• A549 cells – derived from a cancer patient lung tumor.
• HeLa cells – a widely used human cell line isolated from cervical cancer patient Henrietta Lacks.
• HEK 293 cells – derived from human fetal cells.
• Huh7 cells – hepatocyte-derived carcinoma cell line
• T lymphocyte
  cell line isolated from a case of leukemia.
• North American opossum
  kidney cells
• Ptk2 cells – derived from male long-nosed potoroo
  epithelial kidney cells.
• Vero cells – a monkey kidney cell line that arose by spontaneous immortalisation.

See also

• Cellosaurus, knowledge base of cell lines
• IGRhCellID, database of cell lines
• List of breast cancer cell lines
• Conditionally Immortalised cells

References

External links

Wikimedia Commons has media related to Immortalised cell line.

• ATCC –
  American Type Culture Collection
• Cellosaurus – a knowledge resource on cell lines
• CellBank Australia – Australia's national not-for-profit cell line repository