KBM-7 cells are a

chronic myelogenous leukemia Chronic myelogenous leukemia (CML), also known as chronic myeloid leukemia, is a cancer of the white blood cells. It is a form of leukemia characterized by the increased and unregulated growth of myeloid cells in the bone marrow and the accumulat ...

(CML)

cell line 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 cell ...

used for biomedical research. Like all cancer cell lines, it is immortal and can divide indefinitely. A unique aspect of the KBM-7 cell line is that it is near-

haploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

, meaning it contains only one copy for most of its chromosomes. Human chromosomes are typically diploid, meaning that there are two copies of each chromosome.

Origin

KBM-7 cells were derived from a 39-year-old man with chronic myeloid leukemia in blast crisis. The original cell line contained both near

and hyperdiploid clones. Subsequent subcloning yielded a pure near-haploid cell line. Genome analysis has revealed that besides the disomic chromosome 8, a 30 megabase fragment of chromosome 15 is present in two copies. Like other CML cells lines (e.g.,

K562 K562 cells were the first human immortalised myelogenous leukemia cell line to be established. K562 cells are of the erythroleukemia type, and the cell line is derived from a 53-year-old female chronic myelogenous leukemia patient in blast crisis. ...

) KBM-7 cells are positive for the

Philadelphia chromosome The Philadelphia chromosome or Philadelphia translocation (Ph) is a specific genetic abnormality in chromosome 22 of leukemia cancer cells (particularly chronic myeloid leukemia (CML) cells). This chromosome is defective and unusually short becaus ...

harboring the BCR-ABL oncogenic fusion. KBM-7 cells have been reprogrammed to yield the

HAP1 Huntingtin-associated protein 1 (HAP1) is a protein which in humans is encoded by the ''HAP1'' gene. This protein was found to bind to the mutant huntingtin protein () in proportion to the number of glutamines present in the glutamine repeat regio ...

cell line which is also monosomic for chromosome 8.

Cultivation and applications

KBM-7 cells grow in suspension and are maintained in Iscove's Modified Dulbecco's Medium (IMDM) supplemented with 10% fetal bovine serum. They divide approximately every 24 hours. KBM-7 has found applications in a variety of genomic research studies; the cell line has been examined in gene silencing experiments, been reprogrammed to become a

stem cell In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can differentiate into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type o ...

line, and served as a test model for novel drug candidates.

Significance

One method of studying gene function involves "knocking out" the gene by inducing a mutation. This causes the resulting gene product to be nonfunctional, and researchers can then see how this effects the cell's function as a whole. Many gene editing procedures have very low efficiency, and often both copies of mammalian chromosomes must be knocked out in order to see a phenotypic effect. Having a near-haploid cell line such as KBM-7 greatly increases the efficiency of these studies because there is only one gene that must be knocked out.

References

{{reflist

External links

Cellosaurus entry for KBM-7
* * * * Human cell lines