HOXA5

A gene on chromosome 7p15.2 that encodes a DNA-binding transcription factor, which provides cells with specific positional identities along the anterior-posterior axis during embryonic development and is involved in gene expression, morphogenesis and differentiation.

Molecular pathology
HOX5A methylation may result in a loss of expression of the protein product—which normally upregulates p53, the tumour suppressor—thus indirectly playing a role in cancer development.

Mentioned in ?

KDM5B

References in periodicals archive ?

Starting with 26 transcription factors identified as likely candidates, they eventually came down to just five (RUNX1, ERG, LCOR, HOXA5 and HOXA9) that were both necessary and sufficient for creating blood stem cells.

New technique raises possibility of making all types of blood cells

Regulation of angiogenesis through a microRNA (miR-130a) that downregulates antiangiogenic homeobox genes GAX and HOXA5.

The role of MicroRNAs in human diseases

Compromised HOXA5 function can limit p53 expression in human breast tumours.

Characterization and role of p53 family members in the symbiont-induced morphogenesis of the Euprymna scolopes light organ

Of tumor samples taken from 30 women with breast cancer, 20 were devoid of the protein, called HOXA5, says study coauthor Saraswati Sukumar, a molecular biologist at the Johns Hopkins Medical Institutions in Baltimore.

To ascertain whether HOXA5 plays a vital role in activating p53, Sukumar and her colleagues infused either functional or defective HOXA5 genes into breasttumor cells in laboratory dishes.

Further experimentation suggested a mechanism by which the HOXA5 gene might come to be disabled in cancer patients.

While methylation is a common occurrence in DNA throughout the body, the promoter DNA next to the HOXA5 gene "is normally not a methylated region," says Sukumar.

Meanwhile, none of the breast cells from 10 healthy women showed a methylated promoter for HOXA5, she says.

By demethylating HOXA5 promoter DNA, scientists might be able to fight breast cancer by activating p53 in patients, she says.