Gene expression (quantitative assessment) of transcription factors
p53 (also known as protein 53 or tumor protein 53 ), is a tumor suppressor protein that in humans is encoded by the TP53 gene. p53 is crucial in multicellular organisms , where it regulates the cell cycle and, thus, functions as a tumor suppressor that is involved in preventing cancer. p53 has many mechanisms of anticancer function, and plays a role in apoptosis, genomic stability, and inhibition of angiogenesis. If the P53 gene is deleted or mutated, tumor suppression is severely reduced.
Homeobox protein Hox-B13 is a protein that in humans is encoded by the HOXB13 gene . This gene encodes a transcription factor that belongs to the homeobox gene family. Genes of this family are highly conserved among vertebrates and essential for vertebrate embryonic development.
The HOXB13:IL17BR index has been identified to predict clinical outcome in the setting of adjuvant tamoxifen monotherapy of breast cancer. Further studies have shown that HOXB13 in particular can indicate benefit of prolonged tamoxifen treatment. Patients with high-expressing HOXB13 tumors did not benefit from prolonged treatment, suggesting that HOXB13 might be involved in tamoxifen resistance. No studies have been made regarding the HOXB13 protein levels in breast cancer. Tamoxifen-treated patients with estrogen receptor-positive tumors expressing none or low levels of HOXB13 had a clear benefit from tamoxifen in terms of longer distant recurrence-free survival. A high HOXB13 expression was associated with decreased benefit from tamoxifen, which indicates that HOXB13 protein level may be used as a predictive marker for tamoxifen treatment.
PAX 8 is a transcription factor that is essential for embryonic development of the kidney and thyroid. It may also have a role in tumor development in these organs.