I understand that normal breast cells have regulated ER, PR, and HER2 expression. So, ER and PR are typically expressed in these cells, regulating their growth with pregnancy and lactation cycles. Based on this information, normal-like cancers are those which express ER and PR. This is how I understand it. So, these cancers are responsive to hormonal therapy. The TNBCs are the ones that are more deviated from normal and are the ones that we try to find biomarkers for them which is still challenging. For more details, you can refer to this link:

https://www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-hormone-receptor-status.html

Hello Juthathip Jurutha

You may make use of biomarkers like basal cytokeratins such as CK5/6, CK14, CK17 and EGFR. These IHC markers will help you to differentiate between normal mammary cell and normal-like (Triple Negative breast cancer cell).

Please refer to the list of references I have attached below.

https://www.pathologyoutlines.com/topic/breastmalignanttripleneg.html

https://aacrjournals.org/clincancerres/article/13/15/4429/194334/Triple-Negative-Breast-Cancer-Clinical-Features

https://www.thieme-connect.com/products/ejournals/pdf/10.4103/0974-2727.163129.pdf

Best.

The expression of these three receptors in the normal gland is totally physiologic (normal) since each of them has a role in the development of the gland during puberty and pregnancy, ER is responsible for the elongation of the milk canals, PR is responsible for ductal side branching and alveologenesis and HER2 promotes cell growth and proliferation. When everything is under control the mammary glad grows normally but when there is excessive receptor stimulation, the proliferation becomes malignant favoring a phenomenon of tumorigenesis.

Identifying the existence of these three as well as the Ki67 which a proliferation index helps :

1- classifying the tumor into molecular subtypes (luminal a, luminal b, her2 positive and triple negative).

2- decide what kind of therapy the patient undergoes depending on the marker expressed ( selective estrogen receptor modulators or degradors in case the tumor is ER+ , trastuzumab or lapatinib in case only HER2 is expressed, cytotoxic therapy for triple negative because we have no molecular markers to target ).

3 - they are markers of prognosis and response to therapy.

Other biomarkers might be used in the identification of the histological type in case of difficulties such as:

1- distinguishing between benign and malignant proliferation

2- distinguishing between ductal and lobular carcinomas

3- telling if the mammary gland is the origin of a metastatic tumor

For more information about the significance of these markers in breast cancer I suggest this article

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4127609/

I hope you find it helpful.

Hi, which of the given proteins are best expressed by HELA cells, MET or HER2?