Autotaxin (ATX) as a Marker for Breast Cancer

Breast cancer is the leading cause of cancer death in women worldwide. According to the GLOBOCAN 2018 worldwide estimates of cancer incidence and mortality, in 2018, about 2,088,849 new cases were diagnosed and approximately 626,679 women were predicted to die from the disease . It is the leading cause of cancer related mortality, representing15% of deaths per year worldwide .

Breast cancer is the most common malignancy in females in Egypt. It accounts for 32 % of cancer in women . Breast cancer in Egypt carries an unfavorable prognosis with 29% mortality and 3.7:1 incidence to mortality ratio .

Despite the rising incidence of breast cancer, the survival rates have improved in recent years due to the deep research in biological behavior of breast cancer . Although the current 5-year survival for primary breast cancer is relatively high (ranging from 80% to 92% in different populations) survival rates decrease to less than 25% when the disease becomes metastatic .These data support the need to develop more efficient strategies for preventive, intervention, evaluation of therapy, and prediction of prognosis .

Autotaxin (ATX) is a glycoprotein encoded by the ENPP2 (Ectonucleotide Pyrophosphatase/Phosphodiesterase 2) gene located on chromosome 8. Identical to lysophospholipase D, ATX plays a role in the synthesis of the bioactive lipid mediator lysophosphatidate (LPA) from lysophosphatidylcholine (LPC) .

LPA acts through specific G protein-coupled receptors (GPCRs) to promote cellular proliferation, migration, and survival . ATX expression was also reported higher in poorly differentiated tumors and, in independent studies, is correlated with invasiveness of cancer cells suggesting a higher metastatic potential of ATX-expressing tumors . ATX is generated from platelets, endothelial cells, fibroblasts, and adipocytes and specifically, ATX from adipocytes has an impact on plasma LPA level . Thus, adipocytes could be an important origin of ATX in tumors. Breast cancer is a human cancer that has adipocyte-rich stroma. Adipose tissue comprises 56% of non-lactating breast tissue, and 35% of lactating breast tissue . ATX-LPA signaling has been reported to be involved in angiogenesis, tumor cell invasion, and migration in breast cancer .

Increased ATX expression has also been reported in various forms of cancer, such as glioblastoma, hepatocellular and thyroid carcinomas, pancreatic and hematological cancers. A large number of evidence indicate that ATX-LPA is associated with chemotherapy resistance of cancer, and in breast cancer, ATX can reverse cell apoptosis.

In a mouse model, α-bromomethylene phosphonate LPA (BrP-LPA), a dual ATX and pan-LPAR( Lysophosphatidic acid receptor ) inhibitor, inhibited migration and invasion of breast cancer cell lines and suppressed primary tumor and angiogenesis in a mouse xenograft study . Since tumor and stromal cells in breast cancer express ATX-LPA signaling-related proteins, inhibition of the ATX-LPA axis could be of therapeutic importance .Therefore, further study ATX as a tumor marker in breast cancer is required.

Eligibility Criteria:
Inclusion Criteria:

* The study will be conducted on one hundred female individuals; 80 newly diagnosed breast cancer patients before any treatment or surgical intervention and 20 apparently normal female individuals.

Exclusion Criteria:

* Patients with any other type of malignant or benign tumors, renal failure, cardiovascular diseases and liver cirrhosis were excluded from our study.
* Past history of chemotherapy or surgical treatment of any malignancy.
* Inflammatory diseases (e.g.bronchitis) or autoimmune diseases (e.g.rheumatoid arthritis).