Folate Receptor Alpha (FOLR1) is a protein on cell surfaces that binds to folate, a B vitamin essential for cellular processes like growth and DNA synthesis. The connection between FOLR1 and ovarian cancer is important for diagnosis and treatment. Identifying targets like FOLR1 can help develop more effective approaches for this challenging disease.
Understanding FOLR1
FOLR1, encoded by the FOLR1 gene, primarily transports folate into cells. Folate is a nutrient required for metabolic activities, including DNA creation and cell division, making it important for rapidly dividing cells. In healthy tissues, FOLR1 is found at low levels on cells in organs like the kidneys, lungs, and placenta, helping them acquire folate. Cancer cells, however, have a higher demand for folate to fuel their growth.
FOLR1’s Role in Ovarian Cancer Development
FOLR1 is found in elevated amounts on the surface of ovarian cancer cells, especially in epithelial ovarian cancer, which accounts for most cases. Studies show FOLR1 is overexpressed in 80% to 90% of these cancers. This increased presence allows cancer cells to absorb more folate, supporting their rapid division and aggressive growth.
FOLR1 overexpression actively contributes to cancer progression. By absorbing folate, cancer cells sustain their high metabolic rate and continuous proliferation. Elevated FOLR1 levels are also associated with more aggressive disease and a less favorable patient outlook.
The protein’s involvement extends beyond nutrient uptake. It can influence signaling pathways that promote cell survival and resistance to cell death, making ovarian cancer cells more robust. FOLR1 overexpression may also play a role in metastasis, the spread of cancer cells to other body parts.
FOLR1 as a Target for Diagnosis and Treatment
The overexpression of FOLR1 on ovarian cancer cells offers a unique opportunity for medical intervention. Detecting high levels of FOLR1 on tumor cells can serve as a diagnostic indicator. For instance, immunohistochemistry, a technique using antibodies to identify specific proteins in tissue samples, can reveal FOLR1 presence and amount on biopsy cells, aiding in classification and prognostic assessment of certain ovarian cancer types.
FOLR1’s distinct presence on malignant cells, with less prevalence on healthy tissues, makes it an attractive target for therapies designed to specifically attack cancer cells. This has led to “folate-targeted” or “FOLR1-targeted” therapies, such as mirvetuximab soravtansine, an antibody-drug conjugate.
Mirvetuximab soravtansine binds to the FOLR1 protein on ovarian cancer cells. Once bound, the drug is internalized, delivering a potent chemotherapy agent directly inside. This targeted delivery minimizes damage to healthy cells with low or no FOLR1 expression, potentially reducing side effects compared to traditional chemotherapy.
Current Research and Future Directions
Ongoing research explores FOLR1’s full potential in ovarian cancer management. Scientists are investigating new FOLR1-targeted therapies, including next-generation antibody-drug conjugates and other innovative drug designs, currently in clinical trials. These studies aim to improve treatment effectiveness and patient outcomes.
Beyond therapy, FOLR1 is also being explored as a target for imaging agents. Such agents could help visualize ovarian tumors more clearly, assisting in diagnosis, staging, and monitoring treatment response. Research also examines combining FOLR1 inhibitors with other treatments for synergistic effects. The focus on FOLR1 continues to enhance care for individuals with ovarian cancer.