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BREAST CANCER 
Breast cancer affects more than 1.2 million patients in the US
each year and is the second most common cancer in women, with more than 194,000
new patients diagnosed every year.
Approved therapies used in the treatment of breast cancer include
chemotherapies, hormonal therapies and biological therapies. However, these
treatments are effective in only 10 to 60% of patients.
Chemotherapies come with significant adverse side effects and toxicity profiles
and many patients' tumors are not ideal candidates for current biological or
hormonal therapies, leaving few options for patients with advanced disease.
Prolactin is a peptide hormone associated with mammary gland development and
lactation and development of the ovaries. Prolactin is synthesized and secreted
mainly by lactotroph cells in the anterior pituitary gland. When prolactin binds
to the prolactin receptor, it causes it to dimerize with another receptor and
activate the JAK-STAT intracellular pathway. This pathway plays a central role
in cell fate decisions, such as cell proliferation, differentiation and
apoptosis (programmed cell death).
Prolanta is a variant of normal human prolactin in which the
single glycine amino acid at position 129 has been substituted with arginine.
With this modification of the PRL molecule, Prolanta blocks prolactin's
action by preventing it from binding to the prolactin receptor,
thereby inhibiting various signaling pathways involved in tumor cell growth.
Therefore, Prolanta serves as a novel candidate for the development of a
targeted therapy for breast cancer.
Recent evidence suggests a strong link between prolactin and
breast cancer in that inhibition of the prolactin receptor inhibits breast
cancer cell growth and transgenic mice that over express hPRL have a higher
incidence of breast cancer.
Experimental data (in vitro and
in vivo) generated in the
laboratory of our Principal Scientist, Dr. Wen Chen, demonstrate that Prolanta
has anti-tumor activity not only as a single agent, but also in combination with
other cancer therapies, including Herceptin and tamoxifen.
Prolanta is a variant of normal human prolactin.
The single glycine amino acid at position 129 has been substituted with arginine
(red).
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