Although maspin is believed to reduce the formation, development, and spread of tumors in several aggressive cancers (breast, ovarian, and head and neck cancers), it has been challenging to utilize this information and predict how cancer patients will fare with its use; the presence of maspin has been associated with both good and bad prognoses. The cause of this irregularity was considered to be based on the location of maspin within the cell, whether in the nucleus or in the cytoplasm, according to Drs. John Lewis and Ann Chambers, and their colleagues at Lawson Health Research Institute.
To assess the effects of maspin on tumor growth and development, the team introduced 2 forms of maspin into 2 aggressive types of cancer cells: a highly invasive head and neck cancer, and a breast cancer known to spread to the lymph nodes and the lungs. One form of maspin went into the cells’ nucleus and one form was blocked from the nucleus.
Results of the study revealed, when maspin was present in the cancer cells’ nucleus, the incidence of metastasis was lowered (75% to 40%). When maspin was not established in the nucleus, its ability to halt growth was reversed and cancer cells were far more likely to spread. Therefore, cancer cells' behavior, disease aggressiveness, and patient outcomes appear to be influenced considerably by the location of maspin within the cell.