PTP1B promotes the malignancy of ovarian cancer cells in a JNK-dependent mechanism

Ovarian cancer is the leading cause of death from gynecological malignancies in women. Diagnosis at the early stage remains challenging and efficient treatment is still highly needed. The development and progression of this cancer is associated with many genetic and epigenetic changes, representing the dysregulation of a highly complex signaling network. Previous studies found that protein-tyrosine phosphatase 1 B (PTP1B) was aberrantly expressed in many types of ovarian cancer cells. The exact role of this protein, however, remains controversial. We found that PTP1B was highly expressed in several ovarian carcinoma cell lines. Changing its expression level strongly affected the malignancy phenotypes of the cultured cancer cells and growth of tumors in nude mice. Further analysis at the molecular level found that overexpression of PTP1B activated the JNK (c-Jun N-terminal kinase) signaling pathway and impacted a set of factors involved in cancer metastasis. Overall, our study suggested that overexpression of PTP1B could be a driving factor in the tumorigenesis and progression of ovarian cancer and restoring the normal expression level of this signaling molecule may represent a promising strategy in treating this disease.