Tissue Factor Pathway Inhibitor-2 may Protect Against Cervical Cancer
Cancer of the cervix is the second most common cancer to affect women all over the world. The HPV or Human Papilloma Virus is often implicated as a main cause of the cancer.
However, it has been suggested that HPV alone may not result in cervical cancer; other factors could also contribute to the development of the cancer. One such substance is Tissue factor pathway inhibitor-2 (TFPI-2). It is also called placental protein (PP5) or matrix-associated serine protease inhibitor (MSPI). It has earlier been shown to suppress tumor growth in cancers like choriocarcinoma, glioma, prostate cancer, pancreatic carcinoma and lung cancer.
Breakdown of extracellular matrix in the cervix is important for growth and spread of the cancer. It is thought that TFPI-2 inhibits the breakdown of extracellular matrix in the cervix and thus prevents the cancer.
In a recently published paper, some researchers tried to correlate the role of TFPI-2 in the development of cervical cancer. The study was carried out on 128 samples of the cervix obtained by biopsy, out of which 116 samples showed the presence of cancer.
The researchers observed that TFPI-2 was expressed only in the cytoplasm of the cervical tissues. Its expression was found to decrease as the stage of cancer increased and was least in the invasive stage of the cancer.
The expression of TFPI-2 was also lower in samples positive for HPV infection. Thus, TFPI-2 depletion could influence the progression of cancer in patients with HPV infection.
Reduced expression of TFPI-2 was also associated with a decrease in apoptosis. Apoptosis is the phenomenon of programmed cell death. Older cells normally undergo apoptosis. Failure of apoptosis can result in excessive proliferation of cells and cancer.
Downregulation of TFPI-2 was also associated with an increased expression of VEGF. VEGF helps blood vessels to grow and provides nutrition to the cancer cells, thus promoting cancer.
Thus, TFPI-2 may be considered as a tumor suppressor gene that inhibits progression of cervical cancer. It prevents breakdown of extracellular matrix. It also probably plays a role in apoptosis of cells and inhibits proliferation of blood vessels to prevent the development of cancer. Further studies are required in this context.
1. Zhang Q et al. Reduced expression of Tissue factor pathway inhibitor-2 contributes to apoptosis and angiogenesis in cervical cancer. Journal of Experimental & Clinical Cancer Research 2012, 31:1 doi:10.1186/1756-9966-31-1