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.
Reference:
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
Source-Medindia