Cancer is one of the most common diseases, with high morbidity and mortality rates. Large‑scale efforts have been made to understand the pathogenesis of the disease, particularly in the advanced stages, in order to develop effective therapeutic approaches.
Hepatocyte growth factor activator inhibitor type-1 (HAI-1), also known as
serine protease inhibitor Kunitz type 1, inhibits the activity of several
trypsin-like
serine proteases. In particular, HAI-1 suppresses
hepatocyte growth factor (
HGF) activator and
matriptase, resulting in subsequent inhibition of HGF/
scatter factor and macrophage‑stimulating
protein (MSP). HGF and MSP are involved in
cancer development and progression, via the receptors
Met receptor tyrosine kinase (RTK) and Ron RTK, respectively. Therefore, HAI-1-mediated downregulation of HGF and MSP signaling may suppress
tumorigenesis and progression in certain types of
cancers. Abnormal HAI-1 expression levels have been observed in various types of human
cancer. The exact function of HAI-1 in
cancer pathogenesis, however, has not been fully elucidated. In this review, the focus is on the potential impact of aberrant HAI-1 expression levels on
tumorigenesis and progression, the underlying mechanisms, and areas that require further investigation to clarify the precise role of HAI-1 in
cancer.