Cystatin SN, belonging to the type 2
cystatin superfamily, is widely expressed and distributed in mammals.
Cystatin SN is involved in
inflammation, cell cycle, cellular senescence,
tumorigenesis, and
metastasis.
Cystatin SN is also known to participate in signaling pathways like Wnt signaling pathway, GSK3 signaling pathway, AKT signaling pathway, and
IL-6 signaling pathway.
Cystatin SN was found to be highly expressed in peritumoral normal tissues in
esophageal squamous cell carcinoma (ESCC); however, low
cystatin SN expression was found in ESCC
cancer tissues. Conversely, in other
cancer types such as
lung cancer,
breast cancer,
gastric cancer,
pancreatic cancer, and
colorectal cancer, high
cystatin SN expression in
cancer tissues but low
cystatin SN expression in peritumoral normal tissues was found. Survival analyses showed that high
cystatin SN expression benefited ESCC patients but did harm to other types of
cancer patients. Univariate and multivariate analyses indicated that
cystatin SN possibly acts as a marker for
cancer prognosis. Here, we provide a brief introduction about the role of
cystatin SN in
cancer and discuss the different prognostic effects of
cystatin SN on different
tumors.
Cystatin SN might be a potential marker for
cancer prognosis and a target for
cancer therapy.