Capability of Platelet Factor ۴ to Induce Apoptosis in the Cancerous Cell Lines in Vitro

Background and Aims: Platelet factor ۴ (PF۴) or CXCL۴ is a member of CXC chemokine family which is stored in alpha granules of platelets. The main function known for PF۴ is angiostasis which may contribute to prevent tumor metastasis. This feature is mediated by CXCR۳ on the endothelial cells. Our principal aim was to study the apoptosis induction in three cell lines treated with PF۴ and obtained from human platelet concentrates. Materials and Methods: We evaluated the apoptotic effect of platelet-derived PF۴ on the U۲۶۶B۱ and K۵۶۲ cell lines expressing CXCR۳, compared with Daudi as a CXCR۳-negative cell line. PF۴ was purified from human platelet concentrates by immunoaffinity chromatography and was concentrated. The quantity and molecular weight of the obtained PF۴ was determined by enzyme-linked immunosorbent assay and sodium dodecyl sulfate polyacrylamide gel electrophoresis methods respectively. Cell lines were treated for ۷۲ and ۹۶ h with ۹۰ μg/ml of PF۴. Apoptosis was assayed by using CD۹۵, WST-۱, active caspase-۳, and cell count. Results: Platelet-derived PF۴ was a weak agent to induce apoptosis in U۲۶۶B۱ and K۵۶۲ cell lines. Our data showed in terms of WST-۱ and cell count had a significant difference between control and experiment groups (p≤۰.۰۵), while CD۹۵, LDH, and active caspase-۳ did not show such a difference (p>۰.۰۵). Conclusions: We observed that PF۴ released from platelets has a weak potential to induce apoptosis in cancerous cell lines. Other factors may also contribute to this process including the applied dose, purification method, cell line type, and its proteoglycan carrier.

کلیدواژه ها:

Apoptosis ، CXCR۳ ، K۵۶۲ ، Platelet factor ۴ ، Platelet factor ۴ ، CXCR۳ ، Apoptosis ، U۲۶۶B۱ ، K۵۶۲