Mohapatra Purusottam, Yadav Vikas, Toftdahl Maren, Andersson Tommy
Cell and Experimental Pathology, Department of Translational Medicine, Clinical Research Centre, Skåne University Hospital, Lund University, SE-202 13 Malmö, Sweden.
Cancers (Basel). 2020 Feb 4;12(2):346. doi: 10.3390/cancers12020346.
WNT5A is a well-known mediator of melanoma cell invasion and metastasis via its ability to activate protein kinase C (PKC), which is monitored by phosphorylation of the endogenous PKC substrate myristoylated alanine-rich c-kinase substrate (MARCKS). However, a possible direct contribution of MARCKS in WNT5A-mediated melanoma cell invasion has not been investigated. Analyses of melanoma patient databases suggested that similar to expression, expression appears to be associated with increased metastasis. A relationship between the two is suggested by the findings that recombinant WNT5A (rWNT5A) induces both increased expression and phosphorylation of MARCKS, whereas WNT5A silencing does the opposite. Moreover, WNT5A-induced invasion of melanoma cells was blocked by siRNA targeting MARCKS, indicating a crucial role of MARCKS expression and/or its phosphorylation. Next, we employed a peptide inhibitor of MARCKS phosphorylation that did not affect MARCKS expression and found that it abolished WNT5A-induced melanoma cell invasion. Similarly, rWNT5A induced the accumulation of phosphorylated MARCKS in membrane protrusions at the leading edge of melanoma cells. Our results demonstrate that WNT5A-induced phosphorylation of MARCKS is not only an indicator of PKC activity but also a crucial regulator of the metastatic behavior of melanoma and therefore an attractive future antimetastatic target in melanoma patients.
WNT5A是一种众所周知的黑色素瘤细胞侵袭和转移的介质，它能够激活蛋白激酶C（PKC），这一过程可通过内源性PKC底物肉豆蔻酰化富含丙氨酸的蛋白激酶C底物（MARCKS）的磷酸化来监测。然而，MARCKS在WNT5A介导的黑色素瘤细胞侵袭中的直接作用尚未得到研究。对黑色素瘤患者数据库的分析表明，与[此处可能缺失某个基因或蛋白名称]表达相似，[此处可能缺失某个基因或蛋白名称]表达似乎与转移增加有关。重组WNT5A（rWNT5A）诱导MARCKS表达增加和磷酸化，而WNT5A沉默则产生相反效果，这些发现提示了两者之间的关系。此外，靶向MARCKS的小干扰RNA（siRNA）阻断了WNT5A诱导的黑色素瘤细胞侵袭，表明MARCKS表达和/或其磷酸化起关键作用。接下来，我们使用了一种不影响MARCKS表达的MARCKS磷酸化肽抑制剂，发现它消除了WNT5A诱导的黑色素瘤细胞侵袭。同样，rWNT5A诱导磷酸化的MARCKS在黑色素瘤细胞前缘的膜突出中积累。我们的结果表明，WNT5A诱导的MARCKS磷酸化不仅是PKC活性的指标，也是黑色素瘤转移行为的关键调节因子，因此是黑色素瘤患者未来有吸引力的抗转移靶点。
