2016年3月10日
Activation of the thrombopoietin receptor by mutant calreticulin in CALR-mutant myeloproliferative neoplasms.
Blood
- 巻
- 127
- 号
- 10
- 開始ページ
- 1307
- 終了ページ
- 16
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1182/blood-2015-09-671172
Recurrent somatic mutations of calreticulin (CALR) have been identified in patients harboring myeloproliferative neoplasms; however, their role in tumorigenesis remains elusive. Here, we found that the expression of mutant but not wild-type CALR induces the thrombopoietin (TPO)-independent growth of UT-7/TPO cells. We demonstrated that c-MPL, the TPO receptor, is required for this cytokine-independent growth of UT-7/TPO cells. Mutant CALR preferentially associates with c-MPL that is bound to Janus kinase 2 (JAK2) over the wild-type protein. Furthermore, we demonstrated that the mutant-specific carboxyl terminus portion of CALR interferes with the P-domain of CALR to allow the N-domain to interact with c-MPL, providing an explanation for the gain-of-function property of mutant CALR. We showed that mutant CALR induces the phosphorylation of JAK2 and its downstream signaling molecules in UT-7/TPO cells and that this induction was blocked by JAK2 inhibitor treatment. Finally, we demonstrated that c-MPL is required for TPO-independent megakaryopoiesis in induced pluripotent stem cell-derived hematopoietic stem cells harboring the CALR mutation. These findings imply that mutant CALR activates the JAK2 downstream pathway via its association with c-MPL. Considering these results, we propose that mutant CALR promotes myeloproliferative neoplasm development by activating c-MPL and its downstream pathway.
- リンク情報
- ID情報
-
- DOI : 10.1182/blood-2015-09-671172
- PubMed ID : 26817954