課題番号 ：S-15-NM-0059
利用形態 ：機器利用
利用課題名（日本語） ：
Program Title (English) ：Identification of cell-type-specific mutations in peripheral T-cell lymphoma (PTCL)
利用者名（日本語） ：
Username (English) ：Nguyen Bich Tran
所属名（日本語） ：筑波大学
Affiliation (English) ： University of Tsukuba

１．概要（Summary ）
Peripheral T-cell lymphoma (PTCL) is a hematologic malignancy. Recent genetic analysis has identified recurrent mutations in TET2, DNMT3A, IHD2 and RHOA.1-3 We perform this study to determine the distributions of these gene mutations in PTCL.

２．実験（Experimental）
Nineteen PTCL samples were subjected to this study. The mutation profile of each sample targeting TET2, DNMT3A, IHD2 and RHOA was identified by target sequencing. Next, tumor (PD1 positive) and non-tumor (CD20 positive) cells were isolated using Leica LMD7000 system. Then, the distributions in the tumor cells and the non-tumor cells of those mutations defined by target sequencing were checked by Sanger sequencing.

３．結果と考察（Results and Discussion）
We found that TET2 and DNMT3A mutations　were detected in both the tumor cells and the non-tumor cells while IDH2 and RHOA mutations were detected only in the tumor cells. This implies that IDH2 and RHOA mutations are tumor-specific mutations in PTCL.

Figure 1: RHOA mutations are specific to tumor cell-enriched fractions
A. An example of the immunostaining pattern for PD1 and CD20 in the PTCL samples. Left, PD1+ cells; right, CD20+ cells.
B. Sanger sequence of G17V RHOA mutations in whole tumor, PD1+ cells, and CD20+ cells.

Figure 2: Distributions of TET2/RHOA/IDH2 mutations
A. IDH2 mutations are specific to tumor cell-enriched fractions cells. Sanger sequence of IDH2 p.R172 mutations in whole tumor, PD1+ cells, and CD20+ cells.
B. Allele frequencies of TET2/RHOA/IDH2 mutations in TET2 and IDH2 co-mutated samples.
References:
1. Sakata-Yanagimoto M, Enami T, Yoshida K et al. Somatic RHOA mutation in angioimmunoblastic T cell lymphoma. Nat Genet. 2014; 46(2): 171-175.
2. Palomero T, Couronne L, Khiabanian H et al. Recurrent mutations in epigenetic regulators, RHOA and FYN kinase in peripheral T cell lymphomas. 2014; 46(2): 166-170.
3. Yoo HY, Sung MK, Lee SH et al. A recurrent inactivating mutation in RHOA GTPase in angioimmunoblastic T cell lymphoma. Nat Genet. 2014; 46(4): 371-375.

４．その他・特記事項（Others）

５．論文・学会発表（Publication/Presentation）
(1) Tran B. Nguyen, Mamiko Sakata-Yanagimoto and Shigeru Chiba, 第20回造血器腫瘍研究会　　2016.2.12～2.13

６．関連特許（Patent）