Molecular Therapy: Methods & Clinical Development (2020-12-01)

A Methodology for Assessing Tumor Clonality of Adult T Cell Leukemia/Lymphoma

  • Tomohiro Yamakawa,
  • Naoki Uno,
  • Daisuke Sasaki,
  • Norihito Kaku,
  • Kei Sakamoto,
  • Kosuke Kosai,
  • Hiroo Hasegawa,
  • Yasushi Miyazaki,
  • Katsunori Yanagihara

Journal volume & issue
Vol. 19
pp. 467 – 473


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While clonal heterogeneity has been demonstrated in most cancers, quantitative assessment of individual tumor clones has not been translated to inform clinical practice. A few methods have been developed to investigate the tumor clonality of adult T cell leukemia/lymphoma (ATLL), but currently there is no clinically translatable method available for quantifying individual tumor clones in ATLL patients. Here, we present a methodology to assess the tumor clonality of ATLL and quantify patient-specific tumor clones in a clinical setting. The methodology consists of three steps: (1) selective amplification of restriction fragments containing a human T cell leukemia virus type 1 (HTLV-1) integration site, (2) amplicon deep sequencing to estimate the clonal structure and identify HTLV-1 integration sites of dominant clones, and (3) digital PCR targeting the HTLV-1 integration sites of the dominant clones to quantify specific tumor clones. We successfully tracked individual tumor clones using this approach and demonstrated that each clone had a distinct response to therapies. The procedure is straightforward and clinically feasible, which should facilitate the proper assessment and management of ATLL.