Abstract 3853: Humanized NOD/Scid/IL2g-/- tumor grafts recapitulate primary anaplastic large cell lymphoma

Anaplastic large cell lymphoma (ALCL) is a subtype of peripheral T-cell lymphoma that includes two entities ALK+ and ALK- ALCL based on chromosomal translocations of the anaplastic lymphoma kinase (ALK). ALK- ALCL have very poor clinical outcome with conventional chemotherapy. Lack of representative cell lines and/or models has compromised the development of successful therapy. Toward this end, we report the generation and characterization of a group of novel ALCL tumor grafts. We implanted subcutaneously (s.c.) tumor tissue fragments, fresh or viable cryopreserved, from 11 cases of primary systemic ALCL (3 ALK+ and 8 ALK-) in six- to eight-week old severe immunocombined immunodeficiency NOD Cg-Prkdcscid/Il2rgtm1wjl/SzJ (NSG) mice. A single leukaemic ALCL sample was injected i.v. or s.c. Six cases led to successful lymphoma growth within 6-12 weeks as subcutaneous solid spheroid masses constituted by a uniform population of large pleomorphic cells CD30-positive. All tumor grafts were re-implanted in recipient animals, in same cases up to 21 consecutive implants with an analogous time growth rate. Two cases, in the same way of the original human neoplasia, were early associated with concomitant enlargement of multiple organs. All tumor graft lines eventually showed disseminate disease with involvement of distant lymph nodes and of spleen (with homig in peri-arteriolar spaces), liver (initially observed within the sinusoidal spaces) and kidney. The morphological and immunohistochemical (IHC) evaluation (expression of CD30, cytotoxic proteins and ALK) of the serially propagated ALCL tumor grafts demonstrated a high concordance between primary and derived animal tumors which showed highly stable profile along different passages from the early generation (T1) until the final ones (up to T16). The clonal relationship with primary and corresponding tumor grafts was confirmed by gene TCR rearrangement analyses and by ALK FISH studies. In addition we interrogated the model using gene expression profiling and single nucleotide polymorphism which established a close relationship among primary and derived tumors. Massive parallel sequencing on mRNA transcripts defines the presence of two novel chimeras involving NF1-MAZ and TRAF1-ALK1, which confirmes the evidence of ALK signaling and pinpoint a role of RAS in ALK- ALCL. The tumor grafts displayed, also, therapeutic responses with conventional therapy (CHOP) which reflected that seen in the donor patients: initial partial responses followed invariably by clinical relapses. To overcome this refractory we assayed the sensitivity of two tumorgraft lines, generated from ALK+ ALCL, to a new selective ALK inhibitor (CEP28122) that led a rapid and stable response. This study demonstrated the key role of these libraries of tumor grafts, especially in developing and testing new therapeutic regimens in refractory ALCL patients. Citation Format: Fabrizio Tabbo’, Antonella Barreca, Rodolfo Machiorlatti, Katia Messana, Indira Landra, Francesco Abate, Michela Boi, Maria Todaro, Cristina Abele, Domenico Novero, Alberto Zamo’, Marco Chilosi, Maurilio Ponzoni, Mangeng Cheng, Bruce Ruggeri, Pierpaolo Piccaluga, Stefano Pileri, Enrico Tiacci, Brunangelo Falini, Lenny Shultz, Roberto Piva, Enzo Medico, Francesco Bertoni, Raul Rabadan, Giorgio Inghirami. Humanized NOD/Scid/IL2g-/- tumor grafts recapitulate primary anaplastic large cell lymphoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3853. doi:10.1158/1538-7445.AM2013-3853