The PPTC childhood PDX panel — 90 leukaemia models, an MLL-ALL group, and no published partner or age breakdown
also called Pediatric Preclinical Testing Consortium PDX panel · PPTC · PPTP
The main American paediatric cancer mouse-model collection has ninety leukaemia models, some with KMT2A fusions. The published description does not say which fusion partners or how old the children were, so you cannot tell from it whether infant material with our fusion is in there.
The same thing, for a scientist
The Pediatric Preclinical Testing Consortium genomically characterised **261 PDX models across 37 paediatric cancers**, with oncoprints for **90 acute lymphoblastic leukaemia models** and a named MLL-ALL subgroup in which, the paper states, all models contain a canonical KMT2A fusion and have relatively silent genomes with minimal copy-number alterations. Fusion detection confirmed KMT2A fusions in all MLL-ALL models. **The published text gives no partner breakdown for the MLL-ALL group and no donor ages**, so the number of PPTC models that are KMT2A::AFF1, and the number from infants, cannot be established from the publication. The predecessor NCI Pediatric Preclinical Testing Program cell-line panel does contain a t(4;11) representative: RS4;11, which is from a 32-year-old adult.
A bounded unresolved, not a bounded absence
This entry records something the project's conventions have no slot for: a resource that is clearly relevant, is published, and whose relevant field is simply not in the paper. Full text was retrieved (PMC6880934, via efetch db=pmc after Europe PMC fullTextXML returned HTTP 500) and a <body> element confirmed present, so this is not an unreadable-paper case. The partner composition of the MLL-ALL group is in supplementary Table S5, which the retrieved XML references but does not contain 1.
So the honest state is: unresolved, with the exact route to resolution known — download PPTC Table S5, or query the PedcBioPortal/PPTC portal that hosts these models. Nobody has done it for this graph.
The genomic silence of MLL-ALL is itself a finding worth keeping
The paper reports that MLL-ALL models have relatively silent genomes with minimal copy-number alterations, against 45-48% of BCP-ALL models carrying CDKN2A/CDKN2B focal deletions and BCP-ALL models enriched for RAS-pathway (KRAS 30%, NRAS 18%) and JAK-STAT alterations 1. That reproduces in PDX what is known of the primary disease, and it is a point in favour of PDX over cell lines for this fusion: the cell lines in this inventory are not genomically silent — SEM, ALL-PO, KOCL-45, KOCL-69 and HB11;19 all carry TP53 or CDKN2A lesions that the models retain and the patients mostly do not.
| total pdx models | 261 |
|---|---|
| cancer types | 37 |
| all models | 90 |
| mll all group | present; every model carries a canonical KMT2A fusion |
| kmt2a aff1 models | NOT STATED in the published text |
| infant models | NOT STATED in the published text |
| resolution route | PPTC supplementary Table S5 and the PPTC/PedcBioPortal model metadata — not retrieved for this beat |
| full text retrieval | PMC6880934 via efetch db=pmc after Europe PMC fullTextXML HTTP 500; <body> present |
| obtainable | PPTC models are distributed to investigators through the consortium |
- A resource whose relevant metadata sits only in supplementary material behaves, for anyone building an inventory from published text, exactly like a resource that does not exist.
- PDX models select for engraftment. If infant KMT2A::AFF1 blasts engraft less readily than older-child blasts, the consortium panel would under-represent precisely the population of interest and nothing in the publication would show it.
- How many PPTC MLL-ALL models carry KMT2A::AFF1, and how many donors were under one year? Table S5 answers this and is one download away.
- Do PPTC's MLL-ALL models retain the genomic silence of the primary disease through passage? The paper states they do at the panel level; per-model confirmation would make them clearly preferable to the cell lines for co-lesion-sensitive work.
- E1established confidence 5 of 5: Multiple independent lines of evidence; treated as settled in the field.paper
The Pediatric Preclinical Testing Consortium genomically characterised 261 patient-derived xenograft models from 37 unique paediatric cancers, including oncoprints for 90 acute lymphoblastic leukaemia models; all MLL-ALL models contain a canonical KMT2A fusion and have relatively silent genomes with minimal copy number alterations, while 45-48% of B-cell precursor ALL models contain focal CDKN2A or CDKN2B deletions and BCP-ALL models are enriched for RAS-pathway (KRAS 30%, NRAS 18%) and JAK-STAT alterations.
Genomic Profiling of Childhood Tumor Patient-Derived Xenograft Models to Enable Rational Clinical Trial Design · Rokita JL, Rathi KS, Cardenas MF, et al. · Cell Reports 2019What this evidence cannot show
Full text read via PMC (PMC6880934), recovered with efetch db=pmc after Europe PMC fullTextXML returned HTTP 500; a <body> element was confirmed present. The KMT2A partner composition of the MLL-ALL group and the donor ages are in supplementary material (Table S5) that was not retrieved, so the number of KMT2A::AFF1 and of infant models is NOT established by this item. The paper also states the consortium had no models for several histologies, so the panel is not comprehensive by design.
Evidence that argues against this (1)
- The leukaemia arm of PPTC is generated and maintained at the Children's Cancer Institute in Sydney, with animal work approved by UNSW, so the 'consortium' panel's ALL models come substantially from one laboratory. A resource built at one site samples the referral pattern of that site, which for an ultra-rare infant subtype could mean very few models or none, and the paper gives no way to tell. Townsend EC et al. 2016
- E2established confidence 5 of 5: Multiple independent lines of evidence; treated as settled in the field.database
The NCI Pediatric Preclinical Testing Program cell-line panel includes RS4;11, which Cellosaurus records as derived from a 32-year-old female and assigns the NCIt disease term 'Adult B acute lymphoblastic leukemia'.
Cellosaurus cell line RS4;11 (CVCL_0093) · Bairoch A, et al. (SIB Swiss Institute of Bioinformatics) · Cellosaurus 2025What this evidence cannot show
Fetched by accession 2026-09-19. PPTP membership is a Cellosaurus 'Part of' annotation; the composition of the PPTP cell-line panel as a whole was not enumerated for this entry, so this establishes that an adult line is in a paediatric panel and not that it is the panel's only t(4;11) representative.
Evidence that argues against this (1)
- A paediatric testing programme choosing RS4;11 was choosing the best-characterised, most reliably growing t(4;11) line available at the time, which is a defensible selection criterion. The alternative reading — that no infant line was considered — is not supported by anything, and several infant t(4;11) lines predate the programme. Drexler HG et al. 2004
- E9established confidence 5 of 5: Multiple independent lines of evidence; treated as settled in the field.database
The PPTC supplementary table carrying the per-model partner breakdown and donor ages is unreachable by every free route tried. Europe PMC's supplementaryFiles endpoint for PMC6880934 returns a **well-formed 176-byte zip archive that names `NIHMS1542708-supplement-5.xlsx` and contains it at zero bytes**; the NCBI PMC bin path returns HTTP 404; the pmc.ncbi.nlm.nih.gov path returns HTTP 200 with 1,817 bytes of HTML rather than a spreadsheet; and the Europe PMC fulltextRepo endpoint returns HTTP 500.
Europe PMC supplementaryFiles endpoint for PMC6880934, and three alternative routes to NIHMS1542708-supplement-5.xlsx · EMBL-EBI / NCBI PMC 2026What this evidence cannot show
All four routes attempted by the coordinator on 2026-09-20 from one network location, with no institutional access and no browser. The publisher's own site was not tried and would very likely succeed, so this is a bounded failure of this project's programmatic routes rather than a statement that the table is unavailable.
Evidence that argues against this (2)
- **The first route fails in the most dangerous way available.** It returns HTTP 200, a valid zip, and a correctly-named entry — every check short of reading the bytes passes. A script that confirmed 'the archive downloaded and contains the table' would report success. This is the same family as the empty `ArticleTitle`, the PMC record with no `<body>`, and the `esearch` returning a well-formed `count: 0`: **well-formed, named, and empty.** EMBL-EBI / NCBI PMC 2026
- Not having this table leaves the beat's PPTC claims resting on the abstract and main text, which state the panel size and the existence of an MLL-ALL group but not its partner composition or donor ages. The entry should not be read as establishing that infant KMT2A::AFF1 PDX models do or do not exist in the panel — that question is exactly what the missing table answers. Cancer Discovery 2019
- related to →KMT2A-rearranged acute lymphoblastic leukaemia
90 ALL PDX models including an MLL-ALL group in which every model carries a canonical KMT2A fusion
the predecessor PPTP cell-line panel's t(4;11) representative is an adult line
- ← related toEnumeration for the index-fusion model beat: what was searched, found, rejected and could not be read
records PPTC Table S5 as the highest-value unretrieved item