PIM447 treatment in T-ALL PDX splenocytes

A subset of T-ALL/T-LBL patients is characterized by overexpression of the oncogenic Serine/Threonine kinase PIM1. Mechanisms for PIM1 overexpression are translocations involving the TCRb and PIM1 loci, JAK/STAT activating mutations and responsiveness to cytokinens in the tumor microenvironment, such as IL7. In this study, we generated a TLX3+ JAKwt/STATwt IL7 responsive T-ALL PDX model using NSG mice. Splenocytes were ex vivo treated with the PIM inhibitor PIM447 and QuantSeq 3’ mRNA sequencing was performed, in order to elucidate the transcriptional effects and molecular mechanisms by which PIM447 induces apoptosis in T-ALL PDX cells. Spleen cells from a TLX3+ T-ALL PDX generated in NSG mice were isolated and red blood cell lysis was performed. Single cells were ex vivo treated with DMSO or 1µM PIM447 for 24 hours in 10% RPMI medium. Cells were washed in PBS after treatment and total RNA was isolated using the miRNeasy Mini Kit (Qiagen).