TIMAP downregulation in Burkitt's lymphoma reveals key molecules and signaling pathways in B-cell lymphomagenesis

Obeidat et al., Experimental Biology and Medicine, 2025 asked what TIMAP does in a B-cell lymphoma. The protein is a regulatory subunit of protein phosphatase 1, it is enriched in lymphoid tissue and raised in several cancers, and an earlier mouse model had implicated it in lymphomagenesis, but nobody had mapped what happens downstream when it is removed from a lymphoma cell. The authors first showed by immunohistochemistry that TIMAP is higher in Burkitt's lymphoma, diffuse large B-cell lymphoma and follicular lymphoma tissue than in normal lymph node, and confirmed expression in the Raji and Daudi cell lines.

The knockdown was done with four self-delivering AUMsilence sdASOs against TIMAP messenger RNA, pooled and used together, against an AUM scramble control. Raji cells are a suspension B-cell line, and the oligonucleotides were mixed into the growth medium at 2 μM with no transfection reagent, the medium refreshed at 48 hours and RNA and protein taken at 72. TIMAP messenger RNA came out at a fold change of 0.70 in the treated cells and 0.97 in the scrambled control, with p equal to 0.001 across four replicates, and TIMAP protein at a median of 0.73 against 1.00 in the scramble, with p equal to 0.002 across six. The authors call this roughly a 30% knockdown. Treated cells also grew significantly less than scramble-treated cells from an identical starting count.

That partial knockdown was enough to reshape the transcriptome. RNA sequencing found 2,368 differentially expressed genes, 1,326 up and 1,042 down, clustering into B-cell receptor signalling, p53 signalling, mTOR signalling, apoptosis, homologous recombination and DNA replication. Individual genes were confirmed by qPCR: PAK3 went from undetectable in control cells to induced after knockdown, BCL2 rose to 1.35 against 0.75 in the scramble at P equal to 0.03, and AICDA fell to 0.53 against 1.1, at P equal to 0.07 and so above the paper's own significance threshold. The study is a clean demonstration that a modest, self-delivered knockdown in a hard-to-transfect suspension line can carry a whole transcriptomic experiment.