Panoply™ Human CCR9 Over-expressing Stable Cell Line

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy of lymphoid progenitor cells, accounting for approximately 20% of ALL cases and with a higher incidence in adults than in children. Despite the importance of human T-cell lines in understanding the pathobiology of this disease, a detailed comparison of the tumorigenic potential of two commonly used T-cell lines, MOLT4 and JURKAT cells, remains lacking. Here, researchers compared the leukemogenic potential of the two T-cell lines and found that MOLT4 cells exhibited a relatively high leukemogenic potential, as evidenced by their enhanced tissue infiltration in NOD-PrkdcscidIL2rgdull (NTG) mice. Transcriptome analysis of both cell lines revealed enrichment of numerous DEGs, including CCR9, in important signaling pathways associated with growth and proliferation. Notably, upregulation of CCR9 also promoted tissue infiltration of JURKAT cells in vitro and in NTG mice. Transcriptome analysis revealed that CCR9 overexpression promoted cholesterol production by upregulating the expression of the transcription factor SREBF2 and its downstream genes MSMO1, MVD, HMGCS1, and HMGCR, a finding confirmed at the protein level. Notably, simvastatin treatment reduced the migration of CCR9-overexpressing JURKAT cells, suggesting the importance of cholesterol in T-ALL progression.

The researchers determined CCR9 expression in both MOLT4 and JURKAT cells and found increased CCR9 expression in MOLT4 cells (Figure 1A, B). Subsequently, they investigated the role of CCR9 in T-ALL by upregulating CCR9 in JURKAT cells (JURKAT cell line overexpressing CCR9 (OeCCR9-JURKAT) ) (Figure 1C, D). Upregulation of CCR9 increased JURKAT cell migration within the chamber compared to a GFP control (Figure 1E). C-C chemokine ligand 25 (CCL25), a ligand for CCR9, regulates lymphocyte trafficking and induces migration, cell polarization, and microvillar recruitment in CCR9-expressing T-ALL cells, thereby enhancing T-ALL cell infiltration. The researchers observed a synergistic effect of CCL25 addition on the migration of CCR9-overexpressing JURKAT cells (Figure 1E). Notably, overexpression of CCR9 enhanced the invasive capacity of JURKAT cells compared to GFP (Figure 1F), whereas addition of CCL25 did not significantly affect the invasive capacity of OeCCR9-JURKAT cells (Figure 1F). Because MOLT4 cells constitutively express CCR9, the researchers aimed to determine its role in MOLT4 cells by inhibiting its expression. To this end, they stably silenced CCR9 using two different short hairpin RNAs (shRNAs) (Figures 1G, H) and analyzed the effects of these shRNAs on MOLT4 cell migration and invasion. Notably, silencing CCR9 using shRNA-2 reduced the migration and invasion capacity of MOLT4 cells (Figures 1I, J). Addition of CCL25 promoted the migration and invasion of control (vehicle) MOLT4 cells, indicating that CCL25 is dependent on its cognate receptor, CCR9. These findings highlight the functional role of CCR9 in leukemic cell invasiveness.

Figure 1. The aberrant expression of CCR9 affected the metastasis and invasion of T-ALL cell lines. (Jamal M, et al., 2023)