Panoply™ Human RIPK1 Over-expressing Stable Cell Line

RIPK1 (receptor-interacting serine/threonine protein kinase 1) has been found to be aberrantly expressed and associated with the pathogenesis of various solid tumors, but its role in hematologic malignancies remains unclear. Here, to identify a multifunctional target for B-cell cancer therapy, researchers reanalyzed a public transcriptome dataset from the Gene Expression Comprehensive Database (GEO), which included CD19⁺ B cell populations from 6 healthy donors and 5 patients with chronic lymphocytic leukemia (CLL), 10 patients with follicular lymphoma (FL), and 8 patients with diffuse large B-cell lymphoma (DLBCL). Overlap analysis of three differentially expressed genes (DEGs) yielded 69 common DEGs, three of which were validated by real-time quantitative PCR, including RIPK3, IGSF3, and TGFBI. Interestingly, loss of RIPK1 function significantly enhanced the proliferation and survival of GM12878 cells (a normal human B lymphocyte line). Overexpression of RIPK1 in TMD8 and U2932 cells effectively inhibited cell proliferation and growth. More importantly, regulating RIPK1 kinase activity through small molecules (such as necrotizing 1 and HOIPIN-1) can alter the cell growth state of B-cell lymphoma, indicating that RIPK1 has anti-tumor activity in B-cell lymphoma. These studies suggest that RIPK1 may be a potential target for the clinical treatment of B-cell lymphoma, including chronic lymphocytic leukemia, diffuse large B-cell lymphoma, and follicular lymphoma.

Here, researchers constructed TMD8 and U2932 cell lines stably overexpressing RIPK1 (Figure 1A). CCK8 assay results showed that the proliferation rate of RIPK1-overexpressing TMD8 cells was significantly lower than that of the empty vector group (Figure 1B). Similarly, similar results were observed in RIPK1-overexpressing U2932 cells (Figure 1B). These results directly indicate that RIPK1 has an inhibitory effect on B lymphocyte proliferation. Simultaneously, researchers assessed the cell viability of the RIPK1-overexpressing TMD8 and U2932 cell lines (Figure 1C). The results showed that the cell viability of RIPK1-overexpressing U2932 cells decreased 24 hours after inoculation, similar to the situation with TMD8 cells (after 36 hours) (Figure 1C). Furthermore, in RIPK1-overexpressing TMD8 cells, the proportion of G2 phase cells was significantly reduced, from 19.3% in the empty vector group to 13.4% in the RIPK1 group (Figures 1D and 1E). Similarly, the proportion of G2 phase cells in U2932 cells overexpressing RIPK1 decreased from 23.7% to 19.4%. Furthermore, overexpression of RIPK1 in U2932 and TMD8 cells increased cell death rates by 1.1-fold and 0.8-fold, respectively (Figure 1F). These results indicate that RIPK1 has an inhibitory effect on the proliferation of B lymphocytes.

Figure 1. Ectopic RIPK1 in lymphocytes suppresses cell growth. (Wu, et al., 2023)