Figure S3. Effects of the Hec1-NEK2 inhibitor, T-1101 tosylate, on PEL viability. (A-C) Viability of PEL cells treated with vehicle control (DMSO, black line) or various concentrations of T-1101 tosylate over time. Data were normalized to the 0h luminescence values for each treatment and represent mean ± SEM. Curves were fitted using non-linear regression and represent three independent biological replicates, each performed in triplicate. (D) IC50 curves of PEL cells treated with various concentrations of T-1101 tosylate or JH295 for 72h and normalized to the DMSO control values. Individual data points are plotted for two-three independent biological replicates, each performed in triplicate. Curves were fitted using non-linear regression and are connected by means. See also Table S3. (E) Viability of PEL cells treated with DMSO, 500 nM T-1101 tosylate, or 500 nM JH295. Data are plotted as individual data points of three independent biological replicates performed in triplicate, normalized to the DMSO control values, and represent mean ± SEM. Data were analyzed using two-way ANOVA with Šídák’s multiple comparisons. ****p < 0.0001. The DMSO data in both graphs in (E) are the same.
ARTICLE ABSTRACT
Non–Hodgkin lymphoma (NHL) is a common cancer in both men and women and represents a significant cancer burden worldwide. Primary effusion lymphoma (PEL) is a subtype of NHL infected with Kaposi sarcoma–associated herpesvirus (KSHV). PEL is an aggressive and lethal cancer with no current standard of care, owing largely to its propensity to develop resistance to current chemotherapeutic regimens. Here, we report a reliance of KSHV-positive PEL on the mitotic kinase, NEK2, for survival. Inhibition of NEK2 with the inhibitor, JH295, resulted in caspase 3–mediated apoptotic cell death of PEL. Furthermore, NEK2 inhibition significantly prolonged survival and reduced tumor burden in a PEL mouse model. We also demonstrate that the ABC transporter proteins, MDR1 and MRP, are most active in PEL and that inhibition of NEK2 in PEL reduced the expression and activity of these ABC transporter proteins, which are known to mediate drug resistance in cancer. Finally, we report that JH295 treatment sensitized lymphomas to other chemotherapeutic agents such as rapamycin, resulting in enhanced cancer cell death. Overall, these data offer important insight into the mechanisms underlying PEL survival and drug resistance, and suggest that NEK2 is a viable therapeutic target for PEL.
The mitotic kinase, NEK2, is important for the survival of KSHV-positive PEL. NEK2 inhibition resulted in PEL apoptosis and reduced tumor burden in a mouse model. NEK2 inhibition also reduced drug resistance.
