Synthesis, structural characterization, and inhibitory effects of caffeic acid phenethyl ester (CAPE) derivatives on human multiple myeloma cell growth
Location
Suwanee, GA
Start Date
17-4-2026 12:00 PM
End Date
17-4-2026 1:00 PM
Description
Multiple Myeloma (MM) is a hematologic cancer characterized by the proliferation of malignant plasma cells in the bone marrow. The accumulation of MM cells leads to a range of complications, including anemia, bone disease, and renal damage. MM remains challenging to treat due to its drug resistance and the associated side effects, leading researchers to explore naturally derived compounds as adjuvants with current treatments. Caffeic acid phenethyl ester (CAPE) has demonstrated various pharmacological properties, including anti-cancer effects. Previous studies have reported that CAPE and its derivatives inhibit MM cell growth by inducing apoptosis and oxidative stress. The objective of this project is to determine if newly synthesized CAPE derivatives are more potent inhibitors of MM cell growth than CAPE.
CAPE derivatives were synthesized through coupling reactions involving caffeic acid with derivatives of phenylalanine and tyrosine (Figure 1). MM cell line, RPMI 8226, was cultured in RPMI 1640 medium supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin. MM cells were treated with CAPE and its synthesized derivatives, then incubated for 24, 48, and 72 hours prior to cell viability assays using Presto Blue™. In preparation for Western blotting, MM cells were treated with compounds for 24 hours. Protein (20 µg) was extracted and loaded into precast gels, then transferred to ImmunBlot PVDF membranes. Membranes were incubated overnight in primary antibody solutions (β-actin and α-tubulin) and the following day for one hour in secondary antibody solutions (cleaved caspase 3, GPX4, and CHAC1). Statistical analyses included ANOVA and Dunnett’s multiple-comparison tests, performed with GraphPad Prism 9.3.1, to determine statistical significance.
CAPE derivatives were evaluated for their effects on RPMI 8226 cell viability, which decreased in a time- and dose-dependent manner. Western blot analysis showed that apoptosis is not the sole mechanism of cell death in CAPE derivatives, prompting further investigation into their potential association with ferroptosis. When combined with the ferroptosis inducer Erastin, a significant reduction in cell viability was observed; no significant effect was observed with the ferroptosis inhibitor Ferrostatin-1. Additionally, Western blot analysis showed a notable decrease in GPX4 expression and an increase in CHAC1 expression when combined with Erastin. The opposite results were observed when the derivatives were combined with Ferrostatin-1, with increased GPX4 expression and decreased CHAC1 expression.
The results of the experiment confirmed the inhibitory effects of the most potent CAPE derivatives, such as CAPE-7 and CAPE-9, on RPMI 8226 (MM) cells, consistent with previous studies. Ferroptosis induction may be the main mechanism underlying the inhibitory effects of CAPE derivatives, rather than apoptosis induction. The structure-activity relationship of CAPE and its derivatives reveals that replacing the ester group with an amide results in a stronger cell death response, as seen in two derivatives compared to CAPE. The data highlights how structural modifications can either preserve or diminish CAPE's effects, emphasizing the critical role of structural changes in modulating its activity.
Embargo Period
5-15-2026
Synthesis, structural characterization, and inhibitory effects of caffeic acid phenethyl ester (CAPE) derivatives on human multiple myeloma cell growth
Suwanee, GA
Multiple Myeloma (MM) is a hematologic cancer characterized by the proliferation of malignant plasma cells in the bone marrow. The accumulation of MM cells leads to a range of complications, including anemia, bone disease, and renal damage. MM remains challenging to treat due to its drug resistance and the associated side effects, leading researchers to explore naturally derived compounds as adjuvants with current treatments. Caffeic acid phenethyl ester (CAPE) has demonstrated various pharmacological properties, including anti-cancer effects. Previous studies have reported that CAPE and its derivatives inhibit MM cell growth by inducing apoptosis and oxidative stress. The objective of this project is to determine if newly synthesized CAPE derivatives are more potent inhibitors of MM cell growth than CAPE.
CAPE derivatives were synthesized through coupling reactions involving caffeic acid with derivatives of phenylalanine and tyrosine (Figure 1). MM cell line, RPMI 8226, was cultured in RPMI 1640 medium supplemented with 10% fetal bovine serum and 1% penicillin-streptomycin. MM cells were treated with CAPE and its synthesized derivatives, then incubated for 24, 48, and 72 hours prior to cell viability assays using Presto Blue™. In preparation for Western blotting, MM cells were treated with compounds for 24 hours. Protein (20 µg) was extracted and loaded into precast gels, then transferred to ImmunBlot PVDF membranes. Membranes were incubated overnight in primary antibody solutions (β-actin and α-tubulin) and the following day for one hour in secondary antibody solutions (cleaved caspase 3, GPX4, and CHAC1). Statistical analyses included ANOVA and Dunnett’s multiple-comparison tests, performed with GraphPad Prism 9.3.1, to determine statistical significance.
CAPE derivatives were evaluated for their effects on RPMI 8226 cell viability, which decreased in a time- and dose-dependent manner. Western blot analysis showed that apoptosis is not the sole mechanism of cell death in CAPE derivatives, prompting further investigation into their potential association with ferroptosis. When combined with the ferroptosis inducer Erastin, a significant reduction in cell viability was observed; no significant effect was observed with the ferroptosis inhibitor Ferrostatin-1. Additionally, Western blot analysis showed a notable decrease in GPX4 expression and an increase in CHAC1 expression when combined with Erastin. The opposite results were observed when the derivatives were combined with Ferrostatin-1, with increased GPX4 expression and decreased CHAC1 expression.
The results of the experiment confirmed the inhibitory effects of the most potent CAPE derivatives, such as CAPE-7 and CAPE-9, on RPMI 8226 (MM) cells, consistent with previous studies. Ferroptosis induction may be the main mechanism underlying the inhibitory effects of CAPE derivatives, rather than apoptosis induction. The structure-activity relationship of CAPE and its derivatives reveals that replacing the ester group with an amide results in a stronger cell death response, as seen in two derivatives compared to CAPE. The data highlights how structural modifications can either preserve or diminish CAPE's effects, emphasizing the critical role of structural changes in modulating its activity.
Comments
Presented by Tiffanie Hoang.