Synthesis and Biological Evaluation of Potential Oncoimmunomodulator Agents

Abstract

Fourteen triazole-scaffold derivatives were synthetized and biologically evaluated as potential oncoimmunomodultator agents by targeting both PD-L1 and c-Myc. First, the antiproliferative activity of these molecules on the monocultures of several tumor cell lines (HT-29, A-549, and MCF-7) and on the non-tumor cell line HEK-293 was studied. Then, the effects on the mentioned biological targets were also evaluated. Finally, the effect on cancer cell viability when the molecules were co-cultured with immune cells (Jurkat T cells or THP-1) was also determined. Compounds bearing a bromoophenyl group were selected because of their excellent results, and their effect on IL-6 secretion was also studied. In conclusion, we found compounds that are capable of downregulating c-Myc, as well as influencing and altering the distribution of PD-L1 in tumor cells; the compounds are thus capable of influencing the behavior of defensive cells towards cancer cells. p-Bromophenyltriazol 3 is the most active of these as a PD-L1 and c-Myc downregulator and as a potential immunomodulator agent. Moreover, it exhibits an interesting action on inflammation-related cytokine IL-6.

Keywords: IL-6; PD-L1; angiogenesis; c-Myc; co-cultures; flow cytometry; immunomodulation; multitarget inhibitors; small molecules.

Figure 1

Design of new potential immunomodulator agents.

Scheme 1

Synthetic route to the triazole derivatives.^a. Reagents and conditions: (a). BH₃·SMe₂, THF anh., rt., 12 h, (97%); (b). 4,4′-dimetoxytrityl chloride, Et₃N, DMAP, CH₂Cl₂, rt., 22 h, (35%); (c). TsCl, Et₃N, DMAP, CH₂Cl₂, rt., 4 h, (62%); (d). NaN₃, DMF, 50 °C, 3 h, (83%); (e). alkyne, CuSO₄·5H₂O, Sodium ascorbate, DMF:H₂O, 60 °C, 2 h; (f). trifluoroacetic acid, MeOH, rt., 30 min.

Figure 2

Confocal images of MCF-7 cell cultures, stained in blue for the nucleus, green for c-Myc, and red for PD-L1, after 24 h of treatment with: (a) compound 3, (b) compound 5, (c) compound 7, (d) DMSO as negative control, (e) BMS-8.

Figure 3

General structure of synthetic derivatives.

Figure 4

Effect of bromo and methoxy derivatives 3–14 on the targets (c-Myc, total and membrane PD-L1) and on cancer cell viability in co-cultures of Jurkat T cells: (a) HT-29, (b) MCF-7, (c) A-549.

Figure 5

Comparison of the effect of selected compounds 3, 5, 7 on MCF-7 viability when co-cultured with immune cells.