| Autor: |
Fru PN; Department of Surgery, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa., Nweke EE; Department of Surgery, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa., Mthimkhulu N; Department of Surgery, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa., Mvango S; Biopolymer Modification and Therapeutics Laboratory, Chemicals Cluster, Council for Scientific and Industrial Research, Meiring Naude Road, Brummeria, Pretoria 0001, South Africa.; Department of Chemistry, University of Pretoria, Pretoria 0002, South Africa., Nel M; Department of Surgery, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa., Pilcher LA; Department of Chemistry, University of Pretoria, Pretoria 0002, South Africa., Balogun M; Biopolymer Modification and Therapeutics Laboratory, Chemicals Cluster, Council for Scientific and Industrial Research, Meiring Naude Road, Brummeria, Pretoria 0001, South Africa. |
| Abstrakt: |
Drug delivery systems involving polymer therapeutics enhance drug potency by improved solubility and specificity and may assist in circumventing chemoresistance in pancreatic cancer (PC). We compared the effectiveness of the naturally occurring drug, betulinic acid (BA), alone and in a polymer conjugate construct of polyethylene glycol (PEG), (PEG-BA), on PC cells (MIA PaCa-2), a normal cell line (Vero) and on peripheral blood mononuclear cells (PBMCs). PEG-BA, was tested for its effect on cell death, immunomodulation and chemoresistance-linked signalling pathways. The conjugate was significantly more toxic to PC cells ( p < 0.001, IC 50 of 1.35 ± 0.11 µM) compared to BA (IC 50 of 12.70 ± 0.34 µM), with a selectivity index (SI) of 7.28 compared to 1.4 in Vero cells. Cytotoxicity was confirmed by increased apoptotic cell death. PEG-BA inhibited the production of IL-6 by 4-5.5 fold compared to BA-treated cells. Furthermore, PEG-BA treatment of MIA PaCa-2 cells resulted in the dysregulation of crucial chemoresistance genes such as WNT3A , TXNRD1 , SLC2A1 and GATA3 . The dysregulation of chemoresistance-associated genes and the inhibition of cytokines such as IL-6 by the model polymer construct, PEG-BA, holds promise for further exploration in PC treatment. |
