PhD Scientific Days

Poster Presentation: Pharmaceutical

P05: Cellular uptake and subcellular localization of novel daunorubicin-peptide conjugates

Előadó neve

Orosz, Ádám

Előadó munkahelye

Semmelweis Egyetem Biofizikai és Sugárbiológiai Intézet

Előadó telefonszáma

+36703647003

Előadó e-mail címe

orosz.adam@med.semmelweis-univ.hu

Az előadás címe

Cellular uptake and subcellular localization of novel daunorubicin-peptide conjugates

Szerző(k) neve és munkahelye

Ádám Orosz 1, Krisztina Kiss 2, Beáta Biri-Kovács 2, Rita Oláhné Szabó 2, Gabriella Csík 1, Gábor Mező 2
1 Semmelweis Egyetem Biofizikai és Sugárbiológiai Intézet
2 MTA-ELTE Petidkémiai Kutatócsoport

Szekció

Poster Presentation: Pharmaceutical

Data of the presenter

Doctoral School: Pharmaceutical Sciences
Program: Modern Trends in Pharmaceutical Scientific Research
Supervisor: Gabriella Csík
E-mail: csik.gabriella@med.semmelweis-univ.hu

Text of the abstract

One promising method to overcome the problems associated with chemotherapy of cancerous diseases and increasing its efficacy is targeted tumor therapy. Several peptide receptors are overexpressed on the surface of various cancer cells, therefore the search for suitable ligands is of paramount importance in paving the way to tumor specific targeting.
Our group studied the colon tumor binding peptide Val-His-Leu-Gly-Tyr-Ala-Thr identified from a phage display peptide library. We conjugated this moiety and its modified forms to daunorubicin, a chemotherapeutic antibiotic that intercalates between base pairs of the DNS and inhibits topoisomerase II. An enzyme-degradable spacer was incorporated between the daunorubicin and the targeting peptide to ensure sensitivity to lysosomal enzymes, thus enabling the release of the therapeutic agent once inside the cells.
It was found, that slight modification of the peptide sequence by changing Gly to another amino acid can further increase the in vitro cytostatic effect. Consequently, we synthesized peptide conjugates where Gly is changed to one of the following amino acids: Ala (K1), Phe (K2), Ser (K3), Pro (K4).
Cellular uptake of the new compounds was determined by flow cytometry in HT-29 human colon adenocarcinoma cells after 3 hours of incubation with medium containing the bioconjugates. The uptake of the new derivatives was found to be concentration dependent. By lower concentrations the K2 molecule exhibited the highest affinity to the cells, followed by K1. K3 was only taken up at higher concentrations while K4 showed only moderate internalization.
Subcellular localization was studied using confocal laser scanning microscopy applying lysosome and mitochondrion specific dyes. The conjugates showed roughly similar punctate pattern in the cytoplasm of HT-29 cells after one hour of incubation. Their fluorescence showed co-localization with the lysosome specific dye but not with the mitochondrion label. After 3 hours of incubation daunorubicin signals appeared also in the cell nuclei.

Azonosító

P05

Kind

Szabad

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

1287

PhD Scientific Days 2017

Budapest, 11-12 April 2017