Enhanced in vitro antiproliferative effects of EpCAM antibody-functionalized paclitaxel-loaded PLGA nanoparticles in retinoblastoma cells
Authors: Sanjeeb K Sahoo
Subramanian Krishnakumar
Ranjita Misra
Anju Harilal
Moutushy Mitra
Journal: Molecular vision (2011)
Discipline: CLINICAL MEDICINE
Keywords: paclitaxel; retinoblastoma; PLGA NPs; EpCAM antibody; drug delivery
Affiliations: Department of Ocular Pathology, Vision Research Foundation, Sankara Nethralaya, Tamil Nadu, India.

Abstract:  Background: To specifically deliver paclitaxel (PTX) to retinoblastoma (RB) cells, the anionic surface-charged poly(lactic-co-glycolic acid) (PLGA) NPs loaded with paclitaxel were conjugated with epithelial cell adhesion molecule (EpCAM) antibody for enhancing site-specific intracellular delivery of paclitaxel against EpCAM overexpressing RB cells. Methods: PTX-loaded PLGA NPs were prepared by the oil-in-water single emulsion solvent evaporation method, and the PTX content in NPs was estimated by the reverse phase isocratic mode of high performance liquid chromatography. Ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide chemistry was employed for the covalent attachment of monoclonal EpCAM antibody onto the NP surface. In vitro cytotoxicity of native PTX, unconjugated PTX-loaded NPs (PTX-NPs), and EpCAM antibody-conjugated PTX-loaded nanoparticles (PTX-NP-EpCAM) were evaluated on a Y79 RB cell line by a dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, while cellular apoptosis, cysteinyl-aspartic acid protease (caspase)-3 activation, Poly (adenosine diphosphate-ribose) polymerase (PARP) cleavage, and cell-cycle arrest were quantified by flow cytometry. By employing flow cytometry and fluorescence image analyses, the extent of cellular uptake was comparatively evaluated. Results: PTX-NP-EpCAM had superior antiproliferation activity, increased arrested cell population at the G(2)-M phase, and increased activation of caspase-3, followed by PARP cleavage in parallel with the induction of apoptosis. Increased uptake of PTX-Np-EpCAM by the cells suggests that they were mainly taken up through EpCAM mediated endocytosis. Conclusions: EpCAM antibody-functionalized biodegradable NPs for tumor-selective drug delivery and overcoming drug resistance could be an efficient therapeutic strategy for retinoblastoma treatment. 

Retracted: No

PubPeer comments:
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 2017 correction. http: mcb.asm.org content 37 15 e00232-17.full , 
 The Actin band in Figure 1C appears to have been reused in Figure 3H as a Tsc2 band. It appears to have been spliced differently, contrast adjusted and the dimensions have been adjusted. It is difficult to understand how these transformations could occur by accident. This issue was not addressed in the previous correction. *** Original ![file] *** False color, contrast adjusted to aid in comparison ![file] , 
 The 2017 correction reads:  *Fig. 3A to F: During figure assembly, the blots from panel C were accidentally replicated in panel D and the top blot intended for panel D was mistakenly placed into panel F. In addition, while the blots used in all six panels were representative of results for the three genotypes, they erroneously did not correspond to the exact biological replicates used. The correct blots should appear as shown below. The associated graphs are not affected by these corrections of the blots, and the corrections do not affect the conclusions of the article.* Here is the original Figure 3, as reported to the journal in September 2016. Boxes of the same color mark panels that looked similar. On the left the marked original figure, and on the right a false-color version. ![file] While I thank the authors for explaining that none of the six Akt blots originally shown were the correct ones, that actually is very concerning. Could the authors please clarify how the reader then can be certain that any of the other blots *are* correct? I also agree with Actinopolyspora Biskrensis comment in #4. Could the authors please also address that? This paper was part of a structured search for image duplications in Molecular and Cellular Biology paper, which was published here: https: mcb.asm.org content 38 20 e00309-18.long ,