Addition of a histone deacetylase inhibitor redirects tamoxifen-treated breast cancer cells into apoptosis, which is opposed by the induction of autophagy.

Modulation of estrogen signaling is one of the most successful modalities for the treatment of estrogen receptor (ER)-positive breast cancer, yet de novo and acquired resistance are frequent. Recent data suggests that the induction of autophagy may play a considerable role in promoting tumor cell survival and resistance to anti-estrogen therapy. Hence, bypassing autophagy may offer a novel strategy to enhance the anti-tumor efficacy of anti-estrogens.

Endocytosis of titanium dioxide nanoparticles in prostate cancer PC-3M cells.

Unlabelled: Nanotechnology has introduced many exciting new tools for the treatment of human diseases. One of the obstacles in its application to that end is the lack of a fundamental understanding of the interaction that occurs between nanoparticles and living cells. This report describes the quantitative analysis of the kinetics and endocytic pathways involved in the uptake of anatase titanium dioxide (TiO(2)) nanoparticles into prostate cancer PC-3M cells.

Labeling TiO2 nanoparticles with dyes for optical fluorescence microscopy and determination of TiO2-DNA nanoconjugate stability.

Visualization of nanoparticles without intrinsic optical fluorescence properties is a significant problem when performing intracellular studies. Such is the case with titanium dioxide (TiO2) nanoparticles. These nanoparticles, when electronically linked to single-stranded DNA oligonucleotides, have been proposed to be used both as gene knockout devices and as possible tumor imaging agents.

Intracellular distribution of TiO2-DNA oligonucleotide nanoconjugates directed to nucleolus and mitochondria indicates sequence specificity.

Deoxyribonucleic acid (DNA) oligonucleotides hybridize to matching DNA sequences in cells, as established in the literature, depending on active transcription of the target sequence and local molarity of the oligonucleotide. We investigated the intracellular distribution of nanoconjugates composed of DNA oligonucleotides attached to TiO2 nanoparticles, thus creating a locally increased concentration of the oligonucleotide. Two types of nanoconjugates, with oligonucleotides matching mitochondrial or nucleolar DNA, were specifically retained in mitochondria or nucleoli.