Publications by authors named "Ronita Roy"

2 Publications

  • Page 1 of 1

In vivo longitudinal imaging of RNA interference-induced endocrine therapy resistance in breast cancer.

J Biophotonics 2020 01 9;13(1):e201900180. Epub 2019 Oct 9.

Division of Molecular Imaging, Department of Radiology, Baylor College of Medicine, Houston, Texas.

Endocrine therapy resistance in breast cancer is a major obstacle in the treatment of patients with estrogen receptor-positive (ER+) tumors. Herein, we demonstrate the feasibility of longitudinal, noninvasive and semiquantitative in vivo molecular imaging of resistance to three endocrine therapies by using an inducible fluorescence-labeled short hairpin RNA (shRNA) system in orthotopic mice xenograft tumors. We employed a dual fluorescent doxycycline (Dox)-regulated lentiviral inducer system to transfect ER+ MCF7L breast cancer cells, with green fluorescent protein (GFP) expression as a marker of transfection and red fluorescent protein (RFP) expression as a surrogate marker of Dox-induced tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) knockdown. Xenografted MCF7L tumor-bearing nude mice were randomized to therapies comprising estrogen deprivation, tamoxifen or an ER degrader (fulvestrant) and an estrogen-treated control group. Longitudinal imaging was performed by a home-built multispectral imaging system based on a cooled image intensified charge coupled device camera. The GFP signal, which corresponds to number of viable tumor cells, exhibited excellent correlation to caliper-measured tumor size (P < .05). RFP expression was substantially higher in mice exhibiting therapy resistance and strongly and significantly (P < 1e-7) correlated with the tumor size progression for the mice with shRNA-induced PTEN knockdown. PTEN loss was strongly correlated with resistance to estrogen deprivation, tamoxifen and fulvestrant therapies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jbio.201900180DOI Listing
January 2020

Au nanomatryoshkas as efficient near-infrared photothermal transducers for cancer treatment: benchmarking against nanoshells.

ACS Nano 2014 Jun 3;8(6):6372-81. Epub 2014 Jun 3.

Department of Chemistry, Rice University , 6100 Main Street, Houston, Texas 77005, United States.

Au nanoparticles with plasmon resonances in the near-infrared (NIR) region of the spectrum efficiently convert light into heat, a property useful for the photothermal ablation of cancerous tumors subsequent to nanoparticle uptake at the tumor site. A critical aspect of this process is nanoparticle size, which influences both tumor uptake and photothermal efficiency. Here, we report a direct comparative study of ∼90 nm diameter Au nanomatryoshkas (Au/SiO2/Au) and ∼150 nm diameter Au nanoshells for photothermal therapeutic efficacy in highly aggressive triple negative breast cancer (TNBC) tumors in mice. Au nanomatryoshkas are strong light absorbers with 77% absorption efficiency, while the nanoshells are weaker absorbers with only 15% absorption efficiency. After an intravenous injection of Au nanomatryoshkas followed by a single NIR laser dose of 2 W/cm(2) for 5 min, 83% of the TNBC tumor-bearing mice appeared healthy and tumor free >60 days later, while only 33% of mice treated with nanoshells survived the same period. The smaller size and larger absorption cross section of Au nanomatryoshkas combine to make this nanoparticle more effective than Au nanoshells for photothermal cancer therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/nn501871dDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4076033PMC
June 2014