Development of a multifunctional luciferase reporters system for assessing endoplasmic reticulum-targeting photosensitive compounds

Abstract

Photodynamic therapy (PDT) is a recently developed antitumor modality utilizing the generation of reactive oxygen species (ROS), through light irradiation of photosensitizers (PSs) localized in tumor. Interference with proper functioning of endoplasmic reticulum (ER) by ER-targeting PDT is a newly proposed strategy to achieve tumor cell death. The aim of this study is to establish a multifunctional model to screen and assess ER-targeting PSs based on luciferase reporters system. Upregulation of GRP78 is a biomarker for the onset of ER stress. CHOP is a key initiating player in ER stress-induced cell death. Here, the most sensitive fragments of GRP78 and CHOP promoters responding to ER-targeting PDT were mapped and cloned into pGL3-basic vector, forming −702/GRP78-Luc and −443/CHOP-Luc construct, respectively. We demonstrated that −702/GRP78-Luc expression can be used to indicate the ER-targeting of PSs, meanwhile estimate the ROS level induced by low-dose ERtargeting PDT. Moreover, the luciferase signaling of −443/ CHOP-Luc showed highly consistence with apoptosis rate caused by ER-targeting PDT, suggesting that −443/CHOPLuc can evaluate the antitumor properties of PSs. Hypericin, Foscan® and methylene blue were applied to verify the sensitivity and reliability of our model. These results proved that GRP78-CHOP model may be suitable to screen ER-targeting photosensitive compounds with lower cost and higher sensitivity than traditional ways.

Functional Polymer Nanocarriers for Photodynamic Therapy

“…Therefore, subcellular targeting is another area worthy of exploration to improve the photodynamic response after cell internalization [48,126]. At present, subcellular targeting for mitochondria [127], endoplasmic reticulum [45,128], lysosome [126], and nucleus [46,129] has been developed with only a fairly limited number [48]. Among which, mitochondria targeting is of special concern.…”

Genotoxic effects of photodynamic therapy in laryngeal cancer cells – Anin vitrostudy

“…These data can suggest that the degree of toxicity generated instantly after PDT has a sharp relevance to the damage to the genetic material of cells exposed to the PDT treatment; the ROS reacts not only with active organelles, such as mitochondria and reticules, but also affects the cell as a whole, damaging the nuclear membrane and even its DNA. 3,8,53 After 48 h, the Control group also presented an increase in relation to the 24-h period. The cell data median was even 22.23% smaller than that of the PDT group, and the percentage DNA median of the comet tail was 49.66%.…”

“…The damage to cancer cells and their vital subcellular structures resulting from the action of ROS can lead to cell death by either apoptosis or necrosis. [1][2][3][4][5] In addition, the use of PDT in the treatment of cancer is very attractive because of its intrinsic double selectivity, i.e. the photosensitizer has a great tendency to accumulate in the malignant tissue and the irradiated light is spatially…”

Rational design of block copolymer self-assemblies in photodynamic therapy

“…Some authors proposed as therapeutic strategy to interfere with ER functions by generating stress through ER-targeted PDT. In vitro cellular assay was developed to screen ER-targeting photosensitizers with ideal photoactivity [216]. Wan et al designed ER-targeted micelles for PDT that can be efficiently loaded with the antitumor drug paclitaxel [177].…”