Apoptotic and autophagic responses to photodynamic therapy in 1c1c7 murine hepatoma cells

Andrzejak, Michelle; Price, Michael R.; Kessel, David

doi:10.4161/auto.7.9.15865

Cited by 90 publications

(100 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…10,13 We recently reported that shRNA knockdown of Atg7 suppressed the development of autophagy, and reduced the lightdose needed to kill murine hepatoma 1c1c7 cells loaded with either mitochondrial or endoplasmic reticulum (ER) photosensitizers. 10,11 These results are consistent with the proposal that autophagy plays a prosurvival role under these conditions. After lysosomal photodamage, we have shown that autophagosomes previously photosensitized with WST11 (1 μM, 16 h) resulted in the loss of punctate LTR fluorescence, consistent with lysosomal/ endosomal photodamage ( Fig.…”

Section: Introductionsupporting

confidence: 82%

“…10 In the context of PDT, the induction of macroautophagy (referred to here as 'autophagy') often functions as a survival response in cells capable of developing an apoptotic response. [10][11][12] However, if pathways to apoptosis are impaired, autophagy may play a role in cell death. 10,13 We recently reported that shRNA knockdown of Atg7 suppressed the development of autophagy, and reduced the lightdose needed to kill murine hepatoma 1c1c7 cells loaded with either mitochondrial or endoplasmic reticulum (ER) photosensitizers.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

ATG7 deficiency suppresses apoptosis and cell death induced by lysosomal photodamage

2012

Self Cite

View full text Add to dashboard Cite

Section: Introductionsupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

ATG7 deficiency suppresses apoptosis and cell death induced by lysosomal photodamage

2012

Self Cite

View full text Add to dashboard Cite

“…However, one should keep in mind that mTHPC is a strong photo-inducer of necrosis (30) with a minor contribution of apoptosis and as such the inhibition of this process does not contribute significantly to cell phototoxicity. It has been suggested that autophagy plays a prodeath role in PDT-mediated killing in apoptosis-defective cells (7,9), or in cells exhibiting a slow apoptotic response (6,42).…”

Section: Discussionmentioning

confidence: 99%

“…PDT is known as a potent inducer of apoptosis in many types of cells (3)(4)(5). Recent evidence indicates that the second type of programmed cell death (PCD), namely autophagy, may be induced by PDT (6)(7)(8)(9)(10). Autophagy is developed by cells into an attempt to repair and survive photodamage to key organelles but could be turned into a cell death signal if initial response fails (9,11).…”

Section: Introductionmentioning

confidence: 99%

mTHPC-based photodynamic therapy induction of autophagy and apoptosis in cultured cells in relation to mitochondria and endoplasmic reticulum stress

Franï¿1⁄2ois¹

2011

Int J Oncol

View full text Add to dashboard Cite

Abstract. Photodynamic therapy (PDT), an approved anticancer treatment, is reported as a potent inducer of programmed cell death (PCD) by both apoptosis and autophagy. The present study investigated the kinetics of both autophagy and caspase activation in MCF-7 cells submitted to mTHPC-PDT upon condition of treatment promoting ER accumulation of mTHPC. Fluence-dependent immediate cytochrome c (cyt C) release followed by caspase-9 and -7 activation at 1 h post-PDT evidenced a mitochondrial oxidative stress triggered by high light doses leading to >90% of cell death. ER oxidative stress was monitored by the induction of the glucose-related protein chaperone GRP78. From 6 h post-PDT, GRP78 induction was accompanied by the conversion of LC3-I into LC3-II, the hallmark of autophagosome formation. The formation of acid vesicles evidenced by fluorescence microscopy was obvious from 22 h post-PDT. Twenty-four hours post-PDT, cyt C release decreased and caspase-9 cleavage disappeared, while the expression of cleaved caspase-7 remained significant. At the same time, the profiles of GRP78, cleaved caspase-7 and LC3-II expression were similar irrespective of light doses. In contrast to an inhibitor of caspase activation Z-VAD-FMK, the use of autophagy inhibitor, Wortmannin, impaired cytotoxicity along with an increase in caspase-7 activation. These results demonstrate a valuable contribution of autophagy to cell death in mTHPC-photosensitized MCF-7 cells.

show abstract

“…Individually, neither the PS, at the concentrations used in the photodynamic treatment, nor the light used to activate the PS are harmful to the cells and the organisms. In contrast, the illumination of the PS molecules with light of wavelengths included in their absorption spectrum, triggers a series of events that culminate in the production of ROS which ultimately causes cell death via necrosis, apoptosis or autophagy [11][12][13][14]. The prevailing mechanism of death is determined by the cell type, the PDT dose, the type of PS and its precise localization inside the cells and other treatment conditions [15].…”

Section: Basic Principles Of Pdtmentioning

confidence: 99%

Strategies for optimizing the delivery to tumors of macrocyclic photosensitizers used in photodynamic therapy (PDT)

Moret

Reddi

2017

J. Porphyrins Phthalocyanines

View full text Add to dashboard Cite

This review briefly summaries the principles and mechanisms of action of photodynamic therapy (PDT) as concerns its application in the oncological field, highlighting its drawbacks and some of the strategies that have been or are being explored to overcome them. The major aim is to increase the efficiency and selectivity of the photosensitizer (PS) uptake in the cancer cells for optimizing the PDT effects on tumors while sparing normal cells. Some attempts to achieve this are based on the conjugation of the PS to biomolecules (small ligands, peptides) functioning as carriers with the ability to efficiently penetrate cells and/or specifically recognize and bind proteins/receptors overexpressed on the surface of cancer cells. Alternatively, the PS can be entrapped in nanocarriers derived from various types of materials that can target the tumor by exploiting the enhanced permeability and retention (EPR) effects. The use of nanocarriers is particularly attractive because it allows the simultaneous delivery of more than one drug with the possibility of combining PDT with other therapeutic modalities.

show abstract

Apoptotic and autophagic responses to photodynamic therapy in 1c1c7 murine hepatoma cells

Cited by 90 publications

References 24 publications

ATG7 deficiency suppresses apoptosis and cell death induced by lysosomal photodamage

ATG7 deficiency suppresses apoptosis and cell death induced by lysosomal photodamage

mTHPC-based photodynamic therapy induction of autophagy and apoptosis in cultured cells in relation to mitochondria and endoplasmic reticulum stress

Strategies for optimizing the delivery to tumors of macrocyclic photosensitizers used in photodynamic therapy (PDT)

Contact Info

Product

Resources

About