Responses of Cancer Cells Induced by Photodynamic Therapy

Abstract

Photodynamic therapy (PDT) involves the administration of a photosensitizer, followed by local irradiation of tumor tissues using a laser of an appropriate wavelength to activate the photosensitizer. Since multiple cellular signaling cascades are concomitantly activated in cancer cells exposed to the photodynamic effect, understanding the responses of cancer cells to PDT will aid in the development of new interventions. This review describes the possible cell-death signaling pathways initiated by PDT. In addition, we describe our latest findings regarding the induction of expression of miRNAs specific to apoptosis in cancer cells and the induction of antitumor immunity following PDT against cancer cells. A more detailed understanding of the molecular mechanisms related to PDT will potentially improve long-term survival of PDT treated patients.

The effect of aloe-emodin-induced photodynamic activity on the apoptosis of human gastric cancer cells: A pilot study

“…This is followed by the generation of reactive oxygen species (ROS), which result in in cellular destruction (4,5), in particular by inducing cell apoptosis. The mitochondrial pathway has been demonstrated to be involved in cell apoptosis induced by PDT (6,7). …”

Cellular density, a major factor involved in PDT cytotoxic responses: Study on three different lines of human retinoblastoma grafted on nude mice

“…Absorption of light initiates the photochemical reactions generating cytotoxic products like singlet oxygen or other oxygen reactive species (ROS) wherever the proper wavelength meets the photosensitizer. The latter are responsible of the therapeutic effects on the targeted tissues in two major ways [1,2,3]. The first way is a direct one, active on the very site where ROSs have been produced.…”

Red versus blue light illumination in hexyl 5-aminolevulinate photodynamic therapy: the influence of light color and irradiance on the treatment outcomein vitro

“…2,[14][15][16][17][18] In general, the death mode may depend on several factors, including cell-specific properties, type of photosensitizer, light wavelength, total light dose, and irradiance. 17,[19][20][21] Interestingly, the irradiance also modulates immunological responses which are likely to affect treatment outcome.…”