BioProject

Photodynamic therapy (PDT) of solid cancers comprises the administration of a photosensitizer followed by illumination of the photosensitizerreplete tumor with laser light. More...

Photodynamic therapy (PDT) of solid cancers comprises the administration of a photosensitizer followed by illumination of the photosensitizerreplete tumor with laser light. This induces a state of local oxidative stress, culminating in the destruction of tumor tissue and microvasculature and induction of an anti-tumor immune response. However, some tumor types, including perihilar cholangiocarcinoma, are relatively refractory to PDT, which may be attributable to the activation of survival pathways in tumor cells following PDT (i.e., activator protein 1 (AP-1)-, nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB)-, hypoxia-inducible factor 1-alpha (HIF-1α)-, nuclear factor (erythroid-derived 2)-like 2 (NFE2L2), and unfolded protein response-mediated pathways). To assess the activation of survival pathways after PDT, human perihilar cholangiocarcinoma (SK-ChA-1) cells were subjected to PDT with zinc phthalocyanine (ZnPC)-encapsulating liposomes. Following a 30-minute incubation with liposomes, the cells were either left untreated or treated at low (50 mW) or high (500 mW) laser power (cumulative light dose of 15 J/cm2). Cells were harvested 90 minutes post-PDT and whole genome expression analysis was performed using Illumina HumanHT-12 v4 expression beadchips. Overall design: Hilar cholangiocarcinoma (SK-ChA-1) cells were incubated with PBS (control group) or 500 μM zinc phthalocyanine (ZnPC)-encapsulating liposomes (ZnPC-ITLs, final lipid concentration). After 30 minutes, cells that were incubated with ZnPC-ITLs were either kept in the dark (ITL group) or were treated with 500-mW (ITL 500) or 50-mW (ITL 50) laser light (n = 3 per group, cumulative light dose of 15 J/cm2). Ninety minutes after photodynamic therapy, total cellular RNA was isolated and gene expression levels were analyzed by using the Illumina HumanHT-12 v4 platform. The data was analyzed in the context of survival signalling and comparisons were made with the control group. Less...