Relationship of protoporphyrin IX synthesis to photodynamic effects by 5-aminolaevulinic acid and its esters on various cell lines derived from the skin

Abstract

PpIX production by ALA and its esters was induced on both normal and malignant cell lines derived from the skin, and cell death of PDT responses is closely related to the amount of PpIX synthesis rather than to the irradiation dose.

Activity of phosphatase-sensitive 5-aminolevulinic acid prodrugs in cancer cell lines

“…It has been established that the efficacy of PDT is closely related to the amount of PpIX produced in cells, rather than the irradiation dose used. 34,35 Moreover, Moan et al showed that PpIX generation in cells is cell density and cell volume dependent being higher in G2 and M phase in comparison to G1. 36 Another explanation for the discrepancies in phototoxicity results between different cell lines may come from the fact that the photosensitivity of cells is larger in high-density cultures 36 .…”

Photodynamic therapy with hexenyl ester of 5-aminolevulinic acid induces necrotic cell death in salivary gland adenocarcinoma cells

“…ALA was purchased from Sigma (St. Louis, MO, USA). The ALA hexenyl ester (C11H19NO3·HCl, ALA-hx) were made as previously described (18). ALA and ALA-hx were dissolved in serumfree RPMI medium immediately before use.…”

“…SGT cells were washed with PBS and incubated in serum-free culture medium containing each photosensitizer of ALA and ALA-hx. Four hours after photosensitizer administration, the cells were exposed with light doses of 5 J/cm 2 of a red light-emitting diode (LED) light with 613-645 nm wavelength, with peak 635 nm (Philips Luxeon Lumileds, San Jose, CA, USA) at 35 mW/cm 2 as measured with a Delta Ohm DO 9721 quantum photo-radiometer and thermometer data logger (model DO9721, Padua, Italy) (18).…”

“…Additionally, PDT using ALA-hx (ALA-hx PDT) significantly suppressed the tumor cell proliferation and induced cell death in vitro (18,19). In this study, we examined anti-cancer effect of ALA-hx PDT in the SGT salivary gland tumor cell line.…”

“…We have previously demonstrated that ALA-hexenyl ester (ALA-hx), as an unsaturated alkyl ester, increased the PpIX accumulation in cell compared to other esters of ALA in a broad range of concentrations (18). Additionally, PDT using ALA-hx (ALA-hx PDT) significantly suppressed the tumor cell proliferation and induced cell death in vitro (18,19).…”