Relationship of δ-Aminolevulinic Acid-Induced Protoporphyrin IX Levels to Mitochondrial Content in Neoplastic Cells in Vitro

δ-Aminolevulinic Acid Transport in Cancer Cells of the Human Extrahepatic Biliary Duct

“…Indeed, in SK-ChA-1 cells and in intrahepatic cholangiocytes the expression and function of the Na ϩ /H ϩ exchanger NHE2 has been demonstrated apically where it may serve to reabsorb Na ϩ and acidify the biliary fluid (Strazzabosco et al, 1994;Spirli et al, 1998). However, the therapeutic concentration needed has to be tested (Gibson et al, 1999).…”

“…Possible explanations are specific biochemical characteristics in bile duct cancer that are different from other epithelial tumors, thereby requiring optimization of treatment parameters. Gibson et al (1999) found that ␦-ALA-induced protoporphyrin IX reaches different levels in different tumor cells.…”

A Trial of Short Incubation, Broad-Area Photodynamic Therapy for Facial Actinic Keratoses and Diffuse Photodamage

“…25 Cancer cells have reduced ferrochelatase activity 31,32 (the enzyme that catalyzes the last step in heme biosynthesis), 32 leading to increased PpIX levels relative to surrounding normal cells. 33,34 This contributes to preferential destruction of dysplastic cells by ␦-ALA/PDT.…”

In vitro resistance of articular chondrocytes to 5‐Aminolevulinic acid based photodynamic therapy

“…The lower uptake by approximately 80% at 48C as compared to 378C in chondrocytes and osteoblasts indicates the involvement of an active, energy dependent transport system, as their efficiency is reduced at low temperatures [21]. (II) The last enzymatic steps of PpIX synthesis take place in the mitochondria and the mitochondrial content revealed to be proportional to the accumulation of PpIX [23]. Consistently, the low mitochondrial content found in chondrocytes can explain the low levels of PpIX and thus their resistance to 5-ALA-PDT.…”

“…The enzyme citrate synthase (CS) is a mitochondrial marker enzyme and its activity per total cell protein is used to estimate the cellular mitochondrial content [22]. This is a measure for the enzymatic capacity to synthesize and to accumulate PpIX upon exogenous administration of 5-ALA [23]. 10 7 freshly isolated chondrocytes and 3Â10 6 osteoblasts and synovial tissue derived cells, respectively, were harvested, washed three times with PBS, and resuspended in 200 ml 10 mM KPO 4 (pH 7.2).…”