Relationship between changes in antigen expression and protein synthesis in human melanoma cells after hyperthermia and photodynamic treatment

Abstract

Summary Hyperthermia and photoactivated hematoporphyrin derivative induce a dose-dependent reduction in the expression of the p250 surface melanoma-associated antigen on the human FME cell line. Expression of this glycoprotein antigen was quantitated by immunofluorescence flow cytometry based on the monoclonal antibody 9.2.27. Decrease in antigen expression was followed by a transient increase above the level for untreated cells, before normalization occurred about one week after treatment.These treatment-induced changes in antigen expression could partly be explained by changes in protein synthesis. This conclusion was based on the following observations: Hyperthermia and photoactivated hematoporphyrin derivative both inhibited protein synthesis. The latter increased again rapidly to rates above normal until antigen expression reached normal level, whereupon the protein synthesis rate decreased to normal.Inhibition of protein synthesis by cycloheximide 1 day after heating, prevented the recovery of antigen expression, demonstrating that protein synthesis is necessary for resumption of normal antigen expression.The changes in both antigen expression and protein synthesis were dose-dependent, and the magnitude and duration of the changes increased with increasing dose. The time courses of the changes in protein synthesis after two different treatments which both inactivated two logs of cells were almost identical, as were the time courses after two lower heat doses inactivating one log of cells. These similarities were reflected in the changes in antigen expression.At the same time as protein synthesis reached its maximum and antigen expression resumed normal level, an increase in the Golgi apparatus was observed ultrastructurally, indicating an increased synthesis rate and transportation of glycoproteins to the cell surface.

Changes in the expression of idiotype antigen on murine B‐cell lymphoma after hyperthermia alone and in combination with interferon and tumour necrosis factor

“…This delay in recovered antigen expression, as compared with resumption of synthesis rate, might be due to heat-induced damage of organelles and structures involved in the transportation of newly synthesized antigens to the cell surface. Reported heat-induced damage of Golgi apparatus support this suggestion (Mitranic et al, 1976;Davies et al, 1988).…”

“…However, the synthesis rate of total proteins showed a transient increase above normal synthesis rate, suggesting that other proteins might be expressed above normal level. Such transient increase in protein synthesis rate has also been found for other cell lines (Hahn and Shiu, 1985;Davies e l al., 1988), and the synthesis rate of melanoma cells was reported to decrease from the hypernormal synthesis rate at the same time as the expression of melanoma-associated antigen reached normal level (Davies et al, 1988).…”

Alterations in Mitochondrial and Apoptosis‐regulating Gene Expression in Photodynamic Therapy‐resistant Variants of HT29 Colon Carcinoma Cells¶

“…PDT activates several signaling pathways, which in turn alter the expression of many different downstream genes (14). After PDT, inhibition of DNA and RNA polymerases (34,35) and synthesis of DNA, RNA and protein (36,37) have been demonstrated. In vitro studies have shown that PDT can produce single‐ and double‐strand breaks (38–40), sister chromatid exchanges (41,42), chromosome aberrations (43) and mutagenic alterations (38,42,44,45).…”

Alterations in mitochondrial and apoptosis regulating gene expression in photodynamic therapy resistant variants of HT29 colon carcinoma cells

“…PDT activates several signaling pathways, which in turn alter the expression of many different downstream genes (14). After PDT, inhibition of DNA and RNA polymerases (34,35) and synthesis of DNA, RNA and protein (36,37) have been demonstrated. In vitro studies have shown that PDT can produce single-and double-strand breaks (3840), sister chromatid exchanges (4 1,42), chromosome aberrations (43) and mutagenic alterations (38,42,44,45).…”