Action of Photodynamic Therapy at Low Fluence in 9 L/lacZ Cells after Interaction with Chlorins

Abstract

Gliosarcoma (GS) is a primary malignant neoplasm of the central nervous system, treated with an unfavorable prognosis with surgery, radiotherapy, and chemotherapy. The treatment for GS consists of surgical resection, almost always accompanied by radiotherapy and/or chemotherapy, given the invasive behavior of the tumor. Photodynamic Therapy (PDT) is studied as an alternative method that combines light, a photosensitizer (PS), and molecular oxygen. This study aimed to compare the effects of PDT using the photosensitizers Fotoenticine (FTC) and Photodithazine (PDZ) at low concentrations and fluences. For this study, 9 L/lacZ cells, concentrations of 1.55 µg mL−1, 12.5 µg mL−1, and 50 µg mL−1 of chlorins and fluences of 1, 5, and 10 J/cm2 were used. A test was also carried out with Trypan Blue in L929 cells at the mentioned concentrations at 5 J/cm2. Both chlorins were internalized in the cytoplasm, with a significant reduction in viability (>95%) in almost all groups and altered cell adhesion and morphology after PDT. HSP70 expression decreased in both PS, while HSP27 increased only in PDT with FTC, and although there was a change in cell adhesion in the 9 L/LacZ lineage it was not observed in the L929 fibroblast lineage. Both chlorins were effective, highlighting the concentration of 50 µg mL−1 at the fluence of 5 J/cm2; according to the present study, the PDZ showed better results.

Keywords

• gliosarcoma
• brain cancer
• photodynamic therapy
• photodithazine
• fotoenticine
• heat shock protein