Structural alterations in cell organelles induced by photodynamic treatment with chlorin p6 -histamine conjugate in human oral carcinoma cells probed by 3D fluorescence microscopy.

Abstract

We have explored the intracellular cell organelle's structural alterations after photodynamic treatment with chlorin p6 -histamine conjugate (Cp6 -his) in human oral cancer cells. Herein, the cells were treated with Cp6 -his (10 μm) and counterstained with organelle-specific fluorescence probes to find the site of intracellular localization using confocal microscopy. For photodynamic therapy (PDT), the cells were exposed to ~30 kJ/m2 red light (660 ± 20 nm) to induce ~90% cytotoxicity. We used the three-dimensional (3D) image reconstruction approach to analyze the photodynamic damage to cell organelles. The result showed that Cp6 -his localized mainly in the endoplasmic reticulum (ER) and lysosomes but not in mitochondria and Golgi apparatus (GA). The 3D model revealed that in necrotic cells, PDT led to extensive fragmentation of ER and fragmentation and swelling of GA as well. Results suggest that the indirect damage to GA occurred due to loss of connection between ER and GA. Moreover, in damaged cells with no sign of necrosis, the perinuclear ER appeared condensed and surrounded by several small clumps at the peripheral region of the cell, and the GA was observed to form a single condensed structure. Since these structural changes were associated with apoptotic cell death, it is suggested that the necrotic and apoptotic death induced by PDT with Cp6 -his is determined by the severity of damage to ER and indirect damage to GA. The results suggest that the indirect damage to cell organelle apart from the sites of photosensitizer localization and the severity of damage at the organelle level contribute significantly to the mode of cell death in PDT.

• Authors: Arpana Parihar, Alok Dube
• Journal: Luminescence : the journal of biological and chemical luminescence (Luminescence) Vol. 38 Issue 7 Pg. 1175-1184 (Jul 2023) ISSN: 1522-7243 [Electronic] England
• PMID: 35698308 (Publication Type: Journal Article)
• Copyright: © 2022 John Wiley & Sons Ltd.

Chemical References

• chlorin
• Histamine
• Porphyrins
• Photosensitizing Agents

Topics

• Humans
• Histamine (metabolism, therapeutic use)
• Organelles (metabolism)
• Porphyrins (pharmacology, chemistry)
• Photosensitizing Agents (pharmacology, chemistry, therapeutic use)
• Mouth Neoplasms (drug therapy, metabolism)
• Microscopy, Fluorescence
• Carcinoma (drug therapy, metabolism)
• Photochemotherapy (methods)
• Cell Line, Tumor