Journal of Advanced Biomedical Sciences

en CD47 and SIGLEC15 Immune Checkpoint Genes Expression and Apoptotic Pathway Activation Following Photodynamic Therapy with Zinc Phthalocyanine in the B-CPAP Thyroid Cancer Cell Line ايمونولوژي Immunology پژوهشي Research <div style="text-align: justify;">Background & Objectives: Thyroid cancer is one of the most prevalent endocrine malignancies. Photodynamic therapy is an emerging minimally invasive therapeutic modality that employs a photosensitizer in conjunction with light irradiation to induce targeted cytotoxicity. The present study was designed to evaluate the effects of zinc phthalocyanine-mediated photodynamic therapy on the expression of immune checkpoint genes CD47 and SIGLEC15, as well as key genes involved in apoptotic pathways, in papillary thyroid cancer cells. Materials & Methods: The human papillary thyroid cancer cell line B-CPAP was exposed to various concentrations of zinc phthalocyanine and subsequently irradiated using a 675 nm diode laser at a fluence of 24 J/cm². Cellular viability, reflecting mitochondrial metabolic activity, was assessed using the MTT assay. The relative mRNA expression levels of CD47, SIGLEC15, Caspase-3, Caspase-9 and Bcl-2 genes were quantified using quantitative real-time polymerase chain reaction. Results:  Zinc phthalocyanine-mediated photodynamic therapy markedly reduced the viability of B-CPAP cells. The treatment activated the intrinsic apoptotic pathway, as demonstrated by the significant upregulation of Caspase-3 and Caspase-9 transcripts alongside the downregulation of Bcl-2 expression. In addition, a statistically significant reduction in the mRNA expression levels of the immune checkpoint molecules CD47 and SIGLEC15 was observed following treatment. Conclusion:  The findings of this study provide novel evidence that zinc phthalocyanine-mediated photodynamic therapy simultaneously induces apoptosis while downregulating the critical immune checkpoints CD47 and SIGLEC15 in thyroid cancer cells. This dual mechanism of action underscores the therapeutic potential of photodynamic therapy as an effective strategy for enhancing antitumor efficacy through both direct cytotoxic effects and the potential mitigation of immune evasion. Keywords: Thyroid cancer, Photodynamic therapy, Zinc phthalocyanine, Immune checkpoints, Apoptosis CD47 and SIGLEC15 Immune Checkpoint Genes Expression and Apoptotic Pathway Activation Following Photodynamic Therapy with Zinc Phthalocyanine in the B-CPAP Thyroid Cancer Cell Line Photodynamic Therapy, Immune Checkpoints, and Apoptosis in Thyroid Cancer Background & Objectives: Thyroid cancer is one of the most prevalent endocrine malignancies. Photodynamic therapy is an emerging minimally invasive therapeutic modality that employs a photosensitizer in conjunction with light irradiation to induce targeted cytotoxicity. The present study was designed to evaluate the effects of zinc phthalocyanine-mediated photodynamic therapy on the expression of immune checkpoint genes CD47 and SIGLEC15, as well as key genes involved in apoptotic pathways, in papillary thyroid cancer cells. Materials & Methods: The human papillary thyroid cancer cell line B-CPAP was exposed to various concentrations of zinc phthalocyanine and subsequently irradiated using a 675 nm diode laser at a fluence of 24 J/cm². Cellular viability, reflecting mitochondrial metabolic activity, was assessed using the MTT assay. The relative mRNA expression levels of CD47, SIGLEC15, Caspase-3, Caspase-9 and Bcl-2 genes were quantified using quantitative real-time polymerase chain reaction. Results:  Zinc phthalocyanine-mediated photodynamic therapy markedly reduced the viability of B-CPAP cells. The treatment activated the intrinsic apoptotic pathway, as demonstrated by the significant upregulation of Caspase-3 and Caspase-9 transcripts alongside the downregulation of Bcl-2 expression. In addition, a statistically significant reduction in the mRNA expression levels of the immune checkpoint molecules CD47 and SIGLEC15 was observed following treatment. Conclusion:  The findings of this study provide novel evidence that zinc phthalocyanine-mediated photodynamic therapy simultaneously induces apoptosis while downregulating the critical immune checkpoints CD47 and SIGLEC15 in thyroid cancer cells. This dual mechanism of action underscores the therapeutic potential of photodynamic therapy as an effective strategy for enhancing antitumor efficacy through both direct cytotoxic effects and the potential mitigation of immune evasion. Keywords: </div> Thyroid cancer, Photodynamic therapy, Zinc phthalocyanine, Immune checkpoints, Apoptosis 0 0 http://jabs.fums.ac.ir/browse.php?a_code=A-10-3520-1&slc_lang=en&sid=1 Golnaz Fallah گلناز فلاح golnaz.fallah@gmail.com 100319475328460030622 0009-0000-6646-6581 No Department of Genetics, Ta.C., Islamic Azad University, Tabriz, Iran Mehrdad Pashazadeh مهرداد پاشازاده Mehrdadpashazadeh85@gmail.com 100319475328460030623 100319475328460030623 Yes Department of Medical Laboratory Sciences and Microbiology, TaMS.C., Islamic Azad University, Tabriz, Iran Abolfazl Jafari-Sales ابوالفضل جعفری ثالث a.jafari_1392@yahoo.com 100319475328460030624 100319475328460030624 No Infectious Diseases Research Center, TaMS.C., Islamic Azad University, Tabriz, Iran Habib Tajalli حبیب تجلی tajallihabib@gmail.com 100319475328460030625 100319475328460030625 No Biophotonics Research Center, Ta.C., Islamic Azad University, Tabriz, Iran Seyedeh Samaneh Shahriar-oskouei سیده سمانه شهریار اسکویی seyedehsamanehshahriaroskouei@gmail.com 100319475328460030626 0009-0006-8349-4983 No Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran