Photodynamic therapy of cervical cancer by eradication of cervical cancer cells and cervical cancer stem cells

// Elvin Peter Chizenga 1 , Rahul Chandran 1 and Heidi Abrahamse 1 1 Laser Research Centre, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa Correspondence to: Heidi Abrahamse, email: habrahamse@uj.ac.za Keywords: photodynamic therapy; cervical cancer; cancer stem cells; photosensitizer; cancer resistance Received: April 10, 2019     Accepted: May 30, 2019     Published: July 09, 2019 ABSTRACT The heterogeneous nature of cancer puts cancer stem cells (CSCs) at the beating heart of the tumour. Because of their inherent characteristics of stemness, CSCs evade putative cancer therapies, resulting in treatment resistance or tumour recurrence after a seemingly successful treatment. To prevent treatment resistance and cancer recurrence, killing the beating heart of the tumour is of utmost importance. This study therefore, sought to determine the effect of Photodynamic Therapy (PDT) in eradicating cervical cancer and cervical CSCs. Cervical CSCs were isolated from a cervical adenocarcinoma cell line, HeLa cells, and grown in liquid medium incubated at 37° C, 5% CO 2 and 85% humidity. Increasing doses of AlPcS mix photosensitizer were administered to both the total cell population and the isolated CSCs, and irradiated using 673.2 nm diode laser. Post-irradiation cellular changes were observed using biochemical assays and microscopy to determine the response of both the total cell population and the CSCs. Results showed a dose-dependent response of both cell populations to treatment, by demonstration of significant morphologic changes, increased cytotoxicity, and decreased cell viability and proliferation. The study suggested that PDT using AlPcS mix is a very effective treatment method for the eradication of cervical cancer cells and cervical CSCs, in vitro .