Efficacy of Multiple Low-dose Photodynamic TMPYP4 Therapy on Cervical Cancer Tumour Growth in Nude Mice

Objective: Photodynamic therapy (PDT) is an emerging therapeutic procedure suitable for the treatmentof cervical cancer. However, the side effects of PDT are severe, including skin ulceration, so we designed anexperiment to examine the effects of multiple low- dose photodynamic therapy of 5, 10, 15, 20-tetrakis(1-methylpyridinium-4-yl) porphyrin (Tmpyp4) on tumour growth by utilizing a model in nude mice implantedwith Hela cervical cancer cells. Materials and
Methods: Female BALB/c nude mice (aged 5–6 weeks, weighing18–20 g) were used. Hela cervical cancer cells were injected subcutaneously (1×107 cells/200 μL). Ten days afterinjection, the mice were divided into three groups (n=6), the A group of controls without any treatment, the Bgroup receiving a single-treatment with Tmpyp4 (10 mg/kg, intratumor injection) and irradiation (blue laser, 108J/cm2), and the C group given three-treatments with Tmpyp4 (10 mg/ kg, intratumor injection) and irradiationat intervals of two days. After starting treatment, tumours were measured every two days, to assess growth.At 2 weeks after the last treatment of C group, tumour tissue and organs were collected from each mouse toevaluate tumor histology and organ damage.
Results: Tumour growth in C group was significantly inhibitedcompared with A and B groups (P <0.05), without any injury to the skin and internal organs.
Conclusion: Ournovel findings demonstrated that multiple low-dose photodynamic therapy of Tmpyp4 could inhibit cervicalcancer growth significantly with no apparent side effects.