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 treatment of cervical cancer. However, the side effects of PDT are severe, including skin ulceration, so we designed an experiment 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 implanted with Hela cervical cancer cells. MATERIALS AND METHODS: Female BALB/c nude mice (aged 5-6 weeks, weighing 18-20 g) were used. Hela cervical cancer cells were injected subcutaneously (1 x 10(7) cells/200 µL). Ten days after injection, the mice were divided into three groups (n=6), the A group of controls without any treatment, the B group receiving a single-treatment with Tmpyp4 (10 mg/kg, intratumor injection) and irradiation (blue laser, 108 J/cm(2)), and the C group given three-treatments with Tmpyp4 (10 mg/ kg, intratumor injection) and irradiation at 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 to evaluate tumor histology and organ damage. RESULTS: Tumour growth in C group was significantly inhibited compared with A and B groups (P <0.05), without any injury to the skin and internal organs. CONCLUSION: Our novel findings demonstrated that multiple low-dose photodynamic therapy of Tmpyp4 could inhibit cervical cancer growth significantly with no apparent side effects.

Synergistic anticancer activity of 5-aminolevulinic acid photodynamic therapy in combination with low-dose cisplatin on Hela cells.

OBJECTIVE: Photodynamic therapy (PDT ) is a promising modality for the treatment of various tumors. In order to assist in optimizing treatment, we applied 5-ALA/PDT in combination with low-dose cisplatin to evaluate cytotoxicity in Hela cells. METHODS: Antiproliferative effects of 5-ALA/PDT and cisplatin, alone and in combination, were assessed using MTT assay. To examine levels of apoptosis, Hela cells treated with 5-ALA/PDT, and combination treatment were assessed with Annexin-V/PI by flow cytometry. To investigate the molecular mechanisms underlying alterations in cell proliferation and apoptosis, Western blot analysis was conducted to determine the expression of p53, p21, Bax and Bcl-2 proteins. RESULTS: MTT assays indicated that combination treatment obviously decreased the viability of Hela cells compared to individual drug treatment. In addition, it was confirmed that exposure of Hela cells to 5-ALA/PDT in combination with low-dose cisplatin resulted in more apoptosis in vitro. Synergistic anticancer activity was related to upregulation p53 expression and alteration in expression of p21, Bcl-2 and Bax. CONCLUSION: Our findings suggest that administration of 5-ALA/PDT in combination with the low-dose cisplatin may be an effective and feasible therapy for cervical cancer.