Oral Presentation 18th International Congress on Photobiology 2024

New treatment option for rectal cancer: X-ray activated photodynamic therapy (#144)

Wei Deng 1
  1. University of Technology Sydney, Sydney, NSW, Australia

Rectal cancer accounts for approximately 30% of colorectal cancers which is the 2nd most deadly cancer in Australia [1]. A significant proportion of Stage II-III rectal cancer patients undergo chemo-radiotherapy to downsize the primary tumour and lymph node metastasis before surgery [2]. Unfortunately, the side effect of this standard of care treatment is progressive late morbidity due to high doses in long-course radiotherapy and toxicity of chemodrugs used in chemo-radiotherapy [3]. To improve the quality of life of rectal cancer patients, it is important to find a new and safe treatment method. Here we brought a new treatment method, X-ray triggerable photodynamic therapy (X-PDT), by combining existing clinical techniques used in cancer treatment and delivering via bespoke nanocarriers [4]. In this strategy verteporfin (VP), a clinically approved photosensitizer, was directly activated by X-ray via a nanoplatform. The activated VP generates highly toxic reactive oxygen species, killing the cancer cells. With X-PDT, the tumour growth suppression was observed in an orthotopic mouse model bearing rectal cancer. Such tumour control is consistent with decreased cell viability, increased necrotic tumour tissue and reduced Ki-67 protein expression observed in the mouse group treated with X-PDT, compared with other treatment conditions. Our study establishes an effective strategy to treat rectal cancer in a more clinically relevant model, which offers prospects for clinical translation of this technology for deep seated cancers.

Rui Sang 1, Sheri Nixdorf 2, Kelly McKelvey3, Tzongtyng Hung 4, Alexander Engel 5, Ewa M. Goldys 1 and Wei Deng 2

1 The Graduate School of Biomedical Engineering, University of New South Wales, Kensington, NSW, Australia

2 The School of Biomedical Engineering, Faculty of Engineering and IT, University of Technology Sydney, Broadway, NSW, Australia

3 The Bill Walsh Translational Research Laboratory, The University of Sydney and Royal North Shore Hospital Research, St Leonards, NSW, Australia

4 Biological Resources Imaging Laboratory, UNSW Sydney, Sydney, NSW, 2052, Australia

5 Sydney Medical School, University of Sydney, Sydney, NSW, Australia

References:

  1. P. Thavaneswaran, M. Solomon, J. Young, Cancer Council Australia Colorectal Cancer Guidelines Working Party. Guidelines: Colorectal cancer/Colorectal Cancer in Australia. In: Clinical practice guidelines for the prevention, early detection and management of colorectal cancer. Sydney: Cancer Council Australia. [Version URL: https://wiki.cancer.org.au/australiawiki/index.php?oldid=173034, cited 2023 Apr 27]
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  3. YH Xie, YX Chen, JY Fang. Comprehensive review of targeted therapy for colorectal cancer. Signal transduction and targeted therapy, 2020, 5, 22.
  4. W Deng, K McKelvey, A Guller, A Fayzullin, J Campbell, S Clement, A Habibalahi, Z Wargocka, L Liang, C Shen, V Howell, A Engel and E Goldys, Application of mitochondrially targeted nanoconstructs to neo-adjuvant X-ray-induced photodynamic therapy for rectal cancer, ACS Central Science, 2020, 6, 715