Photoimmunotherapy by Cortactin monoclonal antibody conjugated with Hematoporphyrin derivative of a subcutaneous murine mammary adenocarcinoma using low power He-Ne laser

Abstract

Photoimmunotherapy (PIT) is a promising approach which aims to increase the specificity of photosensitisers used in photodynamic therapy through its conjugation to monoclonal antibodies (MAb) directed against tumour antigens. The current study aims to increase and improve the therapeutic selectivity of photodynamic therapy (PDT) by conjugating the HpD to specific (mAb) in order to target one of the specific antigens of mammary adenocarcinoma. a screening has been done to detect specific antigens on mammary adenocarcinoma cells and we found that Cortactin is the unique antigen on tumor tissue in our model, then anti-cortactin mAb was linked to HPD, used for not only improve specificity, but vastly enhances tumor cell killing when they are photo-immunotargeted by HpD-monoclonal antibody conjugates comparing with unconjugated HPD and then exposed to low power He-Ne laser (632 nm). Female mice, which were transplanted with AM3 (mouse mammary adenocarcinoma transplantable tumor line), were randomly divided into five groups of 10 mice each; the first group was treated by PIT using HpD conjugated with Cortactin, in comparison with HpD alone in a second group. The third and fourth were control groups with and without HpD alone respectively. Tumor growth indices and metastasis incidence were calculated. Photoimmunotargeting by HpD-mAb conjugates activated by a low-power He-Ne laser showed significant tumor growth inhibition similar to PDT using unconjugated HpD activated by He-Ne laser, whilst control groups were without any significant effect. The resultssuggest that conjugation was with low quantity of the HPD or not stable enough and this need further studies.