In-vivo Breast cancer tumor model
In-vivo Breast cancer tumor model was developed based on a previously established method by Noori et al. (11). A female Balb/c mouse bearing spontaneous mouse mammary tumor (SMMT) was obtained form Iranian institute of Pasteur. Previous data indicated that SMMT effectively resembles characteristics of Iranian patient’s invasive ductal carcinoma (12). SMMT was then carefully separated, dissected into smaller pieces with sizes of less than 0.5 cm3 and subsequently, transplanted to 6-8 weak old healthy syngeneic Balb/c mice by surgery. 12 days after transplantation, when tumors reached to the size of 500 mm3, 107 and 108cfu/g BW25133 bacteria bearing cardiac hormone expressing construct, as well as 108 bacteria without construct and PBS as control were injected systemically to each mouse through the tail vein. A total of three Injections, each with a 4-day interval was performed. To evaluate the effect of treatment on tumor growth delay, tumor volume was measured on predetermined intervals according to the following formula:
V(mm3) = a2 × b × 0.5
In which a and b represents the shorter and longer diameters (mm) of the tumor respectively. The results were then compared to the PBS and bacteria without construct receiving groups.