After 12 weeks, HE stain showed the typical TCCB (transitional cell carcinoma of the bladder) change appearance and focal under membrana mucosa, RG-7388 solubility dmso muscular layer infiltrate of tumor. It seems that the MNU bladder perfusion induced-cancer has organ specificity; and we did not find any adenocarcinoma or squamous cell carcinoma of the bladder histological changes. Therefore, MNU perfusion may represent an ideal approach for the establishment of animal models of bladder cancer for evaluating novel anti-cancer treatments. Targeted cancer gene therapy is an ideal treatment for eradicating and/or

limiting cancer growth and improving quality of life and survival rate of cancer patients. HSV-TK/GCV Adavosertib supplier system is one of the most commonly used suicide gene therapy systems. However, most studies have used viral expression vectors, such as adenoviral or retroviral vectors to achieve the TK gene expression. Although efficient, these viral delivery systems have their own limitations, such as host immune response, low titer, the limited host range, serum complement inactivation, and detrimental mutations caused by random integrations into the host genome [3, 16–19]. In this study, we explored the possible use of Bifidobacterium infantis as a tumor-targeting gene delivery vehicle in bladd cancer gene therapy. Bifidobacterium

infantis are gram-positive bacteria which are non-pathogenic and strictly anaerobic without internal and external toxin production. It has been reported that Bifidobacterium can inhibit tumor growth [9, 15, 20]. Yazawa et al confirmed that when mammary tumors induced in rats were injected with new Bifidobacterium via the tail vein, Bifidobacterium could propagate specifically in tumor tissuesproliferation, resulting in tumor tissue atrophy and

extending the survival of tumor-bearing rats [9, 15, 20]. It has also been reported that when Bifidobacterium expressing human endostatin were injected to tumor-bearing mice via the tail vein, the antitumor effect was improved than the prototype Bifidobacterium [5, 17, 19]. These reports indicate that Bifidobacterium can be used as a tumor-targeting vector for cancer gene therapy [2–5, 21]). We have demonstrated the successful use of a novel Bifidobacterium infantis-mediated tumor-targeting suicide gene therapy system in inhibiting bladder tumor growth. Our results also indicate that induced apoptosis may at least in part account for the anticancer activity of the BI-TK system. Apoptosis, also known as programmed cell death, refers to certain physiological or pathological conditions in which the end of active life is regulated by the activation of a set of apoptotic factors. In normal cells, apoptosis and proliferation coexist and maintain a dynamic equilibrium.