Search

Background and aims: Breast cancer is one of the most common types of malignancy in women with morbidity and mortality (15.0%) in the world. The antitumor activity of azurin protein produced by Pseudomonas aeruginosa has been described before. Mammaglobin-A (MAM-A) protein is especially expressed in 40%-80% of breast cancer types and this protein is a very specific molecular marker for stimulating the immune system. Accordingly, this study investigated the effects of pBudCE4.1-azurin-MAM-A recombinant vector on the induction of the immune system in laboratory mice by the real-time polymerase chain reaction (PCR) method. Methods: The pBudCE4.1-azurin-MAM-A recombinant and empty vectors were purchased and then separately transformed into Escherichia coli for multiplying. Next, each plasmid was extracted and the accuracy of transformation was confirmed by the PCR. These recombinant and empty (control) vectors were separately infused into the thigh muscle of the animals and the healthy group was infused with phosphatebuffered saline. The infusion sites, blood specimens, as well as the serum of the animals were collected and examined by serological and molecular tests. Results: Molecular and serological studies showed that the serum and expression levels of IL-2, IL-6, IL-7, and IL-10 in infused mice with pBudCE4.1-azurin-MAM-A recombinant vector significantly increased compared to healthy animals and injected mice with an empty vector (P < 0.05). Conclusion: In general, the findings revealed that the pBudCE4.1-azurin-MAM-A recombinant vector can stimulate the immune system of the mouse by an increase in the expression levels of IL-2, IL-6, IL-7, and IL-10. Thus, it would be better to examine the effects of this recombinant vector as a DNA vaccine on the prevention and treatment of breast cancer. [ABSTRACT FROM AUTHOR]

In the present study, the simultaneous application of azurin gene of P. aeruginosa and MAM-A antigen on the induction of immune responses against breast cancer tumors was investigated in BALB/c mice. The pBudCE4.1-azurin-MAM-A recombinant vector was generated and prepared at a large scale. This recombinant vector alone or combined with chitosan nanoparticles was infused into the hip muscle of animals. Animals were divided into the "prevention" and "therapy" categories. The animals of prevention category were first, immunized by a recombinant vector and then exposed to chemical cancer inducers; while the animals in the therapy category were first treated with chemical compounds and then infused by a recombinant plasmid. The tumor tissues, infusion sites, and blood specimens were collected and examined by serological, molecular, and histological tests. The breast tumor incidence in the infused animals by recombinant plasmid alone or combined with nanoparticles (in both prevention and therapy categories) compared with infused mice by empty pBudCE4.1 vector was significantly decreased (p < 0.05). These results were supported by histological studies using H&E staining. The ELISA and q-real-time PCR techniques showed the range of IFN-γ, IL-12, IL-4, and IL-17A cytokines in the infused mice by recombinant vector alone or combined with nanoparticles compared to the healthy mice and infused animals by intact pBudCE4.1 were significantly increased (p < 0.05). Accordingly, the expression of the tumor markers CEA, Krt20, and Muc1 were significantly decreased in treated mice either by the sole recombinant vector or combined with nanoparticles (p < 0.05). These findings indicated that pBudCE4.1-azurin-MAM-A recombinant vector plays an essential role against the formation and expansion of breast tumors in the animal model. In addition, this recombinant vector is safe and has the proper ability to stimulate the immune system. In addition, the chitosan nanoparticle represents a promising adjuvant for DNA vaccine delivery, which improves the immune system stimulation and boosts the vaccine performance. [ABSTRACT FROM AUTHOR]