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Signal Transduction and Targeted Therapy May 2020Although targeted therapy has been extensively investigated for breast cancers, a molecular target with broad application is currently unavailable due to the high...
Although targeted therapy has been extensively investigated for breast cancers, a molecular target with broad application is currently unavailable due to the high heterogeneity of these cancers. Mammaglobin-A (Mam-A), which is overexpressed in most breast carcinomas, has been proposed as a promising target. However, the lack of specific targeting moieties due to uncertain binding epitopes hampers further translational study. Here, seven potential epitopes of Mam-A were disclosed, and a unique epitope was then identified in most types of breast cancers, despite the genotypic heterogeneity. With phage display technology, the epitope was determined to be N-terminal amino acids 42-51 of Mam-A (N). Then, the N epitope-specific monoclonal antibody, mAb785, was conjugated to poly lactic-co-glycolic acid (PLGA) nanoparticles loaded with therapeutic agents, thereby enhancing the drug uptake and therapeutic efficacy in different genotypes of breast cancers. The computer simulation of the N epitope and the mAb785 structures, as well as their interactions, further revealed the specific targeting mechanism of the mAb785-conjugated nanoparticles to breast cancers.
Topics: Antibodies, Monoclonal; Antineoplastic Agents, Immunological; Breast Neoplasms; CD8-Positive T-Lymphocytes; Cell Line, Tumor; Epitopes; Female; Humans; Mammaglobin A; Nanoparticles; Neoplasm Proteins; T-Lymphocytes, Cytotoxic
PubMed: 32467564
DOI: 10.1038/s41392-020-0183-1 -
Oncology Letters Dec 2019Previous phase I DNA-vaccine based clinical trials using Mammaglobin-A (Mam-A), a human breast tumor associated antigen (TAA), demonstrated that this agent was safe and...
Previous phase I DNA-vaccine based clinical trials using Mammaglobin-A (Mam-A), a human breast tumor associated antigen (TAA), demonstrated that this agent was safe and efficient at treating patients with stage IV breast cancer. The long-term success of cancer vaccines is limited by the diminished expression of human leukocyte antigen (HLA) class I molecules in the tumor microenvironment. The current study assessed the impact of various selenocompounds on the expression of HLA class I molecules in THP-1 cells, an apparent proficient antigen that presents a human monocyte-like cell line, and their eventual activation of MamA2.1 (HLA-A2 immunodominant epitope of Mam-A) specific cytotoxic CD8 T lymphocytes (CTLs). The results revealed that, following treatment with methylselenol producing compounds [methylselenic acid (MSA) and dimethylselenide (DMDSe)], the expression of HLA class-I was increased and components involved with the antigen presentation machinery of THP-1 cells were upregulated. Furthermore, CTLs activated by MamA2.1 peptide presenting THP-1 cells, pre-treated with MSA and DMDSe, demonstrated an enhanced cytotoxicity in HLA-A2/Mam-A AU565 and UACC-812 breast cancer cell lines when compared with CTLs activated by THP-1 cells without drug treatment. However, no significant cytotoxicity was observed under similar conditions in HLA-A2/Mam-A MCF-7 and MDA-MB-231 breast cancer cell lines. The results indicated that treatment with methylselenol producing compounds retained antigen-dependent activation of CD8 T cells. The data of the current study demonstrated that MSA and DMDSe potentiated effector cytotoxic responses following TAA specific activation of CTLs, indicating their future role as vaccine adjuvants in cancer immunotherapy.
PubMed: 31807192
DOI: 10.3892/ol.2019.11010 -
3 Biotech Jul 2019In the present study, the simultaneous application of gene of and - antigen on the induction of immune responses against breast cancer tumors was investigated in...
In the present study, the simultaneous application of gene of and - 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 (< 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 (< 0.05). Accordingly, the expression of the tumor markers , , and were significantly decreased in treated mice either by the sole recombinant vector or combined with nanoparticles (< 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.
PubMed: 31245235
DOI: 10.1007/s13205-019-1804-7