Immunogenic analysis of epitope-based vaccine candidate induced by photodynamic therapy in MDA-MB-231 triple-negative breast cancer cells.

BACKGROUND: Photodynamic therapy (PDT) is used to treat tumors through selective cytotoxic effects. PDT induces damage-associated molecular patterns (DAMPs) expression, which can cause an immunogenic death cell (IDC). In this study we identified potential immunogenic epitopes generated by PDT on triple-negative breast cancer cell line (MDA-MB-231). METHODS: MDA-MB-231 cells were exposed to PDT using ALA (160 µg/mL)/630 nm at 8 J/cm2. Membrane proteins were extracted and separated by 2D PAGE. Proteins overexpressed were identified by LC-MS/MS and analyzed in silico through a peptide-HLA docking in order to identify the epitopes with more immunogenicity and antigenicity properties, as well as lower allergenicity and toxicity activity. The selected peptides were evaluated in response to macrophage activation and cytokine release by flow cytometry. RESULTS: Differential proteins were overexpressed in the cells treated with PDT. A group of 16 peptides were identified from them, established in a rigorous selection by measuring antigenicity, immunogenicity, allergenicity, and toxicity in silico. The final selection was based on molecular dynamics, where 2 peptides showed the highest stability regarding to the RMSD value. These peptides were obtained from the proteins calreticulin and HSP90. The cytokine analysis evidenced macrophage activation by the releasing of TNF. CONCLUSION: Two peptides were identified from calreticulin and HSP90; proteins induced by PDT in MDA-MB-231 cells. Both epitopes showed immunogenic potential as a peptide-based vaccine for triple-negative breast cancer.

Use of AKR1C1 and TKTL1 in the Diagnosis of Low-grade Squamous Intraepithelial Lesions from Mexican Women.

BACKGROUND/AIM: To determine the differential protein profiles of cervical cancer cell lines in order to find potential targets that can be used as biomarkers in low-grade squamous intraepithelial lesions (LSIL) diagnosis. MATERIALS AND METHODS: Proteomic analysis was performed on cervical cancer cell lines by 2D electrophoresis and liquid chromatography-mass spectrometry. Biomarker validation was performed in histological samples by immunofluorescence. RESULTS: Aldo-keto reductase C1 (AKR1C1) and transketolase-like 1 (TKTL1) proteins were selected as biomarkers and their expression was increased in samples with LSIL diagnosis. TKTL1 in combination with AKR1C1 increased sensitivity and specificity to 75% and 66%, respectively, with an area under curve of 0.76 in receiver operating characteristics curve analysis. CONCLUSION: AKR1C1 and TKTL1 showed potential as biomarkers for diagnosis of LSIL in Mexican women, with similar sensitivity and specificity to the biomarkers used in clinical trials for diagnosis of LSIL.