Peptide-based biosensing approaches for targeting breast cancer-derived exosomes.

Exosomes are nanovesicles present in all the biological fluids, making them attractive as non-invasive biomarkers for diseases like cancer, among many others. However, exosomes are complex to separate and detect, requiring comprehensive molecular characterization for their routine use in diagnostics. This study explores the use of peptides as cost-effective and stable alternatives to antibodies for exosome binding. To achieve that, phage display technology was employed to select peptides with high specificity for target molecules in exosomes. Specifically, a selected peptide was evaluated for its ability to selectively bind breast cancer-derived exosomes. Proteomic analysis identified 38 protein candidates targeted by the peptide on exosome membranes. The binding of the peptide to breast cancer-derived exosomes was successfully demonstrated by flow cytometry and magneto-actuated immunoassays. Furthermore, an electrochemical biosensor was also tested for breast cancer-derived exosome detection and quantification. The peptide demonstrated effective binding to exosomes from aggressive cancer cell lines, offering promising results in terms of specificity and recovery. This research shows potential for developing rapid, accessible diagnostic tools for breast cancer, especially in low-resource healthcare settings.

Is the regulation by miRNAs of NTPDase1 and ecto-5'-nucleotidase genes involved with the different profiles of breast cancer subtypes?

Breast cancer (BC) is a public health problem worldwide, causing suffering and premature death among women. As a heterogeneous disease, BC-specific diagnosis and treatment are challenging. Ectonucleotidases are related to tumor development and their expression may vary among BC. miRNAs may participate in epigenetic events and may regulate ectonucleotidases in BC. This study aimed to evaluate the expression of ectonucleotidases according to BC subtypes and to predict if there is post-transcriptional regulation of them by miRNAs. MCF 10A (non-tumorigenic), MCF7 (luminal BC), and MDA-MB-231 (triple-negative BC - TNBC) breast cell lines were used and ENTPD1 (the gene encoding for NTPDase1) and NT5E (the gene encoding for ecto-5'-nucleotidase) gene expression was determined. Interestingly, the expression of ENTPD1 was only observed in MCF7 and NT5E was lower in MCF7 compared to MDA-MB-231 cell line. ATP, ADP, and AMP hydrolysis were observed on the surface of all cell lines, being higher in MDA-MB-231. Like qPCR, the activity of AMP hydrolysis was also lower in the MCF7 cells, which may represent a striking feature of this BC subtype. In silico analyses confirmed that the miRNAs miR-101-3p, miR-141-3p, and miR-340-5p were higher expressed in MCF7 cells and targeted NT5E mRNA. Altogether, data suggest that the regulation of NT5E by miRNAs in MCF7 lineage may direct the molecular profile of luminal BC. Thus, we suggest that the roles of ecto-5'-nucleotidase and the aforementioned miRNAs must be unraveled in TNBC to be possibly defined as diagnostic and therapeutic targets.

Ruthenium (II) complex cis-[RuII(ŋ2-O2CC7H7O2)(dppm)2]PF6-hmxbato induces ROS-mediated apoptosis in lung tumor cells producing selective cytotoxicity.

Ruthenium complexes have been extensively explored as potential molecules for cancer treatment. Considering our previous findings on the remarkable cytotoxic activity exhibited by the ruthenium (II) complex 3-hydroxy-4-methoxybenzoate (hmxbato)-cis-[RuII(ŋ2-O2CC7H7O2)(dppm)2]PF6 against Leishmania promastigotes and also the similar metabolic characteristics between trypanosomatids and tumor cells, the present study aimed to analyze the anticancer potential of hmxbato against lung tumor cells, as well as the partial death mechanisms involved. Hmxbato demonstrated selective cytotoxicity against A549 lung tumor cells. In addition, this complex at a concentration of 3.8 µM was able to expressively increase the generation of reactive oxygen species (ROS) in tumor cells, causing an oxidative stress that may culminate in: (1) reduction in cellular proliferation; (2) changes in cell morphology and organization patterns of the actin cytoskeleton; (3) cell arrest in the G2/M phase of the cell cycle; (4) apoptosis; (5) changes in the mitochondrial membrane potential and (6) initial DNA damage. Furthermore, we demonstrated that the induction of programmed cell death can occur by the intrinsic apoptotic pathway through the activation of caspases. It is also worth highlighting that hmxbato exhibited predominant actions on A549 tumor cells in comparison to BEAS-2B normal bronchial epithelium cells, which makes this complex an interesting candidate for the design of new drugs against lung cancer.

Gene surgery: Potential applications for human diseases.

Gene therapy became in last decade a new emerging therapeutic era showing promising results against different diseases such as cancer, cardiovascular diseases, diabetes, and neurological disorders. Recently, the genome editing technique for eukaryotic cells called CRISPR-Cas (Clustered Regulatory Interspaced Short Palindromic Repeats) has enriched the field of gene surgery with enhanced applications. In the present review, we summarized the different applications of gene surgery for treating human diseases such as cancer, diabetes, nervous, and cardiovascular diseases, besides the molecular mechanisms involved in these important effects. Several studies support the important therapeutic applications of gene surgery in a large number of health disorders and diseases including ß-thalassemia, cancer, immunodeficiencies, diabetes, and neurological disorders. In diabetes, gene surgery was shown to be effective in type 1 diabetes by triggering different signaling pathways. Furthermore, gene surgery, especially that using CRISPR-Cas possessed important application on diagnosis, screening and treatment of several cancers such as lung, liver, pancreatic and colorectal cancer. Nevertheless, gene surgery still presents some limitations such as the design difficulties and costs regarding ZFNs (Zinc Finger Nucleases) and TALENs (Transcription Activator-Like Effector Nucleases) use, off-target effects, low transfection efficiency, in vivo delivery-safety and ethical issues.