Membrane-Interacting DNA Nanotubes Induce Cancer Cell Death

Mechanisms of H2pmen-Induced cell death: Necroptosis and apoptosis in MDA cells, necrosis in MCF7 cells

Breast cancer is the second leading cause of cancer-related deaths in women around the world. Several cancer therapeutics have already been discovered and are being used to treat breast cancer. However, most of them cause severe side effects. H2pmen, a tetradentate ligand, was used in this study to investigate its cytotoxic effects on growth, viability, and induction of cell death in MCF7 and MDA cells. The cell viability was determined by treating cells with different concentrations of H2pmen. MTT assay was used to obtain an IC50, and the cells were then assayed for membrane damage, apoptotic induction, and metabolism. Protein expression of Bax, p53, Bcl2, and xIAP was identified using Western blot analysis. The gene expression of RIPK1, RIPK3, and MKLK was determined using qPCR. In MDA cells, H2pmen increases cytotoxicity, as evidenced by upregulated LDH and JC-10, and enhances apoptosis, indicated by upregulated caspase-3/7 and Bax. In contrast, MCF7 cells exhibit a more stable profile with downregulated LDH and Annexin V Activity. MCF7 cells also show reduced necroptosis and increased necrosis. These findings highlight that H2pmen induces varied cytotoxic effects across MDA and MCF7 cells, with MDA cells exhibiting more pronounced apoptosis and necroptosis alongside complex anti-apoptotic responses.

7-Geranyloxycinnamic Acid Isolated from Melicope lunu-ankenda Leaves Perturbs Colon Cancer and Breast Cancer Cell Lines' Growth via Induction of Apoptotic Pathway

Globally, breast cancer is the most prevalent form of cancer in women and there is a need for alternative therapies such as plant-derived compounds with low systemic toxicity and selective toxicity to cancer cells. The aim of this study is to assess the cytotoxicity effects of 7-geranyloxycinnamic acid isolated from leaves of Melicope lunu-ankenda, a traditional medicinal plant, on the human breast cancer cell lines. Dried leaf powder was used for the preparation of different crude extracts using different solvents of increasing order of polarity. The structure of the isolated compound from the petroleum ether extract was elucidated by ¹H and ¹³C NMR, LC-MS, and DIP-MS spectroscopy. The cytotoxic activity of the crude extract and 7-geranyloxycinnamic acid analyzed using MTT assay. Apoptotic analysis was evaluated using Annexin V-PI staining, AO/PI staining, intracellular ROS measurement, and measurement of activities of caspases 3/7, 8, and 9. Crude extracts and the isolated pure compound showed significant cytotoxicity against tested cancer cell lines. 7-geranyloxycinnamic acid was found to exert significant cytotoxic effects against breast cancer cell lines such as the MCF-7 and MDA-MB-231 cell lines. The cytotoxic effects are attributed to its ability to induce apoptosis via accumulation of ROS and activation of caspases in both breast cancer cell lines. The pure compound, 7-geranyloxycinnamic acid isolated from the leaves of M. lunu-ankenda, can exert significant cytotoxic effects against breast cancer cell lines without affecting the normal cells.

DNA-Based Nanomaterials as Drug Delivery Platforms for Increasing the Effect of Drugs in Tumors

DNA nanotechnology has significantly advanced and might be used in biomedical applications, drug delivery, and cancer treatment during the past few decades. DNA nanomaterials are widely used in biomedical research involving biosensing, bioimaging, and drug delivery since they are remarkably addressable and biocompatible. Gradually, modified nucleic acids have begun to be employed to construct multifunctional DNA nanostructures with a variety of architectural designs. Aptamers are single-stranded nucleic acids (both DNAs and RNAs) capable of self-pairing to acquire secondary structure and of specifically binding with the target. Diagnosis and tumor therapy are prospective fields in which aptamers can be applied. Many DNA nanomaterials with three-dimensional structures have been studied as drug delivery systems for different anticancer medications or gene therapy agents. Different chemical alterations can be employed to construct a wide range of modified DNA nanostructures. Chemically altered DNA-based nanomaterials are useful for drug delivery because of their improved stability and inclusion of functional groups. In this work, the most common oligonucleotide nanomaterials were reviewed as modern drug delivery systems in tumor cells.

Ultrasensitive and multiplexed miRNA detection system with DNA-PAINT

MiRNAs hold great potential as biomarkers for the early detection and monitoring of diseases based on their differential expression profiles. Therefore, the sensitive, specific and accurate detection of miRNAs represents an emerging new tool to improve diagnosis and treatment of several diseases, cancer in particular. DNA origami-based miRNA detection is particularly advantageous as it allows to incorporate multiple attachment sites to capture different target miRNAs at the nanoscale. In this work, we present a DNA origami nanoarray system providing distance-dependent recognition of miRNAs by applying super-resolution microscopy technique; DNA-PAINT (point accumulation for imaging in nanoscale topography). The sensor can detect up to 4 miRNAs either separately or in combination based on the relative distance to the boundary markers on the structure using a single imager strand. The detection is highly sensitive, with a limit of detection down to the low femtomolar range (11 fM - 388 fM) and has a large dynamic range up to 10 nM without need for amplification. Moreover, our detection system can discriminate single base mismatches with low false positive rates. Using our strategy, we demonstrate the detection of endogenous miRNAs from cell extracts of cancer cell lines and plasma from breast cancer patients. Overall, we developed an ultrasensitive and amplification-free, DNA-PAINT imaging-based miRNA detection method using DNA origami nanoarray system for the detection of breast-cancer associated miRNAs which potentially provides a sensitive and accurate alternative to the current multiplexed diagnostic technologies.

Functionalized-DNA nanostructures as potential targeted drug delivery systems for cancer therapy

Seeman's pioneer idea has led to the foundation of DNA nanostructures, resulting in a remarkable advancement in DNA nanotechnology. Over the last few decades, remarkable advances in drug delivery techniques have resulted in the self-assembly of DNA for encapsulating candidate drug molecules. The nuclear targeting capability of DNA nanostructures is lies within their high spatial addressability and tremendous potential for active targeting. However, effective programming and assembling those DNA molecules remains a challenge, making the path to DNA nanostructures for real-world applications difficult. Because of their small size, most nanostructures are self-capable of infiltrating into the tumor cellular environment. Furthermore, to enable controlled and site-specific delivery of encapsulated drug molecules, DNA nanostructures are functionalized with special moieties that allow them to bind specific targets and release cargo only at targeted sites rather than non-specific sites, resulting in the prevention/limitation of cellular toxicity. In light of this, the current review seeks to shed light on the versatility of the DNA molecule as a targeting and encapsulating moiety for active drugs in order to achieve controlled and specific drug release with spatial and temporal precision. Furthermore, this review focused on the challenges associated with the construction of DNA nanostructures as well as the most recent advances in the functionalization of DNA nanostructures using various materials for controlled and targeted delivery of medications for cancer therapy.

Digging into the biophysical features of cell membranes with lipid-DNA conjugates

Lipid-DNA conjugates have emerged as highly useful tools to modify the cell membranes. These conjugates generally consist of a lipid anchor for membrane modification and a functional DNA nanostructure for membrane analysis or regulation. There are several unique properties of these lipid-DNA conjugates, especially including their programmability, fast and efficient membrane insertion, and precise sequence-specific assembly. These unique properties have enabled a broad range of biophysical applications on live cell membranes. In this review, we will mainly focus on recent tremendous progress, especially during the past three years, in regulating the biophysical features of these lipid-DNA conjugates and their key applications in studying cell membrane biophysics. Some insights into the current challenges and future directions of this interdisciplinary field have also been provided.