Identification of PHB2 as a Potential Biomarker of Luminal A Breast Cancer Cells Using a Cell-Specific Aptamer

Unlocking new frontiers: DNA nanotechnology's impact on acute kidney injury diagnosis and treatment

Acute kidney injury (AKI) serves as an independent risk factor for chronic kidney disease (CKD) and hastens its progression. However, effective early diagnosis and treatment methods for AKI are still limited in clinical practice. There is a pressing need to develop fast, effective, and noninvasive diagnostic methods for AKI, as well as treatments that reduce nephrotoxicity. DNA nanotechnology, utilizing the programmable properties of DNA to engineer nanostructures and nanodevices, has achieved significant advancements in disease diagnosis and treatment. The application of DNA nanotechnology for kidney disease, particularly AKI, has been increasingly explored. This review encompasses the advancement of rapid and highly sensitive detection methods for AKI biomarkers, alongside the development of targeted drug delivery systems to the kidneys. These innovations facilitate precise treatment while minimizing adverse drug effects. The review underscores the progress in employing DNA nanotechnology for AKI diagnosis and treatment. Initially, we examine DNA nanotechnology-based strategies for AKI diagnosis, with an emphasis on biomarker detection. Subsequently, we delve into the therapeutic applications of DNA nanotechnology in AKI, highlighting targeted drug delivery and reduced toxicity. Finally, we offer insights into the challenges and opportunities associated with the clinical application of DNA nanotechnology in AKI management.

Prohibitin 2 orchestrates long noncoding RNA and gene transcription to accelerate tumorigenesis

The spatial co-presence of aberrant long non-coding RNAs (lncRNAs) and abnormal coding genes contributes to malignancy development in various tumors. However, precise coordinated mechanisms underlying this phenomenon in tumorigenesis remains incompletely understood. Here, we show that Prohibitin 2 (PHB2) orchestrates the transcription of an oncogenic CASC15-New-Isoform 2 (CANT2) lncRNA and the coding tumor-suppressor gene CCBE1, thereby accelerating melanoma tumorigenesis. In melanoma cells, PHB2 initially accesses the open chromatin sites at the CANT2 promoter, recruiting MLL2 to augment H3K4 trimethylation and activate CANT2 transcription. Intriguingly, PHB2 further binds the activated CANT2 transcript, targeting the promoter of the tumor-suppressor gene CCBE1. This interaction recruits histone deacetylase HDAC1 to decrease H3K27 acetylation at the CCBE1 promoter and inhibit its transcription, significantly promoting tumor cell growth and metastasis both in vitro and in vivo. Our study elucidates a PHB2-mediated mechanism that orchestrates the aberrant transcription of lncRNAs and coding genes, providing an intriguing epigenetic regulatory model in tumorigenesis.

Selection of internalizing RNA aptamers into human breast cancer cells derived from primary sites

Breast cancer is the most common cancer in women. Although chemotherapy is still broadly used in its treatment, adverse effects remain a challenge. In this scenario, aptamers emerge as a promising alternative for theranostic applications. Studies using breast cancer cell lines provide useful information in laboratory and preclinical investigations, most of which use cell lines established from metastatic sites. However, these cell lines correspond to cell populations of the late stage of tumor progression. On the other hand, studies using breast cancer cells established from primary sites make it possible to search for new theranostic approaches in the early stages of the disease. Therefore, this work aimed to select RNA aptamers internalized by MGSO-3 cells, a human breast cancer cell line, derived from a primary site previously established in our laboratory. Using the Cell-Internalization SELEX method, we have selected two candidate aptamers (ApBC1 and ApBC2). We evaluated their internalization efficiencies, specificities, cellular localization by Reverse Transcription-qPCR (RT-qPCR) and confocal microscopy assays. The results suggest that both aptamers were efficiently internalized by human breast cancer cells, MACL-1, MDA-MB-231, and especially by MGSO-3 cells. Furthermore, both aptamers could effectively distinguish human breast cancer cells derived from normal human mammary cell (MCF 10A) and prostate cancer cell (PC3) lines. Therefore, ApBC1 and ApBC2 could be promising candidate molecules for theranostic applications, even in the early stages of tumor progression.

3D DNAzyme walker based electrochemical biosensor for attomolar level microRNA-155 detection

Herein, an ultrasensitive electrochemical biosensor for microRNA-155 (miR-155) detection based on the powerful catalytic and continuous walking signal amplification capability of 3D DNAzyme walker and the gold nanoparticles/graphene aerogels carbon fiber paper-based (AuNPs/GAs/CFP) flexible sensing electrode with excellent electrochemical performance was successfully constructed. In a proof-of-concept experiment, in the presence of miR-155, the DNAzyme strands anchored on the streptavidin-modified magnetic beads (MBs) silenced by locked strands can be activated, thus generating the walking arm of the 3D DNAzyme walker. Meanwhile, the substrate strands modified with Fe-MOF-NH2 nanoparticles were evenly distributed on the surface of MBs and served as tracks of the 3D DNAzyme walker. Once the DNAzyme strand was activated, the catalytic site in the substrate strand can be cleaved in the presence of Mn2+, and a large number of stumps modified with Fe-MOF-NH2 nanoparticles (output@Fe-MOF-NH2) will be generated during the continuous and efficient walking cleavage of the DNAzyme walker, driving the recognition-catalysis-release cycle process for signal amplification. Immediately afterwards, the signal was read out through the base complementary pairing of capture probe (PS) immobilized on the surface of the paper-based flexible sensing electrode AuNPs/GAs/CFP and signal probes output@Fe-MOF-NH2, thus achieving the quantitative detection of miR-155. Under optimal experimental conditions, the designed 3D DNAzyme walker-based biosensor exhibited a relatively lower limit of detection (LOD) of 56.23 aM, with a linear range of 100 aM to 100 nM. Overall, the proposed 3D DNAzyme walker biosensor exhibited good interference and reproducibility, demonstrating a promising future in the field of clinical disease diagnosis.

The application of Aptamer in biomarker discovery

Biomarkers are detectable molecules that can reflect specific physiological states of cells, organs, and organisms and therefore be regarded as indicators for specific diseases. And the discovery of biomarkers plays an essential role in cancer management from the initial diagnosis to the final treatment regime. Practically, reliable clinical biomarkers are still limited, restricted by the suboptimal methods in biomarker discovery. Nucleic acid aptamers nowadays could be used as a powerful tool in the discovery of protein biomarkers. Nucleic acid aptamers are single-strand oligonucleotides that can specifically bind to various targets with high affinity. As artificial ssDNA or RNA, aptamers possess unique advantages compared to conventional antibodies. They can be flexible in design, low immunogenicity, relative chemical/thermos stability, as well as modifying convenience. Several SELEX (Systematic Evolution of Ligands by Exponential Enrichment) based methods have been generated recently to construct aptamers for discovering new biomarkers in different cell locations. Secretome SELEX-based aptamers selection can facilitate the identification of secreted protein biomarkers. The aptamers developed by cell-SELEX can be used to unveil those biomarkers presented on the cell surface. The aptamers from tissue-SELEX could target intracellular biomarkers. And as a multiplexed protein biomarker detection technology, aptamer-based SOMAScan can analyze thousands of proteins in a single run. In this review, we will introduce the principle and workflow of variations of SELEX-based methods, including secretome SELEX, ADAPT, Cell-SELEX and tissue SELEX. Another powerful proteome analyzing tool, SOMAScan, will also be covered. In the second half of this review, how these methods accelerate biomarker discovery in various diseases, including cardiovascular diseases, cancer and neurodegenerative diseases, will be discussed.

Essential Protein PHB2 and Its Regulatory Mechanisms in Cancer

Prohibitins (PHBs) are a highly conserved class of proteins and have an essential role in transcription, epigenetic regulation, nuclear signaling, mitochondrial structural integrity, cell division, and cellular membrane metabolism. Prohibitins form a heterodimeric complex, consisting of two proteins, prohibitin 1 (PHB1) and prohibitin 2 (PHB2). They have been discovered to have crucial roles in regulating cancer and other metabolic diseases, functioning both together and independently. As there have been many previously published reviews on PHB1, this review focuses on the lesser studied prohibitin, PHB2. The role of PHB2 in cancer is controversial. In most human cancers, overexpressed PHB2 enhances tumor progression, while in some cancers, it suppresses tumor progression. In this review, we focus on (1) the history, family, and structure of prohibitins, (2) the essential location-dependent functions of PHB2, (3) dysfunction in cancer, and (4) the promising modulators to target PHB2. At the end, we discuss future directions and the clinical significance of this common essential gene in cancer.