DNA methylation, i.e., addition of methyl group to 5′-carbon of cytosine residues in CpG dinucleotides, is an important epigenetic modification regulating gene expression, and thus implied in many cellular processes. Deregulation of DNA methylation is strongly associated with onset of various diseases, including cancer. Here, we review how DNA methylation affects carcinogenesis process and give examples of solid tumors where aberrant DNA methylation is often present. We explain principles of methods developed for DNA methylation analysis at both single gene and whole genome level, based on (i) sodium bisulfite conversion, (ii) methylation-sensitive restriction enzymes, and (iii) interactions of 5-methylcytosine (5mC) with methyl-binding proteins or antibodies against 5mC. In addition to standard methods, we describe recent advances in next generation sequencing technologies applied to DNA methylation analysis, as well as in development of biosensors that represent their cheaper and faster alternatives. Most importantly, we highlight not only advantages, but also disadvantages and challenges of each method.

Persistent infection with high‐risk types of human papillomaviruses (HPV) is a major cause of cervical cancer, and an important factor in other malignancies, for example, head and neck cancer. Despite recent progress in screening and vaccination, the incidence and mortality are still relatively high, especially in low‐income countries. The mortality and financial burden associated with the treatment could be decreased if a simple, rapid, and inexpensive technology for HPV testing becomes available, targeting individuals for further monitoring with increased risk of developing cancer. Commercial HPV tests available in the market are often relatively expensive, time‐consuming, and require sophisticated instrumentation, which limits their more widespread utilization. To address these challenges, novel technologies are being implemented also for HPV diagnostics that include for example, isothermal amplification techniques, lateral flow assays, CRISPR‐Cas‐based systems, as well as microfluidics, paperfluidics and lab‐on‐a‐chip devices, ideal for point‐of‐care testing in decentralized settings. In this review, we first evaluate current commercial HPV tests, followed by a description of advanced technologies, explanation of their principles, critical evaluation of their strengths and weaknesses, and suggestions for their possible implementation into medical diagnostics.

Brain metastases (BMs) are the most common intracranial tumors in adults and occur 3–10 times more frequently than primary brain tumors. Despite intensive multimodal therapies, including resection, radiotherapy, and chemotherapy, BMs are associated with poor prognosis and remain challenging to treat. BMs predominantly originate from primary lung (20–56%), breast (5–20%), and melanoma (7–16%) tumors, although they can arise from other cancer types less frequently. The metastatic cascade is a multistep process involving local invasion, intravasation into the bloodstream or lymphatic system, extravasation into normal tissue, and colonization of the distal site. After reaching the brain, circulating tumor cells (CTCs) breach the blood–brain barrier (BBB). The selective permeability of the BBB poses a significant challenge for therapeutic compounds, limiting the treatment efficacy of BMs. Understanding the mechanisms of tumor cell interactions with the BBB is crucial for the development of effective treatments. This review provides an in-depth analysis of the brain barriers, including the BBB, blood-spinal cord barrier, blood-meningeal barrier, blood-arachnoid barrier, and blood-cerebrospinal fluid barrier. It explores the molecular and cellular components of these barriers and their roles in brain metastasis, highlighting the importance of this knowledge for identifying druggable targets to prevent or limit BM formation.

Human papillomaviruses (HPVs) represent a diverse group of double‐stranded DNA viruses associated with various types of cancers, notably cervical cancer. High‐risk types of HPVs exhibit their oncogenic potential through the integration of their DNA into the host genome. This integration event contributes significantly to genomic instability and the progression of malignancy. However, traditional detection methods, such as immunohistochemistry or PCR‐based assays, face inherent challenges, and thus alternative tools are being developed to fasten and simplify the analysis. Our study introduces an innovative biosensing platform that combines loop‐mediated amplification with electrochemical (EC) analysis for the specific detection of HPV16 integration. By targeting key elements like the E7 mRNA, a central player in HPV integration, and the E2 viral gene transcript lost upon integration, we show clear distinction between episomal and integrated forms of HPV16. Our EC data confirmed higher E7 expression in HPV16‐positive cell lines having integrated forms of viral genome, while E2 expression was diminished in cells with fully integrated genomes. Moreover, we revealed distinct expression patterns in cervical tissue of patients, correlating well with digital droplet PCR, qRT‐PCR, or immunohistochemical staining. Our platform thus offers insights into HPV integration in clinical samples and facilitates further advancements in cervical cancer research and diagnostics.