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.
- Klíčová slova
- Blood-cerebrospinal fluid barrier, Blood-spinal cord barrier, Blood–brain barrier, Brain Metastasis, Cancer,
- MeSH
- hematoencefalická bariéra * metabolismus patologie MeSH
- lidé MeSH
- metastázy nádorů MeSH
- nádorové cirkulující buňky patologie MeSH
- nádory mozku * sekundární metabolismus patologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
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.
- Klíčová slova
- HPV integration, RT‐LAMP, cervical cancer, electrochemistry, human papillomavirus,
- MeSH
- biosenzitivní techniky metody MeSH
- DNA vazebné proteiny genetika MeSH
- DNA virů genetika MeSH
- elektrochemické techniky * metody MeSH
- genom virový MeSH
- infekce papilomavirem * virologie MeSH
- integrace viru * genetika MeSH
- lidé MeSH
- lidský papilomavirus 16 * genetika MeSH
- messenger RNA * genetika MeSH
- nádory děložního čípku * virologie MeSH
- onkogenní proteiny virové * genetika MeSH
- Papillomavirus E7 - proteiny * genetika MeSH
- progrese nemoci MeSH
- RNA virová genetika MeSH
- techniky amplifikace nukleových kyselin metody MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA vazebné proteiny MeSH
- DNA virů MeSH
- E2 protein, Human papillomavirus type 16 MeSH Prohlížeč
- messenger RNA * MeSH
- oncogene protein E7, Human papillomavirus type 16 MeSH Prohlížeč
- onkogenní proteiny virové * MeSH
- Papillomavirus E7 - proteiny * MeSH
- RNA virová MeSH
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.
- Klíčová slova
- CRISPR-Cas, human papillomavirus, isothermal amplification techniques, lab-on-a-chip, lateral flow assay, nanomaterials,
- MeSH
- infekce papilomavirem * komplikace MeSH
- lidé MeSH
- lidské papilomaviry MeSH
- nádory děložního čípku * MeSH
- Papillomaviridae genetika MeSH
- technologie MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Electrochemical (EC) detection of DNA biomarkers represents an interesting tool in molecular oncology due to its sensitivity, simplicity, low cost or rapid times of measurement. However, majority of EC assays, same as most optical-based techniques, require preceding DNA extraction step to remove other cellular components, making these assays more laborious and time-consuming. One option to circumvent this is to use LAMP (loop-mediated amplification), an isothermal amplification technique that can amplify DNA directly in crude lysates in a short time at a constant temperature. Here, we coupled the LAMP reaction with EC readout to detect DNA from the two most common oncogenic human papillomavirus (HPV) types that cause cervical cancer in women, i.e. HPV 16 and HPV 18, directly in crude lysates without a need for DNA extraction step. We show that in crude lysates, the LAMP reaction was superior to PCR, with very good selectivity on a panel of cancer cell lines and with high sensitivity, enabling detection of HPV DNA from as few as 10 cells. As a proof of principle, we applied the assay to nineteen clinical samples both from uninfected women and from women suffering from cervical precancerous lesions caused by HPV 16 or HPV 18 genotypes. Clinical samples were simply boiled for 5 min in homogenization buffer without DNA extraction step, and amplified with LAMP. We obtained excellent concordance of our assay with PCR, reaching 100% sensitivity for both genotypes, 81.82% specificity for HPV 16 and 94.12% specificity for HPV 18. Proposed assay could be a straightforward, simple, rapid and sensitive alternative for early diagnostics of precancerous cervical lesions.
- Klíčová slova
- Cervical cancer, Crude lysate, Electrochemistry, HPV, LAMP amplification,
- MeSH
- biotest MeSH
- infekce papilomavirem * diagnóza MeSH
- lidé MeSH
- lidský papilomavirus 18 genetika MeSH
- Papillomaviridae genetika MeSH
- techniky amplifikace nukleových kyselin MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
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.
- Klíčová slova
- DNA biosensor, DNA methylation, bisulfite conversion, epigenetic modification, restriction enzyme, tumor, tumorigenesis,
- MeSH
- 5-methylcytosin metabolismus MeSH
- biosenzitivní techniky metody MeSH
- epigeneze genetická genetika MeSH
- lidé MeSH
- metylace DNA genetika fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- 5-methylcytosin MeSH
To investigate glycans' influence on the behavior of glycoproteins on charged surfaces, avidin and its nonglycosylated and neutralized version neutravidin were studied by label-free chronopotentiometric stripping (CPS) analysis and alternating current voltammetry combined with a mercury electrode. Despite neutravidin's and avidin's similar size and structure, their CPS responses differed due to the different amounts of catalytically active free amino groups of lysine and arginine residues. Acetylation of the proteins resulted in the suppression of their CPS responses by almost four times for avidin and by about 50 % for neutravidin, respectively. On the other hand, the presence of glycans in the acetylated avidin induced about 30 % higher chronopotentiometric response compared to the acetylated neutravidin. We suggest that the presence, size and composition of the glycans influenced the CPS signal due to differences in the orientation at a charged surface. The obtained results can be utilized in glycoprotein research.
