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As the most common and aggressive primary malignant brain tumor, glioblastoma is still lacking a satisfactory curative approach. The standard management consisting of gross total resection followed by radiotherapy and chemotherapy with temozolomide only prolongs patients' life moderately. In recent years, many therapeutics have failed to give a breakthrough in GBM treatment. In the search for new treatment solutions, we became interested in the repurposing of existing medicines, which have established safety profiles. We focused on the possible implementation of well-known drugs, metformin, and arginine. Metformin is widely used in diabetes treatment, but arginine is mainly a cardiovascular protective drug. We evaluated the effects of metformin and arginine on total DNA methylation, as well as the oxidative stress evoked by treatment with those agents. In glioblastoma cell lines, a decrease in 5-methylcytosine contents was observed with increasing drug concentration. When combined with temozolomide, both guanidines parallelly increased DNA methylation and decreased 8-oxo-deoxyguanosine contents. These effects can be explained by specific interactions of the guanidine group with m5CpG dinucleotide. We showed that metformin and arginine act on the epigenetic level, influencing the foreground and potent DNA regulatory mechanisms. Therefore, they can be used separately or in combination with temozolomide, in various stages of disease, depending on desired treatment effects. [ABSTRACT FROM AUTHOR]

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Poor storability of recalcitrant seeds is due to their inability to tolerate low moisture content. Understanding the processes underlying their recalcitrance is a prerequisite to developing a maintenance strategy and prolonging their lifespan. Multiple studies have investigated the differences between orthodox (desiccation-tolerant) and recalcitrant (desiccation-sensitive) seeds. Information on epigenetic regulation, however, is lacking and thus limits our understanding of the processes defining the physiology of seeds. In the present comparative study, changes in the global levels of 5-methylcytosine (m5C) in orthodox and recalcitrant seeds of Acer platanoides L. and Acer pseudoplatanus L. were characterized during progressive stages of severe drying. Concomitant with their differential sensitivity to desiccation stress, we demonstrate variation in the response of embryonic axes and cotyledons to water deficit at the level of DNA methylation. Results indicate that desiccation-induced changes in m5C are both tissue and seed category-specific and are highly correlated with recalcitrant seed viability. Moreover, we demonstrate that m5C global changes in response to desiccation are not retained in DNA isolated from seedlings, except in seedlings that are derived from strongly desiccated orthodox seeds (moisture content of 3.5%). Finally, the potential utilization of m5C status as a universal seed viability marker is discussed. [ABSTRACT FROM AUTHOR]

The year 1961 went down in history with exceptional scientific achievements. On May 13, the journal Nature published two articles on the first isolation of messenger ribonucleic acid (mRNA), which is an intermediate product between a gene and a protein. Just two weeks later, on May 27, the first letter of the genetic code, phenylalanine, was discovered. These discoveries made it possible to understand how genetic information is encoded and processed, thus causing the dynamic development of molecular biology. The breakthroughs of 1961 concerned not only nucleic acids. On April 12, the first human, Yuri Gagarin, entered space. Eight years later, in 1969, Neil Armstrong made his first walk on the moon, uttering the famous phrase: It is a small step for man, but a great leap for humanity. The era of conquering and learning about the cosmos has begun, mainly motivated by the natural curiosity of man and the desire to learn about the surrounding reality. The environmental factors in space are very different from terrestrial conditions, which raises questions about their effects on living organisms. In search of answers, a variety of scientific research has been carried out at the International Space Station (ISS) for over twenty years. As space travel is set to become more common in the near future, detailed studies of the effects of long-term space missions on the human body are required. These studies are currently carried out, among others using molecular biology techniques that enable detailed analysis of nucleic acids and proteins, but not only. The breakthrough achievements of 1961 initiated the development both in the field of molecular biology and the science of space, thanks to which today, 60 years after those events, we can combine knowledge and technological achievements from both fields to analyze and understand changes at the molecular level that occur as a result of being in organisms in outer space.