Medical Bulletin 29/October/2025

mRNA COVID-19 vaccines may help immunotherapy by boosting the immune system’s ability to recognize and attack cancer cells. When given around the time patients start checkpoint inhibitor treatments—drugs that “unmask” cancer for the immune system—these vaccines act like an alarm, alerting immune cells to target tumors more effectively. This study showed that cancer patients vaccinated within 100 days of starting immunotherapy were twice as likely to survive three years later.

The research further suggests that mRNA vaccines “train” the immune system, strengthening its ability to recognize and attack cancer cells, especially when combined with checkpoint inhibitors. These immunotherapy drugs help reveal cancer cells that evade immune detection. Early animal studies and clinical observations support the idea that mRNA vaccines act as a “wake-up call” for the immune system, enhancing tumor recognition and destruction. Lab studies showed that vaccination raised PD-L1 protein on tumors, which checkpoint inhibitors then block, allowing the immune system to target cancer more effectively.

The finding builds on earlier work by University of Florida researchers who initially developed personalized mRNA cancer vaccines and noticed that mRNA vaccines for infectious diseases might have similar effects. These insights are leading to plans for a Phase III trial testing mRNA vaccines as routine complements to immunotherapy, especially for “cold” tumors that usually resist treatment. In advanced lung and metastatic melanoma cancers, vaccinated patients had notably longer survival times, sometimes nearly doubling expected outcomes.

Lead researcher Dr. Adam Grippin called the results “extraordinary,” highlighting the potential for repurposing mRNA vaccine technology to transform cancer therapy worldwide. While more research is needed to verify mechanisms and optimize treatment, this innovative strategy offers hope for better outcomes and new avenues in oncologic care.

Reference: Grippin, A.J., Marconi, C., Copling, S. et al. SARS-CoV-2 mRNA vaccines sensitize tumours to immune checkpoint blockade. Nature (2025). https://doi.org/10.1038/s41586-025-09655-y

Eating peanuts during pregnancy may affect how child's genes respond to breastfeeding: Study

Scientists at Syracuse University studied how eating peanuts during pregnancy and breastfeeding might affect the DNA methylation (DNAm) patterns of children, potentially influencing their brain development and inflammation response. They recruited 35 children aged 2-7 and gathered data on maternal peanut butter and peanut consumption during pregnancy and lactation, breastfeeding duration, demographics, and child saliva samples for DNAm analysis.

DNAm-an epigenetic mechanism-affects how genes related to neurodevelopment (like BDNF) and inflammation (IL6 and others) are expressed. The study was published in the journal Food Science & Nutrition.

Researchers at Syracuse University studied how eating peanuts and peanut butter during pregnancy and breastfeeding affects children's DNA methylation, which influences gene activity. They recruited 35 children aged 2-7 and collected saliva samples for DNA testing along with questionnaires on maternal diet, breastfeeding, family background, and child experiences. They analyzed methylation changes in genes linked to brain development and inflammation. Results showed that children whose mothers consumed both peanuts and peanut butter during pregnancy had different DNA methylation patterns related to breastfeeding duration, suggesting maternal diet can shape a child's gene expression and health.

The study found that when mothers ate both peanuts and peanut butter during pregnancy, longer breastfeeding was linked to increased DNA methylation in key brain development genes (BDNF and BDNF-AS), which may affect gene regulation positively. However, when mothers consumed only peanut butter, longer breastfeeding was associated with decreased methylation, possibly increasing gene expression. Maternal peanut intake also influenced inflammation-related DNA changes depending on household income and race. These effects may reflect nutritional differences between whole peanuts and peanut butter.

Additional influences included household income and race, which interacted with maternal peanut intake to affect DNA methylation of inflammation-related genes, possibly reflecting differences in nutrient content or allergenicity between peanut products.

Though the small sample size limits generalization, this study suggests that peanut consumption during pregnancy and lactation can epigenetically “prime” children’s genes, affecting brain development and inflammation regulation. More research is needed to better understand these relationships and how maternal diet might set the stage for offspring health through epigenetic modulation.

Reference: Garay JL, Voss MA, Pilkay SR (2025). Effects of Maternal Peanut Intake and Breastfeeding Duration on Offspring DNA Methylation. Food Science & Nutrition, 13(10), e71129. DOI: 10.1002/fsn3.71129, https://onlinelibrary.wiley.com/doi/10.1002/fsn3.71129

Scientists discover unexpected link between gray hair and cancer risk

Scientists have discovered how DNA damage in stem cells can determine whether hair turns gray or becomes vulnerable to cancer. A new study published on October 6, 2025, in Nature Cell Biology by researchers from The University of Tokyo explains how melanocyte stem cells (McSCs) in hair follicles respond differently to various forms of DNA stress. The work, led by Professor Emi Nishimura and Assistant Professor Yasuaki Mohri, reveals that the same population of stem cells can either stop regenerating, leading to graying hair, or expand abnormally, increasing cancer risk.

Melanocyte stem cells reside in the bulge-sub-bulge area of hair follicles and serve as the source for pigment-producing melanocytes that give hair its color. The researchers aimed to understand how these stem cells handle DNA damage accumulated over time from internal and environmental sources such as UV exposure or chemical carcinogens, both of which influence tissue aging and cancer development.

Using long-term lineage tracing and gene expression profiling in mouse models, the researchers analyzed how McSCs reacted to DNA double-strand breaks and exposure to carcinogens. They induced DNA damage through controlled radiation and chemical exposure, tracking how individual stem cells changed over time. Molecular analyses focused on the activation of stress response pathways, particularly the p53-p21 system, to determine how cells decide between differentiation or renewal.

When McSCs experienced double-strand DNA breaks, they entered a process called senescence-coupled differentiation, or seno-differentiation. In this state, the cells permanently matured and exited the stem cell cycle, leading to pigment loss and hair graying. However, when exposed to carcinogens such as 7,12-dimethylbenz(a)anthracene or ultraviolet B rays, this protective mechanism was bypassed. Instead, the damaged cells continued to proliferate with assistance from KIT ligand signals released by nearby tissues. This unchecked renewal drove clonal expansion, setting the stage for potential melanoma formation.

According to Nishimura, the results show that stem cells can follow opposing fates—protective aging or malignant growth—depending on the stress type and surrounding tissue signals. These discoveries bridge a vital gap between aging and cancer research, revealing how cellular self-destruction helps maintain tissue health and prevent tumor formation.

Reference: Yasuaki Mohri, Jialiang Nie, Hironobu Morinaga, Tomoki Kato, Takahiro Aoto, Takashi Yamanashi, Daisuke Nanba, Hiroyuki Matsumura, Sakura Kirino, Kouji Kobiyama, Ken J. Ishii, Masahiro Hayashi, Tamio Suzuki, Takeshi Namiki, Jun Seita, Emi K. Nishimura. Antagonistic stem cell fates under stress govern decisions between hair greying and melanoma. Nature Cell Biology, 2025; 27 (10): 1647 DOI: 10.1038/s41556-025-01769-9