Human milk banks in the response to COVID-19: a statement of the regional human milk bank network for Southeast Asia and beyond.

BACKGROUND: The World Health Organization (WHO) recommendations on infant feeding in the context of COVID-19 uphold standing recommendations for breastfeeding, non-separation, and skin-to-skin contact, including the use of donor human milk when mother's own milk is not available. INSUFFICIENT GUIDANCE ON THE USE OF DONOR HUMAN MILK AND THE ROLE OF HUMAN MILK BANKS IN THE PANDEMIC RESPONSE: COVID-19 clinical management guidelines in seven countries in Southeast Asia are not aligned with WHO recommendations despite the lack of evidence of transmission through either breastmilk or breastfeeding. The use of safe donor human milk accessed through human milk banks is also insufficiently recommended, even in countries with an existing human milk bank, leading to a gap in evidence-based management of COVID-19. This highlights long-standing challenges as well as opportunities in the safe, equitable, and resilient implementation of human milk banks in the region. CONCLUSIONS: This statement reflects the expert opinion of the Regional Human Milk Bank Network for Southeast Asia and Beyond on the need to revisit national guidelines based on the best evidence for breastfeeding during the COVID-19 pandemic, to incorporate human milk bank services in national obstetric and newborn care guidelines for COVID-19 where possible, and to ensure that operations of human milk banks are adapted to meet the needs of the current pandemic and to sustain donor human milk supply in the long-term. The Network also recommends sustained engagement with the global human milk bank community.

Involvement of the P2X7 receptor in the migration and metastasis of tamoxifen-resistant breast cancer: effects on small extracellular vesicles production.

Tamoxifen (TAM) is the standard anti-hormonal therapy for estrogen receptor-positive breast cancer. However, long-term TAM therapy can make acquisition of TAM resistance and there are still no solutions to treat TAM-resistant breast cancer. In this study, we found that protein and mRNA expression of the P2X purinoreceptor 7 (P2X7) was higher in tamoxifen resistant MCF-7 (TAMR-MCF-7) cells than in control MCF-7 cells. P2X7 inhibition potently inhibited the migration of TAMR-MCF-7 cells and the liver metastasis burden of TAMR-MCF-7 cells in the spleen-liver metastasis experiment. However, the P2X7 antagonist did not affect protein expression of matrix metalloproteinase (MMP)-2, MMP-9, and epithelial-mesenchymal transition markers. Here our data indicate a link between small extracellular vesicles (sEV) and P2X7, and suggest a new mechanism of metastasis in TAM-resistant breast cancer cells through P2X7 receptors. The migration of TAMR-MCF-7 cells was increased in a concentration-dependent manner by purified sEV treatment. The number of secreted sEVs and the protein levels of CD63 in TAMR-MCF-7 cells were decreased by the P2X7 antagonist, showing that P2X7 influences the production of sEV. Our results suggest that inhibiting the P2X7 could be considered for metastasis prevention in TAM-resistant cancer patients.