Science
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Some tissue types give rise to human cancers millions of times more often than other tissue types. Although this has been recognized for more than a century, it has never been explained. ⋯ The majority is due to "bad luck," that is, random mutations arising during DNA replication in normal, noncancerous stem cells. This is important not only for understanding the disease but also for designing strategies to limit the mortality it causes.
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Adipocytes have been suggested to be immunologically active, but their role in host defense is unclear. We observed rapid proliferation of preadipocytes and expansion of the dermal fat layer after infection of the skin by Staphylococcus aureus. ⋯ This host defense function was mediated through the production of cathelicidin antimicrobial peptide from adipocytes because cathelicidin expression was decreased by inhibition of adipogenesis, and adipocytes from Camp(-/-) mice lost the capacity to inhibit bacterial growth. Together, these findings show that the production of an antimicrobial peptide by adipocytes is an important element for protection against S. aureus infection of the skin.