The differential expression of long interspersed nuclear elements-1 as a marker for hypomethylation in Merkel cell carcinoma.

The protein long interspersed nuclear elements-1 (LINE-1) serves as a useful surrogate marker of global methylation but little is known for Merkel cell carcinoma. LINE-1 expression was found only in Merkel cell polyomavirus (MCPyV)-positive Merkel cell carcinomas but not in MCPyV-negative Merkel cell carcinomas, suggesting that epigenetic dysregulation may be associated with MCPyV expression.

Brain mast cell relationship to neurovasculature during development.

Mast cells, derived from the hematopoietic stem cell, are present in the brain from birth. During development, mast cells occur in two locations, namely the pia and the brain parenchyma. The current hypothesis regarding their origin states that brain mast cells (or their precursors) enter the pia and access the thalamus by traveling along the abluminal wall of penetrating blood vessels.