basement membrane

Definition : The basement membranes are a specialized extracellular matrix underlying all epithelia, endothelia and surrounding muscle, adipose and Schwann cells.

In the embryo, the basal membrane is the first organized extracellular matrix to appear, underlying the trophodermal epithelia in the blastocyst.

Major constituents

 laminins
 collagen IV
 perlecan
 nidogen

Basement membranes and cancer

Basement membranes can be a barrier to tumour growth, but basement membrane molecules, including laminins, are also important autocrine factors produced by cancers to promote tumorigenesis.

Pathology

 basement membrane thickening

References

 Kalluri R. Basement membranes: structure, assembly and role in tumour angiogenesis. Nat Rev Cancer. 2003 Jun;3(6):422-33. PMID: 12778132