Affiliations: Instituto de Investigaciones Biomédicas Alberto
Sols. Consejo Superior de Investigaciones Científicas (CSIC)-Universidad
Autónoma de Madrid (UAM). Madrid, Spain
Note: [] Address for correspondence: Miguel Quintanilla Instituto de
Investigaciones Biomédicas Alberto Sols. Consejo Superior de
Investigaciones Científicas (CSIC)- Universidad Autónoma de
Madrid (UAM) Arturo Duperier 4 28029-Madrid, Spain
Note: []
Abstract: During malignant progression tumor cells acquire the ability to
invade surrounding tissues and metastasize to distant organs. In epithelial
tumors, malignancy correlates with loss of the epithelial phenotype and gain of
fibroblastic characteristics. The mouse skin system has been extensively used
to study molecular and cellular events leading to initiation, promotion and
progression of tumorigenesis. In the mouse skin carcinogenesis model, initiated
keratinocytes containing a carcinogen-induced H-Ras oncogene mutation give rise
to benign papillomas, some of which progress to squamous cell carcinomas. Late
stages of carcinogenesis are associated with the development of highly invasive
and metastatic spindle carcinomas. In vitro and in vivo studies using this and
other epithelial cell systems have shown that TGF-b1 induces the
squamous-spindle carcinoma transition, and that an activated H-Ras oncogene
cooperates with TGF-b1 to stimulate malignancy of carcinoma cells. Signaling
events regulating migratory and invasive cell responses are less well
characterized than those leading to uncontrolled cell proliferation. In this
article, we discuss possible signaling pathways involved in malignant
progression of mouse skin tumors.