Some Thing New I have found Out about Melanoma!!!! .. Jim Breitfeller

Excerpt from:

"Melanoma invasion – current knowledge and future
directions"


Cedric Gaggioli and Erik Sahai*
Tumour Cell Biology Laboratory, Cancer Research UK, London
Research Institute, London, UK
*Address correspondence to E. Sahai,
e-mail: erik.sahai@cancer.org.uk


"This has dramatic implications
for any attempts to translate any in vitro findings
regarding melanoma cell line invasion into the clinical
situation. The mode of invasion affects the sensitivity of
different cell lines to blockade of MMP function; generally
cells invading with a rounded morphology characteristic
of strong cortical acto-myosin contractility are not
sensitive to MMP inhibition because they can use force
mediated matrix remodelling in place of proteolysis
(Wyckoff et al., 2006)."

"However, cells that do not generate
such high levels of force may be more dependent on
MMP function. When this was directly tested using
WM266.4 cells it was observed that the cells actually
converted to a more rounded MMP independent mode
of invasion (Sahai and Marshall, 2003). Friedl and colleagues
have also demonstrated changes in the mode of
tumour cell invasion in response to blockade of either
protease or integrin beta 1 function (Hegerfeldt et al.,
2002; Wolf et al., 2003)."

"These studies strongly suggest that some melanoma cells can switch their mode of invasion in response to different environmental challenges.
The molecular basis of this plasticity is not well
understood, microarray analyses have demonstrated that
metastatic melanoma cells express genes associated
with a diverse range of cell lineages and this may in part
explain the diverse modes of motility that melanoma
cells can exhibit in vitro (Hendrix et al., 2001)."

" Analysis of clinical samples suggest that melanoma can invade
both collectively and as single cells; however, our understanding
of switching between modes of invasion and
the cytoskeletal regulators critical for the different
modes of invasion is still very limited."



Some Melanoma Cells can Adapt to their Environment. This has major implications based on Dr. Sahai findings.

This may be why Melanoma is so hard to treat.


Jimmy B