( ( For ( ( a ( cancer cell ) ) ( to metastasize ) ) ) ( there ( ( must ( be ( ( ( a cascade ) ( of ( complex ( enzymatic events ) ) ) ) ( that ( ( break down ) ( cell-extracellular ( matrix ( protein interactions ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (PP (IN For) (NP (NP (DT a) (NN cancer) (NN cell)) (PP (TO to) (NP (NN metastasize))))) (NP (EX there)) (VP (MD must) (VP (VB be) (NP (NP (DT a) (NN cascade)) (PP (IN of) (NP (JJ complex) (JJ enzymatic) (NNS events))) (SBAR (WHNP (WDT that)) (S (VP (VBP break) (PRT (RP down)) (NP (JJ cell-extracellular) (NN matrix) (NN protein) (NNS interactions)))))))) (. .)))
For a cancer cell to metastasize there must be a cascade of complex enzymatic events that break down cell-extracellular matrix protein interactions.
(ROOT (S (NP (JJ Enzymatic) (NNS cascades)) (VP (VBP help) (VP (VB amplify) (NP (NP (DT the) (NNS effects)) (PP (IN of) (NP (NN extracellular) (NNS signals)))))) (. .)))