( ( Tumor Cell ) ( ( Invasion ( ( In ( ( the process ) ( of ( ( tissue invasion ) ( by ( an ( epithelial cancer ) ) ) ) ) ) ) ( , ( ( tumor cells ) ( must ( traverse ( ( the barriers ) ( of ( ( ( the ( basement membrane ) ) and ) ( the ( stromal ( extracellular matrix ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Tumor) (NNP Cell)) (VP (VBD Invasion) (SBAR (S (PP (IN In) (NP (NP (DT the) (NN process)) (PP (IN of) (NP (NP (NN tissue) (NN invasion)) (PP (IN by) (NP (DT an) (JJ epithelial) (NN cancer))))))) (, ,) (NP (NN tumor) (NNS cells)) (VP (MD must) (VP (VB traverse) (NP (NP (DT the) (NNS barriers)) (PP (IN of) (NP (NP (DT the) (NN basement) (NN membrane)) (CC and) (NP (DT the) (JJ stromal) (NN extracellular) (NN matrix)))))))))) (. .)))
Tumor Cell Invasion In the process of tissue invasion by an epithelial cancer, tumor cells must traverse the barriers of the basement membrane and the stromal extracellular matrix.
(ROOT (S (NP (NP (DT A) (NN cell) (POS 's)) (NN membrane)) (VP (VBZ provides) (NP (DT a) (NN barrier) (S (VP (TO to) (VP (VB keep) (NP (NN extracellular) (NNS materials)) (PP (IN from) (S (VP (VBG mixing) (PP (IN with) (NP (PRP$ its) (JJ internal) (NNS components))))))))))) (. .)))