title: Cooperative interactions of PTEN deficiency and RAS activation in melanoma metastasis.
abstract: Mitogen-activated protein kinase (MAPK) and AKT pathways are frequently co-activated in melanoma through overexpression of receptor tyrosine kinases, mutations in their signaling surrogates, such as RAS and BRAF, or loss of negative regulators such as PTEN. As RAS can be a positive upstream regulator of PI3-K, it has been proposed that the loss of PTEN and the activation of RAS are redundant events in melanoma pathogenesis. Here, in genetically engineered mouse models of cutaneous melanomas, we sought to better understand the genetic interactions between HRAS activation and PTEN inactivation in melanoma genesis and progression in vivo. We showed that HRAS activation cooperates with Pten+/- and Ink4a/Arf-/- to increase melanoma penetrance and promote metastasis. Correspondingly, gain- and loss-of-function studies established that Pten loss increases invasion and migration of melanoma cells and non-transformed melanocytes, and such biological activity correlates with a shift to phosphorylation of AKT2 isoform and E-cadherin down-regulation. Thus, Pten inactivation can drive the genesis and promote the metastatic progression of RAS activated Ink4a/Arf deficient melanomas.
authors: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
authors: C
authors: C
authors: Nogueira
authors: K-H
authors: KH
authors: Kim
authors: H
authors: H
authors: Sung
authors: K H T
authors: KH
authors: Paraiso
authors: J-H
authors: JH
authors: Dannenberg
authors: M
authors: M
authors: Bosenberg
authors: L
authors: L
authors: Chin
authors: M
authors: M
authors: Kim
mesh_terms: D000818:Animals; D015820:Cadherins / Q000235:genetics; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D015536:Down-Regulation / Q000235:genetics; D004789:Enzyme Activation / Q000235:genetics; D055785:Gene Knockdown Techniques; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D008544:Melanocytes / Q000378:metabolism / Q000473:pathology; D008545:Melanoma / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D051379:Mice; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D051059:PTEN Phosphohydrolase / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*
chemical_list: D015820:Cadherins; D007527:Isoenzymes; D051057:Proto-Oncogene Proteins c-akt; D051059:PTEN Phosphohydrolase; D016283:Proto-Oncogene Proteins p21(ras)