Oncogenic kinase signaling in human neoplasms

Oncogenic proteins participate in cellular functions that involve transduction of signals from the extracellular environment, through the membrane, into the cytoplasm towards the nucleus, where transcription is initiated to generate proteins that will eventually contribute to the oncogenic phenotype. The wild-type homologues of cellular oncoproteins (proto-oncoproteins) frequently participate in signal transduction mechanisms that regulate cell and tissue homeostasis. Deregulation of proto-oncoprotein expression or function results in altered cellular signaling, oncogenic transformation, and inhibition of apoptosis. Oncogenic signals initiated from mutant proteins can override endogenous homeostasis control mechanisms such as anoikis and apoptosis and result in anchorage-independent growth, uncontrolled proliferation, and metastasis.