Abstract

Cancer is a genetic disease with unclear etiology, whereas its appearance and progression is characterized by special events such as sustaining proliferative signaling, evading growth suppressors, enabling replicative immortality, resisting cell death, inducing and activating invasion and metastasis. The disease arises from mutations in genes, oncogenes and tumor suppressor genes, that are implicated in growth, differentiation, or death. An oncogene is a mutated gene whose its protein is produced in higher quantities or whose altered product has increased activity and therefore acts in a dominant manner. In tumor suppressor genes the mutation has caused a loss of function, and therefore most are recessive in nature because both alleles must be mutated, as a mutation in only one allele is sufficient for an effect. More than 100 oncogenes and at least 15 tumor suppressor genes have been identified. In the current review we focus on the roles of some of the most important oncogenes that have an active contribution in cell signaling pathways and implicated in cell surviving, proliferation and malignancy transformation. Those cell signaling pathways are the target of diverse anti-malignant drugs, such as special inhibitors and monoclonical antibodies in order to inhibit their effects in malignant transformation and development of cancer.