A global survey of
cancer has shown that
lung cancer is the most common cause of the new
cancer cases and
cancer deaths in men worldwide. The mortality from
lung cancer is more than the combined mortality from breast, prostate and
colorectal cancers. The two major histological types of
lung cancer are
non-small cell lung cancer (NSCLC) accounting for about 85 % of cases and
small cell lung cancer accounting for 15 % of cases. NSCLC, the more prevalent form of
lung cancer, is often diagnosed at an advanced stage and has a very poor prognosis. Many factors have been shown to contribute to the development of
lung cancer in humans including tobacco smoking, exposure to
environmental carcinogens (
asbestos, or
radon) and genetic factors. Despite the advances in treatment,
lung cancer remains one of the leading causes of
cancer death worldwide. Interestingly, the overall 5 year survival from
lung cancer has not changed appreciably in the past 25 years. For this reason, novel and more effective treatments and strategies for NSCLC are critically needed.
p90 ribosomal S6 kinase (RSK), a
serine threonine kinase that lies downstream of the Ras-MAPK (
mitogen activated protein kinase) cascade, has been demonstrated to be involved in the regulation of cell proliferation in various
malignancies through indirect (e.g., modulation of
transcription factors) or direct effects on the cell-cycle machinery. Increased expression of RSK has been demonstrated in various
cancers, including
lung cancer. This review focuses on the role of RSK in
lung cancer and its potential therapeutic application.