Title:Role of Human and Mouse HspB1 in Metastasis
VOLUME: 12 ISSUE: 9
Author(s):G.M. Nagaraja, P. Kaur and A. Asea
Affiliation:Division of Investigative Pathology, Scott & White Healthcare and the Texas A&M Health Science Center, College of Medicine, Temple, TX 76504, USA.
Keywords:Cancer, CD8+ CTL, heat shock proteins, lentivirus, metastasis, siRNA, tumor, connective tissue, intravasation, lymphatic system, extravasation, ocular melanoma, polymerization, acto-myosin contraction, phenotype
Abstract:Heat shock proteins (HSP) are a group of physiologically-essential, highly-conserved proteins that
are induced by heat shock, as well as by other environmental and pathophysiological stressors. The twentyseven
kDa heat shock protein (Hsp27; HspB1) is highly expressed in tumor tissues of patients diagnosed with
cancer and expression levels correlate with poor prognosis. HspB1 plays a dual role in cancer and promotes
both cancer development by suppressing host anti-cancer response, such as apoptosis and senescence, and
facilitates the enhanced expression of metastastic genes. HspB1-mediated protection from tumor cell
apoptosis induced by chemotherapeutic drugs occurs through several mechanisms, including decreased
production of reactive oxygen species, restoration of protein homeostasis and promotion of cell survival by
protein folding, stabilization of actin-cytoskeleton, delayed release of cytochrome c from mitochondria and
inhibition of activation of caspase-3. High levels of HSP expression affect tumor susceptibility to adjuvant
cancer treatments, including chemotherapy, hyperthermia, and radiation. This review highlights the most
recent findings and role of HspB1 in metastasis.
