0000000000396966
AUTHOR
Timothy L. Fitzgerald
Roles of NGAL and MMP-9 in the tumor microenvironment and sensitivity to targeted therapy.
Various, diverse molecules contribute to the tumor microenvironment and influence invasion and metastasis. In this review, the roles of neutrophil gelatinase-associated lipocalin (NGAL) and matrix metalloproteinase-9 (MMP-9) in the tumor microenvironment and sensitivity to therapy will be discussed. The lipocalin family of proteins has many important functions. For example when NGAL forms a complex with MMP-9 it increases its stability which is important in cancer metastasis. Small hydrophobic molecules are bound by NGAL which can alter their entry into and efflux from cells. Iron transport and storage are also influenced by NGAL activity. Regulation of iron levels is important for survival…
Roles of GSK-3 and microRNAs on epithelial mesenchymal transition and cancer stem cells.
// James A. McCubrey 1 , Timothy L. Fitzgerald 2 , Li V. Yang 3 , Kvin Lertpiriyapong 4 , Linda S. Steelman 1 , Stephen L. Abrams 1 , Giuseppe Montalto 5,6 , Melchiorre Cervello 6 , Luca M. Neri 7 , Lucio Cocco 8 , Alberto M. Martelli 8 , Piotr Laidler 9 , Joanna Dulinska-Litewka 9 , Dariusz Rakus 10 , Agnieszka Gizak 10 , Ferdinando Nicoletti 11 , Luca Falzone 11 , Saverio Candido 11 and Massimo Libra 11 1 Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, USA 2 Department of Surgery, Brody School of Medicine at East Carolina University, Greenville, NC, USA 3 Department of Internal Medicine, Hematology/Oncology Section, Brody Sc…
Roles of EGFR and KRAS and their downstream signaling pathways in pancreatic cancer and pancreatic cancer stem cells
Pancreatic cancer is currently the fourth most common cancer, is increasing in incidence and soon will be the second leading cause of cancer death in the USA. This is a deadly malignancy with an incidence that approximates the mortality with 44,000 new cases and 36,000 deaths each year. Surgery, although only modestly successful, is the only curative option. However, due the locally aggressive nature and early metastasis, surgery can be performed on less than 20% of patients. Cytotoxic chemotherapy is palliative, has significant toxicity and improves survival very little. Thus new treatment paradigms are needed desperately. Due to the extremely high frequency of KRAS gene mutations (>90%) d…
Effects of mutations in Wnt/β-catenin, hedgehog, Notch and PI3K pathways on GSK-3 activity—Diverse effects on cell growth, metabolism and cancer
Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase that participates in an array of critical cellular processes. GSK-3 was first characterized as an enzyme that phosphorylated and inactivated glycogen synthase. However, subsequent studies have revealed that this moon-lighting protein is involved in numerous signaling pathways that regulate not only metabolism but also have roles in: apoptosis, cell cycle progression, cell renewal, differentiation, embryogenesis, migration, regulation of gene transcription, stem cell biology and survival. In this review, we will discuss the roles that GSK-3 plays in various diseases as well as how this pivotal kinase interacts with multiple sign…
Roles of signaling pathways in drug resistance, cancer initiating cells and cancer progression and metastasis
The EGFR/PI3K/PTEN/Akt/mTORC pathway plays prominent roles in malignant transformation, prevention of apoptosis, drug resistance, cancer initiating cells (CICs) and metastasis. The expression of this pathway is frequently altered in breast and other cancers due to mutations at or aberrant expression of: HER2, EGFR1, PIK3CA, and PTEN as well as other oncogenes and tumor suppressor genes. miRs and epigenetic mechanisms of gene regulation are also important events which regulate this pathway. In some breast cancer cases, mutations at certain components of this pathway (e.g., PIK3CA) are associated with a better prognosis than breast cancers lacking these mutations. The expression of this pathw…
Roles of TP53 in determining therapeutic sensitivity, growth, cellular senescence, invasion and metastasis.
TP53 is a critical tumor suppressor gene that regulates cell cycle progression, apoptosis, cellular senescence and many other properties critical for control of normal cellular growth and death. Due to the pleiotropic effects that TP53 has on gene expression and cellular physiology, mutations at this tumor suppressor gene result in diverse physiological effects. T53 mutations are frequently detected in numerous cancers. The expression of TP53 can be induced by various agents used to treat cancer patients such as chemotherapeutic drugs and ionizing radiation. Radiation will induce Ataxia telangiectasia mutated (ATM) and other kinases that results in the phosphorylation and activation of TP53…
Critical Roles of EGFR family members in breast cancer and breast cancer stem cells: Targets for therapy
The roles of the epidermal growth factor receptor (EGFR) signaling pathway in various cancers including breast, bladder, brain, colorectal, esophageal, gastric, head and neck, hepatocellular, lung, neuroblastoma, ovarian, pancreatic, prostate, renal and other cancers have been keenly investigated since the 1980's. While the receptors and many downstream signaling molecules have been identified and characterized, there is still much to learn about this pathway and how its deregulation can lead to cancer and how it may be differentially regulated in various cell types. Multiple inhibitors to EGFR family members have been developed and many are in clinical use. Current research often focuses o…