Advances in Targeting Signal Transduction Pathways
// James A. McCubrey 1 , Linda S. Steelman 1 , William H. Chappell 1 , Lin Sun 1,2 , Nicole M. Davis 1 , Stephen L. Abrams 1 , Richard A. Franklin 1 , Lucio Cocco 3 , Camilla Evangelisti 4 , Francesca Chiarini 4 , Alberto M. Martelli 3,4 , Massimo Libra 5 , Saverio Candido 5 , Giovanni Ligresti 5 , Grazia Malaponte 5 , Maria C. Mazzarino 5 , Paolo Fagone 5 , Marco Donia 5 , Ferdinando Nicoletti 5 , Jerry Polesel 6 , Renato Talamini 6 , Jorg Basecke 7 , Sanja Mijatovic 8 , Danijela Maksimovic-Ivanic 8 , Michele Milella 9 , Agostino Tafuri 10 , Joanna Dulinska-Litewka 11 , Piotr Laidler 11 , Antonio B. D’Assoro 12 , Lyudmyla Drobot 13 , Kazuo Umezawa 14 , Giuseppe Montalto 15 , Melchiorre Cer…
Mutations and Deregulation of Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR Cascades Which Alter Therapy Response.
The Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascades are often activated by genetic alterations in upstream signaling molecules such as receptor tyrosine kinases (RTK). Certain components of these pathways, RAS, NF1, BRAF, MEK1, DUSP5, PP2A, PIK3CA, PIK3R1, PIK3R4, PIK3R5, IRS4, AKT, NFKB1, MTOR, PTEN, TSC1, and TSC2 may also be activated/inactivated by mutations or epigenetic silencing. Upstream mutations in one signaling pathway or even in downstream components of the same pathway can alter the sensitivity of the cells to certain small molecule inhibitors. These pathways have profound effects on proliferative, apoptotic and differentiation pathways. Dysregulation of components of these cas…
Therapeutic resistance resulting from mutations in Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR signaling pathways.
Chemotherapy remains a commonly used therapeutic approach for many cancers. Indeed chemotherapy is relatively effective for treatment of certain cancers and it may be the only therapy (besides radiotherapy) that is appropriate for certain cancers. However, a common problem with chemotherapy is the development of drug resistance. Many studies on the mechanisms of drug resistance concentrated on the expression of membrane transporters and how they could be aberrantly regulated in drug resistant cells. Attempts were made to isolate specific inhibitors which could be used to treat drug resistant patients. Unfortunately most of these drug transporter inhibitors have not proven effective for ther…
Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR inhibitors: Rationale and importance to inhibiting these pathways in human health
William H. Chappell 1 , Linda S. Steelman 1,2 , Jacquelyn M. Long 2 , Ruth C. Kempf 2 , Stephen L. Abrams 1 , Richard A. Franklin 1 , Jorg Basecke 3 , Franca Stivala 4 , Marco Donia 4 , Paolo Fagone 4 , Graziella Malaponte 4 , Maria C. Mazzarino 4 , Ferdinando Nicoletti 4 , Massimo Libra 4 , Danijela Maksimovic-Ivanic 5 , Sanja Mijatovic 5 , Giuseppe Montalto 6 , Melchiorre Cervello 7 , Piotr Laidler 8 , Michele Milella 9 , Agostino Tafuri 10 , Antonio Bonati 11 , Camilla Evangelisti 12 , Lucio Cocco 12 , Alberto M. Martelli 12,13 , and James A. McCubrey 1 1 Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University 2 Department of Physics, Greenville, N…
Roles of the Raf/MEK/ERK and PI3K/PTEN/Akt/mtor pathways in controlling growth and sensitivity to therapy-implications for cancer and aging
Dysregulated signaling through the Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR pathways is often the result of genetic alterations in critical components in these pathways or upstream activators. Unrestricted cellular proliferation and decreased sensitivity to apoptotic-inducing agents are typically associated with activation of these pro-survival pathways. This review discusses the functions these pathways have in normal and neoplastic tissue growth and how they contribute to resistance to apoptotic stimuli. Crosstalk and commonly identified mutations that occur within these pathways that contribute to abnormal activation and cancer growth will also be addressed. Finally the recently described …
Targeting the Cancer Initiating Cell: The Ultimate Target for Cancer Therapy
An area of therapeutic interest in cancer biology and treatment is targeting the cancer stem cell, more appropriately referred to as the cancer initiating cell (CIC). CICs comprise a subset of hierarchically organized, rare cancer cells with the ability to initiate cancer in xenografts in genetically modified murine models. CICs are thought to be responsible for tumor onset, self-renewal/maintenance, mutation accumulation and metastasis. CICs may lay dormant after various cancer therapies which eliminate the more rapidly proliferating bulk cancer (BC) mass. However, CICs may remerge after therapy is discontinued as they may represent cells which were either intrinsically resistant to the or…
Ras/Raf/MEK/ERK and PI3K/PTEN/Akt/mTOR cascade inhibitors: How mutations can result in therapy resistance and how to overcome resistance
// James A. McCubrey 1 , Linda S. Steelman 1 , William H. Chappell 1 , Stephen L. Abrams 1 , Richard A. Franklin 1 , Giuseppe Montalto 2 , Melchiorre Cervello 3 , Massimo Libra 4 , Saverio Candido 4 , Grazia Malaponte 4 , Maria C. Mazzarino 4 , Paolo Fagone 4 , Ferdinando Nicoletti 4 , Jorg Basecke 5 , Sanja Mijatovic 6 , Danijela Maksimovic-Ivanic 6 , Michele Milella 7 , Agostino Tafuri 8 , Francesca Chiarini 9 , Camilla Evangelisti 9 , Lucio Cocco 10 , Alberto M. Martelli 9,10 1 Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, USA 2 Department of Internal Medicine and Specialties, University of Palermo, Palermo, Italy 3 Consi…
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…