The incidence of Non-Hodgkin's lymphoma (NHL) in the USA has dramatically increased over the past two decades. Diffuse large B-cell lymphoma (DLBCL) is the most frequently diagnosed lymphoma in the REAL international study accounting for approximately a third of all cases. Unfortunately, despite aggressive chemotherapy for DLBCL the still high fatality rate illustrates the urgent need for innovative approaches. Most advances in NHL in recent years have come from development of disease-specific molecular targeted agents. Chronic alcohol consumption is associated with an increased risk for cancers of various organs. Interestingly, in contrast to solid tumors, there has been epidemiologic evidence indicating that alcohol decreases the risk for most types of non-Hodgkin's lymphoma. The mechanisms accounting for such paradoxical and alcohol-induced decrease in the incidence of NHL remain largely unknown. Previous work from others has shown that ethanol decreases protein synthesis in cells, although the underlying regulatory mechanisms of this process are not fully understood. There is recent evidence suggesting that chronic alcohol intake is associated with suppression of the mTOR/p70 S6K signaling pathway, a pathway that plays key roles in the control of important cellular processes, including cell survival and growth. It is therefore possible that alcohol-dependent inhibition of mTOR and its effectors in human lymphocytes is associated with decreased incidence of lymphomagenesis. The central hypothesis of this proposal is that alcohol directly inhibits mTOR and/or its effectors, resulting in suppression of cap-dependent mRNA translation and protein synthesis in human lymphocytes;and that such a mechanism accounts for the anti-lymphoma properties of alcohol. Understanding the underlying molecular and biochemical mechanisms by which chronic alcohol consumption suppresses lymphoma development may be important for developing novel strategies for the prevention and treatment of lymphoma. Towards this end we will pursue several lines of investigation: 1) Does alcohol suppress mTOR activity in human lymphocytes directly or indirectly? What are the effects of mTOR on upstream mTOR regulators such as the PI 3'kinase and the akt kinase? 2) Does alcohol inhibit p70 S6K activity and its downstream effectors S6 ribosomal protein and eukaryotic initiation factor 4B? 3) What are the effects of alcohol on the phosphorylation of the translational repressor 4E-BP1 and the formation of 4E-BP1-eIF4E complexes? What are the effects of alcohol on cap-dependent translation in normal human lymphocytes and malignant lymphoma cells? The specific aims are:
Specific Aim 1 : To determine whether alcohol exhibits suppressive effects on the activation of the mTOR pathway in lymphocytes and malignant lymphoma cells and to identify the mechanisms by which it exhibits such effects.
Specific Aim 2 : To examine the effects of alcohol on the activation and function of downstream effectors of the mTOR pathway, including S6 ribosomal protein, eIF4B and 4E-BP1.
Specific Aim 3 : To examine the ability of chronic ethanol exposure on lymphoma xenografts as well as its capacity to attenuate the development of lymphomas in a p53 mouse model. Altogether, these studies should help us understand the mechanisms by which alcohol inhibits malignant lymphomas and may form the basis for the development of innovative approaches to block lymphoma growth, including the future design of more selective and specific pharmacological agents that target similar pathways.

Public Health Relevance

The incidence of Non-Hodgkin's lymphoma (NHL) in the USA has dramatically increased over the past two decades. Unfortunately, despite aggressive chemotherapy mortality is greater than 50% and is associated with significant toxicity especially in the elderly. The still high fatality rate illustrates the limitations of the existing therapies and the urgent need for innovative approaches. Most advances in NHL in recent years have come from development of disease-specific molecular targeted agents. A number of epidemiologic studies to date support the increasingly accepted view that current alcohol consumers have decreased risk of most types of non-Hodgkin's lymphoma. The underlying biological mechanism(s) for this negative association is unknown at present. EtOH decreases protein synthesis, and this effect is associated with changes in the phosphorylation status of several key components of the translational machinery. Chronic alcohol intake is associated with disruption of the mTOR-signaling pathway and recent finding with major relevance to this proposal, is that activation of the mTOR signaling pathway has recently been demonstrated in NHL providing strong rationale for the development of mTOR targeted therapy in lymphoid malignancies. Therefore, improved understanding of the underlying molecular mechanism(s) associated with the ability of EtOH to suppress mTOR activity may form the basis for the development of innovative approaches to block lymphoma growth.

Agency
National Institute of Health (NIH)
Institute
National Institute on Alcohol Abuse and Alcoholism (NIAAA)
Type
Research Project (R01)
Project #
5R01AA017972-03
Application #
8127669
Study Section
Tumor Cell Biology Study Section (TCB)
Program Officer
Murray, Gary
Project Start
2009-09-05
Project End
2014-08-31
Budget Start
2011-09-01
Budget End
2012-08-31
Support Year
3
Fiscal Year
2011
Total Cost
$339,003
Indirect Cost
Name
University of Maryland Baltimore
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Dai, B; Chen, A Y; Corkum, C P et al. (2016) Hepatitis C virus upregulates B-cell receptor signaling: a novel mechanism for HCV-associated B-cell lymphoproliferative disorders. Oncogene 35:2979-90
Mazan-Mamczarz, Krystyna; Peroutka, Raymond J; Steinhardt, James J et al. (2015) Distinct inhibitory effects on mTOR signaling by ethanol and INK128 in diffuse large B-cell lymphoma. Cell Commun Signal 13:15
Landon, Ari L; Muniandy, Parameswary A; Shetty, Amol C et al. (2014) MNKs act as a regulatory switch for eIF4E1 and eIF4E3 driven mRNA translation in DLBCL. Nat Commun 5:5413
Mazan-Mamczarz, Krystyna; Zhao, X Frank; Dai, Bojie et al. (2014) Down-regulation of eIF4GII by miR-520c-3p represses diffuse large B cell lymphoma development. PLoS Genet 10:e1004105
Steinhardt, James J; Peroutka, Raymond J; Mazan-Mamczarz, Krystyna et al. (2014) Inhibiting CARD11 translation during BCR activation by targeting the eIF4A RNA helicase. Blood 124:3758-67
Mazan-Mamczarz, Krystyna; Gartenhaus, Ronald B (2013) Role of microRNA deregulation in the pathogenesis of diffuse large B-cell lymphoma (DLBCL). Leuk Res 37:1420-8
Steinhardt, James J; Gartenhaus, Ronald B (2013) Epigenetic approaches for chemosensitization of refractory diffuse large B-cell lymphomas. Cancer Discov 3:968-70
Steinhardt, James J; Gartenhaus, Ronald B (2012) Promising personalized therapeutic options for diffuse large B-cell Lymphoma Subtypes with oncogene addictions. Clin Cancer Res 18:4538-48
Bhalla, Savita; Evens, Andrew M; Dai, Bojie et al. (2011) The novel anti-MEK small molecule AZD6244 induces BIM-dependent and AKT-independent apoptosis in diffuse large B-cell lymphoma. Blood 118:1052-61
Hagner, P R; Mazan-Mamczarz, K; Dai, B et al. (2011) Ribosomal protein S6 is highly expressed in non-Hodgkin lymphoma and associates with mRNA containing a 5' terminal oligopyrimidine tract. Oncogene 30:1531-41

Showing the most recent 10 out of 13 publications