Multiple myeloma (MM) is one of the most common hematological neoplasms, constituting about 1% of all human cancers and 2% of all cancer deaths. MM is preceded by monoclonal gammopathy of undetermined significance (MGUS), one of the most common pre-cancerous conditions afflicting 3% of the United States population over 50 years old. Although MM is regarded as an environmental disease, it is not yet clear what promotes the progression from MGUS to the deadly MM. One of the unique features of MM is the extremely low mutation rate of the tumor suppressor p53 gene. Genomic instability (chromosome translocation, aneuploidy, and gene mutation) is widely observed in MM cases, suggesting that the function of p53 as the guardian of the human genome is compromised. We previously analyzed the molecular mechanisms of p53 inactivation in MM cells by a new class of noncoding small RNAs, microRNAs (miRNAs). Data from our laboratory and others have shown that multiple miRNAs suppress expression of the human p53 gene and that a majority of these miRNAs are overexpressed in MM. We hypothesize that the ubiquitous environmental pollutants benzo[a]pyrene (BaP) and tetrachlorodibenzodioxin (TCDD) disrupt functional interactions of miRNA:p53 to mediate p53 inactivation over the course of MM. In this renewal application, we propose 3 specific aims to advance our investigations into the molecular etiology of MM and identify potential treatment and preventive strategies.
In Aim 1, we will dissect the underlying mechanisms of upregulation of miRNAs in MM cells exposed to BaP and TCDD.
In Aim 2, we will determine, using murine syngeneic xenograft and genetic models, whether BaP directly promotes MM progression via one miRNA gene cluster that targets p53.
In Aim 3, we will determine whether epigallocatechin gallate (EGCG, the main component in the botanical drug Polyphenon(R) E) prevents or inhibits MM progression induced by BaP or TCDD. Completion of the goals in this proposal will reveal the role of environmental hydrocarbons in p53:miRNA interaction and in MM etiology and provide a repurposed drug for MM prevention and therapeutic intervention.
The proposed research will provide a better understanding of the role of environmental toxicants in the interaction of miRNAs and the p53 pathway over the course of MM development. By using EGCG (a natural compound in green tea) to modulate the expression of miRNAs for p53 reactivation, our work will identify an accessible option to treat MM with no p53 mutations. In addition, these studies may result in new strategies of cancer prevention for over a million individuals with MGUS, a pre-malignant condition that precedes virtually all cases of MM.
|Gordon, Michael W; Yan, Fang; Zhong, Xiaoming et al. (2015) Regulation of p53-targeting microRNAs by polycyclic aromatic hydrocarbons: Implications in the etiology of multiple myeloma. Mol Carcinog 54:1060-9|
|Wang, Shi; Medeiros, L Jeffrey; Xu-Monette, Zijun Y et al. (2014) Epstein-Barr virus-positive nodular lymphocyte predominant Hodgkin lymphoma. Ann Diagn Pathol 18:203-9|
|Ok, Chi Young; Chen, Jiayu; Xu-Monette, Zijun Y et al. (2014) Clinical implications of phosphorylated STAT3 expression in De Novo diffuse large B-cell lymphoma. Clin Cancer Res 20:5113-23|
|Deng, Qipan; Becker, Lindsey; Ma, Xiaodong et al. (2014) The dichotomy of p53 regulation by noncoding RNAs. J Mol Cell Biol 6:198-205|
|Ok, Chi Young; Li, Ling; Xu-Monette, Zijun Y et al. (2014) Prevalence and clinical implications of epstein-barr virus infection in de novo diffuse large B-cell lymphoma in Western countries. Clin Cancer Res 20:2338-49|
|Ok, Chi Young; Xu-Monette, Zijun Y; Tzankov, Alexandar et al. (2014) Prevalence and clinical implications of cyclin D1 expression in diffuse large B-cell lymphoma (DLBCL) treated with immunochemotherapy: a report from the International DLBCL Rituximab-CHOP Consortium Program. Cancer 120:1818-29|
|Visco, Carlo; Tzankov, Alexander; Xu-Monette, Zijun Y et al. (2013) Patients with diffuse large B-cell lymphoma of germinal center origin with BCL2 translocations have poor outcome, irrespective of MYC status: a report from an International DLBCL rituximab-CHOP Consortium Program Study. Haematologica 98:255-63|
|Hu, Shimin; Xu-Monette, Zijun Y; Balasubramanyam, Aarthi et al. (2013) CD30 expression defines a novel subgroup of diffuse large B-cell lymphoma with favorable prognosis and distinct gene expression signature: a report from the International DLBCL Rituximab-CHOP Consortium Program Study. Blood 121:2715-24|
|Hoeller, Sylvia; Zhou, Yi; Kanagal-Shamanna, Rashmi et al. (2013) Composite mantle cell lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma: a clinicopathologic and molecular study. Hum Pathol 44:110-21|
|Hu, Shimin; Xu-Monette, Zijun Y; Tzankov, Alexander et al. (2013) MYC/BCL2 protein coexpression contributes to the inferior survival of activated B-cell subtype of diffuse large B-cell lymphoma and demonstrates high-risk gene expression signatures: a report from The International DLBCL Rituximab-CHOP Consortium Program. Blood 121:4021-31; quiz 4250|
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