Morgan Lab Research Initiatives | NYU Langone Health

Morgan Lab Research Morgan Lab Research Initiatives

Morgan Lab Research Initiatives

Morgan Lab researchers lead a number of research initiatives.

The Molecular Basis of Progression Multiple Myeloma

We have shown that myeloma is not a single disease but is rather composed of at least six distinct subsets with different biological features, each of which could be targeted therapeutically.

We have studied whole exome sequence data from monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and newly-diagnosed multiple myeloma (NDMM) together with light chain amyloidosis and have defined the landscape of mutations, chromosomal translocations, structural events, and copy number abnormalities.

We have identified a distinct set of drivers within each of the disease subsets and identified the central importance of mutational activation of the RAS and NFkB pathways (see Figure 1).

A Spectrum of the Most Common Genetic Variants Associated with Multiple Myeloma
Figure 1: A spectrum of the most common genetic variants associated with multiple myeloma comprises a small set of recurrent mutations and a long tail of rare variants. NRAS, CCND1, MYC, KRAS, followed by DIS3, MMSET, BRAF and FAM46C are relatively more frequent than the other mutated genes.

Our studies have highlighted mutations that can be used clinically to define the prognostic outcome for individual patients or that can be targeted therapeutically.

We have described the landscape of complex rearrangements in the noncoding regions of the multiple myeloma genome including the complex events that include chromothripsis, chromoplexy, and templated insertions.

We are studying the impact of complex structural variants on the epigenetic control of gene regulation and how it could be targeted in multiple myeloma (see Figure 2).

Four Representations of the Impact of Complex Structural Variants on the Epigenetic Control of Gene Regulation and how it Could be Targeted in Multiple Myeloma
Figure 2: New chromosomal structure formation in multiple myeloma. (A) FISH and SKY staining of a metaphase cytogenetic spread formed as a result of a complex structural rearrangement. (B) CIRCOS plot of a complex chained rearrangement. (C) CIRCOS plot showing chromothripsis. (D) Copy number plot of the fusion region of a complex structural event showing copy number oscillation.

Other important genomic changes associated with progression include apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like (APOBEC) mutational signatures, bi-allelic inactivation of tumor suppressor genes together with increased genetic complexity.

Complex events may also be important in progression because they can deregulate more than one gene simultaneously, delivering strong oncogenic signals that may mediate poor clinical outcomes (see Figure 3). We are dissecting out the role played by these structural events in the early phases of disease and their subsequent role at progression.

CIRCOS Plots Demonstrating that Complex Events can Deregulate More than One Gene Simultaneously, Delivering Strong Oncogenic Signals that May Mediate Poor Clinical Outcomes
Figure 3: CIRCOS plots of (A) the spectrum of Ig gene rearrangements in multiple myeloma, and (B) structural rearrangements to MYC driving its overexpression. (C) A set of novel genes upregulated by rearrangement to super-enhancers in multiple myeloma. (D) Boxplots showing the level of expression of genes with and without rearrangement to a super enhancer.

The data we have produced has significantly contributed to the clinical understanding of the biology of progression of myeloma in distinguishing MGUS, smoldering multiple myeloma, and multiple myeloma, in improving prognostic assignment, and finding new factors associated with the risk of developing the disease.

The Molecular Basis and Stage of Origin of Waldenstrom’s Macroglobulinemia

We are applying a similar range of techniques to the analysis of Waldenstrom’s macroglobulinemia as we are using to analyze multiple myeloma. We seek to define the molecular landscape of Waldenstrom’s macroglobulinemia as well as the mutational signatures and evolutionary trajectories leading to disease progression and clinical disease.

The Etiology of Multiple Myeloma and its Excess Risk in African Americans

Genetic predisposition can account for approximatively 10 percent of multiple myeloma cases and with our collaborators we have been able to identify many of the inherited genetic factors contributing to the risk of developing myeloma.

Other factors also contribute including inflammation, aging, obesity, and African American ethnicity, which contributes a three-fold excess risk. Understanding the genetic and environmental contributions to the excess risk will give new insights into the oncogenic pathways leading to multiple myeloma.

To address the risk of developing multiple myeloma by racial origin we are carrying out a whole genome sequencing project of many thousands of cases of myeloma, in patients of different ancestries, to compare the evolutionary trajectories of the early disease phases and whether they differ by racial subgroups.

These comparisons use molecular and immunologic signatures, or “mutagraphs,” that can define both the time of disease origin and the evolutionary trajectories leading to disease progression.

Taking this approach will give insights into the role played by chronic inflammation in both disease initiation and progression.

The concepts of ancestry and ethnicity are different, and we wish to dissect out the contribution of each to the risk of developing multiple myeloma. We will address this question by using a genetic admixture tool to accurately assign racial origin.

To gain further insights, we will integrate environmental information collected as part of a clinical trial of smoldering myeloma. This study is focused on patients of African American origin and will integrate clinical, environmental, and socio-economic information. The study will use sequential analysis, epidemiologic data, and immune and microbiome analyses.

The Molecular Basis of Clinically Aggressive High-Risk Behavior

We have a particular interest in drivers of aggressive clinical behavior caused by genetic events such as the t(4;14) and amplification of the long arm of chromosome 1. We are addressing how the deregulation of the expression and function of key epigenetic modifiers and transcription factors affects disease progression and contributes to high-risk disease.

NSD2

The t(4;14) has been characterized at a molecular level and directly leads to the upregulation of the histone methyl-transferase NSD2. We have set up a number of model systems, including CRISPR knockout and the dTAG systems, to address the role played by NSD2 on the chromatin landscape using multiomic technologies. This information that will allow us to understand its role in t(4;14) myeloma and potentially expand our capacity to target it (see Figure 4).

Data Showing the t(4;14) and NSD2 as a Therapeutic Target in in Multiple Myeloma
Figure 4: Chromosomal translocations are an important etiological mechanism in multiple myeloma with the t(4;14) being seen in 10 to 15 percent of cases. The t(4;14) defines a key adverse prognostic subgroup in multiple myeloma. As a result of the translocation, the t(4;14) upregulates FGFr3 and NSD2 with NSD2 being the critical driver variant that determines the biology and outcome of clones carrying the variant. We have shown that NSD2 is the critical driver variant and is seen in 100 percent of the clonal cells. A distinct range of mutations are superimposed on the genetic background defined by NSD2 that contribute to disease progression. Therefore, it is potentially a key therapeutic target. We have shown that knocking down NSD2 inhibits cellular proliferation. To address the mechanism of how NSD2 transforms cells and impacts epigenetics and signaling, we have set up the dTAG system in a cell line system in which the impact of knockdown can be determined in real time.

PHF19

We have shown that one of the prognostic features for aggressive clinical disease is the overexpression of PHF19, an epigenetically-active Tudor Domain containing protein. PHF19 is part of the PRC2 complex which may have a key role in aggressive disease and we are investigating this role further in model systems.

Gain of Chromosome 1

One of the key players in aggressive disease is the gain and amplification of chromosome 1. In order to define the drivers on chromosome 1 we have studied chromosome 1 at a structural level and will take a genomics approach to study important regulons located along the long arm and their impact on chromatin.

The Tumor Microenvironment and Aggressive Myeloma

We are addressing the interaction between genomic factors, the microenvironment, and response to treatment. Using simultaneous single-cell epitope and transcriptome measurement of both the tumor cells and the microenvironment, we have identified a “high-risk microenvironment”. This environment is characterized by an excess of classical monocytes that differ between responders and non-responders. Our future analyses will focus on cellular and chromatin states to better understand the effect of the malignant plasma cells on the monocyte compartment in vitro.

Targeted Therapeutics for Multiple Myeloma

We are collaborating with other investigators at NYU Langone to investigate novel targeted therapeutic strategies for multiple myeloma. In particular, we are looking at the role of targeted nanobody conjugates and targeting the endoplasmic reticulum as a means of therapeutically addressing RAS mutated myeloma.