Monday, December 1, 2025 12/1/2025

Manipulating the N-end Rule Protein Degradation Pathway to Build Bone and Decrease Tumor Growth in Multiple Myeloma Bone Disease

Award Number: R01CA241677
ORGANIZATION: NATIONAL CANCER INSTITUTE
OPDIV: NIH
AWARD CLASS: DISCRETIONARY
AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)
PERIOD OF PERFORMANCE START DATE: 03/04/2020
PERIOD OF PERFORMANCE END DATE: 06/30/2025

Group Awards By:

View Award Description

Manipulating the N-end Rule Protein Degradation Pathway to Build Bone and Decrease Tumor Growth in Multiple Myeloma Bone Disease - Project Summary/Abstract Multiple Myeloma (MM) causes devastating bone destruction and protracted suppression of bone formation that markedly increases fracture risk, impacts mortality and contributes to MM cell drug resistance. MM bone lesions rarely heal in most patients, so that severe bone pain and fracture risk persist. Currently, there are no safe bone anabolic agents approved for MM bone disease (MMBD). We showed that the multi-domain protein p62 (sequestosome-1) is a major contributor to MMBD through its two major functions. It is a signaling hub for multiple signaling pathways that increase MM cell growth, bone destruction OB suppression in MM. p62 also mediates pro-survival functions in MM cells as a cargo receptor for ubiquitin-mediated autophagy. The p62-ZZ domain (p62-ZZ), plays a key role in both these functions, and is the focus of this proposal. We, with colleagues at University of Pittsburgh, developed XRK3F2 (XRK), a small molecule that binds p62-ZZ. We found that XRK induced dramatic new bone formation in MM-bearing mice, allowed MM patient-derived bone marrow stromal cells (MM-BMSC) to differentiate to functional OB, induced MM cell death and enhanced the anti-MM effects of Bortezomib (Btz) and Carfilzomib, proteasome inhibitors (PIs) used for MM treatment. However, the mechanisms responsible for XRK’s effects in MM are unclear. Recently, our collaborators found that p62-ZZ is a high-affinity N-recognin for N-terminal argininylated proteins generated by the N-end rule pathway, and that XRK acts as a high affinity degron for p62- ZZ, mimicking endogenous N-end degrons. The N-end rule pathway (N-ERP) is a proteolytic system that protects cells from the proteotoxic stress of misfolded proteins (MPs) in the cytosol that normally are targeted for ER-associated degradation, and shuttles them to proteasome and autophagy-mediated degradation pathways. Excess MPs trigger release of chaperones from the ER that are then N-arginylated and bind MPs. The N-R protein complexes bind either the UBR box of N-recognins for subsequent proteosomal degradation, or p62-ZZ for autophagic proteolysis. We recently found that saturating p62-ZZ with XRK increased PI-induced MM cell death via necroptosis, even in PI-resistant cells. Thus, p62-ZZ serves as the molecular switch for necroptotic vs. apoptotic cell death pathways in MM cells. However, how XRK’s actions as a high-affinity N-degron that binds p62-ZZ are uncharacterized in MM or BMSCs. We will use in vitro and in vivo approaches to determine; Aim 1: The mechanisms responsible for XRK’s relief of the suppressed OB differentiation in BMSC exposed to MM cells or TNF, and the contributions of inflammatory cytokines to this process. Aim 2: The mechanisms responsible and relative contributions of XRK’s effects on osteocytes in MMBD. Aim 3: The importance of necroptosis-mediated cell death in MM, and its regulation by the p62-ZZ/N- ERP and proteasome pathways. Aim 4: The in vivo effects of combining XRK targeting of p62-ZZ +/- PI treatment on MMBD and healing MM bone lesions. These studies should provide important new information on the p62- ZZ/N-ERP pathway as a therapeutic target to build bone and decrease tumor growth in MMBD.


Issue Date FY	Funding FY	Legal Entity Name	Legal Entity Address	Legal Entity City	Legal Entity State	Legal Entity Zip Code	Legal Entity COUNTY	Legal Entity COUNTRY	Assistance Listing	Award Code	Budget Year	Action Date	Action Type	Action Amount

Issue Date FY: 2026 ( Subtotal = -$16,582 )
2026	2024	TRUSTEES OF INDIANA UNIVERSITY	980 INDIANA AVE RM 2232	INDIANAPOLIS	IN	46202	MARION	USA	Cancer Biology Research	000	5	11/26/2025	NON-COMPETING CONTINUATION	-$16,582
														Subtotal = -$16,582

Issue Date FY: 2024 ( Subtotal = $315,848 )
2024	2024	TRUSTEES OF INDIANA UNIVERSITY	980 INDIANA AVE RM 2232	INDIANAPOLIS	IN	46202	MARION	USA	Cancer Biology Research	001	5	4/18/2024	NON-COMPETING CONTINUATION	$16,624
2024	2024	TRUSTEES OF INDIANA UNIVERSITY	980 INDIANA AVE RM 2232	INDIANAPOLIS	IN	46202	MARION	USA	Cancer Biology Research	000	5	2/9/2024	NON-COMPETING CONTINUATION	$299,224
														Subtotal = $315,848

Issue Date FY: 2023 ( Subtotal = $325,822 )
2023	2023	TRUSTEES OF INDIANA UNIVERSITY	980 INDIANA AVE RM 2232	INDIANAPOLIS	IN	46202	MARION	USA	Cancer Biology Research	000	4	3/20/2023	NON-COMPETING CONTINUATION	$325,822
2023	2023	TRUSTEES OF INDIANA UNIVERSITY	980 INDIANA AVE RM 2232	INDIANAPOLIS	IN	46202	MARION	USA	Cancer Biology Research	001	4	6/2/2023	NON-COMPETING CONTINUATION	$0
														Subtotal = $325,822

Issue Date FY: 2022 ( Subtotal = $325,822 )
2022	2022	TRUSTEES OF INDIANA UNIVERSITY	980 INDIANA AVE RM 2232	INDIANAPOLIS	IN	46202	MARION	USA	Cancer Biology Research	001	3	5/11/2022	NON-COMPETING CONTINUATION	$26,601
2022	2022	TRUSTEES OF INDIANA UNIVERSITY	980 INDIANA AVE RM 2232	INDIANAPOLIS	IN	46202	MARION	USA	Cancer Biology Research	000	3	3/1/2022	NON-COMPETING CONTINUATION	$299,221
														Subtotal = $325,822

Issue Date FY: 2021 ( Subtotal = $332,471 )
2021	2021	TRUSTEES OF INDIANA UNIVERSITY	980 INDIANA AVE RM 2232	INDIANAPOLIS	IN	46202	MARION	USA	Cancer Biology Research	000	2	2/17/2021	NON-COMPETING CONTINUATION	$332,471
														Subtotal = $332,471

Issue Date FY: 2020 ( Subtotal = $332,471 )
2020	2020	TRUSTEES OF INDIANA UNIVERSITY	980 INDIANA AVE RM 2232	INDIANAPOLIS	IN	46202	MARION	USA	Cancer Biology Research	000	1	3/4/2020	NEW	$332,471
														Subtotal = $332,471

Grand Total All Awards = $1,615,852

Top

All Categories

About

Search

Reports

Data Submission

Award Information

Manipulating the N-end Rule Protein Degradation Pathway to Build Bone and Decrease Tumor Growth in Multiple Myeloma Bone Disease

Award Number: R01CA241677

ORGANIZATION: NATIONAL CANCER INSTITUTE

OPDIV: NIH

AWARD CLASS: DISCRETIONARY

AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)

PERIOD OF PERFORMANCE START DATE: 03/04/2020

PERIOD OF PERFORMANCE END DATE: 06/30/2025

Federal Websites

Department of Health & Human Services

HHS Operating Divisions

HHS Staff Divisions

Download A Document Viewer