Unc-51 Like Kinase 3 (ULK3) is essential for autophagy and cell survival in multiple myeloma

Area of Science:

• Oncology
• Molecular Biology
• Cellular Biology

Background:

• Multiple myeloma (MM) often relapses with refractory disease despite current therapies like proteasome inhibitors.
• Identifying novel therapeutic targets is crucial for improving patient outcomes in MM.

Purpose of the Study:

• To investigate the role of autophagy genes in multiple myeloma progression.
• To evaluate ULK3 as a potential therapeutic target for MM treatment.

Main Methods:

• RNA sequencing analysis of 813 CD138+ MM patient samples.
• Functional studies of ULK3 in MM cell survival.
• Generation and testing of ULK3 inhibitors (SG3-014/MA9-060).
• In vivo studies in mouse models and ex vivo validation in patient samples.

Main Results:

• A strong association between an autophagy gene signature, particularly ULK3 expression, and MM disease progression was identified.
• ULK3 inhibition reduced MM tumor burden, improved survival, and protected against bone disease in vivo.
• The ULK3 inhibitor MA9-060 restored sensitivity to proteasome inhibitors in resistant MM cells, with synergy validated in patient samples.

Conclusions:

• ULK3 plays a significant role in MM cell survival and disease progression through autophagy.
• ULK3 inhibition represents a promising therapeutic strategy for both newly diagnosed and refractory multiple myeloma.
• Combined ULK3 inhibition and proteasome inhibitor therapy shows potential for overcoming drug resistance in MM.