Blockade of the LncRNA-DOT1L-LAMP5 Axis Enhances Autophagy and Promotes Degradation of MLL Fusion Proteins

Overview

Journal Exp Hematol Oncol

Publisher Biomed Central

Specialty Hematology

Date 2024 Feb 19

PMID 38374003

Authors

Tian-Qi Chen

Heng-Jing Huang

Shun-Xin Zhu

Xiao-Tong Chen

Ke-Jia Pu

Dan Wang

Yan An

Jun-Yi Lian

Yu-Meng Sun

Yue-Qin Chen

Wen-Tao Wang

Affiliations

Soon will be listed here.

Abstract

Background: Mixed-lineage leukemia (MLL) fusion gene caused by chromosomal rearrangement is a dominant oncogenic driver in leukemia. Due to having diverse MLL rearrangements and complex characteristics, MLL leukemia treated by currently available strategies is frequently associated with a poor outcome. Therefore, there is an urgent need to identify novel therapeutic targets for hematological malignancies with MLL rearrangements.

Methods: qRT-PCR, western blot, and spearman correction analysis were used to validate the regulation of LAMP5-AS1 on LAMP5 expression. In vitro and in vivo experiments were conducted to assess the functional relevance of LAMP5-AS1 in MLL leukemia cell survival. We utilized chromatin isolation by RNA purification (ChIRP) assay, RNA pull-down assay, chromatin immunoprecipitation (ChIP), RNA fluorescence in situ hybridization (FISH), and immunofluorescence to elucidate the relationship among LAMP5-AS1, DOT1L, and the LAMP5 locus. Autophagy regulation by LAMP5-AS1 was evaluated through LC3B puncta, autolysosome observation via transmission electron microscopy (TEM), and mRFP-GFP-LC3 puncta in autophagic flux.

Results: The study shows the crucial role of LAMP5-AS1 in promoting MLL leukemia cell survival. LAMP5-AS1 acts as a novel autophagic suppressor, safeguarding MLL fusion proteins from autophagic degradation. Knocking down LAMP5-AS1 significantly induced apoptosis in MLL leukemia cell lines and primary cells and extended the survival of mice in vivo. Mechanistically, LAMP5-AS1 recruits the H3K79 histone methyltransferase DOT1L to LAMP5 locus, directly activating LAMP5 expression. Importantly, blockade of LAMP5-AS1-LAMP5 axis can represses MLL fusion proteins by enhancing their degradation.

Conclusions: The findings underscore the significance of LAMP5-AS1 in MLL leukemia progression through the regulation of the autophagy pathway. Additionally, this study unveils the novel lncRNA-DOT1L-LAMP5 axis as promising therapeutic targets for degrading MLL fusion proteins.

References

Sathe G, Sapkota G . Proteomic approaches advancing targeted protein degradation. Trends Pharmacol Sci. 2023; 44(11):786-801. DOI: 10.1016/j.tips.2023.08.007. View

Helgason G, Karvela M, Holyoake T . Kill one bird with two stones: potential efficacy of BCR-ABL and autophagy inhibition in CML. Blood. 2011; 118(8):2035-43. DOI: 10.1182/blood-2011-01-330621. View

Li X, Song Y . Structure, function and inhibition of critical protein-protein interactions involving mixed lineage leukemia 1 and its fusion oncoproteins. J Hematol Oncol. 2021; 14(1):56. PMC: 8022399. DOI: 10.1186/s13045-021-01057-7. View

Goodall G, Wickramasinghe V . RNA in cancer. Nat Rev Cancer. 2020; 21(1):22-36. DOI: 10.1038/s41568-020-00306-0. View

Sparavier A, Di Croce L . Polycomb complexes in MLL-AF9-related leukemias. Curr Opin Genet Dev. 2022; 75:101920. DOI: 10.1016/j.gde.2022.101920. View

Meyer C, Larghero P, Almeida Lopes B, Burmeister T, Groger D, Sutton R . The KMT2A recombinome of acute leukemias in 2023. Leukemia. 2023; 37(5):988-1005. PMC: 10169636. DOI: 10.1038/s41375-023-01877-1. View

Klionsky D, Abdel-Aziz A, Abdelfatah S, Abdellatif M, Abdoli A, Abel S . Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition). Autophagy. 2021; 17(1):1-382. PMC: 7996087. DOI: 10.1080/15548627.2020.1797280. View

Issa G, Ravandi F, DiNardo C, Jabbour E, Kantarjian H, Andreeff M . Therapeutic implications of menin inhibition in acute leukemias. Leukemia. 2021; 35(9):2482-2495. DOI: 10.1038/s41375-021-01309-y. View

He M, Cao C, Ni Z, Liu Y, Song P, Hao S . PROTACs: great opportunities for academia and industry (an update from 2020 to 2021). Signal Transduct Target Ther. 2022; 7(1):181. PMC: 9178337. DOI: 10.1038/s41392-022-00999-9. View

10.

Luo H, Zhu G, Xu J, Lai Q, Yan B, Guo Y . HOTTIP lncRNA Promotes Hematopoietic Stem Cell Self-Renewal Leading to AML-like Disease in Mice. Cancer Cell. 2019; 36(6):645-659.e8. PMC: 6917035. DOI: 10.1016/j.ccell.2019.10.011. View

11.

Seong B, Dharia N, Lin S, Donovan K, Chong S, Robichaud A . TRIM8 modulates the EWS/FLI oncoprotein to promote survival in Ewing sarcoma. Cancer Cell. 2021; 39(9):1262-1278.e7. PMC: 8443273. DOI: 10.1016/j.ccell.2021.07.003. View

12.

Olsen S, Godfrey L, Healy J, Choi Y, Kai Y, Hatton C . MLL::AF9 degradation induces rapid changes in transcriptional elongation and subsequent loss of an active chromatin landscape. Mol Cell. 2022; 82(6):1140-1155.e11. PMC: 9044330. DOI: 10.1016/j.molcel.2022.02.013. View

13.

Mirzaei S, Gholami M, Hushmandi K, Hashemi F, Zabolian A, Canadas I . The long and short non-coding RNAs modulating EZH2 signaling in cancer. J Hematol Oncol. 2022; 15(1):18. PMC: 8892735. DOI: 10.1186/s13045-022-01235-1. View

14.

Wang W, Han C, Sun Y, Chen Z, Fang K, Huang W . Activation of the Lysosome-Associated Membrane Protein LAMP5 by DOT1L Serves as a Bodyguard for MLL Fusion Oncoproteins to Evade Degradation in Leukemia. Clin Cancer Res. 2019; 25(9):2795-2808. DOI: 10.1158/1078-0432.CCR-18-1474. View

15.

Isakson P, Bjoras M, Boe S, Simonsen A . Autophagy contributes to therapy-induced degradation of the PML/RARA oncoprotein. Blood. 2010; 116(13):2324-31. DOI: 10.1182/blood-2010-01-261040. View

16.

Abba M, Fabre M, Lee J, Tatineni P, Kil H, Aldaz C . Modulated Pathways in Early-Stage Breast Cancer Progression. Front Oncol. 2021; 11:783211. PMC: 8637884. DOI: 10.3389/fonc.2021.783211. View

17.

Carter J, Hege K, Yang J, Kalpage H, Su Y, Edwards H . Targeting multiple signaling pathways: the new approach to acute myeloid leukemia therapy. Signal Transduct Target Ther. 2020; 5(1):288. PMC: 7746731. DOI: 10.1038/s41392-020-00361-x. View

18.

Huang W, Zeng Z, Wang W, Sun Y, Chen Y, Luo X . A CRISPR/CAS9-based strategy targets the personalized chimeric neosequence in fusion-driven cancer genome for precision medicine. Clin Transl Med. 2021; 11(3):e355. PMC: 7967915. DOI: 10.1002/ctm2.355. View

19.

Huang W, Sun Y, Pan Q, Fang K, Chen X, Zeng Z . The snoRNA-like lncRNA LNC-SNO49AB drives leukemia by activating the RNA-editing enzyme ADAR1. Cell Discov. 2022; 8(1):117. PMC: 9622897. DOI: 10.1038/s41421-022-00460-9. View

20.

Zhao R, Fu J, Zhu L, Chen Y, Liu B . Designing strategies of small-molecule compounds for modulating non-coding RNAs in cancer therapy. J Hematol Oncol. 2022; 15(1):14. PMC: 8817562. DOI: 10.1186/s13045-022-01230-6. View