Page 94 - Haematologica Vol. 109 - July 2024

ARTICLE - Targeting TNF/IL-17/MAPK in hE2A-PBX1 zebrafish H. Luo et al.
the insufficient dose of WT E2A affects the regulation of lymphangiogenesis development.50,51 On the other hand, hE2A-PBX1 induces oncogenic properties, such as cell pro- liferation, by altering the expression of downstream genes or transcriptional co-activators of PBX1.52 In our study, the induction of hE2A-PBX1 expression, along with the regu- lar expression of the endogenous E2A gene, leads to the development of myeloid leukemia. This suggests that the acquired function of hE2A-PBX1, rather than a deficiency of WT E2A, is the primary cause of its carcinogenic poten- tial. However, disruption of the E2A gene may contribute to alterations in lymphoid development. Consistent with this, an unbiased analysis of E2A-PBX1 cistrome in pre-B ALL cells reveals that E2A-PBX1 can interact with RUNX1, resulting in transcriptome alterations, including activation of RUNX1 itself.1 Moreover, our study revealed aberrant activation of Runx1 in hE2A-PBX1 transgenic fish. Notably, inhibiting Runx1 and its downstream pathway demonstrated significant alleviation in the expansion of leukemic cells in both zebrafish and human cell lines. These findings emphasize that hE2A-PBX1 exerts a significant impact on tumorigenesis by regulating the genome through direct binding with RUNX1. Whether this effect is synergistically facilitated by the inappropriate activation of target genes through the fusion of PBX1 DNA binding motifs remains to be further investigated.
Currently, there are no clinically targeted drugs for the treat- ment of E2A-PBX1 leukemia, and there are relatively few studies on the treatment of E2A-PBX1-associated AML-like disease and MPAL. In this study, we show that the small mole- cule compounds KJ-Pyr-9, OUL35 and CID44216842 obtained by hE2A-PBX1 zebrafish leukemia model have great potential. OUL35, recognized as a selective PARP inhibitor that targets PKCδ, a PARP substrate that activates MAPK,53,54 has demon- strated the ability to protect HeLa cells from ARTD10-induced cell death.55 KJ-Pyr-9 is an inhibitor of MYC,56 a transcriptional regulatory factor encoded by the common proto-oncogene MYC, which mainly exerts its regulatory effects through binding with MAX protein.57 Notably, the expression of max was significantly increased in hE2A-PBX1 zebrafish (data not shown). Literature reports indicate that KJ-Pyr-9 can target MYC to inhibit pleomorphic glioblastoma multiforme (GBM) and significantly reduce the viability of squamous cell carcinoma (SCC) and adenocarcinoma (AC)-derived cells.58 CID44216842 acts as an inhibitor of RAS, a key regulator of signaling pathways controlling normal cell growth and ma- lignant transformation. Additionally, CID44216842 has been demonstrated to inhibit stimulus-induced Cdc42 activation
References
1. Pi W-C, Wang J, Shimada M, et al. E2A-PBX1 functions as a coactivator for RUNX1 in acute lymphoblastic leukemia. Blood. 2020;136(1):11-23.
in Swiss 3T3 fibroblasts.59 While in vitro cellular experiments confirm their efficacy in tumor cell therapy, it is essential to conduct experiments using animal tumor models before progressing to clinical trials. In our study, these three small molecule compounds exhibit the ability to alleviate hE2A- PBX1-induced AML-like disease in zebrafish as well as pre-B ALL associated with hE2A-PBX1, by targeting the TNF/IL-17/ MAPK pathway downstream of Runx1. However, it is not clear whether these small molecule compounds are applicable to other blood diseases with abnormal RUNX1 activity, and more preclinical animal studies are needed to confirm this. Overall, our findings shed new light on the treatment of E2A-PBX1 and other Runx1-related disorders. Although there is much work to be done, we anticipate that our research will contribute to the development of innovative therapeutic strategies for these diseases.
Disclosures
No conflicts of interest to disclose.
Contributions
WL and WZ conceived and supervised the study and edited the article. HL and QL performed experiments and wrote, reviewed, and edited the article. JH, WD, KW, SL, and HW per- formed the experiments. ZH reviewed and edited the article.
Acknowledgments
The authors would like to thank Dr. Huafeng Xie for providing RCH-ACV cells. The authors would like to thank Dr. Kailun Li, Dr. Xiao Fang, Dr. Panpan Zhu, Dr Shuang Zhao and Dr. Zhibin Huang for their helpful suggestions.
Funding
This work was supported by the National Natural Science Foundation of China (82070163), Guangdong Basic and Applied Basic Research Foundation (2020A1515011218) and Special Fund of Science and Technology Innovation Culti- vation for College Students in Guangdong Province (pd- jh2020b0048).
Data-sharing statement
The data supporting the findings of this study are avail- able within the article and its Online Supplementary Ap- pendix. Data produced in this manuscript are available on Gene Expression Omnibus (GEO) with accession number GSE234222 (Go to https://www.ncbi.nlm.nih.gov/geo/query/ acc.cgi?acc=GSE234222, enter the token qjebmoqwprsjtkn into the box).
2. Duque-Afonso J, Lin CH, Han K, et al. E2A-PBX1 remodels oncogenic signaling networks in B-cell precursor acute lymphoid leukemia. Cancer Res. 2016;76(23):6937-6949.
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