Therapeutics
Abstract
Thiopurines are anticancer agents used for the treatment of leukemia and autoimmune diseases. These purine analogs are characterized by a narrow therapeutic index because of the risk of myelosuppression. With the discovery of NUDIX hydrolase 15 (NUDT15) as a major modulator of thiopurine metabolism and toxicity, we sought to comprehensively examine all members of the NUDIX hydrolase family for their effect on the pharmacologic effects of thiopurine. By performing a NUDIX-targeted CRISPR/Cas9 screen in leukemia cells, we identified NUDT5, whose depletion led to drastic thiopurine resistance. NUDT5 deficiency resulted in a nearly complete depletion of active metabolites of thiopurine and the loss of thioguanine incorporation into DNA. Mechanistically, NUDT5 deletion resulted in substantial alteration in purine nucleotide biosynthesis, as determined by steady-state metabolomics profiling. Stable isotope tracing demonstrated that the loss of NUDT5 was linked to a marked suppression of the purine salvage pathway but with minimal effects on purine de novo synthesis. Finally, we comprehensively identified germline genetic variants in NUDT5 associated with thiopurine-induced myelosuppression in 582 children with acute lymphoblastic leukemia. Collectively, these results pointed to NUDT5 as a key regulator of the thiopurine response primarily through its effects on purine homeostasis, highlighting its potential to inform individualized thiopurine therapy.
Authors
Maud Maillard, Rina Nishii, Hieu S. Vu, Kashi R. Bhattarai, Wenjian Yang, Jing Li, Ute Hofmann, Daniel Savic, Smita Bhatia, Matthias Schwab, Min Ni, Jun J. Yang
Abstract
Nuclear size is crucial for cellular functions and often increases with malignancy. Irregular nuclei are linked to aggressive tumors, driven by genetic and epigenetic changes. However, the precise mechanisms controlling nuclear size are still not fully understood. In this study, we demonstrated that cancer-associated speckle-type POZ protein (SPOP) mutations enlarged nuclear size by reducing the protein level of lamin B2 (LMNB2), a key nuclear integrity protein. Mechanistically, SPOP bound to LMNB2 and promoted its mono-ubiquitination at lysine-484, which protected it from degradation by the E3 ubiquitin ligase WD repeat domain 26. SPOP mutations disrupted this process, leading to reduced LMNB2 levels and impaired nuclear envelope (NE) integrity. This compromised NE was more vulnerable to damage from farnesyltransferase inhibitors (FTIs), causing nuclear rupture in SPOP-mutant tumor cells. This study identified SPOP as a positive regulator of nuclear size; the findings suggest tumors with SPOP mutations may be vulnerable to FTI-based therapies.
Authors
Zixi Wang, Lei Li, Qi Ye, Yuzeshi Lei, Mingming Lu, Leihong Ye, Jialu Kang, Wenyue Huang, Shan Xu, Ke Wang, Jing Liu, Yang Gao, Chenji Wang, Jian Ma, Lei Li
Abstract
Contemporary cancer treatment strategies are shifting toward targeted therapies to improve efficacy and minimize toxicity. Here, we report the design and preclinical evaluation of MBRC-101, a first-in-class antibody-drug conjugate (ADC) targeting EphA5, a receptor tyrosine kinase with an established role in embryonic development but not extensively studied in cancer. We show that EphA5 is expressed in multiple solid tumors, including cancers of the aerodigestive (non–small cell lung, head and neck, gastric, colon, and pancreatic) and genitourinary (bladder and ovary) tracts, as well as most breast cancer subsets (including triple-negative tumors), with limited expression in normal tissues. MBRC-101 is a humanized anti-EphA5 antibody conjugated to monomethyl auristatin E (MMAE) through a ThioBridge, thereby ensuring stable drug-to-antibody ratio and reducing off-target effects. MBRC-101 showed potent antitumor activity, achieving complete tumor regression in several patient-derived xenograft models. Preclinical Good Laboratory Practice–compliant toxicology studies in rats and nonhuman primates demonstrated that MBRC-101 is well tolerated, with observed toxicities limited to known MMAE off-target effects. These findings establish EphA5 as a therapeutic target in cancer and support the translational development of MBRC-101 as a promising ADC candidate for clinical evaluation, currently in a first-in-human multicenter investigational trial for patients with advanced solid tumors (ClinicalTrials.gov, NCT06014658).
Authors
Fernanda I. Staquicini, Fenny H.F. Tang, Vanessa de Oliveira, Sun-Young Kim, Ethan R. Chen, Christopher Markosian, Daniela I. Staquicini, Yongjian Wu, J. Kellogg Parsons, Kirstin F. Barnhart, Stephen C. Alley, Isan Chen, Wadih Arap, Renata Pasqualini
Abstract
There is growing evidence for direct actions of follicle–stimulating hormone (FSH) on tissues other than the ovaries and testes. Blocking FSH action, either genetically or pharmacologically, protects against bone loss, fat gain, and memory loss in mice. We thus developed a humanized FSH–blocking antibody––MS-Hu6––as a lead therapeutic for three diseases of public health magnitude––osteoporosis, obesity and Alzheimer’s disease (AD) that track together in post–menopausal women. Here, we report the crystal structure of MS-Hu6 and its interaction with FSH in atomistic detail. Using our Good–Laboratory–Practice–Compliant platform (21CFR58), we formulated MS-Hu6 and the murine equivalent Hf2 at an ultra–high concentration; both formulated antibodies displayed enhanced thermal and colloidal stability. A single injection of 89Zr–labelled MS-Hu6 revealed a beta–phase t½ of 89 and 131 hours for female and male mice, respectively, with retention in regions of interest. Female mice injected subcutaneously with Hf2 displayed a dose–dependent reduction in body weight and body fat. Hf2 also rescued recognition memory and spatial learning loss in a context– and time–dependent manner in AD–prone 3xTg and APP/PS1 mice. MS-Hu6 injected into African green monkeys (8 mg/kg) intravenously, and then subcutaneously at monthly intervals, was safe, and without effects on vitals, blood chemistries or blood counts. There was a notable ~4% weight loss in all four monkeys after the first injection, which continued in two of four monkeys. We thus provide IND–enabling data towards an upcoming first–in–human study.
Authors
Anusha R. Pallapati, Funda Korkmaz, Satish Rojekar, Steven Sims, Anurag Misra, Judit Gimenez–Roig, Aishwarya Gangadhar, Victoria Laurencin, Anissa Gumerova, Uliana Cheliadinova, Farhath Sultana, Darya Vasilyeva, Liam Cullen, Jonathan Schuermann, Jazz Munitz, Hasni Kannangara, Surabhi Parte, Georgii Pevnev, Guzel Burganova, Zehra Tumoglu, Ronit Witztum, Soleil Wizman, Natan Kramskiy, Liah Igel, Fazilet Sen, Anna Ranzenigo, Anne Macdonald, Susan Hutchison, Abraham J.P. Teunissen, Heather Burkart, Mansi Saxena, Yelena Ginzburg, Ki Goosens, Weibin Zhou, Vitaly Ryu, Ofer Moldavski, Orly Barak, Michael Pazianas, John Caminis, Shalender Bhasin, Richard Fitzgerald, Se-Min Kim, Matthew Quinn, Shozeb Haider, Susan Appt, Tal Frolinger, Clifford J. Rosen, Daria Lizneva, Yogesh K. Gupta, Tony Yuen, Mone Zaidi
Abstract
Triple-negative breast cancer (TNBC) represents the most malignant subtype of breast cancer. The clinical application of PARP inhibitors (PARPi) is limited by the low frequency of BRCA1/2 mutations in TNBC. Here, we identified that MTAP deletion sensitized genotoxic agents in our clinical cohort of metastatic TNBC. Further study demonstrated that MTAP deficiency or inhibition rendered TNBC susceptibility to chemotherapeutic agents, particularly PARPi. Mechanistically, targeting MTAP that synergized with PARPi by disrupting the METTL16-MAT2A axis involved in methionine metabolism and depleting in vivo s-adenosylmethionine (SAM) levels. Exhausted SAM in turn impaired PARPi-induced DNA damage repair through attenuation of MRE11 recruitment and end resection by diminishing MRE11 methylation. Notably, brain metastatic TNBC markedly benefited from a lower dose of PARPi and MTAP deficiency/inhibition synergy due to the inherently limited methionine environment in the brain. Collectively, our findings revealed a feed-forward loop between methionine metabolism and DNA repair through SAM, highlighting a therapeutic strategy of PARPi combined with MTAP deficiency/inhibition for TNBC.
Authors
Xiangyu Zeng, Fei Zhao, Xinyi Tu, Yong Zhang, Wen Yang, Jing Hou, Qi Jiang, Shouhai Zhu, Zheming Wu, Yalan Hao, Lingxin Zhang, Richard M. Weinshilboum, Kaixiong Tao, Liewei Wang, Zhenkun Lou
Abstract
Tumor-associated macrophages (TAMs) are abundant in the tumor microenvironment (TME) and dampen the immune response, negatively affecting patient survival. Therefore, targeting TAMs could address the limitations of current cancer treatments. However, drug development in this area remains limited. The Leukocyte-associated Immunoglobulin-like Receptor-1 (LAIR1), also called CD305, is prominently expressed on the surface of TAMs. We have uncovered a previously unrecognized immunosuppressive LAIR1 → Factor XIII A (FXIII-A) → Collagen IV pathway across various cancer types. Inhibition of LAIR1, either through knockout (Lair1–/–), antibody blockade (aLAIR1), or a chimeric antigen receptor (CAR) design (3-in-1 CAR by combining tumor targeting, T cell trafficking, and remodeling of the immunosuppressive TME in one CAR construct) provides enhanced antitumor response. LAIR1 inhibition enhances peripheral and intratumoral CD8 memory T-cell populations, induces a phenotypic shift of M2-like Macrophages towards M1, and normalizes tumor collagen IV and structural components in the TME, facilitating effective tumor-T cell interactions and tumor suppression. Enhanced antitumor responses were observed when Lair1–/– or aLAIR1 was used alone or combined with CAR T cells or when the 3-in-1 CAR T cells were used solely in chemotherapy-radiation-PD-1 blockade-resistant tumor models. These findings position LAIR1 inhibition as a promising strategy for cancer immunotherapies.
Authors
Haipeng Tao, Dongjiang Chen, Changlin Yang, Duy T. Nguyen, Georges Abboud, Ruixuan Liu, Tianyi Liu, Avirup Chakraborty, Alicia Y. Hou, Nicole A. Petit, Muhammad Abbas, Robert W. Davis, Janie Zhang, Christina Von Roemeling, Mohammed O. Gbadamosi, Linchun Jin, Tongjun Gu, Tuo Lin, Pengchen Wang, Alfonso Pepe, Diego Ivan Pedro, Hector R. Mendez-Gomez, Chao Xie, Aida Karachi, Frances Weidert, Dan Jin, Chenggang Wang, Kaytora Long-James, Elizabeth K. Molchan, Paul Castillo, John A. Ligon, Ashley P. Ghiaseddin, Elias J. Sayour, Maryam Rahman, Loic P. Deleyrolle, Betty Y.S. Kim, Duane A. Mitchell, W. Gregory Sawyer, Jianping Huang
Abstract
Gene replacement therapies mediated by adeno-associated viral (AAV) vectors represent a promising approach for treating genetic diseases. However, their modest packaging capacity (~4.7 kb) remains an important constraint and significantly limits their application for genetic disorders involving large genes. A prominent example is Duchenne muscular dystrophy (DMD), whose protein product dystrophin is generated from an 11.2 kb segment of the DMD mRNA. Here, we explored methods that enable efficient expression of full-length dystrophin via triple AAV co-delivery. This method exploits the protein trans-splicing mechanism mediated by split inteins. We identified a combination of efficient and specific split intein pairs that enables the reconstitution of full-length dystrophin from three dystrophin fragments. We show that systemic delivery of low doses of the myotropic AAVMYO1 in mdx4cv mice leads to efficient expression of full-length dystrophin in the hindlimb, diaphragm, and heart muscles. Notably, muscle morphology and physiology were significantly improved in triple AAV-treated mdx4cv mice versus saline-treated controls. This method shows the feasibility of expressing large proteins from several fragments that are delivered using low doses of myotropic AAV vectors. It can be adapted to other large genes involved in disorders for which gene replacement remains challenged by the modest AAV cargo capacity.
Authors
Hichem Tasfaout, Timothy S. McMillen, Theodore R. Reyes, Christine L. Halbert, Rong Tian, Michael Regnier, Jeffrey S. Chamberlain
Abstract
MYCN amplification accounts for the most common genetic aberration in neuroblastoma and strongly predicts the aggressive progression and poor clinical prognosis. However, clinically effective therapies that directly target N-Myc activity are limited. N-Myc is a transcription factor, and its stability are tightly controlled by ubiquitination-dependent proteasomal degradation. Here, we discovered that Kelch-like protein 37 (KLHL37) played a crucial role in enhancing the protein stability of N-Myc in neuroblastoma. KLHL37 directly interacted with N-Myc to disrupt the N-Myc/FBXW7 interaction, thereby stabilizing N-Myc and enabling tumor progression. Suppressing KLHL37 effectively induced the degradation of N-Myc and exhibited a profound inhibitory effect on the growth of MYCN-amplified neuroblastoma. Notably, we identified RTA-408 as an inhibitor of KLHL37 to disrupt KLHL37-N-Myc complex, promoting the degradation of N-Myc and suppressing neuroblastoma in vivo and in vitro. Moreover, we elucidated the therapeutic potential of RTA-408 for neuroblastoma by utilizing the PDC and PDX tumor models. RTA408's anti-tumor effects may not be exclusively via KLHL37, and specific KLHL37 inhibitors are expected to be developed in the future. These findings not only uncover the biological function of KLHL37 in regulating N-Myc stability, but also indicate that KLHL37 inhibition is a promising therapeutic regimen for neuroblastoma, especially in MYCN-amplified patients.
Authors
Senfeng Xiang, Pengfei Chen, Xiaoxian Shi, Hanqi Cai, Zihan Shen, Luyang Liu, Aixiao Xu, Jianhua Zhang, Xingya Zhang, Shaowei Bing, Jinhu Wang, Xuejing Shao, Ji Cao, Bo Yang, Qiaojun He, Meidan Ying
Abstract
CAR-T cells are a powerful yet expensive tool in cancer immunotherapy. While their use in targeting hematological malignancies is well-established, using a single CAR-T cell therapy to treat both hematological and solid tumors, which can reduce cost, remains largely unexplored. In this study, we identified CD155, an adhesion molecule that is upregulated during tumor progression, as a target for CAR-T cell therapy in both leukemia and solid tumors. We engineered CAR-T cells using human and mouse anti-CD155 antibodies generated from a Berkeley Lights' Beacon platform. These CAR-T cells demonstrated potent anti-tumor activity, significantly reducing tumor burden in preclinical models of acute myeloid leukemia (AML), non-small cell lung cancer (NSCLC), and pancreatic cancer. To reduce potential allogeneic rejection, we generated CAR-T cells using humanized anti-CD155 antibody sequences that retained efficacy. Additionally, murine CAR-T cells targeting mouse CD155 exhibited limited toxic side effects in immunocompetent mice, highlighting the favorable safety profile of this therapy. These findings suggest that CD155 can be targeted by CD155 CAR-T cells safely and effectively, representing an innovative cellular therapeutic strategy that has the potential to expand its scope across both AML and multiple solid tumors, thereby lowering the cost of cellular immunotherapy, especially as allogenic, universal and off-the-shelf CAR-T cell therapies advance to the clinic.
Authors
Tianchen Xiong, Ge Wang, Peng Yu, Zhenlong Li, Debao Li, Jianying Zhang, Song Lu, Ruiqi Yang, Xiaolong Lian, Jianhong Mi, Rui Ma, Zhiyao Li, Guido Marcucci, Tingting Zhao, Michael A. Caligiuri, Jianhua Yu
Abstract
Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) are used to treat BRCA-mutated (BRCAm) cancer patients; however, resistance has been observed. Therefore, biomarkers to indicate PARPi resistance and combination therapy to overcome that are urgently needed. We identified a high prevalence of activated FGF receptor 3 (FGFR3) in BRCAm triple-negative breast cancer (TNBC) cells with intrinsic and acquired PARPi resistance. FGFR3 phosphorylated PARP1 at tyrosine 158 (Y158) to recruit BRG1 and prolong chromatin-loaded MRE11, thus promoting homologous recombination (HR) to enhance PARPi resistance. FGFR inhibition prolonged PARP trapping and synergized with PARPi in vitro and in vivo. High-level PARP1 Y158 phosphorylation (p-Y158) positively correlated with PARPi resistance in TNBC patient-derived xenograft models, and in PARPi-resistant TNBC patient tumors. These findings reveal that PARP1 p-Y158 facilitates BRG1-mediated HR to resolve the PARP-DNA complex, and PARP1 p-Y158 may indicate PARPi resistance that can be relieved by combining FGFR inhibitors (FGFRi) with PARPi. In summary, we show that FGFRi restores PARP trapping and PARPi antitumor efficacy in PARPi-resistant breast cancer by decreasing HR through the PARP1 p-Y158/BRG1/MRE11 axis, suggesting that PARP1 p-Y158 is a biomarker for PARPi resistance that can be overcome by combining FGFRi with PARPi.
Authors
Mei-Kuang Chen, Hirohito Yamaguchi, Yuan Gao, Weiya Xia, Jeffrey T. Chang, Yu-Chun Hsiao, Tewodros W. Shegute, Zong-Shin Lin, Chen-Shiou Wu, Yu-Han Wang, Jennifer K. Litton, Qingqing Ding, Yongkun Wei, Yu-Yi Chu, Funda Meric-Bernstam, Helen Piwnica-Worms, Banu Arun, Jordi Rodon Ahnert, Jinsong Liu, Jun Yao, Wei-Chao Chang, Hung-Ling Wang, Coya Tapia, Constance T. Albarracin, Khandan Keyomarsi, Shao-Chun Wang, Ying-Nai Wang, Gabriel N. Hortobagyi, Chunru Lin, Liuqing Yang, Dihua Yu, Mien-Chie Hung
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ISSN: 0021-9738 (print), 1558-8238 (online)