Molecular Cancer Therapeutics最新文献

Up to 90% of high-grade serous ovarian cancer (HGSC) patients will develop resistance to platinum-based chemotherapy, posing substantial therapeutic challenges due to a lack of universally druggable targets. Leveraging BenevolentAI's AI-driven approach to target discovery, we screened potential AI-predicted therapeutic targets mapped to unapproved tool compounds in patient-derived 3D models. This identified TNIK, which is modulated by NCB-0846, as a novel target for platinum-resistant HGSC. Targeting by this compound demonstrated efficacy across both in vitro and ex vivo organoid platinum-resistant models. Additionally, NCB-0846 treatment effectively decreased Wnt activity, a known driver of platinum resistance; however, we found that these effects were not solely mediated by TNIK inhibition. Comprehensive AI, in silico, and in vitro analyses revealed CDK9 as another key target driving NCB-0846's efficacy. Interestingly, TNIK and CDK9 co-expression positively correlated, and chromosomal gains in both served as prognostic markers for poor patient outcomes. Combined knockdown of TNIK and CDK9 markedly diminished downstream Wnt targets and reduced chemotherapy-resistant cell viability. Furthermore, we identified CDK9 as a novel mediator of canonical Wnt activity, providing mechanistic insights into the combinatorial effects of TNIK and CDK9 inhibition and offering a new understanding of NCB-0846 and CDK9 inhibitor function. Our findings identified the TNIK-CDK9 axis as druggable targets mediating platinum resistance and cell viability in HGSC. With AI at the forefront of drug discovery, this work highlights how to ensure that AI findings are biologically relevant by combining compound screens with physiologically relevant models thus supporting the identification and validation of potential drug targets.

Synthetic lethality approaches in BRCA1/2-mutated cancers have focused on poly(ADP-ribose) polymerase (PARP) inhibitors, which are subject to high rates of innate or acquired resistance in patients. Here, we used CRISPR/Cas9-based screening to identify DNA Ligase I (LIG1) as a novel target for synthetic lethality in BRCA1-mutated cancers. Publicly available data supported LIG1 hyperdependence of BRCA1-mutant cells across a variety of breast and ovarian cancer cell lines. We used CRISPRn, CRISPRi, RNAi, and protein degradation to confirm the lethal effect of LIG1 inactivation at the DNA, RNA, and protein level in BRCA1-mutant cells in vitro. LIG1 inactivation resulted in viability loss across multiple BRCA1-mutated cell lines, whereas no effect was observed in BRCA1/2 wild-type cell lines, demonstrating target selectivity for the BRCA1-mutant context. On-target nature of the phenotype was demonstrated through rescue of viability with exogenous wild-type LIG1 cDNA. Next, we demonstrated a concentration-dependent relationship of LIG1 protein expression and BRCA1 mutant cell viability using a titratable, degradable LIG1 fusion protein. BRCA1 mutant viability required LIG1 catalytic activity, as catalytically dead mutant LIG1K568A failed to rescue viability loss caused by endogenous LIG1 depletion. LIG1 perturbation produced proportional increases in PAR staining in BRCA1 mutant cells, indicating a mechanism consistent with the function of LIG1 in sealing ssDNA nicks. Finally, we confirmed LIG1 hyperdependence in vivo using a xenograft model in which LIG1 loss resulted in tumor stasis in all mice. Our cumulative findings demonstrate that LIG1 is a promising synthetic lethal target for development in patients with BRCA1 mutant cancers.

In situ immunization (ISI) has emerged as a promising approach to bolster early phases of the cancer immunity cycle through improved T cell priming. One class of ISI agents, oncolytic viruses (OVs), has demonstrated clinical activity, but overall benefit remains limited. Mounting evidence suggests that due to their inherent vulnerability to antiviral effects of type I interferon (IFN), OVs have limited activity in solid tumors expressing stimulator of interferon genes (STING) and/or retinoic acid-inducible gene I (RIG-I). Here, using a combination of pharmacologic, genetic, and in vivo approaches, we demonstrate that VAX014, a bacterial minicell-based oncolytic ISI agent, activates both STING and RIG-I and leverages this activity to work best in STING- and/or RIG-I-positive tumors. Intratumoral treatment of established syngeneic tumors expressing STING and RIG-I with VAX014 resulted in 100% tumor clearance in two mouse models. Antitumor activity of VAX014 was shown to be dependent on both tumor-intrinsic STING and RIG-I with additive activity stemming from host-intrinsic STING. Analysis of human solid tumor datasets demonstrated STING and RIG-I co-expression is prevalent in solid tumors and associates with clinical benefit in many indications, particularly those most amenable to intratumoral administration. These collective findings differentiate VAX014 from OVs by elucidating the ability of this agent to elicit antitumor activity in STING- and/or RIG-I-positive solid tumors and provide evidence that STING/RIG-I agonism is part of VAX014's mechanism of action. Taken together, this work supports the ongoing clinical investigation of VAX014 treatment as an alternative to OV therapy in patients with solid tumors.

TIGIT and PVRIG are immune checkpoints co-expressed on activated T and NK cells, contributing to tumor immune evasion. Simultaneous blockade of these pathways may enhance therapeutic efficacy, positioning them as promising dual targets for cancer immunotherapy. This study aimed to develop a bispecific antibody (BsAb) to co-target TIGIT and PVRIG. Expression of TIGIT and PVRIG was assessed on tumor-infiltrating lymphocytes (TILs) from patients with various cancers, including non-small cell lung cancer (n=63) and colorectal cancer (n=26). The BsAb was engineered by fusing anti-PVRIG nanobodies to the N terminus of anti-TIGIT antibodies. Functional characterization of the BsAb was performed in vitro and in vivo, including assessments of T and NK cell activation and cytotoxicity. Pharmacokinetics and safety profiles were evaluated in cynomolgus monkeys. Statistical analyses were conducted using the Student's t-test. The results showed that the BsAb effectively blocked TIGIT and PVRIG from binding their respective ligands, CD155 and CD112, leading to significant increases in T cell activation (2.8-fold, p<0.05) and NK cell cytotoxicity (1.8-fold, p<0.05). In vivo, the BsAb demonstrated potent anti-tumor activity, both as a monotherapy and in combination with anti-PD-1 or anti-PD-L1, in humanized PBMC and transgenic mouse models. Pharmacokinetic studies in cynomolgus monkeys revealed a favorable profile, with no dose-limiting toxicities observed after four repeated doses of 200 mg/kg. These findings provide compelling preclinical evidence for the therapeutic potential of targeting the TIGIT-PVRIG axis with a bispecific antibody. This approach shows promise for enhancing anti-tumor immunity and warrants further investigation in clinical trials.

Myeloid malignancies include various types of cancers that arise from abnormal development or proliferation of myeloid cells within the bone marrow. Chimeric antigen receptor (CAR) T cell treatments, which show great potential for B cell and plasma cell cancers, face major challenges when used for myeloid malignancies. CAR natural killer (NK) cell-based immunotherapy encounters several challenges in treating myeloid cancers, including: (1) poor gene transfer efficiency and expansion platforms in vitro, (2) limited proliferation and persistence in vivo, (3) antigenic heterogeneity, and (4) an immunosuppressive tumor microenvironment. Despite these hurdles, "off-the-shelf" CAR-NK treatments showed encouraging results, marked by enhanced proliferation, prolonged persistence, enhanced tumor infiltration, and improved adaptability. This review offers a summary of the biological traits and cellular sources of NK cells along with a discussion of contemporary CAR designs. Furthermore, it addresses the challenges observed in preclinical research and clinical trials of CAR-NK cell therapy for myeloid cancers, suggesting enhancement strategies.

Mutations in the KRAS oncogene can mediate resistance to radiation. KRAS mutation (mut) driven tumors have been reported to express cancer stem cell (CSC)-like features and may harbor metabolic liabilities through which CSC-associated radioresistance can be overcome. We established a radiation/drug screening approach that relies on the growth of 3D spheres under anchorage-independent and lipid-limiting culture conditions, which promote stemness and lipogenesis. In this format, we screened 32 KRASmut-enriched lung cancer models. As predicted from published data, CB-839, a glutaminase inhibitor, displayed the highest degree of radiosensitization in KRASmut models with LKB1 co-mutations. Radiosensitization by inhibition of stearoyl-CoA desaturase-1, SCD1, displayed a similar genotype preference though the data also implicated KEAP1 co-mutation and SCD1 expression as potential predictors of radiosensitization. In an isogenic model, KRASmut cells were characterized by increased SCD1 expression and a higher ratio of monounsaturated fatty acids (MUFA) to saturated fatty acids. Accordingly, pharmacological inhibition or depletion of SCD1 radiosensitized isogenic KRASmut but not wild-type cells. The radiosensitizing effect was notably small, especially compared to several DNA repair inhibitors. As an alternative strategy to targeting MUFA metabolism, adding polyunsaturated FAs (PUFA) phenocopied some aspects of SCD1 inhibition, suppressed tumor growth in vivo, and opposed the CSC-like phenotype of KRASmut cells. In conclusion, we report a 3D screening approach that recapitulates clinically relevant features of KRASmut tumors and can be leveraged for therapeutic targeting of metabolic vulnerabilities. Our data highlight pronounced inter-tumoral heterogeneity in radiation/drug responses and the complexity of underlying genomic dependencies.

Ovarian clear cell carcinoma (OCCC), particularly advanced or recurrent settings, is generally resistant to platinum-based chemotherapy, warranting novel therapeutic strategies. Mutations in the phosphoinositide 3-kinase/protein kinase B/mechanistic target of rapamycin kinase (PI3K/AKT/mTOR) pathway are frequently reported in OCCC. Therefore, we hypothesized that the PI3K/mTOR dual inhibitor, GSK458, and arsenic trioxide may exert synergistic anti-tumor effects on OCCC. We investigated the effects of GSK458, arsenic trioxide, and the combination of GSK458 and arsenic trioxide on cell viability, colony formation, and apoptosis in seven OCCC cells. Mechanistically, transcriptomic differences were assessed among the groups. Additionally, their anti-tumor effects were evaluated on the three-dimensional cultures of OCCC patient-derived xenografts as well as in vivo. Low-dose combination of GSK458 and arsenic trioxide exerted synergistic anti-tumor effects in vitro. Viability of the three-dimensional OCCC patient-derived xenograft cultures treated with the combination of GSK458 and arsenic trioxide decreased to 23.8% of that of the control. RNA sequencing revealed that the mechanism was associated with cell cycle and DNA damage repair. The combination of GSK458 and arsenic trioxide synergistically inhibited the PI3K/AKT/mTOR pathway and angiogenesis and increased apoptosis. Compared to any monotherapy, the combination treatment significantly suppressed tumor growth in vivo, thereby enhancing survival. Overall, our findings highlight the potential of the novel combination of GSK458 and arsenic trioxide combination for OCCC treatment.

Despite remarkable advances in cancer treatment, most solid cancers remain difficult to cure. We recently developed an antibody-drug conjugate (ADC, 84-EBET) for pancreatic cancer by using the carcinoembryonic-antigen-related cell-adhesion molecule 6 (CEACAM6) antibody #84.7 and the bromodomain and extra-terminal (BET) protein degrader EBET. Here, we showed the overexpression of CEACAM6 in colorectal, lung, and breast cancers (CRC, LC, BC) and the broad-spectrum efficacy of 84-EBET in mouse models of these cancers. In vitro assays using cancer organoids and cell lines of CRC, LC, and BC revealed that 84-EBET was more potent than ADCs with known approved payloads-DXd, SN38, and monomethyl auristatin E (MMAE)-or standard chemotherapies. In mouse studies, a single injection of 84-EBET induced marked regression of CRC-, LC-, and BC-patient-derived xenograft tumors and cell-line-derived xenograft tumors. Moreover, in mouse syngeneic CRC, LC, and BC models resistant to PD-1 antibody, the combination of 84-EBET and PD-1 antibody induced complete regression of most tumors. Mechanistically, 84-EBET degraded BRD4 protein in both cancer and stromal cells via bystander efficacy. It decreased stromal inflammatory phenotypes and increased activated T-cell numbers in tumors. These results demonstrate that delivering BET protein degraders to tumors and their microenvironments via a CEACAM6-targeted ADC may be effective against a wide range of solid cancers.

Osteosarcoma (OS) is the most common primary malignant bone tumor in childhood. Patients who present with metastatic disease at diagnosis or relapse have a very poor prognosis, and this has not changed over the past four decades. The Wnt signaling pathway plays a role in regulating osteogenesis and is implicated in OS pathogenesis. DKK-1 inhibits the canonical Wnt signaling pathway, causing inhibition of osteoblast differentiation and disordered bone repair. Our lab previously demonstrated that a monoclonal antibody against DKK-1 prevented metastatic disease in a mouse model. This study expands upon those findings by demonstrating similar results with a small molecule inhibitor of DKK-1, WAY262611, both in vitro and in vivo. WAY262611 was evaluated in vitro on osteosarcoma cell lines, including proliferation, caspase activation, cell cycle analysis, and signaling pathway activation. We utilized our orthotopic implantation-amputation model of osteosarcoma metastasis in vivo to determine the impact of WAY262611 on primary tumor progression and metastatic outgrowth of disseminated tumor cells. Differentiation status was determined using single cell RNA sequencing. We show here that WAY262611 activates canonical Wnt signaling, enhances nuclear localization and transcriptional activity of beta-catenin, and slows proliferation of OS cell lines. We also show that WAY262611 induces osteoblastic differentiation of an OS patient-derived xenograft in vivo, as well as inhibiting metastasis. This work credentials DKK-1 as a therapeutic target in OS, allowing for manipulation of the Wnt signaling pathway and providing preclinical justification for the development of new biologics for prevention of osteosarcoma metastasis.

Although heightened intratumoral levels of reactive oxygen species (ROS) are typically associated with a suppressive tumor microenvironment, under certain conditions ROS contribute to tumor elimination. Treatment approaches, including some chemotherapy and radiation protocols, increase cancer cell ROS levels that influence their mechanism of cell death and subsequent recognition by the immune system. Furthermore, activated myeloid cells rapidly generate ROS upon encounter with pathogens or infected cells to eliminate disease, and recently, this effector function has been noted in cancer contexts as well. Collectively, ROS-induced cancer cell death may help initiate adaptive antitumor immune responses that could synergize with current approved immunotherapies, for improved control of solid tumors. In this work, we explore the use of glucose oxidase, an enzyme which produces hydrogen peroxide, a type of ROS, to therapeutically mimic the endogenous oxidative burst from myeloid cells to promote antigen generation within the tumor microenvironment. We engineer the enzyme to target pan-tumor-expressed integrins both as a tumor-agnostic therapeutic approach and as a strategy to prolong local enzyme activity following intratumoral administration. We found the targeted enzyme potently induced cancer cell death and enhanced cross-presentation by dendritic cells in vitro and further combined with interferon alpha for long-term tumor control in murine MC38 tumors in vivo. Optimizing the single-dose administration of this enzyme overcomes limitations with immunogenicity noted for other prooxidant enzyme approaches. Overall, our results suggest ROS-induced cell death can be harnessed for tumor control and highlight the potential use of designed enzyme therapies alongside immunotherapy against cancer.