Molecular Cancer Therapeutics最新文献

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.

Most of the triple negative phenotype or basal-like molecular subtypes of breast cancers are associated with aggressive clinical behaviour and show poor disease prognosis. Current treatment options are constrained, emphasizing the need for novel combinatorial therapies for this particular tumor subtype. Our group has demonstrated that functionally active p21 activated kinase 1 (PAK1) exhibits significantly higher expression levels in clinical triple negative breast cancer (TNBC) samples compared to other subtypes, as well as adjacent normal tissues. Low PAK1 expression in TNBC was significantly linked to better prognosis, with improved overall survival (OS, p=0.00236) and relapse-free survival (RFS, p=0.0314), as shown by GOBO analysis. To confirm the role of PAK1 as a therapeutic target and to discover novel synergistic chemotherapy drug combinations, we conducted a drug combination screen using triple negative breast cancer cell lines and a mouse metastatic tumor cell line. We identified the combined inhibition of PAK1 inhibitor, NVS-PAK1 with doxorubicin/paclitaxel/methotrexate as a synergistic novel therapeutic approach for treating metastatic TNBC to improve overall survival. This study also indicated a reduction in the effective dosage of the chemotherapeutic drug when combined with NVS-PAK1. Our study demonstrates that combining NVS-PAK1 with each of the chemotherapeutic drugs' doxorubicin, paclitaxel, and methotrexate resulted in decreased colony formation, reduced wound healing capability, and diminished migratory and invasive potential in both TNBC cell lines and 4T1 in vitro. These findings were further validated in orthotopic mouse mammary tumors, confirming that simultaneous PAK1 inhibition alongside chemotherapy significantly enhanced anti-tumor efficacy and reduced metastasis.

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.

Chimeric antigen receptor (CAR) T cells represent a novel targeted approach to overcome deficits in the ability of the host immune system to detect and subsequently eradicate tumors. The identification of antigens expressed specifically on the surface of tumor cells is a critical first step for a targeted therapy that selectively targets cancer cells without affecting normal tissues. 5T4 is a tumor-associated antigen expressed on the cell surface of most solid tumors. However, very little is known about its expression in hematologic malignancies. In this study, we assess the expression of 5T4 in different types of leukemias, specifically acute myeloid leukemia (AML), and normal hematopoietic stem cells (HSC). We also provide an in vitro assessment of safety and efficacy of 5T4-targeting CAR T cells against HSCs and AML tumor cell lines. 5T4 expression was seen in about 50% of AML cases; AML with mutated nucleophosmin 1, AML-myelodysplasia-related, and AML not otherwise specified showed the highest percentage of 5T4+ cases. 5T4 CAR T cells efficiently and specifically killed AML tumor cell lines, including leukemic stem cells. Coculture of 5T4 CAR T cells with HSCs from healthy donors showed no impact on subsequent colony formation, thus confirming the safety profile of 5T4. A proof-of-concept study using a murine model for AML demonstrated that CAR T cells recognize 5T4 expressed on cells and can kill tumor cells both in vitro and in vivo. These results highlight 5T4 as a promising target for immune intervention in AML and that CAR T cells can be considered a powerful personalized therapeutic approach to treat AML.

Acute myeloid leukemia (AML) is a hematologic malignancy with limited treatment options and a high likelihood of recurrence after chemotherapy. We studied N-myristoylation, the myristate modification of proteins linked to survival signaling and metabolism, as a potential therapeutic target for AML. N-myristoylation is catalyzed by two N-myristoyltransferases (NMT), NMT1 and NMT2, with varying expressions in AML cell lines and patient samples. We identified NMT2 expression as a marker for survival of patients with AML, and low NMT2 expression was associated with poor outcomes. We used the first-in-class pan-NMT inhibitor, zelenirstat, to investigate the role of N-myristoylation in AML. Zelenirstat effectively inhibits myristoylation in AML cell lines and patient samples, leading to degradation of Src family kinases, induction of endoplasmic reticulum stress, apoptosis, and cell death. Zelenirstat was well tolerated in vivo and reduced the leukemic burden in an ectopic AML cell line and in multiple orthotopic AML patient-derived xenograft models. The leukemia stem cell-enriched fractions of the hierarchical OCI-AML22 model were highly sensitive to myristoylation inhibition. Zelenirstat also impairs mitochondrial complex I and oxidative phosphorylation, which are critical for leukemia stem cell survival. These findings suggest that targeting N-myristoylation with zelenirstat represents a novel therapeutic approach for AML, with promise in patients with currently poor outcomes.