Molecular Cancer Therapeutics最新文献

Anaplastic thyroid cancer (ATC) is a rare but severe form of thyroid cancer responsible for approximately 50% of thyroid cancer deaths. Consequently, the identification of innovative therapies remains crucial for the effective treatment of ATC. Molecular radiotherapy is a rapidly growing field within oncology and the cell surface antigen CD44v6, which is overexpressed in several cancers, is a plausible target for molecular radiotherapy of ATC. Immunohistochemistry (IHC) of 39 ATC patient samples were evaluated for CD44v6 expression. Biodistribution and dosimetry of 125I/177Lu-labeled UU-40, a CD44v6 specific antibody, followed by in vivo efficacy in two ATC xenograft models with varying target expression levels (ACT-1 and BHT-101) accompanied by SPECT-imaging evaluated radiolabeled UU-40 for therapeutic efficiency in ATC xenografts. The IHC revealed CD44v6 immunoreactivity in 46% of ATC patient samples. The biodistribution favored 177LuUU-40 over the 125I-labeled antibody and confirmed in vivo specificity of both radioconjugates. The in vivo efficacy and accompanied SPECT imaging of a moderate CD44v6-expressing xenograft model (BHT-101) verified the tumor specificity as well as the target-specific effect of 177Lu -UU-40 on tumor growth and survival. A 100% complete response rate was demonstrated as a result of therapy using a single dose of 16 MBq 177Lu -UU-40 in a high CD44v6-expressing xenograft model (ACT-1), and SPECT-imaging revealed excellent tumor uptake of the radioconjugate at 14 days post-injection. This study verifies the expression of CD44v6 in ATC and cements the superiority and promise of 177Lu -UU-40 over 131I-UU-40 for antibody-based molecular radiotherapy of CD44v6-positive ATC.

Increased PI3K signaling as a result of PIK3CA mutation or amplification or decreased expression of PTEN (phosphatase and tensin homolog deleted on chromosome 10) is one of the most common alterations in head and neck squamous cell carcinoma (HNSCC). PTEN negatively regulates PI3K signaling and its downstream effectors including COX2. COX2 mediates the synthesis of PGE2 which contributes to immunosuppression in the tumor microenvironment. PGE2 also binds to one or more EP receptors (EP1-EP4) and promotes the growth of tumor cells via activation of EP2 and EP4. However, the role of PGE2 in PTEN-deficient HNSCC is incompletely understood. Here, we assessed PGE2 signaling in PTEN-deficient HNSCC and evaluated the effect of aspirin or TPST-1495, a dual EP2/EP4 antagonist, on the growth of PTEN knockout (KO) and PIK3CA-altered HNSCC tumors in immunocompetent mice. Our results demonstrated that aspirin selectively inhibits the growth of PTEN KO HNSCC tumors. TPST-1495 inhibited tumor growth and substantially increased the anti-tumor activity of the immune checkpoint inhibitor anti-PD1. To date, there are no FDA-approved therapies for PI3K pathway-altered HNSCC. Our findings suggest that NSAIDs demonstrate anti-tumor activity in PTEN-deficient or PI3K-altered tumors whereas EP2/EP4 targeting may augment FDA-approved anti-PD1 therapy in HNSCC.

Radiopharmaceutical therapy (RPT) is a promising approach to treating solid tumors, but therapeutic advances are impeded by the lack of broadly expressed targets and shared molecular vulnerability across different tumor types. We evaluate VLA-4 (integrin α4β1) as a potential target for RPT in solid tumors using radiolabeled copper-64 ([64Cu]Cu-) and copper-67 ([67Cu]Cu-CB-TE1A1P-PEG4-LLP2A) LLP2A, a peptidomimetic ligand of VLA-4, for preclinical imaging and RPT testing. Expression analysis of ITGA4, encoding the alpha 4 subunit of VLA-4, revealed overexpression in hematological malignancies and various solid tumors compared to healthy tissue. Flow cytometry showed medium to high VLA-4 expression in 77% of tested cancer cell lines. PET/CT imaging with [64Cu]Cu-LLP2A demonstrated tracer uptake in tumors and lymphoid tissues. In toxicity studies, [67Cu]Cu-LLP2A administered at 37-74 MBq was well-tolerated, causing only thymic atrophy without long-term hematological or tissue toxicity. Tumor dose response was observed in B16-F10 melanoma models. Using orthotopic syngeneic models (B16-F10, B78, 4T1, GL261, TH-MYCN, and E2A-PBX1) and human cancer models (SK-MEL-37, 143B, and IMR-5), we conducted PET/CT imaging and biodistribution studies, with selected models used for [64Cu]Cu-LLP2A dosimetry calculations. Given VLA-4's broad expression across cancer tissues, demonstrated on-target effects, acceptable toxicity profile, and favorable dosimetry in preclinical models, further investigation of [67Cu]Cu-LLP2A as an RPT agent is warranted.

Mutations in the tyrosine kinase domain of the Anaplastic Lymphoma Kinase (ALK) oncogene in neuroblastoma occur most frequently at one of three hotspot amino acid residues, with the F1174* and F1245* variants conferring de novo resistance to first and second generation ALK inhibitors including crizotinib and ceritinib. Lorlatinib, a third generation ALK/ROS inhibitor, overcomes de novo resistance and induces complete and sustained tumor regressions in patient-derived xenograft (PDX) models unresponsive to crizotinib. Lorlatinib has now completed Phase 1 testing in children and adults with relapsed/refractory ALK-driven neuroblastoma and entered pivotal Phase 3 testing within the Children's Oncology Group. To define mechanisms underlying the superior activity of lorlatinib, we utilized a chemical proteomics approach to quantitatively measure functional kinome dynamics in response to lorlatinib and crizotinib in clinically relevant ALK-driven neuroblastoma PDX models. Lorlatinib was a markedly more potent inhibitor of ALK and preferentially downregulated several kinases implicated in G2/M cell cycle transition compared to crizotinib. Lorlatinib treatment also led to the repression of MYCN expression and its occupancy at promoters of the same G2/M kinases. These data providing mechanistic insight into the superior efficacy of lorlatinib over crizotinib for the treatment of ALK-driven neuroblastoma.

Trophoblast cell surface antigen 2 (TROP2) is highly expressed in multiple cancers relative to normal tissues, supporting its role as a target for cancer therapy. OBI-992 is an antibody-drug conjugate (ADC) derived from a novel TROP2-targeted antibody linked to the topoisomerase 1 (TOP1) inhibitor exatecan via an enzyme-cleavable hydrophilic linker, with a drug-antibody ratio of 4. This study evaluated and compared the antitumor activity of OBI-992 with that of benchmark TROP2-targeted ADCs datopotamab deruxtecan (Dato-DXd) and sacituzumab govitecan (SG) in cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) models. OBI-992 treatment exhibited statistically significant antitumor activity versus controls at doses of 3 and 10 mg/kg in various CDX and PDX models, demonstrating comparable or better antitumor activity with benchmark ADCs. In a large-tumor model, longer survival times were observed in OBI-992-treated mice compared with Dato-DXd-treated mice. OBI-992 treatment induced marked bystander killing of TROP2-negative cells in the presence of nearby TROP2-positive cells in both in vitro and in vivo studies. In lung adenocarcinoma CDX models with overexpression of either P-glycoprotein (P-gp) or breast cancer resistance protein (BCRP) to mimic ATP-binding cassette transporter-mediated multidrug resistance, OBI-992 treatment maintained antitumor activity when Dato-DXd treatment became less effective. The combination of OBI-992 at suboptimal doses with either poly (ADP-ribose) polymerase (PARP) inhibitors or an immune check point inhibitor produced synergistic antitumor effects in mouse models. Taken together, these translational results support further development of OBI-992 as a cancer therapy.

Over the past two decades, the "hallmarks of cancer" have revolutionized cancer research and highlighted the crucial roles of inflammation and immunity. Protumorigenic inflammation promotes cancer development along with inhibition of antitumor immunity, shaping the tumor microenvironment (TME) toward a tumor-permissive state and further enhancing the malignant potential of cancer cells. This immunosuppressive TME allows tumors to evade immunosurveillance. Thus, understanding the complex interplay between tumors and the immune system within the TME has become pivotal, especially with the advent of immunotherapy. Although immunotherapy has achieved notable success in many malignancies, primary liver cancer, particularly hepatocellular carcinoma, presents unique challenges. The hepatic immunosuppressive environment poses obstacles to the effectiveness of immunotherapy, along with high mortality rates and limited treatment options for patients with liver cancer. In this review, we discuss current understanding of the complex immune-mediated mechanisms underlying liver neoplasms, focusing on hepatocellular carcinoma and liver metastases. We describe the molecular and cellular heterogeneity within the TME, highlighting how this presents unique challenges and opportunities for immunotherapy in liver cancers. By unraveling the immune landscape of liver neoplasms, this review aims to contribute to the development of more effective therapeutic interventions, ultimately improving clinical outcomes for patients with liver cancer.

Although cancer immunotherapy has yielded encouraging outcomes in hematologic malignancies, it has faced challenges in achieving the same level of effectiveness in numerous solid tumors, primarily because of the presence of immunosuppressive tumor microenvironments (TME). The immunosuppressive qualities of the TME have generated considerable interest, making it a focal point for treatments aimed at enhancing immune responses and inhibiting tumor progression. Fibroblast activation protein (FAP), an attractive candidate for targeted immunotherapy, is prominently expressed in the TME of various solid tumors. IL12, recognized as a key mediator of immune responses, has been explored as a potential candidate for cancer treatment. Nevertheless, initial efforts to administer IL12 systemically demonstrated limited efficacy and notable side effects, emphasizing the necessity for innovation. To address these concerns, our molecules incorporated specific IL12 mutations, called IL12mut, which reduced toxicity. This study explored the therapeutic potential of the FAP-IL12mut TMEkine-a novel immunotherapeutic agent selectively engineered to target FAP-expressing cells in preclinical cancer models. Our preclinical results, conducted across diverse murine cancer models, demonstrated that FAP-IL12mut significantly inhibits tumor growth, enhances immune cell infiltration, and promotes a shift toward a cytotoxic immune activation profile. These findings suggest that FAP-IL12mut could offer effective cancer treatment strategies.

The treatment of non-small cell lung cancer has made major strides with the use of immune checkpoint inhibitors; however, there remains a significant need for therapies that can overcome immunotherapy resistance. Dendritic cell (DC) vaccines have been proposed as a therapy that can potentially enhance the antitumor immune response. We have embarked on a phase I clinical trial of a vaccine consisting of monocyte-derived DCs (moDC) modified to express the chemokine C-C motif chemokine ligand 21 (CCL21-DC) given in combination with pembrolizumab. In this study, we report a comprehensive characterization of this CCL21-DC vaccine and interrogate the effects of multiple factors in the manufacturing process. We show that the cellular makeup of the CCL21-DC vaccine is heterogeneous because of the presence of passenger lymphocytes at a proportion that is highly variable among patients. Single-cell RNA sequencing of vaccines revealed further heterogeneity within the moDC compartment, with cells spanning a spectrum of DC phenotypes. Transduction with a CCL21-containing adenoviral vector augmented CCL21 secretion by moDCs, but otherwise had a minimal effect on vaccine characteristics. A single freeze-thaw cycle for stored vaccines was associated with minor alterations to the DC phenotype, as was the use of healthy donors rather than patient autologous blood. Our results highlight important considerations for the production of DC vaccines and identify underexplored factors that may affect their efficacy and immunologic impact.

Antibody-drug conjugates (ADC) are a rapidly advancing category of therapeutic agents with notable anticancer efficacy. However, the emergence of interstitial lung disease as a severe ADC-associated adverse event highlights the need to better understand the underlying mechanisms. In this study, xenograft model mice with tumors expressing different levels of the trophoblast antigen 2 (TROP2) were generated by subcutaneously transplanting the various TROP2-expressing cancer lines. The mice received different doses of TROP2-eribulin, a novel TROP2-targeting ADC, composed of an anti-TROP2 antibody and the eribulin payload, joined by a cleavable linker. The concentration and distribution of TROP2-eribulin, as well as the pharmacokinetics of eribulin release, were assessed in tumor and lung tissues. Analysis of tumor tissue showed that the concentration of released eribulin was approximately 10-fold higher in NCI-H2110 (high TROP2 expression) than in A549 (low TROP2 expression), whereas analysis of lung tissue showed that TROP2-eribulin was distributed in lung tissue in a dose-dependent manner, regardless of TROP2 expression, with significantly more eribulin released in the high-dose group than in the other dose groups (P < 0.05). Immunofluorescence assay analysis showed that TROP2-eribulin localized to alveolar macrophages. In the analysis using human leukemia monocytic cell, the concentration of eribulin released from TROP2-eribulin was significantly reduced by the use of an Fc receptor inhibitor (P < 0.05). These results revealed that Fcγ receptor-mediated uptake by alveolar macrophages releases the cytotoxic payload into lung tissue, helping to clarify the pathogenesis of ADC-induced interstitial lung disease.

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an inherited cancer syndrome caused by germline pathogenic variants in the fumarate hydratase (FH) gene. Affected individuals are at risk for developing cutaneous and uterine leiomyomas and aggressive FH-deficient renal cell carcinoma (RCC) with a papillary histology. Due to a disrupted tricarboxylic acid cycle, FH-deficient kidney cancers rely on aerobic glycolysis for energy production, potentially creating compensatory metabolic vulnerabilities. This study conducted a high-throughput drug screen in HLRCC cell lines, which identified a critical dependency on nicotinamide adenine dinucleotide (NAD), a redox cofactor produced by the biosynthetic enzyme nicotinamide phosphoribosyltransferase (NAMPT). Human HLRCC tumors and HLRCC-derived cell lines exhibited elevated NAMPT expression compared with controls. FH-deficient HLRCC cells, but not FH-restored HLRCC or normal kidney cells, were sensitive to NAMPT inhibition. HLRCC cell line viability was significantly decreased in both 2D and 3D in vitro cultures in response to the clinically relevant NAMPT inhibitor OT-82. NAMPT inhibition in vitro significantly decreased the total amount of NAD+, NADH, NADP, NADPH, and poly-ADP-ribose levels, and the effects of NAMPT inhibition could be rescued by the downstream NAD precursor nicotinamide mononucleotide (NMN), confirming the on-target activity of OT-82. Moreover, NAMPT inhibition by OT-82 in two HLRCC xenograft models resulted in severely reduced tumor growth. OT-82 treatment of HLRCC xenograft tumors in vivo inhibited glycolytic flux as demonstrated by reduced lactate/pyruvate ratio in hyperpolarized 13C-pyruvate magnetic resonance spectroscopic imaging experiments. Overall, our data define NAMPT inhibition as a potential therapeutic approach for FH-deficient HLRCC-associated RCC.