Molecular Cancer Therapeutics最新文献

Aurora kinase A (AURKA) regulates cell cycle progression into and through mitosis. As overexpression of AURKA in cancer cells is common and associated with mitotic defects and aneuploidy, small molecule inhibitors of AURKA have been developed as candidate therapies for cancer. However, these have typically low activity in clinical trials, with systemic toxicities limiting dose escalation. To concentrate an AURKA inhibitor in tumors, we exploited the fact that cancer cells in solid tumors selectively express high levels of the chaperone HSP90 to counteract intratumoral stresses, providing a potential targeting moiety. We developed NN-01-195 as a novel chimeric small molecule that combines an AURKA inhibitor related to TAS-119/VIC-1911 with an HSP90-binding moiety related to SNX2112, and evaluated its function. NN-01-195 tightly binds and inhibits both AURKA and HSP90 in biochemical assays. In cancer cells, NN-01-195 causes mitotic arrest and spindle abnormalities, and a profile of signaling changes that closely resembles that of an AURKA inhibitor. ADME assessment indicates moderate metabolism in liver microsomes (T1/2 = 46.7 minutes) and sustained plasma exposure following single I.P. injection. Maximum tolerated repeated dose testing over 5 days indicates no weight loss or toxicity at 80 mg/kg. Importantly, NN-01-195 accumulates in xenografted tumors at higher levels and for longer duration than does an AURKA inhibitor. Further, in combination with an inhibitor of the G2/M checkpoint protein WEE1, NN-01-195 is more potent than VIC-1911 in limiting growth of xenograft tumors. These data support the exploration of NN-01-195 and improved analogs as promising new candidates for therapeutic evaluation.

Despite advances in cancer immunotherapies such as immune checkpoint blockade (ICB), durable patient responses remain constrained, which is largely due to the highly suppressive tumor immune microenvironment (TIME). Here, by analyzing pan-cancer patient cohorts and experimental validation, we found that MCT1 expression is broadly upregulated in malignant and myeloid compartments within the TIME. MCT1 expression is also associated with worse survival, suppressive TIME state, and poor treatment response to ICB therapy. Functionally, MCT1-mediated lactate uptake by tumor cells and tumor-associated macrophages (TAMs) suppresses CD8⁺ T cell activation, and cytotoxicity in the ex vivo co-culture models. Mechanistically, lactate exposure and uptake via MCT1 in tumor cells and TAMs induces IL-10 production, which contributes to the inhibition of the anti-tumor response of CD8⁺ T cells. Moreover, in MC38 and LLC mouse cancer models, pharmacologic MCT1 inhibition reprograms the immunosuppressive myeloid populations, improves CD8⁺ T cell infiltration and function, and triggers tumor regression. Therefore, these results indicate that MCT1 has the potential to be a biomarker for patients across cancer types, and to be a promising therapeutic target for enhanced cancer immunotherapy.

Bladder cancer is the most prevalent malignancy of the urinary tract, characterized by an unfavorable prognosis, elevated rates of recurrence, and a lack of targeted therapeutic approaches. In this research, we evaluated the efficacy of TAK-901, a specific inhibitor targeting Aurora kinase, and elucidate the anti-cancer mechanisms in bladder cancer. TAK-901 exhibited a dose-dependent inhibition of proliferation, colony formation, and migration, as well as induction of apoptosis in T24 and UMUC-3 cells. Additionally, bladder cancer cells undergo cell cycle arrest at the G2/M phase when exposed to TAK-901. Mechanistic studies revealed that the targeted inhibition of EGFR by TAK-901 impacted AKT and FOXO3a phosphorylation, leading to the activation of FOXO-dependent transcriptional activity, which subsequently triggered apoptotic pathways through inducing BIM expression. Furthermore, our study demonstrated that TAK-901 attenuated tumor growth in the UMUC-3-Luc xenograft model and significantly reduced Ki-67 expression in tumor tissues. Finally, we propose a novel treatment strategy involving the synergistic inhibition of bladder cancer cell growth by combining TAK-901 with Afatinib. Our research strongly suggests that Aurora A and Aurora B are promising epigenetic therapeutic targets in bladder cancer. Furthermore, TAK-901 can function as a targeted kinase inhibitor and EGFR inhibitor for the treatment of bladder cancer by activating the FOXO signaling pathway, which induces apoptosis in bladder cancer cells.

Patients with poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) face a much poorer prognosis than those with differentiated thyroid cancers. Around 25% of PDTCs and 35% of ATCs carry the BRAFV600E mutation, which constitutively activates the MAPK pathway, a key driver of cell growth. Although combining BRAF and MEK inhibitors can shrink tumors, resistance often develops. The exact cause of this resistance remains unclear. We previously found that in PDTC and ATC cells, the BRAFV600E mutation is strongly linked to the expression of ETV5, a transcription factor downstream of the MAPK pathway. In the current study, we observed a significant association between ETV5 expression and the activation of p38, a central component of the MAPK14 pathway. Upon reduction of ETV5 levels, p38 expression and activation decreased, along with its upstream regulators MKK3/MKK6. This suggests that the MAPK and p38/MAPK14 pathways are interconnected and that p38 has oncogenic properties in these cancers. Using high-throughput screening, we established that combining p38 inhibitors with the BRAF inhibitor dabrafenib showed strong synergy in vitro, including in cells resistant to dabrafenib and trametinib that had acquired a secondary TP53 mutation. We then tested this combination in a genetically engineered mouse model of ATC. Overall, our findings suggest an oncogenic link between the MAPK and p38/MAPK14 pathways and that combining p38 pathway inhibitors with dabrafenib-targeted therapy could improve treatment outcomes for aggressive thyroid cancers. However, more specific and effective p38 inhibitors are required to fully harness this potential.

Cancer immunotherapy has been revolutionized through the implementation of the state-of-the-art "chimeric antigen receptor" (CAR)-mediated therapies. CAR-based technologies, which encompass CAR T cells, CAR macrophages, and CAR-NK cells, show great promise in the treatment of various cancers. Despite the success of CAR-based therapies in treating malignancies, they face numerous challenges, including dysfunction of effector innate and adaptive immune cells, immunosuppressive tumor microenvironment (TME), antigen heterogeneity, and on-target/off-tumor bio-toxicity. The CD47/SIRPα axis is recognized as a critical innate immune checkpoint and is important in regulating myeloid-derived clearance of tumor cells and the innate-adaptive cells' cross-talk in cancer immunity. This signaling axis has risen as a promising target to boost the CAR-based immunotherapies by overcoming phagocytic inhibition and modulating immune evasion. This narrative review explores the integration of CD47/SIRPα modulation as an adjunct to CAR therapies. CD47/SIRPα immune-modulation revealed its potential to boost infiltration, persistence, and phagocytic activity of the immune cells. However, its blockade also poses challenges, including hematologic toxicities, CAR T cell clearance, and compensatory escape pathways. Future work will depend on selective targeting, combinatorial checkpoint modulation, and engineered CAR designs that preserve safety while unlocking durable responses. Herein, we discuss pre-clinical and clinical advancements, safety considerations, and cutting-edge advancements.

Due to the paucity of validated cell surface osteosarcoma-specific targets, patients with this condition have long been excluded from the benefits of antibody-drug conjugate (ADC) therapy observed in patients with several solid and hematologic malignancies. Our comprehensive surfaceome profiling approach previously identified osteosarcoma-specific cell-surface antigens that are highly expressed in osteosarcomas but minimally expressed in normal tissues. As a result, one such antigen, CADM1, was selected for the generation of an ADC. We tested a CADM1-targeting ADC with a tesirine payload (SG3249) in vitro in osteosarcoma, rhabdomyosarcoma, and neuroblastoma patient-derived xenograft cell lines. In vivo, we tested six CADM1-expressing osteosarcoma patient-derived xenograft models. The CADM1 ADC demonstrated significant antitumor activity in vitro across the osteosarcoma, rhabdomyosarcoma, and neuroblastoma cell lines. Additionally, it effectively reduced tumor volume and extended event-free survival in all six osteosarcoma PDX models tested. Notably, the CADM1 ADC achieved a major complete response in one model (OS2), complete responses in two models (OS1 and OS33), and partial responses in three models (OS9, OS17, and OS31). Based on these results, clinical development of CADM1-targeted therapies for osteosarcoma and other CADM1-expressing pediatric solid tumors may be warranted.

As many as 90% of human pancreatic ductal adenocarcinoma (PDAC) tumors harbor gain-of-function mutations in the KRAS oncogene. Recently, inhibitors of the most common KRAS mutation, KRASG12D, have entered the clinical arena. However, early evidence suggests that as monotherapy, KRASG12D inhibitors such as MRTX1133 at best provide brief periods of disease stabilization. Hence, there is a growing interest in understanding the mechanisms through which tumors acquire resistance to KRAS inhibition. In the present study, we generated in vitro models of MRTX1133 resistance and subjected parental and drug-resistant cell lines to RNA sequencing. This suggested that MRTX1133-resistant tumor cells undergo a global shift toward histone acetylation. Inhibition of the histone acetyltransferase EP300 reversed the drug-resistant phenotype in vitro, which subsequent RNA sequencing experiments determined was associated with the suppression of pro-survival FOSL1 signaling. Accordingly, siFOSL1 reversed the MRTX1133-resistant phenotype with similar effects on pro-survival signaling. Given the lack of clinically useful EP300 or FOSL1 inhibitors, we next explored whether inhibitors of the acetylation scanning BET proteins would be similarly effective. The addition of BET inhibitors re-sensitized several resistant cell lines to MRTX1133 and impaired FOSL1-mediated survival signaling in vitro. In murine models of MRTX1133-resistant PDAC, BET inhibition cooperated with MRTX1133 to markedly extend overall survival. As BET inhibitors are currently under clinical testing, the combination of MRTX1133 and BET inhibitors warrants further investigation, particularly in tumors that have developed resistance to KRAS inhibition.

PROTACs are bivalent molecules that simultaneously bind to proteins of interest and cellular ubiquitin E3 ligases to promote target degradation. Tumor-specific expression of E3 should increase therapeutic efficacy and reduce toxicity in cancer therapy applications. The E3 ligases currently employed during PROTAC design such as CRBN, VHL, c-IAP and MDM2 are ubiquitously expressed and not considered tumor-specific. However, MDM2 is part of the p53 negative feedback loop and is dynamically regulated at transcriptional and post-translational levels. MDM2 gene amplification occurs at 4-20% frequency in multiple tumor types. To investigate whether MDM2 can serve as tumor-specific PROTAC E3 in certain setting, we analyzed the benchmark compound A1874 (JQ1-Idasanutlin chimera targeting BRD4) under various conditions that affect MDM2 expression and activity. The results showed that A1874 activity is dependent on p53-mediated induction of MDM2 expression and is inactive in cells with mutant p53. Importantly, A1874 showed on average ~12-fold higher potency in tumor cells with MDM2 amplification compared to non-amplified cells, correlating with enhanced cytotoxicity. The results suggest that tumors with MDM2 amplification or overexpression can be selectively targeted using PROTAC approach.

Effective treatment for metastatic cancer has remained elusive due to the persistence of drug-resistant metastasis stem cells (MetSCs) that drive relapse. MetSCs are tumor cell subpopulations enriched for their ability to reinitiate and sustain metastatic growth, displaying phenotypic plasticity and resistance to chemotherapy. These cells express the L1 cell adhesion molecule (L1CAM), a transmembrane protein detected in numerous human solid tumor types and at multiple disseminated organ sites. As a selective surface marker of MetSCs, L1CAM is a promising candidate for molecularly targeted drugs aimed at eliminating metastases, yet strategies to date have not achieved clinical success. Here, we develop antibody-drug conjugates (ADCs) to deliver highly toxic PNU-159682 payloads to L1CAM-expressing cells. We report the generation of monoclonal antibodies (mAb) with high binding affinity, specificity and selectivity for the human L1CAM extracellular domain. Optimized L1CAM-targeting mAbs were conjugated to PNU-159682 to generate ADC variants with both cleavable and non-cleavable linkers, with an average drug-antibody-ratio (DAR) of four. ADCs derived from three antibodies targeting various epitopes of the L1CAM extracellular portion potently killed cells exhibiting varying levels of surface L1CAM expression. L1CAM ADCs given as monotherapy resulted in robust tumor control and extended survival in mice harboring subcutaneous L1CAM+ xenografts or L1CAM+ lung metastases from triple-negative basal breast cancer and lung adenocarcinoma. Safety analyses with mouse cross-reactive antibodies indicate a feasible therapeutic window. Our findings offer strong proof-of-concept to support the preclinical development of these novel L1CAM ADCs as therapeutic agents for advanced solid tumors.

Radiation remains a primary treatment for glioblastoma (GBM), yet tumors frequently recur within 2 years. In this study, orthotopic xenografts initiated from glioma stem-like cells (GSC) implanted into the right striatum of nude mice were used to investigate the biology of recurrent GBM. In this model, untreated tumors showed diffuse growth pattern across the right hemisphere and olfactory bulb (OB), whereas postirradiation tumors (10 Gy) regrew predominantly within the OB, exhibiting increased cell density and a well-demarcated border indicative of an altered growth pattern. Transcriptomes of untreated and recurrent tumors were assessed using spatial profiling. Comparison of gene expression across regions of interest revealed that recurrent tumors are less heterogeneous and exhibit a distinct transcriptional profile compared with untreated tumors. A total of 463 genes were differentially expressed, and gene set enrichment analysis revealed significant enrichment of pathways related to cell-cycle regulation in the recurrent as compared with untreated tumors. Further analysis of those pathways revealed a significant upregulation of 22 proteasome-related genes in recurrent tumors. Moreover, functional assays revealed significantly higher proteasome activity in recurrent compared with untreated tumors, suggesting the proteasome as a potential therapeutic target unique to recurrent GBM. To evaluate the therapeutic relevance, mice were treated with the combination of radiation followed by the proteasome inhibitor ixazomib. Whereas ixazomib had no effect on untreated tumors, its administration after irradiation significantly prolonged survival in two GSC xenograft models. These results illustrate how defining molecular alterations that develop in recurrent GBM xenografts can lead to the identification of a novel therapeutic target.