Molecular Cancer Therapeutics最新文献

Small cell lung cancer (SCLC) is a recalcitrant thoracic malignancy known for acquired chemoresistance, early metastatic spread, and poor overall survival. Lurbinectedin, a DNA minor groove alkylating agent, provides durable efficacy in a minority. Predictive biomarkers for lurbinectedin are needed. Patients with relapsed SCLC who received lurbinectedin (n=16) were classified by cycles received, including eight durable responders defined as ≥8 cycles (average, 14.75 cycles; median PFS, 9.8 months). Pretreatment specimens were analyzed by immunohistochemistry (IHC) for SLFN11 and tandem mass tag (TMT)-labeled expression proteomics. Top candidates were confirmed by IHC and functionally validated in SCLC cell lines. SLFN11 failed to predict lurbinectedin response (P = 0.40). Proteomics highlighted a primitive neuroendocrine pathway (ISL1, SOX5, SIX1, SIX4). ISL1 expression significantly correlated with lurbinectedin response (r = 0.65, P = 0.0351). IHC confirmed lurbinectedin reduced ISL1 post-treatment. Lurbinectedin preferentially induced DNA damage in ISL1 "high" SCLC (P <0.0001) without causing neuroendocrine subtype switching. RNA sequencing showed downregulation of ISL1, RBMS3, ASCL1, SOX5, SIX1, and upregulation of ATF3. ISL1 "high" SCLC demonstrated cellular dependency on ISL1; ISL1 knockdown reduced lurbinectedin sensitivity. L-MYC positively regulated ISL1, while ISL1 positively regulated ASCL1 and SOX5. This is the first comprehensive investigation of predictive biomarkers for lurbinectedin. Proteomics identified ISL1 as defining a novel SCLC subtype with enhanced lurbinectedin sensitivity. ISL1 serves as both a predictive biomarker and functional dependency, as evidenced by essentiality for cell survival and loss following treatment. Prospective studies using ISL1 as a predictive biomarker for lurbinectedin are planned.

Chromobox 2 (CBX2), a subunit of Polycomb Repressor Complex 1 (PRC1), is expressed in high-grade serous carcinoma. CBX2 inhibitory peptide (CBX2i) has demonstrated efficacy in a syngeneic mouse model, but has limitations. We sought to identify an alternative approach to CBX2 inhibition. A computational-based molecular docking screen was performed using the SelleckChem Bioactive library to identify inhibitors of CBX2. A similarity screen of top hits against the bound conformation of CBX2i pharmacophore model was performed in parallel. A series of in vitro validation studies evaluated the effect of alisertib on proliferation, a CBX2 target gene, and stemness. CBX2 knockdown cell lines and a syngeneic murine model were utilized to evaluate alisertib response in the context of CBX2 loss. Cell target engagement assay was performed. PRC1-activity was measured by H2AK119ub levels. Immune profiling of treated tumors defined the immune microenvironment. The computational-based screen identified 10 candidate compounds. In vitro validation narrowed compounds of interest to raltitrexed, alisertib, GTX-007, LY315920, and PD0325901. Ultra-low dilution assay demonstrated dramatic decrease in spheroid formation with alisertib, an aurora A kinase (AURKA) inhibitor. Good structural overlap was observed between CBX2i and alisertib. Cell target engagement assay confirmed alisertib selectivity for both aurora A kinase and CBX2. Loss of CBX2 attenuated alisertib efficacy in vitro and in vivo. Treatment with alisertib leads to decrease in H2AK119ub and shift in the immune tumor microenvironment. Alisertib efficacy in HGSC is dependent on functional CBX2 and cell target engagement confirms selectivity for CBX2, supporting that alisertib activity involves CBX2 inhibition.

PD-1 immune checkpoint inhibition (ICI) is ineffective in most cancer patients. However, combination therapy can improve response rates, with the checkpoint TIGIT being a particularly interesting candidate as it is expressed on tumor-infiltrating exhausted T and NK cells. TIGIT's primary ligand, PVR, is overexpressed in many cancers and both TIGIT and PVR correlate with poor prognosis. To therapeutically exploit this, we developed a novel therapeutic termed Dual Signaling Protein 502 (DSP502). DSP502 is composed of the extracellular domains of TIGIT and PD-1, each fused to human IgG1 Fc containing knob-in-hole mutations. DSP502 was designed to simultaneously block PVR/TIGIT and PD-L1/PD-1 by binding to cancer cell-expressed PVR and PD-L1. Moreover, the human IgG1 domain can recruit FcR-positive effector cells to further reactivate anticancer immunity. Treatment with DSP502 potentiated NK cell activation and boosted the anticancer cytotoxicity of peripheral blood mononuclear cells (PBMCs) and tumor-infiltrating lymphocytes (TILs) from NSCLC and metastatic colorectal cancer patients towards cancer cells expressing both PD-L1 and PVR. Transcriptomic analysis confirmed NSCLC as a potential target, showing co-expression of TIGIT and PD-1 on a high percentage of exhausted CD8+ T cells. Notably, treatment with DSP502 not only blocked checkpoint signaling but also preserved surface expression of the co-stimulatory PVR ligand, DNAM-1, on T and NK cells. Finally, DSP502 inhibited tumor growth by potentiating antitumor immunity in xenograft ovarian and lung cancer models. Collectively, these findings demonstrate that DSP502, by blocking PVR and PD-L1 pathways, has dual ICI activity and holds potential therapeutic benefits for cancers such as NSCLC.

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.