Molecular Cancer Therapeutics最新文献

Solute carrier family 16 member 2 (SLC16A2), also known as monocarboxylate transporter 8 (MCT8), is a member of the SLC16 family that exerts essential functions in the transport of elemental cell nutrients. This study explores the function of SLC16A2 in hepatocellular carcinoma (HCC) progression, particularly its impact on T cell function. We established Slc16a2 gene knockout (Slc16a2ko) C57BL/6 mice and injected H22 cells subcutaneously to analyze tumor growth and T cell activity in vivo. Additionally, Slc16a2fl/fl mice were crossed with Cd8aCre mice to obtain Slc16a2-Cd8a-ko mice, where Slc16a2 was specifically knocked out in CD8+T cells. In addition to subcutaneous models, luciferase-labeled H22 cells were injected into the liver lobe of mice for orthotopic models. SLC16A2 alteration did not affect proliferation or migration of mouse Hepa1-6 and H22 cells in vitro, though, tumorigenic activity of H22 cells was substantially reduced in Slc16a2ko and Slc16a2-Cd8a-ko C57BL/6 mice. Slc6a2 was highly expressed in Tex cells, and its expression in Tex, as well as the population of Tex cells in tumors, was increased by lactate or other chronic stimuli. An MCT8 monoclonal antibody (mAb) reduced lactate uptake by Tex cells, thus enhancing CD8+ T cell activity and reducing tumor growth in mice. The MCT8 mAb treatment also enhanced the efficacy of anti-PD-L1 in mice bearing tumors. This study supports that SLC16A2 contributes to Tex accumulation in association with increased lactate uptake and hampers immune activity in HCC, supporting SLC16A2 as a promising target to enhance immune activity in HCC management.

We previously used a myoblast model of fusion-positive rhabdomyosarcoma (FP-RMS) to show that FGF8, a PAX3-FOXO1 (P3F) transcriptional target, is required for P3F-driven tumorigenicity and, when aberrantly expressed, can maintain tumorigenicity in P3F-independent recurrent tumors. We report in this study that FGF8, FGFR1 and FGFR4 are often highly expressed in FP-RMS tumors. High FGF8 expression in FP-RMS cells is associated with high sensitivity to an FGFR4 inhibitor and a pan-FGFR inhibitor. While downregulating FGF8 resulted in loss of sensitivity to these inhibitors, FGF8 upregulation in myoblasts decreased FGFR4 expression and sensitized the cells to an FGFR1 inhibitor and a pan-FGFR inhibitor. FGF8 downregulation of FGFR4 expression was reverted by inhibitors of FGFR1, MEK or ERK, thus defining a signaling pathway by which FGF8 mediates this regulatory effect. Finally, high FGF8 expression in P3F-independent recurrent tumors was attributable to a rearrangement of viral LTR sequences into the FGF8 3' UTR region, resulting in increased FGF8 mRNA stability. These findings indicate that FGF8 exerts oncogenic effects in FP-RMS via FGFR4 and may exert oncogenic effects in P3F-independent relapses via FGFR1. Our study reveals the functional significance of FGF8 in FP-RMS and provides a rationale for preclinical studies of FGFR inhibitors in FP-RMS.

For HER2-positive advanced gastric cancer (GC), a recent major therapeutic advancement is the development of trastuzumab deruxtecan (T-DXd), a HER2-directed antibody-drug conjugate. In this disease, simultaneously targeting HER2 and HER3 pathways has the potential to be a promising therapeutic strategy. However, the therapeutic approach of combining T-DXd with pertuzumab, which disrupts HER2-HER3 heterodimerization, has not yet been explored in GC, making this study a pioneering effort. In vitro, T-DXd efficacy correlated with high levels of membrane HER2 expression. Among the 12 cell lines tested, two cell lines (NCI-N87 and OE19) confirmed as HER2 3+ by immunohistochemistry showed the most effective proliferation inhibition by T-DXd. When comparing NCI-N87 and OE19, HER2-HER3 dimerization was found to be more abundant in NCI-N87, and combination treatment with pertuzumab and T-DXd showed synergy in cell growth inhibition in NCI-N87, but not in OE19. NRG1 stimulation attenuated the antiproliferative effect of T-DXd. This attenuation of T-DXd activity by NRG1 was partially reversed by the addition of pertuzumab in NCI-N87, but not in OE19. Notably, the combination of T-DXd and pertuzumab enhanced membrane HER2 internalization more effectively in NCI-N87 than in OE19. In vivo mouse experiments using NCI-N87 cells showed the combination treatment significantly suppressed tumor growth compared to either monotherapy. Taken together, our findings suggest that dual targeting of HER2 and HER3 with T-DXd and pertuzumab may improve therapeutic outcomes in HER2-positive GC, particularly in tumors enriched with HER2-HER3 heterodimers. These preclinical data provide strong rationale for clinical trials evaluating this combination strategy in HER2-positive GC.

Lynch syndrome (LS) is characterized by the development of microsatellite instable (MSI) cancers that share neoantigens, offering an opportunity for targeted immunotherapy. NOUS-209 is a heterologous prime-boost cancer vaccine in clinical development, employing viral vectors encoding 209 shared neoantigen peptides derived from frameshift mutations (FSMs) commonly found in MSI tumors. In this study, we investigated the presence and dynamics of NOUS-209 targeted FSMs in both primary and metachronous LS-associated cancers. Whole-exome sequencing was performed for 73 tumors, including 58 colorectal cancers (CRC) and 15 urothelial cancers (UC), from 58 individuals with confirmed LS. A median of 57 FSMs per CRC and 24 FSMs per UC was observed, with similar FSM burdens in both primary and metachronous tumors. Analysis of nine matched primary-metachronous tumor pairs revealed evidence of immune editing: FSMs predicted to encode highly immunogenic neoepitopes were selectively lost in metachronous tumors, while those with lower predicted immunogenicity were retained. Importantly, all subsequent primary cancers acquired novel FSMs encoding neoantigens with strong predicted HLA-binding affinity, supporting the rationale for NOUS-209-mediated immune interception. These findings demonstrated that NOUS-209 FSMs are present in both CRCs and UCs in LS, expanding the therapeutic potential of NOUS-209 beyond CRC. Moreover, the emergence of novel targetable FSMs in metachronous tumors suggests that NOUS-209 immunotherapy may be effective in the prevention of both primary and metachronous LS-associated cancers.

Claudin18.2 (CLDN18.2)-targeted chimeric antigen receptor T (CAR-T) cell therapy has shown promising antitumor activity in gastrointestinal cancers. However, limited persistence in solid tumors and on-target off-tumor (OTOT) toxicity remain significant challenges. Here, we report on the preclinical development of a nanobody-based CLDN18.2-targeted CAR-T (IMC002) with effectiveness and safety in CLDN18.2-positive gastric and pancreatic cancer and present an efficacious clinical case. IMC002 exhibited robust antitumor activity and tolerability in multiple CLDN18.2-positive cell-derived xenograft and patient-derived xenograft models of gastric and pancreatic cancer with reduced OTOT toxicity. In vivo pharmacological studies revealed that peak concentrations of CAR gene DNA copies in total DNA in the tumor and lung tissues occurred on seven days after administration, while the peak in stomach tissues was observed an additional seven days later. Toxicity studies showed no obvious body weight loss induced by IMC002. The highest non-severely toxic dose was 5×108 CAR-T cells/kg. In the clinical case report, we present a case with unresectable advanced gastric cancer achieved pathological complete response 10 months after IMC002 infusion and no signs of recurrence were indicated in subsequent clinical and radiological follow-ups. IMC002 shows effectiveness and safety in CLDN18.2-positive gastric and pancreatic cancer and its favorable profiles support further clinical development.

Despite intensive, multimodal therapy, only half of children diagnosed with high-risk neuroblastoma will survive five years, and survivors harbor significant short- and long-term treatment-related co-morbidities. Although monoclonal antibody therapy targeting GD2 has improved outcomes, GD2-directed immunotherapy remains one of the only FDA-approved immunotherapies for pediatric cancer, and therapy is toxic due to GD2 expression on pain fibers. Thus, there is a critical need to uncover new immunotherapy targets in neuroblastoma. ALCAM is a cell adhesion molecule that promotes tumor growth in a variety of cancers and is highly expressed in neuroblastoma. We generated three inducible CRISPRi cell lines to deplete ALCAM and elucidate its role in neuroblastoma. Depletion of ALCAM reduced cell growth, reduced Ki-67 staining, and increased cleaved PARP. To determine the mechanism of ALCAM overexpression, we used ChIP-sequencing to show MYCN oncoprotein binding at the ALCAM promoter. We generated luciferase reporters from the ALCAM promoter and a putative upstream (10kb) enhancer, which we defined using Promoter-based Capture-C. Treatment with the MYC(N)/MAX dimerization inhibitor MYCi975 reduced ALCAM expression by immunoblotting and luciferase signal from the ALCAM promoter. We validated the activity of the upstream enhancer and uncovered an AP-1 binding motif that is critical for enhancer activity. Finally, as ALCAM is expressed in several normal tissues, we investigated an ALCAM-targeted conditionally activated antibody drug conjugate (ADC), CX-2009 (praluzatamab ravtansine), which delayed tumor growth in two out of three PDX models. Together, these findings credential ALCAM as an immunotherapeutic target in neuroblastoma.

Bitter taste receptors (T2Rs), a family of G-protein coupled receptors, are emerging as potential therapeutic targets in head and neck squamous cell carcinoma (HNSCC). Phendione, a known T2R5 agonist, has not been previously investigated in HNSCC. Here, we show that phendione activates endogenously expressed T2R5 in HNSCC cells and ex vivo tumor samples, inducing sustained calcium responses, reducing cell viability, and promoting apoptosis through a T2R5-dependent mechanism. Analysis of The Cancer Genome Atlas data revealed that high T2R5 expression in HNSCC tumors correlates with improved long-term disease-specific survival, suggesting a potential tumor-suppressive role for T2R5. These findings highlight T2R5 as a promising therapeutic target in HNSCC and support further investigation of phendione or other T2R5 agonists as potential anti-cancer agents.

Recent studies have demonstrated promising outcomes in the treatment of head and neck squamous cell carcinoma (HNSCC) through immune checkpoint cytotoxic T lymphocyte antigen 4 (CTLA4) blockade. However, while the potential of CTLA4 in HNSCC treatment is evident, its underlying mechanism of action remains unclear, leaving room for optimization. Research has revealed that C-C Motif Chemokine ligand (CCL21) possesses the ability to activate T cell responses and enhance the immune response in the tumour microenvironment. CCL21 has demonstrated anti-tumour properties in various cancer types. Combing CCL21 with immune checkpoints inhibitors can amplify the synergistic anti-tumour benefits. This study applied a combination of CTLA4 monoclonal antibody and chemokine CCL21 in the immunotherapy of HNSCC. Furthermore, this optimized therapeutic approach notably enhances the impact on the activation of immune T cells in the tumour microenvironment and elucidates its regulatory influence on the key proteins of the Janus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) signaling pathway. These findings offer an efficacious immunotherapeutic strategy for HNSCC.

Immune checkpoint inhibitors (ICIs) have improved the prognosis of patients with non-small-cell lung cancer (NSCLC), but the cure rate remains low because tolerant persister cancer cells can survive within the tumor during ICI treatment. We have previously reported that plasminogen activator inhibitor-1 (PAI-1) is involved in tolerance acquisition to osimertinib in epidermal growth factor receptor-mutated NSCLC. This study aimed to examine the role of PAI-1 in ICI tolerance and whether PAI-1 may be a therapeutic target to overcome this tolerance. In a mouse subcutaneous tumor model using Lewis lung carcinoma or KLN205 cells, cancer cells surviving within the tumor 7 days after anti-programmed death-1 (aPD-1) antibody treatment were defined as aPD-1 antibody-tolerant persister cells (aPD-1-TPs). PAI-1 and mesenchymal gene expression levels were higher in aPD-1-TPs than in control cells. Immunohistochemical analyses showed higher numbers of tumor-associated macrophages (TAMs), expression of programmed death-ligand 1 (PD-L1) in cancer cells, and degree of angiogenesis. In contrast, the number of tumor-infiltrating lymphocytes (TILs) was lower in aPD-1 antibody-tolerant tumors than in control tumors. Combination treatment with an aPD-1 antibody and the PAI-1 inhibitor TM5614 decreased mesenchymal gene expression, PD-L1 expression, TAM numbers, and angiogenesis and increased TIL counts in tolerant tumors. Furthermore, it resulted in prolonged inhibition of tumor growth. In conclusion, this study underscores the involvement of PAI-1 in the survival of aPD-1-TPs via epithelial-mesenchymal transition and alteration of the tumor microenvironment. Combination treatment with an aPD-1 antibody and TM5614 can be a new therapeutic strategy for NSCLC.

Multiple myeloma is a plasma cell malignancy that is susceptible to drugs targeting protein homeostasis such as thalidomide analogues and proteasome inhibitors. Thalidomide analogues modulate the activity of DDB1/CUL4 E3-ligase complexes to perturb substrate recognition and proteasomal degradation thereof. We hypothesised that the cellular pool of DDB1/CUL4 associated factors (DCAFs) may mediate other essential plasma cell processes and offer new targets for therapeutic intervention. Unbiased genetic screening identified DCAF1 (also known as Vpr-binding protein; VPRBP) as essential for myeloma cell survival with a multidomain structure offering several distinct opportunities for drug development. Utilising B32B3, a previously disclosed DCAF1 kinase inhibitor as a template, we developed a series of analogues with enhanced anti-myeloma potency. As anti-myeloma activity did not associate with dephosphorylation of known DCAF1 kinase substrates, we correlated drug-induced cellular phenotypes with whole-genome CRISPR/Cas9 resistance screening to further define mechanistic activity. These studies identified B32B3 analogues as microtubular destabilising agents with potential DCAF1 kinase independent properties and in vivo efficacy in multiple myeloma and lymphoma.