Tumor Suppressive Effects Research Articles

Clinical and Biologic Correlates of ADORA2A Transcriptomic Expression in Cancer.

ADORA2A (adenosine A2a receptor) and ADORA2B propagate immunoregulatory signals, including restricting both innate and adaptive immunity, though recent data also suggest a tumor suppressor effect in certain settings. We evaluated the RNA expression from 514 tumors in a clinical-grade laboratory; 489 patients with advanced/metastatic disease had clinical outcome correlates. Transcript expression was standardized to internal housekeeping genes and ranked (0-100 scale) relative to 735 specimens from 35 different cancer types. Transcript abundance rank values were defined as "low/moderate" (0-74) or "high" (75-100) percentile RNA expression ranks. Overall, 20.8% of tumors had high ADORA2A (≥75 percentile RNA rank). The greatest proportion of high ADORA2A expressors was found in neuroendocrine and breast cancers and sarcomas, whereas the lowest was found in colorectal and ovarian cancers, albeit with patient-to-patient variability. In multivariable logistic regression analysis, there was a significant positive correlation between high ADORA2A RNA expression and a high expression of the immune checkpoint-related molecules PD-1 (p = 0.015), VISTA (p ≤ 0.001), CD38 (p = 0.031), and CD39 (p ≤ 0.001). In 217 immunotherapy-treated patients, high ADORA2A did not correlate significantly with progression-free (p = 0.51) or overall survival (OS) (p = 0.09) from the initiation of the checkpoint blockade. However, high versus not-high ADORA2A transcript expression correlated with longer OS from the time of advanced/metastatic disease (N = 489 patients; (HR 0.69 (95% CI 0.51-0.95) (p = 0.02)). Therefore, high ADORA2A transcript levels may be a favorable prognostic factor, unrelated to immunotherapy. Importantly, ascertaining co-expression patterns of ADORA2A with PD-1 and VISTA in individual tumors as a basis for the precision co-targeting of ADORA2A and these other checkpoint-related molecules warrants investigation in clinical trials.

Enhancing glioma-specific drug delivery through self-assembly of macrophage membrane and targeted polymer assisted by low-frequency ultrasound irradiation

The blood-brain Barrier (BBB), combined with immune clearance, contributes to the low efficacy of drug delivery and suboptimal treatment outcomes in glioma. Here, we propose a novel approach that combines the self-assembly of mouse bone marrow-derived macrophage membrane with a targeted positive charge polymer (An-PEI), along with low-frequency ultrasound (LFU) irradiation, to achieve efficient and safe therapy for glioma. Our findings demonstrate the efficacy of a charge-induced self-assembly strategy, resulting in a stable co-delivery nanosystem with a high drug loading efficiency of 44.2 %. Moreover, this structure triggers a significant release of temozolomide in the acidic environment of the tumor microenvironment. Additionally, the macrophage membrane coating expresses Spyproteins, which increase the amount of An-BMP-TMZ that can evade the immune system by 40 %, while LFU irradiation treatment facilitates the opening of the BBB, allowing for enormously increased entry of An-BMP-TMZ (approximately 400 %) into the brain. Furthermore, after crossing the BBB, the Angiopep-2 peptide-modified An-BMP-TMZ exhibits the ability to selectively target glioma cells. These advantages result in an obvious tumor inhibition effect in animal experiments and significantly improve the survival of glioma-bearing mice. These results suggest that combining the macrophage membrane-coated drug delivery system with LFU irradiation offers a feasible approach for the accurate, efficient and safe treatment of brain disease.

Design, synthesis, and evaluation of antitumor activity of Mobocertinib derivatives, a third-generation EGFR inhibitor

Mobocertinib, as a structural analog of the third generation TKI Osimertinib, can selectively act on the EGFRex20 mutation. We have structurally modified Mobocertinib to obtain new EGFR inhibitors. In this paper, we chose Mobocertinib as a lead compound for structural modification to investigate the effect of Mobocertinib derivatives on EGFRT790M mutation. We designed and synthesized 63 Mobocertinib derivatives by structural modification using the structural similarity strategy and the bioelectronic isoarrangement principle. Then, we evaluated the in vitro antitumor activity of the 63 Mobocertinib derivatives and found that the IC50 of compound H-13 against EGFRL858R/T790M mutated H1975 cells was 3.91 μM, and in further kinase activity evaluation, the IC50 of H-13 against EGFRL858R/T790M kinase was 395.2 nM. In addition, the preferred compound H-13 was able to promote apoptosis of H1975 tumor cells and block the proliferation of H1975 cells in the G0/G1 phase; meanwhile, it was able to significantly inhibit the migratory ability of H1975 tumor cells and inhibit the growth of H1975 cells in a time-concentration-dependent manner. In the in vivo anti-tumor activity study, the preferred compound H-13 had no obvious toxicity to normal mice, and the tumor inhibition effect on H1975 cell-loaded nude mice was close to that of Mobocertinib. Finally, molecular dynamics simulations showed that the binding energy between compound H-13 and 3IKA protein was calculated to be −162.417 ± 14.559 kJ/mol. In summary, the preferred compound H-13 can be a potential third-generation EGFR inhibitor.

Nanoassembly-Mediated Exendin-4 Derivatives to Decrease Renal Retention.

An Exendin-4 analogue that was conjugated with 68Ga exhibited an excellent diagnostic effect on insulinoma in clinical practice. On account of its low molecular weight and short hydration radius, 68Ga-Exendin-4 showed high accumulation in kidney tissues. Nanoparticle-mediated strategies have attracted much attention due to polyvalent properties and the size amplification effect. In this study, Exendin-4 derivatives of radionuclide nanodevices were developed and evaluated. The Exendin-4 derivatives consisting of a ternary block recombinant protein were purified by an inverse transition cycle (ITC) and allowed to self-assemble into a nanodevice under physiological conditions. Our results showed that the nanoassemblies of Exendin-4 derivatives formed homogeneous spherical nanoparticles, exhibited outstanding affinity for insulinoma cells, and could be deposited in insulinoma tissues in vivo. The nanoassembly-mediated Exendin-4 derivatives showed fivefold reduced renal retention and exhibited an outstanding tumor-suppression effect.

Hydralazine loaded nanodroplets combined with ultrasound-targeted microbubble destruction to induce pyroptosis for tumor treatment

Pyroptosis, a novel type of programmed cell death (PCD), which provides a feasible therapeutic option for the treatment of tumors. However, due to the hypermethylation of the promoter, the critical protein Gasdermin E (GSDME) is lacking in the majority of cancer cells, which cannot start the pyroptosis process and leads to dissatisfactory therapeutic effects. Additionally, the quick clearance, systemic side effects, and low concentration at the tumor site of conventional pyroptosis reagents restrict their use in clinical cancer therapy. Here, we described a combination therapy that induces tumor cell pyroptosis via the use of ultrasound-targeted microbubble destruction (UTMD) in combination with DNA demethylation. The combined application of UTMD and hydralazine-loaded nanodroplets (HYD-NDs) can lead to the rapid release of HYD (a demethylation drug), which can cause the up-regulation of GSDME expression, and produce reactive oxygen species (ROS) by UTMD to cleave up-regulated GSDME, thereby inducing pyroptosis. HYD-NDs combined with ultrasound (US) group had the strongest tumor inhibition effect, and the tumor inhibition rate was 87.15% (HYD-NDs group: 51.41 ± 3.61%, NDs + US group: 32.73%±7.72%), indicating that the strategy had a more significant synergistic anti-tumor effect. In addition, as a new drug delivery carrier, HYD-NDs have great biosafety, tumor targeting, and ultrasound imaging performance. According to the results, the combined therapy reasonably regulated the process of tumor cell pyroptosis, which offered a new strategy for optimizing the therapy of GSDME-silenced solid tumors.

The histone lysine acetyltransferase KAT2B inhibits cholangiocarcinoma growth: evidence for interaction with SP1 to regulate NF2-YAP signaling

BackgroundCholangiocarcinoma (CCA) is a highly malignant cancer of the biliary tract with poor prognosis. Further mechanistic insights into the molecular mechanisms of CCA are needed to develop more effective target therapy.MethodsThe expression of the histone lysine acetyltransferase KAT2B in human CCA was analyzed in human CCA tissues. CCA xenograft was developed by inoculation of human CCA cells with or without KAT2B overexpression into SCID mice. Western blotting, ChIP-qPCR, qRT-PCR, protein immunoprecipitation, GST pull-down and RNA-seq were performed to delineate KAT2B mechanisms of action in CCA.ResultsWe identified KAT2B as a frequently downregulated histone acetyltransferase in human CCA. Downregulation of KAT2B was significantly associated with CCA disease progression and poor prognosis of CCA patients. The reduction of KAT2B expression in human CCA was attributed to gene copy number loss. In experimental systems, we demonstrated that overexpression of KAT2B suppressed CCA cell proliferation and colony formation in vitro and inhibits CCA growth in mice. Mechanistically, forced overexpression of KAT2B enhanced the expression of the tumor suppressor gene NF2, which is independent of its histone acetyltransferase activity. We showed that KAT2B was recruited to the promoter region of the NF2 gene via interaction with the transcription factor SP1, which led to enhanced transcription of the NF2 gene. KAT2B-induced NF2 resulted in subsequent inhibition of YAP activity, as reflected by reduced nuclear accumulation of oncogenic YAP and inhibition of YAP downstream genes. Depletion of NF2 was able to reverse KAT2B-induced reduction of nuclear YAP and subvert KAT2B-induced inhibition of CCA cell growth.ConclusionsThis study provides the first evidence for an important tumor inhibitory effect of KAT2B in CCA through regulation of NF2-YAP signaling and suggests that this signaling cascade may be therapeutically targeted for CCA treatment.

Polymeric micellar nanoparticles for effective CRISPR/Cas9 genome editing in cancer

The clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9) gene editing has attracted extensive attentions in various fields, however, its clinical application is hindered by the lack of effective and safe delivery system. Herein, we reported a cationic micelle nanoparticle composed of cholesterol-modified branched small molecular PEI (PEI-CHO) and biodegradable PEG-b-polycarbonate block copolymer (PEG-PC), denoted as PEG-PC/PEI-CHO/pCas9, for the CRISPR/Cas9 delivery to realize genomic editing in cancer. Specifically, PEI-CHO condensed pCas9 into nanocomplexes, which were further encapsulated into PEG-PC nanoparticles (PEG-PC/PEI-CHO/pCas9). PEG-PC/PEI-CHO/pCas9 had a PEG shell, protecting DNA from degradation by nucleases. Enhanced cellular uptake of PEG-PC/PEI-CHO/pCas9 nanoparticles was observed as compared to that mediated by Lipo2k/pCas9 nanoparticles, thus leading to significantly elevated transfection efficiency after escaping from endosomes via the proton sponge effect of PEI. In addition, the presence of PEG shell greatly improved biocompatibility, and significantly enhanced the in vivo tumor retention of pCas9 compared to PEI-CHO/pCas9. Notably, apparent downregulation of GFP expression could be achieved both in vitro and in vivo by using PEG-PC/PEI-CHO/pCas9-sgGFP nanoparticles. Furthermore, PEG-PC/PEI-CHO/pCas9-sgMcl1 induced effective apoptosis and tumor suppression in a HeLa tumor xenograft mouse model by downregulating Mcl1 expression. This work may provide an alternative paradigm for the efficient and safe genome editing in cancer.

Trimethyl chitosan–cysteine-based nanoparticles as an effective delivery system for portulacerebroside A in the management of hepatocellular carcinoma cells in vitro and in vivo

Portulacerebroside A (PCA), a cerebroside compound extracted from Portulaca oleracea L., has been shown to suppress hepatocellular carcinoma (HCC) cells. This study aims to investigate the effectiveness of trimethyl chitosan–cysteine (TMC-Cys) nanocarrier in delivering PCA for HCC management and to elucidate the molecular mechanisms behind PCA’s function. TMC-Cys nanocarriers notably augmented PCA’s function, diminishing the proliferation, migration, and invasiveness of HCC cells in vitro, reducing hepatocellular tumorigenesis in immunocompetent mice, and impeding metastasis of xenograft tumours in nude mice. Comprehensive bioinformatics analyses, incorporating Super-PRED systems alongside pathway enrichment analysis, pinpointed toll-like receptor 4 (TLR4) and epidermal growth factor receptor (EGFR) as two promising targets of PCA, enriched in immune checkpoint pathway. PCA/nanocarrier (PCA) reduced levels of TLR4 and EGFR and their downstream proteins, including programmed cell death ligand 1, thereby increasing populations and activity of T cells co-cultured with HCC cells in vitro or in primary HCC tumours in mice. However, these effects were counteracted by additional artificial activation of TLR4 and EGFR. In conclusion, this study provides novel evidence of PCA’s function in immunomodulation in addition to its direct tumour suppressive effect. TMC-Cys nanocarriers significantly enhance PCA efficacy, indicating promising application as a drug delivery system.

GDF11 inhibits the malignant progression of hepatocellular carcinoma via regulation of the mTORC1‑autophagy axis.

Hepatocellular carcinoma (HCC) is a common malignant tumor, which is associated with a poor prognosis and high mortality rate. It is well known that growth differentiation factor 11 (GDF11) acts as a tumor suppressor in various types of cancer, including HCC. The present study aimed to determine the tumor-suppressive properties of GDF11 in HCC and to assess the intrinsic mechanisms. In the present study, the human hepatoma cell line Huh-7 was transfected with the GDF11 overexpression plasmid (Oe-GDF11) for gain-of-function experiments to investigate the effects of GDF11 on the biological behaviors of HCC cells, including proliferation, colony formation, apoptosis, cell cycle arrest, migration, invasion, epithelial-mesenchymal transition (EMT) and angiogenesis. The proliferation, colony formation, apoptosis, cell cycle, migration, invasion and angiogenesis of HCC cells were assessed by CCK-8, EdU staining, colony formation, flow cytometry, wound healing, Transwell and tube formation assays, respectively. Apoptosis-, cell cycle-, EMT-related key factors were also determined by western blot assay. Furthermore, Oe-GDF11-transfected Huh-7 cells were treated with the mammalian target of rapamycin (mTOR) activator MHY1485 for rescue experiments to explore whether GDF11 could exert antitumor effects against HCC via mediating the mTOR complex 1 (mTORC1)-autophagy axis. In the present study, GDF11 was verified to be lowly expressed in HCC cells. Overexpression of GDF11 inhibited the proliferation, colony formation, migration, invasion, EMT and angiogenesis of HCC cells, and facilitated the apoptosis and cell cycle arrest of HCC cells. Additionally, it was verified that overexpression of GDF11 inactivated the mTORC1 signaling pathway to enhance autophagy in HCC cells. Treatment with the mTOR activator MHY1485 partially reversed the tumor-suppressive effects of GDF11 overexpression on HCC. In conclusion, GDF11 may exert tumor-suppressive properties in HCC cells through inactivating the mTORC1 signaling pathway to strengthen autophagy.

Characterization and application of targeted MnO2/CS@ALA-MTX nano-radiosensitizers for boosting X-ray radiotherapy of brain tumors

The current study aimed to investigate the potential of methotrexate (MTX) functionalized, 5-aminolevulinic acid (5-ALA)-modified, chitosan-coated manganese dioxide (MnO2/CS) nanoparticles (NPs) as a targeted radiosensitizer for cancer therapy. The novelty of the current study lies in the development of the MnO2/CS@5-ALA-MTX NPs as a novel formulation with high encapsulation capacity, site specificity, and biosafety for targeted drug delivery. The study also emphasizes comprehensive in-vitro tests to understand the cell death mechanisms after radiosensitization. The effects of MnO2/CS@5-ALA-MTX NPs on U87MG cell lines treated with radiation were examined in-vitro and in-vivo. Mitochondrial function and reactive oxygen species (ROS) production were evaluated under normoxia and hypoxia conditions. The combination of MTX and 5-ALA provided tumor-targeting ability, while the CS coating prolonged the circulation time of the nano-system. The synthesized MnO2/CS@5-ALA-MTX NPs had an average size of 70 ± 9 nm, a Zeta potential of −6 ± 2 mV, and a polydispersity of 0.240. The loading efficiency and release profile of the drug delivery system were assessed and demonstrated its capacity for drug delivery. The MTT assay on U87MG cells revealed that MnO2/CS@5-ALA-MTX NPs reduced cell viability compared to MTX alone. Both in-vitro and in-vivo studies demonstrated tumor-enhanced radiosensitization using MTX functionalized MnO2/CS NPs. The mice receiving MnO2/CS@5-ALA-MTX NPs and subsequent radiation exposure exhibited significant tumor inhibition and increased survival ratios. Notably, tumor-bearing mice treated with MnO2/CS@5-ALA-MTX NPs and X-ray irradiation demonstrated more effective tumor rejection compared to the groups treated with X-ray alone or NPs alone. In conclusion, the results highlight the potential of MnO2/CS@5-ALA-MTX NPs as a targeted radiosensitizer for cancer therapy. The NPs exhibited promising tumor-inhibiting effects and enhanced radiosensitization both in-vitro and in-vivo, suggesting their potential as a valuable approach for cancer treatment in the future.

Optical controlled and nuclear targeted CECR2 competitor to downregulate CSF-1 for metastatic breast cancer immunotherapy

The crosstalk between breast cancer cells and tumor associated macrophages (TAMs) greatly contributes to tumor progression and immunosuppression. In this work, cat eye syndrome chromosome region candidate 2 (CECR2) is identified to overexpress in breast cancer patients, which can recognize v-rel avian reticuloendotheliosis viral oncogene homolog A (RelA) and activate nuclear factor κB (NF-κB) to release colony stimulating factor-1 (CSF-1). Pharmacological inhibition of CECR2 by the bromodomain competitor (Bromosporine, Bro) can downregulate CSF-1 to inhibit M2 type TAMs. To amplify the immunotherapeutic effect, a chimeric peptide-based and optical controlled CECR2 competitor (designated as N-PB) is constructed to enhance the nuclear targeted delivery of Bro and initiate an immunogenic cell death (ICD). In vivo results indicate a favorable breast cancer targeting ability and primary tumor suppression effect of N-PB under optical irradiation. Importantly, N-PB downregulates CSF-1 by competitive inhibition of CECR2 and NF-κB(RelA) interactions, thus inhibiting immunosuppressive M2-like TAMs while improving the antitumorigenic M1-like phenotype. Ultimately, the systemic anti-tumor immunity is activated to suppress the metastatic breast cancer in an optical controlled manner. This study provides a promising therapeutic target and reliable strategy for metastatic breast cancer treatment by interrupting immunosuppressive crosstalk between tumor cells and macrophages.

Macrophage membrane-camouflaged pH-sensitive nanoparticles for targeted therapy of oral squamous cell carcinoma

BackgroundOral cancer is the most common malignant tumor of the head and neck, and 90% of cases are oral squamous cell carcinoma (OSCC). Chemotherapy is an important component of comprehensive treatment for OSCC. However, the clinical treatment effect of chemotherapy drugs, such as doxorubicin (DOX), is limited due to the lack of tumor targeting and rapid clearance by the immune system. Thus, based on the tumor-targeting and immune evasion abilities of macrophages, macrophage membrane-encapsulated poly(methyl vinyl ether alt maleic anhydride)-phenylboronic acid-doxorubicin nanoparticles (MM@PMVEMA-PBA-DOX NPs), briefly as MM@DOX NPs, were designed to target OSCC. The boronate ester bonds between PBA and DOX responded to the low pH value in the tumor microenvironment, selectively releasing the loaded DOX.ResultsThe results showed that MM@DOX NPs exhibited uniform particle size and typical core-shell structure. As the pH decreased from 7.4 to 5.5, drug release increased from 14 to 21%. The in vitro targeting ability, immune evasion ability, and cytotoxicity of MM@DOX NPs were verified in HN6 and SCC15 cell lines. Compared to free DOX, flow cytometry and fluorescence images demonstrated higher uptake of MM@DOX NPs by tumor cells and lower uptake by macrophages. Cell toxicity and live/dead staining experiments showed that MM@DOX NPs exhibited stronger in vitro antitumor effects than free DOX. The targeting and therapeutic effects were further confirmed in vivo. Based on in vivo biodistribution of the nanoparticles, the accumulation of MM@DOX NPs at the tumor site was increased. The pharmacokinetic results demonstrated a longer half-life of 9.26 h for MM@DOX NPs compared to 1.94 h for free DOX. Moreover, MM@DOX NPs exhibited stronger tumor suppression effects in HN6 tumor-bearing mice and good biocompatibility.ConclusionsTherefore, MM@DOX NPs is a safe and efficient therapeutic platform for OSCC.

An oncolytic virus delivering tumor-irrelevant bystander T cell epitopes induces anti-tumor immunity and potentiates cancer immunotherapy

Tumor-specific T cells are crucial in anti-tumor immunity and act as targets for cancer immunotherapies. However, these cells are numerically scarce and functionally exhausted in the tumor microenvironment (TME), leading to inefficacious immunotherapies in most patients with cancer. By contrast, emerging evidence suggested that tumor-irrelevant bystander T (TBYS) cells are abundant and preserve functional memory properties in the TME. To leverage TBYS cells in the TME to eliminate tumor cells, we engineered oncolytic virus (OV) encoding TBYS epitopes (OV-BYTE) to redirect the antigen specificity of tumor cells to pre-existing TBYS cells, leading to effective tumor inhibition in multiple preclinical models. Mechanistically, OV-BYTE induced epitope spreading of tumor antigens to elicit more diverse tumor-specific T cell responses. Remarkably, the OV-BYTE strategy targeting human severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cell memory efficiently inhibited tumor progression in a human tumor cell-derived xenograft model, providing important insights into the improvement of cancer immunotherapies in a large population with a history of SARS-CoV-2 infection or coronavirus disease 2019 (COVID-19) vaccination.

CircSNX6 promotes proliferation, metastasis, and angiogenesis in hepatocellular carcinoma via miR-383-5p/VEGFA signaling pathway

The role of circular RNA (circRNAs) in hepatocellular carcinoma (HCC) has been extensively studied. Previous research has highlighted the regulatory role of circSNX6 in HCC cells and tissues. However, the precise mechanism underlying HCC progression still requires comprehensive investigation. The study initially utilized quantitative reverse transcription-polymerase chain reaction (qRT-PCR) to assess circSNX6 expression levels in HCC cell lines and tissues. Subsequently, the stability of circRNA was evaluated through Ribonuclease R and actinomycin D treatment assays. The impact of circSNX6 knockdown on proliferation, migration, invasion, and angiogenesis abilities was determined using various assays including colony formation, Transwell culture system, tube formation assay, and cell counting kit (CCK)-8 assays. Additionally, RNA immunoprecipitation chip and dual-luciferase reporter assays were employed to investigate the interactions between circSNX6 and miR-383-5p. Finally, an HCC xenograft tumor model in mice was established to assess the in vivo expression of circSNX6 and its functional role in HCC. Our findings revealed an elevated circSNX6 expression in HCC tissues, which was correlated with poor patient prognosis. Knockdown of circSNX6 suppressed HCC cell growth, invasion, metastasis, and angiogenesis. The downregulation of miR-383-5p, a target of circSNX6, significantly attenuated the tumor-suppressive effects induced by circSNX6 knockdown. Moreover, circSNX6 was found to modulate VEGFA expression by targeting miR-383-5p. The inhibition of HCC cell proliferation by miR-383-5p could be partially reversed by overexpressing VEGFA. Silencing circSNX6 also suppressed tumor formation and the metastasis of HCC cells in a mouse model. In summary, our findings suggest that circSNX6 promotes cell proliferation, metastasis, and angiogenesis in HCC by regulating the miR-383-5p/VEGFA pathway.

The HSP90AB1-mediated upregulation of IDO1 can promote the progression of colorectal cancer

Abstract Objectives Colorectal cancer (CRC) is a global challenge, and heat shock protein 90 (HSP90) is identified as a key driver in cancer progression. However, the tumor-promoting mechanism of HSP90 in CRC, particularly HSP90AB1, remains unclear. This study aims to explore and analyze the oncogenic mechanism of HSP90AB1 in CRC and identify potential therapeutic targets. Materials and methods HSP90AB1 expression underwent analysis in CRC cell lines and tissues at mRNA and protein levels. Through the use of shRNA, targeted suppression of HSP90AB1 was achieved in CRC cell lines, enabling analysis of its influence on cell proliferation, invasion, apoptosis, and cell cycle progression. Subsequent investigation focused on elucidating the regulatory relationship between HSP90AB1 and IDO1, employing a combination of bioinformatics approaches and in vitro/vivo experiments. These efforts confirmed IDO1 as a downstream target of HSP90AB1 and provided insight into its role in driving CRC progression. Results HSP90AB1 exhibits overexpression in both CRC cell lines and tumor tissues (p<0.05). Its downregulation impedes cell proliferation and invasion (p<0.01), promotes apoptosis and cell cycle arrest (p<0.05). Investigation reveals that decreased HSP90AB1 leads to the inhibition of IDO1 (p<0.01), suggesting that IDO1 regulation plays a crucial role in mediating the pro-tumorigenic effects of HSP90AB1. In vivo experiments confirm the substantial reduction in tumor growth upon HSP90AB1 knockdown in xenograft models (p<0.01). However, this tumor-suppressive effect is reversed upon IDO1 overexpression (p<0.01), highlighting IDO1 as a downstream target of HSP90AB1 in CRC progression. Conclusions HSP90AB1 exerts a regulatory role in the progression of CRC by upregulating IDO1.

Advancing colorectal cancer therapy with biosynthesized cobalt oxide nanoparticles: a study on their antioxidant, antibacterial, and anticancer efficacy

BackgroundColorectal cancer (CRC) ranks as the third most common cancer globally and the second leading cause of cancer-related mortality. Traditional chemotherapy, while effective, often results in significant side effects, highlighting the need for more efficient cancer therapies. Recent advancements in nanotechnology have led to the development of strategies that aim to minimize toxicity to normal cells by more precise targeting of cancer cells. In this context, cobalt oxide nanoparticles (Co3O4 NPs) have shown promising anticancer potential. Our study focuses on evaluating the antioxidant, antibacterial, and anticancer properties of Co3O4 NPs synthesized using Vibrio sp. VLC, a bioluminescent bacterium.ResultsXRD and FTIR analyses confirmed the successful synthesis of Co3O4 NPs, which displayed spherical morphology with an average diameter of 60 nm. The nanoparticles demonstrated significant antioxidant and antibacterial activities. The MTT assay indicated that the NPs caused dose- and time-dependent toxicity against CT26 cells, while exhibiting relatively lower toxicity towards normal cells. In vivo experiments further confirmed the significant tumor suppressive effects in BALB/c mice, with minimal side effects on the liver, spleen, and kidney tissues compared to the widespread toxicity of cisplatin.ConclusionThis study verifies the successful synthesis of Co3O4 NPs and their potent antioxidant, antibacterial, and anticancer activities. The biosynthesized Co3O4 NPs represent a promising targeted method for CRC therapy. However, further research is needed to elucidate their mechanism of action and also their application in the clinical phase.Graphical

Abstract LB165: GFH547: An orally bioavailable, cyclophilin A-hijacking panRAS(on) inhibitor with broad spectrum anti-tumor activities

Abstract KRAS has recently become druggable with the approval of two KRAS G12C inhibitors - sotorasib and adagrasib. However, current SIIP-based KRAS inhibitors preferentially target the inactive, GDP-bound KRAS and thus are susceptible to adaptive resistance due to MAPK pathway reactivation. Furthermore, RTK pathway alterations frequently emerge to cause acquired resistance. These drawbacks limit the rate and duration of anti-tumor response. Developing more robust small molecule RAS (on) inhibitors that target active, GTP-bound RAS proteins is a promising new approach to enhance clinical benefits. Here we report preclinical characterization of a novel RAS (on) inhibitor - GFH547, designed to treat cancers carrying multiple RAS mutations. In biochemical assays, GFH547 disrupted the binding of GMPPNP-bound G12V, G12D or wild type KRAS to RAF1 in a CypA-dependent manner, as the inhibitory effect was significantly abolished in the absence of CypA. GFH547 suppressed phosphor-ERK1/2 (p-ERK) levels in KRAS G12V- and G12D-mutated cells with IC50s < 1 nM, and demonstrated potent tumor-suppressive effect in 29 cancer cell lines carrying diverse KRAS (G12A, G12C, G12V, G12R, G12S or G13D), NRAS (G12D or Q61L) or HRAS (Q61H) mutations, with IC50s of 0.04-1.9 nM. In addition, GFH547 was also cytotoxic in 9 cancer cell lines carrying EGFR or FGFR2/3 amplification, mutation or fusion, with IC50s of 0.12-198 nM. Conversely, GFH547 was inactive against 4 BRAF V600E-mutated, RAS-independent cancer cell lines. In KRAS-mutated xenograft models, oral administration of GFH547 elicited rapid and potent inhibition of intratumoral p-ERK levels, and led to tumor regression at dose levels as low as 1 mg/kg QD. In contrast to sotorasib and adagrasib, GFH547 was not susceptible to RTK-reactivation following EGF stimulation, and remained effective against cell lines carrying KRAS mutations that confer acquired resistance to SIIP-based KRAS inhibitors. At 10 μM, GFH547 showed no off-target activity in 72-kinase selectivity and SafetyScreen44 panels. GFH547 has a bioavailability of 76% and was well tolerated in mice, with an estimated therapeutic index >20. Taken together, by hijacking CypA to block oncogenic RAS proteins broadly in their active forms, GFH547 represents a new generation of RAS inhibitors that are superior to the mainstream SIIP-based KRAS inhibitors in overcoming adaptive and acquired resistance. The compound demonstrated strong therapeutic activities in tumors with activating RAS and RTK mutations/alterations. Based on these promising results, we are advancing a CypA-binding panRAS(on) inhibitor into the clinic as targeted therapy for cancers addicted to RAS pathways. Citation Format: Feng Yan, Jichen Zhao, Tao Liang, Tao Jiang, Chonglan Lin, Ling Peng, Kai Ma, Huabin Yang, Wan He, Zhen Li, Leitao Zhang, Xiaoming Xu, Yanhui Zhao, Xiaohui Zhang, Yonghong Ni, Qiang Liu, Jinting Gao, Fubo Xie, Xueyan Gao, Xiaoling Lan, Li Wang, Jingyang Zhang, Hongcan Ren, Dong Liu, Siyuan Le, Fusheng Zhou, Jiong Lan, Qiang Lu. GFH547: An orally bioavailable, cyclophilin A-hijacking panRAS(on) inhibitor with broad spectrum anti-tumor activities [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB165.

RBM10 C761Y mutation induced oncogenic ASPM isoforms and regulated β-catenin signaling in cholangiocarcinoma

BackgroundCholangiocarcinoma (CCA) comprises a heterogeneous group of biliary tract cancer. Our previous CCA mutation pattern study focused on genes in the post-transcription modification process, among which the alternative splicing factor RBM10 captured our attention. However, the roles of RBM10 wild type and mutations in CCA remain unclear.MethodsRBM10 mutation spectrum in CCA was clarified using our initial data and other CCA genomic datasets from domestic and international sources. Real-time PCR and tissue microarray were used to detect RBM10 clinical association. Function assays were conducted to investigate the effects of RBM10 wild type and mutations on CCA. RNA sequencing was to investigate the changes in alternative splicing events in the mutation group compared to the wild-type group. Minigene splicing reporter and interaction assays were performed to elucidate the mechanism of mutation influence on alternative splicing events.ResultsRBM10 mutations were more common in Chinese CCA populations and exhibited more protein truncation variants. RBM10 exerted a tumor suppressive effect in CCA and correlated with favorable prognosis of CCA patients. The overexpression of wild-type RBM10 enhanced the ASPM exon18 exon skipping event interacting with SRSF2. The C761Y mutation in the C2H2-type zinc finger domain impaired its interaction with SRSF2, resulting in a loss-of-function mutation. Elevated ASPM203 stabilized DVL2 and enhanced β-catenin signaling, which promoted CCA progression.ConclusionsOur results showed that RBM10C761Y-modulated ASPM203 promoted CCA progression in a Wnt/β-catenin signaling-dependent manner. This study may enhance the understanding of the regulatory mechanisms that link mutation-altering splicing variants to CCA.

Facile construction of gold- and BODIPY-coordinated liposomal nanocomplexes for enhanced photothermal therapy of cancer

Photothermal therapy (PTT) has attracted extensive attention in cancer treatment because of its advantages of non-invasive and few side effects. Gold nanoparticles and boron-fluorine-dipyrrole (BODIPY) dye have been used as photothermal agents (PTAs), but they have problems such as easy aggregation, poor water solubility and low photothermal conversion efficiency. In this work, we used conventional liposomes for in situ generation of small gold nanoparticles and sequentially loading BODIPY to overcome the drawbacks of the two PTAs and simultaneously realize enhanced PTT. Gold- and BODIPY-coordinated liposomal nanocomplexes LAB with small gold nanoparticles adsorbed on the surface and BODIPY entrapped inside showed uniform size of about 100 nm with good stability. LAB demonstrated laser-responsive drug release property, good cellular uptake efficiency and tumor accumulation ability. After laser irradiation, LAB can exert enhanced PTT in cancer cell lines by reducing mitochondrial membrane potential and increase intracellular reactive oxygen species level to promote cell apoptosis. In tumor-bearing mice, LAB showed fantastic tumor inhibition effect with good biosafety. This work provides a convenient method to develop PTA combinations for enhanced PTT, which could lay the foundation for the green construction of new PTAs for PTT by employing clinically used formulations and PTAs.

Pan-Cancer Analysis Identifies BCLAF1 as a Potential Biomarker for Renal Cell Carcinoma.

B-cell lymphoma-2-associated transcription factor 1 (BCLAF1) is a versatile protein involved in the regulation of gene transcription and post-transcriptional processing. Although BCLAF1 exerts a broad tumor suppressor effect or tumor promoter effect in many cancer types, the specific roles concerning its expression levels, and its impact on tumorigenesis in Renal cell carcinoma (RCC) remain unclear. Here, we utilized the Cancer Genome Atlas (TCGA) and Genotype Tissue Expression (GTEx) datasets alongside R software and online tools to unravel the specific roles of BCLAF1 in 33 cancer types, including its expression levels, tumor immune and molecular subtypes, and its correlation with prognosis, diagnosis, DNA methylation, and immune microenvironment. Additionally, we carried out cell biology experiments to independently investigate the expression of BCLAF1 in RCC and its effects on tumor progression. BCLAF1 was differentially expressed in tumor tissues compared to normal tissues across various cancer types and was also differentially expressed in different immune and molecular subtypes. In RCC, patients with high BCLAF1 expression had a better prognosis and BCLAF1 was tightly correlated with the stage, gender, and histological grade of patients. Furthermore, BCLAF1 had higher DNA methylation levels and higher immune infiltration levels in tumor tissues. Additionally, cell functional experiments confirmed the low expression of BCLAF1 in RCC and that BCLAF1 significantly inhibited the proliferation, migration, and invasion, while inducing apoptosis and cell cycle arrest in RCC cells in vitro. Our study under-scored the potential of BCLAF1 as an important actor in tumorigenesis, especially concerning RCC where it may serve as an effective prognostic marker.