Proliferation Inhibitory Effect Research Articles

Comparative Analysis of Acetylated Flavonoids’ Chemopreventive Effects in Different Cancer Cell Lines

Flavonoids, a class of natural compounds with anticancer activity, exhibit varying biological activities and potencies based on their structural differences. Acylation, including acetylation of flavonoids, generally increases their structural diversity, which is closely related to the diversity of bioactivity within this group of compounds. However, it remains largely unknown how acetylation affects the bioactivity of many flavonoids. Based on our previous findings that O-acetylation enhances quercetin’s bioactivity against various cancer cells, we synthesized 12 acetylated flavonoids, including seven novel compounds, to investigate their anticancer activities in the MDA-MB-231, HCT-116, and HepG2 cell lines. Our results showed that acetylation notably enhanced the cell proliferation inhibitory effect of quercetin and kaempferol across all cancer cell lines tested. Interestingly, while the 5,7,4′-O-triacetate apigenin (3Ac-A) did not show an enhanced the effect of inhibition of cell proliferation through acetylation, it exhibited significantly strong anti-migration activity in MDA-MB-231 cells. In contrast, the 7,4′-O-diacetate apigenin (2Ac-Q), which lacks acetylation at the 5-position hydroxy group, showed enhanced cell proliferation inhibitory effect but had weaker anti-migration effects compared to 3Ac-A. These results indicated that acetylated flavonoids, especially quercetin, kaempferol, and apigenin derivatives, are promising for anticancer applications, with 3Ac-A potentially having unique anti-migration pathways independent of apoptosis induction. This study highlights the potential application of flavonoids in novel chemopreventive strategies for their anti-cancer activity.

T cell receptor-directed antibody-drug conjugates for the treatment of T cell-derived cancers

T cell-derived cancers are hallmarked by heterogeneity, aggressiveness, and poor clinical outcomes. Available targeted therapies are severely limited due to a lack of target antigens that allow discrimination of malignant from healthy T cells. Here we report a novel approach for the treatment of T cell diseases based on targeting the clonally rearranged T cell receptor displayed by the cancerous T cell population. As a proof of concept, we identified an antibody with unique specificity towards a distinct TCR and developed antibody-drug conjugates, precisely recognizing and eliminating target T cells while preserving overall T cell repertoire integrity and cellular immunity. Our anti-TCR antibody-drug conjugates demonstrated effective receptor-mediated cell internalization, associated with induction of cancer cell death with strong signs of apoptosis. Furthermore, cell proliferation-inhibiting bystander effects observed on target-negative cells may contribute to the molecules’ anti-tumor properties precluding potential tumor escape mechanisms. To our knowledge, this represents the first anti-TCR antibody-drug conjugate designed as custom-tailored immunotherapy for T cell-driven pathologies.

Pristimerin enhances cisplatin-induced apoptosis in nasopharyngeal carcinoma cells via ROS-mediated deactivation of the PI3K/AKT signaling pathway

To explore the effect of pristimerin combined with cisplatin on proliferation and apoptosis of nasopharyngeal carcinoma cells. CCK-8 assay was used to examine the survival rate of HNE-1 and CNE-2Z cells following treatment for 24 h with different concentrations of pristimerin, cisplatin or their combination. The changes in colony formation ability, apoptosis, and intracellular reactive oxygen species (ROS) levels of the treated cells were analyzed using colony formation assay and flow cytometry. Western blotting was performed to detect the changes in protein expressions in the cells. The effects of pre-treatment with NAC on proliferation, apoptosis, and PI3K/AKT signaling pathway were observed in pristimerin- and/or cisplatin-treated cells. Both pristimerin and cisplatin significantly lowered the survival rate of HNE-1 and CNE-2Z cells (P < 0.05). Compared with pristimerin or cisplatin alone, their combination more strongly inhibited survival and colony formation ability of the cells, increased cell apoptosis rate and intracellular ROS levels, upregulated the protein expressions of Bax, cleaved caspase-3, and cleaved PARP, and downregulated the protein expressions of Bcl-2, Mcl-1, PARP and p-PI3K and p-AKT (P < 0.05). NAC pretreatment significantly attenuated proliferation inhibition and apoptosis-promoting effects of pristimerin combined with cisplatin, and partially restored the downregulated protein expressions of p-PI3K and p-AKT in HNE-1 and CNE-2Z cells with the combined treatment (P < 0.05). Pristimerin can enhance cisplatin-induced proliferation inhibition and apoptosis in nasopharyngeal carcinoma cells, the mechanism of which may involve ROS-mediated deactivation of the PI3K/AKT signaling pathway.

Preliminary study on the mechanism by which exosomes derived from human exfoliated deciduous teeth improve the proliferation and osteogenic inhibitory effect of glucocorticoid-induced BMSCs

BackgroundSteroid-induced osteonecrosis of the femoral head (SONFH) is a disease characterized by a collapsed femoral head caused by the overuse of glucocorticoids. Dysfunction of bone marrow mesenchymal stem cells (BMSCs) is an important pathological feature of SONFH. In this study, we investigated whether exosomes from SHEDs (stem cells from human exfoliated deciduous teeth) have a therapeutic effect on glucocorticoid-induced inhibition of proliferation and osteogenesis in BMSCs, and elucidated the underlying mechanisms involved. MethodsPrimary dental pulp cells were isolated and cultured from human deciduous tooth pulp, SHEDs were isolated and purified by the limiting dilution method and exosomes were isolated from the supernatants of SHEDs by ultracentrifugation. The cell surface markers CD31, CD34, CD45, CD73, CD90 and CD105 were detected by flow cytometry. A Cell-Counting-Kit-8 assay was used to detect cell activity. ALP and Alizarin Red staining were used to identify osteogenic differentiation ability, and exosomes were identified using transmission electron microscopy, NanoFCM and Western blotting. PKH67 fluorescence was used to track the uptake of exosomes by BMSCs. Transcriptome analysis combined with quantitative real-time PCR was used to explore the underlying mechanism involved. ResultsExosomes secreted by SHEDs can be endocytosed by BMSCs, and can partially reverse the inhibitory effects of glucocorticoids on the viability and osteogenic differentiation of BMSCs. Transcriptome sequencing analysis revealed that the differentially expressed mRNAs regulated by SHED-derived exosomes were enriched mainly in signaling pathways such as the apoptosis pathway, the PI3K-Akt signaling pathway, the Hippo signaling pathway and the p53 signaling pathway. qPCR showed that SHED-derived exosomes reversed the dexamethasone-induced upregulation of HGF and ITGB8 expression and the inhibition of EFNA1 expression, but further increased the dexamethasone-induced downregulation of IL7 expression. In conclusion, SHED-derived exosomes partially reversed the inhibitory effects of glucocorticoids on BMSC proliferation and osteogenesis by inhibiting the expression of HGF, ITGB8 and IL7, and upregulating the expression of EFNA1.

Genistein-Chitosan Derivative Nanoparticles for Targeting and Enhancing the Anti-Breast Cancer Effect of Tamoxifen In Vitro

Tamoxifen (TAM) is a classical anti-estrogenic drug that antagonizes estrogen by competitively binding to estrogen receptor α (ERα). However, drug resistance to TAM remains a significant challenge in breast cancer treatment. In this study, we aimed to design an actively targeted drug delivery system to enhance the proliferation inhibitory effects of TAM on ER positive breast cancer cells. Herein, chitosan (CS) was modified with genistein (GEN) to obtain the actively targeted GEN-CS. The TAM-loaded nanoparticles (TAM-GEN-CS-NPs) were constructed using an ionic-crosslinking method, with GEN-CS as the carrier material and sodium tripolyphosphate (TPP) as the crosslinking agent. As a result, TAM-GEN-CS-NPs exhibited a spherical morphology with an average size of 299.8 nm. The encapsulation efficiency and drug loading content were 85.77% and 14.13 µg/mg, respectively. Compared with free TAM, TAM-GEN-CS-NPs displayed obvious slow-release performance. In vitro cellular assays demonstrated that TAM-GEN-CS-NPs had active targeting and proliferation inhibitory effects on MCF-7 cells. The IC50 of TAM and TAM-GEN-CS-NPs were 10.25 µg/mL and 7.22 µg/mL, respectively. More importantly, the combination index (CI) value of TAM and GEN was less than 1, indicating synergistic effects. Therefore, TAM-GEN-CS-NPs hold the potential to enhance TAM therapy for breast cancer through active targeting and synergistic treatment strategies.

Abstract 5702: BTX-9341, a bifunctional degrader of CDK4 and CDK6 for glioblastoma multiforme

Abstract Glioblastoma multiforme (GBM) is an aggressive form of brain cancer with limited treatment options. GBM has a high frequency of dysregulation of the CDKN2A-cyclin D-CDK4/CDK6 signaling node and should subsequently be sensitive to CDK4/6 inhibition. Despite this, the CDK4/6 inhibitors that are approved for HR+/HER2- breast cancer have shown limited efficacy in GBM due to poor blood brain barrier (BBB) penetration. BTX-9341 is a Cereblon (CRBN) mediated CDK4/6 bifunctional degrader that we have developed for HR+/HER2- breast cancer. This degrader shows good exposure in brain tissues with a high brain to plasma ratio. Given the exposure in the brain, we explored the in vitro and in vivo efficacy of BTX-9341 in GBM cell line and xenograft models. GBM cell lines treated with BTX-9341 showed up to 86% degradation of CDK4 and CDK6 with DC50s &amp;lt;1nM. CDK4/6 phosphorylates the protein RB which releases the transcription factor E2F, inducing the expression of genes which promote cell cycle progression. We examined RB phosphorylation by immunoblot and cell cycle progression by propidium iodide staining followed by flow cytometry. BTX-9341 was potent in all downstream assays, with phospho-RB IC50s &amp;lt;10nM, and G0/G1 cell cycle arrest at concentrations as low as 10nM. We used a 2D colony formation assay (CFA) to assess inhibition of proliferation by cell cycle arrest. BTX-9341 potently inhibited cell proliferation with CFA IC50s of 13-100nM in GBM cell lines. BTX-9341 displays excellent pharmacokinetic properties with good oral bioavailability and high brain to plasma ratios which allowed for oral dosing in both subcutaneous and orthotopic xenograft studies. We examined tumor growth inhibition efficacy in two GBM xenograft models: an intracranial U87 model and a subcutaneous U118 model and saw robust tumor growth inhibition in both models with BTX-9341 treatment. The U118 cells have partially unmethylated MGMT, which lead to a loss of efficacy of temozolomide over time, while BTX-9341 maintained inhibition of tumor growth. This indicates that BTX-9341 may be effective in patient populations for which temozolomide is ineffective. The U87 intracranial xenograft model also showed dose-dependent tumor growth inhibition upon treatment with BTX-9341, indicating that BTX-9341 can cross the BBB and reach concentrations high enough to execute cell proliferation inhibition effects. BTX-9341 treated mice also had much better survival than abemaciclib treated mice, the only CDK4/6i which has BBB penetration. These results show that BTX-9341 displays excellent single agent activity in vitro and in vivo in GBM models. The xenograft data indicates that BTX-9341 can inhibit growth of MGMT methylated and unmethylated GBM cell lines, and that BTX-9341 can inhibit tumor growth in the brain more effectively than BBB penetrant CDK4/6i. Together this data shows that BTX-9341 may be a promising candidate for treating GBM. Citation Format: Hannah Majeski, Kirti Chahal, Akinori Okano, Angela Pasis, Casey Carlson, Arvind Shakya, Qiao Liu, Shenlin Huang, Aparajita Hoskote Chourasia, Leah Fung. BTX-9341, a bifunctional degrader of CDK4 and CDK6 for glioblastoma multiforme [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5702.

New Alkaloids and Steroids from Hydranth of Goniopora columna Corals and Their Inhibiting Lung Cancer Cell Activities.

A new alkaloids, aplysingoniopora A (1), and new configuration pregnane type steroid compound, 9,17-α-pregn-1,4,20-en-3-one (2), and two known pregnane type steroid compounds (3 and 4) were isolated from hydranth of Goniopora columna corals. The compounds structures and absolute configurations were determined by extensive spectroscopic analysis, MS data, single-crystal X-ray diffraction analysis and quantum chemical calculation. The anticancer effect of the compounds were explored in human non-small-cell lung cancer (NSCLC) A549 cell lines. As the results, the compound 3 and 4 induces toxicity and has proliferation inhibitory effects on A549 cells (IC50=58.99 μM and 58.77 μM, respectively) in vitro.

Arresting the bad seed: HDAC3 regulates proliferation of different microglia after ischemic stroke.

The accumulation of self-renewed polarized microglia in the penumbra is a critical neuroinflammatory process after ischemic stroke, leading to secondary demyelination and neuronal loss. Although known to regulate tumor cell proliferation and neuroinflammation, HDAC3's role in microgliosis and microglial polarization remains unclear. We demonstrated that microglial HDAC3 knockout (HDAC3-miKO) ameliorated poststroke long-term functional and histological outcomes. RNA-seq analysis revealed mitosis as the primary process affected in HDAC3-deficent microglia following stroke. Notably, HDAC3-miKO specifically inhibited proliferation of proinflammatory microglia without affecting anti-inflammatory microglia, preventing microglial transition to a proinflammatory state. Moreover, ATAC-seq showed that HDAC3-miKO induced closing of accessible regions enriched with PU.1 motifs. Overexpressing microglial PU.1 via an AAV approach reversed HDAC3-miKO-induced proliferation inhibition and protective effects on ischemic stroke, indicating PU.1 as a downstream molecule that mediates HDAC3's effects on stroke. These findings uncovered that HDAC3/PU.1 axis, which mediated differential proliferation-related reprogramming in different microglia populations, drove poststroke inflammatory state transition, and contributed to pathophysiology of ischemic stroke.

A Morpholine Derivative N-(4-Morpholinomethylene)ethanesulfonamide Induces Ferroptosis in Tumor Cells by Targeting NRF2.

Small molecule drugs containing morpholine-based moieties have become crucial candidates in the tumor targeted therapy strategies, but the specific molecular mechanisms of these drugs causing tumor cell death require further investigation. The morpholine derivative N-(4-morpholinomethylene)ethanesulfonamide (MESA) was used to stimulate prostate and ovarian cancer cells and we focused on the ferroptosis effects, including the target molecule and signal pathways mediated by MESA. The results showed that MESA could induce ferroptosis to cause the proliferation inhibition and apoptosis effects of tumor cells according to the identification of ferroptosis inhibitor fer-1 and other cell death inhibitors. Further MESA could significantly increase the intracellular malondialdehyde (MDA), reactive oxygen species (ROS) and Fe2+ levels in tumor cells and mediate the dynamic changes of ferroptosis-relative molecules GPX4, nuclear factor erythroid2-related factor 2 (NRF2), ACSL4, SLC7A11 and P62-Kelch-like ECH-associated protein 1 (KEAP1)-NRF2-antioxidant response element (ARE) signal pathways. Further, NRF2 overexpression could reduce the tumor cell death and ROS levels exposure to MESA. Most importantly, it was confirmed that MESA could bind to NRF2 protein through molecular docking and thermal stability assays and NRF2 was a target molecule of MESA for inducing ferroptosis effects in tumor cells. Collectively, our findings indicated the ferroptosis effects of the morpholine derivative MESA in prostate and ovarian cancer cells and its function mechanism including targeted molecule and signal pathways, which would be helpful for developing MESA as a prospective small molecule drug for cancer therapy based on cell ferroptosis.

Histone H1.2 Inhibited EMCV Replication through Enhancing MDA5-Mediated IFN-β Signaling Pathway.

Histone H1.2 is a member of the linker histone family, which plays extensive and crucial roles not only in the regulation of chromatin dynamics, cell cycle, and cell apoptosis, but also in viral diseases and innate immunity response. Recently, it was discovered that H1.2 regulates interferon-β and inhibits influenza virus replication, whereas its role in other viral infections is poorly reported. Here, we first found the up-regulation of H1.2 during Encephalomyocarditis virus (EMCV) infection, implying that H1.2 was involved in EMCV infection. Overexpression of H1.2 inhibited EMCV proliferation, whereas knockdown of H1.2 showed a significant promotion of virus infection in HEK293T cells. Moreover, we demonstrated that overexpression of H1.2 remarkably enhanced the production of EMCV-induced type I interferon, which may be the crucial factor for H1.2 proliferation-inhibitory effects. We further found that H1.2 up-regulated the expression of the proteins of the MDA5 signaling pathway and interacted with MDA5 and IRF3 in EMCV infection. Further, we demonstrated that H1.2 facilitated EMCV-induced phosphorylation and nuclear translocation of IRF3. Briefly, our research uncovers the mechanism of H1.2 negatively regulating EMCV replication and provides new insight into antiviral targets for EMCV.

Engineering a pH-responsive polymeric micelle co-loaded with paclitaxel and triptolide for breast cancer therapy.

Breast cancer has overtaken lung cancer as the number one cancer worldwide. Paclitaxel (PTX) is a widely used first-line anti-cancer drug, but it is not very effective in clinical breast cancer therapy. It has been reported that triptolide (TPL) can enhance the anticancer effect of paclitaxel, and better synergistic therapeutic effects are seen with concomitant administration of PTX and TPL. In this study, we developed pH-responsive polymeric micelles for co-delivery of PTX and TPL, which disassembling in acidic tumour microenvironments to target drug release and effectively kill breast cancer cells. Firstly, we synthesized amphiphilic copolymer mPEG2000-PBAE through Michael addition reaction, confirmed by various characterizations. Polymer micelles loaded with TPL and PTX (TPL/PTX-PMs) were prepared by the thin film dispersion method. The average particle size of TPL/PTX-PMs was 97.29 ± 1.63 nm, with PDI of 0.237 ± 0.003 and Zeta potential of 9.57 ± 0.80 mV, LC% was 6.19 ± 0.21%, EE% was 88.67 ± 3.06%. Carrier material biocompatibility and loaded micelle cytotoxicity were assessed using the CCK-8 method, demonstrating excellent biocompatibility. Under the same drug concentration, TPL/PTX-PMs were the most toxic to tumour cells and had the strongest proliferation inhibitory effect. Cellular uptake assays revealed that TPL/PTX-PMs significantly increased intracellular drug concentration and enhanced antitumor activity. Overall, pH-responsive micellar co-delivery of TPL and PTX is a promising approach for breast cancer therapy.

Matrine Targets BTF3 to Inhibit the Growth of Canine Mammary Tumor Cells.

The canine mammary tumor model is more suitable for studying human breast cancer, and the safety concentrations of matrine and the biotin-labeled matrine probe were determined in canine primary mammary epithelial cells, and then selected canine mammary tumor cell lines CHMm and CHMp were incubated with matrine, and cell viability was detected by CCK-8. The biotin-labeled matrine probe was used to pull-down the targets of matrine in canine mammary tumor cells, and the targets were screened in combination with activity-based protein profiling (ABPP) and Genecards database, and verified by qPCR and western blot. The results showed that the maximum non-cytotoxic concentrations of matrine and biotin-labeled matrine probe in canine primary mammary epithelial cells were 250 μg/mL and 500 μg/mL, respectively. Matrine and biotin-labeled matrine probe had a proliferation inhibitory effect time-dependently on CHMm and CHMp cells within a safe concentration range, and induced autophagy in cells. Then BTF3 targets were obtained by applying ABPP and Genecards screening. Cellular thermal shift assay (CETSA) findings indicated that matrine could increase the heat stability of BTF3 protein. Pull-down employing biotin-labeled matrine probe with CHMm and CHMp cell lysates revealed that BTF3 protein was detected in the biotin-labeled matrine probe group and that BTF3 protein was significantly decreased by the addition of matrine. The qPCR and western blot findings of CHMm and CHMp cells treated with matrine revealed that matrine decreased the expression of the BTF3 gene and protein with the extension of the action time, and the impact was more substantial at the protein level, respectively.

Diaporaustalides A-L, Austalide Meroterpenoids from a Plant Endophytic Diaporthe sp.

Twelve new austalide meroterpenoids (1-12) were isolated from the endophytic fungus Diaporthe sp. XC1211. Their structures were elucidated by extensive spectroscopic analysis. The absolute configurations of compounds 1, 3, 4, and 6 were established by single-crystal X-ray diffraction, whereas those for the others were established by experimental electronic circular dichroism (ECD) data analysis. Compounds 1-12 represent a rare class of austalides with a 24α-CH3. Compounds 2 and 5 demonstrated potent proliferation inhibitory effects against LPS-induced B cells with IC50 values of 6.7 (SI = 3.6) and 3.8 (SI > 13) μM, respectively. Compounds 2 and 5 decreased the secretion of IL-6 in LPS-induced B cells in a dose-dependent manner.

Unveiling the role of miR-137-3p/miR-296-5p/SERPINA3 signaling in colorectal cancer progression: integrative analysis of gene expression profiles and in vitro studies

BackgroundColorectal cancer (CRC) is a prevalent malignancy worldwide, with increasing incidence and mortality rates. Although treatment options have improved, CRC remains a leading cause of death due to metastasis. Early intervention can significantly improve patient outcomes, making it crucial to understand the molecular mechanisms underlying CRC metastasis. In this study, we performed bioinformatics analysis to identify potential genes associated with CRC metastasis.MethodsWe downloaded and integrated gene expression datasets (GSE89393, GSE100243, and GSE144259) from GEO database. Differential expression analysis was conducted, followed by Gene Ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. The hub gene SERPINA3 was selected for further in vitro functional studies. Additionally, the role of miR-137-3p/miR-296-5p/ Serpin family A member 3 (SERPINA3) in CRC cell function was investigated using in vitro assays.ResultsAnalysis of the gene expression datasets revealed differentially expressed genes (DEGs) associated with CRC metastasis. GO analysis showed enrichment in biological processes such as blood coagulation regulation and wound healing. Cellular component analysis highlighted extracellular matrix components and secretory granules. Molecular function analysis identified activities such as serine-type endopeptidase inhibition and lipoprotein receptor binding. KEGG analysis revealed involvement in pathways related to complement and coagulation cascades, cholesterol metabolism, and immune responses. The common DEGs among the datasets were further investigated. We identified SERPINA3 as a hub gene associated with CRC metastasis. SERPINA3 exerted enhanced effects on migration, proliferation and epithelial-mesenchymal transition (EMT) and inhibitory effects on caspase-3/-9 activities in HT29 and SW620 cells. MiR-137-3p overexpression increased activities of caspase-3/-9, decreased migration and proliferation, and also repressed EMT in HT29 cells, which were obviously attenuated by SERPINA3 enforced overexpression. Consistently, SERPINA3 enforced overexpression also largely reversed miR-296-5p mimics-induced increased in activities of caspase-3/-9, decrease in migration, proliferation and EMT in HT29 cells.ConclusionThrough bioinformatics analysis, we identified potential genes associated with CRC metastasis. The functional studies focusing on SERPINA3/miR-137-3p/miR-296-5p further consolidated its role in regulating CRC progression. Our findings provide insights into novel mechanisms underlying CRC metastasis and might contribute to the development of effective treatment strategies. However, the role of SERPINA3/miR-137-3p/miR-296-5p signaling in CRC still requires further investigation.

10168-BOT-2 ANTITUMOR AROMA THERAPY WITH LEMONGRASS ESSENTIAL OIL FOR GLIOBLASTOMA

Abstract Aromatic essential oils have been used in cancer treatment to enhance immunity, induce sedation, and reduce the side effects of chemotherapy. Recently, essential oils have been reported to have anti-tumor effects. We have been investigating anti-tumor aroma of essential oils as a novel treatment for glioblastoma and have found that hiba essential oil has a proliferation inhibitory effect. In this study, we investigated the antitumor effect of lemongrass essential oil for glioblastoma and its antitumor aromatherapy. Human glioblastoma cells (U87, T98G) and mouse brain tumor cells (RSV-M) were used. Lemongrass essential oil was added to each tumor cell line, and growth inhibition was observed in all cell lines. In addition, lemon grass essential oil showed growth inhibition effect when the tumor cells were separated from the oil, as was the case with direct administration, suggesting that the lemongrass essential oil components that evaporated acted on tumor cells in the surrounding area. The antitumor component of lemongrass essential oil was isolated and identified as citral, an antitumor factor, by gas chromatography. Analysis of the effects of citral showed that it strongly inhibited MARK4 activity and growth in three cell lines. The mechanism revealed that citral decreased the phosphorylation of Tau protein. MARK4 is highly expressed in glioblastoma and has been reported to be involved in cell proliferation. This study suggests a potential mechanism for citral to inhibit tumor cell proliferation via MARK4 in malignant gliomas. Citral is a volatile monoterpene and may exert its antitumor effect by evaporation diffusion. Lemongrass essential oil contains citral, which shows antitumor effects, and is expected to be applied to a new glioblastoma therapy using "aroma".

Abstract A033: Anti-proliferative effects of lentinan, a beta-glucan from shiitake mushroom (lentinula edodes)

Abstract Cancer is one of the most significant health challenges worldwide. Lentinan, a β-glucan from shiitake mushroom, Lentinula edodes, has been demonstrated to have an inhibitory effect on selected cancer cells, but results are inconclusive. The aim of the present study was to investigate the anti-proliferative effect of lentinan on breast adenocarcinoma cells (MCF-7), prostate carcinoma (DU-145), and ovarian carcinoma (SKOV3) using MTS (3-(4,5-dimethylthiazol-2-yl)-5—(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay and explore possible mechanisms of action of this compound. In the MCF-7 cells that were used as a positive control, lentinan without phenol red resulted in a significant inhibition of cell viability by 96% while in the presence of phenol red, the weak estrogen effect attributable to phenol red eliminated the significant inhibitory effect of lentinan. Treatment of DU-145 cells with different doses of lentinan resulted in up to a 42% inhibition in cell growth. In SKOV3 cells, lentinan induced a biphasic response where doses of 800 µg/ml or less increased cell viability by 76% – 148%; however, a dose of 1.6 mg/ml inhibited cell proliferation significantly by 87%. When SKOV3 cells were co-treated with lentinan (800 µg/ml or less) and laminarin (a Dectin-1 receptor antagonist), the proliferation-promoting effect of lentinan was dominant over the proliferation-inhibiting effect of laminarin. However, when lentinan was presented at significant higher levels (1600 µg/ml), the inhibitory effect of the two agents became additive in suppressing SKOV3 cell proliferation. Lentinan induced a biphasic response in human ovarian surface epithelial cells (HOSEpC) similar to SKOV3 cells, where the highest dose (1600 µg/ml) resulted in the inhibition of cell growth by 53%. Western blots after treatment of SKOV3 cells with 1600 µg/ml of lentinan demonstrated caspase-3 activation and a decreased anti-apoptotic protein Bcl-2 levels. Our findings reveal that lentinan can be considered as a potential anti-cancer drug for effective treatment of breast and prostate cancer. Citation Format: Titus Sombuor, Kenneth Shane Broughton, Michael Bergel. Anti-proliferative effects of lentinan, a beta-glucan from shiitake mushroom (lentinula edodes) [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A033.

CRM1/XPO1-FOXO1 Pathway Is Associated with Clinical Outcome and Represents a Promising Target in B-Cell Acute Lymphocytic Leukemia

Background: Currently, a proportion of B-Cell Acute Lymphocytic Leukemia (B-ALL) patients still show no response to existing therapeutic drugs and existing therapeutic drugs cannot further improve the prognosis of refractory and relapsed B-ALL. Thus, the development of a new therapeutic target to battle this deadly disease is imperative. Exportin-1 (XPO1), also known as chromosomal region maintenance 1(CRM1), plays an important role in the progression of tumorigenesis. However, the prognostic and therapeutic values of XPO1 in B-ALL have not been reported. Methods: The difference in XPO1 and Foxo1 expression between normal B cells and leukemia cells was using the Human Protein Atlas (HPA) dataset and RT-qPCR results. Correlations between XPO1 expression level and clinical outcome were analyzed using the RNA-seq data of 110 newly diagnosed B−ALL patients in Nanfang Hospital. Cell proliferation assays, apoptosis assays, and cell cycle analysis were performed to analyze the anti-tumor effects of selinexor (KPT-330) in vitro. Bioinformatics analysis, western blot, and RT-qPCR were performed to explore the underlying mechanism. Results ： Higher XPO1 levels or Foxo1 levels were associated with poor prognosis in newly diagnosed B-ALL patients. Using bone marrow (BM)， peripheral blood (PB) cells from B-ALL and normal people as well as B-ALL cell lines, we found that XPO1 and Foxo1 expression was significantly increased in B-ALL patients and B-ALL cell lines. And notably, there was a positive correlation between the expression of Foxo1 and XPO1, which was verified by the data in the HPA database, and the results were consistent. Foxo1 is an important transcription factor in B-ALL, mainly localized in the nucleus, and is important for leukemia cell survival. KPT-330 (Selinexor), a selective Inhibitor of XPO1, mechanistically inhibited the expression of Foxo1, a leukemia transcription factor (reduced in both the nuclear and cytoplasmic compartments), and led to a strong repression of Foxo1 target genes associated with cell cycle, DNA replication, and transcriptional regulation. This induced growth inhibition, apoptosis, and cycle arrest in B-ALL cells. Moreover, in combination with Foxo1 Inhibitor (AS1842856), the proliferation inhibition and apoptosis-inducing effects of KPT-330 on B-ALL could be significantly enhanced. Furthermore, the KPT-330 strongly triggered apoptosis in leukemic but with minimal effects on normal cells implying that drugs of this class show promise for the targeted therapy of B-ALL leukemia cells. Conclusions: Our findings demonstrate that XPO1 is a promising prognostic indicator and a valid target for antitumor treatment with selective inhibitor KPT-330. This research was supported by the National Natural Science Foundation of China(NFSC82170163, 81970147), Clinical Study of Nanfang Hospital(LC2016ZD009/2019CR012).

Design and synthesis of the first PARP-1 and proteasome dual inhibitors to treat breast cancer

PARP-1 is a crucial factor in repairing DNA single strand damage and maintaining genomic stability. However, the use of PARP-1 inhibitors is limited to combination with chemotherapy or radiotherapy, or as a single agent for indications carrying HRR defects. The ubiquitin-proteasome system processes the majority of cellular proteins and is the principal manner by which cells regulate protein homeostasis. Proteasome inhibitors can cooperate with PARP-1 inhibitors to inhibit DNA homologous recombination repair function. In this study, we designed and synthesized the first dual PARP-1 and proteasome inhibitor based on Olaparib and Ixazomib. Both compounds 42d and 42i exhibited excellent proliferation inhibition and dual-target synergistic effects on cells that were insensitive to PARP-1 inhibitors. Further mechanistic evaluations revealed that 42d and 42i could inhibit homologous recombination repair function by down-regulating the expression of BRCA1 and RAD51. Additionally, 42i induced more significant apoptosis and showed better inhibitory effect on cell proliferation in clonal formation experiments in breast cancer cells than 42d. In summary, our study presented a new class of dual PARP-1/proteasome inhibitors with significant synergistic effects for the treatment of breast cancer.

A versatile strategy to construct surface functionalized pH/redox dual stimuli‐responsive nanogels for targeted drug delivery

AbstractDeveloping facile, green, and efficient synthetic methodology for preparing surface‐functionalized nanogels has attracted tremendous attention in the field of polymer chemistry and biomaterials engineering. Herein, a series of “clickable” P(MAA‐PMA) nanogels with reactive alkyne groups were conveniently prepared by “one‐pot” reflux‐precipitation polymerization (RPP), their particle sizes and zeta potentials are solid content‐dependent. Using P(MAA‐PMA)‐1 nanogels as the model, the physicochemical properties including particle size, surface potential, morphology, solution stability, and pH/redox responsiveness were characterized in detail. Moreover, the pH/redox dual‐responsive drug release feature/kinetics and parameters were analyzed using Korsmeyer–Peppas model and Gallagher–Corrigan model. Then the surface of nanogels was facilely modified with various thiol‐containing functional ligands via thiol‐yne photo click reaction. As targeted drug carriers, doxorubicin (DOX)‐loaded folic acid (FA)‐functionalized nanogels (FA@Nanogels/DOX) demonstrated higher tumor cell proliferation inhibition effect in B16F10 cancer cells than that in CHO‐K1 normal cells, while the non‐FA‐functionalized counterparts (Nanogels/DOX) do not show similar effect. This work provides a versatile “one‐pot RPP‐photo Click functionalization” strategy to construct surface‐functionalized pH/redox dual responsive nanogels for efficient and targeted drug delivery.

Ezetimibe inhibits triple-negative breast cancer proliferation and promotes cell cycle arrest by targeting the PDGFR/AKT pathway

Cholesterol levels were strongly associated with tumor progression and metastasis. Targeted cholesterol metabolism has broad prospects in tumor treatment. Ezetimibe, the only FDA-approved inhibitor of cholesterol absorption, has been reported to be able to inhibit angiogenesis in liver cancer. However, the efficacy and specific mechanisms of Ezetimibe in the treatment of Triple-Negative Breast Cancer (TNBC)have not been reported. Our research shows Ezetimibe inhibits TNBC cell proliferation and blocks the cell cycle in the G1 phase. Mechanistically, Ezetimibe inhibits the activation of PDGFRβ/AKT pathway, thereby promoting cell cycle arrest and inhibiting cell proliferation. By overexpressing PDGFRβ in TNBC cells, we found that PDGFRβ significantly reduced the inhibitory effect of Ezetimibe on TNBC cell proliferation and the cell cycle. Similarly, SC79, an AKT agonist, can reduce the proliferation inhibitory and cycle-blocking effects of Ezetimibe on TNBC cells. Furthermore, the AKT inhibitor MK2206 enhanced the inhibitory effect of Ezetimibe on the cell cycle and proliferation ability of TNBC cells overexpressing PDGFRβ. In xenograft tumor models, we also found that Ezetimibe inhibited TNBC growth, an effect that can be blocked by overexpression of PDGFR or activation of AKT. In summary, we have demonstrated that EZ inhibits the PDGFR/AKT pathway, thereby halting TNBC cycle progression and tumor growth.