Tumor Growth Research Articles

Major considerations on the relationship of triple negative breast cancer with microRNAs and nutrological triggers: a systematic review

Introduction: Triple-negative breast cancer (TNBC) accounts for 15% of all cases. Its incidence is usually higher in young women (under 40 years of age). The classification as triple-negative occurs because, in this case, there are no estrogen, progesterone, and HER2 receptors, which are responsible for controlling tumor growth. Higher levels of physical activity and better diet quality are associated with lower mortality from breast cancer in observational studies. Furthermore, physical activity and optimal nutrition can improve the relative dose intensity of chemotherapy, as they can activate miRNAs that regulate several biological processes. Objective: This was to conduct a systematic review to establish the main considerations of the relationship between triple-negative breast cancer and microRNAs as biomarkers and regulators of gene expression in cancer cells, as well as to show some nutritional triggers of microRNA activation desirable for breast cancer control. Methods: The PRISMA Platform systematic review rules were followed. The search was conducted from April to June 2024 in the Web of Science, Scopus, PubMed, Science Direct, Scielo, and Google Scholar databases. The quality of the studies was based on the GRADE and AMSTAR-2 instrument and the risk of bias was analyzed appropriately. According to the Cochrane instrument. Results and Conclusion: 112 articles were found, and 40 were evaluated in full and included in this article, 22 of which were included in the systematic review. Considering the Cochrane tool for risk of bias, the global assessment resulted in 15 studies with a high risk of bias and 25 studies that did not reach GRADE and AMSTAR-2. Most studies showed homogeneity in their results, with X2=81.5%>50%. It was concluded that an increasing number of studies have shown that non-coding RNA (ncRNA), including microRNA (miRNA) and long non-coding RNA (lncRNA), play a significant role in tumorigenesis. Although a diet and exercise intervention did not affect relative dose intensity, the intervention was associated with a higher pCR in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative and triple-negative breast cancer undergoing neoadjuvant chemotherapy. High expression levels of miR-27a/b, miR-210, and miR-454 were associated with shorter overall survival, whereas high expression levels of miR-454 and miR-374a/b were associated with disease-free survival. The miRNAs associated with triple-negative breast cancer may provide new avenues for early diagnosis and treatment of breast cancer. Furthermore, specific miRNAs may serve as potential prognostic biomarkers in triple-negative breast cancer.

Inflammation mediated by gut microbiome alterations promotes lung cancer development and an immunosuppressed tumor microenvironment.

Accumulating evidence indicates that the gut microbiome influences cancer progression and therapy. We recently showed that progressive changes in gut microbial diversity and composition are closely associated with tobacco-associated lung adenocarcinoma (LUAD) in a human-relevant mouse model. Furthermore, we demonstrated that the loss of the antimicrobial protein Lcn2 in these mice, exacerbates pro-tumor inflammatory phenotypes while further reducing microbial diversity. Yet, how gut microbiome alterations impinge on LUAD development remains poorly understood. Here, we investigated the role of gut microbiome changes in LUAD development using fecal microbiota transfer and delineated a pathway by which gut microbiome alterations incurred by loss of Lcn2 fostered the proliferation of pro-inflammatory bacteria of the genus Alistipes, triggering gut inflammation. This inflammation propagated systemically, exerting immunosuppression within the tumor microenvironment, augmenting tumor growth through an IL-6-dependent mechanism and dampening response to immunotherapy. Corroborating our preclinical findings, we found that patients with LUAD with a higher relative abundance of Alistipes species in the gut showed diminished response to neoadjuvant immunotherapy. These insights reveal the role of microbiome-induced inflammation in LUAD and present new potential targets for interception and therapy.

Exosomal miR-4745-5p/3911 from N2-polarized tumor-associated neutrophils promotes gastric cancer metastasis by regulating SLIT2

Tumor cells remodel the phenotype and function of tumor microenvironment (TME) cells to favor tumor progression. Previous studies have shown that neutrophils in TME are polarized to N2 tumor-associated neutrophils (TANs) by tumor derived factors, thus promoting tumor growth and metastasis, angiogenesis, therapy resistance, and immunosuppression. Exosomes act as critical intercellular messengers in human health and diseases including cancer. So far, the biological roles of exosomes from N2 TANs in gastric cancer have not been well characterized. Herein, we represented the first report that exosomes from N2 TANs promoted gastric cancer metastasis in vitro and in vivo. We found that exosomes from N2 TANs transferred miR-4745-5p/3911 to gastric cancer cells to downregulate SLIT2 (slit guidance ligand 2) gene expression. Adenovirus-mediated overexpression of SLIT2 reversed the promotion of gastric cancer metastasis by N2 TANs derived exosomes. We further revealed that gastric cancer cells induced glucose metabolic reprogramming in neutrophils through exosomal HMGB1 (high mobility group protein B1)/NF-κB pathway, which mediated neutrophil N2 polarization and miR-4745-5p/3911 upregulation. We further employed ddPCR (droplet digital PCR) to detect the expression of miR-4745-5p/3911 in N2 TANs exosomes from human serum samples and found their increased levels in gastric cancer patients compared to healthy controls and benign gastric disease patients. Conclusively, our results indicate that N2 TANs facilitate cancer metastasis via regulation of SLIT2 in gastric cancer cells by exosomal miR-4745-5p/3911, which provides a new insight into the roles of TME cells derived exosomes in gastric cancer metastasis and offers a potential biomarker for gastric cancer diagnosis.

Nonclinical characterization of ICVB-1042 as a selective oncolytic adenovirus for solid tumor treatment

ICVB-1042 is an oncolytic adenovirus containing modifications to enhance replication, lysis, and viral spreading in tumor cells. The anti-tumor activity, immune activation, tropism, selectivity, and mechanism of action were evaluated in preparation for a first-in-human study. ICVB-1042 was at least 100-fold more cytotoxic in A549 cells than in normal primary cells tested, demonstrating its high tumor selectivity and a low likelihood of targeting primary tissues. ICVB-1042 administered to mice intravenously or intratumorally was effective in reducing tumor burden. Its intravenous administration also inhibited tumor growth in orthotopic models. ICVB-1042 was well tolerated in mice compared to HAdV-C5 (Wt Ad5), with reduced liver sequestration, supporting safety of the drug for systemic delivery. These preclinical data demonstrating the safety and potency of ICVB-1042 for treatment of various solid tumors support the ongoing clinical investigation (NCT05904236).

Inhibition of osteosarcoma metastasis in vivo by targeted downregulation of MMP1 and MMP9

Osteosarcoma (OS) mortality stems from lung metastases. Matrix metalloproteinases (MMPs) facilitate metastatic dissemination by degrading extracellular matrix components. Herein we studied the impact of targeted MMP downregulation on OS metastasis. Differential gene expression analysis of human OS cell lines revealed high MMP9 expression in the majority of OS cell lines. Furthermore, 143B, a metastatic OS cell line, exhibited increased MMP1 and MMP9 mRNA levels. Gene set enrichment analysis on metastatic and non-metastatic OS patient specimens indicated epithelial-mesenchymal transition as the most enriched gene set, with MMP9 displaying strong association to genes in this network. Using the same dataset, Kaplan-Meier analysis revealed a correlation between MMP1 expression and dismal patient survival. Hence, we undertook targeted suppression of MMP1 and MMP9 gene expression in OS cell lines. The ability of OS cells to migrate and form colonies was markedly reduced upon MMP1 and MMP9 downregulation, whereas their cell proliferation capacity remained intact. MMP9 downregulation decreased tumor growth and lung metastases area in an orthotopic mouse OS model. Consistently, human OS lung metastasis specimens displayed marked MMP9 protein expression. Our findings highlight the role of MMP1 and MMP9 in OS metastasis, warranting further exploration of simultaneous inhibition of MMPs for future OS therapeutics.

Novel PROTAC probes targeting KDM3 degradation to eliminate colorectal cancer stem cells through inhibition of Wnt/β-catenin signaling.

It has been demonstrated that the KDM3 family of histone demethylases (KDM3A and KDM3B) epigenetically control the functional properties of colorectal cancer stem cells (CSCs) through Wnt/β-catenin signaling. Meanwhile, a broad-spectrum histone demethylase inhibitor, IOX1, suppresses Wnt-induced colorectal tumorigenesis predominantly through inhibiting the enzymatic activity of KDM3. In this work, several cereblon (CRBN)-recruiting PROTACs with various linker lengths were designed and synthesized using IOX1 as a warhead to target KDM3 proteins for degradation. Two of the synthesized PROTACs demonstrated favorable degradation profile and selectivity towards KDM3A and KDM3B. Compound 4 demonstrated favorable in vitro metabolic profile in liver enzymes as well as no hERG-associated cardiotoxicity. Compound 4 also showed dramatic ability in suppressing oncogenic Wnt signaling to eliminate colorectal CSCs and inhibit tumor growth, with around 10- to 35-fold increased potency over IOX1. In summary, this study suggests that PROTACs provide a unique molecular tool for the development of novel small molecules from the IOX1 skeleton for selective degradation of KDM3 to eliminate colorectal CSCs via suppressing oncogenic Wnt signaling.

PTPRZ1-targeting RNA CAR T cells exert antigen-specific and bystander antitumor activity in glioblastoma.

The great success of chimeric antigen receptor (CAR) T-cell therapy in the treatment of patients with B-cell malignancies has prompted its translation to solid tumors. In the case of glioblastoma (GBM), clinical trials have shown modest efficacy, but efforts to develop more effective anti-GBM CAR T cells are ongoing. In this study, we selected PTPRZ1 as a target for GBM treatment. We isolated six anti-human PTPRZ1 scFv from a human phage display library and produced 2nd generation CAR T cells in an RNA format. Patient-derived GBM PTPRZ1-knock-in cell lines were used to select the CAR construct that showed high cytotoxicity while consistently displaying high CAR expression (471_28z). CAR T cells incorporating 471_28z were able to release IFN-γ, IL-2, TNF-α, Granzyme B, IL-17A, IL-6, and soluble FasL, and displayed low tonic signaling. Additionally, they maintained an effector memory phenotype after in vitro killing. In addition, 471_28z CAR T cells displayed strong bystander killing against PTPRZ1-negative cell lines after pre-activation by PTPRZ1-positive tumor cells but did not kill antigen-negative non-tumor cells. In an orthotopic xenograft tumor model using NSG mice, a single dose of anti-PTPRZ1 CAR T cells significantly delayed tumor growth. Taken together, these results validate PTPRZ1 as a GBM target and prompt the clinical translation of anti-PTPRZ1 CAR T cells.

Mitochondria-Targeting AIEgens as Pyroptosis Inducers for Boosting Type-I Photodynamic Therapy of Tongue Squamous Cell Carcinoma.

The development of a photosensitizer (PS) that induces pyroptosis could be a star for photodynamic therapy (PDT), particularly with type-I PSs that produce reactive oxygen species (ROS) in a hypoxic tumor microenvironment. Since pyroptosis is a recently characterized cell death pathway, it holds promise for advancing PDT in oncology, with PSs playing a critical role. Herein, we develop a PS named Th-M with aggregation-induced emission (AIE) characteristics for type-I PDT against tongue squamous cell carcinoma (TSCC). Th-M stands out for its exceptional mitochondrial-targeting ability, which triggers mitochondrial dysfunction and leads to Caspase-3 and Gasdermin E (GSDME) cleavage under white light irradiation, inducing pyroptosis in TSCC cells. Our studies verify the effectiveness of Th-M in destroying cancer cells in vitro and suppressing tumor growth in vivo while also demonstrating a favorable biosafety profile. This work pioneers the application of Th-M as a mitochondria-targeted, type-I PS that leverages the mechanism of pyroptosis, offering a potent approach for the treatment of TSSC with promising implications for future PDT of cancers.

Focal adhesion kinase-mediated interaction between tumor and immune cells in the tumor microenvironment: implications for cancer-associated therapies and tumor progression.

Focal adhesion kinase (FAK) expression has been linked to tumor growth, immunosuppression, metastasis, angiogenesis, and therapeutic resistance through kinase-dependent and kinase scaffolding functions in the nucleus and cytoplasm. Hence, targeting FAK alone or with other agents has gained attention as a potential therapeutic strategy. Moreover, mounting evidence shows that FAK activity can influence the tumor immune microenvironment crosstalk to support tumor progression. Recently, tumor immune microenvironment interaction orchestrators have shown to be promising therapeutic agents for cancer immunotherapies. Therefore, this review highlights how FAK regulates the tumor immune microenvironment interplay to promote tumor immune evasive mechanisms and their potential for combination therapies with standard cancer treatments.

Blocking tumor-intrinsic MNK1 kinase restricts metabolic adaptation and diminishes liver metastasis.

Dysregulation of the mitogen-activated protein kinase interacting kinases 1/2 (MNK1/2)-eukaryotic initiation factor 4E (eIF4E) signaling axis promotes breast cancer progression. MNK1 is known to influence cancer stem cells (CSCs); self-renewing populations that support metastasis, recurrence, and chemotherapeutic resistance, making them a clinically relevant target. The precise function of MNK1 in regulating CSCs, however, remains unexplored. Here, we generated MNK1 knockout cancer cell lines, resulting in diminished CSC properties in vitro and slowed tumor growth in vivo. Using a multiomics approach, we functionally demonstrated that loss of MNK1 restricts tumor cell metabolic adaptation by reducing glycolysis and increasing dependence on oxidative phosphorylation. Furthermore, MNK1-null breast and pancreatic tumor cells demonstrated suppressed metastasis to the liver, but not the lung. Analysis of The Cancer Genome Atlas (TCGA) data from breast cancer patients validated the positive correlation between MNK1 and glycolytic enzyme protein expression. This study defines metabolic perturbations as a previously unknown consequence of targeting MNK1/2, which may be therapeutically exploited.

SKAP1 Expression in Cancer Cells Enhances Colon Tumor Growth and Impairs Cytotoxic Immunity by Promoting Neutrophil Extracellular Trap Formation via the NFATc1/CXCL8 Axis.

The mechanisms underlying the development and progression of colon cancer are not fully understood. Herein, Src kinase associated phosphoprotein 1 (SKAP1), an immune cell adaptor, is identified as a novel colon cancer-related gene. SKAP1 expression is significantly increased in colon cancer cells. High SKAP1 levels are independently predictive of poor survival in patients with colon cancer. Notably, SKAP1 expression in colon cancer cells exerted a significant tumor-promoting effect in vivo rather than in vitro. Screening of tumor-infiltrating immune cells revealed the involvement of neutrophils in SKAP1-induced colon tumor promotion. Enhanced formation of neutrophil extracellular traps (NETs) is found to be a key downstream event that contributed to the pro-tumor role of SKAP1. In colon cancer cells, SKAP1 increased the expression of C-X-C motif chemokine ligand 8 (CXCL8) via nuclear factor of activated T cells c1 (NFATc1). The blockade of CXCL8 or NFATc1 largely attenuated neutrophil infiltration, NET formation, and tumor promotion induced by SKAP1. Furthermore, inhibiting SKAP1-induced NET significantly enhanced the antitumor efficiency of adoptive natural killer cell therapy in colon tumor models. In conclusion, SKAP1 significantly promotes colon cancer growth via the cancer cell/neutrophil NFATc1/CXCL8/NET axis, suggesting that SKAP1 is a potential target for colon cancer therapy.

SELENBP1 Inhibits the Warburg Effect and Tumor Growth by Reducing the HIF1α Expression in Colorectal Cancer.

Colorectal cancer (CRC) is experiencing a significant increase in both incidence and mortality rates globally. The expression of Selenium-binding protein 1 (SELENBP1) has been reported to be notably downregulated in various malignancies, yet its biological functions and cellular mechanisms in CRC remain incompletely understood. In our investigation, we observed the downregulation of SELENBP1 in CRC tissues through quantitative real-time PCR and western blotting and identified a positive correlation between higher SELENBP1 expression and improved survival prognosis using Kaplan-Meier survival analysis. Through loss-of-function and gain-of-function studies, we demonstrated the tumor-suppressive roles of SELENBP1 in CRC, supported by results from both in vitro and in vivo experiments. Furthermore, we uncovered the pivotal functions of SELENBP1 in suppressing aerobic glycolysis in CRC cells by regulating glucose uptake, lactate generation, and extracellular acidification rate. At a mechanistic level, we found that SELENBP1 inhibits the expression of the key glycolytic modulator hypoxia-inducible factor 1 subunit alpha (HIF1α), and the inhibition of glycolysis by SELENBP1 can be reversed by ectopic expression of HIF1α. Therefore, our study highlights the potential of SELENBP1 as a promising target for CRC therapy, given its significant impact on tumor suppression and reprogrammed glucose metabolism. These findings contribute to a deeper understanding of the molecular mechanisms underlying CRC progression and may pave the way for the development of targeted therapies for this challenging disease.

Mathematical modeling of 18F-Fluoromisonidazole (18F-FMISO) radiopharmaceutical transport in vascularized solid tumors

18F-Fluoromisonidazole (18F-FMISO) is a highly promising positron emission tomography radiopharmaceutical for identifying hypoxic regions in solid tumors. This research employs spatiotemporal multi-scale mathematical modeling to explore how different levels of angiogenesis influence the transport of radiopharmaceuticals within tumors. In this study, two tumor geometries with heterogeneous and uniform distributions of capillary networks were employed to incorporate varying degrees of microvascular density. The synthetic image of the heterogeneous and vascularized tumor was generated by simulating the angiogenesis process. The proposed multi-scale spatiotemporal model accounts for intricate physiological and biochemical factors within the tumor microenvironment, such as the transvascular transport of the radiopharmaceutical agent, its movement into the interstitial space by diffusion and convection mechanisms, and ultimately its uptake by tumor cells. Results showed that both quantitative and semi-quantitative metrics of 18F-FMISO uptake differ spatially and temporally at different stages during tumor growth. The presence of a high microvascular density in uniformly vascularized tumor increases cellular uptake, as it allows for more efficient release and rapid distribution of radiopharmaceutical molecules. This results in enhanced uptake compared to the heterogeneous vascularized tumor. In both heterogeneous and uniform distribution of microvessels in tumors, the diffusion transport mechanism has a more pronounced than convection. The findings of this study shed light on the transport phenomena behind 18F-FMISO radiopharmaceutical distribution and its delivery in the tumor microenvironment, aiding oncologists in their routine decision-making processes.

A - 49 The Role of the Tuberous Sclerosis Associated Neuropsychiatric Disorders Checklist in Pediatric Neuropsychological Assessment: a Case Study

Abstract Objective The Tuberous Sclerosis Associated Neuropsychiatric Disorders (TAND) checklist is a screening tool developed to assist in clarifying behavioral, psychiatric, neuropsychological, and psychosocial manifestations experienced by individuals with Tuberous Sclerosis Complex (TSC). TSC is a multisystem disorder, impacting 1 in 6000 children annually, caused by mutations in the TSC1/TSC2 genes that results in tumor growth throughout the body associated with widespread adverse medical and neurological outcomes including cognition. We present the use of the TAND checklist in a child referred for cognitive evaluation in the context of TSC to explore its potential use within neuropsychological assessment. Method Eleven-year-old female with TSC, referred by neurology, was seen for outpatient neuropsychological evaluation. Comprehensive neuropsychological testing and completion of the TAND checklist with parent were completed. Results Evaluation revealed variable cognitive performances with strengths in fluid reasoning and relative weakness in working memory. Academic performances were low average with weakness in reading. Overall slowed and disrupted processing impacted performance across domains. TAND checklist helped elucidate parental report about cognitive and psychological difficulties. Conclusions This eleven-year-old girl’s profile was variable across domains, consistent with research findings that TSC is a multisystemic disorder presenting in widespread dysfunction. Implementing the TAND checklist was helpful in efficiently eliciting symptomology across domains from parent collateral informant, demonstrating its augmentative value to comprehensive neuropsychological assessment in children with TSC. This is an important next step in validating the TAND checklist in neuropsychological settings.

Andrographolide sensitizes glioma to temozolomide by inhibiting DKK1 expression.

Temozolomide (TMZ) is the first-line chemotherapeutic drug for gliomas treatment. However, the clinical efficacy of TMZ in glioma patients was very limited. Therefore, it is urgently needed to discover a novel approach to increase the sensitivity of glioma cells to TMZ. Western blot, immunohistochemical staining, and qRT-PCR assays were used to explore the mechanisms underlying TMZ promoting DKK1 expression and andrographolide (AND) inhibiting DKK1 expression. HPLC was used to detect the ability of andrographolide (AND) to penetrate the blood-brain barrier. MTT assay, bioluminescence images, magnetic resonance imaging (MRI) and H&E staining were employed to measure the proliferative activity of glioma cells and the growth of intracranial tumors. TMZ can promote DKK1 expression in glioma cells and brain tumors of an orthotopic model of glioma. DKK1 could promote glioma cell proliferation and tumor growth in an orthotopic model of glioma. Mechanistically, TMZ increased EGFR expression and subsequently induced the activation of its downstream MEK-ERK and PI3K-Akt pathways, thereby promoting DKK1 expression in glioma cells. Andrographolide inhibited TMZ-induced DKK1 expression through inactivating MEK-ERK and PI3K-Akt pathways. Andrographolide can cross the blood-brain barrier, the combination of TMZ and andrographolide not only improved the anti-tumor effects of TMZ but also showed a survival benefit in an orthotopic model of glioma. Andrographolide can enhance anti-tumor activity of TMZ against glioma by inhibiting DKK1 expression.

SIRT1-mediated deacetylation of FOXO3 enhances mitophagy and drives hormone resistance in endometrial cancer

BackgroundThe complex interplay between Sirtuin 1 (SIRT1) and FOXO3 in endometrial cancer (EC) remains understudied. This research aims to unravel the interactions of deacetylase SIRT1 and transcription factor FOXO3 in EC, focusing on their impact on mitophagy and hormone resistance.MethodsHigh-throughput sequencing, cell experiments, and bioinformatics tools were employed to investigate the roles and interactions of SIRT1 and FOXO3 in EC. Co-immunoprecipitation (Co-IP) assay was used to assess the interaction between SIRT1 and FOXO3 in RL95-2 cells. Functional assays were used to assess cell viability, proliferation, migration, invasion, apoptosis, and the expression of related genes and proteins. A mouse model of EC was established to evaluate tumor growth and hormone resistance under different interventions. Immunohistochemistry and TUNEL assays were used to assess protein expression and apoptosis in tumor tissues.ResultsHigh-throughput transcriptome sequencing revealed a close association between SIRT1, FOXO3, and EC development. Co-IP showed a protein–protein interaction between SIRT1 and FOXO3. Overexpression of SIRT1 enhanced FOXO3 deacetylation and activity, promoting BNIP3 transcription and PINK1/Parkin-mediated mitophagy, which in turn promoted cell proliferation, migration, invasion, and inhibited apoptosis in vitro, as well as increased tumor growth and hormone resistance in vivo. These findings highlighted SIRT1 as an upstream regulator and potential therapeutic target in EC.ConclusionThis study reveals a novel molecular mechanism underlying the functional relevance of SIRT1 in regulating mitophagy and hormone resistance through the deacetylation of FOXO3 in EC, thereby providing valuable insights for new therapeutic strategies.

4-Hydroxynonenal Promotes Colorectal Cancer Progression through Regulating Cancer Stem Cell Fate.

Tumor microenvironment (TME) plays a crucial role in sustaining cancer stem cells (CSCs). 4-hydroxynonenal (4-HNE) is abundantly present in the TME of colorectal cancer (CRC). However, the contribution of 4-HNE to CSCs and cancer progression remains unclear. This study aimed to investigate the impact of 4-HNE on the regulation of CSC fate and tumor progression. Human CRC cells were exposed to 4-HNE, and CSC signaling was analyzed using quantitative real-time PCR, immunofluorescent staining, fluorescence-activated cell sorting, and bioinformatic analysis. Tumor-promoting role of 4-HNE was confirmed using a xenograft model. Exposure of CRC cells to 4-HNE activated non-canonical Hedgehog (HH) signaling and homologous recombination repair (HRR) pathways in LGR5+ CSCs. Furthermore, blocking HH signaling led to a significant increase in the expression of γH2AX, indicating that 4-HNE induces double-stranded DNA breaks (DSBs) and simultaneously activates HH signaling to protect CSCs from 4-HNE-induced damage via the HRR pathway. Additionally, 4-HNE treatment increased the population of LGR5+ CSCs and promoted asymmetric division in these cells, leading to enhanced self-renewal and differentiation. Notably, 4-HNE also promoted xenograft tumor growth and activated CSC signaling in vivo. These findings demonstrate that 4-HNE, as a signaling inducer in the TME, activates the non-canonical HH pathway to shield CSCs from oxidative damage, enhances the proliferation and asymmetric division of LGR5+ CSCs, and thereby facilitates tumor growth. These novel insights shed light on the regulation of CSC fate within the oxidative TME, offering potential implications for understanding and targeting CSCs for CRC therapy.

Licochalcone A decreases cancer cell proliferation and enhances ferroptosis in acute myeloid leukemia through suppressing the IGF2BP3/MDM2 cascade.

Licochalcone A (Lico A), a naturally bioactive flavonoid, has shown antitumor activity in several types of cancers. However, few studies have focused on its effect on acute myeloid leukemia (AML). Cell viability and colony formation potential were detected by CCK-8 assay and colony formation assay, respectively. Cell cycle distribution and apoptosis were assessed by flow cytometry. Ferroptosis was assessed by measuring reactive oxygen species (ROS), lipid ROS, malondialdehyde (MDA), and glutathione (GSH). Protein expression levels were determined by immunoblotting and immunohistochemistry (IHC), and mRNA expression was detected by real-time qPCR. The m6A modification of MDM2 mRNA was verified by methylated RNA immunoprecipitation (MeRIP) assay, and the interaction of IGF2BP3 and MDM2 mRNA was analyzed by RIP assay. Actinomycin D was used to evaluate mRNA stability. The efficacy of Lico A in vivo was examined by a murine xenograft model. Lico A suppressed cell proliferation and induced ferroptosis in MOLM-13 and U-937 in vitro, and slowed the growth of xenograft tumors in vivo. IGF2BP3 was highly expressed in human AML specimens and cells, and Lico A suppressed IGF2BP3 expression in AML cells. Lico A exerted the anti-proliferative and pro-ferroptosis effects by downregulating IGF2BP3. Moreover, IGF2BP3 enhanced the stability and expression of MDM2 mRNA through an m6A-dependent manner. Downregulation of IGF2BP3 impeded AML cell proliferation and enhanced ferroptosis via repressing MDM2. Furthermore, Lico A could affect the MDM2/p53 pathway by downregulating IGF2BP3 expression. Lico A exerts the anti-proliferative and pro-ferroptosis activity in AML cells by affecting the IGF2BP3/MDM2/p53 pathway, providing new evidence for Lico A as a promising agent for the treatment of AML.

Neuroendocrine Differentiation in Prostate Cancer Requires ASCL1.

Most patients with prostate adenocarcinoma develop resistance to therapies targeting the androgen receptor (AR). Consequently, a portion of these patients develop AR-independent neuroendocrine prostate cancer (NEPC), a rapidly progressing cancer with limited therapies and poor survival outcomes. Current research to understand the progression to NEPC suggests a model of lineage plasticity whereby AR-dependent luminal-like tumors progress towards an AR-independent NEPC state. Genetic analysis of human NEPC identified frequent loss of RB1 and TP53, and the loss of both genes in experimental models mediates the transition to a neuroendocrine lineage. Transcriptomics studies have shown that lineage transcription factors ASCL1 and NEUROD1 are present in NEPC. In this study, we modeled the progression of prostate adenocarcinoma to NEPC by establishing prostate organoids and subsequently generating subcutaneous allograft tumors from genetically-engineered mouse models harboring Cre-induced loss of Rb1 and Trp53 with Myc overexpression (RPM). These tumors were heterogeneous and displayed adenocarcinoma, squamous, and neuroendocrine features. ASCL1 and NEUROD1 were expressed within neuroendocrine-defined regions, with ASCL1 being predominant. Genetic loss of Ascl1 in this model did not decrease tumor incidence, growth, or metastasis; however, there was a notable decrease in neuroendocrine identity and an increase in basal-like identity. This study provides an in vivo model to study progression to NEPC and establishes the requirement for ASCL1 in driving neuroendocrine differentiation in prostate cancer.

Development of a First-in-Class DNMT1/HDAC Inhibitor with Improved Therapeutic Potential and Potentiated Antitumor Immunity.

Epigenetic therapies have emerged as a key paradigm for treating malignancies. In this study, a series of DNMT1/HDAC dual inhibitors were obtained by fusing the key pharmacophores from DNMT1 inhibitors (DNMT1i) and HDAC inhibitors (HDACi). Among them, compound (R)-23a demonstrated significant DNMT1 and HDAC inhibition both in vitro and in cells and largely phenocopied the synergistic effects of combined DNMT1i and HDACi in reactivating epigenetically silenced tumor suppressor genes (TSGs). This translated into a profound tumor growth inhibition (TGI = 98%) of (R)-23a in an MV-4-11 xenograft model, while displaying improved tolerability compared with single agent combination. Moreover, in a syngeneic MC38 mouse colorectal tumor model, (R)-23a outperformed the combinatory treatment in reshaping the tumor immune microenvironment and inducing tumor regression. Collectively, the novel DNMT1/HDAC dual inhibitor (R)-23a effectively reverses the cancer-specific epigenetic abnormalities and holds great potential for further development into cancer therapeutic agents.