Xenograft Tumor Model Research Articles

Targeting CircAURKA prevents colorectal cancer progression via enhancing CTNNB1 protein degradation.

Tumor progression of colorectal cancer (CRC) seriously affects patient prognosis. For CRC patients with advanced-stage disease, it is still necessary to continuously explore more effective targeted therapeutic drugs. Circular RNAs (circRNAs) are involved in the regulation of tumor biology. We screened circAURKA, which was significantly highly expressed in CRC by previous high-throughput RNA sequencing. In vitro experiments were performed to investigate the effect of the circRNA on the proliferation and metastasis of HCT116 and SW480 cells. In addition, we used the EdU assay, Transwell assay, nude mouse xenograft tumor model and nude mouse tail vein metastasis model to examine the effect of circAURKA on the proliferation and metastasis of CRC. Mechanistically, fluorescent in situ hybridization (FISH), RNA pull-down, RNA immunoprecipitation (RIP), protein coimmunoprecipitation (co-IP) experiments and animal models were performed to confirm the underlying mechanisms of circAURKA. CircAURKA was significantly highly expressed in CRC tissues and colorectal cells and mainly present in the cytoplasm. The circRNA promoted the proliferation and metastasis of CRC cells in vitro and in vivo. In terms of the molecular mechanism, circAURKA inhibited the degradation of the CTNNB1 protein by promoting the interaction between ACLY and the CTNNB1 protein, thereby promoting the proliferation and metastasis of CRC cells. In addition, circAURKA stability was regulated by m6A methylation modification. This study revealed that circAURKA promoted the proliferation and metastasis of CRC by inhibiting CTNNB1 protein degradation, providing a basis for the development of targeted drugs to control CRC progression.

Ang-1 promotes tumorigenesis and mediates the anti-cancer effects of Artesunate on Choroidal melanoma via the regulation of Akt/mTOR signaling pathway

The impact of Ang-1 on tumors remains a subject of contention, with its mechanism of action exhibiting complexity in the progression of diverse tumor types. Ang-1 has been shown to promote the progression of glioma, glioma, esophageal and human cervical cancer, whereas it exerts inhibitory effects on the growth of breast and colon cancer. However, the specific function of Ang-1 in CM has not been clarified. This research aims to explore the function of Ang-1 on CM and the underlying mechanism. WB and qPCR were utilized to measure the expression levels of different factors in CM cells. Clonogenic, CCK-8 and Transwell migration assay were used to probe CM cells’ proliferation and migration ability. Xenograft tumor model was used to testify the effect of Ang-1 and Artesunate (ART) on the growth of CM in vivo. We found Ang-1 promoted CM proliferation and migration, while it was inhibited by ART in vitro. Moreover, both ART treatment and Ang-1 knockdown had the effect of suppressing tumor growth in CM xenograft model. Mechanically, Ang-1 activated Akt/mTOR pathway and induced epithelial-mesenchymal transition (EMT) in CM cells. Furthermore, ART regulated Akt/mTOR pathway by decreasing the expression of Ang-1 in CM cells. Ang-1 promotes tumorigenesis of CM by regulating Akt/mTOR pathway, which can be inhibited by ART.

Nifuratel Induces Triple-Negative Breast Cancer Cell G2/M Phase Block and Apoptosis by Regulating GADD45A.

(1) Background: Nifuratel (NF113), derived from nitrofuran, has a specific anti-tumor effect. However, the potential mechanisms of NF113 in triple-negative breast cancer remain unknown. (2) Methods: In the study, CCK8 assay and colony formation assays were used to evaluate the inhibition effect of NF113 on cell proliferation. Apoptosis and cell cycle distribution were tested by flow cytometry. The mechanism of NF113's anti-tumor effect was predicted by transcriptome sequencing and verified by using PCR and Western blot experiments. Breast cancer organoids constructed from the patient-derived tumor xenograft model and the MDA-MB-468 xenograft mouse model were established to evaluate the effect of NF113. (3) Results: Our study showed that NF113 had an anti-tumor effect on triple-negative breast cancer both in vitro and in vivo. NF113 also induced apoptosis and G2/M phase arrest in triple-negative breast cancer cells. Our experimental data further verified that NF113 reduced GADD5A mRNA and protein expression, which were significantly upregulated in breast cancer, with downstream CDC25C and AKT phosphorylation changes. (4) Conclusions: Our data provided compelling evidence that NF113 inhibited breast cancer growth via upregulating GADD45A. Conclusion: NF113 was able to exert inhibitory effects on the proliferation of triple-negative breast cancer in vivo and in vitro, which may induce G2/M phase arrest via the GADD45A/CyclinB/CDK1 pathway and apoptosis via GADD45A/JNK/P38.

Propofol attenuates prostate cancer progression by upregulating TRHDE-AS1 expression, and METTL14 could mediate its m6A modification.

Propofol has become a microtubule-stabilizing drug for prostate cancer (PC) therapy, but propofol resistance impairs the therapeutic effect. This study aimed to explore the regulatory mechanism of propofol in the pathogenesis of PC through mechanisms involving N6-methyladenosine (m6A) modification. The changes in PC cell malignancy were evaluated by means of transwell, cell counting kit 8 (CCK-8), western blotting and tumour xenograft model assays. Long noncoding RNA TRHDE-AS1 and m6A methyltransferase METTL14 expression levels were determined via reverse transcription quantitative polymerase chain reaction (RT-qPCR). The m6A modification of TRHDE-AS1 which was mediated by METTL14 was confirmed by conducting methylated RNA immunoprecipitation (MeRIP) assay. We observed that propofol (200 μM) inhibited PC cell malignancy in vivo and in vitro, elucidating that it impaired cell proliferation, migration and tumour growth but induced apoptosis. TRHDE-AS1 expression was observed to be lower in PC cells and tissues, and propofol induced TRHDE-AS1 upregulation in PC cells. Propofol was capable of reversing the tumour-promoting effect of TRHDE-AS1 knockdown in PC cells. Additionally, METTL14 was upstream of TRHDE-AS1 to induce m6A modification of TRHDE-AS1 in PC cells. Collectively, our results show that propofol prevents PC progression by upregulating TRHDE-AS1 expression and METTL14 is involved in the m6A modification of TRHDE-AS1. These findings suggest that TRHDE-AS1 may be a potential therapeutic target for the improvement of propofol's therapeutic effect.

Preclinical Evaluation of AZD6422, an Armored Chimeric Antigen Receptor T Cell Targeting CLDN18.2 in Gastric, Pancreatic, and Esophageal Cancer.

CLDN18.2 is a surface membrane protein crucial for maintaining tight junctions in gastric mucosal cells and is highly expressed in gastric, esophageal, and pancreatic cancers. Thus, CLDN18.2 is suited for exploration as a clinical target for chimeric antigen receptor T-cell (CAR-T) therapy in these indications. Although CAR-T therapies show promise, a challenge faced in their development for solid tumors is the immunosuppressive tumor microenvironment, often characterized by the presence of immune and stromal cells secreting high levels of transforming growth factor beta (TGF-β). Addition of TGF-β armoring can potentially expand CAR-T activity in solid tumors. We report on the preclinical development of a CLDN18.2-targeting CAR-T showing effectiveness in CLDN18.2-positive gastric, esophageal, and pancreatic tumor models. The lead lentivirus product contains a unique single-chain variable fragment, CD28 and CD3z costimulatory and signaling domains, and dominant negative TGF-β receptor armoring, enhancing targeting and safety and counteracting suppression. We developed a shortened cell manufacturing process to enhance the potency of the final product, AZD6422. AZD6422 exhibited significant antitumor activity and tolerability in multiple patient-derived tumor xenograft models with various CLDN18.2 and TGF-β levels, as determined by immunohistochemistry. Efficacy of armored CAR-Ts in tumor models with elevated TGF-β was increased in vitro and in vivo. In vitro restimulation assays established greater persistence and cytolytic function of AZD6422 compared with a traditionally manufactured CAR-T. AZD6422 was safe and efficacious in patient-derived, CLDN18.2-positive murine models of gastrointestinal cancers. Our data support further clinical development of AZD6422 for patients with these cancers.

MCPIP1 Elicits a Therapeutic Effect on Cervical Cancer by Facilitating XIAP mRNA Decay via Its Endoribonuclease Activity.

Cervical cancer is the fourth most common malignancy in women globally. Chemotherapies, targeted therapies, and immunotherapies in the treatment of cervical cancer are usually accompanied by effective and adverse effects. Therefore, finding other efficient and accurate molecular targets remains essential to improve the treatment benefits of cervical cancer patients. MCPIP1 (monocyte chemoattractant protein-induced protein 1) is a kind of endonuclease with a CCCH zinc finger domain and a PilT-N-terminal (PIN) domain, and its function in cervical cancer is unknown. We found that MCPIP1 inhibits cell proliferation and promotes cell apoptosis of cervical cancer. Additionally, MCPIP1 suppresses mRNA and protein expression of the apoptotic inhibitor XIAP by decreasing its mRNA stability. Mechanically, MCPIP1 binds to the XIAP mRNA via its CCCH zinc finger domain and degrades the XIAP mRNA via the endonuclease activity coming from its PIN domain. Our study clarifies that MCPIP1 promotes cervical cancer cell apoptosis by suppressing the expression of XIAP, thereby impeding cervical cancer progression. Moreover, targeted delivery of MCPIP1 with engineered Salmonella typhimurium leads to tumor growth retardation in the HeLa xenograft tumor model in mice. Therefore, our study may provide a theoretical basis for formulating clinical treatment strategies for cervical cancer.

Curcumin promotes ferroptosis in hepatocellular carcinoma via upregulation of ACSL4

BackgroundFerroptosis, a novel iron-ion-dependent metabolic cell death mode with lipid peroxides as the main driving substrate, plays an irreplaceable role in the development and preventive treatment of hepatocellular carcinoma. Curcumin has potent pharmacological anti-tumor effects.Aim of the studyWe aimed to evaluate the ex vivo and in vivo cancer inhibitory activity of curcumin and its specific mechanism of action.Materials and MethodsWe used the hepatocellular carcinoma cell lines HepG2 and SMMC7721 to assess the direct inhibition of hepatocellular carcinoma proliferation by curcumin in vitro and a tumor xenograft model to evaluate the in vivo cancer inhibitory effect of curcumin.ResultsIn this study, we found that ferroptosis’s inhibitors specifically reversed the curcumin-induced cell death pattern in HCC. After curcumin intervention, there was a substantial increase in MDA levels and iron ion levels, and a decrease in intracellular GSH levels. Meanwhile, the expression of GPX4 and SLC7A11 was significantly reduced at the protein levels, while ACSL4 and PTGS2 expression was significantly increased.ConclusionsThis study showed that curcumin significantly decreased the proliferation of HCC cells and significantly increased the sensitivity of ferroptosis. These results suggest that ACSL4 is a viable target for curcumin-induced ferroptosis in treating HCC.

Temsirolimus inhibits FSP1 enzyme activity to induce ferroptosis and restrain liver cancer progression.

Ferroptosis is a non-apoptotic mode of cell death characterized by iron-dependent accumulation of lipid peroxidation. While lipid radical elimination reaction catalyzed by glutathione peroxidase 4 (GPX4) is a major anti-ferroptosis mechanism, inhibiting this pathway pharmaceutically shows promise as an anti-tumor strategy. However, certain tumor cells exhibit redundancy in lipid radical elimination pathways, rendering them unresponsive to GPX4 inhibitors. In this study, we conducted screens across different cancer cell lines and FDA-approved drugs, leading to the identification of temsirolimus in combination with the GPX4 inhibitor RSL3 as a potent inducer of ferroptosis in liver cancer cells. Mechanistically, temsirolimus sensitized liver cancer cells to ferroptosis by directly binding to and inhibiting ferroptosis suppressor protein 1 (FSP1) enzyme. Notably, while temsirolimus is recognized as a potent mTOR inhibitor, its ferroptosis-inducing effect is primarily attributed to its inhibition of FSP1 rather than mTOR activity. By performing in vitro colony formation assays and in vivo tumor xenograft models, we demonstrated that the combination of temsirolimus and RSL3 effectively suppressed liver tumor progression. This tumoricidal effect was associated with increased lipid peroxidation and induction of ferroptosis. In conclusion, our findings underscore the potential of combining multi-target ferroptosis-inducing agents to circumvent resistance to ferroptosis in liver cancer cells and highlight temsirolimus as a promising FSP1 inhibitor and ferroptosis inducer, which also deserves further investigation in translational medicine.

Abstract C105: Novel cancer-specific hypoxia signature predicts poor prognosis and highlights racial disparities in breast cancer

Abstract Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. TNBC displays exceptional transcriptional heterogeneity, both between patients and intratumorally, and disproportionately affects underserved women. Hypoxia, a state of low oxygen levels, is often present in the solid tumor microenvironment. In TNBC, hypoxia is a key driver of aggressiveness and therapeutic resistance. Past bulk RNA sequencing (RNAseq) studies in cancer research have lacked spatial resolution, failing to uncover precise transcriptional differences within tumor regions. This spatial limitation has been especially problematic for studying transcriptional heterogeneity of the cellular hypoxia response within tumors. By integrating single-cell RNA sequencing and spatial transcriptomic analyses in a TNBC xenograft tumor model, our research has uncovered a novel hypoxia gene signature, specific to cancer cells. Elevated expression of this hypoxia signature predicts poorer prognosis in breast cancer patients, especially within TNBC patients and those of African ancestry. This suggests that hypoxia may play a role in the racial disparities observed in TNBC prognosis, potentially informing treatment strategies. This workflow introduces a novel framework for translating general spatial transcriptomics data into clinically relevant and accurate gene signatures. Citation Format: Kent Schechter, Long C. Nguyen, Geetha P. Yerradoddi, Rania Bassiouni, John D. Carpten, Marsha R. Rosner. Novel cancer-specific hypoxia signature predicts poor prognosis and highlights racial disparities in breast cancer [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C105.

KDM4A promotes malignant progression of breast cancer by down-regulating BMP9 inducing consequent enhancement of glutamine metabolism

BackgroundRecent studies have found that histone-modified genes play an increasingly important role in tumor progression. Lysine(K) specific demethylase 4A (KDM4A) is a histone lysine-specific demethylase highly expressed in a variety of malignant tumors, data showed that KDM4A was negatively correlated with the Bone Morphogenetic Protein 9 (BMP9) in breast cancer. And previous experiments have demonstrated that exogenous BMP9 significantly inhibits breast cancer development.Materials and methodsWe detected the expression of KDM4A in breast cancer and the relationship between KDM4A and BMP9 using real-time quantitative PCR (RT-qPCR) and Western blot, and verified the interaction between KDM4A and BMP9 by ChIP experiments. At the same time, we also detected whether KDM4A had effects on the RNA and protein stability of BMP9 using actinomycin D and cycloheximide. Measurement of alpha-ketoglutarate (α-KG) level by ELISA to observe the effect of BMP9 on glutamine metabolism in breast cancer cells. Nucleoplasmic distribution of KDM4A after exogenous BMP9 treatment in breast cancer cells were observed by immunofluorescence staining and Western blot. A subcutaneous xenograft tumor model in nude mice was used to study the therapeutic effects of exogenous BMP9 and KDM4A inhibitor (JIB-04) in breast cancer. CCK-8, conoly formation, Transwell, wound healing, and immunohistochemistry were used to monitor the growth of tumor and cell function.ResultsWe found that KDM4A was abnormally highly expressed in breast cancer, and silenced BMP9 expression by removing histone methyl groups from the BMP9 gene region. Meanwhile, KDM4A could also reduce the stability of BMP9 protein. BMP9 inhibit glutamine metabolism in breast cancer, resulting in a decrease in its product α-KG, is confirmed by ELISA. Altered nucleoplasmic distribution of KDM4A due to decreased α-KG was confirmed by immunofluorescence staining and Western blot. Animal experiments confirm that the combination of exogenous BMP9 and JIB-04 shows significantly better results in breast cancer.ConclusionsKDM4A silences BMP9 expression by removing histone methyl groups from the BMP9 gene region, leading to further enhancement of glutamine metabolism, which contributes to malignant tumor progression. In addition, using JIB-04 in combination with exogenous BMP9 could inhibit the malignant progression of breast cancer cells and the growth of tumors more significantly.

HOXA9 promotes proliferation, metastasis and prevents apoptosis in hepatocellular carcinoma

PurposeThis research aimed to evaluate the expression level of Homeobox A9 (HOXA9) and its role in tumorigenesis of hepatocellular carcinoma (HCC).MethodsBioinformatic analysis, qPCR and Western blot analysis of clinical samples were employed to evaluate mRNA and protein levels of HOXA9 in HCC patients and cell lines. In vitro cell proliferation, migration and invasion, cloning formation, xenograft tumor model, wound healing and apoptosis assays, RNA sequencing analysis of RPL38-silenced HCC-LM3 cells and qPCR, Western blot analysis were performed for validation. Analysis of HOXA9-related genes were conducted to identify their relationships between HOXA9.ResultsHOXA9 is dramatically upregulated in HCC. Upregulation of HOXA9 in HCC predicts poor survival of patients. Besides, HOXA9 promotes proliferation, metastasis and prevents apoptosis in HCC in vitro. In addition, HOXA9 controlled by Ribosomal protein RPL38 is upregulated in HCC. Bioinformatic analysis also indicated that HOXA9 is involved in the regulation of DNA methylation and immune infiltration in HCC.ConclusionHOXA9 is dramatically upregulated in hepatocellular carcinoma and predicts poor prognosis. Besides, HOXA9 promoted proliferation and metastasis and prevented apoptosis in vitro, which is regulated by Ribosomal protein RPL38 in HCC.

Highly Efficient Synergistic Chemotherapy and Magnetic Resonance Imaging for Targeted Ovarian Cancer Therapy Using Hyaluronic Acid-Coated Coordination Polymer Nanoparticles.

The diagnosis and treatment of ovarian cancer (OC) are still a grand challenge, more than 70% of patients are diagnosed at an advanced stage with a dismal prognosis. Magnetic resonance imaging (MRI) has shown superior results to other examinations in preoperative assessment, while cisplatin-based chemotherapy is the first-line treatment for OC. However, few previous studies have brought together the two rapidly expanding fields. Here a technique is presented using cisplatin prodrug (Pt-COOH), Fe3+, and natural polyphenols (Gossypol) to construct the nanoparticles (HA@PFG NPs) that have a stable structure, controllable drug release behavior, and high drug loading capacity. The acidic pH values in tumor sites facilitate the release of Fe3+, Pt-COOH, and Gossypol from HA@PFG NPs. Pt-COOH with GSH consumption and cisplatin-basedchemotherapy plus Gossypol with pro-apoptotic effects displays asynergisticeffect forkillingtumorcells. Furthermore, the release of Fe3+ at the tumor sites promotes ferroptosis and enables MRI imaging of OC. Inthe patient-derived tumor xenograft (PDX)model, HA@PFG NPs alleviate the tumor activity. RNA sequencing analysis reveals that HA@PFG NPs ameliorate OC symptoms mainly through IL-6 signal pathways. This work combines MRI imaging with cisplatin-based chemotherapy, which holds great promise for OC diagnosis and synergistic therapy.

Characterizing the Cell-Free Transcriptome in a Humanized Diffuse Large B-Cell Lymphoma Patient-Derived Tumor Xenograft Model for RNA-Based Liquid Biopsy in a Preclinical Setting.

The potential of RNA-based liquid biopsy is increasingly being recognized in diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin's lymphoma. This study explores the cell-free transcriptome in a humanized DLBCL patient-derived tumor xenograft (PDTX) model. Blood plasma samples (n = 171) derived from a DLBCL PDTX model, including 27 humanized (HIS) PDTX, 8 HIS non-PDTX, and 21 non-HIS PDTX non-obese diabetic (NOD)-scid IL2Rgnull (NSG) mice were collected during humanization, xenografting, treatment, and sacrifice. The mice were treated with either rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), CD20-targeted human IFNα2-based AcTaferon combined with CHOP (huCD20-Fc-AFN-CHOP), or phosphate-buffered saline (PBS). RNA was extracted using the miRNeasy serum/plasma kit and sequenced on the NovaSeq 6000 platform. RNA sequencing data of the formalin-fixed paraffin-embedded (FFPE) tissue and blood plasma samples of the original patient were included. Flow cytometry was performed on immune cells isolated from whole blood, spleen, and bone marrow. Bulk deconvolution was performed using the Tabula Sapiens v1 basis matrix. Both R-CHOP and huCD20-Fc-AFN-CHOP were able to control tumor growth in most mice. Xenograft tumor volume was strongly associated with circulating tumor RNA (ctRNA) concentration (p < 0.001, R = 0.89), as well as with the number of detected human genes (p < 0.001, R = 0.79). Abundance analysis identified tumor-specific biomarkers that were dynamically tracked during tumor growth or treatment. An 8-gene signature demonstrated high accuracy for assessing therapy response (AUC 0.92). The tumoral gene detectability in the ctRNA of the PDTX-derived plasma was associated with RNA abundance levels in the patient's tumor tissue and blood plasma (p < 0.001), confirming that tumoral gene abundance contributes to the cell-free RNA (cfRNA) profile. Decomposing the transcriptome, however, revealed high inter- and intra-mouse variability, which was lower in the HIS PDTX mice, indicating an impact of human engraftment on the stability and profile of cfRNA. Immunochemotherapy resulted in B cell depletion, and tumor clearance was reflected by a decrease in the fraction of human CD45+ cells. Lastly, bulk deconvolution provided complementary biological insights into the composition of the tumor and circulating immune system. In conclusion, the blood plasma-derived transcriptome serves as a biomarker source in a preclinical PDTX model, enables the assessment of biological pathways, and enhances the understanding of cfRNA dynamics.

Inhibition of Colorectal Cancer Metastasis by Total Flavones of Abelmoschus Manihot via Lncrna AL137782-mediated STAT3/EMT Pathway Regulation.

Colorectal cancer (CRC) ranks among the most lethal malignancies globally, particularly following metastasis which results in poor prognosis. In recent years, CRC incidence in China has persistently increased. Total flavonoids (TFA) from Abelmoschus manihot, a natural compound, are recognized for their anti-inflammatory, analgesic, and antioxidant properties. However, despite extensive research into the therapeutic potential of TFA, coverage of its role in cancer treatment is notably lacking. To address this research void, our study aims to unveil the role and potential mechanisms of TFA in treating CRC. We conducted a series of experiments to assess the impact of TFA on CRC cells. Two specific CRC cell lines, DLD-1 and HCT116, were employed in cell proliferation, colony formation, flow cytometry, and cell migration assays. Additionally, to test the in vivo effects of TFA, we developed a nude mouse xenograft tumor model to assess TFA's impact on tumor growth and liver metastasis. Furthermore, we meticulously analyzed the gene expression differences between CRC cells pretreated with TGF-β and those treated with TFA using RNA-seq technology. We also examined the molecular mechanisms of TFA and assessed the expression of proteins related to the STAT3/EMT signaling pathway through Western blotting and siRNA technology. Our research findings reveal for the first time the effect of TFA on CRC cells. Result shows that TFA could suppress cell proliferation, migration, and induce apoptosis. In vivo results showed that TFA inhibited tumor growth and liver metastasis. Molecular mechanism studies have shown that TFA exerts these effects by upregulating the expression of non-coding RNA AL137782, inhibiting the EMT/STAT3 signaling pathway. These results suggest that TFA is a potential candidate for mitigating CRC metastasis. However, further research is needed to comprehensively evaluate the efficacy and safety of TFA in animal models and clinical settings. These findings bring great hope for the development of innovative CRC treatment methods.

LncRNA HAND2-AS1 Inhibited Colon Cancer Progression By Regulating miR-3118/ZG16 Axis.

LncRNA HAND2-AS1 is a novel cancer regulator, but the role and mechanisms of HAND2-AS1 involved with colon cancer (CC) progression remains unknown. The purpose of this research was to figure out how HAND2-AS1 regulates the progression of CC. Using qRT-PCR, we studied expression levels of miR-3118, HAND2-AS1, and ZG16 in CC tissues and cells. Protein levels of apoptosis-related proteins (Bax and Bcl-2) and ZG16 were quantified by western blotting. In vitro function analysis referred to western blotting, wound healing assay and CCK-8. The binding association among miR-3118, HAND2-AS1, and ZG16 was investigated using luciferase reporter and RIP assays. The functional role of HAND2-AS1 was analyzed using xenograft tumor models in vivo. In tissues and cells of CC, HAND2-AS1 was downregulated. We observed that HAND2-AS1 overexpression declined CC cell proliferation and migration while facilitating apoptosis. We further verified that when HAND2-AS1 is overexpressed it reduced CC tumor development in vivo. In CC cells and tissues, miR-3118 competed with HAND2-AS1 and was elevated. Further it was noted that the HAND2-AS1 when overexpressed, lessened the survival of CC cells, however overexpression of miR-3118 restored these changes. ZG16 was shown to be a target of miR-3118, it was found that ZG16 was downregulated in CC tissue and cells. We observed, high expression of ZG16 partially restored the enhanced malignant phenotype caused by miR-3118 overexpression. HAND2-AS1 inhibited CC progression by upregulating ZG16 expression through sponging miR-3118. Hence, HAND2-AS1/miR-3118/ZG16 axis could be a possible new target for CC treatment.

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.

Dronedarone inhibits the proliferation of esophageal squamous cell carcinoma through the CDK4/CDK6-RB1 axis in vitro and in vivo.

Treatment options for patients with esophageal squamous cell carcinoma (ESCC) often result in poor prognosis and declining health-related quality of life. Screening FDA-approved drugs for cancer chemoprevention is a promising and cost-efficient strategy. Here, we found that dronedarone, an antiarrhythmic drug, could inhibit the proliferation of ESCC cells. Moreover, we conducted phosphorylomics analysis to investigate the mechanism of dronedarone-treated ESCC cells. Through computational docking models and pull-down assays, we demonstrated that dronedarone could directly bind to CDK4 and CDK6 kinases. We also proved that dronedarone effectively inhibited ESCC proliferation by targeting CDK4/CDK6 and blocking the G0/G1 phase through RB1 phosphorylation inhibition by in vitro kinase assays and cell cycle assays. Subsequently, we found that knocking out CDK4 and CDK6 decreased the susceptibility of ESCC cells to dronedarone. Furthermore, dronedarone suppressed the growth of ESCC in patient-derived tumor xenograft models in vivo. Thus, our study demonstrated that dronedarone could be repurposed as a CDK4/6 inhibitor for ESCC chemoprevention.

METTL3-Mediated m6A Modification of FMRP Drives Hepatocellular Carcinoma Progression and Indicates Poor Prognosis.

Accumulating studies reveal that m6A RNA methylation plays a critical role in cancer pathogenesis and progression. METTL3 as a m6A methyltransferase acts as an oncogene in multiple malignancies including hepatocellular carcinoma (HCC). However, the role and underlying mechanism by which METTL3 contributes to HCC remain unclear. The association of METTL3 expression with clinicopathological characteristics and prognosis in patients with HCC was assessed by reverse transcription polymerase chain reaction, Western blot, and public TCGA dataset. MTT, colony formation, Transwell assays, and xenograft tumor models were executed to reveal the role of METTL3 in HCC. m6A dot blot, RNA immunoprecipitation (RIP), m6A methylated RIP, and Western blot assays were used to uncover the regulatory mechanism of METTL3 in HCC cells. We found that METTL3 was dramatically upregulated in HCC tissue samples and acted as an independent prognostic factor for poor survival and tumor recurrence in patients with HCC. Silencing of METTL3 repressed cell growth and invasion in vitro and invivo, but restored expression of METTL3 boosted these effects. Mechanistical investigations revealed that METTL3 could directly interact with FMRP and harbor a positive correlation with FMRP expression. Knockdown of METTL3 reduced FMRP m6A levels as well as its mRNA and protein expression. FMRP overexpression drove cell colony formation and cell invasion and abolished METTL3 knockdown-induced antitumor effects and AKT/mTORC1 signaling inactivation. Elevated expression of FMRP could act as an independent prognostic factor for poor survival and tumor recurrence in patients with HCC. Our findings demonstrate that METTL3-mediated m6A modification of FMRP promotes growth and invasion of HCC cells and may provide a promising therapeutic target for HCC.

LncRNA XIST/miR-455-3p/HOXC4 axis promotes breast cancer development by activating TGF-β/SMAD signaling pathway.

Breast cancer is the second primary cause of cancer death among women. Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is a central regulator for X chromosome inactivation, and its abnormal expression is a primary feature of breast cancer. So far, the mechanism of XIST in breast cancer has not been fully elucidated. We attempted to illustrate the mechanism of XIST in breast cancer. The expressions of XIST, microRNA-455-3p (miR-455-3p) in breast cancer were measured using quantitative real-time PCR. The expressions of homeobox C4 (HOXC4) were assessed with immunohistochemical and Western blot. Also, the functions of XIST in breast cancer were assessed by Cell Counting Kit-8 analysis, colony formation assay, flow cytometry, Western blot, Transwell, and cell scratch assays. Meanwhile, the mechanism of XIST in breast cancer was validated using database analysis and dual-luciferase reporter assay. Furthermore, the function of XIST in breast cancer in vivo was estimated by tumor xenograft model, immunohistochemical assay, and hematoxylin-eosin staining. XIST and HOXC4 expressions were increased, but miR-455-3p expressions were decreased in breast cancer tissues and cells. Knocking down XIST restrained breast cancer cell proliferation, invasion, migration, epithelial-mesenchymal transformation (EMT), and induced cell cycle arrest at G0/G1. Meanwhile, XIST interacted with miR-455-3p, while miR-455-3p interacted with HOXC4. XIST knockdown repressed breast cancer cell proliferation, invasion, and EMT, while miR-455-3p inhibitor or HOXC4 overexpression abolished those impacts. HOXC4 overexpression also blocked the impacts of miR-455-3p mimic on breast cancer cell malignant behavior. In vivo experimental data further indicated that XIST knockdown repressed breast cancer cell tumorigenic ability, and decreased HOXC4 and p-SMAD3 (TGF-β/SMAD-related protein) expressions.XIST/miR-455-3p/HOXC4 facilitated breast cancer development by activating the TGF-β/SMAD pathway.

Inhibition of nucleo-cytoplasmic proteasome translocation by the aromatic amino acids or silencing Sestrin3-their sensing mediator-is tumor suppressive.

The proteasome, the catalytic arm of the ubiquitin system, is regulated via its dynamic compartmentation between the nucleus and the cytoplasm, among other mechanisms. Under amino acid shortage, the proteolytic complex is translocated to the cytoplasm, where it stimulates proteolysis to supplement recycled amino acids for essential protein synthesis. This response ismediated via the mTOR pathway and the lack of the three aromatic amino acids Tyr, Trp, and Phe (YWF). mTOR activation by supplementation of the triad inhibits proteasome translocation, leading to cell death. We now show that tumoral inherent stress conditions result in translocation of the proteasome from the nucleus to the cytosol. We further showthat the modulation of the signaling cascade governed by YWF is applicable also to non-starved cells by using higher concentration of the triad to achieve a surplus relative to all other amino acids. Based on these two phenomena, we found that the modulation of stress signals via the administration of YWF leads to nuclear proteasome sequestration and inhibition of growth of xenograft, spontaneous, and metastatic mouse tumor models. In correlation with the observed effect of YWF on tumors, we found - using transcriptomic and proteomic analyses - that the triad affects various cellular processes related to cell proliferation, migration, and death. In addition, Sestrin3-a mediator of YWF sensing upstream of mTOR-is essential for proteasome translocation, and therefore plays a pro-tumorigenic role, positioning it as a potential oncogene. This newly identified approach for hijacking the cellular "satiety center" carries therefore potential therapeutic implications for cancer.