Proliferation Of Breast Cancer Cells Research Articles

GPR39-mediated ERK1/2 signaling reduces permethrin-induced proliferation of estrogen receptor α-negative cells

Certain insecticides are known to have estrogenic effects by activating estrogen receptors through genomic transcription. This has led researchers to associate specific insecticide use with an increased breast cancer risk. However, it is unclear if estrogen receptor-dependent pathways are the only way in which these compounds induce carcinogenic effects. The objective of this study was to determine the impact of the pyrethroid insecticide permethrin on the growth of estrogen receptor negative breast cancer cells MDA-MB-231. Using tandem mass spectrometric techniques, the effect of permethrin on cellular protein expression was investigated, and gene ontology and pathway function enrichment analyses were performed on the deregulated proteins. Finally, molecular docking simulations of permethrin with the candidate target protein was performed and the functionality of the protein was confirmed through gene knockdown experiments. Our findings demonstrate that exposure to 10–40 μM permethrin for 48 h enhanced cell proliferation and cell cycle progression in MDA-MB-231. We observed deregulated expression in 83 upregulated proteins and 34 downregulated proteins due to permethrin exposure. These deregulated proteins are primarily linked to transmembrane signaling and chemical carcinogenesis. Molecular docking simulations revealed that the overexpressed transmembrane signaling protein, G protein-coupled receptor 39 (GPR39), has the potential to bind to permethrin. Knockdown of GPR39 partially impeded permethrin-induced cellular proliferation and altered the expression of proliferation marker protein PCNA and cell cycle-associated protein cyclin D1 via the ERK1/2 signaling pathway. These findings offer novel evidence for permethrin as an environmental breast cancer risk factor, displaying its potential to impact breast cancer cell proliferation via an estrogen receptor-independent pathway.

Tubulin alpha-1b chain was identified as a prognosis and immune biomarker in pan-cancer combing with experimental validation in breast cancer

The α-tubulin subtype, Tubulin α-1b chain (TUBA1B), has been shown to influence immune cell infiltration, cancer growth, and survival across various malignancies. However, a comprehensive study has not yet been undertaken examining the immunological and predictive effects of TUBA1B in a pan-carcinoma context. Using data from TCGA, GEO, and other databases, we analyzed TUBA1B expression across various carcinoma types using transcriptional profiling, prognostic implications, genetic and epigenetic alterations, methylation patterns, and immunological significance. To validate our findings, we conducted Western blot analysis to assess TUBA1B protein levels in matched breast cancer tissue samples and performed CCK-8 proliferation assay, flow cytometry, transwell invasion, and migration assays to comprehensively examine the functional impact of TUBA1B on breast cancer cells. Our pan-cancer analysis found TUBA1B upregulation across most tumor types, with varying expression patterns in distinct immune and molecular subtypes. High TUBA1B expression was an independent risk factor and associated with poor prognoses in several cancers, including BRCA, KICH, LGG, LUAD, and MESO. TUBA1B also demonstrates moderate to high diagnostic accuracy in most tumor types. Increased m6A methylation levels were observed in the TUBA1B gene, while its promoter region displayed low methylation levels. TUBA1B's expression impacted some cancers by elevating tumor mutation burden, microsatellite instability, neoantigen formation, immune cell infiltration, and the modulation of immune checkpoints. Functional enrichment analysis highlights TUBA1B’s involvement in important cellular processes such as the cell cycle, p53 signaling, cell senescence, programmed cell death, and the regulation of immune-related pathways. Moreover, our study reveals higher TUBA1B protein expression in breast cancer tissues compared to adjacent tissues. In vitro experiments confirm that TUBA1B deletion reduces breast cancer cell proliferation, invasion, and migration while increasing apoptosis. In conclusion, our study suggests that TUBA1B could potentially serve as a diagnostic marker for predicting cancer immunological profiles and survival outcomes and shed light on the expression and role of TUBA1B in breast cancer, providing a solid foundation for considering it as a promising therapeutic target for breast cancer patient treatment.

Retraction Note: TMED3 promotes cell proliferation and motility in breast cancer and is negatively modulated by miR-188-3p

Retraction Note: TMED3 promotes cell proliferation and motility in breast cancer and is negatively modulated by miR-188-3p

Long non‑coding RNA DANCR aggravates breast cancer through the miR‑34c/E2F1 feedback loop.

Emerging scientific evidence has suggested that the long non‑coding (lnc)RNA differentiation antagonizing non‑protein coding RNA (DANCR) serves a significant role in human tumorigenesis and cancer progression; however, the precise mechanism of its function in breast cancer remains to be fully understood. Therefore, the objective of the present study was to manipulate DANCR expression in MCF7 and MDA‑MB‑231 cells using lentiviral vectors to knock down or overexpress DANCR. This manipulation, alongside the analysis of bioinformatics data, was performed to investigate the potential mechanism underlying the role of DANCR in cancer. The mRNA and/or protein expression levels of DANCR, miR‑34c‑5p and E2F transcription factor 1 (E2F1) were assessed using reverse transcription‑quantitative PCR and western blotting, respectively. The interactions between these molecules were validated using chromatin immunoprecipitation and dual‑luciferase reporter assays. Additionally, fluorescence in situ hybridization was used to confirm the subcellular localization of DANCR. Cell proliferation, migration and invasion were determined using 5‑ethynyl‑2'‑deoxyuridine, wound healing and Transwell assays, respectively. The results of the present study demonstrated that DANCR had a regulatory role as a competing endogenous RNA and upregulated the expression of E2F1 by sequestering miR‑34c‑5p in breast cancer cells. Furthermore, E2F1 promoted DANCR transcription by binding to its promoter in breast cancer cells. Notably, the DANCR/miR‑34c‑5p/E2F1 feedback loop enhanced cell proliferation, migration and invasion in breast cancer cells. Thus, these findings suggested that targeting DANCR may potentially provide a promising future therapeutic strategy for breast cancer treatment.

Identification of PTPN12 Phosphatase as a Novel Negative Regulator of Hippo Pathway Effectors YAP/TAZ in Breast Cancer.

The Hippo pathway plays crucial roles in governing various biological processes during tumorigenesis and metastasis. Within this pathway, upstream signaling stimuli activate a core kinase cascade, involving MST1/2 and LATS1/2, that subsequently phosphorylates and inhibits the transcriptional co-activators YAP and its paralog TAZ. This inhibition modulates the transcriptional regulation of downstream target genes, impacting cell proliferation, migration, and death. Despite the acknowledged significance of protein kinases in the Hippo pathway, the regulatory influence of protein phosphatases remains largely unexplored. In this study, we conducted the first gain-of-functional screen for protein tyrosine phosphatases (PTPs) regulating the Hippo pathway. Utilizing a LATS kinase biosensor (LATS-BS), a YAP/TAZ activity reporter (STBS-Luc), and a comprehensive PTP library, we identified numerous novel PTPs that play regulatory roles in the Hippo pathway. Subsequent experiments validated PTPN12, a master regulator of oncogenic receptor tyrosine kinases (RTKs), as a previously unrecognized negative regulator of the Hippo pathway effectors, oncogenic YAP/TAZ, influencing breast cancer cell proliferation and migration. In summary, our findings offer valuable insights into the roles of PTPs in the Hippo signaling pathway, significantly contributing to our understanding of breast cancer biology and potential therapeutic strategies.

N-Substituted dihydropyridines as promising EGFR tyrosine kinase inhibitors against breast cancer: Design, synthesis, biological evaluation, docking, and molecular dynamics simulations

Breast cancer is a major health concern, chemotherapy and radiotherapy face ongoing challenges due to drug resistance and toxicity. EGFR is a key driver of tumorigenesis, and its amplification or mutation is common in breast cancer. Tyrosine kinase inhibitors (TKIs), such as erlotinib and lapatinib, inhibit the EGFR pathway by competitively binding to the adenosine triphosphate pocket of EGFR. The Hantzsch reaction is a versatile method for synthesizing dihydropyridine derivatives that exhibit a range of pharmacological effects. This study aims for the molecular design, synthesis, analysis, and biological screening of N-Substituted Hantzsch dihydropyridines for their potential as EGFR inhibitors. The results showed that synthesized compounds inhibited the proliferation of MCF-7 breast cancer cells and modulated the expression of genes involved in the PI3K/Akt signaling pathway, which is downstream events of EGFR. Among all the synthesized compounds, NHD-3, NHD-4, and NHD-5 displayed the most potent inhibitory activity against MCF-7 cells with IC50 value of 17.24 ± 1.23, 10.92 ± 1.03, and 07.34 ± 0.86 µM, respectively. The potent dihydropyridines derivatives were also screened for EGFRwt inhibition assay and among the three compounds tested, NHD-5 showed reasonably good inhibitory activity with an IC50 value of 20.10 ± 1.30 nM compared to a Lapatinib with IC50 value of 10.28 ± 1.01 nM. Molecular docking and molecular dynamics simulations were performed to provide insight into the binding modes, interactions, and stability of these compounds with EGFR

A novel long non-coding RNA LINC00524 facilitates invasion and metastasis through interaction with TDP43 in breast cancer.

Breast cancer (BC) remains a significant health concern worldwide, with metastasis being a primary contributor to patient mortality. While advances in understanding the disease's progression continue, the underlying mechanisms, particularly the roles of long non-coding RNAs (lncRNAs), are not fully deciphered. In this study, we examined the influence of the lncRNA LINC00524 on BC invasion and metastasis. Through meticulous analyses of TCGA and GEO data sets, we observed a conspicuous elevation of LINC00524 expression in BC tissues. This increased expression correlated strongly with a poorer prognosis for BC patients. A detailed Gene Ontology analysis suggested that LINC00524 likely exerts its effects through RNA-binding proteins (RBPs) mechanisms. Experimentally, LINC00524 was demonstrated to amplify BC cell migration, invasion and proliferation invitro. Additionally, invivo tests showed its potent role in promoting BC cell growth and metastasis. A pivotal discovery was LINC00524's interaction with TDP43, which leads to the stabilization of TDP43 protein expression, an element associated with unfavourable BC outcomes. In essence, our comprehensive study illuminates how LINC00524 accelerates BC invasion and metastasis by binding to TDP43, presenting potential avenues for therapeutic interventions.

Ginsenoside Re Suppress the Proliferation and Migration of MCF-7 Human Breast Cancer Cells

Ginsenoside Re Suppress the Proliferation and Migration of MCF-7 Human Breast Cancer Cells

RBP7 functions as a tumor suppressor in HR + breast cancer by inhibiting the AKT/SREBP1 pathway and reducing fatty acid

BackgroundIncreasing evidence proves that RBP7 plays a significant role in breast cancer (BC). The present study was aimed to investigate the mechanism of RBP7.MethodsWestern Blotting and qRT-PCR were performed for evaluating the expression levels. CCK8, colony forming, xenograft mouse model, wound healing and transwell assays were conducted to examine cell ability of proliferation, invasion and migration. Nile red staining and Oil red O staining were used for testing the lipid.ResultsRBP7 was related to overall survival (OS) in patients with HR + BC. RBP7 protein was significantly decreased in HR + BC tissues and cells. RBP7 suppressed HR + BC cell proliferation in vitro and in vivo, and inhibited migration and invasion. RBP7 reduced fatty acid in HR + BC cells by inhibiting the AKT/SREBP1 pathway.ConclusionsRBP7 may function as a tumor suppressor in HR + BC by inhibiting the AKT/SREBP1 pathway and reducing fatty acid.

Abstract 1510: Cell-cell contacts regulate HER2 cellular localization and the transitions between migration and proliferation in breast cancer cells

Abstract Introduction: Epithelial-to-mesenchymal transition (EMT) is widely recognized as the primary mechanism regulating invasion and metastatic dissemination in carcinomas. In contrast, the mechanisms triggering single disseminated cancer cells (DCC) to reacquire their epithelial identity at ectopic sites, initiating metastasis formation, remain unclear. Since we had previously noted that HER2 expression levels and cellular density impact on migration and proliferation, we sought to determine whether they are involved in molecular mechanisms regulating transitions between proliferation and migration. Methods: To control HER2 expression levels we generated inducible cell models. Cell density was assessed by the number of cell-cell contacts or by the number of cells per area. Pathway analyses were performed by gene expression analysis, protein interactions by western blotting and mass spectrometry. Migration and proliferation were analyzed by functional assays including in vitro live cell imaging. Results: Migrating epithelial cells undergo reduced protein trafficking, resulting in a perinuclear deposition of HER2. This was accompanied by increased calcium ion regulation via phospholipase-C in the endoplasmic reticulum (ER). Upon the establishment of cell-cell contacts, particularly between cells expressing desmosome cadherin proteins, HER2 is redirected to the cell surface through direct physical binding with desmoplakin, facilitating proliferation signals. Then, PIP2 to PIP3 is converted through the activation of the PI3K pathway, concomitant with the upregulation of PDPK1. The PH domain of PDPK1 exhibits a high binding affinity to PIP2 molecules. Consequently, membrane localization of HER2 significantly diminishes PIP2 availability for the PLC pathway, redirecting cells towards proliferation. Patient sample analysis confirmed the loss of membrane-bound HER2 in solitary circulating tumor cells (CTCs), which was paralleled by increased plakoglobin, elevated ZEB1, and reduced KI67 protein levels. Conclusion: Cell-cell contacts determine the cellular localization and function of growth factor receptors like HER2. Single disseminating cancer cells therefore need to establish such contacts at metastatic sites to activate proliferation programs. Our data are in line with findings that circulating tumor cell clusters are associated with higher metastatic rates, the impact of specific metastatic niches for outgrowth and have implementation for the targeting of single DCC. Citation Format: Hedayatollah Hosseini, Saba Sameri, Shabnam Shahrivari, Carolina Fisch, Miriam Kokal, Michael Schletter, Paul Sylvester Hahn, Lisa Seider, Marisa Schübel, Durdam Das, Martin Hoffmann, Christian Werno, Kathrin Weidele, Vladan Milosevic, Arne Östman, Shamim Sarhadi, Joachim Wegener, Stefanie Michaelis, Florian Weber, Astrid Bruckmann, Ernst R. Tamm, Yuting Li, Christoph A. Klein. Cell-cell contacts regulate HER2 cellular localization and the transitions between migration and proliferation in breast cancer cells [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 1510.

Abstract 294: The HOXB7 protein promotes breast cancer cell growth through activation of the CCL5/CCR5 pathway in the crosstalk of adipocyte

Abstract Homeobox genes are regulatory genes that encode nuclear proteins acting as transcription factors during normal development and differentiation. One such gene, HOXB7, plays a role in various developmental processes, including hematopoietic differentiation, lymphoid development, and mammary gland development. However, the role of HOX genes in breast cancer development remains largely unexplored. Our previous studies revealed that HOXB7 expression was significantly elevated in primary cancer and distant metastasis. HOXB7 overexpression promoted cell proliferation in SKBR3 breast cancer cells, leading to robustly vascularized xenografts in immunodeficient mice. Furthermore, HOXB7 enhanced tumor growth through TGF beta signaling and recruitment of macrophages, indicating the role of HOXB7 in the crosstalk of stromal components. We found evidence that HOXB7 overexpression in ER+ breast cancer cells promotes tumor cell growth through increased expression and signaling of CCL5/CCR5 in crosstalk with adipocytes. By screening secreted factors in adipocytes induced by TCM of MCF-7-HOXB7 cells, it was also found that CCL5 is highly expressed in HOXB7-overexpressing MCF-7 cells. The CCR5 inhibitor, maraviroc, sensitized MCF-7-HOXB7 cells compared to control cells. These findings suggest that blocking the interaction between CCL5 and CCR5 signaling significantly inhibits ER+ breast cancer with HOXB7 overexpression. We aim to further investigate if HOXB7 overexpression in ER+ breast cancer cells promotes tumor cell growth through increased expression and signaling of CCL5/CCR5 in crosstalk with adipocytes and the role of CCL5 in breast cancer cell growth and migration. Citation Format: Ahone Gina Akume, Kideok Jin. The HOXB7 protein promotes breast cancer cell growth through activation of the CCL5/CCR5 pathway in the crosstalk of adipocyte [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 294.

Abstract 200: OA inhibits the development of breast cancer through K1108 acetylation of Zeb1

Abstract Background:Olive oil has long been considered a healthier edible oil, rich in 75% oleic acid (OA) as its main component. OA is a monounsaturated fatty acid, and recent studies have shown that it is no longer limited to protecting cardiovascular and cerebrovascular systems, but can also reduce the risk of cancer. However, there is limited research on the specific mechanism. After fatty acid is ingested into the body, through fatty acids β-oxidation produces acetyl-CoA, which is a donor of protein acetylation. EMT is an important process to regulate tumor metastasis, and Zeb1 is one of the important EMT transcription factors. Therefore, we explored whether OA could inhibit the progress of breast cancer by affecting the acetylation modification of Zeb1. Methods: Western blotting, CCK8 assay, and Transwell were used to test the impact of gradient doses of OA on breast cancer cells. Immunoprecipitation and Immunoprecipitation mass spectrum were used to determine the acetylation modification sites of Zeb1. Coimmunoprecipitation, IF, and pull-down were used to test and verify the acetylase and deacetylase of Zeb1. Knockdown endogenous ZEB1 and then reconstructed stable cell lines of Zeb1 wild-type (Zeb1K1108WT), acetylation activated (Zeb1K1108Q), and inactivated mutants (Zeb1K1108R) by lentivirus. Detection of Zeb1 acetylation in patient tissue samples and mouse models under OA treatment using Zeb1-specific acetylation-modified antibodies. Results: OA inhibits the proliferation and migration of breast cancer cells in a concentration gradient-dependent manner, and inhibits the expression of Zeb1, N Cadherin, and upregulates E Cadherin. Among numerous fatty acids, only OA can promote the acetylation of Zeb1 by adjusting the ratio of acetyl-CoA and NAD+/NADH. K1108 is a biologically functional acetylation site of Zeb1, Zeb1K1108R exerts the cancer promoting function of Zeb1, while Zeb1K1108Q does not. OA can promote acetylation of Zeb1K1108WT, but cannot promote acetylation of Zeb1K1108R. Conclusions: OA inhibits the development of breast cancer through K1108 acetylation of Zeb1. These results suggest that breast cancer may be ameliorated through dietary interventions. Citation Format: Min Guo, Yanjin Wang, Yi Shi, Shuang Yang. OA inhibits the development of breast cancer through K1108 acetylation of Zeb1 [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 200.

Abstract 2994: MIR99AHG promotes ERα expression and ER-positive breast cancer cells proliferation via activating Hippo signaling

Abstract Background: Estrogen receptor (ER) positive breast cancer is the most common subtype of breast cancer. Elucidation of the regulatory network in estrogen receptor pathway is critical to develop and deliver potent targeted therapy for ER-positive breast cancer. The Mir-99a-let-7c cluster host gene MIR99AHG is a long non-coding RNA involving in a variety of tumor formation and disease progression processes. However, the biological functions of MIR99AHG in ER-positive breast cancer have not been reported. Methods: The Western-blot, qRT-PCR, Immunofluorescence and fluorescence in-situ hybridization were used to identify potential target genes and regulatory pathway of estrogen receptor α (ERa), which is a key proliferative driver of ER-positive breast cancer cells. The cell proliferation assay, clone formation assay, xenograft tumor model and rescue assay were used to investigate the effect of differential expression of MIR99AHG on the proliferative capacity of ER-positive breast cancer cells MCF7 and T47D. In addition, correlation analysis was performed to verify the relation of the expression of MIR99AHG, LATS1, LATS2, CYR61, CTGF and ESR1 from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) cohorts. And survival analysis was used to predict the prognostic impact of MIR99AHG in breast cancer patients. Results: MIR99AHG expression was significantly higher in ER-positive breast cancer cells MCF7 and T47D than in ER-negative breast cancer cells SKBR3, MDA-MB-231 and BT549. The high expression of MIR99AHG predicted poor prognosis in ER-positive breast cancer patients. In vitro and in vivo assays demonstrated that MIR99AHG positively regulated the proliferation of MCF7 and T47D cells. Importantly, the Hippo signaling was identified to be down-stream mediators of MIR99AHG in modulating ERα transcription. Furthermore, XMU-MP-1, which targets the Hippo signaling upstream kinase MST1/2, was able to reverse the effect of MIR99AHG on MCF7 cell proliferation. Conclusions: MIR99AHG up-regulates ERα expression and promotes proliferation in ER-positive breast cancer cells through activating Hippo signaling pathway. Targeting MIR99AHG/Hippo pathway is a potential strategy for the treatment of ER-positive breast cancer. Citation Format: Wende Wang, Danping Lin, Ziyang Lin, Yangyang Yan, Yusen Qin, Yuanke Liang, Haoyu Lin, De Zeng. MIR99AHG promotes ERα expression and ER-positive breast cancer cells proliferation via activating Hippo signaling [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 2994.

Abstract 6772: A 3D model of breast cancer-bone metastasis to mimic dysregulation of bone remodeling and drug response

Abstract Introduction: Bone metastases are common among advanced stage breast cancer patients and induce dysregulation of bone remodeling. Crosstalk between cancer cells and the bone niche drives the vicious cycle of bone loss and breast cancer growth. To accelerate discovery of targeted therapies, there is a critical need for experimental models that can mimic breast cancer-induced dysregulation of bone remodeling in patients. Mouse models are the current gold standard, but are low throughput, costly, and cannot fully recapitulate human-human cell interactions. To address these limitations, our goal is to engineer a fully human 3D in vitro model of breast cancer-bone metastasis that can mimic dysregulation of bone remodeling and drug responses in patients, and enable screening of potential new drug candidates. Methods: Two human breast cancer cell lines (MDA-MB-231, MCF-7) were chosen given their well characterized clinical features and tendency to invade bone. Our 3D model comprises an outer ring of tissue engineered (TE) bone and a center of breast cancer cells to mimic invasion through the bone marrow/long bone interface. Human mesenchymal stem cells were encapsulated in 3D gelatin microribbon scaffolds and cultured in osteogenic media for 28 days to form TE bone. Human monocyte-derived osteoclasts were seeded onto the bone, and the center was replaced with GFP-labeled breast cancer cells. Denosumab and zoledronic acid were selected as they are standard treatments for reducing bone loss in patients, and were used to treat the model at 30 µg/mL and 2 µg/mL, respectively. Intermittent parathyroid hormone (iPTH) treatment was selected as it showed efficacy in animal models, and was used to treat the model at 10 µg/mL for 6 hours daily. All groups were treated with drugs for 14 days. Bone volume was assessed using microCT. Cancer cell proliferation and invasion into bone was monitored with fluorescence confocal microscopy. Results: MicroCT imaging showed both breast cancer cell lines induced bone loss in the triculture model, compared to the control with no breast cancer cells in the center. Consistent with known clinical features, the more aggressive cell line (MDA-MB-231) induced a greater amount of bone loss than the less aggressive breast cancer cell line (MCF-7). Consistent with clinical findings, both denosumab and zoledronic acid reduced bone loss in our 3D model, and zoledronic acid further reduced breast cancer cell invasion and proliferation. Finally, the 3D model recapitulated the in vivo drug response of iPTH treatment, reducing bone resorption and breast cancer invasion. Conclusions: Here we report a fully human triculture model of breast cancer-bone metastasis that can mimic key clinical features of breast cancer-induced bone resorption and drug response in patients. Such a 3D model could enable screening of drug candidates with reduced time and cost and enable identification of novel druggable targets. Citation Format: Michelle Tai, Eva C. González Díaz, Callan E. Monette, Joy Wu, Fan Yang. A 3D model of breast cancer-bone metastasis to mimic dysregulation of bone remodeling and drug response [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 6772.

Abstract 437: Hydrogen sulfide switches the glucose metabolism through sulfhydration on pyruvate kinase M2

Abstract Cancer cells reprogram their glucose metabolism from oxidative phosphorylation to aerobic glycolysis. This metabolic transformation is partly based on the activity alterations of a rate limiting enzyme known as the pyruvate kinase M2 (PKM2), which is responsible for the conversion of phosphoenolpyruvate (PEP) into pyruvate. Attributed to its critical regulatory role. PKM2 is recognized as the pivotal enzyme in cancer glucose metabolism By reducing the enzyme activity of PKM2, cancer cells attain a greater fraction of glycolytic metabolites for macromolecule synthesis needed for rapid proliferation. Hydrogen sulfide (H2S), an endogenously produced gasotransmitter that acts as a critical mediator in multiple physiological processes, modifies proteins mainly through the persulfide (-SSH) bond formation, which is called sulfhydration. Our preliminary study demonstrates that H2S stimulates PKM2 sulfhydration at multiple cysteine residues, including cysteine 326, leading to the destabilization of active tetrameric PKM2 form into dimers or monomers. The PKM2 dimer/monomer further translocates into the nucleus to simulate the activation of glycolytic related genes. Blocking PKM2 sulfhydration at cysteine 326 through amino acid mutation stabilizes PKM2 tetramer and crystal structure further indicates that the tetramer organization of PKM2C326S is different from the currently known T or R states, revealing PKM2C326S as a newly identified intermediate form. Blocking PKM2 sulfhydration at cysteine 326 inhibited cell proliferation and tumor growth in xenograft mouse model. In summary, our current study illustrates that H2S-mediated sulfhydration induces the dissociation of the PKM2 tetramer, resulting in the reduced PKM2 activity and subsequently inhibits breast cancer cell proliferation and tumor growth. Targeting the sulfhydration site of PKM2 emerges as a promising therapeutic target specific for cancer metabolism. Citation Format: Po-Chen Chien, Rong-Hsuan Wang, Pin-Ru Chen, Yue-Ting Chen, Yi-Chang Chen, Yu-Hsin Chu, Chia-Chen Chien, Shao-Yun Lo, Zhong-Liang Wang, Min-Chen Tsou, Ssu-Yu Chen, Guang-Shen Chiu, Wen-Ling Chen, Yi-Hsuan Wu, Hui-Ching Wang, Shu-Yi Lin, Wen-Ching Wang, Hsing-Jien Kung, Lu-Hai Wang, Hui-Chun Cheng, Kai-Ti Lin. Hydrogen sulfide switches the glucose metabolism through sulfhydration on pyruvate kinase M2 [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 437.

Abstract 7220: Emerging combination strategy: FANCI suppression induces PARP1 redistribution to enhance efficacy of PARP inhibitors in breast cancer

Abstract While polyADP-ribose polymerase (PARP) inhibitors have made advancements in the treatment of breast cancer, challenges such as chemotherapy resistance and limited application persist. Fanconi AnemiaComplementation Group I (FANCI), a DNA repair protein associated with breast cancer development, represents a potential target for novel combination therapeutic strategies. However, the role of FANCI in breast cancer and its impact on the efficacy of PARP inhibitors require further investigation. In our study, we analyzed FANCI expression in breast cancer tissues and cell lines, and its correlation with clinical parameters and patient prognosis. Lentiviral vectors were utilized and functional assays were performed to evaluate the effects of FANCI modulation on breast cancer cell growth and migration. Co-immunoprecipitation assays and protein interaction analysis were conducted to identify the interaction between FANCI and PARP1 and determine the specific binding region. The functionality and nuclear distribution of PARP1 were assessed upon FANCI modulation. Finally, the sensitivity of breast cancer cells to the PARP inhibitor talazoparib upon FANCI knockdown was evaluated in vitro and in vivo. Our findings demonstrated that FANCI was overexpressed in breast cancer and associated with poor prognosis. FANCI significantly promoted breast cancer cell proliferation both in vitro and in vivo. We identified the interaction between FANCI and PARP1, specifically at the FANCI helical domain 2 binding site. FANCI knockdown led to reduced nuclear localization of PARP1 and decreased PARP1 activity. Importantly, combination treatment with FANCI knockdown and talazoparib significantly inhibited cancer growth in vitro and in vivo. Additionally, we found that the cyclin-dependent kinase (CDK) 4/6 inhibitor palbociclib, which effectively suppresses FANCI protein expression, exhibited a robust synergistic effect with talazoparib both in vitro and in vivo. In conclusion, FANCI is a novel therapeutic target for breast cancer. Suppression of FANCI regulates PARP1 redistribution and activity, making breast cancer cells more responsive to PARP inhibitors. This combination therapeutic strategy shows potential in enhancing the effectiveness of PARP inhibitors for breast cancer treatment, regardless of BRCA mutations. Citation Format: Yu-zhou Huang, Ming-Yi Sang, Pei-Wen Xi, Ruo-Xi Xu, Meng-Yuan Cai, Zi-Wen Wang, Jian-Yi Zhao, Yi-Han Li, Ji-Fu Wei, Qiang Ding. Emerging combination strategy: FANCI suppression induces PARP1 redistribution to enhance efficacy of PARP inhibitors in breast cancer [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 7220.

Abstract 4390: IGFBP-6 is induced by progesterone to regulate progesterone receptor expression in breast cancer cells

Abstract Insulin-like growth factor binding protein-6 (IGFBP-6) is induced by progesterone (P4) in T-47D breast cancer cells. IGFBP-6 regulates insulin-like growth factor 2 (IGF2) by sequestering it to inhibit receptor binding and extend its extracellular half-life. IGF2 binds to insulin-like growth factor 1 receptor or insulin receptor A to promote breast cancer cell proliferation and survival. Progesterone is an ovarian steroid hormone which has complex roles in breast cancer through the actions of progesterone receptor A and B (PR-A and B). Progesterone antagonizes the actions of estradiol (E2), another steroid hormone which promotes proliferation and survival in breast cancer. T-47D cells treated with both P4 and E2 exhibit significantly reduced proliferation compared to treatment with E2 alone. To better understand the role of IGFBP-6 in progesterone signaling, T-47D cells which over-express IGFBP-6 were treated with P4, E2, or both. Overexpressing cells exhibited stronger antagonism compared to controls when co-treated with P4 and E2. RNA-interference was performed to knockdown IGFBP-6 induction in the presence of P4 and E2. Knockdown of IGFBP-6 in the presence of P4 and E2 decreases the antagonistic effects of P4. Expression of both PR-A and PR-B decreases by about 50% when IGFBP-6 is knocked down. These results indicate that IGFBP-6 increases PR expression in response to P4 stimulation. Citation Format: Francisco Javier Lariz, Pacha Botero, Kevin Houston. IGFBP-6 is induced by progesterone to regulate progesterone receptor expression in breast cancer cells [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 4390.

Abstract 3332: Kalkitoxin thiol amide suppresses the breast cancer metastasis to bone and brain

Abstract Introduction: Breast cancer is the primary frequently diagnosed cancer worldwide, with a high fatality rate. Metastasis resulting from advanced breast cancer increases mortality in patients. MDA-MB-231 is triple-negative breast cancer that does not have any of the receptors that are commonly found in breast cancer. The lipopeptide toxin kalkitoxin thiol amide (KTA), generated from the marine cyanobacterium Moorena producens (formerly Lyngbya majuscule), has a wide range of biological and pharmacological effects. Its promise as a therapeutic agent for treating bone metastases from breast cancer is still uncertain. This study aimed to determine whether KTA could prevent breast cancer from metastasis to mice's bones and to elucidate any potential mechanisms causing this inhibition. Experimental Procedures: MDA-MB-231 cells were transfected with pGL4.50 (Luc2/CMV/Hygro) vector using LipofectamineTM 2000. Positive clones of MDA-MB-231 cells were selected after treatment with 300 µg/ml hygromycin for one week. After cancer implantation to the heart, bioluminescent imaging of femurs was measured upto 5 weeks and signal intensity of KTA-treated groups was compared with the vehicle group. Summary: KTA decreased breast cancer cell proliferation, migration, and invasion. KTA prevented MDA-MB-231 cells from breast cancer metastasizing to the bone and brain via inhibiting MAPK and STAT signaling. The epithelial-mesenchymal transition markers, which are responsible for distant metastasis, are highly opposed by KTA. Compared to mice in the control group, mice receiving KTA displayed considerably less bone and brain metastasis, a lower tumor burden, and less bone destruction in the murine breast cancer bone metastasis model. Conclusion: KTA has new inhibitory effects on cancer cell invasion and migration both in vitro and in vivo. From these findings, KTA may have therapeutic promise for treating breast cancer patients with distant metastases. Citation Format: Yunjo Soh, Saroj Kumar Shrestha, Se woong Kim. Kalkitoxin thiol amide suppresses the breast cancer metastasis to bone and brain [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 3332.

Design of magnetic nanoplatforms for simultaneous molecular imaging and cisplatin delivery for breast cancer cells theranostics

Developing intelligent nanomedicines for cancer diagnosis and treatment (theranostics) is pivotal for improving treatment outcomes. In this study, we synthesized and evaluated dual-mode MRI contrast agents utilizing superparamagnetic iron oxide nanoparticles (SPIONs) as the core and samarium ions as the coating. Samarium ions were grafted onto the polymeric coating layer of the nanoparticles via electrostatic deposition. Characterization of the Cis/Fe3O4/PEG-co-PMMA/SmO2 core/shell structures involved size, morphology, drug loading, encapsulation efficiency, and their potential as T1-T2 dual-model contrast agents. Longitudinal relaxivity (r1) and transverse relaxivity (r2) were estimated using NMR relaxation times. In vivo investigations assessed the effectiveness of Cisplatin, particularly in human breast cancer (MCF-7) cells, using wound healing assays and molecular analysis. Remarkably, the Cis/Fe3O4/PEG-co-PMMA/SmO2 formulation exhibited enhanced cytotoxicity against MCF-7 cells compared to Cisplatin alone, indicating its promising role as an inhibitory agent against breast cancer cell proliferation.

Pan-cancer analysis of NUP155 and validation of its role in breast cancer cell proliferation, migration, and apoptosis

NUP155 is reported to be correlated with tumor development. However, the role of NUP155 in tumor physiology and the tumor immune microenvironment (TIME) has not been previously examined. This study comprehensively investigated the expression, immunological function, and prognostic significance of NUP155 in different cancer types. Bioinformatics analysis revealed that NUP155 was upregulated in 26 types of cancer. Additionally, NUP155 upregulation was strongly correlated with advanced pathological or clinical stages and poor prognosis in several cancers. Furthermore, NUP155 was significantly and positively correlated with DNA methylation, tumor mutational burden, microsatellite instability, and stemness score in most cancers. Additionally, NUP155 was also found to be involved in TIME and closely associated with tumor infiltrating immune cells and immunoregulation-related genes. Functional enrichment analysis revealed a strong correlation between NUP155 and immunomodulatory pathways, especially antigen processing and presentation. The role of NUP155 in breast cancer has not been examined. This study, for the first time, demonstrated that NUP155 was upregulated in breast invasive carcinoma (BRCA) cells and revealed its oncogenic role in BRCA using molecular biology experiments. Thus, our study highlights the potential value of NUP155 as a biomarker in the assessment of prognostic prediction, tumor microenvironment and immunotherapeutic response in pan-cancer.