G1 Phase Arrest Research Articles

HOXC4 promotes proliferation of pancreatic cancer cells by increasing LDHA-mediated glycolysis.

Homeobox C4 (HOXC4) is a member of homeobox family and acts as a transcription factor in regulating morphological development. The current study aimed to determine its role in pancreatic cancer (PC). Bioinformatics analysis was employed to assess the expression and clinical significance of HOXC4 in PC, while the expression of HOXC4 was further confirmed in PC tissues through quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC). The impact of HOXC4 on PC cell proliferation was evaluated using various assays including Cell Counting Kit-8, colony formation, apoptosis detection, cell cycle analysis, and subcutaneous tumorigenesis. Extracellular acidification rate, glucose uptake, and lactate production measurements were detected to examine the impact of HOXC4 on glycolysis. The relationship between HOXC4 and lactate dehydrogenase A (LDHA) was investigated using CHIP assay, luciferase reporter assay, and western blot. Notably, there was a substantial increase in HOXC4 expression in PC, and patients with elevated HOXC4 levels exhibited shorter survival durations. HOXC4 knockdown resulted in significantly reduced proliferation and colony formation in PC cells, accompanied by increased apoptosis and G1 phase arrest. The overexpression of HOXC4 resulted in contrasting effects. In vivo, the proliferation of PC cells was diminished upon the knockdown of HOXC4. HOXC4 exhibited an increase in LDHA expression by binding to its promoter. The suppressive effects of HOXC4 knockdown on PC cells were counteracted upon the restoration of LDHA. In conclusion, HOXC4 promoted the proliferation of PC cells by increasing LDHA-mediated glycolysis. HOXC4 can act as a target for PC therapy.

CTLA-4 silencing could promote anti-tumor effects in hepatocellular.

Preclinical and clinical research showed that immune checkpoint blockade provides beneficial effects for many patients with liver cancer. This study aimed to assess the effect of CTLA-4-specific siRNA on the proliferation, cell cycle, migration, and apoptosis of HePG2 cells. Transfection of siRNA was performed by electroporation. The viability of cells was determined through MTT assay. Flow cytometry was performed to investigate the cell cycle and apoptosis rate, and the wound-healing assay was used to determine HepG2 cells migration. The expression levels of CTLA-4, c-Myc, Ki-67, BCL-2, BAX, caspase-9 (CAS9), and MMP-2,9,13 were measured by qRT-PCR. Transfection of specific CTLA-4-siRNA significantly inhibited the expression of the CTLA-4 gene. Also, our results revealed that CTLA-4 silencing diminished the proliferation and migration as well as induced the apoptosis of HePG2 cells. CTLA-4-siRNA transfection induced the cell cycle arrest in G2 phase. Moreover, CTLA-4-siRNA transfection reduced the expression levels of c-Myc, Ki-67, BCL-2, MMP-2,9,13, and elevated the expression levels of BAX and caspase-9. Our results suggest that silencing CTLA-4 through specific siRNA may be a promising strategy for future therapeutic interventions for treating liver cancer.

Apigenin is an anoikis sensitizer with strong anti-metastatic properties in experimental breast cancer

Loss of susceptibility to anoikis signals is a crucial step in metastasis. Anoikis resistance therefore represents a promising adjuvant therapeutic target for cancer management. In this study, we have conducted a rationalized screening to search for novel leading anoikis sensitizer from daily foods. Among 19 tested dietary phytochemicals, the best results were obtained with apigenin, a natural component of celery. Phenotypically, apigenin sensitized breast cancer cells to anoikis, lowered the number of circulating tumor cells, and protected against breast cancer metastasis to lung in mice. Mechanistically, we demonstrated that the thromboxane A2 (TXA2)-TXA2 receptor (TP) axis has a critical role in acquired anoikis resistance by activating PI3K-Akt signaling pathway. Blockage of TXA2 signaling up-regulated p53 as well as its target gene p21, caused a G1 phase arrest, and finally led to apoptosis in breast cancer cells. TXA2 level was positively correlated with breast cancer cell anoikis rate, and apigenin significantly inhibited TXA2 biosynthesis in vitro and in vivo. Collectively, we identified apigenin as a potent anoikis sensitizer with anti-metastatic properties in a mouse model of breast cancer, and these findings might provide a rationale for introducing apigenin supplementation to breast cancer patients.

SENP1 exacerbates acute myeloid leukemia by enhancing BECN1-dependent autophagy through PTBP1 deSUMOylation.

Genetic association between SUMO-specific protease 1 (SENP1) and acute myeloid leukemia (AML) has been validated. However, the mechanism by which SENP1 affects AML proliferation, apoptosis, and autophagy remains unknown. The levels of SENP1 and polypyrimidine tract-binding protein 1 (PTBP1) were measured in AML patients, AML cell lines, and xenograft tissues. The effects of SENP1 on AML proliferation, apoptosis, and BECN1-dependent autophagy were assessed through in vitro and in vivo loss- or gain-of-function experiments. SUMOylation analysis using immunoprecipitation (IP), RNA pull-down, RIP, and RNA stability assays were used to explore the molecular mechanism of SENP1 in AML development. The SENP1 level was elevated in AML samples. Silencing SENP1 impeded the development of AML, as evidenced by the inhibition of proliferation and promotion of G1 phase arrest and apoptosis resulting from SENP1 depletion in AML cells. Moreover, silencing of SENP1 restrained BECN1-depentent autophagy in AML cells. In addition, the overexpression of BECN1 or PTBP1 partially neutralized the effect of SENP1 knockdown on AML cell behavior. Mechanistically, SENP1 mediated PTBP1 deSUMOylation, which then directly interacted with BECN1 mRNA and enhanced its stability. In vivo experiments further confirmed the repressive effects of SENP1 suppression on AML development. Collectively, the SENP1/PTBP1/BECN1 signaling axis has been identified as a significant therapeutic target for enhancing AML treatment.

PEMF Potentiates Doxorubicin-induced Late G2 Arrest in MDA-MB-231 Breast Cancer Cells.

Pulsed electromagnetic field (PEMF) stimulation enhances the efficacy of several anticancer drugs. Doxorubicin is an anticancer drug used to treat various types of cancer, including breast cancer. However, the effect of PEMF stimulation on the efficacy of doxorubicin and the underlying mechanisms remain unclear. Thus, this study aimed to investigate the effect of PEMF stimulation on the anticancer activity of doxorubicin in MDA-MB-231 human breast cancer cells. MDA-MB-231 cells were seeded and allowed to incubate for 48 h. The cells were treated with doxorubicin, cisplatin, 5-fluorouracil, or paclitaxel for 48 h. Subsequently, the cells were stimulated with a 60-min PEMF session thrice a day (with an interval of 4 h between each session) for 24 or 48 h. Cell viability was assessed by trypan blue dye exclusion assay and cell-cycle analysis was analyzed by flow cytometry. Molecular mechanisms involved in late G2 arrest were confirmed by a western blot assay and confocal microscopy. MDA-MB-231 cells treated with a combination of doxorubicin and PEMF had remarkably lower viability than those treated with doxorubicin alone. PEMF stimulation increased doxorubicin-induced cell-cycle arrest in the late G2 phase by suppressing cyclin-dependent kinase 1 (CDK1) activity through the enhancement of myelin transcription factor 1 (MYT1) expression, cell division cycle 25C (CDC25C) phosphorylation, and stratifin (14-3-3σ) expression. PEMF also increased doxorubicin-induced DNA damage by inhibiting DNA topoisomerase II alpha (TOP2A). These findings support the use of PEMF stimulation as an adjuvant to strengthen the antiproliferative effect of doxorubicin on breast cancer cells.

Mannan-binding lectin inhibits oxidative stress-induced senescence via the NAD+/Sirt1 pathway

Prolonged or excessive oxidative stress can lead to premature cellular and body aging. Mannan-binding lectin (MBL) is synthesized by the liver and plays an important role in innate immunity, anti-inflammation, and anti-oxidation, and has a positive impact on health and longevity. To date, few studies investigated the role of MBL in attenuating oxidative stress-induced senescence. In this study, we evaluated the role of MBL in oxidative stress-induced premature aging and explored its underlying mechanism in C57BL/6 mice and mouse embryonic fibroblasts (NIH/3T3). First, we established an oxidative premature senescence model induced by D-galactose in C57BL/6 mice. We found that MBL-deficient mice had a marked aging-like appearance, reduced learning and spatial exploration abilities, severe liver pathological damage, and significantly upregulated expression of Senescence-associated proteins (p53 and p21), inflammatory kinesins (IL-1β and IL-6), and the senescence β-galactosidase (SA-β-Gal) positive rate as compared with WT mice. In the H2O2-induced oxidative senescence model of NIH/3T3 cells, consistent results were obtained after MBL intervention. In addition, MBL effectively inhibited G1 phase arrest, ROS levels, DNA damage, and mitochondrial dysfunction in premature senescent cells. Mechanistically, we found that oxidative stress inhibited the nicotinamide adenine dinucleotide (NAD+)/ silent information regulator 1 (Sirt1) signaling pathway, while MBL activated the NAD+/Sirt1 signaling pathway inhibited by oxidative stress. In addition, MBL could activate the NAD+/Sirt1 pathway by upregulating NAMPT, which in turn inhibited p38 phosphorylation by activating the NAD+/Sirt1 pathway. In conclusion, MBL inhibits oxidative aging, which may facilitate the development of therapeutics to delay oxidative aging.

The PPP2R1A cancer hotspot mutant p.R183W increases clofarabine resistance in uterine serous carcinoma cells by a gain-of-function mechanism.

Uterine serous carcinoma (USC) is generally associated with poor prognosis due to a high recurrence rate and frequent treatment resistance; hence, there is a need for improved therapeutic strategies. Molecular analysis of USC identified several molecular markers, useful to improve current treatments or identify new druggable targets. PPP2R1A, encoding the Aα subunit of the tumor suppressive Ser/Thr phosphatase PP2A, is mutated in up to 40% of USCs. Here, we investigated the effect of the p.R183W PPP2R1A hotspot variant on treatment response to the nucleoside analogue clofarabine. USC cells stably expressing p.R183W Aα showed increased resistance to clofarabine treatment in vitro and, corroborated by decreased clofarabine-induced apoptosis, G1 phase arrest, DNA-damage (γH2AX) and activation of ATM and Chk1/2 kinases. Phenotypic rescue by pharmacologic PP2A inhibition or dicer-substrate siRNA (dsiRNA)-mediated B56δ subunit knockdown supported a gain-of-function mechanism of Aα p.R183W, promoting dephosphorylation and inactivation of deoxycytidine kinase (dCK), the cellular enzyme responsible for the conversion of clofarabine into its bioactive form. Therapeutic assessment of related nucleoside analogues (gemcitabine, cladribine) revealed similar effects, but in a cell line-dependent manner. Expression of two other PPP2R1A USC mutants (p.P179R or p.S256F) did not affect clofarabine response in our cell models, arguing for mutant-specific effects on treatment outcome as well. While our results call for PPP2R1A mutant and context-dependent effects upon clofarabine/nucleoside analogue monotherapy, combining clofarabine with a pharmacologic PP2A inhibitor proved synergistically in all tested conditions, highlighting a new generally applicable strategy to improve treatment outcome in USC.

REST Promotes Autophagy in Gastric Cancer by Transcriptionally Activating FABP6 to Inhibit the Akt/mTOR Signaling Pathway.

Gastric cancer (GC) is a leading cause of cancer-associated death worldwide. Its molecular mechanisms, especially concerning autophagy and various signaling pathways, are not fully understood. Fatty Acid Binding Protein 6 (FABP6) and RE1 Silencing Transcription Factor (REST) emerge as potential key players in this context. This study sought to analyze the functional relationship of FABP6 and REST concerning autophagy and their implications on the Akt/mTOR signaling pathway within GC cells. A comprehensive bioinformatics approach was used to identify key prognostic markers in GC. The effects of FABP6 and REST on autophagy along with Akt/mTOR signaling pathways were analyzed by techniques including Western blotting (WB), flow cytometry, Transwell assay, dual luciferase reporter assay, and others. FABP6 was identified as overexpressed in GC, linked with poor prognosis. FABP6 silencing reduces GC cell proliferation, induces S- and G2-phase arrest, and downregulates cyclins CDK2 and CDK4. It also inhibited GC cell invasion/migration and autophagy, effects that were counteracted by MG132. When combined with PI3K inhibitor LY294002c, FABP6 knockdown showed synergistic anti-proliferative effects, modulating the Akt/mTOR pathway. Besides, the transcription factor REST has been shown to directly regulate FABP6 expression, affecting autophagy and the Akt/mTOR signaling pathway in a FABP6-dependent manner. REST positively regulates autophagy and negatively affects the Akt/mTOR signaling pathway in GC cells in a FABP6-dependent manner, providing valuable insights into regulatory networks involving FABP6 and REST.

Pharmacophore-based, rationale design, and efficient synthesis of novel tetrahydrobenzo[b]thiophene candidates as potential dual Topo I/II inhibitors and DNA intercalators.

A series of tetrahydrobenzo[b]thiophene derivatives was designed and synthesized as dual topoisomerase (Topo) I/II inhibitors implicating potential DNA intercalation. Ethyl-2-amino-3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophene-4-carboxylate (1) was prepared by modification of the Gewald reaction procedure using a Fe2O3 nanocatalyst and then it was used as a building block for the synthesis of tetrahydrobenzo[b]thiophene candidates (2-14). Interestingly, compound 14 showed the best cytotoxic potential against hepatocellular, colorectal, and breast cancer cell lines (IC50 = 7.79, 8.10, and 3.53 µM), respectively, surpassing doxorubicin at breast cancer (IC50 = 4.17 µM). Meanwhile, the Topo I and II inhibition assay displayed that compound 3 could exhibit the best inhibitory potential among the investigated candidates (IC50 = 25.26 and 10.01 nM), respectively, in comparison to camptothecin (IC50 = 28.34 nM) and doxorubicin (IC50 = 11.01 nM), as reference standards. In addition, the DNA intercalation assay showed that compound 14 could display the best binding affinity with an IC50 value of 77.82 µM in comparison to doxorubicin (IC50 = 58.03 µM). Furthermore, cell cycle and apoptosis analyses described that compound 3 prompts the G1 phase arrest in michigan cancer foundation-7 cancer cells and increases the apoptosis ratio by 29.31% with respect to untreated cells (2.25%). Additionally, the conducted molecular docking assured the promising binding of the investigated members toward Topo I and II with potential DNA intercalation. Accordingly, the synthesized compounds could be treated as promising anticancer candidates for future optimization.

Discovery and biological evaluation of biaryl acetamide derivatives as selective and in vivo active sphingosine kinase-2 inhibitors

Sphingosine kinase 2 (SphK2) has emerged as a promising target for cancer therapy due to its critical role in tumor growth. However, the lack of potent and selective inhibitors has hindered its clinical application. Herein, we report the design and synthesis of a series of novel SphK2 inhibitors, culminating in the identification of compound 12q as a highly selective and potent inhibitor of SphK2. Molecular dynamics simulations suggest that the incorporation of larger substitution groups facilitates a more effective occupation of the binding site, thereby stabilizing the complex. Compared to the widely used inhibitor ABC294640, compound 12q exhibits superior anti-proliferative activity against various cancer cells, inducing G2 phase arrest and apoptosis in liver cancer cells HepG2. Notably, 12q inhibited migration and colony formation in HepG2 and altered intracellular sphingolipid content. Moreover, intraperitoneal administration of 12q in mice resulted in decreased levels of S1P. 12q provides a valuable tool compound for exploring the therapeutic potential of targeting SphK2 in cancer.

Gallic acid pretreatment mitigates parathyroid ischemia–reperfusion injury through signaling pathway modulation

Thyroid surgery often results in ischemia–reperfusion injury (IRI) to the parathyroid glands, yet the mechanisms underlying this and how to ameliorate IRI remain incompletely explored. Our study identifies a polyphenolic herbal extract—gallic acid (GA)—with antioxidative properties against IRI. Through flow cytometry and CCK8 assays, we investigate the protective effects of GA pretreatment on a parathyroid IRI model and decode its potential mechanisms via RNA-seq and bioinformatics analysis. Results reveal increased apoptosis, pronounced G1 phase arrest, and significantly reduced cell proliferation in the hypoxia/reoxygenation group compared to the hypoxia group, which GA pretreatment mitigates. RNA-seq and bioinformatics analysis indicate GA’s modulation of various signaling pathways, including IL-17, AMPK, MAPK, transient receptor potential channels, cAMP, and Rap1. In summary, GA pretreatment demonstrates potential in protecting parathyroid cells from IRI by influencing various genes and signaling pathways. These findings offer a promising therapeutic strategy for hypoparathyroidism treatment.

Unveiling a cuproptosis-related risk model and the role of FARSB in hepatocellular carcinoma

BackgroundCuproptosis, a type of regulated cell death that was recently identified, has been linked to the development of a variety of diseases, among them being cancers. Nevertheless, the prognostic significance and therapeutic implications of the cuproptosis potential index in hepatocellular carcinoma (HCC) remain uncertain. MethodsSingle-sample gene set enrichment analysis (ssGSEA) and Weighted Gene Co-expression Network Analysis (WGCNA) methodology was conducted to ascertain the identification of modular genes that are closely linked to cuproptosis. In addition, the gene signature indicative of prognosis was formulated by employing univariate Cox regression analysis in conjunction with a random forest algorithm. The efficacy of this gene signature in predicting outcomes was confirmed through validation in both The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) datasets. Furthermore, a study was undertaken to evaluate the association between the risk score and various clinical-pathological characteristics, explore the biological processes linked to the gene signature, and analyze tumor mutational burden and somatic mutations. Lastly, potential drugs targeting the identified gene signature were identified through screening. ResultsThe results of our comprehensive analysis across multiple cancer types demonstrated a positive correlation between an elevated cuproptosis potential index (CPI) and an accelerated rate of tumor progression. Furthermore, employing the WGCNA technique, we successfully identified 640 genes associated with cuproptosis. Among these genes, we meticulously screened and validated a seven-gene signature (TCOF1, NOP58, TMEM69, FARSB, DHX37, SLC16A3, and CBX2) that exhibited substantial prognostic significance. Using the median risk score, the division of HCC patients into cohorts with high- and low-risk highlighted significant disparities in survival results, wherein the group with higher risk exhibited a less favorable overall survival. The risk score exhibited commendable predictive efficacy. Moreover, the in vitro knockdown of FARSB significantly hindered cell viability, induced G1 phase arrest, increased apoptosis, and impaired migration in HepG2 and Huh7 cells. ConclusionOur research has successfully identified a strong seven-gene signature linked to cuproptosis, which could be utilized for prognostic evaluation and risk stratification in patients with HCC. Furthermore, the discovered gene signature, coupled with the functional analysis of FARSB, presents promising prospects as potential targets for therapeutic interventions in HCC.

Circular RNA hsa_circ_0005939 Regulates UHRF1BP1L Expression by Targeting miR-4693-3p to Promote Colorectal Cancer Progression.

Colorectal cancer (CRC) is the second most common and fatal cancer in China. circRNAs are different expressed between tumor and non-tumor tissues, and they are proved to be correlated with tumorigenesis and cancer progression. We aimed to explore the biological and molecular function of hsa_circ_0005939 in CRC. We collected and compared ten CRC tissues and four noncancerous tissues and performed circRNA sequencing. We investigated the hsa_circ_0005939 expression in fresh tissues from CRC and adjacent tissues by qPCR. Meanwhile, functional roles of hsa_circ_0005939 in CRC cells were explored by CCK-8, colony formation, wounding healing, cell apoptosis and western blot assays. RNA-FISH was used to confirm the cellular distribution of hsa_circ_0005939. Bioinformatic prediction and luciferase reporter assay were used to determine the mechanisms of hsa_circ_0005939. Our results indicated that hsa_circ_0005939 was up-regulated in CRC tissues and cells. Up-regulation of hsa_circ_0005939 was associated with the occurrence and the number of lymph node metastasis of CRC. Hsa_circ_0005939 down-regulation inhibited cell proliferation, increased cell apoptosis and caused G2 phase arrest of CRC cells. Mechanistically, luciferase assay revealed that hsa_circ_0005939 acts as a molecular sponge for miR-4693-3p and then enhanced Ubiquitin Like With PHD And Ring Finger Domains 1 binding protein 1 like (UHRF1BP1L) expression. Our findings indicated an oncogenic role of hsa_circ_0005939 in CRC, and it enhanced malignant phenotypes of CRC cells through miR-4693-3p/UHRF1BP1L axis. Our study may offer promising biomarkers and therapeutic targets for CRC.

Identification of novel GSPT1 degraders by virtual screening and bioassay

GSPT1 plays crucial physiological functions, such as terminating protein translation, overexpressed in various tumors. It is a promising anti-tumor target, but is also considered as an “undruggable” protein. Recent studies have found that a class of small molecules can degrade GSPT1 through the “molecular glue” mechanism with strong antitumor activity, which is expected to become a new therapy for hematological malignancies. Currently available GSPT1 degraders are mostly derived from the scaffold of immunomodulatory imide drug (IMiD), thus more active compounds with novel structure remain to be found. In this work, using computer-assisted multi-round virtual screening and bioassay, we identified a non-IMiD acylhydrazone compound, AN5782, which can reduce the protein level of GPST1 and obviously inhibit the proliferation of tumor cells. Some analogs were obtained by a substructure search of AN5782. The structure-activity relationship analysis revealed possible interactions between these compounds and CRBN-GSPT1. Further biological mechanistic studies showed that AN5777 decreased GSPT1 remarkably through the ubiquitin-proteasome system, and its effective cytotoxicity was CRBN- and GSPT1-dependent. Furthermore, AN5777 displayed good antiproliferative activities against U937 and OCI-AML-2 cells, and dose-dependently induced G1 phase arrest and apoptosis. The structure found in this work could be good start for antitumor drug development.

Minnelide exhibits antileukemic activity by targeting the Ars2/miR-190a-3p axis

BackgroundThe identification of a novel and effective strategy for the clinical treatment of acute leukemia (AL) is a long-term goal. Minnelide, a water-soluble prodrug of triptolide, has recently been evaluated in phase I and II clinical trials in patients with multiple cancers and has shown promise as an antileukemic agent. However, the molecular mechanism underlying minnelide's antileukemic activity remains unclear. PurposeTo explore the molecular mechanisms by which minnelide exhibits antileukemic activity. MethodsAL cells, primary human leukemia cells, and a xenograft mouse model were treated with triptolide and minnelide. The molecular mechanism was elucidated using western blotting, immunoprecipitation, flow cytometry, GSEA and liquid chromatography-mass spectrometry analysis. ResultsMinnelide was highly effective in inhibiting leukemogenesis and improving survival in two complementary AL mouse models. Triptolide, an active form of minnelide, causes cell cycle arrest in G1 phase and induces apoptosis in both human AL cell lines and primary AL cells. Mechanistically, we identified Ars2 as a new chemotherapeutic target of minnelide for AL treatment. We found that triptolide directly targeted Ars2, resulting in the downregulation of miR-190a-3p, which led to the disturbance of PTEN/Akt signaling and culminated in G1 cell cycle arrest and apoptosis. ConclusionsOur findings demonstrate that targeting Ars2/miR-190a-3p signaling using minnelide could represent a novel chemotherapeutic strategy for AL treatment and support the evaluation of minnelide for the treatment of AL in clinical trials.

Deciphering Annona's Anticancer Potential: Comparative Analysis of Crude Extract Versus Nanoformulation on SCC-25 Oral Cancer Cells Through cell Viability, Apoptosis, Cell Cycle, ROS, and MMP Analysis.

Annona muricata contains acetogenins, which have shown promising anticancer activity against various cell lines. This study aims to evaluate and compare the anticancer activity of the crude extract of Annona muricata and its nano formulation on Squamous Cell Carcinoma-25 (SCC-25) oral cancer cell lines. The crude extract of Annona muricata was prepared using standard extraction techniques, while its nano formulation was synthesized through nanoparticle fabrication methods. Authenticated SCC-25 cell lines were obtained from ATCC and cultured and treated with varying concentrations of both the crude extract and nano formulation. Cell viability assays, apoptosis assays, Cell Cycle assay, ROS, and MMP analysis techniques were employed to assess the anticancer activity and mechanism of action. In the MTT assay, the Annona formulation treated cells exhibited lower IC50 values compared to the crude extract treated SCC-25 cell lines. In the cell cycle assay, the Annona crude extract inducedhigher cell cycle arrest in the G1 phase in SCC-25 cell lines compared to the control. The nano formulationof Annona demonstrated significantly higher cell cycle arrest in G1 phase compared to both the control and the Annona crude extract-treated SCC-25 cell lines. The crude extract showed less apoptotic activity in apoptosis assay when compared to control, whereas the Annona formulation exhibited higher late apoptosis compared to the control, indicating the potential anticancer properties of Annona. The mean fluorescent intensity test of SCC-25 oral cancer cells treated with Annona crude extract and Annona formulation showed a significant loss of Mitochondrial membrane potential compared to the control. The percentage of MMP was lower in Annona-treated cells, while the Annona formulationtreated cells showed similar results to the control. The mean fluorescent intensity of ROS in SCC-25 oral cancer cells treated with Annona crude extract and Annona formulation showed significantly lower Reactive oxygen species production compared to the control. The percentage of ROS was lower in Annona treated cells compared to the formulation, but the Annona formulation-treated cells showed lower values than the control. In conclusion, both the crude extract and nano formulation of Annona muricata possess potent anticancer activity against SCC-25 oral cancer cell lines. However, the nano formulation exhibited superior efficacy, suggesting its potential for further development as a therapeutic agent for oral cancer treatment.

Abstract PO5-23-09: Metabolic alterations in Estrogen Receptor-positive breast cancer contributing to CDK4/6 resistance

Abstract Background CDK4/6 inhibitors (CDK4/6i) are potent FDA-approved agents for the treatment of metastatic and for high-risk early estrogen receptor positive (ER+) breast cancer. However, significant proportion of patients continue to develop disease progression. Response does not correlate well with expression of CDK4/6 or key cell cycle proteins. Ki67, a proliferation marker, is prognostic, but NOT predictive of response. Resistance to CDK4/6i is mediated by multiple mechanisms including metabolic alterations. Herein, we explore the metabolic alterations associated with development of CDK4/6i resistance. Methods To understand the key metabolic alterations associated with resistance, we first developed abemaciclib-resistant ER+ cell lines and compared their metabolic profile with their parental/sensitive counterparts. Seahorse metabolic profiles were performed on parental cells (MCF-7, LCC2, LCC9, T47D and ZR-75.1) and their resistant derivatives. In addition, spatial proteomics analysis was performed using multiplex cyclic immunofluorescence (CycIF) assay for 27 markers including 14 metabolic regulators (MCT1, GLUT1, G6PD, VDAC1/3, LDHA, GAPDH, PGC1A, HK2, ATP5A, GLUD12, CPT1A, CS, C6 Ceramide, COXIV), 9 signaling (CD36, CCND1, CCNE1, pRB, MKI67, pERK, CDH1, GPNMB and MET) and 4 segmentation markers (pan-cytokeratin for epithelial cells, concanavalin A for endoplasmic reticulum, phalloidin for actin, and wheat germ agglutinin (WGA) for Golgi and plasma membrane) in sensitive and resistant cells. Following the image registration (hiPlex) and cell segmentation (CellProfiler), multiplex protein images were clustered for cell phenotypes (HistoCAT). Results Cells resistant to abemaciclib showed G1 phase arrest, but a dramatic increase in invasive capacity. The Seahorse XFp Cell Energy Phenotype Assay demonstrated altered metabolic profiles including decreased extracellular acidification rate (ECAR) and oxygen consumption rate (OCAR) indicative of glycolysis, and mitochondrial respiration, respectively, in resistant cells. Multiplex CycIF utilized a panel of 11 cycles resulting in a total of 27 markers. We demonstrated that three metabolic enzymes, mitochondrial voltage-dependent anion channel protein (VDAC1/3), lactate Dehydrogenase A (LDHA) and PPARγ coactivator 1α (PGC1α) are significantly overexpressed in CDK4/6 resistant cells compared to the control parental sensitive cells. Further analyses are ongoing to better characterize these changes in human samples treated with CDK4/6i. Conclusion Our findings highlight the importance of metabolic pathways in development of resistance to CDK4/6i treatment. Understanding the mechanisms by which these pathways contribute to therapeutic failure will further provide with novel intervention strategies and new avenues for prevent recurrence/resistance in ER+ breast cancer. Citation Format: Mayar Allam, Ahmet Coskun, Thomas Hu, Yuan Gu, Sunil Badve, Yesim Gokmen-Polar. Metabolic alterations in Estrogen Receptor-positive breast cancer contributing to CDK4/6 resistance [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-23-09.

Hsa-miR-CHA2, a novel microRNA, exhibits anticancer effects by suppressing cyclin E1 in human non-small cell lung cancer cells

Despite considerable therapeutic advancements, the global survival rate for lung cancer patients remains poor, posing challenges in developing an effective treatment strategy. In many cases, microRNAs (miRNAs) exhibit abnormal expression levels in cancers, including lung cancer. Dysregulated miRNAs often play a crucial role in the development and progression of cancer. Therefore, understanding the mechanisms underlying aberrant miRNA expression during carcinogenesis may provide crucial clues to develop novel therapeutics. In this study, we identified and cloned a novel miRNA, hsa-miR-CHA2, which is abnormally downregulated in non-small cell lung cancer (NSCLC)-derived cell lines and tissues of patients with NSCLC. Furthermore, we found that hsa-miR-CHA2 regulates the post-transcriptional levels of Cyclin E1 (CCNE1) by binding to the 3′-UTR of CCNE1 mRNA. CCNE1, a cell cycle regulator involved in the G1/S transition, is often amplified in various cancers. Notably, hsa-miR-CHA2 overexpression led to the alteration of the Rb-E2F pathway, a significant signaling pathway in the cell cycle, by targeting CCNE1 in A549 and SK-LU-1 cells. Subsequently, we confirmed that hsa-miR-CHA2 induced G1-phase arrest and exhibited an anti-proliferative effect by targeting CCNE1. Moreover, in subcutaneous xenograft mouse models, intra-tumoral injection of polyplexed hsa-miR-CHA2 mimic suppressed tumor growth and development. In conclusion, hsa-miR-CHA2 exhibited an anticancer effect by targeting CCNE1 both in vitro and in vivo. These findings suggest the potential role of hsa-miR-CHA2 as an important regulator of cell proliferation in molecular-targeted therapy for NSCLC.

Astaxanthin suppresses the malignant behaviors of nasopharyngeal carcinoma cells by blocking PI3K/AKT and NF-κB pathways via miR-29a-3p

BackgroundAs a natural extraction, astaxanthin is gaining increasing attention because of its safety and anti-tumor properties. It has been reported to participate in the progression of various types of cancer such as gastric cancer and ovarian cancer. Nevertheless, the role of astaxanthin in nasopharyngeal carcinoma (NPC) has not been investigated.ObjectThe study aimed to explore the anticancer mechanism of astaxanthin in regulating NPC cell proliferation, cell cycle progression, apoptosis, migration, and invasion.MethodsHuman NPC cells (C666-1) were treated with different concentrations of astaxanthin (0, 1, 10, 20 mg/mL) followed by detection of cell viability. Then, C666-1 cell proliferation, apoptosis, cell cycle progression, invasion, and migration in response to 10 mg/mL astaxanthin, LY294002 (PI3K/AKT inhibitor) or parthenolide (PTL; NF-κB inhibitor) treatment were measured using cell counting kit-8 assay, colony forming assay, flow cytometry analyses, Transwell assay, and wound healing assay, respectively. Western blotting was performed to quantify protein levels of factors involved in PI3K/AKT and NF-κB signaling pathways, cell cycle phase markers (Cyclin D1, p21) and apoptotic markers (Bcl-2 and Bax).ResultsC666-1 cell proliferation, invasion, and migration were significantly suppressed by astaxanthin while cell apoptosis and cell cycle arrest at G1 phase were effectively enhanced in the context of 10 mg/mL astaxanthin. Protein levels of p-AKT, p-P65 and p-IκB levels were suppressed by astaxanthin treatment. After LY294002 or PTL treatment, the suppressive impact of astaxanthin on C666-1 cell process was strengthened, accompanied by the more obvious decrease in cell activity and cell colony number, more enhanced cell apoptosis and G1 phase arrest, and further inhibited cell migration and invasion. Moreover, the inhibitory effect of astaxanthin on Cyclin D1 and Bcl-2 protein levels as well as the promoting impact of astaxanthin on p21 and Bax were also amplified in combination with LY294002 or PTL treatment.ConclusionsAstaxanthin significantly suppresses NPC cell proliferation, cell cycle arrest, migration, invasion while promoting cell apoptosis by inactivating PI3K/AKT and NF-κB pathways. The study first reveals the anticancer role of astaxanthin in NPC, providing a potential candidate for NPC treatment.

Dexrazoxane inhibits the growth of esophageal squamous cell carcinoma by attenuating SDCBP/MDA-9/syntenin-mediated EGFR-PI3K-Akt pathway activation

Syndecan-binding protein (SDCBP) was reported to stimulate the advancement of esophageal squamous cell carcinoma (ESCC) and could potentially be a target for ESCC treatment. There is a growing corpus of research on the anti-tumor effects of iron chelators; however, very few studies have addressed the involvement of dexrazoxane in cancer. In this study, structure-based virtual screening was employed to select drugs targeting SDCBP from the Food and Drug Administration (FDA)-approved drug databases. The sepharose 4B beads pull-down assay revealed that dexrazoxane targeted SDCBP by interacting with its PDZ1 domain. Additionally, dexrazoxane inhibited ESCC cell proliferation and anchorage-independent colony formation via SDCBP. ESCC cell apoptosis and G2 phase arrest were induced as measured by the flow cytometry assay. Subsequent research revealed that dexrazoxane attenuated the binding ability between SDCBP and EGFR in an immunoprecipitation assay. Furthermore, dexrazoxane impaired EGFR membrane localization and inactivated the EGFR/PI3K/Akt pathway. In vivo, xenograft mouse experiments indicated that dexrazoxane suppressed ESCC tumor growth. These data indicate that dexrazoxane might be established as a potential anti-cancer agent in ESCC by targeting SDCBP.