Inhibited Breast Cancer Cell Proliferation Research Articles

Aspongopus chinensis ach-miR-276a-3p induces breast cancer cell cycle arrest by targeting APPL2 to regulate the CDK2-Rb-E2F1 signaling pathway

Breast cancer, the most common cancer, presents a significant challenge to the health and longevity of women. Aspongopus chinensis Dallas is an insect with known anti-breast cancer properties. However, the anti-breast cancer effects and underlying mechanisms have not been elucidated. Exogenous microRNAs (miRNAs), which are derived from plants and animals, have been revealed to have notable capacities for controlling the proliferation of cancerous cells. To elucidate the inhibitory effects of miRNAs derived from A. chinensis and the regulatory mechanism involved in the growth of breast cancer cells, miRNA sequencing was initially employed to screen for miRNAs both in A. chinensis hemolymph and decoction and in mouse serum and tumor tissue after decoction gavage. Subsequently, the experiments were performed to assess the suppressive effect of ach-miR-276a-3p, the miRNA screened out from a previous study, on the proliferation of MDA-MB-231 and MDA-MB-468 breast cancer cell lines in vitro and in vivo. Finally, the regulatory mechanism of ach-miR-276a-3p in MDA-MB-231 and MDA-MB-468 breast cancer cells was elucidated. The results demonstrated that ach-miR-276a-3p notably inhibited breast cancer cell proliferation, migration, colony formation, and invasion and induced cell cycle arrest at the G0/G1 phase. Moreover, the ach-miR-276a-3p mimics significantly reduced the tumor volume and weight in xenograft tumor mice. Furthermore, ach-miR-276a-3p could induce cell cycle arrest by targeting APPL2 and regulating the CDK2-Rb-E2F1 signaling pathway. In summary, ach-miR-276a-3p, derived from A. chinensis, has anti-breast cancer activity by targeting APPL2 and regulating the CDK2-Rb-E2F1 signaling pathway and can serve as a promising candidate anticancer agent.

Characterization of KIF20B as a novel prognostic biomarker and therapeutic target for breast cancer.

Despite advances in treatment and early detection, breast cancer remains one of the most common types of cancer and is the second leading cause of cancer death after lung cancer in women. Therefore, there is an urgent need to develop new biomarkers and therapeutic targets for the treatment of breast cancer. Based on gene expression profiles and subsequent screening performed in a preliminary study, kinesin family member 20B (KIF20B) was selected as a candidate target molecule, because it was highly and frequently expressed in all subtypes of breast cancer and barely detected in normal tissues. Reverse transcription‑quantitative PCR and western blotting revealed that KIF20B mRNA and protein expression levels were upregulated in most breast cancer cell lines but were scarcely expressed in normal mammary epithelial cells. Immunohistochemical staining of a tissue microarray showed that KIF20B was detected in 145 out of 251 (57.8%) breast cancer tissues. Strong KIF20B expression was significantly related to advanced pathological N stage. Moreover, patients with breast cancer and strong KIF20B expression exhibited a significantly worse prognosis than those with weak or negative KIF20B expression (P<0.0001, log‑rank test). In multivariate analysis, strong expression was an independent prognostic factor for patients with breast cancer. Furthermore, knockdown of KIF20B expression by small interfering RNA inhibited breast cancer cell proliferation and induced apoptosis. In addition, Matrigel cell invasion assays revealed that the invasiveness of breast cancer cells was significantly decreased by KIF20B silencing. Since KIF20B is an oncoprotein that is strongly expressed in highly malignant clinical breast cancer and serves a pivotal role in breast cancer cell proliferation, survival and invasion, KIF20B could be considered a candidate biomarker for prognostic prediction and a potential molecular target for developing new therapeutics, such as small molecule inhibitors, for a wide variety of breast cancers.

MiR-30d-5p inhibits proliferation, invasion and migration of breast cancer cells by targeting SERPINE1 and promoting fatty acid β-oxidation.

Breast cancer (BC) is among the top three most prevalent cancers across the world, especially in women, and its pathogenesis is still unknown. Fatty acid β-oxidation is highly associated with breast cancer. Serpin family E member 1 (SERPINE1)-induced down-regulation of fatty acid β-oxidation can facilitate BC cell proliferation, invasion, and metastasis. In this paper, the difference of miR-30d-5p expressions in both cancerous tissues and para-carcinoma tissues was first detected. Next, the expressions of SERPINE1, long-chain acyl-CoA dehydrogenase (LCAD) and medium-chain acyl-CoA dehydrogenase (MCAD) in the aforementioned tissues were analyzed. Finally, miR-30d-5p mimics were supplemented to breast cancer cells to observe the miR-30d-5p effect upon breast cancer cells. Via immunofluorescence assay and Western blotting, it was found that cancerous tissues had lower expressions of miR-30d-5p, MCAD and LCAD and a higher expression of SERPINE1 than para-carcinoma tissues. The miR-30d-5p mimic group had a decreased SERPINE1 expression and increased MCAD and LCAD expressions compared with the NC group, thus inhibiting BC cell proliferation, invasion, and metastasis. To sum up, miR-30d-5p blocks the cell proliferation, invasion and metastasis by targeting SERPINE1 and promoting fatty acid β-oxidation. Preclinical studies are further required to establish a fatty acid β-oxidation-targeting therapy for breast cancer.

Natural 2',4-Dihydroxy-4',6'-dimethoxy Chalcone Isolated from Chromolaena tacotana Inhibits Breast Cancer Cell Growth through Autophagy and Mitochondrial Apoptosis.

Breast cancer (BC) is one of the most common cancers among women. Effective treatment requires precise tailoring to the genetic makeup of the cancer for improved efficacy. Numerous research studies have concentrated on natural compounds and their anti-breast cancer properties to improve the existing treatment options. Chromolaena tacotana (Klatt) R.M. King and H. Rob (Ch. tacotana) is a notable source of bioactive hydroxy-methylated flavonoids. However, the specific anti-BC mechanisms of these flavonoids, particularly those present in the plant's inflorescences, remain partly undefined. This study focuses on assessing a chalcone derivative extracted from Ch. tacotana inflorescences for its potential to concurrently activate regulated autophagy and intrinsic apoptosis in luminal A and triple-negative BC cells. We determined the chemical composition of the chalcone using ultraviolet (UV) and nuclear magnetic resonance (NMR) spectroscopy. Its selective cytotoxicity against BC cell lines was assessed using the MTT assay. Flow cytometry and Western blot analysis were employed to examine the modulation of proteins governing autophagy and the intrinsic apoptosis pathway. Additionally, in silico simulations were conducted to predict interactions between chalcone and various anti-apoptotic proteins, including the mTOR protein. Chalcone was identified as 2',4-dihydroxy-4',6'-dimethoxy-chalcone (DDC). This compound demonstrated a selective inhibition of BC cell proliferation and triggered autophagy and intrinsic apoptosis. It induced cell cycle arrest in the G0/G1 phase and altered mitochondrial outer membrane potential (∆ψm). The study detected the activation of autophagic LC3-II and mitochondrial pro-apoptotic proteins in both BC cell lines. The regulation of Bcl-XL and Bcl-2 proteins varied according to the BC subtype, yet they showed promising molecular interactions with DDC. Among the examined pro-survival proteins, mTOR and Mcl-1 exhibited the most favorable binding energies and were downregulated in BC cell lines. Further research is needed to fully understand the molecular dynamics involved in the activation and interaction of autophagy and apoptosis pathways in cancer cells in response to potential anticancer agents, like the hydroxy-methylated flavonoids from Ch. tacotana.

2'-Hydroxychalcone Induces Autophagy and Apoptosis in Breast Cancer Cells via the Inhibition of the NF-κB Signaling Pathway: In Vitro and In Vivo Studies.

2'-Hydroxychalcone is a hydroxyl derivative of chalcones, which are biosynthetic precursors of flavonoids and rich in the human diet. The anticancer activity of 2'-hydroxychalcone has been reported in several cancers but remains to be investigated in breast cancer. In the current study, 2'-hydroxychalcone showed significant cytotoxicity against breast cancer cell lines MCF-7 and CMT-1211. It could inhibit breast cancer cell proliferation, migration, and invasion in vitro and suppress tumor growth and metastasis in vivo. Mechanistic investigation revealed that the NF-κB pathway was significantly inhibited by 2'-hydroxychalcone treatment accompanied by an excessive intracellular accumulation of reactive oxygen species, induction of endoplasmic reticulum stress, and activation of JNK/MAPK. In addition, 2'-hydroxychalcone elevated the autophagic levels in breast cancer cells equipped with increasing numbers of autophagy vesicles and complete autophagic flux. Finally, autophagy-dependent apoptosis was observed in 2'-hydroxychalcone-induced cell death. In conclusion, 2'-hydroxychalcone enhances the autophagic levels and induces apoptosis in breast cancer cells, which could be contributed to the inhibition of the pro-survival NF-κB signaling, indicating a promising potential for 2'-hydroxychalcone in future anticancer drug development.

Long noncoding RNA SNHG1 promotes breast cancer progression by regulating the miR-641/RRS1 axis

An increasing number of studies have indicated the crucial involvement of long non-coding RNAs (lncRNAs) in the onset and progression of malignancies. However, a complete understanding of the molecular mechanism underlying the effect of abnormally expressed lncRNAs on breast cancer (BC) remains elusive. This study aimed to elucidate the influence of the lncRNA small nucleolar RNA host gene 1 (SNHG1) on BC progression and its underlying mechanism. Our findings revealed a conspicuous up-regulation of SNHG1 in both BC tissues and cells. The downregulation of SNHG1 was observed to inhibit BC cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) processes, while simultaneously promoting apoptosis. Furthermore, dual-luciferase reporter gene and RNA pull-down assays established that SNHG1 targeted miR-641 expression, while miR-641 targeted RRS1. Rescue studies demonstrated that in vitro SNHG1 silencing could be reversed by the miR-641 inhibitor, as well as by RRS1 upregulation. Moreover, in vivo downregulation of SNHG1 was found to inhibit BC growth. Through the inhibition of the miR-641 level, SNHG1 elevated the level of the downstream target RRS1, thereby fostering BC growth, migration, and invasion while inhibiting apoptosis. These findings suggest that SNHG1 may represent a potential therapeutic target for BC treatment.

MiRNA-449c-5p regulates the JAK-STAT pathway in inhibiting cell proliferation and invasion in human breast cancer cells by targeting ERBB2.

Breast cancer is a highly prevalent disease worldwide, and early diagnosis and treatment could reduce the mortality rate of breast cancer patients. microRNAs (miRNA) have been shown to regulate the occurrences and progression of many types of cancers. Thus, it is crucial to find novel biomarkers in breast cancer. miR-449c-5p acted as a biomarker in non-small cell lung cancer, gastric carcinoma, and so forth. ERBB2 is an ideal target for breast cancer therapy. However, the molecular mechanisms between miR-449c-5p and ERBB2 in breast cancer remain poorly understood. Our study focused on the regulatory role of miR-449c-5p in breast cancer and its targeting relationship with ERBB2. The miR-449c-5p expression in breast cancer tissue and normal tissue was searched from the online database (Starbase). The clinical prognosis of miR-449c-5p and ERBB2 was predicted by using the Kaplan-Meier analysis method. The expression of miR-449c-5p mimics and inhibitors was measured by qRT-PCR. T47D cells were transfected with miR-449c-5p mimics and miR-449c-5p inhibitors. After that, CCK-8, colony formation assays and Transwell assays were used to evaluate the cell proliferation ability, migration and invasion. Whether ERBB2 was the target gene of the miR-449c-5p was predicted by Starbase and verified by dual-luciferase activity assay. In addition, protein levels and the relationship between signalling pathways were measured and validated using western blotting analysis. We confirmed that miR-449c-5p was highly expressed in breast cancer tissue, and its downregulation was linked with poor prognosis. Overexpression of miR-449c-5p inhibited the proliferation, migration and invasion of breast cancer cells. ERBB2 was a target of miR-449c-5p. The invasion, migration, and proliferation of breast cancer cells were inhibited by miR-449c-5p/ERBB2 through JAK-STAT. This study demonstrated that miR-449c-5p inhibits breast cancer cell proliferation, migration and invasion by targeting ERBB2 via JAK/STAT, which means miR-449c-5p, is a potential biomarker for breast cancer and provides a novel insight for diagnosis.

Engineering Iron-Based Nanomaterials for Breast Cancer Therapy Associated with Ferroptosis.

Ferroptosis has received increasing attention as a novel nonapoptotic programmed death. Recently, iron-based nanomaterials have been extensively exploited for efficient tumor ferroptosis therapy, as they directly release high concentrations of iron and increase intracellular reactive oxygen species levels. Breast cancer is one of the commonest malignant tumors in women; inhibiting breast cancer cell proliferation through activating the ferroptosis pathway could be a potential new target for patient treatment. Here, we briefly introduce the background of ferroptosis and systematically review the current cancer therapeutic strategies based on iron-based ferroptosis inducers. Finally, we summarize the advantages of these various ferroptosis inducers and shed light on future perspectives. This review aims to provide better guidance for the development of iron-based nanomaterial ferroptosis inducers.

Exploration of MELK as a downstream of Del-1 and druggable targets in triple-negative breast cancer.

In our previous study, Developmental endothelial locus-1 (Del-1) was a promising predictive marker for breast cancer. However, the downstream targets of Del-1 remain unknown. Here, we sought to discover a druggable target downstream of Del-1 and investigate the mechanism by which it regulates the course of breast cancer. To investigate Del-1 downregulation effect on breast cancer, we performed transcriptome analysis using RNA sequencing of Del-1 knockdowned MDA-MB-231 cell line Plus, to investigate the expression of Del-1 and Maternal embryonic leucine zipper kinase (MELK), mRNA levels in eight different triple-Negative Breast Cancer (TNBC) cell lines were analyzed. High-throughput sequencing was performed on total RNA isolated. OTS167 was used for MELK inhibition. The effects of MELK on cell proliferation and invasion were determined using the MTT and Matrigel transwell assays. Furthermore, we examined MELK expression in breast cancer tissue. Del-1 and MELK mRNA expression levels were significantly higher in the TNBC cell lines, MDA-MB-468, HCC-1806, and MBA-MB-231. Knocking down Del-1 with siRNA in HCC-1806 and MBA-MB-231 cells significantly decreased MELK expression and thus suggested a possible relationship between Del-1 and MELK. In MDA-MB-468 cells, a basal-like 1 TNBC cell line, OTS167 significantly inhibited breast cancer cell proliferation and promoted cell apoptosis. To further investigate the relationship between Del-1 and MELK, dual inhibition of both Del-1 and MELK was performed, which significantly reduced the viability of MDA-MB-468 and MBA-MB-231 cells. We found that MELK acts downstream of Del-1 and is a promising druggable target, especially in basal-like and mesenchymal stem-like subtype.

The integration of multidisciplinary approaches revealed PTGES3 as a novel drug target for breast cancer treatment

BackgroundThe main challenge in personalized treatment of breast cancer (BC) is how to integrate massive amounts of computing resources and data. This study aimed to identify a novel molecular target that might be effective for BC prognosis and for targeted therapy by using network-based multidisciplinary approaches.MethodsDifferentially expressed genes (DEGs) were first identified based on ESTIMATE analysis. A risk model in the TCGA-BRCA cohort was constructed using the risk score of six DEGs and validated in external and clinical in-house cohorts. Subsequently, independent prognostic factors in the internal and external cohorts were evaluated. Cell viability CCK-8 and wound healing assays were performed after PTGES3 siRNA was transiently transfected into the BC cell lines. Drug prediction and molecular docking between PTGES3 and drugs were further analyzed. Cell viability and PTGES3 expression in two BC cell lines after drug treatment were also investigated.ResultsA novel six-gene signature (including APOOL, BNIP3, F2RL2, HINT3, PTGES3 and RTN3) was used to establish a prognostic risk stratification model. The risk score was an independent prognostic factor that was more accurate than clinicopathological risk factors alone in predicting overall survival (OS) in BC patients. A high risk score favored tumor stage/grade but not OS. PTGES3 had the highest hazard ratio among the six genes in the signature, and its mRNA and protein levels significantly increased in BC cell lines. PTGES3 knockdown significantly inhibited BC cell proliferation and migration. Three drugs (gedunin, genistein and diethylstilbestrol) were confirmed to target PTGES3, and genistein and diethylstilbestrol demonstrated stronger binding affinities than did gedunin. Genistein and diethylstilbestrol significantly inhibited BC cell proliferation and reduced the protein and mRNA levels of PTGES3.ConclusionsPTGES3 was found to be a novel drug target in a robust six-gene prognostic signature that may serve as a potential therapeutic strategy for BC.

Apolipoprotein L3 inhibits breast cancer proliferation and modulates cell cycle via the P53 pathway.

Background: Breast cancer is the second most common cause of cancer-related mortality globally. Apolipoprotein L3 (APOL3), a member of the apolipoprotein family, has been implicated in the pathogenesis of cardiovascular diseases. Nevertheless, the functions and underlying mechanisms of APOL3 in breast cancer have yet to be elucidated. Methods: The patient data were sourced from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. Quantitative real-time PCR (qRT-PCR), western blotting, and immunohistochemistry (IHC) assays were used to assess expression of APOL3. Cell proliferation rates were determined by Cell Counting Kit-8 (CCK-8) and colony formation assays. Flow cytometry was used to examine cell cycle distribution. Western blotting was conducted to investigate the expression of cell cycle related proteins. A xenograft model was used to evaluate the effect of APOL3 in vivo. APOL3-binding proteins were identified through mass spectrometry, co-immunoprecipitation (CO-IP) assay and immunofluorescence assay. Results: APOL3 expression was significantly downregulated in breast cancer, and its low expression was correlated with poor prognostic outcomes. Overexpression of APOL3 suppressed breast cancer cell proliferation, induced cell cycle disruption. Conversely, knockdown of APOL3 promoted cell proliferation. In vivo animal experiments demonstrated that APOL3 overexpression can inhibit tumor proliferation. Mass spectrometry, CO-IP and immunofluorescence assay confirmed the interaction between APOL3 and Y-box binding protein 1 (YBX1). Furthermore, YBX1 knockdown following APOL3 knockdown mitigated the enhanced proliferation. These results provide new ideas for clinically targeting APOL3 to inhibit proliferation in breast cancer. Conclusions: Our findings indicate that APOL3 inhibits breast cancer cell proliferation and cell cycle modulating P53 pathway through the interaction of YBX1.

Nitro Compounds Inhibit Breast Cancer Cell Proliferation, Migration, and Colony Formation: Molecular Docking, Molecular Dynamics Simulations and Pharmacological Properties

AbstractIn this study, the concept of combined in vitro and in silico studies were utilized by using some synthesized nitro bearing compounds. The anticancer activities of the studied compounds were performed by using colony formation analysis, cell cytotoxicity, and migration. Nitro group containing two compounds were analyzed using Hoechst staining to indicate the morphological changes on the nuclei of cancer cells under fluorescence microscopy. Scanning electron microscopy (SEM) analysis was performed with N,N‐dibutyl‐nitro‐substituted compound. Nitro containing anticancer agents were shown the inhibition at 1.5 μM and 2 μM concentrations, and nuclear apoptosis was detected. In addition, cell‐to‐cell interaction on MDA‐MB‐231 cells was broken and observed morphologic changes following the treatment with N,N‐dibutyl‐nitro‐substituted compound at the effective doses. In general, the other nitro compounds showed cell cytotoxicity at 5 μM, 10 μM, and 20 μM. Two hits as anticancer agents were determined as potential interleukin‐1 receptor‐associated kinase 1 (IRAK1) and interleukin‐1 receptor‐associated kinase 4 (IRAK4) inhibitor candidates. Molecular docking and molecular dynamics (MD) simulations studies will provide that the binding patterns with specific residues such as Met265, Tyr284 of the IRAK family members, and these will contribute to further in vitro and in vivo studies for targeted breast cancer therapy.

Pigmented Microbial Extract (PMB) from Exiguobacterium Species MB2 Strain (PMB1) and Bacillus subtilis Strain MB1 (PMB2) Inhibited Breast Cancer Cells Growth In Vivo and In Vitro.

Breast cancer (BC) continues to be one of the major causes of cancer deaths in women. Progress has been made in targeting hormone and growth factor receptor-positive BCs with clinical efficacy and success. However, little progress has been made to develop a clinically viable treatment for the triple-negative BC cases (TNBCs). The current study aims to identify potent agents that can target TNBCs. Extracts from microbial sources have been reported to contain pharmacological agents that can selectively inhibit cancer cell growth. We have screened and identified pigmented microbial extracts (PMBs) that can inhibit BC cell proliferation by targeting legumain (LGMN). LGMN is an oncogenic protein expressed not only in malignant cells but also in tumor microenvironment cells, including tumor-associated macrophages. An LGMN inhibition assay was performed, and microbial extracts were evaluated for in vitro anticancer activity in BC cell lines, angiogenesis assay with chick chorioallantoic membrane (CAM), and tumor xenograft models in Swiss albino mice. We have identified that PMB from the Exiguobacterium (PMB1), inhibits BC growth more potently than PMB2, from the Bacillus subtilis strain. The analysis of PMB1 by GC-MS showed the presence of a variety of fatty acids and fatty-acid derivatives, small molecule phenolics, and aldehydes. PMB1 inhibited the activity of oncogenic legumain in BC cells and induced cell cycle arrest and apoptosis. PMB1 reduced the angiogenesis and inhibited BC cell migration. In mice, intraperitoneal administration of PMB1 retarded the growth of xenografted Ehrlich ascites mammary tumors and mitigated the proliferation of tumor cells in the peritoneal cavity in vivo. In summary, our findings demonstrate the high antitumor potential of PMB1.

The p53/ZEB1-PLD3 feedback loop regulates cell proliferation in breast cancer

Breast cancer is the most prevalent cancer globally, endangering women’s physical and mental health. Phospholipase D3 (PLD3) belongs to the phosphodiesterase family (PLD). PLD3 is related to insulin-mediated phosphorylation of the AKT pathway, suggesting that it may play a role in the occurrence and development of malignant tumors. This study may further explore the molecular mechanism of PLD3 inhibiting breast cancer cell proliferation. In this study, we demonstrated that PLD3 and miR-6796 are co-expressed in breast cancer. PLD3 can bind with CDK1 and inhibit its expression, leading to mitotic arrest and inhibiting breast cancer proliferation. Wild-type p53 regulates PLD3 and miR-6796 expression by competitively binding to the PLD3 promoter with ZEB1. DNMT3B, as the target gene of miR-6796, is recruited into the PLD3 promoter by combining with ZEB1 to regulate the DNA methylation of the PLD3 promoter and ultimately affect PLD3 and miR-6796 expression. In conclusion, we revealed the role and molecular mechanism of PLD3 and its embedded miR-6796 in breast cancer proliferation, providing clues and a theoretical foundation for future research and development of therapeutic targets and prognostic markers for breast cancer.

Circ_0001982 aggravates breast cancer development through the circ_0001982-miR-144-3p-GSE1 axis.

This study was designed to explore the role of circ_0001982 in breast cancer (BC) development.Quantitative real-time polymerase chain reaction and western blot analysis assays were used to determine circ_0001982, miR-144-3p, and gse1 coiled-coil protein (GSE1) expression. Functional assays were performed to evaluate cell proliferation, apoptosis, migration, and invasion. The glycolysis was analyzed with commercial kits. Dual-luciferase reporter assay and RNA immunoprecipitation assays were conducted to analyze the relationships among circ_0001982, miR-144-3p, and GSE1. A murine xenograft model assay was performed to determine circ_0001982-induced effects on BC cell tumor properties in vivo.Circ_0001982 expression was upregulated, but miR-144-3p was reduced in BC tissues and cells in comparison with normal breast tissues and normal human mammary epithelial cells. Circ_0001982 knockdown or miR-144-3p overexpression inhibited BC cell proliferation, glycolysis, migration and invasion, and promoted apoptosis. Circ_0001982 sponged miR-144-3p and negatively regulated miR-144-3p expression in BC cells. In addition, GSE1 was identified as a target mRNA of miR-144-3p. Ectopic GSE1 expression relieved circ_0001982 depletion-induced effects on BC cell tumor properties. Furthermore, circ_0001982 absence suppressed BC cell tumor properties in vivo.Circ_0001982 contributed to the BC cell tumor properties by regulating the miR-144-3p-GSE1 axis.

Circular RNA AGFG1 motivates breast cancer cell proliferation, invasion, migration, and glycolysis by controlling microRNA-653-5p/14-3-3 protein epsilon.

A recent Pairwise meta-analysis confirmed that circular RNA AGFG1 (circAGFG1) is abnormally highly expressed in breast cancer (BC) and may be associated with death risk. The purpose of this study was to elucidate the biological role of circAGFG1 in BC and to explore its potential downstream molecular mechanisms. CircAGFG1, miR-653-5p and YWHAE expression in BC tissues and cells were analyzed by RT-qPCR or western blot. Gene expression was regulated by transfection of plasmids or oligonucleotides and the biological behaviors of BC cells were analyzed by a series of assays. The ring structure of circAGFG1 was analyzed by RNase R and actinomycin D treatment. Dual luciferase reporter assay and RNA-pull down were used to verify the targeting relationship of circAGFG1 and downstream factors. A nude mouse xenograft experiment was performed to verify the effect of circAGFG1 on cancer cells in vivo. The results showed that circAGFG1 and YWHAE were highly expressed in BC while miR-653-5p was lowly expressed. Both circAGFG1 and YWHAE had a targeting relationship with miR-653-5p. Knockdown of circAGFG1 inhibited BC cell proliferation, invasion, migration, and glycolysis. The inhibitory effect of circAGFG1 knockdown on BC was reversed by silencing miR-653-5p. The inhibitory effect of overexpression of miR-653-5p on malignant behaviors of BC cells was reversed by overexpression of YWHAE. Knockdown of circAGFG1 inhibited tumor growth in vivo. Taken together, these data suggest that circAGFG1 acts as a sponge for miR-653-5p to mediate YWHAE expression to promote the malignant behaviors of BC.

Autophagy induction using Resveratrol enhances the anti-cancer efficacy of Doxazosin in breast cancer cells.

The combination of anti-cancer drugs improves effectiveness compared to the mono-therapy scenario by targeting key pathways synergistically or in an additive way. Doxazosin (DOX) and Resveratrol (RES) are reported to have an anti-cancer impact against different cancer cells. Aim: To evaluate the anti-cancer properties of Doxazosin and Resveratrol, each alone or in combination, in inhibiting breast cancer cell proliferation. Methods: MCF-7 cancer cells were seeded to a confluent monolayer and treated with 100, 50, 25, 12.5, 6.25, and 3.12 µM of each drug alone and as a combination. Cytotoxicity was evaluated using dimethyl thiazolyl diphenyl tetrazolium salt (MTT) assay and colony formation assay. The immunocytochemistry technique was conducted to evaluate caspase-3 and GABARAP expression. Results: All the drugs have a significant effect on cancer cell proliferation. The combination treatment of Doxazosin-Resveratrol has a more cytotoxic effect than each drug alone, as well as in colony formation of MCF-7 cancer cells. In combination treatment, caspase-3 had a higher expression pattern than other treatments. Resveratrol treatment elevated GABARAP expression in cancer cells, indicating the induction of the autophagy process. Conclusion: Although each drug has its characteristic result of a cytotoxic effect, the combination of Doxazosin and Resveratrol synergizes the inhibition of MCF-7 cancer cell proliferation. Keywords: Resveratrol; Doxazosin; combination; MCF-7; Autophagy.

Molecular Evidence of Breast Cancer Cell Proliferation Inhibition by a Combination of Selected Qatari Medicinal Plants Crude Extracts.

Breast cancer (BC) is the most common malignancy, and conventional medicine has failed to establish efficient treatment modalities. Conventional medicine failed due to lack of knowledge of the mechanisms that underpin the onset and metastasis of tumors, as well as resistance to treatment regimen. However, Complementary and Alternative medicine (CAM) modalities are currently drawing the attention of both the public and health professionals. Our study examined the effect of a super-combination (SC) of crude extracts, which were isolated from three selected Qatari medicinal plants, on the proliferation, motility and death of BC cells. Our results revealed that SC attenuated cell growth and caused the cell death of MDA-MB-231 cancer cells when compared to human normal neonatal fibroblast cells. On the other hand, functional assays showed that SC reduced BC cell migration and invasion, respectively. SC-inhibited cell cycle and SC-regulated apoptosis was most likely mediated by p53/p21 pathway and p53-regulated Bax/BCL-2/Caspace-3 pathway. Our ongoing experiments aim to validate these in vitro findings in vivo using a BC-Xenograft mouse model. These findings support our hypothesis that SC inhibited BC cell proliferation and induced apoptosis. These findings lay the foundation for further experiments, aiming to validate SC as an effective chemoprevention and/or chemotherapeutic strategy that can ultimately pave the way towards translational research/clinical trials for the eradication of BC.

UBE3B promotes breast cancer progression by antagonizing HIF-2α degradation.

Mutations in E3 ubiquitin ligase UBE3B have been linked to Kaufman Oculocerebrofacial Syndrome (KOS). Accumulating evidence indicates that UBE3B may play an important role in cancer. However, the precise role of UBE3B in cancer and the underlying mechanism remain largely uncharted. Here, we reported that UBE3B is an E3 ligase for hypoxia-inducible factor 2α (HIF-2α). Mechanically, UBE3B physically interacts with HIF-2α and promotes its lysine 63 (K63)-linked polyubiquitination, thereby inhibiting the Von Hippel-Lindau (VHL) E3 ligase complex-mediated HIF-2α degradation. UBE3B depletion inhibits breast cancer cell proliferation, colony formation, migration, and invasion in vitro and suppresses breast tumor growth and lung metastasis in vivo. We further identified K394, K497, and K503 of HIF-2α as key ubiquitination sites for UBE3B. K394/497/503R mutation of HIF-2α dramatically abolishes UBE3B-mediated breast cancer growth and lung metastasis. Intriguingly, the protein levels of UBE3B are upregulated and positively correlated with HIF-2α protein levels in breast cancer tissues. These findings uncover a critical mechanism underlying the role of UBE3B in HIF-2α regulation and breast cancer progression.

The HDAC inhibitor HFY-4A improves TUSC2 transcription to induce immunogenic cell death in breast cancer

We managed to explore the function of HFY-4A, a novel histone deacetylases (HDACs) inhibitor, on breast cancer as well as its potential mechanisms. MCF7 and T47D cells were treated with 0.8, 1.6 or 3.2 μM HFY-4A for 0–72 h, following of which CCK-8, colony formation, EdU staining, flow cytometry, Transwell, and wound healing assays were carried out. Western blot, immunohistochemistry, and ELISA were conducted for assaying the expression of immunogenic cell death (ICD)-related proteins. The interaction between HFY-4A, HDAC1, and tumor suppressor candidate 2 (TUSC2) was evaluated by chromatin immunoprecipitation assay. Further, the function of HFY-4A in breast cancer progression in vivo was evaluated using xenograft mouse models. HFY-4A inhibited the proliferation, migration, and invasion, and induced apoptosis of breast cancer cells in a dose-dependent manner. HFY-4A dose-dependently caused the ICD of breast cancer cells, as evidenced by the significant high levels of high-mobility group box 1 (HMGB1), calreticulin (CRT), heat shock protein 70 (HSP70), and HSP90. Interestingly, HFY-4A could facilitate TUSC2 transcription by promoting acetylation of histones on the TUSC2 promoter. The results of rescue assays revealed that HFY-4A repressed proliferation and mobility, but enhanced apoptosis and ICD through facilitating TUSC2 transcription in breast cancer. In breast cancer xenograft mouse models, HFY-4A was verified to inhibit tumor growth via upregulating TUSC2. HFY-4A could inhibit breast cancer cell proliferation and mobility, and enhanced apoptosis and ICD through facilitating TUSC2 transcription.