Propofol Reduced Mammosphere Formation of Breast Cancer Stem Cells via PD-L1/Nanog In Vitro

Propofol reduces breast cancer cell stemness via FOXO3/SOX2 axis

Objective: Propofol is a common intravenous anesthetic in cancer resection surgery, which is considered to exhibit anti-tumor effect in various cancer types. This study was aimed at investigating the role and mechanism of propofol in breast cancer stemness and proliferation. Methods: The breast cancer cells with propofol treatment were sequenced. The expression of FOXO3 in propofol treated cells was detected by RT-qPCR and Western blot. The CSC properties were analyzed by screen cells with ESA+CD44+CD24-/low through flow cytometry and the proliferation capacity were also detected. The expression correlation of FOXO3 and target genes were detected by western blot. The potential binding site of FOXO3 on SOX2 was predicted by JASPAR and verified by dual-luciferase reporter assay and ChIP assay. Results: FOXO3 was found to be upregulated in propofol 24h-treated cells. Propofol could inhibit the capacity of breast cancer cell stemness and proliferation by upregulation FOXO3, which inhibited SOX2 expression transcriptionally. Conclusion: In this study, we uncovered the role of propofol-FOXO3-SOX2 in breast cancer cell stemness and proliferation, which might serve as potential targets for breast cancer therapy.

High CTLA-4 gene expression is an independent good prognosis factor in breast cancer patients, especially in the HER2-enriched subtype

BACKGROUND

Breast cancer (BC) is the most common cancer in women and the leading cause of cancer-related death worldwide. This heterogeneous disease has been historically considered a non-immunogenic type of cancer. However, recent advances in immunotherapy have increased the interest in knowing the role of the immune checkpoints (IC) and other immune regulation pathways in this neoplasia.

METHODS

In this retrospective study, we evaluated the correlation of mRNA expression of CTLA-4, PDCD1 (PD1), CD274 (PD-L1), PDCD1LG2 (PD-L2), CD276 (B7-H3), JAK2, and FOXO1 with clinicopathological factors and BC patient's outcome by real-time quantitative polymerase chain reaction (qPCR).

RESULTS

Our results showed that immunoregulatory gene expression depends on BC immunophenotype being CTLA-4 and PDCD1 (PD1) overexpressed on triple-negative/basal-like (TN/BL) and luminal B/HER2-positive phenotypes, respectively, and CD276 (B7-H3), JAK2 and FOXO1 associated with both luminal A and luminal B/HER2-negative tumors. In addition, we found that these genes can also be related to aggressive and non-aggressive clinicopathological characteristics in BC. Finally, survival analysis showed that CTLA-4 expression levels emerge as a significant independent factor of good prognosis in BC patients, especially in the HER2-enriched subtype.

CONCLUSION

Considering all these data, we can conclude that the expression of immunoregulatory genes depends on tumor phenotype and has potential clinical implications in BC patients.

Propofol inhibits colon cancer cell stemness and epithelial-mesenchymal transition by regulating SIRT1, Wnt/β-catenin and PI3K/AKT/mTOR signaling pathways

BACKGROUND

Propofol is a common sedative-hypnotic drug used for general anesthesia. Recent studies have drawn attention to the antitumor effects of propofol, but the potential mechanism by which propofol suppresses colon cancer stemness and epithelial-mesenchymal transition (EMT) has not been fully elucidated.

METHODS

For the in vitro experiments, we used propofol to treat LOVO and SW480 cells and Cell Counting Kit-8 (CCK-8) to detect proliferation. Self-renewal capacity, cell invasion and migration, flow cytometry analysis, qPCR and Western blotting were performed to detect the suppression of propofol to colon cancer cells and the underlying mechanism. Tumorigenicity and immunohistochemistry experiments were performed to confirm the role of propofol in vivo.

RESULT

We observed that propofol could suppressed stem cell-like characteristics and EMT-related behaviors, including self-renewal capacity, cell invasion and migration in colon cancer cells, and even suppressed tumorigenicity in vivo. Furthermore, investigations of the underlying mechanism revealed that propofol treatment downregulated SIRT1. SIRT1 overexpression or knockdown affected the stemness and EMT of colon cancer cells. Additionally, propofol reversed stemness and EMT in cells with overexpressing SIRT1 and subsequently inhibited the Wnt/β-catenin and PI3K/AKT/mTOR signaling pathways. Wnt/β-catenin pathway inhibitor and PI3K/AKT/mTOR pathway inhibitor blocked the propofol-induced reduction of sphere-formation and cell invasion-migration.

CONCLUSION

Propofol inhibits LOVO and SW480 cell stemness and EMT by regulating SIRT1 and the Wnt/β-catenin and PI3K/AKT/mTOR signaling pathways. Our findings indicate that propofol inhibits SIRT1 in cancer and is advantageous in colon cancer surgical treatment of patients with high SIRT1 expression.

Activated Carbon nanoparticles Loaded with Metformin for Effective Against Hepatocellular Cancer Stem Cells

Introduction

Hepatocellular cancer stem cells (CSCs) play crucial roles in hepatocellular cancer initiation, development, relapse, and metastasis. Therefore, eradication of this cell population is a primary objective in hepatocellular cancer therapy. We prepared a nanodrug delivery system with activated carbon nanoparticles (ACNP) as carriers and metformin (MET) as drug (ACNP-MET), which was able to selectively eliminate hepatocellular CSCs and thereby increase the effects of MET on hepatocellular cancers.

Methods

ACNP were prepared by ball milling and deposition in distilled water. Suspension of ACNP and MET was mixed and the best ratio of ACNP and MET was determined based on the isothermal adsorption formula. Hepatocellular CSCs were identified as CD133⁺ cells and cultured in serum-free medium. We investigated the effects of ACNP-MET on hepatocellular CSCs, including the inhibitory effects, the targeting efficiency, self-renewal capacity, and the sphere-forming capacity of hepatocellular CSCs. Next, we evaluated the therapeutic efficacy of ACNP-MET by using in vivo relapsed tumor models of hepatocellular CSCs.

Results

The ACNP have a similar size, a regular spherical shape and a smooth surface. The optimal ratio for adsorption was MET: ACNP=1:4. ACNP-MET could target and inhibit the proliferation of CD133⁺ population and decrease mammosphere formation and renewal of CD133⁺ population in vitro and in vivo.

Conclusion

These results not only suggest that nanodrug delivery system increased the effects of MET, but also shed light on the mechanisms of the therapeutic effects of MET and ACNP-MET on hepatocellular cancers. ACNP, as a good nano-carrier, could strengthen the effect of MET by carrying drugs to the micro-environment of hepatocellular CSCs.

Targeting Breast Cancer Stem Cells

The potential roles of breast cancer stem cells (BCSCs) in tumor initiation and recurrence have been recognized for many decades. Due to their strong capacity for self-renewal and differentiation, BCSCs are the major reasons for poor clinical outcomes and low therapeutic response. Several hypotheses on the origin of cancer stem cells have been proposed, including critical gene mutations in stem cells, dedifferentiation of somatic cells, and cell plasticity remodeling by epithelial-mesenchymal transition (EMT) and the tumor microenvironment. Moreover, the tumor microenvironment, including cellular components and cytokines, modulates the self-renewal and therapeutic resistance of BCSCs. Small molecules, antibodies, and chimeric antigen receptor (CAR)-T cells targeting BCSCs have been developed, and their applications in combination with conventional therapies are undergoing clinical trials. In this review, we focus on the features of BCSCs, emphasize the major factors and tumor environment that regulate the stemness of BCSCs, and discuss potential BCSC-targeting therapies.

An intravenous anesthetic drug-propofol, influences the biological characteristics of malignant tumors and reshapes the tumor microenvironment: A narrative literature review

Malignant tumors are the second leading cause of death worldwide. This is a public health concern that negatively impacts human health and poses a threat to the safety of life. Although there are several treatment approaches for malignant tumors, surgical resection remains the primary and direct treatment for malignant solid tumors. Anesthesia is an integral part of the operation process. Different anesthesia techniques and drugs have different effects on the operation and the postoperative prognosis. Propofol is an intravenous anesthetic that is commonly used in surgery. A substantial number of studies have shown that propofol participates in the pathophysiological process related to malignant tumors and affects the occurrence and development of malignant tumors, including anti-tumor effect, pro-tumor effect, and regulation of drug resistance. Propofol can also reshape the tumor microenvironment, including anti-angiogenesis, regulation of immunity, reduction of inflammation and remodeling of the extracellular matrix. Furthermore, most clinical studies have also indicated that propofol may contribute to a better postoperative outcome in some malignant tumor surgeries. Therefore, the author reviewed the chemical properties, pharmacokinetics, clinical application and limitations, mechanism of influencing the biological characteristics of malignant tumors and reshaping the tumor microenvironment, studies of propofol in animal tumor models and its relationship with postoperative prognosis of propofol in combination with the relevant literature in recent years, to lay a foundation for further study on the correlation between propofol and malignant tumor and provide theoretical guidance for the selection of anesthetics in malignant tumor surgery.

Midazolam exhibits antitumour and enhances the efficiency of Anti-PD-1 immunotherapy in hepatocellular carcinoma

BACKGROUND

Midazolam (MDZ) is an anaesthetic that is widely used for anxiolysis and sedation. More recently, MDZ has also been described to be related to the outcome of various types of carcinomas. However, how MDZ influences the progression of hepatocellular carcinoma (HCC) and its effects on the biological function and tumour immune microenvironment of this type of tumour remain unknown.

METHODS

The effects of MDZ on the proliferation, invasion, and migration of HCC cell lines were examined in vitro using the Cell Counting Kit 8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), Transwell, and wound healing assays. Additionally, western blotting was employed to confirm that PD-L1 was expressed. Chromatin immunoprecipitation-seq (ChIP-seq) analysis was used to pinpoint the transcriptional regulation regions of NF-κB and programmed death-ligand 1 (PD-L1). A C57BL/6 mouse model was used to produce subcutaneous HCC tumors in order to evaluate the in vivo performance of MDZ. Mass spectrometry was also used to assess changes in the tumour immunological microenvironment following MDZ injection.

RESULTS

The HCC-LM3 and Hep-3B cell lines' proliferation, invasion, and migration were controlled by MDZ, according to the results of the CCK8, EdU, Transwell, and wound healing assays. PD-L1 expression was shown by ChIP-seq analysis to be boosted by NF-κB, and by Western blotting analysis, it was shown that MDZ downregulated the expression of NF-κB. Additionally, in vivo tests revealed that intraperitoneal MDZ injections reduced HCC tumor development and enhanced the effectiveness of anti-PD-1 therapy. The CD45⁺ immune cell proportions were higher in the MDZ group than in the PBS group, according to the mass spectrometry results. Injection of MDZ resulted in a decrease in the proportions of CD4⁺ T cells, CD8⁺ T cells, natural killer (NK) cells, monocytes, Tregs, and M2 macrophages and a rise in the proportion of dendritic cells. Additionally, the concentrations of the cytokines IFN-g and TNF-a were noticeably raised whereas the concentrations of the CD8⁺ T-cell fatigue markers ICOS, TIGIT, and TIM3 were noticeably lowered.

CONCLUSION

According to this study, MDZ inhibited the progression of HCC by inhibiting the NF-κB pathway and reducing the exhaustion of CD8⁺ T cells. In clinical practice, MDZ combined with anti-PD-1 therapy might contribute to synergistically improving the antitumor efficacy of HCC treatment.

The inhibition of circular RNA circNOLC1 by propofol/STAT3 attenuates breast cancer stem cells function via miR-365a-3p/STAT3 signaling

Background

Breast cancer remains one of the most dreadful female malignancies globally, in which cancer stem cells (CSCs) play crucial functions. Circular RNAs have drawn great attention in cancer research area and propofol is a widely applied intravenous anesthetic agent. Methods: In the current study, we explored the function of circular RNA nucleolar and coiled-body phosphoprotein 1 (circNOLC1) in CSCs of breast cancer and the inhibitory impact of propofol on circNOLC1.

Results

The expression of circNOLC1 was induced in breast cancer tissues compared with the non-tumor tissues. The silencing of circNOLC1 was able to repress the viability of breast cancer cells. Meanwhile, the numbers of colony formation were suppressed by circNOLC1 knockdown in breast cancer cells. The inhibition of circNOLC1 reduced the invasion and migration ability of breast cancer cells. The mRNA and protein levels of E-cadherin were enhanced but Vimentin levels were reduced by the silencing of circNOLC1. The repression of circNOLC1 decreased the side population (SP) ratio in breast cancer cells. Meanwhile, the sphere formation ability of breast cancer cells was attenuated by the silencing of circNOLC1. The levels of ATP-binding cassette (ABC) superfamily G member 2 (ABCG2), c-Myc, B cell-specific Moloney murine leukemia virus integration site 1 (Bmi1), and SRY-box transcription factor 2 (Sox2) were repressed by the depletion of circNOLC1 in the cells. Regarding to the mechanism, circNOLC1 functioned as a competing endogenous RNAs (ceRNAs) for microRNA-365a-3p (miR-365a-3p) and the inhibition of miR-365a-3p rescued circNOLC1 depletion-repressed proliferation and cancer stem cell activity of breast cancer. MiR-365a-3p targeted signal transducer and activator of transcription 3 (STAT3) in breast cancer cells and circNOLC1 enhanced STAT3 expression by sponging miR-365a-3p. The overexpression of STAT3 could reverse miR-365a-3p or circNOLC1 depletion-inhibited proliferation and cancer stem cell properties of breast cancer. Interestingly, the expression of circNOLC1 and STAT3 was repressed by the treatment of propofol. The enrichment of STAT3 on circNOLC1 promoter was inhibited by propofol. The expression of circNOLC1 was suppressed by the silencing of STAT3 in the cells. The inhibition of circNOLC1 expression by propofol was rescued under the co-treatment of STAT3 overexpression. The overexpression of circNOLC1 rescued propofol-attenuated proliferation and cancer stem cell functions in vitro and in vivo.

Conclusions

Thus, we concluded that circNOLC1 contributes to CSCs properties and progression of breast cancer by targeting miR-365a-3p /STAT3 axis and propofol inhibited circNOLC1 by repressing STAT3 in a feedback mechanism.

Current understanding of cancer-intrinsic PD-L1: regulation of expression and its protumoral activity

In the last decade, we have witnessed an unprecedented clinical success in cancer immunotherapies targeting the programmed cell-death ligand 1 (PD-L1) and programmed cell-death 1 (PD-1) pathway. Besides the fact that PD-L1 plays a key role in immune regulation in tumor microenvironment, recently a plethora of reports has suggested a new perspective of non-immunological functions of PD-L1 in the regulation of cancer intrinsic activities including mesenchymal transition, glucose and lipid metabolism, stemness, and autophagy. Here we review the current understanding on the regulation of expression and intrinsic protumoral activity of cancer-intrinsic PD-L1.

Anti-tumor Activity of Propofol: A Focus on MicroRNAs

BACKGROUND

MicroRNAs are endogenous, short, non-coding RNAs with the length as low as 20 to 25 nucleotides. These RNAs are able to negatively affect the gene expression at the post-transcriptional level. It has been demonstrated that microRNAs play a significant role in cell proliferation, cell migration, cell death, cell differentiation, infection, immune response, and metabolism. Besides, the dysfunction of microRNAs has been observed in a variety of cancers. So, modulation of microRNAs is of interest in the treatment of disorders.

OBJECTIVE

The aim of the current review is to investigate the modulatory effect of propofol on microRNAs in cancer therapy.

METHODS

This review was performed at PubMed, SCOPUS and Web of Science data-bases using keywords "propofol', "microRNA", "cancer therapy", "propofol + microRNA" and "propofol + miR".

RESULTS

It was found that propofol dually down-regulates/upregulates microRNAs to exert its antitumor activity. In terms of oncogenesis microRNAs, propofol exert an inhibitory effect, while propofol significantly enhances the expression of oncosuppressor microRNAs.

CONCLUSION

It seems that propofol is a potential modulator of microRNAs and this capability can be used in the treatment of various cancers.

Identification of potential therapeutic target of naringenin in breast cancer stem cells inhibition by bioinformatics and in vitro studies

Cancer therapy is a strategic measure in inhibiting breast cancer stem cell (BCSC) pathways. Naringenin, a citrus flavonoid, was found to increase breast cancer cells' sensitivity to chemotherapeutic agents. Bioinformatics study and 3D tumorsphere in vitro modeling in breast cancer (mammosphere) were used in this study, which aims to explore the potential therapeutic targets of naringenin (PTTNs) in inhibiting BCSCs. Bioinformatic analyses identified direct target proteins (DTPs), indirect target proteins (ITPs), naringenin-mediated proteins (NMPs), BCSC regulatory genes, and PTTNs. The PTTNs were further analyzed for gene ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, protein-protein interaction (PPI) networks, and hub protein selection. Mammospheres were cultured in serum-free media. The effects of naringenin were measured by MTT-based cytotoxicity, mammosphere forming potential (MFP), colony formation, scratch wound-healing assay, and flow cytometry-based cell cycle analyses and apoptosis assays. Gene expression analysis was performed using real-time quantitative polymerase chain reaction (q-RT PCR). Bioinformatics analysis revealed p53 and estrogen receptor alpha (ERα) as PTTNs, and KEGG pathway enrichment analysis revealed that TGF-ß and Wnt/ß-catenin pathways are regulated by PTTNs. Naringenin demonstrated cytotoxicity and inhibited mammosphere and colony formation, migration, and epithelial to mesenchymal transition in the mammosphere. The mRNA of tumor suppressors P53 and ERα were downregulated in the mammosphere, but were significantly upregulated upon naringenin treatment. By modulating the P53 and ERα mRNA, naringenin has the potential of inhibiting BCSCs. Further studies on the molecular mechanism and formulation of naringenin in BCSCs would be beneficial for its development as a BCSC-targeting drug.

89Zr-Labeled Multifunctional Liposomes Conjugate Chitosan for PET-Trackable Triple-Negative Breast Cancer Stem Cell Targeted Therapy

Purpose

Therapy for triple-negative breast cancer (TNBC) is a global problem due to lack of specific targets for treatment selection. Cancer stem cells (CSCs) are responsible for tumor formation and recurrence but also offer a promising target for TNBC-targeted therapy. Here, zirconium-89 (⁸⁹Zr)-labelled multifunctional liposomes (MLPs) surface-decorated with chitosan (CS) were fabricated to specifically target and trace cluster of differentiation 44⁺ (CD44⁺) TNBC CSCs specifically.

Patients and Methods

The biological basis of CS targeting CD44 for cancer therapy was investigated by detecting the expression of CD44 in TNBC CSCs and TNBC tissues. Molecular docking and dynamics simulations were performed to investigate the molecular basis of CS targeting CD44 for cancer therapy. Gambogic acid (GA)-loaded, ⁸⁹Zr@CS-MLPs (⁸⁹Zr-CS-GA-MLPs) were prepared, and their uptake and biodistribution were observed. The anti-tumor efficacy of ⁸⁹Zr@CS-GA-MLPs was investigated in vivo.

Results

CD44 is overexpressed in TNBC CSCs and tissues. Molecular docking and dynamics simulations showed that CS could be stably docked into the active site of CD44 in a reasonable conformation. Furthermore, ⁸⁹Zr@CS-GA-MLPs were able to bind specifically to CD44⁺ TNBC stem-like cells and accumulated in tumors of xenograft-bearing mice with excellent radiochemical stability. ⁸⁹Zr@CS-GA-MLPs loaded with GA showed remarkable anti-tumor efficacy in vivo.

Conclusion

The GA-loaded, ⁸⁹Zr-labelled, CS-decorated MLPs developed in this study represent a novel strategy for TNBC imaging and therapy.

Anesthetic propofol epigenetically regulates breast cancer trastuzumab resistance through IL-6/miR-149-5p axis

Propofol, a common intravenous anesthetic, has been found to exert anti-cancer effects with inhibition of cancer cell proliferation, migration and invasion. We tested its possible action against HER2-overexpressing breast cancer cells that developed resistance against trastuzumab. Cell viability assay, ELISA for cytokines, mammosphere formation, quantitative RT-PCR for EMT/IL-6-targeting miRNAs and the in vivo experimental pulmonary metastasis model were performed to understand the epigenetic action of propofol. Propofol sensitized HER2 overexpressing cells to trastuzumab but such action was even more pronounced in resistant cells. Increased cytokines IL-6 as well as IL-8 were released by resistant cells, along with increased mammospheres and induction of EMT, all of which was inhibited by propofol. IL-6 targeting tumor suppressor miR-149-5p was found to be the novel miRNA that was up-regulated by propofol, resulting in the observed effects on cell viability, IL-6 production, mammospheres generation as well as EMT induction. Further, antagonizing miR-149-5p attenuated the propofol effects confirming the epigenetic activity of propofol through miR-149-5p regulation. Finally, in vivo validation in an experimental metastasis model conformed an inhibitory action of propofol against experimental lung metastasis and the essential mechanistic role of miR-149-5p/IL-6 loop. These results present a novel role of general anesthetic propofol against resistant breast cancer cells and the underlying epigenetic regulation of a tumor suppressor miRNA.

Pranlukast Antagonizes CD49f and Reduces Stemness in Triple-Negative Breast Cancer Cells

Introduction

Cancer stem cells (CSCs) drive the initiation, maintenance, and therapy response of breast tumors. CD49f is expressed in breast CSCs and functions in the maintenance of stemness. Thus, blockade of CD49f is a potential therapeutic approach for targeting breast CSCs. In the present study, we aimed to repurpose drugs as CD49f antagonists.

Materials and Methods

We performed consensus molecular docking using a subdomain of CD49f that is critical for heterodimerization and a collection of pharmochemicals clinically tested. Molecular dynamics simulations were employed to further characterize drug-target binding. Using MDA-MB-231 cells, we evaluated the effects of potential CD49f antagonists on 1) cell adhesion to laminin; 2) mammosphere formation; and 3) cell viability. We analyzed the effects of the drug with better CSC-selectivity on the activation of CD49f-downstream signaling by Western blot (WB) and co-immunoprecipitation. Expressions of the stem cell markers CD44 and SOX2 were analyzed by flow cytometry and WB, respectively. Transactivation of SOX2 promoter was evaluated by luciferase reporter assays. Changes in the number of CSCs were assessed by limiting-dilution xenotransplantation.

Results

Pranlukast, a drug used to treat asthma, bound to CD49f in silico and inhibited the adhesion of CD49f⁺ MDA-MB-231 cells to laminin, indicating that it antagonizes CD49f-containing integrins. Molecular dynamics analysis showed that pranlukast binding induces conformational changes in CD49f that affect its interaction with β1-integrin subunit and constrained the conformational dynamics of the heterodimer. Pranlukast decreased the clonogenicity of breast cancer cells on mammosphere formation assay but had no impact on the viability of bulk tumor cells. Brief exposure of MDA-MB-231 cells to pranlukast altered CD49f-dependent signaling, reducing focal adhesion kinase (FAK) and phosphatidylinositol 3-kinase (PI3K) activation. Further, pranlukast-treated cells showed decreased CD44 and SOX2 expression, SOX2 promoter transactivation, and in vivo tumorigenicity, supporting that this drug reduces the frequency of CSC.

Conclusion

Our results support the function of pranlukast as a CD49f antagonist that reduces the CSC population in triple-negative breast cancer cells. The pharmacokinetics and toxicology of this drug have already been established, rendering a potential adjuvant therapy for breast cancer patients.

miR-216a Acts as a Negative Regulator of Breast Cancer by Modulating Stemness Properties and Tumor Microenvironment

Breast cancer is the most frequent malignancy in females in terms of both incidence and mortality. Underlying the high mortality rate is the presence of cancer stem cells, which divide indefinitely and are resistant to conventional chemotherapies, so causing tumor relapse. In the present study, we identify miR-216a-5p as a downregulated microRNA in breast cancer stem cells vs. the differentiated counterpart. We demonstrate that overexpression of miR-216a-5p impairs stemness markers, mammosphere formation, ALDH activity, and the level of Toll-like receptor 4 (TLR4), which plays a significant role in breast cancer progression and metastasis by leading to the release of pro-inflammatory molecules, such as interleukin 6 (IL-6). Indeed, miR-216a regulates the crosstalk between cancer cells and the cells of the microenvironment, in particular cancer-associated fibroblasts (CAFs), through regulation of the TLR4/IL6 pathway. Thus, miR-216a has an important role in the regulation of stem phenotype, decreasing stem-like properties and affecting the cross-talk between cancer cells and the tumor microenvironment.