Sulforaphane Inhibits the Acquisition of Tobacco Smoke-Induced Lung Cancer Stem Cell-Like Properties via the IL-6/ΔNp63α/Notch Axis

7‑Difluoromethoxyl‑5,4'‑di‑n‑octylygenistein targets the STAT3 pathway by upregulating microRNA‑152‑3p expression to inhibit self‑renewal and tumor growth in non‑small cell lung carcinoma

MicroRNAs (miRs) serve a pivotal role in the regulation of non‑small cell lung carcinoma (NSCLC). The present study aimed to investigate the antitumor effects of 7‑difluoromethoxyl‑5,4'‑di‑n‑octylygenistein (DFOG), a novel synthetic genistein derivative, on NSCLC, and to elucidate its molecular mechanism. The research focused on whether DFOG inhibited self‑renewal and tumor growth in NSCLC by modulating the miR‑152‑3p/STAT3 signaling pathway. Reverse transcription‑quantitative PCR and western blot analyses were employed to assess miR‑152‑3p expression and phosphorylated‑STAT3 (p‑STAT3) levels. The effects of DFOG on self‑renewal and tumor growth were evaluated via sphere formation and clonogenic assays. Additionally, sphere‑forming cells (SFCs) were enriched using a suspension culture method, and western blot analysis was conducted to examine stemness markers (CD133, CD44, Oct4 and Sox2). The results demonstrated that DFOG inhibited self‑renewal and tumor growth in NSCLC. This effect was associated with increased miR‑152‑3p expression, decreased STAT3 mRNA levels and reduced p‑STAT3 levels in NSCLC cells. Furthermore, inhibition or overexpression of STAT3 did not alter miR‑152‑3p expression but modulated the inhibitory effects of DFOG on self‑renewal and tumor growth. These findings highlighted that DFOG suppressed self‑renewal and tumor growth in SFCs derived from NSCLC by directly targeting STAT3 through the upregulation of miR‑152‑3p.

EGCG inhibits tobacco smoke-promoted proliferation of lung cancer cells through targeting CCL5

BACKGROUND

The occurrence and development of cancer are deeply intertwined with chronic inflammatory processes. Epigallocatechin gallate (EGCG), the most pharmacologically potent catechin derived from tea, has garnered attention for its anti-inflammatory and anti-carcinogenic properties. However, the molecular mechanisms through which EGCG modulates tobacco smoke (TS)-induced inflammatory responses in lung carcinogenesis remain incompletely elucidated.

PURPOSE

To unravel the molecular mechanisms by which EGCG mitigates TS-induced inflammatory processes in lung carcinogenesis.

METHODS

Network pharmacology analysis was conducted to explore the potential target genes of EGCG involved in the inhibition of TS-induced lung cancer inflammation. In vitro and in vivo experiments were conducted to demonstrate EGCG's chemopreventive potential against lung carcinogenesis.

RESULTS

Utilizing data from the US adults, it was uncovered that tea consumption could suppress the inflammatory response in patients with various cancer types. CCL5 (chemokine (CC motif) ligand 5) could function as a core regulator of TS-induced lung cancer cell proliferation, and EGCG exerted beneficial effects. The following experiments revealed that TS upregulated CCL5 expression in H1299 and H226 cells. CCL5 recombinant protein elevated both ROS production and Nrf2 expression to promote lung cancer cell proliferation. EGCG could suppress CCL5-stimulated lung cancer cell proliferation by downregulating Nrf2 expression. In the mouse model, EGCG reduced tumor weight and volume, diminished the levels of CCL5, Ki67, Cyclin D1, PCNA, and Nrf2, and elevated the expression of Keap1 relative to the control group.

CONCLUSION

EGCG targets CCL5 to inhibit the proliferation of TS-induced lung cancer cells and may serve as a new treatment strategy.

Effects of sulforaphane on prostate cancer stem cells-like properties: In vitro and molecular docking studies

The increasing incidence of prostate cancer worldwide has spurred research into novel therapeutics for its treatment and prevention. A critical factor contributing to its incidence and development is the presence of prostate cancer stem cells (PCSCs). Targeting PCSCs has become key in enhancing therapeutic and clinical outcomes of prostate cancer. Sulforaphane (SFN), a compound found in cruciferous vegetables, has shown effective antineoplastic activity in prostate cancer. Yet, its mechanisms of action in PCSCs remains unclear. In the present study, tumorsphere formation assay was used to isolate and enrich PCSCs from PC-3 cells. Our results found that SFN effectively reduced the activity of PCSCs, including the ability of tumorsphere formation, the number of CD133 positive cells, and the expression of PCSCs markers. Moreover, the data showed that SFN inhibited PCSCs through downregulating the activation of Wnt/β-catenin and hedgehog signaling pathways in PCSCs. Furthermore, the verification experiments showed that the activators of Wnt/β-catenin (LiCl) and hedgehog (purmorphamine) attenuated the effects of SFN on PCSCs, including the expression of stem cell markers, cell proliferation and apoptosis. Meanwhile, suppression of β-catenin or Smoothened enhanced the effects of SFN on PCSCs. In addition, molecular docking further indicated that SFN inhibited Wnt/β-catenin and hedgehog pathways by directly targeting β-catenin and Smoothened. Taken together, our results demonstrated that SFN targeted PCSCs through Wnt/β-catenin and hedgehog pathways to inhibit stemness and proliferation and induce apoptosis. Findings from this study could provide new insights into SFN as a dietary supplement or adjunct to chemotherapy.

Sulforaphane reverses the enhanced NSCLC metastasis by regulating the miR-7-5p/c-Myc/LDHA axis in the acidic tumor microenvironment

BACKGROUND

The presence of distant metastasis at the time of initial diagnosis is a prevalent issue in non-small cell lung cancer (NSCLC), affecting around 30-40 % of the patients. Acidic tumor microenvironment (TME) provides favorable conditions that increase the invasiveness and aggressiveness of NSCLC. The activity of the glycolytic enzyme lactate dehydrogenase (LDHA) increases intracellular lactate accumulation, which creates an acidic TME. However, it is not yet known whether LDHA is involved in enhancing the metastatic potential of NSCLC and if LDHA is a druggable therapeutic target for NSCLC.

PURPOSE

We aimed to investigate the molecular mechanisms underlying the enhanced NSCLC metastasis in acidic TME, and to explore whether sulforaphane (SFN), an active compound in Raphani Semen, can serve as a LDHA inhibitor to inhibit NSCLC metastasis in the acidic TME.

METHODS

To mimic the acidic TME, NSCLC cells were cultured in acidic medium (pH 6.6), normal medium (pH 7.4) served as control. Western blotting, bioinformatic analysis, luciferase assay and rescue experiments were used to explore the mechanism and investigate the anti-metastatic effect of SFN both in vitro and in vivo.

RESULTS

Acidic environment increases the expression of LDHA which in turn increases the production of lactic acid that contributes to the acidity of TME. Interestingly, elevated LDHA expression results from increased c-Myc expression, which transactivates LDHA. c-Myc expression is directly regulated by miR-7-5p. In vitro study shows that overexpression of miR-7-5p reverses the acidic pH-enhanced c-Myc and LDHA expressions and also abolishes the enhanced NSCLC cell migration. More importantly, SFN significantly inhibits NSCLC growth and metastasis by reducing lactate production via the miR-7-5p/c-Myc/LDHA axis. Besides, it also regulates the expressions of monocarboxylate transporter 1 (MCT1) and MCT4 that transport lactate across cell membrane.

CONCLUSIONS

The miR-7-5p/c-Myc/LDHA axis is involved in the enhanced NSCLC metastasis in the acidic TME. SFN, a novel LDHA inhibitor, reduces lactate production by targeting the miR-7-5p/c-Myc/LDHA axis, and hence inhibits NSCLC metastasis. Our findings not only delineate a novel mechanism, but also support the clinical translation of SFN as a novel therapeutic agent for treating metastatic NSCLC.

Acute exposure to electronic cigarette components alters mRNA expression of pre-osteoblasts

The use of traditional nicotine delivery products such as tobacco has long been linked to detrimental health effects. However, little work to date has focused on the emerging market of aerosolized nicotine delivery known as electronic nicotine delivery systems (ENDS) or electronic cigarettes, and their potential for new effects on human health. Challenges studying these devices include heterogeneity in the formulation of the common components of most available ENDS, including nicotine and a carrier (commonly composed of propylene glycol and vegetable glycerin, or PG/VG). In the present study, we report on experiments interrogating the effects of major identified components in e-cigarettes. Specifically, the potential concomitant effects of nicotine and common carrier ingredients in commercial "vape" products are explored in vitro to inform the potential health effects on the craniofacial skeleton through novel vectors as compared to traditional tobacco products. MC3T3-E1 murine pre-osteoblast cells were cultured in vitro with clinically relevant liquid concentrations of nicotine, propylene glycol (PG), vegetable glycerin (VG), Nicotine+PG/VG, and the vape liquid of a commercial product (Juul). Cells were treated acutely for 24 h and RNA-Seq was utilized to determine segregating alteration in mRNA signaling. Influential gene targets identified with sparse partial least squares discriminant analysis (sPLS-DA) implemented in mixOmics were assessed using the PANTHER Classification system for molecular functions, biological processes, cellular components, and pathways of effect. Additional endpoint functional analyses were used to confirm cell cycle changes. The initial excitatory concentration (EC50) studied defined a target concentration of carrier PG/VG liquid that altered the cell cycle of the calvarial cells. Initial sPLS-DA analysis demonstrated the segregation of nicotine and non-nicotine exposures utilized in our in vitro modeling. Pathway analysis suggests a strong influence of nicotine exposures on cellular processes including metabolic processes and response to stimuli including autophagic flux. Further interrogation of the individual treatment conditions demonstrated segregation by treatment modality (Control, Nicotine, Carrier (PG+VG), Nicotine+PG/VG) along three dimensions best characterized by: latent variable 1 (PLSDA-1) showing strong segregation based on nicotine influence on cellular processes associated with cellular adhesion to collagen, osteoblast differentiation, and calcium binding and metabolism; latent variable 2 (PLSDA-2) showing strong segregation of influence based on PG+VG and Control influence on cell migration, survival, and cycle regulation; and latent variable 3 (PLSDA-3) showing strong segregation based on Nicotine and Control exposure influence on cell activity and growth and developmental processes. Further, gene co-expression network analysis implicates targets of the major pathway genes associated with bone growth and development, particularly craniofacial (FGF, Notch, TGFβ, WNT) and analysis of active subnetwork pathways found these additionally overrepresented in the Juul exposure relative to Nicotine+PG/VG. Finally, experimentation confirmed alterations in cell count, and increased evidence of cell stress (markers of autophagy), but no alteration in apoptosis. These data suggest concomitant treatment with Nicotine+PG/VG drives alterations in pre-osteoblast cell cycle signaling, specifically transcriptomic targets related to cell cycle and potentially cell stress. Although we suspected cell stress and well as cytotoxic effects of Nicotine+PG/VG, no great influence on apoptotic factors was observed. Further RNA-Seq analysis allowed for the direct interrogation of molecular targets of major pathways involved in bone and craniofacial development, each demonstrating segregation (altered signaling) due to e-cigarette-type exposure. These data have implications directed toward ENDS formulation as synergistic effects of Nicotine+PG/VG are evidenced here. Thus, future research will continue to interrogate how varied formulation of Nicotine+PG/VG affects overall cell functions in multiple vital systems.

Correlation of CD 133 Biomarker with Outcomes and Therapy Response in Advanced-Stage Non-Small Cell Lung Carcinoma

OBJECTIVE

This study aimed to analyze CD 133 stem cell biomarker levels in serum and bronchial lavage, as well as correlate these levels with treatment responses and outcomes in patients with advanced-stage NSCLC.

METHODS

This is a cross-sectional, observational, and analytical study that analyzed data from NSCLC patients and control at Dr. Wahidin Sudirohusodo Hospital, Makassar. CD 133 levels in serum and bronchial lavages were quantified using ELISA and correlated with treatment responses assessed by RECIST 1.1 criteria.

RESULT

A total of 118 participants were used, with 66 being NSCLC patients and 52 as the control. The results showed significant differences in CD 133 serum and bronchial lavage levels (p<0.05). Moreover, NSCLC patients with advanced tumors (T4) had higher CD 133 levels in bronchial wash (p<0.05). The bronchial wash CD 133 test showed higher sensitivity (83.6%) and specificity (79.2%) compared to serum CD 133. Even though CD 133 levels were not significantly correlated with treatment response, they were higher in patients with advanced tumor stages.

CONCLUSION

CD 133 levels were significantly higher in bronchial wash samples from NSCLC patients with advanced tumors (T4). Also, there was a positive correlation between CD 133 levels in bronchial wash and serum. These results emphasized the potential of CD 133, particularly in bronchial wash, as a valuable diagnostic tool for NSCLC.

ΔNp63α promotes cigarette smoke-induced renal cancer stem cell activity via the Sonic Hedgehog pathway

Cigarette smoke (CS) has been generally recognized as a chief carcinogenic factor in renal cell carcinoma (RCC). The stimulative effect of CS on renal cancer stem cells (RCSCs) has been described previously. The Sonic Hedgehog (SHH) pathway plays an essential role in self-renewal, cell growth, drug resistance, metastasis, and recurrence of cancer stem cells (CSCs). Renal cancer-related gene ΔNp63α is highly expressed in renal epithelial tissues and contributes to the RCSCs characteristics of tumors. The aim of this study was to elucidate the role of ΔNp63α and the SHH pathway on the activity of RCSCs induced by CS through a series of in vivo and in vitro studies. It was shown that in renal cancer tissues, ΔNp63α and RCSCs markers in smokers are expressed higher than that in non-smokers. RCSCs were effectively enriched by tumor sphere formation assay. Besides, CS increased the expression of RCSCs markers and the capability of sphere-forming in vitro and in vivo. Moreover, the SHH pathway was activated, and the specialized inhibitor alleviated the promotion of CS on RCSCs. ΔNp63α activated the SHH pathway and promoted CS-induced enhancement of RCSCs activity. These findings indicate that ΔNp63α positively regulates the activity of CS-induced RCSCs via the SHH pathway.

Competitive-like binding between carbon black and CTNNB1 to ΔNp63 interpreting the abnormal respiratory epithelial repair after injury

Airway epithelium is extraordinary vulnerable to damage owning to continuous environment exposure. Subsequent repair is therefore essential to restore the homeostasis of respiratory system. Disruptions in respiratory epithelial repair caused by nanoparticles exposure have been linked to various human diseases, yet implications in repair process remain incompletely elucidated. This study aims to elucidate the key stage in epithelial repair disturbed by carbon black (CB) nanoparticles, highlighting the pivotal role of ΔNp63 in mediating the epithelium repair. A competitive-like binding between CB and beta-catenin 1 (CTNNB1) to ΔNp63 is proposed to elaborate the underlying toxicity mechanism. Specifically, CB exhibits a remarkable inhibitory effect on cell proliferation, leading to aberrant airway epithelial repair, as validated in air-liquid culture. ΔNp63 drives efficient epithelial proliferation during CB exposure, and CTNNB1 was identified as a target of ΔNp63 by bioinformatics analysis. Further molecular dynamics simulation reveals that oxygen-containing functional groups on CB disrupt the native interaction of CTNNB1 with ΔNp63 through competitive-like binding pattern. This process modulates CTNNB1 expression, ultimately restraining proliferation during respiratory epithelial repair. Overall, the current study elucidates that the diminished interaction between CTNNB1 and ΔNp63 impedes respiratory epithelial repair in response to CB exposure, thereby enriching the public health risk assessment on CB-related respiratory diseases.

Dietary isothiocyanates and anticancer agents: exploring synergism for improved cancer management

Human studies have shown the anticancer effects of dietary isothiocyanates (ITCs), but there are some inconsistencies, and more evidence supports that such anticancer effect is from higher doses of ITCs. The inconsistencies found in epidemiological studies may be due to many factors, including the biphasic dose-response (so called hormetic effect) of ITCs, which was found to be more profound under hypoxia conditions. In this comprehensive review, we aim to shed light on the intriguing synergistic interactions between dietary ITCs, focusing on sulforaphane (SFN) and various anticancer drugs. Our exploration is motivated by the potential of these combinations to enhance cancer management strategies. While the anticancer properties of ITCs have been recognized, our review delves deeper into understanding the mechanisms and emphasizing the significance of the hormetic effect of ITCs, characterized by lower doses stimulating both normal cells and cancer cells, whereas higher doses are toxic to cancer cells and inhibit their growth. We have examined a spectrum of studies unraveling the multifaceted interaction and combinational effects of ITCs with anticancer agents. Our analysis reveals the potential of these synergies to augment therapeutic efficacy, mitigate chemoresistance, and minimize toxic effects, thereby opening avenues for therapeutic innovation. The review will provide insights into the underlying mechanisms of action, for example, by spotlighting the pivotal role of Nrf2 and antioxidant enzymes in prevention. Finally, we glimpse ongoing research endeavors and contemplate future directions in this dynamic field. We believe that our work contributes valuable perspectives on nutrition and cancer and holds promise for developing novel and optimized therapeutic strategies.

Notch signaling pathway in cancer: from mechanistic insights to targeted therapies

Notch signaling, renowned for its role in regulating cell fate, organ development, and tissue homeostasis across metazoans, is highly conserved throughout evolution. The Notch receptor and its ligands are transmembrane proteins containing epidermal growth factor-like repeat sequences, typically necessitating receptor-ligand interaction to initiate classical Notch signaling transduction. Accumulating evidence indicates that the Notch signaling pathway serves as both an oncogenic factor and a tumor suppressor in various cancer types. Dysregulation of this pathway promotes epithelial-mesenchymal transition and angiogenesis in malignancies, closely linked to cancer proliferation, invasion, and metastasis. Furthermore, the Notch signaling pathway contributes to maintaining stem-like properties in cancer cells, thereby enhancing cancer invasiveness. The regulatory role of the Notch signaling pathway in cancer metabolic reprogramming and the tumor microenvironment suggests its pivotal involvement in balancing oncogenic and tumor suppressive effects. Moreover, the Notch signaling pathway is implicated in conferring chemoresistance to tumor cells. Therefore, a comprehensive understanding of these biological processes is crucial for developing innovative therapeutic strategies targeting Notch signaling. This review focuses on the research progress of the Notch signaling pathway in cancers, providing in-depth insights into the potential mechanisms of Notch signaling regulation in the occurrence and progression of cancer. Additionally, the review summarizes pharmaceutical clinical trials targeting Notch signaling for cancer therapy, aiming to offer new insights into therapeutic strategies for human malignancies.

Tumor microenvironment of cancer stem cells: Perspectives on cancer stem cell targeting

There are few tumor cell subpopulations with stem cell characteristics in tumor tissue, defined as cancer stem cells (CSCs) or cancer stem-like cells (CSLCs), which can reconstruct neoplasms with malignant biological behaviors such as invasiveness via self-renewal and unlimited generation. The microenvironment that CSCs depend on consists of various cellular components and corresponding medium components. Among these factors existing at a variety of levels and forms, cytokine networks and numerous signal pathways play an important role in signaling transduction. These factors promote or maintain cancer cell stemness, and participate in cancer recurrence, metastasis, and resistance. This review aims to summarize the recent molecular data concerning the multilayered relationship between CSCs and CSC-favorable microenvironments. We also discuss the therapeutic implications of targeting this synergistic interplay, hoping to give an insight into targeting cancer cell stemness for tumor therapy and prognosis.

Regulation of the Notch signaling pathway by natural products for cancer therapy

The Notch signaling pathway is an evolutionarily conserved pathway that modulates normal biological processes involved in cellular differentiation, apoptosis, and stem cell self-renewal in a context-dependent fashion. Attributed to its pleiotropic physiological roles, both overexpression and silencing of the pathway are associated with the emergence, progression, and poorer prognosis in various types of cancer. To decrease disease incidence and promote survival, targeting Notch may have chemopreventive and anti-cancer effects. Natural products with profound historical origins have distinguished themselves from other therapies due to their easy access, high biological compatibility, low toxicity, and reliable effects at specific physiological sites in vivo. This review describes the Notch signaling pathway, particularly its normal activation process, and some main illnesses related to Notch signaling pathway dysregulation. Emphasis is placed on the effects and mechanisms of natural products targeting the Notch signaling pathway in diverse cancer types, including curcumin, ellagic acid (EA), resveratrol, genistein, epigallocatechin-3-gallate (EGCG), quercetin, and xanthohumol and so on. Existing evidence indicates that natural products are feasible solution to fight against cancer by targeting Notch signaling, either alone or in combination with current therapeutic agents.

Dysregulation of delta Np63 alpha in squamous cell carcinoma and its therapeutic targeting

The gene p63 has two isoforms -a full length transactivated isoform (TA) p63 and an amino-terminally truncated isoform, ∆Np63. DeltaNp63 alpha (∆Np63α) is the predominant splice variant of the isoform, ∆Np63 and is expressed in the basal layer of stratified epithelia. ∆Np63α that is normally essential for the epithelial lineage maintenance may be dysregulated in squamous cell carcinomas (SCCs). The pro-tumorigenic or antitumorigenic role of ∆Np63 is a highly contentious arena. ∆Np63α may act as a double-edged sword. It may either promote tumor progression, epithelial-mesenchymal transition, migration, chemoresistance, and immune-inflammatory responses, or inhibit the aforementioned phenomena depending upon cell type and tumor microenvironment. Several signaling pathways, transforming growth factor-β, Wnt and Notch, as well as epigenetic alterations involving microRNAs, and long noncoding RNAs are regulated by ∆Np63α. This review has attempted to provide an in-depth insight into the role of ∆Np63α in the development of SCCs during different stages of tumor formation and how it may be targeted for therapeutic implications.

Role of natural products in tumor therapy from basic research and clinical perspectives

Cancer is the leading cause of morbidity and mortality worldwide and is an important barrier to lengthening life expectancy in every country. Natural products are receiving increased attention from researchers globally and increasing numbers of natural products are approved for clinical studies involving cancer in recent years. To gain more insight into natural products that have undergone clinical trials for cancer treatment, a comprehensive search was conducted. The https://clinicaltrials.gov website was searched for relevant clinical trials and natural product information up to December 2022. The search terms included different types of cancers, such as colorectal, lung, breast, gynecologic, kidney, bladder, melanoma, pancreatic, hepatocellular, gastric and haematologic. Then, PubMed and Web of Science were searched for relevant articles up to February 2024. Hence, we listed existing clinical trials about natural products used in the treatment of cancers and discussed the preclinical and clinical studies of some promising natural products and their targets, indications, and underlying mechanisms of action. Our intent was to provide basic information to readers who are interested or majoring in natural products and obtain a deeper understanding of the progress and actions of natural product mechanisms of action.

NFAT signaling dysregulation in cancer: Emerging roles in cancer stem cells

The nuclear factor of activated T cells (NFAT) was first identified as a transcriptional regulator of activated T cells. The NFAT family is involved in the development of tumors. Furthermore, recent evidence reveals that NFAT proteins regulate the development of inflammatory and immune responses. New discoveries have also been made about the mechanisms by which NFAT regulates cancer progression through cancer stem cells (CSC). Here, we discuss the role of the NFAT family in the immune system and various cancer types.

Heterocyclic Molecular Targeted Drugs and Nanomedicines for Cancer: Recent Advances and Challenges

Cancer is a top global public health concern. At present, molecular targeted therapy has emerged as one of the main therapies for cancer, with high efficacy and safety. The medical world continues to struggle with the development of efficient, extremely selective, and low-toxicity anticancer medications. Heterocyclic scaffolds based on the molecular structure of tumor therapeutic targets are widely used in anticancer drug design. In addition, a revolution in medicine has been brought on by the quick advancement of nanotechnology. Many nanomedicines have taken targeted cancer therapy to a new level. In this review, we highlight heterocyclic molecular-targeted drugs as well as heterocyclic-associated nanomedicines in cancer.

Conducting bioinformatics analysis to predict sulforaphane-triggered adverse outcome pathways in healthy human cells

Sulforaphane (SFN) is a naturally occurring molecule present in plants from Brassica family. It becomes bioactive after hydrolytic reaction mediated by myrosinase or human gastrointestinal microbiota. Sulforaphane gained scientific popularity due to its antioxidant and anti-cancer properties. However, its toxicity profile and potential to cause adverse effects remain largely unidentified. Thus, this study aimed to generate SFN-triggered adverse outcome pathway (AOP) by looking at the relationship between SFN-chemical structure and its toxicity, as well as SFN-gene interactions. Quantitative structure-activity relationship (QSAR) analysis identified 2 toxophores (Derek Nexus software) that have the potential to cause chromosomal damage and skin sensitization in mammals or mutagenicity in bacteria. Data extracted from Comparative Toxicogenomics Database (CTD) linked SFN with previously proposed outcomes via gene interactions. The total of 11 and 146 genes connected SFN with chromosomal damage and skin diseases, respectively. However, network analysis (NetworkAnalyst tool) revealed that these genes function in wider networks containing 490 and 1986 nodes, respectively. The over-representation analysis (ExpressAnalyst tool) pointed out crucial biological pathways regulated by SFN-interfering genes. These pathways are uploaded to AOP-helpFinder tool which found the 2321 connections between 19 enriched pathways and SFN which were further considered as key events. Two major, interconnected AOPs were generated: first starting from disruption of biological pathways involved in cell cycle and cell proliferation leading to increased apoptosis, and the second one connecting activated immune system signaling pathways to inflammation and apoptosis. In both cases, chromosomal damage and/or skin diseases such as dermatitis or psoriasis appear as adverse outcomes.

ΔNp63α in cancer: importance and therapeutic opportunities

Our understanding of cancer and the key pathways that drive cancer survival has expanded rapidly over the past several decades. However, there are still important challenges that continue to impair patient survival, including our inability to target cancer stem cells (CSCs), metastasis, and drug resistance. The transcription factor p63 is a p53 family member with multiple isoforms that carry out a wide array of functions. Here, we discuss the critical importance of the ΔNp63α isoform in cancer and potential therapeutic strategies to target ΔNp63α expression to impair the CSC population, as well as to prevent metastasis and drug resistance to improve patient survival.

Low-dose phthalates promote breast cancer stem cell properties via the oncogene ΔNp63α and the Sonic hedgehog pathway

BACKGROUND

The omnipresence of human phthalate (PAE) exposure is linked to various adverse health issues, including breast cancer. However, the effects of low-dose PAE exposure on breast cancer stem cells (BCSCs) and the underlying mechanism remain unexplored.

METHODS

BCSCs from breast cancer cell lines (MDA-MB-231 and MCF-7) were enriched using a tumorsphere formation assay. Gene and protein expression was detected by measurement of quantitative real-time reverse transcription PCR, western blot, and immunofluorescence assays. Transient transfection assays were used to evaluate the involvement of Gli1, a signaling pathway molecule and ΔNp63α, an oncogene in influencing the PAE-induced characteristics of BCSCs.

RESULTS

PAE (butylbenzyl phthalate, BBP; di-butyl phthalate, DBP; di-2-ethylhexyl phthalate, DEHP) exposure of 10^-9 M significantly promoted the tumorsphere formation ability in BCSCs. Breast cancer spheroids with a 10^-9 M PAE exposure had higher levels of BCSC marker mRNA and protein expression, activated sonic hedgehog (SHH) pathway, and increased mRNA and protein levels of an oncogene, ΔNp63α. Furthermore, suppression of the SHH pathway attenuated the effects of PAEs on BCSCs. And the overexpression of ΔNp63α enhanced PAE-induced characteristics of BCSCs, while low expression of ΔNp63α inhibited the promotion effects of PAEs on BCSCs and the SHH pathway.

CONCLUSION

Low-dose PAE exposure promoted the stem cell properties of BCSCs in a ΔNp63α- and SHH-dependent manner. The influence of low-dose exposure of PAEs and its relevance for the lowest observed effect concentrations requires further investigation, and the precise underlying mechanism needs to be further explored.

Isothiocyanates attenuate immune checkpoint blockage therapy in gastric cancer via induction of PD-L1 expression

The PD-1/PD-L1 immune checkpoint blockade therapy has shown revolutionary efficacy in the treatment of multiple cancers including gastric cancer. Isothiocyanates play important roles in cancer cell suppression and immunomodulation. However, the effects of isothiocyanates on immune checkpoint inhibitors are poorly understood in gastric cancer. The influence of three major isothiocyanates (sulforaphane, phenylethyl isothiocyanate, and benzhydryl isothiocyanate) on gastric cancer cell growth and PD-L1 expression was investigated. Syngeneic mouse models were administered by isothiocyanates and anti-PD-L1 monoclonal antibody, and the anti-tumor effects were assessed. The expression of PD-L1, proportion of lymphocytes and serum cytokine levels were detected to explore the underlying mechanisms. We found that PD-L1 expression was significantly induced by isothiocyanates which was associated with TAp63α up-regulation. We further revealed that TAp63α promoted PD-L1 through transcriptional activation. Combination treatment of isothiocyanates and anti-PD-L1 therapy weakened the sensitivity of gastric cancer cells to anti-PD-L1 drug. Moreover, in vivo studies illustrated that the interference effects of isothiocyanates on anti-PD-L1 antibody were related to PD-L1 expression and decreased infiltrating T lymphocytes in tumor bearing mouse hosts. Our findings provide novel insights as isothiocyanates could interfere with the successful application of immunotherapy in gastric cancer.

PI3K/AKT/mTOR pathway mediated-cell cycle dysregulation contribute to malignant proliferation of mouse spermatogonia induced by microcystin-leucine arginine

Environmental cyanotoxin exposure may be a trigger of testicular cancer. Activation of PI3K/AKT/mTOR signaling pathway is the critical molecular event in testicular carcinogenesis. As a widespread cyanotoxin, microcystin-leucine arginine (MC-LR) is known to induce cell malignant transformation and tumorigenesis. However, the effects of MC-LR on the regulatory mechanism of PI3K/AKT/mTOR pathway in seminoma, the most common testicular tumor, are unknown. In this study, mouse spermatogonia cell line (GC-1) and nude mice were used to investigate the effects and mechanisms of MC-LR on the malignant transformation of spermatogonia by nude mouse tumorigenesis assay, cell migration invasion assay, western blot, and cell cycle assay, and so forth. The results showed that, after continuous exposure to environmentally relevant concentrations of MC-LR (20 nM) for 35 generations, the proliferation, migration, and invasion abilities of GC-1 cells were increased by 120%, 340%, and 370%, respectively. In nude mice, MC-LR-treated GC-1 cells formed tumors with significantly greater volume (0.998 ± 0.768 cm³ ) and weight (0.637 ± 0.406 g) than the control group (0.067 ± 0.039 cm³ ; 0.094 ± 0.087 g) (P < .05). Furthermore, PI3K inhibitor Wortmannin inhibited the PI3K/AKT/mTOR pathway and its downstream proteins (c-MYC, CDK4, CCND1, and MMP14) activated by MC-LR. Blocking PI3K alleviated MC-LR-induced cell cycle disorder and malignant proliferation, migration and invasive of GC-1 cells. Altogether, our findings suggest that MC-LR can induce malignant transformation of mouse spermatogonia, and the PI3K/AKT/mTOR pathway-mediated cell cycle dysregulation may be an important target for malignant proliferation. This study provides clues to further reveal the etiology and pathogenesis of seminoma.

The dual role of p63 in cancer

The p53 family is made up of three transcription factors: p53, p63, and p73. These proteins are well-known regulators of cell function and play a crucial role in controlling various processes related to cancer progression, including cell division, proliferation, genomic stability, cell cycle arrest, senescence, and apoptosis. In response to extra- or intracellular stress or oncogenic stimulation, all members of the p53 family are mutated in structure or altered in expression levels to affect the signaling network, coordinating many other pivotal cellular processes. P63 exists as two main isoforms (TAp63 and ΔNp63) that have been contrastingly discovered; the TA and ΔN isoforms exhibit distinguished properties by promoting or inhibiting cancer progression. As such, p63 isoforms comprise a fully mysterious and challenging regulatory pathway. Recent studies have revealed the intricate role of p63 in regulating the DNA damage response (DDR) and its impact on diverse cellular processes. In this review, we will highlight the significance of how p63 isoforms respond to DNA damage and cancer stem cells, as well as the dual role of TAp63 and ΔNp63 in cancer.

An integrative approach for identification of smoking-related genes involving bladder cancer

Tobacco smoking is one of the most important environmental risk factors involving bladder tumorigenesis. However, smoking-related genes in bladder carcinogenesis and corresponding genetic effects on bladder cancer risk remain unclear. Weighted correlation network analysis (WGCNA) underlying transcriptome of bladder cancer tissues was applied to identify smoking-related genes. The logistic regression model was utilized to estimate genetic effects of single nucleotide polymorphisms (SNPs) in smoking-related genes on bladder cancer risk in the Chinese and European populations with a total of 6510 cases and 6569 controls, as well as the interaction with smoking status. Transcriptome of cells and tissues was used to profile the expression pattern of candidate genes and their genetic variants. Our results demonstrated that a total of 24 SNPs in 14 smoking-related genes were associated with the risk of bladder cancer, of which rs9348451 in CDKAL1 exhibited an interaction with smoking status (OR_interaction = 1.38, P_interaction = 1.08 × 10^-2) and tobacco smoking might combine with CDKAL1 rs9348451 to increase the risk of bladder cancer (P_trend = 4.27 × 10^-4). Moreover, rs9348451 was associated with CDKAL1 expression in bladder cancer, especially in smokers (P < 0.001). Besides, CDKAL1 was upregulated in bladder cancer compared to normal adjacent tissues, as well as upregulated via treatment of cigarette smoke extracts. This study highlights the important role of nurture and nature, as well as their interaction on tumorigenesis, which provides a new way to decipher the etiology of bladder cancer with smoking status.

Interleukin-17A mediates tobacco smoke-induced lung cancer epithelial-mesenchymal transition through transcriptional regulation of ΔNp63α on miR-19

Interleukin-17A (IL-17A) is an essential inflammatory cytokine in the progress of carcinogenesis. Tobacco smoke (TS) is a major risk factor of lung cancer that influences epithelial-mesenchymal transition (EMT) process. However, the potential mechanism by which IL-17A mediates the progression of lung cancer in TS-induced EMT remains elusive. In the present study, it was revealed that the IL-17A level was elevated in lung cancer tissues, especially in tumor tissues of cases with experience of smoking, and a higher IL-17A level was correlated with induction of EMT in those specimens. Moreover, the expression of ΔNp63α was increased in IL-17A-stimulated lung cancer cells. ΔNp63α functioned as a key oncogene that bound to the miR-17-92 cluster promoter and transcriptionally increased the expression of miR-19 in lung cancer cells. Overexpression of miR-19 promoted EMT in lung cancer with downregulation of E-cadherin and upregulation of N-cadherin, while its inhibition suppressed EMT. Finally, the upregulated levels of IL-17A, ΔNp63α, and miR-19 along with the alteration of EMT-associated biomarkers were found in lung tissues of TS-exposed mice. Taken together, the abovementioned results suggest that IL-17A increases ΔNp63α expression, transcriptionally elevates miR-19 expression, and promotes TS-induced EMT in lung cancer. These findings may provide a new insight for the identification of therapeutic targets for lung cancer.

Targeting Cancer Stem Cells by Dietary Agents: An Important Therapeutic Strategy against Human Malignancies

As a multifactorial disease, treatment of cancer depends on understanding unique mechanisms involved in its progression. The cancer stem cells (CSCs) are responsible for tumor stemness and by enhancing colony formation, proliferation as well as metastasis, and these cells can also mediate resistance to therapy. Furthermore, the presence of CSCs leads to cancer recurrence and therefore their complete eradication can have immense therapeutic benefits. The present review focuses on targeting CSCs by natural products in cancer therapy. The growth and colony formation capacities of CSCs have been reported can be attenuated by the dietary agents. These compounds can induce apoptosis in CSCs and reduce tumor migration and invasion via EMT inhibition. A variety of molecular pathways including STAT3, Wnt/β-catenin, Sonic Hedgehog, Gli1 and NF-κB undergo down-regulation by dietary agents in suppressing CSC features. Upon exposure to natural agents, a significant decrease occurs in levels of CSC markers including CD44, CD133, ALDH1, Oct4 and Nanog to impair cancer stemness. Furthermore, CSC suppression by dietary agents can enhance sensitivity of tumors to chemotherapy and radiotherapy. In addition to in vitro studies, as well as experiments on the different preclinical models have shown capacity of natural products in suppressing cancer stemness. Furthermore, use of nanostructures for improving therapeutic impact of dietary agents is recommended to rapidly translate preclinical findings for clinical use.

Sulforaphane: A Broccoli Bioactive Phytocompound with Cancer Preventive Potential

Simple Summary

As of the past decade, phytochemicals have become a major target of interest in cancer chemopreventive and chemotherapeutic research. Sulforaphane (SFN) is a metabolite of the phytochemical glucoraphanin, which is found in high abundance in cruciferous vegetables, such as broccoli, watercress, Brussels sprouts, and cabbage. In both distant and recent research, SFN has been shown to have a multitude of anticancer effects, increasing the need for a comprehensive review of the literature. In this review, we critically evaluate SFN as an anticancer agent and its mechanisms of action based on an impressive number of in vitro, in vivo, and clinical studies.

Abstract

There is substantial and promising evidence on the health benefits of consuming broccoli and other cruciferous vegetables. The most important compound in broccoli, glucoraphanin, is metabolized to SFN by the thioglucosidase enzyme myrosinase. SFN is the major mediator of the health benefits that have been recognized for broccoli consumption. SFN represents a phytochemical of high interest as it may be useful in preventing the occurrence and/or mitigating the progression of cancer. Although several prior publications provide an excellent overview of the effect of SFN in cancer, these reports represent narrative reviews that focused mainly on SFN’s source, biosynthesis, and mechanisms of action in modulating specific pathways involved in cancer without a comprehensive review of SFN’s role or value for prevention of various human malignancies. This review evaluates the most recent state of knowledge concerning SFN’s efficacy in preventing or reversing a variety of neoplasms. In this work, we have analyzed published reports based on in vitro, in vivo, and clinical studies to determine SFN’s potential as a chemopreventive agent. Furthermore, we have discussed the current limitations and challenges associated with SFN research and suggested future research directions before broccoli-derived products, especially SFN, can be used for human cancer prevention and intervention.

Targeting cancer stem cells by nutraceuticals for cancer therapy

Accumulating evidence has demonstrated that cancer stem cells (CSCs) play an essential role in tumor progression and reoccurrence and drug resistance. Multiple signaling pathways have been revealed to be critically participated in CSC development and maintenance. Emerging evidence indicates that numerous chemopreventive compounds, also known as nutraceuticals, could eliminate CSCs in part via regulating several signaling pathways. Therefore, in this review, we will describe the some natural chemopreventive agents that target CSCs in a variety of human malignancies, including soy isoflavone, curcumin, resveratrol, tea polyphenols, sulforaphane, quercetin, indole-3-carbinol, 3,3'-diindolylmethane, withaferin A, apigenin, etc. Moreover, we discuss that eliminating CSCs by nutraceuticals might be a promising strategy for treating human cancer via overcoming drug resistance and reducing tumor reoccurrence.

Understanding Lung Carcinogenesis from a Morphostatic Perspective: Prevention and Therapeutic Potential of Phytochemicals for Targeting Cancer Stem Cells

Lung cancer is still one of the deadliest cancers, with over two million incidences annually. Prevention is regarded as the most efficient way to reduce both the incidence and death figures. Nevertheless, treatment should still be improved, particularly in addressing therapeutic resistance due to cancer stem cells—the assumed drivers of tumor initiation and progression. Phytochemicals in plant-based diets are thought to contribute substantially to lung cancer prevention and may be efficacious for targeting lung cancer stem cells. In this review, we collect recent literature on lung homeostasis, carcinogenesis, and phytochemicals studied in lung cancers. We provide a comprehensive overview of how normal lung tissue operates and relate it with lung carcinogenesis to redefine better targets for lung cancer stem cells. Nine well-studied phytochemical compounds, namely curcumin, resveratrol, quercetin, epigallocatechin-3-gallate, luteolin, sulforaphane, berberine, genistein, and capsaicin, are discussed in terms of their chemopreventive and anticancer mechanisms in lung cancer and potential use in the clinic. How the use of phytochemicals can be improved by structural manipulations, targeted delivery, concentration adjustments, and combinatorial treatments is also highlighted. We propose that lung carcinomas should be treated differently based on their respective cellular origins. Targeting quiescence-inducing, inflammation-dampening, or reactive oxygen species-balancing pathways appears particularly interesting.

Nicotine-derived NNK induces the stemness enrichment of CRC cells through regulating the balance of DUSP4-ERK1/2 feedback loop

Cigarette smoking has been considered as an independent risk factor for colorectal cancer (CRC) initiation and progression. In this study, we found that cigarette smoking was significantly associated with poor CRC differentiation (P = 0.040). Since studies have indicated that poorly differentiated tumors are more aggressive and metastasize earlier, leading to poorer prognosis; and cancer stem cells (CSCs) are largely responsible for tumor differentiation state, here we observed that the exposure of nicotine-derived 4-(methylnitrosamino)- 1-(3-pyridyl)- 1-butanone (NNK) promoted cell sphere formation and the expression of the stem cell markers, CD44, OCT4, C-MYC and NANOG in HCT8 and DLD-1 cells. Further colony formation assay, CCK-8 assay and tumor-bearing experiment showed that NNK exposure significantly increased the proliferative and growth ability of CRC cells. In mechanism, we found that NNK-activated ERK1/2 played an important role in enrichment of CRC stem cells and the up-regulation of DUSP4, a major negative regulator of ERK1/2. Moreover, DUSP4 up-regulation was essential for maintaining NNK-activated ERK1/2 in an appropriate level, which was an required event for NNK-induced stemness enrichment of CRC cells. Taken together, our findings provided a possible mechanistic insight into cigarette smoking-induced CRC progression.

TAp63α Is Involved in Tobacco Smoke-Induced Lung Cancer EMT and the Anti-cancer Activity of Curcumin via miR-19 Transcriptional Suppression

As a key risk factor for lung cancer, tobacco smoke (TS) influences several cellular processes, including epithelial-mesenchymal transition (EMT). TAp63α is a crucial transcription factor involved in tumor progression. The present study was designed to investigate the potential role and underlying mechanisms of TAp63α in TS-induced lung cancer EMT. We found that compared to normal tissues, the tumor tissues collected from lung cancer patients showed a lower level of TAp63α expression, along with downregulated E-cadherin expression and upregulated Vimentin expression. Results of treatment with TAp63α and TAp63α siRNA as well as with tumor growth factor-β (TGF-β) showed that TAp63α acted as a tumor suppressor gene, and its upregulated expression suppressed lung cancer EMT. Significantly, TS exposure altered expression of EMT-related markers, enhanced cell migratory and invasive capacities, and decreased the TAp63α expression level in lung cancer cells. Overexpression of TAp63α significantly alleviated TS-stimulated lung cancer EMT. Mechanistically, TAp63α expression transcriptionally reduced the miR-19 level, which resulted in the suppression of lung cancer EMT. Additionally, as a natural compound possessing anti-cancer effects, curcumin inhibited TS-induced lung cancer EMT by increasing TAp63α expression and reducing miR-19 expression. Collectively, our results indicate that TAp63α inhibits TS-induced lung cancer EMT via transcriptionally suppressing miR-19 and the inhibitory effect of TAp63α on miR-19 mediates the anti-cancer action of curcumin. These findings provide new insights into novel targets for lung cancer prevention.

Metabolism, absorption, and anti-cancer effects of sulforaphane: an update

Cancer is one of the most devastating diseases, and recently, a variety of natural compounds with preventive effects on cancer developments have been reported. Sulforaphane (SFN) is a potent anti-cancer isothiocyanate originating from Brassica oleracea (broccoli). SFN, mainly metabolized via mercapturic acid pathway, has high bioavailability and absorption. The present reviews mainly discussed the metabolism and absorption of SFN and newly discovered mechanistic understanding recent years for SFN's anti-cancer effects including promoting autophagy, inducing epigenetic modifications, suppressing glycolysis and fat metabolism. Moreover, its inhibitory effects on cancer stem cells and synergetic effects with other anti-cancer agents are also reviewed along with the clinical trials in this realm.

Nrf2-interacting nutrients and COVID-19: time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPARγ:Peroxisome proliferator-activated receptor, NFκB: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2α:Elongation initiation factor 2α). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT1R axis (AT1R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity.

Tobacco Smoke Plays an Important Role in Initiation and Development of Lung Cancer by Promoting the Characteristics of Cancer Stem Cells

Lung cancer is one of the most common causes of cancer-related deaths worldwide. Tobacco smoke is the single greatest risk factor of lung cancer. Although enormous progress in understanding the molecular mechanisms by which tobacco smoke leading to lung cancer has been made, the molecular pathogenesis remains largely unclear. Cancer stem cells have been implicated in cancer initiation, development, and drug resistance. In this review, we reviewed the relationship between tobacco smoke and lung cancer, the key role of cancer stem cells in lung cancer and other tumors. More importantly, we elucidate the mechanism of tobacco smoke promoting lung cancer from the perspective of the characteristics of cancer stem cells induced by tobacco smoke.

Life style factors, tumor cell plasticity and cancer stem cells

Cancers are heterogeneous tissues and a layer of heterogeneity is determined by the presence of cells showing stemness traits, known as cancer stem cells (CSCs). Evidence indicates that CSCs are important players in tumor development, progression and relapse. Oncogenic transformation of normal stem cells can give rise to CSCs, but CSCs can also originate from de-differentiation of bulk tumor cells. Thus, factors promoting the increase of normal stem cell pools or stimulating the acquisition of stemness features by tumor cells can have serious consequences on cancer origin and progression. In this review, we will first give an overview of the CSC model of cancer development and we will then discuss the role of life style factors, such as high caloric diet, alcohol drinking and smoking, on the widening of stem cell pools and the induction of CSC features in tumors. Finally, we will discuss some healthy life style factors that can help to prevent cancer.

The Antitumor Efficacy of β-Elemene by Changing Tumor Inflammatory Environment and Tumor Microenvironment

Inflammatory mediators and inflammatory cells in the inflammatory microenvironment promote the transformation of normal cells to cancer cells in the early stage of cancer, promote the growth and development of cancer cells, and induce tumor immune escape. The monomeric active ingredient β-elemene is extracted from the traditional Chinese medicine Curcuma wenyujin and has been proven to have good anti-inflammatory and antitumor activities in clinical applications for more than 20 years in China. Recent studies have found that this traditional Chinese medicine plays a vital role in macrophage infiltration and M2 polarization, as well as in regulating immune disorders, and it even regulates the transcription factors NF-κB and STAT3 to alter inflammation, tumorigenesis, and development. In addition, β-elemene regulates not only different inflammatory factors (such as TNF-α, IFN, TGF-β, and IL-6/10) but also oxidative stress in vivo and in vitro. The excellent anti-inflammatory and antitumor effects of β-elemene and its ability to alter the inflammatory microenvironment of tumors have been gradually elaborated. Although the study of monomeric active ingredients in traditional Chinese medicines is insufficient in terms of quality and quantity, the pharmacological effects of more active ingredients of traditional Chinese medicines will be revealed after β-elemene.

NOTCH4 maintains quiescent mesenchymal-like breast cancer stem cells via transcriptionally activating SLUG and GAS1 in triple-negative breast cancer

Rationale: NOTCH4 receptor has been implicated in triple-negative breast cancer (TNBC) development and breast cancer stem cell (BCSC) regulation. However, the potential of NOTCH4 as a BCSC marker and the underlying mechanisms remain unclear.

Methods: In this study, we determined the expression and activation of NOTCH4 in breast cancer cell lines and tumor samples by qRT-PCR, western blotting and immunohistochemistry. Subsequently, in vitro and in vivo serial dilution experiments were performed to demonstrate the application of NOTCH4 as an efficient mesenchymal-like (ML)-BCSC marker in TNBC. Stable overexpression of activated NOTCH4 and knockdown cell lines were established using lentivirus. RNA-seq and qRT-PCR were employed to reveal the downstream effectors of NOTCH4, followed by dual-luciferase reporter and chromatin immunoprecipitation assays to identify the genuine binding sites of NOTCH4 on SLUG and GAS1 promoters. Transwell assay, mammosphere formation and chemoresistance experiments were performed to determine the effects of SLUG, GAS1 and NOTCH4 on the mesenchymal-like characteristics of TNBC cells. Survival analysis was used to study the relation of NOTCH4, SLUG and GAS1 with prognosis of breast cancer.

Results: NOTCH4 is aberrantly highly expressed and activated in TNBC, which contributes to the maintenance of ML-BCSCs. Furthermore, NOTCH4 shows significantly higher efficiency in labeling ML-BCSCs than the currently commonly used CD24^-CD44⁺ marker. Mechanistically, NOTCH4 transcriptionally upregulates SLUG and GAS1 to promote EMT and quiescence in TNBC, respectively. The effects of NOTCH4 can be mimicked by simultaneous overexpression of SLUG and GAS1. Moreover, SLUG is also involved in harnessing GAS1, a known tumor suppressor gene, via its anti-apoptotic function.

Conclusions: Our findings reveal that the NOTCH4-SLUG-GAS1 circuit serves as a potential target for tumor intervention by overcoming stemness of ML-BCSCs and by conquering the lethal chemoresistance and metastasis of TNBC.

Targeted destruction of cancer stem cells using multifunctional magnetic nanoparticles that enable combined hyperthermia and chemotherapy

Cancer stem cells (CSCs) have been implicated in cancer recurrence and therapy resistance. Therefore, a CSC-targeted therapy that disrupts the maintenance and survival of CSCs may offer an effective approach in killing tumor cells in primary tumors and preventing the metastasis caused by CSCs. Nanoparticles (NPs)-based thermotherapy and/or chemotherapy are promising therapeutic methods for cancer treatment. Methods: A silica-based multifunctional NP system was present, which encapsulated a chemotherapeutic agent and magnetic cores and coated with a specific antibody against the lung CSCs. The efficacy of this novel therapeutic strategy was systematically studied both in vitro and in vivo by simultaneous activating the combined thermotherapy and chemotherapy via CSC-targeted NPs. Results: These NPs were systematically administered and activated for targeted chemotherapy and thermotherapy by using an externally applied alternating magnetic field (AMF). The antibody-modified NPs targeted to lung CSCs with enhanced cellular uptake in vitro and extended accumulation in tumor in vivo. Up to 98% of lung CSCs was killed in vitro with 30-min application of AMF, due to the combined effects of hyperthermia and chemotherapeutic drug treatment. In in vivo models, this combined therapy significantly suppressed tumor growth and metastasis in lung CSC xenograft-bearing mice, with minimal side effects and adverse effects. Conclusion: With good biocompatibility and targeting capability, the nanodrug delivery system may offer a promising clinical platform for the combined thermotherapy and chemotherapy. This work demonstrated the feasibility of developing multifunctional nanomedicine targeting CSCs for effective cancer treatment.