Piperlongumine Induces Apoptosis and Synergizes with Doxorubicin by Inhibiting the JAK2-STAT3 Pathway in Triple-Negative Breast Cancer

Enhanced Synergistic Efficacy Against Breast Cancer Cells Promoted by Co-Encapsulation of Piplartine and Paclitaxel in Acetalated Dextran Nanoparticles

Malignant breast tumors constitute the most frequent cancer diagnosis among women. Notwithstanding the progress in treatments, this condition persists as a major public health issue. Paclitaxel (PTX) is a first-line classical chemotherapeutic drug used as a single active pharmaceutical ingredient (API) or in combination therapy for breast cancer (BC) treatment. Adverse effects, poor water solubility, and inevitable susceptibility to drug resistance seriously limit its therapeutic efficacy in the clinic. Piplartine (PPT), an alkaloid extracted from Piper longum L., has been shown to inhibit cancer cell proliferation in several cell lines due to its pro-oxidant activity. However, PPT has low water solubility and bioavailability in vivo, and new strategies should be developed to optimize its use as a chemotherapeutic agent. In this context, the present study aimed to synthesize a series of acetalated dextran nanoparticles (Ac-Dex NPs) encapsulating PPT and PTX to overcome the limitations of PPT and PTX, maximizing their therapeutic efficacy and achieving prolonged and targeted codelivery of these anticancer compounds into BC cells. Biodegradable, pH-responsive, and biocompatible Ac-Dex NPs with diameters of 100-200 nm and spherical morphologies were formulated using a single emulsion method. Selected Ac-Dex NPs containing only PPT or PTX as well as those coloaded with PPT and PTX achieved excellent drug-loading capabilities (PPT, ca. 11-33%; PTX, ca. 2-14%) and high encapsulation efficiencies (PPT, ∼57-98%; PTX, ∼80-97%). Under physiological conditions (pH 7.4), these NPs exhibited excellent colloidal stability and were capable of protecting drug release, while under acidic conditions (pH 5.5) they showed structural collapse, releasing the therapeutics in an extended manner. Cytotoxicity results demonstrated that the encapsulation in Ac-Dex NPs had a positive effect on the activities of both PPT and PTX against the MCF-7 human breast cancer cell line after 48 h of treatment, as well as toward MDA-MB-231 triple-negative BC cells. PPT/PTX@Ac-Dex NPs were significantly more cytotoxic (IC50/PPT = 0.25-1.77 μM and IC50/PTX = 0.07-0.75 μM) and selective (SI = 2.9-6.7) against MCF-7 cells than all the control therapeutic agents: free PPT (IC50 = 4.57 μM; SI = 1.2), free PTX (IC50 = 0.97 μM; SI = 1.0), the single-drug-loaded Ac-Dex NPs, and the physical mixture of both free drugs. All combinations of PPT and PTX resulted in pronounced synergistic antiproliferative effects in MCF-7 cells, with an optimal molar ratio of PPT to PTX of 2.3:1. PPT/PTX-2@Ac-Dex NPs notably promoted apoptosis, cell cycle arrest at the G2/M, accumulation of intracellular reactive oxygen species (ROS), and combined effects from both PPT and PTX on the microtubule network of MCF-7 cells. Overall, the combination of PTX and PPT in pH-responsive Ac-Dex NPs may offer great potential to improve the therapeutic efficacy, overcome the limitations, and provide effective simultaneous delivery of these therapeutics for BC treatment.

Advances in the Understanding of the Pathogenesis of Triple-Negative Breast Cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is a heterogeneous disease characterized by high aggressiveness, high malignancy, and poor prognosis compared to other breast cancer subtypes.

OBJECTIVE

This review aims to explore recent advances in understanding TNBC and to provide new insights and potential references for clinical treatment.

METHODS

We examined current literature on TNBC to analyze molecular subtypes, genetic mutations, signaling pathways, mechanisms of drug resistance, and emerging therapies.

RESULTS

Findings highlight key aspects of TNBC's molecular subtypes, relevant mutations, and pathways, alongside emerging treatments that target drug resistance mechanisms.

CONCLUSION

These insights into TNBC pathogenesis may help guide future therapeutic strategies and improve clinical outcomes for patients with TNBC.

Piperlongumine in combination with EGFR tyrosine kinase inhibitors for the treatment of lung cancer cells

Objectives

EGFR tyrosine kinase inhibitor (EGFR-TKI) therapies such as erlotinib and gefitinib are approved for the treatment of non-small cell lung cancer (NSCLC). However, the high incidence of acquired resistance to these EGFR-TKIs may preclude their effectiveness. Piperlongumine (PPL), an extract from the long pepper fruit (Piper longum), has been shown to possess anticancer properties. The purpose of the study was to investigate piperlongumine as an anticancer agent and to study a combination treatment approach with EGFR-TKIs against lung cancer cells.

Methods

Anticancer efficacy of PPL, erlotinib (ERL), gefitinib (GEF), and cisplatin (CIS) were investigated in H1299 and H1975 cell lines. Cells were treated with PPL, ERL, GEF, and CIS alone, and in combination, cell viability was determined after 72 h. The mechanism of PPL-induced cytotoxicity was investigated via reactive oxygen species (ROS) induction, and apoptosis induction using acridine orange/ethidium bromide staining and flow cytometry. The effect of treatment on EGFR-mediated oncogenic signaling was investigated by immunoblotting for mitogenic and apoptotic markers.

Results

PPL exhibited a potent cytotoxic effect in H1299 and H1975 cells compared to ERL, GEF, and CIS. Combination treatments of PPL with GEF and ERL showed significant reductions in cancer cells compared to control in both cell lines, which were associated with apoptotic induction, but without significant ROS induction. Compared to control, PPL with GEF significantly increased apoptotic cell death in H1975as confirmed with flow cytometry. Treatment with PPL alone and in combination induced anti-mitogenic and apoptotic responses at the molecular level.

Conclusion

PPL sensitized lung cancer cells to EGFR-TKI and induced potent cytotoxic effects at low concentrations.

Applications of pyroptosis activators in tumor immunotherapy

Contemporary progress in tumor immunotherapy has solidified its role as an effective approach in combating cancer. Nonetheless, the prevalent "immune cold" state within the tumor microenvironment poses a substantial barrier to its efficacy. Addressing this, pyroptosis-a gasdermin-mediated programmed cell death characterized by its inflammatory profile-emerges as a crucial mechanism. It catalyzes the release of vast quantities of pro-inflammatory cytokines and immunogens, potentially transforming immunosuppressive "cold" tumors into reactive "hot" ones. Herein, we will initially present an overview of pyroptosis as a distinct form of cell death, along with its molecular mechanisms. Subsequently, we will focus on introducing how pyroptosis activators are utilized in the field of tumor immunotherapy. Insights gained from applications of pyroptosis activators in tumor immunotherapy could lead to the development of safe and efficient pyroptosis activators, significantly enriching the arsenal for tumor immunotherapy.

Design, synthesis, and biological studies of nitric oxide-donating piperlongumine derivatives triggered by lysyl oxidase as anti-triple negative breast cancer agents

Nitric oxide (NO) is an important gas messenger molecule with a wide range of biological functions. High concentration of NO exerts promising antitumor effects and is regarded as one of the hot spots in cancer research, that have limitations in their direct application due to its gaseous state, short half-life (seconds) and high reactivity. Lysyl oxidase (LOX) is a copper-dependent amine oxidase that is responsible for the covalent bonding between collagen and elastin and promotes tumor cell invasion and metastasis. The overexpression of LOX in triple-negative breast cancer (TNBC) makes it an attractive target for TNBC therapy. Herein, novel NO donor prodrug molecules were designed and synthesized based on the naturally derived piperlongumine (PL) skeleton, which can be selectively activated by LOX to release high concentrations of NO and PL derivatives, both of them play a synergistic role in TNBC therapy. Among them, the compound TM-1 selectively released NO in highly invasive TNBC cells (MDA-MB-231), and TM-1 was also confirmed as a potential TNBC cell line inhibitor with an inhibitory concentration of 2.274 μM. Molecular docking results showed that TM-1 had a strong and selective binding affinity with LOX protein.

Reversal of cisplatin resistance in oral squamous cell carcinoma by piperlongumine loaded smart nanoparticles through inhibition of Hippo-YAP signaling pathway

Cisplatin alone or in combination with 5FU and docetaxel is the preferred chemotherapy regimen for advanced-stage OSCC patients. However, its use has been linked to recurrence and metastasis due to the development of drug resistance. Therefore, sensitization of cancer cells to conventional chemotherapeutics can be an effective strategy to overcome drug resistance. Piperlongumine (PL), an alkaloid, have shown anticancer properties and sensitizes numerous neoplasms, but its effect on OSCC has not been explored. However, low aqueous solubility and poor pharmacokinetics limit its clinical application. Therefore, to improve its therapeutic efficacy, we developed piperlongumine-loaded PLGA-based smart nanoparticles (smart PL-NPs) that can rapidly release PL in an acidic environment of cancer cells and provide optimum drug concentrations to overcome chemoresistance. Our results revealed that smart PL-NPs has high cellular uptake in acidic environment, facilitating the intracellular delivery of PL and sensitizing cancer cells to cisplatin, resulting in synergistic anticancer activity in vitro by increasing DNA damage, apoptosis, and inhibiting drug efflux. Further, we have mechanistically explored the Hippo-YAP signaling pathway, which is the critical mediator of chemoresistance, and investigated the chemosensitizing effect of PL in OSCC. We observed that PL alone and in combination with cisplatin significantly inhibits the activation of YAP and its downstream target genes and proteins. In addition, the combination of cisplatin with smart PL-NPs significantly inhibited tumor growth in two preclinical models (patient-derived cell based nude mice and zebrafish xenograft). Taken together, our findings suggest that smart PL-NPs with cisplatin will be a novel formulation to reverse cisplatin resistance in patients with advanced OSCC.

Piperlongumine: the amazing amide alkaloid from Piper in the treatment of breast cancer

Piperlongumine (PL), an alkaloid found primarily in the fruits and roots of the plant Piper longum L. (Piperaceae), is a natural compound that exhibits potent activity against various cancer cell proliferation. The most frequently caused malignancy in women globally, breast cancer (BC), has been demonstrated to be significantly inhibited by PL. Apoptosis, cell cycle arrest, increased ROS generation, and changes in the signalling protein's expression are all caused by the numerous signalling pathways that PL impacts. Since BC cells resist conventional chemotherapeutic drugs (doxorubicin, docetaxel etc.), researchers have shown that the drugs in combination with PL can exhibit a synergistic effect, greater than the effects of the drug or PL alone. Recently, techniques for drug packaging based on nanotechnology have been employed to improve PL release. The review has presented an outline of the chemistry of PL, its molecular basis in BC, its bioavailability, toxicity, and nanotechnological applications. An attempt to understand the future prospects and direction of research about the compound has also been discussed.

Potential therapeutic targets of the JAK2/STAT3 signaling pathway in triple-negative breast cancer

Triple-negative breast cancer (TNBC) poses a significant clinical challenge due to its propensity for metastasis and poor prognosis. TNBC evades the body's immune system recognition and attack through various mechanisms, including the Janus Kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. This pathway, characterized by heightened activity in numerous solid tumors, exhibits pronounced activation in specific TNBC subtypes. Consequently, targeting the JAK2/STAT3 signaling pathway emerges as a promising and precise therapeutic strategy for TNBC. The signal transduction cascade of the JAK2/STAT3 pathway predominantly involves receptor tyrosine kinases, the tyrosine kinase JAK2, and the transcription factor STAT3. Ongoing preclinical studies and clinical research are actively investigating this pathway as a potential therapeutic target for TNBC treatment. This article comprehensively reviews preclinical and clinical investigations into TNBC treatment by targeting the JAK2/STAT3 signaling pathway using small molecule compounds. The review explores the role of the JAK2/STAT3 pathway in TNBC therapeutics, evaluating the benefits and limitations of active inhibitors and proteolysis-targeting chimeras in TNBC treatment. The aim is to facilitate the development of novel small-molecule compounds that target TNBC effectively. Ultimately, this work seeks to contribute to enhancing therapeutic efficacy for patients with TNBC.

Natural STAT3 Inhibitors for Cancer Treatment: A Comprehensive Literature Review

Cancer is one of the leading causes of mortality and morbidity worldwide, affecting millions of people physically and financially every year. Over time, many anticancer treatments have been proposed and studied, including synthetic compound consumption, surgical procedures, or grueling chemotherapy. Although these treatments have improved the daily life quality of patients and increased their survival rate and life expectancy, they have also shown significant drawbacks, including staggering costs, multiple side effects, and difficulty in compliance and adherence to treatment. Therefore, natural compounds have been considered a possible key to overcoming these problems in recent years, and thorough research has been done to assess their effectiveness. In these studies, scientists have discovered a meaningful interaction between several natural materials and signal transducer and activator of transcription 3 molecules. STAT3 is a transcriptional protein that is vital for cell growth and survival. Mechanistic studies have established that activated STAT3 can increase cancer cell proliferation and invasion while reducing anticancer immunity. Thus, inhibiting STAT3 signaling by natural compounds has become one of the favorite research topics and an attractive target for developing novel cancer treatments. In the present article, we intend to comprehensively review the latest knowledge about the effects of various organic compounds on inhibiting the STAT3 signaling pathway to cure different cancer diseases.

Overcoming Acquired Drug Resistance to Cancer Therapies through Targeted STAT3 Inhibition

Anti-neoplastic agents for cancer treatment utilize many different mechanisms of action and, when combined, can result in potent inhibition of cancer growth. Combination therapies can result in long-term, durable remission or even cure; however, too many times, these anti-neoplastic agents lose their efficacy due to the development of acquired drug resistance (ADR). In this review, we evaluate the scientific and medical literature that elucidate STAT3-mediated mechanisms of resistance to cancer therapeutics. Herein, we have found that at least 24 different anti-neoplastic agents-standard toxic chemotherapeutic agents, targeted kinase inhibitors, anti-hormonal agents, and monoclonal antibodies-that utilize the STAT3 signaling pathway as one mechanism of developing therapeutic resistance. Targeting STAT3, in combination with existing anti-neoplastic agents, may prove to be a successful therapeutic strategy to either prevent or even overcome ADR to standard and novel cancer therapies.

STAT family of transcription factors in breast cancer: Pathogenesis and therapeutic opportunities and challenges

Breast cancer is the most commonly diagnosed cancer and second-leading cause of cancer deaths in women. Breast cancer stem cells (BCSCs) promote metastasis and therapeutic resistance contributing to tumor relapse. Through activating genes important for BCSCs, transcription factors contribute to breast cancer metastasis and therapeutic resistance, including the signal transducer and activator of transcription (STAT) family of transcription factors. The STAT family consists of six major isoforms, STAT1, STAT2, STAT3, STAT4, STAT5, and STAT6. Canonical STAT signaling is activated by the binding of an extracellular ligand to a cell-surface receptor followed by STAT phosphorylation, leading to STAT nuclear translocation and transactivation of target genes. It is important to note that STAT transcription factors exhibit diverse effects in breast cancer; some are either pro- or anti-tumorigenic while others maintain dual, context-dependent roles. Among the STAT transcription factors, STAT3 is the most widely studied STAT protein in breast cancer for its critical roles in promoting BCSCs, breast cancer cell proliferation, invasion, angiogenesis, metastasis, and immune evasion. Consequently, there have been substantial efforts in developing cancer therapeutics to target breast cancer with dysregulated STAT3 signaling. In this comprehensive review, we will summarize the diverse roles that each STAT family member plays in breast cancer pathobiology, as well as, the opportunities and challenges in pharmacologically targeting STAT proteins and their upstream activators in the context of breast cancer treatment.

Role of STAT3 in the initiation, progression, proliferation and metastasis of breast cancer and strategies to deliver JAK and STAT3 inhibitors

INTRODUCTION

Breast cancer (BC) accounts for the majority of cancers among the female population. Anomalous activation of various signaling pathways has become an issue of concern. The JAK-STAT signaling pathway is activated in numerous cancers, including BC. STAT3 is widely involved in BCs, as 40 % of BCs display phosphorylated STAT3. JAK-STAT signaling is crucial for proliferation, survival, metastasis and other cellular events associated with the tumor microenvironment. Hence, targeting this pathway has become an area of interest among researchers.

KEY FINDINGS

This review article focuses on the role of STAT3 in the initiation, proliferation, progression and metastasis of BC. The roles of various phytochemicals, synthetic molecules and biologicals against JAK-STAT and STAT3 in various cancers have been discussed, with special emphasis on BC.

SIGNIFICANCE

JAK and STAT3 are involved in various phases from initiation to metastasis, and targeting this pathway is a promising approach to inhibit the various stages of BC development and to prevent metastasis. A number of phytochemicals and synthetic and biological molecules have demonstrated potential inhibitory effects on JAK and STAT3, thereby paving the way for the development of better therapeutics against BC.

STAT signaling as a target for intervention: from cancer inflammation and angiogenesis to non-coding RNAs modulation

As a landmark, scientific investigation in cytokine signaling and interferon-related anti-viral activity, signal transducer and activator of transcription (STAT) family of proteins was first discovered in the 1990s. Today, we know that the STAT family consists of several transcription factors which regulate various molecular and cellular processes, including proliferation, angiogenesis, and differentiation in human carcinoma. STAT family members play an active role in transducing signals from cell membrane to nucleus through intracellular signaling and thus activating gene transcription. Additionally, they are also associated with the development and progression of human cancer by facilitating inflammation, cell survival, and resistance to therapeutic responses. Accumulating evidence suggests that not all STAT proteins are associated with the progression of human malignancy; however, STAT3/5 are constitutively activated in various cancers, including multiple myeloma, lymphoma, breast cancer, prostate hepatocellular carcinoma, and non-small cell lung cancer. The present review highlights how STAT-associated events are implicated in cancer inflammation, angiogenesis and non-coding RNA (ncRNA) modulation to highlight potential intervention into carcinogenesis-related cellular processes.

Integrating UPLC-HR-MS/MS, Network Pharmacology, and Experimental Validation to Uncover the Mechanisms of Jin'gan Capsules against Breast Cancer

In the theory of traditional Chinese medicine (TCM), "liver-qi" stagnation and heat-induced toxicity represent the main etiologies of breast cancer. Recently, several TCMs with heat-clearing and detoxification efficacy have shown inhibitory effects on breast cancer. Jin'gan capsules (JGCs), initially approved to treat colds in China, are a heat-clearing and detoxification TCM formula. However, the anticancer activity of JGCs against breast cancer and its underlying mechanisms remain unclear. First, we assessed the antiproliferative activity of JGCs in breast cancer cell lines and evaluated their effects on cell apoptosis and the cell cycle by flow cytometry. Furthermore, we identified the potential bioactive components of JGCs and their corresponding target genes and constructed a bioactive compound-target interaction network by ultra-performance liquid chromatography-high-resolution tandem mass spectrometry (UPLC-HR-MS/MS) and network pharmacology analysis. Finally, the underlying mechanism was investigated through gene function enrichment analysis and experimental validation. We found that JGCs significantly inhibited breast cancer cell growth with IC₅₀ values of 0.56 ± 0.03, 0.16 ± 0.03, and 0.94 ± 0.09 mg/mL for MDA-MB-231, MDA-MB-468, and MCF-7, respectively. In addition, JGC treatment dramatically induced apoptosis and S phase cell cycle arrest in breast cancer cells. Western blot analysis confirmed that JGCs could regulate the protein levels of apoptosis- and cell cycle-related genes. Utilizing UPLC-HR-MS/MS analysis and network pharmacology, we identified 7 potential bioactive ingredients in JGCs and 116 antibreast cancer targets. Functional enrichment analysis indicated that the antitumor effects of JGCs were strongly associated with apoptosis and the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway. Western blot analysis validated that JGC treatment markedly decreased the expression levels of p-JAK2, p-STAT3, and STAT3. Our findings suggest that JGCs suppress breast cancer cell proliferation and induce cell cycle arrest and apoptosis partly by inhibiting the JAK2/STAT3 signaling pathway, highlighting JGCs as a potential therapeutic candidate against breast cancer.

Meta analysis of bioactive compounds, miRNA, siRNA and cell death regulators as sensitizers to doxorubicin induced chemoresistance

Cancer has presented to be the most challenging disease, contributing to one in six mortalities worldwide. The current treatment regimen involves multiple rounds of chemotherapy administration, alone or in combination. The treatment has adverse effects including cardiomyopathy, hepatotoxicity, and nephrotoxicity. In addition, the development of resistance to chemo has been attributed to cancer relapse and low patient overall survivability. Multiple drug resistance development may be through numerous factors such as up-regulation of drug transporters, drug inactivation, alteration of drug targets and drug degradation. Doxorubicin is a widely used first line chemotherapeutic drug for a myriad of cancers. It has multiple intracellular targets, DNA intercalation, adduct formation, topoisomerase inhibition, iron chelation, reactive oxygen species generation and promotes immune mediated clearance of the tumor. Agents that can sensitize the resistant cancer cells to the chemotherapeutic drug are currently the focus to improve the clinical efficiency of cancer therapy. This review summarizes the recent 10-year research on the use of natural phytochemicals, inhibitors of apoptosis and autophagy, miRNAs, siRNAs and nanoformulations being investigated for doxorubicin chemosensitization.

Piperlongumine combined with vitamin C as a new adjuvant therapy against gastric cancer regulates the ROS-STAT3 pathway

OBJECTIVE

To investigate the effects of piperlongumine (PL) and vitamin C (VC) on signal transducer and activator of transcription 3 (STAT3) signalling in gastric cancer cell lines.

METHODS

In vivo tumour xenograft anticancer assays were undertaken to confirm the anticancer activity of PL. Cell viability, flow cytometry and Western blot assays were undertaken to evaluate the anticancer effects of PL, VC and combinations of PL and VC in AGS and KATO III cells.

RESULTS

Both PL and VC induced apoptosis and inhibited cell proliferation in AGS and KATO III cells. These effects were dependent on reactive oxygen species (ROS). PL effectively suppressed STAT3 activation while VC caused abnormal activation of STAT3. The combination of PL and VC exhibited a stronger apoptotic effect compared with either agent alone. PL reversed the abnormal activation of STAT3 by VC, which could be a key to their synergistic effect.

CONCLUSIONS

PL combined with VC exhibited a stronger anticancer effect by regulating the ROS-STAT3 pathway, suggesting that this combination might be a potential adjuvant therapy for gastric cancer.

Modulation of TLR/NF-κB/NLRP Signaling by Bioactive Phytocompounds: A Promising Strategy to Augment Cancer Chemotherapy and Immunotherapy

Background

Tumors often progress to a more aggressive phenotype to resist drugs. Multiple dysregulated pathways are behind this tumor behavior which is known as cancer chemoresistance. Thus, there is an emerging need to discover pivotal signaling pathways involved in the resistance to chemotherapeutic agents and cancer immunotherapy. Reports indicate the critical role of the toll-like receptor (TLR)/nuclear factor-κB (NF-κB)/Nod-like receptor pyrin domain-containing (NLRP) pathway in cancer initiation, progression, and development. Therefore, targeting TLR/NF-κB/NLRP signaling is a promising strategy to augment cancer chemotherapy and immunotherapy and to combat chemoresistance. Considering the potential of phytochemicals in the regulation of multiple dysregulated pathways during cancer initiation, promotion, and progression, such compounds could be suitable candidates against cancer chemoresistance.

Objectives

This is the first comprehensive and systematic review regarding the role of phytochemicals in the mitigation of chemoresistance by regulating the TLR/NF-κB/NLRP signaling pathway in chemotherapy and immunotherapy.

Methods

A comprehensive and systematic review was designed based on Web of Science, PubMed, Scopus, and Cochrane electronic databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to include papers on TLR/NF-κB/NLRP and chemotherapy/immunotherapy/chemoresistance by phytochemicals.

Results

Phytochemicals are promising multi-targeting candidates against the TLR/NF-κB/NLRP signaling pathway and interconnected mediators. Employing phenolic compounds, alkaloids, terpenoids, and sulfur compounds could be a promising strategy for managing cancer chemoresistance through the modulation of the TLR/NF-κB/NLRP signaling pathway. Novel delivery systems of phytochemicals in cancer chemotherapy/immunotherapy are also highlighted.

Conclusion

Targeting TLR/NF-κB/NLRP signaling with bioactive phytocompounds reverses chemoresistance and improves the outcome for chemotherapy and immunotherapy in both preclinical and clinical stages.

Polydatin down-regulates the phosphorylation level of STAT3 and induces pyroptosis in triple-negative breast cancer mice with a high-fat diet

Background

To explore the impact of polydatin on mice with triple-negative breast cancer (TNBC) receiving a high-fat diet, as well as the underlying processes.

Methods

A total of 40 female Balb/c mice were randomly separated into 4 groups (4T1 + polydatin + fat diet group, 4T1 + high-fat diet group, 4T1 + polydatin group, and 4T1 group). To establish the obese TNBC mouse model, TNBC was xenografted 1×10⁵ 4T1 cells/50 µL per mouse at the right fourth mammary fat pad under anesthesia and the mice were fed a high fat diet. When the experiment was completed, total plasma cholesterol (TC) and cancer antigen (CA)15-3 were measured. The enzyme-linked immunosorbent assay (ELISA) method was used detect CA15-3. Oil red O staining was used to observe the morphological changes. Western blot analysis and reverse transcription polymerase chain reaction (RT-PCR) were used to detect the corresponding protein expression and the messenger RNA (mRNA) level.

Results

Polydatin decreased the degree of fatty liver, as determined by oil red O staining. The TC level in the 4T1 + fat diet group was significantly higher, and it was decreased in the 4T1 + polydatin group. The results of ELISA showed that compared with the 4T1 group, CA15-3 was significantly increased in the 4T1 + fat diet group, and polydatin was shown to significantly reduce the expression of CA15-3. Polydatin inhibited p-JAK2 and p-STAT3 mRNA and protein levels. Polydatin increased pyroptosis-related gene mRNA and protein level.

Conclusions

We believe that polydatin can effectively reduce blood lipid levels in TNBC mice with a high-fat diet, and play an anticancer role in TNBC. The underlying mechanism may be related to the JAK2/STAT3 signaling pathway and pyroptosis in TNBC. Our results contribute to validating the traditional use of polydatin in the treatment of TNBC with hyperlipidemia.

Fish Oil and Selenium with Doxorubicin Modulates Expression of Fatty Acid Receptors and Selenoproteins, and Targets Multiple Anti-Cancer Signaling in Triple-negative Breast Cancer Tumors

Omega-3 fatty acids from fish oil (FO) and selenium (Se) potentiate some conventional therapies and have anticancer immune potential. This study aims to determine whether FO/Se modulates G-protein-coupled polyunsaturated fatty acid receptors (GPR-40 and GPR-120) and selenoproteins (Sel-H, Sel-W, and GPx4), and increases the therapeutic effect of doxorubicin in a dose-dependent manner on triple-negative breast cancer (TNBC) mouse. Mice were randomized into 5 groups (n = 7/group) and treated with physiological saline (control), low-dose doxorubicin, and doxorubicin in combination with low, medium, or high doses of FO/Se. The expression of signaling molecules in tumors was determined by measuring either mRNA or protein expression. Compared with doxorubicin alone, combination treatment resulted in lower tumor sizes and fewer overall metastasis, lower GPR-40 mRNA levels, and higher expression of all selenoproteins. Doxorubicin-FO/Se combination treatment decreased expression of membrane EGFR and FGFR, down-regulated downstream PI3K/AKT/mTOR, MAPK/ERK, and JAK2/c-Src/STAT3 signaling, increased tumor suppressor PTEN/TSC1/TSC2 expression and P53 activation, and suppressed oncogenic transcription factor expression. Dose-dependent inhibition of proliferation index Ki-67, cell cycle, and stem-cell-related markers were observed. Decreased immune check-points PD-L1/CTLA-4/Foxp3/CD86 and increased PD-1/CD28/IL-2 expression was also found. These observations suggest that the nutritional supplements FO/Se increase the chemotherapeutic efficacy of doxorubicin against TNBC by modulating GPR-40 and selenoprotein and targeting multiple signaling pathways in tumor tissues.

STAT3 pathway as a molecular target for resveratrol in breast cancer treatment

Signal transducer and activator of transcription 3 (STAT3) induces breast cancer malignancy. Recent clinical and preclinical studies have demonstrated an association between overexpressed and activated STAT3 and breast cancer progression, proliferation, metastasis, and chemoresistance. Resveratrol (RES), a naturally occurring phytoalexin, has demonstrated anti-cancer activity in several disease models. Furthermore, RES has also been shown to regulate the STAT3 signaling cascade via its anti-oxidant and anti-inflammatory effects. In the present review, we describe the STAT3 cascade signaling pathway and address the therapeutic targeting of STAT3 by RES as a tool to mitigate breast cancer.

The signaling pathways and targets of traditional Chinese medicine and natural medicine in triple-negative breast cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Triple-negative breast cancer (TNBC) has a poorer prognosis than other subtypes due to its strong invasion and higher risk of distant metastasis. Traditional Chinese medicine (TCM) and natural medicine have the unique advantages of multitargets and small side-effects and may be used as long-term complementary and alternative therapies.

AIM OF THE REVIEW

The present article summarizes the classical signaling pathways and potential targets by the action of TCM and natural medicine (including extracts, active constituents and formulas) on TNBC and provides evidence for its clinical efficacy.

METHODS

The literature information was acquired from the scientific databases PubMed, Web of Science and CNKI from January 2010 to June 2020, and it was designed to elucidate the internal mechanism and role of TCM and natural medicine in the treatment of TNBC. The search key words included "Triple negative breast cancer" or "triple negative breast carcinoma", "TNBC" and "traditional Chinese medicine" or "Chinese herbal medicine", "medicinal plant", "natural plant", and "herb".

RESULTS

We described the antitumor activity of TCM and natural medicine in TNBC based on different signaling pathways. Plant medicine and herbal formulas regulated the related gene and protein expression via pathways such as PI3K/AKT/mTOR, MAPK and Wnt/β-catenin, which inhibit the growth, proliferation, migration, invasion and metastasis of TNBC cells.

CONCLUSION

The inhibitory effect of TCM and natural medicine on tumors was reflected in multiple levels and multiple pathways, providing reasonable evidence for new drug development. To make TCM and natural medicine widely and flexibly used in clinical practice, the efficacy, safety and mechanism of action need more in-depth experimental research.

JAK2 expression is correlated with the molecular and clinical features of breast cancer as a favorable prognostic factor

Janus kinases are a family of non-receptor tyrosine kinases involved in autoimmune diseases and malignancies. In breast cancer, the immune related role of JAK2 remains unclear. We aimed to investigate its role at transcriptome level and its relationship with the clinical outcome of breast cancer. This study enrolled a total of 2994 breast cancer samples with transcriptome data, including 1090 samples from The Cancer Genome Atlas (TCGA) and 1904 from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC). JAK2 expression was significantly upregulated in both PR positive group (P < 0.01) and HER2 negative group (P < 0.01), and was correlated with American Joint Committee on Cancer (AJCC) stage and tumor malignancies of breast cancer. Functional enrichment analysis revealed that genes correlated with JAK2 were mainly involved in essential functions associated with immune response. Intriguingly, we investigated the association between JAK2 and immune modulators in pan-cancer, JAK2 expression was positively correlated with most of these immune modulators. In clinical aspect, higher expression of JAK2 was an independent indicator of favorable prognosis in breast cancer patients. The expression of JAK2 is tightly related to the pathology and molecular pathology of breast cancer, and synergistic with other checkpoint members thereby playing a specific role in regulating tumor immune microenvironment. To our knowledge, this is the largest and most comprehensive study characterizing the expression pattern of JAK2 and its special immune functions together with its prognostic values in breast cancer. These findings might shed novel sights for future research in cancer immunotherapy by targeting immune checkpoint molecules.

Piperlongumine inhibits head and neck squamous cell carcinoma proliferation by docking to Akt

Piperlongumine (PL) is a biologically active alkaloid isolated from the long pepper roots and widely used as a traditional medicine in Ayurvedic medicine. However, the mechanism of PL's effect on head and neck squamous cell carcinoma (HNSCC) is not well understood. We performed cell experiments to confirm PL's inhibitory effect on HNSCC and employing cisplatin as positive control. Next, we conducted bioinformatics to predict PL's potential targets and verified by western blotting. Molecular docking, Biacore experiment and kinase activity assays were applied to elucidate the mechanism by which PL inhibited target activity. In vivo efficacy was verified by xenotransplantation and immunohistochemistry. PL inhibited proliferation, promoted late apoptosis, arrested cell cycle and inhibited DNA replication of the HEp-2 and FaDu cell lines. Employing bioinformatics, we found that PL's target was Akt and PL attenuated Akt phosphorylation. We found from molecular docking, Biacore experiment and kinase activity assay that PL inhibited Akt activation by docking to Akt to restrain its activity. In addition, PL significantly inhibited the growth of xenograft tumors by down regulating the expression of p-Akt in vivo. This study provides new insights into the molecular functions of PL and indicate its potential as a therapeutic agent for HNSCC.

Therapeutic Potential of the Natural Compound S-Adenosylmethionine as a Chemoprotective Synergistic Agent in Breast, and Head and Neck Cancer Treatment: Current Status of Research

The present review summarizes the most recent studies focusing on the synergistic antitumor effect of the physiological methyl donor S-adenosylmethionine (AdoMet) in association with the main drugs used against breast cancer and head and neck squamous cell carcinoma (HNSCC), two highly aggressive and metastatic malignancies. In these two tumors the chemotherapy approach is recommended as the first choice despite the numerous side effects and recurrence of metastasis, so better tolerated treatments are needed to overcome this problem. In this regard, combination therapy with natural compounds, such as AdoMet, a molecule with pleiotropic effects on multiple cellular processes, is emerging as a suitable strategy to achieve synergistic anticancer efficacy. In this context, the analysis of studies conducted in the literature highlighted AdoMet as one of the most effective and promising chemosensitizing agents to be taken into consideration for inclusion in emerging antitumor therapeutic modalities such as nanotechnologies.

The Natural Alkaloid Piperlongumine Inhibits Metastatic Activity and Epithelial-to-Mesenchymal Transition of Triple-Negative Mammary Carcinoma Cells

In this study, we determined the effect of low dose piperlongumine on the motility/invasive capacity and epithelial-to-mesenchymal transition (EMT) of MDA-MB-231 triple-negative breast cancer (TNBC) cells and the metastasis of 4T1 mouse mammary carcinoma cells. MTT assays measured the effect of piperlongumine on TNBC cell growth. Motility/invasiveness were determined by gap closure/transwell assays. Western blotting assessed ZEB1, Slug, and matrix metalloproteinase (MMP) 9 expression. Interleukin (IL) 6 was detected by ELISA. MMP2, E-cadherin, and miR-200c expression was determined by real-time quantitative polymerase chain reaction. Reactive oxygen species (ROS) were measured by flow cytometry. The orthotopic 4T1 mouse model of breast cancer was used to examine metastasis. Piperlongumine-treated MDA-MB-231 cells showed reduced motility/invasiveness, decreased MMP2 and MMP9 expression, increased miR-200c expression, reduced IL-6 synthesis, decreased expression of ZEB1 and Slug, increased E-cadherin expression, and epithelial-like morphology. Piperlongumine also inhibited transforming growth factor β-induced ZEB1 and Slug expression. ROS accumulated in piperlongumine-treated cells, while changes in metastasis-associated gene expression were ablated by exogenous glutathione. Metastasis of 4T1 cells to the lungs of BALB/c mice was dramatically reduced in piperlongumine-treated animals. These findings reveal a previously unknown capacity of low dose piperlongumine to interfere with TNBC metastasis via an oxidative stress-dependent mechanism.

The Synergistic Effect of Piperlongumine and Sanguinarine on the Non-Small Lung Cancer

BACKGROUND

Cancers are one of the leading causes of deaths nowadays. The development of new treatment schemes for oncological diseases is an interesting direction in experimental medicine. Therefore, the evaluation of the influence of two alkaloids-piperlongumine (PL), sanguinarine (SAN) and their combination-on the basic life processes of the A549 cell line was considered reasonable.

METHODS

The aim was achieved by analyzing the cytotoxic effects of PL and SAN and their combination in the ratio of 4:1 on the induction of cell death, changes in the distribution of cell cycle phases, reorganization of cytoskeleton and metastatic potential of A549 cells. The versatility of the applied concentration ratio was evaluated in terms of other cancer cell lines: MCF-7, H1299 and HepG2.

RESULTS

The results obtained from the MTT assay indicated that the interaction between the alkaloids depends on the concentration and type of cells. Additionally, the compounds and their combination did not exhibit a cytotoxic effect against normal cells. The combined effects of PL and SAN increased apoptosis and favored metastasis inhibition.

CONCLUSION

Selected alkaloids exhibit a cytotoxic effect on A549 cells. In turn, treatment with the combination of PL and SAN in a 4:1 ratio indicates a synergistic effect and is associated with an increase in the level of reactive oxygen species (ROS).

Piperlongumine, a potent anticancer phytotherapeutic: Perspectives on contemporary status and future possibilities as an anticancer agent

Piperlongumine, a white to beige biologically active alkaloid/amide phytochemical, has high pharmacological relevance as an anticancer agent. Piperlongumine has several biological activities, including selective cytotoxicity against multiple cancer cells of different origins at a preclinical level. Several preclinical studies have documented the anticancer potential of piperlongumine through its targeting of multiple molecular mechanisms, such as cell cycle arrest, anti-angiogenesis, anti- invasive and anti-metastasis pathways, autophagy pathways, and intrinsic apoptotic pathways in vitro and in vivo. Mechanistically, piperlongumine inhibits cancer growth by resulting in the accumulation of intracellular reactive oxygen species, decreasing glutathione and chromosomal damage, or modulating key regulatory proteins, including PI3K, AKT, mTOR, NF-kβ, STATs, and cyclin D1. Furthermore, combined treatment with piperlongumine potentiates the anticancer activity of conventional chemotherapeutics and overcomes resistance to chemo- and radio- therapy. Nanoformulation of piperlongumine has been associated with increased aqueous solubility and bioavailability and lower toxicity, thus enhancing therapeutic efficacy in both preclinical and clinical settings. The current review highlights anticancer studies on the occurrence, chemical properties, chemopreventive mechanisms, toxicity, bioavailability, and pharmaceutical relevance of piperlongumine in vitro and in vivo.

Role of STAT3 signaling pathway in breast cancer

Breast cancer has grown to be the second leading cause of cancer-related deaths in women. Only a few treatment options are available for breast cancer due to the widespread occurrence of chemoresistance, which emphasizes the need to discover and develop new methods to treat this disease. Signal transducer and activator of transcription 3 (STAT3) is an early tumor diagnostic marker and is known to promote breast cancer malignancy. Recent clinical and preclinical data indicate the involvement of overexpressed and constitutively activated STAT3 in the progression, proliferation, metastasis and chemoresistance of breast cancer. Moreover, new pathways comprised of upstream regulators and downstream targets of STAT3 have been discovered. In addition, small molecule inhibitors targeting STAT3 activation have been found to be efficient for therapeutic treatment of breast cancer. This systematic review discusses the advances in the discovery of the STAT3 pathways and drugs targeting STAT3 in breast cancer. Video abstract.

Cucurbitacin E Inhibits Huh7 Hepatoma Carcinoma Cell Proliferation and Metastasis via Suppressing MAPKs and JAK/STAT3 Pathways

Cucurbitacin E (CuE), a highly oxygenated tetracyclic triterpene from Cucurbitaceae, has shown to exhibit potent cytotoxic and anti-proliferative properties against several human cancer cells. However, the underlying effects and mechanisms of CuE regarding hepatocellular carcinoma (HCC) have not been well understood. In the current study, unbiased RNA-sequencing (RNA-seq) and bioinformatics analysis was applied to elucidate the underlying molecular mechanism. CuE could significantly inhibit cell proliferation and migration of Huh7 cells, meanwhile CuE exhibited potent anti-angiogenic activity. RNA-seq analysis revealed that CuE negatively regulated 241 differentially expressed genes (DEGs) involved in multiple processes including cytoskeleton formation, angiogenesis and focal adhesion. Further analysis revealed that CuE effectually regulated diversified pharmacological signaling pathways such as MAPKs and JAK-STAT3. Our findings demonstrated the role of CuE in inhibiting proliferation and migration, providing an insight into the regulation of multiple signaling pathways as a new paradigm for anti-cancer treatment strategy.

Two Natural Alkaloids Synergistically Induce Apoptosis in Breast Cancer Cells by Inhibiting STAT3 Activation

Breast cancer has become a worldwide threat, and chemotherapy remains a routine treatment. Patients are forced to receive continuous chemotherapy and suffer from severe side effects and poor prognosis. Natural alkaloids, such as piperine (PP) and piperlongumine (PL), are expected to become a new strategy against breast cancer due to their reliable anticancer potential. In the present study, cell viability, flow cytometry, and Western blot assays were performed to evaluate the suppression effect of PP and PL, alone or in combination. Data showed that PP and PL synergistically inhibited breast cancer cells proliferation at lower doses, while only weak killing effect was observed in normal breast cells, indicating a good selectivity. Furthermore, apoptosis and STAT3 signaling pathway-associated protein levels were analyzed. We demonstrated that PP and PL in combination inhibit STAT3 phosphorylation and regulate downstream molecules to induce apoptosis in breast cancer cells. Taken together, these results revealed that inactivation of STAT3 was a novel mechanism with treatment of PP and PL, suggesting that combination application of natural alkaloids may be a potential strategy for prevention and therapy of breast cancer.

Piperlongumine potentiates the antitumor efficacy of oxaliplatin through ROS induction in gastric cancer cells

PURPOSE

Oxaliplatin is one of the most commonly used chemotherapeutic agents in the treatment of various cancers, including gastric cancer. It has, however, a narrow therapeutic index due to its toxicity and the occurrence of drug resistance. Therefore, there is a pressing need to develop novel therapies to potentiate the efficacy and reduce the toxicity of oxaliplatin. Piperlongumine (PL), an alkaloid isolated from Piper longum L., has recently been identified as a potent agent against cancer cells in vitro and in vivo. In the present study, we investigated whether PL can potentiate the antitumor effect of oxaliplatin in gastric cancer cells.

METHODS

Cellular apoptosis and ROS levels were analyzed by flow cytometry. Thioredoxin reductase 1 (TrxR1) activity in gastric cancer cells or tumor tissues was determined using an endpoint insulin reduction assay. Western blotting was used to analyze the expression levels of the indicated proteins. Nude mice xenograft models were used to test the effects of PL and oxaliplatin combinations on gastric cancer cell growth in vivo.

RESULTS

We found that PL significantly enhanced oxaliplatin-induced growth inhibition in both gastric and colon cancer cells. Moreover, we found that PL potentiated the antitumor effect of oxaliplatin by inhibiting TrxR1 activity. PL combined with oxaliplatin markedly suppressed the activity of TrxR1, resulting in the accumulation of ROS and, thereby, DNA damage induction and p38 and JNK signaling pathway activation. Pretreatment with antioxidant N-acetyl-L-cysteine (NAC) significantly abrogated the combined treatment-induced ROS generation, DNA damage and apoptosis. Importantly, we found that activation of the p38 and JNK signaling pathways prompted by PL and oxaliplatin was also reversed by NAC pretreatment. In vivo, we found that PL combined with oxaliplatin significantly suppressed tumor growth in a gastric cancer xenograft model, and effectively reduced the activity of TrxR1 in tumor tissues. Remarkably, we found that PL attenuated body weight loss evoked by oxaliplatin treatment.

CONCLUSIONS

Our data support a synergistic effect of PL and oxaliplatin and suggest that application of its combination may be more effective for the treatment of gastric cancer than oxaliplatin alone.