Inhibition of Murine Breast Cancer Metastases by Hydrophilic As4S4 Nanoparticles Is Associated With Decreased ROS and HIF-1α Downregulation

Hypoxia-inducible factor in breast cancer: role and target for breast cancer treatment

Globally, breast cancer stands as the most prevalent form of cancer among women. The tumor microenvironment of breast cancer often exhibits hypoxia. Hypoxia-inducible factor 1-alpha, a transcription factor, is found to be overexpressed and activated in breast cancer, playing a pivotal role in the anoxic microenvironment by mediating a series of reactions. Hypoxia-inducible factor 1-alpha is involved in regulating downstream pathways and target genes, which are crucial in hypoxic conditions, including glycolysis, angiogenesis, and metastasis. These processes significantly contribute to breast cancer progression by managing cancer-related activities linked to tumor invasion, metastasis, immune evasion, and drug resistance, resulting in poor prognosis for patients. Consequently, there is a significant interest in Hypoxia-inducible factor 1-alpha as a potential target for cancer therapy. Presently, research on drugs targeting Hypoxia-inducible factor 1-alpha is predominantly in the preclinical phase, highlighting the need for an in-depth understanding of HIF-1α and its regulatory pathway. It is anticipated that the future will see the introduction of effective HIF-1α inhibitors into clinical trials, offering new hope for breast cancer patients. Therefore, this review focuses on the structure and function of HIF-1α, its role in advancing breast cancer, and strategies to combat HIF-1α-dependent drug resistance, underlining its therapeutic potential.

Exploring novel strategies to improve anti-tumour efficiency: The potential for targeting reactive oxygen species

The cellular milieu in which malignant growths or cancer stem cells reside is known as the tumour microenvironment (TME). It is the consequence of the interactivity amongst malignant and non-malignant cells and directly affects cancer development and progression. Reactive oxygen species (ROS) are chemically reactive molecules that contain oxygen, they are generated because of numerous endogenous and external factors. Endogenous ROS produced from mitochondria is known to significantly increase intracellular oxidative stress. In addition to playing a key role in several biological processes both in healthy and malignant cells, ROS function as secondary messengers in cell signalling. At low to moderate concentrations, ROS serves as signalling transducers to promote cancer cell motility, invasion, angiogenesis, and treatment resistance. At high concentrations, ROS can induce oxidative stress, leading to DNA damage, lipid peroxidation and protein oxidation. These effects can result in cell death or trigger signalling pathways that lead to apoptosis. The creation of innovative therapies and cancer management techniques has been aided by a thorough understanding of the TME. At present, surgery, chemotherapy, and radiotherapy, occasionally in combination, are the most often used methods for tumour treatment. The current challenge that these therapies face is the lack of spatiotemporal application specifically at the lesion which results in toxic effects on healthy cells associated with off-target drug delivery and undesirably high doses. Nanotechnology can be used to specifically deliver various chemicals via nanocarriers to target tumour cells, thereby increasing the accumulation of ROS-inducing agents at the site of the tumour. Nanoparticles can be engineered to release ROS-inducing agents in a controlled manner to the TME that will in turn react with the ROS to either increase or decrease it, thereby improving antitumour efficiency. Nano-delivery systems such as liposomes, nanocapsules, solid lipid nanoparticles and nanostructured lipid carriers were explored for the up/down-regulation of ROS. This review will discuss the use of nanotechnology in targeting and altering the ROS in the TME.

Hypoxia: syndicating triple negative breast cancer against various therapeutic regimens

Triple-negative breast cancer (TNBC) is one of the deadliest subtypes of breast cancer (BC) for its high aggressiveness, heterogeneity, and hypoxic nature. Based on biological and clinical observations the TNBC related mortality is very high worldwide. Emerging studies have clearly demonstrated that hypoxia regulates the critical metabolic, developmental, and survival pathways in TNBC, which include glycolysis and angiogenesis. Alterations to these pathways accelerate the cancer stem cells (CSCs) enrichment and immune escape, which further lead to tumor invasion, migration, and metastasis. Beside this, hypoxia also manipulates the epigenetic plasticity and DNA damage response (DDR) to syndicate TNBC survival and its progression. Hypoxia fundamentally creates the low oxygen condition responsible for the alteration in Hypoxia-Inducible Factor-1alpha (HIF-1α) signaling within the tumor microenvironment, allowing tumors to survive and making them resistant to various therapies. Therefore, there is an urgent need for society to establish target-based therapies that overcome the resistance and limitations of the current treatment plan for TNBC. In this review article, we have thoroughly discussed the plausible significance of HIF-1α as a target in various therapeutic regimens such as chemotherapy, radiotherapy, immunotherapy, anti-angiogenic therapy, adjuvant therapy photodynamic therapy, adoptive cell therapy, combination therapies, antibody drug conjugates and cancer vaccines. Further, we also reviewed here the intrinsic mechanism and existing issues in targeting HIF-1α while improvising the current therapeutic strategies. This review highlights and discusses the future perspectives and the major alternatives to overcome TNBC resistance by targeting hypoxia-induced signaling.

Possible therapeutic targets for NLRP3 inflammasome-induced breast cancer

Inflammation plays a major role in the development and progression of breast cancer(BC). Proliferation, invasion, angiogenesis, and metastasis are all linked to inflammation and tumorigenesis. Furthermore, tumor microenvironment (TME) inflammation-mediated cytokine releases play a critical role in these processes. By recruiting caspase-1 through an adaptor apoptosis-related spot protein, inflammatory caspases are activated by the triggering of pattern recognition receptors on the surface of immune cells. Toll-like receptors, NOD-like receptors, and melanoma-like receptors are not triggered. It activates the proinflammatory cytokines interleukin (IL)-1β and IL-18 and is involved in different biological processes that exert their effects. The Nod-Like Receptor Protein 3 (NLRP3) inflammasome regulates inflammation by mediating the secretion of proinflammatory cytokines and interacting with other cellular compartments through the inflammasome's central role in innate immunity. NLRP3 inflammasome activation mechanisms have received much attention in recent years. Inflammatory diseases including enteritis, tumors, gout, neurodegenerative diseases, diabetes, and obesity are associated with abnormal activation of the NLRP3 inflammasome. Different cancer diseases have been linked to NLRP3 and its role in tumorigenesis may be the opposite. Tumors can be suppressed by it, as has been seen primarily in the context of colorectal cancer associated with colitis. However, cancers such as gastric and skin can also be promoted by it. The inflammasome NLRP3 is associated with breast cancer, but there are few specific reviews. This review focuses on the structure, biological characteristics and mechanism of inflammasome, the relationship between NLRP3 in breast cancer Non-Coding RNAs, MicroRNAs and breast cancer microenvironment, especially the role of NLRP3 in triple-negative breast cancer (TNBC). And the potential strategies of using NLRP3 inflammasome to target breast cancer, such as NLRP3-based nanoparticle technology and gene target therapy, are reviewed.

Role of mitochondrial stress and the NLRP3 inflammasome in lung diseases

BACKGROUND

As an organelle essential for intracellular energy supply, mitochondria are involved in intracellular metabolism and inflammation, and cell death. The interaction of mitochondria with the NLRP3 inflammasome in the development of lung diseases has been extensively studied. However, the exact mechanism by which mitochondria mediate the activation of the NLRP3 inflammasome and trigger lung disease is still unclear.

METHODS

The literatures related to mitochondrial stress, NLRP3 inflammasome and lung diseases were searched in PubMed.

RESULTS

This review aims to provide new insights into the recently discovered mitochondrial regulation of the NLRP3 inflammasome in lung diseases. It also describes the crucial roles of mitochondrial autophagy, long noncoding RNA, micro RNA, altered mitochondrial membrane potential, cell membrane receptors, and ion channels in mitochondrial stress and regulation of the NLRP3 inflammasome, in addition to the reduction of mitochondrial stress by nuclear factor erythroid 2-related factor 2 (Nrf2). The effective components of potential drugs for the treatment of lung diseases under this mechanism are also summarized.

CONCLUSION

This review provides a resource for the discovery of new therapeutic mechanisms and suggests ideas for the development of new therapeutic drugs, thus promoting the rapid treatment of lung diseases.

Multifunctional Nano-Realgar Hydrogel for Enhanced Glioblastoma Synergistic Chemotherapy and Radiotherapy: A New Paradigm of an Old Drug

Purpose

Realgar, as a kind of traditional mineral Chinese medicine, can inhibit multiple solid tumor growth and serve as an adjuvant drug in cancer therapy. However, the extremely low solubility and poor body absorptive capacity limit its application in clinical medicine. To overcome this therapeutic hurdle, realgar can here be fabricated into a nano-realgar hydrogel with enhanced chemotherapy and radiotherapy (RT) ability. Our objective is to evaluate the superior biocompatibility and anti-tumor activity of nano-realgar hydrogel.

Methods

We have successfully synthesized nano-realgar quantum dots (QDs) coupling with 6-AN molecules (NRA QDs) and further encapsulated with a pH-sensitive dextran hydrogel carrier with hyaluronic acid coating (DEX-HA gel) to promote bioavailability, eventually forming a multifunctional nano-realgar hydrogel (NRA@DH Gel). To better investigate the tumor therapy efficiency of the NRA@DH Gel, we have established the mice in situ bearing GL261 brain glioblastoma as animal models assigned to receive intratumor injection of NRA@DH Gel.

Results

The designed NRA@DH Gel as an antitumor drug can not only exert the prominent chemotherapy effect but also as a "sustainable reactive oxygen species (ROS) generator" can inhibit in the pentose phosphate pathway (PPP) metabolism and reduce the production of nicotinamide adenine dinucleotide phosphate (NADPH), thereby inhibiting the conversion of glutathione disulfide (GSSG) to glutathione (GSH), reducing GSH concentrations in tumor cells, triggering the accumulation of ROS, and finally enhancing the effectiveness of RT.

Conclusion

Through the synergistic effect of chemotherapy and RT, NRA@DH Gel effectively inhibited the proliferation and migration of tumor cells, suppressed tumor growth, improved motor coordination, and prolonged survival in tumor-bearing mice. Our work aims to improve the NRA@DH Gel-mediated synergistic chemotherapy and RT will endow a "promising future" for the old drug in clinically comprehensive applications.

Multi-faced roles of reactive oxygen species in anti-tumor T cell immune responses and combination immunotherapy

T cells play a central role in anti-tumor immunity, and reactive oxygen species (ROS) lie at the crossroad on the anti-tumor T cell responses. To activate efficient T cell immunity, a moderate level of ROS is needed, however, excessive ROS would cause toxicity to the T cells, because the improper level leads to the formation and maintenance of an immunosuppressive tumor microenvironment. Up to date, strategies that modulate ROS, either increasing or decreasing, have been widely investigated. Some of them are utilized in anti-tumor therapies, showing inevitable impacts on the anti-tumor T cell immunity with both obverse and reverse sides. Herein, the impacts of ROS-increasing and ROS-decreasing treatments on the T cell responses in the tumor microenvironment are reviewed and discussed. At the same time, outcomes of combination immunotherapies are introduced to put forward inspirations to unleash the potential of immunotherapies.

Role of hypoxia in inhibiting dendritic cells by VEGF signaling in tumor microenvironments: mechanism and application

The tumor microenvironment (TME) plays a central role in tumor initiation, development, immune escape, and clinical treatment. Hypoxia, an important characteristic of the TME, mediates vascular endothelial factor (VEGF) signaling through direct or indirect mechanisms. Directly, hypoxia promotes the expression of VEGF through hypoxia-inducible factor (HIF) induction. Indirectly, VEGF inhibits dendritic cell (DC) maturation and function by binding to VEGF receptors (VEGFRs) and co-receptors expressed on cell membranes. Additionally, HIF can bypass VEGF/VEGFR and activate downstream signaling factors to promote tumor development. Currently, DC vaccine, anti-HIF and anti-VEGF therapies are widely used in clinical treatment, but their long-term effects remain limited. Therefore, a further understanding of the effects of hypoxia and VEGF signaling on DCs will help in the development of innovative combination therapies and the identification of new targets.

Research on the effect of interfering with miRNA-155 on triple-negative breast cancer cells

BACKGROUND

Triple negative breast cancer (TNBC) is a poor prognosis breast cancer with the highest mutation rate and limited treatment options. MiR-155 is highly expressed in TNBC, but its role and potential mechanism in TNBC remain to be elucidated.

OBJECTIVE

The aim of this study is to examine the effect of interfering with miRNA-155 on the inflammatory pathway of NLRP 3 in TNBC (MDA-MB-231).

METHODS

MiRNA-155-specific interference (Si-miR-155) on MDA-MB-231 cell was manifested by transfection of miRNA-155 inhibitor. Meanwhile, blank control (Blank) and negative control (NC) were set. Cell growth and proliferation rate were detected by MTT; apoptosis rate were detected by flow cytometry; colony forming test was used to detected cell viability; cell migration ability was detected by Wound healing assay; TNF-α, IL-18, IL-6 and IL-1β levels were detected by ELISA. The mRNA of miRNA-155, NLRP3, ASC, caspase-1 and Ki67 were detected by qRT-PCR. The expression levels of NLRP3, caspase-1, ASC and Ki67 were detected by Western blotting.

RESULTS

The proliferation rate of Si-miRNA-155 group decreased, while the apoptosis rate increased significantly. After interfering with miRNA-155, the number of cancer cell colonies and the migration ability was decreased, and the secretion levels of IL-18, TNF-α, IL-6 and IL-1β were also inhibited. Moreover the mRNA and protein expression of NLRP3, caspase-1, ASC and Ki67 were significantly suppressed.

CONCLUSIONS

Interference with miRNA-155 can inhibit the NLRP3 pathway of MDA-MB-231 cells, as well as the proliferation, migration and inflammatory factor secretion of MDA-MB-231 cell, and can accelerate its apoptosis.

Nano-delivery systems focused on tumor microenvironment regulation and biomimetic strategies for treatment of breast cancer metastasis

Breast cancer metastasis and recurrence accounts for vast majority of breast cancer-induced mortality. Tumor microenvironment (TME) plays an important role at each step of metastasis, evasion of immunosurveillance, and therapeutic resistance. Consequently, TME-targeting alternatives to traditional therapies focused on breast cancer cells are gaining increasing attention. These new therapies involve the use of tumor cells, and key TME components or secreted bioactive molecules as therapeutic targets, alone or in combination. Recently, TME-related nanoparticles have been developed to deliver various agents, such as bioactive ingredients extracted from natural sources or chemotherapeutic agents, genes, proteins, small interfering RNAs, and vaccines; they have shown great therapeutic potential against breast cancer metastasis. Among various types of nanoparticles, biomimetic nanovesicles are a promising means of addressing the limitations of conventional nanocarriers. This review highlights various nanoparticles related to or mediated by TME according to the key TME components responsible for metastasis. Furthermore, TME-related biomimetic nanoparticles against breast cancer metastasis have garnered attention owing to their promising efficiency, especially in payload delivery and therapeutic action. Here, we summarize recent representative studies on nanoparticles related to cancer-associated fibroblasts, extracellular matrix, endothelial cells, angiogenesis, and immune cells, as well as advanced biomimetic nanoparticles. Future challenges and opportunities in the field are also discussed.

Heavy metal associated health hazards: An interplay of oxidative stress and signal transduction

Heavy metal-induced cellular and organismal toxicity have become a major health concern in biomedical science. Indiscriminate use of heavy metals in different sectors, such as, industrial-, agricultural-, healthcare-, cosmetics-, and domestic-sectors has contaminated environment matrices and poses a severe health concern. Xenobiotics mediated effect is a ubiquitous cellular response. Oxidative stress is one such prime cellular response, which is the result of an imbalance in the redox system. Further, oxidative stress is associated with macromolecular damages and activation of several cell survival and cell death pathways. Epidemiological as well as laboratory data suggest that oxidative stress-induced cellular response following heavy metal exposure is linked with an increased risk of neoplasm, neurological disorders, diabetes, infertility, developmental disorders, renal failure, and cardiovascular disease. During the recent past, a relation among heavy metal exposure, oxidative stress, and signaling pathways have been explored to understand the heavy metal-induced toxicity. Heavy metal-induced oxidative stress and its connection with different signaling pathways are complicated; therefore, the systemic summary is essential. Herein, an effort has been made to decipher the interplay among heavy metals/metalloids (Arsenic, Chromium, Cadmium, and Lead) exposures, oxidative stress, and signal transduction, which are essential to mount the cellular and organismal response. The signaling pathways involved in this interplay include NF-κB, NRF2, JAK-STAT, JNK, FOXO, and HIF.

A bird's eye view of the advanced approaches and strategies for overshadowing triple negative breast cancer

Triple negative breast cancer (TNBC) is one of the most aggressive form of breast cancer. It is characterized by the absence of estrogen, progesterone and human epidermal growth factor receptors. The main issue with TNBC is that it exhibits poor prognosis, high risk of relapse, short progression-free survival and low overall survival in patients. This is because the conventional therapy used for managing TNBC has issues pertaining to poor bioavailability, lower cellular uptake, increased off-target effects and development of resistance. To overcome such pitfalls, several other approaches are explored. In this context, the present manuscript showcases three of the most widely used approaches which are (i) nanotechnology-based approach; (ii) gene therapy approach and (iii) Phytochemical-based approach. The ultimate focus is to present and explain the insightful reports based on these approaches. Further, the review also expounds on the identified molecular targets and novel targeting ligands which are explored for managing TNBC effectively. Thus, in a nutshell, the review tries to highlight these existing treatment approaches which might inspire for future development of novel therapies with a potential of overshadowing TNBC.

Realgar Nanoparticles Inhibit Migration, Invasion and Metastasis in a Mouse Model of Breast Cancer by Suppressing Matrix Metalloproteinases and Angiogenesis

BACKGROUND

Realgar, a traditional Chinese medicine, has shown antitumor efficacy in several tumor types. We previously showed that realgar nanoparticles (nano-realgar) had significant antileukemia, anti-lung cancer and anti-liver cancer effects. In addition, the anti-tumor effects of nanorealgar were significantly better than those of ordinary realgar.

OBJECTIVE

To explore the inhibitory effects and molecular mechanisms of nano-realgar on the migration, invasion and metastasis of mouse breast cancer cells.

METHODS

Wound-healing migration assays and Transwell invasion assays were carried out to determine the effects of nano-realgar on breast cancer cell (4T1) migration and invasion. The expression levels of matrix metalloproteinase (MMP)-2 and -9 were measured by Western blot. A murine breast cancer metastasis model was established, administered nano-realgar for 32 days and monitored for tumor growth and metastasis by an in vivo optical imaging system. Finally, living imaging and hematoxylin and eosin (HE) staining were used to measure the morphology and pathology of lung and liver cancer cell metastases, respectively. Angiogenesis was assessed by CD34 immunohistochemistry.

RESULTS

Nano-realgar significantly inhibited the migration and invasion of breast cancer 4T1 cells and the expression of MMP-2 and -9. Meanwhile, nano-realgar effectively suppressed the abilities of tumor growth, metastasis and angiogenesis in the murine breast cancer metastasis model in a time- and dosedependent manner.

CONCLUSION

Nano-realgar significantly inhibited migration and invasion of mouse breast cancer cells in vitro as well as pulmonary and hepatic metastasis in vivo, which may be closely correlated with the downexpression of MMP-2 and -9 and suppression of tumor neovascularization.

NLRP3 Inflammasome From Bench to Bedside: New Perspectives for Triple Negative Breast Cancer

The tumor microenvironment (TME) is crucial in cancer onset, progression and response to treatment. It is characterized by an intricate interaction of immune cells and cytokines involved in tumor development. Among these, inflammasomes are oligomeric molecular platforms and play a key role in inflammatory response and immunity. Inflammasome activation is initiated upon triggering of pattern recognition receptors (Toll-like receptors, NOD-like receptors, and Absent in melanoma like receptors), on the surface of immune cells with the recruitment of caspase-1 by an adaptor apoptosis-associated speck-like protein. This structure leads to the activation of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18 and participates in different biological processes exerting its effects. To date, the Nod-Like Receptor Protein 3 (NLRP3) inflammasome has been well studied and its involvement has been established in different cancer diseases. In this review, we discuss the structure, biology and mechanisms of inflammasomes with a special focus on the specific role of NLRP3 in breast cancer (BC) and in the sub-group of triple negative BC. The NLRP3 inflammasome and its down-stream pathways could be considered novel potential tumor biomarkers and could open new frontiers in BC treatment.

As4S4 Exhibits Good Killing Effect on Multiple Myeloma Cells Via Repressing SOCS1 Methylation-Mediated JAK2/STAT3 Signaling Pathway

Objective:

This study aimed to investigate the effect of tetra-arsenic tetra-sulfide on treating multiple myeloma and its potential regulation on suppressor of cytokine signaling 1 methylation-mediated Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway.

Methods:

Tetra-arsenic tetra-sulfide with different concentrations were used to treat U266 cells, and cell viability was measured at 12, 24, and 48 hours with 0 μM tetra-arsenic tetra-sulfide treatment as control by Cell Counting Kit-8 assay. Suppressor of cytokine signaling 1 methylation and expression were determined by methylation-specific polymerase chain reaction, quantitative polymerase chain reaction, and Western blot, respectively, in U266 cells and normal plasma cells and in U266 cells treated by tetra-arsenic tetra-sulfide. Then, rescue experiments were performed by transfecting suppressor of cytokine signaling 1 small interfering RNA into tetra-arsenic tetra-sulfide-treated U266 cells. Besides, phosphor–Janus kinase 2, Janus kinase 2, phospho–signal transducer and activator of transcription 3, and signal transducer and activator of transcription 3 expressions were determined by Western blot.

Results:

Tetra-arsenic tetra-sulfide inhibited U266 cell viability efficiently in a dose- and time-dependent manner. Suppressor of cytokine signaling 1 methylation was higher while suppressor of cytokine signaling 1 expression was lower in U266 cells compared to normal plasma cells; when treated by tetra-arsenic tetra-sulfide, suppressor of cytokine signaling 1 methylation was decreased while suppressor of cytokine signaling 1 expression was increased in U266 cells, along with the reduced phospho–Janus kinase 2 and phospho–signal transducer and activator of transcription 3 expressions. Then, suppressor of cytokine signaling 1 small interfering RNA enhanced the cell viability and phospho–Janus kinase 2 as well as phospho–signal transducer and activator of transcription 3 expressions in both tetra-arsenic tetra-sulfide treatment-free and tetra-arsenic tetra-sulfide-treated U266 cells.

Conclusion:

Tetra-arsenic tetra-sulfide exhibits good killing effect on multiple myeloma cells via repressing suppressor of cytokine signaling 1 methylation and downstream Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway, which might serve as a potential treatment option for multiple myeloma.