Combined effects of avasimibe immunotherapy, doxorubicin chemotherapy, and metal-organic frameworks nanoparticles on breast cancer

A polylysine/hyaluronan-based core-shell nanoparticle triggers drug delivery by ATP/hyaluronidase dual stimuli for inducing apoptosis of breast cancer cells

The limitations of self-assembled polymeric nanoparticles for cancer therapy, including instability in the bloodstream, non-specific targeting of cancer cells, and unregulated intracellular drug delivery, were effectively addressed by the development of core-shell SNX@PLL-FPBA/mHA NPs. The core was SNX@PLL-FPBA NPs prepared from polylysine conjugated 3-fluoro-4-carboxyphenylboronic acid (PLL-FPBA) self-assembly and SNX encapsulation, while the shell was methacrylate-modified hyaluronic acid (mHA) adhering to the core by electrostatic interactions and subsequently stabilized by photo-crosslinking, without the use of any organic solvent. SNX@PLL-FPBA/mHA NPs exhibited good stability in varying ionic strengths (0-0.30 M NaCl), pH levels (6.8 and 7.4), and plasma environments mimicking the blood, ensuring their efficacy in systemic circulation. The drug delivery from the nanoparticles was highly sensitive to ATP/Hyals stimuli (82 % within 48 h), closely mimicking the intracellular environment of breast cancer cells. The nanoparticles demonstrated good hemocompatibility and non-toxicity towards human skin fibroblasts. Efficient internalization of SNX@PLL-FPBA/mHA NPs by MCF-7 and MDA-MB-231 breast cancer cells was observed by CLSM and flow cytometry. The intracellular ATP/Hyals stimuli triggered the rapid drug delivery and induced cellular apoptosis. Thus, SNX@PLL-FPBA/mHA NPs were a promising drug nanocarrier for breast cancer therapy, offering improved stability, targeted delivery, and controlled drug release to enhance treatment outcomes.

Biochemical hallmarks-targeting antineoplastic nanotherapeutics

Tumor microenvironments (TMEs) have received increasing attention in recent years as they play pivotal roles in tumorigenesis, progression, metastases, and resistance to the traditional modalities of cancer therapy like chemotherapy. With the rapid development of nanotechnology, effective antineoplastic nanotherapeutics targeting the aberrant hallmarks of TMEs have been proposed. The appropriate design and fabrication endow nanomedicines with the abilities for active targeting, TMEs-responsiveness, and optimization of physicochemical properties of tumors, thereby overcoming transport barriers and significantly improving antineoplastic therapeutic benefits. This review begins with the origins and characteristics of TMEs and discusses the latest strategies for modulating the TMEs by focusing on the regulation of biochemical microenvironments, such as tumor acidosis, hypoxia, and dysregulated metabolism. Finally, this review summarizes the challenges in the development of smart anti-cancer nanotherapeutics for TME modulation and examines the promising strategies for combination therapies with traditional treatments for further clinical translation.

Targeting ACAT1 in cancer: from threat to treatment

Altered cholesterol metabolism has been identified as a critical feature of cancers. Cholesterol functions as the main component of cell membrane, cholesterol and is required for sustaining membrane integrity and mediating signaling transduction for cell survival. The intracellular level of cholesterol is dynamically regulated. Excessive cholesterol could be converted to less toxic cholesteryl esters by acyl-coenzyme A:cholesterol acyltransferases (ACATs). While ACAT2 has limited value in cancers, ACAT1 has been found to be widely participated in tumor initiation and progression. Moreover, due to the important role of cholesterol metabolism in immune function, ACAT1 is also essential for regulating anti-tumor immunity. ACAT1 inhibition may be exploited as a potential strategy to enhance the anti-tumor immunity and eliminate tumors. Herein, a comprehensive understanding of the role of ACAT1 in tumor development and anti-tumor immunity may provide new insights for anti-tumor strategies.

Lipid metabolic reprogramming in tumor microenvironment: from mechanisms to therapeutics

Lipid metabolic reprogramming is an emerging hallmark of cancer. In order to sustain uncontrolled proliferation and survive in unfavorable environments that lack oxygen and nutrients, tumor cells undergo metabolic transformations to exploit various ways of acquiring lipid and increasing lipid oxidation. In addition, stromal cells and immune cells in the tumor microenvironment also undergo lipid metabolic reprogramming, which further affects tumor functional phenotypes and immune responses. Given that lipid metabolism plays a critical role in supporting cancer progression and remodeling the tumor microenvironment, targeting the lipid metabolism pathway could provide a novel approach to cancer treatment. This review seeks to: (1) clarify the overall landscape and mechanisms of lipid metabolic reprogramming in cancer, (2) summarize the lipid metabolic landscapes within stromal cells and immune cells in the tumor microenvironment, and clarify their roles in tumor progression, and (3) summarize potential therapeutic targets for lipid metabolism, and highlight the potential for combining such approaches with other anti-tumor therapies to provide new therapeutic opportunities for cancer patients.

Functional significance of cholesterol metabolism in cancer: from threat to treatment

Cholesterol is an essential structural component of membranes that contributes to membrane integrity and fluidity. Cholesterol homeostasis plays a critical role in the maintenance of cellular activities. Recently, increasing evidence has indicated that cholesterol is a major determinant by modulating cell signaling events governing the hallmarks of cancer. Numerous studies have shown the functional significance of cholesterol metabolism in tumorigenesis, cancer progression and metastasis through its regulatory effects on the immune response, ferroptosis, autophagy, cell stemness, and the DNA damage response. Here, we summarize recent literature describing cholesterol metabolism in cancer cells, including the cholesterol metabolism pathways and the mutual regulatory mechanisms involved in cancer progression and cholesterol metabolism. We also discuss various drugs targeting cholesterol metabolism to suggest new strategies for cancer treatment.

Metal-organic coordination polymers for delivery of immunomodulatory agents, and infectious disease and cancer vaccines

Metal-organic coordination polymers (CPs) are a broad class of materials that include metal-organic frameworks (MOFs). CPs are highly ordered crystalline materials that are composed of metal ions (or metal ion clusters) and multidentate organic ligands that serve as linkers. One-, two-, and three-dimensional CPs can be formed, with 2D and 3D structures referred to as MOFs. CPs have gained a lot of attention due to attractive structural features like structure versatility and tunability, and well-defined pores that enable the encapsulation of cargo. Further, CPs show a lot of promise for drug delivery applications, but only a very limited number of CPs are currently being evaluated in clinical trials. In this review, we outlined features that are desired for CP-based drug delivery platform, and briefly described most relevant characterization techniques. We highlighted some of the recent efforts directed toward developing CP-based drug delivery platforms with the emphasis on vaccines against cancer, infectious diseases, and viruses. We hope this review will be a helpful guide for those interested in the design and evaluation of CP-based immunological drug delivery platforms. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Identification of co-regulated genes associated with doxorubicin resistance in the MCF-7/ADR cancer cell line

Introduction

The molecular mechanism of chemotherapy resistance in breast cancer is not well understood. The identification of genes associated with chemoresistance is critical for a better understanding of the molecular processes driving resistance.

Methods

This study used a co-expression network analysis of Adriamycin (or doxorubicin)-resistant MCF-7 (MCF-7/ADR) and its parent MCF-7 cell lines to explore the mechanisms of drug resistance in breast cancer. Genes associated with doxorubicin resistance were extracted from two microarray datasets (GSE24460 and GSE76540) obtained from the Gene Expression Omnibus (GEO) database using the GEO2R web tool. The candidate differentially expressed genes (DEGs) with the highest degree and/or betweenness in the co-expression network were selected for further analysis. The expression of major DEGs was validated experimentally using qRT-PCR.

Results

We identified twelve DEGs in MCF-7/ADR compared with its parent MCF-7 cell line, including 10 upregulated and 2 downregulated DEGs. Functional enrichment suggests a key role for RNA binding by IGF2BPs and epithelial-to-mesenchymal transition pathways in drug resistance in breast cancer.

Discussion

Our findings suggested that MMP1, VIM, CNN3, LDHB, NEFH, PLS3, AKAP12, TCEAL2, and ABCB1 genes play an important role in doxorubicin resistance and could be targeted for developing novel therapies by chemical synthesis approaches.

Current Principles, Challenges, and New Metrics in pH-Responsive Drug Delivery Systems for Systemic Cancer Therapy

The paradigm of drug delivery via particulate formulations is one of the leading ideas that enable overcoming limitations of traditional chemotherapeutic agents. The trend toward more complex multifunctional drug carriers is well-traced in the literature. Nowadays, the prospectiveness of stimuli-responsive systems capable of controlled cargo release in the lesion nidus is widely accepted. Both endogenous and exogenous stimuli are employed for this purpose; however, endogenous pH is the most common trigger. Unfortunately, scientists encounter multiple challenges on the way to the implementation of this idea related to the vehicles' accumulation in off-target tissues, their immunogenicity, the complexity of drug delivery to intracellular targets, and finally, the difficulties in the fabrication of carriers matching all imposed requirements. Here, we discuss fundamental strategies for pH-responsive drug delivery, as well as limitations related to such carriers' application, and reveal the main problems, weaknesses, and reasons for poor clinical results. Moreover, we attempted to formulate the profiles of an "ideal" drug carrier in the frame of different strategies drawing on the example of metal-comprising materials and considered recently published studies through the lens of these profiles. We believe that this approach will facilitate the formulation of the main challenges facing researchers and the identification of the most promising trends in technology development.

Metallic Nanoparticles: Their Potential Role in Breast Cancer Immunotherapy via Trained Immunity Provocation

Owing to drawbacks in the current common cancer therapies including surgery, chemotherapy and radiotherapy, the development of more reliable, low toxic, cost-effective and specific approaches such as immunotherapy is crucial. Breast cancer is among the leading causes of morbidity and mortality with a developed anticancer resistance. Accordingly, we attempted to uncover the efficacy of metallic nanoparticles (MNPs)-based breast cancer immunotherapy emphasizing trained immunity provocation or innate immunity adaptation. Due to the immunosuppressive nature of the tumor microenvironment (TME) and the poor infiltration of immune cells, the potentiation of an immune response or direct combat is a goal employing NPs as a burgeoning field. During the recent decades, the adaptation of the innate immunity responses against infectious diseases and cancer has been recognized. Although the data is in a scarcity with regard to a trained immunity function in breast cancer cells' elimination, this study introduced the potential of this arm of immunity adaptation using MNPs.

Hybrid Nanomaterials for Cancer Immunotherapy

Nano-immunotherapy has been recognized as a highly promising strategy for cancer treatment in recent decades, which combines nanotechnology and immunotherapy to combat against tumors. Hybrid nanomaterials consisting of at least two constituents with distinct compositions and properties, usually organic and inorganic, have been engineered with integrated functions and enormous potential in boosting cancer immunotherapy. This review provides a summary of hybrid nanomaterials reported for cancer immunotherapy, including nanoscale metal-organic frameworks, metal-phenolic networks, mesoporous organosilica nanoparticles, metallofullerene nanomaterials, polymer-lipid, and biomacromolecule-based hybrid nanomaterials. The combination of immunotherapy with chemotherapy, chemodynamic therapy, radiotherapy, radiodynamic therapy, photothermal therapy, photodynamic therapy, and sonodynamic therapy based on hybrid nanomaterials is also discussed. Finally, the current challenges and the prospects for designing hybrid nanomaterials and their application in cancer immunotherapy are outlined.

Nanomaterials in anticancer applications and their mechanism of action - A review

The current challenges in cancer treatment using conventional therapies have made the emergence of nanotechnology with more advancements. The exponential growth of nanoscience has drawn to develop nanomaterials (NMs) with therapeutic activities. NMs have enormous potential in cancer treatment by altering the drug toxicity profile. Nanoparticles (NPs) with enhanced surface characteristics can diffuse more easily inside tumor cells, thus delivering an optimal concentration of drugs at tumor site while reducing the toxicity. Cancer cells can be targeted with greater affinity by utilizing NMs with tumor specific constituents. Furthermore, it bypasses the bottlenecks of indiscriminate biodistribution of the antitumor agent and high administration dosage. Here, we focus on the recent advances on the use of various nanomaterials for cancer treatment, including targeting cancer cell surfaces, tumor microenvironment (TME), organelles, and their mechanism of action. The paradigm shift in cancer management is achieved through the implementation of anticancer drug delivery using nano routes.

Targeting Sterol O-Acyltransferase/Acyl-CoA:Cholesterol Acyltransferase (ACAT): A Perspective on Small-Molecule Inhibitors and Their Therapeutic Potential

Sterol O-acyltransferase (SOAT) is a membrane-bound enzyme that aids the esterification of cholesterol and fatty acids to cholesterol esters. SOAT has been studied extensively as a potential drug target, since its inhibition can serve as an alternative to statin therapy. Two SOAT isozymes that have discrete functions in the human body, namely, SOAT1 and SOAT2, have been characterized. Over three decades of research has focused on candidate SOAT1 inhibitors with unsatisfactory results in clinical trials. Recent research has focused on targeting SOAT2 selectively. In this perspective, we summarize the literature covering various SOAT inhibitory agents and discuss the design, structural requirements, and mode of action of SOAT inhibitors.

Nanotherapeutics for immune network modulation in tumor microenvironments

Immunotherapy has shown promise in cancer treatment, and is thus drawing increasing interest in this field. While the standard chemotherapy- and/or radiotherapy-based cancer treatments aim to directly kill cancer cells, immunotherapy uses host immune cell surveillance to fight cancer. In the tumor environment, there is a close relationship between tumor cells and the adjacent immune cells, which are largely suppressed by cancer-related regulation of immune checkpoints, immune-suppressive cytokines, and metabolic factors. The immune modulators currently approved for cancer treatment remain limited by issues with dose tolerance and insufficient efficacy. Researchers have developed and tested various nano-delivery systems with the goal of improving the treatment outcome of these drugs. By encapsulating immune modulators in particles and directing their tissue accumulation, some such systems have decreased immune-related toxicity while sharpening the antitumor response. Surface-ligand modification of nanoparticles has allowed drugs to be delivered to specific immune cells types. Researchers have also studied strategies for depleting or reprogramming the immune-suppressive cells to recover the immune environment. Combining a nanomaterial with an external stimulus has been used to induce immunogenic cell death; this favors the inflammatory environment found in tumor tissues to promote antitumor immunity. The present review covers the most recent strategies aimed at modulating the tumor immune environment, and discusses the challenges and future perspectives in developing nanoparticles for cancer immunotherapy.

Emerging advances in nanomedicine for breast cancer immunotherapy: opportunities and challenges

Breast cancer is one of the most common causes of cancer-related morbidity and mortality in women worldwide. Early diagnosis and an appropriate therapeutic approach for all cancers are climacterics for a favorable prognosis. Targeting the immune system in breast cancer is already a clinical reality with notable successes, specifically with checkpoint blockade antibodies and chimeric antigen receptor T-cell therapy. However, there have been inevitable setbacks in the clinical application of cancer immunotherapy, including inadequate immune responses due to insufficient delivery of immunostimulants to immune cells and uncontrolled immune system modulation. Rapid advancements and new evidence have suggested that nanomedicine-based immunotherapy may be a viable option for treating breast cancer.

Cholesterol and Its Derivatives: Multifaceted Players in Breast Cancer Progression

Cholesterol is an essential lipid primarily synthesized in the liver through the mevalonate pathway. Besides being a precursor of steroid hormones, bile acid, and vitamin D, it is an essential structural component of cell membranes, is enriched in membrane lipid rafts, and plays a key role in intracellular signal transduction. The lipid homeostasis is finely regulated end appears to be impaired in several types of tumors, including breast cancer. In this review, we will analyse the multifaceted roles of cholesterol and its derivatives in breast cancer progression. As an example of the bivalent role of cholesterol in the cell membrane of cancer cells, on the one hand, it reduces membrane fluidity, which has been associated with a more aggressive tumor phenotype in terms of cell motility and migration, leading to metastasis formation. On the other hand, it makes the membrane less permeable to small water-soluble molecules that would otherwise freely cross, resulting in a loss of chemotherapeutics permeability. Regarding cholesterol derivatives, a lower vitamin D is associated with an increased risk of breast cancer, while steroid hormones, coupled with the overexpression of their receptors, play a crucial role in breast cancer progression. Despite the role of cholesterol and derivatives molecules in breast cancer development is still controversial, the use of cholesterol targeting drugs like statins and zoledronic acid appears as a challenging promising tool for breast cancer treatment.

Characteristics of Graphene Oxide for Gene Transfection and Controlled Release in Breast Cancer Cells

Functionalized graphene oxide (GO) nanoparticles are being increasingly employed for designing modern drug delivery systems because of their high degree of functionalization, high surface area with exceptional loading capacity, and tunable dimensions. With intelligent controlled release and gene silencing capability, GO is an effective nanocarrier that permits the targeted delivery of small drug molecules, antibodies, nucleic acids, and peptides to the liquid or solid tumor sites. However, the toxicity and biocompatibility of GO-based formulations should be evaluated, as these nanomaterials may introduce aggregations or may accumulate in normal tissues while targeting tumors or malignant cells. These side effects may potentially be impacted by the dosage, exposure time, flake size, shape, functional groups, and surface charges. In this review, the strategies to deliver the nucleic acid via the functionalization of GO flakes are summarized to describe the specific targeting of liquid and solid breast tumors. In addition, we describe the current approaches aimed at optimizing the controlled release towards a reduction in GO accumulation in non-specific tissues in terms of the cytotoxicity while maximizing the drug efficacy. Finally, the challenges and future research perspectives are briefly discussed.

The Impacts of Prepared Plasma-Activated Medium (PAM) Combined with Doxorubicin on the Viability of MCF-7 Breast Cancer Cells: A New Cancer Treatment Strategy

BACKGROUND

For many years, the chemotherapeutic agent doxorubicin (DOX) has been used to treat various cancers; however, DOX initiates several critical adverse effects. Many studies have reported that non-thermal atmospheric pressure plasma can provide novel, but challenging, treatment strategies for cancer patients. To date, tissues and cells have been treated with plasma-activated medium (PAM) as a practical therapy. Consequently, due to the harmful adverse effects of DOX, we were motivated to elucidate the impact of PAM in the presence of DOX on MCF-7 cell proliferation.

METHODS

MTT assay, N-acetyl-L-cysteine (NAC) assay, and flow cytometry analysis were utilized in this research.

RESULTS

The results demonstrated that 0.45 µM DOX combined with 3-min PAM significantly induced apoptosis (p< 0.01) through intracellular ROS generation in MCF-7 when compared with 0.45 µM DOX alone or 3-min PAM alone. In contrast, after treatment with 0.45 µM DOX plus 4-min PAM, cell necrosis was increased. Hence, DOX combined with 4-min PAM has cytotoxic effects with different mechanisms than 4-min PAM alone, in which the number of apoptotic cells increases.

CONCLUSION

Although further investigations are crucial, low doses of DOX plus 3-min PAM could be a promising strategy for cancer therapy. The findings from this research may offer advantageous and innovative clinical strategies for cancer therapy using PAM.

The Application of Nanoparticles in Diagnosis and Treatment of Kidney Diseases

Nanomedicine is currently showing great promise for new methods of diagnosing and treating many diseases, particularly in kidney disease and transplantation. The unique properties of nanoparticles arise from the diversity of size effects, used to design targeted nanoparticles for specific cells or tissues, taking renal clearance and tubular secretion mechanisms into account. The design of surface particles on nanoparticles offers a wide range of possibilities, among which antibodies play an important role. Nanoparticles find applications in encapsulated drug delivery systems containing immunosuppressants and other drugs, in imaging, gene therapies and many other branches of medicine. They have the potential to revolutionize kidney transplantation by reducing and preventing ischemia-reperfusion injury, more efficiently delivering drugs to the graft site while avoiding systemic effects, accurately localizing and visualising the diseased site and enabling continuous monitoring of graft function. So far, there are known nanoparticles with no toxic effects on human tissue, although further studies are still needed to confirm their safety.

Lipid metabolism in cancer progression and therapeutic strategies

Dysregulated lipid metabolism represents an important metabolic alteration in cancer. Fatty acids, cholesterol, and phospholipid are the three most prevalent lipids that act as energy producers, signaling molecules, and source material for the biogenesis of cell membranes. The enhanced synthesis, storage, and uptake of lipids contribute to cancer progression. The rewiring of lipid metabolism in cancer has been linked to the activation of oncogenic signaling pathways and cross talk with the tumor microenvironment. The resulting activity favors the survival and proliferation of tumor cells in the harsh conditions within the tumor. Lipid metabolism also plays a vital role in tumor immunogenicity via effects on the function of the noncancer cells within the tumor microenvironment, especially immune‐associated cells. Targeting altered lipid metabolism pathways has shown potential as a promising anticancer therapy. Here, we review recent evidence implicating the contribution of lipid metabolic reprogramming in cancer to cancer progression, and discuss the molecular mechanisms underlying lipid metabolism rewiring in cancer, and potential therapeutic strategies directed toward lipid metabolism in cancer. This review sheds new light to fully understanding of the role of lipid metabolic reprogramming in the context of cancer and provides valuable clues on therapeutic strategies targeting lipid metabolism in cancer.

Combining Nanotechnology and Gas Plasma as an Emerging Platform for Cancer Therapy: Mechanism and Therapeutic Implication

Nanomedicine and plasma medicine are innovative and multidisciplinary research fields aiming to employ nanotechnology and gas plasma to improve health-related treatments. Especially cancer treatment has been in the focus of both approaches because clinical response rates with traditional methods that remain improvable for many types of tumor entities. Here, we discuss the recent progress of nanotechnology and gas plasma independently as well as in the concomitant modality of nanoplasma as multimodal platforms with unique capabilities for addressing various therapeutic issues in oncological research. The main features, delivery vehicles, and nexus between reactivity and therapeutic outcomes of nanoparticles and the processes, efficacy, and mechanisms of gas plasma are examined. Especially that the unique feature of gas plasma technology, the local and temporally controlled deposition of a plethora of reactive oxygen, and nitrogen species released simultaneously might be a suitable additive treatment to the use of systemic nanotechnology therapy approaches. Finally, we focus on the convergence of plasma and nanotechnology to provide a suitable strategy that may lead to the required therapeutic outcomes.

Pharmacologic and genetic inhibition of cholesterol esterification enzymes reduces tumour burden: A systematic review and meta-analysis of preclinical models

Cholesterol esterification proteins Sterol-O acyltransferases (SOAT) 1 and 2 are emerging prognostic markers in many cancers. These enzymes utilise fatty acids conjugated to coenzyme A to esterify cholesterol. Cholesterol esterification is tightly regulated and enables formation of lipid droplets that act as storage organelles for lipid soluble vitamins and minerals, and as cholesterol reservoirs. In cancer, this provides rapid access to cholesterol to maintain continual synthesis of the plasma membrane. In this systematic review and meta-analysis, we summarise the current depth of understanding of the role of this metabolic pathway in pan-cancer development. A systematic search of PubMed, Scopus, Web of Science, and Cochrane Library for preclinical studies identified eight studies where cholesteryl ester concentrations were compared between tumour and adjacent-normal tissue, and 24 studies where cholesterol esterification was blocked by pharmacological or genetic approaches. Tumour tissue had a significantly greater concentration of cholesteryl esters than non-tumour tissue (p < 0.0001). Pharmacological or genetic inhibition of SOAT was associated with significantly smaller tumours of all types (p ≤ 0.002). SOAT inhibition increased tumour apoptosis (p = 0.007), CD8 + lymphocyte infiltration and cytotoxicity (p ≤ 0.05), and reduced proliferation (p = 0.0003) and metastasis (p < 0.0001). Significant risk of publication bias was found and may have contributed to a 32% overestimation of the meta-analysed effect size. Avasimibe, the most frequently used SOAT inhibitor, was effective at doses equivalent to those previously reported to be safe and tolerable in humans. This work indicates that SOAT inhibition should be explored in clinical trials as an adjunct to existing anti-neoplastic agents.

Cholesteryl Ester Promotes Mammary Tumor Growth in MMTV-PyMT Mice and Activates Akt-mTOR Pathway in Tumor Cells

The association between intratumoral cholesteryl ester (CE) and tumor progression has been reported previously. The objective of our study was to investigate a causal effect of CE on mammary tumor progression. Using MMTV-PyMT (MMTV-polyoma virus middle T) transgenic mice and breast tumor cell MCF-7, we show that both exogenous and endogenous CE can increase mammary tumor growth, that CE upregulates the AKT/mTOR pathway, and that CE synthesis blockade suppresses this signaling pathway. Our data suggest that SOAT1, a sterol O-acyltransferase, may be a potential target for the treatment of breast cancer.

The Ubiquitin Proteasome System and Skin Fibrosis

The ubiquitin proteasome system (UPS) is a highly conserved way to regulate protein turnover in cells. The UPS hydrolyzes and destroys variant or misfolded proteins and finely regulates proteins involved in differentiation, apoptosis, and other biological processes. This system is a key regulatory factor in the proliferation, differentiation, and collagen secretion of skin fibroblasts. E3 ubiquitin protein ligases Parkin and NEDD4 regulate multiple signaling pathways in keloid. Tumor necrosis factor (TNF) receptor-associated factor 4 (TRAF4) binding with deubiquitinase USP10 can induce p53 destabilization and promote keloid-derived fibroblast proliferation. The UPS participates in the occurrence and development of hypertrophic scars by regulating the transforming growth factor (TGF)-β/Smad signaling pathway. An initial study suggests that TNFα-induced protein 3 (TNFAIP3) polymorphisms may be significantly associated with scleroderma susceptibility in individuals of Caucasian descent. Sumoylation and multiple ubiquitin ligases, including Smurfs, UFD2, and KLHL42, play vital roles in scleroderma by targeting the TGF-β/Smad signaling pathway. In the future, drugs targeting E3 ligases and deubiquitinating enzymes have great potential for the treatment of skin fibrosis.

Emerging nanomedicines for effective breast cancer immunotherapy

Breast cancer continues to be the most frequently diagnosed malignancy among women, putting their life in jeopardy. Cancer immunotherapy is a novel approach with the ability to boost the host immune system to recognize and eradicate cancer cells with high selectivity. As a promising treatment, immunotherapy can not only eliminate the primary tumors, but also be proven to be effective in impeding metastasis and recurrence. However, the clinical application of cancer immunotherapy has faced some limitations including generating weak immune responses due to inadequate delivery of immunostimulants to the immune cells as well as uncontrolled modulation of immune system, which can give rise to autoimmunity and nonspecific inflammation. Growing evidence has suggested that nanotechnology may meet the needs of current cancer immunotherapy. Advanced biomaterials such as nanoparticles afford a unique opportunity to maximize the efficiency of immunotherapy and significantly diminish their toxic side-effects. Here we discuss recent advancements that have been made in nanoparticle-involving breast cancer immunotherapy, varying from direct activation of immune systems through the delivery of tumor antigens and adjuvants to immune cells to altering immunosuppression of tumor environment and combination with other conventional therapies.

Bioengineering of nano metal-organic frameworks for cancer immunotherapy

Immunotherapy techniques, such as immune checkpoint inhibitors, chimeric antigen receptor (CAR) T cell therapies and cancer vaccines, have been burgeoning with great success, particularly for specific cancer types. However, side effects with fatal risks, dysfunction in tumor microenvironment and low immune response rates remain the bottlenecks in immunotherapy. Nano metal-organic frameworks (nMOFs), with an accurate structure and a narrow size distribution, are emerging as a solution to these problems. In addition to their function of temporospatial delivery, a large library of their compositions, together with flexibility in chemical interaction and inherent immune efficacy, offers opportunities for various designs of nMOFs for immunotherapy. In this review, we overview state-of-the-art research on nMOFs-based immunotherapies as well as their combination with other therapies. We demonstrate that nMOFs are predominantly customized for vaccine delivery or tumor-microenvironment modulation. Finally, a prospect of nMOFs in cancer immunotherapy will be discussed.

Identifying Differing Intracellular Cargo Release Mechanisms by Monitoring In Vitro Drug Delivery from MOFs in Real Time

Metal-organic frameworks (MOFs) have been proposed as biocompatible candidates for the targeted intracellular delivery of chemotherapeutic payloads, but the site of drug loading and subsequent effect on intracellular release is often overlooked. Here, we analyze doxorubicin delivery to cancer cells by MIL-101(Cr) and UiO-66 in real time. Having experimentally and computationally verified that doxorubicin is pore loaded in MIL-101(Cr) and surface loaded on UiO-66, different time-dependent cytotoxicity profiles are observed by real-time cell analysis and confocal microscopy. The attenuated release of aggregated doxorubicin from the surface of Dox@UiO-66 results in a 12 to 16 h induction of cytotoxicity, while rapid release of pore-dispersed doxorubicin from Dox@MIL-101(Cr) leads to significantly higher intranuclear localization and rapid cell death. In verifying real-time cell analysis as a versatile tool to assess biocompatibility and drug delivery, we show that the localization of drugs in (or on) MOF nanoparticles controls delivery profiles and is key to understanding in vitro modes of action.

Recent Progress of Nanocarrier-Based Therapy for Solid Malignancies

Conventional chemotherapy is still an important option of cancer treatment, but it has poor cell selectivity, severe side effects, and drug resistance. Utilizing nanoparticles (NPs) to improve the therapeutic effect of chemotherapeutic drugs has been highlighted in recent years. Nanotechnology dramatically changed the face of oncology by high loading capacity, less toxicity, targeted delivery of drugs, increased uptake to target sites, and optimized pharmacokinetic patterns of traditional drugs. At present, research is being envisaged in the field of novel nano-pharmaceutical design, such as liposome, polymer NPs, bio-NPs, and inorganic NPs, so as to make chemotherapy effective and long-lasting. Till now, a number of studies have been conducted using a wide range of nanocarriers for the treatment of solid tumors including lung, breast, pancreas, brain, and liver. To provide a reference for the further application of chemodrug-loaded nanoformulations, this review gives an overview of the recent development of nanocarriers, and the updated status of their use in the treatment of several solid tumors.

The Pivotal Role of the Dysregulation of Cholesterol Homeostasis in Cancer: Implications for Therapeutic Targets

Cholesterol plays an important role in cellular homeostasis by maintaining the rigidity of cell membranes, providing a medium for signaling transduction, and being converted into other vital macromolecules, such as sterol hormones and bile acids. Epidemiological studies have shown the correlation between cholesterol content and cancer incidence worldwide. Accumulating evidence has shown the emerging roles of the dysregulation of cholesterol metabolism in cancer development. More specifically, recent reports have shown the distinct role of cholesterol in the suppression of immune cells, regulation of cell survival, and modulation of cancer stem cells in cancer. Here, we provide a comprehensive review of the epidemiological analysis, functional roles, and mechanistic action of cholesterol homeostasis in regard to its contribution to cancer development. Based on the existing data, cholesterol homeostasis is identified to be a new key player in cancer pathogenesis. Lastly, we also discuss the therapeutic implications of natural compounds and cholesterol-lowering drugs in cancer prevention and treatment. In conclusion, intervention in cholesterol metabolism may offer a new therapeutic avenue for cancer treatment.

Cholesterol metabolism in cancer: mechanisms and therapeutic opportunities

Cholesterol metabolism produces essential membrane components as well as metabolites with a variety of biological functions. In the tumour microenvironment, cell-intrinsic and cell-extrinsic cues reprogram cholesterol metabolism and consequently promote tumourigenesis. Cholesterol-derived metabolites play complex roles in supporting cancer progression and suppressing immune responses. Preclinical and clinical studies have shown that manipulating cholesterol metabolism inhibits tumour growth, reshapes the immunological landscape and reinvigorates anti-tumour immunity. Here, we review cholesterol metabolism in cancer cells, its role in cancer progression and the mechanisms through which cholesterol metabolites affect immune cells in the tumour microenvironment. We also discuss therapeutic strategies aimed at interfering with cholesterol metabolism, and how the combination of such approaches with existing anti-cancer therapies can have synergistic effects, thus offering new therapeutic opportunities.