Sodium bicarbonate, an inorganic salt and a potential active agent for cancer therapy

Cationic liposomes as a drug-free system for efficient anticancer therapy by intracytoplasmic delivery of sodium bicarbonate

Developing the delivery systems with high therapeutic efficacy and low side effects is of great interest and significance for anticancer therapy. Compared to the high cost in synthesizing new chemotherapeutic drugs, exploring the anticancer potentials of existing chemicals is more convenient and efficient. Sodium bicarbonate (BC), a simple inorganic salt, has shown its tumor inhibition capacity via regulating the acidity of tumor microenvironment. However, the effects of intracytoplasmic BC on tumor growth and the potentials of BC to serve as an anticancer agent are still unknown. Herein, we developed a BC-loaded cationic liposome system (BC-CLP) to deliver BC into the cytosol of cancer cells. The in vitro studies showed that the BC-CLP containing 1% BC (w/v) had a size of 112.9 nm and a zeta potential of 19.1 mV, which reduced the viability of the model cancer cells (human oral squamous cell carcinoma HSC-3 cells) to 13.7%. In contrast, the neutral BC-LP caused less than 50% viability reduction. We further found that BC-CLP released BC directly into cytoplasm via membrane fusion pathway rather than endocytosis, leading to the remarkable increase of cytosolic pH, which may contribute to the anticancer effect of BC-CLP. Our findings indicate that BC-CLP is a potential system for high-efficiency cancer therapy without causing drug-related side effects or resistance.

Tumor microenvironment reprogramming by nanomedicine to enhance the effect of tumor immunotherapy

With the rapid development of the fields of tumor biology and immunology, tumor immunotherapy has been used in clinical practice and has demonstrated significant therapeutic potential, particularly for treating tumors that do not respond to standard treatment options. Despite its advances, immunotherapy still has limitations, such as poor clinical response rates and differences in individual patient responses, largely because tumor tissues have strong immunosuppressive microenvironments. Many tumors have a tumor microenvironment (TME) that is characterized by hypoxia, low pH, and substantial numbers of immunosuppressive cells, and these are the main factors limiting the efficacy of antitumor immunotherapy. The TME is crucial to the occurrence, growth, and metastasis of tumors. Therefore, numerous studies have been devoted to improving the effects of immunotherapy by remodeling the TME. Effective regulation of the TME and reversal of immunosuppressive conditions are effective strategies for improving tumor immunotherapy. The use of multidrug combinations to improve the TME is an efficient way to enhance antitumor immune efficacy. However, the inability to effectively target drugs decreases therapeutic effects and causes toxic side effects. Nanodrug delivery carriers have the advantageous ability to enhance drug bioavailability and improve drug targeting. Importantly, they can also regulate the TME and deliver large or small therapeutic molecules to decrease the inhibitory effect of the TME on immune cells. Therefore, nanomedicine has great potential for reprogramming immunosuppressive microenvironments and represents a new immunotherapeutic strategy. Therefore, this article reviews strategies for improving the TME and summarizes research on synergistic nanomedicine approaches that enhance the efficacy of tumor immunotherapy.

Dual source-powered multifunctional Pt/FePc@Mn-MOF spindle-like Janus nanomotors for active CT imaging-guided synergistic photothermal/chemodynamic therapy

Nanomaterials capable of dual therapeutic effects of chemodynamic therapy (CDT) and photothermal therapy (PTT) is an efficacious strategy in cancer treatment. It is still a challenge to achieve complete apoptosis of tumor tissue in CDT/PTT due to the poor permeability of nanomaterials in tumor tissue. Herein, we prepared a dual-source driven Pt/FePc@Mn-MOF spindle-like Janus nanomotor by a facile oriented connection growth method for computed tomography (CT) imaging-guided CDT and PTT. The high catalase (CAT)-like activity of nanomotors allows the generation of oxygen (O2) bubbles by catalyzing the decomposition of endogenous H2O2, which alleviates the hypoxic state of the tumor microenvironment (TME) and simultaneously drive nanomotors. Pt/FePc@Mn-MOF nanomotor with excellent photothermal conversion efficiency exhibited dual peroxidase (POD)-like and oxidase (OXD)-like activities, which can produce large amounts of ROS to obtain PTT enhanced CDT. Meanwhile, near-infrared light, as "optical brakes", can trigger Janus nanomotor to realize self-thermophoretic movement. Chemical/NIR-assisted autonomous propulsion can significantly improve the accumulation of Janus nanomotors in solid tumors and enhance their ability to penetrate tumor tissue, thus brings synergistic enhancement effect to PTT and CDT. Moreover, Mn-MOF in nanomotor can deplete the antioxidant GSH by redox reaction to release massive Mn2+, which introduce Mn2+-based CT imaging properties. This novel dual-source controlled Janus nanomotor offers great potential for multimodal therapeutic medical applications.

Advancements in pH-responsive nanocarriers: enhancing drug delivery for tumor therapy

INTRODUCTION

Tumors pose a significant global economic and health burden, with conventional cancer treatments lacking tumor specificity, leading to limited efficiency and undesirable side effects. Targeted tumor therapy is imminent. Tumor cells produce lactate and hydrogen ions (H+) by Warburg effect, forming an acidic tumor microenvironment (TME), which can be employed to design targeted tumor therapy. Recently, progress in nanotechnology has led to the development of pH-responsive nanocarriers, which have gathered significant attention. Under acidic tumor conditions, they exhibit targeted accumulation within tumor sites and controlled release profiles of therapeutic reagents, enabling precise tumor therapy.

AREAS COVERED

This review comprehensively summarize the principles underlying pH-responsive features, discussing various types of pH-responsive nanocarriers, their advantages, and limitations. Innovative therapeutic drugs are also examined, followed by an exploration of recent advancements in applying various pH-responsive nanocarriers as delivery systems for enhanced tumor therapy.

EXPERT OPINIONS

pH-responsive nanocarriers have garnered significant attention for their capability to achieve targeted accumulation of therapeutic agents at tumor sites and controlled drug delivery profiles, ultimately increasing the efficiency of tumor eradication. It is anticipated that the employment of pH-responsive nanocarriers will elevate the effectiveness and safety of tumor therapy, contributing to improved overall outcomes.

Tumor microenvironment-regulating nanomedicine design to fight multi-drug resistant tumors

The tumor microenvironment (TME) is a very cunning system that enables tumor cells to escape death post-traditional antitumor treatments through the comprehensive effect of different factors, thereby leading to drug resistance. Deep insights into TME characteristics and tumor resistance encourage the construction of nanomedicines that can remodel the TME against drug resistance. Tremendous interest in combining TME-regulation measurement with traditional tumor treatment to fight multidrug-resistant tumors has been inspired by the increasing understanding of the role of TME reconstruction in improving the antitumor efficiency of drug-resistant tumor therapy. This review focuses on the underlying relationships between specific TME characteristics (such as hypoxia, acidity, immunity, microorganisms, and metabolism) and drug resistance in tumor treatments. The exciting antitumor activities strengthened by TME regulation are also discussed in-depth, providing solutions from the perspective of nanomedicine design. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Warburg Effect Revisited: Embodiment of Classical Biochemistry and Organic Chemistry. Current State and Prospects

The Nobel Prize Winner (1931) Dr. Otto H. Warburg had established that the primary energy source of the cancer cell is aerobic glycolysis (the Warburg effect). He also postulated the hypothesis about "the prime cause of cancer", which is a matter of debate nowadays. Contrary to the hypothesis, his discovery was recognized entirely. However, the discovery had almost vanished in the heat of battle about the hypothesis. The prime cause of cancer is essential for the prevention and diagnosis, yet the effects that influence tumor growth are more important for cancer treatment. Due to the Warburg effect, a large amount of data has been accumulated on biochemical changes in the cell and the organism as a whole. Due to the Warburg effect, the recovery of normal biochemistry and oxygen respiration and the restoration of the work of mitochondria of cancer cells can inhibit tumor growth and lead to remission. Here, we review the current knowledge on the inhibition of abnormal glycolysis, neutralization of its consequences, and normalization of biochemical parameters, as well as recovery of oxygen respiration of a cancer cell and mitochondrial function from the point of view of classical biochemistry and organic chemistry.

Nanomaterials-mediated photodynamic therapy and its applications in treating oral diseases

Oral diseases, such as dental caries, periodontitis and oral cancer, have a very high morbidity over the world. Basically, many oral diseases are commonly related to bacterial infections or cell malignant proliferation, and usually located on the superficial positions. These features allow the convenient and efficient application of photodynamic therapy (PDT) for oral diseases, since PDT is ideally suitable for the diseases on superficial sites and has been widely used for antimicrobial and anticancer therapy. Photosensitizers (PSs) are an essential element in PDT, which induce the generation of a large number of reactive oxygen species (ROS) upon absorption of specific lights. Almost all the PSs are small molecules and commonly suffered from various problems in the PDT environment, such as low solubility and poor stability. Recently, reports on the nanomedicine-based PDT have been well documented. Various functionalized nanomaterials can serve either as the PSs carriers or the direct PSs, thus enhancing the PDT efficacy. Herein, we aim to provide a comprehensive understanding of the features of different oral diseases and discuss the potential applications of nanomedicine-based PDT in the treatment of some common oral diseases. Also, the concerns and possible solutions for nanomaterials-mediated PDT are discussed.

Dialysis as a Novel Adjuvant Treatment for Malignant Cancers

Simple Summary

There is a clear need for new cancer therapies as many cancers have a very short long-term survival rate. For most advanced cancers, therapy resistance limits the benefit of any single-agent chemotherapy, radiotherapy, or immunotherapy. Cancer cells show a greater dependence on glucose and glutamine as fuel than healthy cells do. In this article, we propose using 4- to 8-h dialysis treatments to change the blood composition, i.e., lowering glucose and glutamine levels, and elevating ketone levels—thereby disrupting major metabolic pathways important for cancer cell survival. The dialysis’ impact on cancer cells include not only metabolic effects, but also redox balance, immunological, and epigenetic effects. These pleiotropic effects could potentially enhance the effectiveness of traditional cancer treatments, such as radiotherapies, chemotherapies, and immunotherapies—resulting in improved outcomes and longer survival rates for cancer patients.

Abstract

Cancer metabolism is characterized by an increased utilization of fermentable fuels, such as glucose and glutamine, which support cancer cell survival by increasing resistance to both oxidative stress and the inherent immune system in humans. Dialysis has the power to shift the patient from a state dependent on glucose and glutamine to a ketogenic condition (KC) combined with low glutamine levels—thereby forcing ATP production through the Krebs cycle. By the force of dialysis, the cancer cells will be deprived of their preferred fermentable fuels, disrupting major metabolic pathways important for the ability of the cancer cells to survive. Dialysis has the potential to reduce glucose levels below physiological levels, concurrently increase blood ketone body levels and reduce glutamine levels, which may further reinforce the impact of the KC. Importantly, ketones also induce epigenetic changes imposed by histone deacetylates (HDAC) activity (Class I and Class IIa) known to play an important role in cancer metabolism. Thus, dialysis could be an impactful and safe adjuvant treatment, sensitizing cancer cells to traditional cancer treatments (TCTs), potentially making these significantly more efficient.

Umbilical cord mesenchymal stem cells and breast cancer: a good therapeutic candidate or not? A minireview

Breast cancer (BC), as the most common cancer among women, affects a great number of subjects around the world. This heterogenic disease is divided into several types and subtypes, and each subtype has various phenotypes and genotypes. Against BC, several options have been proposed, such as surgery, radiotherapy, and chemotherapeutic agents. However, these approaches may have detrimental effects on health and life quality of patients. Hence, harnessing a therapeutic tool with high effectiveness and low side effects is required. Recently, mesenchymal stem cells (MSCs) have created a new window to treat various disorders, like cancer, and among these, umbilical cord (UC)-derived MSCs have acquired much interest due to their advantages. Therefore, in this narrative review, the influences of UC-derived MSCs on BC were reviewed and summarized with a focus on the molecular mechanisms involved in its pathogenesis and treatment.

The acidic tumor microenvironment enhances PD-L1 expression via activation of STAT3 in MDA-MB-231 breast cancer cells

Tumor acidosis, a common phenomenon in solid cancers such as breast cancer, is caused by the abnormal metabolism of cancer cells. The low pH affects cells surrounding the cancer, and tumor acidosis has been shown to inhibit the activity of immune cells. Despite many previous studies, the immune surveillance mechanisms are not fully understood. We found that the expression of PD-L1 was significantly increased under conditions of extracellular acidosis in MDA-MB-231 cells. We also confirmed that the increased expression of PD-L1 mediated by extracellular acidosis was decreased when the pH was raised to the normal range. Gene set enrichment analysis (GSEA) of public breast cancer patient databases showed that PD-L1 expression was also highly correlated with IL-6/JAK/STAT3 signaling. Surprisingly, the expression of both phospho-tyrosine STAT3 and PD-L1 was significantly increased under conditions of extracellular acidosis, and inhibition of STAT3 did not increase the expression of PD-L1 even under acidic conditions in MDA-MB-231 cells. Based on these results, we suggest that the expression of PD-L1 is increased by tumor acidosis via activation of STAT3 in MDA-MB-231 cells.