Low-density lipoprotein receptor expression is involved in the beneficial effect of photodynamic therapy using talaporfin sodium on gastric cancer cells

Energy metabolism: a new target for gastric cancer treatment

Gastric cancer is the fifth most common malignancy worldwide having the fourth highest mortality rate. Energy metabolism is key and closely linked to tumour development. Most important in the reprogramming of cancer metabolism is the Warburg effect, which suggests that tumour cells will utilise glycolysis even with normal oxygen levels. Various molecules exert their effects by acting on enzymes in the glycolytic pathway, integral to glycolysis. Second, mitochondrial abnormalities in the reprogramming of energy metabolism, with consequences for glutamine metabolism, the tricarboxylic acid cycle and oxidative phosphorylation, abnormal fatty acid oxidation and plasma lipoprotein metabolism are important components of tumour metabolism. Third, inflammation-induced oxidative stress is a danger signal for cancer. Fourth, patterns of signalling pathways involve all aspects of metabolic transduction, and many clinical drugs exert their anticancer effects through energy metabolic signalling. This review summarises research on energy metabolism genes, enzymes and proteins and transduction pathways associated with gastric cancer, and discusses the mechanisms affecting their effects on postoperative treatment resistance and prognoses of gastric cancer. We believe that an in-depth understanding of energy metabolism reprogramming will aid the diagnosis and subsequent treatment of gastric cancer.

Single-dose local intraosseous injection of simvastatin suppresses breast cancer with tumor vascular normalization

Tumor vessels play important roles in cancer development and angiogenesis has been characterized as an essential process for tumor cell tumor growth. Our previous studies found that a single-dose local intraosseous simvastatin injection rapidly and long-termly mobilized bone marrow-derived endothelial progenitor cells to peripheral blood, promoting angiogenesis and ameliorating ischemia injury. However, whether intraosseous injection of simvastatin participates in cancer progression and the role of angiogenesis enhancement in this process remain unknown. In this study, we found that intraosseous injection of simvastatin improves tumor vascular structure, along with increasing the percentage of pericyte coverage on tumor vessels, and reducing vascular permeability, tumor hypoxia and tumor necrosis. Further, we demonstrate that a single-dose local intraosseous simvastatin injection suppresses tumor growth, facilitates sensitivity of chemotherapy and prolongs survival in breast cancer-bearing mice. In addition, oral application, intravenous, subcutaneous and intraperitoneal injection of simvastatin do not show these effects. Taken together, these results demonstrate that intraosseous injection of simvastatin suppresses breast cancer with tumor vascular normalization, which might be a promising strategy for cancer treatment.

Pathological Mechanism of Photodynamic Therapy and Photothermal Therapy Based on Nanoparticles

The ultimate goal of phototherapy based on nanoparticles, such as photothermal therapy (PTT) which generates heat and photodynamic therapy (PDT) which not only generates reactive oxygen species (ROS) but also induces a variety of anti-tumor immunity, is to kill tumors. In addition, due to strong efficacy in clinical treatment with minimal invasion and negligible side effects, it has received extensive attention and research in recent years. In this paper, the generations of nanomaterials in PTT and PDT are described separately. In clinical application, according to the different combination pathway of nanoparticles, it can be used to treat different diseases such as tumors, melanoma, rheumatoid and so on. In this paper, the mechanism of pathological treatment is described in detail in terms of inducing apoptosis of cancer cells by ROS produced by PDT, immunogenic cell death to provoke the maturation of dendritic cells, which in turn activate production of CD4+ T cells, CD8+T cells and memory T cells, as well as inhibiting heat shock protein (HSPs), STAT3 signal pathway and so on.

Photodynamic therapy regulates fate of cancer stem cells through reactive oxygen species

Photodynamic therapy (PDT) is an effective and promising cancer treatment. PDT directly generates reactive oxygen species (ROS) through photochemical reactions. This oxygen-dependent exogenous ROS has anti-cancer stem cell (CSC) effect. In addition, PDT may also increase ROS production by altering metabolism, endoplasmic reticulum stress, or potential of mitochondrial membrane. It is known that the half-life of ROS in PDT is short, with high reactivity and limited diffusion distance. Therefore, the main targeting position of PDT is often the subcellular localization of photosensitizers, which is helpful for us to explain how PDT affects CSC characteristics, including differentiation, self-renewal, apoptosis, autophagy, and immunogenicity. Broadly speaking, excess ROS will damage the redox system and cause oxidative damage to molecules such as DNA, change mitochondrial permeability, activate unfolded protein response, autophagy, and CSC resting state. Therefore, understanding the molecular mechanism by which ROS affect CSCs is beneficial to improve the efficiency of PDT and prevent tumor recurrence and metastasis. In this article, we review the effects of two types of photochemical reactions on PDT, the metabolic processes, and the biological effects of ROS in different subcellular locations on CSCs.

Verteporfin-photodynamic therapy is effective on gastric cancer cells

Photodynamic therapy (PDT) induces photochemical reactions, resulting in the destruction of tumor cells via singlet (S1) oxygen production. This cellular destruction occurs specifically in tumor cells, following selective accumulation of a photosensitizer and its excitation by a specific wavelength. Verteporfin (VP) is a second-generation photosensitizer that is currently being used worldwide in PDT to treat age-related macular degeneration. In addition, clinical trials with VP-PDT demonstrated anti-tumor efficacy and overall safety when used to treat locally advanced pancreatic cancer. In the present study, we examined the anti-tumor effect of VP-PDT on gastric cancer (GC) cell lines in vitro to conduct an initial assessment of its potential clinical applicability to this specific type of cancer. We evaluated the viability of MKN45 and MKN74 cancer cell lines after VP-PDT exposure and calculated the half maximal effective concentration (EC₅₀) values for VP. Apoptosis in VP-PDT-exposed GC cells was observed. Furthermore, the EC₅₀ values for a 30-min treatment with VP (2.5 J/cm² of 660 nm LED light) were 0.61 and 1.21 µM for MKN45 and MKN74, respectively. When VP treatment times were increased, the EC₅₀ values decreased. In conclusion, VP-PDT may be developed as an effective treatment for GC.