Magnesium transporter protein solute carrier family 41 member 1 suppresses human pancreatic ductal adenocarcinoma through magnesium-dependent Akt/mTOR inhibition and bax-associated mitochondrial apoptosis

The Role of Magnesium in Parkinson's Disease: Status Quo and Implications for Future Research

Neurodegenerative diseases represent an increasing economic, social, and, above all, medical burden worldwide. The second most prevalent disease in this category is Parkinson's disease, surpassed only by Alzheimer's. It is a treatable but still incurable systemic disease with a pathogenesis that has not yet been elucidated. Several theories are currently being developed to explain the causes and progression of Parkinson's disease. Magnesium is one of the essential macronutrients and is absolutely necessary for life as we know it. The magnesium cation performs several important functions in the cell in the context of energetic metabolism, substrate metabolism, cell signalling, and the regulation of the homeostasis of other ions. Several of these cellular processes have been simultaneously described as being disrupted in the development and progression of Parkinson's disease. The relationship between magnesium homeostasis and the pathogenesis of Parkinson's disease has received little scientific attention to date. The aim of this review is to summarise and critically evaluate the current state of knowledge on the possible role of magnesium in the pathogenesis of Parkinson's disease and to outline possible future directions for research in this area.

Noninvasive assessment of organ-specific and shared pathways in multi-organ fibrosis using T1 mapping

Fibrotic diseases affect multiple organs and are associated with morbidity and mortality. To examine organ-specific and shared biologic mechanisms that underlie fibrosis in different organs, we developed machine learning models to quantify T1 time, a marker of interstitial fibrosis, in the liver, pancreas, heart and kidney among 43,881 UK Biobank participants who underwent magnetic resonance imaging. In phenome-wide association analyses, we demonstrate the association of increased organ-specific T1 time, reflecting increased interstitial fibrosis, with prevalent diseases across multiple organ systems. In genome-wide association analyses, we identified 27, 18, 11 and 10 independent genetic loci associated with liver, pancreas, myocardial and renal cortex T1 time, respectively. There was a modest genetic correlation between the examined organs. Several loci overlapped across the examined organs implicating genes involved in a myriad of biologic pathways including metal ion transport (SLC39A8, HFE and TMPRSS6), glucose metabolism (PCK2), blood group antigens (ABO and FUT2), immune function (BANK1 and PPP3CA), inflammation (NFKB1) and mitosis (CENPE). Finally, we found that an increasing number of organs with T1 time falling in the top quintile was associated with increased mortality in the population. Individuals with a high burden of fibrosis in ≥3 organs had a 3-fold increase in mortality compared to those with a low burden of fibrosis across all examined organs in multivariable-adjusted analysis (hazard ratio = 3.31, 95% confidence interval 1.77-6.19; P = 1.78 × 10-4). By leveraging machine learning to quantify T1 time across multiple organs at scale, we uncovered new organ-specific and shared biologic pathways underlying fibrosis that may provide therapeutic targets.

Mechanism of metal ion-induced cell death in gastrointestinal cancer

Gastrointestinal (GI) cancer is one of the most severe types of cancer, with a significant impact on human health worldwide. Due to the urgent demand for more effective therapeutic strategies against GI cancers, novel research on metal ions for treating GI cancers has attracted increasing attention. Currently, with accumulating research on the relationship between metal ions and cancer therapy, several metal ions have been discovered to induce cell death. In particular, the three novel modes of cell death, including ferroptosis, cuproptosis, and calcicoptosis, have become focal points of research in the field of cancer. Meanwhile, other metal ions have also been found to trigger cell death through various mechanisms. Accordingly, this review focuses on the mechanisms of metal ion-induced cell death in GI cancers, hoping to provide theoretical support for further GI cancer therapies.

Magnesium Transporter MgtA revealed as a Dimeric P-type ATPase

Magnesium (Mg2+) uptake systems are present in all domains of life given the vital role of this ion. Bacteria acquire Mg2+ via conserved Mg2+ channels and transporters. The transporters are required for growth when Mg2+ is limiting or during bacterial pathogenesis, but, despite their significance, there are no known structures for these transporters. Here we report the first structure of the Mg2+ transporter MgtA solved by single particle cryo-electron microscopy (cryo-EM). Using mild membrane extraction, we obtained high resolution structures of both a homodimeric form (2.9 Å), the first for a P-type ATPase, and a monomeric form (3.6 Å). Each monomer unit of MgtA displays a structural architecture that is similar to other P-type ATPases with a transmembrane domain and two soluble domains. The dimer interface consists of contacts between residues in adjacent soluble nucleotide binding and phosphotransfer regions of the haloacid dehalogenase (HAD) domain. We suggest oligomerization is a conserved structural feature of the diverse family of P-type ATPase transporters. The ATP binding site and conformational dynamics upon nucleotide binding to MgtA were characterized using a combination of cryo-EM, molecular dynamics simulations, hydrogen-deuterium exchange mass spectrometry, and mutagenesis. Our structure also revealed a Mg2+ ion in the transmembrane segments, which, when combined with sequence conservation and mutagenesis studies, allowed us to propose a model for Mg2+ transport across the lipid bilayer. Finally, our work revealed the N-terminal domain structure and cytoplasmic Mg2+ binding sites, which have implications for related P-type ATPases defective in human disease.

The role of metal ions in the occurrence, progression, drug resistance, and biological characteristics of gastric cancer

Metal ions exert pivotal functions within the human body, encompassing essential roles in upholding cell structure, gene expression regulation, and catalytic enzyme activity. Additionally, they significantly influence various pathways implicated in divergent mechanisms of cell death. Among the prevailing malignant tumors of the digestive tract worldwide, gastric cancer stands prominent, exhibiting persistent high mortality rates. A compelling body of evidence reveals conspicuous ion irregularities in tumor tissues, encompassing gastric cancer. Notably, metal ions have been observed to elicit distinct contributions to the progression, drug resistance, and biological attributes of gastric cancer. This review consolidates pertinent literature on the involvement of metal ions in the etiology and advancement of gastric cancer. Particular attention is directed towards metal ions, namely, Na, K, Mg, Ca, Fe, Cu, Zn, and Mn, elucidating their roles in the initiation and progression of gastric cancer, cellular demise processes, drug resistance phenomena, and therapeutic approaches.

Brucine Inhibits Proliferation of Pancreatic Ductal Adenocarcinoma through PI3K/AKT Pathway-induced Mitochondrial Apoptosis

INTRODUCTION

The purpose of this research was to settle the role of brucine in pancreatic ductal adenocarcinoma (PDAC) and the mechanisms involved.

METHODS

The findings of this study suggest that brucine exerts inhibitory effects on cell growth, clonogenicity, and invasive potential of Panc02 and Mia Paca-2 cells. These effects may be linked to an increase in apoptotic-prone cell population.

RESULTS

Gene sequencing data suggests that these effects are mediated through the induction of apoptosis. Experimental evidence further supports the notion that brucine reduces mitochondrial membrane potential and upregulates Bax expression while downregulating Bcl-2 expression. These effects are believed to be a result of brucine-mediated suppression of PI3K/Akt activity, which serves as a regulatory factor of mTOR, Bax, and Bcl-2. Suppression of PI3K activity enhances the tumor-suppressing effects of brucine.

CONCLUSION

Overall, these findings suggest that brucine has therapeutic potential as a remedy option for PDAC.

Plasma Exosome Gene Signature Differentiates Colon Cancer from Healthy Controls

BACKGROUND

Liquid biopsies have become an integral part of cancer management as minimally invasive options to detect molecular and genetic changes. However, current options show poor sensitivity in peritoneal carcinomatosis (PC). Novel exosome-based liquid biopsies may provide critical information on these challenging tumors. In this initial feasibility analysis, we identified an exosome gene signature of 445 genes (ExoSig445) from colon cancer patients, including those with PC, that is distinct from healthy controls.

METHODS

Plasma exosomes from 42 patients with metastatic and non-metastatic colon cancer and 10 healthy controls were isolated and verified. RNAseq analysis of exosomal RNA was performed and differentially expressed genes (DEGs) were identified by the DESeq2 algorithm. The ability of RNA transcripts to discriminate control and cancer cases was assessed by principal component analysis (PCA) and Bayesian compound covariate predictor classification. An exosomal gene signature was compared with tumor expression profiles of The Cancer Genome Atlas.

RESULTS

Unsupervised PCA using exosomal genes with greatest expression variance showed stark separation between controls and patient samples. Using separate training and test sets, gene classifiers were constructed capable of discriminating control and patient samples with 100% accuracy. Using a stringent statistical threshold, 445 DEGs fully delineated control from cancer samples. Furthermore, 58 of these exosomal DEGs were found to be overexpressed in colon tumors.

CONCLUSIONS

Plasma exosomal RNAs can robustly discriminate colon cancer patients, including patients with PC, from healthy controls. ExoSig445 can potentially be developed as a highly sensitive liquid biopsy test in colon cancer.

Structural informatic study of determined and AlphaFold2 predicted molecular structures of 13 human solute carrier transporters and their water-soluble QTY variants

Solute carrier transporters are integral membrane proteins, and are important for diverse cellular nutrient transports, metabolism, energy demand, and other vital biological activities. They have recently been implicated in pancreatic cancer and other cancer metastasis, angiogenesis, programmed cell death and proliferation, cell metabolism and chemo-sensitivity. Here we report the study of 13 human solute carrier membrane transporters using the highly accurate AlphaFold2 predictions of 3D protein structures. In the native structures, there are hydrophobic amino acids leucine (L), isoleucine (I), valine (V) and phenylalanine (F) in the transmembrane alpha-helices. These hydrophobic amino acids L, I, V, F are systematically replaced by hydrophilic amino acids glutamine (Q), threonine (T) and tyrosine (Y), thus the QTY code. Therefore, these QTY variant transporters become water-soluble without requiring detergents. We present the superposed structures of these native solute carrier transporters and their water-soluble QTY variants. The superposed structures show remarkable similarity with RMSD ~ 1 Å-< 3 Å despite > 46% protein sequence substitutions in transmembrane alpha-helices. We also show the differences of surface hydrophobicity between the native solute carrier transporters and their QTY variants. Our study may further stimulate designs of water-soluble transmembrane proteins and other aggregated proteins for drug discovery and biotechnological applications.

Induction of Cell Death in Pancreatic Tumors by Zinc and Its Fluorescence Chelator TSQ

Pancreatic ductal adenocarcinoma is a devastating cancer and is the fourth-leading cause of cancer death in the USA. Zinc is abundant in the pancreas, but its role in pancreatic cancer remains elusive. The aim of this study is to determine effects of zinc chelators in pancreatic cancer. Pdx1Cre and LSL-KrasG12D mice expressing an oncogenic mutation of KRAS develop pancreatic intraepithelial neoplasia in the pancreas. We found that EPCAM + tumors developed in the mouse pancreas store zinc that is detectable by fluorescence-activated cell sorting using N-(6-methoxy-8-quinolyl)-p-toluenesulfonamide (TSQ), a fluorescence chelator. EPCAM + TSQ + tumor cells isolated from the mouse pancreas formed organoids in matrigel. Upon treatment with N,N,N',N'-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine (TPEN), a zinc chelator, the organoids degenerated and its negative effect was rescued by co-treatment with zinc, indicating that zinc is necessary for the growth and survival of tumor organoids. Different from TPEN, TSQ treatment did not affect the organoid growth and survival. Interestingly, co-treatment with TSQ and zinc resulted in strong emission of TSQ fluorescence in the organoid and its degeneration. The combination of zinc with TSQ, but not with TPEN, also induced cell death in PANC-1, a human pancreatic cancer cell line. These results suggest that a TSQ-zinc complex formed in pancreatic tumors induces cell death if zinc is overloaded.

circSLC41A1 Resists Porcine Granulosa Cell Apoptosis and Follicular Atresia by Promoting SRSF1 through miR-9820-5p Sponging

Ovarian granulosa cell (GC) apoptosis is the major cause of follicular atresia. Regulation of non-coding RNAs (ncRNAs) was proved to be involved in regulatory mechanisms of GC apoptosis. circRNAs have been recognized to play important roles in cellular activity. However, the regulatory network of circRNAs in follicular atresia has not been fully validated. In this study, we report a new circRNA, circSLC41A1, which has higher expression in healthy follicles compared to atretic follicles, and confirm its circular structure using RNase R treatment. The resistant function of circSLC41A1 during GC apoptosis was detected by si-RNA transfection and the competitive binding of miR-9820-5p by circSLC41A1 and SRSF1 was detected with a dual-luciferase reporter assay and co-transfection of their inhibitors or siRNA. Additionally, we predicted the protein-coding potential of circSLC41A1 and analyzed the structure of circSLC41A1-134aa. Our study revealed that circSLC41A1 enhanced SRSF1 expression through competitive binding of miR-9820-5p and demonstrated a circSLC41A1–miR-9820-5p–SRSF1 regulatory axis in follicular GC apoptosis. The study adds to knowledge of the post-transcriptional regulation of follicular atresia and provides insight into the protein-coding function of circRNA.

TCF12 activates MAGT1 expression to regulate the malignant progression of pancreatic carcinoma cells

As a highly malignant gastrointestinal tumor, pancreatic carcinoma (PC) has poor prognosis due to its low early diagnosis rate, advanced tumor resection and chemotherapy resistance. Magnesium transporter 1 (MAGT1) is a magnesium ion transporter located on the cell membrane, which shows promotive effects on biological behaviors of multiple tumor cells. The aim of the present study was to investigate the role of MAGT1 in the progression of PC and its potential molecular mechanism. Based on the Gene Expression Profiling Interactive Analysis website, MAGT1 was highly expressed in tissues from patients with PC and was associated with poor prognosis. In functional experiments, MAGT1 was highly expressed in PC cell lines. The Cell Counting Kit-8, gap closure and Transwell assays, and western blot analysis, were used to investigate the effects of MAGT1 overexpression or knockdown on the biological behaviors of PC cells. It was found that MAGT1 promoted the proliferation, migration and invasion of PC cells in vitro. According to the Encyclopedia of RNA Interactomes website, transcription factor 12 (TCF12) mRNA expression level was positively correlated with MAGT1 expression level in the tissues from patients with PC. Positive targeting regulation of MAGT1 by TCF12 was also confirmed using a dual-luciferase gene reporter assay and chromatin immunoprecipitation. In addition, knockdown of TCF12 expression inhibited the proliferation and migration of PC cells, but overexpression of MAGT1 expression partly reversed this. These results suggested that TCF12 could promote the proliferation, migration and invasion of PC cells by activating MAGT1 expression, which was associated with poor prognosis. These findings suggest that MAGT1 could be a promising biomarker for the occurrence, progression and prognosis of PC.

Ionic Regulation of T-Cell Function and Anti-Tumour Immunity

The capacity of T cells to identify and kill cancer cells has become a central pillar of immune-based cancer therapies. However, T cells are characterized by a dysfunctional state in most tumours. A major obstacle for proper T-cell function is the metabolic constraints posed by the tumour microenvironment (TME). In the TME, T cells compete with cancer cells for macronutrients (sugar, proteins, and lipid) and micronutrients (vitamins and minerals/ions). While the role of macronutrients in T-cell activation and function is well characterized, the contribution of micronutrients and especially ions in anti-tumour T-cell activities is still under investigation. Notably, ions are important for most of the signalling pathways regulating T-cell anti-tumour function. In this review, we discuss the role of six biologically relevant ions in T-cell function and in anti-tumour immunity, elucidating potential strategies to adopt to improve immunotherapy via modulation of ion metabolism.

Integrative Management of Pancreatic Cancer (PDAC): Emerging Complementary Agents and Modalities

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease. The standard first-line treatment for PDAC is gemcitabine chemotherapy which, unfortunately, offers only limited chance of a lasting cure. This review further evaluates the hypothesis that the effectiveness of gemcitabine can be improved by combining it with evidence-based complementary measures. Previously, supported by clinical trial data, we suggested that a number of dietary factors and nutraceuticals can be integrated with gemcitabine therapy. Here, we evaluate a further 10 agents for which no clinical trials have (yet) been carried out but there are promising data from in vivo and/or in vitro studies including experiments involving combined treatments with gemcitabine. Two groups of complementary agents are considered: Dietary factors (resveratrol, epigallocatechin gallate, vitamin B9, capsaicin, quercetin and sulforaphane) and nutraceutical agents (artemisinin, garcinol, thymoquinone and emodin). In addition, we identified seven promising agents for which there is currently only basic (mostly in vitro) data. Finally, as a special case of combination therapy, we highlighted synergistic drug combinations involving gemcitabine with "repurposed" aspirin or metformin. We conclude overall that integrated management of PDAC currently is likely to produce the best outcome for patients and for this a wide range of complementary measures is available.

Functional inhibition of lactate dehydrogenase suppresses pancreatic adenocarcinoma progression

BACKGROUND

Pancreatic adenocarcinoma (PAAD) a highly lethal malignancy. The current use of clinical parameters may not accurately predict the clinical outcome, which further renders the unsatisfactory therapeutic outcome.

METHODS

In this study, we retrospectively analyzed the clinical-pathological characteristics and prognosis of 253 PAAD patients. Univariate, multivariate, and Kaplan-Meier survival analyses were conducted to assess risk factors and clinical outcomes. For functional study, we performed bidirectional genetic manipulation of lactate dehydrogenase A (LDHA) in PAAD cell lines to measure PAAD progression by both in vitro and in vivo assays.

RESULTS

LDHA is particularly overexpressed in PAAD tissues and elevated serum LDHA-transcribed isoenzymes-5 (LDH-5) was associated with poorer patients' clinical outcomes. Genetic overexpression of LDHA promoted the proliferation and invasion in vitro, and tumor growth and metastasis in vivo in murine PAAD orthotopic models, while knockdown of LDHA exhibited opposite effects. LDHA-induced L-lactate production was responsible for the LDHA-facilitated PAAD progression. Mechanistically, LDHA overexpression reduced the phosphorylation of metabolic regulator AMPK and promoted the downstream mTOR phosphorylation in PAAD cells. Inhibition of mTOR repressed the LDHA-induced proliferation and invasion. A natural product berberine was selected as functional inhibitor of LDHA, which reduced activity and expression of the protein in PAAD cells. Berberine inhibited PAAD cells proliferation and invasion in vitro, and suppressed tumor progression in vivo. The restoration of LDHA attenuated the suppressive effect of berberine on PAAD.

CONCLUSIONS

Our findings suggest that LDHA may be a novel biomarker and potential therapeutic target of human PAAD.

High Expression of SLC41A3 Correlates with Poor Prognosis in Hepatocellular Carcinoma

Purpose

SLC41A3 is a member of the solute carrier family 41 (SLC41) and is involved in many cellular processes as a magnesium ion transporter. Although it plays an important role in cancer formation and development, the correlation between the expression of SLC41A3 and the occurrence and prognosis of hepatocellular carcinoma (HCC) remains unclear. Therefore, this study was focused on the evaluation of the relationship between SLC41A3 and the development and prognosis of HCC.

Patients and Methods

Firstly, we collected the mRNA expression of SLC41A3 in HCC through the platform of Oncomine. Then, the subgroups of HCC were performed by the UALCAN website and the prognosis of HCC was analyzed by Kaplan-Meier Plotter database. Subsequently, immunohistochemistry (IHC) method was used to detect SLC41A3 expression in 323 clinically confirmed HCC samples and 184 non-cancerous liver tissues. Finally, function enrichment analysis was done using the LinkInterpreter module in LinkedOmics, and gene set enrichment analysis (GSEA) was performed using TCGA data set.

Results

The Oncomine database and immunohistochemical (IHC) showed higher SLC41A3 expression in HCC tissue compared to normal tissue. The expression of SLC41A3 was significantly correlated with tumor metastasis, Edmondson grade, microvascular invasion, and AFP level. Kaplan-Meier and Cox regression analyses verified that high SLC41A3 expression is a significant prognostic factor for reduced overall survival in HCC patients.

Conclusion

Our results demonstrated that high expression of SLC41A3 was the predictor of poor prognosis in HCC patients, suggesting that this protein may be a potential target for HCC therapy.

A guide to plasma membrane solute carrier proteins

This review aims to serve as an introduction to the solute carrier proteins (SLC) superfamily of transporter proteins and their roles in human cells. The SLC superfamily currently includes 458 transport proteins in 65 families that carry a wide variety of substances across cellular membranes. While members of this superfamily are found throughout cellular organelles, this review focuses on transporters expressed at the plasma membrane. At the cell surface, SLC proteins may be viewed as gatekeepers of the cellular milieu, dynamically responding to different metabolic states. With altered metabolism being one of the hallmarks of cancer, we also briefly review the roles that surface SLC proteins play in the development and progression of cancer through their influence on regulating metabolism and environmental conditions.

Emerging roles of the solute carrier family in pancreatic cancer

Pancreatic cancer is a gastrointestinal tumor with a high mortality rate, and advances in surgical procedures have only resulted in limited improvements in the prognosis of patients. Solute carriers (SLCs), which rank second among membrane transport proteins in terms of abundance, regulate cellular functions, including tumor biology. An increasing number of studies focusing on the role of SLCs in tumor biology have indicated their relationship with pancreatic cancer. The mechanism of SLC transporters in tumorigenesis has been explored to identify more effective therapies and improve survival outcomes. These transporters are significant biomarkers for pancreatic cancer, the functions of which include mainly proliferative signaling, cell death, angiogenesis, tumor invasion and metastasis, energy metabolism, chemotherapy sensitivity and other functions in tumor biology. In this review, we summarize the different roles of SLCs and explain their potential applications in pancreatic cancer treatment.

Unsupervised subtyping and methylation landscape of pancreatic ductal adenocarcinoma

Pancreatic Ductal Adenocarcinoma (PDAC) is an aggressive form of pancreatic cancer that typically manifests itself at an advanced stage and does not respond to most treatment modalities. The survival rate of a PDAC patient is less than 5%, with a median survival of just a couple of months. A better understanding of the molecular pathology of PDAC is needed to guide research for the development of better clinical treatment modalities for PDAC patients. Gene expression studies performed to date have identified different subtypes of PDAC with prognostic and clinical relevance. Subtypes identified to date are highly heterogeneous since pancreatic cancer is heterogeneous cancer. Tumor microenvironment and stroma constitute a major chunk of PDAC and contribute to the heterogeneity. Better subtyping methods are need of the hour for better prognosis and classification of PDAC for future personalized treatment. In this work, we have performed an integrated analysis of DNA methylation and gene expression datasets to provide better mechanistic and molecular insights into Pancreatic cancers, especially PDAC. The use of varied and diverse datasets has provided valuable insights into different cancer types and can play an integral role in revealing the complex nature of underlying biological mechanisms. We performed subtyping of TCGA-PAAD gene expression and methylation datasets into different subtypes using state-of-the-art normalization methods and unsupervised clustering methods that reveal latent hidden factors, leading to additional insights for subtyping. Differential expression and differential methylation were performed for each of the subtypes obtained from clustering. Our analysis gave a consensus of five cluster solution with relevant pathways like MAPK, MET. The five subtypes corresponded to the tumor and stromal subtypes. This analysis helps in distinguishing and identifying different subtypes based on enriched putative genes. These results help propose novel experimentally-verifiable PDAC subtyping and demonstrate that using varied data sets and integrated methods can contribute to disease prognostication and precision medicine in PDAC treatment.

Mg2+ Transporters in Digestive Cancers

Despite magnesium (Mg²⁺) representing the second most abundant cation in the cell, its role in cellular physiology and pathology is far from being elucidated. Mg²⁺ homeostasis is regulated by Mg²⁺ transporters including Mitochondrial RNA Splicing Protein 2 (MRS2), Transient Receptor Potential Cation Channel Subfamily M, Member 6/7 (TRPM6/7), Magnesium Transporter 1 (MAGT1), Solute Carrier Family 41 Member 1 (SCL41A1), and Cyclin and CBS Domain Divalent Metal Cation Transport Mediator (CNNM) proteins. Recent data show that Mg²⁺ transporters may regulate several cancer cell hallmarks. In this review, we describe the expression of Mg²⁺ transporters in digestive cancers, the most common and deadliest malignancies worldwide. Moreover, Mg²⁺ transporters’ expression, correlation and impact on patient overall and disease-free survival is analyzed using Genotype Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) datasets. Finally, we discuss the role of these Mg²⁺ transporters in the regulation of cancer cell fates and oncogenic signaling pathways.

Inhibition of Mg2+ Extrusion Attenuates Glutamate Excitotoxicity in Cultured Rat Hippocampal Neurons

Magnesium plays important roles in the nervous system. An increase in the Mg²⁺ concentration in cerebrospinal fluid enhances neural functions, while Mg²⁺ deficiency is implicated in neuronal diseases in the central nervous system. We have previously demonstrated that high concentrations of glutamate induce excitotoxicity and elicit a transient increase in the intracellular concentration of Mg²⁺ due to the release of Mg²⁺ from mitochondria, followed by a decrease to below steady-state levels. Since Mg²⁺ deficiency is involved in neuronal diseases, this decrease presumably affects neuronal survival under excitotoxic conditions. However, the mechanism of the Mg²⁺ decrease and its effect on the excitotoxicity process have not been elucidated. In this study, we demonstrated that inhibitors of Mg²⁺ extrusion, quinidine and amiloride, attenuated glutamate excitotoxicity in cultured rat hippocampal neurons. A toxic concentration of glutamate induced both Mg²⁺ release from mitochondria and Mg²⁺ extrusion from cytosol, and both quinidine and amiloride suppressed only the extrusion. This resulted in the maintenance of a higher Mg²⁺ concentration in the cytosol than under steady-state conditions during the ten-minute exposure to glutamate. These inhibitors also attenuated the glutamate-induced depression of cellular energy metabolism. Our data indicate the importance of Mg²⁺ regulation in neuronal survival under excitotoxicity.

A Comprehensive Prognostic and Immune Analysis of SLC41A3 in Pan-Cancer

SLC41A3, as a member of the 41^st family of solute carriers, participates in the transport of magnesium. The role of SLC41A3 in cancer prognosis and immune regulation has rarely been reported. This study was designed to analyze the expression status and prognostic significance of SLC41A3 in pan-cancers. The mRNA expression profiles of SLC41A3 were obtained from The Cancer Genome Atlas (TCGA), the Genotype-Tissue Expression (GTEx), the Broad Institute Cancer Cell Line Encyclopedia (CCLE), and the International Cancer Genome Consortium (ICGC). The Cox regression and Kaplan-Meier analyses were used to evaluate the prognostic value of SLC41A3 in pan-cancer. Furthermore, the correlation between SLC41A3 expression and immune cells infiltration, immune checkpoint, mismatch repair (MMR), DNA methyltransferase (DNMT), tumor mutation burden (TMB), and microsatellite instability (MSI) were calculated using data form TCGA database. The results showed that the expression of SLC41A3 was down-regulated in kidney renal clear cell carcinoma (KIRC), and was associated with poor overall survival and tumor-specific mortality. Whereas, the expression of SLC41A3 was up-regulated in liver hepatocellular carcinoma (LIHC), and the results of Cox regression analysis revealed that SLC41A3 was an independent factor for LIHC prognosis. Meanwhile, a nomogram including SLC41A3 and stage was built and exhibited good predictive power for the overall survival of LIHC patients. Additionally, correlation analysis suggested a significant correlation between SLC41A3 and TMB, MSI, MMR, DNMT, and immune cells infiltration in various cancers. The overall survival and disease-specific survival analysis revealed that the combined SLC41A3 expression and immune cell score, TMB, and MSI were significantly associated with clinical outcomes in ACC, LIHC, and UVM patients. Therefore, we proposed that SLC41A3 may serve as a potential prognostic biomarker for cancer.

Study on the treatment of pancreatic cancer with integrated traditional Chinese and Western medicine: A study protocol of a multicenter prospective cohort study

INTRODUCTION

Pancreatic cancer is one of the most lethal malignancies worldwide. Most patients are diagnosed at an advanced stage, which leads to a poor prognosis and a low survival rate. At present, treatment options for pancreatic cancer are limited, so it is vital to explore new treatments and strategies. Traditional Chinese medicine (TCM) is an important method for cancer prevention and treatment in China. We will conduct a multicenter, prospective cohort study to evaluate the survival and quality of life of patients with advanced pancreatic cancer treated with integrated traditional Chinese and Western medicine, further refine the core pathogenesis of TCM for pancreatic cancer, form a core prescription, and provide clinical data support for the clinical plan of integrated treatment of pancreatic cancer using Chinese and Western medicine; this will aid in the development of the best comprehensive treatment plan for patients.

METHODS AND ANALYSIS

This study will recruit patients with stage 3 to 4 pancreatic cancer in 12 medical units from April 2019 to June 2020. Patients will be divided into a Western medicine treatment group and an integrated traditional Chinese and Western medicine treatment group, with a total of 148 patients. Overall survival is the main efficacy index, while the secondary efficacy indexes are progression-free survival, tumor markers, TCM symptom grading scale, quality of life assessment, Eastern Cooperative Oncology Group (ECOG) score, and imaging assessment. A follow-up will be performed every 6 weeks ±1 week. The end point is the death of the patient or the end of the study (October 31, 2021). Statistical analysis will be performed using Statistical Packages of Social Sciences software (SPSS).

ETHICS AND DISSEMINATION

This work was supported by Beijing Municipal Science and Technology Commission and approved by the ethics committee of Guang'anmen Hospital, China Academy of Chinese Medical Sciences (Approval No. 2019-016-KY). All patients will sign a written informed consent prior to data collection. The results will be disseminated through peer-reviewed journals and conference presentations and will be openly shared after completion of the trial.

TRIAL REGISTRATION

The trial was registered with the Chinese Clinical Trials Registry (ChiCTR1900022632, pre-registration).