Circulating methylated THBS1 DNAs as a novel marker for predicting peritoneal dissemination in gastric cancer

Circulating miRNA and circulating tumor DNA application as liquid biopsy markers in gastric cancer

Liquid biopsy has been investigated as a novel method to overcome the numerous challenges in gastric cancer (GC) management. This non-invasive, feasible, and easy-to-repeat method has been shown to be cost-effective and capable of increasing diagnostic sensitivity and prognostic assessment. Additionally, it is potentially accurate to aid decision-making and personalized treatment planning. MicroRNA (miRNA) and circulating tumor DNA (ctDNA) markers can enhance GC management in various aspects, including diagnosis (mainly earlier diagnosis and the ability to perform population-based screening), prognosis (more precise stratification of prognosis), and treatment (including more accurate prediction of treatment response and earlier detection of resistance to the treatment). Concerning the treatment-related application, miRNAs' mimics and antagonists (by using two main strategies of restoring tumor suppressor miRNAs and inhibiting oncogene miRNAs) have been shown to be effective therapeutic agents. However, these need to be further validated in clinical trials. Furthermore, novel delivery systems, such as lipid-based vectors, polymeric-based vectors, and exosome-based delivery, have been developed to enhance the performance of these agents. Moreover, this paper explores the current detection and measuring methods for these markers. These approaches are categorized into direct methods (e.g., Chem-NAT, HTG EdgeSeq, and Multiplex Circulating Fireplex) and indirect methods (e.g., Reverse transcription-quantitative polymerase chain reaction (RT-qPCR), qPCR, microarray, and NGS) for miRNA detection. For ctDNA measurement, main core technologies like NGS, digital PCR, real-time PCR, and mass spectrometry are suggested.

Plasma THBS1 as a predictive biomarker for poor prognosis and brain metastasis in patients with HER2-enriched breast cancer

BACKGROUND

Thrombospondin-1 (THBS1) is a secretory adhesive glycoprotein involved in the progression of multiple malignancies, including breast cancer. However, the clinical significance and prognostic role of plasma THBS1 in breast cancer have yet to be clarified.

METHODS

Plasma THBS1 levels in 627 breast cancer patients were analyzed by enzyme-linked immunosorbent assay. Bone marrow blood was drawn from the anterior/posterior superior iliac spine to detect the presence of disseminated tumor cells (DTCs). The effects of plasma THBS1 on the clinicopathological characteristics and survival prediction of breast cancer patients were explored.

RESULTS

Plasma THBS1 did not correlate with overall survival, breast cancer-specific survival (BCSS), and distant disease-free survival (DDFS) in the entire breast cancer cohort. Notably, HER2-enriched patients with high-plasma THBS1 levels had significantly shorter BCSS (P = 0.027) and DDFS (P = 0.011) than those with low levels. Multivariate analyses revealed that plasma THBS1 was an independent prognostic marker of BCSS (P = 0.026) and DDFS (P = 0.007) in HER2-enriched patients. THBS1 levels were 24% higher in positive DTC patients than in negative DTC patients (P = 0.031), and high levels were significantly associated with poor BCSS in positive DTC patients (HR 2.08, 95% CI 1.17-3.71; P = 0.019). Moreover, high-plasma THBS1 levels were specifically associated with an increased occurrence of brain metastasis in HER2-enriched patients (P = 0.041).

CONCLUSION

These findings suggest that plasma THBS1 may be serving as an unfavorable prognosis predictor for HER2-enriched breast cancer and justifies the need for further research.

Clinical applications and perspectives of circulating tumor DNA in gastric cancer

Gastric cancer remains a leading cause of cancer-related death worldwide, largely due to inadequate screening methods, late diagnosis, and limited treatment options. Liquid biopsy has emerged as a promising non-invasive approach for cancer screening and prognosis by detecting circulating tumor components like circulating tumor DNA (ctDNA) in the blood. Numerous gastric cancer-specific ctDNA biomarkers have now been identified. CtDNA analysis provides insight into genetic and epigenetic alterations in tumors, holding promise for predicting treatment response and prognosis in gastric cancer patients. This review summarizes current research on ctDNA biology and detection technologies, while highlighting clinical applications of ctDNA for gastric cancer diagnosis, prognosis, and guiding treatment decisions. Current challenges and future perspectives for ctDNA analysis are also discussed.

Liquid Biopsy: An Emerging Diagnostic, Prognostic, and Predictive Tool in Gastric Cancer

Liquid biopsy, a minimally invasive procedure that causes minimal pain and complication risks to patients, has been extensively studied for cancer diagnosis and treatment. Moreover, it facilitates comprehensive quantification and serial assessment of the whole-body tumor burden. Several biosources obtained through liquid biopsy have been studied as important biomarkers for establishing early diagnosis, monitoring minimal residual disease, and predicting the prognosis and response to treatment in patients with cancer. Although the clinical application of liquid biopsy in gastric cancer is not as robust as that in other cancers, biomarker studies using liquid biopsy are being actively conducted in patients with gastric cancer. Herein, we aimed to review the role of various biosources that can be obtained from patients with gastric cancer through liquid biopsies, such as blood, saliva, gastric juice, urine, stool, peritoneal lavage fluid, and ascites, by dividing them into cellular and acellular components. In addition, we reviewed previous studies on the diagnostic, prognostic, and predictive biomarkers for gastric cancer using liquid biopsy and discussed the limitations of liquid biopsy and the challenges to overcome these limitations in patients with gastric cancer.

Cancer metastasis under the magnifying glass of epigenetics and epitranscriptomics

Most of the cancer-associated mortality and morbidity can be attributed to metastasis. The role of epigenetic and epitranscriptomic alterations in cancer origin and progression has been extensively demonstrated during the last years. Both regulations share similar mechanisms driven by DNA or RNA modifiers, namely writers, readers, and erasers; enzymes responsible of respectively introducing, recognizing, or removing the epigenetic or epitranscriptomic modifications. Epigenetic regulation is achieved by DNA methylation, histone modifications, non-coding RNAs, chromatin accessibility, and enhancer reprogramming. In parallel, regulation at RNA level, named epitranscriptomic, is driven by a wide diversity of chemical modifications in mostly all RNA molecules. These two-layer regulatory mechanisms are finely controlled in normal tissue, and dysregulations are associated with every hallmark of human cancer. In this review, we provide an overview of the current state of knowledge regarding epigenetic and epitranscriptomic alterations governing tumor metastasis, and compare pathways regulated at DNA or RNA levels to shed light on a possible epi-crosstalk in cancer metastasis. A deeper understanding on these mechanisms could have important clinical implications for the prevention of advanced malignancies and the management of the disseminated diseases. Additionally, as these epi-alterations can potentially be reversed by small molecules or inhibitors against epi-modifiers, novel therapeutic alternatives could be envisioned.

Techniques of staging laparoscopy and peritoneal fluid assessment in gastric cancer: a systematic review

BACKGROUND

Staging laparoscopy for gastric cancer is recommended to assess the tumor's locoregional extension and exclude peritoneal disease. As there is no consensus on optimizing the procedure's diagnostic accuracy, we aimed to systematically review the literature on operative techniques, followed by peritoneal lavage fluid assessment in gastric cancer patients. Specifically, we sought to indicate the most common characteristics of the procedure and cytological evaluation.

METHODS

This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The protocol for this systematic review was registered on PROSPERO database (CRD: 42022306746). On September 2022, a search was carried out using Embase, Medline ALL, Cochrane Central Register of Controlled Trials, and Web of Science Core Collection.

RESULTS

The search identified 1632 studies on staging laparoscopy and 2190 studies on peritoneal fluid assessment. Some 212 studies were included. Open Hasson was the method of choice in accessing the peritoneal cavity in 65% of the studies, followed by establishing a pneumoperitoneum at 10-12 mmHg in 52% of reports. Most frequently, the patient was positioned supine (70%), while a 30° scope and three ports were used to assess the peritoneal cavity clockwise (72%, 77%, and 85%, respectively). Right and left upper abdomen quadrants were the predominant area of laparoscopic exploration (both 65%), followed by the primary tumor region (54%), liver and pelvis (both 30%), and small bowel and spleen (19% and 17%, respectively). Regions of peritoneal lavage and aspiration were limited to the pelvis (50%), followed by right and left upper abdomen quadrants (37.5% and 50%, respectively). No studies compared different methods of operative techniques or analysis of ascites/fluid.

CONCLUSIONS

This study indicates a high heterogeneity in the technique of staging laparoscopy and peritoneal fluid assessment in gastric cancer patients. Further research and initiatives to reach a consensus on the standardization of the procedure are warranted.

Prognostic model of kidney renal clear cell carcinoma using aging-related long noncoding RNA signatures identifies THBS1-IT1 as a potential prognostic biomarker for multiple cancers

Aging is responsible for the main intrinsic triggers of cancers; however, the studies of aging risk factors in cancer animal models and cancer patients are rare and insufficient to be represented in cancer clinical trials. For a better understanding of the complex regulatory networks of aging and cancers, 8 candidate aging related long noncoding RNAs (CarLncs) identified from the healthy aging models, centenarians and their offsprings, were selected and their association with kidney renal clear cell carcinoma (KIRC) was explored by series of cutting edge analyses such as support vector machine (SVM) and random forest (RF) algorithms. Using data downloaded from TCGA and GTEx databases, a regulatory network of CarLncs-miRNA-mRNA was constructed and five genes within the network were screened out as aging related feature genes for developing KIRC prognostic models. After a strict filtering pipeline for modeling, a formula using the transcript per million (TPM) values of feature genes "LncAging_score = 0.008* MMP11 + 0.066* THBS1-IT1 + (-0.014)* DYNLL2 + (-0.030)* RMND5A+ 0.008* PEG10" was developed. ROC analysis and nomogram suggest our model achieves a great performance in KIRC prognosis. Among the 8 CarLncs, we found that THBS1-IT1 was significantly dysregulated in 12 cancer types. A comprehensive pan-cancer analysis demonstrated that THBS1-IT1 is a potential prognostic biomarker in not only KIRC but also multiple cancers, such as LUSC, BLCA, GBM, LGG, MESO, PAAD, STAD and THCA, it was correlated with tumor microenvironment (TME) and tumor immune cell infiltration (TICI) and its high expression was related with poor survival.

Comparison of the mutation patterns between tumor tissue and cell-free DNA in stage IV gastric cancer

Compared to stage I-III gastric cancer (GC), the level of cell-free DNA (cfDNA) was significantly higher in stage IV GC. The mutation patterns of different metastatic patterns between cfDNA and tumor DNA in stage IV GC have not yet been reported. We used next-generation sequencing (NGS) to analyze cfDNA and tumor DNA in 56 stage IV GC patients. Tumor DNA and cfDNA were analyzed using a 29-gene NGS panel. In tumor samples, the most commonly mutated gene was TP53 (64%), followed by ARID1A (62%), KMT2C (60%) and KMT2D (58%). In cfDNA samples, the most commonly mutated genes were FAT4 (19%) and MACF1 (19%), followed by KMT2D (18%), ARID1A (14%) and LRP1B (14%). The concordance of mutation patterns in these 29 genes was 42.0% between cfDNA and tumor DNA. A specificity of 100% was found when using the mutation status of cfDNA to predict mutations in tumor samples. The sensitivity of the mutation status of cfDNA to predict mutation in tumor samples was highest in FAT4 (88.9%), followed by MACF1 (80%), CDH1 (75%) and PLB1 (75%). For cfDNA with PLB1 mutations, patients were more likely to develop distant lymphatic metastasis than peritoneal metastasis. Patients with multiple-site metastases had significantly more mutated spots than patients with single-site metastasis. Due to the high sensitivity and specificity of some genes in the prediction of mutation in tumor samples, monitoring the mutation pattern of cfDNA may be useful in the stage IV GC treatment.

Cromolyn prevents cerebral vasospasm and dementia by targeting WDR43

Background

Cerebral vasospasm (CV) can cause inflammation and damage to neuronal cells in the elderly, leading to dementia.

Purpose

This study aimed to investigate the genetic mechanisms underlying dementia caused by CV in the elderly, identify preventive and therapeutic drugs, and evaluate their efficacy in treating neurodegenerative diseases.

Methods

Genes associated with subarachnoid hemorrhage and CV were acquired and screened for differentially expressed miRNAs (DEmiRNAs) associated with aneurysm rupture. A regulatory network of DEmiRNAs and mRNAs was constructed, and virtual screening was performed to evaluate possible binding patterns between Food and Drug Administration (FDA)-approved drugs and core proteins. Molecular dynamics simulations were performed on the optimal docked complexes. Optimally docked drugs were evaluated for efficacy in the treatment of neurodegenerative diseases through cellular experiments.

Results

The study found upregulated genes (including WDR43 and THBS1) and one downregulated gene associated with aneurysm rupture. Differences in the expression of these genes indicate greater disease risk. DEmiRNAs associated with ruptured aortic aneurysm were identified, of which two could bind to THBS1 and WDR43. Cromolyn and lanoxin formed the best docking complexes with WDR43 and THBS1, respectively. Cellular experiments showed that cromolyn improved BV2 cell viability and enhanced Aβ42 uptake, suggesting its potential as a therapeutic agent for inflammation-related disorders.

Conclusion

The findings suggest that WDR43 and THBS1 are potential targets for preventing and treating CV-induced dementia in the elderly. Cromolyn may have therapeutic value in the treatment of Alzheimer's disease and dementia.

Epigenetic signatures in gastric cancer: current knowledge and future perspectives

INTRODUCTION

Gastric cancer (GC) is the fifth most common malignancy in the world and accounts for 7.7% of all cancer-related deaths. Early diagnosis of GC is critical in terms of prognosis, and aberrations at the molecular level, especially epigenetic alterations, manifest much earlier than histological findings. In recent years, there has been a great deal of research on the epigenomic profile of GC, and epigenetic alterations seem to play a more important role than genetic factors. With the introduction of epigenetic drugs into clinical use in the last decade, the importance of the epigenetic background of GC has increased considerably.

AREAS COVERED

In this review, we summarize the role of methylation changes, histone modifications, and non-coding RNAs in the pathogenesis of GC and how these signatures can be used as diagnostic and therapeutic targets in clinical management.

EXPERT OPINION

Epigenetic alterations take place before most genetic aberrations observed in GC and may have an initiating role in the pathogenesis of GC. They can be used as biomarkers in risk calculation, early diagnosis, and evaluation of prognosis of GC, as well as treatment targets.

Liquid biopsy in gastric cancer: predictive and prognostic biomarkers

Gastric cancer (GC) is a high-incidence cancer worldwide. Most patients are diagnosed at an advanced stage, by which time they have limited treatment options and poor prognosis. Early diagnosis and precise treatment are important. In the past few years, emerging research has been conducted on the use of non-invasive liquid biopsy, with its advantages of minimal invasiveness and repeated sampling, to monitor tumor occurrence and recurrence in real time and to evaluate prognosis and treatment response. Many studies have demonstrated the potential of liquid biopsy in GC, and the detection of circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), circulating free DNA (cfDNA), and exosomes has achieved gratifying results. In this review, we summarize evolving technologies for and information regarding liquid biopsy, the most recently discovered GC liquid biopsy biomarkers, and ongoing clinical trials and discuss the challenges and application prospects of liquid biopsy in GC.

DNA Methylation: An Important Biomarker and Therapeutic Target for Gastric Cancer

Gastric cancer (GC) is a very common malignancy with a poor prognosis, and its occurrence and development are closely related to epigenetic modifications. Methylation of DNA before or during gastric cancer is an interesting research topic. This article reviews the studies on DNA methylation related to the cause, diagnosis, treatment, and prognosis of gastric cancer and aims to find cancer biomarkers to solve major human health problems.