Amido-Bridged Nucleic Acid-Modified Antisense Oligonucleotides Targeting SYT13 to Treat Peritoneal Metastasis of Gastric Cancer

Advancing cancer treatments: The role of oligonucleotide-based therapies in driving progress

Although recent advancements in cancer immunology have resulted in the approval of numerous immunotherapies, minimal progress has been observed in addressing hard-to-treat cancers. In this context, therapeutic oligonucleotides, including interfering RNAs, antisense oligonucleotides, aptamers, and DNAzymes, have gained a central role in cancer therapeutic approaches due to their capacity to regulate gene expression and protein function with reduced toxicity compared with conventional chemotherapeutics. Nevertheless, systemic administration of naked oligonucleotides faces many extra- and intracellular challenges that can be overcome by using effective delivery systems. Thus, viral and non-viral carriers can improve oligonucleotide stability and intracellular uptake, enhance tumor accumulation, and increase the probability of endosomal escape while minimizing other adverse effects. Therefore, gaining more insight into fundamental mechanisms of actions of various oligonucleotides and the challenges posed by naked oligonucleotide administration, this article provides a comprehensive review of the recent progress on oligonucleotide delivery systems and an overview of completed and ongoing cancer clinical trials that can shape future oncological treatments.

Therapeutic Potential of Antibody Targeting Neuronal Pentraxin Receptor in Esophageal Squamous Cell Carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) has a poor prognosis despite advances in multidisciplinary treatments and immune checkpoint inhibitors. We previously reported that neural pentraxin receptor (NPTXR), a transmembrane protein mainly expressed in the brain and involved in synaptic transmission, is implicated in gastric cancer malignancy. This study evaluated the expression and function of NPTXR in ESCC, the therapeutic potential of monoclonal antibody (mAb) against NPTXR, and its prognostic value in ESCC patients.

METHODS

The study involved analyzing the NPTXR expression in 21 ESCC cell lines and total 371 primary ESCC tissue samples using quantitative reverse-transcription polymerase chain reaction and immunohistochemistry. The impact of NPTXR on the malignant behavior of ESCC was examined using small interfering RNA-mediated knockdown and a subsequent assessment of cell proliferation, apoptosis, and adhesion. This study further investigated the efficacy of anti-NPTXR mAb in vitro and associations between the expression of NPTXR messenger RNA (mRNA) and protein with clinicopathological factors and the prognosis.

RESULTS

NPTXR was overexpressed in several ESCC cell lines and primary ESCC tissues. Knockdown of NPTXR in ESCC cells resulted in reduced proliferation, increased apoptosis, and decreased cell adhesion. The mAb against NPTXR significantly inhibited ESCC cell proliferation in vitro. A high NPTXR expression in patient tissues was correlated with a worse overall survival, suggesting its potential as a prognostic biomarker.

CONCLUSIONS

NPTXR influences the malignant behavior of ESCC cells. Anti-NPTXR mAb may be a promising therapeutic agent, and its expression in ESCC tissues may serve as a prognostic biomarker.

Synaptotagmin 13 Could Drive the Progression of Esophageal Squamous Cell Carcinoma Through Upregulating ACRV1

SYT13 is one of the atypical members of the synaptotagmin (SYT) family whose function has attracted considerable attention in recent years. Although SYT13 has been studied in several types of human cancers, such as lung cancer, its role in esophageal squamous cell carcinoma (ESCC) is still unclear. It was demonstrated that SYT13 is significantly upregulated in ESCC tissues compared with normal ones and correlated with higher degree of malignancy. Knockdown of SYT13 could inhibit ESCC cell proliferation and migration, while promoting cell apoptosis. Meanwhile, ESCC cells with relatively lower SYT13 expression grew slower in vivo and finally formed smaller xenografts. Furthermore, acrosomal vesicular protein 1 was identified as a potential downstream target of SYT13, which regulates cell phenotypes of ESCC cells in cooperation with SYT13. All the in vitro and in vivo results in this study identified that SYT13 silencing could be an effective strategy to inhibit the development of ESCC, which could be considered as a promising therapeutic target in the treatment of ESCC.

Efficient systemic CNS delivery of a therapeutic antisense oligonucleotide with a blood-brain barrier-penetrating ApoE-derived peptide

Antisense oligonucleotide (ASO) has emerged as a promising therapeutic approach for treating central nervous system (CNS) disorders by modulating gene expression with high selectivity and specificity. However, the poor permeability of ASO across the blood-brain barrier (BBB) diminishes its therapeutic success. Here, we designed and synthesized a series of BBB-penetrating peptides (BPP) derived from either the receptor-binding domain of apolipoprotein E (ApoE) or a transferrin receptor-binding peptide (THR). The BPPs were conjugated to phosphorodiamidate morpholino oligomers (PMO) that are chemically analogous to the 2'-O-(2-methoxyethyl) (MOE)-modified ASO approved by the FDA for treating spinal muscular atrophy (SMA). The BPP-PMO conjugates significantly increased the level of full-length SMN2 in the patient-derived SMA fibroblasts in a concentration-dependent manner with minimal to no toxicity. Furthermore, the systemic administration of the most potent BPP-PMO conjugates significantly increased the expression of full-length SMN2 in the brain and spinal cord of SMN2 transgenic adult mice. Notably, BPP8-PMO conjugate showed a 1.25-fold increase in the expression of full-length functional SMN2 in the brain. Fluorescence imaging studies confirmed that 78% of the fluorescently (Cy7)-labelled BPP8-PMO reached brain parenchyma, with 11% uptake in neuronal cells. Additionally, the BPP-PMO conjugates containing retro-inverso (RI) D-BPPs were found to possess extended half-lives compared to their L-counterparts, indicating increased stability against protease degradation while preserving the bioactivity. This delivery platform based on BPP enhances the CNS bioavailability of PMO targeting the SMN2 gene, paving the way for the development of systemically administered neurotherapeutics for CNS disorders.

Killer cell lectin-like receptor G2 facilitates aggressive phenotypes of gastric cancer cells via dual activation of the ERK1/2 and JAK/STAT pathways

BACKGROUND

Advanced gastric cancer (GC) has a poor prognosis. This study aimed to identify novel GC-related genes as potential therapeutic targets.

METHODS

Killer cell lectin-like receptor G2 (KLRG2) was identified as a candidate gene by transcriptome analysis of metastatic GC tissues. Small interfering RNA-mediated KLRG2 knockdown in human GC cell lines was used to investigate KLRG2 involvement in signaling pathways and functional behaviors in vitro and in vivo. Clinicopathological data were analyzed in patients stratified according to tumor KLRG2 mRNA expression.

RESULTS

KLRG2 knockdown in GC cells decreased cell proliferation, migration, and invasion; caused cell cycle arrest in G2/M phase; induced apoptosis via caspase activation; suppressed JAK/STAT and MAPK-ERK1/2 pathway activities; and upregulated p53 and p38 MAPK activities. In mouse xenograft models of peritoneal metastasis, the number and weight of disseminated GC nodules were decreased by KLRG2 knockdown. High tumor levels of KLRG2 mRNA were significantly associated with lower 5-year overall survival (OS) and relapse-free survival (RFS) rates in patients with Stage I-III GC (5-year OS rate: 64.4% vs. 80.0%, P = 0.009; 5-year RFS rate: 62.8% vs. 78.1%, P = 0.030).

CONCLUSIONS

KLRG2 knockdown attenuated the malignant phenotypes of GC cells via downregulation of JAK/STAT and MAPK-ERK1/2 pathway activity and upregulation of p38 MAPK and p53. Targeted suppression of KLRG2 may serve as a new treatment approach for GC.

Absence of Hypercoagulation Status after Neoadjuvant Treatment is Associated with Favorable Prognosis in Patients Undergoing Subtotal Esophagectomy for Esophageal Squamous Cell Carcinoma

BACKGROUND

Abnormal activation of the coagulation system is associated with malignant tumor progression. Although neoadjuvant treatment (NAT) for resectable esophageal squamous cell carcinoma (ESCC) is the standard of care, the correlation between coagulation status and prognosis of patients undergoing preoperative treatment is insufficiently understood.

METHODS

Patients (n = 200) who underwent radical subtotal esophagectomy after preoperative treatment for ESCC between January 2012 and December 2021were included in the analysis. Plasma D-dimer and fibrinogen levels and their combined indices (non-hypercoagulation; D-dimer and fibrinogen levels within the upper normal limit, or hypercoagulation; D-dimer or fibrinogen levels above the upper normal limit) were determined before and after NAT and correlated to clinicopathological factors and prognosis.

RESULTS

The nonhypercoagulation group achieved superior overall survival (OS) than the hypercoagulation group (5-year OS rates = 89% vs. 55%; hazard ratio 3.62, P = 0.0008) when determined according to coagulation status after NAT. Multivariate analysis showed that hypercoagulation after NAT served as an independent factor for poor postoperative OS (hazard ratio 3.20; P = 0.0028). The nonhypercoagulation group achieved significantly better disease-free survival (76% vs. 54%; P = 0.0065) than the hypercoagulation group that experienced a significantly higher rate of hematogenous metastasis as an initial recurrence (P = 0.0337).

CONCLUSIONS

Hypercoagulation state after NAT served as a valid indicator correlating with postoperative outcomes of patients with ESCC who underwent NAT followed by radical subtotal esophagectomy.

Emerging therapeutic approaches for peritoneal metastases from gastrointestinal cancers

Peritoneal metastases from gastrointestinal malignancies present difficult management decisions, with options consisting primarily of systemic chemotherapy or major surgery with or without hyperthermic intraperitoneal chemotherapy. Current research is investigating expanding therapeutic modalities, and the aim of this review is to provide an overview of the existing and emerging therapies for the peritoneal metastases from gastrointestinal cancers, primarily through the recent literature (2015 and newer). These include the current data with systemic therapy and cytoreduction with hyperthermic intraperitoneal or pressurized intraperitoneal aerosol chemotherapy, as well as novel promising modalities under investigation, including dominating oncolytic viral therapy and adoptive cellular, biologic, and bacteria therapy, or nanotechnology. The novel diverse strategies, although preliminary and preclinical in murine models, individually and collectively contribute to the treatment of peritoneal metastases, offering hope for improved outcomes and quality of life. We foresee that these evolving treatment approaches will facilitate the transfer of knowledge and data among studies and advance discovery of new drugs and optimized treatments for patients with peritoneal metastases.

Gene-editing technology, from macromolecule therapeutics to organ transplantation: Applications, limitations, and prospective uses

Gene editing technologies (GETs) could induce gene knockdown or gene knockout for biomedical applications. The clinical success of gene silence by RNAi therapies pays attention to other GETs as therapeutic approaches. This review aims to highlight GETs, categories, mechanisms, challenges, current use, and prospective applications. The different academic search engines, electronic databases, and bibliographies of selected articles were used in the preparation of this review with a focus on the fundamental considerations. The present results revealed that, among GETs, CRISPR/Cas9 has higher editing efficiency and targeting specificity compared to other GETs to insert, delete, modify, or replace the gene at a specific location in the host genome. Therefore, CRISPR/Cas9 is talented in the production of molecular, tissue, cell, and organ therapies. Consequently, GETs could be used in the discovery of innovative therapeutics for genetic diseases, pandemics, cancer, hopeless diseases, and organ failure. Specifically, GETs have been used to produce gene-modified animals to spare human organ failure. Genetically modified pigs are used in clinical trials as a source of heart, liver, kidneys, and lungs for xenotransplantation (XT) in humans. Viral, non-viral, and hybrid vectors have been utilized for the delivery of GETs with some limitations. Therefore, extracellular vesicles (EVs) are proposed as intelligent and future cargoes for GETs delivery in clinical applications. This study concluded that GETs are promising for the production of molecular, cellular, and organ therapies. The use of GETs as XT is still in the early stage as well and they have ethical and biosafety issues.

Increased STX3 transcript and protein levels were associated with poor prognosis in two independent cohorts of esophageal squamous cell carcinoma patients

BACKGROUND

Some conventional prognostic biomarkers for esophageal squamous cell carcinoma (ESCC) have the disadvantage that they have only been investigated at the level of either mRNA or protein levels or only in individual cohorts. Associations between Syntaxin 3 (STX3) expression and malignancy have been reported in several tumor types but not in ESCC. Here, we investigated the levels of both STX3 mRNA and protein, and its prognostic potential in two independent cohorts of patients with ESCC.

METHODS

STX3 mRNA levels were examined in surgical specimens by quantitative PCR in a cohort that included 176 ESCC patients. STX3 protein levels were investigated in surgically resected ESCC tissues by immunohistochemistry using tissue microarrays in a different cohort of 177 ESCC patients. Correlations were analyzed between the expression of STX3 mRNA and protein with clinicopathological factors and long-term prognosis.

RESULTS

Quantitative PCR indicated a significant association between high level of STX3 mRNA expression and lymph node involvement, pathological stage, and poor overall survival. The multivariate analysis demonstrated that high STX3 mRNA expression was independently associated with poor overall survival outcomes. Immunohistochemistry revealed that STX3 protein expression in ESCC tissues and high STX3 protein expression were also significantly correlated with unfavorable overall survival.

CONCLUSIONS

Overexpression of STX3 mRNA and protein may serve as potential prognostic biomarkers for ESCC patients.

Risk Stratification by Tissue GAD1 Expression Level in Curatively Resected Esophageal Squamous Cell Carcinoma

BACKGROUND/AIM

To improve patient management, new biomarkers are required that stratify prognosis. Here we focused on glutamic acid decarboxylase 1 (GAD1), which is associated with proliferation of lung cancer cells, and investigated its expression and function in esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

We evaluated changes in the proliferative potential of ESCC cell lines using small interfering RNA-mediated GAD1 knockdown techniques. We analyzed GAD1 protein expression using a tissue microarray (TMA) and measured GAD1 mRNA expression to evaluate correlations between the expression level of each tissue and postoperative outcomes of two independent cohorts (the TMA and mRNA cohorts) of patients who underwent radical esophagectomy.

RESULTS

GAD1 knockdown reduced cell proliferation. In the TMA cohort, high GAD1 expression significantly correlated with lymph node metastasis and advanced stage. Disease-free survival was significantly shorter in the group with high GAD1 expression, as was overall survival. Multivariate analysis of overall survival showed that positivity for GAD1 was an independent prognostic factor for poor survival. In the mRNA cohort, GAD1 mRNA expression in ESCC tissues was significantly up-regulated compared with that in adjacent noncancerous mucosal tissues. When patients were divided into high- and low-expression groups according to the median GAD1 mRNA expression level in ESCC tissues, overall survival was significantly shortened in the high GAD1 expression group. The incidence of initial hematogenous recurrence was significantly higher in the group with high GAD1 expression.

CONCLUSION

GAD1 expression mediates the proliferative potential of ESCC cells, and a high level may serve as a useful prognostic biomarker for patients with ESCC.

Modified Albumin-Bilirubin Grade optimized for risk stratification of patients with stage II-III gastric cancer

PURPOSE

The albumin-bilirubin (ALBI) grade is calculated using albumin and bilirubin values. We determined the optimal cutoff value of the ALBI grade for predicting the postoperative prognosis of gastric cancer (GC).

METHODS

We retrospectively reviewed a multicenter database of 3571 patients who underwent gastrectomy for GC between January 2010 and December 2014. The modified ALBI (mALBI) grade was determined using cutoff values: grade 1 (mALBI ≤  - 2.70), 2 (mALBI - 2.70 to - 2.10), and 3 (mALBI >  - 2.10). We used a validation cohort to evaluate reproducibility.

RESULTS

The entire cohort (n = 956) was randomly assigned to the learning or validation cohorts (n = 478 each). The former was categorized into the following groups by the preoperative mALBI grade: grade 1 (n = 235), grade 2 (n = 162), and grade 3 (n = 81). The disease-specific survival (DSS) rates of the learning and validation cohorts were significantly shortened in association with higher mALBI grade (learning, p = 0.0068; validation, p = 0.0100). A multivariate analysis revealed that mALBI grade 3 served as an independent prognostic factor for DSS. Furthermore, mALBI grade 2 or 3 was associated with a greater risk of disease-specific death in most subgroups.

CONCLUSION

The mALBI grade accurately predicted the long-term postoperative prognosis of locally advanced GC.

Identification of stromal cell-derived factor 4 as a liquid biopsy-based diagnostic marker in solid cancers

There is a need for serum diagnostic biomarkers to improve the prognosis of solid malignant tumors. Here, we conducted a single-institutional study to evaluate the diagnostic performance of serum stromal cell-derived factor 4 (SDF4) levels in cancer patients. Serum samples were collected from a total of 582 patients with solid cancers including gastric cancer (GC) and 80 healthy volunteers. SDF4 protein levels in sera, and conditioned media or lysates of human GC cell lines were measured by enzyme-linked immunosorbent assay, and those in GC tissue by immunohistochemistry. Serum SDF4 levels were higher in patients with cancer than the healthy control in all cancer type. Regarding GC, serum SDF4 levels distinguished healthy controls from GC patients with the area under the curve value of 0.973, sensitivity of 89%, and specificity of 99%. Serum SDF4 levels were significantly elevated in patient with early stage GC. In immunohistochemistry, the frequency of SDF4-positive GC tumors did not vary significantly between GC stages. The ability of human GC cell lines to both produce and secrete SDF4 was confirmed in vitro. In conclusion, serum SDF4 levels could be a promising candidate for a novel diagnostic biomarker for GC and other malignancies.

Semaphorin 3 C enhances putative cancer stemness and accelerates peritoneal dissemination in pancreatic cancer

PURPOSE

Semaphorins, axon guidance cues in neuronal network formation, have been implicated in cancer progression. We previously identified semaphorin 3 C (SEMA3C) as a secreted protein overexpressed in pancreatic ductal adenocarcinoma (PDAC). We, therefore, hypothesized that SEMA3C supports PDAC progression. In this study, we aimed to investigate the clinical features of SEMA3C, especially its association with chemo-resistance and peritoneal dissemination.

METHODS

In resected PDAC tissues, we assessed the relationship between SEMA3C expression and clinicopathological features by immunohistochemistry. In vitro studies, we have shown invasion assay, pancreatosphere formation assay, colony formation assay, cytotoxicity assay, and activation of SEMA3C downstream targets (c-Met, Akt, mTOR). In vivo, we performed a preclinical trial to confirm the efficacy of SEMA3C shRNA knockdown and Gemcitabine and nab-Paclitaxel (GnP) in an orthotopic transplantation mouse model and in peritoneal dissemination mouse model.

RESULTS

In resected PDAC tissues, SEMA3C expression correlated with invasion and peritoneal dissemination after surgery. SEMA3C promoted cell invasion, self-renewal, and colony formation in vitro. We further demonstrated that SEMA3C knockdown increased Gem-induced cytotoxicity by suppressing the activation of the Akt/mTOR pathway via the c-Met receptor. Combination therapy with SEMA3C knockdown and GnP reduced tumor growth and peritoneal dissemination.

CONCLUSIONS

SEMA3C enhances peritoneal dissemination by regulating putative cancer stemness and Gem resistance and activates phosphorylation of the Akt/mTOR pathway via c-Met. Our findings provide a new avenue for therapeutic strategies in regulating peritoneal dissemination during PDAC progression.

Site-specific protein biomarkers in gastric cancer: a comprehensive review of novel biomarkers and clinical applications

INTRODUCTION

Gastric cancer (GC) is the fifth most common cancer and the fourth leading cause of cancer-related death worldwide, thus representing a significant global health burden. Early detection and monitoring of GC are essential to improve patient outcomes. While traditional cancer biomarkers such as carcinoembryonic antigen, carbohydrate antigen (CA) 19-9, and CA 72-4 are widely used, their limited sensitivity and specificity necessitate the exploration of alternative biomarkers.

AREAS COVERED

This review comprehensively analyzes the landscape of GC protein biomarkers identified from 2019 to 2022, with a focus on tissue, blood, urine, saliva, gastric juice, ascites, and exhaled breath as sample sources. We address the potential clinical applications of these biomarkers in early diagnosis, monitoring recurrence, and predicting survival and therapeutic response of GC patients.

EXPERT OPINION

The discovery of novel protein biomarkers holds great promise for improving the clinical management of GC. However, further validation in large, diverse cohorts is needed to establish the clinical utility of these biomarkers. Integrating these biomarkers with existing diagnostic and monitoring approaches will likely lead to improved personalized treatment plans and patient outcomes.

Role of synaptotagmin 13 (SYT13) in promoting breast cancer and signaling pathways

PURPOSE

Breast cancer is one of the leading causes of tumor death worldwide in female, and the five-year overall survival of breast cancer patients remains poor. It is an urgent need to seek novel target for its treatment. Synaptotagmin 13 (SYT13) is a synaptic vesicle transporting protein that regulates the malignant phenotypes of various cancers. However, its role in breast cancer is still unclear. The current study aimed to investigate the effects of SYT13 on the progression of breast cancer.

METHODS

Twenty-five pairs of breast cancer tissues and non-tumor tissues were obtained to assess the expression of SYT13. We manually modified the expression of SYT13 in MCF-7 and MDA-MB-231 cells. CCK-8 assay, EdU staining, and cell cycle analysis were carried out to measure the proliferated ability of cells. Annexin V/PI and TUNEL assays were used to detect the apoptotic ability of cells. Wound healing and transwell assays were employed to evaluate the migrated and invasive ability of breast cancer cells.

RESULTS

The results revealed that the mRNA and protein levels of SYT13 were higher in breast cancer tissues and cell lines. Knockdown of SYT13 inhibited the cell proliferation and induced cell cycle arrest in G1 phase of MCF-7 cells by downregulating cyclin D1 and CDK4, as well as upregulating p21. The migration and invasion of MCF-7 cells were repressed by the loss of SYT13 via the gain of E-cadherin and the loss of vimentin. Overexpression of SYT13 in MDA-MB-231 cells led to the opposite effects. Silencing of SYT13 induced the apoptosis ability of MCF-7 cells by the upregulation of bax and the downregulation of bcl-2. Moreover, we found that SYT13 depletion suppressed the FAK/AKT signaling pathway. PF573228 (a FAK inhibitor) and MK2206 (an AKT inhibitor) reversed the SYT13 overexpression-induced promotion of proliferation, migration, and invasion of MDA-MB-231 cells.

CONCLUSION

The results indicated that SYT13 promoted the malignant phenotypes of breast cancer cells by the activation of FAK/AKT signaling pathway.

Risk score for predicting death from other causes after curative gastrectomy for gastric cancer

BACKGROUND

The number of patients who die from causes other than gastric cancer after R0 resection is increasing in Japan, due in part to the aging population. However, few studies have comprehensively investigated the clinicopathological risks associated with deaths from other causes after gastrectomy. This study aimed to build a risk score for predicting such deaths.

METHODS

We retrospectively reviewed clinical data for 3575 patients who underwent gastrectomy for gastric cancer at nine institutions in Japan between January 2010 and December 2014.

RESULTS

The final study population of 1758 patients were assigned to Group A (n = 187): patients who died from other causes within 5 years of surgery, and Group B (n = 1571): patients who survived ≥ 5 years after surgery. Multivariate analysis identified nine characteristics as risk factors for poor survival: age ≥ 75 years, male sex, body mass index < 22 kg/m², Eastern Cooperative Oncology Group Performance Status (≥ 1), diabetes mellitus, cardiovascular/cerebrovascular disease, other malignant diseases, preoperative albumin level < 3.5 g/dL, and total gastrectomy. Patients with risk scores of 0-2, 3-4, or 5-9 (based on 1 point per characteristics) were classified into Low-risk, Intermediate-risk, and High-risk groups, respectively. The 5-year survival rates were 96.5%, 85.3%, and 56.5%, for the Low-, Intermediate-, and High-risk groups, respectively, and the hazard ratio (95% confidence intervals) was 16.33 (10.85-24.58, p < 0.001) for the High-risk group.

CONCLUSIONS

The risk score defined here may be useful for predicting deaths from other causes after curative gastrectomy.

A multi-institutional study to evaluate the feasibility of next-generation sequencing and genomic analysis using formalin-fixed, paraffin-embedded biopsies of gastric cancer

BACKGROUND

Formalin-fixed, paraffin-embedded (FFPE) samples acquired and preserved adequately are expected to faithfully maintain tumor characteristics. Endoscopic biopsy tissues represent an attractive resource for identifying predictive biomarkers to evaluate pretreatment responses of patients with advanced gastric cancer (GC). However, whether genomic profiles obtained through next-generation sequencing (NGS) using biopsy samples match well with those gained from surgical FFPE samples remains a concern.

METHODS

We collected 50 FFPE samples (26 biopsies and 24 surgical samples) from patients with GC who participated in phase III clinical trial JCOG1509. The quality and quantity of FFPE samples were determined for deep sequencing using NGS. We queried a 435-gene panel CANCERPLEX-JP to generate comprehensive genomic profiling data including the tumor mutation burden (TMB).

RESULTS

The median DNA yields and NGS success rates of biopsy samples compared with surgical samples were 879 ng and 80.8% vs 8523 ng and 100%, respectively. Epstein-Barr virus and microsatellite instability-high were detected in 9.5% of biopsy samples. Comparing the genomic profiles of 18 paired samples for which NGS data were available, we detected identical somatic mutations in paired biopsy and surgical samples (kappa coefficient, 0.8692). TMB positively correlated between paired biopsy and surgical samples (correlation coefficient, 0.6911).

CONCLUSIONS

NGS is applicable to the analysis of FFPE samples of GC acquired by the endoscopic biopsy, and the data were highly concordant with those obtained from surgical specimens of the same patients.

Gamma-aminobutyric Acid Type A Receptor Subunit Delta as a Potential Therapeutic Target in Gastric Cancer

BACKGROUND

Novel therapeutic targets are needed to improve the poor prognosis of patients with advanced gastric cancer. The aim of this study was to identify a novel therapeutic target for the treatment of GC and to investigate the potential therapeutic value of an antibody raised against the target.

METHODS

We identified gamma-aminobutyric acid type A receptor subunit delta as a candidate therapeutic target by differential transcriptome analysis of metastatic GC tissue and adjacent nontumor tissues. GABRD mRNA levels were analyzed in 230 pairs of gastric tissue by quantitative reverse-transcription polymerase chain reaction. GABRD function was assessed in proliferation, invasion, and apoptosis assays in human GC cell lines expressing control or GABRD-targeting small interfering RNA (siRNA). Mouse anti-human polyclonal GABRD antibodies were generated and assessed for inhibition of GC cell growth in vitro and in a mouse xenograft model of peritoneal GC dissemination.

RESULTS

High GABRD mRNA expression level in primary human GC tissue was associated with poor prognosis. Expression of siGABRD in GC cell lines significantly decreased cell proliferation and invasion and increased apoptosis compared with control siRNA expression. Anti-GABRD polyclonal antibodies inhibited GC cell proliferation in vitro and decreased peritoneal tumor nodule size in the mouse xenograft model.

CONCLUSION

We identified GABRD as novel regulator of GC cell growth and function. GABRD is upregulated in GC tissue and is associated with poor prognosis, suggesting that it may be a potential therapeutic target for GC.

Endothelial cell-specific molecule 1 drives cervical cancer progression

The expression, biological functions and underlying molecular mechanisms of endothelial cell-specific molecule 1 (ESM1) in human cervical cancer remain unclear. Bioinformatics analysis revealed that ESM1 expression was significantly elevated in human cervical cancer tissues, correlating with patients' poor prognosis. Moreover, ESM1 mRNA and protein upregulation was detected in local cervical cancer tissues and various cervical cancer cells. In established and primary cervical cancer cells, ESM1 shRNA or CRISPR/Cas9-induced ESM1 KO hindered cell proliferation, cell cycle progression, in vitro cell migration and invasion, and induced significant apoptosis. Whereas ESM1 overexpression by a lentiviral construct accelerated proliferation and migration of cervical cancer cells. Further bioinformatics studies and RNA sequencing data discovered that ESM1-assocaited differentially expressed genes (DEGs) were enriched in PI3K-Akt and epithelial-mesenchymal transition (EMT) cascades. Indeed, PI3K-Akt cascade and expression of EMT-promoting proteins were decreased after ESM1 silencing in cervical cancer cells, but increased following ESM1 overexpression. Further studies demonstrated that SYT13 (synaptotagmin 13) could be a primary target gene of ESM1. SYT13 silencing potently inhibited ESM1-overexpression-induced PI3K-Akt cascade activation and cervical cancer cell migration/invasion. In vivo, ESM1 knockout hindered SiHa cervical cancer xenograft growth in mice. In ESM1-knockout xenografts tissues, PI3K-Akt inhibition, EMT-promoting proteins downregulation and apoptosis activation were detected. In conclusion, overexpressed ESM1 is important for cervical cancer growth in vitro and in vivo, possibly by promoting PI3K-Akt activation and EMT progression. ESM1 represents as a promising diagnostic marker and potential therapeutic target of cervical cancer.

Potential roles of synaptotagmin family members in cancers: Recent advances and prospects

With the continuous development of bioinformatics and public database, more and more genes that play a role in cancers have been discovered. Synaptotagmins (SYTs) are abundant, evolutionarily conserved integral membrane proteins composed of a short N-terminus, a variable linker domain, a single transmembrane domain, and two C2 domains, and they constitute a family of 17 isoforms. The synaptotagmin family members are known to regulate calcium-dependent membrane fusion events. Some SYTs play roles in hormone secretion or neurotransmitter release or both, and much evidence supports SYTs as Ca²⁺ sensors of exocytosis. Since 5 years ago, an increasing number of studies have found that SYTs also played important roles in the occurrence and development of lung cancer, gastric cancer, colon cancer, and other cancers. Down-regulation of SYTs inhibited cell proliferation, migration, and invasion of cancer cells, but promoted cell apoptosis. Growth of peritoneal nodules is inhibited and survival is prolonged in mice administrated with siSYTs intraperitoneally. Therefore, most studies have found SYTs serve as an oncogene after overexpression and may become potential prognostic biomarkers for multiple cancers. This article provides an overview of recent studies that focus on SYT family members’ roles in cancers and highlights the advances that have been achieved.

Levels and Significance of Tumor Markers and Cytokines in Serum and Peritoneal Lavage Fluid of Patients with Peritoneal Metastasis of Gastric Cancer

The paper is written to investigate the levels and significance of tumor markers [carcinoembryonic antigen (CEA), carbohydrate antigen 125 (CA125), and carbohydrate antigen 19-9 (CA19-9)] and cytokines [interleukin-6 (IL-6), IL-4, and IL-2] in serum and peritoneal lavage fluid of patients with peritoneal metastasis of gastric cancer. For this research, 145 patients with gastric cancer treated in our hospital were divided into peritoneal metastasis group (n = 25), other metastasis group (n = 32), and nonmetastasis group (n = 88) according to the occurrence of metastasis. At the same time, the levels of serum tumor markers and cytokines and tumor markers and cytokines in intraoperative peritoneal lavage fluid were compared among the three groups. The results showed that the proportion of TNM stage III in peritoneal metastasis group and other metastasis group was 68.00% and 62.50%, respectively, and the proportion of tumor >5 cm was 64.00% and 59.38%, respectively, which was significantly higher than that in the control group. The 1-year survival rate of peritoneal metastasis group and other metastasis group was 44.00% and 40.63%, respectively, which was significantly lower than that of nonmetastasis group (P < 0.05).The serum levels of CEA, CA125, CA19-9, IL-6, IL-4, and IL-2 in peritoneal metastasis group and other metastasis group were higher than those in nonmetastasis group. The intraoperative peritoneal lavage fluid CEA, CA125, and IL-6 were 13.41 ± 3.72 ng/ml, 8.97 ± 1.33 U/ml, and 1.85 ± 0.44 pg/ml, respectively, which were higher than those in other metastasis groups and nonmetastasis groups (P < 0.05). There was no significant difference in the levels of CA19-9, IL-4, and IL-2 in peritoneal lavage fluid among peritoneal metastasis group, other metastasis groups, and nonmetastasis groups (P > 0.05); the areas under the ROC curve of intraoperative peritoneal lavage fluid CEA, CA125, and IL-6 in predicting peritoneal metastasis were 0.850, 0.902, and 0.806, respectively, P < 0.05. Thus, the conclusion is that peritoneal lavage fluid CEA, CA125, and IL-6 have certain application value in predicting and diagnosing peritoneal metastasis of gastric cancer, while the other indexes have no application value.

Lysosomal-associated membrane protein family member 5 promotes the metastatic potential of gastric cancer cells

BACKGROUND

Metastatic gastric cancer (GC) has a poor prognosis, and elucidating the molecular mechanisms involved in metastasis may lead to the development of novel therapeutic modalities.

METHODS

Transcriptome analysis of surgically resected metastatic tissue from GC patients and noncancerous tissue was performed to identify novel metastasis-related genes. Analyses of in vitro cell function, apoptosis, the cell cycle and cancer stemness were performed using GC cell lines with a stable knockout of a candidate gene. In vivo percutaneous, peritoneal dissemination and liver metastasis xenograft models were also generated. PCR array and proteome analyses were performed. Expression of the candidate gene was analyzed in GC tissues from 300 patients.

RESULTS

Lysosomal Associated Membrane Protein Family Member 5 (LAMP5) was upregulated in the metastatic tissues. LAMP5 knockout significantly suppressed proliferation, invasion, and migration of GC cells and increased apoptosis, cell cycle arrest and cancer stemness. LAMP5 knockout virtually suppressed tumor growth in in vivo percutaneous, peritoneal dissemination and liver metastasis models. EMT- and autophagy-related genes were associated with LAMP5. High LAMP5 mRNA levels were significantly associated with a worse prognosis.

CONCLUSION

LAMP5 plays a vital role in metastasis formation and may be a promising novel target of drug development for metastatic GC in the future.

Crosstalk between cancer-associated fibroblasts and immune cells in peritoneal metastasis: inhibition in the migration of M2 macrophages and mast cells by Tranilast

BACKGROUND

The role of tumor-stroma interactions in tumor immune microenvironment (TME) is attracting attention. We have previously reported that cancer-associated fibroblasts (CAFs) contribute to the progression of peritoneal metastasis (PM) in gastric cancer (GC), and M2 macrophages and mast cells also contribute to TME of PM. To elucidate the role of CAFs in TME, we established an immunocompetent mouse PM model with fibrosis, which reflects clinical features of TME. However, the involvement of CAFs in the immunosuppressive microenvironment remains unclear. In this study, we investigated the efficacy of Tranilast at modifying this immune tolerance by suppressing CAFs.

METHODS

The interaction between mouse myofibroblast cell line LmcMF and mouse GC cell line YTN16 on M2 macrophage migration was investigated, and the inhibitory effect of Tranilast was examined in vitro. Using C57BL/6J mouse PM model established using YTN16 with co-inoculation of LmcMF, TME of resected PM treated with or without Tranilast was analyzed by immunohistochemistry.

RESULTS

The addition of YTN16 cell-conditioned medium to LmcMF cells enhanced CXCL12 expression and stimulated M2 macrophage migration, whereas Tranilast inhibited the migration ability of M2 macrophages by suppressing CXCL12 secretion from LmcMF. In PM model, Tranilast inhibited tumor growth and fibrosis, M2 macrophage, and mast cell infiltration and significantly promoted CD8 + lymphocyte infiltration into the tumor, leading to apoptosis of cancer cells by an immune response.

CONCLUSION

Tranilast improved the immunosuppressive microenvironment by inhibiting CAF function in a mouse PM model. Tranilast is thus a promising candidate for the treatment of PM.

Synaptotagmin-13 Is a Neuroendocrine Marker in Brain, Intestine and Pancreas

Synaptotagmin-13 (Syt13) is an atypical member of the vesicle trafficking synaptotagmin protein family. The expression pattern and the biological function of this Ca²⁺-independent protein are not well resolved. Here, we have generated a novel Syt13-Venus fusion (Syt13-VF) fluorescence reporter allele to track and isolate tissues and cells expressing Syt13 protein. The reporter allele is regulated by endogenous cis-regulatory elements of Syt13 and the fusion protein follows an identical expression pattern of the endogenous Syt13 protein. The homozygous reporter mice are viable and fertile. We identify the expression of the Syt13-VF reporter in different regions of the brain with high expression in tyrosine hydroxylase (TH)-expressing and oxytocin-producing neuroendocrine cells. Moreover, Syt13-VF is highly restricted to all enteroendocrine cells in the adult intestine that can be traced in live imaging. Finally, Syt13-VF protein is expressed in the pancreatic endocrine lineage, allowing their specific isolation by flow sorting. These findings demonstrate high expression levels of Syt13 in the endocrine lineages in three major organs harboring these secretory cells. Collectively, the Syt13-VF reporter mouse line provides a unique and reliable tool to dissect the spatio-temporal expression pattern of Syt13 and enables isolation of Syt13-expressing cells that will aid in deciphering the molecular functions of this protein in the neuroendocrine system.

Synaptotagmin 13 Is Highly Expressed in Estrogen Receptor-Positive Breast Cancer

Background: Accumulating evidence indicates tumor-promoting roles of synaptotagmin 13 (SYT13) in several cancers; however, no studies have investigated its expression in breast cancer (BC). This study aimed to clarify the significance of SYT13 in BC. Methods: SYT13 mRNA expression levels were evaluated in BC cell lines. Polymerase chain reaction (PCR) array analysis was conducted to determine the correlation between expression levels of SYT13 and other tumor-associated genes. Then, the association of SYT13 expression levels in the clinical BC specimens with patients’ clinicopathological factors was evaluated. These findings were subsequently validated using The Cancer Genome Atlas (TCGA) database. Results: Among 13 BC cell lines, estrogen receptor (ER)-positive cells showed higher SYT13 mRNA levels than ER-negative cells. PCR array analysis revealed positive correlations between SYT13 and several oncogenes predominantly expressed in ER-positive BC, such as estrogen receptor 1, AKT serine/threonine kinase 1, and cyclin-dependent kinases 4. In 165 patients, ER-positive specimens exhibited higher SYT13 mRNA expression levels than ER-negative specimens. The TCGA database analysis confirmed that patients with ER-positive BC expressed higher SYT13 levels than ER-negative patients. Conclusion: This study suggests that SYT13 is highly expressed in ER-positive BC cells and clinical specimens, and there is a positive association of SYT13 with the ER signaling pathways.

Blockade of CHRNB2 signaling with a therapeutic monoclonal antibody attenuates the aggressiveness of gastric cancer cells

Here, we evaluated the therapeutic potential of antibodies (Abs) targeting cholinergic receptor nicotinic beta 2 subunit (CHRNB2) in gastric cancer. To investigate the effects of these Abs on malignant phenotypes in vitro and in mouse xenograft models, we generated gene knockouts through genome editing, performed RNA interference-mediated knockdown of gene expression, and ectopically expressed CHRNB2 in gastric cancer cells. The effects of anti-CHRNB2 Abs on the proliferation of cancer cells were evaluated both in vitro and in vivo. We determined the effects of Chrnb2 deficiency on mice and the clinical significance of CHRNB2 expression in gastric cancer clinical specimens. Knockdown of CHRNB2 attenuated gastric cancer cell proliferation, whereas forced overexpression of CHRNB2 increased cell proliferation. Knockout of CHRNB2 significantly influenced cell survival and functions associated with metastasis. The effects of polyclonal Abs targeting the C- and N-termini of CHRNB2 guided the development of anti-CHRNB2 monoclonal Abs that inhibited the growth of gastric cancer cells in vitro and in vivo. Pathway analysis revealed that CHRNB2 interfered with signaling through the PI3K-AKT and JAK-STAT pathways. Chrnb2-deficient mice exhibited normal reproduction, organ functions, and motor functions. CHRNB2 regulates multiple oncological phenotypes associated with metastasis, and blockade of CHRNB2 expression using specific Abs shows promise for controlling metastasis in gastric cancer.

A seven-gene prognostic model related to immune checkpoint PD-1 revealing overall survival in patients with lung adenocarcinoma

BACKGROUND

We aimed to identify the immune checkpoint Programmed cell death 1 (PD-1)-related gene signatures to predict the overall survival of lung adenocarcinoma (LUAD).

METHODS

RNA-seq datasets associated with LUAD as well as clinical information were downloaded from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Based on the expression level of PD-1, Kaplan-Meier (K-M) survival analysis was performed to divide samples into PD-1 high- and low- expression groups. Then, differentially expressed genes (DEGs) between high- and low- expression groups were identified. Meanwhile, samples were divided into the high and low immune infiltration groups according to score of immune cell, followed by screening of DEGs between these two groups. Subsequently, DEGs related to both PD-1 expression and immune infiltration was integrated to obtain the overlapping genes. Lasso COX regressions were implemented to construct prognostic signatures. The prognostic model was validated using an independent GEO dataset and TCGA cohorts. In addition, the predictive ability of the seven-gene prognostic model with other molecular biomarkers was compared.

RESULTS

A seven-gene signature (DPT, ITGAD, CLECL1, SYT13, DUSP26, AMPD1, and NELL2) related to PD-1 was developed through Lasso Cox regression. Univariate and multivariate regression analyses indicated that the constructed risk model was an independent prognostic factor. K-M survival analysis indicated that patients in the high risk group had significantly worse prognosis than those in the low risk group. Further, the results of validation analysis showed that this model was reliable and effective.

CONCLUSIONS

The constructed prognostic model can predict overall survival in LUAD patients with great predictive performance, and it may be applied for diagnosis and adjuvant treatment of LUAD in clinical trials.