Atlas of metastatic gastric cancer links ferroptosis to disease progression and immunotherapy response.

BACKGROUND & AIMS: Metastases from gastric adenocarcinoma (GAC) lead to high morbidity and mortality. Developing innovative and effective therapies requires a comprehensive understanding of the tumor and immune biology of advanced GAC. Yet, collecting matched specimens from advanced, treatment-naïve GAC patients poses a significant challenge, limiting the scope of current research, which has predominantly focused on localized tumors. This gap hinders a deeper insight into the metastatic dynamics of GAC. METHODS: We performed in-depth single-cell transcriptome and immune profiling on 68 paired, treatment-naïve, primary-metastatic tumors to delineate alterations in cancer cells and their tumor microenvironment (TME) during metastatic progression. To validate our observations, we conducted comprehensive functional studies both in vitro and in vivo, employing cell lines, multiple PDX and novel mouse models of GAC. RESULTS: Liver and peritoneal metastases exhibited distinct properties in cancer cells and dynamics of TME phenotypes, supporting the notion that cancer cells and their local TMEs co-evolve at metastatic sites. Our study also revealed differential activation of cancer meta-programs across metastases. We observed evasion of cancer cell ferroptosis via GPX4 upregulation during GAC progression. Conditional depletion of Gpx4 or pharmacological inhibition of ferroptosis resistance significantly attenuated tumor growth and metastatic progression. Additionally, ferroptosis-resensitizing treatments augmented the efficacy of CAR T-cell therapy. CONCLUSIONS: This study represents the largest single-cell dataset of metastatic GACs to date. High-resolution mapping of the molecular and cellular dynamics of GAC metastasis has revealed a rationale for targeting ferroptosis defense in combination with CAR T-cell therapy as a novel therapeutic strategy with potential immense clinical implications.

Epithelial SOX9 drives progression and metastases of gastric adenocarcinoma by promoting immunosuppressive tumour microenvironment.

OBJECTIVE: Many cancers engage embryonic genes for rapid growth and evading the immune system. SOX9 has been upregulated in many tumours, yet the role of SOX9 in mediating immunosuppressive tumour microenvironment is unclear. Here, we aim to dissect the role of SOX9-mediated cancer stemness attributes and immunosuppressive microenvironment in advanced gastric adenocarcinoma (GAC) for novel therapeutic discoveries. METHODS: Bulk RNAseq/scRNA-seq, patient-derived cells/models and extensive functional studies were used to identify the expression and functions of SOX9 and its target genes in vitro and in vivo. Immune responses were studied in PBMCs or CD45+ immune cells cocultured with tumour cells with SOX9high or knockout and the KP-Luc2 syngeneic models were used for efficacy of combinations. RESULTS: SOX9 is one of the most upregulated SOX genes in GAC and highly expressed in primary and metastatic tissues and associated with poor prognosis. Depletion of SOX9 in patient-derived GAC cells significantly decreased cancer stemness attributes, tumour formation and metastases and consistently increased CD8+ T cell responses when cocultured with PBMCs/CD45+ cells from GAC patients. RNA sequencing identified the leukaemia inhibitory factor (LIF) as the top secreted molecule regulated by SOX9 in tumour cells and was enriched in malignant ascites and mediated SOX9-induced M2 macrophage repolarisation and inhibited T cell function. CONCLUSION: Epithelial SOX9 is critical in suppressing CD8+ T cell responses and modified macrophage function in GAC through the paracrine LIF factor. Cotargeting LIF/LIFR and CSF1R has great potential in targeting SOX9-mediated cancer stemness, T cell immunosuppression and metastases suggesting the novel combination therapy against advanced GAC.

Localized Gastroesophageal Adenocarcinoma in the Elderly: Is Age a Factor Associated with Suboptimal Treatment?

INTRODUCTION: Gastroesophageal adenocarcinoma is relatively common in elderly patients as the incidence increases with age. However, the optimal treatment approach is not well established in this group of patients. The aim of this study is to review our experience for localized gastroesophageal adenocarcinoma in patients aged ≥80 years and to assess association between patient characteristics, clinical factors, and overall survival (OS) in order to optimize the therapeutic approaches for this population. METHODS: Patients ≥80 years old treated for localized gastroesophageal adenocarcinoma were retrospectively analyzed. Survival curves were estimated using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards regression models were applied to assess the association between patient characteristics and OS. Factors that were significant in the multivariate model were included in the final reduced model. RESULTS: 127 patients ≥80 years old, were included in this study with median age of 83 years. The median follow-up time was 3.2 years, and median OS was 2.5 years (95% CI: 2.0-3.1 years). Independent prognostic factors for OS were Eastern Cooperative Oncology Group (ECOG) performance status (PS) (p = 0.003), baseline clinical stage (p = 0.01), and surgery (p = 0.001). ECOG PS, tumor location, baseline stage, tumor grade, and surgery were included in the final reduced model. CONCLUSION: Surgical treatment can improve survival in elderly patients. Therapeutic decisions should be based on the patients' general condition rather that age alone.

Targeting cancer stem cells with a pan-BCL-2 inhibitor in preclinical and clinical settings in patients with gastroesophageal carcinoma.

OBJECTIVE: Gastro-oesophageal cancers (GEC) are resistant to therapy and lead to poor prognosis. The cancer stem cells (CSCs) and antiapoptotic pathways often confer therapy resistance. We sought to elucidate the antitumour action of a BCL-2 inhibitor, AT101 in GEC in vitro, in vivo and in a clinical trial. METHODS: Extensive preclinical studies in vitro and in vivo were carried out to establish the mechanism action of AT101 on targeting CSCs and antiapoptotic proteins. A pilot clinical trial in patients with GEC was completed with AT-101 added to standard chemoradiation. RESULTS: Overexpression of BCL-2 and MCL-1 was noted in gastric cancer tissues (GC). AT-101 induced apoptosis, reduced proliferation and tumour sphere formation in MCL-1/BCL-2 high GC cells. Interestingly, AT101 dramatically downregulated genes (YAP-1/Sox9) that control CSCs in GEC cell lines regardless of BCL-2/MCL-1 expression. Addition of docetaxel to AT-101 amplified its antiproliferation and induced apoptosis effects. In vivo studies confirmed the combination of AT101 and docetaxel demonstrated stronger antitumour activity accompanied with significant decrease of CSCs biomarkers (YAP1/SOX9). In a pilot clinical trial, 13 patients with oesophageal cancer (EC) received AT101 orally concurrently with chemoradiation. We observed dramatic clinical complete responses and encouraging overall survival in these patients. Clinical specimen analyses revealed that AT-101 dramatically reduced the expression of CSCs genes in treated EC specimens indicating antitumour activity of AT101 relies more on its anti-CSCs activity. CONCLUSIONS: Our preclinical and clinical data suggest that AT-101 overcomes resistance by targeting CSCs pathways suggesting a novel mechanism of action of AT101 in patients with GEC.

YAP1 mediates gastric adenocarcinoma peritoneal metastases that are attenuated by YAP1 inhibition.

OBJECTIVE: Peritoneal carcinomatosis (PC; malignant ascites or implants) occurs in approximately 45% of advanced gastric adenocarcinoma (GAC) patients and associated with a poor survival. The molecular events leading to PC are unknown. The yes-associated protein 1 (YAP1) oncogene has emerged in many tumour types, but its clinical significance in PC is unclear. Here, we investigated the role of YAP1 in PC and its potential as a therapeutic target. METHODS: Patient-derived PC cells, patient-derived xenograft (PDX) and patient-derived orthotopic (PDO) models were used to study the function of YAP1 in vitro and in vivo. Immunofluorescence and immunohistochemical staining, RNA sequencing (RNA-Seq) and single-cell RNA-Seq (sc-RNA-Seq) were used to elucidate the expression of YAP1 and PC cell heterogeneity. LentiCRISPR/Cas9 knockout of YAP1 and a YAP1 inhibitor were used to dissect its role in PC metastases. RESULTS: YAP1 was highly upregulated in PC tumour cells, conferred cancer stem cell (CSC) properties and appeared to be a metastatic driver. Dual staining of YAP1/EpCAM and sc-RNA-Seq revealed that PC tumour cells were highly heterogeneous, YAP1high PC cells had CSC-like properties and easily formed PDX/PDO tumours but also formed PC in mice, while genetic knockout YAP1 significantly slowed tumour growth and eliminated PC in PDO model. Additionally, pharmacologic inhibition of YAP1 specifically reduced CSC-like properties and suppressed tumour growth in YAP1high PC cells especially in combination with cytotoxics in vivo PDX model. CONCLUSIONS: YAP1 is essential for PC that is attenuated by YAP1 inhibition. Our data provide a strong rationale to target YAP1 in clinic for GAC patients with PC.

Integrated genomic profiling and modelling for risk stratification in patients with advanced oesophagogastric adenocarcinoma.

OBJECTIVE: Prognosis of patients with advanced oesophagogastric adenocarcinoma (mEGAC) is poor and molecular determinants of shorter or longer overall survivors are lacking. Our objective was to identify molecular features and develop a prognostic model by profiling the genomic features of patients with mEGAC with widely varying outcomes. DESIGN: We profiled 40 untreated mEGACs (20 shorter survivors <13 months and 20 longer survivors >36 months) with whole-exome sequencing (WES) and RNA sequencing and performed an integrated analysis of exome, transcriptome, immune profile and pathological phenotypes to identify the molecular determinants, developing an integrated model for prognosis and comparison with The Cancer Genome Atlas (TCGA) cohorts. RESULTS: KMT2C alterations were exclusively observed in shorter survivors together with high level of intratumour heterogeneity and complex clonal architectures, whereas the APOBEC mutational signatures were significantly enriched in longer survivors. Notably, the loss of heterozygosity in chromosome 4 (Chr4) was associated with shorter survival and 'cold' immune phenotype characterised by decreased B, CD8, natural killer cells and interferon-gamma responses. Unsupervised transcriptomic clustering revealed a shorter survivor subtype with distinct expression features (eg, upregulated druggable targets JAK2, MAP3K13 and MECOM). An integrated model was then built based on clinical variables and the identified molecular determinants, which significantly segregated shorter and longer survivors. All the above features and the integrated model have been validated independently in multiple TCGA cohorts. CONCLUSION: This study discovered novel molecular features prognosticating overall survival in patients with mEGAC and identified potential novel targets in shorter survivors.

Frequency and Implications of Paratracheal Lymph Node Metastases in Resectable Esophageal or Gastroesophageal Junction Adenocarcinoma.

OBJECTIVE: We aimed to evaluate the frequency of paratracheal lymph nodes (LN) metastases and their prognostic influence. SUMMARY BACKGROUND DATA: Paratracheal LNs are considered regional nodes in the esophageal cancer classification, but their metastatic rate and influence on survival remain unclear. METHODS: One thousand one hundred ninety-nine patients with resectable esophageal or gastroesophageal junction adenocarcinoma (EAC) (January 2002 and December 2016) in our Gastrointestinal Medical Oncology Database were analyzed. Paratracheal LNs were defined as1R, 1L, 2R, 2L, 4R, and 4L, according to the 8th American Joint Committee on Cancer classification. RESULTS: Of 1199 patients, 73 (6.1%) had positive paratracheal LNs at diagnosis. The median overall survival (OS) of 73 patients with initial paratracheal LN involvement was 2.10 years (range 0.01-10.1, 5-yrs OS 24.2%). Of 1071 patients who were eligible for recurrence evaluation, 70 patients (6.5%) developed paratracheal LN metastases as the first recurrence. The median time to recurrence was 1.28 years (range 0.28-5.96 yrs) and the median OS following recurrence was only 0.95 year (range 0.03-7.88). OS in 35 patients who had only paratracheal LN recurrence was significantly longer than in patients who had other recurrences (median OS 2.26 vs 0.51 yrs, 5-yrs OS; 26.8% vs 0%, P < 0.0001). Higher T stage (T3/T4) was an independently risk factor for paratracheal LN recurrence (odds ratio 5.10, 95% confidence interval 1.46-17.89). We segregated patients in 3 groups based on the distance of tumor's proximal edge to esophagogastric junction (low; ≤2 cm, medium; 2.0-7.0 cm, and high; >7.0 cm). Paratracheal LN metastases were more frequent with the proximal tumors (low, 4.2%; medium, 12.0%; high, 30.3%; Cochran-Armitage Trend test, P < 0.001). CONCLUSION: Paratracheal LN metastases were associated with a shorter survival in resectable EAC patients. Alternate approaches to prolong survival of this group of patients are warranted.

Multiplex profiling of peritoneal metastases from gastric adenocarcinoma identified novel targets and molecular subtypes that predict treatment response.

OBJECTIVE: Peritoneal carcinomatosis (PC) occurs frequently in patients with gastric adenocarcinoma (GAC) and confers a poor prognosis. Multiplex profiling of primary GACs has been insightful but the underpinnings of PC's development/progression remain largely unknown. We characterised exome/transcriptome/immune landscapes of PC cells from patients with GAC aiming to identify novel therapeutic targets. DESIGN: We performed whole-exome sequencing (WES) and whole transcriptome sequencing (RNA-seq) on 44 PC specimens (43 patients with PC) including an integrative analysis of WES, RNA-seq, immune profile, clinical and pathological phenotypes to dissect the molecular pathogenesis, identifying actionable targets and/or biomarkers and comparison with TCGA primary GACs. RESULTS: We identified distinct alterations in PC versus primary GACs, such as more frequent CDH1 and TAF1 mutations, 6q loss and chr19 gain. Alterations associated with aggressive PC phenotypes emerged with increased mutations in TP53, CDH1, TAF1 and KMT2C, higher level of 'clock-like' mutational signature, increase in whole-genome doublings, chromosomal instability (particularly, copy number losses), reprogrammed microenvironment, enriched cell cycle pathways, MYC activation and impaired immune response. Integrated analysis identified two main molecular subtypes: 'mesenchymal-like' and 'epithelial-like' with discriminating response to chemotherapy (31% vs 71%). Patients with the less responsive 'mesenchymal-like' subtype had high expression of immune checkpoint T-Cell Immunoglobulin And Mucin Domain-Containing Protein 3 (TIM-3), its ligand galectin-9, V-domain Ig suppressor of T cell activation (VISTA) and transforming growth factor-ß as potential therapeutic immune targets. CONCLUSIONS: We have uncovered the unique mutational landscape, copy number alteration and gene expression profile of PC cells and defined PC molecular subtypes, which correlated with PC therapy resistance/response. Novel targets and immune checkpoint proteins have been identified with a potential to be translated into clinics.

Total Lesion Glycolysis Assessment Identifies a Patient Fraction With a High Cure Rate Among Esophageal Adenocarcinoma Patients Treated With Definitive Chemoradiation.

OBJECTIVE: We aimed to determine whether tumor metabolism could be prognostic of cure in L-EAC patients who receive definitive chemoradiation. SUMMARY BACKGROUND DATA: Patients with inoperable localized esophageal adenocarcinoma (L-EAC) often receive definitive chemoradiation; however, biomarkers and/or imaging variables to prognosticate cure are missing. METHODS: Two hundred sixty-six patients with L-EAC who had chemoradiation but not surgery were analyzed from the prospectively maintained EAC databases in the Department of Gastrointestinal Medical Oncology at The University of Texas MD Anderson Cancer Center (Texas, USA) between March 2002 and April 2015. Maximum standardized uptake value (SUVmax) and total lesion glycolysis (TLG) from the positron emission tomography data were evaluated. RESULTS: Of 266 patients, 253 (95%) were men; the median age was 67 years (range 20-91 yrs) and 153 had poorly differentiated L-EAC. The median SUVmax was 10.3 (range 0-87) and the median TLG was 85.7 (range 0-3227). Both SUVmax and TLG were higher among those with: tumors >5 cm in length, high clinical stage, and high tumor and node categories by TNM staging (all P < 0.0001). Of 234 patients evaluable for cure, 60 (25.6%) achieved cure. In the multivariable logistic regression model, low TLG (but not low SUVmax) was associated with cure (continuous TLG value: odds ratio 0.70, 95% confidence interval (CI) 0.54-0.92). TLG was quantified into 4 quartile categorical variables; first quartile (Q1; <32), second quartile (Q2; 32.0-85.6), third quartile (Q3; 85.6-228.4), and fourth quartile (Q4; >228.4); the cure rate was only 10.3% in Q4 and 5.1% in Q3 but increased to 28.8% in Q2, and 58.6% in Q1. The cross-validation resulted in an average accuracy of prediction score of 0.81 (95% CI, 0.75-0.86). CONCLUSIONS: In this cross-validated model, 59% of patients in the 1st quartile were cured following definitive chemoradiation. Baseline TLG could be pursued as one of the tools for esophageal preservation.

Brain metastases in patients with upper gastrointestinal cancer is associated with proximally located adenocarcinoma and lymph node metastases.

BACKGROUND: As cancer patients are surviving longer, more patients manifest brain metastases (BRMs). However, the rate of BRMs from upper gastrointestinal cancer is unclear. We therefore evaluated the frequency and prognostic effect of BRMs in this setting. METHODS: We analyzed records of 2348 patients who were treated between January 2002 and December 2016 for upper gastrointestinal cancer, including esophageal and gastroesophageal junction adenocarcinoma (EAC; proximal EAC, Siewert types I and II), esophageal squamous cell carcinoma (ESCC), and gastric adenocarcinoma (GAC; Siewert type III and stomach cancer) in our Gastrointestinal Medical Oncology Database. Frequency, risk factors, and survival after BRMs were evaluated. RESULTS: Of 2348 patients, 68 (2.9%) had BRMs upon follow-up. The BRM rates were as follows: proximal EAC, 4.8%; Siewert type I, 5.9%; Siewert type II, 2.2%; Siewert type III, 0.7%; ESCC: 1.2%; and stomach cancer, 0%. Among EAC patients, Siewert type I and lymph node metastases were independent the risk factors for BRMs in the multivariable analysis. The median overall survival (OS) in the 68 patients with BRMs was only 1.16 years (95% CI 0.78-1.61). However, OS for patients who had a solitary BRM, who had BRM but no other distant metastasis, or who underwent surgery or stereotactic radiosurgery favorable. CONCLUSION: Patients with proximally located adenocarcinoma, or with lymph node metastases are at a higher risk for BRMs and patients fare better after treatment of isolated BRM.

Low metabolic activity in primary gastric adenocarcinoma is associated with resistance to chemoradiation and the presence of signet ring cells.

PURPOSES: Preoperative chemoradiation is a potential treatment option for localized gastric adenocarcinoma (GAC). Currently, the response to chemoradiation cannot be predicted. We analyzed the pretreatment maximum standardized uptake value (SUVmax) and total lesion glycolysis (TLG) on positron emission tomography/computed tomography as potential predictors of the response to chemoradiation. METHODS: We analyzed the SUVmax and TLG data from 59 GAC patients who received preoperative chemoradiation. We used logistic regression models to predict a pathologic complete response (pCR) and Kaplan-Meier curves to determine overall survival among patients with high and low SUVmax or TLG. RESULTS: Twenty-nine patients (49%) had Siewert type III adenocarcinoma and 30 (51%) had tumors located in the lower stomach. Forty-one patients had poorly differentiated GAC, and 26 had signet ring cells. The median SUVmax was 7.3 (0-28.2) and the median TLG was 56.6 (0-1881.5). Patients with signet ring cells had a low pCR rate, as well as a low SUVmax and TLG. In the multivariable logistic regression model, high SUVmax was a predictor of pCR (odds ratio = 11.1, 95% confidence interval = 2.12-50.0, p = 0.004). Overall survival was not associated with the SUVmax (log-rank p = 0.69) or TLG (log-rank p = 0.85) CONCLUSION: A high SUVmax was associated with sensitivity to chemoradiation and pCR in GAC, and signet ring cells seemed to confer resistance.

Ramucirumab and Paclitaxel Administered Every 2 Weeks (mRAINBOW Regimen) in Advanced Gastroesophageal Adenocarcinoma.

BACKGROUND: The RAINBOW trial established ramucirumab combined with paclitaxel as a second-line option in metastatic gastric and gastroesophageal junction (GEJ) adenocarcinoma. Ramucirumab was given on days 1 and 15 with paclitaxel on days 1, 8, and 15 of a 28-day cycle. The median overall survival (OS) was significantly longer with ramuciru-mab plus paclitaxel (p = 0.017), and it led to 41% grade 3 or higher neutropenia. We review our experience with both ramucirumab plus paclitaxel given biweekly (mRAINBOW) to assess efficacy and safety. OBJECTIVES: The primary objective was to assess OS. Secondary end points were progression-free survival (PFS), overall response, and safety. METHODS: We identified 129 patients retrospectively from our database between November 2014 and May 2017. Patients were included if they were followed up at our institution. RESULTS: Median doses given were ramucirumab 8 mg/kg i.v. plus paclitaxel 110 mg/m2 i.v. given once every 2 weeks. The median performance status was 1, and ∼60% had poorly differentiated histology; 55.8% had progression in < 6 months on first-line therapy, and the majority had measurable cancer. Median overall OS and PFS for the entire cohort was 9.4 months (95% CI: 8.05-10.74) and 3.68 months (95% CI: 2.73-4.5), respectively. Median OS was 9.46 months (95% CI: 8.05-14.95) and median PFS was 4.14 months (95% CI: 2.96-5.29) in those patients that received ramucirumab plus paclitaxel in the second-line setting. CONCLUSION: Biweekly administration of ramucirumab plus paclitaxel did not compromise efficacy. Delays, adjustments, or doses held were similar to the RAINBOW trial, with 31% requiring a dose or schedule modification.

Retrospective Study of Claudin 18 Isoform 2 Prevalence and Prognostic Association in Gastric and Gastroesophageal Junction Adenocarcinoma.

PURPOSE: Claudin 18 isoform 2 (CLDN18.2) is an emerging biomarker and therapeutic target in gastric and gastroesophageal junction (G/GEJ) adenocarcinoma. This study aimed to obtain deeper understanding of CLDN18.2 positivity patterns, prognostic implications, and associations with various demographic, clinical, and molecular characteristics in G/GEJ adenocarcinoma. METHODS: Archived tumor tissue samples from 304 patients with G/GEJ adenocarcinoma in the United States were assessed for CLDN18.2 positivity by immunohistochemistry. CLDN18.2 positivity was defined as ≥50% or ≥75% of tumor cells with CLDN18 staining intensity ≥2+. CLDN18.2 positivity patterns were analyzed for association with prognosis and clinicopathologic/demographic characteristics. Where possible, CLDN18.2 positivity was analyzed for matched tissue samples to assess concordance between primary and metastatic tumors and concordance before and after chemotherapy. RESULTS: The overall prevalence of CLDN18.2-positive tumors (with ≥75% cutoff) was 44.4% (n = 135 of 304). CLDN18.2-positive tumors had a prevalence of 51.4% (n = 91 of 177) in gastric and 34.6% (n = 44 of 127) in GEJ adenocarcinoma. With a ≥50% cutoff, the prevalence of CLDN18.2-positive tumors was 64.4% (n = 114 of 177) in gastric adenocarcinoma and 44.9% (n = 57 of 127) in GEJ adenocarcinoma. There was no association between overall survival and CLDN18.2 positivity using either threshold. Statistically significant associations were noted between CLDN18.2 positivity and sex, histologic type of G/GEJ adenocarcinoma, and adenocarcinoma subtype (≥75% cutoff), and metastasis site and tumor grade (≥50% cutoff). The overall concordance of CLDN18.2 positivity (≥75% cutoff) was 73% (27 of 37) for matched primary versus metastatic tumor samples and 74% (29 of 39) for matched samples before and after chemotherapy. CONCLUSION: This study demonstrated that CLDN18.2 positivity did not correlate with survival in G/GEJ adenocarcinoma, consistent with published data. On the basis of matched sample analysis, CLDN18.2 appears to demonstrate >70% concordance as a biomarker. Observed correlations with certain patient/tumor characteristics warrant further study.

Proteogenomic landscape of gastric adenocarcinoma peritoneal metastases.

Advanced gastric adenocarcinoma (GAC) often leads to peritoneal carcinomatosis (PC) and is associated with very poor outcome. Here we report the comprehensive proteogenomic study of ascites derived cells from a prospective GAC cohort (n = 26 patients with peritoneal carcinomatosis, PC). A total of 16,449 proteins were detected from whole cell extracts (TCEs). Unsupervised hierarchical clustering resulted in three distinct groups that reflected extent of enrichment in tumor cells. Integrated analysis revealed enriched biological pathways and notably, some druggable targets (cancer-testis antigens, kinases, and receptors) that could be exploited to develop effective therapies and/or tumor stratifications. Systematic comparison of expression levels of proteins and mRNAs revealed special expression patterns of key therapeutics target notably high mRNA and low protein expression of HAVCR2 (TIM-3), and low mRNA but high protein expression of cancer-testis antigens CTAGE1 and CTNNA2. These results inform strategies to target GAC vulnerabilities.

Evolution of immune and stromal cell states and ecotypes during gastric adenocarcinoma progression.

Understanding tumor microenvironment (TME) reprogramming in gastric adenocarcinoma (GAC) progression may uncover novel therapeutic targets. Here, we performed single-cell profiling of precancerous lesions, localized and metastatic GACs, identifying alterations in TME cell states and compositions as GAC progresses. Abundant IgA+ plasma cells exist in the premalignant microenvironment, whereas immunosuppressive myeloid and stromal subsets dominate late-stage GACs. We identified six TME ecotypes (EC1-6). EC1 is exclusive to blood, while EC4, EC5, and EC2 are highly enriched in uninvolved tissues, premalignant lesions, and metastases, respectively. EC3 and EC6, two distinct ecotypes in primary GACs, associate with histopathological and genomic characteristics, and survival outcomes. Extensive stromal remodeling occurs in GAC progression. High SDC2 expression in cancer-associated fibroblasts (CAFs) is linked to aggressive phenotypes and poor survival, and SDC2 overexpression in CAFs contributes to tumor growth. Our study provides a high-resolution GAC TME atlas and underscores potential targets for further investigation.

Teledentistry and Online Referral System in Indonesian Primary Health Care Center During the COVID-19 Pandemic: A Narrative Review.

Aims: This review aims to map the needs and challenges in the application of teledentistry and online referral system encountered by dental health care professionals in Indonesian primary health care centers (puskesmas) to provide safe dental health service to the population during the COVID-19 pandemic. Materials and Methods: Literature search was undertaken of both in Indonesian and overseas context related to teledentistry. Narrative review of the literature was written to present the challenges, solutions, and application of teledentistry at Puskesmas to optimize oral health services during the COVID-19 pandemic. Results: Online referral system and teledentistry are options to help dental health service delivery in the pandemic era. While it has been adopted in many private clinics, there are many challenges to adopt it at the puskesmas level due to a lack of infrastructure, human resources, and budget allocation. While the Indonesian government has plans to support the digitization in the education and health sector, this pandemic shall pose an opportunity for Indonesian health department to develop and facilitate the use of teledentistry and online referral system. During this situation, health cadres can bridge the relationship between Puskesmas and the poor community through the help of teledentistry. Conclusions: The government commitment in applying online referral system and teledentistry in Puskesmas is needed. Dental education institutions can help to supply human resources, who are capable of developing and carrying out the most suitable teledentistry application for all stakeholders.

GRK3 is a poor prognosticator and serves as a therapeutic target in advanced gastric adenocarcinoma.

BACKGROUND: G protein-coupled receptor (GPCR) is the most targeted protein family by the FDA-approved drugs. GPCR-kinase 3 (GRK3) is critical for GPCR signaling. Our genomic analysis showed that GRK3 expression correlated with poor prognosis of gastric adenocarcinoma (GAC) patients. However, GRK3's functions and clinical utility in GAC progression and metastases are unknown. METHODS: We studied GRK3 expression in normal, primary, and metastatic GAC tissues. We identified a novel GRK3 inhibitor, LD2, through a chemical-library screen. Through genetic and pharmacologic modulations of GRK3, a series of functional and molecular studies were performed in vitro and in vivo. Impact of GRK3 on YAP1 and its targets was determined. RESULTS: GRK3 was overexpressed in GAC tissues compared to normal and was even higher in peritoneal metastases. Overexpression (OE) of GRK3 was significantly associated with shorter survival. Upregulation of GRK3 in GAC cells increased cell invasion, colony formation, and proportion of ALDH1+ cells, while its downregulation reduced these attributes. Further, LD2 potently and specifically inhibited GRK3, but not GRK2, a very similar kinase to GRK3. LD2 highly suppressed GAC cells' malignant phenotypes in vitro. Mechanistically, GRK3 upregulated YAP1 in GAC tissues and its transcriptional downstream targets: SOX9, Birc5, Cyr61 and CTGF. Knockdown (KD) YAP1 rescued the phenotypes of GRK3 OE in GAC cells. GRK3 OE significantly increased tumor growth but LD2 inhibited tumor growth in the PDX model and dramatically suppressed peritoneal metastases induced by GRK3 OE. CONCLUSIONS: GRK3, a poor prognosticator for survival, conferred aggressive phenotype. Genetic silencing of GRK3 or its inhibitor LD2 blunted GRK3-conferred malignant attributes, suggesting GRK3 as a novel therapeutic target in advanced GAC.

National sample surveys show poor households face catastrophic expenditure for oral healthcare services in India.

INTRODUCTION: Globally people pay out-of-pocket (OOP) to access Oral healthcare services. In India, there is limited evidence on estimates of OOP expenditure. We undertook an analysis of national sample survey data on household health care expenditure to understand the expenditure pattern for Oral healthcare services and the catastrophic burden. METHOD: The expenditure reported for Oral healthcare services from two surveys: 71st round and 75th round, published by National Sample Survey Office (NSSO) was extracted. Based on monthly household consumption expenditure three economic groups were made: poor, middle- and rich-income groups. The OOP expenditure pattern while accessing day-care services and hospitalization and in public and private sector and the catastrophic expenditure were analysed. RESULTS: A total of 204 and 155 households from two national surveys reported to have accessed day-care Oral services respectively. The median OOP expenditure in public sector remained same at US $ 4 in both surveys. Over 35% of 78 households in 71st round and 42% of 167 in 75th round used public sector hospitalization services. The median expenditure of hospitalization doubled from US$ 58 (IQR 21-263) in 71st round to US $ 125 (IQR 45-363) in 75th round. Households from poor income groups spent seven times more for Oral healthcare services during the recent survey and faced catastrophic expenditure. CONCLUSION: The OOP expenditure for Oral healthcare has significant catastrophic household expenditure among the poor. There is a need to increase investment in public sector and insurance to protect poor against hospitalization expenditure in private sector.

Patient-derived cell lines and orthotopic mouse model of peritoneal carcinomatosis recapitulate molecular and phenotypic features of human gastric adenocarcinoma.

BACKGROUND: Gastric adenocarcinoma with peritoneal carcinomatosis (PC) is therapy resistant and leads to poor survival. To study PC in depth, there is an urgent need to develop representative PC-derived cell lines and metastatic models to study molecular mechanisms of PC and for preclinical screening of new therapies. METHODS: PC cell lines were developed from patient-derived PC cells. The tumorigenicity and metastatic potential were investigated by subcutaneously (PDXs) and orthotopically. Karyotyping, whole-exome sequencing, RNA-sequencing, and functional studies were performed to molecularly define the cell lines and compare genomic and phenotypic features of PDX and donor PC cells. RESULTS: We established three PC cell lines (GA0518, GA0804, and GA0825) and characterized them in vitro. The doubling times were 22, 39, and 37 h for GA0518, GA0804, and GA0825, respectively. Expression of cancer stem cell markers (CD44, ALDH1, CD133 and YAP1) and activation of oncogenes varied among the cell lines. All three PC cell lines formed PDXs. Interestingly, all three PC cell lines formed tumors in the patient derived orthotopic (PDO) model and GA0518 cell line consistently produced PC in mice. Moreover, PDXs recapitulated transcriptomic and phenotypic features of the donor PC cells. Finally, these cell lines were suitable for preclinical testing of chemotherapy and target agents in vitro and in vivo. CONCLUSION: We successfully established three patient-derived PC cell lines and an improved PDO model with high incidence of PC associated with malignant ascites. Thus, these cell lines and metastatic PDO model represent excellent resources for exploring metastatic mechanisms of PC in depth and for target drug screening and validation by interrogating GAC for translational studies.