Human Innate Lymphoid Cell Subsets Possess Tissue-Type Based Heterogeneity in Phenotype and Frequency.

Animal models have highlighted the importance of innate lymphoid cells (ILCs) in multiple immune responses. However, technical limitations have hampered adequate characterization of ILCs in humans. Here, we used mass cytometry including a broad range of surface markers and transcription factors to accurately identify and profile ILCs across healthy and inflamed tissue types. High dimensional analysis allowed for clear phenotypic delineation of ILC2 and ILC3 subsets. We were not able to detect ILC1 cells in any of the tissues assessed, however, we identified intra-epithelial (ie)ILC1-like cells that represent a broader category of NK cells in mucosal and non-mucosal pathological tissues. In addition, we have revealed the expression of phenotypic molecules that have not been previously described for ILCs. Our analysis shows that human ILCs are highly heterogeneous cell types between individuals and tissues. It also provides a global, comprehensive, and detailed description of ILC heterogeneity in humans across patients and tissues.

Functional annotation with expression validation identifies novel metastasis-relevant genes from post-GWAS risk loci in sporadic colorectal carcinomas.

BACKGROUND: Colorectal cancer (CRC) is the third highest incidence cancer and is the leading cause of cancer mortality worldwide. Metastasis to distal organ is the major cause of cancer mortality. However, the underlying genetic factors are unclear. This study aimed to identify metastasis-relevant genes and pathways for better management of metastasis-prone patients. METHODS: A case-case genome-wide association study comprising 2677 sporadic Chinese CRC cases (1282 metastasis-positive vs 1395 metastasis-negative) was performed using the Human SNP6 microarray platform and analysed with the correlation/trend test based on the additive model. SNP variants with association testing -log10 p value ≥5 were imported into Functional Mapping and Annotation (FUMA) for functional annotation. RESULTS: Glycolysis was uncovered as the top hallmark gene set. Transcripts from two of the five genes profiled, hematopoietic substrate 1 associated protein X 1 (HAX1) and hyaluronan-mediatedmotility receptor (HMMR), were significantly upregulated in the metastasis-positive tumours. In contrast to disease-risk variants, HAX1 appeared to act synergistically with HMMR in significantly impacting metastasis-free survival. Examining the subtype datasets with FUMA and Ingenuity Pathway Analysis (IPA) identified distinct pathways demonstrating sexual dimorphism in CRC metastasis. CONCLUSIONS: Combining genome-wide association testing with in silico functional annotation and wet-bench validation identified metastasis-relevant genes that could serve as features to develop subtype-specific metastasis-risk signatures for tailored management of patients with stage I-III CRC.

Identification of mechanism of cancer-cell-specific reactivation of hTERT offers therapeutic opportunities for blocking telomerase specifically in human colorectal cancer.

Transcriptional reactivation of hTERT is the limiting step in tumorigenesis. While mutations in hTERT promoter present in 19% of cancers are recognized as key drivers of hTERT reactivation, mechanisms by which wildtype hTERT (WT-hTERT) promoter is reactivated, in majority of human cancers, remain unknown. Using primary colorectal cancers (CRC) we identified Tert INTeracting region 2 (T-INT2), the critical chromatin region essential for reactivating WT-hTERT promoter in CRCs. Elevated ß-catenin and JunD level in CRC facilitates chromatin interaction between hTERT promoter and T-INT2 that is necessary to turn on hTERTexpression. Pharmacological screens uncovered salinomycin, which inhibits JunD mediated hTERT-T-INT2 interaction that is required for the formation of a stable transcription complex on the hTERT promoter. Our results showed for the first time how known CRC alterations, such as APC, lead to WT-hTERT promoter reactivation during stepwise-tumorigenesis and provide a new perspective for developing cancer-specific drugs.

Healthy and cancer cells harbor the same DNA sequence, but reactivation of the Human Telomerase Reverse Transcriptase (hTERT) gene is observed only in cancer cells. How does that happen was not known for over three decades of research? This study identifies a specific DNA structure that forms only in cancer cells and brings the necessary molecular machinery into the correct position to activate the hTERT gene. The detailed mechanism of hTERT activation provided in this study will be instrumental in designing cancer cell-specific hTERT inhibitors, especially since all the other ways of inhibiting telomerase failed in the clinic.

Bystander CD8+ T cells are abundant and phenotypically distinct in human tumour infiltrates.

Various forms of immunotherapy, such as checkpoint blockade immunotherapy, are proving to be effective at restoring T cell-mediated immune responses that can lead to marked and sustained clinical responses, but only in some patients and cancer types1-4. Patients and tumours may respond unpredictably to immunotherapy partly owing to heterogeneity of the immune composition and phenotypic profiles of tumour-infiltrating lymphocytes (TILs) within individual tumours and between patients5,6. Although there is evidence that tumour-mutation-derived neoantigen-specific T cells play a role in tumour control2,4,7-10, in most cases the antigen specificities of phenotypically diverse tumour-infiltrating T cells are largely unknown. Here we show that human lung and colorectal cancer CD8+ TILs can not only be specific for tumour antigens (for example, neoantigens), but also recognize a wide range of epitopes unrelated to cancer (such as those from Epstein-Barr virus, human cytomegalovirus or influenza virus). We found that these bystander CD8+ TILs have diverse phenotypes that overlap with tumour-specific cells, but lack CD39 expression. In colorectal and lung tumours, the absence of CD39 in CD8+ TILs defines populations that lack hallmarks of chronic antigen stimulation at the tumour site, supporting their classification as bystanders. Expression of CD39 varied markedly between patients, with some patients having predominantly CD39- CD8+ TILs. Furthermore, frequencies of CD39 expression among CD8+ TILs correlated with several important clinical parameters, such as the mutation status of lung tumour epidermal growth factor receptors. Our results demonstrate that not all tumour-infiltrating T cells are specific for tumour antigens, and suggest that measuring CD39 expression could be a straightforward way to quantify or isolate bystander T cells.

Towards proactive palliative care in oncology: developing an explainable EHR-based machine learning model for mortality risk prediction.

BACKGROUND: Ex-ante identification of the last year in life facilitates a proactive palliative approach. Machine learning models trained on electronic health records (EHR) demonstrate promising performance in cancer prognostication. However, gaps in literature include incomplete reporting of model performance, inadequate alignment of model formulation with implementation use-case, and insufficient explainability hindering trust and adoption in clinical settings. Hence, we aim to develop an explainable machine learning EHR-based model that prompts palliative care processes by predicting for 365-day mortality risk among patients with advanced cancer within an outpatient setting. METHODS: Our cohort consisted of 5,926 adults diagnosed with Stage 3 or 4 solid organ cancer between July 1, 2017, and June 30, 2020 and receiving ambulatory cancer care within a tertiary center. The classification problem was modelled using Extreme Gradient Boosting (XGBoost) and aligned to our envisioned use-case: "Given a prediction point that corresponds to an outpatient cancer encounter, predict for mortality within 365-days from prediction point, using EHR data up to 365-days prior." The model was trained with 75% of the dataset (n = 39,416 outpatient encounters) and validated on a 25% hold-out dataset (n = 13,122 outpatient encounters). To explain model outputs, we used Shapley Additive Explanations (SHAP) values. Clinical characteristics, laboratory tests and treatment data were used to train the model. Performance was evaluated using area under the receiver operating characteristic curve (AUROC) and area under the precision-recall curve (AUPRC), while model calibration was assessed using the Brier score. RESULTS: In total, 17,149 of the 52,538 prediction points (32.6%) had a mortality event within the 365-day prediction window. The model demonstrated an AUROC of 0.861 (95% CI 0.856-0.867) and AUPRC of 0.771. The Brier score was 0.147, indicating slight overestimations of mortality risk. Explanatory diagrams utilizing SHAP values allowed visualization of feature impacts on predictions at both the global and individual levels. CONCLUSION: Our machine learning model demonstrated good discrimination and precision-recall in predicting 365-day mortality risk among individuals with advanced cancer. It has the potential to provide personalized mortality predictions and facilitate earlier integration of palliative care.

Spatial profiling of gastric cancer patient-matched primary and locoregional metastases reveals principles of tumour dissemination.

OBJECTIVE: Endoscopic mucosal biopsies of primary gastric cancers (GCs) are used to guide diagnosis, biomarker testing and treatment. Spatial intratumoural heterogeneity (ITH) may influence biopsy-derived information. We aimed to study ITH of primary GCs and matched lymph node metastasis (LNmet). DESIGN: GC resection samples were annotated to identify primary tumour superficial (PTsup), primary tumour deep (PTdeep) and LNmet subregions. For each subregion, we determined (1) transcriptomic profiles (NanoString 'PanCancer Progression Panel', 770 genes); (2) next-generation sequencing (NGS, 225 gastrointestinal cancer-related genes); (3) DNA copy number profiles by multiplex ligation-dependent probe amplification (MLPA, 16 genes); and (4) histomorphological phenotypes. RESULTS: NanoString profiling of 64 GCs revealed no differences between PTsup1 and PTsup2, while 43% of genes were differentially expressed between PTsup versus PTdeep and 38% in PTsup versus LNmet. Only 16% of genes were differently expressed between PTdeep and LNmet. Several genes with therapeutic potential (eg IGF1, PIK3CD and TGFB1) were overexpressed in LNmet and PTdeep compared with PTsup. NGS data revealed orthogonal support of NanoString results with 40% mutations present in PTdeep and/or LNmet, but not in PTsup. Conversely, only 6% of mutations were present in PTsup and were absent in PTdeep and LNmet. MLPA demonstrated significant ITH between subregions and progressive genomic changes from PTsup to PTdeep/LNmet. CONCLUSION: In GC, regional lymph node metastases are likely to originate from deeper subregions of the primary tumour. Future clinical trials of novel targeted therapies must consider assessment of deeper subregions of the primary tumour and/or metastases as several therapeutically relevant genes are only mutated, overexpressed or amplified in these regions.

CD30+OX40+ Treg is associated with improved overall survival in colorectal cancer.

Regulatory T cells (Tregs) are often enriched in tumors, where their immunosuppressive function has a key role in tumor persistence and progression. In colorectal cancer (CRC), however, Tregs are frequently associated with an improved clinical outcome. Tumor-infiltrating Tregs have been shown to exhibit a distinct signature comprising the co-stimulatory molecules (OX40, 4-1BB), cytokine receptors (IL1R2, IL21R, CCR8, CD30), and co-inhibitory molecules (PD-L1, TIGIT). Here, we showed by flow cytometry that circulating CD45RO+ Tregs from patients with CRC (n = 25) have elevated CD30 and OX40 expression compared to healthy subjects (n = 14). We identified co-expression of CD30 and OX40 on circulating CD45RO+ Tregs using single-cell images captured by the DEPArray™ system. The frequency of CD30+OX40+CD45RO+ Tregs was significantly higher in CRC patients than in healthy subjects (P < 0.001). Importantly, receiver operating characteristic analysis confirmed that this CD30+OX40+ Treg subset could strongly discriminate between CRC patients and healthy subjects with the highest accuracy of 92.3%, an AUC of 0.92, a sensitivity of 88%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 82.35%, and a trade-off value of 3.44%, compared to other Treg subsets. Consistently, multiplex-IHC/IF of tumor-infiltrating Tregs revealed a significant association between high densities of CD30+OX40+ Tregs and improved overall survival; no such association was found for other subsets. These data suggest a potential role for CD30+OX40+ Tregs as a diagnostic or prognostic biomarker in CRC.

Living with long-term consequences: Experience of follow-up care and support needs among Asian long-term colorectal cancer survivors.

OBJECTIVES: This study aimed to provide an in-depth exploration of follow-up care experiences and supportive care needs in long-term colorectal cancer (CRC) survivors within multiethnic Asian communities. METHODS: Semi-structured in-depth interviews were conducted on a purposive sample of 30 long-term CRC survivors who had completed all treatment without recurrence ranging 2 to 17 years in Singapore. Interviews were audio-recorded and transcribed verbatim. Thematic analysis was conducted following grounded theory approach. RESULTS: Four themes represented the experience of the Asian long-term CRC survivors: (a) living with long-term consequences, (b) dealing with unceasing adaptation demands, (c) navigating a healthcare journey with limited direction, (d) regaining mastery through adversity. CRC and its treatment had profound physical impacts on some long-term survivors and these effected their psychological well-being. A sense of abandonment and vulnerability following the cessation of a 5-year follow-up care was repeatedly expressed. Participants defined recovery from CRC as not merely surviving but also having high physical function and full independence. They often sought less conventional remedies and medicine based on cultural beliefs rather than current evidence. Participants noted pervasive social stigma associated with CRC that impeded their inclusion in the workforce. CONCLUSIONS: Asian long-term CRC survivors experienced multiple challenges and needs relating to the care experience, information provision and workforce stigmatization, and several of which were unique to the Asian context. Future work will need to consider the implementation of culturally tailored cancer survivorship care plans that incorporate the specific needs of Asian CRC survivors.

Frequent Coamplification of Receptor Tyrosine Kinase and Downstream Signaling Genes in Japanese Primary Gastric Cancer and Conversion in Matched Lymph Node Metastasis.

OBJECTIVE: To establish the gene copy number status of receptor tyrosine kinase (RTK) and downstream signaling (DSS) genes genes in primary gastric cancer (primGC) and matched lymph node metastases (LNmet). BACKGROUND: Evidence suggests that coamplification between RTKs and DSSs and conversion between primGC and LNmet are associated with resistance to targeted therapy. METHODS: DNA from 237 Japanese primGC and 103 matched LNmet was analyzed using a newly developed multiplex ligation-dependent probe amplification (MLPA) probemix to investigate RTK (EGFR, HER2, FGFR2, and MET) and DSS (PIK3CA, KRAS, MYC, and CCNE1) gene copy number status. Results were compared between primGC and LNmet and related to clinicopathological data including survival. RESULTS: A total of 150 (63%) primGC had either RTK or DSS amplification. DSS coamplification was more frequent than RTK coamplification in primGC and LNmets. Moreover, 70 (30%) GC showed a disconcordant RTK and/or DSS gene copy number status between primGC and LNmet, most common was negative conversion for DSS genes (n=40 GC). The presence of RTK amplification in primGC was related to poorer survival in univariate analysis (P=0.04). CONCLUSIONS: This is the first and most comprehensive study in gastric cancer investigating the concordance between gene copy number status of targetable RTKs and downstream signaling oncogenes in primGC and LNmets. Future studies need to establish whether the relative high frequency of RTK and DSS coamplification and/or the relative high rate of negative conversion in LNmet can potentially explain recent failures of RTK targeted therapy in gastric cancer patients.

Breast cancer in women with neurofibromatosis type 1 (NF1): a comprehensive case series with molecular insights into its aggressive phenotype.

PURPOSE: The purpose of the study was to improve the understanding of NF1-associated breast cancer, given the increased risk of breast cancer in this tumour predisposition syndrome and the limited data. METHODS: We identified 18 women with NF1 and breast cancer at our institution. Clinical and pathologic characteristics of NF1-associated breast cancers were compared with 7132 breast cancers in patients without NF1 from our institutional database. Next generation sequencing was performed on DNA from blood and breast cancer specimens available. Blood specimens negative for NF1 mutation were subjected to multiplex ligation-dependent probe amplification (MLPA) to identify complete/partial deletions or duplications. Expression of neurofibromin in the NF1-associated breast cancers was evaluated using immunohistochemistry. RESULTS: There was a higher frequency of grade 3 (83.3% vs 45.4%, p = 0.005), oestrogen receptor (ER) negative (66.7% vs 26.3%, p < 0.001) and human epidermal growth factor receptor 2 (HER2)-positive (66.7% vs 23.4%, p < 0.001) tumours among NF1 patients compared to non-NF1 breast cancers. Overall survival was inferior in NF1 patients in multivariable analysis (hazard ratio 2.25, 95% CI 1.11-4.60; p = 0.025). Apart from germline NF1 mutations (11/16; 69%), somatic mutations in TP53 (8/10; 80%), second-hit NF1 (2/10; 20%), KMT2C (4/10; 40%), KMT2D (2/10; 20%), and PIK3CA (2/10; 20%) were observed. Immunohistochemical expression of neurofibromin was seen in the nuclei and/or cytoplasm of all specimens, but without any consistent pattern in the intensity or extent. CONCLUSIONS: This comprehensive series of NF1-associated breast cancers suggests that their aggressive features are related to germline NF1 mutations in cooperation with somatic mutations in TP53, KMT2C and other genes.

Preoperative Prognostic Factors After Liver Resection for Non-Colorectal, Non-Neuroendocrine Liver Metastases and Validation of the Adam Score in an Asian Population.

BACKGROUND: Historically, the benefit of liver resection for non-colorectal, non-neuroendocrine (NCNN) liver metastases has been controversial. This study aims to determine the preoperative prognostic factors of liver resection for NCNN liver metastases and validate the Adam score in an Asian population. METHODS: Consecutive patients who underwent liver resection for NCNN liver metastases were identified retrospectively from a prospective liver resection database of the single institution between 2001 and 2014. Univariate Cox regression models were used to identify associations with outcome variables. Recurrence-free interval and overall survival were determined using the Kaplan-Meier method and compared using log-rank test. RESULTS: Seventy-eight consecutive patients were identified, which met the study criteria. Univariate analysis demonstrated that adenocarcinoma histology of primary cancer, disease-free interval and number of nodules were significant predictors of survival. Four of the six components of Adam score were significant predictors of survival. These were the presence of extrahepatic metastases, R2 resection, disease-free interval and type of a primary tumour. The total Adam score was also a significant predictor of survival. CONCLUSION: Liver resection for NCNN liver metastases is a safe and viable treatment option in carefully selected patients. Significant preoperative prognostic factors include adenocarcinoma primary tumours, disease-free interval and number of nodules. The total Adam score was a good predictor of overall survival and can be used to risk stratify patients undergoing hepatic resection for NCNN liver metastases.

SETD2 histone modifier loss in aggressive GI stromal tumours.

BACKGROUND: GI stromal tumours (GISTs) are clinically heterogenous exhibiting varying degrees of disease aggressiveness in individual patients. OBJECTIVES: We sought to identify genetic alterations associated with high-risk GIST, explore their molecular consequences, and test their utility as prognostic markers. DESIGNS: Exome sequencing of 18 GISTs was performed (9 patients with high-risk/metastatic and 5 patients with low/intermediate-risk), corresponding to 11 primary and 7 metastatic tumours. Candidate alterations were validated by prevalence screening in an independent patient cohort (n=120). Functional consequences of SETD2 mutations were investigated in primary tissues and cell lines. Transcriptomic profiles for 8 GISTs (4 SETD2 mutated, 4 SETD2 wild type) and DNA methylation profiles for 22 GISTs (10 SETD2 mutated, 12 SETD2 wild type) were analysed. Statistical associations between molecular, clinicopathological factors, and relapse-free survival were determined. RESULTS: High-risk GISTs harboured increased numbers of somatic mutations compared with low-risk GISTs (25.2 mutations/high-risk cases vs 6.8 mutations/low-risk cases; two sample t test p=3.1×10-5). Somatic alterations in the SETD2 histone modifier gene occurred in 3 out of 9 high-risk/metastatic cases but no low/intermediate-risk cases. Prevalence screening identified additional SETD2 mutations in 7 out of 80 high-risk/metastatic cases but no low/intermediate-risk cases (n=29). Combined, the frequency of SETD2 mutations was 11.2% (10/89) and 0% (0/34) in high-risk and low-risk GISTs respectively. SETD2 mutant GISTs exhibited decreased H3K36me3 expression while SETD2 silencing promoted DNA damage in GIST-T1 cells. In gastric GISTs, SETD2 mutations were associated with overexpression of HOXC cluster genes and a DNA methylation signature of hypomethylated heterochromatin. Gastric GISTs with SETD2 mutations, or GISTs with hypomethylated heterochromatin, showed significantly shorter relapse-free survival on univariate analysis (log rank p=4.1×10-5). CONCLUSIONS: Our data suggest that SETD2 is a novel GIST tumour suppressor gene associated with disease progression. Assessing SETD2 genetic status and SETD2-associated epigenomic phenotypes may guide risk stratification and provide insights into mechanisms of GIST clinical aggressiveness.

A Randomized Phase II Study of FOLFOX With or Without the MET Inhibitor Onartuzumab in Advanced Adenocarcinoma of the Stomach and Gastroesophageal Junction.

BACKGROUND: The phase II YO28252 study (NCT01590719) examined first-line onartuzumab plus mFOLFOX6 in patients with metastatic, human epidermal growth factor receptor 2-negative adenocarcinoma of the stomach or gastroesophageal junction. MET immunohistochemistry expression as a biomarker of onartuzumab activity was also examined. PATIENTS AND METHODS: Patients were randomized 1:1 to receive standard mFOLFOX6 plus onartuzumab (10 mg/kg) or placebo in 2-week cycles for 12 cycles, followed by onartuzumab or placebo until disease progression. Coprimary endpoints were progression-free survival (PFS) in intent-to-treat (ITT) and MET-positive populations. The target hazard ratio (HR) was 0.70 for patients in the ITT group and 0.60 in the MET-positive population. Secondary endpoints were overall survival (OS), overall response rate (ORR), and safety. RESULTS: Overall, 123 patients were enrolled (n = 62 onartuzumab, n = 61 placebo). Median PFS was 6.77 versus 6.97 months for onartuzumab versus placebo, respectively (HR, 1.08; 95% confidence interval [CI], 0.71-1.63; p = .71). In the MET-positive population, median PFS was 5.95 versus 6.80 months, onartuzumab versus placebo (HR, 1.38; 95% CI, 0.60-3.20; p = .45). Median OS was 10.61 months for onartuzumab versus 11.27 months for placebo) (HR, 1.06, 0.64-1.75; p = .83). In the MET-positive population, median OS was 8.51 versus 8.48 months for onartuzumab versus placebo, respectively (HR, 1.12, 95% CI, 0.45-2.78; p = .80). ORR was 60.5% for the onartuzumab group and 57.1% for placebo. Grade 3-5 adverse events (AEs) were seen in 88.3% of patients receiving onartuzumab and in 78.3% of patients receiving placebo, with serious AEs in 55% and 40%, respectively. CONCLUSION: The addition of onartuzumab to mFOLFOX6 in gastric cancer did not improve efficacy in an unselected population or in a MET immunohistochemistry-positive population. IMPLICATIONS FOR PRACTICE: The YO28252 study demonstrated that the addition of the anti-MET agent onartuzumab to mFOLFOX6 for treatment of gastric cancer did not improve efficacy in an overall study population or those selected for positive MET status by immunohistochemistry. This highlights the importance of correctly selecting biomarkers for targeted therapies. A multivariate analysis suggested that MET positivity may still be prognostic for worse median overall survival in gastric cancer; therefore, it is important to continue investigation into the optimal approach to inhibit MET signaling in gastric cancer.

Signatures of tumour immunity distinguish Asian and non-Asian gastric adenocarcinomas.

OBJECTIVE: Differences in gastric cancer (GC) clinical outcomes between patients in Asian and non-Asian countries has been historically attributed to variability in clinical management. However, recent international Phase III trials suggest that even with standardised treatments, GC outcomes differ by geography. Here, we investigated gene expression differences between Asian and non-Asian GCs, and if these molecular differences might influence clinical outcome. DESIGN: We compared gene expression profiles of 1016 GCs from six Asian and three non-Asian GC cohorts, using a two-stage meta-analysis design and a novel biostatistical method (RUV-4) to adjust for technical variation between cohorts. We further validated our findings by computerised immunohistochemical analysis on two independent tissue microarray (TMA) cohorts from Asian and non-Asian localities (n=665). RESULTS: Gene signatures differentially expressed between Asians and non-Asian GCs were related to immune function and inflammation. Non-Asian GCs were significantly enriched in signatures related to T-cell biology, including CTLA-4 signalling. Similarly, in the TMA cohorts, non-Asian GCs showed significantly higher expression of T-cell markers (CD3, CD45R0, CD8) and lower expression of the immunosuppressive T-regulatory cell marker FOXP3 compared to Asian GCs (p<0.05). Inflammatory cell markers CD66b and CD68 also exhibited significant cohort differences (p<0.05). Exploratory analyses revealed a significant relationship between tumour immunity factors, geographic locality-specific prognosis, and postchemotherapy outcomes. CONCLUSIONS: Analyses of >1600 GCs suggest that Asian and non-Asian GCs exhibit distinct tumour immunity signatures related to T-cell function. These differences may influence geographical differences in clinical outcome, and the design of future trials particularly in immuno-oncology.

An integrative approach identified genes associated with drug response in gastric cancer.

Gastric cancer (GC) is the second leading cause of global cancer mortality worldwide. However, the molecular mechanism underlying its carcinogenesis and drug resistance is not well understood. To identify novel functionally important genes that were differentially expressed due to combinations of genetic and epigenetic changes, we analyzed datasets containing genome-wide mRNA expression, DNA copy number alterations and DNA methylation status from 154 primary GC samples and 47 matched non-neoplastic mucosa tissues from Asian patients. We used concepts of 'within' and 'between' statistical analysis to compare the difference between tumors and controls within each platform, and assessed the correlations between platforms. This 'multi-regulated gene (MRG)' analysis identified 126 differentially expressed genes that underwent a combination of copy number and DNA methylation changes. Most genes were located at genomic loci associated with GC. Statistical enrichment analysis showed that MRGs were enriched for cancer, GC and drug response. We analysed several MRGs that previously had not been associated with GC. Knockdown of DDX27, TH1L or IDH3G sensitized cells to epirubicin or cisplatin, and knockdown of RAI14 reduced cell proliferation. Further studies showed that overexpression of DDX27 reduced epirubicin-induced DNA damage and apoptosis. Levels of DDX27 mRNA and protein were increased in early-stage gastric tumors, and may be a potential diagnostic and prognostic marker for GC. In summary, we used an integrative bioinformatics strategy to identify novel genes that are altered in GC and regulate resistance of GC cells to drugs in vitro.

Assessment of Web-Based Consumer Reviews as a Resource for Drug Performance.

BACKGROUND: Some health websites provide a public forum for consumers to post ratings and reviews on drugs. Drug reviews are easily accessible and comprehensible, unlike clinical trials and published literature. Because the public increasingly uses the Internet as a source of medical information, it is important to know whether such information is reliable. OBJECTIVE: We aim to examine whether Web-based consumer drug ratings and reviews can be used as a resource to compare drug performance. METHODS: We analyzed 103,411 consumer-generated reviews on 615 drugs used to treat 249 disease conditions from the health website WebMD. Statistical analysis identified 427 drug pairs from 24 conditions for which two drugs treating the same condition had significantly and substantially different satisfaction ratings (with at least a half-point difference between Web-based ratings and P<.01). PubMed and Google Scholar were searched for publications that were assessed for concordance with findings online. RESULTS: Scientific literature was found for 77 out of the 427 drug pairs and compared to findings online. Nearly two-thirds (48/77, 62%) of the online drug trends with at least a half-point difference in online ratings were supported by published literature (P=.02). For a 1-point online rating difference, the concordance rate increased to 68% (15/22) (P=.07). The discrepancies between scientific literature and findings online were further examined to obtain more insights into the usability of Web-based consumer-generated reviews. We discovered that (1) drugs with FDA black box warnings or used off-label were rated poorly in Web-based reviews, (2) drugs with addictive properties were rated higher than their counterparts in Web-based reviews, and (3) second-line or alternative drugs were rated higher. In addition, Web-based ratings indicated drug delivery problems. If FDA black box warning labels are used to resolve disagreements between publications and online trends, the concordance rate increases to 71% (55/77) (P<.001) for a half-point rating difference and 82% (18/22) for a 1-point rating difference (P=.002). Our results suggest that Web-based reviews can be used to inform patients' drug choices, with certain caveats. CONCLUSIONS: Web-based reviews can be viewed as an orthogonal source of information for consumers, physicians, and drug manufacturers to assess the performance of a drug. However, one should be cautious to rely solely on consumer reviews as ratings can be strongly influenced by the consumer experience.

Identification of molecular subtypes of gastric cancer with different responses to PI3-kinase inhibitors and 5-fluorouracil.

BACKGROUND & AIMS: Almost all gastric cancers are adenocarcinomas, which have considerable heterogeneity among patients. We sought to identify subtypes of gastric adenocarcinomas with particular biological properties and responses to chemotherapy and targeted agents. METHODS: We compared gene expression patterns among 248 gastric tumors; using a robust method of unsupervised clustering, consensus hierarchical clustering with iterative feature selection, we identified 3 major subtypes. We developed a classifier for these subtypes and validated it in 70 tumors from a different population. We identified distinct genomic and epigenomic properties of the subtypes. We determined drug sensitivities of the subtypes in primary tumors using clinical survival data, and in cell lines through high-throughput drug screening. RESULTS: We identified 3 subtypes of gastric adenocarcinoma: proliferative, metabolic, and mesenchymal. Tumors of the proliferative subtype had high levels of genomic instability, TP53 mutations, and DNA hypomethylation. Cancer cells of the metabolic subtype were more sensitive to 5-fluorouracil than the other subtypes. Furthermore, in 2 independent groups of patients, those with tumors of the metabolic subtype appeared to have greater benefits with 5-fluorouracil treatment. Tumors of the mesenchymal subtype contain cells with features of cancer stem cells, and cell lines of this subtype are particularly sensitive to phosphatidylinositol 3-kinase-AKT-mTOR inhibitors in vitro. CONCLUSIONS: Based on gene expression patterns, we classified gastric cancers into 3 subtypes, and validated these in an independent set of tumors. The subgroups have differences in molecular and genetic features and response to therapy; this information might be used to select specific treatment approaches for patients with gastric cancer.

Integrated epigenomics identifies BMP4 as a modulator of cisplatin sensitivity in gastric cancer.

OBJECTIVE: Cisplatin is a widely used gastric cancer (GC) chemotherapy; however, genetic factors regulating GC responses to cisplatin remain obscure. Identifying genes regulating cisplatin resistance could aid clinicians in tailoring treatments, by distinguishing cisplatin sensitive patients from those who might benefit from alternative platinum therapies, and highlight novel targeted strategies for overcoming cisplatin resistance. Here integrated epigenomics is applied to identify genes associated with GC cisplatin resistance. DESIGN: 20 GC cell lines were subjected to gene expression profiling, DNA methylation profiling and drug response assays. The molecular data were integrated to identify genes highly expressed and unmethylated specifically in cisplatin-resistant lines. Candidate genes were functionally tested by several in vitro and in vivo assays. Clinical impact of candidate genes was also assessed in a cohort of 197 GC patients. RESULTS: Epigenomic analysis identified bone morphogenetic protein 4 (BMP4) as an epigenetically regulated gene highly expressed in cisplatin-resistant lines. Functional assays confirmed that BMP4 is necessary and sufficient for the expression of several prooncogenic traits, likely mediated through stimulation of the epithelial-mesenchymal transition. In primary tumours, BMP4 promoter methylation levels were inversely correlated with BMP4 expression, and patients with high BMP4-expressing tumours exhibited significantly worse prognosis. Therapeutically, targeted genetic inhibition of BMP4 caused significant sensitisation of GC cells to cisplatin. Notably, BMP4-expressing GCs also did not exhibit cross resistance to oxaliplatin. CONCLUSIONS: BMP4 epigenetic and expression status may represent promising biomarkers for GC cisplatin resistance. Targeting BMP4 may sensitise GC cells to cisplatin. Oxaliplatin, a clinically acceptable cisplatin alternative, may represent a potential therapeutic option for BMP4-positive GCs.