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.

Therapeutic antibody targeting natriuretic peptide receptor 1 inhibits gastric cancer growth via BCL-2-mediated intrinsic apoptosis.

Despite recent advances in the development of therapeutic antibodies, the prognosis of unresectable or metastatic gastric cancer (GC) remains poor. Here, we searched for genes involved in the malignant phenotype of GC and investigated the potential of one candidate gene to serve as a novel therapeutic target. Analysis of transcriptome datasets of GC identified natriuretic peptide receptor 1 (NPR1), a plasma membrane protein, as a potential target. We employed a panel of human GC cell lines and gene-specific small interfering RNA-mediated NPR1 silencing to investigate the roles of NPR1 in malignancy-associated functions and intracellular signaling pathways. We generated an anti-NPR1 polyclonal antibody and examined its efficacy in a mouse xenograft model of GC peritoneal dissemination. Associations between NPR1 expression in GC tissue and clinicopathological factors were also evaluated. NPR1 mRNA was significantly upregulated in several GC cell lines compared with normal epithelial cells. NPR1 silencing attenuated GC cell proliferation, invasion, and migration, and additionally induced the intrinsic apoptosis pathway associated with mitochondrial dysfunction and caspase activation via downregulation of BCL-2. Administration of anti-NPR1 antibody significantly reduced the number and volume of GC peritoneal tumors in xenografted mice. High expression of NPR1 mRNA in clinical GC specimens was associated with a significantly higher rate of postoperative recurrence and poorer prognosis. NPR1 regulates the intrinsic apoptosis pathway and plays an important role in promoting the GC malignant phenotype. Inhibition of NPR1 with antibodies may have potential as a novel therapeutic modality for unresectable or metastatic GC.

OPLAH Protein Expression Stratifies the Prognosis of Patients With Squamous Cell Carcinoma of the Esophagus.

BACKGROUND/AIM: Squamous cell carcinoma is one of the major subtypes of esophageal carcinoma, and the 5-year overall survival rate of esophageal squamous cell carcinoma patients who underwent curative treatment remains below 40%. We aimed to detect and validate the prognosticators of esophageal squamous cell carcinoma in patients who underwent radical esophagectomy. MATERIALS AND METHODS: Comprehensive analysis of transcriptome and clinical data from The Cancer Genome Atlas revealed OPLAH as one of the differentially expressed genes between esophageal squamous cell carcinoma tissues and normal esophageal mucosa. OPLAH expression changes were significantly associated with a patient prognosis. OPLAH protein levels were further evaluated by immunohisto-chemistry in esophageal squamous cell carcinoma tissues (n=177) as well as in serum samples (n=54) using ELISA. RESULTS: OPLAH mRNA was significantly overexpressed in esophageal squamous cell carcinoma tissues compared to normal esophageal mucosa, and patients with high OPLAH mRNA expression have a significantly poorer prognosis, according to The Cancer Genome Atlas data. The high staining intensity of OPLAH protein in esophageal squamous cell carcinoma tissue clearly stratified patient prognosis. According to multivariable analysis, high OPLAH protein expression was an independent prognostic factor for survival after surgery. Pre-neoadjuvant chemotherapy serum OPLAH protein concentrations were significantly associated with clinical tumor depth and node positivity and, consequently, with advanced clinical stage. The serum OPLAH protein concentration was significantly decreased by neoadjuvant chemotherapy. CONCLUSION: OPLAH protein expression in cancerous tissue and serum may have clinical utility towards stratifying prognosis of patients with esophageal squamous cell carcinoma.

High Preoperative Platelet to Lymphocyte Ratio Is Associated with a Greater Risk of Postoperative Complications and Hematogenous Recurrences in Esophageal Squamous Cell Carcinoma Patients Receiving Neoadjuvant Treatment.

INTRODUCTION: Neoadjuvant treatment is currently the gold standard for advanced esophageal squamous cell carcinoma (ESCC). Several studies have examined the value of blood count-based indexes for predicting short- and long-term outcomes after esophagectomy for ESCC, but the relative predictive value of pretreatment, preoperative, and postoperative indexes has not yet been examined. METHODS: This study included 320 patients with thoracic ESCC who underwent subtotal esophagectomy after neoadjuvant chemotherapy or chemoradiotherapy at our institution. A total of 19 candidate blood parameters were measured before neoadjuvant treatment as well as preoperatively and postoperatively. The ability of the parameters to predict postoperative complications, overall survival (OS), and relapse-free survival (RFS) was assessed using receiver operating characteristic (ROC) curve analysis and Cox regression analysis. RESULTS: ROC curve analysis indicated that preoperative platelet to lymphocyte ratio (PLR) had the best predictive value with an optimal cutoff value of 166. Patients with high preoperative PLR (≥166) had significantly shorter OS and RFS and significantly higher incidences of hematogenous recurrence and postoperative pneumonia compared with patients with low preoperative PLR (<166). In multivariate analysis, high preoperative PLR and high preoperative serum carcinoembryonic antigen level were independent predictors of poor prognosis. CONCLUSION: Preoperative PLR is a good predictor of short- and long-term prognosis in patients with advanced ESCC who receive neoadjuvant treatment followed by radical resection.

Update on molecular biomarkers for diagnosis and prediction of prognosis and treatment responses in gastric cancer.

Gastric cancer (GC) is one of the leading causes of cancer-related deaths worldwide, and its high mortality rate is a serious problem in many regions. To improve prognosis, it is necessary to identify novel biomarkers for the early detection of GC, along with its prognosis, risk of metastatic recurrence, and predicted response to chemotherapy, and to develop individualized treatment strategies. Advances in microarray and sequencing techniques have led to the elucidation of cancer-related gene mutations and aberrant expression levels, which have deepened our knowledge of GC. Further searches for sensitive biomarkers are needed to improve the management of patients with GC. In this review article, we update the current knowledge of GC biomarkers, examine recently published literature, and introduce some representative molecules.

Tissue RNFT2 Expression Levels Are Associated With Peritoneal Recurrence and Poor Prognosis in Gastric Cancer.

BACKGROUND/AIM: Disease recurrence is frequently observed after curative resection of advanced gastric cancer resulting in a poor prognosis. In the present study, we identified a candidate biomarker to predict recurrence and prognosis after curative resection of gastric cancer. MATERIALS AND METHODS: A transcriptome analysis was conducted using surgically resected cancerous tissue from patients with metastatic gastric cancer to identify genes that are upregulated in primary and metastatic tissues. RESULTS: Ring finger protein, transmembrane 2 (RNFT2) mRNA expression was upregulated in primary gastric cancer tissues and metastases compared with non-cancerous tissues. RNFT2 expression in gastric cancer cell lines was positively correlated with the EMT-related molecules GSC, MMP9, and RAC1. The RNFT2 high expression group exhibited a significantly shorter postoperative overall survival. Peritoneal recurrence was significantly higher in the RNFT2 high expression group. CONCLUSION: RNFT2 mRNA expression predicts peritoneal recurrence and is a potential prognostic biomarker for gastric cancer following curative gastrectomy.

The Preoperative Prognostic Nutritional Index Predicts Short-Term and Long-Term Outcomes of Patients with Stage II/III Gastric Cancer: Analysis of a Multi-Institution Dataset.

BACKGROUND/AIMS: Identification of nutritional indicators to predict short-term and long-term outcomes is necessary to provide appropriate treatment to patients with gastric cancer. METHODS: We designed an analysis of a multicenter dataset of patients with gastric cancer who underwent gastrectomy between 2010 and 2014. We enrolled 842 eligible patients who had stage II/III gastric cancer. The area under the curve (AUC) values were compared among prognostic nutritional index (PNI), calculated as 10 × albumin g/dL + 0.005 × total lymphocyte count/mm3, and its constituents, and the predictive value of preoperative PNI for postoperative short-term and long-term outcomes was evaluated. RESULTS: Preoperative PNI exhibited higher AUC values (0.719) for 1-year survival than its constituents, and the optimal cutoff value was 47. The disease-free and overall survival of patients in the PNI-low group were significantly shorter compared with those in the PNI-high group. The prognostic difference between the PNI-high and PNI-low groups was significantly greater in the subgroup of patients who underwent total gastrectomy. Clinically relevant postoperative complications were more frequently observed in the PNI-low group. CONCLUSIONS: The preoperative PNI is a useful predictor reflecting the incidence of complications after gastrectomy and the prognosis of patients with stage II/III gastric cancer.