Surveillance for Gastric Cancer

Development of nomograms for predicting the survival of intestinal-type gastric adenocarcinoma patients after surgery

Intestinal-type gastric adenocarcinoma (IGA) is a common phenotype of gastric cancer. Currently, few studies have constructed nomograms that may predict overall (OS) and cancer-specific survival (CSS) probability after surgery. This study is to establish novel nomograms for predicting the survival of IGA patients who received surgery. A total of 1814 IGA patients who received surgery between 2000 and 2018 were selected from Surveillance, Epidemiology, and End Results database and randomly assigned to the training and validating sets at a ratio of 7:3. Then univariate and multivariate cox regression analyses were performed to screen significant indictors for the construction of nomograms. The calibration curve, the area under the receiver operating characteristic (receiver operating characteristic, ROC) curve (the area under curve, AUC), C-index, net reclassification index (NRI), integrated discrimination improvement (IDI) and decision curve analysis (DCA) curves were applied to assess the performance of the model. The significant outcomes of multivariate analysis revealed that ten variables (age, sex, race, surgery type, summary stage, grade, AJCC TNM stage, radiotherapy, number of regional nodes examined, number of regional nodes positive) were demonstrated to construct the nomogram for OS and ten variables (age, sex, race, surgery type, summary stage, grade, AJCC TNM stage, chemotherapy, number of regional nodes examined, number of regional nodes positive) for CSS. The calibration and AUC uncovered their favorable predictive performance. Subsequently, C-index, NRI, IDI and DCA curves further validated the predicative superiority of nomograms over 7th AJCC Stage System. The validated nomogram provides more reliable OS and CSS predictions for postoperative IGA patients with good accuracy, which can help surgeons in treatment decision-making and prognosis evaluation.

Deep learning in precision medicine and focus on glioma

Deep learning (DL) has been successfully applied to different fields for a range of tasks. In medicine, DL methods have been also used to improve the efficiency of disease diagnosis. In this review, we first summarize the history of the development of artificial intelligence models, demonstrate the features of the subtypes of machine learning and different DL networks, and then explore their application in the different fields of precision medicine, such as cardiology, gastroenterology, ophthalmology, dermatology, and oncology. By digging more information and extracting multilevel features from medical data, we found that DL helps doctors assess diseases automatically and monitor patients' physical health. In gliomas, research regarding application prospect of DL was mainly shown through magnetic resonance imaging and then by pathological slides. However, multi-omics data, such as whole exome sequence, RNA sequence, proteomics, and epigenomics, have not been covered thus far. In general, the quality and quantity of DL datasets still need further improvements, and more fruitful multi-omics characteristics will bring more comprehensive and accurate diagnosis in precision medicine and glioma.

Girdin acts as an oncogene in gastric cancer by regulating AKT/GSK3β/β-catenin signaling

ThE present work focused on exploring Girdin expression within gastric cancer (GC), examining the effect of Girdin on the cell phenotype of GC, and clarifying the underlying mechanisms. Girdin expression in GC samples was identified by immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR) assays. Girdin-targeting siRNAs were transfected into GC cells; later, we examined GC cell proliferation, migration, invasion, and apoptosis, respectively. Additionally, the protein expression was examined through Western blotting assay. Moreover, the tumor implantation experiment was conducted for examining Girdin knockdown in vivo. The results showed that Girdin expression elevated within GC samples, which was associated with the dismal prognostic outcome. Girdin knockdown suppressed GC cell proliferation, migration, and invasion, and enhanced apoptosis and cell cycle arrest. Girdin promoted the phosphorylation of AKT, GSK3β, and β-catenin. Moreover, Girdin inhibited the phosphorylation of β-catenin. Girdin suppressed cell apoptosis and stimulated cell migration and invasion, while AKT inhibitor (MK2206) treatment reversed the effect of Girdin overexpression, and GSK3β inhibitor (CHIR99021) treatment enhanced the effect of Girdin overexpression on GC cells. Besides, Girdin delayed tumor growth in vivo. In conclusion, Girdin was abnormally expressed in GC samples, which promoted the development of GC by regulating AKT/GSK3β/β-catenin signaling.

Gastric cancer clinical characteristics and their altered trends in South China: An epidemiological study with 2,800 cases spanning 26 years

BACKGROUND

Gastric cancer (GC) is a serious threat to human health. The clinical GC characteristics in China may be impacted by changes in people's lifestyles and the promotion of early GC (EGC) screening. The present study aims to evaluate the recent trends of GC characteristics in South China and search for hazardous factors limiting the survival time of GC patients.

METHODS

Data on GC patients that were hospitalized in the Department of Digestive Center, the First Affiliated Hospital, Sun Yat-sen University, from 1994 to 2019 were collected and divided into two categories according to the time when the EGC screening began in China: the PRE group (previous 13 years, 1994-2006) and the PAS group (past 13 years, 2007-2019).

RESULTS

We found that, although the 5-year survival rate increased in the PAS group compared with the PRE group (P < 0.0001), patients with age ≥60 years or Borrmann type IV still had a worse prognosis. In the PAS group, the larger percentages of elderly patients and patients with Borrmann type IV in the lymphatic metastases (N1) group (41.0% vs. 51.1%, P = 0.0014) and stage IV subgroup (20.7% vs. 32.2%, P = 0.016), respectively, when compared with the PRE group, may have contributed to the poor outcome of GC. By comparing the odds ratio (OR) of 5-year overall survival (OS) in the two 13-year periods, female sex and T2 turned into risk factors because of a greater proportion of Borrmann type IV or elderly patients in the PAS group (OR = 0.983, 95% CI = 0.723-1.336 vs. OR = 1.277, 95% CI = 1.028-1.586 and OR = 1.545, 95% CI = 0.499-4.775 vs. OR = 2.227, 95% CI = 1.124-4.271, respectively).

CONCLUSIONS

Despite the GC epidemiology changes, the overall prognosis of GC patients has improved in South China. However, old age and Borrmann type IV are still the major restrictions affecting the survival of GC patients, a situation which calls for additional attention.

Targeted labeling with tissue marking dyes guided by magnifying endoscopy of endoscopic submucosal dissection specimen improves the accuracy of endoscopic and histopathological diagnosis of early gastric cancer: a before–after study

BACKGROUND

Although histopathological evaluation after endoscopic submucosal dissection (ESD) is critical to assess the accuracy of endoscopic diagnosis, it is still challenging to perform precise endoscopic to pathological evaluation. We evaluated the importance of tissue marking dye (TMD)-targeted marking for post-ESD specimen guided by magnificent endoscope on histopathological accuracy and endoscopic-to-histopathological reconstruction.

STUDY DESIGN

A total of 81 specimens resected by ESD [43 without TMD marking (N-TMD group), and 38 specimens with TMD-targeted cancerous areas marking guided by post-procedural magnifying endoscopy on resected specimens (TMD group)] between January 31, 2019, and January 31, 2022 at the Renmin Hospital of Wuhan University were included in the study. The baseline characteristics of patients, discrepancies between endoscopic and histopathological diagnosis, and the impact of TMD on histopathological diagnosis and reconstruction were analyzed.

RESULTS

Discrepancies between endoscopic (pre-ESD) and histopathological (post-ESD) diagnosis increased significantly in TMD group (68.4% (26/38) for tumor areas, 26.3% (10/38) for tumor margins, and 26.3% (10/38) for tumor differentiations) when compared with N-TMD group (p < 0.0001). Deeper sections were achieved in all TMD-marked resected lesions and 27.9% (12/43) lesions in the N-TMD group (p < 0.001). More pathological evaluations in TMD group were changed from curative resection to non-curative resection [6/38(15.8%) vs 1/43(2.3%)] compared with N-TMD group (p < 0.0001). TMD-targeted marking also improved the efficiency of histopathological reconstruction on pre-procedural endoscopic images and benefit endoscopists training.

CONCLUSION

TMD-targeted labeling on resected specimens could improve precise endoscopic-to-pathological diagnosis, reconstruction by point-to-point marking and benefit endoscopists training.

Lymph node distribution in patients with remnant gastric cancer

BACKGROUND

Remnant gastric cancer (RGC) is defined as a carcinoma that develops in the gastric remnant from 5 years after gastrectomy, regardless of the primary gastric disease. The pattern of lymph node dissemination in these patients is not well understood. The present study aims to understand the lymph node distribution of patients with RGC in a single center.

METHODS

In a total of 1380 patients with gastric cancer, between 1998 and 2020, 43 patients operated on for RGC were analyzed. The pattern of lymph node dissemination was evaluated based on the number of dissected lymph node stations, the number of positive lymph node stations, the positivity index at each analyzed station, the number of dissected lymph nodes per patient, and the positivity index per lymph node station.

RESULTS

A mean of 13.0 ± 8.1 lymph nodes were dissected. The incidence of lymph node involvement by dissected station was higher at Stations 19, 11p, 3, 4sb and 7 (50, 40, 37.5, 36 and 31.7%, respectively). Among the positive dissected stations, Station 3 with 52.2%, 4sb with 39.1% and 4sa with 34.8% were the most affected.

CONCLUSION

There was no predilection for lymph node involvement when comparing the lesser and greater gastric curvature. The dissection of Stations 3, 4sb and 4sa is fundamental in surgical treatment with curative purposes. The totalization of gastrectomy with lymphadenectomy of the perigastric and supra-pancreatic stations should be the surgery of choice.

Real-time use of artificial intelligence for diagnosing early gastric cancer by magnifying image-enhanced endoscopy: a multicenter diagnostic study (with videos)

BACKGROUND AND AIMS

Endoscopy is a pivotal method for detecting early gastric cancer (EGC). However, skill among endoscopists varies greatly. Here, we proposed a deep learning-based system named ENDOANGEL-ME to diagnose EGC in magnifying image-enhanced endoscopy (M-IEE).

METHODS

M-IEE images were retrospectively obtained from 6 hospitals in China, including 4667 images for training and validation, 1324 images for internal tests, and 4702 images for external tests. One hundred eighty-seven stored videos from 2 hospitals were used to evaluate the performance of ENDOANGEL-ME and endoscopists and to assess the effect of ENDOANGEL-ME on improving the performance of endoscopists. Prospective consecutive patients undergoing M-IEE were enrolled from August 17, 2020 to August 2, 2021 in Renmin Hospital of Wuhan University to assess the applicability of ENDOANGEL-ME in clinical practice.

RESULTS

A total of 3099 patients undergoing M-IEE were enrolled in this study. The diagnostic accuracy of ENDOANGEL-ME for diagnosing EGC was 88.44% and 90.49% in internal and external images, respectively. In 93 internal videos, ENDOANGEL-ME achieved an accuracy of 90.32% for diagnosing EGC, significantly superior to that of senior endoscopists (70.16% ± 8.78%). In 94 external videos, with the assistance of ENDOANGEL-ME, endoscopists showed improved accuracy and sensitivity (85.64% vs 80.32% and 82.03% vs 67.19%, respectively). In 194 prospective consecutive patients with 251 lesions, ENDOANGEL-ME achieved a sensitivity of 92.59% (25/27) and an accuracy of 83.67% (210/251) in real clinical practice.

CONCLUSIONS

This multicenter diagnostic study showed that ENDOANGEL-ME can be well applied in the clinical setting. (Clinical trial registration number: ChiCTR2000035116.).

Real-time artificial intelligence for detecting focal lesions and diagnosing neoplasms of the stomach by white-light endoscopy (with videos)

BACKGROUND AND AIMS

White-light endoscopy (WLE) is the most pivotal tool to detect gastric cancer in an early stage. However, the skill among endoscopists varies greatly. Here, we aim to develop a deep learning-based system named ENDOANGEL-LD (lesion detection) to assist in detecting all focal gastric lesions and predicting neoplasms by WLE.

METHODS

Endoscopic images were retrospectively obtained from Renmin Hospital of Wuhan University (RHWU) for the development, validation, and internal test of the system. Additional external tests were conducted in 5 other hospitals to evaluate the robustness. Stored videos from RHWU were used for assessing and comparing the performance of ENDOANGEL-LD with that of experts. Prospective consecutive patients undergoing upper endoscopy were enrolled from May 6, 2021 to August 2, 2021 in RHWU to assess clinical practice applicability.

RESULTS

Over 10,000 patients undergoing upper endoscopy were enrolled in this study. The sensitivities were 96.9% and 95.6% for detecting gastric lesions and 92.9% and 91.7% for diagnosing neoplasms in internal and external patients, respectively. In 100 videos, ENDOANGEL-LD achieved superior sensitivity and negative predictive value for detecting gastric neoplasms from that of experts (100% vs 85.5% ± 3.4% [P = .003] and 100% vs 86.4% ± 2.8% [P = .002], respectively). In 2010 prospective consecutive patients, ENDOANGEL-LD achieved a sensitivity of 92.8% for detecting gastric lesions with 3.04 ± 3.04 false positives per gastroscopy and a sensitivity of 91.8% and specificity of 92.4% for diagnosing neoplasms.

CONCLUSIONS

Our results show that ENDOANGEL-LD has great potential for assisting endoscopists in screening gastric lesions and suspicious neoplasms in clinical work. (Clinical trial registration number: ChiCTR2100045963.).

Deep learning system compared with expert endoscopists in predicting early gastric cancer and its invasion depth and differentiation status (with videos)

BACKGROUND AND AIMS

We aimed to develop and validate a deep learning-based system that covers various aspects of early gastric cancer (EGC) diagnosis, including detecting gastric neoplasm, identifying EGC, and predicting EGC invasion depth and differentiation status. Herein, we provide a state-of-the-art comparison of the system with endoscopists using real-time videos in a nationwide human-machine competition.

METHODS

This multicenter, prospective, real-time, competitive comparative, diagnostic study enrolled consecutive patients who received magnifying narrow-band imaging endoscopy at the Peking University Cancer Hospital from June 9, 2020 to November 17, 2020. The offline competition was conducted in Wuhan, China, and the endoscopists and the system simultaneously read patients' videos and made diagnoses. The primary outcomes were sensitivity in detecting neoplasms and diagnosing EGCs.

RESULTS

One hundred videos, including 37 EGCs and 63 noncancerous lesions, were enrolled; 46 endoscopists from 44 hospitals in 19 provinces in China participated in the competition. The sensitivity rates of the system for detecting neoplasms and diagnosing EGCs were 87.81% and 100%, respectively, significantly higher than those of endoscopists (83.51% [95% confidence interval [CI], 81.23-85.79] and 87.13% [95% CI, 83.75-90.51], respectively). Accuracy rates of the system for predicting EGC invasion depth and differentiation status were 78.57% and 71.43%, respectively, slightly higher than those of endoscopists (63.75% [95% CI, 61.12-66.39] and 64.41% [95% CI, 60.65-68.16], respectively).

CONCLUSIONS

The system outperformed endoscopists in identifying EGCs and was comparable with endoscopists in predicting EGC invasion depth and differentiation status in videos. This deep learning-based system could be a powerful tool to assist endoscopists in EGC diagnosis in clinical practice.

CircPDZD8 promotes gastric cancer progression by regulating CHD9 via sponging miR-197-5p

CircRNAs have been shown to be associated with gastric cancer tumorigenesis. But little was known about the role of circPDZD8 in gastric cancer. CircPDZD8 was up-regulated in gastric cancer tissues and cells, Kaplan-Meier survival analysis indicated that gastric patients had a poor overall survival when circPDZD8 levels were high. CircPDZD8 knockdown could hinder proliferation and migration of gastric cancer cells. MiR-197-5p, which was down-regulated in gastric cancer, was shown to be a target of circPDZD8 and was inversely correlated with circPDZD8 expression. CHD9, as a target gene of miR-197-5p, was negatively regulated by miR-197-5p and positively correlated with circPDZD8 expression. Importantly, circPDZD8 could up-regulate CHD9 expression by sponging miR-197-5p, and modulate cell progression by regulation of the miR-197-5p/CHD9 axis in gastric cancer. CircPDZD8 knockdown repressed the progression of gastric cancer cells by sponging miR-197-5p and down-regulating CHD9.

UKCGG Consensus Group guidelines for the management of patients with constitutional TP53 pathogenic variants

Constitutional pathogenic variants in TP53 are associated with Li-Fraumeni syndrome or the more recently described heritable TP53-related cancer syndrome and are associated with increased lifetime risks of a wide spectrum of cancers. Due to the broad tumour spectrum, surveillance for this patient group has been limited. To date, the only recommendation in the UK has been for annual breast MRI in women; however, more recently, a more intensive surveillance protocol including whole-body MRI (WB-MRI) has been recommended by International Expert Groups. To address the gap in surveillance for this patient group in the UK, the UK Cancer Genetics Group facilitated a 1-day consensus meeting to discuss a protocol for the UK. Using a preworkshop survey followed by structured discussion on the day, we achieved consensus for a UK surveillance protocol for TP53 carriers to be adopted by UK Clinical Genetics services. The key recommendations are for annual WB-MRI and dedicated brain MRI from birth, annual breast MRI from 20 years in women and three-four monthly abdominal ultrasound in children along with review in a dedicated clinic.

SEOM clinical guideline for the diagnosis and treatment of gastric cancer (GC) and gastroesophageal junction adenocarcinoma (GEJA) (2019)

Gastric cancer (GC) is the fifth most common cancer worldwide with a varied geographic distribution and an aggressive behavior. In Spain, it represents the sixth cause of cancer death. In Western countries, the incidence is decreasing slightly, with an increase in gastroesophageal junction adenocarcinoma (GEJA), a different entity that we separate specifically in the guideline. Molecular biology advances have been done recently, but do not yet lead to the choice in treatment approach except in advanced disease with overexpression of HER2. Endoscopic resection in very early stage, perioperative chemotherapy in locally advanced tumors and preliminary immune therapy resulting in advanced disease are the main treatment innovations in the GC/GEJA treatment. We describe the different evidences and recommendations following the statements of the American College of Physicians.

Nomogram for predicting the survival of gastric adenocarcinoma patients who receive surgery and chemotherapy

Background

Surgery is the only way to cure gastric adenocarcinoma (GAC), and chemotherapy is the basic adjuvant management for GAC. A significant prognostic nomogram for predicting the respective disease-specific survival (DSS) rates of GAC patients who receive surgery and chemotherapy has not been established.

Objective

We were planning to establish a survival nomogram model for GAC patients who receive surgery and chemotherapy.

Methods

We identified 5764 GAC patients who had received surgery and chemotherapy from the record of Surveillance, Epidemiology, and End Results (SEER) database. About 70% (n = 4034) of the chosen GAC patients were randomly assigned to the training set, and the rest of the included ones (n = 1729) were assigned to the external validation set. A prognostic nomogram was constructed by the training set and the predictive accuracy of it was validated by the validation set.

Results

Based on the outcome of a multivariate analysis of candidate factors, a nomogram was developed that encompassed age at diagnosis, number of regional lymph nodes examined after surgery, number of positive regional lymph nodes, sex, race, grade, derived AJCC stage, summary stage, and radiotherapy status. The C-index (Harrell’s concordance index) of the nomogram model was some larger than that of the traditional seventh AJCC staging system (0.707 vs 0.661). Calibration plots of the constructed nomogram displayed that the probability of DSS commendably accord with the survival rate. Integrated discrimination improvement (IDI) revealed obvious increase and categorical net reclassification improvement (NRI) showed visible enhancement. IDI for 3-, 5- and 10- year DSS were 0.058, 0.059 and 0.058, respectively (P > 0.05), and NRI for 3-, 5- and 10- year DSS were 0.380 (95% CI = 0.316–0.470), 0.407 (95% CI = 0.350–0.505), and 0.413 (95% CI = 0.336–0.519), respectively. Decision curve analysis (DCA) proved that the constructed nomogram was preferable to the AJCC staging system.

Conclusion

The constructed nomogram supplies more credible DSS predictions for GAC patients who receive surgery and chemotherapy in the general population. According to validation, the new nomogram will be beneficial in facilitating individualized survival predictions and useful when performing clinical decision-making for GAC patients who receive surgery and chemotherapy.

BRAZILIAN GASTRIC CANCER ASSOCIATION GUIDELINES (PART 1): AN UPDATE ON DIAGNOSIS, STAGING, ENDOSCOPIC TREATMENT AND FOLLOW-UP

BACKGROUND

The II Brazilian Consensus on Gastric Cancer by the Brazilian Gastric Cancer Association (ABCG) was recently published. On this occasion, several experts in gastric cancer expressed their opinion before the statements presented.

AIM

To present the ABCG Guidelines (part 1) regarding the diagnosis, staging, endoscopic treatment and follow-up of gastric cancer patients.

METHODS

To forge these Guidelines, the authors carried out an extensive and current review regarding each statement present in the II Consensus, using the Medline/PubMed, Cochrane Library and SciELO databases with the following descriptors: gastric cancer, staging, endoscopic treatment and follow-up. In addition, each statement was classified according to the level of evidence and degree of recommendation.

RESULTS

Of the 24 statements, two (8.3%) were classified with level of evidence A, 11 (45.8%) with B and 11 (45.8%) with C. As for the degree of recommendation, six (25%) statements obtained grade of recommendation 1, nine (37.5%) recommendation 2a, six (25%) 2b and three (12.5%) grade 3.

CONCLUSION

The guidelines presented here are intended to assist professionals working in the fight against gastric cancer with relevant and current information, granting them to be applied in the daily medical practice.

Gastric Cancer Peritoneal Carcinomatosis Risk Score

BACKGROUND

Gastric cancer (GC) peritoneal carcinomatosis (PC) is associated with a poor prognosis. Although grade, histology, and stage are associated with PC, the cumulative risk of PC when multiple risk factors are present is unknown. This study aimed to develop a cumulative GCPC risk score based on individual demographic/tumor characteristics.

METHODS

Patient-level data (2004-2014) from the California Cancer Registry were reviewed by creating a keyword search algorithm to identify patients with gastric PC. Multivariable logistic regression was used to assess demographic/tumor characteristics associated with PC in a randomly selected testing cohort. Scores were assigned to risk factors based on beta coefficients from the logistic regression result, and these scores were applied to the remainder of the subjects (validation cohort). The summed scores of each risk factor formed the total risk score. These were grouped, showing the percentages of patients with PC.

RESULTS

The study identified 4285 patients with gastric adenocarcinoma (2757 males, 64.3%). The median age of the patients was 67 years (interquartile range [IQR], 20 years). Most of the patients were non-Hispanic white (n = 1748, 40.8%), with proximal (n = 1675, 39.1%) and poorly differentiated (n = 2908, 67.9%) tumors. The characteristics most highly associated with PC were T4 (odds ratio [OR], 3.12; 95% confidence interval [CI], 2.19-4.44), overlapping location (OR 2.27; 95% CI 1.52-3.39), age of 20-40 years (OR 3.42; 95% CI 2.24-5.21), and Hispanic ethnicity (OR 1.86; 95% CI 1.36-2.54). The demographic/tumor characteristics used in the risk score included age, race/ethnicity, T stage, histology, tumor grade, and location. Increasing GCPC score was associated with increasing percentage of patients with PC.

CONCLUSION

Based on demographic/tumor characteristics in GC, it is possible to distinguish groups with varying odds for PC. Understanding the risk for PC based on the cumulative effect of high-risk features can help clinicians to customize surveillance strategies and can aid in early identification of PC.

Efficacy and safety of intensity-modulated radiation therapy versus three-dimensional conformal radiation treatment for patients with gastric cancer: a systematic review and meta-analysis

BACKGROUND

Radiation or radiochemotherapy is a common adjuvant therapy for gastric cancer. Intensity-modulated radiation therapy (IMRT) has been demonstrated to provide better dose conformity, allowing dose escalation and/or reduction of normal tissue exposure compared with three-dimensional conformal radiation treatment (3D-CRT). However, the efficacy of IMRT and 3D-CRT in gastric cancer remains controversial. This study aimed to compare the efficacy and safety of IMRT with those of 3D-CRT in treating patients with gastric cancer through conducting a meta-analysis of 3-year survival rates [overall survival (OS) and disease-free survival (DFS)], local control rates, and toxic event rates.

METHODS

Embase, PubMed, the Cochrane Library, and clinical trial databases were searched to identify the clinical trials of IMRT versus 3D-CRT for treating patients with gastric cancer. The obtained data of survival and safety were analyzed using the Stata 14.0 software.

RESULTS

A total of 9 controlled clinical studies, including 516 patients with gastric cancer, met the inclusion criteria and were included in this meta-analysis. The results of the meta-analysis showed that the 3-year OS rate was slightly higher in the IMRT group than in the 3D-CRT group, without any statistical significance. The 3-year local control rate was significantly higher in the IMRT group than in the 3D-CRT group. No significant difference in the 3-year DFS rate was found between the IMRT and 3D-CRT groups. Grade 2-4 toxicities were similar between the IMRT and 3D-CRT groups.

CONCLUSION

The findings suggested that IMRT might be superior to 3D-CRT in treating patients with gastric cancer in terms of local control rates without increasing toxicity.

ELK1-induced upregulation of lncRNA TRPM2-AS promotes tumor progression in gastric cancer by regulating miR-195/ HMGA1 axis

Long noncoding RNAs (lncRNAs) have been confirmed to be aberrantly expressed in various diseases including tumors. Recently, a new tumor-related lncRNA, lncRNA TRPM2 antisense RNA (TRPM2-AS), was shown to be involved in many tumors, such as lung cancer and breast cancer. However, the expression and role of TRPM2-AS in the development of gastric cancer (GC) have not been elucidated. In the current study, we provided evidence that the expression levels of TRPM2-AS were increased in both GC tissues and cell lines. We also showed that overexpression of TRPM2-AS was modulated by ELK1, a transcription factor. The results of clinical assays showed that higher expressions of TRPM2-AS were significantly related with invasion depth, TNM stage, lymphatic metastasis, and shorter overall survival. Further clinical assays using multivariate analysis suggested that TRPM2-AS expression was an independent prognostic factor in patients with GC. Functional experiments illustrated that depression of TRPM2-AS suppressed proliferation, migration, and invasion in GC cells. In terms of mechanism, we found that TRPM2-AS directly inhibited miR-195, which targeted the 3'-untranslated region of high-mobility group AT-hook 1 (HMGA1) messenger RNA. Overall, these findings revealed that ELK1-induced overexpression of TRPM2-AS promoted the development and progression of GC in part through miR-195/HMGA1 signaling axis, and established its candidacy as a new cancer biomarker for GC patients.

DNA aptamers from whole-serum SELEX as new diagnostic agents against gastric cancer

Gastric cancer is still among the leading causes of cancer deaths worldwide. Despite the improvements in diagnostic methods, the status of early detection has not been achieved so far. Early diagnosis of gastric cancer may significantly improve the cure rate of patients. Therefore, a new diagnostic method is needed. In this study, subtractive SELEX was performed to screen gastric cancer serum-specific DNA aptamers by using gastric cancer serum and normal serum as the target and negative serum, respectively. Four highly specific aptamers generated for gastric cancer serum, Seq-3, Seq-6, Seq-19 and Seq-54, were developed using whole-serum subtractive SELEX technology with K_d of 128 ± 26.3 nM, 149 ± 23.6 nM, 232 ± 44.2 nM, 202 ± 25.6 nM, respectively. These generated aptamers showed higher specificities toward their target serum by differentiating normal serum but closely related other cancer serums. The selected four high affinity DNA aptamers were further applied to the development based on qPCR method for the early detection of gastric cancer. In addition, we performed MALDI-TOF MS followed by secondary peptide sequencing MS analysis for the identification of the aptamer binding proteins. Among these potential biomarkers, APOA1, APOA4, PARD3, Importin subunit alpha-1 showed a relatively high score probability. Therefore, these four ssDNA aptamers generated in our study could be a promising molecular probe for gastric cancer diagnosis.

Gastric cancer is still among the leading causes of cancer deaths worldwide.