Tracking of trastuzumab resistance in patients with HER2-positive metastatic gastric cancer by CTC liquid biopsy.

This study aimed to utilize circulating tumor cell-DNA (CTC-DNA) from liquid biopsies to monitor trastuzumab resistance in Gastric cancer (GC) and assess the limited response rate in HER2 metastatic gastric cancer. Given the heterogeneity of GC, we established a high-precision CTC detection system that effectively isolates tumor cells with high HER2 expression for downstream analysis. Targeted sequencing of 610 genes was conducted on 20 paired CTC and tissue samples to assess uniformity. A longitudinal analysis of CTC samples was then performed to monitor trastuzumab resistance throughout treatment. Targeted sequencing of the HER2 gene showed strong consistency with fluorescence in situ hybridization data. Detected HER2 Scna was superior in predicting tumor shrinkage and progression. Most patients with innate trastuzumab resistance exhibited elevated HER2 Scna levels during progression. PIK3CA mutations were significantly enriched, and ERBB2/4 gene mutations were predominant in patients with innate trastuzumab resistance. CTC-DNA sequencing provides new insights into gene alterations associated with trastuzumab resistance in HER2 mGC.

ZEB1-induced LINC01559 expedites cell proliferation, migration and EMT process in gastric cancer through recruiting IGF2BP2 to stabilize ZEB1 expression.

Gastric cancer (GC) is a common type of tumor that is characterized with high metastatic rate. In recent years, increasing studies have indicated that lncRNAs are involved in the regulation on cancer cell proliferation and migration. However, the functional role of long intergenic non-protein coding RNA 1559 (LINC01559) in GC is still unclear. In this study, we applied quantitative real-time polymerase chain reaction (RT-qPCR) and examined that LINC01559 expression was significantly enhanced in GC cells. Functional assays such as EdU, colony formation, JC-1 and transwell assays displayed that silencing LINC01559 inhibited cell proliferation and migration while promoted cell apoptosis in GC. Besides, western blot analysis and immunofluorescence assays examined the expression of factors related to epithelial-mesenchymal transition (EMT) and indicated that EMT process was blocked by LINC01559 knockdown in GC cells. Besides, LINC01559 silencing inhibited tumor growth in vivo. In addition, Chromatin immunoprecipitation (ChIP) assays demonstrated that zinc finger E-box binding homeobox 1 (ZEB1) served as a transcription factor to combine with LINC01559 promoter and activated the expression of LINC01559 in GC cells. In return, LINC01559 recruited insulin like growth factor 2 mRNA binding protein 2 (IGF2BP2) to stabilize ZEB1 mRNA to up-regulate ZEB1 in GC cells. In short, the findings in this research might provide a novel target for GC treatment.

The long non-coding RNA MEG3 plays critical roles in the pathogenesis of cholesterol gallstone.

BACKGROUND: Cholesterol gallstone (CG) is the most common gallstone disease, which is induced by biliary cholesterol supersaturation. The purpose of this study is to investigate the pathogenesis of CG. METHODS: Sixteen mice were equally and randomly divided into model group and normal control group. The model group was fed with lithogenic diets to induce CG, and then gallbladder bile lipid analysis was performed. After RNA-seq library was constructed, differentially expressed mRNAs (DE-mRNAs) and differentially expressed lncRNAs (DE-lncRNAs) between model group and normal control group were analyzed by DESeq2 package. Using the cluster Profiler package, enrichment analysis for the DE-mRNAs was carried out. Based on Cytoscape software, the protein-protein interaction (PPI) network and competing endogenous RNA (ceRNA) network were built. Using quantitative real-time reverse transcription-PCR (qRT-PCR) analysis, the key RNAs were validated. RESULTS: The mouse model of CG was suc cessfully established, and then 181 DE-mRNAs and 33 DE-lncRNAs between model and normal groups were obtained. Moreover, KDM4A was selected as a hub node in the PPI network, and lncRNA MEG3 was considered as a key lncRNA in the regulatory network. Additionally, the miR-107-5p/miR-149-3p/miR-346-3-MEG3 regulatory pairs and MEG3-PABPC4/CEP131/NUMB1 co-expression pairs existed in the regulatory network. The qRT-PCR analysis showed that KDM4A expression was increased, and the expressions of MEG3, PABPC4, CEP131, and NUMB1 were downregulated. CONCLUSION: These RNAs might be related to the pathogenesis of CG.

HOTAIR contributes to the carcinogenesis of gastric cancer via modulating cellular and exosomal miRNAs level.

Gastric cancer (GC) is one of the most leading malignancies. Long noncoding RNA is related to GC. In this study, 11 miRNAs in the exosomes and six lncRNAs in the tissues was examined by qRT-PCR. Correlation analysis was used to analyze the relationship between miRNAs in exosome and lncRNAs in the tissues. Four miRNAs level in GC tissues were examined by qRT-PCR. MTT was used to determine cell viability. Flow cytometry was used to quantify the apoptotic cells. Transwell assay was used to examine the migration and invasion capacity. Dual-luciferase assay was used to examine the interaction between HOTAIR and miR-30a or -b. Capillary formation was used to determine the capillary formation capacity. Weak negative correlations were found between HOTAIR and miR-30a or -b in GC tissue samples. Interestingly, strong negative correlations were identified between the HOTAIR level in GC tissue samples and the miR-30a or -b levels in plasma exosomes. HOTAIR knockdown GC cells exhibited decreased migration, invasion, proliferation, and upregulated apoptosis, which released more miR-30a and -b into the exosomes. KRAS was upregulated when co-cultured with exosomes from HOTAIR overexpressed cells, and promoted GC cells proliferation, migration, and invasion. Meanwhile, HUVEC cells expressed increased VEGF-A and formatted more capillaries. Subsequently, we identified a 10mer target site of miR-30a or -b in HOTAIR sequence, and the overexpression of HOTAIR induced the degradation of miR-30a or -b, indicating a ceRNA role of HOTAIR. We report the negative correlation between the plasma miRNAs level and GC tissue HOTAIR expression for the first time and unveiled the ceRNA role of HOTAIR in GC. HOTAIR functions as an onco-lncRNA regulating the level of miR-30a and -b in both GC cells and exosomes. These findings may give insight into understanding the mechanism of GC pathogenesis and provide new biomarkers for clinical diagnosis.

Knockdown of TRIM37 Promotes Apoptosis and Suppresses Tumor Growth in Gastric Cancer by Inactivation of the ERK1/2 Pathway.

OBJECTIVE: Gastric cancer (GC), a malignant tumor of the gastric mucosa, is the second leading cause of cancer deaths worldwide. Although the incidence and mortality of gastric cancer have been reduced in the US and elsewhere, it is still a major public health concern. In this study, we attempted to investigate the function of tripartite motif-containing protein 37 (TRIM37) in GC cell lines in order to propose a new therapy for GC. METHODS: The expression of TRIM37 in GC patients and cell lines was detected by immunohistochemistry, real-time PCR and Western blotting analysis. After TRIM37 knockdown or overexpression, the cell cycle, proliferation and apoptosis, as well as the expression of related proteins, were detected. In addition, in vivo experiments on nude mice were performed. RESULTS: We found that TRIM37 expression was significantly elevated in tumor tissues of GC patients and GC cell lines, and patients with high expression of TRIM37 had a poor prognosis. Knockdown of TRIM37 in GC cells significantly inhibited cell proliferation and cell cycle progression, promoted apoptosis, increased cleaved caspase 3 and decreased c-myc and phosphorylation of protein kinase 1/2 (p-ERK1/2). Effects of TRIM37 overexpression were opposite to that of TRIM37 knockdown and were potently attenuated by an ERK1/2 inhibitor. In addition, an ERK1/2 agonist increased TRIM37 and p-ERK1/2 in a dose-dependent manner, and TRIM37 knockdown potently attenuated EGF-induced cell proliferation and expression of TRIM37 and p-ERK1/2. Interestingly, we found that TRIM37 overexpression did not affect the mRNA level of dual-specificity phosphatase 6 (DUSP6), but reduced its protein level in GC cells. Co-immunoprecipitation (Co-IP) analyses revealed that TRIM37 interacted with DUSP6, and TRIM37 overexpression enhanced DUSP6 ubiquitination in GC cells. In vivo experiments on nude mice showed the inhibitory effect of TRIM37 knockdown on tumor growth. CONCLUSION: These findings suggest that TRIM37 may act as an oncogene in the growth of GC cells and illustrate its potential function as a target in the treatment of GC.

Design, synthesis of novel C-3'-N-sulfonyl modified taxane analogues from 1-deoxybaccatin VI and their impact on anti-HCC activity.

A new series of C-3'-N-sulfonyl paclitaxel analogs were designed and synthesized from 1-deoxybaccatin VI and their structures were confirmed by 1H NMR, 13C NMR and high resolution MS. The synthesized compounds were evaluated for their in vitro anti-Hepatocellular carcinoma (HCC) activity against human hepatoma (HepG2) cell line. Bioassay results showed that compounds 17c, 17d and 17f exhibited more potent inhibitory activity against HepG2 cell line in comparison with paclitaxel. It is suggested that paclitaxel analogs containing the C-3'-N-sulfonyl could be considered as a precursor structure for further synthesis of more potent analogues.

Genomic alterations in gastric cancers discovered via whole-exome sequencing.

BACKGROUND: Gastric cancer (GC) ranks the second in mortality rate among all cancers. Metastases account for most of the deaths in GC patients. Yet our understanding of GC and its metastasis mechanism is still very limited. METHODS: We performed 20 whole-exome sequencing (WES) on 5 typical metastatic gastric adenocarcinoma (GAC) patients with lymph node metastasis. We compared both the primary tumors to their metastatic lymph nodes, and a specific analysis pipeline was used to detect single nucleotide variants (SNVs), small insertions/deletions (indels) and copy number variants (CNVs). RESULTS: (1) We confirmed 30 candidate mutations in both primary and lymph nodes tissues, and other 7 only in primary tumors. (2) Copy number gains were observed in a large section of 17q12-21, as well as copy number losses in regions containing CDKN2A and CDKN2B in both primary and lymph nodes tissues. CONCLUSIONS: Our results provide preliminary insights in the molecular mechanisms of GC initiation, development, and metastatic progression. These results need to be validated through large-scale studies.

Down regulation of miR-148a is related to enhanced pancreatic cancer pathogenesis through targeting GLUT1.

Pancreatic cancer (PC) is an aggressive malignancy with one of the worst mortality rates in the world. Multiple factors, including a complex and poorly understood pathophysiology and difficulty in early detection and diagnosis make successful treatment of pancreatic cancer extremely challenging. In this study, we first detected the expressions of eight selected miRNAs which are predicted repress GLUT1 expression by targeting 3'UTR. We found miR-148a had a significantly down regulated expression and miR-148a level has an inverse correlation with the expression of GLUT1 in PC tissues. Subsequently, examined by dual-luciferase assay and western blot, we confirmed that miR-148a suppressed GLUT1 expression by directly targeting 3'UTR of GLUT1 mRNA. Finally, biological study in two pancreatic cancer cell lines indicates that miR-148a function as a tumor suppressor gene through repressing pancreatic cancer cell proliferation, migration and invasion. We first identified miR-148a, which has down regulated expression in pancreatic cancer tissues, plays as a cancer inhibitor through targeting GLUT1. This study sheds light on the roles of miRNAs in the pathogenesis of pancreatic cancer and may be helpful for clinical diagnosis and treatment.

Synthesis and biological evaluation of novel A-seco-taxoids derived from 1-deoxybaccatin VI.

Three novel nor-seco-taxoids 13, 15, 23 in which the A rings are cleaved but the B, C, and D rings are retained were prepared from 1-deoxybaccatin VI via its nor-dioxo derivative and their structures were confirmed by 1H NMR, 13C NMR and high resolution MS. Oxidative introduction of C-1 hydroxyl to 1-deoxybaccatin VI with oxidising agent KBrO3 and catalyst RuCl3 led to the dioxo derivative 6 and its structure is determined by X-ray crystallographic analysis. A-seco taxoids 13, 15, 23 with a C-13 ester linkage were tested for cytotoxic activity and all compounds showed no measurable cytotoxic activity against HCT-116 cell line. However, 1-deoxy-9a-dihydrotaxane analogue 4 semi-synthesised from 1-deoxybaccatin VI is 10-fold less cytotoxic than paclitaxel, indicating the indispensible nature of the A ring double bond for the bioactivity of paclitaxel.

SENP1 attenuates the liver fibrosis through down-regulating the expression of SMAD2.

To investigate whether SENP1 could play a regulating role in the liver fibrosis process, the Sprague-Dawley (SD) rats were used to establish the liver fibrosis rat models by intraperitoneally injecting with 1 ml/kg of 10% CCl4, while the control normal rats were injected with olive oil. Then confirmation experiments to verify the successful establishment of these models were conducted by detecting the cellular and lobular architecture, and liver function indexes using hematoxylin-eosin staining, Masson's trichrome staining and microplate method, respectively. In addition, the expression levels of fibrosis markers including collagen I, collagen III, α-SMA and TGF-ß1 were inspected using quantitative real-time PCR (qRT-PCR), as well as SMAD2. Subsequently, the relative mRNA and protein level of SENP1 was also determined via qRT-PCR and western blot analysis. Next, the HSC-T6 cells of SENP1 knock-down were constructed and used to test the relative protein expression levels of α-SMA and SMAD2 in these cells. The results of hematoxylin-eosin staining, Masson's trichrome staining and microplate method turned out that the rat liver fibrosis models were constructed successfully, which was further confirmed by the increased expression of collagen I, collagen III, α-SMA and TGF-ß1 in mRNA and protein level, as well as SMAD2. Then the expression of SENP1 was overexpressed in the rat liver fibrosis models induced by CCl4 and the TGF-ß1 treatment could increase the protein expression level of collagen I, collagen III and α-SMA. Lastly, the SENP1 knockdown HSC-T6 cells were successfully constructed, while the silence of SENP1 down-regulated the protein expression of α-SMA and SMAD2. In conclusion, this study provided a new regulation mechanism about the liver fibrosis process.

Gastrointestinal stromal tumor: 15-years' experience in a single center.

BACKGROUND: Gastrointestinal stromal tumor (GIST) is known for its wide variability in biological behaviors and it is difficult to predict its malignant potential. The aim of this study is to explore the characteristics and prognostic factors of GIST. METHODS: Clinical and pathological data of 497 GIST patients in our center between 1997 and 2012 were reviewed. RESULTS: Patients were categorized into very low-, low-, intermediate- and high-risk groups according to modified National Institutes of Health (NIH) consensus classification system. Among the 401 patients untreated with imatinib mesylate (IM), 5-year overall survival (OS) in very low-, low-, intermediate- and high-risk groups was 100%, 100%, 89.6% and 65.9%; and 5-year relapse-free survival (RFS) was 100%, 98.1%, 90.9% and 44.5%, respectively. Univariate analysis revealed that sex, tumor size, mitotic rate, risk grade, CD34 expression, and adjacent involvement were predictors of OS or RFS. COX hazard proportional model (Forward LR) showed that large tumor size, high mitotic rate, and high risk grade were independent risk factors to OS, whereas high mitotic rate, high risk grade and adjacent organ involvement were independent risk factors to RFS. The intermediate-high risk patients who received IM adjuvant therapy (n = 87) had better 5-year OS and RFS than those who did not (n = 188) (94.9% vs. 72.1; 82.3% vs. 56.3%, respectively). Similarly, advanced GIST patients underwent IM therapy (n = 45) had better 3-year OS and 1-year progression-free survival (PFS) than those who didn't (n = 42) (75.6% vs. 6.8%; 87.6% vs. 12.4%, respectively). CONCLUSIONS: Very low- and low-risk GISTs can be treated with surgery alone. Large tumor size, high mitotic rate, high risk grade, and adjacent organ involvement contribute to the poor outcome. IM therapy significantly improves the survival of intermediate-high risk or advanced GIST patients.

Prognostic value of mutational characteristics in gastrointestinal stromal tumors: a single-center experience in 275 cases.

The objective of this study was to investigate the impact of KIT/PDGFRA mutations on the prognosis of gastrointestinal stromal tumors (GISTs). In the present study, genotype analyses were performed based on GIST samples from 275 patients. The relationship between mutation and clinicopathological characteristics were explored. All factors were evaluated for their impacts on relapse-free survival (RFS). Briefly, the results of genotype analyses showed that mutations were identified in 258 (93.8 %) patients, and deletion was the most frequent type of mutation accounting for 47.3 % (122/258) of all mutation cases, followed by substitution (87/258, 33.7 %) and duplication (49/258, 19.0 %). Moreover, for KIT exon 11 mutation, the most frequently involved area was from codon 557 to 560. Deep analyses showed that the mutation types were correlated with tumor location (P = 0.005), tumor size (P = 0.022), mitosis rate (P < 0.001), risk grade (P < 0.001), and relapse (P = 0.004). Furthermore, delW557-K558 correlated with mitosis rate (P = 0.042) and relapse (P = 0.036), and delTyr568/570 correlated with tumor origin (P = 0.018). Most importantly, mitotic rate [HR = 2.901 (95 % CI 1.094-7.695), P = 0.032] and risk grade [HR = 9.629 (95 % CI 1.997-46.416), P = 0.005] would be the representative traditional prognostic factors, and deletion with >3 codons would be an novel independent predictor of poor outcome for RFS in GIST patients with deletion mutation of KIT exon 11 [HR = 7.970 (95 % CI 1.774-35.803), P = 0.007]. All results indicated that mutation determined clinicopathological features and prognosis of GISTs, and more than three codons involvement may be a novel adverse indicator.

[Clinicopathological features and management of gastrointestinal stromal tumors complicated with synchronous other alimentary malignant tumor].

OBJECTIVE: To explore the clinicopathologic features, treatment and prognosis of gastrointestinal stromal tumor (GIST) complicated with synchronous other alimentary malignant tumors. METHODS: Clinical data of 525 patients with GIST undergoing surgical treatment from August 2004 to November 2012 in Shanghai Renji Hospital were reviewed retrospectively, among whom 46 patients presented synchronous other alimentary malignancy. RESULTS: GIST and other alimentary malignancy coexisting cases were less likely to be screened out preoperatively (2.2%, 1/46) and associated with elder age (P=0.001), more likely arise from stomach (P=0.000), smaller tumor maximum diameter (P=0.000), and lower mitotic count (P=0.000). According to NIH postoperative risk classification, there were 36 at very low risk, 9 at low risk, and 1 at high risk. Although the risk of GIST recurrence was lower for GIST and other alimentary malignancy coexisting cases, their 5-year survival rate was lower than that of patients with GIST alone (36.1%VS. 82.2%, P=0.000). CONCLUSIONS: GIST patients complicated with synchronous alimentary malignant tumor are usually low or very low risk and has minimal impact on the prognosis. Survival depends primarily on the synchronous alimentary malignant tumors. Therefore, it is reasonable to lay emphasis on the treatment of the alimentary malignant tumor, and perform synchronous resection of GIST if possible.

[Clinical analysis of laparoscopic and endoscopic cooperative surgery in the treatment of gastric gastrointestinal stromal tumor: report of 46 cases].

OBJECTIVE: To evaluate the feasibility and safety of laparoscopic and endoscopic cooperative surgery for treating gastric gastrointestinal stromal tumors(GIST). METHODS: Retrospective analysis was performed on the clinical data of 46 patients with gastric GIST undergoing laparoscopic and endoscopic cooperative surgery between June 2009 and June 2011 at the Renji Hospital of Shanghai Jiaotong University School of Medicine. RESULTS: There were 27 males and 19 females with the mean age of 58.5 years. Thirty-three patients received endoscopy-assisted wedge resection, and 13 cases received laparoscopy-assisted endoscopic resection. All the operations were successful. The mean operative time was (85.5±29.3) min, the mean blood loss was (31.4±12.2) ml, the mean post-operative gastrointestinal functional recovery time was (31.6±14.9) h, and the mean post-operative hospital stay was (5.1±2.9) d. No post-operative complication occurred. NIH risk assessment showed that 34 cases were very low risk and 12 low risk. No recurrence or metastasis was found during the follow-up ranging from 2 to 26 months(median, 12.6 months). CONCLUSION: Laparoscopic and endoscopic cooperative surgery for gastric GIST is both feasible and safe with minimal invasiveness, fast recovery and satisfactory short-term outcomes.