Proapoptotic effect of WS-299 induced by NOXA accumulation and NRF2-counterbalanced oxidative stress damage through targeting RBX1-UBE2M interaction in gastric cancers

The abnormal activation of Cullin RING E3 Ligases (CRLs) is closely associated with the occurrence and development of various cancers. Targeting the neddylation pathway represents an effective approach for cancer treatment. In this work, we reported that WS-299, structurally featuring a coumarin moiety attached to the triazolopyrimidine, exhibited excellent anti-proliferative activity in MGC-803 and HGC-27 cells. WS-299 exerted potent anticancer effects by inhibiting clone formation, EdU incorporation and inducing cell cycle arrest. WS-299 inhibited CUL3/5 neddylation and caused an obvious accumulation of Nrf2 and NOXA, substrates of CRL3 and CRL5, respectively. Biochemical studies showed that WS-299 inhibited CUL3 neddylation by inhibiting RBX1-UBE2M interaction. The anti-proliferative effect of WS-299 was mainly induced by NOXA-mediated apoptosis. Of note, Nrf2 attenuated WS-299-induced reactive oxygen species (ROS) levels. Furthermore, Nrf2 accumulation also had an antagonistic effect on NOXA-induced apoptosis. Therefore, WS-299 and siNrf2 synergistically increased ROS levels, apoptotic cells and suppressed tumor growth in vivo. Taken together, our research clarified the anti-cancer mechanisms of WS-299 through targeting the RBX1-UBE2M protein-protein interaction and inhibiting the neddylation modification of CUL3 and CUL5. More importantly, our studies also demonstrated that combination of WS-299 with shNrf2 could be an effective strategy for treating gastric cancers.

Clinicopathological Study of Lesions of Upper Gastrointestinal Tract

Conditions affecting the upper digestive system are often seen in clinical practice and are associated with a high rate of death and disability. Histopathological confirmation is one of the foundations for good treatment planning and the definite diagnosis of illnesses of the upper gastrointestinal tract. The numerous methods employed in the diagnosis of gastrointestinal lesions have come a long way in the previous 25 years. The identification and diagnosis of gastrointestinal lesions have been substantially aided by the development of endoscopy, endoscopic biopsy, and other surgical techniques. This research aimed to examine the variety of gastrointestinal tract (GI) lesions and to draw connections between the clinical and pathological manifestations of these conditions.

Materials and Methods

A two-year cross-sectional study was conducted in the Department of Pathology, from June 2018 to May 2020, which included surgical specimens of 140 cases from the upper gastrointestinal tract, of which 111 cases were biopsy, and 29 cases were resected surgical specimens. The data were analyzed using SPSS software. Furthermore, P values, sensitivity, specificity, positive predictive value, and negative predictive value were calculated.

Results

This study was a two-year cross-sectional study conducted in the Department of Pathology during the period of June 2018-May 2020.

Helicobacter pylori plays a key role in gastric adenocarcinoma induced by spasmolytic polypeptide-expressing metaplasia

Heliobacter pylori (H. pylori), a group 1 human gastric carcinogen, is significantly associated with chronic gastritis, gastric mucosal atrophy, and gastric cancer. Approximately 20% of patients infected with H. pylori develop precancerous lesions, among which metaplasia is the most critical. Except for intestinal metaplasia (IM), which is characterized by goblet cells appearing in the stomach glands, one type of mucous cell metaplasia, spasmolytic polypeptide-expressing metaplasia (SPEM), has attracted much attention. Epidemiological and clinicopathological studies suggest that SPEM may be more strongly linked to gastric adenocarcinoma than IM. SPEM, characterized by abnormal expression of trefoil factor 2, mucin 6, and Griffonia simplicifolia lectin II in the deep glands of the stomach, is caused by acute injury or inflammation. Although it is generally believed that the loss of parietal cells alone is a sufficient and direct cause of SPEM, further in-depth studies have revealed the critical role of immunosignals. There is controversy regarding whether SPEM cells originate from the transdifferentiation of mature chief cells or professional progenitors. SPEM plays a functional role in the repair of gastric epithelial injury. However, chronic inflammation and immune responses caused by H. pylori infection can induce further progression of SPEM to IM, dysplasia, and adenocarcinoma. SPEM cells upregulate the expression of whey acidic protein 4-disulfide core domain protein 2 and CD44 variant 9, which recruit M2 macrophages to the wound. Studies have revealed that interleukin-33, the most significantly upregulated cytokine in macrophages, promotes SPEM toward more advanced metaplasia. Overall, more effort is needed to reveal the specific mechanism of SPEM malignant progression driven by H. pylori infection.

Discovery of 1,2,4-triazine dithiocarbamate derivatives as NEDDylation agonists to inhibit gastric cancers

NEDDylation process regulates multiple physiological functions and signaling pathways, which are still in an equilibrium that favors the survival and proliferation of tumor cells. Unlike inhibitors, NEDDylation agonists are rarely studied. In this work, novel 1,2,4-triazine-dithiocarbamate derivatives were synthesized and evaluated for antiproliferative activity against MGC-803, PC-3 and EC-109 cells. Among them, compound K3 displayed the most potent activity MGC-803, PC-3 and EC-109 cells with IC₅₀ values of 2.35, 5.71 and 10.1 μM, respectively, which were more potent than 5-FU. Further cellular mechanisms suggested that compound K3 inhibited the cell viability, induced proliferation inhibition, arrested cell cycle at G2/M phase and induced cell apoptosis in MGC-803 and HGC-27 cells. Importantly, compound K3 could interact with NAE1 to promote the NEDDylation of MGC-803 and HGC-27 cells. The promotion of NEDDylation resulted in the degradation of c-IAP and YAP/TAZ, which leads to the induction of cell apoptosis and inhibition of proliferation in MGC-803 and HGC-27 cells. Therefore, as a NEDDylation agonist, compound K3 could effectively inhibit gastric cancer cells. Here, we reported NEDDylation promotion induced by compound K3, which could inhibit the cancer cell lines MGC-803 and HGC-27 and induce the cancer cell apoptosis via prompting the degradation of c-IAP and YAP/TAZ.

Laparoscopic vs Open Gastrectomy: an Updated Meta-analysis of Randomized Control Trials for Short-Term Outcomes

The aim of this meta-analysis was to compare short-term outcomes of laparoscopic and open gastrectomy for gastric cancer. EMBASE, MEDLINE, PubMed, and the Cochrane Database were searched for randomized control trials comparing outcomes in patients undergoing laparoscopic gastrectomies with those patients undergoing open gastrectomies. The primary outcome was 30-day morbidity and mortality. Secondary outcomes studied included length of stay, blood loss, d2 gastrectomies, lymph node retrieval, operative time, wound complications, and intraabdominal complications. Systemic review and meta-analysis were done according to MOOSE and PRISMA guidelines. Eleven RCTs consisting of 4614 patients were included in the study. A total of 2452 patients were there in laparoscopic gastrectomy group while 2162 patients were included in open gastrectomy group. Morbidity was significantly low in laparoscopic group (p = 0.003). There was no significant difference in mortality between the two groups (P = 0.75). There were fewer wound complications in laparoscopic group and no difference intra-abdominal complications in both groups. Blood loss was significantly lesser in laparoscopic group (p < 0.001). Hospital stay was similar in both groups (p = 0.30). Operative time was significantly higher in laparoscopic group (p < 0.001). Laparoscopic group patients had a lesser number of lymph node retrieval compared to open group (p = 0.002). Laparoscopic group also contained similar advanced staged gastric cancer than open gastrectomies (p = 0.64). Laparoscopic gastrectomies were associated with lesser wound-related complications without decreasing hospital stay with a smaller number of lymph nodes retrieval.

Mapping of the perigastric lymphatic network using indocyanine green fluorescence imaging and tissue marking dye in clinically advanced gastric cancer

BACKGROUND

Using indocyanine green (ICG) fluorescence imaging and tissue marking dyes (TMDs), perigastric lymphatic mapping and their pathological correlation were examined to see whether ICG staining covers all metastatic lymph nodes (LNs) in advanced gastric cancer (AGC).

METHODS

Patients with AGC who underwent open distal or total gastrectomy were enrolled. ICG was serially injected intraoperatively into the subserosa along the greater and lesser curvatures. Stomach specimens were examined under a near-infrared camera. ICG-stained LNs were named, excised, and tattooed with different colored TMDs to retrace the exact location after pathological examinations.

RESULTS

A total of 687 LNs and 69 LN stations were examined from 11 patients. The map of the perigastric lymphatic network showing the topography of ICG-stained and ICG-unstained LNs, including metastatic information, was successfully reconstructed. The average number of ICG-stained and ICG-unstained LNs were 23.6 ± 12.3 (37.8%) and 38.8 ± 17.1 (62.2%), respectively. LN metastases were present in 28 LN stations of 8 patients. Of 8 cases with LN metastases, 40% (11.1-75% per case) of metastatic LNs were stained by ICG. Of 28 metastatic LN stations, 21 (75.0%) were covered by ICG, and actual metastatic LNs were stained in 16 LN stations (57.1%). In 4/8 cases (50%), all metastatic LN stations showed ICG signals.

CONCLUSIONS

ICG fluorescence imaging and TMD are useful tools for visualizing the perigastric lymphatic network and retracing the exact location of ICG-stained LNs in AGC. However, ICG imaging is still not recommended for selective LN dissection in AGC because of the limited staining of perigastric LNs.

Isolation of lymphocytes from the human gastric mucosa

Flow cytometry is widely used for lymphocyte immunophenotyping in clinical settings. However, few studies have applied it for analyzing lymphocytes of the gastric mucosa. This review offers an overview of methodologies for isolating lymphocytes from the human stomach. Previously reported articles were reviewed, focusing on procedures for isolating human gastric mucosal lymphocytes. Helicobacter pylori-associated peptic diseases and gastric cancer are two major subjects of research in this field. Enzymatic dissociation, mechanical dissociation, or a combination of the two have been used to isolate lymphocytes from the stomach. Intra-epithelial and lamina propria lymphocytes were separately isolated in several studies. We also summarize the history and present trends in analyzing lymphocytes in patients with gastric disease.

Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in the management of peritoneal surface malignancies - An evidence-based review

BACKGROUND

Traditionally, peritoneal surface malignancies (PSM) were considered terminal diseases because of their advanced nature, therefore, systemic chemotherapy was given with palliative intent only. As a result, very poor survival outcomes were observed. But with the introduction of complete Cytoreductive surgery (CRS) and Hyperthermic intraperitoneal chemotherapy (HIPEC), the scenario has changed dramatically.

METHODOLOGY

An objective electronic database search was performed in Pubmed, NLM Catalog, Google scholar, Bookshelf, and Pubmed Central published in the time period from 2000 till 2020. All the randomized studies were included. In the absence of randomized studies, both prospective and retrospective studies were included. The outcomes of HIPEC were measured in terms of median survival, disease-free survival, overall survival, complications and drug toxicities.

RESULTS

CRS and HIPEC are considered the standard of care for PMP and MPM even in the absence of level 1 evidence due to lack of an effective alternative treatment. In colorectal and gastric cancer, several phase-three trials are showing overall survival benefit in selected cases while there is a prophylactic and palliative role of HIPEC in gastric cancer. Three reported phase 3 trials showed positive results in ovarian cancer. In peritoneal sarcomatosis, the role of HIPEC is yet to be proven.

CONCLUSION

The patient selection is the key to the successful outcomes after HIPEC. HIPEC should be performed by the experienced surgeons in specialized centres with a strong critical care and intensive care support to reduce the morbidity and mortality. Ongoing trials and future directions will prove to be an indispensable arm in the oncological armamentarium.

Diagnostic and prognostic value of plasma heat shock protein 90alpha in gastric cancer

BACKGROUND

The role of plasma heat shock protein 90alpha (Hsp90α) in gastric cancers remains unclear. This study aimed to clarify the diagnostic and prognostic value of plasma Hsp90α in gastric cancer.

METHODS

Data regarding 976 gastric cancer, 50 gastric inflammatory diseases, and 100 healthy controls were collected. Plasma Hsp90α levels in gastric cancer were compared to those in controls. Its correlation with tumor biomarkers and immune cells was examined. The association of plasma Hsp90α with clinical features and the diagnostic and prognostic value in gastric cancer were also determined.

RESULTS

Plasma Hsp90α levels were remarkably increased in gastric cancer, compared to those in gastric inflammatory diseases and healthy controls. Moreover, plasma Hsp90α was correlated with CEA, CA125, CA153, CA199, T cells, Th/Ts ratio, and B cells. Plasma Hsp90α was also associated with the metastasis stage. Multivariate logistic regression analysis revealed that Hsp90α, B cells, and T cells were significantly associated with gastric cancer. Plasma Hsp90α has a moderate diagnostic value, which increased when combined with B cell, T cells. Finally, plasma Hsp90α was not associated with the survival of gastric cancer patients.

CONCLUSION

Plasma Hsp90α was elevated in gastric cancer and correlated with tumor biomarkers and immune cells. Plasma Hsp90α was associated with the metastasis stage and had moderate diagnostic performance but little prognostic value in gastric cancer.

IRF-2 Inhibits Gastric Cancer Invasion and Migration by Down-Regulating MMP-1

PURPOSE

The interferon regulatory factor 2 (IRF-2) acted as a tumor suppressor. We inspected IRF-2 as a predictor of prognosis in gastric cancer (GC) patients and tried to find out the potential molecular mechanism.

METHODS

In this study, the association between IRF-2 expression and clinical or prognosis significance was investigated in 86 pairs of tumor and the adjacent normal gastric tissues from GC patients. After establishing the stable cell lines, the Transwell assays were deduced to evaluate the malignancy of tumor. Then, microarray assay was carried out and the GO/KEGG pathway analyses were conducted to identify IRF-2's target gene. The relationship between IRF-2 and matrix metalloproteinases 1 (MMP-1) was also investigated by the immunohistochemistry in 15 pairs of tumor and adjacent normal gastric tissues.

RESULTS

We found that IRF-2 expression level in GC was significantly correlated with the prognosis of the patients. Transwell assays suggested an impaired ability of invasion and migration in IRF-2-overexpressed GC cells and a progressive malignant phenotype in IRF-2-knockdown GC cells. Ninety differentially expressed genes were found between IRF-2-overexpressed GC cells and its normal control sets by microarray. We demonstrated that MMP-1 was canonical in the network of differentially expressed genes by GO and KEGG pathway analysis and its expression level was markedly decreased in IRF-2-overexpressed cells of MKN-45 and increased in IRF-2-knockdown cells of SGC-7901. The expression of MMP-1 was inversely correlated with IRF-2 in GAC TMA specimens.

CONCLUSION

IRF-2 may inhibit GC progression by down-regulating MMP-1 level.

Divergent Routes toward Wnt and R-spondin Niche Independency during Human Gastric Carcinogenesis

Recent sequencing analyses have shed light on heterogeneous patterns of genomic aberrations in human gastric cancers (GCs). To explore how individual genetic events translate into cancer phenotypes, we established a biological library consisting of genetically engineered gastric organoids carrying various GC mutations and 37 patient-derived organoid lines, including rare genomically stable GCs. Phenotype analyses of GC organoids revealed divergent genetic and epigenetic routes to gain Wnt and R-spondin niche independency. An unbiased phenotype-based genetic screening identified a significant association between CDH1/TP53 compound mutations and the R-spondin independency that was functionally validated by CRISPR-based knockout. Xenografting of GC organoids further established the feasibility of Wnt-targeting therapy for Wnt-dependent GCs. Our results collectively demonstrate that multifaceted genetic abnormalities render human GCs independent of the stem cell niche and highlight the validity of the genotype-phenotype screening strategy in gaining deeper understanding of human cancers.

Mutation heterogeneity between primary gastric cancers and their matched lymph node metastases

BACKGROUND

The acquisition of an invasive phenotype by a tumor cell is a crucial step of malignant transformation. The underlying genetic mechanisms in gastric cancer (GC) are not well understood.

METHODS

We performed whole-exome sequencing of 15 pairs of primary GC and their matched lymph node (LN) metastases (10 primary GCs with single matched LNs and 5 primary GCs with three LNs per case, respectively). Somatic alterations including single nucleotide variations, short insertions/deletions including locus-level microsatellite instability and copy number alterations were identified and compared between the primary and metastatic LN genomes.

RESULTS

Mutation abundance was comparable between the primary GC and LN metastases, but the extent of mutation overlap or the mutation heterogeneity between primary and LN genomes varied substantially. Primary- or LN-specific mutations could be distinguished from common mutations in terms of mutation spectra and functional categories, suggesting that the mutation forces are not constant during gastric carcinogenesis. A spatial distribution revealed TP53 mutations as common mutations along with a number of region-specific mutations, such as primary-specific SMARCA4 and LN-specific CTNNB1 mutations. The subclonal architectures of common mutations were largely conserved between primary GC and LN metastatic genomes. The mutation-based phylogenetic analyses further showed that LN metastases may have arisen from homogeneous subclones of primary tumors.

CONCLUSIONS

The abundance and spatial distribution of mutations may provide clues on the evolutionary relationship between primary and matched LN genomes. Gene-level analyses further distinguished the early addicted cancer drivers such as TP53 mutations from late acquired region-specific mutations.

Impact of in vitro driven expression signatures of CD133 stem cell marker and tumor stroma on clinical outcomes in gastric cancers

Background

The CD133 transmembrane protein is a well-recognized stem cell marker that has been used to isolate putative cancer stem cell populations from gastric cancers (GCs). However, the molecular features or biomarkers underlying CD133 are largely unknown in GCs.

Methods

We performed gene expression profiling of CD133+ and CD133- cells sorted by flow cytometry from three GC cell lines to identify the CD133 expression signatures of GC. The CD133 expression signatures were investigated across publicly available expression profiles of multiple tumor types including GC and also for their relationship with patient survival.

Results

The CD133 signature genes defined as 177 upregulated genes and 129 downregulated genes in CD133+ cells compared to CD133- cells were enriched with genes involving the cell cycle and cytoskeleton, implying that cancer stem cells with unlimited self-renewal play cancer-initiating roles. The CD133 expression signatures in GC expression profiles were positively correlated with those of brain tumors expressing CD133 and human embryonic stem cells, emphasizing the transcriptional similarities across stem cell-related expression signatures. We also found that these stem cell expression signatures were inversely correlated with those representing tumor infiltrating immune and stromal cells. Additionally, high CD133 expression signatures were found in intestinal subtypes and low tumor stage GCs as well as in those with microsatellite instabilities and high mutation burdens. As examined across 20 additional tumor types, both the expression signatures representing CD133 and stromal cells were unfavorable prognostic features; however, their impact were variable across tumor types.

Conclusions

The transcriptional activities of CD133 and those of stromal cells representing the activity of stem cells and level of epithelial-to-mesenchymal transition, respectively, may be inversely correlated with each other across multiple tumor types including GC. This relationship may be a confounding factor and should therefore be considered when evaluating the clinical relevance of stem cell-related markers.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5332-y) contains supplementary material, which is available to authorized users.

Preoperative Neutrophil to Lymphocyte Ratio and Lymphocyte to Monocyte Ratio are Prognostic Factors in Gastric Cancers Undergoing Surgery

BACKGROUND

Cancer outcome is considered to result from the interplay of several factors, among which host inflammatory and immune status are deemed to play a significant role. The neutrophil-to-lymphocyte ratio (NLR) and the lymphocyte-to-monocyte ratio (LMR) have been profitably used as surrogate markers of host immunoinflammatory status and have also been shown to correlate with outcome in several human tumors. However, only a few studies on these biomarkers have been performed in gastric cancer patients, yielding conflicting results.

METHODS

Data were retrieved from a prospective institutional database. Overall survival (OS) of 401 patients undergoing surgery for gastric cancer between January 2000 and June 2015 as well as disease-free survival (DFS) rates in 297 radically resected patients were calculated. MaxStat analysis was used to select cutoff values for NLR and LMR.

RESULTS

NLR and LMR did not significantly correlate with tumor stage. Patients with a high NLR and a low LMR experienced more tumor recurrences (p < 0.001) and had a higher hazard ratio (HR) for both OS (HR = 2.4 and HR = 2.10; p < 0.001) and DFS (HR = 2.99 and HR = 2.46; p < 0.001) than low NLR and high LMR subjects. Both biomarkers were shown to independently predict OS (HR = 1.65, p = 0.016; HR = 2.01, p = 0.002, respectively) and DFS (HR = 3.04, p = 0.019; HR = 4.76, p = 0.002, respectively). A score system combining both biomarkers was found to significantly correlate with long-term results.

CONCLUSIONS

A simple prognostic score including preoperative NLR and LMR can be used to easily predict outcome in gastric cancer patients undergoing surgery.

[Treatment Strategies after Non-curative Endoscopic Resection of Early Gastric Cancer]

The cases of non-curative endoscopic resection (NCR) of early gastric cancer have increased due to the widespread use of endoscopic submucosal dissection (ESD). NCR is associated with augmenting chances of local recurrence and lymph node metastasis (LNM). Therefore, some additional treatment strategies after NCR are needed. Treatment strategies for NCR should be determined by considering the risk of residual tumor or local recurrence and LNM. Additional surgical treatment such as gastrectomy and lymph node dissection are recommended in patients who have high-risk of LNM. Close observation without additional treatment is considered for selected patients with a less possibility of local recurrence or LNM. Also it may be suggested if there is no or less benefit from surgery in elderly patients or patients with underlying diseases. Additional endoscopic procedures including ESD, endoscopic mucosal resection or argon coagulation therapy are suggested alternatively for highly selected patients not at risk of LNM based on the absolute or expanded criteria of ESD.

A synthetic peptide hijacks the catalytic subunit of class I PI3K to suppress the growth of cancer cells

Activation of class I Phosphoinositide 3-kinases (PI3Ks) by mutation or overexpression closely correlates with the development of various human cancers. Class I PI3Ks are heterodimers composed of p110 catalytic subunits and regulatory subunits represented by p85. PAQR3 has been found to inhibit p110α activity by blocking its interaction with p85. In this study, we identified the N-terminal 6-55 amino acid residues of PAQR3 being sufficient for its interaction with p110α. A synthetic peptide, P6-55, that contains the N-terminus of PAQR3 could disrupt the interactions of p110α with both PAQR3 and p85. The activity of PI3K was also inhibited by P6-55, accompanied by significant inhibition of cancer cell proliferation. In a xenograft mouse model, P6-55 was able to reduce tumor growth in vivo. Furthermore, P6-55 was capable of inhibiting the elevated basal PI3K activity of H1047R, a hotspot mutation found in many types of human cancers. The cell proliferation and migration of cancer cells bearing H1047R mutation were also reduced by P6-55. In conclusion, our study provides a proof of concept that blocking the interaction of p110α with p85 by a peptide can serve as a new strategy to inhibit the oncogenic activity of PI3K in cancer therapy.

THE DISTRIBUTION, HISTOLOGIC PROFILE AND CLINICAL PRESENTATION OF GASTROINTESTINAL MALIGNANCIES IN LAGOS, NIGERIA

BACKGROUND

Gastrointestinal malignancies have continued to record higher incidence and therefore pose significant public health burden in terms of morbidity and mortality.

AIM

To evaluate the sociodemographic, histologic and clinical distribution of patients with gastrointestinal malignancies diagnosed between July 2009 and March 2016.

SETTING

Lagos University Teaching Hospital, Idi-Araba, south-west Nigeria.

METHODOLOGY

Using a retrospective study design, all the patients with histologic diagnosis of gastrointestinal malignancies were recruited and their bio-data, clinical, histologic and treatment data were extracted from their hospital records.

RESULTS

Of the 106 cases of gastrointestinal malignancies in this study, the age range was 30-82 years with a mean of 55.9±13 years and a peak age bracket of 50-59 years; the male/female ratio was 1.2:1. The most common sites were colorectum (79.3%), stomach (7.6%), anus (6.6%), liver (4.7%), and pancreas (0.9%). Adenocarcinoma was the most common histologic subtype (89.62%), followed by squamous cell carcinoma (2.83%) and gastrointestinal stromal tumors (1.89%). The most common complaints were abdominal pain (54.7%), constipation (38.7%), palpable abdominal swelling/masses (35.9%), bleeding (33.0%), and weight loss (17.0%). The tumors were treated with chemotherapy, surgery, and radiotherapy, either singly or in combination, in 97.2%, 83.0%, and 30.2% respectively.

CONCLUSION

In this study, colorectal cancers are still the most prevalent type of gastrointestinal malignancies with a male preponderance, and individuals between 40-59 years are at greater risk. The significant involvement of individuals who constitute the bulk of the workforce and are the most productive labor in the country points at the need to develop strategies aimed at reducing the incidence of gastrointestinal malignancies.

Potent effects of dioscin against gastric cancer in vitro and in vivo

BACKGROUND

We previously reported the effect of dioscin on human gastric carcinoma SGC-7901 cells, but its effects on other gastric cancers are still unknown.

PURPOSE

The present paper aimed to demonstrate the activity of dioscin against human gastric carcinoma MGC-803 and MKN-45.

STUDY DESIGN

In our study, MGC-803 and MKN-45 cells were used to examine the effects of dioscin on human gastric carcinoma in vitro. The effects of dioscin against human gastric carcinoma in vivo were accomplished by the xenografts of MGC-803 cells in BALB/c nude mice.

METHODS

AO/EB and DAPI staining, TEM, single cell gel electrophoresis and flow cytometry assays were used in cell experiments. Then, an iTRAQ-based proteomics approach, DNA and siRNA transfection experiments were carried out for mechanism investigation.

RESULTS

In MGC-803 cells, dioscin caused DNA damage and mitochondrial change, induced ROS generation, Ca(2+) release and cell apoptosis, and blocked cell cycle at S phase. In vivo results showed that dioscin significantly suppressed the tumor growth of MGC-803 cell xenografts in nude mice. In addition, dioscin markedly inhibited cell migration, caused Cytochrome c release and adjusted mitochondrial signal pathway. Then, an iTRAQ-based proteomics approach was carried out and 121 differentially expressed proteins were found, in which five biomarkers associated with cell cycle, apoptosis and migration were evaluated. Dioscin significantly up-regulated the levels of GALR-2 and RBM-3, and down-regulated CAP-1, Tribbles-2 and CliC-3. Furthermore, overexpressed DNA transfection of CAP-1 enhanced cell migration and invasion, which was decreased by dioscin. SiRNA to Tribbles-2 affected the protein levels of Bcl-2, Bax and MAPKs, suggesting that dioscin decreased Tribbles-2 level leading to cell apoptosis.

CONCLUSION

Our works confirmed the activity of dioscin against gastric cancer. In addition, this work also provided that dioscin is a new potent candidate for treating gastric cancer in the future.

Trends in Gastrointestinal Cancer Mortality Rate in Hungary

The aim of this study was to investigate the annual death trends for gastrointestinal cancer in Hungary between 1963 and 2012. Data on the numbers of cancer deaths were obtained from the published nationwide population register. Numbers of deaths from esophageal, gastric and colorectal cancer were available during the study period. However, the mortality data for hepatic, pancreatic and gallbladder cancer have been published only since 1979. Joinpoint regression was applied to investigate the annual trends in the rates of cancer mortality. The annual mortality rates of gastric and gallbladder cancer decreased throughout the study period. Furthermore, declines in mortality from esophageal and hepatic cancers have been observed since 1998 and 1995, respectively. However, the rates of colorectal and pancreatic cancer mortality have been increasing in the past few years. Nevertheless, the mortality rates of colorectal and pancreatic cancers have increased in males aged 40-59 years during the study period. Moreover, significantly higher risks of gastrointestinal cancer-related deaths have been observed in males as compared with females except for death related to cancer of the gallbladder. The presented data suggest that the Hungarian mortality rates are particularly high. The detection of gastrointestinal cancers at an early stage would significantly improves the outcome of these malignancies.

PET/Computed Tomography in the Diagnosis and Staging of Gastric Cancers

Although there has been a reduction of the incidence and mortality of gastric cancer, it remains among the commonest causes of cancer-related death. Accurate staging and evaluation of treatment response are vital for management. PET is used to complement anatomic imaging in cancer management. PET/computed tomography (CT) has demonstrated its potential value for preoperative staging, evaluation of response to therapy, and detection of recurrence. Not all types of gastric cancers have a high affinity for fluorodeoxyglucose. PET/CT in the evaluation and staging of gastric cancer is not established, but studies indicate that there may be an evolving role for this imaging modality.

Methylation of the Tumor Suppressor Gene RUNX3 in Human Gastric Carcinoma

BACKGROUND/AIMS

RUNX3 (PEBP2alphaC/CBFA3/AML2) is a novel tumor suppressor gene in the human gastric carcinoma. The aims of this study were to determine the methylation of RUNX3 promoter and the association between RUNX3 methylation and the clinicopathological characteristics of patients with gastric carcinoma.

METHODS

Seventy-nine patients with gastric carcinoma were studied prospectively from April 2005 to May 2007. The methylations of RUNX3 promoter on the gastric carcinoma specimens and the corresponding nonneoplastic mucosa were evaluated by methylation-specific polymerase chain reaction.

RESULTS

Comparison of the results with the clinicopathological characteristics identified RUNX3 monoallelic methylation in 32.9% (26/79) of the gastric carcinoma patients and in 11.4% (9/79) of those with nonneoplastic mucosa (p=0.053). The monoallelic methylated gastric carcinoma specimens predominantly consisted of well- and moderately differentiated carcinomas (44.7%), with the unmethylated group constituting 22.0% of them (p=0.031). Among the 48 patients (60.8%) who underwent gastrectomy, there was no correlation between the two groups with regard to Lauren's classification (p=0.235), depth of invasion (p=0.990), nodal status (p=0.601), stage (p=0.900), lymphatic invasion (p=0.537), and vascular invasion (p=0.815).

CONCLUSIONS

Methylation of the tumor suppressor gene RUNX3 might be one of the mechanisms involved in the pathogenesis of gastric carcinoma.