The prognostic significance of apoptosis-related biological markers in Chinese gastric cancer patients

Development of a Comprehensive Gene Signature Linking Hypoxia, Glycolysis, Lactylation, and Metabolomic Insights in Gastric Cancer through the Integration of Bulk and Single-Cell RNA-Seq Data

BACKGROUND

Hypoxia and anaerobic glycolysis are cancer hallmarks and sources of the metabolite lactate. Intriguingly, lactate-induced protein lactylation is considered a novel epigenetic mechanism that predisposes cells toward a malignant state. However, the significance of comprehensive hypoxia-glycolysis-lactylation-related genes (HGLRGs) in cancer is unclear. We aimed to construct a model centered around HGLRGs for predicting survival, metabolic features, drug responsiveness, and immune response in gastric cancer.

METHODS

The integration of bulk and single-cell RNA-Seq data was achieved using data obtained from the TCGA and GEO databases to analyze HGLRG expression patterns. A HGLRG risk-score model was developed based on univariate Cox regression and a LASSO-Cox regression model and subsequently validated. Additionally, the relationships between the identified HGLRG signature and multiple metabolites, drug sensitivity and various cell clusters were explored.

RESULTS

Thirteen genes were identified as constituting the HGLRG signature. Using this signature, we established predictive models, including HGLRG risk scores and nomogram and Cox regression models. The stratification of patients into high- and low-risk groups based on HGLRG risk scores showed a better prognosis in the latter. The high-risk group displayed increased sensitivity to cytotoxic drugs and targeted inhibitors. The expression of the HGLRG BGN displayed a strong correlation with amino acids and lipid metabolites. Notably, a significant difference in immune infiltration, such as that of M1 macrophages and CD8 T cells, was correlated with the HGLRG signature. The abundant DUSP1 within the mesenchymal components was highlighted by single-cell transcriptomics.

CONCLUSION

The innovative HGLRG signature demonstrates efficacy in predicting survival and providing a practical clinical model for gastric cancer. The HGLRG signature reflects the internal metabolism, drug responsiveness, and immune microenvironment components of gastric cancer and is expected to boost patients' response to targeted therapy and immunotherapy.

Targeting Bcl-2 for cancer therapy

Apoptosis deficiency is one of the most important features observed in neoplastic diseases. The Bcl-2 family is composed of a subset of proteins that act as decisive apoptosis regulators. Research and clinical studies have both demonstrated that the hyperactivation of Bcl-2-related anti-apoptotic effects correlates with cancer occurrence, progression and prognosis, also having a role in facilitating the radio- and chemoresistance of various malignancies. Therefore, targeting Bcl-2 inactivation has provided some compelling therapeutic advantages by enhancing apoptotic sensitivity or reversing drug resistance. Therefore, this pharmacological route turned into one of the most promising routes for cancer treatment. This review discusses some of the well-defined and emerging roles of Bcl-2 as well as its potential clinical value in cancer therapeutics.

Berbamine Suppresses the Progression of Bladder Cancer by Modulating the ROS/NF-κB Axis

Berbamine (BBM), one of the bioactive ingredients extracted from Berberis plants, has attracted intensive attention because of its significant antitumor activity against various malignancies. However, the exact role and potential molecular mechanism of berbamine in bladder cancer (BCa) remain unclear. In the present study, our results showed that berbamine inhibited cell viability, colony formation, and proliferation. Additionally, berbamine induced cell cycle arrest at S phase by a synergistic mechanism involving stimulation of P21 and P27 protein expression as well as downregulation of CyclinD, CyclinA2, and CDK2 protein expression. In addition to suppressing epithelial-mesenchymal transition (EMT), berbamine rearranged the cytoskeleton to inhibit cell metastasis. Mechanistically, the expression of P65, P-P65, and P-IκBα was decreased upon berbamine treatment, yet P65 overexpression abrogated the effects of berbamine on the proliferative and metastatic potential of BCa cells, which indicated that berbamine attenuated the malignant biological activities of BCa cells by inhibiting the NF-κB pathway. More importantly, berbamine increased the intracellular reactive oxygen species (ROS) level through the downregulation of antioxidative genes such as Nrf2, HO-1, SOD2, and GPX-1. Following ROS accumulation, the intrinsic apoptotic pathway was triggered by an increase in the ratio of Bax/Bcl-2. Furthermore, berbamine-mediated ROS accumulation negatively regulated the NF-κB pathway to a certain degree. Consistent with our in vitro results, berbamine successfully inhibited tumor growth and blocked the NF-κB pathway in our xenograft model. To summarize, our data demonstrated that berbamine exerts antitumor effects via the ROS/NF-κB signaling axis in bladder cancer, which provides a basis for further comprehensive study and presents a potential candidate for clinical treatment strategies against bladder cancer.

Downregulated genes by silencing MYC pathway identified with RNA-SEQ analysis as potential prognostic biomarkers in gastric adenocarcinoma

MYC overexpression is a common phenomenon in gastric carcinogenesis. In this study, we identified genes differentially expressed with a downregulated profile in gastric cancer (GC) cell lines with silenced MYC. The TTLL12, CDKN3, CDC16, PTPRA, MZT2B, UBE2T genes were validated using qRT-PCR, western blot and immunohistochemistry in tissues of 213 patients with diffuse and intestinal GC. We identified high levels of TTLL12, MZT2B, CDC16, UBE2T, associated with early and advanced stages, lymph nodes, distant metastases and risk factors such as H. pylori. Our results show that in the diffuse GC the overexpression of CDC16 and UBE2T indicate markers of poor prognosis higher than TTLL12. That is, patients with overexpression of these two genes live less than patients with overexpression of TTLL12. In the intestinal GC, patients who overexpressed CDC16 had a significantly lower survival rate than patients who overexpressed MZT2B and UBE2T, indicating in our data a worse prognostic value of CDC16 compared to the other two genes. PTPRA and CDKN3 proved to be important for assessing tumor progression in the early and advanced stages. In summary, in this study, we identified diagnostic and prognostic biomarkers of GC under the control of MYC, related to the cell cycle and the neoplastic process.

Beclin-1 expression is associated with prognosis in a Bcl-2-dependent manner in non-small cell lung cancer

Beclin-1 and Bcl-2 expression abnormalities have been confirmed in different types of cancer. As important regulators of autophagy and apoptosis, respectively, these molecules serve a complex role in tumorigenesis. However, limited information is currently available regarding the association between Beclin-1 and Bcl-2 in (NSCLC). In the present study, the expression levels of Beclin-1 and Bcl-2 were detected in lung cancer tissues, and their prognostic significance was analyzed for NSCLC. A total of 120 patients with lung cancer who underwent surgical resection were included in the present study. Beclin-1 and Bcl-2 expression was assessed using immunohistochemistry and their associations with the overall survival (OS) in patients with NSCLC was examined. The expression rate of Beclin-1 was significantly lower in NSCLC tissues compared with that in adjacent tissues, whereas the expression rate of Bcl-2 was significantly higher in lung cancer tissues compared with that in adjacent tissues. Additionally, Beclin-1 and Bcl-2 protein expression was strongly associated (P<0.05) in NSCLC. Patients with NSCLC with low Beclin-1 expression were in more advanced stages, with more lymph node metastasis and more poorly differentiated tumors. Similarly, patients with NSCLC with high Bcl-2 expression were also in a more advanced stage and had more lymph node metastasis. Cox regression analysis revealed that the association between Bcl-2 expression and survival was not significant, while a multivariate analysis revealed that Beclin-1 expression was significantly associated with OS. Notably, Beclin-1 expression was significantly associated with OS only in patients with high Bcl-2 expression. In conclusion, the present data indicated that the autophagy activity is decreased in NSCLC. Beclin-1 expression was downregulated, while Bcl-2 expression was upregulated in NSCLC tissues compared with that in adjacent tissues. Additionally, these two proteins were associated with the occurrence and progression of NSCLC. Beclin-1 may be a promising prognostic marker for patients with NSCLC with high Bcl-2 expression. The present findings provided a more accurate prognostic assessment for patients with NSCLC. Furthermore, they may be used to actively follow-up and promptly treat patients with a poor prognosis, which may benefit a greater number of patients with NSCLC.

Antitumor Effects of Trimethylellagic Acid Isolated From Sanguisorba officinalis L. on Colorectal Cancer via Angiogenesis Inhibition and Apoptosis Induction

Previous studies have demonstrated that tannin could inhibit the proliferation and angiogenesis of cancer cells. However, the mechanism(s) associated with its antitumor effect remains unclear. Here, we investigated the effects of 3,3',4'-trimethylellagic acid (TMEA), a tannin compound isolated from Sanguisorba officinalis L., on the proliferation, angiogenesis, and apoptosis in cancer cells, as well as the underlying mechanism(s) related to its antitumor activity. TMEA was isolated from Sanguisorba officinalis L. by silica gel column chromatography. Molecular docking was carried out to assess active pocket binding between TMEA and vascular endothelial growth factor receptor 2 (VEGFR2). The antiangiogenic effect of TMEA on the migration and tube formation was detected in HUVECs by wound healing and tube formation assays, respectively. The antitumor effects of TMEA on the cell proliferation were determined in HepG2, A549, and SW620 cells by MTS assay in vitro and on the tumor growth of SW620 xenografts bearing in nude mice in vivo. The mRNA expression of Bcl-2, Bax, caspase-3, VEGF, PI3K, and mTOR were measured by qRT-PCR and protein expression of Bcl-2, Bax, caspase-3, VEGF, PI3K, and mTOR by Western blotting, and the protein expression of Bcl-2, Bax, caspase-3 and CD31 were detected by immunohistochemical analysis in vivo, respectively. The results showed that TMEA combined with VEGFR2 in the functional pockets of Asn223A, Gly922A, and Leu840A and inhibited the proliferation, migration, tube formation, and expression of VEGF and its downstream signaling mediators in HUVECs. TMEA also significantly inhibited the proliferation of HepG2, A549, and SW620 cancer cells in vitro, and suppressed the growth of SW620 tumors in vivo. Moreover, TMEA upregulated the expression of proapoptotic factors Bax and caspase-3 and downregulated the expression of antiapoptotic factors CD31 and Bcl-2 in cancer cells and/or tumor tissues. The data indicate that TMEA executes its anticancer activity by inducing apoptosis and inhibiting angiogenesis in cancer cells in vitro and tumor growth in vivo. The underlying anticancer mechanism is associated with the apoptotic and VEGF/PI3K/AKT/mTOR pathways.

Gastric hepatoid adenocarcinomas are a genetically heterogenous group; most tumors show chromosomal instability, but MSI tumors do exist

The Cancer Genome Atlas Research Network classified gastric adenocarcinoma into four molecular subtypes: (1) Epstein-Barr virus-positive (EBV), (2) microsatellite-instable (MSI), (3) chromosomal instable (CIN), and (4) genomically stable (GS). The molecular subtypes of gastric hepatoid adenocarcinomas are still largely unknown. We analyzed 52 hepatoid adenocarcinomas for the expression of surrogate markers of molecular subtypes (MLH1, p53, and EBER in situ hybridization) and some biomarkers (p21, p16, Rb, cyclin D1, cyclin E, β-catenin, Bcl-2, IMP3, ARID1A and HER2), and mutations of TP53, CTNNB1, KRAS, and BRAF. We analyzed 36 solid-type poorly differentiated adenocarcinomas as a control group. Hepatoid adenocarcinomas were categorized as follows: EBV group (EBER-positive), no cases (0%); MSI group (MLH1 loss), three cases (6%); "CIN or GS" (CIN/GS) group (EBER-negative, MLH1 retained), 49 cases (94%). In the CIN/GS group, most of the tumors (59%) had either p53 overexpression or TP53 mutation and a coexisting tubular intestinal-type adenocarcinoma component (90%), suggesting that most hepatoid adenocarcinomas should be categorized as a true CIN group. Hepatoid adenocarcinomas showed relatively frequent expressions of HER2 (score 3+/2+: 21%/19%). Hepatoid adenocarcinomas showed shorter survival, more frequent overexpressions of p16 (67%) and IMP3 (98%) than the control group. None of hepatoid adenocarcinomas had KRAS or CTNNB1 mutations except for one case each, and no hepatoid adenocarcinomas had BRAF mutation. In conclusion, gastric hepatoid adenocarcinomas are a genetically heterogenous group. Most hepatoid adenocarcinomas are "CIN," but a small number of hepatoid adenocarcinomas with MSI do exist. Hepatoid adenocarcinomas are characterized by overexpressions of p16 and IMP3.

Gastric Cancer Cell Lines Have Different MYC-Regulated Expression Patterns but Share a Common Core of Altered Genes

MYC is an oncogene responsible for excessive cell growth in cancer, enabling transcriptional activation of genes involved in cell cycle regulation, metabolism, and apoptosis, and is usually overexpressed in gastric cancer (GC). By using siRNA and Next-Generation Sequencing (NGS), we identified MYC-regulated differentially expressed Genes (DEGs) in three Brazilian gastric cancer cell lines representing the histological subtypes of GC (diffuse, intestinal, and metastasis). The DEGs were picked using Sailfish software, followed by Gene Set Enrichment Analysis (GSEA) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway analysis using KEGG. We found 11 significantly enriched gene sets by using enrichment score (ES), False Discovery Rate (FDR), and nominal P-values. We identified a total of 5.471 DEGs with correlation over (80%). In diffuse-type and in metastatic GC cell lines, MYC-silencing caused DEGs downregulation, while the intestinal-type GC cells presented overall DEGs upregulation after MYC siRNA depletion. We were able to detect 11 significant gene sets when comparing our samples to the hallmark collection of gene expression, enriched mostly for the following hallmarks: proliferation, pathway, signaling, metabolic, and DNA damage response. When we analyzed our DEGs considering KEGG metabolic pathways, we found 12 common branches covering a wide range of biological functions, and three of them were common to all three cell lines: ubiquitin-mediated proteolysis, ribosomes, and system and epithelial cell signaling in Helicobacter pylori infection. The GC cell lines used in this study share 14 MYC-regulated genes, but their gene expression profile is different for each histological subtype of GC. Our results present a computational analysis of MYC-related signatures in GC, and we present evidence that GC cell lines representing distinct histological subtypes of this disease have different MYC-regulated expression profiles but share a common core of altered genes. This is an important step towards the understanding of MYC's role in gastric carcinogenesis and an indication of probable new drug targets in stomach cancer.

Effect of perioperative blood transfusion on prognosis of patients with gastric cancer: a retrospective analysis of a single center database

Background

The association between perioperative blood transfusion and the prognosis of patients with gastric cancer is still unclear.

Methods

A total of 1581 patients with gastric cancer who underwent curative gastrectomy from 2000 to 2008 were evaluated. Perioperative blood transfusion was defined as the transfusion of packed red blood cells within seven days before surgery, during surgery, or within the postoperative hospitalization period. The association between perioperative blood transfusion and prognosis was evaluated using univariate and multivariate Cox regression analyses.

Results

Of 1581 patients, 298 patients (19%) received perioperative blood transfusion. Perioperative blood transfusion correlated with older age (P < 0.001); larger tumor size (P < 0.001); and more advanced stage (P < 0.001). Five-year survival rate was 40% in patients who had perioperative blood transfusion and 55% patients who did not have perioperative blood transfusion, and the difference was statistically significant (P < 0.001). Multivariate analysis showed that perioperative blood transfusion was defined as independent prognostic factor. Perioperative blood transfusion was associated with worse outcomes in patients with stage III (P < 0.001).

Conclusions

Perioperative blood transfusion independently correlated with poorer prognosis in patients with gastric cancer.

Prognostic significance of cancer family history for patients with gastric cancer: a single center experience from China

Family history of cancer is a risk factor for gastric cancer. In this study, we investigated the prognoses of gastric cancer patients with family history of cancer. A total of 1805 gastric cancer patients who underwent curative gastrectomy from 2000 to 2008 were evaluated. The clinicopathologic parameters and prognoses of gastric cancer patients with a positive family history (PFH) of cancer were compared with those with a negative family history (NFH). Of 1805 patients, 382 (21.2%) patients had a positive family history of cancer. Positive family history of cancer correlated with younger age, more frequent alcohol and tobacco use, worse differentiation, smaller tumor size, and more frequent tumor location in the lower 1/3 of the stomach. The prognoses of patients with a positive family history of cancer were better than that of patients with a negative family history. Family history of cancer independently correlated with better prognosis after curative gastrectomy in gastric cancer patients.

Regulation of apoptosis is impaired in atrophic gastritis associated with gastric cancer

BACKGROUND

Gastric premalignant conditions, atrophic gastritis (AG) and intestinal metaplasia (IM) are characterized by an increase of proliferation and a reduction of apoptosis in epithelial cells. The epithelial cell kinetics in AG and IM in gastric mucosa adjacent to gastric cancer is still unclear. The aim of this study was to evaluate the epithelial cell turnover and expression of proliferation and apoptosis-related genes in gastric cancer (GC) and adjacent mucosa with atrophic gastritis or intestinal metaplasia (AG/IM GC+), as well as in atrophic gastritis or intestinal metaplasia mucosa of patients without GC (AG/IM GC-) and in control biopsy samples of non-transformed gastric mucosa (Control).

METHODS

We selected 58 patients (M: F = 34:24; age range 20-84 years, median 61.06 years) with 4 well defined histological conditions: 20 controls with histological finding of non-transformed gastric mucosa, 20 patients with AG or IM (AG/IM GC-), and 18 patients with intestinal type gastric adenocarcinoma (GC) and AG or IM in the adjacent mucosa (3 cm from the macroscopic tumour margin, AG/IM GC+). We performed an immunohistochemical staining of Ki67 and TUNEL and quantitative RT-PCR to determine the expression of PCNA and Bax/Bcl-2.

RESULTS

The immunohistochemical expression of Ki67 and TUNEL in AG/IM GC- was significantly increased compared to not transformed gastric mucosa (p < 0.0001) but not compared to AG/IM in gastric mucosa adjacent to GC. Levels of Bcl-2 were reduced in GC and AG/IM GC- compared to controls as well as in AG/IM GC- compared to AG/IM in mucosa adjacent to GC+ (p < 0.05). Proliferation and apoptosis markers did not correlate with H.pylori status in our study population.

CONCLUSIONS

In AG/IM associated with GC, no significant changes in the epithelial cell turnover were detected. Decreased Bcl-2 gene expression signified atrophic gastritis and IM in presence of cancer, as well as intestinal type gastric adenocarcinoma.

Follow-up after curative resection for gastric cancer: Is it time to tailor it?

There is still no consensus on the follow-up frequency and regimen after curative resection for gastric cancer. Moreover, controversy exists regarding the utility of follow-up in improving survival, and the recommendations of experts and societies vary considerably. The main reason to establish surveillance programs is to diagnose tumor recurrence or metachronous cancers early and to thereby provide prompt treatment and prolong survival. In the setting of gastric malignancies, other reasons have been put forth: (1) the detection of adverse effects of a previous surgery, such as malnutrition or digestive sequelae; (2) the collection of data; and (3) the identification of psychological and/or social problems and provision of appropriate support to the patients. No randomized controlled trials on the role of follow-up after curative resection of gastric carcinoma have been published. Herein, the primary retrospective series and systematic reviews on this subject are analyzed and discussed. Furthermore, the guidelines from international and national scientific societies are discussed. Follow-up is recommended by the majority of institutions; however, there is no real evidence that follow-up can improve long-term survival rates. Several studies have demonstrated that it is possible to stratify patients submitted to curative gastrectomy into different classes according to the risk of recurrence. Furthermore, promising studies have identified several molecular markers that are related to the risk of relapse and to prognosis. Based on these premises, a promising strategy will be to tailor follow-up in relation to the patient and tumor characteristics, molecular marker status, and individual risk of recurrence.

Prognostic Significance of Apoptosis-related Markers in Patients With Soft-Tissue Sarcomas of Extremities

Bcl-2 and Bax proteins are key regulators of apoptosis, a process that is deregulated in many human diseases, particularly cancer. Overexpression of antiapoptotic Bcl-2 protein is associated with drug resistance and poor clinical outcome in cancer patients, whereas the expression of proapoptotic Bax protein, commonly detected in soft-tissue sarcoma (STS), is often associated with chemiosensitivity in different tumors. Studies on the clinical implications of apoptosis-related markers Bcl-2 and Bax in STS are limited. In this study, immunohistochemistry for Bcl-2 and Bax was performed on tissue microarrays of 86 multiple types of adult STS of the extremities. Bcl-2 and Bax positive expression was detected in 25.9% and 66.7% of the sarcomas, respectively. Overexpression of both, Bcl-2 and Bax, was directly associated with histologic grade and clinical stage. A significant association between Bax and Bcl-2 expression was also observed (P=0.007). The 5-year overall survival for the group was 57%, and it was lower for cases that overexpressed Bcl-2 (47.6% vs. 58.3%) and Bax (50% vs. 66.7%), although not statistically significant. After multivariate analysis, only the high histologic grade appeared as an independent prognostic factor for the patients (P=0.043; HR=8.0; 95% CI, 1.1-60.1). In our study, Bcl-2 and Bax expression was significantly associated with histologic grade and clinical stage, which are classic factors of poor prognosis. We suggest the use of these proteins as potential prognostic markers in STS of extremities.

Relationship of Amplification and Expression of the C-MYC Gene with Survival among Gastric Cancer Patients

BACKGROUND

During the past decades, the incidence and mortality rate of stomach cancer has demonstrated a great decrease in the world, but it is still one of the most common and fatal cancers especially among men worldwide, including Iran. The MYC proto-oncogene, which is located at 8q24.1, regulates 15% of genes and is activated in 20% of all human tumors. MYC amplification and overexpression of its protein product has been reported in 15-30% of gastric neoplasias. The aim of this investigation was to find the relative efficacy of CISH (chromogenic in situ hybridization) or IHC (immunohistochemistry) in diagnosis and prognosis of gastric cancer, as well as the relationship of amplification and expression of C-MYC gene with patient survival.

MATERIALS AND METHODS

In this cross-sectional study, 102 samples of gastric cancer were collected from patients who had undergone primary surgical resection at the Cancer Institute Hospital, Tehran University of Medical Sciences, from July 2009 to March 2014. All samples were randomly selected from those who were diagnosed with gastric adenocarcinomas. CISH and IHC methods were performed on all of them.

RESULTS

Patients were classified into two groups. The first consisted of stage I and II cases, and the second of stage III and IV. Survival tests for both groups was carried out with referrnce to CISH test reults. Group II (stage III and IV) with CISH+ featured lower survival than those with CISH- (p=0.233), but group I (stage I and II) patients demonstrated no significant variation with CISH+ or CISH- (p=0.630). Kaplan-Meier for both groups was carried out with IHC test findings and showed similar results. This data revealed that both diffuse and intestinal types of gastric cancer occurred significantly more in men than women. Our data also showed that CISH+ patients (43%) were more frequent in comparison with IHC+ patients (14.7%).

CONCLUSIONS

For planning treatment of gastric cancer patients, by focusing on expanding tumors, which is the greatest concern of the surgeons and patients, CISH is a better and more feasible test than IHC, in regard to sensitivity and specificity. Therefore, CISH can be used as a feasible test for tumor growth and prognosis in stage III and IV lesions. This study also indicated that C-MYC amplification in gastric cancer is correlated with survival in advanced stages.

Maspin-related Orchestration of Aggressiveness of Gastric Cancer

BACKGROUND AND STUDY AIM

Although some hypotheses have been postulated on the genesis of gastric cancer (GC), the origin of this disease remains unclear. The aim of this study was to develop a hypothesis about gastric carcinogenesis based on our experience in the field of GC and on published reports on about 28 studies in the field of subcellular maspin expression in GC. In 180 cases of GC, the clinicopathologic features were correlated with the results obtained after paired immunohistochemical stains (tumor/normal mucosa) with 15 antibodies: E-cadherin, HER-2, VEGF, CD31, CD105, COX-2, maspin, bax, bcl-2, p53, Ki67, MLH-1, MSH-2, Mena protein, and vimentin.

RESULTS

Cytoplasmic maspin was observed in foveolar cells with intestinal metaplasia, whereas mixed (combined nuclear-cytoplasmic) expressions were more characteristic of the intramucosal foci of signet-ring cells and dysplastic cells. The tumor cells that expressed cytoplasmic maspin were mostly intestinal type bax/COX-2/Mena/E-cadherin-positive differentiated adenocarcinomas with nodular growth and more superficial invasion. The nuclear shift of maspin was more frequent in HER-2/p53-positive intestinal type adenocarcinomas with diffuse architecture at the invasion front, as well as for node-positive poorly cohesive carcinomas. Loss of maspin expression induced a higher risk of distant metastases, without differences in the survival rate.

CONCLUSIONS

In GC with associated metaplasia, cytoplasmic maspin is predominant; the nuclear shift induces local aggressiveness and risk of node metastases, whereas total loss can indicate a risk of distant metastases. In GC without associated metaplasia, nuclear expression of maspin is retained, indicating a more aggressive behavior.

Association Between Amplification and Expression of C-MYC Gene and Clinicopathological Characteristics of Stomach Cancer

Background:

The incidence rate of gastric cancer in western countries has shown a remarkable decline in the recent years while it is still the most common cancer among males in Iran. The proto-oncogene MYC, located at 8q24.1, regulates almost 15% of human genes and is activated in 20% of all tumors. The amplification of MYC and overexpression of its protein product are observed in 15 - 30% of gastric neoplasias.

Objectives:

The objective of this study was to find the preferences of Chromogenic In Situ Hybridization (CISH) and Immunohistochemistry (IHC) in diagnosis and prognosis of gastric cancer.

Patients and Methods:

We studied 102 samples of gastric cancer in Iran and all the patients had undergone primary surgical resection at the Cancer Institute Hospital, Tehran University of Medical Sciences. The CISH and IHC techniques were applied for all our samples. All of the samples had adenocarcinoma gastric cancer and were selected randomly. Also, the type of study was cross sectional. The sample size was 100 patients.

Results:

Our data revealed that both diffuse and intestinal types of gastric cancer occurred significantly more in males than females. Our results showed that there was an indication of some correlation between grades and CISH, although the difference was not significant. Our data also showed that CISH positive patients (43%) were more frequent compared to IHC positive patients (14.7%). There was a correlation between CISH and IHC. These results revealed that there was a significant difference between grades and IHC. There was also no statistical difference between CISH amplification in diffuse and intestinal types.

Conclusions:

From the results, it could be concluded that for administration of the treatment of stomach cancer, and progress and prognosis of tumor, which is important for patients and clinicians, the CISH is a better and more feasible test than IHC, in regards to sensitivity and specificity.

Clinicopathological Characteristics and Survival Outcomes of Primary Signet Ring Cell Carcinoma in the Stomach: Retrospective Analysis of Single Center Database

Purpose

To investigate the clinicopathological features and prognosis of signet ring cell carcinoma of the stomach (SRC).

Methods

A total of 1464 gastric cancer patients who underwent curative gastrectomy from 2000 to 2008 at a single center were evaluated. Signet ring cell carcinoma (SRC) was defined as the presence of at least 50% signet ring cells in the pathologic specimen. The clinicopathological parameters and prognosis of SRC were analyzed by comparing with non-signet ring cell carcinoma (NSRC).

Results

Of 1464 patients, 138 patients (9.4%) were classified as SRC. There were significant differences in gender, age, tumor location, TNM stage, p21 expression, and p53 expression between SRC and NSRC. The 5-year survival rates of SRC and NSRC were 36.2% and 49.5%, respectively. The prognosis of SRC was poorer than that of NSRC (P <0.001). Multivariate analysis showed that SRC histology was an independent factor for poor prognosis (P <0.001).

Conclusion

Patients with SRC tend to present with a more advanced stage and poorer prognosis than patients with other types of gastric carcinoma.

Detecting of gastric cancer by Bcl-2 and Ki67

Gastric cancer is one of the most common malignant tumors and the second leading cause of cancer-related deaths in China. Although there is some progress in diagnose and treatment, the incidence of gastric cancer still keeps up increasing. In this study 40 patients with gastric cancer who underwent surgical operation is detected by immunohistochemistry. The positive rates of Bcl-2 and Ki67 protein expression in gastric cancer tissues were significantly higher than normal gastric mucous tissues. Correlation analysis showed that the expression of Bcl-2 is not correlated with that of Ki67. Positive expression of Bcl-2 or Ki67 did not correlate with age, gender, differentiation, stage and lymph node metastasis. These suggested that combination of Bcl-2 and Ki67 to detect gastric cancer is more effective.

Study of C-MYC amplification and expression in Iranian gastric cancer samples using CISH and IHC methods

Background:

Gastric cancer is the fourth most frequent malignancy and the second cause of cancer-related mortality worldwide. It has been suggested that in gastric carcinogenesis, the C-MYC gene has an important function. The objective of this study is to establish the preference of Chromogenic in situ hybridization (CISH) and Immunohistochemistry (IHC) in the diagnosis and prognosis of gastric cancer.

Materials and Methods:

Samples comprised of 50 randomly selected patients of whom 40 were male and 10 female. To evaluate the MYC copy number and its protein expression, CISH and IHC analyses were performed for 50 gastric adenocarcinomas, in Iran.

Results:

The location of the tumor in 64% of the patients was the fundus, and in 72% of patients, the tumors were of a diffuse type; 22 samples showed no amplification, and 28 samples were with amplification. MYC immunoreactivity was observed in 13 samples. Twelve samples showed both MYC amplification and MYC immunoreactivity. In addition, among the 28 CISH+ samples, 12 samples had positive signals for IHC and 16 samples had negative signals for IHC. A majority of the IHC-negative patients had no amplification, but only one patient with IHC positive had no amplification.

Conclusion:

Our conclusion was that for the management and treatment of gastric cancer, and for special attention of clinicians, for prognosis and tumor progression, the CISH was a better and more feasible test than IHC, in regard to the sensitivity and specificity.

Biomarkers for gastric cancer: Progression in early diagnosis and prognosis (Review)

Gastric cancer is one of leading causes of cancer-related mortality worldwide and is a notable disease due to its heterogeneity. Recently, numerous studies have investigated the molecular basis of gastric cancer, involving the alteration of pathogenesis, and invasion and metastasis. With the development of modern technologies, various novel biomarkers had been identified that appear to possess diagnostic and prognostic value; therefore, the present review describes our current knowledge of biomarkers for the early diagnosis and prognosis of gastric cancer. Classic biomarkers for gastric cancer diagnosis include carcinoembryonic antigen and cancer antigen 19-9, while microRNA and DNA hypomethylation are proposed as novel biomarkers. Excluding classical biomarkers, biomarkers for determining the progression and prognosis of gastric cancer focus on targeting microRNAs, epigenetic alterations and genetic polymorphisms.

Bcl-2 expression and patient survival in gastric cancer: a systematic review of the literature with meta-analysis

The prognostic role of Bcl-2 in gastric cancer remains controversial. We systematically reviewed the evidence for the effect of Bcl-2 expression in gastric cancer to elucidate this issue. PubMed, EMBASE, and Web of Science were searched to identify eligible studies to evaluate the association between Bcl-2 expression and overall survival (OS) and clinicopathological features of gastric cancer. Hazard ratios (HRs) or odds ratios (ORs) with 95 % confidence interval (95 % CI) were pooled to estimate the effect. Bcl-2 expression was not significantly correlated with OS of gastric cancer patients (combined HR 0.88, 95 % CI 0.62-1.25). Subgroup analysis indicated that Bcl-2 expression had a favorable impact on OS in Asian countries (HR 0.60, 95 % CI 0.47-0.77) and cutoff value <15 % (HR 0.69, 95 % CI 0.48-0.97). Furthermore, Bcl-2 expression was significantly associated with TNM stage (OR 0.58, 95 % CI 0.41-0.80), the depth of invasion (OR 0.53, 95 % CI 0.37-0.76), and lymph node metastasis (OR 0.55, 95 % CI 0.42-0.71). Bcl-2 expression predicts less invasion and malignancy in clinicopathological features. Moreover, Bcl-2 could be a favorable prognostic marker for patients of Asian countries.

How prognostic and predictive biomarkers are transforming our understanding and management of advanced gastric cancer

BACKGROUND

Gastric cancer (GC) is the second leading cause of cancer death worldwide. GC is a heterogeneous disease in terms of histology, anatomy, and epidemiology. There is also wide variability in how GC is treated in both the resectable and unresectable settings. Identification of prognostic and predictive biomarkers is critical to help direct and tailor therapy for this deadly disease.

METHODS

A literature search was done using Medline and MeSH terms for GC and predictive biomarkers and prognostic biomarkers. The search was limited to human subjects and the English language. There was no limit on dates. Published data and unpublished abstracts with clinical relevance were included.

RESULTS

Many potential prognostic and predictive biomarkers have been assessed for GC, some of which are becoming practice changing. This review is focused on clinically relevant biomarkers, including EGFR, HER2, various markers of angiogenesis, proto-oncogene MET, and the mammalian target of rapamycin.

CONCLUSION

GC is a deadly and heterogeneous disease for which biomarkers are beginning to change our understanding of prognosis and management. The recognition of predictive biomarkers, such as HER2 and vascular endothelial growth factor, has been an exciting development in the management of GC, validating the use of targeted drugs trastuzumab and ramucirumab. MET is another potential predictive marker that may be targeted in GC with drugs such as rilotumumab, foretinib, and crizotinib. Further identification and validation of prognostic and predictive biomarkers has the potential transform how this deadly disease is managed.

Ataxin-3 expression correlates with the clinicopathologic features of gastric cancer

To investigate the expression of Ataxin-3 in human gastric cancer tissues and cell lines, and explore its clinical pathologic significance.

METHODS

The expression of Ataxin-3 in gastric cancer (n=536) and noncancerous gastric mucosa (n=312) was determined by immunohistochemistry and correlated to clinicopathologic features such as histologic differentiation and tumor size. The expression of Ataxin-3 protein in the human gastric cancer cell lines MKN45, SGC7901 and in normal human gastric epithelial cells (GES-1) was also evaluated by Western blot analysis. Quantitative real-time PCR was used to determine Ataxin-3 mRNA expression in human gastric cancer cell lines and tissues.

RESULTS

The expression of Ataxin-3 protein was decreased in the gastric cancer compared to noncancerous gastric tissue, and correlated with tumor size, Lauren classification, histologic differentiation, and mutant p53 protein (P < 0.05). Similarly, Ataxin-3 mRNA expression was decreased in the gastric cancers compared to the noncancerous gastric tissue. Ataxin-3 protein and mRNA expression was lower in MKN45, SGC7901 cells than in the normal GES-1 cells.

CONCLUSION

Decreased expression of Ataxin-3 may play an important role in gastric carcinogenesis and development of gastric cancer.

The expression and clinical significance of miR-132 in gastric cancer patients

Background and objective

miR-132 plays a role in regulating neuronal morphology and cellular excitability. Little is known about the effects of miR-132 in cancer. The aim of this study is to evaluate the expression of miR-132 and its clinical significance in gastric cancer.

Methods

Cancerous tissues and corresponding normal tissues from 79 patients with gastric cancer were examined for the expression of miR-132 using quantitative PCR and the association between miR-132 expression levels and clinicopathological factors and prognosis was analyzed.

Results

In 79 clinical samples of gastric cancer patients, miR-132 expression levels in cancer tissues were significantly higher than those in the corresponding normal tissues (P = 0.001). Higher expression levels of miR-132 were associated with more frequent lymph node metastasis (P = 0.033), more lymphatic tumor emboli (P = 0.007), and more advanced stage (P = 0.016). Additionally, expression of miR-132 was an independent prognostic factor for overall survival (P = 0.020).

Conclusion

miR-132 could serve as an efficient prognostic factor for gastric cancer patients.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8168577241196050

Expression of CD24, p21, p53, and c-myc in alpha-fetoprotein-producing gastric cancer: Correlation with clinicopathologic characteristics and survival

BACKGROUND AND OBJECTIVE

The aim of this study was to evaluate the expression of CD24, p21, p53, and c-myc in lesions of patients with Alpha-Fetoprotein (AFP)-producing gastric cancer and their correlation with clinicopathological features and prognosis.

METHODS

One hundred and four patients with AFP-producing gastric cancer were included into this study. The levels of CD24, p21, p53, and c-myc were examined by immunohistochemistry.The prognostic value of these biological markers and the correlation between biological markers and clinicopathological factors were investigated.

RESULTS

The percentages of positive expression of CD24, p21, p53, and c-myc were 31.7%, 77.9%, 75.0%, and 66.3%, respectively. CD24 expression correlated with histological grade (P = 0.045) and Lauren type (P = 0.006); p21expression with Borrmann type (P = 0.035); c-myc expression with Borrmann type (P = 0.029). p21 expression was related with poor survival in univariate analysis (P = 0.016). Multivariate analysis showed that p21 expression, vascular invasion, and pathological stage were defined as independent prognostic factors.

CONCLUSION

The expression of p21 was an independent prognostic factor for patients with AFP-producing gastric cancer.

Prediction of tumor recurrence after curative resection in gastric carcinoma based on bcl-2 expression

Background

There are currently no reliable predictive factors for gastric cancer recurrence. The aim of this study was to evaluate the relationship between bcl-2 expression and risk of gastric cancer recurrence.

Methods

From January 1996 to December 2007, 449 gastric cancer patients who underwent curative resection were retrospectively studied. The expression levels of bcl-2 were examined by immunohistochemistry. Logistic regression was performed to identify independent risk factors for overall recurrence of gastric cancer.

Results

151 patients (33.6%) experienced recurrences. The median time to recurrence was 17.0 months, 113 (74.8%) patients had recurrences within 2 years. Peritoneal recurrence was the most prevalent pattern, followed by hematogenous metastasis in which the liver was the most common site. Depth of invasion, lymph node metastases, and negative expression of bcl-2 were independent risk factors for overall recurrence. The overall survival time of recurrent patients was 22.7 months. The median survival time after recurrence was 6.7 months.

Conclusion

The depth of invasion, lymph node metastases and expression of bcl-2 are independent factors for predicting gastric cancer recurrence.

The expression of Bcl-2 and BID in gastric cancer cells

Background. Bcl-2 and BID play a major role in the process of apoptosis and their dysfunction underlies carcinogenesis. The study objective was to assess the expression of Bcl-2 and BID in gastric cancer cells in correlation with chosen clinicopathological parameters, presence of Helicobacter pylori infection, and patients' survival. Materials and Methods. The study involved 88 patients operated on for gastric cancer. The expressions of Bcl-2 and BID were determined immunohistochemically. Results. Positive Bcl-2 expression was found in 55.7% and, BID in 53.6% of patients. The Bcl-2 expression correlated with stage pT3 and T4 gastric cancer (P < 0.05), with the intestinal type according to Lauren (P < 0.001), ulcerated type according to Bormann's classification (P < 0.01), and with local lymph node metastases (P < 0.05). Conclusion. The Bcl-2 protein plays a key role in the process of gastric cancer formation and is associated with the growth of definite types of gastric cancer.

XB130 promotes proliferation and invasion of gastric cancer cells

Background

XB130 has been reported to be expressed by various types of cells such as thyroid cancer and esophageal cancer cells, and it promotes the proliferation and invasion of thyroid cancer cells. Our previous study demonstrated that XB130 is also expressed in gastric cancer (GC), and that its expression is associated with the prognosis, but the role of XB130 in GC has not been well characterized.

Methods

In this study, we investigated the influence of XB130 on gastric tumorigenesis and metastasis in vivo and in vitro using the MTT assay, clonogenic assay, BrdU incorporation assay, 3D culture, immunohistochemistry and immunofluorescence. Western blot analysis was also performed to identify the potential mechanisms involved.

Results

The proliferation, migration, and invasion of SGC7901 and MNK45 gastric adenocarcinoma cell lines were all significantly inhibited by knockdown of XB130 using small hairpin RNA. In a xenograft model, tumor growth was markedly inhibited after shXB130-transfected GC cells were implanted into nude mice. After XB130 knockdown, GC cells showed a more epithelial-like phenotype, suggesting an inhibition of the epithelial-mesenchymal transition (EMT) process. In addition, silencing of XB130 reduced the expression of p-Akt/Akt, upregulated expression of epithelial markers including E-cadherin, α-catenin and β-catenin, and downregulated mesenchymal markers including fibronectin and vimentin. Expression of oncoproteins related to tumor metastasis, such as MMP2, MMP9, and CD44, was also significantly reduced.

Conclusions

These findings indicate that XB130 enhances cell motility and invasiveness by modulating the EMT-like process, while silencing XB130 in GC suppresses tumorigenesis and metastasis, suggesting that it may be a potential therapeutic target.

Research and clinical applications of molecular biomarkers in gastrointestinal carcinoma (Review)

Gastrointestinal (GI) carcinoma is a common malignant disease worldwide. Its development and progression is a multistage process involving a multifactorial etiology. Although the detailed mechanisms of the development of GI carcinoma remain controversial, the elucidation of its molecular biology over the last few years has resulted in a better perspective on its epidemiology, carcinogenesis and pathogenesis. More significantly, it is currently possible to use biological indicators or biomarkers in differential diagnosis, prognostic evaluation and specific clinical interventions. In this review, we aimed to describe the biomarkers of pathogenesis, invasion, metastasis and prognosis of GI carcinoma and discuss their potential clinical applications. The majority of these biomarkers, such as tumor-associated antigens, oncogenes and tumor suppressor genes, metastasis-associated genes, cell adhesion molecules, cytokines, growth factors and microRNAs, are currently broadly applicable.

Metallothionein 2A inhibits NF-κB pathway activation and predicts clinical outcome segregated with TNM stage in gastric cancer patients following radical resection

Background

Metallothionein 2A (MT2A) as a stress protein, plays a protective role in gastric mucosal barrier. Its role in the development of gastric cancer (GC) is unclear. The mechanism of MT2A will be investigated in gastric tumorigenesis.

Methods

MT2A expression was detected in 973 gastric specimens. The biological function was determined through ectopic expressing MT2A in vitro and in vivo. The possible downstream effectors of MT2A were investigated in NF-κB signaling. The protein levels of MT2A, IκB-α and p-IκB-α (ser32/36) expression were analyzed in a subset of 258 patients by IHC staining. The prognostic effects of MT2A, status of IκB-α and TNM stage were evaluated using the Kaplan-Meier method and compared using the log-rank test.

Results

Decreased MT2A expression was detected in cell lines and primary tumors of GC. In clinical data, loss of MT2A (MT2A + in Normal (n =171, 76.0%); Intestinal metaplasia (n = 118, 50.8%); GC (n = 684. 22.4%, P < 0.001)) was associated with poor prognosis (P < 0.001), advanced TNM stage (P = 0.05), and down-regulation of IκB-α expression (P < 0.001). Furthermore, MT2A was the independent prognostic signature segregated from the status of IκB-α and pathological features. In addition, MT2A inhibited cell growth through apoptosis and G2/M arrest, which negatively regulated NF-κB pathway through up-regulation of IκB-α and down-regulation of p-IκB-α and cyclin D1 expression.

Conclusions

MT2A might play a tumor suppressive activity through inhibiting NF-κB signaling and may be a prognostic biomarker and potential target for individual therapy of GC patients.

Prognostic role of human epidermal growth factor receptor in gastric cancer: a systematic review and meta-analysis

BACKGROUND AND AIMS

Human epidermal growth factor receptor (EGFR) and HER2 (ErbB2) both belong to EGFR family, which are overexpressed in a significant proportion of cases of gastric cancer (GC). Various studies have evaluated the prognostic value of EGFR or HER level in GC. However, the overall test performance remains unclear. We undertook this study to perform a systematic review and meta-analysis of prognostic cohort studies evaluating the use of EGFR or HER2 as a predictor of survival time in patients with GC.

METHODS

Eligible studies were identified through multiple search strategies. Studies were assessed for quality using the Newcastle-Ottawa Tool. Data were collected comparing overall survival (OS) in patients with high and low EGFR or HER2 level. Studies were pooled and summary hazard ratios were calculated.

RESULTS

Studies were listed twice if they provided overall survival data for both EGFR and HER2. Eight studies (seven for EGFR and eight for HER2) were included. Two distinct groups were pooled for analysis and revealed that high EGFR, HER2 levels predicted poor overall (HR = 1.66, 95% CI: 1.35-2.02) and (HR = 1.43, 95% CI: 1.09-1.88) survival. No publication bias was found.

CONCLUSIONS

This meta-analysis result suggested that EGFR or HER2 should have significant predictive ability for estimating overall survival in GC patients and may be useful for defining prognosis of GC patients.

FOXO6 promotes gastric cancer cell tumorigenicity via upregulation of C-myc

The aberrant regulation of many related genes is involved in the development and progression of gastric carcinoma. In the present study, we show that mRNA and protein levels of FOXO6 are upregulated in gastric cancer tissues. Forced overexpression of FOXO6 promotes gastric cancer cell proliferation, while knockdown of FOXO6 expression inhibits proliferation. We show that ectopic FOXO6 expression induces the expression of C-myc. Furthermore, we found that FOXO6 physically interacts with the transcription factor hepatic nuclear factor 4 (HNF4) in gastric cancer cells. FOXO6 induces C-myc expression by associating to HNF4 and mediating histone acetylation, and the dissociation of HDAC3 from the promoter of the C-myc gene. Therefore, our results suggest a previously unknown FOXO6/HNF4/C-myc molecular network controlling gastric cancer development.

Role of BAX for outcome prediction in gastrointestinal malignancies

Our group and numerous others have shown in both preclinical and clinical studies that the proapoptotic mediator BAX may be deregulated through gene mutation or loss of protein expression, affecting resistance to chemotherapy and radiotherapy in several cancer types. However, BAX is also involved in cancer development and may related to prognosis, independently of treatment outcome. The clinical impact of BAX status in gastrointestinal malignancies remains controversial, although it is generally hypothesized that high expression may be a positive prognostic factor and predict increased efficacy of chemotherapy (with particular regard to platinum derivatives). The present review aims to provide updated information on BAX as potential prognostic and/or predictive biomarker in gastroesophageal and colorectal cancers, as well as in other less studied gastrointestinal malignancies.

MYC deregulation in gastric cancer and its clinicopathological implications

Our study investigated the relationship between MYC alterations and clinicopathological features in gastric cancers. We evaluated the effect of MYC mRNA expression and its protein immunoreactivity, as well as copy number variation, promoter DNA methylation, and point mutations, in 125 gastric adenocarcinoma and 67 paried non-neoplastic tissues. We observed that 77% of the tumors presented MYC immunoreactivity which was significantly associated with increased mRNA expression (p<0.05). These observations were associated with deeper tumor extension and the presence of metastasis (p<0.05). MYC protein expression was also more frequently observed in intestinal-type than in diffuse-type tumors (p<0.001). Additionally, MYC mRNA and protein expression were significantly associated with its copy number (p<0.05). The gain of MYC copies was associated with late-onset, intestinal-type, advanced tumor stage, and the presence of distant metastasis (p<0.05). A hypomethylated MYC promoter was detected in 86.4% of tumor samples. MYC hypomethylation was associated with diffuse-type, advanced tumor stage, deeper tumor extension, and the presence of lymph node metastasis (p<0.05). Moreover, eighteen tumor samples presented at least one known mutation. The presence of MYC mutations was associated with diffuse-type tumor (p<0.001). Our results showed that MYC deregulation was mainly associated with poor prognostic features and also reinforced the presence of different pathways involved in intestinal-type and diffuse-type gastric carcinogenesis. Thus, our findings suggest that MYC may be a useful marker for clinical stratification and prognosis.

Decreased expression of HOXB9 is related to poor overall survival in patients with gastric carcinoma

BACKGROUND

Studies have demonstrated the implication of HOXB9 in tumorigenesis, but its role in gastric carcinoma remains unknown.

AIMS

To investigate the expression and prognostic value of HOXB9 in patients with gastric carcinoma.

METHODS

The localization and expression of HOXB9 in gastric cancer cells lines were detected by immunofluorescence and western blot. The mRNA and protein expression level of HOXB9 was detected in subjects with gastric carcinoma and paired non-cancerous tissues. Correlation between HOXB9 expression and clinicopathological parameters, the association of HOXB9 expression with the patients' survival rate was also assessed.

RESULTS

HOXB9 was predominantly localized in the cell nucleus. A significant decrease in HOXB9 intensity in poorly differentiated gastric cancer cells is evident (P<0.01). A lower mRNA and protein expression level of HOXB9 was detected in gastric carcinoma (P<0.01). Decreased expression of HOXB9, poorly differentiation status and the presence of lymph node metastasis predict shorter overall survival (P<0.05). Patients without HOXB9 expression had a lower overall survival rate (P<0.01). Multivariate Cox regression analysis showed HOXB9 was an independent prognostic factor in gastric carcinoma (P<0.01).

CONCLUSIONS

HOXB9 is down-regulation in gastric carcinoma and may be a novel prognostic marker for poorer clinical outcome for patients with gastric carcinoma.

Risk assessment of mouse gastric tissue cancer induced by dichlorvos and dimethoate

Cancer hazards from pesticide residues in food have been much discussed in the past decade. In this study, we showed that dichlorvos and dimethoate affect hemoglobin content and hematocrit value, but had no effect on red blood cell counts and total plasma protein in mice. A 40-mg/kg/day dose of dichlorvos upregulated the expression of p16, Bcl-2 and c-myc genes in mouse gastric tissue. By contrast, expression of the p16, Bcl-2 and c-myc genes induced by low doses (5, 10 and 20 mg/kg/day) of dichlorvos demonstrated no change in the control check group (CK; 200 μl sterile saline perfused group; 0 mg/kg/day). Different doses of dimethoate all upregulated the expression of p16, Bcl-2 and c-myc genes in mouse gastric tissue. The results further demonstrated that mouse gastric tissue, exposed in the long-term to low doses of dichlorvos and dimethoate, has the potential to become cancerous.

Synergistic role between p53 and JWA: prognostic and predictive biomarkers in gastric cancer

Expression of p53 appears to be correlated to prognosis in patients with malignancy, but its role in gastric carcinoma has remained controversial. Recently we reported that JWA, an ADP-ribosylation-like factor 6 interacting protein 5 (ARL6ip5), was both prognostic for overall survival and predictive for platinum-based treatment of gastric cancer. In this study, we aimed to investigate p53 expression as a prognostic and predictive marker in resectable gastric cancer, alone and in combination with JWA. Expression of p53 was examined in three large patient cohorts (total n = 1155) of gastric cancer. High expression of p53 was significantly correlated with unfavorable clinicopathologic parameters and decreased overall patient survival. Furthermore, patients with high p53 expression in tumors acquired remarkable survival benefit from adjuvant first-line platinum-based-chemotherapy. The synergy between p53 and JWA in predicting patient outcome was demonstrated, while no significantly elevated predictive value concerning chemotherapy was observed. Thus, p53 expression is a potent prognostic and predictive factor for resectable gastric cancer with adjuvant platinum-based chemotherapy. A combined effect of p53 with JWA as efficient prognostic indicators was found for the first time.

miR-204 targets Bcl-2 expression and enhances responsiveness of gastric cancer

Micro RNAs (miRs) are small non-coding RNAs aberrantly expressed in human tumors. Here, we aim to identify miRs whose deregulated expression leads to the activation of oncogenic pathways in human gastric cancers (GCs). Thirty nine out of 123 tumoral and matched uninvolved peritumoral gastric specimens from three independent European subsets of patients were analyzed for the expression of 851 human miRs using Agilent Platform. The remaining 84 samples were used to validate miRs differentially expressed between tumoral and matched peritumoral specimens by qPCR. miR-204 falls into a group of eight miRs differentially expressed between tumoral and peritumoral samples. Downregulation of miR-204 has prognostic value and correlates with increased staining of Bcl-2 protein in tumoral specimens. Ectopic expression of miR-204 inhibited colony forming ability, migration and tumor engraftment of GC cells. miR-204 targeted Bcl-2 messenger RNA and increased responsiveness of GC cells to 5-fluorouracil and oxaliplatin treatment. Ectopic expression of Bcl-2 protein counteracted miR-204 pro-apoptotic activity in response to 5-fluorouracil. Altogether, these findings suggest that modulation of aberrant expression of miR-204, which in turn releases oncogenic Bcl-2 protein activity might hold promise for preventive and therapeutic strategies of GC.

Abnormal expression of GADD45B in human colorectal carcinoma

Background

GADD45B is a member of the growth arrest DNA damage-inducible gene family associated with cell growth control, apoptosis, and DNA damage repair response. The aim of this study is to detect the role of GADD45B in colorectal carcinoma (CRC); the area not studied in depth to date.

Methods

The mRNA and protein levels of GADD45B were examined by Real-Time quantitative PCR (RT-qPCR) and immunohistochemistry (IHC) in CRC tissues and adjacent noncancerous tissues (ANCT). Over-expression plasmids and SiRNA were used to regulate GADD45B expression in CRC cell lines in vitro and flow cytometry and Western blotting were used to detect apoptotic changes.

Results

The mRNA and protein levels of GADD45B were significantly higher in CRC tissues than those in ANCT (P<0.05). Up-regulation of GADD45B was also correlated with relapse and death of CRC patients (P<0.05). The Kaplan-Meier survival curves indicated that disease-free survival (DFS) was significantly worse in CRC patients who showed GADD45B overexpression. A Cox multivariate analysis revealed that GADD45B overexpression and TNM stage were significant factors affecting patients’ survival. On the other hand, as a tumor suppressor gene, GADD45B amplified from normal colorectal tissues could induce apoptosis in CRC cell lines and may be associated with the p53-mediated apoptotic pathways.

Conclusion

GADD45B, a tumor suppressor gene potentially through the p53-mediated apoptotic pathways, is paradoxically overexpressed in CRC and as such may play an unappreciated role in tumorigenesis. The exact mechanism of GADD45B inactivation and overexpression requires further investigation. GADD45B could be a potential therapeutic target for CRC treatment in future.

Alterations of the TP53 gene in gastric and esophageal carcinogenesis

TP53 genes is one of more important tumor suppressor gene, which acts as a potent transcription factor with fundamental role in the maintenance of genetic stability. The development of esophageal and gastric cancers is a multistep process resulting in successive accumulation of genetic alterations that culminates in the malignant transformation. Thus, this study highlights the participation of the main genetic alterations of the TP53 gene in esophageal and gastric carcinogenesis. Among these changes, high frequency of TP53 mutations, loss of heterozygosity (LOH), overexpression of the p53 protein, and consequently loss of p53 function, which would be early events in esophageal and gastric cancers, as well as an important biomarker of the prognosis and treatment response. Furthermore, Single Nucleotide Polymorphisms (SNPs) of TP53 have been implicated in the development and prognosis of several cancers, mainly TP53 codon 72 polymorphism whose role has been extensively studied in relation to susceptibility for esophageal and gastric cancer development.

Immunohistochemical biomarkers in gastric cancer research and management

Gastric cancer still represents a major health problem, despite a decrease in its incidence in the last years. Due to the social impact of gastric cancer (GC), there is a need for novel biomarkers in order to stratify patients into appropriate screening, surveillance, or treatment programs. Although histopathology remains the most reliable and less expensive method, numerous efforts have been made searching for novel biomarkers. In recent years, several molecules have been identified and tested for their clinical relevance in GC management. In this paper, we will focus on a well-known GC marker, whose determination is mandatory in GC, HER2, a marker whose correlation with prognosis is still controversial (VEGF-A) and a quite novel, unconventional marker, the ether-à-go-go-related gene 1 (hERG1). All these proteins can be easily detected with immunohistochemistry, a technique widely used both in diagnostic and research laboratories that represents a link between surgical and molecular pathology, basic science, and clinical medicine.