Expression of mucins and E-cadherin in gastric carcinoma and their clinical significance

MT1-MMP and TIMP-2 are first expressed in the colon glands after a single dose of azoxymethane (AOM)

Tissue inhibitor of metalloproteinase-2 (TIMP-2) and membrane-type 1-matrix metalloproteinase (MT1-MMP) are always expressed during the cancer process. The aim was to identify which regions of the colon mucosa MT1-MMP and TIMP-2 begin to express themselves, as well as to establish their expression in relation to cell proliferation and mucin production. After intraperitoneal injection of 15 mg/kg of azoxymethane (AOM) at 4, 12, and 20 weeks, histological sections of the middle segment of the rat colon mucosa were evaluated by immunohistochemistry for cell proliferation and expression of MT1-MMP and TIMP-2 and histochemistry for mucin. As a result, a single dose of AOM initially increased the intensity of MT1-MMP and TIMP-2 expression in the conjunctive cells and glands, concurrently with alterations in the distribution of the mucin produced in the gland of the large intestine mucosa and cell proliferation. As a result, at 4 and 12 weeks, a single dose of AOM initially stimulated the expression of MT1-MMP and TIMP-2 in the conjunctive cells and glands with greater intensity. Changes in the cell proliferation and distribution of the mucin produced in the large intestine mucosa gland were observed. We conclude that MT1-MMP and TIMP-2 were first and strongly expressed in all cells of the colon glands, concurrently with an increase in cell proliferation and a diffuse dispersion of mucin, indicating the onset of the dysplasia process following a single dosage of AOM.

The Role of Mucin Expression in the Diagnosis of Oesophago-Gastric Cancer: A Systematic Literature Review

Survival in oesophago-gastric cancer (OGC) is poor due to early diagnostic challenges. Non-invasive risk stratification may identify susceptible patients with pre-malignant or benign disease. Following diagnostic confirmation with endoscopic biopsy, early OGC may be treated sooner. Mucins are transmembrane glycoproteins implicated in OGC with potential use as biomarkers of malignant transformation. This systematic review defines the role of mucins in OGC diagnosis. A literature search of MEDLINE, Web of Science, Embase and Cochrane databases was performed following PRISMA protocols for studies published January 1960-December 2022. Demographic data and data on mucin sampling and analysis methods were extracted. The review included 124 studies (n = 11,386 patients). Gastric adenocarcinoma (GAc) was the commonest OG malignancy (n = 101) followed by oesophageal adenocarcinoma (OAc, n = 24) and squamous cell carcinoma (OSqCc, n = 10). Mucins MUC1, MUC2, MUC5AC and MUC6 were the most frequently implicated. High MUC1 expression correlated with poorer prognosis and metastases in OSqCc. MUC2 expression decreases during progression from healthy mucosa to OAc, causing reduced protection from gastric acid. MUC5AC was upregulated, and MUC6 downregulated in GAc. Mucin expression varies in OGC; changes may be epigenetic or mutational. Profiling upper GI mucin expression in OGC, with pre-malignant, benign and healthy controls may identify potential early diagnostic biomarkers.

Immunoexpression of E-cadherin, CD44 and Claudin 7 in gastric adenocarcinomas

Gastric adenocarcinomas represent frequent malignant tumors in the digestive tract, with a high and constant mortality rate in last decades. The disturbance of the adhesion molecules expression, which normally is essential in maintaining epithelial homeostasis, has a critical role in the initiation and progression of tumors. In this study, we analyzed the immunoexpression of E-cadherin, cluster of differentiation 44 (CD44), and Claudin 7 in 58 cases of gastric adenocarcinomas, in relation to the histopathological parameters of the lesions' aggressiveness. Increased E-cadherin immunoexpression was observed in tubular adenocarcinomas, those of low grade and in stages I-III. CD44 presented high scores in discohesive, hepatoid, tubular, and tubulopapillary adenocarcinomas, those of high grade and in advanced stages. Claudin 7 associated increased scores for tubular, tubulopapillary and micropapillary tumors, those of low grade and mainly in stage I. The markers used in the study can be useful for assessing the aggressiveness of gastric adenocarcinomas, in the context of specific adapted therapy.

Mucin 1 as a Molecular Target of a Novel Diisoquinoline Derivative Combined with Anti-MUC1 Antibody in AGS Gastric Cancer Cells

BACKGROUND

The aim of the study was to examine the molecular mechanism of the anticancer action of a monoclonal antibody against MUC1 and a diisoquinoline derivative (OM-86II) in human gastric cancer cells.

METHODS

The cell viability was measured by the MTT assay. The disruption of mitochondrial membrane potential and activity of caspase-8 and caspase-9 was performed by flow cytometry. Fluorescent microscopy was used to confirm the proapoptotic effect of compounds. LC3A, LC3B and Beclin-1 concentrations were analyzed to check the influence of the compounds on induction of autophagy. ELISA assessments were performed to measure the concentration of mTOR, sICAM1, MMP-2, MMP-9 and pro-apoptotic Bax.

RESULTS

The anti-MUC1 antibody with the diisoquinoline derivative (OM-86II) significantly reduced gastric cancer cells' viability. This was accompanied by an increase in caspase-8 and caspase-9 activity as well as high concentrations of pro-apoptotic Bax. We also proved that the anti-MUC1 antibody with OM-86II decreased the concentrations of MMP-9, sICAM1 and mTOR in gastric cancer cells. After 48 h of incubation with such a combination, we observed higher levels of the crucial component of autophagosomes (LC3) and Beclin-1.

CONCLUSIONS

Our study proved that the anti-MUC1 antibody sensitizes human gastric cancer cells to the novel diisoquinoline derivative (OM-86II) via induction of apoptosis and autophagy, and inhibition of selected proteins such as mTOR, sICAM1 and MMP-9.

Early detection of tumor cells in bone marrow and peripheral blood in a fast‑progressing gastric cancer model

Helicobacter pylori (H. pylori) infection is a major risk factor for the development of gastric cancer. The authors previously demonstrated that in mice deficient in myeloid differentiation primary response 88 (Myd88^−/−), infection with Helicobacter felis (H. felis) a close relative of H. pylori, subsequently rapidly progressed to neoplasia. The present study examined circulating tumor cells (CTCs) by measuring the expression of cytokeratins, epithelial-to-mesenchymal transition (EMT)-related markers and cancer stem cell (CSC) markers in bone marrow and peripheral blood from Myd88^−/− and wild-type (WT) mice. Cytokeratins CK8/18 were detected as early as 4 months post-infection in Myd88^−/− mice. By contrast, cytokeratins were not detected in WT mice even after 7 months post-infection. The expression of Mucin-1 (MUC1) was observed in both bone marrow and peripheral blood at different time points, suggesting its role in gastric cancer metastasis. Snail, Twist and ZEB were expressed at different levels in bone marrow and peripheral blood. The expression of these EMT-related markers suggests the manifestation of cancer metastasis in the early stages of disease development. LGR5, CD44 and CD133 were the most prominent CSC markers detected. The detection of CSC and EMT markers along with cytokeratins does reinforce their use as biomarkers for gastric cancer metastasis. This early detection of markers suggests that CTCs leave primary site even before cancer is well established. Thus, cytokeratins, EMT, and CSCs could be used as biomarkers to detect aggressive forms of gastric cancers. This information may prove to be of significance in stratifying patients for treatment prior to the onset of severe disease-related characteristics.

Mucin expression in gastric- and gastro-oesophageal signet-ring cell cancer: results from a comprehensive literature review and a large cohort study of Caucasian and Asian gastric cancer

BACKGROUND

The literature on the prognostic relevance of signet-ring cell (SRC) histology in gastric cancer (GC) is controversial which is most likely related to inconsistent SRC classification based on haematoxylin-eosin staining. We hypothesised that mucin stains can consistently identify SRC-GC and predict GC patient outcome.

METHODS

We performed a comprehensive literature review on mucin stains in SRC-GC and characterised the mucin expression in 851 Caucasian GC and 410 Asian GC using Alcian Blue (AB)-Periodic Acid-Schiff (PAS), MUC2 (intestinal-type mucin), and MUC5AC (gastric-type mucin). The relationship between mucin expression and histological phenotype [poorly cohesive (PC) including proportion of SRCs, non-poorly cohesive (non-PC), or mucinous (MC)], clinicopathological variables, and patient outcome was analysed.

RESULTS

Depending on mucin expression and cut-offs, the positivity rates of SRC-GC reported in the literature varied from 6 to 100%. Patients with MUC2 positive SRC-GC or SRC-GC with (gastro)intestinal phenotype had poorest outcome. In our cohort study, PC with ≥ 10% SRCs expressed more frequently MUC2, MUC5AC, and ABPAS (p < 0.001, p = 0.004 and p < 0.001, respectively). Caucasians with AB positive GC or combined ABPAS-MUC2 positive and MUC5AC negative had poorest outcome (all p = 0.002). This association was not seen in Asian patients.

CONCLUSIONS

This is the first study to suggest that mucin stains do not help to differentiate between SRC-GC and non-SRC-GC. However, mucin stains appear to be able to identify GC patients with different outcome. To our surprise, the relationship between outcome and mucin expression seems to differ between Caucasian and Asian GC patients which warrants further investigations.

Ramifications of secreted mucin MUC5AC in malignant journey: a holistic view

Heavily glycosylated secreted mucin MUC5AC, by the virtue of its cysteine-rich repeats, can form inter- and intramolecular disulfide linkages resulting in complex polymers, which in turn craft the framework of the polymeric mucus gel on epithelial cell surfaces. MUC5AC is a molecule with versatile functional implications including barrier functions to epithelial cells, host-pathogen interaction, immune cell attraction to sites of premalignant or malignant lesions and tumor progression in a context-dependent manner. Differential expression, glycosylation and localization of MUC5AC have been associated with a plethora of benign and malignant pathologies. In this era of robust technologies, overexpression strategies and genetically engineered mouse models, MUC5AC is emerging as a potential diagnostic, prognostic and therapeutic target for various malignancies. Considering the clinical relevance of MUC5AC, this review holistically encompasses its genomic organization, domain structure, glycosylation patterns, regulation, functional and molecular connotation from benign to malignant pathologies. Furthermore, we have here explored the incipient and significant experimental tools that are being developed to study this structurally complex and evolutionary conserved gel-forming mucin.

Differential expression of two genes Oct-4 and MUC5AC associates with poor outcome in patients with gastric cancer

Gastric cancer (GC) is the most frequent leading cause of cancer-associated mortality worldwide that is linked to poor prognosis due to the lack of appropriate biomarkers. Our aim was to evaluate the MUC5AC and Oct-4 expression levels in GC and to assess their association with clinical factors. Immunohistochemical analysis (IHC) and qRT-PCR were performed in GC patients to examine the MUC5AC and Oct-4 expression levels. The mRNA level of MUC5AC was significantly decreased in tumour tissues compared with non-cancerous tissues (1.11 ± 0.69 vs 3.7 ± 0.71; P = .024). On the other hand, Oct-4 mRNA level was upregulated in tumour tissues as compared to normal tissues (2. 86 ± 0.78 vs 0.87 ± 0.54; P = .0015). Decreased expression of MUC5AC was detected in 27 patients (67.5%), while high to moderate expression levels were observed in 13 cases (32.5%), but in normal tissues the expression levels of MUC5AC were increased (P = .001). The decreased expression of MUC5AC was associated with aggressive tumour characteristics, such as TNM stage (P = .023), histologic type (P = .012) and lymph node metastasis (P = .001). High expression of Oct-4 was detected in 24 tumour tissues (60%), while 16 cases (40%) showed low expression level. Increased Oct-4 expression was correlated with clinicopathological characteristics such TNM stage (P = .002), histologic type (P = .008) and lymph node metastasis (P = .001). Our results showed that high Oct-4 expression and the reduction of MUC5AC expression may be involved in the progression and an unfavorable prognosis of GC.

Effect of myeloid differentiation primary response gene 88 on expression profiles of genes during the development and progression of Helicobacter-induced gastric cancer

Background

Gastric cancer is one of the most common and lethal type of cancer worldwide. Infection with Helicobacter pylori (H. pylori) is recognized as the major cause of gastric cancer. However, it remains unclear the mechanism by which Helicobacter infection leads to gastric cancer. Furthermore, the underlying molecular events involved during the progression of Helicobacter infection to gastric malignancy are not well understood. In previous studies, we demonstrated that that H. felis-infected Myd88^−/− mice exhibited dramatic pathology and an accelerated progression to gastric dysplasia; however, the MyD88 downstream gene targets responsible for this pathology have not been described. This study was designed to identify MyD88-dependent genes involved in the progression towards gastric cancer during the course of Helicobacter infection.

Methods

Wild type (WT) and Myd88 deficient mice (Myd88^−/−) were infected with H. felis for 25 and 47 weeks and global transcriptome analysis performed on gastric tissue using MouseWG-6 v2 expression BeadChips microarrays. Function and pathway enrichment analyses of statistically significant, differential expressed genes (p < 0.05) were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) online tools.

Results

Helicobacter infection affected the transcriptional profile of more genes in Myd88^−/− mice compared to WT mice. Infection of Myd88^−/− mice resulted in the differential expression of 1,989 genes at 25 weeks (1031 up and 958 downregulated). At 47 weeks post-H.felis infection, 2,162 (1140 up and 1022 downregulated) were differentially expressed. The most significant differentially upregulated gene during Helicobacter infection in Myd88^−/− mice was chitinase-like 4 (chil4), which is involved in tissue remodeling and wound healing. Other highly upregulated genes in H. felis-infected Myd88^−/− mice included, Indoleamine 2,3-Dioxygenase 1 (Ido1), Guanylate binding protein 2 (Gbp2), ubiquitin D (Ubd), β₂-Microglobulin (B2m), CD74 antigen (Cd74), which have been reported to promote cancer progression by enhancing angiogenesis, proliferation, migration, metastasis, invasion, and tumorigenecity. For downregulated genes, the highly expressed genes included, ATPase H+/K+ transporting, alpha subunit (Atp4a), Atp4b, Mucin 5 AC (Muc5ac), Apolipoprotein A-1 (Apoa1), and gastric intrinsic factor (Gif), whose optimal function is important in maintaining gastric hemostasis and lower expression has been associated with increased risk of gastric carcinogenesis.

Conclusions

These results provide a global transcriptional gene profile during the development and progression of Helicobacter-induced gastric cancer. The data show that our mouse model system is useful for identifying genes involved in gastric cancer progression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3114-y) contains supplementary material, which is available to authorized users.

Comparison of the Expression of Cell Adhesion Molecule Markers (E-Cadherin and Syndecan-1) between Young and Older Age Patients with Gastric Carcinoma

AIM

The aim of this study was to evaluate the relationship between age and cell adhesion molecule markers (E-cadherin and syndecan-1).

MATERIALS AND METHODS

Forty-three cases of gastric carcinoma below the age of 50 were referred to our center in the period of 5 years (2003–2008). Forty-three gastric carcinoma above the age of 50 years were sex-matched with the first group. Expression of syndecan-1 and E-cadherin were evaluated by immunohistochemistry in a total of 86 gastric carcinomas accompanying with all the clinicopathological findings in each case.

RESULTS

The expression of syndecan-1 and E-cadherin did not show significant difference between two age groups; in addition, there were no significant differences in all the clinicopathological findings in these two age groups.

DISCUSSION

Gastric carcinoma in young and old age adults showed no significant difference in respect of the expression of cell adhesion molecule markers. Our result shows that young age alone cannot be predictive of more metastasis and invasion potential.

MUC1 Immunohistochemical Expression as a Prognostic Factor in Gastric Cancer: Meta-Analysis

MUC1, a member of the mucin family, is expressed in tumors of various human organs and may function as an antiadhesion molecule that inhibits cell-to-cell adhesion, inducing tumor metastasis, and served as a potential biomarker of tumor progression in early gastric cancer. However, its prognostic significance in gastric cancer is still in dispute. We performed a meta-analysis to evaluate the relationship between MUC1 expression and prognosis of gastric cancer. A total of ten eligible studies with 834 cases and 548 controls were included. MUC1 positive cases were highly positive in intestinal-type carcinomas (OR = 1.76, 95% CI: 1.27–2.44, P = 0.0008 fixed-effect), higher rate of vascular invasion (OR = 1.64, 95% CI: 1.13–2.39, P = 0.009 fixed-effect), and lymph node metastasis (OR = 2.10, 95% CI: 1.20–3.67, P = 0.01 random-effect), as well as lower 5-year survival rate (HR = 0.27, 95% CI: 0.11–0.66, P = 0.004 random-effect). However, the presence of MUC1 was not associated with gender, tumor size, histologic differentiation, and clinical stage. In summary, MUC1 is a prognostic factor in gastric cancer, which acts as a marker of poor outcome in patients with gastric cancer. Further clinical studies are needed to confirm the role of MUC1 in clinical practice.

Clinical Impact of the KL-6 Concentration of Pancreatic Juice for Diagnosing Pancreatic Masses

Background and Aim. Pancreatic juice cytology (PJC) is considered optimal for differentially diagnosing pancreatic masses, but the accuracy of PJC ranges from 46.7% to 93.0%. The aim of this study was to evaluate the clinical impact of measuring the KL-6 concentration of pancreatic juice for diagnosing pancreatic masses. Methods. PJC and the KL-6 concentration measurements of pancreatic juice were performed for 70 consecutive patients with pancreatic masses (39 malignancies and 31 benign). Results. The average KL-6 concentration of pancreatic juice was significantly higher for pancreatic ductal adenocarcinomas (PDACs) (167.7 ± 396.1 U/mL) and intraductal papillary mucinous carcinomas (IPMCs) (86.9 ± 21.1 U/mL) than for pancreatic inflammatory lesions (17.5 ± 15.7 U/mL, P = 0.034) and intraductal papillary mucinous neoplasms (14.4 ± 2.0 U/mL, P = 0.026), respectively. When the cut-off level of the KL-6 concentration of pancreatic juice was 16 U/mL, the sensitivity, specificity, and accuracy of the KL-6 concentration of pancreatic juice alone were 79.5%, 64.5%, and 72.9%, respectively. Adding the KL-6 concentration of pancreatic juice to PJC when making a diagnosis caused the values of sensitivity and accuracy of PJC to increase by 15.3% (P = 0.025) and 8.5% (P = 0.048), respectively. Conclusions. The KL-6 concentration of pancreatic juice may be as useful as PJC for diagnosing PDACs.

Evaluation of P53, E-cadherin, Cox-2, and EGFR protein immunoexpression on prognostic of resected gallbladder carcinoma

Background

Gallbladder carcinoma presents a dismal prognosis. Choice treatment is surgical resection that is associated a high levels of both morbidity and mortality. Best knowledgement of prognostic factors may result a better selection of patients either for surgical or multimodal treatment.

Aim

To evaluate tecidual immunoexpression of P53, E-cadherin, Cox-2, and EGFR proteins and to correlate these findings with resected gallbladder adenocarcinoma survival.

Methods

Clinical, laboratorial, surgical, and anatomopathological reports of a series of gallbladder adenocarcinoma patients were collected by individualized questionary. Total sample was 42 patients. Median of age was 72 years (35-87). There were seven men and 35 women. Lesion distribuition in according TNM state was the following: T1 (n=2), T2 (n=5), T3 (n=31), T4 (n=4). Twenty-three patients underwent radical resection (R0), while 19 palliative surgery (R1-R2). A block of tissue microarray with neoplasic tissue of each patient was confected. It was performed evaluation of P53, E-Caderine, COX-2, and EGFR proteins imunoexpression. These findings were correlated with overall survival.

Results

Five-year survival was 28%. The median of global survival was eight months. Only immunoexpression of EGFR protein was considered independent variable at multivariated analysis.

Conclusion

Final prognosis was influenced by over-expression of EGFR protein in tumoral tissue.

MUC2 Expression Is Correlated with Tumor Differentiation and Inhibits Tumor Invasion in Gastric Carcinomas: A Systematic Review and Meta-analysis

Background:

While MUC2 is expressed in intestinal metaplasia and malignant lesions, the clinicopathological significance of MUC2 expression is not fully elucidated in gastric carcinoma (GC).

Methods:

The present study investigated the correlation between MUC2 expression and clinicopathological parameters in 167 human GCs. In addition, to confirm the clinicopathological significance of MUC2 expression, we performed a systematic review and meta-analysis in 1,832 GCs.

Results:

MUC2 expression was found in 58 of 167 GCs (34.7%). MUC2-expressing GC showed lower primary tumor (T), regional lymph node (N), and tumor node metastasis (TNM) stages compared with GCs without MUC2 expression (p=.001, p=.001, and p=.011, respectively). However, MUC2 expression was not correlated with Lauren’s classification and tumor differentiation. In meta-analysis, MUC2 expression was significantly correlated with differentiation and lower tumor stage (odds ratio [OR], 1.303; 95% confidence interval [CI], 1.020 to 1.664; p = .034 and OR, 1.352; 95% CI, 1.055 to 1.734; p = .017, respectively) but not with Lauren’s classification, pN stage, or pTNM stage.

Conclusions:

MUC2 expression was correlated with a lower tumor depth and lower lymph node metastasis in our study; the meta-analysis showed a correlation of MUC2 expression with tumor differentiation and lower tumor depth.

Subcellular localization of KL-6 mucin in intraductal papillary mucinous neoplasm of the pancreas

This study aimed to clarify the expression profile of KL-6 mucin in intraductal papillary mucinous neoplasm (IPMN) and its relation to tumor malignancy. Expression of KL-6 mucin in 38 IPMNs (intraductal papillary mucinous adenoma (IPMA), 24 cases; minimally invasive intraductal papillary mucinous carcinoma (MI-IPMC), 8 cases; invasive carcinoma originating from IPMC (IC-IPMC), 6 cases) and 66 pancreatic ductal adenocarcinomas (PDACs) was evaluated immunohistochemically. IC-IPMCs and MI-IPMCs had positive staining of KL-6 mucin whereas 58% of IPMAs tested negative. Subcellular localization of KL-6 mucin varied among IPMNs whereas all of the PDAC had positive expression in the circumferential membrane and cytoplasm of cancer cells. IC-IPMCs and MI-IPMCs had a higher frequency of circumferential membrane and cytoplasmic localization of KL-6 mucin than did IPMAs. These results suggest that localization of KL-6 mucin could be used to predict the malignancy of IPMN.

The changes in MUC5AC expression in gastric cancer before and after Helicobacter pylori eradication

PURPOSE

To investigate MUC5AC expression in gastric cancer before and after Hp eradication.

METHODS

The MUC5AC protein and mRNA were detected in gastric cancer tissue by western blot and real time PCR protocols before and after Hp eradication (Hp positive group). Gastric cancer tissue without Hp infection served as the control group (Hp negative group).

RESULTS

The MUC5AC protein and mRNA expression was more significantly increased in gastric cancer after Hp eradication as compared to that before Hp eradication, but it was significantly lower than of the control group. The relative amount of MUC5AC in the well-differentiated cancer was higher than that of the moderately or poorly-differentiated cancer, in either Hp positive or control groups. The relative amount of MUC5AC in cancer tissues with more than five metastatic lymph nodes was significantly lower than that of the cancer tissues with five or less metastatic lymph nodes, and was significantly lower in the Hp positive group as compared to that of the control group.

CONCLUSIONS

The reduction of the MUC5AC might be related to gastric carcinogenesis caused by Hp and the progression of gastric cancer.

The co-expression of functional gastric proteins in dynamic gastric diseases and its clinical significance

Background

Pepsinogen C (PGC) and mucin1 (MUC1) are important physiologically functional gastric proteins; Mucin2 (MUC2) is an “ectopic” functional protein in intestinal metaplasia of gastric mucosa. We analyzed the co-expression of the above-mentioned three proteins in dynamic gastric diseases {superficial gastritis (SG)-atrophic gastritis (AG)--gastric cancer (GC)} as well as different histological types of gastric cancer in order to find molecular phenotypes of gastric cancer and precancerous disease and further explore the potential co-function of PGC, MUC1 and MUC2 in the occurrence and development of gastric cancer.

Methods

The SG-AG-GC sequence was 57-57-70 cases in this case–control study, respectively. Different histological types of GC were 28 cases of highly and moderately differentiated aden ocarcinoma (HMDA)、30 of poorly differentiated adenocarcinoma (PDA) and 12 of mucinous adenocarcinoma (MA) or signet ring cell carcinoma (SRCC). PGC, MUC1 and MUC2 expression in situ were detected in all 184 cases using immunohistochemistry.

Results

Both PGC and MUC1 had a significantly decreased expression in GC than in SG and AG (P < 0.0001 and P < 0.01, respectively); While MUC2 had a significant increased expression in AG than in SG and GC (P < 0.0001). Seven phenotypes of PGC, MUC1 and MUC2 co-expression were found in which PGC+/MUC1+/MUC2- phenotype took 94.7%(54/57) in SG group; PGC+/MUC1+/MUC2+ and PGC-/MUC1+/MUC2+ phenotype took 43.9% (25/57) and 52.6% (30/57) in AG; the phenotypes in GC group appeared variable; extraordinarily, PGC-/MUC1-/MUC2+ phenotype took 100% (6/6) in MA or SRCC group and had a statistical significance compared with others (P < 0.05).

Conclusions

Phenotypes of PGC, MUC1 and MUC2 co-expression in dynamic gastric diseases are variable. In SG group it always showed PGC+/MUC1+/MUC2- phenotype and AG group showed two phenotypes (PGC+/MUC1+/MUC2+ and PGC-/MUC1+/MUC2+); the phenotypes in GC group appeared variable but the phenotype of PGC-/MUC1-/MUC2+ may be a predictive biomarker for diagnosing MA or SRCC, or distinguishing histological MA or SRCC from tubular adenocarcinoma accompanied by mucinous secretion or signet ring cell scattered distribution.

Molecular biomarkers in esophageal, gastric, and colorectal adenocarcinoma

Cancers of the esophagus, stomach and colon contribute to a major health burden worldwide and over 20% of all cancer deaths. Biomarkers that should indicate pathogenic process and are measureable in an objective manner for these tumors are rare and not established in the clinical setting. In general biomarkers can be very useful for cancer management as they can improve clinical decision-making regarding diagnosis, surveillance, and therapy. Biomarkers can be different types of molecular entities (such as DNA, RNA or proteins), which can be detected, in different tissues or body fluids. However, more important is the type of biomarker itself, which allows diagnostic, prognostic or predictive analyses for different clinical problems. This review aims to systematically summarize the recent findings of genetic and epigenetic markers for gastrointestinal tumors within the last decade. While many biomarkers seem to be very promising, especially if used as panels, further development is urgently needed to address practical considerations of biomarkers in cancer treatment.

Effects of Helicobacter pylori infection on MUC5AC protein expression in gastric cancer

AIM

To investigate the effects of the expression of the MUC5AC protein in gastric cancer depending on the Helicobacter pylori (Hp) infection status.

MATERIALS & METHODS

The MUC5AC protein and mRNA were detected using western blot and real-time PCR protocols in gastric cancer tissue and stratified for Hp infection. Gastric mucus membranes near the cancer site serve as the control group.

RESULTS

The expression of MUC5AC protein and mRNA is significantly decreased in gastric cancer tissue (p < 0.05). The decrease was more significant in the Hp-infected group than in the Hp-uninfected group (p < 0.05).

CONCLUSION

The infection of Hp is correlated with a decrease in MUC5AC protein amount in gastric cancer tissue. The current result suggests that there may be a potential necessary link between Hp, MUC5AC and gastric cancer.

MUC1 drives c-Met-dependent migration and scattering

The transmembrane mucin MUC1 is overexpressed in most ductal carcinomas, and its overexpression is frequently associated with metastatic progression. MUC1 can drive tumor initiation and progression via interactions with many oncogenic partners, including β-catenin, the EGF receptor (EGFR) and Src. The decoy peptide protein transduction domain MUC1 inhibitory peptide (PMIP) has been shown to inhibit the tumor promoting activities of MUC1 in breast and lung cancer, including cell growth and invasion, and its usage suppresses metastatic progression in mouse models of breast cancer. To further characterize the reduced metastasis observed upon PMIP treatment, we conducted motility assays and observed that PMIP inhibits cell motility of breast cancer cells. To determine the mechanism by which PMIP inhibits motility, we evaluated changes in global gene transcription upon PMIP treatment, and identified a number of genes with altered expression in response to PMIP. Among these genes is the metastatic mediator, c-Met, a transmembrane tyrosine kinase that can promote cell scattering, migration, and invasion. To further investigate the role of c-Met in MUC1-dependent metastatic events, we evaluated the effects of MUC1 expression and EGFR activation on breast cancer cell scattering, branching, and migration. We found that MUC1 strongly promoted all of these events and this effect was further amplified by EGF treatment. Importantly, the effect of MUC1 and EGF on these phenotypes was dependent upon c-Met activity. Overall, these results indicate that PMIP can block the expression of a key metastatic mediator, further advancing its potential use as a clinical therapeutic.

Genomic and genetic alterations influence the progression of gastric cancer

Gastric cancer is one of the leading causes of cancer-related deaths worldwide, although the incidence has gradually decreased in many Western countries. Two main gastric cancer histotypes, intestinal and diffuse, are recognised. Although most of the described genetic alterations have been observed in both types, different genetic pathways have been hypothesized. Genetic and epigenetic events, including 1q loss of heterozygosity (LOH), microsatellite instability and hypermethylation, have mostly been reported in intestinal-type gastric carcinoma and its precursor lesions, whereas 17p LOH, mutation or loss of E-cadherin are more often implicated in the development of diffuse-type gastric cancer. In this review, we summarize the sometimes contradictory findings regarding those markers which influence the progression of gastric adenocarcinoma.

MUC1 as a Putative Prognostic Marker for Prostate Cancer

MUC1 is expressed on the apical surface of glandular epithelium. With functions including protection, adhesion and signaling, MUC1 has been implicated in prostate cancer. There are many splice variants, the best characterized of which are MUC1/1 and MUC1/2 which are determined by a SNP (rs4072037, 3506G>A).Blood DNA from the general population, BPH, sporadic and hereditary prostate cancer subjects were genotyped for the rs4072037 SNP. G allele frequencies were significantly reduced in hereditary prostate cancer (15%) compared to population, BPH or sporadic prostate cancer samples (27%, 39% and 26% respectively). In addition, the G allele was lost from 3 of 8 heterozygous sporadic prostate tumor samples compared to matched blood DNA. Bioinformatics analysis of MUC1 protein sequences provides insight into differences between the variants which may be functionally relevant. The literature indicates discrepancies between immuno-histochemical studies, possibly due to the variety of MUC1 epitopes targeting diverse regions of the molecule. The contradictory findings in cell lines highlight the problem associated with inadequate experimental systems.This is the first report of genetic differences in MUC1 between blood and prostatic cancer tissue. This finding is important as proof of principle, given that many association studies focus on blood DNA rather than on the tumor DNA. As yet, potential functional differences between splice variants has been paid little attention. Antibodies which discriminate between the variants and standardization of methods would help to clarify whether there is a role for MUC1 as a prognostic marker.

Signet-Ring Cell Adenocarcinoma of Sinonasal Tract: An Immunohistochemical Study of the Mucins Profile

Context.—Adenocarcinomas of the sinonasal tract are classified into 4 categories: salivary-type, intestinal-type, nonintestinal-type, and metastatic. Signet-ring cell carcinoma is the rarest form of intestinal-type adenocarcinoma. Only isolated cases have been reported in the literature.

Objective.—To evaluate clinical attributes, morphology, and immunohistochemistry in signet-ring cell carcinoma of the sinonasal tract.

Design.—Seventy-three cases of primary sinonasal adenocarcinomas were retrieved from the files. Only 5 signet-ring cell adenocarcinomas (tumors composed of more than 90% signet-ring cells) were identified. In all cases, clinical data and histologic slides were available and were reviewed. Consecutive tissue sections were immunostained with monoclonal antibodies against MUC2, MUC5AC, MUC5B, MUC6, p53 protein, and MIB-1.

Results.—Four of our 5 patients were woodworkers. They were treated by surgical excision and radiotherapy. Patient follow-up ranged from 11 to 84 months. Three patients presented an unfavorable evolution and died of metastatic spread. Microscopically, the tumors produced abundant mucin deposits, which accumulated in large extracellular pools. Tumor cells were predominantly signet-ring cells floating in the pools of mucin. The mucins profile was MUC2+, MUC5AC+, MUC5B+, and MUC6−. Eighty percent of cells were immunostained by p53 protein antibody and 60% cells with MIB-1 antibody.

Conclusions.—The mucin profile is similar to the profile described in digestive tract adenocarcinoma. It is not useful to differentiate between metastatic adenocarcinoma and primary intestinal-type sinonasal adenocarcinoma. Clinical data and immunochemistry with p53 protein and MIB-1 confirm that sinonasal signet-ring cell carcinoma is a high-grade and aggressive tumor.

Expression of liver-intestine cadherin and its correlation with lymph node metastasis in gastric cancer: can it predict N stage preoperatively?

BACKGROUND

Reliable method to predict lymph node metastasis is not yet available. In the present study, therefore, we examined LI-cadherin expression in human gastric cancer and attempted to find its relationship with clinicopathologic data, especially with lymph node metastasis. We also analyzed the expression in preoperative biopsy specimen to uncover its possibility of prognostication for lymph node metastasis.

METHODS

The paired preoperative endoscopic biopsy and postoperative resected specimens from 208 patients who had surgically been treated for gastric cancer were retrospectively analyzed immunohistochemically for expression of LI-cadherin.

RESULTS

There were 47 (22.6%) and 161 (77.4%) tumors which had positive and negative LI-cadherin expression, respectively. LI-cadherin expression was significantly correlated with tumor histology and lymph node metastasis: Furthermore, reduced expression of LI-cadherin was closely associated with tumor progression and lymph node metastasis in human gastric carcinoma. LI-cadherin expressions in both resected tumor and preoperative endoscopic tissues were found to be independent factors associated with lymph node metastasis.

CONCLUSIONS

There is a close association between reduced expression of LI-cadherin and lymph node metastasis in human gastric cancer. Immunohistochemical study of LI-cadherin is relatively simple compared to sentinel node navigation surgery, and it could be a practical prediction method for lymph node metastasis in patients with this malignancy.

E-cadherin expression pattern in primary colorectal carcinomas and their metastases reflects disease outcome

AIM: To investigate the changes that occur in E-cadherin expression during the process of metastasis in colorectal cancer.

METHODS: E-cadherin expression was detected by immunohistochemistry and two indices of expression were calculated which reflected the level of expression and the locations (membrane and cytoplasm). Univariate and multivariate survival analyses were used to assess the value of these two E-cadherin indices as predictors of both disease-free (DFS) and disease-specific (DSS) survival.

RESULTS: E-cadherin membrane index (MI), but not cytoplasmic index (CI), was significantly higher in primary tumors than their metastases (P = 0.0001). Furthermore, both primary tumor MI and CI were higher among the patients who developed subsequent metastasis (P = 0.022 and P = 0.007, respectively). Interestingly, both indices were higher in liver metastase compared to other anatomic sites (MI, P = 0.034 and CI, P = 0.022). The CI of the primary tumors was a significant predictor of DFS (P = 0.042, univariate analysis), with a strong inverse correlation between CI and DFS (P = 0.006, multivariate analysis). Finally, the MI of primary tumor proved to be a significant independent predictor of DSS, with higher indices being associated with a more favorable outcome (P = 0.016).

CONCLUSION: Examination of E-cadherin expression and distribution in colorectal tumors can be extremely valuable in predicting disease recurrence. The observation that aberrant cytoplasmic expression of E-cadherin can predict disease recurrence is obviously of great importance for both patients and clinicians, and significantly affects decisions concerning the therapy and management of the patients.

Relationships between mucinous gastric carcinoma, MUC2 expression and survival

AIM: To investigate the expression of the four secreted gel-forming mucins (MUC2, MUC5AC, MUC5B and MUC6) in a series of gastric carcinomas, classified according Laurén’s, Mulligan’s, WHO and Goseki’s classifications, with special attention to all the different components (major and minor) present in tumors and to follow up clinical data.

METHODS: Expression of MUC2, MUC5AC, MUC5B and MUC6 was investigated using immunohistochemistry and in situ hybridization.

RESULTS: Expression of secreted gel-forming mucins in gastric carcinoma was particularly complex, each mucin being not restricted to any histopathological type even considering all components (major and minor) present in a given tumor. There was a worst survival in patients with a higher content of mucus (Goseki II or IV) and high positive MUC2 expression.

CONCLUSION: Complexity of mucin gene expression patterns in gastric cancer may reflect a precise state of differentiation at the cell level not recognized in used morphologic classification systems. High expression of MUC2 was nevertheless associated with mucinous subtype of the WHO classification and with group II of Goseki’s classification identified by the major component of a particular tumor. The quantity and quality of mucus were related to survival.

Expression patterns of dysadherin and E-cadherin in lymph node metastases of colorectal carcinoma

Reduction/loss of E-cadherin is associated with the development and progression of many epithelial tumors, while in a limited number of neoplasms, E-cadherin is re-expressed in metastases. Dysadherin, recently characterized by members of our research team, has an anti-cell-cell adhesion function and downregulates E-cadherin in a posttranscriptional manner. Colorectal cancer (CRC) is one of the most common tumors in the developed world, and lymph node metastases are harbingers of aggressive behavior. The aim of the present study was to examine the dysadherin and E-cadherin expression patterns in lymph node metastases vs primary CRC. Dysadherin and E-cadherin expression was examined immunohistochemically in 78 patients with CRC, Dukes' stage C in the primary tumor and in one lymph node metastasis. Dysadherin was expressed in 42% while E-cadherin immunoreactivity was reduced in 45% of primary tumors. In lymph nodes, 33 and 81% of metastatic tumors were positive for dysadherin and E-cadherin, respectively. Dysadherin expression was not correlated with E-cadherin expression in the primary tumor with a reverse correlation evident in the lymph node metastases. Our results suggest that different mechanisms govern E-cadherin expression in the primary tumor and the corresponding lymph node metastases.

Characterization of gastric adenocarcinoma cell lines established from CEA424/SV40 T antigen-transgenic mice with or without a human CEA transgene

Background

Gastric carcinoma is one of the most frequent cancers worldwide. Patients with gastric cancer at an advanced disease stage have a poor prognosis, due to the limited efficacy of available therapies. Therefore, the development of new therapies, like immunotherapy for the treatment of gastric cancer is of utmost importance. Since the usability of existing preclinical models for the evaluation of immunotherapies for gastric adenocarcinomas is limited, the goal of the present study was to establish murine in vivo models which allow the stepwise improvement of immunotherapies for gastric cancer.

Methods

Since no murine gastric adenocarcinoma cell lines are available we established four cell lines (424GC, mGC3, mGC5, mGC8) from spontaneously developing tumors of CEA424/SV40 T antigen (CEA424/Tag) mice and three cell lines derived from double-transgenic offsprings of CEA424/Tag mice mated with human carcinoembryonic antigen (CEA)-transgenic (CEA424/Tag-CEA) mice (mGC2^CEA, mGC4^CEA, mGC11^CEA). CEA424/Tag is a transgenic C57BL/6 mouse strain harboring the Tag under the control of a -424/-8 bp CEA gene promoter which leads to the development of invasive adenocarcinoma in the glandular stomach. Tumor cell lines established from CEA424/Tag-CEA mice express the well defined tumor antigen CEA under the control of its natural regulatory elements.

Results

The epithelial origin of the tumor cells was proven by morphological criteria including the presence of mucin within the cells and the expression of the cell adhesion molecules EpCAM and CEACAM1. All cell lines consistently express the transgenes CEA and/or Tag and MHC class I molecules leading to their susceptibility to lysis by Tag-specific CTL in vitro. Despite the presentation of CTL-epitopes derived from the transgene products the tumor cell lines were tumorigenic when grafted into C57BL/6, CEA424/Tag or CEA424/Tag-CEA-transgenic hosts and no significant differences in tumor take and tumor growth were observed in the different hosts. Although no spontaneous tumor rejection was observed, vaccination of C57BL/6 mice with lysates from gastric carcinoma cell lines protected C57BL/6 mice from tumor challenge, demonstrating the tumorigenicity of the tumor cell lines in nontransgenic mice of the H-2^b haplotype.

Conclusion

These tumor cell lines grafted in different syngeneic hosts should prove to be very useful to optimize immunotherapy regimens to be finally tested in transgenic animals developing primary gastric carcinomas.

High expression of intestinal-type mucin (MUC2) in intraductal papillary mucinous neoplasms coexisting with extrapancreatic gastrointestinal cancers

OBJECTIVES

It is known that intraductal papillary mucinous neoplasm (IPMN) is associated with a high incidence of extrapancreatic neoplasms. We tried to uncover the characteristics and gene expressions of IPMNs that coexist with other extrapancreatic gastrointestinal cancers.

METHODS

We retrieved the surgical specimens from 54 IPMN patients, including 7 cases of IPMNs that coexisted with extrapancreatic gastrointestinal cancers. The immunohistochemical staining (p21, Bcl-2, p53, intestinal-type secretory mucin [MUC2], and MUC5AC) and the pathological subtypes of the tumor papillae (the intestinal type, pancreaticobiliary type, null type, or unclassified type) were analyzed.

RESULTS

MUC2 expression was noticed more frequently in the IPMN coexisting with extrapancreatic cancers (6/7) than in the IPMN without extrapancreatic cancers (18/47; P = 0.04). There were no differences in p21 (P = 0.12), p53 (P = 0.25), and MUC5AC (P = 1.0) expressions between the 2 groups. IPMN with extrapancreatic cancers was noticed in all subtypes of papillae.

CONCLUSIONS

Regardless of the subtypes of papillae, transcription of the MUC2 might be related with the synchronous extrapancreatic gastrointestinal cancer development that is seen with IPMN. Therefore, careful systemic surveillance is needed to detect coexisting gastrointestinal cancer for all the subtypes of IPMN with MUC2 expression.

Involvement of dysadherin and E-cadherin in the development of testicular tumours

Testicular neoplasms are comprised of a variety of histologically different forms, and their pathogenesis has not been elucidated. Dysadherin is a recently described cell membrane glycoprotein, which has an anticell–cell adhesion function and downregulates E-cadherin. In this study, we examined immunohistochemically the expression of E-cadherin and dysadherin in 120 testicular neoplasms (37 seminomas-26 classic, five spermatocytic and six anaplastic-, 45 embryonal carcinomas, 10 mixed germ cell tumours, two yolk sac tumours, 10 mature and eight immature teratomas and eight non-Hodgkin B-cell lymphomas), clinical stage I. The intensity, the expression pattern and the percentage of neoplastic cell staining was recorded and correlated with the histologic type and vascular/lymphatic invasion. Dysadherin was not expressed in non-neoplastic germ cells, neither in CIS/ITGCNU, but it was highly expressed in all types of germ cell tumours, that demonstrated either embryonic phenotype or somatic differentiation, in most terminally differentiated neoplasms, and in all lymphomas. Dysadherin expression did not correlate with vascular invasion. Increased dysadherin expression was correlated with aberrant E-cadherin expression in most tumours. In 17% of embryonal carcinomas colocalisation of dysadherin and membranous E-cadherin staining was noted. This is the first report on dysadherin expression and its association with E-cadherin in testicular tumours. Since dysadherin is not normally expressed in non-neoplastic testis, it is conceivable that it plays a role in the neoplastic transformation of germ cells. In testicular tumours, as in other neoplasms, dysadherin downregulates E-cadherin expression, at least in part.

Clinical significance of subcellular localization of KL-6 mucin in primary colorectal adenocarcinoma and metastatic tissues

AIM: To assess subcellular localization of KL - 6 mucin and its clinicopathological significance in colorectal carcinoma as well as metastatic lymph node and liver tissues.

METHODS: Colorectal carcinoma tissues as well as metastatic lymph node and liver tissues were collected from 82 patients who underwent colorectomy or hepatectomy. Tissues were subjected to immunohistochemical analysis using KL - 6 antibody.

RESULTS: Of the 82 colorectal carcinoma patients, 6 showed no staining, 29 showed positive staining only in the apical membrane, and 47 showed positive staining in the circumferential membrane and/or cytoplasm. Positive staining was not observed in non - cancerous colorectal epithelial cells surrounding the tumor tissues. The five - year survival rate was significantly lower in cases showing positive staining in the circumferential membrane and/or cytoplasm (63.0%) than those showing positive staining only in the apical membrane (85.7%) and those showing no staining (100%). Statistical analysis between clinicopathological factors and subcellular localization of KL - 6 mucin showed that KL - 6 localization in the circumferential membrane and/or cytoplasm was significantly associated with the presence of venous invasion (P = 0.0003), lymphatic invasion (P <  0.0001), lymph node metastasis (P < 0.0001), liver metastasis (P = 0.058), and advanced histological stage (P < 0.0001). Positive staining was observed in all metastatic lesions tested as well as in the primary colorectal carcinoma tissues.

CONCLUSION: The subcellular staining pattern of KL - 6 in colorectal adenocarcinoma may be an important indicator for unfavorable behaviors such as lymph node and liver metastasis, as well as for the prognosis of patients.

Clinicopathological significance of KAI 1 and nm23-H1 expression in gastric cancer

AIM: To investigate the expression of KAI 1 and nm23-H₁ protein in gastric cancer, and to explore the clinicopath-ological significance of KAI 1 protein in the progression of gastric cancer.

METHODS: Eighty-seven paraffin-embedded specime-ns of gastric cancer were investigated immunohistoche-mically by Envision method with rabbit anti-human KAI 1 polyclonal antibody and mouse anti-human nm23-H₁ monoclonal antibody. Statistical analysis was perform-ed using chi-square test.

RESULTS: The positive rate of KAI 1 expression in gastric cancer with lymph node metastasis (60%, 39/65) was significantly lower than that without lymph node metastasis (95%, 21/22, P < 0.05), but the rate was markedly higher in early-stage tissues of gastric cancer than that in late-stage ones (94%, 16/17 vs 63%, 44/70, P < 0.05). The patients with KAI 1 positive tumor tended to have a longer survival time (P < 0.05). The expression of nm23-H₁ was notably decreased in gastric cancer with lymph node metastasis in compari-son with that without lymph node metastasis (18% vs 77%, P < 0.05), but nm23-H₁ expression rate in early- and meta-phase gastric cancers was higher than that in late-phase gastric cancers (65% vs 26%, P < 0.05).

CONCLUSION: KAI 1 and nm23-H₁ are both associat-ed with invasive ability of gastric cancer. Furthermore, KAI 1 is correlated with prognosis of patients with gast-ric cancers. Combined detection of KAI 1 and nm23-H₁ may be helpful in predicting the prognosis and further directing the clinical therapy of gastric cancer.

Prognostic significance of combined expression of MUC1 and adhesion molecules in advanced gastric cancer

The objective of the present study was to evaluate the combination of MUC1 and the status of adhesion molecules in advanced gastric cancers as a possible predictor of patient survival. Two hundred and two paraffin-embedded specimens of gastric carcinoma were examined by immunohistochemical staining using monoclonal antibodies against MUC1 mucin, E-cadherin and beta-catenin. The expression of MUC1 was considered positive if at least 10% of the neoplastic cells were stained. E-cadherin and beta-catenin were classified into four groups. Only a membranous pattern, which was stained as strongly as normal epithelial cells, was judged as normal. The absent pattern (loss of staining), cytoplasmic pattern (cytoplasmic staining with loss of membranous expression), and heterogeneous pattern (cytoplasmic staining with preservation of membranous expression) were considered abnormal. There was a significant relationship between MUC1-positive expression and abnormal expression of E-cadherin (P=0.017). The cancer with abnormal E-cadherin expression or MUC1-positive expression increased, indicating that the cancer invasion was deep. Survival analysis of the outcome revealed that the survival time for those with abnormal E-cadherin/MUC1-positive expression was shorter than for those with other expression patterns. Multivariate analysis revealed that patients with abnormal E-cadherin/MUC1-positive expression had a poorer prognosis with significance (P<0.0001). In conclusion, abnormal E-cadherin/MUC1-positive expression pattern in advanced gastric cancer is an independent unfavorable prognostic marker.

Gene deregulation in gastric cancer

Despite its decreasing frequency in the Western world during recent decades, gastric cancer is still one of the leading causes of cancer-related deaths worldwide. Due to the oligosymptomatic course of early gastric cancer, most cases are diagnosed in the advanced stages of the disease. The curative potential of current standard treatment continues to be unsatisfactory, despite multimodal approaches involving surgery, chemotherapy and radiotherapy. Novel therapeutics including small molecules and monoclonal antibodies are being developed and have been partially introduced into clinical use in connection with neoplastic diseases such as chronic myeloid leukemia, non-Hodgkin's lymphoma and colorectal cancer. Thorough understanding of the changes in gene expression occurring during gastric carcinogenesis may help to develop targeted therapies and improve the treatment of this disease. Novel molecular biology techniques have generated a wealth of data on up- and down-regulation, activation and inhibition of specific pathways in gastric cancer. Here, we provide an overview of the different aspects of aberrant gene expression patterns in gastric cancer.

MUC2 antisense oligodeoxynucleotide inhibits proliferation of human gastric carcinoma cells in vitro

AIM: To investigate the inhibitory effect of mucin gene (MUC2) antisense oligodeoxynucleotides (ASODNs) on proliferation of gastric cancer cells SGC7901.

METHODS: Phosphorothioate MUC2 ASODNs were synthesized and then transfected into gastric carcinoma SGC7901 cells mediated by lipofectin. The inhibitory effects on cell proliferation were determined by MTT method, light and electronic microscopy, flow cytometry (FCM) and immunohistochemistry.

RESULTS: MUC2 ASODN at varied concentration significantly inhibited the growth of SGC7901 cells in a dose- and time-dependent manner. The inhibitory peak appeared at 48th hour after transfection, and the inhibition rate reached 55% when the concentration of MUC2 ASODN was 0.5 mol/L. After transfected with MUC2 ASODN, SGC7901 cells decreased in number, volume and karyokinesis, increased in necrosis under light microscopy. And most of the cells arrested in S phase. Swollen mitochondrion, increased liposomes, myelin figures, chromatin margination were found under electronic microscopy. Immunohistochemistry indicated that after transfected with MUC2 ASODN, the expression of MUC2 and nm23 protein were down-regulated, but the expression of p16 protein was up-regulated.

CONCLUSION: MUC2 ASODN transfection can significantly inhibit the proliferation of gastric carcinoma SGC7901 cells.