Effect of cetuximab plus FOLFOX4 regimen on clinical outcomes in advanced gastric carcinoma patients receiving evidence-based care

BACKGROUND Although chemotherapy is effective for treating advanced gastric carcinoma(aGC),it may lead to an adverse prognosis.Establishing a highly effective and low-toxicity chemotherapy regimen is necessary for improving efficacy and outcomes in aGC patients.AIM To determine the efficacy and safety of cetuximab(CET)combined with the FOLFOX4 regimen(infusional fluorouracil,folinic acid,and oxaliplatin)as firstline therapy for patients with aGC,who received evidence-based care(EBC).METHODS A total of 117 aGC patients who received EBC from March 2019 to March 2022 were enrolled.Of these,60 in the research group(RG)received CET+FOLFOX4 as first-line therapy,whereas 57 in the control group(CG)received FOLFOX4.The efficacy[clinical response rate(RR)and disease control rate(DCR)],safety(liver and kidney dysfunction,leukopenia,thrombocytopenia,rash,and diarrhea),serum tumor marker expression[STMs;carbohydrate antigen(CA)19-9,CA72-4,and carcinoembryonic antigen(CEA)],inflammatory indicators[interleukin(IL)-2 and IL-10],and quality of life(QOL)of the two groups were compared.RESULTS A markedly higher RR and DCR were observed in the RG compared with the CG,with an equivalent safety profile between the two groups.RG exhibited notably reduced CA19-9,CA72-4,CEA,and IL-2 levels following treatment,which were lower than the pre-treatment levels and those in the CG.Post-treatment IL-10 was statistically increased in RG,higher than the pre-treatment level and the CG.Moreover,a significantly improved QOL was evident in the RG.CONCLUSION The CET+FOLFOX4 regimen is highly effective as first-line treatment for aGC patients receiving EBC.It facilitates the suppression of STMs,ameliorates the serum inflammatory microenvironment,and enhances QOL,without increased adverse drug effects.

Immunosuppressive tumor microenvironment in gastric signet-ring cell carcinoma

Gastric signet-ring cell carcinoma(GSRCC)is a subtype of gastric cancer with distinct phenotype and high risk of peritoneal metastasis.Studies have shown that early GSRCC has a good prognosis,while advanced GSRCC is insensitive to radiotherapy,chemotherapy or immune checkpoint blockade therapy.With technological advancement of single-cell RNA sequencing analysis and cytometry by time of flight mass cytometry,more detailed atlas of tumor microenvironment(TME)in GSRCC and its association with prognosis could be investigated extensively.Recently,two single-cell RNA sequencing studies revealed that GSRCC harbored a unique TME,manifested as highly immunosuppressive,leading to high immune escape.The TME of advanced GSRCC was enriched for immunosuppressive factors,including the loss of CXCL13+-cluster of differentiation 8+-Tex cells and declined clonal crosstalk among populations of T and B cells.In addition,GSRCC was mainly infiltrated by follicular B cells.The increased proportion of SRCC was accompanied by a decrease in mucosaassociated lymphoid tissue-derived B cells and a significant increase in follicular B cells,which may be one of the reasons for the poor prognosis of GSRCC.By understanding the relationship between immunosuppressive TME and poor prognosis in GSRCC and the underlying mechanism,more effective immunotherapy strategies and improved treatment outcomes of GSRCC can be anticipated.

MiR-204-3p overexpression inhibits gastric carcinoma cell proliferation by inhibiting the MAPK pathway and RIP1/MLK1 necroptosis pathway to promote apoptosis

BACKGROUND Gastric carcinoma(GC)is the third most frequent cause of cancer-related death,highlighting the pressing need for novel clinical treatment options.In this regard,microRNAs(miRNAs)have emerged as a promising therapeutic strategy.Studies have shown that miRNAs can regulate related signaling pathways,acting as tumor suppressors or tumor promoters.AIM To explore the effect of miR-204-3p on GC cells.METHODS We measured the expression levels of miR-204-3p in GC cells using quantitative real-time polymerase chain reaction,followed by the delivery of miR-204-3p overexpression and miR-204-3p knockdown vectors into GC cells.CCK-8 was used to detect the effect of miR-204-3p on the proliferation of GC cells,and the colony formation ability of GC cells was detected by the clonal formation assay.The effects of miR-204-3p on GC cell cycle and apoptosis were detected by flow cytometry.The BABL/c nude mouse subcutaneous tumor model using MKN-45 cells was constructed to verify the effect of miR-204-3p on the tumorigenicity of GC cells.Furthermore,the study investigated the effects of miR-204-3p on various proteins related to the MAPK signaling pathway,necroptosis signaling pathway and apoptosis signaling pathway on GC cells using Western blot techniques.RESULTS Firstly,we found that the expression of miR-204-3p in GC was low.When treated with the lentivirus overexpression vector,miR-204-3p expression significantly increased,but the lentivirus knockout vector had no significant effect on miR-204-3p.In vitro experiments confirmed that miR-204-3p overexpression inhibited GC cell viability,promoted cell apoptosis,blocked the cell cycle,and inhibited colony formation ability.In vivo animal experiments confirmed that miR-204-3p overexpression inhibited subcutaneous tumorigenesis ability in BABL/c nude mice.Simultaneously,our results verified that miR-204-3p overexpression can inhibit GC cell proliferation by inhibiting protein expression levels of KRAS and p-ERK1/2 in the MAPK pathway,as well as inhibiting protein expression levels of p-RIP1 and p-MLK1 in the necroptosis pathway to promote the BCL-2/BAX/Caspase-3 apoptosis pathway.CONCLUSION MiR-204-3p overexpression inhibited GC cell proliferation by inhibiting the MAPK pathway and necroptosis pathway to promote apoptosis of GC cells.Thus,miR-204-3p may represent a new potential therapeutic target for GC.

Quantitative parameters in novel spectral computed tomography:Assessment of Ki-67 expression in patients with gastric adenocarcinoma

BACKGROUND The level of Ki-67 expression has served as a prognostic factor in gastric cancer.The quantitative parameters based on the novel dual-layer spectral detector computed tomography(DLSDCT)in discriminating the Ki-67 expression status are unclear.AIM To investigate the diagnostic ability of DLSDCT-derived parameters for Ki-67 expression status in gastric carcinoma(GC).METHODS Dual-phase enhanced abdominal DLSDCT was performed preoperatively in 108 patients with gastric adenocarcinoma.Primary tumor monoenergetic CT attenuation value at 40-100 kilo electron volt(kev),the slope of the spectral curve(λ_(HU)),iodine concentration(IC),normalized IC(nIC),effective atomic number(Z^(eff))and normalized Z^(eff)(nZ^(eff))in the arterial phase(AP)and venous phase(VP)were retrospectively compared between patients with low and high Ki-67 expression in gastric adenocarcinoma.Spearman’s correlation coefficient was used to analyze the association between the above parameters and Ki-67 expression status.Receiver operating characteristic(ROC)curve analysis was performed to compare the diagnostic efficacy of the statistically significant parameters between two groups.RESULTS Thirty-seven and 71 patients were classified as having low and high Ki-67 expression,respectively.CT_(40 kev-VP),CT_(70 kev-VP),CT_(100 kev-VP),and Z^(eff)-related parameters were significantly higher,but IC-related parameters were lower in the group with low Ki-67 expression status than the group with high Ki-67 expression status,and other analyzed parameters showed no statistical difference between the two groups.Spearman’s correlation analysis showed that CT_(40 kev-VP),CT_(70 kev-VP),CT_(100 kev-VP),Z^(eff),and n Z^(eff) exhibited a negative correlation with Ki-67 status,whereas IC and nIC had positive correlation with Ki-67 status.The ROC analysis demonstrated that the multi-variable model of spectral parameters performed well in identifying the Ki-67 status[area under the curve(AUC)=0.967;sensitivity 95.77%;specificity 91.89%)].Nevertheless,the differentiating capabilities of singlevariable model were moderate(AUC value 0.630-0.835).In addition,the nZ_(VP)^(eff) and nIC_(VP)(AUC 0.835 and 0.805)showed better performance than CT_(40 kev-VP),CT_(70 kev-VP) and CT_(100 kev-VP)(AUC 0.630,0.631 and 0.662)in discriminating the Ki-67 status.CONCLUSION Quantitative spectral parameters are feasible to distinguish low and high Ki-67 expression in gastric adenocarcinoma.Z^(eff) and IC may be useful parameters for evaluating the Ki-67 expression.

Deltonin enhances gastric carcinoma cell apoptosis and chemosensitivity to cisplatin via inhibiting PI3K/AKT/mTOR and MAPK signaling

BACKGROUND As an active ingredient derived from Dioscorea zingiberensis C.H.Wright,deltonin has been reported to show anti-cancer effects in a variety of malignancies.AIM To investigate the role and mechanism of action of deltonin in promoting gastric carcinoma(GC)cell apoptosis and chemosensitivity to cisplatin.METHODS The GC cell lines AGS,HGC-27,and MKN-45 were treated with deltonin and then subjected to flow cytometry and 3-(4,5-dimethylthiazol-2-yl)-3,5-diphenyltet-razolium bromide assays for cell apoptosis and viability determination.Western blot analysis was conducted to examine alterations in the expression of apoptosis-related proteins(Bax,Bid,Bad,and Fas),DNA repair-associated proteins(Rad51 and MDM2),and phosphatidylinositol 3-kinase/protein kinase B/mammalian target of the rapamycin(PI3K/AKT/mTOR)and p38-mitogen-activated protein kinase(MAPK)axis proteins.Additionally,the influence of deltonin on GC cell chemosensitivity to cisplatin was evaluated both in vitro and in vivo.RESULTS Deltonin treatment weakened viability,enhanced apoptosis,and dampened DNA repair in GC cell lines in a dose-dependent pattern.Furthermore,deltonin mitigated PI3K,AKT,mTOR,and p38-MAPK phosphorylation.HS-173,an inhibitor of PI3K,attenuated GC cell viability and abolished deltonin inhibition of GC cell viability and PI3K/AKT/mTOR and p38-MAPK pathway activation.Deltonin also promoted the chemosensitivity of GC cells to cisplatin via repressing GC cell proliferation and growth and accelerating apoptosis.CONCLUSION Deltonin can boost the chemosensitivity of GC cells to cisplatin via inactivating p38-MAPK and PI3K/AKT/mTOR signaling.

Appraisal of gastric stump carcinoma and current state of affairs

Gastric stump carcinoma,also known as remnant gastric carcinoma,is a malignancy arising in the remnant stomach following gastrectomy for a benign or malignant condition.Enterogastric reflux and preexisting risk factors in a patient with gastric cancer are the major contributors to the development of gastric stump carcinoma.The occurrence of gastric stump carcinoma is time-dependent and seen earlier in patients operated on for malignant rather than benign diseases.The tumor location is predominantly at the anastomotic site towards the stomach.However,it can occur anywhere in the remnant stomach.The pattern of lymph node involvement and the type of surgery required is distinctly different compared to primary gastric cancer.Gastric stump carcinoma is traditionally considered a malignancy with a dismal outcome.However,recent advances in diagnostic and therapeutic strategies have improved outcomes.Recent advances in molecular profiling of gastric stump carcinoma have identified distinct molecular subtypes,thereby providing novel therapeutic targets.Also,reports of gastric stump carcinoma following pancreatoduodenectomy and bariatric surgery highlight the need for more research to standardize the diagnosis,staging,and treatment of these tumors.The present review aims to provide an overview of gastric stump carcinoma highlighting the differences in clinicopathological profile and management compared to primary gastric carcinoma.

Update on diagnosis and treatment of early signet-ring cell gastric carcinoma: A literature review

Gastric signet-ring cell gastric carcinoma(GSRC)is an unfavorable subtype of gastric cancer(GC)that presents with greater invasiveness and poorer prognosis in advanced stage than other types of GC.However,GSRC in early stage is often considered an indicator of less lymph node metastasis and more satisfying clinical outcome compared to poorly differentiated GC.Therefore,the detection and diagnosis of GSRC at early stage undoubtedly play a crucial role in the management of GSRC patients.In recent years,technological advancement in endoscopy including narrow-band imaging and magnifying endoscopy has significantly improved the accuracy and sensitivity of the diagnosis under endoscopy for GSRC patients.Researches have confirmed that early stage GSRC that meets the expanded criteria of endoscopic resection showed comparable outcomes to surgery after receiving endoscopic submucosal dissection(ESD),indicating that ESD could be considered standard treatment for GSRC after thorough selection and evaluation.This article summarizes the current knowledge and updates pertaining to the endoscopic diagnosis and treatment of early stage signet-ring cell gastric carcinoma.

Gastric adenosquamous carcinoma with an elevated serum level of alpha-fetoprotein:A case report

BACKGROUND Gastric adenosquamous carcinoma(ASC)is rare and characterized by coexisting of adenocarcinoma andsquamous carcinoma within the same tumor.We present a female patient with gastric ASC who had an elevated serum level of alpha-fetopro-tein(AFP),which decreased to normal levels after a laparoscopic distant radical gastrectomy in a short period.The clinicopathological features in AFP-producing gastric cancer(GC)are discussed,as well as potentially available prognostic predi-ctors.CASE SUMMARY A 50-year-old woman presented to our department with a chief complain of a 6-mo history of bloating.She had no basic diseases including heart diseases and respiratory diseases,and she also denied any prior history of dysphagia,hematemesis,melena,rectal bleeding,hematochezia,or unintentional weight loss.Based on her symptoms,an esophagogastroduodenoscopy was performed,showing an annular cavity lesion 3 cm from the pylorus with a diameter of 6 cm.A biopsy of the lesion showed gastric ASC,whereas the pylorus biopsy showed normal mucosa.The patient further received an enhanced computed tomography scan which demonstrated an invasive lesion close to the pylorus with a still clear margin of the tumor to peripheral organs such as the pancreas and liver.Scattered lymph nodes were visible around,whereas no sign of liver metastasis was discovered.Serum tumor markers including carcinoembryonic antigen(CEA),cancer antigen 199(CA199),CA724,CA125,and CA242 were all normal,while the level of serum AFP increased to 172 ng/mL.A laparoscopic distant radical gastrectomy was performed after exclusion of surgical contraindications.Postoperative pathology results showed that the tumor displayed an ulcerated ASC phenotype(90%of medium to highly-differentiated squamous cell carcinoma,10%of poorly differentiated adenocarcinoma.Surprisingly,the serum level of AFP decreased to normal level on post operation day 5.The tumor cells were positive for CK5/6,p63,and CEA,and negative for AFP and Epstein-Barr encoding region.CONCLUSION We presented a rare case of gastric ASC with elevated serum AFP level,which may be new subtype of AFP-producing GC.Follow-up detection of serum AFP might be a useful tool to predict patient prognosis.

Genomic characterization of peritoneal lavage cytology-positive gastric cancer

Objective: Positive peritoneal lavege cytology(CY1) gastric cancer is featured by dismal prognosis, with high risks of peritoneal metastasis. However, there is a lack of evidence on pathogenic mechanism and signature of CY1and there is a continuous debate on CY1 therapy. Therefore, exploring the mechanism of CY1 is crucial for treatment strategies and targets for CY1 gastric cancer.Methods: In order to figure out specific driver genes and marker genes of CY1 gastric cancer, and ultimately offer clues for potential marker and risk assessment of CY1, 17 cytology-positive gastric cancer patients and 31matched cytology-negative gastric cancer patients were enrolled in this study. The enrollment criteria were based on the results of diagnostic laparoscopy staging and cytology inspection of exfoliated cells. Whole exome sequencing was then performed on tumor samples to evaluate genomic characterization of cytology-positive gastric cancer.Results: Least absolute shrinkage and selection operator(LASSO) algorithm identified 43 cytology-positive marker genes, while Mut Sig CV identified 42 cytology-positive specific driver genes. CD3G and CDKL2 were both driver and marker genes of CY1. Regarding mutational signatures, driver gene mutation and tumor subclone architecture, no significant differences were observed between CY1 and negative peritoneal lavege cytology(CY0).Conclusions: There might not be distinct differences between CY1 and CY0, and CY1 might represent the progression of CY0 gastric cancer rather than constituting an independent subtype. This genomic analysis will thus provide key molecular insights into CY1, which may have a direct effect on treatment recommendations for CY1and CY0 patients, and provides opportunities for genome-guided clinical trials and drug development.

Expression of COX-2 in Different Subtypes of Gastric Intestinal Metaplasia and Gastric Carcinoma by Tissue Microarray

Objective: To study the expression of cyclooxygenase-2 (COX-2) protein in different subtypes of intestinal metaplasia (IM) and gastric carcinoma, evaluate the possibility of COX-2 forecasting the risk of malignant potential of IM, and the relationship between COX-2 expression and gastric carcinogenesis. Methods: Forty cases of chronic atrophic gastritis (CAG) with IM, 40 cases of gastric carcinoma and corresponding paracancerous tissues were selected to construct a tissue microarray. High iron diamine/alcian blue (HID/AB) staining and Hematoxylin and Eosin (HE) staining was used to classify IM and gastric carcinoma, and the expression of COX-2 protein detected in different subtypes of IM and gastric cancer by using immunohistochemistry. Results: The positive expression rate of COX-2 was 45.65%, 59.38% and 77.27% in IM foci in CAG, IM foci in paracancerous tissues, and intestinal-type gastric carcinoma, respectively, significantly higher than in diffuse-type gastric cancer (16.67%)(P<0.05, 0.005 and 0.005, respectively), and the expression intensity of COX-2 protein showed a increased tendency gradually in the sequence of IM foci in CAG→IM foci in paracancerous tissues→intestinal-type gastric carcinoma (P<0.005). The positive expression rate of COX-2 protein in type Ⅲ IM was significantly higher than in type Ⅰ and type Ⅱ IM (P<0.005 and 0.05, respectively), and the expression intensity also showed a increased tendency gradually from type Ⅰ to type Ⅲ IM (P<0.005). Conclusion: The expression level of COX-2 was increased gradually along with the increase of the risk of malignancy of IM, and its expression level may be a useful index to forecast the risk of malignant potential of IM. COX-2 expression was associated with intestinal-type gastric carcinoma, but it might also have some role in the carcinogenesis of diffuse-type gastric carcinoma.

Vascular Endothelial Growth Factor C Expression in Gastric Carcinoma and Its Relationship with Lymph Node Metastasis

Objective: To study the expression of vascular endothelial growth factor C (VEGF-C) in gastric carcinoma and its relationship with lymph node metastasis. Methods: The expression of VEGF-C mRNA in 5 gastric carcinoma cell lines was detected by reverse transcription-polymerase chain reaction (RT-PCR). Simultaneously, the expression of VEGF-C protein in gastric carcinoma tissues, which were obtained from 63 patients who underwent radical gastrectomy, was detected by immunohistochemistry. Results: Three of the 5 gastric carcinoma cell lines, MKN-45, SGC-7901 and AGS, expressed VEGF-C mRNA. VEGF-C protein was expressed in 52.4% (33/63) of patients. VEGF-C protein expression was more frequently found in tumors with lymph node metastasis than in those without (P<0.01). VEGF-C protein expression was also closely related to lymphatic invasion (P<0.01) and TNM stage (P<0.01). However, there was no significant correlation between VEGF-C expression and the age, gender, tumor size, tumor location, Lauren classification, depth of invasion, and vascular invasion. Conclusion: The expression of VEGF-C is closely related to lymph node metastasis of gastric carcinoma, and lymphangiogenesis might be a new target for treatment of gastric carcinoma.

The Relationship between the Expression of p27^(Kip1),p53 and the Infiltration,Metastasis and Prognosis in Gastric Carcinoma

Objective: To study the relationship between the expression of p27Kip1 and p53, and the infiltration, metastasis and prognosis in gastric carcinoma. Methods: The expression of p27Kip1 and p53 at protein level was determined by immunohistochemical assay (two-step method) in 100 cases of gastric carcinoma. Results: Of the 100 cases, the positive rate of p27Kip1 and p53 expressions were 44% and 49%, respectively. In the group of gastric carcinomas with deep infiltration (infiltration group), lymph nodes metastasis group (metastasis group) and death-within-5-years group (death group), the expression of p27Kip1 was statistically lower (_P<0.05). In the metastasis group and death group, the expression of p53 was significantly higher (P<0.05). The results of the monovariate analysis revealed that the 5-year survival rate of the high p27Kip1 expression group was 70.59%, which is higher than those of the low p27Kip1 expression group (54.55%) and the negative experession group (26%). The 5-year survival rate of the high p53 expression group was 19.23%, which was lower than those of the p53 low expression group (43.75%) and the negative group (53.19%). Cox multivariate analysis showed that p27Kip1, like p53, was an independent prognostic index. But p27Klpl protein expression was a stronger independent survival predictor (RR=3.06) than p53 expression (RR=2.33). Conclusion: The low expression of p27Kip1 and the high expression of p53 reflected the more frequent invasion and metastasis, which resulted in the reduced survival of patients. As an independent markers of the gastric carcinoma, the expression of p27Kip1 is more useful than that of p53 in the prognosis prediction of gastric carcinoma.

Role of the tumor microenvironment in the pathogenesis of gastric carcinoma

Gastric carcinoma (GC) is the 4th most prevalent cancer and has the 2nd highest cancer-related mortality rate worldwide. Despite the incidence of GC has decreased over the past few decades, it is still a serious health problem. Chronic inflammatory status of the stomach, caused by the infection of Helicobacter pylori (H. pylori) and through the production of inflammatory mediators within the parenchyma is suspected to play an important role in the initiation and progression of GC. In this review, the correlation between chronic inflammation and H. pylori infection as an important factor for the development of GC will be discussed. Major components, including tumor-associated macrophages, lymphocytes, cancer-associated fibroblasts, angiogenic factors, cytokines, and chemokines of GC microenvironment and their mechanism of action on signaling pathways will also be discussed. Increasing our understanding of how the components of the tumor microenviroment interact with GC cells and the signaling pathways involved could help identify new therapeutic and chemopreventive targets.

Downregulation of survivin by RNAi inhibits growth of human gastric carcinoma cells

AIM: To investigate the inhibitory effect of a specific small survivin interfering RNA (siRNA) on cell proliferation and the expression of survivin in human gastric carcinoma cell line SGC-7901. METHODS: To knockdown survivin expression, a small interfering RNA targeting against survivin was synthesized and transfected into SGC-7901 cells with lipofectamineTM2000. The downregulation of survivin expression at both mRNA and protein levels were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Cell proliferation inhibition rates were determined by methyl thiazolyl tetrazolium (MTT) assay. The effect of survivin siRNA on cell cycle distribution and cell apoptosis was determined by flow cytometry (FCM). RESULTS: RNA interference could efficiently suppress the survivin expression in SGC-7901 cells. At 48 h after transfection, the expression inhibition rate was 44.52% at mRNA level detected by RT-PCR and 40.17% at protein level by Western blot analysis. Downregulation of survivin resulted in significant inhibition of tumor cell growth in vitro. The cell proliferation inhibition rates at 24, 48 and 72 h after survivin siRNA and non-siliencing siRNA transfection, were 34.06%, 47.61% and 40.36%, respectively. The apoptosis rate was 3.56% and the number of cells was increased in G0/G1 phase from 38.2% to 88.6%, and decreased in S and G2/M phase at 48 h after transfection. CONCLUSION: Downregulation of survivin results in significant inhibition of tumor growth in vitro. The inhibition of survivin expression can induce apoptosis of SGC-7901 cells. The use of survivin siRNA deserves further investigation as a novel approach to cancer therapy.

Caveolin-1,E-cadherin and β-catenin in Gastric Carcinoma,Precancerous Tissues and Chronic Non-atrophic Gastritis

Objective： To investigate the expressions of caveolin-1, E-cadherin and β-catenin in gastric carcinoma, precancerous gastric and chronic non-atrophic gastritis tissues, and evaluate the correlation of these expressions with the development of gastric cancer. Methods： The expressions of caveolin-1, E-cadherin and β-catenin were detected by biotin-streptavidinperoxidase （SP） immunohistochemistry on 58 gastric cancer tissues, 40 precancerous gastric tissues and 42 chronic non-atrophic gastritis tissues. The correlation between the expressions of caveolin-1, E-cadherin and β-catenin, and the clinicopathologic parameters of gastric cancer was analyzed retrospectively. Results： The positive rates of caveolin-1 and E-cadherin expressions in gastric carcinoma were significantly lower than precancerous gastric and chronic non-atrophic gastritis tissues （P〈0.01）. An abnormal rate of β-catenin expression in gastric carcinoma was higher than precancerous gastric and chronic non-atrophic gastritis tissues （P〈0.01）. Moreover, low expressions of caveolin-1, E-cadherin and β-catenin correlated with tumor size, depth of invasion, lymph node metastasis and TNM stage （P〈0.05）. The positive rates of caveolin-1 and E-cadherin expressions decreased （P〈0.01）, while an abnormal rate of β-catenin expression increased inversely, with the degree of atypical hyperplasia （P〈0.01）. Caveolin-1 expression correlated positively with E-cadherin （r=0.41, P〈0.05）. Caveolin-1 （r=-0.36, P〈0.05） and E-cadherin （r=-0.45, P〈0.05） expressions negatively correlated with abnormal β-catenin expression. Conclusion： These results suggested that dysregulated expressions of caveolin-1, E-cadherin and β-catenin correlated with the development of gastric cancer and its biological behavior.

Detection of let-7a microRNA by real-time PCR in gastric carcinoma

AIM: To establish an accurate and rapid stem-loop reverse transcriptional real-time PCR (RT-PCR) method to quantify human let-7a miRNA in gastric cancer. METHODS: According to the sequence of let-7a miRNA,the stem-loop reverse transcriptional primer,the primers and quantitative MGB probes of real-time PCR were designed and synthesized. The dynamic range and the sensitivity of quantitative reverse transcriptional real-time PCR were determined. The levels of let-7a miRNA were examined in 32 gastric carcinoma samples by stem-loop RT-PCR method. RESULTS: The dynamic range and sensitivity of the let-7a miRNA quantification scheme were evaluated,the result showed the assay could precisely detect 10 copies of mature let-7a miRNA in as few as 0.05 ng of total RNA of gastric mucosa. The results of specificity analysis showed no fluorescence signal occurred even though 50 ng of human genomic DNA was added to the reverse transcription (RT) reaction. The expression level of let-7a miRNA in gastric tumor tissues was significantly lower compared to normal tissues in 14 samples from 32 patients. CONCLUSION: The stem-loop RT-PCR is a reliable method to detect let-7a miRNA which may play an important role in the development of gastric carcinoma.

Clinicopathologic characteristics of gastric carcinoma in elderly patients: A comparison with young patients

AIM:To examine the clinicopathologic features of elderly patients with gastric carcinoma and to investigate the relationship between prognosis and age.METHODS: We reviewed the hospital records of 2 014patients with gastric carcinoma retrospectively to compare the clinicopathologic findings in elderly (age ＞70 years) and young (age ＜36 years) patients during the period from 1986 to 2000 in a tertiary referral center in Gwangju, Korea. Overall survival was the main outcome measure.RESULTS: Of the 2 014 patients, 194 (9.6%) were in the elderly group and 137 (6.8%) were in the young group.The elderly and young patients had similar distributions with respect to depth of invasion, nodal involvement, hepatic metastasis, peritoneal dissemination, tumor stage at the initial diagnosis, and type of surgery. Synchronous multiple carcinomas were found in 14/194 (7.2%) of the elderly group and 4/137 (2.9%) of the young group (P＜0.05). Using the Borrmann classification, type Ⅳ was more frequent in the young patients than in the elderly patients (P＜0.05).Significantly more elderly patients had a well or moderately differentiated histology, and more young patients had a poorly differentiated histology and signet ring cell carcinoma (P＜0.001). The 5-year survival rates of elderly and young patients did not differ statistically (52.8% vs 46.5%,P = 0.5290). Multivariate analysis showed that the histologic type, nodal involvement and operative curability were significant prognostic factors, and age itself was not an independent prognostic factor of survival for elderly gastric carcinoma patients.CONCLUSION: Elderly patients with gastric carcinoma do not have a worse prognosis than young patients. The important prognostic factor is whether the patients undergo a curative resection.

Lymph node micrometastasis and its correlation with MMP-2 expression in gastric carcinoma

AIM： To examine matrix metalloproteinase-2 （MMP-2） expression in gastric cancer tissues and to evaluate its relationship with lymph node micrometastasis. MATERIALS： The authors studied 850 lymph nodes resected from 30 patients with gastric carcinoma who underwent gastrectomy with lymphadenetomy using reverse transcription polymerase chain reaction （RT-PCR） assay in addition to H-E staining. MMP-2 expression of the tumor tissues was detected by immunohistochemical technique （EliVision^TM plus）. RESULTS： MMP-2 expression was positive in 21 （70%） cases and negative in g （30%） cases. No significant correlations were found between MMP-2 expression and other variables such as age, gender, tumor location, tumor diameter, Lauren classification and lymphatic invasion. In contrast, MMP-2 expression correlated significantly with depth of tumor infiltration （P = 0.022）, lymph node metastasis （P = 0.030） and tumor differentiation （P = 0.043）. Lymph node micrometastases were detected in 77 （12.5%） lymph nodes of 14 （46.7%） gastric carcinoma patients. MMP-2 expression was positive in 12 （85.7%） of the 14 patients with lymph node micrometastasis, and in g （56.3%） of the 16 patients without lymph node micrometastasis （P = 0.118）. CONCLUSIONS： Our results demonstrate that MMP-2 expression has significant correlation with tumor invasion, tumor differentiation and lymph node metastases. MMP-2 expression may be an important biological characteristics and significant prognostic parameter of gastric carcinoma. We also conclude that MMP-2 may participate in the development of lymph node micrometastasis of gastric carcinoma. Further investigations are needed to draw a conclusion.

Effect and mechanism of the Twist gene on invasion and metastasis of gastric carcinoma cells

AIM: To study the effect of the transfected Twist gene on invasion and metastasis of gastric carcinoma cells and the possible mechanisms involved. METHODS: Human gastric carcinoma MKN28 cells were stably transfected with Twist sense plasmid, and MKN45 cells were stably transfected with Twist antisense plasmid using the lipofectamine transfection technique. RT-PCR, Western blotting, EMSA, gelatin zymography assay, and in vitro invasion and migration assays were performed. Nude mice metastasis models were established by the abdominal cavity transfer method. RESULTS: Cell models (TwistS-MKN28) that steadily expressed high Twist protein were obtained. Compared with MKN28 and pcDNA3-MKN28 cells, adherence, migration and invasion ability of TwistS -MKN28 cells were clearly raised. The number of cancer nodules was increased significantly in the abdominal cavity and liver of nude mice inoculated with TwistS-MKN28 cells. Overexpression of Twist in MKN28 cells increased Tcf-4/ Lef DNA binding activity, and promoted expression of Tcf-4’s downstream target genes cyclin D1 and MMP-2. However, suppression of Twist (TwistAS-MKN45) inhibited MKN45 cell invasion and the expression of cyclin D1 was reduced. The activity of MMP-2 was also decreased. CONCLUSION: These results indicate that Twist promotes gastric cancer cell migration, invasion and metastasis, and Twist may play an important role in Wnt/ Tcf-4 signaling.

Clinicopathologic significance of HER-2/neu protein expression and gene amplification in gastric carcinoma

AIM:To study the HER-2/neu protein expression and gene amplification in gastric carcinoma and their relation.METHODS:One hundred and forty-five formalin-fixed and paraffin-embedded tumor tissue samples from Chinese gastric carcinoma patients were studied with immunohistochemistry(IHC)and fluorescence in situ hybridization(FISH)methods.Clinicopathologic data about all patients were collected.RESULTS:The levels of HER-2 3+,HER-2 2+and HER21+were measurable in 6.9%,8.3%and 17.2%of the samples,respectively.No HER-2 was stained in 67.6% of the samples.FISH showed that HER-2 gene was amplified in 18 samples,10 HER-2 3+samples,5 HER-2 2+samples,and 3 HER-2 1+samples with IHC staining.HER-2 status was not correlated with the sex and age of patients,and tumor size,location or differentiation,but with the depth of invasion,TNM stage,lymph node and distant metastasis as well as histopathological classification of gastric cancer(P<0.05).CONCLUSION:All samples with IHC as HER-2 expression should be analyzed with FISH.Detection of HER-2 gene amplification can assess the malignant biological behaviors and prognosis of gastric cancer.