Considering the indication of adjuvant therapy, the recurrence risk for primary gastrointestinal stromal tumor (GIST) after surgery needs to be accurately estimated. However, current risk stratification schemes may still have room for improvement. This study seeks to analyze prognostic factors for primary GISTs from 3 aspects, including clinicopathological parameters, immunohistochemical biomarkers, and gene mutational status, and attempts to find novel valuable factors predicting the malignancy potential of GISTs.Retrospective data from 114 primary GIST patients after R0 resection were collected. Clinicopathological data was obtained from medical records and re-evaluated. Immunohistochemical analysis was performed using the Tissue Microarray method for Ki67, p16, p27, p53, SKP2, CD133, and actin. KIT gene exons 9, 11, 13, and 17 and PDGFRα gene exons 12 and 18 were tested for mutations using PCR.Univariate analysis revealed the following factors as poor prognostic indicators for relapse-free survival with a median follow-up of 50 months: male gender, gastrointestinal bleeding, mitotic index >5/50HPFs, tumor size >5 cm, non-gastric site, necrosis, epithelioid or mixed cell type, surrounding tissue invasion, Ki67>5%, p16>20%, p53 index >10, SKP2>10%, and KIT exon 11 deletion. Besides mitotic index, tumor size and site, SKP2 high expression (RR = 2.91, 95% CI: 1.41-5.99, P = 0.004) and KIT exon 11 deletion (RR = 2.73, 95% CI: 1.04-7.16, P = 0.041) were also independent risk factors in multivariate analysis, with gastrointestinal bleeding also showing a trend towards significance (RR = 1.88, 95% CI: 0.98-3.64, P = 0.059). In addition, gastrointestinal bleeding and SKP2 high expression showed a good ability to stratify high-risk patients further.Our results show that gastrointestinal bleeding, SKP2 high expression, and KIT exon 11 deletions may be useful indicators of high recurrence risk for primary GIST patients.

Aim:

Vasodilator-stimulated phosphoprotein (VASP) expression is upregulated in human cancers and correlates with more invasive advanced tumor stages. The aim of this study was to elucidate the mechanisms by which matrine, an alkaloid derived from Sophora species plants, acted on the VASP protein in human gastric cancer cells in vitro.

Methods:

VASP was expressed and purified. Intrinsic fluorescence spectroscopy was used to study the binding of matrine to VASP. CD spectroscopy was used to examine the changes in the VASP protein secondary structure. Human gastric carcinoma cell line BGC823 was tested. Scratch wound and cell adhesion assays were used to detect the cell migration and adhesion, respectively. Real-time PCR and Western blot assays were used to measure mRNA and protein expression of VASP.

Results:

In the fluorescence assay, the dissociation constant for binding of matrine to VASP protein was 0.86 mmol/L, thus the direct binding between the two molecules was weak. However, matrine (50 μg/mL) caused obvious change in the secondary structure of VASP protein shown in CD spectrum. Treatments of BGC823 cells with matrine (50 μg/mL) significantly inhibited the cell migration and adhesion. The alkaloid changed the subcellular distribution of VASP and formation of actin stress fibers in BGC823 cells. The alkaloid caused small but statistically significant decreases in VASP protein expression and phosphorylation, but had no significant effect on VASP mRNA expression.

Conclusion:

Matrine modulates the structure, subcellular distribution, expression and phosphorylation of VASP in human gastric cancer cells, thus inhibiting the cancer cell adhesion and migration.

BACKGROUNDAIMS: To determine the efficacy and toxicity of docetaxel as a third-line therapy for patients with relapsed gastric cancer who have undergone modified oxaliplatin-fluorouracil (m-FOLFOX)-4 and modified irinotecan-fluorouracil (m-FOLFIRI) regimens.We analyzed 33 patients who had been histologically diagnosed with adenocarcinoma of the stomach and who had progressed after m-FOLFOX-4 and m-FOLFIRI regimens. Patients were treated with cycles of 75 mg/m(2) docetaxel on day 1 every 3 weeks.The median age of the patients was 56.0 years (range, 31.0 to 74.0), and 73% of the patients (24/33) had an Eastern Cooperative Oncology Group performance status of 0 or 1. All patients were evaluated in terms of tumor response: five (15%), nine (27%), and 19 (58%) patients experienced a partial response, stable disease, and progressive disease, respectively. The median time to progression was 2.1 months (95% confidence interval [CI], 1.63 to 2.58), and overall survival was 4.7 months (95% CI, 3.20 to 6.20), from the start of the docetaxel regimen. Assessing patients' toxicity profiles, the median number of cycles was 2.0 (range, 1.0 to 12.0). The major hematologic toxicities included grade 3 to 4 neutropenia (19/33, 58%), grade 3 to 4 thrombocytopenia (2/33, 6%), and grade 3 to 4 anemia (5/33, 15%). Neutropenic fever developed in three patients (3/33, 9%). The nonhematological toxicities were nausea and vomiting (10/33, 30%), abdominal pain (4/33, 12%), skin rash (1/33, 3%), and fluid retention (3/33, 9%).Docetaxel is a feasible third-line therapy regimen for patients with advanced gastric cancer after m-FOLFIRI and m-FOLFOX-4 regimens.

Recent studies indicate that β-elemene, a compound isolated from the Chinese herbal medicine Curcuma wenyujin, is capable of reversing tumor MDR, although the mechanism remains elusive. In this study, β-Elemene treatment markedly increased the intracellular accumulation of doxorubicin (DOX) and rhodamine 123 in both K562/DNR and SGC7901/ADR cells and significantly inhibited the expression of P-gp. Treatment of SGC7901/ADR cells with β-elemene led to downregulation of Akt phosphorylation and significant upregulation of the E3 ubiquitin ligases, c-Cbl and Cbl-b. Importantly, β-elemene significantly enhanced the anti-tumor activity of DOX in nude mice bearing SGC7901/ADR xenografts. Taken together, our results suggest that β-elemene may target P-gp-overexpressing leukemia and gastric cancer cells to enhance the efficacy of DOX treatment.

Growing evidence suggests that phospholipase A2 (PLA2) plays a pivotal role in tumorigenesis in human gastrointestinal cancer. One of the well-studied isoforms of PLA2, group IIA PLA2 (PLA2G2A), appears to exert its protumorigenic or antitumorigenic effects in a tissue-specific manner. The present study was designed to determine the expression profile and prognostic value of PLA2G2A in gastric cancer in a large Chinese cohort. By using real-time polymerase chain reaction, the amount of PLA2G2A messenger RNA in 60 pairs of fresh gastric tumors and adjacent noncancerous mucosa was measured. The immunostaining of PLA2G2A in 866 gastric cancers with paired noncancerous tissues was assayed. No expression of PLA2G2A was found in normal gastric mucosa, and focal expression of PLA2G2A was noticed in intestinal metaplasia, whereas significantly increased expression of PLA2G2A was observed in the cytoplasm of gastric cancer cells. Furthermore, the extent of PLA2G2A expression was associated with tumor size (P < .001), tumor differentiation (P = .001), T class (P < .001), N class (P < .001), and TNM stage (P < .001) of gastric cancer. Multivariate analysis showed that PLA2G2A expression was an independent predictor of survival for patients with gastric cancer (P = .024). Expression of PLA2G2A seems to be protective for patients with gastric cancer (hazard ratio, 1.423; 95% confidence interval, 1.047-1.935), and it may be a target for achieving better treatment outcomes.

BACKGROUND AND AIM:

Recently, the use of additional surgery after non-curative endoscopic resection has gradually increased due to the rapid spread of endoscopic treatments in selected patients with early gastric cancer. Sentinel node navigation surgery (SNNS) has also been recognized as a minimally invasive surgery with personalized lymphadenectomy in early gastric cancer. Here, we assessed the feasibility of SNNS after non-curative endoscopic resection for early gastric cancer.

METHODS:

Sixteen patients with early gastric cancer, in whom additional surgery had been indicated due to non-curative endoscopic resection, were enrolled. They underwent a gastrectomy with standard lymphadenectomy. One day before surgery, (99m) technetium-tin colloid was endoscopically injected into the submucosa around the tumor. After surgery, the uptake of radioisotope in dissected lymph nodes was measured using Navigator GPS. Then, all dissected lymph nodes were investigated by hematoxylin-eosin (HE) staining and immunohistochemistry (IHC) using an anti-human cytokeratin monoclonal antibody.

RESULTS:

HE staining demonstrated lymph node metastasis in 2 (12.5%) of 16 patients and in 3 (0.8%) of 382 nodes. However, IHC showed that none of the patients had lymph node micrometastasis. Sentinel nodes (SNs) were identified in all patients. The mean number of SNs was 3.1 (range, 1-6). Among 2 patients with lymph node metastasis, the SNs, at least, contained positive nodes. Accordingly, the false-negative and accuracy rates were 0% and 100%, respectively.

CONCLUSION:

Our results indicate that SNNS may have potential as a further minimally invasive surgery in early gastric cancer patients after non-curative endoscopic resection.

BACKGROUND:

Amplification and overexpression of human epidermal growth factor receptor-2 (HER-2) has been shown in subgroups of gastric cancer, correlated to more aggressive disease and predictive for the treatment with HER-2 antibodies. In this study, we examined the prognostic value of HER-2 expression in primary gastric cancer and in associated lymph node metastases and confirmed the role of HER-2 in tumor angiogenesis by examining vascular endothelial growth factor (VEGF) expression.

METHODS:

Immunohistochemistry was used to detect HER-2 and VEGF expression in 110 gastric cancer specimens and associated lymph node metastases and in 96 specimens of normal gastric mucosa.

RESULTS:

The expression level of HER-2 in gastric tissues was significantly higher than in normal tissues (19.1 % vs. 8.3 %; P < 0.05). HER-2 overexpression was homogeneous in primary gastric cancer and metastatic lymph nodes (P = 0.607). There was a significant positive correlation of HER-2 expression and VEGF expression (P = 0.007). HER-2 overexpression in primary tumor correlated with lymph node metastasis, distant metastasis, and American Joint Committee on Cancer (AJCC) stage. Cox regression multivariate analyses confirmed that tumor size, histological grade, lymph node ratio, AJCC stage, chemotherapy, and HER-2 expression were all prognostic factors. Patients with HER-2 positivity in both primary and metastatic tissues (+/+) had the poorest survival (OS, 12.5 months; DFS, 11.0 months) (P < 0.01).

CONCLUSIONS:

HER-2 was significantly overexpressed in gastric cancer versus normal tissue and correlated with VEGF expression. HER-2 in tumor or lymph nodes was an independent negative prognostic factor.

Flotillin gene is known as a tumor promoter or suppressor, depending on the tumor type or tumor stage. We aimed to investigate the clinical significance of flotillin2 protein expression in gastric cancer.We examined flotillin2 and erbB2 levels in tissue microarray of 282 gastric cancer samples and analyzed the association between flotillin2 levels, clinicopathologic factors and prognosis. The regulation of erbB2 by flotillin2 was examined with flotillin2 siRNA-transfected gastric cancer cells.Flotillin2 partially co-localized with erbB2 at the plasma membrane as detected by confocal microscopy, levels of erbB2 were reduced after flotillin knockdown in SGC-7901 cancer cells, and the expression of flotillin2 was positively correlated with that of erbB2. In non-neoplastic gastric mucosa, flotillin2 was not expressed in the epithelial compartment. In gastric cancer, positive staining of flotillin2 was shown in 129 (45.7%) of 282 cases, also, it was significantly associated with a Lauren grade, histologic type, lymphovascular invasion and tumor location. Moreover, survival analysis showed that flotillin2 expression was an independent prognostic factor of poor survival (p<0.001).These results indicate that a positive correlation exists between flotillin2 and erbB2 expression levels, flotillin2 maybe involved in the stabilization of erbB2 at the plasma membrane, flotillin2 is significantly correlated with cancer progression and poor prognosis in gastric cancer.

BACKGROUND:

Adjuvant chemotherapy is gaining an increasing role in resectable gastric cancer. Customizing chemotherapy on the basis of chemosensitivity may improve outcome, and putative predictive molecular markers have been mostly evaluated in Asian patients. We profiled key DNA and damage signaling factors and correlated them with outcome, in a European cohort.

METHODS:

Formalin-fixed tumor samples obtained from surgical specimens of patients treated with adjuvant cisplatin-based chemotherapy for gastric cancer were analyzed. Immunohistochemistry (IHC) was performed to analyze excision repair cross-complementing gene 1 (ERCC1) and thymidylate synthase (TS) expression, and p53 mutations were detected with direct sequencing.

RESULTS:

Among the 68 patient recruited, the median age was 69 (range 30-74), and UICC stage was III in 44 patients (65 %). With a median follow-up of 40.5 months, disease-free and overall survival were 18.0 (95 % CI 13.4-22.76) and 56 months (95 % CI 44.87-67.13), respectively. ERCC1 score was 0 in 14 out 67 (21 %) cases, 1 in 19 (28 %), 2 in 20 (30 %) and 3 in 14 cases (21 %). Longer overall survival (p = 0.04) was found in patients categorized as ERCC1 negative by IHC according to median score. TS score was 0 in 16 out 67 (24 %) cases, 1 in 27 (40 %), 2 in 16 (24 %) and 3 in 8 cases (12 %). Mutations of p53 were found in 21 out 66 (32 %) cases. Neither TS nor p53 were found to correlate with outcome.

CONCLUSION:

Excision repair cross-complementing gene 1 by IHC might predict patients more likely to benefit from adjuvant cisplatin-based chemotherapy in curatively resected gastric cancer. In patients exhibiting ERCC1 positive tumors, alternative regimens should be evaluated.

Objective To investigate the anti-tumor effect of celecoxib combined with tegafur gimeracil oteracil potassium on subcutaneous xenograft tumor of gastric cancer in nude mice and analyze the possible mechanism. Methods A xenograft tumor model of gastric cancer was established subcutaneously in nude mice. After the largest diameter of tumor reached about 5 mm, the nude mice were randomly divided into 4 groups: the control group, the celecoxib group, the tegafur gimeracil oteracil potassium group, and the combination group; the drug was administered respectively for 21 days. Thereafter, tumor tissues were collected, tumor volume was measured, and tumor inhibition rate was calculated. Apoptosis was determined by TUNEL assay and the expression levels of PCNA, Bcl-2 and caspase-3 by immunohistochemistry. Results The tumor inhibition rates of the celecoxib group, the tegafur gimeracil oteracil potassium group, the combination group were 30.8%, 50.1%, 78.8%, respectively. The apoptosis index in treatment groups was higher than that in the control group (P<0.01), and the combination group was higher than single drug group (P<0.01). The expressions of PCNA, Bcl-2 in treatment groups were lower than those in the control group (P<0.01), and the combination group was lower than single drug group (P<0.05). The expression of caspase-3 in treatment groups was higher than that in the control group (P<0.05), and the combination group was higher than single drug group (P<0.01). Conclusion Both celecoxib and tegafur gimeracil oteracil potassium showed obvious anti-tumor effect, and the combination of the two acted synergistically. The possible mechanism was that they inhibited tumor growth through inhibiting proliferation and promoting apoptosis of the tumor cells.