Keishiro Aoyagi

Expression of CD133 in the cytoplasm is associated with cancer progression and poor prognosis in gastric cancer

BackgroundCD133 is one of the most important stem cell markers in solid cancers. Some recent reports have described a possible relationship between CD133 and hypoxia-inducing factor-1-alpha (HIF-1α). The aim of this study was to clarify the clinical role of CD133 expression in gastric cancer and to investigate the correlation between CD133 expression and HIF-1α expression.MethodsWe studied 189 gastric cancer patients who underwent gastrectomy at Kurume University Hospital. CD133 and HIF-1α expression was examined using immunohistochemical staining. Fifty-six cases were CD133 positive, and they were divided into two expression types: luminal expression of the gland and cytoplasmic expression. We investigated the relationship among CD133 expression types, clinicopathological variables, prognosis, and HIF-1α expression.ResultsWhen comparing clinicopathological variables, expression of CD133 in the cytoplasm was related to metastasis and tumor progression. However, this relationship was not observed with luminal expression of the gland type. The survival rate in patients with cytoplasmic CD133 expression was significantly worse than that in the CD133-negative group. This relationship was observed in the survival rate of the adjuvant chemotherapy group and the curative resection group. Multivariate analysis revealed that the expression of CD133 in the cytoplasm was an independent prognostic factor in gastric cancer. Regarding the correlation between CD133 expression and HIF-1α expression, the HIF-1α positive rate was lower in patients with CD133 luminal expression of the gland type and higher in patients with cytoplasmic expression of CD133.ConclusionGastric cancer cells with CD133 expression in the cytoplasm were cells with high potential for malignancy, and this phenotype was associated with cancer progression, chemotherapy resistance, recurrence, and poor prognosis. Cytoplasmic expression of CD133 may be a useful prognostic marker in gastric cancer. Significant correlation was observed between HIF-1α expression and the immunohistochemical staining pattern of CD133.

VEGF significance in peritoneal recurrence from gastric cancer

BackgroundIn gastric cancer, the management of peritoneal dissemination in the Peritoneal cavity is extremely important; however, peritoneal dissemination in the final stage of gastric cancer remains untreatable. Peritoneal dissemination involves several steps, including tumor-cell attachment, invasion, and growth in the peritoneum. Many cytokines, growth factors, matrix metalloproteinases (MMPs), and angiogenic factors play important roles in these steps. So far, few studies have investigated the correlation, if any, between peritoneal dissemination and the angiogenic factor, vascular endothelial growth factor (VEGF).MethodsImmunohistochemical staining, using the avidin-biotin peroxidase complex method, was performed on slides of surgical specimens from 40 patients with stage II gastric cancer with serosal invasion, who underwent surgery at our hospital between 1990 and 2000. Anti-human VEGF rabbit polyclonal IgG was used as the primary antibody. VEGF expression was classified in one of four categories depending on the percentage of tumor-cell staining (P). VEGF expression was also classified in one of three categories depending on the staining intensity (I). The VEGF expression score was calculated as P × I.ResultsThere were ten patients with peritoneal recurrence. Of these, seven had macroscopic type-4 scirrhous-type gastric carcinoma. In the immunohistochemical study, the VEGF score of patients with peritoneal recurrence was 9.40 ± 2.46; on the other hand, that of patients without peritoneal recurrence was 3.47 ± 2.36. The VEGF score of patients with peritoneal recurrence was significantly higher than that of patients without peritoneal recurrence. In patients with macroscopic type 4, the VEGF score of those with peritoneal recurrence was 9.14 ± 2.19, while on the other hand, that of the patients without peritoneal recurrence was 3.80 ± 3.03. The VEGF score of these patients with peritoneal recurrence was significantly higher than that of those without peritoneal recurrence. The survival rate in the VEGF low-expression group was significantly higher than that in the VEGF high-expression group. Multivariate analysis showed that the VEGF score was a significant parameter of peritoneal recurrence.ConclusionThese results suggested that VEGF was correlated with peritoneal metastasis from gastric cancer, and that VEGF was a useful indicator of peritoneal recurrence.

Clinicopathological significance of hypoxia-inducible factor-1 alpha (HIF-1α) expression in gastric cancer.

BackgroundHypoxia is a common feature of rapidly growing solid tumors. Therefore, cellular adaptation to hypoxia and altered glucose metabolism are fundamental to the biology of cancer cells. Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor for more than 60 genes recognized to control the delivery of oxygen and nutrients through the induction of angiogenesis and glycolysis under hypoxic conditions. Therefore, inhibition of the expression of HIF-1α can be expected to be potentially tumor-specific molecular target-based therapy. In this study, we evaluated the significance of HIF-1α expression in relationship to clinicopathological factors, prognosis, vascular endothelial growth factor (VEGF) expression, and microvessel density (MVD).MethodsParaffin-embedded tumor specimens from 128 patients who underwent gastrectomy at Kurume University from 2004 to 2005 were used to assess the clinical significance of HIF-1α expression. We used the ABC method to perform an immunohistochemical analysis of the HIF-1α and VEGF expression.ResultsEighty-four (65.6%) of gastric cancer specimens were positive for HIF-1α expression. Multivariate analysis showed that histology, depth of invasion, VEGF expression, and MVD were significantly associated with HIF-1α expression. On relapse-free and overall survival curves, the HIF-1α-negative group was significantly higher than the HIF-1α-positive group. Moreover, HIF-1α(+)/VEGF(+) patients had the worst prognosis. HIF-1α expression was identified as a significant predictor of relapse-free survival and overall survival by multivariate Cox’s proportional hazard analyses.ConclusionOverexpression of HIF-1α was found to be an indicator of poor prognosis for patients with gastric cancer and was significantly correlated with histology, depth of invasion, VEGF, and MVD.

Characteristics and prognosis of gastric cancer in young patients

The clinicopathological features of gastric cancer (GC) differ between younger and older patients, and it is thought that younger patients have a worse prognosis than older patients due to delayed diagnosis and more aggressive tumor behavior. These characteristics, however, remain controversial. A total of 3,818 patients with pathologically confirmed primary gastric adenocarcinoma were treated at our institution. We analyzed the difference in demographic and clinicopathological characteristics between 169 young [≤40 years of age, younger group (YG)] and 3,649 older [>40 years of age, older group (OG)] GC patients. There was a significantly higher proportion of females in the YG compared with the OG (53.3 and 31.0%, respectively; P<0.0001). The 5-year overall survival of the YG was significantly lower compared to that of the OG (59.7 and 65.9%, respectively; P=0.049). However, YG patients with curative resection had a similar 5-year survival rate to OG patients with curative resection (88.0 and 85.8%, respectively; P=0.547). Female patients in the YG showed a significantly lower survival rate than males in the YG (44.3 and 73.1%, respectively; P=0.0002). Multivariate analyses revealed that macroscopic type, depth of invasion, peritoneal metastasis, distant metastasis and curative resection were independent prognostic factors for the YG with GC. Young GC patients who undergo curative resection do not have a worse prognosis than older patients. Early diagnosis is important in successfully carrying out a curative resection and offering a better prognosis, particularly in females.

Prognosis of metastatic splenic hilum lymph node in patients with gastric cancer after total gastrectomy and splenectomy.

AIM To clarify the significance of combined resection of the spleen to dissect the No. 10 lymph node (LN). METHODS We studied 191 patients who had undergone total gastrectomy with splenectomy, excluding non-curative cases, resection of multiple gastric cancer, and those with remnant stomach cancer. Various clinicopathological factors were evaluated for any independent contributions to No. 10 LN metastasis, using χ(2) test. Significant factors were extracted for further analysis, carried out using a logistic regression method. Furthermore, lymph node metastasis was evaluated for any independent contribution to No. 10 LN metastasis, using the same methods. The cumulative survival rate was calculated using the Kaplan-Meier method. The significance of any difference between the survival curves was determined using the Cox-Mantel test, and any difference was considered significant at the 5% level. RESULTS From the variables considered to be potentially associated with No. 10 LN metastasis, age, depth, invasion of lymph vessel, N factor, the number of lymph node metastasis, Stage, the number of sites, and location were found to differ significantly between those with metastasis (the Positive Group) and those without (the Negative Group). A logistic regression analysis showed that the localization and Stage were significant parameters for No. 10 LN metastasis. There was no case located on the lesser curvature in the Positive Group. The numbers of No. 2, No. 3, No. 4sa, No. 4sb, No. 4d, No. 7, and No. 11 LN metastasis were each found to differ significantly between the Positive Group and the Negative Group. A logistic regression analysis showed that No. 4sa, No. 4sb, and No. 11 LN metastasis were each a significant parameter for No. 10 LN metastasis. There was no significant difference in survival curves between the Positive Group and the Negative Group. CONCLUSION Splenectomy should be performed to dissect No. 10 LN for cases which have No. 4sa, No. 4sb or No. 11 LN metastasis. However, in cases where the tumor is located on the lesser curvature, splenectomy can be omitted.

Suppressive effect of bevacizumab on peritoneal dissemination from gastric cancer in a peritoneal metastasis model

PurposeVascular endothelial growth factor (VEGF) has been reported to enhance vascular permeability and angiogenesis in the abdominal wall, thereby contributing to peritoneal dissemination with malignant ascites. We conducted this experimental study to find out if bevacizumab, a humanized monoclonal antibody against VEGF, had a suppressive effect on peritoneal dissemination from gastric cancer, in an experimental nude mouse model of peritoneal metastasis.MethodsEach mouse was treated with a single intraperitoneal (i.p.) injection of bevacizumab. Five mice were killed, and we measured their body weight, the mean number of tumor nodules, and the volume of ascites. We also extracted retroperitoneal tissues for histological examination, to count the frequency of mitosis, and to calculate the mitotic index. Another five mice were monitored until death, and their mean survival duration was calculated.ResultsThe volume of ascites and the mitotic index were significantly lower in the therapy group than in the nontherapy group (P = 0.042 and P < 0.01, respectively). The survival curve of the therapy group was significantly higher than that of the nontherapy group (P = 0.005).ConclusionBevacizumab may suppress peritoneal dissemination from gastric cancer.

The TIMP-1 gene transferred through adenovirus mediation shows a suppressive effect on peritoneal metastases from gastric cancer

BackgroundIt has become clear in recent years that peritoneal metastasis takes place as the result of a multistep process involving attachment, invasion, proliferation, and angiogenesis. The aim of the present study was to evaluate the suppressive effect of tissue inhibitor of metalloproteinase-1 (TIMP-1) gene transfer on peritoneal dissemination.MethodsWe established a high-potential peritoneal metastasis cell line (MKN-45P), using the gastric cancer cell line MKN-45, and developed a peritoneal metastasis model in nude mice. The TIMP-1 gene was transferred to MKN-45 or MKN-45P by adenoviral transfection, and we performed an in vitro invasion assay and an in vivo study, using the peritoneal metastasis model. The TIMP-1 transfected group was compared with a non-virus group and a Lac-Z transfected group.ResultsThe in vitro invasion assay showed that the number of invasive cells was significantly reduced in the TIMP-1 transfected group compared with that in the non-virus group and the Lac-Z transfected group, Moreover, the in vivo studies showed that the number and the weight of the peritoneal nodes in the TIMP-1 transfected group were significantly less than those in the Lac-Z transfected group, and less than those in the non-viral group. No bloody ascites was recognized in the TIMP-1 transfected group. The mean number of tumor vessels in the non-virus group and the Lac-Z group was significantly higher than that in the TIMP-1 group. ConclusionTIMP-1 demonstrated an inhibitory effect on angiogenesis, and may be worthwhile investigating for use as a future therapy for peritoneal dissemination.

Molecular targeting to treat gastric cancer

Trastuzumab that targets human epidermal growth factor receptor 2 (HER2) protein is the only approved molecular targeting agent for treating gastric cancer in Japan and the outcomes have been favorable. However, trastuzumab is effective for only 10% to 20% of the population with gastric cancer that expresses HER2 protein. Molecular targeting therapy with bevacizumab against vascular endothelial growth factors (VEGF) and with cetuximab and panitumumab against the epidermal growth factors pathway that have been approved for treating colorectal cancer are not considered effective for treating gastric cancer according to several clinical trials. However, ramucirumab that targets VEGF receptor-2 prolonged overall survival in a large phase III clinical trial and it might be an effective molecular targeting therapy for gastric cancer. The significance of molecular targeting therapy for gastric cancer remains controversial. A large-scale randomized clinical trial of novel molecular targeting agents with which to treat gastric cancer is needed.

Molecular targeting therapy using bevacizumab for peritoneal metastasis from gastric cancer

AIM To clarify the significance of vascular endothelial growth factor (VEGF) in peritoneal metastasis from gastric cancer, using the gastric cancer cell line MKN-45 compared with the high potential peritoneal dissemination gastric cancer cell line MKN-45P. METHODS The supernatant of culture medium of MKN-45 cells or MKN-45P cells was collected and the concentrations were measured of various cytokines, matrix metalloproteinases, growth factor and angiogenic factors, including VEGF. We performed an initial pilot study to explore whether bevacizumab, a humanized monoclonal antibody against VEGF, had any suppressive effect on the peritoneal dissemination from gastric cancer in an experimental nude mouse model of peritoneal metastasis. RESULTS The concentrations of interleukin-6 (IL-6), IL-8, VEGF and matrix metalloproteinase-2 protein in the culture supernatant were each significantly higher than each of those for MKN-45. In the in vivo study, the volume of ascites and the mitotic index were significantly lower in the therapy group than in the non-therapy group. The survival curve of the therapy group was significantly higher than that of the non-therapy group. These results suggested that VEGF was correlated with peritoneal metastasis from gastric cancer. CONCLUSION Findings suggested that bevacizumab for inhibiting VEGF could suppress peritoneal dissemination from gastric cancer.

Cronkhite-Canada syndrome complicated with multiple gastric cancers and multiple colon adenomas

Background: We experienced a case in which Cronkhite-Canada Syndrome presented with complications of multiple gastric cancers and multiple colon adenomas. Case Report: Our case is a 64-year-old male who visited a nearby hospital with diarrhea and weight loss. The patient was anemic and hypoproteinemic, with multiple polyps in the stomach, duodenum, and large intestine. He also presented with alopecia, onychatrophia, cutaneous pigmentation, and dysgeusia, and was diagnosed with Cronkhite-Canada Syndrome. Follow-up examinations found multiple gastric cancers and colon adenomas. We performed a total gastrectomy and a polypectomy of the large intestine lesions, revealing 4 well-differentiated adenocarcinomas in the resected stomach, and tubular adenomas in the large intestine lesions. Intraoperative findings included scattered melanoid pigmentation on the mesentery and the small intestinal wall. Tumor cells were positive for p53 and Ki67 and partially positive for MUC5AC and MUC2. Cronkhite-Canada Syndrome polyps are generally classified as juvenile type polyps, and these polyps rarely become cancerous. However, of the 383 cases of Cronkhite-Canada Syndrome reported in Japan, complications of gastric cancer were found in 39 cases (10.2%), and only 8 cases with multiple gastric cancer were reported in Japan. including the cases we have personally experienced. There were only two English literatures on Cronkhite-Canada Syndrome complicated with gastric cancer. So it is necessary to notify this information of Cronkhite-Canada Syndrome to the world. Conclusions: Close gastrointestinal examination and strict follow-up are believed to be essential for Cronkhite-Canada Syndrome patients.