Expression of Phospho-Akt and PTEN Proteins in Human Breast Cancer in Relation to Tumor Progression and Patient Survival

Phosphatidylinositol 3-kinase (PI3-kinase) controls mitogenesis, cellular growth and transformation in a variety of cancers. The serine-threonine kinase Akt is a downstream target of PI3-kinase, and phosphorylated Akt (Phospho-Akt) inhibits apoptosis. Phosphatase and tensin homolog detected on chromosome ten (PTEN) is a tumor suppressor that antagonizes PI3-kinase activity, negatively regulates its downstream-target, Akt, inhibits phosphorylation of Akt, and medicates cell-cycle arrest and apoptosis. To clarify whether the PI3-kinase/Akt pathway and PTEN relate to breast cancer, we examined the expression of pathway-related proteins such as Phospho-Akt and PTEN in clinical specimens. Immunohistochemical analysis was performed on tissue specimens surgically obtained from 221 patients with breast cancer. The association of Phospho-Akt and PTEN expression with clinicopathological variables and the prognosis of patients were analyzed. Of 221 breast carcinomas, positive Phospho-Akt expression was observed in 91 (41.1%) and positive PTEN expression in 119 (53.8%). Phospho-Akt expression and loss of PTEN expression significantly correlated with tumor staging, tumor size and lymph node metastasis. Patients with Phospho-Akt-positive tumors had significantly inferior disease-free survival or over-all survival to those with Phospho-Akt-negative tumors, while those with PTEN positive tumors were better than those with PTEN negative tumors. Moreover, patients with Phospho-Akt-positive and PTEN-negative tumors had a significantly inferior disease-free survival and over-all survival compared to those with Phospho-Akt-negative and PTEN-positive tumors. Multivariate analysis revealed that expression of Phospho-Akt and tumor size were the independent factors (P = 0.024). We demonstrated that the expression of Phospho-Akt significantly correlated with tumor progression and patients survival with breast cancer. Phospho-Akt/PTEN expression status is possibly a definitive prognostic factor in clinical breast cancer

Plasma Leptin Level, the Adipocyte-Specific Product of the Obese Gene, Is Associated with Tumor Progression and Is a Marker of the Nutritional Status of Patients with Gastric Cancer

Leptin, a product of the obese gene, is synthesized and released into the circulation in response to increased energy storage in adipose tissue. Leptin plays an important role in the regulation of body weight and energy balance. However, leptin levels in patients with malignant tumor have not been fully examined. The purpose of the present study is to clarify the clinical implications of leptin levels in the circulation in patients with gastric cancer. The subjects were 103 patients with gastric cancer at various stages. Levels of leptin in the plasma were determined with a commercially available human leptin-selective quantitative enzyme immunoassay kit. There were clear decreasing trends in leptin levels along with tumor progression in both males and females, and statistically significant differences were observed in males between stages II and IV, and in females between stages I and IV. Plasma leptin levels of females were consistently higher than those of males when we compared them with patients in the same stages. Moreover, statistically significant decreases in leptin levels were observed postoperatively. However, there were no statistically significant relationships between leptin levels and clinicopathological findings. There was a positive correlation between levels of plasma leptin and values of the body mass index. These findings may indicate that plasma leptin levels do not involve factors relevant to specific tumor growth but involve some tumor-related nutritional status due to tumor progression. We conclude that leptin levels are reflected during tumor-bearing status, and these are also useful markers for both indicating tumor progression and discovering the nutritional status of patients with gastric cancer

Immunohistochemical Detection of Occult Serosal Microinvasion in Primary Lesions of Gastric Cancer with Subserosal Invasion

In gastric cancer, the presence or absence of serosal invasion by cancer in the primary lesion is an important prognostic factor. Pathological findings are routinely determined by hematoxylin-eosin (H&E) staining, but it is well known that micrometastasis or microinvasion are easily overlooked by H&E staining. Cytokeratin (CK) proteins serve as reliable markers for cells from epithelial origins. The purpose of this study was to clarify the usefulness of CK immunohistochemical staining in the detection of serosal microinvasion in gastric cancer with subserosal invasion. We examined 50 primary lesions from 50 gastric cancer patients with subserosal invasion. Two consecutive sections were prepared for simultaneous staining with ordinary H&E and CK immunostaining with anticytokeratin antibody (CAM 5.2), respectively. Although there were no differences in the postoperative survival rates between patients with or without microinvasion, serosal microinvasion was 0detected in 8 (16%) of 50 patients by CK staining, including 1 patient whose invasion was detected by both H&E and CK stainings. CK immunostaining enabled us to make an accurate and detailed diagnosis which we believe to be useful for detecting serosal microinvasion in the primary lesion in gastric cancer with subserosal invasion

Clinical Findings on Fibroblast Activation Protein in Patients with Gastric Cancer

Human fibroblast activation protein (FAP) is a 97-kDa surface glycoprotein expressed in tumor-associated fibroblasts. In this study, we immunohistochemically examined FAP levels in surgically resected gastric carcinomas and explored their association with clini-copathological findings and prognosis. Sections of paraffin-embedded specimens were obtained from 100 patients with advanced gastric cancer between 1989 and 2001 at our institution, and they were stained with an anti-FAP antibody. Expression of FAP was detected in 64 patients (64%). Lymphatic vessel invasion was observed in 90% of FAP-positive patients (P = 0.015). Blood vessel invasion was observed in 98% of FAP-positive patients (P < 0.001). The disease-specific 5-year survival rate of in the 64 patients with FAP-positive tumors (22%) was significantly lower than in the 36 patients with FAP-negative tumors (34%, P = 0.036). This indicates that vessel invasion is connected with the expression of FAP and that a positive finding of FAP confer a worse prognosis in the patients with gastric cancer

Rho-ROCK Expression Predicts the Prognosis in Patients with T3/T4 Gastric Cancer

A small GTPase Rho protein and an effector ROCK have significant roles in cancer adhsion, metastasis, invasion, angiogenesis and cell mortality. We investigated the expressions of RhoA protein and ROCK-1 protein in 100 patients with macroscopically T3/T4 gastric cancer immunohistochemically. The expression of RhoA was detected in gastric cancer specimens from 39 patients and that of ROCK-1 in specimens from 30 patients. The clinicopathological characteristics of 21 tumors with co-expression of RhoA and ROCK-1 proteins (Rho/ROCK ON) were compared with those of the 79 remaining tumors (Rho/ROCK OFF). The percentage of lymph node metastasis positive cases in the Rho/ROCK ON group (81%) was higher than that in the Rho/ROCK OFF group (66%), but the difference was not significant (P = 0.183). However, the prognosis of the 21 patients with Rho/ROCK ON was significantly poorer than that of the 79 with Rho/ROCK OFF (P = 0.006). Our results indicate that the evaluation of the protein expression of RhoA and ROCK-1 is useful for predicting the prognosis in patients with T3/T4 gastric cancer

Cytokeratin-Positive Cells in Lymph Nodes in Which Metastases Are Undetectable by Conventional Histological Staining in Advanced Gastric Cancer

Detection of occult metastases in lymph nodes by immunostaining is becoming of increasing interest as a way to improve the accuracy of predicting the prognosis for patients with gastric cancer. Immunohistochemical detection of cytokeratin (CK) is recognized as the most sensitive method for identification of cancerous epithelial cells. In this study, lymph nodes were stained for CK in an effort to detect micrometastases and the clinical implications of the results were examined. We immunostained sections from a total of 1,198 lymph nodes from 25 totally gastrectomized patients with T3 or T4 gastric cancer who had been diagnosed as having no nodal involvement by conventional hematoxylin-eosin (HE) staining. Eighty (6.7%) of 1,198 lymph nodes from 15 (60%) of the 25 patients were immunostained with a CK-specific monoclonal antibody. CK-positive cells were more frequent in patients with macroscopic types of 3,4 and 5 gastric cancer. Patients with nodes that were both HE-negative and CK-negative had the best postoperative survival, followed by patients with HE-negative and CK-positive nodes and, finally, by patiof micrometastases in lymph nodes is a reliable indicator of the prognosis of patients with advanced gastric cancer

Laparoscopy-Assisted Pylorus-Preserving Gastrectomy for Treating Early Gastric Cancer

Laparoscopy-assisted pylorus-preserving gastrectomy (LAPPG) with lymphadenectomy has been used for treating early gastric cancer located in the middle-third of the stomach. However, firm evidence supporting its safety and usefulness is scant. This study examined 24 and 10 gastric adenocarcinoma patients who had undergone conventional pylorus-preserving gastrectomy (CPPG) and LAPPG, respectively, at our institution. Operation time for LAPPG (362.8 ± 49.6 min) was significantly longer than that for CPPG (221.9 ± 50.0 min; P = 0.04). Estimated blood loss with LAPPG (127.5 ± 91.2 mL) was not significantly different from that with CPPG (167.9 ± 149.9 mL; P = 0.44). Total number of resected lymph nodes was 26.3 ± 9.5 and 21.3 ± 10.8 with LAPPG and CPPG, respectively, with no statistically significant difference. C-reactive protein in serum on postoperative day 1 was significantly lower in the LAPPG than in the CPPG group (5.3 ± 1.7 mg/dL versus 7.8 ± 3.6 mg/dL; P = 0.049). The requirement for analgesia after surgery was more frequent in the CPPG than in the LAPPG group (3.7 ± 2.0 versus 2.2 ± 1.7; P = 0.04). Time to first flatus was shorter in the LAPPG than in the CPPG group (1.9 ± 0.9 days versus 3.1 ± 0.9 days; P = 0.0006). Postoperative hospital stay was significantly shorter in the LAPPG than in the CPPG group (12.0 ± 4.0 days versus 23.0 ± 10.7days; P = 0.0036). With regard to postoperative complications, stasis was observed more frequently in the CPPG (33.3%) than in the LAPPG (10%) group. In conclusion, patients treated by LAPPG showed a comparable quality of surgical operation compared with those treated by CPPG

The PI3K-Akt Pathway in SN-38-Induced Apoptosis in Human Gastric Cancer Cell Lines

SN-38, an active metabolite of a topoisomerase I inhibitor, CPT-11, exhibits a cytotoxic effect by inducing apoptosis in cancer cells. Phosphatidylinositol-3-OH kinase (PI3K)-Akt signaling is known to protect a variety of cells from apoptosis. The relationship between resistance to SN-38-induced apoptosis and the PI3K-Akt pathway in human gastric cancer cells is unknown. Here, we did an investigation using two gastric cancer cell lines, MKN1 and MKN45. Cell viability was determined by sodium 3'-[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis(4-methoxy-6-nitro) benzene sulfonic acid hydrate (XTT) assay. Apoptosis was confirmed by fluorescence microscopy using Hoechst 33342 staining. Expression levels of phospho-Akt (pAkt) were determined by Western blotting. After being treated with SN-38, the populations of sub-G1 cells were induced by flow cytometry in 36.8% of MKN45 cells more frequently than in 13.5% of MKN1 cells. SN-38 inhibited the expression of pAkt dose-dependently in MKN45 cells, but not in MKN1 cells. In MKN1 cells, an additional pretreatment with the PI3K inhibitor, LY294002, led to the inhibition of pAkt expression and induced apoptosis. The results suggested that SN-38 induces apoptosis by decreasing PI3K-Akt survival signaling, the anti-apoptotic signals, in human gastric cancer cells. Akt inhibitor might be a useful anti-tumor agent in combination with CPT-11

Gastric cancer treatment in Japan: 2008 annual report of the JGCA nationwide registry

The Japanese Gastric Cancer Association (JGCA) started a new nationwide gastric cancer registry in 2008. Approximately 50 data items, including surgical procedures, pathological diagnoses, and survival outcomes, for 12004 patients with primary gastric cancer treated in 2001 were collected retrospectively from 187 participating hospitals. Data were entered into the JGCA database according to the JGCA Classification of gastric carcinoma, 13th edition and the International Union Against Cancer (UICC) TNM Classification of malignant tumors, 5th edition by using an electronic data collecting system. Finally, data of 11261 patients with gastric resection were analyzed. The 5-year follow-up rate was 83.5%. The direct death rate was 0.6%. TNM 5-year survival rates (5YSRs)/JGCA 5YSRs were 91.8/91.9% for stage IA, 84.6/85.1% for stage IB, 70.5/73.1% for stage II, 46.6/51.0% for stage IIIA, 29.9/33.4% for stage IIIB, and 16.6/15.8% for stage IV. The proportion of patients more than 80 years old was 7.0%, and their 5YSR was 48.7%. Compared to the JGCA archived data, though the follow-up rate needs to be improved, these data suggest that the postoperative results of patients with primary gastric carcinoma have improved in those with advanced disease and in the aged population in Japan

Inhibitory effects of local anesthetics on the proteasome and their biological actions

Local anesthetics (LAs) inhibit endoplasmic reticulum-associated protein degradation, however the mechanisms remain elusive. Here, we show that the clinically used LAs pilsicainide and lidocaine bind directly to the 20S proteasome and inhibit its activity. Molecular dynamic calculation indicated that these LAs were bound to the β5 subunit of the 20S proteasome, and not to the other active subunits, β1 and β2. Consistently, pilsicainide inhibited only chymotrypsin-like activity, whereas it did not inhibit the caspase-like and trypsin-like activities. In addition, we confirmed that the aromatic ring of these LAs was critical for inhibiting the proteasome. These LAs stabilized p53 and suppressed proliferation of p53-positive but not of p53-negative cancer cells