Satoru Noda

Significance of E-cadherin expression in triple-negative breast cancer

Purpose:Triple-negative breast cancer (TNBC), a subtype of breast cancer that is oestrogen receptor (ER) negative, progesterone receptor (PR) negative, and human epidermal growth factor receptor 2 (HER2) negative, has a poor prognosis. Although a correlation between E-cadherin expression level and outcome has been demonstrated among all types of breast cancer, little is known about the significance of E-cadherin expression levels in TNBC.Methods:A total of 574 patients who had undergone a resection of a primary breast cancer except for invasive lobular carcinomas were enrolled in this study. Expressions of ER, PR, HER2, and E-cadherin were assessed by immunohistochemistry. We examined the association between TNBC and other clinicopathological variables and evaluated the significance of the E-cadherin expression.Results:Among the 574 breast cancer cases, 123 (21.4%) revealed a triple-negative phenotype. Patients with TNBC experienced more frequent lymph node metastasis (P=0.024) and a poorer prognosis (P<0.001) in comparison with non-TNBC patients. Triple-negative breast cancer was an independent prognostic factor. Reduced levels of E-cadherin were observed in 238 (41.5%) of the 574 breast cancer cases. E-cadherin reduction was significantly frequent in cases of TNBC (P<0.001) and lymph node metastasis (P=0.032). Furthermore, in the 123 TNBC cases, the prognosis of patients with an E-cadherin-negative expression was significantly worse than that of E-cadherin-positive patients (P=0.0265), especially for those in clinical stage II (P=0.002). A multivariate logistic regression analysis showed a reduction of the E-cadherin expression to be an independent prognostic factor (P=0.046).Conclusion:E-cadherin expression may be a useful prognostic marker for classifying subgroups of TNBC.

Hypoxia Stimulates the EMT of Gastric Cancer Cells through Autocrine TGFβ Signaling

Epithelial mesenchymal transition (EMT) is considered to be correlated with malignancy of cancer cells and responsible for cancer invasion and metastasis. We previously reported that distant metastasis was associated with hypoxia in gastric cancer. We therefore investigated the effect of hypoxic condition on EMT of gastric cancer cells. Gastric cancer cells were cultured in normoxia (21% O2) or hypoxia (1% O2) for 24 h. EMT was evaluated as the percentage of spindle-shaped cells in total cells. Effect of transforming growth factor β1 (TGFβ1) or tyrosine kinase inhibitors on the EMT was evaluated. The expression level of TGFβ1 and TGFβR was evaluated by real time RT-PCR. The TGFβ1 production from cancer cells was measured by ELISA. Hypoxia stimulated EMT of OCUM-2MD3 and OCUM-12 cells, but not that of OCUM-2M cells. The expression level of TGFβ1 mRNA under hypoxia was significantly higher than that under normoxia in all of three cell lines. The expression level of TGFβR mRNA was significantly increased by hypoxia in OCUM-2MD3 cells, but not in OCUM-2M cells. TGFβR inhibitor, SB431542 or Ki26894, significantly suppressed EMT of OCUM-2MD3 and OCUM-12. TGFβ1 production from OCUM-2MD3 and OCUM-12 cells was significantly increased under hypoxia in comparison with that under normoxia. These findings might suggest that hypoxia stimulates the EMT of gastric cancer cells via autocrine TGFβ/TGFβR signaling.

Upregulation of cancer-associated myofibroblasts by TGF-β from scirrhous gastric carcinoma cells.

Background:Myofibroblasts in the cancer microenvironment have recently been implicated in tumour growth and metastasis of gastric cancer. However, the mechanisms responsible for the regulation of myofibroblasts in cancer-associated fibroblasts (CAFs) remain unclear. This study was performed to clarify the mechanisms for regulation of myofibroblasts in gastric cancer microenvironment.Methods:Two CAFs (CaF-29 and CaF-33) from the tumoural gastric wall and a normal fibroblast (NF-29) from the nontumoural gastric wall, 4 human gastric cancer cell lines from scirrhous gastric cancer (OCUM-2MD3 and OCUM-12), and non-scirrhous gastric cancer (MKN-45 and MKN-74) were used. Immunofluorescence microscopy by triple-immunofluorescence labelling (α-SMA, vimentin, and DAPI) was performed to determine the presence of α-SMA-positive myofibroblasts. Real-time RT–PCR was performed to examine α-SMA mRNA expression.Results:Immunofluorescence microscopy showed that the frequency of myofibroblasts in CaF-29 was greater than that in NF-29. The number of myofibroblasts in gastric fibroblasts gradually decreased with serial passages. Transforming growth factor-β (TGF-β) significantly increased the α-SMA expression level of CAFs. Conditioned medium from OCUM-2MD3 or OCUM-12 cells upregulated the α-SMA expression level of CAFs, but that from MKN-45 or MKN-74 cells did not. The α-SMA upregulation effect of conditioned medium from OCUM-2MD3 or OCUM-12 cells was significantly decreased by an anti-TGF-β antibody or Smad2 siRNA.Conclusion:Transforming growth factor-β from scirrhous gastric carcinoma cells upregulates the number of myofibroblasts in CAFs.

Establishment and characterization of a new hypoxia-resistant cancer cell line, OCUM-12/Hypo, derived from a scirrhous gastric carcinoma

Background:Many kinds of solid tumour have heterogeneously a hypoxic environment. Tumour hypoxia reported to be associated with more aggressive tumour phenotypes such as high metastatic ability and resistance to various anti-cancer therapies which may lead to a poorer prognosis. However, the mechanisms by which hypoxia affects the aggressive phenotypes remain unclear.Methods:We established a scirrhous gastric carcinoma cell line (OCUM-12) from ascites associated with scirrhous gastric carcinoma, and a hypoxia-resistant cancer cell line (OCUM-12/Hypo) was cloned from OCUM-12 cells by continuous exposure to 1% oxygen.Results:Histologic findings from orthotopic tumours derived from parent OCUM-12 cells and daughter OCUM-12/Hypo cells revealed poorly differentiated adenocarcinoma with extensive fibrosis that resembled human scirrhous gastric cancer. Necrotic lesions were frequently detected in the OCUM-12 tumours but were rarely found in the OCUM-12/Hypo tumours, although both types had multiple hypoxic loci. Apoptosis rate of OCUM-12 cells was increased to 24.7% at 1% O2, whereas that of OCUM-12/Hypo was 5.6%. The OCUM-12/Hypo orthotopic models developed multiple metastases to the peritoneum and lymph nodes, but the OCUM-12 models did not. OCUM-12/Hypo cells showed epithelial-to-mesenchymal transition and high migratory and invasive activities in comparison with OCUM-12 cells. The mRNA expression levels of both E-cadherin and zonula occludens ZO-1 and ZO-2 decreased in OCUM-12/Hypo cells, and that of vimentin, Snail-1, Slug/Snail-2, Twist, ZEB-1, ZEB-2, matrix metalloproteinase-1 (MMP-1), and MMP-2 were increased in OCUM-12/Hypo cells.Conclusion:OCUM-12 and OCUM-12/Hypo may be useful for the elucidation of disease progression associated with scirrhous gastric cancer in the setting of chronic hypoxia.

Cancer-associated orthotopic myofibroblasts stimulates the motility of gastric carcinoma cells

Tumor progression has been recognized as the product of evolving crosstalk between cancer cells and the surrounding stromal cells. Cancer‐associated orthotopic myofibroblasts may be linked to the progression of gastric carcinomas. To understand the significance of orthotopic myofibroblasts, we examined the effects of cancer‐associated orthotopic myofibroblasts on the malignant phenotype of gastric cancer cells. Three human gastric cancer cell lines (OCUM‐2MD3, OCUM‐12, MKN‐45) and four human gastric fibroblast cell lines (cancer‐associated orthotopic fibroblast [CaF]‐29, CaF‐33, normal orthotopic fibroblast [NF]‐29, NF‐33) were used. The cancer‐associated orthotopic fibroblast cell lines CaF‐29 and CaF‐33 were established from a tumoral gastric wall, and normal orthotopic fibroblast NF‐29 and NF‐33 were established from a non‐tumoral gastric wall. Fibroblasts that were α‐smooth muscle actin‐positive were defined as myofibroblasts. We examined the effects of cancer‐associated orthotopic myofibroblasts on the aggressiveness of gastric cancer cells by wound‐healing assay, invasion assay, and RT‐PCR. The ratios of myofibroblasts in CaF‐29 (33%) and CaF‐33 (46%) were significantly (P < 0.001) greater than those in NF‐29 (11%) or NF‐33 (13%). Although all four orthotopic fibroblast lines increased the motility of gastric cancer cells, including migration and invasion ability, the motility‐stimulating activity of cancer‐associated fibroblasts (CaF‐29 and CaF‐33) was significantly higher than that of normal fibroblasts (NF‐29 and NF‐33). These motility‐stimulating activities of cancer‐associated orthotopic fibroblasts were downregulated by Smad2 siRNA treatment and anti‐transforming growth factor‐β neutralizing antibody. These findings suggest that cancer‐associated orthotopic myofibroblasts may play an important role in the progression of gastric cancers and that transforming growth factor‐β produced by myofibroblasts may be one of the factors associated with the aggressiveness of gastric carcinoma cells. (Cancer Sci 2012; 103: 797–805)

Tumour-infiltrating CD8 to FOXP3 lymphocyte ratio in predicting treatment responses to neoadjuvant chemotherapy of aggressive breast cancer

Tumour‐infiltrating lymphocytes (TILs) can be used to monitor the immune response, and are important in predicting treatment responses and outcomes for various types of cancer. Recently, specific TIL subsets have been reported to be clinically useful in predicting treatment responses. The CD8+/FOXP3+ TIL ratio (CFR) may be a more sensitive indicator for monitoring immune function. This study investigated the clinical significance and value of CFR as a biomarker to predict treatment responses to neoadjuvant chemotherapy for breast cancer.

Phosphorylated Smad2 in Advanced Stage Gastric Carcinoma

BackgroundTransforming growth factor β (TGFβ) receptor signaling is closely associated with the invasion ability of gastric cancer cells. Although Smad signal is a critical integrator of TGFβ receptor signaling transduction systems, not much is known about the role of Smad2 expression in gastric carcinoma. The aim of the current study is to clarify the role of phosphorylated Smad2 (p-Smad2) in gastric adenocarcinomas at advanced stages.MethodsImmunohistochemical staining with anti-p-Smad2 was performed on paraffin-embedded specimens from 135 patients with advanced gastric adenocarcinomas. We also evaluated the relationship between the expression levels of p-Smad2 and clinicopathologic characteristics of patients with gastric adenocarcinomas.ResultsThe p-Smad2 expression level was high in 63 (47%) of 135 gastric carcinomas. The p-Smad2 expression level was significantly higher in diffuse type carcinoma (p = 0.007), tumours with peritoneal metastasis (p = 0.017), and tumours with lymph node metastasis (p = 0.047). The prognosis for p-Smad2-high patients was significantly (p = 0.035, log-rank) poorer than that of p-Smad2-low patients, while a multivariate analysis revealed that p-Smad2 expression was not an independence prognostic factor.ConclusionThe expression of p-Smad2 is associated with malignant phenotype and poor prognosis in patients with advanced gastric carcinoma.

VEGF-A/VEGFR-2 Signaling Plays an Important Role for the Motility of Pancreas Cancer Cells

BackgroundPancreatic cancer is one of the most lethal solid tumors. Vascular endothelial growth factor receptors (VEGFRs) are expressed not only by endothelial cells but also by pancreatic cancer cells. VEGFRs might play an important role for the development of pancreatic cancer cells. The purpose of this study was to evaluate the efficacy of VEGF/VEGFR-2—targeted therapy in pancreatic carcinoma.MethodsFive pancreatic carcinoma cell lines were used. The expression level of VEGFR-2 of cancer cells was examined by RT-PCR and Western blot. The effects of VEGFs, bevacizumab as an anti-VEGF antibody, sunitinib as a tyrosine kinase inhibitor against VEGFRs, and VEGF-R2 siRNA on the motility activity of pancreatic cancer cells were examined by invasion assay and wound healing assay. The effect of VEGF, bevacizumab, and sunitinib on the phosphorylation of VEGFR-2 and downstream effecter molecules, MAPK and PI3K, was examined by western blot.ResultsPancreatic cancer cell lines expressed VEGFR-2. VEGF-A significantly increased the motility of pancreas cancer cells, which was inhibited by VEGFR-2 siRNA. Conditioned medium from pancreas cancer cells significantly stimulated the motility of pancreas cancer cells. VEGF/VEGFR inhibitors, bevacizumab and sunitinib, significantly decreased the motility of pancreas cancer cells. VEGFR-2 phosphorylation level of pancreas cancer cells was increased by VEGF-A. Bevacizumab and sunitinib decreased the level of VEGFR-2 phosphorylation, p-ERK, and p-Akt expression. VEGF-A decreased zonula occludens (ZO-1) or ZO-2 expression in pancreas cancer cells.ConclusionsVEGF-A/VEGFR-2 signaling plays an important role in inducing invasion and migration of pancreatic cancer cells.

Use of Tumor-infiltrating lymphocytes (TILs) to predict the treatment response to eribulin chemotherapy in breast cancer

Background Eribulin mesylate (eribulin) is currently indicated for treatment of locally advanced or metastatic breast cancer (MBC). It is a cytotoxic agent with unique mechanisms that suppress epithelial-mesenchymal transition (EMT) of cancer cells. On the other hand, Tumor-infiltrating lymphocytes (TILs), which are considered indicators of immune response monitoring, have been reported as prognostic factors and predictors of therapeutic efficacy. We thought that eribulin, which has an EMT-inhibiting mechanism, may produce an antitumor effect by improving the immune microenvironment, and in this study investigated the effects of breast cancer eribulin chemotherapy on the immune microenvironment with TILs as a marker. Methods TILs was evaluated in 52 patients with MBC who underwent chemotherapy with eribulin. The correlation between TILs evaluated according to the standard method, and prognosis, including the efficacy of eribulin chemotherapy, was investigated retrospectively. Results Of the 52 MBC patients, 29 (55.8%) were in the high TILs group and 23 (44.2%) were in the low TILs group. The high TILs group included significantly more triple-negative breast cancer (TNBC) (p = 0.008) than the low TILs group. In an analysis of outcomes, TNBC patients in the high TILs group had significantly longer disease-free survival than TNBC patients in the low TILs group (p = 0.033, log-rank), but no significant differences were seen in all breast cancer patients (p = 0.489, log-rank) or in non-TNBC patients (p = 0.878, log-rank). In a multivariate analysis of recurrence in TNBC patients, being in the high TILs group was again an independent factor for a good outcome (p = 0.031, HR = 0.063). Conclusion The results of this study suggest that TILs may be useful as a predictive marker of the therapeutic effect of eribulin chemotherapy in TNBC.

Clinical verification of sensitivity to preoperative chemotherapy in cases of androgen receptor-expressing positive breast cancer.

Background:Triple-negative breast cancer (TNBC) patients testing positive for androgen receptor (AR) expression are thought to be chemotherapy resistant, similar to other hormone receptor-positive breast cancers; however, this has not been substantially validated in the clinic. In this study, we investigated the association between chemotherapy sensitivity and AR expression in patients treated with neoadjuvant chemotherapy (NAC) using standardised chemotherapy criteria and regimens.Methods:A total of 177 patients with resectable early-stage breast cancer were treated with NAC. Oestrogen receptor, progesterone receptor, HER2, Ki67 and AR status were assessed immunohistochemically.Results:Sixty-one patients were diagnosed with TNBC; AR expression was identified in 23 (37.7%), which was significantly less common than that found in non-TNBC patients (103 of 116; 88.8%; P<0.001). The rate of pathological complete response after NAC was significantly lower (P=0.001), and disease recurrence was more common (P=0.008) in patients with AR-positive compared with those with AR-negative TNBC. In TNBC cases, as expected, the non-recurrence period in cases that were negative for AR expression was significantly extended (P=0.006, log-rank).Conclusions:Androgen receptor expressions may be useful as biomarkers to predict treatment responses to NAC in TNBC. Moreover, induction of a change in subtype to the AR-negative phenotype was observed after NAC.