IL-11 contribution to tumorigenesis in an NRF2 addiction cancer model.

The interaction between cancer cells and their microenvironment is an important determinant of the pathological nature of cancers, particularly their tumorigenic abilities. The KEAP1-NRF2 system, originally identified as a critical defense mechanism against oxidative stress, is often dysregulated in various human cancers forming solid tumors, resulting in the aberrant activation of NRF2. Increased accumulation of NRF2 in cancers is strongly associated with the poor prognoses of cancer patients, including those with lung and breast cancers. Multiple lines of evidence suggest that aberrantly activated NRF2 in cancer cells drives their malignant progression and that the cancer cells consequently develop 'NRF2 addiction.' Although the downstream effectors of NRF2 that are responsible for cancer malignancy have been extensively studied, mechanisms of how NRF2 activation contributes to the aggressive tumorigenesis remains to be elucidated. In this study, we found a significant correlation between NRF2 and IL-11 status in breast cancer patients. Based on a recent report demonstrating that IL-11 is induced downstream of NRF2, we examined the significance of IL-11 in NRF2-driven tumorigenesis with a newly established NRF2 addiction cancer model. Expression of Il11 was elevated during the tumorigenesis of the NRF2 addiction cancer model, but intriguingly, it was hardly detected when the cancer model cells were cultured in vitro. These results imply that a signal originating from the microenvironment cooperates with NRF2 to activate Il11. To the best of our knowledge, this is the first report showing the influence of the microenvironment on the NRF2 pathway in cancer cells and the contribution of NRF2 to the secretory phenotypes of cancers. Disruption of Il11 in the NRF2 addiction cancer model remarkably inhibited the tumorigenesis, suggesting an essential role of IL-11 in NRF2-driven tumorigenesis. Thus, this study suggests that IL-11 is a potential therapeutic target for NRF2-addicted breast cancers.

Transgenic over-expression of MafK suppresses T cell proliferation and function in vivo.

BACKGROUND: The small Maf proteins regulate gene transcription from Maf recognition elements (MARE). These proteins do not contain a canonical transactivation domain. Depending upon the ratio of small Maf proteins to their partner proteins, which either possess a transactivation domain or not, transcription can be switched on or off. RESULTS: Transgenic mice were generated which over-express the small Maf family member MafK, specifically in the T cell lineage. It was our expectation that the high level of MafK would shift the balance to the formation of MafK homodimer and thereby repress MARE-dependent transcription. The transgenic mice had a shortened life span because of Pneumocystis carinii pneumonia and displayed a decrease in thymocytes and lower IL-2 and IL-4 mRNA expression levels. Analyses by electrophoretic gel mobility shift assay revealed that over-expressed MafK could interact with the proximal AP-1 sequence of IL-2 and the MARE in the IL-4 promoter region. CONCLUSION: These results indicate that when over-expressed, MafK binds to a MARE-like sequence and represses MARE-dependent transcription. Consequently, T cell proliferation and cytokine secretion are affected. The MafK homodimer serves as an important molecular probe for evaluating the role played by cis-acting MAREs in the proliferation and function of T cells.

[Therapeutic strategy for hepatic metastasis of primary colon cancer].

PURPOSE: To analyze the clinical results of treatments for hepatic metastasis of primary colon cancer for an evaluation of treatment strategies. MATERIALS AND METHODS: Two hundred and twenty-five patients with only hepatic metastasis of primary colon cancer (synchronous tumors, 164 patients: metachronous tumors, 61 patients) between 1983 and 1999 were studied. Of these 225 patients, 68 patients (synchronous tumors, 39 patients: metachronous tumors, 29 patients) were treated with curative resection. These 225 patients were categorized into group A (chemotherapy only), group B (hepatic arterial infusion only), group C (curative resection + hepatic arterial infusion), and group D (curative resection only). The therapeutic results were compared. RESULTS: The five-year survival rate and five-year recurrence-free rate of 68 patients with curative resection were 40.6% and 31.0%. By therapeutic modality, the five-year survival rate and five-year recurrence-free rate of the 36 patients of group C were 40.7% and 29.5%, and those of the 32 patients of group D were 43.4% and 33.0%, respectively. No significant difference was found between these two groups. However, in the patients with synchronous tumors, the five-year survival rate and five-year recurrence-free rate of group C and group D were 65.7, 49.6% and 13.8, 15.9%, respectively. The results of group C were significantly better than those of group D. Recurrence was found in 36 patients (52.2%). Among these patients, 25 (36.8%) recurred within one year from the end of treatment(s). Twenty-one patients (32.4) had the recurrence in the residual liver, and 14 (17.6%) had metastasis to the lung. In group B, in which curative resection was impossible, the one-year and two-year survival rates in the patients with synchronous tumors were good in comparison with those of group A. Herein we report two cases in which hepatic arterial infusion was effective. CONCLUSION: It is important to set aggressive resection and hepatic infusion as a fundamental treatment policy, and to perform not only hepatic infusion but to combine other treatments with consideration of the next recurrence.

[Significance of radical recurrent tumor resection for recurrent gastric cancer as assessed by prognosis].

To evaluate the relationship between radical surgery of recurrent tumor and prognosis in cases of recurrent gastric cancer, we analyzed data on 202 patients with relapsed gastric cancer, focusing on surgical recurrent tumor removal. In our series, 18 of the 202 patients underwent radical recurrent tumor resection. Resected tumors were located in the ovarium (n = 4), colorectum (n = 3), liver (n = 3), lymph node (n = 2), locoregional stoma (n = 2), and peritoneum, adrenal gland, brain, and lung (n = 1 each). No surgery-related mortality occurred. One patient remains alive over 5 years after hepatectomy without recurrence, and 17 died within 3 years: 7 patients from primary recurrence and 10 from multiple modes of recurrence. Median survival after recurrence (MSTAR) in the 18 radical surgery patients was 14 months, against 5 months in those treated palliatively (p = 0.0001). MSTAR for the ovary and the liver were 30 months and 15 months in the radical surgery cases, and 2.5 months for the ovary and 5 months for the liver in the palliative cases. Significant differences were thus seen between radical and palliative cases in the ovary (p = 0.010) and in the liver (p = 0.036). Median survival after gastrectomy was 45 months in the radical surgery cases, and 28 months in the palliative cases (p = 0.024). In postoperative gastric cancer follow-up, early detection of recurrence and radical surgery may well benefit patients with relapse, especially in the liver and ovary, in terms of survival.

X-ray absorption study of molten yttrium trihalides.

The local structure and structural changes in molten YCl3-LiCl-KCl and molten YBr3-LiBr systems have been investigated by using a high-temperature extended X-ray absorption fine structure (EXAFS) technique. The behaviour of octahedral coordination of the halide ion (Cl(-) and Br(-)) around the Y(3+) ion has been studied by EXAFS of the Y K-absorption edge. The nearest Y(3+)-Cl(-) and Y(3+)-Br(-) distances and coordination numbers of halide ions around the Y(3+) ion do not change by mixing with the alkali halides. The stabilization of the (YCl6)(3-) and (YBr6)(3-) octahedral coordination by adding alkali halides was suggested by decreasing the Debye-Waller factor and the anharmonicity in the nearest Y(3+)-Cl(-) and Y(3+)-Br(-) interactions. The bridging structure of the (YBr6)(3-) octahedra sharing a Br(-) ion in the molten YBr3-LiBr system was studied by EXAFS of the Br K-absorption edge. The coordination number of Y(3+) around the Br(-) ion decreases from 2 in the pure melt to almost 1 in the 30mol% and 15mol% YBr3 melts. This suggests that the bridging is almost broken and the stable octahedron exists freely in the LiBr-rich melts.

Should scirrhous gastric carcinoma be treated surgically? Clinical experiences with 233 cases and a retrospective analysis of prognosticators.

BACKGROUND/AIMS: The prognosis of patients with scirrhous gastric carcinoma has been poorest. METHODOLOGY: To clarify the role of surgical treatment, 233 patients with a primary scirrhous gastric carcinoma were retrospectively analyzed. RESULTS: Of the 233 patients, 182 underwent surgical resection, while the other 51 did not. The median survival time of those with unresectable tumors was 88.0 +/- 15.3 days and that of those who underwent resection was 380.0 +/- 41.8 days. In the 182 patients who underwent resection, multivariate analysis revealed four significant factors; lymphatic invasion, serosal invasion, curability, and lymph node dissection. Of these, curability was the most significant. The median survival time of patients whose tumor were curatively resected was 727.0 +/- 116.3 days, significantly longer than 272 +/- 34.9 days for those whose resection ended noncuratively. In 65 patients whose tumor was curatively resected, subset analyses of factors by multivariate analyses revealed an absence of serosal invasion as the single significant prognosticator. The 5-year survival rate was 55.6% in patients with scirrhous cancer without serosal invasion. CONCLUSIONS: For patients with scirrhous gastric carcinoma, palliative resection should not be attempted for poor outcome. However, if curative resection seems feasible, radical surgery would be justified, especially for tumors without serosal exposure.

Structural studies of lanthanide (III) complexes with oxydiacetic acid and iminodiacetic acid in aqueous solution by EXAFS.

The local structure of the trivalent lanthanide (Ln(III)) complexes with oxydiacetic acid (ODA) and iminodiacetic acid (IDA) in aqueous solution was investigated by EXAFS spectroscopy. The coordination number and the bond distance were obtained by the detailed EXAFS analysis. The coordination number of Ln(III) in both the Ln-ODA and -IDA systems decreases from nine for lighter Ln(III) to eight for heavier Ln(III). The bond distances of ether O atoms from Ln(III) in the Ln(ODA)(3)3- complexes are shorter than those of N atoms in the Ln(IDA)(3)3- ones.

[Significance of laparoscopy for response assessment of chemotherapy in gastric cancer].

UNLABELLED: We performed laparoscopy before and after chemotherapy in two patients with relapsed and advanced gastric cancer, whose major metastatic sites had been diagnosed as being in the peritoneum. A change in tumor responses when assessed by laparoscopy was found. Case 1: A 63-year-old man presented with an umbilical metastasis and suspected peritoneal metastases after gastrectomy. Laparoscopy revealed peritoneal metastases before chemotherapy. After one course of chemotherapy the umbilical tumor disappeared (CR). Laparoscopy after two courses of chemotherapy revealed increasing peritoneal metastases (PD). The overall response was PD. Case 2: A 67-year-old woman was referred to our hospital with a diagnosis of type 4 gastric cancer. Staging laparoscopy revealed massive lymph node metastases and the patient was positive in peritoneal washing cytology. After four courses of chemotherapy, the primary tumor and the metastatic lymph nodes had decreased in size (PR). In contrast, laparoscopy revealed increasing peritoneal metastases (PD). The overall response was PD. CONCLUSION: In patients with peritoneal and other modes of metastasis, tumor response to chemotherapy may be misjudged by conventional imaging alone. Intraperitoneal examination by laparoscopy provides accurate information, including the tumor response to chemotherapy.

Expression of peptide transporter following intestinal transplantation in the rat.

BACKGROUND: The absorptive function of the intestinal graft is one of the most important factors for successful intestinal transplantation. To clarify whether the intestinal H(+)/peptide cotransporter (PEPT1) was expressed in the transplanted intestine, we examined the expression of PEPT1 in an experimental model of rat small intestinal transplantation in comparison with expression of Na(+)/glucose cotransporter (SGLT1). MATERIALS AND METHODS: Heterotopic intestinal transplantation was performed in allogeneic and syngeneic rat strain combinations. An additional group of allogeneic recipients was treated with tacrolimus (1 mg/kg) prior to transplantation, then daily for 7 days. Intestinal grafts were examined for histopathology and PEPT1 and SGLT1 expression. RESULTS: In the isografts, the levels of messenger RNA (mRNA) encoding both transporters were not changed, while the amount of SGLT1 protein was decreased and that of PEPT1 protein was increased. In the allografts, mRNA level and protein amount of both transporters and the amount of villin protein were decreased, and microscopic examination revealed histopathological features of rejection on day 7. Tacrolimus treatment ameliorated the histopathological features and prevented the decrease in villin protein expression. However, the decreases in PEPT1 and SGLT1 expression (both mRNA and protein) were partially prevented by tacrolimus treatment. CONCLUSION: This study indicated that the expression of transporters should be determined to evaluate intestinal graft function in addition to histopathological examination of the mucosa and that the levels of mRNA encoding intestinal nutrient transporters in biopsy specimens may be useful for evaluating the intestinal graft function for intestinal transplant patients.

Intratumoral concentrations of tissue inhibitor of matrix metalloproteinase 1 in patients with gastric carcinoma a new biomartker for invasion and its impact on survival.

BACKGROUND: Previously, the authors clarified that the plasma concentration of tissue inhibitor of matrix metalloproteinase 1 (TIMP-1) in patients with gastric carcinoma was a significant predictor of tumor invasiveness and metastasis. METHODS: To further clarify the clinical significance of TIMP-1, the authors used an enzyme-linked immunoassay to assess TIMP-1 protein concentrations in samples of tumor tissue from 86 patients who underwent primary resection for gastric carcinoma. Concentrations in samples of normal gastric mucosa from 73 of these patients also were assessed. RESULTS: Tissue TIMP-1 concentrations were significantly greater in gastric tumors than in normal gastric mucosa and were associated significantly with a variety of pathologic factors, including macroscopic type, depth of tumor invasion in the gastric wall, presence of lymphatic vessel invasion, pattern of tumor infiltration into the surrounding tissue, and disease stage. Significantly greater TIMP-1 concentrations were found in tumors that were exposed to the serosal surface compared with tumors that were limited to the submucosal layer. TIMP-1 protein was significantly greater in tumors with lymphatic vessel invasion, an infiltrative pattern into the surrounding tissue (INF-gamma), and in tumors from patients with Stage III disease. Survival was significantly poorer in patients with TIMP-1 concentrations > or = 10.0 ng/mg total protein. When patients were stratified by disease stage, survival was significantly different in patients with Stage III disease. Multivariate analysis demonstrated that intratumoral concentrations of TIMP-1 were the most significant independent factor for survival. CONCLUSIONS: These findings suggest that the intratumoral concentration of TIMP-1 protein may be a good indicator of tumor aggressiveness and can serve as a significant independent predictor of survival in patients with gastric carcinoma.

Effect of acoustic overstimulation on regulation of glucocorticoid receptor mRNA in the cochlea of the guinea pig.

Semi-quantitative reverse transcription polymerase chain reaction was performed to determine the distribution of mRNA levels of glucocorticoid receptor (GR) within the guinea pig cochlea and to examine the change in their expression after acoustic overstimulation. Using an original PCR primer for the guinea pig, the highest GR mRNA level was revealed in the modiolus and lowest in the medial portion including the organ of Corti. Total RNA was extracted from the whole cochlea of the guinea pig 0, 2, 6 and 24 h after exposure to a 2 kHz pure tone of 110, 120 or 130 dB SPL for 10 min. The level of GR mRNA significantly decreased immediately and 2 h after exposure to the sound of 120 dB SPL, and 2 and 6 h after exposure to that of 130 dB SPL. These results suggest the presence of a down-regulation of GR mRNA induced by acoustic overstimulation, although the exact mechanism of this phenomenon remains unsolved.

Clinicopathologic differences between early gastric remnant cancer and early primary gastric cancer in the upper third of the stomach.

BACKGROUND/AIMS: This study was designed to clarify the clinicopathologic characteristics and survival in early gastric remnant cancer and compare with early primary cancer in the upper third of the stomach. METHODOLOGY: Twenty-five patients with early gastric remnant cancer, who underwent resection at Kanagawa Cancer Center and First Department of Surgery, Yokohama City University between 1974 and 1996 were evaluated in this study. Various clinicopathologic characteristics, such as age, sex, symptoms, size of tumor, depth of invasion, lymph node metastasis, cell differentiation, and survival were investigated and early gastric remnant cancer was compared with early primary cancer in the upper third of the stomach. RESULTS: According to the macroscopic type, protruded type such as I or II type accounted for a great majority in early gastric remnant cancer, while II c depressed type was common in early primary cancer in the upper third of the stomach, comprising 64.2% of all cases. Pathological examination disclosed that well-differentiated carcinoma and mucosal carcinoma were more frequently observed in early gastric remnant cancer than in early primary cancer in the upper-third of the stomach. The 5-year survival rate was 83.5% for early primary cancer in the upper-third of the stomach. In contrast, no patients experienced recurrence after operation for early gastric remnant cancer. CONCLUSIONS: From the view point of clinicopathological evaluation, gastric remnant cancer is a special from of gastric cancer. A follow-up program is important in order to detect early gastric remnant cancer. A low incidence of lymph node metastasis suggests that endoscopic mucosal resection of the tumor or limited operation could be performed under strict indication.

One enhancer mediates mafK transcriptional activation in both hematopoietic and cardiac muscle cells.

Members of the small Maf family of transcription factors play important roles in hematopoiesis. Using transgenic assays, we discovered a tissue-specific enhancer 3' to the mafK gene. This enhancer directs mafK transcription in hematopoietic as well as in developing cardiac muscle cells, and was thus designated the hematopoietic and cardiac enhancer of mafK (HCEK). Only two of four GATA consensus motifs identified within HCEK contributed to enhancer activity, and both of these sites were required for both cardiac and hematopoietic transcriptional activation. The expression profile of MafK significantly overlapped that of GATA-1 in hematopoietic cells and of GATA-4/-6 in cardiac tissues. Each of these GATA factors bound with high specificity to both of the critical GATA sites in HCEK. Hence, the mafK gene is regulated by different GATA proteins in the hematopoietic and cardiac compartments through the same two GATA-binding sites in HCEK. These data provide the first in vivo demonstration that distinct members of a related transcription factor family activate the tissue-specific expression of a single target gene using the same cis-regulatory element.

Oxidative stress abolishes leptomycin B-sensitive nuclear export of transcription repressor Bach2 that counteracts activation of Maf recognition element.

The mammalian transcription activator Nrf2 plays critical roles in executing oxidative stress response by binding to the regulatory DNA sequence Maf recognition element. Bach2 is an Nrf2-related transcription repressor and a tissue-specific partner of the Maf oncoprotein family. We show here how Bach2 is regulated by an oxidative stress-sensitive conditional nuclear export. In cultured cells, Bach2 was localized in cytoplasm through its C-terminal evolutionarily conserved cytoplasmic localization signal (CLS). The CLS directed leptomycin B-sensitive nuclear export of reporter proteins, suggesting its dependence on the nuclear exporter Crm1/exportin 1. However, the CLS sequence does not bear a resemblance to the leucine-rich class of nuclear export signal, and mutagenesis analysis indicated that a stretch of nonhydrophobic amino acids is essential for its activity. Oxidative stressors aborted the CLS activity and induced nuclear accumulation of Bach2. Whereas oxidative stress is known to activate MARE-dependent transcription, overexpression of Bach2 in cultured cells silenced the inducibility of MARE. The results suggest that Bach2 mediates nucleocytoplasmic communication to couple oxidative stress and transcription repression in mammalian cells.

Prognostic value of tissue inhibitor of matrix metalloproteinase-1 in plasma of patients with gastric cancer.

Tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) in plasma has been reported to be related to disease progression in patients with gastric cancer. However, the prognostic significance of plasma TIMP-1 concentrations has not been clarified. Concentrations of TIMP-1 protein were measured by enzyme-linked immuno-sorbent assay in plasma samples of 147 preoperative patients who subsequently underwent gastric resection, and prognosis was compared. The cut-off value of plasma TIMP-1 concentrations was defined as 112.5 ng/ml, referring to the TIMP-1 levels in patients with intramucosal gastric cancer. Twenty-nine out of 147 patients had higher plasma TIMP-1 levels than the cut off value. When the patients were divided into those with elevated values and those with normal TIMP-1, such parameters as age, serosal invasion, metastases to lymph nodes, peritoneum, and liver, lymphatic invasion, curability, and stage were significantly different between the two. By univariate analysis of the factors affecting survival, macroscopic type, histology, serosal invasion, metastasis to lymph node, peritoneum, and liver, vessel invasions, curability, and plasma TIMP-1 were significant. However, multivariate analysis revealed that TIMP-1 was the only significant factor. In patients with gastric cancer, plasma TIMP-1 seem to be an independent and most powerful prognosticator for the survival.

Plasma concentrations of VEGF and bFGF in patients with gastric carcinoma.

We examined plasma levels of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in 54 patients with gastric carcinoma. Postoperative survival was significantly poorer in patients with plasma VEGF levels more than 10.0 pg/ml at the time of surgery. By an univariate analysis of the factors affecting survival, serosal invasion, lymph node metastasis, peritoneal dissemination, lymphatic vessel invasion, curability, and VEGF proteins were significant. By a multivariate analysis only VEGF levels and curability remained significant. Patients with recurrent disease, including liver metastasis, had significantly higher plasma VEGF concentrations than those with resectable primary tumors. VEGF, not bFGF, may serve as an independent prognosticator and a sensitive indicator for liver recurrence in patients with gastric carcinoma.

Perinatal synthetic lethality and hematopoietic defects in compound mafG::mafK mutant mice.

Prior studies exploring the mechanisms controlling erythroid gene regulation implicated MARE (Maf recognition element) cis-elements as crucial to the transcriptional activity of many erythroid genes. Numerous transcription factors can elicit responses through MAREs, including not only the AP-1 family proteins, but also a growing list of factors composed of Cap-N-Collar (CNC)-small Maf heterodimers. While these factors can activate transcription from MAREs in co-transfection assays, mouse germline mutations in cnc genes tested to date have failed to reveal primary erythroid phenotypes. Here we report that after combining the mafK and mafG targeted null alleles, mutant animals display several synthetic phenotypes, including erythroid deficiencies. First, compound homozygous small maf gene mutants survive embryogenesis, but die postnatally. Secondly, compound mutant animals develop severe neurological disorders. Thirdly, they exhibit an exacerbated mafG deficiency in megakaryopoiesis, specifically in proplatelet formation, resulting in profound thrombocytopenia. Finally, the compound mutant animals develop severe anemia accompanied by abnormal erythrocyte morphology and membrane protein composition. These data provide direct evidence that the small Maf transcription factors play an important regulatory role in erythropoiesis.

Angiogenesis inhibitor, TNP-470, suppresses growth of peritoneal disseminating foci.

BACKGROUND/AIMS: Angiogenesis is critical not only for growth of primary tumors but also for cells established at distant organs. We investigated the effects of angiogenesis inhibitor, TNP-470, on the establishment and growth of intraperitoneally inoculated human gastric cancer cell line, MKN-45, and survival of nude mice with this tumor. METHODOLOGY: Human gastric cancer cell line, MKN-45, were injected into the peritoneal cavity of an ICR nude mouse and a model of peritoneal dissemination was developed. TNP-470 was injected subcutaneously every other day from day 1 until sacrifice or death. The effects of TNP-470 on MKN-45 cells were also examined in vitro. RESULTS: Although the number of disseminated foci was not significantly different, the maximum size was significantly smaller in a TNP-treated group than those of a control. Survival time was significantly longer in a TNP-treated group. TNP-470 demonstrated no growth inhibition of MKN45 cells in vitro. CONCLUSIONS: Those results suggested that anti-angiogenic agent, TNP-470, might be effective in treating peritoneal dissemination of gastric cancer by inhibiting growth of the seeded tumor cells on the peritoneum.