Shozo Baba

Anti-tumor and anti-metastatic effects of human-vascular-endothelial-growth-factor-neutralizing antibody on human colon and gastric carcinoma xenotransplanted orthotopically into nude mice

In order to determine whether the inhibition of vascular‐endothelial‐growth‐factor (VEGF) activity by administration of an immunoneutralizing antibody could suppress tumor growth and metastasis in spontaneous metastatic models of human colon and gastric carcinoma, 4 human carcinoma xenografts, 2 human colon carcinomas (TK4 and TK13) and 2 gastric carcinomas (MT2 and MT5) were transplanted orthotopically into nude mice. The anti‐VEGF antibody (MV833, 100 μg/mouse) or the same volume of saline was administered i.p. on alternative days from day 10 after transplantation. With each of the 4 xenografts, administration of MV833 significantly inhibited not only primary tumor growth but also macroscopic liver metastasis, although the growth rate varied. The inhibitory effect of MV833 on primary tumor growth appeared to have no correlation with the level of VEGF in tumor. Body‐weight gain in each treated group was comparable with that in the control group. No toxicity of the antibody was observed. These results suggest that an anti‐VEGF antibody can be effective against a wide variety of cancers, and that VEGF may be a possible target for cancer therapy. Int. J. Cancer 77:933–936, 1998.© 1998 Wiley‐Liss, Inc.

Resection of Liver Metastases of Colorectal Carcinoma

Abstract. Hepatic metastasis of colorectal cancer is a life-threatening prognostic factor. The present review revealed that hepatic resection is the best treatment modality, although the overall survival rate after hepatectomy for metastatic colorectal cancer is still low (20–40%). Various prognostic factors analyzed by many authors are controversial. The number of hepatic metastases and the surgical margin were the most important prognostic factors, as seen in 10 papers previously reported including our data. A clear surgical margin is achievable, but the prognosis of patients with four or more metastatic nodules in the liver remains poor. Repeat hepatectomy is also evaluated and is believed by many surgeons to have acceptable mortality. It improved survival to a certain extent. Analysis of the biologic characteristics of primary and metastatic tumors is extremely important and is urgently indicated.

Suspected hereditary nonpolyposis colorectal cancer : international collaborative group on hereditary non-polyposis colorectal cancer (ICG-HNPCC) criteria and results of genetic diagnosis

PURPOSE: The aim of this study was to determine the frequency of mutations in the mismatch repair genes in families suspected of having hereditary nonpolyposis colorectal cancer. METHODS: We devised two criteria for families suspected of having hereditary nonpolyposis colorectal cancer (Criteria I and II). Criteria I consist of at least two first-degree relatives affected with colorectal cancer with at least one of the following: development of multiple colorectal tumors including adenomatous polyp, at least one colorectal cancer case diagnosed before the age of 50, and occurrence of a hereditary nonpolyposis colorectal cancer extracolonic cancer (endometrium, urinary tract, small intestine, stomach, hepatobiliary system, or ovary) in family members. Criteria II consist of one colorectal cancer patient with at least one of the following: early age of onset (<40 years); endometrial, urinary tract, or small intestine cancer in the index patient or a sibling (one aged <50 years); and two siblings with other integral hereditary nonpolyposis colorectal cancer extracolonic cancers (one aged <50 years). A questionnaire was mailed to members of the International Collaborative Group on Hereditary Non-Polyposis Colorectal Cancer to determine the mutation detection rate in mismatch repair genes from the families fulfilling these criteria. For comparison the mutation detection rate for families fulfilling the Amsterdam hereditary nonpolyposis colorectal cancer criteria in each institution was also obtained. RESULTS: Data were obtained from eight different institutions (in 7 different countries). In a total of 123 patients from 123 families (67 families fulfilling Criteria I and 56 families fulfilling Criteria II), genetic testing for germline mismatch repair gene variants was performed. Germline mutations of the hMLH1 or hMSH2 genes were identified in 24 families (20 percent). Of these, the mutation detection rate for families fulfilling Criteria I was 28 percent (19/67). The mutation detection rate for families fulfilling Criteria II was 9 percent (5/56). In these eight institutions, the overall mutation detection rate for families fulfilling the Amsterdam hereditary nonpolyposis colorectal cancer criteria was 50 percent (77/154). CONCLUSION: The Criteria I for suspected hereditary nonpolyposis colorectal cancer have the advantages that they can be applied to nuclear families and they can include extracolonic cancers. The results of this study suggest that families fulfilling Criteria I should be offered genetic testing. The relatively low mutation detection rate in those families fulfilling Criteria II suggests that, using current techniques, genetic testing in these families is not practical.

Hepatic release of endothelin-1 after warm ischemia. Reperfusion injury and its hemodynamic effect.

This study investigated the release of endothelin (ET)-1 from the liver after warm ischemia/reperfusion (I/R) injury. Wistar rats were subjected to 120 min of warm hepatic ischemia by clamping the hepatic hilum under porto-jugular shunting. Reperfusion was performed by unclamping. The rats were divided into 2 groups receiving intravenous treatment with an anti-ET-1 mAb before ischemia (AET group) and with mouse immunoglobulin G (sham group). Hepatic blood flow was assessed by laser-Doppler flowmetry and reflectance spectrophotometry and was compared between the 2 groups along with the bile flow rate. The ET-1 concentrations of hepatic venous and portal blood were determined in the sham group, and the portal blood endotoxin levels were assayed in both groups. Both groups developed transient hypotension after reperfusion, but hepatic blood flow subsequently showed a significant improvement in the AET group. Hepatic congestion was detected in the sham group by both reflectance spectrophotometry and histological examination. After reperfusion, bile flow was significantly greater in the AET group. The portal endotoxin concentration showed no increase in both groups, and the hepatic venous blood ET-1 level in the sham group was significantly higher until 3 hr after reperfusion compared to the portal blood level. The 30-day survival rate was 50% in the AET group, whereas all the sham rats died within 12 hr. ET-1 was released from the liver after I/R injury and apparently participated in systemic and local hemodynamic changes that affected survival.

Cytoplasmic beta-catenin accumulation as a predictor of hematogenous metastasis in human colorectal cancer.

The membranous, cytoplasmic and nuclear levels of beta-catenin were evaluated immunohistochemically in archival tissue specimens from 96 Japanese patients with primary colorectal carcinoma who had undergone surgery. The relationships between beta-catenin and clinicopathological variables were analyzed statistically. Reduced beta-catenin immunoreactivity in the cell membranes of cancer cells was found in 70% of the tumors, and cytoplasmic and nuclear accumulation of beta-catenin were found in 68 and 66% of tumors, respectively. Significant correlations between cytoplasmic beta-catenin accumulation and the depth of invasion, venous invasion and focal dedifferentiation were observed. Cytoplasmic beta-catenin accumulation was also found to be a useful predictor of hematogenous metastasis (hazard ratio = 8.94, p = 0.054), though neither a reduced cell membrane level nor nuclear accumulation of beta-catenin correlated with metastasis.

Suspected HNPCC and Amsterdam criteria II: evaluation of mutation detection rate, an international collaborative study

Abstract. Background and aims: The Korean Hereditary Tumor Registry has proposed criteria for suspected hereditary nonpolyposis colorectal cancer (S-HNPCC criteria I and II) and confirmed their validity in an international collaborative study. The S-HNPCC criteria included families that did not fulfill the Amsterdam criteria, but in whom HNPCC was nevertheless strongly suspected. The S-HNPCC criteria was also revised accordingly since some S-HNPCC families now fullfil the revised Amsterdam criteria. The original Amsterdam criteria have recently been revised, including some extracolonic cancers. This study compared the mutation detection rates between the revised and previous Amsterdam and S-HNPCC criteria. Patients and methods: Data on the mutational status of 393 HNPCC suspected families were collected from ten different institutes. Two hundred families were categorized into old S-HNPCC criteria (142 into criteria I and 58 into criteria II) and 193 families into Amsterdam criteria I. Results: Of the 142 old S-HNPCC criteria I families 24 fulfilled the Amsterdam criteria II as the data were reclassified according to the revised criteria, increasing the proportion of the families fulfilling the Amsterdam criteria by 12.4%. The mutation detection rate of the revised criteria was very little changed compared to the old criteria; 26% and 27% in the S-HNPCC criteria, and 50% and 52% in the Amsterdam criteria. Conclusion: The mutation detection rate is hardly affected by the revision of the Amsterdam criteria although the population of patients fulfilling the criteria is increased. The value of revised S-HNPCC criteria is equivalent to that of as the old S-HNPCC criteria in selecting of candidate patients for genetic testing.

Nine novel germline mutations of STK11 in ten families with Peutz-Jeghers syndrome

Abstract Peutz-Jeghers Syndrome (PJS) is an autosomal dominant hereditary disease characterized by hamartomatous polyposis involving the entire bowel. Recently STK11, a gene bearing a mutation responsible for PJS, was isolated. We investigated the entire coding region of STK11 in 15 unrelated PJS families by the PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism) method and PCR-direct sequence analysis, and found nine different, novel mutations among ten of those families. One nonsense mutation and five different frameshift mutations (two families carried the same mutation), all of which would cause truncation of the gene product, were found in seven families; mutations found in five families were clustered within exon 6. Among these five mutations, three occurred at the mononucleotide-repeat region (CCCCCC) of codons 279–281, suggesting that this region is likely to be a mutational hotspot of this gene. One of the remaining three families carried a 3-bp in-frame deletion that would eliminate an asparagine residue within a kinase domain of the product; the other two carried intronic mutations at or adjacent to the consensus dinucleotide sequences of splice-acceptor or -donor sites, which were likely to lead to aberrant splicing.

Piroxicam and acarbose as chemopreventive agents for spontaneous intestinal adenomas in APC gene 1309 knockout mice

The use of nonsteroidal anti‐inflammatory drugs has been suggested to have a chemopreventive effect against colon carcinoma, through the inhibition of cyclooxygenases 1 and 2, in patients with familial adenomatous polyposis and in animal models. Acarbose, an alpha‐glycosidase inhibitor, may also be chemopreventive. In order to examine the effects of these drugs we employed APC gene knockout mice randomized into 3 groups, one for treatment with piroxicam (0.05% concentration in drinking water), one for acarbose (0.04% concentration in food) and another for the control. After 14 weeks of treatment, mice were killed for quantitation of gastric and intestinal adenomas. Tumor multiplicity in the whole gastrointestinal tract decreased from 33.89±13.07 tumors/mouse in the control group to 17.05±7 tumors/mouse in the piroxicam‐treated group (P<0.001). The decrease in the acarbose‐treated group (29.68±12.86 tumors/mouse) was not significant (P>0.05). The number of tumors ≥3 mm in diameter was also quantified in all gastrointestinal segments. The number of such tumors in the piroxicam group was decreased to 0.56±1.2 tumors/mouse from the control value of 3.78±1.17 tumors/mouse (P<0.001), while in the acarbose‐treated group the number decreased to 2.36±1.7 tumors/mouse (P<0.01). Thus, piroxicam decreases the size and number of gastrointestinal adenomas in APC 1309 knockout mice, while acarbose decreases only the size.

The beneficial effect of a prostaglandin I2 analog on ischemic rat liver.

This study was undertaken to determine whether or not prostaglandin I2 (PGI2) analog pretreatment could successfully preserve organ viability after warm hepatic ischemia in rats. Although 120-min ischemia of the liver did not permit survival in rats administered normal saline solution (NS group) before warm ischemia, the survival rate of PGI2 analogue (500 ng/kg/min)—treated rats (PG group) significantly improved to 57% (P<0.05). Recirculation following 120-min hepatic ischemia in the NS group resulted in no improvement of B-phosphorus of the ATP (B-ATP)/inorganic phosphate (Pi) ratio measured by 31P nuclear magnetic resonance, a marked increase in the serum asparate aminotransferase (SAST) level, and an increase in the malondialdehyde (MDA) level in liver tissue. In the PG group, the B-ATP/Pi ratio was significantly improved (P<0.05), the elevation in SAST was also markedly suppressed (P<0.05), and the MDA level of the liver was lowered more than that in the NS group. Severe congestion and extensive vacuolization of hepatocytes from the peripheral to the midzonal areas were histologically exhibited with single-cell necrosis in the NS group. There were fewer histological alterations of the liver and these coincided with the changes in other parameters in the PG group. Our results indicate that PGI2 analog reduces warm ischemic injury of the liver and provides greater protection for organs to be transplanted.

Increase in levels of plasminogen activator and type-1 plasminogen activator inhibitor in human breast cancer: possible roles in tumor progression and metastasis.

We measured antigen levels of two kinds of plasminogen activators, tissue type plasminogen activator (t-PA) and urokinase type plasminogen activator (UK), as well as their primary inhibitor, type-1 plasminogen activator inhibitor (PAI-1) in the tissue extracts of benign and malignant breast tumors. Tumor tissues of 36 fibroadenomas and 39 breast cancers were examined. t-PA levels were not different in both groups. Malignant tumors contained the significantly higher levels of UK than benign tumors (p less than 0.001). Furthermore in breast cancer tissues, UK antigen levels of tumors with axillary lymph node involvements were significantly higher than those of tumors without lymph node involvements (p less than 0.05). PAI-1 antigen levels of breast cancer tissues were dramatically higher than those of fibroadenoma (p less than 0.001). PAI-1 levels of node positive carcinomas showed also values significantly higher than node negative ones (p less than 0.01). When we divided cancer tissues into three groups as node negative tumors, tumors with positive axillary nodes fewer than four and tumors with four or more positive nodes, PAI-1 levels increased corresponding to the progression of lymph node involvements (p less than 0.05). Immunohistochemical studies, using mouse monoclonal antibodies to human UK and PAI-1, showed that those immunoreactivities were diffusely distributed in the cytoplasm of human breast cancer cells. Their staining patterns were very similar to each other.