DAP12 deficiency in liver allografts results in enhanced donor DC migration, augmented effector T cell responses and abrogation of transplant tolerance.

Liver interstitial dendritic cells (DC) have been implicated in immune regulation and tolerance induction. We found that the transmembrane immuno-adaptor DNAX-activating protein of 12 kDa (DAP12) negatively regulated conventional liver myeloid (m) DC maturation and their in vivo migratory and T cell allostimulatory ability. Livers were transplanted from C57BL/6(H2(b) ) (B6) WT or DAP12(-/-) mice into WT C3H (H2(k) ) recipients. Donor mDC (H2-K(b+) CD11c(+) ) were quantified in spleens by flow cytometry. Anti-donor T cell reactivity was evaluated by ex vivo carboxyfluorescein diacetate succinimidyl ester-mixed leukocyte reaction and delayed-type hypersensitivity responses, while T effector and regulatory T cells were determined by flow analysis. A threefold to fourfold increase in donor-derived DC was detected in spleens of DAP12(-/-) liver recipients compared with those given WT grafts. Moreover, pro-inflammatory cytokine gene expression in the graft, interferon gamma (IFNγ) production by graft-infiltrating CD8(+) T cells and systemic levels of IFNγ were all elevated significantly in DAP12(-/-) liver recipients. DAP12(-/-) grafts also exhibited reduced incidences of CD4(+) Foxp3(+) cells and enhanced CD8(+) T cell IFNγ secretion in response to donor antigen challenge. Unlike WT grafts, DAP12(-/-) livers failed to induce tolerance and were rejected acutely. Thus, DAP12 expression in liver grafts regulates donor mDC migration to host lymphoid tissue, alloreactive T cell responses and transplant tolerance.

Congenital portopulmonary shunt in a cat.

A 9-year-old spayed female crossbreed cat with chief complaints of anorexia and hypersalivation had high serum concentrations of ammonia and fasting and postprandial total bile acid. Therefore, she was referred to our hospital. On the first evaluation, haematology, serum chemistry, radiography and ultrasonography findings suggested that she had a congenital portosystemic shunt. CT revealed a shunt vessel from the left gastric vein to the left pulmonary vein. During median celiotomy and sternotomy, gross findings and mesenteric portography revealed abnormal vessel shunting from the left gastric vein to the left pulmonary vein. Complete ligation of the shunt vessel was achieved. She recovered without any complications. Postoperative serum chemistry revealed that ammonia and total bile acid levels decreased to within the reference intervals. This report is the first to describe the clinical features and surgical outcome of a cat with a congenital portopulmonary shunt.

Transarterial chemoembolisation for palliative treatment of renal cell carcinoma in two dogs with pulmonary metastasis.

Two dogs with anorexia and rapid weight loss were referred to our hospital due to a right renal mass and several pulmonary nodules. Both dogs underwent needle core biopsy of the mass, followed by transarterial chemoembolisation of the renal mass. A catheter was inserted from the femoral artery and advanced into the right renal artery. A suspension of carboplatin (100 mg/m2 ) and equivalent lipiodol was administered via the inserted multipurpose catheter. Immediately after, under fluoroscopic guidance, pulse injections of small amounts of gelatin particles (diameter 1 mm) dissolved in iohexol were administered until complete embolisation of the renal artery. Histopathologic diagnosis was renal cell carcinoma in both dogs. Clinical signs improved for 134 and 358 days after transarterial chemoembolisation. In addition, postoperative radiographs demonstrated a decrease in the tumour size. The dogs died 215 and 525 days after the initial evaluation, respectively. As a palliative treatment, transarterial chemoembolisation might help reduce the tumour volume and improve the quality of life in dogs with renal cell carcinoma and distant metastases.

A glycine-rich RNA-binding protein mediating cold-inducible suppression of mammalian cell growth.

In response to low ambient temperature, mammalian cells as well as microorganisms change various physiological functions, but the molecular mechanisms underlying these adaptations are just beginning to be understood. We report here the isolation of a mouse cold-inducible RNA-binding protein (cirp) cDNA and investigation of its role in cold-stress response of mammalian cells. The cirp cDNA encoded an 18-kD protein consisting of an amino-terminal RNAbinding domain and a carboxyl-terminal glycine-rich domain and exhibited structural similarity to a class of stress-induced RNA-binding proteins found in plants. Immunofluorescence microscopy showed that CIRP was localized in the nucleoplasm of BALB/3T3 mouse fibroblasts. When the culture temperature was lowered from 37 to 32 degrees C, expression of CIRP was induced and growth of BALB/3T3 cells was impaired as compared with that at 37 degrees C. By suppressing the induction of CIRP with antisense oligodeoxynucleotides, this impairment was alleviated, while overexpression of CIRP resulted in impaired growth at 37 degrees C with prolongation of G1 phase of the cell cycle. These results indicate that CIRP plays an essential role in cold-induced growth suppression of mouse fibroblasts. Identification of CIRP may provide a clue to the regulatory mechanisms of cold responses in mammalian cells.

Production of urinary bladder carcinomas in mice by sodium saccharin.

Pellets weighing 20 to 24 milligrams and containing 20 percent sodium saccharin suspended in cholesterol were surgically implanted into the urinary bladder lumens of female Swiss mice (60 to 90 days old) under ether anesthesia. Incidences of mouse bladder carcinomas in animals exposed to these pellets were 47 and 52 percent as compared with incidences of 13 and 12 percent in control mice exposed to pellets of pure cholesterol. The exposure of the mouse bladder to saccharin was very brief, because the time required for 50 percent of the compound to be eluted from the pellets was about 5.5 hours.

Impaired dendritic cell functions because of depletion of natural killer cells disrupt antigen-specific immune responses in mice: restoration of adaptive immunity in natural killer-depleted mice by antigen-pulsed dendritic cell.

The primary aim of this study was to evaluate the role of natural killer (NK) cells on antigen-specific adaptive immune responses. After analysing the mechanism of impaired adaptive immune responses of NK-depleted mice, an immune interventional approach was developed to restore adaptive immunity in NK-depleted mice. NK cells were depleted from mice by administration of anti-asialo GM1 antibody (100 mul/mouse), twice, at an interval of 48 h. Hepatitis B surface antigen (HBsAg) was administered intraperitoneally to normal C57BL/6 mice (control mice) and NK-depleted mice. The levels of antibody to HBsAg (anti-HBs) in the sera and HBsAg-specific lymphocytes in the spleen were assessed. The functions of T lymphocytes, B lymphocytes and dendritic cells (DCs) were evaluated in vitro. HBsAg-pulsed DCs were prepared by culturing spleen DCs with HBsAg for 48 h and administered once to NK-depleted mice. The levels of anti-HBs in the sera and HBsAg-specific lymphocytes were significantly lower in NK-depleted mice compared with control mice (P < 0.05). The functions of T and B lymphocytes were similar between control mice and NK-depleted mice. However, the functions of spleen DC and liver DC were significantly lower in NK-depleted mice compared with control mice (P < 0.05). Administration of HBsAg-pulsed DCs, but not HBsAg, induced HBsAg-specific humoral and cellular immune responses in NK-depleted mice. Our study suggests that cross-talk between NK cells and DCs regulates the magnitude of adaptive immunity. In addition, antigen-pulsed immunogenic DCs represent potent immune modulator even if subjects with diminished innate immunity.

Activation of H-ras oncogene in rat bladder tumors induced by N-butyl-N-(4-hydroxybutyl)nitrosamine.

Ras-oncogene activation was investigated in the bladder tumors of F344 male rats given N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in drinking water. DNA from one of the nine transitional cell carcinomas contained an H-ras oncogene detectable by the NIH/3T3 transfection assay. Analysis of p21 ras proteins suggested that the activating mutation resided within codon 61 of the H-ras gene and that such activating mutations were not present in other tumors. In contrast to mutational activation of ras genes, enhanced expression of p21 was observed in all tumors examined by immunohistochemical techniques with the use of Formalin-fixed paraffin-embedded tissue sections and an anti-ras p21 antibody, RAP-5. Further histochemical analysis of bladder tissues at various stages of the BBN-induced carcinogenic process indicated that the enhanced expression of p21 appeared early; the reactivity with RAP-5 was observed in diffuse hyperplastic epithelia after 5 weeks of exposure to BBN. The frequency of ras oncogenes, activated either by point mutations or overexpression of p21, in BBN-induced rat bladder carcinomas has thus been shown to be similar to that observed in human bladder carcinomas.

MDR1 RNA levels in human renal cell carcinomas: correlation with grade and prediction of reversal of doxorubicin resistance by quinidine in tumor explants.

We examined the distribution of RNA levels expressed by the multidrug-resistance gene (MDR1, also known as PGY1) in 42 renal cell carcinoma (RCC) samples (38 primary and four metastatic lesions). The median MDR1 RNA level for the 38 primary lesions, expressed relative to the level for KB-3-1 cells, was approximately one-half of the level in multidrug-resistant KB-8-5 cells. Elevated MDR1 RNA levels were also observed in three of the four metastatic lesions. The mean MDR1 RNA level was higher in well-differentiated RCCs than in those that were poorly differentiated, suggesting that the increased expression of the MDR1 gene in RCCs originates from the increased expression in renal proximal tubule cells. To clarify the association of the MDR1 protein product P-glycoprotein with natural resistance to doxorubicin (ADR) in RCCs, we evaluated the effects of quinidine on in vitro sensitivity to ADR in 16 RCC samples, using a [3H]thymidine incorporation assay. The enhancing effect of quinidine (7.5 micrograms/mL) on sensitivity to ADR was statistically significant only in the group with high MDR1 RNA levels. Similar enhancement by quinidine of sensitivity to ADR was also observed in the established RCC cell lines in which MDR1 RNA levels were high. These results suggest that P-glycoprotein is active in the natural resistance of RCCs to ADR.

Oncogene amplification in urothelial cancers with p53 gene mutation or MDM2 amplification.

BACKGROUND: Previously, p53 (also known as TP53) gene mutations have been shown to be frequently detected in highly malignant urothelial cancers. Evidence has been accumulating that the disruption of the normal function of p53 may lead to genomic instability, including predisposition to gene amplification. Furthermore, the normal function of p53 may be abrogated by MDM2 (murine double minute-2) gene amplification in some human tumors. PURPOSE: Our purpose was to investigate the relationship between protooncogene amplification and p53 alteration in urothelial cancers by examining the existence of amplification of MDM2 and 14 other protooncogenes in 50 urothelial tumors in which p53 gene status was known. METHODS: We analyzed gene amplification by Southern-blot analysis in 50 urothelial cancer specimens. These tumors were previously examined for p53 mutations by polymerase chain reaction-single-strand conformation analysis, and 17 tumors contained p53 mutations. RESULTS: Two high-grade advanced tumors (4%) without p53 mutation harbored MDM2 amplification with concurrent int-2 gene amplification. As for other genes, amplification was detected for int-2 (also known as WNT2) (seven [14%] of 50), erbB-2 (also known as ERBB2) (three [6%] of 50), N-ras (also known as NRAS) (one [2%] of 50), L-myc (also known as MYCL1) (one [2%] of 50), and raf-1 (also known as RAF1) (one [2%] of 50). The amplification of at least one gene examined was observed in 11 (22%) of 50 tumors. The presence of p53 mutations was not significantly associated with the occurrence of gene amplification, since the amplification was detected in six (35%) of 17 tumors with p53 mutations and in five (15%) of 33 tumors without p53 mutations. However, eight (73%) of 11 tumors with proto-oncogene amplification harbored p53 mutations or MDM2 amplification. CONCLUSIONS AND IMPLICATIONS: A subset of advanced urothelial cancers without p53 mutations may harbor MDM2 amplification. This finding should be taken into account when adopting p53 alteration as a marker of aggressiveness in urothelial cancers. Although the abrogation of normal p53 function may be one of the key steps to protooncogene amplification, the data further indicate that the predisposition to gene amplification in urothelial cancers was not determined by the presence of p53 alteration alone.

Enhanced expression of interleukin-6 in primary human renal cell carcinomas.

We have demonstrated interleukin-6 (IL-6) production by human renal carcinoma cells. The IL-6 gene expression was detected by Northern blot analysis in 22 of 43 primary renal cell carcinoma tissues and in five of seven renal cell carcinoma cell lines. Immunohistochemical analysis confirmed the expression of IL-6 by the tumor cells. Patients with a high-level expression of IL-6 had significantly greater incidences of lymph node metastasis and a larger increase in serum C-reactive protein than those without it. We have also probed for the presence of IL-6 receptor by Northern blot analysis; we detected this receptor in 11 of the 43 primary renal cell carcinoma tissues but in none of the seven renal cell carcinoma cell lines. However, by use of the complementary DNA-polymerase chain reaction, the IL-6 receptor transcript was detected in all specimens, including the seven cell lines. No expression of the interleukin-3 (IL-3) gene was identified in any of the 43 primary renal cell tumors. These data provide evidence that IL-6 and its receptor may play a role in promoting the transformation and/or proliferation of renal cell carcinomas as well as in teh development of symptoms.

Detection of telomerase activity in exfoliated cells in urine from patients with bladder cancer.

BACKGROUND: Telomeres are specific structures located at the ends of chromosomes that help maintain chromosome stability. In most tissues, telomeres become shorter as cells divide, a phenomenon thought to be associated with limitations on normal cell proliferation. Almost all types of cancer cells, including bladder cancer cells, express the enzyme telomerase, which can maintain or extend telomere length. PURPOSE: We examined telomerase activity in tumor specimens from a cohort of patients with bladder cancer and determined whether telomerase could be detected in exfoliated cancer cells present in urine from these patients. METHODS: Spontaneously voided urine specimens and bladder-washing fluids (obtained by propelling normal saline into the bladder through a catheter and then withdrawing the liquid contents) were taken from 45 patients before they underwent surgery. Telomerase activity was examined by means of the TRAP (telomeric repeat amplification protocol) assay on extracts of tumor samples from 42 patients and extracts of exfoliated cells in urine and bladder-washing fluid from 42 and 43 patients, respectively. Standard cytologic examination (Pap staining) of urine specimens was also used to detect exfoliated cancer cells. RESULTS: Telomerase activity was found in 41 (98%; 95% confidence interval [CI] = 87%-100%) of the 42 tumor samples examined. In contrast, it was not detected in normal bladder tissue from two autopsied individuals who were free of bladder cancer and five of six individuals who had bladder cancer. Telomerase was detected in exfoliated cells in 23 (55%; 95% CI = 39%-70%) of the 42 spontaneously voided urine specimens and in 36 (84%; 95% CI = 69%-93%) of the 43 bladder-washing fluids examined. Considering voided urine specimens and bladder-washing fluids together, telomerase was detected in exfoliated cells from 40 (89%; 95% CI = 76%-96%) of the 45 patients. Telomerase activity was not detected in bladder-washing fluids from 12 cancer-free individuals. Cancer cells were detected by means of standard cytologic examination in the urine of 19 (42%; 95% CI = 28%-58%) of the 45 patients. Urine cytologic examination detected cancer cells in one (8%; 95% CI = 0%-38%) of 12 patients with grade 1 tumors and in 13 (46%; 95% CI = 28%-66%) of 28 patients with grade 2 tumors. In contrast, telomerase activity was detected in exfoliated cells (in voided urine or bladder-washing fluids) from nine (75%; 95% CI = 43%-95%) of 12 patients with grade 1 tumors and from 27 (96%; 95% CI = 82%-100%) of 28 patients with grade 2 tumors. CONCLUSION AND IMPLICATION: Telomerase activity can be detected in exfoliated cells in urine from patients with bladder cancer, and measurement of this activity appears to be more sensitive in detecting the presence of cancer than standard urine cytologic examination. These findings suggest that measuring telomerase activity in exfoliated cells would be useful in the diagnosis and follow-up of patients with bladder cancer, a possibility that warrants further study.

Allelic loss at chromosome 3p characterizes clear cell phenotype of renal cell carcinoma.

Incidence of the loss of heterozygosity on chromosome 3p was evaluated using 7 polymorphic probes in 35 Japanese patients with sporadic renal cell carcinoma (RCC). Overall frequency of the loss of heterozygosity on 3p was 53%, representing 16 of 30 informative cases. Examination of the relationship between histopathological phenotypes of RCC and incidence of the 3p loss revealed that the loss of heterozygosity in clear cell type tumors (75%, 12 of 16) was significantly (P less than 0.01) more frequent than that in granular cell type tumors (14%, 1 of 7). In addition, three mixed cell type tumors, consisting predominantly of granular cell components, showed no loss of chromosome 3p loci. These findings may support the notion that the loss of heterozygosity on chromosome 3p is a nonrandom event in the tumorigenesis of sporadic RCC, and suggest that this type of chromosomal rearrangement is specific to the clear cell phenotype of RCC.

Allelic losses at chromosome 17p in human renal cell carcinoma are inversely related to allelic losses at chromosome 3p.

Recent studies have demonstrated that allelic losses at chromosome 17p are associated with the genesis of a wide variety of human cancers. In order to assess whether the rearrangement of chromosome 17p was responsible for the genesis of renal cell carcinoma (RCC), we used restriction fragment length polymorphism analysis of chromosome 17p. We studied 48 RCCs, including 6 metastatic RCCs, from 43 patients with 5 polymorphic probes to loci within or near the p53 gene. Allelic losses at chromosome 17p were detected in only 6 of the 36 informative cases (17%), and no definitive correlation was demonstrated between allelic losses at 17p and the tumor stages. The 6 RCCs with allelic losses at 17p were histopathologically classified as a clear cell type in one, a mixed cell type in one, and granular cell types in the other four cases. Allelic losses at 17p in the clear cell type of RCC were infrequent (6%, 1 of 18), and were not detected even in the metastatic tumor from a highly advanced case. This finding suggests that allelic losses at 17p could be random genetic rearrangements in the case of the clear cell type of RCC. On the other hand, allelic losses at 17p in the granular cell type of RCC were demonstrated with a significantly higher frequency (44%, 4 of 9). We previously reported that allelic losses at 3p were specific to the clear cell type of RCC (Ogawa et al., Cancer Res., 51:949-953, 1991). Examination of the association of allelic losses at 17p with those at 3p revealed that none of 5 informative RCCs with allelic losses at 17p showed allelic losses at 3p. Conversely, 17 of 25 informative RCCs with retention of 17p alleles lost alleles at 3p. Thus, an inverse relationship was demonstrated with statistical significance (P less than 0.01). These data suggest that the types of rearrangement on chromosome 17p and/or chromosome 3p can differentiate between the histopathological subtypes of RCC.

Enhancement of Fas-mediated apoptosis in renal cell carcinoma cells by adriamycin.

Anti-Fas monoclonal antibody (mAb) kills Fas-expressing cells by apoptosis. Several anticancer agents also mediate apoptosis and may share common intracellular pathways leading to apoptosis with Fas. Thus, we reasoned that combination treatment of drug-resistant cells with anti-Fas mAb and drugs might overcome their resistance. We investigated whether anticancer agents enhance Fas-mediated apoptosis and cytotoxicity against renal cell carcinoma (RCC) cells. Treatment of ACHN RCC cells with anti-Fas mAb in combination with 5-fluorouracil, vinblastine, IFN-alpha, or IFN-gamma did not overcome resistance to these agents. However, combination treatment with anti-Fas mAb and Adriamycin (ADR) resulted in a synergistic cytotoxic effect. Furthermore, synergy was also obtained even when the exposure time was shortened from 24 h to 8 or 2 h. Synergy was also achieved in four other RCC cell lines and five freshly derived human RCC cells. Treatment with anti-Fas mAb in combination with epirubicin or pirarubicin also resulted in a synergistic cytotoxic effect on ACHN cells. Similar results were achieved with a combination of humanized anti-Fas mAb and ADR. Incubation of ACHN cells with ADR augmented the expression of Fas and p53, but not Bcl-2, Bax, or caspase-3. However, the activity of caspase-3 itself was apparently enhanced after treatment with ADR alone or combined treatment with anti-Fas mAb. The synergy obtained in cytotoxicity with anti-Fas mAb and ADR was also achieved in apoptosis. Exposure of ACHN cells and freshly derived RCC cells to ADR enhanced their susceptibility to lysis by peripheral blood lymphocytes and tumor-infiltrating lymphocytes. This study demonstrates that combination treatment of RCC cells with anti-Fas mAb and ADR might overcome their resistance. The sensitization required a low concentration of ADR and a short exposure time, thus supporting the potential in vivo application of a combination of ADR and anti-Fas mAb or immunotherapy in the treatment of ADR- and/or immunotherapy-resistant RCC.

Sensitization of human renal cell carcinoma cells to cis-diamminedichloroplatinum(II) by anti-interleukin 6 monoclonal antibody or anti-interleukin 6 receptor monoclonal antibody.

Cytotoxic chemotherapy has shown little antitumor activity against renal cell carcinoma (RCC). It has been demonstrated that RCC cells secrete interleukin 6 (IL-6) and express IL-6 receptors (IL-6Rs). IL-6 inhibits apoptosis and enhances manganese superoxide dismutase expression. Several anticancer chemotherapeutic agents exert their cytotoxic activity in part through the induction of apoptosis and the production of free radicals. Thus, the resistance of RCC cells to the anticancer agents might correlate with IL-6 expression. The present study tested this hypothesis by examining the effect of anti-IL-6 mAb and anti-IL-6R mAb on the sensitivity of human RCC cells to anticancer chemotherapeutic agents. Treatment of Caki-1 cells with anti-IL-6 mAb or anti-IL-6R mAb in combination with cis-diamminedichloroplatinum(II) (CDDP) or mitomycin C overcame their resistance to CDDP or mitomycin C. However, treatment of Caki-1 cells with anti-IL-6 mAb or anti-IL-6R mAb in combination with Adriamycin, vinblastine or 5-fluorouracil did not overcome their resistance to these anticancer agents. Treatment of CDDP-resistant Caki-1 cells (Caki-1/DDP), two other RCC cell lines (ACHN and A704), and three freshly derived RCC cells with CDDP in combination with anti-IL-6 mAb or anti-IL-6R mAb reversed the resistance to CDDP in all these tumors. We then studied the effectiveness of other platinum derivatives. Treatment of Caki-1 cells with anti-IL-6 mAb or anti-IL-6R mAb enhanced their sensitivity to carboplatin, but not to trans-diamminedichloroplatinum(II). Several experiments investigated the mechanism of the antibody-mediated sensitization of RCC cells to CDDP. Incubation of Caki-1 cells with anti-IL-6 mAb or anti-IL-6R mAb did not change the intracellular accumulation of CDDP. The expressions of the multidrug resistant phenotype (gp170) and c-myc oncogene were not affected by the antibody-mediated sensitization. Treatment of Caki-1 cells with the anti-IL-6 mAb or anti-IL-6R mAb down-regulated the expression of glutathione S-transferase pi mRNA. This study demonstrates that treatment of RCC cells with CDDP in combination with anti-IL-6 mAb or anti-IL-6R mAb can overcome their CDDP-resistance and that the down-regulation of glutathione S-transferase pi expression by anti-IL-6 mAb or anti-IL-6R mAb might play a role in the enhanced cytotoxicity obtained.(ABSTRACT TRUNCATED AT 400 WORDS)

Prostate-specific amplification of expanded polyglutamine expression: a novel approach for cancer gene therapy.

For cancer gene therapy, it is of primary importance to develop a system to sufficiently and selectively express therapeutic genes in cancer cells. In this study, we showed that an approximately 5.3-kb promoter region of the prostate-specific antigen (PSA) gene can replicate the endogenous expression pattern, although its expression is very weak. We then developed a novel two-step transcriptional activation system in which the PSA promoter drives an artificial transcriptional activator, GAL4-VP16 fusion protein, and it in turn activates transgene expressions under the control of GAL4-responsive elements. By using this system, transgene expressions can be greatly augmented while maintaining prostate-specific expression. Finally, we applied this system to drive an expanded polyglutamine, a potent proapoptotic molecule, to induce apoptosis selectively in PSA-positive prostate cancer cells. This novel system would provide an ideal approach for cancer gene therapy applicable not only to prostate cancer but to other cancers as well.

Common regions of deletion on chromosomes 5q, 6q, and 10q in renal cell carcinoma.

Relatively frequent losses of heterozygosity on chromosomes 5q, 6q, and 10q, in addition to loss of heterozygosity on the short arm of chromosome 3, have been observed in renal cell carcinomas. As the first step toward isolation of tumor suppressor genes on these three chromosomal arms, we used six restriction fragment length polymorphism markers for 5q, nine for 6q, and eight for 10q to identify regions commonly deleted in a panel of 64 renal cell carcinomas. Allelic losses were common at chromosome 5q21, the region where the MCC (mutated in colorectal cancer) gene was recently identified; at chromosome 6q27; and at chromosome 10q21-23. Furthermore, as association was observed between accumulation of allelic losses on these three chromosomal arms and progression of tumors. Loss of heterozygosity on chromosome 5 showed a correlation with the histopathological grade of a given tumor and the incidence of distant metastasis.

Dietary beta-carotene and cancer of the prostate: a case-control study in Kyoto, Japan.

One hundred patients with prostate cancer and two different control series [100 benign prostatic hyperplasia (BPH) patients and 100 general hospital patients] were matched to each other upon hospital admittance, age (+/- 3 years) and date of admission (+/- 3 months), and directly interviewed during admission from 1981 to 1984 in Kyoto, Japan. Major dietary findings derived from a quantitative food frequency technique for estimating usual diet are as follows. (a) The smaller the dietary intake of beta-carotene and vitamin A as well, the higher the risk, with a highly significant linear trend. From the beta-carotene analyses, the relative risk (95% confidence interval) for the lowest intake quartile relative to the highest was 2.10 (0.98-4.47) for the uncorrected intake, 2.35 (1.08-5.12) for the intake per kg, and 2.94 (1.34-6.44) for the intake per kcal in the comparison with BPH patients; 2.88 (1.31-6.32), 2.56 (1.14-5.76), and 3.50 (1.52-8.06), respectively, in the comparison with hospital controls. The corresponding relative risk obtained from the vitamin A analyses was 2.82 (1.30-6.14), 2.64 (1.24-5.60), and 3.29 (1.47-7.35) in due order in the comparison with BPH patients; 2.69 (1.22-5.94), 4.78 (1.98-11.52), and 3.50 (1.52-8.06) in the comparison with hospital controls. (b) beta-Carotene as well as vitamin A contained in green/yellow vegetables were significantly protective, and those in seaweeds and kelp suggestively protective. But those in fruits appeared to enhance the risk. (c) The risk reduction by dietary beta-carotene and vitamin A was significant in the older men (70-79 years), but not in the younger men (50-69 years). (d) Total energy intake and the dietary intake of fat, protein, carbohydrate, water, fiber, ash, such vitamins as retinol, B1, B2, C, and niacin, and such minerals as calcium, potassium, sodium, phosphorus, and iron were not linked with prostate cancer risk. (e) A protective effect of dietary beta-carotene and vitamin A against prostate cancer could be related to the low overall fat intake in Japan.

HLA-DRB1*0101 and *0405 as protective alleles in Japanese patients with renal cell carcinoma.

A variety of malignancies have been linked to major histocompatibility complex genes, including the DRB1 alleles. The association of certain DRB1 antigens with renal cell carcinoma (RCC) has been both claimed and disclaimed. To determine whether HLA-DRB1 genotypes are associated with RCC, we used the modified PCR-RFLP method for the high-resolution HLA-DRB1 genotyping of 96 Japanese RCC patients. There were no significantly frequent HLA-DRB1 alleles, whereas the DRB1*0101 and *0405 alleles had significantly lower frequencies [P = 0.004, relative risk (RR) = 0.2 and P = 0.002, RR = 0.4) in the RCC patients than in the healthy Japanese controls (n = 1216). Moreover, patients with the HLA-DRB1 *0101 or *0405 allele tended to be in earlier stages and to have less aggressive tumors than patients with neither of these alleles. The corresponding serotyping subclassification, however, showed a significantly lower frequency only for DRB1-DR1 (P = 0.01, RR = 0.3). High-resolution genotyping is essential because the polymorphism of the peptide-binding domain of major histocompatibility complex class II molecules is more precisely determined by genotypes than serotypes. In addition, inherent technical difficulties and potential typing errors render serotyping inefficient. Our data suggest that HLA-DRB1*0101 and *0405 are protective alleles for both RCC development and tumor progression.

Abnormal bone marrow B-cell differentiation in pre-B lymphoma-prone SL/Kh mice.

SL/Kh mice spontaneously develop pre-B lymphomas with surface phenotypes of B220+, BP-1+, Thy-1-, and surface immunoglobulin negative. The immunoglobulin heavy chain of lymphoma is clonally rearranged but the light chain gene remains in germline configuration. Studying prelymphoma stage SL/Kh bone marrow (BM), we found unusual multiclonal expansion of BP-1+ pre-B cells [34.8 +/- 5.8% (mean +/- SD)] by 4 weeks of age, whereas there were far fewer of such cells in most other laboratory strains (8 +/- 5%). The BP-1+ cells did not express surface immunoglobulin, Thy-1.1, or c-kit. Therefore, they seemed to belong to the pre-B II category. Increased numbers of BP-1+ cells were seen in F1 hybrids between SL/Kh and NFS/N; thus it was apparently a dominant heritable property of SL/Kh mice. Emergence of this population was independent of expression of endogenous ecotropic virus, since they were present in BMs of the F1 hybrid to C4W (Fv-4') and were not inhibited by neonatal injection of maternal resistance factor. In the radiation chimeras SL/Kh-->BALB/c, BP-1+ cells appeared abundantly (29.0 +/- 3.8%), whereas in the reciprocal chimeras BALB/c-->SL/Kh, for fewer (5.5 +/- 2.3%) appeared. Therefore, expansion of BP-1+ cells in prelymphomatous BM is a property of SL/Kh stem cells rather than BM microenvironments.