Trends in frequency of latent prostate carcinoma in Japan from 1965-1979 to 1982-1986.

By analyzing serial step-sections of whole prostate obtained at autopsy, we determined the chronologic change of the frequency of latent prostate tumor in Japan in two periods: 1965-1979 and 1982-1986. Methods of specimen preparation and examination were identical for both periods. The frequency with which latent prostate carcinoma was found in the 660 samples for 1982-1986 was 34.6% and was significantly higher than the 22.5% seen in the 576 observed for 1965-1979 (P less than .0001). This significant finding can be attributed to an increase in the frequency of latent infiltrative tumor (LIT). However, the increase in the frequency of noninfiltrative tumor (LNT) was less significant (P = .045). Both sets of specimens were subsequently combined and reanalyzed according to the year of birth of the decedents. The LIT has progressively increased in frequency in each age-specific category. By morphometry, we determined that the mean tumor volume decreased due to an increase in the number of smaller tumors during the study periods. Although the frequency of latent prostate carcinoma and the LIT:LNT in the samples obtained most recently were comparable to those of U.S. whites, cancer incidence and mortality rates remain lower in Japan. Apparently, the initial step in the induction of prostate carcinoma in indigenous Japanese is now similar to that in U.S. whites. The rates of clinical carcinoma in Japan are still low when compared with those in the United States and countries in Western Europe, but our findings may presage a time when these differences may be greatly reduced or nonexistent.

Presence of ras oncogene mutations and human papillomavirus DNA in human prostate carcinomas.

The frequency of H-ras, K-ras, and N-ras mutations and the presence of high-risk human papillomavirus (HPV 16, 18, and 33) DNA were studied in 75 paraffin-embedded specimens obtained from 68 Japanese patients with a variety of prostate carcinomas by using polymerase chain reaction and DNA hybridization with sequence-specific oligonucleotides. Ten specimens each of normal and benign hyperplastic prostatic tissues from the same number of patients were also examined for this analysis. Of 68 carcinoma cases, ras gene mutations were present in 16 cases (24%) and HPV DNAs in 28 cases (41%). Eleven mutations were detected in codon 61 of H-ras, 4 in codon 12 of N-ras, and 2 in codon 61 of K-ras. HPV 16, 18, and 33 DNAs were found in 11, 17, and 5 cases, respectively. Eight of the 16 cases with ras mutation also harbored HPV DNAs. The frequency of ras mutations and the HPV infection increased in patients with advanced stages of the tumor and with the higher Gleason score. There was the predominant presence of H-ras codon 61.2 (CAG-->CTG) mutation and HPV 18 DNA in prostatic carcinomas metastasizing to the bone. None of the normal or benign hyperplastic prostatic specimens contained either ras mutation or HPV DNA. Our results suggest that ras gene mutations and HPV infections are relatively frequent, at least in prostate carcinoma of Japanese patients. These two factors appear to be related to the progression of the tumor. Moreover, H-ras codon 61.2 mutation and HPV 18 infection may have some predictive roles for bone metastasis in prostate carcinoma.

Mutation, allelotyping, and transcription analyses of the p73 gene in prostatic carcinoma.

A novel gene, p73, encoding a protein with significant homology to p53, was recently identified at 1p36. To investigate penetrance of p73 in prostatic carcinogenesis, mutation, allelotyping, and transcription analyses of p73 were performed in prostatic carcinoma. No types of mutation causing amino acid substitutions or frameshifts were found in 106 cases examined. Loss of heterozygosity in the gene was found in 2 of 38 cases (5.3%). Various expression levels of p73 alpha variant were observed in tumor compared with those in normal tissue. These data suggest that the p73 gene is not playing an essential role, but expression of p73 may associate with tumor growth in prostatic carcinogenesis.

Tenascin expression and postnatal development of the human prostate.

We investigated the distribution of tenascin during postnatal development of the human prostate. Monoclonal antibody specific to human tenascin was applied to paraffin sections by the avidin-biotin-complex method to examine its localization. Infantile prostates showed two distinct zones. The inner zone had sparse acini with fibromuscular bundles. The peripheral zone had similar acini and lighter stroma as compared with inner zone. Tenascin was found diffusely but weakly. The periglandular area occasionally showed immunoreactivity. The prostates from 9- to 13-year-old subjects had a morphology similar to that of the infantile gland. The difference was increased density of the acini. Immunoreactivity was low. In the prostates from 14- to 21-year-old subjects, the acini distribution was more crowded, and the epithelial lining had become taller in both zones. Tenascin distributed preferentially in the peripheral zone during this period. Simultaneously, the percent of glandular area in the peripheral zone rose abruptly. The dynamics of tenascin expression are closely associated with the development and maturation of the gland. The distribution of tenascin during the post-puberal period may suggest its participation in the preferential of prostatic carcinoma in the peripheral zone.

Isolation and characterization of human fibroblast tenascin. An extracellular matrix glycoprotein of interest for developmental studies.

We have developed a biochemical method for purifying human tenascin from cultured fibroblasts or the culture medium. The method is a series of biochemical procedures including gel filtration, gelatin gel affinity chromatography and ion-exchange high performance liquid chromatography. The final preparation was identified as tenascin from its immunological cross-reactivity to antibody against chicken tenascin, strong hemagglutination activity which has been reported to be one of the biological functions of chicken tenascin, and from the electron microscopic study demonstrating a six-armed structure. Gel chromatography showed that intact human tenascin has an apparent molecular weight of over one million. Analysis of the purified tenascin with SDS-PAGE under reducing conditions demonstrated that tenascin consists of two kinds of subunits (250K and 190K). We established rat x mouse heterohybridoma cell lines which produce tenascin-specific antibodies. One monoclonal antibody (RCB1) was selected for immunohistochemical study and partially characterized. RCB1 bound native tenascin but not reduced and alkylated tenascin. Immunohistochemistry of normal and neoplastic tissues demonstrated that RCB1 bound the connective tissues surrounding the cancer nests and various normal tissues including interstitium of renal distal tubule, periosteum, endosteum, smooth muscles of digestive tract and media of arteries and arterioles.

A prospective comparison of prostate cancer at autopsy and as a clinical event: the Hawaii Japanese experience.

Prostate cancer was diagnosed in life among 274 of 8006 (3.6%) members of a cohort of Japanese men in Hawaii between 1965 and 1990. Only 55 (20%) of the 274 diagnosed cases died with prostate cancer, and they accounted for only 2% of the 2893 deaths that occurred among the men during this period. None of the 61 men whose tumor was found incidentally to a transurethral resection died as a result of this cancer, while it was the cause of death of 9 of 106 (8%) men with clinical cancer localized to the prostate. Forty-six of the 107 (43%) men with more extensive disease at the time of diagnosis died from prostate cancer. Step sectioning of the prostate identified prostate cancer in 80 of 293 (27%) autopsied Hawaii Japanese men who died after 50 years of age, reaching a frequency of 63% (10 of 16) among men over 80 years of age. The volume of 48 (60%) of these cancers was less than 150 mm3. These small tumors would probably not have been discovered in a screening program. Tumors larger than 1000 mm3 would probably be discovered using modern diagnostic procedures but were found in only 13 (4.4%) of the autopsied men. It is likely that a screening program to detect and treat such large, unsuspected tumors in this population would have had little impact upon the already low proportion of deaths due to prostate cancer among these Japanese men.

Histochemical examination of expression of ras p21 protein and R 1881-binding protein in human prostatic cancers.

Expression of ras p21 was examined with monoclonal antibody RASK-3 in normal, benign hyperplasic, and cancerous prostates. In patients with stage D2 disease who received endocrine therapy, the relation between ras p21 expression, response to therapy, and prognosis was studied. In these patients, R 1881-binding protein (androgen receptor and progestin-binding protein) was also examined. Non-cancerous cells and most cancer cells from stage A patients did not express ras p21, while expression increased with both higher staging and grading. Staging pelvic lymphadenectomy was done in some stage A2-C cases, and presence of nodal metastasis was correlated with ras p21 expressions in the primary tumours. In stage D2, there was no correlation between ras p21 expression and R 1881-binding protein. Response to therapy and survival did not correlate with expression of ras p21, but was influenced by presence of R 1881-binding protein.

Mucous gland metaplasia of the prostate.

Mucous gland metaplasia of the prostate was observed in 11 of the 1,236 autopsy cases. The cells were characterized by plump cytoplasmic mucin and tiny nuclei that were basally oriented. They resembled Cowper's gland (bulbourethral gland) epithelium. The lesion was located randomly within the glands and was very small; only one was larger than 1 mm2. The cytoplasmic mucin was periodic-acid Schiff positive and immunohistochemically negative for prostate-specific antigen. Lectin binding profiles were different from those of normal prostatic glandular epithelium and also from those of Cowper's gland. The importance of recognizing mucous metaplasia lies in its differentiation from other lesions, especially from low-grade carcinoma.

Establishment and characterization of a second primary osteosarcoma cell line (OSrb/N-M) from a patient cured of bilateral retinoblastoma.

A cell line, designated OSrb/N-M, was established from the second primary osteosarcoma that developed in a 17-year-old Japanese female patient who had suffered from bilateral retinoblastoma at infancy. The OSrb/N-M cells grew as an adherent monolayer and retained some osteogenic biochemical phenotypes. In cytogenetic analyses, this cell line revealed many structural and numerical abnormalities, however, the bands q14 of both chromosomes 13 appeared to be normal, whereas the constitutional cells displayed normal female karyotypes. Immunoblot studies using monoclonal antibodies specific to RB protein demonstrated that the tumor cells did not express RB protein, suggesting that the OSrb/N-M cells might suffer from a loss-of-function mutation at this gene locus. Thus, this cell line is useful to study the molecular mechanism for the tumorigenesis of osteosarcoma with regard to an association with retinoblastoma.

Demonstration of MDR1 P-glycoprotein isoform expression in benign and malignant human prostate cells by isoform-specific monoclonal antibodies.

Prostate cancers are resistant to many anticancer agents at the time of presentation. P-glycoprotein (P-gp) is believed to mediate multidrug resistance phenotype. To elucidate the possible role of P-gp in such an intrinsic drug resistance of prostate cancers, its expression was examined immunohisochemically using two P-gp isoform-specific monoclonal antibodies (mAbs) with the paraffin embedded prostate samples derived from five nonmalignant and 30 untreated prostate cancer patients. In all of five normal prostate tissues, P-gp was consistently detected with both mAbs in the epithelial cells, especially at their apical site, and the level of expression was higher in the inner zone than in outer zone. On the other hand, tumor cells expressed P-gp heterogeneously in distribution and intensity; in 25 of 30 malignant cases P-gp expression was clearly demonstrated, whereas its expression was only faintly detected in other cases. However, the staining intensities for P-gp in prostate cancer cells were generally lower than in normal prostate epithelial cells. Thus, not only normal prostate epithelial cells but prostate cancer cells express at least MDR1 P-gp isoform. These results suggest that P-gp expression might play some role in intrinsic drug resistance of prostate cancer cells to many cytotoxic drugs as well as in relative resistance of the inner zone cells to the prostate carcinogenesis.

Progression-linked overexpression of c-Met in prostatic intraepithelial neoplasia and latent as well as clinical prostate cancers.

The c-met proto-oncogene encoding the receptor for the hepatocyte growth factor is expressed in several cancers. In the present study, c-met protein (c-Met) was detected in eight of 22 (36%) cases of prostatic intraepithelial neoplasia (PIN), five of 15 (33%) latent and 17 of 21 (81%) clinical prostate cancers, including seven metastatic lesions, using an immunohistochemical method. All seven (100%) metastatic lesions investigated demonstrated strong staining, and a correlation between c-Met expression and histology was observed. These results suggest a significant relationship between c-Met expression and progression of prostate neoplasms, including latent cancers.

Genetic polymorphisms in cytochrome P450 (CYP) 1A1, CYP1A2, CYP2E1, glutathione S-transferase (GST) M1 and GSTT1 and susceptibility to prostate cancer in the Japanese population.

Associations between genetic polymorphisms of CYP1A1, CYP1A2, CYP2E1, GSTM1 and GSTT1 and prostate cancer (PCa) were analyzed in a case-control study of 315 individuals. The frequency of valine (Val)/valine (Val) genotypes for CYP1A1 was 11.3% in cases compared with 5.5% in controls, this polymorphism thus being associated with a significantly increased risk of PCa (odds ratio=2.4, 95% confidence interval (CI)=1.01-5.57). No links were detected between PCa and polymorphisms in other enzymes. However, the combination of CYP1A1 (Ile/Val and/or Val/Val) polymorphisms with the GSTM1 null type resulted in an OR of 2.2 (CI=1.10-4.57, 1.12-4.20, respectively). This study suggests that the CYP1A1 polymorphism and its combination with GSTM1 may be associated with PCa susceptibility in the Japanese population.

N-acetyltransferase 1 genetic polymorphism influences the risk of prostate cancer development.

The potential involvement of N-acetyltransferase 1 (NAT1) genetic polymorphisms in prostate cancer (PCa) patients was analyzed in 101 patients with PCa and 97 controls with no incidental malignancy. Identification of NAT1*10, the variant allele associated with the rapid acetylator phenotype was by allele-specific polymerase chain reaction (PCR). When the NAT1*10 heterozygote and other genotypes without NAT1*10 allele were considered as low risk genotypes, NAT1*10/NAT1*10 had a significantly higher risk of PCa (OR = 2.4, 95% CI; 1.0-5.6). If our preliminary results can be confirmed in a larger population, it may be a useful marker for PCa risk.

Detection of RB, p16/CDKN2 and p15(INK4B) gene alterations with immunohistochemical studies in human prostate carcinomas.

To examine the status of cell cycle-inhibitory genes in human prostate carcinoma, we investigated alterations of RE (retinoblastoma), p16/CDKN2 and p15(INK4B) genes in 32 adenocarcinomas with immunohistochemistry. PCR-single-strand conformation polymorphism (SSCP) was used to examine all 27 exons of the RE gene, exons 1 to 3 of the p16/CDKN2 gene and exons 1 and 2 of the p15(INK4B) gene for mutations. Loss of heterozygosity (LOH) for the RE gene was probed by restriction fragment length polymorphism (RFLP) analysis. In addition, coordinate samples were subjected to immunohistochemical studies for reactivity to RE and p16 protein. The RE gene alterations were detected in 5 of the 32 tumors (16%); of these, only one mutation, a missense substitution, occurred within an exon. The remaining four single base insertions or deletions were found within introns of the RE gene and no mutational event was detected in its promoter region. LOH involving intron 17 of RB was detected in three cases of 10 informative tumors (30%). Intragenic mutations were also present in 3 of the 32 tumors in the p16/CDKN2 gene. In contrast, no mutational events were found in the p15(INK4B) gene in the tumors. Only one tumor had both a p16/CDKN2 mutation and LOH of the RE gene. Expression of pRB was absent or reduced in 16 cancers, while p16 expression was present in all cases to varying degrees. The results suggest that p16/CDKN2 gene mutations occur rarely and intragenic mutation, but not LOH,of the RE gene is not required in prostatic tumorigenesis.

Ectopic thyroid in the adrenal gland.

We report two cases of intraadrenal thyroid gland tissue, both found by abdominal computed tomography (CT) scan and ultrasound echography. Histologically, the lesions were composed of mature thyroid follicles, varying in size, and some with cystic dilatation. Immunohistochemical staining for thyroglobulin confirmed their thyroid follicular nature. In neither case was there any evidence of thyroid gland cancer or teratomatous elements. Clinical examinations, including CT, ultrasound echography, and scintscanning did not show any tumorous lesions in the thyroid gland or elsewhere. The cause of ectopic thyroid in the adrenal gland is not known. It seems difficult to explain these ectopic lesions on the basis of developmental error because their location is distant from the path of embryological descent of the thyroid. The most important practical consideration is that they must be distinguished from metastatic deposits from a clinical point of view.

Rare chromosomal aberrations induced by vincristine. Partial endoreduplication and pseudoendoreduplication, segmentally endoreduplicated chromosomes, and segmental premature chromosome condensation.

Vincristine (VCR) is capable of inducing a cell containing both conventional chromosomes (monochromosomes) and diplochromosomes. A total of 124 such metaphases were examined by 5-bromodeoxyuridine (BrdU) incorporation and fluorescence plus Giemsa (FPG) technique to analyze cell cycle kinetics. The majority of cells (119 metaphases) showed differential BrdU incorporation between the two kinds of chromosomes, indicating that partial endoreduplication occurred in these cells. In addition, existence of partially endoreduplicated cells with premature chromosome condensation (PCC) in either mono- or diplochromosomes suggests that the timing of monochromosome-replication was very variable in individual cells. On the other hand, the remaining five metaphases showed that both mono- and diplochromosomes incorporated BrdU similarly, indicating that diplochromosomes are formed by pseudoendoreduplication. Two kinds of chromosomal aberrations probably caused by delay of DNA synthesis on chromosome segments, segmental endoreduplication, and segmental PCC were also reported. Segmental endoreduplication was defined as endoreduplication that occurred on some segments of chromosomes. Out of 119 partially endoreduplicated cells, 3 contained a chromosome consisting of both mono- and diplochromosomal segments, indicating that the former segments missed one round of DNA synthesis. Segmental PCC was defined as PCC restricted to only some segments of chromosomes. Two types of segmental PCC, segmental S-PCC and G2-PCC, were observed in VCR-induced ordinary polyploidy. Although both segmental endoreduplication and segmental PCC occurred with very low frequency, these phenomena suggest that DNA synthesis was disturbed in some part of the nucleus.

Combined analysis of expression of c-erbB-2, Ki-67 antigen, and tenascin provides a better prognostic indicator of carcinoma of the papilla of Vater.

Expression of the molecular biological factors (MBFs) c-erbB-2, Ki-67 antigen, and tenascin (TN) was assessed immunohistochemically in specimens from patients who had undergone surgery for carcinoma of the papilla of Vater. The MBFs were then analyzed by histological factors (v, d, panc, n, Stage), which have been demonstrated to be outcome predictors, and by patient outcome. None of the MBFs showed any significant correlation with the histological factors. There were significant differences (p < 0.05) in the expression of c-erbB-2, Ki-67 antigen, and TN between patients who survived >5 years and those who survived <5 years. The patients with greater expression of c-erbB-2, Ki-67 antigen, and TN had a poor prognosis, whereas those with less expression had a good prognosis. They were therefore considered independent predictors of outcome for carcinoma of the papilla of Vater. Combined analysis of both histological factors and MBFs was also performed, with the result that the combined analysis of MBFs yielded a better prediction of outcome in carcinoma of the papilla of Vater than analysis of either one histological factor or MBF.

Primary adenosquamous carcinoma of liver resected by right trisegmentectomy: report of a case and review of the literature.

A case of primary adenosquamous carcinoma of the liver in a patient with an elevated level of serum squamous cell carcinoma-related antigen is reported. A 68-year-old man was admitted to our hospital with a 10-day history of fever and jaundice. From the results of laboratory and imaging studies before surgery, a diagnosis of cholangiocellular carcinoma was made, and the patient underwent right trisegmentectomy with regional lymph node dissection. Histopathological examination of the resected specimen revealed adenocarcinoma, squamous cell carcinoma, and a transitional area containing both types of cancer cells. The number of argyrophilic nucleolar organizer regions and the labeling index of proliferating cell nuclear antigen were markedly elevated and the deoxyribonucleic acid ploidy pattern was aneuploid in the squamous component. The patient died due to liver metastases 3 months after the operation. We reviewed the 31 cases of adenosquamous carcinoma of the liver reported in the Japanese and English language literature, including the present case.

Significance of vitamin D receptor gene polymorphism for prostate cancer risk in Japanese.

Vitamin D receptor gene (VDR) polymorphisms have been reported to be related to prostate cancer risk in the USA. We analyzed the distribution of TaqI RFLP and poly(A) of VDR in 100 prostate cancer patients and 202 urological controls. Among the control, 79.2% were homozygous (TT) for the absence of a TaqI RFLP, while 17.8% were heterozygous (Tt) and 3.0% homozygous (tt) for its presence. The distribution was almost the same in the cancer group; 80% were homozygous TT, 18% heterozygous Tt, and 2.0% homozygous tt. Polymorphism of poly(A) sizes was categorized as a long allele (> or = 18 As) and a short allele (< 18 As). The distribution did not vary between the cancer and control groups; 80, 79.2% were LL, 18, 17.8% LS and 2.0, 3.0% SS, respectively. These results showed no significant association of two VDR polymorphisms with prostate cancer risk, however a different distribution of VDR polymorphisms between Japanese and non-Japanese men.

Mutations of ras genes are relatively frequent in Japanese prostate cancers: pointing to genetic differences between populations.

Point mutations of the ras gene family are thought to be involved in the development of a variety of human tumors. However, it remains unknown whether the ras gene might play a key role in prostate carcinogenesis. We therefore analysed Ki-,N- and H-ras gene mutations in a series of 81 Japanese prostate cancers using PCR-SSCP analysis and Mutant-Allele-Specific Amplification (MASA) method. Mutated as genes were detected in 20 of the 81 samples (24%); three of 22 latent, one of five stage B, four of 14 stage C and 12 of 40 stage D cancers. Of the twenty as gene mutations, 13 were in Ki-ras (codon 12), five in H-ras codon 61 and two H-ras codon 13. The observed frequency of ras gene mutations was higher than that reported in the literature for some non-Japanese prostate cancers, suggesting the possibility of genetic differences between populations.