Fine-scale deletion mapping of the distal long arm of chromosome 6 in 70 human ovarian cancers.

To define a small region on chromosome 6q containing a putative tumor suppressor gene for ovarian cancer, we examined loss of heterozygosity in 70 ovarian tumors of three histological types with nine restriction fragment length polymorphism markers located at 6q24-27. Among 33 cancers of serous type that were informative at one or more loci, 17 showed allelic loss at a few or all loci examined, whereas only 1 of 15 mucinous-type tumors and 2 of 12 clear-cell tumors revealed loss of heterozygosity. This result supported our earlier suggestion that alteration of a gene on chromosome 6q may play an important role during development of serous ovarian tumors (Sato et al., Cancer Res., 51: 5118-5122, 1991). Frequent losses were observed between loci defined by CI6-119 (D6S195) at 6q26 and CI6-49 (D6S161) at 6q27. A detailed deletion map indicated a commonly deleted region between loci defined by CI6-111 (D6S193) and CI6-24 (D6S149); these two markers are estimated to be 1.9 cM apart on the basis of linkage analysis. Our results further define a region containing a tumor suppressor gene involved in ovarian carcinoma within an approximately 2-megabase-long segment of chromosome 6q.

Allelotype of human ovarian cancer.

In order to determine which chromosome(s) carries a tumor suppressor gene(s) for human ovarian cancer, we examined loss of heterozygosity in 37 tumors with a set of polymorphic DNA markers which cover each autosomal chromosome arm partially. Frequent losses were observed in chromosomes 4p (42%), 6p (50%), 7p (43%), 8q (31%), 12p (38%), 12q (33%), 16p (33%), 16q (38%), 17p (46%), 17q (39%), and 19p (34%). In addition to these chromosomes, frequent losses of alleles on chromosomes 6q, 13q, and 19q were observed uniquely in serous and serous papillary cystadenocarcinomas; loss of heterozygosity was detected only rarely on these chromosomal arms in nonserous types of tumors. The average (0.12) of fractional allelic loss seen in mucinous cystadenocarcinoma, which usually has a better prognosis than other types, was much lower than that of other tumor phenotypes including serous cystadenocarcinoma (0.31) and clear cell carcinoma (0.20). These results suggested that (a) a large number of tumor suppressor genes might play a role in ovarian cancer, (b) losses of alleles in different chromosomal regions could account for differences in histopathological features and/or prognoses among patients, and (c) this kind of analysis can contribute to an improved understanding of tumor development and/or progression in human ovarian cancer.

Detailed deletion mapping of chromosome 17q in ovarian and breast cancers: 2-cM region on 17q21.3 often and commonly deleted in tumors.

Using 11 restriction fragment length polymorphism markers, we examined loss of heterozygosity on the long arm of chromosome 17, where one or more genes responsible for hereditary breast and ovarian cancers may be present, in sporadic forms of 94 ovarian and 246 breast cancers. Loss of heterozygosity was observed in 33 of 84 (39.3%) ovarian and in 88 of 214 (41.1%) breast cancers that were informative with at least one marker. Detailed deletion mapping of chromosome 17q in these cancers identified two distinct, commonly deleted regions. One was located between 17q12 and 17q21.3 and the other between 17q25.1 and 17q25.3. In breast cancers, the proximal commonly deleted region was between two loci defined by markers CI17-701 and CI17-730 at 17q21.3, which are 2.4 cM apart. This segment overlaps the region that includes the putative gene for hereditary breast and ovarian carcinomas. The results suggest that at least two tumor suppressor genes associated with sporadic ovarian and breast cancers are present on chromosome 17q and that one of them may be the same gene that is responsible for the hereditary form.

Developmental anatomy of seedlings of Indodalzellia gracilis (Podostemaceae).

In Tristichoideae, aquatic angiosperms in the family Podostemaceae, Terniopsis, Tristicha, Indotristicha and Cussetia have creeping roots with flanking (sub)cylindrical shoots, while Dalzellia is rootless and has crustose shoots. Indodalzellia gracilis, sister to a clade of Dalzellia zeylanica and Indotristicha ramosissima, has subcrustose shoots on the side of creeping roots, suggesting that I. gracilis may be a key species to reveal how saltational evolution of the body plan occurred in these three species. We investigated developmental morphology of I. gracilis seedlings grown in culture, using scanning electron microscopy and semi-thin serial sections. As in D. zeylanica, the plumular apical meristem in the seedling gives rise to two shoot apical meristems, which develop into horizontal subcrustose shoots with dorsal and marginal leaves. Neither radicle nor adventitious root is produced from the hypocotyl, but an adventitious root arises endogenously from the juvenile shoot and from some shoots of adult plants. These results, together with the phylogenetic relationships, suggest that the Indodalzellia seedling evolved by loss of the adventitious root derived from the hypocotyl, appearance of shoots in the axil of cotyledons, and appearance of adventitious roots from adventitious shoots. The difference in place of origin of the root between Indodalzellia and I. ramosissima suggests differing evolutionary origin of the root in Tristichoideae.

Both episomal and integrated forms of human papillomavirus type 16 are involved in invasive cervical cancers.

The form of human papillomavirus type 16 (HPV 16)DNA in specimens of invasive cervical cancer was investigated. High molecular, tandem repeats of viral sequences were detected as several distinct bands, using a low concentration (0.5%) agarose gel and a no-cut enzyme (HindIII) for HPV 16. Two-dimensional agarose gel electrophoresis allowed us to differentiate between the episomal multimeric and the integrated forms of viral DNA. All 34 cervical cancer specimens showed the characteristic PstI cleavage pattern of HPV 16 DNA, indicating that a full viral genome was present in these specimens, and 24 specimens (70%) showed only episomal monomeric or multimeric forms without the integrated form of HPV 16 DNA. The remaining 10 specimens (30%) showed integrated multimeric forms of viral DNA, either without the episomal form (8 specimens) or with the concomitant episomal form (2 specimens). In addition, a metastatic tumor in a pelvic lymph node showed only the episomal form of viral DNA, whereas its primary cervical cancer showed both episomal and integrated forms of viral DNA. There was no correlation between the forms of viral DNA and the clinical stages of tumors. The result indicates that both episomal and integrated forms of a complete HPV 16 DNA are involved in invasive cervical cancers.

Pathogenesis of acute radiation effects in the urinary bladder. Experimental results.

PURPOSE: The present review summarizes experimental studies of the pathogenesis of acute radiation-induced changes in urinary bladder function. MATERIAL AND METHODS: Transurethral cystometry was used for longitudinal assessment of bladder function in mice. With this technique, radiation-induced changes in storage capacity can be quantified. In histological studies, changes in urothelial cell density and in urothelial protein expression during the acute radiation response were determined. Acetylsalicylic acid (ASA) was used for the treatment of acute functional changes. RESULTS: The histological studies did not reveal any systematic fluctuations in urothelial cell density during the time of the acute radiation response. However, characteristic changes in the expression of proteins associated with urothelial cell function, differentiation and cell contact were observed, which correlated with the functional impairment. By local or systematical application of ASA, a significant restoration of bladder function compared to placebo treatment could be achieved. CONCLUSION: Acute functional radiation effects in the urinary bladder are not based on urothelial denudation. However, changes in protein expression indicate an impairment of the urothelial barrier function. The results of ASA treatment demonstrate that prostaglandins are involved in the response. Alterations in urothelial or endothelial prostaglandin metabolism may be primarily radiation-induced or secondary because of the impaired urothelial barrier.

Microsatellite instability in endometrial carcinomas: frequent replication errors in tumors of early onset and/or of poorly differentiated type.

Endometrial and ovarian carcinomas are common among women belonging to hereditary nonpolyposis colorectal carcinoma (HNPCC) families; tumors developing in them are characterized by genetic instability due to an inherited dysfunction of the DNA-mismatch-repair system. To clarify the role of similar genetic factors in sporadic forms of gynecological tumors, we examined 77 endometrial and 68 ovarian carcinomas for replication error (RER) at five microsatellite loci. RER-positive phenotypes at two or more microsatellite loci were observed in 18 of the endometrial carcinomas, but in only two of the ovarian carcinomas. Among the patients with endometrial carcinomas, the frequency of RER tended to be higher in those under age 50 than in those over age 60. Furthermore, RER was significantly more frequent in poorly differentiated than in well-differentiated tumors (P = 0.008, Fisher's exact test). These data suggest that genetic factors characterized by RER are likely to play an important role in some endometrial carcinomas, particularly those of early onset and/or of the poorly differentiated type.

Human papillomavirus type 18 DNA sequences in adenocarcinoma and adenosquamous carcinoma of the uterine cervix.

Human papillomavirus (HPV) DNA sequences were detected by Southern blot hybridization and polymerase chain reaction (PCR) in 10 out of 19 patients (52.7%) with adenocarcinoma [15] and adenosquamous [4] carcinoma of the uterine cervix. HPV 18 DNA was detected in 8 of these 19 patients (42.1%), HPV 16 DNA in 1 patient (5.3%) and HPV type X (unknown) in another (5.3%). Of the 10 HPV positive samples HPV 18 was found in 6 out of 6 pure adenocarcinomas (100%), and in 2 of 4 (50%) adenosquamous carcinomas. HPV 16 and HPV X were each detected in 1 out of 4 (25%) adenosquamous carcinomas. The physical state of the viral DNA was investigated in 5 of the 10 HPV-positive cases. All the specimens from these 5 cases showed HPV to be integrated into the host genome, except for one adenosquamous specimen, which showed both episomal and integrated forms of HPV 16. Six of 8 HPV 18 DNA positive specimens were from cases of pure adenocarcinoma and it was found by PCR that five of these 6 specimens retained fragments of E6/E7, LCR/E7 and early sequence of E1 fragment (sequence: 1188-1373) but deleted most part of E1.

Allelotype of uterine cancer by analysis of RFLP and microsatellite polymorphisms: frequent loss of heterozygosity on chromosome arms 3p, 9q, 10q, and 17p.

Cancers in which mutations have been identified in putative tumor suppressor genes, such as the TP53 gene, the retinoblastoma (RBI) gene, the adenomatous polyposis coli (APC) gene, and the Wilms tumor (WTI) gene, frequently show loss of the corresponding allele on the homologous chromosome. To identify locations of tumor suppressor genes involved in uterine cancer, we examined loss of heterozygosity (LOH) by using genomic probes detecting RFLPs in 35 uterine cancers at 29 loci throughout the genome, and with highly informative microsatellite markers in 21 uterine cancers at nine putative or known tumor suppressor gene loci. High frequencies of allelic loss found at loci on 3p (71%), 9q (38%), 10q (35%), and 17p (35%) suggest that tumor suppressor genes involved in uterine carcinogenesis exist in these regions. There were no significant differences in frequencies of LOH between cancers of the uterine cervix and cancers of the uterine endometrium at any of the loci tested.

Mutational analysis of mismatch repair genes, hMLH1 and hMSH2, in sporadic endometrial carcinomas with microsatellite instability.

Microsatellite instability, monitored by replication error (RER), has been observed in both sporadic and hereditary types of endometrial carcinoma. In the hereditary tumors, this instability is considered to be caused by a germline defect in the DNA mismatch-repair system. We previously reported that nearly one-quarter of sporadic endometrial carcinomas examined revealed an RER-positive phenotype at multiple microsatellite loci. To investigate the role of genetic alterations of DNA mismatch-repair genes in sporadic endometrial carcinomas, we screened 18 RER(+) endometrial carcinomas for mutations of hMLH1 and hMSH2. Although we found no germline mutations, we detected two somatic mutations of hMLH1 in a single endometrial cancer; these two mutations had occurred on different alleles, suggesting that two separate mutational events had affected both copies of hMLH1 in this particular tumor. These data implied that mutations of hMLH1 or hMSH2 play limited roles in the development of sporadic endometrial carcinomas, and that the tumors with genetic instability might have alterations of other mismatch-repair genes, such as hPMS1 and hPMS2, or of unknown genes related to the mismatch-repair system.

[Treatment of advanced or recurrent cervical cancer by a new BOMP regimen consisting of bleomycin, vincristine, mitomycin-C, and low-dose consecutive cisplatin].

Twenty-five patients with cervical cancer (4 post-operative cases with FIGO stage Ib or IIb, 2 with stage IV, and 19 recurrence) were treated with a new BOMP consisting of bleomycin (5 mg/body, drip, i.v., days 1-7), vincristine (0.7 mg/m2, bolus, i.v., day 7), mitomycin-5 (7 mg/m2, bolus, i.v., day 7) and cisplatin (10 mg/m2, drip, i.v., days 1-7). The mean age of the patients was 54 years (range 30-77). Prior therapy included radiotherapy (13 cases), radical hysterectomy (11), and none (1). Fifteen (79%) of the 19 evaluable patients responded, including 6 with a complete response (CR) lasting over 15 months. Almost all the disease located in lung, liver, bone, and vulva showed a response. In particular, lesions confined to the lung had a 100% CR when the size of each tumor was under 2 cm in diameter even in the case of multiple metastasis. In contrast, 9 patients with pelvic disease had a 56% response with only 1 CR who had no previous radiotherapy. Such a poor response in the pelvic disease was considered to be due to vascularity reduced by prior radiotherapy. The important factors affecting the response to a new BOMP were found to be lesion size, prior radiotherapy, and the site of lesion. Patient age, performance status (PS), and the interval from a previous treatment to BOMP were not of significance with regard to response. The dose limiting factor was hematologic toxicities. Other toxicities including nausea, renal dysfunction, pulmonary fibrosis, and loss of hair were acceptable. Thus, the decrease in the PS of patients due to BOMP was minimal. It is suggested that this regimen will be useful as a neoadjuvant chemotherapy for advanced cervical cancer.

Hepatitis C virus infection is associated with the development of hepatocellular carcinoma.

A possible causative role for the recently discovered hepatitis C virus (HCV) in the development of hepatocellular carcinoma (HCC) was investigated by assay of sera from HCC patients in Japan for antibodies to a recombinant HCV antigen and to hepatitis B virus (HBV) antigens. Among the 253 HCC patients examined, 156 (61.7%) had no serum markers of either a previous or a current HBV infection (group I), 46 (18.2%) were negative for HBV surface antigen but positive for anti-HBV surface and/or anti-HBV core antibody, indicating the occurrence of a previous, transient HBV infection (group II), and 51 (20.2%) were chronically infected HBV carriers as evidenced by positivity for HBV surface antigen (group III). The prevalence of HCV antibody in group I (68.6%) and II (58.7%) patients was significantly higher than for group III (3.9%) or in 148 additional patients with other (non-HCC) cancers (10.1%) (P less than 0.01). Thus, there appears to be a strong association between HCV infection and the development of HCC, particularly in patients for which HBV infection cannot be implicated as a causative factor. The data also suggest an additional mode of transmission for HCV other than blood transfusion, since a history of blood transfusion was shown in only about 30% of the HCV antibody-positive HCC patients in groups I and II. A high prevalence of HCV antibody was also shown among patients with HCC whose disease was originally thought to be due to very high ethanol consumption.