Amplifications of proto-oncogenes in ovarian carcinoma

Thirty-two cases of ovarian carcinoma, two of normal ovaries, four of benign epithelial ovarian tumor, and three of borderline epithelial ovarian tumor were studied using Southern blot hybridization of DNA. In 15 of the 32 cases of ovarian carcinoma, peripheral lymphocytes were also studied. The amplification rate of C-myc, C-N-ras, C-Ki-ras and C-erbB-2 in ovarian carcinoma were 50%, 44%, 31% and 25% respectively. The amplification of C-Ki-ras and C-N-ras took place chiefly in cases of early stage and those of good differentiation. The amplification of C-N-ras was also found in cases of advanced stage. The amplifications of C-myc and C-erbB-2 were chiefly found in cases above stage III and those of poor differentiation. A total of 83% of the patients who died were found to have amplifications of more than 2 proto-oncogenes, with which the amplification of C-erbB-2 was involved.

Morphological classification of renal cancer

The current classification of renal-cell adenomas (RCAs) and carcinomas (RCCs) is based on eight basic cell and tumor types (entities) with characteristic morphologic features: (1) RCCs of clear-cell type, (2) RCAs/RCCs of chromophilic-cell type, (3) RCAs/RCCs of chromophobic-cell type, (4) RCCs of duct Bellini type, (5) RCCs of transitional-cell type, (6) RCCs of neuroendocrine type, (7) RCAs of oncocytic type, and (8) RCAs of metanephroid type. Tumors with a proposed histogenesis from the proximal tubule (clear-cell and chromophilic tumors) amount to 85% of renal cancers, whereas tumors with a proposed histogenesis from the connecting tubule/collecting duct (chromophobic-, oncocytic-, and duct Bellini-type tumors) amount to only 11%. The remaining tumor types represent rare entities (less than 1% each). Tumor cytogenetics data confirm the proposed eight morphologic subtypes and give further indications for type-specific tumor development and progression.

[Appearance in 2 brothers of double primary neoplasms: right renal carcinoma and gastric adenocarcinoma]

We report a clinical case of a double primitive tumour (right kidney clear cell carcinoma and gastric carcinoma) in two brothers. There is no history of cancer in the parents. Both patients were previously affected by gastric ulcer. No report of association between the two neoplasms was found in literature. The age of the patients (61 and 70 years) and the singleness of the kidney tumour seem to exclude the case of a familial kidney cancer. The neoplastic transformation of the gastric ulcer is instead a quite frequent report with an incidence of about 1%. Alterations of oncogenes or tumour suppressor genes shared from both neoplasm are at present still unknown. Nevertheless molecular analysis of patients' neoplastic genome could point out typical chromosome translocations/deletions or gene mutations.

Alteration of the p53 tumor suppressor gene occurs independently of K-ras activation and more frequently in serous adenocarcinomas than in other common epithelial tumors of the human ovary

To clarify the role of the p53 tumor suppressor gene in the development of human ovarian epithelial tumors and to study the association of p53 alterations with K-ras activation, a series of 70 common epithelial ovarian tumors from Japanese patients was studied. These included 31 serous adenocarcinomas, 12 mucinous adenocarcinomas, 5 mucinous tumors of borderline malignancy, 13 endometrioid adenocarcinomas, and 9 clear cell carcinomas. Allelic loss, recognized at the polymorphic site in codon 72 of the p53 gene, was detected in 14 of 36 (39%) informative cases by restriction fragment length polymorphism analysis and by single-strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR)-amplified DNA fragments. Mutations in the highly conserved regions of the p53 gene were detected by SSCP analysis of PCR-amplified fragments. Mutations were found in 22 of 70 (31%) ovarian tumors, including 1 of 5 mucinous tumors of borderline malignancy. Mutations were subsequently characterized by direct sequencing. Single missense base substitutions were detected in 13 ovarian carcinomas and in one case of mucinous tumor of borderline malignancy. Short (1-8 bp) deletions and insertions were found in 8 cases. Mutations in the p53 gene occurred more frequently in serous adenocarcinomas (14/31, 45%) than in all nonserous types of malignant epithelial tumors combined (7/34, 21%; P = 0.032). Point mutations in K-ras were identified by dot blot hybridization analysis of PCR-amplified fragments with mutation-specific oligonucleotides and by direct sequencing. The overall frequency of K-ras mutations was 19/70 (27%). K-ras mutations were found in 12 of 17 (71%) mucinous tumors (8/12 mucinous carcinomas [67%] and 4/5 mucinous tumors of borderline malignancy [80%]), and occurred more frequently than in serous carcinomas (4/31, 13%; P = 0.00009) or in all nonmucinous types of ovarian epithelial tumors combined (7/53, 13%; P = 0.00002). These data suggest that different combinations of oncogenes and/or tumor suppressor genes may be involved in the genesis and development of histologically distinct categories of common epithelial tumors of the human ovary.

Alteration of p53 gene in ovarian carcinoma: clinicopathological correlation and prognostic significance

Inactivation of the tumour-suppressor gene p53 has been demonstrated in a variety of human tumours. We extracted DNA from paraffin-embedded tissues of 67 ovarian carcinoma samples (54 primary tumours, seven metastases and six tumours obtained after chemotherapy), and analysed allelic losses and mutations of the p53 gene using single-strand conformation polymorphism (SSCP) analysis of DNA fragments amplified by a polymerase chain reaction (PCR). Allelic loss was observed in 24 of 32 informative cases. The mutation was detected in 14 of 54 primary ovarian carcinomas: eight serous cystadenocarcinomas (SCA), 42%), five endometrioid adenocarcinomas (EA, 42%) and one mucinous cystadenocarcinoma (14%). The incidence of the alteration was higher in SCA and EA than in other histological types, but the difference was not statistically significant. The incidence of p53 gene abnormalities in ovarian carcinomas tended to be increased in patients with disease advanced (over FIGO stage II). Mutations were found in exons 5 and 7 only and consisted mainly of single nucleotide substitutions [9 or 14 (64%) in exon 7; 4 of 14 (29%) in exon 5]. In 13 of 14 cases, p53 gene mutations occurred concomitantly with losses of the normal allele. The status of the p53 gene in metastases and the tumours obtained after chemotherapy was identical to that in the primary tumours. The presence of p53 gene mutation did not correlate with histological grade, response to primary therapy and survival. These findings suggest that mutational alterations of the p53 gene are involved in the development of a significant proportion of some ovarian carcinomas (SCAs or EAs), especially in advanced stages. However, they may not be a marker predicting the biological behaviour or the outcome of the disease.

Somatic mutations of the von Hippel-Lindau disease tumour suppressor gene in non-familial clear cell renal carcinoma

Loss of heterozygosity (LOH) studies have suggested that somatic mutations of a tumour suppressor gene or genes on chromosome 3p are a critical event in the pathogenesis of non-familial renal cell carcinoma (RCC). Germline mutations of the von Hippel-Lindau (VHL) disease gene predispose to early onset and multifocal clear cell renal cell carcinoma, and the mechanism of tumorigenesis in VHL disease is consistent with a one-hit mutation model. To investigate the role of somatic VHL gene mutations in non-familial RCC, we analysed 99 primary RCC for VHL gene mutations by SSCP and heteroduplex analysis. Somatic VHL gene mutations were identified in 30 of 65 (46%) sporadic RCC with chromosome 3p allele loss and one of 34 (3%) tumours with no LOH for chromosome 3p. The VHL gene mutations were heterogeneous (17 frameshift deletions, eight missense mutations, four frameshift insertions, one nonsense and one splice site mutation), but no mutations were detected in the first 120 codons of cloned coding sequence. Most RCCs with somatic VHL mutations (23 of 27 (85%) informative cases) had chromosome 3p25 allele loss in the region of the VHL gene so that both alleles of the VHL gene had been inactivated as expected from a two-hit model of tumorigenesis. Detailed histopathology was available for 59 of the tumours investigated: 18 of 43 (42%) RCC with a clear cell appearance had a somatic VHL gene mutation but none of 16 non-clear cell RCC (eight chromophilic, three chromophobe and five oncocytoma) (chi2 = 7.77, P < 0.025).(ABSTRACT TRUNCATED AT 250 WORDS)

Clear cell adenocarcinoma of the vagina in a young female, treated by combination chemotherapy (local and systemic chemotherapy), complicated with chromosomal abnormality

Although cancer of the vagina, a rare form of genital cancer, is usually squamous cell carcinoma in women over the age of 50 years, vaginal clear cell adenocarcinomas (CCA) are exceedingly rare. The pathogenesis of clear cell adenocarcinoma is uncertain, but as a clinical entity, it is most commonly associated with diethylstilbestrol exposure in utero. We report a rare case of primary vaginal CCA in a 17-year-old female who was not exposed to diethylstilbesterol in utero. The case, which was complicated with chromosomal abnormality, was treated with combination chemotherapy. To our knowledge, this is the first reported case of vaginal CCA in a woman with chromosomal abnormality and bicornate uterus.

Silencing of the VHL tumor-suppressor gene by DNA methylation in renal carcinoma

Mutational inactivation and allelic loss of the von Hippel-Lindau (VHL) gene appear to be causal events for the majority of spontaneous clear-cell renal carcinomas. We now show that hypermethylation of a normally unmethylated CpG island in the 5' region provides another potentially important mechanism for inactivation of the VHL gene in a significant portion of these cancers. This hypermethylation was found in 5 of 26 (19%) tumors examined. Four of these had lost one copy of VHL while one retained two heavily methylated alleles. Four of the tumors with VHL hypermethylation had no detectable mutations, whereas one had a missense mutation in addition to hypermethylation of the single retained allele. As would be predicted for the consequence of methylation in this 5' CpG island, none of the 5 tumors expressed the VHL gene. In contrast, normal kidney and all tumors examined with inactivating VHL gene mutations but no CpG island methylation had expression. In a renal cell culture line, treatment with 5-aza-2'-deoxycytidine resulted in reexpression of the VHL gene. These findings suggest that aberrant methylation of CpG islands may participate in the tumor-suppressor gene inactivations which initiate or cause progression of common human cancers.

Human papillomavirus detection and p53 expression in clear-cell adenocarcinoma of the vagina and cervix

OBJECTIVE

To determine whether infection with oncogenic human papillomavirus (HPV) and/or altered expression of the tumor suppressor protein p53 is associated with clear-cell adenocarcinoma of the vagina or cervix.

METHODS

Paraffin-embedded tissue specimens were studied from 14 women with clear-cell adenocarcinoma of the vagina or cervix. Nine women had a history of intrauterine diethylstilbestrol exposure. Human papillomavirus DNA was amplified via the polymerase chain reaction using consensus L1 primers and was detected by dot blot hybridization with a generic HPV probe and type-specific oligonucleotide probes. P53 protein was detected by immunohistochemical analysis with a mouse monoclonal antibody, DO-7.

RESULTS

Three tumors contained HPV 31 DNA sequences. Eight tumors were HPV DNA-negative and three were indeterminate for HPV. P53 was detected in ten tumors; it was undetectable in the three tumors containing HPV 31 and in one tumor indeterminate for HPV. Three patients presented with or later developed metastatic disease. In each case, the tumor, including sites of metastasis, was HPV-negative and p53-positive.

CONCLUSIONS

These findings suggest that infections with oncogenic HPVs may be a cofactor in the development of clear-cell adenocarcinoma of the vagina or cervix, though this association is less than that reported for squamous or non-clear-cell adenocarcinomas. Prior studies have shown that detection of the p53 protein by immunohistochemistry correlates with mutations in the p53 tumor suppressor gene. The detection of p53 in HPV-negative clear-cell adenocarcinoma suggests a second mechanism in the etiology of these rare tumors.

Type-IV collagenase and tissue inhibitor of metalloproteinase in ovarian cancer tissues

OBJECTIVE

We examined the specific expression of gelatinase/type-IV collagenase and tissue inhibitor of metalloproteinase (TIMP) in clinical ovarian cancer tissue.

METHODS

Molecular weight-specific gelatinase/type-IV collagenase activity was examined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis in which substrate was included (zymography). The expression of TIMP mRNA was examined by Northern blot analysis.

RESULTS

Zymography revealed that in ovarian cancer the activity of a 92-kDa gelatinase/type-IV collagenase was always greater than that of a 64-kDa gelatinase/type-IV collagenase in contrast to the situation in the normal ovary. Northern blot analysis revealed no remarkable difference of TIMP mRNA expression between cancer and normal ovarian tissues.

CONCLUSIONS

These results indicate that the higher activity of the 92-kDa gelatinase/type-IV collagenase enzyme, relative to that of the 64-kDa enzyme, is involved in the malignant phenotype of ovarian cancer, while the inhibitor of these enzymes, TIMP, is distributed in a widespread fashion in the tissue, and its levels are not correlated with the malignancy.

Amplification of the C-erbB-2(HER-2/neu) proto-oncogene in ovarian carcinomas

C-erbB-2(HER-2/neu) proto-oncogene is mainly expressed in epithelial tissue and activated due to its amplification. Amplification of the C-erbB-2 proto-oncogene has been associated with poor prognosis in human ovarian cancer. Our study was to examine whether amplification is more frequently observed in ovarian cancer, or it is associated with poor prognosis of human ovarian cancer in China. The DNA of ovarian cancers was extracted and consequently digested with restriction endonuclease EcoRI, electrophoresed in 0.8% agarose gels and blotted onto nitrocellulose filter with Southern transferring method. It was then hybridized with a 32P-labelled C-erbB-2 probe and subsequently underwent autoradiography. The result has shown that the C-erbB-2(HER-2/neu) gene was amplified in 8 of 26 human ovarian cancers (30.8%). The clinical data showed that all of the 8 cases with the amplified C-erbB-2 were in their advanced stage (III-IV). Five of the patients died from 2 to 4 months after operation. These data suggest that amplification of the C-erbB-2 gene may play a role in the pathogenesis of ovarian carcinoma; it is frequently observed in advanced ovarian cancer and is associated with poor prognosis for these patients.

The use of DNA typing to clarify the origin of metastatic carcinoma after renal transplantation. A clinical and medico-legal problem

We present an unusual diagnostic problem in a transplant patient whose failed renal transplant was found to contain undifferentiated carcinoma. When the patient later developed metastatic renal carcinoma, he began legal proceedings against the hospital for the transmission of a tumour with his renal transplant. He subsequently died of carcinomatosis. Post-mortem examination revealed acquired renal cystic disease in his native kidneys with a 1-cm adenocarcinoma arising from the wall of one of the cysts. We used DNA typing to determine the origin of the metastatic tumour and resolve the medico-legal problem.

Common regions of deletion in chromosome regions 3p12 and 3p14.2 in primary clear cell renal carcinomas

Nearly all clear cell renal cell carcinomas (RCCs) exhibit loss of alleles on the short arm of chromosome 3. Loss and mutation at the von Hippel-Lindau (VHL) gene at 3p25 probably occurs in most RCCs and, since the VHL gene was recently cloned, data on VHL involvement in RCCs is accumulating. However, the region 3p14-p12, a region that contains the familial RCC-associated t(3;8)(p14.2;q24) chromosome translocation and the small cell lung carcinoma-associated homozygous deletion at 3p13-12, has also been reported to exhibit allele loss in a large fraction of RCCs. In order to focus future studies on potential suppressor genes in the 3p14-p12 region, we have studied allele loss in 30 RCCs with 9 polymorphic simple sequence repeat markers spanning 3p21.1-p12. Partial losses in the 3p21-p12 region were observed, allowing determination of common regions of loss of heterozygosity overlap in 15 RCCs. Results suggested that most RCCs exhibit loss in a region which brackets the t(3;8) familial chromosome translocation at 3p14.2, and some show additional deletions within the U2020 small cell lung carcinoma deletion at 3p12.

Homozygous deletions on the short arm of chromosome 9 in ovarian adenocarcinoma cell lines and loss of heterozygosity in sporadic tumors

Rat ovarian surface epithelial cells transformed spontaneously in vitro have been found to have homozygous deletions of the interferon alpha (IFNA) gene. This suggests that inactivation of a tumor-suppressor gene in this region may be crucial for the development of ovarian cancer. We therefore used microsatellite markers and Southern analysis to examine the homologous region in humans--the short arm of chromosome 9--for deletions in sporadic ovarian adenocarcinomas and ovarian tumor cell lines. Loss of heterozygosity occurred in 34 (37%) of 91 informative sporadic tumors, including some benign, low-malignant-potential and early-stage tumors, suggesting that it is an early event in the development of ovarian adenocarcinoma. Furthermore, homozygous deletions on 9p were found in 2 of 10 independent cell lines. Deletion mapping of the tumors and lines indicates that the candidate suppressor gene inactivated as a consequence lies between D9S171 and the IFNA locus, a region that is also deleted in several other tumors and that contains the melanoma predisposition gene, MLM.

Mutations of the VHL tumour suppressor gene in renal carcinoma

Multiple, bilateral renal carcinomas are a frequent occurrence in von Hippel-Lindau (VHL) disease. To elucidate the aetiological role of the VHL gene in human kidney tumorigenesis, localized and advanced tumours from 110 patients with sporadic renal carcinoma were analysed for VHL mutations and loss of heterozygosity (LOH). VHL mutations were identified in 57% of clear cell renal carcinomas analysed and LOH was observed in 98% of those samples. Moreover, VHL was mutated and lost in a renal tumour from a patient with familial renal carcinoma carrying the constitutional translocation, t(3;8)(p14;q24). The identification of VHL mutations in a majority of localized and advanced sporadic renal carcinomas and in a second form of hereditary renal carcinoma indicates that the VHL gene plays a critical part in the origin of this malignancy.

Cytomorphological, cytogenetic, and molecular biological characterization of four new human renal carcinoma cell lines of the clear cell type

Four new permanent cell lines (RCC-A, -B, -C, and -D) derived from different human renal cell carcinomas of the clear cell type were established in tissue culture. The cell lines displayed characteristic differences in cell size and shape, which allowed individual identification by phase contrast microscopy. Ultrastructurally, the cell lines exhibited varying amounts of cytoplasmatic glycogen and lipid. Immunohistochemistry revealed co-expression of vimentin and cytokeratin in all cell lines. The mean population doubling time ranged from 27 h (RCC-A) to 104 h (RCC-D). RCC-B and -C cells produced slowly growing tumours after heterotransplantation into nude mice, whereas RCC-A and RCC-D cells were non-tumorigenic. The modal chromosome number was either near-diploid (RCC-A, -B, and -C) or near triploid (RCC-D). Clonal abnormalities affecting the short arm of chromosome 3 were seen in all cell lines. Northern blot analysis revealed no expression of the proto-oncogenes c-fos, c-ros, and c-mos, whereas c-Ki-ras expression was observed in all cell lines. Expression of c-myc was observed in RCC-A, RCC-B, and RCC-D cells, whereas c-raf expression could be detected in RCC-B and RCC-D. Tumour suppressor gene p53 mRNA was observed in the cell line RCC-D.

Interphase cytogenetics in paraffin-embedded sections from renal cortical neoplasms. Correlation with cytogenetic and flow cytometric DNA ploidy analyses

Nonisotopic in situ hybridization (ISH) was performed on archival tissue sections from six renal cortical neoplasms and corresponding normal kidney tissue using pericentrometric (alpha-satellite) probes to chromosomes 1, 3, 7, 8, 10, 11, 12, 16, and 17. The results were correlated with classic cytogenetic analyses and flow cytometric DNA ploidy findings of these neoplasms. Our study shows that intratissue and intertissue ISH spot counts were generally homogeneous in normal kidney tissue and markedly heterogenous in tumor specimens. In all cases the correlation between the DNA Index and the ISH spot numbers was statistically significant. A correlation between modal and numerical chromosomal findings by cytogenetic analysis and ISH spot counts was found in three cases and was discordant in three cases. Our results also show that chromosomes 1, 3, 7, and 17 appear to manifest more propensity for aneuploidy than chromosomes 8, 10, 11, 12, and 16. We conclude that 1) numerical chromosomal aberrations by interphase in-situ hybridization correlate with DNA ploidy analysis in these tumors; 2) certain chromosomes may be more prone to aneuploidy than others; 3) determination of monosomy by ISH is less reliable on paraffin-embedded sections; and 4) the ISH technique complements conventional cytogenetic analysis in providing more information for the determination of cytogenetic aberrations and clonal heterogeneity in solid neoplasms.

Activation of c-erbB-2 and prognosis in ovarian carcinoma. Comparison with histologic type, grade, and stage

BACKGROUND

Prior reports suggested that measuring c-erbB-2 activation in ovarian carcinomas might be valuable in predicting prognosis. The authors attempted to confirm these studies while specifically excluding tumors of low malignant potential.

METHODS

The clinical and pathologic significance of c-erbB-2 oncogene activation was assessed in 56 ovarian carcinomas, none of which met histologic criteria for tumor of low malignant potential.

RESULTS

By using an immunohistochemical technique previously validated in molecular studies, c-erbB-2 oncogene overexpression was identified in 10 of the 56 carcinomas but did not correlate with histologic type, histologic grade, International Federation of Gynecology and Obstetrics (FIGO) stage, or prognosis. Adverse prognostic factors included histologic type (serous carcinoma), high grade, and high stage (FIGO Stages III and IV). Grade and stage were highly correlated with each other and were more important prognostic indicators than histologic type.

CONCLUSION

Measuring c-erbB-2 activation in ovarian carcinomas may not be of practical value in predicting prognosis when tumors of low malignant potential are excluded.

[Establishment and characterization of a CA125-producing human ovarian clear cell carcinoma cell line]

A human ovarian cancer cell line designated "KK" was established from ascites of a patient with ovarian clear cell carcinoma. This cell line was grown for more than 2 years and over 140 passages in medium RPMI1640 containing 10% FCS. Doubling time of this cell line at passage 70 was approximately 4 days and saturation density was 1.1 x 10(5)/cm2. Plating efficiency was approximately 23%. Chromosome analysis revealed aneuploidy with a model number of 67. PAS-positive substances were present in the cytoplasm. CA125 and SLX were detected in both the original tumor and the cultured cells. This cell line is less sensitive to cisplatin than KF cells and IC50 was 0.95 microM.

Hypercalcaemia due to parathyroid hormone-related protein: long-term circulating levels may not reflect tumour activity

Parathyroid hormone-related protein is responsible for the hypercalcaemia caused by many tumours. Measurement of parathyroid hormone-related protein is becoming more accessible with the introduction of commercial assays. We report a case of hypercalcaemia of malignancy secondary to parathyroid hormone-related protein in a woman with renal carcinoma. The parathyroid hormone-related protein was assayed using a new immunoradiometric assay. We demonstrated an initial fall in parathyroid hormone-related protein and calcium levels after surgery and a rise in both before clinical relapse. However, the clinical relapse was itself associated with a fall in serum parathyroid hormone-related protein, nephrogenous cAMP and calcium, suggesting that the tumour had stopped producing parathyroid hormone-related protein or perhaps that post-translational processing had occurred as the tumour advanced. The tumour was investigated for parathyroid hormone-related protein mRNA content using reverse transcriptase polymerase chain reaction, both at diagnosis in surgically removed material, and using post-mortem specimens. The level of parathyroid hormone-related protein mRNA, while present, was much reduced in the recurrent tumour suggesting that active parathyroid hormone-related protein production fell substantially as the tumour advanced. This case suggests that, although demonstration of parathyroid hormone-related protein in hypercalcaemia is useful for diagnosis, tumoral secretion of this product may alter.

Cytogenetic studies of epithelial ovarian carcinoma

We performed cytogenetic studies of 36 human epithelial ovarian carcinomas using in situ culture and robotic harvest. We obtained analyzable metaphases of all 36 tumors (100%). One or more chromosomally abnormal clones were observed in 80% of tumors. Common clonal chromosome gains (each occurring in six or more cases) included +1, +2, +3, +6, +7, +9, and +12. Common clonal chromosome losses (occurring in 12 or more cases) included -X, -4, -8, -11, -13, -15, -17, and -22. Common clonal structural abnormalities (occurring in four or more cases) involved regions 1p36, 1q32, 1q42, 3p13-->p26, 3q26-->q29, 7p22, 9q34, 11p13-p15, 17q21-->q23, 19p13.3, and 19q13.3. Trisomy 12 was noted as the sole anomaly in three of five borderline and grade 1 tumors. Two grade 2 tumors contained i(1q), -14, -15 and -22. The results suggest that the pathogenesis of borderline and low-grade tumors may differ from that of higher grade tumors. Two high-grade tumors had an apparent translocation between 17q21 and 19p13.3, two chromosome regions believed to be critical to ovarian carcinogenesis.