CAR is a cell-cell adhesion protein in human cancer cells and is expressionally modulated by dexamethasone, TNFalpha, and TGFbeta

The coxsackie adenovirus receptor (CAR) has become of interest for gene therapy due to its crucial function in adenoviral cell entry. In clinical trials with adenoviral vectors, dexamethasone is applied to reduce side effects such as inflammatory reactions or emesis. By using a beta-galactosidase-expressing adenovirus (AdGal), we observed that dexamethasone treatment resulted in decreased adenoviral gene transfer into human cancer cells. Expression of CAR and integrin alpha5beta1 was transcriptionally downregulated by dexamethasone as shown for HeLa cervical cancer cells and U87MG glioblastoma cells. TNFalpha increased CAR expression in HeLa and ovarian cancer cells but decreased CAR expression in U87MG cells. In all tested cancer cell lines, TNFalpha induced a significant increase in the expression of adenovirus-binding integrins alpha5beta1, alphavbeta3 and alphavbeta5. Pretreatment with TNFalpha increased AdGal gene transfer into cancer cells and enhanced the cytotoxic effect of a p53-expressing adenovirus. In contrast, TGFbeta reduced CAR expression level and adenoviral gene transfer into OV-UL-2 ovarian cancer cells. Confocal immunofluorescence analysis revealed localization of CAR at cell-cell adhesions in several human cancer cell lines and disruption of cell-cell contacts increased adenoviral gene transfer into human cancer cells. In clinical cancer gene therapy, efficiency of adenoviral gene delivery could be altered by cell adhesion, TNFalpha, TGFbeta, and dexamethasone.

Modulation of soluble CD44 concentrations by hormone and anti-hormone treatment in gynecological tumor cell lines

Serum levels of CD44 (sCD44) are increased in a variety of human diseases including gynecological malignancies showing hormone-dependent growth and proliferation. Very little is known about the mechanisms underlying the processing of soluble CD44 and influencing its release. Due to their major impact on gene transcription and cell proliferation steroid hormones or their antagonists might influence sCD44 processing. We investigated the effects of different hormonal conditions on overall soluble CD44 (sCD44std) concentrations in a subset of gynecological tumor cell lines. Established human breast and endometrium cancer cell lines were characterized for their membrane-bound CD44 protein, CD44 mRNA expression and steroid receptor status prior and after incubation with 17beta estradiol (E2), medroxyprogesterone acetate (MPA), 4-hydroxy-tamoxifen (4-OH-Tam) and the gonadotropin releasing hormone (GnRH) agonist busereline. An enzyme linked immuno-sorbent assay (ELISA) using a monoclonal antibody directed against an epitope common to all CD44 isoforms was used to determine sCD44 levels in the supernatants of the tested cell lines. Interestingly, a strong correlation between sCD44 levels and the receptor status of the cells was seen. However, membrane-bound CD44 expression was not influenced by the hormonal environment. Our results indicate that distinct steroid hormones can specifically influence concentrations of soluble CD44. How this effect is involved in the tumorigenesis of gynecological malignancies and whether it might contribute to the biological behavior of special tumors should be investigated in further studies.

Progesterone receptor variant increases ovarian cancer risk in BRCA1 and BRCA2 mutation carriers who were never exposed to oral contraceptives

Oral contraceptives have been shown to be protective against hereditary ovarian cancer. The variant progesterone receptor allele named PROGINS is characterized by an Alu insertion into intron G and two additional mutations in exons 4 and 5. The PROGINS allele codes for a progesterone receptor with increased stability and increased hormone-induced transcriptional activity. We studied the role of the PROGINS allele as a modifying gene in hereditary breast and ovarian cancer. The study included 195 BRCA1 and BRCA2 carriers with a prior diagnosis of ovarian cancer, 392 carriers with a diagnosis of breast cancer and 249 carriers with neither cancer. Fifty-eight women had both forms of cancer. Five hundred and ninety-five women had a BRCA1 mutation and 183 women had a BRCA2 mutation. Overall, there was no association between disease status and the presence of the PROGINS allele. Information on oral contraception use was available for 663 of the 778 carriers of BRCA1 or BRCA2 mutations. Among the 449 subjects with a history of oral contraceptive use (74 cases and 365 controls), no modifying effect of PROGINS was observed [odds ratio (OR) 0.8; 95% confidence interval (CI) 0.5-1.3]. Among the 214 carriers with no past exposure to oral contraceptives, the presence of one or more PROGINS alleles was associated with an OR of 2.4 for ovarian cancer, compared to women without ovarian cancer and with no PROGINS allele (P = 0.004; 95% CI 1.4-4.3). The association was present after adjustment for ethnic group and for year of birth.

Ribozyme-mediated telomerase inhibition induces immediate cell loss but not telomere shortening in ovarian cancer cells

Telomerase is a promising target for human cancer gene therapy. Its inhibition allows telomere shortening to occur in cancer cells, which in turn is thought to trigger delayed senescence and/or apoptosis. We tested whether telomerase inhibition might have additional, immediate effects on tumor cell growth. Ovarian cancer cell lines with widely differing telomere lengths were efficiently transduced with an adenovirus expressing a ribozyme directed against the T motif of the catalytic subunit of human telomerase, hTERT. Three days after transduction, telomerase activity was significantly reduced and massive cell loss was induced in mass cultures from all four ovarian cancer cell lines tested, whereas transduction of telomerase-negative human fibroblasts did not attenuate their growth. The kinetics of induction of cell death in cancer cells was not significantly dependent on telomere length, and telomeres did not shorten measurably before the onset of apoptosis. The data suggest the existence of a "fast-track" mechanism by which diminution of telomerase can interfere with cancer cell growth and induce cell death, presumably by apoptosis. This phenomenon might be a consequence of the telomere capping function provided by telomerase in tumor cells. Uncapping of telomeres by ribozyme-mediated inhibition of telomerase bears therapeutic potential for ovarian cancer.

Correlation of p53 mutations with resistance to platinum-based chemotherapy and shortened survival in ovarian cancer

PURPOSE

The p53 tumor suppressor gene plays a central role in cell cycle regulation and induction of apoptosis. We analyzed p53 alterations and their impact on response to chemotherapy and clinical outcome in ovarian cancer patients.

EXPERIMENTAL DESIGN

One hundred seventy-eight ovarian carcinomas, snap frozen and stored at -80 degrees C, were analyzed for mutations of the p53 gene (exons 2-11) by single-strand conformation polymorphism and DNA sequencing and for p53 overexpression by immunohistochemistry (monoclonal antibody DO7).

RESULTS

p53 mutations were found in 56% (99 of 178) of the tumors, and 62% of these were located in evolutionary highly conserved domains of the gene. Time to progression and overall survival were significantly shortened in patients with p53 mutations compared with wild-type p53 (P = 0.029 and P = 0.014) and patients with mutations in highly conserved domains as opposed to nonconserved domains or wild-type p53 (P = 0.010 and P = 0.007). p53 protein overexpression (>10% positively stained nuclei) was found in 62% (110 of 178). Time to progression and overall survival were shorter in cases with p53 overexpression (cutpoint, 10%: P = 0.071 and P = 0.056) but only marginally significant. Resistance to adjuvant cisplatin or carboplatin chemotherapy was significantly more frequent in patients with p53 overexpression (P = 0.001) or p53 missense mutations (P = 0.008) than patients with normal p53.

CONCLUSIONS

p53 alterations correlate significantly with resistance to platinum-based chemotherapy, early relapse, and shortened overall survival in ovarian cancer patients in univariate analysis. In multivariable analysis though, p53 was not an independent prognostic factor.

Adenoviral transduction efficiency of ovarian cancer cells can be limited by loss of integrin beta3 subunit expression and increased by reconstitution of integrin alphavbeta3

Recombinant adenoviruses expressing a therapeutic gene are currently used in clinical studies for treatment of advanced ovarian cancer. We therefore tested whether the expression level of primary (CAR) and secondary adenovirus receptors (integrins) was predictive of the efficacy of adenoviral gene transfer in ovarian cancer cells. Adenoviral transduction efficiency (ATE) was determined with an E1-deleted adenovirus type 5 expressing beta-galactosidase under a CMV promoter (AdGal). ATE was studied in relationship to the expression level of both CAR (coxsackie and adenovirus receptor) and integrins. A representative sample of 25 permanent human cell lines established from advanced ovarian cancer in our laboratory and the OV-2774 cell line were tested. Overall, ATE increased with increasing titers of AdGal. At a given titer of 50 infectious units per cell, transduction efficiency varied from 6 to 94% among the individual cell lines. All cell lines expressed CAR and integrin alpha(v)beta(5), but no relation between ATE and expression level of CAR or alpha(v)beta(5) integrin was observed. In contrast, cell lines with poor ATE, despite expressing high levels of CAR, lacked expression of integrins alpha(v)beta(3) and alpha(5)beta(1). Reconstitution of alpha(v)beta(3) integrin by reexpressing the beta(3) subunit significantly enhanced ATE of ovarian cancer cells. In ovarian cancer, neither integrins nor CAR alone appear to be potentially useful predictive markers for ATE by serotype 5 adenovirus in clinical gene therapy. A minimum level of CAR necessary for binding of adenoviruses was observed in all tested ovarian cancer cell lines. Loss of alpha(v)beta(3) integrin is frequently associated with advanced stages of ovarian cancer and can significantly reduce ATE.

Epidemiological and molecular aspects of ovarian cancer risk

In Western and Northern Europe, as well as in the United States, ovarian cancer represents the third most frequent cancer of the female genital tract with an estimated 191,000 newly diagnosed cases per year worldwide. Due to its insidious onset, the disease is diagnosed in 70% of cases in an advanced stage. Consequently, ovarian cancer is the fifth leading cause of cancer-related deaths in women. Epidemiological and molecular studies reviewed here have identified demographic, geographic, molecular, genetic, endocrine, dietary, and environmental factors, which affect the risk of developing ovarian cancer: ethnic background, tumor suppressor gene mutations in the germline, positive family history, number of full-term pregnancies [odds ratio (OR): 0.17; 95% confidence interval (CI): 0.05-0.54], time spent breast feeding, oral contraceptive use [OR: 0.23; 95% CI: 0.1-0.50], unexplained infertility (OR: 2.64; 95% CI: 1.10-6.35), tubal ligation and prior hysterectomy (OR: 0.5; 95% CI: 0.2-0.9), dietary factors and obesity (OR: 1.7; 95% CI: 1.1-2.8). This knowledge provides the objective basis for an individual risk assessment for women, which should lead to sophisticated counseling and prevention. It should also help to individualize the therapeutic approach in the event that disease is diagnosed.

Autoimmunity against p53 predicts invasive cancer with poor survival in patients with an ovarian mass

Serum autoantibodies against the p53 protein (p53 AAb) were analysed with a newly developed enzyme-linked immunosorbent assay (ELISA) based on highly purified and renatured p53. In a hospital-based cohort study, preoperative sera from 113 patients with ovarian cancer, 15 patients with borderline tumours and 117 patients with benign tumours of the ovaries were studied. The prevalence of p53 AAb in patients with invasive cancer was 19% (21/113). No p53 AAb were found in patients with borderline lesions or benign tumours. The ELISA had a specificity for malignancy of 99% (1 of 117; false-positive from a patient with severe diabetes mellitus) and a likelihood ratio (LR+) for a positive test result of 21.7 (elevated CA125 and malignancy: LR+ 3.7). p53 AAb were only detectable in patients with immunohistochemical staining of nuclear p53 in the tumour (P = 0.006). Presence of p53 AAb positively correlated with tumour stage (P = 0.034) and grade (P = 0.009). Kaplan-Meier analysis showed both a shortened overall survival (P = 0.0016, log-rank) and relapse-free survival (P = 0.055) for p53 AAb-positive patients (median follow-up 22 months). High titres related to even worse prognosis. p53 AAb independently related to poor survival adjusting for stage (P = 0.026), grade (P = 0.029) and residual disease after surgery (P = 0.005). Preoperative findings of adnexal mass with serum p53 AAb are strongly suggestive of an aggressive invasive ovarian cancer.

Soluble CD44 splice variants and pelvic lymph node metastasis in ovarian cancer patients

Alternative splicing of CD44 and aberrant levels of soluble CD44 protein in the serum of cancer patients has been correlated to tumor progression and metastasis. To examine the clinical value of CD44 serum levels (sCD44) in ovarian cancer we determined concentrations of the soluble, variable isoforms sCD44std, sCD44v5 and sCD44v6 with a sensitive ELISA. Pre-operative serum samples from 66 patients with histologically diagnosed invasive disease as well as sera taken from 40 healthy blood donors were analyzed. In sera of ovarian cancer patients we detected elevated concentrations of overall CD44 serum levels represented by sCD44std (p=0.001), but decreased levels of the specific isoforms CD44v5 (p=0.0002) and v6 (p=0.0001). This is the first report demonstrating that ovarian cancer patients with pelvic lymph node metastasis at the time of diagnosis showed specifically elevated sCD44v6 (p=0.073) serum concentrations in comparison to patients without lymph node involvement, whereas overall sCD44 serum levels did not differ. Decreased serum levels of sCD44v5 were found in progesterone receptor-positive tumors (p=0. 059) and postmenopausal patients (p=0.032). Increased concentrations of sCD44v6 were detectable in estrogen receptor-positive tumors but not significantly (p=0.138). Serum CD44v5 levels were associated with shortened relapse-free survival time. No association was found between serum CD44 isoforms and the classical clinicopathological parameters stage and grading or overall survival. CD44 splice variants are possibly involved in a complex interaction with the hormonal environment during tumorigenesis and metastasis of ovarian cancer.

Progesterone receptor gene polymorphism is associated with decreased risk for breast cancer by age 50

In a population-based case-control study for breast cancer before the age of 51 years, 554 cases and 559 age-matched controls were genotyped for the polymorphic progesterone receptor allele PROGINS. Breast cancer risk was decreased in women carrying the PROGINS allele. The odds ratio adjusted for age and study region was 0.76 [95% confidence interval (CI), 0.58-1.00]. Compared with wild-type A1/A1 homozygotes, the odds ratio for A1/A2 heterozygotes and A2/A2 homozygotes was 0.82 (95% CI, 0.62-1.08) and 0.27 (95% CI, 0.10-0.74), respectively, suggesting a gene dosage effect of the A2 allele. There was suggestive evidence for a differential effect by menopausal status (P = 0.07) and by family history of breast cancer (P = 0.15).

Growth suppression of human ovarian carcinoma OV-MZ-2a and OV-MZ-32 cells mediated by gene transfer of wild-type p53 enhanced by chemotherapy in vitro

PURPOSE

The aim of this work was to observe the growth and chemosensitivity of human ovarian cancer OV-MZ-2a and OV-MZ-32 cells following adenovirus-based wild-type p53 (Ad-p53) gene transfer alone or combined with chemotherapeutic agents.

METHODS

Transduction efficiency was determined with a reporter construct of adenovirus galactosidase by staining with 5-bromo-4-chloro-3-indolyl beta-D-galactoside. For growth inhibition, OV-MZ-2a or OV-MZ-32 cells were infected with Ad-p53 particles at a multiplicity of infection (m.o.i.) of 0.2-20, alone or combined with the chemotherapeutic agents taxol, cisplatin, doxorubicin or mitomycin C. Growth inhibition (assayed by trypan blue exclusion), target gene expression (by Western blotting) and clonogenicity (by soft-agar assay) were determined following Ad-p53 transfer.

RESULTS

High transduction efficiency was observed following adenovirus galactosidase gene transfer; 94% of OV-MZ-2a cells and 69% of OV-MZ-32 cells expressed the transgene. Following transfer of Ad-p53 into the two cell lines, a high level of p53 expression was detected after 12, 24, 48, 72 and 96 h in OV-MZ-2a cells. At a m.o.i of 20, 96% and 90% growth inhibition were achieved in OV-MZ-2a cells and OV-MZ-32 cells respectively. Clonogenicity was lost completely in both cell lines following wild-type p53 transfer. Meanwhile, Ad-p53 gene transfer combined with taxol, cisplatin, doxorubicin or mitomycin C was shown to be even more effective in suppressing growth in the two cell lines.

CONCLUSIONS

Our results may suggest that wild-type p53 gene transfer mediated by an adenoviral vector is a potential strategy for treating ovarian cancer, and a combination of Ad-p53 gene transfer and chemotherapeutic agents may be an even better treatment of the cancer.

p53 autoantibodies in patients with primary ovarian cancer are associated with higher age, advanced stage and a higher proportion of p53-positive tumor cells

Autoantibodies (AAb) directed against the nuclear phosphoprotein p53 can be detected in patients with various forms of cancer. The objective was to determine the prevalence of p53 AAb at the time of diagnosis in ovarian cancer patients and to correlate the presence of p53 AAb with clinicopathological parameters. Sera of 83 patients were analyzed by an ELISA using p53 expressed from a human wild-type cDNA. p53 AAb were detectable at all stages. The overall prevalence was 46%. p53 AAb were more frequent in patients with higher age (p = 0.014), postmenopausal status (p = 0.050), or advanced tumor stage (p = 0.046). p53 AAb positivity was related to the proportion of cells positive in immunohistochemistry but not with the staining intensity. In bivariate analysis, patients with p53 AAb had a 1.96-fold risk for relapse (95% confidence interval 1.02-3.78).

Serum p53 autoantibodies in patients with minimal lesions of ductal carcinoma in situ of the breast

Five of 43 patients (11.6%) with ductal carcinoma in situ of the breast presented with p53 autoantibodies at diagnosis. Three seropositive patients demonstrated tumour sizes of < or = 5 mm. There was no association of p53 autoantibody status with age, clinical presentation, histological subtype, tumour size, grading, p53 immunohistochemistry or hormone receptor status.

Intron variants of the p53 gene are associated with increased risk for ovarian cancer but not in carriers of BRCA1 or BRCA2 germline mutations

Two biallelic polymorphisms in introns 3 and 6 of the p53 gene were analysed for a possible risk-modifying effect for ovarian cancer. Germline DNA was genotyped from 310 German Caucasian ovarian cancer patients and 364 healthy controls. We also typed 124 affected and 276 unaffected female carriers with known deleterious BRCA1 or BRCA2 germline mutation from high-risk breast-ovarian cancer families. Genotyping was based on PCR and high-resolution gel electrophoresis. German ovarian cancer patients who carried the rare allele of the MspI restriction fragment length polymorphism (RELP) in intron 6 were found to have an overall 1.93-fold increased risk (95% confidence internal (CI) 1.27-2.91) which further increased with the age at diagnosis of 41-60 years (odds ratio (OR) 2.71, 95% CI 1.10-6.71 for 41-50 and OR 2.44, 95% CI 1.12-5.28 for 51-60). The 16 bp duplication polymorphism in intron 3 was in a strong linkage to the MspI RFLP. In BRCA1 or BRCA2 mutation carriers, no difference in allele frequency was observed for carriers affected or unaffected with ovarian cancer. Our data suggest that intronic polymorphisms of the p53 gene modify the risk for ovarian cancer patients but not in carriers with BRCA1 or BRCA2 mutations.

Intrauterine resuscitation by rapid urinary bladder instillation in a case of occult prolapse of an excessively long umbilical cord

Occult umbilical cord prolapse is a dramatic obstetrical emergency jeopardizing health and life of the fetus. Distending the maternal urinary bladder provides alleviation of pressure on the cord by reducing uterine contractions and by maintaining fetal structures elevated in order to protect the fetus from asphyxia until Cesarean delivery.

p53 mutations and expression in ovarian cancers: correlation with overall survival

The p53 gene is altered in approximately 50% of all human malignancies. p53 overexpression, identified by immunohistochemistry, and p53 mutations, identified by single-strand conformational polymorphism (SSCP) and DNA sequencing, have been described in ovarian cancers. p53 overexpression has been correlated with poor outcome for women with ovarian cancer in some studies. With only limited data, the assumption has been made that p53 overexpression corresponds to p53 mutations. The purpose of this investigation was to assess p53 alterations in ovarian cancer to determine if p53 overexpression corresponds with mutations in the p53 gene, and to assess whether either predicts clinical outcome in ovarian carcinoma. Frozen ovarian carcinoma tumor specimens from 105 patients were analyzed by immunohistochemical staining for p53 expression. SSCP was used to screen for mutations and DNA sequencing was used to confirm the specific mutation in exons 2 to 11, encompassing the entire p53 open reading frame. Those ovarian carcinomas identified as wild-type p53 by SSCP were subjected to automated DNA sequence analysis of the entire open reading frame. Relative to DNA sequence analysis, the sensitivity of SSCP was 85% and the specificity was 98%. Immunohistochemical staining demonstrated that 72 of the 105 (69%) cases had positive immunostaining. SSCP and DNA sequencing identified and confirmed mutations in 60 of the 105 carcinomas (57%). Although there was a statistically significant association between p53 immunostaining and p53 mutations (p = 0.0002), false-negative and -positive results were identified. Tumor grade (p = 0.03), stage (p = 0.08), and overall survival (p = 0.15) were moderately associated with positive p53 immunostaining. Patients with p53 mutations and overexpression had shorter overall patient survival (p = 0.02). The findings demonstrated that, individually, p53 mutations and p53 overexpression were each related to shorter patient survival, but the strongest predictor of outcome was a combination of both mutations and overexpression. Comparisons of overall survival for women with mutations in loop 2, loop 3, and the loop-sheet-helix domains together showed a statistically significant difference in survival compared to survival of women whose ovarian cancers had other mutations (p = 0.046).

Pregnancy outcome after repeated blunt abdominal trauma

During a four-year period, five of 49671 parturients were admitted on a prospective study protocol for repeated direct blunt abdominal trauma due to falls during pregnancy. Preterm contractions were noted in three patients one of which delivered preterm. No delayed abruptio placentae, intrauterine growth restriction or antepartum death were encountered. All patients delivered spontaneously. Repeated blunt abdominal trauma occurs rarely in pregnancy. Routine hospitalised surveillance in the absence of vaginal bleeding or uterine contractions may not be warranted.

Differential characteristics of two new tumorigenic cell lines of human breast carcinoma origin

Permanent human tumor cell lines are an important tool for the study of breast cancer. Two new breast cancer cell lines (BrCa-MZ-01 and BrCa-MZ-02) were isolated from a solid tumor and a pleural effusion, respectively. One cell line was established from a medullary carcinoma, the other from a ductal carcinoma. These cells exhibit ultrastructural and immunohistochemical features of epithelial cells of mammary origin. Intermediate filament and cytokeratin typing showed a clear predominance of the simple-epithelial cytokeratins CK 8, CK 18 and CK 19, although the expression was reduced in comparison to the hormone receptor-positive reference cell lines MCF-7 and ZR-75-1. Both cell lines produced slow-growing tumors after subcutaneous (s.c.) transplantation of 1 x 10(7) viable tumor cells into nude mice. The cell line BrCa-MZ-01 expresses the estrogen and progesterone receptor, whereas the cell line BrCa-MZ-02 remains negative. Both cell lines are positive for secretion of platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta), whereas interleukin-6 (IL-6) is only secreted by the cell line BrCa-MZ-02.

p53 germline polymorphisms are associated with an increased risk for breast cancer in German women

Three germline p53 polymorphisms, a 16 bp duplication in intron 3, a Bst UI RFLP in exon 4 and Msp I RFLP in intron 6 have previously been tested for a association with Swedish breast cancer patients. The rare Bst UI allele was found to be associated with breast cancer in the Swedish patients (OR 1.47, 95% CI, 1.08-2.00). In our hospital-based case-control study leukocyte DNA of 107 breast cancer patients and 305 control women was analyzed. Individuals heterozygous at all 3 polymorphic sites (27/107) were over-represented in the breast cancer group with an age-adjusted OR of 2.01 (95% CI, 1.02-3.94). Haplotype analysis identified the 16 bp A2 allele (with 16 bp duplication) and Msp I A1 allele (loss of Msp I restriction site) as risk alleles. The results of this study suggest that the rare alleles 16 bp A 2 and Msp I A1 of the p53 locus may modify the risk of breast cancer in German women.

Telomere length in human white blood cells remains constant with age and is shorter in breast cancer patients

BACKGROUND

Telomeres, which are TTAGGG repeats at the end of the eukaryotic chromosome, are essential for complete DNA replication. Telomere length has been reported to decrease in peripheral WBC, unlike the telomerase activity found in these cells. The purpose of this study was to investigate whether telomere length in WBC is indeed age dependent and could serve as a genetic marker in breast or ovarian cancer.

METHODS

Five age groups: 20-29; 30-39; 4049; 50-59 and > or = 60 years were examined. The cancer patients were 18 women with ovarian cancer and 18 women with breast cancer. Southern blot analysis of the DNA from peripheral white blood cells (WBC) was performed using 32P-labeled (TTAGGG)3 probe. Blots were scanned in a phosphoimager and analyzed by computer-assisted image analysis.

RESULTS

No statistically significant correlation was observed between telomere length and age in either healthy females or cancer patients. However, significantly shorter median telomere length was found in WBC obtained from breast cancer patients as compared to healthy individuals and ovarian cancer patients.

CONCLUSIONS

It is concluded that telomere length in WBC is not age dependent, but is significantly shorter in breast cancer patients.

Genomic semi-automated cycle sequencing as a sensitive screening technique for p53 mutations in frozen tumor samples

Single-strand conformational polymorphism (SSCP) is the most widely used method for p53 gene mutation screening. Nucleotide sequence analysis is considered more sensitive for detection of mutations. We established a genomic semi-automated cycle sequencing protocol suitable for p53 gene mutation screening. The technique was applied to 44 SSCP-negative frozen ovarian cancer samples: Eleven mutations (11/44, 25%) were found, 6 point missense mutations, 3 silent point mutations, 1 nonsense mutation and 1 single-base deletion. Heterozygous mutations were readily detectable. Genomic semi-automated cycle sequencing is a sensitive, time-effective screening method requiring only small amounts of tumor tissue.

Intron 9 retention in gene transcripts suggests involvement of CD44 in the tumorigenesis of ovarian cancer

Increased or de novo expression of certain CD44 variant isofoms as well as abnormal processing of pre-mRNA of the CD44 gene have been found in different malignant human tumors. Retention of the non-coding intron 9 sequence in CD44 mRNA especially, appears to be a discriminating aberrant splicing pattern in several cancer tissues and cells. We examined the expression of the CD44 intron 9 sequence in the mRNA of 45 permanent ovarian cancer cell lines and in normal ovarian tissue. Abnormal retention of intron 9 was found in 19 (60%) cell lines expressing CD44 std. Normal ovarian tissue as well as all ovarian cancer cells without CD44 s t d expression were found to be negative for intron 9 retention. Our results indicate that besides newly acquired expression of certain CD44 isoforms abnormal retention of the non-coding intron 9 sequence in CD44 gene transcripts is also a common and maybe crucial event in the tumorigenesis of ovarian cancer. Since intron 9 is not retained in normal ovarian tissue this aberration might serve as a marker for human adenocarcinoma of the ovary.