Biomedical subjects

T Bauknecht

Publications and source records attributed to T Bauknecht.

At least 37 records · Page 2Linked to original sources

PubMed1997

Phase I/II study of the combination of carboplatin and paclitaxel as first-line chemotherapy in patients with advanced epithelial ovarian cancer.

PURPOSE: We performed a phase I/II study evaluating the combination of paclitaxel and carboplatin as first-line chemotherapy in patients with advanced ovarian cancer. The aim of this study was to define a feasible and safe combination regimen that could be recommended for future phase III studies. DESIGN: This study was a parallel two-arm, non-randomized, open trial. In a first step, carboplatin was administered at a fixed dose of AUC 5 and paclitaxel was escalated in 25 mg/ m2 steps starting at 135 mg/m2. Paclitaxel was given as a three-hour infusion. Carboplatin was administered on day 1 following paclitaxel in one study arm and 24 hours after paclitaxel infusion on day 2 in the other study arm. Carboplatin was escalated to AUC 6 and AUC 7.5 after the MTD for paclitaxel had been defined. Treatment was repeated every three weeks. PATIENTS: Sixty-one patients with untreated histologically confirmed epithelial ovarian cancer were recruited of whom 59 were found eligible and evaluable for toxicity. Thirty-three patients with bidimensionally measurable disease were evaluable for tumor response. RESULTS: We could not detect any advantage of the two-day schedule compared with the more convenient one-day schedule. Dose limiting toxicities were neutropenia, thrombocytopenia, and neurotoxicity. Except for two patients, toxicity was acceptable and clinically managable. One patient died of neutropenic sepsis and one further patient developed grade III peripheral neurotoxicity that did not resolve within two months after chemotherapy had been terminated. Overall objective response rate was 70%. The MTD for paclitaxel was 185 mg/m2 and AUC 6 for carboplatin, respectively. Secondary prophylaxis with G-CSF did not allow further dose escalation and therefore is not generally recommended. CONCLUSIONS: Paclitaxel 185 mg/m2 given as three-hour infusion followed by carboplatin AUC 6 is a feasible and safe regimen and can be recommended for phase III trials. Observed response rates justify further evaluation of this combination. A randomized phase III trial comparing a three-hour infusion of paclitaxel 185 mg/m2 combined with either carboplatin AUC 6 or cisplatin 75 mg/m2 as first-line chemotherapy of advanced ovarian cancer has recently been initiated by our group.

Adult↗

PubMed1997

Paclitaxel combined with carboplatin in the first-line treatment of advanced ovarian cancer: a phase I trial.

Recently, a randomized study conducted by the Gynecologic Oncology Group (GOG 111) demonstrated that, given by a 24-hour infusion, the combination of cisplatin and paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) is superior to combination cisplatin/cyclophosphamide in previously untreated patients with advanced ovarian cancer. This combination, however, necessitates hospitalization. Combination paclitaxel/carboplatin would be expected to induce fewer nonhematologic side effects but may be more myelotoxic. Thus, we started a phase I dose-escalation study to determine the maximal tolerated dose of paclitaxel given as a 3-hour infusion in combination with carboplatin, both drugs administered every 21 days. The paclitaxel dose was escalated by increments of 25 mg/m2, starting at 135 mg/m2 (level 1), 160 mg/m2 (level 2), 185 mg/m2 (level 3), and 210 mg/m2 (level 4). Carboplatin was administered to achieve an area under the concentration-time curve of 5, using the Calvert formula For study levels 5 and 6, the carboplatin dose was targeted at area under the concentration-time curves of 6 and 7.5, respectively, and was combined with a fixed paclitaxel dose of 185 mg/m2. Thirty previously untreated patients with stage IIC to IV ovarian cancer were enrolled. Nonhematologic toxicity, including nausea/vomiting and arthralgia/myalgia, was mild. Across all dose levels, a total of 16 patients developed peripheral neurotoxicity (World Health Organization grades 1 and 2). At dose level 5, one patient experienced reversible grade 4 neurotoxicity. Neutropenia was the principal dose-limiting hematologic toxicity. During 33 (31%) of 106 courses, World Health Organization grade 4 neutropenia was observed. Granulocyte colony-stimulating factor was required in only 7.6% of courses. Thrombocytopenia was less than that expected when carboplatin is given alone. Clinical responses were observed in eight of 14 patients, for an overall response rate of 57%. The combination of carboplatin plus paclitaxel was found to be an active regimen. This trial demonstrates that carboplatin dosed by the Calvert equation and 3-hour paclitaxel can be combined safely at full therapeutic doses for six or more courses in patients with advanced epithelial ovarian cancer.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1997

Carboplatin plus paclitaxel as first-line chemotherapy in previously untreated advanced ovarian cancer. German AGO Study Group Ovarian Cancer. Arbeitsgemeinschaft Gynäkologische Onkologie.

Since publication of the results of the Gynecologic Oncology Group (GOG) III study, the combination of cisplatin and paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) has been adopted widely as the new standard for treating advanced ovarian cancer. Further attempts to optimize first-line chemotherapy with platinum and taxanes include substituting carboplatin for cisplatin, individualizing the carboplatin dose by calculating it according to the area under the concentration-time curve, and reducing the length of the paclitaxel infusion. Attempts to optimize platinum/paclitaxel combinations have led to the initiation of several small phase I/II trials evaluating the carboplatin/paclitaxel combination. The promising results of these studies have prompted the initiation of three phase III trials comparing carboplatin/paclitaxel with the standard combination of cisplatin/paclitaxel. An interim analysis after 1 year's accrual to the prospectively randomized German Arbeitsgemeinschaft Gynäkologische Onkologie (AGO) study is presented. Treatment consists of paclitaxel 185 mg/m2 infused over 3 hours on day 1 followed directly by either cisplatin 75 mg/m2 (arm B) or carboplatin dosed to an area under the curve of 6 (arm A). Treatment is repeated every 3 weeks for six courses. Eligibility criteria are epithelial ovarian cancer International Federation of Gynecology and Obstetrics stage IIB through IV, age of consent, written informed consent, Eastern Cooperative Oncology Group performance status < or =2, life expectancy of more than 12 weeks, adequate bone marrow function defined as neutrophil count 1.5 x 10(9)/L and platelet count > or =100 x 10(9)/L, adequate renal function defined as glomerular filtration rate (GFR) > or =60 mL/min, and adequate liver function defined as serum bilirubin levels within 1.25 x upper limit of normal. From October 1995 to December 1996, 442 of 660 planned patients were recruited to the AGO study. The interim analysis is based on data from 353 patients who were enrolled within the first study year. These preliminary data indicate that hematologic toxicity occurred more frequently in arm A (carboplatin/paclitaxel), while nonhematologic toxicity occurred slightly more frequently in arm B. Dose-intensity analysis did not reveal cumulative dose reductions or increasing use of colony-stimulating factors over subsequent courses in either arm. In all, 44 patients with measurable disease following surgery completed chemotherapy and were evaluable for response. The data remain blinded at this time, and results are reported for the group as a whole. So far, there have been 18 (41%) complete responses and 15 (34%) partial responses, for an overall response rate of 75%. Retrospective comparison with the GOG results reveals no significant difference in response rates between patients in the cisplatin/paclitaxel arm of GOG III and those in the AGO study: the GOG study reported a 73% response rate, compared with a preliminary 75% response rate in the AGO study, resulting in a relative risk of 1.03 (95% confidence interval, 0.83 to 1.27). Overall, this interim analysis did not reveal any reason to terminate this study early. Accrual is ongoing and is expected to be completed in 1997.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1997

Carboplatin/paclitaxel versus cisplatin/paclitaxel as first-line chemotherapy in advanced ovarian cancer: an interim analysis of a randomized phase III trial of the Arbeitsgemeinschaft Gynäkologische Onkologie Ovarian Cancer Study Group.

Since publication of the results of the Gynecologic Oncology Group III study, the combination of cisplatin/paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) has been widely adopted as standard treatment for advanced ovarian cancer. Further attempts to optimize first-line chemotherapy with platinum and taxanes include the substitution of cisplatin with carboplatin, individualization of the carboplatin dose by calculating it according to the area under the concentration-time curve, and reduction of paclitaxel infusion duration. These attempts have led to the initiation of several phase I/II trials evaluating the combination of carboplatin/paclitaxel. The promising results of these small studies have prompted the initiation of three phase III trials comparing carboplatin/paclitaxel with the standard combination of cisplatin/paclitaxel. The interim analysis after 15 months' accrual of the prospectively randomized German Arbeitsgemeinschaft Gynäkologische Onkologie (AGO) study is presented here. As of January 1997, 518 of 660 planned patients have been recruited. The interim analysis is based on data from 449 evaluable patients. The preliminary data indicate that hematologic toxicity occurred more frequently in arm A (carboplatin/paclitaxel), whereas nonhematologic toxicity occurred slightly more frequently in arm B (cisplatin/paclitaxel). Dose-intensity analysis did not reveal cumulative dose reductions or an increased need for colony-stimulating factors over subsequent courses in both arms. Forty-four patients with measurable disease following surgery completed chemotherapy and were evaluable for response, which remains blinded at this time and is reported for the group as a whole. So far, there have been 18 complete responses (41%) and 15 partial responses (34%), for an overall response rate of 75%. Retrospective comparison reveals no significant difference in response rates between patients in the cisplatin/paclitaxel arm of Gynecologic Oncology Group III and those in the Arbeitsgemeinschaft Gynäkologische Onkologie study. Overall, this interim analysis did not reveal any reason for an early termination of this study. Accrual is ongoing and is expected to be completed this year.

Antineoplastic Agents↗

PubMed1997

Phase I study of paclitaxel administered as a 1-hour infusion: toxicity and pharmacokinetics.

Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) is one of the most important new drugs used in the treatment of solid tumors. Use of paclitaxel, however, is associated with some toxicity. The main adverse side effects include myelotoxicity, neurotoxicity, hypersensitivity reactions, and asthenia. Toxicity seems to be schedule dependent. Currently, paclitaxel is routinely administered via 3- or 24-hour infusions. This study was performed to evaluate the toxicity and pharmacokinetics of a 1-hour infusion. Thirty-four patients with incurable solid tumors were included. Dose levels were escalated from 150 to 250 mg/m2. Thirty-four patients received a total of 105 courses of paclitaxel. The dose-limiting toxicity was World Health Organization grade 3 neuropathy at a dose of 250 mg/m2 in two of three patients. Two patients were not evaluable for dose-limiting toxicity because treatment was stopped after fewer than three courses due to disease progression. Neither had experienced a dose-limiting toxicity. Other toxicities were World Health Organization grade 1/2 neutropenia, asthenia, myalgia, arthralgia, and grade 1 hypersensitivity. Twenty-one patients were evaluable for preliminary anticancer efficacy. A partial response was observed in five patients (24%), stable disease in three (14%), and progressive disease in 13 (62%). The maximum tolerated dose was established at 250 mg/m2. A dose of 225 mg/m2 is recommended for further phase II trials. There was considerable interindividual and some intraindividual variability in pharmacokinetic parameters. Paclitaxel pharmacokinetics were linear up to 225 mg/m2, while a slightly overproportional increase in the peak plasma concentration and the area under the concentration-time curve was observed at 250 mg/m2, suggesting that paclitaxel's pharmacokinetic characteristics may be nonlinear at higher doses.

Adolescent↗

PubMed1996

Increasing incidence of CD44v7/8 epitope expression during uterine cervical carcinogenesis.

Splice variants of the cell surface glycoprotein CD44 (CD44v) have been implicated in the progression of various human tumors. In the present study, we have examined the expression pattern of a CD44v epitope encoded by the adjacent variant exons v7 and v8 during human cervical carcinogenesis. While only l/ll normal cervical squamous epithelia was positive for this epitope by immunohistochemistry, 4/21 samples of low-grade squamous intra-epithelial lesions (LSIL), 17/35 samples of high-grade squamous intra-epithelial lesions (HSIL), 11/12 samples of the HSIL subgroup of carcinomas in situ and 17/17 cases of invasive cervical carcinoma showed CD44v7/8 epitope expression. In addition to CD44 variant expression, we have analyzed 67 lesions for the presence of HPV16/18-DNA using PCR. Most of the samples expressing the v7/8 epitope were also HPV16-positive (29/32), whereas only 17/35 of the v7/8-negative samples were HPV16-positive. HPV18 DNA was found in only one invasive carcinoma. Our data suggests that high-risk HPV infection may precede CD44v7/8 expression and that the number of samples expressing the CD44v7/8 epitope increases during carcinogenesis and reaches nearly 100% at the carcinoma in situ stage. This CD44 epitope could, therefore, serve as a diagnostic marker of cervical squamous cell carcinomas and as a possible target for CD44v7/8 epitope-directed therapies.

Alternative Splicing↗

PubMed1996

Overrepresentation of 3q and 8q material and loss of 18q material are recurrent findings in advanced human ovarian cancer.

In order to define the ability of comparative genomic hybridization (CGH) to detect and map genetic imbalances, we investigated 47 malignant ovarian tumors and 2 ovarian tumors of low malignant potential. The most common genetic changes in order of frequency included DNA gains of chromosome arms 8q (53%), 3q (51%), 20q (43%), 1p (32%), 19q (30%), 1q (28%), 12p (28%), 6p (21%), and 2q (19%). The smallest regions of overrepresentation could be defined in 3q26-qter, 8q23-qter, 1p35-pter, 12p 12, and 6p21-22, respectively. Losses were detected on 18q (23%), chromosome 4 (23%), 13q (17%), and 16q (17%) with the smallest underrepresented regions on 18q22-qter, 13q21, and 16q23-qter. Also, losses of the X chromosome (19%) were detected, correlating with higher ages of the patients. Therefore, some of these X chromosome losses might be due to a well-known aging phenomenon and in these cases will be more preferably lost during cell division and tumor progression. Our findings show that ovarian carcinomas reveal consistent chromosomal abnormalities. Further detailed studies of these regions with specific molecular genetic techniques may lead to the identification of oncogenes and/or tumor suppressor genes playing an important role in the tumorigenesis of ovarian carcinomas.

Adult↗

PubMed1996

[Changes in serotonin metabolism in pre-eclampsia].

Several complications of pregnancy have been reported to be associated with alterations of serotonin (5-HT). This study describes the changes in 5-HT metabolism in patients with preeclampsia. Our examination findings should explain if there are elevated 5-HT and 5-HIAA concentrations in urine and serum of women with preeclampsia. On the other hand it should be proved if the observed chances are due to a decreased kidney function and if there is an important prognostic factor to detect asymptomatic preeclamptic patients. 5-HT and its main metabolite 5-hydroxy-indol-acetic acid (5-HIAA) was evaluated in serum and urine of 24 pregnant women with preeclampsia and of 27 pregnant women without preeclampsia in the last month of pregnancy, within 24 hours after delivery and at the fourth day post partum. Besides 5-HIAA was ascertained in 24-h urine from the 24th week of pregnancy until after delivery. 5-HIAA excretion increased continuously during pregnancy independently of whether the patients developed preeclampsia. A significant less increase and lower concentration of 5-HIAA pre and post partum were observed in preeclamptic patients when compared to non-preeclamptic patients. We noticed a remarkably lower 5-HIAA excretion and a higher concentration of 5-HT in women with preeclampsia. Preeclamptic patients demonstrate a lower decrease of 5-HIAA and a significantly greater increase of 5-HT than women without preeclampsia. These results could be explained by a decreased metabolism of 5-HT due to the placental MAO. The changes observed in our study are not due to a decreased kidney function because creatinine concentrations in women with and without preeclampsia were comparable. Our results indicate that 5-HIAA-/creatinine ratio might be an important prognostic factor.

Adult↗

PubMed1996

A novel C/EBP beta-YY1 complex controls the cell-type-specific activity of the human papillomavirus type 18 upstream regulatory region.

The human papillomavirus type 18 (HPV-18) upstream regulatory region (URR) controls viral gene transcription in a cell-type-specific manner. The HPV-18 URR is active in HeLa cells but inactive in HepG2 cells. The activating activity of YY1 in HeLa cells is dependent on its functional interactions with the switch region which is critical for the HPV-18 URR activity in HeLa cells. Here, we show that a protein complex composed of C/EBP beta and YY1 binds the switch region which is detected only in HeLa cells, not in HepG2 cells. Transfection of C/EBP beta into HepG2 cells restored the formation of the C/EBP beta-YY1-switch region complex, accompanied by increased transcription directed by the HPV-18 URR. Mutations in the switch region that abolished the complex formation also abrogated C/EBP beta-induced transcriptional activation. This provides a strong correlation between the binding of the C/EBP beta-YY1 complex to the switch region and cell-type-specific URR activity. Taken together, we have identified a novel C/EBP beta-YY1 complex that binds the switch region and contributes to cell-type-specific HPV-18 URR activity.

CCAAT-Enhancer-Binding Proteins↗

PubMed1996

Activity of the DNA repair protein O6-methylguanine-DNA methyltransferase in human tumor and corresponding normal tissue.

The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) is a main determinant of resistance of cells towards the cytostatic effect of N-nitrosoureas. Here we report the activity of MGMT in different types of human tumors. Colorectal tumors showed the highest mean of MGMT activity (481 +/- 258 fmol/mg protein) followed by ovarian tumors (437 +/- 291 fmol/mg), breast (306 +/- 204 fmol/mg), testicular (299 +/- 179 fmol/mg), and brain tumors (55 +/- 44 fmol/mg). Only in breast and brain tumors were MGMT-deficient samples found, with a frequency of 3 and 5%, respectively. No significant difference in mean MGMT activity was observed between breast tumors of grading I, II, and III. For brain tumors there was a tendency of MGMT to decline with increasing grading. Breast and colorectal carcinomas were compared with the corresponding normal tissue obtained from the same patient. The data showed for 11 out of 12 pairs of breast tissue and for 13 out of 15 pairs of colorectal tissue that MGMT activity in the tumor was equal to or, more frequently, higher than the activity found in the corresponding normal tissue. Thus, it appears that in these groups of tumors, increase of MGMT activity during tumor formation and progression is the rule rather than the exception.

Brain Neoplasms↗

PubMed1995

c-jun expression and growth stimulation in human ovarian carcinoma cell lines following exposure to cytokines.

We evaluated the effects of recombinant human G-CSF, rhGM-CSF, rhM-CSF and rhIL-1 alpha on proliferation and regulation of c-jun gene expression in 4 human ovarian-carcinoma (HOC) cell lines, NIH:OVCAR-3, SK-OV-3, HEY and BG-1, and in one primary ovarian tumor in vitro. The cytokines were administered in concentrations of 0.1 U/ml to 1000 U/ml. Cell growth was measured by crystal-violet- and thiazolyl-blue(MTT)-based cell counts. c-jun transcripts were measured by the solution hybridization/RNAse protection assay. RhM-CSF and rhGM-CSF showed no growth stimulation of any of the 5 cell lines tested. Results from exposure to rhG-CSF were different. The cell lines NIH:OVCAR-3, SK-OV-3, BG-1 and the primary ovarian tumor showed no proliferative response. A 2- to 3-fold increase in proliferation was observed in the HEY HOC cell line. rhIL-1 alpha led to growth stimulation in the BG-1 cell line, but showed an inhibitory effect in the NIH:OVCAR-3 cells. No effects of rhIL-1 alpha were observed in the remaining 2 cell lines nor in the primary ovarian tumor. Growth stimulation was accompanied by an increase in c-jun expression in the HEY cell line, and the BG-1 cell line. No alterations in c-jun expression were observed in the remaining 3 cell lines. Our results indicate that rhG-CSF or rhIL-1 alpha influence cell proliferation in 2 out of 5 human ovarian-tumor cell lines, accompanied by an increase in c-jun expression.

Cell Division↗

PubMed1995

p53 mutation and MDM2 amplification are rare even in human papillomavirus-negative cervical carcinomas.

BACKGROUND: Mutation of the p53 tumor suppressor gene is the most commonly found genetic alteration in human cancer. The E6 gene product of human papillomavirus (HPV) 16 and 18 can inactivate the p53 protein by promoting its degradation. Because most HPV-positive cervical carcinoma cell lines contain wild-type p53 whereas HPV-negative cell lines have point mutations in the p53 gene, a major role in the development of HPV-negative cervical cancer has been attributed to p53. Recent studies, however, have observed no consistent presence of p53 mutation in HPV-negative primary cervical carcinomas. The MDM2 oncogene, which forms an autoregulatory loop with the wild-type p53 protein, has been found amplified in a high percentage of human sarcomas, thus abolishing the antiproliferative function of p53. METHODS: Forty-three primary cervical carcinomas and 10 autopsy-derived distant metastases from one patient were examined for p53 mutation and MDM2 amplification. These tumors had been selected from 238 cervical cancers that had been HPV-typed by Southern blot hybridization and polymerase chain reaction as a representative sample for their HPV status and their clinicopathologic characteristics. Seventeen of the cases had a remarkably good or poor clinical outcome. Human papillomavirus DNA sequences had been detected in 30 of these 43 primary tumors and 13 were negative for HPV by both methods. p53 mutation in the highly conserved exons 5-8 was studied by single-strand conformation polymorphism analysis and direct sequencing. MDM2 amplification was analyzed by Southern blot hybridization. RESULTS: Only two missense point mutations and one nucleotide sequence polymorphism were detected: a TAC-->TGC transition in codon 234 in exon 7, resulting in a Tyr-->Lys substitution, a CGT-->TGT transition in codon 273 in exon 8, resulting in an Arg-->Cys substitution and a polymorphism (CGA-->CGG) in codon 213 in exon 6. Both tumors revealing the point mutations were HPV-negative carcinomas. Amplification of the MDM2 gene was observed in 1 of the 53 specimens tested. CONCLUSIONS: In contrast to data derived from cultured cervical carcinoma cell lines and primary sarcomas, these results indicate that p53 mutation and amplification of the MDM2 oncogene are rare even in HPV-negative primary cervical carcinomas. However, to the authors; knowledge, this is the first observation of MDM2 amplification in humans outside sarcomas and neuroepithelial tumors.

Adult↗

PubMed1995

Transcriptional control of human papillomavirus type 18 oncogene expression in different cell lines: role of transcription factor YY1.

Binding of YY1 to the proximal fragment of the human papillomavirus type 18 (HPV-18) upstream regulatory region (URR) activates the oncogene expression of HPV-18 in HeLa cells, whereas in HepG2 cells this expression is repressed by YY1. In the present transient transfection study, we analyze the regulation of the HPV-18 URR by YY1 in an extended number of cell lines. Except for HeLa cells, YY1 represses or does not influence oncogene expression in all cell lines tested. In HeLa cells the activation of viral oncogene expression by YY1 is caused by the functional interplay between YY1 and a factor binding to the newly identified "switch region" of the HPV-18 URR. In this work we show that in HeLa cells, a 22 bp region located between the "switch region" and the promoter proximal fragment contributes to the modulation of the activity of YY1 and, in addition, regulates HPV-18 promoter activity independently of YY1.

Base Sequence↗

PubMed1995

[Effect of pregnancy and labor on serotonin metabolism].

Several complications of pregnancy have been reported to be associated with alterations of serotonin (5-hydroxytryptamine; 5-HT) metabolism. Reported data regarding changes of 5-HT metabolism in pregnancy are partially contradictory. The presented study tries to describe pregnancy-associated changes in 5-HT metabolism. Urine and blood samples were taken from 20 pregnant women 4 weeks before, within 24 hours and on the 4th day following delivery. 17 non-pregnant age-matched women served as controls. 5-HT and its main metabolite 5-hydroxyindoleacetic acid (5-HIAA) were analysed. We observed a continuously increasing production and excretion of unbound 5-HT and 5-HIAA during pregnancy. Four days after delivery 5-HT production returned to baseline levels, while excretion remained elevated. 5-HIAA excretion increased in pregnancy and return to baseline levels on the day following delivery. Increased 5-HT metabolism and excretion results in a decreased 5-HT serum concentration despite increased 5-HT production during pregnancy. Our results help to understand the contradictory observations of elevated 5-HT production on the one hand and decreased 5-HT activity during pregnancy on the other.

Adult↗

PubMed1995

A switch region determines the cell type-specific positive or negative action of YY1 on the activity of the human papillomavirus type 18 promoter.

YY1 is a zinc finger transcription factor which acts as either a repressor or an activator dependent on the promoter context. YY1 is a potent activator of the genuine human papillomavirus type 18 (HPV-18) upstream regulatory region (URR) in HeLa cells, which are known for high-level expression of the HPV-18 early genes. The activating activity of YY1 is dependent on the presence of a newly identified switch region located upstream of the YY1 binding site. Deletion of this region causes YY1 to act as a repressor of HPV-18 promoter activity. In vivo footprinting of the HPV-18 URR and an in vitro electrophoretic mobility shift assay identified proteins binding to the switch region. Site-directed mutagenesis of the switch region and YY1 binding sites suggests that these two regions work in concert to yield high-level HPV-18 URR activity in HeLa cells but not in HepG2 cells, where HPV-18 is almost inactive. These data identified a novel mode of cell type-specific regulation of HPV-18 promoter activity by positive or negative action of YY1, determined by the switch region binding factor(s).

Base Sequence↗

PubMed1995

Recurrent cytogenetic aberrations in human ovarian carcinomas.

Successful cytogenetic analysis was performed on short-term cultures of 62 malignant ovarian tumors from 42 patients. Twenty-three tumors from 18 patients revealed clonal chromosome abnormalities. Five cases showed nonclonal chromosome changes. In the remaining 19 cases, a normal female karyotype was found. Numerical or single structural changes were found in only 11 carcinomas from nine patients. Trisomy 12 and 7 were each the sole abnormality in two cases a piece. One tumor showed a trisomy 6 as the only karyotypic change. Four tumors revealed simple translocations and deletions affecting the chromosomes X, 1, 2, 6, and 7. Twelve of the cytogenetically abnormal tumor samples showed complex karyotypes with both numerical and structural aberrations leading to hyperdiploid, near-triploid, and near-tetraploid stemlines. The recurrent numerical imbalances were losses of the chromosomes 1 (N = 5), X (N = 3), and 17 (N = 3), and gains of the chromosomes 12 (N = 5) and 20 (N = 3). Regarding structural rearrangements, the chromosome bands 11p13-14 and 19p13 were the most frequently affected regions. 11p13-14 was rearranged in four tumors. In two cases, a deletion 11p13-14 was found. Two tumors revealed a nonreciprocal translocation involving 11p13-14 and leading to the loss of distal 11p material. The most consistent finding was a 19p+ marker chromosome, which was present in five different ovarian carcinomas. Our results are in accordance with a recent cytogenetic report describing a 19p+ marker and loss of 11p material as consistent cytogenetic aberrations in human ovarian carcinomas.

Adenocarcinoma↗

PubMed1995

Paclitaxel combined with carboplatin in the first-line treatment of advanced ovarian cancer.

In a phase I study to determine the maximum tolerated dose of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) given as a 3-hour infusion in combination with carboplatin administered every 21 days to women with advanced ovarian cancer, paclitaxel doses were escalated as follows: level 1, 135 mg/m2; level 2, 160 mg/m2; level 3, 185 mg/m2; and level 4,210 mg/m2. The fixed dose of carboplatin at levels 1 through 4 was given to achieve an area under the concentration-time curve (AUC) of 5 using the Calvert formula. In levels 5 and 6 the carboplatin dose was targeted at AUCs of 6 and 7.5, respectively, combined with a fixed paclitaxel dose of 185 mg/m2. To date, 30 previously untreated patients, all with a good performance status (Eastern Cooperative Oncology Group 0 to 2) have been entered into this ongoing study. The dose-limiting toxicity of the combination was myelosuppression (leukopenia, granulocytopenia, and thrombocytopenia). Neurotoxicity was largely moderate. So far, 14 patients are evaluable for response; of these, eight (57%) showed objective (complete or partial) response and disease stabilized in six patients. No patient had disease progression. We conclude that the combination of paclitaxel 185 mg/m2 administered as a 3-hour infusion followed immediately by a 1-hour infusion of carboplatin at an AUC of 6 can be administered safely in a 21-day schedule in the outpatient setting. The recommended dose for phase III studies is paclitaxel 185 mg/m2 and carboplatin AUC 6.

Adult↗

PubMed1994

Co-expression of M-CSF transcripts and protein, FMS (M-CSF receptor) transcripts and protein, and steroid receptor content in adenocarcinomas of the ovary.

The co-expression of M-CSF (CSF-1) and its receptor in specimens of ovarian cancer has recently been reported. Preliminary results have already suggested a possible influence of steroids on FMS (M-CSF receptor) expression. Fifty-five non-pretreated FIGO stage III/IV ovarian adenocarcinomas were studied for M-CSF transcripts and protein, as well as FMS transcripts and protein, using standard molecular biological techniques (Northern blot, slot blot analysis) and immunocytochemistry (ICC). Steroid receptor content was measured by DCC analysis in 44/55 specimens; in addition, ER/PR (oestrogen/progesterone) ICC was performed in 32/55 specimens. All tumours were shown to contain M-CSF-specific mRNA. Likewise, M-CSF protein was detected by ICC in the stroma and over the epithelium in all specimens. However, while most tumours were shown to contain FMS-specific mRNA, only 64 per cent of cases showed significant expression of FMS protein by tumour epithelium as shown by ICC. A statistically significant positive correlation was found between M-CSF and FMS mRNA expression levels. A week non-significant positive correlation was noted between FMS mRNA expression levels and tumour grade. Carcinomas were ER-positive in 66 per cent (DCC) or 34 per cent (ICC), and PR-positive in 73 per cent (DCC) or 34 per cent (ICC). A statistically significant positive correlation between ER (DCC) and M-CSF mRNA expression levels was found. Weak non-significant correlations were present between ER (ICC) and FMS (ICC), as well as between PR (DCC) and FMS mRNA expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗