Systemic administration of bevacizumab prolongs survival in an in vivo model of platinum pre-treated ovarian cancer.

Ovarian cancer patients often suffer from malignant ascites and pleural effusion. Apart from worsening the outcome, this condition frequently impairs the quality of life in patients who are already distressed by ovarian cancer. This study investigated whether single intraperitoneal administration of the anti-VEGF antibody bevacizumab is capable of reducing the ascites-related body surface and prolonging survival. The study was performed in an orthotopic murine model of peritoneal disseminated platin-resistant ovarian cancer. Mice were treated with bevacizumab and/or paclitaxel or buffer (control). Reduction of body surface and increased survival rates were assessed as therapeutic success. Survival of mice in all treatment groups was significantly enhanced when compared to the non-treatment control group. The combination of paclitaxel plus bevacizumab significantly improved body surface as well as overall survival in comparison to a treatment with only one of the drugs. Treatment of malignant effusion with a single dose of bevacizumab as an intraperitoneal application, with or without cytostatic co-medication, may be a powerful alternative to systemic treatment.

Combination of a MDR1-targeted replicative adenovirus and chemotherapy for the therapy of pretreated ovarian cancer.

PURPOSE: Targeted oncolytic adenoviruses capable of replication selectively in cancer cells are an appealing approach for the treatment of various cancer types refractory to conventional therapies. The aim of this study was to evaluate the effect of Ad5/3MDR1E1, a multidrug resistance gene 1 (MDR1)-targeted fiber-modified replication-competent adenovirus for the therapy of platinum-pretreated ovarian cancer in combination with cytostatic agents. METHODS: MDR1-specific tumor cell killing of Ad5/3MDR1E1 was systematically evaluated in chemotherapy naïve and pretreated ovarian cancer cells in vitro. Combinations of Ad5/3MDR1E1 and cytostatic agents were studied in vivo and in vitro. An in vivo hepatotoxicity model was used to evaluate liver toxicity. RESULTS: We demonstrate efficient oncolysis of Ad5/3MDR1E1 in chemotherapy-resistant ovarian cancer cells as well as therapeutic efficacy in an orthotopic mouse model. Further, combining Ad5/3MDR1E1 with paclitaxel resulted in greater therapeutic benefit than either agent alone. CONCLUSION: These preclinical data suggest that a fiber-modified adenovirus vector under the control of the MDR1 promoter represents a promising treatment strategy for platinum-pretreated ovarian cancer as a single agent or in combination with conventional anticancer drugs.

3D breast ultrasound: a significant predictor in breast cancer reduction under pre-operative chemotherapy.

BACKGROUND: The objective was the investigation of a possible predictive quantitative impact of initial tumor sphericity, measured by 3D sonography, on response to pre-operative chemotherapy. PATIENTS AND METHODS: This 3D ultrasound study was conducted on 41 consecutive primary breast cancer patients who received pre-operative epirubicin and paclitaxel chemotherapy; the tumors were measured by 3D sonography and by pathology after chemotherapy. Sphericity was defined as the ratio of the smallest to the largest extent by 3D sonography. RESULTS: A predictive impact of initial tumor sphericity on response to pre-operative chemotherapy was quantitatively identified for the first time. Sphericity was a significant predictor of pathological complete remission with a rank difference of 0.34 or about 1/3 i.e., spherical tumors were more likely to show successful remission. CONCLUSION: Tumor sphericity as defined from 3D sonography could be predictive of response to pre-operative chemotherapy regimens; prospective investigation is suggested.

Hysteroscopic management of residual trophoblastic tissue is superior to ultrasound-guided curettage.

STUDY OBJECTIVE: The aim of this study was to estimate the rate of intrauterine adhesions and subsequent pregnancy outcome in patients with residual trophoblastic tissue treated with hysteroscopic resection versus ultrasound-guided dilation and evacuation (D&E). DESIGN: Cohort study from 2 centers (Canadian Task Force classification II-2). SETTING: Two surgical teams at the University of Duesseldorf Medical Center and the PAN Clinic in Cologne, Germany. PATIENTS: Women with residual trophoblastic tissue after first- or second-trimester miscarriage or term delivery. INTERVENTION: Two techniques were used for the removal of residual trophoblastic tissue: ultrasound-guided evacuation with a curette (D&E) and hysteroscopic resection of trophoblastic tissue (HR). MEASUREMENTS AND MAIN RESULTS: We evaluated 95 patients who underwent secondary intervention for residual trophoblastic disease. A total of 42 patients underwent dilation of the cervix and ultrasound-guided curettage. In a second series of 53 patients, a resectoscope fitted with a 4-mm cutting loop was used for the removal of residual trophoblastic tissue used without application of current. Three months after the intervention, second-look office hysteroscopy was performed. Differences between both treatment groups were statistically significant. After HR, mild intrauterine adhesions were found in 2 patients (4.2%). After D&E, 12 patients (30.8%) presented with intrauterine adhesions (mild intrauterine adhesions: n = 7 [17.9%]; single dense adhesions: n = 3 [7.7%]; and extensive endometrial fibrosis n = 1 [2.6%]). Eighty-two patients wanted to become pregnant. Conception rate of all patients examined was 68.8% (HR) and 59.9% (D&E) (p < .05). In patients younger than 35 years of age who underwent HR, the pregnancy rate was significantly (p < .05) increased compared with patients who underwent D&E (78.1% vs 66.6%). In addition, patients from the HR group demonstrated a significantly (p < .05) shorter time to conception (11.5 month vs 14.5 month). CONCLUSION: The results of this study indicate that selective HR of residual trophoblastic tissue significantly reduces the incidence of intrauterine adhesions and increases pregnancy rates.

Treatment of chemotherapy resistant ovarian cancer with a MDR1 targeted oncolytic adenovirus.

OBJECTIVE: Multidrug resistance gene 1 (MDR1) mediated resistance to chemotherapeutic agents is a major obstacle for the therapy of various cancer types. The use of conditionally replicating adenoviruses (CRAds) is dependent on molecular differences between tumor cells and non tumor cells. Transcriptional targeting of CRAd replication is an effective way to control replication regulation. The aim of this study was to evaluate the effect of a MDR1 targeted fiber-modified CRAd against chemotherapy resistant ovarian cancer. METHODS: MDR1 expression was evaluated in chemotherapy naïve and pretreated ovarian cancer cells and various control cells. We constructed 2 variants of a fiber-modified CRAd, Ad5/3MDR1E1 and Ad5/3MDR1E1∆24 containing the MDR1 promoter to control viral replication via the E1A gene. The MDR promoter activity and cell killing efficacy were evaluated in vitro. Orthotopic murine models of peritoneally disseminated ovarian cancer were utilized to evaluate the preclinical efficacy of MDR targeted CRAds in vivo. To evaluate the liver toxicity of MDR1 targeted CRAds, we compared Ad5/3MDR1E1 with Ad5/3∆24, a CRAd that replicates in cancer cells inactive in the Rb/p16 pathway by use of an in vivo hepatotoxicity model. RESULTS: We demonstrate efficient oncolysis of Ad5/3MDR1E1 in both chemotherapy resistant ovarian cancer cell lines and in primary tumor cells from pretreated patients as well as therapeutic efficacy in an orthotopic mouse model. Ad5/3MDR1E1 demonstrated significantly decreased liver toxicity compared to other 5/3-fiber modified control vectors examined. CONCLUSIONS: In summary, Ad5/3MDR1E1 is an efficient and safe gene therapy approach for specific targeting of chemotherapy resistant cancer cells.

Modifications of laparoscopic supracervical hysterectomy technique significantly reduce postoperative spotting.

STUDY OBJECTIVE: The aim of this study was to estimate the benefit of excision of the endocervix during laparoscopic supracervical hysterectomy (LSH) with regard to postoperative cyclical bleeding. DESIGN: Cohort study from 2 centers (Canadian Task Force classification II-2). SETTING: Two surgical teams at the University of Duesseldorf Medical Center and PAN Clinic, Cologne, Germany. PATIENTS: Women with menstrual bleeding disorders resistant to medical treatment, symptomatic leiomyomata, dysmenorrhea. INTERVENTION: Laparoscopic supracervical hysterectomy. The uterus was transsected from the cervix with 2 techniques with and without excision of cervical canal. MEASUREMENTS AND MAIN RESULTS: We evaluated 300 patients who underwent consecutive LSH procedures. In 150 patients the uterus was transsected from the cervix using a monopolar loop. In a second series of 150 patients a unipolar needle electrode was used for the uterine amputation and the excision of cervical canal. The mean duration of the transsection was 65 seconds (monopolar loop) versus 168 seconds (monopolar needle). The excision of the endocervix was performed without any complications in 148 procedures. Histologic examination of the removed tissue revealed endocervical tissue in 83.3% (n = 125), endometrium in 9.4% (n = 14), cervicoisthmic mucosa in 3.3% (n = 5), and myometrium only in 4% (n = 4). All 300 patients were contacted 12 months after surgery to inquire about bleeding status, and 282 (94%) responded. In patients who underwent excision of the endocervix, postoperative cyclical bleeding was significantly reduced compared with the control group (1.4% vs 10.7%). CONCLUSION: The results of this study indicate that the routine excision of the endocervix is a quick safe procedure which allows a significant reduction of postoperative cyclical bleeding in patients who undergo LSH.

Treatment of endometriosis with a VEGF-targeted conditionally replicative adenovirus.

OBJECTIVE: To evaluate a vascular endothelial growth factor (VEGF)-targeted gene therapy for the treatment of endometriosis. DESIGN: Analysis of the VEGF gene expression and promoter activity in ectopic and eutopic endometrium. Evaluation of the specific replication and cell-killing effect of a VEGF-targeted adenovirus (Ad5VEGFE1) in endometriotic cells. PATIENT(S): Four patients who underwent hysterectomy for benign disease, 30 women with moderate superficial, and 30 women with deep infiltrating endometriosis. INTERVENTION(S): Immunostaining and gene expression of VEGF was examined in eutopic endometrium, endometriotic lesions, and normal peritoneum. The VEGF promoter activity was evaluated in eutopic endometrium and endometriotic lesions. A VEGF-targeted conditionally replicative adenovirus (Ad5VEGFE1) was evaluated regarding specific viral replication in endometriosis cells and induction of apoptosis. The biodistribution of the VEGF-targeted conditionally replicative adenovirus was examined in a mouse model. RESULT(S): The VEGF gene was highly expressed in ectopic endometrium compared with eutopic endometrium and normal peritoneum. The VEGF promoter was active in endometriotic cells. Ad5VEGFE1 showed efficient viral replication and induction of apoptosis in purified primary endometriotic cells and demonstrated a similar lower targeting to the liver and the uterus in a mouse model. CONCLUSION(S): Ad5VEGFE1 is a promising candidate for treating endometriosis and holds potential for clinical testing.

Hysteroscopy for asymptomatic postmenopausal women with sonographically thickened endometrium.

UNLABELLED: Endometrial carcinoma is the most common genital cancer in women. While patients usually present with vaginal bleeding, in 10-20% this characteristic symptom is absent. Endometrial thickness (double layer) is measured by transvaginal sonography and thickening indicates an increased risk of malignancy or other pathology (hyperplasia or polyps). OBJECTIVE: We sought to correlate hysteroscopic and pathological findings in asymptomatic postmenopausal women with sonographically thickened endometrium (>6mm). STUDY DESIGN: A prospective observational study in a university hospital of 304 postmenopausal women referred between 1996 and 2006 because of a sonographically thickened endometrium in the absence of abnormal bleeding, who underwent continuous flow hysteroscopy (4.5mm Storz hysteroscope) and fractionated curettage of the uterine cervix and corpus (D & C) in addition to vaginal sonography (5MHz probe). RESULTS: The mean age of the women was 64.8 (range 57.7-71.9) years. Average endometrial thickness measured by ultrasound was 12mm+/-6.7mm. Hysteroscopy suggested the presence of endometrial polyps in 226 women (74.3%), simple endometrial hyperplasia in 34 (11.2%), atrophic endometrium in 18 (5.9%), complex endometrial hyperplasia in 2 (0.7%), atypical hyperplasia in 3 (1%) and leiomyoma in 9 (3.0%). In 12 women (3.9%), the hysteroscopic appearance suggested malignancy and histology revealed endometrial adenocarcinoma. All hysteroscopic results were confirmed by histological examination. CONCLUSION: Hysteroscopy represents an easy, safe and effective method for the investigation of asymptomatic women with a thickened endometrium found with transvaginal ultrasound. The commonest pathology was endometrial polyps.

A fiber-modified mesothelin promoter-based conditionally replicating adenovirus for treatment of ovarian cancer.

PURPOSE: Recently, virotherapy has been proposed as a new therapeutic approach for ovarian cancer. Conditionally replicative adenoviruses (CRAd) may contain tumor-specific promoters that restrict virus replication to cancer cells. Mesothelin, a cell surface glycoprotein, is overexpressed in ovarian cancer but not in normal ovarian tissues. The purpose of this study was to explore the therapeutic utility of a mesothelin promoter-based CRAd in a murine model of ovarian cancer, using noninvasive in vivo imaging. EXPERIMENTAL DESIGN: We constructed a mesothelin promoter-based CRAd with a chimeric Ad5/3 fiber (AdMSLNCRAd5/3) that contains an Ad5 tail, Ad5 shaft, and an Ad3 knob. Previously, a chimeric Ad5/3 fiber has shown improved infectivity in many ovarian cancer cells. Viral replication and oncolysis were assessed in a panel of ovarian cancer cell lines. To test the oncolytic efficacy of AdMSLNCRAd5/3 in a murine model, bioluminescence imaging of tumor luciferase activity and survival analysis were done. RESULTS: AdMSLNCRAd5/3 achieved up to a 10,000-fold higher cell killing effect and up to 120-fold higher levels of viral replication in all human ovarian cancer cells, compared with wild-type Ad5. AdMSLNCRAd5/3 significantly inhibited tumor growth as confirmed by in vivo imaging (P < 0.05). Survival with AdMSLNCRAd5/3 was significantly enhanced when compared with no virus or with a wild-type Ad5-treated group (P < 0.05). CONCLUSIONS: The robust replication, oncolysis, and in vivo therapeutic efficacy of AdMSLNCRAd5/3 showed that this CRAd is a promising candidate for treating ovarian cancer. Importantly, we have applied in vivo imaging that has allowed repeated and longitudinal measurements of tumor growth after CRAd treatment.

Anticancer drugs induce mdr1 gene expression in recurrent ovarian cancer.

Ovarian cancer is currently the most lethal gynecologic malignancy in Europe and the US. Platin analogues and paclitaxel demonstrate high remission rates, but unfortunately the efficacy of cytostatic agents is limited by the development of multidrug resistance (mdr). Clinical paclitaxel resistance is often associated with mdr1 overexpression. In a recent study, we introduced a highly specific quantitative real-time reverse transcriptase polymerase chain reaction for the quantification of mdr1 transcripts. In the present study, we demonstrate that primary tumor cells from patients with recurrent ovarian cancer overexpress mdr1. To evaluate mdr1 expression, we collected tumor cells from 77 ovarian cancer patients (13 chemotherapy-naive ovarian cancer, 64 recurrent ovarian cancer). Cancer cells were aspirated from 49 solid specimens (63%) and 28 ascitic fluids (37%). Subsequently, cancer cells were exposed in 221 short-term cultures either to blank medium (control) or to a single anticancer drug, cisplatin, doxorubicin or paclitaxel. The drug concentrations applied referred to clinical relevant doses. mdr1 mRNA expression was significantly higher in specimens from recurrent ovarian cancer incubated in paclitaxel than in specimens from chemotherapy-naive ovarian cancer. No significant differences were detectable between the mean value of mdr1 mRNA expression in tumor specimens from recurrent ovarian cancer incubated in cisplatin or doxorubicin. Differences within the untreated patients group were also not statistically significant. The result of this study confirms clinical observations, as well as in-vitro studies based on tumor cell lines, that paclitaxel resistance is correlated with mdr1 overexpression.

A new targeting approach for breast cancer gene therapy using the heparanase promoter.

Gene therapy with adenoviral (Ad) vectors is a promising new approach in the treatment of cancer. Strategies to restrict adenoviral-mediated transgene expression are important to avoid gene transfer into normal cells. Heparanase (HPR) is overexpressed in breast cancer but downregulated in differentiated normal tissue. Expression of the HPR gene was evaluated in breast cancer cells. Biodistribution and liver tropism was evaluated in a mouse model. HPR is highly expressed in breast cancer tissue. The HPR promoter retained its fidelity in an adenovirus context and was activated in breast cancer cells but showed low activity in normal breast cells and the murine liver. We conclude that the HPR pathway is a promising target for the development of breast cancer directed gene therapy strategies.

A fiber-modified, secretory leukoprotease inhibitor promoter-based conditionally replicating adenovirus for treatment of ovarian cancer.

PURPOSE: The use of conditionally replicating adenoviruses (CRAD) is dependent on molecular differences between tumor cells and nontumor cells. Transcriptional targeting of CRAD replication via tumor-specific promoters is an effective way to control replication regulation. Genetic fiber pseudotyping is an approach for circumventing low expression of the primary adenovirus serotype 5 (Ad5) receptor by using the distinct adenovirus serotype 3 (Ad3) receptor for entry into and subsequent killing of ovarian cancer cells. EXPERIMENTAL DESIGN: In this study, we constructed a fiber-modified CRAD containing the secretory leukoprotease inhibitor (SLPI) promoter to control viral replication via the E1A gene (Ad5/3SLPI). To evaluate the liver toxicity of chimeric 5/3 fiber-modified CRADs, we compared Ad5/3SLPI with Ad5/3Cox-2L, a CRAD with E1A under control of the Cox-2 promoter, and Ad5/3Delta24, a CRAD that replicates in cancer cells inactive in the retinoblastoma/p16 pathway by use of an in vivo hepatotoxicity model and by a model system that uses slices of human liver. RESULTS: We show efficient viral replication and oncolysis of Ad5/3SLPI in both multiple ovarian cancer cell lines and primary tumor cell spheroids as well as therapeutic efficacy in an orthotopic mouse model of peritoneal carcinomatosis. Ad5/3SLPI showed significantly decreased liver toxicity compared with other 5/3 fiber-modified control vectors examined. CONCLUSIONS: In summary, Ad5/3SLPI is a promising vector candidate for treating metastatic ovarian cancer and showed robust virus replication, oncolysis, and in vivo therapeutic efficacy. Ad5/3SLPI showed comparatively low liver toxicity and therefore holds potential for patient use in the clinic.

A novel ex vivo model system for evaluation of conditionally replicative adenoviruses therapeutic efficacy and toxicity.

PURPOSE: Current animal tumor models are inadequate for the evaluation of toxicity and efficacy of conditionally replicative adenoviruses. A novel model system is needed that will provide insight into the anticipated therapeutic index of conditionally replicative adenoviruses preclinically. We endeavored to show a novel model system, which involves ex vivo evaluation of conditionally replicative adenovirus toxicity and therapeutic efficacy in thin, precision-cut slices of human primary tumor and liver. EXPERIMENTAL DESIGN: The Krumdieck thin-slice tissue culture system was used to obtain and culture slices of tumor xenografts of ovarian cancer cell lines, human primary ovarian tumors, and human liver. We determined the viability of slices in culture over a period of 36 to 48 hours by ([3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxphenyl-2-(4-sulfophenyl)-2H-tetrazolium, inner salt)]) (MTS) assay. In vitro Hey cells, slices of Hey xenografts, and human ovarian tumor or human liver slices were infected with 500vp/cell of either replication competent wild-type adenovirus (Ad5/3wt), conditionally replicative adenovirus (Ad5/3cox-2), or the replication deficient adenovirus (Ad5/3luc1). At 12-, 24-, and 36-hour intervals, the replication of adenoviruses in these slices was determined by quantitative reverse transcription-PCR of adenoviral E4 copy number. RESULTS: Primary tumor slices were able to maintain viability for up to 48 hours after infection with nonreplicative virus (Ad5luc1). Infection of Hey xenografts with Ad5/3cox-2 showed replication consistent with that seen in Hey cells infected in an in vitro setting. Primary tumor slices showed replication of both Ad5/3wt and Ad5/3cox over a 36-hour time period. Human liver slices showed replication of Ad5/3wt but a relative reduction in replication of Ad5/3cox-2 indicative of conditional replication "liver off" phenotype, thus predicting lower toxicity. CONCLUSIONS: The thin-slice model system represents a stringent method of ex vivo evaluation of novel replicative adenoviral vectors and allows assessment of human liver replication relative to human tumor replication. This is the first study to incorporate this system for evaluation of therapeutic efficacy and replicative specificity of conditionally replicative adenoviruses. Also, the study is the first to provide a valid means for preclinical assay of potential conditionally replicative adenovirus-based hepatotoxicities, thus providing a powerful tool to determine therapeutic index for clinical translation of conditionally replicative adenoviruses.

Evaluation of tissue-specific promoters in carcinomas of the cervix uteri.

BACKGROUND: Gene therapy is a novel approach for treatment of patients with advanced, recurrent, or metastatic cervical cancer. One effective way to direct transgene expression to specific tissues or tumors is the use of tissue-specific-promoters (TSPs). In the context of adenovirus (Ad)-mediated cancer gene therapy it is rational to choose a TSP which is highly expressed in the tumor but has potentially low activity in non-tumor cells, especially the liver. In this study, we have investigated several promoters which fulfill these criteria. Candidate cervical cancer specific TSPs include promoters of the genes for secretory leukoprotease inhibitor (SLPI), cyclooxygenase-2 (COX-2), Midkine (MK), vascular endothelial growth factor receptor type 1 (flt-1), vascular endothelial growth factor (VEGF), Survivin and the receptor for chemokine SDS-1 (CXCR4). METHODS: To evaluate the specific gene expression of the different promoters in the context of cervical cancer, we constructed a panel of E1-deleted Ads that express luciferase under the control of the promoters of interest. We investigated various established cervical cancer cell lines, as well as purified primary cancer cells and normal control cells from the cervix uteri. RESULTS: In all cell lines tested, promoters for MK, VEGF and CXCR4 showed the highest activity. Both MK and VEGF promoters also resulted in a high activity in primary cervical cancer cells. Interestingly, gene expression profiles correlate with luciferase activity in both cell lines and primary cancer samples. CONCLUSIONS: Our study demonstrates that the promoters for MK and VEGF are active in cervical cancer. We believe that both promoters can be successfully employed as TSPs for gene therapy targeted to cervical cancer.

Gene transfer to cervical cancer with fiber-modified adenoviruses.

Successful adenoviral (Ad) vector-mediated strategies for cancer gene therapy mandate gene-delivery systems that are capable of achieving efficient gene delivery in vivo. In many cancer types, in vivo gene-transfer efficiency remains limited due to the low or highly variable expression of the primary Ad receptor, the coxsackie Ad receptor (CAR). In this study, we evaluated the expression of CAR on cervical cancer cells as well as CAR-independent targeting strategies to integrins (Ad5.RGD), heparan sulfate proteoglycans (Ad5.pK7) or both (Ad5.RGD.pK7). We used a panel of established cervical cancer cell lines and primary cervical cancer cells isolated from patients to quantify the expression of CAR mRNA and to evaluate the gene-transfer efficiency of fiber-modified Ads. Of the fiber-modified vectors, Ad5.pK7 and Ad5.RGD.pK7 displayed significantly enhanced gene-transfer efficiency in vitro. Gene-delivery efficiency in vivo was evaluated using an s.c. cervical cancer mouse model. Ad5.RGD.pK7 significantly improves tumor targeting in vivo, resulting in a significantly improved tumor/liver ratio in mice. Our results suggest that the double-modified Ad5.RGD.pk7 vector enhances gene transfer to clinically relevant cervical cancer substrates, while the infectivity of nontarget cells in the mouse is not increased and comparable to Ad5. The fiber-modified virus described here can help achieve higher clinical efficacy of cervical cancer gene therapy.

Genetic replacement of the adenovirus shaft fiber reduces liver tropism in ovarian cancer gene therapy.

Approaches to alter the native tropism of adenoviruses (Ads) are beneficial to increase their efficacy and safety profile. Liver tropism is important with regard to potential clinical toxicity in humans. Ad5/3 chimeras in which the Ad5 knob is substituted by the Ad3 knob, such as Ad5/3luc1, have been recently shown to increase infectivity of ovarian cancer cell lines and primary tumor cells, which express low levels of the coxsackie-adenovirus receptor (CAR), without increasing infectivity of liver cells. A novel strategy to address the problem of liver uptake and improve the tumor/liver ratio is genetic replacement of the Ad fiber shaft. Ad5.Ad3.SH.luc1 is an Ad5-based vector that contains the fiber shaft from Ad serotype 3 but the fiber knob from Ad serotype 5. To compare tumor/liver of Ad5.Ad3.SH.luc1 and Ad5/3luc1 in vivo, we created three different tumor and treatment models of ovarian cancer in mice, simulating intraperitoneal and intravenous administration of tumors. Ad5.Ad3.SH.luc1 displayed the lowest liver tropism of all viruses in all models tested. Intravenous administration of all viruses resulted in higher tumor transduction rates compared to intraperitoneal administration. Genetic shortening of the Ad5 fiber shaft significantly increases relative tumor/liver gene transfer. This could improve the effective tumor dose and reduce side effects, thereby increasing the bioavailability of therapeutic agents.

Dysregulation of protein kinase C activity in chemoresistant metastatic breast cancer cells.

This study was performed to evaluate the role of protein kinase C (PKC) activity in the development of chemoresistance in clinical breast cancer cells. To simulate the clinical situation, native tumor cells derived from 10 patients with advanced breast cancer were brought into short-term cultures, and treated with anthracyclines (doxorubicin, mitoxantrone), paclitaxel and combinations, respectively. After 3 days of incubation, we determined total PKC activity relative to each control incubated with blank medium. Furthermore, we determined the chemoresistance against these drugs from each cell population separately. Relative PKC activity ranged from 14 to 249%; 64% (37 of 58) of the breast cancer cell suspensions were considered chemoresistant. There was a non-significant trend to a higher relative PKC activity in resistant cells compared to non-resistant cells (p=0.058), regardless of the antineoplastic agent investigated. The individual variability in both PKC activity and chemoresistance pattern revealed that dysregulated PKC activity mediates resistance to antineoplastics. In order to achieve clinical value, evaluation of more data concerning the PKC signal-transduction pathway is necessary. New protocols of cancer treatment will require this information in order to be successful.

Hematological side-effect profiles of individualized chemotherapy regimen for recurrent ovarian cancer.

The long-term results for patients with recurrent ovarian cancer (ROC) are poor. There is a need to optimize treatment strategies to improve outcome by avoiding ineffective regimens which are often associated with exacerbated side-effects. Individualized chemotherapy regimens guided by a chemosensitivity assay (ATP-tumor chemosensitivity assay) have already been used successfully to direct chemotherapy. Taking the results of this assay into account, application of drug combinations appears more advisable. Here we present a systematic evaluation of toxicities seen with individualized chemotherapy for ROC. A total of 62 patients who received 314 cycles of antineoplastic therapies were evaluated. Three single agents (topotecan, paclitaxel and gemcitabine) and five combinations (cisplatin/gemcitabine, carbopatin/gemcitabine, gemcitabine/treosulfan, mitoxantrone/paclitaxel and carboplatin/paclitaxel) were examined. With respect to myelotoxicity, most single agents except topotecan revealed favorable results in comparison to drug combinations. However, this observation lacks statistical significance. Generally, severe myelosuppression was rare. The highest incidence of leukopenia was seen in regimens with mitoxantrone/paclitaxel or gemcitabine/treosulfan, respectively. Thrombocytopenia accompanied most commonly a topotecan therapy. In the present study combination regimens tend to be more toxic than monotherapies. When response rates are comparable, empirically chosen treatment combination therapies should only be practiced in carefully planned clinical studies.

Cisplatin, doxorubicin and paclitaxel induce mdr1 gene transcription in ovarian cancer cell lines.

The clinical observation of the multidrug resistance (MDR) phenotype is often associated with overexpression of the mdrl gene, in particular with respect to ovarian cancer. However, until now the mdrl-inducing potential of commonly used antineoplastics has been only incompletely explored. We performed short-term cultures of six ovarian cancer cell lines (MZOV4, EF027, SKOV3, OAW42, OTN14, MZOV20) exposed to either blank medium or cisplatin, doxorubicin or paclitaxel at concentrations related to the clinically achievable plasma peak concentration. A highly specific quantitative real-time RT-PCR was used to detect the Mdr1 transcripts. Mdrl mRNA contents were calibrated in relation to coamplified GAPDH mRNA. Mdrl mRNA was detectable in each cell line. In 13 out of 18 assays (72%) the specific anticancer drug being tested induced mdr1 transcription. No decrease in mdr1 mRNA concentration was observed. Our data suggest that mdr1 induction by antineoplastics is one of the reasons for failure of ovarian cancer therapy but may vary individually.

A phase II study of dose-dense docetaxel and mitoxantrone in the treatment of patients with high-risk metastatic breast cancer.

Doxetaxel (DCT) and mitoxantrone (MX) are highly active and potentially synergistic agents in the treatment of metastatic breast cancer (MBC). This pilot study evaluates the combination of dose-dense DCT and MX in patients with MBC to determine the efficacy and toxicity of this therapy. Thirty-six patients (56.1+/-1.7 years) were studied. The patients received DCT (35 mg/m(2) q1w) and MX (6 mg/m(2) q2w) for 6 weeks of an 8-week interval. Patients with tumor response or stable disease (SD) continued the treatment for a maximum of two additional periods. Hematologic and non-hematologic parameters were determined using the WHO common toxicity score. During this study 14 patients (40%) experienced partial response, 14 (40%) SD. In 20% of the cases the disease progressed on therapy. The treatment with DCT and MX was well tolerated. Seventeen patients (47%) experienced grade 3 leukopenia. Other hematologic and non-hematologic side effects did not exceed grade 2. One patient died during therapy because of a pulmonary embolism, which was unlikely related to active agents. Dose-dense DCT and MX combines both clinical activity and convenience for the patient. Therefore, we conclude that this regimen is a promising therapy in MBC, which warrants confirmation by large-scale clinical trials.