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1.
Oncologist ; 28(9): 804-811, 2023 09 07.
Article in English | MEDLINE | ID: mdl-37335901

ABSTRACT

BACKGROUND: Real-world evidence is limited regarding the relationship between race and use of durvalumab, an immunotherapy approved for use in adults with unresectable stage III non-small cell lung cancer (NSCLC) post-chemoradiotherapy (CRT). This study aimed to evaluate if durvalumab treatment patterns differed by race in patients with unresectable stage III NSCLC in a Veterans Health Administration (VHA) population. MATERIALS AND METHODS: This was a retrospective analysis of White and Black adults with unresectable stage III NSCLC treated with durvalumab presenting to any VHA facility in the US from January 1, 2017, to June 30, 2020. Data captured included baseline characteristics and durvalumab treatment patterns, including treatment initiation delay (TID), interruption (TI), and discontinuation (TD); defined as CRT completion to durvalumab initiation greater than 42 days, greater than 28 days between durvalumab infusions, and more than 28 days from the last durvalumab dose with no new durvalumab restarts, respectively. The number of doses, duration of therapy, and adverse events were also collected. RESULTS: A total of 924 patients were included in this study (White = 726; Black = 198). Race was not a significant factor in a multivariate logistic regression model for TID (OR, 1.39; 95% CI, 0.81-2.37), TI (OR, 1.58; 95% CI, 0.90-2.76), or TD (OR, 0.84; 95% CI, 0.50-1.38). There were also no significant differences in median (interquartile range [IQR]) number of doses (White: 15 [7-24], Black: 18 [7-25]; P = .25) or median (IQR) duration of therapy (White: 8.7 months [2.9-11.8], Black: 9.8 months [3.6-12.0]; P = .08), although Black patients were less likely to experience an immune-related adverse event (28% vs. 36%, P = .03) and less likely to experience pneumonitis (7% vs. 14%, P < .01). CONCLUSION: Race was not found to be linked with TID, TI, or TD in this real-world study of patients with unresectable stage III NSCLC treated with durvalumab at the VHA.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Health Equity , Lung Neoplasms , Adult , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Retrospective Studies , Veterans Health , Chemoradiotherapy
2.
Future Oncol ; 19(28): 1905-1916, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37497677

ABSTRACT

Background: For eligible patients with unresectable stage III non-small-cell lung cancer, durvalumab consolidation therapy following chemoradiotherapy is the standard of care. Methods: This was a retrospective study of durvalumab-treated patients diagnosed between 1 August 2017 and 29 February 2020. Electronic health record data were assessed descriptively, with Kaplan-Meier methods used for duration of treatment and overall survival (OS). Results: Among 528 patients (median age 70Ā years, 51.5% male), the median duration of treatment was 7.1Ā months (95% CI: 6.0-9.0). Estimated 1- and 2-year OS rates were 83.5 and 64.0%, respectively, with median OS not reached. Conclusion: This study confirmed an OS benefit with durvalumab after chemoradiotherapy in a real-world setting, consistent with the results from the PACIFIC phase III clinical trial.


What is this article about? Durvalumab is a treatment approved for patients with a specific type of lung cancer. Clinical trials have shown durvalumab is an effective therapy for these patients. We conducted this study to better understand what happens to patients treated with durvalumab who were not enrolled in clinical trials. What were the results? Patients who were treated with durvalumab in this study tended to survive as long as patients who received it as part of a clinical trial. What do the results of the study mean? Studies like this one may better represent patients who are less likely to take part in clinical trials. Future studies may examine long-term outcomes of durvalumab and factors associated with better outcomes.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Male , Aged , Female , Carcinoma, Non-Small-Cell Lung/drug therapy , Retrospective Studies , Lung Neoplasms/drug therapy , Antibodies, Monoclonal/adverse effects , Chemoradiotherapy
3.
Curr Oncol ; 30(9): 8411-8423, 2023 Sep 13.
Article in English | MEDLINE | ID: mdl-37754526

ABSTRACT

BACKGROUND: Durvalumab is approved for the treatment of adults with unresectable stage III non-small cell lung cancer (NSCLC) post-chemoradiotherapy (CRT). This real-world study describes patient characteristics and durvalumab treatment patterns (number of doses and therapy duration; treatment initiation delays, interruptions, discontinuations, and associated reasons) among VHA-treated patients. METHODS: This was a retrospective cohort study of adults with unresectable stage III NSCLC receiving durvalumab at the VHA between 1 January 2017 and 30 June 2020. Patient characteristics and treatment patterns were presented descriptively. RESULTS: A total of 935 patients were included (median age: 69 years; 95% males; 21% Blacks; 46% current smokers; 16% ECOG performance scores ≥ 2; 50% squamous histology). Durvalumab initiation was delayed in 39% of patients (n = 367). Among the 200 patients with recorded reasons, delays were mainly due to physician preference (20%) and CRT toxicity (11%). Overall, patients received a median (interquartile range) of 16 (7-24) doses of durvalumab over 9.0 (2.9-11.8) months. Treatment interruptions were experienced by 19% of patients (n = 180), with toxicity (7.8%) and social reasons (2.6%) being the most cited reasons. Early discontinuation occurred in 59% of patients (n = 551), largely due to disease progression (24.2%) and toxicity (18.2%). CONCLUSIONS: These real-world analyses corroborate PACIFIC study results in terms of the main reasons for treatment discontinuation in a VHA population with worse prognostic factors, including older age, predominantly male sex, and poorer performance score. One of the main reasons for durvalumab initiation delays, treatment interruptions, or discontinuations was due to toxicities. Patients could benefit from improved strategies to prevent, identify, and manage CRT and durvalumab toxicities timely and effectively.

4.
Cancer ; 118(21): 5403-13, 2012 Nov 01.
Article in English | MEDLINE | ID: mdl-22570147

ABSTRACT

BACKGROUND: Efatutazone (CS-7017), a novel peroxisome proliferator-activated receptor gamma (PPARƎĀ³) agonist, exerts anticancer activity in preclinical models. The authors conducted a phase 1 study to determine the recommended phase 2 dose, safety, tolerability, and pharmacokinetics of efatutazone. METHODS: Patients with advanced solid malignancies and no curative therapeutic options were enrolled to receive a given dose of efatutazone, administered orally (PO) twice daily for 6 weeks, in a 3 + 3 intercohort dose-escalation trial. After the third patient, patients with diabetes mellitus were excluded. Efatutazone dosing continued until disease progression or unacceptable toxicity, with measurement of efatutazone pharmacokinetics and plasma adiponectin levels. RESULTS: Thirty-one patients received efatutazone at doses ranging from 0.10 to 1.15 mg PO twice daily. Dose escalation stopped when maximal impact on PPARƎĀ³-related biomarkers had been reached before any protocol-defined maximum-tolerated dose level. On the basis of a population pharmacokinetic/pharmacodynamic analysis, the recommended phase 2 dose was 0.5 mg PO twice daily. A majority of patients experienced peripheral edema (53.3%), often requiring diuretics. Three episodes of dose-limiting toxicities, related to fluid retention, were noted in the 0.10-, 0.25-, and 1.15-mg cohorts. Of 31 treated patients, 27 were evaluable for response. A sustained partial response (PR; 690 days on therapy) was observed in a patient with myxoid liposarcoma. Ten additional patients had stable disease (SD) for ≥60 days. Exposures were approximately dose proportional, and adiponectin levels increased after 4 weeks of treatment at all dose levels. Immunohistochemistry of archived specimens demonstrated that PPARƎĀ³ and retinoid X receptor expression levels were significantly greater in patients with SD for ≥60 days or PR (P = .0079), suggesting a predictive biomarker. CONCLUSIONS: Efatutazone demonstrates acceptable tolerability with evidence of disease control in patients with advanced malignancies.


Subject(s)
Antineoplastic Agents/administration & dosage , Neoplasms/drug therapy , PPAR gamma/agonists , Thiazolidinediones/administration & dosage , Administration, Oral , Adult , Aged , Antineoplastic Agents/adverse effects , Antineoplastic Agents/pharmacokinetics , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Humans , Male , Maximum Tolerated Dose , Middle Aged , Neoplasms/pathology , Thiazolidinediones/adverse effects , Thiazolidinediones/pharmacokinetics
5.
Patient Prefer Adherence ; 16: 123-135, 2022.
Article in English | MEDLINE | ID: mdl-35068928

ABSTRACT

PURPOSE: The approval of immune checkpoint inhibitors for metastatic non-small-cell lung carcinomas (mNSCLC) treatment has presented more care options. Therefore, it is important to identify the benefit-risk trade-offs patients and caregivers are willing to make among potential treatment options. This study quantified the preferences of patients and caregivers for attributes of mNSCLC treatment. METHODS: Patients with mNSCLC and caregivers completed an online survey assessing preferences using a discrete choice experiment. Respondents chose between hypothetical treatment profiles, with varying levels for 7 attributes associated with first-line treatment, including overall survival (OS), progression-free survival, select adverse events (AEs), and regimen (caregivers). Hierarchical Bayesian modeling was used to estimate attribute-level preference weights. RESULTS: Patients (n = 308) and caregivers (n = 166) most valued increasing OS from 11 to 30 months, followed by decreasing the risk of a serious AE (grade 3/4) that may lead to hospitalization from 70% to 18%. These attributes were over twice as important to both sets of respondents as the other attributes measured. Patients and caregivers would accept increases in the risks of a serious AE (grade 3/4) from 18% to 70% and all grades nausea from 10% to 69% if OS increased by 16.8 and 4.0 months, respectively. The least valued attributes were all grades of pneumonitis (patients) and all grades of skin rash (caregivers). CONCLUSION: Patients and caregivers are willing to make trade-offs between efficacy and toxicity and may require up to 1.5 years of increased OS to accept a higher risk of AEs. These results can provide guidance to oncologists when engaging in shared-decision making discussions.

6.
JAMA Oncol ; 7(12): 1824-1832, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34673888

ABSTRACT

IMPORTANCE: Updated estimates of non-small cell lung cancer (NSCLC) in the US are needed. OBJECTIVE: To calculate the most recent epidemiologic estimates of NSCLC in the US. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional epidemiological analysis used the most recently released data from US cancer registries. The population-based US Cancer Statistics (USCS) database (2010-2017), comprised of the Surveillance, Epidemiology, and End Results (SEER) program and the National Program of Cancer Registries (NPCR) (collectively, SEER-NPCR) provided the NSCLC incidence estimate. The SEER-18 database provided data for incidence, prevalence, survival, and initial treatment by NSCLC stage. Adults aged 18 years or older diagnosed with NSCLC identified by International Classification of Diseases for Oncology, Third Edition, morphology codes were included. MAIN OUTCOMES AND MEASURES: Annual age-adjusted NSCLC incidence per 100Ć¢Ā€ĀÆ000 persons; annual prevalence per 100Ć¢Ā€ĀÆ000 persons; survival rate; initial treatment. Due to database release delays, incidence data were available through 2017, and other parameters through 2016. The analysis was conducted from June 2020 to July 2020. RESULTS: There were 1.28 million new NSCLC cases recorded during 2010 to 2017 in the US (SEER-NPCR: 53% male; 67% ≥ 65 years). From 2010 to 2017, NSCLC incidence per 100Ć¢Ā€ĀÆ000 decreased from 46.4 to 40.9 overall (age <65 years: 15.5 to 13.5; age ≥65 years: 259.9 to 230.0); the incidence of stage II, IIIA, and IIIB NSCLC was stable, and stage IV decreased slightly from 21.7 to 19.6, whereas stage I incidence increased from 10.8 to 13.2. From 2010 to 2016, NSCLC prevalence per 100Ć¢Ā€ĀÆ000 increased from 175.3 to 198.3 (nationwide projection of SEER-18); prevalence increased among younger patients (77.5 to 87.9) but decreased among older patients (825.1 to 812.4). Period survival analysis found that 26.4% of patients survived 5 years, which is higher than previously reported. The proportion of stage I NSCLC treated with radiation as single initial treatment rose markedly from 14.7% in 2010 to 25.7% in 2016. Patients with stage IV NSCLC aged 65 years or older were most likely to be untreated (38.3%). CONCLUSIONS AND RELEVANCE: The findings of this cross-sectional epidemiological analysis suggest that the increased incidence of stage I NSCLC at diagnosis likely reflected improved evaluation of incidental nodules. A smaller proportion of patients aged 65 years or older with stage IV NSCLC were treated. Earlier detection and availability of effective treatments may underlie increased overall NSCLC prevalence, and higher than previously reported survival.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Adolescent , Adult , Aged , Carcinoma, Non-Small-Cell Lung/epidemiology , Carcinoma, Non-Small-Cell Lung/therapy , Cross-Sectional Studies , Female , Humans , Incidence , Lung Neoplasms/epidemiology , Lung Neoplasms/therapy , Male , Prevalence , SEER Program , United States/epidemiology
7.
JCO Oncol Pract ; 16(10): e1232-e1242, 2020 10.
Article in English | MEDLINE | ID: mdl-32552457

ABSTRACT

PURPOSE: We conducted a cross-sectional survey of practicing medical oncologists in the United States to obtain insight into physician and patient treatment decision making in stage III non-small-cell lung cancer (NSCLC). METHODS: A convenience sample of 150 oncologists completed a 38-question Web-based survey in January 2019. RESULTS: Surveyed oncologists (82% community based) had an average of 15 years of clinical experience and had treated an average of 20 patients newly diagnosed with stage III NSCLC in the previous 6 months. Oncologists reported presenting 55% of their patients with stage III NSCLC to tumor boards. For patients with new unresectable stage III NSCLC seen in the previous 6 months, concurrent chemoradiation therapy (cCRT) was reported as the initial treatment in an average of 48% of patients. The most frequent reason for delays in starting the initial chosen treatment was insurance preauthorization processes (reported by 65% of oncologists). A total of 55% of all patients with unresectable stage III NSCLC who received cCRT went on to receive consolidation immunotherapy; for patients who received consolidation chemotherapy after cCRT, the rate of immunotherapy was lower (42%). Biomarker test results were given as the reason for oncologists not recommending immunotherapy after cCRT in approximately a quarter of cases. The 112 oncologists with eligible patients who declined immunotherapy reported previous treatment fatigue as the reason in 34% of patients and insurance challenges in 19% of patients. CONCLUSION: Oncologists reported notable deviations from treatment guidelines for stage III NSCLC. Our findings highlight important opportunities to improve decision making and the coordination of care in stage III NSCLC.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Clinical Decision-Making , Lung Neoplasms , Oncologists , Practice Patterns, Physicians' , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/therapy , Chemoradiotherapy , Cross-Sectional Studies , Humans , Immunotherapy , Internet , Lung Neoplasms/therapy , Neoplasm Staging , Surveys and Questionnaires , United States
8.
BMC Cancer ; 8: 21, 2008 Jan 23.
Article in English | MEDLINE | ID: mdl-18215290

ABSTRACT

BACKGROUND: Genetically engineered mouse models of mammary gland cancer enable the in vivo study of molecular mechanisms and signaling during development and cancer pathophysiology. However, traditional whole mount and histological imaging modalities are only applicable to non-viable tissue. METHODS: We evaluated three techniques that can be quickly applied to living tissue for imaging normal and cancerous mammary gland: reflectance confocal microscopy, green fluorescent protein imaging, and ultrasound imaging. RESULTS: In the current study, reflectance confocal imaging offered the highest resolution and was used to optically section mammary ductal structures in the whole mammary gland. Glands remained viable in mammary gland whole organ culture when 1% acetic acid was used as a contrast agent. Our application of using green fluorescent protein expressing transgenic mice in our study allowed for whole mammary gland ductal structures imaging and enabled straightforward serial imaging of mammary gland ducts in whole organ culture to visualize the growth and differentiation process. Ultrasound imaging showed the lowest resolution. However, ultrasound was able to detect mammary preneoplastic lesions 0.2 mm in size and was used to follow cancer growth with serial imaging in living mice. CONCLUSION: In conclusion, each technique enabled serial imaging of living mammary tissue and visualization of growth and development, quickly and with minimal tissue preparation. The use of the higher resolution reflectance confocal and green fluorescent protein imaging techniques and lower resolution ultrasound were complementary.


Subject(s)
Green Fluorescent Proteins , Mammary Glands, Animal/anatomy & histology , Mammary Neoplasms, Experimental/diagnosis , Microscopy, Fluorescence/methods , Microscopy, Interference , Adenocarcinoma/diagnosis , Adenocarcinoma/diagnostic imaging , Animals , Female , Green Fluorescent Proteins/genetics , Mammary Glands, Animal/transplantation , Mammary Neoplasms, Experimental/diagnostic imaging , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microscopy, Confocal , Organ Culture Techniques , Transplantation, Homologous , Ultrasonography
9.
Cancer Chemother Pharmacol ; 71(3): 627-33, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23274395

ABSTRACT

BACKGROUND: Docetaxel is a taxane anticancer drug used in a wide variety of solid tumors. Liposomes are versatile drug carriers that may increase drug solubility, serve as sustained release systems, provide protection from drug degradation and toxicities, and help overcome multidrug resistance. This phase I study was conducted to determine the maximum tolerated dose, dose-limiting toxicities (DLTs), pharmacokinetics (PK), and clinical response of liposomal-encapsulated docetaxel (LE-DT) in patients with advanced solid tumor malignancies. METHODS: LE-DT was administered using a standard 3 + 3 dose escalation schema with dose levels of 50, 65, 85, 110, and 132 mg/m(2) IV on a 3-week cycle. Toxicities were assessed using the NCI-CTCAE version 3.0, and response was assessed using RECIST criteria (version 1.0). PK samples were drawn during cycle 1 and analyzed using a non-compartmental analysis. RESULTS: Twenty-four patients were treated for 1-30 cycles (median = 4). No DLTs were experienced through dose levels of 50, 65, 85, and 110 mg/m(2). Two out of two patients experienced grade 4 neutropenia at the 132 mg/m(2) dose level. When an additional three patients were treated at the expanded 110 mg/m(2) dose level, two experienced grade 4 neutropenia. The 85 mg/m(2) dose level was reassessed with an expanded group of three additional patients, and only one of three patients experienced grade 4 neutropenia. The protocol was amended to allow G-CSF during cycle 1, and an additional three patients were treated at 110 mg/m(2) with no DLTs experienced. No patient experienced significant neuropathy, even patients treated for 19, 20, and 30 cycles. PK followed a two-compartment elimination pattern; there was no correlation between PK and toxicity. Two patients with thyroid and neuroendocrine cancer had partial responses (PR, 8%), and one patient with non-small-cell lung cancer had an unconfirmed PR. Eight patients (33%) had stable disease lasting more than 3 months, for a clinical benefit rate of 41%. CONCLUSION: LE-DT was well tolerated with expected toxicities of neutropenia, anemia, and fatigue, but without neuropathy or edema. Clinical benefit (SD + PR) was observed in 41% of the patients. The recommended phase II dose of LE-DT is 85 mg/m(2) without G-CSF or 110 mg/m(2) with G-CSF.


Subject(s)
Antineoplastic Agents, Phytogenic/administration & dosage , Antineoplastic Agents, Phytogenic/therapeutic use , Neoplasms/drug therapy , Taxoids/administration & dosage , Taxoids/therapeutic use , Adult , Aged , Area Under Curve , Cohort Studies , Docetaxel , Drug Administration Schedule , Drug Carriers , Drug Compounding , Drug Resistance, Neoplasm , Excipients , Female , Freeze Drying , Half-Life , Humans , Infusions, Intravenous , Liposomes , Male , Maximum Tolerated Dose , Middle Aged , Treatment Outcome
10.
Cancer Chemother Pharmacol ; 70(6): 843-53, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23014737

ABSTRACT

PURPOSE: Pre-clinical data suggest that combining imatinib with traditional cytotoxic chemotherapy may improve imatinib efficacy. We conducted a Phase I study of imatinib in combination with paclitaxel in patients with advanced or metastatic solid tumors. METHODS: Patients were accrued to the study in a standard 3 + 3 design. Patients were restaged every two cycles, and those with stable disease (SD), or better, continued study treatment without interruption. Maximally tolerated doses (MTDs) and pharmacokinetic profiles of combination imatinib and paclitaxel were assessed. RESULTS: Fifty-eight patients were enrolled, including 40 in the Phase I dose escalation portion. Alternating dose escalation of imatinib and paclitaxel on a 28-day cycle resulted in MTDs of 800 mg imatinib daily, on days 1-4, 8-11, 15-18, and 22-25, and 100 mg/m(2) paclitaxel weekly, on days 3, 10, and 17. Two expansion cohorts, comprising 10 breast cancer patients and 8 patients with soft-tissue sarcomas, were enrolled at the MTDs. The most common adverse events were flu-like symptoms (64 %) and nausea/vomiting (71 %). The most common Grade 3/4 toxicities were neutropenia (26 %), flu-like symptoms (12 %), and pain (12 %). There were no relevant differences in the pharmacokinetic profiles of either drug when given in combination compared with alone. Thirty-eight subjects were evaluable for response, 18 (47.4 %) of whom experienced clinical benefit. Five patients (13.2 %) had a partial response (PR) and 13 patients (34.2 %) had SD; the average time to progression in those with clinical benefit was 17 weeks (range: 7-28 weeks). CONCLUSIONS: This combination of imatinib and paclitaxel was reasonably safe and tolerable, and demonstrated evidence of anti-tumor activity. Further exploration in disease-specific Phase II trials is warranted.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Neoplasms/drug therapy , Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/pharmacokinetics , Benzamides , Chemotherapy, Adjuvant , Cohort Studies , Disease Progression , Drug Administration Schedule , Drug Resistance, Neoplasm , Female , Humans , Imatinib Mesylate , Male , Maximum Tolerated Dose , Middle Aged , Neoplasms/radiotherapy , Neoplasms/surgery , Neutropenia/chemically induced , Paclitaxel/administration & dosage , Paclitaxel/adverse effects , Paclitaxel/pharmacokinetics , Piperazines/administration & dosage , Piperazines/adverse effects , Piperazines/pharmacokinetics , Pyrimidines/administration & dosage , Pyrimidines/adverse effects , Pyrimidines/pharmacokinetics , Radiotherapy, Adjuvant , Severity of Illness Index , Treatment Outcome
11.
Int J Cancer ; 108(5): 665-71, 2004 Feb 20.
Article in English | MEDLINE | ID: mdl-14696092

ABSTRACT

Signal transducers and activators of transcription (STATs) are latent cytoplasmic transcription factors that are activated and translocated into the nucleus after phosphorylation at a conserved tyrosine residue. Mouse model studies have demonstrated that activated Stat5a acts as a critical survival factor for normal, preneoplastic and malignant mammary epithelial cells. Very limited information is available, however, on the expression, tyrosine phosphorylation status and nuclear localization of Stat5a in human breast cancers. In our study, the pattern of Stat5a cellular localization was analyzed by immunohistochemistry in a series of 83 randomly selected primary human breast adenocarcinomas. Immunoprecipitation/Western blotting and immunohistochemistry assays employing different phospho-specific antibodies verified Stat5a tyrosine phosphorylation status. Stat5a was nuclear localized and tyrosine phosphorylated in 59 of 78 (76%) breast cancers examined; 38 of 78 (49%) demonstrated Stat5a nuclear localization in more than 25% of the breast cancer cells within the adenocarcinomas. Nuclear localized Stat5a was associated positively with increased levels of histologic differentiation (p = 0.03). A statistically significant positive association with p27 nuclear localization also was identified (p = 0.05). No relationship was found between nuclear localized Stat5a and menopausal status, tumor size, ploidy, percentage of cells in S-phase, lymph node metastases, ER, ErbB2, nuclear localized p21 or nuclear localized Stat5b/Stat3. As its role in human breast cancer progression and response to therapy is defined, Stat5a could become a new molecular target for breast cancer therapy.


Subject(s)
Adenocarcinoma/metabolism , Breast Neoplasms/metabolism , DNA-Binding Proteins/metabolism , Milk Proteins , Muscle Proteins , Trans-Activators/metabolism , Tyrosine/metabolism , Adult , Aged , Cell Differentiation , Cell Nucleus/metabolism , Female , Humans , Microfilament Proteins/metabolism , Phosphorylation , STAT3 Transcription Factor , STAT5 Transcription Factor , Tumor Suppressor Proteins
12.
Transgenic Res ; 11(4): 361-72, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12212839

ABSTRACT

Attempts to delineate the mechanisms of estrogen action have promoted the creation of several estrogen receptor alpha (ERalpha) mouse models in the past decade. These traditional models are limited by the fact that the receptors are either absent or present throughout all stages of development. The purpose of this work was to develop a conditional transgenic model that would provide an in vivo method of controlling the spatial and temporal regulation of ERalpha expression. The tetracycline responsive system was utilized. Three lines of transgenic mice carrying a transgene composed of the coding sequence for murine ERalpha placed under the regulatory control of a tet operator promoter (tet-op) were generated. These three lines of tet-op-mERa mice were each mated to an established line of transgenic mice expressing a tetracycline-dependent transactivator protein (tTA) from the mouse mammary tumor virus-long terminal repeat (MMTV-LTR). Double transgenic MMTV-tTA/tet-op-mERalpha mice were produced. All three lines demonstrated dominant gain of ERalpha shown by RT-PCR, immunoprecipitation, and immunohistochemistry. Transgene-specific ERalpha was expressed in numerous tissues including the mammary gland, salivary gland, testis, seminal vesicle, and epididymis. Expression was silenced by administration of doxycycline in the drinking water. This model can be utilized to evaluate the consequences of ERalpha dominant gain in targeted tissues at specific times during development. In this study dominant gain of ERalpha was associated with a reduction in epididymal/vas deferens and seminal vesicle weights consistent with the proposed action of ERalpha on fluid transport in the male reproductive tract. Combining this model with other dominant gain and gene knockout mouse models will be useful for testing effects of ERalpha action in combination with specific gene products and to evaluate if developmental and stage-specific expression of ERalpha can rescue identified phenotypes in gene knockout mice.


Subject(s)
Gene Expression Regulation/physiology , Mice, Transgenic , Receptors, Estrogen/genetics , Animals , Base Sequence , DNA Primers , DNA, Complementary/genetics , Estrogen Receptor alpha , Female , In Vitro Techniques , Mammary Tumor Virus, Mouse/genetics , Mice , Models, Animal , Organ Specificity , Polymerase Chain Reaction , Repetitive Sequences, Nucleic Acid
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