Bone marrow-derived mesenchymal stem cells as vehicles for interferon-beta delivery into tumors

Molecules that physiologically control cell proliferation are often produced locally in tissues and are rapidly destroyed when they enter circulation. This allows local effects while avoiding interference with other systems. Unfortunately, it also limits the therapeutic use of these molecules via systemic delivery. We here demonstrate that, for the purpose of anticancer therapy, bone marrow-derived mesenchymal stem cells (MSCs) can produce biological agents locally at tumor sites. We show that the tumor microenvironment preferentially promotes the engraftment of MSCs as compared with other tissues. MSCs with forced expression of IFN-beta inhibited the growth of malignant cells in vivo. Importantly, this effect required the integration of MSCs into the tumors and could not be achieved by systemically delivered IFN-beta or by IFN-beta produced by MSCs at a site distant from the tumors. Our results indicate that MSCs may serve as a platform for delivery of biological agents in tumors.     

Docetaxel and carboplatin as second-line chemotherapy for metastatic non-small cell lung cancer

The aim of this pilot study was to evaluate the activity and toxicity of docetaxel plus carboplatin as second-line treatment in patients with metastatic non-small cell lung cancer (NSCLC). Patients received docetaxel 75 mg/m(2) followed by carboplatin AUC 5 on day 1 every 3 weeks in an out-patient setting. Twenty-six patients were enrolled; 23 patients were diagnosed stage IV disease and three patients had a IIIB disease with malignant pleural effusion. The median interval from first to second-line treatment was 3.5 months (range 1-13). Patients received a total of 101 cycles with a median number of four cycles per patient (range 1-6). Five patients achieved a partial remission (19.23%; 95% confidence interval (CI) 6.55-39.35%), 11 had stable disease (42.31%) and ten progressed (38.46%) after initiation of second-line therapy. Median survival was 243 days (95% CI 182-336 days), the median progression-free survival was 118 days (95% CI 89-170 days), and the 1-year survival rate was 25.98% (95% CI 6.33-45.63%). Moderate haematological and mild nonhaematological toxicities were observed. No treatment-related death occurred. In conclusion, docetaxel plus carboplatin as second-line regimen has a reasonable activity with good tolerance and encouraging survival data.     

Experience with the Advanced Breast Biopsy Instrumentation (ABBI) system

BACKGROUND: The Advanced Breast Biopsy Instrumentation (ABBI) System is designed to excise nonpalpable breast lesions under stereotactic control. We report our experience with special regard to the histological evaluation of margins. PATIENTS AND METHODS: Breast biopsies using the ABBI system were performed on 101 patients with microcalcifications. In histologically-proven breast cancer, a re-excision was performed. RESULTS: Malignant lesions were found in thirteen patients (3 CLIS, 5 DCIS, 5 invasive ductal carcinoma). The margins were positive in two specimens with DCIS. In subsequent lumpectomies one patient with invasive cancer had residual intraductal cancer. All the patients with DCIS had residual cancer, even those with negative margins of the ABBI-specimen. Only minor complications were observed with the ABBI procedure. CONCLUSION: The ABBI system is a safe, minimally invasive stereotactic breast biopsy technique. It saves open biopsies in atypical hyperplasia and CLIS. In cases of DCIS or invasive cancer re-excision is inevitable.     

An in vivo mouse reporter gene (human secreted alkaline phosphatase) model to monitor ovarian tumor growth and response to therapeutics

PURPOSE: Developing new anticancer therapeutic regimens requires the measurement of tumor cell growth in response to treatment. This is often accomplished by injecting immunocompromised mice with cells from cancer tissue or cell lines. After treating the animals, tumor weight or volume is measured. Such methods are complicated by inaccuracies in measuring tumor mass and often animals must be killed to measure tumor burden. An in vivo tumor model system is presented in which the tumor cell line was stably transfected with a constitutively expressed marker gene: secreted human placental alkaline phosphatase protein (SEAP). The SEAP gene codes for a heat-stable protein that is produced at levels proportional to the amount of tumor cells in the animal. The SEAP protein is detectable in small blood samples so that animals can be repeatedly sampled over the trial period to monitor the course of tumor progression. METHODS: OCC1 ovarian carcinoma cells were stably transfected with pCMV-SEAP. The OCC1-SEAP cells were maintained in vitro to monitor the relationship between cell number and SEAP production. Experiments were performed in vivo to determine whether SEAP levels in blood corresponded to tumor burden. OCC1-SEAP cells were injected s.c. or intraperitoneally into nude mice and tumor volume was measured as well as plasma SEAP levels as the tumors developed. RESULTS: S.c. tumor volume correlated well with plasma SEAP levels ( R(2)=0.95). OCC1-SEAP cells were also injected intraperitoneally into nude mice and grown as abdominal tumors. After 3 weeks the animals were killed and the tumors were dissected and weighed. SEAP levels in plasma samples from the time of death correlated with intraperitoneal tumor weight ( R(2)=0.87). Experiments were performed to determine whether measuring SEAP levels could be used to monitor ovarian carcinoma cell response to platinum-containing chemotherapeutic drugs. OCC1-SEAP cells cultured in vitro were treated with the platinum-containing drug carboplatin. Carboplatin treatment decreased both cell proliferation and SEAP levels in culture medium. The constitutive rate of SEAP secretion per cell (nanograms SEAP per microgram DNA) was found not to be altered by carboplatin treatment. Therefore changes in SEAP level reflect changes in OCC1 tumor cell number, and not changes in regulation of SEAP secretion due to platinum containing chemotherapeutic drug treatment. OCC1 cells were injected intraperitoneally into nude mice and the mice were treated with the platinum-containing drugs cisplatin or carboplatin. Measurements of plasma SEAP over the treatment period showed OCC1-SEAP ovarian carcinoma growth to be inhibited by cisplatin and carboplatin treatment. CONCLUSION: The SEAP marker protein is constitutively expressed by tumor cells and blood levels are correlated with tumor cell number and burden. The results of these studies indicate that SEAP may be used as an in vivo reporter gene in a mouse model to monitor tumor growth and response to therapeutics. Future studies will utilize this model to investigate novel chemotherapeutic approaches to treating ovarian cancer.     

Comparisons of nomograms and urologists' predictions in prostate cancer

When applying nomograms to a clinical setting it is essential to know how their predictions compare with clinicians'. Comparisons exist outside of the prostate cancer literature. We reviewed these comparisons and conducted 2 experiments comparing predictions of clinicians with prostate cancer nomograms. By using Medline, we searched studies from January 1966 to July 1999 that compared human predictions with nomogram predictions. Next, we conducted 2 experiments: (1) 17 urologists were presented with 10 case vignettes and asked to predict the 5-year recurrence-free probabilities for each patient; (2) case presentations of 63 prostate cancer patients (including full clinical histories with complete diagnostic data and surgical findings) were made to a group of 25 clinicians who were asked to predict organ-confined disease. We found 22 published studies comparing human experts with nomograms, greater than half (13 of 22) showed the nomogram performing above the level of the human expert. Our first experiment showed urologist modification of 165 nomogram predictions led to a decrease in prediction accuracy (c-index decreased from.67 to.55, P <.05). In our second experiment, clinician predictions of organ-confined disease were comparable to the nomogram (area under the receiver operating characteristic curve [AUC] 0.78 and 0.79, respectively). A mixed-model suggests the nomogram did not augment clinician prediction accuracy (doctor excess error 1.4%, P =.75, 95% confidence interval [CI]: -10.9% to 8.2%). Our data suggest that nomograms do not seem to diminish predictive accuracy and they may be of significant benefit in certain clinical decision making settings.     

CT screening for lung cancer: the first ten years

This article reviews the current state of knowledge regarding computed tomography (CT) screening for lung cancer. The initial 3 studies have demonstrated the superiority of CT-based screening for lung cancer over traditional radiography. Furthermore, false-positive tests common on baseline screening were manageable without notable excess of biopsies or thoracotomies. Differences and similarities of various screening regimens are discussed in relation to reported study results. When comparing the various studies, the focus should be placed on the diagnostic distribution achieved under annual repeat screening, as it is this distribution which is obtained year after year of repeat screening and this distribution and the curability of these repeat screen-diagnosed lung cancer which determine the usefulness of the screening regimen. To date, these studies demonstrate a consistent shift to over 80% of the cancer being diagnosed in Stage IA. This marked shift suggest that the curability of screen-detected lung cancers will be markedly improved.     

Effects of cyclosporine on hematopoietic and immune functions in patients with hypoplastic myelodysplasia: in vitro and in vivo studies

BACKGROUND: Immunosuppression may benefit some patients with hypoplastic myelodysplasia (HMDS) and refractory anemia (RA), but its mechanism of action is still obscure. METHODS: Using flow cytometry, we studied Fas-receptor (Fas-R), Fas-ligand (Fas-L), and interferon-gamma (IFN-gamma) expression in CD34(+) cells and lymphocytes obtained from 11 HMDS and 20 RA patients. In colony assays and long-term cultures, the effects of Fas triggering, IFN-gamma blockade, or cyclosporine(CsA) on the growth of hematopoietic progenitors (colony-forming cells [CFC]) were determined. The effects of CsA at daily doses of 1-3 mg/kg for at least 3 months in HMDS patients were also studied. RESULTS: In basal conditions, committed and immature progenitor cells were found decreased in myelodysplastic (MDS) patients. No significant differences between HMDS and RA patients were detected. IFN-gamma-expressing CD4(+) cells were significantly increased in HMDS patients, whereas intracytoplasmic Fas-L expression was only borderline elevated in CD3(+) MDS cells. Increased numbers of CD34(+) cells expressing Fas-R were found in HMDS and RA patients. CFC and secondary CFC showed higher susceptibility to Fas-L-mediated inhibition and the blockade of IFN-gamma improved marrow primary, but not secondary, CFC growth. CsA added in vitro to patient's lymphocytes significantly decreased the number of IFN-gamma-expressing CD4(+) cells, but not Fas-L production. These effects were associated with increased colony formation. Similar to IFN-gammablockade, production of secondary CFC was not enhanced by CsA. Administration of CsA to patients resulted in prolonged partial hematologic improvement in 8 of 11 HMDS patients. CONCLUSIONS: Increased frequency of IFN-gamma producing CD4(+) cells supports the involvement of lymphocyte-mediated suppression of hematopoiesis in the development of cytopenia in MDS patients. The ability of CsA to decrease in vitro IFN-gamma production may improve hematopoietic function, explaining the beneficial effect of this agent in HMDS patients.     

p21, p27 and p53 in estrogen and antiprogestin-induced tumor regression of experimental mouse mammary ductal carcinomas

Metastatic mammary carcinoma tumor lines 59-2-HI and C7-2-HI originated in female BALB/c mice treated with medroxyprogesterone acetate and are maintained by syngeneic transplantation. Both lines express estrogen (ER) and progesterone receptors (PR) and regress completely after estradiol (E(2)) or antiprogestin treatment. The BET tumor line, of similar origin and biological features, regresses only after E(2) treatment. To investigate possible differences between E(2)- and antiprogestin-mediated effects we evaluated the morphological features, mitosis and apoptosis, and the differential expression of cell-cycle inhibitors associated with tumor regression. Treatments started when tumors reached 50-100 mm(2). After 24-96 h, tumors were excised and processed for morphological and immunohistochemical studies. Regression was associated with a significant and early decrease in the number of mitosis and with higher percentages of apoptotic cells. These phenomena were accompanied by an increase in p21 and p27 expression in the E(2) and antiprogestin-responsive lines treated with E(2), RU 38.486 or ZK 98.299 (P < 0.05). In BET tumors treated with E(2), p21 expression remained within basal levels and only p27 increased (P < 0.05). p53 was low in control 59-2-HI and C7-2-HI tumors and increased after treatment (P < 0.05) whereas BET untreated tumors already expressed high levels of p53 and MDM2. Although the immunohistochemical findings were compatible with alterations of p53, SSCP evaluation failed to disclose the presence of mutations, suggesting that the defective expression of p21 is related to an impaired p53 pathway. UV irradiation failed to increase p21 expression in BET, but was able to induce p53 and p21 in 59-2-HI and C7-2-HI tumors. The absence of an increased expression of p21 in E(2)-regressing BET lesions suggests that this protein is not necessary for estrogen-induced regression, but may be essential for antiprogestin action. Our results also suggest that p53/MDM2 alterations may be one of the mechanisms responsible for selected hormone resistance in breast carcinomas.