David Berz

Microvesicle entry into marrow cells mediates tissue-specific changes in mRNA by direct delivery of mRNA and induction of transcription

OBJECTIVEnMicrovesicles have been shown to mediate intercellular communication. Previously, we have correlated entry of murine lung-derived microvesicles into murine bone marrow cells with expression of pulmonary epithelial cell-specific messenger RNA (mRNA) in these marrow cells. The present studies establish that entry of lung-derived microvesicles into marrow cells is a prerequisite for marrow expression of pulmonary epithelial cell-derived mRNA.nnnMATERIALS AND METHODSnMurine bone marrow cells cocultured with rat lung, but separated from them using a cell-impermeable membrane (0.4-microm pore size), were analyzed using species-specific primers (for rat or mouse).nnnRESULTSnThese studies revealed that surfactant B and C mRNA produced by murine marrow cells were of both rat and mouse origin. Similar results were obtained using murine lung cocultured with rat bone marrow cells or when bone marrow cells were analyzed for the presence of species-specific albumin mRNA after coculture with rat or murine liver. These studies show that microvesicles both deliver mRNA to marrow cells and mediate marrow cell transcription of tissue-specific mRNA. The latter likely underlies the longer-term stable change in genetic phenotype that has been observed. We have also observed microRNA in lung-derived microvesicles, and studies with RNase-treated microvesicles indicate that microRNA negatively modulates pulmonary epithelial cell-specific mRNA levels in cocultured marrow cells. In addition, we have also observed tissue-specific expression of brain, heart, and liver mRNA in cocultured marrow cells, suggesting that microvesicle-mediated cellular phenotype change is a universal phenomena.nnnCONCLUSIONnThese studies suggest that cellular systems are more phenotypically labile than previously considered.

Marrow cell genetic phenotype change induced by human lung cancer cells.

Microvesicles have been shown to mediate varieties of intercellular communication. Work in murine species has shown that lung-derived microvesicles can deliver mRNA, transcription factors, and microRNA to marrow cells and alter their phenotype. The present studies evaluated the capacity of excised human lung cancer cells to change the genetic phenotype of human marrow cells. We present the first studies on microvesicle production by excised cancers from human lung and the capacity of these microvesicles to alter the genetic phenotype of normal human marrow cells. We studied 12 cancers involving the lung and assessed nine lung-specific mRNA species (aquaporin, surfactant families, and clara cell-specific protein) in marrow cells exposed to tissue in co-culture, cultured in conditioned media, or exposed to isolated lung cancer-derived microvesicles. We assessed two or seven days of co-culture and marrow which was unseparated, separated by ficoll density gradient centrifugation or ammonium chloride lysis. Under these varying conditions, each cancer derived from lung mediated marrow expression of between one and seven lung-specific genes. Microvesicles were identified in the pellet of ultracentrifuged conditioned media and shown to enter marrow cells and induce lung-specific mRNA expression in marrow. A lung melanoma and a sarcoma also induced lung-specific mRNA in marrow cells. These data indicate that lung cancer cells may alter the genetic phenotype of normal cells and suggest that such perturbations might play a role in tumor progression, tumor recurrence, or metastases. They also suggest that the tissue environment may alter cancer cell gene expression.

'Weighing in' on screening mammography.

Background Obesity is associated with increased post-menopausal breast cancer risk. Overweight and obese women also tend to have a poorer prognosis when diagnosed with breast cancer compared with their matched normal weight peers. In previous studies obesity was associated with decreased utilization of screening mammography. We present a study examining the association between Body Mass Index (BMI) and compliance with recommended mammographic screening using data from the 2004 Behavioral Risk Factor Surveillance Survey (BRFSS). Patients and methods We included 130,185 female participants, aged 40 and older, who were randomly selected to participate in the world largest telephone survey. After weighted analysis, this is representative of 56,226,220 non-institutionalized US women. The primary outcome was the proportion of women who underwent screening mammography within the last 2xa0years preceding the survey stratified by BMI. The mammography screening behavior of normal weight women (BMI 18.5–24.99) was compared with underweight (<18.5), overweight (25–29.99), and women with obesity class I (30–34.99), class II (35–39.99), and class III (≥40) using logistic regression analysis and weighted to provide estimates of women in the United States (US). Results Our sample included 1.91% underweight, 37.91% normal weight, 30.15% overweight and 14.36%, 5.44%, and 3.49% women with obesity classes’ I–III respectively. Approximately 7% of women age 40 and older had insufficient information to calculate their BMI. Adjusting for age, race, smoking status, general health perception, level of education, and income level, underweight women had lower odds of complying with regular screening mammography (OR 0.57; 95% CI, 0.48–0.68). Women with obesity class III (OR 0.97; 95% CI, 0.84–1.13) showed a trend towards underutilization of screening mammograms which was not clinically significant. In contrary, in overweight women a significantly higher association with appropriate mammography utilization was identified OR 1.08 (95% CI, 1.01–1.15). Although not statistically significant, women with class I and II obesity showed a trend towards a higher utilization 1.08 (95% CI, 0.99–1.18) and 1.10 (95% CI, 0.98–1.25) respectively, when compared to women at desired weight. Conclusion We present a weighted analysis of the BRFSS, evaluating the association of BMI and appropriate screening mammography among women 40xa0years and older. These results are generalizable to the US population of women in this age range. Underweight women had significantly lower odds of utilizing screening mammography appropriately when compared with women at desired weight. Results from previous studies reporting underutilization of screening mammography in high risk, obese, and overweighed women were not confirmed in this largest population based analysis performed to date.

A Phase I Study of Dasatinib with Concurrent Chemoradiation for Stage III Non-Small Cell Lung Cancer

Objectives: Src family kinases (SFKs) are expressed in non-small cell lung cancer (NSCLC) and may be involved in tumor growth and metastases. Inhibition of SFK may also enhance radiation. The purpose of this study was to evaluate if a maximum dose of 100u2009mg of dasatinib could be safely administered with concurrent chemoradiation and then continued as maintenance for patients with newly diagnosed stage III NSCLC. Methods: Patients with stage III locally advanced NSCLC received paclitaxel, 50u2009mg/m2/week, with carboplatin area under the curve (AUC)u2009=u20092, weekly for 7u2009weeks, and concurrent radiotherapy, 64.8u2009Gy. Three dose levels of dasatinib 50, 70, and 100u2009mg/day were planned. Results: 11 patients with locally advanced NSCLC were entered. At the 70u2009mg dose level 1 patient had grade 5 pneumonitis not responsive to therapy, and one patient had reversible grade 3 pneumonitis and grade 3 pericardial effusion. Due to these toxicities the Brown University Oncology Group Data Safety Monitoring Board terminated the study. Conclusion: Dasatinib could not be safely combined with concurrent chemoradiation for stage 3 lung cancer due to pneumonitis.

Pneumonectomy After Neoadjuvant Chemotherapy and Radiation for Advanced-Stage Lung Cancer

BackgroundIntergroup 0139 Trial suggests an increase in mortality after pneumonectomy in patients receiving preoperative chemotherapy and radiation. We evaluate our outcomes with pneumonectomy after neoadjuvant chemotherapy and radiation.MethodsNeoadjuvant chemotherapy and radiation consisted of cisplatin 50xa0mg/m2 on days 1, 8, 29, and 36 and etoposide 50xa0mg/m2 on days 1–5 and 29–33 given concurrently with 5,040xa0cGy radiation. From a prospective database, results after pneumonectomy were compared between patients receiving and not receiving neoadjuvant chemotherapy and radiation during the same time period.ResultsOver 7xa0years, 50 pneumonectomies were performed for non-small-cell carcinoma; 18 received neoadjuvant chemotherapy and radiation (group A) and 32 did not (group B). Comparing group A with group B, there was no significant difference in patient demographics, blood loss, transfusion requirements or pneumonectomy side. Group A had more patients with stage III disease [17/18 (94%) versus 15/32 (47%), Pxa0=xa00.001] and also more often had vascularized flap for bronchial stump coverage [17/18 (94%) versus 4/32 (13%), Pxa0<xa00.001]. There was no significant difference in operative morbidity or mortality. Mortality for group A was 0/18 and for group B was 2/32 (6.3%) (Pxa0=xa00.530). Group A patients with IIIA(N2) disease (nxa0=xa013) had median recurrence-free survival of 12.4xa0months, median overall survival of 25xa0months, and 3-year overall survival of 22.2%.ConclusionsUsing a multidisciplinary team approach at a tertiary care center, pneumonectomy can be performed successfully after neoadjuvant chemotherapy and radiation for advanced-stage lung cancer. Vascularized flap for bronchial stump coverage may be important in this regard.

HER family inhibitors in pancreatic cancer: current status and future directions

Pancreatic cancer is characterized by multiple genetic abnormalities that can be used as targets for specific therapeutics. The HER family consists of four transmembrane growth factor receptors. Targeting HER1 with the epidermal growth factor receptor tyrosine kinase inhibitor erlotinib demonstrated a survival advantage for patients with advanced pancreatic cancer. Multiple other agents that target members of the HER family are under investigation. These include reversible and irreversible, single and pan HER tyrosine kinase inhibitors. Chimeric, humanized and fully human monoclonal antibodies that target specific HER receptors are also being studied. These agents are also radiation sensitizers. This article reviews clinical trials of HER family inhibitors in pancreatic cancer, discusses the role of these agents in the management of patients and outlines future directions for pancreatic cancer management.

Targeting Signaling Pathways in Cancer Therapy

The clinical results of treatment with traditional chemotherapy for most solid tumor malignancies have remained disappointing over the last decades. Toxicities are often prohibitive. This demands the development of innovational, systemic treatment approaches. Small-molecule tyrosine kinase inhibitors (sm-TKIs) have shown promising results in several malignancies. We are reviewing the current progress of cancer therapy with sm-TKIs in solid tumor malignancies with a focus on breast cancer, hepatocellular cancer, colon cancer, and nonsmall-cell lung cancer and place this progress into the context of improvements in recent, targeted antineoplastic therapies.