molecular biology and human genetics program
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Publication
Journal: Journal of Clinical Endocrinology and Metabolism
January/29/1997
Abstract
In situ estrogen synthesis by hormone-dependent breast cancers could potentially regulate cellular proliferation through autocrine or paracrine mechanisms. Several biochemical studies have demonstrated activity of the enzyme aromatase, the rate-limiting step for estrogen synthesis, in breast tumor homogenates. Prior immunohistochemical studies in breast neoplasms demonstrated aromatase antibody binding to both stroma and parenchyma, but biochemically measured enzyme activity significantly correlated only with the level of staining in the stromal component. The present study sought to provide more direct evidence of the predominant role for stromal cell aromatase in breast tumor tissue. Accordingly, breast tumor stromal and epithelial cells were examined for aromatase enzyme activity and messenger ribonucleic acid (mRNA) expression. Stromal and epithelial cells from benign tissue served as a means of comparing activity and regulation in benign and tumor tissue. Enzyme activity in stromal cells from breast tumor tissue was low basally, but increased by 30- to 1200-fold when induced by dexamethasone. Combining dexamethasone with phorbol esters and cAMP produced an additional 1.2- to 4.1-fold stimulation. Analyses of exons III/V and exons IX/X demonstrated that aromatase mRNA expression was also substantially increased by these treatments. Increases in enzyme activity and mRNA expression in cells from benign breast stroma paralleled those observed in tumor stroma, although the increases in enzyme activity were generally lower. In contrast to the responses observed in stromal cells, epithelial cells from breast tumor or nonmalignant breast tissue were unresponsive to dexamethasone, either added alone or in combination with phorbol esters and cAMP. This study provides direct biochemical evidence that aromatase is present in stroma within breast tumors, as in surrounding tissues, and suggests that estrogen synthesis within the tumor may modulate tumor growth via a paracrine mechanism.
Publication
Journal: Annals of Epidemiology
September/1/2017
Abstract
Reproductive characteristics, the most established ovarian cancer risk factors, differ markedly between African-American and white women. Studies in predominantly white populations suggest that associations between reproductive characteristics and ovarian cancer vary by timing of the events and menopause status. This analysis examined associations between number, duration, and timing of reproductive events and epithelial ovarian cancer among African-American women.
Data from a multicenter case-control study of ovarian cancer in African-American women (641 cases/752 controls) were used to examine associations with oral contraceptive (OC) use and pregnancy characteristics. Odds ratios (ORs) and 95% confidence intervals (CIs) associated with reproductive characteristics were calculated with logistic regression models.
OC use (OR = 0.7, 95% CI 0.5-0.9), parity (OR = 0.5, 95% CI 0.3-0.6), and breastfeeding for >12 months (OR = 0.3, 95% CI 0.2-0.5) were inversely associated with ovarian cancer. More recent pregnancies and OC use had stronger associations with ovarian cancer than pregnancies or OC use that occurred earlier in life, especially among premenopausal women.
This study provides the first thorough documentation that pregnancy, breastfeeding, and OC use are inversely associated with ovarian cancer in African-American women, similar to what has been observed in white women. The associations with timing of the exposures suggest that these factors have both short- and long-term effects.
Publication
Journal: Journal of Oncology Practice
October/24/2017
Abstract
Financial toxicity negatively affects patients with cancer, especially racial/ethnic minorities. Patient-oncologist discussions about treatment-related costs may reduce financial toxicity by factoring costs into treatment decisions. This study investigated the frequency and nature of cost discussions during clinical interactions between African American patients and oncologists and examined whether cost discussions were affected by patient sociodemographic characteristics and social support, a known buffer to perceived financial stress. Methods Video recorded patient-oncologist clinical interactions (n = 103) from outpatient clinics of two urban cancer hospitals (including a National Cancer Institute-designated comprehensive cancer center) were analyzed. Coders studied the videos for the presence and duration of cost discussions and then determined the initiator, topic, oncologist response to the patient's concerns, and the patient's reaction to the oncologist's response.
Cost discussions occurred in 45% of clinical interactions. Patients initiated 63% of discussions; oncologists initiated 36%. The most frequent topics were concern about time off from work for treatment (initiated by patients) and insurance (initiated by oncologists). Younger patients and patients with more perceived social support satisfaction were more likely to discuss cost. Patient age interacted with amount of social support to affect frequency of cost discussions within interactions. Younger patients with more social support had more cost discussions; older patients with more social support had fewer cost discussions.
Cost discussions occurred in fewer than one half of the interactions and most commonly focused on the impact of the diagnosis on patients' opportunity costs rather than treatment costs. Implications for ASCO's Value Framework and design of interventions to improve cost discussions are discussed.
Publication
Journal: Nanotechnology
September/21/2017
Abstract
The triblock copolymer polyethylenimine-polycaprolactone-polyethylene glycol (PEI-PCL-PEG) has been shown to spontaneously assemble into nano-sized particulate carriers capable of complexing with nucleic acids for gene delivery. The objective of this study was to investigate micelleplex characteristics, their in vitro and in vivo fate following microfluidic preparation of siRNA nanoparticles compared to the routinely used batch reactor mixing technique. Herein, PEI-PCL-PEG nanoparticles were prepared with batch reactor or microfluidic mixing techniques and characterized by various biochemical assays and in cell culture. Microfluidic nanoparticles showed a reduction of overall particle size as well as a more uniform size distribution when compared to batch reactor pipette mixing. Confocal microscopy, flow cytometry and qRT-PCR displayed the subcellular delivery of the microfluidic formulation and confirmed the ability to achieve mRNA knockdown. Intratracheal instillation of microfluidic formulation resulted in a significantly more efficient (p < 0.05) knockdown of GAPDH compared to treatment with the batch reactor formulation. The use of microfluidic mixing techniques yields an overall smaller and more uniform PEG-PCL-PEI nanoparticle that is able to more efficiently deliver siRNA in vivo. This preparation method may prove to be useful when a scaled up production of well-defined polyplexes is required.
Publication
Journal: European Journal of Pharmacology
September/4/2017
Abstract
UTL-5g is a novel small-molecule TNF-alpha modulator. It reduces cisplatin-induced side effects by protecting kidney, liver, and platelets, thereby increasing tolerance for cisplatin. UTL-5g also reduces radiation-induced acute liver toxicity. The mechanism of action for UTL-5g is not clear at the present time. A phosphoproteomic analysis to a depth of 4943 phosphopeptides and a luminescence-based transcription factor activity assay were used to provide complementary analyses of signaling events that were disrupted by UTL-5g in RAW 264.7 cells. Transcriptional activity downstream of the interferon gamma, IL-6, type 1 Interferon, TGF-β, PKC/Ca2+ and the glucocorticoid receptor pathways were disrupted by UTL-5g. Phosphoproteomic analysis indicated that hyperphosphorylation of proteins involved in actin remodeling was suppressed by UTL-5g (gene set analysis, FDR < 1%) as was phosphorylation of Stat3, consistent with the IL-6 results in the transcription factor assay. Neither analysis indicated that LPS-induced activation of the NF-kB, cAMP/PKA and JNK signaling pathways were affected by UTL-5g. This global characterization of UTL-5g activity in a macrophage cell line discovered that it disrupts selected aspects of LPS signaling including Stat3 activation and actin remodeling providing new insight on how UTL-5g acts to reduce cisplatin-induced side effects.