Bartonella- and Borrelia-Related Disease Presenting as a Neurological Condition Revealing the Need for Better Diagnostics

The diagnostic tests available to identify vector-borne pathogens have major limitations. Clinicians must consider an assortment of often diverse symptoms to decide what pathogen or pathogens to suspect and test for. Even then, there are limitations to the currently available indirect detection methods, such as serology, or direct detection methods such as molecular tests with or without culture enrichment. Bartonella spp., which are considered stealth pathogens, are particularly difficult to detect and diagnose. We present a case report of a patient who experienced a spider bite followed by myalgia, lymphadenopathy, and trouble sleeping. She did not test positive for Bartonella spp. through clinically available testing. Her symptoms progressed and she was told she needed a double hip replacement. Prior to the surgery, her blood was submitted for novel molecular testing, where Bartonella spp. was confirmed, and a spirochete was also detected. Additional testing using novel methods over a period of five years found Bartonella henselae and Borrelia burgdorferi in her blood. This patient's case is an example of why new diagnostic methods for vector-borne pathogens are urgently needed and why new knowledge of the variable manifestations of Bartonellosis need to be provided to the medical community to inform and heighten their index of suspicion.

Bartonella henselae Detected in Malignant Melanoma, a Preliminary Study

Bartonella bacilliformis (B. bacilliformis), Bartonella henselae (B. henselae), and Bartonella quintana (B. quintana) are bacteria known to cause verruga peruana or bacillary angiomatosis, vascular endothelial growth factor (VEGF)-dependent cutaneous lesions in humans. Given the bacteria's association with the dermal niche and clinical suspicion of occult infection by a dermatologist, we determined if patients with melanoma had evidence of Bartonella spp. infection. Within a one-month period, eight patients previously diagnosed with melanoma volunteered to be tested for evidence of Bartonella spp. exposure/infection. Subsequently, confocal immunohistochemistry and PCR for Bartonella spp. were used to study melanoma tissues from two patients. Blood from seven of the eight patients was either seroreactive, PCR positive, or positive by both modalities for Bartonella spp. exposure. Subsequently, Bartonella organisms that co-localized with VEGFC immunoreactivity were visualized using multi-immunostaining confocal microscopy of thick skin sections from two patients. Using a co-culture model, B. henselae was observed to enter melanoma cell cytoplasm and resulted in increased vascular endothelial growth factor C (VEGFC) and interleukin 8 (IL-8) production. Findings from this small number of patients support the need for future investigations to determine the extent to which Bartonella spp. are a component of the melanoma pathobiome.

Interactions between the complement and endothelin systems in normal pregnancy and following placental ischemia

Preeclampsia is characterized by new onset hypertension and fetal growth restriction and is associated with aberrant activation of the innate immune complement system and stressed or ischemic placenta. Previous studies have suggested a role for both endothelin and complement system activation products in new onset hypertension in pregnancy, but inter-relationships of the pathways are unclear. We hypothesized that complement activation following placental ischemia stimulates the endothelin pathway to cause hypertension and impair fetal growth. The Reduced Uterine Perfusion Pressure (RUPP) model results in hypertension and fetal growth restriction in a pregnant rat due to placental ischemia caused by mechanical obstruction of blood flow to uterus and placenta. The effect of inhibitor of complement activation soluble Complement Receptor 1 (sCR1) and endothelin A receptor (ET_A) antagonist atrasentan on hypertension, fetal weight, complement activation (systemic circulating C3a and local C3 placental deposition) and endothelin [circulating endothelin and message for preproendothelin (PPE), ET_A and endothelin B receptor (ET_B) in placenta] in the RUPP rat model were determined. Following placental ischemia, sCR1 attenuated hypertension but increased message for PPE and ET_A in placenta, suggesting complement activation causes hypertension via an endothelin independent pathway. With ET_A antagonism the placental ischemia-induced increase in circulating C3a was unaffected despite inhibition of hypertension, indicating systemic C3a alone is not sufficient. In normal pregnancy, inhibiting complement activation increased plasma endothelin but not placental PPE message. Atrasentan treatment increased fetal weight, circulating endothelin and placental ET_A message, and unexpectedly increased local complement activation in placenta (C3 deposition) but not C3a in circulation, suggesting endothelin controls local placental complement activation in normal pregnancy. Atrasentan also significantly decreased message for endogenous complement regulators Crry and CD55 in placenta and kidney in normal pregnancy. Results of our study indicate that complement/endothelin interactions differ in pregnancies complicated with placental ischemia vs normal pregnancy, as well as locally vs systemically. These data clearly illustrate the complex interplay between complement and endothelin indicating that perturbations of either pathway may affect pregnancy outcomes.

A tRNA fragment, tRF5-Glu, regulates BCAR3 expression and proliferation in ovarian cancer cells

Ovarian cancer is a complex disease marked by tumor heterogeneity, which contributes to difficulties in diagnosis and treatment. New molecular targets and better molecular profiles defining subsets of patients are needed. tRNA fragments (tRFs) offer a recently identified group of noncoding RNAs that are often as abundant as microRNAs in cancer cells. Initially their presence in deep sequencing data sets was attributed to the breakdown of mature tRNAs, however, it is now clear that they are actively generated and function in multiple regulatory events. One such tRF, a 5’ fragment of tRNA-Glu-CTC (tRF5-Glu), is processed from the mature tRNA-Glu and is shown in this study to be expressed in ovarian cancer cells. We confirmed that tRF5-Glu binds directly to a site in the 3’UTR of the Breast Cancer Anti-Estrogen Resistance 3 (BCAR3) mRNA thereby down regulating its expression. BCAR3 has not previously been studied in ovarian cancer cells and our studies demonstrate that inhibiting BCAR3 expression suppresses ovarian cancer cell proliferation. Furthermore, mimics of tRF5-Glu were found to inhibit proliferation of ovarian cancer cells. In summary, BCAR3 and tRF5-Glu contribute to the complex tumor heterogeneity of ovarian cancer cells and may provide new targets for therapeutic intervention.

HSP90 inhibitors in the context of heat shock and the unfolded protein response: effects on a primary canine pulmonary adenocarcinoma cell line

BACKGROUND

Agents targeting HSP90 and GRP94 are seldom tested in stressed contexts such as heat shock (HS) or the unfolded protein response (UPR). Tumor stress often activates HSPs and the UPR as pro-survival mechanisms. This begs the question of stress effects on chemotherapeutic efficacy, particularly with drugs targeting chaperones such as HSP90 or GRP94. We tested the utility of several HSP90 inhibitors, including PU-H71 (targeting GRP94), on a primary canine lung cancer line under HS/UPR stress compared to control conditions.

METHODS

We cultured canine bronchoalveolar adenocarcinoma cells that showed high endogenous HSP90 and GRP94 expression; these levels substantially increased upon HS or UPR induction. We treated cells with HSP90 inhibitors 17-DMAG, 17-AAG or PU-H71 under standard conditions, HS or UPR. Cell viability/survival was assayed. Antibody arrays measured intracellular signalling and apoptosis profiles.

RESULTS

HS and UPR had varying effects on cells treated with different HSP90 inhibitors; in particular, HS and UPR promoted resistance to inhibitors in short-term assays, but combinations of UPR stress and PU-H571 showed potent cytotoxic activity in longer-term assays. Array data indicated altered signalling pathways, with apoptotic and pro-survival implications. UPR induction + dual targeting of HSP90 and GRP94 swayed the balance toward apoptosis.

CONCLUSION

Cellular stresses, endemic to tumors, or interventionally inducible, can deflect or enhance chemo-efficacy, particularly with chaperone-targeting drugs. Stress is likely not held accountable when testing new pharmacologics or assessing currently-used drugs. A better understanding of stress impacts on drug activities should be critical in improving therapeutic targeting and in discerning mechanisms of drug resistance.

Role of IgM and angiotensin II Type I receptor autoantibodies in local complement activation in placental ischemia-induced hypertension in the rat

Preeclampsia is characterized by development of hypertension during pregnancy and reduced placental perfusion. Previous studies in a rat model of placental ischemia-induced hypertension demonstrated that inhibiting complement activation attenuated increased maternal blood pressure with C3a and C5a identified as the important products of complement activation. Given that in other forms of ischemia both natural IgM and antigen antibody complexes initiate complement activation, we hypothesized that placental ischemia exposes neoepitopes recognized by IgM to cause local complement activation and hypertension. Alternatively, we postulated that autoantibody to angiotensin II Type 1 receptor (AT1-AA) interacts with AT1 receptors to cause complement activation. Since complement activation occurs in kidney and placenta in preeclampsia, we used immunohistochemistry to determine IgM deposition and local complement activation in each organ (C3 deposition), and quantitative real-time polymerase chain reaction (qRT-PCR) to quantitate mRNA for endogenous regulators of complement activation CD55, CD59 and Complement receptor 1-related gene/protein y (Crry). On gestation day (GD)14.5, timed pregnant Sprague Dawley rats underwent Sham surgery or placement of clips on inferior abdominal aorta and ovarian arteries to create placental ischemia using the reduced utero-placental perfusion pressure (RUPP) model. As previously reported, RUPP surgery increased mean arterial pressure and circulating C3a on GD19.5. In placenta, IgM and C3 deposition increased, whereas mRNA for complement regulators Crry and CD59 decreased along with Crry protein in RUPP compared to Sham treated animals. In kidney, IgM deposition increased in animals subjected to RUPP vs Sham surgery without a significant change in C3 deposition and coincident with an increase in mRNA for CD55 and CD59. The AT1 receptor antagonist losartan prevents placental ischemia-induced hypertension as well as AT1-AA interaction with AT1 receptors. However, losartan did not attenuate complement activation as measured by circulating C3a or placental C3 deposition. Importantly, our studies indicate that following placental ischemia, complement activation is not due to AT1-AA but is associated with IgM deposition. These studies suggest a role for natural antibodies interacting with placental ischemia-induced neoepitopes to activate complement and contribute to hypertension.

A method to distinguish morphologically similar Peromyscus species using extracellular RNA and high-resolution melt analysis

A method applying high-resolution melt (HRM) analysis to PCR products copied and amplified from extracellular RNA (exRNA) has been developed to distinguish two morphologically similar Peromyscus species: Peromyscus leucopus and Peromyscus maniculatus. P. leucopus is considered the primary reservoir host of Borrelia burgdorferi, the causative agent for Lyme disease in North America. In northern Minnesota the habitat ranges of P. leucopus overlaps with that of P. maniculatus. Serum samples from live mice of both species were collected from cheek bleeds, total extracellular RNA (exRNA) was extracted, copied using reverse transcription and amplified by PCR followed by HRM analysis. A circulating ribosomal RNA (rRNA) was identified which differed at seven nucleotides between the two species and a method of HRM analysis was developed allowing rapid species confirmation. In the future, this HRM based method may be adapted for additional species.

Beyond the Ribosome: Extra-translational Functions of tRNA Fragments

High-throughput sequencing studies of small RNAs reveal a complex milieu of noncoding RNAs in biological samples. Early data analysis was often limited to microRNAs due to their regulatory nature and potential as biomarkers; however, many more classes of noncoding RNAs are now being recognized. A class of fragments initially excluded from analysis were those derived from transfer RNAs (tRNAs) because they were thought to be degradation products. More recently, critical cellular function has been attributed to tRNA fragments (tRFs), and their conservation across all domains of life has propelled them into an emerging area of scientific study. The biogenesis of tRFs is currently being elucidated, and initial studies show that a diverse array of tRFs are generated from all parts of a tRNA molecule. The goal of this review was to present what is currently known about tRFs and their potential as biomarkers for the earlier detection of disease.

Identification of heat shock protein 10 within the equine embryo, endometrium, and maternal peripheral blood mononuclear cells

Early pregnancy factor has been identified as a 10-kDa extracellular homolog of heat shock protein 10 (Hsp10). Hsp10 has been detected during early pregnancy in serum of mice, sheep, pigs, horses, cows, and humans by the rosette inhibition test. Hsp10 has also been associated with several neoplastic and autoimmune diseases. The goal of the present study was to determine if Hsp10 could be detected in the early equine embryo through the use of immunohistochemistry and quantitative real-time PCR. Additionally, analysis of systemically harvested peripheral blood mononuclear cells (PBMCs) from both pregnant and nonpregnant mares was evaluated to determine expression levels of HSP10. Embryos were collected from Quarter Horse mares by uterine lavage at either 8 or 25 days after ovulation. Collection and separation of PBMCs occurred on Day 8 for both pregnant and nonpregnant mares. Immunohistochemistry revealed cytoplasmic localization of HSP10 throughout the single layer of ectodermal cells forming the trophoblast in Day-8 embryos. Day-25 embryos demonstrated intense localization focally along the apical border of ectodermal cells forming the trophoblast layer of the developing chorion. There was no nuclear staining in either embryonic population. Quantitative real-time PCR detected the presence of mRNA for HSP10 in both 8- and 25-day equine embryos. Day-25 embryos exhibited an elevated degree of expression (P = 0.006) compared with the 8-day embryos for HSP10. Endometrial samples did not display any significant difference in degree of expression for HSP10 (P = 0.10). Finally, PBMCs from pregnant mares demonstrated elevated (P = 0.03) expression of HSP10 compared to the nonpregnant mares on Day 8 of the estrous cycle. This study confirmed the presence of HSP10 protein and mRNA expression of HSP10 in equine embryos at two maturation stages. Additionally, the presence of increased gene expression within PBMCs of pregnant mares suggests communication, possibly leading to necessary immunomodulatory effects between the embryo and mare.

Improving medical students' knowledge of genetic disease: a review of current and emerging pedagogical practices

Genetics is an essential subject to be mastered by health professional students of all types. However, technological advances in genomics and recent pedagogical research have changed the way in which many medical training programs teach genetics to their students. These advances favor a more experience-based education focused primarily on developing student's critical thinking skills. In this review, we examine the current state of genetics education at both the preclinical and clinical levels and the ways in which medical and pedagogical research have guided reforms to current and emerging teaching practices in genetics. We discover exciting trends taking place in which genetics is integrated with other scientific disciplines both horizontally and vertically across medical curricula to emphasize training in scientific critical thinking skills among students via the evaluation of clinical evidence and consultation of online databases. These trends will produce future health professionals with the skills and confidence necessary to embrace the new tools of medical practice that have emerged from scientific advances in genetics, genomics, and bioinformatics.

Pediatric brainstem gangliogliomas show BRAF(V600E) mutation in a high percentage of cases

Brainstem gangliogliomas (GGs), often cannot be resected, have a much poorer prognosis than those located in more common supratentorial sites and may benefit from novel therapeutic approaches. Therapeutically targetable BRAF c.1799T>A (p.V600E) (BRAF(V600E) ) mutations are harbored in roughly 50% of collective GGs taken from all anatomical sites. Large numbers of pediatric brainstem GGs, however, have not been specifically assessed and anatomic-and age-restricted assessment of genetic and biological factors are becoming increasingly important. Pediatric brainstem GGs (n = 13), non-brainstem GGs (n = 11) and brainstem pilocytic astrocytomas (PAs) (n = 8) were screened by standard Sanger DNA sequencing of BRAF exon 15. Five of 13 (38%) pediatric GG harbored a definitive BRAF(V600E) mutation, with two others exhibiting an equivocal result by this method. BRAF(V600E) was also seen in five of 11 (45%) non-brainstem GGs and one of eight (13%) brainstem PAs. VE1 immunostaining for BRAF(V600E) showed concordance with sequencing in nine of nine brainstem GGs including the two cases equivocal by Sanger. The equivocal brainstem GGs were subsequently shown to harbor BRAF(V600E) using a novel, more sensitive, RNA-sequencing approach, yielding a final BRAF(V600E) mutation frequency of 54% (seven of 13) in brainstem GGs. BRAF(V600E) -targeted therapeutics should be a consideration for the high percentage of pediatric brainstem GGs refractory to conventional therapies.

Prolonged remission of advanced bronchoalveolar adenocarcinoma in a dog treated with autologous, tumour-derived chaperone-rich cell lysate (CRCL) vaccine

PURPOSE

This paper presents the treatment of a 12-year-old female spayed Great Dane who presented with vestibular signs (ataxia, nystagmus, hind end collapse). Thoracic radiographs revealed a discrete pulmonary nodule in the right cranial lung lobe. Ultrasound-guided fine needle aspirate detected primary bronchoalveolar adenocarcinoma, verified via computed tomography, with a second smaller nodule discovered in the right cranial lung lobe.

MATERIALS AND METHODS

A lateral thoracotomy with right cranial lung lobectomy was performed. Histopathological analysis of the nodules and an excised lymph node identified grade III bronchoalveolar adenocarcinoma with vascular infiltration and lymph node metastasis - a grim diagnosis with a reported median survival time of 6-27 days. A 10-g sample of the tumour was processed into a chaperone-rich cell lysate (CRCL) vaccine, which was administered weekly to the patient. Imiquimod - a Toll-like receptor 7 (TLR7) agonist - was applied topically for the first 12 treatments to stimulate local Langerhans cells. A single injection of bacillus Calmette-Guerin (BCG) was administered for additional immune stimulation at week 30 of treatment.

RESULTS

The dog remained stable and in otherwise good health until diffuse relapse occurred 44 weeks after the initial treatment; following gastrointestinal bleeding, the dog was euthanised 50+ weeks post diagnosis.

CONCLUSION

To the authors' knowledge, this is the first report of significantly prolonged survival following a diagnosis of grade III/stage III bronchoalveolar adenocarcinoma in a canine patient. This case report suggests that CRCL vaccine combined with topical imiquimod is a safe, effective treatment for canine tumours.

Standardization of sample collection, isolation and analysis methods in extracellular vesicle research

The emergence of publications on extracellular RNA (exRNA) and extracellular vesicles (EV) has highlighted the potential of these molecules and vehicles as biomarkers of disease and therapeutic targets. These findings have created a paradigm shift, most prominently in the field of oncology, prompting expanded interest in the field and dedication of funds for EV research. At the same time, understanding of EV subtypes, biogenesis, cargo and mechanisms of shuttling remains incomplete. The techniques that can be harnessed to address the many gaps in our current knowledge were the subject of a special workshop of the International Society for Extracellular Vesicles (ISEV) in New York City in October 2012. As part of the “ISEV Research Seminar: Analysis and Function of RNA in Extracellular Vesicles (evRNA)”, 6 round-table discussions were held to provide an evidence-based framework for isolation and analysis of EV, purification and analysis of associated RNA molecules, and molecular engineering of EV for therapeutic intervention. This article arises from the discussion of EV isolation and analysis at that meeting. The conclusions of the round table are supplemented with a review of published materials and our experience. Controversies and outstanding questions are identified that may inform future research and funding priorities. While we emphasize the need for standardization of specimen handling, appropriate normative controls, and isolation and analysis techniques to facilitate comparison of results, we also recognize that continual development and evaluation of techniques will be necessary as new knowledge is amassed. On many points, consensus has not yet been achieved and must be built through the reporting of well-controlled experiments.

Medulloblastoma exosome proteomics yield functional roles for extracellular vesicles

Medulloblastomas are the most prevalent malignant pediatric brain tumors. Survival for these patients has remained largely the same for approximately 20 years, and our therapies for these cancers cause significant health, cognitive, behavioral and developmental sequelae for those who survive the tumor and their treatments. We obviously need a better understanding of the biology of these tumors, particularly with regard to their migratory/invasive behaviors, their proliferative propensity, and their abilities to deflect immune responses. Exosomes, virus-sized membrane vesicles released extracellularly from cells after formation in, and transit thru, the endosomal pathway, may play roles in medulloblastoma pathogenesis but are as yet unstudied in this disease. Here we characterized exosomes from a medulloblastoma cell line with biochemical and proteomic analyses, and included characterization of patient serum exosomes. Further scrutiny of the proteomic data suggested functional properties of the exosomes that are relevant to medulloblastoma tumor biology, including their roles as proliferation stimulants, their activities as attractants for tumor cell migration, and their immune modulatory impacts on lymphocytes. Aspects of this held true for exosomes from other medulloblastoma cell lines as well. Additionally, pathway analyses suggested a possible role for the transcription factor hepatocyte nuclear factor 4 alpha (HNF4A); however, inhibition of the protein’s activity actually increased D283MED cell proliferation/clonogenecity, suggesting that HNF4A may act as a tumor suppressor in this cell line. Our work demonstrates that relevant functional properties of exosomes may be derived from appropriate proteomic analyses, which translate into mechanisms of tumor pathophysiology harbored in these extracellular vesicles.

Clinical and molecular characteristics of congenital glioblastoma

Congenital glioblastoma (cGBM) is an uncommon tumor of infancy with a reported variable but often poor cure rate, even with intensive therapy. Five patients with cGBMs, arising de novo and not in familial tumor predisposition kindreds, were studied for histological and biological features, using Affymetrix microarray. Tumors were large, often associated with hemorrhage, extended into the thalamus, and often bulged into the ventricles. One patient died acutely from bleeding at the time of operation. The 4 surviving patients underwent surgery (1 gross total resection, 3 subtotal resections or biopsies) and moderate intensity chemotherapy without radiation, and remain progression-free at a median time of 36 months (range, 30-110 months). Affymetrix microarrays measured gene expression on the 3 cGBMs from which frozen tissue was available. Unsupervised hierarchical clustering of cGBMs versus 168 other central nervous system tumors demonstrated that cGBMs clustered most closely with other high-grade gliomas. Gene expression profiles of cGBMs were compared with non-congenital pediatric and adult GBMs. cGBMs demonstrated marked similarity to both pediatric and adult GBMs, with only 31 differentially expressed genes identified (false discovery rate, <0.05). Unique molecular features of cGBMs included over-expression of multiple genes involved in glucose metabolism and tissue hypoxia. cGBMs show histological and biological overlap with pediatric and adult GBMs but appear to have a more favorable outcome, with good response to moderate intensity chemotherapy with only subtotal resection or biopsy. Further study may determine whether identified gene expression differences contribute to the improved survival seen in these tumors.

MIR29B regulates expression of MLLT11 (AF1Q), an MLL fusion partner, and low MIR29B expression associates with adverse cytogenetics and poor overall survival in AML

MLLT11, an MLL fusion partner, is a poor prognostic biomarker for paediatric acute myeloid leukaemia (AML), adult normal cytogenetics AML, and adult myelodysplastic syndrome. MLLT11 is highly regulated during haematopoietic progenitor differentiation and development but its regulatory mechanisms have not been defined. In this study, we demonstrate by transfection experiments that MIR29B directly regulates MLLT11 expression in vitro. MIR29B expression level was also inversely related to MLLT11 expression in a cohort of 56 AML patients (P<0·05). AML patients with low MIR29B/elevated MLLT11 expression had poor overall survival (P=0·038). Therefore, MIR29B may be a potential prognostic biomarker for AML patients.

MicroRNA-137 targets microphthalmia-associated transcription factor in melanoma cell lines

Micropthalmia-associated transcription factor (MITF) is the master regulator of melanocyte development, survival, and function. Frequent alteration in the expression of MITF is detected in melanoma, but the mechanism(s) underlying the alteration in expression have not been completely determined. In these studies, we have identified microRNA-137 (miR-137) as a regulator of MITF expression. The genomic locus of miR-137 at chromosome 1p22 places it in a region of the human genome previously determined to harbor an allele for melanoma susceptibility. Here, we show that expression of mature miR-137 in melanoma cell lines down-regulates MITF expression. Further, we have identified a 15-bp variable nucleotide tandem repeat located just 5' to the pre-miR-137 sequence, which alters the processing and function of miR-137 in melanoma cell lines.

EGFR regulation by microRNA in lung cancer: correlation with clinical response and survival to gefitinib and EGFR expression in cell lines

BACKGROUND

Allelic loss in chromosome 3p is one of the most frequent and earliest genetic events in lung carcinogenesis. We investigated if the loss of microRNA-128b, a microRNA located on chromosome 3p and a putative regulator of epidermal growth factor receptor (EGFR), correlated with response to targeted EGFR inhibition. Loss of microRNA-128b would be equivalent to losing a tumor suppressor gene because it would allow increased expression of EGFR.

PATIENTS AND METHODS

We initially showed that microRNA-128b is a regulator of EGFR in non-small-cell lung cancer (NSCLC) cell lines. We tested microRNA-128b expression levels by quantitative RT-PCR, genomic copy number by quantitative PCR, and mutations in the mature microRNA-128b by sequencing. We determined whether microRNA-128b loss of heterozygosity (LOH) in 58 NSCLC patient samples correlated with response to gefitinib and evaluated EGFR expression and mutation status.

RESULTS

We determined that microRNA-128b directly regulates EGFR. MicroRNA-128b LOH was frequent in tumor samples and correlated significantly with clinical response and survival following gefitinib. EGFR expression and mutation status did not correlate with survival outcome.

CONCLUSION

Identifying microRNA regulators of oncogenes could have far-reaching implications for lung cancer patients including improving patient selection for targeted agents, development of novel therapeutics, or development as early biomarkers of disease.

Effective Educational Strategies Combining Emerging Genetic Science and Native American Cultural Issues

The purpose of this paper is to describe how new topics in genetic science are implemented and evaluated within Genetic Education for Native Americans (GENA®) workshops. These workshops are typically implemented during professional conferences, training programs, Native American meetings and at tribal colleges. As genetic science evolves, public health educators are more and more likely to need to understand increasingly complex components within genetic research. These research discoveries are likely to impact cardiovascular health, cancer treatments, prevention and control of diabetes. The public and patients want to understand health information that affects them personally, as well as their communities. The focus of this paper is on GENA® objective 14 (emerging genetic science: microRNA), but the three 2006 3-hour workshops also addressed excerpts of GENA® objectives 5 and 29. at three meetings: the 2006 summer and fall Disparities Training Programs held in Houston, Texas and the 2006 Society for the Advancement of Chicanos and Native Americans in the Sciences (SACNAS) conference (October, Tampa, Florida). The emphasis on objective 14 is because it was updated during spring 2006 (initial focus was on stem cell research) and selected components of objectives 5 and 20 have been published elsewhere. The paper briefly describes the content, interactive learning opportunity and the evaluation from the three 2006 workshops. The overall findings verify the effectiveness (p value of less than .01) of GENA® to significantly increase knowledge level of workshop participants about emerging genetic science breakthroughs.

Interactive Lesson on the Cell

The purpose of this article is to explain how a basic hands-on lesson about the human cell was developed, implemented and evaluated through Genetic Education for Native Americans (GENA®) workshops.

The effect of flavopiridol on the growth of p16+ and p16- melanoma cell lines

Flavopiridol is the first cyclin-dependent kinase inhibitor to enter clinical trials. Flavopiridol has been shown to mimic, in part, the effect of the cell cycle control gene p16, which is frequently lost or mutated in malignant melanoma, making it an ideal candidate for targeted therapy in this disease. In these studies we investigated the effect of flavopiridol, at various concentrations, on the growth and gene expression of nine human melanoma cell lines with intact, absent or mutated p16. A cytostatic effect of flavopiridol on the growth of six melanoma cell lines with a mutated or non-expressed p16 (p16-) was seen at low concentrations of flavopiridol (mean 50% inhibitory concentration [IC(50)] = 12.5 nM), while the three melanoma cell lines with intact p16 (p16+) required higher concentrations (mean IC(50) = 25 nM) to produce this effect. Apoptotic cell death increased with increasing concentrations of flavopiridol in both p16- and p16+ cells. Exposure of cells to high flavopiridol concentrations (>100 nM) resulted in decreased expression of genes downstream in the normal p16 cell cycle control pathway (Rb and E2F) and the anti-apoptotic gene BCL2. No change in BCL2 expression was found after exposure to IC(50) concentrations of flavopiridol. These data indicate that flavopiridol in low, clinically achievable concentrations may have significant cytostatic effects, particularly in p16- melanoma cells, and may provide new molecular-based therapies for melanoma, particularly when combined with agents that target anti-apoptotic mechanisms.

The TRC8 hereditary kidney cancer gene suppresses growth and functions with VHL in a common pathway

VHL is part of an SCF related E3-ubiquitin ligase complex with 'gatekeeper' function in renal carcinoma. However, no mutations have been identified in VHL interacting proteins in wild type VHL tumors. We previously reported that the TRC8 gene was interrupted by a t(3;8) translocation in a family with hereditary renal and non-medullary thyroid cancer. TRC8 encodes a multi-membrane spanning protein containing a RING-H2 finger with in vitro ubiquitin ligase activity. We isolated the Drosophila homologue, DTrc8, and studied its function by genetic manipulations and a yeast 2-hybrid screen. Human and Drosophila TRC8 proteins localize to the endoplasmic reticulum. Loss of either DTrc8 or DVhl resulted in an identical ventral midline defect. Direct interaction between DTrc8 and DVhl was confirmed by GST-pulldown and co-immunoprecipitation experiments. CSN-5/JAB1 is a component of the COP9 signalosome, recently shown to regulate SCF function. We found that DTrc8 physically interacts with CSN-5 and that human JAB1 localization is dependent on VHL mutant status. Lastly, overexpression of DTrc8 inhibited growth consistent with its presumed role as a tumor suppressor gene. Thus, VHL, TRC8, and JAB1 appear to be linked both physically and functionally and all three may participate in the development of kidney cancer.

Native American recommendations for genetic research to be culturally respectful

This article describes genetic research issues and recommendations identified by inter-tribal Native American groups in meetings with tribal leaders from 1995 through 1999.

Native American cancer education: genetic and cultural issues

BACKGROUND

The authors met with intertribal groups to learn about cultural issues related to cancer genetics. The information gathered from these meetings identified issues that are incorporated into the Genetic Education for Native Americans (GENA) interactive, innovative and multidisciplinary curriculum.

METHODS

To address the diverse cultural and scientific issues, the faculty presented customized workshops during conferences for Native American college students.

RESULTS

The authors discuss current issues and techniques in cancer education in Native American communities.

CONCLUSIONS

Better understanding of tribal culture among researchers will enhance Native Americans' collaboration in research.

Reproductive state of rat mammary gland stroma modulates human breast cancer cell migration and invasion

It has been established that the invasive behavior of cancer cells can be regulated by alterations in their extracellular environment. We investigated whether extracellular matrix isolated from nulliparous and postlactating (involuting) rat mammary glands differentially modulated the metastatic behavior of human breast cancer cells. Using modified Boyden chamber and three-dimensional culture assays, nulliparous mammary matrix was found to suppress motility and invasion in highly metastatic MDA-MB-435 cells, whereas involution mammary matrix supported motility and invasion in highly metastatic MDA-MB-435 cells, but not in cells with low metastatic potential. Biochemical characterization of the matrices revealed intact fibronectin (FN) and low matrix metalloproteinase activity in nulliparous mammary matrix and fragmented FN and high matrix metalloproteinase activity in the matrix isolated from involuting glands. Purified intact FN was found to inhibit cell invasiveness, whereas FN fragments enhanced cell invasiveness in a matrix metalloproteinase-dependent manner. These data suggest that physiological changes that occur in the mammary extracellular matrix as a result of reproductive status alter the in vitro parameters of metastatic potential.

Use of the yeast two-hybrid system for identifying the cascade of protein interactions resulting in apoptotic cell death

Use of the yeast two-hybrid system allows rapid identification of interacting protein or proteins for a specific target protein. The technique is readily applied and allows immediate isolation of a cDNA encoding the interacting protein. One consideration might be to outline criteria for continued study of the interactors once they are identified. Our criterion for further study of an interactor is its presence in the mammary gland at a developmental time when the target protein is also present. Further characterization of interactors may involve immunoprecipitation, enzyme assays, or other techniques applicable to the specific protein.

Programmed cell death during mammary gland involution

Understanding the cascade of gene expression and subsequent protein interactions that result both in the death of secretory mammary epithelium and the remodeling and renewal of the mammary gland for another cycle of lactation poses significant challenges (see Chapters 7 and 8, this volume). The complexity of mammary gland involution warrants caution in sorting through the various potential regulators and executors of apoptotic cell death in the mammary gland. As demonstrated by the number of remodeling enzymes expressed during involution, the relationship between mammary epithelium and its related mesenchyme is important for maintenance of differentiated function (Barcellos-Hoff et al., 1989; Streuli et al., 1991). Components of the extracellular matrix may play the role of survival factors, or may provide a source of factors, as a reserve of matrix-bound growth factors, necessary for survival of the secretory epithelium. Perturbation of this interaction alters mammary-specific differentiation gene expression, for example, production of milk proteins (Parry et al., 1987; Strange et al., 1991; Talhouk et al., 1992). Thus, alteration of the interaction between epithelium and its associated mesenchyme, which is an integral part of mammary involution, may also play a role in epithelial cell death. However, the epithelial-mesenchymal interactions that are the determining features in either mediating or modulating this cell death are just beginning to be defined. Stimuli that alter differentiated function may also induce apoptotic cell death of the epithelium but may have no physiological correlate. They may, however, have significant application in prevention or control of breast neoplasia.

Cloning, expression, and purification of a functional nonacetylated mammalian mitochondrial chaperonin 10

An intact mouse mitochondrial chaperonin 10 has been cloned, sequenced, and overexpressed in Escherichia coli as a fusion protein harboring an oligohistidine tail at its COOH terminus. The latter was added to simplify protein purification. The purified protein is free of contaminating groES from the bacterial host cells. Edman degradation reveals that the initiator Met residue of the recombinant protein is removed in vivo, similar to the authentic chaperonin 10 purified from rat liver mitochondria. However, in contrast to the latter, the amino-terminal Ala residue of the recombinant protein is not acetylated; the molecular mass determined by electrospray ionization mass spectrometry is 12,350.9 +/- 2.6 daltons, in agreement with that predicted for the nonacetylated protein (12,351.2 daltons). Facilitated protein folding experiments with ribulose-biphosphate carboxylase, under "nonpermissive" in vitro conditions, demonstrate that the recombinant protein is fully functional with groEL. Thus, both the initial rates of protein folding and final yields observed with this heterologous combination are virtually identical to those obtained with groEL and groES. More important, like the authentic protein purified from mitochondria, the recombinant mitochondrial chaperonin 10, but not groES, is functionally compatible with the heptameric chaperonin 60 of mammalian mitochondria.

ADR1c mutations enhance the ability of ADR1 to activate transcription by a mechanism that is independent of effects on cyclic AMP-dependent protein kinase phosphorylation of Ser-230

Four ADR1c mutations that occur close to Ser-230 of the Saccharomyces cerevisiae transcriptional activator ADR1 and which greatly enhance the ability of ADR1 to activate ADH2 expression under glucose-repressed conditions have been shown to reduce or eliminate cyclic AMP-dependent protein kinase (cAPK) phosphorylation of Ser-230 in vitro. In addition, unregulated cAPK expression in vivo blocks ADH2 depression in an ADR1-dependent fashion in which ADR1c mutations display decreased sensitivity to unregulated cAPK activity. Taken together, these data have suggested that ADR1c mutations enhance ADR1 activity by blocking cAPK phosphorylation and inactivation of Ser-230. We have isolated and characterized an additional 17 ADR1c mutations, defining 10 different amino acid changes, that were located in the region defined by amino acids 227 through 239 of ADR1. Three observations, however, indicate that the ADR1c phenotype is not simply equivalent to a lack of cAPK phosphorylation. First, only some of these newly isolated ADR1c mutations affected the ability of yeast cAPK to phosphorylate corresponding synthetic peptides modeled on the 222 to 234 region of ADR1 in vitro. Second, we observed that strains lacking cAPK activity did not display enhanced ADH2 expression under glucose growth conditions. Third, when Ser-230 was mutated to a nonphosphorylatable residue, lack of cAPK activity led to a substantial increase in ADH2 expression under glucose-repressed conditions. Thus, while cAPK controls ADH2 expression and ADR1 is required for this control, cAPK acts by a mechanism that is independent of effects on ADR1 Ser-230. It was also observed that deletion of the ADR1c region resulted in an ADR1c phenotype. The ADR1c region is, therefore, involved in maintaining ADR1 in an inactive form. ADR1c mutations may block the binding of a repressor to ADR1 or alter the structure of ADR1 so that transcriptional activation regions become unmasked.

Characterization of the adr1-1 nonsense mutation identifies the translational start of the yeast transcriptional activator ADR1

We have characterized a nonsense mutation in the ADR1 gene that identifies the translational start of the ADR1 protein. The ADR1 gene of Saccharomyces cerevisiae is required for synthesis of the glucose-repressible alcohol dehydrogenase (ADH2). The adr1-1 mutation, which inhibits ADH2 expression, was identified as a C to G transversion at base pair +32. This alteration would result in a UGA nonsense codon in place of a serine codon that would lead to termination of the ADR1 polypeptide after the 10th amino acid. The effect of the adr1-1 mutation was partially reversed by UGA-tRNA suppressors, indicating that the adr1-1 mutation affects ADR1 expression at the translational level. These observations establish that the first available AUG in the ADR1 sequence is used as the translational start site of ADR1. Tyrosine or leucine UGA-tRNA-suppressors resulted in levels of adr1-1 activity similar to that found for a serine UGA-tRNA-suppressor, suggesting that serine residue-11 is not essential to ADR1 function. Northern analyses showed that the 5.1 kb ADR1 mRNA was two- to three-fold more abundant when isolated from a strain carrying the ADR1 allele than from an isogenic strain containing the adr1-1 allele. These data confirm that the 5.1 kb mRNA is the ADR1 mRNA and suggest that inhibition of adr1-1 mRNA translation results in more rapid degradation of the adr1-1 mRNA.

Identification of functional regions in the yeast transcriptional activator ADR1

The transcriptional activator ADR1 from Saccharomyces cerevisiae is a postulated DNA-binding protein that controls the expression of the glucose-repressible alcohol dehydrogenase (ADH2). Carboxy-terminal deletions of the ADR1 protein (1,323 amino acids in length) were used to localize its functional regions. The transcriptional activation region was localized to the N-terminal 220 amino acids of ADR1 containing two DNA-binding zinc finger motifs. In addition to the N terminus, a large part of the ADR1 sequence was shown to be essential for complete activation of ADH2. Deletion of the putative phosphorylation region, defined by ADR1c mutations that overcome glucose repression, did not render ADH2 expression insensitive to glucose repression. Instead, this region (amino acids 220 through 253) was found to be required by ADR1 to bypass glucose repression. These results suggest that ADR1c mutations enhance ADR1 function, rather than block an interaction of the putative phosphorylation region with a repressor molecule. Furthermore, the protein kinase CCR1 was shown to affect ADH2 expression when the putative phosphorylation region was removed, indicating that CCR1 does not act solely through this region. A functional ADR1 gene was also found to be necessary for growth on glycerol-containing medium. The N-terminal 506 amino acids of ADR1 were required for this newly identified function, indicating that ADH2 activation and glycerol growth are controlled by separate regions of ADR1.