Abstract 520: MYB exhibits racially disparate overexpression and clinicopathologic association in prostate cancer: significance as a predictor of biochemical recurrence

Prostate cancer (PCa) is the most diagnosed non-cutaneous malignancy and the second leading cause of cancer-related death in American men. Significant racial disparities also exist in incidence and clinical outcome. African American (AA) men are nearly two times more likely to be diagnosed with PCa and have more than twice mortality rate than their Caucasian American (CA) counterparts. Despite an early diagnosis in majority of the cases, about one-third patients face biochemical recurrence following local therapy, with a likelihood of developing distant metastasis. Gleason score used as a prognosticator exhibits discrepancy between AA and CA men highlighting the need for better predictive markers. We previously demonstrated functional significance of MYB in PCa growth, aggressiveness, and castration-resistance. We also showed a role of MYB in sustained androgen receptor (AR) signaling under androgen-deprived condition and prostate-specific antigen (PSA) expression. Here, we studied the expression of MYB in PCa by immunohistochemistry and examined if it varied between AA and CA PCa cases and had any clinicopathological correlation. A total of 105 PCa [CA (n=50) and AA (n=55)] cases with available clinicopathologic data were included. MYB expression was also studied in adjacent benign prostatic hyperplasia (BPH) and high-grade prostate intraepithelial neoplastic (HGPIN) lesions. Stained slides were scanned and digitally analyzed for the measurement of percent positivity (0-100%) and staining intensity (1+, 2+ and 3+). Significant overexpression of MYB (p<0.0001) was reported in PCa relative to HGPIN and BPH. PCa predominantly exhibited moderate to strong staining, compared to weak to moderate staining with low precent positivity rate in HGPIN and weak MYB staining with low percent positivity in BPH. A significantly higher expression of MYB (p<0.0001) was noted in high Gleason score (8-9) PCa, compared to the low-medium Gleason score (≤7) PCa. Interestingly, MYB expression was significantly (p= 0.024) higher in AA PCa than CA PCa in overall and Gleason score wise comparisons. Correlation analysis of MYB showed its inverse association with time to BCR (r =-0.467, 95% CI=-0.675 to -0.190, p=0.002). Altogether, our findings establish MYB as a potentially useful biomarker for PCa diagnosis and prognosis and provide clinical support to our prior findings on the pathobiological role of MYB in PCa.

Citation Format: Mohammad Aslam Khan, Srijan Acharya, Shashi Anand, Fnu Sameeta, James E. Carter, Oliver J. Semmes, Dean A. Troyer, Seema Singh, Santanu Dasgupta, Ajay P. Singh. MYB exhibits racially disparate overexpression and clinicopathologic association in prostate cancer: significance as a predictor of biochemical recurrence [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 520.

A Systems-Based Morbidity and Mortality Conference Was Associated With a Transient Reduction in ECG Completion Times

BACKGROUND AND OBJECTIVES

During its monthly morbidity and mortality conference (MMC), the University of Colorado Division of Cardiology reviewed a "near-miss" patient safety event involving the delayed completion of a Stat-priority (ie, statim, meaning high priority) electrocardiogram (ECG). Because critical and interprofessional stakeholders participated in the conference, we hypothesized that the MMC would be associated with reduced ECG completion times.

METHODS

Data were collected for in-hospital ECGs performed at the University of Colorado Hospital between January 1, 2017, and June 30, 2018. An interrupted time series analysis was used to estimate the immediate and ongoing impact of the MMC (held on February 28, 2018) on ECG completion times, stratified by order priority (Stat, Now, or Routine). The percentage of delayed Stat-priority ECGs was analyzed as a secondary outcome.

RESULTS

Before the MMC, ECG completion times were stable for all order priorities ( P > .2), but the proportion of delayed Stat-priority ECGs increased from 5% in January 2017 to 20% in February 2018 ( P < .01). The MMC was associated with an immediate reduction in average daily ECG completion times for Routine (-18.4 minutes, P = .03) and Now (-8 minutes, P = .024) priority ECGs. No reduction was seen for Stat ECGs ( P = .97), though the percentage of delayed Stat ECGs stopped increasing ( P = .63). In the post-MMC period, completion times for Routine-priority ECGs increased and approached pre-MMC levels.

CONCLUSIONS

The MMC was associated with an immediate, but temporary, improvement in ECG completion times. Although the observed clinical benefit of the MMC is novel, these data support the need for more durable reforms to sustain initial improvements.

Abstract 2609: A novel MYB-AR cross-talk promoting castration-resistance in prostate cancer

Progression of prostate cancer from castration-sensitive to castration-resistant disease is a complex process, which likely involves multiple genetic and epigenetic alterations. Here we report a novel mechanism where MYB acts as a novel binding partner of AR enabling its ligand-independent activation to support castration resistance in prostate cancer. MYB and AR interact and co-localize with each other predominantly in the nuclei. Androgen-depletion or enzalutamide treatment does not interfere with MYB-AR interaction, and MYB-overexpressing prostate cancer cells retain AR in the nucleus even when cultured under androgen-deprived condition. Transcriptional activity of KLK3 (an androgen-responsive gene encoding PSA) promoter is increased in MYB-overexpressing cells, while sustained under androgen-depleted condition. In silico analysis identifies a MYB-binding region in KLK3 promoter in close proximity to the AR binding site, and MYB is shown to cooperatively promote AR binding to the KLK3 promoter. MYB-overexpressing prostate cancer cells exhibit greater tumorigenicity when implanted orthotopically and quickly regain growth following castration leading to the poorer survival of mice, compared to those carrying low MYB-expressing prostate tumors. Together, these findings establish a novel and significant role of MYB-AR cross-talk in prostate cancer, which could be exploited for its therapeutic management.

Citation Format: Sanjeev Kumar Srivastava, Haseeb Zubair, Girijesh K. Patel, Mohammad Aslam Khan, Sachin Kumar Deshmukh, Seema Sing, Joel Andrews, Bin Wang, James E. Carter, Ajay Pratap Singh. A novel MYB-AR cross-talk promoting castration-resistance in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2609.

Young-onset dementia and the need for specialist care: a national and international perspective

OBJECTIVES

Receiving a timely and accurate diagnosis and gaining access to age-appropriate support for younger people living with dementia (YPD) remains a challenge both in the UK and internationally because the focus of most dementia services is primarily upon the needs of older people. The political case to improve services for YPD depends upon the establishment of an understanding of the clinical symptoms, an unequivocal evidence base about need and an accurate evaluation of the size of the population affected. This short report assesses the evidence base from international studies regarding service design and delivery. The goal is to raise awareness, advance best practice and galvanise the international community to address the serious underfunding and underprovision of care for this marginalised group.

CONCLUSION

The current evidence suggests that there are universal problems, regardless of continent, with delays to diagnosis and poor understanding of optimum models for service provision and long-term care.

ETV4 Facilitates Cell-Cycle Progression in Pancreatic Cells through Transcriptional Regulation of Cyclin D1

The ETS family transcription factor ETV4 is aberrantly expressed in a variety of human tumors and plays an important role in carcinogenesis through upregulation of relevant target gene expression. Here, it is demonstrated that ETV4 is overexpressed in pancreatic cancer tissues as compared with the normal pancreas, and is associated with enhanced growth and rapid cell-cycle progression of pancreatic cancer cells. ETV4 expression was silenced through stable expression of a specific short hairpin RNA (shRNA) in two pancreatic cancer cell lines (ASPC1 and Colo357), while it was ectopically expressed in BXPC3 cells. Silencing of ETV4 in ASPC1 and Colo357 cells reduced the growth by 55.3% and 38.9%, respectively, while forced expression of ETV4 in BXPC3 cells increased the growth by 46.8% in comparison with respective control cells. Furthermore, ETV4-induced cell growth was facilitated by rapid transition of cells from G₁- to S-phase of the cell cycle. Mechanistic studies revealed that ETV4 directly regulates the expression of Cyclin D1 CCND1, a protein crucial for cell-cycle progression from G₁- to S-phase. These effects on the growth and cell cycle were reversed by the forced expression of Cyclin D1 in ETV4-silenced pancreatic cancer cells. Altogether, these data provide the first experimental evidence for a functional role of ETV4 in pancreatic cancer growth and cell-cycle progression.Implications: The functional and mechanistic data presented here regarding ETV4 in pancreatic cancer growth and cell-cycle progression suggest that ETV4 could serve as a potential biomarker and novel target for pancreatic cancer therapy. Mol Cancer Res; 16(2); 187-96. ©2017 AACR.

Emerging evidence for the role of differential tumor microenvironment in breast cancer racial disparity: a closer look at the surroundings

Although increased awareness leading to early detection and prevention, as well as advancements in treatment strategies, have resulted in superior clinical outcomes, African American women with breast cancer continue to have greater mortality rates, compared to Caucasian American counterparts. Moreover, African American women are more likely to have breast cancer at a younger age and be diagnosed with aggressive tumor sub-types. Such racial disparities can be attributed to socioeconomic differences, but it is increasingly being recognized that these disparities may indeed be due to certain genetic and other non-genetic biological differences. Tumor microenvironment, which provides a favorable niche for the growth of tumor cells, is comprised of several types of stromal cells and the various proteins secreted as a consequence of bi-directional tumor-stromal cross-talk. Emerging evidence suggests inherent biological differences in the tumor microenvironment of breast cancer patients from different racial backgrounds. Tumor microenvironment components, affected by the genetic make-up of the tumor cells as well as other non-tumor-associated factors, may also render patients more susceptible to the development of aggressive tumors and faster progression of disease resulting in early onset, thus adversely affecting patients' survival. This review provides an overview of breast cancer racial disparity and discusses the existence of race-associated differential tumor microenvironment and its underlying genetic and non-genetic causal factors. A better understanding of these aspects would help further research on effective cancer management and improved approaches for reducing the racial disparities gaps in breast cancer patients.

Honokiol suppresses pancreatic tumor growth, metastasis and desmoplasia by interfering with tumor-stromal cross-talk

The poor clinical outcome of pancreatic cancer (PC) is largely attributed to its aggressive nature and refractoriness to currently available therapeutic modalities. We previously reported antitumor efficacy of honokiol (HNK), a phytochemical isolated from various parts of Magnolia plant, against PC cells in short-term in vitro growth assays. Here, we report that HNK reduces plating efficiency and anchorage-independent growth of PC cells and suppresses their migration and invasiveness. Furthermore, significant inhibition of pancreatic tumor growth by HNK is observed in orthotopic mouse model along with complete-blockage of distant metastases. Histological examination suggests reduced desmoplasia in tumors from HNK-treated mice, later confirmed by immunohistochemical analyses of myofibroblast and extracellular matrix marker proteins (α-SMA and collagen I, respectively). At the molecular level, HNK treatment leads to decreased expression of sonic hedgehog (SHH) and CXCR4, two established mediators of bidirectional tumor-stromal cross-talk, both in vitro and in vivo . We also show that the conditioned media (CM) from HNK-treated PC cells have little growth-inducing effect on pancreatic stellate cells (PSCs) that could be regained by the addition of exogenous recombinant SHH. Moreover, pretreatment of CM of vehicle-treated PC cells with SHH-neutralizing antibody abolishes their growth-inducing potential on PSCs. Likewise, HNK-treated PC cells respond poorly to CM from PSCs due to decreased CXCR4 expression. Lastly, we show that the transfection of PC cells with constitutively active IKKβ mutant reverses the suppressive effect of HNK on nuclear factor-kappaB activation and partially restores CXCR4 and SHH expression. Taken together, these findings suggest that HNK interferes with tumor-stromal cross-talk via downregulation of CXCR4 and SHH and decreases pancreatic tumor growth and metastasis.

Abstract 949: Resistin potentiates stemness and chemoresistance of breast cancer cells through STAT3 activation: implications in breast cancer health disparity

Breast cancer (BC) is most frequently diagnosed cancer and remains the second leading cause of cancer-related deaths in women in the United States. African American (AA) women bear an additional burden of BC with early onset of disease, poorer prognosis, higher risk of recurrence, and worst clinical outcome as compared to Caucasian American (CA) women. Emerging evidence strongly argue the role of tumor-microenvironment (TME) in BC of AA and CA racial backgrounds. On the similar line, our earlier findings suggested that serum levels of resistin; an inflammatory cytokine are significantly elevated in AA BC patients compared to their CA counterparts. Furthermore, we demonstrated that resistin promoted growth and aggressiveness of BC cells. In the present study, we investigated the role of resistin in stemness and chemoresistance of BC cells. For this, two BC cells of CA (MDA-MB-231) and AA (MDA-MB-468) origin were treated with resistin and sphere-forming ability, a key characteristic of cancer stem cells, was determined. Data demonstrate that number of spheres is significantly enhanced in both the BC cells upon resistin stimulation. Immunoblot analyses reveal that resistin-induced sphere-forming ability is associated with enhanced levels of stemness-associated transcription factors (Nanog and KLF4) in BC cells. We next examined if resistin conferred chemoresistance to BC cells. Our data suggest that resistin-treated MDA-MB-231 and MDA-MB-468 BC cells develop greater resistance against doxorubicin-induced cytotoxicity. Notably, the effects conferred by resistin were more prominent in AA BC cells comparing to CA BC cells. Our mechanistic studies unveiled an important role of STAT3 activation in the resistin-induced stemness and chemoresistance of BC cells. Taken together, our findings provide novel insight into the role of resistin in BC biology and further strengthen its role in racially disparate clinical outcomes.

Citation Format: Sachin Kumar Deshmukh, Arun Bhardwaj, Sanjeev K. Srivastava, Nikhil Tyagi, Ahmed Al-Ghadhban, Ajay P. Singh, Donna L. Dyess, James E. Carter, Seema Singh. Resistin potentiates stemness and chemoresistance of breast cancer cells through STAT3 activation: implications in breast cancer health disparity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 949. doi:10.1158/1538-7445.AM2017-949

Resistin potentiates chemoresistance and stemness of breast cancer cells: Implications for racially disparate therapeutic outcomes

Breast cancer (BC) continues to be the most frequently diagnosed cancer in American women, which disproportionately affects women of African-American (AA) descent. Previously, we reported greater serum levels of resistin in AA BC patients relative to Caucasian-American (CA) patients, and established its role in growth and aggressiveness of breast tumor cells. Here we have investigated the role of resistin in BC-chemoresistance. MDA-MB-231 and MDA-MB-468 BC cells of CA and AA origin, respectively, were incubated with resistin prior to doxorubicin treatment. Our data suggest that resistin conferred chemoresistance to both BC cell lines; however, the effect on AA cells was more profound. Furthermore, the resistin-induced doxorubicin-resistance was shown to occur due to suppression of apoptosis. Resistin treatment also affected the stemness of BC cells, as suggested by reduced cell surface expression of CD24, induced expression of CD44 and ALDH1, and increased capability of cells to form mammospheres. Mechanistic studies revealed that resistin-induced chemoresistance, apoptosis and stemness of BC cells were mediated through STAT3 activation. Taken together, our findings provide novel insight into the role of resistin in BC biology, and strengthen its role in racially disparate clinical outcomes.

Racial disparities in prostate cancer: a molecular perspective

Prostate cancer incidence and mortality rates are remarkably higher in African-American men as compared to their European-Americans counterparts. Despite these recognitions, precise causes underlying such prevalent racial disparities remain poorly understood. Although socioeconomic factors could account for such differences up to a certain extent, it is now being increasingly realized that such disparity has a molecular basis. Indeed, several differences, including genetic polymorphism, gene mutations, epigenetic modifications, miRNAs alterations, etc., have been reported in malignant prostate tissues from patients of diverse racial backgrounds. Here, we attempt to provide a molecular perspective on prostate cancer racial disparities by gathering available information on these associated factors and discussing their potential significance in disproportionate incidence and clinical outcomes.

Gemcitabine triggers angiogenesis-promoting molecular signals in pancreatic cancer cells: Therapeutic implications

Pancreatic tumor microenvironment (TME) is characterized by poor tumor-vasculature and extensive desmoplasia that together contribute to poor response to chemotherapy. It was recently shown that targeting of TME to inhibit desmoplasiatic reaction in a preclinical model resulted in increased microvessel-density and intratumoral drug concentration, leading to improved therapeutic response. This approach; however, failed to generate a favorable response in clinical trial. In that regard, we have previously demonstrated a role of gemcitabine-induced CXCR4 signaling as a counter-defense mechanism, which also promoted invasiveness of pancreatic cancer (PC) cells. Here, we investigated the effect of gemcitabine on endothelial cell phenotype. Gemcitabine-treatment of human-umbilical-vein-endothelial-cells (HUVECs) did not promote the growth of HUVECs; however, it was induced when treated with conditioned media from gemcitabine-treated (Gem-CM) PC cells due to increased cell-cycle progression and apoptotic-resistance. Moreover, treatment of HUVECs with Gem-CM resulted in capillary-like structure (CLS) formation and promoted their ability to migrate and invade through extracellular-matrix. Gemcitabine-treatment of PC cells induced expression of various growth factors/cytokines, including IL-8, which exhibited greatest upregulation. Further, IL-8 depletion in Gem-CM diminished its potency to promote angiogenic phenotypes. Together, these findings suggest an indirect effect of gemcitabine on angiogenesis, which, in light of our previous observations, may hold important clinical significance.

Comparative analysis of the relative potential of silver, Zinc-oxide and titanium-dioxide nanoparticles against UVB-induced DNA damage for the prevention of skin carcinogenesis

Sunscreen formulations containing UVB filters, such as Zinc-oxide (ZnO) and titanium-dioxide (TiO2) nanoparticles (NPs) have been developed to limit the exposure of human skin to UV-radiations. Unfortunately, these UVB protective agents have failed in controlling the skin cancer incidence. We recently demonstrated that silver nanoparticles (Ag-NPs) could serve as novel protective agents against UVB-radiations. Here our goal was to perform comparative analysis of direct and indirect UVB-protection efficacy of ZnO-, TiO2- and Ag-NPs. Sun-protection-factor calculated based on their UVB-reflective/absorption abilities was the highest for TiO2-NPs followed by Ag- and ZnO-NPs. This was further confirmed by studying indirect protection of UVB radiation-induced death of HaCaT cells. However, only Ag-NPs were active in protecting HaCaT cells against direct UVB-induced DNA-damage by repairing bulky-DNA lesions through nucleotide-excision-repair mechanism. Moreover, Ag-NPs were also effective in protecting HaCaT cells from UVB-induced oxidative DNA damage by enhancing SOD/CAT/GPx activity. In contrast, ZnO- and TiO2-NPs not only failed in providing any direct protection from DNA-damage, but rather enhanced oxidative DNA-damage by increasing ROS production. Together, these findings raise concerns about safety of ZnO- and TiO2-NPs and establish superior protective efficacy of Ag-NPs.

Abstract 1988: MYB overexpression is associated with castration-resistance in prostate cancer

Clinical progression of prostate cancer (PCa) is characterized by a transition from castration-sensitive (CS) to castration-resistant (CR) phenotype. We previously demonstrated that MYB overexpression sustained the growth of PCa cells in androgen-depleted growth environment as well as promoted aggressive tumor phenotypes. Here, we examined its role in PCa progression and castration-resistance using appropriate mouse models and delineated underlying molecular mechanisms. Luciferase-tagged MYB-overexpressing (LNCaP-MYB) or -silenced (C4-2-shMYB) PCa cell lines along with their respective control sublines (LNCaP-Neo and C4-2-NTScr) were orthotopically implanted in nude mice and tumor growth was monitored by non-invasive bioluminescence imaging using Xenogen-IVIS optical system. Our data demonstrated significantly enhanced tumor growth in mice implanted with high MYB expressing (LNCaP-MYB and C4-2-NTScr) PCa cells as compared to low MYB expressing (LNCaP-Neo and C4-2-shMYB) cells. To study the role of MYB in castration-resistance, we castrated the mice after tumors from all groups reached comparable size as determined by in vivo imaging. Tumors in LNCaP-Neo and C4-2-shMYB groups exhibited drastic regression following castration. In contrast, only slight initial reduction in the tumor growth was reported in mice from LNCaP-MYB and C4-2-NTScr groups following castration, and they later regained tumor growth. Furthermore, Kaplan-Meier survival analysis revealed that the median survival of testis-intact (non-castrated) animals of LNCaP-Neo and C4-2-shMYB groups was significantly lower than that of castrated group mice. However, castration in high MYB-expressing tumor bearing mice could barely improve their median survival. Interestingly, MYB expression levels in orthotopic tumors correlated with serum PSA levels. Furthermore, castration of mice in LNCaP-Neo and C4-2-shMYB groups resulted in a rapid reduction in serum PSA levels; while it sustained and continued to rise in MYB overexpressing groups. In additional studies, we demonstrated that MYB interacts with androgen-receptor (AR) in prostate cancer cells, and facilitates the nuclear localization of AR in a ligand-independent manner. In essence, these results suggest a critical role of MYB in the CR progression of PCa.

Citation Format: Sanjeev K. Srivastava, Arun Bhardwaj, Seema Singh, Sumit Arora, Nikhil Tyagi, James E. Carter, Ajay P. Singh. MYB overexpression is associated with castration-resistance in prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1988.

MYB Promotes Desmoplasia in Pancreatic Cancer through Direct Transcriptional Up-regulation and Cooperative Action of Sonic Hedgehog and Adrenomedullin

Extensive desmoplasia is a prominent pathological characteristic of pancreatic cancer (PC) that not only impacts tumor development, but therapeutic outcome as well. Recently, we demonstrated a novel role of MYB, an oncogenic transcription factor, in PC growth and metastasis. Here we studied its effect on pancreatic tumor histopathology and associated molecular and biological mechanisms. Tumor-xenografts derived from orthotopic-inoculation of MYB-overexpressing PC cells exhibited far-greater desmoplasia in histological analyses compared with those derived from MYB-silenced PC cells. These findings were further confirmed by immunostaining of tumor-xenograft sections with collagen-I, fibronectin (major extracellular-matrix proteins), and α-SMA (well-characterized marker of myofibroblasts or activated pancreatic stellate cells (PSCs)). Likewise, MYB-overexpressing PC cells provided significantly greater growth benefit to PSCs in a co-culture system as compared with the MYB-silenced cells. Interrogation of deep-sequencing data from MYB-overexpressing versus -silenced PC cells identified Sonic-hedgehog (SHH) and Adrenomedullin (ADM) as two differentially-expressed genes among others, which encode for secretory ligands involved in tumor-stromal cross-talk. In-silico analyses predicted putative MYB-binding sites in SHH and ADM promoters, which was later confirmed by chromatin-immunoprecipitation. A cooperative role of SHH and ADM in growth promotion of PSCs was confirmed in co-culture by using their specific-inhibitors and exogenous recombinant-proteins. Importantly, while SHH acted exclusively in a paracrine fashion on PSCs and influenced the growth of PC cells only indirectly, ADM could directly impact the growth of both PC cells and PSCs. In summary, we identified MYB as novel regulator of pancreatic tumor desmoplasia, which is suggestive of its diverse roles in PC pathobiology.

Resistin and interleukin-6 exhibit racially-disparate expression in breast cancer patients, display molecular association and promote growth and aggressiveness of tumor cells through STAT3 activation

African-American (AA) women with breast cancer (BC) are diagnosed with more aggressive disease, have higher risk of recurrence and poorer prognosis as compared to Caucasian American (CA) women. Therefore, it is imperative to define the factors associated with such disparities to reduce the unequal burden of cancer. Emerging data suggest that inherent differences exist in the tumor microenvironment of AA and CA BC patients, however, its molecular bases and functional impact have remained poorly understood. Here, we conducted cytokine profiling in serum samples from AA and CA BC patients and identified resistin and IL-6 to be the most differentially-expressed cytokines with relative greater expression in AA patients. Resistin and IL-6 exhibited positive correlation in serum levels and treatment of BC cells with resistin led to enhanced production of IL-6. Moreover, resistin also enhanced the expression and phosphorylation of STAT3, and treatment of BC cells with IL-6-neutralizing antibody prior to resistin stimulation abolished STAT3 phosphorylation. In addition, resistin promoted growth and aggressiveness of BC cells, and these effects were mediated through STAT3 activation. Together, these findings suggest a crucial role of resistin, IL-6 and STAT3 in BC racial disparity.

MYB is a novel regulator of pancreatic tumour growth and metastasis

BACKGROUND

MYB encodes for a transcription factor regulating the expression of a wide array of genes involved in cellular functions. It is reported to be amplified in a sub-set of pancreatic cancer (PC) cases; however, its pathobiological association has remained unclear thus far.

METHODS

Expression of MYB and other cellular proteins was analysed by immunoblot or qRT-PCR analyses. MYB was stably overexpressed in non-expressing (BxPC3) and silenced in highly expressing (MiaPaCa and Panc1) PC cells. Effect on growth was analysed by automated cell counting at 24-h interval. Cell-cycle progression and apoptotic indices of PC cells with altered MYB expression were measured through flow cytometry upon staining with respective biomarkers. Cell motility/invasion was examined in a Boyden's chamber assay using non-coated or Matrigel-coated membranes. Effect on tumorigenicity and metastatic potential was examined by non-invasive imaging and through end-point measurements of luciferase-tagged MYB-altered PC implanted in the pancreas of nude mice.

RESULTS

MYB was aberrantly expressed in all malignant cases of pancreas, whereas remained undetectable in normal pancreas. All the tested established PC cell lines except BxPC3 also exhibited MYB expression. Forced expression of MYB in BxPC3 cells promoted their growth, cell-cycle progression, survival and malignant behaviour, whereas its silencing in MiaPaCa and Panc1 cells produced converse effects. More importantly, ectopic MYB expression was sufficient to confer tumorigenic and metastatic capabilities to non-tumorigenic BxPC3 cells, while its silencing resulted in significant loss of the same in MYB-overexpressing cells as demonstrated in orthotopic mouse model. We also identified several MYB-regulated genes in PC cells that might potentially mediate its effect on tumour growth and metastasis.

CONCLUSIONS

MYB is aberrantly overexpressed in PC cells and acts as a key determinant of pancreatic tumour growth and metastasis.

CXCL12/CXCR4 signaling counteracts docetaxel-induced microtubule stabilization via p21-activated kinase 4-dependent activation of LIM domain kinase 1

Emerging data highlight the significance of chemokine (C-X-C motif) ligand 12/chemokine (C-X-C motif) receptor 4 (CXCL12/CXCR4) signaling axis in the chemoresistance of several malignancies, including prostate cancer (PCa); however, underlying mechanisms remain largely elusive. Here, we demonstrate that CXCL12 treatment rescues the PCa cells from docetaxel (DTX)-induced toxicity by overriding its effect on cell cycle (G₂/M phase arrest). We further demonstrate that the chemoprotective effect of CXCL12 is abolished upon pharmacological inhibition or RNA interference-mediated silencing of CXCR4. Moreover, microtubule stabilization caused by DTX is suppressed in CXCL12-stimulated PCa cells as revealed by immunofluorescence and immunoblot analyses. The effect of CXCL12 on microtubule stabilization is abrogated when PCa cells are pre-treated with a CXCR4 antagonist. In additional studies, we show that the chemoprotective action of CXCL12/CXCR4 signaling is mediated by p21-activated kinase 4 (PAK4)-dependent activation of Lim domain kinase 1 (LIMK1), and inhibition of either PAK4 or LIMK1 leads to re-sensitization of PCa cells to DTX-induced tubulin polymerization and cellular toxicity even in the presence of CXCL12. Altogether, our findings uncover a novel mechanism underlying CXCL12/CXCR4 signaling-induced PCa chemoresistance and suggest that targeting of this signaling axis or its downstream effector pathway could lead to therapeutic enhancement of DTX.

Size is an essential parameter in governing the UVB-protective efficacy of silver nanoparticles in human keratinocytes

Background

Ultraviolet (UV) radiation from sun, particularly its UVB component (290–320 nm), is considered the major etiological cause of skin cancer that impacts over 2 million lives in the United States alone. Recently, we reported that polydisperse colloidal suspension of silver nanoparticles (AgNPs) protected the human keratinocytes (HaCaT) against UVB-induced damage, thus indicating their potential for prevention of skin carcinogenesis. Here we sought out to investigate if size controlled the chemopreventive efficacy of AgNPs against UVB-induced DNA damage and apoptosis.

Methods

Percent cell viability was examined by WST-1 assay after treating the cells with various doses (1–10 μg/mL) of AgNPs of different sizes (10, 20, 40, 60 and 100 nm) for 12 and 24 h. For protection studies, cells were treated with AgNPs of different sizes at a uniform concentration of 1 μg/mL. After 3 h, cells were irradiated with UVB (40 mJ/cm²) and dot-blot analysis was performed to detect cyclobutane pyrimidine dimers (CPDs) as an indication of DNA damage. Apoptosis was analyzed by flow cytometry after staining the cells with 7-Amino-Actinomycin (7-AAD) and PE Annexin V. Immunoblot analysis was accomplished by processing the cells for protein extraction and Western blotting using specific antibodies against various proteins.

Results

The data show that the pretreatment of HaCaT cells with AgNPs in the size range of 10–40 nm were effective in protecting the skin cells from UVB radiation-induced DNA damage as validated by reduced amounts of CPDs, whereas no protection was observed with AgNPs of larger sizes (60 and 100 nm). Similarly, only smaller size AgNPs (10–40 nm) were effective in protecting the skin cells from UV radiation-induced apoptosis. At the molecular level, UVB –irradiation of HaCaT cells led to marked increase in expression of pro-apoptotic protein (Bax) and decrease in anti-apoptotic proteins (Bcl-2 and Bcl-xL), while it remained largely unaffected in skin cells pretreated with smaller size AgNPs (10–40 nm).

Conclusions

Altogether, these findings suggest that size is a critical determinant of the UVB-protective efficacy of AgNPs in human keratinocytes.

Abstract 2811: Silver nanoparticles protect human keratinocytes from deleterious effects of ultraviolet radiation: Implications for skin cancer chemoprevention

Skin cancer is the most common form of cancer worldwide and its incidence has been increasing at an alarming rate in the United States. A solar ultraviolet (UV) radiation, particularly UVB, is the main etiological cause of skin carcinogenesis due to its DNA damaging ability. Therefore, multidisciplinary scientific research has placed specific emphasis on finding novel ways for skin cancer chemoprevention. Here, we provide first experimental evidence for chemopreventive efficacy of silver-nanoparticles (AgNPs) against UVB-induced DNA damage and apoptosis in immortalized human epidermal keratinocytes (HaCaT). AgNPs synthesized by chemical reduction method were characterized for their physicochemical properties. The nanoparticles were spherical (&gt; 90%) in shape, in the size range of 20-50 nm, and had net negative surface charge with an average zeta potential of - 47.7 mV. AgNPs were largely non-toxic to HaCaT cells and their pretreatment protected them from UVB-induced apoptosis. Significant reduction in cyclobutane pyrimidine dimer (CPD) formation upon UVB exposure was also observed in AgNPs-pretreated HaCaT cells. In addition, AgNPs pre-treatment leads to G1 phase arrest of cell cycle in UVB-exposed HaCaT cells thus allowing sufficient time for CPDs repair. Moreover, enhanced AgNPs internalization and localization into cytoplasmic and nuclear compartments was observed by UVB irradiated HaCaT cells. Furthermore, AgNPs pretreatment altered the expression of various genes involved in cell-cycle, apoptosis and nucleotide-excision repair in UVB-irradiated HaCaT cells. Together, these findings clearly suggest the potential utility of AgNPs as novel chemopreventive agents against UVB-induced skin carcinogenesis.

Citation Format: Sumit Arora, Nikhil Tyagi, Arun Bhardwaj, Lilia Rusu, Rohan Palanki, Ajay P. Singh, James E. Carter, Seema Singh. Silver nanoparticles protect human keratinocytes from deleterious effects of ultraviolet radiation: Implications for skin cancer chemoprevention. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2811. doi:10.1158/1538-7445.AM2015-2811

Abstract 4182: Gemcitabine triggers angiogenesis-promoting molecular signals in pancreatic cancer cells: Therapeutic implications

Pancreatic tumor microenvironment (TME) is characterized by poor tumor vasculature and extensive desmoplasia that together contribute to poor response to chemotherapy. It was recently shown that targeting of TME to inhibit desmoplastic reaction in a mouse model of pancreatic cancer resulted in increased microvessel density and intratumoral drug concentration, leading to improved therapeutic response. This approach; however, failed to generate a favorable response in a clinical trial. In that regard, we have previously demonstrated that gemcitabine-treatment of pancreatic cancer cells induces CXCR4 expression in a counter-defense mechanism and promotes pancreatic tumor cell invasiveness. The goal of present study was to examine the effect of chemotherapy on endothelial cell growth and migration. Pancreatic cancer cells were treated with gemcitabine or vehicle for 8 h and subsequently incubated in fresh low serum-containing media for next 48 h. Conditioned media was collected from vehicle- (V-CM) and gemcitabine-treated (Gem-CM) pancreatic cancer cells and used for the treatment of human umbilical vein endothelial cells (HUVEC). The data demonstrated stimulatory effects of Gem-CM on endothelial cell proliferation, migration, invasion and capillary-like structure (CLS) formation. Expression analysis of vehicle- and gemcitabine-treated pancreatic cancer cells and their conditioned-media revealed an upregulation of CXCL8/IL8, which is a known regulator of angiogenesis. Currently, we are investigating whether IL8 mediates the effect of Gem-CM on endothelial cells. Together, our findings suggest that gemcitabine triggers angiogenesis-promoting molecular signals in pancreatic cancer cells, which, in light of our previous observations, may hold important clinical and translational significance.

Citation Format: Mohammad Aslam Khan, Sanjeev K. Srivastava, Arun Bhardwaj, Seema Singh, James E. Carter, Ajay P. Singh. Gemcitabine triggers angiogenesis-promoting molecular signals in pancreatic cancer cells: Therapeutic implications. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4182. doi:10.1158/1538-7445.AM2015-4182

p-21 activated kinase 4 promotes proliferation and survival of pancreatic cancer cells through AKT- and ERK-dependent activation of NF-κB pathway

Identification of novel molecular targets and understanding the mechanisms underlying the aggressive nature of pancreatic cancer (PC) remain prime focus areas of research. Here, we investigated the expression and pathobiological significance of p21-activated kinase 4 (PAK4), a gene that was earlier shown to be amplified in a sub-set of PC. Our data demonstrate PAK4 overexpression in PC tissues and cell lines with little or no expression in the normal pancreas. PAK4 silencing in two PC cell lines, MiaPaCa and T3M4, by RNA interference causes suppression of growth and clonogenic ability due to decreased cell cycle progression and apoptosis-resistance. PAK4-silenced PC cells exhibit altered expression of proliferation- and survival-associated proteins. Moreover, we observe decreased nuclear accumulation and transcriptional activity of NF-κB in PAK4-silenced PC cells associated with stabilization of its inhibitory protein, IκBα. Transfection of PAK4-silenced PC cells with constitutively-active mutant of IKKβ, an upstream kinase of IκBα, leads to restoration of NF-κB activity and PC cell growth. Furthermore, we show that PAK4-induced NF-κB activity is mediated through activation and concerted action of ERK and Akt kinases. Together, these findings suggest that PAK4 is a regulator of NF-κB pathway in PC cells and can serve as a novel target for therapy.

Silver nanoparticles protect human keratinocytes against UVB radiation-induced DNA damage and apoptosis: potential for prevention of skin carcinogenesis

Ultraviolet (UV)-B radiation from the sun is an established etiological cause of skin cancer, which afflicts more than a million lives each year in the United States alone. Here, we tested the chemopreventive efficacy of silver-nanoparticles (AgNPs) against UVB-irradiation-induced DNA damage and apoptosis in human immortalized keratinocytes (HaCaT). AgNPs were synthesized by reduction-chemistry and characterized for their physicochemical properties. AgNPs were well tolerated by HaCaT cells and their pretreatment protected them from UVB-irradiation-induced apoptosis along with significant reduction in cyclobutane-pyrimidine-dimer formation. Moreover, AgNPs pre-treatment led to G1-phase cell-cycle arrest in UVB-irradiated HaCaT cells. AgNPs were efficiently internalized in UVB-irradiated cells and localized into cytoplasmic and nuclear compartments. Furthermore, we observed an altered expression of various genes involved in cell-cycle, apoptosis and nucleotide-excision repair in HaCaT cells treated with AgNPs prior to UVB-irradiation. Together, these findings provide support for potential utility of AgNPs as novel chemopreventive agents against UVB-irradiation-induced skin carcinogenesis.

FROM THE CLINICAL EDITOR

Excessive exposure to the sun is known to increase the risk of skin cancer due to DNA damage. In this work, the authors tested the use of silver nanoparticles as protective agents against ultraviolet radiation. The positive results may open a door for the use of silver nanoparticle as novel agents in the future.

Bioavailability of iodine in the UK-Peak District environment and its human bioaccessibility: an assessment of the causes of historical goitre in this area

Iodine is an essential micronutrient for human health. Its deficiency causes a number of functional and developmental abnormalities such as goitre. The limestone region of Derbyshire, UK was goitre-endemic until it declined from the 1930s and the reason for this has escaped a conclusive explanation. The present study investigates the cause(s) of goitre in the UK-Peak District area through an assessment of iodine in terms of its environmental mobility, bioavailability, uptake into the food chain and human bioaccessibility. The goitre-endemic limestone area is compared with the background millstone grit area of the UK-Peak District. The findings of this study show that 'total' environmental iodine is not linked to goitre in the limestone area, but the governing factors include iodine mobility, bioavailability and bioaccessibility. Compared with the millstone grit area, higher soil pH and calcium content of the limestone area restrict iodine mobility in this area, also soil organic carbon in the limestone area is influential in binding the iodine to the soil. Higher calcium content in the limestone area is an important factor in terms of strongly fixing the iodine to the soil. Higher iodine bioaccessibility in the millstone grit than the limestone area suggests that its oral bioaccessibility is restricted in the limestone area. Iodine taken up by plant roots is transported freely into the aerial plant parts in the millstone grit area unlike the limestone area, thus providing higher iodine into the human food chain in the millstone grit area through grazing animals unlike the goitre-prevalent limestone area.

Coronal plane ankle alignment, gait, and end-stage ankle osteoarthritis

OBJECTIVE

Unilateral ankle osteoarthritis (OA) is a debilitating condition which may lead to limb deformity, severe pain, and functional disability due to tibiotalar malalignment and gait dysfunction. The purpose of this study was to determine if coronal plane alignment (varus, valgus, or neutral) of the ankle resulted in different spatial-temporal gait mechanics, clinically-assessed function, and self-reported function in patients with end-stage ankle OA.

METHODS

Following informed consent, 96 patients with end-stage unilateral ankle OA were radiographically categorized as having varus, valgus, or neutral tibiotalar alignment. Each subject completed the foot and ankle disability index (FADI) questionnaire to assess self-reported function. The spatial-temporal parameters of interest (stance time, step length, stride length, stride width, single-support time, double support time, and walking speed) were assessed while the subject walked at a self-selected speed.

RESULTS

The varus group performed the timed up and go test significantly faster than the other groups (P=0.05). All other variables were similar between the three alignment groups.

CONCLUSION

There was little difference in gait mechanics and function between patients with end-stage OA based on coronal plane ankle alignment suggesting that factors other than coronal plane alignment contribute to diminished function.

Outcome of kidney transplantation in Canadian Aboriginal children in the province of British Columbia

Renal transplantation remains the therapy of choice for children and adolescents with ESRD. Differences in graft survival are observed in kidney transplant recipients of different race and ethnicities. Data in pediatric populations are limited and confounded by disparities in access to health care. We performed a retrospective single Canadian centre database review to determine the short- and long-term outcomes of kidney transplantation in Aboriginal children compared to non-Aboriginals. A total of 159 primary renal transplant recipients at BCCH between 1985 and 2005 were examined (15% Aboriginal). Aboriginal children had different etiologies of ESRD, and a higher percentage of females, but were similar in age at transplantation, cold ischemia time and living donation rate. Early graft outcomes such as delayed graft function, episodes of acute rejection in the first year post-transplant and estimated glomerular function rate at one yr were similar in both groups. Long-term graft survival, however, was significantly worse in the Aboriginal group, with a significantly increased rate of late rejections: 50% compared with 26.7% among non-Aboriginals (p = 0.03). In a province with uniform access to health care, significant differences in long-term graft outcome exist among Aboriginal children compared with non-Aboriginals.

Amyloid beta-derived neuroplasticity in bone marrow-derived mesenchymal stem cells is mediated by NPY and 5-HT2B receptors via ERK1/2 signalling pathways

OBJECTIVE

In Alzheimer's disease, toxic soluble and insoluble forms of amyloid beta (Abeta) cause synaptic dysfunction and neuronal loss. Given its potential role in producing a toxic host microenvironment for transplanted donor stem cells, we investigated the interaction between Abeta and proliferation, survival, and differentiation of bone marrow-derived mesenchymal stem cells (BM-MSC) in culture.

MATERIALS AND METHODS

We used BM-MSC that had been isolated from mouse bone marrow and cultured, and we also assessed relevant reaction mechanisms using gene microarray, immunocytochemistry, and inhibitors of potential signalling molecules, such as mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK)1/2 and tyrosine protein kinase.

RESULTS AND CONCLUSIONS

Interestingly, we found that treatment with aggregated (1-40 or 1-42) and oligomeric (1-42) Abeta promoted neuronal-like differentiation of BM-MSC without toxic effects. This was not dependent on soluble factors released from BM-MSC progeny nor solely on formation of Abeta fibrils. The effect of Abeta is mediated by G-protein coupled receptors, neuropeptide Y1 (NPY1R) and serotonin (5-hydroxytryptamine) receptor 2B, via phosphatidylinositol-3-OH kinase-dependent activation of the MAPK/ERK1/2. Our results lend support to the idea that reciprocal donor stem cell-host interactions may promote a regenerative response that can be exploited by epigenetic modulation of NPY/serotonergic gene expression, for stem cell therapy, in Alzheimer's disease.

Erythrophagocytic low-grade extranodal T-cell lymphoma in a cat

A 13-year-old male castrated domestic shorthair cat was presented to the referring veterinarian with a 2-month history of weight loss and lethargy. Splenomegaly, hepatomegaly, nonregenerative anemia, neutropenia, and hyperbilirubinemia were noted. Results of testing for feline immunodeficiency virus, feline leukemia virus, Toxoplasma gondii, and Mycoplasma sp. were negative. On cytologic examination of aspirates from the enlarged spleen and liver, a population of erythrophagocytic round cells was observed. Splenectomy and a liver biopsy were done which revealed a population of CD3+/CD79a- erythrophagocytic mononuclear round cells localized in the hepatic and splenic sinusoids. T-cell PARR (PCR for antigen receptor gene rearrangements) analysis of bone marrow and spleen demonstrated a single band indicative of a clonal proliferation of T cells. Based on the marked splenomegaly, sinusoidal infiltration, lack of lymphadenopathy, and results of cytology, PARR, and immunophenotyping, a diagnosis of low-grade extranodal T-cell lymphoma was made. The cat was treated with chlorambucil and prednisolone; clinical and laboratory abnormalities resolved and the cat has remained clinically normal for 2.5 years. To our knowledge, this report documents the first case of an erythrophagocytic T-cell lymphoma in a cat. The clinicopathologic findings were suggestive of hepatosplenic T-cell lymphoma, a neoplasm described previously only in humans and dogs.

Bacterial and Plant Enterotoxin B Subunit–Autoantigen Fusion Proteins Suppress Diabetes Insulitis

Several bacterial and plant enterotoxin B subunit-islet autoantigen fusion proteins were compared for their ability to serve as islet autoantigen carriers and adjuvants for reduction of pancreatic islet inflammation associated with type 1 diabetes. The cholera toxin B subunit (CTB), the heat-labile toxin B subunit from enterotoxigenic Escherichia coli (LTB), the Shigella toxin B subunit (STB), and the plant toxin ricin B subunit (RTB) were genetically linked to the islet autoantigens proinsulin (INS) and glutamic acid decarboxylase (GAD). The adjuvant-autoantigen gene fusions were transferred to a bacterial expression vector and the corresponding fusion proteins synthesized in E. coli. The purified adjuvant-autoantigen proteins were fed to 5-wk-old nonobese diabetic (NOD) mice once a week for 4 wk. Histological examination of pancreatic islets isolated from inoculated mice showed significant levels of insulitis reduction in comparison with uninoculated mice. The ratio of serum anti-INS and anti-GAD IgG2c to IgG1 antibody isotype titers increased in all ligand-autoantigen inoculated animal groups, suggesting an increase in effector Th2 lymphocytes in B subunit-mediated insulitis suppression. The results of these experiments indicate that bacterial and plant enterotoxin B subunit ligand-autoantigens enhance insulitis reduction in NOD mice. This research prompts further exploration of a multiadjuvant/autoantigen co-delivery strategy that may facilitate type 1 diabetes prevention and suppression in animals and humans.

Renal leiomyoma associated with Epstein-Barr virus in a pediatric transplant patient

Renal leiomyoma is a rare smooth muscle tumor of the kidney. An association between Epstein-Barr virus and smooth muscle tumors in immunocompromised patients recently has been recognized. We describe a pediatric renal transplant patient who developed an Epstein-Barr virus-associated renal leiomyoma in his transplant kidney 5 years posttransplantation. Possible factors involved in the tumor pathogenesis in our patient are discussed, including immunosuppression, growth hormone therapy, and Epstein-Barr virus induction.

Limited sampling strategy for cyclosporine (Neoral) area under the curve monitoring in pediatric kidney transplant recipients

Cyclosporine (CSA; Neoral) is one of the most common immunosuppressants used in pediatric renal transplantation. Research in adult renal transplant recipients has shown that 2-h post-dose concentration (C2) monitoring and limited sampling strategies (LSSs) are better at predicting drug exposure and outcome than trough concentrations (C0). While C0 monitoring is the usual practice in pediatric renal transplant patients, area under the curve (AUC) monitoring has been shown to be superior in terms of predictive ability and outcomes. However, AUC monitoring is impractical and inconvenient in a clinic setting because it involves many blood samples. An LSS provides a reliable alternative. The purpose of this study was to prospectively define an LSS (AUC(0-12)) for CSA monitoring and to test its predictive performance. As well, an LSS (AUC(0-4)) for CSA was developed and its predictive performance tested. Blood samples for CSA concentrations were collected in 29 stable pediatric renal transplant patients prior to (t = 0) and at 0.5, 1, 2, 4, 6, and 8 h following a steady-state morning CSA dose. AUC was calculated by the trapezoidal method; LSSs for AUC(0-12) and AUC(0-4) were determined using multiple regression analysis in 14 patients; and the LSSs' predictive performance was tested in 15 additional patients. Both LSSs require two blood samples. For the LSS (AUC(0-12)), blood samples are required immediately before the dose and 2 h post-dose: AUC(0-12) = 12.45 C0 + 2.17 C2 + 723.16 (r2 = 0.909). For the LSS (AUC(0-4)), blood samples are required at one and 2 h post-dose, AUC(0-4) = 1.17 C1 + 1.85 C2 - 41.00 (r2 = 0.971). The LSSs demonstrated low bias and high precision for both AUC(0-12) and AUC(0-4). Our two-concentration LSSs are accurate and precise predictors that are more clinically useful for our patient population than other LSSs that have been developed for pediatric renal transplant patients. Our study template provides a guide for other centers to develop accurate and precise LSSs specific to their own patient population.

Clinical validation for oxacillin susceptibility testing of coagulase negative staphylococci

Oxacillin susceptibility of coagulase negative staphylococci as assessed by conventional methods was confirmed by a modified Etest method, extended to detect heteroresistance. Verification of susceptibility was followed by successful treatment for six consecutive children with deep seated infections. Physicians' trust in such a validated method will contribute to the appropriate use of antibiotics.

Single-center experience with mycophenolate mofetil in pediatric renal transplant recipients

Mycophenolate mofetil (MMF), a potent and specific inhibitor of guanosine nucleotide synthesis, is a new immunosuppressive drug used to prevent rejection in transplant patients. Extensive data on its utility and efficacy exists in adult patients but there is limited experience in pediatrics. Twenty-four children (14 male, 10 female; 2-19 yr of age), eight of whom had received living-related donor (LRD) transplants and 16 of whom had received cadaveric donor (CD) transplants, have been treated with MMF in our institution since September 1996. MMF was administered for a duration ranging from 13 weeks to 38 months, at an average dose of 600 mg/m2 (range: 200-1,000 mg/dose) every 12 h, for a total experience of 304 patient months. MMF capsules were used in 16 patients and/or pediatric suspension in eight. Five patients were switched to MMF from azathioprine as a result of rejection episodes or inability to taper prednisone, between 5 weeks and 3.5 yr post-transplant. All patients received prednisone, cyclosporin A (CsA), and induction therapy with anti-lymphocyte globulin (19 patients), anti-thymocyte globulin (one patient) or daclizumab (four patients). In 12 patients started on MMF at the time of CD transplant, five (42%) had an acute rejection episode. In seven who received a LRD transplant, one (14%) had an acute rejection episode. No patients who were converted to MMF were treated for acute rejection following conversion to MMF. One LRD graft was lost at 19 days following injury to the donor artery at the time of retrieval. At the last follow-up, the average creatinine level was 93 micromol/L and average urea level was 8.6 mmol/L. One patient developed epigastric distress. Three patients developed diarrhea/abdominal pain requiring dose adjustment. Five episodes of leukopenia and one episode of thrombocytopenia required dose adjustment. Two patients developed symptomatic cytomegalovirus (CMV) infection, one while on acyclovir prophylaxis. No malignancy has been encountered to date. Hence, MMF can be administered safely to children with good effect and with an acceptable side-effect profile.

Towards the characterisation of heavy metals in dredged canal sediments and an appreciation of 'availability': two examples from the UK

Canal sediments can act as sinks for a wide range of contaminants including heavy metals from various sources (e.g. industrial and waste water discharges). Dredging of canals is required to maintain navigational depth and prevent flooding. The sediments removed from canals are often disposed of to land, being deposited either straight on to the banks of the canal or, in recent years, in licensed disposal sites. The aim of this work was to investigate the nature of dredged sediment-derived soils and the heavy metals present in them. Two disposal sites in the United Kingdom (UK) were investigated and soil samples taken. A variety of analytical techniques were used, including Aqua regia digestion and sequential extraction, in order to assess the concentrations and associations of metals present. Diethylene triaminepenta-acetic acid extracts, performed to illustrate plant-available metal concentrations, reveal that up to 40% of the total extracted metals were in an 'available' form. Variations in metal concentrations with depth in the soil cores show a significant correlation with total organic carbon content.

Vaginal vault suspension and enterocele repair by Richardson-Saye laparoscopic technique: description of training technique and results

OBJECTIVES

To describe the Richardson-Saye technique for laparoscopic vaginal vault suspension and enterocele repair (vaginal apex reconstruction) and the appropriate training needed for performance of this technique.

METHODS

Before using this technique, Drs Carter, Winter, and Mendelsohn first received training by observation of skilled surgeons performing the procedure, attending courses, and finally being tutored and proctored by Dr Saye on the appropriate performance of the technique. They then used this technique to surgically treat eight patients, 42 to 85 years of age, mean age 62 years, between March and September of 1999.

RESULTS

We included eight patients in this study who underwent the Saye-Richardson vaginal vault suspension and enterocele repair (apical vaginal vault reconstruction) by the suture technique. In all patients at six-month follow-up, the vaginal apex remains intact and well supported. We describe here the entire vaginal vault suspension and enterocele repair procedure with all its relevant details.

CONCLUSION

Laparoscopic reconstruction of the disrupted vaginal apex followed by reattachment to the previously broken uterosacral ligament with the use of permanent suture provides a secure and anatomically correct vault suspension. Before performing this technique, physicians should undergo proper training, including observation, courses, tutoring, and proctorship by a surgeon experienced in performing this technique.

Changes in the leachability of metals from dredged canal sediments during drying and oxidation

The behaviour of metals in canal sediments after their disposal to land has important implications for the environmental management of canal dredgings. The leaching behaviour of trace metals was investigated in a laboratory-based experiment using sediment from a canal in the UK (139 mg Zn kg-1dry sediment, 1.1 mg Cd, kg-1dry sediment 31.5 mg Cr kg-1dry sediment, 20.6 mg Cu kg-1dry sediment 48.4 mg Ni kg-1dry sediment, 43.4 mg Pb kg-1dry sediment and 7.6 mg As kg-1dry sediment). The sediment was allowed to dry. Cores (10 cm long) of the drying canal sediment were taken over a period of 12 weeks. A simple water extraction procedure was used to investigate changes in metal leachability at varying depths through the cores. Metal leachability increased over the first five weeks of drying and then subsequently decreased between weeks five and twelve, (e.g. Cd increased from approximately 0.006 to 0.018 mg/kgsediment then decreased to approximately 0.006 mg/kgsediment, Zn increased from approximately 1.5 to 3 mg/kgsediment and then decreased to approximately 1.5 mg/kgsediment). These results were combined with sulphide/sulphate ratios, which showed a decrease as the sediment dried (e.g. at 2-4 cm depth from approximately 1 to 0.49), and BCR sequential extraction data. Most metals (except Cd and As) showed a redistribution from the residual phase into more mobile phases as the sediment dried and oxidised. Metal leachability was strongly correlated with the sulphide/sulphate ratio with leachability normally increasing with decreasing sulphide/sulphate ratio. The combined results were used to infer the likely behaviour of dredged material upon disposal to land.

Enterocele repair and vaginal vault suspension

A paradigm shift has occurred in the approach to enterocele repair and vaginal vault suspension. This change in our approach is based on anatomic dissections that demonstrate that the loss of the upper suspensory fibers of the paracolpium and parametrium lead to uterine prolapse and vaginal prolapse after hysterectomy. In addition, the separation of the pubocervical from the rectovaginal fascia results in apical enterocele where the peritoneum is in contact with the vaginal mucosa. These fascial defects are hernias, and appropriate herniorraphy techniques will correct these defects and result in successful reconstruction of the vaginal tube and its reattachment to the suspensory cardinal uterosacral complex.

The adapter protein LAT enhances fcgamma receptor-mediated signal transduction in myeloid cells

FcgammaR clustering in monocytes initiates a cascade of signaling events that culminate in biological responses such as phagocytosis, production of inflammatory cytokines, and generation of reactive oxygen species. We have identified and determined the function of the adapter protein linker of activation of T cell (LAT) in FcgammaR-mediated signaling and function. Clustering of FcgammaRs on the human monocytic cell line, THP-1, induces phosphorylation of a major 36-kDa protein which immunoreacts with anti-LAT antisera. Our data indicate that although both the 36-kDa and 38-kDa isoforms of LAT are expressed in THP-1 and U937 human monocytic cells, FcgammaR clustering induces phosphorylation of the 36-kDa isoform only. Co-immunoprecipitation experiments revealed a constitutive association of p36 LAT with both FcgammaRI and FcgammaRIIa immunoprecipitates, and an activation-induced association of LAT with PLCgamma1, Grb2, and the p85 subunit of phosphatidylinositol 3-kinase. Transient transfection experiments in COS-7 cells indicated that overexpression of a wild type but not a dominant-negative LAT, that is incapable of binding to p85, enhances phagocytosis by FcgammaRI. Furthermore, bone marrow-derived macrophages from LAT-deficient mice displayed reduced phagocytic efficiency in comparison to the macrophages from wild-type mice. Thus, we conclude that p36 LAT serves to enhance FcgammaR-induced signal transduction in myeloid cells.

Investigation of anthropometric and work-rate profiles of elite South American international soccer players

BACKGROUND

The aim of the current investigation was to determine the movement profiles of elite South American soccer players during international competition and examine the relationship between anthropometric profile and work-rate variables.

METHODS

Seventeen full-time professional soccer players were filmed while competing for their countries. Anthropometric profiles were obtained for eleven of these players. Six full-time professional players from the English Premier League were also filmed for comparative purposes.

RESULTS

The South American international players covered significantly less (p<0.05) total distance during match-play than English Premier League players (International, 8638+/-1158 m; English Premier League, 10104+/-703 m). The total distance covered during the second half of the game was significantly reduced (p<0.05) compared to the first half distance for both groups of players (mean+/-SD first half 4605+/-625 m; mean+/-SD second half 4415+/-634 m). The data for both groups of players were combined to evaluate positional differences in the workrate profile. Midfield players covered a significantly greater (p<0.05) distance than forward players (midfield, 9826+/-1031 m; forwards, 7736+/-929 m) and defenders covered a greater (p<0.05) distance jogging backwards than forward players (defenders, 276+/-155 m; forwards, 68+/-25 m). Forwards sprinted a greater distance (p<0.05) than defensive players (defenders, 231+/-142 m; forwards, 557+/-142 m). Mean somatotype was a balanced mesomorph (2-5 1/2-2). Body mass and muscle mass was related to the total distance covered (r=0.43, r=0.53, p<0.05).

CONCLUSIONS

Based on these data, it seems that an individual's work-rate profile is dependent upon the type of competition and the playing position. Relationships between anthropometric profile and work-rate are complex due to the interaction between the variables that determine work-rate.

Carter-Thomason uterine suspension and positioning by ligament investment, fixation and truncation

OBJECTIVE

To describe a technique and results of uterine suspension and positioning by extraperitoneal ligament investment, fixation and truncation (UPLIFT).

STUDY DESIGN

Seventy-five women aged 19-48 years in a private referral center with chronic pelvic pain, dyspareunia and dysmenorrhea seeking treatment were evaluated and treated over a two-year period. Laparoscopic uterine suspension was performed using the Carter-Thomason 2-mm needle point suture passer. The instrument was passed within and along the round ligament. Thus, a pledget of round ligament and bridge of fascial tissue were created. Performing the uterine suspension procedure in this manner created shortened, thickened and strengthened ligaments that suspended the uterine fundus securely in a mildly anteverted position at the level of the exit point of the round ligaments through the inguinal canal.

RESULTS

The procedure was performed without complications in 75 patients over a two-year span. Each patient was evaluated for degree of retroversion and was assessed by ultrasound to identify any uterine or ovarian abnormalities. Pelvic pain and dyspareunia were reproduced by palpation of the retroverted uterus. The procedure took an average of 12 minutes to perform. All procedures were performed as outpatient procedures with same-day discharge, and there were no intraoperative complications. Delayed postoperative pain at the suspension site significant enough to require oral analgesia or injection with local anesthesia occurred in five patients (7%), four for one week and one for one month. For all 75 patients the pain with menses decreased from 8.4 to 1.7, with 0 being no pain and 10 being the worst pain the patient had ever experienced (P < .01, Wilcoxon's Signed Rank Test). Pain with intercourse decreased from 8.1 to 1.5 (P < .01, Wilcoxon's Signed Rank Test). Sixty-three patients (84%) reported essentially no pain (0-2), while 5 (7%) reported mild pain (2-5), 3 (4%) reported moderate pain (5-7), and 4 (5%) continued to have the pain that they had had before the surgery (8-10). For the 20 patients for whom a retroverted uterus was the only significant pathologic finding, 18 of these (90%) had immediate and sustained relief from their symptoms.

CONCLUSION

When dyspareunia, dysmenorrhea and pelvic pain are associated with a retroverted uterus, the uterus can be repositioned to a slightly anteverted position by UPLIFT with the Carter-Thomason needle point suture passer. Results with this anatomically correct technique are consistent with those previously given for other uterine suspension procedures. The advantages of this procedure are ease of performance, strengthening of the ligaments by shortening and the investment procedure, and a repair that maintains normal anatomic relationships.

Mutations in CUBN, encoding the intrinsic factor-vitamin B12 receptor, cubilin, cause hereditary megaloblastic anaemia 1

Megaloblastic anaemia 1 (MGA1, OMIM 261100) is a rare, autosomal recessive disorder characterized by juvenile megaloblastic anaemia, as well as neurological symptoms that may be the only manifestations. At the cellular level, MGA1 is characterized by selective intestinal vitamin B12 (B12, cobalamin) malabsorption. MGA1 occurs worldwide, but its prevalence is higher in several Middle Eastern countries and Norway, and highest in Finland (0.8/100,000). We previously mapped the MGA1 locus by linkage analysis in Finnish and Norwegian families to a 6-cM region on chromosome 10p12.1 (ref. 8). A functional candidate gene encoding the intrinsic factor (IF)-B12 receptor, cubilin, was recently cloned; the human homologue, CUBN, was mapped to the same region. We have now refined the MGA1 region by linkage disequilibrium (LD) mapping, fine-mapped CUBN and identified two independent disease-specific CUBN mutations in 17 Finnish MGA1 families. Our genetic and molecular data indicate that mutations in CUBN cause MGA1.

A systematic history for the patient with chronic pelvic pain

Chronic pelvic pain is a source of frustration to both the physician and the patient. Physicians have been ill equipped by their training to confront the multifaceted nature of the complaints of patients with chronic pelvic pain. Patients have experienced a repetitive dismissal of their complaints by physicians too busy in their practices to address their problems comprehensively. The approach to the patient with chronic pelvic pain must take into account six major sources of the origin of this pain: 1) gynecological, 2) psychological, 3) myofascial, 4) musculoskeletal, 5) urological, and 6) gastrointestinal. Only by addressing and evaluating each of these components by a very careful history and physical examination and by approaching the patient in a comprehensive manner can the source of the pain be determined and appropriate therapy be administered. This article was developed to provide the clinician with a set of tools and a methodology by which the patient with this complaint can be approached.

Occult anal sphincter trauma following randomized forceps and vacuum delivery

OBJECTIVE

To determine the prevalence of occult anal sphincter trauma 5 years after randomization to forceps and vacuum delivery.

METHOD

Anal endosonography and manometry was performed in 44 of 313 women who had originally participated in one center of the Keele University Multicenter Assisted Delivery Trial at the North Staffordshire Maternity Hospital between September 1989 and May 1990.

RESULTS

50% admitted to defecatory symptoms and anal sphincter defects were identified in 61%. On the basis of intention to treat, 82% of forceps (n = 17) and 48% of vacuum deliveries (n = 27) had occult sphincter defects (P = 0.03). In four women, both instruments were used. However, the preponderance of defects in the forceps group persisted even when analysis was performed according to the final mode of delivery as well as in the group where only one instrument was used (n = 40). There was a significant fall in maximum squeeze anal pressure in the forceps group compared to the vacuum group (56 vs. 36 mmHg; P = 0.0007). Although twice as many in the forceps group suffered anal incontinence (32% vs. 16%) significance was not reached.

CONCLUSIONS

Vacuum delivery appears to be associated with less occult anal sphincter trauma than forceps delivery. A large prospective randomized study is required to address the impact of specific situations, such as failed instrumentation with use of a second instrument and rotational delivery.

Sexual dimorphism in the physiques of World Championship divers

The aim of this study was to evaluate sexual dimorphism in male (n = 43) and female (n = 39) springboard and platform divers at the 1991 World Diving Championships in Perth, Western Australia. In addition to recording the age, height and body mass of each diver, measurements were taken of 8 skinfolds, 13 girths, 8 breadths and depths, and 11 lengths. The derived variables were somatotype, sum of 6 skinfolds (SUM6) and height-adjusted proportional z-scores. The mean (+/- s) values for the males were: age, 22.2 +/- 4.6 years; height, 171 +/- 9 cm; body mass, 66.7 +/- 10.2 kg; somatotype, 2.0-5.3-2.4 +/- 0.5-1.0-0.8; SUM6, 45.9 +/- 11.4 mm. For the females, these values were: age, 20.9 +/- 3.8 years; height, 161 +/- 6 cm; body mass, 53.7 +/- 5.5 kg; somatotype, 2.8-3.8-2.8 +/- 0.7-1.0-0.9; SUM6, 65.6 +/- 17.0 mm. The males were taller, heavier, more mesomorphic, less endomorphic and had a smaller SUM6 than the females (P < 0.01). A series of discriminant function analyses were applied to groups of variables. Wilks' lambda and the overall F-ratio were highly significant (P < 0.001), with correct classification of sex reaching 84-99%. The best combinations of variables were as follows: (1) absolute size, 3 girths + SUM6, or body mass + SUM6 + height (Wilks' lambda = 0.17-0.35); (2) relative size, 2 girths + SUM6 + body mass. Combinations of breadths and lengths, skinfolds, or somatotype components, were less successful, with 84-87% classified correctly (Wilks' lambda = 0.40-0.48). We conclude that, in addition to the expected absolute size differences, sexual dimorphism between male and female divers can be explained by differences in relative size, skinfolds and somatotype, and that these differences may have implications for coaching and selection in diving.