Abstract P4-03-13: Obesity and breast cancer: The adipocyte-macrophage interaction as a mediator of metastasis

Obese individuals with breast cancer have a poorer prognosis and higher risk of metastatic disease vs. non-obese patients. Prior research has largely focused on defining the interactions between adipocytes and tumor cells, but other cell types may also play a role. Adipose tissue in obese individuals is characterized by a significant infiltration of macrophages. We have therefore investigated the adipocyte-macrophage interaction as a possible mechanism whereby obesity promotes breast cancer metastasis.

We performed co-culture with both human and murine cells to determine whether adipocytes influence the expression of metastasis-promoting signals in macrophages. For the human system we co-cultured primary breast adipocytes with THP-1 macrophages. For the murine system we co-cultured 3T3-L1 differentiated adipocytes with J774.1 macrophages. We then assayed the mRNA levels and protein expression of metastasis-promoting genes.

In both systems we found that co-culture with adipocytes increased the expression of Vascular Endothelial Growth Factor A (VEGF-A) in macrophages. In examining a potential mechanism, we also show that media collected from cultured adipocytes (adipocyte-conditioned media) activates the transcription factor Egr-1 in macrophages. Since Egr-1 is a known regulator of VEGF-A expression, this is a potential mechanism whereby VEGF-A transcription is up-regulated. Treatment of human macrophages with Interleukin-6, Leptin and Insulin induced VEGF-A levels to a similar degree as co-culture, identifying these as adipocyte-derived signals that can possibly mediate this effect.

In summary we have found that the interaction between adipocytes and macrophages leads to the up-regulation of the pro-angiogenic signal VEGF-A in macrophages. Therefore this represents a potential mechanism whereby obesity could promote breast cancer metastasis.

Citation Format: Connelly L, Yadav N, Barcikowski A, Imaizumi Y, Jacobs A. Obesity and breast cancer: The adipocyte-macrophage interaction as a mediator of metastasis [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-03-13.

The life and times of Ethel Mary Doidge, a pioneer of South African mycology

The South African National Collection of Fungi was established in 1905 and celebrated its 110th anniversary in 2015. The diverse history of the collection is marked by the name of Ethel Mary Doidge as she has been a companion of mycology in South Africa.

Converting sunlight into audible sound by means of the photoacoustic effect: The Heliophone

One hundred and thirty-five years after Alexander Graham Bell and his assistant Charles Sumner Tainter explored the photoacoustic effect, and about 40 years after Rosencwaig and Gersho modeled the effect in a photoacoustic cell configuration, the phenomenon is revisited in a "Heliophone" device that converts sunlight into sound. The light is focused on a carbon blackened copper coated Kapton foil in an acoustic cell by means of a compound parabolic collimator, and its intensity is modulated by a mechanical chopper. A horn is employed to make the sound audible without electronic amplification. The description of the photoacoustic effect that was introduced by Rosencwaig and Gersho is extended to a cell-horn configuration, in which the periodically heated air above the foil acts as an oscillating piston, driving acoustic waves in the horn. The pressure in the cavity-horn assembly is calculated by considering the air layer piston as an equivalent volume velocity source. The importance of the carbon black (soot) layer to enhance light absorption, but above all to enhance the photothermal excitation efficiency, is elucidated by means of an experimentally supported physical model.

Catch-up validation study of an in vitro skin irritation test method based on an open source reconstructed epidermis (phase I)

We have developed a new in vitro skin irritation test based on an open source reconstructed epidermis (OS-REp) with openly accessible protocols for tissue production and test performance. Due to structural, mechanistic and procedural similarity, a blinded catch-up validation study for skin irritation according to OECD Performance Standards (PS) was conducted in three laboratories to promote regulatory acceptance, with OS-REp models produced at a single production site only. While overall sensitivity and predictive capacity met the PS requirements, overall specificity was only 57%. A thorough analysis of the test results led to the assumption that some of the false-positive classifications could have been evoked by volatile skin-irritating chemicals tested in the same culture plate as the non-irritants falsely predicted as irritants. With GC/MS and biological approaches the cross-contamination effect was confirmed and the experimental set-up adapted accordingly. Retesting of the affected chemicals with the improved experimental set-up and otherwise identical protocol resulted in correct classifications as non-irritants. Taking these re-test results into account, 93% overall sensitivity, 70% specificity and 82% accuracy was achieved, which is in accordance with the OECD PS. A sufficient reliability of the method was indicated by a within-laboratory-reproducibility of 85-95% and a between-laboratory-reproducibility of 90%.

Reactivation of mutant p53 by a dietary-related compound phenethyl isothiocyanate inhibits tumor growth

Mutations in the p53 tumor-suppressor gene are prevalent in human cancers. The majority of p53 mutations are missense, which can be classified into contact mutations (that directly disrupts the DNA-binding activity of p53) and structural mutations (that disrupts the conformation of p53). Both of the mutations can disable the normal wild-type (WT) p53 activities. Nevertheless, it has been amply documented that small molecules can rescue activity from mutant p53 by restoring WT tumor-suppressive functions. These compounds hold promise for cancer therapy and have now entered clinical trials. In this study, we show that cruciferous-vegetable-derived phenethyl isothiocyanate (PEITC) can reactivate p53 mutant under in vitro and in vivo conditions, revealing a new mechanism of action for a dietary-related compound. PEITC exhibits growth-inhibitory activity in cells expressing p53 mutants with preferential activity toward p53^R175, one of the most frequent ‘hotspot' mutations within the p53 sequence. Mechanistic studies revealed that PEITC induces apoptosis in a p53^R175 mutant-dependent manner by restoring p53 WT conformation and transactivation functions. Accordingly, in PEITC-treated cells the reactivated p53^R175 mutant induces apoptosis by activating canonical WT p53 targets, inducing a delay in S and G2/M phase, and by phosphorylating ATM/CHK2. Interestingly, the growth-inhibitory effects of PEITC depend on the redox state of the cell. Further, PEITC treatments render the p53^R175 mutant sensitive to degradation by the proteasome and autophagy in a concentration-dependent manner. PEITC-induced reactivation of p53^R175 and its subsequent sensitivity to the degradation pathways likely contribute to its anticancer activities. We further show that dietary supplementation of PEITC is able to reactivate WT activity in vivo as well, inhibiting tumor growth in xenograft mouse model. These findings provide the first example of mutant p53 reactivation by a dietary compound and have important implications for cancer prevention and therapy.

[Supporting patients in self-management: moving to a personalised approach]

OBJECTIVE

The aim of this research was to assess the effect of providing personalised self-management support on patient activation (knowledge, skills, self-efficacy) and self-management behaviour.

DESIGN

Cluster randomised trial in 15 general practices (Dutch Trial Register No.: NTR 3960).

METHOD

Patients aged 18 years or older with a chronic condition were invited to participate in the study. The Self-Management Screening (SeMaS) questionnaire - which illustrates barriers to self-management - was used as a tool for personalised self-management support. Nurse practitioners in the intervention practices were trained for 2 hours in using SeMaS and personalising self-management support on the basis of the SeMaS profile. At baseline and after 6 months, patients filled in questionnaires on patient activation (PAM-13) and lifestyle. Using data from the questionnaires and medical records, the use of individual care plans, referrals to self-management interventions, self-monitoring and healthcare use were assessed. We used a multiple multilevel regression model for data analysis.

RESULTS

After 6 months, no difference was found in patient activation between the control group (n = 348) and the intervention group (n = 296). 29.4% of the patients in the intervention group performed self-monitoring, versus 15.2% in the control group (regression coefficient r = 0.9, p = 0.01). In the per-protocol analysis (control n = 348; intervention n = 136), the number of individual care plans (r = 1.3, p = 0.04) and the number of patients performing self-monitoring (r = 1.0; p = 0.01) were higher in the intervention group.

CONCLUSION

Personalised self-management support with the use of the SeMaS method stimulates self-monitoring and the use of individual care plans. The intervention had no effect on patient activation or lifestyle. Given the positive secondary outcomes, the further potential of the tool should be researched.

A novel octavalent combined Erysipelas, Parvo and Leptospira vaccine provides (cross) protection against infection following challenge of pigs with 9 different Leptospira interrogans serovars

Background

In the present study the efficacy and cross protection of a novel ready-to-use combination vaccine, Porcilis® Ery + Parvo + Lepto, against swine leptospirosis, was investigated. The octavalent vaccine contains inactivated antigens of Erysipelothrix rhusiopathiae, Parvovirus and 6 Leptospira interrogans sensu lato strains of serogroups Canicola, Icterohaemorrhagiae, Grippotyphosa, Australis (Bratislava), Pomona and Tarassovi. In this study ninety pigs were vaccinated twice with Porcilis® Ery + Parvo + Lepto at six and ten weeks of age and ninety age and source-matched animals served as unvaccinated control. Two weeks after booster vaccination, groups of vaccinated and control pigs (ten pigs per group) were challenged with fresh virulent cultures of either of the nine different challenge strains. Compared to the vaccine strains the challenge strains were heterologous strains of the same serovar or of a different serovar within the same serogroup. The challenge strains tested were of serovar Canicola, Icterohaemorrhagiae, Copenhageni (serogroup Icterohaemorrhagiae), Grippotyphosa, Bananal/Liangguan (serogroup Grippotyphosa), Pomona, Tarassovi and Vughia (serogroup Tarassovi).

Results

After the different challenges most control animals became leptospiraemic for 2–7 days. The vaccinated pigs remained blood culture negative except for two animals after serovar Icterohaemorrhagiae and two animals after serovar Tarassovi challenge which became leptospiraemic for only 1 day. The incidence of Leptospiraemia (as determined by blood culture) was significantly less in vaccinates compared to the controls after all challenges. The vaccine also prevented renal infection and urinary shedding after serovar Canicola challenge. The other serovars did not induce detectable renal infection or urinary shedding.

Conclusion

The present study demonstrates that the new combination vaccine Porcilis® Ery + Parvo + Lepto induces significant (cross) protection against nine different serovars within the serogroups Canicola, Icterohaemorrhagiae, Grippotyphosa, Australis (Bratislava), Pomona and Tarassovi.

Comparison of measured and estimated maximum skin doses during CT fluoroscopy lung biopsies

PURPOSE

To measure patient-specific maximum skin dose (MSD) associated with CT fluoroscopy (CTF) lung biopsies and to compare measured MSD with the MSD estimated from phantom measurements, as well as with the CTDIvol of patient examinations.

METHODS

Data from 50 patients with lung lesions who underwent a CT fluoroscopy-guided biopsy were collected. The CT protocol consisted of a low-kilovoltage (80 kV) protocol used in combination with an algorithm for dose reduction to the radiology staff during the interventional procedure, HandCare (HC). MSD was assessed during each intervention using EBT2 gafchromic films positioned on patient skin. Lesion size, position, total fluoroscopy time, and patient-effective diameter were registered for each patient. Dose rates were also estimated at the surface of a normal-size anthropomorphic thorax phantom using a 10 cm pencil ionization chamber placed at every 30°, for a full rotation, with and without HC. Measured MSD was compared with MSD values estimated from the phantom measurements and with the cumulative CTDIvol of the procedure.

RESULTS

The median measured MSD was 141 mGy (range 38-410 mGy) while the median cumulative CTDIvol was 72 mGy (range 24-262 mGy). The ratio between the MSD estimated from phantom measurements and the measured MSD was 0.87 (range 0.12-4.1) on average. In 72% of cases the estimated MSD underestimated the measured MSD, while in 28% of the cases it overestimated it. The same trend was observed for the ratio of cumulative CTDIvol and measured MSD. No trend was observed as a function of patient size.

CONCLUSIONS

On average, estimated MSD from dose rate measurements on phantom as well as from CTDIvol of patient examinations underestimates the measured value of MSD. This can be attributed to deviations of the patient's body habitus from the standard phantom size and to patient positioning in the gantry during the procedure.

Fusarium species isolated from Pennisetum clandestinum collected during outbreaks of kikuyu poisoning in cattle in South Africa

Kikuyu poisoning occurs sporadically in South Africa. It is of major economic importance, as valuable dairy cows are often poisoned by it, and once affected, the mortality rate is high. Pennisetum clandestinum samples were collected during eight outbreaks of kikuyu poisoning in cattle in the Eastern Cape Province of South Africa from 2008 to 2010. The kikuyu grass samples were submitted specifically for the isolation and molecular identification of Fusarium species, as it was recently suggested that mycotoxins synthesised by Fusarium torulosum could be the cause of this intoxication. Ninety-four Fusarium isolates were retrieved from the grass samples, of which 72 were members of the Fusarium incarnatum/Fusarium equiseti species complex based on morphology and phylogenetic analyses of the translation elongation factor 1α sequence data. The South African isolates from kikuyu identified as members of the F. incarnatum/F. equiseti species complex grouped together in six separate clades. The other isolates were Fusarium culmorum (n = 3), Fusarium redolens (n = 4) and Fusarium oxysporum (n = 15). Although F. torulosum could not be isolated from P. clandestinum collected during kikuyu poisoning outbreaks in South Africa, the mycotoxicosis theory is still highly plausible.