P4-07-12: Identification of p53 Mutation in Whole Genome DNA from Single Circulating Tumor Cells (CTCs) and Primary Breast Cancers (BC) from Patients (pts) with Metastatic Breast Cancer (MBC)

Background: CTCs represent the source of distant metastases, and are also implied in the growth/re-growth of primary BC. Molecular/gene-level characterization of similarities and discordances between CTCs and BCs in pts with MBC may provide useful information for individualized treatment. Since somatic p53 mutations are frequently observed in primary BCs, we set out to assess the feasibility of identifying such mutations in CTCs from pts with MBCs, and compare the findings with those of the primary BCs from the same pts. Material and Method: Fiber-optic Array Scanning Technology (FAST) was used for identification and location of CTCs on large glass substrates. CTCs were identified after blood samples (10 ml) from MBC pts were stained to detect CTCs via automated digital microscopy by morphology, based on immunofuorescence staining for cytokeratin and nucleus, and the absence of CD45. Single CTCs from 10 pts with MBC were identified and removed from the glass substrates. DNA was extracted, and the whole genome of isolated CTCs was amplified by using whole genome amplification method (Sigma). P53 mutations in exon 5, exon 6, exon 7 and exon 8 were assessed. As comparison, genomic DNA from formalin-fixed and paraffin-embedded (FFPE) from primary BCs of the same pts, was amplified using the same method.

Results: p53 mutations were found in 8 out of 10 CTCs, and in 4 out of 10 in primary BC samples. Of 8 mutations detected in CTCs, one silent mutation and 7 missense mutations were seen. One particular point mutation, R181L, previously assessed as functional mutation, was observed in 4 out of 8 CTCs. None of the 4 mutations (a silent mutation, one missense mutation and two different deletions) detected in tumor samples were found in CTCs. We validated that the mutations detected in CTCs were not artifacts occurring during genome amplification, by comparing p53 mutations between unamplified tumor genomic DNA vs. amplified samples.

Conclusion: Whole genome amplification based on extracting DNA from single CTCs using FAST, and identification of mutations such as those in p53, is feasible. The quantitative and qualitative discordance in detecting p53 mutations between CTCs and primary BCs may be due to CTCs acquiring new -possibly epithelial-mesenchymal transition-like-characteristics with metastatic potential as they evolve from the primary tumors or metastatic sites, or, technical issues (analyzing FFPE-preserved vs. CTCs, tumor heterogeneity) may contribute to our findings. Further assessment of the functionality of high frequent functional mutations such as R181L is warranted.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-12.

Multiple Biomarker Expression in Circulating Tumor Cells (CTCs) from Metastatic Breast Cancer (MBC) Patients (Pts)

Background: Numeration of CTCs from MBC pts is predictive of outcome. Quantitative changes in CTC-s are currently tested for their potential to monitor therapy (Rx). Biomarker characterization of CTCs may be a useful adjunctive guide for Rx selection. Method: At the COHCC between 5/1/2008 and 4/31/09, consecutively treated pts with newly diagnosed/or progressing MBC were accrued. Blood samples (10-40 ml) were procured prior to or during systemic Rx, and were sent to PARC for analysis. A novel high-speed scanning instrument located CTCs from cytokeratin (CK) labeling enabling high resolution images to be selectively acquired using digital microscopy. From these images, CTCs were identified by CK, DAPI (nuclear marker) and CD45, and protein expression levels were determined for HER2, ER, ERCC1 and EGFR. Cell lines with expression of each marker were used for normalization of the cell intensities, and a scoring system was used to account for relative number and expression levels of markers on the CTCs. Results: Of 21pts tested 81% were found to have detectable CTCs. CTCs were further analyzed from 13 such pts, some of whom had multiple specimens. Expression of EGFR and ERCC1 were detected in 77% and 92% of specimens tested. Expression of HER2 was detected in 47% and ER in 91% in samples tested. Discordance rates for the expression of the above 4 markers on the primary tumors vs. CTC were measured either before, during systemic treatment, or at progression on therapy. We observed significant discordance rates for all markers tested:ER 36%; ERCC1:20%; EGFR:60%; and HER2: 50%, respectively. Conclusions: Multiplex tumor marker testing of CTCs from pts with MBC is feasible. Following additional validation of expression patterns and the high discordance rates observed between CTCs and primary or metastatic tumor sites, prospective trials incorporating CTC expression into personalized treatment strategies may be justified.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3007.

Observations of beam losses due to bound-free pair production in a heavy-ion collider

We report the first observations of beam losses due to bound-free pair production at the interaction point of a heavy-ion collider. This process is expected to be a major luminosity limit for the CERN Large Hadron Collider when it operates with (208)Pb(82+) ions because the localized energy deposition by the lost ions may quench superconducting magnet coils. Measurements were performed at the BNL Relativistic Heavy Ion Collider (RHIC) during operation with 100 GeV/nucleon (63)Cu(29+) ions. At RHIC, the rate, energy and magnetic field are low enough so that magnet quenching is not an issue. The hadronic showers produced when the single-electron ions struck the RHIC beam pipe were observed using an array of photodiodes. The measurement confirms the order of magnitude of the theoretical cross section previously calculated by others.

Detecting circulating tumor cells in metastatic breast cancer patients using fiber-optic array scanning technology

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Background: Circulating tumor cell (CTC) detection and enumeration has been shown to be a valuable tool for determining prognosis in metastatic breast cancer patients. CTCs are rare, existing in the circulation at estimated concentrations of 1 in 1 - 10 million normal blood cells. To date, the most widely used technique to detect CTCs has used immunomagnetic enrichment based protocols. In this validation study, we sought to determine if an enrichment free approach using an immunofluorescent cell attachment protocol along with fiber-optic array scanning technology (FAST) could achieve similar results. Methods: We have developed and validated a scanning instrument using FAST that can be used in conjunction with an immunofluorescence staining protocol to efficiently detect CTCs. The protocol uses a pan anti-cytokeratin antibody cocktail directed against 9 cytokeratins along with a DAPI nuclear counterstain. FAST defines cell positions, so relocation and retrospective analysis of CTCs is possible. Using this system, we assayed 50 blood specimens obtained from metastatic breast cancer patients. Pathologic review of CTCs was performed identifying CTCs as cytokeratin positive and DAPI positive. Survival analyses were determined using Kaplan-Meier analyses. Results: 31 women with metastatic breast cancer were enrolled in the study and provided 50 peripheral blood specimens. The median CTC count for patients with progressive disease was 8.5, while the median CTC count for patients with stable or responding disease was 1. At a median follow-up of 1 year, 11 patients had died. Patients with =5 CTCs had a median survival of 212 days, while the median survival for patients with 0–4 CTCs had not been reached after 1 year (p=0.0012). Patients with progressive disease had significantly higher CTC counts (p<0.0001) than those who were stable or responding to therapy. Conclusions: This study confirms the previously reported efficacy of CTC enumeration in determining the prognosis of metastatic breast cancer patients and establishes the potential utility of the FAST cytometer as a method for CTC enumeration.

No significant financial relationships to disclose.

Life history of a small form of the plethodontid salamander Desmognathus quadramaculatus

Abstract

We sampled Desmognathus quadramaculatus, one of the largest species of plethodontid salamanders in eastern North America, from a population exhibiting extremely small adult body sizes in the Bald Mountains of North Carolina (USA). In order to test the hypothesis that miniaturization in desmognathine salamanders is due to early metamorphosis and maturation, we estimated ages and sizes at metamorphosis and maturation. Analysis of size-frequency distributions suggests that most larvae metamorphose after 24 months, with the remainder metamorphosing after 36. The minimum age of sexually mature individuals in the summer months is estimated to be 4 years in males and 5 years in females; some may mature 1 year earlier. This is earlier than other reliable estimates of age at maturation in D. quadramaculatus, and appears to account for the small size of the species at this locality. Larval and juvenile growth rates are within the range of growth rates of other populations. As in other populations of D. quadramaculatus, males are smaller than females at maturation, but grow to larger sizes. Estimates of clutch sizes based on dissection of gravid females are relatively low. The other species of salamanders in this community do not appear to be miniaturized.

Cytokine and adhesion molecule expression in primary human endothelial cells stimulated with fever-range hyperthermia

Migration of blood-borne lymphocytes into lymphoid tissues and sites of inflammation is initiated by vascular adhesion molecules and proinflammatory cytokines. Previous in vivo studies have shown that febrile temperatures dynamically stimulate adhesion in differentiated high endothelial venules (HEV), which are portals for lymphocyte extravasation. This report examines the direct effect of fever-range hyperthermia on the expression of adhesion molecules and cytokines by primary cultured endothelial cells. In both macrovascular (HUVEC) and microvascular (HMVEC) endothelial cells, fever-range hyperthermia (40 degrees C for 6-12 h) did not affect expression of adhesion molecules (ICAM-1, E-selectin, VCAM-1, P-selectin, PECAM-1, PNAd, MAdCAM-1), cytokine release (IL-1beta, TNF-alpha, IFN-gamma, IL-6, IL-11, IL-12, IL-13), or chemokine secretion (IL-8, RANTES, MCP-1, MIP-1beta, MIG). This is in contrast to the stimulatory effects of TNF-alpha or 43 degrees C heat shock. However, a novel role for fever-range hyperthermia was identified in augmenting actin polymerization in cultured endothelial cells and enhancing the ability of endothelial-derived factors to transactivate the alpha4beta7 integrin lymphocyte homing receptor. These findings provide insight into the tightly regulated effects of fever-range hyperthermia that exclude induction of adhesion in non-activated endothelium of normal blood vessels. Through these mechanisms, it is proposed that febrile temperatures associated with infection or clinical hyperthermia avoid the unproductive exodus of lymphocytes to non-involved extralymphoid tissues while simultaneously promoting lymphocyte delivery to sites of immune activation.

CT-integrated robot for interventional procedures: preliminary experiment and computer-human interfaces

Pre-operative planning and intra-operative computer interfaces for minimally invasive interventions were investigated with an active robot integrated with a CT scanner. To test the robotic system, a biopsy study was performed using a pig. For pre-operative planning, a virtual needle was superimposed on axial slices and multiplanar reformatted views in correlation with the interventional field. The path of the virtual needle was sent to the robot's controller, and the robot's needle gripper moved into a position congruent with the planned path. Intra-operative controls were then used to drive the needle while keeping the interventionalist's hands out of the direct X-ray beam during CT fluoroscopy. After needle insertion, the imaged and virtual needles were shown to be sufficiently congruent.

Lispro insulin as premeal therapy in type 1 diabetes: comparison with Humulin R

AIMS

To determine the efficacy, tolerability and safety of the short-acting insulin analogue lispro compared with regular short-acting insulin, Humulin R as premeal therapy in type 1 diabetes mellitus and to assess the safety of lispro administered for one year.

METHODS

The study was part of an international multicentre crossover study (IOAG) in which 1008 patients were randomised. Twenty patients from Auckland, with insulin dependent diabetes mellitus, received lispro for 3 months and Humulin R for 3 months in a crossover design. At the end of the crossover period, 19 patients elected to participate in an open label continuation of lispro therapy. Humulin N, L or U was used as basal insulin therapy.

RESULTS

Lispro and Humulin R in combination with Humulin N, L or U did not significantly differ with respect to glycaemic control or incidence of hypoglycaemia. Glycosylated haemoglobin (HbA1C) improved from 8.6% at baseline to 7.6 +/- 0.9 (Humulin R) and 7.7 +/- 1.1% (lispro). During the open label continuation of lispro plus the usual basal insulin HbA1C deteriorated to 8.6% after 12 months.

CONCLUSIONS

In this short-term comparison, lispro and Humulin R were well tolerated, while glycaemic control, incidence of hypoglycaemia and adverse effects were similar.

Lipid and carbohydrate metabolic risk markers for coronary heart disease and blood pressure in healthy non-obese premenopausal women of different racial origins in the United Kingdom

Metabolic risk markers for coronary heart disease (CHD) were determined in apparently healthy females of differing racial origins residing in the United Kingdom. The females were of black (n=122), Oriental (n=144), South Asian (n=128), and white (n=271) origin, premenopausal, non-obese, and aged 16-45 years. In comparison to whites, South Asians had lower serum high-density lipoprotein (HDL) cholesterol and HDL2 cholesterol and higher fasting and oral glucose tolerance test plasma insulin responses. Black females had higher fasting plasma and oral glucose tolerance test insulin and lower serum triglyceride and glucose compared with white females. Orientals differed from whites in having higher fasting and oral glucose tolerance test insulin concentrations. Resting systolic or diastolic blood pressures, total serum cholesterol, HDL3 cholesterol, and low-density lipoprotein (LDL) cholesterol did not differ between groups. Whereas previous studies have demonstrated similar differences in representative samples from different ethnic communities, our results clearly demonstrate that differences also exist in young healthy females, individuals considered to have the least risk of CHD.

Associations between insulin sensitivity, and free fatty acid and triglyceride metabolism independent of uncomplicated obesity

Insulin resistance is associated with hypertriglyceridemia and elevated free fatty acid (FFA) concentrations in obese and diabetic individuals, but it is unclear to what extent this relationship is independent of obesity and is present in healthy individuals. We studied 92 healthy middle-aged males selected from the top, middle, and lowest quintiles of the insulin sensitivity index (Si) determined in a group of 182 men using the minimal model of glucose disappearance. Plasma FFA, triglyceride, glucose, insulin, and C-peptide concentrations were measured during a 3-hour intravenous glucose tolerance test (IVGTT). The low-Si (most insulin-resistant) group had more central body fat distribution (subscapular/triceps skinfold thickness) and a higher median body mass index (BMI) of 26.8 (range, 21.1 to 41.1) kg.m-2 compared with the middle- and high-Si groups with BMIs of 24.9 (19.1 to 31.5) and 23.7 (18.8 to 33.2) kg.m-2 (P < .05). Relatively minor glucose intolerance in the low-Si group was no longer significant when central adiposity was accounted for. Glucose tolerance was maintained by increased insulin secretion, leading to IVGTT insulin responses twofold and fourfold higher in the middle- and low-Si groups, respectively, compared with the high-Si group (P < .01). Fasting FFA and triglyceride concentrations were increased in the low-Si group relative to the other groups independent of BMI or central adiposity (P < .01). During the IVGTT, FFA decreased to similar minimum concentrations in all three groups. Triglyceride concentrations during the IVGTT increased above their minimum levels, particularly in the low-Si group (P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Glomerular hyperfiltration in young Polynesians with type 2 diabetes

An increase in glomerular filtration rate (hyperfiltration) may be an important early event in the initiation of diabetic nephropathy but the prevalence of hyperfiltration appears to vary between different populations with type 2 diabetes. We have measured glomerular filtration rate using 51Cr EDTA clearance in 15 young Polynesians (mean age 32 years), 1-30 months after the initial diagnosis of type 2 diabetes and 15 control Polynesian subjects of comparable age and sex distribution. The mean glomerular filtration rate in the diabetic subjects (216 ml/min) was 57% greater than that of the controls (137.5 ml/min, P < 0.0001). About one-third of their excess in glomerular filtration rate could be accounted for by the marked obesity of the diabetic subjects, but even after correcting for body size the diabetic subjects still had a significantly higher mean glomerular filtration rate than controls (165.6 vs. 119.6 ml/min per 1.73 m2, P < 0.001); 73% of the diabetic subjects had hyperfiltration (> 140 ml/min per 1.73 m2). The diabetic subjects were normotensive but nonetheless had increased rates of albumin excretion (median 61 versus 9 mg/day, P < 0.001). We conclude that hyperfiltration is common in young Polynesians with recently diagnosed type 2 diabetes. Prospective studies are needed to determine whether this early abnormality of renal function heralds the later development of overt nephropathy.

Rates of progression to end stage renal failure in nephropathy secondary to type 1 and type 2 diabetes mellitus

BACKGROUND

Diabetic nephropathy is now the commonest single cause of end-stage renal failure (ESRF) in New Zealand.

AIMS

To investigate differences in the natural history of established nephropathy in Type 1 and 2 diabetes.

METHODS

Retrospective analysis of the rate of progression to ESRF in 17 subjects with Type 1 diabetes (predominantly European) compared to 29 subjects with Type 2 diabetes (all Polynesian). The rate of decline of renal function was determined from serial creatinine measurements (median 5, range 3-8) during progression of chronic renal failure to end stage. Glomerular filtration rate (GFR) was estimated from creatinine measurements using the Cockcroft Gault equation, and the regression slope of these measurements against time was used to determine rate of change of renal function.

RESULTS

GFR fell significantly more rapidly in the group with Type 2 diabetes than in those with Type 1 diabetes: median 1.7 (interquartile range 1.2 to 2.3) mL min-1 month-1 vs 1.1 (interquartile range 0.4 to 1.5) mL min-1 month-1, p = 0.017. During the study period the mean reduction in diastolic blood pressure in subjects with Type 1 diabetes (15 mmHg) was greater than that in the Type 2 subjects (8 mmHg), but the stage at which antihypertensives were commenced was similar in the two groups. Glycaemic control was worse in the subjects with Type 1 diabetes (p < 0.005). The differences in blood pressure control were not significant on analysis of covariance which indicated that ethnicity was the major determinant of the different rates of decline of GFR between the groups. We conclude that in subjects with diabetic nephropathy the rate of progression to ESRF is more rapid in Polynesians with Type 2 diabetes than in Europeans with Type 1 diabetes. This could contribute to the apparent excess of Type 2 diabetic subjects of Polynesian origin on renal replacement programmes in New Zealand.

Genetic variation associated with differences in the response of plasma apolipoprotein B levels to dietary fibre

1. We hypothesized that differences within genes whose protein products are involved in apolipoprotein B metabolism could influence the response of plasma apolipoprotein B-containing lipoprotein concentrations to increases in dietary fibre. 2. We studied 67 subjects (43 men and 24 women) who had taken part in parallel 2 week metabolic dietary studies involving either wheat bran or oat bran supplementation. Fasting blood lipid, lipoprotein and apolipoprotein concentrations were measured at the start and end of the 2 week metabolic period. Genotypes were determined using DNA markers for the low-density lipoprotein receptor, apolipoprotein B, apolipoprotein CIII and hepatic lipase gene loci. 3. Reductions in plasma concentrations of apolipoprotein B were significantly different depending on genotype determined with a low-density lipoprotein receptor DNA marker (P = 0.03). There was no significant variation in the reduction of plasma total cholesterol, low-density lipoprotein cholesterol or apolipoprotein B concentrations for alleles of other genes tested. 4. Thus, genetic variability is associated with interindividual differences in the fibre-related reduction in plasma apolipoprotein B and apolipoprotein B-containing lipoprotein concentrations. Implementation of current dietary recommendations to reduce plasma lipoprotein levels with fibre may have variable effects in different individuals in part because of structural differences in candidate genes whose products are involved in lipoprotein metabolism.

Effect of simvastatin on high density lipoprotein subfractions and apolipoproteins in type IIa hypercholesterolemia

Changes in plasma concentrations of high density lipoproteins (HDL) and triglycerides may partly explain the ability of cholesterol-lowering drugs to decrease the incidence of coronary heart disease. We measured the response of fasting plasma lipids, lipoproteins, and apolipoproteins in 46 subjects with Type IIa hypercholesterolemia treated with simvastatin for 3 months. The initial dose of simvastatin (10 mg/day) was subsequently increased up to 40 mg/day if the plasma cholesterol concentration had not fallen below 5.2 mmol/l. Plasma concentrations of HDL cholesterol and of the apolipoproteins AI and AII were increased by simvastatin. The increase in HDL cholesterol (9%) was due to increases in both subfractions (HDL2 17%; HDL3 7%), changes that would be consistent with a beneficial effect on cardiovascular risk. Simvastatin decreased plasma triglyceride concentrations by 25%. Plasma total cholesterol concentrations fell by 35% after 3 months of treatment; this fall was proportional to the initial concentration and was due almost entirely to a 45% fall in low density lipoprotein cholesterol. In contrast, plasma concentrations of lipoprotein Lp(a) were not affected by simvastatin.

Danazol induces resistance to both insulin and glucagon in young women

1. Danazol elevates plasma insulin, plasma glucagon and serum low-density lipoprotein concentrations and reduces the serum high-density lipoprotein concentration. 2. Associations between these disturbances were studied in 17 women receiving danazol therapy for endometriosis. Eleven women underwent intravenous glucose tolerance tests with measurement of plasma glucose, insulin, C-peptide and glucagon concentrations and modelling analysis of intravenous glucose tolerance test concentration profiles. Six women underwent glucagon sensitivity tests. Serum concentrations of lipids and lipoproteins were measured in all cases. 3. Danazol reduced the fasting plasma glucose and insulin concentrations, but markedly raised the fasting plasma glucagon concentration. The insulin and C-peptide responses to the intravenous glucose tolerance test were increased twofold and the net decrement in glucagon concentration was increased tenfold. The glucose response to the intravenous glucose tolerance test was unaffected. Insulin sensitivity was reduced by 55%. Both first-phase plasma insulin responsiveness and net first-phase pancreatic insulin secretion were increased; insulin half-life was prolonged. The glucose response to the glucagon sensitivity test was reduced on treatment. The calculated low-density lipoprotein cholesterol level rose by 20%, whereas high-density lipoprotein cholesterol level fell by 47%. None of these changes in serum lipoprotein levels correlated with changes in insulin metabolism. In general, metabolic changes normalized after 3 months. 4. Danazol increases the sensitivity of pancreatic insulin and glucagon secretion to glucose. Danazol-induced insulin and glucagon resistance could be due to receptor down-regulation resulting from hypersecretion of insulin and glucagon.

Changes in body composition with danazol therapy

Whole body lean and fat mass measurements by dual energy x-ray absorptiometry were performed in 14 premenopausal women undergoing danazol treatment for endometriosis. After 6 months, there was a significant increase in lean tissue mass. Body fat decreased but this was significantly less in the android (upper body segment) region than in the gynoid (lower body segment) region. Danazol thus has both anabolic and androgenic effects on body composition. Dual energy x-ray absorptiometry provides a new, noninvasive, and rapid means of studying body composition.

Chicken parathyroid hormone-related protein and its expression during embryologic development

A parathyroid hormone-related protein (PTHrP) is the probable cause of humoral hypercalcemia in malignancy, but its normal physiologic role remains unknown. Since current evidence suggests that PTHrP may have a role in embryonic development, we cloned a genomic fragment that encodes chicken PTHrP (cPTHrP) and studied the expression of PTHrP in developing chick embryos. Blot hybridization of chicken genomic DNA with a cPTHrP genomic DNA probe showed a single band, suggesting that a single-copy gene encodes cPTHrP. By screening a chicken genomic library with the human probe an open reading frame was identified that corresponds to the human PTHrP (hPTHrP) exon IV. Compared to the human sequence the 5' splice junction is highly conserved and the two predicted propeptide residues are identical. The sequence predicts a mature peptide of 139 amino acids; all of the first 21 and 94 of the first 112, but only 8 of the final 27 residues of cPTHrP are identical to the human sequence. The structural features required for PTH receptor binding and activation are highly conserved between chicken and hPTHrP. Poly(A)-enriched RNA from 3-15 day chicken embryos was surveyed by hybridization to the chicken probe. A hybridizing band of 1.45 kb was found in tissues derived from all three germ layers, including brain, heart, lung, liver, gizzard, intestine, chorioallantoic membrane, yolk sac, and skeletal muscle. An additional 1.2 kb hybridizing band was found in some tissues. The conservation of the PTHrP sequence between chicken and mammals supports the view that PTHrP has an important physiologic role.(ABSTRACT TRUNCATED AT 250 WORDS)

A case of Datisca glomerata poisoning in beef cattle

Six of 175 Angus heifers died after ingesting excessive amounts of Durango root (Datisca glomerata). Animals had rumens full of Durango root, were extremely lethargic, and had diarrhea prior to death. The animals had nonspecific postmortem lesions. This case is discussed in light of previous findings from trials in which Durango root was experimentally fed to cattle.