Abstract P4-09-04: Robust 7-gene signature for recurrence prognosis of breast cancer validated in formalin-fixed paraffin-embedded samples

BACKGROUND: Breast cancer (BC) is a heterogeneous disease with diverse biological-molecular characteristics and clinical behaviors. Traditionally, prediction of recurrence in patients recently diagnosed is a big challenge for oncologists. In the last decade, advances in gene expression profiling technologies have improved the genetic knowledge of breast cancer by reporting several prognostic gene-signatures. However, there is still a need for covering the molecular heterogeneity of this cancer. Integration of public microarray data could be used to identify better and robust predictive gene-signatures. The aim of this study was to investigate prognostic genes that might function as biomarkers to differentiate among all heterogeneous BC patients, into those with high, medium or low recurrence risk.

METHODS: We collected nine public datasets, 1574 BC patients with median follow-up time of 10 years. The data were split into train-test, 50% each. Train was subject to univariate and multivariate analysis to generate a signature, which was validated in the test data. Seven genes were identified with high accuracy for recurrence prediction. This signature was validated in 40 formalin-fixed paraffin-embedded (FFPE) Mexican BC tissues with clinical follow up of 3 to 13 years by quantitative RT-PCR assays.

RESULTS: We identified a 7-gene signature which showed an accuracy prediction measured by concordance index of 65.62% and Log-rank test p-value: 1 x 10-15. The validation of the gene-signature level expression in 40 FFPE samples in Kaplan Meier analysis showed prediction significance by concordance index of 65.25% and Log-Rank p-value: 0.0005.

CONCLUSIONS: This 7-gene signature may provide a powerful tool to guide the adequate treatment protocols in early-diagnosed breast cancer patients.

Citation Format: Chacolla RJ, Trevino VM, Scott SP, Guzman EA, Cardona S. Robust 7-gene signature for recurrence prognosis of breast cancer validated in formalin-fixed paraffin-embedded samples. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-09-04.

Prevalence of Methylenetetrahydrofolate Reductase C677T and A1298C Polymorphisms and Risk of Breast Cancer in Mexican Women: An Interim Report of a Case-Control Study

Background: Among other causes, Breast Cancer (BC) appears as a result of genetic and epigenetic changes. Modifications in important pathways, such as the reactions that provide essential cofactors for synthesis of S-adenosylmethionine (one-carbon metabolism), and those involved in DNA synthesis and methylation could be linked to the development of this disease. Research has been conducted about whether MTHFR polymorphisms are related to the development of breast cancer in at least 10 different races, with different outcomes. Two of the most frequently studied MTHFR polymorphisms are C677T and A1298C, and their frequency is unknown among Mexican women. Our objective was to determine the frequency of these two polymorphisms and to ascertain weather their presence increases the risk of developing BC in our population.Materials and methods: 37 blood samples from histopatologically confirmed breast cancer patients were collected from hospitals in Monterrey, Uruapan and Villahermosa, all in Mexico. 115 healthy control samples were obtained from the same cities, and were matched for age in 5-year interval-groups. Cases and controls were third generation Mexican and older than 18 years. Genotyping of every sample was performed by PCR and restriction with enzymes.Results: The C677T Polymorphism was found in 28 cases (75.67%), whereas 76/115 controls (66.08%) showed the polymorphic allele. Case-controls analysis was adjusted to the confounding variable age group, an odds ratio of 1.58 (IC 95% de 0.66 – 3.82) was obtained. We did not find a significant relationship between the presence of the C677T polymorphism and the presence of breast cancer. The A1298C Polymorphism was found in 19/37 cases (51.35%), while only 32/115 (27.82%) of the control samples contained the allele. The odds ratio adjusted for the same confounding variable was 2.72 (IC 95%: 1.26 – 5.87). These results suggest a significant association between the presence of the polymorphism and BC.Discussion: Despite the exhaustive research that has been conducted regarding MTHFR polymorphisms C677T and A1298C, their association to the risk of breast cancer remains unclear. Some research groups even suggest that the presence of the polymorphisms, either individually or combined, confers certain protection against the disease. Up until now there were no data in Mexican population. Differences in the results of different works probably lie in the nature of the populations analyzed and the experimental design. We believe that a bigger sample size will allow us to determine if A1298C polymorphism is indeed, a risk factor for BC in Mexican women.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3064.

Evaluation of F18-deoxyglucose positron emission tomography (FDG-PET) to assess the nature of neurogenic tumours

AIMS

Benign neurofibromas and malignant peripheral nerve sheath tumours (MPNST) commonly develop in patients with neurofibromatosis. Differentiation of benign from malignant tumours by conventional preoperative imaging is unreliable. FDG-PET is a non-invasive technique for biological tumour evaluation. The aim of this study was to assess the value of FDG-PET in patients with neurogenic tumours suspicious for MPNST.

METHODS

Benign and malignant neurogenic soft tissue tumours were prospectively evaluated by computed tomography or magnetic resonance imaging. Three-dimensional qualitative and quantitative FDG-PET was performed. Standard uptake value (SUV) was analyzed with respect to histological diagnosis and follow-up data.

RESULTS

Twenty-five neurogenic soft tissue tumours were included. FDG-PET identified all primary (n=6) and recurrent MPNST (n=7). Benign lesions (n=12) did not demonstrate high FDG uptake. The SUV was significantly higher in MPNST (median 2.9; range 1.8-12.3), than in benign tumours (median 1.1; range 0.5-1.8) (p<0.001). At a cut-off value of 1.8 SUV measured 1 h post-injection FDG-PET distinguished between MPNST and benign neurogenic tumours with 100% sensitivity and 83% specificity.

CONCLUSIONS

FDG-PET allows discrimination of benign from malignant neurogenic tumours. This should be particularly useful in patients with neurofibromatosis as FDG-PET may help to avoid multiple surgical procedures for benign tumours.

The glycogen-bound polyphosphate kinase from Sulfolobus acidocaldarius is actually a glycogen synthase

Inorganic polyphosphate (polyP) is obtained by the polymerization of the terminal phosphate of ATP through the action of the enzyme polyphosphate kinase (PPK). Despite the presence of polyP in every living cell, a gene homologous to that of known PPKs is missing from the currently sequenced genomes of Eukarya, Archaea, and several bacteria. To further study the metabolism of polyP in Archaea, we followed the previously published purification procedure for a glycogen-bound protein of 57 kDa with PPK as well as glycosyl transferase (GT) activities from Sulfolobus acidocaldarius (R. Skórko, J. Osipiuk, and K. O. Stetter, J. Bacteriol. 171:5162-5164, 1989). In spite of using recently developed specific enzymatic methods to analyze polyP, we could not reproduce the reported PPK activity for the 57-kDa protein and the polyP presumed to be the product of the reaction most likely corresponded to glycogen-bound ATP under our experimental conditions. Furthermore, no PPK activity was found associated to any of the proteins bound to the glycogen-protein complex. We cloned the gene corresponding to the 57-kDa protein by using reverse genetics and functionally characterized it. The predicted product of the gene did not show similarity to any described PPK but to archaeal and bacterial glycogen synthases instead. In agreement with these results, the recombinant protein showed only GT activity. Interestingly, the GT from S. acidocaldarius was phosphorylated in vivo. In conclusion, our results convincingly demonstrate that the glycogen-protein complex of S. acidocaldarius does not contain a PPK activity and that what was previously reported as being glycogen-bound PPK is a bacterial enzyme-like thermostable glycogen synthase.

Assessment of soft tissue lesions suspicious for liposarcoma by F18-deoxyglucose (FDG) positron emission tomography (PET)

BACKGROUND

F18-deoxyglucose (FDG) positron emission tomography (PET) is a promising imaging technique. The aim of this study was to investigate the use of FDG PET in patients with suspected liposarcomas (LS).

PATIENTS AND METHODS

Forty-two masses were studied. The FDG uptake was estimated in tumor (T) and normal tissue (NT). The data were analyzed with respect to pathological findings.

RESULTS

Pathology revealed 11 primary LS, 14 locally recurrent LS, 5 other sarcomas, 1 inflammation, 1 lymphoma and 10 benign lesions. FDG uptake (T-to-NT ratio) in 25 LS corresponded with the histological subtype. Pleomorphic, mixed and myxoid LS showed an increased T-to-NT ratio and were thus visualized. Four out of six well-differentiated LS presented a low FDG uptake. Like subtype, the tumor grade also corresponded to FDG uptake. The T-to-NT ratio of higher grade LS, contrary to low grade LS, was uniformly increased. Primary LS were distinguishable from benign tumors, while other sarcomas, inflammation and lymphoma were not. Recurrence was detected with a sensitivity of 86% and a specificity of 100%. False-negative diagnoses occurred only in well-differentiated recurrences.

CONCLUSION

FDG uptake in LS correlates with the histological subtype and tumor grade. The diagnostic value of FDG PET in LS, therefore, is influenced by histomorphological parameters. Our data suggest that pleomorphic, mixed and higher-grade LS recurrences are preferentially amenable to FDG PET imaging.

Survey and critique of studies related to unlicensed assistive personnel from 1975 to 1997, Part 1

This descriptive integrated review of research on the use of unlicensed assistive personnel in nursing is presented in two parts. In this issue, part 1 describes the methods used to find and critique research related to unlicensed assistive personnel in nursing. It includes the conceptual model and findings related to the variables studied. Part 2 of this review, which is scheduled for publication in the next issue, will present research findings, conclusions, and recommendations.

Chloride transport activation by plasma osmolarity during rapid adaptation to high salinity of Fundulus heteroclitus

Transition from low salt water to sea water of the euryhaline fish, Fundulus heteroclitus, involves a rapid signal that induces salt secretion by the gill chloride cells. An increase of 65 mOsm in plasma osmolarity was found during the transition. The isolated, chloride-cell-rich opercular epithelium of sea-water-adapted Fundulus exposed to 50 mOsm mannitol on the basolateral side showed a 100% increase in chloride secretion, which was inhibited by bumetanide 10(-4) M and 10(-4) M DPC (N-Phenylanthranilic acid). No effect of these drugs was found on apical side exposure. A Na+/H+ exchanger, demonstrated by NH4Cl exposure, was inhibited by amiloride and its analogues and stimulated by IBMX, phorbol esters, and epithelial growth factor (EGF). Inhibition of the Na+/H+ exchanger blocks the chloride secretion increase due to basolateral hypertonicity. A Cl-/HCO3- exchanger was also found in the chloride cells, inhibited by 10(-4) M DIDS but not involved in the hyperosmotic response. Ca2+ concentration in the medium was critical for the stimulation of Cl- secretion to occur. Chloride cell volume shrinks in response to hypertonicity of the basolateral side in sea-water-adapted operculi; no effect was found on the apical side. Fresh-water-adapted fish chloride cells show increased water permeability of the apical side. It is concluded that the rapid signal for adaptation to higher salinities is an increased tonicity of the plasma that induces chloride cell shrinkage, increased chloride secretion with activation of the Na+K+2Cl- cotransporter, the Na+/H+ exchanger and opening of Cl- channels.

Autoantibodies against a novel DNA-binding protein: DNA-protein interaction as a requisite for expression of antigenic reactivity

A novel DNA-binding protein complex, the HB complex, has been characterized by means of autoantibodies. Three proteins of 9000, 7500, and 7000 Da constitute the HB complex. The 9000- and 7500-Da proteins are phosphorylated. Autoantibodies recognize the 7000-Da protein when it is bound to DNA. No reactivity against any protein was observed when the complex was dissociated from DNA. The three proteins are acidic (pI 5-6.2), and the complex was able to bind to synthetic double-stranded DNAs of different composition.

Peripheral blood and bone marrow immunophenotypic and functional modifications induced in acute leukemia patients treated with interleukin 2: evidence of in vivo lymphokine activated killer cell generation

The effect of treatment with interleukin 2 (IL2) on the phenotypic and functional immune system of acute leukemia patients was investigated. Fifteen acute myeloid leukemia and acute lymphoid leukemia patients with evidence of persistent disease were further subdivided into two groups according to the percentage of bone marrow (BM) blasts: group a had 6-15% blasts and group b had 30-65%. Following two cycles of IL2 (Glaxo Imb, Geneva, Switzerland) given i.v. by continuous infusion at escalating doses, no major changes in the proportion of CD3-, CD4-, and CD8-positive cells were encountered in the blood or in the marrow of either group of patients. When these could be retested after four cycles of IL2, a significant increase of CD3+ and CD4+ cells was documented in the peripheral blood (PB), as well as a significant increase of CD3+ cells in the BM. Irrespective of the number of cycles administered, the proportion of CD16+ cells increased significantly in the blood in both groups of patients and in the marrow of group a patients only. The expression of CD25 was significantly enhanced in all samples tested. Following IL2 administration, an enhancement of the natural killer compartment was documented. This was consistently more evident in patients with more limited disease. A significant amplification of the in vitro-induced lymphokine-activated killer function was noted in the BM of the treated patients. Furthermore, we documented the presence both in the PB and in the BM of "spontaneous" lymphokine-activated killer cells generated in vivo following IL2 administration. These results demonstrate that in acute leukemia of both myeloid and lymphoid origin, treatment with IL2 is capable of inducing profound immunophenotypic and functional modifications in PB and in BM lymphocytes, particularly in patients with more limited disease. The evidence of the in vivo activation of cytotoxic cells, particularly in the BM, may help to explain the clinical responses preliminarily observed in individual acute leukemia patients.

Lymphokine-activated killer (LAK) cell activity in B and T chronic lymphoid leukemia: defective LAK generation and reduced susceptibility of the leukemic cells to allogeneic and autologous LAK effectors

The capacity to generate lymphokine-activated killer (LAK) cells and the susceptibility of the neoplastic cells to both allogeneic and autologous LAK effectors were studied in B and T chronic lymphoproliferative disorders. While in B-cell chronic lymphocytic leukemia (B-CLL) the depressed natural killer function could be restored after a 7-day incubation with recombinant interleukin (IL-2), B-CLL mononuclear cells showed a reduced LAK activity compared with normal LAK cells. Furthermore, in all but 1 of the 20 B-CLL samples tested the leukemic cells were totally resistant to autologous LAK effectors. In most cases the leukemic cells were also resistant to normal allogeneic LAK cells. Competition experiments demonstrated that the patients' LAK cells, as well as normal LAK effectors, were capable of recognizing B-CLL cells, pointing, therefore, to a postbinding cytolytic defect. In hairy cell leukemia (HCL) an overall reduced LAK activity against allogeneic targets was documented, but, at variance from B-CLL, hairy cells were often susceptible to the lytic effect of normal LAK cells, and in half of the cases tested the neoplastic population was also sensitive in an autologous system. Similarly to B-CLL, in the great majority of T chronic lymphoproliferative disorders studied, the pathologic cells were resistant to normal and autologous LAK effectors and a defective LAK generation was found. These results demonstrate that in most B and T chronic leukemias the LAK function is defective and, when inducible, does not appear directed against the leukemic population. The possibility of exploiting an immunotherapeutic approach with IL-2/LAK cells in the management of chronic lymphoproliferative disorders does not gain support by these findings.

Production of tumor necrosis factor-alpha by B-cell chronic lymphocytic leukemia cells: a possible regulatory role of TNF in the progression of the disease

Tumor necrosis factor-alpha (TNF) is a cytokine that displays a pleomorphic array of effects on different cell populations. Evidence is presented that TNF may be constitutively produced by B-cell chronic lymphocytic leukemia (B-CLL) and hairy cell leukemia (HCL) cells and that it may play a relevant role in these diseases. These conclusions are based on the presence of circulating levels of TNF in the serum of 20 of the 24 patients tested (83.3%), while undetectable values were found in normal sera. The suggestion that the increased serum levels were due to the leukemic cell population is strengthened by the evidence that purified B-CLL and HCL cells may constitutively release variable degrees of TNF. These levels markedly increase after incubation with interferon gamma or phytohemagglutinin (PHA) plus phorbol myristate acetate (PMA). The cellular release of TNF by primary B-CLL cells was significantly (P less than .001) higher in B-CLL stage O-I patients compared with stage II-III patients. The demonstration that, in B-cell chronic lymphoproliferative disorders, the pathologic cells may release TNF was further confirmed by the presence of the mRNA for this cytokine in primary and/or in pre-activated cells. Recombinant TNF was capable of inducing a proliferative signal only in a minority of cases (4/24); in most cases it was ineffective, and, in a few, it reduced the degree of proliferation. Furthermore, in costimulatory experiments with interleukin-2 and PHA plus PMA, TNF was ineffective. On the other hand, when primary B-CLL cells were incubated in the presence of an anti-TNF antibody, in 8 of 12 independent experiments a 2- to 15-fold increase in thymidine uptake was documented. Taken together, these results suggest that TNF may play a regulatory role in the progression of the neoplastic clone in B-cell chronic lymphoproliferative disorders and may be implicated in some of the side effects associated with these diseases.

Interleukin 2 does not promote the in vitro and in vivo proliferation and growth of human acute leukaemia cells of myeloid and lymphoid origin

The effect of recombinant interleukin 2 (IL2) on the in vitro and in vivo proliferation and growth of human acute leukaemia cells of both myeloid and lymphoid origin was investigated. In none of the 25 primary samples tested could a continuously in vitro growing cell line be obtained by adding IL2 to the culture medium. Although IL2 induced a proliferative signal in three of the 31 acute leukaemias analysed, the overall 3H-thymidine uptake of the neoplastic cells was significantly reduced (P less than 0.05) in the presence of IL2. The unlikelihood of an important proliferative signal triggered by IL2 was confirmed in a semisolid clonogenic assay, which failed to document an increased colony growth in the 26 samples studied. Furthermore, using a colorimetric assay as a test for cell proliferation and survival, in seven of the 11 fresh acute leukaemia samples tested a 22-40% reduction in viability was observed in the presence of IL2, while in the remaining four, IL2 was ineffective. In order to investigate the effect of IL2 in an in vivo setting, an experimental model in heavily immunosuppressed nu/nu mice was established. In no case did IL2 promote the in vivo proliferation and growth of human myeloid and lymphoid acute leukaemia cells injected in the mice. On the contrary, with seven of the eight leukaemic cell lines which gave rise spontaneously to leukaemic masses, this could be prevented when the mice received locally 300 U of IL2 three times daily for 90 d. IL2 also blocked the growth in vivo of three fresh acute leukaemia samples (two myeloid and one lymphoid). Co-culture experiments using leukaemic cell lines and increasing numbers of normal lymphocytes suggest that the inhibitory effect of IL2 is probably exerted via an indirect mechanism. These findings, coupled to the well-documented ability of IL2 to generate lymphokine activated killer cells cytolytic against leukaemic blasts, further point to the potential role of immunotherapy with IL2 in the management of patients with haematological malignancies.

Lymphokine activated killer (LAK) activity in lymphoproliferative disorders

Lymphokine activated killer (LAK) cells are being considered as a new and promising form of immunotherapy in the management of patients with solid tumours. Few informations are instead available on these cytotoxic effectors in haematological neoplasias. Here we shall discuss the possible role of LAK cells in human leukaemias. Evidence will be provided for a rationale in the clinical exploitment of Interleukin 2 (IL2)/LAK cells in the treatment of acute leukaemia patients, whilst the implication of these cytotoxic populations appears more uncertain in chronic lymphoproliferative disorders.

[Enflurane-pancuronium combination: real progress toward greater safe conditions in general anesthesia]

The literature data and personal experience with high - and very high - risk patients show that the association of enflurane as anaesthetic and pancuronium as muscle-relaxant constitutes a positive advance in balanced general anaesthesia. Cardiocirculatory depression is not encountered; if anything, there is an improvement of homeostatic conditions. This results in increased safety, even for patients regarded as inoperable. Confirmation of the reasons for associating these two drugs has certainly been obtained. The method cannot, however, be employed indiscriminately, but, at least in theory, should be avoided in patients with serious hypertension or a myocardium that is particularly sensitive to endogenic catecholamine incretion. In hypotension, on the other hand, cases of imminent or frank shock, or situations where surgery cannot be postponed, the association is, paradoxically, a true pharmacological "support", backed up, of course, by other usual procedures. This contradiction of modern views concerning the peripheral circulation is only apparent, since the duration of anaesthesia is reduced; main aim in this period is the maintenance of sufficient circulation to the more important organs. Comparison with associations combining d-Tubocurarine, halothane and methoxyfluorane is still an open question as far as objective assessment of their usefulness is concerned. There can be no doubt, however, that the association of enflurane and pancuronium has eliminated a large sector of contraindications in the field of general anaesthesia.