D-dimer as a possible prognostic marker of operable hormone receptor-negative breast cancer

BACKGROUND

Breast cancer is the most common cause of death in women by neoplasia. The mechanisms related to recurrence are unclear, specially the hemostatic alterations that occur during the development of the disease. Plasma D-dimer is a hypercoagulability and fibrinolytic system marker and is increased in patients with various solid tumors. The purpose of this study was to evaluate the hemostatic status assessed by plasma D-dimer in operable breast cancer patients and to investigate its value as a prognostic marker.

MATERIALS AND METHODS

The study comprised 32 patients with operable hormone receptor-negative breast cancer and a control group with 43 healthy women. Variables included presence and absence of breast cancer, clinical and histopathology findings, and overall survival.

RESULTS

Plasma D-dimer level was normal in the control group and significantly higher in breast cancer patients (P = 0.001), as well as in nonsurvivors compared with survivors (P = 0.025). The results showed that plasma D-dimer levels were not correlated with clinical and histopathology findings (P > 0.213).

CONCLUSIONS

The results taken together indicate the presence of a hypercoagulability state in women with operable hormone receptor-negative breast cancer given the increased levels of D-dimer in this group. Therefore, considering higher levels of D-dimer in patients with a poor outcome, its evaluation may be a promising tool for prognosis in women with operable hormone receptor-negative breast cancer.

Treatment of human cancer cells with selenite or tellurite in combination with auranofin enhances cell death due to redox shift

Selenium is an essential trace element incorporated as selenocysteine in 25 human selenoproteins. Among them are thioredoxin reductases (TrxR) and glutathione peroxidases, all central proteins in the regulation of the cellular thiol redox state. In this paper the effects of selenite and tellurite treatment in human cancer cells are reported and compared. Our results show that both selenite and tellurite, at relatively low concentrations, are able to increase the expression of mitochondrial and cytosolic TrxR in cisplatin-sensitive (2008) and -resistant (C13*) phenotypes. We further investigated the cellular effects induced by selenite or tellurite in combination with the specific TrxR inhibitor auranofin. Selenite pretreatment induced a dramatic increase in auranofin cytotoxicity in both resistant and sensitive cells. Investigation of TrxR activity and expression levels as well as the cellular redox state demonstrated the involvement of TrxR inhibition and redox changes in selenite and auranofin combined action.

Phenotype-dependent apoptosis signalling in mesothelioma cells after selenite exposure

Background

Selenite is a promising anticancer agent which has been shown to induce apoptosis in malignant mesothelioma cells in a phenotype-dependent manner, where cells of the chemoresistant sarcomatoid phenotype are more sensitive.

Methods

In this paper, we investigate the apoptosis signalling mechanisms in sarcomatoid and epithelioid mesothelioma cells after selenite treatment. Apoptosis was measured with the Annexin-PI assay. The mitochondrial membrane potential, the expression of Bax, Bcl-XL, and the activation of caspase-3 were assayed with flow cytometry and a cytokeratin 18 cleavage assay. Signalling through JNK, p38, p53, and cathepsins B, D, and E was investigated with chemical inhibitors. Furthermore, the expression, nuclear translocation and DNA-binding activity of p53 was investigated using ICC, EMSA and the monitoring of p21 expression as a downstream event. Levels of thioredoxin (Trx) were measured by ELISA.

Results

In both cell lines, 10 μM selenite caused apoptosis and a marked loss of mitochondrial membrane potential. Bax was up-regulated only in the sarcomatoid cell line, while the epithelioid cell line down-regulated Bcl-XL and showed greater caspase-3 activation. Nuclear translocation of p53 was seen in both cell lines, but very little p21 expression was induced. Chemical inhibition of p53 did not protect the cells from apoptosis. p53 lost its DNA binding ability after selenite treatment and was enriched in an inactive form. Levels of thioredoxin decreased after selenite treatment. Chemical inhibition of MAP kinases and cathepsins showed that p38 and cathepsin B had some mediatory effect while JNK had an anti-apoptotic role.

Conclusion

We delineate pathways of apoptosis signalling in response to selenite, showing differences between epithelioid and sarcomatoid mesothelioma cells. These differences may partly explain why sarcomatoid cells are more sensitive to selenite.

Selenite is a potent cytotoxic agent for human primary AML cells

Selenite is a potent inhibitor of malignant cell growth. Although the cytotoxic effects have been extensively investigated in vitro, there are only a limited number of studies using primary tumor cells with concomitant comparison to conventional drugs. An ex vivo model with primary cells from 39 consecutive patients with acute myeloid leukemia (AML) were exposed to a panel of conventional cytotoxic drugs, and the effects on viability were compared to those of clinically achievable concentrations of selenite. Selenite at 5 microM caused the lowest mean survival of primary tumor cells in the panel of all tested drugs (28.95% CI 18.60-39.30%). The cells showed a significant (p<0.05) correlation in the resistance to all tested conventional AML drugs whereas selenite did not, indicating sensitivity to selenite also in multi drug resistant cells. Exposure to selenite also resulted in an increased mRNA expression of the antioxidant proteins TrxR1 and Grx, while staining for TrxR1 showed decreased protein levels. The results strongly suggest a great potential for selenite in the treatment of multi drug resistant AML.

Effects of the antioxidant Pycnogenol on cellular redox systems in U1285 human lung carcinoma cells

Pycnogenol, which is extracted from the bark of French maritime pine, has been shown to have antioxidant and free radical scavenging activities. Thioredoxin reductase (TrxR), glutathione peroxidase (GPx) and glutathione reductase (GR) are three central redox enzymes that are active in endogenous defence against oxidative stress in the cell. Treatment of cells with Pycnogenol decreased the activity of both TrxR and GPx in cells by more than 50%, but GR was not affected. As previously reported, both enzymes were induced after treatment with hydrogen peroxide and selenite. The presence of Pycnogenol efficiently decreased selenite-mediated reactive oxygen species (ROS) production. Addition of Pycnogenol after selenite treatment reduced the mRNA expression and activity of TrxR to basal levels. In contrast, the GPx activity was completely unaffected. The discrepancy between TrxR and GPx regulation may indicate that transcription of TrxR is induced primarily by oxidative stress. As TrxR is induced in various pathological conditions, including tumours and inflammatory conditions, decreased activity mediated by a non-toxic agent such as Pycnogenol may be of great value.

Founder effect of the 669insA mutation in BSCL2 gene causing Berardinelli-Seip congenital lipodystrophy in a cluster from Brazil

Congenital generalized lipodystrophy (CGL) or Berardinelli-Seip Syndrome (BSCL) is a rare autosomal recessive disease characterized by a nearly-complete absence of adipose tissue from birth and severe metabolic alterations. The 669insA mutation in exon 4 of the BSCL2 gene was identified as the major genetic alteration leading to BSCL in a group of 22 patients from the northeastern Brazilian state of Rio Grande do Norte. Aiming to investigate the causes of the high frequency of BSCL in this region, a molecular genetic study was conducted using eight microsatelite markers located in chromosome 11. Additional investigations concerning the proportion of expected homozygous and heterozygous individuals, genetic diversity, fixation index and coefficient of endogamy were undertaken, and indicated significant differences by comparing the allelic and haplotypic frequencies observed for the BSCL affected families and the control group. It was concluded that a founder effect, genetic drift and consanguineous marriages have significantly affected the structure of this population, resulting in the highest frequency of BSCL in Brazil.

Increased expression of specific thioredoxin family proteins; a pilot immunohistochemical study on human hepatocellular carcinoma

Hepatocellular Carcinoma (HCC) is one of the most frequent cancers worldwide, however, prognosis remains poor following its discovery. We investigate the Thioredoxin superfamily of proteins as diagnostic markers for HCC. Furthermore, we delineate possible roles of the endoplasmic reticulum member of the superfamily, ERdj5, in carcinogenesis. Using antibodies against Thioredoxin 1, Thioredoxin Reductase 1 and ERdj5, we performed immunohistochemistry on paraffin embedded liver biopsy sections from HCC patients. All three redox proteins exhibited elevated expression levels in tumor tissue compared to internal control, with ERdj5 showing a remarkable 3-fold increase. In vitro cell viability experiments using Hepatocellular Carcinoma HuH7 cells treated with ERdj5 small interfering RNA showed that ERdj5 knockdown cells exhibited less resistance to Doxorubicin (chemotherapy drug), but more resistance to Tunicamycin (Endoplasmic Stress inducer), compared to control cells. In conclusion, we introduce members of the Thioredoxin superfamily as possible immunohistochemical markers in the diagnostics of hepatocellular carcinoma and indicate a potential defensive role for ERdj5 in chemotherapeutic drug resistance.

Quantification of alternative mRNA species and identification of thioredoxin reductase 1 isoforms in human tumor cells

The human selenoenzyme thioredoxin reductase 1 (TrxR1) is a very important enzyme for cell growth, differentiation, and the defense against oxidative stress. Several studies have shown that TrxR1 is up-regulated in tumor cells. The regulation of TrxR1 is very complex and involves the expression of different transcript forms of mRNA. We have, by quantitative polymerase chain reaction, investigated the total expression of TrxR1 mRNA and quantified the expression of alternative mRNA forms (alpha1/2, alpha6, alpha7/8, alpha10/11, alpha13, gamma2-4, and beta1) in six different human malignant mesothelioma cell lines of epithelioid, sarcomatoid, or mixed phenotype. The most abundant alpha-form was surprisingly alpha1/2 and not the expected alpha7/8. Selenium treatment resulted in increased expression of all alpha-variants, except the alpha10/11, where the levels were unaffected. The expression of protein isoforms was studied and the less abundant forms TrxR1v.2, TrxR1v.3, and TrxR1v.5 were detected in cell lysates and in human tumor tissue, using specific peptide antibodies. Furthermore, TrxR1v.3 and TrxR1v.5, previously not identified in human cells, were detected by mass spectrometry. Our data show differential expression of TrxR1 mRNA forms in malignant mesothelioma of different phenotype, and investigation of alternative transcript variants of TrxR1 could be a valuable tool in the diagnostics and characterization of tumors.

Immunocytochemical localization of tubulins in spermatids and spermatozoa of Euptoieta hegesia (Lepidoptera: Nymphalidae)

A comparative analysis of the distribution of tubulin types in apyrene and eupyrene sperm of Euptoieta hegesia butterflies was carried out, also verifying the presence of tubulin in lacinate appendages of the eupyrene sperm. Ultrathin sections of LR White embedded spermatids and spermatozoa were labeled for alpha, beta, gamma, alpha-acetylated and alpha-tyrosinated tubulins. Apyrene and eupyrene spermatids show the same antibody recognition pattern for tubulins. All tubulin types were detected in axonemal microtubules. Alpha and gamma tubulins were also detected on the cytoplasmic microtubules. However, for beta and tyrosinated tubulins only scattered labeling was detected on cytoplasmic microtubules and acetylated tubulin was not detected. In apyrene and eupyrene spermatozoa only the axoneme labeling was analyzed since cytoplasmic microtubules no longer exist in these cells. Alpha, beta and tyrosinated tubulins were easily detected on the apyrene and eupyrene axoneme; gamma tubulin was strongly marked on eupyrene axonemes but was scattered on the apyrene ones. Acetylated tubulin appeared with scattered labeling on the axoneme of both sperm types. Our results demonstrate significant differences in tubulin distribution in apyrene and eupyrene axonemal and cytoplasmic microtubules. Extracellular structures, especially the lacinate appendages, were not labeled by antibodies for any tubulin.

Phenotypic heterogeneity in biochemical parameters correlates with mutations in AGPAT2 or Seipin genes among Berardinelli-Seip congenital lipodystrophy patients

The Berardinelli-Seip congenital lipodystrophy (BSCL) syndrome is characterized by a near-total congenital absence of fat and predisposition to develop diabetes mellitus. We have previously reported that 22 patients from 16 consanguineous pedigrees living in the northeastern region of Brazil had a homozygous 669insA mutation in the Seipin gene (BSCL2 locus), while all of the 10 investigated subjects from the southeastern region were homozygous for a 1036 bp deletion in the AGPAT2 gene (BSCL1 locus). In this study, we compared the serum insulin and insulin resistance (HOMA), leptin, triglyceride and fasting glucose levels in individuals of these two genetically distinct clusters of BSCL subjects. The onset of diabetes was also estimated. The fasting glucose and triglyceride levels were not significantly different in these groups. Significant differences were detected for leptin, insulin and insulin resistance. BSCL1 patients presented lower serum leptin levels compared to BSCL2 patients. BSCL2 subjects had earlier onset of diabetes and higher insulin levels. In agreement, BSCL2 patients were more insulin resistant, as detected by HOMA. These results indicate phenotypic heterogeneity between BSCL1 and BSCL2 Brazilian subjects.

An ultrastructural study of sperm of the genus Bufo (Amphibia, Anura, Bufonidae)

The sperm ultrastructure of Bufo schineideri and B. granulosus consists of entwined seminiferous tubules formed by groups of germ cells and Sertoli cells. The spermatozoa of B. schineideri and B. granulosus measure about 66.7 microm and 85.4 microm in length, respectively. The head measures approximately 24.8 microm in B. schineideri and 17.7 microm in B. granulosus and consists of a single vesicle acrosomal, subacrosomal cone and nucleus. The midpiece measures approximately 3.8 microm in B. schineideri and 2.5 microm in B. granulosus and presents a mitochondrial collar around the tail. The tail consists of a typical axoneme, 9 + 2 microtubules, paraxonemal rod, axial sheath and axial fiber. The axial fiber extends through an electrondense structure that supports the undulating membrane. The structure and ultrastructure of the spermatozoa of the species here described are similar to the majority of sperm found in the other bufonids and may be a contribution for future phylogenetic analysis.

Wortmannin enhances the induction of micronuclei by low and high LET radiation

In mammalian cells, the repair of DNA double-strand breaks (DSBs) is mainly mediated by DNA non-homologous end joining. DNA-dependent protein kinase (DNA-PK), a nuclear serine-threonine kinase and a member of the phosphaditylinositol-3 kinase-related kinase family that is activated by DSBs, is a key component of this pathway. Wortmannin (WM) is known to be an irreversible and potent inhibitor of DNA-PK and has thus been proposed as an effective sensitizer for ionizing radiation and for radiomimetic compounds. The present study, using the cytokinesis block micronucleus assay, reports on the differential effect of WM on the repair of the DNA damage induced by low LET ((60)Co gamma-radiation) and high LET radiation by the boron neutron capture reaction (alpha and Li particles) in V79 Chinese hamster cells. Significant increases in the number of micronuclei per binucleated cell as well as in the frequency of micronucleated binucleated cells were observed in the presence of different concentrations of WM for high LET radiation from the boron neutron capture reaction. The increases observed reached a maximum of approximately 2-fold in comparison with the respective controls. WM, however, had a more pronounced effect on (60)Co gamma-radiation-induced micronuclei, increasing the genotoxic damage from this radiation by approximately 3- to 4-fold. These results are in general in agreement with the concept that DSBs induced by high LET radiation are not a more suitable substrate for the end joining processes mediated by DNA-PK, yet they do not preclude a role for DNA-PK in high LET-induced damage repair.

Spermiogenesis in Melanophryniscus cambaraensis (Amphibia, Anura, Bufonidae): ultrastructural and cytochemical studies of carbohydrates using lectins

Spermiogenesis in the bufonid Melanophryniscus cambaraensis was analysed ultrastructurally. The nucleus of spermatids undergoes morphological modifications divided into five distinct stages based on chromatin condensation. The acrosomal vesicle differentiates into an acrosome and a subacrosomal cone, which cap the anterior region of the nucleus. The spermatozoa consist of the head with a nucleus and acrosomal complex and the tail, with an axoneme, an axial rod and an undulating membrane. The participation of several carbohydrate moieties during this differentiation process was detected using various gold-labelled lectins.

Evaluation of the genotoxic effects of the boron neutron capture reaction in human melanoma cells using the cytokinesis block micronucleus assay

The present work reports on the genotoxicity of the boron neutron capture (BNC) reaction in human metastatic melanoma cells (A2058) assessed by the cytokinesis block micronucleus assay (CBMN) using p-borono-L-phenylalanine (BPA) as the boron delivery agent. Different concentrations of BPA (0.48, 1.2 and 2.4 mM) and different fluences of thermal neutrons were studied. Substantial genotoxic potential of alpha and lithium particles generated inside or near the malignant cell by the BNC reaction was observed in a dose-response manner as measured by the frequency of micronucleated binucleated melanoma cells and by the number of micronuclei (MN) per binucleated cell. The distribution of the number of MN per micronucleated binucleated cell was also studied. The BNC reaction clearly modifies this distribution, increasing the frequency of micronucleated cells with 2 and, especially, > or =3 MN and conversely decreasing the frequency of micronucleated cells with 1 MN. A decrease in cell proliferation was also observed which correlated with MN formation. A discrete genotoxic and anti-proliferative contribution from both thermal neutron irradiation and BPA was observed and should be considered secondary. Additionally, V79 Chinese hamster cells (chromosomal aberrations assay) and human lymphocytes (CBMN assay) incubated with different concentrations of BPA alone did not show any evidence of genotoxicity. The presented results reinforce the usefulness of the CBMN assay as an alternative method for assessment of the deleterious effects induced by high LET radiation produced by the BNC reaction in human melanoma cells.

Detection of calcium and calmodulin during spermiogenesis of phytophagous bugs (Hemiptera: Pentatomidae)

The ultrastructural detection of calcium using pyroantimonate, and the immunocytochemical localization of calmodulin using monoclonal antibody were carried out during the spermiogenesis of phytophagous bugs. The presence of calcium was observed on the Golgi apparatus during the initial phases of spermiogenesis. In the other stages the calcium was observed in association with the nucleus and in some regions of acrosome. Indeed, it was detected surrounding the mitochondrial derivatives and specific axonemal microtubules on the tail region. The immunocytochemical detection of calmodulin showed the presence of this protein approximately in the same regions where the calcium was detected, indicating that calcium and calmodulin could work together during spermiogenesis of this phytophagous bugs, suggesting their involvement on the regulation of flagellar beating, nuclear compactation and acrosome formation.

Combined interleukin-12 and topical chemotherapy for established Leishmaniasis drastically reduces tissue parasitism and relapses in susceptible mice

The efficacy of the association of paromomycin sulfate (PA) with recombinant (r) interleukin (IL)-12 was investigated by topical treatment of BALB/c mice infected with Leishmania major that displayed fully developed cutaneous lesions. Although healing was observed in PA-treated groups, lesions recurred in 100% of these animals 70 days after treatment. In contrast, lesions were absent in a high proportion of PA- and rIL-12-treated mice 120 days after treatment. The PA/rIL-12-treated mice had a switch in cytokine response, from high IL-4 and low interferon (IFN)-gamma levels to low IL-4 and high IFN-gamma levels, and reductions in parasite load, dissemination of parasites, and inflammation. Thus, the association of rIL-12 to topical chemotherapy for leishmaniasis may be an important strategy for increasing cure rates and decreasing the incidence of relapse.

Nuclear changes and acrosome formation during spermiogenesis in Euchistus heros (Hemiptera: Pentatomidae)

Ultrastructural and cytochemical studies were carried out on nuclear changes and acrosome formation during the spermiogenesis of the phytophagous bug Euchistus heros. The development of the nucleus involves changes in the shape and in degree of chromatin condensation: initially it is dispersed and with a low-electron density, then assumes a fibrillar arrangement and finally compacts in an electron-dense material. The acrosome is formed by the Golgi complex and presents unusual morphological features during its development. The reaction product of acid phosphatase, glucose-6-phosphatase and thiamine pyrophosphatase activities were detected during various stages of acrosome development. In contrast, residues of alpha-N-acetylgalactosamine and basic proteins were only reported in the intermediate and late stages of the differentiation process, respectively.

Brazilian population database for the 13 STR loci of the AmpFlSTR Profiler Plus and Cofiler multiplex kits

Allele frequencies for the 13 STR core loci (D3S1358, VWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820, CSF1PO, TPOX, THO1 and D16S539) included in the AmpFlSTR((R)) Profiler Plus and AmpFlSTR((R)) Cofiler kits were obtained for a sample of 700-800 genetically unrelated Brazilians. The expected performance of these loci for personal identification and paternity testing in the Brazilian population was estimated.

Ultrastructural and cytochemical studies of the spermatozoa of Acrosternum aseadum (Hemiptera: Pentatomidae) after copulation

Beside the morphofunctional modifications undergone during spermiogenesis, the spermatozoon could undergo other modifications after copulation. Since no structural modification occurs in the spermatozoon of Acrosternum aseadum after copulation, we used cytochemical studies to show the enzymatic activities variations of acid phosphatase, thiamine pyrophosphatase, glucose-6-phosphatase and cytochrome C oxidase, when the spermatozoon passes through the spermatheca. The enzymatic activity, few hours after copulation, is strong and specifically located. However, 40 h after copulation, there is considerable loss of enzymatic activity, with the exception of thiamine pyrophosphatase, which shows the same activity. This result indicates that the spermatozoon of A. aseadum undergoes physiological modifications when passing through the spermatheca and that these modifications may be involved with survival in this organ as well as with the fertilization process.

Glucose-mediated Ca(2+) signalling in single clonal insulin-secreting cells: evidence for a mixed model of cellular activation

Using clonal insulin-secreting BRIN-BD11 cells, we have assessed whether the graded response of the whole cell population to glucose can be accounted for by a dose-dependent recruitment of individual cells, an amplification of the response of the recruited cells or both. Cytosolic free Ca(2+) concentration ([Ca(2+)](i)) is an established index of beta-cell function. We used fura-2 microfluorescence techniques to assess the [Ca(2+)](i) responsiveness of single BRIN-BD11 cells to glucose and other secretagogues. Glucose (1-16.7 mM) evoked oscillatory [Ca(2+)](i) rises in these cells resembling those found in parental rat pancreatic beta-cells. The percentage of glucose-responsive cells was 11% at 1 mM and increased to 40-70% at 3-16.7 mM glucose, as assessed by a single-stimulation protocol. This profile was unrelated to possible differences in the cell cycle, as inferred from experiments where the cultured cells were synchronized by a double thymidine block protocol. Individual cells exhibited variable sensitivities to glucose (threshold range: 1-5 mM) and a variable dose-dependent amplification of the [Ca(2+)](i) responses (EC(50) range: 2-10 mM), as assessed by a multiple-stimulation protocol. Glyceraldehyde and alpha-ketoisocaproic acid had glucose-like effects on [Ca(2+)](i). The data support a mixed model for the activation of insulin-secreting cells. Specifically, the graded secretory response of the whole cell population is likely to reflect both a recruitment of individual cells with different sensitivities to glucose and a dose-dependent amplification of the response of the recruited cells.

An ultrastructural study of spermiogenesis in three species of Physalaemus (Anura, Leptodactylidae)

Ultrastructural aspects of spermiogenesis and testicular spermatozoa of three anuran amphibians, Physalaemus biligonigerus, P. fuscomaculatus and P. gracilis, were investigated by electron microscopy. The nuclei, middle pieces and tails of the three species were similar. In all cases, the nuclei were elongated and the acrosome consisted of a cone-shaped cap. The connecting pieces located in the flagellum implantation zone had transverse striations. The tails had a 9 + 2 axial filament pattern, a juxtaxonemal fiber and an undulating membrane. In contrast to other Leptodactylidae spermatozoa, no axial rod were observed in these Physalaemus species.