The estimation of different ELISA procedures for serodiagnosis of human trichinellosis

Introduction. The most important confirmative diagnostic test for trichinellosis is the presence of the muscle larvae in a tissue biopsy but this direct method has a low sensitivity of light and moderate infections. The aim of presented study was to compare the usefulness of the results obtained by three ELISA procedures for Trichinella spp. diagnosis in human outbreaks. Materials and methods. All sera (cases and controls) were tested for anti-Trichinella antibodies (immunoglobulin G) using commercially available Novatec KIT and two other ELISA procedures based on excretory-secretory (ES) antigens on Trichinella spiralis muscle larvae. The main differences in ELISA procedures were: the protein concentration in antigen, dilution of human serum samples, conjugate and the time of conjugate incubation. Additional differences were noticed in ES antigen preparation procedures as well as in T. spiralis isolates used in these procedures. Serum samples were obtained from 22 symptomatical patients from Poznań region (West Poland), geographic area where human outbreak had occurred. Control serum samples were obtained from 20 patients from an open population from a non endemic trichinellosis area. Results. The results were analyzed in terms of both: statistical and epidemiological point of view. Linear regression analysis and correlations coefficient r between OD values of total 22 patients obtained in three ELISA procedures were positive and high statistically significant. Three ELISA procedures revealed different cut-off values and positivity rates for outbreak. However, the majority of positive samples were found as positive in three procedures, but some of them were positive in two or one procedure only. These individual variability in sera reactivity observed in three ELISA procedures could be very important from epidemiological point of view

Evaluation of candidate biomarkers to predict cancer cell sensitivity or resistance to PARP-1 inhibitor treatment

Impaired DNA damage response pathways may create vulnerabilities of cancer cells that can be exploited therapeutically. One such selective vulnerability is the sensitivity of BRCA1- or BRCA2-defective tumors (hence defective in DNA repair by homologous recombination, HR) to inhibitors of the poly(ADP-ribose) polymerase-1 (PARP-1), an enzyme critical for repair pathways alternative to HR. While promising, treatment with PARP-1 inhibitors (PARP-1i) faces some hurdles, including (1) acquired resistance, (2) search for other sensitizing, non-BRCA1/2 cancer defects and (3) lack of biomarkers to predict response to PARP-1i. Here we addressed these issues using PARP-1i on 20 human cell lines from carcinomas of the breast, prostate, colon, pancreas and ovary. Aberrations of the Mre11-Rad50-Nbs1 (MRN) complex sensitized cancer cells to PARP-1i, while p53 status was less predictive, even in response to PARP-1i combinations with camptothecin or ionizing radiation. Furthermore, monitoring PARsylation and Rad51 foci formation as surrogate markers for PARP activity and HR, respectively, supported their candidacy for biomarkers of PARP-1i responses. As to resistance mechanisms, we confirmed the role of the multidrug resistance efflux transporters and its reversibility. More importantly, we demonstrated that shRNA lentivirus-mediated depletion of 53BP1 in human BRCA1-mutant breast cancer cells increased their resistance to PARP-1i. Given the preferential loss of 53BP1 in BRCA-defective and triple-negative breast carcinomas, our findings warrant assessment of 53BP1 among candidate predictive biomarkers of response to PARPi. Overall, this study helps characterize genetic and functional determinants of cellular responses to PARP-1i and contributes to the search for biomarkers to exploit PARP inhibitors in cancer therapy

Design, synthesis and biological activities of new brassinosteroid analogues with a phenyl group in the side chain

We have prepared and studied a series of new brassinosteroid derivatives with a p-substituted phenyl group in the side chain. To obtain the best comparison between molecular docking and biological activities both types of brassinosteroids were synthesized; 6-ketones, 10 examples, and B-lactones, 8 examples. The phenyl group was introduced into the steroid skeleton by Horner-Wadsworth-Emmons. The docking studies were carried out using AutoDock Vina 1.05. Plant biological activities were established using different brassinosteroid bioassays in comparison with natural brassinosteroids. Differences in the production of the plant hormone ethylene were also observed in etiolated pea seedlings after treatment with new brassinosteroids. The most active compounds were lactone 8f and 6-oxo derivatives 8c and 9c, their biological activities were comparable or even better than naturally occurring brassinolide. Finally the cytotoxicity of the new derivatives was studied using human normal and cancer cell lines

TIS7 interacts with the mammalian SIN3 histone deacetylase complex in epithelial cells

The mammalian SIN3 complex consists of histone deacetylases (HDAC1, HDAC2), several known proteins (SAP30, N-CoR) and as yet unidentified proteins. Here we show that the mouse tetradecanoyl phorbol acetate induced sequence 7 (TIS7) protein is a novel transcriptional co-repressor that can associate with the SIN3 complex. We have identified tis7 as a gene that is up-regulated upon loss of polarity in a mouse mammary gland epithelial cell line expressing an estrogen-inducible c-JunER fusion protein. In unpolarized cells, TIS7 protein levels increase and TIS7 translocates into the nucleus. Overexpression of tis7 causes loss of polarity and represses a set of genes, as revealed by cDNA microarray analysis. We have shown that TIS7 protein interacts with several proteins of the SIN3 complex (mSin3B, HDAC1, N-CoR and SAP30) by yeast two-hybrid screening and co-immunoprecipitations. TIS7 co-immunoprecipitated HDAC complex is enzymatically active and represses a GAL4-dependent reporter transcription. The transcriptional repression of endogenous genes by tis7 overexpression is HDAC dependent. Thus, we propose TIS7 as a transcriptional co-repressor affecting the expression of specific genes in a HDAC activity-dependent manner during cell fate decisions, e.g. scattering