Paving the way towards precise and safe CRISPR genome editing

As the possibilities of CRISPR-Cas9 technology have been revealed, we have entered a new era of research aimed at increasing its specificity and safety. This stage of technology development is necessary not only for its wider application in the clinic but also in basic research to better control the process of genome editing. Research during the past eight years has identified some factors influencing editing outcomes and led to the development of highly specific endonucleases, modified guide RNAs and computational tools supporting experiments. More recently, large-scale experiments revealed a previously overlooked feature: Cas9 can generate reproducible mutation patterns. As a result, it has become apparent that Cas9-induced double-strand break (DSB) repair is nonrandom and can be predicted to some extent. Here, we review the present state of knowledge regarding the specificity and safety of CRISPR-Cas9 technology to define gRNA, protein and target-related problems and solutions. These issues include sequence-specific off-target effects, immune responses, genetic variation and chromatin accessibility. We present new insights into the role of DNA repair in genome editing and define factors influencing editing outcomes. In addition, we propose practical guidelines for increasing the specificity of editing and discuss novel perspectives in improvement of this technology.

Computational Tools and Resources Supporting CRISPR-Cas Experiments

The CRISPR-Cas system has become a cutting-edge technology that revolutionized genome engineering. The use of Cas9 nuclease is currently the method of choice in most tasks requiring a specific DNA modification. The rapid development in the field of CRISPR-Cas is reflected by the constantly expanding ecosystem of computational tools aimed at facilitating experimental design and result analysis. The first group of CRISPR-Cas-related tools that we review is dedicated to aid in guide RNA design by prediction of their efficiency and specificity. The second, relatively new group of tools exploits the observed biases in repair outcomes to predict the results of CRISPR-Cas edits. The third class of tools is developed to assist in the evaluation of the editing outcomes by analysis of the sequencing data. These utilities are accompanied by relevant repositories and databases. Here we present a comprehensive and updated overview of the currently available CRISPR-Cas-related tools, from the perspective of a user who needs a convenient and reliable means to facilitate genome editing experiments at every step, from the guide RNA design to analysis of editing outcomes. Moreover, we discuss the current limitations and challenges that the field must overcome for further improvement in the CRISPR-Cas endeavor.

VirDB: Crowdsourced Database for Evaluation of Dynamical Viral Infection Models

Background:

Open science is an emerging movement underlining the importance of transparent, high quality research where results can be verified and reused by others. However, one of the biggest problems in replicating experiments is the lack of access to the data used by the authors. This problem also occurs during mathematical modeling of a viral infections. It is a process that can provide valuable insights into viral activity or into a drug’s mechanism of action when conducted correctly.

Objective:

We present the VirDB database (virdb.cs.put.poznan.pl), which has two primary objectives. First, it is a tool that enables collecting data on viral infections that could be used to develop new dynamic models of infections using the FAIR data sharing principles. Second, it allows storing references to descriptions of viral infection models, together with their evaluation results.

Methods:

To facilitate the fast population of database and the ease of exchange of scientific data, we decided to use crowdsourcing for collecting data. Such approach has already been proved to be very successful in projects such as Wikipedia.

Conclusion:

VirDB builds on the concepts and recommendations of Open Science and shares data using the FAIR principles. Thanks to this storing data required for designing and evaluating models of viral infections which can be freely available on the Internet.

Characterization of male breast cancer: results of the EORTC 10085/TBCRC/BIG/NABCG International Male Breast Cancer Program

Background

Male breast cancer (BC) is rare, managed by extrapolation from female BC. The International Male BC Program aims to better characterize and manage this disease. We report the results of part I, a retrospective joint analysis of cases diagnosed during a 20-year period.

Methods

Patients with follow-up and tumor samples, treated between 1990 and 2010, in 93 centers/9 countries. Samples were centrally analyzed in three laboratories (the United Kingdom, the Netherlands and the United States).

Results

Of 1822 patients enrolled, 1483 were analyzed; 63.5% were diagnosed between 2001 and 2010, 57 (5.1%) had metastatic disease (M1). Median age at diagnosis: 68.4 years. Of 1054 M0 cases, 56.2% were node-negative (N0) and 48.5% had T1 tumors; 4% had breast conserving surgery (BCS), 18% sentinel lymph-node biopsy; half received adjuvant radiotherapy; 29.8% (neo)adjuvant chemotherapy and 76.8% adjuvant endocrine therapy (ET), mostly tamoxifen (88.4%). Per central pathology, for M0 tumors: 84.8% ductal invasive carcinomas, 51.5% grade 2; 99.3% estrogen receptor (ER)-positive; 81.9% progesterone receptor (PR)-positive; 96.9% androgen receptor (AR)-positive [ER, PR or AR Allred score ≥3]; 61.1% Ki67 expression low (<14% positive cells); using immunohistochemistry (IHC) surrogates, 41.9% were Luminal-A-like, 48.6% Luminal-B-like/HER-2-negative, 8.7% HER-2-positive, 0.3% triple negative. Median follow-up: 8.2 years (0.0-23.8) for all, 7.2 years (0.0-23.2), for M0, 2.6 years (0.0-12.7) for M1 patients. A significant improvement over time was observed in age-corrected BC mortality. BC-specific-mortality was higher for men younger than 50 years. Better overall (OS) and recurrence-free survival (RFS) were observed for highly ER+ (P = 0.001), highly PR+ (P = 0.002), highly AR+ disease (P = 0.019). There was no association between OS/RFS and HER-2 status, Ki67, IHC subtypes nor grade.

Conclusions

Male BC is usually ER, PR and AR-positive, Luminal B-like/HER2-negative. Of note, 56% patients had T1 tumors but only 4% had BCS. ER was highly positive in >90% of cases but only 77% received adjuvant ET. ER, PR and AR were associated with OS and RFS, whereas grade, Ki67 and IHC surrogates were not. Significant improvement in survival over time was observed.

Abstract P6-19-01: Evaluation of multiple transcriptomic gene risk signatures in male breast cancer

Introduction: Male breast cancer (MBC) is a rare disease accounting for less than 1% of all breast cancers (BC) and 1% of all cancers in males. The clinical management is largely extrapolated from female BC. Several multigene assays are increasingly used to guide clinical treatment decisions in female BC, however there is little data on the utility of these tests in MBC.

Methods: Here we present the gene expression results of 380 M0, ER+ve, HER2-ve MBCs enrolled in the Part 1 (retrospective joint analysis) International Male Breast Cancer Program of 1483 patients diagnosed between 1990-2010 (Cardoso et al. Annals of Oncology, 2018). Using a custom Nanostring™ panel comprised of the genes from the commercial risk tests Prosigna®, OncotypeDx® and Mammaprint®, risk scores and intrinsic subtyping data were generated to recapitulate the commercial tests as described by Bayani and Yao et al (npjBreast Cancer, 2017). Survival outcomes by risk classification were analyzed using Cox models with time-dependent covariates when the proportional hazard assumption was not met and adjusted for clinical and treatment variables.

Results: Prosigna-like risk scores identified 99 (26.1%) as low-risk, 159 (41.8%) as intermediate-risk, and 122 (32.1%) as high-risk. Using the TAILORx cut-off (25) for OncotypeDx-like risk of recurrence scoring, 158 (41.6%) were identified as low-risk, while 222 (58.4%) were identified as high-risk. MammaPrint-like results identified 175 (46.1%) as low-risk and 205 (53.9%) as high-risk. Overall, patients classified as high-risk had higher grade, more nodal involvement, larger tumors, and more frequently treated with chemotherapy than low-risk patients. Survival analyses demonstrated clear clinical utility for each test, showing patients at high-risk with poor relapse-free survival (RFS) as compared to patients classified as low-risk: Prosigna-like RFS at 3-years (HR=2.20, 95% CI, 1.28-3.80); Oncotype-like RFS at 3-years (HR=1.92, 95% CI, 1.17-3.17); MammaPrint-like RFS (HR=1.51, 95% CI, 1.00-2.27); with similar findings for distant relapse-free survival (DRFS) and overall survival (OS). Across outcomes and all gene signatures, patients with concordant Low/Low risk classification had better prognosis than those with concordant High/High risk classification. PAM50 intrinsic subtyping identified 147 (38.7%) as Luminal A, 57 (15.0%) as Luminal B, 80 (21.1%) as Her2-enriched and 96 (25.3%) as Basal-like; showing overall 34.5% concordance to clinic-pathological subtyping by central pathology (95% CI, 29.7%-39.5%). Comparison between the tests in the MBC cohort and a comparable cohort of female BC from the Tamoxifen Exemestane Adjuvant Multinational (TEAM) trial processed in the same way will be presented.

Conclusion: Common transcriptomic assays designed to assess residual risk, validated in female BC, provide similar information in male BC patients. Not surprisingly, disagreement between test results at the individual patient level was observed. To our knowledge, this is the largest study of MBC assayed to generate risk scores of the current commercial BC tests to demonstrate their clinical utility and their differences and similarity to female BC.

This work has been funded by the Breast Cancer Research Foundation (BCRF).

Citation Format: Bayani J, Poncet C, Yao CQ, Crozier C, Anouk N, Piper T, Cunningham C, Sobol M, Aebi S, Benstead K, Bogler O, Dal Lago L, Fraser J, Hilbers FH, Hedenfalk I, Korde L, Linderholm B, Martens J, Middleton L, Murray M, Kelly C, Nilsson C, Nowaczyk M, Peeters S, Peric A, Porter P, Schröder C, Rubio IT, Ruddy KJ, van Asperen C, Van Den Weyngaert D, van Deurzen C, van Leeuwen-Stok E, Vermeij J, Winer E, Boutros PC, Giordano SH, Cardoso F, Bartlett JM. Evaluation of multiple transcriptomic gene risk signatures in male breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-19-01.

Abstract PD7-12: Molecular subtyping of male breast cancer by the International male breast cancer program (IMBC): EORTC 10085/TBCRC 0-29/BIG 2-07/NABCG/BOOG 2009-04

Introduction. Male breast cancer (male BC) is a rare disease for which disease management is extrapolated from females. IMBC, an international consortium, which previously reported on clinico-pathological aspects, now reports on molecular subgroups revealed by RNA sequencing and their relation to patient outcome.

Methods. Tumor samples from the retrospective MALE BC registry diagnosed between 1990-2010 and with pathology and outcome data (relapse-free- (RFS) and overall survival (OS)) were included (n=699). To allow the discovery of prognostic features, we selected, stratified for known risk factors (TN stage, grade, age at diagnose and adjuvant endocrine treatment), from the cohort 152 cases with poor (RFS &lt;= 4 yrs) and good outcome (RFS &gt; 7yrs) evenly distributed. Here, we report RNA sequencing results of the first 73 cases, 38 with poor and 35 with good outcome. RNA sequencing reads were used to generate gene expression values and to report transcripts carrying driver mutations. Unsupervised clustering identified subgroups and within subgroups differentially expressed genes were identified. The reported prognostic male BC subgroups M1 and M2 (Johansson BCR 2012(14):R31) were also annotated. All identified subgroups were related to outcome using logistic regression (p-value using Wald test).

Results. Unsupervised clustering revealed 2 main subgroups of which group 1 was enriched for expression of ER target genes, WNT3 and genes from amplicons known for female BC, e.g. 19p13 (CCNE1), 8q24 (MYC), and 11q13 (CCND1). The biology of the smaller group 2 was less defined but TGFβ2 expression was high as were various kallikreins (KLK) including interestingly KLK3 (prostate specific antigen). Other known amplified regions [(8p11 (FGFR1), 20q13 (ZNF217) and 12q15 (MDM2)] and mutated transcripts [PIK3CA (H1047R/L/Q; E542K, E545K, N345K; 16% of cases), TP53 and SF3B1 (K700E) (2% of cases)] were identified. Profound tumor infiltrate gene expression was present in 5% of cases and one third of cases expressed proliferation markers. Except for TP53, none of these latter characteristics were unevenly distributed among the 2 main subgroups. ER and AR were highly correlated, particularly in group 1. The two main groups could be further subdivided. Group 1 comprised 3 subgroups of which subgroup 1a expressed TFF1/3 and NAT1, well-known ER targets, while subgroups 1b and 1c expressed other ER targets,respectively BEX1 and PITX1. HOXC cluster expression differentiated subgroup 1b from 1a and 1c. None of these intrinsic subgroups were, however, related to RFS. The previously reported M2 subgroup, which largely segregated with subclusters 1a and 1b, was associated with a better RFS than the M1 subgroup (OR=2.9; 95%CI 1.1-7.5; p-value=0.03).

Conclusions. 1) Intrinsic subtypes of male BC were revealed and their subgrouping is defined by ER associated subsets of genes. 2) The association of the reported M2 subgroup of male BC with longer RFS was validated; 3) Currently identified biological characteristics of male BC may improve future treatments. The full report on 152 cases including a comparison to female BC will be presented at the conference.

This research was funded by Breast Cancer Research Foundation

Citation Format: Martens JWM, Sieuwerts A, Ponchet C, Smid M, de Weerd V, Slaets L, Piper T, van Deurzen CHM, Schroder CP, Stangle C, Kloosterman W, van Leeuwen-Stok E, Nilsson C, Vermeij J, Peeters S, Goulioti T, Nowaczyk M, Aebi S, Rubio IT, Kelly C, Bayani J, Porter P, Murray M, Hudis C, Middleton L, Korde L, Ruddy K, Winer E, Bogler O, van den Weyngaert D, dal Lago L, Fraser J, Benstead K, van Asperen C, Linderholm B, Hedenfalk I, Tryfonidis K, Giordano S, Bartlett J, Cardoso F. Molecular subtyping of male breast cancer by the International male breast cancer program (IMBC): EORTC 10085/TBCRC 0-29/BIG 2-07/NABCG/BOOG 2009-04 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD7-12.

Association of MYH9 rs3752462 and rs5756168 Polymorphisms With Transplanted Kidney Artery Stenosis

Allelic variants of the MYH9 gene, encoding myosin nonmuscle heavy chain type IIA, have been shown to correlate with diminished glomerular filtration rates and end-stage kidney disease in individuals of Caucasian ancestry. Myosin nonmuscle heavy chain type IIA is expressed during development as well as in injured vessels and kidney structures. We hypothesized that MYH9 risk variants may correlate with kidney artery injury and dysfunctional healing, such as transplant renal artery stenosis (TRAS). Our study aimed at evaluating the association of MYH9 risk allelic variants (rs4821480, rs4821481, rs3752462, rs11089788, rs136211, rs5756168, rs2032487, and rs2239784) with TRAS, defined as >50% renal artery lumen reduction. Genotyping was performed with the use of custom Taqman genotyping assays on DNA samples (n = 295) from white deceased-donor kidney transplant recipients and genomic DNA from the corresponding donors. Statistical analysis was performed with the use of Kaplan-Meier estimates, log-rank tests, and proportional hazard Cox models. Recipients carrying TT in rs5756168 experienced diminished risk of TRAS (hazard ratio [HR], 0.31; P < .009), whereas organs carrying CC in rs3752462 were exposed to excessive TRAS risk (HR, 2.54; P < .047). In multivariate stepwise analysis TRAS was 10.9-fold increased in kidneys originating from rs3752462 CC, whereas the risk was decreased 3.45-fold (adjusted HR, 0.29) in recipients carrying rs5756168 TT (P < .007 and P < .033, respectively). Intracranial bleeding or trauma compared with other mechanisms of donor death diminished TRAS risk by 87% and 91%, respectively (P < .030 and P < .017). Our study is the first to identify genetic predisposition to transplant renal artery stenosis.

Charge separation, stabilization, and protein relaxation in photosystem II core particles with closed reaction center

The fluorescence kinetics of cyanobacterial photosystem II (PSII) core particles with closed reaction centers (RCs) were studied with picosecond resolution. The data are modeled in terms of electron transfer (ET) and associated protein conformational relaxation processes, resolving four different radical pair (RP) states. The target analyses reveal the importance of protein relaxation steps in the ET chain for the functioning of PSII. We also tested previously published data on cyanobacterial PSII with open RCs using models that involved protein relaxation steps as suggested by our data on closed RCs. The rationale for this reanalysis is that at least one short-lived component could not be described in the previous simpler models. This new analysis supports the involvement of a protein relaxation step for open RCs as well. In this model the rate of ET from reduced pheophytin to the primary quinone Q(A) is determined to be 4.1 ns(-1). The rate of initial charge separation is slowed down substantially from approximately 170 ns(-1) in PSII with open RCs to 56 ns(-1) upon reduction of Q(A). However, the free-energy drop of the first RP is not changed substantially between the two RC redox states. The currently assumed mechanistic model, assuming the same early RP intermediates in both states of RC, is inconsistent with the presented energetics of the RPs. Additionally, a comparison between PSII with closed RCs in isolated cores and in intact cells reveals slightly different relaxation kinetics, with a approximately 3.7 ns component present only in isolated cores.

Clinical, enzymatic and molecular characterization of nine new patients with malonyl-coenzyme A decarboxylase deficiency

We report nine new patients with malonic aciduria associated with enzyme-confirmed malonyl-CoA decarboxylase (MCD) deficiency in eight. Clinical details were available on eight, and molecular genetic characterization was obtained for nine. As for 15 previously described patients, cardinal clinical manifestations included developmental delay and cardiomyopathy; metabolic perturbations (e.g. acidosis) and seizures, however, were infrequent or not observed in our patients. For all, detection of elevated malonic acid in urine (+/- increased C3DC acylcarnitine by analysis employing tandem mass spectrometry) led to pursuit of enzyme studies. MCD activities (nmol/h PER mg protein) revealed: control (n = 22), 16.2 +/- 1.8 (SEM; range 5.7-46.2); patients (n = 8, assayed in duplicate), 1.7 +/- 0.3 (10% of parallel control; range 0.6-2.8). Molecular characterization by DNA sequence analysis and multiplex ligation-dependent probe amplification revealed nine novel mutations (c.796C>T; p.Gln266X, c.481delC; p.Leu161CysfsX18, c.1367A>C; p.Tyr456Ser, c.1319G>T; p.Ser440Ile, c.1430C>T; p.Ser477Phe, c.899G>T; p.Gly300Val, c.799-1683_949-1293del3128, and two other large genomic deletions comprising exons 1 or the complete gene) and two known mutations in the MLYCD gene. Our findings increase the number of enzyme-confirmed MCD-deficient patients by >50%, and expand our understanding of the phenotypic and molecular heterogeneity of this rare disorder.

Survival of 231 cervical cancer patients, treated by radical hysterectomy, according to clinical and histopathological features

PURPOSE OF INVESTIGATION

The purpose of the study was to estimate the five-year survival of cervical cancer patients after radical hysterectomy, taking into account clinical data and histopathological parameters.

METHODS

231 patients with invasive cervical carcinoma were diagnosed, surgically treated--Piver III--and followed-up. Histological examination of specimens was performed according to the British NHS-CSP guidelines.

RESULTS

We discovered no statistical significance as regards age at diagnosis, age at menarche and menopause, and number of pregnancies, deliveries and abortions, in relation to survival. We concluded that the clinical stage according to FIGO classification influenced survival. Statistical significances were: Ia2 vs Ib, Ib vs IIa and IIa vs more advanced than IIa. The following histopathological parameters correlated with survival: depth of cervical invasion, primary lesion volume, and parametrial, uterine, vaginal and lymph node involvement. Using Cox's proportional hazards model we found that only lymph node status and FIGO staging were independent parameters correlating with survival and mortality risk in our study.

CONCLUSION

Prognostic indexes classifying patients at specific disease stages into different categories of risk should be based on histopathological features listed above. Such indexes are yet to be validated in larger, prospective studies conducted in different patient populations.

Bacteriophages and transplantation tolerance

Our recent findings suggest that bacteriophages (phages) may not only eliminate bacteria, but also modulate immune functions. In this communication, we demonstrate that phages may strongly inhibit human T-cell activation and proliferation as well as activation of the nuclear transcription factor NF-kappaB in response to a viral pathogen. Phage administration in vivo can diminish cellular infiltration of allogeneic skin allografts. Thus, phage treatment should be considered in antibiotic-resistant posttransplantation infections. Furthermore, phages could find a broader application in clinical transplantation.

Beta 3 integrin expression on T cells from renal allograft recipients

Recent studies emphasize the paramount significance of beta 3 integrin in cell adhesion and homing, which may be particularly relevant in cancer progression and metastasis. In contrast, the presence and potential role of beta 3 on human T cells is practically unknown. We show that T cells can express significant amounts of alpha-beta 3 integrin (CD41/CD61), and the expression of alpha(v)-beta 3 (CD51/CD61) remains very low. T-cell beta 3 integrin is probably transferred by platelet-derived microparticles.

Kinetics and mechanism of electron transfer in intact photosystem II and in the isolated reaction center: pheophytin is the primary electron acceptor

The mechanism and kinetics of electron transfer in isolated D1/D2-cyt(b559) photosystem (PS) II reaction centers (RCs) and in intact PSII cores have been studied by femtosecond transient absorption and kinetic compartment modeling. For intact PSII, a component of approximately 1.5 ps reflects the dominant energy-trapping kinetics from the antenna by the RC. A 5.5-ps component reflects the apparent lifetime of primary charge separation, which is faster by a factor of 8-12 than assumed so far. The 35-ps component represents the apparent lifetime of formation of a secondary radical pair, and the approximately 200-ps component represents the electron transfer to the Q(A) acceptor. In isolated RCs, the apparent lifetimes of primary and secondary charge separation are approximately 3 and 11 ps, respectively. It is shown (i) that pheophytin is reduced in the first step, and (ii) that the rate constants of electron transfer in the RC are identical for PSII cores and for isolated RCs. We interpret the first electron transfer step as electron donation from the primary electron donor Chl(acc D1). Thus, this mechanism, suggested earlier for isolated RCs at cryogenic temperatures, is also operative in intact PSII cores and in isolated RCs at ambient temperature. The effective rate constant of primary electron transfer from the equilibrated RC* excited state is 170-180 ns(-1), and the rate constant of secondary electron transfer is 120-130 ns(-1).

Charge Separation Kinetics in Intact Photosystem II Core Particles Is Trap-Limited. A Picosecond Fluorescence Study

The fluorescence kinetics in intact photosystem II core particles from the cyanobacterium Thermosynechococcus elongatus have been measured with picosecond resolution at room temperature in open reaction centers. At least two new lifetime components of approximately 2 and 9 ps have been resolved in the kinetics by global analysis in addition to several known longer-lived components (from 42 ps to approximately 2 ns). Kinetic compartment modeling yields a kinetic description in full agreement with the one found recently by femtosecond transient absorption spectroscopy [Holzwarth et al. (2005) submitted to Proc. Natl. Acad. Sci. U.S.A.]. We have for the first time resolved directly the fluorescence spectrum and the kinetics of the equilibrated excited reaction center in intact photosystem II and have found two early radical pairs before the electron is transferred to the quinone Q(A). The apparent lifetime for primary charge separation is 7 ps, that is, by a factor of 8-12 faster than assumed on the basis of earlier analyses. The main component of excited-state decay is 42 ps. The effective primary charge separation rate constant is 170 ns(-)(1), and the secondary electron-transfer rate constant is 112 ns(-)(1). Both electron-transfer steps are reversible. Electron transfer from pheophytin to Q(A) occurs with an apparent overall lifetime of 350 ps. The energy equilibration between the CP43/CP47 antenna and the reaction center occurs with a main apparent lifetime of approximately 1.5 ps and a minor 10 ps lifetime component. Analysis of the overall trapping kinetics based on the theory of energy migration and trapping on lattices shows that the charge separation kinetics in photosystem II is extremely trap-limited and not diffusion-to-the-trap-limited as claimed in several recent papers. These findings support the validity of the assumptions made in deriving the earlier exciton radical pair equilibrium model [Schatz, G. H., Brock, H., and Holzwarth, A. R. (1988) Biophys. J. 54, 397-405].

New insights into the possible role of bacteriophages in transplantation

Due to the increasing prevalence of drug-resistant bacterial infections in the "post-antibiotic era," bacteriophages (bacterial viruses, BP) may be useful to administer to transplant recipients without exposing them to an increased risk of rejection, which occurs consequent to some viral infections. Herein we present evidence that at least some coliphages (T4) do not pose such risk. Interestingly, they may produce immunosuppressive effects extending transplant survival. Our data suggest that BP may be used in clinical transplantation to treat drug-resistant bacterial infections and perhaps as an adjunct to immunosuppressive therapy.

Antitumor activity of bacteriophages in murine experimental cancer models caused possibly by inhibition of beta3 integrin signaling pathway

Bacteriophages (phages) as bacterial viruses are generally believed to have no intrinsic tropism for mammalian cells. In this study the interactions between phages and various eukaryotic cells were investigated. Binding of phages to the membranes of cancer and normal blood cells was observed. Moreover, it was shown that the wild-type phage T4 (wtT4) and its substrain HAP1 with enhanced affinity for melanoma cells inhibit markedly and significantly experimental lung metastasis of murine B16 melanoma cells by 47% and 80%, respectively. A possible molecular mechanism of these effects, namely a specific interaction between the Lys-Gly-Asp motif of the phage protein 24 and beta3-integrin receptors on target cells is proposed. It was also shown that anti-beta3 antibodies and synthetic peptides mimicking natural beta3 ligands inhibit the phage binding to cancer cells. This is in line with the well-described beta3 integrin-dependent mechanism of tumor metastasis. It is concluded that the blocking of beta3 integrins by phage preparations results in a significant decrease in tumor invasiveness.

The biological functions of beta3 integrins

Integrins comprise a large family of alphabeta heterodimeric cell-surface receptors that are found in many animal species. They are expressed on a wide variety of cells. There are two members in the beta3 integrin family: alphaIIb beta3 and alpha(v)beta3. This class of adhesion receptors mediates cell-cell and cell-extracellular matrix interactions. Dysregulation of the beta3 integrins is involved in the pathogenesis of many diseases (including cancer) and in transplant rejection. Integrins also play a key role in many virus infectious cycles. In this paper the biological functions of the beta3 family are reviewed, with particular interest in its role in cancer progression and metastasis.

[Adhesion of human granulocytes and T lymphocytes to vascular endothelial cells after stimulation with Bacteroides fragilis endotoxin and enterotoxin]

The aim of presented study was to estimates the number of human granulocytes and T lymphocytes adhering to 1 mm2 of vascular endothelial cell culture stimulated by Bacteroides fragilis endotoxins (LPS) and enterotoxin (BFT). HMEC-1 cells were activated with bacterial preparations at the concentration of 10 (micrograms/ml for 4 and 24 hours. Granulocytes and T lymphocytes were isolated from peripheral blood of healthy blood donors. The adhesion tests of granulocytes and adhesion tests of resting and activated with PMA (at the concentration of 10 ng/ml) T lymphocytes to the non-stimulated and stimulated by B. fragilis compounds (LPS and BFT) vascular endothelium were performed. The number of viable leukocytes, which adhered to the endothelium, was determined using inverted microscope (magnification 200x). The results were presented as the number of viable cells adhering to 1 mm2 of the endothelial cell culture. The results of experiments indicate that granulocytes and T lymphocytes (resting and after activation with PMA even in greater number) adhere to the endothelial cells stimulated by B. fragilis endotoxins and enterotoxin. B. fragilis toxins are weaker stimulants of human leukocyte adhesion to the HMEC-1 cells than E. coli O55:B5 LPS. B. fragilis LPS and BFT preparations stimulate endothelial cells to the adhesion of granulocytes in similar manner, whereas the activation of vascular endothelium to the adhesion of T lymphocytes is differentiated.

[The effect of metronidazole on stimulation of adhesion molecule expression on the surface of vascular endothelial cells by Bacteroides fragilis endotoxins and enterotoxin]

The influence of metronidazole on the level of expression of adhesion molecules ICAM-1, VCAM-1 and E-selectin on the surface of vascular endothelial cells activated with B. fragilis endotoxins and enterotoxin was examined. Three enterotoxigenic (ETBF) strains and one nonenterotoxigenic (NTBF) strain were used for lipopolysaccharide extraction. Enterotoxin was prepared from the culture supernatant of the reference B. fragilis ATCC 43858 strain. Expression of adhesion molecules on vascular endothelial cells (HMEC-1 cell line) was determined after their stimulation with bacterial compounds at the concentration of 10 micrograms/ml in the presence of metronidazole at the concentration of 4 micrograms/ml. Endothelial cells were activated for 4 hours (E-selectin expression) and for 24 hours (ICAM-1 and VCAM-1 expression). Adhesion molecules were detected in immunoenzymatic test (ELISA) with mouse, monoclonal antibodies against human ICAM-1, VCAM-1 and E-selectin. The results of experiments suggest, that metronidazole enhances the expression of examined adhesion molecules on endothelial cells. This antimicrobial agent causes some changes in the expression of endothelial ICAM-1, VCAM-1 and E-selectin stimulated by B. fragilis endotoxins and enterotoxin.

[Effect of clindamycin on stimulation of cell adhesion molecules by endotoxins and enterotoxin of Bacteroides fragilis strains]

The influence of clindamycin on expression of B. fragilis endotoxins (LPS) and enterotoxin stimulated cell adhesion molecules: ICAM-1, VCAM-1 and E-selectin on HMEC-1 (human microvascular endothelial cell line) was tested. Lipopolysaccharides from four Bacteroides fragilis strains: one nonenterotoxigenic (NTBF) and three enterotoxigenic (ETBF) were extracted by hot phenol-water method and purified. B. fragilis enterotoxin was prepared according to the method described by van Tassel et al. (1992). All bacterial preparations were used for stimulation at concentration 10 micrograms/ml. Clindamycin was used in concentration of 2 micrograms/ml. The influence of antimicrobial agent on the endotoxins and enterotoxin stimulation and expression of adhesion molecules was tested by ELISA, using monoclonal mouse anti-human antibodies (Genzyme, USA). Peroxidase-conjugated rabbit anti-mouse immunoglobulins (DAKO A/S Denmark) and OPD (Sigma USA) were used. The coloured reaction product was measured by reading the absorbance at 492 nm in SPECTRA II reader (SLT, Austria). It was observed that clindamycin influenced the expression of cell adhesion molecules on resting cell line. HMEC-1 cells stimulated with Bacteroides fragilis LPS preparations have suppressive effect on ICAM-1 expression. ICAM-1 expression was augmented when stimulated with Tox 1 and Tox 2 preparations. Clindamycin augmented the VCAM-1 expression in tests with all bacterial preparations. All used bacterial preparations of Bacteroides fragilis LPS and enterotoxin enhanced the expression of E-selectin with exception of LPS of NTBF strain.

Ethanol facilitation of short-term memory in adult rats with a disturbed circadian cycle

The aim of this study was to evaluate the effect of 3-month ethanol treatment on olfactory social memory test performance using two inter-exposure intervals [30 min: short-term recognition (STR); or 120 min: long-term recognition (LTR)] in adult rats with a disturbed circadian cycle (DCC). Ethanol treatment both in ethanol-preferring and -non-preferring groups improved the STR task compared to control rats. However, LTR procedure triggered the opposite tendency. Moreover, no differences between control rats with DCC and those with normal diurnal rhythm in STR and LTR paradigms were observed. Our results suggest that, under some conditions, alcohol facilitates short-term memory in adult rats.

[Adhesion of human T lymphocytes and granulocytes to endothelial cells stimulated by cell-surface antigens of Bacteroides thetaiotaomicron]

The aim of this study was to assay the degree of human T lymphocyte and granulocyte adhesion to the vascular endothelial cells stimulated by Bacteroides thetaiotaomicron lipopolysaccharides, components of LPS and capsular polysaccharide. HMEC-1 cells were activated with bacterial preparations in concentration 10 micrograms/ml for 4 and 24 hours. T lymphocytes and granulocytes were isolated from peripheral blood of healthy blood donors. Thereafter, the adhesion tests of granulocytes and adhesion tests of non-activated and activated with PMA (in concentration 10 ng/ml) T lymphocytes to the resting and stimulated vascular endothelium were performed. The number of viable cells, which adhered to the endothelium, was determined using inverted microscope (magnification 200x). The results were presented as the number of viable cells adhering to 1 mm2 of the endothelial cell culture. The obtained results indicate that granulocytes and T lymphocytes (resting and activated with PMA) adhere to the endothelial cells stimulated by B. thetaiotaomicron cell-surface antigens. B. thetaiotaomicron lipopolysaccharides and capsular polysaccharide are weaker stimulants of human leukocyte adhesion to the HMEC-1 cells than E. coli O55:B5 LPS.

Treatment of chronic hepatitis B and C with interferon-alpha in renal allograft recipients: preliminary results

We evaluated the effects of treatment with interferon (IFN) on liver disease and renal allograft function in ten immunosuppressed cadaver kidney recipients. Two females and eight males (mean age 39 years) with biopsy-proven chronic active hepatitis (n = 8) or persistent hepatitis (n = 2) and serum positive for hepatitis B surface antigen (HBsAg) and HBe antigen (n = 5) or serum positive for anti-HCV antibodies (n = 3) or serum positive for HBsAg, anti-HCV and anti-HDV antibodies (n = 2) received 3 million units IFN thrice weekly of 6 months. All patients responded with a reduction in serum aminotransferase activity and in five of them liver function completely normalized. Three patients among five infected with HBV cleared HBeAg. During the follow-up period liver function remained stable in 9 patients after discontinuation of IFN therapy. Three patients lost their grafts due to rejection 1, 2, and 4 months after IFN therapy, respectively. In six patients renal function remained stable during and after IFN therapy. We conclude that in selected groups of renal allograft recipients IFN can be used safely and effectively for the treatment of chronic viral hepatitis.

[Stimulation of adhesion molecules on vascular endothelium by capsular polysaccharide, lipopolysaccharide and components of lipopolysaccharide from Bacteroides thetaiotaomicron]

The aim of this study was to assay the influence of capsular polysaccharide (CPS), lipopolysaccharide (LPS) and components of B. thetaiotaomicron lipopolysaccharide--polysaccharide part (PS) and lipid part (lipid A) on the expression of adhesion molecules associated with inflammation (ICAM-1, VCAM-1, E-selectin) on the surface of vascular endothelial cells. Capsular polysaccharide was isolated by the method of Poxton and Ip (1981). Lipopolysaccharides were extracted using the hot phenol-water method (Westphal and Jann, 1965). Components of LPS were prepared by mild acid hydrolysis of lipopolysaccharide. Experiments with bacterial compounds at concentrations 10, 1, 0.1 and 0.01 (mg/ml) were performed on HMEC-1 cell line (human dermal microvascular endothelial cells). Immunoenzymatic ELISA test with mouse monoclonal antibodies against human: ICAM-1, VCAM-1 and E-selectin was applied to determine adhesion molecules. Resting HMEC-1 and E. coli O55:B5 LPS were used as controls in each experiment. Lipopolysaccharides were the strongest stimulants of endothelial adhesion molecules. Capsular polysaccharide caused the expression of three adhesion molecules, but only at the highest concentration (10 mg/ml). The stimulatory activities of LPS lipid components were much higher than the activities of polysaccharide parts. PS preparations did not reveal the property of adhesion molecule stimulation or their activities were weak. The activity of B. thetaiotaomicron cell-surface antigens in the process of adhesion molecule stimulation on vascular endothelium was lower than the activity of E. coli LPS.

[Toxins of Bacteroides fragilis and Bacteroides thetaiotaomicron rods as stimulators of adhesion molecule expression on the surface of vascular endothelial cells]

Lipopolysaccharides from four Bacteroides fragilis strains: one nonenterotoxigenic (NTBF) and three enterotoxigenic (ETBF), and from three B. thetaiotaomicron strains were extracted by hot phenol-water method and purified. B. fragilis enterotoxin was prepared according to the procedure of van Tassell et al. (1992). The influence of the examined toxins on the expression of adhesion molecules: ICAM-1, VCAM-1 and E-selectin on HMEC-1 (human dermal microvascular endothelial cells) was assayed in ELISA test with monoclonal antibodies. Four concentrations of toxins were applied: 0.01, 0.1, 1.0 and 10.0 (micrograms/ml). Endothelial cells were activated for 24 hours (ICAM-1 and VCAM-1 expression) and for 4 hours (E-selectin expression). The coloured product of immunoenzymatic reaction was measured by reading the absorbance at wavelength 492 nm. Two controls were performed in each experiment: with resting HMEC-1 and E. coli O55:B5 LPS (Sigma, USA). Bacteroides fragilis and B. thetaiotaomicron lipopolysaccharides stimulated three adhesion molecules under investigation. Their activity was comparable, but weaker than the activity of E. coli O55:B5 LPS. ICAM-1 was the most stimulated molecule. B. fragilis enterotoxin induced two adhesion molecules: VCAM-1 and E-selectin demonstrating weaker stimulatory activity than E. coli LPS. Stimulation of adhesion molecules on vascular endothelial cells should be considered to be a biological activity of B. fragilis and B. thetaiotaomicron endotoxins and B. fragilis enterotoxin.

Second lower genital tract squamous cell carcinoma following cervical cancer. A clinical study of 46 patients

BACKGROUND

Patients after treatment for cervical cancer have increased risk of developing second squamous cell malignancy of the lower genital tract.

MATERIAL AND METHODS

A retrospective study of 46 patients with second lower genital tract epidermoid cancers following previous treatment for invasive cervical carcinoma.

RESULTS

Patient age at diagnosis of cervical cancer was 27 to 68 years (median 44 years) and at diagnosis of the second malignancy - 43 to 72 years (median 63 years). There were four cases (9%) of synchronous cancers. Time span between metachronous malignancies ranged from 66 to 406 months (median 206 months). In 32 cases (70%) second lesion was located in the vagina and in 14 (30%) - in the vulva. Out of 35 previously irradiated patients, in 24 (69%) second tumor was located within the high dose volume and in 11 (31%) - outside it. Treatment of second cancer consisted of surgery in 12 patients (26%), radiotherapy in 23 (50%), combined surgery and radiotherapy--in five (11%), chemotherapy in four (9%) and surgery plus chemotherapy - in one case. Median survival was 52 months and five-year survival from the diagnosis of second malignancy - 47.5%. No prognostic factors for survival were identified.

CONCLUSION

Treatment outcome in patients with second lower genital tract carcinoma is unsatisfactory due to poor feasibility of another definite treatment after previous radical surgery and/or radiotherapy.

Role of adhesion molecules in chronic allograft rejection

Endothelial adhesion molecules play an important role in T cell recruitment to an allograft site. Therefore, it could be expected that their blocking may be beneficial for allograft survival. In this report, we show that T cells from patients with chronic rejection have an up-regulated ability to adhere to inflamed endothelium in vitro. Furthermore, this enhanced T cell: endothelial interaction could be blocked by anti-VCAM and anti-E-selectin monoclonal antibodies.

Adhesion molecule expression stimulated by Bacteroides thetaiotaomicron cell-surface antigens

Bacteroides thetaiotaomicron, a Gram-negative anaerobic rod belonging to the Bacteroides fragilis group (BFG), is involved in many systemic and local, most frequently suppurative infections in man. The cell envelope of these rods is composed of two carbohydrate-containing antigens: lipopolysaccharide (LPS) and capsular polysaccharide (CPS). Adhesion molecules ICAM-1, VCAM-1 and E-selectin (ELAM-1) are induced on the endothelial cells by mediators of inflammation. The aim of this study was to assay the ability of B. thetaiotaomicron surface antigens to induce adhesion molecule expression on the endothelial cells. The influence of LPS and CPS on the expression of adhesion molecules on HMEC-1 cell line was examined in an ELISA test. ELISA was performed with monoclonal mouse anti-human: ICAM-1, VCAM-1 and E-selectin antibodies of the IgG class. B. thetaiotaomicron lipopolysaccharides revealed the ability to induce ICAM-1, VCAM-1 and E-selectin expression on the endothelial cells. Their activities were similar, but lower than the activity of Eschericha coli LPS. ICAM-1 was the most stimulated adhesion molecule. The strongest activation by LPS was achieved at the concentrations of 10.0 and 1.0 micrograms/ml. The ability of capsular polysaccharide to induce the expression of adhesion molecules was considerably weaker.

Lymphocyte interactions with extracellular matrix proteins and endothelium in renal allograft recipients

Recent data indicate that extracellular matrix (ECM) proteins can provide costimulatory signals during the process of T cell activation. Those proteins accumulate in situ during allograft rejection; therefore, it may be expected that local ECM: T cell interactions may be relevant in the immunopathology of rejection. T cell adhesion from allograft of recipients with stable renal function (RAR-S) and patients with biopsy-proven chronic rejection (RAR-CH) to ECM proteins (collagen type IV, fibronectin, elastin) was measured. Furthermore, T cell: endothelial interactions in vitro were studied. Adhesion of PHA-activated T cells from both groups of allograft recipients to fibronectin, collagen type IV and elastin was significantly lower than in healthy blood donors. Moreover, similar pattern of activity was observed when T cell attachment to resting and activated endothelium was studied. There were no significant differences in the number of circulating CD45RO and CD4 positive T cells. We observed a higher (although not significantly) adhesion of the T cells to resting human dermal microvascular endothelial cells (HMEC) in the chronic stages of rejection, which can suggest that the immunosuppressive protocol used in the treatment of chronic rejection is insufficient to control immunopathologic phenomena occurring in that process. Therefore, it may be argued that too low immunosuppression can be one of the factors responsible for the development of this complication.

Abnormalities in T cell interactions with the extracellular matrix proteins in a patient with Wegener's granulomatosis

T cell interactions with the extracellular matrix proteins and cultured human endothelium were studied in a patient with Wegener's granulomatosis and other cases of vasculitis. Markedly enhanced costimulation of T-lymphoproliferative responses mediated by collagen and fibronectin were found in patients with severe forms of vasculitis, particularly with necrotizing changes. In addition, enhanced adhesion to collagen IV was found in the Wegener patient. T cell adhesion to resting and inflamed endothelium varied from normal to increased.