Cardiovascular risk factors: The effects of ageing and smoking on the immune system, an observational clinical study

Currently immunomodulatory compounds are under investigation for use in patients with cardiovascular disease, caused by atherosclerosis. These trials, using recurrent cardiovascular events as endpoint, require enrollment of large patient groups. We investigated the effect of key risk factors for atherosclerosis development, ageing and smoking, on the immune system, with the objective to identify biomarkers differentiating between human populations, and potentially serving as endpoints for future phase 1B trials with immunomodulatory compounds. Blood was collected from young healthy volunteers (aged 18-25 years, n=30), young smokers (18-25 years, n=20), elderly healthy volunteers (>60 years, n=20), heavy smokers (>45 years, 15 packyears, n=11) and patients with stable coronary artery disease (CAD) (>60 years, n=27). Circulating immune cell subsets were characterized by flow cytometry, and collected plasma was evaluated by proteomics (Olink). Clear ageing effects were observed, mostly illustrated by a lower level in CD8⁺ and naïve CD4⁺ and CD8⁺ T cells, with an increase in CD4⁺ and CD8⁺ effector memory T cells in elderly healthy volunteers compared to young healthy volunteers. Heavy smokers showed a more inflammatory cellular phenotype, especially a shift in Th1/Th2 ratio: higher Th1 and lower Th2 percentages compared to young healthy volunteers. A significant decrease in circulating atheroprotective oxLDL-specific IgM was found in patients with CAD compared to young healthy volunteers. Elevated pro-inflammatory and chemotactic proteins TREM1 and CCL11 were observed in elderly volunteers compared to young volunteers. In addition, heavy smokers had an increase in pro-inflammatory cytokine IL-6 and lysosomal protein LAMP3. These data show that ageing and smoking are associated with an inflammatory immunophenotype, and that heavy smokers or aged individuals may serve as potential populations for future clinical trials investigating immunomodulatory drugs targeted for cardiovascular disease.

B cell depletion skews cd4+ t cell towards a pro-inflammatory phenotype in aged atherosclerotic mice

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation

ERA CVD

Aims

Aging is associated with changes in the composition and function of the immune system, such as decreased B cell numbers and reduced antibody responses (1). In addition, aging is related to an increased incidence of inflammatory diseases, such as the lipid-driven chronic inflammatory disease atherosclerosis, the main underlying cause of cardiovascular disease (2). B cells play a major role in atherosclerosis progression by antibody secretion, antigen presentation and T cell regulation. Different B cell subsets, with either proatherogenic or antiatherogenic properties, have been identified in atherosclerosis, but the impact of aging on B cells during atherosclerosis remains to be elucidated. In contrast to young atherosclerotic mice where few B cells are found within the plaque, single cell RNA sequencing and flow cytometry data from our group revealed that B cells are one of the most dominant leukocytes present in atherosclerotic aortas from naturally aged LDLr-/- mice. In this study, we aimed to gain further insights into the role of these aged B cells on T cell immunity in atherosclerosis by depleting B cells in aged atherosclerotic mice.

Methods and Results

Aged (85-95 weeks) atherosclerotic male LDLr-/- mice were kept on a chow diet for six weeks, during which the mice received 250 µg B cell-depleting anti-CD20 antibody (Genentech) (n=12) or 250 µg rat IgG2a isotype control (n=12) once a week intraperitoneally. Mice that received the anti-CD20 antibody showed effective B cell depletion in the blood and lymphoid organs, such as the spleen and lymph nodes, but also locally in the atherosclerotic plaque. In addition, B cell depleted mice showed a significant increase in the percentage of T-bet expressing CD4+ T cells in aortic plaques compared to control mice (αCD20: 25.05±2.88% vs. ctrl: 15.94±2.14%, p<0.05). Furthermore, the percentage of RORyt+ and IL-17+ CD4+ T cells in the spleen and heart draining lymph nodes was increased after B cell depletion, indicating a shift towards Th17 differentiation.

Conclusions

Collectively, we show that CD20+ B cell depletion in aged LDLr-/- mice skews CD4+ T cells towards a Th1 phenotype in the atherosclerotic plaque and towards a Th17 phenotype in lymphoid organs, suggesting a protective role for aged B cells in atherosclerosis. However, B cells are a heterogeneous population and further research should elucidate whether aged B cells exert a pro- or anti-atherogenic role. In conclusion, our results indicate that aged B cells have an important function in CD4+ T cell differentiation and could be attractive targets to combat age-related cardiovascular disease.

Granzyme B+ CD4+ T cells associate with an unstable plaque phenotype in advanced human atherosclerosis

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): The Dutch Heart Foundation

Cytotoxic CD4+ T cells have previously been found in peripheral blood of patients with coronary artery disease (1), however their occurrence in atherosclerotic plaques and their association with the pathophysiology of atherosclerosis has not been established.

Single-cell RNA sequencing was performed on human carotid atherosclerotic plaques of 18 patients to identify specific T cell populations (2). Next, human femoral and carotid atherosclerotic plaques (n=95) and matched blood samples (n=49) were analyzed by flow cytometry for the presence of CD4+GZMB+ T cells. Plaque morphology was assessed by Movat’s Pentachrome staining.

A distinct cytotoxic GZMB+ PRF1+ CD28- CD4+ T cell cluster was identified using single-cell RNA sequencing. Furthermore, flow cytometry analysis showed that the percentage of GZMB+CD4+ T cells was significantly elevated in plaque compared to blood (Blood: 12.17±2.0 vs. Plaque: 17.40±1.0; P=0.0002). Moreover, a significant positive correlation was observed between the percentage of GZMB+CD4+ T cells in blood versus plaque (P=0.031). In line with the proinflammatory character of these cells, we found a positive association of GZMB+CD4+ T cells (P=0.036) with necrotic core size, whereas no correlation was found with this subtype in the circulation.

In this study we have shown an enrichment of cytotoxic CD4+ T cells in atherosclerotic lesions, which positively correlate with necrotic core size. Future studies are aimed at elucidating the role of these cells in advanced atherosclerosis.

Abstract P6-01-01: Immunohistochemical staining and in vitro analysis of HER2-positive breast cancer using trastuzumab and pertuzumab to develop an appropriate tracer in image-guided surgery

Background: Pre- and intraoperative visualization of cancer cells using monoclonal antibody-based multimodal tracers can demarcate tumor margins in breast-conserving surgery. We focused on trastuzumab (Tmab) to develop a tracer for HER2-positive breast cancer by conjugation with a fluorescent dye. However, whether Tmab can be used as an imaging tracer for patients who receive Tmab as neoadjuvant therapy (NAD) is unclear, because tumor-cell HER2 could be bound by NAD Tmab at the time of surgery. This study evaluated immunohistochemical (IHC) staining and in vitro experiments with Tmab and pertuzumab (Pmab) as primary antibodies to find a suitable tracer. Pmab has a different antigen epitope than Tmab.

Methods: We included 43 patients with HER2-positive breast cancer, who were treated between 2010 and 2016. The NAD cohort (n=10, with 26 lesions) received chemotherapy and Tmab before surgery. The Tmab-naïve cohort (n=33, with 95 lesions) did not receive chemotherapy or Tmab before surgery. We excluded NAD patients with pathological complete responses. We evaluated the lesions, using IHC with Tmab and Pmab. We also performed flow cytometry and fluorescent microscopic analysis (FMA) using Tmab and Pmab conjugated with a fluorescent agent for the HER2-negative MCF7 and HER2-positive HCC1954 cell lines, which were pre-treated with Tmab to model NAD conditions.

Results: IHC with anti-HER2 antibody showed positive staining in all patients. Tmab staining was less intense, but positive Tmab IHC reactions were detected on tumor cell membranes in 77.8% of lesions in the naïve cohort and 70.8% in the NAD cohort. Pmab staining was seen in 46.3% of naïve cohort lesions and 22.2% of NAD lesions. Notably, we observed cytoplasmic staining in 87.8% of Pmab-negative cases in the NAD cohort. Flow cytometry showed less Tmab binding than Pmab binding in HCC1954 cells. After 24 hours' pretreatment incubation with Tmab, FMA showed a clear decrease in Tmab binding from 73.3% (without pretreatment) to 5.7%(after pretreatment), and a smaller decrease in Pmab binding from 72.7% (without pretreatment) to 66.4% (after pretreatment) in HCC1954 cells.

Conclusions:Pmab might be a suitable tracer for image-guided surgery after NAD, but identifying a suitable tracer for HER2-positive breast cancer will require further study.

Citation Format: Otsubo R, Kuppen PJ, Bhairosingh S, Vahrmeijer AL, Smit VT, Nagayasu T, van de Velde CJ, Sier CF. Immunohistochemical staining and in vitro analysis of HER2-positive breast cancer using trastuzumab and pertuzumab to develop an appropriate tracer in image-guided surgery [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 P6-01-01.

Abstract P1-15-20: DIetary REstriction as an adjunct to neoadjuvant ChemoTherapy for HER2-negative breast cancer: Final results from the DIRECT trial (BOOG 2013-04)

Background:

Short term fasting (STF) protects from toxicity, while enhancing the efficacy of chemotherapy in cancer bearing mice and is a promising strategy to enhance the efficacy and tolerability of chemotherapy in humans. A specifically designed low calorie, low amino acid substitution diet (“Fasting Mimicking Diet”, FMD) has similar effects in vivo during chemotherapy as STF. The DIRECT trial evaluates the impact of FMD on toxicity and efficacy of neoadjuvant chemotherapy in women with HER2-negative early breast cancer.

Patients and methods:

Eligible patients had histologically confirmed, HER2-negative, stage II/III early breast cancer, adequate bone marrow, liver and renal function, BMI > 19kg/m2 and absence of diabetes mellitus. Women receiving 8 neo-adjuvant AC-T courses (adriamycin/cyclophosphamide - docetaxel) or 6 FEC-T courses (5-fluorouracil, epirubicin and cyclophosphamide - docetaxel); day 1, q 3 weeks, were randomized to receive FMD or regular diet for 3 days prior to and at the day of chemotherapy and 3 days prior to surgery. The FMD group received no dexamethasone during the AC or FEC courses. The primary endpoint of the phase II part was feasibility and grade III/IV toxicity and of the phase III pathological complete response (pCR) rate. Additionally, in a side study increase in DNA damage in lymphocytes before and three hours after chemotherapy was compared between the 2 arms.

Results

From February 2014 to January 2018 131 patients from 11 participating Dutch centers were randomized, whereof 100 received AC-T and 31 received FEC-T. Sixty-six of the patients received FMD. Compliance to the diet was low as 32% fasted at least half of the cycles and 24% of patients fasted during all of cycles. The main reasons of non-compliance were food aversion induced by chemotherapy and the taste of the diet. Intention to treat grade III/IV toxicity was not significantly different between the standard arm (67,2%) and in the FMD arm (79,4%), although the majority of the toxicities in the FMD arm were assessed in patients that did not complete the FMD diet preceding the measurements. The total overall pCR rate was 12,8%, lower than assumed in the sample size calculation and would therefore need minimally a doubling in patient numbers to be able to reach the expected pCR difference between both arms. Due to the poor compliance, slow accrual rate and low overall pCR rate the DIRECT study terminated after completion of the phase II part. Subgroup analysis will be presented at SABCS. In a side study, DNA damage after chemotherapy was significantly less increased in lymphocytes in the FMD group as compared to the control group (p=0.043).

Conclusion

The effect of STF on toxicity and efficacy of chemotherapy was not established due to poor compliance, however STF by FMD reduced a transient increase in chemotherapy induced DNA damage. Close monitoring of patients by nutritionists with expertise in low calorie diets as well as diets with a more variable taste are probably needed to successfully examine the impact on adverse effects and tumor biology.

Citation Format: de Groot S, Lugtenberg RT, Welters MJ, Ehsan I, Vreeswijk MP, Smit VT, de Graaf H, Heijns JB, Portielje JE, van de Wouw AJ, Imholz AL, Kessels LW, Vrijaldenhoven S, Baars A, Meershoek-Klein Kranenbarg E, Duijm-de Carpentier M, van Leeuwen-Stok E, Putter H, Longo VD, van der Hoeven JJ, Nortier JW, Pijl H, Kroep JR. DIetary REstriction as an adjunct to neoadjuvant ChemoTherapy for HER2-negative breast cancer: Final results from the DIRECT trial (BOOG 2013-04) [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 P1-15-20.

Prediction model for regional or distant recurrence in endometrial cancer based on classical pathological and immunological parameters

Background:

Adjuvant therapy increases disease-free survival in endometrial cancer (EC), but has no impact on overall survival and negatively influences the quality of life. We investigated the discriminatory power of classical and immunological predictors of recurrence in a cohort of EC patients and confirmed the findings in an independent validation cohort.

Methods:

We reanalysed the data from 355 EC patients and tested our findings in an independent validation cohort of 72 patients with EC. Predictors were selected and Harrell's C-index for concordance was used to determine discriminatory power for disease-free survival in the total group and stratified for histological subtype.

Results:

Predictors for recurrence were FIGO stage, lymphovascular space invasion and numbers of cytotoxic and memory T-cells. For high risk cancer, cytotoxic or memory T-cells predicted recurrence as well as a combination of FIGO stage and lymphovascular space invasion (C-index 0.67 and 0.71 vs 0.70). Recurrence was best predicted when FIGO stage, lymphovascular space invasion and numbers of cytotoxic cells were used in combination (C-index 0.82). Findings were confirmed in the validation cohort.

Conclusions:

In high-risk EC, clinicopathological or immunological variables can predict regional or distant recurrence with equal accuracy, but the use of these variables in combination is more powerful.

Abstract P5-02-04: Tumor heterogeneity impairs robustness of Ki67 scoring in breast cancer

Background

A study by Cheang et al. reported that for ER-positive, HER2-negative breast cancer a Ki67 score ≥14% distinguishes Luminal B from Luminal A tumors. The (neo)adjuvant treatment of these Luminal B tumors consists of endocrine treatment and chemotherapy while chemotherapy can be omitted for Luminal A tumors. For the determination of these subtypes, resection specimens and particularly core biopsies in the neoadjuvant setting are used. Since Ki67 scoring is advocated by some to be a marker in deciding if systemic chemotherapy will be given or not, its assessment should be highly reproducible and reliable. I.e, Ki67 assessment should not vary significantly between different laboratories, but also not within the tumor. To test this, we analyzed (1) interlaboratory agreement using whole slides and (2) agreement within a particular tumor using tissue microarrays (TMA) as well as whole slides from surgical specimens.

Material and methods

The first 100 patients from the microarRAy prognoSTics-in-breast-cancER (RASTER) study (n=427) were selected. From each patient clinicopathological characteristics and tumor blocks were available. From each tumor block 2 whole slides were cut for staining in laboratory 1 and 2. Also six single cores were taken to construct 2 tissue microarrays (core 1-3 and core 4-6). Intrinsic subtypes were defined as follows: Luminal A, Luminal B/HER2-, Luminal B/HER2+, HER2-overexpressing, and Basal-like. Experienced pathologists (EG, JS, VTHMBS, JW) performed the scoring.

Results

There were 99 whole slides suitable for analysis. Substantial agreement (κ = 0.723, P<0.001) was demonstrated in discrimination for Ki67 low and high between whole slides stained in laboratory 1 and laboratory 2 with a discordance rate of 13.1% (Table 1). Moderate agreement (κ = 0.595, κ = 0.584, P<0.001) was demonstrated in discrimination of Ki67 low and high between whole slide and core 1-3 and core 4-6 with a discordance rate of 20.3% and 20.8% respectively (Table 2). Substantial agreement (κ = 0.666) was demonstrated for Ki67 expression between core 1-3 and core 4-6.

Table 1. Discordance between laboratories for whole slide Ki67 result  Laboratory 2     <14%≥14%Discordance rate %KappaSign.Laboratory 1<14%56013.10.723<0.001 ≥14%1330   

Table 2. Discordance between whole slide and core biopsies 1-3 and 4-6 for Ki67 result  Whole slide     <14%≥14%Discordance rate %KappaSign.Core 1-3<14%33920.30.595<0.001 ≥14%730   Core 4-6<14%31820.80.584<0.001 ≥14%830   

Conclusion

Tumor heterogeneity results in substantial variation of Ki67 scores between TMA cores and whole slides that may result in considerable differences in distinguishing luminal A from luminal B ER-positive, HER2-negative tumors. This may have far reaching consequences for the choice for (neo)adjuvant treatment.

Citation Format: Matthijs V Nijenhuis, Emilie Groen, Tim J Dekker, Caroline A Drukker, J Sanders, V T Smit, S Linn, E J Rutgers, J Wesseling. Tumor heterogeneity impairs robustness of Ki67 scoring in breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-02-04.

Intraplacental choriocarcinoma as an unexpected cause of intrauterine death at term

Intraplacental choriocarcinoma is rare. It can cause fetal death at term by fetomaternal hemorrhage. We present a case of intraplacental choriocarcinoma. After a hydatidiform mole with persistence of throphoblastic disease, the patient delivered a stillborn baby at term. Massive fetomaternal hemorrhage was the unexpected cause of death. Choriocarcinoma was only diagnosed after pathologic revision of the placenta because of persistent high levels of serum hCG (human chorionic gonadotropin). Massive fetomaternal hemorrhage should alert the obstetrician and the pathologist to the possibility of choriocarcinoma arising from the placenta.

Quantitative detection of herpes simplex virus DNA in the lower respiratory tract

Quantitation of herpes simplex virus (HSV) DNA in bronchoalveolar lavage specimens could indicate an infectious role in the lower respiratory tract. The aim of this study was to compare quantitative HSV DNA results from adult bronchoalveolar lavage specimens to clinical outcome. Quantitative real-time PCR assays targeting HSV and other herpes viruses were performed on adult bronchoalveolar lavage specimens obtained from a largely immunocompromised population during a 1-year period. The results were compared to patient characteristics and outcome. HSV DNA was detected in 11 (19%) of 57 bronchoalveolar lavage specimens with a mean viral level of 5.6 log genome equivalents/ml (range, 2.9-8.1 log). A threshold of HSV DNA levels equal or higher than 5.0 log (n = 7) was associated with mortality within 28 days following hospital admission (odds ratio [OR], 6.8; 95% confidence interval [CI], 1.2-39.2). A threshold level of 5.5 log was associated with mortality within 28 days of sampling (OR 8.5; 95% CI 1.2-62.1), only after excluding patients receiving specific antiviral medication. Patients with HSV DNA levels equal or higher than 7.5 log had severe respiratory failure. Viral pneumonia was histologically proven in one patient with 8.0 log at autopsy. No patient with HSV DNA levels below 5.5 log (n = 5) or DNA levels higher than 5.0 log of cytomegalovirus (CMV) (n = 3), Epstein-Barr virus (EBV) (n = 9), varicella-zoster virus (VZV) (n = 1), or human herpesvirus 6 (HHV-6) (n = 0) died within 28 days of hospital admission. We conclude that quantitative detection of HSV DNA in bronchoalveolar lavage fluid is a potential diagnostic tool for detection of relevant viral infection of the lower respiratory tract.

New mutations in two Dutch patients with early infantile galactosialidosis

Galactosialidosis is an autosomal recessive lysosomal storage disease caused by a combined deficiency of lysosomal beta-galactosidase and neuraminidase as a result of a primary defect in the protective protein/cathepsin A (PPCA). We report the first 2 Dutch cases of early infantile galactosialidosis, both presenting with neonatal ascites. The defect was identified in urine, leukocytes, and fibroblasts. Residual activity was determined with a modified assay for cathepsin A and was <5% in leukocytes and <1% in fibroblasts. Histological examination of the placenta in case 1 showed extensive vacuolization in all cell types. Northern blot analysis of RNA isolated from the patients' cultured fibroblasts showed substantially decreased levels of the PPCA transcript, which nevertheless had the correct size of 2 kb. Mutation analysis of both mRNA and genomic DNA from the patients identified two novel mutations in the PPCA locus. Case 1 was a compound heterozygote, with a single missense mutation in one allele, which resulted in Gly57Ser amino acid substitution, and a single C insertion at nucleotide position 899 in the second allele, which gave rise to a frame shift and premature termination codon. Case 2 was homozygous for the same C899 insertion found in case 1.

Loss of heterozygosity mapping at chromosome arm 16q in 712 breast tumors reveals factors that influence delineation of candidate regions

Loss of heterozygosity (LOH) at the long arm of chromosome 16 occurs in at least half of all breast tumors and is considered to target one or more tumor suppressor genes. Despite extensive studies by us and by others, a clear consensus of the boundaries of the smallest region of overlap (SRO) could not be identified. To find more solid evidence for SROs, we tested a large series of 712 breast tumors for LOH at 16q using a dense map of polymorphic markers. Strict criteria for LOH and retention were applied, and results that did not meet these criteria were excluded from the analysis. We compared LOH results obtained from samples with different DNA isolation methods, ie., from microdissected tissue versus total tissue blocks. In the latter group, 16% of the cases were excluded because of noninterpretable LOH results. The selection of polymorphic markers is clearly influencing the LOH pattern because a chromosomal region seems more frequently involved in LOH when many markers from this region are used. The LOH detection method, i.e., radioactive versus fluorescence detection, has no marked effect on the results. Increasing the threshold window for retention of heterozygosity resulted in significantly more cases with complex LOH, i.e., several alternating regions of loss and retention, than seen in tumors with a small window for retention. Tumors with complex LOH do not provide evidence for clear-cut SROs that are repeatedly found in other samples. On disregarding these complex cases, we could identify three different SROs, two at band 16q24.3 and one at 16q22.1. In all three tumor series, we found cases with single LOH regions that designated the distal region at 16q24.3 and the region at 16q22.1. Comparing histological data on these tumors did not result in the identification of a particular subtype with LOH at 16q or a specific region involved in LOH. Only the rare mucinous tumors had no 16q LOH at all. Furthermore, a positive estrogen content is prevalent in tumors with 16q LOH, but not in tumors with LOH at 16q24.3 only.

An uncommon cause of stroke in young adults

We describe a previously healthy 48-year-old man who presented with clinical characteristics suggestive of internal carotid artery dissection, confirmed by magnetic resonance imaging. He developed a massive infarction of the left cerebral hemisphere and died after 3 days of transtentorial herniation. Post-mortem examination identified a dissection of the thoracic aorta caused by Erdheim-Gsell cystic medionecrosis, with the characteristic degeneration of the elastic fibers of the lamina media. The dissection showed an unusually large extension not only distally into both iliac arteries, but also proximally into both carotid arteries. To our knowledge, such an extensive dissection has not been described previously. Underlying vessel wall disorders of the aorta, such as Erdheim Gsell cystic medionecrosis, should be considered in young patients with spontaneous arterial dissection.

Rheumatoid vasculitis presenting as appendicitis

Appendicitis was diagnosed in a 38-year-old patient with seropositive rheumatoid arthritis. Despite appendectomy the patient's clinical condition deteriorated. Thorough microscopical evaluation of the pathological anatomical specimens from the appendix made possible a diagnosis of necrotizing vasculitis. The systemic nature of the vasculitis was confirmed with a muscle biopsy. A complete remission was induced with immunosuppressive treatment. The case exemplifies a rare but serious manifestation of rheumatoid vasculitis.

Molecular genetic evidence for the conversion hypothesis of the origin of malignant mixed müllerian tumours

The origin of malignant mixed Müllerian tumours (MMMTs) has long been debated, due to the indefinite relationship between epithelial and mesenchymal malignant cells. In order to obtain insight into the clonal relationship between the two components of these tumours, molecular genetic changes were investigated at the level of loss of heterozygosity (LOH) in both cells types. LOH was studied in a series of six cases with 74 polymorphic microsatellite markers mapping to 19 different chromosomes. The epithelial and the mesenchymal neoplastic cells were separately microdissected from formalin-fixed, paraffin-embedded tissue, prior to DNA isolation. LOH was observed for 35 different markers mapping to chromosomes 3, 6, 8, 11, 15, 16, 17, 18, 21, and X. The most frequently involved chromosomes were 17p, 17q, 11q, 15q, and 21q. LOH was observed in five out of six cases and identical alleles were lost in the epithelial and in the mesenchymal cells. No genetic differences were observed between the two cell types for any of the informative markers. Immunohistochemistry (IHC) and TP53 mutation analysis revealed involvement of TP53 in all cases. Mutations were identified in five MMMTs. In four tumours, of which three had a missense mutation, strong nuclear staining for p53 was observed. In the remaining two cases, the mutation resulted in a stop codon, with no nuclear staining for p53 by IHC. The results support a monoclonal origin of MMMTs, with the absence of genetic changes uniquely associated with either of the phenotypes. The latter finding is compatible with current opinion that these neoplasms should be considered as metaplastic carcinomas and supports the conversion hypothesis.

Efficient replication of human immunodeficiency virus type 1 and measles virus in a human-to-mouse graft versus host disease model permits immunization research

An acute graft versus host disease (GvHD) murine model was developed to study the pathogenic and protective mechanisms against viruses that replicate in cells of the human immune system. The model allowed efficient replication of lymphotropic, macrophage and amphitropic strains of human immunodeficiency virus type 1 (HIV-1) and measles virus (MV). Cytopathic lymphotropic strains of HIV-1 and a wild-type MV strain replicated in a 'burst'-like manner, whereas a non-cytopathic lymphotropic HIV-1 strain and all macrophage-tropic HIV-1 strains caused persistent infection of the graft. The replication kinetics of infection with these viruses were highly reproducible and were very similar to those observed in natural infection of humans. Infection with these viruses, with the exception of HIV-1SF2, led to a delay [corrected] and abrogation of the GvHD, indicating a direct immunosuppressive effect. Interestingly, infection with the lymphotropic HIV-1SF2 strain was rapidly and spontaneously abrogated. The model was also shown to be suitable for the evaluation of passive immunization strategies. Administration of a combination of antibodies against the HIV-1 V3 loop and the HIV-1 CD4 binding sites prevented subsequent infection with HIV-1IIIB. In contrast, administration of CD4 binding site specific human monoclonal antibody at a concentration that would neutralize the virus in vitro enhanced in vivo infection with HIV-1IIIB. The model also allowed evaluation of in vivo immunization studies. Immunization with a live attenuated measles vaccine resulted in protection from a wild-type MV challenge, whereas immunization with a subunit candidate vaccine appeared to give partial protection.

In vitro suppression of leukemia by alkylated interleukin-3

We report the in vitro suppression of the IL-3-dependent MO-7 acute myeloid leukemia proliferation by an interleukin-3 antagonist. The antagonist was generated by alkylation to inactivate catalytic His-residues of native human interleukin-3. The resulting inhibitor caused a factor 7 inhibition of the growth-response curve of the IL-3 control-stimulated proliferation of a MO-7 leukemia cell line. A 40% inhibition of the MO-7 proliferation could be achieved with a partially alkylated inhibitor in presence of a factor 30 excess of native IL-3. Therefore, the inhibitor had a substantially improved affinity for the IL-3 receptor on these leukemia cells. At a concentration of as low as 0.1 ng/ml it still caused a 2-fold inhibition of the native IL-3-stimulated proliferation response curve. Thus it can be concluded that this alkylate IL-3 is a potent IL-3 antagonist. Based on the reported specific zinc binding of IL-2, IL-6, GM-CSF and gamma-interferon this suggests that more leukemias and even other forms of cancer can be effectively suppressed by alkylated growth factors.

Surgical/pathologic-stage migration confounds comparisons of gastric cancer survival rates between Japan and Western countries

PURPOSE

Possible causes underlying the substantial differences in gastric cancer survival rates observed between Japan and the West were examined in a randomized trial comparing the Western R1 resection with limited lymphadenectomy and the Japanese R2 resection with extended lymphadenectomy.

PATIENTS AND METHODS

The effect of four factors associated with lymphadenectomy on microscopic tumor-node-metastasis (TNM) staging, and on stage-specific survival rates was assessed in 473 curatively resected patients.

RESULTS

After application of extended lymphadenectomy, additional information on N status was available, only in R2 resections with up-staging to N2 status in 30% of patients. The calculated effect of this stage migration on known 5-year survival rates was as follows: an increase of 1% in TNM stage Ia, 2% in Ib, 7% in II, 15% in IIIa, and 15% in IIIb. A further increase in survival was observed by stage migration to N3 or N4 status, due to selective extension of lymphadenectomy to clinically overt metastases located outside the allocated level of clearance (contamination). Incomplete lymphadenectomy of N1- or N2-level stations indicated for dissection (noncompliance) demonstrates that more migration can occur when strictly adhering to the protocol. Examining more nodes per N level (diligence) induces even more migration, since the number of nodes that were histologically examined per N level correlated significantly with nodal status (lymph node-negative [N-] or lymph node-positive [N+]).

CONCLUSION

These factors explain, at least partially, superior stage-specific survival rates after R2 compared with R1 resections, without a real survival benefit in individual patients.

Native electrophoresis to monitor chemical modifications of human interleukin-3

Native electrophoresis on the Pharmacia PhastSystem using a new buffer system is used to monitor chemical modifications of human interleukin-3. The method is faster, more gentle and more convenient than amino acid analysis. Micrograms of protein suffice in contrast with milligrams required in spectrophotometric methods. As compared to generally used native electrophoresis, the combination of a changed conductivity, lower pH and the low density matrix results in a much better separation and detection of both the reaction products containing a high charge and the reaction products containing a low charge. This enables monitoring of extensive modifications as well as mild modifications. Our method also provides indications for denaturation of the protein. It has proven to be highly reproducible for at least 10 different modification reactions. Information can be obtained about the presence of the various distinct forms of the modified molecule, for instance leading to the average number of groups on the molecule. It also detects modifications not detectable with generally used native electrophoresis.

Establishment and characterization of 7 ovarian carcinoma cell lines and one granulosa tumor cell line: growth features and cytogenetics

The characteristics of 7 newly established ovarian carcinoma cell lines and one granulosa tumor cell line obtained from tumor samples of 7 patients with varying histology of the primary tumor are reported. The cell lines were isolated from 5 serous carcinomas, a mucinous carcinoma, an endometrioid carcinoma and a granulosa cell tumor. All cell lines were passaged at least 25 times and showed stable growth rates. Colony-forming efficiency varied on plastic from 2 to 57% and in agar from 0.01 to 9.30%. The DNA index of the granulosa tumor cell line was diploid, while the ovarian carcinoma cell lines were all aneuploid. In 2 cell lines polyploidisation occurred during culturing. A thorough cytogenetic analysis of 7 cell lines revealed that the granulosa tumor cell line has only minor cytogenetic abnormalities (+5, 22q+). In contrast, the epithelial ovarian-cancer cell lines gave very complex karyotypes with numerous markers and structurally rearranged chromosomes. The chromosomes most often in excess were 15 and 20. Structural rearrangements of chromosomes 1, 3, 7 and 11 were prominent in all ovarian cell lines. In addition, we found changes in chromosomes X, 5, 8 and 13 that have rarely been described before.

Human interleukin-3 contains a discontinuous zinc binding domain

The primary structure of human interleukin-3 contains two amino acid consensus sequences at Glutamate 22- Histidine 26 and Histidine 95-Histidine 98, that are characteristic for zinc binding proteins. Therefore, the hypothesis was tested that human interleukin-3 binds zinc specifically by either one or both sequences. Protein dotblotting, followed by probing with radioactive zinc demonstrated specific zinc binding of interleukin-3. Metal specificity was confirmed by competition experiments with 12 other divalent- and trivalent metal ions. Protease treatment combined with plasma desorption mass spectrometry was used to localize the zinc binding domain. Specific zinc binding was restricted to a fragment composed of Threonine 11-Lysine 28 and Asparagine 80-Lysine 100. It was found to decrease by a factor of five when either of these two amino acid stretches was missing. It is concluded that human interleukin-3 is a zinc binding protein. Interleukin-3 zinc binding capacity is largely determined by both moieties of the protein that contain the consensus sequences. In addition we propose that the zinc binding of hIL-3 is involved in (de)phosphorylation of the hIL-3 receptor.

Alpha satellite DNAs on chromosomes 10 and 12 are both members of the dimeric suprachromosomal subfamily, but display little identity at the nucleotide sequence level

We have investigated the organization and complexity of alpha satellite DNA on chromosomes 10 and 12 by restriction endonuclease mapping, in situ hybridization (ISH), and DNA-sequencing methods. Alpha satellite DNA on both chromosomes displays a basic dimeric organization, revealed as a 6- and an 8-mer higher-order repeat (HOR) unit on chromosome 10 and as an 8-mer HOR on chromosome 12. While these HORs show complete chromosome specificity under high-stringency ISH conditions, they recognize an identical set of chromosomes under lower stringencies. At the nucleotide sequence level, both chromosome 10 HORs are 50% identical to the HOR on chromosome 12 and to all other alpha satellite DNA sequences from the in situ cross-hybridizing chromosomes, with the exception of chromosome 6. An 80% identity between chromosome 6- and chromosome 10-derived alphoid sequences was observed. These data suggest that the alphoid DNA on chromosomes 6 and 10 may represent a distinct subclass of the dimeric subfamily. These sequences are proposed to be present, along with the more typical dimeric alpha satellite sequences, on a number of different human chromosomes.

Detection of migrated allogeneic oligodendrocytes throughout the central nervous system of the galactocerebrosidase-deficient twitcher mouse

Galactocerebrosidase-deficient oligodendrocytes of 'twitcher' (twi/twi) mice degenerate prematurely. Transplantation of normal bone marrow cells has been shown to alleviate symptoms and to prolong survival time. However, characteristic ataxia ('twitching') is not cured. In an attempt to improve further the condition of twitcher mice, allogeneic foetal liver cells were transplanted as a source of normal haemopoietic stem cells and supplemented with intracerebral transplantation of foetal brain cells. A reliable method was developed to detect donor-type cells in brain tissue. Bacteriophage lambda transgenic foetal mice were used as donors of both foetal liver and brain cells. Integrated copies of lambda DNA in donor cells were detected by in situ hybridization with biotinylated probes, which were then stained using streptavidin alkaline phosphatase. This technique was combined with immunohistochemistry to distinguish donor-type oligodendrocytes from macrophages. Immunoperoxidase staining with an antiserum to carbonic anhydrase-II produced dark perikarya of oligodendrocytes. The results demonstrated that local foetal brain cell grafts resulted in a wide dissemination of donor-type oligodendrocytes throughout the twitcher brain. The addition of a foetal brain cell graft to haemopoietic cell transplantation resulted in significantly prolonged survival of twitcher mice.

Improved interpretation of complex chromosomal rearrangements by combined GTG banding and in situ suppression hybridization using chromosome-specific libraries and cosmid probes

Chromosome aberrations of a hypodiploid ovarian carcinoma cell line (modal chromosome number 38) having a complex karyotype were analyzed using biotinylated DNA library probes that specifically hybridize to chromosomes 3, 6, 7, 8, 11, 13, and 16 from telomere (pter) to telomere (qter). A series of cosmid probes localized to the short arm of chromosome 16 were used to further investigate one of the two aberrant chromosomes 16 present in this cell line. The competitive in situ suppression (CISS) hybridization of DNA-libraries was mostly performed subsequent to GTG-banding of the same metaphase cell in order to interpret the hybridization signals optimally. This combined approach made it possible to detect the origin of chromosomal material that could not be identified using GTG-banding. Furthermore, the in situ hybridization techniques appeared to be helpful in the characterization of complex translocations and for accurate breakpoint determination.

Flow cytometric analysis of DNA stemline heterogeneity in primary and metastatic breast cancer

Flow cytometric DNA-ploidy analysis was used to investigate intratumor DNA stemline heterogeneity in primary breast carcinomas and lymph node metastases (LNM). The study was done in tumor specimens from 44 patients 35 of whom had LNM. In all, measurements were done in 214 different samples of primary tumors and 211 lymph nodes. Sixty-one percent (27/44) of the primary tumors were found to have multiple DNA aneuploid stemlines when the data of the separate samples per tumor (mean 4.9) were compared. Only five of 44 (11%) primary tumors were DNA diploid; two of these had DNA aneuploid metastases. Statistical analysis of these results indicated that, on average, four samples are needed for reliable determination of the DNA ploidy status of primary tumors by flow cytometry. In the majority of the cases (26/35), distinct tumor DNA stemlines found in LNM were also present in the primary tumor, which suggests that the generation of DNA ploidy diversity may have taken place prior to metastasis. Multiploidy was not related to tumor size but, particularly for LNM, was significantly correlated with age (r = 0.40, P = 0.02). The results of this study support the view that breast cancer is an extremely heterogeneous disease and that underestimation of this factor might account for the disagreement in literature about the prognostic value of DNA ploidy determinations.

Flow cytometric DNA-ploidy analysis of synchronously occurring multiple malignant tumors of the female genital tract

In this study the authors applied flow cytometric DNA-ploidy analysis to multiple female genital tract malignant tumors in 43 patients, most of whom (n = 37) had bilateral ovarian cancer. An algorithm was developed for calculation of the likelihood ratio of the probabilities that measured DNA index differences between multiple tumor localizations within the same patient could be attributed to measurement variation or to true biologic DNA content differences. The results of this statistical analysis show that in 72% of the cases (31 of 43) this probability ratio exceeded 1. Because the probability that two independent tumors will have a near-identical aneuploid DNA content is very low, this finding supports a metastatic process rather than the occurrence of multiple primary tumors in these patients. Thus, flow cytometric DNA-ploidy analysis can be helpful in the identification of metastatic disease in patients with multiple female genital tract malignant tumors.

Localization and polymorphism of a chromosome 12-specific alpha satellite DNA sequence

The isolation and localization of a chromosome 12-specific alpha satellite DNA sequence, p alpha 12H8, is described. This clone contains a complete copy of the 1.4-kb HindIII higher-order repeat present within the alpha satellite array on chromosome 12. The specificity of p alpha 12H8 was demonstrated by in situ hybridization and Southern blot analysis of a somatic cell hybrid mapping panel, both performed under high-stringency conditions. Polymorphic restriction patterns within the alpha satellite array, revealed by the use of the restriction enzymes BglII and EcoRV, were demonstrated to display Mendelian inheritance. These properties make p alpha 12H8 a valuable genetic marker for the centromeric region of chromosome 12.

Combined GTG-banding and nonradioactive in situ hybridization improves characterization of complex karyotypes

Nonradioactive in situ hybridization (ISH) using biotinylated centromere probes for chromosomes 1, 6, 7, 10, 16, 17, 18, and the X, respectively, was combined with GTG-banding to study cytogenetic changes in two different ovarian cancer cell lines. ISH was performed after GTG-banding on the same metaphase. The use of a low trypsin concentration (0.01%) in the banding procedure was essential for subsequent ISH. This combined approach allows the detection of subtle chromosomal rearrangements and appears to aid the identification of marker chromosomes.

Analysis of tumor heterogeneity in a patient with synchronously occurring female genital tract malignancies by DNA flow cytometry, DNA fingerprinting, and immunohistochemistry

A case of a patient with bilateral ovarian cancer and a uterine malignant mesodermal mixed tumor with ascites and metastatic disease is presented. Flow cytometry, DNA fingerprinting, and immunohistochemistry were performed to assess the origin of these malignancies. Ploidy analysis showed that both ovarian tumors had different aneuploid stemlines (DNA index [DI] = 1.64, 1.85, right ovary and DI = 1.73, left ovary) indicating independent origins. One of the stemlines in the right ovary (DI = 1.64) was also present in the ascites cells, whereas omentum metastases showed the same stemline (DI = 1.73) as the left ovarian tumor. The uterine malignancy contained three aneuploid stemlines. The highest stemline was associated with epithelial differentiation, but a metastatic origin from the left ovarian tumor seems unlikely. DNA fingerprinting analysis revealed a common change in restriction fragment length pattern in the DNA from all tumor localizations as compared with the patient's constitutional DNA. These results indicate that DNA flow cytometry can be helpful in discriminating intragenital metastatic disease from multiple primary tumors.

KRAS codon 12 mutations occur very frequently in pancreatic adenocarcinomas

DNAs from human pancreatic adenocarcinomas were analyzed for the presence of mutations in codons 12, 13 and 61 of the NRAS, KRAS and HRAS gene. Formalin-fixed and paraffin-embedded tissue was used directly in an in vitro amplification reaction to expand the relevant RAS sequences. The mutations were detected by selective hybridization using mutation-specific synthetic oligonucleotides. In 28 of the 30 patients we found a mutation in codon 12 of the KRAS gene. This result confirms the findings of Almoguera et al. [Cell 53 (1988) 549-554] that KRAS mutations occur frequently in adenocarcinomas of the exocrine pancreas. The mutations are predominantly G-T transversions, in contrast to the KRAS mutations in colon tumors which are mainly G-A transitions. Furthermore, in a portion of the tumors the mutation appears to be homozygous.

Immunohistology of a sarcomatous mural nodule in an ovarian mucinous cystadenocarcinoma

Mucinous tumors of the ovary are incidentally associated with ovarian sarcoma. Several cases of sarcoma-like mural nodules in ovarian mucinous tumors have been described previously, but only two well-documented cases of true sarcoma were reported. The purpose of this article is to report a case of sarcoma occurring in ovarian mucinous neoplasm, which differs histologically from the two cases described earlier. This case is the first of its kind with immunohistochemical characterization.

Acute pancreatitis in systemic lupus erythematosus

Lethal acute pancreatitis developed in a 16-year-old Caucasian woman suffering from systemic lupus erythematosus. Until the time of onset of pancreatitis, the patient's medications included prednisone, furosemide, ethacrynic acid and chlorthalidone, all of which have been related to pancreatitis. At autopsy, no specific signs of autoimmune activity were found in the diseased pancreatic tissue. A review of the literature shows that information on the association of pancreatitis and SLE is scarce. This case illustrates the dilemma of pathogenesis and therapy of acute pancreatitis in SLE and the need for further investigation.