Multiplexed Tumor Marker Profiling at Single-Cell Resolution: Quantifying Breast Cancer Molecular Signatures

Excluding skin cancers, about 1.5 million new cases of cancer and about 450,000 cancer related deaths occur each year in the United States. The validation and molecular profiling of tumor markers are contributing to new paradigms in cancer research. In this presentation, we will discuss the information that can be obtained by using an Intelligent Single-Cell Optical Profiling Engine (I-SCOPE), consisting of hyperspectral imaging, multiplexed biomarker kits, and bioinformatics tools, to markedly expand the molecular profiling of tumor markers on individual carcinoma cells.Using biomarker antibodies conjugated to particular fluorochromes, we developed a multiplex of 10 different fluorochrome conjugates, one for each different tumor marker plus a nuclear dye. Staining and scanning using the I-SCOPE system showed that it can presently distinguish 10 different fluorochromes in a single pass, resulting in the identification of spatial location and relative intensity of each biomarker being interrogated. By using this system, we analyzed thousands of tumor cells from touch preparations of tumor tissue, circulating tumor cells (CTCs) in pleural fluid and blood, and disseminated tumor cells (DTCs) from bone marrow with 2 multiplex kits for a total of 17 different tumor markers. We have utilized clinically-accepted markers such as estrogen receptor (ER), progesterone receptor (PR), and HER2 in addition to biomarkers undergoing investigation such as B-cell lymphoma 2 (Bcl-2) and urokinase-type plasminogen receptor (uPAR). Furthermore, with the ability to simultaneously image 10 markers, each panel can also contain desired positive and negative controls such as CD45 (positive for white blood cells, negative for CTCs) and cytokeratin (positive for epithelial cells).The results of immunophenotyping of individual tumor cells with 17 different tumor markers indicated that the average expression of each tumor marker in 25 tumor cells was a reproducible representation of the tumor. However, comparison of individual CTCs' expression levels revealed remarkable heterogeneity in primary breast cancer cases.We conclude that hyperspectral microscope imaging together with individual tumor cell analysis represents a major step forward in developing a far more detailed and precise molecular signature of a patient's cancer. Further studies might demonstrate how it can facilitate treatment tailored to the individual patient's tumor, an important objective as new oncology drugs with specific molecular targets become more prevalent.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6002.

The HLA-G 14 bp insertion/deletion polymorphism is a putative susceptible factor for active human cytomegalovirus infection in children

Human leukocyte antigen-G (HLA-G) expression is a potential factor for the pathogenesis of virus infection. A 14 bp insertion/deletion polymorphism (rs16375) in the 3'-untranslated region of the HLA-G gene is involved in the stability of HLA-G mRNA and HLA-G protein expression. Therefore, the HLA-G 14 bp polymorphism might be involved in human cytomegalovirus (hCMV) infection. To test a possible association between the HLA-G 14 bp deletion/insertion polymorphism and the active hCMV infection, in this study, a total of 54 patients with active hCMV infection and 165 age- and sex-matched, unrelated, normal Chinese Han population were genotyped for the 14 bp insertion/deletion polymorphism. Association of 14 bp polymorphism with hCMV urine DNA copies and the odds ratio (OR) of the polymorphism as a risk factor for active hCMV infection were analyzed. Our results showed that the prevalence of -14 bp/ -14 bp genotype in active hCMV patients was markedly increased [P(c) = 0.00034, OR = 3.31, 95% confidence interval (CI): 1.77-6.18], and similar significance was also observed for the frequency of -14 bp allele (P c = 0.0023, OR = 2.24, 95% CI: 1.38-3.64) when compared with that of healthy controls. Furthermore, urine hCMV DNA copies in patients with the -14 bp/ -14 bp genotype were significantly higher than those in patients with the +14 bp/ +14 bp genotype (P = 0.041). Our findings support a potential role of HLA-G 14 bp insertion/deletion polymorphism as a susceptible factor for the active hCMV infection.

The OptIPuter microscopy demonstrator: enabling science through a transatlantic lightpath

The OptIPuter microscopy demonstrator project has been designed to enable concurrent and remote usage of world-class electron microscopes located in Oxford and San Diego. The project has constructed a network consisting of microscopes and computational and data resources that are all connected by a dedicated network infrastructure using the UK Lightpath and US Starlight systems. Key science drivers include examples from both materials and biological science. The resulting system is now a permanent link between the Oxford and San Diego microscopy centres. This will form the basis of further projects between the sites and expansion of the types of systems that can be remotely controlled, including optical, as well as electron, microscopy. Other improvements will include the updating of the Microsoft cluster software to the high performance computing (HPC) server 2008, which includes the HPC basic profile implementation that will enable the development of interoperable clients.

The use of drotrecogin alfa (activated) in solid organ transplant patients: a case series

BACKGROUND

Drotrecogin alfa (activated) (DAA), a recombinant human activated protein C, is indicated for the reduction of mortality in patients with severe sepsis who have a high risk of death. In the initial trial, DAA demonstrated a significant reduction in mortality at 28 days for patients treated with DAA in comparison with standard supportive treatment (placebo). However, solid organ transplant recipients were excluded from the study. Transplant recipients are at an increased risk for sepsis and there is minimal literature describing the safety and efficacy of DAA in the transplant population.

METHODS

Thirteen solid organ transplant recipients who received DAA between November 2001 and January 2004 were included in this case series. Patients were prospectively identified and data collection occurred concurrently and by retrospective chart review. All patients met the DAA use criteria based on the institutional standard protocol.

RESULTS

We report the outcomes of the 13 adult transplant patients who received a total of 14 courses of DAA for severe sepsis. At the time of DAA initiation, all patients required mechanical ventilation, 86% necessitated vasopressor support, and had a median of 3 dysfunctional organs. The median Acute Physiology and Chronic Health Evaluation (APACHE) II score at initiation was 30. Overall, hemodynamic stability and APACHE II score improved at the end of DAA infusion. Causes of early discontinuation were bleeding (57%), scheduled procedure (14%), increased international normalized ratio (14%), and death (14%). In-hospital, 28-day, and 1-year mortality was 69%, 62%, and 83%, respectively.

CONCLUSION

DAA appears to be safe with appropriate monitoring. However, transplant recipients had a higher incidence of bleeding events leading to early discontinuation of DAA. Efficacy is difficult to assess without an appropriate control group for comparison.

Unfavourable clinical implications for HLA-G expression in acute myeloid leukaemia

Human leukocyte antigen-G (HLA-G) molecule exerts multiple immunoregulatory functions that have been suggested to contribute to the immune evasion of tumour cells. Studies on HLA-G expression in malignant haematopoietic diseases are controversial, and the functions of HLA-G on this context are limited. In the current study, HLA-G expression was analysed in different types of patients: de novo acute myeloid leukaemia (AML, n = 54), B cell acute lymphoblastic leukaemia (B-ALL, n= 13), chronic myeloid leukaemia (CML, n= 9) and myelodysplastic syndrome (MDS, n= 11). HLA-G expression was observed in 18.5% cases of AML, 22.2% in CML and 18.2% in MDS, but not in B-ALL patients. In AML, HLA-G-positive patients had a significant higher bone marrow leukaemic blast cell percentage when compared with that of HLA-G-negative patients (P < 0.01). Total T-cell percentage was dramatically decreased in HLA-G-positive patients (P < 0.05). Cytogenetic karyotyping results showed that all HLA-G-positive AML patients (n= 5) were cytogenetically abnormal, which was markedly different from that of HLA-G-negative patients (P < 0.01). Ex vivo cytotoxicity analysis revealed that HLA-G expression in AML leukaemic cells could directly inhibit NK cell cytolysis (P < 0.01). These findings indicated that HLA-G expression in AML is of unfavourable clinical implications, and that HLA-G could be a potential target for therapy.

The 14 bp deletion polymorphisms in HLA-G gene play an important role in the expression of soluble HLA-G in plasma

Soluble human leukocyte antigen-G (sHLA-G) functions as a multiple immunoregulator. A 14 bp insertion (+14 bp)/deletion (-14 bp) polymorphism in exon 8 of the HLA-G gene has been proposed to be associated with HLA-G mRNA stability and the expression of HLA-G. In the current study, a total of 150 normal Chinese Han population had been genotyped for the +14 bp/-14 bp polymorphism, and the expression of plasma sHLA-G was determined with enzyme-linked immunosorbent assay in these case-matched plasma. Data showed that genotype of 14 bp polymorphism was significantly associated with sHLA-G expression. Plasma sHLA-G level with the +14 bp/+14 bp genotype was dramatically lower than that with +14 bp/-14 bp (P = 0.004) and -14 bp/-14 bp genotypes (P = 0.003), while no dramatic difference was observed between the +14 bp/-14 bp and -14 bp/-14 bp genotypes (P > 0.05). In both males and females, plasma sHLA-G with the +14 bp/+14 bp genotype was also significantly lower when compared with other two respective 14 bp genotypes. Data also showed that sHLA-G expression was unrelated to gender. This study suggests that the 14 bp deletion polymorphism in the HLA-G gene plays an important role in sHLA-G expression and that interpretation of the potential biological functions of sHLA-G should be made with caution, taking the polymorphism into consideration.

Analysis of the HFE gene (C282Y, H63D and S65C) mutations in a general Chinese Han population

Hereditary hemochromatosis (HH) is one of the most common autosomal recessive genetic disorders of iron metabolism in white populations, which leads to inappropriately high iron absorption. C282Y, H63D, and S65C are three major missense mutations of the hemochromatosis gene (HFE). In the present study, C282Y, H63D, and S65C mutations in 395 normal Chinese Han populations from Zhejiang province were investigated. No C282Y, S65C mutations, and H63D homozygote was observed, while the genotype frequency of H63D heterozygote was 4.6% and the allelic frequency 2.3% in this population. This was the first report to analyze the prevalence of C282Y, H63D, and S65C mutations in the HFE gene in a Chinese Han population. Low incidence of the HFE gene mutations could be a reason for the rarity of HH in the Chinese Han population studied.

14 bp deletion polymorphism in the HLA-G gene is a risk factor for idiopathic dilated cardiomyopathy in a Chinese Han population

Human leukocyte antigen (HLA) has been reported to be associated with the pathogenesis of autoimmune-associated idiopathic dilated cardiomyopathy (IDC). However, the HLA-G in this context is limited. In the current study, a total of 117 IDC patients and age and sex matched 401 unrelated healthy controls in a Chinese Han population were HLA-G genotyped for the 14 bp insertion and deletion polymorphism. IDC patients showed markedly increased frequencies of -14 bp/-14 bp genotype [Pc = 0.00049, odds ratio (OR) = 2.17] and -14 bp alleles (Pc = 4.1 x 10(-5), OR = 1.97) when compared with healthy controls. Whereas the frequencies of +14 bp/+14 bp genotype (Pc = 0.0036, OR = 0.35) and +14 bp alleles (Pc = 4.1 x 10(-5), OR = 0.51) were significantly lower in IDC. These data, for the first time, indicated that 14 bp insertion/deletion polymorphism in HLA-G gene could be a genetic risk factor for the susceptibility to IDC.

HLA-G expression in human ovarian carcinoma counteracts NK cell function

BACKGROUND

Human leukocyte antigen-G (HLA-G) is an important immunotolerant which could be a part of the strategies applied by malignant cells applied to avoid host immunosurveillance. Aberrant expression of HLA-G has been found in ovarian carcinoma. The aim of this study was to evaluate the HLA-G expression in ovarian cancer tissues and to explore its function in vitro.

MATERIALS AND METHODS

HLA-G expression in 33 primary ovarian carcinoma tissues was analyzed using immunohistochemistry with the anti-HLA-G monoclonal antibody (mAb) 4H84. Furthermore, the function of HLA-G in NK cell cytotoxicity was determined in vitro by cloning and expression of HLA-G on the ovarian carcinoma cell OVCAR-3.

RESULTS

HLA-G expression was detected in 22/33 (66.7%) primary tumor tissues, but was absent in normal ovarian tissues (P<0.01). Cytotoxicity studies showed that HLA-G expression dramatically inhibits cell lyses by NK-92 cells (P<0.01), which could be restored by the anti-HLA-G conformational mAb 87G (P<0.01).

CONCLUSION

HLA-G was expressed in a significant number of primary ovarian carcinoma tissues, and HLA-G expression in OVCAR-3 could directly inhibit NK-92 cell lysis. Taken together, our results indicated that expression of HLA-G plays an important role in evasion of ovarian cancer cells from host immunosurveillance.