c-Met is a prognostic marker and potential therapeutic target in clear cell renal cell carcinoma

BACKGROUND

Activation of the c-Met pathway occurs in a range of malignancies, including papillary renal cell carcinoma (RCC). Its activity in clear cell RCC is less clear. We investigated c-Met expression and inhibition in a large cohort of RCC tumors and cell lines.

METHODS

c-Met protein expression was determined by automated quantitative analysis (AQUA) on a tissue microarray (TMA) constructed from 330 RCC tumors paired with adjacent normal renal tissue. c-Met expression and selective inhibition with SU11274 and ARQ 197 were studied in clear cell RCC cell lines.

RESULTS

Higher c-Met expression was detected in all RCC subtypes than in the adjacent normal renal tissue (P < 0.0001). Expression was highest in papillary and sarcomatoid subtypes, and high-grade and stage tumors. Higher c-Met expression correlated with worse disease-specific survival [risk ratio = 1.36; 95% confidence interval (CI) 1.08-1.74; P = 0.0091] and was an independent predictor of survival, maintained in clear cell subset analyses. c-Met protein was activated in all cell lines, and proliferation (and colony formation) was blocked by SU11274 and ARQ 197.

CONCLUSIONS

c-Met is associated with poor pathologic features and prognosis in RCC. c-Met inhibition demonstrates in vitro activity against clear cell RCC. Further study of ARQ 197 with appropriate biomarker studies in RCC is warranted.

C-met as a therapeutic target using ARQ 197 in renal cell carcinoma

360

Background: c-Met is a receptor tyrosine kinase involved in normal cellular growth and vascular development. It has also been identified as a proto-oncogene. Activating c-Met mutations and indirect c-Met activation via von Hippel-Lindau gene silencing have been demonstrated in renal cell carcinoma (RCC) for papillary and clear cell histologic subtypes, respectively. We studied c-Met expression in a large cohort of RCC tumors and investigated in vitro activity of the new selective c-Met inhibitor, ARQ 197.

Methods: Tissue microarrays were performed to analyze c-Met protein expression in situ in 317 RCC tumor specimens using Automated Quantitative Analysis (AQUA). Western blots were performed for c-Met, phospho-c-Met and downstream pathway markers in 6 RCC cell lines (A498, ACHN, Caki-1, Caki-2, 769P, and 786-O). In vitro activity of ARQ 197 was studied by cell viability and clonogenic assays, and by changes in c-Met and down-stream mediators.

Results: c-Met expression is higher in RCC than adjacent normal renal tissue (p < 0.0001) and is expressed in all subtypes of RCC, including clear cell carcinoma; expression is highest in papillary and sarcomatoid subtypes. Greater c-Met expression correlates with higher tumor grade (p = 0.0019) and clinical stage (p = 0.0208), and is an independent predictor of poor overall survival (Multivariate Cox LR 5.7, p = 0.017). c-Met expression correlates to decreased survival in the clear cell subset as well. c-Met protein is activated (phosphorylated) in all 6 RCC cells. ARQ 197 inhibits cell growth in RCC cell lines at nanomolar concentrations (IC50 350-680 nM) and inhibits colony formation at 500 nM. ARQ 197 decreases phosphorylation of c-Met in time- and dose-dependent patterns with dose-dependent decreases in phospho-ERK.

Conclusions: c-Met expression is an independent predictor of survival in RCC, including clear cell subtype, suggesting that it is a potential therapeutic target worthy of further investigation. ARQ 197 effectively inhibits proliferation of clear cell carcinoma cell lines. Further preclinical studies are planned to determine mechanism of cellular arrest and apoptosis and markers of drug sensitivity and resistance.

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Growth factor receptor-bound protein-7 (Grb7) as a prognostic marker and therapeutic target in breast cancer

BACKGROUND

Growth factor receptor-bound protein-7 (Grb7) is an adapter-type signaling protein recruited to various tyrosine kinases, including HER2/neu. Grb7-specific inhibitors are in early development. As with other targeted therapies, response to therapy might be associated with target expression.

MATERIALS AND METHODS

Tissue microarrays containing 638 primary breast cancer specimens with 15-year patient follow-up were employed to assess Grb7 expression using our Automated QUantitative Analysis method; cytokeratin defines pixels as breast cancer (tumor mask) within the histospot, and Grb7 expression within the mask is measured with Cy5-conjugated antibodies.

RESULTS

High Grb7 expression was strongly associated with decreased survival in the entire cohort and in the node-positive subset (P = 0.0034 and P = 0.0019, respectively). On multivariable analysis, it remained an independent prognostic marker (P = 0.01). High Grb7 was strongly associated with high HER2/neu, and coexpression of these molecules was associated with worse prognosis than HER2/neu overexpression alone.

CONCLUSIONS

High Grb7 defines a subset of breast cancer patients with decreased survival, indicating that Grb7 might be a valuable prognostic marker and drug target. Coexpression with HER2/neu indicates that cotargeting these molecules might be an effective approach for treating HER2/neu-positive breast cancers. Future studies using Grb7-targeting agents should include assessment of Grb7 levels.

Construction of a five-marker protein-based model for stage-independent assessment of prognosis in breast cancer

11013

Background: While the TNM method for assessment of stage in breast cancer is simple and robust, molecular methods for limited patient subsets are gaining popularity (i.e Oncotype Dx or Mammaprint). We hypothesized that multiplexed quantitative measurement of proteins known to be involved in breast cancer signaling pathways of growth, proliferation, survival, and metastasis can enhance clinical methods of predicting prognosis in all patients. Methods: We assessed the expression of twenty-three proteins (ER, PR, EGFR, HER2, HER3, HER4, ERK, PTEN, PI3Kp85α, PI3Kp110α, p27/Kip1,EIF4E, FOXO3,AKT1, AKT2, AKT3, MYC, cyclinD1, FOXO1, mTOR, p70S6Kb, NFkB and BCL2) in four subcellular compartments by automated quantitative analysis of protein expression (AQUA) on tissue microarrays of the archival Yale breast cancer cohort (n=676). To project future performance of these markers including clinicopathological parameters, we constructed univariate and multivariate logistic regression models using leave-one-out cross-validation and calculated prediction error (PE) estimates of each model's value to predict a binary endpoint of 10 year survival. In addition, we constructed univariate and multivariate Cox models of ten year disease specific survival (DSS). Results: By Cox univariate analysis, ER, PR, PTEN, and BCL2 were directly correlated with DSS, while FOXO1, HER2, HER3, and PI3Kp110α were inversely correlated with DSS. A five-variable logistic regression model of 10 year survival including nuclear AKT1, BCL2, nuclear FOXO1, cytoplasmic mTOR, and nuclear p70S6Kb (prediction error= .274) surpasses performance of TNM staging (PE=.367) and the Nottingham Prognostic Index (PE=.326). The same model is associated with 10-year DSS by Cox proportional hazard (p=<.00001) independent of TNM stage and NPI. Conclusions: Our protein-based, multiplexed approach to prognostic classification was superior to traditional methods (TNM or NPI) and single biomarkers in this retrospective cohort. Current outcomes are influenced by modern therapies, limiting the direct impact of this analysis. However, molecular profiling of primary tumor linked to outcome paves the way for the incorporation of new prognostic models into prospective studies.

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Microvessel area using automated image analysis is reproducible and is associated with prognosis in breast cancer

Microvessel density may be one measure of tumor associated angiogenesis but is methodologically difficult to standardize and reproduce. We used our automated quantitative image analysis system, AQUA, to more objectively assess microvessel area. Cytokeratin and CD31 were used to create tumor and vessel compartments respectively with AQUA. Microvessel area was defined as CD31 compartment area normalized to the tissue spot area (CD31 area/area of entire tissue spot). Consecutive breast cancer whole sections were stained with CD31 to compare pathologist-based microvessel density with AQUA microvessel area. Microvessel areas of 3-fold redundant tissue microarrays of 652 primary breast cancers were also assessed. CD34 and factor VIII-related antigen were also tested. There was nearly linear correlation between pathologist's microvessel density and AQUA microvessel area with regression coefficient R = 0.846. On the redundant arrays, of the 67% evaluable cases, 52% were microvessel area high and 48% low with good reproducibility of scores (Spearman rho 0.551). AQUA microvessel area was associated with larger tumors, node positivity, and estrogen receptor negativity, with 20 year survival at the univariate and multivariate levels (P < .0001 and P = .0121, respectively). CD34 or factor VIII-related antigen were more heterogenous, had poor association with CD31, and did not correlate with outcome. AQUA-based microvessel area was significantly correlated with both standard breast cancer prognostic parameters as well as with clinical outcome. In the future, it may also allow the use of the AQUA-based algorithms to quantify the expression of angiogenic biomarkers to either tumor or microvessel area-specific compartments.

HSP90 as a marker of progression in melanoma

BACKGROUND

HSP90 chaperones molecules critical for cell survival and malignant progression, including mutated B-raf. HSP90-targeting agents are in clinical trials. No large studies have been conducted on expression of HSP90 in melanomas.

MATERIALS AND METHODS

Tissue microarrays containing 414 nevi, 198 primary and 270 metastatic melanomas were assessed using our automated quantitative analysis (AQUA) method of in situ protein measurement; we use S-100 to define pixels as melanocytes (tumor mask) within the array spot, and measure HSP90 expression within the mask using Cy5-conjugated antibodies.

RESULTS

HSP90 expression was higher in melanomas than nevi (P < 0.0001) and higher in metastatic than primary specimens (P < 0.0001). No association was seen between high HSP90 expression and survival in the primary or metastatic patient subsets. In primary melanomas, high HSP90 expression was associated with higher Clark level (P = 0.0167) and increased Breslow depth (P < 0.0001).

CONCLUSIONS

HSP90 expression was significantly higher in tumors than nevi and was associated with disease progression, indicating that it might be a valuable drug target in melanoma, as well as a useful diagnostic marker. Prospective studies are needed to confirm the diagnostic role of HSP90, as well as the predictive role of HSP90 expression in patients treated with HSP90 inhibitors.

Evaluation of the prognostic significance of human kallikrein 8 protein expression levels in advanced ovarian cancer by using automated quantitative protein analysis

5581

Background: Kallikreins, a subgroup of the serine protease enzyme family, are considered important prognostic biomarkers in cancer. Here, we sought to determine the prognostic value of kallikrein 8 (hkl8) in ovarian cancer using a novel method of compartmentalized in situ protein analysis. Materials and Methods: A tissue array composed of 150 advanced stage ovarian cancers, uniformly treated with surgical debulking followed by platinum-paclitaxel combination chemotherapy, was constructed. For evaluation of kallikrein 8 protein expression, we used an immunofluorescence-based method of automated in situ quantitative measurement of protein analysis (AQUA). Results: Mean follow-up time of the cohort was 34.35 months. One hundred twenty six of 150 cases had sufficient tissue for AQUA analysis. There was association between tumor mask hk8 protein expression levels and clinicopathological variables including grade (p=0.0011), residual disease (p=0.0063),clinical response to chemotherapy (p=0.0346). In univariate survival analysis there was a correlation between hk8 tumor mask expression and 5 years progression-free survival. Low hk8 expression correlated with better outcome (top vs. bottom quartile, p = 0.0319). In multivariate survival analysis, adjusting for well-characterized prognostic variables, tumor hkl8 expression level retained its prognostic significance for disease free survival (95%CI: 0.341–1.027, p=0.0468). Conclusions: Human Kallikrein 8 is an adverse prognostic factor in patients with ovarian cancer.The possibilities that hK8 may be suitable candidate as diagnostic, prognostic marker and therapeutic target merit further investigation.

No significant financial relationships to disclose.

Assessment of PI3 kinase as a druggable target in melanoma

8521

Background: PI3 (phosphatidylinositol-3) kinase is central to a major intracellular signal transduction pathway that influences numerous cellular functions, including growth, differentiation and survival. Drugs that target PI3 kinase have demonstrated preclinical activity, and are undergoing further development. The PI3 kinase inhibitor, SF1126 is expected to enter clinical trials in 2007. The hallmarks for a valuable drug target include differential expression between normal and malignant cells and an association with disease progression. PI3 kinase expression has not been thoroughly evaluated in melanoma. We sought to determine the expression and prognostic value of PI3 kinase in a large cohort of primary and metastatic melanomas and to compare the expression with that of benign nevi. Methods: Tissue microarrays containing 548 melanomas and 540 benign nevi were employed to assess PI3 kinase expression. We used a novel method of in situ automated quantitative analysis (AQUA) of protein levels. We applied S100 conjugated to Cy3 to identify a melanoma tumor mask within a histospot, and measured PI3 kinase expression levels using Cy5 conjugated antibodies within the mask. Continuous AQUA scores were correlated with clinical and pathological variables. Results: PI3 kinase expression was higher in melanomas than in nevi by unpaired t-tests (p < 0.0001), and was significantly higher in metastatic than in primary specimens (p < 0.0001). High PI3 kinase scores were associated with Clark levels of IV-V (p = 0.0126), Breslow thickness > 2mm (p = 0.044) and absence of tumor infiltrating lymphocytes (p = 0.014). High PI3 kinase expression strongly correlated with decreased survival by Cox univariate analysis (p = 0.0024), but was not independent of disease stage. Conclusions: PI3 kinase expression is remarkably higher in malignant melanocytes than in benign nevi. Moreover, high PI3 kinase expression is associated with disease aggression, making PI3 kinase an attractive drug target for melanoma. This is the first large study assessing PI3 kinase levels in melanoma in a quantitative fashion. Assessment of the association between PI3 kinase levels and response to therapy is warranted.

No significant financial relationships to disclose.

Classification of renal cell carcinoma (RCC) based on the expression of VEGF and its receptors on tumor cells and microvessels: Identification of subsets with distinct patterns of expression, microvessel density, and outcome

15503

Background: The recent development of anti-angiogenic therapy for RCC has significantly improved the treatment of these often refractory tumors. However not all patients respond to therapy and assays for predicting outcome are needed. As a first step, we analyzed a retrospective cohort of tumors and assessed the ability of VEGF and VEGF receptors (VEGF-Rs) to classify tumors. Methods: Tissue microarray analysis of 330 RCC (clear cell = 234, papillary = 46) was performed using a novel method of Automated Quantitative Analysis (AQUA) of VEGF and VEGF-Rs (R1, R2 & R3) expression by fluorescent immunohistochemistry. The expression of VEGF and VEGF-Rs were separately quantitated within tumor cells, endothelial cells, and adjacent normal epithelium. Expression was recorded on a continuous scale and represents the average of two histocores. Results: VEGF and VEGF-Rs exhibited distinct expression patterns on tumor cells, tumor endothelium, and adjacent normal tissue. Within each component, expression of VEGF and its receptors was tightly correlated (all p-values < 0.001). Although tumor cell expression of VEGF did not correlate with microvessel density (p- value = 0.1848), tumor cell expression of R1 and R2 were strongly and inversely correlated with microvessel density [p-values <0.0001]. Unsupervised hierarchical clustering classified tumors according to the coordinated expression of VEGF and VEGF-Rs within the three tissue components - tumor (T), normal (N), and vessel (V). Tumors were classified into 5 clusters: 1) high T, N & V; 2) low T, high N & V; 3) high T, low N & V; 4) low T, N & V; and 5) high T & N for R3 only. Of these, clusters 1 and 3 exhibited poor survival, whereas clusters 2 and 4 contained tumors with high vessel densities. The distribution of clear cell and papillary tumors was not significantly different between clusters. Conclusions: VEGF and its receptors exhibit a complex pattern of coordinated expression in RCC. Clustering of tumors based on VEGF and VEGF-R in tissue components may provide a prognostic assay as well as a means for determining which tumors will respond to what anti-angiogenic therapies.

No significant financial relationships to disclose.

VEGF, VEGFR1, and VEGFR2 expression in melanoma

8520

Background: Metastatic melanoma is a chemoresistant disease with poor prognosis. Angiogenesis plays a role in progression and metastasis of melanoma. Identifying angiogenic molecules that are differentially expressed between benign and malignant tissues may enable us to create an assay to predict sensitivity to antiangiogenic agents, thus guiding selection of patients for treatment. VEGF signals through its receptor VEGFR1/flt-1 (R1) but is thought to mediate most of its angiogenic and proliferative effects through VEGFR2/flk-1/kdr (R2). In smaller melanoma studies, VEGF, R2 and less commonly R1 expression was associated with disease aggression. We characterized VEGF, R1, and R2 expression on a cohort of 540 nevi and 548 melanomas. Methods: We stained tissue microarrays to assess VEGF, R1, and R2 expression by automated quantitative analysis (AQUA), an objective method for analysis of protein levels. We used S100 to define pixels as melanoma (tumor mask) within the array spot, and measured intensity of VEGF, R1, and R2 expression using Cy5 conjugated antibodies within the mask. Results: VEGF, R1, and R2 expression was significantly higher in melanomas than in nevi by unpaired t-tests (p<0.0001). VEGF and R2 expression was higher in metastatic than primary specimens (p<0.0001). Differential expression of R1 between metastatic and primary specimens was less pronounced (p=0.0158). R2 expression correlated with Breslow depth > 2 mm (p=0.0129). Cox univariate analysis revealed an association between decreased survival and expression of VEGF (p= 0.0488) and R2 (p=0.0035); however, this was not independent of disease stage. Conclusions: VEGF, R1, and R2 expression is higher in malignant melanocytes than in their benign counterparts and higher in metastatic than primary specimens. This association with disease aggression underscores the importance of these proteins as therapeutic targets. Differential expression of R2 was found to be more significant than R1, supporting the belief that VEGF mediates its effects through R2 in malignancy. To our knowledge, this is the largest study to examine the VEGF pathway in melanoma. Future clinical trials of antiangiogenic agents in melanoma should include correlative serum and tissue assays of VEGF, R1, and R2 as biomarkers of response to therapy.

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Analysis of p53 protein expression levels on ovarian cancer tissue microarray using automated quantitative analysis elucidates prognostic patient subsets

BACKGROUND

p53 protein is regarded as a valuable prognostic marker in cancer with a potential use as a molecular target. Here, we sought to determine the prognostic value of p53 in ovarian cancer using a novel method of compartmentalized in situ protein analysis.

PATIENTS AND METHODS

A tissue array composed of 141 advanced stage ovarian cancers uniformly treated was constructed. For evaluation of p53 protein expression, we used an immunofluorescence-based method of automated in situ quantitative measurement of protein analysis (AQUA).

RESULTS

High nuclear p53 expression levels were associated with better outcome for overall survival (OS) (P = 0.0023) and disease-free survival (P = 0.0338) at 5-years. High cytoplasmic p53 expression levels were associated with better outcome for OS (P = 0.0002). In multivariable analysis, high nuclear and high cytoplasmic p53 level with International Federation of Gynecology and Obstetrics (FIGO) stage were the most significant predictor variables for OS and high nuclear p53 level with FIGO stage were the significant predictor variables for disease-free survival.

CONCLUSIONS

Assessment of the prognostic value of p53 protein levels using conventional immunohistochemistry is limited by the nonquantitative nature of the method. AQUA provides precise estimation of p53 protein levels and was able to elucidate the association of p53 protein levels and ovarian cancer prognosis.

Role of CCN2/CTGF in the proliferation of Mastomys enterochromaffin-like cells and gastric carcinoid development

Mastomys enterochromaffin-like (ECL) cell proliferation is initially gastrin driven, but once neoplasia develops, cells become gastrin autonomous. We hypothesized that CCN2 (CTGF), a mitogenic growth factor, may regulate ECL cell proliferation. A Mastomys GeneChip database was examined (dCHIP) to identify CCN2 expression levels. CCN2 in normal and tumor ECL cell preparations obtained using FACS (100 nM acridine orange) was examined by real-time PCR. CCN2 protein was identified in mucosal and ECL cell preparations by immunohistochemistry. Short-term cultured cells were stimulated with either CCN2 or CCN2 + EGF, and proliferation was measured (MTT assay). The ERK1/2 inhibitor PD-98059 (0.1-100 microM) was assessed in terms of CCN2 (1 ng/ml)-mediated proliferation and ERK1/2 phosphorylation. CCN2 transcript and protein was then examined in clinical gastric carcinoids. The ccn2 transcript was upregulated in tumor samples compared with the normal mucosa (+2.36-fold, P < 0.01). PCR demonstrated that ccn2 was not expressed in FACS-prepared (>98% pure) normal ECL cells but was elevated in tumor ECL cell fractions (41.3 +/- 10.7-fold). Immunostaining of the Mastomys gastric mucosa and FACS preparations confirmed that CCN2 protein was present in ECL tumors but not in normal ECL cells. Neither CCN2 nor CCN2 + EGF stimulated normal ECL cell proliferation. CCN2 stimulated tumor proliferation (EC50 approximately 0.01 ng/ml); EGF significantly augmented (P < 0.01) CCN2-induced tumor cell proliferation (EC50 = 20 pg/ml). PD-98059 inhibited CCN2-induced proliferation (-12 +/- 3%, P < 0.05) and ERK1/2 phosphorylation (-34 +/- 5%, P < 0.05) in tumor cells. In clinical samples, both CCN2 transcript and protein were elevated in gastrin-autonomous carcinoids (P < 0.02) compared with the normal mucosa. In conclusion, CCN2 may be a proliferative regulator of Mastomys ECL neoplastic proliferation once these cells become autonomous of gastrin regulation. Identification of CCN2 in gastric carcinoid tissue may be useful both as an indicator of ECL cell transformation and may define gastrin autonomy, a criteria of gastric carcinoid malignancy.

Automated quantitative analysis of DCC tumor suppressor protein in ovarian cancer tissue microarray shows association with β-catenin levels and outcome in patients with epithelial ovarian cancer

BACKGROUND

The deleted in colorectal cancer (DCC) protein, the product of DCC tumor suppressor gene, is frequently altered in cancer. Preclinical data demonstrate that DCC regulates beta-catenin levels. Here, we sought to determine the association of DCC with beta-catenin protein levels, clinicopathological parameters and patient outcome in ovarian cancer using a method of in situ compartmentalized protein analysis.

METHODS

A tissue array composed of 150 advanced-stage ovarian cancers, treated with surgical debulking and platinum-paclitaxel (Taxol) combination chemotherapy, was constructed. For evaluation of protein expression, we used an immunofluorescence-based method of automated in situ quantitative measurement of protein analysis (AQUA).

RESULTS

One hundred and twelve patients (74%) had sufficient tissue for AQUA. The median follow-up time for the entire cohort was 33 months. Patients with low nuclear DCC expression had a 3-year progression-free survival (PFS) rate of 0% compared with 33% of those with high DCC expression (P = 0.0067). In multivariate analysis, low nuclear DCC expression level retained its prognostic significance for PFS. Between DCC and beta-catenin, a significant relationship was found, where tumors with low DCC had low beta-catenin and vice versa (P = 0.003).

CONCLUSIONS

Low nuclear DCC levels predict for poor patient outcome in epithelial ovarian cancer. DCC may exert its antitumor function, in part, through regulation of beta-catenin levels.

β-Catenin Functions Mainly as an Adhesion Molecule in Patients with Squamous Cell Cancer of the Head and Neck

BACKGROUND

beta-catenin, depending on subcellular localization, plays a dual role in carcinogenesis: as a signaling factor (in the nucleus) and as an adhesion molecule (in cell membrane). In this study, we sought to determine the role of beta-catenin in head and neck carcinogenesis.

METHODS

First, we studied the incidence of mutations of beta-catenin in a cohort of 60 head and neck squamous cell cancers (HNSCC). We subsequently evaluated the protein expression levels of beta-catenin in a cohort of oropharyngeal squamous cell cancer tissue microarray using a novel in situ method of quantitative protein analysis and correlated those with cyclin D1 levels and clinical and pathologic data.

RESULTS

The mean follow-up time for survivors was 45 months and for all patients was 35 months. We found no mutations in the cohort of 60 HNSCC. beta-catenin displayed primarily membranous expression pattern. Patients with high tumor-node-metastasis stage were more likely to have high expression of beta-catenin (P = 0.040). Patients with low beta-catenin expression had a local recurrence rate of 79% compared with 29% for patients with high beta-catenin tumors (P = 0.0021). Univariate Cox regression revealed a hazard ratio for low beta-catenin tumors of 3.6 (P = 0.004). Kaplan-Meier analysis showed that patients with low beta-catenin expressing tumors trended toward worse 5-year disease-free survival (P = 0.06). In multivariate analysis, only beta-catenin expression status was an independent prognostic factor (P = 0.044) for local recurrence. Tumors with high beta-catenin had low cyclin D1 and vice versa (P = 0.007).

CONCLUSIONS

The absence of activating beta-catenin mutations combined with the inverse correlation between beta-catenin levels with cyclin D1 levels and outcome suggest that beta-catenin mainly functions as an adhesion and not signaling molecule in HNSCC.

Amplification of tissue by construction of tissue microarrays

Tissue microarrays are a method of relocating tissue from conventional histologic paraffin blocks in a manner that tissue from multiple patients or blocks can be seen on the same slide. This is done by using a needle to biopsy a standard histologic section and placing the core into an array on a recipient paraffin block. This technique allows maximization of tissue resources by analysis of small core biopsies of blocks, rather than complete sections. Using this technology, a carefully planned array can be constructed using cases from pathology tissue block archives, and a 20-year survival analysis can be done on a cohort of 600 or more patients using only a few microliters of antibody in a single experiment. Furthermore, this cohort can be analyzed thousands of times with different reagents as a result of judicious sectioning of the array block. This review describes this process and discusses the issues of representative sampling in heterogeneous lesions, the issue of antigen preservation, and some technical strategies and methods of array construction. In summary, this technique can provide a highly efficient, high-throughput mechanism for evaluation of protein expression in large cohorts. It has the potential for allowing validation of new genes at a speed comparable to the rapid rate of gene discovery afforded by DNA microarrays.

Beta-catenin dysregulation in thyroid neoplasms: down-regulation, aberrant nuclear expression, and CTNNB1 exon 3 mutations are markers for aggressive tumor phenotypes and poor prognosis

beta-catenin has a role in cell adhesion and Wnt signaling. It is mutated or otherwise dysregulated in a variety of human cancers. In this study we assess beta-catenin alteration in 145 thyroid tumors samples from 127 patients. beta-catenin was localized using immunofluorescence and mutational analysis was performed by single-strand conformational polymorphism. Membrane beta-catenin expression was decreased in eight of 12 (66%) adenomas and in all 115 carcinomas (P: < 0.0001). Among carcinomas, reduced membrane beta-catenin was associated with progressive loss of tumor differentiation (P: < 0.0001). CTNNB1 exon 3 mutations and nuclear beta-catenin localization were restricted to poorly differentiated [7 of 28 (25%) and 6 of 28 cases (21.4%), respectively] or undifferentiated carcinomas [19 of 29 (65.5%) and 14 of 29 (48.3%) cases, respectively]. Poorly differentiated tumors always featured mutations involving Ser and Thr residues and were characterized by Thr to Ile amino acid substitutions (P: = 0.0283). The association between CTNNB1 exon 3 mutations and aberrant nuclear immunoreactivity (P: = 0.0020) is consistent with Wnt activation because of stabilizing beta-catenin mutations. Low membrane beta-catenin expression as well as its nuclear localization or CTNNB1 exon 3 mutations are significantly associated with poor prognosis, independent of conventional prognostic indicators for thyroid cancer but not of tumor differentiation. Analysis of beta-catenin dysregulation may be useful to objectively subtype thyroid neoplasms and more accurately predict outcomes.

Tissue microarray: a new technology for amplification of tissue resources

Tissue microarrays are a method of harvesting small disks of tissue from a range of standard histologic sections and placing them in an array on a recipient paraffin block such that hundreds of cases can be analyzed simultaneously. This technique allows maximization of tissue resources by analysis of small-core biop sies of blocks, rather than complete sections. Using this technology, a carefully planned array can be constructed with cases from pathology tissue block archives, such that a 20-year survival analysis can be performed on a cohort of 600 or more patients by use of only a few microliters of antibody in a single experiment. The reflex criticism of this technique is that the tissue analyzed is not representative, especially in antigens with heterogeneous staining patterns. This review addresses this issue, as well as the issue of antigen preservation or durability, which validates construction of arrays from archives. Strategies and methods of construction and analysis of the arrays are discussed, as well as some other unusual array applications. This technique can provide a highly efficient, high-throughput mechanism for evaluation of protein expression in large cohorts. It has the potential to allow validation of new genes at a speed comparable to the rapid rate of gene discovery afforded by DNA microarrays.

Validation of tissue microarray technology in breast carcinoma

The recent development of tissue microarray technology has potentiated large-scale retrospective cohort studies using archival formalin-fixed, paraffin-embedded tissues. A major obstacle to broad acceptance of microarrays is that they reduce the amount of tissue analyzed from a whole tissue section to a disk, 0.6 mm in diameter, that may not be representative of the protein expression patterns of the entire tumor. In this study, we examine the number to disks required to adequately represent the expression of three common antigens in invasive breast carcinoma--estrogen receptor, progesterone receptor, and the Her2/neu oncogene--in 38 cases of invasive breast carcinoma. We compared the staining of 2 to 10 microarray disks and the whole tissue sections from which they were derived and determined that analysis of two disks is comparable to analysis of a whole tissue section in more than 95% of cases. To evaluate the potential for using archival tissue in such arrays, we created a breast cancer microarray of 8 to 11 cases from each decade beginning in 1932 to the present day and evaluated the antigenicity of these markers and others. This array demonstrates that many proteins retain their antigenicity for more than 60 years, thus validating their study on archival tissues. We conclude that the tissue microarray technique, with 2-fold redundancy, is a valuable and accurate method for analysis of protein expression in large archival cohorts.

Aneurysmal bone cyst of the spine with familial incidence

STUDY DESIGN

A report of two cases of aneurysmal bone cysts of the spine occurring in a father and daughter.

OBJECTIVE

To present an unusual finding of familial incidence of aneurysmal bone cyst and review the literature.

SUMMARY OF BACKGROUND DATA

Aneurysmal bone cysts are benign, expanding, locally aggressive lesions. Up to 20% of cases involve the spine. The cause of primary aneurysmal bone cysts remains unclear. There have been three previous reports of a familial incidence supporting the importance of a hereditary component in the cause of aneurysmal bone cysts.

METHODS

A 36-year-old man and a 7-year-old girl were diagnosed with aneurysmal bone cyst involving the spine by clinical manifestations, radiographic features, and histologic evaluation.

RESULTS

The father remains recurrence- and symptom-free 6 years after primary resection. Five months after surgery, the daughter was found to have recurrent disease by magnetic resonance imaging and underwent a second procedure within 1 year of the primary resection.

CONCLUSION

The occurrence of a primary aneurysmal bone cyst in two family members, occurring at adjacent vertebral levels, is suggestive of a hereditary component to the formation of primary aneurysmal bone cyst.

Met expression is associated with poor outcome in patients with axillary lymph node negative breast carcinoma

BACKGROUND

Activation of Met, the receptor for scatter factor/hepatocyte growth factor, is associated with mitogenesis, motogenesis, and decreased cell adhesion. Elevated expression of Met has been shown in advanced cases of carcinoma of the prostate, stomach, pancreas, and thyroid. The authors previously demonstrated that Met expression is an independent prognostic marker associated with decreased survival in patients with breast carcinoma.

METHODS

Expression of Met in 113 archival breast carcinoma specimens from patients with axillary lymph node negative invasive ductal carcinoma was evaluated using a standard immunoperoxidase technique. Cases were scored by two pathologists using an H-score algorithm and then analyzed for correlation with known prognostic factors and survival.

RESULTS

Expression of Met showed a bimodal distribution with 25% of cases showing high levels of expression. In contrast to previous studies, the results of the current study showed a significant association between Met expression and nuclear and histologic grade. The 5-year survival rate for Met negative patients with tumors with low Met expression was 95% in this cohort, compared with 80% for patients with tumors showing high Met expression. Patients whose tumors had a high level of Met expression were found to have a 5-year relative risk (RR) of dying of metastatic disease of 5.05 (P = 0.03) independent of patient age and tumor size. Combined analysis of Met and nuclear grade resulted in a marked increase in independent predictive value (RR = 33.4; P < 0.01).

CONCLUSIONS

The results of the current study found that high levels of Met expression were associated with death due to metastatic disease in patients with axillary lymph node negative breast carcinoma. Expression of Met may be a useful prognostic indicator of more aggressive disease in patients whose prognosis is not easily stratified by current histopathologic markers.

A high number of tumor free axillary lymph nodes from patients with lymph node negative breast carcinoma is associated with poor outcome

BACKGROUND

Lymph node metastasis is the oldest and most reliable prognostic indicator in breast carcinoma. In the absence of tumor metastasis, draining lymph nodes can undergo hyperplasia, resulting in increases in the number and size of detectable lymph nodes. The prognostic value of this process has never been established. Lymph node negative breast carcinoma provides a unique opportunity to study the downstream effects of increased lymphatic drainage and lymph node hyperplasia.

METHODS

The authors studied 290 cases of lymph node negative breast carcinoma and provided patients with a median of 103 months of follow-up. The number of tumor free lymph nodes in ipsilateral axillary resections, as well as 10 traditional histopathologic markers, were analyzed for their prognostic value.

RESULTS

The cohort was divided into quartiles according to the number of tumor negative lymph nodes. The 5-year survival for patients with 20 or more tumor free lymph nodes (top quartile) was 84.7%, compared with 96.3% for patients with fewer than 20 tumor free lymph nodes. The 5-year relative risk of dying of metastatic disease in the top quartile was 3.61 (95% confidence interval, 1.37-9.52, P = 0.01), independent of necrosis, tumor size, patient age, nuclear and histologic grade, lymphocytic infiltrate, and lymphovascular invasion. The absolute lymph node number was highly associated with the presence of necrosis in invasive tumor.

CONCLUSIONS

The number of tumor free lymph nodes is a novel, independent predictor of aggressive disease in cases of lymph node negative breast carcinoma. This finding may be a biologic function of host-derived, and possibly tumor-derived, lymphangiogenic cytokines.

Met expression is associated with poor outcome in patients with axillary lymph node negative breast carcinoma

BACKGROUND

Activation of Met, the receptor for scatter factor/hepatocyte growth factor, is associated with mitogenesis, motogenesis, and decreased cell adhesion. Elevated expression of Met has been shown in advanced cases of carcinoma of the prostate, stomach, pancreas, and thyroid. The authors previously demonstrated that Met expression is an independent prognostic marker associated with decreased survival in patients with breast carcinoma.

METHODS

Expression of Met in 113 archival breast carcinoma specimens from patients with axillary lymph node negative invasive ductal carcinoma was evaluated using a standard immunoperoxidase technique. Cases were scored by two pathologists using an H-score algorithm and then analyzed for correlation with known prognostic factors and survival.

RESULTS

Expression of Met showed a bimodal distribution with 25% of cases showing high levels of expression. In contrast to previous studies, the results of the current study showed a significant association between Met expression and nuclear and histologic grade. The 5-year survival rate for Met negative patients with tumors with low Met expression was 95% in this cohort, compared with 80% for patients with tumors showing high Met expression. Patients whose tumors had a high level of Met expression were found to have a 5-year relative risk (RR) of dying of metastatic disease of 5.05 (P = 0.03) independent of patient age and tumor size. Combined analysis of Met and nuclear grade resulted in a marked increase in independent predictive value (RR = 33.4; P < 0.01).

CONCLUSIONS

The results of the current study found that high levels of Met expression were associated with death due to metastatic disease in patients with axillary lymph node negative breast carcinoma. Expression of Met may be a useful prognostic indicator of more aggressive disease in patients whose prognosis is not easily stratified by current histopathologic markers.

Unresponsiveness to 2,4-dinitro-1-fluoro-benzene after treatment with monoclonal antibodies to leukocyte function-associated molecule-1 and intercellular adhesion molecule-1 during sensitization

We have investigated whether hapten-specific unresponsiveness could be induced if the interaction between LFA-1 (CD11a/CD18) and intercellular adhesion molecule-1 (CD54) was disrupted by blocking mAbs given to mice during sensitization with 2,4-dinitro-1-fluorobenzene. An extended period of more than 11 days between the last i.p. injection of mAb and challenge was chosen to ensure that the mAb did not persist in the animals at the time of hapten challenge, as analyzed by flow cytometry and immunohistochemistry. The contact sensitivity response was significantly reduced (p &lt; 0.001) when a combination of mAb FD441.8 against LFA-1 and mAb YNI/1.7.4 against intercellular adhesion molecule-1 was given during the sensitization phase compared with normal rat IgG-treated control animals. Furthermore, the animals were resistant to resensitization to the same hapten. This hyporesponsiveness was hapten specific, since the contact sensitivity reaction of mAb-treated mice to oxazolone was the same as that of normal rat IgG-treated control animals. Together these data indicate that inhibition of LFA-1/intercellular adhesion molecule-1 mediated interactions between APCs and T cells during sensitization induced long term, Ag-specific, hyporesponsiveness of mice to the hapten 2,4-dinitro-1-fluoro-benzene.

Unresponsiveness to 2,4-dinitro-1-fluoro-benzene after treatment with monoclonal antibodies to leukocyte function-associated molecule-1 and intercellular adhesion molecule-1 during sensitization

We have investigated whether hapten-specific unresponsiveness could be induced if the interaction between LFA-1 (CD11a/CD18) and intercellular adhesion molecule-1 (CD54) was disrupted by blocking mAbs given to mice during sensitization with 2,4-dinitro-1-fluorobenzene. An extended period of more than 11 days between the last i.p. injection of mAb and challenge was chosen to ensure that the mAb did not persist in the animals at the time of hapten challenge, as analyzed by flow cytometry and immunohistochemistry. The contact sensitivity response was significantly reduced (p < 0.001) when a combination of mAb FD441.8 against LFA-1 and mAb YNI/1.7.4 against intercellular adhesion molecule-1 was given during the sensitization phase compared with normal rat IgG-treated control animals. Furthermore, the animals were resistant to resensitization to the same hapten. This hyporesponsiveness was hapten specific, since the contact sensitivity reaction of mAb-treated mice to oxazolone was the same as that of normal rat IgG-treated control animals. Together these data indicate that inhibition of LFA-1/intercellular adhesion molecule-1 mediated interactions between APCs and T cells during sensitization induced long term, Ag-specific, hyporesponsiveness of mice to the hapten 2,4-dinitro-1-fluoro-benzene.

Defective phosphorylation and hyaluronate binding of CD44 with point mutations in the cytoplasmic domain

CD44 is a cell surface adhesion molecule that plays a role in leukocyte extravasation, leukopoiesis, T lymphocyte activation, and tumor metastasis. The principal known ligand for CD44 is the glycosaminoglycan hyaluronate, (HA), a major constituent of extracellular matrices. CD44 expression is required but is not sufficient to confer cellular adhesion to HA, suggesting that the adhesion function of the receptor is regulated. We recently demonstrated that CD44 in primary leukocytes is phosphorylated in a cell type- and activation state-dependent fashion. In this study we demonstrate that serines 325 and 327 within the cytoplasmic domain of CD44 are required for the constitutive phosphorylation of CD44 in T cells. Furthermore, we demonstrate that cells expressing mutated CD44 containing a serine to glycine substitution at position 325 or a serine to alanine substitution at amino acid 327 are defective in HA binding, CD44-mediated adhesion of T cells to smooth muscle cells, as well as ligand-induced receptor modulation. The effect of these mutations can be partially reversed by a monoclonal anti-CD44 antibody that enhances CD44-mediated HA binding.

CD44 is necessary for optimal contact allergic responses but is not required for normal leukocyte extravasation

The in vivo administration of certain monoclonal antibodies (mAbs) against the adhesion receptor, CD44, into normal mice induces both a modulation of CD44 from the surface of peripheral lymphocytes, and a concomitant increase in the amount of soluble CD44 in the serum. CD44-negative lymphocytes isolated from anti-CD44-treated mice exhibit normal homing patterns upon adoptive transfer, and are capable of reexpressing CD44 upon activation. The treatment of haptensensitized mice with anti-CD44 mAb inhibits their ability to mount a cutaneous delayed-type hypersensitivity (DTH) response within the first 24 h after hapten challenge. This inhibition reflects a block in both the edema and leukocyte infiltration of the cutaneous site of DTH, whereas the extravasation and accumulation of leukocytes in the draining lymph nodes progress normally. After 72 h, the leukocytes that extravasate into the site of antigen challenge express CD44. These results indicate that CD44 is not necessary for normal leukocyte circulation but is required for leukocyte extravasation into an inflammatory site involving nonlymphoid tissue.

Reduced contact sensitivity reactions in mice treated with monoclonal antibodies to leukocyte function-associated molecule-1 and intercellular adhesion molecule-1

We have investigated the effect of the administration of mAb against leukocyte function-associated molecule-1 (CD11a/CD18) and intercellular adhesion molecule-1 (CD54) on the delayed-type hypersensitivity reaction in 2,4-dinitro-1-fluorobenzene-sensitized CD2F1 mice. An i.p. injection of the mAb FD441.8 against CD11a at the time of ear challenge led to an almost complete inhibition of ear swelling compared with control animals. Administration of anti-CD54 mAb, 3E2 or YN1/1.7.4, before challenge, resulted in approximately 50% reduction of the delayed-type hypersensitivity response. The decrease in ear swelling reflected a profound inhibition of the edema and the cell infiltration in ears from animals treated with anti-CD11a, and a partial inhibition with anti-CD54 treatment. In addition, the threefold increase in the number of cells recovered from the draining lymph nodes 24 h after challenge in sensitized mice injected with normal IgG was ablated in mice treated with anti-CD11a and partially reduced in anti-CD54-treated animals. Immunohistochemistry and flow cytometry analysis demonstrated that the in vivo administered anti-CD11a mAb was associated with the surface of the majority of the cells in the lymph nodes 24 h after injection and challenge, whereas the anti-intercellular adhesion molecule-1 mAb reacted preferentially with the vascular endothelium. It is concluded that leukocyte function-associated molecule-1 and intercellular adhesion molecule-1 contribute to the generation of an optimal delayed-type hypersensitivity response.

Reduced contact sensitivity reactions in mice treated with monoclonal antibodies to leukocyte function-associated molecule-1 and intercellular adhesion molecule-1

We have investigated the effect of the administration of mAb against leukocyte function-associated molecule-1 (CD11a/CD18) and intercellular adhesion molecule-1 (CD54) on the delayed-type hypersensitivity reaction in 2,4-dinitro-1-fluorobenzene-sensitized CD2F1 mice. An i.p. injection of the mAb FD441.8 against CD11a at the time of ear challenge led to an almost complete inhibition of ear swelling compared with control animals. Administration of anti-CD54 mAb, 3E2 or YN1/1.7.4, before challenge, resulted in approximately 50% reduction of the delayed-type hypersensitivity response. The decrease in ear swelling reflected a profound inhibition of the edema and the cell infiltration in ears from animals treated with anti-CD11a, and a partial inhibition with anti-CD54 treatment. In addition, the threefold increase in the number of cells recovered from the draining lymph nodes 24 h after challenge in sensitized mice injected with normal IgG was ablated in mice treated with anti-CD11a and partially reduced in anti-CD54-treated animals. Immunohistochemistry and flow cytometry analysis demonstrated that the in vivo administered anti-CD11a mAb was associated with the surface of the majority of the cells in the lymph nodes 24 h after injection and challenge, whereas the anti-intercellular adhesion molecule-1 mAb reacted preferentially with the vascular endothelium. It is concluded that leukocyte function-associated molecule-1 and intercellular adhesion molecule-1 contribute to the generation of an optimal delayed-type hypersensitivity response.

Variations in the cytoskeletal interaction and posttranslational modification of the CD44 homing receptor in macrophages

Murine CD44 is a cell surface glycoprotein that is thought to play a role in leukocyte migration. We studied the structure and expression of CD44 on two populations of macrophages: those that reside in the peritoneum of unprimed mice, and those that have been elicited to migrate into the peritoneum by the intraperitoneal injection of agents that cause localized inflammatory responses. Our studies reveal structural variations in both the extracellular and intracellular domains of CD44 expressed by these two macrophage populations. The form of CD44 in elicited macrophages has an apparent molecular mass that is approximately 5 kD greater and more heterogenous than that in resident macrophages. This structural changes is posttranslational, extracellular, and apparently reflects increases in N-linked glycosylation. It is also specific for CD44 and does not occur with several other glycoproteins examined. This novel regulation of glycosylation may play an important role in the ability of CD44 to bind to different substrates, particularly lectin-like ligands. In addition, we demonstrate that CD44 in resident macrophages is divided into two pools, one containing nonphosphorylated, cytoskeletally associated CD44, and one containing phosphorylated, unassociated CD44. In contrast, CD44 on the surface of elicited macrophages does not associate with the cytoskeleton. The attachment of CD44 to the cytoskeleton involves either direct or indirect association with actin. The regulated association of CD44 with the cytoskeleton suggests that it may influence or be influenced by macrophage mobility.

High levels of CD44 expression distinguish virgin from antigen-primed B cells

The in vitro polyclonal stimulation of B cells through their surface immunoglobulin (Ig) induces substantial increases in CD44 protein levels within 24 hours, whereas other stimuli (e.g., lipopolysaccharide, phorbol 12,13 dibutyrate, and interleukin 4) fail to significantly upregulate CD44. The marked increase in CD44 protein expression on anti-Ig-treated B lymphocytes correlates with an increase in CD44-specific mRNA. Cell sorting experiments with B cells isolated from trinitrophenyl-keyhole limpet hemocyanin-immunized mice demonstrate that both short-term antigen-specific, IgG-secreting cells and long-term antigen-primed B cells are exclusively CD44high. We speculate that the rapid and sustained increase in CD44 expression mediated by surface Ig stimulation may alter the homing properties of antigen-primed B cells.

Antimicrobial polymers

A number of carboxyl-containing ethylene copolymers have been prepared which exhibit long term antibacterial and antifungal properties. These materials containing antimicrobial agents bound to the copolymer backbone as carboxylate salts, have been tested for their applicability to hospital products as a means of providing "self-sanitizing" articles. Tests have shown that these materials, although not bactericidal, do inhibit microbial growth. Investigations of the compatibility of these polymers with commodity polymers have been made and water emulsions of the polymers have been tested for applicability as components of product protectant coatings.