Synaptonemal complex protein 3 is a prognostic marker in cervical cancer

Synaptonemal complex protein 3 (SCP3), a member of Cor1 family, is up-regulated in various cancer cells; however, its oncogenic potential and clinical significance has not yet been characterized. In the present study, we investigated the oncogenic role of SCP3 and its relationship with phosphorylated AKT (pAKT) in cervical neoplasias. The functional role of SCP3 expression was investigated by overexpression or knockdown of SCP3 in murine cell line NIH3T3 and human cervical cancer cell lines CUMC6, SiHa, CaSki, and HeLa both in vitro and in vivo. Furthermore, we examined SCP3 expression in tumor specimens from 181 cervical cancer and 400 cervical intraepithelial neoplasia (CIN) patients by immunohistochemistry and analyzed the correlation between SCP3 expression and clinicopathologic factors or survival. Overexpression of SCP3 promoted AKT-mediated tumorigenesis both in vitro and in vivo. Functional studies using NIH3T3 cells demonstrated that the C-terminal region of human SCP3 is important for AKT activation and its oncogenic potential. High expression of SCP3 was significantly associated with tumor stage (P = 0.002) and tumor grade (P<0.001), while SCP3 expression was positively associated with pAKT protein level in cervical neoplasias. Survival times for patients with cervical cancer overexpressing both SCP3 and pAKT (median, 134.0 months, n = 68) were significantly shorter than for patients with low expression of either SCP3 or pAKT (161.5 months, n = 108) as determined by multivariate analysis (P = 0.020). Our findings suggest that SCP3 plays an important role in the progression of cervical cancer through the AKT signaling pathway, supporting the possibility that SCP3 may be a promising novel cancer target for cervical cancer therapy.

Profiling of phospho-AKT, phospho-mTOR, phospho-MAPK and EGFR in non-small cell lung cancer

Activation of numerous pathways has been documented in non-small cell lung cancer (NSCLC). Epidermal growth factor receptor (EGFR) has emerged as a common therapeutic target. The mitogen-activated protein kinase (MAPK) and AKT signaling pathways are downstream of EGFR and deregulated via genetic and epigenetic mechanisms in many human cancers. We evaluated selected markers in the EGFR pathway with reference to outcome. Tissues from 220 cases of NSCLC patients presented in a tissue microarray were assayed with immunohistochemistry for phosphorylated AKT, phosphorylated MAPK, phosphorylated mTOR, and EGFR and then quantified by automated image analysis. Individually, the biomarkers did not predict. Combined as ratios, p-mTOR/p-AKT, and p-MAPK/EGFR function as prognostic markers of survival (p=0.008 and p=0.029, respectively), however, no significance was found after adjustment (p=0.221, p=0.103). The sum of these ratios demonstrates a stronger correlation with survival (p<0.001) and remained statistically significant after adjustment (p=0.026). The algebraic combination of biomarkers offer the capacity to understand factors that predict outcome better than current approaches of evaluating biomarkers individually or in pairs. Our results show the sum of p-mTOR/p-AKT and p-MAPK/EGFR is a potential predictive marker of survival in NSCLC patients.

Phenotypic Stability of Mature Dendritic Cells Tuned by TLR or CD40 to Control the Efficiency of Cytotoxic T Cell Priming

It is generally accepted that after stimulation immature DCs turn into mature DCs, which present exogenous antigens together with their MHC class I molecules and then activate the antigen-specific CTLs. Although both TLR and CD40 stimulation appeared to provide the same effects on DC maturation, CD40-dependent CTL activation is much more potent than CTL activation through LPS stimulation. Despite their different outcomes, the factors that lead mature DCs to different functions remain largely undefined. In this study, we defined the transient maturation and subsequent deactivation of DCs by TLR stimuli, including those by LPS and CpG-ODN. In contrast, CD40 stimulation induced stable mature DCs that elicited sufficient CTL proliferation. The deactivated DCs, which we defined as "expired DCs," were phenotypically similar to immature DCs, except for their phenotype stability, MHC class I expression level and IL-10 production. Moreover, the functions of expired DCs were comparable to those of immature DCs in terms of CTL induction and tolerogenicity. These results may provide an explanation for the role of CD40 stimulation in antigen-specific CTL induction.

Synaptonemal complex protein 3 as a novel prognostic marker in early stage non-small cell lung cancer

Synaptonemal complex protein 3 is a marker for cell transformation that has prognostic significance in various cancers. However, the prognostic significance of synaptonemal complex protein 3 has not been studied in non-small cell lung cancer. To investigate the potential correlation between synaptonemal complex protein 3 and various clinicopathologic parameters, we assessed the expression of synaptonemal complex protein 3 in archival tumor tissues from 258 patients with non-small cell lung cancer by immunohistochemical staining. By immunofluorescence, synaptonemal complex protein 3 was detected in both the cytoplasmic and nuclear fractions of NCI-H1299 cell. In tumor samples, synaptonemal complex protein 3 is detected as cytoplasmic expression pattern and observed in 50 clinical samples (19.4%) by immunohistochemical staining. Synaptonemal complex protein 3 expression was correlated with T status (P = .008), lymph node metastasis (P = .010), tumor types (P = .019), and pleural invasion (P = .005). In multivariate analysis of patients with early stage disease, increased synaptonemal complex protein 3 expression predicted worse overall survival in early stage (stage I and II) with pT1 status (P = .041). These results suggest that positive synaptonemal complex protein 3 expression is a portent of poor outcome and may be a potential biomarker in the early stages of the non-small cell lung cancer for survival and may provide clues in the identification of patients for adjuvant therapy.

Cell-cycle control in urothelial carcinoma: large-scale tissue array analysis of tumor tissue from Maine and Vermont

BACKGROUND

Cell-cycle proteins are important predictive markers in urothelial carcinoma but may also exhibit exposure-specific heterogeneity.

METHODS

Tumor tissue from 491 bladder cancer cases enrolled in the Maine and Vermont component of the New England Bladder Cancer Study was assembled as tissue microarrays and examined for aberrant expression of p53, p63, p16, cyclin D1, Rb, and Ki-67. The association between expression and histopathology, demographics, and cigarette smoking was examined using χ(2) tests, multivariable Poisson, and multinomial regression models.

RESULTS

We found that overexpression of p53 and Ki-67 was associated with high-stage/grade tumors [relative risk (RR), 1.26; P(trend) = 0.003; and RR, 3.21; P(trend) < 0.0001, respectively], whereas expression of p63 and p16 was decreased in high-stage/grade tumors (RR, 0.52; P(trend) < 0.0001; and RR, 0.88; P(trend) = 0.04, respectively). No significant aberrations of cell-cycle proteins were identified using various smoking variables and multiple statistical models.

CONCLUSION

The results of this population-based study of histologically confirmed urothelial carcinomas show significant aberration of cell-cycle proteins p53, p63, p16, and Ki-67, but not Rb or cyclin D1. p53 showed the most significant heterogeneity with respect to tumor stage and grade, especially when stratified for different staining intensities using novel digital image analysis techniques. Our findings do not support that smoking modifies expression of cell-cycle proteins.

IMPACT

Our study shows significant heterogeneity in the expression of key cell-cycle proteins that are associated with disease progression in bladder cancer. Further studies may lead to the identification of biomarkers and their multiplexed interactions as useful prognostic and therapeutic targets.

Evaluation of lymphangiogenic factors, vascular endothelial growth factor D and E-cadherin in distinguishing inflammatory from locally advanced breast cancer

BACKGROUND

Inflammatory breast cancer (IBC) is an aggressive form of breast cancer that on presentation resembles locally advanced breast cancer (LABC). This study identified molecular features of IBC and LABC to investigate pathogenesis.

MATERIALS AND METHODS

This study involved 100 IBC cases identified in a national IBC registry and 107 non-IBC LABC cases from the National Cancer Institute's Cooperative Breast Cancer Tissue Resource (CBCTR). Vascular endothelial growth factor D (VEGF-D) and E-cadherin levels and lymphatic vessel density (LVD) measured by podoplanin staining were examined by immunohistochemistry on paraffin-embedded tumor specimens. Intralymphatic tumor emboli (ILTE) were assessed in IBC and non-IBC tumors. IBC cases diagnosed by clinicians but not meeting the case definitions of the American Joint Committee on Cancer (AJCC) or the Surveillance, Epidemiology and End Results (SEER) Program of the National Cancer Institute (NCI)(designated atypical IBC) were compared with AJCC- and/or SEER-defined cases (designated classic IBC).

RESULTS

E-cadherin levels were significantly higher in classic IBC cases compared with non-IBC cases (P = .031), whereas compared with classic IBC, patients with non-IBC LABC had significantly higher LVD (P = .0017) and VEGF-D levels (P < .0001). ILTE was marginally greater in classic IBC than in non-IBC (P = .046). The profile of laboratory values in atypical IBC cases more closely resembled those fitting classic IBC than LABC.

CONCLUSION

E-cadherin levels, LVD, VEGF-D expression, and to a lesser extent, ILTE differed between classic IBC and non-IBC LABC. The similarity of laboratory results between atypical IBC and classic IBC vs. LABC suggests the need for broadening both the AJCC and SEER case definitions for this disease.

Ascitic fluid due to type II herpes simplex virus infection: report of a case with immunocytochemical confirmation

Herpes simplex virus (HSV) infection is usually observed in the oral cavity and external genitals, and HSV peritonitis is extremely rare. Herein, we report a case of type II HSV peritonitis successfully diagnosed by ascitic cytology. A 66-year-old Japanese man, who had been treated with steroid inhalation for 5 years due to chronic obstructive pulmonary disease, was suspected to have acute cholecystitis. Laparoscopic cholecystectomy and intraoperative cytological examination of ascitic fluid were performed. Cytological study of ascitic fluid revealed that abundant granular cell debris, degenerative cells and apoptotic bodies were present, as well as some single or multinucleated cells with ground glass nuclei. However, vivid mesothelial cells were rarely seen. Immunocytochemical staining for type II HSV was positive in single or multinucleated cells with ground glass nuclei. Therefore, a diagnosis of type II HSV peritonitis was made. This is the first reported case of type II HSV peritonitis successfully diagnosed by ascitic cytology. This report highlights that the presence of abundant cell debris, degenerative cells and apoptotic bodies, and the absence of vivid mesothelial cells are the key cytological findings to suspect HSV peritonitis, and the diagnosis can be confirmed by careful surveillance for characteristic nuclear findings of single or multinucleated cells. The frequency of opportunistic infection is increased because of the increased numbers of iatrogenic immunocompromised patients as seen in this case, therefore, cytological examination is a useful method for early detection of the causative agent of peritonitis including HSV.

Global gene expression profiling and validation in esophageal squamous cell carcinoma and its association with clinical phenotypes

PURPOSE

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor with poor prognosis. Understanding molecular changes in ESCC will enable identification of molecular subtypes and provide potential targets for early detection and therapy.

EXPERIMENTAL DESIGN

We followed up a previous array study with additional discovery and confirmatory studies in new ESCC cases by using alternative methods. We profiled global gene expression for discovery and confirmation, and validated selected dysregulated genes with additional RNA and protein studies.

RESULTS

A total of 159 genes showed differences with extreme statistical significance (P < E-15) and 2-fold differences or more in magnitude (tumor/normal RNA expression ratio, N = 53 cases), including 116 upregulated and 43 downregulated genes. Of 41 genes dysregulated in our prior array study, all but one showed the same fold change directional pattern in new array studies, including 29 with 2-fold changes or more. Alternative RNA expression methods validated array results: more than two thirds of 51 new cases examined by real-time PCR (RT-PCR) showed 2-fold differences or more for all seven genes assessed. Immunohistochemical protein expression results in 275 cases which were concordant with RNA for five of six genes.

CONCLUSION

We identified an expanded panel of genes dysregulated in ESCC and confirmed previously identified differentially expressed genes. Microarray-based gene expression results were confirmed by RT-PCR and protein expression studies. These dysregulated genes will facilitate molecular categorization of tumor subtypes and identification of their risk factors, and serve as potential targets for early detection, outcome prediction, and therapy.

Global gene expression profiling and validation in esophageal squamous cell carcinoma and its association with clinical phenotypes

PURPOSE

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor with poor prognosis. Understanding molecular changes in ESCC will enable identification of molecular subtypes and provide potential targets for early detection and therapy.

EXPERIMENTAL DESIGN

We followed up a previous array study with additional discovery and confirmatory studies in new ESCC cases by using alternative methods. We profiled global gene expression for discovery and confirmation, and validated selected dysregulated genes with additional RNA and protein studies.

RESULTS

A total of 159 genes showed differences with extreme statistical significance (P < E-15) and 2-fold differences or more in magnitude (tumor/normal RNA expression ratio, N = 53 cases), including 116 upregulated and 43 downregulated genes. Of 41 genes dysregulated in our prior array study, all but one showed the same fold change directional pattern in new array studies, including 29 with 2-fold changes or more. Alternative RNA expression methods validated array results: more than two thirds of 51 new cases examined by real-time PCR (RT-PCR) showed 2-fold differences or more for all seven genes assessed. Immunohistochemical protein expression results in 275 cases which were concordant with RNA for five of six genes.

CONCLUSION

We identified an expanded panel of genes dysregulated in ESCC and confirmed previously identified differentially expressed genes. Microarray-based gene expression results were confirmed by RT-PCR and protein expression studies. These dysregulated genes will facilitate molecular categorization of tumor subtypes and identification of their risk factors, and serve as potential targets for early detection, outcome prediction, and therapy.

Fascin and CK4 as biomarkers for esophageal squamous cell carcinoma

BACKGROUND

Several studies have suggested that fascin, cytokeratin 14 and cytokeratin 4 may have significant roles as biomarkers for the progression and survival of esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

This study performed immunohistochemistry in tissue microarrays, profiling premalignant lesions and invasive tumors.

RESULTS

Fascin increased across the following states as follows: normal-appearing epithelium (26%) to dysplasia (46%) to ESCC (68%), while CK4 was undetectable in ESCC (0%) compared to normal-appearing epithelium (45%) or dysplasia (41%). CK14 was elevated and invariant in expression. In regression analyses, compared to normal-appearing epithelium, higher fascin expression was associated with a 36% increased risk of dysplasia (odds ratio=1.36) and a 56% increased risk of invasive ESCC (odds ratio=1.56).

CONCLUSION

Expression of fascin is up-regulated in the transformation from normal-appearing epithelium, through dysplasia, into invasive carcinoma. Expression of CK4, CK14 and fascin did not correlate with patient survival. Fascin has a potential role as an early detection biomarker and CK4 as a tumor marker in ESCC.

Podoplanin expression in cancerous stroma induces lymphangiogenesis and predicts lymphatic spread and patient survival

CONTEXT

Podoplanin is a mucin-type glycoprotein and a lymphatic endothelial marker. Immunohistochemical staining for podoplanin is currently used as a routine pathologic diagnosis tool in Japan to identify lymphatic invasion of cancer cells. Recent reports suggest that podoplanin and other proangiogenic molecules are expressed in stromal fibroblasts and myofibroblasts.

OBJECTIVE

To analyze the distribution of podoplanin expression in tumor stroma and its clinical and biologic significance.

DESIGN

We performed immunohistochemistry for podoplanin on tissue microarrays from 1350 cases of 14 common cancer types.

RESULTS

Two hundred eighty-seven of 662 cases (43%) showed podoplanin expression in the stromal cells within cancer nests. Stromal podoplanin expression in 14 common cancer types was significantly associated with tumor stage (P < .001), lymph node metastases (P < .001), lymphatic invasion (P  =  .02), and venous invasion (P < .001). The stromal cells positive for podoplanin were also positive for α-smooth muscle actin but negative for desmin, confirming a myofibroblasts phenotype. In contrast, myofibroblasts in inflammatory fibrotic lung diseases were podoplanin negative. Lymphatic vessel density was greater in the stromas with podoplanin expression than in the stroma lacking podoplanin-expressing stromal cells (P  =  .01). Survival data were available for non-small cell lung cancer. Stromal podoplanin expression was associated with poorer prognosis in adenocarcinoma (P < .001) and remains statistically significant after adjustment for sex, age, and stage (P  =  .01).

CONCLUSION

Our data indicate that podoplanin expression in stromal myofibroblasts may function as a proangiogenic biomarker and may serve as a predictive marker of lymphatic/vascular spread of cancer cells and a prognostic marker of patient survival.

Podoplanin expression in cancerous stroma induces lymphangiogenesis and predicts lymphatic spread and patient survival

CONTEXT

Podoplanin is a mucin-type glycoprotein and a lymphatic endothelial marker. Immunohistochemical staining for podoplanin is currently used as a routine pathologic diagnosis tool in Japan to identify lymphatic invasion of cancer cells. Recent reports suggest that podoplanin and other proangiogenic molecules are expressed in stromal fibroblasts and myofibroblasts.

OBJECTIVE

To analyze the distribution of podoplanin expression in tumor stroma and its clinical and biologic significance.

DESIGN

We performed immunohistochemistry for podoplanin on tissue microarrays from 1350 cases of 14 common cancer types.

RESULTS

Two hundred eighty-seven of 662 cases (43%) showed podoplanin expression in the stromal cells within cancer nests. Stromal podoplanin expression in 14 common cancer types was significantly associated with tumor stage (P < .001), lymph node metastases (P < .001), lymphatic invasion (P  =  .02), and venous invasion (P < .001). The stromal cells positive for podoplanin were also positive for α-smooth muscle actin but negative for desmin, confirming a myofibroblasts phenotype. In contrast, myofibroblasts in inflammatory fibrotic lung diseases were podoplanin negative. Lymphatic vessel density was greater in the stromas with podoplanin expression than in the stroma lacking podoplanin-expressing stromal cells (P  =  .01). Survival data were available for non-small cell lung cancer. Stromal podoplanin expression was associated with poorer prognosis in adenocarcinoma (P < .001) and remains statistically significant after adjustment for sex, age, and stage (P  =  .01).

CONCLUSION

Our data indicate that podoplanin expression in stromal myofibroblasts may function as a proangiogenic biomarker and may serve as a predictive marker of lymphatic/vascular spread of cancer cells and a prognostic marker of patient survival.

Promises and challenges of predictive tissue biomarkers

Personalized medicine relies upon individualized diagnosis that provides molecular information delineating optimal therapeutic strategies. For many diseases, but especially cancer, the development of predictive biomarkers requires performing assays directly on the diseased tissue or tumor. The last decade has seen the explosion of both prognostic and predictive biomarkers in the research setting, but few of these biomarkers have entered widespread clinical use. This article examines issues concerning tissue-biomarker development and the hurdles faced in reaching the goal of truly personalized medicine. Targeted therapy guided by predictive biomarkers is possible; however, for significant progress, researchers need to focus on three key issues: robust assays for the clinic, validation in clinically relevant environments and assuring appropriate analytes are available for these new assays.

Biomarkers of apoptosis and survival in esophageal squamous cell carcinoma

Background

Cancer of the esophagus is a deadly malignancy, and development of biomarkers that predict survival is an urgent need. The apoptotic pathways have been hypothesized as important in progression of esophageal squamous cell carcinoma (ESCC). We investigated a panel of proteins that regulate apoptosis as candidate of biomarkers of prognosis in ESCC.

Methods

Tissue microarray (TMA) including 313 surgically-resected cases of ESCC specimens was built for immunohistochemical interrogation. We evaluated seven genes in the FasL-Fas apoptotic pathway - FasL, Fas, FAS-associated death domain protein (FADD), phosphorylated-FADD, and caspase 8 and 10, and the antiapoptotic protein bcl-2. We studied pathway integrity and relations to risk and clinical factors, and determined the prognostic significance of each marker.

Results

Five markers showed strong inter-marker correlations (r ≥ 0.28, p < 0.001), including FasL, Fas, FADD, and caspases 8 and 10. FasL and FADD also showed modest correlations with one or more cancer risk factors, but none of the markers was significantly associated with either tumor stage or lymph node metastasis, the only two clinical factors that predicted survival in these ESCC cases. Multivariate-adjusted proportional hazard regression models showed no association between protein expression and risk of death for any of the seven markers examined.

Conclusion

Individual biomarkers in the apoptosis pathway do not appear to predict survival of patients with ESCC.

Associations between selected biomarkers and prognosis in a population-based pancreatic cancer tissue microarray

Pancreatic cancer is the fourth leading cause of cancer death in the United States. Prognostic biomarkers are lacking, and treatment has limited effect on survival. Tissues from Surveillance, Epidemiology, and End Results registries (Iowa, Hawaii, and Los Angeles) were used to build a tissue microarray of 161 pancreatic tumors (113 resections and 48 biopsies). Proportional hazard models adjusted for age, race, sex, stage, time-period of diagnosis, and treatment. Associations were examined between markers (MUC1, MUC2, MUC5AC, synaptophysin, chromogranin, neuron specific enolase, epidermal growth factor receptor, HER2, CD5, CD138, CK5/6, CK19, CK20, and p53) and survival time from diagnosis. After adjusting for covariates, borderline statistically significant associations were seen between expression of each of the three mucins (MUC1, MUC2, and MUC5AC) and shorter survival time. The associations strengthened for 154 (96%) adenocarcinomas, particularly the 120 (75%) well-differentiated to moderately differentiated ductal adenocarcinomas, a tumor type that occurred more often in the cohort among White cases than cases of other racial origin (P<0.01). For differentiated ductal adenocarcinomas, associations with shorter survival time were seen for expression of all three mucins combined versus other mucin expression patterns (adjusted hazard ratio, 1.8; 95% confidence interval, 1.2-2.6) and for MUC2(+) versus MUC2(-) expression (adjusted hazard ratio, 1.6; 95% confidence interval, 1.1-2.4). Mucin gene expression, particularly MUC2 expression, may have prognostic value for differentiated adenocarcinomas. Tumor histologies differed in this and Japanese cohorts. The tissue microarray is available to evaluate other biomarkers. Tissue-based surveillance can be used to monitor tumor histology in populations and facilitate applied research.

Overexpression of CDC25B and LAMC2 mRNA and protein in esophageal squamous cell carcinomas and premalignant lesions in subjects from a high-risk population in China

Molecular events associated with the initiation and progression of esophageal squamous cell carcinoma (ESCC) remain poorly understood but likely hold the key to effective early detection approaches for this almost invariably fatal cancer. CDC25B and LAMC2 are two promising early detection candidates emerging from new molecular studies of ESCC. To further elucidate the role of these two genes in esophageal carcinogenesis, we did a series of studies to (a) confirm RNA overexpression, (b) establish the prevalence of protein overexpression, (c) relate protein overexpression to survival, and (d) explore their potential as early detection biomarkers. Results of these studies indicated that CDC25B mRNA was overexpressed (>/=2-fold overexpression in tumor compared with normal) in 64% of the 73 ESCC cases evaluated, whereas LAMC2 mRNA was overexpressed in 89% of cases. CDC25B protein expression was categorized as positive in 59% (144 of 243) of ESCC cases on a tumor tissue microarray, and nonnegative LAMC2 patterns of protein expression were observed in 82% (225 of 275) of cases. Multivariate-adjusted proportional hazard regression models showed no association between CDC25B protein expression score and risk of death [hazard ratio (HR) for each unit increase in expression score, 1.00; P = 0.90]; however, several of the LAMC2 protein expression patterns strongly predicted survival. Using the cytoplasmic pattern as the reference (the pattern with the lowest mortality), cases with a diffuse pattern had a 254% increased risk of death (HR, 3.52; P = 0.007), cases with no LAMC2 expression had a 169% increased risk of death (HR, 2.69; P = 0.009), and cases with a peripheral pattern had a 130% greater risk of death (HR, 2.30; P = 0.02). CDC25B protein expression scores in subjects with esophageal biopsies diagnosed as normal (n = 35), dysplastic (n = 23), or ESCC (n = 32) increased significantly with morphologic progression. For LAMC2, all normal and dysplastic patients had a continuous pattern of protein expression, whereas all ESCCs showed alternative, noncontinuous patterns. This series of studies showed that both CDC25B and LAMC2 overexpress RNA and protein in a significant majority of ESCC cases. The strong relation of LAMC2 pattern of protein expression to survival suggests a role in prognosis, whereas the association of CDC25B with morphologic progression indicates a potential role as an early detection marker.

Tissue microarrays enabling high-throughput molecular pathology

The tissue microarray has enabled high-throughput pathology. Rather than the laborious review of individual slides and issues of assay reproducibility across large series of specimens, tissue microarrays allow the review of a single stain on a single slide containing tens to hundreds of samples. This is a paradigm shift in pathology, away from histomorphology and toward molecular characterization by immunohistochemistry. This platform allows large retrospective clinical studies of biomarkers for correlation with outcome and can equally well be applied toward high-throughput analysis of cell lines and xenografts. Tissue microarrays encourage novel approaches to assaying tissue with retained histomorphology and have enabled image analysis in pathology. The reduction of tissue to an analyte for high-throughput analysis has highlighted the importance of a high quality tissue and the impact of tissue handling and processing in the quality of data that can be obtained from analysis of tissue.

Credentialing preclinical pediatric xenograft models using gene expression and tissue microarray analysis

Human tumor xenografts have been used extensively for rapid screening of the efficacy of anticancer drugs for the past 35 years. The selection of appropriate xenograft models for drug testing has been largely empirical and has not incorporated a similarity to the tumor type of origin at the molecular level. This study is the first comprehensive analysis of the transcriptome of a large set of pediatric xenografts, which are currently used for preclinical drug testing. Suitable models representing the tumor type of origin were identified. It was found that the characteristic expression patterns of the primary tumors were maintained in the corresponding xenografts for the majority of samples. Because a prerequisite for developing rationally designed drugs is that the target is expressed at the protein level, we developed tissue arrays from these xenografts and corroborated that high mRNA levels yielded high protein levels for two tested genes. The web database and availability of tissue arrays will allow for the rapid confirmation of the expression of potential targets at both the mRNA and the protein level for molecularly targeted agents. The database will facilitate the identification of tumor markers predictive of response to tested agents as well as the discovery of new molecular targets.

Neuronal apoptosis mediated by IL-1 beta expression in viral encephalitis caused by a neuroadapted strain of the mumps virus (Kilham Strain) in hamsters

The neuroadapted Kilham strain of the mumps virus produces lethal encephalitis in newborn hamsters after intracerebral inoculation. The pathogenesis of this encephalitis is not fully understood, but recently, apoptosis and associated cytokine production have been recognized to be major pathologic mechanisms by which viruses cause injury to neuronal host cells. To analyze the main factors producing brain injury in this viral encephalitis, the following questions were investigated: (1) does the virus induce neuronal apoptosis and (2) does expression of cytokines regulate the induction of neuronal apoptosis? Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) was used as a marker of neuronal apoptosis and TUNEL-positive neurons were widespread in the infected cerebral cortex. DNA fragmentation yielding DNA ladders characteristic of apoptosis was also observed in infected hamster brain tissue. Apoptotic cells in infected brains were observed after the appearance of inflammatory changes. Overexpression of IL-1 beta, but not TNF-alpha or Fas-L, was clearly detected in infected brains, as determined by Western blot and RT-PCR. Immunohistochemistry revealed a striking correlation between IL-1 beta expression and neuronal apoptosis. Injection of recombinant IL-1 beta into normal hamster brain resulted in neuronal apoptosis in cerebral cortex. On the other hand, neutralizing IL-1 beta antibodies decreased the number of cells undergoing apoptosis in infected hamster brains and subsequent death. We conclude that the fatal encephalitis induced by the Kilham strain of the mumps virus is mediated by immunopathological processes and that overexpression of IL-1 beta, which mediates the induction of neuronal apoptosis, may play a major role in these processes.