High-density Tissue Microarrays Research Articles

Constructing high-density tissue microarrays with a novel method and a self-made tissue-arraying instrument.

Tissue microarrays (TMAs), also called tissue chips, contain hundreds to thousands of tissue cores obtained from different tissue donor blocks. By using TMA technology, a molecular marker, such as protein, RNA or DNA, can be simultaneously examined in hundreds of different specimens under the same experimental conditions. A growing number of previous studies have introduced different methods for constructing TMAs. Many authors tried to use various methods to implant more tissue cores in a single recipient block, and most of these methods involved reducing the diameter of the tissue cores and/or the spacing between adjacent tissue cores. However, when creating TMAs, it is difficult to reduce the distance between tissue cores to zero except with extremely expensive automatic TMA arrayers. Here, we introduce a novel method to construct a high-density TMA that does not have spacing between the tissue cores. We also introduce a method for preparing a self-made tissue-arraying instrument. With this method and the tissue-arraying instrument, we successfully created a TMA containing 126 tissue cores that were 2mm in diameter. H&E staining and immunohistochemical staining were performed on the sections cut from the TMA without any tissue spot loss. This method is easy to operate, and the materials for creating the tissue-arraying instrument are inexpensive and can be purchased anywhere. Therefore, this method can be applied in all laboratories.

TMA-Mate: An open-source modular toolkit for constructing tissue microarrays of arbitrary layouts

Biomedical research and quality control procedures often demand a variety of microscopic analysis of numerous formalin-fixed and paraffin-embedded (FFPE) tissue samples from different individuals of both healthy and diseased regions of interest. Depending on the number of samples to be analyzed, conventional processing of each FFPE block separately can be laborious or impracticable. This effort can be drastically reduced by using tissue microarrays (TMAs). TMAs have a wide range of applications and can be considered as a high-throughput method to process up to hundreds of miniaturized tissue samples simultaneously on a single microscopy slide, in order to reduce labor, costs and sample consumption, and to increase results comparability. Several commercial and self-made solutions to fabricate TMAs with varying degrees of automation are available. However, these solutions may not be suitable for every situation, either due to high costs, high complexity, lack of precision or lack of flexibility, especially when diagnostically oriented pathology institutes or laboratories with constrained resources are considered. This article introduces the TMA-Mate, an open-source 3D printable modular toolkit for constructing high-density TMAs of arbitrary layouts, providing an affordable, lightweight, and accessible procedure to implement TMAs into existing histology processing pipelines. Step-by-step demonstrations for replicating the hardware and constructing TMAs are included.

IL-33 Participates in the Development of Esophageal Adenocarcinoma.

Background: The progression from chronic gastroesophageal reflux disease (GERD) to Barrett esophagus (BE) and esophageal adenocarcinoma (EAC) is an inflammatory-driven neoplastic change. Interleukin-33 (IL-33) has identified as a crucial factor in several inflammatory disorders and malignancies. Methods: The high-density tissue microarray of the human EAC was analyzed with IL-33 immunohistochemistry staining (IHC). By anastomosing the jejunum with the esophagus, the rat model of EAC with mixed gastroduodenal reflux was established. The expression of IL-33 was determined using quantitative real-time polymerase chain reaction (RT-qPCR), western blot (WB), IHC and enzyme-linked immunosorbent assay (ELISA). Esophageal adenocarcinoma cells (OE19 and OE33) and human esophageal epithelial cells (HEECs) were used. Results: In the cytoplasm of human EAC tissue, IL-33 expression was substantially greater than in adjacent normal tissue. In rat model, the expression of IL-33 in the EAC group was considerably greater than in the control group, and this expression increased with the upgrade of pathological stage. In in vitro experiment, the mRNA and protein levels of IL-33 were considerably greater in OE19 and OE33 than in HEECs. The stimulation of IL-33 enhanced the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of OE19 and OE33, but soluble ST2 (sST2) inhibited these effects. IL-33 stimulated the release of IL-6 by OE19 and OE33 cells. Conclusion: This study demonstrated the overexpression of IL-33 in the transition from GERD to EAC and that IL-33 promoted carcinogenesis in EAC cells through ST2. IL-33 might be a possible preventive target for EAC.

Simple method for constructing and repairing tissue microarrays using simple equipment.

ObjectiveMany methods for tissue microarray (TMA) construction were described in previous reports. Because TMA-based methods are expensive and complicated, their widespread application may be restricted. This study aimed to develop a simple method for TMA construction.MethodsHigh-density TMAs were constructed using simple equipment, and hematoxylin and eosin and immunohistochemical staining were performed to analyze the effect on the TMA block.ResultsA recipient block with 162 holes of 0.9 mm in diameter was prepared using a mini-drill and plastic mold. Tissue cores of 1.0 mm in diameter were obtained from multiple donor blocks with stainless-steel capillary tubes driven by the mini-drill. Under the fixation and guidance of the plastic mold, tissue cores could be easily injected into the holes in the recipient block by inserting a stainless-steel wire into the stainless-steel tube with the tissue core and then pressing using the stainless-steel wire.ConclusionA high-density TMA block with 162 1.0-mm cores was created. This new modified technique could be a good alternative in many laboratories.

Pathological and Prognostic Indications of the mdig Gene in Human Lung Cancer

Background/Aims:The mineral-dust-induced gene mdig is a lung-cancer-associated oncogene. The focus of this study is to evaluate the expression status of mdig in lung cancer and to assess its influence in predicting the patient’s overall survival.Methods:Using high-density tissue microarrays and clinical samples of synchronous multiple primary lung cancer (SMPLC), we investigated the expression of mdig through immunohistochemistry and utilized the open-access lung cancer patient databases containing genomic and transcriptomic data from the UCSC Xena and TCGA web platforms to determine the prognostic values of mdig expression status among different subtypes of lung cancer.Results:mdig is upregulated in smokers and in lung squamous cell carcinoma. High mdig expression predicted poor overall survival in lung squamous cell carcinoma and female smokers. Among tumor tissues from SMPLC patients, we not only unraveled the highest positive rate of mdig expression, but also revealed a unique cytoplasmic, rather than nuclear localization of mdig protein. Furthermore, by inspecting some pathological but not cancerous lung tissues, we believe that mdig is required for the transformation of non-cancerous lung cells to the fully-fledged cancer cells.Conclusion:These data suggested that mdig is involved in various stages of lung carcinogenesis, possibly through the epigenetic regulation on some critical cancer-associated genes, and increased mdig expression is an important prognostic factor for some types of lung cancer.

SOX10 is as specific as S100 protein in detecting metastases of melanoma in lymph nodes and is recommended for sentinel lymph node assessment

BackgroundSentinel lymph node (SLN) biopsy remains crucial for melanoma staging. The European Organisation for Research and Treatment of Cancer Melanoma Group recommends performing immunohistochemical stainings for reproducible identification of melanoma metastases. S100 protein (pS100) is a commonly used melanocytic antigen because of its high sensitivity in spite of relatively low specificity. SRY-related HMG-box 10 protein (SOX10) is a transcription factor characterising neural crest-derived cells. It is uniformly expressed mostly in the nuclei of melanocytes, neural, and myoepithelial cells. Pathologists sometimes prefer SOX10 as a melanoma marker, but it has not yet been investigated on a large-scale to confirm that it is reliable and recommendable for routine SLN evaluation. MethodsFour hundred one treatment-naïve lymph node (LN) metastatic melanomas were included in high-density tissue microarrays and were assessed for the presence of SOX10 and pS100 by immunohistochemistry. The slides were digitalised, shared and evaluated by a panel of experienced melanoma pathologists. ResultsThe vast majority of melanomas were double-positive for pS100 and SOX10 (93.2%); a small percentage of the cases (3.9%) were double-negative melanomas. Discordance between the two markers was observed: 1.9% pS100(−)/SOX10(+) and 0.75% pS100(+)/SOX10(−). SOX10 was not expressed by immune cell types in the LN, resulting in a less controversial interpretation of the staining. ConclusionsSOX10 is as equally specific as pS100 for the detection of melanoma metastases in LNs. The interpretation of SOX10 staining is highly reproducible among different centres and different pathologists because of the absence of staining of immune cells.

Alternative promoters control UGT2B17-dependent androgen catabolism in prostate cancer and its influence on progression

BackgroundPerturbation of the major UGT2B17-dependent androgen catabolism pathway has the potential to affect prostate cancer (PCa) progression. The objective was to evaluate UGT2B17 protein expression in primary tumours in relation to hormone levels, disease characteristics and cancer evolution.MethodsWe conducted an analysis of a high-density prostate tumour tissue microarray consisting of 239 localised PCa cases treated by radical prostatectomy (RP). Cox proportional hazard ratio analysis was used to evaluate biochemical recurrence (BCR), and a linear regression model evaluated variations in circulating hormone levels measured by mass spectrometry. The transcriptome of UGT2B17 in PCa was established by using RNA-sequencing data.ResultsUGT2B17 expression in primary tumours was associated with node-positive disease at RP and linked to circulating levels of 3α-diol-17 glucuronide, a major circulating DHT metabolite produced by the UGT2B17 pathway. UGT2B17 was an independent prognostic factor linked to BCR after RP, and its overexpression was associated with development of metastasis. Finally, we demonstrated that distinctive alternative promoters dictate UGT2B17-dependent androgen catabolism in localised and metastatic PCa.ConclusionsThe androgen-inactivating gene UGT2B17 is controlled by overlooked regulatory regions in PCa. UGT2B17 expression in primary tumours influences the steroidome, and is associated with relevant clinical outcomes, such as BCR and metastasis.

FGFR1 Expression and Role in Migration in Low and High Grade Pediatric Gliomas.

The heterogeneous and invasive nature of pediatric gliomas poses significant treatment challenges, highlighting the importance of identifying novel chemotherapeutic targets. Recently, recurrent Fibroblast growth factor receptor 1 (FGFR1) mutations in pediatric gliomas have been reported. Here, we explored the clinical relevance of FGFR1 expression, cell migration in low and high grade pediatric gliomas and the role of FGFR1 in cell migration/invasion as a potential chemotherapeutic target. A high density tissue microarray (TMA) was used to investigate associations between FGFR1 and activated phosphorylated FGFR1 (pFGFR1) expression and various clinicopathologic parameters. Expression of FGFR1 and pFGFR1 were measured by immunofluorescence and by immunohistochemistry (IHC) in 3D spheroids in five rare patient-derived pediatric low-grade glioma (pLGG) and two established high-grade glioma (pHGG) cell lines. Two-dimensional (2D) and three-dimensional (3D) migration assays were performed for migration and inhibitor studies with three FGFR1 inhibitors. High FGFR1 expression was associated with age, malignancy, tumor location and tumor grade among astrocytomas. Membranous pFGFR1 was associated with malignancy and tumor grade. All glioma cell lines exhibited varying levels of FGFR1 and pFGFR1 expression and migratory phenotypes. There were significant anti-migratory effects on the pHGG cell lines with inhibitor treatment and anti-migratory or pro-migratory responses to FGFR1 inhibition in the pLGGs. Our findings support further research to target FGFR1 signaling in pediatric gliomas.

Synuclein-γ in uterine serous carcinoma impacts survival: An NRG Oncology/Gynecologic Oncology Group study.

Synuclein-γ (SNCG) is highly expressed in advanced solid tumors, including uterine serous carcinoma (USC). The objective of the current study was to determine whether SNCG protein was associated with survival and clinical covariates using the largest existing collection of USCs from the Gynecologic Oncology Group (GOG-8023). High-density tissue microarrays (TMAs) of tumor tissues from 313 patients with USC were stained by immunohistochemistry for SNCG, p53, p16, FOLR1, pERK, pAKT, ER, PR, and HER2/neu. Associations of SNCG and other tumor markers with overall and progression-free survival were assessed using log-rank tests and Cox proportional-hazards models, which also were adjusted for age, race, and stage. The overall survival at 5 years was 46% for women with high SNCG expression and 62% for those with low SNCG expression (log-rank P = .021; hazard ratio [HR], 1.31; 95% confidence interval [CI], 0.91-1.9 in adjusted Cox model). The progression-free survival rate at 5 years was worse for women who had high SNCG expression, at 40%, compared with 56% for those who had low SNCG expression (log-rank P = .0081; HR, 1.36; 95% CI, 0.96-1.92 in adjusted Cox model). High levels of both p53 and p16 were significantly associated with worse overall survival (p53: HR, 4.20 [95% CI, 1.54-11.45]; p16: HR, 1.95 [95% CI, 1.01-3.75]) and progression-free survival (p53: HR, 2.16 [95% CI, 1.09-4.27]; p16: HR, 1.53 [95% CI, 0.87-2.69]) compared with low levels. This largest collection of USCs to date demonstrates that SNCG was associated with poor survival in univariate analyses. SNCG does not predict survival outcome independent of p53 and p16 in models that jointly consider multiple markers. Cancer 2017;123:1144-1155. © 2016 American Cancer Society.

Immune-checkpoint status in penile squamous cell carcinoma: a North American cohort

Penile squamous cell carcinoma (SCC) is primarily treated by surgical resection. Locally advanced and metastatic diseases require a multidisciplinary treatment approach. However, mortality and morbidity remain high, and novel molecular and immunotherapeutic targets are actively being sought. We investigated the expression of immune-checkpoint markers in penile cancers. Fifty-three invasive penile SCCs diagnosed between 1985 and 2013 were retrieved from our surgical pathology archives. Representative formalin-fixed, paraffin-embedded archival blocks were used for the construction of 2 high-density tissue microarrays. Tissue microarrays were stained with immunohistochemistry for PD-L1, FOXP3, CD8, and Ki-67. PD-L1 was investigated using rabbit monoclonal anti-PD-L1 antibody (Cell Signaling, Boston, MA; E1L3N, 1:100). Overall, 21 (40%) of 53 penile SCCs had positive PD-L1 expression. PD-L1 was expressed by a significant proportion of advanced penile SCC. Forty-four percent (15/34) of stage pT2 or more SCC and 38% (6/16) of tumors with lymph node metastasis were positive for PD-L1. PD-L1 expression did not correlate with patient age, tumor location, histologic subtype, tumor stage, anatomic depth of invasion, or tumor grade. FOXP3 expression in tumoral immune cells was found in 26 (49%) of 53 cases. FOXP3 expression in stromal immune cells correlated with tumor thickness (P = .0086). The ratio of CD8/FOXP3 was greater than 1 in 62% of cases in tumor-infiltrating immune cells and 34% of cases in stromal immune cells. Our current study is the largest to assess expression of PD-L1 in a clinically well-annotated North American cohort of penile SCC. Our findings support a rationale for targeting immune-checkpoint inhibitor pathways in advanced penile SCC.

Association of TIP30 expression and prognosis of hepatocellular carcinoma in patients with HBV infection.

Altered expression of TIP30, a tumor suppressor, has been observed in many cancers. In this study, we have evaluated the expression of TIP30 in the tissues of 209 hepatocellular carcinomas (HCC) and their adjacent tissues by using a high‐density tissue microarray, and analyzed its correlation with the clinical pathological parameters of the patients. The results revealed negative or weak expression of TIP30 in 43.5% (91/209) of the HCC tissues, and in only 27% (56/209) of the adjacent tissues. The expression level of TIP30 in HCC was inversely correlated with serum alpha‐fetoprotein (AFP) levels, HBV infection, and tumor differentiation. Multivariate analysis for survival indicated that serum HBV infection was the most significant predictor of poor prognosis in HCC (P = 0.0023), and TIP30 expression and tumor differentiation were also independent indicators in this respect (P = 0.0364 and P = 0.0397, respectively). Patients with medium or high expression levels of TIP30 (TIP30++/+++) had a better 5‐year overall survival rate than those with low/negative (TIP30+/−) expression (P < 0.001). TIP30+/−/HBV+ patients had the worst 5‐year overall survival rate, whereas TIP30++/+++/HBV− patients had the best. To further explore the correlation between TIP30 and HBV infection in HCC, HBV+ hepatoblastoma cell‐line HepG2 2.2.15 and HCC cell‐line Hep3B were used. Upon silencing of HBV, we observed an upregulation of TIP30 and decreased cell proliferation. In the in vivo studies, we found that the mice inoculated with HepG2 2.2.15 cells with HBV silencing had a prolonged tumor latency and a longer life span, as compared to the control mice inoculated with untreated control cells. In conclusion, the results suggest that downregulation of TIP30 may result from HBV infection, and subsequently promotes the progression of HCC.

Abstract 4384A: A novel potential therapeutic target for breast, lung, ovary and colon cancer

Abstract We identified 89 novel candidate markers for prevalent cancers by a systematic Tissue microarray analysis (TMA) of a large collection of polyclonal antibodies (approximately 1600) raised against membrane-associated and secreted human proteins currently marginally characterized. Among them, here we report a novel cancer-associated protein, referred as EXN32, so far only marginally characterized. EXN32 is a metallo-protease highly conserved across species, known to be involved in ovarian folliculogenesis. An anti-EXN32 monoclonal antibody (mAb) detects the protein in a high percentage of in breast, lung, ovary, and colo-rectal (CRC) cancers (high-to-medium intensity ranging from 30 to 70% in different cancer types. An analysis of high density tissue microarrays (300-700 highly characterized clinical specimens per each cancer) shows that EXN32 is over-expressed in all cancer stages and grades. In breast cancer, a EXN32 it is over-expressed in Her-2+, PR+ and ER+ patients and also in triple negative cases. In colon cancer, EXN32 is over-expressed both in B-RAF and K-RAS mutant and wild type cancers. We also found that EXN32 over-expression is statistically associated to a low activation of cadherin and beta-catenin pathways. Moreover, its expression is also associated with other prognostic and predictive markers. This evidence opens the way to further investigations on the EXN32 role in the marker-associated pathways. A characterization of the protein biological role showed that alteration of EXN32 expression strongly hampers cell proliferation, migration and invasiveness. The molecular pathways in which the protein is involved show that it plays a role in the Unfolded Protein Response and defence against oxidative stress. Our findings reveal that EXN32 is strongly affected by reticular stress induced by thapsigargin. In addition, EXN32 silencing during reticular stress protect cells from expressing the stress marker Bip/Grp78. In addition, EXN32 is involved also in handling of oxidative stress. Indeed, EXN32 silencing in cells exposed to 1% O2 hypoxia, causing a mitochondrial delivery of oxidants and hence sustaining oxidative stress, leads to inhibition of the Nrf2-mediated anti-oxidant response and to reduction of accumulation of HIF-1, the master transcription factor instructing cells to respond to hypoxic stress. We are investigating the possibility that EXN32 may participate as a molecular starter to the survival response induced by extracellular stresses. Results indicate EXN32 as a potential target for the design of novel drugs, such as aptamers, small molecules and protease inhibitors. For instance, molecules such as 2-PMPA and analogues are expected to inhibit EXN32 activity. Moreover, EXN32 and its specific mAb represent interesting tools for the molecular characterization of specific cancer subtypes. Investigations are ongoing to understand the prognostic and predictive value of EXN32. Citation Format: Matteo Parri, Alberto Grandi, Susanna Campagnoli, Elisa De Camilli, Alice Santi, Boquan Jin, Paolo Sarmientos, Guido Grandi, Giuseppe Viale, Paola Chiarugi, Luigi Terracciano, Piero Pileri, Renata Maria Grifantini. A novel potential therapeutic target for breast, lung, ovary and colon cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4384A. doi:10.1158/1538-7445.AM2015-4384A

CXCL16/CXCR6 chemokine signaling mediates breast cancer progression by pERK1/2-dependent mechanisms.

Our previous studies demonstrate that CXCL6/CXCR6 chemokine axis induces prostate cancer progression by the AKT/mTOR signaling pathway; however, its role and mechanisms underlying invasiveness and metastasis of breast cancer are yet to be elucidated. In this investigation, CXCR6 protein expression was examined using high-density tissue microarrays and immunohistochemistry. Expression of CXCR6 shows a higher epithelial staining in breast cancer nest site and metastatic lymph node than the normal breast tissue, suggesting that CXCR6 may be involved in breast cancer (BC) development. In vitro and in vivo experiments indicate that overexpression of CXCR6 in BC cells has a marked effect on increasing cell migration, invasion and metastasis. In contrast, reduction of CXCR6 expression by shRNAs in these cells greatly reduce its invasion and metastasis ability. Mechanistic analyses show that CXCL16/CXCR6 chemokine axis is capable of modulating activation of RhoA through activating ERK1/2 signaling pathway, which then inhibits the activity of cofilin, thereby enhancing the stability of F-actin, responsible for invasiveness and metastasis of BC. Taken together, our data shows for the first time that the CXCR6 / ERK1/2/ RhoA / cofilin /F-actin pathway plays a central role in the development of BC. Targeting the signaling pathway may prove beneficial to prevent metastasis and provide a more effective therapeutic strategy for BC.

Relation of glypican-3 and E-cadherin expressions to clinicopathological features and prognosis of mucinous and non-mucinous colorectal adenocarcinoma.

Glypican-3 (GPC3) is a member of the membrane-bound heparin sulfate proteoglycans. E-cadherin is an adhesive receptor that is believed to act as a tumor suppressor gene. Many studies had investigated E-cadherin expressions in colorectal carcinoma (CRC) while only one study had investigated GPC3 expression in CRC. This study aims to investigate expression of GCP3 and E-cadherin in colorectal mucinous carcinoma (MA) and non-mucinous adenocarcinoma (NMA) using manual tissue microarray technique. Tumor tissue specimens are collected from 75 cases of MC and 75 cases of NMA who underwent radical surgery from Jan 2007 to Jan 2012 at the Gastroenterology Centre, Mansoura University, Egypt. Their clinicopathological parameters and survival data were revised and analyzed using established statistical methodologies. High-density manual tissue microarrays were constructed using modified mechanical pencil tip technique and immunohistochemistry for GPC3 and E-cadherin was done. NMA showed higher expression of GPC3 than MA with no statistically significant relation. NMA showed a significantly higher E-cadherin expression than MA. GPC3 and E-cadherin positivity rates were significantly interrelated in NMA, but not in MA, group. In NMA group, there was no significant relation between either GPC3 or E-cadherin expression and the clinicopathological features. In a univariate analysis, neither GPC3 nor E-cadherin expression showed a significant impact on disease-free survival (DFS) or overall survival (OS). GPC3 and E-cadherin expressions are not independent prognostic factors in CRC. However, expressions of both are significantly interrelated in NMA patients, suggesting an excellent interplay between both, in contrast to MA. Further molecular studies are needed to further explore the relationship between GCP3 and E-cadherin in colorectal carcinogenesis.

Abstract C70: ABCD3 expression in prostate and breast tumors

Abstract Background: In a previous study, we identified the ABCD3 gene as important in aggressive prostate tumors. The ABCD3 gene is a member of the ABC (ATP-Binding Cassette) family. The ABC gene family give instructions for making transporter proteins that carry many types of molecules, such as fats, sugars, protein building blocks (amino acids) and drugs, across cell membranes and is known to play a role in chemoresistance is some cancers. Purpose: Little is known about role of ABCD3 in prostate cancer, hence in the present study we assessed the expression of ABCD3 in normal and malignant prostate tissue (without regard to racial ethnicity) and determined correlations between ABCD3 expression and clinicopathologic characteristics. Methods: Clinically annotated duplicate core tissue high-density prostate adenocarcinoma tissue microarray of 92 cases of adenocarcinoma, 2 prostate transitional cell carcinoma, 12 prostate adjacent normal tissue and 8 normal prostate tissue were stained with a monoclonal antibody against ABCD3 and scored for percentage of visible staining. Results: Increased ABCD3 expression correlated with increasing Gleason score (p=0.0094), age (p=0.0014) and pathology grade (p=0.0007). Interestingly, we also observed that ABCD3 expression was elevated to varying degrees in other types of cancers, breast (stage II a), brain, cervical, head and neck, kidney and pancreatic. Conclusions: We postulate that ABCD3 may be a putative prognostic biomarker that discriminates between indolent and aggressive cancers, albeit ABCD3 function in cancer progression is still under investigation. Citation Format: R. Renee Reams, Jacqueline D. Jones, Daniel Osborne, Honghe Wang, Clayton C. Yates, III. ABCD3 expression in prostate and breast tumors. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr C70. doi:10.1158/1538-7755.DISP13-C70

CXCR7 stimulates MAPK signaling to regulate hepatocellular carcinoma progression.

The CXCL12/CXCR4 axis has been posited widely to have significant roles in many primary tumors and metastases. It is known that CXCR7 can also be engaged by CXCL12, but the exact function of CXCR7 is controversial. This prompted us to investigate the expression, specific function and signal transduction of CXCR7 in hepatocellular carcinoma (HCC). In this study, CXCR7 and CXCR4 were differentially expressed in nine cell lines of HCC, and that elevated expression of both CXCR7 and CXCL4 were correlated with highly metastatic ability of HCC cells. Moreover, CXCR7 expression was significantly upregulated in metastatic HCC samples compared with the non-metastatic ones by staining of high-density tissue microarrays constructed from a cohort of 48 human HCC specimens. CXCR7 overexpression enhanced cell growth and invasiveness in vitro, and tumorigenicity and lung metastasis in vivo. By contrast, CXCR7 stable knockdown markedly reduced these malignant behaviors. In addition, it was observed that alterations in CXCR7 expression were positively correlated with the phosphorylation levels of mitogen-activated protein kinase (MAPK) pathway proteins. Targeting extracellular regulated kinase pathway by using U0126 inhibitor or using CCX771, a selective CXCR7 antagonist, drastically reduced CXCR7-mediated cell proliferation. Importantly, by using human biotin-based antibody arrays, several differentially expressed proteins were identified in CXCR7-overexpression and depletion groups. Comparative analysis indicated that upstream regulators including TP53 and IL-6 were involved in CXCR7 signal transduction. CXCR7 expression was further proved to regulate expression of vascular endothelial growth factor A and galectin-3, which may contribute to tumor angiogenesis and invasiveness. Consequently, elevated expression of CXCR7 contributes to HCC growth and invasiveness via activation of MAPK and angiogenesis signaling pathways. Targeting CXCR7 may prevent metastasis and provide a potential therapeutic strategy for HCC.

Abstract 1769: A novel potential cancer marker and therapeutic target

Abstract In our recent research activities, we identified 89 novel candidate markers for prevalent cancers by a systematic Tissue microarray analysis (TMA) of a large collection of polyclonal antibodies (pAbs, approximately 1600) raised against membrane-associated and secreted human proteins currently marginally characterized. Monoclonal antibodies were generated towards 20 distinct antigens that are being characterized and validated for diagnostic and therapeutic applications. Among them, here we describe the molecular characterization of a novel cancer -associated protein (referred as EXN32) belonging to the metallo-protease family and so far only marginally characterized. Immuno-histochemical analysis of Tissue Microarrays carrying clinical specimens from prevalent cancers and matched normal samples with the anti-EXN32 pAb showed that the protein is over-expressed in breast, lung, ovary,and colon cancers, with frequencies ranging from 30 to 70%. A characterization of the protein biological role showed that alteration of EXN32 expression significantly hampers cell proliferation, migration and invasiveness. Initial studies aimed at identifying the molecular pathways in which the protein is involved show that it plays a role in the response to the reticular stress and hypoxia. A highly specific murine monoclonal antibody (mAb) specifically recognizes the protein in the four cancer types. This mAb is currently used to discover statistical associations between EXN32 with specific clinic-pathological parameters using high density tissue microarrays carrying highly characterized clinical specimens (300-700 per each cancer). Available data on breast and colon show that EXN32 is over-expressed in all cancer stages and grades. In breast cancer, a EXN32 bio-distribution analysis versus clinically relevant surface receptors shows that the protein is over-expressed in Her-2+, PR+ and ER+ patients and also in triple negative cases. In colon cancer, EXN32 over-expression shows statistical correlation with a panel of key molecular markers such as beta-catenin, e-cadherin, TGFbeta and others, and open the way to further investigations on the EXN32 role in their associated pathways. Overall, results indicate EXN32 as a potential target for the design of novel drugs, such as aptamers, si-RNA and small molecules. The EXN32 specific mAb represents an interesting tool for the molecular characterization of specific cancer subtypes. Investigations are ongoing to understand the predictive value of EXN32 for state-of art and innovative therapeutic strategies. Citation Format: Matteo Parri, Susanna Campagnoli, Alberto Grandi, Elisa De Camilli, Valentina Farini, Serenella Eppenberger, Paola Chiarugi, Paolo Sarmientos, Boquan Jin, Guido Grandi, Giuseppe Viale, Luigi Terracciano, Piero Pileri, Renata Maria Grifantini. A novel potential cancer marker and therapeutic target. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1769. doi:10.1158/1538-7445.AM2014-1769

Elevated intrinsic cancer stem cell population in human papillomavirus‐associated head and neck squamous cell carcinoma

Human papillomavirus 16 (HPV16) is a major risk factor for the development of head and neck squamous cell carcinoma (HNSCC), particularly the development of oropharyngeal squamous cell carcinoma (OPSCC). Cancer stem cells (CSCs) are resistant to conventional therapies, and it is postulated that they are responsible for disease recurrence and/or progression. Because the prognoses of patients with HPV16-positive and HPV-negative HNSCC are distinct, the authors sought to determine whether differences in the number of CSCs could account for this clinical observation. CSC populations in HPV16-positive and HPV-negative HNSCC were assessed using a proprietary assay based on expression of the enzyme aldehyde dehydrogenase (ALDH), an in vitro tumorsphere formation assay, and an in vivo limiting cell dilution in nonobese diabetic/severe combined immunodeficiency mice. A high-density tissue microarray was stained with ALDH1, a CSC marker, to determine the association between CSCs and HPV16-positive/HPV-negative OPSCC. HPV16-positive HNSCC had a greater intrinsic CSC pool than HPV-negative HNSCC. Inactivation of p53 has been identified as a major mechanism for the elevated CSC population in HPV16-positive HNSCC. In vivo limiting cell dilution experiments using tumors from patients with HPV16-positive and HPV-negative OPSCC indicated that the CSC frequency was 62.5-fold greater in an HPV16-positive OPSCC tumor than in an HPV-negative OPSCC tumor. Primary tumors from patients with HPV16-positive OPSCC were associated with elevated tumor ALDH1 staining, further extending the association between HPV16 and CSCs. The current data and the clinical observation that patients with HPV16-positive HNSCC respond more favorably to current treatment paradigms than patients with HPV-negative HNSCC support the suggestion that CSC phenotype is not homogeneous. Therefore, the reliance on the CSC number may be insufficient to accurately assess the potential of a particular tumor for disease recurrence and/or progression.

Is GATA3 Expression Maintained in Regional Metastases?

GATA3 has been recognized as a promising marker for primary urothelial carcinoma (UC), consistently showing higher expression levels than urothelial markers thrombomodulin and uroplakin III. However, expression of GATA3 in comparison with UC-associated markers CK7 and p63 has not been systematically studied. Moreover, no studies have been conducted to establish GATA3 sensitivity in regional metastases. In this study, high-density tissue microarrays were constructed from 69 matched paired primary and metastatic bladder tumors including pure urothelial UCs with papillary (n=48) or flat phenotype (n=9), mixed tumors with micropapillary, glandular, small cell, squamous, giant cell, and plasmacytoid features (n=9), and 3 adenocarcinomas. GATA3 was expressed in 62/69 (90%) primary UC and 64/69 (93%) metastases, with significantly higher staining intensity in nodal metastases (P=0.03). In primary tumors, GATA3 was positive in 44/48 (92%) papillary UCs, 9/9 (100%) flat UCs, 8/9 (89%) mixed UCs, and 1/3 (33%) adenocarcinomas, whereas in metastases these numbers were 45/48 (94%), 9/9 (100%), 8/9 (89%), and 2/3 (67%), respectively. The majority of positive cases showed strong diffuse nuclear reactivity: 75% of primary UCs and 79% of metastases. GATA3 sensitivity in primary and metastatic UCs was comparable to that of CK7 and superior to that of p63 (P<0.05). GATA3 specificity was computed in comparison with its morphologic mimics expressing CK7 and p63, including 208 primary and 24 metastatic tumors from the lung, cervix, and head and neck regions. Strong GATA3 expression was present in 2/51 (4%) cervical carcinomas, whereas weak GATA3 expression was present in 7/51 (14%) cervical, 6/74 (8%) head and neck cancers, and 2/83 (3%) lung carcinomas. Remaining 191 primary and 24 metastatic tumors were GATA3 negative. Therefore, specificity of GATA3 calculated on the basis of morphologic and immunophenotypic UC mimics from lung, cervix, head and neck was 92%. Our findings demonstrate high sensitivity and specificity of the GATA3 diagnostic marker, with not only maintained but increased expression in regional metastases.

Expressions of CLDN1 and insulin-like growth factor 2 are associated with poor prognosis in stage N2 non-small cell lung cancer.

Patients with single station mediastinal lymph node (N2) non-small cell lung cancer (NSCLC) have a better prognosis than those with multilevel N2. The molecular factors which are involved in disease progression remain largely unknown. The purpose of this study was to investigate gene expression differences between single station and multilevel N2 NSCLC and to identify the crucial molecular factors which are associated with progress and prognosis of stage N2 NSCLC. Gene expression analysis was performed using Agilent 4×44K Whole Human Genome Oligo Microarray on 10 freshfrozen lymph node tissue samples from single station N2 and paired multilevel N2 NSCLC patients. Real-time reverse transcription (RT)-PCR was used to validate the differential expression of 14 genes selected by cDNA microarray of which four were confirmed. Immunohistochemical staining for these validated genes was performed on formalin-fixed, paraffinembedded tissue samples from 130 cases of stage N2 NSCLC arranged in a high-density tissue microarray. We identified a 14 gene expression signature by comparative analysis of gene expression. Expression of these genes strongly differed between single station and multilevel N2 NSCLC. Four genes (ADAM28, MUC4, CLDN1, and IGF2) correlated with the results of microarray and real-time RT-PCR analysis for the gene-expression data in samples from 56 NSCLC patients. Immunohistochemical staining for these genes in samples from 130 cases of stage N2 NSCLC demonstrated the expression of IGF2 and CLDN1 was negatively correlated with overall survival of stage N2 NSCLC. Our results suggest that the expression of CLDN1 and IGF2 indicate a poor prognosis in stage N2 NSCLC. Further, CLDN1 and IGF2 may provide potential targeting opportunities in future therapies.