Metastasis shares many similarities with leukocyte trafficking. Among those chemokine receptors thought to be involved in hemopoietic cell homing, stromal cell-derived factor-1 and its receptor CXC chemokine receptor-4 (CXCR4) have received considerable attention. Like hemopoietic cell homing, levels of stromal cell-derived factor-1 are high at sites of breast cancer metastasis including lymph node, lung, liver, and the marrow. Moreover, CXCR4 expression is low in normal breast tissues and high in malignant tumors, suggesting that a blockade of CXCR4 might limit tumor metastasis. We therefore investigated the role of a synthetic antagonist 14-mer peptide (TN14003) in inhibiting metastasis in an animal model. Not only was TN14003 effective in limiting metastasis of breast cancer by inhibiting migration, but it may also prove useful as a diagnostic tool to identify CXCR4 receptor-positive tumor cells in culture and tumors in paraffin-embedded clinical samples.

Tumor heterogeneity is one of the most important and challenging problems not only in studying the mechanisms of cancer development but also in developing therapeutics to eradicate cancer cells. Here we report the use of multiplexed quantum dots (QDs) and wavelength-resolved spectral imaging for molecular mapping of tumor heterogeneity on human prostate cancer tissue specimens. By using a panel of just four protein biomarkers (E-cadherin, high-molecular-weight cytokeratin, p63, and α-methylacyl CoA racemase), we show that structurally distinct prostate glands and single cancer cells can be detected and characterized within the complex microenvironments of radical prostatectomy and needle biopsy tissue specimens. The results reveal extensive tumor heterogeneity at the molecular, cellular, and architectural levels, allowing direct visualization of human prostate glands undergoing structural transitions from a double layer of basal and luminal cells to a single layer of malignant cells. For clinical diagnostic applications, multiplexed QD mapping provides correlated molecular and morphological information that is not available from traditional tissue staining and molecular profiling methods.Keywords quantum dot; tumor heterogeneity; prostate cancer; multiplexing; spectral imaging; biomarker; immunohistochemistry Semiconductor quantum dots (QDs) have unique optical and electronic properties such as size-tunable light emission, superior signal brightness, resistance to photobleaching, and * Address correspondence to snie@emory.edu.Supporting Information Available: Supporting Figures S1 and S2 showing traditional H&E staining data, comparison of single-color and multiplexed QD staining, and biomarker quantification data. This material is available free of charge via the Internet at http://pubs.acs.org. NIH Public AccessAuthor Manuscript ACS Nano. Author manuscript; available in PMC 2010 August 18. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript simultaneous excitation of multiple fluorescence colors. 1 -4 These properties are most promising for improving the sensitivity and multiplexing capabilities of molecular histopathology and disease diagnosis. 5 -7 In contrast to in vivo imaging applications, where the potential toxicity of cadmium-containing QDs is a major concern, 4 immunohistological staining is performed on in vitro clinical patient samples. As a result, the use of multicolor QD probes in immunohistochemistry (IHC) is likely one of the most important and clinically relevant applications in the near term. 8 -16 In particular, the multiplexing capability of QDs is well-suited for investigating tumor heterogeneity and complexity, one of the most important and challenging problems in studying the mechanisms of cancer development and also in developing therapeutics to eradicate cancer cells. 16 -18 Human cancer is especially complex because it evolves over a long time course and shows a multitude of molecular, cellular, and architectural heterogeneity. 18 At the molecular ...

The presence of somatic B-catenin mutations in some prostate cancers implies that aberrant WNT signaling is involved in the cancer development. Although B-catenin stability is regulated by a multicomponent destruction complex, mutational alterations of B-catenin or other components of the destruction complexes are rare in prostate tumors. Therefore, B-catenin may be regulated by another protein in the prostate. In fact, recent linkage and somatic deletion analyses in prostate cancers reveal a 1.4-Mb candidate tumor suppressor locus on 8p23.1, which includes the Sox7 gene. Here we show that Sox7 protein expression was indeed down-regulated in 47% (15 of 32) of prostate adenocarcinomas. In addition, Sox7 mRNA was down-regulated in 60% of snap-frozen tumors. This down-regulation was found to be due to tumor-specific promoter hypermethylation, which was present in 48% (10 of 21) of primary prostate tumors and 44% (11 of 25) of prostate cancer cell lines/xenografts. We discovered that Sox7 protein physically interacts with B-catenin and suppresses B-catenin -mediated transcription by depleting active B-catenin. Furthermore, in HCT116 colorectal cancer cell lines with Sox7 inactivation, ectopic Sox7 expression suppressed cell proliferation and inhibited transcription that was activated by an endogenous mutant B-catenin. Although nearly all colorectal cancers contain mutations in B-catenin or adenomatous polyposis coli/axin, epigenetic silencing of Sox7 was still observed. These data suggest that Sox7 is a tumor suppressor that functions as an independent checkpoint for B-catenin transcriptional activity. Inactivation of Sox7 could promote the development of a majority of colorectal tumors and approximately half of prostate tumors.

In fine needle aspirates of cervical lymph nodes with metastatic squamous cell carcinoma (SCC), the site of origin may not be clinically evident. The distinction between oropharyngeal and nasopharyngeal primary SCC has important management consequences. In the current study, we evaluated metastatic SCC for HPV types 16, 18, 31, 33, 51 (by in situ hybridization[ISH]), p16 and ProExC (surrogate HPV markers), and Epstein Barr Virus reported in nasopharyngeal SCC. Forty patients diagnosed between 2004 and 2008, with adequate cell block material were identified. ISH for high risk HPV and EBV (EBER), and immunohistochemistry for p16 and ProExC were performed. Primary site was designated in 31 cases with 26 head and neck including 11 oropharyngeal and 2 nasopharyngeal, and 5 other sites. High risk HPV was detected in 9 cases (22.5%), p16 in 16 (40%), ProExC in 35 (87.5%), and EBER in 2 (5%). All cases with high risk HPV ISH also showed overexpression of p16. The sensitivity for HPV infection by both surrogate markers was 100%; specificity for p16 and ProExC was 78.7 and 16.1%, respectively. Seven (63.6%) oropharyngeal SCC were positive for HPV ISH and negative for EBV; one nasopharyngeal SCC (50%) was EBER positive and HPV negative. HPV and EBER detection can serve as indicators for oropharyngeal and nasopharyngeal primary SCC, respectively, however our data show that only a subset (63.6%) of oropharyngeal SCC are high risk HPV-related. Additionally, despite their high sensitivity for HPV infection, surrogate markers, especially ProExC, lack specificity.