Colon adenocarcinomas are known to express elevated levels of A2-6 sialylation and increased activity of ST6Gal-I, the Golgi glycosyltransferase that creates A2-6 linkages. Elevated ST6Gal-I positively correlates with metastasis and poor survival, and therefore ST6Gal-I-mediated hypersialylation likely plays a role in colorectal tumor invasion. Previously we found that oncogenic ras (present in roughly 50% of colon adenocarcinomas) up-regulates ST6Gal-I and, in turn, increases sialylation of B 1 integrin adhesion receptors in colon epithelial cells. However, we wanted to know if this pattern held true in vivo and, if so, how B 1 hypersialylation might contribute to colon tumor progression. In the present study, we find that B 1 integrins from colon adenocarcinomas consistently carry higher levels of A2-6 sialic acid. To explore the effects of increased A2-6 sialylation on B 1 -integrin function, we stably expressed ST6Gal-I in a colon epithelial cell line lacking endogenous ST6Gal-I. ST6Gal-I expressors (with A2-6 sialylated B 1 integrins) exhibited up-regulated attachment to collagen I and laminin and increased haptotactic migration toward collagen I, relative to parental cells (with completely unsialylated B 1 integrins). Blockade of ST6Gal-I expression with short interfering RNA reversed collagen binding back to the level of ST6Gal-I nonexpressors, confirming that a2-6 sialylation regulates B 1 integrin function. Finally, we show that B 1 integrins from ST6Gal-I expressors have increased association with talin, a marker for integrin activation. Collectively, these findings suggest that B 1 hypersialylation may augment colon tumor progression by altering cell preference for certain extracellular matrix milieus, as well as by stimulating cell migration. (Cancer Res 2005; 65(11): 4645-52)

Objective A meta-analysis has not been previously performed to evaluate critically the diagnostic accuracy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of solely pancreatic ductal adenocarcinoma and address factors that have an impact on variability of accuracy. The aim of this study was to determine whether the presence of a cytopathologist, variability of the reference standard and other sources of heterogeneity significantly impacts diagnostic accuracy. Methods We conducted a comprehensive search to identify studies, in which the pooled sensitivity, specificity, likelihood ratios for a positive or negative test (LR+, LR−) and summary receiver-operating curves (SROC) could be determined for EUS-FNA of the pancreas for ductal adenocarcinoma using clinical follow-up, and/or surgical biopsy or excision as the reference standard. Results We included 34 distinct studies (3644 patients) in which EUS-FNA for a solid pancreatic mass was evaluated. The pooled sensitivity and specificity for EUS-FNA for pancreatic ductal adenocarcinoma was 88.6% [95% confidence interval (CI): 87.2–89.9] and 99.3% (95% CI: 98.7–99.7), respectively. The LR+ and LR− were 33.46 (95% CI: 20.76–53.91) and 0.11 (95% CI: 0.08–0.16), respectively. The meta-regression model showed rapid on-site evaluation (ROSE) (P = 0.001) remained a significant determinant of EUS-FNA accuracy after correcting for study population number and reference standard. Conclusion EUS-FNA is an effective modality for diagnosing pancreatic ductal adencarcinoma in solid pancreatic lesions, with an increased diagnostic accuracy when using on-site cytopathology evaluation.

KLF4/GKLF normally functions in differentiating epithelial cells, but also acts as a transforming oncogene in vitro.To examine the role of this zinc finger protein in skin, we expressed the wild-type human allele from inducible and constitutive promoters. When induced in basal keratinocytes, KLF4 rapidly abolished the distinctive properties of basal and parabasal epithelial cells. KLF4 caused a transitory apoptotic response and the skin progressed through phases of hyperplasia and dysplasia. By 6 weeks, lesions exhibited nuclear KLF4 and other morphologic and molecular similarities to squamous cell carcinoma in situ. p53 determined the patch size sufficient to establish lesions, as induction in a mosaic pattern produced skin lesions only when p53 was deficient. Compared with p53 wild-type animals, p53 hemizygous animals had early onset of lesions and a pronounced fibrovascular response that included outgrowth of subcutaneous sarcoma. A KLF4-estrogen receptor fusion protein showed tamoxifendependent nuclear localization and conditional transformation in vitro. The results suggest that KLF4 can function in the nucleus to induce squamous epithelial dysplasia, and indicate roles for p53 and epithelialmesenchymal signaling in these early neoplastic lesions.

Purpose: The Krü ppel-like transcription factor KLF4/ GKLF induces both malignant transformation and a slowgrowth phenotype in vitro. Although KLF4 expression is increased in most cases of breast cancer, it was unknown whether these cases represent a distinct subtype with a different clinical outcome.Experimental Design: We examined expression of KLF4 by immunostaining 146 cases of human primary infiltrating ductal carcinoma of the breast. Staining patterns were correlated with clinical outcome and with established prognostic factors.Results: Subcellular localization exhibited case-to-case variation. Tumors with high nuclear staining and low cytoplasmic staining were termed type 1. For patients with early-stage disease (i.e., stage I or IIA), type 1 staining was associated with eventual death because of breast cancer (hazard ratio, 2.8; 95% confidence interval, 1.23-6.58; P ‫؍‬ 0.011). The association was stronger in patients with earlystage cancer and small primary tumors (i.e., <2.0 cm in diameter; hazard ratio, 4.3; 95% confidence interval, 1.75-10.62; P < 0.001). For patients with early-stage disease, multivariate analysis indicated that type 1 staining was independently associated with outcome (adjusted hazard ratio 2.6; 95% confidence interval, 1.10 -6.05; P ‫؍‬ 0.029). Type 1 staining was also associated with high histological grade (P ‫؍‬ 0.032), increased expression of Ki67 (P ‫؍‬ 0.016), and reduced expression of BCL2 (P ‫؍‬ 0.032). In vitro, KLF4 was localized within the nucleus of transformed RK3E epithelial cells, consistent with a nuclear function of this transcription factor during induction of malignant transformation.Conclusions: The results suggest that localization of KLF4 in the nucleus of breast cancer cells is a prognostic factor and identify KLF4 as a marker of an aggressive phenotype in early-stage infiltrating ductal carcinoma.

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KISS1 secretion was required for multiple organ metastasis suppression and for maintenance of disseminated cells in a dormant state. The absence of GPR54 expression in C8161.9 cells (whose metastatic spread was suppressed by KFM) suggests that metastasis suppression is not mediated through this receptor. The results imply the existence of another KISS1 receptor and/or paracrine signaling. The findings raise the possibility that soluble KISS1, kisspeptins, or mimetics could be used to maintain tumor dormancy, rendering treatment of already disseminated tumor cells (i.e., micrometastases) a legitimate target.

S U M M A R Y Primary cilia (PC) are solitary, sensory organelles that are critical for several signaling pathways. PC were detected by immunofluorescence of cultured cells and breast tissues. After growth for 7 days in vitro, PC were detected in ?70% of breast fibroblasts and in 7-19% of epithelial cells derived from benign breast (184A1 and MCF10A). In 11 breast cancer cell lines, PC were present at a low frequency in four (from 0.3% to 4% of cells), but were absent in the remainder. The cancer cell lines with PC were all of the basal B subtype, which is analogous to the clinical triple-negative breast cancer subtype. Furthermore, the frequency of PC decreased with increasing degree of transformation/progression in the MCF10 and MDA-MB-435/LCC6 isogenic models of cancer progression. In histologically normal breast tissues, PC were frequent in fibroblasts and myoepithelial cells and less common in luminal epithelial cells. Of 26 breast cancers examined, rare PC were identified in cancer epithelial cells of only one cancer, which was of the triple-negative subtype. These data indicate a decrease or loss of PC in breast cancer and an association of PC with the basal B subtype. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials. (J Histochem Cytochem 58:857-870, 2010)

BACKGROUNDThe expression of human endogenous retrovirus (HERV) mRNA and proteins was associated recently with diseases that include human malignancies. The authors report that, in the current study, transcripts encoding the envelope region of an HERV family, HERV‐E, were expressed in human prostate carcinoma.METHODSRNA was isolated from various prostate tissues and was tested for the expression of various HERV envelope (env) genes by reverse transcriptase–polymerase chain reaction (RT‐PCR) analysis, RNA in situ hybridization (ISH), and Northern blot analysis. Variants of HERV that appeared in prostate carcinoma tissues were sequenced, and HERV‐E was expressed in prokaryotic and eukaryotic systems.RESULTSIn the current study, the authors found that the mRNA of the env gene of one particular family of HERVs, HERV‐E, was expressed in some prostate carcinoma tissues (38.8% positive; n = 49 specimens) but not in normal prostate tissues using RT‐PCR, RNA ISH, and Northern blot assays. The expression of HERV‐E transcripts in prostate tumor epithelial cells was confirmed further by ISH using an HERV‐E specific antisense probe. Approximately 50% of the cDNA of HERV‐E obtained from prostate carcinoma specimens contained no stop codon and expressed proteins in prokaryotic or eukaryotic expression systems. Furthermore, the expression of both HERV‐E and ERV3 (another class of HERV) was detected in the same prostate carcinoma tissues.CONCLUSIONSThe expression and distribution of multiple HERV‐E endogenous retroviral elements in prostate carcinoma, but not in normal control specimens, suggests that they may serve as novel tumor markers for the early diagnosis and immunotherapy of patients with prostate carcinoma. Cancer 2003;98:187–97. © 2003 American Cancer Society.DOI 10.1002/cncr.11451