Purpose: We investigated the contribution of Sonic hedgehog (SHH) to pancreatic cancer progression. Experimental Design: We expressed SHH in a transformed primary ductal-derived epithelial cell line from the human pancreas, transformed hTert-HPNE (T-HPNE), and evaluated the effects on tumor growth.We also directly inhibited the activity of SHH in vivo by administering a blocking antibody to mice challenged orthotopically with the Capan-2 pancreatic cancer cell line, which is known to express SHH and form moderately differentiated tumors in nude mice. Results: Our data provide evidence that expression of SHH influences tumor growth by contributing to the formation of desmoplasia in pancreatic cancer. We further show that SHH affects the differentiation and motility of human pancreatic stellate cells and fibroblasts. Conclusions: These data suggest that SHH contributes to the formation of desmoplasia in pancreatic cancer, an important component of the tumor microenvironment.Pancreatic cancer is the fourth leading cause of cancer-related deaths in the United States, resulting in 30,000 deaths each year, in part because it is one of the most lethal cancers with a death-to-incidence ratio of 0.99 (1). The lethality of pancreatic cancer is largely due to late stage of diagnosis and resistance to current therapies. More than 80% of patients are unresectable and most present with metastatic disease due to aggressive localized invasion and a high incidence of early metastasis (2). Worldwide, the incidence of death from pancreatic cancer has increased, which, together with the lack of current therapies, emphasizes the need to determine the mechanisms of pancreatic cancer progression and better targets for diagnosis and treatment.The current model of pancreatic cancer progression includes mutations that activate K-ras, followed by inactivating mutations or loss of expression of tumor suppressor genes including p53, p16INK4A , and SMAD4 (3). Sonic hedgehog (SHH) and other proteins downstream of the hedgehog pathway were recently detected in precursor lesions and samples of primary tumors from patients with pancreatic adenocarcinoma, which implicates this pathway in the initiation and progression of pancreatic cancer given its absence in normal adult pancreas (4, 5). Transgenic mouse models in which SHH was expressed in mouse pancreatic epithelium, in concert with activated Ras signaling, enhanced the formation of pancreatic intraepithelial neoplasia and accelerated lethality, further supporting a role for hedgehog as an early contributor to this lethal disease (6). We investigated the contribution of SHH to pancreatic cancer progression by expressing SHH in a transformed primary ductal-derived epithelial cell line from the human pancreas, transformed hTert-HPNE (T-HPNE), which was described previously (7,8). This cell line has been documented to represent an appropriate and important model system to delineate signaling mechanisms for Ras-mediated oncogenesis and growth of pancreatic ductal epithelial cells (8), and...
MUC1 is a transmembrane mucin that is highly expressed in various cancers and correlates with malignant potential. Important cancer-related genes such as p16 and E-cadherin are controlled epigenetically; however, MUC1 has been overlooked in epigenetics. Herein, we provide the first report that MUC1 gene expression is regulated by DNA methylation and histone H3 lysine 9 (H3-K9) modification of the MUC1 promoter. The recently developed MassARRAY assay was performed to investigate the DNA methylation status of 184 CpG sites from À2,753 to +263. Near the transcriptional start site, the DNA methylation level of MUC1-negative cancer cell lines (e.g., MDA-MB-453) was high, whereas that of MUC1-positive cell lines (e.g., MCF-7) was low. Histone H3-K9 modification status was also closely related to MUC1 gene expression. Furthermore, MUC1 mRNA expression in MUC1-negative cells was restored by treatment with the DNA methylation inhibitor 5-aza-2 ¶-deoxycytidine. Our results indicate that DNA methylation and histone H3-K9 modification in the 5 ¶ flanking region play a critical role in MUC1 gene expression, and this study defines MUC1 as a new member of the class of epigenetically controlled genes. An understanding of the epigenetic changes of MUC1 may be of importance for diagnosis of carcinogenic risk and prediction of outcome for cancer patients.
Oral hypofunction is a new concept that addresses the oral function of older adults. Few studies have investigated the relationship between oral hypofunction and general health conditions such as frailty, sarcopenia, and mild cognitive impairment. This paper explores these relationships in a large-scale, cross-sectional cohort study. The relationships of oral hypofunction with frailty, sarcopenia, and mild cognitive impairment were examined using data from 832 individuals who participated in the 2018 health survey of the residents of Tarumizu City, Kagoshima Prefecture, Japan. Individuals with frailty, sarcopenia, and mild cognitive impairment had significantly higher rates of oral hypofunction. Frailty was independently associated with deterioration of the swallowing function (odds ratio 2.56; 95% confidence interval, 1.26–5.20), and mild cognitive impairment was independently associated with reduced occlusal force (odds ratio 1.48; 95% confidence interval, 1.05–2.08) and decreased tongue pressure (odds ratio 1.77; 95% confidence interval, 1.28–2.43). There was no independent association found between sarcopenia and oral function. In conclusion, early intervention for related factors such as deterioration of the swallowing function in frailty, reduced occlusal force, and decreased tongue pressure in mild cognitive impairment could lead to the prevention of general hypofunction in older adults.
To equalize X-linked gene dosage between the sexes in mammalian females, Xist RNA inactivates one of the two X-chromosomes. Here, we report the crucial function of Xist exon 7 in X-inactivation. Xist exon 7 is the second-largest exon with a well-conserved repeat E in eutherian mammals, but its role is often overlooked in X-inactivation. Although female ES cells with a targeted truncation of the Xist exon 7 showed no significant differences in their Xist expression levels and RNA stability from control cells expressing wild-type Xist, compromised localization of Xist RNA and incomplete silencing of X-linked genes on the inactive X-chromosome (Xi) were observed in the exon 7-truncated mutant cells. Furthermore, the interaction between the mutant Xist RNA and hnRNP U required for localization of Xist RNA to the Xi was impaired in the Xist exon 7 truncation mutant cells. Our results suggest that exon 7 of Xist RNA plays an important role for stable Xist RNA localization and silencing of the X-linked genes on the Xi, possibly acting through an interaction with hnRNP U.
Mucins are highly glycosylated proteins that play important roles in carcinogenesis. In pancreatic neoplasia, MUC2 mucin has been demonstrated as a tumor suppressor and we have reported that MUC2 is a favorable prognostic factor. Regulation of MUC2 gene expression is known to be controlled by DNA methylation, but the role of histone modification for MUC2 gene expression has yet to be clarified. Herein, we provide the first report that the histone H3 modification of the MUC2 promoter region regulates MUC2 gene expression. To investigate the histone modification and DNA methylation of the promoter region of the MUC2 gene, we treated 2 human pancreatic cancer cell lines, PANC1 (MUC2-negative) and BxPC3 (MUC2-positive) with the DNA methyltransferase inhibitor 5-azacytidine (5-aza), the histone deacetylase inhibitor trichostatin A (TSA), and a combination of these agents. The DNA methylation level of PANC1 cells was decreased by all 3 treatments, whereas histone H3-K4/K9 methylation and H3-K9/K27 acetylation in PANC1 cells was changed to the level in BxPC3 cells by treatment with TSA alone and with the 5-aza/TSA combination. The expression level of MUC2 mRNA in PANC1 cells exhibited a definite increase when treated with TSA and 5-aza/TSA, whereas 5-aza alone induced only a slight increase. Our results suggest that histone H3 modification in the 5 0 flanking region play an important role in MUC2 gene expression, possibly affecting DNA methylation. An understanding of these intimately correlated epigenetic changes may be of importance for predicting the outcome of patients with pancreatic neoplasms. ' 2006 Wiley-Liss, Inc.
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