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Joseph Willis

Publications and source records attributed to Joseph Willis.

At least 19 recordsLinked to original sources
PubMed2006

A case of Churg-Strauss syndrome associated with antiphospholipid antibodies.

Churg-Strauss syndrome (CSS) is a systemic vasculitis affecting both small- and medium-sized blood vessels, almost invariably affecting the lung, and frequently associated with cutaneous involvement. Microvascular vaso-occlusion leading to digital gangrene is not a feature of CSS. We report an unusual case of a patient with CSS with antiphospholipid antibodies who developed severe digital gangrene in addition to cutaneous vasculitis. The presence of antiphospholipid antibodies is not a feature usually seen in association with CSS. While the full clinical spectrum of CSS is still being defined, the identification of additional features associated with this syndrome might help to better understand the pathogenesis of the disease and to have an impact on both management and prognosis.

Antibodies, Antiphospholipid↗
PubMed2006

The consensus coding sequences of human breast and colorectal cancers.

The elucidation of the human genome sequence has made it possible to identify genetic alterations in cancers in unprecedented detail. To begin a systematic analysis of such alterations, we determined the sequence of well-annotated human protein-coding genes in two common tumor types. Analysis of 13,023 genes in 11 breast and 11 colorectal cancers revealed that individual tumors accumulate an average of approximately 90 mutant genes but that only a subset of these contribute to the neoplastic process. Using stringent criteria to delineate this subset, we identified 189 genes (average of 11 per tumor) that were mutated at significant frequency. The vast majority of these genes were not known to be genetically altered in tumors and are predicted to affect a wide range of cellular functions, including transcription, adhesion, and invasion. These data define the genetic landscape of two human cancer types, provide new targets for diagnostic and therapeutic intervention, and open fertile avenues for basic research in tumor biology.

Amino Acid Substitution↗
PubMed2006

15-Hydroxyprostaglandin dehydrogenase is an in vivo suppressor of colon tumorigenesis.

15-Hydroxyprostaglandin dehydrogenase (15-PGDH) is a prostaglandin-degrading enzyme that is highly expressed in normal colon mucosa but is ubiquitously lost in human colon cancers. Herein, we demonstrate that 15-PGDH is active in vivo as a highly potent suppressor of colon neoplasia development and acts in the colon as a required physiologic antagonist of the prostaglandin-synthesizing activity of the cyclooxygenase 2 (COX-2) oncogene. We first show that 15-PGDH gene knockout induces a marked 7.6-fold increase in colon tumors arising in the Min (multiple intestinal neoplasia) mouse model. Furthermore, 15-PGDH gene knockout abrogates the normal resistance of C57BL/6J mice to colon tumor induction by the carcinogen azoxymethane (AOM), conferring susceptibility to AOM-induced adenomas and carcinomas in situ. Susceptibility to AOM-induced tumorigenesis is mediated by a marked induction of dysplasia, proliferation, and cyclin D1 expression throughout microscopic aberrant crypt foci arising in 15-PGDH null colons and is concomitant with a doubling of prostaglandin E(2) in 15-PGDH null colonic mucosa. A parallel role for 15-PGDH loss in promoting the earliest steps of colon neoplasia in humans is supported by our finding of a universal loss of 15-PGDH expression in microscopic colon adenomas recovered from patients with familial adenomatous polyposis, including adenomas as small as a single crypt. These models thus delineate the in vivo significance of 15-PGDH-mediated negative regulation of the COX-2 pathway and moreover reveal the particular importance of 15-PGDH in opposing the neoplastic progression of colonic aberrant crypt foci.

Animals↗
PubMed2006

CpG island methylation of genes accumulates during the adenoma progression step of the multistep pathogenesis of colorectal cancer.

Genetic alterations occur during the adenoma-carcinoma sequence of colon cancer formation and drive the initiation and progression of colon cancer formation. The aberrant methylation of genes is an alternate, epigenetic mechanism for silencing tumor suppressor genes in colon cancer. The aim of this study was to determine on a global and gene-specific level the role of CpG island methylation in the initiation and progression of colon cancer. Consequently, we assessed the frequency of gene methylation in tumors representative of the commonly recognized histological steps of the adenoma-carcinoma progression sequence through the analysis of eight genes previously identified to be methylated in colon cancer, MGMT, HLTF, MLH1, p14(ARF), CDKN2A, TIMP3, THBS1, and CDH1. We observed that the proportion of tumors carrying methylated alleles increased from adenomas to adenocarcinomas but that the proportion of tumors with methylated alleles was not different between adenocarcinomas and metastases (69% versus 90%, P = 0.01 and 90% versus 81%, P > 0.05). The most substantial difference occurred between early and advanced adenomas (47% versus 84%, P = 0.018). Furthermore, we observed that the frequency of gene methylation at the different steps of the progression sequence varied between genes. Thus, the aberrant methylation of genes appears to increase most significantly during the progression of early adenomas to advanced adenomas, and the frequency of specific gene methylation at the different steps of the adenoma-carcinoma progression sequence varies in a gene-specific fashion.

Adenocarcinoma↗
PubMed2005

Molecular classification of patients with unexplained hamartomatous and hyperplastic polyposis.

CONTEXT: Significant proportions of patients with hamartomatous polyposis or with hyperplastic/mixed polyposis remain without specific clinical and molecular diagnosis or present atypically. Assigning a syndromic diagnosis is important because it guides management, especially surveillance and prophylactic surgery. OBJECTIVE: To systematically classify patients with unexplained hamartomatous or hyperplastic/mixed polyposis by extensive molecular analysis in the context of central rereview of histopathology results. DESIGN, SETTING, AND PATIENTS: Prospective, referral-based study of 49 unrelated patients from outside institutions (n = 28) and at a comprehensive cancer center (n = 21), conducted from May 2, 2002, until December 15, 2004. Germline analysis of PTEN, BMPR1A, STK11 (sequence, deletion), SMAD4, and ENG (sequence), specific exon screening of BRAF, MYH, and BHD, and rereview of polyp histology results were performed. MAIN OUTCOME MEASURES: Molecular, clinical, and histopathological findings in patients with unexplained polyposis. RESULTS: Of the 49 patients, 11 (22%) had germline mutations. Of 14 patients with juvenile polyposis, 2 with early-onset disease had mutations in ENG, encoding endoglin, previously only associated with hereditary hemorrhagic telangiectasia; 1 had hemizygous deletion encompassing PTEN and BMPR1A; and 1 had an SMAD4 mutation. One individual previously classified with Peutz-Jeghers syndrome had a PTEN deletion. Among 9 individuals with an unknown hamartomatous polyposis, 4 had mutations in STK11 (1), BMPR1A (2), and SMAD4 (1). Of the 23 patients with hyperplastic/mixed polyposis, 2 had PTEN mutations. Substantial discrepancies in histopathology results were seen. CONCLUSIONS: Systematic molecular classification of 49 patients with unexplained hamartomatous or hyperplastic polyposis uncovered a potential novel susceptibility gene, ENG, for juvenile polyposis. Importantly, given the substantial proportion of patients found to have germline mutations, more extensive analysis of the known susceptibility genes is indicated. Rereview of histology results by a dedicated gastrointestinal pathologist should be considered routinely, as organ-specific surveillance rests on defining syndromic diagnosis.

AMP-Activated Protein Kinase Kinases↗
PubMed2005

Detection in fecal DNA of colon cancer-specific methylation of the nonexpressed vimentin gene.

BACKGROUND: Increased DNA methylation is an epigenetic alteration that is common in human cancers and is often associated with transcriptional silencing. Aberrantly methylated DNA has also been proposed as a potential tumor marker. However, genes such as vimentin, which are transcriptionally silent in normal epithelium, have not until now been considered as targets for cancer-associated aberrant methylation and for use as cancer markers. METHODS: We applied methylation-specific polymerase chain reaction to the vimentin gene, which is transcriptionally silent in normal colonocytes, and compared methylation of vimentin exon 1 in cancer tissues and in fecal DNA from colon cancer patients versus control samples from healthy subjects. RESULTS: Vimentin exon-1 sequences were unmethylated in 45 of 46 normal colon tissues. In contrast, vimentin exon-1 sequences were methylated in 83% (38 of 46) and 53% (57 of 107) of tumors from two independently collected groups of colon cancer patients. When evaluated as a marker for colon cancer detection in fecal DNA from another set of colon cancer patients, aberrant vimentin methylation was detected in fecal DNA from 43 of 94 patients, for a sensitivity of 46% (95% confidence interval [CI] = 35% to 56%). The sensitivity for detecting stage I and II cancers was 43% (26 of 60 case patients) (95% CI = 31% to 57%). Only 10% (20 of 198 case patients) of control fecal DNA samples from cancer-free individuals tested positive for vimentin methylation, for a specificity of 90% (95% CI = 85% to 94%). CONCLUSIONS: Aberrant methylation of exon-1 sequences within the nontranscribed vimentin gene is a novel molecular biomarker of colon cancer and can be successfully detected in fecal DNA to identify nearly half of individuals with colon cancer.

Adenocarcinoma↗
PubMed2005

Correlation of endoscopic optical coherence tomography with histology in the lower-GI tract.

BACKGROUND: Optical coherence tomography (OCT), a noninvasive optical imaging technique, provides high-resolution cross-sectional images of tissue microstructure. We developed a system for real-time endoscopic OCT (EOCT) of the human GI tract. During clinical trials, the structure of mucosa and submucosa, glands, blood vessels, pits, villi, and crypts was observed in a range of GI organs. Although EOCT images are thought to accurately depict actual histologic features, there are few data to support this assumption. Therefore, the present study correlated images acquired with an EOCT imaging system in vitro to corresponding histologic sections. METHODS: EOCT images were obtained of fresh specimens of ileum, colon, and rectum that then were fixed in formalin and were processed for microscopic evaluation by using standard methods. The thickness of mucosa and of submucosa was determined for both EOCT images and histologic slides. RESULTS: The first hyper-reflective layer in the EOCT images was identified as mucosa. A close correlation (R 2=0.84) was observed between EOCT and histology. Furthermore, the submucosa and the muscularis propria could be identified as the next deepest hyporeflective band and a hyper-reflective layer, respectively, in EOCT images. The submucosa was found to be more compressible than mucosa, and its EOCT appearance was dependent on its content of adipose tissue. CONCLUSIONS: EOCT provides images that precisely correlate with the histologic structure of the mucosa and the submucosa of the GI tract.

Colon↗
PubMed2004

15-Hydroxyprostaglandin dehydrogenase, a COX-2 oncogene antagonist, is a TGF-beta-induced suppressor of human gastrointestinal cancers.

Marked increased expression of cyclooxygenase 2 (COX-2), a prostaglandin-synthesizing enzyme that is pharmacologically inhibited by nonsteroid anti-inflammatory-type drugs, is a major early oncogenic event in the genesis of human colon neoplasia. We report that, in addition to inducing expression of COX-2, colon cancers further target the prostaglandin biogenesis pathway by ubiquitously abrogating expression of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), a prostaglandin-degrading enzyme that physiologically antagonizes COX-2. We find that 15-PGDH transcript and protein are both highly expressed by normal colonic epithelia but are nearly undetectable in colon cancers. Using gene transfection to restore 15-PGDH expression in colon cancer cells strongly inhibits the ability of these cells to form tumors in immune-deficient mice and demonstrates 15-PGDH to have functional colon cancer tumor suppressor activity. In interrogating the mechanism for 15-PGDH expression loss in colon cancer, we determined that colonic 15-PGDH expression is directly controlled and strongly induced by activation of the TGF-beta tumor suppressor pathway. These findings thus delineate an enzymatic pathway that induces colon cancer suppression, a pathway that is activated by TGF-beta and mediated by 15-PGDH.

Cell Proliferation↗
PubMed2004

CD40-mediated immune-nonimmune cell interactions induce mucosal fibroblast chemokines leading to T-cell transmigration.

BACKGROUND AND AIMS: The CD40 pathway is a key mediator of inflammation and autoimmunity. We investigated cell adhesion molecule (CAM) up-regulation and chemokine production by CD40-positive human intestinal fibroblasts (HIF) and microvascular endothelial cells (HIMEC) induced by CD40 ligand (CD40L)-positive T cells and soluble CD40L and their effect on T-cell adhesion and transmigration. METHODS: Expression of CD40, CD40L, and CAM was assessed by immunohistochemistry, confocal microscopy and flow cytometric analysis, and chemokine production using enzyme-linked immunosorbent assay. Calcein-labeled T cells were used to assay HIF adhesion and Transwell HIMEC transmigration. RESULTS: Ligation of CD40-positive HIF and HIMEC by CD40L-positive T cells or soluble CD40L induced up-regulation of CAM expression as well as interleukin-8 and RANTES production. The specificity of these responses was shown by inhibition with a CD40L blocking antibody and by CD40 signaling-dependent p38 mitogen-activated protein kinase phosphorylation. On CD40 ligation, HIF increased their T-cell binding capacity and generated chemoattractants able to induce T-cell migration through HIMEC monolayers. CONCLUSIONS: Activation of the CD40/CD40L system in the gut mucosa may trigger a self-sustaining loop of immune-nonimmune cell interactions leading to an antigen-independent influx of T cells that contributes to chronic inflammation.

CD40 Antigens↗
PubMed2004

Identification of Barrett's esophagus in relatives by endoscopic screening.

AIM: Familial aggregation of Barrett's esophagus and its associated cancers has been termed familial Barrett's esophagus (FBE). The aim of the study was to determine whether endoscopic screening would identify Barrett's esophagus (BE) in relatives of probands with BE or esophageal adenocarcinoma (EAC). METHODS: All living first-degree relatives of patients with long segment BE or EAC presenting to the endoscopy suite of two academic hospitals were sent validated questionnaires inquiring about gastroesophageal reflux symptoms and prior endoscopic evaluation. First-degree relatives of affected probands or affected relatives who reported no prior upper endoscopy were offered screening unsedated esophagoscopy. Relatives with chronic gastroesophageal reflux symptoms were also offered an alternative of conventional sedated upper endoscopy. The yield of screening endoscopy was measured. Screening endoscopy findings were then compared between family members of known FBE patients and those with "isolated" disease. RESULTS: One hundred and ninety-eight relatives from 69 families, 23 known FBE probands and 46 probands with apparently "isolated" disease, were enrolled. Forty relatives (29 FBE relatives and 11 relatives of probands with "isolated" disease) reported prior upper endoscopy. Screening upper endoscopies performed on 62 (25 FBE and 37 "isolated" disease relatives) of the remaining 158 relatives identified Barrett's epithelium in 13 (21%). Compared to probands with apparently "isolated" disease, Barrett's epithelium (EAC, BE, or SSBE) was identified significantly more often in siblings and offspring of FBE probands, p</= 0.05. Endoscopic screening of relatives of FBE probands identified a multigeneration multiplex FBE pedigree consistent with an autosomally dominant inherited trait. Endoscopic screening of relatives of probands with reported "isolated" diseased did not identify any new FBE pedigrees. CONCLUSIONS: Endoscopy identified EAC, long-segment BE, and short-segment BE in a substantial proportion of first-degree relatives of affected members of FBE families. A familial susceptibility to develop Barrett's epithelium appears to be present in a subset of patients with BE and EAC.

Adenocarcinoma↗
PubMed2003

A subset of familial colorectal neoplasia kindreds linked to chromosome 9q22.2-31.2.

Colorectal cancer is the second most leading cause of cancer death among adult Americans. Two autosomal dominant hereditary forms of the disease, familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer, together account for perhaps 5% of all cases. However, in approximately 20% of additional colon cancer cases, the affected individuals report a family history of colon cancer in a first-degree relative. Similar familial clusters of colon cancer and early-onset colon adenomas have also been reported. To determine whether such familial aggregations arise by chance or reflect a hereditary colon cancer susceptibility, we conducted a whole genome scan to test for genetic linkage in 53 kindreds in which two or more siblings were affected by age 65 or younger with colon cancer or with advanced colon adenomas that were >1 cm in size or that showed high-grade dysplasia. In this cohort we found genetic linkage of disease (P = 0.00045) to chromosomal region 9q22.2-31.2 in a pattern consistent with autosomal dominant disease alleles. These data suggest that a single locus can contribute to disease susceptibility in a subset of patients with nonsyndromic forms of familial colorectal neoplasia.

Alleles↗
PubMed2003

SLC5A8, a sodium transporter, is a tumor suppressor gene silenced by methylation in human colon aberrant crypt foci and cancers.

We identify a gene, SLC5A8, and show it is a candidate tumor suppressor gene whose silencing by aberrant methylation is a common and early event in human colon neoplasia. Aberrant DNA methylation has been implicated as a component of an epigenetic mechanism that silences genes in human cancers. Using restriction landmark genome scanning, we performed a global search to identify genes that would be aberrantly methylated at high frequency in human colon cancer. From among 1,231 genomic NotI sites assayed, site 3D41 was identified as methylated in 11 of 12 colon cancers profiled. Site 3D41 mapped to exon 1 of SLC5A8, a transcript that we assembled. In normal colon mucosa we found that SLC5A8 exon 1 is unmethylated and SLC5A8 transcript is expressed. In contrast, SLC5A8 exon 1 proved to be aberrantly methylated in 59% of primary colon cancers and 52% of colon cancer cell lines. SLC5A8 exon 1 methylated cells were uniformly silenced for SLC5A8 expression, but reactivated expression on treatment with a demethylating drug, 5-azacytidine. Transfection of SLC5A8 suppressed colony growth in each of three SLC5A8-deficient cell lines, but showed no suppressive effect in any of three SLC5A8-proficient cell lines. SLC5A8 exon 1 methylation is an early event, detectable in colon adenomas, and in even earlier microscopic colonic aberrant crypt foci. Structural homology and functional testing demonstrated that SLC5A8 is a member of the family of sodium solute symporters, which are now added as a class of candidate colon cancer suppressor genes.

Adenocarcinoma↗
PubMed2003

PMEPA1, a transforming growth factor-beta-induced marker of terminal colonocyte differentiation whose expression is maintained in primary and metastatic colon cancer.

To identify potential effectors of transforming growth factor (TGF)-beta-mediated suppression of colon cancer, we used GeneChip expression microarrays to identify TGF-beta-induced genes in VACO 330, a nontransformed TGF-beta-sensitive cell line derived from a human adenomatous colon polyp. PMEPA1 was identified as a gene highly up-regulated by TGF-beta treatment of VACO 330. Northern blot analysis confirmed TGF-beta induction of PMEPA1 in VACO 330, as well as a panel of three other TGF-beta-sensitive colon cell lines. PMEPA1 induction could be detected as early as 2 h after TGF-beta treatment and was not inhibited by pretreatment of cells with cycloheximide, suggesting that PMEPA1 is a direct target of TGF-beta signaling. Wild-type PMEPA1 and an alternative splice variant lacking the putative transmembrane domain were encoded by the PMEPA1 locus and were shown by epitope tagging to encode proteins with differing subcellular localization. Both variants were found to be expressed in normal colonic epithelium, and both were shown to be induced by TGF-beta. Consistent with TGF-beta playing a role in terminal differentiation of colonocytes, in situ hybridization of normal colonic epithelium localized PMEPA1 expression to nonproliferating, terminally differentiated epithelium located at the top of colonic crypts. Intriguingly, in situ hybridization and Northern blot analysis showed that the expression of PMEPA1 was well maintained both in colon cancer primary tumors and in colon cancer liver metastases. PMEPA1 is thus a novel TGF-beta-induced marker of a differentiated crypt cell population. Moreover, as PMEPA1 expression is maintained, presumptively in a TGF-beta-independent manner after malignant transformation and metastasis, it demonstrates that even late colon cancers retain a strong capacity to execute many steps of the normal colonic differentiation program.

Alternative Splicing↗
PubMed2003

A murine model of chronic inflammation-induced intestinal fibrosis down-regulated by antisense NF-kappa B.

BACKGROUND & AIMS: To elucidate extracellular matrix (ECM) changes underlying intestinal fibrosis, a frequent complication of inflammatory bowel disease, we developed a murine model of chronic colitis associated with intestinal fibrosis. METHODS: Chronic inflammation was established by weekly intrarectal administration of trinitrobenzene sulfonic acid (TNBS). In 2 variations of the model an antisense oligonucleotide for nuclear factor kappa B (NF-kappa B) p65 was given prophylactically or therapeutically to block chronic inflammation-associated fibrosis. Colonic inflammation and fibrosis were determined by histology. Total collagen level was estimated by hydroxyproline quantification. Colonic expression of collagens (Col1a2, Col3a2), ECM remodeling genes (matrix metalloproteinase [MMP]-1, -3, and tissue inhibitor of matrix metalloproteinase [TIMP]-1), and inflammation-modulating cytokines (tumor necrosis factor alpha [TNF-alpha], interferon gamma [IFN-gamma], transforming growth factor beta 1 [TGF-beta 1], and insulin-like growth factor 1 [IGF-1]) were assessed by semiquantitative reverse-transcription polymerase chain reaction. Control and TNBS-treated colonic mesenchymal cells were characterized by morphology, phenotype, and functional response to TNF-alpha and IFN-gamma. RESULTS: Colons of TNBS-treated mice contained acute and chronic inflammatory infiltrates, increased collagen, fibrogenic tissue architecture, and increased expression of TNF-alpha, TGF-beta 1, IGF-1, Col1a2, MMP-1, and TIMP-1. Colonic mesenchymal cells from TNBS-treated mice were also morphologically distinct from those of the control mice, with increased TIMP-1 expression in response to IFN-gamma treatment. Fibrosis persisted for 2-4 weeks after cessation of the TNBS treatment. In mice given NF-kappa B antisense prophylactically, 67% were fibrosis-free, whereas of those treated after establishing chronic inflammation, 43% were free of fibrosis. CONCLUSIONS: Extended TNBS treatment of mice yielded chronic intestinal inflammation-associated fibrosis with extensive fibrogenic ECM changes that could be counteracted by specific blockade of NF-kappa B.

Animals↗
PubMed2002

Silence of chromosomal amplifications in colon cancer.

Oncogene activation by gene amplification is a major pathogenetic mechanism in human cancer. Using comparative genomic hybridization, we determined that metastatic human colon cancers commonly acquire numerous extra copies of chromosome arms 7p, 8q, 13q, and 20q. We then examined the consequence of these amplifications on gene expression using DNA microarrays. Of 55,000 transcripts profiled, 2,146 were determined to map to one of the four common colon cancer amplicons and to also be expressed in normal or malignant colon tissues. Of these, only 81 transcripts (3.8%) demonstrated a 2-fold increase over normal expression among cancers bearing the corresponding chromosomal amplification. Chromosomal amplifications are common in colon cancer metastasis, but increased expression of genes within these amplicons is rare.

Colonic Neoplasms↗