Deficient Pms2, ERCC1, Ku86, CcOI in Field Defects During Progression to Colon Cancer

In carcinogenesis, the "field defect" is recognized clinically because of the high propensity of survivors of certain cancers to develop other malignancies of the same tissue type, often in a nearby location. Such field defects have been indicated in colon cancer. The molecular abnormalities that are responsible for a field defect in the colon should be detectable at high frequency in the histologically normal tissue surrounding a colonic adenocarcinoma or surrounding an adenoma with advanced neoplasia (well on the way to a colon cancer), but at low frequency in the colonic mucosa from patients without colonic neoplasia

ELUCIDATING THE ROLE OF PRIMARY CILIA AS PUTATIVE TUMOR SUPPRESSORS IN THE PROSTATE AND BREAST

Prostate and breast cancer are among the most commonly diagnosed cancers and leading causes of cancer-related deaths in men and women worldwide. It is therefore evident that enhanced understanding of tumorigenesis is required to improve diagnostic tools, improve prognostics and identify novel therapeutic targets. The goal of this dissertation was to elucidate the role of primary cilia in prostate and breast cancer. Little is known about the role primary cilia may play in these cancers. Primary cilia are microtubule-based organelles which aid in sensing the extracellular environment and participate in signal transduction. Important developmental signaling pathways, such as Hedgehog (Hh) and Wnt signaling pathways, involve cilia. These pathways have also been implicated in prostate and breast cancer. In this work, we demonstrate that cilia are lost through prostate cancer progression. The few remaining cilia on prostate cancers appeared to be dysfunctional, as assessed by quantifying cilia lengths, an indirect measure of functionality. We also investigated a link between the observed cilia loss and canonical Wnt signaling in prostate cancers. Primary cilia have been determined to have a suppressive role in Wnt signaling, therefore we predicted loss of cilia to correlate with increased Wnt signaling. A link between cilia loss or shortened cilia and activated Wnt signaling was suggested in a subset of prostate cancers. Our lab has established that cilia are similarly lost in breast cancer. These data suggested the hypothesis that cilia may act as tumor suppressor organelles in the prostate and breast. To test this hypothesis, we knocked down cilia in an oncogenic mammary mouse model and assessed changes in tumor growth and characteristics. We observed enhanced tumor growth with cilia loss. The data supports the hypothesis that primary cilia may be playing a tumor suppressor role in the prostate and breast, and provides promising avenues for identifying novel therapeutic approaches for cancer patients.Dissertation not available, per author's request

Loss of primary cilia occurs early in breast cancer development

BACKGROUND:Primary cilia are microtubule-based organelles that protrude from the cell surface. Primary cilia play a critical role in development and disease through regulation of signaling pathways including the Hedgehog pathway. Recent mouse models have also linked ciliary dysfunction to cancer. However, little is known about the role of primary cilia in breast cancer development. Primary cilia expression was characterized in cancer cells as well as their surrounding stromal cells from 86 breast cancer patients by counting cilia and measuring cilia length. In addition, we examined cilia expression in normal epithelial and stromal cells from reduction mammoplasties as well as histologically normal adjacent tissue for comparison.RESULTS:We observed a statistically significant decrease in the percentage of ciliated cells on both premalignant lesions as well as in invasive cancers. This loss of cilia does not correlate with increased proliferative index (Ki67-positive cells). However, we did detect rare ciliated cancer cells present in patients with invasive breast cancer and found that these express a marker of basaloid cancers that is associated with poor prognosis (Cytokeratin 5). Interestingly, the percentage of ciliated stromal cells associated with both premalignant and invasive cancers decreased when compared to stromal cells associated with normal tissue. To understand how cilia may be lost during cancer development we analyzed the expression of genes required for ciliogenesis and/or ciliary function and compared their expression in normal versus breast cancer samples. We found that expression of ciliary genes were frequently downregulated in human breast cancers.CONCLUSIONS:These data suggest that primary cilia are lost early in breast cancer development on both the cancer cells and their surrounding stromal cells.This item is part of the UA Faculty Publications collection. For more information this item or other items in the UA Campus Repository, contact the University of Arizona Libraries at [email protected]

Primary Cilia Are Lost in Preinvasive and Invasive Prostate Cancer

<div><p>Prostate cancer is the second most commonly diagnosed cancer in men worldwide. Little is known about the role of primary cilia in preinvasive and invasive prostate cancer. However, reduced cilia expression has been observed in human cancers including pancreatic cancer, renal cell carcinoma, breast cancer, cholangiocarcinoma, and melanoma. The aim of this study was to characterize primary cilia expression in preinvasive and invasive human prostate cancer, and to investigate the correlation between primary cilia and the Wnt signaling pathway. Human prostate tissues representative of stages of prostate cancer formation (normal prostate, prostatic intraepithelial neoplasia (PIN), and invasive prostate cancer (including perineural invasion)) were stained for ciliary proteins. The frequency of primary cilia was determined. A decrease in the percentage of ciliated cells in PIN, invasive cancer and perineural invasion lesions was observed when compared to normal. Cilia lengths were also measured to indirectly test functionality. Cilia were shorter in PIN, cancer, and perineural invasion lesions, suggesting dysfunction. Primary cilia have been shown to suppress the Wnt pathway. Increased Wnt signaling has been implicated in prostate cancer. Therefore, we investigated a correlation between loss of primary cilia and increased Wnt signaling in normal prostate and in preinvasive and invasive prostate cancer. To investigate Wnt signaling in our cohort, serial tissue sections were stained for β-catenin as a measure of Wnt signaling. Nuclear β-catenin was analyzed and Wnt signaling was found to be higher in un-ciliated cells in the normal prostate, PIN, a subset of invasive cancers, and perineural invasion. Our results suggest that cilia normally function to suppress the Wnt signaling pathway in epithelial cells and that cilia loss may play a role in increased Wnt signaling in some prostate cancers. These results suggest that cilia are dysfunctional in human prostate cancer, and increase Wnt signaling occurs in a subset of cancers.</p> </div

Ciliated prostate cancer and stromal cells have decreased axoneme lengths.

<p>(A and B) Primary cilia (Ac-Tub; red), centrosomes (γ-Tub; green), nuclei (Hoechst; blue), and cytokeratin 5 (CK5; white), are shown to illustrate representative ciliary lengths. Images were selected to represent the median length for normal and the 25^th percentile for PIN and cancer cells (note that many PIN and cancer cells have cilia shorter than those shown). Cilia lengths are given. (A) Normal basal cell, normal luminal cell, CK5+ basal cell in PIN, CK5-cancer cell and (B) stromal cell in normal, PIN, and cancer tissue. Boxplots of cilia lengths for (C, top) all epithelial, (D, top) CK5+, (E, top) CK5-and (F, top) stromal cells per patient for normal, PIN, cancer (Ca), and perineural invasion (Peri). Q4, Q1 are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068521#pone-0068521-g001" target="_blank">Figure 1</a>. Statistics were performed using linear regression (* = p<0.05, *** = p<0.001) (C, D, E, and F, bottom). The percent of patients with abnormally long cilia (Q4; orange) or abnormally short cilia (Q1; blue).</p

Primary cilia expression is decreased in preinvasive and invasive prostate cancer.

<p>Images of (A) normal prostate and (B) invasive prostate cancer. Serially adjacent slides were stained with H&E to visualize tissue morphology or stained fluorescently for nuclei (Hoechst; blue), primary cilia (Ac-Tub; red) and centrosomes (γ-Tub; green). Labeled structures are lumen (Lum), cancer (Ca), and stroma (Strm). Inset shows magnification of (A) a primary cilium on a normal epithelial cell and (B) a centrosome without a cilium on a cancer cell. Asterisk denotes nonspecific staining (C, top). Box plot of the percent of ciliated epithelial and cancer cells per patient for each tissue type: normal, prostatic intraepithelial neoplasia (PIN), cancer (Ca), and perinerual invasion (Peri). Orange line and arrow correspond to Q4 (quartile 4; greater than the 75^th percentile for normal tissue) and blue line and arrow correspond to Q1 (quartile 1; less than or equal to the 25^th percentile for normal tissue). Statistics were performed using linear regression (*** = p<0.001) (C, bottom). The percent of patients with an abnormally high percent cilia (Q4; orange) or an abnormally low percent cilia (Q1; blue). (D) Percent of Ki67 positive invasive cancer cells and perineural invasion cancer cells per patient (x-axis) versus percent ciliated cancer cells for the same patient (y-axis). Statistical analysis was a non-parametric spearman correlation.</p

Primary cilia loss correlates with greater nuclear β-catenin in normal.

<p>(A) Immunohistochemistry (IHC) images of β-catenin staining in normal prostate, demonstrate a lack of β-catenin localization in basal cells (blue nuclei, black arrows; left). Basal cells were identified based on position, morphology, and cytokeratin 5 (CK5) staining in the adjoining serial section (white arrows; right). The lumen (Lum) and stroma (Strm) are labeled. IHC images show different levels and spatial distributions of β-catenin staining in (B) PIN, (C) cancer, and (D) perineural invasion. (E) Graphs display percent ciliated cells versus β-catenin nuclear score. Scattergraphs were plotted per location for normal, PIN, cancer, and perineural invasion tissue. For normal, basal cells (green) and luminal cells (blue) are shown. For PIN, cancer and perineural invasion, all epithelial/cancer cells are plotted red. High nuclear β-catenin was defined as the 75^th percentile of normal, denoted by the dotted line, and was used to compare normal to PIN, cancer and perineural cells. Percentages represent the locations with high nuclear β-catenin. Statistical analysis was performed using linear regression and included all of the data points, and comparisons to normal basal cells are denoted with p, and comparisons to normal luminal cells are denoted with p*.</p

Frequency of cilia does not change on stromal cells surrounding cancer.

<p>Images of (A) normal prostate and (B) prostate cancer show nuclei (Hoechst; blue), cytokeratin 5 (CK5; white), primary cilia (Ac-Tub; red) and centrosomes (γ-Tub; green). Inset shows magnification of primary cilia on stromal cells associated with (A) normal tissue and (B) cancerous tissue (C, top). Boxplot describe the percent ciliated stromal cells per patient for each tissue type: normal, prostatic intraepithelial neoplasia (PIN), cancer (Ca), and perineural invasion (Peri). Q4, Q1 are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0068521#pone-0068521-g001" target="_blank">Figure 1</a> (C, bottom). The percent of patients with an abnormally high percent cilia (Q4; orange) or an abnormally low percent cilia (Q1; blue).</p

Cancer and age related colonic crypt deficiencies in cytochrome c oxidase I

AIM: To investigate whether deficiency of expression of cytochrome c oxidase I (CcOI) in colonic crypts is associated with colon cancer