Collagen α1(XI) in Normal and Malignant Breast Tissue

Little is known about collagen XI expression in normal and malignant breast tissue. Tissue microarrays, constructed from 72 patients with breast carcinoma and matched normal tissue, were immunohistochemically stained with five antisera against isoform-specific regions of collagen α1(XI) N-terminal domain. Staining intensity was graded on a 0–3 scale in epithelial cytoplasm, stroma, and endothelial staining of the vasculature of each tissue core. The staining was compared to known pathologic parameters: age, tumor size, overall tumor grade, nuclear grade, tubule formation, mitotic counts, angiolymphatic invasion, node status, estrogen receptor status, progesterone receptor status, and HER-2/neu status. Estrogen and progesterone receptor status were used as a control for comparison. With antisera V1a and amino propeptide (Npp), stroma surrounding cancerous cells was found to have decreased collagen α1(XI) staining compared to stroma adjacent to normal epithelium (P=0.0006, P\u3c 0.0001). Collagen α1(XI) staining with V1a antiserum in cytoplasm of cancer cells demonstrated decreased intensity in metastasized primary tumors when compared to nonmetastasized primary tumors (P=0.009). Cytoplasmic staining with Npp antiserum in cancer demonstrated an inverse relationship to positive estrogen receptor status in cancer (P=0.012) and to progesterone receptor status (P=0.044). Stromal staining for Npp in cancerous tissue demonstrated an inverse relationship with tubule formation score (P=0.015). This is the first study to localize collagen XI within normal and malignant breast tissue. Collagen α1(XI) appears to be downregulated in stroma surrounding breast cancer. Detection of collagen XI in breast tissue may help predict women who have lymph node metastases

Immunohistochemical Localization of Collagen Type XI α1 and α2 Chains in Human Colon Tissue

In previous studies, collagen XI mRNA has been detected in colon cancer, but its location in human colon tissue has not been determined. The heterotrimeric collagen XI consists of three α chains. While it is known that collagen XI plays a regulatory role in collagen fibril formation, its function in the colon is unknown. The characterization of normal human colon tissue will allow a better understanding of the variance of collagen XI in abnormal tissues. Grossly normal and malignant human colon tissue was obtained from pathology archives. Immunohistochemical staining with a 58K Golgi marker and α1(XI) and α2(XI) antisera was used to specifically locate their presence in normal colon tissue. A comparative bright field microscopic analysis showed the presence of collagen XI in human colon. The juxtanuclear, dot-like collagen XI staining in the Golgi apparatus of goblet cells in normal tissue paralleled the staining of the 58K Golgi marker. Ultra light microscopy verified these results. Staining was also confirmed in malignant colon tissue. This study is the first to show that collagen XI is present in the Golgi apparatus of normal human colon goblet cells and localizes collagen XI in both normal and malignant tissue. Although the function of collagen XI in the colon is unknown, our immunohistochemical characterization provides the foundation for future immunohistopathology studies of the colon. (J Histochem Cytochem 56:275–283, 2008

A tissue biopsy-based epigenetic multiplex PCR assay for prostate cancer detection

<p>Abstract</p> <p>Background</p> <p>PSA-directed prostate cancer screening leads to a high rate of false positive identifications and an unnecessary biopsy burden. Epigenetic biomarkers have proven useful, exhibiting frequent and abundant inactivation of tumor suppressor genes through such mechanisms. An epigenetic, multiplex PCR test for prostate cancer diagnosis could provide physicians with better tools to help their patients. Biomarkers like <it>GSTP1</it>, <it>APC</it> and <it>RASSF1</it> have demonstrated involvement with prostate cancer, with the latter two genes playing prominent roles in the field effect. The epigenetic states of these genes can be used to assess the likelihood of cancer presence or absence.</p> <p>Results</p> <p>An initial test cohort of 30 prostate cancer-positive samples and 12 cancer-negative samples was used as basis for the development and optimization of an epigenetic multiplex assay based on the <it>GSTP1</it>, <it>APC</it> and <it>RASSF1</it> genes, using methylation specific PCR (MSP). The effect of prostate needle core biopsy sample volume and age of formalin-fixed paraffin-embedded (FFPE) samples was evaluated on an independent follow-up cohort of 51 cancer-positive patients. Multiplexing affects copy number calculations in a consistent way per assay. Methylation ratios are therefore altered compared to the respective singleplex assays, but the correlation with patient outcome remains equivalent. In addition, tissue-biopsy samples as small as 20 μm can be used to detect methylation in a reliable manner. The age of FFPE-samples does have a negative impact on DNA quality and quantity.</p> <p>Conclusions</p> <p>The developed multiplex assay appears functionally similar to individual singleplex assays, with the benefit of lower tissue requirements, lower cost and decreased signal variation. This assay can be applied to small biopsy specimens, down to 20 microns, widening clinical applicability. Increasing the sample volume can compensate the loss of DNA quality and quantity in older samples.</p