Expression of alpha-methylacyl-CoA racemase (P504s) in various malignant neoplasms and normal tissues: astudy of 761 cases

Alpha-methylacyl CoA racemase (AMACR), also known as P504S, plays an important role in peroxisomal beta-oxidation of branched-chain fatty acids. It has recently been shown that AMACR is highly expressed in prostate cancer and that it may be an important diagnostic marker for prostate carcinoma. However, little is known about expression of AMACR in normal tissues and other malignant tumors. In this study, we investigated expression of AMACR in 539 malignant tumors and 222 normal human tissues of various types by immunohistochemical analysis. mRNA levels of AMACR in normal organs and in selected tumors were assessed by real time PCR. In normal tissue, high expression of AMACR mRNA was identified in liver, kidney and salivary gland, while AMACR protein was detected in liver (hepatocytes), kidney (tubular epithelial cells), lung (only bronchial epithelial cells), and gallbladder (only mucosal epithelial cells). High expression of AMACR mRNA was found in prostate, liver, and kidney cancers but rarely in stomach and bladder cancers. A high percent of adenocarcinomas arising from these organs express AMACR, including 17 of 21 (81%) of hepatocellular carcinomas and 18 of 24 (75%) of renal cell carcinomas. In addition, carcinomas arising from tissues normally not expressing AMACR were also positive for the antigen, including 17 of 18 (94%) prostate carcinomas, 9 of 29 (31%) of urothelial carcinomas, and 4 of 15 (27%) of gastric adenocarcinomas. Two hundred and fifty cases of adenocarcinomas from lung, breast, pancreas, bile duct, adrenal gland, salivary gland, ovary, thyroid and endometrium were negative or rarely positive for AMACR. Neuroendocrine carcinomas rarely expressed AMACR. Melanomas, squamous cell carcinomas, basal cell carcinomas, soft tissue tumors (including epithelioid sarcomas and synovial sarcoma), thymomas, and germ cell tumors were negative for AMACR. Our data provide important baseline information for using AMACR in clinical practice and also are valuable in furthering understanding of the pathogenic role of AMACR in malignant neoplasms.     

AMACR is highly expressed in gastric adenomas and intestinal-type carcinomas

Alpha-methylacyl-CoA racemase (AMACR) is a novel tumor biomarker expressed in a number of neoplasms, including colorectal and prostatic adenocarcinomas. However, AMACR expression has not been investigated in preneoplastic and neoplastic lesions of the stomach. Using immunohistochemistry we studied the expression of AMACR in normal gastric mucosa (n=32), intestinal metaplasia (n=26), adenomas (n=29) and adenocarcinomas (n=132) of the stomach from 135 patients. Synchronous adenocarcinomas arising in the background of adenomas were observed in 26 cases. AMACR immunoreactivity was not observed in all normal gastric mucosa. Tissue from intestinal metaplasia, adenomas, and adenocarcinomas was positive in 7.7% (2/26), 79.3% (23/29), and 62.9% (83/132) of cases, respectively. The difference in AMACR expression between adenomas or adenocarcinomas and non-neoplastic mucosa was statistically significant (p=0.0001). Moreover, intestinal-type carcinomas showed significantly higher expression of AMACR (69.8%) compared to diffuse-type carcinomas (47.2%) (p=0.02). Our results indicate that as well as being an additional diagnostic tool, altered AMACR expression in gastric adenomas and intestinal-type carcinomas suggests that AMACR may be involved early in the development of intestinal-type gastric carcinomas.     

Large-scale molecular and tissue microarray analysis of mesothelin expression in common human carcinomas

The 40-kilodalton processed glycoprotein, mesothelin, is highly expressed in epithelial mesotheliomas and adenocarcinomas of the ovary (serous papillary) and pancreas, but its expression in a large series of other common carcinomas has not been completely explored. In the present study, we used oligonucleotide and tissue microarrays to profile the expression of the mesothelin gene (MSLN) and encoded protein, respectively. Among 150 carcinomas of multiple anatomic sites, we found the highest average expression of MSLN in serous carcinomas of the ovary and adenocarcinomas of the pancreas, consistent with previous reports, as well as measurable but less-striking expression in pulmonary, gastric/esophageal, and colorectal adenocarcinomas. On tissue microarrays containing 621 carcinomas derived from the same and additional sites as those profiled by gene expression, mesothelin immunoreactivity was highest in cancers of the ovary (serous papillary, endometrioid, and undifferentiated) and pancreas, with less frequent staining seen in adenocarcinomas of the endometrium, lung, and stomach/esophagus. Some immunopositivity was observed in 42% of pulmonary adenocarcinomas, including 18% that had >50% of tumor cells that were immunoreactive. Some 14% of breast and 30% of colorectal adenocarcinomas showed immunopositivity, but no case contained >50% tumor cells that were immunoreactive. Mesothelin was either entirely absent or present in <5% of carcinomas of the prostate, bladder/ureter, liver, kidney, and thyroid. Overall, we observed good concordance between the results obtained by oligonucleotide and tissue microarrays. This large study of the MSLN gene and protein expression in common carcinomas provides data for future investigations that evaluate the utility of mesothelin/megakaryocyte potentiating factor as a potential serum tumor marker or target of immunotoxin-based therapy in human cancers.     

Galectin-3 does not reliably distinguish benign from malignant thyroid neoplasms

AIMS: To determine whether galectin-3 is a sensitive indicator of thyroid malignancy. It has been suggested as a potential marker for differentiating thyroid carcinoma from benign or non-neoplastic lesions in preoperative fine-needle aspirates (FNAs). METHODS: Galectin-3 protein expression was assessed by immunohistochemistry in formalin-fixed thyroid tissues from 124 patients with histological diagnoses of papillary carcinoma (n = 38), follicular carcinoma (n = 19), follicular adenoma (n = 32) and dominant nodules of multinodular goitre (n = 35). Expression of galectin-3 was also assessed by Western blotting in 24 fresh thyroid tissues. RESULTS: Galectin-3 expression was observed in the majority of carcinomas (papillary 92%; follicular 74%). However, a large proportion of follicular adenomas (72%) and multinodular goitres (57%) also expressed galectin-3. In addition, galectin-3 expression was observed in epithelial cells of normal thyroid tissue and Hashimoto's thyroiditis. Galectin-3 immunopositivity was significantly greater in papillary carcinomas than in dominant nodules or follicular adenomas (P < 0.0001, P = 0.0005, respectively). However, galectin-3 expression was no greater in follicular carcinomas than in follicular adenomas (P = 0.8735). Western blotting analysis confirmed both the specificity of the antiserum and expression of galectin-3 in multinodular goitres, follicular adenomas/carcinomas and papillary carcinomas. CONCLUSION: The data demonstrate that galectin-3 is not a reliable immunohistochemical marker to distinguish benign from malignant thyroid follicular lesions.     

Value of CDX2, villin, and alpha-methylacyl coenzyme A racemase immunostains in the distinction between primary adenocarcinoma of the bladder and secondary colorectal adenocarcinoma.

Primary adenocarcinoma of the urinary bladder is an uncommon neoplasm that can be indistinguishable morphologically from colorectal adenocarcinoma secondarily involving the bladder by direct extension or metastasis. In the current study, 17 enteric-type primary adenocarcinomas of the bladder were immunohistochemically examined for the expression of CDX2, villin and alpha-methylacyl coenzyme A racemase (AMACR), immunomarkers preferentially expressed in colorectal adenocarcinoma. For comparison, 17 secondary colorectal adenocarcinomas involving the bladder, 23 primary colorectal adenocarcinomas and 14 conventional urothelial carcinomas were similarly studied. The results show that all 40 (100%) colorectal adenocarcinomas expressed CDX2 and 39 (98%) expressed villin. The expression of these two immunomarkers was less frequent in primary bladder adenocarcinomas, observed in eight (47%) and 11 (65%) cases, respectively (P<0.0001 and P=0.0019, respectively). The frequency of positive AMACR immunostaining was similar between these two types of tumors, detected in 28 (70%) colorectal adenocarcinomas and 11 (65%) primary bladder adenocarcinomas (P=0.694). None of the urothelial carcinomas exhibited CDX2 or villin immunoreactivity; and only two (14%) showed positive staining for AMACR. These results demonstrate that CDX2 and villin are of diagnostic value in aiding in the distinction between primary adenocarcinoma of the bladder and secondary colorectal carcinoma. Lack of CDX2 and villin signals points strongly to a bladder primary.     

TSH receptor status of thyroid neoplasms—TaqMan RT-PCR analysis of archival material

Regulation of thyroid follicular cell proliferation and function is mediated by the interaction of TSH with its receptor (TSHr) on the plasma membrane. While it is recognized clinically that responsiveness of thyroid epithelial tumours to TSH varies with the histological type and grade of neoplasm, the level of TSHr expression in these different tumours has not been quantified hitherto. The aim of this study was to provide this information. Total RNA was extracted from 125 samples of formalin-fixed, paraffin-embedded thyroid tissue comprising 48 papillary (PTC), 29 follicular (FTC), eight anaplastic (ATC), and five medullary thyroid carcinomas (MTC), in addition to 35 samples of either follicular adenoma (FA) or normal thyroid tissue. Samples were reverse-transcribed and analysed using TaqMan polymerase chain reaction (PCR). TSHr expression was shown to be similar to normal in FA and inversely related to the grade of the majority of thyroid cancers other than MTC, in which, as expected, there was negligible expression. It is concluded that reduced expression of TSHr implies decreased responsiveness to TSH manipulation and is therefore a clinically important prognostic indicator in thyroid cancers. Copyright © 1999 John Wiley & Sons, Ltd.     

Alpha-methylacyl-CoA racemase: a multi-institutional study of a new prostate cancer marker

AIM: To test whether alpha-methylacyl-CoA racemase (AMACR) is a sensitive and specific marker of prostate cancer. METHODS AND RESULTS: The expression levels of AMACR mRNA were measured by real-time polymerase chain reaction. A total of 807 prostatic specimens were further examined by immunohistochemistry specific for AMACR. Quantitative immunostaining analyses were carried out by using the ChromaVision Automated Cellular Imaging System and the Ariol SL-50 Imaging System, respectively. AMACR mRNA levels measured in prostatic adenocarcinoma were 55 times higher than those in benign prostate tissue. Of 454 cases of prostatic adenocarcinoma, 441 were positive for AMACR, while 254 of 277 cases of benign prostate were negative for AMACR. The sensitivity and specificity of AMACR immunodetection of prostatic adenocarcinomas were 97% and 92%, respectively. Both positive and negative predictive values were 95%. By automatic imaging analyses, the AMACR immunostaining intensity and percentage in prostatic adenocarcinomas were also significantly higher than those in benign prostatic tissue (105.9 versus 16.1 for intensity, 45.7% versus 0.02% and 35.03% versus 4.64% for percentage, respectively). CONCLUSIONS: We have demonstrated the promising features of AMACR as a biomarker for prostate cancer in this large series and the potential to develop automated quantitative diagnostic tests.     

The new molecular markers DDIT3, STT3A, ARG2 and FAM129A are not useful in diagnosing thyroid follicular tumors

Preoperative characterization of thyroid follicular lesions is challenging. Fine-needle aspiration specimens cannot differentiate follicular carcinomas from benign follicular neoplasias. Recently, promising markers have been detected using modern molecular techniques. We conducted a retrospective study to confirm the usefulness of immunohistochemical staining for the protein markers, DDIT3, STT3A (ITM1), ARG2 and FAM129A (C1orf24) in separating benign and malignant thyroid follicular lesions. Formalin-fixed, paraffin-embedded thyroid tissue from 30 in-house cases (15 follicular carcinomas and 15 follicular adenomas), as well as 8 follicular carcinomas and 21 follicular adenomas on tissue microarray slides were stained immunohistochemically for DDIT3, STT3A, ARG2 and FAM129A expression. Control tissue consisted of thyroid parenchyma adjacent to the tumors and 11 separate cases of normal thyroid parenchyma. All in-house cases of follicular adenomas, follicular carcinomas and adjacent normal thyroid tissue showed positive immunostaining with anti-DDIT3 and anti-STT3A. Anti-ARG2 and anti-FAM129A polyclonal antibodies showed positive staining in 20 and 60% of in-house follicular adenomas, and 40 and 87% of in-house follicular carcinomas, respectively. Monoclonal anti-FAM129A demonstrated positive staining in 13 and 33% of in-house follicular adenomas and follicular carcinomas, respectively. Polyclonal anti-DDIT3, -STT3A and -FAM129A antibodies showed positive staining in all tissue microarray slides of follicular carcinoma and in 76, 85 and 81% of the follicular adenomas, respectively. Monoclonal anti-STT3A stained 81% of the follicular adenoma cores. Anti-ARG2 stained positive in 13% of follicular carcinomas and 10% of follicular adenomas on the tissue microarray slides. In conclusion, DDIT3, STT3A, ARG2 and FAM129A immunohistochemistry does not appear to be useful in the diagnosis of thyroid follicular neoplasias, as they do not reliably distinguish follicular thyroid carcinoma from follicular thyroid adenoma.     

Comparison of annexin II, p63 and alpha-methylacyl-CoA racemase immunoreactivity in prostatic tissue: a tissue microarray study

BACKGROUND: Current ancillary markers for diagnosis in prostate biopsies include p63 and alpha-methylacyl-CoA racemase (AMACR). Annexin II (ANXII), a calcium and phospholipid binding protein, is lost in prostate cancer. AIMS: To investigate ANXII expression in order to assess its utility as a novel diagnostic marker in comparison to p63 and AMACR. METHODS: Using immunohistochemistry on six tissue microarrays, ANXII, p63, and AMACR expression was analysed from 210 radical prostatectomy cases. Staining was evaluated in benign and atrophic glands, high-grade prostatic intraepithelial neoplasia (HGPIN), and prostatic adenocarcinoma. Separate scores were given for ANXII, AMACR and p63 expression. RESULTS: Diffuse cytoplasmic expression of ANXII correlated with p63 reactivity in basal cells. Benign glands were positive for ANXII in 286/292 cores (98%) and negative for AMACR in all 292 cores. HGPIN showed heterogeneous expression of AMACR and ANXII. A significantly larger proportion of HGPIN glands were correctly identified as ANXII negative than as positive for AMACR. ANXII loss in prostate cancer was found in 282/320 cores (88%) and correlated with positive AMACR expression (272/320 cores, 85%), which was not statistically significant. There was no statistically significant correlation between ANXII scores and the clinical parameters examined. CONCLUSIONS: Immunohistochemical staining for ANXII is a consistent and reliable marker of prostatic neoplasia. The findings of this study suggest the potential utility of ANXII as a diagnostic aid in prostate cancer histopathology.     

Alpha-methyl CoA racemase expression in renal cell carcinomas

Alpha-methyl CoA racemase (AMACR), a new molecular marker for prostate cancer, has been recently reported to be one of the most highly expressed genes in papillary renal cell carcinomas (RCCs). We tested the diagnostic usefulness of AMACR antibody in a series of 110 renal tumors: 53 papillary RCCs (33 type 1, 20 type 2); 25 conventional RCCs; 6 chromophobe RCCs; 9 oncocytomas; 5 mucinous tubular and spindle tumors; 2 urothelial carcinomas; 7 angiomyolipomas; and 2 Bellini carcinomas. Immunohistochemical staining was performed on formalin-fixed, paraffin-embedded tissue sections, with a primary prediluted rabbit monoclonal anti-AMACR antibody. Both type 1 and type 2 papillary RCCs exhibited cytoplasmic immunoreactivity for AMACR, with diffuse strong granular staining in 96.4% (53/55) of tumors, without correlation with type or nuclear grade. The 5 mucinous, tubular, and spindle cell carcinomas strongly expressed AMACR, and only 5 of 25 clear cell RCCs and 1 of 9 oncocytomas were focally reactive. The remaining 6 chromophobe RCCs, 5 urothelial carcinomas, and Bellini duct carcinomas showed no immunoreactivity for AMACR. Because high expression of AMACR is found in papillary RCCs (type 1 and 2) and in mucinous, tubular, and spindle cell carcinomas of the kidney, immunostaining for AMACR should be used in conjunction with other markers when histological typing of a renal tumor is difficult.     

CD57 (leu-7) Expression is helpful in diagnosis of the follicular variant of papillary thyroid carcinoma

 CD57 (HNK-1) is a oligosaccharide antigen that is expressed by cells of several lineages. It is present on multipotential neuroepithelial cells during embryogenesis, and tumours of epithelial, neuroectodermal and nerve sheath origin also express CD57. Its role in the diagnosis of thyroid tumours is controversial. We have studied CD57 expression by immunohistochemistry to determine its utility in the classification of thyroid follicular lesions. Study material included 114 normal thyroid sections, 77 benign thyroid lesions (29 colloid nodules, 22 follicular adenomas, 20 cases of Hashimoto’s thyroiditis and 6 of Grave’s disease) and 83 thyroid carcinomas, including 31 follicular variants of papillary carcinoma. We observed CD57 positivity in 95% of thyroid carcinomas, 27% of follicular adenomas and 10% of colloid nodules. It was not expressed in the normal thyroid. CD57 expression in thyroid carcinomas was significantly different from that in normal and benign thyroid lesions (P < 0.0001). The follicular variant of papillary thyroid carcinoma also showed significantly higher CD57 expression than colloid nodules (P < 0.0009) or follicular adenomas (P < 0.0009). No significant difference was seen between colloid nodules and follicular adenomas. We conclude that CD57 immunohistochemistry is valuable in the classification of thyroid follicular lesions into benign and malignant groups and is also helpful in the diagnosis of the follicular variant of papillary thyroid carcinoma. Received: 26 August 1997 / Accepted: 14 October 1997     

CD98 expression is decreased in papillary carcinoma of the thyroid and Hashimoto’s thyroiditis

Aims: CD98 is a component of the large neutral amino acid transporter (LAT), which is a cell surface amino acid transporter. CD98 also binds to and activates β₁‐integrin, promoting anchorage‐independent growth. CD98 expression is increased in a variety of carcinomas but its distribution in the normal and neoplastic thyroid gland has not been reported. The aim was to examine the immunohistochemical expression of CD98 in normal and diseased thyroid tissue. Methods and results: One hundred and forty thyroid cases were selected from the archives of the Department of Pathology, including normal controls, neoplasms (follicular adenoma, follicular carcinoma and papillary carcinoma) and non‐neoplastic conditions (multinodular goitre, Graves’ disease and Hashimoto’s thyroiditis). Immunohistochemistry for CD98 was performed and each case was scored for proportion of cells and intensity of immunoreactivity. In normal thyroid, there was moderately strong expression of CD98 in the lateral cell membranes of follicular cells. A similar pattern of expression was seen in follicular adenoma, minimally invasive follicular carcinoma, multinodular goitre and Graves’ disease. In most cases of papillary carcinoma and in the inflamed areas of Hashimoto’s thyroiditis, expression of CD98 was decreased. Conclusions: CD98 expression is down‐regulated in thyroid papillary carcinoma; this may relate to the better prognosis associated with many of these tumours.     

Intermediate-filament expression in thyroid gland carcinomas

Summary Paraffin-embedded specimens of 200 primary thyroid carcinomas were examined immunohistologically for the expression of intermediate-filament (IF) protein of the cytokeratin, vimentin and neurofilament type. In 36 cases, snap-frozen tissue was available, and double label immunofluorescence microscopy was performed in 23 of them.Cytokeratin reactivity was found in all cells of all follicular, papillary and medullary carcinoma cases examined. Using a monoclonal vimentin antibody, positive staining was found in many, though not all cells of the papillary tumours and in approximately 50% of the follicular and the medullary carcinomas. Among anaplastic carcinomas, some tumours were positive for cytokeratins, with or without coexpression of vimentin. Neurofilaments could only be demonstrated in approximately 13% of medullary tumours which in general also exhibited vimentin positivity.The differences of IF expression in follicle and C-cell thyroid carcinomas and the broad variation of cytokeratin and vimentin immunoreactivity among anaplastic tumours of this organ is discussed in relation to the possible intrinsic heterogeneity of these tumours and the diagnostic value of these marker.Dedicated to Prof. Dr. G. Seifert on the occasion of his 65th birthday     

S100A9 expression is significantly linked to dedifferentiation of thyroid carcinoma

S100A9, a calcium-binding protein, is associated with myeloid cell differentiation and is expressed in some adenocarcinomas as well as in squamous epithelia and squamous cell carcinoma. In this study, we immunohistochemically investigated S100A9 expression in thyroid neoplasms. S100A9 was absent in normal follicles, follicular adenoma, and follicular and papillary carcinomas with conventional growth structures. In lesions showing a solid, trabecular, or scirrhous growth pattern, S100A9 immunoreacitivity was occasionally observed. One (5.9%) of the 17 follicular carcinomas and three (7.8%) of the 38 papillary carcinomas were regarded as positive for S100A9, but the positive cell areas always accounted for 5% or less. However, S100A9 was positive in all 19 undifferentiated carcinomas examined. Among them, the positive cell area was greater than 5% in 16 (84.2%), and greater than 25% in six (31.6%) cases. It is therefore suggested that S100A4 protein plays an important role in thyroid carcinoma dedifferentiation, and can be considered a novel characteristic of undifferentiated carcinoma.     

Prognostic evaluation of metallothionein expression in human colorectal neoplasms

AIM: To investigate the role of metallothionein in colorectal tumours and the possible relation with other factors associated with tumour progression: expression of cathepsin D (CD), CD44, p53, Rb, bcl-2, c-erbB-2, epidermal growth factor receptor (EGFR), proliferation indices (Ki-67, proliferating cell nuclear antigen (PCNA)), and conventional clinicopathological variables. METHODS: The immunohistochemical expression of metallothionein was investigated in 23 cases of colorectal adenoma and 94 adenocarcinomas. Metallothionein expression was examined by the avidinbiotin peroxidase immunoperoxidase (ABC) using the monoclonal mouse antibody E9, on formalin fixed, paraffin embedded tissue. RESULTS: Positive metallothionein expression (> 5% of neoplastic cells) was observed in 30.4% of adenomas and 25.5% of adenocarcinomas, while 8.7% of adenomas and 14.9% carcinomas showed focal metallothionein positivity. In contrast, 60.9% of adenomas and 59.6% of carcinomas almost completely lacked metallothionein expression. In the series of adenocarcinomas, metallothionein expression was inversely correlated with CD44 in neoplastic cells (p = 0.01). There was no statistically significant difference of metallothionein expression, or the other variables examined, between adenocarcinomas and adenomas. CONCLUSIONS: Metallothionein expression does not seem to indicate aggressive biological behaviour in colorectal adenocarcinomas, in comparison with the other types of carcinoma. The inverse correlation with CD44 could suggest that the decreased metallothionein expression may contribute to the metastatic spread of the lymph node involvement in colorectal cancer. Metallothionein expression does not seem to represent an independent prognostic marker in colorectal cancer.     

Evaluation of CD43 expression in non-hematopoietic malignancies

ObjectivesCD43 is normally expressed only on the surface of leukocytes, and is considered a sensitive and specific marker for hematologic malignancies. As such, it may have diagnostic utility in confirming hematolymphoid lineage in cases that are negative for CD45. Aberrant CD43 expression has been described in non-hematopoietic tumors, although literature data on this topic is variable and sometimes contradictory. To clarify and expand on existing literature findings, we evaluated CD43 expression by immunohistochemistry (IHC) in a large cohort (307) of non-hematopoietic neoplasms, including poorly differentiated malignancies.Methods17 tissue microarrays and sections from 19 individual cases were stained with CD43 (clone DF-T1) monoclonal antibody. The proportion of positive cells, stain localization (nuclear, cytoplasmic or membranous), and intensity (compared to internal leukocyte controls) were recorded in all cases.ResultsThere were 98/307 (32%) positive cases, that showed focal weak nuclear staining in 1–25% of cells, including 23/25 (92%) pancreatic ductal adenocarcinomas; 31/34 (91%) breast invasive ductal carcinomas; 13/15 (87%) papillary thyroid carcinomas; 3/4 (75%) follicular thyroid carcinomas; 6/15 (40%) renal cell carcinomas; 9/28 (32%) lung adenocarcinomas; 1/13 (8%) lung squamous cell carcinomas (SCCs); 2/8 (25%) prostate adenocarcinomas; 8/62 (13%) colon adenocarcinomas; and 2/21 (10%) neuroendocrine neoplasms. None of the positive cases demonstrated strong, membranous CD43 expression comparable to that seen in background mature lymphocytes or segmented neutrophils. Negative cases included 11 cervical SCCs, 12 cervical adenocarcinomas, 19 urothelial carcinomas, 10 lung small cell carcinomas, 11 sarcomas, and 19 poorly differentiated carcinomas from various tissue sites.ConclusionsIn our cohort, most non-hematopoietic neoplasms are negative for CD43 expression, with a subset showing focal, weak nuclear positivity. This data indicates that uniform and strong membranous staining appears to be specific to hematopoietic neoplasms.     

Value of thrombomodulin immunostaining in the diagnosis of transitional cell carcinoma: a comparative study with carcinoembryonic antigen

Aims: Thrombomodulin (TM) is a surface glycoprotein involved in the regulation of intravascular coagulation that has been reported to be expressed in a variety of tumours. We investigated TM expression in transitional cell carcinoma (TCC) and compared the value of TM immunostaining with that of carcinoembryonic antigen (CEA) for differentiating TCC from other tumours with which it may be confused.  

Methods and results:

Immunostaining was performed on formalin-fixed, paraffin-embedded tissue sections using the avidin–biotin–peroxidase complex method. TM immunoreactivity was observed in 80 of 91 primary (51/58 urinary bladder, 10/12 renal pelvis, 3/3 ureter, 15/15 prostate, 1/3 ovary), and 18 of 20 metastatic TCCs expressed this marker. Only 37 of the 91 primary (23/58 urinary bladder, 4/12 renal pelvis, 1/3 ureter, 9/15 prostate, 0/3 ovary) and six of the 20 metastatic TCCs reacted for CEA. In order to evaluate the practical utility of TM immunostaining in surgical pathology, 30 adenocarcinomas of the prostate, 18 of the bladder, 12 of the colon, and 22 renal cell carcinomas were also stained for these markers. CEA reactivity was obtained in 12 of 30 adenocarcinomas of the prostate, 12 of 18 of the bladder, and 12 of 12 of the colon, but in none of the 22 renal cell carcinomas. Only three of the 18 adenocarcinomas of the bladder showed focal TM reactivity, but no staining for this marker was observed in any of the other types of tumours.  

Conclusions:

TM is a more sensitive marker than CEA for TCC and, because it has a more restricted reactivity with other tumours, TM has more practical value in separating TCCs from adenocarcinomas of the prostate, colon and bladder, and renal cell carcinomas than CEA.     

Nuclear beta catenin as a potential prognostic and diagnostic marker in patients with colorectal cancer from Hong Kong.

AIMS: To study the expression of nuclear beta catenin in patients with colorectal cancer, colorectal adenoma, and colorectal polyps to elucidate its role in carcinogenesis, and its potential for prognosis and diagnosis. METHODS: The expression of nuclear beta catenin was studied by immunohistochemistry using paraffin wax embedded specimens. Sixty specimens each of colorectal carcinoma, colorectal adenoma, colorectal polyp, and normal colorectal specimens were analysed. The potential for prognosis was assessed by correlating nuclear beta catenin expression in 60 and 75 patients with colorectal cancer with lymph node metastasis and survival, respectively. The diagnostic capacity was explored by comparing nuclear beta catenin expression in 60 patients with colorectal cancer with other cytokeratin 20 (CK20) positive adenocarcinomas, namely: 30 colonic mucinous adenocarcinomas, 30 gastric adenocarcinomas, 27 pancreatic adenocarcinomas, and 12 ovarian mucinous adenocarcinomas. RESULTS: Nuclear beta catenin expression was highly associated with progression of colorectal tissue from normal epithelial tissue, polyps, adenomas, to carcinomas (r = 0.875; p < 0.0001). Nineteen patients with colorectal adenoma who subsequently developed colorectal carcinoma had higher nuclear beta catenin expression than those with colorectal adenomas alone (p < 0.0001). Moreover, those patients with colorectal cancer and high nuclear beta catenin expression had a higher incidence of lymph node metastasis (chi(2) = 16.99; p < 0.005) and shorter overall survival (p < 0.0001). Finally, nuclear beta catenin expression in colorectal adenocarcinomas was significantly higher than in other CK20 positive adenocarcinomas. CONCLUSIONS: Nuclear beta catenin expression is a potential prognostic factor in patients with colorectal cancer, and together with CK20, it could be used to identify colorectal carcinoma in the Hong Kong population.     

Expression of a colorectal antigen defined by a new monoclonal antibody, CO-TL1

A murine monoclonal antibody (MoAb CO-TL1, IgG1) has been raised by differential screening of hybridoma supernatants on sections of human large and small intestines, followed by screening on colon adenomas as well as on colorectal carcinomas. In both paraffin sections and cryostat sections, the antibody stained strongly all cell types in adult, neonatal and fetal human colorectal epithelium, that is, the goblet cells, the columnar cells and the endocrine cells. No staining was observed in the remaining parts of the normal gastrointestinal tract and other tissues. As revealed by immuno electron microscopy the epitope was present in the apical and basolateral cell membranes, the Golgi complex, secretory vesicles of goblet and columnar cells, and also in granules of the endocrine cells. The epitope in colorectal tissue sections was resistant to the deglycosylation enzymes neuramidase, diastase and hyaluronidase indicating its proteinaceous nature. This colorectal antigen remained expressed in 100% of colorectal adenomas (n = 39) and 86% (n = 29) of colorectal carcinomas. The expression was reduced in undifferentiated carcinomas. The CO-TL1 antibody detected also most other gastrointestinal adenocarcinomas and a few carcinomas of the ovary, uterus, breast, gallbladder and pancreas. However, it never detected carcinomas derived from the thyroid, lung, liver, bladder, kidney, prostate, testis, serous membranes of body cavities and skin. A wild-type variant protein of > 300 kDa of the colorectal antigen was identified in normal colorectal epithelium. In colorectal tumours, however, two tumour variant forms were found of 160-200 and 115-140 kDa, respectively. Our data indicate that this new MoAb CO-TL1 can be considered as a useful marker, which identifies normal colorectal epithelium and gastrointestinal tumours and especially colorectal tumours with high accuracy and excludes tumours originated from thyroid, lung, liver, bladder, kidney, prostate, testis, mesothelium and skin.     

Differential gene expression profiling of aggressive and nonaggressive follicular carcinomas

The classification of follicular thyroid neoplasms requires surgical resection for histologic evaluation of malignancy. Because variable clinical behavior exists, genomic expression profiling may lead to the identification of novel markers that facilitate better biologic classification. We performed for the first time gene expression analysis on clinically aggressive and nonaggressive follicular carcinomas (FCs) from patients for whom long-term follow-up data were available. We examined matched fresh-frozen tissue from 15 histopathologically diagnosed follicular carcinomas (7 patients with documented distant metastasis and/or death from disease and 8 patients without recurrence). For categorical comparison, we analyzed 4 follicular adenomas (FAs). The biologic control comprised 11 normal thyroid tissue specimens. High-quality RNA was extracted from the tissues, labeled, and hybridized to an Affymetrix (Santa Clara, CA) oligonucleotide microarray (HG-U133A). With the exceptions of 1 follicular adenoma and 1 follicular carcinoma, unsupervised hierarchical cluster analysis revealed 2 distinct groups--one containing normal thyroid tissue and follicular adenomas and another containing follicular carcinomas. We identified 421 genes that were differentially expressed between histologically normal thyroid tissues and all follicular neoplasms (P < 0.01; fold-change >2), 94 genes that distinguished follicular carcinomas from follicular adenomas (including PBP and CKS2), and 4 genes that distinguished aggressive follicular carcinomas from nonaggressive follicular carcinomas (NID2, TM7SF2, TRIM2, and GLTSCR2). Comparative genomic groupings identified differentially expressed genes that may lead to better classification of follicular thyroid neoplasms. Such genes may be used in future prospective validation studies to establish clinically useful and complementary diagnostic markers.