Biomedical subjects

H Höfler

Publications and source records attributed to H Höfler.

At least 19 recordsLinked to original sources

PubMed1999

Intratumoral heterogeneity in breast carcinoma revealed by laser-microdissection and comparative genomic hybridization.

To evaluate the potential cytogenetic heterogeneity in breast carcinoma, several small cell groups (each consisting of 20 to 50 cells) were investigated within paraffin sections. By laser-microdissection, three to seven cell groups were taken per case. The DNA was amplified by degenerate oligonucleotide primed PCR (DOP-PCR), and the samples were analyzed by CGH for chromosomal gains and losses. Two ductal invasive breast carcinomas, one of them with two lymphnode metastases, were investigated. To compare the results from the small samples, CGH was also performed on DNA isolated from the tumorous regions of three to five serial sections (10(7) to 10(6) cells). The aberrations observed in the microdissected tumor samples were multiple and involved up to 14 different chromosomal or subchromosomal regions. The most frequent changes were gains on chromosomes 12q (14/20) and 20q (16/20), and loss on 13q (12/20). Some aberrations have rarely been detected (e.g., loss on 2p, gain on 8q). Comparing chromosomal imbalances in primary tumors and lymph node metastases, more consistent changes were found between the primary tumor and its corresponding metastases than between both primary tumors. The laser-microdissected samples in general showed more chromosomal aberrations than DNA isolated from several tumor sections. Our CGH results were confirmed by fluorescence in situ hybridization (FISH) for the chromosomal regions of centromere 1 and 20, and 20q13. In addition, microsatellite analyses on 31 samples confirmed our CGH findings for selected chromosome regions 2p and 11q. It can be concluded that there is a distinct intratumoral heterogeneity in primary breast tumors as well as in the corresponding lymph node metastases. The combination of microdissection and CGH enabled us to detect cytogenetic aberrations from important clones which are missed when analyzing DNA extracted from large cell numbers.

Breast Neoplasms↗

PubMed1999

Neoadjuvant chemotherapy for patients with locally advanced gastric carcinoma: effect on tumor cell microinvolvement of regional lymph nodes.

BACKGROUND: In a previous study the authors demonstrated, using immunohistochemical methods for epithelial antigens, that the regional lymph nodes of gastric adenocarcinoma contained individual tumor cells or small clusters of these cells (tumor cell microinvolvement [TCM]) in over 90% of cases. In the current study the authors used the same method to investigate a series of gastric adenocarcinoma cases treated with neoadjuvant chemotherapy prior to tumor resection; their aim was to determine the effect of chemotherapy on TCM in regional lymph nodes. METHODS: Resection specimens from 17 patients with adenocarcinoma of the stomach, resected after neoadjuvant treatment and classified by routine histology as ypN0, were included in this study. One section from each of the 622 lymph nodes dissected from these specimens was stained by immunohistochemical methods for cytokeratins and Ber-Ep4. RESULTS: Six patients (35%) and 25 of the 622 lymph nodes (4.0%) had TCM, compared with 93% of patients and 21.8% of lymph nodes in the previous study of patients treated with surgery alone. The lymph node response to chemotherapy correlated with the pathologic response of the primary tumor. Specifically, none of 5 patients with a complete or major pathologic response versus 6 of 12 (50%) patients with minor, partial, or no response had lymph node microinvolvement. CONCLUSIONS: In comparison to our previous study, this study indicates that chemotherapy has a marked effect on tumor cells in regional lymph nodes and that the extent of this effect can be correlated with the degree of pathologic response of the primary tumor to chemotherapy.

Adenocarcinoma↗

PubMed1999

Mapping of a cadherin gene cluster to a region of chromosome 5 subject to frequent allelic loss in carcinoma.

Cadherin adhesion molecules define cellular interactions during embryogenesis and morphogenesis, while later in life they are responsible for maintaining tissue integrity. Mutation and loss of expression of cadherins have been implicated in the progression of some malignant tumors, suggesting that cadherins may also act as tumor/metastasis suppressor genes. To determine the extent to which cadherin loci could be affected by allelic losses, we used radiation hybrid mapping to define the chromosomal position of five cadherin genes. A cadherin gene cluster consisting of three genes was identified on the short arm of chromosome 5. This region of the genome is subjected to frequent allelic loss in malignant disease.

Alleles↗

PubMed1999

Cadherin-11 is highly expressed in rhabdomyosarcomas and during differentiation of myoblasts in vitro.

Rhabdomyosarcomas bear a morphological and genetic resemblance to developing skeletal muscle. Apart from myogenic marker genes (bHLH factors, myosin, actin), cell adhesion molecules such as N-cadherin and N-CAM have been reported to be expressed both in rhabdomyosarcomas and during myogenesis. The present study demonstrates the expression of another cadherin, cadherin-11, in rhabdomyosarcomas and during differentiation of myoblasts in vitro: cadherin-11, a predominantly mesenchymal cell adhesion molecule, is highly expressed in embryonal rhabdomyosarcomas and alveolar rhabdomyosarcomas, which do not bear the Pax-3-FKHR fusion previously described. Cadherin-11 is down-regulated in normal skeletal muscle and after myotube formation in vitro. The results of this study suggest that cadherin-11 might be involved in myogenesis and that rhabdomyosarcomas may re-express or fail to down-regulate cadherin-11. Since alveolar rhabdomyosarcomas bearing the t(2;13) translocation do not express cadherin-11, it is postulated that Pax-3 and cadherin-11 might be linked and involved in the same myogenic pathway.

Animals↗

PubMed1999

Functional loss of E-cadherin and cadherin-11 alleles on chromosome 16q22 in colonic cancer.

Proteins of the cadherin family regulate cellular adhesion and motility and are believed to act as tumour suppressors. Previous studies have identified frequent mutation and allelic inactivation of the E-cadherin (cadherin-1) locus in diffuse gastric cancer. At least two other cadherin genes, P-cadherin (cadherin-3) and OB-cadherin (cadherin-11), have been mapped close to the E-cadherin gene on chromosome 16q22. As this region of the genome is frequently deleted in malignancy, multiple cadherin loci may be affected by losses of chromosome 16q22. The expression of mRNA transcripts from polymorphic alleles of the E-cadherin and cadherin-11 genes was examined in 30 cases of colonic, gastric, and renal carcinoma. In gastric cancer, loss of expression of one allele was restricted to the E-cadherin locus, whilst in renal carcinoma neither locus was affected. In colonic cancers, loss of expression of one E-cadherin allele was detected in 5 of 22 cases, whilst loss of a cadherin-11 allele was seen in 5 of 23 cases. This functional loss of cadherin gene expression may be due to gene deletion, inactivation or recombination. As no evidence of cadherin gene mutation was observed in the remaining transcripts, we can conclude that these two genes are only indirectly involved in the pathogenesis of colorectal cancer.

Blotting, Northern↗

PubMed1999

Identification of eleven novel tumor-associated E-cadherin mutations. Mutations in brief no. 215. Online.

The cell adhesion molecule E-cadherin (CDH1; MIM# 192090) has been implicated in numerous cellular functions, ranging from controlling morphogenesis to suppressing tumor invasion. We describe 11 previously unreported somatic E-cadherin mutations in two subgroups of gastric and breast cancer showing markedly reduced homophilic cell-to-cell interactions. Using reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing of the entire coding region 5 mutations were detected in diffuse-type gastric cancer specimens. The sequence alterations include 3 missense mutations affecting exons 3, 10, and 12. Furthermore, two in-frame deletions were identified removing 63 and 9 base pairs from exon 4 and 5, respectively. In invasive Lobular breast cancer 6 E-cadherin mutations were detected after RT-PCR amplification and direct sequencing or using single strand conformation polymorphism (SSCP) analysis followed by sequencing. In addition to two nonsense mutations affecting exon 2, four out-of-frame deletions removing 115 base pairs (entire exon 2), 224 base pairs (entire exon 3), 8 base pairs from exon 12 or 1 base pair from exon 13 were seen. Our report confirms the general principle that in diffuse-type gastric cancer E-cadherin mutations result in structurally altered proteins with possible reduced adhesive functions whereas in invasive lobular breast carcinomas complete loss-of-function mutations are characteristic.

Breast Neoplasms↗

PubMed1999

Loss of immunohistochemical E-cadherin expression in colon cancer is not due to structural gene alterations.

E-cadherin, a transmembrane cell adhesion molecule, has been observed to have an altered pattern of immunoreactivity in several types of carcinomas. In lobular breast cancer, loss of immunoreactivity has been shown to be due either to out-of-frame deletions or to nonsense mutations of the E-cadherin gene. We analysed 29 cases of completely resected colon carcinoma with immunohistochemistry using the HEC-D1 antibody. Normal protein expression similar to that in the adjacent nonmalignant mucosa was seen in 6 cases, whereas 23 tumours had reduced or absent E-cadherin expression. In the 8 cases with no expression of E-cadherin revealed by immunohistochemistry, the entire E-cadherin cDNA sequence was analysed. In these cases, sequence analysis failed to reveal any cDNA mutations despite the negative immunohistochemistry. Possible explanations for this discrepancy include regulatory defects in the E-cadherin promoter, abnormalities at the translation or protein processing levels and mutations in other parts of the gene that were not investigated by the cDNA analysis (e.g. intronic sequences), which could play a role in causing abnormal processing of the E-cadherin protein.

Adult↗

PubMed1999

Invasion marker PAI-1 remains a strong prognostic factor after long-term follow-up both for primary breast cancer and following first relapse.

In 1991, our group was the first to report the prognostic strength of plasminogen activator inhibitor type 1 (PAI-1) in primary breast cancer. The prognostic impact of invasion markers PAI-1 and urokinase-type plasminogen activator (uPA) on disease-free survival (DFS) and overall survival (OS) in breast cancer has since been independently confirmed. We now report on the prognostic impact of PAI-1 and uPA after long-term median follow-up of 77 months for our cohort (n = 316). Levels of uPA, PAI-1, and cathepsin D were determined in tumor tissue extracts by immunoenzymatic methods. S-phase fraction (SPF) was measured flowcytometrically in paraffin sections. Using log-rank statistics, optimized cutoffs were found for PAI-1 (14 ng/mg), uPA (3 ng/mg), cathepsin D (41 pmol/mg), and SPF (6%). In all patients, various factors (PAI-1, uPA, nodal status, SPF, cathepsin D, grading, tumor size, hormone receptor status) showed significant univariate impact on DFS. In Cox analysis, only nodal status (p < 0.001, RR: 3.1) and PAI-1 (p < 0.001, RR: 2.7) remained significant. In node-negative patients (n = 147), PAI-1, uPA, and SPF had significant univariate impact on DFS, whereas in Cox analysis, only PAI-1 was significant. PAI-1 was also significant for DFS within subgroups defined by established factors. In CART analysis, uPA enhanced the prognostic value of PAT-1 and nodal status for determination of a very-low-risk subgroup. For OS, only lymph node status and PAI-1 were significant in multivariate analysis. PAI-1 levels in the primary tumor were also a significant prognostic marker for survival after first relapse in both univariate and multivariate analysis.

Adult↗

PubMed1999

Prognostic significance of urokinase (uPA) and its inhibitor PAI-1 for survival in advanced ovarian carcinoma stage FIGO IIIc.

Strong evidence has accumulated on the prognostic value of tumour-associated proteolytic factors in patients afflicted with solid malignant tumours, including advanced ovarian cancer. We evaluated the prognostic impact of the protease urokinase plasminogen activator (uPA) and its inhibitor PAI-1 on overall survival in patients with advanced ovarian cancer stage FIGO IIIc in order to select patients at risk. uPA and PAI-1 antigen were determined by ELISA in primary tumour tissue extracts of 86 ovarian cancer patients FIGO stage IIIc enrolled in a prospective study. Univariate and multivariate analyses were performed using the Cox proportional hazard model. The time-varying coefficient model of Gray was used to assess the time-dependent strength of prognostic factors tumour mass, uPA and PAI-1 on overall survival. In all patients, uPA and PAI-1 (optimized cut-offs of 2.0 and 27.5 ng mg(-1) protein respectively), in addition to the traditional prognostic parameters of residual tumour mass, nodal status, grading and ascites volume, were of prognostic significance in univariate analysis for overall survival. Even in patients with residual tumour mass (n = 43), the statistically independent prognostic impact of PAI-1 persisted, allowing further discrimination between low- and high-risk patients. In multivariate analysis, residual tumour mass (P < 0.001, relative risk (RR) 4.5), PAI-1 (P < 0.001; RR 3.1) and nodal status (P = 0.022, RR 2.6) turned out to be strong, statistically independent prognostic parameters. Evaluation of the time-dependent prognostic impact of residual tumour mass and PAI-1 on overall survival (n = 86, 50 months) revealed that the prognostic power of these factors increased with time. In patients with advanced ovarian cancer, both residual tumour mass and PAI-1 are statistically independent strong prognostic factors. Even within patient subgroups with or without residual tumour mass, PAI-1 allowed selection of patients at risk who might benefit from individualized therapy protocols.

Adult↗

PubMed1999

Risk-group discrimination in node-negative breast cancer using invasion and proliferation markers: 6-year median follow-up.

Factors reflecting two major aspects of tumour biology, invasion (urokinase-type plasminogen activator (uPA), plasminogen activator inhibiter (PAI-1), cathepsin D) and proliferation (S-phase fraction (SPF), Ki-67, p53, HER-2/neu), were assessed in 125 node-negative breast cancer patients without adjuvant systemic therapy. Median follow-up time was 76 months. Antigen levels of uPA, PAI-1 and cathepsin D were immunoenzymatically determined in tumour tissue extracts. SPF and ploidy were determined flow-cytometrically, Ki"'-67, p53, and HER-2/neu immunohistochemically in adjacent paraffin sections. Their prognostic impact on disease-free (DFS) and overall survival (OS) was compared to that of traditional factors (tumour size, grading, hormone receptor status). Univariate analysis determined PAI-1 (P < 0.001), uPA (P = 0.008), cathepsin D (P = 0.004) and SPF (P = 0.023) as significant for DFS. All other factors failed to be of significant prognostic value. In a Cox model, only PAI-1 was significant for DFS (P < 0.001, relative risk (RR) 6.2). In CART analysis for DFS, the combination of PAI-1 and uPA gave the best risk group discrimination. For OS, PAI-1, cathepsin D, tumour size and ploidy were statistically significant in univariate, but PAI-1 was the only independently significant factor in Cox analysis (P < 0.001, RR 8.9). In particular, this analysis shows that PAI-1 is still a strong and independent prognostic factor in node-negative breast cancer after extended 6-year median follow-up.

Adult↗

PubMed1999

The molecular pathology of Barrett's esophagus.

The incidence of adenocarcinoma of the distal esophagus is rapidly increasing in the Western world. The histopathological sequence of (Barrett's) metaplasia, which develops as a consequence of chronic reflux, to dysplasia and then to carcinoma is well established for these tumors. In Barrett's esophagus a variety of molecular changes have been characterized and correlated with tumor initiation and progression. Among the early changes in premalignant stages of metaplasia are alterations of the transcripts of FHIT, a presumptive tumor suppressor gene which spans the common fragile site FRA3B. Mutations of p53 seem to accumulate mainly in the transition from low to high grade dysplasia. Inactivation of other tumor suppressor genes by mutation (APC, p16) or hypermethylation (p16) as well as amplification of oncogenes such as cerbB2 are relatively late events in the development of adenocarcinoma. Among the phenotypic changes in Barrett's esophagus are an expansion of the Ki67 proliferation compartment which correlates with the degree of dysplasia. Moreover, accumulation of rab11 molecules which are involved in membrane trafficking has been reported to be specific for the loss of polarity seen in low grade dysplasia. Reduced expression of the cadherin/catenin complex as well as increased expression of various proteases develop chiefly in invasive carcinomas. Despite the progress that has been made in the identification of molecular markers in Barrett's carcinoma, to date the histopathological diagnosis of high grade dysplasia in endoscopic biopsies remains the best predictor of invasive cancer. Immunohistochemistry applying a panel of antibodies including p53, Mib-1 or rab11 can be helpful to diagnose regenerative metaplastic epithelium or low and high grade dysplasia.

Barrett Esophagus↗

PubMed1999

Suppression of T1-receptor expression by antisense RNA abrogates differentiation of osteogenic osteosarcoma cells.

Soluble and membrane-associated variants of the orphan T1-receptor, a homolog of interleukin-1 receptor type I, are expressed in proliferating preosteoblasts in differentiating bone. Recent evidence reveals that T1-receptor synthesis is retained in osteogenic osteosarcoma cells. Here we report that the suppression of T1-receptor expression by mouse osteosarcoma cells using a T1 -antisense expression vector results in the abrogation of the osteogenic potential of the tumor cells. T1-antisense-expressing tumor cells formed anaplastic tumors in vivo and failed to express the osteoblast-specific genes collagen type 1, alkaline phosphatase, and osteocalcin when cultured in a 3-dimensional collagen type I matrix in vitro. Suppression of T1-receptor synthesis did not affect the expression of the essential bone cell-specific transcription factor AML3/CBFA1 in the osteosarcoma cells. These data provide the first evidence that T1-receptor plays a key role in osteogenic differentiation.

Animals↗

PubMed1999

Loss of heterozygosity in 11q13-14 regions in gastric neuroendocrine tumors not associated with multiple endocrine neoplasia type 1 syndrome.

Loss of heterozygosity (LOH) at the MEN1 gene locus at 11q13 is commonly found in type II gastric carcinoid tumors, which are associated with multiple endocrine neoplasia type 1 (MEN-1). In contrast, information is scanty or absent for other types of gastric neuroendocrine tumors, represented by type I carcinoids (associated with chronic atrophic gastritis), type III (sporadic) carcinoids, and neuroendocrine carcinomas. Moreover, LOH analysis of the allelic region distal to the MEN1 gene, which is postulated to contain an additional tumor suppressor gene effective in MEN-1-associated and sporadic endocrine tumors, has never been performed. To clarify these issues, DNA extracted from archival tissue from 25 type I carcinoids, 4 type III carcinoids, and 2 neuroendocrine carcinomas was amplified by PCR, using primers for six polymorphic markers located on chromosome 11q13 (PYGM, D11S4946, and D11S913) and 11q14 (D11S916, D11S901, and D11S1365), for analysis of LOH. Allelic losses in the 11q13-14 region with at least two polymorphic markers were found in 12 of 25 (48%) type I carcinoids. When LOH was found in the 11q13 region, it was large and continuous and extended to the most telomeric marker investigated. In one tumor, retention of heterozygosity for markers in the MEN1 region and LOH for distal markers were observed. No LOH was found in three of four type III carcinoids. Large deletions in both the 11q13 and 11q14 regions were observed in both neuroendocrine carcinomas investigated. In conclusion, LOH in the 11q13-14 regions is frequently found in type I carcinoids and neuroendocrine carcinomas of the stomach, suggesting the involvement of the MEN1 gene and/or a more telomeric tumor suppressor gene in the pathogenesis of these non-MEN-1-associated neuroendocrine tumors. The low rate of LOH at 11q13-14 suggests the predominance of different genetic mechanisms in type III carcinoids, which also differ from other types of gastric carcinoids in the lack of a promoter role for gastrin.

Carcinoid Tumor↗

PubMed1998

Distinct cytogenetic alterations in squamous intraepithelial lesions of the cervix revealed by laser-assisted microdissection and comparative genomic hybridization.

BACKGROUND: It has been established that comparative genomic hybridization (CGH) on Papanicolaou-stained cervical smears can be used to identify chromosomal imbalances. METHODS: In this study, the authors identified normal and dysplastic squamous epithelial cells cytologically, eliminated surrounding bacteria or leukocytes by a ultraviolet laser microbeam under microscopic control, and scraped out the cell groups of interest by a microdissection system. In 3 cases of squamous intraepithelial lesions (SIL), a total of 9 samples of dysplastic (n = 6) and nontumorous cells (n = 3) were investigated, each of them consisting of 3-40 cells. The DNA was amplified by degenerate oligonucleotide primed PCR (DOP-PCR) and used for CGH. RESULTS: Analyses of all nontumorous cell groups resulted in fluorescence ratio profiles that showed no deviation from the normal range, confirming that no methodologic artefacts have been produced. The CGH profiles from dysplastic cells, however, showed various chromosomal imbalances affecting six to nine different chromosomes. The most frequent gains in DNA were observed on chromosomes 1p, 2q, 4, and 5, whereas losses were found on chromosomes 6q and 13q. CONCLUSIONS: The results of this study demonstrate the feasibility and reliability of CGH on microdissected cell samples of routinely processed cervical smears. To the authors' knowledge, this is the first study reporting the use of CGH on cervical routine smears. This approach offers the opportunity to investigate sequence copy number changes in small, morphologically well-defined groups of dysplastic cells. It may, therefore, serve as a cytogenetic screening test for identifying chromosomal aberrations in precancerous lesions that are associated with a high risk for progression to invasive cancer.

Chromosome Aberrations↗

PubMed1998

Micrometastasis and tumor cell microinvolvement of lymph nodes from esophageal squamous cell carcinoma: frequency, associated tumor characteristics, and impact on prognosis.

BACKGROUND: The purpose of this study was to investigate micrometastasis (MM) and tumor cell microinvolvement (TCM) in the regional lymph nodes of patients with esophageal squamous cell carcinoma (SCC). METHODS: MM was defined as individual tumor cells or tumor cell clusters <0.5 mm in greatest dimension with a surrounding stromal reaction. TCM was defined as individual tumor cells or tumor cell clusters without a surrounding stromal reaction. One thousand nine hundred and fifty-four lymph nodes were dissected from 69 complete (R0) resection specimens of TNM classified pT1-3, pN0 or pN1, and M0 esophageal SCC. These lymph nodes were examined immunohistochemically using the monoclonal antibody cocktail AE1/AE3 for cytokeratins. The primary tumors were immunostained with an anti-E-cadherin monoclonal antibody. RESULTS: MM +/- TCM was found in 13 cases (31.7%) and TCM alone in 2 cases (4.9%) of the 41 pN0 cases. The pN0 patients with MM (but not TCM) had the same shorter survival as the original pN1 cases (P < 0.05). Of the 69 primary tumors, 49 (71.0%) had reduced or negative E-cadherin expression that showed a correlation with the occurrence of lymph node metastases (original pN1), MM, and TCM, but not prognosis. CONCLUSIONS: The results of the current study show that, in SCC of the esophagus, MM, but not TCM, in the regional lymph nodes is prognostically equivalent to metastasis and should be examined by immunohistochemistry to classify these cases correctly as pN1.

Adult↗

PubMed1998

Mutations of the human E-cadherin (CDH1) gene.

The cell-cell adhesion molecule E-cadherin is well known to act as a strong invasion suppressor in experimental tumor cell systems. Frequent inactivating mutations have been identified for the E-cadherin gene (CDH1) in diffuse gastric cancers and lobular breast cancers. To date, 69 somatic mutations have been reported comprising, in addition to few missense mutations, mainly splice site mutations and truncation mutations caused by insertions, deletions, and nonsense mutations. Interestingly, there is a major difference in mutation type between diffuse gastric and infiltrative lobular breast cancers. In diffuse gastric tumors, the predominant defects are exon skippings, which cause in-frame deletions. By contrast, most mutations found in infiltrating lobular breast cancers are out-of-frame mutations, which are predicted to yield secreted truncated E-cadherin fragments. In most cases, these mutations do occur in combination with loss of heterozygosity (LOH) of the wild-type allele. Inactivating germline mutations of E-cadherin were recently reported for families with early-onset diffuse gastric cancer. Also, at the early stages of sporadic lobular breast and diffuse gastric cancers, E-cadherin mutations were detected, suggesting loss of growth control by such mutations and defining E-cadherin as a true tumor suppressor for these particular tumor types.

Breast Neoplasms↗

PubMed1998

Genetic heterogeneity in a prostatic carcinoma and associated prostatic intraepithelial neoplasia as demonstrated by combined use of laser-microdissection, degenerate oligonucleotide primed PCR and comparative genomic hybridization.

We combined laser-assisted microdissection from H&E-stained paraffin sections, degenerated oligonucleotide-primed polymerase chain reaction (DOP-PCR), and comparative genomic hybridization (CGH) to analyse chromosomal imbalances in small tumour areas consisting of 50-100 cells. This approach was used to investigate intratumour genetic heterogeneity in a case of metastatic prostatic adenocarcinoma and chromosomal changes in areas of prostatic intraepithelial neoplasia (PIN) adjacent to the invasive tumour. In four microdissected invasive tumour areas with different histological patterns (acinar, cribriform, papillary and solid) marked intratumour heterogeneity was found by CGH. Recurrent chromosomal imbalances detected in at least two microdissected tumour areas were gains on 1p32-->p36, 2p22, 3q21, 7, 8q21-->q24, 11q12-->q13, 16p12-->p13, 17, 19 and loss on 16q23. Additional chromosomal changes were found in only one of the microdissected areas (gains on 16q21-->q23, 20q22 and losses on 8p21-->p23, 12p11-->q12, 12q21-->q26, 13q21-->q34, 16q12, and 18q22). In PIN, gains on chromosomes 8q21-->q24 and 17 were found in both samples investigated (low and high grade PIN), while gains on chromosomes 7, 11q, 12q, 16p, and 20q and losses on 2p, 8p21-->p23, 12q were found only in one PIN area. Controls to ensure reliable CGH results consisted in CGH analyses of (i) approximately 80 microdissected normal epithelial cells, which showed no aberrations after DOP-PCR and (ii) larger cell numbers (approximately 10(5) or 10(7) cells) of the primary tumour investigated without DOP-PCR and partially displaying the chromosomal imbalances (gain on 16p12-->p13, losses on 2p25, 8p21-->p23, 12p11-->p12, 12q21-->q26, 18q22) found in the small microdissected areas. Microsatellite and FISH analyses further confirmed our CGH results from microdissected cells. The combined approach of laser-assisted microdissection, DOP-PCR and CGH is suitable to identify early genetic changes in PIN and chromosomal imbalances associated with the particular histological patterns of invasive prostatic adenocarcinoma.

Adenocarcinoma↗

PubMed1998

Comparison of CD44 expression in early colorectal carcinomas of the de novo and ex adenoma types.

Small colorectal carcinomas without morphological evidence of origin from an adenoma have been called "de novo" carcinomas. As changes in the expression of the adhesion molecule CD44 and its variants have been described along the adenoma-carcinoma sequence in colorectal carcinoma, we compared patterns of CD44 expression in early de novo and ex-adenoma colorectal carcinomas by staining specimens from a group of early (pT1) colorectal carcinomas by immunohistochemistry for CD44 (standard and variant forms v3, v5, v6, v7, v7/8, v10). We evaluated carcinoma, adenoma (ex-adenoma cases), transitional mucosal areas and apparently nonneoplastic mucosa peripheral to the lesions (when present). A marked increase was seen in numbers and intensity of standard and variant forms of CD44 in carcinomatous areas compared with nonneoplastic mucosa in both groups, with no significant difference between the groups. However, adenoma areas of the ex-adenoma cases and the transitional mucosa of the de novo carcinomas had nearly identical staining patterns. Together with data from other molecular studies, this may be interpreted as evidence for an adenoma-type precursor lesion in so-called de novo colorectal carcinomas.

Adenoma↗