Expression of the neuroectodermal intermediate filament nestin in human melanomas

Nestin is a newly identified intermediate filament expressed in proliferating neuronal progenitor cells, but not in the adult brain. Nestin expression reappears in many tumors of the central nervous system and has in human glioblastomas been associated with a high degree of malignancy. Because melanocytes are of neuroectodermal origin, we studied nestin expression in benign and malignant cells of the melanocytic lineage using Northern blot and immunohistochemical analyses. Nestin mRNA was detected in 24 of 34 metastatic melanomas and in 1 of 4 benign nevi, whereas the protein was expressed in 10 of 15 primary melanomas, in 29 of 34 metastatic tumors, and in 3 of 4 nevi. Neither normal melanocytes nor any of 4 basal cell carcinomas showed detectable levels of the protein. The high fraction of melanocytic tumors which express nestin, particularly the metastatic melanomas, suggests that nestin may be a useful marker for such malignancies. Furthermore, although no significant correlation between nestin expression and tumor malignancy was observed, the protein was most abundantly expressed in the infiltrating part of the tumors, indicating a possible involvement of nestin in tumor invasion.

Transitional cell carcinoma of the renal pelvis and its expression of p53 protein, c-erbB-2 protein, neuron-specific enolase, Phe 5, chromogranin, laminin and collagen type IV

Expression of p53 protein, c-erbB-2 protein, neuron-specific enolase (NSE), Phe 5, chromogranin, laminin and collagen type IV was studied by immunohistochemistry in formalin-fixed and paraffin-embedded specimens from 20 patients with renal pelvic carcinoma. Positive membrane-bound c-erbB-2 staining was not found in any case. Two tumors stained for p53 protein. Focal immunoreactivity for laminin was present in 55% and for collagen type IV in 80%. 25% of the cases were NSE positive. None of the tumors stained for Phe 5 or chromogranin. The results were compared with the clinical outcome and the immunohistological findings of p53 protein and c-erbB-2 protein in 13 cases of bladder carcinoma in the same patient group. Four of the thirteen bladder cancer specimens, but only 2 of the 20 renal pelvic cancer specimens, expressed p53 protein. As for renal pelvic carcinoma, c-erbB-2 protein was not expressed in bladder carcinoma. We conclude that p53 gene abnormalities may be of importance in the development of carcinoma in the renal pelvis and urinary bladder, but c-erbB-2 protein expression does not play a major role.

Microsatellite instability is associated with tumors that characterize the hereditary non-polyposis colorectal carcinoma syndrome

Microsatellite instability implying multiple replication errors (RER+ phenotype) characterizes a proportion of colorectal carcinomas, particularly those from patients with the hereditary non-polyposis colorectal carcinoma syndrome. We studied the incidence of microsatellite instability in more than 500 sporadic tumors representing 6 different types of cancer. Apart from colorectal carcinoma [see the paper by Lothe et al. (Cancer Res., 53:5849-5852, 1993)] the RER+ phenotype was found in 18% (6 of 33) of gastric carcinomas and 22% (4 of 18) of endometrial carcinomas. In contrast, no evidence of this abnormality was detected in cancers of the lung (N = 85), breast (N = 84), and testis (N = 86). Importantly, the first three cancers, as opposed to the latter three, are characteristic of the hereditary non-polyposis colorectal carcinoma syndrome. These findings suggest that the cancers belonging to the hereditary non-polyposis colorectal carcinoma tumor spectrum may have essential pathogenetic steps in common, including a tendency to multiple replication errors.

p53 protein expression in squamocellular carcinomas of the lip

Twenty-six cases of squamocellular carcinomas of the lip were immunostained for p53 protein. Nuclear accumulation of p53 protein was observed in 88% of the 26 carcinomas, in 64% of adjacent "normal" epithelium and in all four cases with adjacent atypical squamous epithelium. 93% of the specimens (13/14) with p53 protein accumulation in "normal" epithelium demonstrated evidence of solar elastosis. UV radiation may induce p53 gene mutation as an early event in the neoplastic transformation.

Genetic alterations of the TP53 gene, p53 protein expression and HPV infection in primary cervical carcinomas

Primary cervical carcinomas from 92 patients were investigated for genetic alterations in the tumour suppressor gene TP53. Studies of allelic imbalance (AI) were performed by Southern blot analysis and by using two PCR (polymerase chain reaction) polymorphisms within the TP53 gene. AI in the tumour was observed in 22 per cent (11 of 52 informative patients) and was significantly associated with recurrence both in a univariate (P = 0.013) and in a multivariate (P = 0.045) analysis. The DNA samples were subjected to mutation analysis of four of the conserved domains in the TP53 gene, using PCR followed by constant denaturant gel electrophoresis (CDGE). Mutations were observed in 2 of 92 tumours (2 per cent), of which one was a silent mutation and the other a frameshift. Overexpression of the p53 protein was found by immunostaining of sections from formalin-fixed, paraffin-embedded material in 55 per cent (51/92) of the tumours. In 88 per cent (45/51) of these, overexpression was present in less than 5 per cent of the tumour cells. Overexpression was significantly associated with relapse-free survival only in a univariate analysis (P = 0.045). AI of the TP53 locus did not correlate with p53 expression or mutation. The important gene on 17p, responsible for the shorter disease-free survival for patients with AI of TP53, may therefore be another gene closely linked to TP53. In addition, the 92 tumour samples were tested for the presence of human papillomavirus (HPV) types 16 and 18. Fifty-four per cent (50/92) of the samples were positive for HPV 16 using in situ hybridization, and 93 per cent (86/92) using the PCR technique. The numbers for HPV 18 were 15 per cent (14/92) and 23 per cent (21/92), respectively. Twenty-one per cent (19/92) were positive for both HPV 16 and HPV 18, while 4 per cent (4/92) were negative for both HPV 16 and 18. The tumour with the frameshift TP53 mutation was HPV 16-positive, and the four samples negative for HPV 16 and 18 did not contain TP53 mutations within the conserved domains but had elevated p53 protein expression.

Prognostic significance of TP53 alterations in breast carcinoma

Constant denaturant gel electrophoresis (CDGE) was used to screen 179 breast carcinomas for mutations in the conserved regions of the TP53 gene (exons 5 through 8). Mutations were found in 35 of 163 primary tumours (21%) and in 5 of 16 metastases (31%) and resided predominantly in exon 7. The majority of the mutations were G:C-->A:T transitions. Immunohistochemistry demonstrated nuclear accumulation of p53 protein in 35 of 162 primary tumours (22%) and in four of 15 metastases (27%). TP53 mutation was strongly associated with nuclear accumulation of p53 protein. In total 42 of 163 primary tumours (26%) and 5 of 16 metastases (31%) were demonstrated to contain TP53 alterations (mutation and/or nuclear protein accumulation). TP53 alteration in primary tumour was significantly associated with the following parameters: positive node status, T status > 1, negative oestrogen receptor status, negative progesterone receptor status, presence of ERBB2 gene amplification, and invasive ductal histology. Furthermore, there were statistically significant associations, independent of other prognostic factors, between TP53 alterations in primary tumour and disease-free and overall survival.

[Injuries of the hand caused by high-pressure air]

Based on two cases of accidental high-pressure air injection injury to the hand, we describe pathology, symptoms and therapeutic principles. Despite nontoxicity of injected air, the importance of acute surgical intervention must be emphasized, as there is a risk of high-pressure soft tissue damage. The treatment suggested is: 1) systemic medication including tetanus toxoid and antibiotics, 2) adequate incision, decompression, exploration, drainage and debridement under either general, plexus or i.v. anaesthesia. Postoperatively, the hand should be elevated, and a program of physical mobilisation should be started as soon as possible.

Laminin production and fibronectin immunoreactivity in breast carcinomas

Eighty-nine cases of primary breast carcinoma were evaluated immunohistochemically for basement membrane laminin and fibronectin (FN). 58 of the cases were also examined by transmission electron microscopy (TEM). Intraductal carcinomas were all positive for laminin and FN and by electron microscopy a continuous BM was found in all of them. Among invasive tumors, immunoreactivity for laminin was expressed in 31% of cases and FN in 66%, whereas TEM revealed BM in only 4 out of 52 (8%) studied cases. Tumors measuring 10 mm or less were more often laminin-positive and FN-negative than larger tumors. There was a tendency for lymph node negative tumors to express laminin more often, but there was no relation between lymph node status and FN. Laminin immunostaining proved to be very useful in identifying vascular invasion. The laminin and FN immunoreactivity showed no significant correlation with overall survival and disease-free survival (DFS) of the breast cancer patients. DFS for cases with laminin positive tumors was 50% and for laminin negative tumors 46.8%. For cases with tumors immunoreactive for FN, DFS was 50%, and for tumors lacking FN 43.5%.

Squamous cell carcinomas. An immunohistochemical study of cytokeratins and involucrin in primary and metastatic tumours

The expression of cytokeratins (CK) 1, 4, 5/6, 8, 13, 18, 19 and 20 and involucrin in 42 cases of squamous cell carcinomas from various locations was examined. The tumours expressed CK5/6 in 55%, CK8 in 76%, CK13 in 43% and CK19 in 95% of cases. The CK5/6-positive primary tumours were from uterine cervix, head and neck, lung, skin, oesophagus and urinary bladder, and the CK13-positive primary tumours were from uterine cervix, lung and vulva. Metastatic squamous cell carcinomas from head and neck more frequently expressed CK5/6 and 13, 7/7 (100%) and 6/7 (86%) compared with 3/5 (60%) and 0/5 (0%) in the primary squamous cell carcinomas. Few cases were CK1, CK4 and CK18 immunoreactive. CK20 immunoreactivity was not observed. Involucrin was expressed in 71% of tumours, and most of the involucrin-positive cells were located at the central parts of tumour cell clusters except for one case in which the peripheral cells around tumour cell clusters were positive. Thus, expression of the so-called simple epithelial markers CK8 and CK19 occurs in the majority of squamous cell carcinomas. The absence of CK20 immunoreactivity may be helpful in differential diagnosis.

Overexpression of p53 protein and c-erbB-2 protein in small cell carcinoma of the cervix uteri

Twenty-eight primary small cell carcinomas of the cervix uteri were examined immunohistochemically for overexpression of p53 protein and c-erbB-2 protein. Twenty-one per cent of the cases showed positive immunostaining for p53 protein, whereas no staining was observed using the antibody against c-erbB-2. Our results indicate that altered expression of p53 protein may be involved in the development of small cell carcinoma of the cervix uteri.

Undifferentiated carcinoma: an immunohistochemical and ultrastructural study

Twenty-eight undifferentiated carcinomas (UCs) were immunohistochemically investigated with antibodies against cytokeratins (CKs), vimentin, p53 protein, c-erbB-2 protein and CEA. The diagnoses were based on the findings of conventional histopathology, immunohistochemistry and electron microscopy. CKs8, 18 and 19 were the CKs most frequently present in these tumors, in 61%, 61% and 82% of the cases, respectively. Nine of the 28 (32%) UCs were CKs5/6 positive. Expression of CK20 was found in three (11%) cases. Four UCs were sub-type Cks negative, but one of them was confirmed AE1/AE3 positive. P53 protein overexpression was found in nine (32%) cases. One of the patients with p53 protein positive tumors has been alive for 174 months. Nine (32%) UCs expressed vimentin, which included all of the three thyroid UCs. Comparing with our previous study of squamous cell carcinomas, we found that vimentin and CK18 are more frequently expressed in UCs. The overexpression of p53 protein is similar in the two groups of carcinomas and thus, p53 protein is not a differentiation marker in these tumors. Finally, we recommend the use of a CK "cocktail of antibodies" in the diagnosis of UCs.

p53 abnormalities in different subtypes of human sarcomas

In this report we examined p53 alterations at the DNA, mRNA, and protein levels on tissue from 39 patients with different subtypes of sarcoma. Loss of heterozygosity for the chromosome 17p region was found in 60, 63, and 33% of 10 informative osteosarcomas, 11 malignant fibrous histiocytomas, and 6 leiomyosarcomas, respectively. In addition, 2 of 10 tumors belonging to a heterogeneous group of soft tissue sarcomas showed loss of heterozygosity. Elevated levels of p53 mRNA were found in six tumors, four had a truncated transcript, and in six patients no mRNA was detected. In most cases, elevated transcript levels were accompanied by overexpression of protein as studied by immunohistochemistry, whereas the presence of truncated transcripts was associated with negative immunostaining. Point mutations in exons 5, 7, or 8 of the TP53 gene were detected in seven tumors. Six of these expressed high levels of mRNA and protein, probably reflecting a point mutation in one of the alleles and loss of the other. Three of the mutations have not previously been described. Taken together, p53 abnormalities were found in approximately 65% of the osteosarcomas, malignant fibrous histiocytomas, and leiomyosarcomas examined and in 30% of the other soft tissue tumors. The results indicate that the TP53 gene is involved in the tumorigenesis of several sarcoma subtypes in a higher fraction of cases than was previously recognized.

No germline TP53 mutations detected in familial and bilateral testicular cancer

Mutations in the TP53 gene are considered to be among the most common genetic alterations in human cancers. Both somatic and germline mutations have been found. Using polymerase chain reaction (PCR), constant denaturant gel electrophoresis (CDGE), and denaturing gradient gel electrophoresis (DGGE), we have examined 32 patients with bilateral and familial germ cell tumors (GCT) and two patients with sporadic GCT for germline mutations within the conserved regions of the gene. In addition, 15 tumors were screened for somatic mutations and analyzed for loss of heterozygosity (LOH) at the TP53 locus. Twelve tumors were analyzed for expression of TP53 via immunohistochemistry. Neither germline nor somatic TP53 mutations were detected. LOH was observed in one of five informative cases. No tumors showed increased expression of TP53 protein. These results indicate that alterations in the TP53 gene are not important for the predisposition to and development of GCT.

[Transgenic mice as animal model of Cushing's syndrome]

Transgenic mice were generated with the polyoma early region promoter linked to cDNA encoding polyoma large T antigen (PyLT). Light microscopic examination showed up to 5 mm large pituitary adenomas in clinically ill transgenic mice. The tumour cells showed positive ACTH immuno-reactivity. The adrenal glands of clinically ill mice showed an increase in weight and exhibited medullary hyperplasia. These findings were unexpected, and might have been caused by transgene expression in the neuroendocrine cells of the adrenal medulla. Plasma ACTH measurements showed significantly increased levels in clinically ill PyLT-1 transgenic mice.

Immunohistochemical analysis of p53 protein overexpression in normal, premalignant, and malignant tissues of the cervix uteri

Two hundred and thirty-eight cervical lesions ranging from normal to malignant were examined for overexpression of p53 protein. Whereas p53 protein was identified in 62 per cent of invasive squamous cell carcinomas, 11 per cent of invasive adenocarcinomas, and 7 per cent of squamous cell carcinomas in situ, no staining was found in adenocarcinoma in situ, dysplastic tissue, condyloma, and normal tissue. In 9 per cent of the positive cases of invasive squamous cell carcinomas, 5-50 per cent of the tumour cells were immunoreactive for p53 protein, whereas the other positive specimens were characterized by only rare p53-positive cells. We conclude that in invasive cervical carcinomas widespread overexpression of p53 protein is unusual, but occasional positive nuclei can be found frequently. Furthermore, our results indicate that altered expression of p53 protein may be involved in the progression of cervical carcinomas.

ACTH-producing pituitary tumors in transgenic mice. An ultrastructural and immunoelectron microscopic study

Ultrastructural and electron microscopic immunohistochemical features of corticotropic pituitary tumors arising in polyoma large T transgenic mice and the corresponding tumor transplants in non-transgenic mice are reported. Spherical, irregular and drop-shaped secretory granules measuring 150-450 nm in diameter, were seen in all tumors. Both in tumors from transgenic mice and in tumor transplants immunoreactivity for adrenocorticotropic hormone (ACTH) and beta-endorphin was expressed in the majority of the secretory granules, whereas growth hormone (GH) immunoreactivity was demonstrated only in a small number of cells in tumors from transgenic mice. In addition, positive immunostaining for neuron-specific enolase (NSE) and synaptophysin was found in the two pituitary tumor transplants tested. The study shows that the pituitary tumors from transgenic mice and their tumor transplants have features similar to human corticotropic pituitary tumors, and may therefore be a valuable model for experimental studies of the tumorigenesis.

Squamous cell carcinomas, an immunohistochemical and ultrastructural study

Fourty-seven squamous cell carcinomas (SCCs) were studied by light microscopy, immunohistochemistry and electronmicroscopy. Nineteen percent (9 cases) of SCCs in different locations were immunoreactive for CAM5.2 and three poorly differentiated SCCs did not express cytokeratins 6 and 18. No cases were positive for c-erbB2 protein. p53 protein overexpression was found in malignant cells in 40% of the primary tumours and in 60% of the lymph node metastases. Four poorly differentiated SCCs expressed vimentin and in these cases the tumour cells had accumulations of less dense intermediate filaments in cytoplasm.

c-erbB-2 expression in primary gastric carcinomas and their metastases

In an attempt to evaluate the relationship between c-erbB-2 expression and/or gene amplification, DNA ploidy and morphology, wall penetration, lymphatic permeation, and vascular invasion, we studied a series of 87 primary gastric carcinomas and their respective metastases (n = 335) using immunohistochemistry and performed DNA analysis of 30 primary tumors and 10 metastases from eight cases. Flow cytometry of fresh or frozen material was performed in 79 primary tumors. Five out of 87 primary tumors (5.7%) and 17 out of 335 lymph node metastases (5.1%) showed unequivocal membrane immunostaining for c-erbB-2. Seven out of 30 primary tumors (23.3%) showed gene amplification while amplification was identified in four out of 10 metastases (40.0%) from three patients. Eight tumors (9.2%) showed c-erbB-2 protein immunoreactivity, gene amplification, or both. One of these cases showed c-erbB-2 protein immunoreactivity only in the metastatic deposits, while gene amplification could be identified in the primary tumor. Three primary tumors showed gene amplification, but immunoreactive cells could not be identified. In no case was protein overexpression identified in the absence of gene amplification. Five cases with c-erbB-2 expression/amplification were well/moderately differentiated, and all the eight cases with c-erbB-2 expression/amplification disclosed aggressive features. Lymphatic permeation/lymph node metastases were found in all the cases and seven cases showed vascular invasion as well. In one case, there was also a liver metastasis. Two cases were early gastric carcinomas (T1sm) showing lymphatic permeation/nodal metastases and venous invasion. Six cases were aneuploid.(ABSTRACT TRUNCATED AT 250 WORDS)

In situ hybridization with nonisotopic probes using different detection systems

In order to evaluate a sensitive nonisotopic in situ hybridization method for routine work in pathology laboratories, we compared seven different detection systems, using digoxigenin- and biotin-labeled probes. The sensitivity of these methods was tested on four cases of cervical condyloma all known to be positive for HPV 6. Four of these methods gave satisfactory results without any background staining. The single biotin method and the single digoxigenin method were equally sensitive, while the two triple biotin methods, using mouse anti-biotin/anti-mouse IgG/alkaline phosphatase mouse anti-alkaline phosphatase or mouse anti-biotin/alkaline phosphatase anti-mouse IgG/alkaline phosphatase mouse anti-alkaline phosphatase as the detection systems, tremendously improved the sensitivity. The enhanced sensitivity of the nonisotopic in situ hybridization method make it useful in investigation of pathologic tissues.