MDR-1 expression in non-Hodgkin's lymphomas is unrelated to treatment intensity or response to therapy

Over-expression of the MDR-1 gene, which codes for P-glycoprotein, is thought to be an important mechanism in the drug resistance exhibited by many tumours. A number of chemotherapeutic agents which induce MDR-1 expression are also components of combination chemotherapies that are used in the treatment of high grade non-Hodgkin's lymphomas (NHL). We have therefore examined expression of MDR-1 in a series of NHL by Northern blot analysis as well as investigated the localization of P-glycoprotein by immunohistochemistry. The series included 11 hyperplastic reactive nodes and tonsils, 17 low grade NHL and 15 high grade NHL. The levels of MDR-1 mRNA were quantified by scanning densitometry and comparison with levels of glucose-6-phosphate dehydrogenase (G6PD). The MDR-1 mRNA was observed in both non-malignant and NHL tissues. Immunohistochemical staining revealed that expression of MDR-1 mRNA in reactive nodes was related to the presence of P-glycoprotein in lymphocytes, however, P-glycoprotein was apparent in both the reactive lymphocytes and tumour cells in the NHL samples. Elevated mRNA levels (2-3 fold increase) were observed in some low grade and high grade NHL relative to those observed in reactive lymphoid tissue. There appeared to be little correlation, however, between expression of the MDR-1 gene and either treatment intensity or response to therapy. The drug resistance that is often encountered in NHL patients is therefore likely to involve mechanisms other than over-expression of P-glycoprotein.

Elevated levels of MDM-2 and p53 expression are associated with high grade non-Hodgkin's lymphomas

The role of p53 in the evolution of non-Hodgkin's lymphomas (NHL) is unclear. Mutations of the p53 gene appear to be relatively uncommon but stabilized p53 protein, as detected by immunohistochemistry, has indicated a more frequent involvement of p53. As dysfunction of p53 protein has also been suggested to occur after overexpression of the mdm-2 protein, we have therefore investigated a series of non-malignant hyperplastic reactive lymphoid tissues and NHL to examine whether the levels of expression of MDM-2 correlated to positivity of p53 protein staining. Northern blot analysis of MDM-2 expression was compared to glucose-6-phosphate dehydrogenase (G6PD) expression by densitometry to quantify the relative levels of MDM-2 expression. Consistent low levels of MDM-2 expression were observed in non-malignant lymphoid tissue and in low grade NHL, however, 13/15 high grade NHL exhibited a 2-15-fold increase in MDM-2 expression. Interestingly similar elevations in p53 mRNA expression were also observed in 6/15 high grade NHL. Positive staining of the p53 protein did not, however, correlate with elevated mRNA levels of either MDM-2 or p53. The significance of these observations is discussed.

Isolated xanthogranuloma of the limbus in an adult

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2D-gel analysis of protein synthesis profiles of different stages of chronic lymphocytic leukaemia

Protein synthesis profiles of leukaemic cells from 15 chronic lymphocytic leukaemia (CLL) patients were analysed by 2D-electrophoresis of 35S-methionine labelled proteins. This series of CLL included patients with stage A (7), B (4) and C (4) disease. Although the protein synthesis profiles were similar in all cases, some consistent differences were noted between the different stages. The levels of synthesis of three proteins (approximately 35 kD size) were of particular interest. Two of these were always expressed in stage C CLL but either infrequently or not at all in stage A or B CLL. By contrast a third protein was expressed at a much reduced level in stage C compared to stages A or B. This type of analysis could prove invaluable for identifying proteins whose expression was intimately associated with the evolution of CLL.

Comparison of protein synthesis profiles in chronic lymphocytic leukaemia cells and B-lymphocytes from peripheral blood, cord blood and tonsil

2D-gel electrophoresis was used to investigate protein synthesis in leukaemic cells from a series of 15 chronic lymphocytic leukaemia (CLL) patients, and in non-malignant B-cell populations from different sources. The protein synthesis profiles of CD5+ B-cells from umbilical cord blood and from tonsil were determined, and the levels of expression of their proteins were observed to be similar to the CLL cells. The CD5- cells from cord blood resembled peripheral blood B-lymphocytes, and the protein synthesis profile of CD5- cells from tonsils was very complex. One protein was also identified which consistently appeared to be synthesised at a low level in CD5+ B-cells from tonsil but which was always more prominent in CLL cells and other non-malignant B-lymphocytes. On the basis of these data it is possible that the closest non-malignant counterpart to CLL is the CD5+ B-lymphocyte from cord blood.

Analysis of the p53 gene, its expression and protein stabilization in non-Hodgkin's lymphomas

We have investigated the p53 gene, expression of its mRNA, and stabilization of its protein in a series of non-Hodgkin's lymphomas (NHLs). Immunohistochemistry revealed positive staining of the p53 protein in node biopsies from 6/36 NHL patients, all of whom had high-grade disease. The remaining NHL samples, together with 3 reactive nodes, showed either negative staining or the staining of only occasional cells. In one case that exhibited intense nuclear staining in 90% of the cells, a mutation in the p53 gene was also observed. There was no evidence of rearrangements of the p53 gene in any of the NHL samples. Although p53 mRNA could not be detected in nonmalignant tissue, it was apparently overexpressed in 16/38 NHL, but this did not correlate with positive staining of the p53 protein. These data suggest that p53 dysfunction might play an important role in the evolution of some cases of NHL, and that mechanisms other than mutation of the p53 gene may be involved in stabilizing the p53 protein in these neoplasms.

Investigation of the activation state of the X chromosome in non-Hodgkin's lymphomas

Cytogenetic analysis of non-Hodgkin's lymphomas (NHLs) has previously revealed a high incidence of numerical abnormalities involving the X chromosome. We have now used a combination of fluorescence in situ hybridization (FISH) and Southern blot analysis of methylation to examine the activation state of additional X chromosomes in NHL. Although FISH analysis of X chromosome centromeres in interphase nuclei was complicated by a number of factors, such as cell-cycle position, there was evidence that more than one X chromosome was present in the active state in 4/9 NHL. Methylation studies were carried out using the M27 beta probe, which also suggested that more than one activated X chromosome was present in at least 2/7 NHL cases. The two approaches therefore provided evidence that in some cases of NHL, unlike sex-chromosome-syndrome individuals, additional X chromosomes may be present in the active state. These data support the suggestion that NHL-associated oncogenes might be located on the X chromosome.

Investigation of BCL-2 gene rearrangements in a United Kingdom series of low and high grade non-Hodgkin's lymphomas

Rearrangements of the BCL-2 gene are thought to be the most frequent genetic changes that occur in non-Hodgkin's lymphomas (NHL), and are particularly associated with follicular low grade disease. Wide variations in the frequency of these rearrangements have, however, been reported in studies of NHL series from different parts of the world. We were therefore interested to determine the frequency of BCL-2 gene rearrangements in the different grades of NHL from a U.K. series. We have done this by using a combination of Southern blot hybridization and polymerase chain reaction (PCR) analysis. The frequencies of rearrangements in our series were 9/20 (45%) in low grade follicular NHL, 1/8 (12.5%) in low grade lymphocytic and 5/19 (26%) in high grade NHL. However, estimation of the high grade value was complicated by the fact that a number of the high grade samples in our series were from patients who had transformed from low grade follicular disease. If the patients were ranked on the basis of whether they had a history of low grade follicular disease then the frequency of BCL-2 rearrangement remained the same 13/29 (45%), but was only 1/10 (10%) in high grade NHL with no history of follicular disease. The former figure was intermediate between those reported for the USA and Japan series, but the latter high grade figure was the lowest reported from any series. The significance of BCL-2 rearrangements in the evolution of both low and high grade NHL is discussed.

Investigation of the expression of housekeeping genes in non-Hodgkin's lymphoma

Studies of quantitative changes in gene expression in malignant cells have often used housekeeping genes as controls against which the level of expression of a gene under study could be compared. We have now examined whether the expression of the most commonly used of these housekeeping genes can be regarded as reliable controls for gene expression studies in non-Hodgkin's lymphoma (NHL). We have used Northern blot analysis to compare the levels of expression of beta-actin, alpha-tubulin, beta 2-microglobulin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) to that of ribosomal RNA. These studies demonstrated that whereas there was a reasonable correlation between the relative levels of rRNA and housekeeping gene expression in reactive hyperplastic nodes, there were major differences in the relative levels of expression of the housekeeping genes in both low and high grade lymphomas; only GAPDH showed any degree of consistency. These observations indicated that housekeeping gene expression was not a reliable control for estimating changes in the level of expression of other genes in NHL, and instead suggested that 18S or 28S rRNA expression offered a more accurate method of RNA quantitation.

2D-gel analysis of proteins in chronic lymphocytic leukemia cells and normal B-lymphocytes

Protein synthesis was analysed in leukaemic cells from 10 chronic lymphocytic leukaemia (CLL) patients by 2D-gel electrophoresis of 14C-labelled proteins. There appeared to be only minor differences between each of the CLL samples, but there was evidence that the level of expression of a few of the proteins might have correlated to the stage of the disease. Comparison of the CLL samples to populations of normal B-lymphocytes demonstrated marked differences in protein synthesis between the leukaemic and non-malignant cells. We subsequently used the fluorescence activated cell sorter (FACs) to separate CD5+ from CD5- B-lymphocytes, but observed that the protein synthesis exhibited by these two populations was essentially the same, and both were very different to that observed in CLL cells. The significance of these observations with respect to the origins of CLL is discussed.

Cytogenetic analysis of a United Kingdom series of non-Hodgkins lymphomas

We describe cytogenetic analyses of cells derived from 40 non-Hodgkins lymphoma (NHL) node biopsies, 23 of which were from patients who had not been treated before biopsy. We noted that the chromosomes most frequently gained were X (32%), 12 (27%), and 3 (24%). Monosomies were much less common; loss of chromosome 13 (13.5%) was most frequent. Structural abnormalities primarily involved chromosomes 14 (70%), 1 (40.5%), 18 (38%), 6 (35%), and 17 (22%). Low-and high-grade disease showed similar patterns of structural changes; however, a markedly greater number of chromosome gains were associated with low-grade disease. Biopsy samples from patients who had previously been treated showed an increased frequency of structural abnormalities, as well as a significantly larger number of chromosome gains. The importance of these observations, particularly with regard to possible oncogene involvement in lymphoma evolution, is discussed.

Loss of monomorphic and polymorphic HLA antigens in metastatic breast and colon carcinoma

MHC class I antigens are intimately involved in intercellular communication, and recognition by cytotoxic T cells. Thus tumour cells that fail to express them may be at a growth or metastatic advantage. A series of ten colorectal and ten breast carcinomas, and their respective lymph node metastases, were examined immunohistologically using monoclonal antibodies (mAb) against both monomorphic and A2 polymorphic determinants, and beta-2-microglobulin (beta 2m). Four colon polypoid adenomas stained positively throughout, but 6/10 primary tumours had partial or complete loss of expression of monomorphic determinants using mAb W6/32: two node and the liver metastasis showed less, four more expression. Similar results were seen for beta 2m. HLA-A2 expression was absent or reduced in 4/4 colon tumours and all their metastases. Among the breast tumours, W6/32 staining was absent or reduced in 2/10, and node deposits showed two with less reactivity than their primary. Beta 2m staining was reduced or absent in 8/10 primaries and all the node metastases; in every case in which beta 2m was detected in the primary tumour their corresponding lymph node metastasis showed a decreased expression. HLA-A2 expression was absent or reduced in 3/4 primary breast carcinomas, and all their metastases. These results show that individual human colon and breast carcinomas often have a reduced HLA class I antigen expression, which apparently confers a metastatic advantage.

Natural killer cell activity following cryosurgery of normal and tumour bearing liver in an animal model

Cryosurgery is a useful tool to treat unresectable liver carcinoma. In addition to the local effects of freezing, cryosurgery is thought to affect host immune response. We tested this by measuring natural killer (NK) cell cytotoxicity following cryosurgery of normal liver and an implanted liver tumour in the rat. Controls underwent sham cryosurgery. NK cytotoxicity was enhanced following cryosurgery of normal liver and liver tumour.

Somatic allelic deletion of nm23 in human cancer

Tumor progression to the metastatic phenotype is accompanied in certain cell types by reduced expression of the nm23 gene. We have localized human nm23-H1 to chromosome 17 by somatic cell hybrid analysis. Regional localization in the CEPH database and in situ hybridization is reported. Somatic allelic deletion of nm23-H1 was observed in human breast, renal, colorectal, and lung carcinoma DNA samples, as compared to DNA from matched normal tissues. A homozygous deletion of nm23-H1 was observed in a lymph node metastasis of a colorectal carcinoma, indicating that nm23-H1 can be recessively inactivated. The data identify nm23-H1 as a novel, independent locus for allelic deletion in human cancer, a characteristic shared with previously described suppressor genes.

Intra-abdominal neuroectodermal tumour of childhood with divergent differentiation

Two cases are reported of intra-abdominal small cell tumours expressing concomitant neural and epithelial differentiation. These features were discernible on conventional microscopy and supported immunocytochemically. Immunoreactive vimentin was also revealed in both tumours, and, in addition, one showed focal desmin positivity. Epithelial differentiation in both tumours was confirmed ultrastructurally. The tumours were interpreted to represent a variant of peripheral primitive neuroectodermal tumour, and the report serves to emphasize a potential among such tumours for complex differentiation. The neoplasms are compared with other similar tumours reported recently in children.

Secondary tumour deposits in needle biopsy tracks: an underestimated risk?

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Basosquamous carcinoma, a wolf in sheep's clothing? Report of 3 cases

Basosquamous carcinoma of the skin is a lesion with specific histological features and recognized metastatic potential. Three cases of metastatic basosquamous carcinoma are reported, two of which were rapidly fatal. They illustrate that diagnostic features may be absent in a small biopsy and that metastasis is usually associated with a poor prognosis.

Metastatic teratoma associated with an intra-abdominal abscess

A case of metastatic testicular teratoma is reported where histological evidence of metastatic disease was obtained 12 years after orchidectomy. The patient had presented again 2 years earlier but the presence of a large intra-abdominal abscess delayed the diagnosis of recurrence. At no time were the serum levels of alpha-fetoprotein or beta human chorionic gonadotrophin elevated.

Immunohistological demonstration of progesterone receptor in breast carcinomas: correlation with radioligand binding assays and oestrogen receptor immunohistology

The validity of determining the progesterone receptor status of breast carcinomas with a monoclonal antibody was investigated by comparison with data from a radioligand binding assay on adjacent cryostat sections of 103 tumours. Significant nuclear staining for progesterone receptor was observed in 37 (36%) of the tumours studied and this showed a close correlation with the results of radioligand binding assays for progesterone receptor. In three progesterone receptor positive tumours there was an apparent paradoxical absence of oestrogen receptor; progesterone receptor normally depends on the presence of oestrogen receptor, but these rare tumours may be essentially progesterone receptor positive. It is concluded that this monoclonal antibody is an appropriate reagent for use in the immunohistological determination of progesterone receptor status of breast carcinomas; that it advantageously identifies both the occupied and unoccupied receptor sites; and that it provides information about tumour cell heterogeneity with respect to receptor status.

Comparison of excision versus cryosurgery of an HSV-2-induced fibrosarcoma. I. Survival, extent of metastatic disease and host immunocompetence following surgery

Cryosurgery and excision were used to treat primary tumours of HSV-2-transformed hamster tumour sublines, and post-operative survival and the extent of metastatic disease were compared in the two groups. An inferior prognosis was observed following cryosurgery although the extent of metastatic disease was similar in both groups. Using this model it would appear that cryosurgery enhances the development of micrometastases rather than affecting the number of cells shed from the primary tumour during surgery. To investigate the underlying causes of the decrease in survival following cryosurgery, in vitro assays were used to monitor host immunocompetence following surgery. The results showed that whilst natural killer cell cytotoxicity was only marginally depressed, mitogen responsiveness and lymphocyte participation in a mixed lymphocyte reaction were severely reduced 3-7 days post-cryosurgery. In parallel with immunosuppression, extensive cell proliferation in the spleen of cryosurgically treated tumour-bearing animals was observed. Histological examination of the spleen demonstrated the presence of large numbers of transformed cells which correlated with the loss of mitogen responsiveness and the ability to participate in a mixed lymphocyte reaction. Further studies (manuscript submitted for publication) have demonstrated that spleen cells from animals whose tumour is treated by cryosurgery are capable of suppressing immunocompetence in vitro, implying they have a role in the uncontrolled growth of micrometastases in vivo.

The effect of the immune status of the TAR mouse on the growth and metastasis of tumour xenografts

Mice thymectomised at 3-4 weeks of age and subsequently given whole-body irradiation (9 Gy) under cytosine arabinoside cover (TAR mice) provide an alternative model to the athymic nude (nu+/nu+) mouse for studying the biological characteristics of tumour xenografts. In the present study we have evaluated the repopulation events in the bone marrow and spleen following whole body irradiation of TAR mice, and analysed immune competence up to 98 days following irradiation. Repopulation of both bone marrow and spleen was evident in the weeks following whole body irradiation, and an initial increase in the relative proportion of T-lymphocytes present in the spleen was followed by a decrease in the percentage of lymphocytes expressing T-cell markers, which remained below the level observed in control mouse spleen cell preparations. TAR mice exhibited a decreased ability to respond to a non-specific T-cell mitogen and to elicit a T-cell dependent antibody response to influenza viral antigen. Both TAR and control mice possessed macrophages which could be activated to the tumouricidal state, and natural killer activity of TAR mice was enhanced greater than 3-fold above control values. The ability of TAR mice to accept tumour xenografts decreased with the increasing time interval between irradiation and subcutaneous implantation of tumour cells, and (in some instances) spontaneous regression was observed. In addition, a hamster tumour cell line possessing high metastatic potential in its syngeneic host was shown to metastasise to the regional lymph node, lungs, liver, kidneys and spleen of TAR mice from a cell inoculum implanted subcutaneously immediately after irradiation; however, with increasing time between irradiation and inoculation of tumour cells tumour metastasis decreased. The ability of TAR mice to support the growth and metastasis of tumour xenografts would appear to inversely correlate with the increase in natural killer cell activity following irradiation.

Bilateral pneumothorax secondary to metastatic angiosarcoma of the breast

Bilateral spontaneous pneumothorax is a rare complication of pulmonary metastases. We report a 44 year old woman who developed this complication a few months after undergoing mastectomy and postoperative radiotherapy for primary angiosarcoma of the breast.

Giant vascular eccrine spiradenomas: a report of two cases with histology, immunohistology and electron microscopy

Two examples of a variant of benign spiradenoma are reported, both characterized by their large size and high degree of vascularity. The results of studies using light microscopy, transmission electron microscopy and immunohistology are described. The relationship of this unusual variant to other spiradenomas and their eccrine sweat gland origin is discussed. The possible misdiagnosis of this rare type of spiradenoma is emphasized.

Haematuria due to urinary bladder metastases from small cell carcinoma of the bronchus

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