Dysplastic Epithelial Cells Research Articles

Urokinase type plasminogen activator receptor expression in colorectal neoplasms

Background—The urokinase type plasminogen activator receptor (uPAR) may play a critical role in cancer invasion and metastasis.Aims—To study the involvement of uPAR in colorectal carcinogenesis.Methods—The cellular expression and localisation of...

Malignant tumors of the kidney, brain, and soft tissues in children and young adults with the tuberous sclerosis complex

BACKGROUND The tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by seizures, mental retardation, and benign tumors of the brain, heart, skin, and kidney. Malignant tumors also can occur in patients with tuberous sclerosis, particularly in the kidney, although they occur less frequently than benign tumors. The types of malignancy that occur in TSC have not been characterized fully. METHODS Clinical and pathologic features of 8 malignant tumors from 6 TSC patients ranging in age from 22 months to 21 years are reviewed. Six tumors were renal, one was from the inguinal region, and one was from the brain. The tumors were analyzed for loss of heterozygosity (LOH) in the chromosomal regions of the TSC1, TSC2, and VHL genes. RESULTS Three patients (ages 7, 8, and 20 years) had renal cell carcinomas (RCCs). Two of these patients had multifocal RCCs. All three patients with RCC also had prominent multifocal dysplasia of renal cyst epithelium. Two patients (ages 20 and 21 years) had malignant angiomyolipomas (1 renal and 1 inguinal). One patient (age 22 months) had a Grade 4 giant cell astrocytoma (glioblastoma multiforme). LOH in the region of the TSC2 gene was found, either in the malignant tumor or in benign tumors, in all five patients whose DNA could be analyzed. CONCLUSIONS Children with TSC, as well as adults with the disease, are at risk for developing malignant tumors. Two types of renal malignancy occur in TSC: RCC, which appears to arise from dysplastic renal cyst epithelial cells, and malignant angiomyolipoma. Tumors cytologically similar to malignant angiomyolipomas also may occur at extrarenal sites. LOH analyses suggest that the majority of patients with TSC who develop malignant tumors have germline TSC2, rather than TSC1, gene mutations. Cancer 1998;83:2208-2216. © 1998 American Cancer Society.

Malignant tumors of the kidney, brain, and soft tissues in children and young adults with the tuberous sclerosis complex

The tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by seizures, mental retardation, and benign tumors of the brain, heart, skin, and kidney. Malignant tumors also can occur in patients with tuberous sclerosis, particularly in the kidney, although they occur less frequently than benign tumors. The types of malignancy that occur in TSC have not been characterized fully. Clinical and pathologic features of 8 malignant tumors from 6 TSC patients ranging in age from 22 months to 21 years are reviewed. Six tumors were renal, one was from the inguinal region, and one was from the brain. The tumors were analyzed for loss of heterozygosity (LOH) in the chromosomal regions of the TSC1, TSC2, and VHL genes. Three patients (ages 7, 8, and 20 years) had renal cell carcinomas (RCCs). Two of these patients had multifocal RCCs. All three patients with RCC also had prominent multifocal dysplasia of renal cyst epithelium. Two patients (ages 20 and 21 years) had malignant angiomyolipomas (1 renal and 1 inguinal). One patient (age 22 months) had a Grade 4 giant cell astrocytoma (glioblastoma multiforme). LOH in the region of the TSC2 gene was found, either in the malignant tumor or in benign tumors, in all five patients whose DNA could be analyzed. Children with TSC, as well as adults with the disease, are at risk for developing malignant tumors. Two types of renal malignancy occur in TSC: RCC, which appears to arise from dysplastic renal cyst epithelial cells, and malignant angiomyolipoma. Tumors cytologically similar to malignant angiomyolipomas also may occur at extrarenal sites. LOH analyses suggest that the majority of patients with TSC who develop malignant tumors have germline TSC2, rather than TSC1, gene mutations.

Local Cellular Immune Response in Dysplastic Epithelial Lesions of the Flat Colonic Mucosa

This is an immunohistochemical study of the local cellular immune response characteristic in inflammatory-regenerative and dysplastic flat colonic mucosa. The aim of this study is to determine a possible existence of the mononuclear cellular infiltration specificity which could be important for the prognosis in further development of dysplastic lesion. Biopsy specimens from 170 patients (specimens stained by hematoxylin eosin) were examined. 74 specimens showed inflammatory-regenerative changes and 96 had dysplastic changes (38 with mild dys-plasia, 28 with moderate dysplasia and 30 with severe dysplasia). Three monoclonal antibodies were used for the identification of mononuclear cells in the inflammatory cellular infiltration in the lamina propria of colonic mucosa. The inflammatory cells type and their location in respect of the epithelial cells and lesion itself were analysed and their number was determined by the semi-quantitative method. T lymphocytes were the dominant cells of local immune response in dysplastic lesions while macrophages were less present and B lymphocytes, as rare cells, were present in sporadic cases. It is notified that increase in the extent of dysplasia was followed by increase in the number of macrophages and T lymphocytes in particular. Immediate contact between macrophages and T lymphocytes in epithelial dysplasia was found in a small number of cases and was mostly independent from the intensity of dysplasia. Signs of the direct lytical effect of the mononuclear ceils on dysplastic epithelial cells were not observed in this contact. It seems that epithelial dysplasia does not provoke more significant local immune response which is the most probably a part of the chronic non-specific inflammation that has a negative influence on further development of the lesion. The conclusion is that local immune response in the dysplastic alteration of flat colonic mucosa has no importance in further prognosis of the lesion.

Effects of melatonin on mammary gland lesions in transgenic mice overexpressing N-ras proto-oncogene.

The oncostatic effects of melatonin on the mammary gland have been studied in transgenic mice carrying the N-ras proto-oncogene under the control of the MMTV-LTR. Female (4-week-old) virgin mice with positive transgenic pedigrees were injected with melatonin (200 micrograms/mouse/ day, five times a week) or vehicle late in the evening. After 5 months of treatment, animals were sacrificed and the mammary glands were dissected for whole mounts, histology, and immunohistochemical analysis with a mouse monoclonal antibody specific for N-ras protein. Mammary glands of control transgenic mice showed different densities of hyperplastic alveolar nodules (HANs) consisting primarily of dysplastic epithelial cells with nuclear atypia and prominent nucleoli. The epithelial cells of HANs showed a high expression of N-ras while no immunostaining was detected in the unaffected mammary parenchyma. Only one (10%) of the control transgenic mice presented an infiltrating ductal carcinoma with the neoplastic cells overexpressing N-ras protein. The mammary glands of melatonin treated mice had a lower density of HANs, absence of epithelial dysplastic cells, and weak immunostaining of N-ras protein in comparison to the vehicle-treated group. None of the melatonin treated animals developed mammary carcinomas during the observation period. The lymph nodes of the inguinal mammary glands of all the vehicle-treated transgenic mice presented hyperplasia and two animals even had lymphomas, whereas in melatonin-treated animals there was less hyperplasia (two cases were atrophic) and a lack of lymphomas. We conclude that in the mammary glands of MMTV-LTR/N-ras transgenic female virgin mice, melatonin a) reduces the incidence of HANs and the expression of N-ras protein in focal hyperplastic lesions, b) completely prevents the development of epithelial cell atypia and mammary adenocarcinomas, and c) also reduces the hyperplasia of the mammary lymphoid tissue and prevents the development of lymphomas.

Ultrastructural Study of the Nuclei of Normal, Dysplastic, and Carcinomatous Epithelial Cells of the Human Cervix Uteri

The nuclei of epithelial cells of the uterine cervix of normal women and of patients with various degrees of dysplasia, carcinoma in situ, and invasive carcinoma were studied by means of electron microscopy. Nuclear ribonucleoprotein components and chromatin were contrasted using preferential methods for RNA and DNA. Changes in the distribution of the extranucleolar ribonucleoprotein-containing structures were found, ranging from low-grade dysplastic lesions to invasive carcinoma. Compared with normal epithelial cells, dysplastic and neoplastic cells possess more nuclear bodies, as well as deep invaginations of the nuclear envelope and lobulations. Morphometric parameters estimated were nuclear volume, numerical density of perichromatin granules (PCG), and fraction of nuclear volume occupied by compact chromatin. The pattern of values of these parameters in the cell layers of normal cervical epithelium was disrupted in all the lesions. These data suggest that the processes studied induce early alterations in transcription and processing and/or exportation of mRNA to the cytoplasm. Two populations of cells were found in invasive carcinomas, one with large nuclei, sparse compact chromatin, and few PCG, and the other with small nuclei, abundant compact chromatin, and numerous PCG. Their morphologic features indicate that the former population is composed of relatively undifferentiated cells, while the latter is made up of well-differentiated cells which could be neoplastic or entrapped normal cells.

Characterization of apomucin expression in intrahepatic cholangiocarcinomas and their precursor lesions: an immunohistochemical study.

To date, seven apomucins have been characterized and their expression in malignant and premalignant lesions is under evaluation. In this study, we examined the expression of MUC1, MUC2, MUC3, and MUC5/6 apomucins in cholangiocarcinoma (CC) and biliary epithelial dysplasia. We used 14 liver samples from patients with hepatolithiasis and CC, 11 with hepatolithiasis showing biliary epithelial dysplasia, 31 with CC alone (19 hilar, 10 peripheral, and 2 unclassifiable), and 14 with combined hepatocellular-cholangiocellular carcinoma (HC-CC) and immunohistochemically characterized the expression profiles of apomucins. Nondysplastic biliary epithelial cells in the intrahepatic large bile ducts constantly expressed MUC3 apomucin. MUC5/6 and MUC3 apomucin expression was widespread in dysplastic biliary epithelial cells in hepatolithiasis, although the latter was reduced or absent in dysplastic foci. CC extensively expressed MUC1 apomucin and focally expressed MUC2 apomucin. In addition, CC of the hilar type, including those with hepatolithiasis, frequently expressed MUC3 apomucin (68% and 57%, respectively), whereas those of the peripheral type infrequently expressed MUC3 apomucin (10%) (P < .01). MUC5/6 apomucin was more frequently expressed in well-differentiated (89%), compared with poorly differentiated CC (42%) (P < .01). Cholangiocellular elements of combined HC-CC frequently expressed MUC1 apomucin, although they rarely expressed MUC2 and MUC3 apomucin and infrequently expressed MUC5/6 apomucin. The frequent and aberrant expression of "gastric type" MUC5/6 apomucin in biliary epithelial dysplasia, as well as in CC, suggests that biliary epithelial cells gain a gastric apomucin phenotype during carcinogenesis. MUC3 apomucin expression in CC is a marker that suggests that CC arises in the intrahepatic large bile ducts.

Characterization of apomucin expression in intrahepatic cholangiocarcinomas and their precursor lesions: An immunohistochemical study

To date, seven apomucins have been characterized and their expression in malignant and premalignant lesions is under evaluation. In this study, we examined the expression of MUC1, MUC2, MUC3, and MUC5/6 apomucins in cholangiocarcinoma (CC) and biliary epithelial dysplasia. We used 14 liver samples from patients with hepatolithiasis and CC, 11 with hepatolithiasis showing biliary epithelial dysplasia, 31 with CC alone (19 hilar, 10 peripheral, and 2 unclassifiable), and 14 with combined hepatocellular-cholangiocellular carcinoma (HC-CC) and immunohistochemically characterized the expression profiles of apomucins. Nondysplastic biliary epithelial cells in the intrahepatic large bile ducts constantly expressed MUC3 apomucin. MUC5/6 and MUC3 apomucin expression was widespread in dysplastic biliary epithelial cells in hepatolithiasis, although the latter was reduced or absent in dysplastic foci. CC extensively expressed MUC1 apomucin and focally expressed MUC2 apomucin. In addition, CC of the hilar type, including those with hepatolithiasis, frequently expressed MUC3 apomucin (68% and 57%, respectively), whereas those of the peripheral type infrequently expressed MUC3 apomucin (10%) (P < .01). MUC5/6 apomucin was more frequently expressed in well-differentiated (89%), compared with poorly differentiated CC (42%) (P < .01). Cholangiocellular elements of combined HC-CC frequently expressed MUC1 apomucin, although they rarely expressed MUC2 and MUC3 apomucin and infrequently expressed MUC5/6 apomucin. The frequent and aberrant expression of "gastric type" MUC5/6 apomucin in biliary epithelial dysplasia, as well as in CC, suggests that biliary epithelial cells gain a gastric apomucin phenotype during carcinogenesis. MUC3 apomucin expression in CC is a marker that suggests that CC arises in the intrahepatic large bile ducts. (Hepatology 1996 Nov;24(5):1074-8)

BCL‐2 IMMUNOREACTIVITY INCREASES WITH SEVERITY OF CIN: A STUDY OF NORMAL CERVICAL EPITHELIA, CIN, AND CERVICAL CARCINOMA

The presence of the BCL-2 protein, a marker for inhibition of programmed cell death, was studied in a series of routinely processed cervical tissues, consisting of normal endocervical (n=40) and ectocervical epithelium (n=27), squamous metaplastic epithelium (n=30), CIN (cervical intraepithelial neoplasia) lesions (n=32), and cervical carcinomas (n=13). BCL-2 was strongly expressed in the basal cell compartment of normal ectocervical squamous epithelium and in nearly all reserve cells, while in endocervical columnar cells it was moderately expressed. In immature squamous metaplastic epithelium, BCL-2 expression varied. Half of the cases showed only basal cell staining, while the other half showed staining also in suprabasal layers. BCL-2 could be detected in all premalignant lesions, showing a striking increase in the number of positive cells with increasing severity of CIN, in combination with a mild increase in staining intensity. All adenocarcinomas were positive (n=5), while five of eight squamous cell carcinomas expressed BCL-2. Based on these results, it is hypothesized that both the larger number of cells staining with BCL-2 in higher grades of CIN and the increase in staining intensity imply an increasing protection of these neoplastic conditions against programmed cell death. This protection facilitates not only continuing proliferation, but also the induction of genetic instability in dysplastic epithelial cells; it may thus reflect the greater capacity of the more severe CIN lesions to evolve into cervical carcinoma.

BCL-2 immunoreactivity increases with severity of CIN: a study of normal cervical epithelia, CIN, and cervical carcinoma.

The presence of the BCL-2 protein, a marker for inhibition of programmed cell death, was studied in a series of routinely processed cervical tissues, consisting of normal endocervical (n = 40) and ectocervical epithelium (n = 27), squamous metaplastic epithelium (n = 30), CIN (cervical intraepithelial neoplasia) lesions (n = 32), and cervical carcinomas (n = 13). BCL-2 was strongly expressed in the basal cell compartment of normal ectocervical squamous epithelium and in nearly all reserve cells, while in endocervical columnar cells it was moderately expressed. In immature squamous metaplastic epithelium, BCL-2 expression varied. Half of the cases showed only basal cell staining, while the other half showed staining also in suprabasal layers. BCL-2 could be detected in all premalignant lesions, showing a striking increase in the number of positive cells with increasing severity of CIN, in combination with a mild increase in staining intensity. All adenocarcinomas were positive (n = 5), while five of eight squamous cell carcinomas expressed BCL-2. Based on these results, it is hypothesized that both the larger number of cells staining with BCL-2 in higher grades of CIN and the increase in staining intensity imply an increasing protection of these neoplastic conditions against programmed cell death. This protection facilitates not only continuing proliferation, but also the induction of genetic instability in dysplastic epithelial cells; it may thus reflect the greater capacity of the more severe CIN lesions to evolve into cervical carcinoma.

Phototherapeutic Keratectomy in Recurrent Corneal Intraepithelial Dysplasia

The argon-fluoride excimer laser has gained a lot of interest as a treatment modality for superficial ocular abnormalities. We report a case of recurrent corneal intraepithelial dysplasia treated with phototherapeutic keratectomy. Report of a Case. A conjunctival squamous cell carcinoma with corneal involvement developed in the right eye of a 65-year-old woman. Because of a recurrence 4 months after epithelial abrasion, penetrating keratoplasty was performed in April 1988 in another clinic. The margins of the excised cornea were free of dysplastic epithelial cells. However, the neoplasia recurred on the corneal graft after a 3-month interval. Each recurrence was treated with abrasion followed by histologic examination, which time and again showed an intraepithelial dysplasia, stage III. In November 1989, slit-lamp microscopy of the right eye showed a superficial dot-shaped epitheliopathic lesion on the nasal half of the corneal graft, paracentral midstromal scars, and peripheral superficial vascularization ( Figure 1 ). On examination, visual

Analysis of MHC class I and II expression in relation to presence of HPV genotypes in premalignant and malignant cervical lesions.

Cervical intraepithelial neoplasia (CIN) grades I to III lesions (n = 94) and squamous cell carcinomas of the uterine cervix (n = 27) were analysed for MHC class I and II expression and presence of HPV genotypes. MHC class I and II expression was studied by immunohistochemistry and HPV typing was performed by general primer- and type-specific primer mediated PCR (GP/TS PCR). Both techniques were performed on paraffin embedded tissue sections. Results show disturbed MHC class I heavy chain expression in CIN I to CIN III, as well as in cervical carcinomas. Upregulated MHC class II expression on dysplastic epithelial cells was also found in the different CIN groups and carcinomas. Prevalence of HPV genotypes increased with the severity of the lesion, mainly due to the contribution of the HPV types 16 and 18. No correlation could be established between the presence of specific HPV genotypes and any MHC expression pattern in the different CIN groups or cervical carcinomas. In some cases these data were confirmed by RNA in situ hybridisation showing HPV 16 E7 transcripts in the same dysplastic/neoplastic cells from which MHC status was determined. The results indicate that local differences may exist in the type of cellular immune response to HPV induced lesions.

ハムスター口腔癌形成過程における免疫組織化学的研究 口腔癌形成過程におけるケラチンの局在とレクチンの結合性について

The distribution of intracellular keratin and lectin binding were studied in dysplastic lesions and squamous cell carcinomas of buccal pouch and lingual mucosae of the hamster induced by the application of a 0.5% DMBA mineral oil.Comparison was made of the electrophoretic keratin polypeptide patterns of normal buccal pouch epithelia and of squamous cell carcinomas of buccal pouch mucosa. Keratin polypeptides from normal epithelia had a molecular weight (MW) range of about 47, 000 to 76, 000. In tumor extracts, the large polypeptides (above MW 58, 000), found in the normal epithelia, were absent. The majority of small polypeptides below MW 58, 000 were expressed. Antibodies against total keratin extracts from normal buccal pouch epithelia (NAG) and squamous cell carcinomas (CAAG) were raised in rabbits, respectively NAB and CAAB. NAB staining was strong in spinous cells but negative in basal cells, whereas CAAB staining was strong in spinous cells and moderate or weak in basal cells. The dysplastic epithelial cells and squamous cell carcinoma cells except for cancer pearls showed no staining for the NAB, but exhibited weak or moderate CAAB staining.Lectin binding in normal squamous epithelium showed regional distribution patterns of spinous and basal layer types. Dysplastic cells or carcinoma cells displayed a loss of cellular surface and intercellular staining.The present study suggests that the difference of the staining intensities of keratins using NAB and CAAB and the lectin binding among the normal epithelium, dysplasia and squamous cell carcinoma are valuable indicators of the malignant transformation in the oral mucosa of hamsters.

Immunohistochemical detection of epidermal growth factor receptor in laryngeal squamous cell carcinomas.

Laryngeal squamous cell carcinomas from 15 consecutive preoperatively irradiated patients were investigated for the expression of epidermal growth factor receptor (EGF receptor). The study was performed on frozen sections by means of the 5-layer APAAP technique employing an antibody recognizing the extracellular part of the EGF receptor. In sections from 9 of the patients with laryngeal squamous cell carcinoma, normal differentiated epithelia were included. Sections from 6 of these patients, in addition, contained dysplastic epithelia. Expression of EGF receptor-like material was demonstrated in the basal cell layer of normally differentiated laryngeal epithelial and in dysplastic epithelia. Fourteen of the squamous cell carcinomas proved EGF receptor positive. Nearly all cells in the poorly differentiated carcinomas showed positive staining with the antibodies. In moderately to well differentiated carcinomas a reduction in the extent of staining was seen in certain areas. Especially for the epithelial pearls, the staining reaction was localized to the undifferentiated cells in the periphery. This finding corresponds to the staining pattern observed in the basal cell layers of normal epithelial. The present investigation confirms the expression of EGF receptor-like material in normal laryngeal epithelial, dysplastic epithelial and squamous cell carcinoma. The staining pattern was similar to that observed in oral squamous cell carcinomas, predominantly varying inversely with cellular differentiation.

The adenoma-adenocarcinoma sequence in the large bowel: variations on a theme.

Most adenocarcinomas of the colorectum arise in a visible benign precursor lesion, the adenoma, which is a monoclonal proliferation of dysplastic nonmalignant epithelial cells. The resultant adenoma-adenocarcinoma sequence represents the predominant pathogenetic pathway, in contrast to de novo carcinoma. Therefore, the adenoma is a tempting endpoint for chemoprevention trials. The adenoma-adenocarcinoma sequence occurs in diverse clinical settings. In familial adenomatous polyposis (FAP) syndrome, autosomal dominant inheritance of the mutated APC (adenomatous polyposis coli) gene on chromosome 5q21 typically results in thousands of adenomas in the colorectum and in lesser numbers in the proximal small bowel. Adenocarcinoma usually develops in only a few of these adenomas, typically in the left colon and duodenum. In hereditary nonpolyposis colorectal cancer (HNPCC) syndrome, autosomal dominant inheritance of an unidentified gene appears to result in small numbers of adenomas which progress frequently to adenocarcinoma, predominantly in the right or transverse colon. In familial aggregation of colorectal cancer without a recognizable syndrome, cancer and/or adenomas occur in pedigree members. In "sporadic" cancers and adenomas, family history is absent and the tumors are mainly in the left colon. Colorectal adenomas have variable characteristics including size, shape (polypoid vs. flat), villous architecture, and dysplasia. A variety of oncogenes and tumor suppressor genes are altered during progression. Epigenetic factors are important as evidenced by the disappearance of adenomas in FAP patients after ileorectal anastomosis or treatment with the nonsteroidal antiinflammatory drug sulindac. Several variations on the theme of the adenoma-carcinoma sequence are evident. Identification of the inherited and acquired genetic alterations as well as the interacting environmental factors will provide a rational basis for chemoprevention.(ABSTRACT TRUNCATED AT 250 WORDS)

Temporal alterations in cytokeratin expression during experimental oral mucosal carcinogenesis

Precancerous lesions and squamous cell carcinomas (SCCs) were induced in the oral mucosa of outbred male Sprague-Dawley rats by repeated application of the carcinogen 4-nitroquinoline-1-oxide. Temporal alterations in the pattern of cytokeratins expressed by epithelial cells in these developing neoplasms were investigated by means of one- and two-dimensional polyacrylamide gel electrophoresis and by probing electrophoretic blots of these gels with anticytokeratin antibodies. Progressive diminution in the expression of a 58.3 kDa cytokeratin was detected in moderately dysplastic epithelium and subsequent lesions, as was reduced expression of a 53.5 kDa cytokeratin after a stage of severe dysplasia had been induced. Analysis of two-dimensional electrophoretograms indicated an alkaline shift of acidic variants of a 49.0 kDa cytokeratin in moderately dysplastic epithelium; this shift was more pronounced in the induced, severely dysplastic epithelium and SCCs. The latter finding of an alkaline shift in cytokeratins of dysplastic epithelial cells has not been previously reported in preneoplastic lesions.

Routine culturing of normal, dysplastic and malignant human mammary epithelial cells from small tissue samples

We compared the growth and morphology of normal, dysplastic and malignant human mammary epithelial cells (HMEC) in medium containing 5% human serum, a serum-free medium (32) and serum-free medium with a low Ca++ concentration. Tissues were dissociated and epithelial organoids or single cells were seeded onto collagen-coated dishes. The cells grew in serum-containing medium, but growth of fibroblasts was also stimulated. The serum-free medium consistently selected for and stimulated the growth of epithelial cells. There was little advantage in reducing the Ca++ concentration to further increase cell yield. This serum-free primary culture system allows us to routinely produce sufficient numbers of HMEC from small tissue samples for molecular biological investigations. Furthermore, the maintenance of cells in a defined medium can provide a system for evaluating the direct effects of factors on gene expression.

Loss of Leukoregulin Up-regulation of Natural Killer But Not Lymphokine-Activated Killer Lymphocytotoxicity in Human Papillomavirus 16 DNA-Immortalized Cervical Epithelial Cells

The sensitivity of human cervical epithelial cells immortalized by transfection with human papillomavirus type 16 (HPV16) DNA, to lysis by natural killer (NK) and lymphokine-activated killer (LAK) lymphocytes was evaluated at progressive stages of transformation. Both early- (10-20 wk) and late- (greater than 30 wk) passage HPV16-immortalized cells were resistant to NK lymphocyte cytotoxicity but sensitive to LAK lymphocyte cytotoxicity at lymphocyte-to-cervical cell ratios ranging from 1:1 to 50:1 in a 4-hour 51Cr release assay. Treatment of early-passage HPV16 DNA-immortalized cells with 2.5 U/mL of the NK lymphocytotoxicity-sensitizing lymphokine, leukoregulin, for 1 hour induced modest sensitivity to NK cells (P less than .05) but markedly up-regulated LAK sensitivity twofold to threefold. At the later passages, leukoregulin up-regulation of sensitivity to NK was lost but remained to LAK lymphocytotoxicity. Similarly, an HPV16-positive human cervical carcinoma cell line, QGU, was also resistant to NK lymphocytotoxicity and sensitive to LAK lymphocytotoxicity; leukoregulin failed to confer sensitivity to the NK-resistant QGU tumor cells and increased their sensitivity to LAK lymphocytotoxicity 1.5-fold to twofold. Although the HPV-immortalized cervical cells containing integrated HPV16 DNA were not tumorigenic, they mimicked the response of established HPV16-positive cervical carcinoma cells. HPV16-immortalized cervical epithelial cells provide a useful model for the study of cytokine modulation of dysplastic and neoplastic cervical epithelial cell sensitivity to natural lymphocytotoxicity.

Lectin- and immunohistochemical studies on acquired cystic kidney and associated renal cell carcinoma.

Nine specimens of acquired cystic kidney were studied by means of lectin- and immunohistochemistry. The cysts appeared to originate from any part of the nephron, but mostly from the proximal tubule. The cause of multicyst formation is still unclear, but the results of this study suggested that obstruction of the lower nephron might play an important role. Many microscopic carcinomas or dysplastic epithelial cells were observed in the cyst wall. All these carcinomas originated from the proximal tubule, except for one which was of Bellini duct origin and showed papillary growth. The reasons why almost all of the carcinomas originated from the proximal tubule were: 1) the majority of the cysts originated from the proximal tubule, and 2) dysplastic epithelial cells in the cysts originating from the proximal tubules were more frequent in number than those in cysts originating from other parts of the nephron. Histological observation showed that stimulation due to oxalate crystals in the proximal cysts was one of the causes of dysplastic epithelial cell hyperplasia.

Expression of the nuclear oncogene p53 in colon tumours.

The nuclear tumour antigen p53 is expressed by a gene localized on the p-arm of human chromosome 17, a region frequently deleted in colon carcinomas. Using a monoclonal antibody to p53 antigen, immunohistochemical analysis of carcinomas and dysplastic tubular adenomas of the colon has been performed to study the relation between p53 expression and dysplasia or malignancy. With this methods p53 was detectable in 55 per cent of colon carcinomas (n = 29). In 8 per cent of adenomas (n = 74), focal nuclear p53 expression was found in dysplastic epithelial cells. In general, these p53-positive regions of the polyps were histologically indistinguishable from the neighbouring tubuli. Sometimes the p53-positive nuclei were found in a focus of more highly dysplastic epithelium. The results suggest that expression of the p53 gene may be part of the process of malignant transformation of dysplastic colon polyps.