Chemically induced renal epithelial neoplasia in experimental animals.
Explore the source record for details and available documents.
Adenocarcinoma↗
Biomedical subjects
B F Trump
Publications and source records attributed to B F Trump.
Response of human hepatocyte lysosomes to postmortem anoxia.
We studied the ultrastructure and degradative activity of lysosomes in human livers after somatic death due to cerebral necrosis secondary to shock and/or head trauma. The livers were obtained at autopsy after varying postmortem intervals. Liver ultrastructure was studied in intact liver, in hepatocyte suspension obtained by collagenase perfusion of the liver, and in cultured hepatocytes. Lysosomal protein degradation was measured in a case 24 hours after hepatocyte isolation. By standard ultrastructural criteria, all the livers demonstrated typical reversible manifestations of cell injury. Most hepatocytes demonstrated varying degrees of irreversible cell injury. The ultrastructural alterations were less severe in the isolated hepatocytes in suspensions, and further improvement in morphologic appearance occurred in the cultured monolayers. The most striking alteration in the liver lysosomes was the increase in the numbers of lipofuscin granules (a type of residual body) compared with control liver. The hepatocyte lysosomes constituted an average 3.1% of cytoplasmic volume. There was no correlation between the volume density of lysosomes and either the duration of postmortem anoxia, clinical course, or patient's age. There was no increase in the number of autophagic vacuoles or of secondary lysosomes in postmortem liver. Autophagic vacuoles were more frequently seen in isolated and cultured hepatocytes. Cultured hepatocytes isolated within one hour of clinical death and tested 24 hours later degraded cell proteins at a rate of 1.7% per hour. Protein degradation was stimulated by a physiologic signal (Dibutyryl cAMP, 1 mmol/L) and was inhibited by microtubule poison (vinblastine). We conclude that (1) viable hepatocytes can be isolated even after prolonged postmortem intervals (range, 30 minutes to seven hours), (2) trauma and shock cause an expansion of hepatocyte lysosomes due to accumulation of lipofuscin, and (3) autophagy is blocked by postmortem anoxia and resumes in the recovery phase from anoxic injury in hepatocyte suspensions and in culture.
Cell Survival↗
Mechanisms of cellular injury and death.
Explore the source record for details and available documents.
Animals↗
In vitro binding of aflatoxin B1 and 2-acetylaminofluorene to rat, mouse and human hepatocyte DNA: the relationship of DNA binding to carcinogenicity.
DNA binding levels were determined and compared in cultured hepatocytes from male and female rats as well as other animal species following exposure to aflatoxin B1 (AFB1) or 2-acetylaminofluorene (2-AAF). When human, rat (both male and female) and mouse hepatocytes in primary culture were exposed to 2.0 X 10(-7) M [3H]AFB1 (sp. act. 2.63 microCi/nmol) for 24 h, male rat hepatocytes had the highest degree of [3H]AFB1-DNA binding (203 pmol/mg DNA) and human hepatocytes contained the next highest binding level (42 pmol/mg DNA). Hepatocytes from female rats contained 38 pmol/mg DNA while cultured mouse hepatocytes contained only 1.4 pmol/mg DNA. When the same dose of [3H]AFB1 was administered to the cultured male rat hepatocytes at 24 h, 48 h, 72 h and 1 week after seeding, and incubated for 24 h, the DNA binding levels were 189, 175, 76, 75 pmol/mg DNA respectively. In parallel experiments to the cultured male rat hepatocytes above, the AFB1-DNA binding levels in the cultured female hepatocytes were 42, 41, 37 and 34 pmol/mg DNA respectively. Human, male and female rat hepatocytes in primary culture were exposed to 5.2 X 10(-5) M 2-acetylamino[9-14C]fluorene (sp. act. 0.0094 microCi/nmol) for 24 h. It was determined that male rat hepatocytes contained the highest amount of radioactively labeled 2-AAF bound to their DNA (1.57 nmol/mg DNA), female rat hepatocytes contained 0.62 nmol/mg DNA and human hepatocytes contained 0.29 nmol/mg DNA. Results from our in vitro hepatocyte culture system correlate well with in vivo animal studies dealing with species and sex differences in DNA binding and carcinogenic susceptibility. This indicates that hepatocytes in vitro maintain many of the biological properties necessary for carcinogen response similar to liver cells in vivo. In addition, comparison of genotoxic effect in cultured hepatocytes from animals as well as humans may be useful in evaluating carcinogenic potential of xenobiotics in human liver.
2-Acetylaminofluorene↗
Resistance to serum-induced terminal differentiation in normal human tracheobronchial epithelial cells after in vivo exposure to 7,12-dimethylbenz[a]anthracene.
Normal human tracheobronchial epithelial cells (NHTBECs) from nine donors were used to repopulate de-epithelialized rat tracheas. After transplantation into nude mice and treatment with 7,12-dimethylbenz[a]anthracene (DMBA), the transplants were removed at 3, 4, 5 and 6 months. Epithelial cells from DMBA-treated tracheas were subculturable. Epithelial cells from most untreated tracheas were not subculturable. After treatment with 0.5, 1, 2, 4, 6 and 8% serum, cells exhibited increased subculturability after in vivo treatment with DMBA, did not terminally differentiate and were still proliferating even in medium containing 8% serum. Karyotypes from these cells showed considerable aneuploidy. Although these cells did not survive for more than 10 subcultures (42 weeks), this was considerably longer than the survival of control cells. Because of their longer survival, resistance to serum-induced terminal differentiation and chromosome alterations, they were considered to be phenotypically altered or partially transformed cells produced by in vivo treatment of human cells with a chemical carcinogen.
9,10-Dimethyl-1,2-benzanthracene↗
Recent laboratory studies in chemical carcinogenesis. Discussion paper.
Explore the source record for details and available documents.
Animals↗
Extracellular Ca2+-dependent elevation in cytosolic Ca2+ potentiates HgCl2-induced renal proximal tubular cell damage.
While normal fluctuations of cytosolic Ca2+ ([Ca2+]i) occur physiologically, the deregulation of cellular Ca2+ homeostasis leads to cellular injury. The contribution of [Ca2+]i to the process of cellular damage was assessed in a model system where HgCl2 was used to induce plasma membrane damage in renal tubular cells. In the presence of 1.37 mM extracellular Ca2+, HgCl2 (10-50 microM) induced a slow, dose-dependent, 4-6 fold increase in [Ca2+]i (as measured by Quin 2) by 10 min of exposure, which could be abolished by prior incubation of the cells with dithiothreitol. Correlates of cellular injury, i.e., decrease in cell viability, change in cellular morphology, such as bleb formation, membrane distortion and mitochondrial swelling, were induced after HgCl2 addition. The rate and dose-responses of these changes were similar to that of [Ca]i elevation. When cells were exposed to HgCl2 in the absence of added extracellular Ca2+, there was no increase in [Ca2+]i and both the rate and extent of cell damage were reduced. When Ca2+ was readded to the extracellular medium after HgCl2, there was a rapid elevation of [Ca2+]i, increased cell killing and bleb formation. The observed correlation between [Ca2+]i elevation, decreased cell viability and morphological aberrations in terms of (i) dose-dependency for HgCl2, (ii) requirement for high extracellular Ca2+, and (iii) rate of change, suggests that HgCl2-induced renal cell damage involves the entry of Ca2+ from the extracellular milieu which potentiates the progression of cellular injury.
Animals↗
Localization of keratin mRNA in human tracheobronchial epithelium and bronchogenic carcinomas by in situ hybridization.
An in situ hybridization technique was applied to detect expression of keratin mRNAs in xenotransplanted human tracheobronchial epithelium and lung carcinomas. Tissues from eight tracheas repopulated with cells from five different noncancerous donors and 15 squamous cell carcinomas were used. Using a K6 (56 kd) human keratin cDNA (KA-1) and a K14 (50 kd) cDNA (KB-2) as probes, radiolabeled by nick-translation with 3H-dATP/TTP, the specificity and significant differences in the levels of silver grains on various epithelial lesions in formalin-fixed, paraffin-embedded tissue sections were demonstrated. In situ hybridization with either KA-1 or KB-2 probe showed similar localization of silver grains in all histologic types in consecutive tissue sections. In xenotransplanted tracheobronchial epithelia, very few grains were seen over cells of simple, pseudostratified, or stratified epithelia two to three cell layers thick. Nonkeratinizing stratified hyperplastic epithelia of more than three cell layers showed uniform localization of numerous grains throughout the lesions. In contrast, epidermoid metaplasias exhibited a dense and localized pattern of grains on the basal and parabasal cell layers with a decrease in grain density toward the surface layers. Carcinoma cells from bronchogenic squamous cell carcinomas showed a higher density and more uniform localization of grains. Well-differentiated carcinoma cells contained more keratin mRNAs than moderately to poorly differentiated carcinoma cells. This evidence obtained with the KA-1 and KB-2 probes demonstrates the different localization patterns of keratin mRNAs in different epithelial lesions. In addition, the levels of mRNA expressed show a positive correlation with the degree of squamous differentiation. It was of particular interest that an ordered program of keratin mRNA expression proportional to the level of cellular differentiation was observed in epidermoid metaplasias. Both of these probes serve as keratinization markers of human tracheobronchial epithelial lesions.
Animals↗
HgCl2-induced changes in cytosolic Ca2+ of cultured rabbit renal tubular cells.
Fura 2 was used to measure changes in cytosolic [Ca2+] ([Ca2+]i) in cultured rabbit kidney proximal tubule cells exposed to HgCl2. Treatment with 2.5-10 microM HgCl2 resulted in an extracellular [Ca2+] ([Ca2+]e)-independent 2- to 12-fold increase in [Ca2+]i above resting levels of about 100 nM. Treatment with 25-100 microM HgCl2 caused a rapid [Ca2+]e-independent 10- to 12-fold increase in [Ca2+]i within 1 min followed by a recovery to about 2-fold steady state by 3 min. With 25-100 microM HgCl2, both magnitude and rate of Ca2+ increase were similar, but recovery was greater with increasing doses. A slower, secondary increase in [Ca2+]i followed which varied with HgCl2 concentration and required [Ca2+]e. The first increase in [Ca2+]i represents release from intracellular pools. Calcium channel blockers, calmodulin inhibitors, and mitochondrial inhibitors do not alter the patterns of [Ca2+]i changes due to HgCl2. The recovery response with higher HgCl2 concentrations appears to be triggered by Hg2+ and not by the increased [Ca2+]i. Sulfhydryl modifiers N-ethylmaleimide, PCMB and PCMBS produced [Ca2+]e-independent [Ca2+]i increases similar to those induced by low HgCl2 concentrations. Cell killing with HgCl2 was about 50% greater with normal [Ca2+]e than with low [Ca2+]e, suggesting that [Ca2+]e influx is important in accelerating injury leading to cell death.
Animals↗
Cell and species differences in metabolic activation of chemical carcinogens.
Metabolic activation and DNA binding of aflatoxin B1 (AFB1), N-nitrosodimethylamine (DMN) and benzo[a]pyrene (B[a]P) were compared in human, rat and mouse hepatocytes and human pulmonary alveolar macrophages (PAM). The degree of carcinogen activation by hepatocytes and PAM was measured by cell-mediated mutagenesis assays in which co-cultivated Chinese hamster V79 cells were used to monitor mutagenic metabolites. Hepatocytes from human, mouse and rat metabolized DMN and released the active metabolites to induce either ouabain- or 6-thioguanine-resistant mutation. The mutation frequencies mediated by hepatocytes of the 3 animal species were approximately 3-9 mutants/10(5) survivors at a concentration of 0.2 mM DMN. The variations of radioactivity bound to liver cell DNA were relatively small in cultured mouse, rat, and human hepatocytes exposed to 14C label DMN (0.5 mM) and the binding values were in a range of 6-12 X 10(3) pmoles/mg DNA. However, rat hepatocytes were at least 10-fold more effective than either human or mouse hepatocytes in generating mutagenic metabolites of AFB1 and also had a much higher AFB1 metabolite DNA-binding value. The AFB1 DNA-binding levels were 4.1, 12-27 (range), 120 pmoles/mg DNA respectively in mouse, human, and rat liver cells following AFB1 (3.3 microM) exposure for 20 h. Hepatocytes from the 3 animal species were unable to mediate mutation in the presence of 4 microM B[a]P; PAM activated B[a]P and effectively mediated mutation in the co-cultivated V79 cells. In contrast to results with hepatocytes, PAM failed to generate enough mutagenic metabolites of AFB1 (3.3 microM) and the mediation of mutations was seen only at very high concentration of DMN (80 mM). The genotoxic effects of the 3 carcinogens on hepatocytes from different species in vitro were in agreement with the in vivo animal experiments in that mice are relatively resistant to AFB1 carcinogenesis whereas rats are sensitive; B[a]P is not effective as a complete liver carcinogen in adult rat and mouse whereas DMN induces liver cancer.
Aflatoxin B1↗
Comparison of metabolic activation of carcinogens in human, rat, and hamster hepatocytes.
The activities to activate and detoxify procarcinogens were compared in intact hepatocytes from humans, Sprague-Dawley rats and Syrian golden hamsters. Mutagenic metabolites that were released from the isolated hepatocytes were detected by mutation induction in co-cultivated Salmonella typhimurium TA98. Hepatocytes from the 3 animal species all activated aflatoxin B1 (AFB1), acetylaminofluorene (AAF) and aminofluorene (AF) and released active metabolites to induce mutation in the indicator S. typhimurium T98. Hamster hepatocytes were more effective than were human and rat hepatocytes to mediate mutation of Salmonella TA98 by AFB1, AAF and AF. Hepatocytes of human and rat failed to mediate mutation by 1-aminopyrene (1-AP). Indeed, at low concentration of 1-AP and 1-nitropyrene (1-NP), the presence of the hepatocytes decreased the number of TA98 revertants. Only at higher concentrations of 1-aminopyrene and 1-nitropyrene did hamster hepatocytes increase mutation frequencies of indicator cells over the control groups. It seems that hepatocytes, particularly human hepatocytes, are better able to absorb and detoxify 1-AP and 1-NP than to activate them.
2-Acetylaminofluorene↗
Ion regulation, cell injury and carcinogenesis.
Explore the source record for details and available documents.
Calcium↗
Occupational hydrocarbon exposure and renal histopathology.
A blinded, retrospective study of histological sections from ten hydrocarbon-exposed and twenty unexposed nephrectomized renal cell carcinoma cases was conducted to evaluate the histopathologic features present in the apparently normal kidney parenchyma removed with the tumor. Tissue sections from each of the thirty cases were independently reviewed by three consulting pathologists and scored using well defined criteria. Occupational hydrocarbon exposure indices were developed by a team of industrial hygienists and applied to the detailed occupational history of each exposed case. A positive correlation was observed between age and the total renal pathology score (rs = .40, p less than .03). No correlation was found between indices of occupational hydrocarbon exposure and renal pathology scores among exposed cases. No significant differences in renal pathology scores were noted when exposed cases were matched to unexposed cases by age, sex, and race. These results are limited by the inclusion of only cases with historical hydrocarbon exposures. It is recommended that a follow-up study be conducted, utilizing sensitive quantitative methods, to define what, if any, cytopathologic renal effects occur in conjunction with current occupational exposures to hydrocarbons.
Adult↗
Immunohistochemistry of the cytoskeleton of human prostatic epithelium. Evidence for disturbed organization in neoplasia.
An indirect immunoperoxidase technique was used to evaluate keratin, actin, tubulin, and calmodulin immunoreactivity in histologic sections of normal, hyperplastic, and neoplastic human prostate. Polyclonal as well as monoclonal keratin antibodies produced equivalent and intense staining of normal epithelium. The immunoreactivity of normal prostate with keratin antibodies was more pronounced than with antibodies to the other components of the cytoskeleton. Variation in staining for components of the cytoskeleton was minimal. The same findings applied to hyperplastic prostate. The immunoreactivity of prostate tumors with antibodies to these cytoskeletal proteins differed markedly from normal prostate. Prostatic carcinomas showed reduced keratin immunoreactivity with a panepithelial antibody, but unaltered or enhanced immunoreactivity with tubulin, actin, and calmodulin antibodies. Many tumors were unreactive with a monoclonal keratin antibody that was strongly reactive with tissues that contained cytokeratin 18 (45-kd) and which intensely stained normal and hyperplastic prostate. In addition, prostate carcinomas often yielded heterogeneous patterns of staining with actin, tubulin, and calmodulin antibodies in contrast to normal and hyperplastic prostate, which showed uniform staining. The results suggest that a disturbance in the organization of the cytoskeleton may accompany neoplastic transformation of human prostate.
Actins↗
Pathophysiology of acute renal failure following living Escherichia coli injection in rats: high-energy metabolism and renal functions.
The energy metabolism of kidney and renal function were studied in rats following an IV injection of living Escherichia coli. Energy charge (ATP + 0.5 ADP/ATP + ADP + AMP) decreased throughout the period studied. Total and ouabain-sensitive Na-K ATPase activity of renal cortex homogenate decreased markedly at 3 hr followed by gradual recovery. Polyulia was seen at 3 and 6 hr followed by oliguria at 12 hr after E. coli injection. PSP excretion test showed a marked decrease throughout the time course. In contrast, creatinine clearance decreased only at 12 hr. From these results, it was clarified that the renal insufficiency following bacteremia occurs in two different stages; the early stage with a high urinary output accompanied by decreased Na-K ATPase activity suggesting deterioration of proximal tubular functions and the late stage with oliguria in which glomerular filtration is severely depressed. In both stages, renal energy metabolism is markedly disturbed.
Acute Kidney Injury↗
Epidermoid metaplasias of xenotransplanted human tracheobronchial epithelium.
Repopulation of rat tracheas of human tracheobronchial epithelial cells obtained from intermediate autopsies was achieved by introducing into de-epithelialized rat tracheas either pieces of donor tissue containing respiratory mucosa or epithelial cells produced by an in vitro amplification of these cells. After tracheas were sealed, and transplanted into the subcutaneous tissues of nude mice, a newly formed epithelium migrated over the denuded luminal surface. During this process, regenerative epidermoid metaplasias, consisting of the growth of thin stratified epithelium with keratinization but without atypia was observed. Four weeks after xenotransplantation, most of the luminal surface was covered by columnar epithelium with occasional patches of epidermoid metaplasia. When this epithelium was exposed to 7,12-dimethylbenzo[a]anthracene (DMBA) a thick epidermoid metaplasia with mild to moderate atypia was observed. This type of epithelium is seen one to three months after insertion of the DMBA-containing pellets into the tracheal lumen. Immunohistochemical staining with antikeratin monoclonal antibodies AE1 and AE3 revealed increased immunostaining in both regenerative and DMBA-induced metaplasias compared with that of untreated normal mucociliary epithelium. Although no differences between the two types of metaplasias were detected with AE1 and AE3, the use of involucrin immunostain showed important differences. Normal respiratory epithelium did not contain involucrin, but this protein was seen in the surface layer of regenerative epidermoid metaplasias. In DMBA-induced metaplasias, involucrin was found not only in the superficial cells but was also present in numerous suprabasal cells. The hyperplastic nature of these carcinogen-induced lesions, together with the presence of cellular atypia and an altered involucrin distribution pattern, suggest a preneoplastic state.
9,10-Dimethyl-1,2-benzanthracene↗
The effect of gentamicin on human renal proximal tubular cells.
Human renal proximal tubular cells were exposed to gentamicin (0, 0.1, 0.5, 1.0, 5.0, 10.0 mg/ml medium) for 3, 7, 10, and 14 days. Cells were counted and cell viability was estimated by lactate dehydrogenase release. In addition, brush border-associated (gamma-glutamyltransferase) and lysosomal (acid phosphatase, N-acetyl-beta-glucosaminidase, and sphingomyelinase) enzyme activities were measured (0.01, 1.0, 3.3 mg/ml gentamicin for 3, 7, 10 and 14 days). The number of cells did not change significantly after gentamicin treatment. Cell viability, however, significantly decreased after 3 and 7 days exposure to 5 and 10 mg/ml gentamicin. Total lactate dehydrogenase activity was significantly decreased at 7, 10, and 14 days exposure to gentamicin greater than or equal to 5.0 mg/ml. gamma-Glutamyltransferase, acid phosphatase, and sphingomyelinase were decreased at 3, 7, and 10 days exposure to gentamicin greater than or equal to 1.0 mg/ml. Continued exposure to gentamicin less than or equal to 1.0 mg/ml appeared to have little or no effect on the activity of these enzymes at 14 days. N-Acetyl-beta-glucosaminidase activity, in contrast, was elevated (120-140% control) in the gentamicin-treated (greater than or equal to 1.0 mg/ml) groups at all time periods studied. Thus, gentamicin exposure resulted in changes in some of the enzyme activities in human renal proximal tubular cell cultures, but longer exposure (14 days) to gentamicin (less than or equal to 1.0 mg/ml) resulted in a return to control levels of some activities.
Acetylglucosaminidase↗
Immunocytochemical evaluation of human esophageal neoplasms and preneoplastic lesions for beta-chorionic gonadotropin, placental lactogen, alpha-fetoprotein, carcinoembryonic antigen, and nonspecific cross-reacting antigen.
Human esophageal neoplasms were studied in comparison to normal, uninvolved, and preneoplastic human esophageal epithelium for the presence of human chorionic gonadotropin (HCG), human placental lactogen (HPL), alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), and nonspecific cross-reacting antigen (NCA) using the unlabeled antibody peroxidase-antiperoxidase technique. HCG immunoreactivity was identified in 10 of 33 squamous cell carcinomas (33%), in 1 of 6 adenocarcinomas (17%), and 1 of 6 preneoplastic esophageal lesions (17%); while 9 of 33 squamous cell carcinomas (33%) and 1 of 6 adenocarcinomas (17%) contained immunoreactive AFP. Immunoreactive HPL was detected in 6 of 33 squamous cell carcinomas (20%), but in none of the adenocarcinomas. Neither AFP nor HPL immunoreactivity was identified in the 6 hyperplastic lesions which were studied. When stained with an antiserum that was able to detect both CEA and NCA, 27 of 33 squamous cell tumors (82%) and 6 of 6 adenocarcinomas (100%) showed positive immunostaining reactions. Of these, 8 squamous cell carcinomas and 1 adenocarcinoma were subsequently shown to contain only NCA immunoreactivity, while 19 squamous cell carcinomas and 5 adenocarcinomas contained both NCA and CEA immunoreactivity. NCA immunoreactivity alone was identified in 3 of 6 preneoplastic lesions and NCA and CEA immunoreactivity in 1 of 6 preneoplastic lesions. None of the markers was detected in 8 specimens of normal esophageal epithelium which were studied as controls, nor in 6 specimens of uninvolved esophageal epithelium obtained from patients with esophageal cancer. Most tumors expressed 2 or 3 markers, and some tumors were identified which expressed up to 4 of the 5 markers investigated. Only 3 tumors failed to express any of the markers studied. No association was found between the degree of tumor differentiation and presence or absence of HCG immunoreactivity. However, HPL immunoreactivity was more common in poorly differentiated squamous cell carcinomas. In contrast, immunoreactive AFP was more common in well-differentiated squamous cell carcinomas than in other tumor types. Similarly, both CEA and NCA were more frequently expressed in well-differentiated squamous cell carcinomas, adenosquamous carcinomas, and adenocarcinomas than in less differentiated tumors. Our results suggest that HCG, HPL, AFP, CEA, and NCA are tumor-associated antigens in esophageal cancer. Therefore, they could be of value in screening tests for esophageal neoplasms and could be useful in subclassification of esophageal neoplasms.
Antigens, Neoplasm↗