Over-expression of p53 protein in squamous cell carcinoma of the skin

p53 gene mutations have been known to be highly related to the particular stage of transformation in various types of human cancers. This study was conducted to investigate the p53 mutations at the protein level by an immunohistochemical method using anti-p53 antibody, NCL-p53-DO-7. Twenty-five cancer specimens were obtained surgically from patients with squamous cell cancer of the skin at the Korea Cancer Center Hospital. The cancers were classified according to the possible etiology into two groups, burn scar originated and UV-related cancers. Overexpression of p53 protein was detected in ten (40%) out of 25 cases tested: six (40%) of 15 cases associated with burn scar and four (40%) of ten cases related to UV exposure. In all normal skin cells in specimens, p53 protein was not stained at all. The stages and histological grades were evaluated for their relationship with the overexpression of p53 protein. No significant difference was found between the overexpression of p53 protein and the stages or histological grades. These results demonstrating that 40% of skin cancers were positive for p53 overexpression suggest that the alterations of the p53 gene may play a role and the exact role of p53 gene in the development of squamous cell carcinoma of the skin will be studied.

Concentration and distribution of tumor associated antigens TAG-72 and CEA in stomach cancer

We measured the concentration and distribution of tumor associated antigens, TAG-72 and CEA, in stomach cancer by in vitro quantitative autoradiography (IV-QAR). Frozen sections of 33 specimens were incubated with varying concentrations of 125I-labeled CEA-79.1 and B72.3 antibodies specific for carcinoembryonic antigen (CEA) and tumor-associated glycoprotein-72 (TAG-72), respectively. Computer analysis of specific antibody binding gave maximal binding values which were equal to the concentrations of the antigen or epitope. TAG-72 was detected in 25 specimens, at a concentration ranging from 8.4 to 562.9 pmol/g. CEA was detected in 32 of the 33 specimens and its concentration ranged from 8.8 to 525.3 pmol/g. The distribution of TAG-72 by IV-QAR coincided with that of the tumor cells in 41.4% of the pathologic lesions. The distribution of CEA coincided with the tumor cells in 80.5% of pathologic lesions, nearly twice the TAG-72. The concentration of TAG-72 was significantly higher in mucinous adenocarcinoma and mucin containing adenocarcinomas than other types of adenocarcinomas. There was no significant difference in the concentration of CEA among the pathologic types of stomach cancer. In summary, stomach cancer exhibited wide variations in TAG-72 and CEA expression. CEA expression was more frequent and homogeneous than TAG-72.

Adult T-cell leukemia/lymphoma in a Korean--a case report

The clinicopathologic features of a Korean patient with adult T-cell leukemia/lymphoma(ATLL) are presented. A 51-year-old man, who has lived in Korea since birth, had multiple cutaneous nodules and multiple lymphadenopathy for the previous two months. A histopathologic study of the lymph node and skin lesion revealed T-cell non-Hodgkin's lymphoma of pleomorphic type, medium and large cell type. Peripheral blood examination showed leukemic features with 30% of abnormal lymphoid cells. HTLV-I proviral DNA pX region was detected in the DNA from peripheral blood mononuclear cells(PBMC) and the specific gag, pol, and env HTLV-I sequences were detected in the lymph node using polymerase chain reaction technique. Human T-cell leukemia/lymphoma type I(HTLV-I) antibodies were present in the serum. An immunophenotypic study of the lymph node revealed CD4 positive and CD8 negative helper/inducer T cell type surface markers. This case is the acute type, i.e. prototypic ATLL. He was treated with an intensive chemotherapy including cyclophosphamide, etoposide, doxorubicin, vincristine, and prednisone. Despite initial transient improvement, the tumor progressed after three cycles of the regimen and became refractory to further chemotherapy. These clinicopathologic findings, including the immunophenotypic analysis, established with certainty the diagnosis of HTLV-I-induced adult T-cell leukemia/lymphoma.

Potent promoting activity of dimethylitaconate on gastric carcinogenesis induced by N-methylnitrosourea

Dimethylitaconate (DMI) is one of phase II enzyme inducers suggesting a candidate for a tumor inhibitor. We tested the modifying effect of DMI on post-initiation stage of MNU induced gastric carcinogenesis in male Fischer 344 rats. Groups I and II administered N-methylnitrosourea (MNU) at a concentration of 100 ppm in the drinking water for 15 weeks. Group II was treated 0.5% DMI in the drinking water for 37 weeks after the MNU treatment. Groups III and IV were DMI alone and untreated control, respectively. DMI-treated animals showed hyperplastic changes in gastric epithelium and the incidence was 40% in the DMI alone group. MNU combined with DMI significantly increased the adenoma incidence compared with MNU alone group (P < 0.05). The concomitant administration of DMI showed a significant increase of adenocarcinoma incidence, which was 95% (P < 0.005) compared with MNU alone group (11.8%). The replicative DNA synthesis and the labelling index of bromodeoxyuridine, which are the indicators of proliferating activity, were increased in the stomach of DMI-treated rats compared with untreated control (P < 0.001 and P < 0.005, respectively). These results suggested that DMI has potent promoting potential in the post-initiation stage of gastric carcinogenesis of rats and its mechanisms are probably involved in the induction of cell proliferation including replicative DNA synthesis.

Aberrant expression of p53 gene product in malignant melanoma

According to the current concept of carcinogenesis, the alterations of p53 tumor suppressor gene have been the most frequently detected in both human cancer cell lines and cancer tissues freshly isolated. This study was conducted to investigate the p53 gene alteration in malignant melanoma. Nineteen tumor tissues were obtained from 19 patients with malignant melanoma and examined for the expression of p53 protein by immunohistochemical staining with mouse monoclonal anti-p53 antibody, NCL-p53-DO-7. Twelve out of 19 cases (63%) showed positive reactions for p53 protein: 26, 21 and 16% of which had low, intermediate and high reactivity, respectively. p53 alteration more frequently expressed in female (10/12) than male patients (2/7) with malignant melanoma (p < 0.05). The incidence of expression of p53 protein was compared according to the stages and the sites of tissue obtained. The positive rate for p53 protein was not significantly different between the stages. The positive rates for p53 protein were five out of five (100%), one out of two (50%) and six out of twelve (50%) in tissues obtained from the metastatic, lymph node, and primary sites, respectively. The difference in the positive rates, however, is not statistically significant. These results suggest that p53 gene is a frequent target for mutation in the development of malignant melanoma.

Protective effects of potato extracts and 16,16-dimethyl prostaglandin E2 on the induction of hepatic foci by cotreatment of gamma radiation and diethylnitrosamine

We investigated the effect of potato extracts and 16,16-dimethyl prostaglandin E2 (DiPGE2) on the induction of glutathione S-transferase P-positive (GST-P+) altered hepatic foci in newborn Sprague-Dawley rats given single treatment with 60Co gamma irradiation and diethylnitrosamine (DEN) alone or in sequential combination. Intraperitoneal injection of 0.15 mumol/g body weight of DEN 1 hour after gamma radiation significantly increased the frequencies of GST-P+ hepatic foci compared to DEN or gamma radiation alone and DEN injection 1 hour before irradiation (p < 0.001). Potato extract was given at a dose of 2 mg/ml in drinking water for 3 weeks and DiPGE2 given at a dose of 10 micrograms/mouse 30 minutes before irradiation. Potato extracts and DiPGE2 decreased significantly the number (p < 0.001), area (p < 0.001) and Dmax (p < 0.05) of GST-P+ hepatic foci compared to the corresponding control. These results suggest that potato extracts and DiPGE2 have radio-protective potential and further studies for underlying mechanisms will be necessary.

Tumor concentration and distribution of carcinoembryonic antigen measured by in vitro quantitative autoradiography

One of the most critical factors in successful immunoscintigraphy and radioimmunotherapy is the local concentration and distribution of the target antigen. The purpose of this study was to evaluate the concentration and distribution of carcinoembryonic antigen (CEA) in various carcinomas.

METHODS

In vitro quantitative autoradiography was performed in carcinomas of the stomach (32 cases), colon (20 cases), breast (29 cases) and lung (26 cases). Frozen tumor sections were incubated with varying concentrations of 125I-labeled monoclonal antibody (Mab) CEA-79.1 (IgG2a), which is specific for CEA. Digitized autoradiographic images from these sections were compared to adjacent H & E and immunoperoxidase-stained sections. Computer analysis of specific antibody binding quantitated the maximal value (Bmax), which is equal to the concentrations of CEA.

RESULTS

Stomach cancer expressed CEA in 31 cases (97%). All colon cancer specimens exhibited CEA and breast cancer expressed CEA in 24 cases (83%). In adenocarcinoma of the lung, CEA was measured in all specimens. The concentration of CEA did not vary significantly among the pathologic types or among the various degrees of differentiation in each carcinoma. CEA was expressed homogeneously in adenocarcinomas of the colon and lung. However, CEA exhibited a heterogeneous distribution in a significant number of breast cancer (42%) and bronchogenic squamous-cell carcinoma (78%) specimens.

CONCLUSIONS

CEA was expressed in most cases of stomach, colon, breast and lung carcinomas. These carcinomas, however, exhibited wide variation in the concentration and distribution of CEA expression. The concentration and distribution of CEA in a particular tumor type should be considered before undertaking tumor targeting methods.

Development of altered hepatocyte foci by separate and combined treatments with radiation and diethylnitrosamine in neonatal rats

To establish an in vivo radiation carcinogenesis model using glutathione S-transferase placental form positive (GST-P+) hepatic foci, newborn rats were irradiated once by 0.5 Gy and 2 Gy of gamma ray or 0.15 Gy and 0.6 Gy of neutron with or without 0.05% phenobarbital (PB). When the rats were sacrificed at the 12th or 21st week, the incidence of GST-P+ foci induction by radiation alone was very low. The neutron was more sensitive than the gamma ray at week 12 and the reverse phenomenon was observed in the groups at week 21. PB combination showed an increased incidence of GST-P+ foci in gamma ray irradiated groups. The neutron irradiation combined with PB did not show any significant difference compared with the corresponding PB untreated groups. We also investigated the combined effect of diethylnitrosamine (DEN) and 0.75 Gy of gamma ray irradiation. Intraperitoneal injection of 0.15 mumol/g body weight of DEN at 1 hour after gamma ray irradiation showed significantly increased the number and area of GST-P+ foci compared with those of DEN alone or DEN at 1 hour before gamma radiation (P < 0.001). From these data, after more defined experiments, an in vivo radiation carcinogenesis model will be established by radiation alone or a combination of radiation and carcinogens.

Stage IIb cervical carcinoma: MR evaluation of effect of intraarterial chemotherapy

PURPOSE

To evaluate magnetic resonance (MR) imaging in assessment of tumor response after intraarterial chemotherapy (IAC) in cervical carcinoma.

MATERIALS AND METHODS

MR images of 19 patients who underwent IAC because of stage IIb cervical carcinoma were prospectively analyzed and compared with pathologic findings. Three courses of IAC were administered, and MR images were obtained before and after treatment. Extent of reduction of tumor volume determined eligibility for surgery. MR images of 17 patients who were candidates for surgery were correlated with pathologic specimens.

RESULTS

Average reduction in tumor volume was 88.5%. Response to IAC was complete in seven patients, partial in 11, and minor in one. MR imaging findings after IAC correlated well with pathologic findings.

CONCLUSION

MR imaging is useful in assessment of tumor response to IAC and provides criteria for decision making with regard to further radiation or surgical therapy.

Biphasic modifying effect of indole-3-carbinol on diethylnitrosamine-induced preneoplastic glutathione S-transferase placental form-positive liver cell foci in Sprague-Dawley rats

The biphasic modifying effects of indole-3-carbinol (I3C), a naturally occurring constituent of edible cruciferous vegetables, on the development of glutathione S-transferase placental form (GST-P)-positive liver cell foci were investigated by using a medium-term liver bioassay system and a newborn rat hepatocarcinogenesis system. In Experiment 1, a total of 65 male Sprague-Dawley (SD) rats were divided into 5 groups. Animals were given a single intraperitoneal (i.p.) injection of 200 mg/kg diethylnitrosamine (DEN) dissolved in saline for groups 1, 2, and 3 or a single i.p. injection of saline for groups 4 and 5. Group 1 was given the diet containing 0.25% I3C for 2 weeks prior to DEN initiation and then basal diet for 8 weeks. Group 2 was given basal diet for 4 weeks prior to and after DEN initiation and then the diet containing 0.25% I3C for 6 weeks. The rats of group 3 were placed on basal diet during the experiment. Animals of groups 4 and 5 were treated in the same manner as those of groups 1 and 2 except for injection with saline instead of DEN solution. All rats were subjected to two-thirds partial hepatectomy at week 3 and were killed at week 8 after DEN or saline injection. In Experiment 2, a total of 45 female SD rats were dosed with DEN (100 mg/kg, i.p.) or saline at 24 h after birth. After weaning at week 3, the rats were fed diet containing 0.25% I3C for 9 weeks and then were killed at week 12. In Experiment 1, preinitiation exposure to 0.25% I3C caused a significant decrease in numbers of GST-P-positive liver cell foci (P < 0.05), while postinitiation exposure to 0.25% I3C caused significant increases in both number (No./cm2) and area (mm2/cm2) of GST-P-positive liver cell foci (P < 0.05 or 0.01). In Experiment 2, the relative liver weight in the DEN + I3C group was significantly increased (P < 0.001). The numbers and areas of GST-P-positive liver cell foci in the DEN + I3C group were significantly increased as compared to the values of the DEN-alone group (P < 0.001). These results clearly demonstrated that I3C exerts a promoting effect on the postinitiation stage as well as an inhibitory effect on the preinitiation stage in the medium-term liver bioassay.

Alterations of p53 gene in primary gastric cancer tissues

This study was conducted to investigate the p53 gene alterations in 25 surgically-resected gastric adenocarcinomas in the Korea Cancer Center Hospital by polymerase chain reaction single-strand conformation polymorphism analysis (PCR-SSCP) for exons 4-8 and immunohistochemical staining (IHCS) with anti-p53 antibody, DO-7. p53 mutations were detected in nine (36%) out of 25 cancer tissues by PCR-SSCP in exon 4-8: 0,1,1,6 and 1 mutations in exons 4,5,6,7 and 8, respectively. All tissues were also tested by IHCS, and positive staining was observed in 11 cases (44%). A discrepancy of the results between the two methods was observed in four cases. In one which showed positivity by PCR-SSCP a negative reaction by IHCS, the two base deletion was observed in exon 7. On the other hand, in three cases the mutation was detected only in IHCS but not in PCR-SSCP. The exact mechanism by which this discrepancy develops is not clear at present, although it may be due to the mutation of other exons not tested in this study or the relatively low sensitivity of the PCR-SSCP method. The incidence of p53 gene mutations was analysed according to pathologic stage and histological differentiation, but no significant difference was observed between the p53 alterations and these factors. By combined use of PCR-SSCP and IHCS, 48% of the 25 primary gastric cancer were considered to have mutations of the p53 gene. These results suggest that p53 mutation is not an infrequent event in primary gastric cancer and the p53 gene plays an important role in the carcinogenesis process of gastric cancer.

Thymic carcinoid tumor combined with thymoma--neuroendocrine differentiation in thymoma?

A carcinoid tumor of the thymus combined with thymoma in a 62-year-old man is described. The mediastinal tumor had been present for 13 years and was associated with pure red cell aplasia. Carcinoid tumor occupied the central two-thirds of the tumor, consisting of nests and trabeculae of monotonous round cells, which ultrastructurally showed many intracytoplasmic dense-core granules. Typical spindle cell type thymoma surrounded the carcinoid area. Clinico-pathologic findings of this unique case suggested that the carcinoid tumor developed within a preexisting thymoma, illustrating a possibility of neuroendocrine differentiation of thymic epithelial cells.

Cell proliferation not associated with carcinogenesis in rodents and humans

Cell proliferation has often been found to be associated with carcinogenesis in rodents and humans at different stages of the multistage carcinogenesis process. The multistage process includes initiation, promotion, and progression phases. At each phase, increasing the normal level of cell turnover of target cells may enhance carcinogenesis. However, we present evidence that normal levels of cell turnover, or increasing the rate of cell turnover at these different stages, do not necessarily lead to enhanced carcinogenesis. In normal tissues, the length of the cell cycle depends on the age of the host and varies from tissue to tissue. Tissues with normal short cell cycles, such as intestine and bone marrow, do not show a high rate of spontaneous tumors in most species. Cells with higher turnover should be more susceptible to carcinogens at the initiation stage of carcinogenesis if cell proliferation per se causes cancer and if these cells or their progeny survive. Cancer in humans is more often associated with specific etiological factors rather than with the natural proliferative rate of specific tissues. For many tissues of humans and rodents, age-related diseases develop in a progressive, irreversible manner. Often, naturally occurring chronic degenerative and inflammatory changes in a tissue (e.g., kidney, liver, heart, reproductive tract) lead to chronic regeneration of the damaged tissue. Yet, cancer is rarely found in these tissues. In rodent carcinogenesis experiments, chronic toxic lesions, accompanied by increases in normal levels of cell turnover, have sometimes been observed in target organs of nongenotoxic carcinogens. More often, however, organ-specific nongenotoxic toxins are not carcinogens. These toxins include compounds toxic for the liver, kidney, and nasal cavity. In 19 inhalation bioassays conducted by the National Toxicology Program, 5/5 nasal carcinogens and 12/14 nasal noncarcinogens caused nasal lesions usually associated with chronic cell proliferation. Although cell proliferation may contribute to multistage carcinogenesis, cell proliferation is not necessarily a tumor promoter or cocarcinogen.

Alterations in populations of GST-p-immunoreactive single hepatocytes and hepatocellular foci after a single injection of N-nitrosodiethylamine with or without phenobarbital promotion in male F344/NCr rats

The fate of placental glutathione S-transferase (GST-P)-immunoreactive hepatocytes, detectable in livers of rats soon after treatment with N-nitrosodiethylamine (DEN), was examined sequentially with or without phenobarbital (PB) promotion. Group 1 male F344/NCr rats were administered a single i.p. injection of 200 mg DEN per kg body weight at 5 weeks of age. Group 2 rats were given 500 ppm PB in the diet two weeks after the DEN treatment. Groups of six rats were sequentially sacrificed 16, 42, 70, 126 and 238 days after DEN injection. In DEN-treated rats, GST-P immunoreactive hepatocytes (single cells and multiple cell foci) were detectable 16 days after DEN, the total numbers decreasing by day 70 and thereafter rising again. In the early stages the proportion of single immunoreactive hepatocytes was prominent, but with time a gradual increase in small GST-P+ hepatocellular foci and larger foci became evident. Feeding of PB to rats for 16-238 days after a single DEN injection resulted in increases of both single cells and foci, especially foci composed of more than three hepatocytes. The growth response was increasingly pronounced with time. Adenomas or carcinomas were only observed at 126 or 238 days. Numbers of GST-P+ foci far exceeded the numbers of foci visible in hematoxylin-eosin (H & E) stained sections, and a few H & E foci were negative for GST-P. Many GST-P+ foci smaller than ten cells were composed of histologically normal hepatocytes. Almost all GST-P+ foci identifiable in H&E stained sections were larger than ten cells, consisted of clear cells (in both groups) or mixed (clear-eosinophilic) cells in PB-exposed rats, and appeared to be evenly distributed throughout the three zones of the liver. These results suggest that the promotive effect of PB is most evident as an increase in larger hepatocyte populations composed of more than three GST-P+ hepatocytes, rather than in increasing the populations of single GST-P immunoreactive cells. PB may cause clonal expansion of these single GST-P reactive hepatocytes. This study provides evidence for the hypothesis that some of the GST-P reactive hepatocytes are initiated cells.

Effects of carbon tetrachloride, ethanol and acetaldehyde on diethylnitrosamine-induced hepatocarcinogenesis in rats

The modifying action of experimentally induced chronic liver injury on diethylnitrosamine (DEN) hepatocarcinogenesis was investigated using a minimal treatment protocol. A single dose of DEN (15 mg/kg b.w.) was administered as a carcinogen to 1-day-old Sprague-Dawley rats. From 3 weeks of age rats received repeated intraperitoneal injections of carbon tetrachloride (CCl4), or 10% ethanol or 5% acetaldehyde in the drinking water for 9 weeks. Combinations of CCl4 and ethanol or acetaldehyde were also tested. Morphology, immunohistochemistry for glutathione S-transferase-placental form, and incidence and quantity of preneoplastic lesions of the livers were studied. The chronic CCl4 administration produced complete or incomplete liver cirrhosis and exerted a strong promoting effect on the development of neoplastic nodules. Ethanol alone revealed no cirrhogenous or tumor-promoting effect, but enhanced both actions of CCl4. Acetaldehyde increased only the cirrhogenous effect of CCl4.

Pathological responses to preoperative high-dose methotrexate chemotherapy in osteosarcoma--experience in Korea cancer hospital

During the last decade, many clinical investigators at various cancer centers have reported the efficacy of various chemotherapeutic agents in the treatment of osteosarcoma. The regimens using high-dose methotrexate (HDMTX) with citrovorum factor rescue are now considered to be one of the most effective treatments of choice. From December 1989 to May 1991, sixteen patients with Enneking's stage (Enneking et al., 1980) IIB osteosarcoma of the extremities were treated with a high-dose methotrexate regimen. After two cycles of preoperative chemotherapy, an operation was performed; either limb salvage or amputation. The resected lesions were examined pathologically and classified according to Huvos' criteria. On pathological examination, 8 (50%) cases showed Grade IV; 1 (6.25%) Grade III; 4 (25%) Grade II; and 3 (18.75%) Grade I. The types of surgery performed were tumor prosthesis replacement (11); wide resection with or without reconstruction (2); resection and arthrodesis (1); and amputation (2).

Enhanced expression of the c-myc protooncogene in human intracranial meningiomas

We examined the alteration and expression of c-myc protooncogene in 11 human intracranial meningiomas using Southern blot, Northern blot and immunohistochemical techniques. Southern blot showed neither amplification nor rearrangement but Northern blot and immunohistochemical study revealed enhanced expression of the c-myc gene. Immunohistochemically, c-myc product was found in all of the 11 cases and seven of these cases showed an above moderate degree of immunoreaction in semiquantitative analysis. Loss of heterozygosity at IGLC2 locus on chromosome 22 was detected in four of the 8 informative cases. But extent and intensity of immunoreactivity did not correlated with loss of heterozygosity on chromosome 22. These genetic changes may play important roles in the pathogenesis of human intracranial meningioma.

A 4-week feeding study of ground red chilli (Capsicum annuum) in male B6C3F1 mice

The toxicity of red chilli was examined in male B6C3F1 mice fed a commercial meal diet mixed with ground Capsicum annuum (Linn.) at levels of 0.5, 1.0, 2.5, 5.0, 7.5 and 10% by weight. Mice were offered control or test diets ad lib. starting at 6 wk of age. Food consumption was measured daily and individual body weights recorded weekly for the 4-wk feeding period. General health, body weight and food intake were apparently not adversely affected at any level of pepper consumption. Histopathological evaluation revealed slight glycogen depletion and anisocytosis of hepatocytes in the 10% group. However, other organs did not reveal any lesions attributable to the chilli exposure. It appears that red chilli is relatively non-toxic at the doses tested in male B6C3F1 mice.

Progressive atypia in spontaneous and N-nitrosodiethylamine-induced hepatocellular adenomas of C3H/HeNCr mice

The progression of hepatocellular adenomas to carcinomas has been less well documented in mice than in rats. We studied progression of spontaneous and chemically induced hepatocellular adenomas in male C3H/HeNCr mice by image analysis. Spontaneous lesions in 15, 18 and 21 month old untreated male C3H/HeNCr mice and experimentally induced lesions were examined. Experimental group 1 received a single i.p. injection of N-nitrosodiethylamine (DEN) (5 mg/kg body wt) at 15 days of age. Groups 2 and 3 were injected a second time with DEN at 15 or 20 weeks of age (75 mg/kg body wt), with interim sacrifices at 11, 16 and 34 weeks after the second DEN injection. Atypia in adenomas were classified into four grades according to cell size, tinctorial changes, cellular pleomorphism and trabecular pattern. At earlier stages of the neoplastic process (11 or 16 weeks after the second DEN dose), most adenomas were well-differentiated lesions with no atypia or focal grade 1 or 2 atypia. At later stages (34 weeks after the second DEN dose), a large proportion of hepatocellular tumors were classified as adenoma with grade 3 atypia or carcinoma. The proportion of carcinomas in mice treated with a second dose of DEN at 20 weeks of age was significantly higher than in mice treated with a single dose of DEN or in mice given a second dose of DEN at 15 weeks. A positive correlation was found between increase in the size of lesions and increased atypia in both spontaneous and DEN-induced lesions and with age for spontaneous tumors. These results support the hypothesis that mouse hepatocellular adenomas are truly neoplastic lesions in different stages of progression toward malignancy.

Inhibitory effects of biochanin A on benzo(a)pyrene induced carcinogenesis in mice

Biochanin A was studied for its capacity to inhibit benzo(a)pyrene (BP) induced neoplasia in female Swiss Webster mice. To investigate the effect of biochanin A on the initiation step, biochanin A (500 mg/kg) was administered orally 48 hours prior to BP (3 mg/mouse), which was also given orally. This sequence of biochanin A and BP administration was repeated once a week for a total of 4 weeks. At 26 weeks after the last treatment, all the mice were sacrificed. To investigate the effect of biochanin A on the promotion step, a single subcutaneous injection of 0.5 mg of BP was given within 24 hours after birth, and biochanin A (0.125 mg/mouse) was injected intraperitoneally 3 times a week for 6 weeks after weaning. In the initiation protocol, the concomitant administration of biochanin A showed significant inhibition of the mean number of lung tumors (P less than 0.001) and the incidence of carcinoma of the forestomach (P less than 0.02). In the promotion protocol, biochanin A significantly inhibited the incidence (P less than 0.01) and the multiplicity (P less than 0.001) of pulmonary adenoma, compared with the group treated with BP alone. These results suggest that biochanin A inhibitory potential in the initiation, as well as in the promotion step of BP carcinogenesis in female Swiss-Webster mice.

Inhibitory effects of biochanin A on mouse lung tumor induced by benzo(a)pyrene

Biochanin A, an isoflavone compound, is reported to have an inhibitory effect on benzo(a)pyrene [B(a)P] metabolism. We examined the modifying effect of biochanin A on in vivo carcinogenesis using a mouse lung tumor model. As carcinogens, a single subcutaneous injection of 0.5mg of B(a)P was given within 24 hours after birth. The test groups were injected with 0.125mg of biochanin A in 0.1ml DMSO by i.p. 3 times a week for 6 weeks after weaning. All mice were sacrificed at week 9 and the incidence and multiplicity of lung tumors were examined. Concomitant administration of biochanin A showed a significant inhibitory effect on the incidence of tumor-bearing mice (12.5%, P < 0.01), as well as the mean number of tumors (0.13, P < 0.001), compared with the group treated with B(a)P alone in which the incidence was 57.1% and the mean number was 1.0. These results suggest that biochanin A has inhibitory potential on the development of mouse lung tumor induced by B(a)P.

Mucin histochemistry by paradoxical concanavalin A staining in early gastric carcinomas

Phenotypic expression of tumor cells was investigated in 33 early gastric carcinomas by mucin histochemistry using paradoxical concanavalin A staining. This staining method had been developed to differentiate 3 classes of mucins located at various sites of the alimentary tract. Twenty-five (76%) tumors contained mixtures of neutral or acid class II mucin and class III mucin, suggesting the origin of multipotential stem cells. The surface mucous cell expression was more dominant than the pyloric gland or intestinal phenotypes in the well-and poorly differentiated adenocarcinomas. The intestinal properties of the tumor cells were noted not only in the well-differentiated but also in the poorly differentiated or signet ring cell carcinomas, not closely being related to the presence of background intestinal metaplasia. Signet ring cell carcinomas revealed a distinct pattern of mucin histochemistry compared with the other types.

Modifying responses of allyl sulfide, indole-3-carbinol and germanium in a rat multi-organ carcinogenesis model

The modifying potential of allyl sulfide (AS), indole-3-carbinol (I3C) and carboxyethylgermanium sesquioxide (GE) on lesion development was examined in a wide-spectrum initiation model. Groups 1-4 were treated sequentially with diethylnitrosamine (DEN) (100 mg/kg, i.p., single dose), N-methylnitrosourea (MNU) (20 mg/kg, i.p., four doses at days 2, 5, 8 and 11), and N,N-dibutylnitrosamine (DBN) (0.05% in drinking water during weeks 3 and 4). Groups 5-7 received vehicles without carcinogens during the initiation period. Group 8 served as the untreated control. After this initiating procedure, groups 2-7 were administered a diet containing 0.5% AS or I3C and 0.05% GE. All surviving animals were killed 40 weeks after the beginning of the experiment and the target organs were examined. The induction of GST-P+ hepatic foci in rats treated with carcinogens was significantly inhibited by treatment with all three compounds. AS treatment significantly decreased the incidence of hepatic hyperplastic nodules, adenoma of the lung and thyroid, and papillary or nodular hyperplasia of the urinary bladder. Administration of GE also significantly inhibited the development of hepatic nodules and adenoma of the lung and thyroid. However, I3C only inhibited the hyperplastic nodules of the liver. These results demonstrated that this multi-organ initiation model could be useful in confirming organ-specific modification potential and, in addition, the inhibitory effect of AS, I3C and GE on liver, lung, thyroid and urinary bladder carcinogenesis.

Different modifying responses of capsaicin in a wide-spectrum initiation model of F344 rat

The modifying potential of capsaicin (CAP) on lesion development was examined in a rat multiorgan carcinogenesis model. Groups 1 and 2 were treated sequentially with diethylnitrosamine (DEN) (100 mg/kg, ip, single dose at commencement), N-methylnitrosourea (MNU) (20 mg/kg, ip, 4 doses at days 2, 5, 8, and 11), and N,N-dibutylnitrosamine (DBN) (0.05% in drinking water during weeks 3 and 4). Group 3 received vehicles without carcinogens during the initiation period. Group 4 served as the untreated control. After this initiating procedure, Groups 2 and 3 were administered a diet containing 0.01% CAP. All surviving animals were killed 20 weeks after the beginning of the experiment and the target organs examined histopathologically. The induction of GST-P+ hepatic foci in rats treated with carcinogens was significantly inhibited by treatment with CAP. CAP treatment significantly decreased the incidence of adenoma of the lung but increased the incidence of papillary or nodular (PN) hyperplasia of the urinary bladder. The tumor incidence of other organs, such as the kidney and thyroid, was not significantly different from the corresponding controls. These results demonstrated that concurrent treatment with CAP not only can inhibit carcinogenesis but can also enhance it depending on the organ. Thus, this wide-spectrum initiation model could be used to confirm organ-specific modification potential and, in addition, demonstrate different modifying effects of CAP on liver, lung, and bladder carcinogenesis.

Effusion cytology of endodermal sinus tumor of the colon. Report of a case

A three-year-old boy presented with a peritoneal effusion due to an occult endodermal sinus tumor in the ascending colon. Cytologic examination of the ascitic fluid revealed clusters of round plump cells that had large hyperchromatic nuclei, finely stippled chromatin, multiple prominent nucleoli and vacuolated or mucin-containing cytoplasm, features suggesting an adenocarcinoma. The colonic primary was discovered during emergency laparotomy performed due to suspected acute hemoperitoneum. Endodermal sinus tumor should be included in the differential diagnosis when cytologic features reminiscent of adenocarcinoma are encountered in a fluid specimen from a child, especially if there is a history of a gonadal or extragonadal childhood neoplasm.