Immunogenic cell death by oncolytic herpes simplex virus type 1 in squamous cell carcinoma cells

Molecules essential for the induction of immunogenic cell death (ICD) are called damage-associated molecular patterns (DAMPs). The effects of oncolytic herpes simplex virus type 1 (HSV-1) on the production of DAMPs were examined in squamous cell carcinoma (SCC) cells. The cytopathic effects of HSV-1 RH2 were observed in mouse SCCVII cells infected at a high multiplicity of infection (MOI), and the amounts of viable cells were decreased. After being infected with RH2, ATP and high mobility group box 1 (HMGB1) were released extracellulary, while calreticulin (CRT) translocated to the cell membrane. A flow-cytometric analysis revealed an increase in the number of annexin-V and propidium iodide (PI)-stained cells; and the amount of cleaved poly (ADP-ribose) polymerase (PARP) was increased. The killing effect of RH2 was reduced by pan-caspase inhibitor z-VAD-fmk and the caspase-1 inhibitor z-YVAD-fmk, suggesting the involvement of apoptosis and pyroptosis. In C3H mice bearing synergic SCCVII tumors, the growth of tumors injected with the supernatant of RH2-infected cells was less than that of tumors injected with phosphate-buffered saline (PBS). These results indicate that oncolytic HSV-1 RH2 produces DAMPs from SCC cells to induce cell death. This may contribute to the enhancement of tumor immunity by oncolytic HSV-1.

Enhancement of systemic tumor immunity for squamous cell carcinoma cells by an oncolytic herpes simplex virus

RH2 is a neurovirulent γ134.5 gene-deficient herpes simplex virus type 1 (HSV-1) with a lytic ability in human squamous cell carcinoma (SCC) cells; it is related to spontaneously occurring HSV-1 mutant HF10. The effect of RH2 on SCC was examined using a syngeneic C3H mouse model. After infection of mouse SCCVII cells with RH2, cell viability was decreased at first, but recovered by prolonged culture, indicating the limited replication of RH2. The antitumor ability of RH2 was examined using a bilateral SCCVII tumor model. The growth of the RH2-injected tumors was suppressed compared with that of phosphate-buffered saline-injected tumors. Moreover, the growth of contralateral tumor of RH2-treated mice was also suppressed significantly. The splenocytes of C3H mice treated with RH2 lysed more SCCVII cells than NFSaY83 cells and YAC-1 cells. The cytotoxicity of the splenocytes on SCCVII cells was significantly greater than that of splenocytes from tumor-bearing mice. Removal of CD8(+) T cells from splenocytes decreased their cell killing activity remarkably. The antitumor effect of RH2 on SCCVII xenografts in nude mice was not demonstrated. These results indicate that RH2 exhibited a suppressive effect on mouse SCC, even if the replication of RH2 was limited. This is ascribed to the ability of RH2 to enhance existing tumor-specific cytotoxic T lymphocyte activity.

ESE-1 inhibits the invasion of oral squamous cell carcinoma in conjunction with MMP-9 suppression

OBJECTIVES

Matrix metalloproteinases (MMPs) regulated by ets transcription factors facilitate carcinoma cell invasion. An ets family member, ESE-1, is expressed specifically in epithelial tissues, but its association with MMPs is obscure. In this study, we investigated whether ESE-1 regulates invasion of oral squamous cell carcinoma (SCC) via transcriptional activity of MMP-9.

METHODS

HSC-3 and KB were used as human oral SCC lines. The expression of ESE-1 and MMP-9 was detected by in situ hybridization and immunohistochemistry. Invasion assay, gelatin zymography and Northern blotting were used to detect the invasion activity, the gelatinolytic activity and the expression of MMP-9 in the ESE-1 transfectants. Luciferase assays and mutation analysis were used for the transcriptional analysis of MMP-9 promoter region by ESE-1.

RESULTS

ESE-1 was expressed in the intermediate layer but not in the invasive area, in which MMP-9 was expressed, in the oral SCC tissues. ESE-1 suppressed invasion activity and 92 kDa gelatinolytic activity in HSC-3 as a result of transfection. ESE-1 regulates MMP-9 expression in a negative manner and the ets binding site on the MMP-9 promoter contributed to suppression by ESE-1.

CONCLUSIONS

These findings indicate that ESE-1 negatively regulates the invasion of oral SCC via transcriptional suppression of MMP-9.

Induction of endonuclease G-mediated apopotosis in human oral squamous cell carcinoma cells by protein kinase C inhibitor safingol

PKC inhibitor safingol suppressed the growth of human oral squamous cell carcinoma (SCC) cells significantly at concentrations that inhibit PKC isoforms. Safingol inhibited the translocation of PKC following treatment with 12-o-tetradecanoylphorbol 13-acetate (TPA) in PKC alpha-EGFP-transfected cells, but not in PKC beta-EGFP- transfected cells, indicating selective inhibition for PKC alpha in oral SCC cells. Flow cytometric analysis and DNA analysis by agarose gel electrophoresis revealed an increase in the proportion of sub-G(1) cells and DNA fragmentation in safingol-treated cells. Mitochondrial membrane potential was decreased, and cytochrome c was released from mitochondria. However, the safingol-induced cell death was not accompanied by activation of caspase 3 and cleavage of poly (ADP-ribose) polymerase (PARP). The broad-spectrum caspase inhibitor BD-fmk failed to prevent safingol-induced cell death. Another apoptogenic factor endonuclease G, but not apoptosis-inducing factor (AIF), was also released from mitochondria and translocated to the nucleus. These results suggest that PKC alpha inhibitor safingol induces an endonuclease G- mediated apoptosis in a caspase-independent manner.

Enhancement of antitumor activity of herpes simplex virus gamma(1)34.5-deficient mutant for oral squamous cell carcinoma cells by hexamethylene bisacetamide

Current oncolytic viruses exert only limited antitumor activity on their own. There is a need to increase their oncolytic capability. We evaluated the effect of a differentiating reagent, hexamethylene bisacetamide (HMBA), on the antitumor activity of a gamma(1)34.5-deficient herpes simplex virus type 1 (HSV-1) R849 for human oral squamous cell carcinoma (SCC) cells. Hexamethylene bisacetamide increased the viral yield, especially at a low input multiplicity of infection (MOI), and the transcription of immediate early genes of HSV-1. Hexamethylene bisacetamide treatment promoted the cytopathic effect of R849 and increased the proportion of dead cells. Hexamethylene bisacetamide produced more apoptotic cells in R849-infected cells as compared with parental HSV-1(F)-infected cells. The growth of oral SCC xenografts in nude mice was markedly suppressed by treatment with R849 in combination with HMBA, and the survival of the co-treated animals was significantly prolonged as compared with that of animals treated with R849 only. Herpes simplex virus type 1 mRNA was expressed in tumors and trigeminal neurons, but not in brain, lung, liver, and kidney. These results indicate that HMBA enhances the antitumor activity of R849 through the expression of immediate early genes without increasing its toxicity. Hexamethylene bisacetamide can be used as an enhancing agent for oncolytic therapy with HSV-1 mutants.

A modified repositioning system for segmental resection of the mandible

Mandibular reconstruction is required after segmental resection of the mandible. Several techniques have been proposed but have several drawbacks. A modified system (based on Leibinger's titanium-positioning system) that can reposition the residual mandible easily and accurately without interfering with the reconstructive procedure was developed. This system has been used successfully in more than 10 patients, with no complications.

Phase II study of a novel oral formation of 5-fluorouracil in combination with low-dose cisplatin as preoperative chemotherapy of oral squamous cell carcinoma

TS-1 is a novel oral 5-fluorouracil containing tegaful (prodrug of 5-FU) and two biochemical modulators. These modulators feature effect-enhancing and adverse reaction-reducing activity. We investigated the histological response and toxicities of combination chemotherapy with TS- 1 and low-dose cisplatin and evaluated its usefulness as preoperative chemotherapy Forty-four newly diagnosed patients with stage Il-IV oral squamous cell carcinoma were enrolled in this study from February 2002 to April 2004. Patients were administered TS-1 80 mg/m2/day (days 1-14) and cisplatin 5 mg/m2/day (days 1-5 and 8-12) followed by radical surgery within 2 weeks. The histopathological effect of chemotherapy, which was a surrogate endpoint of this trial, was evaluated with surgical or biopsy specimens. The rate of histological antitumor effect was as follows: complete response (CR) 36.4%, partial response (PR) 25.0%, minor response (MR) 18.1% and no change (NC) 20.5%. The rate of histological response (CR + PR) was 61.4%. The CR rate of effective cases was 59.3%. The main toxicities occurred in bone marrow and the digestive tract. The incidence of severe toxicity such as grade 3 or 4 was 4.5% in anemia, 9% in leukocytopenia, 11.4% in neutropenia, 4.5% in thrombocytopenia and 2.3% in anorexia, diarrhea and urticaria. Most patients showed no toxicity or mild toxicities. TS- 1 with low-dose cisplatin has highly effective antitumor activity and mild toxicities. In particular, the CR rate was very high. It is suggested that this regimen is suitable for neoadjuvant chemotherapy. We expect that this chemotherapy will contribute to avoidance of surgery for small tumors (stages I and II) and will enable function-preserving surgery for advanced tumors.

Induction of tumour differentiation and apoptosis and LeY antigen expression in treatment with differentiation-inducing agent, vesnarinone, of a patient with salivary adenoid cystic carcinoma

A patient with locally-advanced submandibular adenoid cystic carcinoma with poorly differentiated solid type, was treated with differentiation-inducing agent, vesnarinone, per os at a dose of 60 mg/day daily for 8 weeks. The vesnarinone administration caused marked regression of the tumour. In addition to conversion into the well-differentiated tubular type from the poorly differentiated solid type, the induction of apoptosis and LeY antigen was observed in the treated tumour. These findings indicate that vesnarinone might be a useful therapeutic agent for treatment of salivary cancer. Since we found the new expression of LeY antigen in the well-differentiated tubular lesion in the salivary adenoid cystic carcinoma treated with vesnarinone, we examined the LeY antigen expression in relation to tumour differentiation in five cases of salivary adenoid cystic carcinoma. Consequently, tissue sections from all of the adenoid cystic carcinoma examined showed no positive LeY staining, except for some areas in the tumour lesion with the tubular pattern including the histologically normal-appearing tissue adjacent to the tumour tissue. These findings suggest that there is the intimate relationship between the LeY antigen expression and tumour differentiation in human salivary adenoid cystic carcinoma.

Effect of Ca2+-dependent cell death on the release of herpes simplex virus

The effect of a variety of cell death-inducing reagents on the release of herpes simplex virus type 1 (HSV-1) was examined. Ionomycin was found to increase the release of HSV-1, whereas no significant increase was observed by the treatment with TNF-alpha, anti-Fas antibody, C2-ceramide, sphingosine, H-7, tyrphostin and camptothecin. Ionomycin induced an immediate early peak and a subsequent long-lasting elevation of intracellular Ca(2+) concentration ([Ca(2+)]i). In the absence of extracellular Ca(2+), ionomycin neither elevated [Ca(2+)]i nor increased the release of HSV-1 from the infected cells, indicating that Ca(2+) influx play an important role in the release of HSV-1. Studies with trypan blue and annexin V staining revealed that the ionomycin-induced alteration of [Ca(2+)]i was accompanied by cell death of the infected cells. Disintegration of cell membrane, cytoplasmic vacuole formation and the leakage of virus particles from the cell surface were observed by electron microscopy. These results indicate that Ca(2+)-dependent cell death showing necrotic alteration is responsible for the enhanced release of HSV-1. The data also give some initial insights into the functional importance of cell death during the late stages of HSV-1 infection.

Enhancement of herpes simplex virus-induced polykaryocyte formation by 12-O-tetradecanoyl phorbol 13-acetate: association with the reorganization of actin filaments and cell motility

A morphological change induced by syn- herpes simplex virus type 1 (HSV-1), polykaryocyte formation, was enhanced by treatment with 12-O-tetradecanoyl phorbol 13-acetate (TPA) in A431 cells. TPA treatment decreased the number of stress fibers, but led to the development of spike-like filopodia and actin-containing long projections. Similar reorganization of actin filaments was observed in HSV-1-induced polykaryocytes. The actin filament-disrupting drug cytochalasin D, but not the microtubule-disrupting drug nocodazole, inhibited the effect of TPA on polykaryocyte formation, indicating that the actin microfilament system plays a key role in this event. HSV-1 glycoprotein D (gD) was present in the cytoplasm of HSV-1-infected cells and gD gene-transfected cells; its expression became prominent at long cell projections in the presence of TPA. These findings suggest that the reorganization of actin filaments and cell motility are associated with the enhancing effect of TPA on HSV-1-induced polykaryocyte formation.

Combination effect of adenovirus-mediated pro-apoptotic bax gene transfer with cisplatin or paclitaxel treatment in ovarian cancer cell lines

To develop a novel therapeutic strategy for ovarian cancer, we constructed a recombinant adenovirus which highly expresses pro-apoptotic Bax protein and examined its therapeutic effect on a series of ovarian cancer cell lines: A2780, A2780/cDDP, OVCAR-3 and SK-OV-3. A recombinant adenovirus carrying the Bax-alpha gene (AxCALNKYbax) induced high expression of the Bax-alpha protein in all the cell lines. The cytotoxic effect of Bax was observed in three ovarian cancer cell lines: the per cent reduction in the number of cells was 40.0% for cisplatin-sensitive A2780, 50.0% for cisplatin-resistant A2780/cDDP, and 64.8% for marginally cisplatin-resistant OVCAR-3. In contrast, it was only 12.3% for cisplatin-resistant SK-OV-3. Cisplatin-resistant A2780/cDDP had a p53 mutation and exhibited attenuated Bax induction after cisplatin treatment, which may explain why supplementation of Bax was effective in this chemoresistant ovarian cancer. Combination with cisplatin or paclitaxel enhanced the cytotoxic effect of Bax induction in all but one cell line including cisplatin-resistant A2780/cDDP. It appears that adenovirus-mediated Bax induction, with or without combination with conventional chemotherapy, useful strategy for the treatment of ovarian cancer.

Enhancing effects of fibroblast growth factor on the proliferation of salivary gland carcinoma cells and salivary gland carcinogenesis

The proliferation of mouse submandibular gland carcinoma YT-12 cells was stimulated by endothelial cell growth factor (ECGF)/bovine brain-derived acidic fibroblast growth factor (aFGF) and recombinant human aFGF. To determine whether aFGF was capable of modifying salivary gland carcinogenesis, the effect of brain-derived aFGF was examined in vivo. Mice in Groups 1 and 2 were injected with 9,10-dimethyl-1,2-benzanthracene (DMBA) into the left submandibular gland, and then Group 1 mice received bovine brain-derived aFGF and Group 2 mice received vehicle subcutaneously for 10 weeks. Group 3 and 4 mice received either bovine brain-derived aFGF or vehicle only. Sixteen weeks after the start of the experiment, the incidence of submandibular gland carcinomas in Group 1 was significantly greater than that in Group 2. Immunohistochemical study indicated that ducts in the normal submandibular glands and carcinomas showed positive staining with anti-aFGF antibody. Immunoblot and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed the expression of aFGF in these tissues. FGF receptor (FGFR)-1 and FGFR-4 were detectable in the mouse submandibular glands and carcinomas. These findings suggest that bovine brain-derived aFGF stimulates the proliferation of submandibular gland carcinoma cells and promotes mouse submandibular gland carcinogenesis.

Management of malignant ovarian tumors in young women. 21 nulliparous cases

To evaluate the management of malignant ovarian tumors in young women who wish to maintain fertility, we retrospectively reviewed ovarian malignancies in 21 young women who were both nulliparous and under 40 years of age. With stage 1a disease, all 9 patients were treated with conservative surgical therapies, and all of them are still alive, irrespective of histological type. With stage 1c disease, 5 (83%) of 6 patients were treated with conservative surgical therapies. Among them, 2 patients with epithelial tumors, who were treated with conservative surgical therapies and potent cis-diamminedichloroplatinum (CDDP)-based combined chemotherapies, are still alive. Furthermore, one of them had a successful pregnancy. On the other hand, 3 out of 4 patients with nonepithelial tumors were treated with conservative surgical therapies. However, 2 (67%) out of 3 died; both of them were treated with non-CDDP-based chemotherapy. In 6 patients with disease beyond stage 2, 4 (67%) were treated with radical surgical therapies, but 2 (33%) were treated with conservative surgery and CDDP-based combined chemotherapy, one of which was followed by a successful pregnancy in spite of nonepithelial tumor. As above, we could obtain some successful pregnancies in cases beyond stage 1c after conservative surgery by adding definite CDDP-based combined chemotherapy. However, we must carefully select the patients with nonepithelial tumors for conservative therapy by adding definite CDDP-based combined chemotherapy and inform them of the risks of therapy.

Mental nerve neuropathy as a result of primary herpes simplex virus infection in the oral cavity. A case report

We describe a 25-year-old woman who had mental nerve neuropathy. The symptom was attributed to herpes simplex virus infection, which appeared as herpetic gingivostomatitis 4 days after the extraction of the lower third molar. This case suggests that herpes simplex virus can infect the inferior alveolar nerve through an extraction wound and can induce mental nerve neuropathy.

[Orofacial alpha herpesvirus infection]

The mouth is the most common site of primary and recurrent herpes simplex virus (HSV) infection. The clinical appearance of recurrent intraoral HSV infection is similar to that of recurrent aphthous stomatitis. Reactivation of HSV occurs in bone marrow transplantation and is more frequent in patients conditioned with total body irradiation than in patients conditioned without total body irradiation. Although the effect of oral acyclovir to prevent recurrent herpes labialis is not confirmed, recurrent HSV lesions can be treated with the ointment formulation successfully. A therapeutic approach using replication-competent HSV may be useful in the treatment of tumors of epithelial origin, such as carcinoma of the upper aerodigestive tract.

Effect of epidermal growth factor administration on the development of mouse salivary gland carcinomas

This study investigated whether epidermal growth factor (EGF) administration was capable of modifying salivary gland carcinogenesis. Two groups of mice were given 1 mg of 9,10-dimethyl-1,2-benzanthracene (DMBA) into the left submandibular gland, and then Group 1 mice received 2 microg of EGF and Group 2 mice received vehicle subcutaneously for 8 weeks. Mice in two other groups, 3 and 4, received either EGF or vehicle alone. Twelve weeks after the start of the experiment, the incidences of submandibular gland carcinomas in Groups 1 and 2 were 39% and 58%, respectively, although this difference was not statistically significant. Duct- and cyst-like structures and carcinomas in the left submandibular glands were weakly stained by anti-EGF receptor (EGFR) antibody. Immunoblot and reverse transcriptase polymerase chain reaction (RT-PCR) analyses revealed the expression of EGFR in the submandibular glands and carcinomas. However, EGFR was undetectable in YT cells that were derived from a submandibular gland undifferentiated carcinoma of a Group 2 mouse. These findings indicate that EGF does not promote tumor induction in mouse salivary gland carcinogenesis. This may be ascribed in part to the low expression level of EGFR in tumor cells.

Human chorionic gonadotropin (hCG) inhibits cisplatin-induced apoptosis in ovarian cancer cells: possible role of up-regulation of insulin-like growth factor-1 by hCG

Gonadotropins have been suggested to play a role in the development or progression of ovarian cancer, and we have previously reported the expression of luteinizing hormone/ human chorionic gonadotropin (LH/hCG) receptor in 40% of epithelial ovarian carcinomas. To examine the biological effect of LH/hCG on ovarian cancer cells, apoptosis induced by cisplatin with or without hCG treatment was investigated in 2 ovarian cancer cell lines, OVCAR-3 and SK-OV-3. Stimulation of cell proliferation by hCG was also studied. In addition, to analyze further the mechanism of hCG signaling involved in apoptosis-inhibition, we examined the expression of LH/hCG receptors and the regulation by hCG for apoptosis-inhibitory pathways, such as the bcl-2/bax system and the insulin-like growth factor-1 (IGF-1)/IGF-1 receptor (IGFR) system. hCG did not increase cell proliferation in either cell line. However, hCG treatment suppressed cisplatin-induced apoptosis by 58% in the OVCAR-3 cells, as shown by immunofluorescent staining and quantitation of DNA fragmentation. LH/hCG receptor mRNA was expressed only in OVCAR-3, and no apoptosis-inhibitory effect of hCG was observed in the SK-OV-3 cells that did not express the receptor. In the OVCAR-3 cells, hCG significantly increased mRNA expression of IGF-1, but did not change mRNA levels of bcl-2/bax. Our findings suggest that LH/hCG influences the chemosensitivity of ovarian cancer cells through an apoptosis-inhibitory signal possibly via up-regulation of IGF-1 expression.

Expression of abnormal transcripts of the FHIT (fragile histidine triad) gene in ovarian carcinoma

To elucidate the role of the FHIT (fragile histidine triad) gene in ovarian carcinogenesis, the expression of the gene was analysed by reverse transcription-polymerase chain reaction (RT-PCR) in 51 cases of ovarian carcinoma, 6 cases of borderline tumour and 4 cases of benign ovarian tumour. The concomitant expressions of normal and abnormal FHIT transcripts were detected in 39% of carcinomas and in 83% of borderline tumours, while benign tumours and normal ovarian tissues expressed only normal transcript. In addition, there were 4 (8%) cases of carcinoma lacking expression of normal FHIT transcript, all of which were in advanced stages (stage III-IV) and poorly differentiated. These results suggest that the expression of abnormal transcripts of the FHIT gene is a feature of ovarian malignant/borderline tumours and that the complete loss of normal FHIT expression is related to the progression of ovarian carcinoma in a subset of the cases. However, abnormal FHIT transcripts themselves were not associated with any clinicopathological parameters, such as clinical stage, histological subtype of tumour, grade of differentiation or outcome of the patient. Additionally, abnormal FHIT expression was not associated with the presence of loss of heterozygosity (LOH) at this locus, suggesting that abnormal FHIT transcripts are not derived from genetic alteration or that genetic alteration at this locus is complicated.

Early invasive adenocarcinoma of the fallopian tube: a case report and review of the literature

We present an early invasive adenocarcinoma of the fallopian tube, which was incidentally found in a 45-year-old woman undergoing a laparotomy for uterine myoma. Histological examination of the hydropic tubes revealed widespread endosalpingeal hyperplasia without atypia in both tubes. In addition, the left tube contained 3 scattered lesions of carcinoma in situ, one of which was accompanied by a microfocus of definite stromal invasion confined within the endosalpingeal mucosa. Such a case seems extremely rare, and it might represent the histological appearance of an early invasive feature of tubal carcinoma. We reviewed previously reported cases of in situ and/or early invasive carcinomas of the fallopian tube with respect to the pathological diagnosis and histogenesis of primary tubal adenocarcinomas.

Expression of vascular endothelial growth factor (VEGF) during folliculogenesis and corpus luteum formation in the human ovary

Vascular endothelial growth factor (VEGF) has been suggested to be involved in angiogenesis and microvascular hyperpermeability. We examined immunohistochemically the expression of VEGF in the granulosa and theca cells, along with that of proliferating cell nuclear antigen (PCNA), in the vascular endothelium during the course of follicular development and corpora lutea formation in human ovaries. The immunolocalization of VEGF in these cells was compared with that of another putative angiogenic factor, basic fibroblast growth factor (bFGF). The granulosa cells in the primordial and primary follicles were VEGF negative, but at the preantral stage, the granulosa cells showed weakly positive immunostaining for VEGF. However, the VEGF immunostaining in the granulosa cells was weak throughout the folliculogenesis. In contrast, the theca interna cells of developing follicles showed strong staining for VEGF, which was well correlated with the PCNA positivity in the vascular endothelial cells in the thecal layer. In the atretic follicles, the granulosa and theca cells were VEGF negative. In the corpora lutea, VEGF was strongly expressed in both granulosa and theca lutein cells in the early luteal phase when the PCNA positivity in the endothelium increased, but the VEGF staining in these cells became weak in the mid- and late luteal phases. Accordingly, the PCNA positivity in the vascular endothelium was well correlated with the expression of VEGF in the theca cells during follicular development and atresia, and that in the granulosa and theca lutein cells in corpora lutea formation and regression. In addition, the immunolocalization of VEGF was different from that of bFGF.

Expression of pS2 protein in endometrial carcinomas: correlation with clinicopathologic features and sex steroid receptor status

Using immunohistochemistry, we examined pS2 expression in 64 samples of endometrial carcinoma, 11 samples of endometrial hyperplasia and 15 samples of normal endometrium, and compared them with clinicopathological data, estrogen receptor (ER) expression and progesterone receptor (PR) expression. Of the 64 samples of endometrial carcinoma, 45 (70%) expressed the pS2 protein. The average age of the patients with pS2-positive carcinomas (54.8 +/- 8.6 years) was significantly lower than that of the patients with pS2-negative carcinomas, and all premenopausal patients were positive for the pS2 protein. Among histological types, pS2 expression was observed in 33 (92%) of the 36 G1 carcinomas, but in none of the 5 nonendometrioid carcinomas. Of the 48 ER-positive carcinomas, 43 (90%) were pS2-positive and 5 were pS2-negative. Of the 40 PR-positive carcinomas, 37 (93%) were positive for pS2. There were significant associations between pS2 expression and ER/PR expression (p < 0.001). Staining of the pS2 protein was also observed in the samples of normal endometrium. We found a progressive increase in immunoreactivity of pS2 protein from normal endometrium to endometrial hyperplasia and still more in well-differentiated carcinoma. All 11 cases of endometrial hyperplasia were strongly positive for pS2. Furthermore, patients with pS2-positive carcinomas had a better survival rate than those with pS2-negative carcinomas (p < 0.05). Our data suggest that pS2 expression is likely correlated with estrogen-related endometrial carcinoma and is possibly involved in early disease progression.

The treatment with differentiation- and apoptosis-inducing agent, vesnarinone, of a patient with oral squamous cell carcinoma

A patient with histopathological recurrent oral cancer with well-differentiated squamous cell carcinoma, was treated with differentiation- and apoptosis-inducing agent, vesnarinone, per os at a dose of 180 mg/day for 56 days and then at a dose of 60 mg/day for 93 days. The vesnarinone administration caused complete remission of the tumour. It has been found by immunohistochemical staining and PCR-SSCP analysis that the recurrent tumour has wild type p53 gene and relative high level of LeY expression as well as DNA fragmentation in the cancer cells, as assessed by nick-end labelling. These findings suggest that the cure of oral squamous cell carcinoma observed in this case might be associated with induction of differentiation and apoptosis of cancer cells by vesnarinone.

Therapy for oral squamous cell carcinoma by tegafur and streptococcal agent OK-432 in combination with radiotherapy: Association of the therapeutic effect with differentiation and apoptosis in the cancer cells

Twenty patients with oral squamous cell carcinoma having mainly stage II or III lesions without distant metastasis, were treated with tegafur and streptococcal agent, OK-432, in combination with radiotherapy. As a consequence, 16 cases among the treated 20 cases showed complete remission by this therapy alone. Especially, we have found that the squamous cell carcinoma arising in non-keratinizing oral epithelium rather than in keratinizing oral epithelium has better response to this therapy. Among the 16 cases with complete remission (CR) by the current therapy, 10 cases were histopathologically diagnosed as well-differentiated squamous cell carcinoma and six cases as moderately differentiated squamous cell carcinoma. When we examined immunohistochemically the expression of various antigens such as proliferating cell nuclear antigen (PCNA), p53 and LeY or the presence of DNA fragmentation by nick-end labelling in the biopsy materials taken at the first visit to our clinic from 20 patients treated with the current therapy, the CR group showed a significantly increased LeY expres-sion level ( p< 0.05) and DNA fragmentation rate (p< 0.05) as compared with the partial response (PR, n= 3) + no change (NC, n= 1) group. On the other hand, the CR group with respect to PCNA expression level was significantly decreased as compared with the PR + NC group ( p< 0.05). From these findings, it can be considered that the therapy for oral squamous cell carcinoma by UFT and OK-432 in combination with radiotherapy is very effective, which may be associated with differentiation or apoptosis in oral squamous carcinoma cells. In addition, we present the clinical findings and results of immunohistochemical staining for the biopsy materials obtained from four CR cases treated with the current therapeutic method.

Effects of protein tyrosine kinase inhibitors on the replication of herpes simplex virus and the phosphorylation of viral proteins

The effect of protein tyrosine kinase (PTK) inhibitors on the replication of herpes simplex virus (HSV) was examined. Tyrphostins AG17, AG213, AG490, and AG555, and herbimycin A all inhibited the plaque formation of HSV type 1 (HSV-1) in Vero cells, but AG17, AG490, and AG555 exhibited a more selective antiviral effect. In the presence of 0.4 microM AG17, the virus production 24 h after infection was decreased to 7.7% of the untreated control level. Even if the treatment was started 12 h after the initiation of infection, the viral titer was reduced by 82.4%, compared with the untreated control level. In HSV-1-infected cells ICPs 6, 17/18, 19/20, and 25 were tyrosine-phosphorylated proteins. The synthesis and phosphorylation of these proteins were inhibited by AG17, and suppression of ICP 19/20, which were identified as the UL47 gene products, was the greatest. In contrast, the in vitro autophosphorylation of viral proteins was not affected by this PTK inhibitor. These results indicate that tyrphostin may represent a novel class of inhibitors of HSV-1, and that the viral proteins which have phosphorylated tyrosine residues and are suppressed by AG17 most significantly are the products of the UL47 gene, the tegument proteins VP13/14.

Parametrial involvement in endometrial carcinomas: its incidence and correlation with other histological parameters

To identify the incidence and spread pattern of parametrial involvement in endometrial carcinomas, resected parametria in 91 patients who underwent radical or modified radical hysterectomy with pelvic lymphadenectomy were histologically examined. The relationship between parametrial involvement and other histopathological features including histological type, tumor grade, depth of myometrial invasion, lymph-vascular space invasion, cervical involvement, adnexal metastasis, and lymph node metastasis was studied. Parametrial involvement was histologically demonstrated in 12 (13.2%) of the 91 cases. There were 2 patterns of spread: direct invasion of cancer cells to the parametrial connective tissue (5 cases) and lymphatic involvement within the parametrium (7 cases). According to the FIGO surgical stage, parametrial involvement was found in none (0%) of 48 patients in Stage I, 3 (11.5%) of 26 in Stage II, and 9 (52.9%) of 17 in Stage III. Among histopathological variables, the presence of parametrial involvement was significantly correlated with deep myometrial invasion and lymph-vascular space invasion in the myometrium. Multivariate analysis revealed that parametrial involvement significantly contributed to the poor prognosis in Stage II and III patients.

Immunohistochemical analysis of distribution of estrogen receptors and progesterone receptors in the postmenopausal endometrium

OBJECTIVE

To examine the expression of sex steroid receptors (ER: estrogen receptor; PR: progesterone receptor) in the postmenopausal endometrium (PMEM) and the relationship to clinical data for studying its characters.

METHODS

The immunohistochemical reactivity of the PMEM was studied using monoclonal antibodies against ER and PR, in 33 postmenopausal patients.

RESULTS

The endometrium was thicker in patients who were postmenopausal for 1 to 10 years (1.48 +/- 1.31 mm) than in patients who were postmenopausal for more than 10 years (0.79 +/- 0.37 mm)(p < 0.05). Among the 33 postmenopausal endometrial samples, ER positivity was found in the glands in 26 cases (78.8%) and PR positivity was detected in 18 cases (54.5%). The average age of the patients with ER positive reactivity in the glands (61.69 +/- 7.26 years) was significantly lower than that of the patients with ER negative reactivity (66.00 +/- 3.56 years)(p < 0.05). Furthermore, the endometrial thickness of the patients with ER or PR positive reactivity in the glands (1.24 +/- 1.09 mm and 1.47 +/- 1.20 mm, respectively) was significantly greater than that of the patients with ER or PR negative reactivity (0.67 +/- 0.26 mm and 0.70 +/- 0.40 mm, respectively)(p < 0.05).

CONCLUSION

ER in the glands of the PMEM was determined to decrease gradually with increased aging. The presence of ER and PR in the gland cells seemed likely to determine the thickness of the PMEM.

Hexamethylene bisacetamide as a chemopreventive agent in hamster cheek pouch tumorigenesis

The chemopreventive effect of oral and intraperitoneal (i.p.) administration of hexamethylene bisacetamide (HMBA) on 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced tumour formation in hamster cheek pouches was investigated. Male Syrian hamsters were treated by painting both cheek pouches with a 0.5% solution of DMBA twice weekly for 11 weeks. In addition to DMBA application, Group 1 hamsters were given 1% HMBA continuously in the drinking water and Group 2 hamsters received i.p. injection of HMBA at a dose of 500 mg/kg three times per week during the experiment. Group 3 animals received DMBA application alone. Thirteen weeks after the start of the experiment, the numbers of cheek pouch tumours and tumour volume were significantly decreased by oral but not i.p. administration of HMBA. Low levels of HMBA were detected in the plasma of the hamsters which were given 1% HMBA in drinking water. These results indicate that oral administration of HMBA can act as a chemopreventive agent against hamster cheek pouch tumorigenesis.

Effects of testosterone on tumor induction and epidermal growth factor production in the mouse submandibular gland

To determine whether testosterone administration was capable of modifying salivary gland carcinogenesis, female mice were given 1 mg of 9,10-dimethyl-1,2-benzanthracene (DMBA) into the left submandibular gland and then Group 1 mice received 5 mg of testosterone propionate and Group 2 mice received vehicle, olive oil, subcutaneously for 8 weeks. Twelve weeks after the start of the experiment, the weight of the left submandibular gland of the Group 2 mice was greater than that of the Group 1 mice. The incidences of submandibular gland carcinoma in Groups 1 and 2 were 41% (12/29) and 57% (17/30), respectively. Epidermal growth factor (EGF) levels of the left submandibular gland were significantly higher in Group 1 as compared with Group 2. These findings indicate that testosterone increases the production of EGF in the DMBA-injected submandibular gland, but does not promote the development of submandibular gland carcinoma.

Inhibitory effect of tyrphostin on the replication of herpes simplex virus type 1

Tyrphostins 9 and 47, inhibitors of protein-tyrosine kinase, inhibited the replication of herpes simplex virus type 1 (HSV-1), whereas tyrophostin 1, which does not inhibit protein-tyrosine kinase, did not affect the replication of HSV-1. The inhibitory effect of tyrphostin 9 was more potent than that of tyrphostin 47, and the IC50 of tyrphostin 9 was 40 nM. Sodium orthovanadate, an inhibitor of protein phosphotyrosine phosphatase, increased HSV-1 plaque formation and its effect was partly reversed by tyrphostin 9. The phosphorylation of viral phosphoproteins was decreased by tyrphostin 9 in a dose-dependent manner, but the tyrphostin 9-induced reduction of protein synthesis was not dose-dependent. At the late stage of infection, tyrosine phosphorylation was demonstrated in HSV-1 phosphoproteins. These results indicate that protein-tyrosine kinase is involved in the replication of HSV-1 and that tyrphostin can inhibit the synthesis and post-translational phosphorylation of the viral proteins.

Induction of carcinomas and sarcomas by 9,10-dimethyl-1,2-benzanthracene administration into the hamster maxillary sinus

To determine whether the local administration of 9,10-dimethyl-1,2-benzanthracene (DMBA) into the hamster maxillary sinus induced carcinoma at the injected site, hamsters were injected with 30 microliters of 0.5% solution of DMBA in dimethyl sulfoxide (DMSO) through the infraorbital foramen into the maxillary sinus once weekly for 10 weeks (Group 2). Another group of hamsters (Group 1) received similar injections of 30 microliters of DMSO only. In a third group of animals (Group 3), a roll of oxycellulose was inserted into the maxillary sinus and 40 microliters of a 2% solution of DMBA in DMSO was injected once. Sinonasal carcinomas were demonstrated in 73% (8/11) of the hamsters in Group 2 and sarcomas were shown in 73% (8/11) of the hamsters in Group 3, as well as some carcinomas. No tumors were seen in the Group 1 hamsters. Histologic examination revealed squamous cell carcinomas arising from the surface epithelium and submucous glands of the nasal cavity and maxillary sinus. These findings indicate that the intrasinal administration of a 0.5% solution of DMBA in DMSO is a reliable method for inducing maxillary sinus cancer.

Prenatally diagnosed female prune belly syndrome associated with tetralogy of Fallot

Female prune belly syndrome and tetralogy of Fallot were diagnosed in obstetric ultrasound screening at 13 and 28 weeks of gestation, respectively. The baby was born at 38 weeks showing abdominal distension, hypoplasia of abdominal muscles, vaginal atresia, imperforate anus and clubfeet. Radiologic and ultrasound examinations confirmed our prenatal diagnosis and revealed other abnormalities of patent ductus arteriosus, major aortopulmonary collateral arteries, bilateral vesicoureteral reflux, rectourethral fistula and hypoplasia of the right kidney. Urination has been smooth, but cystitis was observed repeatedly once a month. The infant was discharged in good condition and has been followed in the outpatient clinic.

Effect of local administration of epidermal growth factor on 9,10-dimethyl-1,2-benzanthracene-induced tumour formation in hamster cheek pouch

The effect of local administration of epidermal growth factor (EGF) on 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced tumour formation was investigated in a hamster cheek pouch carcinogenesis model. DMBA-treated hamsters underwent either sialoadenectomy (groups 1 and 2) or a sham operation (groups 3 and 4). Thereafter, EGF (groups 1 and 3) or vehicle (groups 2 and 4) was applied to the cheek pouches for 6 weeks. Fourteen weeks after the beginning of the experiment, the number of cheek pouch tumours was significantly greater in EGF-treated hamsters than in vehicle-treated hamsters, irrespective of whether the submandibular glands had been removed. The number of forestomach tumours, induced by DMBA application to the cheek pouches, was also increased by EGF. These results suggest that EGF applied from the luminal side of the mucosa stimulates tumour formation in the hamster cheek pouch and forestomach.

Effects of sialoadenectomy and epidermal growth factor administration on 9,10-dimethyl-1,2-benzanthracene-induced tumor formation in hamster cheek pouch

The effects of removal of the submandibular gland (sialoadenectomy) and administration of human urinary epidermal growth factor on the 9,10-dimethyl-1,2-benzanthracene-induced tumor formation were investigated with the use of a hamster cheek pouch model. Syrian hamsters were treated with 0.5% 9,10-dimethyl-1,2-benzanthracene for 6 weeks. Thereafter hamsters in group 1 underwent a sham operation and those in groups 2 and 3 underwent a sialoadenectomy. Subsequently, hamsters in groups 1 and 2 were given 0.9% sodium chloride and group 3 received the human urinary epidermal growth factor at a dose of 0.25 mg/kg body weight subcutaneously three times a week for 8 weeks. Sixteen weeks after the start of the experiment, the mean number of tumors that were less than 3-mm in diameter in groups 1 and 3 was significantly greater than that in group 2 (p < 0.05). The overall incidence and mean number of all carcinomas irrespective of size showed no differences among the experimental groups. These results indicate that epidermal growth factor synthesized in the submandibular gland may enhance the induction of cheek pouch tumor.

Inhibition of herpes simplex virus replication by genistein, an inhibitor of protein-tyrosine kinase

Genistein, an inhibitor of protein-tyrosine kinase, inhibited the replication of herpes simplex virus type 1 (HSV-1) at genistein concentrations of more than 25 microM, whereas the related compounds, which do not inhibit protein-tyrosine kinases, did not affect the replication of HSV-1. In the presence of genistein, the phosphorylation of tyrosine residues in specific viral polypeptides was markedly reduced. These results indicate that the phosphorylation of tyrosine residues in viral polypeptides may be essential for the replication of HSV-1.

Heparan sulfate as a mediator of herpes simplex virus binding to basement membrane

Explants of human lip and oral mucosa were infected with herpes simplex virus (HSV) in vitro and the expression of viral antigen was investigated by immunofluorescent antibody staining. Viral antigen was demonstrated in the cells of basal cell layer and lower prickle cell layers. Moreover, an accumulation of viral antigen in the epithelial-mesenchymal junction was observed. To examine the possibility that the basement membrane has an affinity for HSV, the interaction between HSV and major basement membrane components including type IV collagen, laminin, fibronectin, and heparan sulfate was investigated. When tested by a plaque-reduction assay, only heparan sulfate inhibited HSV plaque formation by competing for the virus adsorption to HEp-2 cells. The inhibitory effects of heparan sulfate and heparin were not affected by pre-incubation of these glycosaminoglycans with antithrombin III, whereas de-N-sulfation resulted in a significant reduction of their inhibitory activity. These findings suggest that heparan sulfate is involved in the binding of HSV to the basement membrane and that N-sulfated glucosamine residues of heparan sulfate are essential for HSV binding. The basement membrane may act as a reservoir of HSV in muco-cutaneous tissues.

Effect of dibutyryl cyclic adenosine 3',5'-monophosphate on morphological features and biological markers of human salivary myoepithelial cell line in culture

We have found the emergence of myoepithelial cells (HSG-AZA1) in neoplastic human salivary intercalated duct cell line HSG in culture after treatment with 5-azacytidine. When HSG-ZAZ1 cells were cultured in the presence of N6,O2-dibutyryl cyclic adenosine 3',5'-monophosphate (dB-cAMP), they formed long cytoplasmic processes which were densely packed with ample microfibrils in addition to microtubule bundles. The expression of neuron-specific enolase, synaptophysin, and catecholamine as well as neurofilaments in the treated HSG-AZA1 cells was found by the immunofluorescence staining technique, immunoblotting, immunoelectron microscopy, or catecholamine fluorescence. Both the anchorage-independent and anchorage-dependent growths of HSG-AZA1 cells were suppressed in the presence of dB-cAMP. After the removal of dB-cAMP from the culture, the treated cells returned rapidly to the phenotype and growth rate of the untreated cells. These findings indicate that reversible differentiation into the neuron-like cells of HSG-AZA1 cells occurs in growth medium containing dB-cAMP.

ras gene alterations in invasive and non-invasive rat bladder carcinomas induced by N-methyl-N-nitrosourea

We have established a reliable method to induce invasive and non-invasive carcinomas in the heterotopically transplanted urinary bladder of rats by repeated injection of N-methyl-N-nitrosourea (MNU), and examined the alterations of the ras oncogenes and ras oncogene product (p21) in the induced tumours. The incidence of muscle-invasive carcinomas was proportional to the total dose of MNU. When 5, 6 or 12 doses of MNU were used, muscle invasive carcinomas developed in 22, 58 or 45% of animals, respectively, after a mean observation period, respectively, of 54 +/- 9, 45 +/- 13 and 38 +/- 3 weeks. Whereas activated H-ras gene was detected in only one non-invasive carcinoma by DNA transfection assay, seven of 18 non-invasive and invasive carcinomas showed activated ras p21 when examined by immunoblot analysis. Amplification or rearrangement of myc or epidermal growth factor (EGF) receptor gene was not observed. The results indicate that alterations of ras gene may be involved in the development of rat bladder carcinomas but not of invasiveness.

Enhanced replication of herpes simplex virus by hexamethylene bisacetamide

Hexamethylene bisacetamide (HMBA) is a potent inducer of differentiation of tumor cells. The effect of HMBA on cell growth and replication of herpes simplex virus (HSV) was investigated in HEp-2 epidermal cells, IMR-32 neuronal cells, K562 myeloid cells, Daudi Burkitt lymphoma cells, and CCRF-CEM T-lymphoid cells. The growth of HEp-2 and IMR-32 cells was not affected by HMBA at concentrations from 0.5 through 2 mM. The growth of K562, Daudi, and CCRF-CEM cells was inhibited by HMBA at concentrations from 1 through 5 mM. When HSV-infected cells were incubated with 0.5 through 5 mM HMBA, a dose-dependent increase in virus yield was observed in HEp-2 and IMR-32 cells, but not in the other cell lines. These findings indicate that HMBA enhances the replication of HSV in epidermal and neuronal cells and that HMBA therapy may be responsible for the development of herpetic lesions.

Herpes simplex virus type 1 and type 2 infection in human oral mucosa in culture

To examine the sensitivity of human oral mucosa to herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infection, human gingival mucosa explants were infected with either HSV-1 or HSV-2 in vitro and the expression of virus specific antigen was examined by the immunofluorescent antibody technique. HSV-2 antigen was found in the basement membrane, basal cell layer and lower prickle cell layer. This finding was consistent with the HSV-1 infection. Electron microscopic study revealed the presence of nucleocapsids and enveloped virus particles in the basal cells of HSV-2-infected organ cultures. These findings indicate that human gingival mucosa is sensitive to infection with HSV-2, as well as HSV-1, and that the virus may replicate in the undifferentiated epithelial cells of mucosal epithelium.

Effect of hexamethylene bisacetamide and cyclosporin A on recovery of herpes simplex virus type 2 from the in vitro model of latency in a human neuroblastoma cell line

The goal of the present work was to examine whether hexamethylene bisacetamide (HMBA) and cyclosporin A affect the recovery of herpes simplex virus type 2 (HSV-2) from an in vitro model of HSV-2 latency in human neuroblastoma cell line IMR-32. IMR-32 cells were infected with HSV-2 at a multiplicity of infection of 0.1 plaque-forming units/cell and were cultured at 40 degrees C for 14 days, resulting in the establishment of a model of HSV-2 latency in IMR-32 cells. When the cultivation temperature was shifted down from 40 to 37 degrees C, recovery of virus growth began to occur after an incubation period of 2 days. During the time of shift-down of the incubation temperature, the latently infected cells were further cultured at 37 degrees C in the presence or absence of 5 mM HMBA or 0.5 micrograms/ml cyclosporin A, which does not affect stability of HSV-2 nor proliferation of IMR-32 cells. Consequently, the rate of HSV-2 recovery from the latently infected cells cultured in the presence of 5 mM HMBA was significantly increased, as compared with the untreated controls. In addition, the DNA methylation level of the latently infected IMR-32 cells cultured in the presence of HMBA was significantly decreased when compared to the level in the untreated controls. On the other hand, the cultivation of the latently infected cells in the presence of 0.5 micrograms/ml cyclosporin A resulted in a significant decrease in the rate of HSV-2 recovery. These findings indicate that the recovery of HSV-2 from the model of latency in IMR-32 cells is enhanced by HMBA treatment, which induces a significant decrease of total genomic DNA methylation level, and is inhibited by cyclosporin A treatment.

Induction of cells with phenotypic features of neuronal cells by treatment with dibutyryl cyclic adenosine 3',5'-monophosphate in a human parotid gland adenocarcinoma cell line in culture

A human parotid gland adenocarcinoma cell line, with an intercalated duct cell phenotype of the salivary gland and expression of vasoactive intestinal polypeptide and amylase, was cultivated in the presence of dibutyryl cyclic adenosine 3',5'-monophosphate (dB-cAMP). Morphological changes occurred; cells formed long cytoplasmic processes densely packed with ample microfibrils, as well as microtubules, and grew in a netlike appearance. In addition, it has been found by the immunofluorescence staining technique, immunoblotting, or immunoelectron microscopy that the cells treated with dB-cAMP express neurofilaments, neuron-specific enolase, synaptophysin, and HNK-1 antigen, as well as the alpha- and beta-chains of tubulin, whereas these antigens are not detected in untreated cells. The expression of vasoactive intestinal polypeptide detected diffusely in the cytoplasm of untreated cells was restricted to the cell membranes during the cultivation of cells in the presence of dB-cAMP, while expression of amylase persisted in the treated cells in a fashion similar to that in untreated cells. Moreover, both anchorage-independent and anchorage-dependent growth of the cells was markedly suppressed in the presence of dB-cAMP. After removal of dB-cAMP from the culture, the treated cells returned rapidly to the phenotype and growth rate of the untreated cells. These findings indicate that reversible conversion into cells with phenotypic features of neuronal cells of a human parotid adenocarcinoma cell line occurs in growth medium containing dB-cAMP.

Involvement of urine in epithelial-stromal interactions in urinary bladder carcinogenesis

The role of urine in epithelial-stromal interactions in urinary bladder carcinogenesis was investigated using the 'Stroma' bladder model established in our laboratory. Rats treated with 0.05% N-butyl-N-(4-hydroxybutyl) nitrosamine (BHBN) in drinking water for 4 weeks or age-matched untreated rats served as donors of bladders with denuded epithelium ('stroma' bladders), which were resurfaced 4 days later with urothelial cells from rats treated with 0.05% BHBN for 4 weeks. Subsequently, the transplants received weekly injections of normal rat urine or saline. In the urine-free environment, cell implants developed hyperplastic changes but few tumor formations with no significant difference between the two types of 'stroma' bladder. In contrast, urine instillation stimulated neoplastic growth, and tumor-enhancing effect was significantly accelerated in the BHBN-treated 'stroma' bladder group as compared to the control group. These results suggest that epithelial-stromal interactions are altered in such a way that bladder carcinogenesis is enhanced by prior exposure of the bladder stroma to carcinogen and subsequent urine contact.

Stimulation of stromal cell growth by normal rat urothelial cell-derived epidermal growth factor

Primary cultured adult rat urothelial (RU) cells caused increased thymidine incorporation in rat bladder stromal (RS) cells in a coculture system. The concentrated conditioned medium derived from RU cell culture (CM-RU) also stimulated the growth of RS cells, and induced anchorage independent growth of NRK-49F cells. Since these activities were heat and acid resistant, we investigated whether epidermal growth factor (EGF) and/or transforming growth factors were the humoral factor(s) responsible. The immunodiffusion analysis of CM-RU gave a positive precipitin line with rabbit anti-rat EGF IgG but not with rabbit anti-rat transforming growth factor-alpha antibodies. The anti-rat EGF IgG inhibited CM-RU-stimulated thymidine incorporation into RS cells, whereas normal rabbit IgG did not. By immunofluorescent technique using rabbit anti-rat EGF antibodies, immunoreactive EGF was demonstrated in RU cells and the urothelial of cryoinjury-induced reparative hyperplasia. Immunofluorescent technique also demonstrated the presence of EGF receptors on the cell membrane of RU and RS cells, basal cells of normal rat urothelium, and cells of whole epithelial layers of reparative hyperplasia. These data strongly suggest that EGF or an EGF-like substance produced by RU cells and released into medium stimulates the growth of RS cells possibly mediated by EGF receptors.

Effects of urinary transferrin and ornithine decarboxylase-inducing fraction on rat bladder carcinogenesis

Using heterotopically transplanted rat urinary bladder (HTB) system, we previously have shown that contact with urine enhanced bladder carcinogenesis initiated by carcinogen. In order to screen urine for promoter substances, several short term in vitro assays were developed and their results were correlated with the in vivo assay results. Chromatographically separated urine fractions were examined for the inability to induce ornithine decarboxylase (ODC), to enhance incorporation of [3H]thymidine in a bladder carcinoma cell line (804G) and to form colonies in soft agar by NRK-49F. Data from the ODC assay and soft agar colony formation correlated well with the results derived from chronic animal studies. Thus then two assays appear useful in further screening urine for promoter substance. Data furthermore indicate that ODC-inducing urine component(s) may play a primary role in the steps following initiation whereas transferrin, a mitogenic urine component, may play a secondary role.