Human Testicular Cancer Research Articles

ATM Activation in Normal Human Tissues and Testicular Cancer

The ATM kinase is a tumor suppressor and key regulator of biological responses to DNA damage. Cultured cells respond to genotoxic insults that induce DNA double-strand breaks by prompt activation of ATM through its autophosphorylation on serine 1981. However, whether ATM-S1981 becomes phosphorylated in vivo, for example during physiological processes that generate DSBs, is unknown. Here we produced phosphospecific monoclonal antibodies against S1981-phosphorylated ATM (pS-ATM), and applied them to immunohistochemical analyses of a wide range of normal human tissues and testicular tumors. Our data show that regardless of proliferation and differentiation, most human tissues contain only the S1981-nonphosphorylated, inactive form of ATM. In contrast, nuclear staining for pS-ATM was detected in subsets of bone-marrow lymphocytes and primary spermatocytes in the adult testes, cell types in which DSBs are generated during physiological V(D)J recombination and meiotic recombination, respectively. Among testicular germ-cell tumors, an aberrant constitutive pS-ATM was observed especially in embryonal carcinomas, less in seminomas, and only modestly in teratomas and the pre-invasive carcinoma-in-situ stage. Compared with pS-ATM, phosphorylated histone H2AX (?H2AX), another DNA damage marker and ATM substrate, was detected in a higher proportion of cancer cells, and also in normal fetal gonocytes, and a wider range of adult spermatocyte differentiation stages. Collectively, our results strongly support the physiological relevance of the recently proposed model of ATM autoactivation, and provide further evidence for constitutive activation of the DNA damage machinery during cancer development. The new tools characterized here should facilitate monitoring of ATM activation in clinical specimens, and help develop future treatment strategies.

Gallbladder carcinoma: the role of p53 protein overexpression and Ki‐67 antigen expression as prognostic markers

The overexpression of p53 protein and the expression of Ki-67 antigen may affect the survival of patients with gallbladder carcinoma. This association has been tested in a series of 41 patients with relatively early carcinoma of the gallbladder. Forty-one surgical specimens from patients with a postoperative histological diagnosis of gallbladder carcinoma were studied. All patients were operated by simple cholecystectomy only because the tumours were not advanced and/or their general condition was poor. Patients submitted to radical operations were excluded. p53 expression was calculated from nuclear staining according to the intensity and extent of positive cells, as graded on a scale from 1 to 3; a combined score of >3 was considered as overexpression. Ki-67 expression was calculated by the MIB-I index: the percentage of positively stained tumour cell nuclei out of the total tumour cells counted (n = 1000); >20% of stained cells was considered positive. Twenty-nine gallbladder carcinomas (71%) overexpressed p53 protein in the cell nuclei. No significant differences were found in relation to cell differentiation on the level of tumour infiltration through the gallbladder wall. Five-year survival of patients with gallbladder carcinoma overexpressing p53 was 17.2%, while survival of patients without p53 overexpression was 30% (not significant). Twenty-four cases (58.5%) were considered positive for the MIB-I index. There were no differences between the grade of cell differentiation and wall infiltration. Five-year survival of the patients with a MIB-I positive index was 9.2% as opposed to 27.7% for those with a negative index (not significant). p53 protein nuclear overexpression and Ki-67 protein expression in gallbladder carcinoma were not related to histological differentiation, level of gallbladder wall invasion or patient survival.

Relationship between lipoxygenase and human testicular cancer

The metabolism of arachidonic acid by either the cyclooxygenase (COX) or lipoxygenase (LOX) pathway generates eicosanoids, which have been implicated in the pathogenesis of a variety of human diseases, including cancer. They are now believed to play important roles in tumor promotion, progression, and metastasis, and the involvement of LOX expression and function in tumor growth and metastasis has been reported in human tumor cell lines. Expressions of 5-LOX and 12-LOX in human testicular cancer (TC), and normal testis (NT) tissues were examined, as well as effects of their inhibitors on cell proliferation in TC cell line. Expressions of 5-LOX and 12-LOX were detected by immunohistochemistry. Effects of LOX inhibitors on TC cell growth were examined by MTT assay. While 5-LOX and 12-LOX expressions were slightly detected in NT tissues, expressions of 5-LOX and 12-LOX were significant detected in TC tissues by immunohistochemistry. The LOX inhibitors inhibited the growth of TC cells. LOX is induced in TC, and results may suggest that LOXs are essential for cell growth of TC cells.

P66Shc protein is upregulated by steroid hormones in hormone-sensitive cancer cells and in primary prostate carcinomas.

Members of Shc family conventionally serve as critical adaptors in tyrosine phosphorylation signal transduction pathways. p66(Shc) protein, a member of Shc family, is predominantly expressed in epithelial cells, whereas the regulation of its expression remains an enigma. We describe the effect of steroid hormones on the protein level of p66(Shc) and growth stimulation in hormone-sensitive human prostate, testicular and breast cancer cells. In DHT-treated androgen-sensitive prostate cancer LNCaP C-33 cells, the protein level of p66(Shc) was elevated by approximately 3-fold, correlating with increased cell growth. This DHT effect on p66(Shc) protein level and growth regulation was also observed in another androgen-sensitive prostate cancer cell line MDA PCa2b as well as 2 testicular cancer cell lines, Tera-1 and Tera-2 cells. Similarly, the female sex hormone estrogen had a stimulating effect on p66(Shc) protein level and proliferation in estrogen-sensitive MCF-7 breast cancer cells. The upregulation of p66(Shc) protein level by DHT was competitively abolished by Casodex, an androgen antagonist used to treat prostate cancer. Moreover, immunohistochemical analyses showed that the p66(Shc) protein level was significantly higher in primary prostate tumors than in adjacent non-cancerous cells (p < 0.05). The data collectively indicate that p66(Shc) protein levels correlate with steroid hormone-stimulated cell growth and prostate carcinogenesis.

Cyclooxygenase-1 and -2 in human testicular tumours

In this study, we investigated the expression of cyclooxygenase (COX)-1 and -2 in human testicular cancer (TC) and normal testis (NT) tissues, as well as the effects of COX ligands on viability and proliferation. Tumour specimens were obtained from 72 patients with TC and 20 patients with NT. RT-PCR and immunohistochemical methods were used to determine COX expression. While COX expression was not noted in any of the NT tissues, a marked expression was observed in the TC samples. The extent and intensity of immunoreactive COX-1 and -2 polypeptides in the TC tissues was statistically greater than the expression in the NT tissues. The synthetic COX inhibitors inhibited the growth of the TC cells. Both COX-1 and COX-2 are induced in testicular cancer, and these results indicate that both COX-1 and COX-2 are essential for the growth of TC cells.

Human tissue kallikreins and testicular cancer.

Human tissue kallikreins are fifteen homologous genes encoding for secreted serine proteases and residing tandemly on chromosome 19q13.4. These enzymes are highly expressed in a variety of tissues and participate in diverse physiological processes. Human tissue kallikreins were found to be associated with several malignancies, especially endocrine-related cancers, including prostate, ovarian, breast and testicular cancer. In testicular germ cell tumors, some tissue kallikrein genes, including KLK5, KLK10, KLK13 and KLK14, were found to be significantly down-regulated. Tissue-specific splice variant forms of some kallikreins have been identified in the testis. In this paper, the expression of KLK5, KLK10, KLK13 and KLK14 in testicular cancer and their possible roles during testicular cancer development, as well as their clinical applications are briefly reviewed.

Expression of peroxisome proliferator-activated receptors in human testicular cancer and growth inhibition by its agonists

Objectives. To investigate the expression of peroxisome proliferator activator-receptor (PPAR)-alpha, beta, and gamma in human testicular cancer (TC) and normal testicular (NT) tissues, as well as the effects of the PPAR-gamma ligand. Recent studies have demonstrated that PPAR-gamma is expressed in various cancer tissues and its ligand induces growth arrest of these cancer cells through apoptosis. However, the expression of PPARs and the effects of PPAR-gamma ligand in testis have not been examined. Methods. Tumor specimens were obtained from 72 patients with TC. Specimens were obtained from 20 patients with NT tissue. The expressions were investigated using reverse transcriptase-polymerase chain reaction and immunohistochemical methods. We also investigated the inhibitory effect of the PPAR-gamma ligand on the TC-derived cell line. Results. Immunoreactive PPAR-alpha and beta were significantly apparent in TC tissues. Marked expression of PPAR-alpha and beta was also detected in the NT group. However, very weak or no expression of immunoreactive PPAR-gamma was found in the NT cases. In contrast, we found significant expression of immunoreactive PPAR-gamma in the cancer cells in the TC group. The synthetic PPAR-gamma agonists thiazolidinedione compounds and the endogenous PPAR-gamma ligand, 15-deoxy-Δ 12,14-prostaglandin J 2, inhibited the growth of the TC cells. Conclusions. PPAR-gamma is induced in TC, and the results suggest that PPAR-gamma ligands may mediate potent antiproliferative effects against TC cells through differentiation. Thus, PPAR-gamma may become a new target in the treatment of TC.

SN-38 Induces Cell Cycle Arrest and Apoptosis in Human Testicular Cancer

CPT-11 is one of the most widely used camptothecin analogues and is converted to form the active metabolite SN-38. Clinical trials are ongoing to better characterize its spectra of clinical activity, to determine the optimal schedules of administration, and to define the usage in combination with other chemotherapeutic compounds. KU-MT, an AFP-producing testicular carcinoma cell line, was exposed to SN-38, etoposide, or cisplatin for 24 h, and the resulting cytotoxicity was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazonium bromide (MTT) assay. This paper describes the effects of SN-38 on the cell proliferation and cell cycle of testicular tumor cells in culture. SN-38 was shown to inhibit KU-MT cell growth more potently than either etoposide or cisplatin. A marked decrease in the percentage of S phase cells was accompanied by the enhancement of cyclin E levels. In concentrations of >30 nmol/l, SN-38 arrested the cell cycle in G2 and induced cell death via apoptosis. The apoptosis was promoted by Bax and p53 protein, which were both shown to be present by flow cytometric and Western blot analyses. These results suggest that CPT-11, a pro-drug of SN-38, may be clinically useful for the treatment of testicular cancer, and that the mechanism of this agent's cytotoxicity consists of cell cycle arrest and concomitant apoptosis.

Novel Binding of HuR and Poly(C)-binding Protein to a Conserved UC-rich Motif within the 3′-Untranslated Region of the Androgen Receptor Messenger RNA

The androgen receptor (AR) mediates androgen action and plays a central role in the proliferation of specific cancer cells. We demonstrated recently that AR mRNA stability is a major determinant of AR gene expression in prostate and breast cancer cells and that androgens differentially regulate AR mRNA decay dependent on cell type (Yeap, B. B., Kreuger, R. G., Leedman, P. J. (1999) Endocrinology 140, 3282-3291). Here, we have identified a highly conserved UC-rich region in the 3-untranslated region of AR mRNA that contains a 5'-C(U)(n)C motif and a 3'-CCCUCCC poly(C)-binding protein motif. In transfection studies with LNCaP human prostate cancer cells, the AR UC-rich region reduced expression of a luciferase reporter gene. The AR UC-rich region was a target for cytoplasmic and nuclear RNA-binding proteins from human prostate and breast cancer cells as well as human testicular and breast cancer tissue. One of these proteins is HuR, a ubiquitously expressed member of the Elav/Hu family of RNA-binding proteins involved in the stabilization of several mRNAs. Poly(C)-binding protein-1 and -2 (CP1 and CP2), previously implicated in the control of mRNA turnover and translation, also bound avidly to the UC-rich region. Mutational analysis of the UC-rich region identified specific binding motifs for both HuR and the CPs. HuR and CP1 bound simultaneously to the UC-rich RNA and in a cooperative manner. Immunoprecipitation studies confirmed that each of these proteins associated with AR mRNA in prostate cancer cells. In summary, we have identified and characterized a novel complex of AR mRNA-binding proteins that target the highly conserved UC-rich region. The binding of HuR, CP1, and CP2 to AR mRNA suggests a role for each of these proteins in the post-transcriptional regulation of AR expression in cancer cells.

Decreased telomerase activity is not a reliable indicator of chemosensitivity in testicular cancer cell lines

Telomere stabilisation is a critical step in tumorigenesis and telomerase, an enzyme which counteracts telomeric DNA loss, is active in most tumours. Conflicting evidence has been published concerning the potential use of telomerase activity as a measurement of drug-induced tumour cell killing. In this study, the time courses of telomerase loss and induction of apoptosis were investigated in two testicular cell lines, Susa CP and 833 K, following 4-h exposure to cisplatin, melphalan or doxorubicin. Telomerase activity was only affected in both cell lines at 20 h following exposure to high concentrations of cisplatin (100× the drug concentrations causing 50% growth inhibition (IC50 values)). The time course of melphalan-induced telomerase loss, which was again only apparent at 100× IC50 concentrations, varied between the cell lines and doxorubicin (100× IC50) did not induce telomerase loss in either of the cell lines. Importantly, the levels and rates of appearance of apoptotic cells (nuclear morphology and annexin V staining) were similar for all three drugs in both cell lines; i.e. cisplatin, melphalan and doxorubicin (100× IC50) caused similar frequencies of apoptosis in Susa CP cells at 24 h whereas telomerase activities were 65, 123 and 96% of the control, respectively. The possibility that telomerase activity was lost following cisplatin treatment through a direct interaction of cisplatin with telomerase was discounted. Additionally, the relative levels of the RNA component of telomerase (hTR) and mRNA for the telomerase catalytic subunit (hTERT) were not related to the observed decreases in telomerase activity. These data indicate that telomerase activity is not a reliable indicator of chemosensitivity in human testicular cancer cells. Furthermore, cisplatin-induced loss of telomerase activity is not due to a direct reaction with the enzyme or decreased hTR levels.

Bis(4,7-dimethyl and 5-dinitro-1,10-phenanthroline) sulfato-oxovanadium(IV)-mediated in vivo male germ cell apoptosis.

Oxovanadium(IV) [VO] complexes of 1,10-phenanthroline are a new class of potent apoptosis-inducing cytotoxic agents against human testicular cancer cells in vitro. The present study investigated the in vivo ability of four(bis)-chelated 1,10-phenanthroline [phen] complexes of sulfato-oxovanadium(IV)-VO(phen)(2), VO(Cl-phen)(2), VO(Me(2)-phen)(2) and VO(NO(2)-phen)(2)-with and without substitutions, to induce testicular germ cell apoptosis. Male germ cell loss in mice was measured by determining the epididymal sperm count, testicular weight and histological evaluation of the testes. Repetitive intratesticular injection (7.5 mg kg(-1) testis(-1)) of bis-chelated 1,10-phenanthroline complexes of oxovanadium(IV) with 4,7-dimethyl [VO(Me(2)-phen)(2)] and 5-dinitro [VO(NO(2)-phen)(2)] substitution led to decreased sperm counts and reduced testicular weights. Histopathological examination of testicular sections from VO(Me(2)-phen)(2)- and VO(NO(2)-phen)(2)-treated mice revealed a marked inhibition of spermatogenesis and preferential loss of maturing, as well as elongated spermatids. In situ evaluation of seminiferous tubule cross-sections by terminal deoxynucleotidyl transferase-mediated FITC-deoxyuridine triphosphate nick end-labeling (TUNEL) and laser scanning confocal microscopy showed characteristic apoptotic germ cells delineating the periphery of the seminiferous tubules. The ability of bis-chelated 4,7-dimethyl- and 5-dinitro-substituted 1,10-phenanthroline complexes of oxovanadium(IV) to induce germ cell apoptosis in vivo may have potential utility in the treatment of human testicular germ cell tumors.

Vanadocene-Mediated in Vivo Male Germ Cell Apoptosis

Vanadocenes are potent apoptosis-inducing cytotoxic agents against human testicular cancer cells in vitro. The present study investigated the ability of four vanadocenes—vanadocene diazide (VDA), vanadocene dicyanate (VDCN), vanadocene dioxycyanate (VDOCN), and vanadocene monochloro oxycyanate (VDCO)—to induce male germ cell apoptosis in vivo in mouse testes by repetitive intratesticular injection of vanadocenes (7.5 mg/kg/testis) for 28 days. Germ cell loss in vivo was measured by epididymal sperm count, testes weights, and histologic evaluation of the testes. Repetitive intratesticular injection of vanadocenes led to decreased sperm counts and reduced testicular weights. Histopathological examination revealed seminiferous tubular atrophy, inhibition of spermatogenesis, and the preferential loss of maturing and elongated spermatids. In situ evaluation by the terminal deoxynucleotidyl transferase-mediated FITC–deoxyuridine triphosphate nick-end labeling (TUNEL) of seminiferous tubule cross sections and laser confocal microscopy showed characteristic apoptotic cells identified primarily as pachytene spermatocytes delineating the periphery of the seminiferous tubules. The ability of vanadocenes to induce germ cell apoptosis in vivo may have potential utility in the treatment of testicular seminomas in humans.

Expression of fibroblast growth factor (FGF)-8 isoforms and FGF receptors in human ovarian tumors.

FGF-8 is a mitogenic growth factor, which is widely expressed during embryonic development but only at a very low level in adult tissues. Alternative splicing of the human FGF-8 gene potentially allows coding for 4 protein isoforms (a, b, e, f), which differ in their transforming capacity. The FGF-8 isoforms preferentially activate the receptors FGFR1IIIc, FGFR2IIIc, FGFR3IIIc and FGFR4. FGF-8 is over-expressed in human breast and prostate cancers. Expression has also been found in RT-PCR studies of human ovarian and testicular cancers. The present study was undertaken to examine which FGF-8 isoforms are expressed in ovarian cancer and whether FGF-8 receptors are also expressed. Specimens from 5 normal human ovaries and 51 ovarian tumors (1 benign tumor, 8 borderline malignancies, 42 malignant tumors of different histopathological types) were studied by RT-PCR and immunohistochemistry. FGF-8 isoform b was expressed in all ovarian tumors and in all 7 ovarian-cancer cell lines studied. Isoform a was co-expressed in 9 malignant ovarian tumors. FGF-8 mRNA was not detected by RT-PCR of 3 normal ovary samples. Immunohistochemical staining localized FGF-8 protein to cancer cells. In general, the increased intensity of FGF-8 staining was associated with loss of differentiation within the tumors (Bowker's test, p = 0.37). FGF-8 staining of surface epithelium observed on 2 normal ovaries was very faint. RT-PCR showed that FGFR1IIIc, FGFR2IIIc and FGFR4 were the FGF-8 receptors expressed in normal ovaries and in ovarian tumors. FGF-8 receptor immunoreactivity was preferentially found in normal ovary surface epithelium and tumor cells but also in some stromal cells. Collectively, our results show that ovarian cancers of a wide variety of histological types expressing receptors for FGF-8 have acquired the capacity of expressing FGF-8. This suggests that FGF-8 has an important role in ovarian tumorigenesis.

Demonstrating Angiogenesis In a Human Testicular Malignant Tumor Using the Scid-Maus Model. Intravital Video Microscopy and Scanning Electron Microscopy of Vascular Corrosion Casts

Abstract Growth of malignant tumors relies on development of new vessels from the existing vessels, a process called angiogenesis. Little is known about the pattern of chronic vascular growth in the human germ cell testicular cancer. To shed light on this topic, we injected human CRL-2073 testicular cancer cells or saline (sham treated mice) into the testes of SCID-mice and studied the growth of the tumor's vasculature using intravital video microscopy (IVM) on days 7, 14, 21, 28 and 37 after injection. On each day, 4 mice were studied. To better identify microvessels, fluorescein isothiocyanate-dextran (FITC) was injected i.v. prior to IVM. After IVM, one testis was cast with Mercox and studied in a scanning electron microscope (SEM), the other was used for histology. IVM images were transferred to the computer and analyzed using the Lucia morphometry software.

D-type cyclins in adult human testis and testicular cancer: relation to cell type, proliferation, differentiation, and malignancy.

D-type cyclins are proto-oncogenic components of the 'RB pathway', a G1/S regulatory mechanism centred around the retinoblastoma tumour suppressor (pRB) implicated in key cellular decisions that control cell proliferation, cell-cycle arrest, quiescence, and differentiation. This study focused on immunohistochemical and immunochemical analysis of human adult testis and 32 testicular tumours to examine the differential expression and abundance of cyclins D1, D2, and D3 in relation to cell type, proliferation, differentiation, and malignancy. In normal testis, the cell type-restricted expression patterns were dominated by high levels of cyclin D3 in quiescent Leydig cells and the lack of any D-type cyclin in the germ cells, the latter possibly representing the only example of normal mammalian cells proliferating in the absence of these cyclins. Most carcinoma-in-situ lesions appeared to gain expression of cyclin D2 but not D1 or D3, while the invasive testicular tumours showed variable positivity for cyclins D2 and D3, but rarely D1. An unexpected correlation with differentiation rather than proliferation was found particularly for cyclin D3 in teratomas, a conceptually significant observation confirmed by massive up-regulation of cyclin D3 in the human teratocarcinoma cell line NTera2/D1 induced to differentiate along the neuronal lineage. These results suggest a possible involvement of cyclin D2 in the early stages of testicular oncogenesis and the striking examples of proliferation-independent expression point to potential dual or multiple roles of the D-type cyclins, particularly of cyclin D3. These findings extend current concepts of the biology of the cyclin D subfamily, as well as of the biology and oncopathology of the human adult testis. Apart from practical implications for the assessment of proliferation and oncogenic aberrations in human tissues and tumours, this study may inspire further research into the emerging role of the cyclin D proteins in the establishment and/or maintenance of the differentiated phenotypes.

Unique expression patterns of H19 in human testicular cancers of different etiology.

The expression pattern of the imprinted human H19 gene was investigated in testicular cancers of different etiology, as well as in normal testicular parenchyma, parenchyma without germ cells, and adjacent to testicular germ cell tumors of adolescents and adults (TGCTs), using RNase protection analysis, mRNA in situ hybridization and reverse-transcription polymerase chain reaction. While different total expression levels were detected in spermatocytic seminomas, lymphomas, a Sertoli cell tumor and Leydig cell tumors, none showed a disturbance of monoallelic expression. Strikingly, the majority of invasive TGCTs revealed expression of both parental alleles. The total level of expression highly correlated with differentiation lineage and stage of maturation, similar to that as reported during early normal embryogenesis. Biallelic expression could also be determined specifically in testis parenchyma containing the preinvasive lesion of this cancer. We therefore conclude that within the adult testis, biallelic H19 expression is specific for TGCTs, and that the level of expression is dependent on differentiation lineage and maturation stage. This is in agreement with the proposed primordial germ cell-origin of this cancer, and might be related to retention of embryonic characteristics in TGCTs. In addition, our data argue against H19 being a tumor suppressor gene.

Silibinin protects against cisplatin-induced nephrotoxicity without compromising cisplatin or ifosfamide anti-tumour activity.

Cisplatin is one of the most active cytotoxic agents in the treatment of testicular cancer, but its clinical use is associated with side-effects such as ototoxicity, neurotoxicity and nephrotoxicity. Long-term kidney damage from cisplatin particularly affects the proximal tubular apparatus and can be detected by increased urinary excretion of brush-border enzymes, such as L-alanine-aminopeptidase (AAP), and magnesium. In the current study, the flavonoid silibinin was used as a nephroprotectant for cisplatin-induced nephropathy in a rat animal model. Infusion of silibinin before cisplatin results in a significant decrease in glomerular (indicated by creatinine clearance and serum urea level) and tubular kidney toxicity (excretion of brush-border enzymes and magnesium). Silibinin given alone had no effect on renal function. In order to exclude an inhibition of the anti-tumour activity of cisplatin and 4-hydroperoxy-ifosfamide by co-administration of silibinin, in vitro studies were performed in three established human testicular cancer cell lines. Dose-response curves for cisplatin (3-30 000 nmol) combined with non-toxic silibinin doses (7.25 x 10(-6) or 7.25 x 10(-5) mol l-1) did not deviate significantly from those of cisplatin alone as measured by relative cell survival during a 5 day assay using the sulphorhodamine-B staining technique. Also silibinin did not influence the cytotoxic activity of 4-hydroperoxy-ifosfamide (30-10 000 nmol) in vitro. In summary, these in vitro data rule out a significant inhibition of the anti-tumour activity of the major nephrotoxic components, cisplatin and 4-hydroperoxy-ifosfamide, by co-administration of silibinin in a human germ cell tumour cell line model. Together with these demonstrated cytoprotection effects in the rat animal model, these data form the basis for a randomised clinical trial of silibinin for the protection of cisplatin-associated nephrotoxicity in patients with testicular cancer.

Author reply

CancerVolume 78, Issue 1 p. 180-181 CorrespondenceFree Access Author reply Fu-Shing Liu M.D., Corresponding Author Fu-Shing Liu M.D. Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung, Taiwan, RepublicDepartment of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung, Taiwan, Republic===Search for more papers by this author Fu-Shing Liu M.D., Corresponding Author Fu-Shing Liu M.D. Department of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung, Taiwan, RepublicDepartment of Obstetrics and Gynecology, Taichung Veterans General Hospital, Taichung, Taiwan, Republic===Search for more papers by this author First published: 1 July 1996 https://doi.org/10.1002/(SICI)1097-0142(19960701)78:1<180::AID-CNCR27>3.0.CO;2-VAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1 Liu F-S, Ho ES-C, Chen J-T, Shih RT-P, Yang C-H, Shih A. Overexpression or mutation of the p53 tumor suppressor gene does not occur in malignant ovarian germ cell tumors. Cancer 1995; 76: 291– 5. 2 Dietl J, Horny H-P, Kaiserling E. Frequent overexpression of p53 in dysgerminoma of the ovary. Gynecol Obstet Invest 1994; 37: 141– 2. 3 Terada T, Shimizu K, Izumi R, Nakanuma Y. Methods in pathology. p53 expression in formalin-fixed, paraffin-embedded archival specimens of intrahepatic cholangiocarcinoma: retrieval of p53 antigenicity by microwave oven heating of tissue sections. Mod Pathol 1994; 7: 249– 52. 4 Inoue M, Fujita M, Enomoto T, Morimoto H, Monden T, Shimano T. Immunohistochemical analysis of p53 in gynecologic tumors. Am J Clin Pathol 1994; 102: 665– 70. 5 Bartkova J, Bartek J, Lukas J, Vojtesek B, Staskova Z, Rejthar A, et al. p53 protein alterations in human testicular cancer including pre-invasive intratubular germ-cell neoplasia. Int J Cancer 1991; 49: 196– 202. 6 Heimdal K, Lothe RA, Lystad S, Holm R, Fossa SD, Borresen AL. No germline TP53 mutations detected in familial and bilateral testicular cancer. Genes Chromosom Cancer 1993; 6: 92– 7. Volume78, Issue11 July 1996Pages 180-181 ReferencesRelatedInformation

446 Enhanced expression of c-myc, N-myc, c-Ha-ras 1, c-erb B-2/neu, c-fos and c-jun in human germ cell tumors

The presence of c-myc, N-myc, c-Ha-ras 1, c-erb B-2/neu, c-fos, and c-jun was investigated in biopsy specimens from 20 patients with various types of germ cell tumors. The expression of the oncogenes was demonstrated by in situ hybridization. C-myc oncogene expression was found in 10/20 of tumors including 2 embryonal carcinomas, in one Leydig cell tumor, in 3 embryonal carcinomas with seminomas, in one immature teratoma with seminoma, in one immature teratoma with choriocarcinoma, in one embryonal carcinoma with immature teratoma, and in one mature teratoma. N-myc was observed in 8/20 of tumors including 2 embryonal carcinomas, in 3 embryonal carcinomas with seminomas, in one embryonal carcinoma with immature teratoma, in one immature teratoma with choriocarcinoma, and one immature teratoma with seminoma. C-Ha-ras 1 oncogene expression was found in 7/20 tumors including 2 embryonal carcinomas, in one mature teratoma, in the benign Leydig cell tumor, in 2 embryonal carcinomas with seminomas, and in one embryonal carcinoma with immature teratoma. Expression of c-erb B-2/neu oncogene could be identified in benign Leydig cell tumor only. C-fos was expressed in 12/20 tumors including in the benign Leydig cell tumor, in 4 pure seminomas, in 3 embryonal carcinomas with seminomas, in 2 immature teratomas, and in one immature teratoma with choriocarcinoma. C-jun expression was observed in 14/20 tumors, including in 6 pure seminomas, in the benign Leydig cell tumor, in 2 immature teratomas, in one mature teratoma, in 2 embryonal carcinomas with seminomas, in one immature teratoma with choriocarcinoma, and in one embryonal carcinoma with immature teratoma. The evidence of these oncogenes in human testicular cancer is consistent with the view, that alterations of these oncogenes playa role in the pathogenesis of this tumor type.

ANTITUMOR-ACTIVITY AND TOXICITY OF CONTINUOUS-INFUSION VERSUS BOLUS ADMINISTRATION OF BLEOMYCIN IN 2 HETEROTRANSPLANTED HUMAN TESTICULAR CANCER CELL-LINES

The continuous infusion of the glycopeptide antibiotic cytotoxic agent bleomycin in comparison to bolus application has been postulated to be associated with increased antitumour activity and decreased toxicity, particularly pulmonary fibrosis. In the treatment of patients with testicular cancer, bleomycin is an essential agent and is currently used in continuous infusion and bolus application schedules in cisplatin-based combination therapy regimens. The current study addresses the antitumour activity and general toxicity of bleomycin given as continuous intraperitoneal infusion versus bolus application in human testicular cancer cell lines heterotransplanted into nude mice. Maximally tolerated doses for each administration route, defined as being the LD20 were applied (8.7 or 17.5 mg/kg days 1-7 continuous intraperitoneal infusion via osmotic mini pump or 40 mg/kg intraperitoneal bolus application on days 1, 5, 9). Bleomycin demonstrated antitumour efficacy at all concentrations used in comparison to untreated controls. There was no significant difference in antitumour activity between continuous or bolus application of bleomycin when the same cumulative doses were compared. Neither was there any difference with respect to bleomycin toxicity with 11 +/- 4 or 12 +/- 5% losses of body weight for continuous infusion regimens compared to 13 +/- 3% for bolus application. In a small subgroup of mice histological examination of the lungs demonstrated no signs of pulmonary fibrosis. In summary, using an established testicular cancer xenograft model in nude mice bolus application of bleomycin was as active as continuous infusion of this drug with no apparent difference in overall toxicity. Current standard treatment regimens using bolus application of bleomycin should not be altered without necessary reasons. Bleomycin pulmonary toxicity needs to be studied in clinical trials taking into account possible drug interactions in combination chemotherapy regimens and additional risk factors for pulmonary toxicity.