Live attenuated VZV vaccination induces antitumor immunity in ATLL patients.

Adult T cell leukemia/lymphoma (ATLL) is a CD4-positive peripheral T cell lymphoma caused by human T cell lymphotropic virus type 1 (HTLV-1). Although ATLL is quite difficult to be cured, up-regulation of cellular immunity such as HTLV-1 Tax-specific cytotoxic T lymphocytes (CTLs) has been proved to be important to obtain long-term survival. At present, no efficacious method to activate ATLL-specific cellular immunity is available. This study aimed to investigate whether live attenuated varicella-zoster virus (VZV) vaccination to ATLL can activate HTLV-1 Tax-specific cellular immune response. A total of 3 indolent- and 3 aggressive-type ATLL patients were enrolled. All aggressive-type patients had the VZV vaccination after completing anti-ATLL treatment including mogamulizumab, which is a monoclonal antibody for C-C chemokine receptor 4 antigen, plus combination chemotherapy, whereas all indolent-type patients had the VZV vaccination without any antitumor treatment. Cellular immune responses including Tax-specific CTLs were analyzed at several time points of pre- and post-VZV vaccination. After the VZV vaccination, a moderate increase in 1 of 3 indolent-type patients and obvious increase in all 3 aggressive-type patients in Tax-specific CTLs percentage were observed. The increase in the cell-mediated immunity against VZV was observed in all indolent- and aggressive-type patients after VZV vaccination. To conclude, VZV vaccination to aggressive-type ATLL patients after mogamulizumab plus chemotherapy led to the up-regulation of HTLV-1 Tax-specific CTLs without any adverse event. Suppression of regulatory T lymphocytes by mogamulizumab may have contributed to increase tumor immunity in aggressive-type ATLL patients. Japan Registry of Clinical Trials number, jRCTs051180107.

HTLV-1 Tax-specific memory cytotoxic T lymphocytes in long-term survivors of aggressive-type adult T-cell leukemia/lymphoma.

PURPOSE: Adult T-cell leukemia/lymphoma (ATLL) is a relatively refractory peripheral T-cell lymphoma caused by human T-cell lymphotropic virus type 1 (HTLV-1). The objective of this study was to investigate the characteristics of long-term survivors with ATLL. METHODS: We conducted an observational study of 75 aggressive-type ATLL patients. Flow cytometry was conducted to analyze HTLV-1 Tax-specific cytotoxic T-lymphocytes (CTLs) and T-cell receptor Vß gene repertoire. RESULTS: We first evaluated six long-term survivors among 37 patients who were newly diagnosed with ATLL and then treated with intensive chemotherapy without mogamulizumab, a monoclonal antibody for C-C chemokine receptor four antigen. Reversal of the CD4-to-CD8 ratio (CD4/CD8) in peripheral mononuclear cells was observed in all six patients. Three of these six patients showed reversed CD4/CD8 immediately after herpes virus infection. Four of these six patients who could be examined demonstrated long-term maintenance of HTLV-1 Tax-specific CTLs. We subsequently identified four long-term survivors among 38 patients who were newly diagnosed with ATLL and then treated with intensive chemotherapy plus mogamulizumab. All four patients showed reversed CD4/CD8, and three of the four patients contracted herpes virus infection during immunochemotherapy. Six of the total 10 patients were subjected to CTL analyses. Tax-specific CTLs were observed, and the CTLs that were almost entirely composed of memory CTLs in all patients were recorded. HTLV-1 provirus was also detected in all six patients. CONCLUSIONS: These data suggest that Tax-specific memory CTLs probably, together with anticancer agents, eradicate ATLL cells and exhibit long-term preventive effects from relapse ATLL. Thus, the strong activation of cellular immunity, such as herpes virus infection, seems to be necessary to induce such a potent number of Tax-specific CTLs.

Clonal Upregulation of Effector Cytotoxic T Lymphocytes in a Patient with Multiple Tyrosine Kinase Inhibitor-Refractory Chronic Myeloid Leukemia with Long-Term Survival.

We present the case of a patient with multiple tyrosine kinase inhibitor (TKI)-refractory chronic phase chronic myeloid leukemia (CP-CML) with a T315I mutation of abl1. Dasatinib, a second-generation TKI, was administered as the initial treatment but achieved neither a cytogenetic nor molecular response. A mutational analysis of abl1 revealed that the patient had a T315I mutation. The patient was then administered ponatinib, a third-generation TKI, which is thought to be effective against T315I; however, the complete blood counts became within normal limits, and neither a cytogenetic nor molecular response was achieved. However, the patient has maintained a healthy chronic phase (with no blast crises) for more than 5½ years since the diagnosis of CP-CML. T-cell receptor (TCR) repertoire analyses using peripheral blood revealed a remarkable clonal expansion of effector cytotoxic T lymphocytes (CTLs) that contained TCR V beta 13.6. We observed the clonal expansion of naïve CTLs with TCR V beta 13.6; however, no clonality was observed in the memory CTLs. The naïve and effector CTLs persisted at very high percentages since the seventh month after starting dasatinib. The CTLs could not have led to the molecular response; therefore, there might be plenty of CML stem cells remaining in the bone marrow. Therefore, although the CTLs might have prevented the disease from developing blast crises over more than 5 years, the CTLs might not have been able to become memory CTLs.

Efficacy and Cardiovascular Adverse Events of Long-term Treatment with Tyrosine Kinase Inhibitors for Chronic Myeloid Leukemia: A Report from the Nagasaki CML Study Group.

Objective The standard treatment for chronic myeloid leukemia (CML) is the continuous use of tyrosine kinase inhibitors (TKIs), which results in a favorable prognosis for the majority of patients. Recent studies have identified cardiovascular diseases (CVDs) as late adverse events (AEs) related to TKIs. In this study, we evaluated the long-term efficacy and AEs of TKIs, focusing on CVDs. Methods We performed a retrospective survey of CML patients (diagnosed from 2001 to 2016) treated with TKIs in Nagasaki Prefecture. Clinical data were obtained from their medical records. We analyzed the survival, estimated cumulative incidence of CVDs, and risk factors for CVD among CML patients treated with TKIs. Results The overall survival rate of 264 CML patients treated with TKIs (median age 58 years old) was 89.6% [95% confidence interval (CI), 84.9-92.9%], and 80.5% (95% CI, 73.4-85.9%) at 5 and 10 years after the CML diagnosis, respectively. CVD events occurred in 26 patients (9.8%, median age 67.5 years old) with a median 65.5 months of TKI treatment. The cumulative incidences at 2 and 5 years was 2.4% (95% CI, 1.0-4.8%) and 5.2% (95% CI, 2.8-8.6%), respectively. Hypertension and a high SCORE chart risk at the diagnosis of CML were associated with CVD events during TKI treatment. Conclusion TKI treatment contributed to the long-term survival of CML patients in Nagasaki Prefecture in a "real-world" setting, but the incidence of CVDs seemed to be increased in these patients. A proper approach to managing risk factors for CVD is warranted to reduce CVD events during TKI treatment.

Induction of Effector and Memory Cellular Immunity in a Patient with Long-Term Complete Molecular Response to Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia.

This case report is about a patient who suffered from Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukemia. The blasts were positive for myeloid-lineage markers including CD13 and CD33, as well as B-cell-lineage markers. Minor bcr-abl1 mRNA was detected by real-time quantitative polymerase chain reaction. Chromosomal abnormality monosomy 7 was also observed, in addition to Ph1. Despite treatment difficulties that were anticipated based on these findings, the patient had long-time complete molecular response (CMR) for approximately 5 years using chemotherapy and two tyrosine kinase inhibitors, imatinib and dasatinib. Lymphocytes were elevated after the patient switched from imatinib to dasatinib, and a T-cell receptor (TCR) V beta gene repertoire analysis revealed oligoclonal expansion of effector and memory cytotoxic T lymphocytes (CTLs), including Wilms tumor 1-specific CTLs. More specifically, the two memory CTLs expressing TCR V beta 3 and V beta 7.1 gradually increased after dasatinib administration. The activation and maintenance of anti-leukemia immunity may have allowed the patient to obtain long-time CMR. These results highlight that obtaining memory CTLs for leukemia cells may lead to safe withdrawal from dasatinib in the patient.

Mogamulizumab Plus EPOCH Therapy for Patients With Newly Diagnosed Aggressive Adult T-cell Leukemia/lymphoma.

BACKGROUND/AIM: Adult T-cell leukemia/lymphoma (ATLL) is a relatively refractory CD4-positive peripheral T-cell lymphoma. VCAP-AMP-VECP (mLSG15) is one of the standard chemotherapeutic regimens for patients with aggressive ATLL. Mogamulizumab (moga), a monoclonal antibody for C-C chemokine receptor 4 antigen expressed on the cell surface, has recently been poised for use as monotherapy and in combination with chemotherapy. However, to date, a significant survival benefit has not been obtained with the combination of moga + mLSG15 therapy. PATIENTS AND METHODS: We retrospectively analyzed 77 patients diagnosed with aggressive ATLL. Of them, 22 were treated with moga + a chemotherapy regimen comprised of etoposide, vincristine, doxorubicin, cyclophosphamide, and prednisolone (EPOCH), 16 with moga + mLSG15, and 39 with chemotherapy alone. RESULTS: A risk reduction of approximately 30% was obtained with moga + EPOCH compared with moga + mLSG15. CONCLUSION: The addition of moga to chemotherapy did not result in a survival benefit compared with chemotherapy alone. However, a statistically significant overall survival benefit was observed in patients with moga-induced skin disorders.

Elevation of Memory Cytotoxic T Lymphocytes, Including Human T Lymphotropic Virus Type 1 Tax-Specific and Hepatitis Virus Type C-Specific Cytotoxic T Lymphocytes, in a Patient with Adult T-Cell Leukemia/Lymphoma and Hepatocellular Carcinoma.

Herein, we present the case of a patient who suffered from adult T-cell leukemia/lymphoma (ATLL) and hepatocellular carcinoma (HCC) after obtaining a sustained virological response following treatment with a direct-acting antiviral (DAA) at different points in time. The patient went into complete remission (CR) for ATLL. Unfortunately, subsequent relapse of ATLL was observed. This situation was overcome using chemotherapy with pegylated interferon alpha-2b. Human T lymphotropic virus type 1 Tax-specific cytotoxic T lymphocytes (CTLs) were recognized after obtaining second CR, and those CTLs have been maintained for many years. After 4 years from the second CR, chronic hepatitis type C was treated with a DAA, and sustained virological response was attained. However, the occurrence of HCC was detected. Surprisingly, the tumor disappeared spontaneously. Hepatitis virus type C-specific CTLs were also detected in the patient. T-cell receptor (TCR) V beta gene repertoire analyses revealed oligoclonal expansion of effector and memory CTLs. The number of CTLs expressing the TCR V beta 13.1 has increased over the years since HCC occurrence. The activation and maintenance of anticancer cellular immunity may have allowed the patient to obtain long-term survival and overcome two lethal neoplasms.

No clear survival benefit of azacitidine for lower-risk myelodysplastic syndromes: A retrospective study of Nagasaki.

The efficacy of azacitidine (AZA) on survival of lower risk (LR) - myelodysplastic syndromes (MDS) is controversial. To address this issue, we retrospectively evaluated the long-term survival benefit of AZA for patients with LR-MDS defined by International Prognostic Scoring System (IPSS). Using data from 489 patients with LR-MDS in Nagasaki, hematologic responses according to International Working Group 2006 and overall survival (OS) were compared among patients that received best supportive care (BSC), immunosuppressive therapy (IST), erythropoiesis-stimulating agents (ESA), and AZA. Patients treated with AZA showed complete remission (CR) rate at 11.3%, marrow CR at 1.9%, and any hematologic improvement at 34.0%, with transfusion independence (TI) of red blood cells in 27.3% of patients. and platelet in 20% of patients, respectively. Median OS for patients received IST, ESA, BSC, and AZA (not reached, 91 months, 58 months, and 29 months, respectively) differed significantly (P < .001). Infection-related severe adverse events were observed in more than 20% of patients treated with AZA. Multivariate analysis showed age, sex, IPSS score at diagnosis, and transfusion dependence were significant for OS, but AZA treatment was not, which maintained even response to AZA, and IPSS risk status at AZA administration was added as factors. We could not find significant survival benefit of AZA treatment for LR-MDS patients.

Successful Treatment of a Patient with Brentuximab Vedotin-Refractory ALK-Negative Anaplastic Large Cell Lymphoma with Romidepsin.

We present the case of a 78-year-old male patient who was diagnosed with anaplastic lymphoma kinase (ALK)-negative, CC chemokine receptor 4 (CCR4)-negative, and CD30-positive anaplastic large cell lymphoma (ALCL). The patient had a past medical history of adult T-cell leukemia/lymphoma and colon cancers that had developed simultaneously approximately 2 years prior to the development of ALCL that were treated with immunochemotherapy and resection, respectively. Initial treatment for ALCL included brentuximab vedotin, an anti-CD30 monoclonal antibody-monomethyl auristatin E conjugate; however, we were unable to achieve a sufficient treatment effect. Romidepsin, an oral histone deacetylase inhibitor, was introduced as salvage chemotherapy; complete remission was attained. Interestingly, a reversal of the CD4/CD8 ratio and a reduction in human T-lymphotropic virus type 1 (HTLV-1) virus load was observed after 2 cycles of immunochemotherapy; the patient experienced upregulation of HTLV-1 Tax-specific cytotoxic T lymphocytes after a herpes zoster infection and the completion of immunotherapy. The immunologic status was maintained from the time of diagnosis through the completion of romidepsin therapy. Our findings indicate that romidepsin can be used safely and effectively to treat ALCL without impairing cellular immunity to HTLV-1.

Genome analysis of myelodysplastic syndromes among atomic bomb survivors in Nagasaki.

Ionizing radiation is a risk factor for myeloid neoplasms including myelodysplastic syndromes (MDS), and atomic bomb survivors have been shown to have a significantly higher risk of MDS. Our previous analyses demonstrated that MDS among these survivors had a significantly higher frequency of complex karyotypes and structural alterations of chromosomes 3, 8, and 11. However, there was no difference in the median survival time between MDS among survivors compared with those of de novo origin. This suggested that a different pathophysiology may underlie the causative genetic aberrations for those among survivors. In this study, we performed genome analyses of MDS among survivors and found that proximally exposed patients had significantly fewer mutations in genes such as TET2 along the DNA methylation pathways, and they had a significantly higher rate of 11q deletions. Among the genes located in the deleted portion of chromosome 11, alterations of ATM were significantly more frequent in proximally exposed group with mutations identified on the remaining allele in 2 out of 5 cases. TP53, which is frequently mutated in therapy-related myeloid neoplasms, was equally affected between proximally and distally exposed patients. These results suggested that the genetic aberration profiles in MDS among atomic bomb survivors differed from those in therapy-related and de novo origin. Considering the role of ATM in DNA damage response after radiation exposure, further studies are warranted to elucidate how 11q deletion and aberrations of ATM contribute to the pathogenesis of MDS after radiation exposure.

[A case of secondary central nervous system lymphoma presenting marked hypoglycorrhachia].

A 67-year-old male was transferred to our hospital with diplopia, decreased deep tendon reflex and ataxia. He had been suspected Fisher syndrome because of previous upper respiratory tract infection. A cerebrospinal fluid examination showed marked hypoglycorrhachia, pleocytosis and elevated protein, and cytological examination suggested malignant lymphoma. Abdominal computed tomography revealed a left adrenal mass. A biopsy of the left adrenal mass revealed diffuse large B-cell lymphoma. He was treated with a combination of R-CHOP (rituximab, cyclophosphamide, doxorubicin hydrochloride, oncovin and prednisolone) and intrathecal administration of methotrexate, cytarabine and prednisolone. Neurological symptoms were gradually improved. Malignancy should be considered in addition to bacterial, fungal or tuberculous meningitis in a case with marked hypoglycorrhachia.

Chromosomal analysis of myelodysplastic syndromes among atomic bomb survivors in Nagasaki.

The myelodysplastic syndromes (MDS) are clonal haematopoietic disorders that develop de novo and also secondary to chemotherapy and/or radiation therapy. We previously demonstrated that the risk of MDS is increased among atomic bomb survivors with significant correlation to radiation dose; however, the clinical characteristics of these survivors have not been well analysed. In this study, we investigated chromosomal abnormalities of MDS among survivors. The frequency of abnormal karyotypes was significantly higher, with more very poor risk karyotypes, according to the revised International Prognostic Scoring System, among those exposed close to the hypocentre compared with unexposed cases. However, abnormal karyotype frequency did not reflect the prognosis of exposed cases with respect to distance from the hypocentre. In addition, there was no difference in prognosis between exposed and unexposed cases. Among proximally exposed cases (<1·5 km from the hypocentre), chromosomal translocations and inversions were more frequent, and the frequency of structural alterations in chromosomes 3, 8, and 11 was significantly increased compared with unexposed cases. These results suggest that chromosomal alterations in MDS among survivors have different features compared with those in de novo or therapy-related MDS. Detailed molecular study is warranted.

The Contactless Vital Sensing System Precisely Reflects R-R Interval in Electrocardiograms of Healthy Subjects.

BACKGROUND: The aim of the present study was to investigate the validity of the contactless vital sensing system that we previously developed. METHODS: A total of 111 healthy Japanese subjects were recruited from the University of Occupational and Environmental Health and the Panasonic Corporation AVC Networks Company. All subjects underwent an evaluation using the contactless vital sensing system and electrocardiography (ECG). We compared the R-R interval obtained using the new contactless sensing system to that obtained using ECG. RESULTS: A very strong correlation was observed between the instruments. CONCLUSIONS: This result confirms the validity of the new contactless sensing system in evaluating healthy subjects.

Clinical features and prognosis of patients with myelodysplastic syndromes who were exposed to atomic bomb radiation in Nagasaki.

There is evidence that radiation exposure is a causative factor of myelodysplastic syndromes (MDS). However, little is known about whether radiation exposure is also a prognostic factor of MDS. We investigated the impact of radiation exposure on the prognosis of MDS in Nagasaki atomic bomb survivors using the International Prognostic Scoring System (IPSS) and the revised version (IPSS-R). Subjects were 140 patients with primary MDS diagnosed between 1985 and 2011 and evaluable for IPSS, IPSS-R, and exposure distance. Of those, 31 were exposed at <1.5 km, 35 at 1.5-2.99 km, and 74 at ≥3.0 km. By the end of March 2014, 47 patients (34%) progressed to overt leukemia and 106 (75.7%) died. By comparing with patients exposed at ≥3.0 km, those exposed at <1.5 km had significantly higher frequencies of abnormal chromosome (P = 0.02), intermediate/poor IPSS, and intermediate/poor/very poor IPSS-R cytogenetic category (P = 0.0001, and P < 0.0001, respectively). As with de novo MDS, multivariate Cox regression analyses revealed that cytogenetic abnormalities, IPSS karyotype, and IPSS-R cytogenetics were significantly associated with poor survival, and cumulative incidence of leukemic transformation in MDS among atomic bomb survivors, but exposure distance was not associated with any poor outcomes. These suggest that exposure to the greater dose of atomic bomb radiation is associated with developing poor cytogenetic abnormalities in MDS, which might consequently lead to overt leukemia among atomic bomb survivors.

Molecular analysis of the BCR-ABL1 kinase domain in chronic-phase chronic myelogenous leukemia treated with tyrosine kinase inhibitors in practice: study by the Nagasaki CML Study Group.

An appropriate trigger for BCR-ABL1 mutation analysis has not yet been established in unselected cohorts of chronic-phase chronic myelogenous leukemia patients. We examined 92 patients after 12 months of tyrosine kinase inhibitor (TKI) treatment in Nagasaki Prefecture, Japan. Univariate analysis revealed that significant factors associated with not attaining a major molecular response (MMR) were the presence of the minor BCR-ABL1 fusion gene, a low daily dose of TKI, and the emergence of BCR-ABL1 kinase domain mutations conferring resistance to imatinib. Factors associated with the loss of sustained MMR were a low daily dose of TKI and the emergence of alternatively spliced BCR-ABL1 mRNA with a 35-nucleotide insertion. Taken together, our results suggest that the search for BCR-ABL1 mutations should be initiated if patients have not achieved MMR following 12 months of TKI treatment.

Two Cases of Cerebral Involvement in Malignant Lymphoma (CD20+) That Responded to Combination Therapy with Rituximab and Cladribine.

Cerebral involvement frequently occurs in association with progression or relapse of malignant lymphoma. Chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone, the standard chemotherapy for malignant lymphoma, is an ineffective treatment for cerebral involvement because these drugs cannot cross the blood-brain barrier. Therefore, various alternative strategies have been attempted. Although high-dose methotrexate combined with whole-brain radiotherapy is widely used to treat primary central nervous system lymphoma, there is no standard therapy to treat cerebral involvement in malignant lymphoma. Furthermore, high-dose methotrexate in combination with whole-brain radiotherapy is not always effective, and high rates of neurotoxicity are often observed, particularly in the elderly. To expand the therapeutic options for central nervous system involvement in recent years, systemic chemotherapies, including rituximab, high-dose methotrexate, and other agents that act during the S, G2, and M phases of the cell cycle, have been attempted. In our hospital, cladribine, a purine analogue with a cytocidal effect on resting malignant cells (G0/G1 phase of the cell cycle), has been used in combination with rituximab, which exhibits antitumor effects on nodal and extranodal lesions of relapsed and/or refractory B cell lymphomas, particularly cerebral lesions. Here, we report 2 representative cases of patients who were treated with cladribine plus rituximab and survived for 30 months (died of sepsis) and 52 months (still alive), respectively. The outcomes of these cases suggest that cladribine plus rituximab combination therapy with whole-brain radiotherapy may be very useful as salvage therapy for secondary central nervous system lymphoma and as initial therapy for primary central nervous system lymphoma.

Simulation of the toxicokinetics of trichloroethylene, methylene chloride, styrene and n-hexane by a toxicokinetics/toxicodynamics model using experimental data.

The toxicokinetics/toxicodynamics (TKTD) model simulates the toxicokinetics of a chemical based on physiological data such as blood flow, tissue partition coefficients and metabolism. In this study, Andersen and Clewell's TKTD model was used with seven compartments and ten differential equations for calculating chemical balances in the compartments (Andersen and Clewell 1996, Workshop on physiologically-based pharmacokinetic/pharmacodynamic modeling and risk assessment, Aug. 5-16 at Colorado State University, U.S.A) . Using this model, the authors attempted to simulate the behavior of four chemicals: trichloroethylene, methylene chloride, styrene and n-hexane, and the results were evaluated. Simulations of the behavior of trichloroethylene taken in via inhalation and oral exposure routes were also done. The differences between simulations and measurements are due to the differences between the absorption rates of the exposure routes. By changing the absorption rates, the simulation showed agreement with the measured values. The simulations of the other three chemicals showed good results. Thus, this model is useful for simulating the behavior of chemicals for preliminary toxicity assessment.

Evaluation for reliability and feasibility of the draft protocol for the enhanced rat 28-day subacute study (OECD Guideline 407) using androgen antagonist flutamide.

As part of an international validation project to establish a test protocol for the 'Enhanced OECD Test Guideline no. 407', a 28-day repeated dose study of flutamide was performed (1) to examine which of the current and/or additional parameters can detect endocrine effects of test chemicals most reliably and sensitively, (2) to investigate whether it is actually feasible to routinely include all additional parameters into the testing routine, and (3) to assess intra-laboratory variability by performing two identical studies (experiments A and B) in parallel using groups of five animals each per dose and sex. Groups of five male and five female CD(SD)IGS rats were treated by oral gavage with 0, 1, 10 and 100 mg flutamide/kg body weight for at least 28 days. The dose level considered to be around the MTD (100 mg/kg) exerted the expected antiandrogenic effects on androgen related tissues: significant decrease of the weights of androgen dependent organs and the sperm count and increase in histopathological lesions. At the middle dose (10 mg/kg), significant decrease of prostate weight (ventral and dorso-lateral parts combined) was observed and it was suggested that weight measurement of androgen dependent organs provides the most reliable and sensitive endpoint with this protocol. As for the feasibility, because of many items in this protocol, selection should be based on the sensitivity. From our data, addition of weight measurement of androgen dependent organs to the items of the existing OECD 407 guideline might allow accurate screening for endocrine disruptors. At the dose level considered to be around the MTD, the findings achieving statistical significance in one experiment with five animals/dose/sex could be reproduced in the second experiment, and evaluation with the small groups was consistent with findings using the combined groups of 10 animals/dose/sex. The results demonstrate that the protocol can reliably detect antiandrogenic effects of flutamide.

Effects of perinatal exposure to flutamide on sex hormone responsiveness in F1 male rats.

Pregnant rats were administered flutamide (0 and 10 mg/kg, p.o.) from gestation Day 14 to post-parturition Day 3 and effects on responsiveness to androgens (testosterone propionate, TP; dihydrotestosterone, DHT) in male offspring were examined with a Hershberger assay. Male pups of each group were assigned to 6 subgroups as follows: Group 1, castration and euthanized at postnatal Day 46 (PND 46); Group 2, castration + vehicle; Group 3, castration + TP; Group 4, castration + DHT; Group 5, vehicle; Group 6, DHT. After castrations were conducted at PND 36, animals were treated with TP (2 mg/kg in corn oil, s.c.) or DHT (1.25 mg/kg in corn oil, s.c.) once a day for 10 days, beginning at PND 46. At PND 56, the following organs/tissues were removed and weighed: ventral prostate, dorso-lateral prostate, seminal vesicles with coagulating glands, levator ani muscle plus bulbocavernosus muscle, Cowper's gland, and glands penis. Analysis of serum testosterone, LH and FSH in Groups 2, 3, 4, 5 and 6, and RT-PCR using prostate tissue from Groups 2, 3 and 4 were carried out. Perinatal exposure to flutamide caused decreased weights of androgen-dependent organs. Responses to androgens were recognized in organs of all castrated groups, with increased organ weights, especially in animals administered TP where values were essentially equal to or greater than those of intact animals in both the control and the 10 mg/kg group. On the other hand, the degree of weight increase of the ventral prostate and seminal vesicles with TP or DHT treatment in castrated animals was smaller in the flutamide administration group than in the controls. In hormone assays, castrated + vehicle animals showed higher serum LH than the other groups. Serum FSH was high in the castrated groups (Group 2>Group 4>Group 3), while in the noncastrated group a constant level was noted, with or without flutamide. No effect of flutamide administration was observed regarding sex hormone. RT-PCR using ventral prostate tissue revealed no significant differences in expression of AR, C3, VEGF, TGF-beta1, beta2, KGF and CK8 mRNA after androgen treatment between the control and flutamide treatment groups. C3 mRNA was increased in androgen-treated animals, whereas AR, TGF-beta and KGF mRNAs were decreased. Perinatal exposure to anti-androgen causes irreversible abnormalities in male pups. Concerning the responsiveness to TP and DHT, the degrees of weight changes in ventral prostate and seminal vesicles in castrated animals were decreased. However, the other organ weights, the sex hormone levels and androgen-reactive gene expression in the ventral prostate were not influenced by perinatal flutamide treatment in the present study.

Effects of perinatal exposure to flutamide on sex hormones and androgen-dependent organs in F1 male rats.

Flutamide, which has antiandrogenic properties, was administered to pregnant rats, and effects on male offspring were examined. Crj: CD (SD) IGS (SPF) females were administered flutamide (0.15, 0.6, 2.5, 10.0, 100 mg/kg, p.o.) from gestation Day 14 to post parturition Day 3. The number of pups, body weights, clinical features, anogenital distance (AGD), nipple retention, testicular descent, and urogenital malformation in F1 males were examined. Hormone measurement, necropsy and histopathological examination were carried out at post-neonatal Day 4 (PND 4) and PND 60. Sperm analysis was also carried out at PND 60. Decrease in body weight was seen in the 100 mg/kg group and the AGD was decreased at 2.5 mg/kg and above. Retention of nipples, hypospadia, vaginal pouches, penis malformation, unilateral ectopic testis, and decrease of organ weights (prostate, seminal vesicles, levator ani muscle plus bulbocavernosus muscle, testis) were observed at 10 mg/kg and above. Testicular testosterone (T) was increased significantly with 100 mg/kg at PND 4 and tendencies for increase were observed in serum T, LH and FSH at 10 mg/kg and more at the same time point. In contrast, elevated levels of LH and FSH were seen with 100 mg/kg at PND 60. Histopathological examination revealed defects or hypoplastic changes of genital organs (> or = 10 mg/kg), squamous metaplasia (10 mg/kg) or mucification (100 mg/kg) of the urethral diverticulum epithelium and inflammation of genital organs (100 mg/kg). Though only undescended testes lacked spermatogenesis at 10 mg/kg, atrophic change of seminiferous tubules and azoospermia were observed in the 100 mg/kg group, despite testicular descent. Perinatal administration of flutamide affected F1 male rats at 2.5 mg/kg and above. In addition to urogenital malformation, 100 mg/kg flutamide caused high LH and FSH levels at PND 60. This study indicates that the most sensitive parameter is AGD, whereby reduction was observed at 2.5 mg/kg. A clear no-effect level (NOEL: 0.6 mg/kg) was obtained in this perinatal study of an antiandrogenic chemical.