Myositis with sarcoplasmic inclusions in Nakajo-Nishimura syndrome: a genetic inflammatory myopathy

AIMS

Nakajo-Nishimura syndrome (NNS) is an autosomal recessive disease caused by biallelic mutations in the PSMB8 gene that encodes the immunoproteasome subunit β5i. There have been only a limited number of reports on the clinicopathological features of the disease in genetically confirmed cases.

METHODS

We studied clinical and pathological features of three NNS patients who all carry the homozygous p.G201V mutations in PSMB8. Patients' muscle specimens were analysed with histology and immunohistochemistry.

RESULTS

All patients had episodes of typical periodic fever and skin rash, and later developed progressive muscle weakness and atrophy, similar to previous reports. Oral corticosteroid was used for treatment but showed no obvious efficacy. On muscle pathology, lymphocytes were present in the endomysium surrounding non-necrotic fibres, as well as in the perimysium perivascular area. Nearly all fibres strongly expressed MHC-I in the sarcolemma. In the eldest patient, there were abnormal protein aggregates in the sarcoplasm, immunoreactive to p62, TDP-43 and ubiquitin antibodies.

CONCLUSIONS

These results suggest that inflammation, inclusion pathology and aggregation of abnormal proteins underlie the progressive clinical course of the NNS pathomechanism.

Effects of Hydroxychloroquine in Patients With Cutaneous Lupus Erythematosus: A Multicenter, Double-Blind, Randomized, Parallel-Group Trial

OBJECTIVE

To assess the efficacy and tolerability of hydroxychloroquine (HCQ) in patients with cutaneous lupus erythematosus (CLE), in a phase III clinical trial conducted in Japan.

METHODS

We conducted a double-blind, randomized, parallel-group clinical trial. This was a baseline-controlled study, and the group differences were evaluated in an exploratory analysis. A total of 103 patients with active CLE (according to a Cutaneous Lupus Erythematosus Disease Area and Severity Index [CLASI] activity score of ≥4) were included. Patients were randomized 3:1 to receive HCQ or placebo during the 16-week double-blind period, and all patients were given HCQ during the following 36-week single-blind period. The primary efficacy end point was a reduction in the CLASI activity score at week 16. The secondary end points included the central photo evaluation (5-point scale), patient's global assessment (7-point scale), the Skindex-29 score, and investigator's global assessment (7-point scale, based on the other 3 secondary end points). In patients with systemic lupus erythematosus, fatigue and musculoskeletal pain were assessed. Safety was assessed up to week 55.

RESULTS

The mean CLASI score at week 16 was significantly improved from baseline in both the HCQ group and the placebo group: mean change -4.6 (95% confidence interval [95% CI] -6.1, -3.1) (P < 0.0001), and mean change -3.2 (95% CI -5.1, -1.3) (P = 0.002), respectively, without between-group difference (P = 0.197). The investigator's global assessment demonstrated a greater proportion of "improved" and "remarkably improved" patients in the HCQ group (51.4% versus 8.7% in the placebo group [P = 0.0002 between groups]). The other secondary end points supported the efficacy of HCQ. Cellulitis, drug eruption, hepatic dysfunction, and Stevens-Johnson syndrome were shown to be serious adverse events related to HCQ use.

CONCLUSION

The results of this randomized clinical trial support the efficacy and tolerability of HCQ in patients with CLE.

Non-invasive quantification of melanin in the stratum corneum: a novel indicator of skin lesions in pigmentation diseases

BACKGROUND/PURPOSE

Skin melanin content is an important indicator for ascertaining the pathology of skin pigmentation diseases, but its analysis necessitates a biopsy or other means of collecting tissue, posing a considerable burden to the patient, and making it difficult to observe how a given skin site changes over time. Here, we aimed to establish a non-invasive method for quantifying the eumelanin and pheomelanin content of the stratum corneum.

METHODS

Sun-exposed and non-exposed samples from 10 healthy Japanese subjects were compared. We harvested the outermost layer of the stratum corneum by tape-stripping, considering the outer side of the forearm as a sun-exposed area, and medial side of the upper arm as a non-exposed area. Four additional subjects were included in the analysis of change in melanin content over time at the same skin site. The anterior lower leg received a single exposure to two minimal erythema dose sunlight, and the stratum corneum was harvested from the same site over a period of 20 weeks; we subsequently quantified the levels of eumelanin and pheomelanin using high-performance liquid chromatography.

RESULTS

We were able to accurately quantify the eumelanin and pheomelanin contents of the stratum corneum, and to observe the evolution of the same skin site over time. Eumelanin levels were significantly higher in the sun-exposed area, with a peak in melanin observed after 11-15 weeks of sun exposure.

CONCLUSION

This non-invasive method can serve as a marker for pathology of skin pigmentation diseases such as malignant tumors.

Sequential Alteration of Apoptosis, p53 Expression, and Cell Proliferation in the Rat Pancreas Treated with 4-Hydroxyaminoquinoline 1-Oxide

Changes in p53 expression, apoptosis and cell proliferation after treatment with 4-hydroxyaminoquinoline 1-oxide (4HAQO) were investigated in the rat pancreas and liver, target and nontarget organs for tumorigenesis, respectively. Male rats were given a single intravenous injection of 4HAQO at a dose of 20 mg/kg body weight and control rats received vehicle alone and were euthanized after 2—72 hours. Pancreata and livers were removed for histopathological examination, immunohistochemistry for p53 protein, PCNA and Ki-67, and TUNEL labeling and electron microscopic observation for detecting apoptosis. In the pancreas, p53 expression and apoptosis were significantly increased first at 4 and 6 hours, respectively, while no change was evident in the liver. The rates peaked at 24 hours, consistent with the peak for PCNA-labeling, while Ki-67-labeling rates peaked at 72 hours. Electron microscopically, apoptotic changes in pancreatic acinar cells were observed after 2 hours. No significant apoptosis, p53 expression or cell proliferation were noted in the pancreatic tissues of the control rats nor in liver cells regardless of 4HAQO treatment. Taken together with our previous data, the results suggest that apoptosis, p53 expression, and enhanced cell replication are closely related phenomena involved in the carcinogenesis of 4HAQO following DNA adduct formation.

The effects of vitamin A derivative etretinate on the skin of MRL mice

MRL/Mp-lpr/lpr (MRL/lpr) mice are characterized by the disorder of apoptosis due to defects in Fas antigens and autoimmune symptoms including spontaneous lupus erythematosus (LE)-like skin lesions. MRL/Mp- +/+ (MRL/n) mice do not carry the defect of lpr mutation nor do they exhibit skin disorders during the first six months of life. Retinoids are known to inhibit the proliferation of skin fibroblasts, collagen synthesis, modulate immune responses, and apoptosis by Fas ligand upregulation in skin fibroblasts. We examined changes in dermal thickness and appearance of skin disorders in five months old MRL/lpr mice by oral treatment with etretinate, a retinoic acid derivative. Etretinate treated MRL/lpr mice did not have skin lesions or dermatopathological characteristics including an increase in cells infiltrating the dermis. The mean dermal thickness of MRL/lpr and MRL/n mice treated with etretinate decreased significantly and apoptotic cells density in the dermis of MRL/lpr mice with etretinate was significantly higher compared with the control group (P, 0.05) although MRL/lpr mice have a defect within the Fas antigen. We assumed that etretinate reduced dermal thickness, and suppressed the appearance of skin lesions by inducting apoptosis and perhaps regulation of cytokine expression.

Effects of N-Acetylcysteine, Quercetin, and Phytic Acid on Spontaneous Hepatic and Renal Lesions in LEC Rats

The effects of anti-oxidants were examined in Long-Evans Cinnamon (LEC) rats, which develop acute hepatic injury, and subsequent hepatic and renal tumors due to accumulation of excess Cu. The rats, at the age of 15 weeks, were supplied a diet containing either 1% of N-acetylcysteine (NAC), quercetin (QC), or phytic acid (PA), or basal diet alone. At weeks 2 and 6 posttreatment, animals were sacrificed for collection of blood and tissue samples. In the NAC-treated group, the development of hepatic and renal lesions was dramatically reduced. In addition, accumulation of Cu and Fe in the liver was suppressed. Acrolein-modified protein, a new marker for lipid peroxidation, was not detected in the liver or kidney of NAC treated rats, even though deposition was evident in control. Neither QC nor PA affected the development of spontaneous hepatic lesions. These results indicate that oxidative stress was reduced by NAC in the liver and kidney, and suggest that Cu and Fe may be involved in the generation of oxidative stress in the liver. In addition, it was suggested that the different effects of the anti-oxidants on lesion development in LEC rats might be related to different mechanisms of action with regard to oxidative stress.

Interstitial granulomatous dermatitis demonstrating small, discrete skin-colored papules

We report the case of a 67-year-old female with a rare variant of interstitial granulomatous dermatitis showing multiple skin-colored papules. Clinically, numerous skin-colored or reddish papules were distributed on her back and posterior thighs with itchy scaly erythema on the upper back. After topical steroid application, skin-colored papules still remained after the disappearance of itchy scaly erythema. Histopathologically, perivascular and interstitial infiltration of lymphocytes and histiocytes with occasional multinucleated giant cells were observed in the superficial and mid reticular dermis, accompanied by mild mucin deposition. Interstitial granulomatous dermatitis is similar to interstitial granuloma annulare, but can be differentiated from it by lesser degrees of collagen degeneration with mucin deposition and frequent association with arthritis or rheumatic diseases. As previously reported, multiple asymptomatic skin-colored papules are considered a rare but distinct variant of interstitial granulomatous dermatitis. Although no apparent underlying disorder has developed in the presented case, careful follow-up needs to be continued.

Treatment of cutaneous lupus erythematosus: current practice variations

The treatment of cutaneous lupus erythematous (CLE) remains a challenge. Most of the therapeutic options used in CLE have not been tested in randomized controlled studies and to date no agent has been approved. Therefore, CLE treatment is mostly based on personal experience. To better characterize therapeutic habits among physicians treating CLE patients, a questionnaire-based study about various aspects of topical and systemic treatment for CLE has been performed. The questionnaire was distributed among CLE experts, mostly from Japan, the USA, and Europe. A total of 82 completed questionnaires were assessed. High-potent and potent corticosteroids as well as calcineurin inhibitors were the most often recommended topical treatment for all CLE subtypes. The most relevant factors for initiation of systemic therapy were severity of skin lesions, concomitant involvement of internal organs, CLE subtype and lack of response to topical therapies. Corticosteroids and antimalarials were considered as the most suitable and effective systemic drugs for CLE patients. However, significant differences were observed between various CLE subtypes and between different countries regarding the assessment of various topical and systemic treatment options. In conclusion, great variability of obtained answers underlines the need of development of CLE treatment guidelines suitable for different disease subtypes.

Promotion of liver and kidney carcinogenesis by ethyl tertiary-butyl ether (ETBE) in male Wistar rats

Tumor-promoting effects of ethyl tertiary-butyl ether (ETBE) were investigated in a 2-stage carcinogenesis bioassay with regard to hepatic and renal carcinogenesis in rats. Male 6-week-old Wistar rats were given drinking water containing N-ethyl-N-(2-hydroxyethyl)nitrosamine (EHEN), as an initiator, at a dose of 500 ppm for 2 weeks. Starting one week thereafter, the animals were administered ETBE at dose levels of 0 (control), 100, 300, 500 or 1,000 mg/kg/day by gavage for 19 weeks from week 4 to 22. Necropsy of all rats was performed at week 23, and livers and kidneys were examined histopathologically. Incidences of hepatocellular adenomas, and those of combined hepatocellular adenomas and carcinomas were significantly elevated in rats given 1,000 mg/kg/day ETBE, but not 100‒500 mg/kg/day ETBE, and there was a significant increase in the average numbers of lesions. No significant differences in incidences and average numbers of renal tubule neoplasms were found in rats administered 100‒1,000 mg/kg/day ETBE. However, the average numbers of atypical tubule hyperplasias, considered to be preneoplastic lesions, were significantly increased in rats given ETBE at 1,000 mg/kg/day, but not in rats given 500 mg/kg/day or lower doses. Thus, these results imply that ETBE has hepatic and renal tumor-promoting activities that affect EHEN-induced carcinogenesis in male rats, and the no-observed-effect level is 500 mg/kg/day under the present experimental conditions.

Redefining cutaneous lupus erythematosus: a proposed international consensus approach and results of a preliminary questionnaire

There is currently no uniform definition of cutaneous lupus erythematosus (CLE) upon which to base a study population for observational and interventional trials. A preliminary questionnaire was derived from and sent to a panel of CLE experts which demonstrated consensus agreement that (1) there is a need for new definitions for CLE (2) CLE is distinct from systemic lupus erythematosus and that a CLE grouping scheme should remain apart from current systemic lupus erythematosus schema (3) current CLE grouping schemes are inadequate around communication, prognostic information and to meet the needs of researchers, clinicians, patients and payers.

Promotion of liver and kidney carcinogenesis by ethyl tertiary-butyl ether (ETBE) in male Wistar rats

Tumor-promoting effects of ethyl tertiary-butyl ether (ETBE) were investigated in a 2-stage carcinogenesis bioassay with regard to hepatic and renal carcinogenesis in rats. Male 6-week-old Wistar rats were given drinking water containing N-ethyl-N-(2-hydroxyethyl)nitrosamine (EHEN), as an initiator, at a dose of 500 ppm for 2 weeks. Starting one week thereafter, the animals were administered ETBE at dose levels of 0 (control), 100, 300, 500 or 1,000 mg/kg/day by gavage for 19 weeks from week 4 to 22. Necropsy of all rats was performed at week 23, and livers and kidneys were examined histopathologically. Incidences of hepatocellular adenomas, and those of combined hepatocellular adenomas and carcinomas were significantly elevated in rats given 1,000 mg/kg/day ETBE, but not 100‒500 mg/kg/day ETBE, and there was a significant increase in the average numbers of lesions. No significant differences in incidences and average numbers of renal tubule neoplasms were found in rats administered 100‒1,000 mg/kg/day ETBE. However, the average numbers of atypical tubule hyperplasias, considered to be preneoplastic lesions, were significantly increased in rats given ETBE at 1,000 mg/kg/day, but not in rats given 500 mg/kg/day or lower doses. Thus, these results imply that ETBE has hepatic and renal tumor-promoting activities that affect EHEN-induced carcinogenesis in male rats, and the no-observed-effect level is 500 mg/kg/day under the present experimental conditions.

A survey of solitary deaths in Japan for shortening postmortem interval until discover

Recently in advanced nations, the number of solitary households is increasing. Data from Japanese population survey in 2010 showed that the percent of solitary households was 32.4% and that was the largest category of household types. The Japanese government regards solitary death as important problem, but a useful survey on solitary death has not been performed. We have focused on the postmortem interval until discovery of the death as a measure of solitary deaths. We conducted a survey of 582 forensic autopsy cases in the Osaka medical examiner's office over three years, from April in 2010 till March in 2012. We excluded suicide cases. We collected data on the, gender, age, postmortem interval (PMI) until discovery, family structure, situation of discovery of the body, cause of death, and the time interval from the last hospital visit. Here, we found that people who had high risk of solitary death ranged in, age from 60 to 69 which is the age of retirement for many people. In order to prevent solitary death, we suggest that people who live alone should take better care of themselves and participate in a community setting after their retirement. We can show that the recent efforts of the Japanese government for reducing solitary death had been working well. The government care givers take care of the person living alone almost like their own family. We also suggest that the people who unfortunately do not have any home care should subscribe to a newspaper for shortening the PMI.

Skin Metastasis of Neuroendocrine Carcinoma Derived from the Mediastinum

We report a 46-year-old Japanese man with a metastatic skin tumor on his left palmar region. He underwent resection for a mediastinal neuroendocrine carcinoma in February of 1998. After the operation, he immediately noticed an elevated tumor on his left palm. In September 1999, a brain tumor was discovered. The skin and brain tumors were subsequently removed surgically. Neuron specific enolase (NSE) in the serum was elevated to 25 ng/ml. A skin biopsy specimen from the left palmar site revealed multiple tumor nests which showed the same histological features as the primary mediastinal tumor. Immunostaining was positive for chromogranin, synaptophysin, and NSE but negative for S-100 protein and CD57. To our knowledge, this is the first report of cutaneous metastasis of a neuroendocrine tumor derived from the mediastinum.

Immunohistochemical characteristics of surfactant proteins a, B, C and d in inflammatory and tumorigenic lung lesions of f344 rats

Surfactant proteins (SPs), originally known as human lung surfactants, are essential to respiratory structure and function. There are 4 subtypes, SP-A, SP-B, SP-C and SP-D, with SP-A and SP-D having immunological functions, and SP-B and SP-C having physicochemical properties that reduce the surface tension at biological interfaces. In this experiment, the expressions of SP-A, SP-B, SP-C and SP-D in lung neoplastic lesions induced by N-bis (2-hydroxypropyl) nitrosamine (DHPN) and inflammatory lesions due to quartz instillation were examined and compared immunohistochemically. Formalin fixed paraffin embedded (FFPE) lung samples featuring inflammation were obtained with a rat quartz instillation model, and neoplastic lesions, hyperplasias and adenomas, were obtained with the rat DHPN-induced lung carcinogenesis model. In the rat quartz instillation model, male 10-week old F344 rats were exposed by intratracheal instillation (IT) to quartz at a dose of 2 mg/rat suspended in saline (0.2 ml) on day 0, and sacrificed on day 28. Lung tumorigenesis in F344 male rats was initiated by DHPN in drinking water for 2 weeks, and the animals were then sacrificed in week 30. Lung proliferative lesions, hyperplasias and adenomas, were observed with DHPN, and inflammation was observed with quartz. The expressions of SP-A, SP-B, SP-C and SP-D were examined immunohistochemically. SP-B and SP-C showed strong expression in lung hyperplasias and adenomas, while SP-A and SP-D were observed in mucus or exudates in inflammatory alveoli. These results suggest the possibility that SP-B and SP-C are related to lung tumorigenesis.

No Promoting Effect of Ethyl Tertiary-butyl Ether (ETBE) on Rat Urinary Bladder Carcinogenesis Initiated with N-Butyl-N-(4-hydroxybutyl)nitrosamine

The effects of ethyl tertiary-butyl ether (ETBE) on two-stage urinary bladder carcinogenesis in male F344 rats initiated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) were investigated at various dose levels with regard to possible promoting activity. Groups of 30 rats were given drinking water containing 500 ppm BBN, as an initiator, for 4 weeks and starting one week thereafter received ETBE by gavage (daily, 7 days/week) at dose levels of 0 (control), 100, 300, 500 or 1000 mg/kg/day until experimental week 36. No statistically significant differences in incidences of preneoplastic lesions, papillomas, and carcinomas of the urinary bladder were evident in rats treated with 100–1000 mg/kg/day ETBE as compared with control values. Furthermore, the average numbers of preneoplastic or neoplastic lesions per unit length of basement membrane in rats given 100–1000 mg/kg/day ETBE were also comparable to control values. However, papillomatosis of the urinary bladder was found in 4 out of 30 rats (13%) in the group given 1000 mg/kg/day ETBE, and soft stones in the urinary bladder were found in 3 out of these 4 rats. The results thus demonstrated that ETBE did not exert promotional activity on urinary bladder carcinogenesis. However, papillomatosis of the urinary bladder developed in small numbers of the rats given ETBE at 1000 mg/kg/day but not in rats given 500 mg/kg/day or lower doses.

Evaluation of the quality of life of lupus erythematosus patients with cutaneous lesions in Japan

The quality of life (QOL) of lupus erythematosus (LE) patients with skin manifestations is impaired, but little is known about Japanese patients. We assessed whether the skin symptoms in LE are associated with the QOL using the Japanese versions of the Skindex-29 and Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI). In all, 54 LE patients with cutaneous lesions completed the Japanese version of the Skindex-29, and physicians assessed the severity of their eruptions using the CLASI before and after treatment. The QOL of the LE patients was better after the therapeutic intervention using the Skindex-29 questionnaire. We tested several factors for an independent association with the QOL. A significant risk factor for a poor QOL was a female gender in “Functioning” before treatment. In addition, a poor QOL tended to be correlated with a female gender in “Emotions” and older current age in “Symptoms” before treatment, and with a longer duration of SLE in “Functioning” after treatment. In the CLASI analysis, skin manifestation activity in the acute phase correlated with a poor emotional and functional QOL rather than a symptomatic QOL. To the best of our knowledge, this is the first report evaluating the QOL of Japanese LE patients, despite the small cohort.

Tumor Promotion by 12-O-Tetradecanoylphorbol-13-Acetate in an Ultra-Short-Term Skin Carcinogenesis Bioassay Using rasH2 Mice

Assessment of the skin tumor–promoting potential of 12- O-tetradecanoylphorbol-13-acetate (TPA) after initiation with 7,12-dimethylbenz[ a]anthracene (DMBA) was conducted using rasH2 transgenic (Tg) mice and their nontransgenic (non-Tg) littermates. Mice were treated with DMBA (50 μg/100 μL acetone) on clipped back skin at the commencement of the study, and 1 week thereafter, TPA was applied at 8 μg/200 μL or 4 μg/200 μL acetone, once or twice weekly, for 7 weeks. Skin nodules were observed in the rasH2 Tg mice from week 4, and the incidence reached 100% at weeks 5 and 6. The number of skin nodules (multiplicity) in the 8-μg twice-weekly, 8-μg once-weekly, 4-μg twice-weekly, and 4-μg once-weekly groups was 62.4, 46.2, 62.6, and 36.9, respectively. The non-Tg mice also developed skin nodules, but the sensitivity to induction in the rasH2 Tg mice was higher. No nodules were observed in the acetone groups, but single nodules were apparent in the no-treatment rasH2 Tg and non-Tg groups. In conclusion, skin promotion effects could be detected within only 8 weeks in the rasH2 mice, and the concentration of 4 μg TPA once weekly was sufficient as a positive control. This short-term skin carcinogenesis bioassay using rasH2 mice could represent a useful tool for the assessment of drug and chemical safety with cutaneous treatment.

Abstract 3606: Effect of anatase type nanosized titanium dioxide particles on the rat lung and cultured macrophage

Nanosized titanium dioxide is mainly categorized into anatase type (anatase type nTiO2) and rutile type (rutile type nTiO2), and widely used in industry, commercial products and biosystems. Previous our report indicated that rutile type nTiO2 caused the growth of A549 human lung carcinoma cells, induction of macrophage, an increase of 8-hydroxydeoxyguanosine (8-OHdG) and overexpression of Macrophage inflammatory protein 1α(MIP1α). Furthermore, under ultraviolet irradiation, anatase type nTiO2 is 100 times more toxic than rutile type nTiO2 in vitro. In the present study, we compared the pulmonary toxic effects induced by anatase type nTiO2 and rutile type nTiO2. Female SD rats were treated with anatase type nTiO2 or rutile type nTiO2 by intrapulmonary spraying for 8 times over a two week period. Obvious lung inflammation foci were not observed in the rats treated with anatase type nTiO2 or rutile type nTiO2. Infiltration of alveolar macrophages was observed throughout the lung tissues and anatase type nTiO2 or rutile type nTiO2 particles were exclusively phagocytosed by alveolar macrophages. Treatment with both anatase type nTiO2 and rutile type nTiO2 also increased number of alveolar macrophage and the production of 8-OHdG in the lung tissue, with a littler higher in the rutile type nTiO2 treated group than in the anatase type nTiO2 treated group. Importantly, expression of MIP1α in the lung tissue treated with anatase type nTiO2 and rutile type nTiO2 as either mRNA level and protein level was significantly up-regulated compared with that of the control group, with significantly lower in the anatase type nTiO2 treated group than in the rutile type nTiO2 treated group. Similarly, anatase type nTiO2 induced significantly lower mRNA expression of MIP1α in primary alveolar macrophages (PAM) and protein level of MIP1α in the supernatants of PAM cell culture than rutile type nTiO2. Additionally, supernatants of PAM cell culture treated with anatase type nTiO2 had less effect on the growth of A549 cell than those treated with rutile type nTiO2. Conclusively, treatment with both anatase type nTiO2 and rutile type nTiO2 did not cause notable lung inflammation. Analysis of alveolar macrophage induction, production of 8-OHdG in the lung tissue, and MIP1α expression both in vivo in the lung and in vitro in PAM indicated that anatase type nTiO2 was less effective than rutile type nTiO2, partly due to low photocatalytic effect in the lung tissue.

Citation Format: Takamasa Numano, Jiegou Xu, Mitsuru Futakuchi, Katsumi Fukamachi, Fumio Furukawa, Masumi Suzui, Hiroyuki Tsuda. Effect of anatase type nanosized titanium dioxide particles on the rat lung and cultured macrophage. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3606. doi:10.1158/1538-7445.AM2013-3606

Concordance between Results of Medium-term Liver Carcinogenesis Bioassays and Long-term Findings for Carcinogenic 2-Nitropropane and Non-carcinogenic1-Nitropropane in F344 Rats

This study was conducted to determine the concordance of results for a pair of structural isomers, 2-nitropropane (2-NP) and 1-nitropropane (1-NP), using the rat medium-term liver carcinogenesis bioassay (Ito test) and previously published long-term carcinogenicity tests. Male F344 rats were given a single intraperitoneal injection of DEN (200 mg/kg b.w.) to initiate hepatocarcinogenesis. After 2 weeks, they received per os 0, 0.8, 4 or 20 mg/kg/day of 2-NP or 1-NP six times a week and were subjected to two-thirds partial hepatectomy at week 3. Non-initiated groups receiving 0 or 20 mg/kg/day were also included. The animals were sacrificed for quantitative analysis of GST-P-positive foci at week 8. With the highest dose of 2-NP, significantly increased numbers and areas of GST-P-positive foci were demonstrated as compared with the respective control but were not noted with 1-NP. In the non-DEN-initiated groups, many small GST-P-positive foci of less than 0.2 mm in diameter were also induced in the rats treated with 2-NP at 20 mg/kg/day but were lacking with 1-NP. These results strongly support that 2-NP is a complete hepatocarcinogen with a potent initiation activity, whereas 1-NP is not.

A medium-term, rapid rat bioassay model for the detection of carcinogenic potential of chemicals

The Ito Liver Model and the Ito Multi-organ Model are used in conjunction and constitute an efficient and rapid bioassay for the identification of both genotoxic and nongenotoxic carcinogenic chemicals. The Ito Liver Model is an 8-week bioassay system that uses the number and size of foci of hepatocytes positive for glutathione S-transferase placental form (GST-P) as the end-point marker. One hundred fifty-nine compounds were tested using the Ito Liver Model: 61 of 66 hepatocarcinogens tested positive, and 10 of 43 nonliver carcinogens were also positive. The false-positive detection of noncarcinogens was low; a single false-positive result was obtained from the 50 noncarcinogens tested. Since more than half of all known carcinogens are hepatocarcinogens in rodents, the initial 8-week bioassay is able to detect most carcinogens. The Ito Multi-organ Model is a 28-week bioassay system for the detection of carcinogens that were not identified by the Ito Liver Model. Results are evaluated by preneoplastic and neoplastic lesions in major organs. Forty-four compounds were tested using the Ito Multi-organ Model: 17 out of 17 liver carcinogens were positive, and 19 out of 22 (86%) nonliver carcinogens were positive. None of the five noncarcinogens tested positive.

Male New Zealand Black/KN mice: a novel model for autoimmune-induced permanent alopecia?

BACKGROUND

Irreversible, permanent and scarring alopecia is associated with several autoimmune diseases, including all autoimmune connective tissue disorders. The pathogenesis of autoimmune-induced permanent alopecia (APA) is still poorly understood, and instructive, simple mouse models for the study of APA are needed urgently. During the course of our studies in a well-established mouse model for chronic rheumatoid arthritis, the New Zealand Black/KN (NZB/KN) mouse, we noticed that ageing male NZB/KN mice developed spontaneous APA.

OBJECTIVES

To study whether alopecia seen in ageing male NZB/KN mice displays key features of human APA and may, thus, be a useful new mouse model for clinically relevant APA research.

METHODS

NZB/KN, the F1 hybrid of NZW/N Slc x NZB/KN (W/BKN F1), the F1 hybrid of NZB/KN x NZW/N Slc (BKN/W F1), and the F2 hybrid of W/BKN F1 x W/BKN F1 mice were employed in this study, in order to check which strain carries the highest risk of alopecia development. Besides routine histology, CD3, CD4 and CD8 expression as well as immunoglobulin (Ig) G and IgM deposition in hair follicles were investigated by immunohistology/immunofluorescence. Mast cell distribution/degranulation and Ki-67 (proliferation)/TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling) (apoptosis) positive cells were also analysed.

RESULTS

Only F2 male NZB/KN mice were prone to develop alopecia, suggesting that Y chromosome-associated gene(s) are involved in the pathogenesis of APA, which incidence rises with increasing age. The lesional alopecia skin in 12-month-old male NZB/KN mice showed a sharp decline in hair follicle density, thus meeting a key criterion of permanent alopecia. Both macroscopically and histologically, the alopecia seen in these mice resembled in many respects different stages of clinical APA, such as alopecia associated with chronic discoid lupus erythematosus (DLE) in humans. Lesional APA hair follicles in mice displayed intrafollicular and perifollicular mononuclear cell infiltrates, as well as an increased number of activated (degranulated) perifollicular mast cells. In the fully developed lesion, many CD4+ cells were seen in perifollicular locations, including the epithelial stem cell region (bulge), and also contained a few CD8+ T cells. IgM deposits were found in the follicular basement membrane zone (BMZ). Both in the bulge and the hair matrix region of the affected anagen hair follicles, there were signs of massive keratinocyte apoptosis.

CONCLUSIONS

Our currently available data suggest that male but not female NZB/KN mice may indeed represent a suitable mouse model for APA, with some similarities to the permanent alopecia seen in human DLE patients, although additional and confirmatory investigations are needed before this mouse strain can be accepted as a murine equivalent of APA in humans.

Lack of enhancing effects of sodium nitrite on 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-induced mammary carcinogenesis in female Sprague–Dawley rats

A number of heterocyclic amines (HCAs) have been shown to exert enhanced carcinogenic and mutagenic potential when given simultaneously with sodium nitrite (NaNO(2)). In the present experiment, effects of combined treatment with NaNO(2) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), one of the most prevalent carcinogenic HCAs in the human environment, were assessed with regard to mammary tumor induction in female Sprague-Dawley (SD) rats. Animals at 6 weeks of age were given intragastric doses of 100mg/kg body weight of PhIP twice a week for 4 weeks, during which period 0 or 0.2% NaNO(2) was administered in the drinking water. Control rats received 0.2% NaNO(2) alone for the 4 weeks or non-supplemented water during the entire 48 week experimental period, without carcinogen treatment. The first tumor in the PhIP+NaNO(2) group appeared significantly later than with PhIP alone, and during the experimental period, the incidence, multiplicity and volume of mammary tumors in this group tended towards decreased, although values did not significantly differ at the terminal sacrifice. These results indicate that NaNO(2) does not enhance PhIP-induced rat mammary carcinogenesis, rather possessing some potential for inhibition.

Lack of potential of low dose N-nitrosodimethylamine to induce preneoplastic lesions, glutathione S-transferase placental form-positive foci, in rat liver

Induction of liver lesions in male F344 rats by the genotoxic and carcinogenic N-nitrosodimethylamine (NDMA) was studied at a wide range of dose levels, i.e. from 0.001 to 10 ppm, in drinking water for 16 weeks. Dose related and statistically significant increase of glutathione S-transferase placental form-positive foci, endpoint markers for hepatocarcinogenesis in rats, at 1 and 10 ppm dose groups was obtained, but no increment in foci could be detected with the lower doses (0.001, 0.01, and 0.1 ppm). This finding of a no-observed effect level supports our hypothesis that a threshold, at least in practical terms, exists in carcinogenesis proposed on the basis of extensive wide range dose-dependence studies of other genotoxic carcinogens.

Potent chemopreventive agents against pancreatic cancer

Development of pancreatic cancers is clinically so silent in general that at the time of diagnosis, the vast majority of cases are incurable with a very poor prognosis. Therefore, effective preventive approaches against this aggressive disease are urgently required. Experimentally, carcinogenesis process is assumed to consist of at least two stages named initiation and promotion. Using a two-stage model of hamster pancreatic carcinogenesis, we have reported stage-specific inhibitory effects by a number of potent cancer chemopreventive agents. Among them, phenethyl isothiocyanate (PEITC), a constituent of cruciferous vegetables, remarkably blocked the initiation phase of pancreatic as well as lung carcinogenesis in hamsters initiated with N-nitrosobis(2-oxopropyl)amine (BOP). However, PEITC failed to affect both pancreatic and lung carcinogenesis when given during the post-initiation (promotion) phase of carcinogenesis. In contrast, our recent study clearly demonstrated that a cyclooxygenase (COX)-2 inhibitor substantially protects against BOP-induced pancreatic tumors in hamsters in line with decrease in cell proliferative activity of pancreatic ducts when given in the post-initiation phase. Interestingly, trypsin inhibitors inhibited both initiation and post-initiation phases of BOP-induced pancreatic carcinogenesis although they are known to induce hyperplastic acinar lesions in the rat pancreas. Taken together with these data, our review is aimed at looking over mechanistic insights into potent chemopreventive agents against pancreatic cancer.

Immunohistochemical staining of cutaneous tumours with G-81, a monoclonal antibody to dermcidin

BACKGROUND

Recently, the novel antimicrobial peptide named dermcidin (DCD) was reported in human eccrine sweat glands.

OBJECTIVES

We investigated the expression of DCD in a variety of cutaneous tumours in order to assess the usefulness of the monoclonal antibody (G-81), which recognizes a fragment of DCD.

PATIENTS/METHODS

We studied the immunoreactivity of the G-81 antibody on 197 cutaneous tumours.

RESULTS

A total of 13 of 26 cutaneous mixed tumours showed substantial immunoreactivity. In contrast all the following cases were completely unreactive: (i) epithelial tumours (seborrhoeic keratosis, squamous cell carcinoma, Bowen's disease, actinic keratosis, genital Paget's disease); (ii) follicular tumours (basal cell carcinoma, trichilemmoma, trichoepithelioma, trichoblastoma, keratoacanthoma, proliferating trichilemmal tumour, pilomatricoma); (iii) melanocytic tumours (malignant melanoma, naevus cell naevus, Spitz naevus, blue naevus); (iv) neural tumours (schwannoma, neurofibroma, Merkel cell neoplasm); (v) mesenchymal tumours (soft fibroma, dermatofibroma, dermatofibrosarcoma protuberans, vascular leiomyoma, leiomyosarcoma, lipoma, juvenile xanthogranuloma, angiomyoma); and (vi) other sweat gland tumours (poroid neoplasms, syringoma, cylindroma, clear cell hidradenoma, spiradenoma, syringoid eccrine carcinoma, mucinous carcinoma, apocrine cystadenoma, syringocystadenoma papilliferum, apocrine adenocarcinoma). Twenty-six cutaneous mixed tumours were considered from histopathological findings to be the apocrine type, but 13 of 26 mixed tumours contained some DCD-immunopositive cells that possibly differentiate into eccrine secretory glands.

CONCLUSIONS

We found the expression of DCD in tubular structures of 50% of cutaneous mixed tumours with apocrine differentiation. These results suggest that a number of cutaneous mixed tumours show both eccrine and apocrine differentiation in the same neoplasm.