Avaliação de alterações histopatológicas da próstata e séricas do PSA em ratos tratados com N-Metil-N-Nitrosureia e testosterona / Evaluation of histopathological changes in the prostate and serum PSA in mice treated with N-Methyl-N-Nitrosourea and testosterone

A testosterona tem sido cada vez mais usada em homens na fase do envelhecimento como prevenção e tratamento de doenças metabólicas, melhora do desempenho sexual, proteção cardiovascular e manutenção da cognição. Porém ainda há conflito sobre seus efeitos na próstata com relação às doenças benignas e malignas. O presente estudo avaliou o efeito do tratamento com duas formas de testosterona sobre carcinoma de próstata induzido por N-Metil-N-Nitrosureia (NMU) a partir de análises histopatológicas e séricas do antígeno prostático específico (PSA). Para tal foram utilizados 80 ratos Wistar jovens, sadios, divididos em dois grupos (40 animais cada) tratados ou não com NMU intraperitoneal. Cada grupo foi dividido em quatro subgrupos iguais e tratados durante 16 semanas: 1) tratado com cipionato de testosterona a cada sete dias via intramuscular; 2) tratado com cipionato de testosterona a cada 14 dias via intramuscular; 3) tratado com undecanoato de testosterona oral diariamente; 4) tratado com óleo mineral. Após 16 semanas e tratamento, os níveis do PSA não alteraram em nenhum grupo ou subgrupo e não houve desenvolvimento de tumores em nenhum deles. Portanto, as duas formas distintas de testosterona associada ao uso de NMU em curto espaço de tempo por via intraperitoneal não alteraram as dosagens séricas do PSA e não induziram a formação de tumores na próstata em ratos Wistar jovens e saudáveis. As alterações histopatológicas acinares encontradas nas próstatas foram projeção, secreção, congestão e inflamação, e as epiteliais foram: epitélio normal, redução do epitélio e redução na altura do mesmo. Tais achados colaboram para que outros estudos sejam realizados de maneira a orientar o uso de testosterona na prática clinica diária sem receio de indução do câncer na próstata.

Testosterone has been increasingly used in men during the aging process as prevention and treatment of metabolic diseases, improving sexual performance, cardiovascular protection and maintenance of cognition. But there are still conflicted about its effects in the prostate with respect to benign and malignant diseases. The present study evaluated the effect of treatment with two forms of testosterone on prostate carcinoma induced by N-methyl-N-nitrosourea (NMU) from pathological examinations and serum prostate-specific antigen (PSA). For this we used 80 young Wistar rats, healthy, divides into two groups (40 animals each) or not treated with intraperitoneal NMU. Each group was divided into four equal subgroups and treated for 16 weeks: 1) treated with testosterone cypionate every seven days intramuscularly, 2) treated with testosterone cypionate every 14 days intramuscularly, 3) treated with oral testosterone undecanoate daily, 4) treated with mineral oil. After 16 semanas and treatment, PSA levels did not change in either group or sub-group and no tumor development in any of them. Therefore, two different forms of testosterone associated with the use of NMU in short time intraperitoneally did not affect the serum PSA and did not induce tumor formation in prostate in young healthy rats. Acinar histopathological changes were found in the prostates projection, secretion, congestion and inflammation, epithelial and were normal epithelium, epithelial reduction and reduction in height thereof. These findings collaborate to further studies are performed in order to guide the use of testosterone in daily clinical practice without fear of inducing prostate cancer.

Preclinical and clinical evaluation of intraductally administered agents in early breast cancer.

Most breast cancers originate in the epithelial cells lining the breast ducts. Intraductal administration of cancer therapeutics would lead to high drug exposure to ductal cells and eliminate preinvasive neoplasms while limiting systemic exposure. We performed preclinical studies in N-methyl-N'-nitrosourea-treated rats to compare the effects of 5-fluorouracil, carboplatin, nanoparticle albumin-bound paclitaxel, and methotrexate to the previously reported efficacy of pegylated liposomal doxorubicin (PLD) on treatment of early and established mammary tumors. Protection from tumor growth was observed with all five agents, with extensive epithelial destruction present only in PLD-treated rats. Concurrently, we initiated a clinical trial to establish the feasibility, safety, and maximum tolerated dose of intraductal PLD. In each eligible woman awaiting mastectomy, we visualized one ductal system and administered dextrose or PLD using a dose-escalation schema (2 to 10 mg). Intraductal administration was successful in 15 of 17 women with no serious adverse events. Our preclinical studies suggest that several agents are candidates for intraductal therapy. Our clinical trial supports the feasibility of intraductal administration of agents in the outpatient setting. If successful, administration of agents directly into the ductal system may allow for "breast-sparing mastectomy" in select women.

Intestinal phenotypes of stomach cancers arising after Helicobacter pylori eradication in carcinogen-treated Mongolian gerbils.

AIMS: We have previously demonstrated the importance of gastric and intestinal phenotypic expression for the histogenesis of stomach cancer. However, the phenotypes of stomach cancers arising after Helicobacter pylori (Hp) eradication have hitherto remained unclear. We therefore examined a series of lesions occurring after Hp eradication in the Mongolian gerbil (MG) model. METHODS: Totals of 6 and 20 advanced glandular stomach cancers were evaluated in Hp-eradicated and Hp-infected MGs treated with N-methyl-N-nitrosourea (MNU-MGs), using several gastrointestinal epithelial phenotypic markers. The lesions were divided phenotypically into gastric (G type), gastric-and-intestinal mixed (GI type), intestinal (I type), and null (N type) phenotypes. RESULTS: All 4 differentiated type lesions in Hp-eradicated MNU-MGs were classified as G type, while both of the undifferentiated lesions exhibit the GI type. In Hp-infected MNU-MGs, the lesions were classified as 10 G, 8 GI, and 2 I types, with undifferentiated type lesions having more intestinal phenotypic expression than their differentiated counterparts (P< 0.01). CONCLUSIONS: Our data suggest that the differentiated stomach cancers exhibit the G type in Hp-eradicated MNU-MGs, suggesting that a kind of non-neoplastic G type gland may be precancerous. Intestinalization may still occur, especially in undifferentiated stomach cancers, even if Hp eradication is successful.

Estudo histológico e computadorizado das áreas com células parietais e principais no estômago de ratos Wistar tratados com pantoprazol e N-Nitroso-N-Methylurea (NMU) / Histological and computer study with parietal and chief cells stomach areas in Wistar rats treated with pantoprazole and N-Nitroso-N-Methylurea (NMU)

O uso prolongado dos inibidores da bomba de prótons tem sido considerado uma condição de risco para o desenvolvimento de gastrite atrófica e tumores gástricos. Objetivo: Estudar o efeito do uso de pantoprazol (PTZ) e carcinogênese pela "N-Nitroso-N-Methylurea" (NMU), por 15 semanas, sobre o estômago glandular de ratos Wistar, pela análise histológica e computadorizada das áreas com células parietais (AP), principais (AZ) e da mucosa não oxíntica (ANO), além do estudo das alterações histopatológicas identificadas. Métodos: Quarenta ratos Wistar machos foram distribuídos em 4 grupos: G1 (controle), G2 (NMU+PTZ), G3 (PTZ) e G4 (NMU). O pantoprazol foi administrado 2x/semana (14mg/kg de peso, i.p.) e a NMU oferecida, ad libitum, diluída na água de beber (100mg/ml). Após o estudo histológico AP, AZ e ANO foram determinadas por análise computadorizada das imagens dos estômagos, utilizando o programa "ImageJ 1.19z". Resultados: Mostraram redução da AP e aumento da ANO, em G2, G3 e G4 (p<0,001). Foram encontrados casos de atrofia, inflamação aguda e inflamação crônica, em número que impediu comparação estatística entre os grupos estudados. Conclusão: O uso contínuo de pantoprazol (i.p.), por 15 semanas, reduziu a área com células parietais e aumentou a área de mucosa não oxíntica no estômago glandular de ratos Wistar machos. O mesmo aconteceu no grupo de animais que receberam NMU isoladamente ou em associação com o pantoprazol.

The inhibitory effect of octreotide on experimental colorectal carcinogenesis.

PURPOSE: This study was conducted to investigate the effect of octreotide on colorectal carcinogenesis by administering octreotide either alone or combined with polyglactin, which is a well-known suture material, on chemically induced colorectal cancer development in rats. METHODS: A total of 72 rats were divided into six groups. Two groups were subjected to a colotomy and repair using polyglactin. Another two groups underwent a sham procedure. The fifth group received octreotide alone and the sixth group served as a control. Both groups of rats in the polyglactin and sham groups received octreotide additionally. Methylnitrosourea was administered rectally to all the animals at a dose of 4 mg/kg per week for 20 weeks to induce carcinogenesis. Octreotide was injected twice a day at a total daily dose of 100 microg/kg. The thymidine labeling index was used to assess the synthesis phase fraction in order to measure the cell proliferation rate. RESULTS: The mean number of tumors per rat was significantly higher in the polyglactin group than in both the sham and control groups. It was significantly lower in the octreotide and polyglactin + octreotide groups than in the control and polyglactin groups, respectively. All the animals in the octreotide group had one tumor, while 66.6% of the control group had multiple tumors. The number of multiple tumors was significantly lower in the polyglactin + octreotide and sham + octreotide groups than in the polyglactin and sham groups, respectively. The mean tumor size in the octreotide group was significantly smaller than in the control group, whereas it was larger in the polyglactin group in comparison with the sham and control groups. It was also reduced in the polyglactin + octreotide group in comparison with the polyglactin group. The thymidine labeling index was significantly higher in the polyglactin group compared with both the sham and control groups, whereas it was lower in the octreotide group in comparison with the control group. The addition of octreotide administration to the polyglactin usage and the sham procedure significantly decreased the thymidine labeling indexes. CONCLUSION: These results indicate that octreotide reduces the frequency of tumor occurrence and has an inhibitory effect on its development in chemically induced experimental colorectal cancer. Octreotide can also reduce the enhancing effect of polyglactin on colorectal carcinogenesis when it is combined with polyglactin.

[Aranoza -- a new Russian antineoplastic drug]. / Aranoza--novyi otechestvennyi protivoopukholevyi preparat.

Myelosuppression is a toxicity-related limitation for aranoza dosage. The drug proved effective in the treatment of uterine sarcoma, cancer of the head and neck, breast, Hodgkin's disease and lymphosarcoma during stage II of clinical studies. Complete regression was reported in the treatment of melanoma (ca. 12%). Good results of chemoimmunotherapy should be expected in untreated patients as well as intraarterial infusions for local lesions of the extremities. Clinical trials of aranoza used in combined modalities of therapy in various sites continue.

[Taxotere and methylnitrosourea: experimental appraisal of combination chemotherapy]. / Taksoter i nitrozo metilmochevina: élsperimental'naia otsenka éffektivnosti sovmestnogo primeneniia.

The effectiveness of taxotere and methylnitrosourea (MNU) combined application against murine P388 leukemia has been studied. Antitumor drugs were administered separately or in combination in doses of 50, 60 or 70 mg/kg per day, i/p, beginning from day 1 after tumor transplantation. Combined administration was shown to potentiate antitumor effect, which also largely depended on schedule. Survival increase varied within 50-130% of control values. Optimal effect was observed with the following schedules: taxotere + MNU, 24-hour interval between injections, and MNU-taxotere, 4-day interval between injections. Synergism was in evidence since the therapeutic effect of combination treatment was significantly higher than that of either drug administered alone.

[A comparative study of the action of 1-methyl-1-nitrosourea and 1,3-dimethyl-1-nitrosourea on tumor cell DNA in vitro and in vivo by the alkaline elution method]. / Sravnitel'noe izuchenie deistviia 1-metil-1-nitrozomocheviny i 1,3-dimetil-1-nitrozomocheviny na DNK opukholevykh kletok in vitro i in vivo metodom shchelochnoi éliutsii.

DNA damage of the tumor cells was studied by the method of alkali elution from filters after introduction of 1-methyl-1-nitrosourea (MNU) and 1,3-dimethyl-1-nitrosourea (DMNU) to mice with Ehrlich ascites carcinoma or after treatment of the cultivated cells with these drugs. DNA was essay fluorometrically using DAPI. The degree of DNA damage was characterized by the constant of the alkali elution rate (Kae), which was estimated according to the anamorphism of the kinetic curves of elution. It was shown that in the case of MNU application the tumor cell DNA was damaged to a greater extent than in the case of DMNU application. Kae increased with the concentration of drugs. A correlation was established between the antitumor activity of the drug (kappa), K(ae), and the number of chromosome defects per cell (gaps, deletions, microfragments, ring chromosomes, and translocations). This suggests that kappa is due both to DNA damage and chromosome defects.

[The dose-dependent cytogenetic and growth-inhibiting effects of a new antitumor preparation from the nitrosourea group]. / Dozozavisimyi tsitogeneticheskii i rostingibiruiushchii éffekt novogo protivoopukholevogo preparata gruppy nitrozomochevin.

Kinetics of growth-inhibiting and cytogenetic effect of a new carbon-substituted nitrosourea derivative (ADEKO) has been studied in a wide dose range. A linear dose-effect dependence was observed. The level of damaged cells in a population is connected with a number of chromosomal aberrations per cells with a semilogarithmic dependence. The drug has a pronounced clastogenic effect that reveals itself in total damaging of chromosomal structure of tumor cells. It also causes cell polyploidization with the increase in does and duration of action. Chromosomal aberrations induced by the drug are observed in the tumor long after the action of the drug and their level correlates positively with antitumor activity of ADEKO. ADEKO damages preferentially tumor cells as compared to bone marrow.

[Assessment of individual sensitivity to chemotherapy of human pulmonary tumors transplanted to subrenal capsule of CBA mice]. / Otsenka individual'noi chuvstvitel'nosti k khimiopreparatam opukholei legkogo cheloveka pri ikh transplantatsii pod kapsulu pochki myshei linii CBA.

The individual response to chemotherapy was investigated in 17 heterotransplants of human lung tumours of different histogenesis by the subcapsule test. It is established that the subcapsule test is of high informativity only when testing the individual resistance of lung tumours, especially adenocarcinomas, to cytostatics.

Nitrosourea derivatives for the treatment of Hodgkin's disease involving the central nervous system: a study of 23 cases.

This study deals with the effectiveness of nitrosourea derivatives (nitrosomethylurea and CCNU) used as single agents or in combination with vinca alkaloids, procarbazine and prednisolone in 23 patients suffering from Hodgkin's disease with spinal cord or intracranial involvement. Complete regression of neurologic symptoms was observed in 61% of patients with spinal cord compression and in 4 out of 5 cases of brain involvement. No relationship was found between type, degree and duration of symptoms, and treatment efficacy.

Tumoricidal and immunomodulatory activities of drugs and implications for therapy of mice bearing a late stage MOPC-315 plasmacytoma.

The effectiveness of a relatively low dose of cyclophosphamide (15 mg/kg CY), melphalan (2.5 mg/kg L-PAM) or the monofunctional form of CY (150 mg/kg MoCY) for the cure of mice bearing a large primary s.c. MOPC-315 tumor and extensive metastases has been shown to be dependent on the cooperation of the drugs' tumoricidal activity with T-cell-dependent antitumor immunity, the latter facilitated by the drug's immunomodulatory activity. Here, we have compared the curative effectiveness of three additional drugs: methyl nitrosourea (MNU), hydroxyurea (OH-urea) and bis-chloroethyl nitrosourea (BCNU). Among these drugs, only a relatively low dose of BCNU (15-20 mg/kg) was effective in curing most mice (85%) bearing a large, late stage tumor. A higher dose of BCNU (40 mg/kg, LD10) was much less effective. After an optimal dose of BCNU, the proliferative capacity of the tumor cells 24 h after therapy was reduced by greater than 97%. However, viable tumorigenic cells were still present in the primary tumor and enhanced T-cell-dependent antitumor immunity was necessary for their eradication. The cured mice were resistant to tumor rechallenge. When a low curative dose of L-PAM was followed by OH-urea, the therapeutic effectiveness was not affected, but when this dose of L-PAM was followed by a high nontoxic dose of MNU (100-150 mg/kg), the therapeutic effectiveness was diminished even though MNU was highly tumoricidal (i.e. greater than 99% inhibition of proliferative activity). Thus, BCNU appears to be similar to CY, L-PAM and MoCY in its mechanism of MOPC-315 tumor eradication. The alkylating activity of CY, L-PAM, MoCY and BCNU appears to be critical for their combined tumoricidal and immunomodulatory effects. Since BCNU is the simplest of these four drugs with respect to metabolic pathway, a further study with BCNU and related constructs may shed some light on the biochemical mechanisms of their mode of action. At least one reason for the ineffectiveness of OH-urea or MNU at either low or nontoxic high doses was poor tumoricidal or immunomodulatory activity, respectively. Thus, it seems important to consider both the tumoricidal and immunomodulatory activities of drugs when developing regimens for effective chemotherapy.

[Use of nitrosourea derivatives in the treatment of patients with Hodgkin's disease with lesions of the central nervous system]. / Primenenie proizvodnykh nitrozomocheviny v lechenii bol'nykh limfogranulematozom s porazheniem tsentral'noi nervnoi sistemy.

The study deals with the effectiveness of nitrosourea derivatives (nitrosomethylurea and CCNU) used for monochemotherapy or polychemotherapy in combination with vinca alkaloids, natulan and prednisolone in 22 patients suffering Hodgkin's disease with spinal cord and intracranial involvement. Complete regression of neurologic symptoms was seen in 61.1% of patients with spinal cord dysfunction and in 3 of 4 cases of brain involvement. The effectiveness of nitrosomethylurea-based regimens did not differ-significantly from those including CCNU. The longest complete remission obtained was 124+ months. No relationship was found between the type, degree and duration of symptoms, on the one hand, and the likelihood of achieving complete remission, on the other.

DNA repair synthesis in fibroblast strains from patients with actinic keratosis, squamous cell carcinoma, basal cell carcinoma, or malignant melanoma after treatment with ultraviolet light, N-acetoxy-2-acetyl-aminofluorene, methyl methanesulfonate, and N-methyl-N-nitrosourea.

Fibroblast strains derived from skin biopsies of patients with actinic keratosis (6), malignant melanoma (18), squamous cell carcinoma (11), and basal cell carcinoma (12) were investigated for DNA repair synthesis, with 16 fibroblast strains for normal donors as controls. Cells were exposed to UV light, the "UV-like" carcinogen (Ac)2ONFln, and the methylating carcinogens MeSO2OMe and MeNOUr. Dose-response experiments, which included 10 dose levels, were performed, the data analyzed by linear regression, and the slope of the regression line (term: G0) used as a measure of DNA repair synthesis. The mean experimental variability of G0 of individual fibroblast strains was 9.5%-15.4%, depending upon exposure. For comparison of all cell strains belonging to the same skin malignancy group with those of the control group, G0 values of the individual strains were combined to yield group-specific weighted mean G0 values. In addition, the capacity to incise UV-damaged DNA was measured in 24 cell strains from patients with skin tumors using the alkaline elution technique. For quantitating DNA-incising capacity, the initial velocities of the elution curves were plotted versus the UV dose, and the slope of the resulting regression line was used to obtain the characteristic value E0. The mean experimental variability of E0 of individual strains was +/- 22%. These E0 values were combined to yield weighted mean values of groups. The fibroblast strains in the groups of patients with actinic keratosis and malignant melanoma were found to have normal mean G0 values when DNA repair synthesis was challenged with UV light or one of the three carcinogens. However, the squamous cell carcinoma group exhibited significantly lower mean G0 values after treatment with UV light (82% that of normal donors), (Ac)2ONFln (70%), MeSO2OMe (70%), and MeNOUr (69%). The basal cell carcinoma group showed significantly diminished repair synthesis upon treatment with UV light (81% that of normal donors) and MeSO2OMe (67%). In contrast to these findings, in no skin malignancy group was post UV DNA-incising capacity (E0) significantly diminished, although it should be noted that group sizes were only half as large as for G0 determinations. These data may be interpreted as indicating that DNA excision repair is impaired in fibroblast strains from patients with squamous cell carcinoma and-to a lesser extent-basal cell carcinoma.(ABSTRACT TRUNCATED AT 400 WORDS)

Chemotherapy in intracerebrally transplanted tumors induced with transplacental administration of ethylnitrosourea in rats.

Four tumors of the spinal cord were induced with ethylnitrosourea in rats by transplacental administration and transplanted into the brains of animals of the same strain. One of these intracerebrally grafted tumor lines (G-XIII) was followed up over the first 10 passages and treated with CCNU and other alkylating drugs. The results were compared with findings in an earlier established line (G-XII) in passage 12 and 59, which in the first instance was sensitive to CCNU. The CCNU application prolonged survival in treated animals in various treatment schedules in the first 10 intracerebrally grafted generations of the tumor up to 59%. Induction times of tumors became increasingly shorter. The susceptibility of early passages was similar in both lines. Its loss in late passages went together with diffuse growth of the tumor and reticulin fiber production. In addition, glial fibrillary acid protein expression and formation of intermediate filaments in perivascular tumor cells was lost.