DMBA-induced Breast Cancer In Rats Research Articles

Pro-estrogenic and anti-inflammatory effects of Corchorus olitorius and Amaranthus hybridus leaves in DMBA-induced breast cancer

BackgroundBreast cancer is the world's most prevalent cancer and accounts for the most lost disability-adjusted life years in women worldwide. Tumour-promoting inflammation and sustained proliferative signaling are some hallmarks of cancer which can be activated by environmental carcinogens that induce oxidative stress and inflammation via increased interleukin-6 (IL-6) secretion. Increased binding of estrogen promotes the development and proliferation of breast cancer. Phytochemicals have been reported to promote health by combating oxidative stress. PurposeThis study aims to assess the potential of crude hydroethanolic extract of C. olitorius (CO) and A. hybridus (AH) singly and in combination on IL-6 and estrogen in DMBA-induced breast cancer in rats. Study designA 9 × 6 animal model made up of three groups each of control (normal, negative, positive), chemopreventive, and therapeutic (CO, AH, CO + AH mix). MethodsPhytochemical analyses were carried out on the plants, and breast cancer (BCa) was induced in female Sprague-Dawley rats by administering 80 mg/Kg BW DMBA single dose orally. ELISA kits were used to determine the levels of IL-6 and estradiol in plasma. ResultsThe group administered Tamoxifen and a combination of both plants recorded significantly higher plasma levels of estradiol (p = 0.0005 and p = 0.0242) respectively. Chemopreventive AH and CO + AH mix (39.46 ± 3.167; 39.69 ± 1.837) respectively had IL-6 levels similar to the normal control (38.03 ± 2.334) and less than in the corresponding therapeutic groups (60.75 ± 13.08;57.88 ± 15.32) suggesting synergistic effect of both plants. ConclusionA. hybridus can better prevent inflammation. We propose that the plants possess pro-estrogenic and anti-inflammatory potentials.

Breast cancer cell growth arrest and chemopreventive effects of Passiflora edulis Sims (Passifloraceae) ethanolic leaves extract on a rat model of mammary carcinoma.

Despite various prevention and treatment measures, the incidence and mortality due to breast cancer has been increasing globally. Passiflora edulis Sims is a plant used for the treatment of various diseases in traditional medicine, including cancers. To assess the anti-breast cancer activity of the ethanolic extract of P. edulis leaves in vitro and in vivo. In vitro, the cell growth and proliferation were determined based on the MTT and BrdU assays. The flow cytometry was used to analyze the cell death mechanism while, cell migration, cell adhesion and chemotaxis were assayed for anti-metastatic potential. In vivo, 56 female Wistar rats aged 45-50 days (∼75g) were exposed to 7,12-dimethylbenz(a)anthracene-DMBA except the normal group. Negative control group (DMBA) received solvent dilution throughout the study; standards groups (tamoxifen - 3.3mg/kg BW and letrozole - 1mg/kg BW) as well as P. edulis leaves ethanolic extract groups (50, 100 and 200mg/kg) treated for 20 weeks. Tumor incidence, tumor burden and volume, CA 15-3 serum' level, antioxidant, inflammatory status and histopathology were assessed. P. edulis extract showed a significant and concentration-dependent inhibition of MCF-7 and MDA-MB 231cells growth at 100μg/mL. It inhibited cell proliferation and clones' formation and induced apoptosis in MDA-MB 231cells. The migration of cell into the zone freed of cells and the number of invading cells after the 48 and 72h were significantly diminished while, it increased their adherence to collagen and fibronectin extracellular matrix as does Doxorubicin. In vivo, all rats in the DMBA group exhibited a significant (p < 0.001) increase in tumor volume, tumor burden and grade (adenocarcinoma of SBR III) and pro-inflammatory cytokine levels (TNF-α, INF-γ, IL-6 and IL-12). P. edulis extract at all tested doses significantly inhibited the DMBA-induced increase in tumor incidence, tumor burden and grade (SBR I) as well as pro-inflammatory cytokines. Moreover, it increased enzymatic and non-enzymatic antioxidants (SOD, catalase, and GSH) and decreased MDA levels although a greater effect was observed with Tamoxifen and Letrozole. P. edulis has medium content on polyphenols, flavonoids and tannins. P. edulis has chemo-preventive effects against DMBA-induced breast cancer in rats probably through its antioxidative, anti-inflammatory and apoptosis-inducing potentials.

Seguridad y efecto protector de Cenchrus echinatus en el cáncer de mama inducido en ratas

Introduction: Breast cancer is a disease that is increasing its incidence annually, so in search of complementary alternatives for treatment have been studied some medicinal plants containing large amounts of polyphenols, which have anticancer effects as is the case of Cenchrus echinatus L. Objective: To determine the safety and protective effect of ethanol extract of Cenchrus echinatus L. (burdock) on breast cancer induced by 7,12-dimethylbenz[a]anthracene in rats. Methods: Preclinical, experimental study in male Balb/C53 mice and Holtzman rats of both sexes. Acute toxicity and toxicity at 45 days were calculated using probit and OECD methods, respectively; to evaluate the protective effect, the Barros 2004 method was used; tumor cell proliferation was also registered microscopically, using descriptive and inferential statistical analysis, considering p&lt;0.05. Results: Safety studies show that the extract does not induce significant hematologic, biochemical and pathological changes level 80% of the protective effect of the extract against DMBA-induced breast cancer in rats was achieved. Conclusions: It has been shown that Cenchrus echinatus extract L. has protective effect on breast cancer by 7,12-dimethylbenz[a]anthracene induced in rats; and it is not toxic in mice and rats.

In vivo, in vitro and in silico anticancer investigation of fullerene C60 on DMBA induced breast cancer in rats

AimsThe aim of the study was to determine the protective and therapeutic effect of fullerene C60 nanoparticle on DMBA-induced breast cancer in rats. Main methodsIn vitro cell viability was determined by the WST-1 test. In vivo analysis was performed in female Wistar Albino rats. The expression of caspase-3, Bcl-2, Nrf-2, NF-κB, TNF-α, COX-2, p53, IL-6, IL-1α ve p38α (MAPK) proteins were assessed by western blotting. Furthermore, malondialdehyde (MDA), glutathione (GSH), catalase activity (CAT), total protein levels and DNA damage were investigated. In addition, tissues were evaluated by histopathologically. In in silico analysis, the binding affinities of the fullerene C60 nanoparticle to transcription factors such as caspase-3, Bcl-2, Nrf-2, NF-κB, TNF-α, COX-2, VEGF and Akt were demonstrated by molecular docking. Key findingsTreatment of MCF-7 cells at various concentrations of fullerene C60 (0.1 to 100 mg/ml) inhibited cell viability in a dose dependent manner. Fullerene C60 treated rats exhibited considerable increase in the level of caspase-3 while decrease in the level of pro-survival protein Bcl-2. Bcl-2, NF-κB, TNF-α, COX-2, IL-6, IL-1α and p38α (MAPK) protein expression levels and malondialdehyde (MDA) levels were decreased in the C60 + DMBA groups compared to the DMBA group. It was observed that caspase-3, Nrf-2 and p53 protein expression levels, glutathione (GSH) level, catalase activities (CAT) and total protein levels increased significantly which was further confirmed through the resulting DNA fragmentation. SignificanceIn silico assays, fullerene C60 has been observed to have similar affinity to some crystal ligands, especially against cancer.

In vivo Evaluation of Nanostructured Lipid Carrier System in Rats Bearing Breast Tumor

The aim of this work is to study the anti-proliferative potential of two anticancer drugs loaded in nanostructured lipid carriers (NLCs).The maximal inhibition of cell growth by Raloxifene (RLX) &amp; Curcumin (CUM) nanostructured lipid carriers (RLX-CUM-NLCs) was determined by assessing the viability of MDA-MB 231 cells. As far as we know, this is the first research to look at the effects of RLX-CUM-NLCs on DMBA-induced breast carcinogenesis in a rat model. RLX-CUM-NLCs reduced the number of tumors in an in-vivo investigation. After 14 weeks of induction, we discovered a tumor with a 100% incidence rate. The incidence of experimental breast cancer was decreased to 83.33% in the RLX-treated group. In contrast, RLX-CUM-NLCs demonstrated a significant anticancer effect with a 50% incidence in the RLX-CUM-NLCs group. Compared to controls, the RLX-CUM-NLCs therapy did not cause any toxicity in the animals in terms of food intake, body weight, or activity levels until 300 mg/kg BW. The current research shows that the RLX-CUM-NLCs has a chemopreventive impact on DMBA-induced breast cancer in rats by decreasing tumor burden and restoring marker enzymes activity.

The combined effect of pomegranate extract and tangeretin on the DMBA-induced breast cancer model

The aim of this study was to investigate the protective effects of pomegranate extract and tangeretin alone or in combination in DMBA-induced rat breast cancer model.A total of 68 female rats were randomly divided into 8 groups. The first 4 groups were designed as controls for cancer and treatment groups, and the control groups were composed of only control (C), Pomegranate (P), Tangeretin (T), and Pomegranate+Tangeretin (P+T) groups. The other four groups were designed as cancer and treatment groups and were composed of DMBA (D) and DMBA+Pomegranate (D+P), DMBA+Tangeretin (D+T), DMBA+Pomegranate+Tangeretin (D+P+T) groups. Tumor markers and angiogenesis parameters were studied from plasma samples obtained from rats. Histopathological, immunohistochemical, and TUNEL analyses and expressions of proteins affecting apoptosis and cell cycle were determined in breast tissue samples.In the DMBA group, plasma CA15-3, CEA, VEGF, MMP-9, and NF-κB levels were significantly increased compared to the controls, but significant decreases were observed in these parameters except MMP-9 in the treatment groups. It was observed that p53 and Bax expressions significantly increased in both D+P and D+P+T groups compared to the DMBA group, and these findings were supported by Tunel and immunohistochemical findings. Cyclin D1 expressions were found to be significantly decreased only in the D+T group and supported by TUNEL and immunohistochemical findings. Immunohistochemical ER-α and Ki-67 immune reactivities were significantly decreased in all treatment groups compared to the DMBA group.Our results showed that combined application of pomegranate extract and tangeretin may be more beneficial in preventing breast cancer development.

The Effect of Zinc and Melatonin Administration on Lipid Peroxidation, IL-6 Levels, and Element Metabolism in DMBA-Induced Breast Cancer in Rats

The purpose of this study was to investigate the effects of zinc and melatonin administration on interleukin-6, lipid peroxidation parameters, and element metabolism in DMBA-induced breast cancer in female rats. A total of 42 recently weaned Wistar rats were divided into 5 groups as follows: control (group 1), DMBA control (group 2), DMBA + zinc (group 3), DMBA + melatonin (group 4), and DMBA + melatonin and zinc (group 5). Malondialdehyde (MDA) and glutathione (GSH) levels in breast tissue and blood samples were determined via spectrophotometric methods. In addition, iron, magnesium, zinc, and copper levels in serum samples were determined by atomic emission, and plasma interleukin-6 levels were determined by ELISA method. The highest tissue and plasma MDA and the lowest tissue and erythrocyte GSH levels found in the study were in group 2; the highest tissue and erythrocyte GSH levels and the lowest tissue and plasma MDA levels are in group 5 (P < 0.05). Iron, magnesium, and zinc levels of groups 3, 4, and 5 were higher than the DMBA group without administration (group 2), but the copper values were significantly lower (P < 0.05). The highest IL-6 levels were determined in group 2 while IL-6 levels in the DMBA group (G5) treated with combined melatonin and zinc were lower than all other breast cancer groups (P < 0.05). According to the findings obtained in this presented study, combined zinc and melatonin therapy can contribute to the prevention of tumor growth by improving the disruption in element metabolism and suppressing IL-6 levels and reducing tissue damage that causes the cancer.

Zinc and melatonin supplementation ameliorates brain cortex tissue damage in DMBA-induced breast cancer in rats.

This study aims to investigate the effects of zinc and melatonin supplementation on lipid peroxidation in the brain cortex in DMBA-induced breast cancer in female rats. A total of 42 recently weaned Wistar rats were divided into 5 groups as follows: Control (Group 1), DMBA Control (Group 2), DMBA+Zinc (Group 3), DMBA+Melatonin (Group 4), DMBA+Melatonin et Zinc (Group 5). At the end of the study, all animals were sacrificed by decapitation and Malondialdehyde (MDA) and glutathione (GSH) levels in brain cortex tissue samples were determined via spectrophotometric methods. The highest MDA levels were in the DMBA-treated group (Group 2) (p<0.05). MDA levels in Group 3, Group 4, and Group 5 were significantly lower than in group 2 (p<0.05). Also, GSH levels in group 3, 4, and 5 were significantly higher than in group 2 (p<0.05). There are no reports on whether DMBA-induced experimental breast cancer affects oxidative stress in brain tissue. In this respect, our study revealed that the increased brain cortex tissue damage in DMBA-induced breast cancer is alleviated by Zinc, melatonin, or combined zinc and melatonin treatment (Fig. 3, Ref. 26).

Antitumour Property of Pterocarpus santalinus Seeds Against DMBA-Induced Breast Cancer in Rats.

Breast cancer has been one of the most common form of malignancy globally among women, for more than a decade. Despite various preventive and treatment measures, it remains associated with high incidence and mortality rate. Pterocarpus santalinus Linn. f. has been extensively used in Indian medicine system Ayurveda, due to its various medicinal properties. However, despite various research works on the anticancer activity of P santalinus, no studies have been reported on animal model. Therefore, this study was aimed to decipher the antitumour activity of ethanolic seeds extract of P santalinus on DMBA (7,12-dimethylbenz(a)-anthracene)-induced breast cancer in rats. Fifty-five-days-old weighed (150 ± 10 g) female Charles Foster rats (12 females) were used for the study. The rats were divided into 3 groups of 4 rats each. 7,12-Dimethylbenz(a)-anthracene (single dose of 20 mg/mL dissolved in olive oil) was induced orally, to develop breast tumour. After the development of breast tumours (about 0.5 cm), the rats were treated with P santalinus ethanolic seeds extract (300 mg/kg body weight/day) orally for 5 weeks and then volume of tumour was measured. Oral administration of P santalinus extract resulted in about 49.5% tumour growth inhibition in the final week of treatment in DMBA + P santalinus group as compared with the DMBA group. Pterocarpus santalinus administration also significantly reduced (P < .0001) the serum malondialdehyde level from 58.81 ± 4.09 nmol/mL in DMBA group to 10.87 ± 1.20 nmol/mL in the DMBA + P santalinus group. Serum tumour necrosis factor-α level reduced significantly (P < .0001) from 80.43 ± 2.45 pg/mL in DMBA group to 28.30 ± 3.24 pg/mL in the DMBA + P santalinus group. The blood serum glucose level also reduced significantly (P < .0001) from 205.9 ± 22.22 mg/dL in DMBA group to 86.44 ± 8.36 in DMBA + P santalinus group. There was significant (P < .0001) improvement in the both the liver and kidney serum biomarkers level after P santalinus administration. The histological study of mammary tissues of rats shows that, in the DMBA group immature fibrocytes are completely replacing the normal adipocytes suggestive of fibroma molle, whereas in the DMBA + P santalinus group mature fibrocytes with multilayer glandular cells were seen denoting fibroadenoma. Thus, the P santalinus ethanolic seed extract possesses antitumorigenic, antioxidant and hypoglycaemic properties as well as hepato-renal protective effect. Hence, it may be concluded that P santalinus has therapeutic role against DMBA-induced breast cancer in rats and has a greater potential to develop as a chemotherapeutic agent in breast cancer treatment.

Modulatory Effects of Concanavalin A and D 609 on Apoptotic Markers in Dimethylbenz (a) anthracene induced Breast Cancer in Rats

The present study was conducted to evaluate the chemopreventive efficacy and modulatory effects of concanavalin A and D609; either individually or in combination, on some apoptotic markers in Dimethylbenz (a) anthracene (DBMA) induced breast cancer in rats. Breast cancer was induced in adult female albino rats by injection of DMBA (50 mg/kg b. wt.). After 15 weeks, animals and divided into four groups. One group did not receive any treatment and served as a tumor group. The other three groups were injected with concanavalin A (of 20 mg/kg b. wt.) or D609 (50 mg / kg b. wt.) or both components together for a period of 8 weeks. At the end of experimental period, animals of control and treated groups were sacrificed and samples of breast tissues were obtained and prepared for analysis of the apoptotic markers Bcl-2 (B -cell leukemia/ lymphoma 2), Bim (BcL2 interacting mediator), Bax (Bcl-2 associated X protein), Caspase 9, and Caspase 3. The results exhibited highly significant changes in apoptotic markers in cancer group as compared to normal control group, mainly represented by the increased levels of Bcl-2 and decreased levels of Bim, Bax and caspases 3 and 9. On the other hand, concanavalin A and D609 treatments induced significant modulatory effects on these markers. They induced significant decrease in Bcl-2 levels and increase in Bim, Bax and caspases 3 and 9 levels in all treated groups as compared to the DBMA-tumor group. These ameliorative changes were highly significant in the group of animals exposed to co-treatment of both materials. To conclude: the present study provides evidence that concanavalin A and D609 enhance apoptotic activity in DMBA-induced breast cancer in rats and suggests that the use of combination of the two therapies is recommended in the treatment of breast cancer.

Is there any potential anticancer effect of raloxifene and fluoxetine on DMBA-induced rat breast cancer?

Breast cancer is the most common cancer among women in the world and the incidence is increasing alarmingly. It was aimed to determine the effect of raloxifene (RAL) and fluoxetine (FLX) on selected parameters in 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinoma. Thirty-two female Wistar albino rats were assorted into four groups: DMBA (group I), DMBA+RAL (group II), DMBA+FLX (group III), and DMBA+RAL+FLX (group IV). Mammary tissue vascular endothelial growth factor (VEGF), macrophage colony-stimulating factor (M-CSF), matrix metalloproteinase-9 (MMP-9), and tissue inhibitors of matrix metalloproteinase-1 (TIMP-1) levels were determined by the enzyme-linked immunosorbent assay method. The tissue VEGF levels were lower in group IV compared with DMBA group. Decreased M-CSF levels were observed in all therapeutic groups rather than the DMBA group, but the most effective decrease was found in group IV. Compared with the DMBA group, MMP-9 levels were statistically significantly decreased in group II and group IV. However, TIMP-1 levels were higher in the whole therapeutic groups rather than the DMBA group and the most effective increase was observed in group IV. Results of the present study suggest that combined therapy of RAL with FLX might lead to a better outcome targeting breast tumor.

Ameliorative potential of fluoxetine/raloxifene combination on experimentally induced breast cancer.

Breast cancer is one of the most common types of malignancies in females worldwide. Targeting the estrogen receptors alone with raloxifene (RAL) reduces the incidence of estrogen receptor positive tumors. Fluoxetine (FLX) is one of selective serotonin reuptake inhibitors that was proven to have anticancer properties. Our aim was to detect the effects of RAL/FLX combination on experimentally induced breast cancer. Eighty female Wistar rats were divided into four equal groups: 7,12-Dimethyl Benzanthracene (DMBA) induced breast cancer group, DMBA+RAL, DMBA+FLX and DMBA+RAL+FLX. Tumor volume, tissue malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6) and transforming growth factor beta1 (TGF-β1) were determined in the tumor tissues. Parts of the tumor were subjected to histopathological examination. RAL or FLX alone or in combination induced significant increase in tumor CAT and SOD with significant decrease in tumor volume, tissue MDA, TNF-α, IL-6 and TGF-β1 and alleviated the histopathological and immunohistochemical changes compared to DMBA group. In conclusion, RAL/FLX combination had a better effect than each of RAL or FLX alone against DMBA-induced breast cancer in rats which may represent a new therapeutic modality for management of breast cancer.

Protective Effect of Piper aduncum Capsule on DMBA-induced Breast Cancer in Rats.

The possible protective effect of Piper aduncum capsule on DMBA (dimethylbenz[α]anthracene)-induced breast cancer in rats was assessed by monitoring the tumor and lung metastases incidence and recording hematological and biochemical parameters and frequency of micronuclei. Mammary carcinogenesis was induced in 36 female Holtzman rats by providing a single subcutaneous injection of DMBA. Oral administration of P. aduncum capsule lowered adenocarcinoma and lymph node metastases incidence. Pulmonary metastasis was significantly lowered (P < 0.05). Hematological indicators showed that the triglyceride level was significantly lowered (P < 0.01) and high-density lipoprotein (HDL) level was significantly increased (P < 0.01). Also, P. aduncum capsule significantly lowered the C reactive protein (CRP) level (P < 0.01) and malondialdehyde level (P < 0.05). There was a significant decrease in the frequency of DMBA-induced micronucleated polychromatic erythrocyte (P < 0.01). Considering the antitumorigenic, hypolipidemic, anti-inflammatory, antioxidant, and antigenotoxic properties of P. aduncum capsule, we conclude that it has a protective effect on DMBA-induced breast cancer in rats.

울금이 MDA-MB-231 세포 및 DMBA로 유발된 흰쥐의 유방암에 미치는 영향

Objectives: Breast cancer is the most common cancer among women and has rapidly increasing rate annually. At present, western cancer therapies by surgery, radiation, and anticancer drug have not been fully effective. So many interests are given to herbal medicine on cancer treatment recently. This study was designed to investigate the effects of Curcuma longa L. (CL) on MDA-MB-231 human breast cancer cells and DMBA-induced breast cancer in rats. Methods: In this experiment, MDA-MB-231 cells were cultured in cell culture plates. 0.0625, 0.125, 0.25, 0.5, 1.0 mg/ml of CL extract were tested for their anti-proliferative effects on MDA-MB-231 cells by MMT assay. And we induced breast cancer in rats. The changes in tumor's weight, and the effects on proliferations of splenocyte and thymocyte were investigated. Results: CL showed anti-proliferative effects on MDA-MB-231 cells in proportion to concentration of the CL. DMBA-induced breast cancer in rats, tumor's weight of the rat was not statistically significant, but showed a tendency to be reduced in the groups treated with CL. Proliferation rate of the rat's splenocyte and thymocyte increased in proportion to CL. In breast cancer tissue, expression of ER-<TEX>${\alpha}$</TEX> was weakened proportionately to the concentration of the CL. Conclusions: These data suggest that CL can prevent the proliferation of breast cancer, then CL is useful to treat patient with breast cancer.

Oral administration of loquat suppresses DMBA-induced breast cancer in rats

This study was to demonstrate whether loquat leaves protect against 7,12-dimethylbenz[α]anthracene (DMBA)-induced breast cancer in female rats. Rats were fed control diet (NC, DC), ethanol (DE), or water extract of loquat leaves (DW) until sacrifice. At 50 days of age, animals in the DC, DE, and DW groups were given a single intra-gastric dose of DMBA (50 mg/kg) dissolved in corn oil. Both the water and ethanol extracts of loquat leaves decreased the incidence of tumors, with water extract having the higher inhibitory effect. Ethanol extract significantly decreased the multiplicity of tumors. Loquat extracts significantly decreased tumor cell proliferation and the tumor grade based on the degree of tubule formation. These results suggest that both water and ethanol extracts of loquat leaves inhibit the development of breast cancer. Such inhibition may be based on the suppression of initiation and tumor cell proliferation.

Three-Dimensional (3D) Imaging of Tumor Angiogenesis and its Inhibition: Evaluation of Tumor Vascular-Targeting Agent Efficacy in the DMBA-induced Rat Breast Cancer Model by Confocal Laser Scanning Microscopy (CLSM)

There is considerable interest in tumor angiogenesis and its inhibition, because tumor angiogenesis plays an important role in tumor growth and distant metastasis, and is highly associated with overall survival and relapse free-survival in cancer patients. This study was performed to determine the mechanisms underlying tumor angiogenesis and its inhibition using the angiogenesis inhibitor TNP 470 and antimitotic drug, docetaxel (Taxotere). Variable 3D image analysis of tumor vasculature after chemotherapy was performed by CLSM using the DMBA-induced rat breast cancer model. 3D images of the vasculature in DMBA-induced rat breast cancer were characterized by increased microvessel density and anastomosing, irregularly branched microvessel networks. After administration of TNP-470 or docetaxel, tumor microvessel density was markedly decreased and tumor microvessel networks were markedly destroyed. Furthermore, tumor microvessels less than 30 μm in diameter were not found. The remaining tumor microvessels (30-60 μm in diameter) were mainly localized in the periphery of the tumor. These observations suggest that docetaxel might have the ability to inhibit tumor angiogenesis as well as TNP-470. CLSM with the FI method is a valuable technique for estimation of the efficacy of anti-angiogenic chemotherapy.

Dynamic MR imaging and tumor angiogenesis in DMBA-induced rat breast cancer: Three dimensional (3D) reconstructed image analysis of tumor microvessels by confocal laser scanning microscopy

We investigated the correlation between dynamic magnetic resonance imaging (MRI) findings in breast cancer and tumor angiogenesis in a dimethylbenz(a)anthracene(DMBA)-induced rat breast cancer model. In this study, we clearly demonstrated the three-dimensional (3D) architecture of tumor microvessel networks(MN)by confocal laser scanning microscopy (CLSM)and also investigated the hyperpermeability of tumor microvessels. Dynamic MRI findings were closely related to tumor angiogenesis. Three-dimensional reconstructed image analysis by CLSM revealed that the depicted images were dependent on microvessel density as well as microvessel permeability. It should be emphasized that dynamic MRI may have the potential to evaluate the tumor angiogenic activity in human breast carcinoma.

Statistical errors invalidate conclusions in "Caffeine and unsaturated fat diet significantly promotes DMBA-induced breast cancer in rats".

The conclusion drawn in a recent paper by Minton and associates (Cancer 1983; 51:1249-1253), that caffeine and an unsaturated fat diet significantly promoted dimethylbenz(a)anthracene (DMBA)-induced breast cancer in rats, is based on fallacious statistical reasoning. Minton and associates based their conclusion on the mean latency to first tumor appearance for rats diagnosed with tumors. However, evaluation of percentages of tumor-bearing rats yields contrary results. Using data from a totally negative hypothetical two-group experiment, we demonstrate how such "conflicting" results could arise from differential intercurrent mortality in the two groups. The correct statistical analysis of this hypothetical experiment allows for differential intercurrent mortality and no conflict arises; the data of Minton and associates need to be analyzed by these methods.

Caffeine and unsaturated fat diet significantly promotes DMBA-induced breast cancer in rats.

The following study was carried out to determine the possibility of caffeine being a promoter of breast cancer development in animals consuming vegetable fat. A controlled study, comparing the time of mammary tumor development and the number of tumors was carried out in Sprague-Dawley rats which had been given 20 mg of DMBA at seven weeks of age. This study evaluated the tumor promotional effects of caffeine alone, caffeine and unsaturated fat in combination, unsaturated fat alone, and a standard rat chow diet. The results show that the rats which consumed caffeine and unsaturated fat had the earliest development of tumor and the most multiple tumor occurrence. Average time to tumor development was 95 days. The fat or standard chow rats had an average time to tumor development of 134 and 140 days, respectively. The caffeine-alone rats had a mean time to tumor development of 188 days. The combination of an unsaturated fat diet and caffeine significantly shortened the time to tumor development when compared with the other three groups.

乳癌とGonadal Hormoneの関連性に関する研究

Gonadotropin was assessed using radioimmunoassay on the rat sera of DMBA-induced breast cancer and tissue obtained from DMBA-induced rat breast cancer.In the above materials, there were no significant differences in the amount observed between control group and nontreated groups, ovariectomized and adrenalectomized animals. After removal of the both ovaries and adrenal glands, the rats were given estradiol followed by lutenizing hormone-releasing hormone. In these treated animals' sera, the level of lutenizing hormone was elevated markedly. Concerning the organ uptake of 125I-lutenizing and follicle stimulating hormones after their intraperitoneal injections, one found the highest distribution of these hormones in the kidney and liver and in lesser degree, in the DMBA-induced rat breast cancer tissue and ovary.