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The American Journal of Pathology Mar 2021Nerve infiltration into the tumor is a common feature of the tumor microenvironment. The mechanisms of axonogenesis in breast cancer remain unclear. We hypothesized that...
Nerve infiltration into the tumor is a common feature of the tumor microenvironment. The mechanisms of axonogenesis in breast cancer remain unclear. We hypothesized that vascular endothelial growth factor (VEGF), as well as nerve growth factor (NGF), is involved in the axonogenesis of breast cancer. A N-methyl-N-nitrosourea (MNU)-induced rat model of breast cancer was used to explore the presence of axonogenesis in breast tumor and the involvement of VEGF, as well as NGF, in the axonogenesis of breast tumor. Nerve infiltration into the tumor was found in MNU-induced rat model of breast cancer including the sensory and sympathetic nerve fibers. Nerve density was increased following the growth of tumor. The sensory neurons innervating the thoracic and abdominal mammary tumors peaked at T5 to T6 and L1 to L2 dorsal root ganglions, respectively. Either VEGF receptor inhibitor or antibody against VEGF receptor 2, as well as NGF receptor inhibitor, apparently decreased both the nerve density and vascular density of breast tumor. The reduced nerve density was correlated with the decreased vascular density induced by these treatments. In cultured dorsal root ganglion neurons, phosphatidylinositol 3 (PI3K)/Akt, extracellular signal-regulated protein kinase (ERK), and p38 inhibitors significantly attenuated VEGF-induced neurite elongation. These findings provide direct evidence that VEGF, as well as NGF, may control the axonogenesis of breast cancer.
Topics: Alkylating Agents; Animals; Axons; Extracellular Signal-Regulated MAP Kinases; Female; MAP Kinase Signaling System; Mammary Neoplasms, Experimental; Methylnitrosourea; Neurites; Neurogenesis; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Signal Transduction; Vascular Endothelial Growth Factor A
PubMed: 33345997
DOI: 10.1016/j.ajpath.2020.12.006 -
International Journal of... 2022Angiogenesis is the process of new vascular formation, which is derived from various factors. For suppressing cancer cell growth, targeting angiogenesis is one of the...
Angiogenesis is the process of new vascular formation, which is derived from various factors. For suppressing cancer cell growth, targeting angiogenesis is one of the therapeutic approaches. Vascular endothelial growth factor family receptors, including Flt-1, Flk-1 and Flt-4, have been found to play an essential role in regulating angiogenesis. Rapamycin is a macrolide compound with anti-proliferative properties, while platelet factor-4 (PF-4) is an antiangiogenic ELR-negative chemokine. Rapamycin inhibits mTOR ligands activation, thus suppressing cell proliferation, while PF-4 inhibits cell proliferation through several mechanisms. In the present study, we evaluated the effects of rapamycin and platelet factor-4 toward breast carcinoma at the proteomic and genomic levels. A total of 60 N-Methyl-N-Nitrosourea-induced rat breast carcinomas were treated with rapamycin, platelet factor-4 and rapamycin+platelet factor-4. The tumours were subsequently subjected to immunohistochemical protein analysis and polymerase chain reaction gene analysis. Protein analysis was performed using a semiquantitative scoring method, while the mRNA expression levels were analysed based on the relative expression ratio. There was a significant difference in the protein and mRNA expression levels for the selected markers. In the rapamycin+platelet factor-4-treated group, the Flt-4 marker was downregulated, whereas there were no differences in the expression levels of other markers, such as Flt-1 and Flk-1. On the other hand, platelet factor-4 did not exhibit a superior angiogenic inhibiting ability in this study. Rapamycin is a potent antiangiogenic drug; however, platelet factor-4 proved to be a less effective drug of anti-angiogenesis on rat breast carcinoma model.
Topics: Angiogenesis Inhibitors; Animals; Female; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Methylnitrosourea; Platelet Factor 4; Rats, Sprague-Dawley; Receptors, Vascular Endothelial Growth Factor; Sirolimus; Rats
PubMed: 35037503
DOI: 10.1177/20587384211059673 -
Molecular Biology Reports Sep 2022In this study, two main research objectives were examined: (1) the cytotoxic and anticancer activities of the aqueous methanol extract from Acacia nilotica flowers on...
PURPOSE
In this study, two main research objectives were examined: (1) the cytotoxic and anticancer activities of the aqueous methanol extract from Acacia nilotica flowers on three human cancer cells, namely lung A549, breast MCF-7, and leukemia THP-1 cells, and (2) the genotoxic effects of A. nilotica extract and its influence on DNA damage induced by N-methyl-N-nitrosourea (MNU) in mice.
METHODS
Mice were orally treated with A. nilotica extract (200, 500, and 800 mg/kg for 4 days) with or without MNU (80 mg/kg intraperitoneally for 24 h).
RESULTS
In vitro experiments showed that A549 cells were the most sensitive to A. nilotica extract among the tested cell lines. A. nilotica extract inhibited A549 cell proliferation by blocking the cell cycle at the G/M phase and accumulating apoptotic cells in the sub-G/G phase in A549 cells. In vivo experiments showed that MNU induced positive and negative genotoxicity in bone marrow cells and spermatocytes, respectively. Negative genotoxicity was observed in A. nilotica extract-treated groups only. However, A. nilotica extract (800 mg/kg) remarkably increased comet tail formation in bone marrow cells. Unexpectedly, the absence of antigenotoxicity was observed in three cotreated groups with A. nilotica extract and MNU compared with the MNU-treated group. Astonishingly, cotreatment with MNU and A. nilotica extract at a dose above 200 mg/kg remarkably increased micronucleus and comet tail formation in bone marrow cells compared with the MNU-treated group.
CONCLUSIONS
A. nilotica extract possessed anticancer activity with relative genotoxic effects at high doses.
Topics: Acacia; Animals; Antineoplastic Agents; DNA Damage; Flowers; Humans; Male; Methylnitrosourea; Mice; Plant Extracts
PubMed: 35934768
DOI: 10.1007/s11033-022-07662-0 -
Pathology Oncology Research : POR Apr 2020The anti-estrogenic and anti-cell proliferative effect of allyl isothiocyanate (AITC) was carried out by analyzing the status of sex hormones and its receptors and cell...
The anti-estrogenic and anti-cell proliferative effect of allyl isothiocyanate (AITC) was carried out by analyzing the status of sex hormones and its receptors and cell proliferative markers in chemically induced mammary carcinogenesis in rats. Mammary tumor was induced by a single dose of DMBA (25 mg/rat) and MNU (50 mg/kg bw) injected subcutaneously near mammary gland. RT-PCR, western blotting and immunohistochemical analysis of mammary tissues show an upregulation of ER-α, PR, aromatase, PCNA, cyclin D1 and AgNORs staining and down regulation of p53 expression as well as plasma estradiol, prolactin and testosterone levels increased in DMBA and MNU-induced tumor bearing rats. Oral administration of AITC at a dose of 20 mg/kg bw restored the levels of sex hormones and its receptors, aromatase, cell proliferative markers and AgNORs staining near to normal levels. Molecular docking studies also supported these findings. The results suggest that anti-estrogenic and anti-proliferative effect of AITC prevent the development of DMBA and MNU-induced mammary carcinogenesis in rat.
Topics: Animals; Anthracenes; Carcinogens; Cell Proliferation; Chemoprevention; Estrogen Receptor Modulators; Female; Isothiocyanates; Mammary Neoplasms, Experimental; Methylnitrosourea; Piperidines; Rats; Rats, Sprague-Dawley
PubMed: 30895454
DOI: 10.1007/s12253-019-00638-9 -
Frontiers in Molecular Neuroscience 2023In contrast to mammals, zebrafish can regenerate their damaged photoreceptors. This capacity depends on the intrinsic plasticity of Müller glia (MG). Here, we...
In contrast to mammals, zebrafish can regenerate their damaged photoreceptors. This capacity depends on the intrinsic plasticity of Müller glia (MG). Here, we identified that the transgenic reporter , a marker of regenerating fin and heart, also participates in retina restoration in zebrafish. After methylnitrosourea (MNU) treatment, the retina became deteriorated and contained damaged cell types including rods, UV-sensitive cones and the outer plexiform layer. This phenotype was associated with the induction of expression in a subset of MG until the reconstruction of the photoreceptor synaptic layer. Single-cell RNA sequencing (scRNAseq) analysis of regenerating retinas revealed a population of immature rods, defined by high expression of and the ciliogenesis gene , but low expression of phototransduction genes. Furthermore, cones displayed deregulation of metabolic and visual perception genes in response to retina injury. Comparison between expressing and non-expressing MG demonstrated that these two subpopulations are characterized by distinct molecular signatures, suggesting their heterogenous responsiveness to the regenerative program. Dynamics of ribosomal protein S6 phosphorylation showed that TOR signaling became progressively switched from MG to progenitors. Inhibition of TOR with rapamycin reduced the cell cycle activity, but neither affected expression in MG, nor prevented restoration of the retina structure. This indicates that MG reprogramming, and progenitor cell proliferation might be regulated by distinct mechanisms. In conclusion, the reporter detects activated MG, and provides a common marker of regeneration-competent cells in diverse zebrafish organs, including the retina.
PubMed: 37138703
DOI: 10.3389/fnmol.2023.1160707 -
Nature Genetics Feb 2020Somatic alterations in cancer genes are being detected in normal and premalignant tissue, thus placing greater emphasis on gene-environment interactions that enable...
Somatic alterations in cancer genes are being detected in normal and premalignant tissue, thus placing greater emphasis on gene-environment interactions that enable disease phenotypes. By combining early genetic alterations with disease-relevant exposures, we developed an integrative mouse model to study gastric premalignancy. Deletion of Trp53 in gastric cells confers a selective advantage and promotes the development of dysplasia in the setting of dietary carcinogens. Organoid derivation from dysplastic lesions facilitated genomic, transcriptional and functional evaluation of gastric premalignancy. Cell cycle regulators, most notably Cdkn2a, were upregulated by p53 inactivation in gastric premalignancy, serving as a barrier to disease progression. Co-deletion of Cdkn2a and Trp53 in dysplastic gastric organoids promoted cancer phenotypes but also induced replication stress, exposing a susceptibility to DNA damage response inhibitors. These findings demonstrate the utility of mouse models that integrate genomic alterations with relevant exposures and highlight the importance of gene-environment interactions in shaping the premalignant state.
Topics: Adenocarcinoma; Animals; Barrett Esophagus; Cell Line, Tumor; Cyclin-Dependent Kinase Inhibitor p16; Environmental Exposure; Esophageal Neoplasms; Humans; Methylnitrosourea; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Mutation; Neoplasms, Experimental; Organoids; Precancerous Conditions; Stomach Neoplasms; Tumor Suppressor Protein p53
PubMed: 32025000
DOI: 10.1038/s41588-019-0574-9 -
Cancer Prevention Research... Mar 2020In both estrogen receptor/progesterone receptor-positive (ER/PR) human breast cancer and in ER/PR cancers in the methylnitrosourea (MNU)-induced rat model, short-term...
In both estrogen receptor/progesterone receptor-positive (ER/PR) human breast cancer and in ER/PR cancers in the methylnitrosourea (MNU)-induced rat model, short-term modulation of proliferation in early cancers predicts preventive/therapeutic efficacy. We determined the effects of known effective/ineffective chemopreventive agents on proliferative index (PI) in both rat mammary epithelium and small cancers. Female Sprague-Dawley rats were treated with MNU at 50 days of age. Five days later, the rats were treated with the individual compounds for a period of 14 days. At that time, normal mammary tissue from the inguinal gland area was surgically removed. After removal, the rats remained on the agents for an additional 5 months. This cancer prevention study confirmed our prior results of striking efficacy with tamoxifen, vorozole, Targretin, and gefitinib, and no efficacy with metformin, naproxen, and Lipitor. Employing a separate group of rats, the effects of short-term (7 days) drug exposure on small palpable cancers were examined. The PI in both small mammary cancers and in normal epithelium from control rats was >12%. In agreement with the cancer multiplicity data, tamoxifen, vorozole, gefitinib, and Targretin all strongly inhibited proliferation (>65%; < 0.025) in the normal mammary epithelium. The ineffective agents metformin, naproxen, and Lipitor minimally affected PI. In the small cancers, tamoxifen, vorozole, and Targretin all reduced the PI, while metformin and Lipitor failed to do so. Thus, short-term changes in the PI in either normal mammary epithelium or small cancers correlated with long-term preventive efficacy in the MNU-induced rat model.
Topics: Animals; Anticarcinogenic Agents; Cell Proliferation; Epithelium; Female; Mammary Glands, Animal; Mammary Neoplasms, Experimental; Methylnitrosourea; Prognosis; Rats; Rats, Sprague-Dawley; Treatment Outcome
PubMed: 31871222
DOI: 10.1158/1940-6207.CAPR-19-0318 -
Journal of Toxicologic Pathology Apr 2022The retina consists of several layers, and drugs can affect the retina and choroid separately. Therefore, investigating the target layers of toxicity can provide useful...
The retina consists of several layers, and drugs can affect the retina and choroid separately. Therefore, investigating the target layers of toxicity can provide useful information pertaining to its modes of action. Herein, we compared gene expression profiles obtained via microarray analyses using samples of target layers collected via laser capture microdissection and samples of the whole globe of the eye of rats treated with -methyl--nitrosourea. Pathway analyses suggested changes in the different pathways between the laser capture microdissection samples and the whole globe samples. Consistent with the histological distribution of glial cells, upregulation of several inflammation-related pathways was noted only in the whole globe samples. Individual gene expression analyses revealed several gene expression changes in the laser capture microdissection samples, such as caspase- and glycolysis-related gene expression changes, which is similar to previous reports regarding -methyl--nitrosourea-treated animals; however, caspase- and glycolysis-related gene expressions did not change or changed unexpectedly in the whole globe samples. Analyses of the laser capture microdissection samples revealed new potential candidate genes involved in the modes of action of -methyl--nitrosourea-induced retinal toxicity. Collectively, our results suggest that specific retinal layers, which may be targeted by specific toxins, are beneficial in identifying genes responsible for drug-induced ocular toxicity.
PubMed: 35516843
DOI: 10.1293/tox.2021-0064 -
Scientific Reports Jun 2021This study aimed to investigate the impact of chronic low-level exposure to chemical carcinogens with different modes of action on the cellular response to ionising...
This study aimed to investigate the impact of chronic low-level exposure to chemical carcinogens with different modes of action on the cellular response to ionising radiation. Human lymphoblastoid GM1899A cells were cultured in the presence of 4-nitroquinoline N-oxide (4NQO), N-nitroso-N-methylurea (MNU) and hydrogen peroxide (HO) for up to 6 months at the highest non-(geno)toxic concentration identified in pilot experiments. Acute challenge doses of 1 Gy X-rays were given and chromosome damage (dicentrics, acentric fragments, micronuclei, chromatid gaps/breaks) was scored. Chronic exposure to 20 ng/ml 4NQO, 0.25 μg/ml MNU or 10 μM HO hardly induced dicentrics and did not significantly alter the yield of X-ray-induced dicentrics. Significant levels of acentric fragments were induced by all chemicals, which did not change during long-term exposure. Fragment data in combined treatment samples compared to single treatments were consistent with an additive effect of chemical and radiation exposure. Low level exposure to 4NQO induced micronuclei, the yields of which did not change throughout the 6 month exposure period. As for fragments, micronuclei yields for combined treatments were consistent with an additive effect of chemical and radiation. These results suggest that cellular radiation responses are not affected by long-term low-level chemical exposure.
Topics: 4-Nitroquinoline-1-oxide; Cell Line; Cell Survival; Chromosomes; Humans; Hydrogen Peroxide; Lymphocytes; Methylnitrosourea; Micronucleus Tests; Radiation Dosage; Radiation Tolerance; Time Factors
PubMed: 34135387
DOI: 10.1038/s41598-021-91957-y -
Asian Pacific Journal of Cancer... Oct 2020To analyze the effect of sirolimus and sunitinib in blocking the tumor growth and to evaluate the expressions of estrogen receptor (ER), progesterone receptor (PgR), and...
OBJECTIVE
To analyze the effect of sirolimus and sunitinib in blocking the tumor growth and to evaluate the expressions of estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor-2 (HER2/neu) after treated with sirolimus and sunitinib.
METHODS
Thirty-two female Sprague Dawley rats at age 21-days old were administered intraperitoneally with N-Methyl-N-Nitroso Urea (NMU), dosed at 70mg/kg body weight. The rats were divided into 4 groups; Group 1 (Control, n=8), Group 2 (Sirolimus, n=8), Group 3 (Sunitinib, n=8) and Group 4 (Sirolimus+Sunitinib, n=8), being treated twice when the tumor reached the size of 14.5±0.5 mm and subsequently sacrificed after 5 days. The protein expressions of ER, PgR and HER2/neu of the tumor tissues were evaluated by using immunohistochemistry analysis.
RESULTS
Treatment with sirolimus alone lowered expressions of ER and PgR of breast cancer and reduced tumor size. There was no significant difference of ER and PgR expressions between control and sunitinib treated tumor. Sunitinib treated tumors reduce in diameter after the first treatment, however the diameter increases after the second treatment. Histologically, sunitinib treated tumor did not show any aggressive invasive carcinoma of no special type (NST) histological subtypes. In addition, all NMU-induced tumors are HER2/neu-negative scoring.
CONCLUSION
Sirolimus is neither synergistic nor additive with sunitinib for breast cancer treatment.
.Topics: Alkylating Agents; Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Proliferation; Female; Mammary Neoplasms, Experimental; Methylnitrosourea; Rats; Rats, Sprague-Dawley; Receptor, ErbB-2; Receptors, Estrogen; Receptors, Progesterone; Sirolimus; Sunitinib
PubMed: 33112549
DOI: 10.31557/APJCP.2020.21.10.2919