DMBA-induced Tumors Research Articles

Cetuximab functionalized chitosan/hyaluronic acid-based nanoparticles loaded with cabazitaxel enhances anti-tumor efficacy in DMBA-induced breast cancer model in rats through spatial targeting

The article discusses the ionic gelation of cationic chitosan (CS) with anionic hyaluronic acid (HA) sodium salt to form nanoparticles in the range of 125 nm. The particles were further functionalized with cetuximab to endow it with the ability to spatially target the tumor over-expressing EGFR. Solid-state characterization of the particles using XRD, FTIR, and DSC revealed the formation of stable nanoparticles with Cabazitaxel loaded in the amorphous nanostructure. XPS study used to assess the surface characteristics indicated that the cetuximab was successfully anchored on the surface of the particle. The prepared CS-HA-Cmab-NP elicited a pH-responsive drug release behavior due to the presence of CS in the matrix. In vitro performance of the nanoparticles was evaluated on MDA-MB-231 breast cancer cell lines showed overall increase in efficacy. In vivo pharmacokinetic and anti-tumor effect evaluated in female Sprague Dawley rats indicated that the Cmab-conjugated nanoparticles improved half-life of cabazitaxel and tumor reduction capability with higher survival rate and lower reduction in body weight. The results indicate that CS/HA nanoparticles anchored with cetuximab show enhanced efficacy in reducing the breast cancer tumor in DMBA-induced breast tumor model through spatial targeting, consequently reducing the systemic toxicity.

Ethanolic extract of Euphorbia royleana Boiss. reduces metastasis of breast cancer cells and inhibits tumor progression in vivo.

Metastasis is the most devastating attribute of breast cancer (BC) that leads to high mortality. It is a complex process of tumor cell migration, invasion, and angiogenesis. In this study, we evaluated the effect of ERA on BC metastasis and BC progression in vivo. The transwell invasion/migration and wound healing assays showed that ERA treatment significantly reduced the invasion and migration of BC cell lines. The expression of mesenchymal (E-cadherin and N-cadherin), matrix metalloproteinases (MMP2, MMP9), and stemness markers (Oct3) were down-regulated by ERA. Furthermore, ERA down-regulated angiogenic chemokines (CXCL1/2/3, CXCL5, and CXCL12) expression in the highly metastatic MDA-MB-231 cell line. The clonogenic survival of BC cells was also reduced by ERA treatment. Strikingly, ERA prevented DMBA-induced tumor growth in Swiss albino mice as depicted by a high animal survival rate (84%) in the ERA group and histopathological analysis. Conclusively, this study revealed that ERA possesses anti-metastatic potential and also reduces the growth of BC in vivo. Moreover, the GC-MS data revealed the presence of biologically active compounds (Lupeol, Phytol, phytosterol) and some rare (9, 19-Cyclolanost) phyto metabolites in ERA extract. However, further studies are suggestive to identify and isolate the therapeutic agents from ERA to combat BC and metastasis.

Inflammation Factors and Genistein Supplementation in Cancer-Preliminary Research.

The purpose of this study was to evaluate the effect of genistein in nano, micro, and macro forms on the intensity of the DMBA-induced tumor process in rats and to understand the mechanisms of this action. The effect of genistein supplementation on the content of selected eicosanoids (HETEs, HODE, and HEPE) in the serum of rats was evaluated. The levels and expression of genes encoding various pro-inflammatory cytokines (IL-1, IL-6) and MMP-9 in the blood of rats were also investigated. The biological material for the study was blood obtained from female rats of the Sprague Dawley strain (n = 32). The animals were randomly divided into four groups: animals without supplementation, and animals supplemented at a dose of 0.2 mg/kg b.w. (0.1 mg/mL) with macro, micro (587 ± 83 nm), or nano (92 ± 41 nm) genistein. To induce mammary neoplasia (adenocarcinoma), rats were given 7,12-dimethyl-1,2-benz[a]anthracene (DMBA). The content of selected eicosanoids was determined by liquid chromatography with UV detection. An immunoenzymatic method was used to determine the content of cytokines and MMP-9. The expression of the IL-6, IL-1beta, and MMP-9 genes was determined with quantitative real-time PCR (qRT-PCR) using TaqMan probes. Based on the study, it was shown that supplementation of animals with genistein in macro, micro, and nano forms increased the intensity of the tumor process in rats. It was shown that the content of 12-HEPE, HODE, and 12-HETE in the serum of genistein-supplemented rats was statistically significantly lower with respect to the content of the aforementioned markers in the serum of rats receiving only a standard diet, devoid of supplementation. It was found that animals supplemented with nano-, micro-, and macrogenistein had higher levels of metalloproteinase-9, MMP-9, compared to animals without supplementation. There was a significant increase in MMP-9 gene expression in the blood of macrogenistein-supplemented animals, relative to the other groups of rats. On the basis of the study, it was shown that supplementation of animals with nano-, micro-, and macrogenistein had an effect on the development of the tumor process. Dietary supplementation with genistein significantly decreased the level of selected eicosanoids, which may have significant impacts on cancer development and progression.

Exploring the Protective Effect against 7,12-Dimethylbenz[a]anthracene-Induced Breast Tumors of Palmitoylethanolamide.

Breast cancer remains a global health burden, and the need for effective therapies is of chief importance. The current study explored the in vivo chemoprotective activity of palmitoylethanolamide (PEA) against 7,12-dimethylbenz[a]anthracene (DMBA)-induced breast tumor in rats. Results of noninvasive photoacoustic imaging showed real-time progression in the tumor area and volume in DMBA-induced rats, while there was a reduction in tumor area and volume in PEA-treated tumor-bearing rats. The increase in the average oxygen saturation (sO2 %) and decrease in the average total hemoglobin (HbT %) indicated the PEA-mediated attenuation of hypoxia-induced neovascularization in DMBA-induced rats. Histopathological investigations confirmed the efficacy of PEA in mitigating breast carcinoma, hepatotoxicity and nephrotoxicity driven by DMBA. Moreover, PEA-mediated alterations in the metabolic activity of the tumor microenvironment were evidenced by decreased glucose and lactate dehydrogenase enzyme level in the blood plasma and mammary tissue. PEA also maintained the redox balance by inhibiting nitric oxide level, reducing malondialdehyde (a product of lipid peroxidation), and increasing the level of antioxidant enzyme reduced glutathione. PEA altered the expression of apoptosis-related genes (BAX, P53,BCL-XL, CASPASE-8, and CASPASE-9) and induced the activity of Caspase-3 protein in the mammary tissue of tumor-bearing rats, indicating its apoptosis inducing ability. Taken together, the findings of this study suggest that PEA may have a protective effect against DMBA-induced breast tumors.

Dacarbazine-encapsulated solid lipid nanoparticles for skin cancer: physical characterization, stability, in-vivo activity, histopathology, and immunohistochemistry.

This study examined the use of solid lipid nanoparticles (SLNs) to administer Dacarbazine (DTIC) to skin melanoma cells with minimal adverse effects. Melanoma is a tricky skin cancer to cure, and standard chemotherapy has many negative effects. Encapsulating DTIC in SLNs may allow the drug to target melanoma cells without harming healthy cells. The study developed and tested DTIC-loaded SLNs for skin melanoma treatment. This study encapsulated Dacarbazine (DTIC) in solid lipid nanoparticles (SLNs). SLNs with reversed micelles were produced utilizing specified ratios of the surfactant Kolliphor® P188 and phosphatidylcholine. To track SLN drug localisation, gold nanoparticles were conjugated to the DTIC. Nanoparticle size and form were examined using DLS and TEM. These approaches ensured SLNs had the correct size and shape for drug delivery. In the study, various parameters of the developed solid lipid nanoparticles (SLNs) were evaluated, including particle size, zeta potential, polydispersity index (PDI), entrapment efficacy, and cumulative drug permeation. The values for these parameters varied across the different formulations, with particle size ranging from 146 ± 4.71 nm to 715 ± 7.36 nm, zeta potential from -12.45 ± 2.78 mV to -30.78 ± 2.83 mV, PDI from 0.17 ± 0.013 to 0.51 ± 0.023, entrapment efficacy from 37.78 ± 2.78% to 87.45 ± 4.78%, and cumulative drug permeation from 117 ± 4.77 μg/cm2 to 275 ± 5.67 μg/cm2. To determine the optimal anti-cancer formulation, the DTIC-SLNs-8 nanoparticles were mixed with an optimized concentration of Gellan gum (0.01% w/v) and applied to DMBA-induced skin tumors in rats for six weeks, twice daily. Histopathology demonstrated that DTIC-SLNs-8-treated rats had less keratosis, inflammatory responses, and angiogenesis than free DTIC-treated rats. The development of SLNs may be a promising approach for melanoma treatment due to their improved drug retention over the skin. The optimised anti-cancer formulation DTIC-SLNs-8 showed improved efficacy with minimal side effects as compared to free DTIC.

Abstract 5250: Effect of the β-blocker carvedilol in preventing DMBA-induced mammary gland tumor growth

Abstract According to global cancer statistics, breast cancer has now become the most diagnosed cancer and has become the fifth leading cause of cancer-related deaths worldwide. A promising method of retarding cancer-related mortality is cancer chemoprevention. However, there is no drug available that can be used routinely as a breast cancer-preventative agent. As carvedilol (CAR), an FDA-approved beta-adrenergic receptor blocker, reduces breast cancer mortality, we hypothesized that CAR might act as a breast cancer preventative agent. Three protocols were utilized to evaluate the ability of CAR to prevent 7,12-Dimethylbenz(a)anthracene (DMBA)-induced mammary tumors in rats. In protocol 1, two doses of CAR (2 and 10 mg/kg) were administered in drinking water as a 7-day pretreatment and throughout the study. In protocol 2, 10 mg/kg tamoxifen and 10 mg/kg carvedilol were provided as a 7-day pretreatment, and treatment was halted after six weeks. In protocol 3, CAR and the non-β-blocking enantiomer R-carvedilol (10 mg/kg) were given as a 7-day pretreatment and throughout the study. In all studies, animals were palpated weekly beginning at week 5 to detect the presence and location of mammary tumors. Tumors were measured using a caliper, and the experiments terminated at week 13. In protocol 1, only 10 mg/kg CAR was effective in delaying DMBA-mediated tumor occurrence (p = 0.0002); the first appearance of tumors and median tumor appearance in CAR-treated rats were separated from rats receiving DMBA alone by 2 and 4 weeks, respectively. However, tumors that did form grew at the same rate in all groups. In protocol 2, tamoxifen served as a control to prevent DMBA-mediated tumors; only one tamoxifen-treated rat developed a tumor at the end of the study. The tamoxifen-treated rats tumor formation was not statistically different than negative controls; however, the CAR group was not statistically different from the DMBA group. In protocol 3, CAR and R-CAR treatment showed delayed tumor formation and growth compared to the DMBA-only group, although not statistically significant. Combining all DMBA and 1-week pretreatment CAR data (n = 58 and 40, respectively), CAR effectively prevents DMBA-induced tumor incidence (p = 0.001), with a 3-week differential in the median tumor formation between the two groups. Therefore, continuous CAR treatment is essential to achieve the observed chemopreventive effects. As carvedilol is a clinically used beta-blocker, the results provide significant implications in breast cancer chemoprevention. Citation Format: Pabitra Kumar Sardar, Steven Yeung, Ayaz Shahid, Bradley T. Andresen, Ying Huang. Effect of the β-blocker carvedilol in preventing DMBA-induced mammary gland tumor growth. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5250.

Therapeutic effects of Vernonia amygdalina on the expression of hormone and HER2 receptors in 7, 12-dimethylbenz(a)anthracene-induced breast tumours in obese and non-obese Wistar rats

BackgroundObesity, a risk factor for breast cancer has been shown to be associated with poor response to neoadjuvant chemotherapy in women with breast cancer. Medicinal plants have been used to treat chronic diseases like cancer with little or no side effects. Vernonia amygdalina (VA) is a medicinal plant with anticancer activity. Previous studies on the anticancer potential of V. amygdalina against breast cancer are however entirely in vitro studies. The efficacy of V. amygdalina on obesity-associated breast cancer has also not been investigated in previous studies. This study explored VA’s anti-cancer effects on obesity- and non-obesity-associated 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast tumours in Wistar rats (WRs). MethodThirty female obese and non-obese WRs were studied, each group divided into six subgroups of five. At the 7th postnatal week (p.w), three subgroups were given a subcutaneous injection of DMBA to the breast with two of these three subgroups also commenced on daily oral VA at 250 mg/kg and 500 mg/kg from the 9th p.w. Same doses of VA were administered to two of the subgroups that did not receive DMBA while the last subgroup was placed on placebo from the 9th p.w. Haematoxylin and eosin staining were carried out on the excised breast tumours to evaluate general histoarchitecture, while immunohistochemistry was done for oestrogen (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER2) expression. ANOVA and Mann-Whitney followed by posthoc tests were used to analyse the data. Alpha level was set at 0.05. ResultsWhile the DMBA-induced tumours were triple-negative in the obese WRs, they were ER, PR HER2-positive in the non-obese group. Vernonia amygdalina was associated with a reduction in cancer cell proliferation in both obese and non-obese groups despite the differences in immunohistochemical profiles of the tumours. Vernonia amygdalina was associated with reversal of the increased ER, PR and HER2 expressions in the breast tumours of the non-obese rats. ConclusionsConclusively, VA had more therapeutic effects on DMBA-induced breast tumours in the non-obese than obese WRs.

Inhibition of Dimethylbenz[a]anthracene-Induced Breast Tumors in Rats by Soy Protein is Mediated by Downregulation of MAPK/AP-1 Signaling

We reported earlier that replacement of casein by soy protein in the diets of rats exposed to the carcinogen, dimethylbenz[a]anthracene (DMBA), not only delayed the initiation of breast tumor but also had a protective effect against the development of aggressive tumor. The aim of this study was to elucidate the molecular mechanism by which soy protein offers these beneficial effects. Tumor was developed by gavage administration of single dose of 80 mg/kg of DMBA into 50-day old female rats, maintained on a standard AIN-76A diet containing either casein or soy protein. After ~120 days of DMBA administration, we evaluated the role of MAPK phosphorylation and subsequent AP-1 activation on the differential effects of soy protein and casein on the development of aggressiveness and progression of DMBA-induced breast tumor and determined if soy protein controls MMP-9 and uPAR expression by modifying AP-1 activity. The present study demonstrates that the beneficial effect of soy protein in breast tumor development is mediated by control of MAPK/AP-1 signaling. It is concluded that deactivation of MAPK pathway lead to down-regulation of the AP-1 activation which in turn down regulates the target gene and may be responsible for controlling breast tumor aggressiveness. Thus, it is suggested that MAPKs (ERK, p38 and JNK), MMP-9 and uPAR may be a potential target for anticancer therapy inhibiting tumor vasculature and invasion stimulated by tumor-associated stroma, and regulating the target gene and may be responsible for the beneficial effects of soy protein.

Reduction of Tumor Formation in GABARAP Knockout Mice is Associated with Absence of H-ras Mutation

GABARAP gene has an essential role in the autophagic process through its involvement in the maturation of the autophagosome. The role of GABARAP in tumorigenesis is not yet clarified. It is ubiquitously expressed in all tested normal tissues, while its expression in tumors is divers. Autophagy could induce by Oncogenic Ras to handle the metabolic stress and support cell survival. In this study, we found that GABARAP knockout mice exhibited significantly less tumor formation than wild-type mice after 7,12-dimethylbenz(a)anthracene treatment. Different types of tumor developed in the mice (skin, mammary, lymphoma and liver tumors). Furthermore, the tumor occurrence started earlier in wild-type mice compared to GABARAP knockout animals, and the tumor sizes in wild-type mice were obviously larger in most of induced tumors compared to the tumors formed in GABARAP KO mice. No H-ras mutation detected in the tumors of GABARAP knockout mice compared to 5 mutations in 14 tumors of the wild-type mice which revealed by mutation analysis of tumors induced by DMBA. In conclusion, the absence of H-ras mutation in DMBA-induced tumors of GABARAP KO mice indicates the significance of GABARAP gene in tumor progression that need further studies to clarify the exact role.

N-(benzylidene)-2-((2-hydroxynaphthalen-1-yl)diazenyl)benzohydrazides (1-2) (NCHDH and NTHDH) attenuate DMBA-induced breast cancer via Nrf2/NF-κB/apoptosis signaling.

The present study investigated the effect of the N-(benzylidene)-2-((2-hydroxynaphthalen-1-yl)diazenyl)benzohydrazides (1-2) (NCHDH and NTHDH) against breast cancer using in vitro and in vivo approaches. The NCHDH and NTHDH significantly inhibited the growth of the MCF-7 cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The NCHDH and NTHDH treatment significantly inhibited the tumor size, tumor weight, and tumor volume, while it enhanced the survival and tumor free survival rate following 7,12-Dimethylbenz[a]anthracene (DMBA)-induced breast cancer. The NCHDH and NTHDH markedly attenuated the oxidative stress markers and induced the antioxidant level. The enzyme-linked immunosorbent assay (ELISA) showed significant reduction in the inflammatory cytokines production compared with the DMBA control. The NCHDH and NTHDH treatment significantly improved the histological features using hematoxylin and eosin (H and E) staining, Masson's trichrome, PAS (periodic acid Schiff), and Toluidine blue staining compared with the DMBA-induced group. The NCHDH and NTHDH treatment improved the hematological and serological parameters following DMBA-induced breast tumor compared with DMBA-induced group. Furthermore, the NCHDH and NTHDH treatment significantly enhanced the antioxidants signaling proteins such as nuclear factor erythroid 2-related factor 2 (Nrf2) and Heme oxygenase 1 (HO-1). The NCHDH and NTHDH enhanced the inhibitor of NF-κB (IκB) level, while it attenuated the NF-κB level. Similarly, the NCHDH and NTHDH showed marked increase in the apoptosis proteins such as Caspase-3, Caspase-9, and Bcl-2 Associated X-protein (Bax), while it inhibited the B-cell lymphoma 2 (Bcl-2) expression. In conclusion, the NCHDH and NTHDH significantly improved the DMBA-induced breast cancer via attenuating oxidative stress and inflammatory cytokines.

The Unique Genetic and Histological Characteristics of DMBA-Induced Mammary Tumors in an Organoid-Based Carcinogenesis Model.

Here, we report a model system using in vitro 7,12-dimethylbenz[a]anthracene (DMBA; 0.6 μM)-treated mammary tissue-derived organoids generated from heterozygous BALB/c-Trp53 knockout mice to induce tumors after injection into the nude mouse subcutis. In parallel, a single oral dose of DMBA (50 mg/kg bodyweight) to the same murine strain induced mammary adenocarcinomas, characterized by biphasic structures differentiated into luminal and myoepithelial lineages and frequent Hras mutations at codon 61. In the present study, the genetic and histological characteristics of DMBA-induced tumors in the organoid-based model were evaluated to validate its similarities to the in vivo study. The organoid-derived tumors were low-grade adenocarcinomas composed of luminal and basal/myoepithelial cells. When the organoid-derived carcinomas were passaged to other nude mice, they partly progressed to squamous cell carcinomas (SCCs). Whole exome sequencing revealed no mutations at Hras codon 61 in the organoid-derived tumors. However, various mutations were detected in other genes such as Tusc3 and Tgfbr2, which have been reported as cancer-associated or homeostatic squamous cell genes. The most common mutational pattern observed in these genes were the G:C to T:A transversions and G:C to A:T transitions, which are not typical of the mutations caused by DMBA treatment. In conclusion, DMBA exhibited carcinogenicity in the both the ex vivo and in vivo mammary carcinogenesis models, albeit with distinct histological and genetical alterations. Further studies are needed to clarify whether organoid-based carcinogenesis models generated following chemical treatment in vitro could be applied to the clarification of the novel mode of action of chemical carcinogenesis.

Hybrid Quinazoline 1,3,5-Triazines as Epidermal Growth Factor Receptor (EGFR) Inhibitors with Anticancer Activity: Design, Synthesis, and Computational Study.

We report a series of hybrid quinazoline-1,3,5-triazine derivatives as EGFR inhibitors, which were synthesised and tested by using a variety of in vitro, in silico, and in vivo techniques. The derivatives were found to be active against different cancer cell lines and nontoxic against normal ones, with compounds 7 c, 7 d, 7 e, and 7 j being the most potent ones. The derivatives were also evaluated for angiogenesis inhibition potency in chicken eggs, and molecular docking and dynamics simulation studies were carried out to elucidate the fundamental substituent groups essential for their bioactivity. Additionally, a SAR study of the derivatives was performed for future compound optimisation. These studies suggested that the derivatives have a high affinity towards EGFR with favourable pharmacological properties. The most active compound (7 e) was further evaluated for in vivo anticancer activity against DMBA-induced tumours in female Sprague-Dawley rats as well as its effects on plasma antioxidant status, biotransformation enzymes, and lipid profile. The study suggested that 7 e has lead properties against breast cancer and can serve as a starting compound for further development of anti-EGFR compounds.

Abstract 15259: Breast Cancer and Heritable Pah Due to Bmpr2 Mutation: An Unexpected Discovery

Introduction: BMPR2 mutation is reported in 80% of familial PAH and 20% of idiopathic cases. Recently, a rat model of hereditary Pulmonary Arterial Hypertension with a BMPR2 loss-of-function mutation has been generated. Similarly to human, only around 20% of the rats spontaneously developed mild PAH. Unexpectedly, we observed that 20% (95%CI:12-28) of the 82 Bmpr2+/Δ71 rats (93% of females) versus 4% (95%CI:0-9)of the 84 age-matched wild type littermates spontaneously developed mammary masses requiring euthanasia. Interestingly, rats with tumor had elevated PA and clearly exhibit PAH signs. Hypothesis: We hypothesized that mammary tumor exacerbates the penetrance of PAH in the BMPR2 mutated female rats. Methods/Results: BMPR2 mutated and wild-type female young rats were treated with the breast cancer inducer 7, 12- diméthylbenz(a)anthracene (DMBA) or Vehicle. DMBA causes on average more tumors development in BMPR2 mutated rats versus WT rats (6,2 vs. 4) P=0,0275. Compare to both vehicle-treated and DMBA rats (without tumor) BMPR2 mutated rats with DMBA-induced tumors had a significant increase in mean PA pressure (p<0,0001); total pulmonary resistance (p<0,0001) and a significant decrease in cardiac output (P=0,0293). Histologically, these changes were associated with an increase of pulmonary artery remodelling assessed by immunofluorescence. Mechanistically, development of PAH in the BMPR2 mutated rats with tumor was associated with a significant upregulation of BRD4 (western blot) (p=0,0149); IL-1β (P=0,0052), BRD3 (P=0,0791) and BIRC5 (P=0,0166) mRNA expression levels. Co-culture experiments with breast cancer cells and PASMC from both WT and BMPR2 mutated rats are ongoing to identify whether cancer cells are realising factors responsible for BRD4 activation and thus PASMC proliferation and resistance to apoptosis. Conclusions: We demonstrated for the first time that breast cancer exacerbates PAH development in BMPR2 mutated rats. Increased BRDs driven pro-inflammatory signalling is associated with PAH development in BMPR2 mutated rats. We are currently exploring whether BMPR2 mutated patients are more prone to breast cancer development or not and whether PAH development occurs more frequently in breast cancer patients.

Anticancer activity of a 1,4-dihydropyridine in DMBA-induced mouse skin tumor model.

Antitumor potential of a 1,4-dihydropyridine derivative (DHP-8) has been successfully studied previously in a number of cancer cell lines including the human melanoma cells, A375. In order to validate its anticancer activity, DMBA induced tumor in Swiss Albino mice was considered for this study. DMBA causes skin carcinoma in murine systems and is an important in vivo model for evaluating the efficacy of any new chemical entity against skin cancer. Topical administration of DHP-8 at the dose rate of 33.3 and 50.0 mg/kg body weight showed a significant reduction in tumor parameters. It also prevented the progression and differentiation of squamous cell carcinoma, as evidenced from histopathological studies. Immunohistochemical analysis for the expression of Ki67 indicated that it also reduced cancer cell proliferation. Additionally, it induced apoptosis in the tumor cells by activation of Caspase3. Our results indicated that DHP-8 efficiently attenuated DMBA induced tumor progression and it could be a potent therapeutic agent for skin cancer treatment.

Anticancer activity of Astragalus ovinus against 7, 12 dimethyl benz (a) anthracene (DMBA)-induced breast cancer in rats.

Some species of Astragalus are used for the treatment of various types of cancer. The present study was designed to evaluate the anticancer potential of Astragalus ovinus extract (AOE) against DMBA-induced breast carcinoma in rats. The anti-tumor and antioxidant effects of AOE were evaluated against DMBA-induced breast carcinoma in rats using DPPH, FRAP and ABTS technique, respectively. Forty adult female Sprague-Dawley rats were randomly divided into four groups including the control group received a single dose of DMBA solvent orally, and groups II, III and IV received a single dose of DMBA (40 mg/kg) dissolved in olive oil. Groups I and II received normal saline and groups III and IV were treated with AOE orally (120 and 240 mg/kg respectively) for 60 consecutive days. Chemopreventive effects were assessed in terms of diameter and volume of tumors, expression levels of PCNA, and serum levels of CA15.3, p53, MDA, CAT, and calcium, and histopathological features. AOE contained a noticeable amount of phenolic and flavonoids compounds. This extract showed a potent antioxidant activity both in vitro and in vivo. AOE significantly decreased the diameter and volume of tumors (p<0.01) and reduced the serum levels of CA15.3 (p<0.001), p53 (p<0.01), MDA (p<0.001), and calcium (p<0.01). AOE also decreased the expression of PCNA in cancerous tissues and reduced the histopathological deformity. According to the data, AOE produced a significant chemopreventive activity in DMBA-induced breast tumors in rats, probably due to its antioxidant and its inhibitory effect on some tumorigenicity markers such as CA15.3, p53 and PCNA activity.

Fucoxanthin modulates the development of 7, 12-dimethyl benz (a) anthracene-induced skin carcinogenesis in swiss albino mice in vivo

Background: Fucoxanthin (Fx), an distinctive carotenoid occurs on brown seaweed, contains several benefits including anti-cancer effects. To investigate the chemopreventive effectual of Fx on 7,12-dimethylbenz[a] anthracene (DMBA)-alone skin tumor development in Swiss albino mice. Materials and Methods: The skin sarcoma being provoked on the hairless flipside of the mice's skin, twice weekly for 8 weeks through challenging through DMBA (25 μg on 0.1 ml acetone/mice). Thereafter, the mice were oral supplementation with 50 mg/kg body weight (BW), Fx for 25th week a frequency of three times/week. Tumor size, change in BW, the cumulative quality of papillomas and some oxidative stress-related parameters were measured. Results: Orally administered Fx were notably increased BW, delayed tumor incidence with no abnormal pathology in DMBA-induced skin tumor mice. Fx effectively modulates the level of xenobiotic enzymes, brought back to the statuses of lipid peroxidation (LPO) enzymes and increased antioxidant enzymes status in squamous cell carcinomas (SCC). A considerable decrease in the protein expression of proinflammatory markers that is interleukin (IL) 1-6, tumor necrosis factor-alpha (TNF-α), and IL-β and restored the expression status of inflammatory regulators such as nuclear factor-kappa B (NF-κB), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) on serum. These findings were supported through histopathological examinations. Hence, it was clear that Fx possessed a good anticancer activity against skin cancer. Conclusion: The chemopreventive prospective of Fx was eventually owing to its altering capacity on the levels of proinflammatory (IL 1-6, TNF-α, and IL-β) cytokines, inflammatory (NF-κB, COX-2, and iNOS) markers, LPO, antioxidants, and toxin-eliminating mediators in DMBA-provoked skin SCC. Thus, it can be concluded that the FX indicates the antitumor potential on DMBA challenged skin tumor proliferation model on mice.

Cancer Chemopreventive effect of Rodent Tuber (Typhonium flagelliforme (Lood) Bl) against DMBA-Induced Rats Breast Tumor

Cancer Chemopreventive effect of Rodent Tuber (Typhonium flagelliforme (Lood) Bl) against DMBA-Induced Rats Breast Tumor

Effects of Hexane Root Extract of Ferula hermonis Boiss. on Human Breast and Colon Cancer Cells: An In Vitro and In Vivo Study.

Breast and colon cancers are leading causes of cancer-related deaths globally. Plants are a potential source of natural products that may be used for the treatment of cancer. Ferula hermonis (FH) is reported to have diverse therapeutic effects. However, there are few reports on the in vitro anticancer potential of FH extract. Our results showed that the Ferula hermonis root hexane extract (FHRH) can induce dose-dependent cytotoxic effects in breast and colon cancer cells with MTT IC50 values of 18.2 and 25 μg/ml, respectively. The FHRH extract induced apoptosis in both breast and colon cancer cells; this was confirmed by light and nuclear staining, q-PCR, and caspase 3/7 activation. This study also demonstrated the antitumor activity of FHRH in 9,10-dimethylbenz[α]anthracene DMBA-induced rodent mammary tumor model. The GC/MS analysis revealed the presence of 3,5-Dimethylbenzenemethanol, Alpha-Bisabolol, Alpha-pinene, Beta-pinene, and Baccatin III that have various pharmacological potentials. Overall, the present study suggests that FHRH extract possesses anticancer potential which is mediated through apoptotic effects in MDA-MB-231 and LoVo cells. The present study also considered a basis for further investigations into the potential use of FHRH extract as an anticancer therapy for breast and colon cancers.

Tyrosine Kinase Inhibitor Imatinib Mesylate Alters DMBA-Induced Early Onco/Suppressor Gene Expression with Tissue-Specificity in Mice.

Tyrosine kinases play crucial roles in cellular development and tumorigenesis. Tyrosine kinase inhibitors (TKIs) are effective and widely used drug molecules in targeted cancer therapies. Altered expressions of protooncogenes and tumor suppressor genes after DMBA (7,12-dimethylbenz[a]anthracene) treatment have been described as early markers of tumor induction; however their tissue-specific effects remain still unclear. Our study was aimed at examining the short-term possible antineoplastic and chemopreventive effects of a TKI compound (imatinib mesylate) on a DMBA-induced mouse tumor model. In addition, we also investigated the tissue-specific expressions of Hras, Kras, Myc, and Trp53 genes in the brain, bone marrow, spleen, liver, abdominal lymph nodes, thymus, lungs, and kidneys, respectively. 24 hours after the imatinib mesylate injection, we observed significant Kras downregulation in the bone marrow and lung of the DMBA-treated mice. Moreover, the mRNA expression of Myc was also found to be decreased significantly in the spleen. Interestingly, while Trp53 expression was significantly increased in the lung, it was decreased in the other tissues. However, there was also a tendency in the decreased Myc level in the bone marrow, brain, kidneys, lungs, and lymph nodes and in the decreased Hras level in the bone marrow, kidneys, and lungs, although no significant differences were observed. Our findings indicate rapid tissue-specific impact of imatinib mesylate on DMBA-induced gene expression in vivo, supporting the chemopreventive potential of imatinib mesylate in cancer.

PO-300 CIP2A-mediated regulation of senescence in basal-like breast cancer

IntroductionBasal-like breast cancer (BLBC) is an aggressive breast cancer molecular subtype, and it lacks efficient therapy options. Expression levels of oncoprotein CIP2A are increased in BLBC as compared to other breast cancer subtypes. Our results demonstrate that high CIP2A expression significantly predicts poor patient survival in triple negative breast cancer, that constitutes a major subset of BLBC. CIP2A inhibition also significantly impairs tumour growth of human BLBC xenografts. Previously, we have shown that CIP2A promotes breast cancer by inhibiting senescent growth arrest (Laine et al. Cancer Discov 2013). Induction of senescence and senescence associated secretome (SASP) has been shown to alter function of tumour infiltrating immune cells. Based on this we hypothesise that in addition to effects of CIP2A-mediated senescence inhibition to tumour cell-intrinsic mechanisms, it may impact infiltrating immune cells and thus therapy response.Material and methodsTo investigate the role of CIP2A in BLBC a carcinogen DMBA-induced tumour formation approach in Cip2a-/- mouse model was applied. In order to test our hypothesis about the effect of CIP2A-targeted senescence in immune cells we have set up mouse mammary tumour cell and organoid cultures from a spontaneous BLBC genetically engineered mouse model K14Cre;Brca1fl/fl;Tp53fl/fl. These cultures are genetically manipulated by CRISPR/Cas9 system to knock out CIP2A both prior to transplantation into recipient mice and in established tumours. To validate the in vivo findings we are using several different human breast cancer patient cohorts.Results and discussionsOur results demonstrate that CIP2A-deficient mice are severely impaired in a formation of DMBA-induced basal-like mammary tumours. Together with the clinical data, these results suggest that CIP2A is a novel driver oncoprotein, and a potential therapeutic target, in human BLBC. In addition, we have validated the tumour cell-intrinsic role of CIP2A in K14Cre;Brca1fl/fl;Tp53fl/fl BLBC mouse model as loss of CIP2A induces senescent growth arrest in mammary gland tumour cells in vitro. Currently, we are studying the interplay between the immune system and CIP2A-inhibited tumours in vitro and in vivo.ConclusionOverall, this study will address feasibility of CIP2A targeting as a novel approach to combat basal-like breast cancer. Results of this project will also enhance our general understanding of cross-talk between senescent cancer cells and the tumour environment in this clinically challenging human cancer type.