-
Carcinogenesis Feb 2021More than a million cases of cutaneous squamous cell carcinoma are diagnosed in the USA each year, and its incidence is increasing. Most of these malignancies arise from...
More than a million cases of cutaneous squamous cell carcinoma are diagnosed in the USA each year, and its incidence is increasing. Most of these malignancies arise from premalignant lesions, providing an opportunity for intervention before malignant progression. We previously documented how cytoplasmic mislocalization of CDC25A in premalignant and malignant skin cancers confers resistance to apoptotic cell death via a mechanism that depends on its interaction with 14-3-3ε. From these data, we hypothesized that 14-3-3ε overexpression drives skin tumor development and progression, such that targeting 14-3-3ε may be a useful strategy for skin cancer treatment. Like CDC25A, 14-3-3ε was overexpressed and mislocalized to the cytoplasm of both benign and malignant human skin cancer. Skin-targeted deletion of the 14-3-3ε gene reduced skin tumor development by 75% and blocked malignant progression. 14-3-3ε suppressed apoptosis through activation of Akt, leading to inhibition of BCL2 associated agonist of cell death and upregulation of Survivin. Using virtual tetrapeptide libraries, we developed a novel peptide that specifically blocked 14-3-3ε heterodimerization and thereby prevented its interaction with CDC25A. The peptide reduced prosurvival signaling, killed skin cancer cells and reduced skin tumor growth in xenograft. Normal skin keratinocytes were unaffected by inhibition or deletion of 14-3-3ε. Thus, targeting of 14-3-3ε dimerization is a promising strategy for the treatment of premalignant skin lesions.
Topics: 14-3-3 Proteins; 9,10-Dimethyl-1,2-benzanthracene; Animals; Antineoplastic Agents; Apoptosis; Carcinogens; Carcinoma, Squamous Cell; Cell Line, Tumor; Cytoplasm; Female; Humans; Keratinocytes; Male; Mice; Mice, Knockout; Neoplasms, Experimental; Protein Multimerization; Skin Neoplasms; Tetradecanoylphorbol Acetate; Xenograft Model Antitumor Assays; cdc25 Phosphatases
PubMed: 32816038
DOI: 10.1093/carcin/bgaa091 -
The Journal of Investigative Dermatology Apr 2021Integrin α3β1 plays a crucial role in tumor formation in the two-stage chemical carcinogenesis model (DMBA and TPA treatment). However, the mechanisms whereby the...
Integrin α3β1 plays a crucial role in tumor formation in the two-stage chemical carcinogenesis model (DMBA and TPA treatment). However, the mechanisms whereby the expression of α3β1 influences key oncogenic drivers of this established model are not known yet. Using an in vivo mouse model with epidermal deletion of α3β1 and in vitro Matrigel cultures of transformed keratinocytes, we demonstrate the central role of α3β1 in promoting the activation of several protumorigenic signaling pathways during the initiation of DMBA/TPA‒driven tumorigenesis. In transformed keratinocytes, α3β1-mediated focal adhesion kinase/Src activation leads to in vitro growth of spheroids and to strong Akt and STAT 3 activation when the α3β1-binding partner tetraspanin CD151 is present to stabilize cell‒cell adhesion and promote Smad2 phosphorylation. Remarkably, α3β1 and CD151 can support Akt and STAT 3 activity independently of α3β1 ligation by laminin-332 and as such control the essential survival signals required for suprabasal keratin-10 expression during keratinocyte differentiation. These data demonstrate that α3β1 together with CD151 regulate the signaling pathways that control the survival of differentiating keratinocytes and provide a mechanistic understanding of the essential role of α3β1 in early stages of skin cancer development.
Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Carcinogens; Cell Adhesion; Cell Adhesion Molecules; Cell Line; Cell Survival; Cell Transformation, Neoplastic; Epidermis; Humans; Integrin alpha3beta1; Keratinocytes; Mice; Neoplasms, Experimental; Signal Transduction; Skin Neoplasms; Spheroids, Cellular; Tetradecanoylphorbol Acetate; Tetraspanin 24; Kalinin
PubMed: 32805217
DOI: 10.1016/j.jid.2020.07.024 -
Methods in Cell Biology 2021Mice are the most important animals to model tumor formation and malignant progression in humans. Chemical induction of skin tumors in mice by treatment with DMBA and...
Mice are the most important animals to model tumor formation and malignant progression in humans. Chemical induction of skin tumors in mice by treatment with DMBA and TPA is a well-studied tumor induction model that is easy to use and directly applicable to genetically modified mice without any mandatory crossing with mice carrying mutations in oncogenes and tumorsuppressors. This article describes the basic protocol for DMBA/TPA induced skin tumor formation and discusses the advantages and limitations of this model, in particular the translatability of results obtained in this system to human cancer patients.
Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Humans; Mice; Skin Neoplasms; Tetradecanoylphorbol Acetate
PubMed: 33785160
DOI: 10.1016/bs.mcb.2020.08.004 -
Proceedings of the National Academy of... Mar 2021High levels of the intermediate filament protein keratin 17 (K17) are associated with poor prognoses for several human carcinomas. Studies in mouse models have shown...
High levels of the intermediate filament protein keratin 17 (K17) are associated with poor prognoses for several human carcinomas. Studies in mouse models have shown that K17 expression is positively associated with growth, survival, and inflammation in skin and that lack of K17 delays onset of tumorigenesis. K17 occurs in the nucleus of human and mouse tumor keratinocytes where it impacts chromatin architecture, gene expression, and cell proliferation. We report here that K17 is induced following DNA damage and promotes keratinocyte survival. The presence of nuclear K17 is required at an early stage of the double-stranded break (DSB) arm of the DNA damage and repair (DDR) cascade, consistent with its ability to associate with key DDR effectors, including γ-H2A.X, 53BP1, and DNA-PKcs. Mice lacking K17 or with attenuated K17 nuclear import showed curtailed initiation in a two-step skin carcinogenesis paradigm. The impact of nuclear-localized K17 on DDR and cell survival provides a basis for the link between K17 induction and poor clinical outcomes for several human carcinomas.
Topics: 9,10-Dimethyl-1,2-benzanthracene; Active Transport, Cell Nucleus; Animals; Carcinogenesis; Carcinoma; Cell Nucleus; Cell Survival; DNA Breaks, Double-Stranded; DNA Repair; Female; Gene Knockout Techniques; HeLa Cells; Humans; Intravital Microscopy; Keratin-17; Keratinocytes; Keratins; Male; Mice, Knockout; Neoplasms, Experimental; Time-Lapse Imaging; Mice
PubMed: 33762306
DOI: 10.1073/pnas.2020150118 -
Investigational New Drugs Dec 2021Pancreatic cancer is among the most refractory malignancies with poor prognosis. Thus, preventive approaches, in addition to the development of novel therapeutic...
Pancreatic cancer is among the most refractory malignancies with poor prognosis. Thus, preventive approaches, in addition to the development of novel therapeutic strategies are essential for this type of cancer. KRAS mutations occur very early in the development of pancreatic cancers and could be targeted for its prevention, yet specific inhibitors for mutated KRAS are lacking. Accordingly, Glutathione-S Transferase p1 (GSTP1), which we recently found to be an autocrine stimulator of mutated KRAS signaling, is predicted to be an alternative target for chemoprevention of pancreatic cancer. In this study, chemopreventive effects of O-Hexadecyl-γ-glutamyl-S-benzyl-cysteinyl-D-phenyl glycine-Ethylester (HGBPE), which we previously synthesized to inhibit GSTP1 activity, was analyzed for its effect on the prevention of a rat pancreatic carcinogenesis model induced by 7,12-dimethyl-benzanthracene (DMBA). Rats administered with DMBA were grouped into five cohorts. In the treated group I, which was treated neither with HGBPE nor vehicle, sequential appearance of precancerous lesions, ductal complexes, and adenocarcinoma was confirmed as previously reported. We also confirmed in this group that mutations of KRAS and expression of GSTP1 simultaneously occurred in the ductal complex. To rats of groups II and IV, HGBPE was administered, and vehicle to those of group III and V. In groups of II and IV, the incidence of both ductal complex and adenocarcinoma were significantly lower than those in groups III and V. These data clearly suggest the efficacy of HGBP as a potential chemopreventive agent for pancreatic cancer.
Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Disease Models, Animal; Glutathione S-Transferase pi; Pancreatic Neoplasms; Proto-Oncogene Proteins p21(ras); Rats; Rats, Sprague-Dawley; Signal Transduction
PubMed: 34031785
DOI: 10.1007/s10637-021-01129-y -
Molecular Therapy Oncolytics Dec 2021Pancreatic ductal adenocarcinoma (PDAC) is one of the most refractory and fatal human malignancies. Leucine-rich repeat neuronal protein-1 (LRRN1) plays a crucial role...
Pancreatic ductal adenocarcinoma (PDAC) is one of the most refractory and fatal human malignancies. Leucine-rich repeat neuronal protein-1 (LRRN1) plays a crucial role in the development of the nervous system. However, the clinical implications and biological functions of LRRN1 in PDAC remain unclear. We found that LRRN1 expression was upregulated in PDAC tissues compared with paracancerous tissues and normal pancreatic tissues through the different public databases, tissue microarray-based immunohistochemistry, and dimethylbenzanthracene-induced PDAC murine model. The expression level of LRRN1 was closely related to the overall survival and disease-free survival of PDAC patients. Cox multivariate analysis indicated that LRRN1 was an independent adverse prognostic factor. The small hairpin RNA (shRNA)-mediated LRRN1 knockdown remarkably restrained the proliferative, migratory, and invasive capacities, as well as promoted cell apoptosis and increased G0/G1 arrest in PDAC cells. The xenograft murine subcutaneous bearing model and metastasis model verified that silencing of LRRN1 effectively dampened tumor growth and metastasis . Specifically, LRRN1 exerted its biological functions through the HIF-1α/Notch signaling pathway, and LRRN1 knockdown could dampen Jagged 1-mediated Notch pathway activation. Therefore, LRRN1 could serve as the potential therapeutic or prognostic target for PDAC.
PubMed: 34632050
DOI: 10.1016/j.omto.2021.08.012 -
Annales Pharmaceutiques Francaises Jun 2023The present study aimed to evaluate the effect of metformin pretreatment on the potentiation of antiproliferative action of doxorubicin against breast cancer.
OBJECTIVES
The present study aimed to evaluate the effect of metformin pretreatment on the potentiation of antiproliferative action of doxorubicin against breast cancer.
MATERIAL AND METHODS
Female Wistar rats were administered with 7,12-Dimethylbenz(a)anthracene (DMBA) (35mg) in 1mL olive oil subcutaneously beneath the mammary gland. Animals were pretreated with metformin (Met) 200mg/kg two weeks before DMBA administration. DMBA control groups received doxorubicin (Dox) (4mg/kg and 2mg/kg), Met (200mg/kg) alone and in combination with Dox (4mg/kg). Met pre-treated DMBA control groups received Dox 4mg/kg and 2mg/kg.
RESULTS
Met pre-treated groups treated with Dox exhibited a decrease in tumor incidence, tumor volume and increased survival rate than the DMBA group. Organ-to-body weight ratios and histopathology of heart, liver and lungs of Met pre-treated groups treated with Dox showed lesser toxicity than Dox treated DMBA control groups. There was a noteworthy decrease in malondialdehyde levels and a substantial increase in the levels of reduced glutathione together with a significant decrease in the levels of inflammatory markers like IL-6, IL-1β and NF-κB in Met pre-treated groups treated with Dox. Histopathology of breast tumors revealed better control of tumors in Met pre-treated groups treated with Dox than DMBA control group. Immunohistochemistry and real-time PCR data revealed a significant reduction in Ki67 expression in Met pre-treated groups treated with Dox as compared to the DMBA control group.
CONCLUSION
The present study suggests that metformin pretreatment potentiates the antiproliferative action of doxorubicin against breast cancer.
Topics: Rats; Animals; Female; 9,10-Dimethyl-1,2-benzanthracene; Metformin; Rats, Wistar; Doxorubicin; Neoplasms
PubMed: 36907329
DOI: 10.1016/j.pharma.2023.03.001 -
International Journal of Molecular... Apr 2023Five million non-melanoma skin cancers occur globally each year, and it is one of the most common malignant cancers. The dysregulation of the endocannabinoid system,...
Five million non-melanoma skin cancers occur globally each year, and it is one of the most common malignant cancers. The dysregulation of the endocannabinoid system, particularly cannabinoid receptor 2 (CB2), is implicated in skin cancer development, progression, and metastasis. Comparing wildtype (WT) to systemic CB2 knockout (CB2) mice, we performed a spontaneous cancer study in one-year old mice, and subsequently used the multi-stage chemical carcinogenesis model, wherein cancer is initiated by 7,12-dimethylbenz[a]anthracene (DMBA) and promoted by 12-O-tetradecanoylphorbol-13-acetate (TPA). We found that aging CB2 mice have an increased incidence of spontaneous cancerous and precancerous skin lesions compared to their WT counterparts. In the DMBA/TPA model, CB2 developed more and larger papillomas, had decreased spontaneous regression of papillomas, and displayed an altered systemic immune profile, including upregulated CD4+ T cells and dendritic cells, compared to WT mice. Immune cell infiltration in the tumor microenvironment was generally low for both genotypes, although a trend of higher myeloid-derived suppressor cells was observed in the CB2 mice. CB2 expression in carcinogen-exposed skin was significantly higher compared to naïve skin in WT mice, suggesting a role of CB2 on keratinocytes. Taken together, our data show that endogenous CB2 activation plays an anti-tumorigenic role in non-melanoma skin carcinogenesis, potentially via an immune-mediated response involving the alteration of T cells and myeloid cells coupled with the modulation of keratinocyte activity.
Topics: Animals; Mice; 9,10-Dimethyl-1,2-benzanthracene; Carcinogenesis; Carcinogens; Papilloma; Receptors, Cannabinoid; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate; Tumor Microenvironment
PubMed: 37175480
DOI: 10.3390/ijms24097773 -
Toxicology Mechanisms and Methods Oct 2020Toxicological studies have identified polycyclic aromatic hydrocarbons (PAH) in human breast milk, smoked and barbequed food, although the largest contribution of PAH...
Toxicological studies have identified polycyclic aromatic hydrocarbons (PAH) in human breast milk, smoked and barbequed food, although the largest contribution of PAH intake into the body are cereals and cereals products. The major effects attributable to PAH appeared to occur in the liver, lungs, the hematopoietic system, and the kidney. Nevertheless, more precise mechanisms by which PAH initiates its pathological features are not fully understood. In the present study, we evaluated levels of myeloperoxidase activity, its association with nitric oxide synthesis (NO), levels of uric acid (UA) in circulating blood and glucose in female rats exposed to environmental toxicants. A higher concentration of hydrogen peroxide activates myeloperoxidase, which acts as a leucocyte attractant, contributing to enhanced iNOS activity. In parallel, uric acid in addition to its pro-inflammatory effects aggravates insulin resistance and hyperglycemia, which worsens the process. Our findings suggest potential intermediate mechanisms involved in the inflammatory effects of PAH, which might give insight for the involvement of environmental toxicants not only in carcinogenesis but also in its association with acute cardiovascular disease and induction of multi-organ damage. The development of iNOS inhibitors might be beneficial in certain inflammatory disorders.
Topics: 9,10-Dimethyl-1,2-benzanthracene; Animals; Biomarkers; Blood Glucose; Environmental Pollutants; Female; Inflammation; Inflammation Mediators; Kidney; Lipid Peroxidation; Liver; Nitric Oxide; Oxidative Stress; Peroxidase; Protein Carbonylation; Rats, Wistar; Uric Acid
PubMed: 32623939
DOI: 10.1080/15376516.2020.1791293 -
Biomedicine & Pharmacotherapy =... Nov 2022Breast cancer prevalence has been globally increasing, therefore, introducing novel interventions in cancer treatment is of a significant importance. The present study...
BACKGROUND
Breast cancer prevalence has been globally increasing, therefore, introducing novel interventions in cancer treatment is of a significant importance. The present study was designed to investigate the anti-cancer effect of Canagliflozin (CNG) in an experimental model of DMBA-induced mammary carcinoma in female rats.
METHODS
18 female rats were divided into three experimental groups: Normal control, DMBA control, DMBA+ CNG treated group. DMBA (7.5 mg/kg) was injected subcutaneously in the mammary cells twice weekly for 4 weeks and CNG (10 mg/kg) was orally administered daily for an additional 3 weeks while DMBA control rats only received the vehicle for 3 weeks. Tumors' weight and volume were measured, BRCA-1 and TAC were quantified in serum samples, mTOR, caspase-1, NFκB, IL-1β, NLRP3, GSDMD and MDA were quantified in tumors' homogenates.
RESULTS
CNG treatment increased the BRCA-1 expression, suppressed mTOR inflammatory pathway, attenuated tumor inflammatory mediators; NLRP3, GSDMD, NFκB, IL-1β, suppressed the oxidative stress and inhibited tumor expression of the proliferation biomarker; Ki67.
CONCLUSION
CNG modulated mTOR-mediated signaling pathway and attenuated pyroptotic, inflammatory pathways, suppressed oxidative stress and eventually inhibited DMBA-induced mammary carcinoma proliferation.
Topics: Rats; Female; Animals; 9,10-Dimethyl-1,2-benzanthracene; Ki-67 Antigen; Canagliflozin; Mammary Neoplasms, Experimental; Rats, Sprague-Dawley; NLR Family, Pyrin Domain-Containing 3 Protein; Signal Transduction; Caspase 1; Carcinoma; TOR Serine-Threonine Kinases; Inflammation Mediators
PubMed: 36115110
DOI: 10.1016/j.biopha.2022.113675