Protein deregulation associated with breast cancer metastasis

In vivo evaluation of mebendazole and Ran GTPase inhibition in breast cancer model system

Aim: To investigate the therapeutic potential of mebendazole (MBZ)-loaded nanostructured lipid carriers (NLCs). Methodology: NLC-MBZ was prepared and characterized to evaluate the in vitro and in vivo anticancer effects and the inhibitory effect on RanGTP and its potential as an antimetastatic treatment in vivo. Results: NLC-MBZ exhibited a size and charge of 155 ± 20 nm and -27 ± 0.5 mV, respectively, with 90.7% encapsulation. Free MBZ and NLC-MBZ had a 50% inhibitory concentration of 610 and 305 nM, respectively, against MDA-MB-231 cell lines. NLC-MBZ decreased tumor size, suppressed tumor lung metastases, and lowered the expression of CDC25A, SKP2, RbX1 and Cullin1 while boosting the Rb proteins. Conclusion: NLC-MBZ displayed antiangiogenic potential and resulted in a reduced rate of lung metastasis in vivo.

Breast carcinogenesis induced by organophosphorous pesticides

Breast cancer is a major health threat to women worldwide and the leading cause of cancer-related death. The use of organophosphorous pesticides has increased in agricultural environments and urban settings, and there is evidence that estrogen may increase breast cancer risk in women. The mammary gland is an excellent model for examining its susceptibility to different carcinogenic agents due to its high cell proliferation capabilities associated with the topography of the mammary parenchyma and specific stages of gland development. Several experimental cellular models are presented here, in which the animals were exposed to chemical compounds such as pesticides, and endogenous substances such as estrogens that exert a significant effect on normal breast cell processes at different levels. Such models were developed by the effect of malathion, parathion, and eserine, influenced by estrogen demonstrating features of cancer initiation in vivo as tumor formation in rodents; and in vitro in the immortalized normal breast cell line MCF-10F, that when transformed showed signs of carcinogenesis such as increased cell proliferation, anchorage independence, invasive capabilities, modulation of receptors and genomic instability. The role of acetylcholine was also demonstrated in the MCF-10F, suggesting a role not only as a neurotransmitter but also with other functions, such as induction of cell proliferation, playing an important role in cancer. Of note, this is a unique experimental approach that identifies mechanistic signs that link organophosphorous pesticides with breast carcinogenesis.

Dopamine D1 Receptor in Cancer

Simple Summary

Circulating hormones and their specific receptors play a significant role in the development and progression of various cancers. This review aimed to summarize current knowledge about the dopamine D1 receptor’s biological role in different cancers, including breast cancer, central nervous system tumors, lymphoproliferative disorders, and other neoplasms. Treatment with dopamine D1 receptor agonists was proven to exert a major anti-cancer effect in many preclinical models. We highlight this receptor’s potential as a target for the adjunct therapy of tumors and discuss possibilities and necessities for further research in this area.

Abstract

Dopamine is a biologically active compound belonging to catecholamines. It plays its roles in the human body, acting both as a circulating hormone and neurotransmitter. It acts through G-protein-coupled receptors divided into two subgroups: D1-like receptors (D1R and D5R) and D2-like receptors (D2R, D3R, D4R). Physiologically, dopamine receptors are involved in central nervous system functions: motivation or cognition, and peripheral actions such as blood pressure and immune response modulation. Increasing evidence indicates that the dopamine D1 receptor may play a significant role in developing different human neoplasms. This receptor’s value was presented in the context of regulating various signaling pathways important in tumor development, including neoplastic cell proliferation, apoptosis, autophagy, migration, invasiveness, or the enrichment of cancer stem cells population. Recent studies proved that its activation by selective or non-selective agonists is associated with significant tumor growth suppression, metastases prevention, and tumor microvasculature maturation. It may also exert a synergistic anti-cancer effect when combined with tyrosine kinase inhibitors or temozolomide. This review provides a comprehensive insight into the heterogeneity of dopamine D1 receptor molecular roles and signaling pathways in human neoplasm development and discusses possible perspectives of its therapeutic targeting as an adjunct anti-cancer strategy of treatment. We highlight the priorities for further directions in this research area.

Extracellular Matrix Derived from High Metastatic Human Breast Cancer Triggers Epithelial-Mesenchymal Transition in Epithelial Breast Cancer Cells through αvβ3 Integrin

Alterations in the composition and architecture of the extracellular matrix (ECM) can influence cancer growth and dissemination. During epithelial-mesenchymal transition (EMT), epithelial cells assume a mesenchymal cell phenotype, changing their adhesion profiles from cell-cell contacts to cell-matrix interactions, contributing to metastasis. Breast cancer cells present at different stages of differentiation, producing distinct ECMs in the same tumor mass. However, the contribution of ECM derived from metastatic tumor cells to EMT is unclear. Here, we showed the mechanisms involved in the interaction of MCF-7, a low-metastatic, epithelial breast cancer cell line, with the ECM produced by a high metastatic breast tumor cell, MDA-MB-231 (MDA-ECM). MDA-ECM induced morphological changes in MCF-7 cells, decreased the levels of E-cadherin, up-regulated mesenchymal markers, and augmented cell migration. These changes were accompanied by the activation of integrin-associated signaling, with increased phosphorylation of FAK, ERK, and AKT and activation canonical TGF-β receptor signaling, enhancing phosphorylation of SMAD2 and SMAD4 nuclear translocation in MCF-7 cells. Treatment with Kistrin (Kr), a specific ligand of integrin αvβ3 EMT induced by MDA-ECM, inhibited TGF-β receptor signaling in treated MCF-7 cells. Our results revealed that after interaction with the ECM produced by a high metastatic breast cancer cell, MCF-7 cells lost their characteristic epithelial phenotype undergoing EMT, an effect modulated by integrin signaling in crosstalk with TGF-β receptor signaling pathway. The data evidenced novel potential targets for antimetastatic breast cancer therapies.

Prognostic phenotypic classification for canine mammary tumors

Mammary neoplasms are a heterogeneous form of disease, and in order to determine its course and biological features with more accuracy, investigations based on tumor phenotypes are required. The aim of the present study was to propose and validate a phenotypic classification for canine mammary tumors and to assess any association between clinicopathological characteristics, survival and prognosis. For the immunohistochemistry analysis, the primary antibodies against estrogen receptor-α, progesterone receptor, human epidermal growth factor receptor 2 (HER-2)/neu and E-cadherin were used. A total of 110 canine mammary tumors were investigated; 42 tumors were classified as luminal A, 41 as luminal B, 17 as triple-negative and 10 as HER-2-positive. The luminal A and B phenotypes were associated with improved prognosis, whereas HER-2positive and triple-negative tumors were more aggressive, and exhibited a significant association with the occurrence of metastasis, a worse Tumor-Node-Metastasis classification and shorter survival time (P<0.05). In addition, there were different levels of E-cadherin expression intensity observed among the four tumor profiles investigated. Luminal A and B phenotypes presented an upregulation of E-cadherin compared with the HER-2 positive and triple-negative phenotypes (P<0.05). From the results of the present study, the proposed immunohistochemical panel and phenotypic classification techniques could be useful diagnostic tools with a good technical applicability in veterinary oncology. The analysis of E-cadherin expression in the panel of tumor markers allowed a more accurate classification for determining the biological features of the mammary tumor.

Apoptotic and antimetastatic activities of betulin isolated from Quercus incana against non-small cell lung cancer cells

Background

Globally, the prevalence and mortality rates of lung cancer have been escalated with the increasing trend of tobacco smoking. The toxicity and irresponsive nature of the available drugs for lung cancer treatment demands an alternative approach.

Methods

In this study, four known compounds namely, cirsimaritin (4′,5, -dihydroxy-6,7-di-methoxyflavone) (1), eupatorin (5,3′-dihydroxy-6,7,4′-trimethoxyflavone) (2), betulin (Lup-20 (29)-ene-3, 28-diol) (3), and β-amyrin acetate (12-Oleanen-3yl acetate) (4) have been isolated from the leaves extract of Quercus incana. Preliminary screening of these natural compounds (1–4) was performed against non-small cell lung carcinoma (NCI-H460) and normal mouse fibroblast (NIH-3T3) cell lines.

Results

The compounds were found to be antiproliferative against cancer cells with wide therapeutic index in comparison to the normal cells. Effects of betulin (3) on cell migration, invasion, apoptosis, and expression of important apoptosis- and metastasis-related markers were observed at different concentrations. The results showed significant dose-dependent induction of apoptosis after the treatment with betulin (3) followed by increased expression of the caspases family (ie, caspase-3, -6, and -9), proapoptotic genes (BAX and BAK), and inhibiting anti-apoptotic genes (BCL-2L1 and p53). Furthermore, wound healing and transwell invasion assays suggested that betulin (3) could also regulate metastasis by inhibiting MMP-2/-9. Osteopontin, a central regulator of apoptosis and metastasis was also inhibited in a dose-dependent manner.

Conclusion

The present findings suggest that betulin (3) can be an attractive chemotherapeutic target for treating resistant lung cancers.

Overexpression of the ATPase Inhibitory Factor 1 Favors a Non-metastatic Phenotype in Breast Cancer

Partial suppression of mitochondrial oxidative phosphorylation and the concurrent activation of aerobic glycolysis is a hallmark of proliferating cancer cells. Overexpression of the ATPase inhibitory factor 1 (IF1), an in vivo inhibitor of the mitochondrial ATP synthase, is observed in most prevalent human carcinomas favoring metabolic rewiring to an enhanced glycolysis and cancer progression. Consistently, a high expression of IF1 in hepatocarcinomas and in carcinomas of the lung, bladder, and stomach and in gliomas is a biomarker of bad patient prognosis. In contrast to these findings, we have previously reported that a high expression level of IF1 in breast carcinomas is indicative of less chance to develop metastatic disease. This finding is especially relevant in the bad prognosis group of patients bearing triple-negative breast carcinomas. To investigate the molecular mechanisms that underlie the differential behavior of IF1 in breast cancer progression, we have developed the triple-negative BT549 breast cancer cell line that overexpresses IF1 stably. When compared to controls, IF1-cells partially shut down respiration and enhance aerobic glycolysis. Transcriptomic analysis suggested that migration and invasion were specifically inhibited in IF1-overexpressing breast cancer cells. Analysis of gene expression by qPCR and western blotting indicate that IF1 overexpression supports the maintenance of components of the extracellular matrix (ECM) and E-cadherin concurrently with the downregulation of components and signaling pathways involved in epithelial to mesenchymal transition. The overexpression of IF1 in breast cancer cells has no effect in the rates of cellular proliferation and in the cell death response to staurosporine and hydrogen peroxide. However, the overexpression of IF1 significantly diminishes the ability of the cells to grow in soft agar and to migrate and invade when compared to control cells. Overall, the results indicate that IF1 overexpression despite favoring a metabolic phenotype prone to cancer progression in the specific case of breast cancer cells also promotes the maintenance of the ECM impeding metastatic disease. These findings hence provide a mechanistic explanation to the better prognosis of breast cancer patients bearing tumors with high expression level of IF1.