New Analogs of Polyamine Toxins from Spiders and Wasps: Liquid Phase Fragment Synthesis and Evaluation of Antiproliferative Activity

Polyamine toxins (PATs) are conjugates of polyamines (PAs) with lipophilic carboxylic acids, which have been recently shown to present antiproliferative activity. Ten analogs of the spider PATs Agel 416, HO-416b, and JSTX-3 and the wasp PAT PhTX-433 were synthesized with changes in the lipophilic head group and/or the PA chain, and their antiproliferative activity was evaluated on MCF-7 and MDA-MB-231 breast cancer cells, using Agel 416 and HO-416b as reference compounds. All five analogs of PhTX-433 were of very low activity on both cell lines, whereas the two analogs of JSTX-3 were highly active only on the MCF-7 cell line with IC50 values of 2.63–2.81 μΜ. Of the remaining three Agel 416 or HO-416b analogs, only the one with the spermidine chain was highly active on both cells with IC50 values of 3.15–12.6 μM. The two most potent compounds in this series, Agel 416 and HO-416b, with IC50 values of 0.09–3.98 μΜ for both cell lines, were found to have a very weak cytotoxic effect on the MCF-12A normal breast cells. The present study points out that the structure of both the head group and the PA chain determine the strength of the antiproliferative activity of PATs and their selectivity towards different cells.

CRISPR screens identify gene targets and drug repositioning opportunities at breast cancer risk loci

Genome-wide association studies (GWAS) have identified >200 loci associated with breast cancer (BC) risk. The majority of candidate causal variants (CCVs) are in non-coding regions and likely modulate cancer risk by regulating gene expression. However, pinpointing the exact target of the association and identifying the phenotype it mediates is a major challenge in the interpretation and translation of GWAS. Here, we used pooled CRISPR activation and suppression screens to evaluate predicted GWAS target genes, and to define the cancer phenotypes they mediate. We measured proliferation in 2D, 3D, and in immune-deficient mice, as well as the effect on DNA repair. We performed 60 CRISPR screens and identified 21 genes predicted with high confidence to be GWAS targets that drive a cancer phenotype by driving a proliferation or DNA damage response in breast cells. We validated the regulation of a subset of these genes by BC-risk variants, and show the utility of expression profiling for drug repurposing. We provide a platform for identifying gene targets of risk variants, and present a blueprint of interventions for BC risk reduction and treatment.

VITAMIN D3 IN BREAST CANCER PREVENTION: MYTH OR REALITY (literature review)

В 2018 году в Республике Казахстан было зарегистрировано 4648 новых случая рака молочной железы (РМЖ). Результаты: О взаимосвязи уровня витамина Д3 и риска развития РМЖ свидетельствуют результаты достаточного числа исследований. Женщины с высоким содержанием витамина Д в рационе питания имеют меньший риск развития РМЖ. Положительное противоопухолевое действие витамина Д3 связано с двумя основными механизмами: антипролиферативным эффектом, ингибирующим ростом клеток путем подавления сигналов, стимулирующих рост рецепторов, которые имеются в ткани молочной железы, и проапоптотическим эффектом, способствующим естественной гибели клеток молочной железы. Заключение: Накопленные к настоящему времени данные о роли витамина Д3 в организме человека, взаимосвязи его уровня с развитием и течением онкологической патологии позволяют предположить, что коррекция недостаточного уровня витамина Д3 может быть перспективным направлением в профилактике и комплексном лечении онкологических заболеваний. Introduction: In 2018, 4648 new cases of breast cancer (BC) were registered in the Republic of Kazakhstan. Results: The relationship between the level of vitamin D3 and the risk of developing breast cancer is evidenced by the results of a sufficient number of studies. Women with a high vitamin D diet have a lower risk of developing breast cancer. The positive antitumor effect of vitamin D3 is associated with two main mechanisms: the antiproliferative effect, which inhibits cell growth by suppressing signals that stimulate the growth of receptors present in the breast tissue, and the proapoptotic effect, which promotes the natural death of breast cells. Conclusion: The data accumulated to date on the role of vitamin D3 in the human body, the relationship of its level with the development and course of oncological pathology suggests that the correction of insufficient levels of vitamin D3 may be a promising direction in the prevention and complex treatment of cancer.

The Secretome of Human Neonatal Mesenchymal Stem Cells Modulates Doxorubicin-Induced Cytotoxicity: Impact in Non-Tumor Cells

Doxorubicin (Dox) is one of the most widely used treatments for breast cancer, although limited by the well-documented cardiotoxicity and other off-target effects. Mesenchymal stem cell (MSC) secretome has shown immunomodulatory and regenerative properties, further potentiated under 3D conditions. This work aimed to uncover the effect of the MSC-derived secretome from 3D (CM3D) or 2D (CM2D) cultures, in human malignant breast cells (MDA-MB-231), non-tumor breast epithelial cells (MCF10A) and differentiated AC16 cardiomyocytes, co-treated with Dox. A comprehensive proteomic analysis of CM3D/CM2D was also performed to unravel the underlying mechanism. CM3D/CM2D co-incubation with Dox revealed no significant differences in MDA-MB-231 viability when compared to Dox alone, whereas MCF10A and AC16 viability was consistently improved in Dox+CM3D-treated cells. Moreover, neither CM2D nor CM3D affected Dox anti-migratory and anti-invasive effects in MDA-MB-231. Notably, Ge-LC-MS/MS proteomic analysis revealed that CM3D displayed protective features that might be linked to the regulation of cell proliferation (CAPN1, CST1, LAMC2, RANBP3), migration (CCN3, MMP8, PDCD5), invasion (TIMP1/2), oxidative stress (COX6B1, AIFM1, CD9, GSR) and inflammation (CCN3, ANXA5, CDH13, GDF15). Overall, CM3D decreased Dox-induced cytotoxicity in non-tumor cells, without compromising Dox chemotherapeutic profile in malignant cells, suggesting its potential use as a chemotherapy adjuvant to reduce off-target side effects.

Peran Matriks Metalloproteinase 8 Pada Metastasis Sel Kanker Payudara

MMP-8 merupakan protease yang diproduksi oleh neutrofil dan berperan dalam degradasi kolagen yang terdapat pada jaringan ikat pada mamalia. Pada manusia, protein MMP-8 disandi oleh gen MMP-8. Pada umumnya, MMP disekresi dalam bentuk proprotein yang diaktifkan ketika dipecah oleh proteinase ekstraseluler. Peningkatan Ekspresi MMP-8 berlebih pada penderita kanker payudara di fase yang berbeda, peningkatan ekspresi MMP-8 tidak ditemukan pada sel payudara normal. MMP-8 memiliki substrat yang berbeda dengan MMP-2 dan MMP-9 yang berperan langsung dalam penyebab metastasis sel kanker payudara ke organ lain. Peran MMP-8 terhadap kanker payudara telah dilaporkan oleh penelitian sebelumnya bahwa MMP-8 mampu memicu metastasis kanker payudara melalui peningkatan sitokin proinflamasi yaitu IL-6 dan IL-8. IL-6 dan IL-8 menginduksi metastasis melalui jalur persinyalan JAK/STAT3 yang akan mengaktifkan snail/slug/twist yang akan menekan ekspresi E-cadherin, selain itu IL-6 dan IL-8 memicu sintesis VEGF sehingga mengakibatkan pembentukan pembuluh darah baru. MMP-8 is a protease produced by neutrophils and plays a role in the degradation of collagen found in connective tissue in mammals. In humans, the MMP-8 protein is encoded by the MMP-8 gene. In general, MMPs are secreted in the form of proproteins that are activated when cleaved by extracellular proteinases. MMP-8 Ekspression increased in breast cancer patients at different stages, but it is not happenin normal breast cells. MMP-8 has a different substrate with MMP-2 and MMP-9 which play a direct role in causing breast cancer cell metastasis to other organs. The role of MMP-8 in breast cancer has been reported by previous studies that MMP-8 is able to trigger breast cancer metastasis through an increase in proinflammatory cytokines,such as IL-6 and IL-8. IL-6 and IL-8 induce metastasis through the JAK/STAT3 signaling pathway which will activate snail/slug/twist which will suppress E-cadherin expression, in addition IL-6 and IL-8 trigger VEGF synthesis, resulting in the formation of new blood vessels.

Endotoxin Triggers Tumor Initiation Events in Nontumorigenic Breast Epithelial Cells and Enhances Invasion-Related Phenotype in Pretumorigenic and Tumorigenic Breast Epithelial Cells

Inflammation is associated with the development of several cancers, including breast cancer. However, the molecular mechanisms driving breast cancer initiation or enhancement by inflammation are yet to be deciphered. Hence, we opted to investigate the role of inflammation in initiating and enhancing tumor-like phenotypes in nontumorigenic, pretumorigenic, and tumorigenic breast epithelial cells. Noncytotoxic endotoxin (ET) concentrations capable of inducing an inflammatory phenotype were determined for the different cell lines. Results showed that short-term ET exposure upregulated matrix metalloproteinase-9 (MMP-9) activity in nontumorigenic mammary epithelial cells of mouse (SCp2) and human origins (HMT-3522 S1; S1) and upregulated inflammatory mediators including nitric oxide (NO) and interleukin 1-β in tumorigenic human breast cells (MDA-MB-231), all in a dose-dependent manner. Long-term ET treatment, but not short-term, triggered the migration of SCp2 cells, and proliferation and migration of tumorigenic human breast cells MCF-7 and MDA-MB-231. Both short- and long-term ET exposures preferentially enhanced the invasion of pretumorigenic S1-connexin 43 knockout (Cx43-KO S1) cells compared to their nontumorigenic S1 counterparts. Moreover, both ET exposures disrupted lumen formation and apicolateral distribution of β-catenin in 3D cultures of S1 cells. In conclusion, ET treatment at concentrations that elicited inflammatory phenotype triggered tumor initiation events in nontumorigenic and pretumorigenic breast cells, and increased tumorigenicity of breast cancer cells. Our findings highlight the role of inflammation in enhancing migration, invasion, and loss of normal 3D morphology and suggest that such inflammatory insults can “add injury” to pretumorigenic and tumorigenic breast epithelial cells.

Functionalized Poly(N-isopropylacrylamide)-Based Microgels in Tumor Targeting and Drug Delivery

Over the past several decades, the development of engineered small particles as targeted and drug delivery systems (TDDS) has received great attention thanks to the possibility to overcome the limitations of classical cancer chemotherapy, including targeting incapability, nonspecific action and, consequently, systemic toxicity. Thus, this research aims at using a novel design of Poly(N-isopropylacrylamide) p(NIPAM)-based microgels to specifically target cancer cells and avoid the healthy ones, which is expected to decrease or eliminate the side effects of chemotherapeutic drugs. Smart NIPAM-based microgels were functionalized with acrylic acid and coupled to folic acid (FA), targeting the folate receptors overexpressed by cancer cells and to the chemotherapeutic drug doxorubicin (Dox). The successful conjugation of FA and Dox was demonstrated by dynamic light scattering (DLS), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), UV-VIS analysis, and differential scanning calorimetry (DSC). Furthermore, viability assay performed on cancer and healthy breast cells, suggested the microgels’ biocompatibility and the cytotoxic effect of the conjugated drug. On the other hand, the specific tumor targeting of synthetized microgels was demonstrated by a co-cultured (healthy and cancer cells) assay monitored using confocal microscopy and flow cytometry. Results suggest successful targeting of cancer cells and drug release. These data support the use of pNIPAM-based microgels as good candidates as TDDS.