Omega-3 free fatty acids attenuate insulin-promoted breast cancer cell proliferation

Effects of Functional and Nutraceutical Foods in the Context of the Mediterranean Diet in Patients Diagnosed with Breast Cancer

Several studies report that breast cancer survivors (BCS) tend to have a poor diet, as fruit, vegetable, and legume consumption is often reduced, resulting in a decreased intake of nutraceuticals. Moreover, weight gain has been commonly described among BCS during treatment, increasing recurrence rate and mortality. Improving lifestyle and nutrition after the diagnosis of BC may have important benefits on patients' general health and on specific clinical outcomes. The Mediterranean diet (MD), known for its multiple beneficial effects on health, can be considered a nutritional pool comprising several nutraceuticals: bioactive compounds and foods with anti-inflammatory and antioxidant effects. Recent scientific advances have led to the identification of nutraceuticals that could amplify the benefits of the MD and favorably influence gene expression in these patients. Nutraceuticals could have beneficial effects in the postdiagnostic phase of BC, including helping to mitigate the adverse effects of chemotherapy and radiotherapy. Moreover, the MD could be a valid and easy-to-follow option for managing excess weight. The aim of this narrative review is to evaluate the recent scientific literature on the possible beneficial effects of consuming functional and nutraceutical foods in the framework of MD in BCS.

Metformin derivatives - Researchers' friends or foes?

Metformin has been used for ages to treat diabetes mellitus due to its safety profile and low cost. However, metformin has variable pharmacokinetics in patients, and due to its poor oral absorption, the therapeutic doses are relatively high, causing unpleasant gastrointestinal adverse effects. Therefore, novel derivatives of metformin have been synthesized during the past decades. Particularly, after the mid-2000 s, when organic cation transporters were identified as the main metformin carriers, metformin derivatives have been under intensive investigation. Nevertheless, due to the biguanide structure, derivatives of metformin have been challenging to synthesize. Moreover, the mechanisms of metformin's action are not fully understood to date, and since it has multifunctional properties, the interests have switched to re-purposing for other diseases. Indeed, metformin derivatives have been demonstrated in many cases to be more effective than metformin itself and have the potential to be used in different diseases, including several types of cancers and neurodegenerative diseases. On the other hand, the pleiotropic nature of metformin and its derivatives can also create challenges. Not all properties are fit for all diseases. In this review, the history of the development of metformin-like compounds is summarized, and insights into their potential for future drug discovery are discussed.

Nutritional and bioactive oils from salmon (Salmo salar) side streams obtained by Soxhlet and optimized microwave-assisted extraction

The efficiency of the microwave-assisted extraction (MAE) technique on recovering nutritional and bioactive oils from salmon (Salmo salar) side streams was evaluated and compared to Soxhlet extraction. The response surface methodology (RSM) coupled with a central composite rotatable design was used to optimize time, microwave power, and solid/liquid ratio of the MAE process in terms of oil yield. The optimal MAE conditions were 14.6 min, 291.9 W, 80.1 g/L for backbones, 10.8 min, 50.0 W, 80.0 g/L for heads, and 14.3 min, 960.6 W, 99.5 g/L for viscera, which resulted in a recovery of 69% of the total lipid content for backbones and heads and 92% for viscera. The oils obtained under optimal MAE conditions showed a healthy lipid profile as well as cytotoxic, antioxidant, anti-inflammatory, or antimicrobial properties. These results highlight that oils from underutilized salmon by-products could be exploited by different industrial sectors under the circular economy approach.

Oleic Acid and Insulin as Key Characteristics of T2D Promote Colorectal Cancer Deterioration in Xenograft Mice Revealed by Functional Metabolomics

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers with high mortality worldwide. Type 2 diabetes mellitus (T2D), known as a risk factor of CRC, can promote the deterioration of CRC, but the underlying mechanism is elusive. In this study, we aimed to reveal the relationship between CRC and T2D from the perspective of small-molecule metabolism. First, a list of common dysregulated metabolites in CRC and T2D was obtained by retrieving existing metabolomics publications. Among these metabolites, oleic acid (OA) was found to be able to promote the proliferation and migration of colon carcinoma cell HCT116. Further experiments proved that insulin could significantly strengthen this promotion and showed a synergistic effect with OA. Mechanism study found that OA and insulin acted synergistically through the extracellular signal-regulated kinase (ERK)1/2/c-Myc/cyclin D1 pathway. In addition, the combination of ERK1/2 inhibitor SCH772984 and cyclin-dependent kinase (CDK)4/6 inhibitor palbociclib showed a remarkable inhibitory effect on tumor growth in vivo. Taken together, the current study found that OA plays an important role in CRC development by using a functional metabolomics approach. More importantly, insulin and OA were confirmed to synergistically promote the deterioration of CRC in vitro and in vivo via ERK1/2/c-Myc/cyclin D1 pathway. Our findings may shed light on CRC treatment among the T2D population.

Insulin and Metformin Control Cell Proliferation by Regulating TDG-Mediated DNA Demethylation in Liver and Breast Cancer Cells

Type 2 diabetes mellitus (T2DM) is a frequent comorbidity of cancer. Hyperinsulinemia secondary to T2DM promotes cancer progression, whereas antidiabetic agents, such as metformin, have anticancer effects. However, the detailed mechanism for insulin and metformin-regulated cancer cell proliferation remains unclear. This study identified a mechanism by which insulin upregulated the expression of c-Myc, sterol regulatory element-binding protein 1 (SREBP1), and acetyl-coenzyme A (CoA) carboxylase 1 (ACC1), which are important regulators of lipogenesis and cell proliferation. Thymine DNA glycosylase (TDG), a DNA demethylase, was transactivated by c-Myc upon insulin treatment, thereby decreasing 5-carboxylcytosine (5caC) abundance in the SREBP1 promoter. On the other hand, metformin-activated AMP-activated protein kinase (AMPK) increased DNA methyltransferase 3A (DNMT3A) activity to increase 5-methylcytosine (5mC) abundance in the TDG promoter. This resulted in decreased TDG expression and enhanced 5caC abundance in the SREBP1 promoter. These findings demonstrate that c-Myc activates, whereas AMPK inhibits, TDG-mediated DNA demethylation of the SREBP1 promoter in insulin-promoted and metformin-suppressed cancer progression, respectively. This study indicates that TDG is an epigenetic-based therapeutic target for cancers associated with T2DM.

Growth-Inhibitory Effect of Chitosan-Coated Liposomes Encapsulating Curcumin on MCF-7 Breast Cancer Cells

Current anticancer drugs exhibit limited efficacy and initiate severe side effects. As such, identifying bioactive anticancer agents that can surpass these limitations is a necessity. One such agent, curcumin, is a polyphenolic compound derived from turmeric, and has been widely investigated for its potential anti-inflammatory and anticancer effects over the last 40 years. However, the poor bioavailability of curcumin, caused by its low absorption, limits its clinical use. In order to solve this issue, in this study, curcumin was encapsulated in chitosan-coated nanoliposomes derived from three natural lecithin sources. Liposomal formulations were all in the nanometric scale (around 120 nm) and negatively charged (around -40 mV). Among the three lecithins, salmon lecithin presented the highest growth-inhibitory effect on MCF-7 cells (two times lower growth than the control group for 12 µM of curcumin and four times lower for 20 µM of curcumin). The soya and rapeseed lecithins showed a similar growth-inhibitory effect on the tumor cells. Moreover, coating nanoliposomes with chitosan enabled a higher loading efficiency of curcumin (88% for coated liposomes compared to 65% for the non-coated liposomes) and a stronger growth-inhibitory effect on MCF-7 breast cancer cells.

Effects of ‎Bioactive ‎Marine-Derived ‎Liposomes on ‎Two ‎Human ‎Breast Cancer ‎‎Cell Lines

Breast cancer is the leading cause of death from cancer among women. Higher consumption of dietary marine n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) is associated with a lower risk of breast cancer. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are two n-3 LC-PUFAs found in fish and exert anticancer effects. In this study, natural marine-derived lecithin that is rich in various polyunsaturated fatty acids (PUFAs) was extracted from salmon heads and transformed into nanoliposomes. These nanoliposomes were characterized and cultured with two breast cancer lines (MCF-7 and MDA-MB-231). The nanoliposomes decreased the proliferation and the stiffness of both cancer cell types. These results suggest that marine-derived lecithin possesses anticancer properties, which may have an impact on developing new liposomal delivery strategies for breast cancer treatment.

Anticancer activities of fatty acids and their heterocyclic derivatives

Traditional chemotherapy relies on the premise that rapidly proliferating cancer cells are more likely to be killed by a cytotoxic agent, but in reality, the long-standing problem of chemotherapy is the lack of tumor-specific treatments. Apart from the impact on tumor cells, the drugs' major limitation is their severe adverse side effects on normal cells and tissues. Nutritional and epidemiological studies have indicated that cancer progression is correlated with the consumption of fatty acids, but the exact mechanisms still remain unknown. In the first part of our review, we discussed the beneficial effects of free fatty acids (saturated and unsaturated) on the progress of carcinogenesis in different tumor cell lines. We presented various mechanisms proposed in the literature, which explain the possible impact on the cells metabolism. The second part describes modifications of different fatty acids with existing anticancer drugs and heterocyclic moieties by condensation reactions. Such conjugations increased the tissue selectivity and made chemotherapy potentially more effective and less toxic in in vivo and in vitro studies. This fatty acid modifications, which change the activity of compounds, their uptake selectivity and alter drug delivery methods, may be the key to unlocking true medical potential of fatty acids.

Docosahexaenoic Acid Inhibits PTP1B Phosphatase and the Viability of MCF-7 Breast Cancer Cells

BACKGROUND

Docosahexaenoic acid (DHA) is an essential polyunsaturated fatty acid compound present in deep water fishes and dietary supplements, with a wide spectrum of potential health benefits, ranging from neurological to anti-inflammatory.

METHODS

Due to the fact that DHA is considered a breast cancer risk reducer, we examined the impact of DHA on MCF-7 breast cancer cells' viability and its inhibitory properties on protein tyrosine phosphatase 1B (PTP1B), a pro-oncogenic phosphatase.

RESULTS

We found that DHA is able to lower both the enzymatic activity of PTP1B phosphatase and the viability of MCF-7 breast cancer cells. We showed that unsaturated DHA possesses a significantly higher inhibitory activity toward PTP1B in comparison to similar fatty acids. We also performed a computational analysis of DHA binding to PTP1B and discovered that it is able to bind to an allosteric binding site.

CONCLUSIONS

Utilizing both a recombinant enzyme and cellular models, we demonstrated that DHA can be considered a potential pharmacological agent for the prevention of breast cancer.

ω-3 Long Chain Polyunsaturated Fatty Acids as Sensitizing Agents and Multidrug Resistance Revertants in Cancer Therapy

Chemotherapy efficacy is strictly limited by the resistance of cancer cells. The ω-3 long chain polyunsaturated fatty acids (ω-3 LCPUFAs) are considered chemosensitizing agents and revertants of multidrug resistance by pleiotropic, but not still well elucidated, mechanisms. Nowadays, it is accepted that alteration in gene expression, modulation of cellular proliferation and differentiation, induction of apoptosis, generation of reactive oxygen species, and lipid peroxidation are involved in ω-3 LCPUFA chemosensitizing effects. A crucial mechanism in the control of cell drug uptake and efflux is related to ω-3 LCPUFA influence on membrane lipid composition. The incorporation of docosahexaenoic acid in the lipid rafts produces significant changes in their physical-chemical properties affecting content and functions of transmembrane proteins, such as growth factors, receptors and ATP-binding cassette transporters. Of note, ω-3 LCPUFAs often alter the lipid compositions more in chemoresistant cells than in chemosensitive cells, suggesting a potential adjuvant role in the treatment of drug resistant cancers.