The Sources of Essential Fatty Acids for Allergic and Cancer Patients; a Connection with Insight into Mammalian Target of Rapamycin: A Narrative Review

Molecular Mechanisms Associated with the Inhibitory Role of Long Chain n-3 PUFA in Colorectal Cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related death in the world. Multiple evidence suggests that there is an association between excess fat consumption and the risk of CRC. The long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are essential for human health, and both in vitro and in vivo studies have shown that these fatty acids can prevent CRC development through various molecular mechanisms. These include the modulation of arachidonic acid (AA) derived prostaglandin synthesis, alteration of growth signaling pathways, arrest of the cell cycle, induction of cell apoptosis, suppression of angiogenesis and modulation of inflammatory response. Human clinical studies found that LC n-3 PUFA combined with chemotherapeutic agents can improve the efficacy of treatment and reduce the dosage of chemotherapy and associated side effects. In this review, we discuss comprehensively the anti-cancer effects of LC n-3 PUFA on CRC, with a main focus on the underlying molecular mechanisms.

Carboplatin and epigallocatechin-3-gallate synergistically induce cytotoxic effects in esophageal cancer cells

Background and purpose:

We aimed at evaluating the effects of combinatorial treatments with carboplatin and epigallocatechin-3-gallate (EGCG) on the KYSE-30 esophageal cancer (EC) cell line and elucidate the underlying mechanisms.

Experimental approach:

EC cells were harvested and exposed to increasing concentrations of carboplatin and EGCG to construct a dose-response plot. Cell inhibitory effects were assessed by the MTT method and apoptosis-related gene expression levels (caspases 8 and 9) and Bcl-2 mRNA were detected using real-time polymerase chain reaction. The lactate levels in the various treated cases were analyzed using the colorimetric assay kit. In addition, total antioxidant capacity was measured.

Findings/Results:

The results indicated that, following treatments with carboplatin in IC₂₀, IC₂₅, and IC₁₀ concentrations when combined with EGCG in similar concentrations, synergistically decreased cell viability versus single treatments of both agents. Also, in combined treatments at IC₂₀ and IC₂₅ of both agents the gene expression ratio of caspases 8 and 9 upregulated significantly compared to monotherapies (P < 0.05). Bcl-2 gene expression ratios were decreased in double agents treated cells versus monotherapies. Following treatment of KYSE-30 cells with carboplatin and EGCG in double combinations, lactate levels were significantly decreased compared with the untreated cells and single treatments (P < 0.05). Also, in IC₂₅, IC₂₀, and IC₁₀ concentrations of both agents the total antioxidant capacity levels were decreased versus monotherapies and untreated cells.

Conclusion and implications:

The presented study determined that treatment with carboplatin and EGCG was capable of promoting cytotoxicity in EC cells and inhibits the cancer progress. Combined treatments with low concentrations of carboplatin and EGCG may promote apoptosis induction and inhibit cell growth. These results confirmed the anticancer effects of carboplatin and EGCG and providing a base for additional use of EGCG to the EC treatment.

Hsp90 Inhibitor; NVP-AUY922 in Combination with Doxorubicin Induces Apoptosis and Downregulates VEGF in MCF-7 Breast Cancer Cell Line

Objective:

Breast cancer is one of the most prevalent malignancies and leading causes of females’ mortality worldwide. Because of resistance to various treatment options, new treatments based on molecular targeting has introduced as noticeable strategies in cancer treatment. In this regard, heat shock protein 90 (Hsp90) inhibitors are proposed as effective anticancer drugs. The goal of the study was to utilize a combination of the doxorubicin (DOX) and NVP-AUY 922 on the MCF-7 breast cancer model to investigate the possible cytotoxic mechanisms.

Methods:

MCF-7 breast cancer cell line was prepared and treated with various concentrations of DOX and NVP-AUY922 in single-drug treatments. We investigated the growth-inhibitory pattern by MTT assay after continuous exposure to NVP-AUY922 and DOX in order to determine dose-response. Then the combinatorial effects were evaluated in concentrations of 0.5 × IC₅₀, 0.2 × IC₅₀, 1 × IC₅₀ and, 2 × IC₅₀ of each drugs. Based on MTT results of double combinations, low effective doses were selected for Real-time PCR [caspase3 and vascular endothelial growth factor (VEGF)] and caspase 3 enzyme activity.

Results:

A dose-dependent inhibitory effects were presented with increasing the doses of both drugs in single treatments. The upregulation of caspase 3 and downregulation of VEGF mRNA were observed in double combinations of NVP-AUY922 and DOX versus single treatments. Also, in these combinations in low doses of examined drugs (0.5 × IC₅₀, 0.2 × IC₅₀), higher caspase 3 activity were presented in comparison to single treatments (p<0.05).

Conclusions:

Our findings indicate an effective action of NVP-AUY922 in combined with DOX in this cell line. These results can predict the treatment outcome in this model.

ΜicroRNA‑421 participates in vitiligo development through regulating human melanocyte survival by targeting receptor‑interacting serine/threonine kinase 1

Vitiligo is a common localized or generalized skin pigmentation disorder. Endoplasmic reticulum (ER) stress may be implicated in the development of vitiligo. microRNA-421 (miR-421) has been reported to be dysregulated in various human tumors. However, there is no report to date on the role of miR-421 in vitiligo development. The present study demonstrated that 3 µM tunicamycin (TM) increased the expression of the ER stress-related proteins protein kinase RNA-like endoplasmic reticulum kinase (PERK), α subunit of eukaryotic translation initiation factor 2 (eIF2α) and C/EBP homologous protein (CHOP) in human primary epidermal melanocytes. Moreover, TM suppressed melanocyte viability and induced apoptosis. Reverse transcription-quantitative PCR analysis demonstrated that TM promoted miR-421 expression in human melanocytes. Next, TargetScan and dual luciferase reporter gene assay indicated that receptor-interacting serine/threonine kinase 1 (RIPK1) was a direct target of miR-421. RIPK1 expression was significantly downregulated in TM-induced human melanocytes. Subsequently, the effect of miR-421 downregulation on the damage of human melanocytes induced by ER stress was investigated. Human melanocytes were transfected with inhibitor control, miR-421 inhibitor, miR-421 inhibitor + control-short hairpin (sh)RNA, or miR-421 inhibitor + RIPK1-shRNA for 24 h and then treated with TM (3 µM) for 48 h. TM was found to upregulate PERK, eIF2α and CHOP protein expression in human melanocytes, which was reduced by an miR-421 inhibitor. In addition, the miR-421 inhibitor increased viability and reduced apoptosis in TM-treated melanocytes. Furthermore, all these effects of the miR-421 inhibitor on TM-induced human melanocytes were reversed by RIPK1-shRNA. Further analyses revealed that the miR-421 inhibitor activated the phosphoinositide 3 kinase/protein kinase B/mammalian target of rapamycin signaling pathway in TM-induced human melanocytes. These data collectively suggest that miR-421 may serve as a new treatment target in vitiligo development.

Association of Delta-6-Desaturase Expression with Aggressiveness of Cancer, Diabetes Mellitus, and Multiple Sclerosis: A Narrative Review

Background: The phosphatidylinositol 3-kinase/ protein kinase B /mammalian target of rapamycin (PI3K/Akt/ mTOR) signaling regulates multiple cellular processes and organizes cell proliferation, survival, and differentiation with the available nutrients, in particular, fatty acids. Polyunsaturated fatty acids (PUFAs) are cytotoxic to cancer cells and play a critical role in the treatment of multiple sclerosis (MS) and diabetes mellitus (DM). PUFAs are produced in the body by desaturases and elongases from dietary essential fatty acids (EFAs), primarily involving delta-6-desaturase (D6D). D6D is a rate-limiting enzyme for maintaining many aspects of lipid homeostasis and normal health. D6D is important to recognize the mechanisms that regulate the expression of this enzyme in humans. A lower level of D6D was seen in breast tumors compared to normal tissues. Interestingly, the elevated serum level of D6D was seen in MS and DM, which explains the critical role of D6D in inflammatory diseases. Methods: We searched databases of PubMed, Web of Science (WOS), Google Scholar, Scopus and related studies by predefined eligibility criteria. We assessed their quality and extracted data. Results: Regarding the mTOR signaling pathway, there is remarkable contributions of many inflammatory diseases to attention to common metabolic pathways are depicted. Of course, we need to have the insights into each disorder and their pathological process. The first step in balancing the intake of EFAs is to prevent the disruption of metabolism and expression of the D6D enzyme. Conclusions: The ω6 and ω3 pathways are two major pathways in the biosynthesis of PUFAs. In both of these, D6D is a vital bifunctional enzyme desaturating linoleic acid or alpha-linolenic acid. Therefore, if ω6 and ω3 EFAs are given together in a ratio of 2: 1, the D6D expression will be down-regulated and normalized.

Anticancer Effect of Cisplatin-Loaded Poly (Butylcyanoacrylate) Nanoparticles on A172 Brain Cancer Cells Line

Background: Drug delivery systems have been designed to achieve targeted delivery and control the release rate of the drugs. A serious challenge associated with drug delivery systems is the presence of the blood-brain barrier which limits drugs penetration. In the current study, the effects of cisplatin nanoparticles on A172 brain cancer cell line were investigated. Methods: Cisplatin nanoparticles were produced by miniemulsion polymerization technique and their properties were evaluated. Drug release assay was performed to characterize the nanoparticles’ properties. Here, we examined the effects of cisplatin nanoparticles and free form of cisplatin on A172 cancer cell line. MTT assay was performed for different concentrations of the drug. To measure the apoptosis rate in A172 cell line in the presence of cisplatin nanoparticles or its free from, Annexin V staining method was used. Results: Our results indicated that loading type of cisplatin was physical loading and only 4.7% of cisplatin was released after 68 h. Furthermore, MTT assay showed that cisplatin nanoparticles in all concentrations had more cytotoxic effects on the cells comparing with the free form of cisplatin and control groups. We also showed that cisplatin nanoparticles could increase apoptosis in cancer cells more than the drug in the free form by using flow cytometry technique. Conclusion: Overall, these findings proved that cisplatin loaded on poly (Butylcyanoacrylate) nanoparticles, was more efficient than the free form of cisplatin in treating A172 cancer cell line.