Differential effects of docosahexaenoic acid (DHA) and linoleic acid (LA) on miR-101 and miR-342 tumor suppressor microRNAs in Taxol-treated HER2-positive breast cancer cells.

BACKGROUND & AIMS: Docosahexaenoic acid (DHA) and linoleic acid (LA) have been shown to exhibit anti-proliferative effects against breast cancer cells. However, the mechanisms underlying these effects are not yet fully understood. One potential mechanism is through the regulation of microRNAs (miRs), which are known to play a crucial role in breast cancer development and progression. This study aimed to investigate the expression of miR-342 and miR-101 as tumor-suppressor miRs in the human HER-2 positive breast cancer cell line BT-474 after treatment with DHA, LA, alone or in combination with Taxol, a standard chemotherapy agent. METHODS: The human breast cancer cell line BT-474 was cultured, and the IC50 for Taxol was determined using the MTT assay. Cells were then cultured and treated for 24 h with 100 µM DHA and 50 µM LA, alone or in combination with the respective IC50 of Taxol. Cells were harvested, and miRNA extraction and cDNA synthesis were performed using standard methods. Expression levels of miRs were analyzed using quantitative real-time PCR (qRT-PCR), and results were normalized against U6 snRNA expression levels. RESULTS: The Taxol IC50 for BT-474 cells was 19 nM. According to the data obtained from our study, it was observed that Taxol treatment resulted in the down-regulation of both miR-101 and miR-342 (3.69 (p < 0.0001) and 1.88 fold, (p < 0.0001) respectively). In addition, DHA, LA and DHA + LA caused up-regulation of miR-101 (0.11, 0.05, 0.03 fold (p < 0.0001) respectively) but not miR-342 (decreased by 1.93 (p < 0.0001), 2.89 (p < 0.0001) and 1.19 fold (p = 0.0029) respectively). Notably, treatment with DHA, LA and DHA + LA was able to restore the down-regulated expression of miR-101 (0.25 (p < 0.0001), 0.05 (p = 0.0012) and 0.06 fold (p < 0.0001) respectively) during Taxol treatment. CONCLUSION: Our study demonstrates that DHA and LA can effectively compensate for the reduced expression of miR-101 during Taxol treatment. These findings suggest that dietary fatty acids may play a critical role in modulating the anti-cancer effects of chemotherapy agents. Future studies are needed to investigate the functional aspects of dietary fatty acids on breast cancer development and progression.

Docosahexaenoic acid (DHA) and linoleic acid (LA) modulate the expression of breast cancer involved miRNAs in MDA-MB-231 cell line.

BACKGROUND AND AIMS: Docosahexaenoic acid (DHA) and linoleic acid (LA) have modulatory effects on breast cancer (BC) cell lines. We aimed to investigate the effects of DHA, LA alone, in combination, and in the presence of paclitaxel on the expression of five microRNAs involved in the pathology of BC in MDA-MB-231 cell line. METHODS: MDA-MB-231 cells were treated with either DHA or LA or in combination in the presence/absence of paclitaxel (Taxol). Total RNA was extracted and cDNA synthesized from the cells before and after treatment. The expression levels of miR-30, miR-106b, miR-20, miR-126, and miR-194 were determined by quantitative real-time PCR (qPCR). RESULTS: Treatment of MDA-MB-231 cells with DHA modulated the gene expression of miR-30 (increased by 7.74-fold (p < 0.0001), miR-194 (decreased by 11-fold (p < 0.0001)), miR-106b (increased by 2.64-fold (p = 0.0004), miR-126 (decreased by 50-fold (p < 0.0001)), and miR-20 (decreased by 4-fold (p < 0.0001)). Additionally, treatment of MDA-MB-231 cells with LA modulated the gene expression of miR-30 (increased by 2.38-fold (p = 0.0001)), miR-194 (decreased by 100-fold (p < 0.0001)), miR-106b (decreased by 10-fold (p < 0.0001)). The combined DHA/LA treatment of MDA-MB-231 cells showed regulatory effect on the expression of studied microRNAs in which decreased the expression of miR-30 (5.5-fold (p < 0.0001)), miR-194 (11-fold (p < 0.0001)), miR-20 (3.5-fold (p = 0.0006)), and increased the expression of miR-106b (9.78-fold (p < 0.0001)). CONCLUSIONS: Modulation of the expression levels of BC-involved microRNAs could be one of the possible mechanisms of action through which DHA and LA may exert their biologic effects on MDA-MB-231 cell line.

Gallic Acid Exerts Nephroprotective, Anti-Oxidative Stress, and Anti-Inflammatory Effects Against Diclofenac-Induced Renal Injury in Malerats.

BACKGROUND/AIM: Diclofenac (DIC) is a Nonsteroidal anti-inflammatory drug (NSAID) and consumption of this drug creates side effects such as renal injury. The purpose of this work was to assess the influences of gallic acid (GA) on DIC-induced renal injury in rats. MATERIAL AND METHODS: Rats were segregated into five groups. Group 1, control group; Group 2 received DIC-only (50 mg/kg bw, i.p.) for 7 consecutive days; Groups 3, received GA-only (100 mg/kg bw, po) for 7 consecutive days; group 4 received DIC (50 mg/kg bw, i.p.) plus GA (50 mg/kg, po) for 7 consecutive days and group 5 received DIC (50 mg/kg bw, i.p.) plus GA (100 mg/kg, po) for 7 consecutive days. RESULTS: The data indicated that the levels of the serum protein carbonyl, sGOT, sGPT, urea, creatinine, uric acid, nitrite content, MDA, serum IL-1ß, and the renal IL-1ß gene expression were remarkably increased in DIC-only treated animals compared to control group. In the other hand, treatment with gallic acid led to significant improvements in abnormalities of DIC-induced oxidative stress and serum biochemical parameters. Histological changes were also ameliorated by GA oral administration. CONCLUSION: The results indicated that oral injection of GA could alleviate the noxious effects of DIC on the antioxidant defense system and renal tissue.

Docosahexaenoic acid (DHA) inhibits pro-angiogenic effects of breast cancer cells via down-regulating cellular and exosomal expression of angiogenic genes and microRNAs.

AIMS: Docosahexaenoic acid (DHA) as an omega 3 free fatty acid has been reported to exert anti-angiogenesis effects. However, our current understanding regarding the precise mechanisms of such effects is still limited. Exosomes secreted by cancer cells may act as angiogenesis promoters. The aim of the study was to determine altered expression levels of HIF-1α, TGF-ß, VEGFR, Snail1, Snail2 and SOX2 and their regulating microRNAs in MDA-MB-231 and BT-474 cell lines after treatment with DHA in both normoxic and hypoxic conditions. MAIN METHODS: Human breast cancer cell lines including MDA-MB-231 and BT-474 were treated for 24 h with 100 uM DHA under normoxic and hypoxic conditions. Exosomes were isolated from untreated and treated cells and characterized by transmission electron microscopy (TEM) and western blotting. RNAs from cells and isolated exosomes were extracted and cDNAs were synthesized. Expression levels of miRNAs and their pro-angiogenic target genes were analyzed using quantitative real-time PCR (qRT-PCR). KEY FINDINGS: We showed significant decrease in the expression of pro-angiogenic genes including HIF1-α, TGF-ß, SOX2, Snail1, Snail2 and VEGFR in cells and also their secreted exosomes after treatment with DHA in normoxic and hypoxic conditions. Also the expression levels of tumor suppressor miRs including miR-101, miR-199, miR-342 were increased and the expression levels of oncomiRs including mir-382 and miR-21 were decreased after treatment with DHA in cells and exosomes. SIGNIFICANCE: DHA can alter the expression of pro-angiogenic genes and microRNA contents in breast cancer cells and their derived-exosomes in favor of the inhibition of angiogenesis. Our data demonstrated new insight into DHA's anti-cancer action to target not only breast cancer cells but also their derived exosomes to suppress tumor angiogenesis.

Janus kinase inhibitors: A therapeutic strategy for cancer and autoimmune diseases.

Many cytokines are crucial drivers of cancers and autoimmune conditions. These proteins bind to receptors and signal their responses through Janus kinase (JAK) and signal transducer and activator of transcription (STAT) pathways. Genetic variations in the JAK-STAT pathway are correlated with the increased risk of cancers, autoimmunity as well as inflammatory diseases. Targeting JAKs and STATs can be a safe and efficacious strategy for treating these diseases. Tofacitinib, as the first JAK inhibitor, is approved for rheumatoid arthritis therapy. Also, many other JAK inhibitors have been proven or are in various phases of clinical trials for various diseases. At present, small-molecule JAK inhibitors are considered as a novel category of drugs in the treatment of cancer and immune-mediated diseases.

Docosahexaenoic acid suppresses migration of triple-negative breast cancer cell through targeting metastasis-related genes and microRNA under normoxic and hypoxic conditions.

There is insufficient evidence with respect to the effect of the standard anticancer therapeutic agents as well as common dietary supplements on the expression of such genes and microRNAs (miRNAs). Therefore, this study was aimed to study the effect of applying linoleic acid (LA) and docosahexaenoic acid (DHA) fatty acids alone or combined with Taxol on the expression of the matrix metalloproteinase (MMP)-9, MMP-2, vimentin, and talin2 genes, tumor-suppressor miR-194 and, onco-miR-106b in triple-negative breast cancer cell line, known as MDA-MB-231. MDA-MB-231 as metastatic breast cancer cell line was cultured and treated using 0.3 µM Taxol, 100 µM DHA, and 50 µM LA for 24 hours, alone or combined with Taxol under the normoxic and hypoxic conditions. Cells were harvested, after RNA extraction and complementary DNA synthesis, analysis of the expression levels of the studied genes and miRNAs was done through the use of the quantitative real-time polymerase chain reaction (qRT-PCR). Wound healing assay and Western blot analysis were also performed for confirmation. The results of qRT-PCR showed that treating the MDA-MB-231 cells with DHA caused an increase in the miR-194 expression and a decrease in the miR-106b expression, leading to the downregulation of the MMP-2 and MMP-9, and vimentin, and upregulation of the talin2 under the normoxic and hypoxic conditions. The results of the wound healing scratch assay revealed that the administration of the DHA and the DHA-Taxol combination caused the repression of cell migration in comparison with the control groups under the normoxic and hypoxic conditions. The results of the Western blot analysis demonstrated that DHA and the DHA-Taxol combination caused an increase in the expression of the talin2 protein rather than the control cells under both normoxic and hypoxic conditions. This study showed that DHA has significant antimetastatic effects against the triple-negative breast cancer cells. DHA could serve as a promising supplementation for suppressing the breast cancer cell migration, especially under the hypoxic condition.

DHA Abolishes the Detrimental Effect of Docetaxel on Downregulation of the MICA via Decreasing the Expression Level of MicroRNA-20a in Gastric Cancer.

BACKGROUND: MHC class I chain-related protein A (MICA) is a membrane glycoprotein expressed abnormally on some malignant cells including gastric cancer (GC) cell and elicits anti-tumor immune responses. Downregulation of MICA expression could lead to immune-evasion of cancer cells. OBJECTIVE(S): In this study, we aimed to investigate the effect of docosahexaenoic acid (DHA) and docetaxel alone or in combination on the expression level of MICA and its regulating microRNA (miRNA), miR-20a in MKN45 GC cell line. METHOD(S): MKN45 GC cell line was cultured and MTT assay was performed to determine IC50 of docetaxel. Cells were treated by 18.5 µM docetaxel and 100 µM DHA. After that, RNA extraction and cDNA synthesis were done and the expression level of MICA and miR-20a were determined by quantitative real-time PCR for both treated and untreated cell lines. RESULTS: Our findings showed less downregulation of the expression level of MICA by the combination of docetaxel/DHA (5.34-fold) compared with docetaxel (45.45-fold) and DHA (55.55-fold). Consistently, combination therapy led to the more downregulation of the expression level of the miR-20a (5.20-fold) in comparison to docetaxel (2.38-fold) and DHA (1.60-fold). CONCLUSION(S): As an unwanted effect of docetaxel therapy in GC, downregulation of MICA expression could lead to weak anti-tumor immune responses. By increasing the expression level of MICA, combination therapy of docetaxel with DHA would be useful to overcome this side effect.

Synergistic Beneficial Effect of Docosahexaenoic Acid (DHA) and Docetaxel on the Expression Level of Matrix Metalloproteinase-2 (MMP-2) and MicroRNA-106b in Gastric Cancer.

BACKGROUND: Gastric cancer (GC) is one of the most common cancers with the majority of patients recognized in advanced stages. The efficacy of using docosahexaenoic acid (DHA) as a supplementary agent has been suggested in treatment along with chemotherapeutics including docetaxel. However, the molecular signatures of such beneficial effects are not well-understood. OBJECTIVE(S): We aimed to evaluate the effects of DHA and docetaxel on the expression level of metastasis-related genes, including MMP-2 and talin-2, and their controlling miRNAs, miR-106b and miR-194, in metastatic GC cell line, MKN45. METHOD(S): GC cell line, MKN45, was cultured, and determination of IC50 of DHA was done by MTT test. Cells were treated with docetaxel, DHA, and their combination for 24 h, and then total RNA was extracted and cDNA synthesis was done using standard protocols. The expression level of target genes, MMP-2 and talin-2, and miR-106b and miR-194 were determined by using quantitative real-time PCR. RESULTS: The expression level of MMP-2 was decreased significantly in all treated cells. However, talin-2 showed significant downregulation only after treatment with docetaxel. In contrary to increased expression after treatment with docetaxel, DHA led to a significant under-expression of miR-106b. The similar effect was seen for miR-194. CONCLUSION(S): Combination of docetaxel and DHA led to the significant downregulation of MMP-2. Also, DHA lowered the docetaxel-mediated upregulation of miR-106b oncomiR. In conclusion, supplementation of docetaxel therapy with DHA in GC patients would be considered as a beneficial approach in cancer treatment.

The role of microRNAs regulating the expression of matrix metalloproteinases (MMPs) in breast cancer development, progression, and metastasis.

MicroRNAs (miRNAs) regulate several biological and physiological processes in mammalian cells, including cellular proliferation, differentiation, apoptosis, and metabolism. Recent studies have confirmed the alteration of them during the cancer development. Matrix metalloproteinases (MMPs), belonging to the large family of proteases, have also been demonstrated to play crucial roles in tissue remodeling, and to support cancer progression and metastasis. There are several known miRNAs which regulate the MMP family and their expression. The expression profiles of miRNAs involved in MMP regulation, change during cancer progression, and metastasis. The present review focuses on important miRNAs capable of targeting MMPs through direct and indirect interactions during the breast cancer development, progression, and metastasis.