Juglone-ascorbate treatment enhances reactive oxygen species mediated mitochondrial apoptosis in pancreatic cancer

BACKGROUND

Treatment of Pancreatic Cancer (PC) is challenging due to its aggressiveness and acquired resistance to conventional chemotherapy and radiotherapy. Therefore, the discovery of new therapeutic agents and strategies is essential. Juglone, a naphthoquinone, is a secondary metabolite produced naturally in walnut-type trees having allelopathic features in its native environment. Juglone was shown to prevent cell proliferation and induce ROS-mediated mitochondrial apoptosis. Ascorbate with both antioxidant and oxidant features, shows selective cytotoxicity in cancer cells.

METHODS AND RESULTS

In this study, we evaluated the anticancer effects of Juglone in combination with ascorbate in PANC-1 and BxPC-3 PC cells. The MTT assay was used to determine the IC50 dose of Juglone with 1 mM NaAscorbate (Jug-NaAsc). Subsequently, the cells were treated with 5, 10, 15 and 20 µM Jug-NaAsc for 24 h. Apoptotic effects were evaluated by analyzing the following genes using qPCR; proapoptotic Bax, antiapoptotic Bcl-2 related to the mitochondrial apoptotic pathway and apoptosis inhibitor Birc5 (Survivin). Immunofluorescence analysis was performed using Annexin V-FITC in PC cells. As an antioxidant enzyme, Trx2 protein levels were determined by a commercial ELISA test kit. Jug-NaAsc treatment decreased the expressions of antiapoptotic genes Bcl-2 and Birc5 while the apoptotic gene Bax expression increased at all doses. Additionally, a dose-dependently increase of apoptosis according to immunofluorescence analysis and the decreases of Trx2 enzyme levels at all treatments in both cell lines supported gene expression results.

CONCLUSION

Our results suggest that Juglone is a potential anticancer agent especially when combined with ascorbate.

The effects of Juglone-Selenium combination on invasion and metastasis in pancreatic cancer cell lines

Background: Pancreatic cancer does not show any symptoms in the early period and metastatic process is already passed when the diagnosis is done. Therefore, in the battle with pancreatic cancer, novel treatment strategies, particularly antiinvasive and antimetastatic strategies, are needed. The cytotoxic and anticancer effects of juglone and sodium selenite (NaSe) have been showed in various cancer cells. Objectives: In this study, it is aimed to investigate the synergistic effects of juglone and selenium on PANC-1 and BxPC-3 pancreatic cancer cells. Methods: Antimetastatic effects of juglone-NaSe were carried out by adhesion and invasion assays and the genes and protein expressions. Expression analysis of the CDH1, ITGB3 and COL4A3 genes and their proteins E-cadherin, β3 integrin and tumstatin which play role in metastasis and angiogenesis processes, were done by qPCR and immunohistochemical analysis, respectively. Results: Study findings have provided evidences that the juglone-selenium has a cytotoxic and dose dependent suppressive effect on invasion and metastasis in PANC-1 and BxPC-3 cells. Conclusion: The juglone-NaSe has the potential to be a promising agent especially to inhibit invasion and metastasis in pancreatic cancer treatment. However, more in depth studies are needed to more clearly demonstrate the effects of juglone-selenium. Keywords: Pancreatic cancer cell lines; juglone-selenium; invasion; metastasis.

Type 2 diabetes is associated with the MTNR1B gene, a genetic bridge between circadian rhythm and glucose metabolism, in a Turkish population

Type 2 diabetes (T2D) is a complicated public health problem in Turkey as well as worldwide. Genome-wide approaches have been guiding in very challenging situations, such as the elucidation of genetic variations underlying complex diseases such as T2D. Despite intensive studies worldwide, few studies have determined the genetic susceptibility to T2D in Turkish populations. In this study, we investigated the effect of genes that are strongly associated with T2D in genome-wide association (GWA) studies, including MTNR1B, CDKAL1, THADA, ADAMTS9 and ENPP1, on T2D and its characteristic traits in a Turkish population. In 824 nonobese individuals (454 T2D patients and 370 healthy individuals), prominent variants of these GWA genes were genotyped by real-time PCR using the LightSNiP Genotyping Assay System. The SNP rs1387153 C/T, which is located 28 kb upstream of the MTNR1B gene, was significantly associated with T2D and fasting blood glucose levels (P < 0.05). The intronic SNP rs10830963 C/G in the MTNR1B gene was not associated with T2D, but it was associated with fasting blood glucose, HbA1C and LDL levels (P < 0.05). The other important GWA loci investigated in our study were not found to be associated with T2D or its traits. Only the SNP rs1044498 (A/C variation) in the ENPP1 gene was determined to be related to fasting blood glucose (P < 0.05). Our study suggests, consistent with the literature, that the MTNR1B locus, which has a prominent role in glucose regulation, is associated with T2D development by affecting blood glucose levels in our population.

Juglone can inhibit angiogenesis and metastasis in pancreatic cancer cells by targeting Wnt/β-catenin signaling

OBJECTIVES

We aimed to investigate the effects of juglone on angiogenesis, metastasis and cell proliferation processes in pancreatic cancer  (PC)  and to understand whether its possible effects occur via the Wnt signaling pathway by analyzing the expression levels of target genes of Wnt signaling.

BACKGROUND

PC is a silent and lethal cancer type which can only be detectable after metastasis and angiogenesis processes occured. The Wnt signaling pathway is one of the pathways that plays an active role in many biological processes in the cell. Mutations in the genes of this signaling pathway are related to the development of many cancers. Juglone, a natural compound, is shown to have cytotoxic and apoptotic effects on various cancer cells.

METHODS

PANC-1 and BxPC-3 pancreatic cancer cells were treated with juglone at <IC50 doses (5, 10, 15, and 20 μM) for 24 h. Expression levels of MMP7, VEGF, TCF7L2, CCND1 genes were determined by RT-PCR. Cell migration evaluation after juglone treatments were done by a wound-healing assay.

RESULTS

Juglone seems to be able to inhibit angiogenesis and metastasis by affecting the activity of Wnt signaling target genes in human PC cell lines.

CONCLUSION

Juglone has a promising potential to develop new strategies for the treatment of PC (Tab. 2, Fig. 4, Ref. 35).

PIK3R1 gene polymorphisms are associated with type 2 diabetes and related features in the Turkish population

BACKGROUND

The phosphatidylinositol 3-kinase p85 alpha regulatory subunit 1 gene (PIK3R1) encodes the PIK3R1 protein, which plays a direct role in insulin signaling. PIK3R1 (p85 regulatory subunit) connects firmly with the p110 catalytic subunit, and together these proteins form the phosphatidylinositol 3-kinase (PI3K) protein. PI3K is a key protein in the Akt signaling pathway, which regulates cell survival, growth, differentiation, glucose trafficking, and utilization. Defects in the insulin signaling cascade play an important role in the development of insulin resistance, which shares a common genetic basis for metabolic diseases such as type 2 diabetes (T2D), obesity and cardiovascular diseases.

OBJECTIVES

In our study, we investigated the effect of single nucleotide polymorphisms (SNPs) rs3756668 in 3'UTR region, rs706713 and rs3730089 in exons 1 and 6, respectively, rs7713645 and rs7709243 in intron 1, and rs1550805 in intron 6 of PIK3R1 gene on T2D.

MATERIAL AND METHODS

This study enrolled a total of 840 individuals, including 427 diabetic individuals (206 obese and 221 non-obese) and 413 nondiabetic individuals (138 obese and 275 non-obese). The target SNPs were analyzed using real-time polymerase chain reaction (RT-PCR). Statistical analysis was performed using SPSS18.0 (IBM Corp., Armonk, USA). The p-values ≤0.05 were considered statistically significant.

RESULTS

The SNPs rs706713 (Tyr73Tyr) and rs3730089 (Met326Ile) located in exons, and rs7713645, rs7709243 and rs1550805 located in introns were determined to be significantly associated with T2D and phenotypic features such as obesity, insulin resistance and the lipid parameters. The association with SNP rs3756668, which is located in the 3'UTR, was not significant.

CONCLUSIONS

Our study supports the role of PIK3R1, an important candidate gene due to its critical role in insulin signal transduction, in T2D development.

IRS1 gene polymorphisms Gly972Arg and Ala513Pro are not associated with insulin resistance and type 2 diabetes risk in non-obese Turkish population

Insulin receptor substrate 1 (IRS1), plays a critical role in insulin signaling and its control has an important place in the development of insulin resistance. The tyrosine phosphorylation of IRS1 serves as docking molecules for downstream effectors such as Phosphatidylinositol 3-kinase and phosphotyrosine phosphatase-2. We focused on the Gly972Arg and Ala513Pro variants of the IRS1 gene, since these specific allelic variants are located near the Tyr-Met-X-Met (YMXM) motifs around Tyr987 and Tyr612. Thus, we aimed to investigate the effects of Gly972Arg/Ala513Pro polymorphisms in IRS1 gene on development of insulin resistance and the risk of type 2 diabetes in a non-obese Turkish population. This work included 306 individuals comprising 178 subjects with type 2 diabetes and 128 healthy subjects matched for body mass index. Gly972Arg/Ala513Pro polymorphisms had no effect on type 2 diabetes risk and its phenotypes (P > 0.05). Although IRS1 gene and its variants are associated with type 2 diabetes and insulin resistance in several studies worldwide, our data showed that there is no association between Gly972Arg and Ala513Pro variants in IRS1 and disease in Turkish population.

The Adiponectin variants contribute to the genetic background of type 2 diabetes in Turkish population

Adiponectin, an adipose tissue specific protein encoded by the Adiponectin gene, modulates insulin sensitivity and plays an important role in regulating energy homeostasis. Many studies have shown that single nucleotide polymorphisms (SNPs) in the Adiponectin gene are associated with low plasma Adiponectin levels, insulin resistance and an increased risk of type 2 diabetes mellitus. The aim of the present study was to evaluate the contribution of the Adiponectin gene polymorphisms in genetic background of type 2 diabetes in a Turkish population. In total, 169 unrelated and non-obese diabetic patients and 119 age- and BMI-matched nondiabetic individuals with no family history of diabetes were enrolled in this study. We detected a significant association between type 2 diabetes and two SNPs: SNP −11391G N A, which is located in the promoter region of the Adiponectin gene, and SNP +276G N T, which is found in intron 2 of the gene (P b 0.05). The silence SNP G15G (+45TN G) in exon 1 and SNP+349ANG in intron 2 also showed a weak association with type 2 diabetes (P=0.06 and P=0.07, respectively),while SNPs−3971ANG in intron 1 and Y111H, R112C and H241P in exon 3 showed no association (P N 0.05). In conclusion, these findings suggest that Adiponectin gene polymorphisms might be effective on susceptibility for type 2 diabetes development which emerged from the interactions between multiple genes, variants and environmental factors.