👤 Kamran Ghaedi

Obesity is one of the risk factors concerns of colorectal cancer (CRC), the most common type of gastrointestinal cancer, due to the changing lifestyle and especially diet. There are various molecular pathways associated with obesity and the risk of CRC incidence, such as insulin resistance or elevated plasma free fatty acids, which alter the signaling pathways of intestinal epithelial cells. The aim of this study was to better understand the significance of unsaturated fatty acid biosynthesis on pathogenesis of colon cancer in obese. Based on GSE20931 dataset, obese individuals affected by CRC had higher increased gene expression than non-obese individuals. The analysis showed that in obese individuals, the 16 signaling pathway genes were activated and increased (FDR <0.05) significantly. The biosynthetic pathway of unsaturated fatty acids showed a cross-talk with the arachidonic acid metabolism pathway and the PPAR signaling pathway is influenced and regulated via these pathways. The biosynthetic pathway of unsaturated fatty acids consisting of 22 genes, were analyzed using GEO data and revealed that 4 genes (HSD17B12, TECR, FADS2, ELOVL5) from this pathway were significantly increased (FDR <0.05). These data were validated based on TCGA data (Adj.p.value <0.001). The expression level of candidate genes in HT-29 cells decreased significantly (P.value <0.01), and PPARγ expression increased under linoleic acid treatment (200 μM) compared to control cells. Moreover, in presence of linoleic acid treatment, migration, colony formation, and proliferation decreased (P.value <0.01) in presence of treatment. In summary, the Biosynthesis pathway of unsaturated fatty acids is an interesting and critical pathway in CRC. Show less

Transcription factors (TFs) are essential for many biological processes and regulate the expression of several genes. This study's objective was to analyze the abnormalities in TF expression, their impact on patient prognosis, and related pathways in colorectal cancer (CRC). The expression alterations of all TFs were investigated using the cancer genome atlas and GSE39582 data. Clinical data were also used to study the association between TFs expression and patient prognosis through the Cox regression test, and a predictive model of CRC patient survival was constructed based on TFs expression. Co-expression network was used to discover TF-related pathways. To validate the findings, the RT-qPCR method was applied to CRC samples and adjacent normal tissue. The findings revealed that ANKZF1, SALL4, SNAI1, TIGD1, LEF1, FOXS1, SIX4, and ETV5 expression levels increased in both cohorts and were linked to the poor prognosis. NR3C2, KLF4, CASZ1, FOXD2, ATOH1, SALL1, and RORC expression, on the other hand, exhibited a significant decrease, and their increase was related to the good prognosis of patients. The patient mortality risk model based on expression of mentioned TFs revealed that, independent of clinical characteristics, the expression of ANKZF1, LEF1, CASZ1, and ATOH1 could accurately predict patient survival rates. According to the co-expression network, increased transcription factors were linked to metastatic pathways, while decreasing TFs were involved to apoptotic pathways. RT-qPCR findings showed that FOXS1 expression was markedly overexpressed in CRC samples. However, in CRC samples, the expression of CASZ1 decreased. In CRC, TFs expression of ANKZF1, LEF1, CASZ1 and ATOH1 are deregulated, which are associated with prognosis in patients. According to our findings, changes in the expression of the mentioned TFs have the potential to be considered diagnostic and prognostic biomarkers for CRC patients. Show less

Liver X receptor α (LXRα) is a member of the ligand-activated transcription factor of nuclear hormonal receptor superfamily, whose activation leads to modulation in the expression of genes involved in cholesterol homeostasis including ATP-binding cassette transporter A1 (ABCA1), which plays a crucial role in plasma high-density lipoprotein cholesterol (HDL-C) remodeling. The purpose of this study was to investigate whether endurance training enhanced the expression level of liver LXRα gene. Twelve adult male Wistar rats (200-220 g) were divided into control and training groups. Training group received exercise on a motor-driven treadmill at 28 m/min (0 % grade) for 60 min/day, 5 days/week for 8 weeks. Twenty-four hours after the last exercise session, the rats were killed and blood was taken from the right ventricle of each rat. Plasma was collected for HDL-C, low-density lipoprotein cholesterol (LDL-C), TC and TG measurements. Furthermore, a portion of the liver of each rat was excised and washed in ice-cold saline and frozen in liquid nitrogen for assessment of LXRα and ABCA1 mRNA levels. Data indicated significant increase in both LXRα and ABCA1 mRNA levels in trained rats, compared to control rats. Plasma HDL-C concentration was significantly higher (P < 0.001) in trained rats at the end of treadmill exercise. However, there was a significant decrease in LDL-C (P < 0.003), TG, TC concentration, TC/HDL-C and LDL/HDL-C ratios in trained rats compared with those in the control group (P < 0.001). In conclusion, we found that endurance training induced significant elevation in LXRα gene expression, which correlated with enhanced levels of ABCA1 mRNA and plasma HDL-C concentration. Show less

Study of molecular responses to central nervous system injury would be helpful for controlling the harmful pathways post-injury and triggering the useful pathways required for the treatment of injury. To investigate the expression level of liver X receptor α (LXRα) which has anti-inflammatory effects and pro-apoptotic Bcl-2-associated X protein (Bax) upon spinal cord injury (SCI). To induce SCI, transection was carried out at T9 level of male Wister rats. Approximately 8 mm of rostral, caudal, and epicenter tissues of injured sites in treated rats were chosen for quantitative real-time polymerase chain reaction at the 6, 24, and 72 hours, and 7 and 10 days post-surgery. Our results showed a complicated temporal and spatial pattern of alteration in LXRα and Bax mRNA expression levels after SCI. LXRα expression level followed a homologues pattern (additive and subtractive wave) with a difference in time at three areas of studied. Rostral, caudal, and epicenter expression patterns of Bax were dissimilar in these areas. Gradual increase in the expression of Bax without any decrease at the rostral area was observed, presumably indicating the active transcription process of this gene, regardless of its protein situation. A time lapse significant change in Bax expression level was observed only in the epicenter of injury, emphasizing that apoptotic responses are limited to this area. Furthermore, an increase in LXRα transcription level was observed first in rostral area and then extended to epicentral and caudal areas, implying that inflammation responses extended from rostral to caudal areas. Show less