L��� ���-������ RNA� ����RNA�� ��� ����� ����-L��� ���-������ RNA� ����RNA�� ��� ����� ����tified potential biological and gene regulators. Similar to other cell-free circulating cancer-related nucleic acids, lncRNAs are released in the peripheral circulation of cancer patients and allow for non-invasive gene expression assessment. lncRNAs are considered to be promising biomarkers for cancer prognosis and diagnosis. Several lncRNAs have been found to regulate developmental processes in a number of biological disorders. Recent studies indicated that lncRNAs are associated with numerous diseases, most notably cancer, as they were found to be highly expressed or silenced in a number of human cancers, including colorectal cancer (CRC). Despite advances in the current detection methods, over half of cancer patients succumb to the disease, as several CRC cases are diagnosed at an advanced stage. Due to the lack of non-invasive and low-cost prognostic and diagnostic tests for CRC, the identification of novel, potentially effective biomarkers has been attracting increasing attention in recent cancer research. The present review focused on the most widely applied lncRNAs in cancer detection, including CRC, in vitro.

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Background. Many epidemiological studies have shown that vitamin D deficiency is associated with various types of human cancers. The biological action of vitamin D and its metabolites is mediated by the transcription factor vitamin D receptor (VDR). The VDR gene is highly expressed in the colon and is involved in many biological functions. The aim of the current study was to assess the relationship between serum vitamin D metabolite and calcium levels with VDR polymorphisms in normal and colorectal cancer (CRC) patients. Methods. Fifty Saudi CRC patients and fifty controls were enrolled in the study. The levels of total vitamin D, 25(OH)D3, and calcium were measured in serum. Results. The homozygous genotype (aa) of the ApaI VDR polymorphism (rs7975232) was found to correlate with total serum vitamin D levels of CRC patients, while the heterozygous (Tt) TaqI VDR polymorphism (rs731236) was associated with serum calcium levels. In contrast, the BsmI and FokI VDR polymorphisms (rs1544410 and rs2228570, resp.) did not affect the serum levels of total vitamin D, 25-hydroxyvitamin D3, and calcium. Conclusion. Appropriate vitamin D levels were shown to be important in preventing the onset of CRC.

BACKGROUNDA relationship between estrogen and leptin has been described during the follicular phase of both spontaneous menstrual cycles and cycles stimulated with exogenous follicle-stimulating hormone (FSH), which suggest that leptin has either a direct effect on or is regulated by gonadal steroids in the human ovary. To examine the changes in plasma leptin levels during the menstrual cycle, we studied the association between plasma leptin and reproductive hormones in young, healthy Saudi women.SUBJECTS AND METHODSSixty-five young women between 19 to 39 years of age, with a normal menstrual cycle, were grouped into 33 overweight and obese females of BMI >25 kg/m2, and 32 lean females of BMI <25 kg/m2. Anthropometrics measurements were made at the time of the collection. Samples were analyzed for leptin, progesterone, estradiol (E2), FSH, luteinizing hormone (LH), cortisol, and testosterone concentrations.RESULTSOverweight and obese women, compared with lean, tended to have a significantly higher plasma leptin levels (11.38± 4.06 vs. 6.22± 2.87 ng/mL; P=0.05). In overweight and obese subjects, circulating leptin concentrations showed a direct correlation with BMI (r=0.53; P=0.002), hip circumference (r=0.32; P=0.005), waist-hip ratio (r=0.37; P=0.042), weight (r=0.41; P=0.021), and E2 on day 3 (r=0.35; P=0.048). In all correlation analyses, leptin levels did not correlate with cortisol or testosterone. In lean subjects, a bivariate correlation analysis showed that plasma leptin concentrations were directly correlated to hip circumference (r=0.43; P=0.012). Moreover, a direct correlation was found with progesterone on day 10 (r=0.43; P=0.014) and E2 on day 24 (r=0.47; P=0.007).CONCLUSIONThere is a link between plasma leptin and progesterone concentrations during the menstrual cycle, and the variation in circulating estradiol concentrations may have an influence on circulating leptin in female subjects.

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Plasmids are genetic elements of DNA molecules in the form of small circles present within the bacterial cell cytoplasm outside the bacterial chromosome. Because they are separate from the chromosome, they reproduce independently. However, plasmids are bound to multiply in the cell by multiplying the chromosome. Plasmids differ in size and number of copies in the cell. Plasmids carry genes that add to the cell additional properties, but they are not necessary for cell life and do not affect cell vitality. Some chemicals can remove plasmids from the cell by stopping their proliferation. By bacterial cell multiplication, the number of plasmids decreases until bacterial cells free from the plasmids are obtained. Plasmids are used in the techniques and research of genetic engineering and gene therapy by gene transfer to bacterial cells or to cells of superior organisms, whether other plants, animals, or other living organisms, to improve their resistance to diseases or to improve their growth rates or to improve any other required traits.

Background: Polymorphisms in the gene encoding the vitamin D receptor (VDR) affect the protective role of vitamin D against many types of cancers, including colorectal cancer (CRC). Objective: The objective of this study was to assess the effect of four major polymorphisms of the VDR gene ( ApaI , TaqI , BsmI and FokI ) on the risk of CRC in a Saudi population. Materials and Methods: This case–control study recruited 132 CRC patients from the oncology clinics at King Abdulaziz University Hospital and 124 healthy controls from the blood bank at King Fahad General Hospital, Jeddah, Saudi Arabia, between September 2017 and August 2018. All participants were Saudis and aged 20–80 years. Genomic DNA samples were extracted from the peripheral blood cells and amplified with polymerase chain reaction. The resulting fragments were digested with different endonucleases to reveal the genotypes using the restriction fragment length polymorphism technique. The genotype distribution and allele frequency, odds ratio (OR), risk ratio (RR) and P values were determined with contingency table analysis following Hardy–Weinberg equilibrium equation. Results: For the ApaI single-nucleotide polymorphism (SNP) (rs7975232), only the heterozygous (Aa) genotype increased the risk of CRC (OR = 3.4, RR = 2.3, and P < 0.0001), whereas the TaqI SNP (rs731236) carriers with either the heterozygous (Tt) or homozygous (tt) genotype displayed an increased risk for the disease (OR = 6.18, RR = 4, P < 0.0001; OR = 3, RR = 2.4, P = 0.02, respectively). In contrast, heterozygous (Bb) and homozygous (bb) carriers of the BsmI SNP (rs1544410) had significantly lower risk for CRC ( P < 0.0001). Finally, for the FokI SNP (rs2228570), there was no association with CRC risk. Conclusion: This study found that VDR SNPs ApaI and TaqI increase the risk of CRC, whereas BsmI reduces the risk of CRC in the selected Saudi population. Therefore, ApaI and TaqI SNPs could potentially be used as a diagnostic biomarker for CRC. However, the molecular mechanisms by which these variants increase or decrease the risk of CRC need to be investigated.

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