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Introduction: Celiac disease (CD) or gluten-sensitive enteropathy is a malabsoption of nutrients due to hyoersesitivity of gluten. Some etiologic facrors are environmental, immunologic and genetic factors. The frequancy of Celiac disease is not studied in western regions of Iran, therefore this study is done to determine the frequancy of Celiac disease in general population of rural regions of Arak. Materials and Methods: This is a descriptive, cross-sectional study in which 700 people between 20-56 years old in rural regions of Arak were selected by multistage random sampling (364 male and 336 female). After completing questionnaires, blood samples were collected and serum IgA levels (to rule out IgA deficiency), and serum t-TG Ab were assessed. All cases that had positive serologies and those who had high clinical probability of having Celiac disease underwent second duodenal segment biopsy. Data was presented using mean, standard deviation and frequency distribution. Results: Serum IgA levels were normal in all samples. 8 cases were positive for t-TG Ab, 38 cases had high normal levels of t-TG Ab and the others had less than 6 Au/ml t-TG Ab. Only in patients with high normal serology, histology was positive. 1% (10 in 1000 people) of all studied subjects demonstrated intestinal lesions due to Celiac disease. Most of them were asymptomatic. Conclusion: CD frequency in rural regions of Arak in people between 20-65 years old was 10 among 1000 cases. This frequency is the same as studies done in northern and southern regions of Iran but was higher comparing to the other parts of the word. This amplifiles the importance of screening of CD in Iran. Also the sensitivity and specificity of t-TG Ab was found high because all cases with high normal levels of t-TG Ab were approved by histology.

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Background: Cancer stem cells are subpopulation of cancer cells that show self-renewal potential and the capacity to differentiate into diverse populations comprising a tumor. One of the characteristics of CSCs is their ability to form floating spheroids under anchorage-independent conditions in a serum-free media. The aim of this study was isolation of colon cancer stem cells by sphere formation assay and characterization of them in human colonic adenocarcinoma HT-29.

Materials and Methods: In this experimental study, colon CSCs markers including CD44 and EPCAM in spheroid and HT-29 cells were analyzed by flow cytometry. The expression levels of stemness genes in both spheroid and HT-29 cells were investigated using real-time PCR. Tumorigenic potential of spheroid cells was evaluated using in vivo xenografts assay.

Results: Our data showed over 92% of spheroids were CD44+/EpCAM+, while HT-29 cells only have expressed 37% of CD44/EpCAM markers. In compared with the HT-29 cells, expression levels of ‘‘stemness’’ genes, like Sox2, Oct4, Nanog, C-myc, and Klf4 were significantly increased in spheroid cells (p< 0.05). Further, As little as 2500 spheroid cells were sufficient to obtain tumor growth in nude mice, while 1x106 of HT-29 cells was needed to form tumor.

Conclusion: Our data suggest that spheroid formed by colon cancer cell lines highly enriched in CSCs and showed increasing expression of stemness genes and tumorigenic in nude mice.