Expression of CD133 as a cancer stem cell marker in invasive gastric carcinoma.

INTRODUCTION: Gastric cancer is considered to be the fourth most common malignancy worldwide and the second cause of cancer deaths. Regarding the cancer stem cells (CSCs) theory, they are a small group of tumor cells with unrestricted self-renewal and differentiation abilities that help tumor formation. There is an interest in the utility of CD133 as a promising marker to detect the tumor stem cell population for a variety of solid malignancies including gastric cancer. Tumors that express stem cell markers such as CD133 are found to be more aggressive tumors with poor prognosis and high liability for recurrence. This study aimed to evaluate the immunohistochemical expression of CD133 in invasive gastric carcinoma and study the relation between CD133 immunohistochemical expression and different clinicopathological parameters. MATERIAL AND METHODS: 77 cases of gastric carcinoma were collected from the surgical pathology unit at the Gastroenterology Center, Mansoura University, Egypt. CD133 expression in tumor tissue was evaluated by immunohistochemistry. RESULTS: CD133 expression positively correlated with tumor metastasis and recurrence. Multivariate analysis revealed CD133 positivity to be an independent prognostic factor for tumor recurrence (P = 0.03). CONCLUSION: CD133 is a good marker that can predict tumor recurrence and metastasis in gastric carcinoma. Even though, studies regarding CSCs are still in their initial stages especially those related to CD133 in gastric cancer.

Development of a germfree mouse model of Vibrio cholerae infection.

A mouse model of Vibrio cholerae infection was successfully developed with germfree mice. Three- to four-week-old germfree mice were orally inoculated with strains of V. cholerae to be tested and then moved to normal housing after inoculation. Stool culture, measurement of serum vibriocidal antibody titers, and determination of immune responses to the cholera toxin B subunit demonstrated that germfree mice are readily colonized by V cholerae and develop systemic and mucosal immune responses to antigens expressed by these organisms. Immune responses to the B subunit of Shiga toxin 1, which was expressed from a V. cholerae vaccine vector, were less pronounced. This model should be valuable for studying immune responses to V. cholerae infection and immunization, including responses to heterologous antigens expressed by cholera vector strains.