A systematic survey of LU domain-containing proteins reveals a novel human gene, LY6A, which encodes the candidate ortholog of mouse Ly-6A/Sca-1 and is aberrantly expressed in pituitary tumors / 医学前沿

The Ly-6 and uPAR (LU) domain-containing proteins represent a large family of cell-surface markers. In particular, mouse Ly-6A/Sca-1 is a widely used marker for various stem cells; however, its human ortholog is missing. In this study, based on a systematic survey and comparative genomic study of mouse and human LU domain-containing proteins, we identified a previously unannotated human gene encoding the candidate ortholog of mouse Ly-6A/Sca-1. This gene, hereby named LY6A, reversely overlaps with a lncRNA gene in the majority of exonic sequences. We found that LY6A is aberrantly expressed in pituitary tumors, but not in normal pituitary tissues, and may contribute to tumorigenesis. Similar to mouse Ly-6A/Sca-1, human LY6A is also upregulated by interferon, suggesting a conserved transcriptional regulatory mechanism between humans and mice. We cloned the full-length LY6A cDNA, whose encoded protein sequence, domain architecture, and exon-intron structures are all well conserved with mouse Ly-6A/Sca-1. Ectopic expression of the LY6A protein in cells demonstrates that it acts the same as mouse Ly-6A/Sca-1 in their processing and glycosylphosphatidylinositol anchoring to the cell membrane. Collectively, these studies unveil a novel human gene encoding a candidate biomarker and provide an interesting model gene for studying gene regulatory and evolutionary mechanisms.

The correlation analysis between helicobacter pylori infection and gastric polypus / 重庆医学

Objective To investigate the correlation between gastric polyps and helicobacter pylori (Hp) infection .Methods 150 patients with gastric polyps(experimental group) and 150 patients with chronic gastritis(control group) from October 2011 to No-vember 2012 in Shapingba people′s hospital of Chongqing were enrolled in this study .The polyps biopsy in patients with gastric polyps and the mucosa in gastric antrum big and small bends ,and the anterior and posterior walls(about 2-5 cm from the pylorus) from both groups were detected for the pathological type ,inflammation degree and stained(modified Giemsa staining) for detection of the existence of Hp .Results In 150 patients with gastric polyps ,58% (87/150) of the cases were infected by Hp mainly in medi-um and low degree ,in which 39 .3% (59/150) of the infection located at polyps and 42% (63/150) of the infection occurred out of polyps .Pathological analysis for this group further demonstrated that the types of hyperplastic polyps ,fundic gland polyps ,inflam-matory polyp and adenomatous polyps accounted for 68 .0% (102 cases) ,20 .7% (31 cases) ,9 .3% (14 cases) and 2 .0% (3 cases) of total 150 gastric polyps cases ,of which 63 .7% (65/102) ,38 .7% (12/31) ,57 .1% (8/14) and 66 .7% (2/3) cases were infected by Hp ,respectively .Pathological analysis also indicated that ,among total 150 gastric polyps cases ,single polyps and multiple polyps types accounted for 62 .0% (93 cases) and 38 .0% (57 cases) .The polyps commonly existed at gastric fundus in which the incidence rate of the hyperplastic polyps type and the fundic gland polyps type were 94 .1% (96/102) and 87 .1% (27/31) ,respectively .The infection rate in hyperplastic polyps was markedly higher than that in fundic gland polyps (P<0 .05) ,and the infection of hyperplas-tic polyps was mainly medium and high degrees .In addition ,the inflammatory response in the hyperplastic polyps was higher ,ac-companied by the intestinal metaplasia and atrophy of gastric mucosa ,as compared with non-hyperplastic polyps .In the total 150 control cases ,52 .0% (78/150) patients were infected by Hp with mainly medium and high degree .Results indicated that there is no relationship between polyps occurring and Hp infection .Conclusion Compared to the chronic gastritis ,there is no positive associa-tion between gastric polyps and Hp infection .There is no remarkable difference for Hp infection rate and degree between the polyps and the non-polyps sites in the stomach .The infection rate and infection degree of hyperplastic polyps is significantly higher than that of fundic polyps .However ,the underlying mechanisms for the development of hyperplastic polyps have to be elucidated in the future .