Endocervical glandular neoplasia associated with lobular endocervical glandular hyperplasia is HPV-independent and correlates with carbonic anhydrase-IX expression: a Gynaecological Oncology Group Study.

BackgroundLobular endocervical glandular hyperplasia (LEGH) is a rare lesion of the uterine cervix. It has been proposed that LEGH may represent a precursor lesion to a group of mucinous adenocarcinoma with gastric phenotype (GA) that is independent of high-risk human papillomavirus (H-HPV) infection. Carbonic anhydrase-IX (CA-IX) is highly expressed in conventional glandular lesions (CGLs). However, expression of CA-IX in LEGH or GA has not been studied.MethodsIn all, 12 CGLs, 7 LEGHs, 6 LEGHs with coexisting adenocarcinoma in situ (AIS, 3) and GA (3) were identified from Japanese women with a cytological diagnosis of atypical glandular cells of undetermined significance. Immunostaining was used to detect CA-IX and p16(INK)4(a) (hereafter termed p16) protein expression in the tissues and CA-IX protein expression in the Papanicolaou smears (PSs). Polymerase chain reaction was used to detect H-HPV DNA in liquid-based cytology.ResultsOut of 12 (83%) CGLs, 10 were positive with H-HPV and high levels of CA-IX expression were seen in all (100%) cases. P16 protein expression was observed in 11 out of 12 (92%) cases. None of the LEGHs, LEGHs with AIS or GA were positive for H-HPV and only 8 out of 13 (62%) showed focal weak (1+) p16 expression. In contrast, all cases (100%) exhibited strong CA-IX protein expression.ConclusionOur study suggests that there are different molecular mechanisms of carcinogenesis resulting in CGLs vs LEGHs associated with AIS or GA. There is also a possible link between LEGHs and GAs. Furthermore, CA-IX expression may serve as a useful biomarker for the detection of GAs in the absence of H-HPV infection

Functional investigation of tumor and angiogenesis suppressive candidate tumor suppressor, cysteine-rich intestinal protein 2 in nasopharyngeal carcinoma

Session 8 - Epithelial cells, Infection, Carcinoma: abstract no. 55postprintThe 14th Biennial Symposium of the International Association for Research on Epstein-Barr Virus and Associated Diseases (EBV 2010), Birmingham, U.K., 4-7 September 2010

Short tandem repeat profiling: part of an overall strategy for reducing the frequency of cell misidentification

The role of cell authentication in biomedical science has received considerable attention, especially within the past decade. This quality control attribute is now beginning to be given the emphasis it deserves by granting agencies and by scientific journals. Short tandem repeat (STR) profiling, one of a few DNA profiling technologies now available, is being proposed for routine identification (authentication) of human cell lines, stem cells, and tissues. The advantage of this technique over methods such as isoenzyme analysis, karyotyping, human leukocyte antigen typing, etc., is that STR profiling can establish identity to the individual level, provided that the appropriate number and types of loci are evaluated. To best employ this technology, a standardized protocol and a data-driven, quality-controlled, and publically searchable database will be necessary. This public STR database (currently under development) will enable investigators to rapidly authenticate human-based cultures to the individual from whom the cells were sourced. Use of similar approaches for non-human animal cells will require developing other suitable loci sets. While implementing STR analysis on a more routine basis should significantly reduce the frequency of cell misidentification, additional technologies may be needed as part of an overall authentication paradigm. For instance, isoenzyme analysis, PCR-based DNA amplification, and sequence-based barcoding methods enable rapid confirmation of a cell line’s species of origin while screening against cross-contaminations, especially when the cells present are not recognized by the species-specific STR method. Karyotyping may also be needed as a supporting tool during establishment of an STR database. Finally, good cell culture practices must always remain a major component of any effort to reduce the frequency of cell misidentification

Ectodomain shedding of the hypoxia-induced carbonic anhydrase IX is a metalloprotease-dependent process regulated by TACE/ADAM17

Carbonic anhydrase IX (CA IX) is a transmembrane protein whose expression is strongly induced by hypoxia in a broad spectrum of human tumours. It is a highly active enzyme functionally involved in both pH control and cell adhesion. Its presence in tumours usually indicates poor prognosis. Ectodomain of CA IX is detectable in the culture medium and body fluids of cancer patients, but the mechanism of its shedding has not been thoroughly investigated. Here, we analysed several cell lines with natural and ectopic expression of CA IX to show that its ectodomain release is sensitive to metalloprotease inhibitor batimastat (BB-94) and that hypoxia maintains the normal rate of basal shedding, thus leading to concomitant increase in cell-associated and extracellular CA IX levels. Using CHO-M2 cells defective in shedding, we demonstrated that the basal CA IX ectodomain release does not require a functional TNFα-converting enzyme (TACE/ADAM17), whereas the activation of CA IX shedding by both phorbol-12-myristate-13-acetate and pervanadate is TACE-dependent. Our results suggest that the cleavage of CA IX ectodomain is a regulated process that responds to physiological factors and signal transduction stimuli and may therefore contribute to adaptive changes in the protein composition of tumour cells and their microenvironment

Gene Expression of the Tumour Suppressor LKB1 Is Mediated by Sp1, NF-Y and FOXO Transcription Factors

The serine/threonine kinase LKB1 is a tumour suppressor that regulates multiple biological pathways, including cell cycle control, cell polarity and energy metabolism by direct phosphorylation of 14 different AMP-activated protein kinase (AMPK) family members. Although many downstream targets have been described, the regulation of LKB1 gene expression is still poorly understood. In this study, we performed a functional analysis of the human LKB1 upstream regulatory region. We used 200 base pair deletion constructs of the 5′-flanking region fused to a luciferase reporter to identify the core promoter. It encompasses nucleotides −345 to +52 relative to the transcription start site and coincides with a DNase I hypersensitive site. Based on extensive deletion and substitution mutant analysis of the LKB1 promoter, we identified four cis-acting elements which are critical for transcriptional activation. Using electrophoretic mobility shift assays as well as chromatin immunoprecipitations, we demonstrate that the transcription factors Sp1, NF-Y and two forkhead box O (FOXO) family members FOXO3 and FOXO4 bind to these elements. Overexpression of these factors significantly increased the LKB1 promoter activity. Conversely, small interfering RNAs directed against NF-Y alpha and the two FOXO proteins greatly reduced endogenous LKB1 expression and phosphorylation of LKB1's main substrate AMPK in three different cell lines. Taken together, these results demonstrate that Sp1, NF-Y and FOXO transcription factors are involved in the regulation of LKB1 transcription

Cell fusions in mammals

Cell fusions are important to fertilization, placentation, development of skeletal muscle and bone, calcium homeostasis and the immune defense system. Additionally, cell fusions participate in tissue repair and may be important to cancer development and progression. A large number of factors appear to regulate cell fusions, including receptors and ligands, membrane domain organizing proteins, proteases, signaling molecules and fusogenic proteins forming alpha-helical bundles that bring membranes close together. The syncytin family of proteins represent true fusogens and the founding member, syncytin-1, has been documented to be involved in fusions between placental trophoblasts, between cancer cells and between cancer cells and host cells. We review the literature with emphasis on the syncytin family and propose that syncytins may represent universal fusogens in primates and rodents, which work together with a number of other proteins to regulate the cell fusion machinery