Homotypic Adhesion through Carcinoembryonic Antigen Plays a Role in Hepatic Metastasis Development

We established a cell line with high metastatic potential to the liver (LS-LM4) after four successive repetitions of splenic injection of liver-metastatic cells in SCID mice. This cell line strongly expressed CEA and showed increased homotypic adhesion as compared with the parent cell line (LS174T). To examine the role of CEA in the increased homotypic adhesion, LS-LM4 cells were treated with anti-CEA antibody and subjected to an in vitro adhesion and aggregation assay. Further, to study the role of CEA in the hepatic metastasis of cells with high metastatic potential, LS-LM4 cells were treated with anti-CEA antibody, and the inhibition of hepatic metastasis after splenic injection in vivo was examined. There was a 62% decrease in the homotypic adhesion of anti-CEA antibody-treated (100 μg/ml) LS-LM4 cells under a Ca²⁺-free condition as compared with the control ( P <0.01). Anti-CEA antibody (100 μg/ml) inhibited cell aggregation under a Ca²⁺-free condition ( P <0.05). Treatment with anti-E-cadherin antibody (60 μ/ml) plus anti-CEA antibody (100 μg/ml) inhibited cell aggregation more potently than anti-E-cadherin antibody treatment alone in the presence of Ca²⁺. In vivo , there was a 75% decrease in the number of hepatic metastatic nodules in the G125 anti-CEA antibody-treated group as compared with the control group ( P <0.01). Similarly, there was a 40% decrease in the diameter of metastatic nodules and there was a 90% decrease in total tumor volume of hepatic metastasis in the G125 anti-CEA antibody-treated group as compared with the control ( P <0.01). These results suggest that increased metastatic potential to the liver is at least partly due to increased homotypic binding mediated by CEA.     

Down-regulation of LATS1 and LATS2 mRNA expression by promoter hypermethylation and its association with biologically aggressive phenotype in human breast cancers.

PURPOSE: LATS1 and LATS2 are tumor suppressor genes implicated in the regulation of cell cycle. Methylation status of the promoter regions of these genes as well as its correlation with their mRNA levels were studied in human breast cancers. Correlation of LATS1 and LATS2 mRNA levels with clinicopathologic characteristics of breast tumors were also studied. EXPERIMENTAL DESIGN: Methylation status of promoter regions of LATS1 and LATS2 was studied by a methylation-specific PCR and mRNA expression levels of LATS1 and LATS2 were determined by a real-time PCR assay in 30 breast cancers. In addition, correlation of LATS1 and LATS2 mRNA levels with clinicopathologic characteristics was studied in 117 breast cancers. RESULTS: Methylation-specific PCR showed that of 30 tumors, LATS1 promoter region was hypermethylated in 17 tumors (56.7%) and LATS2 promoter region was hypermethylated in 15 (50.0%) tumors. LATS1 mRNA levels in breast tumors with hypermethylation (2.15 +/- 0.37, mean +/- SE) were significantly (P < 0.01) lower than those without hypermethylation (6.09 +/- 1.38), and LATS2 mRNA levels in breast tumors with hypermethylation (1.42 +/- 0.66) were also significantly (P < 0.01) lower than those without hypermethylation (3.10 +/- 1.00). The decreased expression of LATS1 or LATS2 mRNA was significantly associated with a large tumor size, high lymph node metastasis, and estrogen receptor and progesterone receptor negativity. Furthermore, the decreased expression of LATS1 mRNA, but not LATS2 mRNA, was significantly (P < 0.05) associated with a poor prognosis. CONCLUSIONS: Hypermethylation of the promoter regions of LATS1 and LATS2 likely plays an important role in the down-regulation of their mRNA levels in breast cancers, and breast cancers with a decreased expression of LATS1 or LATS2 mRNA levels have a biologically aggressive phenotype.     

Naja melanoleuca cobra venom contains two forms of complement-depleting factor (CVF)

Two forms of complement-depleting cobra venom factor (CVFm1 and CVFm2), possessing molecular masses of 142.6 kDa (CVFm1) and 143.1 kDa (CVFm2), according to MALDI mass-spectrometry, were isolated from the Naja melanoleuca cobra venom. As shown by polyacrylamide gel electrophoresis in the presence of SDS, both forms similarly to factor from the Naja kaouthia cobra venom (CVFk) consist of three polypeptide chains with molecular masses of about 70, 50, and 30 kDa, the two large subunits being glycosylated. As determined by MALDI mass-spectrometry, 30 kDa subunits of CVFm1 and CVFm2 have considerably different finger-prints of tryptic digests that suggests differences in their amino acid sequences. A study of activity in vivo has shown no significant differences in C3 consumption by CVFm1, CVFm2 and CVFk in mouse blood. However, as shown by an immunoassay method, they differ in their ability to activate the complement system via C3 conversion, the ratio of these activities for CVFm1:CVFm2:CVFk being 2.5:1.6:1. Kinetic studies using a hemolytic test showed that complement depletion by CVFm1 is faster than that by CVFm2. Thus, for the first time the presence in a single venom of two forms of CVF differing by both amino acid sequence and biological activity has been shown.     

Coat color DNA testing in dogs: Theory meets practice

DNA tests to detect particular dog coat color alleles are in use in several DNA diagnostic laboratories. The original two genes studied were MC1R and TYRP1 and therefore these tests have been used most widely, and for the longest period of time. The original research was conducted to determine the mutation associated with a particular phenotype in one to a few dog breeds, and was subsequently expanded to include more dog breeds. The application of this testing now includes an even wider range of dog breeds, some of which would not have been expected to have some of the alleles detected. This retrospective study demonstrates that a DNA test may be designed for a particular application, but is used by clients for additional applications that were not originally anticipated. A robust protocol with DNA obtained by cheek brushes and interchanges among dog owners via the internet, have likely lead to this expanded use by clients.     

Self-rated Physical,Mental, Oral,and Cognitive Health in Older Korean Immigrants: The Role of Health Indicators and Sociocultural Factors

Journal of Immigrant and Minority Health - Guided by the models of health assessment and social determinants of health, we examined predictors of self-rated physical, mental, oral, and cognitive...