Biomedical subjects

M Caggana

Publications and source records attributed to M Caggana.

22 records · Page 2Linked to original sources

PubMed1989

c-fos mRNA levels are reduced in the presence of antipain and Bowman-Birk inhibitor.

We have studied whether the Bowman-Birk protease inhibitor (BBI) could affect the expression of c-fos in BALB/c/3T3 cells stimulated to divide with serum. Our results show that the levels of c-fos message are significantly decreased in the presence of antipain and BBI. When the cells were treated with cycloheximide after being grown in the presence of BBI, there was no significant decrease in mRNA levels. Our experiments suggest that a BBI-inhibitable protease may be necessary for c-fos expression in 3T3 cells and that new protein synthesis is required for this hypothesized protease to be active. As BBI is capable of affecting c-fos gene expression in cells without being present in the nucleus, our results suggest that a novel pathway could be involved in c-fos gene expression.

Animals↗

PubMed1987

Proteases occurring in the cell membrane: a possible cell receptor for the Bowman-Birk type of protease inhibitors.

The legume-derived Bowman-Birk trypsin and chymotrypsin protease inhibitors (BBI) are effective anticarcinogens in vivo and in vitro. The chymotrypsin-inhibitory domain has been shown to be responsible for this anticarcinogenic action. In this study we identify hydrolytic enzymes by their ability to hydrolyze the relatively specific chymotrypsin substrate succinyl-Ala-Ala-Pro-Phe-aminomethyl coumarin. Results presented in this study show: there is an approximately 2-fold increase in the activity of these enzyme(s) between normal and transformed C3H/10T1/2 cells; there are five such enzymes associated with transformed cells (separated by diethylaminoethyl-cellulose chromatography); only two of these enzymes are inhibited by BBI; the BBI-inhibitable enzymes are membrane associated; the BBI-inhibitable enzymes are similar to each other but different from pancreatic chymotrypsin. BBI has thus distinguished a subpopulation of enzymes capable of hydrolyzing succinyl-Ala-Ala-Pro-Phe-aminomethyl coumarin which may mediate the transformation of C3H/10T1/2 cells.

Cell Line↗

PubMedDate not supplied

Population-based studies reveal differences in the allelic frequencies of two functionally significant human interleukin-4 receptor polymorphisms in several ethnic groups.

PURPOSE: The presence of functionally significant human interleukin-4 receptor sequence variants, Gln551Arg and Ile50Val, was examined in four anonymous New York State populations defined by ethnic origin. These variants were studied because they are associated with atopy or atopic asthma whose prevalence varies in different populations. METHODS: PCR/RFLP (Ile50Val) and PCR/allele-specific oligonucleotide hybridization (Gln551Arg) assays were developed to detect both polymorphisms in 855 newborn screening specimens. RESULTS: Arg551 was most frequently found in Blacks (allele frequency of 68%). However, the Ile50 allele was most common in Whites (allele frequency, 87%). Significantly more Blacks had chromosomes bearing both of the "enhanced signaling" variants (Ile50/Arg551). CONCLUSIONS: Enhanced IL-4R signaling is associated with increased IgE production (atopy). Therefore, our data suggest that the African American population may be at increased risk for diseases, including asthma, which are associated with atopy. These data also emphasize the importance of determining the frequencies of single nucleotide polymorphisms in different populations before drawing conclusions from allele association studies, since the background allele frequencies may be disparate between different populations.

Alleles↗

PubMedDate not supplied

A prospective study of hprt mutant and mutation frequencies in treated cancer patients.

We previously reported that some Hodgkin's disease patients had elevated hprt mutant frequencies in peripheral blood lymphocytes long after cessation of therapy. To determine if these elevations in mutant frequency represent true persistently elevated mutation frequencies, we recruited for a prospective study six previously treated Hodgkin's disease patients and five patients who had been treated for squamous cell carcinoma of the head and neck. These individuals were studied several times over a 6-7-month period. The results confirmed that a subset of patients have persistently high mutant frequencies when compared to 71 previously studied controls. The present study was designed to determine if the elevated mutant frequencies of treated patients represented independent mutations or resulted from the in vivo expansion of single mutant cells. We used the polymerase chain reaction to examine DNA single-strand conformation polymorphisms at the T-cell receptor gamma locus of individual mutant clones. This analysis showed that at any given time 20.1% of the mutants from Hodgkin's disease patients and 17.5% of the mutants from squamous cell carcinoma patients consisted of siblings, identified as having identical polymerase chain reaction/single-stranded conformation polymorphism patterns. The remaining mutants had unique polymerase chain reaction/single-stranded conformation polymorphism patterns and therefore can be presumed to have arisen from independent mutational events. Particular sibling mutants generally did not persist over time. However, one patient had one mutant clone which persisted but slowly decreased in prevalence over a 7-month sampling period. The data demonstrate that treatments for cancer result in persistently elevated mutation frequencies at the hprt locus in some, but not all, patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗