Thymosin ß4 expression in colorectal polyps and adenomas.

OBJECTIVE: Thymosin beta 4 (Tß4) is a ubiquitous peptide that plays pivotal roles in the cytoskeletal system and in cell differentiation. Recently, a role for Tß4 has been proposed in experimental and human carcinogenesis, including gastrointestinal cancer. This study was aimed at evaluating the relationship between Tß4 immunoreactivity and the initial steps of carcinogenesis. METHODS: In total, 60 intestinal biopsies, including 10 hyperplastic polyps, 10 sessile serrated adenomas/polyps, 15 colorectal adenomas with low-grade dysplasia, 15 adenomas with high-grade dysplasia, 15 adenocarcinomas and 10 samples of normal colon mucosa, were analyzed for Tß4 expression by immunohistochemistry. RESULTS: Weak cytoplasmic reactivity for Tß4 was detected in the normal colon mucosa. No reactivity for Tß4 was found in hyperplastic and sessile serrated polyps/adenomas. Tß4 expression was observed in 10/15 colorectal adenocarcinomas. In adenomas with low-grade dysplasia, Tß4 immunoreactivity was mainly detected in dysplastic glands but was absent in hyperplastic glands. Tß4 immunoreactivity was characterized by spot-like perinuclear staining. In high-grade dysplastic polyps, immunostaining for Tß4 appeared diffuse throughout the entire cytoplasm of dysplastic cells. Spot-like perinuclear reactivity was detected in adenocarcinoma tumor cells. CONCLUSIONS: Our study shows for the first time that Tß4 is expressed during different steps of colon carcinogenesis. The shift of Tß4 immunolocalization from low-grade to high-grade dysplastic glands suggests a role for Tß4 in colorectal carcinogenesis. However, the real meaning of Tß4 reactivity in dysplastic intestinal epithelium remains unknown.

Thymosin ß4 expression in colorectal polyps and adenomas

OBJECTIVE: Thymosin beta 4 (Tβ4) is a ubiquitous peptide that plays pivotal roles in the cytoskeletal system and in cell differentiation. Recently, a role for Tβ4 has been proposed in experimental and human carcinogenesis, including gastrointestinal cancer. This study was aimed at evaluating the relationship between Tβ4 immunoreactivity and the initial steps of carcinogenesis. METHODS: In total, 60 intestinal biopsies, including 10 hyperplastic polyps, 10 sessile serrated adenomas/polyps, 15 colorectal adenomas with low-grade dysplasia, 15 adenomas with high-grade dysplasia, 15 adenocarcinomas and 10 samples of normal colon mucosa, were analyzed for Tβ4 expression by immunohistochemistry. RESULTS: Weak cytoplasmic reactivity for Tβ4 was detected in the normal colon mucosa. No reactivity for Tβ4 was found in hyperplastic and sessile serrated polyps/adenomas. Tβ4 expression was observed in 10/15 colorectal adenocarcinomas. In adenomas with low-grade dysplasia, Tβ4 immunoreactivity was mainly detected in dysplastic glands but was absent in hyperplastic glands. Tβ4 immunoreactivity was characterized by spot-like perinuclear staining. In high-grade dysplastic polyps, immunostaining for Tβ4 appeared diffuse throughout the entire cytoplasm of dysplastic cells. Spot-like perinuclear reactivity was detected in adenocarcinoma tumor cells. CONCLUSIONS: Our study shows for the first time that Tβ4 is expressed during different steps of colon carcinogenesis. The shift of Tβ4 immunolocalization from low-grade to high-grade dysplastic glands suggests a role for Tβ4 in colorectal carcinogenesis. However, the real meaning of Tβ4 reactivity in dysplastic intestinal epithelium remains unknown. .

Cellular trafficking of thymosin beta-4 in HEPG2 cells following serum starvation.

Thymosin beta-4 (Tß4) is an ubiquitous multi-functional regenerative peptide, related to many critical biological processes, with a dynamic and flexible conformation which may influence its functions and its subcellular distribution. For these reasons, the intracellular localization and trafficking of Tß4 is still not completely defined and is still under investigation in in vivo as well as in vitro studies. In the current study we used HepG2 cells, a human hepatoma cell line; cells growing in normal conditions with fetal bovine serum expressed high levels of Tß4, restricted to the cytoplasm until 72 h. At 84 h, a diffuse Tß4 cytoplasmic immunostaining shifted to a focal perinuclear and nuclear reactivity. In the absence of serum, nuclear reactivity was localized in small granules, evenly dispersed throughout the entire nuclear envelop, and was observed as earlier as at 48 h. Cytoplasmic immunostaining for Tß4 in HepG2 cells under starvation appeared significantly lower at 48 h and decreased progressively at 72 and at 84 h. At these time points, the decrease in cytoplasmic staining was associated with a progressive increase in nuclear reactivity, suggesting a possible translocation of the peptide from the cytoplasm to the nuclear membrane. The normal immunocytochemical pattern was restored when culture cells submitted to starvation for 84 h received a new complete medium for 48 h. Mass spectrometry analysis, performed on the nuclear and cytosolic fractions of HepG2 growing with and without serum, showed that Tß4 was detectable only in the cytosolic and not in the intranuclear fraction. These data suggest that Tß4 is able to translocate from different cytoplasmic domains to the nuclear membrane and back, based on different stress conditions within the cell. The punctuate pattern of nuclear Tß4 immunostaining associated with Tß4 absence in the nucleoplasm suggest that this peptide might be localized in the nuclear pores, where it could regulate the pore permeability.

Asthma symptoms, lung function, and markers of oxidative stress and inflammation in children exposed to oil refinery pollution.

OBJECTIVES: Little is known about the effects of exposure to petroleum refinery emissions on respiratory health in children. We evaluated lung function and markers of inflammation and oxidative stress in children and adolescents with and without asthma or wheezing symptoms living in a petrochemical polluted area (Sarroch, Sardinia) versus a reference area (Burcei). METHODS: Parents of 275/300 6- to 14-year-old children living in Sarroch and parents of 214/323 children living in Burcei answered a questionnaire on respiratory symptoms and risk factors. Measurements of forced expiratory volume after 1 second (FEV(1)) and of forced expiratory flow rates at 25-75% of vital capacity (FEF(25-75)) were available in 27 and 23 asthma/wheezing-positive subjects and in 7 and 54 asthma/wheezing-negative subjects in Sarroch and in Burcei, respectively; for fractional exhaled nitric oxide (FE(NO)) corresponding figures were 27 and 24 and 8 and 55 in Sarroch and in Burcei, respectively. Malondialdehyde-deoxyguanosine (MDA-dG) adduct levels in nasal mucosa were measured in 12- to 14-year-old adolescents (8 and 14 asthma/wheezing-positive and 20 and 28 asthma/wheezing-negative subjects in Sarroch and in Burcei, respectively). Air pollutants were assessed during 3 weeks, starting 1 week before lung function, FE(NO), and MDA-dG measurements. Generalized linear models were used to estimate the effect of the area of residence adjusting for confounders. RESULTS: Weekly average concentrations of sulfur dioxide were 6.9-61.6 µg/m(3) in Sarroch versus 0.3-7.6 µg/m(3) in the rural area of Burcei; of nitrogen dioxide, 5.2-28.7 µg/m(3) versus 1.7-5.3 µg/m(3); and of benzene, 1.8-9.0 µg/m(3) versus 1.3-1.5 µg/m(3), respectively. Children living in Sarroch versus children living in the reference area showed an increase in wheezing symptoms {adjusted prevalence ratio=1.70 [90% confidence interval (CI)=1.01; 2.86]}; a decrease in lung function [variation in FEV(1)=-10.3% (90% CI=-15.0; -6.0%) and in FEF(25-75)=-12.9% (90% CI=-20.7; -4.3%)]; an increase in bronchial inflammation [variation in FE(NO)=+35% (90% CI=11.7; 80.1%)]; and an increase in MDA-dG adducts of +83% (90% CI=22.9; 174.1%). CONCLUSIONS: Data from this small study are consistent with the role of environmental pollutants on lung function and inflammation.

Thymosin beta(4) and beta(10) levels in pre-term newborn oral cavity and foetal salivary glands evidence a switch of secretion during foetal development.

BACKGROUND: Thymosin beta(4), its sulfoxide, and thymosin beta(10) were detected in whole saliva of human pre-term newborns by reversed-phase high performance chromatography coupled to electrospray ion-trap mass spectrometry. METHODOLOGY/PRINCIPAL FINDINGS: Despite high inter-individual variability, concentration of beta-thymosins increases with an inversely proportional trend to postmenstrual age (PMA: gestational age plus chronological age after birth) reaching a value more than twenty times higher than in adult whole saliva at 190 days (27 weeks) of PMA (thymosin beta(4) concentration: more than 2.0 micromol/L versus 0.1 micromol/L). On the other hand, the ratio between thymosin beta(4) and thymosin beta(10) exhibits a constant value of about 4 along all the range of PMA (190-550 days of PMA) examined. In order to investigate thymosin beta(4) origin and to better establish the trend of its production as a function of gestational age (GA), immunohistochemical analysis of major and minor salivary glands of different pre-term fetuses were carried out, starting from 84 days (12 weeks) of gestational age. Reactive granules were seen in all glands with a maximum of expression around 140-150 days of GA, even though with high inter- and intra-individual variability. In infants and adults reactive granules in acinar cells were not observed, but just a diffuse cytoplasmatic staining in ductal cells. SIGNIFICANCE: This study outlines for the first time that salivary glands during foetal life express and secrete peptides such as beta-thymosins probably involved in the development of the oral cavity and its annexes. The secretion increases from about 12 weeks till to about 21 weeks of GA, subsequently it decreases, almost disappearing in the period of expected date of delivery, when the gland switches towards the secretion of adult specific salivary peptides. The switch observed may be an example of further secretion switches involving other exocrine and endocrine glands during foetal development.

Hepatocyte Paraffin 1 Immunoreactivity in Early Colon Carcinogenesis.

BACKGROUND: This study was aimed at evaluating the correlation between Hepatocyte paraffin 1 (Hep par 1) and colorectal cancer. METHODS: To this end, 50 intestinal biopsies were analyzed including 10 colorectal polyps with low grade dysplasia, 10 with high grade dysplasia, 10 colorectal adenocarcinomas, 10 specimens of normal ileum and 10 of normal colon mucosa. Tissue sections were immunostained for Hep par 1 utilizing a commercial antibody. Normal colonic mucosa did not express Hep par 1. RESULTS: Immunoreactivity for Hep par 1 was detected in 20% of polyps with low grade dysplasia, 50% of polyps with high grade dysplasia and 60% of colorectal carcinomas. Hep par 1 was frequently detected in the deepest areas of adenocarcinomas mainly in infiltrating tumour cells. CONCLUSIONS: Our data show that Hep par 1 immunoreactivity in human colon carcinogenesis is correlated with progression from low grade to high grade dysplasia and adenocarcinoma. In clinical practice, our data show that caution should be taken in utilizing Hep par 1 as the sole tool in differentiating hepatocellular carcinoma from a liver metastasis of colon adenocarcinoma. Our data encourage further investigations into the potential role played by Hep par 1 in gastrointestinal carcinogenesis.