Expression and prognostic significance of THBS1, Cyr61 and CTGF in esophageal squamous cell carcinoma

<p>Abstract</p> <p>Background</p> <p>Thrombospondin1 (THBS1), cystene-rich protein 61 (Cyr61) and connective tissue growth factor (CTGF) are all involved in the transforming growth factor-beta (TGF-β) signal pathway, which plays an important role in the tumorigenesis. The purpose of this study is to explore the expression and prognostic significance of these proteins in esophageal squamous cell carcinoma (ESCC).</p> <p>Methods</p> <p>We used immunohistochemistry and western blotting to examine the expression status of THBS1, Cyr61 and CTGF in ESCC. Correlations of THBS1, Cyr61 and CTGF over-expressions with various clinicopathologic factors were also determined by using the Chi-square test or Fisher's exact probability test. Survival analysis was assessed by the Kaplan-Meier analysis and the log-rank test. Relative risk was evaluated by the multivariate Cox proportional hazards model.</p> <p>Results</p> <p>THBS1, Cyr61 and CTGF were all over-expressed in ESCC. THBS1 over-expression was significantly associated with TNM stage (<it>P </it>= 0.029) and regional lymph node involvement (<it>P </it>= 0.026). Kaplan-Meier survival analysis showed that over-expression of THBS1, Cyr61 or CTGF was related to poor survival of ESCC patients (<it>P </it>= 0.042, <it>P </it>= 0.020, <it>P </it>= 0.018, respectively). Multivariate Cox analysis demonstrated that Cyr61 and CTGF were independent factors in prognosis of ESCC.</p> <p>Conclusion</p> <p>Cyr61, CTGF and THBS1 were all over-expressed in ESCC and might be new molecular markers to predict the prognosis of ESCC patients.</p

The effects of IL-4 and IL-5 on the IgA response by murine Peyer's patch B cell subpopulations.

Abstract IL-5 has been shown to specifically enhance IgA secretion in LPS-stimulated splenic B cell cultures. Maximum enhancement of IgA in such cultures, however, requires IL-4 in addition to IL-5. Because the Peyer's patches (PP), compared with spleen and lymph nodes, are enriched for precursors of IgA-secreting cells, we tested whether IL-4 and IL-5 would have a more profound effect on IgA secretion by polyclonally stimulated PP cells than spleen cells. The combination of IL-4 and IL-5 causes a comparable enhancement of IgA secretion in both LPS-stimulated PP and splenic B cell cultures. The majority of IgA secreted in LPS-stimulated PP cell cultures is derived from the sIgA- population. Furthermore, the binding high level of peanut agglutinin, germinal center subpopulation of PP cells is essentially nonresponsive to LPS, even in the presence of lymphokines; the majority of secreted IgA in these cultures is derived from the binding low level of peanut agglutinin population. In contrast to LPS-stimulated cultures, PP B cells secrete considerably more IgA than splenic B cells when polyclonally stimulated by a clone of autoreactive T cells in the presence of IL-4 and IL-5. The majority of IgA made by T cell-stimulated PP cell cultures is derived from the sIgA+ population. In these cultures, sIgA- PP cells and spleen cells secrete comparable levels of IgA and other non-IgM isotypes suggesting that sIgA- PP B cells are similar to splenic B cells in their potential to switch to IgA. In T cell-stimulated cultures the majority of IgA as well as of all other isotypes is also derived from the nongerminal center, binding low level of peanut agglutinin population.</jats:p

Mechanism for transforming growth factor beta and IL-2 enhancement of IgA expression in lipopolysaccharide-stimulated B cell cultures.

Abstract Transforming growth factor beta (TGF-beta), but not IL-2, causes LPS-stimulated surface (s)IgA- cells to express sIgA. Although there is a progression of sIgA- cells to sIgA+ cells and then to IgA-secreting cells, there is not a parallel change in ratio of membrane to secreted form of alpha-mRNA. In fact, the secreted form of alpha-mRNA is always the predominant form even before the expression of sIgA. However, at least some of the secreted alpha-mRNA transcripts are sterile. The increase in sIgA expression and the induction of sterile transcripts indicate that TGF-beta enhances H chain class switching to IgA as opposed to allowing the growth and maturation of cells precommitted to IgA secretion. The addition of IL-2 to cultures with TGF-beta results in a 5- to 10-fold increase in IgA secretion compared to cultures to which only TGF-beta was added. In these cultures IL-2 increases neither the proportion nor the total number of sIgA+ cells suggesting that IL-2 acts to increase IgA secretion. However, IL-2 does not cause a change in the ratio of secreted to membrane form of alpha-mRNA nor does it lead to an increase in the steady state level of alpha-mRNA comparable to the increase in secreted IgA. Thus, it appears that regulation of transcription of IgA as sIgA- cells proliferate and undergo H class switching and maturation does not follow the same sequence as is seen when sIgM+ cells proliferate and mature to Ig-secreting cells. Furthermore, the data suggest that maturation to high level secretion is controlled posttranscriptionally.</jats:p

Regulation of usage of membrane and secreted 3' termini of alpha mRNA differs from mu mRNA.

Abstract Previous studies demonstrated that the addition of transforming growth factor-beta (TGF-beta) to LPS-stimulated B cell cultures induced cells to express membrane IgA and to mature to IgA-secreting cells without a parallel change in usage of 3' termini by alpha mRNA. In these cultures, the secreted form of alpha mRNA was predominant even before expression of membrane IgA could be detected. In the present study, we demonstrate that the preferential usage of the secreted terminus of alpha mRNA in these cultures is not caused by transcription termination and reflects a difference in the regulation of choice of 3' terminus for alpha and mu mRNA. The addition of TGF-beta to LPS-stimulated cultures causes an increase in the steady state level of alpha mRNA using the secreted 3' terminus. In contrast, TGF-beta decreases the steady state level of mu mRNA and inhibits usage of the 3' terminus for the secreted form of mu, suggesting that the choice of 3' terminus for alpha and mu mRNA is regulated differently in LPS-stimulated cultures. To determine whether the difference in usage of 3' termini by alpha and mu mRNA was a property of the culture system or whether it reflected a difference in regulation, C alpha was transfected into cell lines representing different stages of B cell development. The secreted form of alpha mRNA predominates regardless of the ratio of membrane to secreted forms of the endogenous C mu gene. A similar dichotomy in 3' terminus usage occurred in a stable C alpha transfectant of the BCL1 lymphoma, suggesting that trans-acting factors are not limiting. Furthermore, as was the case with normal B cells, the predominance of the secreted form of the transfected C alpha genes was not due to transcription termination. These data demonstrate that usage of 3' terminus in alpha and mu mRNA is regulated differently.</jats:p

Increase of precursor frequency and clonal size of murine IgE-secreting cells by IL-4.

Abstract IL-4 is able to preferentially enhance murine IgE levels in the supernatant of LPS-stimulated T cell-depleted splenic B cell cultures. Clonal and quantitative analysis of this response revealed that this is due partly to a 14-fold increased IgE precursor frequency and partly to a three-fold increased clone size of IgE-secreting cells. IL-4 increased the precursor frequency and the clone size of IgM-secreting cells not more than twofold. Both the IgM and IgE response in LPS-stimulated B cells were completely inhibited by the addition of anti-IgM mAb (M41) to the cultures, indicating that the IgE-secreting clones developed as subclones from precursors that express IgM. These cells lacked expression of membrane-bound IgE up to day 5 of the culture. Application of feeder cells in these cultures resulted in an increased precursor frequency of IgE-secreting clones among LPS-reactive B cells that is due, partially, to IL-4 produced by the feeder cells.</jats:p