Serglycin Is Involved in TGF-ß Induced Epithelial-Mesenchymal Transition and Is Highly Expressed by Immune Cells in Breast Cancer Tissue.

Serglycin is a proteoglycan highly expressed by immune cells, in which its functions are linked to storage, secretion, transport, and protection of chemokines, proteases, histamine, growth factors, and other bioactive molecules. In recent years, it has been demonstrated that serglycin is also expressed by several other cell types, such as endothelial cells, muscle cells, and multiple types of cancer cells. Here, we show that serglycin expression is upregulated in transforming growth factor beta (TGF-ß) induced epithelial-mesenchymal transition (EMT). Functional studies provide evidence that serglycin plays an important role in the regulation of the transition between the epithelial and mesenchymal phenotypes, and it is a significant EMT marker gene. We further find that serglycin is more expressed by breast cancer cell lines with a mesenchymal phenotype as well as the basal-like subtype of breast cancers. By examining immune staining and single cell sequencing data of breast cancer tissue, we show that serglycin is highly expressed by infiltrating immune cells in breast tumor tissue.

Overexpression of miR-20a-5p in Tumor Epithelium Is an Independent Negative Prognostic Indicator in Prostate Cancer-A Multi-Institutional Study.

OBJECTIVE: assessing the prognostic role of miR-20a-5p, in terms of clinical outcome, in a large multi-institutional cohort study. METHODS: Tissue microarrays from 535 patients' prostatectomy specimens were constructed. In situ hybridization was performed to assess the expression level of miR-20a-5p in different tissue subregions: tumor stroma (TS) and tumor epithelium (TE). In vitro analysis was performed on prostate cancer cell lines. RESULTS: A high miR-20a-5p expression was found negatively in association with biochemical failure in TE, TS and TE + TS (p = 0.001, p = 0.003 and p = 0.001, respectively). Multivariable analysis confirmed that high miR-20a-5p expression in TE independently predicts dismal prognosis for biochemical failure (HR = 1.56, 95% CI: 1.10-2.21, p = 0.014). Both DU145 and PC3 cells exhibited increased migration ability after transient overexpression of miR-20a-5p, as well as significant elevation of invasion in DU145 cells. CONCLUSION: A high miR-20a-5p expression in tumor epithelium is an independent negative predictor for biochemical prostate cancer recurrence.

Expression of insulin-like growth factor mitogenic signals in adult soft-tissue sarcomas: significant correlation with malignant potential.

The insulin-like growth factor (IGF) signal transduction system involves receptors, ligands and binding proteins (IGFBPs) that have been shown to have mitogenic and distinct anti-apoptotic effects on malignant cell lines of both epithelial and mesenchymal origin. Expression of the IGF signal system might be a mechanism by which human soft-tissue sarcomas (STS) obtain a proliferative advantage over normal adjacent tissues. IGFBP2, one of at least six different binding proteins identified to date, is secreted by most sarcoma cell lines and appears to be involved in cell proliferation and transformation. Circulating levels of this protein are markedly increased in malignancy. We have assessed 46 adult STS specimens of low, intermediate and high pathological grade of malignancy for the immunohistochemical expression of IGFBP2, IGF1, IGF2, IGF1 receptor-alpha and -beta (IGF1Ralpha/beta). The protein expression was measured by quantitative color video image analysis and semi-quantitative evaluation, and the measurements correlated well (Spearman, P<0.001). Using both methods, significant differences in expression of IGFBP2 among each of the three grades, expression of IGF2 between intermediate and high grade, and expression of IGF1Rbeta between low-intermediate and low-high grade were observed (Dunnett test, P<0.05). Multiple regression analysis for both quantitative and semi-quantitative data confirmed the significance of the relationship and independence of the proteins, except IGF2. We concluded that IGFBP2 and IGF1Rbeta are independent predictors of the malignant potential of adult STS.

Expression of nm23 protein in adult soft tissue sarcoma is correlated with histological grade.

BACKGROUND: There is controversy about whether expression of nm23 is involved in suppression of metastases or contributes to tumour progression. Few studies have examined the role of nm23 in sarcomas. The aim of this study was to determine if expression of nm23 protein or its H1-subtype correlated with clinicopathological parameters in adult soft tissue sarcomas (STS). MATERIALS AND METHODS: Protein expression was examined by immunohistochemistry on paraffin-embedded sections of 46 STS patients, quantified using a colour video imaging system and correlated to histological grade. The monoclonal antibodies used were anti-nm23 (recognising both nm23-H1 and nm23-H2) and anti-nm23-H1 (recognising nm23-H1 only). RESULTS: High-grade tumours significantly overexpressed nm23 (including both nm23-H1 and nm23-H2) compared with both intermediate and low-grade tumours (ANOVA and Tukey, all p < 0.05). Multiple regression analysis confirmed the significance of the relationship and independence of the nm23 (p = 0.005), but not nm23-H1. CONCLUSION: Expression of nm23 protein, particularly nm23-H2, is an independent predictor of malignant potential of adult STS.

Spontaneously formed tumorigenic hybrids of Meth A sarcoma cells and macrophages in vivo.

We have recently demonstrated that malignant cells can hybridize with tissue macrophages in vitro, giving rise to tumorigenic hybrids. We now demonstrate that this can occur spontaneously in vivo as a result of fusion between inoculated Meth A sarcoma cells and host cells, presumably macrophages. Thus, from tumor cell suspensions prepared by collagenase perfusion and density centrifugation, hybrid cells could be isolated that were neoplastic but in contrast to Meth A expressed macrophage markers and had phagocytic capacity. Their morphologic features were intermediate between Meth A and macrophages. By taking advantage of a semiallogeneic experimental system by inoculation of Meth A cells from BALB/c (H-2 K(d)) into (BALB.K x BALB/c) F(1) (H-2(k/d)), hybrid cells from these tumors could be shown to express MHC antigens of both the Meth A and the host haplotypes. Hybrid cells grew faster than Meth A cells in vivo, indicating acquisition of growth-promoting properties through heterotypic cell fusion.

Spontaneously formed tumorigenic hybrids of Meth A sarcoma and macrophages grow faster and are better vascularized than the parental tumor.

Macrophages and Meth A sarcoma cells spontaneously fuse and give rise to tumorigenic hybrid cell lines with a mixed phenotype. We report here that the hybrid tumors grow faster and have a strikingly better developed vasculature than the parent sarcoma. Thus, electron microscopy and immunohistochemical analysis revealed that in the most active areas of neovascularization, the tumors that emerged from inocula of monoclonal hybrid cell populations had a microvessel density nearly twice that of Meth A tumors after 1 week of growth. Moreover, the proportion of vessels associated with pericytes, detected by staining for smooth muscle alpha-actin, was 3 times higher in the hybrid tumors, attesting to the more advanced differentiation of their vasculature. The collagenous stroma component was also more extensive in the hybrid tumors. Concentration of the angiogenic proteins vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-beta) were significantly higher in supernatants of hybrid cell cultures compared with Meth A cultures. These observations indicate that the growth advantage of the hybrid tumors over the parental sarcoma is due to a higher angiogenic capacity. Because the malignant features of many tumors correlate with angiogenesis and because macrophages are known to be major producers of angiogenic factors, our data open the possibility that the intense neovascularization of highly aggressive cancers in some cases reflects the acquisition of macrophage traits by heterotypic cell fusion.

Spontaneous hybridization of macrophages and Meth A sarcoma cells.

We present evidence of hybridization between Meth A sarcoma cells and syngeneic as well as semigeneic peritoneal macrophages. The resultant hybrids are characterized by morphology, membrane markers, ploidy, chromosomal content and functional features. Briefly, after a few days of coculture, cells appeared with morphology intermediate between the 2 original cell types. Typical macrophage surface molecules appeared in the hybrids. Meth A cells were labeled with red fluorescence and macrophages with green fluorescence. After 4 days in vitro, hybrids with yellow fluorescence appeared. Macrophages from BALB.K mice (H-2 K(k)) were cocultivated with Meth A cells from BALB/c mice (H-2 K(d)). The semigeneic hybrids displayed both specificities, as demonstrated by flow cytometry. The hybrids appeared moderately phagocytic, less so than the macrophages and markedly more so than the essentially nonphagocytic Meth A cells. The hybrids had a mean number of 76 chromosomes, as opposed to 53 in the Meth A cells and 40 in the macrophages. The macrophage DNA index was set at 1; Meth A cells were found to have an index of 1.6 in G1 phase, and the hybrids had a 2.6 index. The hybrids grew more slowly in vitro than Meth A cells, but grew faster in vivo.