Maspin is involved in bone matrix maturation by enhancing the accumulation of latent TGF-beta

FOXA2 suppresses gallbladder carcinoma cell migration, invasion, and epithelial-mesenchymal transition by targeting SERPINB5

BACKGROUND

Gallbladder cancer (GBC), a highly malignant gastrointestinal tumor, lacks effective therapies. Foxhead box A2 (FOXA2) is a tumor suppressor that is poorly expressed in various human malignancies. This study aimed to ascertain FOXA2 expression in GBC and its relevance to tumor metastasis, and to elucidate its regulatory mechanism with epithelial-mesenchymal transition (EMT) as an entry point, in the hope of providing a potential therapeutic target for GBC.

METHODS

FOXA2 expression in GBC tissues was first detected using immunohistochemistry (IHC), followed by correlation analysis with clinicopathological characteristics and survival prognosis. Subsequently, the effects of FOXA2 on GBC cell migration and invasion, as well as EMT induction, were evaluated by scratch, Transwell, RT-PCR, and Western blot assays, together with animal experimentation. Ultimately, mRNA sequencing was carried out to identify the key downstream target genes of FOXA2 in controlling the EMT process in GBC cells, and dual-luciferase reporter and chromatin immunoprecipitation assays were used to determine its regulatory mechanism.

RESULTS

FOXA2 was underexpressed in GBC tissues and inversely correlated with tumor node metastasis stage, lymph node metastasis, and poor patient prognosis. FOXA2 exerts suppressive effects on EMT and metastasis of GBC in vivo and in vitro. FOXA2 can impede GBC cell migratory and invasive functions and EMT by positively mediating serine protein kinase inhibitor B5 (SERPINB5) expression.

CONCLUSION

FOXA2 directly binds to the SERPINB5 promoter region to stimulate its transcription, thereby modulating the migration and invasion behaviors of GBC cells as well as the EMT process, which might be an effective therapeutic target against GBC.

Cytoplasmic maspin expression predicts poor prognosis of patients with soft tissue sarcomas

BACKGROUND

Maspin is a 42 kDa protein known to act as a tumor suppressor. Although its function has not been fully elucidated, numerous reports have investigated the prognostic impact of maspin in patients with several types of cancer. However, there have been no reports on the association between maspin expression and the prognosis of patients with soft tissue sarcomas (STS). The aim of this study was thus to explore the association of maspin expression with the prognosis of patients with STS.

METHODS

One-hundred and eight paraffin-embedded STS tissue samples were immunohistochemically analyzed using antibodies for maspin and Ki-67 antigen. The patients were followed up for 1 to 300 months (median: 33 months) and the prognostic value was evaluated by log-rank test and Cox's regression hazard model.

RESULTS

Cytoplasmic maspin expression was observed in 48.1% of specimens, and was significantly correlated with a higher FNCLCC grade (P = 0.002) and the presence of distant metastases (P = 0.001), and those with cytoplasmic maspin expression had both shorter disease-free survival (DFS) and overall survival (OS) by log-rank test (P <0.001, P = 0.001, respectively). By Cox's multivariate analysis, the presence of distant metastases was the only prognostic factor for DFS and OS.

CONCLUSIONS

This is the first report to reveal an association between maspin expression and the prognosis of patients with STS. Although further studies with a larger series of patients and a longer follow-up period will be needed, cytoplasmic maspin expression could be an indicator of unfavorable prognosis in patients with STS.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_205.

Functional inactivation of CYLD promotes the metastatic potential of tumor epidermal cells

CYLD is a tumor-suppressor gene mutated in the skin appendage tumors cylindromas, trichoepitheliomas, and spiradenomas. We have performed in vivo metastasis assays in nude mice and found that the loss of the deubiquitinase function of CYLD in squamous cell carcinoma (SCC) cells greatly enhances the lung metastatic capability of these cells. These metastases showed several characteristics that make them distinguishable from those carrying a functional CYLD, such as robust angiogenesis, increased expression of tumor malignancy markers of SCCs, and a decrease in the expression of the suppressor of metastasis Maspin. Restoration of Maspin expression in the epidermal SCC cells defective in CYLD deubiquitination function significantly reduces their ability to form metastases, thereby suggesting that the decrease in the levels of Maspin expression plays an important role in the acquisition of metastatic potential of these cells. In addition, we have characterized Maspin downregulation in cylindromas, trichoepitheliomas, and spiradenomas carrying functional inactivating mutations of CYLD, also providing an evidence of the correlation between impaired CYLD function and Maspin decreased expression in vivo in human tumors.

Differential response to intracellular stress in the skin from osteogenesis imperfecta Brtl mice with lethal and non lethal phenotype: a proteomic approach

Phenotypic variability in the presence of an identical molecular defect is a recurrent feature in heritable disorders and it was also reported in osteogenesis imperfecta (OI). OI is a prototype for skeletal dysplasias mainly caused by mutations in the two genes coding for type I collagen. No definitive cure is available for this disorder, but the understanding of molecular basis in OI phenotypic modulation will have a pivotal role in identifying possible targets to develop novel drug therapy. We used a functional proteomic approach to address the study of phenotypic variability using the skin of the OI murine model Brtl. Brtl mice reproduce the molecular defect, dominant transmission and phenotypic variability of human OI patients. In the presence of a Gly349Cys substitution in α1(I)-collagen Brtl mice can have a lethal or a moderately severe outcome. Differential expression of chaperones, proteasomal subunits, metabolic enzymes, and proteins related to cellular fate demonstrated that a different ability to adapt to cellular stress distinguished mutant from wild-type mice and mutant lethal from surviving mutant animals. Interestingly, class discovery analysis identified clusters of differentially expressed proteins associated with a specific outcome, and functional analysis contributed to a deeper investigation into biochemical and cellular pathways affected by the disease. This article is part of a Special Issue entitled: Translational Proteomics.

Histochemistry and cell biology: the annual review 2010

This review summarizes recent advances in histochemistry and cell biology which complement and extend our knowledge regarding various aspects of protein functions, cell and tissue biology, employing appropriate in vivo model systems in conjunction with established and novel approaches. In this context several non-expected results and discoveries were obtained which paved the way of research into new directions. Once the reader embarks on reading this review, it quickly becomes quite obvious that the studies contribute not only to a better understanding of fundamental biological processes but also provide use-oriented aspects that can be derived therefrom.

Possible involvement of maspin in tooth development

Maspin is a 42 kDa serine protease inhibitor that possesses tumor suppressive and anti-angiogenic activities. Despite of a huge amount of data concerning the expression pattern of maspin in various tissues and its relevance to the biological properties of a variety of human cancer cells, little is known on the maspin expression in skeletal and tooth tissues. Recently, we reported that maspin may play an important role in extracellular matrix formation in bone by enhancing the accumulation of latent TGF-β in the extracellular matrix. This study was performed to elucidate the possible role of maspin in tooth development. First, an immunohistochemical analysis for human tooth germs at the late bell stage showed the expression of maspin by active ameloblasts and odontoblasts that were forming enamel and dentin, respectively. During rat tooth development, maspin expression was observed for the first time in inner and outer enamel epithelial cells and dental papilla cells at early bell stage. The neutralizing anti-maspin antibody inhibited the proper dental tissue formation in organ cultures of mandibular first molars obtained from 21-day-old rat embryos. In addition, the proliferation of HAT-7 cells, a rat odontogenic epithelial cell line, and human dental papilla cells were suppressed in a dose-dependent manner with anti-maspin antibody. Moreover, RT-PCR analysis showed that the expression of mRNA for tooth-related genes including dentin matrix protein 1, dentin sialophosphoprotein and osteopontin in human dental papilla cells was inhibited when treated with anti-maspin antibody. These findings suggest that maspin expressed in ameloblasts and odontoblasts plays an important physiological role in tooth development through the regulation of matrix formation in dental tissues.