Decline in the expression of the serine proteinase inhibitor maspin is associated with tumour progression in ductal carcinomas of the breast

SERPINB5 promotes colorectal cancer invasion and migration by promoting EMT and angiogenesis via the TNF-α/NF-κB pathway

This study aimed to investigate the role of SERPINB5 in colorectal cancer (CRC). We established knockdown and overexpression models of SERPINB5 in CRC cells and conducted bioinformatics analysis to assess the clinicopathological significance of SERPINB5 expression in CRC patients. Human CRC cells were transfected with LV-SERPINB5 and sh-SERPINB5 lentivirus for subsequent functional and mechanistic studies. Results showed that high SERPINB5 expression correlated positively with CEA levels, N stage and lymphatic infiltration, while displaying a negative correlation with progression-free survival. Overexpression of SERPINB5 in CRC cells upregulated the expression of TNF-α, p-NF-κB/p65, N-cadherin, MMP2 and MMP9, accompanied by decreased E-cadherin expression. In addition, SERPINB5 overexpression enhanced the migration, invasion, and proliferation of CRC cells. Furthermore, overexpression of SERPINB5 in CRC cells increased VEGFA expression, and the conditioned medium from SERPINB5-overexpressing CRC cells promoted tube formation of HUVECs. Conversely, overexpression of SERPINB5 in HUVECs decreased VEGFA expression and inhibited tube formation. Notably, these changes in CRC cells were reversed by QNZ, a specific inhibitor of the TNF-α/NF-κB pathway. In summary, our findings revealed that high SERPINB5 expression correlated with poor progression-free survival in CRC patients. Moreover, SERPINB5 could induce EMT and angiogenesis by activating the TNF-α/NF-κB pathway, thereby promoting the invasion and migration of CRC cells.

The Role of Galectin3, Tubulinβ, and Maspin in Promoting Tumor Budding in Colorectal Carcinoma and Their Clinical Implications

Colorectal cancer (CRC) is a leading cause of death worldwide. Despite the advances in surgical and therapeutic management, tumor metastases and poor prognosis are still major problems. Tumor budding is a relevant prognostic factor in CRC, and it can predict tumor metastasis. Galectin3 is responsible for the development and progression of many cancers through the regulation of cell-cell/cell-matrix interactions and tumor cell invasion. Tubulin is a microtubule protein, and maspin is a serine protease inhibitor; both induce tumor cell invasion through the stimulation of epithelial-mesenchymal transition. This study aims to evaluate the relationship between the expression of galecin3, tubulinβ, and maspin in CRC and clinicopathological features, including tumor budding, their prognostic roles, and clinical implications using immunohistochemistry. Galectin3, tubulinβ, and maspin were detected in tumor cells in 95%, 65%, and 87.5% of cases and in stromal cells in 28.8%, 40%, and 0% of cases. High expression of galectin3 and tubulinβ expression either in tumor cells or stroma was significantly associated with aggressive tumor features such as lymph node metastasis, lymphovascular invasion, tumor budding, and advanced tumor stage. The nucleocytoplasmic expression of maspin in tumor cells showed a significant association with deeper tumor invasion, lymph node metastasis, tumor budding, and advanced tumor stage. Significant associations were found between high galectin3 tumor cell expression and nucleocytoplasmic maspin and shorter survival. High expression of galectin3, tubulinβ, and nucleocytoplasmic maspin were significantly associated with aggressive tumor features such as tumor invasion, metastasis, high tumor budding, and short survival in CRC. They could be used as biomarkers for tumor budding and tumor aggressiveness in CRC and may be considered for future target therapy.

Clinical Significance of Subcellular Localization of Maspin in Breast Carcinoma: An Immunohistochemical Study Using Two Different Antibodies

Background

Maspin is known to be a tumor suppressor protein: however, its prognostic value in patients with breast cancer remains controversial. The key influential factors contributing to this complexity may be the differences in antibodies used, as well as the positive criteria and sample size. To date, no study has investigated the prognostic significance of maspin expression by using two different antibodies in the same cohort. We aimed to clarify whether differences in antibodies could influence on the prognostic value of maspin in breast cancer patients.

Methods

Immunohistochemical analyses using an anti-maspin antibody (clone G167-70) were performed on 164 resected specimens of invasive carcinoma of no special type (NOS). The correlation with clinicopathological factors was compared to previous results using clone EAW24, with longer follow-up duration.

Results

The subcellular localization of maspin expression was as follows: cytoplasmic-only staining, 3 cases (1.8%), pancellular staining, 43 cases (26.2%); and no staining, 118 cases (72.0%). No nuclear-only staining was observed. There was no significant correlation between clinicopathological characteristics and the pancellualr expression of maspin. The pancellular expression group showed a significantly longer disease-free survival (DFS) than the other groups (P = 0.046). When clone EAW24 was used, the cytoplasmic-only staining group showed significantly shorter DFS than the pancellular staining group (P = 0.003).

Conclusion

Clone EAW24 may be superior to clone G167-70 in selecting breast carcinoma with an aggressive phenotype, while clone G167-70 may be superior to clone EAW24 in selecting non-aggressive breast carcinoma.

Transcriptome Profiling of A549 Xenografts of Nonsmall-cell Lung Cancer Treated with Qing-Re-Huo-Xue Formula

Lung cancer is one of the most common malignant tumors, and non-small cell lung cancer (NSCLC) accounts for 85% of all lung cancer cases. Chinese herbal formula Qing-Re-Huo-Xue (QRHXF) has shown antitumor effects in the NSCLC xenograft mouse model of Lewis cells. However, the molecular mechanisms underlying the antitumor effects of QRHXF remain unknown. In this study, an A549 xenograft mouse model was established, and the mice were then treated with QRHXF or vehicle through oral gavage. Tumor growth was monitored. Tumors were subsequently harvested, and RNA sequencing was performed. Compared with the control group, mice treated with QRHXF showed smaller tumor size and slower tumor growth. RNA sequencing results indicated 36 differentially expressed genes between QRHXF treated and control groups. 16 upregulated and 20 downregulated genes were identified. Enrichment analysis showed four differential expression genes (DEGs) related to tumor growth pathways RASAL2, SerpinB5, UTG1A4, and PDE3A. In conclusion, this study revealed that QRHXF could inhibit tumor growth in an A549 xenograft mouse model, and the target genes of QRHXF may include PDE3A, RASAL2, SERPIB5, and UTG1A4.

Insights into the Role of Tick Salivary Protease Inhibitors during Ectoparasite-Host Crosstalk

Protease inhibitors (PIs) are ubiquitous regulatory proteins present in all kingdoms. They play crucial tasks in controlling biological processes directed by proteases which, if not tightly regulated, can damage the host organism. PIs can be classified according to their targeted proteases or their mechanism of action. The functions of many PIs have now been characterized and are showing clinical relevance for the treatment of human diseases such as arthritis, hepatitis, cancer, AIDS, and cardiovascular diseases, amongst others. Other PIs have potential use in agriculture as insecticides, anti-fungal, and antibacterial agents. PIs from tick salivary glands are special due to their pharmacological properties and their high specificity, selectivity, and affinity to their target proteases at the tick-host interface. In this review, we discuss the structure and function of PIs in general and those PI superfamilies abundant in tick salivary glands to illustrate their possible practical applications. In doing so, we describe tick salivary PIs that are showing promise as drug candidates, highlighting the most promising ones tested in vivo and which are now progressing to preclinical and clinical trials.

Tumour suppression by targeted intravenous non-viral CRISPRa using dendritic polymers

This article demonstrates a fully synthetic strategy enabling CRISPR-mediated activation of tumour suppressor genes in vivo to reduce tumour burden.

Aberrant gene expression is a hallmark of cancer. Although transcription is traditionally considered ‘undruggable’, the development of CRISPR-associated protein 9 (Cas9) systems offers enormous potential to rectify cancer-associated transcriptional abnormalities in malignant cells. However delivery of this technology presents a critical challenge to overcome in order to realize clinical translation for cancer therapy. In this article we demonstrate for the first time, a fully synthetic strategy to enable CRISPR-mediated activation (CRISPRa) of tumour suppressor genes in vivo using a targeted intravenous approach. We show this via highly efficient transcriptional activation of two model tumour suppressor genes, Mammary Serine Protease Inhibitor (MASPIN, SERPINB5) and cysteine-rich 61/connective tissue growth factor/nephroblastoma-overexpressed 6 (CCN6, WISP3), in a mouse model of breast cancer. In particular, we demonstrate that targeted intravenous delivery of can be achieved using a novel nanoscale dendritic macromolecular delivery agent, with negligible toxicity and long lasting therapeutic effects, outlining a targeted effective formulation with potential to treat aggressive malignancies.

Maspin mRNA expression in sentinel lymph nodes predicts non-SLN metastasis in breast cancer patients with SLN metastasis

AIMS

Maspin is known to be a tumour suppressor protein, but its prognostic significance in breast cancer patients is controversial. There is no report focusing on maspin expression in metastatic carcinoma of sentinel lymph nodes (SLNs); we thus investigated maspin mRNA expression in SLNs using the remaining specimens after the one-step nucleic acid amplification (OSNA) assay.

METHODS AND RESULTS

Ninety-three breast cancer patients with SLNs metastasis detected by the OSNA assay were enrolled. All patients experienced additional axillary lymph nodes (LNs) dissection and all dissected LNs were examined histopathologically. Maspin mRNA expression in SLNs was detected in 49.5% (46 of 93) and was correlated significantly with the presence of non-SLN metastasis (P < 0.0001) and ≥4 LN metastases (P = 0.029). In a multivariate logistic analysis, maspin mRNA expression in SLNs (P = 0.0015) had the most significant effect on predicting non-SLN metastasis, followed by pathological tumour size (P = 0.0039) and lymphovascular invasion (P = 0.009). The status of maspin mRNA expression in SLNs was correlated significantly with that of maspin protein expression in the primary carcinoma (P < 0.0001).

CONCLUSIONS

This is the first study, to our knowledge, demonstrating that maspin mRNA expression in SLNs is an independent predictor of non-SLN metastasis and the presence of ≥4 LN metastases in breast cancer patients with SLN metastasis. The investigation of maspin mRNA expression in SLNs using the remaining specimens after the OSNA assay may be useful for predicting the further progression of metastatic carcinoma in breast cancer patients with SLNs metastasis.

Analysis of Maspin Expression in Invasive Ductal Carcinoma of the Breast on Stages IIA and IIIB

Mammary Serine Protease Inhibitor (maspin) is a tumor suppressor gene, a member of the serine protease inhibitor (serpin) family that works by inhibiting motility of cell movement, invasion and metastasis. Maspin expression is expected to be a prognostic factor as well as a predictive factor in mammary tumors. However, in some recent studies, maspin has a variety of expressions. Although it is known that no maspine appears as an indicator of tumor progression and metastasis, recent study has shown that maspine expression is associated with an aggressive phenotype of breast cancer and with a poor prognosis. Correlations between maspine expression and poor prognosis have also been reported in pancreatic, ovarian, thyroid, bladder and lung cancers. Knowledge of the expression and role of this maspin as well as its relationship with the pathogenesis of breast invasive ductal carcinoma is still small. The aim of this study was to look at differences in maspin expression in breast-invasive ductal carcinoma of stage IIA and stage IIIB groups. This research method used analytic observational research with cross sectional approach. The samples were invasive carcinoma of NST paraffin at the Department of Anatomic Pathology of Dr Soetomo Hospital, Surabaya, from January to December 2015. Thirty samples were divided into two groups, namely stage IIA and stage IIIB groups and immunohistochemical examination with maspin antibody was carried out. The difference of maspin expression in stage IIA and stage IIIB was analyzed using Mann-Whitney statistic test. There were significant differences in maspin expression between stage IIA and stage IIIB groups, where stage IIA has a high maspin expression rather than stage IIIB.

Predictive Value of Maspin and Ki-67 Expression in Transurethral Resection Specimens in Patients with T1 Bladder Cancer

Aims and background

To evaluate the clinical significance of maspin and Ki-67 expression in patients with newly diagnosed T1 bladder cancer.

Methods and study design

Maspin and Ki-67 expression was investigated by immunohistochemistry from paraffin-embedded tissues of 68 patients undergoing transurethral resection for bladder cancer. Clinicopathological data were retrospectively reviewed from available charts and pathological reports. Maspin and Ki-67 expression levels were classified according to the staining percentage. Cases in which at least 5% of the tumor cells stained for maspin were scored as positive. Ki-67 labeling index was considered to be positive when samples demonstrated >10% reactivity.

Results

Maspin expression was found as an independent predictor of recurrence and progression (P <0.05). Patients with negative maspin expression were 2.191 times more likely to relapse than patients with positive maspin expression. Patients with negative maspin expression were 4.345 times more likely to progress than patients with positive maspin expression. Furthermore, the maspin-negative group was found to have shorter recurrence and progression-free survival (P <0.05). No significant association was found between maspin subcellular localization pattern and recurrence-free, progression-free or overall survival (P >0.05). There was no correlation between Ki-67 expression and tumor recurrence, progression or tumor-related death (P >0.05). Chi-square tests showed a significant relationship between Ki-67 expression and tumor size and tumor grade (P <0.05).

Conclusions

Our findings suggested that the evaluation of maspin expression in stage T1 bladder tumors is a useful prognostic marker for predicting the tumor behavior.

Maspin expression and subcellular localization in invasive ductal carcinoma of the breast: Prognostic significance and relation to microvessel density

Maspin (Mammary serine protease inhibitor) is a tumor suppressor serine. Its clinical significance and role in breast carcinoma are contradictory and inconclusive. Researches demonstrated that the function of maspin differs according to its subcellular localization. This study was conducted to investigate the expression of maspin in invasive ductal carcinoma (IDC) of the breast with special emphasis on its subcellular localization and to evaluate its prognostic role in relation to clinicopathological parameters and microvessel density (MVD) of the tumor. The expression of maspin was evaluated immunohistochemically in 45 IDC cases. The positive rate of maspin expression was 73.3%. Maspin positivity was significantly related to higher tumor grade (p value = 0.041), nodal metastasis (p value = 0.044), perineural invasion (p value = 0.047), and high CD34+MVD (p value = 0.002). Nuclear maspin was detected in 36.6% whereas cytoplasmic maspin was detected in 63.4% of maspin positive cases. A significant inverse relationship was observed between nuclear maspin and high tumor grade (p value = 0.016), and nodal metastasis (p value = 0.047). These results suggest that maspin expression has a prognostic role in breast cancer. Maspin expression is related to increased angiogenesis. Subcellular localization of maspin can strongly affect cancer prognosis. Cytoplasmic maspin relates to poor prognostic parameters whereas nuclear maspin relates to good prognostic ones.

The Opportunity of Precision Medicine for Breast Cancer With Context-Sensitive Tumor Suppressor Maspin

To improve the precision of molecular diagnosis and to develop and guide targeted therapies of breast cancer, it is essential to determine the mechanisms that underlie the specific tumor phenotypes. To this end, the application of a snapshot of gene expression profile for breast cancer diagnosis and prognosis is fundamentally challenged since the tissue-based data are derived from heterogonous cell types and are not likely to reflect the dynamics of context-dependent tumor progression and drug sensitivity. The intricate network of epithelial differentiation program can be concertedly controlled by tumor suppressor maspin, a homologue of clade B serine protease inhibitors (serpin), through its multifaceted molecular interactions in multiple subcellular localizations. Unlike most other serpins that are expressed in multiple cell types, maspin is epithelial specific and has distinct roles in luminal and myoepithelial cells. Endogenously expressed maspin has been found in the nucleus and cytoplasm, and detected on the surface of cell membrane. It is also secreted free and as an exosomal cargo protein. Research in the field has led to the identification of the maspin targets and maspin-associated molecules, as well as the structural determinants of its suppressive functions. The current review discusses the possibility for maspin to serve as a cell type-specific and context-sensitive marker to improve the precision of breast cancer diagnosis and prognosis. These advancements further suggest a new window of opportunity for designing novel maspin-based chemotherapeutic agents with improved anti-cancer potency. J. Cell. Biochem. 118: 1639-1647, 2017. © 2017 Wiley Periodicals, Inc.

Expression of maspin in invasive fungal rhinosinusitis

OBJECTIVE

This study aimed to test the expression of maspin in invasive fungal rhinosinusitis and explore its value in diagnosing invasive fungal rhinosinusitis.

METHODS

Forty-two fungal rhinosinusitis cases (12 invasive and 30 non-invasive) were selected as the experimental group, and 30 chronic rhinosinusitis cases comprised the control group. Maspin expression was assessed in nasal mucous membrane specimens by immunohistochemical staining.

RESULTS

Compared with the control group, maspin expression was down-regulated in the fungal rhinosinusitis group (p < 0.05). Furthermore, the staining score for maspin was lowest in the invasive fungal rhinosinusitis group, as compared with both the non-invasive fungal rhinosinusitis group and the control group (p < 0.05). A maspin staining score of 5.70 was the critical value for diagnosis of invasive fungal rhinosinusitis, with sensitivity and specificity of 91.7 per cent and 88.3 per cent, respectively.

CONCLUSION

The results of this study suggest that the maspin staining score may be a biomarker for effective and rapid diagnosis of invasive fungal rhinosinusitis.

IKKα inibition by a glucosamine derivative enhances Maspin expression in osteosarcoma cell line

Chronic inflammation has been associated to cancer development by the alteration of several inflammatory pathways, such as Nuclear Factor-κB pathway. In particular, IκB kinase α (IKKα), one of two catalytic subunit of IKK complex, has been described to be associated to cancer progression and metastasis in a number of cancers. The molecular mechanism by which IKKα affects cancer progression is not yet completely clarified, anyway an association between IKKα and the expression of Maspin (Mammary Serine Protease Inhibitor or SerpinB5), a tumor suppressor protein, has been described. IKKα shuttles between cytoplasm and nucleus, and when is localized into the nuclei, IKKα regulates the expression of several genes, among them Maspin gene, whose expression is repressed by high amount of nuclear IKKα. Considering that high levels of Maspin have been associated with reduced metastatic progression, it could be hypothesized that the repression of IKKα nuclear translocation could be associated with the repression of metastatic phenotype. The present study is aimed to explore the ability of a glucosamine derivative, 2-(N-Carbobenzyloxy)l-phenylalanylamido-2-deoxy-β-d-glucose (NCPA), synthesized in our laboratory, to stimulate the production of Maspin in an osteosarcoma cell line, 143B. Immunofluorescence and Western blotting experiments showed that NCPA is able to inhibit IKKα nuclear translocation, and to stimulate Maspin production. Moreover, in association with stimulation of Maspin production we found the decrease of β1 Integrin expression, the down-regulation of metalloproteases MMP-9 and MMP-13 production and cell migration inhibition. Taking in account that β1 Integrin and MMP-9 and -13 have been correlated with the invasiveness of osteosarcoma, considering that NCPA affects the invasiveness of 143B cell line, we suggest that this molecule could affect the osteosarcoma metastatic ability.

EGFR Signaling Regulates Maspin/SerpinB5 Phosphorylation and Nuclear Localization in Mammary Epithelial Cells

Maspin (SerpinB5) is a non-inhibitory serpin (serine protease inhibitor) with very diverse biological activities including regulation of cell adhesion, migration, death, control of gene expression and oxidative stress response. Initially described as a tumor and metastasis suppressor, clinical data brought controversies to the field, as some studies reported no correlation between SerpinB5 expression and prognosis value. These data underscore the importance of understanding SerpinB5 function in a normal physiological context and the molecular mechanism involved. Several SerpinB5 phosphoforms have been detected in different cell lines, but the signaling pathways involved and the biological significance of this post-translational modification in vivo remains to be explored. In this study we investigated SerpinB5 expression, subcellular localization and phosphorylation in different stages of the mouse mammary gland development and the signaling pathway involved. Here we show that SerpinB5 is first detected in late pregnancy, reaches its highest levels in lactation and remains at constant levels during post-lactational regression (involution). Using high resolution isoelectric focusing followed but immunoblot, we found at least 8 different phosphoforms of SerpinB5 during lactation, which decreases steadily at the onset of involution. In order to investigate the signaling pathway involved in SerpinB5 phosphorylation, we took advantage of the non-transformed MCF-10A model system, as we have previously observed SerpinB5 phosphorylation in these cells. We detected basal levels of SerpinB5 phosphorylation in serum- and growth factor-starved cells, which is due to amphiregulin autocrine activity on MCF-10A cells. EGF and TGF alpha, two other EGFR ligands, promote important SerpinB5 phosphorylation. Interestingly, EGF treatment is followed by SerpinB5 nuclear accumulation. Altogether, these data indicate that SerpinB5 expression and phosphorylation are developmentally regulated. In vitro analyses indicate that SerpinB5 phosphorylation is regulated by EGFR ligands, but EGF appears to be the only able to induce SerpinB5 nuclear localization.

Decreased Immunoreactive Maspin Expression in Intermediate Thickness and Thick Primary Melanoma Lesions

Maspin is a member of the serpin family of protease inhibitors. It is a 42 kDa cytoplasmic protein that is reported to have tumour suppressor activity. The loss of maspin gene expression is correlated with increased invasiveness and the risk of metastases in breast cancer. We studied maspin expression in primary melanoma lesions obtained from 76 patients. Immunostaining of 5 μm sections for maspin expression was obtained using the citrate antigen retrieval method. The extent of immunostaining was scored by recording the proportion of immunoreactive cells and the intensity of immunostaining. Our results demonstrated that maspin expression was down-regulated in intermediate thickness and thick melanoma lesions compared with thin lesions. These results suggest that loss of maspin expression might play a role in melanoma progression, invasion and metastatic dissemination. Further studies are needed to clarify the clinicopathological significance of maspin expression in melanoma.

Characterization, biomedical and agricultural applications of protease inhibitors: A review

This review describes Protease Inhibitors (PIs) which target or inhibit proteases, protein digesting enzymes. These proteases play a crucial task in many biological events including digestion, blood coagulation, apoptosis etc. Regardless of their crucial roles, they need to be checked regularly by PIs as their excess may possibly damage host organism. On basis of amino acid composition of PIs where Protease-PI enzymatic reactions occur i.e. serine, cysteine, and aspartic acid, they are classified. Nowadays, various PIs are being worked upon to fight various parasitic or viral diseases including malaria, schistosomiasis, colds, flu', dengue etc. They prevent an ongoing process begun by carcinogen exposure by keeping a check on metastasis. They also possess potential to reduce carcinogen-induced, increased levels of gene amplification to almost normal levels. Some PIs can principally be used for treatment of hypertension and congestive heart failure by blocking conversion of angiotensin I to angiotensin II for example Angiotensin-converting enzyme inhibitors (ACEIs). Also PIs target amyloid β-peptide (Aβ) level in brain which is prime responsible for development of Alzheimer's Disease (AD). Also, PIs inhibit enzymatic activity of HIV-1 Protease Receptor (PR) by preventing cleavage events in Gag and Gag-Pol that result in production of non-virulent virus particles.

Promoter Hypomethylation of Maspin Inhibits Migration and Invasion of Extravillous Trophoblast Cells during Placentation

Objective

Extravillous trophoblast (EVT) cells invade the endometrium and the maternal spiral arterioles during the first trimester. Mammary Serine Protease Inhibitor (Maspin, SERPINB5) plays a putative role in regulating the invasive activity of cytotrophoblasts. The maspin gene is silenced in various cancers by an epigenetic mechanism that involves aberrant cytosine methylation. We investigated the effect of the methylation status of the maspin promoter on the maspin expression and the aggressiveness of EVT cells.

Methods

Western blotting was used to detect the maspin protein expression in EVT cells upon hypoxia. The proliferative ability, the apoptosis rate and the migration and invasiveness were measured with Cell Counting Kit-8 assay, Flow Cytometry technology and Transwell methods. Subsequently, we treated cells with recombinant maspin protein. The methylation degree of maspin promoter region upon hypoxia/ decitabine was detected by bisulfite sequencing PCR and methylation-specific PCR. Finally, we explored the effects of decitabine on maspin protein expression and the aggressiveness of EVT cells.

Results

Hypoxia effectively increased maspin protein expression in EVT cells and significantly inhibited their aggressiveness. The addition of recombinant maspin protein inhibited this aggressiveness. Decitabine reduced the methylation in the maspin promoter region and effectively increased the maspin protein expression, which significantly weakened the migration and invasiveness of EVT cells.

Discussion

The methylation status of the maspin promoter is an important factor that affects the migration and invasion of EVT cells during early pregnancy. A decrease in the methylation status can inhibit the migration and invasion of EVT cells to affect placentation and can result in the ischemia and hypoxia of placenta.

Promoter hypomethylation and increased maspin expression in preeclamptic placentas in a Chinese population

OBJECTIVE

Preeclampsia is thought to begin with shallow trophoblast invasion and inadequate spiral artery remodeling. Maspin, a tumor-suppressor gene, plays a regulatory role in trophoblast invasion and motility. The tissue-specific methylation of the maspin promoter can regulate maspin gene expression in various cancers. We sought to detect maspin gene expression and assess the degrees of methylation of maspin promoter regions in preeclamptic placentas in the Han Chinese population and to investigate the potential role of maspin in the pathophysiology of preeclampsia.

METHODS

We conducted RT-PCR, immunohistochemistry and western blotting to characterize maspin gene expression and protein levels in the placentas from normal and preeclamptic pregnancies. Finally, using methylation-specific PCR and bisulfite sequencing PCR, we detected the degrees of methylation of the promoter regions of maspin in each of the two studied groups.

RESULTS

Maspin expression was increased at the mRNA and protein levels in the preeclamptic placentas compared to the control group. Maspin immunohistochemical staining revealed positive staining in the syncytio-cytotrophoblast layers and more diffuse staining in the preeclamptic group. The mean methylation level of the analyzed promoter region was significantly hypomethylated in the preeclamptic placentas compared to the control placentas, pointing to a negative relationship between maspin promoter methylation and gene expression.

DISCUSSION

Hypomethylation of the maspin promoter results in increased expression of maspin in preeclamptic placentas, which suggests a negative relationship between maspin methylation and maspin expression in this Han Chinese population. Thus, maspin is likely involved in the etiology of preeclampsia.

Nuclear location of tumor suppressor protein maspin inhibits proliferation of breast cancer cells without affecting proliferation of normal epithelial cells

Background

Maspin, which is classified as a tumor suppressor protein, is downregulated in many types of cancer. Several studies have suggested potential anti-proliferative activity of maspin as well as sensitizing activity of maspin for therapeutic cytotoxic agents in breast cancer tissue culture and animal models. All of the experimental data gathered so far have been based on studies with maspin localized cytoplasmically, while maspin in breast cancer tumor cells may be located in the cytoplasm, nucleus or both. In this study, the effect of maspin cytoplasmic and nuclear location and expression level on breast cancer proliferation and patient survival was studied.

Methods

Tissue sections from 166 patients with invasive ductal breast cancer were stained by immunohistochemistry for maspin and Ki-67 protein. The localization and expression level of maspin were correlated with estimated patient overall survival and percent of Ki-67-positive cells. In further studies, we created constructs for transient transfection of maspin into breast cancer cells with targeted cytoplasmic and nuclear location. We analyzed the effect of maspin location in normal epithelial cell line MCF10A and three breast cancer cell lines - MCF-7, MDA-MB-231 and SKBR-3 - by immunofluorescence and proliferation assay.

Results

We observed a strong positive correlation between moderate and high nuclear maspin level and survival of patients. Moreover, a statistically significant negative relationship was observed between nuclear maspin and Ki-67 expression in patients with invasive ductal breast cancer. Spearman’s correlation analysis showed a negative correlation between level of maspin localized in nucleus and percentage of Ki-67 positive cells. No such differences were observed in cells with cytoplasmic maspin. We found a strong correlation between nuclear maspin and loss of Ki-67 protein in breast cancer cell lines, while there was no effect in normal epithelial cells from breast. The anti-proliferative effect of nuclear maspin on breast cancer cells was statistically significant in comparison to cytoplasmic maspin.

Conclusions

Our results suggest that nuclear maspin localization may be a prognostic factor in breast cancer and may have a strong therapeutic potential in gene therapy. Moreover, these data provide a new insight into the role of cytoplasmic and nuclear fractions of maspin in breast cancer.

Maspin: molecular mechanisms and therapeutic implications

Maspin, a non-inhibitory member of the serine protease inhibitor superfamily, has been characterized as a tumor suppressor gene in multiple cancer types. Among the established anti-tumor effects of Maspin are the inhibition of cancer cell invasion, attachment to extracellular matrices, increased sensitivity to apoptosis, and inhibition of angiogenesis. However, while significant experimental data support the role of Maspin as a tumor suppressor, clinical data regarding the prognostic implications of Maspin expression have led to conflicting results. This highlights the need for a better understanding of the context dependencies of Maspin in normal biology and how these are perturbed in the context of cancer. In this review, we outline the regulation and roles of Maspin in normal and developmental biology while discussing novel evidence and emerging theories related to its functions in cancer. We provide insight into the immense therapeutic potential of Maspin and the challenges related to its successful clinical translation.

A versatile monoclonal antibody specific to human SERPINB5

Maspin (SERPINB5) is a member of the Clade B subgroup of the large superfamily of serine protease inhibitors. It is proposed that maspin is a tumor suppressor; however, its molecular role remains to be elucidated. Here we report the characterization of a mouse monoclonal antibody directed against human maspin. This antibody, 16F7, recognizes maspin in both its native and denatured form, unlike several other commercial antibodies tested in this study. It will be a useful and versatile tool for future analyses of the biological function of maspin.

Role of maspin in cancer

Maspin (mammary serine protease inhibitor), is a member of the serine protease inhibitor/non-inhibitor superfamily. Its expression is down-regulated in breast, prostate, gastric and melanoma cancers but over-expressed in pancreatic, gallbladder, colorectal, and thyroid cancers suggesting that maspin may play different activities in different cell types. However, maspin expression seems to be correlated with better prognosis in prostate, bladder, lung, gastric, colorectal, head and neck, thyroid and melanoma cancer. In breast and ovarian cancer maspin significance is associated with its subcellular localization: nucleus maspin expression correlates with a good prognosis, whilst in pancreatic cancer it predicts a poor prognosis. Since tumor metastasis requires the detachment and invasion of tumor cells through the basement membrane and stroma, a selectively increased adhesion by the presence of maspin may contribute to the inhibition of tumor metastasis. Furthermore the different position of maspin inside the cell or its epigenetic modifications may explain the different behavior of the expression of maspin between tumors. The expression of maspin might be useful as a prognostic and possibly predictive factor for patients with particular types of cancer and data can guide physicians in selecting therapy. Its expression in circulating tumor cells especially in breast cancer, could be also useful in clinical practice along with other factors, such as age, comorbidities, blood examinations in order to select the best therapy to be carried out. Focusing on the malignancies in which maspin showed a positive prognostic value, therapeutic approaches studied so far aimed to re-activate a dormant tumor suppressor gene by designed transcription factors, to hit the system that inhibits the expression of maspin, to identify natural substances that can determine the activation and the expression of maspin or possible “molecules binds” to introduce maspin in cancer cell and gene therapy capable of up-regulating the maspin in an attempt to reduce primarily the risk of metastasis.

Further studies in these directions are necessary to better define the therapeutic implication of maspin.

Effect of progesterone receptor status on maspin synthesis via nitric oxide production in neutrophils in human breast cancer

BACKGROUND

Although progesterone receptor (PR) status, similarly to estrogen receptor status, is of prognostic importance in breast cancer, the involvement of the PR in breast cancer remains obscure. Studies were conducted to determine the function of the PR in neutrophils in the nitric oxide-induced synthesis of maspin, an anti-breast-cancer protein produced in nonmalignant mammary cells and in neutrophils in the circulation.

METHODS

PR status was determined by immunohistochemistry. Maspin synthesis was determined by in-vitro translation of messenger RNA and quantified by enzyme-linked immunosorbent assay. Nitric oxide was determined by the methemoglobin method.

RESULTS

It was found that PR status in neutrophils was identical with that in malignant breast tissues. A Scatchard plot for progesterone binding to normal and PR-positive (PR+) neutrophils revealed that whereas normal neutrophils had 11.5 × 10(10) PR sites/cell with K d = 47.619 nM, PR+ neutrophils had 6.6 × 10(10) PR sites/cell with K d = 47.619 nM. The progesterone negative (PR-) neutrophils failed to bind to progesterone. Incubation of normal and PR+ neutrophils with 25 nM progesterone produced 1.317 μM NO and 2.329 nM maspin; the PR+ neutrophils produced 0.72 μM NO and 1.138 nM maspin. The PR- neutrophils failed to produce any NO or maspin in the presence of progesterone. Inhibition of progesterone-induced NO synthesis led to complete inhibition of maspin synthesis in all neutrophils.

CONCLUSION

These results suggest that estrogen and progesterone complement each other in NO-induced maspin synthesis, and do not necessarily antagonize in the synthesis of the anti-breast-cancer protein.

Cathepsin E, maspin, Plk1, and survivin are promising prognostic protein markers for progression in non-muscle invasive bladder cancer

Bladder cancer is a common cancer with particularly high recurrence after transurethral resection. In this study, we investigated the prognostic value of the protein expression of cathepsin E, maspin, polo-like kinase 1 (Plk1), and survivin in patients with stage Ta and T1 urothelial carcinomas. Transcripts from the four genes encoding these proteins were previously included in gene expression signatures for outcome prediction for Ta/T1 bladder cancer. We used three different tissue microarrays with 693 non-muscle invasive urothelial carcinomas from Danish, Swedish, and Spanish patient cohorts with long-term follow-up. Protein expression was measured by immunohistochemistry, and antibody specificity was validated by Western blotting. In the Danish patient cohort, we found the expression of cathepsin E, maspin, Plk1, and survivin to be significantly associated with progression to stage T2 to T4 bladder cancer (for each marker: log-rank test; P < 0.001). Multivariate Cox regression analysis identified cathepsin E (P < 0.001), Plk1 (P = 0.021), maspin (P = 0.001), and survivin (P = 0.001) as independent prognostic markers. Furthermore, maspin, survivin, and cathepsin E expression significantly subgrouped patients already stratified by European Organization for Research and Treatment of Cancer risk scores. Finally, we successfully validated the results in tumors from 410 patients from both Sweden and Spain. We conclude that all four protein markers may have prognostic value in non-muscle invasive bladder cancer for guiding optimal treatment of patients. Additional prospective studies are needed for further validation of the clinical relevance of this marker panel.

Comparative proteomic analysis of the function and network mechanisms of MASPIN in human lung cells

MASPIN, which is also known as Serpin B5, is a novel tumor suppressor. Emerging evidence suggests that MASPIN acts as a multifaceted protein in various types of cancer, including prostate, breast and pancreatic cancer. It interacts with diverse groups of intercellular and extracellular proteins, regulating cell adhesion, motility, apoptosis and angiogenesis, and is involved in mammary gland development. As MASPIN is a multifunctional factor in cancer pathways, its function remains poorly illuminated. In this study, we compared the protein profiles of LC5 cell lines with MASPIN overexpression and knockdown using comparative two-dimensional gel electrophoresis. The differences in protein expression, visualized as differences in spots, were identified by time-of-flight (TOF)/TOF mass spectometry. Significant differences were observed between overexpressing and knocked down cells, including eight spots that were unique and sixteen spots that were up- or down-regulated by more than 4-fold. Six genes, including Sdccag8, Ldoc1, SCAI, SDCCAG3, CT62 and NEDD9 were unique in MASPIN-expressing cell lines, but absent in knock-out cell lines, in which most of them play a significant role in the invasion of cancer cells. Moreover, the Brms1 and CAGE1 genes were identified as being uniquely expressed in knocked down cell lines, which were associated with the development and progression of tumors. The data from this study shed some light on the function, as well as the general network mechanisms of MASPIN in lung cancer.

Maspin and MCM2 immunoprofiling in salivary gland carcinomas

BACKGROUND

The pathogenesis of salivary gland carcinomas is very complex and prognostic markers are difficult to find in these carcinomas of which the different subtypes have varying malignant potential. The study was conducted to examine the cellular distribution of maspin and MCM2 in salivary gland carcinomas and their value to predict lymph node metastasis.

MATERIALS AND METHODS

Fifty three paraffin blocks of different lesions (15 muco-epidermoid carcinoma, 14 adenoid cystic carcinoma, 3 epi-myoepithelial carcinoma, 5 salivary duct carcinoma, 5 malignant pleomorphic adenoma, 6 polymorphous low grade adenocarcinoma and 5 acinic cell carcinoma) were prepared for immunohistochemical staining with maspin and MCM2 antibodies. ANOVA and Pearson correlation tests were used for the statistical analysis of the results.

RESULTS

All salivary gland carcinomas express maspin and MCM2 with variable cellular localization. There was a significant difference in the expression of each antibody between mucoepidermoid carcinoma, adenoid cystic carcinoma and polymorphous low grade adenocarcinoma. No association was found between examined markers and lymph node metastasis.

CONCLUSIONS

Salivary gland carcinomas express maspin and MCM2 with variable levels and cellular localization, consisting important markers of biological behavior in these tumors. The level of MCM2 expression can be used in the differential diagnosis of adenoid cystic carcinoma and polymorphous low grade adenocarcinoma. Further study with large sample size is recommended to assess their value in prediction of lymph node metastasis.

High expression of miR-21 in tumor stroma correlates with increased cancer cell proliferation in human breast cancer

Low-risk and high-risk breast cancer patients are stratified primarily according to their lymph node (LN) status and grading. However, some low-risk patients relapse, and some high-risk patients have a favorable clinical outcome, implying a need for better prognostic and predictive tests. Micro RNAs are often aberrantly expressed in cancer and microRNA-21 is upregulated in a variety of cancers, including breast cancer. High miR-21 levels have been associated with poor prognosis. To determine the cellular localization of miR-21 and to compare its expression levels with histopathological features, we performed in situ hybridization and semi-quantitative assessment of the miR-21 signal on 12 LN negative grade I (assumed low risk), and 12 LN positive grade II (high risk) breast cancers. miR-21 was predominantly seen in cancer associated fibroblast-like cells, with no difference in expression levels between grade I and grade II carcinomas. Immunohistochemical scoring of the prognostic proliferation marker Ki-67 and tumor suppressor p53 showed that the miR-21 expression levels significantly correlated with the Ki-67 score (p = 0.043), whereas no correlation between p53 and miR-21 was found. Our results indicate that miR-21 may contribute to improve clinical stratification according to growth rate and facilitate tailored treatment of breast cancer patients.

DNA methylation or histone modification status in metastasis and angiogenesis-related genes: a new hypothesis on usage of DNMT inhibitors and S-adenosylmethionine for genome stability

Metastasis is a leading cause of mortality and morbidity in cancer. This process needs angiogenesis. The biology underlying cancer, metastasis, and angiogenesis has been investigated so as to determine the therapeutic targets. Invasive and metastatic cancer cells have undergone numerous genetic and epigenetic changes, manifested by cytoskeletal changes, loss of adhesion, and expression of proteolytic enzymes that degrade the basement membrane. Additionally, in endothelial cells, some epigenetic modifications occur during the formation of angiogenesis. Researchers have used some methylation inhibitors, histone deacetylase inhibitors, or methylating agents (such as S-adenosylmethionine, SAM) against cancer and angiogenesis. Although they are effective to beat these diseases, each one results in differentiation or changes in genome structure. We review epigenetically modified genes related with angiogenesis and metastasis in cancer and endothelial cells, and suggest a new proposal. This hypothesis has discussed the importance of the usage of DNA methylation inhibitors together with SAM to prevent tumor progression and genome instability or changes resulting in additional diseases.

Clinical significance of Maspin promoter methylation and loss of its protein expression in invasive ductal breast carcinoma: correlation with VEGF-A and MTA1 expression

Maspin is a serine protease inhibitor with tumor-suppressor activity. Maspin can suppress tumor growth and metastasis in vivo and tumor cell motility and invasion in vitro. Previous studies indicate that the loss of Maspin expression is closely linked to aberrant methylation of the Maspin promoter. We examined the promoter methylation status of Maspin in tumor and corresponding serum of breast cancer patients. In addition, protein expression of this gene was also assessed to determine possible correlation between promoter hypermethylation and gene silencing. Further, we investigated the correlation of Maspin expression with vascular endothelial growth factor (VEGF-A) and MTA1 expression. Maspin methylation was analyzed by methylation-specific PCR in 100 invasive ductal breast carcinoma patients' tumors and circulating DNA in a prospective study. Promoter hypermethylation was correlated with expression of the encoded protein in tumors by immunohistochemistry. Significant correlation was observed between promoter hypermethylation of Maspin (r = +0.88; p ≤ 0.0001) in tumors and paired sera. Significant association was found between Maspin promoter hypermethylation and loss of its protein expression (p = 0.01, OR = 3.1, 95% CI = 1.3-7.4). The expression of VEGF-A and MTA1 was lower in tumors with high Maspin expression compared to tumors with loss of Maspin expression. Our results indicate that aberrant promoter methylation is associated with loss of Maspin immunoreactivity in breast cancer tissues. Further, loss of Maspin expression is significantly correlated with increased expression of VEGF-A and MTA1.

Protease inhibitors: a panacea?

With the increasing evidence of protease involvement in several diseases, novel strategies for drug development involve the use of protease inhibitors (PIs). The local balance between protease inhibitors and proteases is an important determinant of the occurrence and progression of a particular disease. Hence, enzymes and their cognate inhibitors are finding their applications as diagnostic and prognostic markers. PIs are widely implicated for their use in host defense against infection, tissue repair and matrix production, blood coagulation, cancer, and they are, therefore, the current focus as therapeutic alternatives for major diseases such as AIDS and Alzheimer's diseases. This review is a brief summary of the varied role of protein protease inhibitors in controlling the activity of aberrant enzymes in several diseases afflicting mankind today.

Maspin expression in renal cell carcinoma and its correlation with clinicopathologic parameters

OBJECTIVES

To investigate the relationship between maspin expression and prognostic parameters in renal cell carcinoma (RCC) with relevance to vascular endothelial growth factor (VEGF) expression and microvessel density.

METHODS

One-hundred twenty-four patients with RCC of varying histologic types who underwent radical or partial nephrectomy were studied. The mean age of the patients was 59.4 years (range, 28-84). Maspin, VEGF, and microvessel density were studied by the universal avidin-biotin complex peroxidase method. Sections of 5-μm thickness were taken from paraffin blocks for immunohistochemical study. Cytoplasmic and/or nuclear staining were scored for maspin as negative and positive for all tumor cells.

RESULTS

Cytoplasmic maspin expression was positive in 51 (41.1%) patients. Nuclear maspin expression was not seen in any of the materials. Maspin expression decreased as tumor size increased (P = .036) without any specific relation to tumor subtypes (P = .583), and decreased as the pathologic stages increased without reaching statistical significance (P = .053). There were no correlations between maspin positivity and either VEGF expression or microvessel density.

CONCLUSIONS

In RCC, maspin expression is reduced with increased tumor size. Studies with larger series may be contributory in defining the role of maspin expression in RCC. Moreover, regulation of maspin expression genes appears to have the potential to lead to new treatment approaches.

Acetyl salicylic acid (aspirin) improves synthesis of maspin and lowers incidence of metastasis in breast cancer patients [corrected]

Maspin, a 42 kDa protein produced in normal breast cells, has been shown to inhibit the invasion and metastasis of breast cancer in an animal model. Ingestion of acetylsalicylic acid (aspirin) by breast cancer patients has been reported to restore the systemic synthesis of maspin through the stimulation of systemic nitric oxide production. Studies were carried out to determine the effect of aspirin on the incidence of breast cancer metastasis, which is reported to occur in 50% of patients who have previously received chemotherapy, radiation, and/or surgery. Thirty-five female patients (aged 41-65 years) with breast cancer who had previously received these therapies took one 75 mg/70 kg body weight enteric-coated aspirin tablet every 24 h, after an adequate meal, for 3 years. Their plasma nitric oxide and maspin levels were measured. The occurrence of metastasis was ascertained monthly by a qualified oncologist, and confirmed, if necessary, by biopsy. Daily ingestion of aspirin by participants resulted in an increase in maspin levels from 0.95 ± 0.04 to 4.63 ± 0.05 nM after 24 h. These levels were maintained for 3 years. These studies suggest that daily ingestion of aspirin might significantly reduce the incidence of breast cancer metastasis in patients who have previously received anticancer therapies.

Restoration by aspirin of impaired plasma maspin level in human breast cancer

Maspin, an anti breast cancer protein, is produced in the normal mammary cells but not in malignant cells in breast cancer. We investigated the effect of aspirin induced increase of plasma nitric oxide (NO) on plasma maspin production in breast cancer patients. Fifteen breast cancer patients (35-65 years), who had not yet undergone any cancer therapy, and an equal number of age matched normal female volunteers participated in the study. They were asked not to take any medication for two weeks. All participants then ingested 150 mg of aspirin. Plasma NO and maspin levels were determined before and at 60 min after the ingestion of aspirin. It was found that the maspin level in plasma increased to 4.63+/-0.02 nM from the basal 0.95+/-0.012 nM (p<0.001) with increase of plasma NO from 0.60+/-0.03 microM to 2.08+/-0.030 microM (p<0.001) in breast cancer patients. In normal volunteers the basal maspin increased from 4.76+/-0.041 to 9.36+/-0.036 nM (p<0.001) with increase of NO from 2.15+/-0.08 to 3.36+/-0.04 microM (p<0.001) at the same period. These results indicated that the ingestion of aspirin might be beneficial for breast cancer through increased maspin production.

High expression of maspin is associated with early tumor relapse in breast cancer

Maspin is a serine protease inhibitor with tumor suppressor activity. Maspin can suppress tumor growth and metastasis in vivo and tumor cell motility and invasion in vitro. Maspin also modulates apoptosis of tumor cells, possibly by modulating the expression of the B-cell lymphoma-2 family member. p53 regulates the expression of the tumor suppressor gene maspin. Breast cancer is known for its propensity to recur even after decades. The biology behind this phenomenon of tumor dormancy is poorly understood. This study was conducted to clarify the role of maspin and B-cell lymphoma-2 in early and late recurring breast cancer. The expression of maspin, B-cell lymphoma-2, p53, and estrogen receptor was studied by immunohistochemistry in 73 primary breast cancers and in their metastatic relapses detected within 2 years, or 5 or 10 years after primary surgery. The cytoplasmic expression of maspin was significantly higher in the primary tumors of the early metastasizing breast cancers (first tumor relapse within 2 years) and also in their metastases compared to late metastasizing cancers. An opposite activity was observed in the expression of B-cell lymphoma-2. The level of B-cell lymphoma-2 staining was lower in the early relapsing cancers and significantly lower in their metastases, compared to tumors which metastasized 5 or 10 years after primary surgery. High cytoplasmic expression of maspin and low expression of B-cell lymphoma-2 in primary breast cancer predict early tumor relapse.

Nuclear, compared with combined nuclear and cytoplasmic expression of maspin, is linked in lung adenocarcinoma to reduced VEGF-A levels and in Stage I, improved survival

AIMS

To evaluate whether there is a correlation between the subcellular localization of maspin and the histological, molecular and biological features of pulmonary adenocarcinoma, particularly addressing the hypothesis that the tumour inhibitor properties of maspin may be linked to a nuclear, compared with a combined nuclear and cytoplasmic expression pattern.

METHODS AND RESULTS

The subcellular expression of maspin was determined in 80 resected pulmonary adenocarcinomas (Stage I, 46; Stage II, 10; Stage III, 20; Stage IV, 4) and correlated with histological grade, proliferative rate, p53 expression, vascular endothelial growth factor (VEGF)-A levels, and prognosis (mean follow-up of 41.5 months). Cases with nuclear (N) maspin (n = 47), compared with the [N + cytoplasmic (C)] group (n = 28), showed lower (P <or= 0.05): histological grade, proliferative rate, p53 expression and VEGF-A levels. Cox multivariate analysis revealed in stage I adenocarcinomas (N) maspin as the only predictor of improved survival.

CONCLUSIONS

(N) maspin selects lung adenocarcinomas with distinct molecular and clinical features, supporting the hypothesis that its tumour inhibitor properties may be linked to its nuclear localization.

Maspin Expression in Oral Squamous Cell Carcinoma

Maspin (mammary serine protease inhibitor) is a member of the serpin superfamily of protease inhibitors and it has a role as a tumor suppressor. Maspin has been reported to be important in processes relevant to tumor growth and metastasis such as cell invasion, angiogenesis, and apoptosis. A high expression of maspin was correlated with better rates of survival and absence of nodal metastases in head and neck squamous cell carcinoma. In contrast, some studies have shown that maspin overexpression is correlated with a poor prognosis in pancreatic and ovarian cancers and in lung adenocarcinoma. The aim of this study was an immunohistochemical evaluation of the maspin expression in oral squamous cell carcinoma and thus 89 patients were evaluated. Maspin expression in oral squamous cell carcinoma was significantly associated with the tumor differentiation grade (chi test: P = 0.0318) and the lymph node status (chi test: P < 0.005), but not with the tumor stage (chi test: P = 0.666). Metastatic involvement of lymph nodes was observed more frequently in maspin-negative cases than in tumors with more than 5% of positive cells (P = 0.0024). The present results confirm that maspin expression predicts a better prognosis in oral squamous cell carcinoma and that maspin probably plays a role in tumor progression.

Prognostic significance of maspin in pancreatic ductal adenocarcinoma: tissue microarray analysis of 223 surgically resected cases

Maspin (SERPINB5), a serine proteinase inhibitor, was first identified as a potential tumor suppressor on the basis of its differential expression between normal mammary epithelial cells and human breast carcinoma cell lines. Recent studies have shown that maspin might be a prognostic tumor marker. Pancreatic ductal adenocarcinoma acquires maspin expression through hypomethylation of the maspin promoter. However, no study has investigated the prognostic significance of maspin expression in pancreatic ductal adenocarcinomas. In this study, we investigated maspin protein expression in a large series of 223 surgically resected pancreatic ductal adenocarcinomas using immunohistochemical staining and high throughput tissue microarrays. Maspin expression was correlated with postoperative survival and other clinicopathologic factors. Maspin was detected in 209 of these 223 (94% cases) pancreatic ductal adenocarcinomas including 39 (18% cases) focal (5-50% tumor cells) and 170 (76% cases) diffuse (>50% tumor cells). Fourteen (or 6% cases) pancreatic ductal adenocarcinomas did not show maspin expression by immunohistochemical staining (<5% tumor cells). Normal ductal epithelium is not labeled with maspin. Overexpression of maspin in pancreatic ductal adenocarcinoma is associated with worse postoperative survival especially in patients whose tumors exhibit diffuse expression of maspin. After adjusting other clinicopathologic factors, maspin expression remains to be an independent adverse prognosticator for postoperative survival. Maspin expression is not associated with patient age, gender, tumor size, tumor pathologic stage, lymph node status, and vascular invasion or perineural invasion. Nuclear labeling of maspin is associated with better tumor differentiation although this staining pattern is not associated with a better prognosis. In addition, maspin overexpression is also observed in 48% low-grade (grades 1a and 1b) pancreatic intraepithelial neoplasias (PanINs) and 78% high-grade (grades 2 and 3) PanINs, suggesting that maspin upregulation occurs early during the multi-step progression model of pancreatic ductal adenocarcinoma.

Identification of differentially expressed genes in mouse hepatocarcinoma ascites cell line with low potential of lymphogenous metastasis

AIM: To identify genes differentially expressed in mouse hepatocarcinoma ascites cell line with low potential of lymphogenous metastasis.

METHODS: A subtracted cDNA library of mouse hepatocarcinoma cell line with low potential of lympho-genous metastasis Hca-P and its synogenetic cell line Hca-F with high metastatic potential was constructed by suppression subtracted hybridization (SSH) method. The screened clones of the subtracted library were sequenced and GenBank homology search was performed.

RESULTS: Fifteen differentially expressed cDNA fragments of Hca-P were obtained which revealed 8 known genes, 4 expressed sequence tags (ESTs) and 3 cDNAs showed no homology.

CONCLUSION: Tumor metastasis is an incident involving multiple genes. SSH is a useful technique to detect differentially expressed genes and an effective method to clone novel genes.

The associated expression of Maspin and Bax proteins as a potential prognostic factor in intrahepatic cholangiocarcinoma

Background

Maspin, a member of the serpin family, is a suppressor of tumor growth, an inhibitor of angiogenesis and an inducer of apoptosis. Maspin induces apoptosis by increasing Bax, a member of the Bcl-2 family of apoptosis-regulating proteins. In this exploratory study, we investigated the associated expression of Maspin and Bax proteins as a potential prognostic factor in intrahepatic cholangiocarcinoma (IHCCA).

Methods

Twenty-two paraffin-embedded samples were analyzed by immunohistochemical methods using Maspin, Bax and CD34 antibodies. Maspin was scored semiquantitatively (HSCORE). Apoptosis was assessed using an antibody against cleaved caspase-3.

Results

The strong relationship observed between the expression of Maspin and Bax, indicates that Bax is likely to be the key effector of Maspin-mediated induction of apoptosis as indicated by the activation of cleaved caspase-3. We categorized Maspin HSCORE by calculating the optimal cutpoint. A Maspin HSCORE above the cutpoint was inversely related with tumor dimension, depth of tumor and vascular invasion. Uni/multivariate analysis suggests that a Maspin HSCORE below the cutpoint significantly worsens the patients' prognosis. Tumors with Maspin HSCORE below the cutpoint had a shorter survival (11+/-5 months) than did patients with Maspin HSCORE above the cutpoint (27+/-4 months), whereas Kaplan-Meier analysis and logrank test showed no significant difference in overall survival between the patients.

Conclusion

The associated expression of Maspin and Bax might delay tumor progression in IHCCA. Maspin above the cutpoint might counteract tumor development by increasing cell apoptosis, and by decreasing tumor mass and cell invasion. The combined expression of Maspin and Bax appears to influence the susceptibility of tumor cholangiocytes to apoptosis and thus may be involved in delaying IHCCA progression.

Maspin Expression and Its Clinical Significance in Non-Small Cell Lung Cancer

BACKGROUND

Maspin is a member of the serpin (serine protease inhibitor) superfamily, and its exact function in the development and progression of malignant tumors remains controversial, though some experimental studies have revealed potential tumor-suppressor activities. In addition, there have been only a few clinical studies on maspin expression in malignant tumors including non-small cell lung cancer (NSCLC). The purpose of this study was to assess maspin expression and its clinical significance in NSCLC.

METHODS

A total of 210 consecutive patients with completely resected pathological (p-) stage I-IIIA NSCLC were retrospectively reviewed. Maspin expression along with intratumoral microvessel density, proliferative activity, and p53 status were evaluated immunohistochemically. The incidence of apoptotic cell death was also evaluated.

RESULTS

The incidence of strong maspin expression was significantly higher in lung squamous cell carcinoma (56/76, 73.7%; P < .001) than in other histological types. The incidence of aberrant expression of p53 was significantly higher in maspin-strong than in maspin-weak tumors (56.2% and 35.8%, respectively; P = .005). There was no difference in prognosis according to maspin status for all patients. However, for squamous cell carcinoma patients, univariate analysis showed that enhanced maspin expression was a significant factor in predicting a favorable prognosis (5-year survival rates, 70.1% for maspin-strong tumors and 41.5% for maspin-weak tumors; P = .014), which was confirmed in a multivariate analysis (hazard ratio = .475, 95% confidence interval .241-.936; P = .032).

CONCLUSIONS

Enhanced maspin expression was a significant and independent factor in predicting a favorable prognosis in lung squamous cell carcinoma.

Targeting maspin in endothelial cells to induce cell apoptosis

The diseases of cancer remain as some of the leading causes of death in the industrialised world, although there are a multitude of technologies being used in the field of medical oncology to combat these diseases and scientific research continues to make discoveries to improve patient outcomes. Some of this research has focused on the maspin gene and protein. Maspin is predicted to be a unique serpin with tumour suppressor activity. Recent studies have explored the use of maspin as a therapeutic agent against cancer. In one study, maspin was found to inhibit cancer growth and metastasis in a breast cancer mouse model through a maspin DNA-liposome therapy. A separate study showed the ability of maspin to induce apoptosis in tumour-specific endothelial cells. Taken together, these studies demonstrate the potential use of maspin as a viable anticancer therapeutic agent.

Simultaneous evaluation of maspin and CXCR4 in patients with breast cancer

AIM

To study simultaneously the actions of maspin and CXCR4, which share several similar pathways in cancer, including apoptosis and angiogenesis.

METHODS

Our material consisted of 151 invasive breast carcinomas arranged in a tissue microarray setting. Maspin and CXCR4 expression was evaluated by immunohistochemistry. Microvessel density was assessed by CD34 immunodetection and apoptosis by the Tdt-mediated dUTP nick end labelling assay.

RESULTS

Maspin expression was related to CXCR4 expression, apoptosis, patient age and the Nottingham prognostic index. The expression of both maspin and CXCR4 progressively increased in high-grade tumours. In patients with lymph node negative breast cancer, maspin overexpression was associated with increased risk of death. High CXCR4 expression was associated with prolonged survival of patients with high maspin expression.

CONCLUSIONS

Our results show that maspin overexpression could prove to be a potentially useful marker, especially for the clinically important group of patients with lymph node negative breast cancer. The expression of CXCR4 is of less significance in our study, but may be informative for specific patient subsets or in a longer time frame.

Maspin and tumor metastasis

For most cancer cell types, the acquisition of metastatic activity leads to clinically incurable disease. Improvements in surgery and radiotherapy, and the development of new chemotherapeutic agents or their use in new combinations, have, so far, only incrementally improved patient survival. Despite the obvious importance of metastasis, the process remains incompletely characterized at the molecular and biochemical levels. Tumor metastasis is a complex process and requires multiple cellular functions over time. From cellular invasion, extravasation from the primary tumor, intravasation to the secondary organs, to successful colonization, tumor cells utilize many cellular or biochemical mechanisms to complete the metastatic spread. During the process of metastasis, there are consistent changes in gene expression. Studies of genes that are reduced or silenced have yielded surprising insights into in vivo mechanisms of regulating tumor metastasis. This review describes a tumor suppressor gene, Maspin, which is often silenced in cancer cells and exhibits suppressing activity against tumor growth and metastasis. Maspin has been shown to be involved in processes that are important to both tumor growth and metastasis such as cell invasion, angiogenesis, and more recently apoptosis. Hence, many efforts have been devoted to deciphering the molecular mechanism of maspin. While some insights have come from the protease inhibitory effect of maspin, more perceptive results on how maspin may function in suppressing tumor metastasis have come from studies of gene manipulation, protein interactions and global protein profiling.

Clinicopathological significance of maspin expression in breast cancer

Maspin is a unique serine proteinase inhibitor that has tumor suppressor activity. It has been reported that maspin is expressed in normal human mammary epithelial cells and it is down-regulated during the progression of cancer. However, to date, there is very limited data on the clinical significance of maspin expression in human breast cancer. In this study, maspin expression was assessed immunohistochemically from 80 invasive ductal carcinoma (IDC) specimens of the breast. Also, maspin expression was compared with the clinicopathological factors (age, grade, tumor size and lymph node status), the expression of estrogen receptor (ER), progesterone receptor (PR) and p53, DNA ploidy and the overall survival in an attempt to assess its prognostic value. The maspin expression was positive in 25 IDC cases (31.3%). The maspin expression in IDC was significantly correlated with a higher histologic grade, a larger tumor size, a positive p53 status and shorter survival. There was an inverse association with maspin expression and the PR status. These findings suggest that maspin expression is not down-regulated with the progression of cancer and maspin expression may be associated with a poor prognosis. The immunohistochemical detection of maspin in breast cancers may be helpful for predicting an aggressive phenotype.