Expression and regulation of tumor suppressor gene maspin in breast cancer

Usefulness of Adding Maspin Staining to p53 Staining for EUS-FNA Specimens of Pancreatic Ductal Adenocarcinoma

Background: Endoscopic ultrasound-guided puncture aspiration biopsy (EUS-FNA) of pancreatic ductal adenocarcinoma (PDAC) is highly diagnostic, but it is difficult to distinguish from benign disease. Our objective was to determine the usefulness of maspin staining, in addition to conventional p53 staining, in the diagnosis of PDAC by EUS-FNA. Methods: Of the patients who underwent EUS-FNA and were diagnosed with PDAC, we retrospectively identified 90 cases in which both maspin and p53 staining were performed. In addition, we identified 28 cases of benign pancreatic disease diagnosed using EUS-FNA and these were selected as a control group. For analysis of EUS-FNA specimens, Cohen’s Kappa (κ) coefficient and the prevalence and bias adjusted Kappa statistic (PABAK) were applied to assess the significance of sensitivity and specificity, comparing p53, maspin, p53+maspin. Results: The sensitivity and specificity of p53 staining were 48.9% and 100%. The κ coefficient was 0.31 (95%CI 0.18−0.44) (p < 0.01) and the PABAK coefficient was 0.22 (95%CI 0.03−0.40). The results for maspin staining were 88.9% and 92.9%. The κ coefficient was 0.72 (95%CI 0.54−0.90) (p < 0.01) and the PABAK coefficient was 0.78 (95%CI 0.64−0.88). The results for the combination of maspin and p53 staining were 94.4% and 92.2%. The κ coefficient was 0.82 (95%CI 0.64−1.00) (p < 0.01) and the PABAK coefficient was 0.86 (95%CI 0.74−0.94). Conclusion: Adding maspin staining to p53 staining showed high sensitivity and specificity. Our results demonstrated the usefulness of their combined use that might contribute to the improvement of tissue diagnostic performance of PDAC by EUS-FNA.

Prolonged Administration of Melatonin Ameliorates Liver Phenotypes in Cholestatic Murine Model

BACKGROUND & AIMS

Primary sclerosing cholangitis (PSC) is characterized by biliary senescence and hepatic fibrosis. Melatonin exerts its effects by interacting with Melatonin receptor 1 and 2 (MT1/MT2) melatonin receptors. Short-term (1 wk) melatonin treatment reduces a ductular reaction and liver fibrosis in bile duct-ligated rats by down-regulation of MT1 and clock genes, and in multidrug resistance gene 2 knockout (Mdr2^-/-) mice by decreased miR200b-dependent angiogenesis. We aimed to evaluate the long-term effects of melatonin on liver phenotype that may be mediated by changes in MT1/clock genes/miR200b/maspin/glutathione-S transferase (GST) signaling.

METHODS

Male wild-type and Mdr2^-/- mice had access to drinking water with/without melatonin for 3 months. Liver damage, biliary proliferation/senescence, liver fibrosis, peribiliary inflammation, and angiogenesis were measured by staining in liver sections, and by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay in liver samples. We confirmed a link between MT1/clock genes/miR200b/maspin/GST/angiogenesis signaling by Ingenuity Pathway Analysis software and measured liver phenotypes and the aforementioned signaling pathway in liver samples from the mouse groups, healthy controls, and PSC patients and immortalized human PSC cholangiocytes.

RESULTS

Chronic administration of melatonin to Mdr2^-/- mice ameliorates liver phenotypes, which were associated with decreased MT1 and clock gene expression.

CONCLUSIONS

Melatonin improves liver histology and restores the circadian rhythm by interaction with MT1 through decreased angiogenesis and increased maspin/GST activity.

Maspin differential expression patterns as a potential marker for targeted screening of esophageal adenocarcinoma/gastroesophageal junction adenocarcinoma

AIM

Barrett's esophagus (BE) is a predisposing factor of esophageal adenocarcinoma/gastroesophageal junction adenocarcinoma (ECA/GEJ Aca). BE patients are stratified and subsequently monitored according to the risk of malignant progression by the combination of endoscopy and biopsy. This study is to evaluate the maspin expression patterns as early diagnostic markers of malignancy in BE patients.

MATERIALS AND METHODS

Immunohistochemistry (IHC) staining was performed on 62 archival core biopsies from 35 patients, including BE without dysplasia (intestinal metaplasia, IM), BE with low grade dysplasia, BE with high grade dysplasia, carcinoma in situ, and well to poorly differentiated ECA/GEJ Aca (PD-ECA/GEJ Aca). The intensity and the subcellular distribution of immunoreactivity were evaluated microscopically. Statistical analysis was performed using the χ2 and Fisher exact tests.

RESULTS

The level of epithelial-specific tumor suppressor maspin protein inversely correlated with the progression from IM to PD-ECA/GEJ Aca. Lesions of each pathological grade could be divided into subtypes that exhibited distinct maspin subcellular distribution patterns, including nuclear only (Nuc), combined nuclear and cytoplasmic (Nuc+Cyt), cytoplasmic only (Cyt) and overall negligible (Neg). The Cyt subtype, which was minor in both IM and dysplasia (approximately 10%), was predominant in ECA/GEJ Aca as early as well-differentiated lesions (more than 50%: p = 0.0092). In comparison, nuclear staining of the tumor suppressor TP53 was heterogeneous in dysplasia, and did not correlate with the differentiation grades of ECA/GEJ Aca.

CONCLUSION

The Cyt subtype of maspin expression pattern in core biopsies of BE patients may serve as a molecular marker for early diagnosis of ECA/GEJ Aca.

PTEN PDZ-binding domain suppresses mammary carcinogenesis in the MMTV-PyMT breast cancer model

Phosphatase and tension homolog (PTEN) is a potent tumor suppressor that possesses a PDZ-binding domain (PDZ-BD) at the end of its carboxyl terminus, whose functions during tumorigenesis remains unclear. Here, we crossed a mouse strain with germline deletion of PTEN PDZ-BD with MMTV-PyMT breast cancer model, and found that knockout (KO) mice display normal development of mammary glands, but have both increased breast tumorigenicity and lung metastasis. Orthotopic allograft experiments suggest the loss of PTEN PDZ-BD in breast cancer cells rather than in tumor microenvironment plays a prominent role in increasing tumor burden. Through RNA-sequencing, we observed a significant downregulation of myoepithelial marker genes in both KO primary breast cancer and orthotopic allografts. Moreover, these myoepithelial marker genes are significantly downregulated in human breast cancer tissues, and are associated with poorer clinical prognosis. In addition, several homeobox genes were also identified to be downreguated in KO breast cancer, whose expressions showed significant positive correlation with myoepithelial marker genes. Overall, our findings suggest a novel tumor suppressive role of PTEN PDZ-BD in a murine model of breast cancer, and the mechanism involves the dysregulation of homeobox genes which may result in defective myoepithelial differentiation in breast cancer cells.

The secretion and biological function of tumor suppressor maspin as an exosome cargo protein

Maspin is an epithelial-specific tumor suppressor shown to exert its biological effects as an intracellular, cell membrane-associated, and secreted free molecule. A recent study suggests that upon DNA-damaging g-irradiation, tumor cells can secrete maspin as an exosome-associated protein. To date, the biological significance of exosomal secretion of maspin is unknown. The current study aims at addressing whether maspin is spontaneously secreted as an exosomal protein to regulate tumor/stromal interactions. We prepared exosomes along with cell extracts and vesicle-depleted conditioned media (VDCM) from normal epithelial (CRL2221, MCF-10A and BEAS-2B) and cancer (LNCaP, PC3 and SUM149) cell lines. Atomic force microscopy and dynamic light scattering analysis revealed similar size distribution patterns and surface zeta potentials between the normal cells-derived and tumor cells-derived exosomes. Electron microscopy revealed that maspin was encapsulated by the exosomal membrane as a cargo protein. While western blotting revealed that the level of exosomal maspin from tumor cell lines was disproportionally lower relative to the levels of corresponding intracellular and VDCM maspin, as compared to that from normal cell lines, maspin knockdown in MCF-10A cells led to maspin-devoid exosomes, which exhibited significantly reduced suppressive effects on the chemotaxis activity of recipient NIH3T3 fibroblast cells. These data are the first to demonstrate the potential of maspin delivered by exosomes to block tumor-induced stromal response, and support the clinical application of exosomal maspin in cancer diagnosis and treatment.

BAG3 Overexpression and Cytoprotective Autophagy Mediate Apoptosis Resistance in Chemoresistant Breast Cancer Cells

Target-specific treatment modalities are currently not available for triple-negative breast cancer (TNBC), and acquired chemotherapy resistance is a primary obstacle for the treatment of these tumors. Here we employed derivatives of BT-549 and MDA-MB-468 TNBC cell lines that were adapted to grow in the presence of either 5-Fluorouracil, Doxorubicin or Docetaxel in an aim to identify molecular pathways involved in the adaptation to drug-induced cell killing. All six drug-adapted BT-549 and MDA-MB-468 cell lines displayed cross resistance to chemotherapy and decreased apoptosis sensitivity. Expression of the anti-apoptotic co-chaperone BAG3 was notably enhanced in two thirds (4/6) of the six resistant lines simultaneously with higher expression of HSP70 in comparison to parental controls. Doxorubicin-resistant BT-549 (BT-549^rDOX²⁰) and 5-Fluorouracil-resistant MDA-MB-468 (MDA-MB-468^r5-FU²⁰⁰⁰) cells were chosen for further analysis with the autophagy inhibitor Bafilomycin A1 and lentiviral depletion of ATG5, indicating that enhanced cytoprotective autophagy partially contributes to increased drug resistance and cell survival. Stable lentiviral BAG3 depletion was associated with a robust down-regulation of Mcl-1, Bcl-2 and Bcl-xL, restoration of drug-induced apoptosis and reduced cell adhesion in these cells, and these death-sensitizing effects could be mimicked with the BAG3/Hsp70 interaction inhibitor YM-1 and by KRIBB11, a selective transcriptional inhibitor of HSF-1. Furthermore, BAG3 depletion was able to revert the EMT-like transcriptional changes observed in BT-549^rDOX²⁰ and MDA-MB-468^r5-FU²⁰⁰⁰ cells. In summary, genetic and pharmacological interference with BAG3 is capable to resensitize TNBC cells to treatment, underscoring its relevance for cell death resistance and as a target to overcome therapy resistance of breast cancer.

Upregulation of maspin expression in human cervical carcinoma cells by transforming growth factor β1 through the convergence of Smad and non-Smad signaling pathways

Mammary serine protease inhibitor (maspin), encoded by the serpin family B member 5 gene, serves as a tumor suppressor through the inhibition of cancer cell invasion and metastasis. Paradoxically, maspin levels are upregulated in a number of types of malignant cells. Therefore, the regulation of maspin expression may depend on the genetic or epigenetic background and the specific microenvironment of carcinoma cells. In the present study, it was demonstrated that transforming growth factor β1 (TGF-β1) induced maspin expression at the transcript and protein levels in the human cervical carcinoma HeLa and human oral squamous carcinoma HSC4 cell lines. The inhibition of the mothers against decapentaplegic homolog (Smad)-dependent pathway by a Smad3-specific inhibitor suppressed maspin induction by TGF-β1 in HeLa cells. Inhibition of the non-Smad pathway by pretreatment with the mitogen-activated protein kinase kinase 1/2 (MEK1/2) inhibitor U0126, or the p38 mitogen-activated protein kinase (p38 MAPK) inhibitor SB202190, attenuated the effect of TGF-β1 on maspin upregulation, whereas pretreatment with pyrrolidine dithiocarbamate (a nuclear factor κB inhibitor), wortmannin (a phosphoinositide 3-kinase inhibitor) or SP600125 (a c-Jun N-terminal kinase inhibitor) did not. Notably, none of these inhibitors eliminated the TGF-β1-induced phosphorylation of Smad2. In addition, mutations at p53-binding sites in the maspin promoter suppressed TGF-β1-induced maspin expression, indicating the necessity of intact p53-binding sites on the maspin promoter. In summary, the induction of maspin expression in HeLa cells requires the convergence of TGF-β1-induced Smad and non-Smad signaling pathways, in which the latter acts via the intermediate signaling molecules MEK1/2 and p38 MAPK.

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.

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.

An emerging role for the nuclear localization of maspin in the suppression of tumor progression and metastasis

Maspin, a member of the serpin family of serine protease inhibitors, was originally identified as a tumor suppressor that is expressed in normal mammary epithelial cells but is reduced or absent in breast carcinomas. Early enthusiasm for maspin as a biomarker for disease progression has been tempered by clinical data that associates maspin with favourable outcomes in some studies and poor prognosis in others. Here, we review all of the published clinical studies for maspin in breast and ovarian cancers and propose that the apparent discordance between clinical reports is a consequence of differential cellular distribution of maspin. Indeed, it was thought that an extracellular pool of maspin possessed tumor suppressor activity, acting by inhibiting migration and increasing cell adhesion. Recent evidence from our group and others indicates, however, that the nuclear localization of maspin in cancer cells is necessary for its tumor suppressor activity. We provide additional data here to demonstrate that nuclear-localized maspin binds to chromatin and is required to effectively prevent cells from metastasizing. Our knowledge of other serpins that localize to the nucleus should help to inform future studies of nuclear maspin. Elucidation of the molecular mechanisms regulating the localization and activities of maspin should pave the way for the development of improved diagnostics and therapies for cancer.

Distinctive localization and opposed roles of vasohibin-1 and vasohibin-2 in the regulation of angiogenesis

We recently isolated a novel angiogenesis inhibitor, vasohibin-1, and its homologue, vasohibin-2. In this study we characterize the role of these 2 molecules in the regulation of angiogenesis. In a mouse model of subcutaneous angiogenesis, the expression of endogenous vasohibin-1 was low in proliferating ECs at the sprouting front but high in nonproliferating endothelial cells (ECs) in the termination zone. In contrast, endogenous vasohibin-2 was preferentially expressed in mononuclear cells mobilized from bone marrow that infiltrated the sprouting front. When applied exogenously, vasohibin-1 inhibited angiogenesis at the sprouting front where endogenous vasohibin-1 was scarce but did not influence vascularity in the termination zone where endogenous vasohibin-1 was enriched. Exogenous vasohibin-2 prevented the termination of angiogenesis in the termination zone and increased vascularity in this region. Angiogenesis was persistent in the termination zone in the vasohibin-1 knockout mice, whereas angiogenesis was deficient at the sprouting front in the vasohibin-2 knockout mice. Supplementation of deficient proteins normalized the abnormal patterns of angiogenesis in the vasohibin knockout mice. These results indicate that vasohibin-1 is expressed in ECs in the termination zone to halt angiogenesis, whereas vasohibin-2 is expressed in infiltrating mononuclear cells in the sprouting front to promote angiogenesis.

Expression of nm23 in the spectrum of pre-invasive, invasive and metastatic breast lesions

Background

Nm23 protein is a metastasis suppressor protein, expressed in all tissues. Reduced Nm23 expression is related to a high incidence of lymph node and distant metastasis and poor prognosis in patients with cancers. The present study was done to analyze the expression of Nm23 using immunohistochemistry in non-neoplastic and neoplastic breast lesions.

Methods

Sections from 93 samples were studied and classified into non-proliferative breast lesion (13), fibrodenoma (7), proliferative breast lesion (13), carcinoma in situ (20), invasive carcinoma (23) and metastatic deposits in lymph nodes (17).

Results

Nm23 expression in these groups showed a progressive down regulation with increasing neoplastic transformation. On comparing the various groups, nm23 expression was significantly different between the various subgroups with greatest expression in non-proliferative lesions and least in metastatic deposits (p < 0.050).

Conclusion

It is concluded that the modulation of nm23 in a spectrum of breast lesions can be indicative of metastatic phenotype and help to predict the aggressiveness of disease.

The role of osteopontin in tumor progression and metastasis in breast cancer

The use of cancer biomarkers to anticipate the outlines of disease has been an emerging issue, especially as cancer treatment has made such positive steps in the last few years. Progress in the development of consistent malignancy markers is imminent because advances in genomics and bioinformatics have allowed the examination of immense amounts of data. Osteopontin is a phosphorylated glycoprotein secreted by activated macrophages, leukocytes, and activated T lymphocytes, and is present in extracellular fluids, at sites of inflammation, and in the extracellular matrix of mineralized tissues. Several physiologic roles have been attributed to osteopontin, i.e., in inflammation and immune function, in mineralized tissues, in vascular tissue, and in kidney. Osteopontin interacts with a variety of cell surface receptors, including several integrins and CD44. Binding of osteopontin to these cell surface receptors stimulates cell adhesion, migration, and specific signaling functions. Overexpression of osteopontin has been found in a variety of cancers, including breast cancer, lung cancer, colorectal cancer, stomach cancer, ovarian cancer, and melanoma. Moreover, osteopontin is present in elevated levels in the blood and plasma of some patients with metastatic cancers. Therefore, suppression of the action of osteopontin may confer significant therapeutic activity, and several strategies for bringing about this suppression have been identified. This review looks at the recent advances in understanding the possible mechanisms by which osteopontin may contribute functionally to malignancy, particularly in breast cancer. Furthermore, the measurement of osteopontin in the blood or tumors of patients with cancer, as a way of providing valuable prognostic information, will be discussed based on emerging clinical data.

Double immunohistochemical staining with MUC4/p53 is useful in the distinction of pancreatic adenocarcinoma from chronic pancreatitis: a tissue microarray-based study

CONTEXT

Immunohistochemical stains have been used for the distinction of pancreatic adenocarcinoma from chronic pancreatitis.

OBJECTIVE

To determine if a double stain for MUC/p53 improved specificity and sensitivity for distinction of pancreatic adenocarcinoma from chronic pancreatitis by comparing maspin, mucin 4 (MUC4), p53, Smad4, and the double stain MUC4/p53.

DESIGN

Seventy-four pancreatic adenocarcinomas and 19 chronic pancreatitis cases were retrieved from archival files. Tissue cores were arrayed to create a tissue microarray of 2-mm cores. Sections were stained with antibodies against maspin, MUC4, p53, and Smad4. Additionally, a 2-color, double stain for MUC4 and p53 was developed and evaluated. Five percent or greater staining in either of the cores was considered positive. Intensity (0, 1, 2) and extent (%) of tumor cells staining was also determined.

RESULTS

The sensitivity for distinction of pancreatic adenocarcinoma from chronic pancreatitis with maspin, MUC4, p53, and Smad4 was 90%, 77%, 60%, and 63%, respectively; the specificity was 67%, 78%, 88%, and 88%, respectively. When MUC4 and p53 were combined in a double stain, and positive staining for either considered a positive result, the sensitivity increased to 96% but specificity was 73%. When immunoreactivity for both antibodies was necessary for a positive result, sensitivity fell to 39% but specificity was 100%. No correlation was found between intensity or extent of staining with any of the individual stains and tumor differentiation.

CONCLUSION

The double immunohistochemical stain for MUC4/p53 can be a useful diagnostic tool in conjunction with the hematoxylin-eosin-stained section for pancreatic adenocarcinoma, particularly when limited tumor is available for multiple stains.

Maspin is Useful in the Distinction of Pancreatic Adenocarcinoma From Chronic Pancreatitis

Maspin, a member of the serpin family of serine protease inhibitors, has been shown to limit invasion and metastases in breast and prostate carcinomas. Maspin gene expression is up-regulated in pancreatic cancer, but not in normal pancreatic tissue. Maspin expression has been documented using immunohistochemical studies in pancreatic adenocarcinoma and high-grade intraductal dysplasia. We studied pancreatic ductal adenocarcinomas and chronic pancreatitis utilizing tissue microarray technology to determine the utility of maspin in differentiating these lesions. Immunohistochemistry was performed on tissue microarrays made from 72 cases of pancreatic ductal adenocarcinoma and 24 cases of chronic pancreatitis. Carcinomas were graded as well, moderately, or poorly differentiated using the WHO criteria. The primary antibody used was monoclonal antimaspin antibody (clone G167-70, 1:800, PharMingen, San Diego, CA). Nuclear and/or cytoplasmic staining for maspin was qualitatively scored from 1 + to 3 + based on intensity. Cases were considered positive if one or more cores demonstrated staining. Cases of chronic pancreatitis showed focal, weak (1 + to 2 +) staining within occasional benign ductal epithelial cells in 29% of cases (7/24). Diffuse and intense (3 +) staining was present in ducts with squamous metaplasia (3 cases). The majority of ducts showed no staining. Ductal adenocarcinomas showed diffuse staining in 91% (66/72) of cases with generally more intense staining than cases of chronic pancreatitis. Maspin may be helpful in differentiating ductal adenocarcinoma from chronic pancreatitis, once squamous metaplasia is ruled out.

Evaluation of sphinganine and sphingosine as human breast cancer chemotherapeutic and chemopreventive agents

No comparative study of the effects of sphingolipid metabolites on proliferation and differentiation in normal human breast epithelial cells versus stem cells and tumorigenic cells has been reported. The purpose of this study was to evaluate the chemotherapeutic and chemopreventive potential of sphingoid bases (sphingosine and sphinganine) using a novel cell culture system of normal human breast epithelial cells (HBEC) developed from breast tissues of healthy women obtained during reduction mammoplasty (Type I HBEC with stem cell characteristics and Type II HBEC with basal epithelial cell phenotypes) and transformed tumorigenic Type I HBEC. The results show that sphinganine inhibited the growth and induced apoptosis of transformed tumorigenic Type I HBEC more potently than sphingosine (IC(50) for sphinganine 4 microM; sphingosine 6.4 microM). Both sphinganine and sphingosine at high concentrations (8-10 lM) arrested the cell cycle at G(2)/M. Sphinganine inhibited the growth and caused death of Type I HBEC more strongly than sphingosine. In comparison, Type II HBEC (normal differentiated cells) were less sensitive to the growth-inhibitory effects of sphingoid bases than Type I HBEC (stem cells) or transformed tumorigenic Type I HBEC, suggesting that sphingoid bases may serve as chemotherapeutic agents. At concentrations (0.05, 0.1, and 0.5 microM) that are below the growth-inhibitory range, sphingoid bases induced differentiation of Type I HBEC to Type II HBEC, as detected morphologically and via expression of a tumor suppressor protein, maspin, which is a marker of Type II HBEC. Thus, sphingoid bases may function as chemotherapeutic as well as chemopreventive agents by preferentially inhibiting cancer cells and eliminating stem cells from which most breast cancer cells arise.

Nuclear and cytoplasmic Maspin expression in primary non-small cell lung cancer

AIM

To investigate whether nuclear and cytoplasmic Maspin expression is associated with distinct clinicopathological parameters and TP53 expression in a representative series of primary non-small cell lung cancer (NSCLC).

METHODS

Tissue microarrays (n=487) were used to immunohistochemically analyse expression of Maspin and TP53. Cytoplasmic and nuclear expression of Maspin was scored on the basis of the percentage of positive tumour cells. Univariate analysis of clinicopathological variables potentially affecting tumour-specific survival was performed.

RESULTS

Immunohistochemical Maspin expression (nuclear and cytoplasmic) was informative in 72.3% (352/487) of cases. Cytoplasmic and nuclear Maspin immunoreactivity in >or=10% of tumour cells was detected in 37.8% (133/352) and 65.3% (230/352) of informative cases, respectively. Nuclear and cytoplasmic Maspin staining was observed more frequently in primary squamous cell carcinomas than in other lung cancer types. Only nuclear Maspin immunoreactivity was significantly associated with positive TP53 staining. Cytoplasmic or nuclear Maspin expression was not associated with tumour-specific survival.

CONCLUSION

Maspin expression was found both in the nucleus and the cytoplasm of NSCLC, more frequently in squamous cell carcinomas. However, no association with tumour-specific survival could be demonstrated.

Nuclear Maspin expression is associated with response to adjuvant 5-fluorouracil based chemotherapy in patients with stage III colon cancer

Maspin, a member of the Serpin protease inhibitor family, is overexpressed in poorly differentiated colorectal tumors and more frequently found in tumors with microsatellite instability. Immunohistochemical nuclear Maspin staining is predominantly seen in tumor cells at the invasion front of such cancers, suggesting that this molecule is associated with local tumor cell infiltration and aggressiveness. In a retrospective study, we studied nuclear Maspin expression as a potential prognostic tool in a total of 172 primary stage III colon cancers by immunohistochemistry. Of those 172 patients, 76 were treated by surgery only, and 96 patients received additional adjuvant 5-fluorouracil (5-FU) based chemotherapy. Nuclear Maspin expression was an independent adverse prognostic factor for overall survival in our patient cohort (hazard ratio 2.08; 95% CI, 1.13-3.81; p = 0.018). However, patients with primary tumors expressing Maspin in the nucleus showed a significant treatment benefit from 5-FU chemotherapy (hazard ratio 0.384; 95% CI, 0.188-0.784; p = 0.009) compared to adjuvantly treated patients whose tumors did not express this molecule. Nuclear Maspin expression is highly predictive of 5-FU chemotherapy response in patients with advanced stage colon cancer. Patients with negative immunohistochemical Maspin expression do not benefit from 5-FU treatment and may be candidates for an alternative (non-5-FU based) adjuvant therapy regime.

Maspin expression in CIN 3, microinvasive squamous cell carcinoma, and invasive squamous cell carcinoma of the uterine cervix

Maspin is a serine protease inhibitor with tumor suppression activity. It is expressed in normal breast and prostate tissue but is downregulated or absent in breast and prostate tumors. Recent reports have shown that decreased expression is associated with a greater propensity for metastasis in oral squamous cell carcinomas. We know that some high-grade cervical intraepithelial neoplasia progress to invasive carcinomas while others either persist at the same degree of atypia or regress. The pattern of maspin expression in cervical intraepithelial neoplasia-grade 3, microinvasive squamous carcinomas and overtly invasive squamous cell carcinomas of the uterine cervix was studied to determine the relationship between the extent of maspin expression and the progression of cervical intraepithelial neoplasia to squamous cell carcinoma. In total, 36 cases were evaluated: 18 cases of cervical intraepithelial neoplasia-grade 3, seven cases of microinvasive squamous cell carcinoma and 11 cases of invasive squamous cell carcinoma. A monoclonal antibody was used on paraffin-embedded tissues. Immunoreactivity was scored semiquantitatively using a scale of 0-3. The sums of the scores of the different groups were compared using the Mann-Whitney U-test. A significant decrease in maspin scores was noted between cervical intraepithelial neoplasia-grade 3 vs invasive squamous cell carcinoma (P<0.005), microinvasive squamous cell carcinoma vs invasive squamous cell carcinoma (P<0.05), and cervical intraepithelial neoplasia-grade 3 vs tumor emboli (P<0.005). Although not statistically significant, scores of cervical intraepithelial neoplasia-grade 3 associated with invasive squamous cell carcinoma were lower compared to that cervical intraepithelial neoplasia-grade 3 without invasive squamous cell carcinoma. These findings suggest that maspin likely plays a role in disease progression from in situ to invasive carcinoma. Virtual absence of maspin immunopositivity in tumor emboli indicates that maspin may also play a role in metastasis.

Elevated nuclear maspin expression is associated with microsatellite instability and high tumour grade in colorectal cancer

Maspin, a member of the serpin family, has been reported to suppress metastasis and angiogenesis in breast and prostate cancers. Overexpression of maspin was associated with adverse prognostic features in several other tumours. In this study, expression of maspin was analysed in 41 colorectal carcinomas with high-frequency microsatellite instability (MSI-H) and 159 microsatellite stable colorectal cancers (MSS/MSI-L) by immunohistochemistry (IHC) and partly by relative quantitative real-time RT-PCR and western blot analyses. Significant upregulation of maspin expression was found in MSI-H tumours compared to both MSS/MSI-L tumours and matched benign colonic mucosa. Increased maspin expression was also found in three MSI-H colon cancer cell lines, but not in three MSS colon cancer cell lines by RT-PCR and western blot analyses. Regulation of maspin expression depended on promoter methylation as tissue specimens and cell lines expressing maspin showed unmethylated maspin promoters, whereas promoter hypermethylation was found in specimens with loss of maspin expression. Intense nuclear maspin immunostaining was seen specifically in MSI-H tumours (p = 0.013), de-differentiated tumours (p = 0.006), and at the invasion front. These findings provide new insights into the role of maspin in colorectal cancer progression and may be useful for diagnosis and treatment strategies.

Workshop on Cancer Biometrics: Identifying Biomarkers and Surrogates of Cancer in Patients

The current excitement about molecular targeted therapies has driven much of the recent dialog in cancer diagnosis and treatment. Particularly in the biologic therapy of cancer, identifiable antigenic T-cell targets restricted by MHC molecules and the related novel stress molecules such as MICA/B and Letal allow a degree of precision previously unknown in cancer therapy. We have previously held workshops on immunologic monitoring and angiogenesis monitoring. This workshop was designed to discuss the state of the art in identification of biomarkers and surrogates of tumor in patients with cancer, with particular emphasis on assays within the blood and tumor. We distinguish this from immunologic monitoring in the sense that it is primarily a measure of the tumor burden as opposed to the immune response to it. Recommendations for intensive investigation and targeted funding to enable such strategies were developed in seven areas: genomic analysis; detection of molecular markers in peripheral blood and lymph node by tumor capture and RT-PCR; serum, plasma, and tumor proteomics; immune polymorphisms; high content screening using flow and imaging cytometry; immunohistochemistry and tissue microarrays; and assessment of immune infiltrate and necrosis in tumors. Concrete recommendations for current application and enabling further development in cancer biometrics are summarized. This will allow a more informed, rapid, and accurate assessment of novel cancer therapies.

Mammaglobin Expression in Leukapheresis Products Is a Predictive Marker of Poor Prognosis in Women with High-Risk Breast Cancer

PURPOSE

The purpose of this study was to investigate the incidence and prognostic relevance of tumor cell detection in granulocyte colony-stimulating factor-mobilized peripheral blood progenitor cell collections (PBPCCs) using cytokeratin (CK), maspin (MAS), and mammaglobin (MAM) genes as epithelial cell markers. The population on which the study was conducted was drawn from stage III breast cancer patients undergoing high-dose chemotherapy and autologous transplantation with PBPCCs.

EXPERIMENTAL DESIGN

One hundred and ninety-four patients were enrolled in the study and analyzed for tumor cell detection on the basis of 481 PBPCCs gathered before administration of chemotherapy. CK, MAS, and MAM gene expressions were investigated by means of the reverse transcription nested polymerase chain reaction, and those samples expressing CK were further hybridized with a radiolabeled internal probe to reduce false-positive results. Sensitivity and specificity were assessed on 37 controls (12 cell lines, 12 healthy donors, and 13 nonepithelial malignancies). Each of the known prognostic variables (age, stage, lymph node status, receptor status, c-ErbB2 status, and Ki67 status) was then analyzed (both individually and together with CK, MAS, and MAM expression on PBPCCs) in relation to patient overall survival (OS) and relapse-free survival (RFS).

RESULTS

After a 3-year follow-up, an estimated 83% (95% confidence interval, 77.1-88.8%) of the patients were alive and an estimated 67% (95% confidence interval, 60.1-74.6%) were free of relapse. One hundred and seventy-six of the 194 patients (91%) had contaminated PBPCCs evidenced by at least one positive sample for any of the markers evaluated. The PBPCC frequency of CK, MAS, and MAM positivity (+) was 71%, 36%, and 16%, respectively. MAM expression on PBPCC was associated with an increased risk of relapse (P = 0.003), whereas CK and MAS expressions were not associated with changes in either RFS or OS.

CONCLUSIONS

MAM gene expression on leukapheresis products of high-risk breast cancer patients is an indicator of poor prognosis. The method of evaluation is simple and reproducible and provides new tools for evaluating the role played by tumor cells in apheresis products and their potential in causing metastasis.

Molecular Characterization of the Transition to Malignancy in a Genetically Engineered Mouse-Based Model of Ductal Carcinoma In situ

A transplantable model of human ductal carcinoma in situ that progresses to invasive carcinoma was developed from a genetically engineered mouse (GEM). Additional lines were established using early mammary premalignant lesions from transgenic MMTV-PyV-mT mice. These lines were verified to be premalignant and transplanted repeatedly to establish stable and predictable properties. Here, we report the first in-depth molecular analysis of neoplastic progression occurring in one premalignant transplantable GEM-derived line. Oligonucleotide microarrays showed that many genes are differentially expressed between the quiescent and prelactating mammary gland and the premalignant GEM outgrowth. In contrast, a small but consistent group of genes was associated with the transformation from premalignancy to tumor. This suggests that the majority of gene expression changes occur during the premalignant transition from normal to premalignancy, whereas many fewer changes occur during the malignant transition from premalignancy to invasive carcinoma. The premalignant transition is associated with several cell cycle–related genes and the up-regulation of oncogenes is associated with various cancers (Ccnd11, Cdk4, Myb, and Ect2). The changes identified in the malignant transition included genes previously associated with human breast cancer progression. Misregulation of the insulin-like growth factor and transforming growth factor-β signaling pathways and the stromal-epithelial interaction were implicated. Our results suggest that this transplantable GEM-based model recapitulates human ductal carcinoma in situ at both histologic and molecular levels. With consistent tumor latency and molecular profiles, this model provides an experimental platform that can be used to assess functional genomics and molecular pharmacology and to test promising chemoprevention strategies.

Breast cancer biomarkers and molecular medicine

The first part of this two-part review of established and emerging breast cancer biomarkers and molecular diagnostics considers breast cancer predisposition, screening tests for diagnosis, diagnosis using small specimens and metastatic lesions, micrometastatic disease and breast cancer prognosis assessment. Prognostic factors covered in this review include: cytogenetic markers, DNA ploidy and S phase determination, cell proliferation markers, cell cycle regulators and growth factor measurements including epithelial growth factor receptor, HER-2/neu and a variety of other relevant molecules controlling proliferation, differentiation and angiogenesis. The first section of part two will continue the consideration of breast cancer prognostic factors including oncogenes, tumor suppressor genes, cell adhesion molecules, invasion-associated proteins and proteases, hormone receptor proteins, drug resistance proteins, apoptosis regulators, transcription factors, telomerase, DNA repair and methylation and transcriptional profiling using high-density genomic microarrays. The second section of part two will consider the prediction of therapy response using the techniques of pharmacogenetics and pharmacogenomics.

Expression and regulation of tumor suppressor gene maspin in human bladder cancer

Maspin is a member of serine protease inhibitor family with tumor suppressing activity for breast and prostate cancers, acting at the level of tumor invasion and metastasis. However, there have been no published data regarding the role of maspin in human bladder cancer. We evaluated maspin expression in 65 series of bladder cancer samples (22 transurethral resection (TUR) and 43 radical cystectomy) and studied the regulatory mechanism of maspin gene activation in bladder cancer cells. Maspin expression was immunohistochemically detected in four (18.2%) patients with TUR and 22 (51.2%) patients with radical cystectomy whereas no expression was observed in normal transitional cells located at tumor-free area in bladder. The maspin expression was significantly correlated with the development of muscle invasive bladder cancer (P=0.00008). Using a luciferase reporter system, maspin promoter activity was induced in the maspin-positive bladder cancer cell lines as well as maspin-negative RT4 cells. Furthermore, treatment with the DNA methyltransferase inhibitor, 5-aza-2' deoxycytidine, and histone deacetylase inhibitor, trichostatin A, led to re-expression of maspin in RT4 cells. Our results indicate that maspin may contribute to bladder cancer development and that DNA methylation and histone deacetylation may be important for regulating maspin gene activation in bladder cancer cells.