Prognostic significance of alpha-1-antitrypsin in early stage of colorectal carcinomas

An integrated framework for prognosis prediction and drug response modeling in colorectal liver metastasis drug discovery

BACKGROUND

Colorectal cancer (CRC) is the third most prevalent cancer globally, and liver metastasis (CRLM) is the primary cause of death. Hence, it is essential to discover novel prognostic biomarkers and therapeutic drugs for CRLM.

METHODS

This study developed two liver metastasis-associated prognostic signatures based on differentially expressed genes (DEGs) in CRLM. Additionally, we employed an interpretable deep learning model utilizing drug sensitivity databases to identify potential therapeutic drugs for high-risk CRLM patients. Subsequently, in vitro and in vivo experiments were performed to verify the efficacy of these compounds.

RESULTS

These two prognostic models exhibited superior performance compared to previously reported ones. Obatoclax, a BCL-2 inhibitor, showed significant differential responses between high and low risk groups classified by prognostic models, and demonstrated remarkable effectiveness in both Transwell assay and CT26 colorectal liver metastasis mouse model.

CONCLUSIONS

This study highlights the significance of developing specialized prognostication approaches and investigating effective therapeutic drugs for patients with CRLM. The application of a deep learning drug response model provides a new drug discovery strategy for translational medicine in precision oncology.

SERPINA3: Stimulator or Inhibitor of Pathological Changes

SERPINA3, also called α-1-antichymotrypsin (AACT, ACT), is one of the inhibitors of serine proteases, one of which is cathepsin G. As an acute-phase protein secreted into the plasma by liver cells, it plays an important role in the anti-inflammatory response and antiviral response. Elevated levels of SERPINA3 have been observed in heart failure and neurological diseases such as Alzheimer's disease or Creutzfeldt-Jakob disease. Many studies have shown increased expression levels of the SERPINA3 gene in various types of cancer, such as glioblastoma, colorectal cancer, endometrial cancer, breast cancer, or melanoma. In this case, the SERPINA3 protein is associated with an antiapoptotic function implemented by adjusting the PI3K/AKT or MAPK/ERK 1/2 signal pathways. However, the functions of the SERPINA3 protein are still only partially understood, mainly in the context of cancerogenesis, so it seems necessary to summarize the available information and describe its mechanism of action. In particular, we sought to amass the existing body of research focusing on the description of the underlying mechanisms of various diseases not related to cancer. Our goal was to present an overview of the correct function of SERPINA3 as part of the defense system, which unfortunately easily becomes the "Fifth Column" and begins to support processes of destruction.

Serpin family A member 1 is an oncogene in glioma and its translation is enhanced by NAD(P)H quinone dehydrogenase 1 through RNA-binding activity

Serpin family A member 1 (SERPINA1) is expressed abundantly in gliomas and can predict unfavorable prognosis of patients with glioma. Studies have shown that nicotinamide adenine dinucleotide phosphate quinone dehydrogenase 1 (NQO1) can promote the proliferation of glioblastoma multiforme cells and enhance the expression of SERPINA1, but its effects on glioma cells remain unknown. In this study, we explored the functions of SERPINA1 in glioma tumorigenesis in vitro and then investigated whether NQO1 affects the protein expression of SERPINA1 and its mRNA level. The results showed that the translation of SERPINA1 was suppressed while its mRNA level had no significant changes under the condition of NQO1 silencing. Luciferase reporter assay and biotin pull-down assay further indicated that NQO1 bond with SERPINA1 3′ untranslated region. miR-1321 was also identified to target SERPINA1, repressing its mRNA and protein levels. SERPINA1 and NQO1 promoted glioma cell proliferation and suppressed cell apoptosis. Moreover, SERPINA1 rescued the effects of sh-NQO1 in glioma cell malignant phenotypes. In conclusion, our findings showed that oncogene NQO1 and antioncogene miR-1321 bind to oncogene SERPINA1 to affect proliferation and apoptosis of glioma cells, which can bring new solution of antitumor treatments for glioma in the future.

Integrated weighted gene co-expression network analysis reveals biomarkers associated with prognosis of high-grade serous ovarian cancer

Background

Ovarian cancer is the gynecologic tumor with the highest fatality rate, and high‐grade serous ovarian cancer (HGSOC) is the most common and malignant type of ovarian cancer. One important reason for the poor prognosis of HGSOC is the lack of effective diagnostic and prognostic biomarkers. New biomarkers are necessary for the improvement of treatment strategies and to ensure appropriate healthcare decisions.

Methods

To construct the co‐expression network of HGSOC samples, we applied weighted gene co‐expression network analysis (WGCNA) to assess the proteomic data obtained from the Clinical Proteomic Tumor Analysis Consortium (CPTAC), and module‐trait relationship was then analyzed and plotted in a heatmap to choose key module associated with HGSOC. Subsequently, hub genes with high connectivity in key module were identified by Cytoscape software. Furthermore, the biomarkers were selected through survival analysis, followed by evaluation using the relative operating characteristic (ROC) analysis.

Results

A total of 9 modules were identified by WGCNA, and module‐trait analysis revealed that the brown module was significantly associated with HGSOC (cor = 0.7). Ten hub genes with the highest connectivity were selected by protein‐protein interaction analysis. After survival and ROC analysis, ALB, APOB and SERPINA1 were suggested to be the biomarkers, and their protein levels were positively correlated with HGSOC prognosis.

Conclusion

We conducted the first gene co‐expression analysis using proteomic data from HGSOC samples, and found that ALB, APOB and SERPINA1 had prognostic value, which might be applied for the treatment of HGSOC in the future.

Definition of an Inflammatory Biomarker Signature in Plasma-Derived Extracellular Vesicles of Glioblastoma Patients

Glioblastoma (GB) is an aggressive type of tumour for which therapeutic options and biomarkers are limited. GB diagnosis mostly relies on symptomatic presentation of the tumour and, in turn, brain imaging and invasive biopsy that can delay its diagnosis. Description of easily accessible and effective biomarkers present in biofluids would thus prove invaluable in GB diagnosis. Extracellular vesicles (EVs) derived from both GB and stromal cells are essential to intercellular crosstalk in the tumour bulk, and circulating EVs have been described as a potential reservoir of GB biomarkers. Therefore, EV-based liquid biopsies have been suggested as a promising tool for GB diagnosis and follow up. To identify GB specific proteins, sEVs were isolated from plasma samples of GB patients as well as healthy volunteers using differential ultracentrifugation, and their content was characterised through mass spectrometry. Our data indicate the presence of an inflammatory biomarker signature comprising members of the complement and regulators of inflammation and coagulation including VWF, FCGBP, C3, PROS1, and SERPINA1. Overall, this study is a step forward in the development of a non-invasive liquid biopsy approach for the identification of valuable biomarkers that could significantly improve GB diagnosis and, consequently, patients’ prognosis and quality of life.

Identification and characterization of non-small cell lung cancer associated sialoglycoproteins

Aberrantly sialylated cellular glycoconjugates were found to be involved in different processes during tumorigenesis. Such alteration was also noted in case of lung cancer, an important cause of cancer-related death throughout the world. Thus, study on lung cancer associated sialoglycoproteins is of paramount relevance to have a deeper insight into the mechanism of the disease pathogenesis. In the present study, sialic acid specific lectin (Maackia amurensis agglutinin and Sambcus nigra agglutinin)-based affinity chromatography followed by 2D-PAGE and MALDI-TOF/TOF mass spectrometric analysis were done to explore the disease-associated serum proteins of squamous cell carcinoma and adenocarcinoma [the major two subtypes of NSCLC (non-small cell lung carcinoma)] patients. Among seven identified proteins, α1-antitrypsin and haptoglobin-β were preferred for further studies. These two proteins were characterized as the disease associated serum-sialoglycoproteins of NSCLC-patients by western immunoblotting using each lectin specific inhibitor. The presence of these sialoglycoproteins was found on NSCLC cell lines (NCI-H520 & A549) by confocal microscopy. Both these proteins were also present in tissue samples of NSCLC origin and involved in proliferation, invasion and migration of NSCLC cells. Our findings suggest that α1-antitrypsin and haptoglobin-β may be the disease-associated sialoglycoproteins in NSCLC, which seem to be involved in disease progression. SIGNIFICANCE: Our contribution regarding the identification of the NSCLC associated sialoglycoproteins may provide a new vision towards the development of clinically useful newer strategies for the treatment of this disease.

Overexpression of SERPINA3 promotes tumor invasion and migration, epithelial-mesenchymal-transition in triple-negative breast cancer cells

Background

Recent studies have indicated that serpin peptidase inhibitor, clade A, member 3 (SERPINA3) is a potential marker associated with tumor progression, which connoted that SERPINA3 is related to malignant phenotypes in cancer. However, the biological function of SERPINA3 in breast cancer (BC) remains unclear.

Methods

Bioinformatics data were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Immunohistochemical staining (IHC) was conducted to determine SERPINA3 expression. With strong aggressive abilities, triple-negative breast cancer (TNBC) cell lines (MDA-MB-231, BT549 and MDA-MB-436) were obtained to examine SERPINA3 expression and functions. Wound healing and Transwell assays were performed to measure cell migration and invasion. Cell Counting Kit-8 (CCK-8) assay was conducted to detect cell proliferation abilities and cell viabilities.

Results

SERPINA3 was upregulated in BC tissues. Functional assays suggested that overexpression of SERPINA3 significantly promoted cell proliferation, where migration and invasion of TNBC cells were accelerated. Knockdown of SERPINA3 had the opposite effects. These results causing by overexpression of SERPINA3 were also confirmed in non-TNBC cell lines. Overexpression of SERPINA3 remarkably enhanced the epithelial–mesenchymal transition (EMT) by upregulating the EMT markers and EZH2. In addition, the overexpression of SERPINA3 reduced the sensitivity of TNBC cells to cisplatin.

Conclusion

SERPINA3 can regulate the migration, invasion and EMT of TNBC cells and increased expression of SERPINA3 confers resistance to cisplatin in TNBC cells. We discern it is required for the regulation of BC progression and is a critical target for the clinical treatment of BC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12282-021-01221-4.

A Meta-Analysis of Proteomic Blood Markers of Colorectal Cancer

BACKGROUND

Early diagnosis will significantly improve the survival rate of colorectal cancer (CRC); however, the existing methods for CRC screening were either invasive or inefficient. There is an emergency need for novel markers in CRC's early diagnosis. Serum proteomics has gained great potential in discovering novel markers, providing markers that reflect the early stage of cancer and prognosis prediction of CRC. In this paper, the results of proteomics of CRC studies were summarized through a meta-analysis in order to obtain the diagnostic efficiency of novel markers.

METHODS

A systematic search on bibliographic databases was performed to collect the studies that explore blood-based markers for CRC applying proteomics. The detection and validation methods, as well as the specificity and sensitivity of the biomarkers in these studies, were evaluated. Newcastle- Ottawa Scale (NOS) case-control studies version was used for quality assessment of included studies.

RESULTS

Thirty-four studies were selected from 751 studies, in which markers detected by proteomics were summarized. In total, fifty-nine proteins were classified according to their biological function. The sensitivity, specificity, or AUC varied among these markers. Among them, Mammalian STE20-like protein kinase 1/ Serine threonine kinase 4 (MST1/STK4), S100 calcium-binding protein A9 (S100A9), and Tissue inhibitor of metalloproteinases 1 (TIMP1) were suitable for effect sizes merging, and their diagnostic efficiencies were recalculated after merging. MST1/STK4 obtained a sensitivity of 68% and a specificity of 78%. S100A9 achieved a sensitivity of 72%, a specificity of 83%, and an AUC of 0.88. TIMP1 obtained a sensitivity of 42%, a specificity of 88%, and an AUC of 0.71.

CONCLUSION

MST1/STK4, S100A9, and TIMP1 showed excellent performance for CRC detection. Several other markers also presented optimized diagnostic efficacy for CRC early detection, but further verification is still needed before they are suitable for clinical use. The discovering of more efficient markers will benefit CRC treatment.

Exome sequencing identifies a recurrent variant in SERPINA3 associating with hereditary susceptibility to breast cancer

BACKGROUND

Breast cancer is strongly influenced by hereditary risk factors. Yet, the known susceptibility genes and genomic loci explain only about half of the familial component of the disease. To identify novel breast cancer predisposing gene defects, here we have performed massive parallel sequencing for Northern Finnish breast cancer cases.

METHODS

Ninety-eight breast cancer cases with indication of hereditary disease susceptibility were exome sequenced. Data filtering strategy focused on predictably deleterious rare variants that were still enriched in the sequenced cohort. Findings were confirmed with additional, geographically matched breast cancer cohorts.

RESULTS

A recurrent heterozygous splice acceptor variant, c.918-1G>C, in SERPINA3, was identified, and it was significantly enriched both in the hereditary (6/201, 3.0%, p = 0.006, OR 5.1, 95% CI 1.7-14.8) and unselected breast cancer cohort (26/1569, 1.7%, p = 0.009, OR 2.8, 95% CI 1.3-6.2). SERPINA3 c.918-1G>C carriers were also significantly more likely to have a rare tumor subtype, medullary breast cancer, than the non-carriers (4/26, 15.4%, p = 0.000014, OR 42.9, 95% CI 11.7-157.1).

CONCLUSION

These findings demonstrate that c.918-1G>C germline variant in SERPINA3 gene, encoding a member of the serine protease inhibitor class, is a novel breast cancer predisposing allele.

Proteomic Analysis of Cerebrospinal Fluid From Patients With Extranodal NK-/T-Cell Lymphoma of Nasal-Type With Ethmoidal Sinus Metastasis

Objective: Extranodal natural killer /T-cell lymphoma (ENKTL) is an aggressive and unusual subtype of non-Hodgkin lymphoma (NHL) that it is related with the Epstein-Barr virus (EBV). CSF is considered as an ideal source of high-concenrtation disease-related proteins. We aimed at identifying the proteomic markers changes of CSF in ENKTL patients and used such changes to diagnose ENKTL.

Materials and methods: In this study, CSF samples were acquired from hospitalization patients from the Cancer Center of West China Hospital, Chengdu, China. Comparative proteomic profiling are commonly used to do label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS). And in this study the same method was used to characterize the variety of proteins in ENKTL patients and none-ENKTL people.

Results: In the aggregate, 421 non-excrescent and functional proteins were identified among the samples. Of these proteins, 45 proteins quantified match the involved criteria. HRG, TIMP-1, SERPINA3, FGA, FGG, TF, FGB, APP, and AGT were significantly up-regulated.

Discussion: We discovered that some proteins were significantly up-regulated. Also, these proteins themselves or with others proteins may be potential markers to diagnose ENKTL. The changes of proteomics may be a potential method to precisely identify the pathogenesis of the ENKTL.

Evaluation of Alpha 1-Antitrypsin for the Early Diagnosis of Colorectal Cancer

Previous proteomic studies have identified alpha 1-antitrypsin (A1AT) as a potential serum biomarker for colorectal cancer (CRC). In this case-control study, we evaluated plasma A1AT concentration and activity as a biomarker for the early diagnosis of colorectal cancer in a group of 113 sporadic CRC patients. We also analyzed A1AT gene promoter methylation, and genotypes in this group of CRC patients. The plasma A1AT and CEA concentrations were measured using the nephelometric and ELISA methods, respectively. A1AT activity was determined by Trypsin Inhibitor Capacity assay. The genomic DNA from blood samples were subjected to Z and S genotype analysis using PCR-RFLP method and the gene promoter methylation in tumors and their adjacent normal tissues was determined by methylation specific-PCR assay. The plasma levels of A1AT and CEA in patients (median, 2.3 g/L and 5.96 ng/ml, respectively) were significantly higher than those in healthy controls (medians, 1.43 g/L and 2.57 ng/ml, respectively) (p = 0.0001). The plasma A1AT activity and concentrations were positively correlated with the tumor stage and well-discriminated between early and advanced stages. The A1AT activity in plasma was the most useful marker for CRC diagnosis (median 4.8 mmol/min/ml in cases vs 1.91 mmol/min/ml in controls, p = 0.0001). No deficient Z or S alleles of A1AT was observed in patients' genotype and the gene promoter tends to be more methylated in normal mucosa than in tumor tissues. We conclude that plasma A1AT activity has better sensitivity and specificity than CEA measurement for the early detection of CRC. Promoter demethylation might play a role in increasing plasma A1AT levels in CRC patients.

Improved survival prognostication of node-positive malignant melanoma patients utilizing shotgun proteomics guided by histopathological characterization and genomic data

Metastatic melanoma is one of the most common deadly cancers, and robust biomarkers are still needed, e.g. to predict survival and treatment efficiency. Here, protein expression analysis of one hundred eleven melanoma lymph node metastases using high resolution mass spectrometry is coupled with in-depth histopathology analysis, clinical data and genomics profiles. This broad view of protein expression allowed to identify novel candidate protein markers that improved prediction of survival in melanoma patients. Some of the prognostic proteins have not been reported in the context of melanoma before, and few of them exhibit unexpected relationship to survival, which likely reflects the limitations of current knowledge on melanoma and shows the potential of proteomics in clinical cancer research.

SERPINA3 Silencing Inhibits the Migration, Invasion, and Liver Metastasis of Colon Cancer Cells

OBJECTIVE

To investigate the impact of SERPINA3 on the migration, invasion, and liver metastasis of colon cancer cells.

METHODS

Immunohistochemical staining was conducted to determine SERPINA3 expression in the cancer and adjacent normal tissues of 131 patients suffering from colon cancer. In vitro experiment, colon cancer cells with low (HT-29P), intermediate (KM-12C), and high (HT-29LMM, KM-12L4) metastatic potential were obtained to examine SERPINA3 expression levels. Besides, quantitative real-time PCR (qRT-PCR) and Western Blot were performed to detect SERPINA3 expression in HT-29LMM and KM-12L4 cells transfected with SERPINA3 siRNA; Wound-healing and Transwell assays to measure cell migration and invasion, respectively; and ELISA to detect MMP-2 and MMP-9 levels. In vivo experiment, mice with liver metastasis of colon cancer were established to observe the effect of SERPINA3 silencing on liver metastasis. Immunohistochemical assay was applied to evaluate the expressions of Serpina3, Mmp-2, Mmp-9, and proliferating cell nuclear antigen (Pcna) in liver metastasis tissues.

RESULTS

SERPINA3 in colon cancer tissues was higher than in adjacent normal tissues, which was associated with patients' clinicopathological features. Besides, SERPINA3 expression showed a rising trend in low, intermediate, and high metastatic potential colon cancer cells. After KM-12L4 and HT-29LMM cells transfected with SERPINA3 siRNA, the migration and invasive ability of cells, as well as the expression levels of MMP-2 and MMP-9 were all decreased. Moreover, SERPINA3 siRNA could not only reduce live metastasis of mice, but also down-regulate the expression of Mmp-2 and Mmp-9 in liver metastasis tissues.

CONCLUSION

SERPINA3 silencing could inhibit the migration, invasion, and liver metastasis of colon cancer cells.

Digital Polymerase Chain Reaction Quantification of SERPINA1 Predicts Prognosis in High-Grade Glioma

BACKGROUND

SERPINA1 plays an anti-inflammatory role in protecting tissues from proteolytic mechanisms. SERPINA1 is positive in gliomas by immunohistochemical analysis; however, the role of SERPINA1, including the relationship with prognosis, has been uncertain. In recent years, digital polymerase chain reaction (PCR) has provided ultra-sensitive assessment of messenger RNA expression from formalin-fixed paraffin-embedded (FFPE) tissues.

OBJECTIVE

In this study, we quantitatively determined the expression of SERPINA1 in high-grade gliomas (HGGs) using digital PCR, and we analyzed its relationship with prognosis.

METHODS

Twenty-nine FFPE surgical samples from patients with HGGs (7 of World Health Organization [WHO] grade III and 22 of WHO grade IV), and human glioblastoma cell lines, U87 and U118, were used for analysis. A qualitative assessment using immunostaining and quantitative assessment using digital PCR were performed to assess the expression of SERPINA1.

RESULTS

The expression of SERPINA1 was demonstrated in glioma tissues and glioblastoma multiforme cell lines by immunostaining. Digital PCR analysis showed that SERPINA1 was expressed in 14.3% and 63.6% of the tissues from patients with grade III and grade IV HGG, respectively (P = 0.035). The median overall survival of 38.8 months in the low SERPINA1 expression group was longer than that of 15.3 months in the high expression group (P = 0.030).

CONCLUSIONS

The frequency and the amount of SERPINA1 expression were higher in grade IV than in grade III HGGs. The high expression of SERPINA1 indicates a poor prognosis of HGGs.

Treponema denticola chymotrypsin-like proteinase may contribute to orodigestive carcinogenesis through immunomodulation

Background:

Periodontal pathogens have been linked to oral and gastrointestinal (orodigestive) carcinogenesis. However, the exact mechanisms remain unknown. Treponema denticola (Td) is associated with severe periodontitis, a chronic inflammatory disease leading to tooth loss. The anaerobic spirochete Td is an invasive bacteria due to its major virulence factor chymotrypsin-like proteinase. Here we aimed to investigate the presence of Td chymotrypsin-like proteinase (Td-CTLP) in major orodigestive tumours and to elucidate potential mechanisms for Td to contribute to carcinogenesis.

Methods:

The presence of Td-CTLP within orodigestive tumour tissues was examined using immunohistochemistry. Oral, tonsillar, and oesophageal squamous cell carcinomas, alongside gastric, pancreatic, and colon adenocarcinomas were stained with a Td-CTLP-specific antibody. Gingival tissue from periodontitis patients served as positive controls. SDS–PAGE and immunoblot were used to analyse the immumodulatory activity of Td-CTLP in vitro.

Results:

Td-CTLP was present in majority of orodigestive tumour samples. Td-CTLP was found to convert pro MMP-8 and -9 into their active forms. In addition, Td-CTLP was able to degrade the proteinase inhibitors TIMP-1, TIMP-2, and α-1-antichymotrypsin, as well as complement C1q.

Conclusions:

Because of its presence within tumours and regulatory activity on proteins critical for the regulation of tumour microenvironment and inflammation, the Td-CTLP may contribute to orodigestive carcinogenesis.

SERPINA3 induced by astroglia/microglia co-culture facilitates glioblastoma stem-like cell invasion

Glioblastoma (GBM) is a highly invasive and malignant brain tumor. Currently, it remains unclear whether Glioblastoma stem-like cells (GSCs) contribute to the invasive phenotype of GBM. Invasion is a complex process involving interactions between tumor cells with the extracellular matrix (ECM), in addition to normal cells. The present study aimed to identify the regulators of GSCs invasion in the GBM tumor microenvironment. An integrative analysis was conducted to identify genes that are important for GSC invasion and are specifically upregulated in astroglia/microglia co-cultured GSCs. Of the identified genes, serpin peptidase inhibitor clade A member 3 (SERPINA3) was observed to be abnormally overexpressed in astroglia/microglia co-cultured GSCs. To further investigate the role of SERPINA3 in glioma pathogenesis and prognosis, a tissue microarray analysis was conducted to evaluate the expression of SERPINA3 and its association to clinicopathological factors and patient survival. The data indicated that upregulation of SERPINA3 was significantly associated with glioma progression and poor patient survival. Furthermore, it was demonstrated that the upregulation of SERPINA3 in glioma may contribute to the invasive behavior of GBM cells by remodeling of the ECM. Overall, the findings of the present study may be useful in future prognosis of GBM patients, suggesting that SERPINA is a potential therapeutic target, and may lead to further understanding of GBM and cancer progression as a whole.

Serpin peptidase inhibitor, clade A member 3 (SERPINA3), is overexpressed in glioma and associated with poor prognosis in glioma patients

Glioma is the most common and aggressive human primary tumor in the central nervous system. Despite present clinical advancements, median survival time remains poor in this malignant tumor. Serpin peptidase inhibitor, clade A member 3 (SERPINA3), is a member of the serpin superfamily of protease inhibitors. Its aberrant expression has been observed in various tumors. However, its clinical significance and biological function in glioma remain unclear, especially for the prognosis of glioma patients. In this study, we investigated SERPINA3 expression in glioma tissue samples and its significance in predicting the prognosis of glioma patients. SERPINA3 protein expression was studied by immunohistochemistry, while real-time polymerase chain reaction was used to study SERPINA3 mRNA expression. We found that SERPINA3 was upregulated in glioma tissue at both mRNA and protein levels, compared with noncancerous brain tissues. We also found that high SERPINA3 expression in glioma tissues correlated significantly with advanced World Health Organization grade. Univariate and multivariate analyses revealed that high SERPINA3 expression was an independent prognostic factor for poor overall survival of glioma patients. Moreover, our findings were further validated by online Oncomine database. Taken together, our results suggest that SERPINA3 plays an oncogenic role in glioma progression and provide an insight into the application of SERPINA3 as a novel predictor of clinical outcomes and a potential biomarker of glioma.

Up-regulation of SERPINA3 correlates with high mortality of melanoma patients and increased migration and invasion of cancer cells

Serpin Peptidase Inhibitor, clade A member 3 (SERPINA3) was found to be abnormally overexpressed in a subset of melanoma tissue biopsies. High SERPINA3 expression was also associated with poor patient survival. In this study, we set out to test SERPINA3 protein's prognostic potential with a larger-sized and independent patient cohort, and to explore SERPINA3's function in melanoma cells. Tissue microarray-based immunohistochemistry analysis showed a significant increase in SERPINA3 expression in invasive and metastatic melanomas compared to normal nevi and melanoma-in-situ (P < 0.001, Chi-square test). In melanoma patients, high SERPINA3 expression was strongly associated with worse overall and disease specific survival at 5 years. Multivariate Cox regression analysis showed that SERPINA3 expression is an independent prognostic factor to predict melanoma patient clinical outcome. When SERPINA3 expression was selectively silenced using small interfering RNA molecules (siRNA) in cultured melanoma cell lines, cell migration and matrix invasion was significantly decreased, but no change in cell proliferation was observed.This study confirms the prognostic potential of SERPINA3 expression in human cutaneous melanoma and reveals the pro-migration and pro-invasion functions of this protein on melanoma cells.

Quantitative proteomic analysis exploring progression of colorectal cancer: Modulation of the serpin family

Colorectal cancer (CRC) remains a major cause of cancer related-death in developed countries. The mortality risk is correlated with the stage of CRC determined at the primary diagnosis and early diagnosis is associated with enhanced survival rate. Currently, only faecal occult blood tests are used to screen for CRC. Consequently, there is an incentive to identify specific markers of CRC. We used quantitative proteomic analysis of serum samples to characterize protein profiles in adenoma, CRC and healthy control samples. We identified 89 distinct proteins modulated between normal, colorectal adenoma and carcinoma patients. This list emphasizes proteins involved in enzyme regulator activities and in particular the serpin family. In serum samples, protein profiles of three members of the serpin family (SERPINA1, SERPINA3 and SERPINC1) were confirmed by ELISA assays. We obtained sensitivity/specificity values of 95%/95% for both SERPINA1 and SERPINC1, and 95%/55% for SERPINA3. This study supports the idea that serum proteins can discriminate adenoma and CRC patients from unaffected patients and reveals a panel of regulated proteins that might be useful for selecting patients for colonoscopy. By evaluating SERPINA1, SERPINA3 and SERPINC1, we highlight the potential role of the serpin family during the development and progression of CRC.

SIGNIFICANCE

Colorectal cancer (CRC) remains a major cause of cancer mortality throughout the world. However, very few CRC biomarkers have satisfactory sensitivity and specificity in clinical practice. To the best of our knowledge our study is the first to profile sera proteomes between adenoma, CRC and healthy patients. We report a comprehensive list of proteins that may be used as early diagnostic biomarkers of CRC. It is noteworthy that 17% of these modulated proteins have been previously described as candidate biomarkers in CRC. Enzyme regulator activity was found to be the main molecular function among these proteins and, in particular, there was an enrichment of members of the serpin family. The subsequent verification on a new cohort by ELISA demonstrates that these serpins could be useful to discriminate healthy from colorectal carcinoma patients with a high sensitivity and specificity. The combination of these biomarkers should increase predictive powers of CRC diagnosis. The remaining candidates form a reserve for further evaluation of additional biomarkers for CRC diagnosis.

Snail and serpinA1 promote tumor progression and predict prognosis in colorectal cancer

The role of Snail and serpin peptidase inhibitor clade A member 1 (serpinA1) in tumorigenesis has been previously identified. However, the exact role and mechanism of these proteins in progression of colorectal cancer (CRC) are controversial. In this study, we investigated the role of Snail and serpinA1 in colorectal cancer (CRC) and examined the mechanisms through which these proteins mediate CRC progression. Immunohistochemical analysis of 528 samples from patients with CRC showed that elevated expression of Snail or serpinA1 was correlated with advanced stage, lymph node metastasis, and poor prognosis. Moreover, we detected a correlation between Snail and serpinA1 expression. Functional studies performed using the CRC cell lines DLD-1 and SW-480 showed that overexpression of Snail or serpinA1 significantly increased CRC cell invasion and migration. Conversely, knockdown of Snail or serpinA1 expression suppressed CRC cell invasion and migration. ChIP analysis revealed that Snail regulated serpinA1 by binding to its promoter. In addition, fibronectin mediated Snail and serpinA1 signaling was involved in CRC cell invasion and migration. Taken together, our data showed that Snail and serpinA1 promoted CRC progression through fibronectin. These findings suggested that Snail and serpinA1 were novel prognostic biomarkers and candidate therapeutic targets in CRC.

Multiplex bioimaging of piRNA molecular pathway-regulated theragnostic effects in a single breast cancer cell using a piRNA molecular beacon

Recently, PIWI-interacting small non-coding RNAs (piRNAs) have emerged as novel cancer biomarkers candidate because of their high expression level in various cancer types and role in the control of tumor suppressor genes. In this study, a novel breast cancer theragnostics probe based on a single system targeting the piRNA-36026 (piR-36026) molecular pathway was developed using a piR-36026 molecular beacon (MB). The piR-36026 MB successfully visualized endogenous piR-36026 biogenesis, which is highly expressed in MCF7 cells (a human breast cancer cell line), and simultaneously inhibited piR-36026-mediated cancer progression in vitro and in vivo. We discovered two tumor suppressor proteins, SERPINA1 and LRAT, that were directly regulated as endogenous piR-36026 target genes in MCF7 cells. Furthermore, multiplex bioimaging of a single MCF7 cell following treatment with piR-36026 MB clearly visualized the direct molecular interaction of piRNA-36026 with SERPINA1 or LRAT and subsequent molecular therapeutic responses including caspase-3 and PI in the nucleus.

Serpin peptidase inhibitor clade A member 1 is a biomarker of poor prognosis in gastric cancer

Background:

In a previous study, we reported that serpin peptidase inhibitor clade A member 1 (serpinA1) is upregulated in Snail-overexpressing gastric cancer. Although serpinA1 has been studied in several types of cancer, little is known about its roles and mechanisms of action. In this study, we examined the role of serpinA1 in the migration and invasion of gastric cancers and determined its underlying mechanism.

Methods:

Expression levels were assessed by western blot analyses and real-time PCR. Snail binding to serpinA1 promoter was analysed by chromatin immunoprecipitation (ChIP) assays. The roles of serpinA1 were studied using cell invasion and migration assays. In addition, the clinicopathologic and prognostic significance of serpinA1 expression were validated in 400 gastric cancer patients using immunohistochemical analysis.

Results:

Overexpression of Snail resulted in upregulation of serpinA1 in gastric cancer cell lines, AGS and MKN45, whereas knockdown of Snail inhibited serpinA1 expression. Chromatin immunoprecipitation analysis showed that overexpression of Snail increased Snail recruitment to the serpinA1 promoter. Overexpression of serpinA1 increased the migration and invasion of gastric cancer cells, whereas knockdown of serpinA1 decreased invasion and migration. Moreover, serpinA1 increased mRNA levels and release of metalloproteinase-8 in gastric cancer cells. Serpin peptidase inhibitor clade A member 1 was observed in the cytoplasm of tumour cells and the stroma by immunohistochemistry. Enhanced serpinA1 expression was significantly associated with increased tumour size, advanced T stage, perineural invasion, lymphovascular invasion, lymph node metastases, and shorter overall survival.

Conclusions:

Serpin peptidase inhibitor clade A member 1 induces the invasion and migration of gastric cancer cells and its expression is associated with the progression of gastric cancer. These results may provide a potential target to prevent invasion and metastasis in gastric cancer.

Serum concentration of alpha-1 antitrypsin is significantly higher in colorectal cancer patients than in healthy controls

Background

The association between alpha-1 antitrypsin (AAT) deficiency and colorectal cancer (CRC) is currently controversial. The present study compares AAT serum concentrations and gene frequencies between a group of CRC patients and a control group of healthy unrelated people (HUP).

Methods

267 CRC subjects (63% males, 72 ± 10 years old) were enlisted from a Hospital Clinic setting in Asturias, Spain. The HUP group comprised 327 subjects (67% males, mean age 70 ± 7.5 years old) from the same geographical region. Outcome measures were AAT serum concentrations measured by nephelometry, and AAT phenotyping characterization by isoelectric focusing.

Results

Significantly higher serum concentrations were found among CRC (208 ± 60) than in HUP individuals (144 ± 20.5) (p = 0.0001). No differences were found in the phenotypic distribution of the Pi*S and Pi*Z allelic frequencies (p = 0.639), although the frequency of Pi*Z was higher in CRC (21%) than in HUP subjects (15%).

Conclusions

The only statistically significant finding in this study was the markedly higher AAT serum concentrations found in CRC subjects compared with HUP controls, irrespective of whether their Pi* phenotype was normal (Pi*MM) or deficient (Pi*MS, Pi*MZ and Pi*SZ). Although there was a trend towards the more deficient Pi* phenotype the more advanced the tumor, the results were inconclusive due to the small sample size. Consequently, more powerful studies are needed to reach firmer conclusions on this matter.

Loss of Grainy head-like 1 is associated with disruption of the epidermal barrier and squamous cell carcinoma of the skin

The Grainyhead-like 1 (GRHL1) transcription factor regulates the expression of desmosomal cadherin desmoglein 1 (Dsg1) in suprabasal layers of the epidermis. As a consequence, the epidermis of Grhl1-null mice displays fewer desmosomes that are abnormal in structure. These mice also exhibit mild chronic skin barrier defects as evidenced by altered keratinocyte terminal differentiation, increased expression of inflammatory markers and infiltration of the skin by immune cells. Exposure of Grhl1^−/− mice to a standard chemical skin carcinogenesis protocol results in development of fewer papillomas than in wild type control animals, but with a rate of conversion to squamous cell carcinoma (SCC) that is strikingly higher than in normal littermates. The underlying molecular mechanism differs from mice with conditional ablation of a closely related Grhl family member, Grhl3, in the skin, which develop SCC due to the loss of expression of phosphatase and tensin homolog (PTEN) and activation of the phosphatidylinositol 3-kinase (PI3K)/AKT/mechanistic target of rapamycin (mTOR) signaling pathway.

Screening preeclamptic cord plasma for proteins associated with decreased breast cancer susceptibility

Preeclampsia, a complication of pregnancy characterized by hypertension and proteinuria, has been found to reduce the subsequent risk for breast cancer in female offspring. As this protective effect could be due to exposure to preeclampsia-specific proteins during intrauterine life, the proteomic profiles of umbilical cord blood plasma between preeclamptic and normotensive pregnancies were compared. Umbilical cord plasma samples, depleted of 14 abundant proteins, were subjected to proteomic analysis using the quantitative method of nanoACQUITY ultra performance liquid chromatography-mass spectrometry with elevated energy mode of acquisition(E) (NanoUPLC-MS(E)). Sixty-nine differentially expressed proteins were identified, of which 15 and 6 proteins were only detected in preeclamptic and normotensive pregnancies, respectively. Additionally, expression of 8 proteins (gelsolin, complement C5, keratin type I cytoskeletal 10, pigment epithelium-derived factor, complement factor B, complement component C7, hemoglobin subunit gamma-2 and alpha-fetoprotein) were up-regulated in preeclampsia with a fold change of ≥2.0 when compared to normotensive pregnancies. The identification of alpha-fetoprotein in preeclamptic umbilical cord blood plasma supported the validity of this screen as alpha-fetoprotein has anti-estrogenic properties and has previously been linked to preeclampsia as well as a reduced breast cancer risk. The findings of this pilot study may provide new insights into the mechanistic link between preeclampsia and potentially reduced breast cancer susceptibility in adult life.

Alpha-1 Antitrypsin Blood Levels as Indicator for the Efficacy of Cancer Treatment

Background

Alpha-1 antitrypsin (α₁-AT) is a member of the serine protease inhibitors (serpins) family. Liver cells are the major source of synthesis and secretion of (α₁-AT) into the blood. Moreover, it has been demonstrated that α₁-AT is expressed and secreted by many types of malignant cells. Studies have indicated that serum levels of (α₁-AT) increase in a good number of malignant diseases. In addition, a significant correlation between serum levels and cancer stage has also been reported. In this work we aimed to test how α₁-AT levels behave at the third week after treatment with chemotherapy.

Methods

The α₁-AT blood levels were measured using commercially available radial immunodiffusion kit (Kent Laboratory Inc, Bellinham, Washigton) following manufacturer instructions.

Results

The α₁-AT blood levels were significantly decreased after treatment compared with those before the treatment started. The mean difference (before - after) treatment was 127.82 and 137.37 mg/dL with 95% CI of difference 109.06 - 146.57 and 116.08 - 158.65 mg/dL in lung and prostate cancer respectively. When we compared these levels according to the stage of cancer, we found that the mean difference (before - after) treatment was also highly significant as indicated by P-value and the 95% CI of these differences.

Conclusion

Obtained data strongly indicate the value of testing α₁-AT blood levels as one of the important indicators for the efficacy of cancer treatment.

Evaluation of humoral immunity in oral cancer patients from a nigerian referral centre

The immune system is central in the body's defense against non-self. Immunoglobulins and acute phase proteins have been reported to play active roles in carcinogenesis. This prospective longitudinal study was carried out to determine the state of humoral immunity in Nigerian oral cancer patients relative to controls. Twenty newly diagnosed untreated cases of oral squamous cell carcinoma recruited from our centre were included in the study. The controls included 20 apparently healthy and HIV negative volunteers. Serum immunoglobulin classes and acute phase proteins were measured using immunoplates. IgA and ceruloplasmin showed statistically significantly elevated levels in the patients compared with controls, while increases in IgM and IgG were insignificant. The raised levels suggest a role for immunoglobulin A and ceruloplasmin in the mechanisms involved in oral cancers. Findings from this study are similar to that reported elsewhere in the literature. Further work is needed to ascertain the role and usefulness of immunoglobulins and acute phase proteins in staging, disease monitoring, therapy and prognostication.

S-glutathionylated serine proteinase inhibitors as plasma biomarkers in assessing response to redox-modulating drugs

Many cancer drugs impact cancer cell redox regulatory mechanisms and disrupt redox homeostasis. Pharmacodynamic biomarkers that measure therapeutic efficacy or toxicity could improve patient management. Using immunoblot analyses and mass spectrometry, we identified that serpins A1 and A3 were S-glutathionylated in a dose- and time-dependent manner following treatment of mice with drugs that alter reactive oxygen or nitrogen species. Tandem mass spectrometry analyses identified Cys(256) of serpin A1 and Cys(263) of serpin A3 as the S-glutathionylated residues. In human plasma from cancer patients, there were higher levels of unmodified serpin A1 and A3, but following treatments with redox active drugs, relative S-glutathionylation of these serpins was higher in plasma from normal individuals. There is potential for S-glutathionylated serpins A1 and A3 to act as pharmacodynamic biomarkers for evaluation of patient response to drugs that target redox pathways.

Proteomic analysis of urinary biomarker candidates for nonmuscle invasive bladder cancer

Nonmuscle invasive tumors of the bladder often recur and thereby bladder cancer patients need regular re-examinations which are invasive, unpleasant, and expensive. A noninvasive and less expensive method, e.g. a urine dipstick test, for monitoring recurrence would thus be advantageous. In this study, the complementary techniques mass spectrometry (MS) and Western blotting (WB)/dot blot (DB) were used to screen the urine samples from bladder cancer patients. High resolving MS was used to analyze and quantify the urinary proteome and 29 proteins had a significantly higher abundance (p<0.05) in bladder cancer samples compared with control urine samples. The increased abundance found in urine from bladder cancer patients compared with controls was confirmed with Western blot for four selected proteins; fibrinogen β chain precursor, apolipoprotein E, α-1-antitrypsin, and leucine-rich α-2-glycoprotein 1. Dot blot analysis of an independent urine sample set pointed out fibrinogen β chain and α-1-antitrypsin as most interesting biomarkers having sensitivity and specificity values in the range of 66-85%. Exploring the Human Protein Atlas (HPA) also revealed that bladder cancer tumors are the likely source of these proteins. They have the potential of being useful in diagnosis, monitoring of recurrence and thus may improve the treatment of bladder tumors, especially nonmuscle invasive tumors.

Serpin peptidase inhibitor clade A member 1 (SerpinA1) is a novel biomarker for progression of cutaneous squamous cell carcinoma

The incidence of keratinocyte-derived nonmelanoma skin cancers is increasing worldwide because of cumulative recreational exposure to sunlight. At present, no specific molecular markers are available for assessing the progression of premalignant actinic keratoses to invasive cutaneous squamous cell carcinoma (SCC). We examined the role of the Serpin family in skin SCCs. Expression profiling of cutaneous SCC cell lines (n = 8) revealed up-regulation of SerpinA1 compared with normal epidermal keratinocytes (n = 5). Analysis with quantitative RT-PCR showed that the mean level of SerpinA1 mRNA was markedly up-regulated in cutaneous SCC cell lines (n = 8) compared with in normal keratinocytes. SerpinA1 production by SCC cells was dependent on p38 mitogen-activated protein kinase activity and was up-regulated by epidermal growth factor, tumor necrosis factor-α, interferon-γ, and IL-1β. Immunostaining of tissue arrays with 148 human tissue samples revealed tumor cell-associated expression of SerpinA1 in 19 of 36 actinic keratoses, 22 of 29 Bowen's disease samples, 67 of 71 sporadic SCCs, and all 12 recessive dystrophic epidermolysis bullosa-associated SCCs examined. Moreover, tumor cell-associated SerpinA1 staining was detected in all chemically induced mouse skin SCCs studied (n = 17). Overexpression of SerpinA1 mRNA was also detected by quantitative RT-PCR in chemically induced mouse skin SCCs (n = 14) compared with control tissues (n = 14). These data identify SerpinA1 as a novel tumor cell-associated biomarker for progression of cutaneous SCCs.

Protease inhibitor SERPINA1 expression in epithelial ovarian cancer

Epithelial ovarian cancer is the most lethal gynecologic cancer with a 5 years survival rate of 30-40% in patients diagnosed with high-grade invasive disease (TOV). This is in stark contrast to the 95% 5 years survival rate in ovarian cancer patients diagnosed with low malignant potential (LMP) disease. The progression from localized tumor to invasive metastasis involves matrix proteolysis. Protease inhibitors are thought to play a key role by limiting this process. Using the Affymetrix HG-U133A GeneChip array, we have studied all serine protease inhibitors and found several serpin family members that are differentially expressed between LMP and TOV serous tumors. SERPINA1 was selected for further study due to its high expression in the majority of LMP tumors and its low expression in TOV tumors; observations that were also validated by quantitative-PCR (Q-PCR). To study the effects of its over expression on different tumorigenic parameters, SERPINA1 was cloned in the pcDNA3.1+ plasmid which was subsequently used to derive stable clones from two invasive ovarian cancer cell lines, TOV-112D and TOV-1946. We found no effect of SERPINA1 over expression on tumor growth in SCID mice although cell migration and invasion were affected in in vitro assays. There was also no association between patient survival and SERPINA1 immunostaining, however, SERPINA1 localization was different in LMP (nuclear) and TOV (cytoplasmic) tumors. SERPINA1 remains an interesting candidate since protein homeostasis, regulated by proteases and their inhibitors, should be studied holistically in order to assess their full impact in tumor progression.

Serpin peptidase inhibitor clade A member 1 as a potential marker for malignancy in insulinomas

PURPOSE

The biological behavior of insulinomas cannot be predicted based on histopathologic criteria in which the diagnosis of malignancy is confirmed by the presence of metastases. In this study, microarray and quantitative real-time reverse transcription-PCR were applied to identify differentially expressed genes between malignant and nonmalignant insulinomas to search for useful biomarkers to recognize the metastatic potential of insulinomas.

EXPERIMENTAL DESIGN

Code Link human bioarrays were used to analyze differences in approximately 20,000 genes between six well-differentiated endocrine tumors of benign behavior compared with one well-differentiated endocrine carcinoma (WDEC) and three metastases of endocrine carcinomas (MEC). Quantitative real-time reverse transcription-PCR was used to validate differential expressions of five genes in a series of 35 sporadic insulinomas. Serpin peptidase inhibitor clade A member 1 (SERPINA1; alpha-1-antitrypsin) expression, identified as up-regulated in malignant insulinomas, was also evaluated by immunohistochemistry.

RESULTS

Analysis of microarray data resulted in 230 differentially expressed genes. Gene Ontology analysis identified serine-type endopeptidase activity and serine-type endopeptidase inhibitor activity as pathways presenting significant differential expression. Protease serine 2 and complement factor B (from serine-type endopeptidase activity pathway) were respectively confirmed as up-regulated in well-differentiated endocrine tumors of benign behavior (WDET) and in WDEC/MEC. Angiotensinogen and SERPINA1 (from serine-type endopeptidase inhibitor activity pathway) were confirmed as up-regulated in WDEC/MEC. SERPINA1 was shown to be expressed in 85.7% of malignant versus 14.3% of nonmalignant insulinomas by immunohistochemistry.

CONCLUSIONS

Our data are consistent to the possibility that SERPINA1 is a marker of malignancy in insulinomas. Given the widespread availability of antibody anti-alpha-1-antitrypsin in pathology services, SERPINA1 expression evaluation might be of clinical utility in recognizing patients more likely to develop an aggressive presentation.

Proteomic analysis reveals field-wide changes in protein expression in the morphologically normal mucosa of patients with colorectal neoplasia

Models for the pathogenesis of colorectal cancer tend to focus on the localized lesion, with less attention paid to changes in normal-appearing mucosa. Here we used two-dimensional gel electrophoresis and mass spectrometry to define patterns of protein expression in morphologically normal colonic mucosa from 13 healthy subjects, 9 patients with adenomatous polyps, and 9 with cancer. Tumor samples were also compared with the normal mucosa. Systematic gel comparisons identified a total of 839 spots that differed significantly between one or more groups (P < 0.05). Principle component analysis indicated that the first three components accounted for approximately 37% of the total variation and provided clear evidence that flat mucosa from healthy subjects differed significantly from that of patients with polyps or cancer. Sixty-one proteins differed significantly between mucosa from healthy subjects and all other tissue types, and 206 differed significantly between healthy mucosa and polyp mucosa. Several of the proteins showing significant underexpression in tumor tissue were cytokeratins and other cytoskeletal components. In contrast, cytokeratins, including several isoforms of cytokeratin 8, were overexpressed in apparently normal mucosa from polyp and cancer patients compared with mucosa from healthy subjects. These findings indicate that protein expression in the apparently normal colonic mucosal field is modified in individuals with neoplastic lesions at sites distant from the lesion. Recognition and further characterization of this field effect at the molecular level may provide protein biomarkers of susceptibility to colorectal cancer and facilitate development of hypotheses for the role of diet and other environmental factors in its causation.

Serpin A1 is overexpressed in ALK+ anaplastic large cell lymphoma and its expression correlates with extranodal dissemination

Anaplastic large cell lymphoma (ALCL) is a distinct subtype of non-Hodgkin's lymphoma. Most of ALCLs (85%) carry a chromosomal translocation involving different partners in the 5' portion, and the anaplastic lymphoma kinase (ALK) receptor kinase domain in the 3' portion. These translocations induce the ectopic expression of X-ALK proteins, thought to be involved in lymphomagenesis, through the dysregulation of cell proliferation and apoptotic pathways. In the present study, based on several ALK+ and ALK- ALCL cell lines and biopsy specimens, we showed that serpin A1, a secretory glycoprotein, was overexpressed in ALK+ ALCL cell lines and ALK+ tumors at both the transcriptional and translational levels. The crucial role of NPM-ALK in the regulation of serpin A1 expression was further demonstrated by using both ectopic expression and downregulation, by RNA interference, of the NPM-ALK oncogene. In addition, in ALK+ tumors, serpin A1 expression appeared to be correlated with the clinical status of the patients as the serpin A1 mRNA level was higher in patients presenting with extranodal dissemination. These data, together with the pattern of expression of serpin A1 we observed in ALK+ tumors, suggest that serpin A1 has an invasion-promoting effect in ALK+ ALCL.

Differential proteome analysis of conditioned media to detect Smad4 regulated secreted biomarkers in colon cancer

Smad4 is a tumor suppressor gene primarily involved in carcinogenesis of the pancreas and colon. The functional inactivation of Smad4 is a late step genetically. In pancreatic carcinogenesis, loss of Smad4 marks the transition to invasive growth. In colorectal cancers, the frequency of Smad4 inactivation is markedly increased in metastatic cancers. We have established cell biological models, re-expressing Smad4 in deficient human cancer cells, in which we could show that Smad4 is adequate to suppress tumor growth through suppression of angiogenic and invasive properties. Thus, pairs of Smad4-re-expressing and Smad4-deficient cells are prone to model the progression from premalignant stages to carcinomas in the carcinogenic process and may provide access to Smad4 targets of high clinical relevance. We present here a "differential secretome analysis", comparing all the proteins released in vitro from the Smad4-deficient and Smad4-re-expressing SW480 human colon carcinoma cells. The differential secretome catalog comprises more than 25 proteins including proteases and protease inhibitors, as well as established tumor biomarkers. In conclusion, this approach proved to be a sensitive tool to specifically detect Smad4 targets relevant for tumor-stroma interactions. It is also able to reflect complex alterations of cellular physiology. Moreover, the results support our hypothesis that human tumor markers detectable in serum may be identified through differential secretome analyses.

Tumor–host interactions contribute to the elevated expression level of α1-antichymotrypsin in metastatic breast tumor xenografts

We investigated alpha1-antichymotrypsin (ACT) gene expression in xenograft tumors generated by two isogenic human breast cancer cell lines derived from the same parent, MDA-MB-435, which display opposite metastatic behaviors. Microarray and real-time PCR experiments showed an overexpression of this serine protease inhibitor in the metastatic tumors (M-4A4T) and its derived metastases (M4-Mets) compared with the weakly metastatic tumors (NM-2C5T), and its release into the blood was confirmed by western-blotting. However, functional assays in vivo using genetically engineered tumor cells demonstrated that ACT up-regulation was not, by itself, responsible for the metastatic phenotype. We also made observations that ACT gene regulation was sensitive to tumor-host interactions: inoculation of these lines into the mouse mammary gland greatly increased ACT production and accentuated the intrinsic difference observed when they are cultured in vitro. Sensitivity of tumor cells to their environment was further analyzed by in vitro experiments, which demonstrated that a purified ECM environment and soluble components from normal host mammary cells were both able to significantly promote ACT expression. In addition, we took advantage of the xenogeneic nature of the model to measure ACT expression by the host cells (mouse) and the tumor cells (human) within the neoplasm using species-specific primers in real-time PCR experiments. It was found that the presence of tumor cells, irrespective of their metastatic capabilities, induced local ACT production by host cells at the primary and secondary tumor sites. Thus, this work indicates that there is a specific association of ACT overexpression with the metastatic phenotype in our breast cancer metastasis model. Moreover, because of the xenogeneic nature of our system, we were able to provide evidence of tumor-host reciprocal regulation of ACT production.

Secretory leukocyte protease inhibitor promotes the tumorigenic and metastatic potential of cancer cells

Because of their ability to inhibit proteases, protease inhibitors have generally been considered to counteract tumor progression and metastasis. However, expression of serine protease inhibitors (SPIs) in tumors is often associated with poor prognosis of cancer patients. Moreover, there is growing evidence that SPIs may even promote malignancy of cancer cells, opening new avenues for their use as biomarkers in malignancy. To isolate cancer promoting genes, we applied the suppression subtractive hybridization method to low-malignant Lewis Lung Carcinoma 3LL-S versus high-malignant 3LL-S-sc cells. This resulted in the identification of the SPI secretory leukocyte protease inhibitor (SLPI), as one of the genes whose expression was higher in 3LL-S-sc than in 3LL-S cells. By stable transfection of 3LL-S cells with mouse or human SLPI, we demonstrated that elevated levels of SLPI expression increased both the tumorigenicity and lung-colonizing potential of 3LL-S cells. Moreover, we showed that this function of SLPI depended on its protease inhibitory capacity. Our results also reveal that although SLPI enhanced the proliferation of 3LL-S cells in vitro, its promalignant activity in vivo was not solely due to its effect on cell proliferation. In this study, we report a causal role for SLPI in the malignant behavior of cancer cells, underscoring the potential malignancy-promoting activities of SPIs.

Effects of native and cleaved forms of alpha1-antitrypsin on ME 1477 tumor cell functional activity

Tumor cells synthesize and release a variety of substances, including proteases and protease inhibitors involved in cell growth and proliferation. alpha1-Antitrypsin (AAT) is a serine proteinase inhibitor synthesized primarily in the liver, but also in extra-hepatic tissues and cells, including tumor cells. AAT exists not only in a native, active inhibitory form, but also in several, non-inhibitory forms, such as cleaved and/or degraded. This study was designed to investigate the synthesis of AAT by melanoma cells, ME 1477, and the effects of native, cleaved and C-terminal fragment of AAT (C-36) on cell functional activity. We found that ME 1477 cells synthesize and secrete AAT with the same apparent molecular mass as described for AAT purified from plasma, but with no measurable inhibitory activity. As determined by Western blot after immunoprecipitation of [32S]-labeled AAT, exogenous native or modified forms of AAT added to the cells at a concentration of 10 microM did not change AAT synthesis. Moreover, cells exposed to native AAT show decreased [3H]-thymidine incorporation by 53% and tissue inhibitor of metalloproteinases (TIMP)-1 levels by 36%. In contrast, cells treated with C-36 peptide significantly increased metalloproteinase activity, and [3H]-thymidine incorporation by 35%. Specifically, pro-collagenase-1 levels were found to be increased by 1.4-fold and decreased by 1.5-fold in cells treated with C-36 peptide and native AAT, respectively. Cleaved form of AAT had no significant effects on parameters measured. Data obtained from this study suggest that specific forms of AAT have multiple effects on tumor cell viability and play diverse roles in tumorogenesis.

Conformational properties of serine proteinase inhibitors (serpins) confer multiple pathophysiological roles

Serine proteinase inhibitors (Serpins) are irreversible suicide inhibitors of proteases that regulate diverse physiological processes such as coagulation, fibrinolysis, complement activation, angiogenesis, apoptosis, inflammation, neoplasia and viral pathogenesis. The molecular structure and physical properties of serpins permit these proteins to adopt a number of variant conformations under physiological conditions including the native inhibitory form and several inactive, non-inhibitory forms, such as complexes with protease or other ligands, cleaved, polymerised and oxidised. Alterations of a serpin which affect its structure and/or secretion and thus reduce its functional levels may result in pathology. Serpin dysfunction has been implicated in thrombosis, emphysema, liver cirrhosis, immune hypersensitivity and mental disorders. The loss of inhibitory activity of serpins necessarily results in an imbalance between proteases and their inhibitors, but it may also have other physiological effects through the generation of abnormal concentrations of modified, non-inhibitory forms of serpins. Although these forms of inhibitory serpins are detected in tissues and fluids recovered from inflammatory sites, the important questions of which conditions result in generation of different molecular forms of serpins, what biological function these forms have, and which of them are directly linked to pathologies and/or may be useful markers for characterisation of disease states, remain to be answered. Elucidation of the biological activities of non-inhibitory forms of serpins may provide useful insights into the pathogenesis of diseases and suggest new therapeutic strategies.

Enhanced tumor growth and invasiveness in vivo by a carboxyl-terminal fragment of alpha1-proteinase inhibitor generated by matrix metalloproteinases: a possible modulatory role in natural killer cytotoxicity

Matrix metalloproteinases (MMPs) are believed to contribute to the complex process of cancer progression. They also exhibit an alpha1-proteinase inhibitor (alphaPI)-degrading activity generating a carboxyl-terminal fragment of approximately 5 kd (alphaPI-C). This study reports that overexpression of alphaPI-C in S2-020, a cloned subline derived from the human pancreas adenocarcinoma cell line SUIT-2, potentiates the growth capability of the cells in nude mice. After stable transfection of a vector containing a chimeric cDNA encoding a signal peptide sequence of tissue inhibitor of metalloproteinase-1 followed by cDNA for alphaPI-C into S2-020 cells, three clones that stably secrete alphaPI-C were obtained. The ectopic expression of alphaPI-C did not alter in vitro cellular growth. However, subcutaneous injection of the alphaPI-C-secreting clones resulted in tumors that were 1.5 to 3-fold larger than those of control clones with an increased tendency to invasiveness and lymph node metastasis. These effects could be a result of modulation of natural killer (NK) cell-mediated control of tumor growth in nude mice, as the growth advantage of alphaPI-C-secreting clones was not observed in NK-depleted mice, and alphaPI-C-secreting clones showed decreased NK sensitivity in vitro. In addition, production of alphaPI and generation of the cleaved form of alphaPI by MMP were observed in various human tumor cell lines and in a highly metastatic subline of SUIT-2 in vitro. These results provide experimental evidence that the alphaPI-degrading activity of MMPs may play a role in tumor progression not only via the inactivation of alphaPI but also via the generation of alphaPI-C.

Alpha-1-antichymotrypsin expression in lung adenocarcinoma and its possible association with tumor progression

BACKGROUND

Alpha-1-antichymotrypsin (ACT) is a serine protease inhibitor, expression of which has been shown in various tumor types, but its biologic and clinical implications in tumor tissues are obscure. The authors examined ACT expression in lung adenocarcinoma to determine its clinicopathologic and prognostic significance.

METHODS

First, reverse transcriptase-polymerase chain reaction (RT-PCR) using oligonucleotide primers specific for ACT and Western blotting and immunohistochemical methods using anti-ACT antibodies were performed in several lung adenocarcinoma cell lines. Secondly, ACT expression in clinical materials was examined immunohistochemically.

RESULTS

By RT-PCR, Western blotting, and immunohistochemical methods, ACT synthesis was confirmed in several lung adenocarcinoma cell lines. Seventy-five (52%) of 170 surgically resected lung adenocarcinomas showed positive staining for ACT mainly in the cytoplasm, and the incidence of ACT expression was significantly higher in advanced T classification tumors (P = 0.009) or large sized tumors (P = 0.004). Tumors with a higher rate of mitosis were significantly positive for ACT expression (P = 0.023). Patients with ACT-positive adenocarcinoma had a shorter disease free survival (DFS) and a poor prognosis compared with those who were ACT-negative, most significantly among Stage I tumors (DFS, P = 0.003; overall survival, P = 0.006). In a multivariate analysis, the P value of ACT expression status in Stage I tumors was marginally significant (overall survival; P = 0.058).

CONCLUSIONS

These results using cell lines suggest the potential productivity of ACT by lung adenocarcinoma cells. The data in clinical materials, combined with results of the previous report that ACT in breast cancer acts as a minor growth factor-like substance, suggest that ACT expression in lung adenocarcinoma also may be associated closely with tumor progression and especially with tumor growth. Alpha-1-antichymotrypsin expression status in Stage I tumors may be a potential independent prognostic factor.

Reverse-zymographic analysis of protease nexin-II/amyloid beta protein precursor of human carcinoma cell lines, with special reference to the grade of differentiation and metastatic phenotype

Trypsin inhibitors in serum-free conditioned media (SFCM) of various human carcinoma cell lines were analyzed by reverse zymography. Most of the cells secreted high-molecular-weight trypsin inhibitors (HMTI) larger than 100 kDa. The cell lines of colorectal carcinoma origin had a tendency to secrete HMTI whose molecular weight was a little higher than that of the other cell lines. Analysis of SFCM of subclones with different histological differentiation and metastatic/invasive potentials derived from a single pancreatic carcinoma cell line SUIT-2 showed that the HMTI activity in SFCM was correlated to the degree of histological differentiation in vivo and tended to be inversely correlated to their metastatic/invasive capabilities. Immunoblotting analysis revealed that these HMTI were protease nexin-II/amyloid beta protein precursors (PN-II/APP). Semi-quantificative reverse-transcriptase/polymerase-chain reaction study for PN-II/APP mRNAs suggested that the differences in PN-II/APP activities in SFCM between the subclones might be post-transcriptional or post-secretional events. In addition, SFCM of a highly metastatic subclone contained 43-kDa protein which reacted to anti-APP monoclonal antibody (MAb) suggesting that the subclone may have APP-degrading activity.

Immunohistochemical characterization of undifferentiated carcinomas of the ovary

Immunohistochemical characteristics of undifferentiated carcinomas of the ovary were examined using formalin-fixed, paraffin-embedded tissues with an avidin-biotin staining approach. Eight cases were collected from the pathology files of our Institute from a total of 214 recorded malignant ovarian tumors. For immunostaining, antibodies reacting with epithelial membrane antigen (EMA), pankeratin, vimentin, CA 125, CA 19-9, carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), alpha-1-antitrypsin (AT), epidermal growth factor receptor (EGFR), c-erbB-2, bcl-2 and p53 proteins were used. All the cases examined were positive for EMA and pankeratin, specific markers for epithelial tumors, negative for the non-epithelial tumor marker, vimentin, and also positive for EGFR. Interestingly, only one case was positive for CA 125, despite it being one of the commonest reported indicators of ovarian cancer. CA 19-9 was positive in 7 cases, CEA in 5, AFP in 2, AT in 6 and c-erbB-2 protein in 4. Two cases were positive for p53 protein, and in 1 of these positive staining for bcl-2 was also observed. These results indicate that the epithelial nature is well preserved in undifferentiated ovarian carcinomas, although consistently positive reactions were not observed within the cases for some antigens. They further clearly show that a negative signal for CA 125 can not be considered to exclude the possibility of a primary ovarian tumor.

Enteric alpha-1-antitrypsin loss and comparison with Okokit II and Haemoccult for the detection of colorectal cancer

Faecal samples from patients with symptomatic colorectal cancer (n = 19) and from control subjects (n = 54) were analysed for alpha-1-antitrypsin (A1AT) and compared with Haemoccult and Okokit II. A1AT was also measured in paired samples of normal colonic mucosa and cancer tissue (n = 16) and in media from four human colorectal cell lines (COLO 320 DM, SW620, HT29, LS 174T). Faecal A1AT concentrations were greater than controls (P < 0.0001) and detected 12 (63%) patients with cancer compared to 10 (53%) by Okokit II and 7 (37%) by Haemoccult (P > 0.05). A1AT concentrations from colonic mucosa (median, range: 0.46, 0.17-0.79 mg/g wet wt) were greater (P = 0.01) than cancer tissue (0.29, 0.13-0.74 mg/g wt wt). Adjusting for albumin, A1AT concentrations from mucosa (12.0, 3.8-32.2 mg/g albumin) remained greater (P = 0.003) than for cancer tissue (5.9, 2.4-21.4 mg/g albumin). A1AT was not detected in any of the cell-line media. The most likely mechanisms for increased faecal A1AT concentrations, apart from increased blood loss, are increased cell turnover or leakage from epithelial tight junctions. The use of faecal A1AT measurement for the detection of colorectal cancer deserves further assessment.

Modulation of proliferation of cultured human cells by urinary trypsin inhibitor

Several reports have indicated that proteinase inhibitors can act as both stimulators and inhibitors of the growth of cultured cells. To confirm and extend these reports, we have purified the trypsin inhibitor from human urine (UTI). We have demonstrated a biphasic effect of this protein on the proliferation of human fibroblasts, and have identified two types of cellular binding site which may be responsible for the stimulatory and inhibitory aspects of this effect. Both aspects of UTI action have also been observed in human tumour cell cultures, but they are not consistently associated in these cells.

Establishment and characterization of a human lung adenocarcinoma cell line (LC-2/ad) producing alpha 1-antitrypsin in vitro

A new human cell line, LC-2/ad was established from pleural effusion of pulmonary adenocarcinoma of a 51 year old Japanese female. The LC-2/ad cells exhibit an epithelial appearance and a tendency to form small domes as observed with phase-contrast microscopy. The modal chromosome number was 53-56. Plating efficiency and doubling time were 6.8% and 58 h, respectively (32th passage). Immunocytochemically, the cells were strongly positive for CEA and cytokeratins including cytokeratin no. 18 which is present in simple epithelia. Ultrastructurally, the cultured cells were characterized by well-formed junctional complexes and microvilli. Subcutaneous injection of 5 x 10(6) cells into a nude mouse resulted in tumor formation classified histologically as a moderately differentiated adenocarcinoma. This cell line produced at least two functionally active trypsin inhibitors together with several proteinases in vitro. The main inhibitor was purified partially from the serum-free conditioned medium and confirmed immunologically as human alpha 1-antitrypsin (AAT). Immunohistochemically, the xenografted tumor was also positive for AAT. The cell line LC-2/ad is useful for the study of tumor-derived serine proteinase inhibitors, in particular AAT.