Autocrine induction of invasion and metastasis by tumor-associated trypsin inhibitor in human colon cancer cells

A novel 9-gene signature for the prediction of postoperative recurrence in stage II/III colorectal cancer

Background: Individualized recurrence risk prediction in patients with stage II/III colorectal cancer (CRC) is crucial for making postoperative treatment decisions. However, there is still a lack of effective approaches for identifying patients with stage II and III CRC at a high risk of recurrence. In this study, we aimed to establish a credible gene model for improving the risk assessment of patients with stage II/III CRC. Methods: Recurrence-free survival (RFS)-related genes were screened using Univariate Cox regression analysis in GSE17538, GSE39582, and GSE161158 cohorts. Common prognostic genes were identified by Venn diagram and subsequently subjected to least absolute shrinkage and selection operator (LASSO) regression analysis and multivariate Cox regression analysis for signature construction. Kaplan-Meier (K-M), calibration, and receiver operating characteristic (ROC) curves were used to assess the predictive accuracy and superiority of our risk model. Single-sample gene set enrichment analysis (ssGSEA) was employed to investigate the relationship between the infiltrative abundances of immune cells and risk scores. Genes significantly associated with the risk scores were identified to explore the biological implications of the 9-gene signature. Results: Survival analysis identified 347 RFS-related genes. Using these genes, a 9-gene signature was constructed, which was composed of MRPL41, FGD3, RBM38, SPINK1, DKK1, GAL3ST4, INHBB, CTB-113P19.1, and FAM214B. K-M curves verified the survival differences between the low- and high-risk groups classified by the 9-gene signature. The area under the curve (AUC) values of this signature were close to or no less than the previously reported prognostic signatures and clinical factors, suggesting that this model could provide improved RFS prediction. The ssGSEA algorithm estimated that eight immune cells, including regulatory T cells, were aberrantly infiltrated in the high-risk group. Furthermore, the signature was associated with multiple oncogenic pathways, including cell adhesion and angiogenesis. Conclusion: A novel RFS prediction model for patients with stage II/III CRC was constructed using multicohort validation. The proposed signature may help clinicians better manage patients with stage II/III CRC.

Serine protease inhibitor Kazal type 1 (SPINK1) promotes proliferation, migration, invasion and radiation resistance in rectal cancer patients receiving concurrent chemoradiotherapy: a potential target for precision medicine

Serine peptidase inhibitor Kazal type-1 (SPINK1), a trypsin kinase inhibitor, is known to be associated with inflammation and pathogenesis. The aim in this study was to demonstrate the clinicopathological role and progression of SPINK1 in rectal cancer (RC) patients undergoing concurrent chemoradiotherapy (CCRT). Immunohistochemical staining for SPINK1 protein expression in 111 RC cases revealed high SPINK1 expression was significantly associated with perineural invasion and poor CCRT response in pre-CCRT specimens. In addition, multivariable analyses showed that pre-CCRT SPINK1 expression was a significant prognostic marker of both overall and disease-free survival in RC patients receiving pre-operative CCRT; furthermore, in vitro studies demonstrated SPINK1 interacted with EGFR to promote the abilities of proliferation, migration and invasion attenuated by SPINK1 si-RNA via ERK, p38, and JNK pathways. SPINK1 was also found to regulate radio-resistance in CRC cell lines. In conclusion, SPINK1 expression is an independent prognostic marker in patients receiving pre-operative CCRT, and SPINK1 regulates proliferation, migration and invasion via EGFR-downstream ERK, p38 and JNK pathways. The phenotypes of radiosensitivity that could be reversed with attenuation of SPINK1 levels suggest that targeting SPINK1 might offer a strategy for optimal precision medicine.

The multi-molecular mechanisms of tumor-targeted drug resistance in precision medicine

Clinically, cancer drug therapy is still dominated by chemotherapy drugs. Although the emergence of targeted drugs has greatly improved the survival rate of patients with advanced cancer, drug resistance has always been a difficult problem in clinical cancer treatment. At the current level of medicine, most drugs cannot escape the fate of drug resistance. With the emergence and development of gene detection, liquid biopsy ctDNA technology, and single-cell sequencing technology, the molecular mechanism of tumor drug resistance has gradually emerged. Drugs can also be updated in response to drug resistance mechanisms and bring higher survival benefits. The use of new drugs often leads to new mechanisms of resistance. In this review, the multi-molecular mechanisms of drug resistance are introduced, and the overcoming of drug resistance is discussed from the perspective of the tumor microenvironment.

Raised SPINK1 levels play a role in angiogenesis and the transendothelial migration of ALL cells

The present study was designed to assess whether raised Serine protease inhibitor Kazal type 1 (SPINK1) expressions modulates angiogenesis. Human umbilical vein endothelial cells (HUVECs) exposed to SPINK1 were noted to exhibit raised expressions of interleukin-8 (IL-8) as well as VCAM-1 and ICAM-1 cell adhesion molecules in a dose-dependent manner. In co-culture system of HUVECs and Acute lymphoblastic leukemia (ALL) cells, SPINK1 exposure also resulted in enhanced endothelial cell motility and ALL cells trans-endothelial migration. High concentrations of SPINK1 caused in vitro cellular reorganization into tubes in Matrigel-cultured HUVECs and induced in vivo vascularization and brain infiltration of NOD/SCID ALL model mice. The further transcriptomic analysis indicated that SPINK1 treatment altered several biological processes of endothelial cells and led to activation of the MAPK pathway. This study is the first to determine the neovascularization effects of raised SPINK1.

Rare case of metachronous tumor: Nasopharyngeal and colorectal carcinoma

The study presents an unusual case of a patient with a personal history of a rectal malignant tumor in 2013, who after a period of 6 years, was diagnosed with an advanced nasopharyngeal carcinoma, locally and regionally invasive. It is possible that the colorectal malignant tumor affected the development of the nasopharyngeal carcinoma, or the other way around, depending on the presence of genetic instabilities. These two types of malignant tumors share a series of genes that can influence their progression, i.e., SPINK-6 and Bcl-2. The particularity of this case stems from the development of a metachronous tumor, a rectal adenocarcinoma and nasopharyngeal carcinoma, two malignant tumors with different patient prognosis and disease progression. Research needs to be continued on the multidisciplinary therapeutic management of nasopharyngeal cancer and the ways of identifying this cancer type in its early stages, considering that most patients come from a rural environment, have poor medical education, a number of comorbidities, and who frequently ignore the signs, symptoms and sometimes the treatment offered.

Functional Roles of SPINK1 in Cancers

Serine Peptidase Inhibitor Kazal Type 1 (SPINK1) is a secreted protein known as a protease inhibitor of trypsin in the pancreas. However, emerging evidence shows its function in promoting cancer progression in various types of cancer. SPINK1 modulated tumor malignancies and induced the activation of the downstream signaling of epidermal growth factor receptor (EGFR) in cancer cells, due to the structural similarity with epidermal growth factor (EGF). The discoverable SPINK1 somatic mutations, expressional signatures, and prognostic significances in various types of cancer have attracted attention as a cancer biomarker in clinical applications. Emerging findings further clarify the direct and indirect biological effects of SPINK1 in regulating cancer proliferation, metastasis, drug resistance, transdifferentiation, and cancer stemness, warranting the exploration of the SPINK1-mediated molecular mechanism to identify a therapeutic strategy. In this review article, we first integrate the transcriptomic data of different types of cancer with clinical information and recent findings of SPINK1-mediated malignant phenotypes. In addition, a comprehensive summary of SPINK1 expression in a pan-cancer panel and individual cell types of specific organs at the single-cell level is presented to indicate the potential sites of tumorigenesis, which has not yet been reported. This review aims to shed light on the roles of SPINK1 in cancer and provide guidance and potential directions for scientists in this field.

Secreted BMP antagonists and their role in cancer and bone metastases

Bone morphogenetic proteins (BMPs) are multifunctional secreted cytokines that act in a highly context-dependent manner. BMP action extends beyond the induction of cartilage and bone formation, to encompass pivotal roles in controlling tissue and organ homeostasis during development and adulthood. BMPs signal via plasma membrane type I and type II serine/threonine kinase receptors and intracellular SMAD transcriptional effectors. Exquisite temporospatial control of BMP/SMAD signalling and crosstalk with other cellular cues is achieved by a series of positive and negative regulators at each step in the BMP/SMAD pathway. The interaction of BMP ligand with its receptors is carefully controlled by a diverse set of secreted antagonists that bind BMPs and block their interaction with their cognate BMP receptors. Perturbations in this BMP/BMP antagonist balance are implicated in a range of developmental disorders and diseases, including cancer. Here, we provide an overview of the structure and function of secreted BMP antagonists, and summarize recent novel insights into their role in cancer progression and bone metastasis. Gremlin1 (GREM1) is a highly studied BMP antagonist, and we will focus on this molecule in particular and its role in cancer. The therapeutic potential of pharmacological inhibitors for secreted BMP antagonists for cancer and other human diseases will also be discussed.

High SPINK1 Expression Predicts Poor Prognosis and Promotes Cell Proliferation and Metastasis of Hepatocellular Carcinoma

BACKGROUND

Serine protease inhibitor Kazal type I (SPINK1) is highly expressed and promotes tumor progress in different cancers. This study aimed to evaluate SPINK1's prognostic value and its role in hepatocellular carcinoma (HCC) progress.

METHODS

We use tissue micro-arrays containing 273 tumor and paired para-tumor tissues to evaluate SPINK1's prognostic value in HCC. CCK8 cell proliferation assay, wound healing assays, transwell migration and invasion assays were performed to explore the effect of SPINIK1 on HCC cells. The Cancer Genome Atlas (TCGA) database and Gene set enrichment analysis (GSEA) were used to verify the prognosis value of SPINK1 in HCC and explore the underlying mechanisms.

RESULTS

SPINK1 expression was significantly higher in tumor tissues than paired para-tumor tissues (P < 0.001). Higher SPINK1 expression in tumor was significantly associated with portal vein tumor thrombus formation (P = 0.019) and shorter overall survival (P = 0.029). SPINK1 expression in tumor tissue was an independent predictor for overall survival. SPINK1 increased proliferation (P < 0.001), enhanced migration and invasion ability of HCC cell lines (P < 0.001). GSEA revealed that glycine, serine, threonine and bile acid metabolism may be the underlying mechanism of SPINK1 in HCC.

CONCLUSIONS

In conclusion, high SPINK1 expression is associated with poor prognosis of HCC. SPINK1 promotes proliferation, migration and invasion ability of HCC cells.

Targeting SPINK1 in the damaged tumour microenvironment alleviates therapeutic resistance

Chemotherapy and radiation not only trigger cancer cell apoptosis but also damage stromal cells in the tumour microenvironment (TME), inducing a senescence-associated secretory phenotype (SASP) characterized by chronic secretion of diverse soluble factors. Here we report serine protease inhibitor Kazal type I (SPINK1), a SASP factor produced in human stromal cells after genotoxic treatment. DNA damage causes SPINK1 expression by engaging NF-κB and C/EBP, while paracrine SPINK1 promotes cancer cell aggressiveness particularly chemoresistance. Strikingly, SPINK1 reprograms the expression profile of cancer cells, causing prominent epithelial-endothelial transition (EET), a phenotypic switch mediated by EGFR signaling but hitherto rarely reported for a SASP factor. In vivo, SPINK1 is expressed in the stroma of solid tumours and is routinely detectable in peripheral blood of cancer patients after chemotherapy. Our study substantiates SPINK1 as both a targetable SASP factor and a novel noninvasive biomarker of therapeutically damaged TME for disease control and clinical surveillance.

In vitro 3D blood/lymph-vascularized human stromal tissues for preclinical assays of cancer metastasis

Tumour models mimicking in vivo three-dimensional (3D) microenvironments are of increasing interest in drug discovery because of the limitations inherent to current models. For example, preclinical assays that rely on monolayer or spheroid cell cultures cannot easily predict 3D cancer behaviours because they have no vasculature. Furthermore, there are major differences in cancer behaviour between human and animal experiments. Here, we show the construction of 3D blood/lymph-vascularized human stromal tissues that can be combined with cancer cells to mimic dynamic metastasis for real-time throughput screening of secreted proteinases. We validated this tool using three human carcinoma cell types that are known to invade blood/lymph vessels and promote angiogenesis. These cell types exhibited characteristic haematogenous/lymphogenous metastasis and tumour angiogenesis properties. Importantly, these carcinoma cells selectively secreted different matrix metalloproteinases depending on their metastasis stage and target vasculature, suggesting the possibility of developing drugs that can target each secreted proteinase. We conclude that the 3D tissue tool will be a powerful throughput system for predicting cancer cell responses and time-dependent secretion of molecules in preclinical assays.

Prediction of potential drivers connecting different dysfunctional levels in lung adenocarcinoma via a protein-protein interaction network

Lung cancer is a serious disease that threatens an affected individual's life. Its pathogenesis has not yet to be fully described, thereby impeding the development of effective treatments and preventive measures. "Cancer driver" theory considers that tumor initiation can be associated with a number of specific mutations in genes called cancer driver genes. Four omics levels, namely, (1) methylation, (2) microRNA, (3) mutation, and (4) mRNA levels, are utilized to cluster cancer driver genes. In this study, the known dysfunctional genes of these four levels were used to identify novel driver genes of lung adenocarcinoma, a subtype of lung cancer. These genes could contribute to the initiation and progression of lung adenocarcinoma in at least two levels. First, random walk with restart algorithm was performed on a protein-protein interaction (PPI) network constructed with PPI information in STRING by using known dysfunctional genes as seed nodes for each level, thereby yielding four groups of possible genes. Second, these genes were further evaluated in a test strategy to exclude false positives and select the most important ones. Finally, after conducting an intersection operation in any two groups of genes, we obtained several inferred driver genes that contributed to the initiation of lung adenocarcinoma in at least two omics levels. Several genes from these groups could be confirmed according to recently published studies. The inferred genes reported in this study were also different from those described in a previous study, suggesting that they can be used as essential supplementary data for investigations on the initiation of lung adenocarcinoma. This article is part of a Special Issue entitled: Accelerating Precision Medicine through Genetic and Genomic Big Data Analysis edited by Yudong Cai & Tao Huang.

SPINK6 Promotes Metastasis of Nasopharyngeal Carcinoma via Binding and Activation of Epithelial Growth Factor Receptor

Nasopharyngeal carcinoma has the highest rate of metastasis among head and neck cancers, and distant metastasis is the major reason for treatment failure. The underlying molecular mechanisms of nasopharyngeal carcinoma metastasis are not fully understood. Here, we report the identification of serine protease inhibitor Kazal-type 6 (SPINK6) as a functional regulator of nasopharyngeal carcinoma metastasis via EGFR signaling. SPINK6 mRNA was upregulated in tumor and highly metastatic nasopharyngeal carcinoma cells. Immunohistochemical staining of 534 nasopharyngeal carcinomas revealed elevated SPINK6 expression as an independent unfavorable prognostic factor for overall, disease-free, and distant metastasis-free survival. Ectopic SPINK6 expression promoted in vitro migration and invasion as well as in vivo lymph node metastasis and liver metastasis of nasopharyngeal carcinoma cells, whereas silencing SPINK6 exhibited opposing effects. SPINK6 enhanced epithelial-mesenchymal transition by activating EGFR and the downstream AKT pathway. Inhibition of EGFR with a neutralizing antibody or erlotinib reversed SPINK6-induced nasopharyngeal carcinoma cell migration and invasion. Erlotinib also inhibited SPINK6-induced metastasis in vivo Notably, SPINK6 bound to the EGFR extracellular domain independent of serine protease-inhibitory activity. Overall, our results identified a novel EGFR-activating mechanism in which SPINK6 has a critical role in promoting nasopharyngeal carcinoma metastasis, with possible implications as a prognostic indicator in nasopharyngeal carcinoma patients. Cancer Res; 77(2); 579-89. ©2016 AACR.

Serine protease inhibitor Kazal type 1 (SPINK1) drives proliferation and anoikis resistance in a subset of ovarian cancers

Ovarian cancer represents the most lethal tumor type among malignancies of the female reproductive system. Overall survival rates remain low. In this study, we identify the serine protease inhibitor Kazal type 1 (SPINK1) as a potential therapeutic target for a subset of ovarian cancers. We show that SPINK1 drives ovarian cancer cell proliferation through activation of epidermal growth factor receptor (EGFR) signaling, and that SPINK1 promotes resistance to anoikis through a distinct mechanism involving protease inhibition. In analyses of ovarian tumor specimens from a Mayo Clinic cohort of 490 patients, we further find that SPINK1 immunostaining represents an independent prognostic factor for poor survival, with the strongest association in patients with nonserous histological tumor subtypes (endometrioid, clear cell, and mucinous). This study provides novel insight into the fundamental processes underlying ovarian cancer progression, and also suggests new avenues for development of molecularly targeted therapies.

Serine protease inhibitor Kazal type 1 (SPINK1) as a prognostic marker in stage IV colon cancer patients receiving cetuximab based targeted therapy

BACKGROUND

Serine peptidase inhibitor Kazal type-1 (SPINK1), a trypsin kinase inhibitor, has well established associations with inflammation, cancer cell proliferation and carcinogenesis. However, the role of SPINK1 has not been investigated in stage IV colorectal cancer (CRC) patients receiving cetuximab based targeted therapy. The aim of this study was to evaluate the use of SPINK1 as a biomarker for predicting how patients with end stage CRC respond to anti-epidermal growth factor receptor (EGFR) therapies.

METHODS

Immunohistochemical staining was used for semiquantitative analysis of SPINK1 protein expression in 51 CRC cases. Expression of SPINK1 protein was then analysed to identify correlations with clinicopathological variables.

RESULTS

High SPINK1 expression was significantly associated with males (p=0.018). Kaplan-Meier analyses also showed that patients with high SPINK1 expression had significantly longer overall survival compared with controls (p=0.004). Multivariable analyses showed that SPINK1 expression and tumour size were significantly associated with prognosis (HR 0.416 and 0.437; 95% CI 0.217 to 0.797 and 0.236 to 0.810; p=0.008 and p=0.009, respectively) in these stage IV CRC cases.

CONCLUSIONS

High SPINK1 expression is associated with a good prognosis in stage IV CRC cases receiving cetuximab based targeted therapy. As SPINK1 expression is also an independent prognostic marker in these patients, it has potential use as a biomarker for clinical decision making and for designing personalised targeted therapies.

Emerging Roles of SPINK1 in Cancer

BACKGROUND

Tumor-associated trypsin inhibitor (TATI) was originally isolated from the urine of a patient with ovarian cancer. It was later shown to be produced by many other tumors and several normal tissues. It had earlier been isolated from the pancreas and was hence called pancreatic secretory trypsin inhibitor (PSTI). It belongs to a family of protease inhibitors presently called serine peptidase inhibitor Kazal type (SPINK). In the SPINK family TATI/PSTI is SPINK1, which is the name used in this review.

CONTENT

In addition to being a protease inhibitor, SPINK1 also acts as an acute-phase reactant and a growth factor. Furthermore, it has been shown to modulate apoptosis. Overexpression of SPINK1 predicts an unfavorable outcome in several cancers and determination of SPINK1 in serum can be used to identify patients at increased risk of aggressive disease. Thus serum SPINK1 can be used as a prognostic tumor marker. Because SPINK1 acts as a growth factor and an inhibitor of apoptosis in some cancers, it has also been suggested that it can be a therapeutic target in cancer. However, because SPINK1 is the major physiological inhibitor of trypsin, inhibition of SPINK1 may increase the risk of pancreatitis.

SUMMARY

Taking into account the many functions of SPINK1, assessing the role of SPINK1 in cancer has several potentially important clinical applications ranging from a biomarker to a potential new target for cancer therapy.

Biomarker development, from bench to bedside

This review describes studies performed by our group and other laboratories in the field aimed at development of biomarkers not only for cancer but also for other diseases. The markers covered include tumor-associated trypsin inhibitor (TATI), tumor-associated trypsin (TAT), human chorionic gonadotropin (hCG), prostate-specific antigen (PSA) and their various molecular forms, their biology and diagnostic use. The discovery of TATI was the result of a hypothesis-driven project aimed at finding new biomarkers for ovarian cancer among urinary peptides. TATI has since proved to be a useful prognostic marker for several cancers. Recently, it has been named Serine Peptidase Inhibitor Kazal Type 1 (SPINK1) after being rediscovered by several groups as a tumor-associated peptide by gene expression profiling and proteomic techniques and shown to promote tumor development by stimulating the EGF receptor. To explain why a trypsin inhibitor is strongly expressed in some cancers, research focused on the protease that it inhibited led to the finding of tumor-associated trypsin (TAT). Elevated serum concentrations of TAT-2 were found in some cancer types, but fairly high background levels of pancreatic trypsinogen-2 limited the use of TAT-2 for cancer diagnostics. However, trypsinogen-2 and its complex with α1-protease inhibitor proved to be very sensitive and specific markers for pancreatitis. Studies on hCG were initiated by the need to develop more rapid and sensitive pregnancy tests. These studies showed that serum from men and non-pregnant women contains measurable concentrations of hCG derived from the pituitary. Subsequent development of assays for the subunits of hCG showed that the β subunit of hCG (hCGβ) is expressed at low concentrations by most cancers and that it is a strong prognostic marker. These studies led to the formation of a working group for standardization of hCG determinations and the development of new reference reagents for several molecular forms of hCG. The preparation of intact hCG has been adopted as the fifth international standard by WHO. Availability of several well-defined forms of hCG made it possible to characterize the epitopes of nearly 100 monoclonal antibodies. This will facilitate design of immunoassays with pre-defined specificity. Finally, the discovery of different forms of immunoreactive PSA in serum from a prostate cancer patient led to identification of the complex between PSA and α1-antichymotrypsin, and the use of assays for free and total PSA in serum for improved diagnosis of prostate cancer. Epitope mapping of PSA antibodies and establishment of PSA standards has facilitated establishment well-standardized assays for the various forms of PSA.

SPINK1 promotes colorectal cancer progression by downregulating Metallothioneins expression

Colorectal cancer (CRC) is the third most common cancer in the world, and second leading cause of cancer deaths in the US. Although, anti-EGFR therapy is commonly prescribed for CRC, patients harboring mutations in KRAS or BRAF show poor treatment response, indicating an ardent demand for new therapeutic targets discovery. SPINK1 (serine peptidase inhibitor, Kazal type 1) overexpression has been identified in many cancers including the colon, lung, breast and prostate. Our study demonstrates the functional significance of SPINK1 in CRC progression and metastases. Stable knockdown of SPINK1 significantly decreases cell proliferation, invasion and soft agar colony formation in the colon adenocarcinoma WiDr cells. Conversely, an increase in these oncogenic phenotypes was observed on stimulation with SPINK1-enriched conditioned media (CM) in multiple benign models such as murine colonic epithelial cell lines, MSIE and YAMC (SPINK3-negative). Mechanistically, SPINK1 promotes tumorigenic phenotype by activating phosphatidylinositol 3-kinase (PI3K/AKT) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling pathways, and the SPINK1-positive WiDr cells are sensitive to AKT and MEK inhibitors. Importantly, SPINK1 silencing mediated upregulation of various Metallothionein isoforms, considered as tumor suppressors in CRC, confer sensitivity to doxorubicin, which strengthens the rationale for using the combinatorial treatment approach for the SPINK1-positive CRC patients. Furthermore, in vivo studies using chicken chorioallantoic membrane assay, murine xenograft studies and metastasis models further suggest a pivotal role of SPINK1 in CRC progression and metastasis. Taken together, our study demonstrates an important role for the overexpressed SPINK1 in CRC disease progression, a phenomenon that needs careful evaluation towards effective therapeutic target development.

Serine Protease Inhibitor Kazal Type 1 (SPINK1) Promotes Proliferation of Colorectal Cancer Through the Epidermal Growth Factor as a Prognostic Marker

Serine protease inhibitor Kazal type-1 (SPINK1), a trypsin kinase inhibitor, is involved in inflammation, cell proliferation and carcinogenesis. The role and association between SPINK1, EGFR and Ki-67 in colorectal adenoma (CRA) and colorectal cancer (CRC) are still unknown. In this study, we used immunohistochemical stain to evaluate expression of SPINK1, EGFR and Ki-67 proteins in 30 CRA and 53 CRC patients semiquantitatively, and then analyzed their correlation with clinicopathologic parameters. Our results revealed that SPINK1 expression was noted in the upper and basal parts of the crypts in CRA and was more intensely related with cellular atypia. EGFR expression was found in 13 out of 30 adenomas, including 9 out of 15 adenomas with dysplasia or synchronous CRC (60 %), and 4 out of 15 adenomas without dysplasia (26.7 %). In CRC, high SPINK1 expression was significantly associated with males (p = 0.041) and advanced disease stage (p = 0.015). EGFR positivity was significantly correlated with higher T stage (p = 0.004) and disease stage (stage I-IV, p = 0.017; early vs. late, p = 0.015). Pearson's correlation showed positive correlation between the SPINK1 intensity and EGFR immunoreactivity (p = 0.011), and Ki-67 and SPINK1 intensity or percentage (p = 0.017 and p = 0.039 respectively). In Kaplan-Meier analyses, patients with high SPINK1 intensity tended to have shorter overall survival (p = 0.03). Concomitant expression of high SPINK1 intensity and EGFR was also identified as being associated with poor prognosis (p = 0.015). In conclusion, high SPINK1 expression is associated with advanced stage and poor prognosis. There is positive correlation between high SPINK1 expression, EGFR immunoreactivity, and high Ki-67 labeling index. The SPINK1 protein seems to play a role in tumor proliferation and malignant transformation through the EGFR pathway. SPINK1 may serve as a prognostic biomarker in therapeutic targeting in the future.

SPINK1 Status in Colorectal Cancer, Impact on Proliferation, and Role in Colitis-Associated Cancer

Colorectal cancer is a major cause of deaths due to cancer; therefore, research into its etiology is urgently needed. Although it is clear that chronic inflammation is a risk factor for colorectal cancer, the details remain uncertain. Serine protease inhibitor, Kazal type 1 (SPINK1) is mainly produced in pancreatic acinar cells. However, SPINK1 is expressed in various cancers and in inflammatory states, such as colon cancer and inflammatory bowel disease. There are structural similarities between SPINK1 and epidermal growth factor (EGF). Hence, it was hypothesized that SPINK1 functions as a growth factor for tissue repair in inflammatory states, and if prolonged, acts as a promoter for cell proliferation in cancerous tissues. Here, immunohistochemical staining for SPINK1 was observed in a high percentage of colorectal cancer patient specimens and SPINK1 induced proliferation of human colon cancer cell lines. To clarify its role in colon cancer in vivo, a mouse model exposed to the colon carcinogen azoxymethane and nongenotoxic carcinogen dextran sodium sulfate revealed that Spink3 (mouse homolog of SPINK1) is overexpressed in cancerous tissues. In Spink3 heterozygous mice, tumor multiplicity and tumor volume were significantly decreased compared with wild-type mice. These results suggest that SPINK1/Spink3 stimulates the proliferation of colon cancer cells and is involved in colorectal cancer progression.

IMPLICATIONS

Evidence suggests that SPINK1 is an important growth factor that connects chronic inflammation and cancer.

Comparison of bioactivities of talactoferrin and lactoferrins from human and bovine milk

OBJECTIVES

Lactoferrin (Lf) is an iron-binding glycoprotein present in high concentration in human milk. It is a pleiotropic protein and is involved in diverse bioactivities, such as stimulation of cell proliferation and differentiation, immune competence, antimicrobial activities, anti-infection, and anticancer activities. Lf has been shown to be partly resistant to proteolysis in the gastrointestinal tract and may thus play important roles in the intestine and liver during infancy. Talactoferrin alfa (TLf) is a recombinant human Lf shown to protect against sepsis and necrotizing enterocolitis as well as cancer. Because bovine Lf (bLf) and human Lf have different amino acid composition and all 3 Lfs differ in glycosylation, they may have different functions/potency. The objective of the present study was to investigate and compare bioactivities of TLf and Lfs from human and bovine milk and thus to provide a better understanding of the bioactivities of different forms of Lf and their potential applications.

METHODS

In the present study, Caco-2 and C3A cells were used as intestine and liver models to evaluate internalization of Lfs by intestine and liver cells, effects of Lfs on cell proliferation and differentiation, growth of enteropathogenic Escherichia coli (EPEC), chemokine (C-C motif) ligand 20 (CCL20) secretion, and transforming growth factor (TGF)-β1 expression. In addition, HT-29 cells were used as a colon cancer cell model to examine the effects of Lfs on apoptosis.

RESULTS

All Lfs significantly enhanced cell proliferation and differentiation, apoptosis, CCL20 secretion, and TGF-β1 expression. They also markedly suppressed growth of EPEC. Compared with bLf, TLf showed stronger effects on suppression of EPEC growth and enhancement of TGF-β1 secretion, whereas bLf exhibited more potent effects on cell differentiation, apoptosis, and CCL20 secretion.

CONCLUSIONS

Our results demonstrate that TLf has several bioactivities similar to human Lf and bLf from milk and may play critical roles in immune and intestinal development in infants as well as having anti-cancer activities in adults. TLf and bLf may be used for different applications owing to their various potencies. TLf may preferentially be used for anti-bacterial applications, whereas bLf may be used for cancer therapy because it exhibits stronger effects on CCL20 secretion, cell differentiation, and apoptosis.

Application of an electrochemical immunosensor with a MWCNT/PDAA modified electrode for detection of serum trypsin

Objective: To establish an electrochemical immunosensor for the determination of serum trypsin levels using a multiwall carbon nanotubes (MWCNTs)-composite-modified electrode. Method: A MWCNT composite coated on the surface of bare gold electrodes was used for fixation of an anti-trypsin antibody. The assembly process and the performance indicators, including sensitivity, linear range of detection, anti-jamming performance, and stability, of the electrochemical immunosensor were examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Results: With optimized experimental conditions, the difference of the current value measured by differential pulse voltammetry (DPV) showed a linear relationship with the concentration of serum trypsin within 0.10–100 ng/mL. The detection limit for trypsin using this sensor was 0.002 ng/mL. Conclusions: The electrochemical immunosensor built using the MWCNT-composite-modified electrode is simple to operate and has a fast response time, along with a wide linear range, high sensitivity, and accuracy, making it suitable for serum trypsin detection.

Inflammation to cancer: The molecular biology in the pancreas (Review)

Inflammatory responses are known to be correlated with cancer initiation and progression, and exploration of the route from inflammation to cancer makes a great contribution in elucidating the mechanisms underlying cancer development. Pancreatic cancer (PC) is a lethal disease with a low radical-resection rate and a poor prognosis. As chronic pancreatitis is considered to be a significant etiological factor for PC development, the current review aims to describe the molecular pathways from inflammation to pancreatic carcinogenesis, in support of the strategies for the prevention, diagnosis and treatment of PC.

Proteomics, genomics and transcriptomics: their emerging roles in the discovery and validation of colorectal cancer biomarkers

Colorectal cancer (CRC) is the second most common cancer in females and the third in males. Since CRC is often diagnosed at an advanced stage when prognosis is poor, identification of biomarkers for early diagnosis is urgently required. Recent advances in proteomics, genomics and transcriptomics have facilitated high-throughput profiling of data generated from CRC-related genes and proteins, providing a window of information for biomarker discovery and validation. However, transfer of candidate biomarkers from bench to bedside remains a dilemma. In this review, we will discuss emerging proteomic technologies and highlight various sample types utilized for proteomics-based identification of CRC biomarkers. Moreover, recent breakthroughs in genomics and transcriptomics for the identification of CRC biomarkers, with particular emphasis on the merits of emerging methylomic and miRNAomic strategies, will be discussed. Integration of proteomics, genomics and transcriptomics will facilitate the discovery and validation of CRC biomarkers leading to the emergence of personalized medicine.

Human colonic crypts in culture: segregation of immunochemical markers in normal versus adenoma-derived

In order to advance a culture model of human colonic neoplasia, we developed methods for the isolation and in vitro maintenance of intact colonic crypts from normal human colon tissue and adenomas. Crypts were maintained in three-dimensional Matrigel culture with a simple, serum-free, low Ca(2+) (0.15 mM) medium. Intact colonic crypts from normal human mucosa were viably maintained for 3-5 days with preservation of the in situ crypt-like architecture, presenting a distinct base and apex. Abnormal structures from adenoma tissue could be maintained through multiple passages (up to months), with expanding buds/tubules. Immunohistochemical markers for intestinal stem cells (Lgr5), growth (Ki67), differentiation (E-cadherin, cytokeratin 20 (CK20) and mucin 2 (MUC2)) and epithelial turnover (Bax, cleaved Caspase-3), paralleled the changes in function. The epithelial cells in normal crypts followed the physiological sequence of progression from proliferation to differentiation to dissolution in a spatially and temporally appropriate manner. Lgr5 expression was seen in a few basal cells of freshly isolated crypts, but was not detected after 1-3 days in culture. After 24 h in culture, crypts from normal colonic tissue continued to show strong Ki67 and MUC2 expression at the crypt base, with a gradual decrease over time such that by days 3-4 Ki67 was not expressed. The differentiation marker CK20 increased over the same period, eventually becoming intense throughout the whole crypt. In adenoma-derived structures, expression of markers for all stages of progression persisted for the entire time in culture. Lgr5 showed expression in a few select cells after months in culture. Ki67 and MUC2 were largely associated with the proliferative budding regions while CK20 was localized to the parent structure. This ex vivo culture model of normal and adenomatous crypts provides a readily accessible tool to help understand the growth and differentiation process in human colonic epithelium.

Colon cancer cells escape 5FU chemotherapy-induced cell death by entering stemness and quiescence associated with the c-Yes/YAP axis

PURPOSE

Metastasis and drug resistance are the major limitations in the survival and management of patients with cancer. This study aimed to identify the mechanisms underlying HT29 colon cancer cell chemoresistance acquired after sequential exposure to 5-fluorouracil (5FU), a classical anticancer drug for treatment of epithelial solid tumors. We examined its clinical relevance in a cohort of patients with colon cancer with liver metastases after 5FU-based neoadjuvant chemotherapy and surgery.

RESULTS

We show that a clonal 5F31 cell population, resistant to 1 μmol/L 5FU, express a typical cancer stem cell-like phenotype and enter into a reversible quiescent G0 state upon reexposure to higher 5FU concentrations. These quiescent cells overexpressed the tyrosine kinase c-Yes that became activated and membrane-associated upon 5FU exposure. This enhanced signaling pathway induced the dissociation of the Yes/YAP (Yes-associated protein) molecular complex and depleted nuclear YAP levels. Consistently, YES1 silencing decreased nuclear YAP accumulation and induced cellular quiescence in 5F31 cells cultured in 5FU-free medium. Importantly, YES1 and YAP transcript levels were higher in liver metastases of patients with colon cancer after 5FU-based neoadjuvant chemotherapy. Moreover, the YES1 and YAP transcript levels positively correlated with colon cancer relapse and shorter patient survival (P < 0.05 and P < 0.025, respectively).

CONCLUSIONS

We identified c-Yes and YAP as potential molecular targets to eradicate quiescent cancer cells and dormant micrometastases during 5FU chemotherapy and resistance and as predictive survival markers for colon cancer.

A novel discriminant score based on tumor-associated trypsin inhibitor for accurate diagnosis of metastasis in patients with breast cancer

Invasion and metastasis of solid tumors require proteolytic enzymes for degradation of the basal membrane and extracellular matrix. Currently, there are no reliable methodologies to predict the risk for metastatic disease. In this context, our aim has been focused on the development of a noninvasive score based on tumor-associated trypsin inhibitor (TATI) for the assessment of metastasis in patients with breast cancer. TATI, trypsin, and soluble epidermal growth factor receptor (sEGFR) were assayed by enzyme-linked immunosorbent assay. CA 15.3 serum level was assayed by microparticle enzyme immunoassay in 265 patients with breast cancer. Statistical analyses were performed by logistic regression and receiver operating characteristic analysis curves. Using multivariate discriminant analysis, a score is selected based on absolute values of the four biochemical markers: TATI-metastatic breast cancer score (TATI-MBCS) = [0.03 × CA 15.3 (U/L) + 0.039 × TATI (ng/ml) + 0.04 × trypsin (ng/ml) + 0.023 × sEGFR (ng/ml) - 6.49 (numerical constant)]. This function correctly classified 84% of metastatic breast cancer at cutoff value = 0.62 (i.e., greater than 0.62 indicates patients with metastatic breast cancer and less than 0.62 indicates patients with nonmetastatic breast cancer). In conclusion, TATI-MBCS is a novel, noninvasive, and simple score which can be applied to discriminate patients with metastatic breast cancer.

Role of Intrapancreatic SPINK1/Spink3 Expression in the Development of Pancreatitis

Studies on hereditary pancreatitis have provided evidence in favor of central role for trypsin activity in the disease. Identification of genetic variants of trypsinogen linked the protease to the onset of pancreatitis, and biochemical characterization proposed an enzymatic gain of function as the initiating mechanism. Mutations of serine protease inhibitor Kazal type 1 gene (SPINK1) are shown to be associated with hereditary pancreatitis. We previously reported that Spink3 (a mouse homolog gene of human SPINK1) deficient mice showed excessive autophagy, followed by inappropriate trypsinogen activation in the exocrine pancreas. These data indicate that the role of SPINK1/Spink3 is not only trypsin inhibitor, but also negative regulator of autophagy. On the other hand, recent studies showed that high levels of SPINK1 protein detected in a serum or urine were associated with adverse outcome in various cancer types. It has been suggested that expression of SPINK1 and trypsin is balanced in normal tissue, but this balance could be disrupted during tumor progression. Based on the structural similarity between SPINK1 and epidermal growth factor (EGF), we showed that SPINK1 protein binds and activates EGF receptor, thus acting as a growth factor on tumor cell lines. In this review, we summarize the old and new roles of SPINK1/Spink3 in trypsin inhibition, autophagy, and cancer cell growth. These new functions of SPINK1/Spink3 may be related to the development of chronic pancreatitis.

Global alteration in gene expression profiles of deciduas from women with idiopathic recurrent pregnancy loss

Recurrent pregnancy loss (RPL) occurs in ∼5% of women. However, the etiology is still poorly understood. Defects in decidualization of the endometrium during early pregnancy contribute to several pregnancy complications, such as pre-eclampsia and intrauterine growth restriction (IUGR), and are believed to be important in the pathogenesis of idiopathic RPL. We performed microarray analysis to identify gene expression alterations in the deciduas of idiopathic RPL patients. Control patients had one antecedent term delivery, but were undergoing dilation and curettage for current aneuploid miscarriage. Gene expression differences were evaluated using both pathway and gene ontology (GO) analysis. Selected genes were validated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). A total of 155 genes were found to be significantly dysregulated in the deciduas of RPL patients (>2-fold change, P < 0.05), with 22 genes up-regulated and 133 genes down-regulated. GO analysis linked a large percentage of genes to discrete biological functions, including immune response (23%), cell signaling (18%) and cell invasion (17.1%), and pathway analysis revealed consistent changes in both the interleukin 1 (IL-1) and IL-8 pathways. All genes in the IL-8 pathway were up-regulated while genes in the IL-1 pathway were down-regulated. Although both pathways can promote inflammation, IL-1 pathway activity is important for normal implantation. Additionally, genes known to be critical for degradation of the extracellular matrix, including matrix metalloproteinase 26 and serine peptidase inhibitor Kazal-type 1, were also highly up-regulated. In this first microarray approach to decidual gene expression in RPL patients, our data suggest that dysregulation of genes associated with cell invasion and immunity may contribute significantly to idiopathic recurrent miscarriage.

Tumour-associated trypsin inhibitor TATI is a prognostic marker in colorectal cancer

BACKGROUND

The tumour-associated trypsin inhibitor TATI is expressed together with trypsin in many cancer forms, and an elevated serum level associates with poor prognosis. TATI can reduce tissue destruction by inhibiting trypsin and other proteinases, and in some cancer forms, its high tissue expression is associated with favourable prognosis. We analyzed the prognostic values of TATI, trypsinogen-1 and trypsinogen-2 immunoexpression from tissue array blocks constructed from surgical specimens of 592 colorectal cancer patients.

RESULTS

TATI positivity correlated negatively with differentiation (p < 0.001) and positively with the histological type of adenocarcinoma (p < 0.001). Trypsinogen-1 and trypsinogen-2 positivity correlated with Dukes' stage (p = 0.045, p = 0.050); the percentage of trypsinogen-1- and trypsinogen-2-positive tumours was lower in metastasized (Dukes' stage C-D) than in local (Dukes' stage A-B) disease. In addition, trypsinogen-2 correlated inversely with differentiation (p = 0.012). In univariate analysis, the expression of TATI associated with more favourable cancer-specific survival (p = 0.010). In multivariate analysis, low TATI (p = 0.044), age (p < 0.001), Dukes' stage (p < 0.001), tumour differentiation (p = 0.020) and location in the rectum (p = 0.006) were independent prognostic factors for adverse outcome. Furthermore, TATI expression was an independent prognostic factor in a subgroup of trypsinogen-1- (p = 0.007) and trypsinogen-2-positive (p = 0.006) tumours.

CONCLUSION

TATI tissue expression is an independent prognostic marker in colorectal cancer.

The tumor ecosystem regulates the roads for invasion and metastasis

Invasive cancer cells traffic from the primary tumor ecosystem to distant metastatic sites. Experimental data are reviewed with a focus on cross-signaling between cancer cells and host cells such as myofibroblasts and mesenchymal stem cells. Invasion-associated cellular activities, namely vesicle exocytosis and epithelial to mesenchymal transition, depend on complex networks of signal transduction pathways including activation of tyrosine kinases, the Rab, Rac and Rho family of small GTPases and cadherin signaling. As clinical validation, some cell types or molecules implicated in invasion-associated activities may serve as prognostic/predictive biomarker or as target for patient-tailored therapy.

Effects of radiation therapy on tissue and serum concentrations of tumour associated trypsin inhibitor and their prognostic significance in rectal cancer patients

BACKGROUND

We have previously demonstrated that elevated concentrations of tumour-associated trypsin inhibitor (TATI) in both tumour tissue (t-TATI) and in serum (s-TATI) are associated with a poor prognosis in colorectal cancer patients. It was also found that s-TATI concentrations were lower in patients with rectal cancer compared to patients with colon cancer. In this study, we investigated the effects of neoadjuvant radiotherapy (RT) on concentrations of t-TATI and s-TATI in patients with rectal cancer.

METHODS

TATI was analysed in serum, normal mucosa and tumour tissue collected at various time points in 53 rectal cancer patients enrolled in a case-control study where 12 patients received surgery alone, 20 patients 5 × 5 Gy (short-term) preoperative RT and 21 patients 25 × 2 Gy (long-term) preoperative RT. T-TATI was analysed by immunohistochemistry and s-TATI was determined by an immunofluorometric assay. Mann-Whitney U test and Wilcoxon Z (Z) test were used to assess t-TATI and s-TATI concentrations in relation to RT. Spearman's correlation (R) test was used to explore the associations between t-TATI, s-TATI and clinicopathological parameters. Overall survival (OS) according to high and low t-TATI and s-TATI concentrations was estimated by classification and regression tree analysis, Kaplan-Meier analysis and the log rank test.

RESULTS

RT did not affect concentrations of t-TATI or s-TATI. In patients receiving short-term but not long-term RT, s-TATI concentrations were significantly higher 4 weeks post surgery than in serum drawn prior to surgery (Z = -3.366, P < 0.001). T-TATI expression correlated with male gender (R = 0.406, P = 0.008). High t-TATI expression in surgical specimens was associated with a significantly shorter OS (P = 0.045). S-TATI concentrations in serum drawn at all time points were associated with an impaired OS (P = 0.035 before RT, P = 0.001 prior to surgery, P = 0.043 post surgery). At all time points, s-TATI correlated with higher age (P < 0.001-0.021) and with increased s-creatinine concentrations assessed prior to surgery (P = 0.041).

CONCLUSIONS

The results presented here further validate the utility of t-TATI and s-TATI as prognostic biomarkers in patients with rectal cancer, independent of neoadjuvant RT.

Human colon tissue in organ culture: preservation of normal and neoplastic characteristics

Normal and neoplastic human colon tissue obtained at surgery was used to establish conditions for organ culture. Optimal conditions included an atmosphere of 5% CO2 and 95% O2; tissue partially submerged with mucosa at the gas interface; and serum-free medium with 1.5 mM Ca2+ and a number of growth supplements. Histological, histochemical, and immunohistochemical features that distinguish normal and neoplastic tissue were preserved over a 2-d period. With normal tissue, this included the presence of elongated crypts with small, densely packed cells at the crypt base and mucin-containing goblet cells in the upper portion. Ki67 staining, for proliferating cells, was confined to the lower third of the crypt, while expression of extracellular calcium-sensing receptor was seen in the upper third and surface epithelium. E-cadherin and β-catenin were expressed throughout the epithelium and confined to the cell surface. In tumor tissue, the same disorganized, abnormal glandular structures seen at time zero were present after 2 d. The majority of cells in these structures were mucin-poor, but occasional goblet cells were seen and mucin staining was present. Ki67 staining was seen throughout the abnormal epithelium and calcium-sensing receptor expression was weak and variable. E-cadherin was seen at the cell surface (similar to normal tissue), but in some places, there was diffuse cytoplasmic staining. Finally, intense cytoplasmic and nuclear β-catenin staining was observed in cultured neoplastic tissue.

Therapeutic targeting of SPINK1-positive prostate cancer

Gene fusions involving ETS (erythroblastosis virus E26 transformation-specific) family transcription factors are found in ~50% of prostate cancers and as such can be used as a basis for the molecular subclassification of prostate cancer. Previously, we showed that marked overexpression of SPINK1 (serine peptidase inhibitor, Kazal type 1), which encodes a secreted serine protease inhibitor, defines an aggressive molecular subtype of ETS fusion-negative prostate cancers (SPINK1+/ETS⁻, ~10% of all prostate cancers). Here, we examined the potential of SPINK1 as an extracellular therapeutic target in prostate cancer. Recombinant SPINK1 protein (rSPINK1) stimulated cell proliferation in benign RWPE as well as cancerous prostate cells. Indeed, RWPE cells treated with either rSPINK1 or conditioned medium from 22RV1 prostate cancer cells (SPINK1+/ETS⁻) significantly increased cell invasion and intravasation when compared with untreated cells. In contrast, knockdown of SPINK1 in 22RV1 cells inhibited cell proliferation, cell invasion, and tumor growth in xenograft assays. 22RV1 cell proliferation, invasion, and intravasation were attenuated by a monoclonal antibody (mAb) to SPINK1 as well. We also demonstrated that SPINK1 partially mediated its neoplastic effects through interaction with the epidermal growth factor receptor (EGFR). Administration of antibodies to SPINK1 or EGFR (cetuximab) in mice bearing 22RV1 xenografts attenuated tumor growth by more than 60 and 40%, respectively, or ~75% when combined, without affecting PC3 xenograft (SPINK1⁻/ETS⁻) growth. Thus, this study suggests that SPINK1 may be a therapeutic target in a subset of patients with SPINK1+/ETS⁻ prostate cancer. Our results provide a rationale for both the development of humanized mAbs to SPINK1 and evaluation of EGFR inhibition in SPINK1+/ETS⁻ prostate cancers.

Combined genomic and phenotype screening reveals secretory factor SPINK1 as an invasion and survival factor associated with patient prognosis in breast cancer

Secretory factors that drive cancer progression are attractive immunotherapeutic targets. We used a whole-genome data-mining approach on multiple cohorts of breast tumours annotated for clinical outcomes to discover such factors. We identified Serine protease inhibitor Kazal-type 1 (SPINK1) to be associated with poor survival in estrogen receptor-positive (ER+) cases. Immunohistochemistry showed that SPINK1 was absent in normal breast, present in early and advanced tumours, and its expression correlated with poor survival in ER+ tumours. In ER− cases, the prognostic effect did not reach statistical significance. Forced expression and/or exposure to recombinant SPINK1 induced invasiveness without affecting cell proliferation. However, down-regulation of SPINK1 resulted in cell death. Further, SPINK1 overexpressing cells were resistant to drug-induced apoptosis due to reduced caspase-3 levels and high expression of Bcl2 and phospho-Bcl2 proteins. Intriguingly, these anti-apoptotic effects of SPINK1 were abrogated by mutations of its protease inhibition domain. Thus, SPINK1 affects multiple aggressive properties in breast cancer: survival, invasiveness and chemoresistance. Because SPINK1 effects are abrogated by neutralizing antibodies, we suggest that SPINK1 is a viable potential therapeutic target in breast cancer.

Stromal microenvironment processes unveiled by biological component analysis of gene expression in xenograft tumor models

Background

Mouse xenograft models, in which human cancer cells are implanted in immune-suppressed mice, have been popular for studying the mechanisms of novel therapeutic targets, tumor progression and metastasis. We hypothesized that we could exploit the interspecies genetic differences in these experiments. Our purpose is to elucidate stromal microenvironment signals from probes on human arrays unintentionally cross-hybridizing with mouse homologous genes in xenograft tumor models.

Results

By identifying cross-species hybridizing probes from sequence alignment and cross-species hybridization experiment for the human whole-genome arrays, deregulated stromal genes can be identified and then their biological significance were predicted from enrichment studies. Comparing these results with those found by the laser capture microdissection of stromal cells from tumor specimens resulted in the discovery of significantly enriched stromal biological processes.

Conclusions

Using this method, in addition to their primary endpoints, researchers can leverage xenograft experiments to better characterize the tumor microenvironment without additional costs. The Xhyb probes and R script are available at http://www.lussierlab.org/publications/Stroma

Increased serum levels of tumour-associated trypsin inhibitor independently predict a poor prognosis in colorectal cancer patients

Background

There is an insufficient number of reliable prognostic and response predictive biomarkers in colorectal cancer (CRC) management. In a previous study, we found that high tumour tissue expression of tumour-associated trypsin inhibitor (TATI) correlated with liver metastasis and an impaired prognosis in CRC. The aim of this study was to investigate the prognostic validity of serum TATI (s-TATI) in CRC. We further assessed the prognostic value of carcino-embryonic antigen in serum (s-CEA) and the interrelationship between s-TATI and TATI in tissue (t-TATI).

Methods

Using an immunofluorometric assay, s-TATI levels were analysed in 334 preoperatively collected serum samples from patients with CRC. Spearman's Rho and Chi-square test were used for analysis of correlations between s-TATI and clinicopathological parameters, s-CEA and t-TATI. Kaplan-Meier analysis and Cox uni- and multivariate regression analysis were used to estimate disease free survival (DFS) and overall survival (OS) according to quartiles of s-TATI and cut-offs derived from ROC-analysis of s-TATI and s-CEA.

Results

Increased levels of s-TATI were associated with a reduced DFS (HR = 2.00; 95% CI 1.40-2.84, P < 0.001) and OS (HR = 2.40; 95% CI 1.74-3.33, P < 0.001). (HR = 2.89; 95% CI 1.96-4.25). This association remained significant in multivariate analysis. The association for OS remained significant in multivariate analysis (HR = 1.51; 95% CI 1.03-2.22, P = 0.034 for DFS and HR = 1.78; 95% CI 1.25-2.53, P = 0.001 for OS). There was no significant association between s-TATI and t-TATI. The prognostic value of s-CEA was also evident, but somewhat weaker than for s-TATI.

Conclusions

High preoperative s-TATI levels predict a poor prognosis in patients with CRC, and the prognostic value is independent of established prognostic parameters and t-TATI expression. These data suggest that s-TATI might be a useful marker for prognostic stratification in CRC.

Pancreatic secretory trypsin inhibitor: More than a trypsin inhibitor

Kazal-type serine protease inhibitor is one of the most important and widely distributed protease inhibitor families. Pancreatic secretory trypsin inhibitor (PSTI), also known as serine protease inhibitor Kazal type I(SPINK1), binds rapidly to trypsin, inhibits its activity and is likely to protect the pancreas from prematurely activated trypsinogen. Therefore, it is an important factor in the onset of pancreatitis. Recent studies found that PSTI/SPINK1 is also involved in self-regulation of acinar cell phagocytosis, proliferation and growth of a variety of cell lines. In addition, it takes part in the response to inflammatory factor or injury and is highly related to adult type II citrullinemia.

Autocrine induction of invasive and metastatic phenotypes by the MIF-CXCR4 axis in drug-resistant human colon cancer cells

Metastasis and drug resistance are major problems in cancer chemotherapy. The purpose of this work was to analyze the molecular mechanisms underlying the invasive potential of drug-resistant colon carcinoma cells. Cellular models included the parental HT-29 cell line and its drug-resistant derivatives selected after chronic treatment with either 5-fluorouracil, methotrexate, doxorubicin, or oxaliplatin. Drug-resistant invasive cells were compared with noninvasive cells using cDNA microarray, quantitative reverse transcription-PCR, flow cytometry, immunoblots, and ELISA. Functional and cellular signaling analyses were undertaken using pharmacologic inhibitors, function-blocking antibodies, and silencing by retrovirus-mediated RNA interference. 5-Fluorouracil- and methotrexate-resistant HT-29 cells expressing an invasive phenotype in collagen type I and a metastatic behavior in immunodeficient mice exhibited high expression of the chemokine receptor CXCR4. Macrophage migration-inhibitory factor (MIF) was identified as the critical autocrine CXCR4 ligand promoting invasion in drug-resistant colon carcinoma HT-29 cells. Silencing of CXCR4 and impairing the MIF-CXCR4 signaling pathways by ISO-1, pAb FL-115, AMD-3100, monoclonal antibody 12G5, and BIM-46187 abolished this aggressive phenotype. Induction of CXCR4 was associated with the upregulation of two genes encoding transcription factors previously shown to control CXCR4 expression (HIF-2alpha and ASCL2) and maintenance of intestinal stem cells (ASCL2). Enhanced CXCR4 expression was detected in liver metastases resected from patients with colon cancer treated by the standard FOLFOX regimen. Combination therapies targeting the CXCR4-MIF axis could potentially counteract the emergence of the invasive metastatic behavior in clonal derivatives of drug-resistant colon cancer cells.

ETS gene fusions in prostate cancer

Chromosomal rearrangements that result in high level expression of ETS gene family members are common events in human prostate cancer. Most frequently, the androgen-activated gene TMPRSS2 is found fused to the ERG gene. Fusions involving ETV1, ETV4 and ETV5 occur less frequently but exhibit greater variability in fusion structure with 12 unique 5' fusion partners identified so far. ETS gene rearrangement seems to be a key event in driving prostate neoplastic development: the rearrangement occurs as an early event and continues to be expressed in metastatic and castration-resistant disease. However, ETS alterations seem insufficient on their own to induce cancer formation. No consistent associations are seen between the presence of ETS alteration and clinical outcome, with the possible exception that duplication of rearranged ERG, reflecting aneuploidy, is associated with poor outcome. Thus, factors other than ERG gene status may be the major determinants of poor clinical outcome. Expression signatures of prostate cancers containing the TMPRSS2-ERG fusion suggest involvement of beta-estradiol signaling, and reveal higher levels of expression of HDAC1 and ion channel genes when compared to cancers that lack the rearrangement. These observations suggest new therapeutic possibilities for patients harboring ETS gene fusions.

Molecular characterisation of ERG, ETV1 and PTEN gene loci identifies patients at low and high risk of death from prostate cancer

BACKGROUND

The discovery of ERG/ETV1 gene rearrangements and PTEN gene loss warrants investigation in a mechanism-based prognostic classification of prostate cancer (PCa). The study objective was to evaluate the potential clinical significance and natural history of different disease categories by combining ERG/ETV1 gene rearrangements and PTEN gene loss status.

METHODS

We utilised fluorescence in situ hybridisation (FISH) assays to detect PTEN gene loss and ERG/ETV1 gene rearrangements in 308 conservatively managed PCa patients with survival outcome data.

RESULTS

ERG/ETV1 gene rearrangements alone and PTEN gene loss alone both failed to show a link to survival in multivariate analyses. However, there was a strong interaction between ERG/ETV1 gene rearrangements and PTEN gene loss (P<0.001). The largest subgroup of patients (54%), lacking both PTEN gene loss and ERG/ETV1 gene rearrangements comprised a 'good prognosis' population exhibiting favourable cancer-specific survival (85.5% alive at 11 years). The presence of PTEN gene loss in the absence of ERG/ETV1 gene rearrangements identified a patient population (6%) with poorer cancer-specific survival that was highly significant (HR=4.87, P<0.001 in multivariate analysis, 13.7% survival at 11 years) when compared with the 'good prognosis' group. ERG/ETV1 gene rearrangements and PTEN gene loss status should now prospectively be incorporated into a predictive model to establish whether predictive performance is improved.

CONCLUSIONS

Our data suggest that FISH studies of PTEN gene loss and ERG/ETV1 gene rearrangements could be pursued for patient stratification, selection and hypothesis-generating subgroup analyses in future PCa clinical trials and potentially in patient management.

High expression of tumour-associated trypsin inhibitor correlates with liver metastasis and poor prognosis in colorectal cancer

Increased expression of tumour-associated trypsin inhibitor (TATI) in tumour tissue and/or serum has been associated with poor survival in various cancer forms. Moreover, a proinvasive function of TATI has been shown in colon cancer cell lines. In this study, we have examined the prognostic significance of tumour-specific TATI expression in colorectal cancer, assessed by immunohistochemistry (IHC) on tissue microarrays (TMAs) with tumour specimens from two independent patient cohorts. Kaplan–Meier analysis and Cox proportional hazards modelling were used to estimate time to recurrence, disease-free survival and overall survival. In both cohorts, a high (>50% of tumour cells) TATI expression was an independent predictor of a significantly shorter overall survival. In cohort II, in multivariate analysis including age, gender, disease stage, differentiation grade, vascular invasion and carcinoembryonal antigen (CEA), high TATI expression was associated with a significantly decreased overall survival (HR=1.82; 95% CI=1.19–2.79) and disease-free survival (HR=1.56; 95% CI=1.05–2.32) in curatively treated patients. Moreover, there was an increased risk for liver metastasis in both cohorts that remained significant in multivariate analysis in cohort II (HR=2.85; 95% CI=1.43–5.66). In conclusion, high TATI expression is associated with liver metastasis and is an independent predictor of poor prognosis in patients with colorectal cancer.

Aldo-keto reductases from the AKR1B subfamily: retinoid specificity and control of cellular retinoic acid levels

NADP(H)-dependent cytosolic aldo-keto reductases (AKRs) have been added to the group of enzymes which contribute to oxidoreductive conversions of retinoids. Recently, we found that two members from the AKR1B subfamily (AKR1B1 and AKRB10) were active in the reduction of all-trans- and 9-cis-retinaldehyde, with K(m) values in the micromolar range, but with very different k(cat) values. With all-trans-retinaldehyde, AKR1B10 shows a much higher k(cat) value than AKR1B1 (18 min(-1)vs. 0.37 min(-1)) and a catalytic efficiency comparable to that of the best retinaldehyde reductases. Structural, molecular dynamics and site-directed mutagenesis studies on AKR1B1 and AKR1B10 point that subtle differences at the entrance of their retinoid-binding site, especially at position 125, are determinant for the all-trans-retinaldehyde specificity of AKR1B10. Substitutions in the retinoid cyclohexene ring, analyzed here further, also influence such specificity. Overall it is suggested that the rate-limiting step in the reaction mechanism with retinaldehyde differs between AKR1B1 and AKR1B10. In addition, we demonstrate here that enzymatic activity of AKR1B1 and AKR1B10 lowers all-trans- and 9-cis-retinoic acid-dependent trans-activation in living cells, indicating that both enzymes may contribute to pre-receptor regulation of retinoic acid and retinoid X nuclear receptors. This result supports that overexpression of AKR1B10 in cancer (an updated review on this topic is included) may contribute to dedifferentiation and tumor development.