Serine protease inhibitor Kazal type 1 promotes proliferation of pancreatic cancer cells through the epidermal growth factor receptor

Trypsin in pancreatitis: The culprit, a mediator, or epiphenomenon?

Pancreatitis is a common, life-threatening inflammatory disease of the exocrine pancreas. Its pathogenesis remains obscure, and no specific or effective treatment is available. Gallstones and alcohol excess are major etiologies of pancreatitis; in a small portion of patients the disease is hereditary. Pancreatitis is believed to be initiated by injured acinar cells (the main exocrine pancreas cell type), leading to parenchymal necrosis and local and systemic inflammation. The primary function of these cells is to produce, store, and secrete a variety of enzymes that break down all categories of nutrients. Most digestive enzymes, including all proteases, are secreted by acinar cells as inactive proforms (zymogens) and in physiological conditions are only activated when reaching the intestine. The generation of trypsin from inactive trypsinogen in the intestine plays a critical role in physiological activation of other zymogens. It was proposed that pancreatitis results from proteolytic autodigestion of the gland, mediated by premature/inappropriate trypsinogen activation within acinar cells. The intra-acinar trypsinogen activation is observed in experimental models of acute and chronic pancreatitis, and in human disease. On the basis of these observations, it has been considered the central pathogenic mechanism of pancreatitis - a concept with a century-old history. This review summarizes the data on trypsinogen activation in experimental and genetic rodent models of pancreatitis, particularly the more recent genetically engineered mouse models that mimic mutations associated with hereditary pancreatitis; analyzes the mechanisms mediating trypsinogen activation and protecting the pancreas against its' damaging effects; discusses the gaps in our knowledge, potential therapeutic approaches, and directions for future research. We conclude that trypsin is not the culprit in the disease pathogenesis but, at most, a mediator of some pancreatitis responses. Therefore, the search for effective therapies should focus on approaches to prevent or normalize other intra-acinar pathologic processes, such as defective autophagy leading to parenchymal cell death and unrelenting inflammation.

An integrative proteomics approach identifies tyrosine kinase KIT as a therapeutic target for SPINK1-positive prostate cancer

Elevated serine peptidase inhibitor, Kazal type 1 (SPINK1) levels in ∼10%-25% of prostate cancer (PCa) patients associate with aggressive phenotype, for which there are limited treatment choices and dismal clinical outcomes. Using an integrative proteomics approach involving label-free phosphoproteome and proteome profiling, we delineated the downstream signaling pathways involved in SPINK1-mediated tumorigenesis and identified tyrosine kinase KIT as highly enriched. Furthermore, high to moderate levels of KIT expression were detected in ∼85% of SPINK1-positive PCa specimens. We show KIT signaling orchestrates SPINK1-mediated oncogenesis, and treatment with KIT inhibitor reduces tumor growth and metastases in preclinical mice models. Mechanistically, KIT signaling modulates WNT/β-catenin pathway and confers stemness-related features in PCa. Notably, inhibiting KIT signaling led to restoration of AR/REST levels, forming a feedback loop enabling SPINK1 repression. Overall, we uncover the role of KIT signaling downstream of SPINK1 in maintaining lineage plasticity and provide distinct treatment modalities for advanced-stage SPINK1-positive patients.

PTEN, ERG, SPINK1, and TFF3 Status and Relationship in a Prostate Cancer Cohort from Jordanian Arab Population

Background and Objectives: Prognostic biomarkers in prostate cancer (PCa) include PTEN, ERG, SPINK1, and TFF3. Their relationships and patterns of expression in PCa in developing countries, including Jordan, have not yet been investigated. Materials and Methods: A tissue microarray (TMA) of PCa patients was taken from paraffin-embedded tissue blocks for 130 patients. PTEN, ERG, SPINK1, and TFF3 expression profiles were examined using immunohistochemistry (IHC) and correlated with each other and other clinicopathological factors. Results: PTEN loss of any degree was observed in 42.9% of PCa cases. ERG and TFF3 were expressed in 59.3% and 46.5% of PCa cases, respectively. SPINK1 expression was observed in 6 out of 104 PCa cases (5.4%). Among all PCa cases (n = 104), 3.8% (n = 4) showed SPINK1+/ERG+ phenotype, 1.9% (n = 2) showed SPINK1+/ERG- phenotype, 56.7% (n = 59) showed SPINK1-/ERG+ phenotype, and 37.5% showed SPINK1-/ERG- phenotype (n = 39). Among ERG positive cases (n = 63), 6.3% were SPINK1 positive. Among SPINK1 positive cases (n = 6), 66.7% were ERG positive. SPINK1 expression was predominantly observed in a subgroup of cancers that expressed TFF3 (6/6). Additionally, a statistically significant loss of PTEN expression was observed from Gleason Score 6 (GS6) (Grade Group 1 (GG1)) to GS9-10 (GG5); (p-value 0.019). Conclusions: This is the first study to look at the status of the PTEN, ERG, SPINK1, and TFF3 genes in a Jordanian Arab population. Loss of PTEN has been linked to more aggressive prostate cancer with high GSs/GGs. SPINK1 expression was predominantly observed in a subgroup of cancers that expressed TFF3. Our results call for screening these biomarkers for grading and molecular subtyping of the disease.

Transcription activation of SPINK4 by ELF-1 augments progression of colon cancer by regulating biological behaviors

BACKGROUND

SPINK4 was highly expressed in colorectal cancer and resulted in worse prognosis of colorectal cancer patients. However, the expression and function of SPINK4 in colon cancer have not been revealed.

METHODS

Analysis from GEPIA website showed the expression and function of SPINK4 in colon cancer samples. Colon cancer cell lines were applied to detect the biological function of SPINK4. Functionally, the transcriptional factor of SPINK4 has been predicted and verified. Finally, the associations between transcriptional factor and SPINK4 have been confirmed.

RESULTS

SPINK4 expression was obviously increased in colon cancer samples. HCT-116 and DXH-1 cells in si-SPINK4-1 or si-SPINK4-2 group displayed an obvious reduction in its proliferation, cell cycle, invasion and migration compared to those in the si-control group. Moreover, transcriptional factor ELF-1 bound to the promoter of SPINK4 and affected its expression in colon cancer cells. High ELF-1 expression was presented in colon cancer samples and resulted in worse prognosis of colon cancer patients. Additionally, si-SPINK4 antagonized the function of ELF-1 overexpression in modulating colon cancer cell proliferation, cell cycle and mobility.

CONCLUSIONS

Our findings afforded a theoretical basis for further research on the treatment of colon cancer based on the control of ELF-1/SPINK4 expression.

A niche-mimicking polymer hydrogel-based approach to identify molecular targets for tackling human pancreatic cancer stem cells

BACKGROUND

Pancreatic adenocarcinoma (PAAD) is one of the most fatal human cancers, but effective therapies remain to be established. Cancer stem cells (CSCs) are highly resistant to anti-cancer drugs and a deeper understanding of their microenvironmental niche has been considered important to provide understanding and solutions to cancer eradication. However, as the CSC niche is composed of a wide variety of biological and physicochemical factors, the development of multidisciplinary tools that recapitulate their complex features is indispensable. Synthetic polymers have been studied as attractive biomaterials due to their tunable biofunctionalities, while hydrogelation technique further renders upon them a diversity of physical properties, making them an attractive tool for analysis of the CSC niche.

METHODS

To develop innovative materials that recapitulate the CSC niche in pancreatic cancers, we performed polymer microarray analysis to identify niche-mimicking scaffolds that preferentially supported the growth of CSCs. The niche-mimicking activity of the identified polymers was further optimized by polyethylene glycol (PEG)-based hydrogelation. To reveal the biological mechanisms behind the activity of the optimized hydrogels towards CSCs, proteins binding onto the hydrogel were analyzed by liquid chromatography with tandem mass spectrometry (LC-MS/MS), and the potential therapeutic targets were validated by looking at gene expression and patients' outcome in the TCGA database.

RESULTS

PA531, a heteropolymer composed of 2-methoxyethyl methacrylate (MEMA) and 2-(diethylamino)ethyl methacrylate (DEAEMA) (5.5:4.5) that specifically supports the growth and maintenance of CSCs was identified by polymer microarray screening using the human PAAD cell line KLM1. The polymer PA531 was converted into five hydrogels (PA531-HG1 to HG5) and developed to give an optimized scaffold with the highest CSC niche-mimicking activities. From this polymer that recapitulated CSC binding and control, the proteins fetuin-B and angiotensinogen were identified as candidate target molecules with clinical significance due to the correlation between gene expression levels and prognosis in PAAD patients and the proteins associated with the niche-mimicking polymer.

CONCLUSION

This study screened for biofunctional polymers suitable for recapitulation of the pancreatic CSC niche and one hydrogel with high niche-mimicking abilities was successfully fabricated. Two soluble factors with clinical significance were identified as potential candidates for biomarkers and therapeutic targets in pancreatic cancers. Such a biomaterial-based approach could be a new platform in drug discovery and therapy development against CSCs, via targeting of their niche.

Unraveling the heterogeneity of cholangiocarcinoma and identifying biomarkers and therapeutic strategies with single-cell sequencing technology

Cholangiocarcinoma (CCA) is a common malignant tumor of the biliary tract that carries a high burden of morbidity and a poor prognosis. Due to the lack of precise diagnostic methods, many patients are often diagnosed at advanced stages of the disease. The current treatment options available are of varying efficacy, underscoring the urgency for the discovery of more effective biomarkers for early diagnosis and improved treatment. Recently, single-cell sequencing (SCS) technology has gained popularity in cancer research. This technology has the ability to analyze tumor tissues at the single-cell level, thus providing insights into the genomics and epigenetics of tumor cells. It also serves as a practical approach to study the mechanisms of cancer progression and to explore therapeutic strategies. In this review, we aim to assess the heterogeneity of CCA using single-cell sequencing technology, with the ultimate goal of identifying possible biomarkers and potential treatment targets.

The roles of mutated SPINK1 gene in prostate cancer cells

SPINK1-positive prostate cancer (PCa) has been identified as an aggressive PCa subtype. However, there is a lack of definite studies to elucidate the underlying mechanism of the loss of SPINK1 expression in most PCa cells except 22Rv1 cells, which are derived from a human prostatic carcinoma xenograft, CWR22R. The aim of this study was to investigate the mechanisms of SPINK1 protein positive/negative expression and its biological roles in PCa cell lines. SPINK1 mRNA was highly expressed in 22Rv1 cells compared with LNCaP, C4-2B, DU145, and PC-3 cells, and the protein was only detected in 22Rv1 cells. Among these cell lines, the wild-type SPINK1 coding sequence was only found in 22Rv1 cells, and two mutation sites, the c.194G>A missense mutation and the c.210T>C synonymous mutation, were found in other cell lines. Our further research showed that the mutations were associated with a reduction in SPINK1 mRNA and protein levels. Functional experiments indicated that SPINK1 promoted PC-3 cell proliferation, migration, and invasion, while knockdown of SPINK1 attenuated 22Rv1 cell proliferation, migration, and invasion. The wild-type SPINK1 gene can promote the malignant behaviors of cells more than the mutated ones. Cell cycle analysis by flow cytometry showed that SPINK1 decreased the percentage of cells in the G0/G1 phase and increased the percentage of S phase cells. We demonstrated that the c.194G>A and c.210T>C mutations in the SPINK1 gene decreased the mRNA and protein levels. The wild-type SPINK1 gene is related to aggressive biological behaviors of PCa cells and may be a potential therapeutic target for PCa.

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.

Integrated bioinformatics analysis reveals potential mechanisms associated with intestinal flora intervention in nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease that imposes a huge economic burden on global public health. And the gut-liver axis theory supports the therapeutic role of intestinal flora in the development and progression of NAFLD. To this end, we designed bioinformatics study on the relationship between intestinal flora disorder and NAFLD, to explore the possible molecular mechanism of intestinal flora interfering with NAFLD.

METHODS

Differentially expressed genes for NAFLD were obtained from the GEO database. And the disease genes for NAFLD and intestinal flora disorder were obtained from the disease databases. The protein-protein interaction network was established by string 11.0 database and visualized by Cytoscape 3.7.2 software. Cytoscape plug-in MCODE and cytoHubba were used to screen the potential genes of intestinal flora disorder and NAFLD, to obtain potential targets for intestinal flora to interfere in the occurrence and process of NAFLD. Enrichment analysis of potential targets was carried out using R 4.0.2 software.

RESULTS

The results showed that 7 targets might be the key genes for intestinal flora to interfere with NAFLD. CCL2, IL6, IL1B, and FOS are mainly related to the occurrence and development mechanism of NAFLD, while PTGS2, SPINK1, and C5AR1 are mainly related to the intervention of intestinal flora in the occurrence and development of NAFLD. The gene function is mainly reflected in basic biological processes, including the regulation of metabolic process, epithelial development, and immune influence. The pathway is mainly related to signal transduction, immune regulation, and physiological metabolism. The TNF signaling pathway, AGE-RAGE signaling pathway in diabetic activity, and NF-Kappa B signaling pathways are important pathways for intestinal flora to interfere with NAFLD. According to the analysis results, there is a certain correlation between intestinal flora disorder and NAFLD.

CONCLUSION

It is speculated that the mechanism by which intestinal flora may interfere with the occurrence and development of NAFLD is mainly related to inflammatory response and insulin resistance. Nevertheless, further research is needed to explore the specific molecular mechanisms.

Structural and Biophysical Insights into SPINK1 Bound to Human Cationic Trypsin

(1) The serine protease inhibitor Kazal type 1 (SPINK1) inhibits trypsin activity in zymogen granules of pancreatic acinar cells. Several mutations in the SPINK1 gene are associated with acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP). The most common variant is SPINK1 p.N34S. Although this mutation was identified two decades ago, the mechanism of action has remained elusive. (2) SPINK1 and human cationic trypsin (TRY1) were expressed in E. coli, and inhibitory activities were determined. Crystals of SPINK1-TRY1 complexes were grown by using the hanging-drop method, and phases were solved by molecular replacement. (3) Both SPINK1 variants show similar inhibitory behavior toward TRY1. The crystal structures are almost identical, with minor differences in the mutated loop. Both complexes show an unexpected rotamer conformation of the His63 residue in TRY1, which is a member of the catalytic triad. (4) The SPINK1 p.N34S mutation does not affect the inhibitory behavior or the overall structure of the protein. Therefore, the pathophysiological mechanism of action of the p.N34S variant cannot be explained mechanistically or structurally at the protein level. The observed histidine conformation is part of a mechanism for SPINK1 that can explain the exceptional proteolytic stability of this inhibitor.

SPINKs in Tumors: Potential Therapeutic Targets

The serine protease inhibitor Kazal type (SPINK) family includes SPINK1-14 and is the largest branch in the serine protease inhibitor family. SPINKs play an important role in pancreatic physiology and disease, sperm maturation and capacitation, Nager syndrome, inflammation and the skin barrier. Evidence shows that the unregulated expression of SPINK1, 2, 4, 5, 6, 7, and 13 is closely related to human tumors. Different SPINKs exhibit various regulatory modes in different tumors and can be used as tumor prognostic markers. This article reviews the role of SPINK1, 2, 4, 5, 6, 7, and 13 in different human cancer processes and helps to identify new cancer treatment targets.

The Role of Filippi's Glands in the Silk Moths Cocoon Construction

Filippi’s glands (FGs), formerly also called Lyonet’s glands, are accessory secretory structures of the labial (silk) glands of lepidopteran caterpillars, which were implicated to play an important role in the maturation of the silk material and the construction of the cocoon. In our previous study, we have identified several species of giant silk moths that completely lack the FGs. Interestingly, the absence of FGs in these species correlates with the construction of a loose cocoon architecture. We investigated the functions of FGs by their surgical extirpation in the last instar larvae of the silkworm, Bombyx mori. We found that the absence of FGs altered the structure of the resulting cocoon, in which the different layers of silk were separated. In further experiments, we found no effects of the absence of FGs on larval cocoon formation behavior or on changes in cocoon mass or lipid content. Differential proteomic analysis revealed no significant contribution of structural proteins from FGs to silk cocoon material, but we identified several low abundance proteins that may play a role in posttranslational modifications of some silk proteins. Proteomic analysis also revealed a difference in phosphorylation of the N-terminal sequence of fibroin-heavy chain molecule. Thus, FGs appear to affect silk stickiness during spinning by regulating posttranslational modifications. This could also explain the link that exists between the absence of these glands and the formation of loose cocoons in some giant silk moth species.

TATI, TAT-2, and CRP as Prognostic Factors in Colorectal Cancer

OBJECTIVES

Colorectal cancer is the third most common cancer worldwide, with an obvious need for more accurate prognostics. Previous studies identified C-reactive protein (CRP) as a prognostic serum biomarker for colorectal cancer, whereas the biomarkers tumor-associated trypsin inhibitor (TATI) and tumor-associated trypsin-2 (TAT-2) are less well-known prognostic factors. Therefore, in this study, we aimed to compare the prognostic role of these biomarkers.

MATERIALS AND METHODS

Our cohort consisted of 219 women and 274 men who underwent colorectal cancer surgery at Helsinki University Central Hospital from 1998 through 2005. Serum and plasma samples were collected before surgery, aliquoted, stored at -80°C, and then analyzed using high-sensitivity methods with commercially available time-resolved immunofluorometric assay kits.

RESULTS

In univariate analysis, CRP (HR 1.67; 95% confidence interval [CI]: 1.25-2.23; p = 0.001), TATI (HR 1.87; 95% CI: 1.13-3.08; p = 0.014), and TAT-2 (HR 1.52; 95% CI: 1.13-2.06; p = 0.006) were significant prognostic biomarkers across the entire cohort. In subgroup analyses, TATI and TAT-2 represented significant negative prognostic factors among patients older than 66, while patients with left-sided disease, a high serum TAT-2, or a high plasma CRP experienced worse prognosis. None of the biomarkers emerged as important in the disease stage subgroup analysis nor did they serve as independent factors in the multivariate analysis.

CONCLUSIONS

TATI and TAT-2 as well as CRP significantly, but not independently, served as prognostic factors in our cohort of colorectal cancer patients. Further research is needed to fully understand their clinical role in colorectal cancer.

SPINK1 as a plasma marker for tumor hypoxia and a therapeutic target for radiosensitization

Hypoxia is associated with tumor radioresistance; therefore, a predictive marker for tumor hypoxia and a rational target to overcome it have been sought to realize personalized radiotherapy. Here, we show that serine protease inhibitor Kazal type I (SPINK1) meets these 2 criteria. SPINK1 expression was induced upon hypoxia (O2 < 0.1%) at the transcription initiation level in a HIF-dependent manner, causing an increase in secreted SPINK1 levels. SPINK1 proteins were detected both within and around hypoxic regions of xenografted and clinical tumor tissues, and their plasma levels increased in response to decreased oxygen supply to xenografts. Secreted SPINK1 proteins enhanced radioresistance of cancer cells even under normoxic conditions in EGFR-dependent and nuclear factor erythroid 2-related factor 2-dependent (Nrf2-dependent) manners and accelerated tumor growth after radiotherapy. An anti-SPINK1 neutralizing antibody exhibited a radiosensitizing effect. These results suggest that SPINK1 secreted from hypoxic cells protects the surrounding and relatively oxygenated cancer cells from radiation in a paracrine manner, justifying the use of SPINK1 as a target for radiosensitization and a plasma marker for predicting tumor hypoxia.

Enhancement of gemcitabine efficacy by K73-03 via epigenetically regulation of miR-421/SPINK1 in gemcitabine resistant pancreatic cancer cells

BACKGROUND

Gemcitabine (GCB) is a first-line chemotherapeutic drug for pancreatic cancer (PCa). However, the resistance begins developing within weeks of chemotherapy. SPINK1 overexpression enhances resistance to chemotherapy. In a recent study, our laboratory established that the oleanolic acid (OA) derivative, K73-03, had a strong inhibitory effect on a SPINK1 overexpressed PCa cells.

PURPOSE

In our current study, we studied the enhancement of GCB inhibitory effect by K73-03, a new novel OA derivative, alone or in combination with GCB on the GCB-resistant PCa cells by mitochondrial damage through regulation of the miR-421/SPINK1.

METHODS

We detected the binding between miR-421 and SPINK1-3'-UTR in GCB-resistant PCa cells using Luciferase reporter assays. Cells viability, apoptosis, migration, and mitochondrial damage were investigated.

RESULTS

The results demonstrated that the combination of K73-03 and GCB suppressed the growth of AsPC-1 and MIA PaCa-2 cells synergistically, with or without GCB resistance. Mechanistic findings showed that a combination of K73-03 and GCB silences SPINK1 epigenetically by miR-421 up-regulating, which leads to mitochondrial damage and inducing apoptosis in GCB-resistant PCa cells.

CONCLUSION

We found an interesting finding that the 73-03 in combination with GCB can improve GCB efficacy and decrease PCa resistance, which induced apoptosis and mitochondrial damage through epigenetic inhibition of SPINK1 transcription by miR-421 up-regulation. This was the first study that used OA derivatives on GCB-resistant PCa cells, so this combined strategy warrants further investigation.

Performance of SPINK1 and SPINK1-based diagnostic model in detection of hepatocellular carcinoma

OBJECTIVES

To identify the SPINK1 or SPINK1-based model as a more reliable biomarker for the diagnosis of hepatocellular carcinoma (HCC).

METHODS

Serum samples and related laboratory parameters were collected from 540 subjects (119 healthy donors, 113 patients with chronic hepatitis B, 122 patients with liver cirrhosis, and 186 patients with HCC). SPINK1 was determined by ELISA assay. Differences in each variable were compared by one-way ANOVA or Kruskal-Wallis test. ROC (receiver operating characteristic) curve analysis was conducted to compare the diagnostic efficiency of alpha-fetoprotein (AFP), SPINK1, and a SPINK1-based combine model constructed by binary Logistic regression.

RESULTS

In detecting HCC using the other three groups as control, ROC curve analysis revealed that SPINK1 alone reached AUC of 0.899 (0.866-0.933), with the sensitivity of 0.812 of and specificity of 0.953. The combined model increased the AUC to 0.945 (0.926-0.964) with the sensitivity and specificity of 0.860 and 0.910, respectively. For AFP, significantly lower AUC (p < 0.0001) was shown, which was 0.695 (0.645-0.745) with the sensitivity and specificity of 0.634 and 0.718, respectively. In discriminating HCC from liver disease control, AUC of SPINK1 was 0.863(0.826-0.894), the sensitivity and specificity were 0.823 and 0.906, respectively. For combined model, the AUC, sensitivity, and specificity were 0.915 (0.884-0.940), 0.863, and 0.916, respectively. For detecting early-stage HCC, SPINK1 and combined model achieved the sensitivity of 0.788 and 0.818, respectively, much higher than AFP of 0.485 (p < 0.05); however, the difference between SPINK1 and combined model was not statistically significant (p = 1).

CONCLUSION

We provided solid evidence for SPINK1 as a robust serological tool for HCC diagnosis.

High SPINK4 Expression Predicts Poor Outcomes among Rectal Cancer Patients Receiving CCRT

BACKGROUND

Patients with rectal cancer can prospectively be favored for neoadjuvant concurrent chemoradiotherapy (CCRT) to downstage before a radical proctectomy, but the risk stratification and clinical outcomes remain disappointing.

METHODS

From a published rectal cancer transcriptome dataset (GSE35452), we highlighted extracellular matrix (ECM)-linked genes and identified the serine protease inhibitor Kazal-type 4 (SPINK4) gene as the most relevant among the top 10 differentially expressed genes associated with CCRT resistance. We accumulated the cases of 172 rectal cancer patients who received neoadjuvant CCRT followed by surgery and collected tumor specimens for the evaluation of the expression of SPINK4 using immunohistochemistry.

RESULTS

The results revealed that high SPINK4 immunoexpression was significantly related to advanced pre-CCRT and post-CCRT tumor status (both p < 0.001), post-CCRT lymph node metastasis (p = 0.001), more vascular and perineurial invasion (p = 0.015 and p = 0.023), and a lower degree of tumor regression (p = 0.001). In univariate analyses, high SPINK4 immunoexpression was remarkably correlated with worse disease-specific survival (DSS) (p < 0.0001), local recurrence-free survival (LRFS) (p = 0.0017), and metastasis-free survival (MeFS) (p < 0.0001). Furthermore, in multivariate analyses, high SPINK4 immunoexpression remained independently prognostic of inferior DSS and MeFS (p = 0.004 and p = 0.002).

CONCLUSION

These results imply that high SPINK4 expression is associated with advanced clinicopathological features and a poor therapeutic response among rectal cancer patients undergoing CCRT, thus validating the prospective prognostic value of SPINK4 for those patients.

A 3D system to model human pancreas development and its reference single-cell transcriptome atlas identify signaling pathways required for progenitor expansion

Human organogenesis remains relatively unexplored for ethical and practical reasons. Here, we report the establishment of a single-cell transcriptome atlas of the human fetal pancreas between 7 and 10 post-conceptional weeks of development. To interrogate cell–cell interactions, we describe InterCom, an R-Package we developed for identifying receptor–ligand pairs and their downstream effects. We further report the establishment of a human pancreas culture system starting from fetal tissue or human pluripotent stem cells, enabling the long-term maintenance of pancreas progenitors in a minimal, defined medium in three-dimensions. Benchmarking the cells produced in 2-dimensions and those expanded in 3-dimensions to fetal tissue identifies that progenitors expanded in 3-dimensions are transcriptionally closer to the fetal pancreas. We further demonstrate the potential of this system as a screening platform and identify the importance of the EGF and FGF pathways controlling human pancreas progenitor expansion.

From single-cell transcriptome analyses to defining culture media for spheroids, the authors provide a census of information to understand the development of human pancreatic progenitors. This approach identifies signalling pathways (EGF and FGF) regulating progenitor proliferation.

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.

miR-421 up-regulation by the oleanolic acid derivative K73-03 regulates epigenetically SPINK1 transcription in pancreatic cancer cells leading to metabolic changes and enhanced apoptosis

SPINK1 overexpression promotes cancer cell aggressiveness and confers chemo-resistance to multiple drugs in pancreatic cancer. Oleanolic acid (OA) derivatives possess active effects against different cancers. Here we report the effect of K73-03, a new novel OA derivative, against pancreatic cancer through mitochondrial dysfunction via miR-421/SPINK1 regulation. We examined the binding ability of miR-421 with SPINK1-3'UTR Luciferase reporter assays. Moreover, miR-421/SPINK1 expressions in pancreatic cancer, with or without K73-03 treatment, were evaluated. Cells viability, migration, autophagy, mitochondrial function and apoptosis were examined with or without K73-03 treatment. We established that the K73-03 effect on the miR-421 that plays a crucial role in the regulation of SPINK1 in pancreatic cancer. Our findings indicated that K73-03 inhibited the mitochondrial function that led to inducing autophagy and apoptosis through epigenetic SPINK1 down-regulation via miR-421 up-regulation in pancreatic cancer. Furthermore, the inhibition of miR-421 expression in pancreatic cancer cells abolished the efficacy of K73-03 against SPINK1 oncogenic properties. We found an interesting finding that the interaction between miR-421 and SPINK1 is related to mitochondrial function through the effect of K73-03. Further, SPINK1 appear to be the molecular targets of K73-03 especially more than gemcitabine.

Tumor-associated trypsin inhibitor (TATI) and tumor-associated trypsin-2 (TAT-2) predict outcomes in gastric cancer

Introduction: Tumor-associated trypsin inhibitor (TATI) limits serine proteases, promotes carcinogenesis in several cancers and functions as an acute-phase reactant. Tumor-associated trypsin-2 (TAT-2), a proteolytic target enzyme for TATI, can enhance invasion by promoting extracellular matrix degradation. Here, we aimed to study serum TATI and TAT-2 levels, including the TAT-2/TATI ratio, as prognostic and diagnostic biomarkers in gastric cancer. We compared the results with the plasma level of C-reactive protein (CRP).Material and Methods: We selected 240 individuals operated on for gastric adenocarcinoma at the Helsinki University Hospital, Finland, between 2000 and 2009. We determined the preoperative serum TAT-2, TATI and plasma CRP levels using time-resolved immunofluorometric assays using monoclonal antibodies.Results: The medium serum TAT-2 level was higher among gastric cancer patients [8.68 ng/ml; interquartile range (IQR) 5.93-13.2] than among benign controls (median 5.41 ng/ml; IQR 4.12-11.8; p = .005). Five-year survival among patients with a high serum TAT-2 was 22.9% [95% confidence interval (CI) 11.7-34.1], compared to 52.2% (95% CI 44.6-59.8; p < .001) among those with a low level. The five-year survival among patients with a high serum TATI was 30.6% (95% CI 20.4-40.8), compared to 52.9% (95% CI 44.7-61.1; p < .001) among those with a low level. The serum TATI level remained significant in the multivariable survival analysis (hazard ratio 2.01; 95% CI 1.32-3.07). An elevated plasma CRP level associated with a high serum TATI level (p = .037).Conclusions: This study shows for the first time that a high serum TAT-2 may function as a prognostic biomarker in gastric cancer and that TAT-2 levels may be elevated compared to controls. Additionally, we show that the prognosis is worse among gastric cancer patients with a high serum TATI. These biomarkers serve as prognostic factors particularly among patients with a metastatic or a locally advanced disease.

Roles of Autophagy and Pancreatic Secretory Trypsin Inhibitor in Trypsinogen Activation in Acute Pancreatitis

The focus of the review is on roles of autophagy and pancreatic secretory trypsin inhibitor (PSTI), an endogenous trypsin inhibitor, in trypsinogen activation in acute pancreatitis. Acute pancreatitis is a disease in which tissues in and around the pancreas are autodigested by pancreatic digestive enzymes. This reaction is triggered by the intrapancreatic activation of trypsinogen. Autophagy causes trypsinogen and cathepsin B, a trypsinogen activator, to colocalize within the autolysosomes. Consequently, if the resultant trypsin activity exceeds the inhibitory activity of PSTI, the pancreatic digestive enzymes are activated, and they cause autodigestion of the acinar cells. Thus, autophagy and PSTI play important roles in the development and suppression of acute pancreatitis, respectively.

Identification of Novel Biomarkers in Pancreatic Tumor Tissue to Predict Response to Neoadjuvant Chemotherapy

Background: Neoadjuvant chemotherapy (NAC) has been of recent interest as an alternative to upfront surgery followed by adjuvant chemotherapy in patients with pancreatic ductal adenocarcinoma (PDAC). However, a subset of patients does not respond to NAC and may have been better managed by upfront surgery. Hence, there is an unmet need for accurate biomarkers for predicting NAC response in PDAC. We aimed to identify upregulated proteins in tumor tissue from poor- and good-NAC responders.

Methods: Tumor and adjacent pancreas tissue samples were obtained following surgical resection from NAC-treated PDAC patients. SWATH-MS proteomic analysis was performed to identify and quantify proteins in tissue samples. Statistical analysis was performed to identify biomarkers for NAC response. Pathway analysis was performed to characterize affected canonical pathways in good- and poor-NAC responders.

Results: A total of 3,156 proteins were identified, with 19 being were significantly upregulated in poor-responders compared to good-responders (log₂ ratio > 2, p < 0.05). Those with the greatest ability to predict poor-NAC response were GRP78, CADM1, PGES2, and RUXF. Notably, canonical pathways that were significantly upregulated in good-responders included acute phase signaling and macrophage activation, indicating a heightened immune response in these patients.

Conclusion: A novel biomarker signature for poor-NAC response in PDAC was identified.

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.

Downregulated SPINK4 is associated with poor survival in colorectal cancer

BACKGROUND

SPINK4 is known as a gastrointestinal peptide in the gastrointestinal tract and is abundantly expressed in human goblet cells. The clinical significance of SPINK4 in colorectal cancer (CRC) is largely unknown.

METHODS

We retrieved the expression data of 1168 CRC patients from 3 Gene Expression Omnibus (GEO) datasets (GSE24551, GSE39582, GSE32323) and The Cancer Genome Atlas (TCGA) to compare the expression level of SPINK4 between CRC tissues and normal colorectal tissues and to evaluate its value in predicting the survival of CRC patients. At the protein level, these results were further confirmed by data mining in the Human Protein Atlas and by immunohistochemical staining of samples from 81 CRC cases in our own center.

RESULTS

SPINK4 expression was downregulated in CRC compared with that in normal tissues, and decreased SPINK4 expression at both the mRNA and protein levels was associated with poor prognosis in CRC patients from all 3 GEO datasets, the TCGA database and our cohort. Additionally, lower SPINK4 expression was significantly related to higher TNM stage. Moreover, in multivariate regression, SPINK4 was confirmed as an independent indicator of poor survival in CRC patients in all databases and in our own cohort.

CONCLUSIONS

We concluded that reduced expression of SPINK4 relates to poor survival in CRC, functioning as a novel indicator.

Tazarotene-Induced Gene 1 (TIG1) Interacts with Serine Protease Inhibitor Kazal-Type 2 (SPINK2) to Inhibit Cellular Invasion of Testicular Carcinoma Cells

Tazarotene-induced gene 1 (TIG1) encodes a protein that is a retinoid-regulated tumor suppressor. TIG1 is expressed in most normal tissues, and downregulation of TIG1 expression in multiple cancers is caused by promoter hypermethylation. Kazal-type serine protease inhibitor-2 (SPINK2) is a serine protease inhibitor, and the SPINK protein family has been shown to inhibit the expression of urokinase-type plasminogen activator (uPA). In addition, increased levels of uPA and the uPA receptor were observed in testicular cancer tissues. This study demonstrated that TIG1 interacts with SPINK2 in NT2/D1 testicular carcinoma cells. TIG1 and SPINK2 were highly expressed in normal testis tissues, while low expression levels of TIG1 and SPINK2 were found in testicular cancer tissues. TIG1 inhibited cell invasion, migration, and epithelial-mesenchymal transition (EMT) of NT2/D1 cells. SPINK2 enhanced TIG1-regulated uPA activity and EMT suppression, while silencing SPINK2 alleviated TIG1-mediated EMT regulation, cell migration, and invasion. Therefore, the results suggest that the interaction between TIG1 and SPINK2 plays an important role in the inhibition of testicular cancer cell EMT, and suppression is mediated through downregulation of the uPA/uPAR signaling pathway.

SPINK1 is a prognosis predicting factor of non-small cell lung cancer and regulates redox homeostasis

Serine protease inhibitor Kazal-type 1 (SPINK1) is a trypsin kinase inhibitor, which is involved in the development of inflammation, cell proliferation and cancer development and progression. However, the prognostic value of SPINK1 in non-small cell lung cancer (NSCLC) and its ability to regulate intrinsic redox homeostasis have, to the best of our knowledge, not been previously investigated. In the present study, it was revealed that SPINK1 is highly expressed in NSCLC tissue samples compared with normal tissue samples, and may be a potential prognostic marker of NSCLC. Functional analyses demonstrated that SPINK1 promoted tumor cell growth and inhibited apoptosis through maintaining redox homeostasis by regulating the nuclear factor erythroid 2-related factor 2 pathways. It has been proposed that SPINK1 could be a prognostic marker of NSCLC and a novel antioxidant promoter under oxidative stress conditions in NSCLC.

SPINK1 promotes cell growth and metastasis of lung adenocarcinoma and acts as a novel prognostic biomarker

Serine protease inhibitor Kazal type 1 (SPINK1) plays a role in protecting the pancreas against premature activation of trypsinogen and is involved in cancer progression. SPINK1 promoted LAC cells growth, migration, and invasion. Mechanistically, we found that SPINK1 promoted LAC cells migration and invasion via up-regulating matrix metalloproteinase 12 (MMP12). We observed that SPINK1 expression was only up-regulated in lung adenocarcinoma (LAC) tissues, and was an independent prognostic factor for poor survival. Our results indicate that SPINK1 might be a potential biomarker for LAC that promotes progression by MMP12. [BMB Reports 2018; 51(12): 648-653].

Surgical decompression of Wirsung duct reduces serum concentration of SPINK1 in patients with chronic pancreatitis

OBJECTIVES

The primary aim of this study was to determine the blood levels of SPINK1 in patients with chronic pancreatitis (CP) submitted to surgical or endoscopic decompression of pancreatic duct (PD). Additionally, we measured trypsin activity levels.

METHODS

Two groups were identified, surgical (group A) and endoscopic (group B). Levels of SPINK1 and trypsin activity were measured at baseline and 6 months after pancreatic duct decompression and then compared within the groups. SPINK1 levels were determined with Human ELISA Kit.

RESULTS

Group A and B were made up of 30 and 28 patients, respectively. Baseline features of the groups were similar. A decrease in SPINK1 levels was significant only in group A 46.88 to 16.10 ng/mL (p = 0.001). On the contrary, trypsin activity changed significantly in group B 40.01 to 34.92 mU/mL (p = 0.01). Patients of group A showed a significant increase in BMI, before and after treatment. The pain score pre- and post-treatment reduced significantly in both groups (p < 0.001).

CONCLUSIONS

We demonstrate for the first time a significant decrease of SPINK1 levels after surgical decompression of PD and a reduction of trypsin activity analysis after endoscopic decompression. The meaning of this phenomena is yet to be explained and it should be further explored.

Serine peptidase inhibitor Kazal type I (SPINK1) promotes BRL-3A cell proliferation via p38, ERK, and JNK pathways

Serine peptidase inhibitor Kazal type I (SPINK1) has the similar spatial structure as epidermal growth factor (EGF); EGF can interact with epidermal growth factor receptor (EGFR) to promote proliferation in different cell types. However, whether SPINK1 can interact with EGFR and further regulate the proliferation of hepatocytes in liver regeneration remains largely unknown. In this study, we investigated the role of SPINK1 in a rat liver hepatocyte line of BRL-3A in vitro. The results showed the upregulation of endogenous Spink1 (gene addition) significantly increased not only the cell viability, cell numbers in S and G₂ /M phase, but also upregulated the genes/proteins expression related to cell proliferation and anti-apoptosis in BRL-3A. In contrast, the cell number in G₁ phase and the expression of pro-apoptosis-related genes/proteins were significantly decreased. The similar results were observed when the cells were treated with exogenous rat recombinant SPINK1. Immunoblotting suggested SPINK1 can interact with EGFR. By Ingenuity Pathway Analysis software, the SPINK1 signalling pathway was built; the predicted read outs were validated by qRT-PCR and western blot; and the results showed that p38, ERK, and JNK pathways-related genes/proteins were involved in the cell proliferation upon the treatment of endogenous Spink1 and exogenous SPINK1. Collectively, SPINK1 can associate with EGFR to promote the expression of cell proliferation-related and anti-apoptosis-related genes/proteins; inhibit the expression of pro-apoptosis-related genes/proteins via p38, ERK, and JNK pathways; and consequently promote the proliferation of BRL-3A cells. For the first time, we demonstrated that SPINK1 can associate with EGFR to promote the proliferation of BRL-3A cells via p38, ERK, and JNK pathways. This work has direct implications on the underlying mechanism of SPINK1 in regulating hepatocytes proliferation in vivo and liver regeneration after partial hepatectomy.

Serine peptidase inhibitor Kazal type 1 (SPINK1) as novel downstream effector of the cadherin-17/β-catenin axis in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common type of liver cancer worldwide. Previously, we reported that cadherin-17 (CDH17) and its related CDH17/β-catenin axis may be responsible for inducing HCC in a subset of patients exhibiting CDH17 over-expression. Here we aimed at obtaining a better understanding of the CDH17-related HCC biology and to obtain further indications for the design of targeted therapies in CDH17 over-expressing HCC patients.

RESULTS

We found that SPINK1 acts as a downstream effector of the CDH17/β-catenin axis in HCC. In addition, we found that SPINK1 expression exhibited a positive correlation with CDH17 expression in human HCCs and was over-expressed in up to 70% of the tumors. We identified SPINK1 as a downstream effector of the CDH17/β-catenin axis using a spectrum of in vitro assays, including gene expression modulation and inhibitor assays, bioinformatics analyses and luciferase reporter assays. These in vitro results were validated in primary human HCCs, including the observation that alteration in β-catenin expression (a core component of the CDH17/β-catenin axis) in tumors affects SPINK1 serum levels in HCC patients. Similar to CDH17, SPINK1 expression in HCC cells was found to be associated with specific tumor-related properties via activating the c-Raf/MEK/ERK pathway.

CONCLUSIONS

Our current data substantiate our knowledge on the role of CDH17 in the biology of HCC and suggest that components of the CDH17/β-catenin axis may serve as therapeutic targets in CDH17 over-expressing HCC patients.

Serine protease inhibitor Kazal type 1 (SPINK1) downregulates E-cadherin and induces EMT of hepatoma cells to promote hepatocellular carcinoma metastasis via the MEK/ERK signaling pathway

OBJECTIVE

To investigate serine protease inhibitor Kazal type 1 (SPINK1) expression and its influence on the prognosis of human hepatocellular carcinoma (HCC) and to explore the underlying molecular mechanisms involved.

METHODS

Altogether 80 patients with HCC who underwent curative resection were followed up for a median of 58.6 months. SPINK1 expression was detected in the primary HCC samples by immunohistochemistry. Its role in tumor invasion and metastasis was evaluated in vitro by gene silencing using a small interfering RNA-mediated approach, recombinant SPINK1 and U0126 (an inhibitor of MEK/ERK). The proteins in the MEK/ERK signaling pathway were detected by Western blot.

RESULTS

Patients with high SPINK1 expression showed poor overall survival (P = 0.0001) and recurrence-free survival (P = 0.001) compared with those with low SPINK1 expression. The suppression of SPINK1 resulted in reduced cell migration and invasion. SPINK1 overexpression was significantly associated with increased cell migration and invasion in vitro. Furthermore, SPINK1 promoted cancer cells motility and epithelial-mesenchymal transition (EMT) via the mitogen-activated protein kinase kinase (MAPK) and extracellular regulated kinase (ERK) pathway, resulting in increased vimentin expression and decreased E-cadherin expression.

CONCLUSION

SPINK1 may be an oncogene that induces EMT via the MEK/ERK pathway and is a potential target for HCC therapy.

New and Emerging Diagnostic and Prognostic Immunohistochemical Biomarkers in Prostate Pathology

The diagnosis of minimal prostatic adenocarcinoma can be challenging on prostate needle biopsy, and immunohistochemistry may be used to support the diagnosis of cancer. The International Society of Urologic Pathology currently recommends the use of the basal cell markers high-molecular-weight cytokeraratin and p63, and α-methylacyl-coenzyme-A racemase. However, there are caveats associated with the interpretation of these markers, particularly with benign mimickers. Another issue is that of early detection of presence and progression of disease and prediction of recurrence after clinical intervention. There remains a lack of reliable biomarkers to accurately predict low-risk cancer and avoid over treatment. As such, aggressive forms of prostate cancer may be missed and indolent disease may be subjected to unnecessary radical therapy. New biomarker discovery promises to improve early detection and prognosis and to provide targets for therapeutic interventions. In this review, we present the emerging immunohistochemical biomarkers of prostate cancer PTEN, ERG, FASN, MAGI-2, and SPINK1, and address their diagnostic and prognostic advantages and limitations.

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.

Serine protease inhibitor Kazal type 1 and epidermal growth factor receptor are expressed in pancreatic tubular adenocarcinoma, intraductal papillary mucinous neoplasm, and pancreatic intraepithelial neoplasia

BACKGROUND

Serine protease inhibitor Kazal type 1 (SPINK1) is expressed in normal human pancreatic acinar cells and in a variety of tumors, and binds to the epidermal growth factor receptor (EGFR), mediating cell proliferation through the mitogen-activated protein kinase cascade in pancreatic cancer cell lines. Here, we aimed to assess SPINK1 and EGFR expression in various neoplastic lesions, including tissues demonstrating precancerous changes.

METHODS

Surgical specimens of pancreatic ductal adenocarcinoma (n = 23), intraductal papillary mucinous neoplasm (IPMN;n = 21), pancreatic neoplasms other than ductal adenocarcinoma (n = 8), chronic pancreatitis (n = 11), and pancreatic intraepithelial neoplasia (PanIN) lesions within the resected specimens were analyzed immunohistochemically for SPINK1 and EGFR expression.

RESULTS

Sixty-five PanIN-1A, 32 PanIN-1B, 17 PanIN-2, and 6 PanIN-3 were identified. Both SPINK1 and EGFR were expressed in almost all PanIN lesions. All tubular ductal adenocarcinoma, IPMN, and mucinous cystadenocarcinoma samples (neoplasms of ductal origin) expressed SPINK1, whereas acinar cell carcinoma, anaplastic carcinoma, adenosquamous carcinoma, insulinoma, and islet cell carcinoma did not. EGFR was expressed in 87 % of tubular adenocarcinoma and 48 % of IPMN lesions. Among IPMN lesions, malignant lesions (IPMC) expressed EGFR more often than benign lesions (IPMA) did. Scattered expression of EGFR was observed in normal pancreatic ducts and within the tubular complex within chronic pancreatitis lesions.

CONCLUSIONS

These results indicate that SPINK1 plays a role as a growth factor, signaling through the EGFR pathway in pancreatic ductal adenocarcinoma and neoplasms, and that the EGFR is involved in the malignant transformation of IPMN.

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.

The construction and proliferative effects of a lentiviral vector capable of stably overexpressing SPINK1 gene in human pancreatic cancer AsPC-1 cell line

This study aims to design and generate recombinant lentiviral vector containing the complete coding sequence (CDS) region of human serine protease inhibitor Kazal type 1 gene (SPINK1) and establish a human pancreatic cancer cell line (AsPC-1) stably overexpressing SPINK1. Then, to assess the proliferative and oncogenic effects of upregulated SPINK1 gene on pancreatic cancer AsPC-1 cells using different methods. Initially, the target coding sequence (CDS) of SPINK1 was amplified by polymerase chain reaction (PCR) and the synthesized product was subsequently subcloned into the lentiviral vector. The construction of recombinant SPINK1 gene was verified by the restriction digestion and sequencing analysis. The lentiviral particles carrying SPINK1 gene were produced by co-transfection of the recombination lentiviral vector and the packaging mix plasmids into 293 T cells and filtered and concentrated before AsPC-1 cells were infected by the virus particles. The cells transduced were differentially selected with puromycin, and the clones that highly expressed SPINK1 were chosen by real-time PCR and confirmed by Western blot after 7 weeks. The stably transduced AsPC-1 cell line showed significantly increased metabolic and proliferative capability using CCK-8 and Trypan Blue assays (P < 0.001). Cell cycle and DNA content analysis by flow cytometry showed that upregulated SPINK1 elicited significant increase in the percentage of AsPC-1 cells in the S and G2/M phase (P < 0.001). Clone formation assay demonstrated that the number of the colonies formed in the experimental group was greater than that in the control parental cells (P < 0.001). It was concluded that a stable AsPC-1 cell line capable of overexpressing SPINK1 had been successfully created, and that the proliferative capacity of AsPC-1 pancreatic cancer cells was significantly raised by SPINK1 upregulation as well as the ability of a single AsPC-1 cell to grow into a colony.

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.

Clinical value of ERG, TFF3, and SPINK1 for molecular subtyping of prostate cancer

BACKGROUND

In view of the marked molecular heterogeneity of prostate cancer (PCa), clinical and pathologic parameters alone may be unreliable for predicting disease outcomes after surgical intervention. The development of biomarkers may be helpful to estimate tumor heterogeneity and stratify patients in terms of their risk of progression. Levels of v-ets avian erythroblastosis virus E26 oncogene homolog (ERG), trefoil factor 3 (TFF3), and serine peptidase inhibitor, Kazal type 1 (SPINK1) are commonly elevated in PCa, but it is unclear whether the evaluation of these 3 markers can help to discriminate patients who will have different clinical outcomes. The authors investigated whether assessment of ERG, TFF3, and SPINK1 expression could help to define clinically relevant, distinct subsets of patients with PCa.

METHODS

The cohort consisted of 279 men with PCa who underwent radical prostatectomy at Henri Mondor Hospital. Expression levels of ERG, TFF3, and SPINK1 were evaluated immunohistochemically in the prostatectomy specimens. Potential associations of ERG, TFF3, and SPINK1 with age, prostate-specific antigen (PSA), tumor stage, Gleason score, and biochemical recurrence, defined by PSA failure, were investigated.

RESULTS

Although prognostic significance was not observed for ERG or TFF3, an exclusive pattern of expression was demonstrated for TFF3 and ERG. SPINK1 expression was observed exclusively in a subgroup of cancers that expressed TFF3 (41 of 175 tumors). Moreover, SPINK1 positivity was identified as predictive of biochemical recurrence in univariate (P = .0009) and multivariate (P = .0003) analyses.

CONCLUSIONS

The current results suggest that ERG and TFF3 characterize 2 distinct subsets of PCa, with a more aggressive subgroup of TFF3-expressing tumors that express SPINK1. Together, these findings support a rationale of screening for these biomarkers for prognostic purposes and molecular subtyping of the disease.

Generation and analysis of serine protease inhibitor kazal type 3-cre driver mice

Serine protease inhibitor Kazal type 1 (SPINK1; mouse homologue Spink3) was initially discovered as a trypsin-specific inhibitor in the pancreas. However, previous studies have suggested that SPINK1/Spink3 is expressed in a wide range of normal tissues and tumors, although precise characterization of its gene expression has not been described in adulthood. To further analyze Spink3 expression, we generated two mouse lines in which either lacZ or Cre recombinase genes were inserted into the Spink3 locus by Cre-loxP technology. In Spink3(lacZ) mice, β-galactosidase activity was found in acinar cells of the pancreas and kidney, as well as epithelial cells of the bronchus in the lung, but not in the gastrointestinal tract or liver. Spink3(cre) knock-in mice were crossed with Rosa26 reporter (R26R) mice to monitor Spink3 promoter activity. In Spink3(cre);R26R mice, β-galactosidase activity was found in acinar cells of the pancreas, kidney, lung, and a small proportion of cells in the gastrointestinal tract and liver. These data suggest that Spink3 is widely expressed in endoderm-derived tissues, and that Spink3(cre) knock-in mice are a useful tool for establishment of a conditional knockout mice to analyze Spink3 function not only in normal tissues, but also in tumors that express SPINK1/Spink3.

CBX7 modulates the expression of genes critical for cancer progression

Background

We have previously shown that the expression of CBX7 is drastically decreased in several human carcinomas and that its expression progressively decreases with the appearance of a highly malignant phenotype. The aim of our study has been to investigate the mechanism by which the loss of CBX7 expression may contribute to the emergence of a more malignant phenotype.

Methods

We analyzed the gene expression profile of a thyroid carcinoma cell line after the restoration of CBX7 and, then, analyzed the transcriptional regulation of identified genes. Finally, we evaluated the expression of CBX7 and regulated genes in a panel of thyroid and lung carcinomas.

Results

We found that CBX7 negatively or positively regulates the expression of several genes (such as SPP1, SPINK1, STEAP1, and FOS, FOSB, EGR1, respectively) associated to cancer progression, by interacting with their promoter regions and modulating their transcriptional activity. Quantitative RT-PCR analyses in human thyroid and lung carcinoma tissues revealed a negative correlation between CBX7 and its down-regulated genes, while a positive correlation was observed with up-regulated genes.

Conclusion

In conclusion, the loss of CBX7 expression might play a critical role in advanced stages of carcinogenesis by deregulating the expression of specific effector genes.

Serine protease inhibitor Kazal type 1 promotes epithelial-mesenchymal transition through EGFR signaling pathway in prostate cancer

BACKGROUND

Overexpression of serine protease inhibitor Kazal type 1 (SPINK1) defines an aggressive molecular subtype of ETS fusion-negative prostate cancer (PCa) patients in western countries. However, how SPINK1 contributes to PCa invasion and metastasis is largely unknown.

METHODS

Fluorescence in situ hybridization and immunohistochemistry were utilized to detect ERG rearrangement, SPINK1 expression, and EGFR aberrations in a cohort of 211 PCa patients with radical prostatectomy. Real-time quantitative PCR and Western blotting were used to study the transcript and protein expression levels. Cellular distribution of E-cadherin and vimentin were observed by immunofluorescence. Cellular function was evaluated by siRNA, transwell, and wound healing assay, respectively.

RESULTS

SPINK1-induced Epithelial-mesenchymal transition (EMT) in benign prostate RWPE cells, manifested by acquisition of mesenchymal morphology, alternation of EMT markers as well as migration and invasion capabilities. Knockdown of SPINK1 in 22RV1 PCa cells results in up-regulation of E-cadherin and down-regulation of vimentin. SPINK1-induced EMT is mediated by EGFR, in which MAPK/MEK/ERK pathway is mainly involved. Connective tissue growth factor (CTGF) might be an important down-stream molecule of SPINK1-EGFR axis. Clinically, SPINK1 and EGFR were significantly co-overexpressed in a cohort of Chinese PCa patients (n > 200). SPINK1 is an unfavorable prognostic factor in Chinese PCas (P = 0.025).

CONCLUSIONS

These findings suggest that SPINK1 promotes EMT through EGFR signaling pathway in PCa and SPINK1 could be a new prognostic marker in Chinese PCas.

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.