Expression of peritumoral SPARC during distal cholangiocarcinoma progression and correlation with outcome.

Objectives: Distal cholangiocarcinoma (dCCA) is a malignancy with a dismal prognosis. One of the hallmarks is the presence of a rich desmoplastic stroma believed to contribute to tumor progression and treatment resistance. Secreted protein acidic and rich in cysteine (SPARC) is a matricellular glycoprotein implicated in tumor-stroma interaction with prognostic correlation across several malignancies. The aim of the present study was to evaluate the expression pattern and prognostic significance of SPARC in resected dCCA and paired lymph node metastasis.Materials and methods: SPARC expression was evaluated in 59 resected dCCA samples and 25 paired lymph node metastases as well as 10 benign bile duct samples using immunohistochemistry. Stromal SPARC expression was scored semi quantitatively. Survival was estimated using the Kaplan-Meier method with associated log-rank test.Results: SPARC expression was absent in normal bile ducts. In dCCA, peritumoral stromal SPARC was detectable in 47/59 (80%) of samples with 40/59 (68%) classified as high stromal SPARC expression. There was a significantly lower proportion of SPARC positive stroma in paired lymph node metastasis 17/25 (68%) than the corresponding primary tumors 24/25 (96%) (p = .016). Stromal SPARC expression was associated with the presence of lymph node metastasis; high SPARC expression 31/40 (78%) versus low SPARC expression 9/19 (47%) (p = .013). In the present material there was no significant association between stromal SPARC expression and survival.Conclusions: Stromal SPARC expression occurs frequently in dCCA. Although significantly lower than in primary tumors stromal SPARC is frequently retained in paired lymph node metastasis suggesting a possible role in the metastatic process of dCCA.

YAP1 is an independent prognostic marker in pancreatic cancer and associated with extracellular matrix remodeling.

BACKGROUND: Pancreatic cancer is a major cause of cancer-related mortality. The identification of effective biomarkers is essential in order to improve management of the disease. Yes-associated protein 1 (YAP1) is a downstream effector of the Hippo pathway, a signal transduction system implicated in tissue repair and regeneration, as well as tumorigenesis. Here we evaluate the biomarker potential of YAP1 in pancreatic cancer tissue. METHODS: YAP1 was selected as a possible biomarker for pancreatic cancer from global protein sequencing of fresh frozen pancreatic cancer tissue samples and normal pancreas controls. The prognostic utility of YAP1 was evaluated using mRNA expression data from 176 pancreatic cancer patients in The Cancer Genome Atlas (TCGA), as well as protein expression data from immunohistochemistry analysis of a local tissue microarray (TMA) cohort comprising 140 pancreatic cancer patients. Ingenuity Pathway Analysis was applied to outline the interaction network for YAP1 in connection to the pancreatic tumor microenvironment. The expression of YAP1 target gene products was evaluated after treatment of the pancreatic cancer cell line Panc-1 with three substances interrupting YAP-TEAD interaction, including Super-TDU, Verteporfin and CA3. RESULTS: Mass spectrometry based proteomics showed that YAP1 is the top upregulated protein in pancreatic cancer tissue when compared to normal controls (log2 fold change 6.4; p = 5E-06). Prognostic analysis of YAP1 demonstrated a significant correlation between mRNA expression level data and reduced overall survival (p = 0.001). In addition, TMA and immunohistochemistry analysis suggested that YAP1 protein expression is an independent predictor of poor overall survival [hazard ratio (HR) 1.870, 95% confidence interval (CI) 1.224-2.855, p = 0.004], as well as reduced disease-free survival (HR 1.950, 95% CI 1.299-2.927, p = 0.001). Bioinformatic analyses coupled with in vitro assays indicated that YAP1 is involved in the transcriptional control of target genes, associated with extracellular matrix remodeling, which could be modified by selected substances disrupting the YAP1-TEAD interaction. CONCLUSIONS: Our findings indicate that YAP1 is an important prognostic biomarker for pancreatic cancer and may play a regulatory role in the remodeling of the extracellular matrix.

Expression of fibroblast activation protein and the clinicopathological relevance in distal cholangiocarcinoma.

Objectives: The current survival of patients with distal cholangiocarcinoma (dCCA) is poor. There is a need to develop new prognostic and predictive biomarkers to improve the survival of patients. Fibroblast activation protein (FAP) expression has been associated with survival in several solid malignancies. The goal of this study was to evaluate the expression pattern and prognostic significance of FAP in dCCA.Materials and methods: FAP expression was examined in 57 resected dCCA specimens and 28 paired lymph node metastasis specimens, as well as 10 benign bile ducts using immunohistochemistry. FAP expression was scored in the epithelial and stromal component of the dCCA specimens. The association between FAP expression and prognosis was evaluated using univariable and multivariable statistical modeling.Results: FAP expression was absent in the benign controls. FAP expression was evident in the epithelial 43 (75%) and stromal compartment 34 (60%) of dCCA. There was no association between epithelial or stromal FAP expression and clinicopathological factors. Epithelial FAP expression (HR 0.4 95% CI 0.20-0.78; p=.007) but not stromal FAP expression was significantly associated with better survival in univariable and multivariable analysis.Conclusions: FAP overexpression is evident in dCCA. There was a positive association between epithelial FAP expression and better survival which merits further evaluation.

Low P4HA2 and high PRTN3 expression predicts poor survival in patients with pancreatic cancer.

BACKGROUND: The tumor microenvironment in pancreatic cancer has a multifaceted role in disease development and progression. Prolyl 4-hydroxylase subunit alpha 2 (P4HA2) and proteinase 3 (PRTN3) are involved in the synthesis and degradation of collagen in the tumor microenvironment and have been identified as prognostic biomarker candidates for pancreatic cancer in our previous mass spectrometric study. This study aimed at validating prognostic performance of P4HA2 and PRTN3 in a larger cohort of patients. METHODS: The expression of P4HA2 and PRTN3 was evaluated with tissue microarrays and immunohistochemistry in 140 patients with pancreatic cancer who underwent surgical resection. Kaplan-Meier and Cox proportional hazards regression modeling were used to explore the association of P4HA2 and PRTN3, either separately or combined, with clinicopathological factors and survival. RESULTS: Most tumors were positive for P4HA2 (133/140, 95%), whereas 77 tumors (55%) were positive for PRTN3. Expression levels of P4HA2 and PRTN3 did not separately correlate with disease-free or overall survival, in either uni- or multivariable analysis. However, a low P4HA2 and high PRTN3 expression correlated with shorter disease-free survival (median 7.0 vs. 13.4 months, adjusted HR 3.24, 95% CI: 1.13-9.25, p = .028) and overall survival (median 8.5 vs. 25.8 months, adjusted HR 8.14, 95% CI: 3.41-19.44, p < .001). CONCLUSION: Our data show that a low P4HA2 and high PRTN3 expression correlates with poor survival in patients with pancreatic cancer, indicating the involvement of collagen deposition in the restraint of the tumor. The tumoral expression of PRTN3 reinforces the therapeutic potential of PR1-targeting immunotherapy in pancreatic cancer.

Stromal fibronectin expression in patients with resected pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is characterized by an extremely dense stroma, which has a fundamental role in tumor progression. Fibronectin (FN1) is the main constituent of the tumor stroma in pancreatic cancer. This study aimed to explore the association between FN1 and clinicopathological characteristics and disease survival. METHODS: Formalin-fixed paraffin-embedded tissue samples from 138 patients with PDAC were constructed into a tissue microarray, followed by immunohistochemical analysis with a recombinant monoclonal FN1 antibody. Chi-square test or Fisher's exact test were used for comparison of FN1 expression and relevant clinicopathological parameters. Kaplan-Meier survival curves and Cox regression analyses were used to assess the association between FN1 and survival. RESULTS: FN1 was detected in the stromal compartment in most cases (117/138, 84.8%). Compared to the low FN1 expression group, the high FN1 expression group had significantly larger tumor size (P = 0.002), more advanced T stage (P = 0.039) and N stage (P = 0.009), and also worse AJCC stage (P = 0.003). However, stromal FN1 expression was not associated with disease-free survival or overall survival. CONCLUSIONS: This study suggests that high stromal FN1 expression is associated with aggressive tumor characteristics in patients with resected PDAC. However, no association between FN1 expression and survival was found.

Galectin 4 is a biomarker for early recurrence and death after surgical resection for pancreatic ductal adenocarcinoma.

BACKGROUND: Galectins are a group of carbohydrate-binding proteins that are involved in neoplastic development and progression. In a previous mass spectrometry-based study, we identified galectin 4 as a down-regulated protein in short-term survivors of pancreatic cancer. This study was performed to validate the prognostic value of galectin 4 in a larger cohort of pancreatic cancer patients undergoing surgical resection. METHODS: Galectin 4 expression was evaluated by tissue microarrays and immunohistochemistry in 140 patients with surgically resected pancreatic cancer. Kaplan-Meier and Cox proportional hazards modeling were used to explore the association between galectin 4 and survival. RESULTS: Galectin 4 staining expression was positive in 111 cases (79.3%). The expression of galectin 4 was significantly associated with tumor size (p = .008) and differentiation (p = .001). Galectin 4 expression was significantly correlated with disease recurrence within 1 year of surgery (adjusted HR 0.485, p = .027). There was also a significant association between galectin 4 and overall survival at 1 year (adjusted HR 0.482, p = .047) and at 3 years (adjusted HR 0.550, p = .025). CONCLUSION: Galectin 4 expression is a novel biomarker for early recurrence and mortality after surgical resection for pancreatic cancer.

Low MUC4 expression is associated with survival benefit in patients with resectable pancreatic cancer receiving adjuvant gemcitabine.

BACKGROUND: Previous in vitro studies have shown that mucin 4 (MUC4) confers resistance toward gemcitabine in pancreatic cancer cells. To date, there are few clinical studies corroborating these findings. The aim of this study was to evaluate the predictive impact of MUC4 expression on survival in patients with resectable pancreatic cancer receiving adjuvant gemcitabine. MATERIALS AND METHODS: MUC4 expression was investigated by immunohistochemistry in 78 tissue sections from patients with pancreatic ductal adenocarcinoma undergoing Whipple resection. The H-score was used to evaluate MUC4 expression. The Kaplan-Meier method and Cox proportional hazards regression analysis were used to assess the predictive role of MUC4 expression. RESULTS: The MUC4 protein was expressed in 93.6% (73/78) of pancreatic cancer tissue specimens. None of the normal control pancreatic tissues had any MUC4 expression. Low MUC4 expression (H-score ≤100) was detectable in 42 (53.8%) of tumors and high MUC4 expression (H-score >100) was detectable in 36 (46.2%) of tumors. Low expression of MUC4 was associated with favorable survival (p = .027), whereas high MUC4 expression did not correlate with survival (p = .87) in patients receiving adjuvant gemcitabine treatment. CONCLUSIONS: This is the first study indicating a predictive role of MUC4 expression for gemcitabine treatment in the clinical setting.

Conditionally immortalized human pancreatic stellate cell lines demonstrate enhanced proliferation and migration in response to IGF-I.

Pancreatic stellate cells (PSCs) play a key role in the dense desmoplastic stroma associated with pancreatic ductal adenocarcinoma. Studies on human PSCs have been minimal due to difficulty in maintaining primary PSC in culture. We have generated the first conditionally immortalized human non-tumor (NPSC) and tumor-derived (TPSC) pancreatic stellate cells via transformation with the temperature-sensitive SV40 large T antigen and human telomerase (hTERT). These cells proliferate at 33°C. After transfer to 37°C, the SV40LT is switched off and the cells regain their primary PSC phenotype and growth characteristics. NPSC contained cytoplasmic vitamin A-storing lipid droplets, while both NPSC and TPSC expressed the characteristic markers αSMA, vimentin, desmin and GFAP. Proteome array analysis revealed that of the 55 evaluated proteins, 27 (49%) were upregulated ≥3-fold in TPSC compared to NPSC, including uPA, pentraxin-3, endoglin and endothelin-1. Two insulin-like growth factor binding proteins (IGFBPs) were inversely expressed. Although discordant IGFBP-2 and IGFBP-3 levels, IGF-I was found to stimulate proliferation of both NPSC and TPSC. Both basal and IGF-I stimulated motility was significantly enhanced in TPSC compared to NPSC. In conclusion, these cells provide a unique resource that will facilitate further study of the active stroma compartment associated with pancreatic cancer.