The clinicopathological significance and relationship of Gli1, MDM2 and p53 expression in resectable pancreatic cancer

Ehrlichia SLiM ligand mimetic activates Hedgehog signaling to engage a BCL-2 anti-apoptotic cellular program

Ehrlichia chaffeensis (E. chaffeensis) has evolved eukaryotic ligand mimicry to repurpose multiple cellular signaling pathways for immune evasion. In this investigation, we demonstrate that TRP120 has a novel repetitive short linear motif (SLiM) that activates the evolutionarily conserved Hedgehog (Hh) signaling pathway to inhibit apoptosis. In silico analysis revealed that TRP120 has sequence and functional similarity with Hh ligands and a candidate Hh ligand SLiM was identified. siRNA knockdown of Hh signaling and transcriptional components significantly reduced infection. Co-immunoprecipitation and surface plasmon resonance demonstrated that rTRP120-TR interacted directly with Hh receptor Patched-2 (PTCH2). E. chaffeensis infection resulted in early upregulation of Hh transcription factor GLI-1 and regulation of Hh target genes. Moreover, soluble recombinant TRP120 (rTRP120) activated Hh and induced gene expression consistent with the eukaryotic Hh ligand. The TRP120-Hh-SLiM (NPEVLIKD) induced nuclear translocation of GLI-1 in THP-1 cells and primary human monocytes and induced a rapid and expansive activation of Hh pathway target genes. Furthermore, Hh activation was blocked by an α-TRP120-Hh-SLiM antibody. TRP120-Hh-SLiM significantly increased levels of Hh target, anti-apoptotic protein B-cell lymphoma 2 (BCL-2), and siRNA knockdown of BCL-2 dramatically inhibited infection. Blocking Hh signaling with the inhibitor Vismodegib, induced a pro-apoptotic cellular program defined by decreased mitochondria membrane potential, significant reductions in BCL-2, activation of caspase 3 and 9, and increased apoptotic cells. This study reveals a novel E. chaffeensis SLiM ligand mimetic that activates Hh signaling to maintain E. chaffeensis infection by engaging a BCL-2 anti-apoptotic cellular program.

Silencing glioma-associated oncogene homolog 1 suppresses the migration and invasion of hepatocellular carcinoma in vitro

Hepatocellular carcinoma (HCC) is the fourth most common cause of cancer-associated death worldwide. Glioma-associated oncogene homolog 1 (Gli1) is a key component and functions as a reliable marker of Hedgehog signaling pathway activation. Previous studies have demonstrated that Gli1 serves important roles in the progression of various types of cancer, including HCC. However, its effect on HCC invasion and metastasis and the underlying mechanism remain to be elucidated. Small interference RNA was employed to silence the Gli1 gene in liver cancer cells. Reverse transcription-quantitative PCR and western blot analysis were performed to evaluate the mRNA and protein expression of Gli1, respectively. A series of assays, including Cell Counting Kit-8, adhesion, wound healing and Matrigel invasion were performed to investigate cell viability, adhesive, migratory and invasive capabilities of liver cancer cells, respectively. In addition, immunofluorescence staining was performed to determine the cellular localization of focal adhesion kinase (FAK), phosphorylated (p-)FAK and p-AKT. The mRNA and protein expression of Gli1 in liver cancer cells (HepG2 and SK-Hep1) were markedly decreased in a dose-dependent manner following Gli1-knockdown. Gli1 silencing significantly inhibited the adhesion, migration and invasion of SK-Hep1 cells. Additionally, knockdown of Gli1 markedly suppressed the expression of metalloproteinase (MMP)-2 and MMP-9. Furthermore, downregulation of Gli1 blocked the FAK/AKT signaling pathway. Gli1 serves significant roles in the migration and invasion of HCC cells through activation of the FAK/AKT signaling pathway and subsequent upregulation of MMP-2 and MMP-9 expression. Thus, Gli1 may be a potential protein target for the regulation of HCC migration and invasion.

GLI1 expression in pancreatic ductal adenocarcinoma correlates the clinical significance and prognosis: A meta-analysis

BACKGROUND

Glioma-associated oncogene homolog 1(GLI1) expression correlates with the clinical significance and prognosis of several cancers. However, the evaluation of the role GLI1 expression plays in pancreatic ductal adenocarcinoma (PDAC) clinicopathological features and outcomes still lacks.

OBJECTIVE

The present study systemic reviewed the association of GLI1 expression and clinical significance as well as patients survival in PDAC.

METHODS

We systematically searched the database of The Cochrane Library, PubMed, Embase, CNKI, Weipu data, and Wanfang data according to the inclusion and exclusion criteria. (The search ended on January 1, 2019; no language restrictions). The Newcastle-Ottawa Scale (NOS) scale was implemented to assess the quality of the literature and the Review Manager 5.3 Software was used to conduct a meta-analysis. Finally, 9 studies, a total of 1058 patients, have been included.

RESULTS

GLI1 is more likely expressed in PDAC tissue rather than para-carcinoma tissue (OR = 2.86, 95%CI = 1.87-4.36, P < .00001). GLI1 expression is associated with the TNM stage (OR = 3.11, 95%CI = 2.01-4.79, P < .00001), perineural invasion (OR = 2.50, 95%CI = 1.28-4.91, P = .008), and lymphatic metastasis (OR = 2.73, 95%CI = 1.71-4.36, P < .0001). But the association with differentiation (OR = 1.20, 95%CI = 0.74-1.96, P = .46) and tumor size (OR = 2.41, 95%CI = 0.97-6.00, P = .06) was not significant. GLI1 expression is related to the worse overall survival in PDACs (HR = 1.68, 95%CI = 1.40-2.02, P < .00001).

CONCLUSION

Positive GLI1 expression promotes the progression and metastasis of PDACs and plays an important role in the clinical significance and the patients survival.

Gli1 regulates stemness characteristics in gastric adenocarcinoma

Background

Glioma-associated oncogene homolog 1 (Gli1), affects the progression and the stemness characteristics of malignant carcinoma. The aim of the present study was to identify the relation between Glioma-associated oncogene homolog 1 (Gli1) and stemness and determine its clinical significance in gastric adenocarcinoma (GA). We investigated Gli1 expression and its correlation with other stemness-associated proteins in 169 GA samples and 5 GA cell lines.

Methods

To elucidate the role of Gli1 in the clinicopathological significance and stemness of GA, tissues samples from 169 GA patients were collected for immunohistochemistry (IHC). Additionally, MKN74, MKN28, NCI-N87, SNU638, AGS cells were collected for western blotting, MKN28 cells were collected for spheroid formation assay.

Results

Results showed that Gli1 expression was closely related to tumor grade, primary tumor (pT) stage, distant metastasis, clinical stage, gross type, microvessel density, and shorter overall survival (OS). Cox regression analysis verified that Gli1 was an independent prognostic factor for OS. Furthermore, Gli1 expression correlated with the expression of stemness-related genes, CD44, LSD1, and Sox9. Gli1 inhibitor GANT61 significantly decreased the expression of CD44 and LSD1, and spheroid formation ability of the MKN28 cells.

Conclusions

In conclusion, Gli1 may be a poor prognostic indicator and a potential cancer stemness-related protein in GA.

Phase 1 trial of Vismodegib and Erlotinib combination in metastatic pancreatic cancer

BACKGROUND/OBJECTIVES

Interplay between the Hedgehog (HH) and epidermal growth factor receptor (EGFR) pathways modulating the outcome of their signaling activity have been reported in various cancers including pancreatic ductal adenocarcinoma (PDAC). Therefore, simultaneous targeting of these pathways may be clinically beneficial. This Phase I study combined HH and EGFR inhibition in metastatic PDAC patients.

METHODS

Combined effects of HH and EGFR inhibition using Vismodegib and Erlotinib with or without gemcitabine in metastatic solid tumors were assessed by CT. Another cohort of patients with metastatic PDAC was evaluated by FDG-PET and tumor biopsies-derived biomarkers.

RESULTS

Treatment was well tolerated with the maximum tolerated dose cohort experiencing no grade 4 toxicities though 25% experienced grade 3 adverse effects. Recommended phase II dose of Vismodegib and Erlotinib were each 150 mg daily. No tumor responses were observed although 16 patients achieved stable disease for 2-7 cycles. Paired biopsy analysis before and after first cycle of therapy in PDAC patients showed reduced GLI1 mRNA, phospho-GLI1 and associated HH target genes in all cases. However, only half of the cases showed reduced levels of desmoplasia or changes in fibroblast markers. Most patients had decreased phospho-EGFR levels.

CONCLUSIONS

Vismodegib and Erlotinib combination was well-tolerated although overall outcome in patients with metastatic PDAC was not significantly impacted by combination treatment. Biomarker analysis suggests direct targets inhibition without significantly affecting the stromal compartment. These findings conflict with pre-clinical mouse models, and thus warrant further investigation into how upstream inhibition of these pathways is circumvented in PDAC.

BZW2 promotes the malignant progression of colorectal cancer via activating the ERK/MAPK pathway

Colorectal cancer (CRC) is one of the most prevalent malignant solid cancers worldwide involving the dysregulation of multiple signaling molecules. However, the role and corresponding mechanism of basic leucine zipper and W2 domains 2 (BZW2) in CRC development, to our knowledge, has not been reported. We found BZW2 was overexpressed in human CRC tissues compared with that in paired adjacent colorectal samples. BZW2 overexpression was closely associated with tumor T stage (p = .030), metastatic lymph nodes (p = .037), TNM stage (p = .018) and the worse prognosis of CRC patients (p = .009). Moreover, BZW2 was an independent disadvantage prognostic factor (p = .031). BZW2 also showed an increased expression in different invasive CRC cell lines. Its silencing and overexpression diminished and increased cell proliferation, invasion, and migration in Colo205 and HCT116 cells via specifically activating of extracellular-signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signaling. Moreover, ERK/MAPK inhibitor PD98059 reverse the enhancement of cell proliferation, invasion, and migration in BZW2 overexpressing HCT116 cells. BZW2 silencing also inhibited subcutaneous tumors growth and p-ERK expression in vivo. BZW2 promotes the malignant progression of CRC via activating ERK/MAPK signaling, which provided a promising gene target therapy for CRC.

Upregulation of Twist is involved in Gli1 induced migration and invasion of hepatocarcinoma cells

Hedgehog (Hh) signaling is involved in the progression of hepatocellular carcinoma (HCC), while its detailed mechanisms are not well illustrated. Our present study revealed that the expression of Gli1, while not Gli2 or Gli3, is significantly increased in HCC cell lines and 20/28 (71.4%) HCC tissues as compared with their corresponding controls. Over expression of Gli1 can promote the migration, invasion and epithelial-mesenchymal transition (EMT) of HCC cells. Gli1 can increase the expression of Twist, while not other EMT transcription factors such as Snail, ZEB1 or Slug. Gli1 increases the transcription of Twist while it has no significant effect on the protein or mRNA stability. Chromatin immunoprecipitation-polymerase chain reaction confirms that Gli1 can directly bind to the promoter of Twist, in which the third binding site is essential for Gli1 induced transcription. Collectively, our data suggest that upregulation of Twist is involved in Gli1 induced migration and invasion of HCC cells.

Prognostic and clinicopathological value of Gli-1 expression in gastric cancer: A meta-analysis

Glioma associated oncogene-1 (Gli-1) is considered as a strong positive activator of downstream target genes of hedgehog signal pathway in mammalians. However, its diagnostic and prognostic value in gastric cancer remains unclear and controversial. Therefore, a quantitative meta-analysis was conducted to determine the clinical value of Gli-1 in gastric cancer patients. Twelve eligible articles with 886 gastric cancer patients were included in this meta-analysis. The relationship between Gli-1 expression in gastric cancer patients and clinicopathological features and 5-year overall survival (OS) was evaluated using pooled odds ratios (ORs) and hazard ratio (HR) with 95% confidence intervals (CIs). The meta-analysis showed that the upregulated Gli-1 was associated with sample type (gastric cancer tissues) (OR 10.31, 95%CI 7.14-14.88; P = 0.000), differentiation type (OR 3.76, 95%CI 2.55-5.53; P = 0.000), depth of invasion (OR 8.17, 95%CI 3.60-18.55; P = 0.000), lymph node metastasis (OR 3.97, 95%CI 2.73-5.78; P = 0.000) and high TNM stage (OR 3.65, 95%CI 1.89-7.04; P = 0.000). Three studies including 316 patients were assessed for the correlation between Gli-1 and 5-year OS, which indicated that positive Gli-1 expression was associated with poor prognosis in gastric cancer patients (HR 2.14, 95%CI 1.35-3.40; P = 0.001). Little publication bias was identified by funnel plots and Egger's tests. The sensitivity analysis indicated that no study substantially influenced pooled OR/HR. Taken together, Gli-1 is a credible indicator for highly aggressive tumor with poor prognosis in gastric cancer patients.

Targeting of miR-150 on Gli1 gene to inhibit proliferation and cell cycle of esophageal carcinoma EC9706

OBJECTIVE

Glioma-associated oncogene homolog 1 (Gli1) in Hedgehog signal pathway regulates Cyclin D1 expression, cell cycle or proliferation modulation. Esophageal cancer patients had significantly elevated Gli1 expression, which is related with survival and prognosis. It has been demonstrated that the level of miR-150 was decreased in esophageal cancer patients compared to normal control. As a complementary relationship exists between miR-150 and 3'-UTR of Gli1, this study investigated if miR-150 played a role in regulating Gli1 expression, and proliferation or cell cycle of esophageal cancer cells.

PATIENTS AND METHODS

Esophageal squamous cell carcinoma (ESCC) patients from our hospital were recruited to collect tumor and adjacent tissues for miR-150 and Gli1 expression. Esophageal carcinoma cell line EC9706 and normal esophageal epithelial cell line HEEC were compared for expression of miR-150, Gli1 and Cyclin D1. Dual luciferase reporter gene assay examined the targeted relationship between miR-150 and 3'-UTR of Gli1. In vitro cultured EC9706 cells were treated with miR-150 mimic, si-Gli1 or the combination of miR-150 mimic and si-Gli1, respectively, to check their gene expression, cell cycle and proliferation.

RESULTS

ESCC tissues had significantly higher Gli1 expression and lower miR-150 expression. EC9706 cell also had higher Gli1 expression than that in HEEC, whilst miR-150 was down-regulated. Via targeting 3'-UTR of Gli1 gene, miR-150 inhibited its expression. Transfection of miR-150 mimic, si-Gli1 or the combination of miR-150 mimic and si-Gli1, respectively, remarkably decreased expression of Gli1 and Cyclin D1 expression in EC9706 cells, whose cell cycle arresting at G0/G1 phase was enhanced with weakened proliferation.

CONCLUSIONS

MiR-150 can induce G0/G1 cell cycle arresting and weaken proliferation of esophageal carcinoma cells via targeted inhibition on Gli1 and downstream expression of Cyclin D1.

miR-509-5p inhibits cellular proliferation and migration via targeting MDM2 in pancreatic cancer cells

Objective

This study aimed to explore the effect of miR-509-5p on pancreatic cancer progression and clarify the underlying mechanisms.

Methods

Real-time quantitative reverse transcription polymerase chain reaction was employed to determine miR-509-5p expression in pancreatic cancer tissues and noncancerous adjacent tissues. CCK-8 and Transwell experiments were employed to examine cellular proliferation, migration, and invasion after miR-509-5p mimic or inhibitor transfection. Bioinformatics tools were used to identify the target gene of miR-509-5p, and cotransfection of the target gene and miR-509-5p mimic was performed to determine the effect on the proliferation and migration of pancreatic cancer cells. A xenograft mouse model and histological analysis were also used to test the effect of miR-509-5p on tumor growth in vivo.

Results

miR-509-5p expression was dramatically downregulated in pancreatic cancer tissues and in pancreatic cancer cell lines. miR-509-5p mimic markedly inhibited PANC-1 cell proliferation, migration, and invasion. Conversely, miR-509-5p inhibitor promoted PANC-1 cell proliferation, migration, and invasion. Furthermore, the 3′UTR–specific target site luciferase reporter assay also showed that miR-509-5p negatively regulated MDM2 at the post-transcriptional level. miR-509-5p effectively reversed the MDM2 overexpression-induced increase in PANC-1 cell proliferation and invasion. Moreover, miR-509-5p inhibited tumor growth and accelerated cell death in the tumor samples.

Conclusions

Our results suggested that miR-509-5p served as a new tumor suppressor via targeting the MDM2 gene, inhibiting pancreatic cancer progression.

Evaluation of K-ras and p53 expression in pancreatic adenocarcinoma using the cancer genome atlas

Genetic alterations in K-ras and p53 are thought to be critical in pancreatic cancer development and progression. However, K-ras and p53 expression in pancreatic adenocarcinoma have not been systematically examined in The Cancer Genome Atlas (TCGA) Data Portal. Information regarding K-ras and p53 alterations, mRNA expression data, and protein/protein phosphorylation abundance was retrieved from The Cancer Genome Atlas (TCGA) databases, and analyses were performed by the cBioPortal for Cancer Genomics. The mutual exclusivity analysis showed that events in K-ras and p53 were likely to co-occur in pancreatic adenocarcinoma (Log odds ratio = 1.599, P = 0.006). The graphical summary of the mutations showed that there were hotspots for protein activation. In the network analysis, no solid association between K-ras and p53 was observed in pancreatic adenocarcinoma. In the survival analysis, neither K-ras nor p53 were associated with both survival events. As in the data mining study in the TCGA databases, our study provides a new perspective to understand the genetic features of K-ras and p53 in pancreatic adenocarcinoma.

Prognostic role of Gli1 expression in solid malignancies: a meta-analysis

Gli1 is a downstream transcriptional factor of Sonic hedgehog pathway in mammalians, and has been recognized as a proliferative indicator of carcinogenesis. However, its actual role in prognosis among solid malignancies remains unclear. Therefore we performed this meta-analysis aiming to discover the correlation between Gli1 positivity and clinical prognosis in patients suffering from diverse carcinomas. A total of 39 studies containing 4496 cases were selected into our quantitative analysis via electronic database search. Original data of 3-year, 5-year, 10-year overall survival and disease-free survival were extracted and calculated using odds ratio and Mantel-Haenszel model. Subgroup analysis was also conducted to clarify the possible confounding factors. P < 0.05 was considered significant in statistics. Gli1 redundancy was associated with worse 3-year, 5-year, 10-year overall survival and disease-free survival in solid malignancies. Different source regions, sample-size, mean-age and detection approaches had no impact on the negative prognostic effect of Gli1 over-expression. Nevertheless, stratified by cancer type and subcellular localization, cytoplasmic Gli1 expression and Gli1 positivity in intracranial tumors was not correlated to poorer 3-year and 5-year prognosis. The over-expression of Gli1 is a credible indicator of poorer prognosis in most of solid malignancies, irrespective of intracranial tumors.

Dual inhibition of nuclear factor kappa-B and Mdm2 enhance the antitumor effect of radiation therapy for pancreatic cancer

INTRODUCTION

Radiation therapy, alone or in combination with chemotherapy, is effective for patients with locally advanced and recurrent pancreatic cancer. Ionizing radiation induces cell cycle arrest and cell apoptosis through enhancement several signals such as p53, p21(Waf1/Cip1), and caspase. However, the therapeutic efficacy is attenuated by radiation-induced activation of NF-κB. Nafamostat mesilate, a synthetic serine protease inhibitor, inhibits NF-κB activation in pancreatic cancer. Therefore, we hypothesized that nafamostat mesilate inhibited radiation-induced activation of NF-κB and improves therapeutic outcome.

RESULTS

In combination group, NF-κB activation was significantly inhibited in comparison with that of radiation group. Nafamostat mesilate obviously down-regulated the expression levels of Mdm2 compared with control cells or irradiated cells. Consequently, p53 expression was stabilized inversely in correlation with Mdm2 protein expression level. The expression levels of p53, p21(Waf1/Cip1), cleaved caspase-3 and -8 were the highest in the combination group. Nafamostat mesilate enhanced ionizing radiation-induced cell apoptosis and G2/M cell cycle arrest. In combination group, cell proliferation and tumor growth were significantly slower than those in other groups.

CONCLUSION

Combination therapy of radiation with nafamostat mesilate exerts enhanced anti-tumor effect against human pancreatic cancer.

The hedgehog antagonist HHIP as a favorable prognosticator in glioblastoma

Inactivation of hedgehog-interacting protein (HHIP) and overexpression of Gli1 play vital roles in the development of diverse human cancers. The aim of this study is to examine the association of HHIP and Gli1 with the clinicopathologic features and prognosis of patients with glioblastoma (GBM). The expression of HHIP and Gli1 in 103 patients with GBM and 32 control patients was investigated by immunohistochemistry. Statistical analysis was utilized to evaluate the association of HHIP as well as Gli1 with clinicopathological characteristics and prognosis of patients. HHIP and Gli1 were dysregulated in GBM. Spearman's rank analysis showed that HHIP and Gli1 had an inverse correlation (r = -0.386, P = 0.000). Expression of HHIP was significantly correlated with age (P = 0.000), gender (P = 0.003), seizure (P = 0.013), resection degree (P = 0.033), adjuvant treatment (P = 0.030), and O(6)-methylguanine-DNA methyltransferase (MGMT) methylation (P = 0.021), while Gli1 expression was significantly correlated with age (P = 0.002), gender (P = 0.033), Karnofsky performance status (KPS) score (P = 0.028), resection degree (P = 0.000), adjuvant treatment (P = 0.014), and MGMT methylation (P = 0.030). Kaplan-Meier method showed that patients with low Gli1 expression had longer overall survival (OS) than those with high Gli1 expression (P = 0.000) and the OS of the patients with HHIP-positive GBM was significantly longer than that of the patients with HHIP-negative GBM (P = 0.000). Univariate and multivariate analyses confirmed that HHIP expression and Gli1 expression were independent prognostic factors. Our data suggested that expression of HHIP could be considered as significant prognostic marker for patients with GBM.

Cell-block procedure in endoscopic ultrasound-guided-fine-needle-aspiration of gastrointestinal solid neoplastic lesions

In the present review we have analyzed the clinical applications of endoscopic ultrasound-guided-fine-needle-aspiration (EUS-FNA) and the methodological aspects obtained by cell-block procedure (CBP) in the diagnostic approach to the gastrointestinal neoplastic pathology. CBP showed numerous advantages in comparison to the cytologic routine smears; in particular, better preservation of cell architecture, achievement of routine haematoxylin-eosin staining equivalent to histological slides and possibility to perform immunohistochemistry or molecular analyses represented the most evident reasons to choose this method. Moreover, by this approach, the differential diagnosis of solid gastrointestinal neoplasias may be more easily achieved and the background of contaminant non-neoplastic gastrointestinal avoided. Finally, biological samples collected by EUS-FNA CBP-assisted should be investigated in order to identify and quantify further potential molecular markers.

Gli1 promotes transforming growth factor-beta1- and epidermal growth factor-induced epithelial to mesenchymal transition in pancreatic cancer cells

BACKGROUND

The Hedgehog signaling pathway and its key target effector Gli1 are linked closely to the development of the epithelial to mesenchymal transition (EMT) in many cancers. The definite function of Gli1 in regulating the EMT of pancreatic cancer (PC), however, is still unclear.

METHODS

At the cell and tissue levels, we investigated the role of Gli1 in the initiation of EMT in PC with and without external stimulus treatments.

RESULTS

The immunohistochemistry results showed that Gli1 was associated positively with MMP9 but not with E-cad or Vimentin. Gli1 expression was associated positively with tumor T (P = .025) and Union for International Cancer Control stage (P = .032), whereas MMP9 expression was associated positively with lymph node metastasis (P = .017) and Union for International Cancer Control stage (P = .006). Furthermore, patients with Gli1 and MMP9 coexpression had poor overall survival (P = .015). Silencing of Gli1 alone without external stimulus had no effect on EMT but inhibited transforming growth factor-beta1 (TGFβ1)- and epidermal growth factor (EGF)-induced EMT in PANC-1, AsPC-1, and BxPC-3 PC cell lines, along with the inhibition of TGFβ1- and EGF-induced EMT-like cell morphology and invasion, down-regulation of E-cad, and up-regulation of MMP9 and Vimentin in those 3 cell lines, respectively.

CONCLUSION

Gli1 silencing alone has no effect on EMT initiation; however, it exerts a protumor role in the aggressive invasion of PC cells by promoting TGFβ1- and EGF-induced EMT.

Endoscopic ultrasound-guided fine-needle aspiration cytology in pancreaticobiliary carcinomas: diagnostic efficacy of cell-block immunocytochemistry

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration cytology was demonstrated to be a useful tool for the diagnosis and staging of pancreaticobiliary neoplastic lesions. Nonetheless, the diagnostic value of this procedure may be limited by low cellularity of the specimen, contamination of intestinal cells and unfeasibility of ancillary immunocytochemical procedures. The present study was to evaluate its usefulness in the diagnosis of neoplastic lesions.

METHODS

A series of 46 pancreaticobiliary carcinomas with available cell block preparations was submitted to immunocytochemistry against cytokeratins, carcinoembryonic antigen, E-cadherin, CD10 and p53. The sensitivity, specificity, positive and negative predictive values of the cytological smear in the discrimination of malignant lesions were calculated and compared with those of cell block preparation with the immunocytochemical stains against p53 and CD10.

RESULTS

According to our findings, the use of cell block preparations together with immunostains against p53 and CD10 allowed to discriminate malignant versus benign specimens with higher sensitivity than the only cytological examination. In detail, CD10 immunostaining was of significant help for the discrimination between cytological contaminants, such as benign gastrointestinal cells, and the neoplastic elements of pancreaticobiliary well differentiated adenocarcinomas. Also, intense nuclear immunoreactivity for p53 was encountered in about 2/3 of the cases and identified pancreatic malignancy with high sensitivity.

CONCLUSIONS

We suggest that immunocytochemistry against both CD10 and p53 could be applied case by case, mainly to differentiate gastrointestinal and pancreatic benign cellular contaminants showing hyperplasia or reactive changes from differentiated pancreaticobiliary adenocarcinomas.

The overexpression of SOX2 affects the migration of human teratocarcinoma cell line NT2/D1

The altered expression of the SOX2 transcription factor is associated with oncogenic or tumor suppressor functions in human cancers. This factor regulates the migration and invasion of different cancer cells. In this study we investigated the effect of constitutive SOX2 overexpression on the migration and adhesion capacity of embryonal teratocarcinoma NT2/D1 cells derived from a metastasis of a human testicular germ cell tumor. We detected that increased SOX2 expression changed the speed, mode and path of cell migration, but not the adhesion ability of NT2/D1 cells. Additionally, we demonstrated that SOX2 overexpression increased the expression of the tumor suppressor protein p53 and the HDM2 oncogene. Our results contribute to the better understanding of the effect of SOX2 on the behavior of tumor cells originating from a human testicular germ cell tumor. Considering that NT2/D1 cells resemble cancer stem cells in many features, our results could contribute to the elucidation of the role of SOX2 in cancer stem cells behavior and the process of metastasis.

Down-regulation of Gli-1 inhibits hepatocellular carcinoma cell migration and invasion

Glioma-associated oncogene homolog-1 (Gli-1) is considered a marker of Hedgehog pathway activation and is associated with the progression of several cancers. We have previously reported that Gli-1 was correlated with invasion and metastasis in hepatocellular carcinoma (HCC). However, the exact roles and mechanisms of Gli-1 in HCC invasion are unclear. In this study, we found that small interfering RNA mediated down-regulation of Gli-1 expression significantly suppressed adhesion, motility, migration, and invasion of both SMMC-7721 and SK-Hep1 cells. Furthermore, down-regulation of Gli-1 significantly reduced expressions and activities of both matrix metalloproteinase (MMP)-2 and MMP-9. In addition, we found that down-regulation of Gli-1 resulted in up-regulation of E-cadherin and concomitant down-regulation of Snail and Vimentin, consistent with inhibition of epithelial-mesenchymal transition (EMT). Taken together, our results suggest that down-regulation of Gli-1 suppresses HCC cell migration and invasion likely through inhibiting expressions and activations of MMP-2, 9 and blocking EMT.

Inactivation of the transcription factor GLI1 accelerates pancreatic cancer progression

The role of GLI1 in pancreatic tumor initiation promoting the progression of preneoplastic lesions into tumors is well established. However, its function at later stages of pancreatic carcinogenesis remains poorly understood. To address this issue, we crossed the gli1 knock-out (GKO) animal with cre-dependent pancreatic activation of oncogenic kras concomitant with loss of the tumor suppressor tp53 (KPC). Interestingly, in this model, GLI1 played a tumor-protective function, where survival of GKO/KPC mice was reduced compared with KPC littermates. Both cohorts developed pancreatic cancer without significant histopathological differences in survival studies. However, analysis of mice using ultrasound-based imaging at earlier time points showed increased tumor burden in GKO/KPC mice. These animals have larger tumors, decreased body weight, increased lactate dehydrogenase production, and severe leukopenia. In vivo and in vitro expression studies identified FAS and FAS ligand (FASL) as potential mediators of this phenomenon. The FAS/FASL axis, an apoptotic inducer, plays a role in the progression of pancreatic cancer, where its expression is usually lost or significantly reduced in advanced stages of the disease. Chromatin immunoprecipitation and reporter assays identified FAS and FASL as direct targets of GLI1, whereas GKO/KPC mice showed lower levels of this ligand compared with KPC animals. Finally, decreased levels of apoptosis were detected in tumor tissue in the absence of GLI1 by TUNEL staining. Together, these findings define a novel pathway regulated by GLI1 controlling pancreatic tumor progression and provide a new theoretical framework to help with the design and analysis of trials targeting GLI1-related pathways.