KOC (K homology domain containing protein overexpressed in cancer): a novel molecular marker that distinguishes between benign and malignant lesions of the pancreas

IGF2BPs as novel m6A readers: Diverse roles in regulating cancer cell biological functions, hypoxia adaptation, metabolism, and immunosuppressive tumor microenvironment

m6A methylation is the most frequent modification of mRNA in eukaryotes and plays a crucial role in cancer progression by regulating biological functions. Insulin-like growth factor 2 mRNA-binding proteins (IGF2BP) are newly identified m6A 'readers'. They belong to a family of RNA-binding proteins, which bind to the m6A sites on different RNA sequences and stabilize them to promote cancer progression. In this review, we summarize the mechanisms by which different upstream factors regulate IGF2BP in cancer. The current literature analyzed here reveals that the IGF2BP family proteins promote cancer cell proliferation, survival, and chemoresistance, inhibit apoptosis, and are also associated with cancer glycolysis, angiogenesis, and the immune response in the tumor microenvironment. Therefore, with the discovery of their role as 'readers' of m6A and the characteristic re-expression of IGF2BPs in cancers, it is important to elucidate their mechanism of action in the immunosuppressive tumor microenvironment. We also describe in detail the regulatory and interaction network of the IGF2BP family in downstream target RNAs and discuss their potential clinical applications as diagnostic and prognostic markers, as well as recent advances in IGF2BP biology and associated therapeutic value.

An Update on the Role of Immunohistochemistry in the Evaluation of Pancreatic/Liver/Gastrointestinal Luminal Tract Disorders

CONTEXT.—

Immunohistochemistry serves as an ancillary diagnostic tool for a wide variety of neoplastic and nonneoplastic disorders, including infections, workup of inflammatory conditions, and subtyping neoplasms of the pancreas/liver/gastrointestinal luminal tract. In addition, immunohistochemistry is also used to detect a variety of prognostic and predictive molecular biomarkers for carcinomas of the pancreas, liver, and gastrointestinal luminal tract.

OBJECTIVE.—

To highlight an update on the role of immunohistochemistry in the evaluation of pancreatic/liver/gastrointestinal luminal tract disorders.

DATA SOURCES.—

Literature review and authors' research data and personal practice experience were used.

CONCLUSIONS.—

Immunohistochemistry is a valuable tool, assisting in the diagnosis of problematic tumors and benign lesions of the pancreas, liver, and gastrointestinal luminal tract, and also in the prediction of prognosis and therapeutic response for carcinomas of the pancreas, liver, and gastrointestinal luminal tract.

Ancillary tests for hepatobiliary neoplasms: what we know and what we need to know

Ancillary tests are commonly used in the surgical pathology setting for diagnosing challenging neoplastic diseases of the liver and biliary tract, while histology and clinical correlation remain to be critically important. With continuous discoveries, more and more useful ancillary tests have become available, which can help distinguish between malignant and benign hepatocellular neoplasms, malignant and benign biliary tract entities, and intrahepatic and metastatic carcinomas. This review will focus on existing and emerging biomarkers (such as glutamine synthetase, organic anion transporting polypeptide 1B3, insulin-like growth factor-II mRNA binding protein-3, S100P, SMAD4, enhancer of zeste homolog 2, albumin, hepatocyte nuclear factor-1β, etc.) that can be used for the diagnosis, classification and prognostication of hepatobiliary neoplasms.

IGF2BP3 as a Prognostic Biomarker in Well-Differentiated/Dedifferentiated Liposarcoma

BACKGROUND

Although IGF2BP3 has been implicated in tumorigenesis and poor outcomes in multiple cancers, its role in soft-tissue sarcoma (STS) remains unknown. Preliminary data have suggested an association with IGF2BP3 expression among patients with well-differentiated/dedifferentiated liposarcoma (WD/DD LPS), a disease where molecular risk stratification is lacking.

METHODS

We examined the survival associations of IGF2BP3 via univariate and multivariate Cox regression in three unique datasets: (1) the Cancer Genome Atlas (TCGA), (2) an in-house gene microarray, and (3) an in-house tissue microarray (TMA). A fourth dataset, representing an independent in-house TMA, was used for validation.

RESULTS

Within the TCGA dataset, IGF2BP3 expression was a poor prognostic factor uniquely in DD LPS (OS 1.6 vs. 5.0 years, p = 0.009). Within the microarray dataset, IGF2BP3 expression in WD/DD LPS was associated with worse survival (OS 7.7 vs. 21.5 years, p = 0.02). IGF2BP3 protein expression also portended worse survival in WD/DD LPS (OS 3.7 vs. 13.8 years, p < 0.001), which was confirmed in our validation cohort (OS 2.7 vs. 14.9 years, p < 0.001). In the multivariate model, IGF2BP3 was an independent risk factor for OS, (HR 2.55, p = 0.034).

CONCLUSION

IGF2BP3 is highly expressed in a subset of WD/DD LPS. Across independent datasets, IGF2BP3 is also a biomarker of disease progression and worse survival.

Multi-omics analysis of N6-methyladenosine reader IGF2BP3 as a promising biomarker in pan-cancer

Background

Insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) has been reported to exhibit an oncogenic effect as an RNA-binding protein (RBP) by promoting tumor cell proliferation, migration and invasion in several tumor types. However, a pan-cancer analysis of IGF2BP3 is not currently available, and the exact roles of IGF2BP3 in prognosis and immunology in cancer patients remain enigmatic. The main aim of this study was to provide visualization of the systemic prognostic landscape of IGF2BP3 in pan-cancer and to uncover the potential relationship between IGF2BP3 expression in the tumor microenvironment and immune infiltration profile.

Methods

Raw data on IGF2BP3 expression were obtained from GTEx, CCLE, TCGA, and HPA data portals. We have investigated the expression patterns, diagnostic and prognostic significance, mutation landscapes, functional analysis, and functional states of IGF2BP3 utilizing multiple databases, including HPA, TISIDB, cBioPortal, GeneMANIA, GESA, and CancerSEA. Moreover, the relationship of IGF2BP3 expression with immune infiltrates, TMB, MSI and immune-related genes was evaluated in pan-cancer. IGF2BP3 with drug sensitivity analysis was performed from the CellMiner database. Furthermore, the expression of IGF2BP3 in different grades of glioma was detected by immunohistochemical staining and western blot.

Results

We found that IGF2BP3 was ubiquitously highly expressed in pan-cancer and significantly correlated with diagnosis, prognosis, TMB, MSI, and drug sensitivity in various types of cancer. Besides, IGF2BP3 was involved in many cancer pathways and varied in different immune and molecular subtypes of cancers. Additionally, IGF2BP3 is critically associated with genetic markers of immunomodulators in various cancers. Finally, we validated that IGF2BP3 protein expression was significantly higher in glioma than in normal tissue, especially in GBM.

Conclusions

IGF2BP3 may be a potential molecular biomarker for diagnosis and prognosis in pan-cancer, especially for glioma. It could become a novel therapeutic target for various cancers.

Current Pathology Model of Pancreatic Cancer

Pancreatic cancer (PC) is one of the most aggressive and lethal malignant neoplasms, ranking in seventh place in the world in terms of the incidence of death, with overall 5-year survival rates still below 10%. The knowledge about PC pathomechanisms is rapidly expanding. Daily reports reveal new aspects of tumor biology, including its molecular and morphological heterogeneity, explain complicated "cross-talk" that happens between the cancer cells and tumor stroma, or the nature of the PC-associated neural remodeling (PANR). Staying up-to-date is hard and crucial at the same time. In this review, we are focusing on a comprehensive summary of PC aspects that are important in pathologic reporting, impact patients' outcomes, and bring meaningful information for clinicians. Finally, we show promising new trends in diagnostic technologies that might bring a difference in PC early diagnosis.

A Promising Diagnostic Role of Immunohistochemical Expression of Insulin-Like Growth Factor II mRNA Binding Protein 3 (IMP3) in Pancreatic Lesions Using Endoscopic Ultrasound-Guided Fine Needle Aspiration (EUS-FNA) Cytology

BACKGROUND

Poor prognosis and short survival of patients harboring pancreatic cancer emerge how advanced disease it is. In a trial to achieve the earliest and most accurate diagnosis to manage this progressive disease, we proposed that using endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with an adjuvant diagnostic immunohistochemical marker would give better diagnostic results. IMP3 has gained recently wide attention, as many studies found that IMP3 has not only diagnostic but also prognostic role in different types of malignancies.

AIM OF THE STUDY

This prospective work is to assess the diagnostic role of EUS-FNA combined with the immunohistochemical expression of IMP3 on different benign and malignant pancreatic lesions.

MATERIAL AND METHOD

The included pancreatic lesions (n = 140) were obtained by EUS-FNA technique and stained for IMP3 immunohistochemically. Paraffin blocks from patients who underwent excision (n = 92) or core biopsies (n = 48) were performed for confirming diagnosis.

RESULTS

The combined method for diagnosis showed that IMP3 was positive in 78.7%, 91.7%, 100% PAC, mucinous neoplasm with high grade dysplasia, and IPMN with high grade dysplasia, respectively, while almost all benign lesions showed negative IMP3. Also, this method showed sensitivity (78.26%), specificity (95.83%), and accuracy (84.3%).

CONCLUSION

EUS-FNA cytology with IMP3 could be a reliable diagnostic tool especially for assessment of malignant pancreatic lesions.

Diagnostic value of IMP3 and p53 immunohistochemical staining in EUS-guided fine-needle aspiration for solid pancreatic tumors

We previously identified insulin-like growth factor-II messenger ribonucleic acid-binding protein 3 (IMP3) as a valuable marker to distinguish malignant from benign lesions in pancreatic solid masses. The aim of this prospective study was to evaluate the usefulness of IMP3 and p53 immunohistochemical staining in endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) samples for pancreatic solid masses. The study recruited 90 consecutive patients with pancreatic masses, including 62 pancreatic ductal adenocarcinomas (PDACs), 11 benign tumors, and 17 other tumors, who underwent EUS-FNA, and conducted IMP3 and p53 immunohistochemical staining. The main outcome measurement was improved diagnostic utility using IMP3 and p53 immunohistochemical staining. IMP3 and p53 expressions were detected in 60.8% and 49.4% of malignant lesions, 69.4% and 58.1% of PDACs, and 0% of benign lesions, respectively. In PDAC and benign tumors, the use of IMP3 and/or p53 immunostaining increased the sensitivity of cytohistological analysis from 88.7 to 93.5%, although the difference was not statistically significant. The sensitivity of histological analysis combined with that of IMP3 staining was 91.9%, which was significantly greater than that of histology alone (80.6%). The use of IMP3 and p53 immunohistochemical staining did not significantly improve the sensitivity of cytohistological analysis; however, IMP3 staining may be helpful for the histological analysis of malignant pancreatic tumors.

Reactivation of Multiple Fetal miRNAs in Lung Adenocarcinoma

MicroRNAs (miRNAs) play vital roles in the regulation of normal developmental pathways. However, cancer cells can co-opt these miRNAs, and the pathways that they regulate, to drive pro-tumourigenic phenotypes. Characterization of the miRNA transcriptomes of fetal organs is essential for identifying these oncofetal miRNAs, but it has been limited by fetal sample availability. As oncofetal miRNAs are absent from healthy adult lungs, they represent ideal targets for developing diagnostic and therapeutic strategies. We conducted small RNA sequencing of a rare collection of 25 human fetal lung (FL) samples and compared them to two independent cohorts (n = 140, n = 427), each comprised of adult non-neoplastic lung (ANL) and lung adenocarcinoma (LUAD) samples. We identified 13 oncofetal miRNAs that were expressed in FL and LUAD but not in ANL. These oncofetal miRNAs are potential biomarkers for LUAD detection (AUC = 0.963). Five of these miRNAs are derived from the imprinted C14MC miRNA cluster at the 14q32 locus, which has been associated with cancer development and abnormal fetal and placental development. Additionally, we observed the pulmonary expression of 44 previously unannotated miRNAs. The sequencing of these fetal lung samples also provides a baseline resource against which aberrant samples can be compared.

Optimal tissue sampling during ERCP and emerging molecular techniques for the differentiation of benign and malignant biliary strictures

Patients with cholangiocarcinoma have poor survival since the majority of patients are diagnosed at a stage precluding surgical resection, due to locally irresectable tumors and/or metastases. Optimization of diagnostic strategies, with a principal role for tissue diagnosis, is essential to detect cancers at an earlier stage amenable to curative treatment. Current barriers for a tissue diagnosis include both insufficient tissue sampling and a difficult cyto- or histopathological assessment. During endoscopic retrograde cholangiopancreatography, optimal brush sampling includes obtaining more than one brush within an individual patient to increase its diagnostic value. Currently, no significant increase of the diagnostic accuracy for the new cytology brush devices aiming to enhance the cellularity of brushings versus standard biliary brush devices has been demonstrated. Peroral cholangioscopy with bile duct biopsies appears to be a valuable tool in the diagnostic work-up of indeterminate biliary strictures, and may overcome current technical difficulties of fluoroscopic-guided biopsies. Over the past years, molecular techniques to detect chromosomal instability, mutations and methylation profiling of tumors have revolutionized, and implementation of these techniques on biliary tissue during diagnostic work-up of biliary strictures may be awaited in the near future. Fluorescence in situ hybridization has already been implemented in routine diagnostic evaluation of biliary strictures in several centers. Next-generation sequencing is promising for standard diagnostic care in biliary strictures, and recent studies have shown adequate detection of prevalent genomic alterations in KRAS, TP53, CDKN2A, SMAD4, PIK3CA, and GNAS on biliary brush material. Detection of DNA methylation of tumor suppressor genes and microRNAs may evolve over the coming years to a valuable diagnostic tool for cholangiocarcinoma. This review summarizes optimal strategies for biliary tissue sampling during endoscopic retrograde cholangiopancreatography and focuses on the evolving molecular techniques on biliary tissue to improve the differentiation of benign and malignant biliary strictures.

mAb Das-1 identifies pancreatic ductal adenocarcinoma and high-grade pancreatic intraepithelial neoplasia with high accuracy

Pancreatic intraepithelial neoplasia (PanIN) is a microscopic precursor lesion to pancreatic ductal adenocarcinoma (PDAC); however, there are few biomarkers that segregate high-grade PanIN/PDAC from low-grade PanIN lesions. mAb Das-1 is a monoclonal antibody against a colonic epithelial antigen that is reactive to premalignant conditions of the upper gastrointestinal tract including Barrett's esophagus, incomplete-type gastric intestinal metaplasia, and intraductal papillary mucinous neoplasm of the pancreas at high risk of malignancy. We sought to examine a role for Das-1 expression in differentiating high-grade PanIN/PDAC from low-grade PanIN lesions. We examined surgical specimens from 86 patients and 2 autopsied pancreata (74 with and 14 without PDAC) with 107 distinct PanIN lesions, 74 PDAC cases, and 32 associated lymph node metastases, with internal controls of normal pancreatic ducts observed in 56 cases. All of the normal pancreatic duct controls (0/56) and low-grade PanIN (0/95) lesions were nonreactive to Das-1. Das-1 expression among high-grade PanIN (7/12, 58%), PDAC (55/74, 74%), and lymph node metastasis (21/32, 66%) cases was significantly higher (p < 0.0001). Clinicopathologically, Das-1 reactivity was significantly correlated with nodal metastasis (p = 0.021). Overall, the sensitivity, specificity, and accuracy of Das-1 in segregating high-grade PanIN/PDAC from low-grade PanIN lesions and normal ducts were 72%, 100%, and 90%, respectively. Thus, mAb Das-1 reacts with high specificity with high-grade PanIN and PDAC and may help in preoperative diagnosis and/or clinical risk stratification.

IGF2BP3 Expression Correlates With Poor Prognosis in Esophageal Squamous Cell Carcinoma

BACKGROUND

Insulin-like growth factor-II mRNA binding protein 3 (IGF2BP3) is an oncofetal RNA-binding protein normally involved in cell growth and migration during the early stages of embryogenesis. However, it is also expressed in various cancers, and the relationship between IGF2BP3 and the clinicopathological features and prognosis of esophageal squamous cell carcinoma patients is not fully understood. Our aim in this study was to determine whether IGF2BP3 expression status correlates with prognosis in patients with advanced thoracic esophageal squamous cell carcinoma.

METHODS

The IGF2BP3 expression statuses of 177 patients treated with esophagectomy without preoperative therapy were evaluated immunohistochemically using tissue microarray analysis. The relationships between IGF2BP3 expression status and clinicopathological features and survival were then assessed using appropriate statistics.

RESULTS

Among 177 esophageal tumors, 122 (68.9%) expressed high levels of IGF2BP3. In patients undergoing surgery alone, IGF2BP3-high expression was significantly associated with a poorer prognosis. By contrast, there were no significant associations between IGF2BP3 expression and clinicopathological features or outcomes in patients treated with surgery plus postoperative adjuvant chemotherapy.

CONCLUSIONS

IGF2BP3 positivity in advanced thoracic esophageal squamous cell carcinoma is associated with adverse clinical outcomes in patients treated with surgery alone.

IMP3 is a biomarker for non-muscle-invasive urothelial carcinoma of the bladder associated with an aggressive phenotype

Bladder cancer is one of the most common malignancies of urinary tract. The current study aimed to investigate the role of insulin-like growth factor II messenger RNA binding protein 3 (IMP3) expression in the prognostic evaluation of non-muscle- invasive urothelial carcinoma of the bladder.Immunohistochemistry (IHC) was carried out to examine IMP3 protein expression in specimens from 183 cases of non-muscle-invasive urothelial carcinoma, 20 cases of muscle-invasive urothelial carcinoma and 20 benign tissues adjacent to cancer tissue.The expression of IMP3 was not detected in the adjacent benign tissues. The expression intensity of IMP3 in muscle-invasive samples was significantly higher than that in non-muscle-invasive urothelial carcinoma specimens (P = .008). IMP3 expression was significantly related with advanced tumor stage (P < .001), advanced tumor grade (P = .004), and tumor recurrence (P < .001) in non-muscle-invasive urothelial carcinomas. Kaplan-Meier analysis showed that IMP3-positive patients had much lower disease-free (P < .001), progression-free (P = .002) and metastasis-free (P = .019) survival rates compared with those with IMP3-negative tumors. By multivariable Cox analysis, we also found that IMP3 expression in non-muscle- invasive urothelial carcinomas proved to be an independent unfavorable prognostic factor of disease-free survival (HR: 2.52; 95% CI, 1.39-4.56; P = .002), progression- free survival (HR: 5.19; 95% CI, 1.54-17.46; P = .008) and metastasis-free survival (HR: 4.87; 95% CI, 1.08-22.02; P = .040).Our results demonstrate that the expression of IMP3 in non-muscle- invasive bladder cancer can serve as an independent predictor that will help recognize the subgroup of patients with a high ability to relapse, progress, and metastasize and who might get the maximum benefit from an early and more aggressive treatment strategy.

The Insulin-Like Growth Factor 2 mRNA Binding Protein IMP2/IGF2BP2 is Overexpressed and Correlates with Poor Survival in Pancreatic Cancer

The insulin-like growth factor 2 (IGF2) mRNA binding protein IMP2 (IGF2BP2) is an oncogenic protein known to be overexpressed in different tumor types. Pancreatic cancer is a very lethal cancer that requires early diagnosis and new treatment options. The aim of our study was to investigate the role of IMP2 in the initiation and progression of pancreatic ductal adenocarcinoma (PDAC). IMP2 was significantly overexpressed in a human precursor (PanIN) lesions suggesting IMP2 as a marker for early stages of PDAC. In a PDAC cohort of matched normal and tumor samples IMP2 showed overexpression in tumor tissues compared with normal pancreatic tissue. Strict correlation analysis (threshold R² > 0.75) revealed 22 genes highly positively and 9 genes highly negatively correlating with IMP2. Besides genes involved in the inhibition of apoptosis (Bcl-XL), especially factors involved in ubiquitination were strongly correlated with IMP2 expression: SMURF1 and FBXO45. Moreover, protein kinase C (PKC) signaling pathway was distinctly affected: DXS1179E encoding PKC iota, PKC substrate PLEK2, and inositol triphosphate receptor IP3R3 were positively correlated with IMP2 expression. Besides tumor initiation, IMP2 also seemed to have an impact on tumor progression. TGF-β treatment of Panc-1 pancreatic cancer cells to induce epithelial-mesenchymal transition (EMT) was accompanied by increased IMP2 expression. EMT is important for cancer cells to gain migratory and invasive potential, which is essential for metastasis. Concordantly, circulating tumor cells showed higher IMP2 levels as compared with normal tissue from tumor origin and with normal hematological cells. Accordingly, IMP2 protein levels correlated with poor survival. In conclusion, as IMP2 seems to promote tumor progression of PDAC, it might be an interesting diagnostic and prognostic marker as well as a novel target for the treatment of PDAC.

Addition of IMP3 to L1CAM for discrimination between low- and high-grade endometrial carcinomas: a European Network for Individualised Treatment of Endometrial Cancer collaboration study

Discrimination between low- and high-grade endometrial carcinomas (ECs) is clinically relevant but can be challenging for pathologists, with moderate interobserver agreement. Insulin-like growth factor-II mRNA-binding protein 3 (IMP3) is an oncofoetal protein that is associated with nonendometrioid endometrial carcinomas but has been limited studied in endometrioid carcinomas. The aim of this study is to investigate the diagnostic and prognostic value of IMP3 in the discrimination between low- and high-grade ECs and its added value to L1CAM. IMP3 and L1CAM expression was assessed in tumors from 378 patients treated for EC at 1 of 9 participating European Network for Individualised Treatment of Endometrial Cancer centers. IMP3 was expressed in 24.6% of the tumors. In general, IMP3 was more homogeneously expressed than L1CAM. IMP3 expression was significantly associated with advanced stage, nonendometrioid histology, grade 3 tumors, deep myometrial invasion, lymphovascular space invasion, distant recurrences, overall mortality, and disease-related mortality. Simultaneous absence of IMP3 and L1CAM expression showed the highest accuracy for identifying low-grade carcinomas (area under the curve 0.766), whereas simultaneous expression of IMP3 and L1CAM was strongly associated with high-grade carcinomas (odds ratio 19.7; 95% confidence interval 9.2-42.2). Even within endometrioid carcinomas, this combination remained superior to IMP3 and L1CAM alone (odds ratio 8.6; 95% confidence interval 3.4-21.9). In conclusion, IMP3 has good diagnostic value and together with L1CAM represents the optimal combination of diagnostic markers for discrimination between low- and high-grade ECs compared to IMP3 and L1CAM alone. Because of the homogenous expression of IMP3, this marker might be valuable in preoperative biopsies when compared to the more patchy L1CAM expression.

Ancillary Techniques in Cytologic Specimens Obtained from Solid Lesions of the Pancreas: A Review

Advanced methods of molecular characterization have elucidated the genetic, epigenetic, and proteomic alterations associated with the broad spectrum of pancreatic disease, particularly neoplasia. Next-generation sequencing, in particular, has revealed the genomic diversity among pancreatic ductal adenocarcinoma, neuroendocrine and acinar tumors, solid pseudopapillary neoplasm, and other pancreatico-biliary neoplasms. Differentiating these entities from one another by morphologic analysis alone may be challenging, especially when examining the small quantities of diagnostic material inherent to cytologic specimens. In order to enhance the sensitivity and specificity of pancreatic cytomorphology, multiple diagnostic, prognostic, and predictive ancillary tests have been and continue to be developed. Although a great number of such tests have been developed for evaluation of specimens collected from cystic lesions and strictures, ancillary techniques also play a significant role in the evaluation of cytologic specimens obtained from solid lesions of the pancreas. Furthermore, while some tests have been developed to differentiate diagnostic entities from one another, others have been developed to simply identify dysplasia and malignancy. Ancillary studies are particularly important in the subset of cases for which cytomorphologic analysis provides a result that is equivocal or insufficient to guide clinical management. Selection of appropriate ancillary testing modalities requires familiarity with both their methodology and the molecular basis of the pancreatic diseases for which testing is being performed.

High-grade ovarian serous carcinomas: Significant correlation of histologic patterns with IMP3 and E-Cadherin predicting disease recurrence and survival

Most high-grade serous carcinomas (HGSC) of the ovary are advanced stage tumors with early recurrences. However, some tumors do not recur and have a better survival. We identified such cases of HGSC and compared those with the cases that recurred and assessed the relationship between patterns of invasion (intracystic, IC; micropapillary, MP; nonpapillary, NP) with IMP3 and E-Cadherin expression, and evaluated their predictive role in recurrence and survival. The study comprised of seventeen tumors recurred within 18 months of follow-up and 14 cases that did not recur with a minimum follow-up of 49 months. 73% tumors with predominantly MP pattern recurred, while only 27% of non-recurrent tumors showed this pattern. In contrast, predominant NP and IC patterns were seen in 71% of the non-recurrent and in 35% of recurrent tumors. 67.7% tumors expressed IMP3 and all cases expressed E-Cadherin. The tumors with a higher percentage of destructive invasion showed higher IMP3 positivity and greater chances of recurrence, whereas tumors with higher percentage of pushing invasion showed lower IMP3 positivity and lesser chances of recurrence (p = 0.02). IMP3-negative tumors had lower odds of recurrence than IMP3-positive ones (p = 0.01). The patients with negative IMP3 staining had a significantly higher OS than those with IMP3 positive tumors (p = 0.01), regardless of the histologic patterns. Also, reduction in E-Cadherin staining in the metastatic site led to poor DFS (p = 0.016) and OS (p = 0.006). IMP3 may serve as a useful prognostic marker that can stratify patients of advanced stage, high-grade serous carcinomas into two distinct subsets: majority with early recurrence with an infiltrative pattern of invasion and IMP3 positivity particularly in the MP areas; and a smaller subset that do not show early recurrence having pushing borders and are IMP3 negative. Also, E-Cadherin showed significant decrease in expression in the metastatic site of the recurrent cases.

Immunohistochemical staining for S100P, SMAD4, and IMP3 on cell block preparations is sensitive and highly specific for pancreatic ductal adenocarcinoma

INTRODUCTION

The diagnosis of pancreatic ductal adenocarcinoma (PDA) on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) material is often challenging. An immunohistochemical (IHC) panel may help establish the diagnosis of PDA in cases limited by sample size or ambiguous cytology. S100P, IMP3, and SMAD4 are 3 IHC markers that have shown promise as individual markers for PDA that have never been tested together as a panel. In this study, we evaluated the individual and combined efficacy of S100P, IMP3, and SMAD4 for the detection of PDA.

MATERIALS AND METHODS

S100P, IMP3, and SMAD4 IHC staining was performed on cell blocks (CBs) procured from pancreatic EUS-FNA procedures. The cohort included CBs that were diagnostic for PDA (n = 35), suspicious but nondiagnostic for PDA (n = 2), as well as CBs with benign pancreatic ductal epithelium (n = 12) and benign reactive pancreatic ductal epithelium (n = 18). A positive result for IMP3 and S100P was defined as moderate or strong staining of >10% of ductal cells. Complete lack of SMAD4 nuclear staining was considered a positive result-any nuclear SMAD4 staining was considered a negative result.

RESULTS

Two and 3 IHC marker panels were almost always more specific than individual IHC markers. Positivity for at least 2 of 3 IHC markers was a sensitive (91.89%) and highly specific (100%) marker of PDA.

CONCLUSIONS

The 3 IHC marker panel composed of S100P, IMP3, and SMAD4 is highly specific for PDA. Future studies should evaluate efficacy in a cohort with more atypical and suspicious cases.

A quarter century of EUS-FNA: Progress, milestones, and future directions

Tissue acquisition using EUS has considerably evolved since the first EUS-FNA was reported 25 years ago. Its introduction was an important breakthrough in the endoscopic field. EUS-FNA has now become a part of the diagnostic and staging algorithm for the evaluation of benign and malignant diseases of the gastrointestinal tract and of the organs in its proximity, including lung diseases. This review aims to present the history of EUS-FNA development and to provide a perspective on the recent developments in procedural techniques and needle technologies that have significantly extended the role of EUS and its clinical applications. There is a bright future ahead for EUS-FNA in the years to come as extensive research is conducted in this field and various technologies are continuously implemented into clinical practice.

IMP3 Immunoreactivity is More Sensitive Than AMACR in Detecting Dysplastic Epithelium and Early Adenocarcinoma in Barrett Esophagus

CONTEXT

α-methylacyl coenzyme A racemase (AMACR) and insulin-like growth factor-II mRNA-binding protein 3 (IMP3) are 2 markers helpful in detecting difficult cases of dysplasia in Barrett esophagus (BE). However, no comparison studies have been performed to assess their performance in the same patient population.

OBJECTIVES

The aim of our study was to compare the immunohistochemical expression of IMP3 and AMACR in dysplastic lesions and early adenocarcinoma (EAC) arising in BE and evaluate their sensitivity and specificity.

DESIGN

A total of 98 cases [BE negative for dysplasia, n=24; indefinite for dysplasia (BE-IND), n=18; low-grade dysplasia (LGD), n=24; high-grade dysplasia (HGD), n=16; and EAC, n=16] were immunostained for AMACR and IMP3 and evaluated for the degree, the extent, and the intensity of staining.

RESULTS

No immunoreactivity for AMACR or IMP3 was observed in all 24 cases of BE negative for dyplasia. One of 18 (5.5%) cases of BE-IND was positive for IMP3, but all were negative for AMACR. AMACR and IMP3 were positive in 16.7% versus 41.7 % of the cases with BE-LGD, 25% versus 62.5% of BE-HGD, and 62.5% versus 93.7% of EAC, respectively. The sensitivity of AMACR and IMP3 for the detection of dysplasia in BE is 16.7% and 41.7% for LGD, 25% and 62.5% for HGD, and 62.5% and 93.7% in EAC, respectively. The specificity is 100% for both markers. In addition, a comparison of the intensity of reactivity shows a better result with IMP3 (36/98, 36.7%) than with AMACR (18/98, 18.4%) (P<0.001).

CONCLUSIONS

IMP3 has a similar specificity, but a better sensitivity, intensity, and extent of reactivity in comparison with AMACR, and may be used as an alternative to AMACR, in support of the diagnosis of BE-dysplasia and EAC.

Immunohistochemical analysis of IMP3 and p53 expression in endoscopic ultrasound-guided fine needle aspiration and resected specimens of pancreatic diseases

BACKGROUND

Insulin-like growth factor II messenger ribonucleic acid-binding protein 3 (IMP3) is a valuable marker that distinguishes malignant from benign lesions and predicts prognosis.

METHODS

First, we evaluated IMP3 expression in 77 resected specimens of pancreatic ductal adenocarcinoma (PDAC), intraductal papillary mucinous neoplasm (IPMN), and chronic pancreatitis (CP). Eleven PDAC patients preoperatively underwent endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Survival analysis of IMP3 and clinicopathological factors was performed. IMP3 and p53 expression was evaluated in another 127 EUS-FNA samples of solid pancreatic masses to compare the diagnostic value of routine and immunohistochemical staining.

RESULTS

IMP3 expression was detected in 72.3%, 50%, 20%, and 0% of PDAC, malignant IPMN, benign IPMN, and CP, respectively. Evaluation of IMP3 expression in EUS-FNA specimens coincided with that in resected specimens in 10 of 11. IMP3 expression correlated with tumor differentiation in PDAC samples (p = .006) and with poor prognosis through univariate analysis (p = .045). Tumor differentiation and lymph node metastasis were significantly associated with poor prognosis through multivariate analysis. In EUS-FNA specimens, the sensitivity, specificity, and accuracy of cytohistological analysis were 80.8%, 100%, and 85.0%, respectively. IMP3 and p53 expression were detected in 80.8% and 44.9% of malignant and 0% and 5% of benign lesions. Combined with IMP3 immunostaining, the sensitivity, specificity and accuracy of cytohistological analysis significantly increased to 87.9%, 100%, and 90.8% (p = .016), respectively. Meanwhile, p53 staining had no impact on the results.

CONCLUSIONS

IMP3 immunohistochemical staining can improve the diagnostic accuracy of EUS-FNA for malignant pancreatic tumors.

Diagnostic Value of S100p, IMP3, Maspin, and pVHL in the Differantial Diagnosis of Pancreatic Ductal Adenocarcinoma and Normal/chronic Pancreatitis in Fine Needle Aspiration Biopsy

Introduction:

Differentiation between pancreatic ductal adenocarcinoma (PDAC) from benign mimickers is a well-known problem in cytological materials. Recent studies incorporated biological markers into this question and some studies showed that expression of S100P, IMP3, and maspin as well as nonexpression of von Hippel-Lindau gene product (pVHL) were significantly correlated with PDAC. In this study, we aimed to investigate diagnostic value of maspin, IMP3, S100P, and pVHL immunostaining in fine needle aspiration biopsies (FNABs) of pancreatic lesions.

Materials and Method:

In all, 33 cases of FNAB cell blocks of PDAC and 34 cases of surgical non-neoplastic pancreas specimens which were retrieved from the archives slides from 2007 to 2011 were included in this study. All the cases were stained with maspin, IMP3, S100P, and pVHL. Expression patterns of markers were scored and compared with benign mimickers. Test performance of each antibody and possible antibody combinations were also evaluated.

Results:

The study was composed of 33 PDAC and 34 control cases (8 chronic pancreatitis, 3 mucinous cystic neoplasm, and 23 nontumoral pancreatic tissue of PDAC). Diagnostic sensitivity for malignancy in S100P, IMP3, and maspin was 84.8%, 81.8%, and 87.5%, respectively. Specificity of these three markers was 100%. Sensitivity and specificity of pVHL for detecting nontumoral pancreatic tissue were 100% and 81.8%, respectively. When maspin, IMP3, and S100P expression were used together as triple test, sensitivity was 62.5% and specificity 100%. However, when any two of each three markers were evaluated (triple test/dual response), sensitivity reached 93.8% and specificity 100%.

Conclusion:

We observed that dual response in triple test (positive staining with two of these three markers) of maspin, IMP3, and S100P immunocytochemistry is very sensitive and specific in differential diagnosis of PDA and non-neoplastic pancreatic lesions. pVHL may have an additional role, when triple assessment is not satisfactory.

Epithelial‑mesenchymal transition in colorectal carcinoma cells is mediated by DEK/IMP3

To investigate the inhibitory effects of DEK/insulin‑like growth factor II mRNA binding protein 3 (IMP3) on epithelial‑mesenchymal transition (EMT) in colorectal carcinoma cells. SW620 and SW480 cell lines were selected. DEK‑interfering lentivirus was transfected to knockdown DEK expression. Subsequently, MTT assays and flow cytometry were utilized to measure cell viability, and apoptosis, respectively. Cell invasion was detected using a Transwell assay. Quantitative polymerase chain reaction and western blot analysis were used to detect the expression of E‑cadherin, vimentin, and matrix metalloproteinase (MMP)‑9. Compared with the blank control, cells transfected with DEK‑interfering lentivirus demonstrated a remarkable reduction in cell viability (P<0.05). The apoptotic rate in the DEK‑interfering lentivirus group was significantly enhanced compared with the blank control group (P<0.05). In the DEK‑interfering lentivirus group, the expression of E‑cadherin was significantly elevated (P<0.05), while the expression of vimentin and MMP‑9 were significantly reduced in both cell lines (P<0.05). The results of the present study demonstrated that EMT of colorectal carcinoma cells was partially mediated by DEK, which likely affected the invasive ability of colorectal carcinoma cells. In addition, cell proliferation and apoptosis were susceptible to DEK silencing. The current study has provided experimental evidence for the treatment of colorectal carcinoma using DEK silencing.

IMP3 overexpression occurs in various important cancer types and is linked to aggressive tumor features: A tissue microarray study on 8,877 human cancers and normal tissues

IMP3 is an RNA binding protein required for ribosomal RNA processing, which has been suggested to be a prognostic marker in a large variety of human types of cancer. However, available data on the prevalence of IMP3 expression are largely discrepant. To systematically investigate the epidemiology and clinical relevance of IMP3 expression in human cancers we employed a two-step tissue microarrays (TMAs) approach. First, a normal tissue TMA and a multi-tumor TMA were analyzed for immunohistochemically detectable expression of IMP3 in 76 different normal tissue types and 3889 cancer samples from 95 different tumor categories. In a second step, we searched for associations between IMP3 expression and tumor phenotype and patient prognosis in TMAs containing 697 urinary bladder cancers, 1711 colon cancers, 343 esophageal adenocarcinomas, 251 esophageal squamous cell cancers, 673 lung cancers), 275 pancreatic cancers and 230 stomach cancers. In normal tissues, unequivocal IMP3 expression was found in placenta, lymphocytes and some types of glandular epithelial cells. In cancers, at least one case with weak expression could be found in 76 out of 95 (80%) different tumor types and 64 entities (67%) had at least one tumor with strong positivity. IMP3 expression was most frequently found in testicular cancer (including 71% seminomas and 96% non-seminomas), neuroblastoma (88%), and squamous cell cancer of various origins. Significant associations were found between IMP3 and adverse tumor features in esophageal adenocarcinomas and cancers of the urinary bladder, lung, stomach, and pancreas. In summary, IMP3 was frequently expressed in many different tumor types, and was typically associated with aggressive tumor features.

Practical Immunohistochemistry in Neoplastic Pathology of the Gastrointestinal Tract, Liver, Biliary Tract, and Pancreas

CONTEXT

- Immunomarkers with diagnostic, therapeutic, or prognostic values have been increasingly used to maximize the benefits of clinical management of patients with neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas.

OBJECTIVES

- To review the characteristics of immunomarkers that are commonly used in surgical pathology practice for neoplasms of the gastrointestinal tract, liver, biliary tract, and pancreas, and to summarize the clinical usefulness of immunomarkers that have been discovered in recent years in these fields.

DATA SOURCES

- Data sources include literature review, authors' research data, and personal practice experience.

CONCLUSIONS

- Immunohistochemistry is an indispensable tool for the accurate diagnosis of neoplastic diseases of the gastrointestinal tract, liver, biliary tract, and pancreas. Useful immunomarkers are available to help distinguish malignant neoplasms from benign conditions, determine organ origins, and subclassify neoplasms that are morphologically and biologically heterogeneous. Specific immunomarkers are also available to help guide patient treatment and assess disease aggressiveness, which are keys to the success of personalized medicine. Pathologists will continue to play a critical role in the discovery, validation, and application of new biomarkers, which will ultimately improve patient care.

The H19-PEG10/IGF2BP3 axis promotes gastric cancer progression in patients with high lymph node ratios

We previously demonstrated that the lymph node ratio (LNR) is a prognostic factor associated with EGFR expression, among first priority genes amplified or overexpressed in cancer. Here, we investigated the associations between high LNR and second, third, and fourth priority genes. We performed mRNA expression microarray analysis of tumor tissue from patients with stage III gastric cancer and high or low LNRs. Candidate high LNR-associated genes were further evaluated in 39 patients with stage III gastric cancer. The functional relevance of these genes was evaluated in gastric cancer cell lines. We focused on five genes: H19,PEG10, IGF2BP3, CD177, and PGA3. H19 and PEG10 were confirmed as high LNR-associated genes. H19, PEG10, and IGF2BP3 were found to promote each other’s expression. Knocking down H19 or PEG10 using RNAi decreased cell proliferation, invasion, anchorage-independent growth, and chemoresistance. These genes had a mutual relationship in MKN7 cells. H19 knockdown decreased expression of epithelial-mesenchymal transition-associated genes in MKN74 cells to suppress transformation. Thus, H19 promotes epithelial-mesenchymal transition in gastric cancer and is a potential therapeutic target.

IGF2BP3 as a potential tissue marker for the diagnosis of esophageal high-grade intraepithelial neoplasia

Background

The clinical significance of insulin-like growth factor-II mRNA-binding protein-3 (IGF2BP3) in esophageal high-grade intraepithelial neoplasia (HGIN) is not clear. This study was designed to characterize the expression of IGF2BP3 in HGIN.

Patients and methods

IGF2BP3 expression was evaluated by Western blot analyses in 12 cases and by immunohistochemistry (IHC) in 112 cases. The associations between IGF2BP3 expression in HGIN and the clinicopathological parameters were examined.

Results

Moderate to strong IGF2BP3 expression was present in HGIN samples. Using IHC, it was found that IGF2BP3 was positive in 68 (60.71%) cases. Intense IHC of IGF2BP3 in HGIN was associated with a deeper lesion depth, and the lesion depth was the only predictor of the positive expression of IGF2BP3.

Conclusion

Our results suggested that IGF2BP3 may be a supplementary tissue marker for preoperative diagnosis of HGIN.

IMPs: an RNA-binding protein family that provides a link between stem cell maintenance in normal development and cancer

This review by Degrauwe et al. summarizes our current understanding of the functions of IMPs during normal development and focuses on a series of recent observations that have provided new insight into how their physiological functions enable IMPs to play a potentially key role in cancer stem cell maintenance and tumor growth.

IMPs, also known as insulin-like growth factor 2 (IGF2) messenger RNA (mRNA)-binding proteins (IGF2BPs), are highly conserved oncofetal RNA-binding proteins (RBPs) that regulate RNA processing at several levels, including localization, translation, and stability. Three mammalian IMP paralogs (IMP1–3) have been identified that are expressed in most organs during embryogenesis, where they are believed to play an important role in cell migration, metabolism, and stem cell renewal. Whereas some IMP2 expression is retained in several adult mouse organs, IMP1 and IMP3 are either absent or expressed at very low levels in most tissues after birth. However, all three paralogs can be re-expressed upon malignant transformation and are found in a broad range of cancer types where their expression often correlates with poor prognosis. IMPs appear to resume their physiological functions in malignant cells, which not only contribute to tumor progression but participate in the establishment and maintenance of tumor cell hierarchies. This review summarizes our current understanding of the functions of IMPs during normal development and focuses on a series of recent observations that have provided new insight into how their physiological functions enable IMPs to play a potentially key role in cancer stem cell maintenance and tumor growth.

IMP3 and p16 expression in squamous cell carcinoma of the head and neck: A comparative immunohistochemical analysis

Expression of p16 has been established as a good surrogate marker for high-risk human papillomavirus (HPV) infection in oropharyngeal squamous cell carcinoma (OPSCC) patients, and it has been associated with an improved prognosis, irrespective of the actual HPV status. Conversely, the human insulin-like growth factor II mRNA binding protein 3 (IMP3) has been related to aggressiveness in several types of tumors. The aim of the present study was to investigate and compare p16 and IMP3 as markers of favorable and unfavorable behavior, respectively, in head and neck SCC (HNSCC), with particular reference to the HPV status. Both markers were analyzed by immunohistochemical analysis of 156 HNSCC samples originating from the oropharynx (n=81), oral cavity (n=44), larynx (n=15), hypopharynx (n=10) and nasopharynx (n=6). The HPV status was examined in a randomly selected representative subcohort (n=38) using polymerase chain reaction. Of the 156 HNSCC samples, 81 (51.9%) and 54 (34.6%) were positive for IMP3 and p16, respectively. IMP3 expression (P=0.022), p16 expression (P<0.001) and the combination of these markers (P<0.001) were significantly associated with tumor site. In particular, 69/81 (85%) OPSCC samples were positive for either one or both markers compared with 36/75 (48%) SCC samples from other sites. p16 expression was significantly associated with HPV infection (P=0.017) and a trend towards a negative association between IMP3 expression and HPV infection was observed (P=0.053). The results of the present study suggested that IMP3 and p16 are more frequently expressed in OPSCC compared with other HNSCCs. The prognostic impact of IMP3 on OPSCC remains to be investigated in a larger series with an extended follow-up period.

IMP3 contributes to poor prognosis of patients with metaplastic breast carcinoma: A clinicopathological study

Metaplastic breast carcinoma (MBC) is a rare type of tumor with heterogenous histological patterns. We investigated the immunohistochemical expression of IMP3, an oncofetal protein, in 31 MBC patients in association with histological subtypes and clinical outcomes. The cohort consisted of spindle cell carcinoma (SPC) (n=11), squamous cell carcinoma (SCC) (n=14), matrix-producing carcinoma (MPC) (n=4), carcinoma with osteocartilaginous elements (COC) (n=1), and low grade adenosquamous cell carcinoma (ASC) (n=1). IMP3 expression was identified in 7 cases of SPC (64%) and 6 patients of all the other subtypes (p=0.051). In comparison between IMP3 high (n=13) and low (n=18) groups, a large-sized tumor (≥4.0cm) was identified in 9 IMP3 high patients, and 14 IMP3 low patients had a small-sized tumor (p=0.01). High Ki67 positivity was detected in all of the IMP3 high patients and in 7 of the IMP3 low patients (p=0.002). During the follow-up period, 9 IMP3 high patients died, whereas 15 of the 18 IMP3 low patients remained alive (p=0.004). A univariate analysis revealed that IMP3 expression and tumor size were significantly associated with poor clinical outcomes (p=0.03 and <0.001, respectively). The IMP3 high group was likely to be associated with reduced overall survival compared to the IMP3 low group (p=0.06). These findings indicate that IMP3 may contribute to the aggressive behavior of MBC, and that this expression could potentially be a prognostic marker of MBC.

Investigating the prognostic value of KOC (K homology domain containing protein overexpressed in cancer) overexpression after curative intent resection of pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic adenocarcinoma (PDAC) is now the third leading cause of cancer mortality in the United States. More than 80% of patients present with distant metastasis precluding surgical eligibility. Even among patients with localized disease deemed eligible for surgical resection, the median survival is only 22.8 months due to high recurrence rates. Identification of a biomarker correlated with patient specific prognosis upon initial diagnosis can serve as a way to individualize treatment options.

METHODS

We performed a retrospective cohort study analyzing pathology of patients who underwent curative intent surgery for PDAC at Geisinger Medical Center from 1998-2011 to identify whether the expression of KOC can be predictive of patient specific prognosis. Tissue microarrays of specimens were assessed by immunohistochemistry.

RESULTS

A total of 62 patients are included. Comparisons between groups on overall survival (OS) and progression free survival (PFS) are estimated using the Kaplan-Meier method and the log-rank test. Each biomarker was represented as low and high expression by categorizing the expression score at <4+ or >4+, based on intensity and extent of cells stained. 40 deaths occurred in the sample. Distant metastasis and differentiation (well/moderate vs. poor) were related to OS (P=0.0120, P=0.0086). Twenty-nine patients progressed in their disease. High/low KOC expression were significantly related to PFS (P=0.0556). Patients with a high KOC expression were more than 2 times more likely to progress compared to those with a low KOC expression (HR =2.04; 95% CI: 0.97, 4.29).

CONCLUSIONS

Our data is suggestive of KOC being a useful prognostic biomarker for identifying those patients with PDAC who have a high risk for early progression and distant metastasis. Larger studies are needed to determine whether KOC can be a therapeutic target in the treatment of pancreatic cancer. Furthermore, considering high KOC expressers had a worse PFS than their counterparts, investigation regarding the use of KOC expression as a biomarker to preselect patients who may benefit most from neoadjuvant chemotherapy is warranted.

The role of S100P and IMP3 in the cytologic diagnosis of pancreatic adenocarcinoma

PURPOSE

The aim of this study was to assess the role of the two markers, S100P and IMP3, in differentiating between pancreatic ductal adenocarcinoma (PDA) and non-neoplastic pancreatic tissue in (fine needle aspiration cytology) FNAC.

PATIENTS AND METHODS

This is a retrospective study that included 72 cases presented with pancreatic mass, where endoscopic guided FNAC was taken from pancreatic lesions. The final histopathologic diagnosis was considered the gold standard. Cell blocks were stained with anti S100P, and IMP3. Nuclear immunoreactivity with or without cytoplasmic staining for the first marker, and cytoplasmic staining for the second marker was considered specific. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and total accuracy of the two markers, as well as the combined accuracy of both markers were calculated.

RESULTS

S100P achieved 96.4% sensitivity, 93.3% specificity, 98.2% PPV, 87.5% NPV and 95.8% total accuracy, while IMP3 achieved 91.2% sensitivity, 86.7% specificity, 96.2% PPV, 72.2% NPV and 90.3% total accuracy for PDA. Both markers showed a total combined accuracy of 89%. S100P showed strong and diffuse staining pattern in most of cases, while the staining pattern for IMP3 was moderate and focal in most of cases.

CONCLUSION

Both markers were sensitive and specific for diagnosis of PDA. The staining pattern for S100P was easier to evaluate than IMP3.

IMP3 Immunohistochemical Expression Remains Consistent Among All Grades of Gastrointestinal Neuroendocrine Tumors

Insulin-like growth factor-II messenger RNA-binding protein-3 (IMP3), is an oncofetal protein whose aberrant expression has previously been detected in multiple malignant neoplasms. Pulmonary neuroendocrine carcinomas demonstrate increased expression compared with pulmonary carcinoid tumors, but this relationship has not been studied in gastrointestinal neuroendocrine tumors (GINETs). This study examined IMP3 expression in GINETs, with a focus on correlation with established grading criteria. Fifty-four GINETs were immunohistochemically studied using a monoclonal antibody against IMP3. Using established World Health Organization criteria, the cases were stratified by grade and included 31 grade 1 neuroendocrine tumors (G1 GINETs), 15 grade 2 neuroendocrine tumors (G2 GINETs), and 8 neuroendocrine carcinomas (GINECs). The majority (51/54, 94.4%) of GINETs demonstrated IMP3 staining. Thirty cases (55.6%) showed IMP3 cytoplasmic/membranous staining in 60% or greater of tumor cells, with moderate to strong staining in nearly all of these cases (29/30; 96.7%). Of the remaining 24 cases, 3 cases showed no staining, whereas 17 (81%) demonstrated weak staining. When stratified by grade, there was no statistically significant difference in IMP3 staining among the 3 grades of GINETs; of the G1 GINETs, 14 (45.2%) demonstrated staining in at least 60% of tumor cells, compared with 10 (66.7%) G2 GINETs and 6 (75%) GINECs. Hindgut neoplasms of any grade were the most likely to show significant IMP3 staining. Unlike what has been demonstrated in neuroendocrine neoplasms in the lungs, GINETs appear to have a consistent IMP3 expression profile among all tumors grades, which may be reflective of their unique tumor biology.

The oncofetal protein IMP3 is an indicator of early recurrence and poor outcome in mucoepidermoid carcinoma of salivary glands

OBJECTIVE

Mucoepidermoid carcinoma (MEC) is the most common primary malignancy of the salivary glands. Insulin-like growth factor-II mRNA-binding protein-3 (IMP3) is an important prognostic factor in some cancers and a tool that differentiates between benign and malignant pancreatic lesions. This study aimed to identify a relationship between the expression of IMP3 and the outcome of salivary gland MEC, as well as to differentiate MEC from pleomorphic adenoma (PA).

METHODS

Tissue specimens from 70 cases of salivary gland MEC, 40 cases of PA, and 10 cases with normal salivary gland were examined immunohistochemically for IMP3. The association among the expression of IMP3, clinicopathological characteristics and patient's survival was assessed.

RESULTS

IMP3 was present in 51.4% of MEC but absent in PA and normal salivary gland tissues. IMP3 expression was associated with age > 60 years, submandibular gland tumors, tumor size > 4 cm, high-grade tumors, lymph node metastasis, involvement of surgical margins, perineural invasion, distant metastasis, advanced TNM stage, tumor relapse, and death ( P<0.05). Increased expression of IMP3, tumors of the submandibular gland, and lymph node metastasis were independent prognostic factors of -free survival (DFS). In addition, IMP3 was a strong predictor of overall survival (OS) together with distant metastasis and intermediate and high-grade tumors.

CONCLUSIONS

IMP3 expression is highly important in evaluating the outcome of MEC. IMP3 can be used to differentiate MEC from PA of salivary glands.

SIRT6 Suppresses Pancreatic Cancer through Control of Lin28b

Chromatin remodeling proteins are frequently dysregulated in human cancer, yet little is known about how they control tumorigenesis. Here, we uncover an epigenetic program mediated by the NAD(+)-dependent histone deacetylase Sirtuin 6 (SIRT6) that is critical for suppression of pancreatic ductal adenocarcinoma (PDAC), one of the most lethal malignancies. SIRT6 inactivation accelerates PDAC progression and metastasis via upregulation of Lin28b, a negative regulator of the let-7 microRNA. SIRT6 loss results in histone hyperacetylation at the Lin28b promoter, Myc recruitment, and pronounced induction of Lin28b and downstream let-7 target genes, HMGA2, IGF2BP1, and IGF2BP3. This epigenetic program defines a distinct subset with a poor prognosis, representing 30%-40% of human PDAC, characterized by reduced SIRT6 expression and an exquisite dependence on Lin28b for tumor growth. Thus, we identify SIRT6 as an important PDAC tumor suppressor and uncover the Lin28b pathway as a potential therapeutic target in a molecularly defined PDAC subset. PAPERCLIP.

Diagnostic value of IMP3 and mesothelin in differentiating pancreatic ductal adenocarcinoma from chronic pancreatitis

BACKGROUND

The discrimination between pancreatic ductal adenocarcinoma (PDA) and chronic pancreatitis may be confusing at both clinical and radiologic levels. So, the search for biomarkers able to distinguish both clinical conditions is of great interest.

AIM

This study was undertaken to assess the value of insulin-like growth factor II mRNA binding protein 3 (IMP3) and mesothelin to differentiate PDA from non-neoplastic/reactive pancreatic duct epithelium.

METHODS

Immunohistochemical staining for IMP3 and mesothelin was performed on 40 formalin-fixed, paraffin-embedded tissue sections of PDA, 20 biopsies of chronic pancreatitis and 10 normal pancreatic tissue obtained from tumor-free surgical margins. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy were calculated.

RESULTS

IMP3 immunoreactivity was observed in 34 of 40 (85%) cases of PDA. The staining reaction was moderate to strong in 30 (75%) cases and diffuse in 26 (65%) cases. Eighteen of 20 (90%) biopsies of chronic pancreatitis were negative for IMP3, while the other two cases (10%) showed weak and focal IMP3 immunoreactivity. On the other hand, mesothelin demonstrated positive immunoreactivity in 30 of 40 (75%) cases of PDA. The staining reaction was moderate to strong in 24 (60%) cases and diffuse in 22 (55%) cases. Sixteen of 20 (80%) biopsies of chronic pancreatitis were negative for mesothelin, while weak and focal mesothelin staining was detected in the other 4 cases. All normal pancreatic tissues were negative for IMP3 and mesothelin expression. IMP3 showed higher sensitivity (85%) and specificity (90%) than mesothelin (75% and 80%, respectively).

CONCLUSIONS

Our results showed that IMP3 immunostaining has a higher sensitivity and specificity than mesothelin for the diagnosis of PDA. IMP3 and mesothelin may be useful markers in distinguishing neoplastic from reactive lesions of the pancreas in instances where this is impossible by morphology alone in surgical pathology practice.

A study to improve the identification of pancreatobiliary adenocarcinoma utilizing fine-needle aspiration cytology and immunohistochemical application for KOC and S100P

INTRODUCTION

The identification of pancreatic adenocarcinoma by fine-needle aspiration (FNA) cytology is a difficult, yet critical, task. This study uses a panel of two immunohistochemical (IHC) markers, KOC and S100P, to augment the interpretation of pancreatic adenocarcinoma using cytopathology specimens and to compare these to corresponding surgical specimens.

MATERIALS AND METHODS

We retrospectively reviewed 33 surgical specimens with pancreatic adenocarcinoma and 33 corresponding, preceding FNA cytology specimens. IHC studies for KOC and S100P were performed on both the surgical specimens and cytology cell blocks. Three pathologists reviewed the staining intensity and amount of tumor cell staining within these blocks. The findings were then analyzed for sensitivity, specificity, and combined sensitivity and specificity for the 2 markers.

RESULTS

KOC performed similarly to S100P in sensitivity for surgical specimens (90.9% for both) and better for FNA specimens (92.3% versus 82.7%, respectively). The specificity of KOC was significantly better than S100P for surgical and FNA specimens (100% for KOC in both specimens versus 72.7% and 89.7% for S100P in both specimens, respectively). The combined sensitivity of the panel of KOC and S100P was 99.2% for surgical specimens and 98.7% for FNA specimens. The combined specificity was 72.7% for surgical specimens and 89.7% for FNA specimens.

CONCLUSIONS

We found using KOC and S100P on FNA cell block cytology specimens to be a useful adjunct for interpretation when an interpretation of atypical or suspicious for pancreatic ductal adenocarcinoma is being considered and there are atypical epithelial cell groups in the cell block.

Insulin-Like Growth Factor II mRNA-Binding Protein 3 (IMP3) as a Useful Immunohistochemical Marker for the Diagnosis of Adenocarcinoma of Small Intestine

The biological characteristics and roles of insulin-like growth factor II mRNA-binding protein 3 protein (IMP3) expression in small-intestinal adenocarcinoma were investigated. The value of IMP3 immunostaining in the diagnosis of small-intestinal epithelial lesions was also evaluated. Immunohistochemical expression of IMP3 in normal small-intestinal mucosa adjacent to adenoma and adenocarcinoma lesions, and inflamed duodenal and ileal mucosa was analyzed. Samples assessed were: duodenal ulcer (n=6), Crohn’s disease (n=5), low-grade small-intestinal adenoma (n=10), high-grade small-intestinal adenoma (n=13), small-intestinal adenocarcinoma (n=23), lymph node metastases (LNM; n=7), and preoperative biopsies of small-intestinal adenocarcinoma (n=6). Immunohistochemical expression of Ki-67 and p53 was also analyzed in adenoma and adenocarcinoma samples. IMP3 was not expressed in normal epithelium, but weakly expressed in reparative epithelium. Meanwhile, increased IMP3 expression was associated with a higher degree of dysplasia in adenomas, higher T classification, LNM, Ki-67 positivity, histological differentiation, and lower 5-year disease-free survival, but not p53 expression in adenocarcinoma. IMP3 expression appears to be a late event in the small-intestinal carcinogenesis. Assessing the IMP3 staining pattern can be useful in the diagnosis of small-intestinal epithelial lesions when used in conjunction with other histological criteria.

Overexpression of the RNA-binding proteins Lin28B and IGF2BP3 (IMP3) is associated with chemoresistance and poor disease outcome in ovarian cancer

Background:

RNA-binding proteins have an important role in messenger RNA (mRNA) regulation during tumour development and carcinogenesis. In the present study, we examined the insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs; hereafter refered to as IMPs) and Lin28 family expressions in epithelial ovarian carcinoma (EOC) patients and correlated their expression levels with the response to chemotherapy, hCTR1 expression and patient survival.

Methods:

Patients clinical information, real-time RT-PCR, immunohistochemistry, western blot, Transwell migration invasion assays, and cytotoxicity assays were used.

Results:

From 140 EOC patients, high expression of IMP3 or Lin28B was associated with poor survival, and women diagnosed at advanced stages with elevated IMP3 and Lin28B were at higher risk of developing chemoresistance. High IMP3 levels combined with high Lin28B levels significantly correlated with the poorest 5-year survival rates. Knockdown of IMP3 or Lin28B decreased cell proliferation, migration, and invasion, and increased the platinum sensitivity, but not taxol sensitivity, of ovarian cancer cells through increased expression of hCTR1, a copper transporter involved in platinum uptake. High expression of hCTR1 correlated with low expression of IMP3/Lin28B and better progression-free survival in advanced-stage EOC patients.

Conclusion:

Testing for a combination of elevated IMP3 and Lin28B levels could further facilitate the identification of a patient subgroup with the worst prognosis.

Expression of the cancer testis antigen IGF2BP3 in colorectal cancers; IGF2BP3 holds promise as a specific immunotherapy target

Introduction

IGF2BP3 (IMP3) is a mRNA binding protein that regulates IGF2 translation and function during embryogenesis. Because IGF2BP3 is undetectable in adult human tissues except the testis, and increased IGF2BP3 expression has been noted in several cancers, it is considered a cancer testis (CT) protein. IGF2BP3 mRNA expression in colorectal cancers (CRC) has not been well studied. This study's aim was to quantitatively assess IGF2BP3 mRNA expression in CRC and, thus, determine if IGF2BP3 has potential as a vaccine target.

Method

Data were collected prospectively from CRC patients in an IRB-approved tissue and data bank. Total RNA was isolated and purified from tumor and normal colonic tissue samples and cDNA synthesized. IGF2BP3 expression was analyzed by quantitative PCR (QPCR). Expression levels of IGF2BP3 in tumors and testis were determined and compared. Tumors with levels greater than 0.1% or more of the testis levels were considered positive. Analysis of IGF2BP3 protein expression by immunohistochemistry (IHC) in tumor and normal tissues was also performed.

Results

A total of 84 paired tumor and normal tissue specimens were assessed from patients with Stage 2 and 3 CRC; 43% of tumors had IGF2BP3 mRNA expression levels greater than 0.1 % of that of testis and were considered positive. The median tumor expression level was higher in women (p=0.042). No correlation was found between IGF2BP3 mRNA expression and tumor stage or lymph node involvement. IHC was carried out on paired tumor and normal tissue sections from 46 patients; IGF2BP3 staining was noted in 50% of the tumor sections and in 5% of the normal tissue sections.

Discussion

IGF2BP3 mRNA was over expressed in 43% of the tumors whereas the protein was noted in 50% of samples. No correlation between mRNA expression and disease severity was noted. This protein holds promise as a vaccine target, however, a larger study that assesses a more diverse population of patients (Stage 1-4) as well as a study of preoperative serum samples for auto-antibodies to IGF2BP3 are needed to pursue this concept.

IMP3 expression in serous tumors of the ovary

Insulin-like growth factor II mRNA-binding protein (IMP3) is an oncofetal protein involved in embryogenesis, which is expressed in a variety of malignant neoplasms. It is rarely expressed in normal adult tissue and benign tumors. The aim of this study was to evaluate the expression of IMP3 in benign and malignant serous tumors of the ovary. Seventy-nine ovarian tumors were examined for IMP3 expression by immunohistochemical analysis, comprising 16 benign serous tumors, 19 borderline serous tumors, and 44 serous carcinomas. Positive staining was defined as brown staining in the cytoplasm. Negative staining was defined as absent staining or staining of <5% of tumor cells. The intensity of staining (weak, moderate, and strong) and percentage (0% to 100%) of neoplastic cells staining positive for cytoplasmic IMP3 staining were recorded in each case. Moderate to strong cytoplasmic staining for IMP3 was observed in 30 of 44 (68%) serous carcinomas of the ovary; in contrast, <5% of the borderline and benign serous tumors expressed IMP3 ranging from weak to strong cytoplasmic staining. Statistically, the difference in IMP3 expression between these groups of tumors was highly significant (P<0.0001). Our findings demonstrate moderate to strong expression of IMP3 in the majority of ovarian serous carcinomas as compared with benign/borderline serous tumors, which demonstrated weak to strong expression in a small minority (<5%) of the tumors. Thus, IMP3 may be a useful adjunctive tool in the pathologic evaluation of ovarian serous tumors.

IGF2BP3-mediated translation in cell protrusions promotes cell invasiveness and metastasis of pancreatic cancer

Pancreatic cancers are aggressive because they are highly invasive and highly metastatic; moreover, effective treatments for aggressive pancreatic cancers are lacking. Here, we report that IGF2BP3 promoted the invasiveness and metastasis of pancreatic cancers through locally translated IGF2BP3-bound transcripts. In neural cells, transcripts sorted into cytoplasmic RNA granules are transported to dendrites and translated in these dendrites, thereby mediating long-term synaptic plasticity; however, such cytoplasmic RNA granules are not known to contribute to the progression of pancreatic cancer. We show evidence that IGF2BP3 and IGF2BP3-bound transcripts are localized in cytoplasmic RNA granules that accumulate in membrane protrusions of pancreatic cancer cells. Specific IGF2BP3-bound transcripts—ARF6 and ARHGEF4—that are preferentially translated in membrane protrusions induce further formation of membrane protrusions; consequently, IGF2BP3 promotes cell invasiveness and tumor metastasis. Our results provide insight into the link between regulation of localized translation in cell protrusions and the invasiveness and metastasis of pancreatic cancers. New therapies that prevent local translation in cell protrusions may hold significant clinical promise.

Utility of immunohistochemistry in the pancreatobiliary tract

CONTEXT

Immunohistochemistry has become a useful ancillary study in the identification and classification of pancreatic neoplasms. The diagnostic accuracy has been significantly improved because of the continuous discoveries of tumor-associated biomarkers and the development of effective immunohistochemical panels.

OBJECTIVES

To identify and classify pancreatic neoplasms by immunohistochemistry.

DATA SOURCES

Literature review and authors' research data and personal practice experience were used.

CONCLUSIONS

To better guide therapeutic decisions and predict the prognostic outcome, it is crucial to make an accurate diagnosis of a pancreatic neoplasm. Application of appropriate immunohistochemical panels enables pathologists to differentiate pancreaticobiliary adenocarcinomas from reactive conditions and to identify rare types of pancreatic neoplasms. Knowing the utilities and pitfalls of each tumor-associated biomarker is essential to avoiding a potential diagnostic error because an absolutely cancer-specific biomarker does not exist. This article reviews frequently used tumor-associated biomarkers, provides lists of effective immunohistochemical panels, and recommends a diagnostic algorithm as a standard approach to pancreatic neoplasms.