Expression and prognostic significance of the polymeric immunoglobulin receptor in esophageal and gastric adenocarcinoma

The prognostic and potentially immunomodulatory role of cartilage oligomeric matrix protein in patients with gastric and esophageal adenocarcinoma

BACKGROUND

Cartilage oligomeric matrix protein (COMP) is a novel regulator of the tumor microenvironment. Studies in colon cancer and pancreatobiliary adenocarcinoma have revealed COMP expression to be associated with decreased infiltration of immune cells in the tumor microenvironment. Herein, the expression of COMP was investigated in gastric and esophageal adenocarcinoma with particular reference to its the relationship with the immune microenvironment.

METHODS

COMP expression was evaluated in tissue microarrays representing primary tumors from 159 patients with chemo- and radiotherapy naïve esophageal and gastric adenocarcinoma and 67 matched samples of lymph node metastases using immunohistochemistry. Additionally, collagen fibers were stained with Sirius Red and evaluated with the FIJI macro TWOMBLI algorithm.

RESULTS

The expression of COMP in cancer cells in the entire cohort was associated with shorter overall survival (OS) (p = 0.013) and recurrence-free survival (RFS) (p = 0.029), while COMP expression in the stroma was correlated with shorter RFS (p = 0.042). Similar correlations were found for patients with gastric adenocarcinoma, whereas COMP expression was not prognostic in esophageal adenocarcinoma. Further, in the entire cohort, the expression of COMP in the stroma was correlated with exclusion of different populations of immune cells (CD8+, CD3+, FoxP3+, CD20+) from the tumor microenvironment. Finally, higher density and alignment of collagen fibers were correlated with the expression of COMP in the stroma.

CONCLUSIONS

Expression of COMP in gastric and esophageal adenocarcinoma was correlated with shorter OS and RFS. A reduced number of immune cells infiltrated the tumor microenvironment when COMP expression was detected. This phenomenon could be attributed to the denser collagen deposits, a hallmark of tumor fibrosis observed in COMP-expressing tumors.

Advanced esophageal cancer with bone metastases: Prognostic biomarkers and palliative treatment

Esophageal cancer (EC) is a common and devastating tumor of the upper digestive tract. Unfortunately, by the time any symptoms have manifested, the disease has often progressed to an advanced stage and is accompanied by macro- and micrometastases, including in the bones. The treatment of esophageal cancer with bone metastases remains clinically challenging, given the poor prognosis associated with this condition. Effective prognostic biomarkers can help medical staff choose the appropriate operation and treatment plan, that is for most beneficial for making patients. Current treatments for esophageal cancer with bone metastases include pain-relieving drugs, surgical therapy, radiotherapy (RT), chemotherapy (CT, including molecular-targeted drug therapy), endocrine therapy (ET), bisphosphonates (BPs) and interventional therapy. Of these robust measures, radiotherapy has emerged as a particularly promising therapy for bone metastases from esophageal cancer. Substantial progress has been made in radiation therapy techniques since the discovery of X-rays by Roentgen in 1895. In its palliative capacity, the key goals of radiotherapy are to relieve the patients' bone pain and debilitate effects, including relieving spinal cord compression, correcting the spinal deformity and restoring spinal stability. However, it is worth mentioning that RT for esophageal cancer has various side effects. Currently, the available studies focused exclusively on radiotherapy for ECBM are too small to draw any definitive conclusions, and each of these studies has significant limitations. In this review, in addition to the epidemiology described at the beginning, we will explore the current prognostic biomarkers and radiotherapy for esophageal cancer, with a particular focus on those with bone metastases.

Polymeric immunoglobulin receptor (pIgR) in cancer

BACKGROUND

The polymeric immunoglobulin receptor (pIgR) is a transmembrane transporter of polymeric IgA through the intestinal epithelium. Its overexpression has been reported in several cancers, but its role as a diagnostic and prognostic biomarker of oncogenesis is currently unclear.

METHOD

A literature search was conducted to summarize the functions of pIgR, its expression levels, and its clinical implications.

RESULTS

pIgR expression has previously been investigated by proteomic analysis, RNA sequencing, and tissue microarray at the level of both RNA and protein in various cancers including pancreatic, esophageal, gastric, lung, and liver. However, studies have reported inconsistent results on how pIgR levels affect clinical outcomes such as survival rate and chemotherapy resistance. Possible explanations include pIgR mRNA levels being minimally correlated with the rate of downstream pIgR protein synthesis, and the diversity of antibodies used in immunohistochemistry studies further magnifying this ambiguity. In ovarian cancer cells, the transcytosis of IgA accompanied a series of transcriptional changes in intracellular inflammatory pathways that inhibit the progression of cancer, including the upregulation of IFN-gamma and downregulation of tumor-promoting ephrins. These findings suggest that both the levels of pIgR and secreted IgA from tumor-infiltrating B cells affect clinical outcomes.

CONCLUSION

Overall, no direct correlation was observed between the levels of pIgR inside tumor tissue and the clinical features in cancer patients. Measuring pIgR protein levels with a more specific and possibly chemically defined antibody, along with tumoral IgA, is a potential solution to better understand the pathways and consequences of pIgR overexpression in cancer cells.

Expression of polymeric immunoglobulin receptor (PIGR) and the effect of PIGR overexpression on breast cancer cells

Polymeric immunoglobulin receptor (PIGR) has a major role in mucosal immunity as a transporter of polymeric immunoglobulin across the epithelial cells. The aim of this study was to determine the effect of PIGR on cellular behaviours and chemo-sensitivity of MCF7 and MDA-MB468 breast cancer cell lines. Basal levels of PIGR mRNA and protein expression in MCF7 and MDA-MB468 cells were evaluated by real time quantitative polymerase chain reaction and Western blotting, respectively. MCF7/PIGR and MDA-MB468/PIGR stable cell lines, overexpressing the PIGR gene, were generated using a lentiviral vector with tetracycline dependent induction of expression. Cell viability, cell proliferation and chemo-sensitivity of PIGR transfected cells were evaluated and compared with un-transfected cells to determine the effect of PIGR overexpression on cell phenotype. The levels of PIGR mRNA and protein expression were significantly higher in MDA-MB468 cells than in MCF7 cells (380-fold, p < 0.0001). However, the differential expression of PIGR in these two cell lines did not lead to significant differences in chemosensitivity. Viral overexpression of PIGR was also not found to change any of the parameters measured in either cell line. PIGR per se did not affect cellular behaviours and chemosensitivity of these breast cancer cell lines.

Polymeric immunoglobulin receptor and galectin-3-binding protein are raised in biliary atresia: Reveals a proteomic-based study

To identify and evaluate differentially expressed plasma proteins in biliary atresia (BA), we performed plasma proteome profiling using liquid chromatography with tandem mass spectrometry (LC-MS/MS) in 20 patients with BA and 10 control children. Serological assays validated the most significant and highly upregulated proteins in a cohort of 45 patients and 15 controls. Bioinformatics tools were used for functional classification and protein-protein interactions of differentially expressed proteins (DEPs). Of 405 proteins detected in patients and 360 in controls, 242 proteins, each with ≥2 unique peptides (total of 3230 peptides), were common in both groups. Compared to controls, 90 proteins in patients were differentially expressed and were dysregulated. Twenty-five were significantly upregulated with polymeric immunoglobulin receptor (PIgR), galectin-3-binding protein (Gal-3BP), complement C2, the most prominent, and 15 had low expression. The bioinformatic analysis revealed functional interaction between DEPs and their role in an inflammatory immune response. Enzyme immunoassay for PIgR and Gal-3BP in patients' plasma showed their levels raised significantly (p = 0.0021 and p = 0.0369, respectively). The PIgR and Gal-3BP are novel proteins upregulated in BA and may be tested further for their utility as potential circulating disease biomarker(s). SIGNIFICANCE: The study shows that plasma PIgR and GAL-3BP levels are significantly raised in infants with BA within the first 3 months of life. If tested in a larger cohort, these proteins may be found to have their diagnostic potential and utility as disease biomarkers. The study also provides valuable information on the involvement of several DEPs in innate immune response, chronic inflammation, and fibrosis. This strengthens the hypothesis that the immune-mediated inflammatory processes are responsible for the progressive nature of BA.

Data-independent acquisition mass spectrometry identification of extracellular vesicle biomarkers for gastric adenocarcinoma

Early diagnosis of gastric adenocarcinoma (GAC) can effectively prevent the progression of the disease and significantly improve patient survival. Currently, protein markers in clinical practice barely meet patient needs; it is therefore imperative to develop new diagnostic biomarkers with high sensitivity and specificity. In this study, we extracted extracellular vesicles (EV) from the sera of 33 patients with GAC and 19 healthy controls, then applied data-independent acquisition (DIA) mass spectrometry to measure protein expression profiles. Differential protein expression analysis identified 23 proteins showing expression patterns across different cancer stages, from which 15 proteins were selected as candidate biomarkers for GAC diagnosis. From this subset of 15 proteins, up to 6 proteins were iteratively selected as features and logistic regression was used to distinguish patients from healthy controls. Furthermore, serum-derived EV from a new cohort of 12 patients with gastric cancer and 18 healthy controls were quantified using the same method. A classification panel consisting of GSN, HP, ORM1, PIGR, and TFRC showed the best performance, with a sensitivity and negative predictive value (NPV) of 0.83 and 0.82. The area under curve (AUC) of the receiver operating characteristic (ROC) is 0.80. Finally, to facilitate the diagnosis of advanced stage GAC, we identified a 3-protein panel consisting of LYZ, SAA1, and F12 that showed reasonably good performance with an AUC of 0.83 in the validation dataset. In conclusion, we identified new protein biomarker panels from serum EVs for early diagnosis of gastric cancer that worth further validation.

Differential plasma proteomes of the patients with Opisthorchiasis viverrini and cholangiocarcinoma identify a polymeric immunoglobulin receptor as a potential biomarker

In Southeast Asian countries, nitrosamine compounds and the liver fluke Opisthorchis viverrini have long been identified as carcinogens for cholangiocarcinoma (CHCA). In order to effectively treat O. viverrini infections and prevent the development of CHCA, methods for disease detection are needed. This study aims to identify biomarkers for O. viverrini infection and CHCA. In the discovery phase, technical triplicates of five pooled plasma pools (10 plasma each) of healthy control subjects (noOVCCA), O. viverrini subjects (OV), and cholangiocarcinoma subjects (CCA), underwent solution-based digestion, with the label-free method, using a Thermo Scientific™ Q Exactive™ HF hybrid quadrupole-Orbitrap mass spectrometer and UltiMate 300 LC systems. The noOVCCA, OV, and CCA groups demonstrated different profiles and were clustered, as illustrated by PCA and heat map analysis. The STRING and reactome analysis showed that both OV and CCA groups up-regulated proteins targeting immune system-related proteins. Differential proteomic profiles, S100A9, and polymeric immunoglobulin receptor (PIGR) were specifically expressed in the CCA group. During the validation phase, another 50 plasma samples were validated via the PIGR sandwich ELISA. Using PIGR >1.559 ng/ml as a cut-off point, 78.00% sensitivity, 71.00% specificity, and AUC = 0.8216, were obtained. It is sufficient to differentially diagnose cholangiocarcinoma patients from healthy patients and those with Opisthorchiasis viverrini. Hence, in this study, PIGR was identified and validated as a potential biomarker for CHCA. Plasma PIGR is suggested for screening CHCA, especially in an endemic region of O. viverrini infection.

M1 macrophages evoke an increase in polymeric immunoglobulin receptor (PIGR) expression in MDA-MB468 breast cancer cells through secretion of interleukin-1β

High expression of polymeric immunoglobulin receptor (PIGR) in breast cancer is associated with increased 5-year survival rate. However, the factors influencing PIGR expression in breast cancer have not been elucidated. The aim of this study was to determine the role of macrophages and cytokines affecting expression of PIGR in two breast cancer cell lines. M1, M2 macrophage conditioned media (CM) and recombinant human cytokines were used to determine factors which increased PIGR expression in MCF7 (HTB-22) and MDA-MB468 (HTB-132) breast cancer cell lines. The level of PIGR expression in the cells and PIGR secretory component were evaluated by real-time quantitative polymerase chain reaction and Western blotting. M1 macrophage CM induced a dose-dependent increase in PIGR mRNA expression in MDA-MB468 cells, up to 20-fold. The level of PIGR expression in MCF7 cells was very low and not affected by M1 and M2 CM. Interferon gamma (IFN-γ) and interleukin (IL)-1β also increased PIGR expression in MDA-MB468 and MCF7 cells. However, IL-1β was demonstrated to increase in M1 macrophages, while IFN-γ was not. The role of IL-1β secreted from M1 macrophages in increasing expression of PIGR was confirmed by IL-1 receptor blockade, indicating that IL-1β was the major M1 macrophage-derived cytokine that enhanced PIGR expression. Elevated PIGR expression in breast cancer in vivo may reflect the polarization state of tumor-associated immune cells.

Polymeric immunoglobulin receptor suppresses colorectal cancer through the AKT-FOXO3/4 axis by downregulating LAMB3 expression

Colorectal cancer (CRC) remains one of the most common malignancies worldwide and its mechanism is unclear. Polymeric immunoglobulin receptor (PIGR) which plays an important role in mucosal immunity is widely expressed in the mucosal epithelium and is dysregulated in different tumors. However, the role and underlying mechanisms of PIGR in CRC remain unclear. Here, we demonstrated that PIGR was hypermethylated and downregulated in our cohort (N = 272), and these features were associated with reduced overall survival in patients (HRmethylation 1.61, 95% CI [1.11-2.33]). These findings were validated by external TCGA and GEO data. Moreover, PIGR overexpression inhibits CRC cell malignant phenotypes in vitro and impedes CRC cells growth in male BALB/c nude mice. Mechanistically, PIGR physically associates with RE1 silencing transcription factor (REST) and blocks the transcription of laminin subunit beta 3 (LAMB3). Subsequently, the AKT-FOXO3/4 axis was suppressed by downregulated LAMB3. In the drug sensitive assay, PIGR-overexpressing cells were more sensitive to cisplatin and gemcitabine. Together, PIGR may serve as a powerful prognostic biomarker and putative tumor suppressor by suppressing the AKT-FOXO3/4 axis by downregulating LAMB3 in CRC. Our study may offer a novel therapeutic strategy for treating CRC patients who highly express PIGR with cisplatin and gemcitabine.

Elevated Protein Kinase A Activity in Stomach Mesenchyme Disrupts Mesenchymal-epithelial Crosstalk and Induces Preneoplasia

BACKGROUND & AIMS

Mesenchymal-epithelial crosstalk (MEC) in the stomach is executed by pathways such as bone morphogenetic protein (BMP) and extracellular signal-regulated kinase (ERK). Mis-regulation of MEC disrupts gastric homeostasis and causes tumorigenesis. Protein Kinase A (PKA) crosstalks with BMP and ERK signaling; however, PKA function(s) in stomach development and homeostasis remains undefined.

METHODS

We generated a novel Six2-Cre^+/-PKAcαR^fl/wt (CA-PKA) mouse in which expression of constitutive-active PKAcαR was induced in gastric mesenchyme progenitors. Lineage tracing determined spatiotemporal activity of Six2-Cre in the stomach. For phenotyping CA-PKA mice histological, co-immunofluorescence, immunoblotting, mRNA sequencing, and bioinformatics analyses were performed.

RESULTS

Lineage tracing showed that Six2-Cre activity in the stomach is restricted to the mesenchymal compartment. CA-PKA mice showed disruption of gastric homeostasis characterized by aberrant mucosal development and epithelial hyperproliferation; ultimately developing multiple features of gastric corpus preneoplasia including decreased parietal cells, mucous cell hyperplasia, spasmolytic peptide expressing metaplasia with intestinal characteristics, and dysplastic and invasive cystic glands. Furthermore, mutant corpus showed marked chronic inflammation characterized by infiltration of lymphocytes and myeloid-derived suppressor cells along with the upregulation of innate and adaptive immune system components. Striking upregulation of inflammatory mediators and STAT3 activation was observed. Mechanistically, we determined there is an activation of ERK1/2 and downregulation of BMP/SMAD signaling characterized by marked upregulation of BMP inhibitor gremlin 1.

CONCLUSIONS

We report a novel role of PKA signaling in gastric MEC execution and show that PKA activation in the gastric mesenchyme drives preneoplasia by creating a proinflammatory and proproliferative microenvironment associated with the downregulation of BMP/SMAD signaling and activation of ERK1/2.

LAMP2 as a Biomarker Related to Prognosis and Immune Infiltration in Esophageal Cancer and Other Cancers: A Comprehensive Pan-Cancer Analysis

Esophageal cancer (ESCA) is a common malignant tumor with poor prognosis. Accumulating evidence indicates an important role of lysosomal-associated membrane protein 2 (LAMP2) in the progression and development of various cancers. In this study, we obtained RNA-sequencing raw count data and the corresponding clinical information for ESCA samples from The Cancer Genome Atlas and Gene Expression Omnibus databases. We comprehensively investigated the expression and prognostic significance of LAMP2 and relationships between LAMP2 expression and prognosis, different clinicopathological parameters, and immune cell infiltration in ESCA. We also obtained the differentially expressed genes between the high LAMP2 expression and low LAMP2 expression groups in ESCA and performed a functional enrichment analysis of the 250 linked genes most positively related to LAMP2 expression. Moreover, we performed the pan-cancer analysis of LAMP2 to further analyze the role of LAMP2 in 25 commonly occurring types of human cancer. We also verified and compared the expression of LAMP2 in 40 samples of human ESCA tissue and adjacent tissues. The results indicated that LAMP2 expression was significantly upregulated in ESCA and various human cancers. In addition, LAMP2 expression was associated with certain clinicopathological parameters, prognosis, and immune infiltration in ESCA and the other types of cancer. Our study represents a comprehensive pan-cancer analysis of LAMP2 and supports the potential use of the modulation of LAMP2 in the management of ESCA and various cancers.

Patient pIgR-enriched extracellular vesicles drive cancer stemness, tumorigenesis and metastasis in hepatocellular carcinoma

BACKGROUND & AIMS

Extracellular vesicles (EVs) play a pivotal role in connecting tumor cells with their local and distant microenvironments. Herein, we aimed to understand the role (on a molecular basis) patient-derived EVs play in modulating cancer stemness and tumorigenesis in the context of hepatocellular carcinoma (HCC).

METHODS

EVs from patient sera were isolated, quantified and characterized. The EVs were vigorously tested, both in vitro and in vivo, through various functional assays. Proteomic analysis was performed to identify the functional components of EVs. The presence and level of polymeric immunoglobulin receptor (pIgR) in circulating EVs and tumor and non-tumorous tissues of patients with HCC were determined by ELISA, immunoblotting, immunohistochemistry and quantitative PCR. The functional role and underlying mechanism of EVs with enhanced pIgR expression were elucidated. Blockade of EV-pIgR with neutralizing antibody was performed in nude mice implanted with patient-derived tumor xenografts (PDTXs).

RESULTS

Circulating EVs from patients with late-stage HCC (L-HCC) had significantly elevated pIgR expression compared to the EVs released by control individuals. The augmenting effect of L-HCC-EVs on cancer stemness and tumorigenesis was hindered by an anti-pIgR antibody. EVs enriched with pIgR consistently promoted cancer stemness and cancerous phenotypes in recipient cells. Mechanistically, EV-pIgR-induced cancer aggressiveness was abrogated by Akt and β-catenin inhibitors, confirming that the role of EV-pIgR depends on the activation of the PDK1/Akt/GSK3β/β-catenin signaling axis. Furthermore, an anti-pIgR neutralizing antibody attenuated tumor growth in mice implanted with PDTXs.

CONCLUSIONS

This study illustrates a previously unknown role of EV-pIgR in regulating cancer stemness and aggressiveness: EV-pIgR activates PDK1/Akt/GSK3β/β-catenin signaling cascades. The blockade of the intercellular communication mediated by EV-pIgR in the tumor microenvironment may provide a new therapeutic strategy for patients with cancer.

LAY SUMMARY

The World Health Organization estimates that more than 1 million patients will die from liver cancer, mostly hepatocellular carcinoma (HCC), in 2030. Understanding the underlying mechanism by which HCC acquires aggressive attributes is crucial to improving the diagnosis and treatment of patients. Herein, we demonstrated that nanometer-sized extracellular vesicles released by tumors promote cancer stemness and tumorigenesis. Within these oncogenic vesicles, we identified a key component that functions as a potent modulator of cancer aggressiveness. By inhibiting this functional component of EVs using a neutralizing antibody, tumor growth was profoundly attenuated in mice. This hints at a potentially effective therapeutic alternative for patients with cancer.

Association of Inflammation-Related Gene Polymorphisms With Susceptibility and Radiotherapy Sensitivity in Head and Neck Squamous Cell Carcinoma Patients in Northeast China

Background

Inflammation-related gene polymorphisms are some of the most important determinants for cancer susceptibility, clinical phenotype diversity, and the response to radiotherapy and chemotherapy. However, the relationship between these polymorphisms and head and neck squamous cell carcinoma (HNSCC) remains unclear. The aim of this study was to investigate the role of inflammation-related gene polymorphisms in the developmental risk and radiotherapy sensitivity of HNSCC.

Methods

The Matrix-Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) genotyping system was used to genotype 612 individuals from a Chinese population for 28 inflammation-related gene polymorphisms.

Results

The protein kinase B (AKT1) rs1130233 TT, dominance model (CT+TT vs. CC), recessive model (TT vs. CT+CC), and rs2494732 CC genotypes were associated with reduced risk of HNSCC (P=0.014; P=0.041; P=0.043). The polymeric immunoglobulin receptor (PIGR) rs291097 GA, dominance model (GA+AA vs. GG), and rs291102 dominance model (GA+AA vs. GG) were associated with increased risk of HNSCC (P=0.025; P=0.025; P=0.040). The interleukin-4 receptor-α (IL-4RA) rs1801275 AA genotype was significantly correlated with increased radiotherapy sensitivity of HNSCC patients (P=0.030). In addition, age ≤ 60 years, non-smoker status, and normal levels of squamous cell carcinoma antigen (SCC) were found to be associated with increased radiotherapy sensitivity of HNSCC patients (P=0.033; P=0.033; P=0.030).

Conclusion

The AKT1 rs1130233, AKT1 rs2494732, PIGR rs291097, and PIGR rs291102 polymorphisms were significantly related to the risk of HNSCC. The IL-4RA rs1801275 polymorphism, age ≤ 60 years, non-smoker status, and normal levels of SCC were significantly associated with increased radiotherapy sensitivity of HNSCC.

Development and validation of 3-CpG methylation prognostic signature based on different survival indicators for colorectal cancer

Abnormal DNA methylation is considered a vital hallmark to regulate gene expression and influence the development and progression of colorectal cancer (CRC). Although CRC-related methylation prognostic models have been developed, their clinical application is limited due to the lack of external validation and extension to other survival evaluation indicators. Therefore, this study aimed to develop and validate novel methylation prognostic models correlated with different survival indicators for individualized prognosis prediction for CRC patients. The prognostic-related CpG sites of methylation-driven genes screened by the MethylMix algorithm were identified and validated in The Cancer Genome Atlas (TCGA) CRC methylation data and our methylation data. The prognostic models correlated with different survival evaluation indicators (overall survival [OS] and disease-free survival [DFS]) were developed and validated in the TCGA CRC dataset (N = 376) and our independent CRC dataset (N = 227). We utilized the combination of selected 3-CpG methylation sites in three genes (DAPP1, FAM3D, and PIGR) to construct a prognostic risk-score model. In the training dataset, Kaplan-Meier survival analysis demonstrated that high-risk patients had significantly poorer survival than low-risk patients (p_OS  = .0014; p_DFS  < .001). Then, the 3-CpG methylation signature was successfully validated as an independent predictor in the testing data set (p_OS  = .016; p_DFS  = .016). A prognostic nomogram was constructed and validated. Additionally, mediation analysis revealed the direct effect of the methylation signature on CRC prognosis (p_OS  = 9.149e-06; p_DFS  = .001). In summary, our study revealed that the 3-CpG methylation signature might be a potential prognostic indicator to facilitate individualized survival prediction for CRC patients.

Proteomics Analysis of Gastric Cancer Patients with Diabetes Mellitus

Proteomics is a powerful approach to study the molecular mechanisms of cancer. In this study, we aim to characterize the proteomic profile of gastric cancer (GC) in patients with diabetes mellitus (DM) type 2. Forty GC tissue samples including 19 cases from diabetic patients and 21 cases from individuals without diabetes (control group) were selected for the proteomics analysis. Gastric tissues were processed following the single-pot, solid-phase-enhanced sample preparation approach-SP3 and enzymatic digestion with trypsin. The resulting peptides were analyzed by LC-MS Liquid Chromatography-Mass Spectrometry (LC-MS). The comparison of protein expression levels between GC samples from diabetic and non-diabetic patients was performed by label-free quantification (LFQ). A total of 6599 protein groups were identified in the 40 samples. Thirty-seven proteins were differentially expressed among the two groups, with 16 upregulated and 21 downregulated in the diabetic cohort. Statistical overrepresentation tests were considered for different annotation sets including the Gene Ontology(GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Reactome, and Disease functional databases. Upregulated proteins in the GC samples from diabetic patients were particularly enriched in respiratory electron transport and alcohol metabolic biological processes, while downregulated proteins were associated with epithelial cancers, intestinal diseases, and cell-cell junction cellular components. Taken together, these results support the data already obtained by previous studies that associate diabetes with metabolic disorders and diabetes-associated diseases, such as Alzheimer's and Parkinson's, and also provide valuable insights into seven GC-associated protein targets, claudin-3, polymeric immunoglobulin receptor protein, cadherin-17, villin-1, transglutaminase-2, desmoglein-2, and mucin-13, which warrant further investigation.

High expression levels of polymeric immunoglobulin receptor are correlated with chemoresistance and poor prognosis in pancreatic cancer

Pancreatic cancer has extremely poor prognosis, warranting the discovery of novel therapeutic and prognostic markers. The expression of polymeric immunoglobulin receptor (pIgR), a key component of the mucosal immune system, is increased in several cancers. However, its clinical relevance in pancreatic cancer remains unclear. In the present study, the prognostic value of pIgR in pancreatic cancer patients after surgical resection was assessed and it was determined that the expression of pIgR was correlated with poor prognosis. Ten pancreatic cancer patient‑derived xenograft (PDX) lines were established, followed by next‑generation sequencing of tumor tissues from these lines after standard chemotherapy. Immunohistochemical analysis of chemoresistance‑related molecules using 77 pancreatic cancer tissues was also performed. The expression of pIgR mRNA in the PDX group treated with anticancer drugs was higher than in the untreated group. High pIgR expression in tissue specimens from 77 pancreatic cancer patients was significantly associated with poor prognosis and was revealed to be an independent prognostic factor, predicting poor outcomes. High pIgR mRNA and protein levels were independent prognostic factors, indicating that pIgR could be a novel predictor for poor prognosis of pancreatic cancer patients.

Label-free peptide quantification coupled with in silico mapping of proteases for identification of potential serum biomarkers in gastric adenocarcinoma patients

OBJECTIVES

We aimed to identify serum level variations in protein-derived peptides between patients diagnosed with gastric adenocarcinoma (GAC) and non-cancer persons (control) to detect the activity changes of proteases and explore the auxiliary diagnostic value in the context of GAC physiopathology.

METHODS

The label-free quantitative peptidome approach was applied to identify variants in serum levels of peptides that can differentiate GAC patients from the control group. Peptide sequences were submitted against Proteasix tool predicting proteases potentially involved in their generation. The activity change of proteases was subsequently estimated based on the peptides with significantly altered relative abundance. In turn, activity change prediction of proteases was correlated with relevant protease expression data from the literature.

RESULTS

A total of 191 peptide sequences generated by the cleavage of 36 precursor proteins were identified. Using the label-free quantification approach, 33 peptides were differentially quantified (adjusted fold change ≥ 1.5 and p-value < 0.05) in which 19 were up-regulated and 14 were down-regulated in GAC samples. Of these peptides, fibrinopeptide A was significantly decreased and its phosphorylated form ADpSGEGDFLAEGGGVR was upregulated in GAC samples. Activity change prediction yielded 10 proteases including 6 Matrix Metalloproteinases (MMPs), Thrombin, Plasmin, and kallikreins 4 and 14. Among predicted proteases in our analysis, MMP-7 was presented as a more promising biomarker associated with useful assays of clinical practice for GAC diagnosis.

CONCLUSION

Our experimental results demonstrate that the serum levels of peptides were significantly differentiated in GAC physiopathology. The hypotheses built on protease regulation could be used for further investigations to measure proteases and their activity levels that have been poorly studied for GAC diagnosis.

The expressions and prognostic implications of Twist and E-cadherin in adenocarcinomas of the gastroesophageal junction and proximal gastric carcinoma

Twist and E-cadherin are crucial for the development of different types of cancer; however, their clinical significance in adenocarcinoma of the gastroesophageal junction (AGE) remains unknown. Here, we investigated the correlation between the expression of Twist and E-cadherin and their impact on the clinical outcomes and prognosis of patients with AGE and proximal gastric carcinoma (PGC).Using immunohistochemistry, we determined the expression of Twist and E-cadherin in the tissue samples of patients with AGE and PGC. The correlation of the expression of Twist and E-cadherin with the clinicopathological factors was assessed by using the chi-square test, Fisher exact test, and non-parametric Mann-Whitney U test. The Kaplan-Meier method along with the log-rank test and Cox proportional-hazards model were used to evaluate the correlation of Twist and E-cadherin expression with the overall survival (OS) of patients.Overall, 94 patients with AGE (n = 45, 47.87%) or PGC (n = 49, 52.13%) who underwent primary tumor resection were included in this study. The median follow-up period was 40.5 months. We observed a significant difference in the smoking status (P < .001) and differentiation grade (P = .004) between patients with AGE and PGC. There was a significant association of a high Twist expression with T stage (only in PGC, P = .008), lymph node metastasis (AGE, P = .075; PGC, P = .051), and advanced pathological stages (AGE, P = .019; PGC, P = .006). A low E-cadherin expression showed similar results; however, it was not significantly associated with the advanced pathological stages of AGE (P = .372). A low E-cadherin expression was significantly associated with a low differentiation grade of AGE (P = .002). In addition, a significant inverse relationship was observed between Twist and E-cadherin expression. The Kaplan-Meier survival analysis and Cox regression analysis revealed that a high Twist expression and low E-cadherin expression were independent prognostic factors for short OS of patients with AGE or PGC.A high Twist expression or low E-cadherin expression was associated with unfavorable clinicopathological factors and independently predicted short OS of patients with AGE or PGC.

Expression of PD-L1 and PD-1 in Chemoradiotherapy-Naïve Esophageal and Gastric Adenocarcinoma: Relationship With Mismatch Repair Status and Survival

Background: The outlook for patients with esophageal and gastric (EG) cancer remains poor. Hence, there is a compelling need to identify novel treatment strategies and complementary biomarkers. Programmed death ligand 1 (PD-L1) and mismatch repair deficiency (dMMR) are putative biomarkers of response to immune-checkpoint blockade, but their prognostic value and interrelationship in EG cancer have been sparsely investigated.

Methods: Immunohistochemical expression of PD-L1 on tumour cells (TC) and tumour-infiltrating immune cells (TIC), and of PD-1 (programmed death receptor 1) on TIC was assessed using tissue microarrays with primary tumours and a subset of paired lymph node metastases from a consecutive, retrospective cohort of 174 patients with chemoradiotherapy-naïve EG adenocarcinoma. MMR proteins MLH1, PMS2, MSH2, and MSH6 were assessed by immunohistochemistry. The total number (intratumoural, tumour-adjacent, and stromal) of CD8⁺ T cells in each core was calculated by automated analysis.

Results: High PD-L1 expression on both TC and TIC, but not PD-1 expression, was significantly associated with dMMR. PD-L1 expression on TIC was significantly higher in lymph node metastases than in primary tumours. High expression of PD-L1 or PD-1 on TIC was significantly associated with a prolonged survival, the former independently of established prognostic factors. A significant stepwise positive association was found between CD8⁺ T cells and categories of PD-L1 expression on TIC.

Conclusion: PD-L1 expression on TIC is higher in lymph node metastases compared to primary tumours, correlates with dMMR, and is an independent factor of prolonged survival in patients with chemoradiotherapy-naïve EG adenocarcinoma. These findings suggest that PD-L1 expression on TIC may be a useful biomarker for identifying patients who may not need additional chemo- or chemoradiotherapy, and who may benefit from PD-1/PD-L1 immune-checkpoint blockade.

CMTCN: a web tool for investigating cancer-specific microRNA and transcription factor co-regulatory networks

Transcription factors (TFs) and microRNAs (miRNAs) are well-characterized trans-acting essential players in gene expression regulation. Growing evidence indicates that TFs and miRNAs can work cooperatively, and their dysregulation has been associated with many diseases including cancer. A unified picture of regulatory interactions of these regulators and their joint target genes would shed light on cancer studies. Although online resources developed to support probing of TF-gene and miRNA-gene interactions are available, online applications for miRNA-TF co-regulatory analysis, especially with a focus on cancers, are lacking. In light of this, we developed a web tool, namely CMTCN (freely available at http://www.cbportal.org/CMTCN), which constructs miRNA-TF co-regulatory networks and conducts comprehensive analyses within the context of particular cancer types. With its user-friendly provision of topological and functional analyses, CMTCN promises to be a reliable and indispensable web tool for biomedical studies.

Podocalyxin-like protein as a predictive biomarker for benefit of neoadjuvant chemotherapy in resectable gastric and esophageal adenocarcinoma

BACKGROUND

We have previously shown that podocalyxin-like protein (PODXL) is a prognostic biomarker for poor survival in gastric and esophageal adenocarcinoma treated with surgery up-front. The aim of the present study was to assess PODXL expression in tumors from patients treated with neoadjuvant ± adjuvant (i.e. preoperative with or without postoperative) chemotherapy, with regard to histopathologic response, time to recurrence (TTR) and overall survival (OS).

METHODS

The neoadjuvant cohort encompasses 148 consecutive patients who received neoadjuvant ± adjuvant chemotherapy for resectable gastric or esophageal adenocarcinoma between 2008 and 2014. Immunohistochemical expression of PODXL was assessed in pre-neoadjuvant biopsies, resected primary tumors and lymph node metastases. Histopathologic response was evaluated using the Chirieac grading. TTR and OS were estimated using Kaplan-Meier and Cox regression analyses. To investigate a potential predictive role for PODXL, the neoadjuvant cohort was pooled with the previously reported surgery up-front cohort.

RESULTS

The majority (> 95%) of the patients were treated with fluoropyrimidine- and oxaliplatin-based chemotherapy. Patients with high PODXL expression in their pre-neoadjuvant biopsies had a superior histopathologic response (notably 36% with no residual cancer cells) compared to those with negative or low PODXL expression, and were all recurrence-free at last follow-up. In the pooled cohort, no benefit of chemotherapy could be shown for PODXL negative cases, whereas PODXL positive (low or high) cases had a prolonged TTR and OS when treated with neoadjuvant ± adjuvant chemotherapy compared to surgery alone. The potential predictive role of PODXL was further strengthened for TTR in Cox regression analyses, especially for patients treated with neoadjuvant fluoropyrimidine and oxaliplatin for a minimum of 8 weeks, with a significant interaction term in both unadjusted (p = 0.006) and adjusted (p = 0.024) analyses. The interaction term was not statistically significant for overall survival.

CONCLUSIONS

Patients with resectable gastric or esophageal adenocarcinoma with high PODXL expression in their diagnostic biopsies have an excellent prognosis when treated with neoadjuvant ± adjuvant fluoropyrimidine- and oxaliplatin-based chemotherapy. If the suggested predictive role of PODXL for benefit of chemotherapy can be confirmed, patients with PODXL negative tumors could be spared chemotherapy and treated with surgery alone.

The integrative clinical impact of tumor-infiltrating T lymphocytes and NK cells in relation to B lymphocyte and plasma cell density in esophageal and gastric adenocarcinoma

Background

Several studies have demonstrated a prognostic impact of tumor-infiltrating T lymphocytes and natural killer (NK) cells in esophageal and gastric adenocarcinoma, but whether these associations differ by the density of tumor-infiltrating immune cells of the B cell lineage remains largely unknown.

Results

High infiltration of any T and NK lymphocytes investigated was in general associated with a favorable prognosis, but the strongest beneficial prognostic impact was seen in combination with high B lymphocyte infiltration. These findings were most evident in gastric cancer, where significant interactions in relation to OS were observed for CD3⁺, CD8⁺ and FoxP3⁺ with CD20⁺ cells (p_interaction =0.012, 0.009 and 0.007, respectively) and for FoxP3⁺ with IGKC⁺ cells (p_interaction =0.034). In esophageal tumors, there was only a significant interaction for CD3⁺ and CD20 ⁺ cells (p_interaction =0.028).

Methods

Immunohistochemistry and automated image analysis was applied to assess the density of T lymphocytes (CD3⁺, CD8⁺, FoxP3⁺) and NK cells (NKp46⁺) in chemoradiotherapy-naïve tumors from a consecutive cohort of 174 patients with resected esophageal or gastric adenocarcinoma. The density of B lymphocytes (CD20⁺) and plasma cells (IGKC⁺) had been assessed previously. Kaplan-Meier analysis and Cox proportional hazard's modelling was applied to examine the impact of the investigated markers on time to recurrence (TTR) and overall survival (OS).

Conclusions

These data support that the antitumoral effects of tumor-infiltrating T lymphocytes in esophageal and gastric adenocarcinoma may be largely dependent on a functional interplay between T and B lymphocytes or plasma cells.

Prognostic impact of tumour-associated B cells and plasma cells in oesophageal and gastric adenocarcinoma

BACKGROUND

While it is well established that the cell-mediated immune response plays an important role in cancer progression and spread, the role of the humoral immune response in this regard has been less studied. According to the existing literature, dense infiltration of B cells or plasma cells appears to correlate mainly with an improved prognosis in several types of cancer, but their prognostic impact in oesophageal and gastric cancer has not yet been described.

METHODS

Immunohistochemistry was applied on tissue microarrays (TMA) to assess the stromal density of B cells (CD20+) and plasma cells [CD138+ or immunoglobulin kappa C (IGKC+)] in chemo-/radiotherapy-naive tumours from a consecutive cohort of 174 patients with resected oesophageal or gastric adenocarcinoma. Cox proportional hazard's modelling was applied to examine the impact of the investigated markers on overall survival (OS) and time to recurrence (TTR).

RESULTS

In curatively treated patients with oesophageal adenocarcinoma, high expression of IGKC was an independent predictor of a prolonged OS [hazard ratio (HR) 0.10; 95% confidence interval (CI), 0.02-0.57], and TTR (HR 0.15; 95% CI, 0.03-0.71). In curatively treated patients with gastric adenocarcinoma, high expression of IGKC independently predicted a prolonged OS (HR 0.46; 95% CI, 0.24-0.87) and TTR (HR 0.46; 95% CI, 0.21-0.98). Expression of CD20 was not prognostic, and CD138 expression was only prognostic in unadjusted analysis of TTR in gastric cancer.

CONCLUSIONS

These results demonstrate, for the first time, that abundant infiltration of IGKC+ plasma cells independently predicts a prolonged survival in both oesophageal and gastric cancer.

Expression of podocalyxin-like protein is an independent prognostic biomarker in resected esophageal and gastric adenocarcinoma

BACKGROUND

Podocalyxin-like protein (PODXL) is a cell surface transmembrane glycoprotein, the expression of which has been associated with poor prognosis in a range of malignancies. The aim of this study was to investigate the impact of PODXL expression on survival in esophageal and gastric adenocarcinoma.

METHODS

The study cohort consists of a consecutive series of 174 patients with esophageal (including the gastroesophageal junction) or gastric adenocarcinoma, surgically treated between 2006 and 2010 and not subjected to neoadjuvant treatment. Immunohistochemical expression of PODXL was assessed in tissue microarrays with cores from primary tumors, lymph node metastases, intestinal metaplasia and adjacent normal epithelium. Survival analyses were performed on patients with no distant metastases and no macroscopic residual tumor.

RESULTS

In the majority of cases, expression of PODXL was significantly higher in cancer cells compared to normal epithelial cells and was significantly associated with lymph node metastases and high grade tumors. In esophageal adenocarcinoma, Kaplan-Meier analyses revealed that patients with PODXL negative tumors had a superior time to recurrence (TTR) and overall survival (OS) compared to patients with PODXL positive tumors. In gastric adenocarcinoma, patients with PODXL negative tumors had a superior TTR and a trend towards an improved OS. In esophageal and gastric adenocarcinoma combined, the prognostic significance of PODXL expression on TTR was confirmed in unadjusted Cox regression analysis (HR = 5.36, 95 % CI 1.68-17.06, p = 0.005) and remained significant in the adjusted model (HR = 3.39, 95 % CI 1.01-11.35, p = 0.048). Moreover, the impact of PODXL expression on OS was also confirmed in unadjusted analysis (HR = 2.52, 95 % CI 1.31-4.85, p = 0.006) and remained significant in the adjusted model (HR = 2.03, 95 % CI 1.04-3.98, p = 0.039).

CONCLUSIONS

In esophageal and gastric adenocarcinoma, PODXL expression is an independent prognostic biomarker for reduced time to recurrence and poor overall survival. This is the first report on the prognostic role of PODXL in esophageal adenocarcinoma and validates recent findings in gastric cancer.

Expression of IFITM1 as a prognostic biomarker in resected gastric and esophageal adenocarcinoma

BACKGROUND

There is an increasing amount of reports on IFITM1 (interferon-inducible transmembrane protein 1) in various malignancies. The aim of this study was to examine the expression of IFITM1 and its prognostic significance in gastroesophageal adenocarcinoma.

METHODS

Tissue samples were obtained from a consecutive cohort of 174 patients surgically treated between 2006 and 2010 for gastroesophageal (gastric, gastroesophageal junction and esophageal) adenocarcinoma, not subjected to neoadjuvant therapy. Expression of IFITM1 was examined using immunohistochemistry on tissue microarrays of primary tumors and paired samples of adjacent normal epithelium, intestinal metaplasia and lymph node metastases.

RESULTS

Expression of IFITM1 was significantly elevated in primary tumors and lymph node metastases compared to adjacent normal epithelium and intestinal metaplasia, regardless of tumor location. Overexpression of IFITM1 was associated with M0-disease (no distant metastases). In gastric cancer IFITM1 expression was significantly associated with improved TTR (time to recurrence) in Kaplan-Meier analysis and Cox regression, both in the unadjusted analysis (HR 0.33, 95 % CI 0.12-0.88) and in the adjusted analysis (HR 0.32, 95 % CI 0.12-0.87) but there was no significant impact on OS (overall survival). In esophageal adenocarcinoma expression of IFITM1 had no impact on TTR or OS in Kaplan-Meier-analyses, but in the adjusted Cox regression IFITM1 expression had a negative impact on both TTR (HR 3.05, 95 % CI 1.09-8.53) and OS (HR 2.71, 95 % CI 1.11-6.67).

CONCLUSIONS

IFITM1 was overexpressed in gastroesophageal adenocarcinoma and associated with M0-disease. In gastric cancer IFITM1 expression had a positive impact on TTR but in esophageal cancer it seemed to have an adverse impact on survival. The reason for the diverging prognostic impact of IFITM1 in esophageal and gastric cancer is unclear and warrants further studies.

Prognostic impact of tumour-associated B cells and plasma cells in epithelial ovarian cancer

BACKGROUND

The critical role of the immune system in controlling cancer progression has become evident and immune modulatory therapy is now approved for clinical use. However, while the majority of studies on the inflammatory tumour microenvironment have focused on the cellular immune response, in particular the prognostic and predictive role of various T cell infiltrates, the role of the humoral immune response in this context has long been overlooked. This study aimed to investigate the clinicopathological correlates and prognostic impact of B cell and plasma cell infiltration in epithelial ovarian cancer (EOC).

METHODS

Immunohistochemical expression of immunoglobulin kappa C (IGKC), CD20 and CD138 was analysed in tissue microarrays with tumours from 154 incident cases of EOC from two pooled prospective population-based cohorts. Subsets of corresponding benign-appearing fallopian tubes (n = 38) and omental metastases (n = 33) were also analysed. Kaplan-Meier analysis and Cox regression analysis were used to determine the impact of immune-cell specific IGKC, CD20 and CD138 expression on overall survival and ovarian cancer-specific survival.

RESULTS

High IGKC expression correlated significantly with expression of CD20 (p = 0.001) and CD138 (p = 0.035). Expression of IGKC as well as CD138 was significantly higher in primary tumours than in fallopian tubes (p = 0.004 and p = 0.001, respectively). High CD20 and CD138 expression correlated significantly with high tumour grade (p = 0.032 and p = 0.030, respectively). CD20 and IGKC expression was not prognostic but univariable Cox regression analysis revealed high CD138 expression to correlate with a significantly reduced overall survival (HR = 2.20; 95 % CI 1.34-3.55; p-0.001) as well as ovarian cancer-specific survival (HR = 1.95; 95 % CI 1.28-2.98; p = 0.002). The prognostic impact was independent of established clinical parameters (age, grade, clinical stage) as shown in multivariable analysis (HR = 2.28; 95 % CI 1.39-3.75; p = 0.001).

CONCLUSIONS

In conclusion, our results demonstrate that plasma cell infiltration in epithelial ovarian cancer has a significant impact on tumour progression and prognosis. The important role of the humoral immune system merits further study and may be harnessed as immune modulatory strategies in cancer therapy.

Reduced expression of polymeric immunoglobulin receptor (pIgR) in nasopharyngeal carcinoma and its correlation with prognosis

Polymeric immunoglobulin receptor (pIgR) is a key component of the mucosal immune system that mediates epithelial transcytosis of immunoglobulins. The expression of pIgR was reported to be up-regulated and related to the prognosis of several human cancers. However, the clinical significance of pIgR in nasopharyngeal carcinoma (NPC) remains unclear. The purpose of this study was to detect the pIgR expression and its prognostic value in NPC. The expression of serum pIgR was measured in NPC patients and healthy controls by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and western blotting analyses. The relationship between its expression and clinical factors was analyzed by chi-square test. Then, the overall survival of patients was assessed by Kaplan-Meier analysis while the prognostic value of serum pIgR was estimated using univariate and multivariate analyses with cox regression analysis. Serum pIgR was down-regulated in NPC patients compared to that in healthy controls both at messenger RNA (mRNA) and protein levels. Especially, its expression was also significantly lower in patients at advantage stages (III-IV) than those at early stages (I-II). And, the low pIgR expression was strongly associated with advanced clinical stages, T stage, N stage, and distant metastasis. Kaplan-Meier analysis demonstrated that patients with low pIgR expression had a significantly shorter overall survival than those with high expression at any stages. Cox regression analysis suggested that pIgR was closely related to the prognosis of NPC. Serum pIgR expression was reduced in NPC, and it could be an independent prognostic predictor for patients with this cancer.

Expression and Prognostic Significance of Human Epidermal Growth Factor Receptors 1 and 3 in Gastric and Esophageal Adenocarcinoma

Background

Gastric and esophageal adenocarcinomas are major global cancer burdens. These cancer forms are characterized by a poor prognosis and a modest response to chemo- radio- and targeted treatment. Hence there is an obvious need for further enhanced diagnostic and treatment strategies. The aim of this study was to examine the expression and prognostic impact of human epidermal growth factor receptor 1 (HER1/EGFR) and 3 (HER3), as well as the occurrence of EGFR and KRAS mutations in gastric and esophageal adenocarcinoma.

Methods

Immunohistochemical expression of EGFR and HER3 was analysed in all primary tumours and a subset of lymph node metastases in a consecutive cohort of 174 patients with adenocarcinoma of the stomach, cardia and esophagus. The anti-HER3 antibody used was validated by siRNA-mediated knockdown, immunohistochemistry and quantitative real-time PCR. EGFR and KRAS mutation status was analysed by pyrosequencing tecchnology.

Results and Discussion

High EGFR expression was an independent risk factor for shorter overall survival (OS), whereas high HER3 expression was associated with a borderline significant trend towards a longer OS. KRAS mutations were present in only 4% of the tumours and had no prognostic impact. All tumours were EGFR wild-type. These findings contribute to the ongoing efforts to decide on the potential clinical value of different HERs and druggable mutations in gastric and esophageal adenocarcinomas, and attention is drawn to the need for more standardised investigational methods.

Reduced expression of the polymeric immunoglobulin receptor in pancreatic and periampullary adenocarcinoma signifies tumour progression and poor prognosis

The polymeric immunoglobulin receptor (pIgR) is a key component of the mucosal immune system that mediates epithelial transcytosis of immunoglobulins. High pIgR expression has been reported to correlate with a less aggressive tumour phenotype and an improved prognosis in several human cancer types. Here, we examined the expression and prognostic significance of pIgR in pancreatic and periampullary adenocarcinoma. The study cohort encompasses a consecutive series of 175 patients surgically treated with pancreaticoduodenectomy for pancreatic and periampullary adenocarcinoma in Malmö and Lund University Hospitals, Sweden, between 2001–2011. Tissue microarrays were constructed from primary tumours (n = 175) and paired lymph node metastases (n = 105). A multiplied score was calculated from the fraction and intensity of pIgR staining. Classification and regression tree analysis was used to select the prognostic cut-off. Unadjusted and adjusted hazard ratios (HR) for death and recurrence within 5 years were calculated. pIgR expression could be evaluated in 172/175 (98.3%) primary tumours and in 96/105 (91.4%) lymph node metastases. pIgR expression was significantly down-regulated in lymph node metastases as compared with primary tumours (p = 0.018). Low pIgR expression was significantly associated with poor differentiation grade (p<0.001), perineural growth (p = 0.027), lymphatic invasion (p = 0.016), vascular invasion (p = 0.033) and infiltration of the peripancreatic fat (p = 0.039). In the entire cohort, low pIgR expression was significantly associated with an impaired 5-year survival (HR = 2.99, 95% confidence interval (CI) 1.71–5.25) and early recurrence (HR = 2.89, 95% CI 1.67–4.98). This association remained significant for survival after adjustment for conventional clinicopathological factors, tumour origin and adjuvant treatment (HR = 1.98, 95% CI 1.10–3.57). These results demonstrate, for the first time, that high tumour-specific pIgR expression signifies a more favourable tumour phenotype and that low expression independently predicts a shorter survival in patients with pancreatic and periampullary cancer. The mechanistic basis for the putative tumour suppressing properties of pIgR in these cancers merits further study.

SATB1 is an independent prognostic factor in radically resected upper gastrointestinal tract adenocarcinoma

Gastric cancer is the second most common cause of cancer-related death worldwide, and the incidence of esophageal adenocarcinoma is rising. While some progress has been made in treatment strategies, overall survival remains very poor for patients with adenocarcinoma in the upper gastrointestinal tract. Special AT-rich sequence binding protein 1 (SATB1) is a global genome organizer that has been demonstrated to promote aggressive tumor behavior in several different types of cancer, including gastric cancer. The prognostic value of SATB1 expression in esophageal cancer has, however, not yet been described. In this study, expression of SATB1 was examined by immunohistochemistry on tissue microarrays prepared from tissue samples from 175 patients with adenocarcinoma of the esophagus, cardia, or stomach and containing normal tissue, intestinal metaplasia, primary tumors, and metastases. A well-validated antibody was used. We found SATB1 to be an independent prognostic factor in patients with a radically resected tumor, correlating with shorter overall survival as well as with shorter recurrence-free survival. SATB1 expression was also found to be significantly lower in primary tumors associated with intestinal metaplasia than those without intestinal metaplasia. This observation is of potential biological interest as it has been proposed that intestinal metaplasia-associated tumors constitute a less aggressive phenotype.

High expression of RNA-binding motif protein 3 in esophageal and gastric adenocarcinoma correlates with intestinal metaplasia-associated tumours and independently predicts a reduced risk of recurrence and death

Background

High nuclear expression of the RNA-binding motif protein 3 (RBM3) has previously been found to correlate with favourable clinicopathological characteristics and a prolonged survival in several cancer forms. Here, we examined the clinicopathological correlates and prognostic significance of RBM3 expression in tumours from a consecutive cohort of upper gastrointestinal adenocarcinoma.

Material and methods

Immunohistochemical RBM3 expression was analysed in tissue microarrays with primary radiotherapy- and chemotherapy-naive adenocarcinoma of the esophagus, gastroesophageal junction and stomach (n = 173). In addition paired samples of normal squamous epithelium (n = 53), gastric mucosa (n = 117), Barrett’s esophagus/gastric intestinal metaplasia (n = 61) and lymph node metastases (n = 71) were analysed. Kaplan-Meier analysis and Cox proportional hazards modelling was applied to assess the impact of RBM3 expression on overall survival (OS) and recurrence-free survival (RFS).

Results

RBM3 expression was similar in primary tumours and lymph node metastases, but significantly higher in primary tumours and metastases arising in a background of intestinal metaplasia compared with cases without intestinal metaplasia (p < 0.001). RBM3 expression was significantly reduced in more advanced tumour stages (p = 0.006). Low RBM3 expression was significantly associated with a shorter OS in cases with radically resected (R0) tumours (HR 2.19, 95% CI 1.33-3.61, p = 0.002) and RFS in curatively treated patients with R0 resection/distant metastasis-free disease (HR = 3.21, 95% CI 1.64-6.30, p = 0.001). These associations remained significant in adjusted analysis (HR = 1.95, 95% CI 1.17-3.25, p = 0.010 for OS and HR = 3.02, 95% CI 1.45-6.29, p = 0.003 for RFS).

Conclusion

High expression of RBM3 may signify a subset of upper gastrointestinal cancers arising in a background of intestinal metaplasia and independently predicts a reduced risk of recurrence and death in patients with these cancer forms. These findings are of potential clinical utility and merit further validation.