Gastrin stimulates receptor-mediated proliferation of human esophageal adenocarcinoma cells

Pharmacoepidemiological Research on N-Nitrosodimethylamine-Contaminated Ranitidine Use and Long-Term Cancer Risk: A Population-Based Longitudinal Cohort Study

N-Nitrosodimethylamine (NDMA), a carcinogenic chemical, has recently been identified in ranitidine. We conducted a population-based study to explore ranitidine use and cancer emergence over time. Using the Taiwan National Health Insurance Research Database, a population-based cohort study was conducted. A total of 55,110 eligible patients who received ranitidine between January 2000 and December 2018 were enrolled in the treated cohort. We conducted a 1:1 propensity-score-matching procedure to match the ranitidine-treated group with the ranitidine-untreated group and famotidine controls for a longitudinal study. The association of ranitidine exposure with cancer outcomes was assessed. A multivariable Cox regression analysis that compared cancer risk with the untreated groups revealed that ranitidine increased the risk of liver (hazard ratio (HR): 1.22, 95% confidence interval (CI): 1.09-1.36, p < 0.001), lung (HR: 1.17, CI: 1.05-1.31, p = 0.005), gastric (HR: 1.26, CI: 1.05-1.52, p = 0.012), and pancreatic cancers (HR 1.35, CI: 1.03-1.77, p = 0.030). Our real-world observational study strongly supports the pathogenic role of NDMA contamination, given that long-term ranitidine use is associated with a higher likelihood of liver cancer development in ranitidine users compared with the control groups of non-ranitidine users treated with famotidine or proton-pump inhibitors.

Association Between Acid-Suppressive Agents’ Use and Risk of Hepatocellular Carcinoma

Background:

Acid-suppressive agents (ASAs), which are mostly used in patients with upper gastrointestinal diseases (UGIDs), may influence the risk of hepatocellular carcinoma (HCC).

Methods:

A population-based retrospective cohort study was conducted. Patients with UGID who used ASAs and those who did not receive ASAs were identified. Patients without UGIDs were randomly selected and matched (comparison group). All groups were followed up for 6 years. A Cox proportional hazard model was used to estimate the risk of HCC among the different groups.

Results:

Patients with UGID who used ASAs had a significantly elevated HCC risk (adjusted hazard ratio [HR] 1.53; 95% confidence interval [CI], 1.32-1.76] compared to those who did not use ASAs. Patients with UGID who used more than 540 defined daily doses of ASAs had a significantly higher risk of HCC (adjusted HR 2.04; 95% CI, 1.62-2.58). Moreover, the dose effect on HCC risk exhibited a significant increasing trend ( P < .01). Furthermore, patients with UGID who did not use ASAs had a significantly elevated HCC risk (adjusted HR 1.94; 95% CI, 1.59-2.36) compared to the comparison group.

Conclusion:

The use of ASAs increased the risk of HCC in patients with UGIDs, and the effect of ASAs was dose dependent. In addition, UGIDs alone increased the risk of HCC.

Exploiting cancer's phenotypic guise against itself: targeting ectopically expressed peptide G-protein coupled receptors for lung cancer therapy

Lung cancer, claiming millions of lives annually, has the highest mortality rate worldwide. This advocates the development of novel cancer therapies that are highly toxic for cancer cells but negligibly toxic for healthy cells. One of the effective treatments is targeting overexpressed surface receptors of cancer cells with receptor-specific drugs. The receptors-in-focus in the current review are the G-protein coupled receptors (GPCRs), which are often overexpressed in various types of tumors. The peptide subfamily of GPCRs is the pivot of the current article owing to the high affinity and specificity to and of their cognate peptide ligands, and the proven efficacy of peptide-based therapeutics. The article summarizes various ectopically expressed peptide GPCRs in lung cancer, namely, Cholecystokinin-B/Gastrin receptor, the Bombesin receptor family, Bradykinin B1 and B2 receptors, Arginine vasopressin receptors 1a, 1b and 2, and the Somatostatin receptor type 2. The autocrine growth and pro-proliferative pathways they mediate, and the distinct tumor-inhibitory effects of somatostatin receptors are then discussed. The next section covers how these pathways may be influenced or 'corrected' through therapeutics (involving agonists and antagonists) targeting the overexpressed peptide GPCRs. The review proceeds on to Nano-scaled delivery platforms, which enclose chemotherapeutic agents and are decorated with peptide ligands on their external surface, as an effective means of targeting cancer cells. We conclude that targeting these overexpressed peptide GPCRs is potentially evolving as a highly promising form of lung cancer therapy.

Hypergastrinemia

Gastrin is an important hormone of the digestive system, which assists gastric acid secretion. It may be pathologically elevated in conditions such as Zollinger-Ellison syndrome, or due to common medications such as proton pump inhibitors. In this review we provide an overview of the pathophysiology and medical causes of hypergastrinemia, diagnostic testing and clinical consequences of chronic hypergastrinemia.

Cholecystokinin and pancreatic cancer: the chicken or the egg?

The gastrointestinal peptide cholecystokinin (CCK) causes the release of pancreatic digestive enzymes and growth of the normal pancreas. Exogenous CCK administration has been used in animal models to study pancreatitis and also as a promoter of carcinogen-induced or Kras-driven pancreatic cancer. Defining CCK receptors in normal human pancreas has been problematic because of its retroperitoneal location, high concentrations of pancreatic proteases, and endogenous RNase. Most studies indicate that the predominant receptor in human pancreas is the CCK-B type, and CCK-A is the predominant form in rodent pancreas. In pancreatic cancer cells and tumors, the role of CCK is better established because receptors are often overexpressed by these cancer cells and stimulation of such receptors promotes growth. Furthermore, in established cancer, endogenous production of CCK and/or gastrin occurs and their actions stimulate the synthesis of more receptors plus growth by an autocrine mechanism. Initially it was thought that the mechanism by which CCK served to potentiate carcinogenesis was by interplay with inflammation in the pancreatic microenvironment. But with the recent findings of CCK receptors on early PanIN (pancreatic intraepithelial neoplasia) lesions and on stellate cells, the question has been raised that perhaps CCK actions are not the result of cancer but an early driving promoter of cancer. This review will summarize what is known regarding CCK, its receptors, and pancreatic cancer, and also what is unknown and requires further investigation to determine which comes first, the chicken or the egg, "CCK or the cancer."

rG17PE38, a novel immunotoxin target to gastric cancer with overexpressed CCK-2R

BACKGROUND

Gastrin/cholecystokinin subtype 2 receptor (CCK2R) is overexpressed in several types of tumors. Gastrin-17 (G17) peptide has a high affinity with CCK2R. These characters suggest that G17 may be useful for target cancer therapy.

PURPOSE

Construct a new immunotoxin (IT) targeting of CCK2R overexpressed gastric cancer.

METHODS

Two ITs were generated using forward and reverse G17 peptides fused with PE38. To get a high yield, codon optimized gene and optimized fermentation parameters were used in large-scale protein expression. An immunoaffinity technique was introduced into pseudomonas exotoxin (PE)-derived IT purification procedure. G17 competition, GST pull-down and indirect immunoflourescence assays were carried out to confirm the interaction between rG17 and CCK2R. Then, several cytotoxic assays were carried out on 18 cell lines, and an in vivo antitumor activity experiment was tested in nude mice.

RESULTS

The rG17PE38 showed specific cytotoxicity on three gastric cancer cells, while G17PE38 did not. After optimization, the expression level reached about 40% in medium deprived of NaCl. Next, 15-27.5 mg of pure rG17PE38 per 1 L of cultures was obtained. Results of G17 competition, GST pull-down and indirect immunoflourescence assays demonstrated that rG17 have a specific interact with CCK2R. Purified rG17PE38 showed high cytotoxicity on gastric cancer cell lines with the IC50 value of 0.6-4 ng·mL(-1). Treatment of nude mice inoculated with BGC-823 tumor xenografts with rG17PE38 efficiently inhibited tumor size.

CONCLUSIONS AND DISCUSSION

The present study demonstrates that reversed G17 could be used as target moiety of PE-derived IT and the rG17PE38 could be developed as a new immunotherapy agent. Codon optimized gene could increase the rG17PE38 expression level in E. coli and furthermore NaCl inhibits the rG17PE38 expression in large scale. Meanwhile, our present study inducts an immunoaffinity method in the IT purification procedure, which could purify the PE-derived ITs in native form.

Role of gastrin-peptides in Barrett's and colorectal carcinogenesis

Gastrin is the main hormone responsible for the stimulation of gastric acid secretion; in addition, gastrin and its derivatives exert proliferative and antiapoptotic effects on several cell types. Gastrin synthesis and secretion are increased in certain situations, for example, when proton pump inhibitors are used. The impact of sustained hypergastrinemia is currently being investigated. In vitro experiments and animal models have shown that prolonged hypergastrinemia may be related with higher cancer rates; although, this relationship is less clear in human beings. Higher gastrin levels have been shown to cause hyperplasia of several cell types; yet, the risk for developing cancer seems to be the same in normo- and hypergastrinemic patients. Some tumors also produce their own gastrin, which can act in an autocrine manner promoting tumor growth. Certain cancers are extremely dependent on gastrin to proliferate. Initial research focused only on the effects of amidated gastrins, but there has been an interest in intermediates of gastrin in the last few decades. These intermediates aren’t biologically inactive; in fact, they may exert greater effects on proliferation and apoptosis than the completely processed forms. In certain gastrin overproduction states, they are the most abundant gastrin peptides secreted. The purpose of this review is to examine the gastrin biosynthesis process and to summarize the results from different studies evaluating the production, levels, and effects of the main forms of gastrin in different overexpression states and their possible relationship with Barrett’s and colorectal carcinogenesis.

Cholecystokinin and gastrin receptors targeting in gastrointestinal cancer

Cholecystokinin and Gastrin are amongst the first gastrointestinal hormone discovered. In addition to classical actions (contraction of gallbladder, growth and secretion in the stomach and pancreas), these also act as growth stimulants for gastrointestinal malignancies and cell lines. Growth of these tumours is inhibited by antagonists of the cholecystokinin and gastrin receptors. These receptors provides most promising approach in clinical oncology and several specific radiolabelled ligands have been synthesized for specific tumour targeting and therapy of tumours overexpressing these receptors. Therefore, definition of the molecular structure of the receptor involved in the autocrine/paracrine loop may contribute to novel therapies for gastrointestinal cancer. Hence, this review tries to focus on the role and distribution of these hormones and their receptors in gastrointestinal cancer with a brief talk about the clinical trial using available agonist and antagonist in gastrointestinal cancers.

Elevated serum gastrin is associated with a history of advanced neoplasia in Barrett's esophagus

OBJECTIVES

Proton pump inhibitors (PPIs) are frequently prescribed to patients with Barrett's esophagus (BE), but in a subset, they can induce significant hypergastrinemia. Elevated levels of gastrin have been associated with tumorigenic effects in a number of gastrointestinal cancers. We decided to investigate the association between serum gastrin levels and dysplasia in BE.

METHODS

We performed a cross-sectional study and enrolled patients with BE without dysplasia, low-grade dysplasia (LGD), high-grade dysplasia (HGD), or adenocarcinoma (AC), as well as gastroesophageal reflux disease controls, all chronically taking PPIs. Fasting serum gastrin was measured, and data were collected on patient characteristics, medication use, and the highest degree of BE neoplasia.

RESULTS

A total of 95 patients were enrolled. The mean age was 64.7 (+/-10.0) years, and 70.5% were male. The median serum gastrin level was 40 pM. There was no significant difference in gastrin levels with increased degrees of BE neoplasia (overall P=0.68). In multivariable analysis, the highest quartile of gastrin was associated with significantly increased odds of advanced neoplasia (HGD or AC) (odds ratio (OR): 5.46, 95% confidence interval (CI): 1.20-24.8).

CONCLUSIONS

In BE patients taking PPIs, an elevated serum gastrin is associated with a history of HGD or AC. Prospective studies are needed to determine whether patients with nondysplastic BE and elevated serum gastrin are at increased risk for neoplastic progression.

High prevalence of colonic polyps in white males with esophageal adenocarcinoma

PURPOSE

There is ongoing discussion regarding Barrett's esophagus and the prevalence of colonic neoplasms. The goal of this investigation was to evaluate colonoscopic findings in patients with esophageal carcinoma.

METHODS

In this case-control study, we used the data of patients with esophagectomy. These patients underwent routine preoperative endoscopy of the entire colon to exclude pathologic findings pending the need for colonic bridging graft reconstruction. A total of 171 patients with esophageal cancer (78 adenocarcinomas, 93 squamous-cell carcinomas, and 168 control subjects) who underwent screening colonoscopy were included. Univariate analysis and multinomial logistic regression were used to calculate odds ratios for colonic polyps.

RESULTS

The age of the three groups of patients was comparable (median age: adenocarcinoma = 62 years, squamous-cell carcinoma = 58 years, control subjects = 59 years). The male to female ratio differed significantly (adenocarcinoma = 71:7, squamous-cell carcinoma = 65:28, control subjects = 86:82; P < 0.001). Patients with adenocarcinoma had more findings on colonoscopy than patients with squamous-cell carcinoma (45 and 25 percent, respectively; P < 0.01) or control subjects (14 percent; P < 0.001). Analyzing the male data only, the difference was more pronounced. The histologic type of the esophageal tumor significantly impacted the presence of colorectal polyps even with age-adjusted and sex-adjusted data (P < 0.001), with an odds ratio of 4.03 for adenocarcinoma.

CONCLUSION

These results demonstrate a significant relationship between the development of Barrett's carcinoma and colonic polyps.

Immunohistochemical examination of gastrin, gastrin precursors, and gastrin/CCK-2 receptor in human esophageal squamous cell carcinomas

A promoting effect of gastrin on stimulating Barrett's oesophagus proliferation has been demonstrated, but whether it plays a regulating role for esophageal squamous cell carcinoma (ESCC) to date has not been fully investigated. The aim of this study is to examine the expressions of gastrin, gastrin precursors and gastrin/CCK-2 receptor in ESCC. Tissue specimen sections from 38 patients with ESSC obtained from a high incidence area of north China were assessed using immunohistochemistry for amidated gastrin, gastrin precursors (progastrin and glycine-extended gastrin) and gastrin/CCK-2 receptors. Their clinical histopathological significance was also analyzed. Of 38 ESCC, the immunoreactivities of gastrin, glycine-extended gastrin and progastrin were observed in 13.2% (5/38), 7.9% (3/38) and 23.68% (9/38) cases. The expression of progastrin was obviously higher than other gastrins, though not significantly (P > 0.05). In positive cases for gastrin or glycine-extended gastrin, the scores of positive tumor cell numbers were at a lower density (<10/abundant-distributed field). However, the scores of progastrin positive tumor cell density in five of nine positive cases were over 10/abundant-distributed field. The immunoreactivity of gastrin/CCK-2 receptor was also observed in 15.8% (6/38) ESCC cases. There was not significant correlation regarding immunohistochemical results with known histomorphological parameters i.e. gender, tumor location and TNM stages. Based on our current results, ESCC tumor cells could be a possible cellular source of gastrin precursors, which has been postulated to play a role in regulating the growth in some human tumor cells.

Pre-clinical evaluation of a new orally-active CCK-2R antagonist, Z-360, in gastrointestinal cancer models

BACKGROUND

Gastrin has a role in gastrointestinal (GI) malignancy. This study provides pre-clinical evaluation of a novel, orally-active gastrin/cholecystokinin-2 receptor (CCK-2R) antagonist, Z-360.

METHODS

(125)I gastrin-17 (G17) displacement and G17-stimulated calcium assays were used in classical CCK-2R-transfected cell lines. Akt phosphorylation was assessed by Western blotting. Z-360 efficacy in vivo was evaluated in three human xenograft models, and microvessel density and apoptosis in these models were investigated by immunohistochemistry.

RESULTS

Z-360 inhibited (125)I G17 binding to cells expressing CCK-2R, and G17-stimulated signalling. Reduced Akt phosphorylation in an oesophageal cell-line treated with Z-360 was reversed by co-treatment with G17. Z-360 increased survival in a gastric ascites model (p=0.011) and decreased tumour growth in a hepatic metastasis model (81%, p=0.02). In an orthotopic pancreatic model, Z-360 combined with gemcitabine decreased final tumour weight compared to single agents (84%, p=0.002) and there was increased apoptosis and decreased microvessel density in ex vivo tumour tissue.

CONCLUSIONS

These results show that the orally-active CCK-2R antagonist, Z-360 has high sub-nM affinity for classical CCK-2R, is well tolerated in vivo and exerts an anti-tumour effect.

A comparison of the effects of gastrin, somatostatin and dopamine receptor ligands on rat gastric enterochromaffin-like cell secretion and proliferation

Gastrin regulates ECL cell histamine release and is a critical determinant of acid secretion. ECL cell secretion and proliferation is inhibited by gastrin antagonists and somatostatin but little is known about the role of dopamine agonists in this process. Since the ECL cell exhibits all three classes of receptor we evaluated and compared the effects of the gastrin receptor antagonist, (YF476), lanreotide (SST agonist) and novel dopaminergic agents (BIM53061 and BIM27A760) on ECL cell histamine secretion and proliferation. Highly enriched (>98%) ECL cell preparations prepared from rat gastric mucosa using a FACS approach were studied. Real-time PCR confirmed presence of the CCK2, SS2 and SS5 and D1 receptors on ECL cells. YF476 inhibited histamine secretion and proliferation with IC(50)s of 1.25 nM and 1.3 x 10(-11) M respectively, values 10-1000x more potent than L365,260. Lanreotide inhibited secretion and proliferation (2.2 nM, 1.9 x 10(-10) M) and increased YF476-inhibited proliferation a further 5-fold. The dopamine agonist, BIM53061, inhibited gastrin-mediated ECL cell secretion and proliferation (17 nM, 6 x 10(-10) M) as did the novel dopamine/somatostatin chimera BIM23A760 (22 nM, 4.9 x 10(-10) M). Our studies demonstrate that the gastrin receptor antagonist, YF476, is the most potent inhibitor of ECL cell histamine secretion and proliferation. Lanreotide, a dopamine agonist and a dopamine/somatostatin chimera inhibited ECL cell function but were 10-1000x less potent than YF476. Agents that selectively target the CCK2 receptor may provide alternative therapeutic strategies for gastrin-mediated gastrointestinal cell secretion and proliferation such as evident in the hypergastrinemic gastric carcinoids associated with low acid states.

Consequences of long-term proton pump blockade: insights from studies of patients with gastrinomas

Proton pump inhibitors are being increasingly used and for longer periods of time, especially in patients with gastroesophageal reflux disease. Each of these trends has led to numerous studies and reviews of the potential risk-benefit ratio of the long-term use of proton pump inhibitors. Both long-term effects of hypergastrinaemia due to the profound acid suppression caused by proton pump inhibitors as well as the effects of hypo-/achlorhydria per se have been raised and studied. Potential areas of concern that have been raised in the long-term use of proton pump inhibitors, which could alter this risk-benefit ratio include: gastric carcinoid formation; the development of rebound acid hypersecretion when proton pump inhibitor treatment is stopped; the development of tolerance; increased oxyntic gastritis in H. pylori patients and the possibility of increasing the risk of gastric cancer; the possible stimulation of growth of non-gastric tumours due to hypergastrinaemia; and the possible effect of the hypo/achlorhydria on nutrient absorption, particularly iron and vitamin B12. Because few patients with idiopathic gastro-oesophageal reflux disease/peptic ulcer disease have been treated long-term (i.e., >10 years), there is little known to address the above areas of potential concern. Most patients with gastrinomas with Zollinger-Ellison syndrome have life-long hypergastrinaemia, require continuous proton pump inhibitors treatment and a number of studies report results of >5-10 years of tratment and follow-up. Therefore, an analysis of Zollinger-Ellison syndrome patients can provide important insights into some of the safety concerns raised above. In this paper, results from studies of Zollinger-Ellison syndrome patients and other recent studies dealing with the safety concerns above, are briefly reviewed.

Constitutively active CCK2 receptor splice variant increases Src-dependent HIF-1 alpha expression and tumor growth

Gastrointestinal (GI) cancers ectopically express multiple splice variants of the cholecystokinin-2 (CCK(2))/gastrin receptor; however, their relative contributions to the cancer phenotype are unknown. The aim of this study was to compare the effects of CCK(2) receptor (CCK(2)R) and CCK(2i4sv)R expression on cell growth both in vitro and in vivo using a human epithelial cell model, HEK239. In vitro, receptor variant expression did not affect cell proliferation either in the absence or presence of agonist. However, in vivo, the expression of CCK(2i4sv)R, but not CCK(2)R, increases HEK293 tumor growth in a constitutive, Src-dependent manner. Enhanced tumorigenicity of CCK(2i4sv)R is associated with an Src-dependent increase in the transcription factor, hypoxia-inducible factor-1alpha, its downstream target, vascular endothelial growth factor and tumor micro-vessel density, suggesting that CCK(2i4sv)R may contribute to the growth and spread of GI cancers through agonist-independent mechanisms that enhance tumor angiogenesis.

Cholecystokinin and gastrin receptors

Cholecystokinin and gastrin receptors (CCK1R and CCK2R) are G protein-coupled receptors that have been the subject of intensive research in the last 10 years with corresponding advances in the understanding of their functioning and physiology. In this review, we first describe general properties of the receptors, such as the different signaling pathways used to exert short- and long-term effects and the structural data that explain their binding properties, activation, and regulation. We then focus on peripheral cholecystokinin receptors by describing their tissue distribution and physiological actions. Finally, pathophysiological peripheral actions of cholecystokinin receptors and their relevance in clinical disorders are reviewed.

Attenuation of Peroxisome Proliferator-activated Receptor γ (PPARγ) Mediates Gastrin-stimulated Colorectal Cancer Cell Proliferation

Peroxisome proliferators-activated receptor gamma (PPARgamma) has been shown to suppress cell proliferation and tumorigenesis, whereas the gastrointestinal regulatory peptide gastrin stimulates the growth of neoplastic cells. The present studies were directed to determine whether changes in PPARgamma expression might mediate the effects of gastrin on the proliferation of colorectal cancer (CRC). Initially, using growth assays, we determined that the human CRC cell line DLD-1 expressed both functional PPARgamma and gastrin receptors. Amidated gastrin (G-17) attenuated the growth suppressing effects of PPARgamma by decreasing PPARgamma activity and total protein expression, in part through an increase in the rate of proteasomal degradation. G-17-induced degradation of PPARgamma appeared to be mediated through phosphorylation of PPARgamma at serine 84 by a process involving the biphasic phosphorylation of ERK1/2 and activation of the epidermal growth factor receptor (EGFR). These results were confirmed through the use of EGFR antagonist AG1478 and MEK1 inhibitor PD98059. Furthermore, mutation of PPARgamma at serine 84 reduced the effects of G-17, as evident by inability of G-17 to attenuate PPARgamma promoter activity, degrade PPARgamma, or inhibit the growth suppressing effects of PPARgamma. The results of these studies demonstrate that the trophic properties of gastrin in CRC may be mediated in part by transactivation of the EGFR and phosphorylation of ERK1/2, leading to degradation of PPARgamma protein and a decrease in PPARgamma activation.

Bile salt exposure increases proliferation through p38 and ERK MAPK pathways in a non-neoplastic Barrett's cell line

Bile reflux has been implicated in the neoplastic progression of Barrett's esophagus (BE). Bile salts increase proliferation in a Barrett's-associated adenocarcinoma cell line (SEG-1 cells) by activating ERK and p38 MAPK pathways. However, it is not clear that these findings in cancer cells are applicable to non-neoplastic cells of benign BE. We examined the effect of bile salts on three human cell lines: normal esophageal squamous (NES) cells, non-neoplastic Barrett's cells (BAR cells), and SEG-1 cells. We hypothesized that bile salt exposure activates proproliferative and antiapoptotic pathways to promote increased growth in BE. NES, BAR, and SEG-1 cells were exposed to glycochenodeoxycholic acid (GCDA) at a neutral pH for 5 min. Proliferation was measured by Coulter counter cell counts and a 5-bromo-2'-deoxyuridine (BrdU) incorporation assay. GCDA-induced MAPK activation was examined by Western blot analysis for phosphorylated ERK and p38. Apoptosis was measured by TdT-mediated dUTP nick-end labeling and annexin V staining after GCDA and UV-B exposure. Statistical significance was determined by ANOVA. NES cells exposed to 5 min of GCDA did not increase cell number. In BAR cells, GCDA exposure increased cell number by 31%, increased phosphorylated p38 and ERK levels by two- to three-fold, increased BrdU incorporation by 30%, and decreased UV-induced apoptosis by 15-20%. In conclusion, in a non-neoplastic Barrett's cell line, GCDA exposure induces proliferation by activation of both ERK and p38 MAPK pathways. These findings suggest a potential mechanism whereby bile reflux may facilitate the neoplastic progression of BE.

New Molecular Concepts of Barrett’s Esophagus: Clinical Implications and Biomarkers

Barrett's esophagus (BE) represents the most serious histological consequence of gastroesophageal reflux disease (GERD) that develops in 5-10% of patients with GERD. Given that BE is the only known precursor to esophageal adenocarcinoma (EA), a systematic endoscopic biopsy protocol can detect EAs at an early stage. However, endoscopic and histopathological evaluation of BE are not adequate for effective screening of high risk patients. Therefore, molecular abnormalities associated with BE have been considered as surrogate markers and their use as such is proposed. Flow cytometry is the most useful adjunct to histology, and ploidy status of BE is an independent risk factor. Cyclin D1 overexpression is inversely correlated with survival in EA. C-erbB2 (+) patients have poorer prognosis. High plasma adenomatous polyposis coli levels correlate with reduced patient survival. p53 expression allows patient risk for EA stratification. Nuclear factor-kappaB overexpression inversely correlates with good response to adjuvant chemotherapy and radiotherapy in EA. Patients with cyclooxygenase-2 overexpression have reduced survival rates. Increased E-cadherin staining is associated with shorter survival in EA patients who received chemoradiotherapy. Finally, existing data cannot rule out a correlation between EA and colorectal tumors. Seventeen BE molecular alterations yielded noteworthy clinical implications. Apart from endoscopy and histology, these data allow for better risk stratification for patients with BE and for more efficient and timely therapeutic approaches.