Proton Pump Inhibitor Associated Multiple Gastric Hyperplastic Polyps With Uncontrollable Bleeding: A Case Report

BACKGROUND/AIM

The long-term use of proton pump inhibitors (PPIs) has been reported to be strongly associated with the development of fundic gland polyps (FGPs). Conversely, a few cases of gastric hyperplastic polyps (GHPs) associated with PPI use have been reported. We experienced a case of PPI-associated multiple GHPs with uncontrollable bleeding.

CASE REPORT

A 64 year old man with a history of rheumatoid arthritis presented to the hospital with complaints of vertigo and black stools. Blood tests revealed anemia and hypoproteinemia. Esophagogastroduodenoscopy (EGD) showed blood and black residue accumulated in the stomach. The source of the bleeding was multiple hyperplastic polyps. Bleeding could be stopped even with fasting, and total blood transfusions amounted to 28 units of RBCs were required in 18 days. After the cessation of PPI, EGD showed that the polyps had almost disappeared. Pathological diagnosis of resected polyp was hyperplastic polyp, which was characterized by capillary hyperplasia and edema. Gastrin receptors were over-expressed in the foveolar epithelium and not in the capillaries. Methotrexate (MTX)-induced portal hypertensive gastroenteropathy was revealed during follow-up. We consider that the effect of portal hypertension may have caused the capillary hyperplasia.

CONCLUSION

Although PPI-related polyps are usually fundic gland polyps and do not cause life-threatening adverse events, we experienced PPI-related GHPs in which hemostasis was difficult to control.

Insights into gastric neuroendocrine tumors burden

Type 1 gastric neuroendocrine tumors (gNETs) are usually small lesions, restricted to mucosal and sub-mucosal layers of corpus and fundus, with low aggressive behavior, for the majority of cases. Nevertheless, some cases present aggressive behavior. The increasing incidence of gNETs brings together a new relevant problem: how to identify potentially aggressive type 1 gNETs. The challenging problem seems to be finding out signs or features able to predict potentially aggressive cases, allowing a tailored approach, since the involved societies dedicated to provide guidelines for management of these neoplasms apparently failed in producing staging systems able to accurately predict prognosis of these tumors. Additionally, it is also important to try to find out explanations for increasing incidence, as well as to identify potential targets aiming to reach better control of this neoplasia. Here, we discuss potential pathways implicated in aggressive behavior, as well as new strategies to improve clinical management of these tumors.

Gastric Hyperplastic Polyps Associated with Proton Pump Inhibitor Use in a Case without a History of Helicobacter pylori Infection

A 56-year-old man with gastroesophageal reflux disease (GERD) was referred to our hospital. Esophagogastroduodenoscopy (EGD) revealed no evidence of any polypoid lesions in the stomach, and the patient had no history of Helicobacter pylori infection. He received omeprazole (20 mg) once daily for the GERD. EGD was performed at 1 year after the start of omeprazole administration, and this time, gastric hyperplastic polyps (GHPs) were detected. The GHPs increased in size as the omeprazole treatment continued, but they markedly decreased in size following omeprazole discontinuation. Thus, the administration of proton pump inhibitors may be a risk factor for the development of GHP independent of H. pylori infection.

Assessment of cholecystokinin 2 receptor (CCK2R) in neoplastic tissue

The expression of cholecystokinin 2 receptor (CCK2R, CCKBR or gastrin receptor) has been reported on a diverse range of cancers such as colorectal, liver, lung, pancreatic, ovarian, stomach, thyroid and numerous neuroendocrine/carcinoid tumors. Some cancers of the colorectum, lung, pancreas and thyroid have been shown to overexpress CCK2R in relation to normal matched tissues of the same organ. This reported overexpression has led to the development of a number of CCK2R-ligand targeted imaging and therapeutic agents. However, no comprehensive study comparing the expression of CCK2R in multiple cancers to multiple normal tissues has been performed. Herein, we report the immunohistochemical analysis of cancer samples from gastrointestinal stromal tumor (GIST), hepatocellular carcinoma (HCC), non-small cell lung cancer (NSCLC), pancreatic adenocarcinoma, and thyroid cancer against multiple normal tissue samples from esophagus, liver, lung, pancreas, stomach, spleen and thyroid. These results show that CCK2R expression is present in nearly all cancer and normal samples tested and that none of the cancer samples had expression that was statistically greater than that of all of the normal samples.

Changes in FABP1 and gastrin receptor expression in the testes of rats that have undergone electrical injury

Testicular trauma may occur due to accidental electrical injury. The aim of this study was to investigate alterations in the levels of fatty acid-binding protein 1 (FABP1) and gastrin receptor (gastrin R) in the testes following electrical injury. Sprague-Dawley rats were divided into control, fatal electrocution (220 V, 50 Hz, 60 sec) and electrical injury (220 V, 50 Hz, 60 sec) groups (n=8 per group). The animals in the fatal electrocution and electrical injury groups were deeply anesthetized with sodium pentobarbital prior to each treatment, in which the current was delivered via an anode connected to the left foreleg and a cathode to the right hindleg. The rats that survived were subsequently sacrificed by cervical dislocation. Control animals received cervical dislocation alone. Immunohistochemical analysis was performed to evaluate the protein expression of FABP1 and gastrin R in the testes. Sections were evaluated by digital image analysis. The expression levels of FABP1 and gastrin R were significantly increased following electrical injury, supported by an increase in the integrated optical density (IOD) when compared with that in the control group (P<0.05). However, no significant difference was found in FABP1 and gastrin R expression levels between the fatal electrocution and control groups. In summary, the protein expression levels of FABP1 and gastrin R were found to be significantly altered by electrical injury, suggesting that these two proteins may be important in underlying mechanisms of testicular injury during electrical injury. The findings indicate that such alterations would be reflected in abnormal testicular function.

Bioconjugation of calcium phosphosilicate composite nanoparticles for selective targeting of human breast and pancreatic cancers in vivo

The early diagnosis of cancer is the critical element in successful treatment and long-term favorable patient prognoses. The high rate of mortality is mainly attributed to the tendency for late diagnoses as symptoms may not occur until the disease has metastasized, as well as the lack of effective systemic therapies. Late diagnosis is often associated with the lack of timely sensitive imaging modalities. The promise of nanotechnology is presently limited by the inability to simultaneously seek, treat, and image cancerous lesions. This study describes the design and synthesis of fluorescent calcium phosphosilicate nanocomposite particles (CPNPs) that can be systemically targeted to breast and pancreatic cancer lesions. The CPNPs are a approximately 20 nm diameter composite composed of an amorphous calcium phosphate matrix doped with silicate in which a near-infrared imaging agent, indocyanine green (ICG), is embedded. In the present studies, we describe and validate CPNP bioconjugation of human holotransferrin, anti-CD71 antibody, and short gastrin peptides via an avidin-biotin or a novel PEG-maleimide coupling strategy. The conjugation of biotinylated human holotransferrin (diferric transferrin) and biotinylated anti-CD71 antibody (anti-transferrin receptor antibody) to avidin-conjugated CPNPs (Avidin-CPNPs) permits targeting of transferrin receptors, which are highly expressed on breast cancer cells. Similarly, the conjugation of biotinylated pentagastrin to Avidin-CPNPs and decagastrin (gastrin-10) to PEG-CPNPs via PEG-maleimide coupling permits targeting of gastrin receptors, which are overexpressed in pancreatic cancer lesions. These bioconjugated CPNPs have the potential to perform as a theranostic modality, simultaneously enhancing drug delivery, targeting, and imaging of breast and pancreatic cancer tumors.

Gastrin activates nuclear factor kappaB (NFkappaB) through a protein kinase C dependent pathway involving NFkappaB inducing kinase, inhibitor kappaB (IkappaB) kinase, and tumour necrosis factor receptor associated factor 6 (TRAF6) in MKN-28 cells transfected with gastrin receptor

BACKGROUND

We previously reported that gastrin induces expression of CXC chemokines through activation of nuclear factor kappaB (NFkappaB) in gastric epithelial cells that express gastrin receptor.

AIMS

To clarify gastrin receptor mediated signals leading to activation of NFkappaB.

METHODS

MKGR26 cells were created by transfecting gastrin receptor cDNA into MKN-28 cells. Degradation of inhibitor kappaB (IkappaB) and phosphorylation of protein kinase C (PKC)-delta were both detected by western blot analysis. NFkappaB activation was determined by luciferase assay and electrophoretic mobility shift analysis.

RESULTS

Gastrin induced degradation of IkappaB-alpha and activation of NFkappaB, which was abolished by the selective gastrin receptor antagonist L-740,093 and the general PKC inhibitor GF109203X. Gastrin induced phosphorylation of PKC-delta, and its inhibitor rottlerin partially suppressed NFkappaB activation. However, the mitogen activated protein kinase (MAPK) kinase inhibitor PD98059, p38 MAPK inhibitor SB203580, and tyrphostin AG1478 had no effect on NFkappaB activation. Introduction of the dominant negative mutant of IkappaB kinase, of NFkappaB inducing kinase, and of tumour necrosis factor receptor associated factor 6 (TRAF6), but not that of TRAF2, inhibited gastrin induced activation of NFkappaB.

CONCLUSIONS

Gastrin activates NFkappaB via a PKC dependent pathway which involves IkappaB kinase, NFkappaB inducing kinase, and TRAF6.

Gastrin receptor gene expression in several human carcinomas

Gastrin has been shown to enhance the growth of various human tumors. The present study was designed to examine the gastrin receptor gene expression in various human carcinoma cell lines and in surgically resected carcinoma tissues. By Northern blot analysis, gastrin receptor mRNA was detected in 3 out of 7 small cell lung carcinoma cell lines. Gastrin receptor mRNA was also expressed in one out of 8 colon carcinoma cell lines and 2 out of 10 colon carcinoma tissues. Moreover, one of two small cell carcinoma cell lines of the stomach clearly expressed gastrin receptor mRNA. However, none of the gastric adenocarcinoma cell lines or surgically resected gastric adenocarcinomas tested had any detectable expression of gastrin receptor gene. These findings may suggest a role of gastrin receptor in the growth and differentiation of certain human carcinomas.