Role of gastrointestinal hormones in the proliferation of normal and neoplastic tissues

Triple synchronous malignancies of the stomach, bladder and thyroid in a previously treated prostate cancer patient: A Case Report

Cancers that develop within six months of the first primary cancer are referred to as synchronous malignancies. These malignancies are difficult to diagnose and treat, with treatment primarily based on case reports.

Effects of hormones on intestinal stem cells

The maintenance of intestinal renewal and repair mainly depends on intestinal stem cells (ISCs), which can also contribute to the growth of intestinal tumours. Hormones, which are vital signalling agents in the body, have various effects on the growth and replacement of intestinal stem cells. This review summarises recent progress in the identification of hormones associated with intestinal stem cells. Several hormones, including thyroid hormone, glucagon-like peptide-2, androgens, insulin, leptin, growth hormone, corticotropin-releasing hormone and progastrin, promote the development of intestinal stem cells. However, somatostatin and melatonin are two hormones that prevent the proliferation of intestinal stem cells. Therefore, new therapeutic targets for the diagnosis and treatment of intestinal illnesses can be identified by examining the impact of hormones on intestinal stem cells.

Maternal adaptations of the pancreas and glucose homeostasis in lactation and after lactation

During lactation, the maternal physiology adapts to bear the nutritional requirements of the offspring. The exocrine and endocrine pancreas are central to nutrient handling, promoting digestion and metabolism. In concert with prolactin, insulin is a determinant factor for milk synthesis. The investigation of the pancreas during lactation has been scattered over several periods. The investigations that laid the foundation of lactating pancreatic physiology and glucose homeostasis were conducted in the decades of 1970-1980. With the development of molecular biology, newer studies have revealed the molecular mechanisms involved in the endocrine pancreas during breastfeeding. There has been a surge of information recently about unexpected changes in the pancreas at the end of the lactation period and after weaning. In this review, we aim to gather information on the changes in the pancreas and glucose homeostasis during and after lactation and discuss the outcomes derived from the current discoveries.

Glucagon-like peptide-2 analogues for Crohn’s disease patients with short bowel syndrome and intestinal failure

Short bowel syndrome (SBS) with intestinal failure (IF) is a rare but severe complication of Crohn’s disease (CD), which is the most frequent benign condition that leads to SBS after repeated surgical resections, even in the era of biologics and small molecules. Glucagon-like peptide-2 analogues have been deeply studied recently for the treatment of SBS-IF. These drugs have a significant intestinotrophic effect and the potential to reduce the chronic dependence of SBS-IF patients on parenteral support or nutrition. Teduglutide has been approved for the treatment of SBS-IF, and apraglutide is currently in clinical development. The use of these drugs was examined with a focus on their use in CD patients.

Compensatory Upregulation of LPA2 and Activation of the PI3K-Akt Pathway Prevent LPA5-Dependent Loss of Intestinal Epithelial Cells in Intestinal Organoids

Renewal of the intestinal epithelium is orchestrated by regenerative epithelial proliferation within crypts. Recent studies have shown that lysophosphatidic acid (LPA) can maintain intestinal epithelial renewal in vitro and conditional deletion of Lpar5 (Lpar5iKO) in mice ablates the intestinal epithelium and increases morbidity. In contrast, constitutive Lpar5 deletion (Lpar5cKO) does not cause a defect in intestinal crypt regeneration. In this study, we investigated whether another LPA receptor (LPAR) compensates for constitutive loss of LPA5 function to allow regeneration of intestinal epithelium. In Lpar5cKO intestinal epithelial cells (IECs), Lpar2 was upregulated and blocking LPA2 function reduced proliferation and increased apoptosis of Lpar5cKO IECs. Similar to Lpar5cKO mice, the absence of Lpar2 (Lpar2-/-) resulted in upregulation of Lpar5 in IECs, indicating that LPA2 and LPA5 reciprocally compensate for the loss of each other. Blocking LPA2 in Lpar5cKO enteroids reduced phosphorylation of Akt, indicating that LPA2 maintains the growth of Lpar5cKO enteroids through activation of the PI3K-Akt pathway. The present study provides evidence that loss of an LPAR can be compensated by another LPAR. This ability to compensate needs to be considered in studies aimed to define receptor functions or test the efficacy of a LPAR-targeting drug using genetically engineered animal models.

Carcinoid ovary with synchronous carcinoid tumour of the appendix: report of a rare occurrence with review of literature

Carcinoid tumours are present in a wide range of organs but most frequently involve the gastrointestinal tract and rarely reported in gynaecological organs. Literature reports that the prevalence of ovarian carcinoid is 0.3%-1% of ovarian neoplasms and accounts for only 5% of ovarian teratomas. The pathogenesis of neuroendocrine tumours associated with synchronous primaries is undetermined and many theories have been proposed, such as existence of a common carcinogenic effect or a common stem cell undergoing similar genetic mutation. Paracrine or autocrine growth loop effect by the secretory peptides of the neuroendocrine cell tumours is also suggested. Since carcinoids are variably positive in neuroendocrine and organ-specific markers, there are no immunohistochemistry markers to delineate the definite primary site of origin versus metastasis. We report a rare case of carcinoid ovary with synchronous carcinoid tumour of the appendix. In our case, the presence of contralateral teratomatous elements may hint primary struma carcinoid instead of being metastatic from the appendix. A strumal carcinoid component was also highlighted by PAX8 positivity. This led us to conclude the case as concurrent appendix carcinoid with struma carcinoid as two independent primaries with uncertain pathogenesis. Histologically, as both tumours are well differentiated with Ki-67 of less than 3%, the decision of the joint tumour board was to keep the patient on surveillance, with no adjuvant treatment needed. The patient is currently on surveillance and the follow-up period of 24 months to date has been uneventful.

Clinical and Biological Significance of DNA Methylation-Driven Differentially Expressed Genes in Biochemical Recurrence After Radical Prostatectomy

Background: Biochemical recurrence (BCR) after radical prostatectomy indicates poor prognosis in patients with prostate cancer (PCA). DNA methylation (DNAm) is a critical factor in tumorigenesis and has attracted attention as a biomarker for the diagnosis, treatment, and prognosis of PCA. However, the predictive value of DNAm-derived differentially expressed genes (DMGs) in PCA with BCR remains elusive.

Methods: We filtered the methylated genes and the differentially expressed genes (DGEs) for more than 1,000 clinical samples from the TCGA cohort using the chAMP and DESeq2 packages of R language, respectively. Next, we integrated the DNAm beta value and gene expression data with the Mithymix package of R language to obtain the DMGs. Then, 1,000 times Cox LASSO regression with 10-fold cross validation was performed to screen signature DMGs and establish a predictive classifier. Univariate and multivariate cox regressive analyses were used to identify the prognostic factors to build a predictive model, and its performance was measured by receiver operating characteristic, calibration curves, and Harrell’s concordance index (C-index). Additionally, a GEO dataset was used to validate the prognostic classifier.

Results: One hundred DMGs were mined using the chAMP and Methymix packages of R language. Of these, seven DMGs (CCK, CD38, CYP27A1, EID3, HABP2, LRRC4, and LY6G6D) were identified to build the prognostic classifier (Classifier) through LASSO analysis. Moreover, univariate and multivariate Cox regression analysis determined that the Classifier and pathological T stage (pathological_T) were independent predictors of BCR (hazard ratio (HR 2.2), (95% CI 1.4–3.5), p < 0.0012, and (HR 1.8), (95% CI 1.0–3.2), p < 0.046). A nomogram based on the Classifier was constructed, with high prediction accuracy for BCR-free survival in TCGA and GEO datasets. GSEA enrichment analysis showed that the DMGs were mainly enriched in the metabolism pathways.

Conclusion: We identified and validated the nomogram of BCR-free survival for PCA patients, which has the potential to guide treatment decisions for patients at differing risks of BCR. Our study deepens the understanding of DMGs in the pathogenesis of PCA.

Energy homeostasis genes modify the association between serum concentrations of IGF-1 and IGFBP-3 and breast cancer risk

Breast cancer is a multifactorial disease in which the interplay among multiple risk factors remains unclear. Energy homeostasis genes play an important role in carcinogenesis and their interactions with the serum concentrations of IGF-1 and IGFBP-3 on the risk of breast cancer have not yet been investigated. The aim of this study was to assess the modifying effect of the genetic variation in some energy homeostasis genes on the association of serum concentrations of IGF-1 and IGFBP-3 with breast cancer risk. We analyzed 78 SNPs from 10 energy homeostasis genes in premenopausal women from the 4-Corner’s Breast Cancer Study (61 cases and 155 controls) and the Mexico Breast Cancer Study (204 cases and 282 controls). After data harmonization, 71 SNPs in HWE were included for interaction analysis. Two SNPs in two genes (MBOAT rs13272159 and NPY rs16131) showed an effect modification on the association between IGF-1 serum concentration and breast cancer risk (P_interaction < 0.05, adjusted P_interaction < 0.20). In addition, five SNPs in three genes (ADIPOQ rs182052, rs822391 and rs7649121, CARTPT rs3846659, and LEPR rs12059300) had an effect modification on the association between IGFBP-3 serum concentration and breast cancer risk (P_interaction < 0.05, adjusted P_interaction < 0.20). Our findings showed that variants of energy homeostasis genes modified the association between the IGF-1 or IGFBP-3 serum concentration and breast cancer risk in premenopausal women. These findings contribute to a better understanding of this multifactorial pathology.

Identification of a novel immune signature for optimizing prognosis and treatment prediction in colorectal cancer

BACKGROUND

Globally, colorectal cancer (CRC) is one of the most lethal malignant diseases. However, the currently approved therapeutic options for CRC failed to acquire satisfactory treatment efficacy. Tailoring therapeutic strategies for CRC individuals can provide new insights into personalized prediction approaches and thus maximize clinical benefits.

METHODS

In this study, a multi-step process was used to construct an immune-related genes (IRGs) based signature leveraging the expression profiles and clinical characteristics of CRC from the Gene Expression Omnibus (GEO) database and the Cancer Genome Atlas (TCGA) database. An integrated immunogenomic analysis was performed to determine the association between IRGs with prognostic significance and cancer genotypes in the tumor immune microenvironment (TIME). Moreover, we performed a comprehensive in silico therapeutics screening to identify agents with subclass-specific efficacy.

RESULTS

The established signature was shown to be a promising biomarker for evaluating clinical outcomes in CRC. The immune risk score as calculated by this classifier was significantly correlated with over-riding malignant phenotypes and immunophenotypes. Further analyses demonstrated that CRCs with low immune risk scores achieved better therapeutic benefits from immunotherapy, while AZD4547, Cytochalasin B and S-crizotinib might have potential therapeutic implications in the immune risk score-high CRCs.

CONCLUSIONS

Overall, this IRGs-based signature not only afforded a useful tool for determining the prognosis and evaluating the TIME features of CRCs, but also shed new light on tailoring CRCs with precise treatment.

Regulation of Neuroendocrine-like Differentiation in Prostate Cancer by Non-Coding RNAs

Neuroendocrine prostate cancer (NEPC) represents a variant of prostate cancer that occurs in response to treatment resistance or, to a much lesser extent, de novo. Unravelling the molecular mechanisms behind transdifferentiation of cancer cells to neuroendocrine-like cancer cells is essential for development of new treatment opportunities. This review focuses on summarizing the role of small molecules, predominantly microRNAs, in this phenomenon. A published literature search was performed to identify microRNAs, which are reported and experimentally validated to modulate neuroendocrine markers and/or regulators and to affect the complex neuroendocrine phenotype. Next, available patients’ expression datasets were surveyed to identify deregulated microRNAs, and their effect on NEPC and prostate cancer progression is summarized. Finally, possibilities of miRNA detection and quantification in body fluids of prostate cancer patients and their possible use as liquid biopsy in prostate cancer monitoring are discussed. All the addressed clinical and experimental contexts point to an association of NEPC with upregulation of miR-375 and downregulation of miR-34a and miR-19b-3p. Together, this review provides an overview of different roles of non-coding RNAs in the emergence of neuroendocrine prostate cancer.

Obesity-related gut hormones and cancer: novel insight into the pathophysiology

The number of cancers attributed to obesity is increasing over time. The mechanisms classically implicated in cancer pathogenesis and progression in patients with obesity involve adiposity-related alteration of insulin, sex hormones, and adipokine pathways. However, they do not fully capture the complexity of the association between obesity-related nutritional imbalance and cancer. Gut hormones are secreted by enteroendocrine cells along the gastrointestinal tract in response to nutritional cues, and act as nutrient sensors, regulating eating behavior and energy homeostasis and playing a role in immune-modulation. The dysregulation of gastrointestinal hormone physiology has been implicated in obesity pathogenesis. For their peculiar function, at the cross-road between nutrients intake, energy homeostasis and inflammation, gut hormones might represent an important but still underestimated mechanism underling the obesity-related high incidence of cancer. In addition, cancer research has revealed the widespread expression of gut hormone receptors in neoplastic tissues, underscoring their implication in cell proliferation, migration, and invasion processes that characterize tumor growth and aggressiveness. In this review, we hypothesize that obesity-related alterations in gut hormones might be implicated in cancer pathogenesis, and provide evidence of the pathways potentially involved.

Protective effect of neurotensin receptor-1 agonist PD 149163 against lipopolysaccharide-induced gut toxicity in mice

The interaction between neuroendocrine and immune components of the gut maintains the organism's physical and psychological health. Its disruption may reflect in disease conditions such as inflammatory bowel disease (IBD) and mental illness. The lipopolysaccharide (LPS) disrupts the endocrine-immune homeostasis resulting in gut toxicity. The Neurotensin receptor-1 (NTR-1) agonist PD 149163 (PD) acts as an atypical antipsychotic drug in psychiatric illness, but its role in modulating gut pathophysiology remains unknown. Therefore, the aim of the present study was to evaluate the protective effect of PD against LPS-induced gut toxicity. Swiss albino female mice (12 weeks) were divided into six groups (n = 6/group): (I) Control, (II) LPS (1 mg/kg, for 5 days), (III) LPS (1 mg/kg, for 5 days)+PD low (100 µg/kg, for 21 days), (IV) LPS (1 mg/kg, for 5 days)+PD high (300 µg/kg, for 21 days), (V) PD low (100 µg/kg, for 21 days), and (VI) PD high (300 µg/kg, for 21 days). Drugs were given intraperitoneal in the morning. PD administration prevented the LPS-induced gut inflammation observed in damage of epithelial barrier, disruption of goblet cells, and condensation of lamina propria (LP). The LPS-induced oxidative stress characterized by decreased superoxide dismutase (SOD) activity and increased lipid hydroperoxide (LOOH) (p < 0.001 for both), and enhanced interleukine-6 (IL-6) & tumor necrosis factor-α (TNF-α) (p < 0.001 for both) as well as immunointensity of NT (p < 0.01) and NTR-1 (p < 0.05) were reversed and normalized to control after PD treatment. Thus, the anti-inflammatory, anti-oxidative, and cell proliferation properties of PD modulate the gut toxicity in LPS-challenged mice.

Neurotensins and their therapeutic potential: research field study

The natural tridecapeptide neurotensin has been emerged as a promising therapeutic scaffold for the treatment of neurological diseases and cancer. In this work, we aimed to identify the top 100 most cited original research papers as well as recent key studies related to neurotensins. The Web of Science Core Collection database was searched and the retrieved research articles were analyzed by using the VOSviewer software. The most cited original articles were published between 1973 and 2013. The top-cited article was by Carraway and Leeman reporting the discovery of neurotensin in 1973. The highly cited terms were associated with hypotension and angiotensin-converting-enzyme. The conducted analysis reveals the therapeutic potentials of neurotensin, and further impactful research toward its clinical development is warrantied.

Functional, Diagnostic and Therapeutic Aspects of Gastrointestinal Hormones

Gastrointestinal (GI) hormones are essential to many physiologic functions in our body. They have many GI and extra-GI functions. Some of the functions of these hormones, which have GI and extra-GI sources, are still unknown. Specific GI hormones can affect the brain to control food intake, while others can proliferate normal and neoplastic tissue when their receptors are expressed in certain neoplasms. GI hormones also have many diagnostic and therapeutic roles. Physiologic and pathophysiologic aspects as well as the diagnostic and therapeutic values of GI hormones are elaborated in this review.

Neuroendocrine neoplasms of gastrointestinal tract and secondary primary synchronous tumors: A systematic review of case reports. Casualty or causality?

BACKGROUND

Neuroendocrine neoplasms (NENs) can arise in most of the epithelial organs of the body and are not a rare condition in the gastrointestinal tract (GIT). The presence of NENs in GIT associated with other secondary primary malignancies (SPM) has been considered an exotic event. This study aims to describe the case reports of NENs accompanied by synchronous primary tumors.

METHODS AND FINDINGS

We performed a systematic literature search of the databases Scopus, PubMed, Scielo and LILACS to identify case reports that described the presence of NENs in GIT with SPM. 78 case reports were included. The mean of age of the cases was 60.2 years. 60% were male. 95.4% were NENs G1. 17 cases of NENs had metastasis. 80% of SPM were recognized in the GIT (36% in stomach, 27% in large intestine, 11.2% in small intestine, and 5.6% in esophagus). The most common type of SPM was adenocarcinoma (49.4%), followed by GIST (13.5%), other NENs in different GIT segment (7.9%), lymphoma (6.8%), and squamous cell carcinoma (4.5%). The most common tumor in GIT was adenocarcinoma (97.6%) and the presence of adenocarcinoma in the same segment of GIT was found in 68.4% of the cases. Association between adenocarcinomas and NENs in GIT (p:<0.0001) and adenocarcinoma and tumor in the same segment of GIT location were observed (p<0.001).

CONCLUSION

These results demonstrate that NENs with SPM are not a rare condition. Several theories have been proposed to explain this association; one of these is the ability of NENs to generate synchronous tumors by autocrine and paracrine effect. We observed an association between adenocarcinomas and NENs in the same segment of GIT.

Noninvasive Biomarkers of Colorectal Cancer: Role in Diagnosis and Personalised Treatment Perspectives

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide. It has been estimated that more than one-third of patients are diagnosed when CRC has already spread to the lymph nodes. One out of five patients is diagnosed with metastatic CRC. The stage of diagnosis influences treatment outcome and survival. Notwithstanding the recent advances in multidisciplinary management and treatment of CRC, patients are still reluctant to undergo screening tests because of the associated invasiveness and discomfort (e.g., colonoscopy with biopsies). Moreover, the serological markers currently used for diagnosis are not reliable and, even if they were useful to detect disease recurrence after treatment, they are not always detected in patients with CRC (e.g., CEA). Recently, translational research in CRC has produced a wide spectrum of potential biomarkers that could be useful for diagnosis, treatment, and follow-up of these patients. The aim of this review is to provide an overview of the newer noninvasive or minimally invasive biomarkers of CRC. Here, we discuss imaging and biomolecular diagnostics ranging from their potential usefulness to obtain early and less-invasive diagnosis to their potential implementation in the development of a bespoke treatment of CRC.

Imaging Neurotensin Receptor in Prostate Cancer With 64Cu-Labeled Neurotensin Analogs

INTRODUCTION

Neurotensin receptor 1 (NTR-1) is expressed and activated in prostate cancer cells. In this study, we explore the NTR expression in normal mouse tissues and study the positron emission tomography (PET) imaging of NTR in prostate cancer models.

MATERIALS AND METHODS

Three ⁶⁴Cu chelators (1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid [DOTA], 1,4,7-triazacyclononane-N,N',N″-triacetic acid [NOTA], or AmBaSar) were conjugated to an NT analog. Neurotensin receptor binding affinity was evaluated using cell binding assay. The imaging profile of radiolabeled probes was compared in well-established NTR⁺ HT-29 tumor model. Stability of the probes was tested. The selected agents were further evaluated in human prostate cancer PC3 xenografts.

RESULTS

All 3 NT conjugates retained the majority of NTR binding affinity. In HT-29 tumor, all agents demonstrated prominent tumor uptake. Although comparable stability was observed, ⁶⁴Cu-NOTA-NT and ⁶⁴Cu-AmBaSar-NT demonstrated improved tumor to background contrast compared with ⁶⁴Cu-DOTA-NT. Positron emission tomography/computed tomography imaging of the NTR expression in PC-3 xenografts showed high tumor uptake of the probes, correlating with the in vitro Western blot results. Blocking experiments further confirmed receptor specificity.

CONCLUSIONS

Our results demonstrated that ⁶⁴Cu-labeled neurotensin analogs are promising imaging agents for NTR-positive tumors. These agents may help us identify NTR-positive lesions and predict which patients and individual tumors are likely to respond to novel interventions targeting NTR-1.

Targeting the gut microbiome to treat the osteoarthritis of obesity

Obesity is a risk factor for osteoarthritis (OA), the greatest cause of disability in the US. The impact of obesity on OA is driven by systemic inflammation, and increased systemic inflammation is now understood to be caused by gut microbiome dysbiosis. Oligofructose, a nondigestible prebiotic fiber, can restore a lean gut microbial community profile in the context of obesity, suggesting a potentially novel approach to treat the OA of obesity. Here, we report that - compared with the lean murine gut - obesity is associated with loss of beneficial Bifidobacteria, while key proinflammatory species gain in abundance. A downstream systemic inflammatory signature culminates with macrophage migration to the synovium and accelerated knee OA. Oligofructose supplementation restores the lean gut microbiome in obese mice, in part, by supporting key commensal microflora, particularly Bifidobacterium pseudolongum. This is associated with reduced inflammation in the colon, circulation, and knee and protection from OA. This observation of a gut microbiome-OA connection sets the stage for discovery of potentially new OA therapeutics involving strategic manipulation of specific microbial species inhabiting the intestinal space.

A Review of the Role of Neurotensin and Its Receptors in Colorectal Cancer

Neurotensin (NTS) is a physiologically occurring hormone which affects the function of the gastrointestinal (GI) tract. In recent years, NTS, acting through its cellular receptors (NTSR), has been implicated in the carcinogenesis of several cancers. In colorectal cancer (CRC), a significant body of evidence, from in vitro and in vivo studies, is available which elucidates the molecular biology of NTS/NTSR signalling and the resultant growth of CRC cells. There is growing clinical data from human studies which corroborate the role NTS/NTSR plays in the development of human CRC. Furthermore, blockade and modulation of the NTS/NTSR signalling pathways appears to reduce CRC growth in cell cultures and animal studies. Lastly, NTS/NTSR also shows potential of being utilised as a diagnostic biomarker for cancers as well as targets for functional imaging. We summarise the existing evidence and understanding of the role of NTS and its receptors in CRC.

The novel enterochromaffin marker Lmx1a regulates serotonin biosynthesis in enteroendocrine cell lineages downstream of Nkx2.2

Intestinal hormone-producing cells represent the largest endocrine system in the body, but remarkably little is known about enteroendocrine cell type specification in the embryo and adult. We analyzed stage- and cell type-specific deletions of Nkx2.2 and its functional domains in order to characterize its role in the development and maintenance of enteroendocrine cell lineages in the mouse duodenum and colon. Although Nkx2.2 regulates enteroendocrine cell specification in the duodenum at all stages examined, it controls the differentiation of progressively fewer enteroendocrine cell populations when deleted from Ngn3(+) progenitor cells or in the adult duodenum. During embryonic development Nkx2.2 regulates all enteroendocrine cell types, except gastrin and preproglucagon. In developing Ngn3(+) enteroendocrine progenitor cells, Nkx2.2 is not required for the specification of neuropeptide Y and vasoactive intestinal polypeptide, indicating that a subset of these cell populations derive from an Nkx2.2-independent lineage. In adult duodenum, Nkx2.2 becomes dispensable for cholecystokinin and secretin production. In all stages and Nkx2.2 mutant conditions, serotonin-producing enterochromaffin cells were the most severely reduced enteroendocrine lineage in the duodenum and colon. We determined that the transcription factor Lmx1a is expressed in enterochromaffin cells and functions downstream of Nkx2.2. Lmx1a-deficient mice have reduced expression of Tph1, the rate-limiting enzyme for serotonin biosynthesis. These data clarify the function of Nkx2.2 in the specification and homeostatic maintenance of enteroendocrine populations, and identify Lmx1a as a novel enterochromaffin cell marker that is also essential for the production of the serotonin biosynthetic enzyme Tph1.

The significance of NTR1 expression and its correlation with β-catenin and EGFR in gastric cancer

BACKGROUND

Several reports indicate the high-affinity receptor of NT (neurotensin), NTR1 (neurotensin receptor 1), in numerous detrimental functions linked to neoplastic progression of several cancer types. Recently, it has also been shown that NTR1 gene is a target of the Wnt/APC oncogenic pathways connected with the β-catenin/Tcf transcriptional complex and NT can stimulate cancer proliferation in an EGFR-dependent mechanism. In this study, we explored NTR1, β-catenin and EGFR expression in gastric cancer. The possible associations of NTR1 expression with clinicopathological factors, prognosis, β-catenin and EGFR were analyzed.

METHODS

NTR1, β-catenin and EGFR expression in gastric cancer tissues and the adjacent normal tissues of 210 cases was detected by Immunohistochemistry. The possible associations of NTR1 expression with clinicopathological data, prognosis, β-catenin and EGFR were analyzed.

RESULTS

1. NTR1 expression in tumor tissues was significantly higher than that in adjacent normal tissues (P <0 .01). 2. Its expression was positively correlated with pathological grade, T stage, N stage and TNM stage and was not correlated with sex, age, tumor size and Lauren's classification. 3. A co-expression of NTR1 and nuclear β-catenin was in 53 (25.2 %) of cases and NTR1 expression was positively correlated with β-catenin nuclear translocation. NTR1 expression was not correlated with EGFR expression, but at a critical value (P = 0.05). 4. By log-rank test, higher expression of NTR1, higher pathological grade, diffusion Lauren's classification and advanced TNM stage showed worse prognosis (P <0 .05). Age, sex, tumor size, β-catenin and EGFR had no prognostic significance. Multivariate Cox analysis showed that NTR1 expression and TNM clinical stage (P <0 .05) were the independent prognostic factors for patients with GC.

CONCLUSION

By immunohistochemistry, we found that a high expression of NTR1 in GC specimens, which showed a bad prognosis, besides, NTR1 expression was related to invasion and migration of GC. These findings provide new and important information on the progression of GC. This study indicated that NTR1 may play an important role in tumor progression of GC and have its potential to be a predictive biomarker or a therapeutic molecular target in GC. The interaction between NTR1 and β-catenin may participate in the development of GC. However, the relationship between NTR1 and EGFR needs to be further investigated.

Neurotensin (NTS) and its receptor (NTSR1) causes EGFR, HER2 and HER3 over-expression and their autocrine/paracrine activation in lung tumors, confirming responsiveness to erlotinib

Alterations in the signaling pathways of epidermal growth factor receptors (HERs) are associated with tumor aggressiveness. Neurotensin (NTS) and its high affinity receptor (NTSR1) are up regulated in 60% of lung cancers. In a previous clinical study, NTSR1 overexpression was shown to predict a poor prognosis for 5 year overall survival in a selected population of stage I lung adenocarcinomas treated by surgery alone. In a second study, shown here, the frequent and high expression of NTSR1 was correlated with a pejorative prognosis in 389 patients with stage I to III lung adenocarcinoma, and was an independent prognosis marker. Interactions between NTS and NTSR1 induce pro-oncogenic biological effects associated with neoplastic processes and tumor progression. Here we highlight the cellular mechanisms activated by Neurotensin (NTS) and its high affinity receptor (NTSR1) contributing to lung cancer cell aggressiveness. We show that the NTS autocrine and/or paracrine regulation causes EGFR, HER2, and HER3 over-expression and activation in lung tumor cells. The EGFR and HER3 autocrine activation is mediated by MMP1 activation and EGF "like" ligands (HB-EGF, Neuregulin 1) release. By establishing autocrine and/or paracrine NTS regulation, we show that tumor growth is modulated according to NTS expression, with a low growth rate in those tumors that do not express NTS. Accordingly, xenografted tumors expressing NTS and NTSR1 showed a positive response to erlotinib, whereas tumors void of NTSR1 expression had no detectable response. This is consistent with the presence of a NTS autocrine loop, leading to the sustained activation of EGFR and responsible for cancer aggressiveness. We propose the use of NTS/NTSR1 tumor expression, as a biomarker for the use of EGFR tyrosine kinase inhibitors in patients lacking EGFR mutation.

The use of peptide analogs for the treatment of gastrointestinal, pancreatic, liver and urinary bladder cancers

Peptide hormones can influence the development and growth of many cancers which are not considered classical hormone-dependent tumors. Analogs of somatostatin, bombesin/gastrin-releasing peptide (GRP), luteinizing hormone-releasing hormone (LH-RH) and growth hormone-releasing hormone (GH-RH) can interfere with receptors on tumor cells or intracellular pathways that are important in cell proliferation and in this way inhibit tumor growth. The first part of this review explains how these peptide hormones and their analogs affect tumors. The second part of this review describes how various hormone analogs can be used for the treatment of gastric, colorectal, pancreatic, liver and urinary bladder cancers. These tumors are major health problems worldwide and their treatment remains a great challenge. Receptors for somatostatin, bombesin/GRP, LH-RH and GH-RH are present in a large percentage of these cancers. We have developed a series of cytotoxic peptides based on doxorubicin or its derivative 2-pyrrolino-doxorubicin coupled to an analog of LH-RH, somatostatin or bombesin. This new class of targeted analogs might provide a more effective therapy for various cancers that express receptors for these carrier peptides, while producing significantly reduced peripheral toxicity. Under experimental conditions, these peptide hormone analogs strongly inhibited the growth of these tumors. Cytotoxic analogs were particularly effective on tumors that express the specific peptide receptors and acted more powerfully than the carrier peptide or the cytotoxic compound alone. Clinical trials on these peptide analogs are in progress.

Neurotensin receptors in pancreatic ductal carcinomas

BACKGROUND

The frequent expression of neurotensin receptors (NT-R) in primaries of pancreatic ductal carcinomas has triggered the development of radioactive neurotensin analogs for possible in vivo targeting of these tumors. However, the complete lack of information regarding NT-R in liver metastases of pancreatic cancer and pancreatic intraepithelial neoplasia (PanIN) makes an in vitro study of NT-R in these tissues indispensable.

METHODS

Using in vitro receptor autoradiography with (125)I-[Tyr(3)]-neurotensin, NT-R were investigated in 18 primaries and 23 liver metastases of pancreatic ductal carcinomas as well as in 19 PanIN lesions.

RESULTS

We report here that 13 of 18 ductal carcinoma primaries and 14 of 23 liver metastases expressed NT-R. Moreover, none of the six PanIN 1B cases expressed NT-R, while two of six PanIN 2 and five of seven PanIN 3 expressed NT-R. Binding was fully displaced by the type 1 NT-R-selective antagonist SR48692, indicating that the NT-R in the tumors are of the type 1 NT-R subtype.

CONCLUSIONS

These in vitro data extend the currently available information on NT-R in invasive and non-invasive pancreatic ductal tumors. They suggest that type 1 NT-R may be a novel, specific marker of PanIN of higher degree. The high expression of NT-R in primaries and metastases of invasive cancer strongly support the need to develop radioactive neurotensin analogs for the diagnosis and therapy of this tumor type.

The potential of neurotensin secreted from neuroendocrine tumor cells to promote gelsolin-mediated invasiveness of prostate adenocarcinoma cells

Neuroendocrine (NE) cells in prostate cancer have been shown to be associated with the progression of prostate cancer. However, little is known about the molecular basis of this association. We have previously demonstrated that NE cells promote metastasis of a human prostate cancer cell line (LNCaP) with overexpression of the gelsolin gene. The purpose of this study was to investigate the interactions between NE cells and LNCaP cells and the involvement of gelsolin in contributing to the invasive potential of LNCaP cells. In addition, we examined whether neurotensin induced gelsolin-mediated invasion. We used the NE cell line NE-CS that was established from the prostate of the LPB-Tag 12T-10 transgenic mouse. Small interfering RNA (siRNA) targeting gelsolin or not targeting it was transfected into LNCaP cells. Cell invasion was assessed by Matrigel invasion assay. The supernatant of NE-CS cells and neurotensin induced the transformation of LNCaP cells. Neurotensin was observed in the supernatant of NE-CS cells but not in LNCaP cells. The siRNA targeting of gelsolin resulted in inhibition of invasion of LNCaP cells in the culture medium with neurotensin added, and in the supernatant of NE-CS cells with epidermal growth factor. The invasive potential of LNCaP cells enhanced by neurotensin or the supernatant of NE-CS cells through neurotensin receptor 1 (NTSR1) was blocked by a phospholipase Cγ inhibitor and an intracellular calcium chelator, with concomitant gelsolin suppression. This study indicates that NE cells and neurotensin induce gelsolin-mediated invasion of LNCaP cells through NTSR1 activation.

Promoter hypermethylation-related reduced somatostatin production promotes uncontrolled cell proliferation in colorectal cancer

BACKGROUND

Somatostatin (SST) has anti-proliferative and pro-apoptotic effects. Our aims were to analyze and compare the SST expression during normal aging and colorectal carcinogenesis at mRNA and protein levels. Furthermore, we tested the methylation status of SST in biopsy samples, and the cell growth inhibitory effect of the SST analogue octreotide in human colorectal adenocarcinoma cell line.

METHODS

Colonic samples were collected from healthy children (n1 = 6), healthy adults (n2 = 41) and colorectal cancer patients (CRCs) (n3 = 34) for SST mRNA expression analysis, using HGU133 Plus2.0 microarrays. Results were validated both on original (n1 = 6; n2 = 6; n3 = 6) and independent samples ((n1 = 6; n2 = 6; n3 = 6) by real-time PCR. SST expressing cells were detected by immunohistochemistry on colonic biopsy samples (n1 = 14; n2 = 20; n3 = 23). The effect of octreotide on cell growth was tested on Caco-2 cell line. SST methylation percentage in biopsy samples (n1 = 5; n2 = 5; n3 = 9) was defined using methylation-sensitive restriction enzyme digestion.

RESULTS

In case of normal aging SST mRNA expression did not alter, but decreased in cancer (p < 0.05). The ratio of SST immunoreactive cells was significantly higher in children (0.70% ± 0.79%) compared to CRC (0% ± 0%) (p < 0.05). Octreotide significantly increased the proportion of apoptotic Caco-2 cells. SST showed significantly higher methylation level in tumor samples (30.2% ± 11.6%) compared to healthy young individuals (3.5% ± 1.9%) (p < 0.05).

CONCLUSIONS

In cancerous colonic mucosa the reduced SST production may contribute to the uncontrolled cell proliferation. Our observation that in colon cancer cells octreotide significantly enhanced cell death and attenuated cell proliferation suggests that SST may act as a regulator of epithelial cell kinetics. The inhibition of SST expression in CRC can be epigenetically regulated by promoter hypermethylation.

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.

Intestinal gene expression profiles of piglets benefit from maternal supplementation with a yeast mannan-rich fraction during gestation and lactation

The objective was to study the effect of maternal supplementation with a yeast cell wall-based product containing a mannan-rich fraction (MRF) during gestation and lactation on piglet intestinal gene expression. First parity sows were fed experimental gestation and lactation diets with or without MRF (900 mg/kg). After farrowing, piglets were fostered within treatment, as necessary. Sow and litter production performance data were collected until weaning. On day 10 post farrowing, jejunum samples from piglets were collected for gene expression analysis using the Affymetrix Porcine GeneChip array. Most performance parameters did not differ between the treatments. However, protein (P<0.01), total solids less fat (P<0.03) and the concentration of immunoglobulin G (IgG) in milk were greater (P<0.05) in the MRF-supplemented group. Gene expression results using hierarchical clustering revealed an overall dietary effect. Further analysis elucidated activation of pathways involved in tissue development, functioning and immunity, as well as greater cell proliferation and less migration of cells in the jejunum tissue. In conclusion, feeding the sow MRF during pregnancy and lactation was an effective nutritional strategy to bolster colostrum and milk IgG that are essential for development of piglet immune system and gut. In addition, the gene expression patterns affected by the passive immunity transfer showed indicators that could benefit animal performance long term.

Pharmacological dose of melatonin reduces cytosolic calcium load in response to cholecystokinin in mouse pancreatic acinar cells

Intracellular Ca(2+) overload has been considered a common pathological precursor of pancreatic injury. In this study, the effects of melatonin on Ca(2+) mobilization induced by cholecystokinin octapeptide (CCK-8) in freshly isolated mouse pancreatic acinar cells have been examined. Changes in intracellular free Ca(2+) concentration were followed by single cell fluorimetry. For this purpose, cells were loaded with the Ca(2+)-sensitive fluorescent dye fura-2-acetoxymethyl ester. In order to evaluate the contribution of Ca(2+) transport at the plasma membrane, at the endoplasmic reticulum (ER) or at the mitochondria, cells were incubated with CCK-8 alone or in combination with LaCl3, thapsigargin (Tps), or FCCP to, respectively, uncouple Ca(2+) transport at these localizations. The experiments were performed in the absence or in the presence of melatonin in combination with the stimuli mentioned. Our results show that the total Ca(2+) mobilization evoked by CCK-8 was attenuated by a 30% in the presence of 100 µM melatonin compared with the responses induced by CCK-8 alone. Upon inhibition of Ca(2+) transport into the ER by Tps, Ca(2+) mobilization was also reduced in the presence of melatonin. In the presence of LaCl3 plus melatonin, the total Ca(2+) mobilization induced by CCK-8 was significantly decreased, compared with the response obtained without melatonin but in the presence of LaCl3. No major differences were found when the cells were incubated with CCK-8 or Tps alone or in combination with LaCl3 plus melatonin and FCCP, compared with the responses obtained in the absence of FCCP. The initial Ca(2+) release from intracellular stores evoked by CCK-8 or Tps was not significantly reduced in the presence of melatonin. The effect of melatonin could be explained on the basis of a stimulated Ca(2+) transport out of the cell through the plasma membrane and by a stimulation of Ca(2+) reuptake into the ER. Accumulation of Ca(2+) into mitochondria might not be a major mechanism stimulated by melatonin. We conclude that melatonin alleviates intracellular Ca(2+) accumulation, a situation potentially leading to cell damage in the exocrine pancreas.

Differential expression of cholecystokinin A receptor in gallbladder cancer in the young and elderly suggests two subsets of the same disease?

Background. Cholecystokinin type A receptor (CCKAR) is known to be overexpressed in variety of human malignancies but information regarding its expression in gallbladder cancer (GBC) is limited. Attempts were now made to investigate expression pattern of CCKAR mRNA and protein in controls and GBC patients and correlate it with various clinicopathological parameters following surgical resection. Materials and Methods. Gallbladder tissue samples from 64 subjects (GBC: 39; control: 25) were studied. Expression of CCKAR mRNA was evaluated by reverse transcriptase-polymerase chain reaction and confirmed using real-time polymerase chain reaction. Protein expression was studied by enzyme-linked immunosorbent assay. Results. Significantly higher expression of CCKAR mRNA (P < 0.0001) and protein (P < 0.0001) was observed in GBC tissues. Overexpression was also observed for stage III and in moderately and poorly differentiated tumors. When the clinicopathological parameters were compared, we found age dependent decrease in CCKAR expression. Relatively higher expression of CCKAR was observed in younger patients (age < 45 years) having more aggressive disease when compared with elderly ones (age ≥ 45 years). Conclusions. Age related differential expression of CCKAR in GBC may suggest two possible variants of the disease in this endemic belt.

Elucidating the role of neurotensin in the pathophysiology and management of major mental disorders

Neurotensin (NT) is a neuropeptide that is closely associated with, and is thought to modulate, dopaminergic and other neurotransmitter systems involved in the pathophysiology of various mental disorders. This review outlines data implicating NT in the pathophysiology and management of major mental disorders such as schizophrenia, drug addiction, and autism. The data suggest that NT receptor analogs have the potential to be used as novel therapeutic agents acting through modulation of neurotransmitter systems dys-regulated in these disorders.

Pathophysiology of short bowel syndrome: considerations of resected and residual anatomy

The human small intestine is organized with a proximal-to-distal gradient of mucosal structure and nutrient processing capacity. However, certain nutrients undergo site-specific digestion and absorption, such as iron and folate in the duodenum/jejunum vs vitamin B12 and bile salts in the ileum. Intestinal resection can result in short bowel syndrome (SBS) due to reduction of total and/or site-specific nutrient processing areas. Depending on the segment(s) of intestine resected, malabsorption can be nutrient specific (eg, vitamin B12 or fat) or sweeping, with deficiencies in energy, protein, and various micronutrients. Jejunal resections are generally better tolerated than ileal resections because of greater postresection adaptive capacity than that of the jejunum. Following intestinal resection, energy scavenging and fluid absorption become particularly important in the colon owing to loss of digestive and absorptive surface area in the resection portion. Resection-induced alterations in enteroendocrine cell abundance can further disrupt intestinal function. For example, patients with end jejunostomy have depressed circulating peptide YY and glucagon-like peptide 2 concentrations, which likely contribute to the rapid intestinal transit and blunted intestinal adaptation observed in this population. SBS-associated pathophysiology often extends beyond the gastrointestinal tract, with hepatobiliary disease, metabolic bone disease, D-lactic acidosis, and kidney stone formation being chronic complications. Clinical management of SBS must be individualized to account for the specific nutrient processing deficit within the remnant bowel and to mitigate potential complications, both inside and outside the gastrointestinal tract.

Melatonin modulates Ca2+ mobilization and amylase release in response to cholecystokinin octapeptide in mouse pancreatic acinar cells

In the present work, we have evaluated the effect of an acute addition of melatonin on cholecystokinin octapeptide (CCK-8)-evoked Ca(2+) signals and amylase secretion in mouse pancreatic acinar cells. For this purpose, freshly isolated mouse pancreatic acinar cells were loaded with fura-2 to study intracellular free Ca(2+) concentration ([Ca(2+)](c)). Amylase release and cell viability were studied employing colorimetric methods. Our results show that CCK-8 evoked a biphasic effect on amylase secretion, finding a maximum at a concentration of 0.1 nM and a reduction of secretion at higher concentrations. Pre-incubation of cells with melatonin (1 μM-1 mM) significantly attenuated enzyme secretion in response to high concentrations of CCK-8. Stimulation of cells with 1 nM CCK-8 led to a transient increase in [Ca(2+)](c), followed by a decrease towards a constant level. In the presence of 1 mM melatonin, stimulation of cells with CCK-8 resulted in a smaller [Ca(2+)](c) peak response, a faster rate of decay of [Ca(2+)](c) and lower values for the steady state of [Ca(2+)](c), compared with the effect of CCK-8 alone. Melatonin also reduced the oscillatory pattern of Ca(2+) mobilization evoked by a physiological concentration of CCK-8 (20 pM), and completely inhibited Ca(2+) mobilization induced by 10 pM CCK-8. On the other hand, Ca(2+) entry from the extracellular space was not affected in the presence of melatonin. Finally, melatonin alone did not change cell viability. We conclude that melatonin, at concentrations higher than those found in blood, might regulate exocrine pancreatic function via modulation of Ca(2+) signals.

Combination of gastrin-releasing peptide antagonist with cytotoxic agents produces synergistic inhibition of growth of human experimental colon cancers

We investigated the efficacy of a powerful antagonist of bombesin/gastrin-releasing peptide (BN/GRP) RC-3940-II administered as a single agent or in combination with cytotoxic agents on the growth of HT-29, HCT-116 and HCT-15 human colon cancer in vitro and in vivo. GRP-receptor mRNA and protein were found in all three cell lines tested. Exposure of HT-29 cells to 10 μM RC-3940-II led to an increase in the number of cells blocked in S phase and G 2/M and cells with lower G(0)/G(1) DNA content. Similar changes on the cell cycle traverse of HT-29 cells could also be seen at lower concentrations of RC-3940-II (1 μM) after pretreatment with 100 nM GRP (14-27), indicating a dose-dependent mechanism of action based on the blockage of BN/GRP induced proliferation of tumor cells at lower concentrations. Daily in vivo treatment with BN/GRP antagonist RC-3940-II decreased the volume of HT-29, HCT-116 and HCT-15 tumors xenografted into athymic nude mice by 25 to 67% (p < 0.005). Combined treatment with RC-3940-II and chemotherapeutic agents 5-FU and irinotecan resulted in a synergistic tumor growth suppression of HT-29, HCT-116 and HCT-15 xenografts by 43% to 78%. In HT-29 and HCT-116 xenografts the inhibition for the combinations of RC-3940-II and irinotecan vs. single substances (p < 0.05) was significantly greater. These findings support the use of RC-3940-II as an anticancer agent and may help to design clinical trials using RC-3940-II in combinations with cytotoxic agents.

Neurotensin and its receptors in the control of glucose homeostasis

The pharmacological roles of the neuropeptide neurotensin through its three known receptors are various and complex. Neurotensin is involved in several important biological functions including analgesia and hypothermia in the central nervous system and also food intake and glucose homeostasis in the periphery. This review focuses on recent works dealing with molecular mechanisms regulating blood glucose level and insulin secretion upon neurotensin action. Investigations on crucial cellular components involved in the protective effect of the peptide on beta cells are also detailed. The role of xenin, a neurotensin-related peptide, on the regulation of insulin release by glucose-dependent insulinotropic polypeptide is summarized. The last section comments on the future research areas which should be developed to address the function of new effectors of the neurotensinergic system in the endocrine pancreas.

Neurotensin and its high affinity receptor 1 as a potential pharmacological target in cancer therapy

Cancer is a worldwide health problem. Personalized treatment represents a future advancement for cancer treatment, in part due to the development of targeted therapeutic drugs. These molecules are expected to be more effective than current treatments and less harmful to normal cells. The discovery and validation of new targets are the foundation and the source of these new therapies. The neurotensinergic system has been shown to enhance cancer progression in various cancers such as pancreatic, prostate, lung, breast, and colon cancer. It also triggers multiple oncogenic signaling pathways, such as the PKC/ERK and AKT pathways. In this review, we discuss the contribution of the neurotensinergic system to cancer progression, as well as the regulation and mechanisms of the system in order to highlight its potential as a therapeutic target, and its prospect for its use as a treatment in certain cancers.

Cinnamtannin B-1, a natural antioxidant that reduces the effects of H(2)O(2) on CCK-8-evoked responses in mouse pancreatic acinar cells

This work was designed in order to gain an insight on the mechanisms by which antioxidants prevent pancreatic disorders. We have examined the properties of cinnamtannin B-1, which belongs to the class of polyphenols, against the effect of hydrogen peroxide (H(2)O(2)) in mouse pancreatic acinar cells. We have studied Ca(2+) mobilization, oxidative state, amylase secretion, and cell viability of cells treated with cinnamtannin B-1 in the presence of various concentrations of H(2)O(2). We found that H(2)O(2) (0.1-100 μM) increased CM-H(2)DCFDA-derived fluorescence, reflecting an increase in oxidation. Cinnamtannin B-1 (10 μM) reduced H(2)O(2)-induced oxidation of CM-H(2)DCFDA. CCK-8 induced oxidation of CM-H(2)DCFDA in a similar way to low micromolar concentrations of H(2)O(2), and cinnamtannin B-1 reduced the oxidant effect of CCK-8. In addition, H(2)O(2) induced a slow and progressive increase in intracellular free Ca(2+) concentration ([Ca(2+)](c)). Cinnamtannin B-1 reduced the effect of H(2)O(2) on [Ca(2+)](c), but only at the lower concentrations of the oxidant. H(2)O(2) inhibited amylase secretion in response to cholecystokinin, and cinnamtannin B-1 reduced the inhibitory action of H(2)O(2) on enzyme secretion. Finally, H(2)O(2) reduced cell viability, and the antioxidant protected acinar cells against H(2)O(2). In conclusion, the beneficial effects of cinnamtannin B-1 appear to be mediated by reducing the intracellular Ca(2+) overload and intracellular accumulation of digestive enzymes evoked by ROS, which is a common pathological precursor that mediates pancreatitis. Our results support the beneficial effect of natural antioxidants in the therapy against oxidative stress-derived deleterious effects on cellular physiology.

Expression profile of cholecystokinin type-A receptor in gallbladder cancer and gallstone disease

BACKGROUND

Regulatory peptide receptors have attracted the interest of oncologists as a new promising approach for cancer pathology, imaging and therapy. Although cholecystokinin (CCK) is a potent modulator of gallbladder contractility and plays a potential role in pancreatic carcinogenesis through CCK type-A receptor (CCKAR), its role in gallbladder cancer (GBC) is still unknown and immunohistochemical detection of CCKAR in the gallbladder has not yet been reported. This novel case-control study aimed to investigate the expression profile of CCKAR in GBC and gallstone disease (GSD).

METHODS

This study included 162 samples of gallbladder: 94 from GBC and 68 from GSD. Expression of CCKAR was analyzed by immunohistochemistry and immunoblotting. The results were statistically correlated with disease history including age, sex, presence of gallstone, stage and differentiation.

RESULTS

CCKAR was positive in 30/68 (44.1%) of GSD and 72/94 (76.6%) of GBC samples. Fifty-one of the 72 (70.8%) CCKAR-positive GBC samples showed over-expression. Interestingly, consistent results also appeared in the immunoblotting study.

CONCLUSIONS

CCKAR expression was significantly increased in GBC compared to GSD. Moreover, CCKAR expression was associated with the degree of tumor differentiation, i.e., less expression in poorly-differentiated tumors. Thus, it has future prognostic and therapeutic implications in the management of GBC.

Novel DOTA-neurotensin analogues for 111In scintigraphy and 68Ga PET imaging of neurotensin receptor-positive tumors

Overexpression of the high affinity neurotensin receptor 1 (NTSR1), demonstrated in several human cancers, has been proposed as a new marker for human ductal pancreatic carcinoma and as an independent factor for poor prognosis for ductal breast cancer, head and neck squamous cell carcinoma, and non-small cell lung cancer. The aim of the present study was to develop new DOTA-neurotensin analogues for positron emission tomography (PET) imaging with (68)Ga and for targeted radiotherapy with (90)Y or (177)Lu. We synthesized a DOTA-neurotensin analogue series. Two of these peptides bear two sequence modifications for metabolic stability: DOTA-NT-20.3 shares the same peptide sequence as the previously described DTPA-NT-20.3. In the sequence of DOTA-NT-20.4, the Arg(8)-Arg(9) bond was N-methylated instead of the Pro(7)-Arg(8) bond in DOTA-NT-20.3. An additional sequence modification was introduced in DOTA-LB119 to increase stability. A spacer was added between DOTA and the peptide sequence to increase affinity. Binding to HT29 cells, which express NTSR1, in vivo stability, and biodistribution of the various analogues were compared, and the best candidate was used to image tumors of various sizes with the microPET in mice. (111)In-DOTA-NT-20.3, in spite of a relatively high uptake in kidneys, showed specific tumor uptake and elevated tumor to other organ uptake ratios. High contrast images were obtained at early time points after injection that allowed tumor detection at a time interval postinjection appropriate for imaging with the short-lived radionuclide (68)Ga. (111)In-DOTA-NT-20.4 displayed inferior binding to HT29 cells and reduced tumor uptake. (111)In-DOTA-LB119 displayed at early time points a significantly lower renal uptake but also a lower tumor uptake than (111)In-DOTA-NT-20.3, although binding to HT29 cells was similar. (68)Ga-DOTA-NT-20.3 displayed higher tumor uptake than (68)Ga-DOTA-LB119 and allowed the detection of very small tumors by PET. In conclusion, DOTA-NT-20.3 is a promising candidate for (68)Ga-PET imaging of neurotensin receptor-positive tumors. DOTA-NT-20.3 may also be considered for therapy, as the yttrium-labeled peptide has higher affinity than that of the indium-labeled one. A prerequisite for therapeutic application of this neurotensin analogue would be to lower kidney uptake, for example, by infusion of basic amino acids, gelofusin, or albumin fragments, to prevent nephrotoxicity, as with radiolabeled somatostatin analogues.

Dependence of Relative Expression of NTR1 and EGFR on Cell Density and Extracellular pH in Human Pancreatic Cancer Cell Lines

Pancreatic adenocarcinoma is a devastating disease characterized by early dissemination and poor prognosis. These solid tumors express receptors for neuropeptides like neurotensin (NT) or epidermal growth factor (EGF) and exhibit acidic regions when grown beyond a certain size. We previously demonstrated increases in intracellular Ca2+ levels, intracellular pH and interleukin-8 (IL-8) secretion in BxPC-3 and PANC-1 pancreatic cancer cells in response to a stable NT analog. The present study aimed at investigation of the dependence of the relative expression of NT receptor 1 (NTR1) and EGFR in BxPC-3 and MIA PaCa-2 cells on cell density and extracellular pH (pHe). MTT assays revealed the NTR1 inhibitor SR 142948-sensitive Lys8-ψ-Lys9NT (8-13)-induced proliferation in BxPC-3 and PANC-1 cells. Confluent cultures of BxPC3 and HT-29 lines exhibited highest expression of NTR1 and lowest of EGFR and expression of NTR1 was maximal at slightly acidic pHe. IL-8 production was stimulated by Lys8-ψ-Lys9NT (8-13) and even enhanced at both acidic and alkaline pHe in BxPC-3 and PANC-1 cells. In conclusion, our in vitro study suggests that one contributing factor to the minor responses obtained with EGFR-directed therapy may be downregulation of this receptor in tumor cell aggregates, possibly resulting in acquisition of a more aggressive phenotype via other growth factor receptors like NTR1.

Gene expression in response to ionizing radiation and family history of gastric cancer

Genes and molecular pathways involved in familial clustering of gastric cancer have not yet been identified. The purpose of the present study was to investigate gene expression changes in response to a cellular stress, and its link with a positive family history for this neoplasia. To this aim leukocytes of healthy first-degree relatives of gastric cancer patients and controls were challenged in vitro with ionizing radiation and gene expression evaluated 4 h later on microarrays with 1,800 cancer-related genes. Eight genes, mainly involved in signal transduction and cell cycle regulation, were differentially expressed in healthy relatives of gastric cancer cases. Functional class scoring by Gene Ontology classification highlighted two G-protein related pathways, implicated in the proliferation of neoplastic tissue, which were differentially expressed in healthy subjects with positive family history of gastric cancer. The relative expression of 84 genes related to these pathways was examined using the SYBR green-based quantitative real-time PCR. The results confirmed the indication of an involvement of G-protein coupled receptor pathways in GC familiarity provided by microarray analysis. This study indicates a possible association between familiarity for gastric cancer and altered transcriptional response to ionizing radiation.

Characterization of promoter elements regulating the expression of the human neurotensin/neuromedin N gene

Expression of the gene encoding neurotensin/neuromedin N (NT/N) is mostly limited to the brain and specialized enteroendocrine N cells in the distal small intestine. We have identified key regulatory elements in the promoter region that are involved in human NT/N (hNT/N) gene expression in the novel human endocrine cell line, BON, which resembles intestinal N cells in several important aspects including NT/N precursor protein processing, ratios of different NT/N mRNA isoforms, and high levels of constitutive expression of the NT/N gene. In this study, we demonstrated multiple cis-regulatory elements including a proximal region containing a cAMP-responsive element (CRE)/AP-1-like element that binds both the AP-1 and CRE-binding protein (CREB)/ATF proteins (c-Jun, ATF-1, ATF-2, JunD, and CREB). Similar to the rat NT/N gene, this region is critical for constitutive hNT/N gene expression. Moreover, we identified a novel region that binds the orphan hormone receptor, NR2F2. We have demonstrated that the C terminus of NR2F2 strongly represses hNT/N transcription, whereas an N-terminal domain antagonizes this repressive effect. Regulation of NT/N expression by NR2F2 may have important consequences for lipid metabolism. We speculate that a complex interplay between the proximal CRE/AP-1-like motif and NR2F2 binding region exists to regulate hNT/N expression, which is critical for the high level of constitutive expression of NT/N in enteroendocrine cells. Finally, the BON cell line provides a unique model to characterize the factors regulating expression of the hNT/N gene and to better understand the mechanisms responsible for terminal differentiation of the N cell lineage in the gut.

Melatonin induces calcium release from CCK-8- and thapsigargin-sensitive cytosolic stores in pancreatic AR42J cells

Melatonin is produced following circadian rhythm with high levels being released at night and has been implicated in the regulation of physiological processes in major tissues, including the pancreas. The aim of our study was to examine the effects of melatonin on intracellular free Ca(2+) concentration ([Ca(2+) ](c)) in AR42J pancreatic cells. Our results show that stimulation of cells with 1 nm cholecystokinin (CCK)-8 led to a transient increase in [Ca(2+) ](c) followed by a decrease towards a value close to the prestimulation level. Melatonin (at the concentrations 1, 10, 100 μm and 1 mm) induced changes in [Ca(2+) ](c) that consisted of single or short lasting spikes in the form of oscillations or slow transient increases followed by a slow reduction towards a value close to the resting level. Depletion of intracellular Ca(2+) stores by stimulation of cells with 1 nm CCK-8 or 1 μm thapsigargin (Tps) blocked Ca(2+) responses evoked by melatonin in the majority of cells. Conversely, prior stimulation of cells with 1 mm melatonin in the absence of extracellular Ca(2+) inhibited Ca(2+) mobilization in response to a secondary application of CCK-8 or Tps. In summary, our results show that melatonin releases Ca(2+) from intracellular stores and can therefore modulate the responses of the pancreas to CCK-8. The source for Ca(2+) mobilization most probably is the endoplasmic reticulum. These data raise the possibility that melatonin also involves Ca(2+) signalling, in addition to other intracellular messengers, to modulate cellular function.

Suppression of neurotensin receptor type 1 expression and function by histone deacetylase inhibitors in human colorectal cancers

Neurotensin, a gut peptide, stimulates the growth of colorectal cancers that possess the high-affinity neurotensin receptor (NTR1). Sodium butyrate (NaBT) is a potent histone deacetylase inhibitor (HDACi) that induces growth arrest, differentiation, and apoptosis of colorectal cancers. Previously, we had shown that NaBT increases nuclear GSK-3beta expression and kinase activity; GSK-3beta functions as a negative regulator of extracellular signal-regulated kinase (ERK) signaling. The purpose of our current study was to determine: (a) whether HDACi alters NTR1 expression and function, and (b) the role of GSK-3beta/ERK in NTR1 regulation. Human colorectal cancers with NTR1 were treated with various HDACi, and NTR1 expression and function were assessed. Treatment with HDACi dramatically decreased endogenous NTR1 mRNA, protein, and promoter activity. Overexpression of GSK-3beta decreased NTR1 promoter activity (> 30%); inhibition of GSK-3beta increased NTR1 expression in colorectal cancer cells, indicating that GSK-3beta is a negative regulator of ERK and NTR1. Consistent with our previous findings, HDACi significantly decreased phosphorylated ERK while increasing GSK-3beta. Selective MAP/ERK kinase/ERK inhibitors suppressed NTR1 mRNA expression in a time- and dose-dependent fashion, and reduced NTR1 promoter activity by approximately 70%. Finally, pretreatment with NaBT prevented neurotensin-mediated cyclooxygenase-2 and c-myc expression and attenuated neurotensin-induced interleukin-8 expression. HDACi suppresses endogenous NTR1 expression and function in colorectal cancer cell lines; this effect is mediated, at least in part, through the GSK-3beta/ERK pathway. The downregulation of NTR1 in colorectal cancers may represent an important mechanism for the anticancer effects of HDACi.

Increased mortality in prostate carcinoma and smoking-related disease after parietal cell vagotomy: a long-term follow-up study

OBJECTIVE

There is an increased risk of gastrointestinal carcinoma and smoking-related diseases after partial gastrectomy for peptic ulcer disease. The purpose of this study was to evaluate long-term cancer incidence and mortality after parietal cell vagotomy (PCV), a surgical method with a low rate of side effects, but creating hypochlorhydria in the stomach mimicking long-term treatment with antisecretory drugs.

MATERIAL AND METHODS

Data on 383 ulcer patients operated on with PCV during 1971-80 at Lund University Hospital were compared with the national registers for cause of death and cancer incidence for selected diagnoses. Median follow-up was 28 years and 31 years, respectively. Standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs) were calculated.

RESULTS

An increased incidence of cancer in the respiratory organs (SIR 1.97, 95% CI: 1.08-3.31) and prostate carcinoma (SIR 1.85, 95% CI: 1.22-2.69) was found, and among men also an increased mortality in prostate carcinoma (SMR 3.85, 95% CI: 1.41-8.38) and chronic respiratory disease (SMR 2.76, 95% CI: 1.01-6.02). Overall mortality was similar to that of the background population and no increased risk of gastrointestinal malignancies was observed.

CONCLUSIONS

Patients with peptic ulcer operated on with PCV have a long-term increased risk of smoking-related diseases, but PCV does not seem to increase the risk of gastrointestinal carcinoma. An increased risk of, and mortality in prostate carcinoma was found, a cancer previously not found to be related to smoking. This might be the result of surgery-induced hypochlorhydria, which warrants further investigation in patients on long-term proton-pump inhibitors.