High disease relapse after bDMARD spacing in psoriatic arthritis compared to rheumatoid arthritis and axial spondyloarthritis patients: real-life data from BIOPURE registry.

The objective is to evaluate the effectiveness of a spacing strategy of bDMARDs in a cohort of selected patients in disease remission or low-disease activity (LDA) without glucocorticoids affected with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA). This was a single-centre study carried out on patients prospectively enrolled in the biologic Apulian registry. Patients whose disease was in remission or LDA without taking glucocorticoids during the previous 6 months and who had agreed to increase the time interval between bDMARD doses were included in this study. Demographic and clinical characteristics were recorded at baseline and at 3, 6 and 12 months of follow-up. Endpoint of the study was the survival of spacing doses in the time lag of the study. Failure of spacing was defined as the first flare of disease. Thirty-seven RA, 28 PsA and 20 axSpA patients underwent bDMARD spacing according to a local strategy. During the follow-up, 5 RA, 6 PsA and 4 axSpA patients had a joint flare, but further 5 PsA patients manifested a skin relapse. Global persistence was 86.5% for RA (MST = 41 (95% CI: 37-45) months) and 80% for axSpA patients (MST = 36 (95% CI: 31-42) months). PsA patients showed a lower persistence, being of 60.7% (MST = 30 (95% CI: 23-36) months) (log-rank test, p = 0.03). Dose reduction by spacing bDMARD doses may be a feasible approach in patients with persistent remission/LDA activity. However, PsA patients might have greater odds of spacing failure because of skin psoriasis relapse. Key Points • Spacing of bDMARDs may be a feasible strategy for some patients with rheumatoid arthritis, psoriatic arthritis and axial spondyloarthritis who achieve the target and withdrawn glucocorticoids. • Psoriatic arthritis patients showed lower persistence because of both articular and skin relapses.

γ-Tocopherol inhibits human prostate cancer cell proliferation by up-regulation of transglutaminase 2 and down-regulation of cyclins.

To establish a system to study differentiation therapy drugs, we used the androgen-independent human prostate PC-3 tumor cell line as a target and α- and γ-tocopherol as inducers. Effects of α- and γ-tocopherol on the cell cycle, proliferation and differentiation, were examined. A more significant growth inhibition activity for γ- than for α-tocopherol was observed. Flow cytometry analysis of α- and γ-tocopherol-treated prostate carcinoma PC3 cells showed decreased progression into the S-phase. This effect, particularly evident for γ-tocopherol, was associated with an up-regulation and increased activity of transglutaminase 2 (TG2), a reduced DNA synthesis and a remarkable decreased levels of cyclin D1 and cyclin E. Activation of TG2 suggests that γ-tocopherol has an evident differentiative capacity on PC3 cells, leading to an increased expression of TG2, and reduced cyclin D1 and cyclin E levels, affecting cell cycle progression. It is feasible that up-regulation and activation of TG2, associated with a reduced proliferation, are parts of a large-scale reprogramming that can attenuate the malignant phenotype of PC3 cells in vitro. These data suggest further investigation on the potential use of this γ-form of vitamin E as a differentiative agent, in combination with the common cytotoxic treatments for prostate cancer therapy.

eIF5A isoforms and cancer: two brothers for two functions?

Eukaryotic translation initiation factor 5A (eIF5A) is the only cellular protein that contains the unusual amino acid hypusine [N(ε)-(4-amino-2-hydroxybutyl)lysine]. The role of hypusine formation in the eIF5A protein in the regulation of cell proliferation and apoptosis is addressed in the present review. Moreover, vertebrates carry two genes that encode two eIF5A isoforms, eIF5A-1 and eIF5A-2, which, in humans, are 84% identical. However, the biological functions of these two isoforms may be significantly different. In fact, eIF5A-1 is demonstrable in most cells of different histogenesis, whereas eIF5A-2 protein is detectable only in certain human cancer cells or tissues, suggesting its role as a potential oncogene. In this review we focus our attention on the involvement of eIF5A-1 in the triggering of an apoptotic program and in the regulation of cell proliferation. In addition, the potential oncogenic role and prognostic significance of eIF5A-2 in the prediction of the survival of cancer patients is described. eIF5A-1 and/or the eIF5A-2 isoform may serve as a new molecular diagnostic or prognostic marker or as a molecular target for anti-cancer therapy.

Raf kinases mediate the phosphorylation of eukaryotic translation elongation factor 1A and regulate its stability in eukaryotic cells.

We identified eukaryotic translation elongation factor 1A (eEF1A) Raf-mediated phosphorylation sites and defined their role in the regulation of eEF1A half-life and of apoptosis of human cancer cells. Mass spectrometry identified in vitro S21 and T88 as phosphorylation sites mediated by B-Raf but not C-Raf on eEF1A1 whereas S21 was phosphorylated on eEF1A2 by both B- and C-Raf. Interestingly, S21 belongs to the first eEF1A GTP/GDP-binding consensus sequence. Phosphorylation of S21 was strongly enhanced when both eEF1A isoforms were preincubated prior the assay with C-Raf, suggesting that the eEF1A isoforms can heterodimerize thus increasing the accessibility of S21 to the phosphate. Overexpression of eEF1A1 in COS 7 cells confirmed the phosphorylation of T88 also in vivo. Compared with wt, in COS 7 cells overexpressed phosphodeficient (A) and phospho-mimicking (D) mutants of eEF1A1 (S21A/D and T88A/D) and of eEF1A2 (S21A/D), resulted less stable and more rapidly proteasome degraded. Transfection of S21 A/D eEF1A mutants in H1355 cells increased apoptosis in comparison with the wt isoforms. It indicates that the blockage of S21 interferes with or even supports C-Raf induced apoptosis rather than cell survival. Raf-mediated regulation of this site could be a crucial mechanism involved in the functional switching of eEF1A between its role in protein biosynthesis and its participation in other cellular processes.

BRAF and PIK3CA genes are somatically mutated in hepatocellular carcinoma among patients from South Italy.

Poor data have been previously reported about the mutation rates in K-RAS, BRAF, and PIK3CA genes among patients with hepatocellular carcinoma (HCC). Here we further elucidated the role of these genes in pathogenesis of primary hepatic malignancies. Archival tumour tissue from 65 HCC patients originating from South Italy were screened for mutations in these candidate genes by direct sequencing. Overall, oncogenic mutations were detected in 15 (23%) patients for BRAF gene, 18 (28%) for PIK3CA gene, and 1 (2%) for K-RAS gene. Using statistical analysis, BRAF mutations were significantly correlated with the presence of either multiple HCC nodules (P=0.021) or higher proliferation rates (P=0.034). Although further extensive screenings are awaited in HCC patients among different populations, our findings clearly indicated that mutational activation of both BRAF and PIK3CA genes does contribute to hepatocellular tumorigenesis at somatic level in Southern Italian population.

Nanotech revolution for the anti-cancer drug delivery through blood-brain barrier.

Nanotechnology-based drug delivery was born as a chance for pharmaceutical weapons to be delivered in the body sites where drug action is required. Specifically, the incorporation of anti-cancer agents in nanodevices of 100-300 nm allows their delivery in tissues that have a fenestrated vasculature and a reduced lymphatic drainage. These two features are typical of neoplastic tissues and, therefore, allow the accumulation of nanostructured devices in tumours. An important issue of anti-cancer pharmacological strategies is the overcoming of anatomical barriers such as the bloodbrain- barrier (BBB) that protects brain from toxicological injuries but, at the same time, makes impossible for most of the pharmacological agents with anti-cancer activity to reach tumour cells placed in the brain and derived from either primary tumours or metastases. In fact, only highly lipophilic molecules can passively diffuse through BBB to reach central nervous system (CNS). Another possibility is to use nanotechnological approaches as powerful tools to across BBB, by both prolonging the plasma half-life of the drugs and crossing fenestrations of BBB damaged by brain metastases. Moreover, modifications of nanocarrier surface with specific endogenous or exogenous ligands can promote the crossing of intact BBB as in the case of primary brain tumours. This aim can be achieved through the binding of the nanodevices to carriers or receptors expressed by the endothelial cells of BBB and that can favour the internalization of the nanostructured devices delivering anti-cancer drugs. This review summarizes the most meaningful advances in the field of nanotechnologies for brain delivery of drugs.

Cetuximab ± chemotherapy enhances dendritic cell-mediated phagocytosis of colon cancer cells and ignites a highly efficient colon cancer antigen-specific cytotoxic T-cell response in vitro.

Cetuximab is a human/mouse chimeric IgG1 monoclonal antibody (mAb) to epidermal growth factor receptor, approved for colorectal carcinoma treatment in combination with chemotherapy. The immune-mediated effects elicited by its human fraction of crystallization moiety might critically contribute to the overall anti-tumor effectiveness of the antibody. We therefore investigated cetuximab ability to promote colon cancer cell opsonization and phagocytosis by human dendritic cells (DCs) that are subsequently engaged in antigen-cross presentation to cytotoxic T-lymphocyte (CTL) precursors. Human colon cancer cell lines were evaluated for susceptibility to DC-mediated phagocytosis before and after treatment with chemotherapy ± cetuximab in vitro. Human DCs loaded with control or drug-treated cetuximab-coated colon cancer cells were used to in vitro generate cytotoxic T cell clones from peripheral blood mononuclear cells of human leucocyte antigen-A(*)02.01(+) donors. T-cell cultures were characterized for immune-phenotype and tumor-antigen specific CTL activity. The results confirmed that treatment of tumor cells with irinotecan + L-folinate + 5-flurouracil (ILF) or with gemcitabine + ILF increased tumor antigen expression. Moreover, malignant cells exposed to chemotherapy and cetuximab were highly susceptible to phagocytosis by human DCs and were able to promote their activation. The consequent DC-mediated cross-priming of antigens derived from mAb-covered/drug-treated cancer cells elicited a robust CTL anti-tumor response. On the basis of our data, we suggest a possible involvement of CTL-dependent immunity in cetuximab anti-cancer effects.

Everolimus is an active agent in medullary thyroid cancer: a clinical and in vitro study.

Everolimus, an mTOR inhibitor, which has been demonstrated to induce anti-tumour effects in different types of neuroendocrine tumours, has never been evaluated in patients with medullary thyroid cancer (MTC). The aim of this study was to evaluate the in vitro and in vivo effects of everolimus in combination with octreotide in MTC. Two patients with progressive metastatic MTC and high calcitonin levels were treated with everolimus 5-10 mg/day. Both patients were under treatment with octreotide LAR at the study entry. An in vitro study was also performed to assess everolimus effects on MTC cell lines (TT and MZ-CRC-1 cells). A tumour response was observed in both patients. Serum calcitonin decreased by 86% in patient 1 and by 42% in patient 2. In TT and MZ-CRC-1 cells, everolimus induced a significant dose-dependent inhibition in cell proliferation. This effect seems to be related to a cell cycle arrest in G(0) /G(1) phase in both cell lines and to the induction of cellular senescence in TT cells. Everolimus in combination with octreotide may be active as anti-tumour therapy in patients with progressive metastatic MTC, suggesting to further evaluate this agent in MTC patients in a large prospective study.

Oxidative stress and ERK1/2 phosphorylation as predictors of outcome in hepatocellular carcinoma patients treated with sorafenib plus octreotide LAR.

We reported a relevant activity of the combination between sorafenib and octreotide long-acting release (LAR) in advanced hepatocellular carcinoma (HCC) patients. In this work, we have studied if oxidative stress in both serum and peripheral blood mononuclear cells (PBMC) and pERK activation status in PBMC could be predictive of response. In the 20 responsive patients, the decrease of reactive oxygen species levels was already detectable after 10 days (T10) from the beginning of sorafenib administration, and this effect was enhanced by the combined treatment with sorafenib+octreotide LAR (T21). This effect correlated with the modulation of superoxide dismutase (SOD) activity (physiological scavenger of O(2-)) and of serum nitric oxide (NO) levels. Sorafenib alone induced an increase of about 40% of NO levels and of about two-fold of SOD activity in responsive patients, and both effects were significantly potentiated by the combined treatment. We found a gradual reduction of Erk1/2 activity, as evaluated by cytofluorimetric analysis, in 15 responsive patients reaching about 50% maximal decrease at T21. On the other hand, in 17 resistant patients, Erk1/2 activity was about 80% increased at T21. The determination of both the oxidative stress status and pERK activity in PBMC has high value in the prediction of response to sorafenib+octreotide therapy in HCC patients.

Gemcitabine/cannabinoid combination triggers autophagy in pancreatic cancer cells through a ROS-mediated mechanism.

Gemcitabine (GEM, 2',2'-difluorodeoxycytidine) is currently used in advanced pancreatic adenocarcinoma, with a response rate of < 20%. The purpose of our work was to improve GEM activity by addition of cannabinoids. Here, we show that GEM induces both cannabinoid receptor-1 (CB1) and cannabinoid receptor-2 (CB2) receptors by an NF-κB-dependent mechanism and that its association with cannabinoids synergistically inhibits pancreatic adenocarcinoma cell growth and increases reactive oxygen species (ROS) induced by single treatments. The antiproliferative synergism is prevented by the radical scavenger N-acetyl-L-cysteine and by the specific NF-κB inhibitor BAY 11-7085, demonstrating that the induction of ROS by GEM/cannabinoids and of NF-κB by GEM is required for this effect. In addition, we report that neither apoptotic nor cytostatic mechanisms are responsible for the synergistic cell growth inhibition, which is strictly associated with the enhancement of endoplasmic reticulum stress and autophagic cell death. Noteworthy, the antiproliferative synergism is stronger in GEM-resistant pancreatic cancer cell lines compared with GEM-sensitive pancreatic cancer cell lines. The combined treatment strongly inhibits growth of human pancreatic tumor cells xenografted in nude mice without apparent toxic effects. These findings support a key role of the ROS-dependent activation of an autophagic program in the synergistic growth inhibition induced by GEM/cannabinoid combination in human pancreatic cancer cells.

Self-assembly nanoparticles for the delivery of bisphosphonates into tumors.

Bisphosphonates (BPs) are molecules able to induce apoptosis in several cancer cell lines. However, their short half-life and the rapid uptake and accumulation within bone, limit its use as antitumor agent for extra-skeletal malignancies. Here we proposed a new delivery system to avoid BP accumulation into the bone, thus improving extra-skeletal bioavailability. In this work, we used the zoledronic acid (ZOL), a third generation bisphosphonate, able to induce apoptosis at micromolar concentration. We developed ZOL-containing self-assembly PEGylated nanoparticles (NPs) based on ZOL complexes with calcium phosphate NPs (CaPZ NPs) and cationic liposomes. PEGylation was achieved by two different strategies. CaPZ NPs were covered with PEGylated liposomes (pre-PLCaPZ NPs); alternatively, CaPZ NPs were previously mixed with cationic liposomes and then PEGylated by post-insertion method (post-PLCaPZ NPs). The NPs were fully characterized in terms of mean diameter and size distribution, morphology, ZOL loading, antiproliferative effect on different cell lines. Pre-PLCaPZ NPs showed the best technological characteristics, with a narrow size distribution and a high ZOL loading. Moreover, on different cancer cell lines, these NPs enhanced the antiproliferative effect of ZOL. Finally, in an animal model of prostate cancer, a significant reduction of tumor growth was achieved with pre-PLCaPZ NPs, while the tumor was unaffected by ZOL in solution.

WNT pathway in oral cancer: epigenetic inactivation of WNT-inhibitors.

Epigenetic DNA methylations plays an important role in oral carcinogenesis. The soluble frizzled receptor protein (SFRP) family together with WIF-1 and DKK-3 encodes antagonists of the WNT pathway. Silencing of these genes leads to constitutive WNT signalling. Because aberrant expression of beta-catenin might be associated with the epigenetic inactivation of WNT inhibitors, we analyzed, in a collection of primary OSCC with matched normal oral mucosa, the methylation status of a complete panel of genes, SFRP-1, SFRP-2, SFRP-4, SFRP-5, WIF-1, DKK-3, that are involved directly and indirectly in WNT pathway, in order to demonstrate WNT-pathway activation in the absence of beta-catenin and/or APC/Axin mutations during oral carcinogenesis. Methylation-specific PCR (MSP) was performed to study inactivation of SFRP-1, SFRP-2, SFRP-4, SFRP-5, WIF-1, DKK-3 genes in 37 cases of paraffin embedded oral cancer. This study showed that the methylation is an important epigenetic alteration in oral cancer. In particular, SFRP-2, SFRP-4, SFRP-5, WIF-1, DKK-3 revealed methylation status of their promoter in OSCC, whereas SFRP-1 showed demethylation in cancer. Fisher's exact test revealed statistically significant results (p<0.05) for all genes. The Wald test confirmed the statistically significant association between SFRP2-4-5 gene methylation and OSCC (p<0.05). SFRP-1 was also characterized by a different statistically significant epigenetic behaviour, because of it was demethylated in cancer (p<0.05). Statistical regression test showed high levels of sensitivity, specificity and accuracy for SFRP genes, while WIF-1 and DKK-3 have reportedly high specificity, moderate accuracy but low sensitivity. This study suggests that a cause of catenin delocalization in oral cancer could be due to WNT pathway activation, by epigenetic alterations of SFRP, WIF-1 and DKK-3 genes.

Cutting the limits of aminobisphosphonates: new strategies for the potentiation of their anti-tumour effects.

Therapy with aminobisphosphonate (N-BPs), and zoledronic acid (ZOL) especially, has become a standard of care for patients with malignant bone disease. In addition, preclinical and preliminary clinical data suggest that N-BPs exert their direct or indirect anti-tumour effects on cancer growth factor release, cancer cell adhesion, invasion and viability, cancer angiogenesis and cancer cell apoptosis. Here, we will discuss the molecular mechanisms of the antitumour effects induced by ZOL. Despite their well-established in vitro anti-tumour effects N-BPs have not clear in vivo anti-tumour activity in humans. The bases of these discrepancies will be discussed in the text with a special focus on the pharmacokinetic limits of N-BPs. Moreover, the following molecular and pharmacological strategies in order to overcome N-BPs limitations will be described: i) development of pharmacological combinations with other biological agents; ii) finding of new molecular targets of N-BPs; iii) development of new pharmacological formulations of N-BPs. Finally, a new scenario of integrated bio-medicine and pharmacology will be depicted in order to drive the optimization of anti-cancer activity of N-BPs.

Denosumab: the era of targeted therapies in bone metastatic diseases.

This system constituted of the Receptor Activator of nuclear Factor-kB Ligand (RANKL), the Receptor Activator of Nuclear Factor-kB (RANK) and by the decoy Receptor Osteoprotegerin (OPG) plays a central role in bone resorption. Denosumab (AMG 162) is an investigational fully human monoclonal antibody with a high affinity and specificity for RANKL.This review will critically describe and discuss the recent results of clinical trial investigating denosumab in different settings of medical oncology. In particular, we will report the recently published data of clinical trials investigating denosumab in prevention of cancer treatment induced bone loss (CTIBL), in prevention of skeletal related events (SREs) in bone metastatic patients and the ongoing studies in prevention of disease recurrence in the adjuvant setting of solid tumours. The clinical data that will be reported in this review represent the first step in a path that will conduct us to explore new horizons in the field of bone health care in cancer patients.

Challenging the current approaches to multiple myeloma-related bone disease: from bisphosphonates to target therapy.

Bone disease (BD) is the hall-mark clinical feature of multiple myeloma (MM), accounting up to 60% of patients with bone pain at diagnosis and 60% with a pathologic fracture during the course of their disease. Experimental models, which recapitulate in vivo the human bone marrow microenvironment (HBMM) in immunodeficient mice have been recently developed as valuable tool for the study of MM pathophysiology as well as the experimental treatment of BD. At present, bisphosphonates are the mainstay treatment of MM-related BD. The growing information on the cellular and molecular bases of BD as well as the availability of novel anti-resorptive agents, such as the IgG1-anti-RANKL (AMG 161) Denosumab, are now depicting a new scenario where the treatment will be afforded by the use of different agents. Furthermore the availability of highthroughput molecular profiling approaches, including DNA microarrays and proteomics, is likely to provide new platforms for patients stratification and treatment individualization on specific targets. It is now the right time for a therapeutical approach which is rationally based on the complexity of the biopathology of MM-related BD.

Emerging strategies to strengthen the anti-tumour activity of type I interferons: overcoming survival pathways.

Interferon-a (IFN-a) is currently the most used cytokine in the treatment of cancer. However, the potential anti-tumour activity of IFN-a is limited by the activation of tumour resistance mechanisms. In this regard, we have shown that IFN-a, at growth inhibitory concentrations, enhances the EGF-dependent Ras-->Erk signalling and decreases the adenylate cyclase/cAMP pathway activity in cancer cells; both effects represent escape mechanisms to the growth inhibition and apoptosis induced by IFN-a. The selective targeting of these survival pathways might enhance the antitumor activity of IFN-ain cancer cells, as shown by: i) the combination of selective EGF receptor tyrosine kinase inhibitor (gefitinib) and IFN-a having cooperative anti-tumour effects; ii) the farnesyl-transferase inhibitor R115777 strongly potentiating the anti-tumour activity of IFN-a both in vitro and in vivo through the inhibition of different escape mechanisms that are dependent on isoprenylation of intracellular proteins such as ras; iii) the cAMP reconstituting agent (8-Br-cAMP) enhancing the pro-apoptotic activity of IFN-alpha. IFN-beta is a multifunctional cytokine binding the same receptor of IFN-alpha, but with higher affinity (10-fold) and differential structural interactions. We recently showed that IFN-beta is considerably more potent than IFN-alpha in its anti-tumour effect through the induction of apoptosis and/or cell cycle arrest in S-phase. The emergence of long-acting pegylated forms of IFN-beta makes this agent a promising anti-cancer drug. These observations open a new scenario of anticancer intervention able to strengthen the antitumor activity of IFN-alpha or to use more potent type I IFNs.

Possible antioxidant role of SPA therapy with chlorine-sulphur-bicarbonate mineral water.

The aim of our research was to analyze the antioxidant role and efficacy of thermal or salus per aquam (spa) therapy with chlorine-sulphur-bicarbonate mineral water. The study has been performed on 30 rats. The animals were randomized in three groups, each of them composed by ten animals, denominated A, B and C. The A group was the control group and was not subjected to any specific treatment (placebo); the B group has been treated with a standard cycle of hydropinics treatment with mineral water of Therme of Stabia in Castellammare (Naples, Italy) denominated STABIA; the C group was treated with a standard cycle of hydropinic treatment with mineral water of Therme of Stabia in Castellammare (Naples, Italy) denominated SULFUREA. After two weeks of treatment all the rats were sacrificed and blood was collected for the plasmatic determination of reactive oxygen species (ROS). The results demonstrated a significant (P < 0.05) reduction of ROS in B (374 Carr. U. +/-73) and C group (399 carr. U. +/-62) treated with mineral waters if compared with control group (571 + 69 Carr. U.). In conclusion this study suggests a possible antioxidant effect of chlorine-sulphur-bicarbonate spa hydropinic treatment with a consequent suitable intestinal physiology, with reduction of the functional and organic modifications that can lead to pathological disorders of the gastroenteric diseases in whose pathogenesis the oxidative stress can develop an important role.

Bovine serum amine oxidase and spm potentiate docetaxel and interferon-alpha effects in inducing apoptosis on human cancer cells through the generation of oxidative stress.

It was previously demonstrated that bovine serum amine-oxidase (BSAO) and SPM (SPM) addition to cancer cells induces cell growth inhibition and over-run the multi-drug resistance (MDR) phenotype through the oxidative stress caused by polyamine metabolites. In this study, it is reported that BSAO/SPM enzymatic system antagonizes the survival pathway induced by either docetaxel (DTX) or interferon alpha (IFNalpha) in human epidermoid cancer KB cells. The combination of BSAO/SPM with either DTX or IFNalpha had a synergistic effect on cell growth inhibition through apoptosis in both human epidermoid KB and breast cancer MCF-7 cell lines. The effects of the BSAO/SPM-DTX combination on apoptosis were caspase 3 and 9-dependent and were paralleled by the enhancement of intracellular O(2-), nitric oxide levels and of lipo-oxidation. The scavenger moiety N-acetyl-cysteine antagonized the effects on apoptosis and cell growth inhibition induced by the combination suggesting a role of the oxidative products of SPM. These effects occurred together with a decrease of the physiological scavenger MnSOD and an increase of both p38 kinase activity and DNA damage. The results suggest that DTX and IFNalpha could sensitize tumour cells to the oxidative stress and apoptosis induced by BSAO/SPM through the induction of a survival ras-dependent pathway and the consequent elevation of the intracellular polyamine pool. These data allow the design of new therapeutic strategy based on the use of this combination in human neoplasms.

Experimental study on vasoactive intestinal peptide (VIP) and its diaminopropane bound (VIP-DAP) analog in solution.

Bioactive peptides represent an exciting area of research in the fields of biochemistry and medicine and in particular the VIP/PACAP network appears to be of interest. Vasoactive intestinal peptide (VIP) is a pleiotropic factor that exerts a physiological regulatory influence and is involved in the pathogenesis of several human disorders. In this paper we have reported structural characterization of VIP by experimental and computational methods as well as a comparative analysis of the peptide with its transglutaminase catalyzed analog VIP-Diaminopropane (VIP-DAP).