Phase Ib dose-escalation study of the hypoxia-modifier Myo-inositol trispyrophosphate in patients with hepatopancreatobiliary tumors.

Hypoxia is prominent in solid tumors and a recognized driver of malignancy. Thus far, targeting tumor hypoxia has remained unsuccessful. Myo-inositol trispyrophosphate (ITPP) is a re-oxygenating compound without apparent toxicity. In preclinical models, ITPP potentiates the efficacy of subsequent chemotherapy through vascular normalization. Here, we report the results of an unrandomized, open-labeled, 3 + 3 dose-escalation phase Ib study (NCT02528526) including 28 patients with advanced primary hepatopancreatobiliary malignancies and liver metastases of colorectal cancer receiving nine 8h-infusions of ITPP over three weeks across eight dose levels (1'866-14'500 mg/m2/dose), followed by standard chemotherapy. Primary objectives are assessment of the safety and tolerability and establishment of the maximum tolerated dose, while secondary objectives include assessment of pharmacokinetics, antitumor activity via radiological evaluation and assessment of circulatory tumor-specific and angiogenic markers. The maximum tolerated dose is 12,390 mg/m2, and ITPP treatment results in 32 treatment-related toxicities (mostly hypercalcemia) that require little or no intervention. 52% of patients have morphological disease stabilization under ITPP monotherapy. Following subsequent chemotherapy, 10% show partial responses while 60% have stable disease. Decreases in angiogenic markers are noted in ∼60% of patients after ITPP and tend to correlate with responses and survival after chemotherapy.

Tumour angiogenesis normalized by myo-inositol trispyrophosphate alleviates hypoxia in the microenvironment and promotes antitumor immune response.

Pathologic angiogenesis directly responds to tumour hypoxia and controls the molecular/cellular composition of the tumour microenvironment, increasing both immune tolerance and stromal cooperation with tumour growth. Myo-inositol-trispyrophosphate (ITPP) provides a means to achieve stable normalization of angiogenesis. ITPP increases intratumour oxygen tension (pO2 ) and stabilizes vessel normalization through activation of endothelial Phosphatase-and-Tensin-homologue (PTEN). Here, we show that the tumour reduction due to the ITPP-induced modification of the tumour microenvironment by elevating pO2 affects the phenotype and properties of the immune infiltrate. Our main observations are as follows: a relative change in the M1 and M2 macrophage-type proportions, increased proportions of NK and CD8+ T cells, and a reduction in Tregs and Th2 cells. We also found, in vivo and in vitro, that the impaired access of PD1+ NK cells to tumour cells is due to their adhesion to PD-L1+ /PD-L2+ endothelial cells in hypoxia. ITPP treatment strongly reduced PD-L1/PD-L2 expression on CD45+/CD31+ cells, and PD1+ cells were more numerous in the tumour mass. CTLA-4+ cell numbers were stable, but level of expression decreased. Similarly, CD47+ cells and expression were reduced. Consequently, angiogenesis normalization induced by ITPP is the mean to revert immunosuppression into an antitumor immune response. This brings a key adjuvant effect to improve the efficacy of chemo/radio/immunotherapeutic strategies for cancer treatment.

An update on vascular calcification and potential therapeutics.

Pathological calcification is a major cause of cardiovascular morbidities primarily in population with chronic kidney disease (CKD), end stage renal diseases (ERSD) and metabolic disorders. Investigators have accepted the fact that vascular calcification is not a passive process but a highly complex, cell mediated, active process in patients with cardiovascular disease (CVD) resulting from, metabolic insults of bone fragility, diabetes, hypertension, dyslipidemia and atherosclerosis. Over the years, studies have revealed various mechanisms of vascular calcification like induction of bone formation, apoptosis, alteration in Ca-P balance and loss of inhibition. Novel clinical studies targeting cellular mechanisms of calcification provide promising and potential avenues for drug development. The interventions include phosphate binders, sodium thiosulphate, vitamin K, calcimimetics, vitamin D, bisphosphonates, Myoinositol hexaphosphate (IP6), Denosumab and TNAP inhibitors. Concurrently investigators are also working towards reversing or curing pathological calcification. This review focuses on the relationship of vascular calcification to clinical diseases, regulators and factors causing calcification including genetics which have been identified. At present, there is lack of any significant preventive measures for calcifications and hence this review explores further possibilities for drug development and treatment modalities.

Altered Ovarian Inositol Ratios May Account for Pathological Steroidogenesis in PCOS.

The presence of abnormal ovarian ratios of myo-inositol (MI) to D-chiro-inositol (DCI) is a recurrent feature in PCOS. Available evidence suggests that MI and DCI may modulate steroid biosynthesis, likely in an opposite manner. Specifically, MI seems to induce estrogen production, while DCI has a role in the synthesis of androgens. Elevated insulin levels, generally associated with PCOS, alter the physiological MI/DCI ratio, increasing MI-to-DCI conversion through activation of a specific epimerase enzyme. DCI directly increases testosterone biosynthesis in thecal cells and reduces its conversion to estradiol by downregulating aromatase enzyme in granulosa cells. This manuscript reviews the literature that supports the connection between altered MI/DCI ratios and pathological steroidogenesis observed in PCOS women. Furthermore, it discusses the application of inositol-based treatment protocols in managing PCOS symptoms and improving the quality of patients' life.

The Allosteric Hemoglobin Effector ITPP Inhibits Metastatic Colon Cancer in Mice.

OBJECTIVE: To test the effects of enhanced intracellular oxygen contents on the metastatic potential of colon cancer. BACKGROUND: Colorectal cancer is the commonest gastrointestinal carcinoma. Distant metastases occur in half of patients and are responsible for most cancer-related deaths. Tumor hypoxia is central to the pathogenesis of metastases. Myo-Inositoltrispyrophosphate (ITPP), a nontoxic, antihypoxic compound, has recently shown significant benefits in experimental cancer, particularly when combined with standard chemotherapy. Whether ITPP protects from distant metastases in primary colon cancer is unknown. METHODS: ITPP alone or combined with FOLFOX was tested in a mouse model with cecal implantation of green fluorescent protein-labeled syngeneic colorectal cancer cells. Tumor development was monitored through longitudinal magnetic resonance imaging-based morphometric analysis and survival. Established serum markers of tumor spread were measured serially and circulating tumor cells were detected via fluorescence measurements. RESULTS: ITPP significantly reduced the occurrence of metastases as well as other indicators of tumor aggressiveness. Less circulating tumor cells along with reduction in malignant serum markers (osteopontin, Cxcl12) were noted. The ITPP benefits also affected the primary cancer site. Importantly, animals treated with ITPP had a significant survival benefit compared with respective controls, while a combination of FOLFOX with ITPP conferred the maximum benefits, including dramatic improvements in survival (mean 86 vs 188 d). CONCLUSIONS: Restoring oxygen in metastatic colon cancer through ITPP inhibits tumor spread and markedly improves animal survival; an effect that is enhanced through the application of subsequent chemotherapy. These promising novel findings call for a clinical trial on ITPP in patients with colorectal cancer, which is under way.

The natural phosphoinositide derivative glycerophosphoinositol inhibits the lipopolysaccharide-induced inflammatory and thrombotic responses.

Inflammatory responses are elicited through lipid products of phospholipase A2 activity that acts on the membrane phospholipids, including the phosphoinositides, to form the proinflammatory arachidonic acid and, in parallel, the glycerophosphoinositols. Here, we investigate the role of the glycerophosphoinositol in the inflammatory response. We show that it is part of a negative feedback loop that limits proinflammatory and prothrombotic responses in human monocytes stimulated with lipopolysaccharide. This inhibition is exerted both on the signaling cascade initiated by the lipopolysaccharide with the glycerophosphoinositol-dependent decrease in IκB kinase α/ß, p38, JNK, and Erk1/2 kinase phosphorylation and at the nuclear level with decreased NF-κB translocation and binding to inflammatory gene promoters. In a model of endotoxemia in the mouse, treatment with glycerophosphoinositol reduced TNF-α synthesis, which supports the concept that glycerophosphoinositol inhibits the de novo synthesis of proinflammatory and prothrombotic compounds and might thus have a role as an endogenous mediator in the resolution of inflammation. As indicated, this effect of glycerophosphoinositol can also be exploited in the treatment of manifestations of severe inflammation by exogenous administration of the compound.

ITPP Treatment of RG2 Glioblastoma in a Rat Model.

BACKGROUND: Inositol trispyrophosphate (ITPP) has been shown to reduce tumour growth in different animal cancer models, as well as of human U87 glioma cells grafted onto chick chorioallantoic membrane (CAM). The aim of this study was to establish whether ITPP crosses the blood-brain barrier and whether it halts the growth of RG2 glioblastoma tumour. MATERIALS AND METHODS: A model comprising of Fischer 344 rats was chosen and RG2 cells were implanted either intracranially, or subcutaneously on the left hind leg, and the animals were treated with ITPP either intraperitoneally, intravenously or both routes combined. Overall survival was then calculated. RESULTS: No prolonged survival was seen in animals treated with ITPP. The route of ITPP administration did not affect outcome. CONCLUSION: ITPP had no favourable effect upon survival in our animal model with RG2 glioblastoma tumours in Fischer 344 rats.

Development of OXY111A, a novel hypoxia-modifier as a potential antitumor agent in patients with hepato-pancreato-biliary neoplasms - Protocol of a first Ib/IIa clinical trial.

BACKGROUND: Solid tumors, such as hepato-pancreato-biliary cancer, develop tumor hypoxia with tumor growth. Despite advances in surgery, a majority of these patients are in an unresectable condition. At this stage standard cytotoxic chemotherapy regimens are applied with limited success. Novel biological treatment options based on an antiangiogenic mechanism of action neglect other hypoxia mediated mechanisms (e.g. epithelial-mesenchymal transition, Warburg effect, and immunological response) leading to an increased invasiveness with a poor outcome. The novel antihypoxic molecule myo-inositoltrispyrophosphate (ITPP, OXY111A) acts as an allosteric effector of hemoglobin and promotes normoxia in hypoxic tumors. In preclinical studies, tumor growth was reduced and survival prolonged. Additionally, a beneficial side effect profile was observed. METHODS: In this first Ib/IIa clinical trial we will assess safety and tolerability of OXY111A as well as a proof of concept regarding efficacy in patients with non-resectable primary and secondary tumors of the liver, pancreas, and biliary tract. The study design is exploratory, prospective, open-labelled and mono-centric. The study is divided in a dose escalation part with a maximum of 48 subjects and an extension part, in which 21 subjects will be included. DISCUSSION: The novel antihypoxic compound OXY111A has been tested in several cancer animal models showing beneficial effects for both survival and low side effect profiles. This first in patient application of OXY111A will reveal potential beneficial outcomes if anti-hypoxic therapy is added to standard cytotoxic treatment in patients with primary and secondary hepatopancreatobiliary tumors. TRIAL REGISTRATION: Institution Ethical Board Approval ID: KEK-ZH-Nr. 2014-0374; Swiss regulatory authority Swissmedic (2015DR1009); ClinicalTrials.gov Identifier: NCT02528526 , prospectively registered on November 11th, 2014.

Myo-inositol trispyrophosphate-mediated hypoxia reversion controls pancreatic cancer in rodents and enhances gemcitabine efficacy.

Hypoxia and dysfunctional tumor vessels represent a prominent feature of pancreatic cancer, being, at least in part, responsible for chemotherapy resistance and immune suppression in these tumors. We tested whether the increase of oxygen delivery induced in vivo by myo-inositol trispyrophosphate (ITPP) can reverse hypoxia, control tumor growth and improve chemotherapy response. Tumor size, metastatic development (microcomputed tomography scan follow-up) and the survival of rats and nude or NOD.SCID mice, (bearing syngenic rat and MiaPaCa2- or patient-derived pancreatic tumors), were determined on ITPP and/or gemcitabine treatment. Partial oxygen pressure, expression of angiogenic factors and tumor histology were evaluated. Infiltration and oxidative status of immune cells, as well as chemotherapy penetration in tumors, were determined by fluorescence-activated cell sorting, fluorometry, nitric oxide release assays, Western blot and confocal microscopy. Weekly intravenous ITPP application resulted in the inhibition of metastasis development and restricted primary tumor growth, showing a superior effect on the rats' survival compared with gemcitabine. ITPP treatment restored tumor normoxia and caused a reduction in hypoxia inducible factor-1α levels, with subsequent VEGF and Lox downregulation, resulting in improved vessel structure and decreased desmoplasia. The latter effects translated into elevated immune cells influx and improved susceptibility to gemcitabine treatment. Growth of human pancreatic tumor xenografts was strongly inhibited by administration of ITPP. ITPP exploits a two-stage mechanism causing rapid, early and sustainable late stage normoxia. This is due to the angiogenic factor modulation and vascular normalization, leading to enhanced chemotherapy delivery and synergistic life prolongation, on combination with low doses of gemcitabine.

Stable tumor vessel normalization with pO2 increase and endothelial PTEN activation by inositol trispyrophosphate brings novel tumor treatment.

Tumor hypoxia is a characteristic of cancer cell growth and invasion, promoting angiogenesis, which facilitates metastasis. Oxygen delivery remains impaired because tumor vessels are anarchic and leaky, contributing to tumor cell dissemination. Counteracting hypoxia by normalizing tumor vessels in order to improve drug and radio therapy efficacy and avoid cancer stem-like cell selection is a highly challenging issue. We show here that inositol trispyrophosphate (ITPP) treatment stably increases oxygen tension and blood flow in melanoma and breast cancer syngeneic models. It suppresses hypoxia-inducible factors (HIFs) and proangiogenic/glycolysis genes and proteins cascade. It selectively activates the tumor suppressor phosphatase and tensin homolog (PTEN) in vitro and in vivo at the endothelial cell (EC) level thus inhibiting PI3K and reducing tumor AKT phosphorylation. These mechanisms normalize tumor vessels by EC reorganization, maturation, pericytes attraction, and lowering progenitor cells recruitment in the tumor. It strongly reduces vascular leakage, tumor growth, drug resistance, and metastasis. ITPP treatment avoids cancer stem-like cell selection, multidrug resistance (MDR) activation and efficiently enhances chemotherapeutic drugs activity. These data show that counteracting tumor hypoxia by stably restoring healthy vasculature is achieved by ITPP treatment, which opens new therapeutic options overcoming hypoxia-related limitations of antiangiogenesis-restricted therapies. By achieving long-term vessels normalization, ITPP should provide the adjuvant treatment required in order to overcome the subtle definition of therapeutic windows for in vivo treatments aimed by the current strategies against angiogenesis-dependent tumors.

[Evaluation of the treatment with D-chiro-inositol on levels of oxidative stress in PCOS patients]. / Valuzione del trattamento con D-chiro-inositolo dui livelli di stress ossidativo nelle pazienti con PCOS.

AIM: Recent studies on the pathophysiology of infertility have shown that oxidative stress (OS) can be one of the causal factors. The OS is, by definition, an imbalance between the production of reactive oxygen species (ROS) and antioxidant defense systems. It seems that oxidative stress plays an important role in almost all phases of human reproduction. In fact, ROS are involved in the modulation of a large spectrum of reproductive functions such as oocyte maturation, ovarian steroidogenesis, corpus luteum functions and are involved in the processes of fertilization, embryo development and pregnancy, but also in some diseases that cause infertility. Polycystic ovary syndrome (PCOS) has recently been associated with increased oxidative stress, often put in relation to the syndrome's typical metabolic disorder. Inositol is an intracellular mediator of insulin, currently much used as a therapeutic agent in PCOS. While its main action takes place via insulin sensitization, little is known about the possible effects of other disorders, such as oxidative stress, associated with PCOS. The purpose of this study was therefore to assess the effect of D-chiro-inositol on the state of oxidative stress in the follicular fluid of women with PCOS. METHODS: Follicular fluids were obtained from women who have turned to the Center for Diagnosis and Treatment of Sterility of Obstetrics and Gynecology of the University Hospital of Siena and Modena diagnosed with PCOS. The women were treated with D-chiro-inositol (500 mg x 2 per day) for 3 months before being subjected to cycles of in vitro fertilization (IVF). The state of oxidative stress was measured by marking of free thiol groups of proteins in the follicular fluid with 3-(N-Maleimidopropionyl)-biocytin. RESULTS: In our study we obtained a lesser presence of free thiol protein groups equal to 77.8% in the follicular fluid of women with PCOS not treated with D-chiro-inositolo, compared to patients who instead have carried out such treatment. CONCLUSION: These results suggest that in PCOS women there is an increase of the oxidation of thiol groups of proteins follicular, correlated to a progressive increase of the oxidative stress and that the administration of D-chiro-inositol in patients with this disease seems to reduce the oxidation of thiol groups.

Myo-InositolTrisPyroPhosphate treatment leads to HIF-1α suppression and eradication of early hepatoma tumors in rats.

Myo-inositol trispyrophosphate (ITPP), a synthetic allosteric effector of hemoglobin, increases the regulated oxygen-releasing capacity of red blood cells (RBCs), leading to suppression of hypoxia-inducible factor 1α (HIF-1α) and to down-regulation of hypoxia-inducible genes such as vascular endothelial growth factor (VEGF). As a consequence, tumor growth is markedly affected. The effect of weekly intravenous injection of ITPP on an orthotopic, syngenic rat hepatocellular carcinoma (HCC) model was compared to that for untreated animals and animals subjected to conventional Doxorubicin chemotherapy. The longitudinal examination of HCC was performed by microCT imaging, and the cellular and molecular changes were evaluated by histology and Western blotting analysis of HIF-1α, VEGF, and caspase-3 gene expression in the tumor and in the surrounding liver. Hematologic impact was evaluated by blood cell-count measurement and determination of P50 (oxygen partial pressure for a 50 % oxygen saturation of hemoglobin). The HCC evaluation by microCT revealed a high potency of ITPP for tumor growth inhibition, thus allowing long-term survival and even cure of almost all the treated animals. The P50 value of hemoglobin in RBCs underwent a shift of 30 % following ITPP injection. Under these conditions, HIF-1α activity was strongly decreased, VEGF expression was down-regulated, and apoptosis was induced in HCC and surrounding liver cells, as indicated by Caspase-3 expression. ITPP did not affect hematologic parameters during treatment. The observations of in vivo tumor eradication suggest a significant clinical potential for ITPP in cancer therapy.

A novel inhibitor of the PI3K/Akt pathway based on the structure of inositol 1,3,4,5,6-pentakisphosphate.

BACKGROUND: Owing to its role in cancer, the phosphoinositide 3-kinase (PI3K)/Akt pathway is an attractive target for therapeutic intervention. We previously reported that the inhibition of Akt by inositol 1,3,4,5,6-pentakisphosphate (InsP(5)) results in anti-tumour properties. To further develop this compound we modified its structure to obtain more potent inhibitors of the PI3K/Akt pathway. METHODS: Cell proliferation/survival was determined by cell counting, sulphorhodamine or acridine orange/ethidium bromide assay; Akt activation was determined by western blot analysis. In vivo effect of compounds was tested on PC3 xenografts, whereas in vitro activity on kinases was determined by SelectScreen Kinase Profiling Service. RESULTS: The derivative 2-O-benzyl-myo-inositol 1,3,4,5,6-pentakisphosphate (2-O-Bn-InsP(5)) is active towards cancer types resistant to InsP(5) in vitro and in vivo. 2-O-Bn-InsP(5) possesses higher pro-apoptotic activity than InsP(5) in sensitive cells and enhances the effect of anti-cancer compounds. 2-O-Bn-InsP(5) specifically inhibits 3-phosphoinositide-dependent protein kinase 1 (PDK1) in vitro (IC(50) in the low nanomolar range) and the PDK1-dependent phosphorylation of Akt in cell lines and excised tumours. It is interesting to note that 2-O-Bn-InsP(5) also inhibits the mammalian target of rapamycin (mTOR) in vitro. CONCLUSIONS: InsP(5) and 2-O-Bn-InsP(5) may represent lead compounds to develop novel inhibitors of the PI3K/Akt pathway (including potential dual PDK1/mTOR inhibitors) and novel potential anti-cancer drugs.

Mechanism of attenuation of protein loss in murine C2C12 myotubes by D-myo-inositol 1,2,6-triphosphate.

D-myo-inositol 1,2,6-triphosphate (alpha trinositol, AT) has been shown to attenuate muscle atrophy in a murine cachexia model through an increase in protein synthesis and a decrease in degradation. The mechanism of this effect has been investigated in murine myotubes using a range of catabolic stimuli, including proteolysis-inducing factor (PIF), angiotensin II (Ang II), lipopolysaccharide, and tumor necrosis factor-alpha/interferon-gamma. At a concentration of 100 muM AT was found to attenuate both the induction of protein degradation and depression of protein synthesis in response to all stimuli. The effect on protein degradation was accompanied by attenuation of the increased expression and activity of the ubiquitin-proteasome pathway. This suggests that AT inhibits a signalling step common to all four agents. This target has been shown to be activation (autophosphorylation) of the dsRNA-dependent protein kinase (PKR) and the subsequent phosphorylation of eukaryotic initiation factor 2 on the alpha-subunit, together with downstream signalling pathways leading to protein degradation. AT also inhibited activation of caspase-3/-8, which is thought to lead to activation of PKR. The mechanism of this effect may be related to the ability of AT to chelate divalent metal ions, since the attenuation of the increased activity of the ubiquitin-proteasome pathway by PIF and Ang II, as well as the depression of protein synthesis by PIF, were reversed by increasing concentrations of Zn(2+). The ability of AT to attenuate muscle atrophy by a range of stimuli suggests that it may be effective in several catabolic conditions.

Enhanced exercise capacity in mice with severe heart failure treated with an allosteric effector of hemoglobin, myo-inositol trispyrophosphate.

A major determinant of maximal exercise capacity is the delivery of oxygen to exercising muscles. myo-Inositol trispyrophosphate (ITPP) is a recently identified membrane-permeant molecule that causes allosteric regulation of Hb oxygen binding affinity. In normal mice, i.p. administration of ITPP (0.5-3 g/kg) caused a dose-related increase in the oxygen tension at which Hb is 50% saturated (p50), with a maximal increase of 31%. In parallel experiments, ITPP caused a dose-related increase in maximal exercise capacity, with a maximal increase of 57 +/- 13% (P = 0.002). In transgenic mice with severe heart failure caused by cardiac-specific overexpression of G alpha q, i.p. ITPP increased exercise capacity, with a maximal increase of 63 +/- 7% (P = 0.005). Oral administration of ITPP in drinking water increased Hb p50 and maximal exercise capacity (+34 +/- 10%; P < 0.002) in normal and failing mice. Consistent with increased tissue oxygen availability, ITPP decreased hypoxia inducible factor-1alpha mRNA expression in myocardium. It had no effect on myocardial contractility in isolated mouse cardiac myocytes and did not affect arterial blood pressure in vivo in mice. Thus, ITPP decreases the oxygen binding affinity of Hb, increases tissue oxygen delivery, and increases maximal exercise capacity in normal mice and mice with severe heart failure. ITPP is thus an attractive candidate for the therapy of patients with reduced exercise capacity caused by heart failure.

Inositols prevent and reverse endothelial dysfunction in diabetic rat and rabbit vasculature metabolically and by scavenging superoxide.

Endothelial dysfunction (ED) is an early feature of cardiovascular risk and diabetes. Hyperglycemia and hyperlipidemia are causative factors. Excessive endothelial mitochondrial superoxide (ROS) production with hyperglycemia and hyperlipidemia is a key mechanism. Inositol components of an insulin inositol glycan mediator, d-chiro-inositol (DCI) and 3-O-methyl DCI (pinitol), decrease hyperglycemia and hyperlipidemia. We tested whether these, myoinositol and dibutyryl DCI (db-DCI), would prevent or reverse ED in diabetic rats and rabbits. Oral inositols reduced hyperglycemia and hypertriglyceridemia with different potencies and prevented ED in rat aortic rings and mesenteric beds. Inositols added in vitro to five diabetic tissues reversed ED. Relaxation by Ach, NO, and electrical field stimulation was potentiated by inositols in vitro in rabbit penile corpus cavernosa. Inositols in vitro restored impaired contraction by the eNOS inhibitor l-NAME and increased NO effectiveness. DCI and db-DCI decreased elevated ROS in endothelial cells in high glucose and db-DCI reduced PKC activation, hexosamine pathway activity, and advanced glycation end products to basal levels. Xanthine/xanthine oxidase generated superoxide was reduced by superoxide dismutase or inositols, with db-DCI efficacious in a mechanism requiring chelated Fe(3+). Histochemical examination of rat aortic rings for protein SNO demonstrated a decrease in diabetic rings with restoration by inositols. In summary, inositols prevented and reversed ED in rat and rabbit vessels, reduced elevated ROS in endothelial cells, potentiated nitrergic or vasculo-myogenic relaxations, and preserved NO signaling. These effects are related to their metabolic actions, direct superoxide scavenging, and enhancing and protecting NO signaling. Of the inositols tested, db-DCI was most effective.

Glycerophosphoinositols inhibit the ability of tumour cells to invade the extracellular matrix.

The naturally occurring phosphoinositide metabolite, glycerophosphoinositol 4-phosphate, has recently been shown to induce rearrangements in the actin cytoskeleton through modulation of the small GTPases, Rac and Rho. Since this is directly linked to cell spreading and remodelling, we have evaluated the potential role of glycerophosphoinositol 4-phosphate and related metabolites in tumour cell invasion. The biological effects of these compounds were tested in a number of cellular activities related to cell spreading, including cell migration and cell invasion. We find that unlike other inositol-containing molecules, such as the inositol phosphates, glycerophosphoinositol and glycerophosphoinositol 4-phosphate prevent the invasion of epithelium-derived MDA-MB-231 breast carcinoma and A375MM melanoma cell lines through the extracellular matrix; this is due to a decreased ability to degrade matrix components. These data identify a specific activity of the glycerophosphoinositols that can be exploited for their development as novel anti-invasive drugs.

Treatment of PCOS with metformin and other insulin-sensitizing agents.

A significant proportion of women with polycystic ovary syndrome (PCOS) suffer from insulin resistance and compensatory hyperinsulinemia. Growing evidence indicates that elevated serum insulin induces hyperandrogenism, which in turn leads to anovulation and infertility. Hyperinsulinemia also contributes to the increased risk for cardiovascular disorders and type 2 diabetes mellitus. These concepts provide a rationale for therapies focused on treatments of insulin resistance. Metformin is the most extensively studied insulin-sensitizing agent for the treatment of women with PCOS. Use of metformin leads to a decrease in serum insulin and androgen levels, as well as an improvement in ovulatory function. Other insulin-sensitizing agents studied in women with PCOS include troglitazone, rosiglitazone, pioglitazone, and D-chiro-inositol.

Effects of d-chiro-inositol in lean women with the polycystic ovary syndrome.

OBJECTIVE: To determine whether the administration of D-chiro-inositol, a putative insulin-sensitizing drug, would affect the concentration of circulating insulin, the levels of serum androgens, and the frequency of ovulation in lean women with the polycystic ovary syndrome. METHODS: In 20 lean women (body mass index, 20.0 to 24.4 kg/m 2) who had the polycystic ovary syndrome, treatment was initiated with either 600 mg of D-chiro-inositol or placebo orally once daily for 6 to 8 weeks. We performed oral glucose tolerance tests and measured serum sex steroids before and after therapy. To monitor for ovulation, we determined serum progesterone concentrations weekly. RESULTS: In the 10 women given D-chiro-inositol, the mean (+/- standard error) area under the plasma insulin curve after oral administration of glucose decreased significantly from 8,343 +/- 1,149 mU/mL per min to 5,335 +/- 1,792 mU/mL per min in comparison with no significant change in the placebo group (P = 0.03 for difference between groups). Concomitantly, the serum free testosterone concentration decreased by 73% from 0.83 +/- 0.11 ng/dL to 0.22 +/- 0.03 ng/dL, a significant change in comparison with essentially no change in the placebo group (P = 0.01). Six of the 10 women (60%) in the D-chiro-inositol group ovulated in comparison with 2 of the 10 women (20%) in the placebo group (P = 0.17). Systolic (P = 0.002) and diastolic (P = 0.001) blood pressures, as well as plasma triglyceride concentrations (P = 0.001), decreased significantly in the D-chiro-inositol group in comparison with the placebo group, in which these variables either increased (blood pressure) or decreased minimally (triglycerides). CONCLUSION: We conclude that, in lean women with the polycystic ovary syndrome, D-chiro-inositol reduces circulating insulin, decreases serum androgens, and ameliorates some of the metabolic abnormalities (increased blood pressure and hypertriglyceridemia) of syndrome X.