Growth Hormones

OR19-5

Effects of GH and Pioglitazone in Viscerally Obese Adults with Impaired Glucose Tolerance.

Hamdee Y Attallah*1,2, Andrew R Hoffman1,2. 1Med Svc, VA Palo Alto Hlth Care Syst, Palo Alto, CA; 2Dept of Med, Stanford Univ, Stanford, CA.

Adults with increased visceral adipose tissue (VAT) and impaired glucose tolerance (IGT) are at risk for developing diabetes, and VAT reduction can lower this risk .Thiazolidinediones (TZDs) and growth hormone (GH), when taken separately and for prolonged periods, have reduced VAT and improved insulin sensitivity in insulin-resistant adults. However, GH is rarely administered to people with abnormal glucose metabolism because of its short-term insulin antagonizing effects. Animal data indicate that addition of TZD prevents short-term GH-induced worsening of glucose metabolism through its potent insulin sensitizing effects. However, the short-term and long-term effects of combined TZD and GH treatment in humans are unknown. We studied the effects of GH and the TZD pioglitazone on VAT and insulin sensitivity in a double-blind, placebo-controlled trial. Sixty-two adults (46 men) with abdominal obesity and IGT received an injection and a pill: GH (Nutropin AQ® 8 mcg/kg/d, or placebo) and pioglitazone (Actos® 30 mg/d, or placebo) every day for 40 wk. At baseline, mean BMI was 36.2 and mean fasting glucose (FPG) and 2-hr pc glucose following a 75-gram oral glucose load were 109.4 mg/dl and 163.8 mg/dl, respectively. At baseline and 3-4 weeks following completion of treatment, VAT content was assessed by CT and insulin sensitivity was measured by the steady-state plasma glucose (SSPG) level during an insulin suppression test. Treatment with GH alone reduced VAT by 13.5 + 4.4 % (P<0.05 compared to self and placebo) but resulted in no significant change in SSPG. Treatment with pioglitazone alone lowered VAT by 6.4 + 5 % (p=NS) and reduced SSPG by 22.4 + 5.5 % (P<0.05). Combined therapy reduced VAT by 17.6 + 5 % (P<0.05) and SSPG by 13 + 7.5 % (P<0.05). Only GH alone modestly increased FPG during the first 4-8 weeks of treatment, but FPG quickly returned to baseline either spontaneously or after GH dose reduction. No significant changes in body weight were seen. This trial demonstrates that prolonged GH administration reduces VAT in abdominally obese, pre-diabetic adults but may lead to a transient rise in FPG during the first few weeks of treatment. In contrast, the addition of pioglitazone to GH treatment prevents the short-term diabetogenic effects of GH and leads to a significant reduction in VAT and an improvement in endogenous insulin sensitivity. These results suggest that the addition of pioglitazone to GH may have added benefit in the metabolic syndrome. Supported by Genentech, Inc.; Pfizer Corporation

CLINICAL - Growth Hormone (1:00 PM - 2:30 PM)

Presentation Date: 6/5/2005 Time: 1:30:00 PM Location: 30 B-C

Growth Hormones

OR19-5 News Summary

Growth hormone combined with glucose-lowering drug may prevent diabetes

The combination of a glucose-reducing drug and fat-reducing growth hormone treatment may prevent diabetes in adults with abdominal obesity and reduced insulin action, according to a new study being presented on Sunday, June 5, at The Endocrine Society’s 87th Annual Meeting in San Diego. Researchers found that this combined regimen reduced abdominal fat and improved insulin function in this group, which had not been possible with growth hormone alone.

Having too much excess fat in the abdomen is associated with a decrease in the functioning of insulin, a key hormone that helps regulate sugar levels in the blood. When insulin function is reduced, blood sugar levels tend to rise and diabetes may develop. Treatments that reduce abdominal fat and improve insulin action in obese adults may prevent diabetes in this population.

Growth hormone, a naturally occurring hormone produced in the body, can reduce abdominal fat by 18 percent to 20 percent or more in abdominally obese adults. However, growth hormone can cause an undesirable side effect — a temporary rise in blood sugar levels during the first four to eight weeks of treatment. A class of drugs called thiazolidinediones significantly improves insulin function in obese adults, both in the short and long term, but the combined effects of growth hormone and a thiazolidinedione in humans are unknown.

Drs. Hamdee Y. Attallah and Andrew R. Hoffman, of the VA Palo Alto Health Care System in Palo Alto, Calif., and Stanford University in Stanford, Calif., and colleagues examined the effects of growth hormone and a thiazolidinedione on abdominal adipose tissue and insulin function in 62 adults over a 40-week period. Participants were abdominally obese and pre-diabetic, meaning that their blood sugars were elevated but below the threshold for diabetes.

Each person received an injection and a pill. The injection was the growth hormone Nutropin AQ, and the pill was a thiazolidinedione called Actos. Participants were randomly assigned to one of four treatment groups: 1) Nutropin AQ plus Actos, 2) Nutropin AQ plus placebo, 3) placebo plus Actos, or 4) placebo plus placebo. Neither the participants nor the investigators knew what drug combination each subject received. At the beginning of the study and after 40 weeks of treatment, changes in abdominal adipose tissue and insulin function were measured.

Treatment with only growth hormone (group #2) significantly reduced abdominal adipose tissue by 13.5 percent, but with no change in insulin function. Treatment with only a thiazolidinedione (placebo plus Actos) reduced abdominal adipose tissue by 6.4 percent and improved insulin activity by 22.4 percent, the latter of which was significant. Combined therapy (Nutropin AQ plus Actos) significantly reduced abdominal adipose tissue by 17.6 percent and significantly improved insulin action by 13 percent. Prolonged treatment with growth hormone was able to reduce abdominal adipose tissue in abdominally obese, pre-diabetic adults, but, alone, also led to a temporary increase in fasting blood sugars during the first few weeks of treatment.

This research was funded by Genentech, Inc. and Pfizer Pharmaceuticals.

Growth Hormones

OR33-3

Pharmacokinetic and Safety Results of a Human Single-Dose Comparison of Somatropin Inhalation Powder (SIP) vs Subcutaneous (SC) Injection of Somatropin.

John Chipman*2, Richard Lucas2, Blair Jackson1, Charles Blizzard1, Tim Mant3, Ann Louise Cleverly2, Vanessa Spaldin2, Lloyd Johnston1, Gordon Cutler2. 1Alkermes Inc, Cambridge, MA; 2Eli Lilly and Co, Indianapolis, IN; 3Guy’s Drug Res Unit, Guy’s Hosp, London, UK.

Alternative methods for delivering hGH (somatropin) are under investigation because of the potential benefits associated with a reduction in parenteral injections associated with current therapy. We hypothesize that large proteins can be formulated to enhance delivery to the deep lung via the inhalation route by increasing particle size while lowering particle density. Such large porous particles are readily dispersible by a simple breath-actuated inhaler. As proof-of-principle, we have studied the pharmacokinetic characteristics of these new formulations as applied to SIP.

Twelve, healthy male subjects, ages 21-36 years, were enrolled in this crossover design study to receive either SC hGH or SIP. Between the two formulations, 11 adverse events were reported (5 for SC hGH, and 6 for SIP); all were mild in severity and none were associated with study drug.

During the SC phase, the geometric mean Cmax was 34.4 ng/ml, the geomean for AUC (0-) was 200 ng.h/mL, and the geomean T1/2 was 2.16 hours. By comparison, during the inhalation phase, the geometric mean Cmax for SIP was 36.1 ng/mL, the geomean AUC(0-) was 277 ng.h/mL, and the geomean T1/2 was 3.08 hours. The CV (range) for Cmax was 27% (20-55%) for SC hGH versus 35% (22-67%) for SIP. With the fixed dose regimen, variation in subject body weight accounted for approximately 50% of the variance in AUC (p=0.01). These results demonstrate that the Lilly/Alkermes inhaled hGH system can produce similar concentration-time profiles and variability to that of SC hGH injections. No significant side effects were associated with this acute exposure to SIP.

CLINICAL - Growth Hormone & Ghrelin (1:00 PM - 2:30 PM)

Presentation Date: 6/6/2005 Time: 1:00:00 PM Location: 20 A

Growth Hormones

OR33-3 News Summary

Inhaler shows promise in easing delivery of growth hormone medication

A simple and compact inhaler can deliver human growth hormone as safely and effectively as by injection, according to a new study being presented on Monday, June 6, at The Endocrine Society’s 87th Annual Meeting in San Diego.

Human growth hormone is a protein necessary for normal growth and development. Like virtually all protein-based drug therapies, growth hormone must be injected with a needle. Every day many parents give their children an injection of growth hormone to treat growth hormone deficiency or other medical conditions resulting in short stature. In addition, many adolescents and adults give themselves daily injections of growth hormone as prescribed by an endocrinologist.

Better ease in taking the medication would be a great advance for patients, and researchers are investigating technologies that may eliminate the need to inject growth hormone. Dr. John Chipman of Eli Lilly and Company of Indianapolis and colleagues from Eli Lilly, Alkermes Inc. in Cambridge, Mass., and Guy’s Hospital in London tested a new technology that uses an inhaler with a dry powder formulation of the human growth hormone, somatropin.

This early phase study showed that particles of inhaled growth hormone are absorbed into the bloodstream through the lung. This single-dose safety study was conducted in 12 healthy men, ages 21–36, and they received either somatropin inhalation powder (Humatrope®) or an injection of somatropin.

Blood levels of inhaled growth hormone were similar to blood levels of injected growth hormone. This study provides preliminary evidence that inhalation of proteins as large as growth hormone produce therapeutic blood levels similar to those obtained following injections. The side effects reported in this study were infrequent and mild, occurred at a similar rate with both inhalation and injection, and did not appear to be drug related.

The researchers note that larger studies are needed to understand fully the safety and effectiveness of delivering growth hormone by inhalation.

This research was funded by Eli Lilly and Company.

Growth Hormones

P2-449

Administration of Recombinant Human GHRH-1,44-amide for Three Months Reduces Abdominal Visceral Fat Mass and Increases Physical-Performance Measures in Postmenopausal Women.

Johannes D Veldhuis*1, James M Patrie2, Kirsten Frick3, Judith Y Weltman3, Arthur L Weltman3. 1Endocrinol, Mayo Clin, Rochester, MN; 2Hlth Eval Svcs, Univ of Virginia, Charlottesville, VA; 3Gen Clin Res Ctr, Univ of Virginia, Charlottesville, VA.

A recent study indicated that twice-daily sc administration of a high dose of recombinant human GHRH-1,44-amide (GHRH) for 90 days can alter body composition in healthy older men. No data establish whether this is also true in postmenopausal women. The present study tests the hypothesis that the same GHRH regimen applied in women will: (a) elevate both IGF-I and GH concentrations; and (b) reduce abdominal visceral-fat mass, augment total body water and enhance functional performance. To this end, 10 postmenopausal volunteers underwent baseline study and then received 1 mg GHRH twice daily sc for 3 mo. Statistical comparisons with preintervention baseline data revealed: (i) mean 98 ± 14 % elevation of overnight GH concentrations after administration of the peptide for 1 and 3 mo [P < 0.005]; (ii) sustained 71 ± 3.5% rise in IGF-I concentrations over the interval 2 wk-3 mo [P < 0.0012]; (iii) 16 ± 7% reduction in abdominal visceral-fat mass (P = 0.029) and 14 ± 5% increase in tritiated water space (P < 0.025); and (iv) abbreviation of the times required to walk 30 m (P = 0.015) and ascend 2 flights of stairs (P = 0.003). Most (70%) subjects experienced local skin reactivity. There were no systemic adverse events. We conclude that a 3-mo regimen of GHRH supplementation in postmenopausal women can stimulate GH and IGF-I production, reduce abdominal visceral fat, and improve selected measures of physical performance, while inducing significant local skin reactivity.

Supported by AG14799

CLINICAL - Growth Hormone I (11:00 AM - 12:00 PM and 2:30 PM - 3:30 PM)

Presentation Date: 6/5/2005 Time: 12:00:00 AM Location: Exhibit Hall

Growth Hormones

P2-449 News Summary

Hypothalamic peptide supplements in postmenopausal women can reduce abdominal fat

Researchers found that hypothalamic peptide supplementation in postmenopausal women can stimulate growth hormone (GH) and insulin-like growth factor-1 (IGF-1) production, reduce intra-abdominal fat, and improve selected measures of physical performance, according to a study to be presented on Sunday, June 5, at The Endocrine Society’s 87th Annual Meeting in San Diego.

Hypothalamic peptides, or growth hormone–releasing hormone (GHRH), is a hormone produced in the hypothalamus that promotes production of human growth hormone. GH is the primary hormone responsible for growth, and it helps regulate metabolic processes as anabolism — the active part of metabolism — and lipolysis — the breakdown of fat. Normal human aging is associated with decreased GH secretion. Average GH level in those over the age of 60 is about half of that in young adults. The reduction in GH levels with aging is believed to contribute to age-related decreases in muscle mass and strength and decreased lipolysis. The effects of GH are largely mediated via IGF-1.

A recent study indicated that twice-daily administration of a high dose of recombinant human GHRH for 90 days can alter body composition in healthy older men. However, no similar data exists for postmenopausal women so Dr. Johanne D. Veldhuis, of the Mayo Clinic in Rochester, Minn., and colleagues at the University of Virginia in Charlottesville designed a study to investigate this issue.

Ten postmenopausal volunteers underwent baseline study and then received 1 mg of GHRH twice daily for three months. Most participants — 70 percent — experienced local skin reactivity. There were no systemic adverse events. Researchers found that the GHRH supplementation in postmenopausal women stimulated GH and IGF-1 and altered body composition in women.

Growth Hormones

P2-451

Positive Effects of a Physiologic Dose of GH on Markers of Atherogenesis: A Placebo-Controlled Study in Patients with Adult-Onset GH Deficiency.

Jens Bollerslev*1, Thor Ueland1, Anders P Jorgensen2, Kristian J Fougner3, Ragnhild Wergeland4, Kristin Godang1, Thomas Schreiner1,2, Pia Burman5. 1Sect of Endocrinol, The Natl Hosp, Oslo, Norway; 2Dept of Endocrinol, Aker Univ Hosp, Oslo, Norway; 3Med Dept, Sect of Endocrinol, St Olva’s Hosp, Trondheim Univ Hopsital, Trondheim, Norway; 4Dept of Clin Chem, The Natl Hosp, Oslo, Norway; 5Endocr Care, Pfizer Inc, New York, NY.

Background: Patients with growth hormone deficiency (GHD) display a cluster of vascular risk factors, such as visceral adiposity, lipoprotein disturbances, endothelial dysfunction, and insulin resistance, and increased carotid intima–media thickness. Furthermore, these patients have been reported to be at increased risk for death from vascular causes. The purpose of this study was to investigate the impact of physiologic GH substitution on a variety of cardiovascular risk factors representing different aspects of atherogenesis, including lipoproteins (apo A, apo B), inflammatory markers (CRP and IL-6), and markers of endothelial dysfunction (ICAM-1, vWF, sCD40L).

Materials and Methods: Fifty-five patients with previously untreated adult-onset GHD (mean age, 49 years) were enrolled in a placebo-controlled crossover study. GH therapy and placebo were administered for 9 months, each separated by a 4-month washout period. GH therapy was individually dosed to obtain an insulin-like growth factor-1 (IGF-1) concentration within the normal range for age and sex. The direct effect of GH therapy compared with placebo was estimated by the crossover effect calculated by the difference between GH and placebo and expressed as mean values and 95% confidence intervals. Blood samples were analyzed by routine clinical chemistry panels or immunoassays.

Results: The final mean dose of GH was 0.6 mg for women and 0.4 mg for men (P < .03); these doses led to similar concentrations of IGF-I in men and women. Compared with placebo, GH substitution had a significant effect on apo B (mean change –0.15 mg/L [–0.22, –0.08]), apo B/apo A ratio (–0.14 [–0.20, –0.08]), and CRP (–1.8 mg/L [-3.3, -0.3]). No significant effects were observed on IL-6 (0.42 pg/mL [–0.10, 0.96]), ICAM-1 (–18 ng/mL (–47, 10]), apo A (0 mg/L [–0.08, 0.09]), vWF (8.4% (–3.3, 20.3]), or sCD40L (2 pg/mL [–39, 43]).

Conclusion: In treatment-naive patients with GHD, GH substitution at low, physiologic, individually titrated doses was accompanied by significant reductions in atherogenic lipoprotein and CRP concentrations. This study suggests a beneficial effect of GH on cardiovascular risk in patients with GHD.

This study was supported by Pfizer Inc.

CLINICAL - Growth Hormone I (11:00 AM - 12:00 PM and 2:30 PM - 3:30 PM)

Presentation Date: 6/5/2005 Time: 12:00:00 AM Location: Exhibit Hall

Growth Hormones

P2-451 News Summary

Growth hormone treatment may reduce risk of developing heart disease in certain patients

In certain patients, growth hormone (GH) therapy may reduce risk factors related to cholesterol as well as markers of arterial inflammation, possibly leading to a decreased risk of developing ischemic heart disease, according to a new study being presented on Sunday, June 5, at The Endocrine Society’s 87th Annual Meeting in San Diego. In addition, say researchers, these markers may be used to monitor the effect of treatment with GH in GH-deficient patients and help identify individuals who may benefit from more aggressive treatment.

Patients with deficient GH production have many risk factors associated with heart disorders. If left untreated, they are at increased risk of developing and dying from ischemic heart disease. Risk factors for developing heart disease are often measured in the blood and can be used to monitor and identify patients at high risk.

GH-deficient patients are treated with GH. Therefore, Dr. Jens Bollerslev, of The National Hospital in Oslo, Norway, and other Norwegian colleagues, wanted to investigate the impact of such treatment on a variety of cardiovascular risk factors representing different aspects of ischemic heart disease development. The factors analyzed included lipoproteins (ApoA, ApoB) and endothelial (ICAM-1, vWF, sCD40L) and inflammatory markers (IL-6, CRP) and represent different pathological pathways all leading to the development of the disease.

Fifty-five patients with GH deficiency acquired in adulthood were enrolled in a placebo-controlled study. On average, the participants were 49 years old. GH and placebo were administered for nine months each. Blood samples were analyzed by routine clinical chemistry or immunoassays. Immunoassays use an enzyme-bound specific antibody to detect the substance of interest. The enzyme catalyzes a color reaction when exposed to substrate, which can be quantified.

During GH substitution, but not placebo treatment, a significant decrease was observed for ApoB and CRP but not the other risk markers. This treatment, say researchers, could be specifically aimed at changing the activated pathways that lead to the development of ischemic heart disease.

This study was funded by Pfizer Inc.

IGFs

P2-697

Adult-Onset Growth Hormone and IGF-1 Deficiency Reduces Neoplastic Disease, Delays Age-Related Pathology and Increases Lifespan.

William E Sonntag*1,6, Christy S Carter1, Yuji Ikeno2, Kari Ekenstedt3, Cathy Carlson3, Richard Loeser4, Shuko Lee5, Colleen Bennett1, Rhonda Ingram1, Tracy Moore1. 1Dept of Physiol and Pharmacol, Wake Forest Univ Hlth Scis, Winston-Salem, NC; 2Dept of Cell and Struct Biol, Univ of Texas Hlth Sci Ctr at San Antonio, San Antonio, TX; 3Dept of Vet Population Med, Univ of Minnesota, St. Paul, MN; 4Depts of Biochem and Rheumatol, Rush Med Coll, Chicago, IL; 5Res Svc, Dept of VA Med Ctr, San Antonio, TX; 6Roena Kulynych Ctr for Memory and Cognition Res, Wake Forest Univ Hlth Scis, Winston-Salem, NC.

Disruption of the insulin/IGF-1 pathway increases lifespan in invertebrate models. However, the consequences of decreased IGF-1 signaling in mammals remain controversial since all models exhibit impairments in multiple endocrine systems(1). Using a rodent model with a specific and limited deficiency of growth hormone (GH) and IGF-1 (the dw/dw rat), we report that GH and IGF-1 deficiency throughout life (GHD - GH/IGF-1 deficient) has no effect on lifespan compared to normal, heterozygous animals. However, limited treatment of deficient animals with GH (200g, twice daily) from 4 to 14 weeks of age only (Adult-onset GH/IGF-1 deficiency - AO-GHD) increased median and maximal lifespan by 14 and 12%, respectively (p<0.001 each). Analysis of end-of-life pathology indicated that deficiency of these hormones decreased tumor incidence by 18 and 30% and reduced the number of fatal tumors by 36 and 45%, in GHD and AO-GHD animals, respectively, compared to heterozygous animals. GHD and AO-GHD decreased the severity of, and eliminated deaths from, chronic nephropathy (p<0.001 each). Total disease burden was reduced by 24% in GHD and 16% in AO-GHD. Importantly, the incidence of thrombus and intracranial hemorrhage increased by 154 and 198% in GHD and AO-GHD animals, respectively, compared to heterozygous animals. Deaths from thrombus and intracranial hemorrhage were delayed by 14 weeks in AO-GHD accounting for the increased lifespan compared to GHD animals. High levels of GH/IGF-1 around puberty were necessary to maximize reproductive fitness (successful pregnancies and number of offspring) as well as growth of offspring early in life and maintain cognitive function and prevent cartilage degeneration throughout life. These studies demonstrate the pleiotropic nature of GH/IGF-1. In contrast to previous reports, our results demonstrate that deficiencies in GH/IGF-1 alone are not sufficient to increase lifespan in mammalian models. Differences between our results and others are likely related to the use of animal models susceptible to neoplastic disease or result from the use of animals with multiple endocrine pertubations that have independent and/or synergistic effects on lifespan. The diverse effects of GH/IGF-1 throughout life are consistent with a model of antagonistic pleiotropy and demonstrate that, in response to a deficiency of these hormones, decreased pathology and increased lifespan is derived at the expense of functional impairment and tissue degeneration.

1. Carter, C. S., Ramsey, M. M. & Sonntag, W. E. (2002) Trends in Genetics 18, 295-301. Supported by NIH grants P01AG11370 and R01AG19392 to WES; American Federation of Aging Research/Pfizer grant and Claude D. Pepper Older Americans Independence Center 5P60AG10484 to CSC and RO1RR14099 to CC

BASIC/CLINICAL - Insulin-like Growth Factors I (11:00 AM - 12:00 PM and 2:30 PM - 3:30 PM)

Presentation Date: 6/5/2005 Time: 12:00:00 AM Location: Exhibit Hall

IGFs

P2-697 News Summary

Suppression of insulin-like growth factor-1 and growth hormone shows promise in delaying onset and progression of certain cancers

The long-term suppression of growth hormone and insulin-like growth factor-1 (IGF-1) reduced the incidence of cancer in rats and may be a future therapeutic target to decrease cancer risk in people, according to a new study to be presented on Sunday, June 5, at The Endocrine Society’s 87th Annual Meeting in San Diego.

Suppression of IGF-1 also may decrease cancer risk in those at high risk and, perhaps, could be a preventive measure, say researchers. Although additonal research is needed, currently available drugs, such as somotostatin analogs, may be useful in lowering plasma IGF-1 and delaying and/or preventing the onset of disease and increasing lifespan, especially in high risk people.

IGF-1 is an important blood-borne factor that increases cell growth and prevents cell death and has been proposed to be a factor in the initiation of many cancers, including lung, gastrointestinal, and prostate. Elevated IGF-1 levels in prememopausal women have been demonstrated to be a risk factor for breast cancer. IGF-1 in the blood may act as a tumor promoter during the early development of cancer.

Dr. William E. Sonntag, of Wake Forest University Health Sciences in Winston-Salem, N.C., and colleagues at Wake Forest and in Chicago, San Antonio, and St. Paul, Minn., previously reported that rats with elevated levels of growth hormone, which increases IGF-1 levels, exhibit an increase in chemical-induced mammary tumors. Dwarf animals with 50 percent lower IGF-1 levels do not develop tumors in response to the chemical carcinogen. If these dwarf rats are given growth hormone to increase IGF-1 in the blood, tumors develop at the same rate as in the normal animals. The investigators concluded that suppression of IGF-1 activity inhibits the growth of numerous cell types and cancers.

In addition, previous studies in some animals indicate that a reduction in IGF-1 activity may increase lifespan but the specific mechanism has been unclear. To date, there are no studies of a specific suppression of IGF-1 on aging or age-related diseases. Therefore, they developed a novel method to reduce IGF-1 in adult animals. Analysis of pathology at the end of the normal lifespan in IGF-1 deficient and normal animals indicated that a decrease of these hormones significantly reduced tumor incidence and the number of fatal tumors. Growth hormone and IGF-1 deficiency substantially decreased the severity of chronic kidney disease. These deficiencies, however, had no effect on physical performance and a modest effect on cognitive function and reproduction. The decrease in cancer resulted in a 12- to 15-percent increase in lifespan.

This study in rats suggests that a modest suppression of growth hormone and/or IGF-1, beginning in early adulthood, will delay the onset and/or progression of several types of cancer. The researchers believe the same will be true in humans.

This study was funded by the National Institute on Aging.

Growth Factors and Cytokines

P3-127

Potent Inhibition of Human Pancreatic Cancer Cell Growth by Beta-Interferon.

Giovanni Vitale*1, Casper H Van Eijck2, Peter M Van Koetsveld1, Ernst J Speel3, Annamaria Colao4, Gaetano Lombardi4, Katy Van der Wansem1, Joris I Erdmann1,2, Steven WJ Lamberts1, Leo J Hofland1. 1Dept of Intern Med, Erasmus MC, Rotterdam, Netherlands; 2Dept of Surg, Erasmus MC, Rotterdam, Netherlands; 3Dept of Molec Cell Biol, Univ of Maastricht, Maastricht, Netherlands; 4Dept of Molec and Clin Endocrinol and Oncol, Federico II Univ of Naples, Naples, Italy.

Chemotherapy and radiotherapy have a marginal role in the management of pancreatic cancer. Therefore, novel therapeutic strategies are needed. We evaluated the role of type I interferons (IFNs) and their receptors in the regulation of cell growth in 3 human pancreatic cancer cell lines (BxPC-3, MiaPaCa-2 and Panc-1).

In all 3 cell lines the effects of IFN-alpha and IFN-beta on cell proliferation and apoptosis were evaluated through DNA measurement (HoechstTM 33258) and DNA fragmentation (Cell Death Detection ELISAPlus, Roche), respectively. The mRNA expression of the two type I IFN receptors (IFNAR-1 and IFNAR-2, short and long form), as well as of IFN-beta mRNA, were evaluated by real time quantitative RT-PCR.

The treatment with IFN-beta (1-1000 IU/ml) for 6 days showed a very potent inhibitory effect on the proliferation of BxPC-3 (IC50: 8 IU/ml; maximal inhibition: 97%) and MiaPaCa-2 (IC50: 50 IU/ml, maximal inhibition: 88%) cells. The inhibitory effect of IFN-beta was dose- and time dependent and significantly stronger than IFN-alpha (1-1000 IU/ml). IFN-alpha did not induce DNA fragmentation at any concentration up to 1000 IU/ml in all 3 cell lines after 24 hours of incubation, while a dose-dependent induction of apoptosis was observed in BxPC-3 and MiaPaCa-2 after IFN-beta treatment. After 72 hours both IFN-alpha and IFN-beta stimulated apoptosis in BxPC-3 and MiaPaCa-2, but the induction following IFN-beta resulted to be more potent than IFN-alpha. The stimulation of apoptosis seems to be the main mechanism involved in the antitumour activity of IFN-beta, as showed by the strong positive correlation (r2 = 0.9, p<0.0001) between the cell proliferation inhibition and DNA fragmentation following the incubation with IFN-beta in BxPC-3 and MiaPaCa-2 cell lines. A moderate anti-proliferative effect without an increase in apoptosis was observed in Panc-1 after the treatment with IFN-alpha or IFN-beta. Type I IFN receptors mRNA were expressed in the 3 cell lines. The expression of active subunits (IFNAR-1 and IFNAR-2 long form) mRNA was significantly higher in BxPC-3. IFN-beta mRNA was detected in BxPC3 only.

In conclusion, IFN-beta has a potent anti-proliferative effect on pancreatic cancer cell lines via inducing an early apoptosis, particularly in BxPC-3, a moderately well differentiated cell line. The high mRNA expression of AR-1 and AR-2c subunits in BxPC3 could partially explain the major sensitivity of this cell line to IFN treatment.

BASIC - Aspects of Growth Factors & Cytokines (11:00 AM - 12:00 PM and 2:30 PM - 3:30 PM)

Presentation Date: 6/6/2005 Time: 12:00:00 AM Location: Exhibit Hall

Growth Factors and Cytokines

P3-127 News Summary

Interferon-beta may be effective treatment for aggressive pancreatic cancer

Interferon-beta has potential to be a potent treatment for pancreatic cancer, one of the most aggressive tumors in medicine, according to a laboratory study of human cancer cells being presented on Monday, June 6, at The Endocrine Society’s 87th Annual Meeting in San Diego.

Pancreatic adenocarcinoma is a highly aggressive malignancy. It is the fourth male and fifth female cause of cancer death in the Western world. Surgery could be the curative therapy, but only 5 percent to 20 percent of patients are surgical candidates at the time of the diagnosis. Even in this selected group of patients, only 25 percent can hope to survive for five years. Chemotherapy and radiotherapy have only a marginal role in the management of pancreatic adenocarcinoma. For these reasons, novel therapeutic strategies are needed.

Dr. Giovanni Vitale, of Erasmus Medical Center in Rotterdam, Netherlands, and colleagues in the Netherlands and Italy evaluated the role of type I interferons (IFNs) and their receptors in the regulation of cell growth in three human pancreatic cancer cell lines (BxPC-3, MiaPaCa-2 and Panc-1).

Interferons are cytokines initially identified for their ability to modulate antiviral response of cells. They are also implicated in cell differentiation, cell growth control, immune response, and they play an important role in anti-tumor defense. In fact, interferon-alpha is the most used cytokine in the treatment of several solid tumors. In pancreatic cancers, these cytokines are poorly expressed. Therefore, in relation to the defensive function of interferons against tumors, the absence of interferons expression could have an important function in the pathogenesis and, probably, in the treatment of pancreatic adenocarcinoma.

After six days of treatment, interferon-alpha and interferon-beta induced a very strong inhibition of the growth in all three cell lines. The antitumor effect of interferon-beta was considerably more potent than interferon alpha. This effect seems to be prevalently mediated by the induction of the programmed cell death, called apoptosis, particularly in BxPC-3 and MiaPaCa-2 cell lines. Besides, the researchers observed a clear difference between the cell lines in the sensitivity of interferons treatment: BxPC-3 showed the higher sensitivity, while Panc1 appeared to be the most resistant. This could be explained by the higher expression of receptors for interferon in BxPC-3 than in Panc-1.

This study was partially funded by the Union Internationale Contre le Cancer.