[Analysis on adult health life expectancy in Shanghai].

Objective: To investigate health status and calculate health life expectancy (HE) of residents in Shanghai, analyze health related factors and provided foundation of health policy. Methods: A multi-stage stratified random sampling was used to obtain self-reported health survey in Shanghai. WHO questionnaire was used to evaluate the health quality of life which was designed for the world health survey, Sullivan's method was used to calculate HE. Results: The self-assessment disability measure for adults over 18 years old in Shanghai was 0.25, higher for women (0.28) than for men (0.23). LE was 65.76 years for adults over 18 years old, higher for women (68.22) than for men (63.39). HE for adults over 18 years old was 47.99 years old, higher for men (49.05) than women (47.14). HE's proportion in LE gradually decreases with age. It accounts for 72.97% in the 18 years old and 39.00% in the 85 years old. Conclusions: The health of adult male in Shanghai is higher than that of female, and the proportion of HE loss of elderly is higher than young people. It is necessary to focus on the aging problem and strengthen the long-term care and health support system for the elderly. Improve the prevention and control of major diseases such as chronic diseases,which affect the quality of life expectancy seriously. Promotes the health level and quality of life in Shanghai.

[Analysis on the difference between life expectancy and healthy life expectancy in Shanghai].

Objective: To analyze the difference of life expectancy and healthy life expectancy among Shanghai residents of different gender and age groups. Methods: Compare the trends of life expectancy among Shanghai and other longevity countries/regions. With the disability weights of GBD, Sullivan method was applied to calculate the healthy life expectancy in Shanghai and analyze the loss of healthy life years among the population of different age groups and genders. Results: In the past 40 years, life expectancy had increased by 10.86 years in Shanghai. In 2016, the life expectancy of Shanghai residents was 83.18 years old, and 80.83 years old for males and 85.61 years old for females. The healthy life expectancy of Shanghai residents was 69.46 years, and 68.68 years for males and 70.23 years old for females. The gap with life expectancy was 13.72 years old, 12.15 years old and 15.38 years old, respectively. They account for 16.49%, 15.02% and 17.97% of life expectancy, respectively. The healthy life expectancy of women in all age groups is higher than that of men with the average gap of 1.76 years. The difference between the two is as small as 1.36 years at 20-24 years old, and as large as 2.24 years at 70-74 years old. The loss rate of healthy life expectancy increases with age, with women higher than men before age 65 and vice versa after age 65 years old. Conclusions: The life expectancy in Shanghai has reached the world leading level, but the healthy life loss is still large. It is necessary to further improve the life quality with the reducing mortality rate, especially for women and men over 65 years old.

Inhibitory effect of bombesin receptor antagonist RC-3095 on the growth of human pancreatic cancer cells in vivo and in vitro.

In this study, we investigated the effect of bombesin/GRP antagonist RC-3095 on the growth of CFPAC-1 human pancreatic cancer cells transplanted to nude mice or cultured in vitro. Nude mice bearing xenografts of the CFPAC-1 cell line received s.c. injections of RC-3095 (10 micrograms twice a day) or the vehicle (control) for 25 days. Chronic administration of RC-3095 inhibited the growth of CFPAC-1 tumors in nude mice as shown by a significant decrease in tumor volume throughout the period of treatment. Tumor volume doubling time was prolonged by RC-3095 treatment from 7.2 days to 10 days, and the tumor growth rate was decreased by 49%. In mice treated with RC-3095, the tumor growth delay time was 5.8 days. Treatment with RC-3095 decreased the final tumor weight by 37% and reduced DNA and protein contents in tumor tissues by 44 and 39.9%, respectively, compared to the controls. In cultures of the CFPAC-1 cell line, the addition of bombesin(1-14) (1 pM-0.1 microM) to the medium induced a dose-dependent increase in cell number. RC-3095 at 1 nM concentration effectively inhibited the bombesin-stimulated growth of CFPAC-1 cells in cultures. In the presence of 1 microM RC-3095 in the culture medium, the bombesin-induced growth of CFPAC-1 cells was totally suppressed. Bombesin was also shown to stimulate the DNA synthesis in CFPAC-1 cells in vitro as based on [3H]thymidine incorporation assay. When the cells were cultured in the presence of 1-100 nM bombesin, the uptake of [3H]thymidine by the cells was increased by 89-131%. RC-3095 inhibited both the basal and bombesin-stimulated DNA synthesis of CFPAC-1 cells. Addition of RC-3095 (10-100 nM) alone to the cultures caused a 39-40% decrease in the [3H]thymidine incorporation by the cells. Concomitant addition of RC-3095 (1 microM) and bombesin (1-100 nM) to the cultures induced a significant reduction in the uptake of [3H]thymidine by the cells compared to the values obtained with bombesin alone. Receptor binding assays showed the presence of two classes of specific binding sites for bombesin on CFPAC-1 cells, one with high affinity (Kd = 4.25 +/- 0.77 nM) and low capacity (Bmax = 0.268 +/- 0.052 pmol/10(6) cells) and the other with low affinity (Kd = 321.70 +/- 68.46 nM) and high capacity (Bmax = 3.991 +/- 0.374 pmol/10(6) cells).(ABSTRACT TRUNCATED AT 400 WORDS)

Inhibitory effect of bombesin/gastrin-releasing peptide antagonist RC-3095 and high dose of somatostatin analogue RC-160 on nitrosamine-induced pancreatic cancers in hamsters.

Female Syrian golden hamsters with N-nitrosobis(2-oxopropyl)amine-induced pancreatic cancers were treated for 2 months with new pseudononapeptide bombesin receptor antagonist [D-Tpi6,Leu13 psi (CH2NH)-Leu14]bombesin(6-14)(RC-3095), administered s.c. with implanted osmotic minipumps releasing 20 micrograms/day of the analogue. The results were compared to those obtained by treatment with somatostatin analogue RC-160 (35 micrograms/day and 150 micrograms/day) or [D-Trp6]luteinizing hormone-releasing hormone (25 micrograms/day), which inhibited the growth of pancreatic cancers in our previous studies. A new acetylated somatostatin analogue [formula: see text] (30 micrograms/day) also was used for comparison of therapeutic response. All peptide analogues induced tumor inhibition by at least one of the measured parameters. Bombesin antagonist RC-3095 and high dose of RC-160 (150 micrograms/day) had the greatest inhibitory effect on pancreatic cancers: A significant decrease in the number of animals with tumors, reduced pancreatic weight, 87-89% inhibition of tumorous pancreas weight, and a significant diminution in the number of tumor nodules and argyrophilic nucleolar organizer region count in tumor cell nuclei were observed in the groups treated with these regimens. We were able to detect receptors for bombesin in membranes of N-nitrosobis(2-oxopropyl)amine-induced pancreatic tumors and these receptors were not down-regulated after treatment with the bombesin antagonist. In hamsters treated with bombesin antagonists, tumor inhibition might be explained by a significant decrease in the binding capacity of epidermal growth factor receptors in pancreatic cancers. The acetylated somatostatin analogue RC-160-II had a similar inhibitory effect on the tumors as the original analogue RC-160. Our results suggest that the increase in the dose of RC-160 improves the therapeutic response, and this finding should be taken into account in clinical use of this somatostatin analogue. In view of its strong inhibitory effect on experimental pancreatic tumors, the bombesin antagonist RC-3095 might be considered as a possible new agent for the therapy of human exocrine pancreatic cancer.

Evaluation of receptors for somatostatin in various tumors using different analogs.

The binding characteristics of several somatostatin (SS-14) analogs developed in our laboratory were examined in various human and animal tumors and normal tissues. In rat cerebral cortex and human breast cancer membranes the interaction of SS-14 with its binding sites was rapid, specific, saturable, linear with protein concentrations, and dependent on time and temperature. Analysis of kinetic and equilibrium experimental data showed that the interaction of [125I-Tyr11]SS-14 with the binding sites in all normal and tumoral tissue specimens was consistent with the presence of a single class of noncooperative binding sites. Superactive octapeptide analogs of somatostatin-containing hexapeptide sequences Cys-Phe-D-Trp-Lys-Thr-Cys or Cys-Tyr-D-Trp-Lys-Val-Cys showed significant binding affinities to SS-14 receptors. Among these analogs, D-Trp-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-NH2 (RC-98-I) showed the highest binding affinity to normal human pancreatic tissue and human pancreatic adenocarcinoma. In contrast, Sandostatin (SMS 201-995) bound only to normal pancreas, not to human pancreatic cancers. Analog RC-98-I also showed a high binding to human and rat prostate cancers. In human epithelial ovarian cancers and an arrhenoblastoma, analogs D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Trp-NH2 (RC-95-I), D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (RC-121) and D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) appeared to be the most potent in displacing labeled SS-14. Analogs Ac-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-NH2 (RC-101-I) as well as RC-121, RC-160, and RC-95-I, but not SMS-201-995, showed high binding affinity in human breast cancers. In specimens of human meningioma the highest binding was found with analogs RC-121, RC-95-I, and RC-101-I. Since marked variations in binding affinities were noted for several analogs in the tissues of origin and the tumors, this suggest that differences may exist between somatostatin receptors not only in normal vs. cancerous tissues, but also among various tumors. Our findings also imply that some analogs could be therapeutically superior to others in the treatment of certain tumors.

Inhibition of growth of MDA-MB-231 human breast cancer xenografts in nude mice by bombesin/gastrin-releasing peptide (GRP) antagonists RC-3940-II and RC-3095.

Bombesin or gastrin-releasing peptide (GRP) may act as autocrine growth factors and play a role in the initiation and progression of breast cancer. We investigated the effect of bombesin/GRP antagonists RC-3095 and RC-3940-II on the growth of the MDA-MB-231 oestrogen-independent human breast cancer cell line xenografted into female nude mice. Bombesin/GRP antagonists, RC-3095 and RC-3940-II, were administered subcutaneously twice daily at a dose of 10 micrograms for 5 weeks. The growth of MDA-MB-231 tumours was inhibited during the treatment, as shown by a reduction in tumour volume. RC-3940-II and RC-3095 significantly decreased the final tumour volume by 72.4% and 57.7%, respectively, and greatly reduced tumour weights. RC-3940-II also significantly increased tumour doubling time and appeared to be more effective than RC-3095 in inhibiting the growth of MDA-MB-231 breast cancers. Serum gastrin and insulin-like growth factor-I (IGF-I) levels in animals treated with RC-3095 or RC-3940-II showed no significant changes as compared with controls. There was a significant decrease in the number of binding sites for epidermal growth factor (EGF), as well as bombesin, in tumour cells after chronic treatment with RC-3095 or RC-3940-II, which might be related to inhibition of tumour growth. Reverse transcription polymerase chain reaction, followed by Southern blot analysis, also showed a reduction in the expression of mRNA for EGF receptors in the group treated with RC-3940-II. Our findings suggest that bombesin/GRP antagonists such as RC-3095 or RC-3940-II could be considered for endocrine therapy for oestrogen-independent breast cancers, but further investigations are necessary.

Inhibition of growth of androgen-independent DU-145 prostate cancer in vivo by luteinising hormone-releasing hormone antagonist Cetrorelix and bombesin antagonists RC-3940-II and RC-3950-II.

The aim of this study was to test the antagonist of LH-RH (Cetrorelix), agonist [D-Trp6]LH-RH (triptorelin) and new bombesin antagonists RC-3940-II and RC-3950-II for their effect on the growth of an androgen-independent prostate cancer cell line, DU-145, xenografted into nude mice. Xenografts were grown in male nude mice, and after 4 weeks, the animals were treated either with saline (control) or with one of the analogues. One group of mice was given a combination of Cetrorelix and RC-3950-II. Treatment was given for 4 weeks. Tumour and body weights, and tumour volumes were measured. At sacrifice, tumours were dissected for histological examination and receptor studies. Serum was collected for measurement of hormone levels. The final tumour volume in control animals injected with saline was 577 +/- 155 mm3 and that of animals treated with Cetrorelix only 121.4 +/- 45 mm3 (P < 0.01). Bombesin antagonists RC-3940-II and RC-3950-II also significantly reduced DU-145 tumour volume in nude mice to 84.9 +/- 19.9 and 96.8 +/- 28 mm3, respectively. Agonist [D-Trp6]LH-RH did not significantly inhibit tumour growth. Serum levels of LH were decreased to 0.08 +/- 0.02 ng/ml (P < 0.05) in the Cetrorelix treated group as compared to 1.02 +/- 0.1 ng/ml for the controls, and testosterone levels were reduced to castration levels (0.01 +/- 0.01 ng/ml). Specific receptors for EGF and LH-RH in DU-145 tumours were significantly downregulated after treatment with Cetrorelix, RC-3940-II and RC-3950-II. Although LH-RH could be a local regulator of growth of prostate cancer, the fall in LH-RH receptors is not fully understood and the inhibitory effects of Cetrorelix and bombesin antagonists on DU-145 tumour growth might be attributed at least in part to a downregulation of EHF receptors. Since Cetrorelix and bombesin antagonists inhibit growth of androgen-independent DU-145 prostate cancers, these compounds could be considered for the therapy of advanced prostate cancer in men, especially after relapse.

Bombesin antagonists inhibit in vitro and in vivo growth of human gastric cancer and binding of bombesin to its receptors.

We investigated the effect of bombesin/gastrin-releasing peptide (GRP) antagonist RC-3095 and other analogs on the growth of Hs746T human gastric cancer cells implanted in nude mice or cultured in vitro and on the binding of bombesin to its receptors. Nude mice bearing xenografts of the Hs746T cell line received s.c. injections of RC-3095 (10 micrograms twice daily) or the vehicle (control) for 21 days. Administration of antagonist RC-3095 inhibited the growth of Hs746T tumors. Treatment with RC-3095 produced a significant decrease in tumor volume, prolonged the tumor volume doubling time from 3.6 days to 5.1 days, and decreased the tumor growth rate by 76.9%. The tumor growth delay time in mice treated with RC-3095 was 2.8 days. Treatment with RC-3095 also decreased the final tumor weight by 88.3% and reduced DNA and protein contents in tumors by 91.5% and 89.5%, respectively, as compared to controls. The presence of specific receptors for bombesin/GRP was investigated on the crude membranes of implanted tumors of Hs746T cells. Saturation binding assays showed that the binding of [125I-Tyr4]bombesin to the membranes was saturable and reversible. Scatchard analysis indicated the presence of a single class of binding sites with a high affinity (Kd = 0.24 +/- 0.07 nM) and a low binding capacity (Bmax = 57.0 +/- 0.9 fmol/mg protein). In displacement studies, the binding of [125I-Tyr4]bombesin was inhibited in a dose-dependent manner by unlabelled bombesin(1-14), [Tyr4]-bombesin and GRP (14-27), but not by structurally unrelated peptides. Synthetic bombesin/GRP antagonists RC-3095, RC-3110, and RC-3950-II were all able to inhibit effectively the binding of [125I-Tyr4]bombesin to the membranes of Hs746T cells. RC-3950-II showed a higher binding affinity for bombesin receptors than RC-3095 or RC-3110. Addition of the non-hydrolyzable guanine-nucleotide analog GTP [S] to the binding buffer caused a significant reduction in the amount of [125I-Tyr4]bombesin bound to the cells, indicating that the bombesin receptor is coupled to a G-protein. In cell cultures, bombesin significantly stimulated the growth of Hs746T cells in vitro as shown by an increase in the uptake of [3H]thymidine. Bombesin antagonist RC-3095 could effectively inhibit the bombesin-stimulated growth of Hs746T cells in cultures. These observations suggest that bombesin/GRP may act as growth factors through specific receptors present on the membranes of Hs746T cells. Bombesin/GRP antagonists appear to nullify the effects of bombesin/GRP and may be useful for the treatment of gastric cancers.

Antitumor effects of analogs of LH-RH and somatostatin: experimental and clinical studies.

Many clinical approaches for the treatment of hormone-sensitive tumors are being developed based on analogs of LH-RH and somatostatin. Inhibition of the pituitary-gonadal axis forms the basis for oncological applications of LH-RH agonists like [D-Trp6]-LH-RH and new LH-RH antagonists free of edematogenic effects such as [Ac-D-Nal(2)1-D-Phe(4Cl)2-D-Pal(3)3,D-Cit6,D-Ala10]-LH -RH (SB-75). Agonists and antagonists of LH-RH have been used in patients with prostate cancer and might be also beneficial for the treatment of breast cancer and ovarian, endometrial and pancreatic carcinomas. Some of the effects of LH-RH analogs can be due to direct action since LH-RH receptors have been found in these cancers. The use of sustained delivery systems based on microcapsules of PLG, makes the treatment more efficacious. Octapeptide analogs of somatostatin such as D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) and related analogs were designed specifically for antitumor activity. These somatostatin analogs, by virtue of having a wide spectrum of activities appear to inhibit various tumors through multiple mechanisms. Direct antiproliferative actions of somatostatin analogs appear to be mediated by specific receptors located on tumor cells. High affinity binding sites for RC-160 and related analogs have been found in human pancreatic, prostate, breast and ovarian cancers and brain tumors such as meningiomas. In vivo administration of analog RC-160 inhibits the growth of Dunning R-3327 prostate cancers in rats, MXT mammary tumors in mice and BOP-induced ductal pancreatic cancers in hamsters. Combination of microcapsules of RC-160 with [D-Trp6]-LH-RH results in synergistic potentiation of the inhibition of these cancers. Somatostatin analog RC-160 and LH-RH antagonist SB-75 are the object of further experimental studies and clinical trials aimed at the exploration of their inhibitory effects on the processes of malignant growth.

Pseudononapeptide bombesin antagonists containing C-terminal Trp or Tpi.

Seven new antagonists of bombesin (Bn)/gastrin-releasing peptide (GRP) containing C-terminal Trp or Tpi (2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-3-carboxylic acid) in a reduced peptide bond were synthesized by solid phase methods and evaluated biologically. The reduced bond in four [Leu13 psi(CH2NH)Trp14]Bn(6-14) analogs was formed by reductive alkylation at the dipeptide stage. In the case of three [Leu13 psi(CH2N)Tpi14]Bn(6-14) analogs, the Trp dipeptide with reduced bond was reacted with formaldehyde to form the corresponding Tpi derivative. These Tpi-containing analogs have a new reduced bond which is structurally more constrained. Leu13 psi(CH2N)Tpi14 analogs inhibit [125I][Tyr4]bombesin binding to Swiss 3T3 cells with IC50 values of 2-4 nM, compared to 5-10 nM for Leu13 psi(CH2NH)Trp14 analogs. Leu13 psi(CH2N)Tpi14 analogs are also more potent than Leu13 psi(CH2NH)Trp14 analogs in growth inhibition studies using Swiss 3T3 cells. The two best bombesin antagonists of this series, [D-Trp6,Leu13 psi(CH2N)Tpi14]Bn(6-14) (RC-3415) and [Tpi6,Leu13 psi(CH2N)Tpi14]Bn(6-14) (RC-3440), inhibited GRP-stimulated growth of Swiss 3T3 cells with IC50 values less than 1 nM. RC-3440 was also active in vivo, suppressing GRP(14-27)-stimulated serum gastrin secretion in rats. Bombesin/GRP antagonists, such as RC-3440, containing the new reduced bond (CH2N) reported herein are very potent.

High potency of a new bombesin antagonist (RC-3095) in inhibiting serum gastrin levels; comparison of different routes of administration.

This study was performed to evaluate the efficacy and duration of action of a new bombesin antagonist D-Tpi6,Leu13 psi (CH2NH)Leu14-bombesin (6-14) (RC-3095), given by different routes of administration, in suppressing gastrin releasing-peptide (GRP(14-27))-stimulated gastrin release in rats. First, we showed that GRP(14-27) itself was highly active when administered by different routes. GRP(14-27), given to rats at a dose of 25 micrograms/100 g b.w. significantly increased serum gastrin levels 3 and 6 min after intravenous and for more than 30 min after subcutaneous administration or pulmonary inhalation. RC-3095 was then injected subcutaneously, intravenously and also delivered by pulmonary inhalation at a dose of 10 micrograms/100 g b.w. in each case to seven male rats 2, 30, 60 or 120 min prior to i.v. administration of 5 micrograms GRP(14-27). RC-3095 administered 2 min prior to GRP(14-27) decreased the gastrin response to GRP(14-27), measured as area under the curve, by 81% in the intravenously injected group and 64% in the pulmonary inhalation group in the first 6 min. When GRP(14-27), was given 30 min after administration of RC-3095, the gastrin response was decreased by 52% in the subcutaneous group, 49% in the pulmonary inhalation group and 11% in the intravenous group during the first 6 min. RC-3095 delivered subcutaneously or by pulmonary inhalation 1 h before GRP(14-27) was also able to significantly inhibit gastrin release. Analysis of the data revealed that the bioavailability of RC-3095 given by the pulmonary inhalation route was about 69% of the s.c. route.(ABSTRACT TRUNCATED AT 250 WORDS)

Actions of novel bombesin receptor antagonists on pancreatic secretion in rats.

Recently synthesized highly specific and potent bombesin receptor antagonists permit study of the role of endogenous bombesin-like peptides in the physiological regulation of pancreatic secretion. We now tested the action of three novel pseudononapeptide bombesin/gastrin releasing peptide (GRP) antagonists (RC-3095, RC-3100 and RC-3120) on amylase release in vitro from isolated rat pancreatic acini and on protein secretion in vivo in chronic pancreatic fistula rats. In isolated pancreatic acini, all three bombesin receptor antagonists inhibited the amylase secretion induced by bombesin by shifting to the right the amylase response to bombesin without altering the maximal response. These antagonists alos reduced concentration dependently the near-maximal amylase response to bombesin, the concentration required for 50% reduction (IC50) being about 10(-7) M for RC-3095 and RC-3100 and 10(-6) M for RC-3120. None of the bombesin/GRP antagonists used affected the amylase response to CCK, pentagastrin or urecholine. In conscious rats with a chronic pancreatic fistula, all three bombesin antagonists shifted to the right the pancreatic protein response to graded doses of bombesin without changing the maximal response. These antagonists inhibited the protein response to constant background stimulation with bombesin in a dose-dependent manner, the ID50 being about 20 nmol/kg per h for RC-3095 and RC-3100 and about 160 nmol/kg per h for RC-3120. None of the antagonists significantly affected basal pancreatic secretion or secretion induced by sham-feeding, ordinary feeding or the diversion of pancreatic juice from the duodenum. These results indicate that exogenous bombesin is a potent direct stimulant of pancreatic enzyme secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of highly potent octapeptide analogs of somatostatin on growth hormone, insulin and glucagon release.

Biological activities of highly potent octapeptide analogs of somatostatin (SS), D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2 (RC-160) and D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Thr-NH2 (RC-121), were investigated in male rats. When analog RC-160 was administered to rats in which serum growth hormone (GH) levels were elevated by pentobarbital anesthesia, a dose-related inhibition of GH was obtained at dose range of 0.1 to 2.5 micrograms/kg. The time course of GH inhibition by RC-160, RC-121 and SS-14 was studied in rats treated with phenobarbital, morphine and chlorpromazine. Analogs RC-160 and RC-121 induced a prolonged inhibition of GH levels, in contrast to SS-14, whose effect was short-lived. The analogs suppressed the GH level for more than 2 hr, the peak inhibition being seen 30 to 60 min after the injection. The effects of analogs RC-160 and RC-121 on insulin secretion were observed in rats, in which insulin levels had been elevated by intravenous administration of glucose (500 mg/rat). Administration of RC-160 suppressed insulin secretion, dose-dependently, maximum but not complete inhibition being achieved at a dose of 100 micrograms/kg. In this model, RC-160 and RC-121, in doses of 30 micrograms/kg, induced a similar inhibition of insulin release as 200 micrograms/kg of SS-14, whose action of SS-14 was transient. The effect of analog RC-160 on glucagon release was studied in rats with glucagon levels elevated by hypoglycemia. RC-160 suppressed the secretion of glucagon, the inhibition being dose-dependent in the range of 0.1 to 2 micrograms/kg. Doses of 2 and 10 micrograms/kg of this analog completely suppressed the hypoglycemia-induced glucagon release. These results indicate that analogs RC-160 and RC-121 possess prolonged and enhanced biological activities, the former analog showing a high selectivity in inhibiting GH and glucagon release in vivo as compared with that of insulin secretion.

Inhibitory effect of bombesin/gastrin-releasing peptide (GRP) antagonists RC-3950-II and RC-3095 on MCF-7 MIII human breast cancer xenografts in nude mice.

Bombesin/gastrin-releasing peptide (GRP) may be involved in the growth of human breast cancers. Nude mice bearing xenografts of MCF-7 MIII human breast cancer cell line were treated for 7 weeks with bombesin/GRP antagonists RC-3950-II and RC-3095. RC-3950-II, administered sc twice daily at a dose of 10 micrograms, produced significant inhibitory effects on tumor growth after 2 weeks of administration. RC-3095 acetate (D 22213), injected sc twice daily at the same dose of 10 micrograms, suppressed tumor growth after 4 weeks. Both RC-3950-II and RC-3095 significantly decreased the final tumor volume and tumor weights. RC-3950-II appeared to be somewhat more efficacious than RC-3095 in inhibiting the growth of MCF-7 MIII breast cancers. Chronic treatment with either bombesin/GRP antagonist caused down-regulation of receptors for epidermal growth factor (EGF) in tumor cell membranes, which might be related to inhibition of tumor growth. These findings suggest that bombesin/GRP antagonists should be considered for a new endocrine therapy of breast cancer.

Antagonism of receptors for gastrin, cholecystokinin and GRP/bombesin in postprandial stimulation of exocrine pancreas in dogs.

Postprandial pancreatic secretion results from the interaction of neural and hormonal factors such as cholecystokinin (CCK), gastrin and gastrin releasing peptide (GRP), but their contribution to the net secretion is not established. Recent description of highly specific and potent hormonal receptor antagonists allows the determination of the physiological role of CCK, gastrin and GRP. In six dogs with chronic pancreatic fistulas, the blockade of CCK receptors by L-364, 718, gastrin receptors by L-365, 260 or GRP/bombesin receptors by nonapeptide RC-3095 failed to affect basal or sham-feeding induced pancreatic secretion indicating that none of these hormonal peptides plays a major role in this secretion. In contrast, the pancreatic response to ordinary feeding (which includes cephalic, gastric and intestinal phases), that was accompanied by a significant increment in plasma CCK and gastrin levels, was strongly inhibited (by over 50%) by L-364, 718 and slightly (by 20-30%) by L-365, 260 but not by RC-3095. Each antagonist was given at a dose that eliminated the secretory response to CCK, gastrin or GRP, respectively. We conclude that specific receptor antagonists are useful tools in assessing the physiological role of gut hormones in the control of pancreatic secretion and that none of the peptides tested appears to be involved in the cephalic phase. However, CCK plays a major role in the postprandial stimulation of pancreatic secretion.

The effects of antagonists of receptors for gastrin, cholecystokinin and bombesin on growth of gastroduodenal mucosa and pancreas.

The effects of gastrin, cholecystokinin (CCK) and bombesin on the DNA synthesis, as a biochemical indicator of trophic action in the gastroduodenal mucosa and the pancreas have been examined in rats fasted for 48 h and in rats refed for 16 h with or without administration of specific receptor antagonists for bombesin, gastrin and CCK. Bombesin and gastrin administered three times daily for 48 h in fasted rats significantly increased the rate of DNA synthesis as measured by the incorporation of [3H] thymidine into DNA in each tissue tested. CCK significantly increased DNA synthesis in the duodenal mucosa and pancreatic tissue, but not in the gastric mucosa. The stimulation of DNA synthesis induced by bombesin in the gastroduodenal mucosa and pancreas was abolished by bombesin/GRP receptor antagonist, RC-3095. RC-3095 did not affect DNA synthesis stimulated by gastrin and CCK in these tissues. L-365,260, a receptor antagonist for gastrin suppressed the DNA synthesis induced by gastrin but not by CCK or bombesin in the gastrointestinal mucosa and pancreas. L-364,718 a specific antagonist for CCK receptors was effective only against CCK stimulated duodenal mucosa and pancreatic growth. Refeeding of 48 h fasting rats strongly enhanced the DNA synthesis in all tissues tested, and this effect was significantly reduced in the gastroduodenal mucosa by blocking only gastrin receptors (with L-365,260) and that in the duodenal mucosa and the pancreas by antagonizing of CCK receptors (with L-364,718). Antagonism of bombesin receptors (with RC-3095) did not significantly affect the stimulation of DNA synthesis induced by refeeding in all tissues tested. This study indicates that the stimulation of DNA synthesis can be achieved by exogenous gastrin, CCK and bombesin acting through separate receptor but that only gastrin and CCK play the major role in the postprandial stimulation of the growth of gastroduodenal mucosa and pancreatic tissue.

The effect of antagonist of receptors for gastrin, cholecystokinin and bombesin on growth of gastroduodenal mucosa and pancreas.

The effects of gastrin, cholecystokinin (CCK) and bombesin on the DNA synthesis, as a biochemical indicator of trophic action in the gastroduodenal mucosa and the pancreas, have been examined in rats fasted for 48 h and in rats refed for 16 h with or without administration of specific receptor antagonists for bombesin, gastrin and CCK. Bombesin and gastrin administered three times daily for 48 h in fasted rats significantly increased the rate of DNA synthesis as measured by the incorporation of [3H] thymidine into DNA in each tissue tested. CCK significantly increased DNA synthesis in the duodenal mucosa and pancreatic tissue, but not in the gastric mucosa. The stimulation of DNA synthesis induced by bombesin in the gastroduodenal mucosa and pancreas was abolished by bombesin/GRP receptor antagonist, RC-3095. RC-3095 did not affect DNA synthesis stimulated by gastrin and CCK in these tissues. L-365,260, a receptor antagonist for gastrin suppressed the DNA synthesis induced by gastrin but not by CCK or bombesin in the gastrointestinal mucosa and pancreas. L-364,718, a specific antagonist for CCK receptors was effective only against CCK stimulated duodenal mucosa and pancreatic growth. Refeeding of 48 h fasting rats strongly enhanced the DNA synthesis in all tissues tested, and this effect was significantly reduced in the gastroduodenal mucosa by blocking only gastrin receptors (with L-365, 260) and that in the duodenal mucosa and the pancreas by antagonizing of CCK receptors (with L-364,718). Antagonism of bombesin receptors (with RC-3095) did not significantly affect the stimulation of DNA synthesis induced by refeeding in all tissues tested. This study indicates that the stimulation of DNA synthesis can be achieved by exogenous gastrin, CCK and bombesin acting through separate receptors, but that only gastrin and CCK play the major role in the postprandial stimulation of the growth of gastroduodenal mucosa and pancreatic tissue.

[Reoperation of postoperative rebleeding in patients with portal hypertension].

Since 1970, reoperation was performed on 84 cases with postoperative rebleeding gastroesophageal varices. The operative mortality was 15.5%. Of the 71 patients discharged from the hospital 67 were followed up. The five year survival rate after the operation was 66.1%. Seven of 43 cases treated by portoazygos disconnection died of bleeding varices after the surgery. Among the 32 cases undergoing portal systemic shunt, one died of rebleeding. Shunt operation plus portoazygos disconnection was performed on 5 cases without postoperative rebleeding death. Three of four patients treated by incomplete portoazygos disconnection died of postoperative rebleeding. Our results showed that shunt operation alone or added with portoazygos disconnection have the advantage over portoazygos disconnection in preventing postoperative bleeding, and should be the procedure of choice in treating rebleeding patients.

Antagonists of bombesin/gastrin-releasing peptide decrease the expression of angiogenic and anti-apoptotic factors in human glioblastoma.

We have investigated the antitumor effects and the mechanism of action of antagonists of bombesin/gastrin-releasing peptide (GRP), RC-3940-II and RC-3940-Et, on the growth of U-118MG human malignant glioma xenografted into nude mice. Tumors volume was measured weekly, and after 6 weeks of treatment with GRP antagonists the tumors were analyzed by Western blot assays for the expression of vascular endothelial growth factor (VEGF), protein kinase C (PKC)-alpha, the anti-apoptotic protein Bcl-2 and the pro-apoptotic protein Bax. A radioreceptor assay was used to characterize the receptors for bombesin/GRP. Specific high-affinity receptors for bombesin were found in U-118MG tumors, and their growth was reduced by 52.5% by RC-3940-II and 72.6% by RC-3940-Et (both p<0.01). The tumor doubling time was prolonged by 4.6 and 12 days after treatment with RC-3940-II and RC-3940-Et, respectively, compared to controls (p<0.05). Both antagonists caused a significant (p<0.05) decrease of about 28% in the levels of VEGF protein and a reduction of approximately 35% in the expression of PKCalpha. The relative ratio of Bcl-2:Bax was also diminished by around 70% by both analogs, indicating a net apoptotic gain and the efficacy of treatment. Our results suggest that bombesin/GRP antagonists, RC-3940-II and RC-3940-Et, could be of value for the treatment of human glioblastomas.

Potent bombesin antagonists with C-terminal Leu-psi(CH2-N)-Tac-NH2 or its derivatives.

Various pseudononapeptide bombesin (BN)-(6-14) antagonists with a reduced peptide bond (CH2-NH) between positions 13 and 14 can suppress the mitogenic activity of BN or gastrin-releasing peptide in 3T3 fibroblast cells and small cell lung carcinoma. In the search for more potent BN antagonists, 10 modified nonapeptide BN antagonists containing N-terminal D-Phe, D-Cpa, and D- or L-Tpi and C-terminal Leu-psi(CH2-N)-Tac-NH2, Leu-psi(CH2-N)-MeTac-NH2, or Leu-psi(CH2-N)-Me2Tac-NH2 have been synthesized by incubating [13 psi 14,CH2-NH,Cys14]BN-(6-14) or [13 psi 14-CH2-NH,Pen14]BN-(6-14) with formaldehyde or acetaldehyde (Cpa = 4-chlorophenylalanine, Tac = thiazolidine-4-carboxylic acid, Tpi = 2,3,4,9-tetrahydro-1H- pyrido[3,4-b]indol-3-carboxylic acid, and Pen = penicillamine). The biological activities of these compounds were then evaluated. [D-Phe6,13 psi 14,CH2-N,Tac14]BN-(6-14) (RC-3950-II) and [D-Phe6,13 psi 14,CH2-N,Me2Tac14]BN-(6-14) (RC-3985-II) exhibited greater potency in inhibition of 125I-labeled [Tyr4]BN binding to Swiss 3T3 cells than their parent compounds [D-Phe6,13 psi 14,CH2-NH,Cys14]BN-(6-14) (RC-3950-I) and [D-Phe6,13 psi 14,CH2-NH,Pen14]BN-(6-14) (RC-3985-I). The order of binding affinities of these compounds was as follows: [13 psi 14,CH2-N,Tac14]BN-(6-14) > [13 psi 14,CH2-N,Me2Tac14]BN-(6-14) > [13 psi 14,CH2-N,MeTac14]BN-(6-14). In most cases, the analogs with C-terminal Leu-psi(CH2-N)-Tac-NH2 were also more potent growth inhibitors of 3T3 cells than compounds containing C-terminal Leu-psi(CH2-N)-Me2Tac-NH2 or Leu-psi(CH2-N)-MeTac-NH2. The best BN antagonists of this series, RC-3950-II and [D-Cpa6,13 psi 14,CH2-N,Tac14]BN- (6-14) (RC-3925-II), inhibited gastrin-releasing peptide-stimulated growth of Swiss 3T3 cells with IC50 values of 1 nM and 6 nM, respectively. Since antagonists of this class inhibit growth of various tumors in animal cancer models, some of them may have clinical applications.