Long-term effects of proglumide on resection of cardiac adenocarcinoma

AIM:Patients with advanced stage cardiac adenocarcinoma have a very poor prognosis. Surgery is the first choice of treatment for this kind of patients. Peptide hormone gastrin is a recognized growth factor for gastric cancer, and gastrin receptor antagonist proglumide can block the effects of gastrin. The aim of this study was to investigate the actions of proglumide as an adjuvant treatment to improve the postoperative long-term survival rate of patients with cardiac adenocarcinoma. METHODS: We performed a randomized, controlled study of gastrin receptor antagonist proglumide in 301 patients with cardiac adenocarcinoma after proximal subtotal gastrectomy. The oral dose of 0.4 g proglumide thrice daily preprandially was maintained for more than 5 years in 153 cases (proglumide treatment group). In the control group, 148 patients underwent operation only. In clinicopathologic features, there was no significant difference between the two groups (P>0.05). All patients were followed up during their lifetime, and the survival rates were analyzed combined with clinicopathologic factors by SPSS 11.5 statistical software. RESULTS: The 1,3,5 and 10-year survival rate of the patients was 88.4%, 48.8%, 22.6% and 13.4%, respectively. The 1,3,5 and 10-year survival rate of the proglumide treatment group was 90.2%, 49.7%, 26.8% and 17.6% compared to 86.5%, 48.0%, 18.2% and 8.9% of the control group. There was a significant difference between the two groups (P= 0.0460). The patients in proglumide treatment group had no obvious side effects after administration of the drug, and no definite hepatic and renal function damage was found. According to single factor log-rank analysis, the long-term survival rate was correlated with the primary tumor position (P= 0.0205), length of the tumor (P= 0.0000), property of the operation (P= 0.0000), histopathologic grading (P = 0.0003), infiltrating degree of the tumor (/>= 0.0000), influence of lymph node metastasis (P = 0.0000), clinicopathologic staging (P= 0.0000) and administration of proglumide (P = 0.0460). Cox regression analysis demonstrated the infiltrating degree of tumor (P= 0.000), influence of lymph node metastasis (P= 0.039) and the clinicopathologic staging (P = 0.003) were independent prognostic factors. Administration of proglumide (P= 0.081), length of the tumor (P = 0.304), radical status of the resection (P= 0.224) and histopathologic types (P= 0.072) were not the independent prognostic factors. CONCLUSION: Proglumide is convenient to use with no obvious toxic side effects, and prolonged postoperative administration of proglumide as a postoperative adjuvant treatment can increase the survival rate of patients after resection of cardiac adenocarcinoma. Proglumide may provide a new effective approach of endocrinotherapy for patients with gastric cardiac cancer.

Regulatory effect and mechanism of gastrin and its antagonists on colorectal carcinoma

AIM:To explore the effect and mechanism of gastrin and its antagonists prog lumide and somatostatin on colorectal carcinoma and their clinical significance.METHODS:A model of transplanted human colonic carcinoma was established from SW480 cell line in gymnomouse body.The volume and weight of transplanted carcinoma was observed under the effect of pentagatrin (PG), proglumide (PGL) and octapeptide somotostatin (SMS201-995, SMS). The cAMP content of carcinoma cell was determined by radioimmunoassay and the DNA, protein content and cell cycle were determined by flow-cytometry. The amount of viable cells was determined by MTT colorimetric analysis,IP(3) content was determined by radioimmunoassay, Ca(2+) concentration in cell by fluorometry and PKC activity by isotopic enzymolysis. The expression of gastrin, c-myc, c-fos and rasP21 in 48 cases of colorectal carcinoma tissue was detected by the immuno-cytochemistry SP method. Argyrophilia nucleolar organizer regions was determined with argyrophilia stain.RESULTS:The volume,weight, cAMP, DNA and protein content in carcinoma cell, cell amount and proliferation index of S and G(2)M phase in PG group were all significantly higher than those of control group. When PG was at the concentration of 25mg/L, the amount of viable cells, IP(3) content and Ca(2+) concentration in cell and membrane PKC activity in PG group were significantly higher than those in control group; when PGL was at a concentration of 32mg/L, they dropped to the lowest level in PG (25mg/L)+PGL group, but without significant difference from the control group. The positive expression rate of gastrin, c-myc, c-fos and rasP21 in carcinoma tissue was 39.6%, 54.2%, 47.9% and 54.2% respectively and significantly higher than that in mucosa 3cm and 6cm adjacent to carcinoma tissue and normal colorectal mucosa. The positive expression rate of gastrin of highly differentiated adenocarcinoma group was significantly higher than that of poorly differentiated and mucinous adenocar-cinoma groups. The AgNORs count of carcinoma tissue was significantly higher than that in mucosa 3cm and 6cm adjacent to carcinoma tissue and normal colorectal mucosa; and the positive expression of c-myc and c-fos and the AgNORs count in gastrin-positive group was significantly higher than those in gastrin negative group.CONCLUSION:Pentagastrin has a promoting effect on the growth of transplanted human colonic carcinoma from SW480 cell line. PGL has no obvious effect on the growth of human colonic carcinoma SW480 cell line, but could inhibit the growth promoting effect of PG on transplanted carcinoma. Somatostatin can not only inhibit the growth of transplanted human colonic carcinoma from SW480 cell line directly but also depress the growth-promoting effect of gastrin on the transplanted carcinoma. Some colorectal carcinoma cells can produce and secrete gastrin through autocrine, highly differentiated adenocarcinoma express the highest level gastrin.Endogenous gastrin can stimulate the cell division and proliferation of carcinoma cell and promote the growth of colorectal carcinoma regulating the expression of oncogene c-myc, c-fos. Our study has provided experimental basis for the adjuvant treatment using gastrin antagonist such as PGL, somatostatin of patients with colorectal carcinoma.

Role of p38 Signaling Pathway in Pentagastrin-Regulated Cell Proliferation of Colorectal Carcinoma Cell Line HT-29

Objective: To investigate the effects and mechanisms of p38 signaling pathway in pentagastrin-regulated cell proliferation of colorectal carcinoma cell line HT-29. Methods: HT-29 cell line of colorectal carcinoma was in vitro incubated and divided into the control group, pentagastrin group, proglumide group, and pentagastrin + proglumide group. MTT reduction assay was performed to detect the proliferation status of HT-29 cell line and determine the optimal dosage of pentagastrin and proglumide. Annexin V-fluorescein isothiocyanate flow cytometry was used to detect the proliferation index (PI) and apoptosis rate (AR) of HT-29 cells. Reverse transcriptase polymerase chain reaction was performed to detect the mRNA expression of the pentagastrin receptor/cholecystokinin-B receptor (CCK-BR) and p38. The protein and phosphorylation levels of p38 were estimated by western blotting. Results: RT-PCR detection showed that CCK-BR mRNA was expressed in the HT-29 cell line. Pentagatrin improved HT-29 cell proliferation in dosage of 6.25 - 100 mg/L, and the optimal dosage of pentagastrin was 25.0 mg/L. Proglumide had no significant effect on the proliferation of HT-29 cells, but significantly inhibited the proliferation of HT-29 cells stimulated by pentagastrin when the dosage of proglumide was 8.0 - 128.0 mg/L, and the optimal dosage was 32.0 mg/L. The AR in the pentagastrin group was significantly lower than that in the control group and in the pentagastrin + proglumide group. The PI in the pentagastrin group was significantly higher than that in the control group and in the pentagastrin + proglumide group. P38 phosphorylation level in the pentagastrin group was significantly lower than that in the control group, and in the pentagastrin + proglumide group. There were no significant differences in the mRNA and protein expression of p38 in the control, pentagastrin, proglumide and pentagastrin + proglumide groups. Conclusion: Pentagastrin can improve proliferation of the CRC cell line HT-29 and inhibit apoptosis via the p38 signal transduction pathway. This mechanism may be associated with suppressed p38 protein phosphorylation level due to inhibition of proglumide, a gastrin receptor antagonist.

CENTRAL CHOLECYSTOKININ OCTAPEPTIDE ACCELERATING THE RECOVERY OF THE RAT FROM HEMORRHAGIC SHOCK

There have been data showing that central cholecystokinin oetapeptide (CCK-8) could antagonize the analgesia induced by exogenous and endogenoust opioid peptides. Recently, we found that the hypotension produced by opioid peptides could also be reversed by central administration of CCK-8 (Mei Lin et al., unpublished result). The above-mentioned results either in physiology or in pharmacology suggested that CCK-8 appeared to have a potent antagonistic effect against opioid peptides and may be the endogenous anti-opioid substance.

The Antagonistic Effect of Cholecystokinin Octapeptide (CCK-8) on Opioid Effects in Cardiovascular Activities Was Mediated by CCK-B Receptor

Previous studies have shown that CCK-8 has distinct antiopioid effect in the central sites related with pain control and blood pressure control. The aim of this study was to explore the receptor mechanism by which CCK-8 antagonized the depressor effect of u-and k-opioid agonists, and to observe whether CCK-8 could antagonize the depressor effect induced by muscimol, a nonopioid substance. The results showed that (ⅰ) The antagonistic effect of CCK-8 on opioid-induced hypotension could be blocked by intrathecal (i.t.) administration of CCK-B antagonist L-365, 260 at nanogram doses, or by CCK-A antagonist devazepide at doses 20—40 times higher than L-365, 260, indicating that it was the CCK-B receptor which mediates the antiopioid effect. (ⅱ) The depressor effect induced by intrathecal muscimol, a GABA agonist, was blocked neither by naloxone nor by CCK-8, supporting the notion that CCK-8 is an endogenous opioid antagonist rather thana universal anti-hypotension agent.