sirolimus and Stomach-Neoplasms

Gastric cancer remains one of the most common types of cancer worldwide, and most patients present withadvanced disease. Sixty percent of these patients eventually relapse after curative surgical resection, and combinationchemotherapy regimens only provide limited survival benefits. Mammalian target of rapamycin (mTOR) is a new targetof cancer therapies. Preclinical data suggest that the suppression of the mTOR pathway inhibits the progression of gastriccancer in vitro and in animal models. In clinical trials, the mTOR inhibitor, everolimus, was well tolerated in phase I/IIstudies on patients with metastatic gastric cancer. The efficacy of everolimus was promising in a phase II clinical trial, butin a recently published phase III clinical trial everolimus monotherapy do not significantly improve the overall survival ofpatients with advanced gastric cancer who had been previously treated with one or two lines of systemic chemotherapy.Phosphoinositide 3-kinase/mTOR dual inhibitors have not yet entered early-stage clinical trials in patients with advanced gastric cancer. Further studies are needed to establish the role of mTOR inhibitors for the treatment of gastric cancer.

Topics: Animals; Antineoplastic Agents; Clinical Trials as Topic; Everolimus; Humans; Neoplasm Metastasis; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases

The poor long-term outcomes associated with current chemotherapy treatment of patients with advanced gastric cancer suggest a need for novel targeted agents that may confer a better survival benefit. Evidence of mammalian target of rapamycin (mTOR) activation has been demonstrated in patient-derived gastric cancer cells and tumors. This review explores the relevance of the mTOR pathway to gastric cancer pathogenesis and its potential as a therapeutic target in patients with gastric cancer as well as presenting the first available clinical data on mTOR inhibitors in this disease setting. Preclinical data suggest that suppression of the mTOR pathway inhibited the proliferation of gastric cancer cells and delayed tumor progression in in vitro and animal models. In the clinical setting, the mTOR inhibitor everolimus has been active and well tolerated in phase I/II studies of patients with chemotherapy-refractory metastatic gastric cancer. Based on these promising results, everolimus currently is being investigated as a monotherapy or in combination with chemotherapeutic agents in ongoing phase II/III clinical studies.

Topics: Animals; Antineoplastic Agents; Everolimus; Humans; Molecular Targeted Therapy; Protein Kinase Inhibitors; Signal Transduction; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases

Despite recent improvements in surgical techniques and chemotherapy, advanced cancers of the stomach and gastroesophageal junction (GEJ) continue to have poor clinical outcomes. However, molecules intimately related to cancer cell proliferation, invasion, and metastasis have been studied as candidates for molecular targeted agents. Target molecules, such as the epidermal growth factor receptor, vascular endothelial growth factor receptor, and P13k/Akt/mTor pathway, as well as the insulin-like growth factor receptor, c-Met pathways, fibroblast growth factor receptor, and other pathways are considered to be promising candidates for molecular targeted therapy for gastric and GEJ cancer. In this review we focus on the recent developments in targeting relevant pathways in these types of cancer.

Topics: Antibodies, Monoclonal; Antineoplastic Agents; ErbB Receptors; Esophageal Neoplasms; Esophagogastric Junction; Humans; Insulin-Like Growth Factor I; Molecular Targeted Therapy; Proto-Oncogene Proteins c-met; Receptor Protein-Tyrosine Kinases; Sirolimus; Stomach Neoplasms; Vascular Endothelial Growth Factor A

Neuroendocrine tumors (NETs) represent a relatively rare form of neoplasias for which, in advanced unresectable stages, palliative treatment options remain limited largely to the use of somatostatin analogues or chemotherapy. Several newer targeted therapeutic options, alone or in combination with somatostatin analogues, are currently undergoing clinical evaluation for the treatment of NETs. This article reports the compassionate use of everolimus in combination with long-acting octreotide, in a 58-year old Italian female patient with a well-differentiated neuroendocrine gastric tumor who, since October 2004, has failed multiple previous therapies. Starting in October 2008, the patient has received intramuscular octreotide LAR 30 mg every 28 days plus everolimus 10 mg/day. The patient has reported benefits of symptoms (reduction of pain severity), objective response [improvement of liver function (reductions in LDH, ALP and total bilirubin) and chromogranin A], and radiological response (reduction in target lesions on CT). The patient has experienced an improved quality of life, increased life expectancy, and remains on this well-tolerated treatment regimen.

Topics: Antineoplastic Agents; Compassionate Use Trials; Drug Therapy, Combination; Everolimus; Female; Humans; Immunosuppressive Agents; Middle Aged; Neuroendocrine Tumors; Octreotide; Sirolimus; Stomach Neoplasms

Our study was designed to evaluate the efficacy and safety of everolimus in patients with pre-treated metastatic gastric and esophagus cancers in a US-based population focusing on biomarker correlation.. Patients with advanced upper GI adenocarcinomas who progressed after 1-2 prior regimens received everolimus 10 mg PO daily. The primary endpoint was disease control rate (DCR). Secondary endpoints included progression-free survival (PFS), toxicity, overall survival (OS) and biomarker correlatives of the mTOR pathway. Target accrual was 50 patients based on one-sided type I error of 10 % and power of 90 %.. Forty-five patients were evaluable, 21 gastric, 11 esophagus and 13 from the GEJ. The median age was 64 (range 38-73); all patients had an ECOG of 0 or 1; and 18 patients (40 %) had only 1 prior regimen. The most common grade 3-4 adverse events included fatigue (24 %) and thrombocytopenia (22 %). We observed 1 partial response with 39 % of evaluable patients having stable disease. Median OS was 3.4 months (95 % CI 2.7-5.6 months), and PFS was 1.8 months (95 % CI 1.7-2.2 months). There was a strong correlation between ≥2 + IHC staining for p-S6 in tumor samples with better PFS (p < 0.0001) and DCR (p = 0.0001).. Our clinical outcomes were inferior to the Asian studies, which may be explained by disease heterogeneity. However, there was a similar strong correlation between clinical benefit and tumor high pS6. Testing this biomarker in patient samples from the randomized phase III Granite trial may lead to a positive predictive marker.

Topics: Adenocarcinoma; Adult; Aged; Antineoplastic Agents; Biomarkers, Tumor; Esophageal Neoplasms; Esophagogastric Junction; Everolimus; Female; Humans; Male; Middle Aged; Neoplasm Metastasis; Sirolimus; Stomach Neoplasms

Preclinical and clinical studies suggest synergistic activity between somatostatin analogues and mammalian target of rapamycin inhibitors. The activity and safety of everolimus was assessed in combination with octreotide long-acting repeatable (LAR) in patients with neuroendocrine tumors (NETs) of gastroenteropancreatic and lung origin.. This was a phase 2, multicenter trial using a Simon's 2-stage minimax design. Treatment-naive patients with advanced well-differentiated NETs of gastroenteropancreatic tract and lung origin received everolimus 10 mg daily, in combination with octreotide LAR 30 mg every 28 days. The primary endpoint was objective response rate (ORR).. A total of 50 patients (median age, 60.5 years) were enrolled. Primary tumor sites were: pancreas (14 patients), lung (11 patients), ileum (9 patients), jejunum and duodenum (2 patients), and unknown (14 patients). Thirteen patients (26%) had carcinoid syndrome. Treatment-related adverse events (AEs) were mostly grade 1 or 2; the only grade 4 AE was mucositis in 1 patient, whereas grade 3 AEs included skin rash in 1 case (2%), stomatitis in 4 cases (8%), and diarrhea in 11 cases (22%). The ORR was 18%; 2% of patients had a complete response (CR), 16% a partial response (PR) and 74% achieved stable disease (SD). All CRs and all PRs as well as 92% of SDs had a duration ≥ 6 months. The clinical benefit (CR+PR+SD) was 92%. At a median follow-up of 277 days, median time to progression and overall survival were not reached.. The everolimus-octreotide LAR combination was active and well tolerated in these previously treated patients with advanced NETs, suggesting a possible role as first-line treatment in patients with NET.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Everolimus; Female; Humans; Intestinal Neoplasms; Lung Neoplasms; Male; Middle Aged; Neuroendocrine Tumors; Octreotide; Pancreatic Neoplasms; Sirolimus; Stomach Neoplasms

This phase II trial investigates the efficacy and safety of low-dose everolimus in combination with cisplatin-fluorouracil chemotherapy in patients with advanced gastric cancer.. Eligible patients with chemotherapy-naïve advanced gastric cancer received low-dose everolimus (10 mg p.o. on days 1, 8 and 15) plus cisplatin and a weekly 24-hour infusion of high-dose 5-fluorouracil and leucovorin (HDFL) chemotherapy (cisplatin 35 mg/m(2) intravenous infusion for 24 h on days 1 and 8, 5-fluorouracil 2,000 mg/m(2) and leucovorin 300 mg/m(2) intravenous infusion for 24 h on days 1, 8 and 15) every 28 days. The primary endpoint was objective response rate (ORR) according to the Response Evaluation Criteria in Solid Tumors version 1.0.. Forty patients (19 men; 21 women; median age, 54.1 years; range, 33.7-73.3 years) received a median of 6 (range, 1-30; 95% CI, 4.9-8.0) cycles of study treatment. The ORR was 52.5% (21 confirmed partial response). The median progression-free survival and overall survival were 6.9 (95% CI, 4.9-8.4) and 10.5 (95% CI, 8.6-12.3) months, respectively. Most adverse events were mild.. Adding low-dose everolimus to cisplatin-HDFL chemotherapy failed to increase the ORR as in a preplanned statistical assumption but may prolong progression-free survival in treatment-naïve advanced gastric cancer patients.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Cisplatin; Disease-Free Survival; Dose-Response Relationship, Drug; Drug Administration Schedule; Everolimus; Female; Fluorouracil; Humans; Infusions, Intravenous; Leucovorin; Male; Middle Aged; Pilot Projects; Sirolimus; Stomach Neoplasms; Taiwan; Treatment Outcome

This study aimed at determining the recommended dose of the mammalian target of rapamycin inhibitor everolimus in combination with mitomycin C (MMC) in patients with previously treated metastatic esophagogastric cancer. In this phase I trial, patients received escalated doses of oral everolimus (5, 7.5, and 10 mg/day) in combination with intravenous MMC 5 mg/m² every 3 weeks. Endpoints were the dose-limiting toxicity (DLT), safety, and response rates. Tumor tissues were tested for HER2-status and mutations in the PTEN, PIK3CA, AKT1, CTNNB1, and E-cadherin type 1 genes. Sixteen patients (12 male, four female) with gastric/gastroesophageal junction cancer were included. All patients were previously treated with a platinum-based chemotherapy. Treatment cohorts were: 5 mg/day, three patients; 7.5 mg/day, three patients; and 10 mg/day, 10 patients. No DLTs occurred during dose escalation. Most frequent grade 3 toxicities were leukopenia (18.8%) and neutropenia (18.8%). All other grade 3 toxicities were below 10%. No grade 4 toxicities occurred. Three (18.8%) patients experienced partial responses and four patients had stable disease (SD). Antitumor activity according to Response Evaluation Criteria In Solid Tumors (RECIST)-criteria was highest in the 10 mg/day cohort. No associations between HER2-status or detected mutations and response were observed. The recommended dose of everolimus combined with MMC is 10 mg/day. Encouraging signs of antitumor activity were seen (http://www.ClinicalTrials.gov;. NCT01042782).

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Dose-Response Relationship, Drug; Esophageal Neoplasms; Everolimus; Female; Humans; Male; Middle Aged; Mitomycin; Sirolimus; Stomach Neoplasms; Survival Analysis

The aim of this study was to assess the efficacy and safety of combination regimen of capecitabine plus everolimus in patients with refractory gastric cancer who have failed to at least two cytotoxic regimens.. Patients received capecitabine 650 mg/m(2) twice daily (D1-14) and everolimus 5 mg twice daily (D1-21) every 3 weeks until disease progression or unacceptable toxicity. The primary endpoint of the study was overall response (partial or complete response) and the secondary endpoints were progression-free survival (time between registration and disease progression or death) and overall survival. Pharmacokinetic analysis was also performed. Patients who have failed to at least two cytotoxic regimens were enrolled.. Between March 2010 and June 2012, 47 patients were enrolled. 33 patients (70.2%) had received more than three previous regimens prior to enrolment. Among 43 evaluable patients for treatment response, 5 patients achieved confirmed partial response and 18 patients showed stable disease, resulting in an overall response rate (ORR) of 10.6% (95% C.I.: 1.8-19.4%) and disease control rate of 48.9% (95% C.I.:34.6-63.2%). At a median follow-up of 106 weeks (range, 21-141 weeks), the median progression-free survival and overall survival were 11.0 weeks (95% C.I.: 5.7-16.3 weeks) and 21.0 weeks (95% C.I.: 14.3-27.7 weeks), respectively. Grade 3 nausea, diarrhea and stomatitis occurred in two, three and three patients, respectively. Elevated liver enzyme was observed in 21 patients and no patient had pulmonary fibrosis.. The combination of capecitabine 650 mg/m(2) twice daily and everolimus 5 mg twice daily was found to be effective in a small subset of GC patients who were heavily pre-treated.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Capecitabine; Deoxycytidine; Drug Resistance, Neoplasm; Everolimus; Female; Fluorouracil; Humans; Male; Middle Aged; Sirolimus; Stomach Neoplasms; Young Adult

The oral mammalian target of rapamycin inhibitor everolimus demonstrated promising efficacy in a phase II study of pretreated advanced gastric cancer. This international, double-blind, phase III study compared everolimus efficacy and safety with that of best supportive care (BSC) in previously treated advanced gastric cancer.. Patients with advanced gastric cancer that progressed after one or two lines of systemic chemotherapy were randomly assigned to everolimus 10 mg/d (assignment schedule: 2:1) or matching placebo, both given with BSC. Randomization was stratified by previous chemotherapy lines (one v two) and region (Asia v rest of the world [ROW]). Treatment continued until disease progression or intolerable toxicity. Primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), overall response rate, and safety.. Six hundred fifty-six patients (median age, 62.0 years; 73.6% male) were enrolled. Median OS was 5.4 months with everolimus and 4.3 months with placebo (hazard ratio, 0.90; 95% CI, 0.75 to 1.08; P = .124). Median PFS was 1.7 months and 1.4 months in the everolimus and placebo arms, respectively (hazard ratio, 0.66; 95% CI, 0.56 to 0.78). Common grade 3/4 adverse events included anemia, decreased appetite, and fatigue. The safety profile was similar in patients enrolled in Asia versus ROW.. Compared with BSC, everolimus did not significantly improve overall survival for advanced gastric cancer that progressed after one or two lines of previous systemic chemotherapy. The safety profile observed for everolimus was consistent with that observed for everolimus in other cancers.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Disease-Free Survival; Double-Blind Method; Everolimus; Female; Humans; Immunosuppressive Agents; Kaplan-Meier Estimate; Male; Middle Aged; Neoplasm Recurrence, Local; Proportional Hazards Models; Sirolimus; Stomach Neoplasms; Young Adult

To evaluate the activity and safety of everolimus and identify potential biomarkers for efficacy of everolimus in patients with advanced gastric cancer (AGC), who failed both fluoropyrimidine and platinum.. Fifty-four patients received everolimus (10 mg day(-1)). The primary objective was to determine the 4-month progression-free survival (PFS) rate, assumed to be 30%. We additionally investigated the potential biomarkers for everolimus as an exploratory endpoint in those who underwent tumour biopsies.. Two patients (3.7%) achieved partial response and the disease control rate (DCR) was 38.9%. At a median follow-up duration of 8.7 months, the 4-month PFS rate was 18.4%, not fulfilling the primary hypothesis, with a median PFS of 1.7 months and a median overall survival of 8.3 months. The high expression of pS6(Ser240/4) at baseline was significantly associated with higher DCR (P=0.043) and prolonged PFS (P=0.001). Grade 1/2 asthenia (96.3%) recorded as the leading toxicity and hyperglycaemia (20.4%) was the most common non-hematological grade 3/4 toxicity. Three patients experienced grade 3/4 pneumonitis. Notably, two experienced treatment-related deaths.. Everolimus is active against a limited number of patients with AGC. pS6(Ser240/4) may be a potential predictive biomarker for everolimus, which requires validation. Careful monitoring is necessary despite generally favourable toxicity profile.

Topics: Adenocarcinoma; Adult; Aged; Antineoplastic Agents; Biomarkers, Tumor; Disease-Free Survival; Drug Resistance, Neoplasm; Everolimus; Female; Fluorouracil; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Patient Dropouts; Platinum Compounds; Sirolimus; Stomach Neoplasms; Treatment Outcome

Everolimus is a novel inhibitor of the mammalian target of rapamycin pathway, which is aberrantly activated in cancer cell. We conducted a phase I study of capecitabine plus everolimus (RAD001) in refractory gastric cancer patients.. Patients with metastatic gastric cancer and progression after prior chemotherapy were eligible. Four dose levels were planned as follows: Level 1, 5 mg bid/day of everolimus (D1-D21) and 500 mg/m(2) bid/day of capecitabine (D1-14); Level 2, 5 mg bid/day of everolimus (D1-D21) and 750 mg/m(2) bid/day of capecitabine (D1-14); Level 3, 5 mg bid/day of everolimus (D1-D21) and 1000 mg/m(2) bid/day of capecitabine (D1-14); and Level 4, 10 mg bid/day of everolimus (D1-D21) and 1000 mg/m(2) bid/day of capecitabine (D1-14). Treatment was repeated every 3 weeks until disease progression, patient refusal, or any serious adverse event.. Fifteen patients were enrolled in this study between November 2009 and April 2010. Fifteen patients were enrolled (median age, 50 years; men, 9). Six patients had received two previous chemotherapy regimens; six patients had three previous chemotherapy regimens before the study treatment. Thus, the majority of patients were heavily pretreated. The dose-limiting toxicities were grade 3 infection, grade 3 mucositis, and grade 3 hyperglycemia and hyponatremia. After a median follow-up duration of 5.6 months (range, 2.3-8.1 months), median PFS was 1.8 months (95% CI, 0.8-2.8 months). The maximum best change observed was a 28.7% decrease in sum of longest diameters when compared with baseline.. The combination of capecitabine and everolimus showed satisfactory toxicity profile and modest clinical benefit in patients with refractory gastric cancer. The recommended dose of capecitabine and everolimus was 650 mg/m(2) twice daily and 5 mg twice daily, respectively.

Topics: Adult; Aged; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Capecitabine; Deoxycytidine; Disease-Free Survival; Drug Resistance, Neoplasm; Everolimus; Female; Fluorouracil; Humans; Male; Maximum Tolerated Dose; Middle Aged; Sirolimus; Stomach Neoplasms; Treatment Outcome

To determine the pharmacokinetics and safety of RAD001 (everolimus) in Japanese patients with advanced solid tumors.. An open-label, non-randomized, dose-escalation Phase I study of RAD001 administered continuously once daily in a 28-day cycle was performed. The study had a '3 + 3' design, with three patients recruited to each of three successive cohorts treated with RAD001 at 2.5, 5.0 or 10.0 mg/day.. The pharmacokinetics of RAD001 in Japanese patients were similar to those previously determined in Caucasians. The drug safety profile was consistent with that of a mammalian target of rapamycin inhibitor. No dose-limiting toxicities were observed. One patient with esophageal cancer and one with gastric cancer treated with RAD001 at 10 mg/day showed marked tumor responses.. Treatment of Japanese cancer patients with RAD001 may be undertaken with the expectation that previously determined pharmacokinetic and safety profiles apply. The drug may hold promise for treatment of esophageal and gastric cancer.

Topics: Aged; Asian People; Colorectal Neoplasms; Dose-Response Relationship, Drug; Drug Administration Schedule; Esophageal Neoplasms; Everolimus; Female; Humans; Immunosuppressive Agents; Liver Neoplasms; Lung Neoplasms; Male; Middle Aged; Neoplasm Staging; Neoplasms; Sirolimus; Stomach Neoplasms; Survival Analysis; Thyroid Neoplasms; Treatment Outcome

PURPOSE Everolimus, an oral inhibitor of the mammalian target of rapamycin, has shown antitumor activity in gastric cancer in preclinical and phase I studies. This phase II study evaluated the efficacy and safety of everolimus in pretreated patients with advanced gastric cancer. PATIENTS AND METHODS Patients with advanced gastric cancer who experienced progression despite prior chemotherapy received everolimus 10 mg orally daily until disease progression or study discontinuation. The primary end point was disease control rate (DCR; ie, complete response, partial response, or stable disease). Secondary end points included progression-free survival (PFS), overall survival (OS), and safety. RESULTS Fifty-three patients were assessable (median age, 63 years; 51% and 49% received one or two prior chemotherapy regimens, respectively). Although no complete or partial response was obtained, a decrease in tumor size from baseline was observed in 45% of patients by central review. The DCR was 56.0% (95% CI, 41.3% to 70.0%); median PFS was 2.7 months (95% CI, 1.6 to 3.0 months). At a median follow-up time of 9.6 months, median OS was 10.1 months (95% CI, 6.5 to 12.1 months). Common grade 3 or 4 adverse events included anemia, hyponatremia, increased gamma-glutamyltransferase, and lymphopenia. Grade 1 or 2 pneumonitis was reported in eight patients (15.1%). CONCLUSION Everolimus monotherapy resulted in a promising DCR in patients with previously treated advanced gastric cancer. Adverse events are consistent with the reported safety profile of everolimus. These results warrant further evaluation in patients with advanced gastric cancer.

Topics: Adult; Aged; Everolimus; Female; Humans; Immunosuppressive Agents; Male; Middle Aged; Neoplasm Staging; Prospective Studies; Safety; Sirolimus; Stomach Neoplasms; Survival Rate; Treatment Outcome

Gastric cancer (GC) is a malignancy with high morbidity and mortality. Chinese dragon's blood is a traditional Chinese medicine derived from the red resin of Dracaena cochinchinensis (Lour.) S. C. Chen. However, the antigastric cancer effect of Chinese dragon's blood has not yet been reported. Herein, we demonstrated that Chinese dragon's blood ethyl acetate extract (CDBEE) suppressed the proliferative and metastatic potential of human gastric cancer MGC-803 and HGC-27 cells. CDBEE suppressed epithelial-mesenchymal transition in MGC-803 and HGC-27 cells. Moreover, CDBEE induced apoptotic and autophagic cell death in MGC-803 and HGC-27 cells. The cytotoxicity of CDBEE in human gastric epithelial GES-1 cells was dramatically weaker than that in human gastric cancer cells. Mechanistically, the activation of the mitogen-activated protein kinase (MAPK) signalling pathway was involved in the growth inhibition of MGC-803 and HGC-27 cells by CDBEE. Additionally, CDBEE-induced autophagic cell death was mediated by downregulation of the mammalian target of rapamycin (mTOR)-Beclin1 signalling cascade and upregulation of the ATG3/ATG7-LC3 signalling cascade. Importantly, CDBEE exhibited potent anti-GC efficacy in vivo without obvious toxicity or side effects. Therefore, CDBEE may be a promising candidate drug for the treatment of gastric cancer, especially for GC patients with aberrant MAPK signalling or mTOR signalling.

Topics: Apoptosis; Autophagy; Beclin-1; Down-Regulation; Dracaena; Humans; Mitogen-Activated Protein Kinases; Plant Extracts; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases

Topics: Adenomatous Polyps; Humans; Intestinal Polyposis; Neoplastic Syndromes, Hereditary; Sirolimus; Stomach Neoplasms

The tumor suppressor gene phosphatase and tensin homolog (PTEN) in PI3K/Akt/mTOR pathway is essential in inhibiting tumor growth and metastasis. However, whether the mutation of PTEN gene could induce tumorigenesis and impact the treatment of gastric cancer is still unclear. The purpose of the study was to investigate the combined treatment of gastric tumorigenesis using Rapamycin and Fluorouracil (5-Fu) through interfering with the Akt/mTOR pathway in a mouse model with PTEN conditional deletion. Three groups of mice were exposed for 5 days to Rapamycin and 5-Fu separately and together. The gene expression of the Akt/mTOR pathway, the protein expression of caspase-3 and p-Akt, p-S6K and p-4EBP1, and the pathological changes in stomachs were analyzed. Our study demonstrates that the conditional PTEN deletion in the cells of glandular stomach induces hyperplastic gastric tumors in mice. The combined Rapamycin administration with 5-Fu resulted in better outcomes than their separate administration for the treatment of gastric cancer by inhibiting the mTOR signal pathway. Our study indicates that Rapamycin has a synergistic interaction with chemotherapeutic 5-Fu, and demonstrates a potential therapeutic combination treatment on glandular stomach tumor with PTEN functional absence or aberrantly activated Akt/mTOR pathway. It provides important insights into the inhibition of the Akt/mTOR pathway in gastric cancer clinical therapy.

Topics: Animals; Cell Line, Tumor; Fluorouracil; Humans; Mice; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Sirolimus; Stomach Neoplasms

Targeting oncogenic genomic aberrations is an established therapeutic strategy in multiple tumor types. Molecular classification has uncovered a number of novel targets, and rapamycin-insensitive companion of mTOR (RICTOR) amplification has been identified in lung cancer. Further investigation assessing the therapeutic potential of RICTOR amplification as a novel target across advanced cancers is needed.. Tumor samples from 640 patients with metastatic solid tumors, primarily gastrointestinal and lung cancers were prospectively subjected to a next-generation sequencing (NGS) assay to identify molecular targets. Samples with NGS-detected RICTOR amplification were confirmed with FISH. A RICTOR-amplified patient-derived cell (PDC) line was generated and used to investigate the effectiveness of selective AKT, mTORC1, and mTORC1/2 inhibition.. NGS identified 13 (2%) of 640 patients with RICTOR-amplified tumors (6 gastric, 3 NSCLC, 1 SCLC, 1 CRC, 1 sarcoma, 1 MUO). Of the 13 patients, seven patients had RICTOR protein overexpression by IHC. The prevalence of RICTOR amplification in gastric cancer by NGS was 3.8% (6/160). FISH testing confirmed amplification (RICTOR/control >2) in 5/13 (38%) of samples, including four gastric cancers and one lung cancer. Treatment of a RICTOR amplified PDC with a selective AKT (AZD5363), selective mTORC1 (everolimus), dual mTORC1/2 (AZD2014), and the multi-target kinase inhibitor pazopanib demonstrated preferential sensitivity to the mTORC1/2 inhibitor (AZD2014). Knockdown of RICTOR reversed PDC sensitivity to AZD2014, validating the importance of RICTOR amplification to the PDC line.. RICTOR amplification is a rare but therapeutically relevant genomic alteration across solid tumors. Our results support further pre-clinical and clinical investigation with AZD2014 in RICTOR amplified gastric cancer and highlights the importance of genomic profiling.

Topics: Adult; Aged; Benzamides; Cell Line, Tumor; Everolimus; Female; Gene Expression Regulation, Neoplastic; High-Throughput Nucleotide Sequencing; Humans; Lung Neoplasms; Male; Mechanistic Target of Rapamycin Complex 1; Mechanistic Target of Rapamycin Complex 2; Middle Aged; Morpholines; Protein Kinase Inhibitors; Pyrimidines; Rapamycin-Insensitive Companion of mTOR Protein; Signal Transduction; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases

Gastric adenocarcinoma is the third most common cause of cancer-related death worldwide. Here we report a novel, highly-penetrant mouse model of invasive gastric cancer arising from deregulated Hedgehog/Gli2 signaling targeted to Lgr5-expressing stem cells in adult stomach. Tumor development progressed rapidly: three weeks after inducing the Hh pathway oncogene GLI2A, 65% of mice harbored in situ gastric cancer, and an additional 23% of mice had locally invasive tumors. Advanced mouse gastric tumors had multiple features in common with human gastric adenocarcinomas, including characteristic histological changes, expression of RNA and protein markers, and the presence of major inflammatory and stromal cell populations. A subset of tumor cells underwent epithelial-mesenchymal transition, likely mediated by focal activation of canonical Wnt signaling and Snail1 induction. Strikingly, mTOR pathway activation, based on pS6 expression, was robustly activated in mouse gastric adenocarcinomas from the earliest stages of tumor development, and treatment with rapamycin impaired tumor growth. GLI2A-expressing epithelial cells were detected transiently in intestine, which also contains Lgr5+ stem cells, but they did not give rise to epithelial tumors in this organ. These findings establish that deregulated activation of Hedgehog/Gli2 signaling in Lgr5-expressing stem cells is sufficient to drive gastric adenocarcinoma development in mice, identify a critical requirement for mTOR signaling in the pathogenesis of these tumors, and underscore the importance of tissue context in defining stem cell responsiveness to oncogenic stimuli.

Topics: Adenocarcinoma; Animals; beta Catenin; Disease Models, Animal; Epithelial Cells; Epithelial-Mesenchymal Transition; Hedgehog Proteins; Intestinal Mucosa; Kruppel-Like Transcription Factors; Mice; Mice, Nude; Neoplastic Stem Cells; Receptors, G-Protein-Coupled; Ribosomal Protein S6 Kinases; Sirolimus; Snail Family Transcription Factors; Stomach Neoplasms; TOR Serine-Threonine Kinases; Wnt Signaling Pathway; Zinc Finger Protein Gli2

Therapeutic targeting of tumor angiogenesis with VEGF inhibitors results in demonstrable, but transitory efficacy in certain human tumors and mouse models of cancer, limited by unconventional forms of adaptive/evasive resistance. In one such mouse model, potent angiogenesis inhibitors elicit compartmental reorganization of cancer cells around remaining blood vessels. The glucose and lactate transporters GLUT1 and MCT4 are induced in distal hypoxic cells in a HIF1α-dependent fashion, indicative of glycolysis. Tumor cells proximal to blood vessels instead express the lactate transporter MCT1, and p-S6, the latter reflecting mTOR signaling. Normoxic cancer cells import and metabolize lactate, resulting in upregulation of mTOR signaling via glutamine metabolism enhanced by lactate catabolism. Thus, metabolic symbiosis is established in the face of angiogenesis inhibition, whereby hypoxic cancer cells import glucose and export lactate, while normoxic cells import and catabolize lactate. mTOR signaling inhibition disrupts this metabolic symbiosis, associated with upregulation of the glucose transporter GLUT2.

Topics: Angiogenesis Inhibitors; Animals; Axitinib; Cell Line, Tumor; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Glucose; Glutamine; Glycolysis; Humans; Imidazoles; Indazoles; Indoles; Intestinal Neoplasms; Lactic Acid; Membrane Transport Proteins; Mice; Models, Biological; Neuroendocrine Tumors; Pancreatic Neoplasms; Pyrroles; Signal Transduction; Sirolimus; Stomach Neoplasms; Sunitinib; TOR Serine-Threonine Kinases; Up-Regulation

Neuroendocrine tumors (NETs) are a rare diverse group of malignancies occurring most commonly in the gastroenteropancreatic system and the lungs. The incidence of NETs is increasing worldwide; median survival for patients with metastatic NETs is 5-65 months. A growing body of evidence shows survival benefit in patients with advanced NETs (gastroenteropancreatic and lung) treated with mTOR inhibitor everolimus, with improvement in survival being demonstrated in the clinical trial and real-world setting. Everolimus has been shown to have a manageable safety profile, with the most common adverse events being stomatitis, rash, diarrhea, fatigue and infections. Due to the rarity of the condition, there are challenges in conducting clinical trials in these patients. Further research is required to clarify the role of adjuvant therapy, treatment sequencing and the use of multimodality treatments.

Topics: Clinical Trials as Topic; Combined Modality Therapy; Everolimus; Humans; Intestinal Neoplasms; Neoplasm Metastasis; Neuroendocrine Tumors; Pancreatic Neoplasms; Protein Kinase Inhibitors; Respiratory System; Sirolimus; Stomach Neoplasms

Mechanistic/mammalian target of rapamycin (mTOR) has emerged as a new potential therapeutic target for gastric cancer. Rapamycin and rapamycin analogs are undergoing clinical trials and have produced clinical responses in a subgroup of cancer patients. However, monotherapy with rapamycin at safe dosage fails to induce cell apoptosis and tumor regression which has hampered its clinical application. This has led to the exploration of more effective combinatorial regimens to enhance the effectiveness of rapamycin. In our present study, we have investigated the combination of rapamycin and a reactive oxygen species (ROS) inducer EF24 in gastric cancer. We show that rapamycin increases intracellular ROS levels and displays selective synergistic antitumor activity with EF24 in gastric cancer cells. This activity was mediated through the activation of c-Jun N terminal kinase and endoplasmic reticulum stress (ER) pathways in cancer cells. We also show that inhibiting ROS accumulation reverses ER stress and prevents apoptosis induced by the combination of rapamycin and EF24. These mechanisms were confirmed using human gastric cancer xenografts in immunodeficient mice. Taken together, our work provides a novel therapeutic strategy for the treatment of gastric cancer. The work reveals that ROS generation could be an important target for the development of new combination therapies for cancer treatment.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Benzylidene Compounds; Cell Line, Tumor; Cell Proliferation; Cell Survival; Drug Synergism; Endoplasmic Reticulum Stress; Gene Expression Regulation, Neoplastic; Humans; JNK Mitogen-Activated Protein Kinases; Mice; Piperidones; Reactive Oxygen Species; Sirolimus; Stomach Neoplasms; Xenograft Model Antitumor Assays

Mammalian target of rapamycin (mTOR) has emerged as a new potential therapeutic target for gastric cancer. However, a phase III clinical trial found that monotherapy with the mTOR inhibitor everolimus did not significantly improve the overall survival of patients with advanced gastric cancer. This has led to the exploration of more effective combinatorial regimens to enhance the effectiveness of mTOR inhibitors. Here, we demonstrate that Akt phosphorylation is increased in the rapamycin-resistant gastric cancer cell lines MGC803 and SGC7901. We further show that combined treatment with celecoxib and rapamycin results in an additive inhibitory effect on the growth of gastric cancer cells through suppression of rapamycin-induced Akt activation. Moreover, celecoxib upregulated the expression of the ubiquitin ligase casitas B-lineage lymphoma-b (Cbl-b). Knockdown of Cbl-b significantly attenuated celecoxib-mediated inhibition of Akt phosphorylation and impaired the additive anticancer effect of celecoxib and rapamycin. Our results suggest that celecoxib-mediated upregulation of Cbl-b is responsible, at least in part, for the additive antitumor effect of celecoxib and rapamycin via inhibition of rapamycin-induced Akt activation.

Topics: Adaptor Proteins, Signal Transducing; Animals; Apoptosis; Celecoxib; Cell Line, Tumor; Cyclooxygenase 2; Drug Resistance, Neoplasm; Gene Knockdown Techniques; Humans; Phosphatidylinositol 3-Kinases; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-cbl; Pyrazoles; Signal Transduction; Sirolimus; Stomach Neoplasms; Sulfonamides; TOR Serine-Threonine Kinases

Here we showed that pAMPKα and PTEN were down-regulated and p-mTOR, p-S6, p-4EBP1, MMP7, and DCN1 were up-regulated in human gastric cancer tissue samples as compared to that in the noncancerous tissues. Metformin inhibited tumor growth in mice. Also it enhanced cisplatin- or rapamycin-induced reduction of tumor growth as compared with treatment of either drug alone. In addition to activation of AMPK and suppression of the mTOR pathway, a series of increased and decreased genes expression were induced by metformin, including PTEN, MMP7, and FN1. We suggest that metformin could potentially be used for the treatment of gastric cancer especially in combination with cisplatin or rapamycin.

Topics: Adult; Aged; Animals; Antineoplastic Combined Chemotherapy Protocols; Blotting, Western; Cell Cycle; Cisplatin; Disease Models, Animal; Female; Flow Cytometry; Humans; Immunohistochemistry; Male; Metformin; Mice; Middle Aged; Oligonucleotide Array Sequence Analysis; Real-Time Polymerase Chain Reaction; Signal Transduction; Sirolimus; Stomach Neoplasms; Transcriptome; Xenograft Model Antitumor Assays

Long non-coding RNAs (lncRNAs), which have evolved as important gene expression modulators, are involved in human malignancies. The down-regulation of lncRNA growth arrest specific transcript 5 (GAS5) has been reported in several cancers, however, the underlying mechanism of lncRNA GAS5 in stomach cancer is poorly understood. In this study, we found that lncRNA GAS5 had lower expression in stomach cancer tissues than the normal counterparts. lncRNA GAS5 was shown to interact with Y-box binding protein 1 (YBX1), and lncRNA GAS5 knockdown was shown to accelerate YBX1 protein turnover without affecting YBX1 transcription. lncRNA GAS5 down-regulation reduced the YBX1 protein level, which decreased YBX1-transactivated p21 expression and abolished G1 phase cell cycle arrest in stomach cancer. These results delineate a novel mechanism of lncRNA GAS5 in suppressing stomach carcinogenesis, and the lncRNA GAS5/YBX1/p21 pathway we discovered may provide useful targets for developing lncRNA-based therapies for stomach cancer.

Topics: Adult; Aged; Aged, 80 and over; Cyclin-Dependent Kinase Inhibitor p21; Down-Regulation; Female; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Male; Middle Aged; Mutant Proteins; Protein Binding; RNA, Long Noncoding; Sirolimus; Stomach Neoplasms; Trans-Activators; Y-Box-Binding Protein 1

To investigate the role of RAD001 in the reversing of drug resistance of SGC7901/DDP, we cultured SGC7901/DDP cells with different groups of drugs (RAD001, cisplatin (DDP) alone, or the combination of RAD001 and DDP); after that, we detected the drug sensitivity, cell apoptosis, and levels of P-gp, MRP1, and survivin in the cells of SGC7901/DDP by MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphe-nyltetrazolium bromide) assay, flow cytometry, immunohistochemical analysis, and Western blot analysis. There was no significant difference between DDP 2.5-mg/L group and negative control group. When the cells were pretreated with RAD001 2.5, 5 nmol/L, the proliferation of SGC7901/DDP cells was inhibited by DDP 2.5 mg/L significantly, compared to negative control group, DDP 2.5-mg/L group, and RAD001 2.5, 5-nmol/L group, respectively (P < 0.05); there were significant differences between combination groups (P < 0.05). DDP 2.5 mg/L and RAD001 2.5 nmol/L did not induce apoptosis of SGC7901/DDP cells alone (P > 0.05). When SGC7901/DDP cells were pretreated with RAD001 2.5 nmol/L, DDP 2.5 mg/L increased the apoptosis rate significantly compared to groups of control and DDP 2.5 mg/L alone (P < 0.05). Immunohistochemical staining (Table 5, Fig. 2) and Western blot analysis (Fig. 3) indicated that when SGC7901/DDP cells were pretreated with RAD001 2.5 nmol/L, the expression of P-gp, MRP1, and survivin decreased by different degrees. Our results have confirmed that RAD001 in combination with DDP could overcome chemoresistance of SGC7901/DDP cells by decreasing the levels of P-gp, MRP1, and survivin through the mTOR pathway.

Topics: Antineoplastic Agents; Apoptosis; ATP Binding Cassette Transporter, Subfamily B, Member 1; Blotting, Western; Cell Line, Tumor; Cell Proliferation; Cisplatin; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Everolimus; Flow Cytometry; Humans; Immunohistochemistry; Inhibitor of Apoptosis Proteins; Inhibitory Concentration 50; Multidrug Resistance-Associated Proteins; Sirolimus; Stomach Neoplasms; Survivin; Time Factors

Advanced gastric cancer or gastro-oesophageal junction cancer after a failure of first line chemotherapy have poor outcome. Hereby, we present the first patient treated by radiotherapy with concurrent everolimus, a mTor inhibitor, for a reirradiation of metastasis invading left axillary, infraclavicular and supraclavicular lymph nodes in progression despite several lines of chemotherapy. After 6 months of follow-up, this association provided a satisfactory anti-tumor efficiency and tolerance. Nevertheless, clinical trials are needed in order to confirm this strategy for the treatment of gastric cancer metastasis.

Topics: Adenocarcinoma; Antineoplastic Agents; Chemoradiotherapy; Esophagogastric Junction; Everolimus; Humans; Lymph Nodes; Lymphatic Metastasis; Male; Middle Aged; Radionuclide Imaging; Retreatment; Sirolimus; Stomach Neoplasms; Treatment Failure

The present study aims to develop and explore the use of PEGylated rapamycin (RP-MPEG) micelles for the treatment of gastric cancer. RP-MPEG was synthesized and characterized by using IR, H(1) NMR and C(13) NMR. RP-MPEG was prepared in the form of micelles and characterized by using field emission scanning electron microscopy, dynamic light scattering, zeta sizer, chromatographic analyses and photostability studies. The cytotoxicity studies of RP-MPEG micelles were conducted on specific CRL 1739 human gastric adenocarcinoma and CRL 1658 NIH-3T3 mouse embryonic fibroblast cell lines. RP-MPEG micelles showed the particle size distribution of 125±0.26 nm with narrow size distribution (polydispersity index 0.127±0.01). The surface charge of RP-MPEG micelles was found to be -12.3 mV showing enhanced anticancer activity against the CRL 1739 human gastric adenocarcinoma cell lines with an IC50 value of 1 mcg/ml.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Cell Proliferation; Cells, Cultured; Dose-Response Relationship, Drug; Drug Carriers; Drug Design; Drug Screening Assays, Antitumor; Humans; Mice; Micelles; Nanoparticles; NIH 3T3 Cells; Particle Size; Polyethylene Glycols; Sirolimus; Stomach Neoplasms; Structure-Activity Relationship; Surface Properties; Surface-Active Agents

Neuroendocrine tumors of the gastroenteropancreatic tract remain a difficult array of neoplasia to treat. Treatment of advanced and metastatic gastroenteropancreatic neuroendocrine tumors has traditionally been difficult with few systemic treatment options. In 2011, two new targeted therapies, everolimus and sunitinib were approved for treatment of pancreatic neuroendocrine tumor. The approval of these agents led to an enhanced interest in exploring novel agents. This can be evidenced by the fact that this is the first year that ASCO assembled related abstracts under a separate title of neuroendocrine tumor. The annual American Society of Clinical Oncology (ASCO) conference in 2013 presented four abstracts (#4030, #4031, #4032, #4136) that shed light on new therapeutic options that help target the unique pathways involved in these neuroendocrine malignancies.

Topics: Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Everolimus; Humans; Indoles; Intestinal Neoplasms; Neuroendocrine Tumors; Octreotide; Pancreatic Neoplasms; Pyrroles; Sirolimus; Stomach Neoplasms; Sunitinib; Treatment Outcome

Although (177)Lu-octreotate is an effective treatment for patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs), some patients will fail or develop disease progression necessitating further treatment. We examined whether the safety and efficacy of everolimus after prior treatment with (177)Lu-octreotate is different from the published safety profile of everolimus in GEP-NETs. In this multicenter study, 24 GEP-NET patients were included. Adverse events were assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE), version 3.0. Tumor response was measured according to the Response Evaluation Criteria in Solid Tumors (RECIST), version 1.0. Major clinical adverse events (grade 3 or 4) during treatment with everolimus were hyperglycemia (20.8%), fatigue (8.3%), thrombocytopenia (8.3%), and elevated alanine transaminase levels (8.3%). By radiological review, there were four partial responses (16.7%), five patients (62.5%) with stable disease, and three patients (12.5%) with progressive disease. For two patients (8.3%), no data on tumor response were available. Median progression-free survival (PFS) was 13.1 months (95% CI, 11.5-21.2). Median PFS of the current study was longer when compared with the RADIANT-3 trial (13.1 vs 11.4 months) and shorter when compared with the RADIANT-1 trial (13.1 vs 16.7 months). In conclusion, the safety profile of everolimus is not influenced by previous treatment with peptide receptor radiotherapy.

Topics: Adult; Aged; Bone Neoplasms; Everolimus; Female; Follow-Up Studies; Humans; Immunosuppressive Agents; Intestinal Neoplasms; Liver Neoplasms; Lutetium; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Staging; Neuroendocrine Tumors; Octreotide; Pancreatic Neoplasms; Prognosis; Retrospective Studies; Safety; Sirolimus; Stomach Neoplasms; Survival Rate

Gastric neuroendocrine tumors (NET) are rare and are classified into 3 types: type 1 and 2 (characterized by hypergastrinemia), and type 3 (characterized by normal gastrin). Surgery is the standard procedure, and systemic treatment is reserved for unresectable disease. Currently, targeted therapies are being evaluated in NET. The activity of everolimus, an mTOR inhibitor, has been shown in pancreatic NET but not reported in type 3 gastric carcinoid tumors.. Here we report a case of a patient who, after multiple lines of systemic therapy, had a prolonged disease control of nearly 1 year, significant clinical benefit, and minor tumor shrinkage with oral everolimus 10 mg continuously.. There is no effective treatment for type 3 gastric carcinoid tumors. The frequency of mTOR expression in these tumors is not known, but the case reported here suggests that inhibition of this pathway may play an important role.

Topics: Antineoplastic Agents; Everolimus; Humans; Male; Middle Aged; Neuroendocrine Tumors; Sirolimus; Stomach Neoplasms; Tomography, X-Ray Computed; Treatment Outcome

Recent studies have revealed that PDGF plays a role in promoting progressive tumor growth in several cancers, including gastric cancer. Cancer-associated fibroblasts, pericytes, and lymphatic endothelial cells in stroma express high levels of PDGF receptor (PDGF-R); cancer cells and vascular endothelial cells do not. Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that increases the production of proteins that stimulate key cellular processes such as cell growth and proliferation, cell metabolism, and angiogenesis. In the present study, we examined the effects of PDGF-R tyrosine kinase inhibitor (nilotinib) and mTOR inhibitor (everolimus) on tumor stroma in an orthotopic nude mice model of human gastric cancer. Expression of PDGF-B and PDGF-Rβ mRNAs was associated with stromal volume. Treatment with nilotinib did not suppress tumor growth but significantly decreased stromal reactivity, lymphatic invasion, lymphatic vessel area, and pericyte coverage of tumor microvessels. In contrast, treatment with everolimus decreased tumor growth and microvessel density but not stromal reactivity. Nilotinib and everolimus in combination reduced both the growth rate and stromal reaction. Target molecule-based inhibition of cancer-stromal cell interaction appears promising as an effective antitumor therapy.

Topics: Adenocarcinoma; Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Drug Synergism; Everolimus; Female; Gene Expression; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Molecular Targeted Therapy; Proto-Oncogene Proteins c-sis; Pyrimidines; Receptor, Platelet-Derived Growth Factor beta; Signal Transduction; Sirolimus; Stomach Neoplasms; Stromal Cells; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays

We studied the effect of everolimus, an inhibitor of the mammalian target of rapamycin (mTOR) on human gastric cancer cell lines. Cell proliferation in 3 of 8 cell lines was effectively inhibited by everolimus. Basal phosphorylation level of 4E-BP1 (T37/46, T70) was significantly higher in everolimus-sensitive cells than in everolimus-resistant cells. In subcutaneous xenograft model, immunohistochemistry analysis revealed that everolimus-sensitive cells expressed high levels of phospho-4E-BP1 (T37/46). In conclusion, phosphorylation of 4E-BP1 may be a predictive biomarker of everolimus sensitivity in gastric cancer.

Topics: Adaptor Proteins, Signal Transducing; Antineoplastic Agents; Apoptosis; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Everolimus; Flow Cytometry; Humans; Immunohistochemistry; Phosphoproteins; Phosphorylation; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases

While the range of therapeutic options for well-differentiated gastroenteropancreatic neuroendocrine tumors has recently increased with the emergence of targeted therapies, such as mTOR inhibitors, there is no recent progress in the treatment of poorly differentiated neuroendocrine carcinomas (PDNECs). Since PDNECs have been shown to strongly express mTOR pathway components, the aim of the present study was to assess the antitumor effect of the mTOR inhibitor everolimus in preclinical models of PDNECs.. The expression of mTOR pathway components and their response to everolimus were assessed in two neuroendocrine cell lines: STC-1 and GluTag. A xenograft model of intrahepatic dissemination in the nude mouse, based on the intrasplenic injection of either STC-1 and GluTag tumor cells, was used. Animals were started on everolimus treatment 3 days after injection. The effects of treatment on tumor growth, proliferative capacities, apoptosis and in situ expression of mTOR pathway components were assessed.. The expression of mTOR pathway components was comparable in STC-1 and GluTag cells and in human PDNECs and could be inhibited in vitro by everolimus. In vivo, the tumor volume of STC-1 and GluTag xenografts was significantly reduced in treated animals (6.05 ± 1.84% as compared to 21.76 ± 3.88% in controls). Everolimus treatment also induced a significant decrease in Ki67 index and in the phosphorylation levels of the two major effectors of mTOR, p70S6K and 4E-BP1.. Our experimental data suggest that mTOR inhibition could be considered a therapeutic option for high-grade gastroenteropancreatic neuroendocrine tumors.

Topics: Adult; Aged; Animals; Antineoplastic Agents; Cell Line, Tumor; Everolimus; Female; Humans; Intestinal Neoplasms; Male; Mice; Mice, Nude; Middle Aged; Neuroendocrine Tumors; Pancreatic Neoplasms; Signal Transduction; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays

Topics: Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Bevacizumab; ErbB Receptors; Everolimus; Humans; Molecular Targeted Therapy; Sirolimus; Stomach Neoplasms; Trastuzumab

CXCL12/CXCR4 plays an important role in metastasis of gastric carcinoma. Rapamycin has been reported to inhibit migration of gastric cancer cells. However, the role of mTOR pathway in CXCL12/CXCR4-mediated cell migration and the potential of drugs targeting PI3K/mTOR pathway remains unelucidated. We found that CXCL12 activated PI3K/Akt/mTOR pathway in MKN-45 cells. Stimulating CHO-K1 cells expressing pEGFP-C1-Grp1-PH fusion protein with CXCL12 resulted in generation of phosphatidylinositol (3,4,5)-triphosphate, which provided direct evidence of activating PI3K by CXCL12. Down-regulation of p110β by siRNA but not p110α blocked phosphorylation of Akt and S6K1 induced by CXCL12. Consistently, p110β-specific inhibitor blocked the CXCL12-activated PI3K/Akt/mTOR pathway. Moreover, CXCR4 immunoprecipitated by anti-p110β antibody increased after CXCL12 stimulation and G(i) protein inhibitor pertussis toxin abrogated CXCL12-induced activation of PI3K. Further studies demonstrated that inhibitors targeting the PI3K/mTOR pathway significantly blocked the chemotactic responses of MKN-45 cells triggered by CXCL12, which might be attributed primarily to inhibition of mTORC1 and related to prevention of F-actin reorganization as well as down-regulation of active RhoA, Rac1, and Cdc42. Furthermore, rapamycin inhibited the secretion of CXCL12 and the expression of CXCR4, which might form a positive feedback loop to further abolish upstream signaling leading to cell migration. Finally, we found cells expressing high levels of cxcl12 were sensitive to rapamycin in its activity inhibiting migration as well as proliferation. In summary, we found that the mTOR pathway played an important role in CXCL12/CXCR4-mediated cell migration and proposed that drugs targeting the mTOR pathway may be used for the therapy of metastatic gastric cancer expressing high levels of cxcl12.

Topics: Actins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Chemokine CXCL12; Class Ia Phosphatidylinositol 3-Kinase; Down-Regulation; Feedback, Physiological; Furans; Gene Expression; Humans; Phosphatidylinositol 3-Kinases; Phosphorylation; Protein Binding; Proto-Oncogene Proteins c-akt; Pyridines; Pyrimidines; Receptors, CXCR4; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases

The purpose of this study was to explore the effect of trastuzumab in enhancing the activity of chemotherapeutic agents and the molecular basis of this effect. Two gastric cancer cell types with HER2 amplification, one sensitive (NCI‑N87) and one insensitive (MKN-7) to trastuzumab, were tested for the effects of trastuzumab on cell growth and cell signaling using MTS assay and western blotting, respectively. Interaction between trastuzumab and chemotherapeutic agents (fluorouracil, doxorubicin, cisplatin and paclitaxel) was evaluated by the combination index (CI). Fluorouracil-induced apoptosis was evaluated using western blot for poly (ADP-ribose) polymerase (PARP). Trastuzumab decreased phosphorylation of S6K, showed synergistic effect with fluorouracil or doxorubicin, and increased fluorouracil-induced apoptosis in NCI-N87 cells, but not in MKN-7 cells. While the mTOR inhibitor everolimus enhanced fluorouracil-induced apoptosis in both HER2-amplified cell lines, this was not the case in the gastric cancer cell lines without HER2 amplification. Consistently, while the EGFR/HER2 inhibitor Cl-387,785 inhibited cell growth of MKN-7, this growth inhibition did not accompany decrease in phosphorylation of S6K, and the compound did not enhance fluorouracil-induced apoptosis. In summary, inhibition of the mTOR/S6K signal may be a key molecular event in enhancing fluorouracil-induced apoptosis specifically in gastric cancer cells with HER2 amplification. mTOR inhibitors may therefore be attractive alternative drugs in gastric cancers with HER2 amplification regardless of their sensitivity to trastuzumab.

Topics: Antibodies, Monoclonal, Humanized; Antimetabolites, Antineoplastic; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cisplatin; Doxorubicin; Drug Screening Assays, Antitumor; Drug Synergism; Everolimus; Extracellular Signal-Regulated MAP Kinases; Fluorouracil; Gene Amplification; Humans; Paclitaxel; Quinazolines; Receptor, ErbB-2; Ribosomal Protein S6 Kinases; Signal Transduction; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases; Trastuzumab

The incidence of Kaposi sarcoma (KS) has substantially increased among immunocompromised patients, suggesting a role for immunosuppressive drugs. The aim of this study was to evaluate the incidence, features, and outcome of KS among 307 kidney transplantation patients at our center between January 1994 and June 2010. During the study period, the 10 patients who developed KS (3.25%) showed a mean age at transplantation of 35.8 ± 8.7 years (range, 22 to 49 years). The mean interval between transplantation and occurrence of KS was 24.7 ± 21.36 months (range, 6 to 64 months). The mean time of antithymocyte globulin induction was 9.5 days (range, 6 to 13 days). KS was restricted to the skin in 7 cases, among which, one presented with associated Hodgkin lymphoma. Visceral involvement (one lung and one colon) was observed in two cases. One patient presented with a gastric KS without skin lesions. Immunosuppressive treatment was reduced, then withdrawn in three cases, resulting in regression of KS a few weeks later, but with graft loss requiring hemodialysis at 1, 3 and 4 months. Among the remaining 7 cases, we stopped mycophenalate mofetil (MMF) and switched from calcineurin inhibitors to sirolimus. Allograft function remained stable after the switch. Only one patient who already had allograft dysfunction due to biopsy-proven chronic allograft nephropathy. Deteriorated progressively, undergoing hemodialysis at 2 years after KS diagnosis. In conclusion, we observed a relatively high incidence of KS among our cases. The introduction of sirolimus resulted in complete regression of KS lesions with preserved graft function.

Topics: Adult; Calcineurin Inhibitors; Colonic Neoplasms; Drug Substitution; Drug Therapy, Combination; Female; Graft Rejection; Graft Survival; Humans; Immunosuppressive Agents; Incidence; Kidney Transplantation; Lung Neoplasms; Male; Middle Aged; Renal Dialysis; Sarcoma, Kaposi; Sirolimus; Skin Neoplasms; Stomach Neoplasms; Time Factors; Treatment Outcome; Tunisia

Peritoneal dissemination occurs frequently in patients with unresectable advanced-stage gastric cancer. In this study, we tested the efficacy of the mTOR inhibitor RAD001 (everolimus) against advanced gastric cancer with peritoneal dissemination. Using the two cell lines, 58As1, a cell line exhibiting a high propensity for peritoneal metastasis, and its parental cell line, HSC-58, a human scirrhous gastric cancer cell line, we first examined the growth-inhibitory activity of everolimus in vitro. Methylene blue assay demonstrated a moderate inhibitory effect of the drug on both cell lines under normal culture conditions (maximal inhibitory effect: 50.5% at 1 μM, HSC-58, 65.3%, 58As1). However, under the hypoxic condition (1% O(2)), while the growth-inhibitory activity of everolimus was greatly reduced in the HSC-58 cell line, the degree of reduction of the inhibitory activity was much smaller in the 58As1 cell line. Western blotting revealed that the degree of phosphorylation of mTOR and its downstream signaling molecules, p70S6K and 4E-BP1, was decreased under hypoxic conditions in HSC-58. On the other hand, phospho-p70S6K and phospho-4E-BP1 remained active under hypoxic conditions in 58As1, the molecular activity was suppressed by everolimus. Cell-cycle analysis showed that hypoxia-induced G1 arrest was not manifested in the 58As1 cells, unlike in the HSC-58 cells. Separately, an in vivo orthotopic mouse model of 58As1 revealed that everolimus significantly reduced peritoneal dissemination as evaluated by the quantitative photon counting method. Taken together, our results suggest that everolimus may have favorable activity against gastric cancer, particularly in cases with peritoneal dissemination.

Topics: Adenocarcinoma, Scirrhous; Animals; Antineoplastic Agents; Cell Cycle; Cell Hypoxia; Cell Line, Tumor; Everolimus; Female; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Peritoneal Neoplasms; Phosphorylation; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases

We have reported that embryonic stem cell-expressed Ras (ERas) is expressed in human gastric cancer and is associated with its tumorigenicity. Here, we asked whether ERas plays a role in resistance to chemotherapy in gastric cancer.. To assess the cytotoxicity of chemotherapeutic agents, ERas-overexpressing human gastric cancer GCIY cells were exposed to anticancer agents, including CPT-11 and inhibitor of mammalian target of rapamycin (mTOR). We also investigated the mechanisms by which ERas induces chemoresistance.. ERas-overexpressing clones were significantly more resistant to CPT-11 than were the control (p<0.001). Administration of rapamycin was significantly cytotoxic to the ERas-overexpressing clones compared with the control (p<0.01). Electrophoresis mobility shift assay revealed that ERas enhanced nuclear factor (NF)-κB activity. PCR array demonstrated that ERas up-regulated several multidrug efflux transporter genes, including ABCG2.. ERas induces chemoresistance to CPT-11 via activation of phosphatidylinositol-3 kinase-protein kinase β mTOR pathway and NF-κB, and consequently results in up-regulation of ABCG2.

Topics: Antineoplastic Agents; Camptothecin; Cell Line, Tumor; Cell Proliferation; Cell Survival; DNA; DNA Topoisomerases, Type I; Drug Resistance, Neoplasm; Embryonic Stem Cells; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Inhibitory Concentration 50; Irinotecan; Models, Biological; NF-kappa B; Protein Binding; ras Proteins; Sirolimus; Stomach Neoplasms; Up-Regulation

We have previously reported the synergistic cytotoxic effects of Docetaxel (TXT) and S-1 in gastric cancer in vitro and in vivo, and the combination regimen is now under phase III clinical trail. In this study, to elucidate whether the rapamycin, the inhibitor of the mTOR (mammalian target of rapamaycin), can enhance the potentiation of TXT and 5-fluorouracil (5-Fu) in gastric carcinoma cells. Rapamycin inhibited the growth of TMK-1, MKN-28, MKN-45 and MKN-74 cell lines by MTT assay, and it demonstrated the cytostatic effects as G1 arrest shown by flowcytometry. However, the cytotoxic effects of 5-Fu, TXT and cisplatin were enhanced by 2 to 4 times with the concomitant administration of rapamycin. To clarify the mechanism of the potentiation, the expression changes of the enzymes relating DNA metabolism and cell growth signal transduction pathways were examined by western blot analysis. Interestingly, the expression of thymidilate synthase was markedly decreased by the administration of rapamycin in TMK-1 cells in a time- and dose-dependent manner. Moreover, rapamycin decreased the phosphorylation of 4E-BP1, the phosphorylation of ERK1/2 and enhanced the phosphorylation of c-Jun NH2-terminal kinase, and the activation of caspase of apoptotic pathways in combination with TXT. These results strongly indicate that the mTOR inhibitor can enhance the potentiation of TXT and 5-Fu or S-1 and can serve as a new therapeutic tool for advanced and recurrent gastric cancer patients.

Topics: Antibiotics, Antineoplastic; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Division; Cell Line, Tumor; Docetaxel; Extracellular Signal-Regulated MAP Kinases; Flow Cytometry; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Signal Transduction; Sirolimus; Stomach Neoplasms; Taxoids

Inhibition of mTORC1 with the mTOR inhibitor rapamycin may lead to an induction of Akt phosphorylation in cancer cells via mTORC2 activation. Using gastric and pancreatic cancer cells, we further investigated this paradoxical signaling response and found that rapamycin additionally up-regulates both IGF-IR and Her2 expression. Using RNAi for down-regulating RICTOR, this induction of receptor kinase expression was identified to be mediated via an mTORC2-induced Akt activation. Moreover, mTORC2 inhibition reduced the phosphorylation of GSK-3 and NF-kappaB, and significantly impaired cancer cell motility. In conclusion, inhibition of mTORC2 may abrogate unfavorable signaling effects of mTOR inhibitors, hence providing a novel rationale for therapy.

Topics: Blotting, Western; Carrier Proteins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Glycogen Synthase Kinase 3; Humans; NF-kappa B; Pancreatic Neoplasms; Phosphorylation; Rapamycin-Insensitive Companion of mTOR Protein; Receptor, ErbB-2; Receptor, IGF Type 1; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Sirolimus; Stomach Neoplasms; Transcription Factors

The vascular endothelial growth factor (VEGF) is a central mediator of tumor-induced angiogenesis. Everolimus, a mammalian target of rapamycin (mTOR) inhibitor, decreases VEGF-secretion of cancer cells. Vatalanib is a selective inhibitor of VEGF receptors 1-3. In the present study it was hypothesized that dual inhibition of VEGF signaling by inhibition of VEGF production and VEGF receptor signaling leads to synergistic anti-tumor effects. In vitro, effects of vatalanib and everolimus on cell proliferation, cell cycle, apoptosis and signal transduction were examined in three gastric cancer cell lines. Effects on angiogenesis were assessed using tube formation assays of cultured human umbilical vein endothelial cells (HUVECs). In vivo, the antitumor effect of compounds was studied using a gastric cancer xenograft nude mouse model. VEGF of murine origin (mVEGF) and human cancer cell-derived VEGF (hVEGF) were studied separately by specific ELISAs. Tumor vascularization and proliferation were quantified by immunohistochemistry. In vitro, everolimus but not vatalanib decreased gastric cancer proliferation without inducing apoptosis. Vatalanib abolished endothelial cell tube formation, whereas inhibition of tube formation by everolimus was incomplete. In vivo, the combination of vatalanib with everolimus was superior to single agent treatments and reduced tumor size by about 50% relative to everolimus monotherapy (p < 0.005). Pharmacodynamic analysis of VEGF plasma level showed a decrease of hVEGF by everolimus and indicated a trend towards lower mVEGF level only in the combination group. In line, there was a tendency for lower vascular density and proliferation for combination treatment. We conclude that in a preclinical model of gastric cancer the antitumor activity of vatalanib can be augmented by everolimus.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Cell Line, Tumor; Cell Proliferation; Drug Synergism; Enzyme-Linked Immunosorbent Assay; Everolimus; Humans; Immunosuppressive Agents; Mice; Mice, Nude; Neovascularization, Pathologic; Phthalazines; Protein Kinase Inhibitors; Pyridines; Receptors, Vascular Endothelial Growth Factor; Signal Transduction; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases; Tumor Burden; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

VEGF receptor blockage has been reported to increase serum VEGF. We hypothesized that mTOR inhibition by everolimus counteracts VEGF induction by sunitinib resulting in an improved anti-tumor activity of sunitinib. In vitro, sunitinib in combination with everolimus did not outperform the respective monotherapies. In vivo, monotherapies reduced tumor growth by 60%, whereas the combination of sunitinib and everolimus led to an almost complete tumor growth inhibition. This superior anti-tumor activity coincided with attenuation of VEGF peaks. In conclusion mTOR inhibition by everolimus counteracts VEGF induction by sunitinib and results in significant reduction of tumor burden and long-lasting tumor growth control.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Enzyme-Linked Immunosorbent Assay; Everolimus; Female; Humans; Immunohistochemistry; Immunosuppressive Agents; Indoles; Intracellular Signaling Peptides and Proteins; Mice; Mice, Nude; Protein Serine-Threonine Kinases; Pyrroles; Sirolimus; Stomach Neoplasms; Sunitinib; TOR Serine-Threonine Kinases; Transplantation, Heterologous; Vascular Endothelial Growth Factor A

Malignancies are a well-known complication of immunosuppressive therapy among renal transplant recipients, representing an important cause of long-term morbidity and mortality. Rapamycin has been shown to limit the proliferation of a number of malignant cell lines in vivo and in vitro.. Fifteen patients developed the following malignancies at a mean of 90.3 months (range = 10-252) after kidney transplantation: metastatic gastric cancer (n = 1), metastatic colon cancer (n = 1), bilateral nephrourothelioma (n = 1), skin cancer (n = 2), Kaposi's sarcoma (n = 2), posttransplant lymphoproliferative disorder (PTLD; n = 4), renal cell carcinoma T1 (n = 1), MALT lymphoma (n = 1), intramucous colon carcinoma (n = 1), liposarcoma of the spermatic cord (n = 1). After the diagnosis of malignancy, the patients were switched from calcineurin inhibitor-based immunosuppression to rapamycin (monotherapy, n = 3), or associated with steroids (n = 6) or with mycophenolate mofetil (n = 6).. Both patients with metastatic cancer underwent chemotherapy but succumbed after 6 and 13 months. Two patients with PTLD who underwent chemotherapy died after 12 and 36 months. At a mean follow-up of 32.7 months (range = 7-56), the remaining 11 patients are cancer-free. Two patients lost their grafts after 24 and 36 months after the switch due to chronic rejection. Renal graft function remained stable in all other patients from diagnosis throughout follow-up.. Our observations suggested that rapamycin-based immunosuppression offers the possibility for regression of nonmetastatic tumors. Nevertheless, it is difficult to assess whether tumor regression was due to rapamycin treatment or to the reduced immunosuppression.

Topics: Cell Division; Cell Line, Tumor; Colonic Neoplasms; Genital Neoplasms, Male; Humans; Immunosuppression Therapy; Immunosuppressive Agents; Kidney Transplantation; Liposarcoma; Male; Neoplasm Metastasis; Neoplasms; Sirolimus; Skin Neoplasms; Stomach Neoplasms

We evaluated RAD001, an inhibitor of the mammalian target of rapamycin (mTOR) in human gastric cancer cell lines and determined the molecular mechanisms. RAD001 has marked growth inhibitory activity against the SNU-1 and SNU-216 cells. It inhibited phosphorylation of mTOR and S6K, and induced G1 cell cycle arrest. Synergistic growth-inhibitory effects in combination with 5-fluorouracil (5-FU) was identified. Furthermore, RAD001 conferred sensitivity to 5-FU-resistant cell lines by downregulating thymidylate synthase (TS). In conclusion, RAD001 showed growth inhibitory activity against gastric cancer cells and acted synergistically with cytotoxic agents such as 5-FU by downregulating TS.

Topics: Cell Line, Tumor; Cell Proliferation; Drug Resistance, Neoplasm; Everolimus; Fluorouracil; G1 Phase; Humans; Intracellular Signaling Peptides and Proteins; Protein Serine-Threonine Kinases; Sirolimus; Stomach Neoplasms; Thymidylate Synthase; TOR Serine-Threonine Kinases

Topics: Adenocarcinoma; Adult; Antineoplastic Combined Chemotherapy Protocols; Esophageal Neoplasms; Esophagogastric Junction; Humans; Male; Phosphorylation; Receptor, ErbB-2; Sirolimus; Stomach Neoplasms; Thalidomide; TOR Serine-Threonine Kinases

The mammalian target of rapamycin (mTOR) plays a key role in cellular growth and homeostasis. The purpose of our present study is to investigate the expression of activated mTOR (p-mTOR) in gastric cancer patients, their prognostic significance and the inhibition effect of RAD001 on tumor growth and to determine whether targeted inhibition of mTOR could be a potential therapeutic strategy for gastric cancer.. The expression of p-mTOR was detected in specimens of 181 gastric cancers who underwent radical resection (R0) by immunohistochemistry. The correlation of p-mTOR expression to clinicopathologic features and survival of gastric cancer was studied. We also determined the inhibition effect of RAD001 on tumor growth using BGC823 and AGS human gastric cancer cell lines.. Immunostaining for p-mTOR was positive in 93 of 181 (51.4%) gastric cancers, closely correlated with lymph node status and pTNM stage. Patients with p-mTOR positive showed significantly shorter disease-free survival (DFS) and overall survival (OS) rates than those with p-mTOR-negative tumors in univariable analyses, and there was a trend toward a correlation between p-mTOR expression and survival in multivariable analyses. RAD001 markedly inhibited dose-dependently proliferation of human gastric carcinoma cells by down-regulating expression of p70s6k, p-p70s6k, C-myc, CyclinD1 and Bcl-2, up-regulating expression of P53.. In gastric cancer, p-mTOR is a potential therapeutic target and RAD001 was a promising treatment agent with inducing cell cycle arrest and apoptosis by down-regulating expression of C-myc, CyclinD1 and Bcl-2, up-regulating expression of P53.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Disease-Free Survival; Everolimus; Female; Gene Expression Regulation, Neoplastic; Humans; Immunohistochemistry; Male; Middle Aged; Retrospective Studies; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases; Treatment Outcome

The treatment of B-cell non-Hodgkin lymphoma, the most common posttransplant lymphoproliferative disorder, is not well defined. Herein we have reported a case of gastric mucosa-associated lymphoid tissue (MALT) lymphoma with rapid, persistent, and complete remission after conversion of the immunosuppression from cyclosporine (CsA) to sirolimus (SRL). A 42-year-old woman underwent renal transplantation in 1992 with no major abnormalities until 2006 when a gastroscopy performed to investigate dyspeptic symptoms showed a mixed MALT gastric lymphoma (with low- and high-grade components) associated with the presence of Helicobacter pylori infection. Two therapeutic interventions in a 1-week interval were performed: treatment of the H. pylori infection (omeprazole, amoxicillin, and clarithromycin for 14 days) and modification of the immunosuppression by substitution of CsA and azathioprine (AZA) with SRL. Control endoscopy performed 1 month later showed persistence of H. pylori infection and absence of the gastric tumor. New endoscopies performed at 2 and 7 months after therapy confirmed the absence of neoplasia and H. pylori eradication. Currently, the patient has no complaints, displaying a creatinine value of 1.8 mg/dL and a hemoglobin of 9.4 mg/dL using SRL and ibersatan. SRL has been studied extensively as an anticancer drug, acting as a mammalian target for rapamycin (mTOR) inhibitor. Accumulating data support the role of mTOR in lymphomagenesis. In conclusion, our case of gastric MALT lymphoma in a renal transplant patient displayed a complete remission after alteration of the immunosuppressive scheme with the introduction of SRL.

Topics: Adult; Azathioprine; Cyclosporine; Female; Gastric Mucosa; Helicobacter Infections; Helicobacter pylori; Humans; Immunosuppressive Agents; Kidney Transplantation; Living Donors; Lymphoma, B-Cell, Marginal Zone; Sirolimus; Stomach Neoplasms

The underlying mechanism regulating the expression of the cancer stem cell/tumor-initiating cell marker CD133/prominin-1 in cancer cells remains largely unclear, although knowledge of this mechanism would likely provide important biological information regarding cancer stem cells. Here, we found that the inhibition of mTOR signaling up-regulated CD133 expression at both the mRNA and protein levels in a CD133-overexpressing cancer cell line. This effect was canceled by a rapamycin-competitor, tacrolimus, and was not modified by conventional cytotoxic drugs. We hypothesized that hypoxia-inducible factor-1 alpha (HIF-1 alpha), a downstream molecule in the mTOR signaling pathway, might regulate CD133 expression; we therefore investigated the relation between CD133 and HIF-1 alpha. Hypoxic conditions up-regulated HIF-1 alpha expression and inversely down-regulated CD133 expression at both the mRNA and protein levels. Similarly, the HIF-1 alpha activator deferoxamine mesylate dose-dependently down-regulated CD133 expression, consistent with the effects of hypoxic conditions. Finally, the correlations between CD133 and the expressions of HIF-1 alpha and HIF-1 beta were examined using clinical gastric cancer samples. A strong inverse correlation (r = -0.68) was observed between CD133 and HIF-1 alpha, but not between CD133 and HIF-1 beta. In conclusion, these results indicate that HIF-1 alpha down-regulates CD133 expression and suggest that mTOR signaling is involved in the expression of CD133 in cancer cells. Our findings provide a novel insight into the regulatory mechanisms of CD133 expression via mTOR signaling and HIF-1 alpha in cancer cells and might lead to insights into the involvement of the mTOR signal and oxygen-sensitive intracellular pathways in the maintenance of stemness in cancer stem cells.

Topics: AC133 Antigen; Antigens, CD; Cell Line, Tumor; Chromones; Colorectal Neoplasms; Down-Regulation; Glycoproteins; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Lung Neoplasms; Morpholines; Neoplasms; Peptides; Protein Kinases; RNA, Messenger; Signal Transduction; Sirolimus; Stomach Neoplasms; Tacrolimus; TOR Serine-Threonine Kinases; Transcription, Genetic; Up-Regulation

Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Cetuximab; Clinical Trials as Topic; ErbB Receptors; Everolimus; HSP90 Heat-Shock Proteins; Humans; Lapatinib; Multicenter Studies as Topic; Quinazolines; Receptor, ErbB-2; Sirolimus; Stomach Neoplasms; Survival Analysis; Trastuzumab

Metronomic dosing of cytotoxic drugs such as cyclophosphamide has shown anti-angiogenic activity, most likely by inducing hypoxia in tumors. Hypoxia leads to activation of escape mechanisms allowing tumor cell survival. This potentially limits the activity of anti-angiogenic strategies. We hypothesized that mTORC1 inhibition by everolimus (RAD001) leads to suppression of HIF-1alpha and VEGF resulting in synergistic anti-tumor activity in combination with anti-angiogenically dosed cyclophosphamide. In vitro, effects of everolimus on mTORC1 signaling, proliferation, cell cycle, HIF-1alpha expression and VEGF secretion were evaluated in two gastric cancer cell lines. In vivo, anti-tumor activity of everolimus in combination with metronomic cyclophosphamide was studied in a NCI-N87 human gastric cancer SCID mouse xenograft model. Expression of Ki-67 and HIF-1alpha, activated caspase 3, microvascular density (MVD) and tumor necrotic area assessed. Everolimus decreased proliferation and attenuated production of HIF-1alpha as well as VEGF in gastric cancer cells in vitro. In vivo, everolimus significantly inhibited tumor growth. This anti-tumor activity was linked to a significant increase in tumor necrotic area (p < 0.02) and trends for decreased proliferation, increased apoptosis, decreased HIF-1alpha and lower tumor MVD (p = n.s.). The combination of everolimus and cyclophosphamide resulted in a striking and highly significant long-term tumor growth control compared to monotherapy (p < 0.001), which was associated with a sharp increase in central tumor necrosis (p < 0.001). In conclusion, the combination of everolimus and metronomic cyclophosphamide showed synergistic anti-tumor activity. Depriving cancer cells by everolimus of factors necessary for their survival under hypoxia induced by anti-angiogenic chemotherapy appears to be a promising approach for treatment of gastric cancer.

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Caspase 3; Cell Line, Tumor; Cell Proliferation; Cyclophosphamide; Drug Therapy, Combination; Enzyme Activation; Everolimus; Female; Humans; Immunohistochemistry; Ki-67 Antigen; Mice; Mice, SCID; Necrosis; Neovascularization, Pathologic; Random Allocation; Sirolimus; Stomach Neoplasms; Tumor Burden; Xenograft Model Antitumor Assays

The mammalian target of rapamycin (mTOR) has become an interesting target for cancer therapy through its influence on oncogenic signals, which involve phosphatidylinositol-3-kinase and hypoxia-inducible factor-1alpha (HIF-1alpha). Since mTOR is an upstream regulator of HIF-1alpha, a key mediator of gastric cancer growth and angiogenesis, we investigated mTOR activation in human gastric adenocarcinoma specimens and determined whether rapamycin could inhibit gastric cancer growth in mice. Expression of phospho-mTOR was assessed by immunohistochemical analyses of human tissues. For in vitro studies, human gastric cancer cell lines were used to determine S6K1, 4E-BP-1 and HIF-1alpha activation and cancer cell motility upon rapamycin treatment. Effects of rapamycin on tumor growth and angiogenesis in vivo were assessed in both a subcutaneous tumor model and in an experimental model with orthotopically grown tumors. Mice received either rapamycin (0.5 mg/kg/day or 1.5 mg/kg/day) or diluent per intra-peritoneal injections. In addition, antiangiogenic effects were monitored in vivo using a dorsal-skin-fold chamber model. Immunohistochemical analyses showed strong expression of phospho-mTOR in 60% of intestinal- and 64% of diffuse-type human gastric adenocarcinomas. In vitro, rapamycin-treatment effectively blocked S6K1, 4E-BP-1 and HIF-1alpha activation, and significantly impaired tumor cell migration. In vivo, rapamycin-treatment led to significant inhibition of subcutaneous tumor growth, decreased CD31-positive vessel area and reduced tumor cell proliferation. Similar significant results were obtained in an orthotopic model of gastric cancer. In the dorsal-skin-fold chamber model, rapamycin-treatment significantly inhibited tumor vascularization in vivo. In conclusion, mTOR is frequently activated in human gastric cancer and represents a promising new molecular target for therapy.

Topics: Adenocarcinoma; Animals; Antibiotics, Antineoplastic; Cell Hypoxia; Cell Line, Tumor; Cell Movement; Cell Proliferation; Disease Models, Animal; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Intestinal Neoplasms; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Neovascularization, Pathologic; Phosphatidylinositol 3-Kinases; Phosphorylation; Protein Kinases; Ribosomal Protein S6 Kinases, 70-kDa; Signal Transduction; Sirolimus; Stomach Neoplasms; Survival Rate; TOR Serine-Threonine Kinases; Vascular Endothelial Growth Factor A

AFP-producing gastric carcinoma (AFPGC) is a highly malignant variant of gastric cancer. An effective chemotherapy is needed to improve on the poor outcome of this disease. Survival signals activated by intracellular kinase networks could be involved in chemoresistance in malignant tumors. We investigated the role of a pivotal kinase pathway, the mammalian target of rapamycin complex 1 (mTORC1) pathway, in the effectiveness of chemotherapeutic agents in three AFPGC cell lines (GCIY, FU97 and Takigawa) as well as in four cell lines of conventional-type gastric carcinoma (CGC). AFPGC cells were generally resistant to multiple chemotherapeutic agents, including cisplatin, while CGC cells were generally sensitive. Downstream targets of mTORC1, including p70S6K and 4EBP1, were phosphorylated in all cell lines. Interestingly, cisplatin virtually abolished phosphorylation of p70S6K and 4EBP1 in CGC cells, while phosphorylation was maintained in cisplatin-treated AFPGC cells. The addition of rapamycin, an inhibitor of mTORC1, diminished the remaining activity of mTORC1 and significantly intensified the cytotoxic action of cisplatin in AFPGC cells. These results suggested that persistent activity of mTORC1 signals in cisplatin-treated AFPGC cells is involved in the mechanisms of cisplatin resistance in AFPGC. Finally, combined treatment of rapamycin and cisplatin significantly suppressed the subcutaneously implanted GCIY cells. In conclusion rapamycin may be a potential supplemental agent for the treatment of AFPGC when used in combination with cisplatin.

Topics: alpha-Fetoproteins; Animals; Antineoplastic Agents; bcl-2-Associated X Protein; Cell Line, Tumor; Cisplatin; Drug Resistance, Neoplasm; Humans; Male; Mice; Mice, Inbred BALB C; Protein Kinases; Signal Transduction; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases; Transcription Factors; Xenograft Model Antitumor Assays

To evaluate the relationship between mammalian target of rapamycin (mTOR) signaling pathway and histone acetylation in cell survival, cell cycle, gene expression and protein level on human gastric cancer cells.. Human gastric cancer cell lines, MKN45 and SGC7901 were treated with trichostatin A, rapamycin and/or LY294002, a PI3K inhibitor. Cell viability was analyzed by methylthiazolyl tetrazolium. Cell cycle distribution was evaluated by flow cytometry. The transcription level of p21(WAF1) gene was detected by using real-time polymerase chain reaction. Proteins were detected by Western blotting.. Cell viability remarkably reduced after treatment by more than two drugs (P< 0.01). Through flow cytometry assessment, MKN45 cells were arrested in G2 phase (P< 0.05), while SGC7901 cells were in G2 or G1 phase (P< 0.05) whether treated with single or more than two drugs. The expression of p21(WAF1) mRNA was remarkably increased in the gastric cancer cells treated with conjoined drugs (P< 0.01). Phosphorylation of Akt, p70S6K and 4E-BP1 was significantly reduced in cells treated with conjoined drugs (P< 0.01). And histone acetylation of H4/H3 was also increased in cells treated with conjoined drugs (P< 0.01).. mTOR singnaling pathway has an important relationship with histone acetylation in gastric cancer cell lines. There is a co-effect of mTOR inhibitor and histone deacetylase inhibitor on gastric cancer cells.

Topics: Acetylation; Adaptor Proteins, Signal Transducing; Blotting, Western; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Cell Survival; Chromones; Cyclin-Dependent Kinase Inhibitor p21; Flow Cytometry; Histones; Humans; Hydroxamic Acids; Morpholines; Phosphoproteins; Phosphorylation; Polymerase Chain Reaction; Protein Kinases; Proto-Oncogene Proteins c-akt; Reverse Transcriptase Polymerase Chain Reaction; Ribosomal Protein S6 Kinases, 70-kDa; RNA, Messenger; Signal Transduction; Sirolimus; Stomach Neoplasms; TOR Serine-Threonine Kinases

The incidence of Kaposi's sarcoma among recipients of solid organs is about 500 times the rate in the general population, suggesting a role for immunosuppression in its development. On the basis of these findings, we investigated the impact of sirolimus on cutaneous and disseminated visceral Kaposi's sarcoma in a renal-transplant recipient. The introduction of sirolimus in this patient allowed complete regression of Kaposi's sarcoma (cutaneous and visceral) with preservation of excellent renal function. Meanwhile, in view of the available observational reports, we think that sirolimus should be included in the standard treatment for Kaposi's sarcoma after transplantation, to permit remission of the sarcoma (both cutaneous and visceral) while preserving the renal function.

Topics: Adult; Antibiotics, Antineoplastic; Humans; Immunosuppression Therapy; Kidney Transplantation; Male; Sarcoma, Kaposi; Sirolimus; Skin Neoplasms; Stomach Neoplasms

The incidence of Kaposi's sarcoma (KS) is higher in organ transplant recipients. The lesions are mainly cutaneous and isolated visceral involvement is rare. We herewith report a 38-year-old male patient, who underwent a cadaveric donor renal transplantation for chronic interstitial nephropathy. His immunosuppression protocol consisted of corticosteroids, tacrolimus and mycophenolate mofetil. Twenty-five months later, he presented with diarrhea and epigastric pain. An upper gastrointestinal endoscopy revealed an ulcer in the body of the stomach. Histological examination coupled with immunohistochemistry was suggestive of KS. Detailed examination did not show any skin lesions. Computed tomography of the chest revealed multiple bilateral lung micronodules. The patient tested positive for anti-Herpes Human Virus (HHV8) antibodies. Tacrolimus and mycophenolate mofetil were withdrawn and rapamycin was introduced. This resulted in a regression of both stomach and pulmonary KS. One-year later, the patient developed an episode of acute rejection, which was successfully treated with bolus steroids. Our case suggests that rapamycin-based immunosuppression offers a promising approach to the management of post-transplant KS, particularly with visceral involvement.

Topics: Adult; Biopsy; Diagnosis, Differential; Endoscopy, Gastrointestinal; Follow-Up Studies; Humans; Immunosuppressive Agents; Kidney Transplantation; Lung Neoplasms; Male; Sarcoma, Kaposi; Sirolimus; Stomach Neoplasms; Tomography, X-Ray Computed

The signal transduction inhibitor imatinib is one of the latest breakthroughs in cancer pharmacotherapy. It is administered orally over prolonged periods of time for the treatment of gastro-intestinal stromal tumours. Routine therapeutic drug monitoring of blood plasma versus red blood cells over several years by liquid chromatography coupled tandem mass spectrometry has high-lighted a very intriguing phenomenon. Imatinib plasma availability decreases dramatically owing to a significant shift in the partition ratio of red blood cells versus plasma. The shift is enforced by combination with everolimus, another signal transduction inhibitor. These data warrant routine erythrocyte versus plasma monitoring to prevent unexpected alterations in drug efficacy during long-term treatment.

Topics: Antineoplastic Agents; Benzamides; Drug Resistance, Neoplasm; Erythrocytes; Everolimus; Gastrointestinal Stromal Tumors; Humans; Imatinib Mesylate; Immunosuppressive Agents; In Vitro Techniques; Mass Spectrometry; Piperazines; Plasma; Pyrimidines; Sirolimus; Stomach Neoplasms

Interleukin (IL-2) and IL-2Rbeta/gamma have been shown to be expressed in human carcinomas in culture and in situ. Recently, expression of endogenous IL-2 and IL-2R in the cytoplasm was found to be up-regulated in tumour cells undergoing mitosis. This observation suggested that similar to its role in lymphocytes, the IL-2/IL-R pathway is involved in the regulation of carcinoma cell proliferation. Metabolic labelling followed by immunoprecipitation and Western blot results showed that IL-2 in carcinomas was identical to that in human lymphocytes. However, tumour cells did not secrete IL-2 detectable by immunoassays, although membrane-associated IL-2 was detectable on a proportion of these cells cultured in the absence of exogenous IL-2. Antibodies to IL-2 failed to inhibit proliferation of carcinoma cells, but antibodies specific for the ligand-binding site of the IL-2R were growth inhibitory. Growth of tumour cells was also inhibited by the immunosuppressive drugs, cyclosporin A (CsA), FK506 and rapamycin (RPA), known to interfere with the IL-2 pathway in lymphocytes. To further confirm the role of endogenous IL-2 in the growth of carcinomas, tumour cells were incubated with an IL-2-specific antisense oligonucleotide. The treatment was shown to transiently inhibit IL-2 mRNA and IL-2 protein expression as well as proliferation of tumour cells. Tumour cells treated with IL-2-specific antisense oligonucleotide demonstrated increased apoptosis in comparison to untreated or sense oligonucleotide-treated control cells. The data indicate that in human carcinomas, endogenous IL-2 promotes growth and protects tumour cells from apoptosis.

Topics: Antibodies; Apoptosis; Carcinoma, Squamous Cell; Cell Division; Head and Neck Neoplasms; Humans; Interleukin-2; Jurkat Cells; Oligonucleotides, Antisense; Receptors, Interleukin-2; Sirolimus; Stomach Neoplasms; Tacrolimus; Tumor Cells, Cultured