sirolimus and Carcinoma--Neuroendocrine

A better understanding of molecular mechanisms responsible for tumorigenesis has allowed the development of targeted drugs designed to improve the outcome of cancer. In endocrine tumors, several molecules have demonstrated efficacy in terms of progression free survival during phase III trials such as vandetanib and cabozantinib in medullary thyroid carcinoma, sorafenib in differentiated thyroid carcinoma and everolimus or sunitinib for pancreatic neuroendocrine tumors. Rare cancer network has allowed ongoing phase III trials in malignant pheochromocytoma and adrenocortical carcinoma. However, to date no specific predictive biomarker has yet been identified for a personalized cancer medicine. We review recent advances in endocrine oncology concerning molecular targets identification, targeted therapies and predictive or prognostic markers.

Topics: Antineoplastic Agents; Carcinoma, Neuroendocrine; Clinical Trials, Phase III as Topic; Disease-Free Survival; Endocrine Gland Neoplasms; Everolimus; Humans; Indoles; Molecular Targeted Therapy; Neuroendocrine Tumors; Niacinamide; Pancreatic Neoplasms; Phenylurea Compounds; Piperidines; Prognosis; Pyrroles; Quinazolines; Sirolimus; Sorafenib; Sunitinib; Thyroid Neoplasms; Treatment Outcome

Neuroendocrine tumors (NETs) are heterogeneous in underlying tumor biology and clinical presentations. They are generally classified according to their degree of differentiation and sites of origin. Moreover, NETs are further characterized by their secreted bioactive neuroamine. The treatment paradigm used to be surgical intervention in early disease and mostly palliative nature in the metastatic setting. With an increase in the understanding of the molecular signaling pathways involved in tumor growth, there are various emerging treatment options for patients with advanced NETs. Somatostatin analogs have both anti-tumor effects as well as symptom palliation associated with the secreted neuropeptides. Peptide-radio-receptor treatment (PRRT) using radio-labeled peptides which binds to somatostatin receptor is a useful anti-tumor treatment but limited by general availability. Sunitinib, a multi-targeted tyrosine kinase inhibitor, has recently been shown to improve the survival of pancreatic NETs patients. Similarly, the use of an mTOR inhibitor--everolimus, either alone or in combination with somatostatin analogs have demonstrated encouraging efficacy in treating advanced NETs. The success of these two agents in pancreatic NETS supports the notion that targeting angiogenesis and/or PI3K/AKT/mTOR pathway is an important strategy for making therapeutic advances in this disease. There are now many ongoing trials in exploring the role of other novel agents in treating patients with pancreatic NETs or carcinoid. The major plaguing problem in this era is the differential response to biological agents amongst NETs of different anatomical origins. Pancreatic NETs are generally more responsive to both chemotherapy and targeted agents than NETs of other sites. Thus, the development of potential predictive and prognostic biomarkers to tailor various molecular therapies to different NETs populations is a major unmet need.

Topics: Antineoplastic Agents; Carcinoma, Neuroendocrine; Everolimus; Gene Expression Regulation, Neoplastic; Humans; Indoles; Molecular Targeted Therapy; Neuroendocrine Tumors; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Pyrroles; Radiopharmaceuticals; Signal Transduction; Sirolimus; Somatostatin; Sunitinib; TOR Serine-Threonine Kinases

Neuroendocrine carcinomas are rare neoplasms although of increasing incidence and concern. While traditionally considered of indolent nature, once they progress beyond surgical resectability, the outcome is ultimately fatal for the majority of patients. Somatostatin analogs are useful to control symptoms in functioning tumors and may slow tumor progression in certain disease settings, but sensitivity to conventional cytotoxic chemotherapy is rather limited. In this context, results of the recently published randomized trials with sunitinib and everolimus have demonstrated for the first time that there are agents able to positively impact on the natural history of this complex disease. In this review, we will discuss available data on angiogenesis and mammalian target of rapamycin inhibitors for the treatment of advanced well-differentiated gastroenteropancreatic neuroendocrine tumors.

Topics: Angiogenesis Inhibitors; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Neuroendocrine; Clinical Trials as Topic; Everolimus; Gastrointestinal Neoplasms; Humans; Indoles; Molecular Targeted Therapy; Neovascularization, Pathologic; Pancreatic Neoplasms; Pyrroles; Randomized Controlled Trials as Topic; Sirolimus; Sunitinib; TOR Serine-Threonine Kinases

Enteropancreatic (EP) neuroendocrine carcinomas (NECs) represent relatively rare and heterogeneous malignancies. They are the most common group among neuroendocrine tumors (NETs). In most cases they are advanced at diagnosis and slow-growing, therefore conditioning a better prognosis compared with non neuroendocrine carcinomas from the same sites. No standard medical therapy exists, except for somatostatin analogs in functioning tumors, and octreotide LAR in functioning or non functioning well differentiated NECs from small bowel. Several systemic therapeutic options exist, including chemotherapy, somatostatin analog, interferon, peptide receptor radionuclide therapy (PRRT), and molecular targeted drugs. Among them some therapies have specific biological tumor targets and can be defined as "biological targeted therapies". This review focuses on the status of EP NECs targeted therapies in the light of recent advances. Somatostatin receptors (SSTRs) are the first therapeutic target detected in EP NECs. Through them SS analogs and PRRT act, producing symptomatic, biochemical, and, to a lesser extent, antiproliferative effects. New SS analogs, covering a higher number of SSTR subtypes, were developed, including pasireotide (SOM230), which controls 25% of carcinoid syndromes resistant to full dose octreotide LAR. Chimeric analogs, which bind SSTR2/SSTR5 and dopamine-2 receptor subtype (D2), are in preclinical phase of development. Among the numerous molecular targeted agents investigated in NETs, mTOR inhibitors and VEGF/VEGFR/PDGFR inhibitors are in most advanced clinical phase of investigation. In particular, everolimus, sunitinib, and bevacizumab are all studied in phase III trials. Both everolimus and sunitinib produced significant survival benefit versus placebo in advanced progressing well-differentiated pancreatic NECs. Sunitinib data have been presented at the last ASCO in June 2010, and everolimus data will be presented at next ESMO in September 2010.

Topics: Angiogenesis Inhibitors; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Bevacizumab; Carcinoma, Neuroendocrine; Everolimus; Humans; Indoles; Molecular Targeted Therapy; Pancreatic Neoplasms; Pyrroles; Receptors, Somatostatin; Sirolimus; Somatostatin; Sunitinib; Vascular Endothelial Growth Factor A

Targeted biologic agents showed clinically meaningful efficacy as front-line therapy for advanced radioiodine-refractory and medullary thyroid cancer. The clinical benefit of these agents beyond the front line has yet to be established.. We assessed the clinical benefit of targeted agents in patients with advanced differentiated and medullary thyroid cancer treated at a single academic cancer center. We determined efficacy and compared front-line and second-line benefit using biochemical and anatomic response, time to treatment failure, and progression-free survival (PFS). Statistical differences were assessed by t test and chi-square test. Survival curves were generated by the Kaplan-Meier method. Differences in survival were assessed using the log-rank test, and a p value <.05 was considered significant.. We identified 39 patients with advanced differentiated and medullary thyroid cancer treated with targeted biologic agents. Median age was 56.3 years. Overall, 25 men and 14 women participated. Histology showed 23% medullary and 77% differentiated cancer. Nineteen patients progressed on front-line therapy and subsequently received second-line therapy. Targeted agents conferred clinically meaningful benefit in the second-line setting in terms of biochemical response (13.3%), clinical benefit (83.3%), median time to treatment failure (4.0 months; 95% confidence interval: 2.6-8.2), and median PFS (4.6 months; 95% confidence interval: 3.2-8.2). Second-line benefit (median PFS) was more modest in comparison to the front-line setting in both genders (women: 3 months vs. 12.2 months; men: 6 months vs. 19.7 months), in differentiated cancers (4.1 months vs. 15.7 months), and with vascular targeting agents (4.4 months vs. 20.1 months).. Patients with advanced thyroid cancer derived meaningful clinical benefit from additional therapy with a biologic agent following disease progression on front-line targeted therapy.

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Neuroendocrine; Disease-Free Survival; Everolimus; Female; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Molecular Targeted Therapy; Niacinamide; Phenylurea Compounds; Piperidines; Quinazolines; Retrospective Studies; Sirolimus; Sorafenib; Thyroid Neoplasms; Treatment Outcome

Standard cytotoxic treatments for neuroendocrine tumours have been associated with limited activity and remarkable toxicity. A phase II study was designed to evaluate the efficacy, safety and pharmacodynamics of temsirolimus in patients with advanced neuroendocrine carcinoma (NEC). Thirty-seven patients with advanced progressive NEC received intravenous weekly doses of 25 mg of temsirolimus. Patients were evaluated for tumour response, time to progression (TTP), overall survival (OS) and adverse events (AE). Twenty-two archival specimens, as well as 13 paired tumour biopsies obtained pretreatment and after 2 weeks of temsirolimus were assessed for potential predictive and correlative markers. The intent-to-treat response rate was 5.6% (95% CI 0.6-18.7%), median TTP 6 months and 1-year OS rate 71.5%. The most frequent drug-related AE of all grades as percentage of patients were: fatigue (78%), hyperglycaemia (69%) and rash/desquamation (64%). Temsirolimus effectively inhibited the phosphorylation of S6 (P=0.02). Higher baseline levels of pmTOR (phosphorylated mammalian target of rapamycin) (P=0.01) predicted for a better response. Increases in pAKT (P=0.041) and decreases in pmTOR (P=0.048) after treatment were associated with an increased TTP. Temsirolimus appears to have little activity and does not warrant further single-agent evaluation in advanced NEC. Pharmacodynamic analysis revealed effective mTOR pathway downregulation.

Topics: Adult; Aged; Antineoplastic Agents; Carcinoid Tumor; Carcinoma, Neuroendocrine; Disease Progression; Exanthema; Fatigue; Female; Follow-Up Studies; Humans; Hyperglycemia; Infusions, Intravenous; Male; Middle Aged; Pancreatic Neoplasms; Phosphorylation; Protein Kinases; Proto-Oncogene Proteins c-akt; Ribosomal Protein S6; Sirolimus; Survival Analysis; TOR Serine-Threonine Kinases; Treatment Outcome

Genetic alterations in human cancers and murine models indicate that retinoblastoma (Rb) and p53 have critical tumor suppressive functions in retinoblastoma, a tumor of neural origin, and neuroendocrine tumors including small cell lung cancer and medullary thyroid cancer (MTC). Rb inactivation is the initiating lesion in retinoblastoma and current models propose that induction of apoptosis is a key p53 tumor suppressive function. Genetic studies in mice, however, indicate that other undefined p53 tumor suppressive functions are operative in vivo. How p53 loss cooperates with Rb inactivation to promote carcinogenesis is also not fully understood. In the current study, genetically engineered mice were generated to determine the role of Rb and p53 in MTC pathogenesis and test the hypothesis that p53 suppresses carcinogenesis by inhibiting mammalian target of rapamycin (mTOR) signaling. Conditional Rb ablation resulted in thyroid tumors mimicking human MTC, and additional p53 loss led to rapid tumor progression. p53 suppressed tumorigenesis by inhibiting cell cycle progression, but did not induce apoptosis. On the contrary, p53 loss led to increased apoptosis that had to be overcome for tumor progression. The mTOR activity was markedly increased in p53-deficient tumors and rapamycin treatment suppressed tumor cell growth, identifying mTOR inhibition as a critical p53 tumor suppressive function. Rapamycin treatment did not result in AKT/mitogen-activated protein kinase activation, providing evidence that this feedback mechanism operative in other cancers is not a general response to mTORC1 inhibition. Together, these studies provide mechanistic links between genetic alterations and aberrant signaling pathways critical in carcinogenesis, and identify essential Rb and p53 tumor suppressive functions in vivo.

Topics: Animals; Apoptosis; Carcinoma, Neuroendocrine; Cell Line, Tumor; Cell Proliferation; Cell Transformation, Neoplastic; Humans; Mice; Mitogen-Activated Protein Kinases; Retinoblastoma Protein; Signal Transduction; Sirolimus; Thyroid Neoplasms; TOR Serine-Threonine Kinases; Tumor Suppressor Protein p53

Neuroendocrine tumors (NETs) are highly vascularized neoplasms characterized by rising incidence. Moreover, the neuroendocrine cells were shown to express vascular endothelial growth factor (VEGF) and VEGF receptors. Therefore, angiomodulators could be potentially a new group of drugs enhancing still unsatisfactory effectiveness of NET therapy. The aim of this study was to assess the direct influence of angiomodulators: VEGF and five endogenous and exogenous antiangiogenic compounds (endostatin, interferon alpha [IFNα], rapamycin, JV1-36, semaxinib [SU5416]) on the growth of two NET cell lines: lung carcinoid H727 cell line and medullary thyroid cancer TT cell line in vitro. IFNα and rapamycin induced the inhibitory effect on H727 and TT cell viability and proliferation, increasing apoptosis and arresting the cell cycle. Also semaxinib (10(-5)M) inhibited proliferation of both cell lines. VEGF and endostatin did not influence the growth of H727 and TT cells. The inhibitory effect of IFNα, rapamycin and semaxinib on carcinoid and medullary thyroid cancer growth was revealed in our in vitro study, although some other antiangiogenic agents did not directly influence H727 and TT cell growth. Thus, IFNα and mTOR inhibitors as multidirectionally acting drugs with antiangiogenic effect could be potentially efficient in treatment of neuroendocrine tumors and are worth further studies.

Topics: Angiogenesis Inhibitors; Apoptosis; Calcitonin; Carcinoid Tumor; Carcinoma, Neuroendocrine; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Humans; Interferon-alpha; Lung Neoplasms; Sirolimus; Thyroid Neoplasms

The patient was an asymptomatic 43-year-old woman. Abdominal ultrasonography and enhanced computed tomography showed a tumor lesion accompanied by multiple cystic changes in the liver and the pancreatic tail. Endoscopic ultrasound-fine needle aspiration was performed on the pancreatic tumor lesion and revealed pancreatic neuroendocrine tumor (PNET). As it was unresectable due to multiple liver metastases, the decision was made to initiate treatment with everolimus and transcatheter arterial chemoembolization. The patient ceased menstruating after the start of everolimus administration. When the administration was discontinued due to interstitial lung disease, menstruation resumed, but then again stopped with everolimus resumption. An association between everolimus and amenorrhea was highly suspected. Amenorrhea occurred as a rare adverse event of everolimus. As the younger women might be included in PNETs patients, we should put this adverse event into consideration.

Topics: Adult; Amenorrhea; Antineoplastic Agents; Biomarkers, Tumor; Carcinoma, Neuroendocrine; Chemoembolization, Therapeutic; Endoscopic Ultrasound-Guided Fine Needle Aspiration; Everolimus; Female; Humans; Immunohistochemistry; Liver Neoplasms; Menstruation; Pancreatic Neoplasms; Sirolimus; Tomography, X-Ray Computed

A 55-year-old woman presented to our hospital with a chief complaint of abdominal pain. Computed tomography (CT) revealed a massive tumor originating from the tail of the pancreas, with liver and lymph node metastasis. Percutaneous biopsy was performed and yielded a diagnosis of pancreatic neuroendocrine carcinoma. The patient underwent distal pancreatectomy, lateral segmentectomy of the liver, para-aortic lymph node dissection, and cytoreductive surgery for treatment of peritoneal dissemination. Octreotide was administered on post-operative day (POD) 3. Treatment with everolimus (10 mg/day) was initiated on POD 32. Stable disease according to the Response Evaluation Criteria in Solid Tumors( RECIST) was observed for 4 months, and the patient survived for a total of 9 months after surgery. Everolimus was tolerated safely and was effective for the treatment of pancreatic neuroendocrine carcinoma.

Topics: Antineoplastic Agents; Carcinoma, Neuroendocrine; Chemotherapy, Adjuvant; Everolimus; Fatal Outcome; Female; Humans; Middle Aged; Palliative Care; Pancreatic Neoplasms; Sirolimus

Inhibition of mTOR is commonly considered a valid target in cancer treatment, but this assertion does not address effects on the immune microenvironment that may be detrimental to cancer treatment. Here we show how administration of the mTOR inhibitor RAD001 (everolimus) results in the occurrence of distant metastasis in a rat model of pancreatic cancer. RAD001 was administered twice weekly for 4.5 weeks as a single treatment or combined with [(177)Lu-DOTA,Tyr3]octreotate ((177)Lu-DOTATATE), where the latter targets the somatostatin receptor-2. The hypothesized synergistic therapeutic effect of RAD001 combined with (177)Lu-DOTATATE was, however, not observed in our experiments. The combination was shown to be less effective than (177)Lu-DOTATATE alone. Unexpectedly, tumor metastasis was observed in 77% of the subjects treated with RAD001, either alone or as part of the combination treatment. This was a striking effect, because metastasis did not occur in control or (177)Lu-DOTATATE-treated animals, including those where the primary tumor was surgically removed. These findings may be important clinically among noncompliant patients or patients that discontinue RAD001 therapy because of adverse effects.

Topics: Animals; Antineoplastic Agents; Carcinoma, Neuroendocrine; Cell Line, Tumor; Disease Models, Animal; Everolimus; Humans; Male; Mice; Mice, Nude; Neoplasm Metastasis; Pancreatic Neoplasms; Rats; Rats, Inbred Lew; Sirolimus; TOR Serine-Threonine Kinases

Topics: Antineoplastic Agents; Carcinoma, Neuroendocrine; Disease Progression; Everolimus; Female; Humans; Immunosuppressive Agents; Middle Aged; Pilot Projects; Sirolimus; Thyroid Neoplasms

Clinical trials using kinase inhibitors have demonstrated transient partial responses and disease control in patients with progressive medullary thyroid cancer (MTC). The goal of this study was to identify potential combinatorial strategies to improve on these results using sorafenib, a multikinase inhibitor with activity in MTC, as a base compound to explore signaling that might predict synergystic interactions. Two human MTC cell lines, TT and MZ-CRC-1, which harbor endogenous C634W or M918T RET mutations, respectively, were exposed to sorafenib, everolimus, and AZD6244 alone and in combination. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrasodium bromide (MTT) and poly (ADP-ribose) polymerase (PARP) cleavage assays were performed to measure cell survival and apoptosis. Western blots were performed to confirm activity of the compounds and to determine possible mechanisms of resistance and predictors of synergy. As a solitary agent, sorafenib was the most active compound on MTT assay. Western blots confirmed that sorafenib, everolimus, and AZD6244 inhibited their anticipated targets. At concentrations below its IC(50), sorafenib-treated TT and MZ-CRC-1 cells demonstrated transient inhibition and then re-activation of Erk over 6 h. In concordance, synergistic effects were only identified using sorafenib in combination with the Mek inhibitor AZD6244 (P<0.001 for each cell line). Cells treated with everolimus demonstrated activation of Akt and Ret via TORC2 complex-dependent and TORC2 complex-independent mechanisms respectively. Everolimus was neither additive nor syngergistic in combination with sorafenib or AZD6244. In conclusion, sorafenib combined with a Mek inhibitor demonstrated synergy in MTC cells in vitro. Mechanisms of resistance to everolimus in MTC cells likely involved TORC2-dependent and TORC2-independent pathways.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Benzenesulfonates; Benzimidazoles; Carcinoma; Carcinoma, Neuroendocrine; Cell Line, Tumor; Cell Survival; Drug Synergism; Everolimus; Extracellular Signal-Regulated MAP Kinases; Humans; MAP Kinase Signaling System; Niacinamide; Phenylurea Compounds; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-ret; Pyridines; Sirolimus; Sorafenib; Thyroid Neoplasms; TOR Serine-Threonine Kinases

Epidermal growth factor receptor (EGFR) and mammalian target of rapamycin (mTOR) are crucial targets in cancer therapy. Combined inhibition of both targets yielded synergistic effects in vitro and in vivo in several cancer entities. However, the impact of EGFR and mTOR expression and combined inhibition in neuroendocrine lung tumors other than small-cell lung cancer remains unclear.. Expression and activation of EGFR/AKT/mTOR pathway constituents were investigated in typical and atypical bronchial carcinoid (AC) tumors and large-cell neuroendocrine lung carcinomas (LCNEC) by immunohistochemistry in 110 tumor samples, and correlated with clinicopathological parameters and patient survival. Cytotoxicity of mTOR inhibitor everolimus and EGFR inhibitor erlotinib alone and in combination was assessed using growth inhibition assay in NCI-H720 AC and SHP-77 LCNEC cells. Cell cycle phase distribution was determined by FACS. Apoptosis-associated activation of caspase-3/7 was measured by Caspase-Glo® assay. Activity status of EGFR and mTOR pathway components was analyzed by immunoblotting.. Activation of the EGFR/AKT/mTOR axis could be demonstrated in all entities and was significantly increased in higher grade tumors. Neoadjuvant chemotherapy correlated significantly with p-AKT expression and p-ERK loss. Erlotinib combined with everolimus exerted synergistic combination effects in AC and LCNEC cells by induction of apoptosis, while cell cycle phase distribution remained unaffected. These effects could be explained by synergistic downregulation of phospho-mTOR, phospho-p70S6 kinase and phospho-AKT expression by everolimus and erlotinib.. Our study indicates that EGFR and mTOR are clinically important targets in bronchial neuroendocrine tumors, and further in vivo and clinical exploration of combined inhibition is warranted.

Topics: Adolescent; Adult; Aged; Antineoplastic Agents; Carcinoma, Bronchogenic; Carcinoma, Neuroendocrine; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Survival; Child; ErbB Receptors; Erlotinib Hydrochloride; Everolimus; Female; Humans; Lung Neoplasms; Male; Middle Aged; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Quinazolines; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Young Adult

We sought to determine whether phosphoinositide 3-kinase (PI3K) pathway mutation or activation state and rapamycin-induced feedback loop activation of Akt is associated with rapamycin sensitivity or resistance.. Cancer cell lines were tested for rapamycin sensitivity, Akt phosphorylation, and mTOR target inhibition. Mice injected with breast or neuroendocrine cancer cells and patients with neuroendocrine tumor (NET) were treated with rapalogs and Akt phosphorylation was assessed.. Thirty-one cell lines were rapamycin sensitive (RS) and 12 were relatively rapamycin resistant (RR; IC(50) > 100 nmol/L). Cells with PIK3CA and/or PTEN mutations were more likely to be RS (P = 0.0123). Akt phosphorylation (S473 and T308) was significantly higher in RS cells (P < 0.0001). Rapamycin led to a significantly greater pathway inhibition and greater increase in p-Akt T308 (P < 0.0001) and p-Akt S473 (P = 0.0009) in RS cells. Rapamycin and everolimus significantly increased Akt phosphorylation but inhibited growth in an in vivo NET model (BON). In patients with NETs treated with everolimus and octreotide, progression-free survival correlated with p-Akt T308 in pretreatment (R = 0.4762, P = 0.0533) and on-treatment tumor biopsies (R = 0.6041, P = 0.0102). Patients who had a documented partial response were more likely to have an increase in p-Akt T308 with treatment compared with nonresponders (P = 0.0146).. PIK3CA/PTEN genomic aberrations and high p-Akt levels are associated with rapamycin sensitivity in vitro. Rapamycin-mediated Akt activation is greater in RS cells, with a similar observation in patients with clinical responses on exploratory biomarker analysis; thus feedback loop activation of Akt is not a marker of resistance but rather may function as an indicator of rapamycin activity.

Topics: Animals; Antibiotics, Antineoplastic; Biomarkers, Tumor; Breast Neoplasms; Carcinoma, Neuroendocrine; Cell Line, Tumor; Class I Phosphatidylinositol 3-Kinases; Drug Resistance, Neoplasm; Everolimus; Female; Humans; Mice; Mice, Nude; Mutation; Phosphatidylinositol 3-Kinases; Phosphorylation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Sirolimus; TOR Serine-Threonine Kinases; Transplantation, Heterologous

Understanding the molecular pathogenesis of medullary thyroid carcinoma (MTC) is prerequisite to the design of targeted therapies for patients with advanced disease.. We studied by immunohistochemistry the phosphorylation status of proteins of the RAS/MEK/ERK and PI3K/AKT/mTOR pathways in 53 MTC tissues (18 hereditary, 35 sporadic), including 51 primary MTCs and 2 cases with only lymph node metastases (LNM). We also studied 21 autologous LNMs, matched to 21 primary MTCs. Staining was graded on a 0 to 4 scale (S score) based on the percentage of positive cells. We also studied the functional relevance of the mTOR pathway by measuring cell viability, motility, and tumorigenicity upon mTOR chemical blockade.. Phosphorylation of ribosomal protein S6 (pS6), a downstream target of mTOR, was evident (S ≥ 1) in 49 (96%) of 51 primary MTC samples. This was associated with activation of AKT (phospho-Ser473, S > 1) in 79% of cases studied. Activation of pS6 was also observed (S ≥ 1) in 7 (70%) of 10 hereditary C-cell hyperplasia specimens, possibly representing an early stage of C-cell transformation. It is noteworthy that 22 (96%) of 23 LNMs had a high pS6 positivity (S ≥ 3), which was increased compared with autologous matched primary MTCs (P = 0.024). Chemical mTOR blockade blunted viability (P < 0.01), motility (P < 0.01), and tumorigenicity (P < 0.01) of human MTC cells.. The AKT/mTOR pathway is activated in MTC, particularly, in LNMs. This pathway sustains malignant features of MTC cell models. These findings suggest that targeting mTOR might be efficacious in patients with advanced MTC.

Topics: Animals; Carcinoma; Carcinoma, Neuroendocrine; Cell Line, Tumor; Cell Movement; Cell Survival; DNA Mutational Analysis; Female; Humans; Lymphatic Metastasis; Mice; Mice, Inbred NOD; Mice, SCID; Mitogen-Activated Protein Kinases; Phosphorylation; Protein Processing, Post-Translational; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-ret; Ribosomal Protein S6 Kinases; Signal Transduction; Sirolimus; Statistics, Nonparametric; Thymus Hyperplasia; Thyroid Neoplasms; Tissue Array Analysis; TOR Serine-Threonine Kinases; Tumor Burden; Xenograft Model Antitumor Assays

Pancreatic neuroendocrine tumors (pNET), also known as islet cell tumors, exhibit a wide range of biologic behaviors ranging from long dormancy to rapid progression. Currently, there are few molecular biomarkers that can be used to predict recurrence/metastasis or response to therapy. This study examined the predictive and prognostic value of a single nucleotide polymorphism substituting an arginine (R) for glycine (G) in codon 388 of the FGFR4 transmembrane domain. We established the FGFR4 genotype of 71 patients with pNETs and correlated genotype with biologic behavior. We created an in vivo model of pNET with BON1 cells and transfected them with either FGFR4-G388 or FGFR4-R388 to determine the mechanism of action and to examine response to the mTOR inhibitor everolimus. We then validated the predictive results of experimental studies in a group of patients treated with everolimus. FGFR4-R388 is associated with more aggressive clinical behavior in patients with pNETs with a statistically significant higher risk of advanced tumor stage and liver metastasis. Using an orthotopic mouse xenograft model, we show that FGFR4-R388 promotes tumor progression by increasing intraperitoneal spread and metastatic growth within the liver. Unlike FGFR4-G388, FGFR4-R388 BON1 tumors exhibited diminished responsiveness to everolimus. Concordantly, there was a statistically significant reduction in response to everolimus in patients with FGFR4-R388. Our findings highlight the importance of the FGFR4 allele in pNET progression and identify a predictive marker of potential therapeutic importance in this disease.

Topics: Adult; Aged; Aged, 80 and over; Animals; Antineoplastic Agents; Carcinoma, Neuroendocrine; Cell Growth Processes; Cell Line, Tumor; Disease Progression; Everolimus; Female; Humans; Male; Mice; Mice, SCID; Middle Aged; Pancreatic Neoplasms; Polymorphism, Single Nucleotide; Receptor, Fibroblast Growth Factor, Type 4; Sirolimus; TOR Serine-Threonine Kinases; Xenograft Model Antitumor Assays; Young Adult

We hypothesized that autophagy inhibition would enhance the anticancer efficacy of ret protooncogene-targeted therapy in medullary thyroid cancer.. Medullary thyroid cancer-1.1 and TT cells were treated with sunitinib or sorafenib in the presence or absence of everolimus, trehalose, or small interfering RNA directed against autophagy protein 5.. Sunitinib and sorafenib each robustly induced light chain 3-II expression, indicating autophagy activation. Autophagy protein 5 silencing diminished the antiproliferative effects of sunitinib and sorafenib by 44% (P < .05) and 41% (P < .05), respectively, in medullary thyroid cancer-1.1 cells and by 43% (P < .01) and 39% (P < .05), respectively, in TT cells. In contrast, everolimus increased the antiproliferative effects of sunitinib and sorafenib by 24% (P < .01) and 27% (P < .01), respectively, in medullary thyroid cancer-1.1 cells and by 20% (P < .05) and 23% (P < .05), respectively, in TT cells. Trehalose increased the antiproliferative effects of sunitinib and sorafenib by 26% (P < .01) and 27% (P < .01), respectively, in medullary thyroid cancer-1.1 cells and by 28% (P < .05) and 29% (P < .05), respectively, in TT cells. Autophagy protein 5 silencing abrogated both everolimus- and trehalose-induced increases in tyrosine kinase inhibitor efficacy.. Loss (gain) of autophagy diminishes (improves) the efficacy of sunitinib and sorafenib. Our findings suggest that autophagic activation should be combined with targeted ret protooncogene therapy for patients with advanced medullary thyroid cancer.

Topics: Antineoplastic Agents; Autophagy; Benzenesulfonates; Benzimidazoles; Carcinoma, Neuroendocrine; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Synergism; Everolimus; Humans; Immunosuppressive Agents; Indoles; Niacinamide; Phenylurea Compounds; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Proto-Oncogene Proteins c-ret; Pyridines; Pyrroles; Sirolimus; Sorafenib; Sunitinib; Thyroid Neoplasms

Topics: Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Neuroendocrine; Everolimus; Female; Humans; Interferon alpha-2; Interferon-alpha; Malignant Carcinoid Syndrome; Middle Aged; Octreotide; Recombinant Proteins; Sirolimus

The mammalian target of rapamycin (mTOR) inhibitors, such as rapalogues, are a promising new tool for the treatment of metastatic gastroenteropancreatic endocrine tumors. However, their mechanisms of action remain to be established. We used two murine intestinal endocrine tumoral cell lines, STC-1 and GLUTag, to evaluate the antitumor effects of rapamycin in vitro and in vivo in a preclinical model of liver endocrine metastases. In vitro, rapamycin inhibited the proliferation of cells in the basal state and after stimulation by insulin-like growth factor-1. Simultaneously, p70S6 kinase and 4EBP1 phosphorylation was inhibited. In vivo, rapamycin substantially inhibited the intrahepatic growth of STC-1 cells, irrespectively of the timing of its administration and even when the treatment was administered after cell intrahepatic engraftment. In addition, treated animals had significantly prolonged survival (mean survival time: 47.7 days in treated animals versus 31.8 days in controls) and better clinical status. Rapamycin treatment was associated with a significant decrease in mitotic index and in intratumoral vascular density within STC-1 tumors. Furthermore, the antitumoral effect obtained after treatment with a combination of rapamycin and phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 was more significant than with rapamycin alone in both cell lines. Our results suggest that the antitumor efficacy of rapamycin in neuroendocrine tumors results from a combination of antiproliferative and antiangiogenic effects. Interestingly, a more potent antitumor efficiency could be obtained by simultaneously targeting several levels of the PI3K/mTOR pathway.

Topics: Animals; Antibiotics, Antineoplastic; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Neuroendocrine; Cell Line, Tumor; Cell Proliferation; Chromones; Intestinal Neoplasms; Mice; Morpholines; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Protein Kinase Inhibitors; Sirolimus; TOR Serine-Threonine Kinases

Topics: Angiogenesis Inhibitors; Animals; Antineoplastic Agents; Carcinoma, Neuroendocrine; Disease Models, Animal; Everolimus; Humans; Indoles; Mice; Pancreatic Neoplasms; Pyrroles; Sirolimus; Sunitinib; TOR Serine-Threonine Kinases

Because mammalian target of rapamycin (mTOR) may be involved in thyroid carcinogenesis, we investigated the expression and activation patterns of mTOR signaling proteins in thyroid carcinoma cells and tumors and their association with tumor histology and aggressiveness.. Tissue specimens from 50 patients with thyroid cancer were analyzed for eIF4E, a critical downstream target of the mTOR pathway, using immunohistochemistry. In addition, fresh-frozen samples from patients, and primary tumor cell cultures were analyzed for expression and activation of mTOR signaling proteins by Western blot. Moreover, pharmacologic studies with rapamycin were performed.. High expression of eIF4E was observed in medullary thyroid carcinomas (MTC) and in aggressive variants of papillary thyroid carcinomas (PTC) as compared with conventional PTC and follicular thyroid carcinomas (P < .0001). The level of eIF4E expression also correlated with tumor stage (P = .002). Using Western blot analysis, p-rpS6, p-4EBP1, 4EBP1, and eIF4E were detected at higher levels in aggressive PTC and MTC cells. Treatment of MTC cells with increasing concentrations of rapamycin resulted in significant cell death and in decreased cell growth associated with deactivation of the mTOR pathway.. mTOR signaling, which controls protein synthesis through regulation of translation initiation, is activated in aggressive PTC and MTC and represents a promising target for investigational therapies in these patients.

Topics: Adult; Blotting, Western; Carcinoma; Carcinoma, Neuroendocrine; Carcinoma, Papillary; Cell Death; Cell Line, Tumor; Eukaryotic Initiation Factor-4E; Female; Humans; Immunohistochemistry; Male; Middle Aged; Neoplasm Staging; Signal Transduction; Sirolimus; Thyroid Cancer, Papillary; Thyroid Neoplasms; TOR Serine-Threonine Kinases; Tumor Cells, Cultured

A 53-year-old female patient presented with cough and hoarseness for 3 years. Based on a biopsy of a bronchial tumor, a small cell neuroendocrine tumor of the lung was diagnosed and chemotherapy with etoposide and cisplatin was initiated. As the tumor progressed under chemotherapy, the bronchial biopsy was reevaluated and further biopsies of liver and adrenal metastases were obtained. The diagnosis was corrected, and an atypical neuroendocrine bronchial carcinoma was diagnosed. Under octreotide therapy, the patient remained stable for 1 year, when a discrete progress of the primary tumor in the lung was observed. Treatment with the mTOR (mammalian target of rapamycin) inhibitor everolimus was then initiated. Based on this case, the diagnostic criteria, prognostic factors and therapeutic options of neuroendocrine bronchial carcinomas are discussed.

Topics: Adrenal Gland Neoplasms; Adrenal Glands; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Bone Neoplasms; Calcitonin; Carcinoma, Bronchogenic; Carcinoma, Medullary; Carcinoma, Neuroendocrine; Cell Division; Female; Humans; Ki-67 Antigen; Liver; Liver Neoplasms; Lung; Lung Neoplasms; Middle Aged; Neoplasm Staging; Neoplasms, Multiple Primary; Octreotide; Paraneoplastic Syndromes; Sirolimus; Thyroid Gland; Thyroid Neoplasms