sirolimus and Carcinoma--Bronchogenic

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

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