sirolimus and lonafarnib

Cancer is a complex disease characterized by a multitude of molecular and genetic abnormalities affecting cell proliferation and differentiation, apoptosis, and mobility (invasion). Each of these alterations represents a potential target for the development of targeted therapy. These new therapies inhibit cell growth and are said to be "cytostatic" in contrast with conventional "cytotoxic" chemotherapy. As a result of a better understanding of the molecular biology of bladder cancers, various signalling pathways involved in both carcinogenesis and tumour progression have been defined, and some of the key molecules in these pathways have been isolated and can be used as prognostic markers and as potential therapeutic targets. Locally advanced, and/or metastatic bladder cancer, is characterized by mutations of the p53 and retinoblastoma (Rb) genes, regulators of the cell cycle, which interact with the Ras-mitogen activated protein kinase (MPAK) transduction pathway. Overexpression of tyrosine kinase receptors, including EGFR, VEFGR and HER2/neu, is correlated with tumour progression and activation of the phosphatidyl-inositol-3 kinase (PI-3K) pathway is involved in tumour invasion and inhibition of apoptosis. Due to their molecular heterogeneity, optimal targeted therapy of bladder cancers will require the combined use of several molecules. Modulation of signalling pathways by these new molecules can restore chemosensitivity to cytotoxic drugs, which can then be associated with targeted therapy.

Topics: Angiogenesis Inhibitors; Antibiotics, Antineoplastic; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Bevacizumab; Disease Progression; Erlotinib Hydrochloride; Gefitinib; Genetic Therapy; Humans; Immunosuppressive Agents; Mutation; Piperidines; Protein Kinase Inhibitors; Pyridines; Quinazolines; Randomized Controlled Trials as Topic; Signal Transduction; Sirolimus; Targeted Gene Repair; Trastuzumab; Urinary Bladder Neoplasms

Topics: Antineoplastic Agents; Benzamides; Brain Neoplasms; Drug Delivery Systems; Drug Design; Drug Resistance, Neoplasm; Drug Therapy, Combination; ErbB Receptors; Erlotinib Hydrochloride; Gefitinib; Glioma; Humans; Imatinib Mesylate; Intracellular Signaling Peptides and Proteins; Mitogen-Activated Protein Kinases; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Piperazines; Piperidines; Protein Kinases; Protein-Tyrosine Kinases; Pyridines; Pyrimidines; Quinazolines; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases

Clinical trials have demonstrated that lonafarnib, a farnesyltransferase inhibitor, extends the lifespan in patients afflicted by Hutchinson-Gilford progeria syndrome, a devastating condition that accelerates many characteristics of aging and results in premature death due to cardiovascular sequelae. The US Food and Drug Administration approved Zokinvy (lonafarnib) in November 2020 for treating these patients, yet a detailed examination of drug-associated effects on cardiovascular structure, properties, and function has remained wanting. In this paper, we report encouraging outcomes of daily post-weaning treatment with lonafarnib on the composition and biomechanical phenotype of elastic and muscular arteries as well as associated cardiac function in a well-accepted mouse model of progeria that exhibits severe perimorbid cardiovascular disease. Lonafarnib resulted in 100% survival of the treated progeria mice to the study end-point (time of 50% survival of untreated mice), with associated improvements in arterial structure and function working together to significantly reduce pulse wave velocity and improve left ventricular diastolic function. By contrast, neither treatment with the mTOR inhibitor rapamycin alone nor dual treatment with lonafarnib plus rapamycin improved outcomes over that achieved with lonafarnib monotherapy.

Topics: Animals; Lamin Type A; Mice; Piperidines; Progeria; Pulse Wave Analysis; Sirolimus

The AKT-mTOR pathway harbors several known and putative oncogenes and tumor suppressors. In a phenotypic screen for lymphomagenesis, we tested candidate genes acting upstream of and downstream from mTOR in vivo. We find that Rheb, a proximal activator of mTORC1, can produce rapid development of aggressive and drug-resistant lymphomas. Rheb causes mTORC1-dependent effects on apoptosis, senescence, and treatment responses that resemble those of Akt. Moreover, Rheb activity toward mTORC1 requires farnesylation and is readily blocked by a pharmacological inhibitor of farnesyltransferase (FTI). In Pten-deficient tumor cells, inhibition of Rheb by FTI is responsible for the drug's anti-tumor effects, such that a farnesylation-independent mutant of Rheb renders these tumors resistant to FTI therapy. Notably, RHEB is highly expressed in some human lymphomas, resulting in mTORC1 activation and increased sensitivity to rapamycin and FTI. Downstream from mTOR, we examined translation initiation factors that have been implicated in transformation in vitro. Of these, only eIF4E was able to enhance lymphomagenesis in vivo. In summary, the Rheb GTPase is an oncogenic activity upstream of mTORC1 and eIF4E and a direct therapeutic target of farnesyltransferase inhibitors in cancer.

Topics: Animals; Antibiotics, Antineoplastic; Blotting, Western; Cell Transformation, Neoplastic; Cells, Cultured; Cellular Senescence; Doxorubicin; Eukaryotic Initiation Factor-4E; Farnesyltranstransferase; Female; Fibroblasts; Gene Dosage; Humans; Immunophenotyping; Immunosuppressive Agents; Lymphoma; Mechanistic Target of Rapamycin Complex 1; Mice; Mice, Inbred C57BL; Mice, Knockout; Monomeric GTP-Binding Proteins; Multiprotein Complexes; Neuropeptides; Phosphorylation; Piperidines; Proteins; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-myc; PTEN Phosphohydrolase; Pyridines; Ras Homolog Enriched in Brain Protein; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Transcription Factors; Tumor Suppressor Protein p53