Using titanium complexes to defeat cancer: the view from the shoulders of titans

When the first titanium complex with anticancer activity was identified in the 1970s, it was attractive, based on the presence of the dichloride unit in TiCl2Cp2 (Cp = η-C5H5)2, to assume its mode of biological action was closely aligned with cisplatin [cis-PtCl2(NH3)2]. Over the intervening 40 years however a far more complicated picture has arisen indicating multiple cellular mechanisms of cellular action can be triggered by titanium anti-cancer agents. This tutorial review aims to unpick the historical data and provide new researchers, without an explicit cancer biology background, a contemporary interpretation of both older and newer literature and to review the best techniques for attaining the identities of the biologically active titanium species and how these interact with the cancer cellular machinery

Cisplatin-Based Three Drugs Combination (NIP) as Induction and Adjuvant Treatment in Locally Advanced Non-small Cell Lung Cancer: Final Results

IntroductionThis phase III trial was conducted in non-small cell lung cancer patients with locally advanced stage II B (only T3N0) III A and III B (only T4 N0). Primary endpoint was 2-year survival; secondary were toxicity, disease-free survival, and overall survival.MethodsAfter three cycles of vinorelbine (N) 25 mg/m2 on days 1 and 5, ifosfamide/mesna (I) 3 g/m2 on day 1, cisplatin (P) (NIP), patients were treated by surgery and within 45 days were randomized to two additional cycles of NIP versus observation.ResultsMedian tumor diameter was 5.5 cm (1.2–10.6). Overall, 155 of 156 patients received chemotherapy: 133 (85%) men, median age: 59 years (35–75). Sixty-five percentage of patients were stage III A, 28% II B, and 7% III B. The study has been closed prematurely because of the low inclusion rate. After three cycles of induction in 143 assessable patients, 82 reported an objective response (57.3%) (95% CI: 48.8–65.6), with 3.5% complete response and 53.8% partial response. Relative dose intensity during neoadjuvant NIP (%) was 97, 98, and 98.5 for vinorelbine, ifosfamide/mesna, and cisplatin, respectively. Tolerance: G3 to 4 neutropenia in 3% of patients and G3 to 4 anemia in 4%; nonhematological toxicities included G3 nausea/vomiting in 11%, G3 anorexia and G3 to 4 infection in 6.5%, G3 asthenia in 10% and G3 to 4 alopecia in 25.5%. After a median of 32 days after NIP, 107 patients (69%) underwent operation with complete resection (R0) in 74% (79 of 107 patients). Downstaging (N2 to N0) after surgery was 29%. Operative mortality rate was 2.8%. Twenty-one days (median) after surgery, 79 patients were randomized to adjuvant NIP (47%) or control (53%). Tolerance of adjuvant NIP: 12.5% G3 to 4 nausea/vomiting, 19% G3 alopecia, 6% G3 infection, and G3 asthenia. Overall median survival 32.3 versus 31.8 months in the observation and NIP arms, respectively.ConclusionsNIP allows 74% of R0 with no surgery delay. The few number of randomized patients did not allow to conclude on the efficacy of adjuvant chemotherapy

Foreign Proteostasis Hub Hsp90 Promotes Network Evolution in Saccharomyces cerevisiae

Biological processes in living cells are often carried out by gene networks in which signals and reactions are integrated at network hubs, which play fundamental roles for maintaining the cell physiology through interacting highly with other genes. Network hubs are responsivle for collecting signals from the upstream genes and then tune the cellular outputs in correspondent to the environmental cues. Hub genes are known to be evolutionary conserved and even slight perturbations of the sequences can lead to deleterious cell growth. Despite of the functional constraint, the sequences of the hub genes still change along the time. It is unclear to what extent the natural sequence variation actually contributes to functional divergence and to what extent network hubs are evolvable. Furthermore, to our knowledge no study has ever addressed how these alterations impact long-term evolution. We investigated these questions using a protein homeostasis central hub, heat shock protein (Hsp90) wich is essential under the normal condition for maintaining the normal cell growth. When native Hsp90 in Saccharomyces cerevisiae cells was replaced by the ortholog from hypersaline-tolerant Yarrowia lipolytica that diverged from S. cerevisiae about 270 million years ago, the cells exhibited improved growth in hypersaline environments but compromised growth in others, indicating functional divergence in Hsp90 between the two yeasts. Laboratory evolution shows that evolved Y. lipolytica-HSP90-carrying S. cerevisiae cells exhibit a wider range of phenotypic variation than cells carrying native HSC82. Identified beneficial mutations are involved in multiple pathways and are often pleiotropic. Our results show that cells adapt to a heterologous Hsp90 by modifying different sub-networks, facilitating the evolution of phenotypic diversity inaccessible to wild-type cells.Acknowledgements i Abstract iii Introduction iv List of Figures ix List of Tables xii Chapter 1: Y. lipolytica Hsp90 and its interactome are functionally diverged from the S. cerevisiae counterparts 1 Materials and Methods 2 Hsp90 physical interactome analysis 2 Construction of the HSP90 replacement lines 2 Cell fitness assays 5 Western blotting for measuring the abundance of Hsp90 6 V-src kinase assay 7 Results 8 Replacing HSP90 with the Yarrowia lipolytica ortholog increases salt tolerance of Saccharomyces cerevisiae cells 8 19% of the S. cerevisiae Hsp90 physical interactors are missing in Y. lipolytica 16 Chapter 2: Experimental evolution of the Y. lipolytica-HSP90-hosting S. cerevisiae cells and their phenotypes 20 Materials and Methods 21 Experimental evolution 21 Flow cytometry of DNA content 21 Hsp104 aggregation assay 22 Cell morphology assay 23 Results 23 Adaptation to the foreign Hsp90 in laboratory evolution experiments 23 Fitness improvement in the evolved clones is specific to Ylip-Hsp90 30 Individual evolved Ylip-HSP90 clones improve their cell phsiologies to varying degrees 33 Chapter 3: Ylip-HSP90 evolved clones exhibit high phenotypic diversity which can be recapitulated by single mutations 37 Materials and Methods 38 Cell fitness assays 38 Hierarchical clustering and PCA analysis 39 Calculation of Pearson Correlation distances 39 Whole genome sequencing analysis 40 F1 segregant analysis 41 Gene ontology enrichment and network analysis 42 CRISPR-Cas9-directed mutant reconstitution 43 Data access 44 Results 48 Independent Ylip-HSP90 clones evolved through different adaptive trajectories 48 Mutations in evolved Ylip-HSP90 clones are associated with various Hsp90-related functions 56 Segregant analysis identifies beneficial mutations with strong fitness effects 95 Individual mutations exert condition-specific effects 98 Chapter 4: Impact of hub mutations and its implication in organismal evolution 104 Genotype and phenotype 105 Hub and evolvability 105 A compromised hub leads to network evolution 107 Reference 11