Altered p16(INK4) and RB1 Expressions Are Associated with Poor Prognosis in Patients with Nonsmall Cell Lung Cancer.

p16(INK4) and RB1 are two potent cell cycle regulators to control the G1/S transition by interacting with CDK4/6, E2F, and D-type cyclins, respectively. Depending on the tumour type, genetic alterations resulting in the functional inactivation have frequently been reported in both genes. By contrast, much less is known regarding the overexpression of these proteins in the tumor cells. In this study, expressions of p16(INK4) RB1, and CDKN2A copy number variances (CNV) in the tumor cells were assessed by immunohistochemistry and fluorescence in situ hybridization (FISH), respectively, in 73 nonsmall cell lung cancer (NSCLC) with known 5-year survivals. The histologic type (P = 0.01), p16(INK4) (P = 0.004), and RB1 (P < 0.001) were predictive of survivals. The CDKN2A CNV (P < 0.05) was also significant when compared to those cases without CNV. Therefore, among the molecular genetic prognostic factors, expressions of RB1 and p16(INK4) in the tumor cells were the most strongly predictive of adverse outcomes in stage I and II nonsquamous NSCLC.

Creating diverse target-binding surfaces on FKBP12: synthesis and evaluation of a rapamycin analogue library.

FK506 and rapamycin are immunosuppressive drugs with a unique mode of action. Prior to binding to their protein targets, these drugs form a complex with an endogenous chaperone FK506-binding protein 12 (FKBP12). The resulting composite FK506-FKBP and rapamycin-FKBP binding surfaces recognize the relatively flat target surfaces of calcineurin and mTOR, respectively, with high affinity and specificity. To test whether this mode of action may be generalized to inhibit other protein targets, especially those that are challenging to inhibit by conventional small molecules, we have developed a parallel synthesis method to generate a 200-member library of bifunctional cyclic peptides as FK506 and rapamycin analogues, which were referred to as "rapalogs". Each rapalog consists of a common FKBP-binding moiety and a variable effector domain. The rapalogs were tested for binding to FKBP12 by a fluorescence polarization competition assay. Our results show that FKBP12 binds to most of the rapalogs with high affinity (K(I) values in the nanomolar to low micromolar range), creating a large repertoire of composite surfaces for potential recognition of macromolecular targets such as proteins.

A phase I study of pivaloyloxymethyl butyrate, a prodrug of the differentiating agent butyric acid, in patients with advanced solid malignancies.

Pivaloyloxymethyl butyrate (AN-9), an acyloxyalkyl ester prodrug of butyric acid (BA), has demonstrated greater potency than BA at inducing malignant cell differentiation and tumor growth inhibition and has demonstrated more favorable toxicological, pharmacological, and pharmaceutical properties than BA in preclinical studies. The principal objective of this study was to determine the feasibility of administering AN-9 as a 6-h i.v. infusion daily for 5 days every 3 weeks in patients with advanced solid malignancies. The study also sought to determine the principal toxicities and maximum tolerated dose of AN-9 on this intermittent schedule, as well as the effects of AN-9 on fetal hemoglobin production, a parameter indicative of RBC differentiation. None of the 28 patients treated with 85 total courses of AN-9 at dosages ranging from 0.047 to 3.3 g/m(2)/day every 3 weeks experienced dose limiting toxicity. Mild to moderate nausea, vomiting, hepatic transaminase elevation, hyperglycemia, fever, fatigue, anorexia, injection site reaction, diarrhea, and visual complaints were observed. Dose escalation of AN-9 was limited by the maximum feasible volume of its intralipid formulation vehicle that could be administered safely on this schedule, resulting in a maximum deliverable dose of 3.3 g/m(2)/day. There was no consistent increase in fetal hemoglobin with AN-9 treatment. A partial response was observed in a previously untreated patient with metastatic non-small cell lung cancer. Additional disease-directed clinical evaluations of AN-9 are necessary to establish the breadth of its antitumor activity and to assess its role as an effective differentiating agent.