Herein we propose a new concept to control sequence for vinyl polymers. A tertiary alkyl methacrylate monomer carrying both adamantyl and isopropyl groups (IPAMA) is very unique to allow control of single unit addition with an alkyl halide initiator for metal-catalyzed living radical polymerization due to the exceptional bulkiness. After control of the single unit addition, the bulkiness can be removed via acidolysis to further convert into the ester pendant with less bulky and nontertiary alcohol. The resultant adduct can be used as an initiator for the next single unit addition of IPAMA and the terminal ester can be selectively hydrolyzed followed by esterification similar to the first process. Namely, the cycle consisting of “radical addition of IPAMA”, “acidolysis of the IPAMA side group”, and “esterification of resultant carboxylic acid” can be repeated to construct sequence well-defined poly­(oligo-)­methacrylates. In this letter, results of the cycle and the iterative process with the special methacrylate monomer are actually demonstrated as well as the scope of applicable alcohols for the esterification process toward sequence control with functional units.

In this work, we provide a facile methodology to synthesize AB alternating-rich copolymers made of methacrylic acid (MAA) and alkyl acrylamide units. An extremely bulky tert-alkyl methacrylate carrying ethyl and fenchol substituents (EFMA) was newly designed as a special monomer that is inactive for homopolymerization but active for copolymerization in radical polymerization. Indeed, EFMA showed a unique radical copolymerization behavior to the bulkiness, which was quite different from a general methacrylate (i.e., methyl methacrylate). The copolymerization of EFMA with an electron-deficient acrylate carrying a N-hydroxysuccinimide substituent followed by postreactions (i.e., acidolysis and aminolysis) for both units afforded an alternating-rich copolymer of MAA and alkyl acrylamide units. The sequence was characterized by 13C NMR analyses in comparison with the statistical copolymers and homopolymers. The reactivity ratio values also supported the process of alternating copolymerization. The thus-obtained alternating-rich copolymers of MAA with isopropyl acrylamide or octadecyl acrylamide showed sequence-driven solubilities and thermal response properties.

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Phosphatidylinositol 3-kinase (PI3K) signalling plays a pivotal role in intracellular signal transduction pathways involved in cell growth, cellular transformation, and tumourigenesis. PI3K is overexpressed in many human cancers, including endometrial carcinomas, one of the most common female genital tract malignancies. Here, we used small interfering RNA (siRNA) targeted to PI3K p110-beta to determine whether inhibition of the beta isoform could be a potential therapeutic target for endometrial carcinoma. In this study, treatment of HEC-1B endometrial cancer cells with PI3K p110-beta-specific siRNA resulted in increased apoptosis and decreased tumour cell proliferation. Depletion of PI3K p110-beta decreased the protein levels of AKT1, AKT2, pAKT, and mTOR-downstream targets of PI3K. Knock-down of PI3K p110-beta by siRNA also induced decreased expression of cyclin E and Bcl-2, suggesting that PI3K p110-beta stimulates tumour growth, at least in part by regulating cyclin E and Bcl-2. Thus, our results indicate that siRNA-mediated gene silencing of PI3K p110-beta may be a useful therapeutic strategy for endometrial cancers overexpressing PI3K p110-beta.