Toru Sugiyama

Neoadjuvant Chemotherapy Using Platinum-Based Regimens for Stage Ib2-II Squamous Cell Carcinoma and Non-Squamous Cell Carcinoma of the Cervix

The methods used for treating stage Ib2-IIb cervical cancers, with a bulky mass, differ between Japan and Western countries. In Western countries, concurrent chemoradiation (CCRT) has been recommended as a standard therapy for such tumors based on the results of multiple large-scale randomized trials and meta-analyses (Morris et al., 1999; Rose et al., 1999; Whitney et al., 1999; Pearcey et al., 2002; Eifel et al. 2004; Green et al. 2001; Lukka et al., 2002). In Japan, Korea, Italy and some other countries, the neoadjuvant chemotherapy (NAC) approach has been extensively introduced to clinical practice (Sugiyama et al., 1999). NAC is considered to be clinically significant in 2 respects: it is expected to improve the radicality and safety of surgery by reducing tumor size; and it is expected to exert systemic effects, i.e., effects on lymph node occult micrometastases, etc. A disadvantage of NAC is delayed initiation of the primary treatment, suggesting the necessity of completing NAC as an auxiliary therapy within a short period of time. Therefore, we may find that NAC is valuable if it can exert efficacy rapidly with high platinum dose intensity (DI), assuring that subsequent primary surgical therapy can be performed as soon as possible. At our facility, a platinum-based regimen has been used for NAC in patients with cervical cancer. Herein, we review the efficacy and safety data on NAC for squamous cell carcinoma of the uterine cervix. We previously reported our interim data and now present the results of an ongoing pilot study on the efficacy and safety of NAC for non-squamous cell carcinoma of the uterine cervix.

Recent developments for introducing a hexafluoroisopropanol unit into the Vitamin D side chain

Among numerous studies on synthetic approaches to and the biological activities of vitamin D analogues, we herein focused on falecalcitriol, an analogue of calcitriol (1α,25-dihydroxyvitamin D3), in which a 26,26,26,27,27,27-hexafluoroisopropanol unit has been introduced into the side chain. Falecalcitriol was designed to escape from the metabolism of CYP24A1 and has been used as a drug to treat secondary hyperparathyroidism since 2001. Its metabolite, the 23-hydroxy form, retains biological activity and resistants to further metabolism. Recent developments in synthetic methodologies for introducing the hexafluoroisopropanol unit into the vitamin D CD-ring side chain were described herein.

Concise Synthesis of 23-Hydroxylated Vitamin D3 Metabolites

Three 23-hydroxylated vitamin D3 derivatives, which are metabolites of 25-hydroxyvitamin D3 produced by CYP24A1 and a related diastereomer, were efficiently synthesized. Each C23 hydroxy unit was constructed by the Claisen condensation reaction with ethyl acetate or the Grignard reaction with 2-methylallymagnesium chloride. Stereochemistry at the C23 position was determined by a modified Moshers method. The triene structures were constructed by the Wittig-Horner reaction utilizing the A-ring phosphine oxide moiety.

PNA monomers fully compatible with standard Fmoc-based solid-phase synthesis of pseudocomplementary PNA

Here we report the synthesis of new PNA monomers for pseudocomplementary PNA (pcPNA) that are fully compatible with standard Fmoc chemistry. The thiocarbonyl group of the 2-thiouracil (sU) monomer was protected with the 4-methoxy-2-methybenzyl group (MMPM), while the exocyclic amino groups of diaminopurine (D) were protected with Boc groups. The newly synthesized monomers were incorporated into a 10-mer PNA oligomer using standard Fmoc chemistry for solid-phase synthesis. Oligomerization proceeded smoothly and the HPLC and MALDI-TOF MS analyses indicated that there was no remaining MMPM on the sU nucleobase. The new PNA monomers reported here would facilitate a wide range of applications, such as antigene PNAs and DNA nanotechnologies.

Peptide Nucleic Acid with a Lysine Side Chain at the β-Position: Synthesis and Application for DNA Cleavage

This paper reports the synthesis of new β-Lys peptide nucleic acid (PNA) monomers and their incorporation into a 10-residue PNA sequence. PNA containing β-Lys PNA units formed a stable hybrid duplex with DNA. However, incorporation of β-Lys PNA units caused destabilization of PNA-DNA duplexes to some extent. Electrostatic attractions between β-PNA and DNA could reduce this destabilization effect. Subsequently, bipyridine-conjugated β-Lys PNA was prepared and exhibited sequence selective cleavage of DNA. Based on the structures of the cleavage products and molecular modeling, we reasoned that bipyridine moiety locates within the minor groove of the PNA-DNA duplexes. The lysine side chain of β-PNA is a versatile handle for attaching various functional molecules.