[Clinicopathological Evaluation of Preoperative Chemotherapy Containing S-1 as a Treatment for Patients with Oral Squamous Cell Carcinoma during Waiting Time for Surgery].

BACKGROUND: In our department, patients with oral squamous cell carcinoma(OSCC)received preoperative chemotherapy containing S-1 to prevent the growth and dissemination of tumors during the waiting time before definitive surgery. We retrospectively evaluated the usefulness of this treatment. PATIENTS AND METHODS: One hundred and five patients comprising stages T1(26), T2(64), T3(7), and T4(8 cases)were enrolled in this study from July 2001 to June 2013. In principle, patients were administered S-1(80mg/m / 2/day, days 1-14)and followed by a drug holiday(days 15-21), continuing until 1 week before surgery. RESULTS: The median administration period was 14 days(256 days). Ninety-eight patients underwent definitive surgery, but 7 patients who revealed clinical CR underwent only biopsy and showed histological CR. The histological responses of all patients were CR(24), PR(22), and NC(59), and the response rate was 43.8%. Almost all adverse effects were Grade 1 or 2, except 1 case of neutropenia(Grade 3)and 1 case of urticaria(Grade 3). The 5-year overall survival rates were 86.7% in all cases, 95.3% in CR/PR cases, and 79.7% in NC cases. CONCLUSION: Preoperative S-1 administration during the waiting time was a safe and very effective method and was considered beneficial for patients with OSCC.

Entry of Oncolytic Herpes Simplex Virus into Human Squamous Cell Carcinoma Cells by Ultrasound.

Low-intensity ultrasound is a useful method to introduce materials into cells due to the transient formation of micropores, called sonoporations, on the cell membrane. Whether oncolytic herpes simplex virus type 1 (HSV-1) can be introduced into oral squamous cell carcinoma (SCC) cells through membrane pores remains undetermined. Human SCC cell line SAS and oncolytic HSV-1 RH2, which was deficient in the 134.5 gene and fusogenic, were used. Cells were exposed to ultrasound in the presence or absence of microbubbles. The increase of virus entry was estimated by plaque numbers. Viral infection was hardly established without the adsorption step, but plaque number was increased by the exposure of HSV-1-inoculated cells to ultrasound. Plaque number was also increased even if SAS cells were exposed to ultrasound and inoculated with RH2 without the adsorption step. This effect was abolished when the interval from ultrasound exposure to virus inoculation was prolonged. Scanning electron microscopy revealed depressed spots on the cell surface after exposure to ultrasound. These results suggest that oncolytic HSV-1 RH2 can be introduced into SAS cells through ultrasound-mediated pores of the cell membrane that are resealed after an interval.

Sequence of a fusogenic herpes simplex virus, RH2, for oncolytic virotherapy.

RH2 is a novel oncolytic herpes simplex virus type 1 (HSV-1) produced by simultaneous infection with neurovirulent γ134.5 gene-deficient HSV-1 R849 derived from strain F and the spontaneously occurring, fusogenic HSV-1 HF in cell culture. The genome of RH2 was studied using Genome Sequencer FLX. RH2 comprised 149 64 bp and it was shown that the lacZ gene was inserted into the γ134.5 gene of R849. Comparison of ORFs revealed that RH2 had 100 % identity with strain F in 21/58 unique long (UL) genes (36.2%) and 1/13 unique short (US) genes (7.7%). RH2 had 100% amino acid identity with HF10 in 24/58 UL genes (41.4%) and 9/13 US genes (69.2%). Twelve genes, including UL27 (gB), US4 (gG) and UL6 (gD), had amino acid changes unique to RH2. Amino acid changes in gB occurred at positions 459 (T→A) and 817 (L→P). Other unique features were the amino acids missing in UL36 (VP1/2) and UL46 (VP11/12). Thus, RH2 is an HF10-based vector preserving the fusogenic amino acid changes of gB but lacking the γ134.5 gene. RH2 is expected to be a version of HF10 useful for the treatment of brain tumours as well as oral squamous cell carcinoma. Spontaneously occurring HSV-1 mutants may also be useful clinically, as their genome sequences can easily be determined by this genome sequencing system.