title: PITX1 is a novel predictor of the response to chemotherapy in head and neck squamous cell carcinoma.
abstract: The pituitary homeobox 1 (PITX1) protein is essential for developmental processes in humans. Previously, PITX1 was identified as a possible tumor suppressor gene in various types of human carcinoma. However, the association between PITX1 and human head and neck squamous cell carcinoma (HNSCC) remains to be elucidated. Immunohistochemical analysis was performed to examine the expression levels of PITX1 in 47 cases of HNSCC, and in 4 control cases. The expression of p53 was also examined in these cases. The labeling indices (LIs) were calculated, and the correlations between clinical factors (chemosensitivity, prognosis and the degree of differentiation) and the LIs were assessed. The PITX1 LI in HNSCC was 27.4±14.5%, which was significantly lower compared with the LIs of the control samples: 76.9±6.97% (P<0.05). Additionally, the PITX1 LIs were 39.9±6.2, 26.9±16.9 and 24.2±11.8% in the complete response (CR), partial response (PR), stable disease or progressive disease (SD/PD) groups, respectively. The PITX1 LI in the CR group revealed the highest result between the all groups, and it was significantly greater compared with that in the SD/PD group (P<0.01). The p53 LIs were 24.5±19.9, 25.7±16.9 and 19.8±13.8 in the CR, PR and SD/PD groups, respectively (P>0.05). Neither the PITX1 nor the p53 LIs were a statistically significant indicator of the prognosis. PITX1 is a candidate tumor suppressor gene and a possible predictive biomarker of chemosensitivity of human HNSCC.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan; Division of Pathological Biochemistry, Department of Biomedical Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Takenobu
authors.affiliation: Division of Pathological Biochemistry, Department of Biomedical Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan; Chromosome Engineering Research Center, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Osaki
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Fujiwara
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fukuhara
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Hiroya
authors.initials: H
authors.lastname: Kitano
authors.affiliation: Chromosome Engineering Research Center, Tottori University, Yonago, Tottori 683-8503, Japan; Division of Molecular Genetics and Biofunction, Graduate School of Medical Science; Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kugoh
authors.affiliation: Division of Pathological Biochemistry, Department of Biomedical Sciences, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan; Chromosome Engineering Research Center, Tottori University, Yonago, Tottori 683-8503, Japan.
authors.forename: Futoshi
authors.initials: F
authors.lastname: Okada
keywords: PITX1; biomarker; chemosensitivity; head and neck squamous cell carcinoma; tumor suppressor gene