Study on the relationship between PTHrP gene expression and differentiation of oral squamous cell carcinoma

我们发现甲状旁腺激素相关蛋白PTHrP的免疫染色，氨基酸1-34与口腔鳞状细胞癌OSCC的角化和恶性的组织学分级相关（摘要，国际口腔颌面外科协会。外科医生1997，京都）。目的：探讨PTHrPmRNA表达与PTHrP 1-34免疫组化染色及角化的关系。本研究使用了33例OSCC患者（11例女性和22例男性）的活检标本和4例正常粘膜标本。在5 μm厚的石蜡切片上进行先前描述的用多克隆1-34抗体的免疫组织化学染色（LSAB方法）和非同位素原位杂交。我们使用地高辛标记的寡核苷酸探针，其与编码PTHrP 6-16氨基酸序列的人PTHrP mRNA互补。切片用Mayer苏木精复染。PTHrP mRNA阳性率为91%（30/33）。所有标本经免疫组化染色分为两组，一组为轻度染色，另一组为强染色。虽然强染色组PTHrP mRNA阳性率（100%，13/13）高于弱染色组（85%，17/20），但通过mRNA的表达很难区分两组，提示PTHrP的转录可能对口腔癌的角化或分化没有太大影响。PTHrP的翻译后加工可能在这一现象中起主要作用。需要进一步研究来阐明这一问题。部分由日本教育科学和文化部的补助金（第10470443号）资助。

We found that immunostain of parathyroid hormone related protein, PTHrP, amino acids 1-34 correlated with a histological grading for keratinization and malignancy of oral squamous cell carcinoma, OSCC (abstract, the Int.Association of Oral ＆ Maxillofac. Surgeons. 1997, Kyoto). The purpose was to determine whether the expressin of the mRNA of PTHrP is related to the immunohistochemical stains of PTHrP 1-34 and keratinization. Biopsy specimens from 33 patients, 11 females and 22 males, with OSCC and 4 normal mucosal specimens were used of this study. A previously described method of immunohistochemical staining (LSAB method) with polyclonal 1-34 antibodies and non-isotopic in situ hybridization were performed on 5 μm thickness paraffin sections. We used digoxigenin labeled oligonucleotide probe which was complement to the human PTHrP mRNA coding for the amino acid sequence PTHrP 6-16. The sections were counterstained with Mayer's hematoxylin. Positive signals of PTHrP mRNA were present in 30/33 (91%) specimens. All specimens were classified in two groups, one showed slight stains and another showed intense staining by the immunohistochemical investigation. Although the percentage(100%, 13/13) of positive signals of the mRNA in the intense stain group is higher than that(85%, 17/20) in the weak stain group, it was difficult to distinguish two groups by expression of mRNA.The results suggest that transcription of PTHrP might not affect much to keratinication or differentiation of oral cancer. Post translational processing of PTHrP may take a major role for this phenomenon. Additional study is required to elucidate this issue. Partially supported by a Grant-in-aid (No.10470443) from the Ministry of Education Science, and Culture of Japan.