Qiu Wanglong, Tong Guo-Xia, Turk Andrew T, Close Lanny G, Caruana Salvatore M, Su Gloria H
The Department of Pathology, Columbia University Medical Center, 1130 Saint Nicholas Avenue, ICRC 10-04, New York, NY 10032, USA ; Herbert Irving Comprehensive Cancer Center, Columbia University Medical Center, 1130 Saint Nicholas Avenue, ICRC 10-04, New York, NY 10032, USA.
The Department of Pathology, Columbia University Medical Center, 1130 Saint Nicholas Avenue, ICRC 10-04, New York, NY 10032, USA.
Biomed Res Int. 2014;2014:810487. doi: 10.1155/2014/810487. Epub 2014 Jan 8.
Salivary duct carcinoma (SDC) is an aggressive malignant tumor with a high mortality, which resembles high-grade breast ductal carcinoma in morphology. The parotid gland is the most common location. Its molecular genetic characteristics remain largely unknown. We have previously reported high incidence of PIK3CA somatic mutations in head and neck squamous cell carcinoma, particularly in pharyngeal cancers. Here we examined the PIK3CA gene expression status and hotspot mutations in six cases of SDC by immunohistochemistry and genomic DNA sequencing. Immunohistochemistry showed that PIK3CA expression was elevated in all six patients with SDC. By DNA sequencing, two hotspot mutations of the PIK3CA gene, E545K (exon 9) and H1047R (exon 20), were identified in two of the six cases. Our results support that oncogenic PIK3CA is upregulated and frequently mutated in human SDC, adding evidence that PIK3CA oncogenic pathway is critical in the tumorigenesis of SDC, and may be a plausible drug target for this rare disease.
涎腺导管癌（SDC）是一种侵袭性恶性肿瘤，死亡率高，形态学上类似于高级别乳腺导管癌。腮腺是最常见的发病部位。其分子遗传学特征在很大程度上仍不清楚。我们之前报道过PIK3CA体细胞突变在头颈部鳞状细胞癌，尤其是咽癌中的高发生率。在此，我们通过免疫组织化学和基因组DNA测序检测了6例涎腺导管癌患者的PIK3CA基因表达状态和热点突变。免疫组织化学显示，所有6例涎腺导管癌患者的PIK3CA表达均升高。通过DNA测序，在6例中的2例中鉴定出PIK3CA基因的两个热点突变，E545K（第9外显子）和H1047R（第20外显子）。我们的结果支持致癌性PIK3CA在人类涎腺导管癌中上调且频繁发生突变，这进一步证明PIK3CA致癌途径在涎腺导管癌的肿瘤发生中至关重要，并且可能是这种罕见疾病的一个合理的药物靶点。
