Department of Anatomy, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL, USA.
William Carey University, College of Osteopathic Medicine, Hattiesburg, MS, USA.
Oral Surg Oral Med Oral Pathol Oral Radiol. 2019 May;127(5):417-424. doi: 10.1016/j.oooo.2018.09.005. Epub 2018 Sep 26.
The purpose of this study was to assess the expression of the 3 major folate transporters-folate receptors (FRs), reduced folate carrier (RFC), and proton-coupled folate transporter (PCFT)-in oral squamous cell carcinoma (OSCC). We hypothesized that patterns of expression of folate transporters would be different in OSCC compared with normal oral epithelium.
We used immunohistochemistry to examine the expression of FR, RFC, and PCFT in 15 primary specimens collected from patients with OSCC, 2 human cadaveric samples of OSCC, and 12 normal human cadaveric oral tissues from a medical gross anatomy laboratory. Possible correlations between the expression of each folate transporter and patients' clinical data were determined.
All 3 folate transporters were highly expressed in normal oral epithelium. In contrast, OSCC samples generally demonstrated low expression of FR, RFC, and PCFT, with wide distribution in the invading cancer cells. There were no differences in folate transporter expression between OSCC samples collected from patients and from human cadavers. The lowest expression of FR and PCFT characterized less-differentiated tumors, and the lowest expression of RFC correlated with higher lymph node involvement.
Human oral cancer samples expressed decreased amounts of all 3 major folate transport proteins compared with controls from normal cadaveric oral tissues.
本研究旨在评估叶酸转运体（叶酸受体 [FR]、还原叶酸载体 [RFC]和质子偶联叶酸转运体 [PCFT]）在口腔鳞状细胞癌（OSCC）中的表达。我们假设 FR、RFC 和 PCFT 的表达模式在 OSCC 中与正常口腔上皮组织不同。
我们使用免疫组织化学方法检测了 15 例来自 OSCC 患者的原发性标本、2 例人类 OSCC 尸检标本和 12 例来自医学大体解剖实验室的正常人类尸检口腔组织中 FR、RFC 和 PCFT 的表达。确定了每种叶酸转运体的表达与患者临床数据之间的可能相关性。
所有 3 种叶酸转运体在正常口腔上皮组织中均高度表达。相比之下，OSCC 样本通常表现出 FR、RFC 和 PCFT 的低表达，在侵袭性癌细胞中广泛分布。来自患者和尸检的 OSCC 样本之间的叶酸转运体表达没有差异。FR 和 PCFT 的表达最低与分化程度较低的肿瘤有关，而 RFC 的表达最低与更高的淋巴结受累相关。
与来自正常尸检口腔组织的对照相比，人类口腔癌样本中所有 3 种主要叶酸转运蛋白的表达量均降低。
