Kong Darren Chyi-Hsiang, Chew Kenneth Yee Choy, Tan Eng Lai, Khoo Suan Phaik
International Medical University (IMU), Bukit Jalil, 57000 Kuala Lumpur, Malaysia.
Monash University Malaysia, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia.
Cancer Cell Int. 2014 Nov 18;14:65. doi: 10.1186/1475-2867-14-65. eCollection 2014.
Epiregulin (EPR) is a novel member of the epidermal growth factor (EGF) family. It has been shown to promote wound healing in oral epithelium, enhance proliferation of other epithelial tissues, and is involved in several epithelial-related malignancies such as colorectal, lung, and bladder carcinoma. More recently, EPR transcripts were found to be high in a study on archival oral squamous cell carcinoma (OSCC) specimens. This implies that EPR may be responsible for the progression of OSCC. The aim of this was to elucidate the effects of EPR on (i) cell morphological changes, (ii) cell proliferation and (iii) receptor expression of the H-series OSCC cell lines.
The clinicopathological origin and the expression of the epidermal growth factor receptor (EGFR) and ErbB4 receptors of the H-series cell lines were initially characterised. Based on these parameters, two of the H-series cell lines, namely H103 and H357 were selected for downstream experiments. The cell lines were treated with 1 ng/ml, 10 ng/ml, and 20 ng/ml of EPR for 24 and 48 hours in all subsequent experiments. Untreated cells acted as the control which was used for comparison with each treated group. The cell morphological changes, cell proliferation and receptor expression of the OSCC cell lines were evaluated using phase contrast microscopy, 5-bromo-2'-deoxy-uridine (BrdU) assays and flow cytometry respectively. The results were compared and analysed using the student t-test.
There were no appreciable morphological changes in the cells regardless of the dose of EPR tested nor between the different timelines. There were no significant changes in cell proliferation after EPR treatment. As for the effect of EPR on receptor expression, 20 ng/ml of EPR significantly reduced the density of EGFR expression (p value = 0.049) in the H103 cell line after the 24-hour treatment. No other statistically significant changes were detected.
The results show that EPR had no effect on the morphology and proliferativity of OSCC cells. However, the significant decline in EGFR expression after EPR treatment suggests that EPR might play an important role in the regulation of EGFR expression and hence OSCC progression.
表皮调节素（EPR）是表皮生长因子（EGF）家族的一个新成员。研究表明，它能促进口腔上皮的伤口愈合，增强其他上皮组织的增殖，并参与多种上皮相关的恶性肿瘤，如结直肠癌、肺癌和膀胱癌。最近，在一项对存档口腔鳞状细胞癌（OSCC）标本的研究中发现EPR转录本水平较高。这意味着EPR可能与OSCC的进展有关。本研究的目的是阐明EPR对H系列OSCC细胞系的（i）细胞形态变化、（ii）细胞增殖和（iii）受体表达的影响。
首先对H系列细胞系的临床病理来源以及表皮生长因子受体（EGFR）和ErbB4受体的表达进行了表征。基于这些参数，选择了两个H系列细胞系，即H103和H357用于后续实验。在所有后续实验中，用1 ng/ml、10 ng/ml和20 ng/ml的EPR处理细胞系24小时和48小时。未处理的细胞作为对照，用于与每个处理组进行比较。分别使用相差显微镜、5-溴-2'-脱氧尿苷（BrdU）检测和流式细胞术评估OSCC细胞系的细胞形态变化、细胞增殖和受体表达。使用学生t检验对结果进行比较和分析。
无论测试的EPR剂量如何，也无论在不同的时间点之间，细胞均未出现明显的形态变化。EPR处理后细胞增殖没有显著变化。至于EPR对受体表达的影响，24小时处理后，20 ng/ml的EPR显著降低了H103细胞系中EGFR表达的密度（p值 = 0.049）。未检测到其他具有统计学意义的变化。
结果表明，EPR对OSCC细胞的形态和增殖能力没有影响。然而，EPR处理后EGFR表达的显著下降表明，EPR可能在EGFR表达的调节以及OSCC进展中发挥重要作用。
