Oral squamous cell carcinoma (OSCC) is highly predominant in India due to excessive use of tobacco. Here we investigated Long INterpersed Element 1 (LINE or L1) retrotransposon activity in OSCC samples in the same population. There are almost 500,000 copies of L1 occupied around 30% of the human genome. Although most of them are inactive, around 150–200 copies are actively jumping in a human genome. L1 encodes two proteins designated as ORF1p and ORF2p and expression of both proteins are critical for the process of retrotransposition. Here we have analyzed L1 ORF1p expression in a small cohort (n = 15) of paired cancer-normal tissues obtained from operated oral cancer patients. Immunohistochemistry (IHC) with the human ORF1 antibody showed the presence of ORF1p in almost 60% cancer samples, and few of them also showed aberrant p53 expression. Investigating L1 promoter methylation status, showed certain trends towards hypomethylation of the L1 promoter in cancer tissues compared to its normal counterpart. Our data raise the possibility that L1ORF1p expression might have some role in the onset and progression of this particular type of cancer.

由于过度使用烟草，口腔鳞状细胞癌（OSCC）在印度极为盛行。在这里，我们调查了同一人群中OSCC样本中的长插入元素1（LINE或L1）反转录转座子活性。大约30万个L1拷贝占据了人类基因组的30％。尽管它们大多数不活跃，但在人类基因组中大约有150-200个拷贝活跃地跳跃。L1编码两个称为ORF1p和ORF2p的蛋白质，两种蛋白质的表达对于逆转座过程至关重要。在这里，我们分析了一个小队列（n = 15）从经手术的口腔癌患者获得的成对的癌症正常组织。含有人类ORF1抗体的免疫组织化学（IHC）显示，在几乎60％的癌症样本中都存在ORF1p，而且很少有人也显示出异常的p53表达。调查其L1启动子的甲基化状态，显示了与癌旁组织的L1启动子低甲基化有关的某些趋势。我们的数据提出了L1ORF1p表达可能在这种特定类型的癌症的发生和发展中发挥一定作用的可能性。