LTA4H extensively associates with mRNAs and lncRNAs indicative of its novel regulatory targets

To explore the potential roles of LTA4H in LSCC, we applied improved RNA immunoprecipitation and sequencing(iRIP-Seq) experiments to obtain LTA4H-bound RNA profile in modal HeLa cells and verified LTA4H-regulated genes using QRT-PCR. The RNA-binding metabolic enzyme LTA4H is a new target for cancer chemoprevention and treatment. The elevated expression of LTA4H in laryngeal squamous cell carcinoma has been demonstrated in recent research to promote tumor proliferation, migration and metastasis without clear mechanism. To explore the potential roles of LTA4H in LSCC, we applied improved RNA immunoprecipitation and sequencing(iRIP-Seq) experiments to obtain LTA4H-bound RNA profile in modal HeLa cells and verified LTA4H-regulated genes using QRT-PCR. We found that LTA4H extensively binds to mRNAs/pre-mRNAs and lncRNAs. In the LTA4H binding peak, the frequency of AAGG motifs reported for TRA2β4 is high in both replicates. Notably, LTA4H-binding genes were significantly enriched in mitotic cell cycle, DNA repair, RNA splicing related pathways and RNA metabolism pathways, implicating a tumor-associated alternative splicing regulation mechanism. QRT-PCR validation confirmed LTA4H specifically binds to mRNAs of carcinogenesis-associated genes, including LTBP3, ROR2, EGFR, HSP90B1, and lncRNAs represented by NEAT1. These findings suggesting that LTA4H may combine with genes associated with Laryngeal squamous cell carcinoma (LSCC) as an RNA-binding protein to perform a cancer regulatory function. Our study further expanding the understanding of molecular mechanism of LTA4H as a possible LSCC clinical therapy target.

为探究白细胞三烯A4水解酶（LTA4H）在喉鳞状细胞癌（LSCC, Laryngeal squamous cell carcinoma）中的潜在作用，我们采用改进型RNA免疫沉淀测序（iRIP-Seq, improved RNA immunoprecipitation and sequencing）技术，在HeLa模型细胞中获取LTA4H结合的RNA谱，并通过实时定量聚合酶链反应（QRT-PCR, quantitative real-time polymerase chain reaction）验证受LTA4H调控的基因。作为一种兼具RNA结合能力的代谢酶，LTA4H是癌症化学预防与治疗的全新靶点。已有研究证实，喉鳞状细胞癌组织中LTA4H表达上调可促进肿瘤增殖、迁移与侵袭转移，但具体分子机制尚未明确。为探究白细胞三烯A4水解酶（LTA4H）在喉鳞状细胞癌（LSCC, Laryngeal squamous cell carcinoma）中的潜在作用，我们采用改进型RNA免疫沉淀测序（iRIP-Seq, improved RNA immunoprecipitation and sequencing）技术，在HeLa模型细胞中获取LTA4H结合的RNA谱，并通过实时定量聚合酶链反应（QRT-PCR, quantitative real-time polymerase chain reaction）验证受LTA4H调控的基因。本研究发现，LTA4H可广泛结合信使RNA（mRNA）/前体信使RNA（pre-mRNA）以及长链非编码RNA（lncRNAs）。在LTA4H结合峰中，此前报道于TRA2β4的AAGG基序在两组生物学重复中均呈现高出现频率。值得注意的是，受LTA4H结合的基因显著富集于有丝分裂细胞周期、DNA修复、RNA剪接相关通路及RNA代谢通路，提示其可能通过调控肿瘤相关可变剪接发挥功能。实时定量聚合酶链反应验证结果证实，LTA4H可特异性结合致癌相关基因的mRNA，包括LTBP3、ROR2、EGFR、HSP90B1，以及以NEAT1为代表的长链非编码RNA。上述研究结果表明，LTA4H可作为RNA结合蛋白，与喉鳞状细胞癌相关基因结合，进而发挥癌症调控功能。本研究进一步加深了对LTA4H分子机制的认知，为其作为喉鳞状细胞癌潜在临床治疗靶点提供了理论依据。