Kazerani Reihane, Salehipour Pouya, Shah Mohammadi Mohammadreza, Amanzadeh Jajin Elnaz, Modarressi Mohammad Hossein
Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Department of Medical Genetics, School of Medicine, Tehran University of Medical Science, Tehran, Iran.
Front Oncol. 2023 Feb 13;13:1075638. doi: 10.3389/fonc.2023.1075638. eCollection 2023.
Brain tumors (BTs) are perceived as one of the most common malignancies among children. The specific regulation of each gene can play a critical role in cancer progression. The present study aimed to determine the transcripts of the and genes, considering the alternative 5'UTR region, and investigating the expression of these different transcripts in BTs.
Public data on brain tumor microarray datasets in GEO were analyzed with R software to evaluate the expression levels of and genes (the Pheatmap package in R was also used to plot DEGs in a heat map). In addition, to validate our in-silico data analysis, RT-PCR was performed to determine the splicing variants of and genes in testis and brain tumor samples. The expression levels of splice variants of these genes were analyzed in 30 brain tumor samples and two testicular tissue samples as a positive control.
In silico results show that the differential expression levels of and were significant in the GEO datasets of BTs compared to normal samples (with adjusted p-value<0.05 and log fold change > 1). This study's experimental results showed that the gene produces four different transcripts with two distinct promoter regions and splicing exon 4. The relative mRNA expression of transcripts without exon 4 was higher than transcripts with exon 4 in BT samples (p-value<001). In , exon 2 in the 5'UTR region and exon 6 in the coding sequence were spliced. The expression analysis results showed that the relative mRNA expression of transcript variants without exon 2 was higher than other transcript variants with exon 2 in BT samples (p-value<001).
The decreased expression levels of transcripts with longer 5'UTR in BT samples than in testicular or low-grade brain tumor samples may decrease their translation efficiency. Therefore, decreased amounts of TSGA10 and GGNBP2 as potential tumor suppressor proteins, especially in high-grade brain tumors, may cause cancer development by angiogenesis and metastasis.
脑肿瘤（BTs）被认为是儿童中最常见的恶性肿瘤之一。每个基因的特定调控在癌症进展中可能起关键作用。本研究旨在确定考虑可变5'非翻译区（UTR）区域的[具体基因1]和[具体基因2]基因的转录本，并研究这些不同转录本在脑肿瘤中的表达。
使用R软件分析基因表达综合数据库（GEO）中脑肿瘤微阵列数据集的公开数据，以评估[具体基因1]和[具体基因2]基因的表达水平（R中的Pheatmap包也用于在热图中绘制差异表达基因）。此外，为了验证我们的计算机数据分析，进行逆转录聚合酶链反应（RT-PCR）以确定睾丸和脑肿瘤样本中[具体基因1]和[具体基因2]基因的剪接变体。在30个脑肿瘤样本和两个睾丸组织样本（作为阳性对照）中分析这些基因剪接变体的表达水平。
计算机分析结果表明，与正常样本相比，脑肿瘤的GEO数据集中[具体基因1]和[具体基因2]的差异表达水平显著（校正p值<0.05且对数倍变化>1）。本研究的实验结果表明，[具体基因1]基因产生四种不同的转录本，具有两个不同的启动子区域和剪接外显子4。在脑肿瘤样本中，没有外显子4的转录本的相对mRNA表达高于有外显子4的转录本（p值<0.01）。在[具体基因2]中，5'UTR区域的外显子2和编码序列中的外显子6被剪接。表达分析结果表明，在脑肿瘤样本中，没有外显子2的转录本变体的相对mRNA表达高于有外显子2的其他转录本变体（p值<0.01）。
与睾丸或低级别脑肿瘤样本相比，脑肿瘤样本中具有较长5'UTR的转录本表达水平降低可能会降低其翻译效率。因此，作为潜在肿瘤抑制蛋白的TSGA10和GGNBP2数量减少，尤其是在高级别脑肿瘤中，可能会通过血管生成和转移导致癌症发展。
