Breast cancer, as the most common cancer in women worldwide, represents about 30% of all cancers affecting women. Long non-coding RNAs (lncRNAs) have been implicated in the regulation of several biological processes, and their dysregulation in cancer has well been documented. To investigate possible age-dependent variations in expression profiles of lncRNAs, we evaluated the expression levels of four lncRNAs, i.e., MALAT1, GAS5, SRA, and NEAT1, in breast cancer (BC) samples obtained from younger (<45 years) and older (>45 years) women. Tumor samples (n = 23) and 15 normal tissues were collected from BC patients. All tumor and normal samples were morphologically confirmed by a pathologist. RNA was extracted from the tissues and cDNAs were then synthesized. The lncRNA expression levels were evaluated by qRT-PCR. The changes in the expression levels were determined using the ΔΔCt method. Compared to normal tissues, BC tissues from both age groups (women under 45 years of age and women above 45 years of age) showed upregulation of MALAT1 (p = 0.003 and p = 0.0002), SRA (p = 0.005 and p = 0.0002), and NEAT1 (p = 0.010 and p = 0.0002) and downregulation of GAS5 (p = 0.0002 and p = 0.0005). Additionally, our analysis showed significant and direct correlation between the age and the expression levels of three of the four lncRNAs studied in this work. All four lncRNAs were overexpressed in both MDA-MB-231 and MCF7 cell lines (p = 0.1000). Our data show that MALAT1, GAS5, SRA, and NEAT1 lncRNAs are dysregulated in BC samples. However, except for MALAT1, the expression levels of all of these lncRNAs were significantly lower in cancers developed in younger cases, where poorer prognosis is suggested. Of note, GAS5 reduced expression has been documented to correlate with tumor progression.

乳腺癌是全世界女性中最常见的癌症，约占影响女性的所有癌症的30％。长期的非编码RNA（lncRNA）已牵涉到几种生物学过程的调控中，并且它们在癌症中的失调也有充分的文献记载。为了调查lncRNAs表达谱中可能的年龄依赖性变异，我们评估了四种lncRNAs的表达水平，即MALAT1，GAS5，SRA和NEAT1，从年轻（<45岁）和年长（> 45岁）妇女那里获得的乳腺癌（BC）样本中。从BC患者中收集了肿瘤样本（n = 23）和15个正常组织。所有肿瘤样品和正常样品均由病理学家进行形态学确认。从组织中提取RNA，然后合成cDNA。通过qRT-PCR评估lncRNA表达水平。使用ΔΔCt方法确定表达水平的变化。与正常组织相比，两个年龄段（45岁以下的女性和45岁以上的女性）的BC组织均显示MALAT1（p = 0.003和p = 0.0002），SRA（p = 0.005和p = 0.0002）上调。，以及NEAT1（p = 0.010和p = 0.0002）和GAS5的下调（p = 0.0002和p​​ = 0.0005）。此外，我们的分析显示，年龄与这项研究中所研究的四种lncRNA中的三种的表达水平之间存在显着且直接的相关性。所有四个lncRNA在MDA-MB-231和MCF7细胞系中均过表达（p = 0.1000）。我们的数据显示MALAT1，GAS5，SRA和NEAT1 lncRNA在BC样本中失调。但是，除了MALAT1以外，所有这些lncRNA的表达水平在较年轻的病例（预后较差）中发展的癌症中均显着降低。值得注意的是，GAS5减少的表达已被证明与肿瘤进展相关。