乳腺特异长链非编码RNA LINC00993通过结合hnRNPA1调控CDKN2A抑制乳腺肿瘤发生的分子机制

Studies have shown that long non-coding RNAs are involved in the development of breast cancer. Verifying some long non-coding RNAs expression by screening our microarray previously, we found that breast specific LINC00993 was significantly down-regulated in triple-negative breast cancer which is high malignancy, LINC00993 overexpression in breast cancer cells could cause G0/G1 block of cells, inhibit cell growth, promote apoptosis; moreover, it could up-regulate the two different CDKN2A gene transcripts expression of p16-INK4A and p14-ARF which inhibit cell growth; and LINC00993 can bind hnRNPA1 which regulates the expression of CDKN2A. These suggest that LINC00993 may combine with hnRNPA1 to regulate CDKN2A and thus inhibit the occurrence of breast cancer. We will knock out hnRNPA1 and CDKN2A to verify their core roles in the process of tumor inhibiton by LINC00993, and identify the loci of LINC00993 and hnRNPA1 by RNA pull-down experiment combined with cleavage technique, then clarify the specific mechanism of LINC00993 in the process of breast cancer.

研究表明长链非编码RNA参与了恶性肿瘤的发生发展。前期我们通过芯片筛选并验证了部分长链非编码RNA在乳腺肿瘤组织中的表达，发现乳腺特异表达的LINC00993在恶性程度较高的三阴性乳腺癌中表达明显下调，在乳腺癌细胞中过表达LINC00993可以使细胞发生G0/G1阻滞，细胞生长受抑制，凋亡发生增加；同时发现CDKN2A基因的两个抑制细胞生长的转录产物p16-INK4A和p14-ARF表达明显上调，且LINC00993能够结合可调控CDKN2A表达的hnRNPA1。推测LINC00993可通过结合hnRNPA1来调控CDKN2A从而影响乳腺肿瘤的发生。我们拟敲除hnRNPA1和CDKN2A验证其在LINC00993抑癌过程中的核心作用，采用RNA pull-down结合删切等技术鉴定LINC00993和hnRNPA1的作用位点，阐明LINC00993在乳腺癌发生过程中的具体机制。

三阴性乳腺癌 (TNBC)指不表达雌激素受体 (ER)、孕激素受体 (PR) 或人表皮生长因子受体 (HER)-2 基因的乳腺癌。由于缺乏明确的治疗靶点，TNBC患者的中位复发和死亡时间较短。研究表明长链非编码RNA参与了恶性肿瘤的发生发展。前期我们通过芯片筛选并验证了部分长链非编码RNA在乳腺肿瘤组织中的表达，发现乳腺特异表达的LINC00993在恶性程度较高的三阴性乳腺癌中表达明显下调。通过使用“关联内疚”和 GSEA方法，预测 LINC00993参与细胞周期途径。在乳腺癌细胞中过表达LINC00993可以使细胞发生G0/G1阻滞， 细胞生长受抑制，凋亡发生增加；细胞周期调控分子p16INK4A，p14ARF，p53，p21的表达受影响。因此，LINC00993作为一种乳腺癌特异性表达基因，具有抑制肿瘤功能，可能能作为乳腺癌的潜在靶点。