Department of Biotechnology, Karunya Institute of Technology and Sciences, Karunya Nagar, Coimbatore 641 114, Tamil Nadu, India.
Department of Biotechnology, Karunya Institute of Technology and Sciences, Karunya Nagar, Coimbatore 641 114, Tamil Nadu, India.
Gene. 2018 Aug 20;668:18-26. doi: 10.1016/j.gene.2018.05.051. Epub 2018 May 17.
Molecular targeted therapy for specific genes is an emerging research. Retinoic Acid Receptor (RAR-β) is a key tumor suppressor which is found to be lost drastically during much cancer progression. We hence, analyzed the expression level of RAR-β gene during B(a)P induced lung cancer development in mice and studied the lung cancer targeted action of All Trans Retinoic Acid (ATRA) in DOTAP liposomal formulation. The effect of its treatment on lung cancer was determined by histopathological analysis. RAR-β gene expression was assessed by RT-PCR and qPCR. A distinct band for RAR-β gene (density - 0.5123 for lung and 0.5160 for liver) was observed in normal mice, whereas no visible band was observed in cancer induced group, indicating loss of RAR-β gene expression. Both ATRA and lipo-ATRA treated groups showed detectable RAR-β expression with relatively lesser density than the normal group. The expression was more intense in lipo-ATRA treatment (density-0.2973) compared with free ATRA treatment (density-0.1549) in lung tissues. The qPCR results also have highlighted a highly significant (p ≤ 0.01) variation RQ values between lipo-ATRA group (15.46 ± 1.54) and free ATRA group (7.58 ± 1.30) in lung tissue sample on 30th day. The mean RQ value for normal lung on 30th day was 20.86 ± 2.58 against the cancer control. The 120th day mice also showed the similar RAR-β expression pattern with further declined expression levels as there was no treatment given after 30 days. Interestingly, the lipo-ATRA treatment could show a highly significant (p ≤ 0.001) expression (12.00 ± 2.31) when compared with free ATRA treatment (3.31 ± 0.58) which implies that the lipo-ATRA formulation could result in sustained delivery of ATRA in target site. Histopathology of lung and liver on 120th day also revealed an effective therapeutic indication in lipo-ATRA treatment compared to free ATRA treatment due to lipo-ATRA's stealth property and it efficiently inhibited the metastasis to liver. These results revealed that the lipo-ATRA treatment has efficiently delivered ATRA into target site than free ATRA and in-turn it might have induced the expression of RAR-β gene or prevented loss of RAR-β gene in cancer animals.
针对特定基因的分子靶向治疗是一项新兴的研究。视黄酸受体（RAR-β）是一种关键的肿瘤抑制因子，在许多癌症进展过程中发现其急剧丢失。因此，我们分析了 B(a)P 诱导的小鼠肺癌发生过程中 RAR-β 基因的表达水平，并研究了全反式视黄酸（ATRA）在 DOTAP 脂质体制剂中的肺癌靶向作用。通过组织病理学分析来确定其对肺癌的治疗效果。通过 RT-PCR 和 qPCR 评估 RAR-β 基因的表达。在正常小鼠中观察到 RAR-β 基因的明显条带（肺密度为 0.5123，肝密度为 0.5160），而在癌症诱导组中未观察到可见条带，表明 RAR-β 基因表达丢失。ATRA 和 lipo-ATRA 治疗组均显示出可检测到的 RAR-β 表达，其密度相对低于正常组。在肺组织中，lipo-ATRA 治疗组（密度-0.2973）的表达强度明显高于游离 ATRA 治疗组（密度-0.1549）。qPCR 结果还突出显示，在第 30 天的肺组织样本中，lipo-ATRA 组（15.46±1.54）和游离 ATRA 组（7.58±1.30）的 RQ 值存在高度显著（p≤0.01）差异。第 30 天正常肺的平均 RQ 值为 20.86±2.58，与癌症对照组相比。在第 120 天，120 天时，120 天时也表现出类似的 RAR-β 表达模式，由于在 30 天后没有给予治疗，因此表达水平进一步下降。有趣的是，与游离 ATRA 治疗组（3.31±0.58）相比，lipo-ATRA 治疗组（12.00±2.31）的表达具有高度显著（p≤0.001），这意味着 lipo-ATRA 制剂可以在靶部位持续递送 ATRA。第 120 天的肺和肝组织病理学也揭示了 lipo-ATRA 治疗与游离 ATRA 治疗相比具有有效的治疗效果，这是由于 lipo-ATRA 的隐身特性，它有效地抑制了向肝脏的转移。这些结果表明，与游离 ATRA 相比，lipo-ATRA 治疗能够更有效地将 ATRA 递送至靶部位，并且能够诱导 RAR-β 基因的表达或防止癌症动物中 RAR-β 基因的丢失。
