Department of ENT, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, 430030, People's Republic of China.
Department of General Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, 430030, People's Republic of China.
BMC Cancer. 2018 Apr 3;18(1):367. doi: 10.1186/s12885-018-4255-3.
Assembling evidences suggested that aberrant expression of tissue differentiation-inducing non-protein coding RNA (TINCR) intimately associated with variety of human cancer. However, the expression pattern and involvement of TINCR in breast cancer has not been fully investigated. Here we set out to analyze expression of TINCR in breast cancer and elucidate its mechanistic involvement in tumor incidence and progression.
The expression of TINCR was determined by q-PCR. SP1 binding sites were analyzed by ChIP-qPCR. The relative transcription activity was measured with luciferase reporter assay. Cell viability was measured with CCK-8 method. Clonogenic capacity was evaluated by soft agar assay. Cell apoptosis was analyzed by Annexin V/7-AAD staining. The migration and invasion were determined by trans-well assay and wound healing. The tumor growth in vivo was evaluated in xenograft mice model. Protein expression was quantified by immunoblotting.
TINCR was aberrantly up-regulated by SP1, which in turn stimulated cell proliferation, anchorage-independent growth and suppressed cell apoptosis in breast cancer. TINCR silencing significantly suppressed migration and invasion in vitro and xenograft tumor growth in vivo. Mechanistically, TINCR modulated KLF4 expression via competing with miR-7, which consequently contributed to its oncogenic potential. MiR-7 inhibition severely compromised TINCR silencing-elicited tumor repressive effects.
Our data uncovered a crucial role of TINCR-miR-7-KLF4 axis in human breast cancer.
有证据表明，组织分化诱导非蛋白编码 RNA（TINCR）的异常表达与多种人类癌症密切相关。然而，TINCR 在乳腺癌中的表达模式及其参与机制尚未得到充分研究。在这里，我们分析了 TINCR 在乳腺癌中的表达，并阐明了其在肿瘤发生和进展中的机制性参与。
通过 q-PCR 测定 TINCR 的表达。通过 ChIP-qPCR 分析 SP1 结合位点。通过荧光素酶报告基因测定测量相对转录活性。通过 CCK-8 法测量细胞活力。通过软琼脂测定评估集落形成能力。通过 Annexin V/7-AAD 染色分析细胞凋亡。通过 Transwell 测定和划痕愈合测定测定细胞迁移和侵袭。通过异种移植小鼠模型评估体内肿瘤生长。通过免疫印迹法定量蛋白质表达。
TINCR 被 SP1 异常上调，进而刺激乳腺癌细胞的增殖、锚定非依赖性生长和抑制细胞凋亡。TINCR 沉默显著抑制了体外迁移和侵袭以及体内异种移植肿瘤的生长。在机制上，TINCR 通过与 miR-7 竞争来调节 KLF4 的表达，从而促进其致癌潜能。抑制 miR-7 严重削弱了 TINCR 沉默引起的肿瘤抑制作用。
我们的数据揭示了 TINCR-miR-7-KLF4 轴在人类乳腺癌中的重要作用。
