中文摘要：

microRNA（miRNA）是一类长18-25个核苷酸的进化保守的内源性非编码单链RNA分子，它们基于与mRNA的序列互补，可以降解靶mRNA和抑制蛋白质翻译。大量研究显示，miRNA在细胞增殖、分化、发育和凋亡等方面起着重要的作用。其中miR-143和miR-145在多种肿瘤中表达降低，包括结直肠癌、乳腺癌、前列腺癌、膀胱癌、胃癌、肺癌、食管癌、宫颈癌、胰腺癌、鼻咽癌、卵巢癌、骨肉瘤、脂肪肉瘤、尤文氏肉瘤和白血病等，通过与多个靶基因KRAS、c—Myc和ERK5等作用抑制细胞增殖、侵袭和转移，促进细胞凋亡，增加抗肿瘤药物的敏感性，发挥类似于抑癌基因的作用。由此，抗肿瘤药物联合应用miR-143和／或miR-145有望成为新的肿瘤化疗方案。

英文摘要：

MicroRNAs （miRNAs） are a class of conservative endogenous non-coding RNAs with the length of 18-25 nucleotides, which can degrade mRNA and inhibit protein translation by binding to the target mRNA. Growing evidence has shown that miRNAs play crucial roles in cell proliferation, differentiation, development and apoptosis, miR-143 and miR-145 have been identified to be down-regulated in a variety of tumors, including colorectal cancer, breast cancer, prostate cancer, bladder cancer, gastric cancer, lung cancer, esophageal cancer, cervical cancer, pancreatic cancer, nasopharyngeal carcinoma, ovarian cancer, osteosarcoma, liposarcoma, Ewing＇s sarcoma, and leukemia, with the function of inhibiting cell proliferation, invasion and metastasis, promoting cell apoptosis, and increasing sensitivity to anti-tumor drugs by binding to the target genes, such as KRAS, c-Myc, and ERKS. Based on these backgrounds, the combined treatment of anti-tumor agents and miR-143 and/or miR-145 is a novel potential approach for chemotherapy.