Yanli Ren

Down‐regulation of 5S rRNA by miR‐150 and miR‐383 enhances c‐Myc–rpL11 interaction and inhibits proliferation of esophageal squamous carcinoma cells

5S rRNA plays an important part in ribosome biology and is over‐expression in multiple cancers. In this study, we found that 5S rRNA is a direct target of miR‐150 and miR‐383 in esophageal squamous cell carcinoma (ESCC). Overexpression of miR‐150 and miR‐383 inhibited ESCC cell proliferation in vitro and in vivo. Moreover, 5S rRNA silencing by miR‐150 and miR‐383 might intensify rpL11–c‐Myc interaction, which attenuated role of c‐Myc as an oncogenic transcriptional factor and dysregulation of multiple c‐Myc target genes. Taken together, our results highlight the involvement of miRNAs in ribosomal regulation during tumorigenesis.

Well-defined reducible cationic nanogels based on functionalized low-molecular-weight PGMA for effective pDNA and siRNA delivery

UNLABELLED Nucleic acid-based gene therapy is a promising treatment option to cure numerous intractable diseases. For non-viral gene carriers, low-molecular-weight polymeric vectors generally demonstrate poor transfection performance, but benefit their final removals from the body. Recently, it was reported that aminated poly(glycidyl methacrylate) (PGMA) is one potential gene vector. Based on ethylenediamine (ED)-functionalized low-molecular-weight PGMA (denoted by PGED), a flexible strategy was herein proposed to design new well-defined reducible cationic nanogels (denoted by PGED-NGs) with friendly crosslinking reagents for highly efficient nucleic acid delivery. α-Lipoic acid (LA), one natural antioxidant in human body, was readily introduced into ED-functionalized PGMA and crosslinked to produce cationic PGED-NGs with plentiful reducible lipoyl groups. PGED-NGs could effectively complex plasmid DNA (pDNA) and short interfering RNA (siRNA). Compared with pristine PGED, PGED-NGs exhibited much better performance of pDNA transfection. PGED-NGs also could efficiently transport MALAT1 siRNA (siR-M) into hepatoma cells and significantly suppressed the cancer cell proliferation and migration. The present work indicated that reducible cationic nanogels involving LA crosslinking reagents are one kind of competitive candidates for high-performance nucleic acid delivery systems. STATEMENT OF SIGNIFICANCE Recently, the design of new types of high-performance nanoparticles is of great significance in delivering therapeutics. Nucleic acid-based therapy is a promising treatment option to cure numerous intractable diseases. A facile and straightforward strategy to fabricate safe nucleic acid delivery nanovectors is highly desirable. In this work, based on ethylenediamine-functionalized low-molecular-weight poly(glycidyl methacrylate), a flexible strategy was proposed to design new well-defined reducible cationic nanogels (denoted by PGED-NGs) with α-Lipoic acid, one friendly crosslinking reagent, for highly efficient nucleic acid delivery. Such PGED-NGs possess plentiful reducible lipoyl groups, effectively encapsulated pDNA and siRNA and exhibited excellent abilities of nucleic acid delivery. The present work indicated that reducible cationic nanogels involving α-lipoic acid crosslinking reagents are one kind of competitive candidates for high-performance nucleic acid delivery systems.

miR-190a inhibits epithelial–mesenchymal transition of hepatoma cells via targeting the long non-coding RNA treRNA

treRNA is a long non‐coding RNA (lncRNA) involved in cancer progression. In this study, we show that miR‐190a can silence treRNA post‐transcriptionally. Suppression of treRNA by miR‐190a led to significant changes of mesenchymal–epithelial transition markers and impaired migration and invasion capability of hepatoma cells. TCGA data indicated that miR‐190a exhibited lower expression in hepatoma tissues, especially from patients with vascular tumor invasion, compared to normal tissues. Our results reveal the involvement of miR‐190a–treRNA axis in hepatoma progression and shed light on lncRNA‐based cancer therapies for hepatoma patients at high risk of metastasis.

The identification of two regulatory ESCC susceptibility genetic variants in the TERT-CLPTM1L loci

The chromosome 5p15.33 TERT-CLPTM1L region has been identified by genome-wide association studies as a susceptibility locus of multiple malignancies. However, the involvement of this locus in esophageal squamous cell carcinoma (ESCC) development is still largely unclear. We fine-mapped the TERT-CLPTM1L region through genotyping 15 haplotype-tagging single nucleotide polymorphisms (htSNPs) using a two stage case-control strategy. After analyzing 2098 ESCC patients and frequency-matched 2150 unaffected controls, we found that rs2853691, rs2736100 and rs451360 genetic polymorphisms are significantly associated with ESCC risk in Chinese (all P<0.05). Reporter gene assays indicated that the ESCC susceptibility SNP rs2736100 locating in a potential TERT intronic promoter has a genotype-specific effect on TERT expression. Similarly, the CLPTM1L rs451360 SNP also showed allelic impacts on gene expression. After measuring TERT and CLPTM1L expression in sixty-six pairs of esophageal cancer and normal tissues, we observed that the rs2736100 G risk allele carriers showed elevated oncogene TERT expression. Also, subjects with the rs451360 protective T allele had much lower oncogene CLPTM1L expression than those with G allele in tissue specimens. Results of these analyses underline the complexity of genetic regulation of telomere biology and further support the important role of telomerase in carcinogenesis. Our data also support the involvement of CLPTM1L in ESCC susceptibility.

The long noncoding RNAPCAT-1links the microRNA miR-215 to oncogene CRKL-mediated signaling in hepatocellular carcinoma

The long non-coding RNA (lncRNA) PCAT-1 resides in the chromosome 8q24 cancer-risk locus and acts as a vital oncogene during tumorigenesis and progression. However, how PCAT-1 is post-transcriptionally regulated, for example, by small ncRNAs, such as microRNAs (miRNAs) is largely unknown. Here, we report how miRNAs regulate PCAT-1 expression and also investigate the biological significance of this regulation in hepatocellular carcinoma (HCC). We found that miR-215, a P53-inducible miRNA, is a key regulator of PCAT-1 expression in HCC and identified an interaction between miR-215 and PCAT-1 in dual luciferase reporter gene assays. We also found that post-transcriptional silencing of PCAT-1 by miR-215 or PCAT-1 siRNAs significantly inhibited proliferation of HCC cells and, conversely, that inhibition of endogenous miR-215 up-regulated PCAT-1 expression and promoted cell viability. The tumor-suppressing role of miR-215 was further confirmed in an in vivo mouse HCC xenograft model. Of note, gene profiling assays suggested that the kinase CRK-like proto-oncogene, adaptor protein (CRKL), is a potential downstream target of the miR–215–PCAT-1 axis in HCC, and we demonstrated that CRKL silencing significantly suppresses cell proliferation. Taken together and considering the essential role of CRKL in cancer cells, we propose that the TP53–miR-215–PCAT-1–CRKL axis might represent an important regulatory pathway in HCC. In summary, our results highlight the involvement of several ncRNAs in HCC and thus provide critical insights into the molecular pathways operating in this malignancy.

EPB41, a novel hepatoma susceptibility gene dysregulated by c-Myc: an integrative functional genomics study

BACKGROUND Genome-wide association studies (GWAS) have provided insight into cancer genetics. However, molecular mechanisms whereby many susceptibility single nucleotide polymorphisms (SNPs) identified by GWAS promote cancer heritability and risk are unknown. New research strategies to evaluate functionality are needed to systematically study causal genetic variants. METHODS In this study, we developed an integrative functional genomics method to identify cancer susceptibility SNPs in transcription factor binding sites across the whole genome. By integration of functional genomic data from c-Myc cistromics, 1000 Genomes and the TRANSFAC matrix databases, we identified SNPs in the c-Myc cistrome that might modulate c-Myc binding affinity in hepatocellular carcinoma. We took blood samples from patients with hepatitis B-related hepatocellular carcinoma who were admitted to Shandong Cancer Hospital, Jinan, Shandong Province. China, or Huaian No. 2 Hospital, Huaian, Jiangsu Province, China. We extracted genomic DNA from these samples and did genotype analyses. Written informed consent was obtained from all participants and the study was ethically approved by the institutional review boards. FINDINGS We identified 12 SNPs in 1806 people with hepatitis B-related hepatocellular carcinoma, we genotyped these SNPs and 1708 controls. We identified a novel hepatocellular carcinoma susceptibility SNP, EPB41 rs157224 G>T (OR of T allele 1·64 [95% CI 1·32-2·02]; p<0·00001), in Chinese patients with hepatocellular carcinoma. This SNP in EPB41 predisposes individuals to hepatocellular carcinoma through modification of c-Myc-mediated transcriptional regulation; the risk allele has decreased gene expression. EPB41 is a novel hepatocellular carcinoma susceptibility gene. Consistent with this notion, a EPB41 expression is decreased tissue samples from patients with hepatocellular carcinoma, especially portal vein metastasis or intrahepatic metastasis. INTERPRETATION Our results show that SNP EPB41 rs157224 G>T could be associated with increased susceptibility to hepatocellular carcinoma and show that insight into malignancy pathology can be made using a genome-wide approach. FUNDING National Natural Science Foundation of China (81201586 and 31271382), National High-Tech Research and Development Program of China (2015AA020950), State Key Laboratory of Molecular Oncology (SKL-KF-2015-05).