Search bioRxivSearch

Biology subjects

Wang, H.-Y.

Publications and source records attributed to Wang, H.-Y..

4 recordsLinked to original sources

Circular RNAs regulate cancer stem cells by FMRP against CCAR1 complex in hepatocellular carcinoma

Circular RNA (circRNA) possesses great pre-clinical diagnostic and therapeutic potentials in multiple cancers. However, the underlying correlation between circRNAs and cancer stem cells (CSCs) has not been reported. The absence of circZKSCAN1 endowed several malignant properties including cancer stemness and tightly correlated with worse overall and recurrence-free survival rate in HCC cells in vitro and in vivo. Bioinformatics analysis and RNA immunoprecipitation-sequencing (RIP-seq) results revealed that circZKSCAN1 exerted its inhibitive role by competitively binding FMRP, therefore, block the binding between FMRP and {beta}-catenin-binding protein-cell cycle and apoptosis regulator 1 (CCAR1) mRNA, and subsequently restraining the transcriptional activity of Wnt signaling. In addition, RNA-splicing protein Quaking 5 was found downregulated in HCC tissues and responsible for the reduction of circZKSCAN1. Collectively, this study revealed the mechanisms underlying the regulatory role of circZKSCAN1 in HCC CSCs and identified the newly discovered Qki5- circZKSCAN1-FMRP-CCAR1-Wnt signaling axis as a potentially important therapeutic target for HCC treatment.\n\nStatement of significanceO_LICircZKSCAN1, a novel negative regulator for cancer stem cells, was firstly identified with reverse correlation with HCC prognosis.\nC_LIO_LICircZKSCAN1 directly targets FMRP, and competitive binding with {beta}-catenin-binding protein cell cycle and apoptosis regulator 1 (CCAR1) for its activity.\nC_LIO_LIThe decreased expression of Quaking 5 is responsible for the absence of circZKSCAN1 in HCC.\nC_LI

cancer biology

Stout camphor tree genome fills gaps in understanding of flowering plant genome and gene family evolution

We present reference-quality genome assembly and annotation for the stout camphor tree (SCT; Cinnamomum kanehirae [Laurales, Lauraceae]), the first sequenced member of the Magnoliidae comprising four orders (Laurales, Magnoliales, Canellales, and Piperales) and over 9,000 species. Phylogenomic analysis of 13 representative seed plant genomes indicates that magnoliid and eudicot lineages share more recent common ancestry relative to monocots. Two whole genome duplication events were inferred within the magnoliid lineage, one before divergence of Laurales and Magnoliales and the other within the Lauraceae. Small scale segmental duplications and tandem duplications also contributed to innovation in the evolutionary history of Cinnamomum. For example, expansion of terpenoid synthase subfamilies within the Laurales spawned the diversity of Cinnamomum monoterpenes and sesquiterpenes.

genomics

Genetic load and mutational meltdown in cancer cell populations

ABSRACTLarge and non-recombining genomes are prone to accumulating deleterious mutations faster than natural selection can purge (Mullers ratchet). A possible consequence would then be the extinction of small populations. Relative to most single-cell organisms, cancer cells, with large and non-recombining genomes, could be particularly susceptible to such \"mutational meltdown\". Curiously, deleterious mutations in cancer cells are rarely noticed despite the strong signals in cancer genome sequences. Here, by monitoring single-cell clones from HeLa cell lines, we characterize deleterious mutations that retard cell proliferation. The main mutational events are copy number variations (CNVs), which happen at an extraordinarily high rate of 0.29 events per cell division. The average fitness reduction, estimated to be 18% per mutation, is also very high. HeLa cell populations therefore have very substantial genetic load and, at this level, natural population would likely experience mutational meltdown. We suspect that HeLa cell populations may avoid extinction only after the population size becomes large. Because CNVs are common in most cell lines and cancer tissues, the observations hint at cancer cells vulnerability, which could be exploited by therapeutic strategies.

evolutionary biology

Forward-reverse mutation cycles between stages of cancer development

Earlier, prominent occurrences of interstitial loss-of-heterozygosities (LOHs) were found in different cancers as a type of single-nucleotide-variations (SNVs), at rates far exceeding those of the commonly investigated gain-of-heterozygosities (GOHs) type of SNVs. Herein, such co-occurrences of LOHs and GOHs were confirmed in 102 cases of four cancer types analyzed with three different next-generation sequencing platforms, comparing non-tumor, paratumor, and tumor tissues with white-blood-cell controls; and in 246 pan-cancer cases of whole-genome tumor-control pairs. Unexpectedly, large numbers of SNVs enriched with CG>TG GOHs and copy-number-variations (CNVs) proximal to these GOHs were detected in the non-tumor tissues, which were extensively reversed in paratumors showing prominent TG>CG LOHs with proximal CNVs, and less so in tumors to form forward-reverse mutation cycles. Lineage effects in the reversions, likely resulting from directional selection, supported a sequential rather than parallel mode of evolution as described in a Stage Specific Populations model of cancer development.

cancer biology