BackgroundLiver cancer is one of the most deadly cancers in the world. There are various cells in liver tumor bulk, including liver tumor initiating cells (TICs), which account for liver tumorigenesis, drug resistance, relapse and metastasis. The homeobox (HOX) transcription factors play critical roles in many physiological and pathological processes, while, their roles in liver TICs and liver tumorigenesis remain unknown.MethodsAn unbiased screening was performed using online-available datasets. Liver TICs were sorted by FACS using surface markers CD133, CD13 and EPCAM, or enriched by oncosphere formation assay. TIC self-renewal was examined by oncosphere formation and tumor initiation assay. Loss of function and gain of function assays were performed to examine the role of lncRNA. RNA pulldown, RNA immunoprecipitation, ChIP, Western blot and double FISH were used to explore the molecular mechanism of lncRNA.ResultsHere, we examined the expression pattern of HOX transcription factors, and found HOXA10 was overexpressed in liver cancer samples. Moreover, a divergent lncRNA of HOXA10 (termed lncHOXA10 hereafter) was also highly expressed in liver cancer and liver TICs. LncHOXA10 drove liver TIC self-renewal and liver tumorigenesis through HOXA10-dependent manner. LncHOXA10 interacted with SNF2L and recruited NURF chromatin remodeling complex to HOXA10 promoter, and thus initiated the transcription of HOXA10. Through HOXA10 transcriptional regulation, lncHOXA10 activated HOXA10 in liver TICs. LncHOXA10-HOXA10 signaling can be targeted to eliminate liver TICs. Altogether, lncHOXA10 drove HOXA10 expression and thus promoted liver TIC self-renewal.ConclusionHOXA10 was the most highly expressed HOX transcription factor in liver cancer and liver TICs. LncHOXA10 drove the transcriptional activation of HOXA10. This work revealed the important role of HOX transcription factor in liver TIC self-renewal and added a new layer for liver TIC regulation.Electronic supplementary materialThe online version of this article (10.1186/s12943-018-0921-y) contains supplementary material, which is available to authorized users.

Background: This study aimed to evaluate the clinical significance of pre-treatment Naples prognostic score (NPS) in patients with osteosarcoma. Methods: The clinical data of 133 osteosarcoma patients between January 2011 and February 2018 in our hospital was retrospectively collected and analyzed. NPS was calculated from four parameters, including serum albumin level, serum total cholesterol (TC), lymphocyte-to-monocyte ratio (LMR), and neutrophil-to-lymphocyte ratio (NLR). Patients were divided into three groups (group 1-3) based on NPS. The relationships between NPS and clinical features, overall survival (OS), and progression-free survival (PFS) were analyzed. Two prediction models based on NPS and clinical parameters were developed: clinical parameters model (model A), and the combined model of NPS and clinical parameters (model B). Their predictive performances were further evaluated and compared. Results: The median follow-up time of this cohort was 46.0 (range, 5-75) months, while the median OS and PFS was 40 (range, 5-75) months and 36 (range, 5-71) months, respectively. NPS was significantly correlated with gender, tumor location, Enneking stage, pathological fracture, local recurrence, and metastasis (all P < 0.05). Variables of NPS, Enneking stage, local recurrence, metastasis, and NLR were confirmed as independent prognostic factors for OS and PFS by univariate and multivariate Cox analysis. Prediction model B obtained larger AUCs for OS and PFS and showed better consistency between nomogram-predicted and actual survival than that of model A at the follow-up time of 1-, 3-, and 5-year. Conclusions: NPS was a novel, reliable, and multidimensional prognostic scoring system with favorable predictive performance for patients with osteosarcoma.

Ubiquitin like protein 5 (UBL5) interacts with other proteins to regulate their function but differs from ubiquitin and other UBLs because it does not form covalent conjugates. Ubiquitin and most UBLs mediate the degradation of target proteins through the 26S proteasome but it is not known if UBL5 can also do that. Here we found that the UBL5s of rice and Nicotiana benthamiana interacted with rice stripe virus (RSV) p3 protein. Silencing of NbUBL5s in N. benthamiana facilitated RSV infection, while UBL5 overexpression conferred resistance to RSV in both N. benthamiana and rice. Further analysis showed that NbUBL5.1 impaired the function of p3 as a suppressor of silencing by degrading it through the 26S proteasome. NbUBL5.1 and OsUBL5 interacted with RPN10 and RPN13, the receptors of ubiquitin in the 26S proteasome. Furthermore, silencing of NbRPN10 or NbRPN13 compromised the degradation of p3 mediated by NbUBL5.1. Together, the results suggest that UBL5 mediates the degradation of RSV p3 protein through the 26S proteasome, a previously unreported plant defense strategy against RSV infection.

MicroRNAs have been reported to play an important role in diverse biological processes and progression of various cancers. MicroRNA-29a has been observed to be downregulated in human lung cancer tissues, but the function of microRNA-29a in lung cancer has not been well investigated. In this study, we demonstrated that the expression levels of microRNA-29a were significantly downregulated in 38 pairs of lung cancer tissues when compared to adjacent normal tissues. Overexpression of microRNA-29a inhibited the activity of cell proliferation and colony formation of lung cancer cells, H1299 and A549. Furthermore, microRNA-29a targeted NRAS proto-oncogene in lung cancer cells. In human clinical specimens, NRAS proto-oncogene was highly expressed in human lung cancer tissues compared to normal tissues. More interestingly, microRNA-29a also sensitizes lung cancer cells to cisplatin (CDDP[Please replace “CDDP” with its expansion in the abstract and also provide expansion for the same in its first occurrence in text, if appropriate.]) via its target, NRAS proto-oncogene. Thus, our results in this study demonstrated that microRNA-29a acted as a tumor suppressor microRNA, which indicated potential application of microRNAs for the treatment of human lung cancer in the future.