Highlights d Multiple SCLC molecular subtypes arise from a neuroendocrine cell of origin d MYC drives the NEUROD1 + and YAP1 + subtypes of SCLC in a temporal evolution d MYC directly activates NOTCH signaling to reprogram neuroendocrine fate d Multiple SCLC molecular subtypes are present within individual human tumors

Summary Gain-of-function Notch mutations are recurrent in mature small B-cell lymphomas such as mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL), but the Notch target genes that contribute to B-cell oncogenesis are largely unknown. We performed integrative analysis of Notch-regulated transcripts, genomic binding of Notch transcription complexes, and genome conformation data to identify direct Notch target genes in MCL cell lines. This unique B-cell Notch regulome is largely controlled through Notch-bound distal enhancers and includes genes involved in B-cell receptor and cytokine signaling and the oncogene MYC, which sustains proliferation of Notch-dependent MCL cell lines via a Notch-regulated lineage-restricted enhancer complex. Expression of direct Notch target genes is associated with Notch activity in an MCL xenograft model and in CLL lymph node biopsies. Our findings provide key insights into the role of Notch in MCL and other B-cell malignancies and have important implications for therapeutic targeting of Notch-dependent oncogenic pathways.

To identify hepatocellular carcinoma (HCC)‐implicated long noncoding RNAs (lncRNAs), we performed an integrative omics analysis by integrating mRNA and lncRNA expression profiles in HCC tissues. We identified a collection of candidate HCC‐implicated lncRNAs. Among them, we demonstrated that an lncRNA, which is named as p53‐stabilizing and activating RNA (PSTAR), inhibits HCC cell proliferation and tumorigenicity through inducing p53‐mediated cell cycle arrest. We further revealed that PSTAR can bind to heterogeneous nuclear ribonucleoprotein K (hnRNP K) and enhance its SUMOylation and thereby strengthen the interaction between hnRNP K and p53, which ultimately leads to the accumulation and transactivation of p53. PSTAR is down‐regulated in HCC tissues, and the low PSTAR expression predicts poor prognosis in patients with HCC, especially those with wild‐type p53. Conclusion: This study sheds light on the tumor suppressor role of lncRNA PSTAR, a modulator of the p53 pathway, in HCC.

BackgroundRenal cell carcinoma (RCC) is the most common type of kidney cancer. Studying the pathogenesis of RCC is particularly important, because it could provide a direct guide for clinical treatment. Given that tumor heterogeneity is probably reflected at the mRNA level, the study of mRNA in RCC may reveal some potential tumor-specific markers, especially single-cell RNA sequencing (scRNA-seq).MethodsWe performed an exploratory study on three pathological types of RCC with a small sample size. This study presented clear-cell RCC (ccRCC), type 2 pRCC, and chRCC in a total of 30,263 high-quality single-cell transcriptome information from three pathological types of RCC. In addition, scRNA-seq was performed on normal kidneys. Tumor characteristics were well identified by the comparison between different pathological types of RCC and normal kidneys at the scRNA level.ResultsSome new tumor-specific markers for different pathologic types of RCC, such as SPOCK1, PTGIS, REG1A, CP and SPAG4 were identified and validated. We also discovered that NDUFA4L2 both highly expressed in tumor cells of ccRCC and type 2 pRCC. The presence of two different types of endothelial cells in ccRCC and type 2 pRCC was also identified and verified. An endothelial cell in ccRCC may be associated with fibroblasts and significantly expressed fibroblast markers, such as POSTN and COL3A1. At last, by applying scRNA-seq results, the activation of drug target pathways and sensitivity to drug responses was predicted in different pathological types of RCC.ConclusionsTaken together, these findings considerably enriched the single-cell transcriptomic information for RCC, thereby providing new insights into the diagnosis and treatment of RCC.