Murine hepatocellular carcinoma derived stem cells reveal epithelial-to-mesenchymal plasticity

AIM To establish a model to enrich and characterize stemlike cells from murine normal liver and hepatocellular carcinoma(HCC) cell lines and to further investigate stem-like cell association with epithelial-to-mesenchymal transition(EMT).METHODS In this study,we utilized a stem cell conditioned serumfree medium to enrich stem-like cells from mouse HCC and normal liver cell lines,Hepa 1-6 and AML12,respectively.We isolated the 3-dimensional spheres and assessed their stemness characteristics by evaluating theRNA levels of stemness genes and a cell surface stem cell marker by quantitative reverse transcriptase-PCR(q RTPCR).Next,we examined the relationship between stem cells and EMT using q RT-PCR.RESULTS Three-dimensional spheres were enriched by culturing murine HCC and normal hepatocyte cell lines in stem cell conditioned serum-free medium supplemented with epidermal growth factor,basic fibroblast growth factor and heparin sulfate.The 3-dimensional spheres had enhanced stemness markers such as Klf4 and Bmi1 and hepatic cancer stem cell(CSC) marker Cd44 compared to parental cells grown as adherent cultures.We report that epithelial markers E-cadherin and ZO-1 were downregulated,while mesenchymal markers Vimentin and Fibronectin were upregulated in 3-dimensional spheres.The 3-dimensional spheres also exhibited changes in expression of Snai,Zeb and Twist family of EMT transcription factors.CONCLUSION Our novel method successfully enriched stem-like cells which possessed an EMT phenotype.The isolation and characterization of murine hepatic CSCs could establish a precise target for the development of more effective therapies for HCC.

Single-cell transcriptomic analysis of adult mouse pituitary reveals sexual dimorphism and physiologic demand-induced cellular plasticity

The anterior pituitary gland drives highly conserved physiologic processes in mammalian species.These hormonally controlled processes are central to somatic growth,pubertal transformation,fertility,lactation,and metabolism.Current cellular models of mammalian anteiror pituitary,largely built on candidate gene based immuno-histochemical and mRNA analyses,suggest that each of the seven hormones synthesized by the pituitary is produced by a specific and exclusive cell lineage.However,emerging evidence suggests more complex relationship between hormone specificity and cell plasticity.Here we have applied massively parallel single-cell RNA sequencing (scRNA-seq),in conjunction with complementary imaging-based single-cell analyses of mRNAs and proteins,to systematically map both cell-type diversity and functional state heterogeneity in adult male and female mouse pituitaries at single-cell resolution and in the context of major physiologic demands.These quantitative single-cell analyses reveal sex-specific cell-type composition under normal pituitary homeostasis,identify an array of cells associated with complex complements of hormone-enrlchment,and undercover non-hormone producing interstitial and supporting cell-types.Interestingly,we also identified a Pou1f1-expressing cell population that is characterized by a unique multi-hormone gene expression profile.In response to two well-defined physiologic stresses,dynamic shifts in cellular diversity and trenscrlptome profiles were observed for major hormone producing and the putative multi-hormone cells.These studies reveal unanticipated cellular complexity and plasticity in adult pituitary,and provide a rich resource for further validating and expanding our molecular understanding of pituitary gene expression programs and hormone production.

Metastatic tumor cells- genotypes and phenotypes

BACKGROUND： Metastasis is the primary cause of mortality in cancer patients. Therefore, elucidating the genetics and epigenetics of metastatic tumor cells and the mechanisms by which tumor cells acquire metastatic properties constitute significant challenges in cancer research. OBJECTIVE： To summarize the current understandings of the specific genotype and phenotype of the metastatic tumor cells. METHOD and RESULT： In-depth genetic analysis of tumor cells, especially with advances in the next-generation sequencing, have revealed insights of the genotypes of metastatic tumor cells. Also, studies have shown that the cancer stem cell （CSC） and epithelial to mesenchymal transition （EMT） phenotypes are associated with the metastatic cascade. CONCLUSION： In this review, we will discuss recent advances in the field by focusing on the genomic instability and phenotypic dynamics of metastatic tumor cells.

A shifting adversary:control of pancreatic cancer transcriptomic subtypes

Cellular plasticity,the dynamic ability of cells to adopt distinct transcriptional states,plays a well-known role in the pancreas during the initiation of pancreatic ductal adenocarcinoma(PDA),the most common form of pancreatic cancer.It is now becoming clear that plasticity also plays an important role after the emergence of PDA.PDA is composed of two major transcriptional subtypes,classical and basal-like,with important biological differences.Recent work has indicated that individual tumors can be comprised of cells of each subtype,and that tumor subtype can change during the evolution of a tumor.This suggests that PDA cells can transit between transcriptional states,with important implications for disease progression.This review discusses what is currently known about inter-subtype plasticity and how this process is controlled.