Abstract The sialoglycoprotein podocalyxin is absent in normal pancreas but is overexpressed in pancreatic cancer and is associated with poor clinical outcome. Here, we investigate the role of podocalyxin in migration and metastasis of pancreatic adenocarcinomas using SW1990 and Pa03c as cell models. Although ezrin is regarded as a cytoplasmic binding partner of podocalyxin that regulates actin polymerization via Rac1 or RhoA, we did not detect podocalyxin–ezrin association in pancreatic cancer cells. Moreover, depletion of podocalyxin did not alter actin dynamics or modulate Rac1 and RhoA activities in pancreatic cancer cells. Using mass spectrometry, bioinformatics analysis, coimmunoprecipitation, and pull-down assays, we discovered a novel, direct binding interaction between the cytoplasmic tail of podocalyxin and the large GTPase dynamin-2 at its GTPase, middle, and pleckstrin homology domains. This podocalyxin–dynamin-2 interaction regulated microtubule growth rate, which in turn modulated focal adhesion dynamics and ultimately promoted efficient pancreatic cancer cell migration via microtubule- and Src-dependent pathways. Depletion of podocalyxin in a hemispleen mouse model of pancreatic cancer diminished liver metastasis without altering primary tumor size. Collectively, these findings reveal a novel mechanism by which podocalyxin facilitates pancreatic cancer cell migration and metastasis. Significance: These findings reveal that a novel interaction between podocalyxin and dynamin-2 promotes migration and metastasis of pancreatic cancer cells by regulating microtubule and focal adhesion dynamics.
<p>Supplementary Figure 1. The rate of proliferation is the same in the orthotopic and transgenic KPC mouse models Supplementary Figure 2. Single c-Met or Hh inhibitor treatment leads to the enhanced expression of the other target and the combination of both c-Met and Hh inhibitors suppresses the expression of both targets more effectively Supplementary Figure 3. Prolonged treatment of single HGF/c-Met or Hh inhibitor leads to resistance to single targeted agents, which can be overcome by the combination of both c-Met and Hh inhibitors. Supplementary Figure 4. Lentiviral knockdown of c-Met in KPC tumor cells results in decrease of Shh expression. Supplementary Materials and Methods</p>
Abstract Recent advances in spatial transcriptomics (ST) enable gene expression measurements from a tissue sample while retaining its spatial context. This technology enables unprecedented in situ resolution of the regulatory pathways that underlie the heterogeneity in the tumor and its microenvironment (TME). The direct characterization of cellular co-localization with spatial technologies facilities quantification of the molecular changes resulting from direct cell-cell interaction, as occurs in tumor-immune interactions. We present SpaceMarkers, a novel bioinformatics algorithm to infer molecular changes from cell-cell interaction from latent space analysis of ST data. We apply this approach to infer molecular changes from tumor-immune interactions in Visium spatial transcriptomics data of metastasis, invasive and precursor lesions, and immunotherapy treatment. Further transfer learning in matched scRNA-seq data enabled further quantification of the specific cell types in which SpaceMarkers are enriched. Altogether, SpaceMarkers can identify the location and context-specific molecular interactions within the TME from ST data.
Interleukin-6 (IL-6), a pleiotropic cytokine, is involved in extensive immune regulation and hematopoietic regulation. We observed the effect of fibroblast mediated human IL-6 gene therapy on hematopoiesis. The platelet counts started to increase at day 4 after implantation of IL-6 highly secreting fibroblast cells and peaked at day 10 and lasted at high level for 22 days. The neutrophil counts were elevated after their implantation, but WBC did not show any remarkable increase. The CFU-GM and CFU-MK in bone marrow and spleen were also increased significantly. The results demonstrated that fibroblasts mediated human IL-6 gene therapy can significantly augment in vivo hematopoietic functions in bone marrow and spleen and elevate the number of nuetrophils and platelets. This study provides a new approach to treat thrombopenia and chemotherapy or radiotherapy-induced hematopoietic suppression.
To study the metabolism of perlolyrine in rats, which is an active ingredient from the traditional Chinese herb, Ligusticum Wallichii Franch.After administration of perlolyrine and deuterated perlolyrine, the rat urines were hydrolyzed with glucuronidase, basified with NaHCO3-Na2CO3, extracted with ethyl ether--iso-propyl alcohol. The organic phases (neutral and basic fractions) were concentrated for trimethylsilyl (TMS) derivatives. The aqueous phase were acidified with sulfuric acid, taken to dryness and extracted with methanol (water soluble acidic fractions) and concentrated for TMS derivatives. The TMS derivatives were determined by gas chromatograph mass spectrometry (GC-MS).Perlolyrine and one metabolite were found from the neutral and basic fractions, and two different metabolites were found from the water soluble acidic fractions.It was proposed that the major metabolic pathways of perlolyrine were that the hydroxylation of perlolyrine and the oxidation of its hydroxylmethyl group.