Cell plasticity of 'stem-like' cancer-initiating cells (CICs) is a hallmark of cancer, allowing metastasis and cancer progression. Here, we studied whether simvastatin, a lipophilic statin, could impair the metastatic potential of CICs in high-grade serous ovarian cancer (HGS-ovC), the most lethal among the gynecologic malignancies. qPCR, immunoblotting and immunohistochemistry were used to assess simvastatin effects on proteins involved in stemness and epithelial-mesenchymal cell plasticity (EMT). Its effects on tumor growth and metastasis were evaluated using different models (e.g., spheroid formation and migration assays, matrigel invasion assays, 3D-mesomimetic models and cancer xenografts). We explored also the clinical benefit of statins by comparing survival outcomes among statin users vs non-users. Herein, we demonstrated that simvastatin modifies the stemness and EMT marker expression patterns (both in mRNA and protein levels) and severely impairs the spheroid assembly of CICs. Consequently, CICs become less metastatic in 3D-mesomimetic models and show fewer ascites/tumor burden in HGS-ovC xenografts. The principal mechanism behind statin-mediated effects involves the inactivation of the Hippo/YAP/RhoA pathway in a mevalonate synthesis-dependent manner. From a clinical perspective, statin users seem to experience better survival and quality of life when compared with non-users. Considering the high cost and the low response rates obtained with many of the current therapies, the use of orally or intraperitoneally administered simvastatin offers a cost/effective and safe alternative to treat and potentially prevent recurrent HGS-ovCs.

The PIM1 oncogene is over-expressed in human prostate cancer epithelial cells. Importantly, we observe that in human hyperplastic and cancerous prostate glands PIM1 is also markedly elevated in prostate fibroblasts, suggesting an important role for this kinase in epithelial/stromal crosstalk. The ability of PIM1 to regulate the biologic activity of stromal cells is demonstrated by the observation that expression of PIM1 kinase in human prostate fibroblasts increases the level and secretion of the extracellular matrix molecule, collagen 1A1 (COL1A1), the pro-inflammatory chemokine CCL5, and the platelet-derived growth factor receptors (PDGFR). PIM1 is found to regulate the transcription of CCL5. In co-cultivation assays where PIM1 overexpressing fibroblasts are grown with BPH1 prostate epithelial cells, PIM1 activity markedly enhances the ability of these fibroblasts to differentiate into myofibroblasts and express known markers of cancer-associated fibroblasts (CAFs). This differentiation can be reversed by the addition of small molecule PIM kinase inhibitors. Western blots demonstrate that PIM1 expression in prostate fibroblasts stimulates the phosphorylation of molecules that regulate 5’Cap driven protein translation, including 4EBP1 and eIF4B. Consistent with the hypothesis that the kinase controls translation of specific mRNAs in prostate fibroblasts, we demonstrate that PIM1 expression markedly increases the level of COL1A1 and PDGFRβ mRNA bound to polysomes. Together these results point on PIM1 as a novel factor in regulation of the phenotype and differentiation of fibroblasts in prostate cancer by controlling both the transcription and translation of specific mRNAs.

Clinical localization of primary tumors and sites of metastasis by PET is based on the enhanced cellular uptake of 2-deoxy-2-[18F]-fluoro-D-glucose (FDG). In prostate cancer, however, PET-FDG imaging has shown limited clinical applicability, suggesting that prostate cancer cells may utilize hexoses other than glucose, such as fructose, as the preferred energy source. Our previous studies suggested that prostate cancer cells overexpress fructose transporters, but not glucose transporters, compared with benign cells. Here, we focused on validating the functional expression of fructose transporters and determining whether fructose can modulate the biology of prostate cancer cells in vitro and in vivo. Fructose transporters, Glut5 and Glut9, were significantly upregulated in clinical specimens of prostate cancer when compared with their benign counterparts. Fructose levels in the serum of patients with prostate cancer were significantly higher than healthy subjects. Functional expression of fructose transporters was confirmed in prostate cancer cell lines. A detailed kinetic characterization indicated that Glut5 represents the main functional contributor in mediating fructose transport in prostate cancer cells. Fructose stimulated proliferation and invasion of prostate cancer cells in vitro. In addition, dietary fructose increased the growth of prostate cancer cell line–derived xenograft tumors and promoted prostate cancer cell proliferation in patient-derived xenografts. Gene set enrichment analysis confirmed that fructose stimulation enriched for proliferation-related pathways in prostate cancer cells. These results demonstrate that fructose promotes prostate cancer cell growth and aggressiveness in vitro and in vivo and may represent an alternative energy source for prostate cancer cells. Significance: This study identifies increased expression of fructose transporters in prostate cancer and demonstrates a role for fructose as a key metabolic substrate supporting prostate cancer cells, revealing potential therapeutic targets and biomarkers.

To study the association between the polymorphisms Arg462Gln and Asp541Glu from the RNASEL gene (1q25), and the polymorphisms rs620861, rs1447295, rs6983267, rs7837328 from the chromosome 8q24 with the risk of presenting prostate cancer (PCa) and its clinical characteristics in a Hispanic (Chilean) population. The study was performed on 21 control patients and 83 patients diagnosed with PCa. Polymorphisms were analysed from blood samples through real-time PCR by using TaqMan probes, and the genetic analysis was performed with the SNPStats program. Also, a comparison was performed between clinical characteristics of PCa and the presence of the different polymorphism genotypes by using the Minitab software. There was a significant association between the genotype G/G from the polymorphism rs6983267 with an overall increased risk of PCa, in patients both with or without family history of PCa (OR = 4.47, 95% CI = 1.05–18.94, P = 0.034 and OR = 3.57, 95% CI = 0.96–13.35, P = 0.037, respectively). Regarding clinical parameters, patients carrying the genotype C/C from the polymorphism Asp541Glu had significantly higher prostate-specific antigen (PSA) levels than patients carrying the other genotypes (P = 0.034). Moreover, patients with the genotype G/G of rs6983267 had higher PSA levels (P = 0.024). The polymorphism rs6983267 from region 3 of the chromosome 8q24 appears to be a prominent risk factor for PCa and a biomarker for cancer aggressiveness in the group of patients who presented higher levels of PSA at the time of diagnosis.

The polymorphism rs4430796 of the chromosome 17q12 appears to be a biomarker for cancer aggressiveness, increased PSA and tumor volume of PCa.

Background: Gallbladder cancer (GBC) is the most common tumor of the biliary tract. The incidence of GBC shows a large geographic variability, being particularly frequent in Native American populations. In Chile, GBC represents the second cause of cancer-related death among women. We describe here the establishment of three novel cell lines derived from the ascitic fluid of a Chilean GBC patient, who presented 46% European, 36% Mapuche, 12% Aymara and 6% African ancestry.Results: After immunocytochemical staining of the primary cell culture, we isolated and comprehensively characterized three independent clones (PUC-GBC1, PUC-GBC2 and PUC-GBC3) by short tandem repeat DNA profiling and RNA sequencing as well as karyotype, doubling time, chemosensitivity, in vitro migration capability and in vivo tumorigenicity assay. Primary culture cells showed high expression of CK7, CK19, CA 19-9, MUC1 and MUC16, and negative expression of mesothelial markers. The three isolated clones displayed an epithelial phenotype and an abnormal structure and number of chromosomes. RNA sequencing confirmed the increased expression of cytokeratin and mucin genes, and also of TP53 and ERBB2 with some differences among the three cells lines, and revealed a novel exonic mutation in NF1. The PUC-GBC3 clone was the most aggressive according to histopathological features and the tumorigenic capacity in NSG mice. Conclusions:The first cell lines established from a Chilean GBC patient represent a new model for studying GBC in patients of Native American descent.

Cancer therapy may be improved by the simultaneous interference of two or more oncogenic pathways contributing to tumor progression and aggressiveness, such as EGFR and p53. Tumor cells expressing gain-of-function (GOF) mutants of p53 (mutp53) are usually resistant to EGFR inhibitors and display invasive migration and AKT-mediated survival associated with enhanced EGFR recycling. D-Propranolol (D-Prop), the non-beta blocker enantiomer of propranolol, was previously shown to induce EGFR internalization through a PKA inhibitory pathway that blocks the recycling of the receptor. Here, we first show that D-Prop decreases the levels of EGFR at the surface of GOF mutp53 cells, relocating the receptor towards recycling endosomes, both in the absence of ligand and during stimulation with high concentrations of EGF or TGF-α. D-Prop also inactivates AKT signaling and reduces the invasive migration and viability of these mutp53 cells. Unexpectedly, mutp53 protein, which is stabilized by interaction with the chaperone HSP90 and mediates cell oncogenic addiction, becomes destabilized after D-Prop treatment. HSP90 phosphorylation by PKA and its interaction with mutp53 are decreased by D-Prop, releasing mutp53 towards proteasomal degradation. Furthermore, a single daily dose of D-Prop reproduces most of these effects in xenografts of aggressive gallbladder cancerous G-415 cells expressing GOF R282W mutp53, resulting in reduced tumor growth and extended mice survival. D-Prop then emerges as an old drug endowed with a novel therapeutic potential against EGFR- and mutp53-driven tumor traits that are common to a large variety of cancers.

Prostate cancer (PCa) is a multifocal neoplasm in which different cancer foci can be found within a single organ. This feature represents a technical difficulty when obtaining highly-enriched primary cultures of human prostate stroma cells (HPSCs), since their isolation involves enzymatic digestion of large pieces of tissue, resulting in an unknown proportion of benign- (BAF) and carcinoma-associated fibroblasts (CAF). Here we report an efficient tissue explant methodology to obtain highly-enriched populations of BAFs or CAFs from benign and malignant human prostate specimens, including needle biopsies. Also, we investigated whether different histological/pathological origins of the prostate tissue determine the activation of distinct transcription programs in HPSCs. Analysis of gene expression profiles revealed that CAFs exhibited a unique transcriptional program characterized by up-regulation of genes involved in proliferation, migration and cell adhesion. CAFs, but not BAFs, expressed typical activation markers such as α-smooth muscle actin, tenascin C and collagen 1 and stimulated tumor growth of PCa cells in vivo. Our study indicated that gene expression profile of HPSCs was determined mostly by the zone rather than the pathological state of the prostate tissue and that tissue explants from needle biopsies provide a valuable tool to obtain highly enriched primary cultures of HPSCs.